net/packet/af_packet.c

   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              PACKET - implements raw packet sockets.
   7  *
   8  * Authors:     Ross Biro
   9  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  10  *              Alan Cox, <gw4pts@gw4pts.ampr.org>
  11  *
  12  * Fixes:
  13  *              Alan Cox        :       verify_area() now used correctly
  14  *              Alan Cox        :       new skbuff lists, look ma no backlogs!
  15  *              Alan Cox        :       tidied skbuff lists.
  16  *              Alan Cox        :       Now uses generic datagram routines I
  17  *                                      added. Also fixed the peek/read crash
  18  *                                      from all old Linux datagram code.
  19  *              Alan Cox        :       Uses the improved datagram code.
  20  *              Alan Cox        :       Added NULL's for socket options.
  21  *              Alan Cox        :       Re-commented the code.
  22  *              Alan Cox        :       Use new kernel side addressing
  23  *              Rob Janssen     :       Correct MTU usage.
  24  *              Dave Platt      :       Counter leaks caused by incorrect
  25  *                                      interrupt locking and some slightly
  26  *                                      dubious gcc output. Can you read
  27  *                                      compiler: it said _VOLATILE_
  28  *      Richard Kooijman        :       Timestamp fixes.
  29  *              Alan Cox        :       New buffers. Use sk->mac.raw.
  30  *              Alan Cox        :       sendmsg/recvmsg support.
  31  *              Alan Cox        :       Protocol setting support
  32  *      Alexey Kuznetsov        :       Untied from IPv4 stack.
  33  *      Cyrus Durgin            :       Fixed kerneld for kmod.
  34  *      Michal Ostrowski        :       Module initialization cleanup.
  35  *         Ulises Alonso        :       Frame number limit removal and
  36  *                                      packet_set_ring memory leak.
  37  *              Eric Biederman  :       Allow for > 8 byte hardware addresses.
  38  *                                      The convention is that longer addresses
  39  *                                      will simply extend the hardware address
  40  *                                      byte arrays at the end of sockaddr_ll
  41  *                                      and packet_mreq.
  42  *              Johann Baudy    :       Added TX RING.
  43  *              Chetan Loke     :       Implemented TPACKET_V3 block abstraction
  44  *                                      layer.
  45  *                                      Copyright (C) 2011, <lokec@ccs.neu.edu>
  46  *
  47  *
  48  *              This program is free software; you can redistribute it and/or
  49  *              modify it under the terms of the GNU General Public License
  50  *              as published by the Free Software Foundation; either version
  51  *              2 of the License, or (at your option) any later version.
  52  *
  53  */
  54
  55 #include <linux/types.h>
  56 #include <linux/mm.h>
  57 #include <linux/capability.h>
  58 #include <linux/fcntl.h>
  59 #include <linux/socket.h>
  60 #include <linux/in.h>
  61 #include <linux/inet.h>
  62 #include <linux/netdevice.h>
  63 #include <linux/if_packet.h>
  64 #include <linux/wireless.h>
  65 #include <linux/kernel.h>
  66 #include <linux/kmod.h>
  67 #include <linux/slab.h>
  68 #include <linux/vmalloc.h>
  69 #include <net/net_namespace.h>
  70 #include <net/ip.h>
  71 #include <net/protocol.h>
  72 #include <linux/skbuff.h>
  73 #include <net/sock.h>
  74 #include <linux/errno.h>
  75 #include <linux/timer.h>
  76 #include <asm/uaccess.h>
  77 #include <asm/ioctls.h>
  78 #include <asm/page.h>
  79 #include <asm/cacheflush.h>
  80 #include <asm/io.h>
  81 #include <linux/proc_fs.h>
  82 #include <linux/seq_file.h>
  83 #include <linux/poll.h>
  84 #include <linux/module.h>
  85 #include <linux/init.h>
  86 #include <linux/mutex.h>
  87 #include <linux/if_vlan.h>
  88 #include <linux/virtio_net.h>
  89 #include <linux/errqueue.h>
  90 #include <linux/net_tstamp.h>
  91 #include <linux/percpu.h>
  92 #ifdef CONFIG_INET
  93 #include <net/inet_common.h>
  94 #endif
  95 #include <linux/bpf.h>
  96
  97 #include "internal.h"
  98
  99 /*
 100    Assumptions:
 101    - if device has no dev->hard_header routine, it adds and removes ll header
 102      inside itself. In this case ll header is invisible outside of device,
 103      but higher levels still should reserve dev->hard_header_len.
 104      Some devices are enough clever to reallocate skb, when header
 105      will not fit to reserved space (tunnel), another ones are silly
 106      (PPP).
 107    - packet socket receives packets with pulled ll header,
 108      so that SOCK_RAW should push it back.
 109
 110 On receive:
 111 -----------
 112
 113 Incoming, dev->hard_header!=NULL
 114    mac_header -> ll header
 115    data       -> data
 116
 117 Outgoing, dev->hard_header!=NULL
 118    mac_header -> ll header
 119    data       -> ll header
 120
 121 Incoming, dev->hard_header==NULL
 122    mac_header -> UNKNOWN position. It is very likely, that it points to ll
 123                  header.  PPP makes it, that is wrong, because introduce
 124                  assymetry between rx and tx paths.
 125    data       -> data
 126
 127 Outgoing, dev->hard_header==NULL
 128    mac_header -> data. ll header is still not built!
 129    data       -> data
 130
 131 Resume
 132   If dev->hard_header==NULL we are unlikely to restore sensible ll header.
 133
 134
 135 On transmit:
 136 ------------
 137
 138 dev->hard_header != NULL
 139    mac_header -> ll header
 140    data       -> ll header
 141
 142 dev->hard_header == NULL (ll header is added by device, we cannot control it)
 143    mac_header -> data
 144    data       -> data
 145
 146    We should set nh.raw on output to correct posistion,
 147    packet classifier depends on it.
 148  */
 149
 150 /* Private packet socket structures. */
 151
 152 /* identical to struct packet_mreq except it has
 153  * a longer address field.
 154  */
 155 struct packet_mreq_max {
 156         int             mr_ifindex;
 157         unsigned short  mr_type;
 158         unsigned short  mr_alen;
 159         unsigned char   mr_address[MAX_ADDR_LEN];
 160 };
 161
 162 union tpacket_uhdr {
 163         struct tpacket_hdr  *h1;
 164         struct tpacket2_hdr *h2;
 165         struct tpacket3_hdr *h3;
 166         void *raw;
 167 };
 168
 169 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
 170                 int closing, int tx_ring);
 171
 172 #define V3_ALIGNMENT    (8)
 173
 174 #define BLK_HDR_LEN     (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
 175
 176 #define BLK_PLUS_PRIV(sz_of_priv) \
 177         (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
 178
 179 #define PGV_FROM_VMALLOC 1
 180
 181 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
 182 #define BLOCK_NUM_PKTS(x)       ((x)->hdr.bh1.num_pkts)
 183 #define BLOCK_O2FP(x)           ((x)->hdr.bh1.offset_to_first_pkt)
 184 #define BLOCK_LEN(x)            ((x)->hdr.bh1.blk_len)
 185 #define BLOCK_SNUM(x)           ((x)->hdr.bh1.seq_num)
 186 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
 187 #define BLOCK_PRIV(x)           ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
 188
 189 struct packet_sock;
 190 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
 191 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
 192                        struct packet_type *pt, struct net_device *orig_dev);
 193
 194 static void *packet_previous_frame(struct packet_sock *po,
 195                 struct packet_ring_buffer *rb,
 196                 int status);
 197 static void packet_increment_head(struct packet_ring_buffer *buff);
 198 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
 199                         struct tpacket_block_desc *);
 200 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
 201                         struct packet_sock *);
 202 static void prb_retire_current_block(struct tpacket_kbdq_core *,
 203                 struct packet_sock *, unsigned int status);
 204 static int prb_queue_frozen(struct tpacket_kbdq_core *);
 205 static void prb_open_block(struct tpacket_kbdq_core *,
 206                 struct tpacket_block_desc *);
 207 static void prb_retire_rx_blk_timer_expired(unsigned long);
 208 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
 209 static void prb_init_blk_timer(struct packet_sock *,
 210                 struct tpacket_kbdq_core *,
 211                 void (*func) (unsigned long));
 212 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
 213 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
 214                 struct tpacket3_hdr *);
 215 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
 216                 struct tpacket3_hdr *);
 217 static void packet_flush_mclist(struct sock *sk);
 218
 219 struct packet_skb_cb {
 220         union {
 221                 struct sockaddr_pkt pkt;
 222                 union {
 223                         /* Trick: alias skb original length with
 224                          * ll.sll_family and ll.protocol in order
 225                          * to save room.
 226                          */
 227                         unsigned int origlen;
 228                         struct sockaddr_ll ll;
 229                 };
 230         } sa;
 231 };
 232
 233 #define vio_le() virtio_legacy_is_little_endian()
 234
 235 #define PACKET_SKB_CB(__skb)    ((struct packet_skb_cb *)((__skb)->cb))
 236
 237 #define GET_PBDQC_FROM_RB(x)    ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
 238 #define GET_PBLOCK_DESC(x, bid) \
 239         ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
 240 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x)       \
 241         ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
 242 #define GET_NEXT_PRB_BLK_NUM(x) \
 243         (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
 244         ((x)->kactive_blk_num+1) : 0)
 245
 246 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
 247 static void __fanout_link(struct sock *sk, struct packet_sock *po);
 248
 249 static int packet_direct_xmit(struct sk_buff *skb)
 250 {
 251         struct net_device *dev = skb->dev;
 252         struct sk_buff *orig_skb = skb;
 253         struct netdev_queue *txq;
 254         int ret = NETDEV_TX_BUSY;
 255
 256         if (unlikely(!netif_running(dev) ||
 257                      !netif_carrier_ok(dev)))
 258                 goto drop;
 259
 260         skb = validate_xmit_skb_list(skb, dev);
 261         if (skb != orig_skb)
 262                 goto drop;
 263
 264         txq = skb_get_tx_queue(dev, skb);
 265
 266         local_bh_disable();
 267
 268         HARD_TX_LOCK(dev, txq, smp_processor_id());
 269         if (!netif_xmit_frozen_or_drv_stopped(txq))
 270                 ret = netdev_start_xmit(skb, dev, txq, false);
 271         HARD_TX_UNLOCK(dev, txq);
 272
 273         local_bh_enable();
 274
 275         if (!dev_xmit_complete(ret))
 276                 kfree_skb(skb);
 277
 278         return ret;
 279 drop:
 280         atomic_long_inc(&dev->tx_dropped);
 281         kfree_skb_list(skb);
 282         return NET_XMIT_DROP;
 283 }
 284
 285 static struct net_device *packet_cached_dev_get(struct packet_sock *po)
 286 {
 287         struct net_device *dev;
 288
 289         rcu_read_lock();
 290         dev = rcu_dereference(po->cached_dev);
 291         if (likely(dev))
 292                 dev_hold(dev);
 293         rcu_read_unlock();
 294
 295         return dev;
 296 }
 297
 298 static void packet_cached_dev_assign(struct packet_sock *po,
 299                                      struct net_device *dev)
 300 {
 301         rcu_assign_pointer(po->cached_dev, dev);
 302 }
 303
 304 static void packet_cached_dev_reset(struct packet_sock *po)
 305 {
 306         RCU_INIT_POINTER(po->cached_dev, NULL);
 307 }
 308
 309 static bool packet_use_direct_xmit(const struct packet_sock *po)
 310 {
 311         return po->xmit == packet_direct_xmit;
 312 }
 313
 314 static u16 __packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
 315 {
 316         return (u16) raw_smp_processor_id() % dev->real_num_tx_queues;
 317 }
 318
 319 static void packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
 320 {
 321         const struct net_device_ops *ops = dev->netdev_ops;
 322         u16 queue_index;
 323
 324         if (ops->ndo_select_queue) {
 325                 queue_index = ops->ndo_select_queue(dev, skb, NULL,
 326                                                     __packet_pick_tx_queue);
 327                 queue_index = netdev_cap_txqueue(dev, queue_index);
 328         } else {
 329                 queue_index = __packet_pick_tx_queue(dev, skb);
 330         }
 331
 332         skb_set_queue_mapping(skb, queue_index);
 333 }
 334
 335 /* register_prot_hook must be invoked with the po->bind_lock held,
 336  * or from a context in which asynchronous accesses to the packet
 337  * socket is not possible (packet_create()).
 338  */
 339 static void register_prot_hook(struct sock *sk)
 340 {
 341         struct packet_sock *po = pkt_sk(sk);
 342
 343         if (!po->running) {
 344                 if (po->fanout)
 345                         __fanout_link(sk, po);
 346                 else
 347                         dev_add_pack(&po->prot_hook);
 348
 349                 sock_hold(sk);
 350                 po->running = 1;
 351         }
 352 }
 353
 354 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
 355  * held.   If the sync parameter is true, we will temporarily drop
 356  * the po->bind_lock and do a synchronize_net to make sure no
 357  * asynchronous packet processing paths still refer to the elements
 358  * of po->prot_hook.  If the sync parameter is false, it is the
 359  * callers responsibility to take care of this.
 360  */
 361 static void __unregister_prot_hook(struct sock *sk, bool sync)
 362 {
 363         struct packet_sock *po = pkt_sk(sk);
 364
 365         po->running = 0;
 366
 367         if (po->fanout)
 368                 __fanout_unlink(sk, po);
 369         else
 370                 __dev_remove_pack(&po->prot_hook);
 371
 372         __sock_put(sk);
 373
 374         if (sync) {
 375                 spin_unlock(&po->bind_lock);
 376                 synchronize_net();
 377                 spin_lock(&po->bind_lock);
 378         }
 379 }
 380
 381 static void unregister_prot_hook(struct sock *sk, bool sync)
 382 {
 383         struct packet_sock *po = pkt_sk(sk);
 384
 385         if (po->running)
 386                 __unregister_prot_hook(sk, sync);
 387 }
 388
 389 static inline struct page * __pure pgv_to_page(void *addr)
 390 {
 391         if (is_vmalloc_addr(addr))
 392                 return vmalloc_to_page(addr);
 393         return virt_to_page(addr);
 394 }
 395
 396 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
 397 {
 398         union tpacket_uhdr h;
 399
 400         h.raw = frame;
 401         switch (po->tp_version) {
 402         case TPACKET_V1:
 403                 h.h1->tp_status = status;
 404                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 405                 break;
 406         case TPACKET_V2:
 407                 h.h2->tp_status = status;
 408                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 409                 break;
 410         case TPACKET_V3:
 411         default:
 412                 WARN(1, "TPACKET version not supported.\n");
 413                 BUG();
 414         }
 415
 416         smp_wmb();
 417 }
 418
 419 static int __packet_get_status(struct packet_sock *po, void *frame)
 420 {
 421         union tpacket_uhdr h;
 422
 423         smp_rmb();
 424
 425         h.raw = frame;
 426         switch (po->tp_version) {
 427         case TPACKET_V1:
 428                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 429                 return h.h1->tp_status;
 430         case TPACKET_V2:
 431                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 432                 return h.h2->tp_status;
 433         case TPACKET_V3:
 434         default:
 435                 WARN(1, "TPACKET version not supported.\n");
 436                 BUG();
 437                 return 0;
 438         }
 439 }
 440
 441 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
 442                                    unsigned int flags)
 443 {
 444         struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
 445
 446         if (shhwtstamps &&
 447             (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
 448             ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
 449                 return TP_STATUS_TS_RAW_HARDWARE;
 450
 451         if (ktime_to_timespec_cond(skb->tstamp, ts))
 452                 return TP_STATUS_TS_SOFTWARE;
 453
 454         return 0;
 455 }
 456
 457 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
 458                                     struct sk_buff *skb)
 459 {
 460         union tpacket_uhdr h;
 461         struct timespec ts;
 462         __u32 ts_status;
 463
 464         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
 465                 return 0;
 466
 467         h.raw = frame;
 468         switch (po->tp_version) {
 469         case TPACKET_V1:
 470                 h.h1->tp_sec = ts.tv_sec;
 471                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
 472                 break;
 473         case TPACKET_V2:
 474                 h.h2->tp_sec = ts.tv_sec;
 475                 h.h2->tp_nsec = ts.tv_nsec;
 476                 break;
 477         case TPACKET_V3:
 478         default:
 479                 WARN(1, "TPACKET version not supported.\n");
 480                 BUG();
 481         }
 482
 483         /* one flush is safe, as both fields always lie on the same cacheline */
 484         flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
 485         smp_wmb();
 486
 487         return ts_status;
 488 }
 489
 490 static void *packet_lookup_frame(struct packet_sock *po,
 491                 struct packet_ring_buffer *rb,
 492                 unsigned int position,
 493                 int status)
 494 {
 495         unsigned int pg_vec_pos, frame_offset;
 496         union tpacket_uhdr h;
 497
 498         pg_vec_pos = position / rb->frames_per_block;
 499         frame_offset = position % rb->frames_per_block;
 500
 501         h.raw = rb->pg_vec[pg_vec_pos].buffer +
 502                 (frame_offset * rb->frame_size);
 503
 504         if (status != __packet_get_status(po, h.raw))
 505                 return NULL;
 506
 507         return h.raw;
 508 }
 509
 510 static void *packet_current_frame(struct packet_sock *po,
 511                 struct packet_ring_buffer *rb,
 512                 int status)
 513 {
 514         return packet_lookup_frame(po, rb, rb->head, status);
 515 }
 516
 517 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 518 {
 519         del_timer_sync(&pkc->retire_blk_timer);
 520 }
 521
 522 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
 523                 struct sk_buff_head *rb_queue)
 524 {
 525         struct tpacket_kbdq_core *pkc;
 526
 527         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
 528
 529         spin_lock_bh(&rb_queue->lock);
 530         pkc->delete_blk_timer = 1;
 531         spin_unlock_bh(&rb_queue->lock);
 532
 533         prb_del_retire_blk_timer(pkc);
 534 }
 535
 536 static void prb_init_blk_timer(struct packet_sock *po,
 537                 struct tpacket_kbdq_core *pkc,
 538                 void (*func) (unsigned long))
 539 {
 540         init_timer(&pkc->retire_blk_timer);
 541         pkc->retire_blk_timer.data = (long)po;
 542         pkc->retire_blk_timer.function = func;
 543         pkc->retire_blk_timer.expires = jiffies;
 544 }
 545
 546 static void prb_setup_retire_blk_timer(struct packet_sock *po)
 547 {
 548         struct tpacket_kbdq_core *pkc;
 549
 550         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
 551         prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
 552 }
 553
 554 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
 555                                 int blk_size_in_bytes)
 556 {
 557         struct net_device *dev;
 558         unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
 559         struct ethtool_cmd ecmd;
 560         int err;
 561         u32 speed;
 562
 563         rtnl_lock();
 564         dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
 565         if (unlikely(!dev)) {
 566                 rtnl_unlock();
 567                 return DEFAULT_PRB_RETIRE_TOV;
 568         }
 569         err = __ethtool_get_settings(dev, &ecmd);
 570         speed = ethtool_cmd_speed(&ecmd);
 571         rtnl_unlock();
 572         if (!err) {
 573                 /*
 574                  * If the link speed is so slow you don't really
 575                  * need to worry about perf anyways
 576                  */
 577                 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) {
 578                         return DEFAULT_PRB_RETIRE_TOV;
 579                 } else {
 580                         msec = 1;
 581                         div = speed / 1000;
 582                 }
 583         }
 584
 585         mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
 586
 587         if (div)
 588                 mbits /= div;
 589
 590         tmo = mbits * msec;
 591
 592         if (div)
 593                 return tmo+1;
 594         return tmo;
 595 }
 596
 597 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
 598                         union tpacket_req_u *req_u)
 599 {
 600         p1->feature_req_word = req_u->req3.tp_feature_req_word;
 601 }
 602
 603 static void init_prb_bdqc(struct packet_sock *po,
 604                         struct packet_ring_buffer *rb,
 605                         struct pgv *pg_vec,
 606                         union tpacket_req_u *req_u)
 607 {
 608         struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
 609         struct tpacket_block_desc *pbd;
 610
 611         memset(p1, 0x0, sizeof(*p1));
 612
 613         p1->knxt_seq_num = 1;
 614         p1->pkbdq = pg_vec;
 615         pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
 616         p1->pkblk_start = pg_vec[0].buffer;
 617         p1->kblk_size = req_u->req3.tp_block_size;
 618         p1->knum_blocks = req_u->req3.tp_block_nr;
 619         p1->hdrlen = po->tp_hdrlen;
 620         p1->version = po->tp_version;
 621         p1->last_kactive_blk_num = 0;
 622         po->stats.stats3.tp_freeze_q_cnt = 0;
 623         if (req_u->req3.tp_retire_blk_tov)
 624                 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
 625         else
 626                 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
 627                                                 req_u->req3.tp_block_size);
 628         p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
 629         p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
 630
 631         p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
 632         prb_init_ft_ops(p1, req_u);
 633         prb_setup_retire_blk_timer(po);
 634         prb_open_block(p1, pbd);
 635 }
 636
 637 /*  Do NOT update the last_blk_num first.
