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  *    - non-blocking connect postponed
  11  *    - IPv6 support postponed
  12  *    - support for alternate links postponed
  13  *    - partial support for non-blocking sockets only
  14  *    - support for urgent data postponed
  15  *
  16  *  Copyright IBM Corp. 2016
  17  *
  18  *  Author(s):  Ursula Braun <[email protected]>
  19  *              based on prototype from Frank Blaschka
  20  */
  21
  22 #define KMSG_COMPONENT "smc"
  23 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  24
  25 #include <linux/module.h>
  26 #include <linux/socket.h>
  27 #include <linux/inetdevice.h>
  28 #include <linux/workqueue.h>
  29 #include <linux/in.h>
  30 #include <linux/sched/signal.h>
  31
  32 #include <net/sock.h>
  33 #include <net/tcp.h>
  34 #include <net/smc.h>
  35
  36 #include "smc.h"
  37 #include "smc_clc.h"
  38 #include "smc_llc.h"
  39 #include "smc_cdc.h"
  40 #include "smc_core.h"
  41 #include "smc_ib.h"
  42 #include "smc_pnet.h"
  43 #include "smc_tx.h"
  44 #include "smc_rx.h"
  45 #include "smc_close.h"
  46
  47 static DEFINE_MUTEX(smc_create_lgr_pending);    /* serialize link group
  48                                                  * creation
  49                                                  */
  50
  51 struct smc_lgr_list smc_lgr_list = {            /* established link groups */
  52         .lock = __SPIN_LOCK_UNLOCKED(smc_lgr_list.lock),
  53         .list = LIST_HEAD_INIT(smc_lgr_list.list),
  54 };
  55
  56 static void smc_tcp_listen_work(struct work_struct *);
  57
  58 static void smc_set_keepalive(struct sock *sk, int val)
  59 {
  60         struct smc_sock *smc = smc_sk(sk);
  61
  62         smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
  63 }
  64
  65 static struct smc_hashinfo smc_v4_hashinfo = {
  66         .lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
  67 };
  68
  69 int smc_hash_sk(struct sock *sk)
  70 {
  71         struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
  72         struct hlist_head *head;
  73
  74         head = &h->ht;
  75
  76         write_lock_bh(&h->lock);
  77         sk_add_node(sk, head);
  78         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
  79         write_unlock_bh(&h->lock);
  80
  81         return 0;
  82 }
  83 EXPORT_SYMBOL_GPL(smc_hash_sk);
  84
  85 void smc_unhash_sk(struct sock *sk)
  86 {
  87         struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
  88
  89         write_lock_bh(&h->lock);
  90         if (sk_del_node_init(sk))
  91                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
  92         write_unlock_bh(&h->lock);
  93 }
  94 EXPORT_SYMBOL_GPL(smc_unhash_sk);
  95
  96 struct proto smc_proto = {
  97         .name           = "SMC",
  98         .owner          = THIS_MODULE,
  99         .keepalive      = smc_set_keepalive,
 100         .hash           = smc_hash_sk,
 101         .unhash         = smc_unhash_sk,
 102         .obj_size       = sizeof(struct smc_sock),
 103         .h.smc_hash     = &smc_v4_hashinfo,
 104         .slab_flags     = SLAB_TYPESAFE_BY_RCU,
 105 };
 106 EXPORT_SYMBOL_GPL(smc_proto);
 107
 108 static int smc_release(struct socket *sock)
 109 {
 110         struct sock *sk = sock->sk;
 111         struct smc_sock *smc;
 112         int rc = 0;
 113
 114         if (!sk)
 115                 goto out;
 116
 117         smc = smc_sk(sk);
 118         sock_hold(sk);
 119         if (sk->sk_state == SMC_LISTEN)
 120                 /* smc_close_non_accepted() is called and acquires
 121                  * sock lock for child sockets again
 122                  */
 123                 lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 124         else
 125                 lock_sock(sk);
 126
 127         if (smc->use_fallback) {
 128                 sk->sk_state = SMC_CLOSED;
 129                 sk->sk_state_change(sk);
 130         } else {
 131                 rc = smc_close_active(smc);
 132                 sock_set_flag(sk, SOCK_DEAD);
 133                 sk->sk_shutdown |= SHUTDOWN_MASK;
 134         }
 135         if (smc->clcsock) {
 136                 sock_release(smc->clcsock);
 137                 smc->clcsock = NULL;
 138         }
 139
 140         /* detach socket */
 141         sock_orphan(sk);
 142         sock->sk = NULL;
 143         if (smc->use_fallback) {
 144                 schedule_delayed_work(&smc->sock_put_work, TCP_TIMEWAIT_LEN);
 145         } else if (sk->sk_state == SMC_CLOSED) {
