net/smc/af_smc.c

   1 /*
   2  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
   3  *
   4  *  AF_SMC protocol family socket handler keeping the AF_INET sock address type
   5  *  applies to SOCK_STREAM sockets only
   6  *  offers an alternative communication option for TCP-protocol sockets
   7  *  applicable with RoCE-cards only
   8  *
   9  *  Initial restrictions:
  10  *    - support for alternate links postponed
  11  *
  12  *  Copyright IBM Corp. 2016, 2018
  13  *
  14  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
  15  *              based on prototype from Frank Blaschka
  16  */
  17
  18 #define KMSG_COMPONENT "smc"
  19 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  20
  21 #include <linux/module.h>
  22 #include <linux/socket.h>
  23 #include <linux/workqueue.h>
  24 #include <linux/in.h>
  25 #include <linux/sched/signal.h>
  26
  27 #include <net/sock.h>
  28 #include <net/tcp.h>
  29 #include <net/smc.h>
  30 #include <asm/ioctls.h>
  31
  32 #include "smc.h"
  33 #include "smc_clc.h"
  34 #include "smc_llc.h"
  35 #include "smc_cdc.h"
  36 #include "smc_core.h"
  37 #include "smc_ib.h"
  38 #include "smc_pnet.h"
  39 #include "smc_tx.h"
  40 #include "smc_rx.h"
  41 #include "smc_close.h"
  42
  43 static DEFINE_MUTEX(smc_create_lgr_pending);    /* serialize link group
  44                                                  * creation
  45                                                  */
  46
  47 static void smc_tcp_listen_work(struct work_struct *);
  48
  49 static void smc_set_keepalive(struct sock *sk, int val)
  50 {
  51         struct smc_sock *smc = smc_sk(sk);
  52
  53         smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
  54 }
  55
  56 static struct smc_hashinfo smc_v4_hashinfo = {
  57         .lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
  58 };
  59
  60 static struct smc_hashinfo smc_v6_hashinfo = {
  61         .lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
  62 };
  63
  64 int smc_hash_sk(struct sock *sk)
  65 {
  66         struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
  67         struct hlist_head *head;
  68
  69         head = &h->ht;
  70
  71         write_lock_bh(&h->lock);
  72         sk_add_node(sk, head);
  73         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
  74         write_unlock_bh(&h->lock);
  75
  76         return 0;
  77 }
  78 EXPORT_SYMBOL_GPL(smc_hash_sk);
  79
  80 void smc_unhash_sk(struct sock *sk)
  81 {
  82         struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
  83
  84         write_lock_bh(&h->lock);
  85         if (sk_del_node_init(sk))
  86                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
  87         write_unlock_bh(&h->lock);
  88 }
  89 EXPORT_SYMBOL_GPL(smc_unhash_sk);
  90
  91 struct proto smc_proto = {
  92         .name           = "SMC",
  93         .owner          = THIS_MODULE,
  94         .keepalive      = smc_set_keepalive,
  95         .hash           = smc_hash_sk,
  96         .unhash         = smc_unhash_sk,
  97         .obj_size       = sizeof(struct smc_sock),
  98         .h.smc_hash     = &smc_v4_hashinfo,
  99         .slab_flags     = SLAB_TYPESAFE_BY_RCU,
 100 };
 101 EXPORT_SYMBOL_GPL(smc_proto);
 102
 103 struct proto smc_proto6 = {
 104         .name           = "SMC6",
 105         .owner          = THIS_MODULE,
 106         .keepalive      = smc_set_keepalive,
 107         .hash           = smc_hash_sk,
 108         .unhash         = smc_unhash_sk,
 109         .obj_size       = sizeof(struct smc_sock),
 110         .h.smc_hash     = &smc_v6_hashinfo,
 111         .slab_flags     = SLAB_TYPESAFE_BY_RCU,
 112 };
 113 EXPORT_SYMBOL_GPL(smc_proto6);
 114
 115 static int smc_release(struct socket *sock)
 116 {
 117         struct sock *sk = sock->sk;
 118         struct smc_sock *smc;
 119         int rc = 0;
 120
 121         if (!sk)
 122                 goto out;
 123
 124         smc = smc_sk(sk);
 125         if (sk->sk_state == SMC_LISTEN)
 126                 /* smc_close_non_accepted() is called and acquires
 127                  * sock lock for child sockets again
 128                  */
 129                 lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 130         else
 131                 lock_sock(sk);
 132
 133         if (!smc->use_fallback) {
 134                 rc = smc_close_active(smc);
 135                 sock_set_flag(sk, SOCK_DEAD);
 136                 sk->sk_shutdown |= SHUTDOWN_MASK;
 137         }
 138         if (smc->clcsock) {
 139                 sock_release(smc->clcsock);
 140                 smc->clcsock = NULL;
 141         }
 142         if (smc->use_fallback) {
 143                 sock_put(sk); /* passive closing */
 144                 sk->sk_state = SMC_CLOSED;
 145                 sk->sk_state_change(sk);
 146         }
 147
 148         /* detach socket */
 149         sock_orphan(sk);
 150         sock->sk = NULL;
 151         if (!smc->use_fallback && sk->sk_state == SMC_CLOSED)
 152                 smc_conn_free(&smc->conn);
 153         release_sock(sk);
 154
 155         sk->sk_prot->unhash(sk);
 156         sock_put(sk); /* final sock_put */
 157 out:
 158         return rc;
 159 }
 160
 161 static void smc_destruct(struct sock *sk)
 162 {
 163         if (sk->sk_state != SMC_CLOSED)
 164                 return;
 165         if (!sock_flag(sk, SOCK_DEAD))
 166                 return;
 167
 168         sk_refcnt_debug_dec(sk);
 169 }
 170
 171 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
 172                                    int protocol)
 173 {
 174         struct smc_sock *smc;
 175         struct proto *prot;
 176         struct sock *sk;
 177
 178         prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
 179         sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
 180         if (!sk)
 181                 return NULL;
 182
 183         sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
 184         sk->sk_state = SMC_INIT;
 185         sk->sk_destruct = smc_destruct;
 186         sk->sk_protocol = protocol;
 187         smc = smc_sk(sk);
 188         INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
 189         INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
 190         INIT_LIST_HEAD(&smc->accept_q);
 191         spin_lock_init(&smc->accept_q_lock);
 192         spin_lock_init(&smc->conn.send_lock);
 193         sk->sk_prot->hash(sk);
 194         sk_refcnt_debug_inc(sk);
 195
 196         return sk;
 197 }
 198
 199 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
 200                     int addr_len)
 201 {
 202         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
 203         struct sock *sk = sock->sk;
 204         struct smc_sock *smc;
 205         int rc;
 206
 207         smc = smc_sk(sk);
 208
 209         /* replicate tests from inet_bind(), to be safe wrt. future changes */
 210         rc = -EINVAL;
 211         if (addr_len < sizeof(struct sockaddr_in))
 212                 goto out;
 213
 214         rc = -EAFNOSUPPORT;
 215         if (addr->sin_family != AF_INET &&
 216             addr->sin_family != AF_INET6 &&
 217             addr->sin_family != AF_UNSPEC)
 218                 goto out;
 219         /* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
 220         if (addr->sin_family == AF_UNSPEC &&
 221             addr->sin_addr.s_addr != htonl(INADDR_ANY))
 222                 goto out;
 223
 224         lock_sock(sk);
 225
 226         /* Check if socket is already active */
 227         rc = -EINVAL;
 228         if (sk->sk_state != SMC_INIT)
 229                 goto out_rel;
 230
 231         smc->clcsock->sk->sk_reuse = sk->sk_reuse;
 232         rc = kernel_bind(smc->clcsock, uaddr, addr_len);
 233
 234 out_rel:
 235         release_sock(sk);
 236 out:
 237         return rc;
 238 }
 239
 240 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
 241                                    unsigned long mask)
 242 {
 243         /* options we don't get control via setsockopt for */
 244         nsk->sk_type = osk->sk_type;
 245         nsk->sk_sndbuf = osk->sk_sndbuf;
 246         nsk->sk_rcvbuf = osk->sk_rcvbuf;
 247         nsk->sk_sndtimeo = osk->sk_sndtimeo;
 248         nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
 249         nsk->sk_mark = osk->sk_mark;
 250         nsk->sk_priority = osk->sk_priority;
 251         nsk->sk_rcvlowat = osk->sk_rcvlowat;
 252         nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
 253         nsk->sk_err = osk->sk_err;
 254
 255         nsk->sk_flags &= ~mask;