 638  *  Assumes sk_buff_head lock is held.
 639  */
 640 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 641 {
 642         mod_timer(&pkc->retire_blk_timer,
 643                         jiffies + pkc->tov_in_jiffies);
 644         pkc->last_kactive_blk_num = pkc->kactive_blk_num;
 645 }
 646
 647 /*
 648  * Timer logic:
 649  * 1) We refresh the timer only when we open a block.
 650  *    By doing this we don't waste cycles refreshing the timer
 651  *        on packet-by-packet basis.
 652  *
 653  * With a 1MB block-size, on a 1Gbps line, it will take
 654  * i) ~8 ms to fill a block + ii) memcpy etc.
 655  * In this cut we are not accounting for the memcpy time.
 656  *
 657  * So, if the user sets the 'tmo' to 10ms then the timer
 658  * will never fire while the block is still getting filled
 659  * (which is what we want). However, the user could choose
 660  * to close a block early and that's fine.
 661  *
 662  * But when the timer does fire, we check whether or not to refresh it.
 663  * Since the tmo granularity is in msecs, it is not too expensive
 664  * to refresh the timer, lets say every '8' msecs.
 665  * Either the user can set the 'tmo' or we can derive it based on
 666  * a) line-speed and b) block-size.
 667  * prb_calc_retire_blk_tmo() calculates the tmo.
 668  *
 669  */
 670 static void prb_retire_rx_blk_timer_expired(unsigned long data)
 671 {
 672         struct packet_sock *po = (struct packet_sock *)data;
 673         struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
 674         unsigned int frozen;
 675         struct tpacket_block_desc *pbd;
 676
 677         spin_lock(&po->sk.sk_receive_queue.lock);
 678
 679         frozen = prb_queue_frozen(pkc);
 680         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 681
 682         if (unlikely(pkc->delete_blk_timer))
 683                 goto out;
 684
 685         /* We only need to plug the race when the block is partially filled.
 686          * tpacket_rcv:
 687          *              lock(); increment BLOCK_NUM_PKTS; unlock()
 688          *              copy_bits() is in progress ...
 689          *              timer fires on other cpu:
 690          *              we can't retire the current block because copy_bits
 691          *              is in progress.
 692          *
 693          */
 694         if (BLOCK_NUM_PKTS(pbd)) {
 695                 while (atomic_read(&pkc->blk_fill_in_prog)) {
 696                         /* Waiting for skb_copy_bits to finish... */
 697                         cpu_relax();
 698                 }
 699         }
 700
 701         if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
 702                 if (!frozen) {
 703                         if (!BLOCK_NUM_PKTS(pbd)) {
 704                                 /* An empty block. Just refresh the timer. */
 705                                 goto refresh_timer;
 706                         }
 707                         prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
 708                         if (!prb_dispatch_next_block(pkc, po))
 709                                 goto refresh_timer;
 710                         else
 711                                 goto out;
 712                 } else {
 713                         /* Case 1. Queue was frozen because user-space was
 714                          *         lagging behind.
 715                          */
 716                         if (prb_curr_blk_in_use(pkc, pbd)) {
 717                                 /*
 718                                  * Ok, user-space is still behind.
 719                                  * So just refresh the timer.
 720                                  */
 721                                 goto refresh_timer;
 722                         } else {
 723                                /* Case 2. queue was frozen,user-space caught up,
 724                                 * now the link went idle && the timer fired.
 725                                 * We don't have a block to close.So we open this
 726                                 * block and restart the timer.
 727                                 * opening a block thaws the queue,restarts timer
 728                                 * Thawing/timer-refresh is a side effect.
 729                                 */
 730                                 prb_open_block(pkc, pbd);
 731                                 goto out;
 732                         }
 733                 }
 734         }
 735
 736 refresh_timer:
 737         _prb_refresh_rx_retire_blk_timer(pkc);
 738
 739 out:
 740         spin_unlock(&po->sk.sk_receive_queue.lock);
 741 }
 742
 743 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
 744                 struct tpacket_block_desc *pbd1, __u32 status)
 745 {
 746         /* Flush everything minus the block header */
 747
 748 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 749         u8 *start, *end;
 750
 751         start = (u8 *)pbd1;
 752
 753         /* Skip the block header(we know header WILL fit in 4K) */
 754         start += PAGE_SIZE;
 755
 756         end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
 757         for (; start < end; start += PAGE_SIZE)
 758                 flush_dcache_page(pgv_to_page(start));
 759
 760         smp_wmb();
 761 #endif
 762
 763         /* Now update the block status. */
 764
 765         BLOCK_STATUS(pbd1) = status;
 766
 767         /* Flush the block header */
 768
 769 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 770         start = (u8 *)pbd1;
 771         flush_dcache_page(pgv_to_page(start));
 772
 773         smp_wmb();
 774 #endif
 775 }
 776
 777 /*
 778  * Side effect:
 779  *
 780  * 1) flush the block
 781  * 2) Increment active_blk_num
 782  *
 783  * Note:We DONT refresh the timer on purpose.
 784  *      Because almost always the next block will be opened.
 785  */
 786 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
 787                 struct tpacket_block_desc *pbd1,
 788                 struct packet_sock *po, unsigned int stat)
 789 {
 790         __u32 status = TP_STATUS_USER | stat;
 791
 792         struct tpacket3_hdr *last_pkt;
 793         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 794         struct sock *sk = &po->sk;
 795
 796         if (po->stats.stats3.tp_drops)
 797                 status |= TP_STATUS_LOSING;
 798
 799         last_pkt = (struct tpacket3_hdr *)pkc1->prev;
 800         last_pkt->tp_next_offset = 0;
 801
 802         /* Get the ts of the last pkt */
 803         if (BLOCK_NUM_PKTS(pbd1)) {
 804                 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
 805                 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
 806         } else {
 807                 /* Ok, we tmo'd - so get the current time.
 808                  *
 809                  * It shouldn't really happen as we don't close empty
 810                  * blocks. See prb_retire_rx_blk_timer_expired().
 811                  */
 812                 struct timespec ts;
 813                 getnstimeofday(&ts);
 814                 h1->ts_last_pkt.ts_sec = ts.tv_sec;
 815                 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
 816         }
 817
 818         smp_wmb();
 819
 820         /* Flush the block */
 821         prb_flush_block(pkc1, pbd1, status);
 822
 823         sk->sk_data_ready(sk);
 824
 825         pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
 826 }
 827
 828 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
 829 {
 830         pkc->reset_pending_on_curr_blk = 0;
 831 }
 832
 833 /*
 834  * Side effect of opening a block:
 835  *
 836  * 1) prb_queue is thawed.
 837  * 2) retire_blk_timer is refreshed.
 838  *
 839  */
 840 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
 841         struct tpacket_block_desc *pbd1)
 842 {
 843         struct timespec ts;
 844         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 845
 846         smp_rmb();
 847
 848         /* We could have just memset this but we will lose the
 849          * flexibility of making the priv area sticky
 850          */
 851
 852         BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
 853         BLOCK_NUM_PKTS(pbd1) = 0;
 854         BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 855
 856         getnstimeofday(&ts);
 857
 858         h1->ts_first_pkt.ts_sec = ts.tv_sec;
 859         h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
 860
 861         pkc1->pkblk_start = (char *)pbd1;
 862         pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 863
 864         BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 865         BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
 866
 867         pbd1->version = pkc1->version;
 868         pkc1->prev = pkc1->nxt_offset;
 869         pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
 870
 871         prb_thaw_queue(pkc1);
 872         _prb_refresh_rx_retire_blk_timer(pkc1);
 873
 874         smp_wmb();
 875 }
 876
 877 /*
 878  * Queue freeze logic:
 879  * 1) Assume tp_block_nr = 8 blocks.
 880  * 2) At time 't0', user opens Rx ring.
 881  * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
 882  * 4) user-space is either sleeping or processing block '0'.
 883  * 5) tpacket_rcv is currently filling block '7', since there is no space left,
 884  *    it will close block-7,loop around and try to fill block '0'.
 885  *    call-flow:
 886  *    __packet_lookup_frame_in_block
 887  *      prb_retire_current_block()
 888  *      prb_dispatch_next_block()
 889  *        |->(BLOCK_STATUS == USER) evaluates to true
 890  *    5.1) Since block-0 is currently in-use, we just freeze the queue.
 891  * 6) Now there are two cases:
 892  *    6.1) Link goes idle right after the queue is frozen.
 893  *         But remember, the last open_block() refreshed the timer.
 894  *         When this timer expires,it will refresh itself so that we can
 895  *         re-open block-0 in near future.
 896  *    6.2) Link is busy and keeps on receiving packets. This is a simple
 897  *         case and __packet_lookup_frame_in_block will check if block-0
 898  *         is free and can now be re-used.
 899  */
 900 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
 901                                   struct packet_sock *po)
 902 {
 903         pkc->reset_pending_on_curr_blk = 1;
 904         po->stats.stats3.tp_freeze_q_cnt++;
 905 }
 906
 907 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
 908
 909 /*
 910  * If the next block is free then we will dispatch it
 911  * and return a good offset.
 912  * Else, we will freeze the queue.
 913  * So, caller must check the return value.
 914  */
 915 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
 916                 struct packet_sock *po)
 917 {
 918         struct tpacket_block_desc *pbd;
 919
 920         smp_rmb();
 921
 922         /* 1. Get current block num */
 923         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 924
 925         /* 2. If this block is currently in_use then freeze the queue */
 926         if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
 927                 prb_freeze_queue(pkc, po);
 928                 return NULL;
 929         }
 930
 931         /*
 932          * 3.
 933          * open this block and return the offset where the first packet
 934          * needs to get stored.
 935          */
 936         prb_open_block(pkc, pbd);
 937         return (void *)pkc->nxt_offset;
 938 }
 939
 940 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
 941                 struct packet_sock *po, unsigned int status)
 942 {
 943         struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 944
 945         /* retire/close the current block */
 946         if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
 947                 /*
 948                  * Plug the case where copy_bits() is in progress on
 949                  * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
 950                  * have space to copy the pkt in the current block and
 951                  * called prb_retire_current_block()
 952                  *
 953                  * We don't need to worry about the TMO case because
 954                  * the timer-handler already handled this case.
 955                  */
 956                 if (!(status & TP_STATUS_BLK_TMO)) {
 957                         while (atomic_read(&pkc->blk_fill_in_prog)) {
 958                                 /* Waiting for skb_copy_bits to finish... */
 959                                 cpu_relax();
 960                         }
 961                 }
 962                 prb_close_block(pkc, pbd, po, status);
 963                 return;
 964         }
 965 }
 966
 967 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
 968                                       struct tpacket_block_desc *pbd)
 969 {
 970         return TP_STATUS_USER & BLOCK_STATUS(pbd);
 971 }
 972
 973 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
 974 {
 975         return pkc->reset_pending_on_curr_blk;
 976 }
 977
 978 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
 979 {
 980         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
 981         atomic_dec(&pkc->blk_fill_in_prog);
 982 }
 983
 984 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
 985                         struct tpacket3_hdr *ppd)
 986 {
 987         ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
 988 }
 989
 990 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
 991                         struct tpacket3_hdr *ppd)
 992 {
 993         ppd->hv1.tp_rxhash = 0;
 994 }
 995
 996 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
 997                         struct tpacket3_hdr *ppd)
 998 {
 999         if (skb_vlan_tag_present(pkc->skb)) {
1000                 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
1001                 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
1002                 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
1003         } else {
1004                 ppd->hv1.tp_vlan_tci = 0;
1005                 ppd->hv1.tp_vlan_tpid = 0;
1006                 ppd->tp_status = TP_STATUS_AVAILABLE;
1007         }
1008 }
1009
1010 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
1011                         struct tpacket3_hdr *ppd)
1012 {
1013         ppd->hv1.tp_padding = 0;
1014         prb_fill_vlan_info(pkc, ppd);
1015
1016         if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
1017                 prb_fill_rxhash(pkc, ppd);
1018         else
1019                 prb_clear_rxhash(pkc, ppd);
1020 }
1021
1022 static void prb_fill_curr_block(char *curr,
1023                                 struct tpacket_kbdq_core *pkc,
1024                                 struct tpacket_block_desc *pbd,
1025                                 unsigned int len)
1026 {
1027         struct tpacket3_hdr *ppd;
1028
1029         ppd  = (struct tpacket3_hdr *)curr;
1030         ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1031         pkc->prev = curr;
1032         pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1033         BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1034         BLOCK_NUM_PKTS(pbd) += 1;
1035         atomic_inc(&pkc->blk_fill_in_prog);
1036         prb_run_all_ft_ops(pkc, ppd);
1037 }
1038
1039 /* Assumes caller has the sk->rx_queue.lock */
1040 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1041                                             struct sk_buff *skb,
1042                                                 int status,
1043                                             unsigned int len
1044                                             )
1045 {
1046         struct tpacket_kbdq_core *pkc;
1047         struct tpacket_block_desc *pbd;
1048         char *curr, *end;
1049
1050         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1051         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1052
1053         /* Queue is frozen when user space is lagging behind */
1054         if (prb_queue_frozen(pkc)) {
1055                 /*
1056                  * Check if that last block which caused the queue to freeze,
1057                  * is still in_use by user-space.
1058                  */
1059                 if (prb_curr_blk_in_use(pkc, pbd)) {
1060                         /* Can't record this packet */
1061                         return NULL;
1062                 } else {
1063                         /*
1064                          * Ok, the block was released by user-space.
1065                          * Now let's open that block.
1066                          * opening a block also thaws the queue.
1067                          * Thawing is a side effect.
1068                          */
1069                         prb_open_block(pkc, pbd);
1070                 }
1071         }
1072
1073         smp_mb();
1074         curr = pkc->nxt_offset;
1075         pkc->skb = skb;
1076         end = (char *)pbd + pkc->kblk_size;
1077
1078         /* first try the current block */
1079         if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1080                 prb_fill_curr_block(curr, pkc, pbd, len);
1081                 return (void *)curr;
1082         }
1083
1084         /* Ok, close the current block */
1085         prb_retire_current_block(pkc, po, 0);
1086
1087         /* Now, try to dispatch the next block */
1088         curr = (char *)prb_dispatch_next_block(pkc, po);
1089         if (curr) {
1090                 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1091                 prb_fill_curr_block(curr, pkc, pbd, len);
1092                 return (void *)curr;
1093         }
1094
1095         /*
1096          * No free blocks are available.user_space hasn't caught up yet.