 146                 smc_conn_free(&smc->conn);
 147                 schedule_delayed_work(&smc->sock_put_work,
 148                                       SMC_CLOSE_SOCK_PUT_DELAY);
 149         }
 150         release_sock(sk);
 151
 152         sock_put(sk);
 153 out:
 154         return rc;
 155 }
 156
 157 static void smc_destruct(struct sock *sk)
 158 {
 159         if (sk->sk_state != SMC_CLOSED)
 160                 return;
 161         if (!sock_flag(sk, SOCK_DEAD))
 162                 return;
 163
 164         sk_refcnt_debug_dec(sk);
 165 }
 166
 167 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock)
 168 {
 169         struct smc_sock *smc;
 170         struct sock *sk;
 171
 172         sk = sk_alloc(net, PF_SMC, GFP_KERNEL, &smc_proto, 0);
 173         if (!sk)
 174                 return NULL;
 175
 176         sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
 177         sk->sk_state = SMC_INIT;
 178         sk->sk_destruct = smc_destruct;
 179         sk->sk_protocol = SMCPROTO_SMC;
 180         smc = smc_sk(sk);
 181         INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
 182         INIT_LIST_HEAD(&smc->accept_q);
 183         spin_lock_init(&smc->accept_q_lock);
 184         INIT_DELAYED_WORK(&smc->sock_put_work, smc_close_sock_put_work);
 185         sk->sk_prot->hash(sk);
 186         sk_refcnt_debug_inc(sk);
 187
 188         return sk;
 189 }
 190
 191 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
 192                     int addr_len)
 193 {
 194         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
 195         struct sock *sk = sock->sk;
 196         struct smc_sock *smc;
 197         int rc;
 198
 199         smc = smc_sk(sk);
 200
 201         /* replicate tests from inet_bind(), to be safe wrt. future changes */
 202         rc = -EINVAL;
 203         if (addr_len < sizeof(struct sockaddr_in))
 204                 goto out;
 205
 206         rc = -EAFNOSUPPORT;
 207         /* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
 208         if ((addr->sin_family != AF_INET) &&
 209             ((addr->sin_family != AF_UNSPEC) ||
 210              (addr->sin_addr.s_addr != htonl(INADDR_ANY))))
 211                 goto out;
 212
 213         lock_sock(sk);
 214
 215         /* Check if socket is already active */
 216         rc = -EINVAL;
 217         if (sk->sk_state != SMC_INIT)
 218                 goto out_rel;
 219
 220         smc->clcsock->sk->sk_reuse = sk->sk_reuse;
 221         rc = kernel_bind(smc->clcsock, uaddr, addr_len);
 222
 223 out_rel:
 224         release_sock(sk);
 225 out:
 226         return rc;
 227 }
 228
 229 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
 230                                    unsigned long mask)
 231 {
 232         /* options we don't get control via setsockopt for */
 233         nsk->sk_type = osk->sk_type;
 234         nsk->sk_sndbuf = osk->sk_sndbuf;
 235         nsk->sk_rcvbuf = osk->sk_rcvbuf;
 236         nsk->sk_sndtimeo = osk->sk_sndtimeo;
 237         nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
 238         nsk->sk_mark = osk->sk_mark;
 239         nsk->sk_priority = osk->sk_priority;
 240         nsk->sk_rcvlowat = osk->sk_rcvlowat;
 241         nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
 242         nsk->sk_err = osk->sk_err;
 243
 244         nsk->sk_flags &= ~mask;
 245         nsk->sk_flags |= osk->sk_flags & mask;
 246 }
 247
 248 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
 249                              (1UL << SOCK_KEEPOPEN) | \
 250                              (1UL << SOCK_LINGER) | \
 251                              (1UL << SOCK_BROADCAST) | \
 252                              (1UL << SOCK_TIMESTAMP) | \
 253                              (1UL << SOCK_DBG) | \
 254                              (1UL << SOCK_RCVTSTAMP) | \
 255                              (1UL << SOCK_RCVTSTAMPNS) | \
 256                              (1UL << SOCK_LOCALROUTE) | \
 257                              (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
 258                              (1UL << SOCK_RXQ_OVFL) | \
 259                              (1UL << SOCK_WIFI_STATUS) | \
 260                              (1UL << SOCK_NOFCS) | \
 261                              (1UL << SOCK_FILTER_LOCKED))
 262 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
 263  * clc socket (since smc is not called for these options from net/core)
 264  */
 265 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
