net/sunrpc/xprtsock.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * linux/net/sunrpc/xprtsock.c
   4  *
   5  * Client-side transport implementation for sockets.
   6  *
   7  * TCP callback races fixes (C) 1998 Red Hat
   8  * TCP send fixes (C) 1998 Red Hat
   9  * TCP NFS related read + write fixes
  10  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
  11  *
  12  * Rewrite of larges part of the code in order to stabilize TCP stuff.
  13  * Fix behaviour when socket buffer is full.
  14  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
  15  *
  16  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
  17  *
  18  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
  19  *   <gilles.quillard@bull.net>
  20  */
  21
  22 #include <linux/types.h>
  23 #include <linux/string.h>
  24 #include <linux/slab.h>
  25 #include <linux/module.h>
  26 #include <linux/capability.h>
  27 #include <linux/pagemap.h>
  28 #include <linux/errno.h>
  29 #include <linux/socket.h>
  30 #include <linux/in.h>
  31 #include <linux/net.h>
  32 #include <linux/mm.h>
  33 #include <linux/un.h>
  34 #include <linux/udp.h>
  35 #include <linux/tcp.h>
  36 #include <linux/sunrpc/clnt.h>
  37 #include <linux/sunrpc/addr.h>
  38 #include <linux/sunrpc/sched.h>
  39 #include <linux/sunrpc/svcsock.h>
  40 #include <linux/sunrpc/xprtsock.h>
  41 #include <linux/file.h>
  42 #ifdef CONFIG_SUNRPC_BACKCHANNEL
  43 #include <linux/sunrpc/bc_xprt.h>
  44 #endif
  45
  46 #include <net/sock.h>
  47 #include <net/checksum.h>
  48 #include <net/udp.h>
  49 #include <net/tcp.h>
  50 #include <linux/bvec.h>
  51 #include <linux/highmem.h>
  52 #include <linux/uio.h>
  53 #include <linux/sched/mm.h>
  54
  55 #include <trace/events/sunrpc.h>
  56
  57 #include "sunrpc.h"
  58
  59 static void xs_close(struct rpc_xprt *xprt);
  60 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
  61                 struct socket *sock);
  62
  63 /*
  64  * xprtsock tunables
  65  */
  66 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
  67 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
  68 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
  69
  70 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
  71 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
  72
  73 #define XS_TCP_LINGER_TO        (15U * HZ)
  74 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
  75
  76 /*
  77  * We can register our own files under /proc/sys/sunrpc by
  78  * calling register_sysctl_table() again.  The files in that
  79  * directory become the union of all files registered there.
  80  *
  81  * We simply need to make sure that we don't collide with
  82  * someone else's file names!
  83  */
  84
  85 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
  86 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
  87 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
  88 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
  89 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
  90
  91 static struct ctl_table_header *sunrpc_table_header;
  92
  93 /*
  94  * FIXME: changing the UDP slot table size should also resize the UDP
  95  *        socket buffers for existing UDP transports
  96  */
  97 static struct ctl_table xs_tunables_table[] = {
  98         {
  99                 .procname       = "udp_slot_table_entries",
 100                 .data           = &xprt_udp_slot_table_entries,
 101                 .maxlen         = sizeof(unsigned int),
 102                 .mode           = 0644,
 103                 .proc_handler   = proc_dointvec_minmax,
 104                 .extra1         = &min_slot_table_size,
 105                 .extra2         = &max_slot_table_size
 106         },
 107         {
 108                 .procname       = "tcp_slot_table_entries",
 109                 .data           = &xprt_tcp_slot_table_entries,
 110                 .maxlen         = sizeof(unsigned int),
 111                 .mode           = 0644,
 112                 .proc_handler   = proc_dointvec_minmax,
 113                 .extra1         = &min_slot_table_size,
 114                 .extra2         = &max_slot_table_size
 115         },
 116         {
 117                 .procname       = "tcp_max_slot_table_entries",
 118                 .data           = &xprt_max_tcp_slot_table_entries,
 119                 .maxlen         = sizeof(unsigned int),
 120                 .mode           = 0644,
 121                 .proc_handler   = proc_dointvec_minmax,
 122                 .extra1         = &min_slot_table_size,
 123                 .extra2         = &max_tcp_slot_table_limit
 124         },
 125         {
 126                 .procname       = "min_resvport",
 127                 .data           = &xprt_min_resvport,
 128                 .maxlen         = sizeof(unsigned int),
 129                 .mode           = 0644,
 130                 .proc_handler   = proc_dointvec_minmax,
 131                 .extra1         = &xprt_min_resvport_limit,
 132                 .extra2         = &xprt_max_resvport_limit
 133         },
 134         {
 135                 .procname       = "max_resvport",
 136                 .data           = &xprt_max_resvport,
 137                 .maxlen         = sizeof(unsigned int),
 138                 .mode           = 0644,
 139                 .proc_handler   = proc_dointvec_minmax,
 140                 .extra1         = &xprt_min_resvport_limit,
 141                 .extra2         = &xprt_max_resvport_limit
 142         },
 143         {
 144                 .procname       = "tcp_fin_timeout",
 145                 .data           = &xs_tcp_fin_timeout,
 146                 .maxlen         = sizeof(xs_tcp_fin_timeout),
 147                 .mode           = 0644,
 148                 .proc_handler   = proc_dointvec_jiffies,
 149         },
 150         { },
 151 };
 152
 153 static struct ctl_table sunrpc_table[] = {
 154         {
 155                 .procname       = "sunrpc",
 156                 .mode           = 0555,
 157                 .child          = xs_tunables_table
 158         },
 159         { },
 160 };
 161
 162 /*
 163  * Wait duration for a reply from the RPC portmapper.
 164  */
 165 #define XS_BIND_TO              (60U * HZ)
 166
 167 /*
 168  * Delay if a UDP socket connect error occurs.  This is most likely some
 169  * kind of resource problem on the local host.
 170  */
 171 #define XS_UDP_REEST_TO         (2U * HZ)
 172
 173 /*
 174  * The reestablish timeout allows clients to delay for a bit before attempting
 175  * to reconnect to a server that just dropped our connection.
 176  *
 177  * We implement an exponential backoff when trying to reestablish a TCP
 178  * transport connection with the server.  Some servers like to drop a TCP
 179  * connection when they are overworked, so we start with a short timeout and
 180  * increase over time if the server is down or not responding.
 181  */
 182 #define XS_TCP_INIT_REEST_TO    (3U * HZ)
 183
 184 /*
 185  * TCP idle timeout; client drops the transport socket if it is idle
 186  * for this long.  Note that we also timeout UDP sockets to prevent
 187  * holding port numbers when there is no RPC traffic.
 188  */
 189 #define XS_IDLE_DISC_TO         (5U * 60 * HZ)
 190
 191 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 192 # undef  RPC_DEBUG_DATA
 193 # define RPCDBG_FACILITY        RPCDBG_TRANS
 194 #endif
 195
 196 #ifdef RPC_DEBUG_DATA
 197 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 198 {
 199         u8 *buf = (u8 *) packet;
 200         int j;
 201
 202         dprintk("RPC:       %s\n", msg);
 203         for (j = 0; j < count && j < 128; j += 4) {
 204                 if (!(j & 31)) {
 205                         if (j)
 206                                 dprintk("\n");
 207                         dprintk("0x%04x ", j);
 208                 }
 209                 dprintk("%02x%02x%02x%02x ",
 210                         buf[j], buf[j+1], buf[j+2], buf[j+3]);
 211         }
 212         dprintk("\n");
 213 }
 214 #else
 215 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 216 {
 217         /* NOP */
 218 }
 219 #endif
 220
 221 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
 222 {
 223         return (struct rpc_xprt *) sk->sk_user_data;
 224 }
 225
 226 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
 227 {
 228         return (struct sockaddr *) &xprt->addr;
 229 }
 230
 231 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
 232 {
 233         return (struct sockaddr_un *) &xprt->addr;
 234 }
 235
 236 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
 237 {
 238         return (struct sockaddr_in *) &xprt->addr;
 239 }
 240
 241 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
 242 {
 243         return (struct sockaddr_in6 *) &xprt->addr;
 244 }
 245
 246 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
 247 {
 248         struct sockaddr *sap = xs_addr(xprt);
 249         struct sockaddr_in6 *sin6;
 250         struct sockaddr_in *sin;
 251         struct sockaddr_un *sun;
 252         char buf[128];
 253
 254         switch (sap->sa_family) {
 255         case AF_LOCAL:
 256                 sun = xs_addr_un(xprt);
 257                 strlcpy(buf, sun->sun_path, sizeof(buf));
 258                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 259                                                 kstrdup(buf, GFP_KERNEL);
 260                 break;
 261         case AF_INET:
 262                 (void)rpc_ntop(sap, buf, sizeof(buf));
 263                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 264                                                 kstrdup(buf, GFP_KERNEL);
 265                 sin = xs_addr_in(xprt);
 266                 snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 267                 break;
 268         case AF_INET6:
 269                 (void)rpc_ntop(sap, buf, sizeof(buf));
 270                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 271                                                 kstrdup(buf, GFP_KERNEL);
 272                 sin6 = xs_addr_in6(xprt);
 273                 snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
 274                 break;
 275         default:
 276                 BUG();
 277         }
 278
 279         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 280 }
 281
 282 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
 283 {
 284         struct sockaddr *sap = xs_addr(xprt);
 285         char buf[128];
 286
 287         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 288         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 289
 290         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 291         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 292 }
 293
 294 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
 295                                      const char *protocol,
 296                                      const char *netid)
 297 {
 298         xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
 299         xprt->address_strings[RPC_DISPLAY_NETID] = netid;
 300         xs_format_common_peer_addresses(xprt);
 301         xs_format_common_peer_ports(xprt);
 302 }
 303
 304 static void xs_update_peer_port(struct rpc_xprt *xprt)
 305 {
 306         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
 307         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
 308
 309         xs_format_common_peer_ports(xprt);
 310 }
 311
 312 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
 313 {
 314         unsigned int i;
 315
 316         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 317                 switch (i) {
 318                 case RPC_DISPLAY_PROTO:
 319                 case RPC_DISPLAY_NETID:
 320                         continue;
 321                 default:
 322                         kfree(xprt->address_strings[i]);
 323                 }
 324 }
 325
 326 static size_t
 327 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
 328 {
 329         size_t i,n;
 330
 331         if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))
 332                 return want;
 333         n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
 334         for (i = 0; i < n; i++) {
 335                 if (buf->pages[i])
 336                         continue;
 337                 buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
 338                 if (!buf->pages[i]) {
 339                         i *= PAGE_SIZE;
 340                         return i > buf->page_base ? i - buf->page_base : 0;
 341                 }
 342         }
 343         return want;
 344 }
 345
 346 static ssize_t
 347 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
 348 {
 349         ssize_t ret;
 350         if (seek != 0)
 351                 iov_iter_advance(&msg->msg_iter, seek);
 352         ret = sock_recvmsg(sock, msg, flags);
 353         return ret > 0 ? ret + seek : ret;
 354 }
 355
 356 static ssize_t
 357 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
 358                 struct kvec *kvec, size_t count, size_t seek)
 359 {
 360         iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
 361         return xs_sock_recvmsg(sock, msg, flags, seek);
 362 }
 363
 364 static ssize_t
 365 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
 366                 struct bio_vec *bvec, unsigned long nr, size_t count,
 367                 size_t seek)
 368 {
 369         iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
 370         return xs_sock_recvmsg(sock, msg, flags, seek);
 371 }
 372
 373 static ssize_t
 374 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
 375                 size_t count)
 376 {
 377         iov_iter_discard(&msg->msg_iter, READ, count);
 378         return sock_recvmsg(sock, msg, flags);
 379 }
 380
 381 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 382 static void
 383 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
 384 {
 385         struct bvec_iter bi = {
 386                 .bi_size = count,
 387         };
 388         struct bio_vec bv;
 389
 390         bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
 391         for_each_bvec(bv, bvec, bi, bi)
 392                 flush_dcache_page(bv.bv_page);
 393 }
 394 #else
 395 static inline void
 396 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
 397 {
 398 }
 399 #endif
 400
 401 static ssize_t
 402 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
 403                 struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
 404 {
 405         size_t want, seek_init = seek, offset = 0;
 406         ssize_t ret;
 407
 408         want = min_t(size_t, count, buf->head[0].iov_len);
 409         if (seek < want) {
 410                 ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
 411                 if (ret <= 0)
 412                         goto sock_err;
 413                 offset += ret;
 414                 if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
 415                         goto out;
 416                 if (ret != want)
 417                         goto out;
 418                 seek = 0;
 419         } else {
 420                 seek -= want;
 421                 offset += want;
 422         }
 423
 424         want = xs_alloc_sparse_pages(buf,
 425                         min_t(size_t, count - offset, buf->page_len),
 426                         GFP_KERNEL);
 427         if (seek < want) {
 428                 ret = xs_read_bvec(sock, msg, flags, buf->bvec,
 429                                 xdr_buf_pagecount(buf),
 430                                 want + buf->page_base,
 431                                 seek + buf->page_base);
 432                 if (ret <= 0)
 433                         goto sock_err;
 434                 xs_flush_bvec(buf->bvec, ret, seek + buf->page_base);
 435                 offset += ret - buf->page_base;
 436                 if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
 437                         goto out;
 438                 if (ret != want)
 439                         goto out;
 440                 seek = 0;
 441         } else {
 442                 seek -= want;
 443                 offset += want;
 444         }
 445
 446         want = min_t(size_t, count - offset, buf->tail[0].iov_len);
 447         if (seek < want) {
 448                 ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
 449                 if (ret <= 0)
 450                         goto sock_err;
 451                 offset += ret;
 452                 if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
 453                         goto out;