 256         nsk->sk_flags |= osk->sk_flags & mask;
 257 }
 258
 259 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
 260                              (1UL << SOCK_KEEPOPEN) | \
 261                              (1UL << SOCK_LINGER) | \
 262                              (1UL << SOCK_BROADCAST) | \
 263                              (1UL << SOCK_TIMESTAMP) | \
 264                              (1UL << SOCK_DBG) | \
 265                              (1UL << SOCK_RCVTSTAMP) | \
 266                              (1UL << SOCK_RCVTSTAMPNS) | \
 267                              (1UL << SOCK_LOCALROUTE) | \
 268                              (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
 269                              (1UL << SOCK_RXQ_OVFL) | \
 270                              (1UL << SOCK_WIFI_STATUS) | \
 271                              (1UL << SOCK_NOFCS) | \
 272                              (1UL << SOCK_FILTER_LOCKED))
 273 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
 274  * clc socket (since smc is not called for these options from net/core)
 275  */
 276 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
 277 {
 278         smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
 279 }
 280
 281 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
 282                              (1UL << SOCK_KEEPOPEN) | \
 283                              (1UL << SOCK_LINGER) | \
 284                              (1UL << SOCK_DBG))
 285 /* copy only settings and flags relevant for smc from clc to smc socket */
 286 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
 287 {
 288         smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
 289 }
 290
 291 /* register a new rmb, optionally send confirm_rkey msg to register with peer */
 292 static int smc_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc,
 293                        bool conf_rkey)
 294 {
 295         /* register memory region for new rmb */
 296         if (smc_wr_reg_send(link, rmb_desc->mr_rx[SMC_SINGLE_LINK])) {
 297                 rmb_desc->regerr = 1;
 298                 return -EFAULT;
 299         }
 300         if (!conf_rkey)
 301                 return 0;
 302         /* exchange confirm_rkey msg with peer */
 303         if (smc_llc_do_confirm_rkey(link, rmb_desc)) {
 304                 rmb_desc->regerr = 1;
 305                 return -EFAULT;
 306         }
 307         return 0;
 308 }
 309
 310 static int smc_clnt_conf_first_link(struct smc_sock *smc)
 311 {
 312         struct net *net = sock_net(smc->clcsock->sk);
 313         struct smc_link_group *lgr = smc->conn.lgr;
 314         struct smc_link *link;
 315         int rest;
 316         int rc;
 317
 318         link = &lgr->lnk[SMC_SINGLE_LINK];
 319         /* receive CONFIRM LINK request from server over RoCE fabric */
 320         rest = wait_for_completion_interruptible_timeout(
 321                 &link->llc_confirm,
 322                 SMC_LLC_WAIT_FIRST_TIME);
 323         if (rest <= 0) {
 324                 struct smc_clc_msg_decline dclc;
 325
 326                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
 327                                       SMC_CLC_DECLINE);
 328                 return rc;
 329         }
 330
 331         if (link->llc_confirm_rc)
 332                 return SMC_CLC_DECL_RMBE_EC;
 333
 334         rc = smc_ib_modify_qp_rts(link);
 335         if (rc)
 336                 return SMC_CLC_DECL_INTERR;
 337
 338         smc_wr_remember_qp_attr(link);
 339
 340         if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
 341                 return SMC_CLC_DECL_INTERR;
 342
 343         /* send CONFIRM LINK response over RoCE fabric */
 344         rc = smc_llc_send_confirm_link(link,
 345                                        link->smcibdev->mac[link->ibport - 1],
 346                                        &link->smcibdev->gid[link->ibport - 1],
 347                                        SMC_LLC_RESP);
 348         if (rc < 0)
 349                 return SMC_CLC_DECL_TCL;
 350
 351         /* receive ADD LINK request from server over RoCE fabric */
 352         rest = wait_for_completion_interruptible_timeout(&link->llc_add,
 353                                                          SMC_LLC_WAIT_TIME);
 354         if (rest <= 0) {
 355                 struct smc_clc_msg_decline dclc;
 356
 357                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
 358                                       SMC_CLC_DECLINE);
 359                 return rc;
 360         }
 361
 362         /* send add link reject message, only one link supported for now */
 363         rc = smc_llc_send_add_link(link,
 364                                    link->smcibdev->mac[link->ibport - 1],
 365                                    &link->smcibdev->gid[link->ibport - 1],
 366                                    SMC_LLC_RESP);
 367         if (rc < 0)
 368                 return SMC_CLC_DECL_TCL;
 369
 370         smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
 371
 372         return 0;
 373 }
 374
 375 static void smc_conn_save_peer_info(struct smc_sock *smc,
 376                                     struct smc_clc_msg_accept_confirm *clc)
 377 {
 378         int bufsize = smc_uncompress_bufsize(clc->rmbe_size);
 379
 380         smc->conn.peer_rmbe_idx = clc->rmbe_idx;
 381         smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
 382         smc->conn.peer_rmbe_size = bufsize;
 383         atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
 384         smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
 385 }
 386
 387 static void smc_link_save_peer_info(struct smc_link *link,
 388                                     struct smc_clc_msg_accept_confirm *clc)
 389 {
 390         link->peer_qpn = ntoh24(clc->qpn);
 391         memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
 392         memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
 393         link->peer_psn = ntoh24(clc->psn);
 394         link->peer_mtu = clc->qp_mtu;
 395 }
 396
 397 /* fall back during connect */
 398 static int smc_connect_fallback(struct smc_sock *smc)
 399 {
 400         smc->use_fallback = true;
 401         smc_copy_sock_settings_to_clc(smc);
 402         if (smc->sk.sk_state == SMC_INIT)
 403                 smc->sk.sk_state = SMC_ACTIVE;
 404         return 0;
 405 }
 406
 407 /* decline and fall back during connect */
 408 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code)
 409 {
 410         int rc;
 411
 412         if (reason_code < 0) /* error, fallback is not possible */
 413                 return reason_code;
 414         if (reason_code != SMC_CLC_DECL_REPLY) {
 415                 rc = smc_clc_send_decline(smc, reason_code);
 416                 if (rc < 0)
 417                         return rc;
 418         }
 419         return smc_connect_fallback(smc);
 420 }
 421
 422 /* abort connecting */
 423 static int smc_connect_abort(struct smc_sock *smc, int reason_code,
 424                              int local_contact)
 425 {
 426         if (local_contact == SMC_FIRST_CONTACT)
 427                 smc_lgr_forget(smc->conn.lgr);
 428         mutex_unlock(&smc_create_lgr_pending);
 429         smc_conn_free(&smc->conn);
 430         if (reason_code < 0 && smc->sk.sk_state == SMC_INIT)
 431                 sock_put(&smc->sk); /* passive closing */
 432         return reason_code;
 433 }
 434
 435 /* check if there is a rdma device available for this connection. */
 436 /* called for connect and listen */
 437 static int smc_check_rdma(struct smc_sock *smc, struct smc_ib_device **ibdev,
 438                           u8 *ibport)
 439 {
 440         int reason_code = 0;
 441
 442         /* PNET table look up: search active ib_device and port
 443          * within same PNETID that also contains the ethernet device
 444          * used for the internal TCP socket
 445          */
 446         smc_pnet_find_roce_resource(smc->clcsock->sk, ibdev, ibport);
 447         if (!(*ibdev))
 448                 reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
 449
 450         return reason_code;
 451 }
 452
 453 /* CLC handshake during connect */
 454 static int smc_connect_clc(struct smc_sock *smc,
 455                            struct smc_clc_msg_accept_confirm *aclc,
 456                            struct smc_ib_device *ibdev, u8 ibport)
 457 {
 458         int rc = 0;
 459
 460         /* do inband token exchange */
 461         rc = smc_clc_send_proposal(smc, ibdev, ibport);
 462         if (rc)
 463                 return rc;
 464         /* receive SMC Accept CLC message */