 266 {
 267         smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
 268 }
 269
 270 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
 271                              (1UL << SOCK_KEEPOPEN) | \
 272                              (1UL << SOCK_LINGER) | \
 273                              (1UL << SOCK_DBG))
 274 /* copy only settings and flags relevant for smc from clc to smc socket */
 275 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
 276 {
 277         smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
 278 }
 279
 280 /* determine subnet and mask of internal TCP socket */
 281 int smc_netinfo_by_tcpsk(struct socket *clcsock,
 282                          __be32 *subnet, u8 *prefix_len)
 283 {
 284         struct dst_entry *dst = sk_dst_get(clcsock->sk);
 285         struct in_device *in_dev;
 286         struct sockaddr_in addr;
 287         int rc = -ENOENT;
 288         int len;
 289
 290         if (!dst) {
 291                 rc = -ENOTCONN;
 292                 goto out;
 293         }
 294         if (!dst->dev) {
 295                 rc = -ENODEV;
 296                 goto out_rel;
 297         }
 298
 299         /* get address to which the internal TCP socket is bound */
 300         kernel_getsockname(clcsock, (struct sockaddr *)&addr, &len);
 301         /* analyze IPv4 specific data of net_device belonging to TCP socket */
 302         rcu_read_lock();
 303         in_dev = __in_dev_get_rcu(dst->dev);
 304         for_ifa(in_dev) {
 305                 if (!inet_ifa_match(addr.sin_addr.s_addr, ifa))
 306                         continue;
 307                 *prefix_len = inet_mask_len(ifa->ifa_mask);
 308                 *subnet = ifa->ifa_address & ifa->ifa_mask;
 309                 rc = 0;
 310                 break;
 311         } endfor_ifa(in_dev);
 312         rcu_read_unlock();
 313
 314 out_rel:
 315         dst_release(dst);
 316 out:
 317         return rc;
 318 }
 319
 320 static int smc_clnt_conf_first_link(struct smc_sock *smc, union ib_gid *gid)
 321 {
 322         struct smc_link_group *lgr = smc->conn.lgr;
 323         struct smc_link *link;
 324         int rest;
 325         int rc;
 326
 327         link = &lgr->lnk[SMC_SINGLE_LINK];
 328         /* receive CONFIRM LINK request from server over RoCE fabric */
 329         rest = wait_for_completion_interruptible_timeout(
 330                 &link->llc_confirm,
 331                 SMC_LLC_WAIT_FIRST_TIME);
 332         if (rest <= 0) {
 333                 struct smc_clc_msg_decline dclc;
 334
 335                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
 336                                       SMC_CLC_DECLINE);
 337                 return rc;
 338         }
 339
 340         rc = smc_ib_modify_qp_rts(link);
 341         if (rc)
 342                 return SMC_CLC_DECL_INTERR;
 343
 344         smc_wr_remember_qp_attr(link);
 345
 346         rc = smc_wr_reg_send(link,
 347                              smc->conn.rmb_desc->mr_rx[SMC_SINGLE_LINK]);
 348         if (rc)
 349                 return SMC_CLC_DECL_INTERR;
 350
 351         /* send CONFIRM LINK response over RoCE fabric */
 352         rc = smc_llc_send_confirm_link(link,
 353                                        link->smcibdev->mac[link->ibport - 1],
 354                                        gid, SMC_LLC_RESP);
 355         if (rc < 0)
 356                 return SMC_CLC_DECL_TCL;
 357
 358         return rc;
 359 }
 360
 361 static void smc_conn_save_peer_info(struct smc_sock *smc,
 362                                     struct smc_clc_msg_accept_confirm *clc)
 363 {
 364         smc->conn.peer_conn_idx = clc->conn_idx;
 365         smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
 366         smc->conn.peer_rmbe_size = smc_uncompress_bufsize(clc->rmbe_size);
 367         atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
 368 }
 369
 370 static void smc_link_save_peer_info(struct smc_link *link,
 371                                     struct smc_clc_msg_accept_confirm *clc)
 372 {
 373         link->peer_qpn = ntoh24(clc->qpn);
 374         memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
 375         memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
 376         link->peer_psn = ntoh24(clc->psn);
 377         link->peer_mtu = clc->qp_mtu;
 378 }
 379
 380 /* setup for RDMA connection of client */
 381 static int smc_connect_rdma(struct smc_sock *smc)
 382 {
 383         struct sockaddr_in *inaddr = (struct sockaddr_in *)smc->addr;