1097          * Queue was just frozen and now this packet will get dropped.
1098          */
1099         return NULL;
1100 }
1101
1102 static void *packet_current_rx_frame(struct packet_sock *po,
1103                                             struct sk_buff *skb,
1104                                             int status, unsigned int len)
1105 {
1106         char *curr = NULL;
1107         switch (po->tp_version) {
1108         case TPACKET_V1:
1109         case TPACKET_V2:
1110                 curr = packet_lookup_frame(po, &po->rx_ring,
1111                                         po->rx_ring.head, status);
1112                 return curr;
1113         case TPACKET_V3:
1114                 return __packet_lookup_frame_in_block(po, skb, status, len);
1115         default:
1116                 WARN(1, "TPACKET version not supported\n");
1117                 BUG();
1118                 return NULL;
1119         }
1120 }
1121
1122 static void *prb_lookup_block(struct packet_sock *po,
1123                                      struct packet_ring_buffer *rb,
1124                                      unsigned int idx,
1125                                      int status)
1126 {
1127         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
1128         struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1129
1130         if (status != BLOCK_STATUS(pbd))
1131                 return NULL;
1132         return pbd;
1133 }
1134
1135 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1136 {
1137         unsigned int prev;
1138         if (rb->prb_bdqc.kactive_blk_num)
1139                 prev = rb->prb_bdqc.kactive_blk_num-1;
1140         else
1141                 prev = rb->prb_bdqc.knum_blocks-1;
1142         return prev;
1143 }
1144
1145 /* Assumes caller has held the rx_queue.lock */
1146 static void *__prb_previous_block(struct packet_sock *po,
1147                                          struct packet_ring_buffer *rb,
1148                                          int status)
1149 {
1150         unsigned int previous = prb_previous_blk_num(rb);
1151         return prb_lookup_block(po, rb, previous, status);
1152 }
1153
1154 static void *packet_previous_rx_frame(struct packet_sock *po,
1155                                              struct packet_ring_buffer *rb,
1156                                              int status)
1157 {
1158         if (po->tp_version <= TPACKET_V2)
1159                 return packet_previous_frame(po, rb, status);
1160
1161         return __prb_previous_block(po, rb, status);
1162 }
1163
1164 static void packet_increment_rx_head(struct packet_sock *po,
1165                                             struct packet_ring_buffer *rb)
1166 {
1167         switch (po->tp_version) {
1168         case TPACKET_V1:
1169         case TPACKET_V2:
1170                 return packet_increment_head(rb);
1171         case TPACKET_V3:
1172         default:
1173                 WARN(1, "TPACKET version not supported.\n");
1174                 BUG();
1175                 return;
1176         }
1177 }
1178
1179 static void *packet_previous_frame(struct packet_sock *po,
1180                 struct packet_ring_buffer *rb,
1181                 int status)
1182 {
1183         unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1184         return packet_lookup_frame(po, rb, previous, status);
1185 }
1186
1187 static void packet_increment_head(struct packet_ring_buffer *buff)
1188 {
1189         buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1190 }
1191
1192 static void packet_inc_pending(struct packet_ring_buffer *rb)
1193 {
1194         this_cpu_inc(*rb->pending_refcnt);
1195 }
1196
1197 static void packet_dec_pending(struct packet_ring_buffer *rb)
1198 {
1199         this_cpu_dec(*rb->pending_refcnt);
1200 }
1201
1202 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1203 {
1204         unsigned int refcnt = 0;
1205         int cpu;
1206
1207         /* We don't use pending refcount in rx_ring. */
1208         if (rb->pending_refcnt == NULL)
1209                 return 0;
1210
1211         for_each_possible_cpu(cpu)
1212                 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1213
1214         return refcnt;
1215 }
1216
1217 static int packet_alloc_pending(struct packet_sock *po)
1218 {
1219         po->rx_ring.pending_refcnt = NULL;
1220
1221         po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1222         if (unlikely(po->tx_ring.pending_refcnt == NULL))
1223                 return -ENOBUFS;
1224
1225         return 0;
1226 }
1227
1228 static void packet_free_pending(struct packet_sock *po)
1229 {
1230         free_percpu(po->tx_ring.pending_refcnt);
1231 }
1232
1233 #define ROOM_POW_OFF    2
1234 #define ROOM_NONE       0x0
1235 #define ROOM_LOW        0x1
1236 #define ROOM_NORMAL     0x2
1237
1238 static bool __tpacket_has_room(struct packet_sock *po, int pow_off)
1239 {
1240         int idx, len;
1241
1242         len = po->rx_ring.frame_max + 1;
1243         idx = po->rx_ring.head;
1244         if (pow_off)
1245                 idx += len >> pow_off;
1246         if (idx >= len)
1247                 idx -= len;
1248         return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1249 }
1250
1251 static bool __tpacket_v3_has_room(struct packet_sock *po, int pow_off)
1252 {
1253         int idx, len;
1254
1255         len = po->rx_ring.prb_bdqc.knum_blocks;
1256         idx = po->rx_ring.prb_bdqc.kactive_blk_num;
1257         if (pow_off)
1258                 idx += len >> pow_off;
1259         if (idx >= len)
1260                 idx -= len;
1261         return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1262 }
1263
1264 static int __packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1265 {
1266         struct sock *sk = &po->sk;
1267         int ret = ROOM_NONE;
1268
1269         if (po->prot_hook.func != tpacket_rcv) {
1270                 int avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1271                                           - (skb ? skb->truesize : 0);
1272                 if (avail > (sk->sk_rcvbuf >> ROOM_POW_OFF))
1273                         return ROOM_NORMAL;
1274                 else if (avail > 0)
1275                         return ROOM_LOW;
1276                 else
1277                         return ROOM_NONE;
1278         }
1279
1280         if (po->tp_version == TPACKET_V3) {
1281                 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1282                         ret = ROOM_NORMAL;
1283                 else if (__tpacket_v3_has_room(po, 0))
1284                         ret = ROOM_LOW;
1285         } else {
1286                 if (__tpacket_has_room(po, ROOM_POW_OFF))
1287                         ret = ROOM_NORMAL;
1288                 else if (__tpacket_has_room(po, 0))
1289                         ret = ROOM_LOW;
1290         }
1291
1292         return ret;
1293 }
1294
1295 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1296 {
1297         int ret;
1298         bool has_room;
1299
1300         spin_lock_bh(&po->sk.sk_receive_queue.lock);
1301         ret = __packet_rcv_has_room(po, skb);
1302         has_room = ret == ROOM_NORMAL;
1303         if (po->pressure == has_room)
1304                 po->pressure = !has_room;
1305         spin_unlock_bh(&po->sk.sk_receive_queue.lock);
1306
1307         return ret;
1308 }
1309
1310 static void packet_sock_destruct(struct sock *sk)
1311 {
1312         skb_queue_purge(&sk->sk_error_queue);
1313
1314         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1315         WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1316
1317         if (!sock_flag(sk, SOCK_DEAD)) {
1318                 pr_err("Attempt to release alive packet socket: %p\n", sk);
1319                 return;
1320         }
1321
1322         sk_refcnt_debug_dec(sk);
1323 }
1324
1325 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1326 {
1327         u32 rxhash;
1328         int i, count = 0;
1329
1330         rxhash = skb_get_hash(skb);
1331         for (i = 0; i < ROLLOVER_HLEN; i++)
1332                 if (po->rollover->history[i] == rxhash)
1333                         count++;
1334
1335         po->rollover->history[prandom_u32() % ROLLOVER_HLEN] = rxhash;
1336         return count > (ROLLOVER_HLEN >> 1);
1337 }
1338
1339 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1340                                       struct sk_buff *skb,
1341                                       unsigned int num)
1342 {
1343         return reciprocal_scale(__skb_get_hash_symmetric(skb), num);
1344 }
1345
1346 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1347                                     struct sk_buff *skb,
1348                                     unsigned int num)
1349 {
1350         unsigned int val = atomic_inc_return(&f->rr_cur);
1351
1352         return val % num;
1353 }
1354
1355 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1356                                      struct sk_buff *skb,
1357                                      unsigned int num)
1358 {
1359         return smp_processor_id() % num;
1360 }
1361
1362 static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1363                                      struct sk_buff *skb,
1364                                      unsigned int num)
1365 {
1366         return prandom_u32_max(num);
1367 }
1368
1369 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1370                                           struct sk_buff *skb,
1371                                           unsigned int idx, bool try_self,
1372                                           unsigned int num)
1373 {
1374         struct packet_sock *po, *po_next, *po_skip = NULL;
1375         unsigned int i, j, room = ROOM_NONE;
1376
1377         po = pkt_sk(f->arr[idx]);
1378
1379         if (try_self) {
1380                 room = packet_rcv_has_room(po, skb);
1381                 if (room == ROOM_NORMAL ||
1382                     (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1383                         return idx;
1384                 po_skip = po;
1385         }
1386
1387         i = j = min_t(int, po->rollover->sock, num - 1);
1388         do {
1389                 po_next = pkt_sk(f->arr[i]);
1390                 if (po_next != po_skip && !po_next->pressure &&
1391                     packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1392                         if (i != j)
1393                                 po->rollover->sock = i;
1394                         atomic_long_inc(&po->rollover->num);
1395                         if (room == ROOM_LOW)
1396                                 atomic_long_inc(&po->rollover->num_huge);
1397                         return i;
1398                 }
1399
1400                 if (++i == num)
1401                         i = 0;
1402         } while (i != j);
1403
1404         atomic_long_inc(&po->rollover->num_failed);
1405         return idx;
1406 }
1407
1408 static unsigned int fanout_demux_qm(struct packet_fanout *f,
1409                                     struct sk_buff *skb,
1410                                     unsigned int num)
1411 {
1412         return skb_get_queue_mapping(skb) % num;
1413 }
1414
1415 static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1416                                      struct sk_buff *skb,
1417                                      unsigned int num)
1418 {
1419         struct bpf_prog *prog;
1420         unsigned int ret = 0;
1421
1422         rcu_read_lock();
1423         prog = rcu_dereference(f->bpf_prog);
1424         if (prog)
1425                 ret = bpf_prog_run_clear_cb(prog, skb) % num;
1426         rcu_read_unlock();
1427
1428         return ret;
1429 }
1430
1431 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1432 {
1433         return f->flags & (flag >> 8);
1434 }
1435
1436 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1437                              struct packet_type *pt, struct net_device *orig_dev)
1438 {
1439         struct packet_fanout *f = pt->af_packet_priv;
1440         unsigned int num = READ_ONCE(f->num_members);
1441         struct net *net = read_pnet(&f->net);
1442         struct packet_sock *po;
1443         unsigned int idx;
1444
1445         if (!net_eq(dev_net(dev), net) || !num) {
1446                 kfree_skb(skb);
1447                 return 0;
1448         }
1449
1450         if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1451                 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1452                 if (!skb)
1453                         return 0;
1454         }
1455         switch (f->type) {
1456         case PACKET_FANOUT_HASH:
1457         default:
1458                 idx = fanout_demux_hash(f, skb, num);
1459                 break;
1460         case PACKET_FANOUT_LB:
1461                 idx = fanout_demux_lb(f, skb, num);
1462                 break;
1463         case PACKET_FANOUT_CPU:
1464                 idx = fanout_demux_cpu(f, skb, num);
1465                 break;
1466         case PACKET_FANOUT_RND:
1467                 idx = fanout_demux_rnd(f, skb, num);
1468                 break;
1469         case PACKET_FANOUT_QM:
1470                 idx = fanout_demux_qm(f, skb, num);
1471                 break;
1472         case PACKET_FANOUT_ROLLOVER:
1473                 idx = fanout_demux_rollover(f, skb, 0, false, num);
1474                 break;
1475         case PACKET_FANOUT_CBPF:
1476         case PACKET_FANOUT_EBPF:
1477                 idx = fanout_demux_bpf(f, skb, num);
1478                 break;
1479         }
1480
1481         if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1482                 idx = fanout_demux_rollover(f, skb, idx, true, num);
1483
1484         po = pkt_sk(f->arr[idx]);
1485         return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1486 }
1487
1488 DEFINE_MUTEX(fanout_mutex);
1489 EXPORT_SYMBOL_GPL(fanout_mutex);
1490 static LIST_HEAD(fanout_list);
1491
1492 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1493 {
1494         struct packet_fanout *f = po->fanout;
1495
1496         spin_lock(&f->lock);
1497         f->arr[f->num_members] = sk;
1498         smp_wmb();
1499         f->num_members++;
1500         spin_unlock(&f->lock);
1501 }
1502
1503 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1504 {
1505         struct packet_fanout *f = po->fanout;
1506         int i;
1507
1508         spin_lock(&f->lock);
1509         for (i = 0; i < f->num_members; i++) {
1510                 if (f->arr[i] == sk)
1511                         break;
1512         }
1513         BUG_ON(i >= f->num_members);
1514         f->arr[i] = f->arr[f->num_members - 1];
1515         f->num_members--;
1516         spin_unlock(&f->lock);
1517 }
1518
1519 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1520 {
1521         if (sk->sk_family != PF_PACKET)
1522                 return false;
1523
1524         return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1525 }
1526
1527 static void fanout_init_data(struct packet_fanout *f)
1528 {
1529         switch (f->type) {
1530         case PACKET_FANOUT_LB:
1531                 atomic_set(&f->rr_cur, 0);
1532                 break;
1533         case PACKET_FANOUT_CBPF:
1534         case PACKET_FANOUT_EBPF:
1535                 RCU_INIT_POINTER(f->bpf_prog, NULL);
1536                 break;
1537         }
1538 }
1539
1540 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1541 {
1542         struct bpf_prog *old;
1543
1544         spin_lock(&f->lock);
1545         old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1546         rcu_assign_pointer(f->bpf_prog, new);
1547         spin_unlock(&f->lock);
1548
1549         if (old) {
1550                 synchronize_net();
1551                 bpf_prog_destroy(old);
1552         }
1553 }
1554
1555 static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data,
1556                                 unsigned int len)
1557 {
1558         struct bpf_prog *new;
1559         struct sock_fprog fprog;
1560         int ret;
1561
1562         if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1563                 return -EPERM;
1564         if (len != sizeof(fprog))
1565                 return -EINVAL;
1566         if (copy_from_user(&fprog, data, len))
1567                 return -EFAULT;
1568
1569         ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1570         if (ret)
1571                 return ret;
1572
1573         __fanout_set_data_bpf(po->fanout, new);
1574         return 0;
1575 }
1576
1577 static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data,
1578                                 unsigned int len)
1579 {
1580         struct bpf_prog *new;
1581         u32 fd;
1582
1583         if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1584                 return -EPERM;
1585         if (len != sizeof(fd))
1586                 return -EINVAL;
1587         if (copy_from_user(&fd, data, len))
1588                 return -EFAULT;
1589
1590         new = bpf_prog_get(fd);
1591         if (IS_ERR(new))
1592                 return PTR_ERR(new);
1593         if (new->type != BPF_PROG_TYPE_SOCKET_FILTER) {
1594                 bpf_prog_put(new);
1595                 return -EINVAL;
1596         }
1597
1598         __fanout_set_data_bpf(po->fanout, new);
1599         return 0;
1600 }
1601
1602 static int fanout_set_data(struct packet_sock *po, char __user *data,
1603                            unsigned int len)
1604 {
1605         switch (po->fanout->type) {
1606         case PACKET_FANOUT_CBPF:
1607                 return fanout_set_data_cbpf(po, data, len);
1608         case PACKET_FANOUT_EBPF:
1609                 return fanout_set_data_ebpf(po, data, len);
1610         default:
1611                 return -EINVAL;
1612         };
1613 }
1614
1615 static void fanout_release_data(struct packet_fanout *f)
1616 {
1617         switch (f->type) {
1618         case PACKET_FANOUT_CBPF:
1619         case PACKET_FANOUT_EBPF:
1620                 __fanout_set_data_bpf(f, NULL);
1621         };
1622 }
1623
1624 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1625 {
1626         struct packet_rollover *rollover = NULL;
1627         struct packet_sock *po = pkt_sk(sk);
1628         struct packet_fanout *f, *match;
1629         u8 type = type_flags & 0xff;
1630         u8 flags = type_flags >> 8;
1631         int err;
1632
1633         switch (type) {
1634         case PACKET_FANOUT_ROLLOVER:
1635                 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1636                         return -EINVAL;
1637         case PACKET_FANOUT_HASH:
1638         case PACKET_FANOUT_LB:
1639         case PACKET_FANOUT_CPU:
1640         case PACKET_FANOUT_RND:
1641         case PACKET_FANOUT_QM:
1642         case PACKET_FANOUT_CBPF:
1643         case PACKET_FANOUT_EBPF:
1644                 break;
1645         default:
1646                 return -EINVAL;
1647         }
1648
1649         mutex_lock(&fanout_mutex);
1650
1651         err = -EINVAL;
1652         if (!po->running)
1653                 goto out;
1654
1655         err = -EALREADY;
1656         if (po->fanout)
1657                 goto out;
1658
1659         if (type == PACKET_FANOUT_ROLLOVER ||
1660             (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1661                 err = -ENOMEM;
1662                 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL);
1663                 if (!rollover)
1664                         goto out;
1665                 atomic_long_set(&rollover->num, 0);
1666                 atomic_long_set(&rollover->num_huge, 0);
1667                 atomic_long_set(&rollover->num_failed, 0);
1668                 po->rollover = rollover;
1669         }
1670
1671         match = NULL;
1672         list_for_each_entry(f, &fanout_list, list) {
1673                 if (f->id == id &&
1674                     read_pnet(&f->net) == sock_net(sk)) {
1675                         match = f;
1676                         break;
1677                 }
1678         }
1679         err = -EINVAL;
1680         if (match && match->flags != flags)
1681                 goto out;
1682         if (!match) {
1683                 err = -ENOMEM;
1684                 match = kzalloc(sizeof(*match), GFP_KERNEL);
1685                 if (!match)
1686                         goto out;
1687                 write_pnet(&match->net, sock_net(sk));
1688                 match->id = id;
1689                 match->type = type;
1690                 match->flags = flags;
1691                 INIT_LIST_HEAD(&match->list);
1692                 spin_lock_init(&match->lock);
1693                 atomic_set(&match->sk_ref, 0);
1694                 fanout_init_data(match);
1695                 match->prot_hook.type = po->prot_hook.type;
1696                 match->prot_hook.dev = po->prot_hook.dev;
1697                 match->prot_hook.func = packet_rcv_fanout;
1698                 match->prot_hook.af_packet_priv = match;
1699                 match->prot_hook.id_match = match_fanout_group;
1700                 dev_add_pack(&match->prot_hook);
1701                 list_add(&match->list, &fanout_list);
1702         }
1703         err = -EINVAL;
1704         if (match->type == type &&
1705             match->prot_hook.type == po->prot_hook.type &&
1706             match->prot_hook.dev == po->prot_hook.dev) {
1707                 err = -ENOSPC;
1708                 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1709                         __dev_remove_pack(&po->prot_hook);
1710                         po->fanout = match;
1711                         atomic_inc(&match->sk_ref);
1712                         __fanout_link(sk, po);
1713                         err = 0;
1714                 }
1715         }
1716 out:
1717         if (err && rollover) {
1718                 kfree(rollover);
1719                 po->rollover = NULL;
1720         }
1721         mutex_unlock(&fanout_mutex);
1722         return err;
1723 }
1724
1725 static void fanout_release(struct sock *sk)
1726 {
1727         struct packet_sock *po = pkt_sk(sk);
1728         struct packet_fanout *f;
1729
1730         mutex_lock(&fanout_mutex);
1731         f = po->fanout;
1732         if (f) {
1733                 po->fanout = NULL;
1734
1735                 if (atomic_dec_and_test(&f->sk_ref)) {
1736                         list_del(&f->list);
1737                         dev_remove_pack(&f->prot_hook);
1738                         fanout_release_data(f);
1739                         kfree(f);
1740                 }
1741
1742                 if (po->rollover)
1743                         kfree_rcu(po->rollover, rcu);
1744         }
1745         mutex_unlock(&fanout_mutex);
1746 }
1747
1748 static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1749                                           struct sk_buff *skb)
1750 {
1751         /* Earlier code assumed this would be a VLAN pkt, double-check
1752          * this now that we have the actual packet in hand. We can only
1753          * do this check on Ethernet devices.