 465         return smc_clc_wait_msg(smc, aclc, sizeof(*aclc), SMC_CLC_ACCEPT);
 466 }
 467
 468 /* setup for RDMA connection of client */
 469 static int smc_connect_rdma(struct smc_sock *smc,
 470                             struct smc_clc_msg_accept_confirm *aclc,
 471                             struct smc_ib_device *ibdev, u8 ibport)
 472 {
 473         int local_contact = SMC_FIRST_CONTACT;
 474         struct smc_link *link;
 475         int reason_code = 0;
 476
 477         mutex_lock(&smc_create_lgr_pending);
 478         local_contact = smc_conn_create(smc, ibdev, ibport, &aclc->lcl,
 479                                         aclc->hdr.flag);
 480         if (local_contact < 0) {
 481                 if (local_contact == -ENOMEM)
 482                         reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
 483                 else if (local_contact == -ENOLINK)
 484                         reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
 485                 else
 486                         reason_code = SMC_CLC_DECL_INTERR; /* other error */
 487                 return smc_connect_abort(smc, reason_code, 0);
 488         }
 489         link = &smc->conn.lgr->lnk[SMC_SINGLE_LINK];
 490
 491         smc_conn_save_peer_info(smc, aclc);
 492
 493         /* create send buffer and rmb */
 494         if (smc_buf_create(smc))
 495                 return smc_connect_abort(smc, SMC_CLC_DECL_MEM, local_contact);
 496
 497         if (local_contact == SMC_FIRST_CONTACT)
 498                 smc_link_save_peer_info(link, aclc);
 499
 500         if (smc_rmb_rtoken_handling(&smc->conn, aclc))
 501                 return smc_connect_abort(smc, SMC_CLC_DECL_INTERR,
 502                                          local_contact);
 503
 504         smc_close_init(smc);
 505         smc_rx_init(smc);
 506
 507         if (local_contact == SMC_FIRST_CONTACT) {
 508                 if (smc_ib_ready_link(link))
 509                         return smc_connect_abort(smc, SMC_CLC_DECL_INTERR,
 510                                                  local_contact);
 511         } else {
 512                 if (!smc->conn.rmb_desc->reused &&
 513                     smc_reg_rmb(link, smc->conn.rmb_desc, true))
 514                         return smc_connect_abort(smc, SMC_CLC_DECL_INTERR,
 515                                                  local_contact);
 516         }
 517         smc_rmb_sync_sg_for_device(&smc->conn);
 518
 519         reason_code = smc_clc_send_confirm(smc);
 520         if (reason_code)
 521                 return smc_connect_abort(smc, reason_code, local_contact);
 522
 523         smc_tx_init(smc);
 524
 525         if (local_contact == SMC_FIRST_CONTACT) {
 526                 /* QP confirmation over RoCE fabric */
 527                 reason_code = smc_clnt_conf_first_link(smc);
 528                 if (reason_code)
 529                         return smc_connect_abort(smc, reason_code,
 530                                                  local_contact);
 531         }
 532         mutex_unlock(&smc_create_lgr_pending);
 533
 534         smc_copy_sock_settings_to_clc(smc);
 535         if (smc->sk.sk_state == SMC_INIT)
 536                 smc->sk.sk_state = SMC_ACTIVE;
 537
 538         return 0;
 539 }
 540
 541 /* perform steps before actually connecting */
 542 static int __smc_connect(struct smc_sock *smc)
 543 {
 544         struct smc_clc_msg_accept_confirm aclc;
 545         struct smc_ib_device *ibdev;
 546         int rc = 0;
 547         u8 ibport;
 548
 549         sock_hold(&smc->sk); /* sock put in passive closing */
 550
 551         if (smc->use_fallback)
 552                 return smc_connect_fallback(smc);
 553
 554         /* if peer has not signalled SMC-capability, fall back */
 555         if (!tcp_sk(smc->clcsock->sk)->syn_smc)
 556                 return smc_connect_fallback(smc);
 557
 558         /* IPSec connections opt out of SMC-R optimizations */
 559         if (using_ipsec(smc))
 560                 return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC);
 561
 562         /* check if a RDMA device is available; if not, fall back */
 563         if (smc_check_rdma(smc, &ibdev, &ibport))
 564                 return smc_connect_decline_fallback(smc, SMC_CLC_DECL_CNFERR);
 565
 566         /* perform CLC handshake */
 567         rc = smc_connect_clc(smc, &aclc, ibdev, ibport);
 568         if (rc)
 569                 return smc_connect_decline_fallback(smc, rc);
 570
 571         /* connect using rdma */
 572         rc = smc_connect_rdma(smc, &aclc, ibdev, ibport);
 573         if (rc)
 574                 return smc_connect_decline_fallback(smc, rc);
 575
 576         return 0;
 577 }
 578
 579 static int smc_connect(struct socket *sock, struct sockaddr *addr,
 580                        int alen, int flags)
 581 {
 582         struct sock *sk = sock->sk;
 583         struct smc_sock *smc;
 584         int rc = -EINVAL;
 585
 586         smc = smc_sk(sk);
 587
 588         /* separate smc parameter checking to be safe */
 589         if (alen < sizeof(addr->sa_family))
 590                 goto out_err;
 591         if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
 592                 goto out_err;
 593
 594         lock_sock(sk);
 595         switch (sk->sk_state) {
 596         default:
 597                 goto out;
 598         case SMC_ACTIVE:
 599                 rc = -EISCONN;
 600                 goto out;
 601         case SMC_INIT:
 602                 rc = 0;
 603                 break;
 604         }
 605
 606         smc_copy_sock_settings_to_clc(smc);
 607         tcp_sk(smc->clcsock->sk)->syn_smc = 1;
 608         rc = kernel_connect(smc->clcsock, addr, alen, flags);
 609         if (rc)
 610                 goto out;
 611
 612         rc = __smc_connect(smc);
 613         if (rc < 0)
 614                 goto out;
 615         else
 616                 rc = 0; /* success cases including fallback */
 617
 618 out:
 619         release_sock(sk);
 620 out_err:
 621         return rc;
 622 }
 623
 624 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
 625 {
 626         struct socket *new_clcsock = NULL;
 627         struct sock *lsk = &lsmc->sk;
 628         struct sock *new_sk;
 629         int rc;
 630
 631         release_sock(lsk);
 632         new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
 633         if (!new_sk) {
 634                 rc = -ENOMEM;
 635                 lsk->sk_err = ENOMEM;
 636                 *new_smc = NULL;
 637                 lock_sock(lsk);
 638                 goto out;
 639         }
 640         *new_smc = smc_sk(new_sk);
 641
 642         rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
 643         lock_sock(lsk);
 644         if  (rc < 0)
 645                 lsk->sk_err = -rc;
 646         if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
 647                 if (new_clcsock)
 648                         sock_release(new_clcsock);
 649                 new_sk->sk_state = SMC_CLOSED;
 650                 sock_set_flag(new_sk, SOCK_DEAD);
 651                 new_sk->sk_prot->unhash(new_sk);
 652                 sock_put(new_sk); /* final */
 653                 *new_smc = NULL;
 654                 goto out;
 655         }
 656
 657         (*new_smc)->clcsock = new_clcsock;
 658 out:
 659         return rc;
 660 }
 661
 662 /* add a just created sock to the accept queue of the listen sock as
 663  * candidate for a following socket accept call from user space
 664  */
 665 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
 666 {
 667         struct smc_sock *par = smc_sk(parent);
 668
 669         sock_hold(sk); /* sock_put in smc_accept_unlink () */
 670         spin_lock(&par->accept_q_lock);
 671         list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
 672         spin_unlock(&par->accept_q_lock);
 673         sk_acceptq_added(parent);
 674 }
 675
 676 /* remove a socket from the accept queue of its parental listening socket */
 677 static void smc_accept_unlink(struct sock *sk)
 678 {
 679         struct smc_sock *par = smc_sk(sk)->listen_smc;
 680
 681         spin_lock(&par->accept_q_lock);
 682         list_del_init(&smc_sk(sk)->accept_q);
 683         spin_unlock(&par->accept_q_lock);
 684         sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
 685         sock_put(sk); /* sock_hold in smc_accept_enqueue */
 686 }
 687
 688 /* remove a sock from the accept queue to bind it to a new socket created
 689  * for a socket accept call from user space
 690  */
 691 struct sock *smc_accept_dequeue(struct sock *parent,