 384         struct smc_clc_msg_accept_confirm aclc;
 385         int local_contact = SMC_FIRST_CONTACT;
 386         struct smc_ib_device *smcibdev;
 387         struct smc_link *link;
 388         u8 srv_first_contact;
 389         int reason_code = 0;
 390         int rc = 0;
 391         u8 ibport;
 392
 393         /* IPSec connections opt out of SMC-R optimizations */
 394         if (using_ipsec(smc)) {
 395                 reason_code = SMC_CLC_DECL_IPSEC;
 396                 goto decline_rdma;
 397         }
 398
 399         /* PNET table look up: search active ib_device and port
 400          * within same PNETID that also contains the ethernet device
 401          * used for the internal TCP socket
 402          */
 403         smc_pnet_find_roce_resource(smc->clcsock->sk, &smcibdev, &ibport);
 404         if (!smcibdev) {
 405                 reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
 406                 goto decline_rdma;
 407         }
 408
 409         /* do inband token exchange */
 410         reason_code = smc_clc_send_proposal(smc, smcibdev, ibport);
 411         if (reason_code < 0) {
 412                 rc = reason_code;
 413                 goto out_err;
 414         }
 415         if (reason_code > 0) /* configuration error */
 416                 goto decline_rdma;
 417         /* receive SMC Accept CLC message */
 418         reason_code = smc_clc_wait_msg(smc, &aclc, sizeof(aclc),
 419                                        SMC_CLC_ACCEPT);
 420         if (reason_code < 0) {
 421                 rc = reason_code;
 422                 goto out_err;
 423         }
 424         if (reason_code > 0)
 425                 goto decline_rdma;
 426
 427         srv_first_contact = aclc.hdr.flag;
 428         mutex_lock(&smc_create_lgr_pending);
 429         local_contact = smc_conn_create(smc, inaddr->sin_addr.s_addr, smcibdev,
 430                                         ibport, &aclc.lcl, srv_first_contact);
 431         if (local_contact < 0) {
 432                 rc = local_contact;
 433                 if (rc == -ENOMEM)
 434                         reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
 435                 else if (rc == -ENOLINK)
 436                         reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
 437                 goto decline_rdma_unlock;
 438         }
 439         link = &smc->conn.lgr->lnk[SMC_SINGLE_LINK];
 440
 441         smc_conn_save_peer_info(smc, &aclc);
 442
 443         /* create send buffer and rmb */
 444         rc = smc_buf_create(smc);
 445         if (rc) {
 446                 reason_code = SMC_CLC_DECL_MEM;
 447                 goto decline_rdma_unlock;
 448         }
 449
 450         if (local_contact == SMC_FIRST_CONTACT)
 451                 smc_link_save_peer_info(link, &aclc);
 452
 453         rc = smc_rmb_rtoken_handling(&smc->conn, &aclc);
 454         if (rc) {
 455                 reason_code = SMC_CLC_DECL_INTERR;
 456                 goto decline_rdma_unlock;
 457         }
 458
 459         smc_close_init(smc);
 460         smc_rx_init(smc);
 461
 462         if (local_contact == SMC_FIRST_CONTACT) {
 463                 rc = smc_ib_ready_link(link);
 464                 if (rc) {
 465                         reason_code = SMC_CLC_DECL_INTERR;
 466                         goto decline_rdma_unlock;
 467                 }
 468         } else {
 469                 struct smc_buf_desc *buf_desc = smc->conn.rmb_desc;
 470
 471                 if (!buf_desc->reused) {
 472                         /* register memory region for new rmb */
 473                         rc = smc_wr_reg_send(link,
 474                                              buf_desc->mr_rx[SMC_SINGLE_LINK]);
 475                         if (rc) {
 476                                 reason_code = SMC_CLC_DECL_INTERR;
 477                                 goto decline_rdma_unlock;
 478                         }
 479                 }
 480         }
 481         smc_rmb_sync_sg_for_device(&smc->conn);
 482
 483         rc = smc_clc_send_confirm(smc);
 484         if (rc)
 485                 goto out_err_unlock;
 486
 487         if (local_contact == SMC_FIRST_CONTACT) {
 488                 /* QP confirmation over RoCE fabric */
 489                 reason_code = smc_clnt_conf_first_link(
 490                         smc, &smcibdev->gid[ibport - 1]);
 491                 if (reason_code < 0) {
 492                         rc = reason_code;