1754          */
1755         if (unlikely(dev->type != ARPHRD_ETHER))
1756                 return false;
1757
1758         skb_reset_mac_header(skb);
1759         return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1760 }
1761
1762 static const struct proto_ops packet_ops;
1763
1764 static const struct proto_ops packet_ops_spkt;
1765
1766 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1767                            struct packet_type *pt, struct net_device *orig_dev)
1768 {
1769         struct sock *sk;
1770         struct sockaddr_pkt *spkt;
1771
1772         /*
1773          *      When we registered the protocol we saved the socket in the data
1774          *      field for just this event.
1775          */
1776
1777         sk = pt->af_packet_priv;
1778
1779         /*
1780          *      Yank back the headers [hope the device set this
1781          *      right or kerboom...]
1782          *
1783          *      Incoming packets have ll header pulled,
1784          *      push it back.
1785          *
1786          *      For outgoing ones skb->data == skb_mac_header(skb)
1787          *      so that this procedure is noop.
1788          */
1789
1790         if (skb->pkt_type == PACKET_LOOPBACK)
1791                 goto out;
1792
1793         if (!net_eq(dev_net(dev), sock_net(sk)))
1794                 goto out;
1795
1796         skb = skb_share_check(skb, GFP_ATOMIC);
1797         if (skb == NULL)
1798                 goto oom;
1799
1800         /* drop any routing info */
1801         skb_dst_drop(skb);
1802
1803         /* drop conntrack reference */
1804         nf_reset(skb);
1805
1806         spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1807
1808         skb_push(skb, skb->data - skb_mac_header(skb));
1809
1810         /*
1811          *      The SOCK_PACKET socket receives _all_ frames.
1812          */
1813
1814         spkt->spkt_family = dev->type;
1815         strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1816         spkt->spkt_protocol = skb->protocol;
1817
1818         /*
1819          *      Charge the memory to the socket. This is done specifically
1820          *      to prevent sockets using all the memory up.
1821          */
1822
1823         if (sock_queue_rcv_skb(sk, skb) == 0)
1824                 return 0;
1825
1826 out:
1827         kfree_skb(skb);
1828 oom:
1829         return 0;
1830 }
1831
1832
1833 /*
1834  *      Output a raw packet to a device layer. This bypasses all the other
1835  *      protocol layers and you must therefore supply it with a complete frame
1836  */
1837
1838 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1839                                size_t len)
1840 {
1841         struct sock *sk = sock->sk;
1842         DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1843         struct sk_buff *skb = NULL;
1844         struct net_device *dev;
1845         __be16 proto = 0;
1846         int err;
1847         int extra_len = 0;
1848
1849         /*
1850          *      Get and verify the address.
1851          */
1852
1853         if (saddr) {
1854                 if (msg->msg_namelen < sizeof(struct sockaddr))
1855                         return -EINVAL;
1856                 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1857                         proto = saddr->spkt_protocol;
1858         } else
1859                 return -ENOTCONN;       /* SOCK_PACKET must be sent giving an address */
1860
1861         /*
1862          *      Find the device first to size check it
1863          */
1864
1865         saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1866 retry:
1867         rcu_read_lock();
1868         dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1869         err = -ENODEV;
1870         if (dev == NULL)
1871                 goto out_unlock;
1872
1873         err = -ENETDOWN;
1874         if (!(dev->flags & IFF_UP))
1875                 goto out_unlock;
1876
1877         /*
1878          * You may not queue a frame bigger than the mtu. This is the lowest level
1879          * raw protocol and you must do your own fragmentation at this level.
1880          */
1881
1882         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1883                 if (!netif_supports_nofcs(dev)) {
1884                         err = -EPROTONOSUPPORT;
1885                         goto out_unlock;
1886                 }
1887                 extra_len = 4; /* We're doing our own CRC */
1888         }
1889
1890         err = -EMSGSIZE;
1891         if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1892                 goto out_unlock;
1893
1894         if (!skb) {
1895                 size_t reserved = LL_RESERVED_SPACE(dev);
1896                 int tlen = dev->needed_tailroom;
1897                 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1898
1899                 rcu_read_unlock();
1900                 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1901                 if (skb == NULL)
1902                         return -ENOBUFS;
1903                 /* FIXME: Save some space for broken drivers that write a hard
1904                  * header at transmission time by themselves. PPP is the notable
1905                  * one here. This should really be fixed at the driver level.
1906                  */
1907                 skb_reserve(skb, reserved);
1908                 skb_reset_network_header(skb);
1909
1910                 /* Try to align data part correctly */
1911                 if (hhlen) {
1912                         skb->data -= hhlen;
1913                         skb->tail -= hhlen;
1914                         if (len < hhlen)
1915                                 skb_reset_network_header(skb);
1916                 }
1917                 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1918                 if (err)
1919                         goto out_free;
1920                 goto retry;
1921         }
1922
1923         if (!dev_validate_header(dev, skb->data, len)) {
1924                 err = -EINVAL;
1925                 goto out_unlock;
1926         }
1927         if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
1928             !packet_extra_vlan_len_allowed(dev, skb)) {
1929                 err = -EMSGSIZE;
1930                 goto out_unlock;
1931         }
1932
1933         skb->protocol = proto;
1934         skb->dev = dev;
1935         skb->priority = sk->sk_priority;
1936         skb->mark = sk->sk_mark;
1937
1938         sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1939
1940         if (unlikely(extra_len == 4))
1941                 skb->no_fcs = 1;
1942
1943         skb_probe_transport_header(skb, 0);
1944
1945         dev_queue_xmit(skb);
1946         rcu_read_unlock();
1947         return len;
1948
1949 out_unlock:
1950         rcu_read_unlock();
1951 out_free:
1952         kfree_skb(skb);
1953         return err;
1954 }
1955
1956 static unsigned int run_filter(struct sk_buff *skb,
1957                                const struct sock *sk,
1958                                unsigned int res)
1959 {
1960         struct sk_filter *filter;
1961
1962         rcu_read_lock();
1963         filter = rcu_dereference(sk->sk_filter);
1964         if (filter != NULL)
1965                 res = bpf_prog_run_clear_cb(filter->prog, skb);
1966         rcu_read_unlock();
1967
1968         return res;
1969 }
1970
1971 /*
1972  * This function makes lazy skb cloning in hope that most of packets
1973  * are discarded by BPF.
1974  *
1975  * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1976  * and skb->cb are mangled. It works because (and until) packets
1977  * falling here are owned by current CPU. Output packets are cloned
1978  * by dev_queue_xmit_nit(), input packets are processed by net_bh
1979  * sequencially, so that if we return skb to original state on exit,
1980  * we will not harm anyone.
1981  */
1982
1983 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1984                       struct packet_type *pt, struct net_device *orig_dev)
1985 {
1986         struct sock *sk;
1987         struct sockaddr_ll *sll;
1988         struct packet_sock *po;
1989         u8 *skb_head = skb->data;
1990         int skb_len = skb->len;
1991         unsigned int snaplen, res;
1992
1993         if (skb->pkt_type == PACKET_LOOPBACK)
1994                 goto drop;
1995
1996         sk = pt->af_packet_priv;
1997         po = pkt_sk(sk);
1998
1999         if (!net_eq(dev_net(dev), sock_net(sk)))
2000                 goto drop;
2001
2002         skb->dev = dev;
2003
2004         if (dev->header_ops) {
2005                 /* The device has an explicit notion of ll header,
2006                  * exported to higher levels.
2007                  *
2008                  * Otherwise, the device hides details of its frame
2009                  * structure, so that corresponding packet head is
2010                  * never delivered to user.
2011                  */
2012                 if (sk->sk_type != SOCK_DGRAM)
2013                         skb_push(skb, skb->data - skb_mac_header(skb));
2014                 else if (skb->pkt_type == PACKET_OUTGOING) {
2015                         /* Special case: outgoing packets have ll header at head */
2016                         skb_pull(skb, skb_network_offset(skb));
2017                 }
2018         }
2019
2020         snaplen = skb->len;
2021
2022         res = run_filter(skb, sk, snaplen);
2023         if (!res)
2024                 goto drop_n_restore;
2025         if (snaplen > res)
2026                 snaplen = res;
2027
2028         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2029                 goto drop_n_acct;
2030
2031         if (skb_shared(skb)) {
2032                 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2033                 if (nskb == NULL)
2034                         goto drop_n_acct;
2035
2036                 if (skb_head != skb->data) {
2037                         skb->data = skb_head;
2038                         skb->len = skb_len;
2039                 }
2040                 consume_skb(skb);
2041                 skb = nskb;
2042         }
2043
2044         sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2045
2046         sll = &PACKET_SKB_CB(skb)->sa.ll;
2047         sll->sll_hatype = dev->type;
2048         sll->sll_pkttype = skb->pkt_type;
2049         if (unlikely(po->origdev))
2050                 sll->sll_ifindex = orig_dev->ifindex;
2051         else
2052                 sll->sll_ifindex = dev->ifindex;
2053
2054         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2055
2056         /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2057          * Use their space for storing the original skb length.
2058          */
2059         PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2060
2061         if (pskb_trim(skb, snaplen))
2062                 goto drop_n_acct;
2063
2064         skb_set_owner_r(skb, sk);
2065         skb->dev = NULL;
2066         skb_dst_drop(skb);
2067
2068         /* drop conntrack reference */
2069         nf_reset(skb);
2070
2071         spin_lock(&sk->sk_receive_queue.lock);
2072         po->stats.stats1.tp_packets++;
2073         sock_skb_set_dropcount(sk, skb);
2074         __skb_queue_tail(&sk->sk_receive_queue, skb);
2075         spin_unlock(&sk->sk_receive_queue.lock);
2076         sk->sk_data_ready(sk);
2077         return 0;
2078
2079 drop_n_acct:
2080         spin_lock(&sk->sk_receive_queue.lock);
2081         po->stats.stats1.tp_drops++;
2082         atomic_inc(&sk->sk_drops);
2083         spin_unlock(&sk->sk_receive_queue.lock);
2084
2085 drop_n_restore:
2086         if (skb_head != skb->data && skb_shared(skb)) {
2087                 skb->data = skb_head;
2088                 skb->len = skb_len;
2089         }
2090 drop:
2091         consume_skb(skb);
2092         return 0;
2093 }
2094
2095 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2096                        struct packet_type *pt, struct net_device *orig_dev)
2097 {
2098         struct sock *sk;
2099         struct packet_sock *po;
2100         struct sockaddr_ll *sll;
2101         union tpacket_uhdr h;
2102         u8 *skb_head = skb->data;
2103         int skb_len = skb->len;
2104         unsigned int snaplen, res;
2105         unsigned long status = TP_STATUS_USER;
2106         unsigned short macoff, netoff, hdrlen;
2107         struct sk_buff *copy_skb = NULL;
2108         struct timespec ts;
2109         __u32 ts_status;
2110
2111         /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2112          * We may add members to them until current aligned size without forcing
2113          * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2114          */
2115         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2116         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2117
2118         if (skb->pkt_type == PACKET_LOOPBACK)
2119                 goto drop;
2120
2121         sk = pt->af_packet_priv;
2122         po = pkt_sk(sk);
2123
2124         if (!net_eq(dev_net(dev), sock_net(sk)))
2125                 goto drop;
2126
2127         if (dev->header_ops) {
2128                 if (sk->sk_type != SOCK_DGRAM)
2129                         skb_push(skb, skb->data - skb_mac_header(skb));
2130                 else if (skb->pkt_type == PACKET_OUTGOING) {
2131                         /* Special case: outgoing packets have ll header at head */
2132                         skb_pull(skb, skb_network_offset(skb));
2133                 }
2134         }
2135
2136         snaplen = skb->len;
2137
2138         res = run_filter(skb, sk, snaplen);
2139         if (!res)
2140                 goto drop_n_restore;
2141
2142         if (skb->ip_summed == CHECKSUM_PARTIAL)
2143                 status |= TP_STATUS_CSUMNOTREADY;
2144         else if (skb->pkt_type != PACKET_OUTGOING &&
2145                  (skb->ip_summed == CHECKSUM_COMPLETE ||
2146                   skb_csum_unnecessary(skb)))
2147                 status |= TP_STATUS_CSUM_VALID;
2148
2149         if (snaplen > res)
2150                 snaplen = res;
2151
2152         if (sk->sk_type == SOCK_DGRAM) {
2153                 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2154                                   po->tp_reserve;
2155         } else {
2156                 unsigned int maclen = skb_network_offset(skb);
2157                 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2158                                        (maclen < 16 ? 16 : maclen)) +
2159                         po->tp_reserve;
2160                 macoff = netoff - maclen;
2161         }
2162         if (po->tp_version <= TPACKET_V2) {
2163                 if (macoff + snaplen > po->rx_ring.frame_size) {
2164                         if (po->copy_thresh &&
2165                             atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2166                                 if (skb_shared(skb)) {
2167                                         copy_skb = skb_clone(skb, GFP_ATOMIC);
2168                                 } else {
2169                                         copy_skb = skb_get(skb);
2170                                         skb_head = skb->data;
2171                                 }
2172                                 if (copy_skb)
2173                                         skb_set_owner_r(copy_skb, sk);
2174                         }
2175                         snaplen = po->rx_ring.frame_size - macoff;
2176                         if ((int)snaplen < 0)
2177                                 snaplen = 0;
2178                 }
2179         } else if (unlikely(macoff + snaplen >
2180                             GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2181                 u32 nval;
2182
2183                 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2184                 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2185                             snaplen, nval, macoff);
2186                 snaplen = nval;
2187                 if (unlikely((int)snaplen < 0)) {
2188                         snaplen = 0;
2189                         macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2190                 }
2191         }
2192         spin_lock(&sk->sk_receive_queue.lock);
2193         h.raw = packet_current_rx_frame(po, skb,
2194                                         TP_STATUS_KERNEL, (macoff+snaplen));
2195         if (!h.raw)
2196                 goto ring_is_full;
2197         if (po->tp_version <= TPACKET_V2) {
2198                 packet_increment_rx_head(po, &po->rx_ring);
2199         /*
2200          * LOSING will be reported till you read the stats,
2201          * because it's COR - Clear On Read.
2202          * Anyways, moving it for V1/V2 only as V3 doesn't need this
2203          * at packet level.