 692                                 struct socket *new_sock)
 693 {
 694         struct smc_sock *isk, *n;
 695         struct sock *new_sk;
 696
 697         list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
 698                 new_sk = (struct sock *)isk;
 699
 700                 smc_accept_unlink(new_sk);
 701                 if (new_sk->sk_state == SMC_CLOSED) {
 702                         if (isk->clcsock) {
 703                                 sock_release(isk->clcsock);
 704                                 isk->clcsock = NULL;
 705                         }
 706                         new_sk->sk_prot->unhash(new_sk);
 707                         sock_put(new_sk); /* final */
 708                         continue;
 709                 }
 710                 if (new_sock)
 711                         sock_graft(new_sk, new_sock);
 712                 return new_sk;
 713         }
 714         return NULL;
 715 }
 716
 717 /* clean up for a created but never accepted sock */
 718 void smc_close_non_accepted(struct sock *sk)
 719 {
 720         struct smc_sock *smc = smc_sk(sk);
 721
 722         lock_sock(sk);
 723         if (!sk->sk_lingertime)
 724                 /* wait for peer closing */
 725                 sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
 726         if (!smc->use_fallback) {
 727                 smc_close_active(smc);
 728                 sock_set_flag(sk, SOCK_DEAD);
 729                 sk->sk_shutdown |= SHUTDOWN_MASK;
 730         }
 731         if (smc->clcsock) {
 732                 struct socket *tcp;
 733
 734                 tcp = smc->clcsock;
 735                 smc->clcsock = NULL;
 736                 sock_release(tcp);
 737         }
 738         if (smc->use_fallback) {
 739                 sock_put(sk); /* passive closing */
 740                 sk->sk_state = SMC_CLOSED;
 741         } else {
 742                 if (sk->sk_state == SMC_CLOSED)
 743                         smc_conn_free(&smc->conn);
 744         }
 745         release_sock(sk);
 746         sk->sk_prot->unhash(sk);
 747         sock_put(sk); /* final sock_put */
 748 }
 749
 750 static int smc_serv_conf_first_link(struct smc_sock *smc)
 751 {
 752         struct net *net = sock_net(smc->clcsock->sk);
 753         struct smc_link_group *lgr = smc->conn.lgr;
 754         struct smc_link *link;
 755         int rest;
 756         int rc;
 757
 758         link = &lgr->lnk[SMC_SINGLE_LINK];
 759
 760         if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
 761                 return SMC_CLC_DECL_INTERR;
 762
 763         /* send CONFIRM LINK request to client over the RoCE fabric */
 764         rc = smc_llc_send_confirm_link(link,
 765                                        link->smcibdev->mac[link->ibport - 1],
 766                                        &link->smcibdev->gid[link->ibport - 1],
 767                                        SMC_LLC_REQ);
 768         if (rc < 0)
 769                 return SMC_CLC_DECL_TCL;
 770
 771         /* receive CONFIRM LINK response from client over the RoCE fabric */
 772         rest = wait_for_completion_interruptible_timeout(
 773                 &link->llc_confirm_resp,
 774                 SMC_LLC_WAIT_FIRST_TIME);
 775         if (rest <= 0) {
 776                 struct smc_clc_msg_decline dclc;
 777
 778                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
 779                                       SMC_CLC_DECLINE);
 780                 return rc;
 781         }
 782
 783         if (link->llc_confirm_resp_rc)
 784                 return SMC_CLC_DECL_RMBE_EC;
 785
 786         /* send ADD LINK request to client over the RoCE fabric */
 787         rc = smc_llc_send_add_link(link,
 788                                    link->smcibdev->mac[link->ibport - 1],
 789                                    &link->smcibdev->gid[link->ibport - 1],
 790                                    SMC_LLC_REQ);
 791         if (rc < 0)
 792                 return SMC_CLC_DECL_TCL;
 793
 794         /* receive ADD LINK response from client over the RoCE fabric */
 795         rest = wait_for_completion_interruptible_timeout(&link->llc_add_resp,
 796                                                          SMC_LLC_WAIT_TIME);
 797         if (rest <= 0) {
 798                 struct smc_clc_msg_decline dclc;
 799
 800                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
 801                                       SMC_CLC_DECLINE);
 802                 return rc;
 803         }
 804
 805         smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
 806
 807         return 0;
 808 }
 809
 810 /* listen worker: finish */
 811 static void smc_listen_out(struct smc_sock *new_smc)
 812 {
 813         struct smc_sock *lsmc = new_smc->listen_smc;
 814         struct sock *newsmcsk = &new_smc->sk;
 815
 816         lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
 817         if (lsmc->sk.sk_state == SMC_LISTEN) {
 818                 smc_accept_enqueue(&lsmc->sk, newsmcsk);
 819         } else { /* no longer listening */
 820                 smc_close_non_accepted(newsmcsk);
 821         }
 822         release_sock(&lsmc->sk);
 823
 824         /* Wake up accept */
 825         lsmc->sk.sk_data_ready(&lsmc->sk);
 826         sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
 827 }
 828
 829 /* listen worker: finish in state connected */
 830 static void smc_listen_out_connected(struct smc_sock *new_smc)
 831 {
 832         struct sock *newsmcsk = &new_smc->sk;
 833
 834         sk_refcnt_debug_inc(newsmcsk);
 835         if (newsmcsk->sk_state == SMC_INIT)
 836                 newsmcsk->sk_state = SMC_ACTIVE;
 837
 838         smc_listen_out(new_smc);
 839 }
 840
 841 /* listen worker: finish in error state */
 842 static void smc_listen_out_err(struct smc_sock *new_smc)
 843 {
 844         struct sock *newsmcsk = &new_smc->sk;
 845
 846         if (newsmcsk->sk_state == SMC_INIT)
 847                 sock_put(&new_smc->sk); /* passive closing */
 848         newsmcsk->sk_state = SMC_CLOSED;
 849         smc_conn_free(&new_smc->conn);
 850
 851         smc_listen_out(new_smc);
 852 }
 853
 854 /* listen worker: decline and fall back if possible */
 855 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
 856                                int local_contact)
 857 {
 858         /* RDMA setup failed, switch back to TCP */
 859         if (local_contact == SMC_FIRST_CONTACT)
 860                 smc_lgr_forget(new_smc->conn.lgr);
 861         if (reason_code < 0) { /* error, no fallback possible */
 862                 smc_listen_out_err(new_smc);
 863                 return;
 864         }
 865         smc_conn_free(&new_smc->conn);
 866         new_smc->use_fallback = true;
 867         if (reason_code && reason_code != SMC_CLC_DECL_REPLY) {
 868                 if (smc_clc_send_decline(new_smc, reason_code) < 0) {
 869                         smc_listen_out_err(new_smc);
 870                         return;
 871                 }
 872         }
 873         smc_listen_out_connected(new_smc);
 874 }
 875
 876 /* listen worker: check prefixes */
 877 static int smc_listen_rdma_check(struct smc_sock *new_smc,
 878                                  struct smc_clc_msg_proposal *pclc)
 879 {
 880         struct smc_clc_msg_proposal_prefix *pclc_prfx;
 881         struct socket *newclcsock = new_smc->clcsock;
 882
 883         pclc_prfx = smc_clc_proposal_get_prefix(pclc);
 884         if (smc_clc_prfx_match(newclcsock, pclc_prfx))
 885                 return SMC_CLC_DECL_CNFERR;
 886
 887         return 0;
 888 }
 889
 890 /* listen worker: initialize connection and buffers */
 891 static int smc_listen_rdma_init(struct smc_sock *new_smc,
 892                                 struct smc_clc_msg_proposal *pclc,
 893                                 struct smc_ib_device *ibdev, u8 ibport,
 894                                 int *local_contact)
 895 {
 896         /* allocate connection / link group */
 897         *local_contact = smc_conn_create(new_smc, ibdev, ibport, &pclc->lcl, 0);
 898         if (*local_contact < 0) {
 899                 if (*local_contact == -ENOMEM)
 900                         return SMC_CLC_DECL_MEM;/* insufficient memory*/
 901                 return SMC_CLC_DECL_INTERR; /* other error */
 902         }
 903
 904         /* create send buffer and rmb */
 905         if (smc_buf_create(new_smc))
 906                 return SMC_CLC_DECL_MEM;
 907
 908         return 0;
 909 }
 910
 911 /* listen worker: register buffers */