 493                         goto out_err_unlock;
 494                 }
 495                 if (reason_code > 0)
 496                         goto decline_rdma_unlock;
 497         }
 498
 499         mutex_unlock(&smc_create_lgr_pending);
 500         smc_tx_init(smc);
 501
 502 out_connected:
 503         smc_copy_sock_settings_to_clc(smc);
 504         if (smc->sk.sk_state == SMC_INIT)
 505                 smc->sk.sk_state = SMC_ACTIVE;
 506
 507         return rc ? rc : local_contact;
 508
 509 decline_rdma_unlock:
 510         mutex_unlock(&smc_create_lgr_pending);
 511         smc_conn_free(&smc->conn);
 512 decline_rdma:
 513         /* RDMA setup failed, switch back to TCP */
 514         smc->use_fallback = true;
 515         if (reason_code && (reason_code != SMC_CLC_DECL_REPLY)) {
 516                 rc = smc_clc_send_decline(smc, reason_code);
 517                 if (rc < sizeof(struct smc_clc_msg_decline))
 518                         goto out_err;
 519         }
 520         goto out_connected;
 521
 522 out_err_unlock:
 523         mutex_unlock(&smc_create_lgr_pending);
 524         smc_conn_free(&smc->conn);
 525 out_err:
 526         return rc;
 527 }
 528
 529 static int smc_connect(struct socket *sock, struct sockaddr *addr,
 530                        int alen, int flags)
 531 {
 532         struct sock *sk = sock->sk;
 533         struct smc_sock *smc;
 534         int rc = -EINVAL;
 535
 536         smc = smc_sk(sk);
 537
 538         /* separate smc parameter checking to be safe */
 539         if (alen < sizeof(addr->sa_family))
 540                 goto out_err;
 541         if (addr->sa_family != AF_INET)
 542                 goto out_err;
 543         smc->addr = addr;       /* needed for nonblocking connect */
 544
 545         lock_sock(sk);
 546         switch (sk->sk_state) {
 547         default:
 548                 goto out;
 549         case SMC_ACTIVE:
 550                 rc = -EISCONN;
 551                 goto out;
 552         case SMC_INIT:
 553                 rc = 0;
 554                 break;
 555         }
 556
 557         smc_copy_sock_settings_to_clc(smc);
 558         rc = kernel_connect(smc->clcsock, addr, alen, flags);
 559         if (rc)
 560                 goto out;
 561
 562         /* setup RDMA connection */
 563         rc = smc_connect_rdma(smc);
 564         if (rc < 0)
 565                 goto out;
 566         else
 567                 rc = 0; /* success cases including fallback */
 568
 569 out:
 570         release_sock(sk);
 571 out_err:
 572         return rc;
 573 }
 574
 575 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
 576 {
 577         struct sock *sk = &lsmc->sk;
 578         struct socket *new_clcsock;
 579         struct sock *new_sk;
 580         int rc;
 581
 582         release_sock(&lsmc->sk);
 583         new_sk = smc_sock_alloc(sock_net(sk), NULL);
 584         if (!new_sk) {
 585                 rc = -ENOMEM;
 586                 lsmc->sk.sk_err = ENOMEM;
 587                 *new_smc = NULL;
 588                 lock_sock(&lsmc->sk);
 589                 goto out;
 590         }
 591         *new_smc = smc_sk(new_sk);
 592
 593         rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
 594         lock_sock(&lsmc->sk);
 595         if  (rc < 0) {
 596                 lsmc->sk.sk_err = -rc;
 597                 new_sk->sk_state = SMC_CLOSED;
 598                 sock_set_flag(new_sk, SOCK_DEAD);
 599                 sk->sk_prot->unhash(new_sk);
 600                 sock_put(new_sk);
 601                 *new_smc = NULL;
 602                 goto out;
 603         }
 604         if (lsmc->sk.sk_state == SMC_CLOSED) {
 605                 if (new_clcsock)
 606                         sock_release(new_clcsock);
 607                 new_sk->sk_state = SMC_CLOSED;
 608                 sock_set_flag(new_sk, SOCK_DEAD);
 609                 sk->sk_prot->unhash(new_sk);
 610                 sock_put(new_sk);
 611                 *new_smc = NULL;
 612                 goto out;
 613         }
 614
 615         (*new_smc)->clcsock = new_clcsock;
 616 out:
 617         return rc;
 618 }
 619
 620 /* add a just created sock to the accept queue of the listen sock as
 621  * candidate for a following socket accept call from user space
 622  */
 623 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
 624 {
 625         struct smc_sock *par = smc_sk(parent);
 626
 627         sock_hold(sk);
 628         spin_lock(&par->accept_q_lock);