2204          */
2205                 if (po->stats.stats1.tp_drops)
2206                         status |= TP_STATUS_LOSING;
2207         }
2208         po->stats.stats1.tp_packets++;
2209         if (copy_skb) {
2210                 status |= TP_STATUS_COPY;
2211                 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2212         }
2213         spin_unlock(&sk->sk_receive_queue.lock);
2214
2215         skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2216
2217         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
2218                 getnstimeofday(&ts);
2219
2220         status |= ts_status;
2221
2222         switch (po->tp_version) {
2223         case TPACKET_V1:
2224                 h.h1->tp_len = skb->len;
2225                 h.h1->tp_snaplen = snaplen;
2226                 h.h1->tp_mac = macoff;
2227                 h.h1->tp_net = netoff;
2228                 h.h1->tp_sec = ts.tv_sec;
2229                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2230                 hdrlen = sizeof(*h.h1);
2231                 break;
2232         case TPACKET_V2:
2233                 h.h2->tp_len = skb->len;
2234                 h.h2->tp_snaplen = snaplen;
2235                 h.h2->tp_mac = macoff;
2236                 h.h2->tp_net = netoff;
2237                 h.h2->tp_sec = ts.tv_sec;
2238                 h.h2->tp_nsec = ts.tv_nsec;
2239                 if (skb_vlan_tag_present(skb)) {
2240                         h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2241                         h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2242                         status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2243                 } else {
2244                         h.h2->tp_vlan_tci = 0;
2245                         h.h2->tp_vlan_tpid = 0;
2246                 }
2247                 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2248                 hdrlen = sizeof(*h.h2);
2249                 break;
2250         case TPACKET_V3:
2251                 /* tp_nxt_offset,vlan are already populated above.
2252                  * So DONT clear those fields here
2253                  */
2254                 h.h3->tp_status |= status;
2255                 h.h3->tp_len = skb->len;
2256                 h.h3->tp_snaplen = snaplen;
2257                 h.h3->tp_mac = macoff;
2258                 h.h3->tp_net = netoff;
2259                 h.h3->tp_sec  = ts.tv_sec;
2260                 h.h3->tp_nsec = ts.tv_nsec;
2261                 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2262                 hdrlen = sizeof(*h.h3);
2263                 break;
2264         default:
2265                 BUG();
2266         }
2267
2268         sll = h.raw + TPACKET_ALIGN(hdrlen);
2269         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2270         sll->sll_family = AF_PACKET;
2271         sll->sll_hatype = dev->type;
2272         sll->sll_protocol = skb->protocol;
2273         sll->sll_pkttype = skb->pkt_type;
2274         if (unlikely(po->origdev))
2275                 sll->sll_ifindex = orig_dev->ifindex;
2276         else
2277                 sll->sll_ifindex = dev->ifindex;
2278
2279         smp_mb();
2280
2281 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2282         if (po->tp_version <= TPACKET_V2) {
2283                 u8 *start, *end;
2284
2285                 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2286                                         macoff + snaplen);
2287
2288                 for (start = h.raw; start < end; start += PAGE_SIZE)
2289                         flush_dcache_page(pgv_to_page(start));
2290         }
2291         smp_wmb();
2292 #endif
2293
2294         if (po->tp_version <= TPACKET_V2) {
2295                 __packet_set_status(po, h.raw, status);
2296                 sk->sk_data_ready(sk);
2297         } else {
2298                 prb_clear_blk_fill_status(&po->rx_ring);
2299         }
2300
2301 drop_n_restore:
2302         if (skb_head != skb->data && skb_shared(skb)) {
2303                 skb->data = skb_head;
2304                 skb->len = skb_len;
2305         }
2306 drop:
2307         kfree_skb(skb);
2308         return 0;
2309
2310 ring_is_full:
2311         po->stats.stats1.tp_drops++;
2312         spin_unlock(&sk->sk_receive_queue.lock);
2313
2314         sk->sk_data_ready(sk);
2315         kfree_skb(copy_skb);
2316         goto drop_n_restore;
2317 }
2318
2319 static void tpacket_destruct_skb(struct sk_buff *skb)
2320 {
2321         struct packet_sock *po = pkt_sk(skb->sk);
2322
2323         if (likely(po->tx_ring.pg_vec)) {
2324                 void *ph;
2325                 __u32 ts;
2326
2327                 ph = skb_shinfo(skb)->destructor_arg;
2328                 packet_dec_pending(&po->tx_ring);
2329
2330                 ts = __packet_set_timestamp(po, ph, skb);
2331                 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2332         }
2333
2334         sock_wfree(skb);
2335 }
2336
2337 static void tpacket_set_protocol(const struct net_device *dev,
2338                                  struct sk_buff *skb)
2339 {
2340         if (dev->type == ARPHRD_ETHER) {
2341                 skb_reset_mac_header(skb);
2342                 skb->protocol = eth_hdr(skb)->h_proto;
2343         }
2344 }
2345
2346 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2347                 void *frame, struct net_device *dev, int size_max,
2348                 __be16 proto, unsigned char *addr, int hlen)
2349 {
2350         union tpacket_uhdr ph;
2351         int to_write, offset, len, tp_len, nr_frags, len_max;
2352         struct socket *sock = po->sk.sk_socket;
2353         struct page *page;
2354         void *data;
2355         int err;
2356
2357         ph.raw = frame;
2358
2359         skb->protocol = proto;
2360         skb->dev = dev;
2361         skb->priority = po->sk.sk_priority;
2362         skb->mark = po->sk.sk_mark;
2363         sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags);
2364         skb_shinfo(skb)->destructor_arg = ph.raw;
2365
2366         switch (po->tp_version) {
2367         case TPACKET_V2:
2368                 tp_len = ph.h2->tp_len;
2369                 break;
2370         default:
2371                 tp_len = ph.h1->tp_len;
2372                 break;
2373         }
2374         if (unlikely(tp_len > size_max)) {
2375                 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2376                 return -EMSGSIZE;
2377         }
2378
2379         skb_reserve(skb, hlen);
2380         skb_reset_network_header(skb);
2381
2382         if (unlikely(po->tp_tx_has_off)) {
2383                 int off_min, off_max, off;
2384                 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2385                 off_max = po->tx_ring.frame_size - tp_len;
2386                 if (sock->type == SOCK_DGRAM) {
2387                         switch (po->tp_version) {
2388                         case TPACKET_V2:
2389                                 off = ph.h2->tp_net;
2390                                 break;
2391                         default:
2392                                 off = ph.h1->tp_net;
2393                                 break;
2394                         }
2395                 } else {
2396                         switch (po->tp_version) {
2397                         case TPACKET_V2:
2398                                 off = ph.h2->tp_mac;
2399                                 break;
2400                         default:
2401                                 off = ph.h1->tp_mac;
2402                                 break;
2403                         }
2404                 }
2405                 if (unlikely((off < off_min) || (off_max < off)))
2406                         return -EINVAL;
2407                 data = ph.raw + off;
2408         } else {
2409                 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
2410         }
2411         to_write = tp_len;
2412
2413         if (sock->type == SOCK_DGRAM) {
2414                 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2415                                 NULL, tp_len);
2416                 if (unlikely(err < 0))
2417                         return -EINVAL;
2418         } else if (dev->hard_header_len) {
2419                 int hdrlen = min_t(int, dev->hard_header_len, tp_len);
2420
2421                 skb_push(skb, dev->hard_header_len);
2422                 err = skb_store_bits(skb, 0, data, hdrlen);
2423                 if (unlikely(err))
2424                         return err;
2425                 if (!dev_validate_header(dev, skb->data, hdrlen))
2426                         return -EINVAL;
2427                 if (!skb->protocol)
2428                         tpacket_set_protocol(dev, skb);
2429
2430                 data += hdrlen;
2431                 to_write -= hdrlen;
2432         }
2433
2434         offset = offset_in_page(data);
2435         len_max = PAGE_SIZE - offset;
2436         len = ((to_write > len_max) ? len_max : to_write);
2437
2438         skb->data_len = to_write;
2439         skb->len += to_write;
2440         skb->truesize += to_write;
2441         atomic_add(to_write, &po->sk.sk_wmem_alloc);
2442
2443         while (likely(to_write)) {
2444                 nr_frags = skb_shinfo(skb)->nr_frags;
2445
2446                 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2447                         pr_err("Packet exceed the number of skb frags(%lu)\n",
2448                                MAX_SKB_FRAGS);
2449                         return -EFAULT;
2450                 }
2451
2452                 page = pgv_to_page(data);
2453                 data += len;
2454                 flush_dcache_page(page);
2455                 get_page(page);
2456                 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2457                 to_write -= len;
2458                 offset = 0;
2459                 len_max = PAGE_SIZE;
2460                 len = ((to_write > len_max) ? len_max : to_write);
2461         }
2462
2463         skb_probe_transport_header(skb, 0);
2464
2465         return tp_len;
2466 }
2467
2468 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2469 {
2470         struct sk_buff *skb;
2471         struct net_device *dev;
2472         __be16 proto;
2473         int err, reserve = 0;
2474         void *ph;
2475         DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2476         bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2477         int tp_len, size_max;
2478         unsigned char *addr;
2479         int len_sum = 0;
2480         int status = TP_STATUS_AVAILABLE;
2481         int hlen, tlen;
2482
2483         mutex_lock(&po->pg_vec_lock);
2484
2485         if (likely(saddr == NULL)) {
2486                 dev     = packet_cached_dev_get(po);
2487                 proto   = po->num;
2488                 addr    = NULL;
2489         } else {
2490                 err = -EINVAL;
2491                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2492                         goto out;
2493                 if (msg->msg_namelen < (saddr->sll_halen
2494                                         + offsetof(struct sockaddr_ll,
2495                                                 sll_addr)))
2496                         goto out;
2497                 proto   = saddr->sll_protocol;
2498                 addr    = saddr->sll_addr;
2499                 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2500         }
2501
2502         err = -ENXIO;
2503         if (unlikely(dev == NULL))
2504                 goto out;
2505         err = -ENETDOWN;
2506         if (unlikely(!(dev->flags & IFF_UP)))
2507                 goto out_put;
2508
2509         if (po->sk.sk_socket->type == SOCK_RAW)
2510                 reserve = dev->hard_header_len;
2511         size_max = po->tx_ring.frame_size
2512                 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2513
2514         if (size_max > dev->mtu + reserve + VLAN_HLEN)
2515                 size_max = dev->mtu + reserve + VLAN_HLEN;
2516
2517         do {
2518                 ph = packet_current_frame(po, &po->tx_ring,
2519                                           TP_STATUS_SEND_REQUEST);
2520                 if (unlikely(ph == NULL)) {
2521                         if (need_wait && need_resched())
2522                                 schedule();
2523                         continue;
2524                 }
2525
2526                 status = TP_STATUS_SEND_REQUEST;
2527                 hlen = LL_RESERVED_SPACE(dev);
2528                 tlen = dev->needed_tailroom;
2529                 skb = sock_alloc_send_skb(&po->sk,
2530                                 hlen + tlen + sizeof(struct sockaddr_ll),
2531                                 !need_wait, &err);
2532
2533                 if (unlikely(skb == NULL)) {
2534                         /* we assume the socket was initially writeable ... */
2535                         if (likely(len_sum > 0))
2536                                 err = len_sum;
2537                         goto out_status;
2538                 }
2539                 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2540                                           addr, hlen);
2541                 if (likely(tp_len >= 0) &&
2542                     tp_len > dev->mtu + reserve &&
2543                     !packet_extra_vlan_len_allowed(dev, skb))
2544                         tp_len = -EMSGSIZE;
2545
2546                 if (unlikely(tp_len < 0)) {
2547                         if (po->tp_loss) {
2548                                 __packet_set_status(po, ph,
2549                                                 TP_STATUS_AVAILABLE);
2550                                 packet_increment_head(&po->tx_ring);
2551                                 kfree_skb(skb);
2552                                 continue;
2553                         } else {
2554                                 status = TP_STATUS_WRONG_FORMAT;
2555                                 err = tp_len;
2556                                 goto out_status;
2557                         }
2558                 }
2559
2560                 packet_pick_tx_queue(dev, skb);
2561
2562                 skb->destructor = tpacket_destruct_skb;
2563                 __packet_set_status(po, ph, TP_STATUS_SENDING);
2564                 packet_inc_pending(&po->tx_ring);
2565
2566                 status = TP_STATUS_SEND_REQUEST;
2567                 err = po->xmit(skb);
2568                 if (unlikely(err > 0)) {
2569                         err = net_xmit_errno(err);
2570                         if (err && __packet_get_status(po, ph) ==
2571                                    TP_STATUS_AVAILABLE) {
2572                                 /* skb was destructed already */
2573                                 skb = NULL;
2574                                 goto out_status;
2575                         }
2576                         /*
2577                          * skb was dropped but not destructed yet;
2578                          * let's treat it like congestion or err < 0
2579                          */
2580                         err = 0;
2581                 }
2582                 packet_increment_head(&po->tx_ring);
2583                 len_sum += tp_len;
2584         } while (likely((ph != NULL) ||
2585                 /* Note: packet_read_pending() might be slow if we have
2586                  * to call it as it's per_cpu variable, but in fast-path
2587                  * we already short-circuit the loop with the first
2588                  * condition, and luckily don't have to go that path
2589                  * anyway.
2590                  */
2591                  (need_wait && packet_read_pending(&po->tx_ring))));
2592
2593         err = len_sum;
2594         goto out_put;
2595
2596 out_status:
2597         __packet_set_status(po, ph, status);
2598         kfree_skb(skb);
2599 out_put:
2600         dev_put(dev);
2601 out:
2602         mutex_unlock(&po->pg_vec_lock);
2603         return err;
2604 }
2605
2606 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2607                                         size_t reserve, size_t len,
2608                                         size_t linear, int noblock,
2609                                         int *err)
2610 {
2611         struct sk_buff *skb;
2612
2613         /* Under a page?  Don't bother with paged skb. */
2614         if (prepad + len < PAGE_SIZE || !linear)
2615                 linear = len;
2616
2617         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2618                                    err, 0);
2619         if (!skb)
2620                 return NULL;
2621
2622         skb_reserve(skb, reserve);
2623         skb_put(skb, linear);
2624         skb->data_len = len - linear;
2625         skb->len += len - linear;
2626
2627         return skb;
2628 }
2629
2630 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2631 {
2632         struct sock *sk = sock->sk;
2633         DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2634         struct sk_buff *skb;
2635         struct net_device *dev;
2636         __be16 proto;
2637         unsigned char *addr;
2638         int err, reserve = 0;
2639         struct sockcm_cookie sockc;
2640         struct virtio_net_hdr vnet_hdr = { 0 };
2641         int offset = 0;
2642         int vnet_hdr_len;
2643         struct packet_sock *po = pkt_sk(sk);
2644         unsigned short gso_type = 0;
2645         int hlen, tlen, linear;
2646         int extra_len = 0;
2647         ssize_t n;
2648
2649         /*
2650          *      Get and verify the address.
2651          */
2652
2653         if (likely(saddr == NULL)) {
2654                 dev     = packet_cached_dev_get(po);
2655                 proto   = po->num;
2656                 addr    = NULL;
2657         } else {
2658                 err = -EINVAL;
2659                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2660                         goto out;
2661                 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2662                         goto out;
2663                 proto   = saddr->sll_protocol;
2664                 addr    = saddr->sll_addr;
2665                 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2666         }
2667
2668         err = -ENXIO;
2669         if (unlikely(dev == NULL))
2670                 goto out_unlock;
2671         err = -ENETDOWN;
2672         if (unlikely(!(dev->flags & IFF_UP)))
2673                 goto out_unlock;
2674
2675         sockc.mark = sk->sk_mark;
2676         if (msg->msg_controllen) {
2677                 err = sock_cmsg_send(sk, msg, &sockc);
2678                 if (unlikely(err))
2679                         goto out_unlock;
2680         }
2681
2682         if (sock->type == SOCK_RAW)
2683                 reserve = dev->hard_header_len;
2684         if (po->has_vnet_hdr) {
2685                 vnet_hdr_len = sizeof(vnet_hdr);
2686
2687                 err = -EINVAL;
2688                 if (len < vnet_hdr_len)
2689                         goto out_unlock;
2690
2691                 len -= vnet_hdr_len;
2692
2693                 err = -EFAULT;
2694                 n = copy_from_iter(&vnet_hdr, vnet_hdr_len, &msg->msg_iter);
2695                 if (n != vnet_hdr_len)
2696                         goto out_unlock;
2697
2698                 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2699                     (__virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) +
2700                      __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2 >
2701                       __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len)))
2702                         vnet_hdr.hdr_len = __cpu_to_virtio16(vio_le(),
2703                                  __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) +
2704                                 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2);
2705
2706                 err = -EINVAL;
2707                 if (__virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len) > len)
2708                         goto out_unlock;
2709
2710                 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2711                         switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2712                         case VIRTIO_NET_HDR_GSO_TCPV4:
2713                                 gso_type = SKB_GSO_TCPV4;
2714                                 break;
2715                         case VIRTIO_NET_HDR_GSO_TCPV6:
2716                                 gso_type = SKB_GSO_TCPV6;
2717                                 break;
2718                         case VIRTIO_NET_HDR_GSO_UDP:
2719                                 gso_type = SKB_GSO_UDP;
2720                                 break;
2721                         default:
2722                                 goto out_unlock;
2723                         }
2724
2725                         if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2726                                 gso_type |= SKB_GSO_TCP_ECN;
2727
2728                         if (vnet_hdr.gso_size == 0)
2729                                 goto out_unlock;
2730
2731                 }
2732         }
2733
2734         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2735                 if (!netif_supports_nofcs(dev)) {
2736                         err = -EPROTONOSUPPORT;
2737                         goto out_unlock;
2738                 }
2739                 extra_len = 4; /* We're doing our own CRC */
2740         }
2741
2742         err = -EMSGSIZE;
2743         if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2744                 goto out_unlock;
2745
2746         err = -ENOBUFS;
2747         hlen = LL_RESERVED_SPACE(dev);
2748         tlen = dev->needed_tailroom;
2749         linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
2750         linear = max(linear, min_t(int, len, dev->hard_header_len));
2751         skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
2752                                msg->msg_flags & MSG_DONTWAIT, &err);
2753         if (skb == NULL)
2754                 goto out_unlock;
2755
2756         skb_set_network_header(skb, reserve);
2757
2758         err = -EINVAL;
2759         if (sock->type == SOCK_DGRAM) {
2760                 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2761                 if (unlikely(offset < 0))
2762                         goto out_free;
2763         }
2764
2765         /* Returns -EFAULT on error */
2766         err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2767         if (err)
2768                 goto out_free;
2769
2770         if (sock->type == SOCK_RAW &&
2771             !dev_validate_header(dev, skb->data, len)) {
2772                 err = -EINVAL;
2773                 goto out_free;
2774         }
2775
2776         sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2777
2778         if (!gso_type && (len > dev->mtu + reserve + extra_len) &&
2779             !packet_extra_vlan_len_allowed(dev, skb)) {
2780                 err = -EMSGSIZE;
2781                 goto out_free;
2782         }
2783
2784         skb->protocol = proto;
2785         skb->dev = dev;
2786         skb->priority = sk->sk_priority;
2787         skb->mark = sockc.mark;
2788
2789         packet_pick_tx_queue(dev, skb);
2790
2791         if (po->has_vnet_hdr) {
2792                 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2793                         u16 s = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start);
2794                         u16 o = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset);
2795                         if (!skb_partial_csum_set(skb, s, o)) {
2796                                 err = -EINVAL;
2797                                 goto out_free;
2798                         }
2799                 }
2800
2801                 skb_shinfo(skb)->gso_size =
2802                         __virtio16_to_cpu(vio_le(), vnet_hdr.gso_size);
2803                 skb_shinfo(skb)->gso_type = gso_type;
2804
2805                 /* Header must be checked, and gso_segs computed. */
2806                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2807                 skb_shinfo(skb)->gso_segs = 0;
2808
2809                 len += vnet_hdr_len;
2810         }
2811
2812         skb_probe_transport_header(skb, reserve);
2813
2814         if (unlikely(extra_len == 4))
2815                 skb->no_fcs = 1;
2816
2817         err = po->xmit(skb);
2818         if (err > 0 && (err = net_xmit_errno(err)) != 0)
2819                 goto out_unlock;
2820
2821         dev_put(dev);
2822
2823         return len;
2824
2825 out_free:
2826         kfree_skb(skb);
2827 out_unlock:
2828         if (dev)
2829                 dev_put(dev);
2830 out:
2831         return err;
2832 }
2833
2834 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2835 {
2836         struct sock *sk = sock->sk;
2837         struct packet_sock *po = pkt_sk(sk);
2838
2839         if (po->tx_ring.pg_vec)
2840                 return tpacket_snd(po, msg);
2841         else
2842                 return packet_snd(sock, msg, len);
2843 }
2844
2845 /*
2846  *      Close a PACKET socket. This is fairly simple. We immediately go
2847  *      to 'closed' state and remove our protocol entry in the device list.