 912 static int smc_listen_rdma_reg(struct smc_sock *new_smc, int local_contact)
 913 {
 914         struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
 915
 916         if (local_contact != SMC_FIRST_CONTACT) {
 917                 if (!new_smc->conn.rmb_desc->reused) {
 918                         if (smc_reg_rmb(link, new_smc->conn.rmb_desc, true))
 919                                 return SMC_CLC_DECL_INTERR;
 920                 }
 921         }
 922         smc_rmb_sync_sg_for_device(&new_smc->conn);
 923
 924         return 0;
 925 }
 926
 927 /* listen worker: finish RDMA setup */
 928 static void smc_listen_rdma_finish(struct smc_sock *new_smc,
 929                                    struct smc_clc_msg_accept_confirm *cclc,
 930                                    int local_contact)
 931 {
 932         struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
 933         int reason_code = 0;
 934
 935         if (local_contact == SMC_FIRST_CONTACT)
 936                 smc_link_save_peer_info(link, cclc);
 937
 938         if (smc_rmb_rtoken_handling(&new_smc->conn, cclc)) {
 939                 reason_code = SMC_CLC_DECL_INTERR;
 940                 goto decline;
 941         }
 942
 943         if (local_contact == SMC_FIRST_CONTACT) {
 944                 if (smc_ib_ready_link(link)) {
 945                         reason_code = SMC_CLC_DECL_INTERR;
 946                         goto decline;
 947                 }
 948                 /* QP confirmation over RoCE fabric */
 949                 reason_code = smc_serv_conf_first_link(new_smc);
 950                 if (reason_code)
 951                         goto decline;
 952         }
 953         return;
 954
 955 decline:
 956         mutex_unlock(&smc_create_lgr_pending);
 957         smc_listen_decline(new_smc, reason_code, local_contact);
 958 }
 959
 960 /* setup for RDMA connection of server */
 961 static void smc_listen_work(struct work_struct *work)
 962 {
 963         struct smc_sock *new_smc = container_of(work, struct smc_sock,
 964                                                 smc_listen_work);
 965         struct socket *newclcsock = new_smc->clcsock;
 966         struct smc_clc_msg_accept_confirm cclc;
 967         struct smc_clc_msg_proposal *pclc;
 968         struct smc_ib_device *ibdev;
 969         u8 buf[SMC_CLC_MAX_LEN];
 970         int local_contact = 0;
 971         int reason_code = 0;
 972         int rc = 0;
 973         u8 ibport;
 974
 975         if (new_smc->use_fallback) {
 976                 smc_listen_out_connected(new_smc);
 977                 return;
 978         }
 979
 980         /* check if peer is smc capable */
 981         if (!tcp_sk(newclcsock->sk)->syn_smc) {
 982                 new_smc->use_fallback = true;
 983                 smc_listen_out_connected(new_smc);
 984                 return;
 985         }
 986
 987         /* do inband token exchange -
 988          * wait for and receive SMC Proposal CLC message
 989          */
 990         pclc = (struct smc_clc_msg_proposal *)&buf;
 991         reason_code = smc_clc_wait_msg(new_smc, pclc, SMC_CLC_MAX_LEN,
 992                                        SMC_CLC_PROPOSAL);
 993         if (reason_code) {
 994                 smc_listen_decline(new_smc, reason_code, 0);
 995                 return;
 996         }
 997
 998         /* IPSec connections opt out of SMC-R optimizations */
 999         if (using_ipsec(new_smc)) {
1000                 smc_listen_decline(new_smc, SMC_CLC_DECL_IPSEC, 0);
1001                 return;
1002         }
1003
1004         mutex_lock(&smc_create_lgr_pending);
1005         smc_close_init(new_smc);
1006         smc_rx_init(new_smc);
1007         smc_tx_init(new_smc);
1008
1009         /* check if RDMA is available */
1010         if (smc_check_rdma(new_smc, &ibdev, &ibport) ||
1011             smc_listen_rdma_check(new_smc, pclc) ||
1012             smc_listen_rdma_init(new_smc, pclc, ibdev, ibport,
1013                                  &local_contact) ||
1014             smc_listen_rdma_reg(new_smc, local_contact)) {
1015                 /* SMC not supported, decline */
1016                 mutex_unlock(&smc_create_lgr_pending);
1017                 smc_listen_decline(new_smc, SMC_CLC_DECL_CNFERR, local_contact);
1018                 return;
1019         }
1020
1021         /* send SMC Accept CLC message */
1022         rc = smc_clc_send_accept(new_smc, local_contact);
1023         if (rc) {
1024                 mutex_unlock(&smc_create_lgr_pending);
1025                 smc_listen_decline(new_smc, rc, local_contact);
1026                 return;
1027         }
1028
1029         /* receive SMC Confirm CLC message */
1030         reason_code = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
1031                                        SMC_CLC_CONFIRM);
1032         if (reason_code) {
1033                 mutex_unlock(&smc_create_lgr_pending);
1034                 smc_listen_decline(new_smc, reason_code, local_contact);
1035                 return;
1036         }
1037
1038         /* finish worker */
1039         smc_listen_rdma_finish(new_smc, &cclc, local_contact);
1040         smc_conn_save_peer_info(new_smc, &cclc);
1041         mutex_unlock(&smc_create_lgr_pending);
1042         smc_listen_out_connected(new_smc);
1043 }
1044
1045 static void smc_tcp_listen_work(struct work_struct *work)
1046 {
1047         struct smc_sock *lsmc = container_of(work, struct smc_sock,
1048                                              tcp_listen_work);
1049         struct sock *lsk = &lsmc->sk;
1050         struct smc_sock *new_smc;
1051         int rc = 0;
1052
1053         lock_sock(lsk);
1054         while (lsk->sk_state == SMC_LISTEN) {
1055                 rc = smc_clcsock_accept(lsmc, &new_smc);
1056                 if (rc)
1057                         goto out;
1058                 if (!new_smc)
1059                         continue;
1060
1061                 new_smc->listen_smc = lsmc;
1062                 new_smc->use_fallback = lsmc->use_fallback;
1063                 sock_hold(lsk); /* sock_put in smc_listen_work */
1064                 INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
1065                 smc_copy_sock_settings_to_smc(new_smc);
1066                 sock_hold(&new_smc->sk); /* sock_put in passive closing */
1067                 if (!schedule_work(&new_smc->smc_listen_work))
1068                         sock_put(&new_smc->sk);
1069         }
1070
1071 out:
1072         release_sock(lsk);
1073         sock_put(&lsmc->sk); /* sock_hold in smc_listen */
1074 }
1075
1076 static int smc_listen(struct socket *sock, int backlog)
1077 {
1078         struct sock *sk = sock->sk;
1079         struct smc_sock *smc;
1080         int rc;
1081
1082         smc = smc_sk(sk);
1083         lock_sock(sk);
1084
1085         rc = -EINVAL;
1086         if ((sk->sk_state != SMC_INIT) && (sk->sk_state != SMC_LISTEN))
1087                 goto out;
1088
1089         rc = 0;
1090         if (sk->sk_state == SMC_LISTEN) {
1091                 sk->sk_max_ack_backlog = backlog;
1092                 goto out;
1093         }
1094         /* some socket options are handled in core, so we could not apply
1095          * them to the clc socket -- copy smc socket options to clc socket
1096          */
1097         smc_copy_sock_settings_to_clc(smc);
1098         if (!smc->use_fallback)
1099                 tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1100
1101         rc = kernel_listen(smc->clcsock, backlog);
1102         if (rc)
1103                 goto out;
1104         sk->sk_max_ack_backlog = backlog;
1105         sk->sk_ack_backlog = 0;
1106         sk->sk_state = SMC_LISTEN;
1107         INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
1108         sock_hold(sk); /* sock_hold in tcp_listen_worker */
1109         if (!schedule_work(&smc->tcp_listen_work))
1110                 sock_put(sk);
1111
1112 out:
1113         release_sock(sk);
1114         return rc;
1115 }
1116
1117 static int smc_accept(struct socket *sock, struct socket *new_sock,
1118                       int flags, bool kern)
1119 {
1120         struct sock *sk = sock->sk, *nsk;
1121         DECLARE_WAITQUEUE(wait, current);
1122         struct smc_sock *lsmc;
1123         long timeo;
1124         int rc = 0;
1125
1126         lsmc = smc_sk(sk);
1127         sock_hold(sk); /* sock_put below */
1128         lock_sock(sk);
1129
1130         if (lsmc->sk.sk_state != SMC_LISTEN) {
1131                 rc = -EINVAL;
1132                 release_sock(sk);
1133                 goto out;
1134         }
1135
1136         /* Wait for an incoming connection */