 629         list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
 630         spin_unlock(&par->accept_q_lock);
 631         sk_acceptq_added(parent);
 632 }
 633
 634 /* remove a socket from the accept queue of its parental listening socket */
 635 static void smc_accept_unlink(struct sock *sk)
 636 {
 637         struct smc_sock *par = smc_sk(sk)->listen_smc;
 638
 639         spin_lock(&par->accept_q_lock);
 640         list_del_init(&smc_sk(sk)->accept_q);
 641         spin_unlock(&par->accept_q_lock);
 642         sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
 643         sock_put(sk);
 644 }
 645
 646 /* remove a sock from the accept queue to bind it to a new socket created
 647  * for a socket accept call from user space
 648  */
 649 struct sock *smc_accept_dequeue(struct sock *parent,
 650                                 struct socket *new_sock)
 651 {
 652         struct smc_sock *isk, *n;
 653         struct sock *new_sk;
 654
 655         list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
 656                 new_sk = (struct sock *)isk;
 657
 658                 smc_accept_unlink(new_sk);
 659                 if (new_sk->sk_state == SMC_CLOSED) {
 660                         new_sk->sk_prot->unhash(new_sk);
 661                         sock_put(new_sk);
 662                         continue;
 663                 }
 664                 if (new_sock)
 665                         sock_graft(new_sk, new_sock);
 666                 return new_sk;
 667         }
 668         return NULL;
 669 }
 670
 671 /* clean up for a created but never accepted sock */
 672 void smc_close_non_accepted(struct sock *sk)
 673 {
 674         struct smc_sock *smc = smc_sk(sk);
 675
 676         sock_hold(sk);
 677         lock_sock(sk);
 678         if (!sk->sk_lingertime)
 679                 /* wait for peer closing */
 680                 sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
 681         if (smc->use_fallback) {
 682                 sk->sk_state = SMC_CLOSED;
 683         } else {
 684                 smc_close_active(smc);
 685                 sock_set_flag(sk, SOCK_DEAD);
 686                 sk->sk_shutdown |= SHUTDOWN_MASK;
 687         }
 688         if (smc->clcsock) {
 689                 struct socket *tcp;
 690
 691                 tcp = smc->clcsock;
 692                 smc->clcsock = NULL;
 693                 sock_release(tcp);
 694         }
 695         if (smc->use_fallback) {
 696                 schedule_delayed_work(&smc->sock_put_work, TCP_TIMEWAIT_LEN);
 697         } else if (sk->sk_state == SMC_CLOSED) {
 698                 smc_conn_free(&smc->conn);
 699                 schedule_delayed_work(&smc->sock_put_work,
 700                                       SMC_CLOSE_SOCK_PUT_DELAY);
 701         }
 702         release_sock(sk);
 703         sock_put(sk);
 704 }
 705
 706 static int smc_serv_conf_first_link(struct smc_sock *smc)
 707 {
 708         struct smc_link_group *lgr = smc->conn.lgr;
 709         struct smc_link *link;
 710         int rest;
 711         int rc;
 712
 713         link = &lgr->lnk[SMC_SINGLE_LINK];
 714
 715         rc = smc_wr_reg_send(link,
 716                              smc->conn.rmb_desc->mr_rx[SMC_SINGLE_LINK]);
 717         if (rc)
 718                 return SMC_CLC_DECL_INTERR;
 719
 720         /* send CONFIRM LINK request to client over the RoCE fabric */
 721         rc = smc_llc_send_confirm_link(link,
 722                                        link->smcibdev->mac[link->ibport - 1],
 723                                        &link->smcibdev->gid[link->ibport - 1],
 724                                        SMC_LLC_REQ);
 725         if (rc < 0)
 726                 return SMC_CLC_DECL_TCL;
 727
 728         /* receive CONFIRM LINK response from client over the RoCE fabric */
 729         rest = wait_for_completion_interruptible_timeout(
 730                 &link->llc_confirm_resp,
 731                 SMC_LLC_WAIT_FIRST_TIME);
 732         if (rest <= 0) {
 733                 struct smc_clc_msg_decline dclc;
 734
 735                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
 736                                       SMC_CLC_DECLINE);
 737         }
 738
 739         return rc;
 740 }
 741
 742 /* setup for RDMA connection of server */
 743 static void smc_listen_work(struct work_struct *work)
 744 {
 745         struct smc_sock *new_smc = container_of(work, struct smc_sock,
 746                                                 smc_listen_work);