 454                 if (ret != want)
 455                         goto out;
 456         } else if (offset < seek_init)
 457                 offset = seek_init;
 458         ret = -EMSGSIZE;
 459 out:
 460         *read = offset - seek_init;
 461         return ret;
 462 sock_err:
 463         offset += seek;
 464         goto out;
 465 }
 466
 467 static void
 468 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
 469 {
 470         if (!transport->recv.copied) {
 471                 if (buf->head[0].iov_len >= transport->recv.offset)
 472                         memcpy(buf->head[0].iov_base,
 473                                         &transport->recv.xid,
 474                                         transport->recv.offset);
 475                 transport->recv.copied = transport->recv.offset;
 476         }
 477 }
 478
 479 static bool
 480 xs_read_stream_request_done(struct sock_xprt *transport)
 481 {
 482         return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
 483 }
 484
 485 static void
 486 xs_read_stream_check_eor(struct sock_xprt *transport,
 487                 struct msghdr *msg)
 488 {
 489         if (xs_read_stream_request_done(transport))
 490                 msg->msg_flags |= MSG_EOR;
 491 }
 492
 493 static ssize_t
 494 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
 495                 int flags, struct rpc_rqst *req)
 496 {
 497         struct xdr_buf *buf = &req->rq_private_buf;
 498         size_t want, read;
 499         ssize_t ret;
 500
 501         xs_read_header(transport, buf);
 502
 503         want = transport->recv.len - transport->recv.offset;
 504         if (want != 0) {
 505                 ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
 506                                 transport->recv.copied + want,
 507                                 transport->recv.copied,
 508                                 &read);
 509                 transport->recv.offset += read;
 510                 transport->recv.copied += read;
 511         }
 512
 513         if (transport->recv.offset == transport->recv.len)
 514                 xs_read_stream_check_eor(transport, msg);
 515
 516         if (want == 0)
 517                 return 0;
 518
 519         switch (ret) {
 520         default:
 521                 break;
 522         case -EFAULT:
 523         case -EMSGSIZE:
 524                 msg->msg_flags |= MSG_TRUNC;
 525                 return read;
 526         case 0:
 527                 return -ESHUTDOWN;
 528         }
 529         return ret < 0 ? ret : read;
 530 }
 531
 532 static size_t
 533 xs_read_stream_headersize(bool isfrag)
 534 {
 535         if (isfrag)
 536                 return sizeof(__be32);
 537         return 3 * sizeof(__be32);
 538 }
 539
 540 static ssize_t
 541 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
 542                 int flags, size_t want, size_t seek)
 543 {
 544         struct kvec kvec = {
 545                 .iov_base = &transport->recv.fraghdr,
 546                 .iov_len = want,
 547         };
 548         return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
 549 }
 550
 551 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 552 static ssize_t
 553 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
 554 {
 555         struct rpc_xprt *xprt = &transport->xprt;
 556         struct rpc_rqst *req;
 557         ssize_t ret;
 558
 559         /* Look up and lock the request corresponding to the given XID */
 560         req = xprt_lookup_bc_request(xprt, transport->recv.xid);
 561         if (!req) {
 562                 printk(KERN_WARNING "Callback slot table overflowed\n");
 563                 return -ESHUTDOWN;
 564         }
 565
 566         ret = xs_read_stream_request(transport, msg, flags, req);
 567         if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
 568                 xprt_complete_bc_request(req, transport->recv.copied);
 569
 570         return ret;
 571 }
 572 #else /* CONFIG_SUNRPC_BACKCHANNEL */
 573 static ssize_t
 574 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
 575 {
 576         return -ESHUTDOWN;
 577 }
 578 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 579
 580 static ssize_t
 581 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
 582 {
 583         struct rpc_xprt *xprt = &transport->xprt;
 584         struct rpc_rqst *req;
 585         ssize_t ret = 0;
 586
 587         /* Look up and lock the request corresponding to the given XID */
 588         spin_lock(&xprt->queue_lock);
 589         req = xprt_lookup_rqst(xprt, transport->recv.xid);
 590         if (!req) {
 591                 msg->msg_flags |= MSG_TRUNC;
 592                 goto out;
 593         }
 594         xprt_pin_rqst(req);
 595         spin_unlock(&xprt->queue_lock);
 596
 597         ret = xs_read_stream_request(transport, msg, flags, req);
 598
 599         spin_lock(&xprt->queue_lock);
 600         if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
 601                 xprt_complete_rqst(req->rq_task, transport->recv.copied);
 602         xprt_unpin_rqst(req);
 603 out:
 604         spin_unlock(&xprt->queue_lock);
 605         return ret;
 606 }
 607
 608 static ssize_t
 609 xs_read_stream(struct sock_xprt *transport, int flags)
 610 {
 611         struct msghdr msg = { 0 };
 612         size_t want, read = 0;
 613         ssize_t ret = 0;
 614
 615         if (transport->recv.len == 0) {
 616                 want = xs_read_stream_headersize(transport->recv.copied != 0);
 617                 ret = xs_read_stream_header(transport, &msg, flags, want,
 618                                 transport->recv.offset);
 619                 if (ret <= 0)
 620                         goto out_err;
 621                 transport->recv.offset = ret;
 622                 if (transport->recv.offset != want)
 623                         return transport->recv.offset;
 624                 transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
 625                         RPC_FRAGMENT_SIZE_MASK;
 626                 transport->recv.offset -= sizeof(transport->recv.fraghdr);
 627                 read = ret;
 628         }
 629
 630         switch (be32_to_cpu(transport->recv.calldir)) {
 631         default:
 632                 msg.msg_flags |= MSG_TRUNC;
 633                 break;
 634         case RPC_CALL:
 635                 ret = xs_read_stream_call(transport, &msg, flags);
 636                 break;
 637         case RPC_REPLY:
 638                 ret = xs_read_stream_reply(transport, &msg, flags);
 639         }
 640         if (msg.msg_flags & MSG_TRUNC) {
 641                 transport->recv.calldir = cpu_to_be32(-1);
 642                 transport->recv.copied = -1;
 643         }
 644         if (ret < 0)
 645                 goto out_err;
 646         read += ret;
 647         if (transport->recv.offset < transport->recv.len) {
 648                 if (!(msg.msg_flags & MSG_TRUNC))
 649                         return read;
 650                 msg.msg_flags = 0;
 651                 ret = xs_read_discard(transport->sock, &msg, flags,
 652                                 transport->recv.len - transport->recv.offset);
 653                 if (ret <= 0)
 654                         goto out_err;
 655                 transport->recv.offset += ret;
 656                 read += ret;
 657                 if (transport->recv.offset != transport->recv.len)
 658                         return read;
 659         }
 660         if (xs_read_stream_request_done(transport)) {
 661                 trace_xs_stream_read_request(transport);
 662                 transport->recv.copied = 0;
 663         }
 664         transport->recv.offset = 0;
 665         transport->recv.len = 0;
 666         return read;
 667 out_err:
 668         return ret != 0 ? ret : -ESHUTDOWN;
 669 }
 670
 671 static __poll_t xs_poll_socket(struct sock_xprt *transport)
 672 {
 673         return transport->sock->ops->poll(transport->file, transport->sock,
 674                         NULL);
 675 }
 676
 677 static bool xs_poll_socket_readable(struct sock_xprt *transport)
 678 {
 679         __poll_t events = xs_poll_socket(transport);
 680
 681         return (events & (EPOLLIN | EPOLLRDNORM)) && !(events & EPOLLRDHUP);
 682 }
 683
 684 static void xs_poll_check_readable(struct sock_xprt *transport)
 685 {
 686
 687         clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
 688         if (!xs_poll_socket_readable(transport))
 689                 return;
 690         if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
 691                 queue_work(xprtiod_workqueue, &transport->recv_worker);
 692 }
 693
 694 static void xs_stream_data_receive(struct sock_xprt *transport)
 695 {
 696         size_t read = 0;
 697         ssize_t ret = 0;
 698
 699         mutex_lock(&transport->recv_mutex);
 700         if (transport->sock == NULL)
 701                 goto out;
 702         for (;;) {
 703                 ret = xs_read_stream(transport, MSG_DONTWAIT);
 704                 if (ret < 0)
 705                         break;
 706                 read += ret;
 707                 cond_resched();
 708         }
 709         if (ret == -ESHUTDOWN)
 710                 kernel_sock_shutdown(transport->sock, SHUT_RDWR);
 711         else
 712                 xs_poll_check_readable(transport);
 713 out:
 714         mutex_unlock(&transport->recv_mutex);
 715         trace_xs_stream_read_data(&transport->xprt, ret, read);
 716 }
 717
 718 static void xs_stream_data_receive_workfn(struct work_struct *work)
 719 {
 720         struct sock_xprt *transport =
 721                 container_of(work, struct sock_xprt, recv_worker);
 722         unsigned int pflags = memalloc_nofs_save();
 723
 724         xs_stream_data_receive(transport);
 725         memalloc_nofs_restore(pflags);
 726 }
 727
 728 static void
 729 xs_stream_reset_connect(struct sock_xprt *transport)
 730 {
 731         transport->recv.offset = 0;
 732         transport->recv.len = 0;
 733         transport->recv.copied = 0;
 734         transport->xmit.offset = 0;
 735 }
 736
 737 static void
 738 xs_stream_start_connect(struct sock_xprt *transport)
 739 {
 740         transport->xprt.stat.connect_count++;
 741         transport->xprt.stat.connect_start = jiffies;
 742 }
 743
 744 #define XS_SENDMSG_FLAGS        (MSG_DONTWAIT | MSG_NOSIGNAL)
 745
 746 static int xs_sendmsg(struct socket *sock, struct msghdr *msg, size_t seek)
 747 {
 748         if (seek)
 749                 iov_iter_advance(&msg->msg_iter, seek);
 750         return sock_sendmsg(sock, msg);
 751 }
 752
 753 static int xs_send_kvec(struct socket *sock, struct msghdr *msg, struct kvec *vec, size_t seek)
 754 {
 755         iov_iter_kvec(&msg->msg_iter, WRITE, vec, 1, vec->iov_len);
 756         return xs_sendmsg(sock, msg, seek);
 757 }
 758
 759 static int xs_send_pagedata(struct socket *sock, struct msghdr *msg, struct xdr_buf *xdr, size_t base)
 760 {
 761         int err;
 762
 763         err = xdr_alloc_bvec(xdr, GFP_KERNEL);
 764         if (err < 0)
 765                 return err;
 766
 767         iov_iter_bvec(&msg->msg_iter, WRITE, xdr->bvec,
 768                         xdr_buf_pagecount(xdr),
 769                         xdr->page_len + xdr->page_base);
 770         return xs_sendmsg(sock, msg, base + xdr->page_base);
 771 }
 772
 773 #define xs_record_marker_len() sizeof(rpc_fraghdr)
 774
 775 /* Common case:
 776  *  - stream transport
 777  *  - sending from byte 0 of the message
 778  *  - the message is wholly contained in @xdr's head iovec
 779  */
 780 static int xs_send_rm_and_kvec(struct socket *sock, struct msghdr *msg,
 781                 rpc_fraghdr marker, struct kvec *vec, size_t base)
 782 {
 783         struct kvec iov[2] = {
 784                 [0] = {
 785                         .iov_base       = &marker,
 786                         .iov_len        = sizeof(marker)
 787                 },
 788                 [1] = *vec,
 789         };
 790         size_t len = iov[0].iov_len + iov[1].iov_len;
 791
 792         iov_iter_kvec(&msg->msg_iter, WRITE, iov, 2, len);
 793         return xs_sendmsg(sock, msg, base);
 794 }
 795
 796 /**
 797  * xs_sendpages - write pages directly to a socket
 798  * @sock: socket to send on
 799  * @addr: UDP only -- address of destination
 800  * @addrlen: UDP only -- length of destination address
 801  * @xdr: buffer containing this request
 802  * @base: starting position in the buffer
 803  * @rm: stream record marker field
 804  * @sent_p: return the total number of bytes successfully queued for sending
 805  *
 806  */
 807 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, rpc_fraghdr rm, int *sent_p)
 808 {
 809         struct msghdr msg = {
 810                 .msg_name = addr,
 811                 .msg_namelen = addrlen,
 812                 .msg_flags = XS_SENDMSG_FLAGS | MSG_MORE,
 813         };
 814         unsigned int rmsize = rm ? sizeof(rm) : 0;
 815         unsigned int remainder = rmsize + xdr->len - base;
 816         unsigned int want;
 817         int err = 0;
 818
 819         if (unlikely(!sock))
 820                 return -ENOTSOCK;
 821
 822         want = xdr->head[0].iov_len + rmsize;
 823         if (base < want) {
 824                 unsigned int len = want - base;
 825                 remainder -= len;
 826                 if (remainder == 0)
 827                         msg.msg_flags &= ~MSG_MORE;
 828                 if (rmsize)
 829                         err = xs_send_rm_and_kvec(sock, &msg, rm,
 830                                         &xdr->head[0], base);
 831                 else
 832                         err = xs_send_kvec(sock, &msg, &xdr->head[0], base);
 833                 if (remainder == 0 || err != len)
 834                         goto out;
 835                 *sent_p += err;
 836                 base = 0;
 837         } else
 838                 base -= want;
 839
 840         if (base < xdr->page_len) {
 841                 unsigned int len = xdr->page_len - base;
 842                 remainder -= len;
 843                 if (remainder == 0)
 844                         msg.msg_flags &= ~MSG_MORE;
 845                 err = xs_send_pagedata(sock, &msg, xdr, base);
 846                 if (remainder == 0 || err != len)
 847                         goto out;
 848                 *sent_p += err;
 849                 base = 0;
 850         } else
 851                 base -= xdr->page_len;
 852
 853         if (base >= xdr->tail[0].iov_len)
 854                 return 0;
 855         msg.msg_flags &= ~MSG_MORE;
 856         err = xs_send_kvec(sock, &msg, &xdr->tail[0], base);
 857 out:
 858         if (err > 0) {
 859                 *sent_p += err;
 860                 err = 0;
 861         }
 862         return err;
 863 }
 864
 865 /**
 866  * xs_nospace - handle transmit was incomplete
 867  * @req: pointer to RPC request
 868  *
 869  */
 870 static int xs_nospace(struct rpc_rqst *req)
 871 {
 872         struct rpc_xprt *xprt = req->rq_xprt;
 873         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 874         struct sock *sk = transport->inet;
 875         int ret = -EAGAIN;
 876
 877         dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
 878                         req->rq_task->tk_pid,
 879                         req->rq_slen - transport->xmit.offset,
 880                         req->rq_slen);
 881
 882         /* Protect against races with write_space */
 883         spin_lock_bh(&xprt->transport_lock);
 884
 885         /* Don't race with disconnect */
 886         if (xprt_connected(xprt)) {
 887                 /* wait for more buffer space */
 888                 sk->sk_write_pending++;
 889                 xprt_wait_for_buffer_space(xprt);
 890         } else
 891                 ret = -ENOTCONN;
 892
 893         spin_unlock_bh(&xprt->transport_lock);
 894
 895         /* Race breaker in case memory is freed before above code is called */
 896         if (ret == -EAGAIN) {
 897                 struct socket_wq *wq;
 898
 899                 rcu_read_lock();
 900                 wq = rcu_dereference(sk->sk_wq);
 901                 set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
 902                 rcu_read_unlock();
 903
 904                 sk->sk_write_space(sk);
 905         }
 906         return ret;
 907 }
 908
 909 static void
 910 xs_stream_prepare_request(struct rpc_rqst *req)
 911 {
 912         req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf, GFP_KERNEL);
 913 }
 914
 915 /*
 916  * Determine if the previous message in the stream was aborted before it
 917  * could complete transmission.