2848  */
2849
2850 static int packet_release(struct socket *sock)
2851 {
2852         struct sock *sk = sock->sk;
2853         struct packet_sock *po;
2854         struct net *net;
2855         union tpacket_req_u req_u;
2856
2857         if (!sk)
2858                 return 0;
2859
2860         net = sock_net(sk);
2861         po = pkt_sk(sk);
2862
2863         mutex_lock(&net->packet.sklist_lock);
2864         sk_del_node_init_rcu(sk);
2865         mutex_unlock(&net->packet.sklist_lock);
2866
2867         preempt_disable();
2868         sock_prot_inuse_add(net, sk->sk_prot, -1);
2869         preempt_enable();
2870
2871         spin_lock(&po->bind_lock);
2872         unregister_prot_hook(sk, false);
2873         packet_cached_dev_reset(po);
2874
2875         if (po->prot_hook.dev) {
2876                 dev_put(po->prot_hook.dev);
2877                 po->prot_hook.dev = NULL;
2878         }
2879         spin_unlock(&po->bind_lock);
2880
2881         packet_flush_mclist(sk);
2882
2883         if (po->rx_ring.pg_vec) {
2884                 memset(&req_u, 0, sizeof(req_u));
2885                 packet_set_ring(sk, &req_u, 1, 0);
2886         }
2887
2888         if (po->tx_ring.pg_vec) {
2889                 memset(&req_u, 0, sizeof(req_u));
2890                 packet_set_ring(sk, &req_u, 1, 1);
2891         }
2892
2893         fanout_release(sk);
2894
2895         synchronize_net();
2896         /*
2897          *      Now the socket is dead. No more input will appear.
2898          */
2899         sock_orphan(sk);
2900         sock->sk = NULL;
2901
2902         /* Purge queues */
2903
2904         skb_queue_purge(&sk->sk_receive_queue);
2905         packet_free_pending(po);
2906         sk_refcnt_debug_release(sk);
2907
2908         sock_put(sk);
2909         return 0;
2910 }
2911
2912 /*
2913  *      Attach a packet hook.
2914  */
2915
2916 static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
2917                           __be16 proto)
2918 {
2919         struct packet_sock *po = pkt_sk(sk);
2920         struct net_device *dev_curr;
2921         __be16 proto_curr;
2922         bool need_rehook;
2923         struct net_device *dev = NULL;
2924         int ret = 0;
2925         bool unlisted = false;
2926
2927         if (po->fanout)
2928                 return -EINVAL;
2929
2930         lock_sock(sk);
2931         spin_lock(&po->bind_lock);
2932         rcu_read_lock();
2933
2934         if (name) {
2935                 dev = dev_get_by_name_rcu(sock_net(sk), name);
2936                 if (!dev) {
2937                         ret = -ENODEV;
2938                         goto out_unlock;
2939                 }
2940         } else if (ifindex) {
2941                 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
2942                 if (!dev) {
2943                         ret = -ENODEV;
2944                         goto out_unlock;
2945                 }
2946         }
2947
2948         if (dev)
2949                 dev_hold(dev);
2950
2951         proto_curr = po->prot_hook.type;
2952         dev_curr = po->prot_hook.dev;
2953
2954         need_rehook = proto_curr != proto || dev_curr != dev;
2955
2956         if (need_rehook) {
2957                 if (po->running) {
2958                         rcu_read_unlock();
2959                         __unregister_prot_hook(sk, true);
2960                         rcu_read_lock();
2961                         dev_curr = po->prot_hook.dev;
2962                         if (dev)
2963                                 unlisted = !dev_get_by_index_rcu(sock_net(sk),
2964                                                                  dev->ifindex);
2965                 }
2966
2967                 po->num = proto;
2968                 po->prot_hook.type = proto;
2969
2970                 if (unlikely(unlisted)) {
2971                         dev_put(dev);
2972                         po->prot_hook.dev = NULL;
2973                         po->ifindex = -1;
2974                         packet_cached_dev_reset(po);
2975                 } else {
2976                         po->prot_hook.dev = dev;
2977                         po->ifindex = dev ? dev->ifindex : 0;
2978                         packet_cached_dev_assign(po, dev);
2979                 }
2980         }
2981         if (dev_curr)
2982                 dev_put(dev_curr);
2983
2984         if (proto == 0 || !need_rehook)
2985                 goto out_unlock;
2986
2987         if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
2988                 register_prot_hook(sk);
2989         } else {
2990                 sk->sk_err = ENETDOWN;
2991                 if (!sock_flag(sk, SOCK_DEAD))
2992                         sk->sk_error_report(sk);
2993         }
2994
2995 out_unlock:
2996         rcu_read_unlock();
2997         spin_unlock(&po->bind_lock);
2998         release_sock(sk);
2999         return ret;
3000 }
3001
3002 /*
3003  *      Bind a packet socket to a device
3004  */
3005
3006 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3007                             int addr_len)
3008 {
3009         struct sock *sk = sock->sk;
3010         char name[15];
3011
3012         /*
3013          *      Check legality
3014          */
3015
3016         if (addr_len != sizeof(struct sockaddr))
3017                 return -EINVAL;
3018         strlcpy(name, uaddr->sa_data, sizeof(name));
3019
3020         return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3021 }
3022
3023 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3024 {
3025         struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3026         struct sock *sk = sock->sk;
3027
3028         /*
3029          *      Check legality
3030          */
3031
3032         if (addr_len < sizeof(struct sockaddr_ll))
3033                 return -EINVAL;
3034         if (sll->sll_family != AF_PACKET)
3035                 return -EINVAL;
3036
3037         return packet_do_bind(sk, NULL, sll->sll_ifindex,
3038                               sll->sll_protocol ? : pkt_sk(sk)->num);
3039 }
3040
3041 static struct proto packet_proto = {
3042         .name     = "PACKET",
3043         .owner    = THIS_MODULE,
3044         .obj_size = sizeof(struct packet_sock),
3045 };
3046
3047 /*
3048  *      Create a packet of type SOCK_PACKET.
3049  */
3050
3051 static int packet_create(struct net *net, struct socket *sock, int protocol,
3052                          int kern)
3053 {
3054         struct sock *sk;
3055         struct packet_sock *po;
3056         __be16 proto = (__force __be16)protocol; /* weird, but documented */
3057         int err;
3058
3059         if (!ns_capable(net->user_ns, CAP_NET_RAW))
3060                 return -EPERM;
3061         if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3062             sock->type != SOCK_PACKET)
3063                 return -ESOCKTNOSUPPORT;
3064
3065         sock->state = SS_UNCONNECTED;
3066
3067         err = -ENOBUFS;
3068         sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3069         if (sk == NULL)
3070                 goto out;
3071
3072         sock->ops = &packet_ops;
3073         if (sock->type == SOCK_PACKET)
3074                 sock->ops = &packet_ops_spkt;
3075
3076         sock_init_data(sock, sk);
3077
3078         po = pkt_sk(sk);
3079         sk->sk_family = PF_PACKET;
3080         po->num = proto;
3081         po->xmit = dev_queue_xmit;
3082
3083         err = packet_alloc_pending(po);
3084         if (err)
3085                 goto out2;
3086
3087         packet_cached_dev_reset(po);
3088
3089         sk->sk_destruct = packet_sock_destruct;
3090         sk_refcnt_debug_inc(sk);
3091
3092         /*
3093          *      Attach a protocol block
3094          */
3095
3096         spin_lock_init(&po->bind_lock);
3097         mutex_init(&po->pg_vec_lock);
3098         po->rollover = NULL;
3099         po->prot_hook.func = packet_rcv;
3100
3101         if (sock->type == SOCK_PACKET)
3102                 po->prot_hook.func = packet_rcv_spkt;
3103
3104         po->prot_hook.af_packet_priv = sk;
3105
3106         if (proto) {
3107                 po->prot_hook.type = proto;
3108                 register_prot_hook(sk);
3109         }
3110
3111         mutex_lock(&net->packet.sklist_lock);
3112         sk_add_node_rcu(sk, &net->packet.sklist);
3113         mutex_unlock(&net->packet.sklist_lock);
3114
3115         preempt_disable();
3116         sock_prot_inuse_add(net, &packet_proto, 1);
3117         preempt_enable();
3118
3119         return 0;
3120 out2:
3121         sk_free(sk);
3122 out:
3123         return err;
3124 }
3125
3126 /*
3127  *      Pull a packet from our receive queue and hand it to the user.
3128  *      If necessary we block.
3129  */
3130
3131 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3132                           int flags)
3133 {
3134         struct sock *sk = sock->sk;
3135         struct sk_buff *skb;
3136         int copied, err;
3137         int vnet_hdr_len = 0;
3138         unsigned int origlen = 0;
3139
3140         err = -EINVAL;
3141         if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3142                 goto out;
3143
3144 #if 0
3145         /* What error should we return now? EUNATTACH? */
3146         if (pkt_sk(sk)->ifindex < 0)
3147                 return -ENODEV;
3148 #endif
3149
3150         if (flags & MSG_ERRQUEUE) {
3151                 err = sock_recv_errqueue(sk, msg, len,
3152                                          SOL_PACKET, PACKET_TX_TIMESTAMP);
3153                 goto out;
3154         }
3155
3156         /*
3157          *      Call the generic datagram receiver. This handles all sorts
3158          *      of horrible races and re-entrancy so we can forget about it
3159          *      in the protocol layers.
3160          *
3161          *      Now it will return ENETDOWN, if device have just gone down,
3162          *      but then it will block.
3163          */
3164
3165         skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3166
3167         /*
3168          *      An error occurred so return it. Because skb_recv_datagram()
3169          *      handles the blocking we don't see and worry about blocking
3170          *      retries.
3171          */
3172
3173         if (skb == NULL)
3174                 goto out;
3175
3176         if (pkt_sk(sk)->pressure)
3177                 packet_rcv_has_room(pkt_sk(sk), NULL);
3178
3179         if (pkt_sk(sk)->has_vnet_hdr) {
3180                 struct virtio_net_hdr vnet_hdr = { 0 };
3181
3182                 err = -EINVAL;
3183                 vnet_hdr_len = sizeof(vnet_hdr);
3184                 if (len < vnet_hdr_len)
3185                         goto out_free;
3186
3187                 len -= vnet_hdr_len;
3188
3189                 if (skb_is_gso(skb)) {
3190                         struct skb_shared_info *sinfo = skb_shinfo(skb);
3191
3192                         /* This is a hint as to how much should be linear. */
3193                         vnet_hdr.hdr_len =
3194                                 __cpu_to_virtio16(vio_le(), skb_headlen(skb));
3195                         vnet_hdr.gso_size =
3196                                 __cpu_to_virtio16(vio_le(), sinfo->gso_size);
3197                         if (sinfo->gso_type & SKB_GSO_TCPV4)
3198                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
3199                         else if (sinfo->gso_type & SKB_GSO_TCPV6)
3200                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
3201                         else if (sinfo->gso_type & SKB_GSO_UDP)
3202                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
3203                         else if (sinfo->gso_type & SKB_GSO_FCOE)
3204                                 goto out_free;
3205                         else
3206                                 BUG();
3207                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
3208                                 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
3209                 } else
3210                         vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
3211
3212                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
3213                         vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
3214                         vnet_hdr.csum_start = __cpu_to_virtio16(vio_le(),
3215                                           skb_checksum_start_offset(skb));
3216                         vnet_hdr.csum_offset = __cpu_to_virtio16(vio_le(),
3217                                                          skb->csum_offset);
3218                 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
3219                         vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
3220                 } /* else everything is zero */
3221
3222                 err = memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_len);
3223                 if (err < 0)
3224                         goto out_free;
3225         }
3226
3227         /* You lose any data beyond the buffer you gave. If it worries
3228          * a user program they can ask the device for its MTU
3229          * anyway.
3230          */
3231         copied = skb->len;
3232         if (copied > len) {
3233                 copied = len;
3234                 msg->msg_flags |= MSG_TRUNC;
3235         }
3236
3237         err = skb_copy_datagram_msg(skb, 0, msg, copied);
3238         if (err)
3239                 goto out_free;
3240
3241         if (sock->type != SOCK_PACKET) {
3242                 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3243
3244                 /* Original length was stored in sockaddr_ll fields */
3245                 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3246                 sll->sll_family = AF_PACKET;
3247                 sll->sll_protocol = skb->protocol;
3248         }
3249
3250         sock_recv_ts_and_drops(msg, sk, skb);
3251
3252         if (msg->msg_name) {
3253                 /* If the address length field is there to be filled
3254                  * in, we fill it in now.
3255                  */
3256                 if (sock->type == SOCK_PACKET) {
3257                         __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3258                         msg->msg_namelen = sizeof(struct sockaddr_pkt);
3259                 } else {
3260                         struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3261
3262                         msg->msg_namelen = sll->sll_halen +
3263                                 offsetof(struct sockaddr_ll, sll_addr);
3264                 }
3265                 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
3266                        msg->msg_namelen);
3267         }
3268
3269         if (pkt_sk(sk)->auxdata) {
3270                 struct tpacket_auxdata aux;
3271
3272                 aux.tp_status = TP_STATUS_USER;
3273                 if (skb->ip_summed == CHECKSUM_PARTIAL)
3274                         aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3275                 else if (skb->pkt_type != PACKET_OUTGOING &&
3276                          (skb->ip_summed == CHECKSUM_COMPLETE ||
3277                           skb_csum_unnecessary(skb)))
3278                         aux.tp_status |= TP_STATUS_CSUM_VALID;
3279
3280                 aux.tp_len = origlen;
3281                 aux.tp_snaplen = skb->len;
3282                 aux.tp_mac = 0;
3283                 aux.tp_net = skb_network_offset(skb);
3284                 if (skb_vlan_tag_present(skb)) {
3285                         aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3286                         aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3287                         aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3288                 } else {
3289                         aux.tp_vlan_tci = 0;
3290                         aux.tp_vlan_tpid = 0;
3291                 }
3292                 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3293         }
3294
3295         /*
3296          *      Free or return the buffer as appropriate. Again this
3297          *      hides all the races and re-entrancy issues from us.