 747         struct socket *newclcsock = new_smc->clcsock;
 748         struct smc_sock *lsmc = new_smc->listen_smc;
 749         struct smc_clc_msg_accept_confirm cclc;
 750         int local_contact = SMC_REUSE_CONTACT;
 751         struct sock *newsmcsk = &new_smc->sk;
 752         struct smc_clc_msg_proposal pclc;
 753         struct smc_ib_device *smcibdev;
 754         struct sockaddr_in peeraddr;
 755         struct smc_link *link;
 756         int reason_code = 0;
 757         int rc = 0, len;
 758         __be32 subnet;
 759         u8 prefix_len;
 760         u8 ibport;
 761
 762         /* do inband token exchange -
 763          *wait for and receive SMC Proposal CLC message
 764          */
 765         reason_code = smc_clc_wait_msg(new_smc, &pclc, sizeof(pclc),
 766                                        SMC_CLC_PROPOSAL);
 767         if (reason_code < 0)
 768                 goto out_err;
 769         if (reason_code > 0)
 770                 goto decline_rdma;
 771
 772         /* IPSec connections opt out of SMC-R optimizations */
 773         if (using_ipsec(new_smc)) {
 774                 reason_code = SMC_CLC_DECL_IPSEC;
 775                 goto decline_rdma;
 776         }
 777
 778         /* PNET table look up: search active ib_device and port
 779          * within same PNETID that also contains the ethernet device
 780          * used for the internal TCP socket
 781          */
 782         smc_pnet_find_roce_resource(newclcsock->sk, &smcibdev, &ibport);
 783         if (!smcibdev) {
 784                 reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
 785                 goto decline_rdma;
 786         }
 787
 788         /* determine subnet and mask from internal TCP socket */
 789         rc = smc_netinfo_by_tcpsk(newclcsock, &subnet, &prefix_len);
 790         if (rc) {
 791                 reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
 792                 goto decline_rdma;
 793         }
 794         if ((pclc.outgoing_subnet != subnet) ||
 795             (pclc.prefix_len != prefix_len)) {
 796                 reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
 797                 goto decline_rdma;
 798         }
 799
 800         /* get address of the peer connected to the internal TCP socket */
 801         kernel_getpeername(newclcsock, (struct sockaddr *)&peeraddr, &len);
 802
 803         /* allocate connection / link group */
 804         mutex_lock(&smc_create_lgr_pending);
 805         local_contact = smc_conn_create(new_smc, peeraddr.sin_addr.s_addr,
 806                                         smcibdev, ibport, &pclc.lcl, 0);
 807         if (local_contact < 0) {
 808                 rc = local_contact;
 809                 if (rc == -ENOMEM)
 810                         reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
 811                 goto decline_rdma;
 812         }
 813         link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
 814
 815         /* create send buffer and rmb */
 816         rc = smc_buf_create(new_smc);
 817         if (rc) {
 818                 reason_code = SMC_CLC_DECL_MEM;
 819                 goto decline_rdma;
 820         }
 821
 822         smc_close_init(new_smc);
 823         smc_rx_init(new_smc);
 824
 825         if (local_contact != SMC_FIRST_CONTACT) {
 826                 struct smc_buf_desc *buf_desc = new_smc->conn.rmb_desc;
 827
 828                 if (!buf_desc->reused) {
 829                         /* register memory region for new rmb */
 830                         rc = smc_wr_reg_send(link,
 831                                              buf_desc->mr_rx[SMC_SINGLE_LINK]);
 832                         if (rc) {
 833                                 reason_code = SMC_CLC_DECL_INTERR;
 834                                 goto decline_rdma;
 835                         }
 836                 }
 837         }
 838         smc_rmb_sync_sg_for_device(&new_smc->conn);
 839
 840         rc = smc_clc_send_accept(new_smc, local_contact);
 841         if (rc)
 842                 goto out_err;
 843
 844         /* receive SMC Confirm CLC message */
 845         reason_code = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
 846                                        SMC_CLC_CONFIRM);
 847         if (reason_code < 0)
 848                 goto out_err;
 849         if (reason_code > 0)
 850                 goto decline_rdma;
 851         smc_conn_save_peer_info(new_smc, &cclc);
 852         if (local_contact == SMC_FIRST_CONTACT)