 918  */
 919 static bool
 920 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
 921 {
 922         return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
 923 }
 924
 925 /*
 926  * Return the stream record marker field for a record of length < 2^31-1
 927  */
 928 static rpc_fraghdr
 929 xs_stream_record_marker(struct xdr_buf *xdr)
 930 {
 931         if (!xdr->len)
 932                 return 0;
 933         return cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | (u32)xdr->len);
 934 }
 935
 936 /**
 937  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
 938  * @req: pointer to RPC request
 939  *
 940  * Return values:
 941  *        0:    The request has been sent
 942  *   EAGAIN:    The socket was blocked, please call again later to
 943  *              complete the request
 944  * ENOTCONN:    Caller needs to invoke connect logic then call again
 945  *    other:    Some other error occured, the request was not sent
 946  */
 947 static int xs_local_send_request(struct rpc_rqst *req)
 948 {
 949         struct rpc_xprt *xprt = req->rq_xprt;
 950         struct sock_xprt *transport =
 951                                 container_of(xprt, struct sock_xprt, xprt);
 952         struct xdr_buf *xdr = &req->rq_snd_buf;
 953         int status;
 954         int sent = 0;
 955
 956         /* Close the stream if the previous transmission was incomplete */
 957         if (xs_send_request_was_aborted(transport, req)) {
 958                 xs_close(xprt);
 959                 return -ENOTCONN;
 960         }
 961
 962         xs_pktdump("packet data:",
 963                         req->rq_svec->iov_base, req->rq_svec->iov_len);
 964
 965         req->rq_xtime = ktime_get();
 966         status = xs_sendpages(transport->sock, NULL, 0, xdr,
 967                               transport->xmit.offset,
 968                               xs_stream_record_marker(xdr),
 969                               &sent);
 970         dprintk("RPC:       %s(%u) = %d\n",
 971                         __func__, xdr->len - transport->xmit.offset, status);
 972
 973         if (status == -EAGAIN && sock_writeable(transport->inet))
 974                 status = -ENOBUFS;
 975
 976         if (likely(sent > 0) || status == 0) {
 977                 transport->xmit.offset += sent;
 978                 req->rq_bytes_sent = transport->xmit.offset;
 979                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 980                         req->rq_xmit_bytes_sent += transport->xmit.offset;
 981                         transport->xmit.offset = 0;
 982                         return 0;
 983                 }
 984                 status = -EAGAIN;
 985         }
 986
 987         switch (status) {
 988         case -ENOBUFS:
 989                 break;
 990         case -EAGAIN:
 991                 status = xs_nospace(req);
 992                 break;
 993         default:
 994                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 995                         -status);
 996                 /* fall through */
 997         case -EPIPE:
 998                 xs_close(xprt);
 999                 status = -ENOTCONN;
1000         }
1001
1002         return status;
1003 }
1004
1005 /**
1006  * xs_udp_send_request - write an RPC request to a UDP socket
1007  * @req: pointer to RPC request
1008  *
1009  * Return values:
1010  *        0:    The request has been sent
1011  *   EAGAIN:    The socket was blocked, please call again later to
1012  *              complete the request
1013  * ENOTCONN:    Caller needs to invoke connect logic then call again
1014  *    other:    Some other error occurred, the request was not sent
1015  */
1016 static int xs_udp_send_request(struct rpc_rqst *req)
1017 {
1018         struct rpc_xprt *xprt = req->rq_xprt;
1019         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1020         struct xdr_buf *xdr = &req->rq_snd_buf;
1021         int sent = 0;
1022         int status;
1023
1024         xs_pktdump("packet data:",
1025                                 req->rq_svec->iov_base,
1026                                 req->rq_svec->iov_len);
1027
1028         if (!xprt_bound(xprt))
1029                 return -ENOTCONN;
1030
1031         if (!xprt_request_get_cong(xprt, req))
1032                 return -EBADSLT;
1033
1034         req->rq_xtime = ktime_get();
1035         status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
1036                               xdr, 0, 0, &sent);
1037
1038         dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
1039                         xdr->len, status);
1040
1041         /* firewall is blocking us, don't return -EAGAIN or we end up looping */
1042         if (status == -EPERM)
1043                 goto process_status;
1044
1045         if (status == -EAGAIN && sock_writeable(transport->inet))
1046                 status = -ENOBUFS;
1047
1048         if (sent > 0 || status == 0) {
1049                 req->rq_xmit_bytes_sent += sent;
1050                 if (sent >= req->rq_slen)
1051                         return 0;
1052                 /* Still some bytes left; set up for a retry later. */
1053                 status = -EAGAIN;
1054         }
1055
1056 process_status:
1057         switch (status) {
1058         case -ENOTSOCK:
1059                 status = -ENOTCONN;
1060                 /* Should we call xs_close() here? */
1061                 break;
1062         case -EAGAIN:
1063                 status = xs_nospace(req);
1064                 break;
1065         case -ENETUNREACH:
1066         case -ENOBUFS:
1067         case -EPIPE:
1068         case -ECONNREFUSED:
1069         case -EPERM:
1070                 /* When the server has died, an ICMP port unreachable message
1071                  * prompts ECONNREFUSED. */
1072                 break;
1073         default:
1074                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1075                         -status);
1076         }
1077
1078         return status;
1079 }
1080
1081 /**
1082  * xs_tcp_send_request - write an RPC request to a TCP socket
1083  * @req: pointer to RPC request
1084  *
1085  * Return values:
1086  *        0:    The request has been sent
1087  *   EAGAIN:    The socket was blocked, please call again later to
1088  *              complete the request
1089  * ENOTCONN:    Caller needs to invoke connect logic then call again
1090  *    other:    Some other error occurred, the request was not sent
1091  *
1092  * XXX: In the case of soft timeouts, should we eventually give up
1093  *      if sendmsg is not able to make progress?
1094  */
1095 static int xs_tcp_send_request(struct rpc_rqst *req)
1096 {
1097         struct rpc_xprt *xprt = req->rq_xprt;
1098         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1099         struct xdr_buf *xdr = &req->rq_snd_buf;
1100         bool vm_wait = false;
1101         int status;
1102         int sent;
1103
1104         /* Close the stream if the previous transmission was incomplete */
1105         if (xs_send_request_was_aborted(transport, req)) {
1106                 if (transport->sock != NULL)
1107                         kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1108                 return -ENOTCONN;
1109         }
1110
1111         xs_pktdump("packet data:",
1112                                 req->rq_svec->iov_base,
1113                                 req->rq_svec->iov_len);
1114
1115         if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1116                 xs_tcp_set_socket_timeouts(xprt, transport->sock);
1117
1118         /* Continue transmitting the packet/record. We must be careful
1119          * to cope with writespace callbacks arriving _after_ we have
1120          * called sendmsg(). */
1121         req->rq_xtime = ktime_get();
1122         while (1) {
1123                 sent = 0;
1124                 status = xs_sendpages(transport->sock, NULL, 0, xdr,
1125                                       transport->xmit.offset,
1126                                       xs_stream_record_marker(xdr),
1127                                       &sent);
1128
1129                 dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1130                                 xdr->len - transport->xmit.offset, status);
1131
1132                 /* If we've sent the entire packet, immediately
1133                  * reset the count of bytes sent. */
1134                 transport->xmit.offset += sent;
1135                 req->rq_bytes_sent = transport->xmit.offset;
1136                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
1137                         req->rq_xmit_bytes_sent += transport->xmit.offset;
1138                         transport->xmit.offset = 0;
1139                         return 0;
1140                 }
1141
1142                 WARN_ON_ONCE(sent == 0 && status == 0);
1143
1144                 if (status == -EAGAIN ) {
1145                         /*
1146                          * Return EAGAIN if we're sure we're hitting the
1147                          * socket send buffer limits.
1148                          */
1149                         if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
1150                                 break;
1151                         /*
1152                          * Did we hit a memory allocation failure?
1153                          */
1154                         if (sent == 0) {
1155                                 status = -ENOBUFS;
1156                                 if (vm_wait)
1157                                         break;
1158                                 /* Retry, knowing now that we're below the
1159                                  * socket send buffer limit
1160                                  */
1161                                 vm_wait = true;
1162                         }
1163                         continue;
1164                 }
1165                 if (status < 0)
1166                         break;
1167                 vm_wait = false;
1168         }
1169
1170         switch (status) {
1171         case -ENOTSOCK:
1172                 status = -ENOTCONN;
1173                 /* Should we call xs_close() here? */
1174                 break;
1175         case -EAGAIN:
1176                 status = xs_nospace(req);
1177                 break;
1178         case -ECONNRESET:
1179         case -ECONNREFUSED:
1180         case -ENOTCONN:
1181         case -EADDRINUSE:
1182         case -ENOBUFS:
1183         case -EPIPE:
1184                 break;
1185         default:
1186                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1187                         -status);
1188         }
1189
1190         return status;
1191 }
1192
1193 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1194 {
1195         transport->old_data_ready = sk->sk_data_ready;
1196         transport->old_state_change = sk->sk_state_change;
1197         transport->old_write_space = sk->sk_write_space;
1198         transport->old_error_report = sk->sk_error_report;
1199 }
1200
1201 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1202 {
1203         sk->sk_data_ready = transport->old_data_ready;
1204         sk->sk_state_change = transport->old_state_change;
1205         sk->sk_write_space = transport->old_write_space;
1206         sk->sk_error_report = transport->old_error_report;
1207 }
1208
1209 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1210 {
1211         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1212
1213         clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1214 }
1215
1216 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1217 {
1218         smp_mb__before_atomic();
1219         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1220         clear_bit(XPRT_CLOSING, &xprt->state);
1221         xs_sock_reset_state_flags(xprt);
1222         smp_mb__after_atomic();
1223 }
1224
1225 /**
1226  * xs_error_report - callback to handle TCP socket state errors
1227  * @sk: socket
1228  *
1229  * Note: we don't call sock_error() since there may be a rpc_task
1230  * using the socket, and so we don't want to clear sk->sk_err.