1137         timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1138         add_wait_queue_exclusive(sk_sleep(sk), &wait);
1139         while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1140                 set_current_state(TASK_INTERRUPTIBLE);
1141                 if (!timeo) {
1142                         rc = -EAGAIN;
1143                         break;
1144                 }
1145                 release_sock(sk);
1146                 timeo = schedule_timeout(timeo);
1147                 /* wakeup by sk_data_ready in smc_listen_work() */
1148                 sched_annotate_sleep();
1149                 lock_sock(sk);
1150                 if (signal_pending(current)) {
1151                         rc = sock_intr_errno(timeo);
1152                         break;
1153                 }
1154         }
1155         set_current_state(TASK_RUNNING);
1156         remove_wait_queue(sk_sleep(sk), &wait);
1157
1158         if (!rc)
1159                 rc = sock_error(nsk);
1160         release_sock(sk);
1161         if (rc)
1162                 goto out;
1163
1164         if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
1165                 /* wait till data arrives on the socket */
1166                 timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
1167                                                                 MSEC_PER_SEC);
1168                 if (smc_sk(nsk)->use_fallback) {
1169                         struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
1170
1171                         lock_sock(clcsk);
1172                         if (skb_queue_empty(&clcsk->sk_receive_queue))
1173                                 sk_wait_data(clcsk, &timeo, NULL);
1174                         release_sock(clcsk);
1175                 } else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
1176                         lock_sock(nsk);
1177                         smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
1178                         release_sock(nsk);
1179                 }
1180         }
1181
1182 out:
1183         sock_put(sk); /* sock_hold above */
1184         return rc;
1185 }
1186
1187 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1188                        int peer)
1189 {
1190         struct smc_sock *smc;
1191
1192         if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
1193             (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
1194                 return -ENOTCONN;
1195
1196         smc = smc_sk(sock->sk);
1197
1198         return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
1199 }
1200
1201 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1202 {
1203         struct sock *sk = sock->sk;
1204         struct smc_sock *smc;
1205         int rc = -EPIPE;
1206
1207         smc = smc_sk(sk);
1208         lock_sock(sk);
1209         if ((sk->sk_state != SMC_ACTIVE) &&
1210             (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1211             (sk->sk_state != SMC_INIT))
1212                 goto out;
1213
1214         if (msg->msg_flags & MSG_FASTOPEN) {
1215                 if (sk->sk_state == SMC_INIT) {
1216                         smc->use_fallback = true;
1217                 } else {
1218                         rc = -EINVAL;
1219                         goto out;
1220                 }
1221         }
1222
1223         if (smc->use_fallback)
1224                 rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
1225         else
1226                 rc = smc_tx_sendmsg(smc, msg, len);
1227 out:
1228         release_sock(sk);
1229         return rc;
1230 }
1231
1232 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1233                        int flags)
1234 {
1235         struct sock *sk = sock->sk;
1236         struct smc_sock *smc;
1237         int rc = -ENOTCONN;
1238
1239         smc = smc_sk(sk);
1240         lock_sock(sk);
1241         if ((sk->sk_state == SMC_INIT) ||
1242             (sk->sk_state == SMC_LISTEN) ||
1243             (sk->sk_state == SMC_CLOSED))
1244                 goto out;
1245
1246         if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1247                 rc = 0;
1248                 goto out;
1249         }
1250
1251         if (smc->use_fallback) {
1252                 rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
1253         } else {
1254                 msg->msg_namelen = 0;
1255                 rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
1256         }
1257
1258 out:
1259         release_sock(sk);
1260         return rc;
1261 }
1262
1263 static __poll_t smc_accept_poll(struct sock *parent)
1264 {
1265         struct smc_sock *isk = smc_sk(parent);
1266         __poll_t mask = 0;
1267
1268         spin_lock(&isk->accept_q_lock);
1269         if (!list_empty(&isk->accept_q))
1270                 mask = EPOLLIN | EPOLLRDNORM;
1271         spin_unlock(&isk->accept_q_lock);
1272
1273         return mask;
1274 }
1275
1276 static __poll_t smc_poll(struct file *file, struct socket *sock,
1277                              poll_table *wait)
1278 {
1279         struct sock *sk = sock->sk;
1280         __poll_t mask = 0;
1281         struct smc_sock *smc;
1282         int rc;
1283
1284         if (!sk)
1285                 return EPOLLNVAL;
1286
1287         smc = smc_sk(sock->sk);
1288         sock_hold(sk);
1289         lock_sock(sk);
1290         if ((sk->sk_state == SMC_INIT) || smc->use_fallback) {
1291                 /* delegate to CLC child sock */
1292                 release_sock(sk);
1293                 mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
1294                 lock_sock(sk);
1295                 sk->sk_err = smc->clcsock->sk->sk_err;
1296                 if (sk->sk_err) {
1297                         mask |= EPOLLERR;
1298                 } else {
1299                         /* if non-blocking connect finished ... */
1300                         if (sk->sk_state == SMC_INIT &&
1301                             mask & EPOLLOUT &&
1302                             smc->clcsock->sk->sk_state != TCP_CLOSE) {
1303                                 rc = __smc_connect(smc);
1304                                 if (rc < 0)
1305                                         mask |= EPOLLERR;
1306                                 /* success cases including fallback */
1307                                 mask |= EPOLLOUT | EPOLLWRNORM;
1308                         }
1309                 }
1310         } else {
1311                 if (sk->sk_state != SMC_CLOSED) {
1312                         release_sock(sk);
1313                         sock_poll_wait(file, sk_sleep(sk), wait);
1314                         lock_sock(sk);
1315                 }
1316                 if (sk->sk_err)
1317                         mask |= EPOLLERR;
1318                 if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1319                     (sk->sk_state == SMC_CLOSED))
1320                         mask |= EPOLLHUP;
1321                 if (sk->sk_state == SMC_LISTEN) {
1322                         /* woken up by sk_data_ready in smc_listen_work() */
1323                         mask = smc_accept_poll(sk);
1324                 } else {
1325                         if (atomic_read(&smc->conn.sndbuf_space) ||
1326                             sk->sk_shutdown & SEND_SHUTDOWN) {
1327                                 mask |= EPOLLOUT | EPOLLWRNORM;
1328                         } else {
1329                                 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1330                                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1331                         }
1332                         if (atomic_read(&smc->conn.bytes_to_rcv))
1333                                 mask |= EPOLLIN | EPOLLRDNORM;
1334                         if (sk->sk_shutdown & RCV_SHUTDOWN)
1335                                 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
1336                         if (sk->sk_state == SMC_APPCLOSEWAIT1)
1337                                 mask |= EPOLLIN;
1338                 }
1339                 if (smc->conn.urg_state == SMC_URG_VALID)
1340                         mask |= EPOLLPRI;
1341
1342         }
1343         release_sock(sk);
1344         sock_put(sk);
1345
1346         return mask;
1347 }
1348
1349 static int smc_shutdown(struct socket *sock, int how)
1350 {
1351         struct sock *sk = sock->sk;
1352         struct smc_sock *smc;
1353         int rc = -EINVAL;
1354         int rc1 = 0;
1355
1356         smc = smc_sk(sk);
1357
1358         if ((how < SHUT_RD) || (how > SHUT_RDWR))