3298          */
3299         err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3300
3301 out_free:
3302         skb_free_datagram(sk, skb);
3303 out:
3304         return err;
3305 }
3306
3307 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3308                                int *uaddr_len, int peer)
3309 {
3310         struct net_device *dev;
3311         struct sock *sk = sock->sk;
3312
3313         if (peer)
3314                 return -EOPNOTSUPP;
3315
3316         uaddr->sa_family = AF_PACKET;
3317         memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3318         rcu_read_lock();
3319         dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
3320         if (dev)
3321                 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3322         rcu_read_unlock();
3323         *uaddr_len = sizeof(*uaddr);
3324
3325         return 0;
3326 }
3327
3328 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3329                           int *uaddr_len, int peer)
3330 {
3331         struct net_device *dev;
3332         struct sock *sk = sock->sk;
3333         struct packet_sock *po = pkt_sk(sk);
3334         DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3335
3336         if (peer)
3337                 return -EOPNOTSUPP;
3338
3339         sll->sll_family = AF_PACKET;
3340         sll->sll_ifindex = po->ifindex;
3341         sll->sll_protocol = po->num;
3342         sll->sll_pkttype = 0;
3343         rcu_read_lock();
3344         dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
3345         if (dev) {
3346                 sll->sll_hatype = dev->type;
3347                 sll->sll_halen = dev->addr_len;
3348                 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3349         } else {
3350                 sll->sll_hatype = 0;    /* Bad: we have no ARPHRD_UNSPEC */
3351                 sll->sll_halen = 0;
3352         }
3353         rcu_read_unlock();
3354         *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3355
3356         return 0;
3357 }
3358
3359 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3360                          int what)
3361 {
3362         switch (i->type) {
3363         case PACKET_MR_MULTICAST:
3364                 if (i->alen != dev->addr_len)
3365                         return -EINVAL;
3366                 if (what > 0)
3367                         return dev_mc_add(dev, i->addr);
3368                 else
3369                         return dev_mc_del(dev, i->addr);
3370                 break;
3371         case PACKET_MR_PROMISC:
3372                 return dev_set_promiscuity(dev, what);
3373         case PACKET_MR_ALLMULTI:
3374                 return dev_set_allmulti(dev, what);
3375         case PACKET_MR_UNICAST:
3376                 if (i->alen != dev->addr_len)
3377                         return -EINVAL;
3378                 if (what > 0)
3379                         return dev_uc_add(dev, i->addr);
3380                 else
3381                         return dev_uc_del(dev, i->addr);
3382                 break;
3383         default:
3384                 break;
3385         }
3386         return 0;
3387 }
3388
3389 static void packet_dev_mclist_delete(struct net_device *dev,
3390                                      struct packet_mclist **mlp)
3391 {
3392         struct packet_mclist *ml;
3393
3394         while ((ml = *mlp) != NULL) {
3395                 if (ml->ifindex == dev->ifindex) {
3396                         packet_dev_mc(dev, ml, -1);
3397                         *mlp = ml->next;
3398                         kfree(ml);
3399                 } else
3400                         mlp = &ml->next;
3401         }
3402 }
3403
3404 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3405 {
3406         struct packet_sock *po = pkt_sk(sk);
3407         struct packet_mclist *ml, *i;
3408         struct net_device *dev;
3409         int err;
3410
3411         rtnl_lock();
3412
3413         err = -ENODEV;
3414         dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3415         if (!dev)
3416                 goto done;
3417
3418         err = -EINVAL;
3419         if (mreq->mr_alen > dev->addr_len)
3420                 goto done;
3421
3422         err = -ENOBUFS;
3423         i = kmalloc(sizeof(*i), GFP_KERNEL);
3424         if (i == NULL)
3425                 goto done;
3426
3427         err = 0;
3428         for (ml = po->mclist; ml; ml = ml->next) {
3429                 if (ml->ifindex == mreq->mr_ifindex &&
3430                     ml->type == mreq->mr_type &&
3431                     ml->alen == mreq->mr_alen &&
3432                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3433                         ml->count++;
3434                         /* Free the new element ... */
3435                         kfree(i);
3436                         goto done;
3437                 }
3438         }
3439
3440         i->type = mreq->mr_type;
3441         i->ifindex = mreq->mr_ifindex;
3442         i->alen = mreq->mr_alen;
3443         memcpy(i->addr, mreq->mr_address, i->alen);
3444         memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3445         i->count = 1;
3446         i->next = po->mclist;
3447         po->mclist = i;
3448         err = packet_dev_mc(dev, i, 1);
3449         if (err) {
3450                 po->mclist = i->next;
3451                 kfree(i);
3452         }
3453
3454 done:
3455         rtnl_unlock();
3456         return err;
3457 }
3458
3459 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3460 {
3461         struct packet_mclist *ml, **mlp;
3462
3463         rtnl_lock();
3464
3465         for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3466                 if (ml->ifindex == mreq->mr_ifindex &&
3467                     ml->type == mreq->mr_type &&
3468                     ml->alen == mreq->mr_alen &&
3469                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3470                         if (--ml->count == 0) {
3471                                 struct net_device *dev;
3472                                 *mlp = ml->next;
3473                                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3474                                 if (dev)
3475                                         packet_dev_mc(dev, ml, -1);
3476                                 kfree(ml);
3477                         }
3478                         break;
3479                 }
3480         }
3481         rtnl_unlock();
3482         return 0;
3483 }
3484
3485 static void packet_flush_mclist(struct sock *sk)
3486 {
3487         struct packet_sock *po = pkt_sk(sk);
3488         struct packet_mclist *ml;
3489
3490         if (!po->mclist)
3491                 return;
3492
3493         rtnl_lock();
3494         while ((ml = po->mclist) != NULL) {
3495                 struct net_device *dev;
3496
3497                 po->mclist = ml->next;
3498                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3499                 if (dev != NULL)
3500                         packet_dev_mc(dev, ml, -1);
3501                 kfree(ml);
3502         }
3503         rtnl_unlock();
3504 }
3505
3506 static int
3507 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3508 {
3509         struct sock *sk = sock->sk;
3510         struct packet_sock *po = pkt_sk(sk);
3511         int ret;
3512
3513         if (level != SOL_PACKET)
3514                 return -ENOPROTOOPT;
3515
3516         switch (optname) {
3517         case PACKET_ADD_MEMBERSHIP:
3518         case PACKET_DROP_MEMBERSHIP:
3519         {
3520                 struct packet_mreq_max mreq;
3521                 int len = optlen;
3522                 memset(&mreq, 0, sizeof(mreq));
3523                 if (len < sizeof(struct packet_mreq))
3524                         return -EINVAL;
3525                 if (len > sizeof(mreq))
3526                         len = sizeof(mreq);
3527                 if (copy_from_user(&mreq, optval, len))
3528                         return -EFAULT;
3529                 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3530                         return -EINVAL;
3531                 if (optname == PACKET_ADD_MEMBERSHIP)
3532                         ret = packet_mc_add(sk, &mreq);
3533                 else
3534                         ret = packet_mc_drop(sk, &mreq);
3535                 return ret;
3536         }
3537
3538         case PACKET_RX_RING:
3539         case PACKET_TX_RING:
3540         {
3541                 union tpacket_req_u req_u;
3542                 int len;
3543
3544                 switch (po->tp_version) {
3545                 case TPACKET_V1:
3546                 case TPACKET_V2:
3547                         len = sizeof(req_u.req);
3548                         break;
3549                 case TPACKET_V3:
3550                 default:
3551                         len = sizeof(req_u.req3);
3552                         break;
3553                 }
3554                 if (optlen < len)
3555                         return -EINVAL;
3556                 if (pkt_sk(sk)->has_vnet_hdr)
3557                         return -EINVAL;
3558                 if (copy_from_user(&req_u.req, optval, len))
3559                         return -EFAULT;
3560                 return packet_set_ring(sk, &req_u, 0,
3561                         optname == PACKET_TX_RING);
3562         }
3563         case PACKET_COPY_THRESH:
3564         {
3565                 int val;
3566
3567                 if (optlen != sizeof(val))
3568                         return -EINVAL;
3569                 if (copy_from_user(&val, optval, sizeof(val)))
3570                         return -EFAULT;
3571
3572                 pkt_sk(sk)->copy_thresh = val;
3573                 return 0;
3574         }
3575         case PACKET_VERSION:
3576         {
3577                 int val;
3578
3579                 if (optlen != sizeof(val))
3580                         return -EINVAL;
3581                 if (copy_from_user(&val, optval, sizeof(val)))
3582                         return -EFAULT;
3583                 switch (val) {
3584                 case TPACKET_V1:
3585                 case TPACKET_V2:
3586                 case TPACKET_V3:
3587                         break;
3588                 default:
3589                         return -EINVAL;
3590                 }
3591                 lock_sock(sk);
3592                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3593                         ret = -EBUSY;
3594                 } else {
3595                         po->tp_version = val;
3596                         ret = 0;
3597                 }
3598                 release_sock(sk);
3599                 return ret;
3600         }
3601         case PACKET_RESERVE:
3602         {
3603                 unsigned int val;
3604
3605                 if (optlen != sizeof(val))
3606                         return -EINVAL;
3607                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3608                         return -EBUSY;
3609                 if (copy_from_user(&val, optval, sizeof(val)))
3610                         return -EFAULT;
3611                 po->tp_reserve = val;
3612                 return 0;
3613         }
3614         case PACKET_LOSS:
3615         {
3616                 unsigned int val;
3617
3618                 if (optlen != sizeof(val))
3619                         return -EINVAL;
3620                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3621                         return -EBUSY;
3622                 if (copy_from_user(&val, optval, sizeof(val)))
3623                         return -EFAULT;
3624                 po->tp_loss = !!val;
3625                 return 0;
3626         }
3627         case PACKET_AUXDATA:
3628         {
3629                 int val;
3630
3631                 if (optlen < sizeof(val))
3632                         return -EINVAL;
3633                 if (copy_from_user(&val, optval, sizeof(val)))
3634                         return -EFAULT;
3635
3636                 po->auxdata = !!val;
3637                 return 0;
3638         }
3639         case PACKET_ORIGDEV:
3640         {
3641                 int val;
3642
3643                 if (optlen < sizeof(val))
3644                         return -EINVAL;
3645                 if (copy_from_user(&val, optval, sizeof(val)))
3646                         return -EFAULT;
3647
3648                 po->origdev = !!val;
3649                 return 0;
3650         }
3651         case PACKET_VNET_HDR:
3652         {
3653                 int val;
3654
3655                 if (sock->type != SOCK_RAW)
3656                         return -EINVAL;
3657                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3658                         return -EBUSY;
3659                 if (optlen < sizeof(val))
3660                         return -EINVAL;
3661                 if (copy_from_user(&val, optval, sizeof(val)))
3662                         return -EFAULT;
3663
3664                 po->has_vnet_hdr = !!val;
3665                 return 0;
3666         }
3667         case PACKET_TIMESTAMP:
3668         {
3669                 int val;
3670
3671                 if (optlen != sizeof(val))
3672                         return -EINVAL;
3673                 if (copy_from_user(&val, optval, sizeof(val)))
3674                         return -EFAULT;
3675
3676                 po->tp_tstamp = val;
3677                 return 0;
3678         }
3679         case PACKET_FANOUT:
3680         {
3681                 int val;
3682
3683                 if (optlen != sizeof(val))
3684                         return -EINVAL;
3685                 if (copy_from_user(&val, optval, sizeof(val)))
3686                         return -EFAULT;
3687
3688                 return fanout_add(sk, val & 0xffff, val >> 16);
3689         }
3690         case PACKET_FANOUT_DATA:
3691         {
3692                 if (!po->fanout)
3693                         return -EINVAL;
3694
3695                 return fanout_set_data(po, optval, optlen);
3696         }
3697         case PACKET_TX_HAS_OFF:
3698         {
3699                 unsigned int val;
3700
3701                 if (optlen != sizeof(val))
3702                         return -EINVAL;
3703                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3704                         return -EBUSY;
3705                 if (copy_from_user(&val, optval, sizeof(val)))
3706                         return -EFAULT;
3707                 po->tp_tx_has_off = !!val;
3708                 return 0;
3709         }
3710         case PACKET_QDISC_BYPASS:
3711         {
3712                 int val;
3713
3714                 if (optlen != sizeof(val))
3715                         return -EINVAL;
3716                 if (copy_from_user(&val, optval, sizeof(val)))
3717                         return -EFAULT;
3718
3719                 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3720                 return 0;
3721         }
3722         default:
3723                 return -ENOPROTOOPT;
3724         }
3725 }
3726
3727 static int packet_getsockopt(struct socket *sock, int level, int optname,
3728                              char __user *optval, int __user *optlen)
3729 {
3730         int len;
3731         int val, lv = sizeof(val);
3732         struct sock *sk = sock->sk;
3733         struct packet_sock *po = pkt_sk(sk);
3734         void *data = &val;
3735         union tpacket_stats_u st;
3736         struct tpacket_rollover_stats rstats;
3737
3738         if (level != SOL_PACKET)
3739                 return -ENOPROTOOPT;
3740
3741         if (get_user(len, optlen))
3742                 return -EFAULT;
3743
3744         if (len < 0)
3745                 return -EINVAL;
3746
3747         switch (optname) {
3748         case PACKET_STATISTICS:
3749                 spin_lock_bh(&sk->sk_receive_queue.lock);
3750                 memcpy(&st, &po->stats, sizeof(st));
3751                 memset(&po->stats, 0, sizeof(po->stats));
3752                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3753
3754                 if (po->tp_version == TPACKET_V3) {
3755                         lv = sizeof(struct tpacket_stats_v3);
3756                         st.stats3.tp_packets += st.stats3.tp_drops;
3757                         data = &st.stats3;
3758                 } else {
3759                         lv = sizeof(struct tpacket_stats);
3760                         st.stats1.tp_packets += st.stats1.tp_drops;
3761                         data = &st.stats1;
3762                 }
3763
3764                 break;
3765         case PACKET_AUXDATA:
3766                 val = po->auxdata;
3767                 break;
3768         case PACKET_ORIGDEV:
3769                 val = po->origdev;
3770                 break;
3771         case PACKET_VNET_HDR:
3772                 val = po->has_vnet_hdr;
3773                 break;
3774         case PACKET_VERSION:
3775                 val = po->tp_version;
3776                 break;
3777         case PACKET_HDRLEN:
3778                 if (len > sizeof(int))
3779                         len = sizeof(int);
3780                 if (copy_from_user(&val, optval, len))
3781                         return -EFAULT;
3782                 switch (val) {
3783                 case TPACKET_V1:
3784                         val = sizeof(struct tpacket_hdr);
3785                         break;
3786                 case TPACKET_V2:
3787                         val = sizeof(struct tpacket2_hdr);
3788                         break;
3789                 case TPACKET_V3:
3790                         val = sizeof(struct tpacket3_hdr);
3791                         break;
3792                 default:
3793                         return -EINVAL;
3794                 }
3795                 break;
3796         case PACKET_RESERVE:
3797                 val = po->tp_reserve;
3798                 break;
3799         case PACKET_LOSS:
3800                 val = po->tp_loss;
3801                 break;
3802         case PACKET_TIMESTAMP:
3803                 val = po->tp_tstamp;
3804                 break;
3805         case PACKET_FANOUT:
3806                 val = (po->fanout ?
3807                        ((u32)po->fanout->id |
3808                         ((u32)po->fanout->type << 16) |
3809                         ((u32)po->fanout->flags << 24)) :
3810                        0);
3811                 break;
3812         case PACKET_ROLLOVER_STATS:
3813                 if (!po->rollover)
3814                         return -EINVAL;
3815                 rstats.tp_all = atomic_long_read(&po->rollover->num);
3816                 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
3817                 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
3818                 data = &rstats;
3819                 lv = sizeof(rstats);
3820                 break;
3821         case PACKET_TX_HAS_OFF:
3822                 val = po->tp_tx_has_off;
3823                 break;
3824         case PACKET_QDISC_BYPASS:
3825                 val = packet_use_direct_xmit(po);
3826                 break;
3827         default:
3828                 return -ENOPROTOOPT;
3829         }
3830
3831         if (len > lv)
3832                 len = lv;
3833         if (put_user(len, optlen))
3834                 return -EFAULT;
3835         if (copy_to_user(optval, data, len))
3836                 return -EFAULT;
3837         return 0;
3838 }
3839
3840
3841 static int packet_notifier(struct notifier_block *this,
3842                            unsigned long msg, void *ptr)
3843 {
3844         struct sock *sk;
3845         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3846         struct net *net = dev_net(dev);
3847
3848         rcu_read_lock();
3849         sk_for_each_rcu(sk, &net->packet.sklist) {
3850                 struct packet_sock *po = pkt_sk(sk);
3851
3852                 switch (msg) {
3853                 case NETDEV_UNREGISTER:
3854                         if (po->mclist)
3855                                 packet_dev_mclist_delete(dev, &po->mclist);
3856                         /* fallthrough */
3857
3858                 case NETDEV_DOWN:
3859                         if (dev->ifindex == po->ifindex) {
3860                                 spin_lock(&po->bind_lock);
3861                                 if (po->running) {
3862                                         __unregister_prot_hook(sk, false);
3863                                         sk->sk_err = ENETDOWN;
3864                                         if (!sock_flag(sk, SOCK_DEAD))
3865                                                 sk->sk_error_report(sk);
3866                                 }
3867                                 if (msg == NETDEV_UNREGISTER) {
3868                                         packet_cached_dev_reset(po);
3869                                         fanout_release(sk);
3870                                         po->ifindex = -1;
3871                                         if (po->prot_hook.dev)
3872                                                 dev_put(po->prot_hook.dev);
3873                                         po->prot_hook.dev = NULL;
3874                                 }
3875                                 spin_unlock(&po->bind_lock);
3876                         }
3877                         break;
3878                 case NETDEV_UP:
3879                         if (dev->ifindex == po->ifindex) {
3880                                 spin_lock(&po->bind_lock);
3881                                 if (po->num)
3882                                         register_prot_hook(sk);
3883                                 spin_unlock(&po->bind_lock);
3884                         }
3885                         break;
3886                 }
3887         }
3888         rcu_read_unlock();
3889         return NOTIFY_DONE;
3890 }
3891
3892
3893 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3894                         unsigned long arg)
3895 {
3896         struct sock *sk = sock->sk;
3897
3898         switch (cmd) {
3899         case SIOCOUTQ:
3900         {
3901                 int amount = sk_wmem_alloc_get(sk);
3902
3903                 return put_user(amount, (int __user *)arg);
3904         }
3905         case SIOCINQ:
3906         {
3907                 struct sk_buff *skb;
3908                 int amount = 0;
3909
3910                 spin_lock_bh(&sk->sk_receive_queue.lock);
3911                 skb = skb_peek(&sk->sk_receive_queue);
3912                 if (skb)
3913                         amount = skb->len;
3914                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3915                 return put_user(amount, (int __user *)arg);
3916         }
3917         case SIOCGSTAMP:
3918                 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3919         case SIOCGSTAMPNS:
3920                 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3921
3922 #ifdef CONFIG_INET
3923         case SIOCADDRT:
3924         case SIOCDELRT:
3925         case SIOCDARP:
3926         case SIOCGARP:
3927         case SIOCSARP:
3928         case SIOCGIFADDR:
3929         case SIOCSIFADDR:
3930         case SIOCGIFBRDADDR:
3931         case SIOCSIFBRDADDR:
3932         case SIOCGIFNETMASK:
3933         case SIOCSIFNETMASK:
3934         case SIOCGIFDSTADDR:
3935         case SIOCSIFDSTADDR:
3936         case SIOCSIFFLAGS:
3937                 return inet_dgram_ops.ioctl(sock, cmd, arg);
3938 #endif
3939
3940         default:
3941                 return -ENOIOCTLCMD;
3942         }
3943         return 0;
3944 }
3945
3946 static unsigned int packet_poll(struct file *file, struct socket *sock,
3947                                 poll_table *wait)
3948 {
3949         struct sock *sk = sock->sk;
3950         struct packet_sock *po = pkt_sk(sk);
3951         unsigned int mask = datagram_poll(file, sock, wait);
3952
3953         spin_lock_bh(&sk->sk_receive_queue.lock);
3954         if (po->rx_ring.pg_vec) {
3955                 if (!packet_previous_rx_frame(po, &po->rx_ring,
3956                         TP_STATUS_KERNEL))
3957                         mask |= POLLIN | POLLRDNORM;
3958         }
3959         if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
3960                 po->pressure = 0;
3961         spin_unlock_bh(&sk->sk_receive_queue.lock);
3962         spin_lock_bh(&sk->sk_write_queue.lock);
3963         if (po->tx_ring.pg_vec) {
3964                 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3965                         mask |= POLLOUT | POLLWRNORM;
3966         }
3967         spin_unlock_bh(&sk->sk_write_queue.lock);
3968         return mask;
3969 }
3970
3971
3972 /* Dirty? Well, I still did not learn better way to account
3973  * for user mmaps.