1231  */
1232 static void xs_error_report(struct sock *sk)
1233 {
1234         struct rpc_xprt *xprt;
1235         int err;
1236
1237         read_lock_bh(&sk->sk_callback_lock);
1238         if (!(xprt = xprt_from_sock(sk)))
1239                 goto out;
1240
1241         err = -sk->sk_err;
1242         if (err == 0)
1243                 goto out;
1244         dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1245                         xprt, -err);
1246         trace_rpc_socket_error(xprt, sk->sk_socket, err);
1247         xprt_wake_pending_tasks(xprt, err);
1248  out:
1249         read_unlock_bh(&sk->sk_callback_lock);
1250 }
1251
1252 static void xs_reset_transport(struct sock_xprt *transport)
1253 {
1254         struct socket *sock = transport->sock;
1255         struct sock *sk = transport->inet;
1256         struct rpc_xprt *xprt = &transport->xprt;
1257         struct file *filp = transport->file;
1258
1259         if (sk == NULL)
1260                 return;
1261
1262         if (atomic_read(&transport->xprt.swapper))
1263                 sk_clear_memalloc(sk);
1264
1265         kernel_sock_shutdown(sock, SHUT_RDWR);
1266
1267         mutex_lock(&transport->recv_mutex);
1268         write_lock_bh(&sk->sk_callback_lock);
1269         transport->inet = NULL;
1270         transport->sock = NULL;
1271         transport->file = NULL;
1272
1273         sk->sk_user_data = NULL;
1274
1275         xs_restore_old_callbacks(transport, sk);
1276         xprt_clear_connected(xprt);
1277         write_unlock_bh(&sk->sk_callback_lock);
1278         xs_sock_reset_connection_flags(xprt);
1279         /* Reset stream record info */
1280         xs_stream_reset_connect(transport);
1281         mutex_unlock(&transport->recv_mutex);
1282
1283         trace_rpc_socket_close(xprt, sock);
1284         fput(filp);
1285
1286         xprt_disconnect_done(xprt);
1287 }
1288
1289 /**
1290  * xs_close - close a socket
1291  * @xprt: transport
1292  *
1293  * This is used when all requests are complete; ie, no DRC state remains
1294  * on the server we want to save.
1295  *
1296  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1297  * xs_reset_transport() zeroing the socket from underneath a writer.
1298  */
1299 static void xs_close(struct rpc_xprt *xprt)
1300 {
1301         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1302
1303         dprintk("RPC:       xs_close xprt %p\n", xprt);
1304
1305         xs_reset_transport(transport);
1306         xprt->reestablish_timeout = 0;
1307 }
1308
1309 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1310 {
1311         dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1312                 xprt);
1313         xprt_disconnect_done(xprt);
1314 }
1315
1316 static void xs_xprt_free(struct rpc_xprt *xprt)
1317 {
1318         xs_free_peer_addresses(xprt);
1319         xprt_free(xprt);
1320 }
1321
1322 /**
1323  * xs_destroy - prepare to shutdown a transport
1324  * @xprt: doomed transport
1325  *
1326  */
1327 static void xs_destroy(struct rpc_xprt *xprt)
1328 {
1329         struct sock_xprt *transport = container_of(xprt,
1330                         struct sock_xprt, xprt);
1331         dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1332
1333         cancel_delayed_work_sync(&transport->connect_worker);
1334         xs_close(xprt);
1335         cancel_work_sync(&transport->recv_worker);
1336         xs_xprt_free(xprt);
1337         module_put(THIS_MODULE);
1338 }
1339
1340 /**
1341  * xs_udp_data_read_skb - receive callback for UDP sockets
1342  * @xprt: transport
1343  * @sk: socket
1344  * @skb: skbuff
1345  *
1346  */
1347 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1348                 struct sock *sk,
1349                 struct sk_buff *skb)
1350 {
1351         struct rpc_task *task;
1352         struct rpc_rqst *rovr;
1353         int repsize, copied;
1354         u32 _xid;
1355         __be32 *xp;
1356
1357         repsize = skb->len;
1358         if (repsize < 4) {
1359                 dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1360                 return;
1361         }
1362
1363         /* Copy the XID from the skb... */
1364         xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1365         if (xp == NULL)
1366                 return;
1367
1368         /* Look up and lock the request corresponding to the given XID */
1369         spin_lock(&xprt->queue_lock);
1370         rovr = xprt_lookup_rqst(xprt, *xp);
1371         if (!rovr)
1372                 goto out_unlock;
1373         xprt_pin_rqst(rovr);
1374         xprt_update_rtt(rovr->rq_task);
1375         spin_unlock(&xprt->queue_lock);
1376         task = rovr->rq_task;
1377
1378         if ((copied = rovr->rq_private_buf.buflen) > repsize)
1379                 copied = repsize;
1380
1381         /* Suck it into the iovec, verify checksum if not done by hw. */
1382         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1383                 spin_lock(&xprt->queue_lock);
1384                 __UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1385                 goto out_unpin;
1386         }
1387
1388
1389         spin_lock_bh(&xprt->transport_lock);
1390         xprt_adjust_cwnd(xprt, task, copied);
1391         spin_unlock_bh(&xprt->transport_lock);
1392         spin_lock(&xprt->queue_lock);
1393         xprt_complete_rqst(task, copied);
1394         __UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1395 out_unpin:
1396         xprt_unpin_rqst(rovr);
1397  out_unlock:
1398         spin_unlock(&xprt->queue_lock);
1399 }
1400
1401 static void xs_udp_data_receive(struct sock_xprt *transport)
1402 {
1403         struct sk_buff *skb;
1404         struct sock *sk;
1405         int err;
1406
1407         mutex_lock(&transport->recv_mutex);
1408         sk = transport->inet;
1409         if (sk == NULL)
1410                 goto out;
1411         for (;;) {
1412                 skb = skb_recv_udp(sk, 0, 1, &err);
1413                 if (skb == NULL)
1414                         break;
1415                 xs_udp_data_read_skb(&transport->xprt, sk, skb);
1416                 consume_skb(skb);
1417                 cond_resched();
1418         }
1419         xs_poll_check_readable(transport);
1420 out:
1421         mutex_unlock(&transport->recv_mutex);
1422 }
1423
1424 static void xs_udp_data_receive_workfn(struct work_struct *work)
1425 {
1426         struct sock_xprt *transport =
1427                 container_of(work, struct sock_xprt, recv_worker);
1428         unsigned int pflags = memalloc_nofs_save();
1429
1430         xs_udp_data_receive(transport);
1431         memalloc_nofs_restore(pflags);
1432 }
1433
1434 /**
1435  * xs_data_ready - "data ready" callback for UDP sockets
1436  * @sk: socket with data to read
1437  *
1438  */
1439 static void xs_data_ready(struct sock *sk)
1440 {
1441         struct rpc_xprt *xprt;
1442
1443         read_lock_bh(&sk->sk_callback_lock);
1444         dprintk("RPC:       xs_data_ready...\n");
1445         xprt = xprt_from_sock(sk);
1446         if (xprt != NULL) {
1447                 struct sock_xprt *transport = container_of(xprt,
1448                                 struct sock_xprt, xprt);
1449                 transport->old_data_ready(sk);
1450                 /* Any data means we had a useful conversation, so
1451                  * then we don't need to delay the next reconnect
1452                  */
1453                 if (xprt->reestablish_timeout)
1454                         xprt->reestablish_timeout = 0;
1455                 if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1456                         queue_work(xprtiod_workqueue, &transport->recv_worker);
1457         }
1458         read_unlock_bh(&sk->sk_callback_lock);
1459 }
1460
1461 /*
1462  * Helper function to force a TCP close if the server is sending
1463  * junk and/or it has put us in CLOSE_WAIT
1464  */
1465 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1466 {
1467         xprt_force_disconnect(xprt);
1468 }
1469
1470 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1471 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1472 {
1473         return PAGE_SIZE;
1474 }
1475 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1476
1477 /**
1478  * xs_tcp_state_change - callback to handle TCP socket state changes
1479  * @sk: socket whose state has changed
1480  *
1481  */
1482 static void xs_tcp_state_change(struct sock *sk)
1483 {
1484         struct rpc_xprt *xprt;
1485         struct sock_xprt *transport;
1486
1487         read_lock_bh(&sk->sk_callback_lock);
1488         if (!(xprt = xprt_from_sock(sk)))
1489                 goto out;
1490         dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1491         dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1492                         sk->sk_state, xprt_connected(xprt),
1493                         sock_flag(sk, SOCK_DEAD),
1494                         sock_flag(sk, SOCK_ZAPPED),
1495                         sk->sk_shutdown);
1496
1497         transport = container_of(xprt, struct sock_xprt, xprt);
1498         trace_rpc_socket_state_change(xprt, sk->sk_socket);
1499         switch (sk->sk_state) {
1500         case TCP_ESTABLISHED:
1501                 spin_lock(&xprt->transport_lock);
1502                 if (!xprt_test_and_set_connected(xprt)) {
1503                         xprt->connect_cookie++;
1504                         clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1505                         xprt_clear_connecting(xprt);
1506
1507                         xprt->stat.connect_count++;
1508                         xprt->stat.connect_time += (long)jiffies -
1509                                                    xprt->stat.connect_start;
1510                         xprt_wake_pending_tasks(xprt, -EAGAIN);
1511                 }
1512                 spin_unlock(&xprt->transport_lock);
1513                 break;
1514         case TCP_FIN_WAIT1:
1515                 /* The client initiated a shutdown of the socket */
1516                 xprt->connect_cookie++;
1517                 xprt->reestablish_timeout = 0;
1518                 set_bit(XPRT_CLOSING, &xprt->state);
1519                 smp_mb__before_atomic();
1520                 clear_bit(XPRT_CONNECTED, &xprt->state);
1521                 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1522                 smp_mb__after_atomic();
1523                 break;
1524         case TCP_CLOSE_WAIT:
1525                 /* The server initiated a shutdown of the socket */
1526                 xprt->connect_cookie++;
1527                 clear_bit(XPRT_CONNECTED, &xprt->state);
1528                 xs_tcp_force_close(xprt);
1529                 /* fall through */
1530         case TCP_CLOSING:
1531                 /*
1532                  * If the server closed down the connection, make sure that
1533                  * we back off before reconnecting
1534                  */
1535                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1536                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1537                 break;
1538         case TCP_LAST_ACK:
1539                 set_bit(XPRT_CLOSING, &xprt->state);
1540                 smp_mb__before_atomic();
1541                 clear_bit(XPRT_CONNECTED, &xprt->state);
1542                 smp_mb__after_atomic();
1543                 break;
1544         case TCP_CLOSE:
1545                 if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1546                                         &transport->sock_state))
1547                         xprt_clear_connecting(xprt);
1548                 clear_bit(XPRT_CLOSING, &xprt->state);
1549                 /* Trigger the socket release */
1550                 xs_tcp_force_close(xprt);
1551         }
1552  out:
1553         read_unlock_bh(&sk->sk_callback_lock);
1554 }
1555
1556 static void xs_write_space(struct sock *sk)
1557 {
1558         struct socket_wq *wq;
1559         struct rpc_xprt *xprt;
1560
1561         if (!sk->sk_socket)
1562                 return;
1563         clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1564
1565         if (unlikely(!(xprt = xprt_from_sock(sk))))
1566                 return;
1567         rcu_read_lock();
1568         wq = rcu_dereference(sk->sk_wq);
1569         if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1570                 goto out;
1571
1572         if (xprt_write_space(xprt))
1573                 sk->sk_write_pending--;
1574 out:
1575         rcu_read_unlock();
1576 }
1577
1578 /**
1579  * xs_udp_write_space - callback invoked when socket buffer space
1580  *                             becomes available
1581  * @sk: socket whose state has changed
1582  *
1583  * Called when more output buffer space is available for this socket.
1584  * We try not to wake our writers until they can make "significant"
1585  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1586  * with a bunch of small requests.
1587  */
1588 static void xs_udp_write_space(struct sock *sk)
1589 {
1590         read_lock_bh(&sk->sk_callback_lock);
1591
1592         /* from net/core/sock.c:sock_def_write_space */
1593         if (sock_writeable(sk))
1594                 xs_write_space(sk);
1595
1596         read_unlock_bh(&sk->sk_callback_lock);
1597 }
1598
1599 /**
1600  * xs_tcp_write_space - callback invoked when socket buffer space
1601  *                             becomes available
1602  * @sk: socket whose state has changed
1603  *
1604  * Called when more output buffer space is available for this socket.
1605  * We try not to wake our writers until they can make "significant"
1606  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1607  * with a bunch of small requests.