1359                 return rc;
1360
1361         lock_sock(sk);
1362
1363         rc = -ENOTCONN;
1364         if ((sk->sk_state != SMC_LISTEN) &&
1365             (sk->sk_state != SMC_ACTIVE) &&
1366             (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
1367             (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
1368             (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1369             (sk->sk_state != SMC_APPCLOSEWAIT2) &&
1370             (sk->sk_state != SMC_APPFINCLOSEWAIT))
1371                 goto out;
1372         if (smc->use_fallback) {
1373                 rc = kernel_sock_shutdown(smc->clcsock, how);
1374                 sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
1375                 if (sk->sk_shutdown == SHUTDOWN_MASK)
1376                         sk->sk_state = SMC_CLOSED;
1377                 goto out;
1378         }
1379         switch (how) {
1380         case SHUT_RDWR:         /* shutdown in both directions */
1381                 rc = smc_close_active(smc);
1382                 break;
1383         case SHUT_WR:
1384                 rc = smc_close_shutdown_write(smc);
1385                 break;
1386         case SHUT_RD:
1387                 rc = 0;
1388                 /* nothing more to do because peer is not involved */
1389                 break;
1390         }
1391         if (smc->clcsock)
1392                 rc1 = kernel_sock_shutdown(smc->clcsock, how);
1393         /* map sock_shutdown_cmd constants to sk_shutdown value range */
1394         sk->sk_shutdown |= how + 1;
1395
1396 out:
1397         release_sock(sk);
1398         return rc ? rc : rc1;
1399 }
1400
1401 static int smc_setsockopt(struct socket *sock, int level, int optname,
1402                           char __user *optval, unsigned int optlen)
1403 {
1404         struct sock *sk = sock->sk;
1405         struct smc_sock *smc;
1406         int val, rc;
1407
1408         smc = smc_sk(sk);
1409
1410         /* generic setsockopts reaching us here always apply to the
1411          * CLC socket
1412          */
1413         rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
1414                                            optval, optlen);
1415         if (smc->clcsock->sk->sk_err) {
1416                 sk->sk_err = smc->clcsock->sk->sk_err;
1417                 sk->sk_error_report(sk);
1418         }
1419         if (rc)
1420                 return rc;
1421
1422         if (optlen < sizeof(int))
1423                 return rc;
1424         get_user(val, (int __user *)optval);
1425
1426         lock_sock(sk);
1427         switch (optname) {
1428         case TCP_ULP:
1429         case TCP_FASTOPEN:
1430         case TCP_FASTOPEN_CONNECT:
1431         case TCP_FASTOPEN_KEY:
1432         case TCP_FASTOPEN_NO_COOKIE:
1433                 /* option not supported by SMC */
1434                 if (sk->sk_state == SMC_INIT) {
1435                         smc->use_fallback = true;
1436                 } else {
1437                         if (!smc->use_fallback)
1438                                 rc = -EINVAL;
1439                 }
1440                 break;
1441         case TCP_NODELAY:
1442                 if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1443                         if (val && !smc->use_fallback)
1444                                 mod_delayed_work(system_wq, &smc->conn.tx_work,
1445                                                  0);
1446                 }
1447                 break;
1448         case TCP_CORK:
1449                 if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1450                         if (!val && !smc->use_fallback)
1451                                 mod_delayed_work(system_wq, &smc->conn.tx_work,
1452                                                  0);
1453                 }
1454                 break;
1455         case TCP_DEFER_ACCEPT:
1456                 smc->sockopt_defer_accept = val;
1457                 break;
1458         default:
1459                 break;
1460         }
1461         release_sock(sk);
1462
1463         return rc;
1464 }
1465
1466 static int smc_getsockopt(struct socket *sock, int level, int optname,
1467                           char __user *optval, int __user *optlen)
1468 {
1469         struct smc_sock *smc;
1470
1471         smc = smc_sk(sock->sk);
1472         /* socket options apply to the CLC socket */
1473         return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
1474                                              optval, optlen);
1475 }
1476
1477 static int smc_ioctl(struct socket *sock, unsigned int cmd,
1478                      unsigned long arg)
1479 {
1480         union smc_host_cursor cons, urg;
1481         struct smc_connection *conn;
1482         struct smc_sock *smc;
1483         int answ;
1484
1485         smc = smc_sk(sock->sk);
1486         conn = &smc->conn;
1487         if (smc->use_fallback) {
1488                 if (!smc->clcsock)
1489                         return -EBADF;
1490                 return smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
1491         }
1492         switch (cmd) {
1493         case SIOCINQ: /* same as FIONREAD */
1494                 if (smc->sk.sk_state == SMC_LISTEN)
1495                         return -EINVAL;
1496                 if (smc->sk.sk_state == SMC_INIT ||
1497                     smc->sk.sk_state == SMC_CLOSED)
1498                         answ = 0;
1499                 else
1500                         answ = atomic_read(&smc->conn.bytes_to_rcv);
1501                 break;
1502         case SIOCOUTQ:
1503                 /* output queue size (not send + not acked) */
1504                 if (smc->sk.sk_state == SMC_LISTEN)
1505                         return -EINVAL;
1506                 if (smc->sk.sk_state == SMC_INIT ||
1507                     smc->sk.sk_state == SMC_CLOSED)
1508                         answ = 0;
1509                 else
1510                         answ = smc->conn.sndbuf_desc->len -
1511                                         atomic_read(&smc->conn.sndbuf_space);
1512                 break;
1513         case SIOCOUTQNSD:
1514                 /* output queue size (not send only) */
1515                 if (smc->sk.sk_state == SMC_LISTEN)
1516                         return -EINVAL;
1517                 if (smc->sk.sk_state == SMC_INIT ||
1518                     smc->sk.sk_state == SMC_CLOSED)
1519                         answ = 0;
1520                 else
1521                         answ = smc_tx_prepared_sends(&smc->conn);
1522                 break;
1523         case SIOCATMARK:
1524                 if (smc->sk.sk_state == SMC_LISTEN)
1525                         return -EINVAL;
1526                 if (smc->sk.sk_state == SMC_INIT ||
1527                     smc->sk.sk_state == SMC_CLOSED) {
1528                         answ = 0;
1529                 } else {
1530                         smc_curs_write(&cons,
1531                                smc_curs_read(&conn->local_tx_ctrl.cons, conn),
1532                                        conn);
1533                         smc_curs_write(&urg,
1534                                        smc_curs_read(&conn->urg_curs, conn),
1535                                        conn);
1536                         answ = smc_curs_diff(conn->rmb_desc->len,
1537                                              &cons, &urg) == 1;
1538                 }
1539                 break;
1540         default:
1541                 return -ENOIOCTLCMD;
1542         }
1543
1544         return put_user(answ, (int __user *)arg);
1545 }
1546
1547 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
1548                             int offset, size_t size, int flags)
1549 {
1550         struct sock *sk = sock->sk;
1551         struct smc_sock *smc;
1552         int rc = -EPIPE;
1553
1554         smc = smc_sk(sk);
1555         lock_sock(sk);
1556         if (sk->sk_state != SMC_ACTIVE) {
1557                 release_sock(sk);
1558                 goto out;
1559         }
1560         release_sock(sk);
1561         if (smc->use_fallback)
1562                 rc = kernel_sendpage(smc->clcsock, page, offset,
1563                                      size, flags);
1564         else
1565                 rc = sock_no_sendpage(sock, page, offset, size, flags);
1566
1567 out:
1568         return rc;
1569 }
1570
1571 /* Map the affected portions of the rmbe into an spd, note the number of bytes
1572  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
1573  * updates till whenever a respective page has been fully processed.