3974  */
3975
3976 static void packet_mm_open(struct vm_area_struct *vma)
3977 {
3978         struct file *file = vma->vm_file;
3979         struct socket *sock = file->private_data;
3980         struct sock *sk = sock->sk;
3981
3982         if (sk)
3983                 atomic_inc(&pkt_sk(sk)->mapped);
3984 }
3985
3986 static void packet_mm_close(struct vm_area_struct *vma)
3987 {
3988         struct file *file = vma->vm_file;
3989         struct socket *sock = file->private_data;
3990         struct sock *sk = sock->sk;
3991
3992         if (sk)
3993                 atomic_dec(&pkt_sk(sk)->mapped);
3994 }
3995
3996 static const struct vm_operations_struct packet_mmap_ops = {
3997         .open   =       packet_mm_open,
3998         .close  =       packet_mm_close,
3999 };
4000
4001 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4002                         unsigned int len)
4003 {
4004         int i;
4005
4006         for (i = 0; i < len; i++) {
4007                 if (likely(pg_vec[i].buffer)) {
4008                         if (is_vmalloc_addr(pg_vec[i].buffer))
4009                                 vfree(pg_vec[i].buffer);
4010                         else
4011                                 free_pages((unsigned long)pg_vec[i].buffer,
4012                                            order);
4013                         pg_vec[i].buffer = NULL;
4014                 }
4015         }
4016         kfree(pg_vec);
4017 }
4018
4019 static char *alloc_one_pg_vec_page(unsigned long order)
4020 {
4021         char *buffer;
4022         gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4023                           __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4024
4025         buffer = (char *) __get_free_pages(gfp_flags, order);
4026         if (buffer)
4027                 return buffer;
4028
4029         /* __get_free_pages failed, fall back to vmalloc */
4030         buffer = vzalloc((1 << order) * PAGE_SIZE);
4031         if (buffer)
4032                 return buffer;
4033
4034         /* vmalloc failed, lets dig into swap here */
4035         gfp_flags &= ~__GFP_NORETRY;
4036         buffer = (char *) __get_free_pages(gfp_flags, order);
4037         if (buffer)
4038                 return buffer;
4039
4040         /* complete and utter failure */
4041         return NULL;
4042 }
4043
4044 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4045 {
4046         unsigned int block_nr = req->tp_block_nr;
4047         struct pgv *pg_vec;
4048         int i;
4049
4050         pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
4051         if (unlikely(!pg_vec))
4052                 goto out;
4053
4054         for (i = 0; i < block_nr; i++) {
4055                 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4056                 if (unlikely(!pg_vec[i].buffer))
4057                         goto out_free_pgvec;
4058         }
4059
4060 out:
4061         return pg_vec;
4062
4063 out_free_pgvec:
4064         free_pg_vec(pg_vec, order, block_nr);
4065         pg_vec = NULL;
4066         goto out;
4067 }
4068
4069 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4070                 int closing, int tx_ring)
4071 {
4072         struct pgv *pg_vec = NULL;
4073         struct packet_sock *po = pkt_sk(sk);
4074         int was_running, order = 0;
4075         struct packet_ring_buffer *rb;
4076         struct sk_buff_head *rb_queue;
4077         __be16 num;
4078         int err = -EINVAL;
4079         /* Added to avoid minimal code churn */
4080         struct tpacket_req *req = &req_u->req;
4081
4082         lock_sock(sk);
4083         /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
4084         if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
4085                 WARN(1, "Tx-ring is not supported.\n");
4086                 goto out;
4087         }
4088
4089         rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4090         rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4091
4092         err = -EBUSY;
4093         if (!closing) {
4094                 if (atomic_read(&po->mapped))
4095                         goto out;
4096                 if (packet_read_pending(rb))
4097                         goto out;
4098         }
4099
4100         if (req->tp_block_nr) {
4101                 /* Sanity tests and some calculations */
4102                 err = -EBUSY;
4103                 if (unlikely(rb->pg_vec))
4104                         goto out;
4105
4106                 switch (po->tp_version) {
4107                 case TPACKET_V1:
4108                         po->tp_hdrlen = TPACKET_HDRLEN;
4109                         break;
4110                 case TPACKET_V2:
4111                         po->tp_hdrlen = TPACKET2_HDRLEN;
4112                         break;
4113                 case TPACKET_V3:
4114                         po->tp_hdrlen = TPACKET3_HDRLEN;
4115                         break;
4116                 }
4117
4118                 err = -EINVAL;
4119                 if (unlikely((int)req->tp_block_size <= 0))
4120                         goto out;
4121                 if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4122                         goto out;
4123                 if (po->tp_version >= TPACKET_V3 &&
4124                     (int)(req->tp_block_size -
4125                           BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0)
4126                         goto out;
4127                 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
4128                                         po->tp_reserve))
4129                         goto out;
4130                 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4131                         goto out;
4132
4133                 rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4134                 if (unlikely(rb->frames_per_block == 0))
4135                         goto out;
4136                 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4137                                         req->tp_frame_nr))
4138                         goto out;
4139
4140                 err = -ENOMEM;
4141                 order = get_order(req->tp_block_size);
4142                 pg_vec = alloc_pg_vec(req, order);
4143                 if (unlikely(!pg_vec))
4144                         goto out;
4145                 switch (po->tp_version) {
4146                 case TPACKET_V3:
4147                 /* Transmit path is not supported. We checked
4148                  * it above but just being paranoid
4149                  */
4150                         if (!tx_ring)
4151                                 init_prb_bdqc(po, rb, pg_vec, req_u);
4152                         break;
4153                 default:
4154                         break;
4155                 }
4156         }
4157         /* Done */
4158         else {
4159                 err = -EINVAL;
4160                 if (unlikely(req->tp_frame_nr))
4161                         goto out;
4162         }
4163
4164
4165         /* Detach socket from network */
4166         spin_lock(&po->bind_lock);
4167         was_running = po->running;
4168         num = po->num;
4169         if (was_running) {
4170                 po->num = 0;
4171                 __unregister_prot_hook(sk, false);
4172         }
4173         spin_unlock(&po->bind_lock);
4174
4175         synchronize_net();
4176
4177         err = -EBUSY;
4178         mutex_lock(&po->pg_vec_lock);
4179         if (closing || atomic_read(&po->mapped) == 0) {
4180                 err = 0;
4181                 spin_lock_bh(&rb_queue->lock);
4182                 swap(rb->pg_vec, pg_vec);
4183                 rb->frame_max = (req->tp_frame_nr - 1);
4184                 rb->head = 0;
4185                 rb->frame_size = req->tp_frame_size;
4186                 spin_unlock_bh(&rb_queue->lock);
4187
4188                 swap(rb->pg_vec_order, order);
4189                 swap(rb->pg_vec_len, req->tp_block_nr);
4190
4191                 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4192                 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4193                                                 tpacket_rcv : packet_rcv;
4194                 skb_queue_purge(rb_queue);
4195                 if (atomic_read(&po->mapped))
4196                         pr_err("packet_mmap: vma is busy: %d\n",
4197                                atomic_read(&po->mapped));
4198         }
4199         mutex_unlock(&po->pg_vec_lock);
4200
4201         spin_lock(&po->bind_lock);
4202         if (was_running) {
4203                 po->num = num;
4204                 register_prot_hook(sk);
4205         }
4206         spin_unlock(&po->bind_lock);
4207         if (closing && (po->tp_version > TPACKET_V2)) {
4208                 /* Because we don't support block-based V3 on tx-ring */
4209                 if (!tx_ring)
4210                         prb_shutdown_retire_blk_timer(po, rb_queue);
4211         }
4212
4213         if (pg_vec)
4214                 free_pg_vec(pg_vec, order, req->tp_block_nr);
4215 out:
4216         release_sock(sk);
4217         return err;
4218 }
4219
4220 static int packet_mmap(struct file *file, struct socket *sock,
4221                 struct vm_area_struct *vma)
4222 {
4223         struct sock *sk = sock->sk;
4224         struct packet_sock *po = pkt_sk(sk);
4225         unsigned long size, expected_size;
4226         struct packet_ring_buffer *rb;
4227         unsigned long start;
4228         int err = -EINVAL;
4229         int i;
4230
4231         if (vma->vm_pgoff)
4232                 return -EINVAL;
4233
4234         mutex_lock(&po->pg_vec_lock);
4235
4236         expected_size = 0;
4237         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4238                 if (rb->pg_vec) {
4239                         expected_size += rb->pg_vec_len
4240                                                 * rb->pg_vec_pages
4241                                                 * PAGE_SIZE;
4242                 }
4243         }
4244
4245         if (expected_size == 0)
4246                 goto out;
4247
4248         size = vma->vm_end - vma->vm_start;
4249         if (size != expected_size)
4250                 goto out;
4251
4252         start = vma->vm_start;
4253         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4254                 if (rb->pg_vec == NULL)
4255                         continue;
4256
4257                 for (i = 0; i < rb->pg_vec_len; i++) {
4258                         struct page *page;
4259                         void *kaddr = rb->pg_vec[i].buffer;
4260                         int pg_num;
4261
4262                         for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4263                                 page = pgv_to_page(kaddr);
4264                                 err = vm_insert_page(vma, start, page);
4265                                 if (unlikely(err))
4266                                         goto out;
4267                                 start += PAGE_SIZE;
4268                                 kaddr += PAGE_SIZE;
4269                         }
4270                 }
4271         }
4272
4273         atomic_inc(&po->mapped);
4274         vma->vm_ops = &packet_mmap_ops;
4275         err = 0;
4276
4277 out:
4278         mutex_unlock(&po->pg_vec_lock);
4279         return err;
4280 }
4281
4282 static const struct proto_ops packet_ops_spkt = {
4283         .family =       PF_PACKET,
4284         .owner =        THIS_MODULE,
4285         .release =      packet_release,
4286         .bind =         packet_bind_spkt,
4287         .connect =      sock_no_connect,
4288         .socketpair =   sock_no_socketpair,
4289         .accept =       sock_no_accept,
4290         .getname =      packet_getname_spkt,
4291         .poll =         datagram_poll,
4292         .ioctl =        packet_ioctl,
4293         .listen =       sock_no_listen,
4294         .shutdown =     sock_no_shutdown,
4295         .setsockopt =   sock_no_setsockopt,
4296         .getsockopt =   sock_no_getsockopt,
4297         .sendmsg =      packet_sendmsg_spkt,
4298         .recvmsg =      packet_recvmsg,
4299         .mmap =         sock_no_mmap,
4300         .sendpage =     sock_no_sendpage,
4301 };
4302
4303 static const struct proto_ops packet_ops = {
4304         .family =       PF_PACKET,
4305         .owner =        THIS_MODULE,
4306         .release =      packet_release,
4307         .bind =         packet_bind,
4308         .connect =      sock_no_connect,
4309         .socketpair =   sock_no_socketpair,
4310         .accept =       sock_no_accept,
4311         .getname =      packet_getname,
4312         .poll =         packet_poll,
4313         .ioctl =        packet_ioctl,
4314         .listen =       sock_no_listen,
4315         .shutdown =     sock_no_shutdown,
4316         .setsockopt =   packet_setsockopt,
4317         .getsockopt =   packet_getsockopt,
4318         .sendmsg =      packet_sendmsg,
4319         .recvmsg =      packet_recvmsg,
4320         .mmap =         packet_mmap,
4321         .sendpage =     sock_no_sendpage,
4322 };
4323
4324 static const struct net_proto_family packet_family_ops = {
4325         .family =       PF_PACKET,
4326         .create =       packet_create,
4327         .owner  =       THIS_MODULE,
4328 };
4329
4330 static struct notifier_block packet_netdev_notifier = {
4331         .notifier_call =        packet_notifier,
4332 };
4333
4334 #ifdef CONFIG_PROC_FS
4335
4336 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4337         __acquires(RCU)
4338 {
4339         struct net *net = seq_file_net(seq);
4340
4341         rcu_read_lock();
4342         return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4343 }
4344
4345 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4346 {
4347         struct net *net = seq_file_net(seq);
4348         return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4349 }
4350
4351 static void packet_seq_stop(struct seq_file *seq, void *v)
4352         __releases(RCU)
4353 {
4354         rcu_read_unlock();
4355 }
4356
4357 static int packet_seq_show(struct seq_file *seq, void *v)
4358 {
4359         if (v == SEQ_START_TOKEN)
4360                 seq_puts(seq, "sk       RefCnt Type Proto  Iface R Rmem   User   Inode\n");
4361         else {
4362                 struct sock *s = sk_entry(v);
4363                 const struct packet_sock *po = pkt_sk(s);
4364
4365                 seq_printf(seq,
4366                            "%pK %-6d %-4d %04x   %-5d %1d %-6u %-6u %-6lu\n",
4367                            s,
4368                            atomic_read(&s->sk_refcnt),
4369                            s->sk_type,
4370                            ntohs(po->num),
4371                            po->ifindex,
4372                            po->running,
4373                            atomic_read(&s->sk_rmem_alloc),
4374                            from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4375                            sock_i_ino(s));
4376         }
4377
4378         return 0;
4379 }
4380
4381 static const struct seq_operations packet_seq_ops = {
4382         .start  = packet_seq_start,
4383         .next   = packet_seq_next,
4384         .stop   = packet_seq_stop,
4385         .show   = packet_seq_show,
4386 };
4387
4388 static int packet_seq_open(struct inode *inode, struct file *file)
4389 {
4390         return seq_open_net(inode, file, &packet_seq_ops,
4391                             sizeof(struct seq_net_private));
4392 }
4393
4394 static const struct file_operations packet_seq_fops = {
4395         .owner          = THIS_MODULE,
4396         .open           = packet_seq_open,
4397         .read           = seq_read,
4398         .llseek         = seq_lseek,
4399         .release        = seq_release_net,
4400 };
4401
4402 #endif
4403
4404 static int __net_init packet_net_init(struct net *net)
4405 {
4406         mutex_init(&net->packet.sklist_lock);
4407         INIT_HLIST_HEAD(&net->packet.sklist);
4408
4409         if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
4410                 return -ENOMEM;
4411
4412         return 0;
4413 }
4414
4415 static void __net_exit packet_net_exit(struct net *net)
4416 {
4417         remove_proc_entry("packet", net->proc_net);
4418 }
4419
4420 static struct pernet_operations packet_net_ops = {
4421         .init = packet_net_init,
4422         .exit = packet_net_exit,
4423 };
4424
4425
4426 static void __exit packet_exit(void)
4427 {
4428         unregister_netdevice_notifier(&packet_netdev_notifier);
4429         unregister_pernet_subsys(&packet_net_ops);
4430         sock_unregister(PF_PACKET);
4431         proto_unregister(&packet_proto);
4432 }
4433
4434 static int __init packet_init(void)
4435 {
4436         int rc = proto_register(&packet_proto, 0);
4437
4438         if (rc != 0)
4439                 goto out;
4440
4441         sock_register(&packet_family_ops);
4442         register_pernet_subsys(&packet_net_ops);
4443         register_netdevice_notifier(&packet_netdev_notifier);
4444 out:
4445         return rc;
4446 }
4447
4448 module_init(packet_init);
4449 module_exit(packet_exit);
4450 MODULE_LICENSE("GPL");
4451 MODULE_ALIAS_NETPROTO(PF_PACKET);