1608  */
1609 static void xs_tcp_write_space(struct sock *sk)
1610 {
1611         read_lock_bh(&sk->sk_callback_lock);
1612
1613         /* from net/core/stream.c:sk_stream_write_space */
1614         if (sk_stream_is_writeable(sk))
1615                 xs_write_space(sk);
1616
1617         read_unlock_bh(&sk->sk_callback_lock);
1618 }
1619
1620 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1621 {
1622         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1623         struct sock *sk = transport->inet;
1624
1625         if (transport->rcvsize) {
1626                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1627                 sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1628         }
1629         if (transport->sndsize) {
1630                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1631                 sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1632                 sk->sk_write_space(sk);
1633         }
1634 }
1635
1636 /**
1637  * xs_udp_set_buffer_size - set send and receive limits
1638  * @xprt: generic transport
1639  * @sndsize: requested size of send buffer, in bytes
1640  * @rcvsize: requested size of receive buffer, in bytes
1641  *
1642  * Set socket send and receive buffer size limits.
1643  */
1644 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1645 {
1646         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1647
1648         transport->sndsize = 0;
1649         if (sndsize)
1650                 transport->sndsize = sndsize + 1024;
1651         transport->rcvsize = 0;
1652         if (rcvsize)
1653                 transport->rcvsize = rcvsize + 1024;
1654
1655         xs_udp_do_set_buffer_size(xprt);
1656 }
1657
1658 /**
1659  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1660  * @xprt: controlling transport
1661  * @task: task that timed out
1662  *
1663  * Adjust the congestion window after a retransmit timeout has occurred.
1664  */
1665 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1666 {
1667         spin_lock_bh(&xprt->transport_lock);
1668         xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1669         spin_unlock_bh(&xprt->transport_lock);
1670 }
1671
1672 static int xs_get_random_port(void)
1673 {
1674         unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1675         unsigned short range;
1676         unsigned short rand;
1677
1678         if (max < min)
1679                 return -EADDRINUSE;
1680         range = max - min + 1;
1681         rand = (unsigned short) prandom_u32() % range;
1682         return rand + min;
1683 }
1684
1685 /**
1686  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1687  * @sock: socket
1688  *
1689  * Note that this function has to be called on all sockets that share the
1690  * same port, and it must be called before binding.
1691  */
1692 static void xs_sock_set_reuseport(struct socket *sock)
1693 {
1694         int opt = 1;
1695
1696         kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
1697                         (char *)&opt, sizeof(opt));
1698 }
1699
1700 static unsigned short xs_sock_getport(struct socket *sock)
1701 {
1702         struct sockaddr_storage buf;
1703         unsigned short port = 0;
1704
1705         if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1706                 goto out;
1707         switch (buf.ss_family) {
1708         case AF_INET6:
1709                 port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1710                 break;
1711         case AF_INET:
1712                 port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1713         }
1714 out:
1715         return port;
1716 }
1717
1718 /**
1719  * xs_set_port - reset the port number in the remote endpoint address
1720  * @xprt: generic transport
1721  * @port: new port number
1722  *
1723  */
1724 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1725 {
1726         dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1727
1728         rpc_set_port(xs_addr(xprt), port);
1729         xs_update_peer_port(xprt);
1730 }
1731
1732 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1733 {
1734         if (transport->srcport == 0)
1735                 transport->srcport = xs_sock_getport(sock);
1736 }
1737
1738 static int xs_get_srcport(struct sock_xprt *transport)
1739 {
1740         int port = transport->srcport;
1741
1742         if (port == 0 && transport->xprt.resvport)
1743                 port = xs_get_random_port();
1744         return port;
1745 }
1746
1747 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1748 {
1749         if (transport->srcport != 0)
1750                 transport->srcport = 0;
1751         if (!transport->xprt.resvport)
1752                 return 0;
1753         if (port <= xprt_min_resvport || port > xprt_max_resvport)
1754                 return xprt_max_resvport;
1755         return --port;
1756 }
1757 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1758 {
1759         struct sockaddr_storage myaddr;
1760         int err, nloop = 0;
1761         int port = xs_get_srcport(transport);
1762         unsigned short last;
1763
1764         /*
1765          * If we are asking for any ephemeral port (i.e. port == 0 &&
1766          * transport->xprt.resvport == 0), don't bind.  Let the local
1767          * port selection happen implicitly when the socket is used
1768          * (for example at connect time).
1769          *
1770          * This ensures that we can continue to establish TCP
1771          * connections even when all local ephemeral ports are already
1772          * a part of some TCP connection.  This makes no difference
1773          * for UDP sockets, but also doens't harm them.
1774          *
1775          * If we're asking for any reserved port (i.e. port == 0 &&
1776          * transport->xprt.resvport == 1) xs_get_srcport above will
1777          * ensure that port is non-zero and we will bind as needed.
1778          */
1779         if (port <= 0)
1780                 return port;
1781
1782         memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1783         do {
1784                 rpc_set_port((struct sockaddr *)&myaddr, port);
1785                 err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1786                                 transport->xprt.addrlen);
1787                 if (err == 0) {
1788                         transport->srcport = port;
1789                         break;
1790                 }
1791                 last = port;
1792                 port = xs_next_srcport(transport, port);
1793                 if (port > last)
1794                         nloop++;
1795         } while (err == -EADDRINUSE && nloop != 2);
1796
1797         if (myaddr.ss_family == AF_INET)
1798                 dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1799                                 &((struct sockaddr_in *)&myaddr)->sin_addr,
1800                                 port, err ? "failed" : "ok", err);
1801         else
1802                 dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1803                                 &((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1804                                 port, err ? "failed" : "ok", err);
1805         return err;
1806 }
1807
1808 /*
1809  * We don't support autobind on AF_LOCAL sockets
1810  */
1811 static void xs_local_rpcbind(struct rpc_task *task)
1812 {
1813         xprt_set_bound(task->tk_xprt);
1814 }
1815
1816 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1817 {
1818 }
1819
1820 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1821 static struct lock_class_key xs_key[2];
1822 static struct lock_class_key xs_slock_key[2];
1823
1824 static inline void xs_reclassify_socketu(struct socket *sock)
1825 {
1826         struct sock *sk = sock->sk;
1827
1828         sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1829                 &xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1830 }
1831
1832 static inline void xs_reclassify_socket4(struct socket *sock)
1833 {
1834         struct sock *sk = sock->sk;
1835
1836         sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1837                 &xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1838 }
1839
1840 static inline void xs_reclassify_socket6(struct socket *sock)
1841 {
1842         struct sock *sk = sock->sk;
1843
1844         sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1845                 &xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1846 }
1847
1848 static inline void xs_reclassify_socket(int family, struct socket *sock)
1849 {
1850         if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1851                 return;
1852
1853         switch (family) {
1854         case AF_LOCAL:
1855                 xs_reclassify_socketu(sock);
1856                 break;
1857         case AF_INET:
1858                 xs_reclassify_socket4(sock);
1859                 break;
1860         case AF_INET6:
1861                 xs_reclassify_socket6(sock);
1862                 break;
1863         }
1864 }
1865 #else
1866 static inline void xs_reclassify_socket(int family, struct socket *sock)
1867 {
1868 }
1869 #endif
1870
1871 static void xs_dummy_setup_socket(struct work_struct *work)
1872 {
1873 }
1874
1875 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1876                 struct sock_xprt *transport, int family, int type,
1877                 int protocol, bool reuseport)
1878 {
1879         struct file *filp;
1880         struct socket *sock;
1881         int err;
1882
1883         err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1884         if (err < 0) {
1885                 dprintk("RPC:       can't create %d transport socket (%d).\n",
1886                                 protocol, -err);
1887                 goto out;
1888         }
1889         xs_reclassify_socket(family, sock);
1890
1891         if (reuseport)
1892                 xs_sock_set_reuseport(sock);
1893
1894         err = xs_bind(transport, sock);
1895         if (err) {
1896                 sock_release(sock);
1897                 goto out;
1898         }
1899
1900         filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1901         if (IS_ERR(filp))
1902                 return ERR_CAST(filp);
1903         transport->file = filp;
1904
1905         return sock;
1906 out:
1907         return ERR_PTR(err);
1908 }
1909
1910 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1911                                       struct socket *sock)
1912 {
1913         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1914                                                                         xprt);
1915
1916         if (!transport->inet) {
1917                 struct sock *sk = sock->sk;
1918
1919                 write_lock_bh(&sk->sk_callback_lock);
1920
1921                 xs_save_old_callbacks(transport, sk);
1922
1923                 sk->sk_user_data = xprt;
1924                 sk->sk_data_ready = xs_data_ready;
1925                 sk->sk_write_space = xs_udp_write_space;
1926                 sock_set_flag(sk, SOCK_FASYNC);
1927                 sk->sk_error_report = xs_error_report;
1928
1929                 xprt_clear_connected(xprt);
1930
1931                 /* Reset to new socket */
1932                 transport->sock = sock;
1933                 transport->inet = sk;
1934
1935                 write_unlock_bh(&sk->sk_callback_lock);
1936         }
1937
1938         xs_stream_start_connect(transport);
1939
1940         return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1941 }
1942
1943 /**
1944  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1945  * @transport: socket transport to connect
1946  */
1947 static int xs_local_setup_socket(struct sock_xprt *transport)
1948 {
1949         struct rpc_xprt *xprt = &transport->xprt;
1950         struct file *filp;
1951         struct socket *sock;
1952         int status = -EIO;
1953
1954         status = __sock_create(xprt->xprt_net, AF_LOCAL,
1955                                         SOCK_STREAM, 0, &sock, 1);
1956         if (status < 0) {
1957                 dprintk("RPC:       can't create AF_LOCAL "
1958                         "transport socket (%d).\n", -status);
1959                 goto out;
1960         }
1961         xs_reclassify_socket(AF_LOCAL, sock);
1962
1963         filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1964         if (IS_ERR(filp)) {
1965                 status = PTR_ERR(filp);
1966                 goto out;
1967         }
1968         transport->file = filp;
1969
1970         dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1971                         xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1972
1973         status = xs_local_finish_connecting(xprt, sock);
1974         trace_rpc_socket_connect(xprt, sock, status);
1975         switch (status) {
1976         case 0:
1977                 dprintk("RPC:       xprt %p connected to %s\n",
1978                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1979                 xprt->stat.connect_count++;
1980                 xprt->stat.connect_time += (long)jiffies -
1981                                            xprt->stat.connect_start;
1982                 xprt_set_connected(xprt);
1983         case -ENOBUFS:
1984                 break;
1985         case -ENOENT:
1986                 dprintk("RPC:       xprt %p: socket %s does not exist\n",
1987                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1988                 break;
1989         case -ECONNREFUSED:
1990                 dprintk("RPC:       xprt %p: connection refused for %s\n",
1991                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1992                 break;
1993         default:
1994                 printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1995                                 __func__, -status,
1996                                 xprt->address_strings[RPC_DISPLAY_ADDR]);
1997         }
1998
1999 out:
2000         xprt_clear_connecting(xprt);
2001         xprt_wake_pending_tasks(xprt, status);
2002         return status;
2003 }
2004
2005 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2006 {
2007         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2008         int ret;
2009
2010          if (RPC_IS_ASYNC(task)) {
2011                 /*
2012                  * We want the AF_LOCAL connect to be resolved in the
2013                  * filesystem namespace of the process making the rpc
2014                  * call.  Thus we connect synchronously.
2015                  *
2016                  * If we want to support asynchronous AF_LOCAL calls,
2017                  * we'll need to figure out how to pass a namespace to
2018                  * connect.
2019                  */
2020                 rpc_exit(task, -ENOTCONN);
2021                 return;
2022         }
2023         ret = xs_local_setup_socket(transport);
2024         if (ret && !RPC_IS_SOFTCONN(task))
2025                 msleep_interruptible(15000);
2026 }
2027
2028 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2029 /*
2030  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
2031  * know that we have exclusive access to the socket), to guard against
2032  * races with xs_reset_transport.
2033  */
2034 static void xs_set_memalloc(struct rpc_xprt *xprt)
2035 {
2036         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2037                         xprt);
2038
2039         /*
2040          * If there's no sock, then we have nothing to set. The
2041          * reconnecting process will get it for us.
2042          */
2043         if (!transport->inet)
2044                 return;
2045         if (atomic_read(&xprt->swapper))
2046                 sk_set_memalloc(transport->inet);
2047 }
2048
2049 /**
2050  * xs_enable_swap - Tag this transport as being used for swap.
2051  * @xprt: transport to tag
2052  *
2053  * Take a reference to this transport on behalf of the rpc_clnt, and
2054  * optionally mark it for swapping if it wasn't already.
2055  */
2056 static int
2057 xs_enable_swap(struct rpc_xprt *xprt)
2058 {
2059         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2060
2061         if (atomic_inc_return(&xprt->swapper) != 1)
2062                 return 0;
2063         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2064                 return -ERESTARTSYS;
2065         if (xs->inet)
2066                 sk_set_memalloc(xs->inet);
2067         xprt_release_xprt(xprt, NULL);
2068         return 0;
2069 }
2070
2071 /**
2072  * xs_disable_swap - Untag this transport as being used for swap.