1574  * Note that subsequent recv() calls have to wait till all splice() processing
1575  * completed.
1576  */
1577 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
1578                                struct pipe_inode_info *pipe, size_t len,
1579                                unsigned int flags)
1580 {
1581         struct sock *sk = sock->sk;
1582         struct smc_sock *smc;
1583         int rc = -ENOTCONN;
1584
1585         smc = smc_sk(sk);
1586         lock_sock(sk);
1587
1588         if (sk->sk_state == SMC_INIT ||
1589             sk->sk_state == SMC_LISTEN ||
1590             sk->sk_state == SMC_CLOSED)
1591                 goto out;
1592
1593         if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1594                 rc = 0;
1595                 goto out;
1596         }
1597
1598         if (smc->use_fallback) {
1599                 rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
1600                                                     pipe, len, flags);
1601         } else {
1602                 if (*ppos) {
1603                         rc = -ESPIPE;
1604                         goto out;
1605                 }
1606                 if (flags & SPLICE_F_NONBLOCK)
1607                         flags = MSG_DONTWAIT;
1608                 else
1609                         flags = 0;
1610                 rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
1611         }
1612 out:
1613         release_sock(sk);
1614
1615         return rc;
1616 }
1617
1618 /* must look like tcp */
1619 static const struct proto_ops smc_sock_ops = {
1620         .family         = PF_SMC,
1621         .owner          = THIS_MODULE,
1622         .release        = smc_release,
1623         .bind           = smc_bind,
1624         .connect        = smc_connect,
1625         .socketpair     = sock_no_socketpair,
1626         .accept         = smc_accept,
1627         .getname        = smc_getname,
1628         .poll           = smc_poll,
1629         .ioctl          = smc_ioctl,
1630         .listen         = smc_listen,
1631         .shutdown       = smc_shutdown,
1632         .setsockopt     = smc_setsockopt,
1633         .getsockopt     = smc_getsockopt,
1634         .sendmsg        = smc_sendmsg,
1635         .recvmsg        = smc_recvmsg,
1636         .mmap           = sock_no_mmap,
1637         .sendpage       = smc_sendpage,
1638         .splice_read    = smc_splice_read,
1639 };
1640
1641 static int smc_create(struct net *net, struct socket *sock, int protocol,
1642                       int kern)
1643 {
1644         int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
1645         struct smc_sock *smc;
1646         struct sock *sk;
1647         int rc;
1648
1649         rc = -ESOCKTNOSUPPORT;
1650         if (sock->type != SOCK_STREAM)
1651                 goto out;
1652
1653         rc = -EPROTONOSUPPORT;
1654         if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
1655                 goto out;
1656
1657         rc = -ENOBUFS;
1658         sock->ops = &smc_sock_ops;
1659         sk = smc_sock_alloc(net, sock, protocol);
1660         if (!sk)
1661                 goto out;
1662
1663         /* create internal TCP socket for CLC handshake and fallback */
1664         smc = smc_sk(sk);
1665         smc->use_fallback = false; /* assume rdma capability first */
1666         rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
1667                               &smc->clcsock);
1668         if (rc) {
1669                 sk_common_release(sk);
1670                 goto out;
1671         }
1672         smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
1673         smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
1674
1675 out:
1676         return rc;
1677 }
1678
1679 static const struct net_proto_family smc_sock_family_ops = {
1680         .family = PF_SMC,
1681         .owner  = THIS_MODULE,
1682         .create = smc_create,
1683 };
1684
1685 static int __init smc_init(void)
1686 {
1687         int rc;
1688
1689         rc = smc_pnet_init();
1690         if (rc)
1691                 return rc;
1692
1693         rc = smc_llc_init();
1694         if (rc) {
1695                 pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
1696                 goto out_pnet;
1697         }
1698
1699         rc = smc_cdc_init();
1700         if (rc) {
1701                 pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
1702                 goto out_pnet;
1703         }
1704
1705         rc = proto_register(&smc_proto, 1);
1706         if (rc) {
1707                 pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
1708                 goto out_pnet;
1709         }
1710
1711         rc = proto_register(&smc_proto6, 1);
1712         if (rc) {
1713                 pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
1714                 goto out_proto;
1715         }
1716
1717         rc = sock_register(&smc_sock_family_ops);
1718         if (rc) {
1719                 pr_err("%s: sock_register fails with %d\n", __func__, rc);
1720                 goto out_proto6;
1721         }
1722         INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
1723         INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
1724
1725         rc = smc_ib_register_client();
1726         if (rc) {
1727                 pr_err("%s: ib_register fails with %d\n", __func__, rc);
1728                 goto out_sock;
1729         }
1730
1731         static_branch_enable(&tcp_have_smc);
1732         return 0;
1733
1734 out_sock:
1735         sock_unregister(PF_SMC);
1736 out_proto6:
1737         proto_unregister(&smc_proto6);
1738 out_proto:
1739         proto_unregister(&smc_proto);
1740 out_pnet:
1741         smc_pnet_exit();
1742         return rc;
1743 }
1744
1745 static void __exit smc_exit(void)
1746 {
1747         smc_core_exit();
1748         static_branch_disable(&tcp_have_smc);
1749         smc_ib_unregister_client();
1750         sock_unregister(PF_SMC);
1751         proto_unregister(&smc_proto6);
1752         proto_unregister(&smc_proto);
1753         smc_pnet_exit();
1754 }
1755
1756 module_init(smc_init);
1757 module_exit(smc_exit);
1758
1759 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
1760 MODULE_DESCRIPTION("smc socket address family");
1761 MODULE_LICENSE("GPL");
1762 MODULE_ALIAS_NETPROTO(PF_SMC);