2073  * @xprt: transport to tag
2074  *
2075  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2076  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2077  */
2078 static void
2079 xs_disable_swap(struct rpc_xprt *xprt)
2080 {
2081         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2082
2083         if (!atomic_dec_and_test(&xprt->swapper))
2084                 return;
2085         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2086                 return;
2087         if (xs->inet)
2088                 sk_clear_memalloc(xs->inet);
2089         xprt_release_xprt(xprt, NULL);
2090 }
2091 #else
2092 static void xs_set_memalloc(struct rpc_xprt *xprt)
2093 {
2094 }
2095
2096 static int
2097 xs_enable_swap(struct rpc_xprt *xprt)
2098 {
2099         return -EINVAL;
2100 }
2101
2102 static void
2103 xs_disable_swap(struct rpc_xprt *xprt)
2104 {
2105 }
2106 #endif
2107
2108 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2109 {
2110         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2111
2112         if (!transport->inet) {
2113                 struct sock *sk = sock->sk;
2114
2115                 write_lock_bh(&sk->sk_callback_lock);
2116
2117                 xs_save_old_callbacks(transport, sk);
2118
2119                 sk->sk_user_data = xprt;
2120                 sk->sk_data_ready = xs_data_ready;
2121                 sk->sk_write_space = xs_udp_write_space;
2122                 sock_set_flag(sk, SOCK_FASYNC);
2123
2124                 xprt_set_connected(xprt);
2125
2126                 /* Reset to new socket */
2127                 transport->sock = sock;
2128                 transport->inet = sk;
2129
2130                 xs_set_memalloc(xprt);
2131
2132                 write_unlock_bh(&sk->sk_callback_lock);
2133         }
2134         xs_udp_do_set_buffer_size(xprt);
2135
2136         xprt->stat.connect_start = jiffies;
2137 }
2138
2139 static void xs_udp_setup_socket(struct work_struct *work)
2140 {
2141         struct sock_xprt *transport =
2142                 container_of(work, struct sock_xprt, connect_worker.work);
2143         struct rpc_xprt *xprt = &transport->xprt;
2144         struct socket *sock;
2145         int status = -EIO;
2146
2147         sock = xs_create_sock(xprt, transport,
2148                         xs_addr(xprt)->sa_family, SOCK_DGRAM,
2149                         IPPROTO_UDP, false);
2150         if (IS_ERR(sock))
2151                 goto out;
2152
2153         dprintk("RPC:       worker connecting xprt %p via %s to "
2154                                 "%s (port %s)\n", xprt,
2155                         xprt->address_strings[RPC_DISPLAY_PROTO],
2156                         xprt->address_strings[RPC_DISPLAY_ADDR],
2157                         xprt->address_strings[RPC_DISPLAY_PORT]);
2158
2159         xs_udp_finish_connecting(xprt, sock);
2160         trace_rpc_socket_connect(xprt, sock, 0);
2161         status = 0;
2162 out:
2163         xprt_clear_connecting(xprt);
2164         xprt_unlock_connect(xprt, transport);
2165         xprt_wake_pending_tasks(xprt, status);
2166 }
2167
2168 /**
2169  * xs_tcp_shutdown - gracefully shut down a TCP socket
2170  * @xprt: transport
2171  *
2172  * Initiates a graceful shutdown of the TCP socket by calling the
2173  * equivalent of shutdown(SHUT_RDWR);
2174  */
2175 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2176 {
2177         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2178         struct socket *sock = transport->sock;
2179         int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2180
2181         if (sock == NULL)
2182                 return;
2183         switch (skst) {
2184         default:
2185                 kernel_sock_shutdown(sock, SHUT_RDWR);
2186                 trace_rpc_socket_shutdown(xprt, sock);
2187                 break;
2188         case TCP_CLOSE:
2189         case TCP_TIME_WAIT:
2190                 xs_reset_transport(transport);
2191         }
2192 }
2193
2194 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2195                 struct socket *sock)
2196 {
2197         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2198         unsigned int keepidle;
2199         unsigned int keepcnt;
2200         unsigned int opt_on = 1;
2201         unsigned int timeo;
2202
2203         spin_lock_bh(&xprt->transport_lock);
2204         keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2205         keepcnt = xprt->timeout->to_retries + 1;
2206         timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2207                 (xprt->timeout->to_retries + 1);
2208         clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2209         spin_unlock_bh(&xprt->transport_lock);
2210
2211         /* TCP Keepalive options */
2212         kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2213                         (char *)&opt_on, sizeof(opt_on));
2214         kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2215                         (char *)&keepidle, sizeof(keepidle));
2216         kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2217                         (char *)&keepidle, sizeof(keepidle));
2218         kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2219                         (char *)&keepcnt, sizeof(keepcnt));
2220
2221         /* TCP user timeout (see RFC5482) */
2222         kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
2223                         (char *)&timeo, sizeof(timeo));
2224 }
2225
2226 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2227                 unsigned long connect_timeout,
2228                 unsigned long reconnect_timeout)
2229 {
2230         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2231         struct rpc_timeout to;
2232         unsigned long initval;
2233
2234         spin_lock_bh(&xprt->transport_lock);
2235         if (reconnect_timeout < xprt->max_reconnect_timeout)
2236                 xprt->max_reconnect_timeout = reconnect_timeout;
2237         if (connect_timeout < xprt->connect_timeout) {
2238                 memcpy(&to, xprt->timeout, sizeof(to));
2239                 initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2240                 /* Arbitrary lower limit */
2241                 if (initval <  XS_TCP_INIT_REEST_TO << 1)
2242                         initval = XS_TCP_INIT_REEST_TO << 1;
2243                 to.to_initval = initval;
2244                 to.to_maxval = initval;
2245                 memcpy(&transport->tcp_timeout, &to,
2246                                 sizeof(transport->tcp_timeout));
2247                 xprt->timeout = &transport->tcp_timeout;
2248                 xprt->connect_timeout = connect_timeout;
2249         }
2250         set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2251         spin_unlock_bh(&xprt->transport_lock);
2252 }
2253
2254 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2255 {
2256         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2257         int ret = -ENOTCONN;
2258
2259         if (!transport->inet) {
2260                 struct sock *sk = sock->sk;
2261                 unsigned int addr_pref = IPV6_PREFER_SRC_PUBLIC;
2262
2263                 /* Avoid temporary address, they are bad for long-lived
2264                  * connections such as NFS mounts.
2265                  * RFC4941, section 3.6 suggests that:
2266                  *    Individual applications, which have specific
2267                  *    knowledge about the normal duration of connections,
2268                  *    MAY override this as appropriate.
2269                  */
2270                 kernel_setsockopt(sock, SOL_IPV6, IPV6_ADDR_PREFERENCES,
2271                                 (char *)&addr_pref, sizeof(addr_pref));
2272
2273                 xs_tcp_set_socket_timeouts(xprt, sock);
2274
2275                 write_lock_bh(&sk->sk_callback_lock);
2276
2277                 xs_save_old_callbacks(transport, sk);
2278
2279                 sk->sk_user_data = xprt;
2280                 sk->sk_data_ready = xs_data_ready;
2281                 sk->sk_state_change = xs_tcp_state_change;
2282                 sk->sk_write_space = xs_tcp_write_space;
2283                 sock_set_flag(sk, SOCK_FASYNC);
2284                 sk->sk_error_report = xs_error_report;
2285
2286                 /* socket options */
2287                 sock_reset_flag(sk, SOCK_LINGER);
2288                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2289
2290                 xprt_clear_connected(xprt);
2291
2292                 /* Reset to new socket */
2293                 transport->sock = sock;
2294                 transport->inet = sk;
2295
2296                 write_unlock_bh(&sk->sk_callback_lock);
2297         }
2298
2299         if (!xprt_bound(xprt))
2300                 goto out;
2301
2302         xs_set_memalloc(xprt);
2303
2304         xs_stream_start_connect(transport);
2305
2306         /* Tell the socket layer to start connecting... */
2307         set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2308         ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2309         switch (ret) {
2310         case 0:
2311                 xs_set_srcport(transport, sock);
2312                 /* fall through */
2313         case -EINPROGRESS:
2314                 /* SYN_SENT! */
2315                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2316                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2317                 break;
2318         case -EADDRNOTAVAIL:
2319                 /* Source port number is unavailable. Try a new one! */
2320                 transport->srcport = 0;
2321         }
2322 out:
2323         return ret;
2324 }
2325
2326 /**
2327  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2328  * @work: queued work item
2329  *
2330  * Invoked by a work queue tasklet.
2331  */
2332 static void xs_tcp_setup_socket(struct work_struct *work)
2333 {
2334         struct sock_xprt *transport =
2335                 container_of(work, struct sock_xprt, connect_worker.work);
2336         struct socket *sock = transport->sock;
2337         struct rpc_xprt *xprt = &transport->xprt;
2338         int status = -EIO;
2339
2340         if (!sock) {
2341                 sock = xs_create_sock(xprt, transport,
2342                                 xs_addr(xprt)->sa_family, SOCK_STREAM,
2343                                 IPPROTO_TCP, true);
2344                 if (IS_ERR(sock)) {
2345                         status = PTR_ERR(sock);
2346                         goto out;
2347                 }
2348         }
2349
2350         dprintk("RPC:       worker connecting xprt %p via %s to "
2351                                 "%s (port %s)\n", xprt,
2352                         xprt->address_strings[RPC_DISPLAY_PROTO],
2353                         xprt->address_strings[RPC_DISPLAY_ADDR],
2354                         xprt->address_strings[RPC_DISPLAY_PORT]);
2355
2356         status = xs_tcp_finish_connecting(xprt, sock);
2357         trace_rpc_socket_connect(xprt, sock, status);
2358         dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2359                         xprt, -status, xprt_connected(xprt),
2360                         sock->sk->sk_state);
2361         switch (status) {
2362         default:
2363                 printk("%s: connect returned unhandled error %d\n",
2364                         __func__, status);
2365                 /* fall through */
2366         case -EADDRNOTAVAIL:
2367                 /* We're probably in TIME_WAIT. Get rid of existing socket,
2368                  * and retry
2369                  */
2370                 xs_tcp_force_close(xprt);
2371                 break;
2372         case 0:
2373         case -EINPROGRESS:
2374         case -EALREADY:
2375                 xprt_unlock_connect(xprt, transport);
2376                 return;
2377         case -EINVAL:
2378                 /* Happens, for instance, if the user specified a link
2379                  * local IPv6 address without a scope-id.
2380                  */
2381         case -ECONNREFUSED:
2382         case -ECONNRESET:
2383         case -ENETDOWN:
2384         case -ENETUNREACH:
2385         case -EHOSTUNREACH:
2386         case -EADDRINUSE:
2387         case -ENOBUFS:
2388                 /*
2389                  * xs_tcp_force_close() wakes tasks with -EIO.
2390                  * We need to wake them first to ensure the
2391                  * correct error code.
2392                  */
2393                 xprt_wake_pending_tasks(xprt, status);
2394                 xs_tcp_force_close(xprt);
2395                 goto out;
2396         }
2397         status = -EAGAIN;
2398 out:
2399         xprt_clear_connecting(xprt);
2400         xprt_unlock_connect(xprt, transport);
2401         xprt_wake_pending_tasks(xprt, status);
2402 }
2403
2404 static unsigned long xs_reconnect_delay(const struct rpc_xprt *xprt)
2405 {
2406         unsigned long start, now = jiffies;
2407
2408         start = xprt->stat.connect_start + xprt->reestablish_timeout;
2409         if (time_after(start, now))
2410                 return start - now;
2411         return 0;
2412 }
2413
2414 static void xs_reconnect_backoff(struct rpc_xprt *xprt)
2415 {
2416         xprt->reestablish_timeout <<= 1;
2417         if (xprt->reestablish_timeout > xprt->max_reconnect_timeout)
2418                 xprt->reestablish_timeout = xprt->max_reconnect_timeout;
2419         if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2420                 xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2421 }
2422
2423 /**
2424  * xs_connect - connect a socket to a remote endpoint
2425  * @xprt: pointer to transport structure
2426  * @task: address of RPC task that manages state of connect request
2427  *
2428  * TCP: If the remote end dropped the connection, delay reconnecting.
2429  *
2430  * UDP socket connects are synchronous, but we use a work queue anyway
2431  * to guarantee that even unprivileged user processes can set up a
2432  * socket on a privileged port.
2433  *
2434  * If a UDP socket connect fails, the delay behavior here prevents
2435  * retry floods (hard mounts).
2436  */
2437 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2438 {
2439         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2440         unsigned long delay = 0;
2441
2442         WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2443
2444         if (transport->sock != NULL) {
2445                 dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2446                                 "seconds\n",
2447                                 xprt, xprt->reestablish_timeout / HZ);
2448
2449                 /* Start by resetting any existing state */
2450                 xs_reset_transport(transport);
2451
2452                 delay = xs_reconnect_delay(xprt);
2453                 xs_reconnect_backoff(xprt);
2454
2455         } else
2456                 dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2457
2458         queue_delayed_work(xprtiod_workqueue,
2459                         &transport->connect_worker,
2460                         delay);
2461 }
2462
2463 /**
2464  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2465  * @xprt: rpc_xprt struct containing statistics
2466  * @seq: output file
2467  *
2468  */
2469 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2470 {
2471         long idle_time = 0;
2472
2473         if (xprt_connected(xprt))
2474                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2475
2476         seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2477                         "%llu %llu %lu %llu %llu\n",
2478                         xprt->stat.bind_count,
2479                         xprt->stat.connect_count,
2480                         xprt->stat.connect_time / HZ,
2481                         idle_time,
2482                         xprt->stat.sends,
2483                         xprt->stat.recvs,
2484                         xprt->stat.bad_xids,
2485                         xprt->stat.req_u,
2486                         xprt->stat.bklog_u,
2487                         xprt->stat.max_slots,
2488                         xprt->stat.sending_u,
2489                         xprt->stat.pending_u);
2490 }
2491
2492 /**
2493  * xs_udp_print_stats - display UDP socket-specifc stats
2494  * @xprt: rpc_xprt struct containing statistics
2495  * @seq: output file
2496  *
2497  */
2498 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2499 {
2500         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2501
2502         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2503                         "%lu %llu %llu\n",
2504                         transport->srcport,
2505                         xprt->stat.bind_count,
2506                         xprt->stat.sends,
2507                         xprt->stat.recvs,
2508                         xprt->stat.bad_xids,
2509                         xprt->stat.req_u,
2510                         xprt->stat.bklog_u,
2511                         xprt->stat.max_slots,
2512                         xprt->stat.sending_u,
2513                         xprt->stat.pending_u);
2514 }
2515
2516 /**
2517  * xs_tcp_print_stats - display TCP socket-specifc stats
2518  * @xprt: rpc_xprt struct containing statistics
2519  * @seq: output file
2520  *
2521  */
2522 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2523 {
2524         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2525         long idle_time = 0;
2526
2527         if (xprt_connected(xprt))
2528                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2529
2530         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2531                         "%llu %llu %lu %llu %llu\n",
2532                         transport->srcport,
2533                         xprt->stat.bind_count,
2534                         xprt->stat.connect_count,
2535                         xprt->stat.connect_time / HZ,
2536                         idle_time,
2537                         xprt->stat.sends,
2538                         xprt->stat.recvs,
2539                         xprt->stat.bad_xids,
2540                         xprt->stat.req_u,
2541                         xprt->stat.bklog_u,
2542                         xprt->stat.max_slots,
2543                         xprt->stat.sending_u,
2544                         xprt->stat.pending_u);
2545 }
2546
2547 /*
2548  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2549  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2550  * to use the server side send routines.
2551  */
2552 static int bc_malloc(struct rpc_task *task)
2553 {
2554         struct rpc_rqst *rqst = task->tk_rqstp;
2555         size_t size = rqst->rq_callsize;
2556         struct page *page;
2557         struct rpc_buffer *buf;
2558
2559         if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2560                 WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2561                           size);
2562                 return -EINVAL;
2563         }
2564
2565         page = alloc_page(GFP_KERNEL);
2566         if (!page)
2567                 return -ENOMEM;
2568
2569         buf = page_address(page);
2570         buf->len = PAGE_SIZE;
2571
2572         rqst->rq_buffer = buf->data;
2573         rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2574         return 0;
2575 }
2576
2577 /*
2578  * Free the space allocated in the bc_alloc routine
2579  */
2580 static void bc_free(struct rpc_task *task)
2581 {
2582         void *buffer = task->tk_rqstp->rq_buffer;
2583         struct rpc_buffer *buf;
2584
2585         buf = container_of(buffer, struct rpc_buffer, data);
2586         free_page((unsigned long)buf);
2587 }
2588
2589 /*
2590  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2591  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2592  */
2593 static int bc_sendto(struct rpc_rqst *req)
2594 {
2595         int len;
2596         struct xdr_buf *xbufp = &req->rq_snd_buf;
2597         struct sock_xprt *transport =
2598                         container_of(req->rq_xprt, struct sock_xprt, xprt);
2599         unsigned long headoff;
2600         unsigned long tailoff;
2601         struct page *tailpage;
2602         struct msghdr msg = {
2603                 .msg_flags      = MSG_MORE
2604         };
2605         rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
2606                                          (u32)xbufp->len);
2607         struct kvec iov = {
2608                 .iov_base       = &marker,
2609                 .iov_len        = sizeof(marker),
2610         };
2611
2612         len = kernel_sendmsg(transport->sock, &msg, &iov, 1, iov.iov_len);
2613         if (len != iov.iov_len)
2614                 return -EAGAIN;
2615
2616         tailpage = NULL;
2617         if (xbufp->tail[0].iov_len)
2618                 tailpage = virt_to_page(xbufp->tail[0].iov_base);
2619         tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2620         headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2621         len = svc_send_common(transport->sock, xbufp,
2622                               virt_to_page(xbufp->head[0].iov_base), headoff,
2623                               tailpage, tailoff);
2624         if (len != xbufp->len)
2625                 return -EAGAIN;
2626         return len;
2627 }
2628
2629 /*
2630  * The send routine. Borrows from svc_send
2631  */
2632 static int bc_send_request(struct rpc_rqst *req)
2633 {
2634         struct svc_xprt *xprt;
2635         int len;
2636
2637         dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2638         /*
2639          * Get the server socket associated with this callback xprt
2640          */
2641         xprt = req->rq_xprt->bc_xprt;
2642
2643         /*
2644          * Grab the mutex to serialize data as the connection is shared
2645          * with the fore channel
2646          */
2647         mutex_lock(&xprt->xpt_mutex);
2648         if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2649                 len = -ENOTCONN;
2650         else
2651                 len = bc_sendto(req);
2652         mutex_unlock(&xprt->xpt_mutex);
2653
2654         if (len > 0)
2655                 len = 0;
2656
2657         return len;
2658 }
2659
2660 /*
2661  * The close routine. Since this is client initiated, we do nothing
2662  */
2663
2664 static void bc_close(struct rpc_xprt *xprt)
2665 {
2666 }
2667
2668 /*
2669  * The xprt destroy routine. Again, because this connection is client
2670  * initiated, we do nothing
2671  */
2672
2673 static void bc_destroy(struct rpc_xprt *xprt)
2674 {
2675         dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2676
2677         xs_xprt_free(xprt);
2678         module_put(THIS_MODULE);
2679 }
2680
2681 static const struct rpc_xprt_ops xs_local_ops = {
2682         .reserve_xprt           = xprt_reserve_xprt,
2683         .release_xprt           = xprt_release_xprt,
2684         .alloc_slot             = xprt_alloc_slot,
2685         .free_slot              = xprt_free_slot,
2686         .rpcbind                = xs_local_rpcbind,
2687         .set_port               = xs_local_set_port,
2688         .connect                = xs_local_connect,
2689         .buf_alloc              = rpc_malloc,
2690         .buf_free               = rpc_free,
2691         .prepare_request        = xs_stream_prepare_request,
2692         .send_request           = xs_local_send_request,
2693         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2694         .close                  = xs_close,
2695         .destroy                = xs_destroy,
2696         .print_stats            = xs_local_print_stats,
2697         .enable_swap            = xs_enable_swap,
2698         .disable_swap           = xs_disable_swap,
2699 };
2700
2701 static const struct rpc_xprt_ops xs_udp_ops = {
2702         .set_buffer_size        = xs_udp_set_buffer_size,
2703         .reserve_xprt           = xprt_reserve_xprt_cong,
2704         .release_xprt           = xprt_release_xprt_cong,
2705         .alloc_slot             = xprt_alloc_slot,
2706         .free_slot              = xprt_free_slot,
2707         .rpcbind                = rpcb_getport_async,
2708         .set_port               = xs_set_port,
2709         .connect                = xs_connect,
2710         .buf_alloc              = rpc_malloc,
2711         .buf_free               = rpc_free,
2712         .send_request           = xs_udp_send_request,
2713         .set_retrans_timeout    = xprt_set_retrans_timeout_rtt,
2714         .timer                  = xs_udp_timer,
2715         .release_request        = xprt_release_rqst_cong,
2716         .close                  = xs_close,
2717         .destroy                = xs_destroy,
2718         .print_stats            = xs_udp_print_stats,
2719         .enable_swap            = xs_enable_swap,
2720         .disable_swap           = xs_disable_swap,
2721         .inject_disconnect      = xs_inject_disconnect,
2722 };
2723
2724 static const struct rpc_xprt_ops xs_tcp_ops = {
2725         .reserve_xprt           = xprt_reserve_xprt,
2726         .release_xprt           = xprt_release_xprt,
2727         .alloc_slot             = xprt_alloc_slot,
2728         .free_slot              = xprt_free_slot,
2729         .rpcbind                = rpcb_getport_async,
2730         .set_port               = xs_set_port,
2731         .connect                = xs_connect,
2732         .buf_alloc              = rpc_malloc,
2733         .buf_free               = rpc_free,
2734         .prepare_request        = xs_stream_prepare_request,
2735         .send_request           = xs_tcp_send_request,
2736         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2737         .close                  = xs_tcp_shutdown,
2738         .destroy                = xs_destroy,
2739         .set_connect_timeout    = xs_tcp_set_connect_timeout,
2740         .print_stats            = xs_tcp_print_stats,
2741         .enable_swap            = xs_enable_swap,
2742         .disable_swap           = xs_disable_swap,
2743         .inject_disconnect      = xs_inject_disconnect,
2744 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2745         .bc_setup               = xprt_setup_bc,
2746         .bc_maxpayload          = xs_tcp_bc_maxpayload,
2747         .bc_free_rqst           = xprt_free_bc_rqst,
2748         .bc_destroy             = xprt_destroy_bc,
2749 #endif
2750 };
2751
2752 /*
2753  * The rpc_xprt_ops for the server backchannel
2754  */
2755
2756 static const struct rpc_xprt_ops bc_tcp_ops = {
2757         .reserve_xprt           = xprt_reserve_xprt,
2758         .release_xprt           = xprt_release_xprt,
2759         .alloc_slot             = xprt_alloc_slot,
2760         .free_slot              = xprt_free_slot,
2761         .buf_alloc              = bc_malloc,
2762         .buf_free               = bc_free,
2763         .send_request           = bc_send_request,
2764         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2765         .close                  = bc_close,
2766         .destroy                = bc_destroy,
2767         .print_stats            = xs_tcp_print_stats,
2768         .enable_swap            = xs_enable_swap,
2769         .disable_swap           = xs_disable_swap,
2770         .inject_disconnect      = xs_inject_disconnect,
2771 };
2772
2773 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2774 {
2775         static const struct sockaddr_in sin = {
2776                 .sin_family             = AF_INET,
2777                 .sin_addr.s_addr        = htonl(INADDR_ANY),
2778         };
2779         static const struct sockaddr_in6 sin6 = {
2780                 .sin6_family            = AF_INET6,
2781                 .sin6_addr              = IN6ADDR_ANY_INIT,
2782         };
2783
2784         switch (family) {
2785         case AF_LOCAL:
2786                 break;
2787         case AF_INET:
2788                 memcpy(sap, &sin, sizeof(sin));
2789                 break;
2790         case AF_INET6:
2791                 memcpy(sap, &sin6, sizeof(sin6));
2792                 break;
2793         default:
2794                 dprintk("RPC:       %s: Bad address family\n", __func__);
2795                 return -EAFNOSUPPORT;
2796         }
2797         return 0;
2798 }
2799
2800 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2801                                       unsigned int slot_table_size,
2802                                       unsigned int max_slot_table_size)
2803 {
2804         struct rpc_xprt *xprt;
2805         struct sock_xprt *new;
2806
2807         if (args->addrlen > sizeof(xprt->addr)) {
2808                 dprintk("RPC:       xs_setup_xprt: address too large\n");
2809                 return ERR_PTR(-EBADF);
2810         }
2811
2812         xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2813                         max_slot_table_size);
2814         if (xprt == NULL) {
2815                 dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2816                                 "rpc_xprt\n");
2817                 return ERR_PTR(-ENOMEM);
2818         }
2819
2820         new = container_of(xprt, struct sock_xprt, xprt);
2821         mutex_init(&new->recv_mutex);
2822         memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2823         xprt->addrlen = args->addrlen;
2824         if (args->srcaddr)
2825                 memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2826         else {
2827                 int err;
2828                 err = xs_init_anyaddr(args->dstaddr->sa_family,
2829                                         (struct sockaddr *)&new->srcaddr);
2830                 if (err != 0) {
2831                         xprt_free(xprt);
2832                         return ERR_PTR(err);
2833                 }
2834         }
2835
2836         return xprt;
2837 }
2838
2839 static const struct rpc_timeout xs_local_default_timeout = {
2840         .to_initval = 10 * HZ,
2841         .to_maxval = 10 * HZ,
2842         .to_retries = 2,
2843 };
2844
2845 /**
2846  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2847  * @args: rpc transport creation arguments
2848  *
2849  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2850  */
2851 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2852 {
2853         struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2854         struct sock_xprt *transport;
2855         struct rpc_xprt *xprt;
2856         struct rpc_xprt *ret;
2857
2858         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2859                         xprt_max_tcp_slot_table_entries);
2860         if (IS_ERR(xprt))
2861                 return xprt;
2862         transport = container_of(xprt, struct sock_xprt, xprt);
2863
2864         xprt->prot = 0;
2865         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2866
2867         xprt->bind_timeout = XS_BIND_TO;
2868         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2869         xprt->idle_timeout = XS_IDLE_DISC_TO;
2870
2871         xprt->ops = &xs_local_ops;
2872         xprt->timeout = &xs_local_default_timeout;
2873
2874         INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2875         INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2876
2877         switch (sun->sun_family) {
2878         case AF_LOCAL:
2879                 if (sun->sun_path[0] != '/') {
2880                         dprintk("RPC:       bad AF_LOCAL address: %s\n",
2881                                         sun->sun_path);
2882                         ret = ERR_PTR(-EINVAL);
2883                         goto out_err;
2884                 }
2885                 xprt_set_bound(xprt);
2886                 xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2887                 ret = ERR_PTR(xs_local_setup_socket(transport));
2888                 if (ret)
2889                         goto out_err;
2890                 break;
2891         default:
2892                 ret = ERR_PTR(-EAFNOSUPPORT);
2893                 goto out_err;
2894         }
2895
2896         dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2897                         xprt->address_strings[RPC_DISPLAY_ADDR]);
2898
2899         if (try_module_get(THIS_MODULE))
2900                 return xprt;
2901         ret = ERR_PTR(-EINVAL);
2902 out_err:
2903         xs_xprt_free(xprt);
2904         return ret;
2905 }
2906
2907 static const struct rpc_timeout xs_udp_default_timeout = {
2908         .to_initval = 5 * HZ,
2909         .to_maxval = 30 * HZ,
2910         .to_increment = 5 * HZ,
2911         .to_retries = 5,
2912 };
2913
2914 /**
2915  * xs_setup_udp - Set up transport to use a UDP socket
2916  * @args: rpc transport creation arguments
2917  *
2918  */
2919 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2920 {
2921         struct sockaddr *addr = args->dstaddr;
2922         struct rpc_xprt *xprt;
2923         struct sock_xprt *transport;
2924         struct rpc_xprt *ret;
2925
2926         xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2927                         xprt_udp_slot_table_entries);
2928         if (IS_ERR(xprt))
2929                 return xprt;
2930         transport = container_of(xprt, struct sock_xprt, xprt);
2931
2932         xprt->prot = IPPROTO_UDP;
2933         /* XXX: header size can vary due to auth type, IPv6, etc. */
2934         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2935
2936         xprt->bind_timeout = XS_BIND_TO;
2937         xprt->reestablish_timeout = XS_UDP_REEST_TO;
2938         xprt->idle_timeout = XS_IDLE_DISC_TO;
2939
2940         xprt->ops = &xs_udp_ops;
2941
2942         xprt->timeout = &xs_udp_default_timeout;
2943
2944         INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2945         INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2946
2947         switch (addr->sa_family) {
2948         case AF_INET:
2949                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2950                         xprt_set_bound(xprt);
2951
2952                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2953                 break;
2954         case AF_INET6:
2955                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2956                         xprt_set_bound(xprt);
2957
2958                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2959                 break;
2960         default:
2961                 ret = ERR_PTR(-EAFNOSUPPORT);
2962                 goto out_err;
2963         }
2964
2965         if (xprt_bound(xprt))
2966                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2967                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2968                                 xprt->address_strings[RPC_DISPLAY_PORT],
2969                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2970         else
2971                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2972                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2973                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2974
2975         if (try_module_get(THIS_MODULE))
2976                 return xprt;
2977         ret = ERR_PTR(-EINVAL);
2978 out_err:
2979         xs_xprt_free(xprt);
2980         return ret;
2981 }
2982
2983 static const struct rpc_timeout xs_tcp_default_timeout = {
2984         .to_initval = 60 * HZ,
2985         .to_maxval = 60 * HZ,
2986         .to_retries = 2,
2987 };
2988
2989 /**
2990  * xs_setup_tcp - Set up transport to use a TCP socket
2991  * @args: rpc transport creation arguments
2992  *
2993  */
2994 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2995 {
2996         struct sockaddr *addr = args->dstaddr;
2997         struct rpc_xprt *xprt;
2998         struct sock_xprt *transport;
2999         struct rpc_xprt *ret;
3000         unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
3001
3002         if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
3003                 max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
3004
3005         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3006                         max_slot_table_size);
3007         if (IS_ERR(xprt))
3008                 return xprt;
3009         transport = container_of(xprt, struct sock_xprt, xprt);
3010
3011         xprt->prot = IPPROTO_TCP;
3012         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3013
3014         xprt->bind_timeout = XS_BIND_TO;
3015         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
3016         xprt->idle_timeout = XS_IDLE_DISC_TO;
3017
3018         xprt->ops = &xs_tcp_ops;
3019         xprt->timeout = &xs_tcp_default_timeout;
3020
3021         xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
3022         xprt->connect_timeout = xprt->timeout->to_initval *
3023                 (xprt->timeout->to_retries + 1);
3024
3025         INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
3026         INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
3027
3028         switch (addr->sa_family) {
3029         case AF_INET:
3030                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
3031                         xprt_set_bound(xprt);
3032
3033                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
3034                 break;
3035         case AF_INET6:
3036                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
3037                         xprt_set_bound(xprt);
3038
3039                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
3040                 break;
3041         default:
3042                 ret = ERR_PTR(-EAFNOSUPPORT);
3043                 goto out_err;
3044         }
3045
3046         if (xprt_bound(xprt))
3047                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3048                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3049                                 xprt->address_strings[RPC_DISPLAY_PORT],
3050                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3051         else
3052                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
3053                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3054                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3055
3056         if (try_module_get(THIS_MODULE))
3057                 return xprt;
3058         ret = ERR_PTR(-EINVAL);
3059 out_err:
3060         xs_xprt_free(xprt);
3061         return ret;
3062 }
3063
3064 /**
3065  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
3066  * @args: rpc transport creation arguments
3067  *
3068  */
3069 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3070 {
3071         struct sockaddr *addr = args->dstaddr;
3072         struct rpc_xprt *xprt;
3073         struct sock_xprt *transport;
3074         struct svc_sock *bc_sock;
3075         struct rpc_xprt *ret;
3076
3077         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3078                         xprt_tcp_slot_table_entries);
3079         if (IS_ERR(xprt))
3080                 return xprt;
3081         transport = container_of(xprt, struct sock_xprt, xprt);
3082
3083         xprt->prot = IPPROTO_TCP;
3084         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3085         xprt->timeout = &xs_tcp_default_timeout;
3086
3087         /* backchannel */
3088         xprt_set_bound(xprt);
3089         xprt->bind_timeout = 0;
3090         xprt->reestablish_timeout = 0;
3091         xprt->idle_timeout = 0;
3092
3093         xprt->ops = &bc_tcp_ops;
3094
3095         switch (addr->sa_family) {
3096         case AF_INET:
3097                 xs_format_peer_addresses(xprt, "tcp",
3098                                          RPCBIND_NETID_TCP);
3099                 break;
3100         case AF_INET6:
3101                 xs_format_peer_addresses(xprt, "tcp",
3102                                    RPCBIND_NETID_TCP6);
3103                 break;
3104         default:
3105                 ret = ERR_PTR(-EAFNOSUPPORT);
3106                 goto out_err;
3107         }
3108
3109         dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3110                         xprt->address_strings[RPC_DISPLAY_ADDR],
3111                         xprt->address_strings[RPC_DISPLAY_PORT],
3112                         xprt->address_strings[RPC_DISPLAY_PROTO]);
3113
3114         /*
3115          * Once we've associated a backchannel xprt with a connection,
3116          * we want to keep it around as long as the connection lasts,
3117          * in case we need to start using it for a backchannel again;
3118          * this reference won't be dropped until bc_xprt is destroyed.
3119          */
3120         xprt_get(xprt);
3121         args->bc_xprt->xpt_bc_xprt = xprt;
3122         xprt->bc_xprt = args->bc_xprt;
3123         bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3124         transport->sock = bc_sock->sk_sock;
3125         transport->inet = bc_sock->sk_sk;
3126
3127         /*
3128          * Since we don't want connections for the backchannel, we set
3129          * the xprt status to connected
3130          */
3131         xprt_set_connected(xprt);
3132
3133         if (try_module_get(THIS_MODULE))
3134                 return xprt;
3135
3136         args->bc_xprt->xpt_bc_xprt = NULL;
3137         args->bc_xprt->xpt_bc_xps = NULL;
3138         xprt_put(xprt);
3139         ret = ERR_PTR(-EINVAL);
3140 out_err:
3141         xs_xprt_free(xprt);
3142         return ret;
3143 }
3144
3145 static struct xprt_class        xs_local_transport = {
3146         .list           = LIST_HEAD_INIT(xs_local_transport.list),
3147         .name           = "named UNIX socket",
3148         .owner          = THIS_MODULE,
3149         .ident          = XPRT_TRANSPORT_LOCAL,
3150         .setup          = xs_setup_local,
3151 };
3152
3153 static struct xprt_class        xs_udp_transport = {
3154         .list           = LIST_HEAD_INIT(xs_udp_transport.list),
3155         .name           = "udp",
3156         .owner          = THIS_MODULE,
3157         .ident          = XPRT_TRANSPORT_UDP,
3158         .setup          = xs_setup_udp,
3159 };
3160
3161 static struct xprt_class        xs_tcp_transport = {
3162         .list           = LIST_HEAD_INIT(xs_tcp_transport.list),
3163         .name           = "tcp",
3164         .owner          = THIS_MODULE,
3165         .ident          = XPRT_TRANSPORT_TCP,
3166         .setup          = xs_setup_tcp,
3167 };
3168
3169 static struct xprt_class        xs_bc_tcp_transport = {
3170         .list           = LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3171         .name           = "tcp NFSv4.1 backchannel",
3172         .owner          = THIS_MODULE,
3173         .ident          = XPRT_TRANSPORT_BC_TCP,
3174         .setup          = xs_setup_bc_tcp,
3175 };
3176
3177 /**
3178  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3179  *
3180  */
3181 int init_socket_xprt(void)
3182 {
3183         if (!sunrpc_table_header)
3184                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
3185
3186         xprt_register_transport(&xs_local_transport);
3187         xprt_register_transport(&xs_udp_transport);
3188         xprt_register_transport(&xs_tcp_transport);
3189         xprt_register_transport(&xs_bc_tcp_transport);
3190
3191         return 0;
3192 }
3193
3194 /**
3195  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3196  *
3197  */
3198 void cleanup_socket_xprt(void)
3199 {
3200         if (sunrpc_table_header) {
3201                 unregister_sysctl_table(sunrpc_table_header);
3202                 sunrpc_table_header = NULL;
3203         }
3204
3205         xprt_unregister_transport(&xs_local_transport);
3206         xprt_unregister_transport(&xs_udp_transport);
3207         xprt_unregister_transport(&xs_tcp_transport);
3208         xprt_unregister_transport(&xs_bc_tcp_transport);
3209 }
3210
3211 static int param_set_uint_minmax(const char *val,
3212                 const struct kernel_param *kp,
3213                 unsigned int min, unsigned int max)
3214 {
3215         unsigned int num;
3216         int ret;
3217
3218         if (!val)
3219                 return -EINVAL;
3220         ret = kstrtouint(val, 0, &num);
3221         if (ret)
3222                 return ret;
3223         if (num < min || num > max)
3224                 return -EINVAL;
3225         *((unsigned int *)kp->arg) = num;
3226         return 0;
3227 }
3228
3229 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3230 {
3231         return param_set_uint_minmax(val, kp,
3232                         RPC_MIN_RESVPORT,
3233                         RPC_MAX_RESVPORT);
3234 }
3235
3236 static const struct kernel_param_ops param_ops_portnr = {
3237         .set = param_set_portnr,
3238         .get = param_get_uint,
3239 };
3240
3241 #define param_check_portnr(name, p) \
3242         __param_check(name, p, unsigned int);
3243
3244 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3245 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3246
3247 static int param_set_slot_table_size(const char *val,
3248                                      const struct kernel_param *kp)
3249 {
3250         return param_set_uint_minmax(val, kp,
3251                         RPC_MIN_SLOT_TABLE,
3252                         RPC_MAX_SLOT_TABLE);
3253 }
3254
3255 static const struct kernel_param_ops param_ops_slot_table_size = {
3256         .set = param_set_slot_table_size,
3257         .get = param_get_uint,
3258 };
3259
3260 #define param_check_slot_table_size(name, p) \
3261         __param_check(name, p, unsigned int);
3262
3263 static int param_set_max_slot_table_size(const char *val,
3264                                      const struct kernel_param *kp)
3265 {
3266         return param_set_uint_minmax(val, kp,
3267                         RPC_MIN_SLOT_TABLE,
3268                         RPC_MAX_SLOT_TABLE_LIMIT);
3269 }
3270
3271 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3272         .set = param_set_max_slot_table_size,
3273         .get = param_get_uint,
3274 };
3275
3276 #define param_check_max_slot_table_size(name, p) \
3277         __param_check(name, p, unsigned int);
3278
3279 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3280                    slot_table_size, 0644);
3281 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3282                    max_slot_table_size, 0644);
3283 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3284                    slot_table_size, 0644);