 853                 smc_link_save_peer_info(link, &cclc);
 854
 855         rc = smc_rmb_rtoken_handling(&new_smc->conn, &cclc);
 856         if (rc) {
 857                 reason_code = SMC_CLC_DECL_INTERR;
 858                 goto decline_rdma;
 859         }
 860
 861         if (local_contact == SMC_FIRST_CONTACT) {
 862                 rc = smc_ib_ready_link(link);
 863                 if (rc) {
 864                         reason_code = SMC_CLC_DECL_INTERR;
 865                         goto decline_rdma;
 866                 }
 867                 /* QP confirmation over RoCE fabric */
 868                 reason_code = smc_serv_conf_first_link(new_smc);
 869                 if (reason_code < 0) {
 870                         /* peer is not aware of a problem */
 871                         rc = reason_code;
 872                         goto out_err;
 873                 }
 874                 if (reason_code > 0)
 875                         goto decline_rdma;
 876         }
 877
 878         smc_tx_init(new_smc);
 879
 880 out_connected:
 881         sk_refcnt_debug_inc(newsmcsk);
 882         if (newsmcsk->sk_state == SMC_INIT)
 883                 newsmcsk->sk_state = SMC_ACTIVE;
 884 enqueue:
 885         mutex_unlock(&smc_create_lgr_pending);
 886         lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
 887         if (lsmc->sk.sk_state == SMC_LISTEN) {
 888                 smc_accept_enqueue(&lsmc->sk, newsmcsk);
 889         } else { /* no longer listening */
 890                 smc_close_non_accepted(newsmcsk);
 891         }
 892         release_sock(&lsmc->sk);
 893
 894         /* Wake up accept */
 895         lsmc->sk.sk_data_ready(&lsmc->sk);
 896         sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
 897         return;
 898
 899 decline_rdma:
 900         /* RDMA setup failed, switch back to TCP */
 901         smc_conn_free(&new_smc->conn);
 902         new_smc->use_fallback = true;
 903         if (reason_code && (reason_code != SMC_CLC_DECL_REPLY)) {
 904                 rc = smc_clc_send_decline(new_smc, reason_code);
 905                 if (rc < sizeof(struct smc_clc_msg_decline))
 906                         goto out_err;
 907         }
 908         goto out_connected;
 909
 910 out_err:
 911         newsmcsk->sk_state = SMC_CLOSED;
 912         smc_conn_free(&new_smc->conn);
 913         goto enqueue; /* queue new sock with sk_err set */
 914 }
 915
 916 static void smc_tcp_listen_work(struct work_struct *work)
 917 {
 918         struct smc_sock *lsmc = container_of(work, struct smc_sock,
 919                                              tcp_listen_work);
 920         struct smc_sock *new_smc;
 921         int rc = 0;
 922
 923         lock_sock(&lsmc->sk);
 924         while (lsmc->sk.sk_state == SMC_LISTEN) {
 925                 rc = smc_clcsock_accept(lsmc, &new_smc);
 926                 if (rc)
 927                         goto out;
 928                 if (!new_smc)
 929                         continue;
 930
 931                 new_smc->listen_smc = lsmc;
 932                 new_smc->use_fallback = false; /* assume rdma capability first*/
 933                 sock_hold(&lsmc->sk); /* sock_put in smc_listen_work */
 934                 INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
 935                 smc_copy_sock_settings_to_smc(new_smc);
 936                 schedule_work(&new_smc->smc_listen_work);
 937         }
 938
 939 out:
 940         release_sock(&lsmc->sk);
 941         lsmc->sk.sk_data_ready(&lsmc->sk); /* no more listening, wake accept */
 942 }
 943
 944 static int smc_listen(struct socket *sock, int backlog)
 945 {
 946         struct sock *sk = sock->sk;
 947         struct smc_sock *smc;
 948         int rc;
 949
 950         smc = smc_sk(sk);
 951         lock_sock(sk);
 952
 953         rc = -EINVAL;
 954         if ((sk->sk_state != SMC_INIT) && (sk->sk_state != SMC_LISTEN))
 955                 goto out;
 956
 957         rc = 0;
 958         if (sk->sk_state == SMC_LISTEN) {
 959                 sk->sk_max_ack_backlog = backlog;
 960                 goto out;
 961         }
 962         /* some socket options are handled in core, so we could not apply
 963          * them to the clc socket -- copy smc socket options to clc socket
 964          */
 965         smc_copy_sock_settings_to_clc(smc);
 966
 967         rc = kernel_listen(smc->clcsock, backlog);
 968         if (rc)
 969                 goto out;
 970         sk->sk_max_ack_backlog = backlog;
 971         sk->sk_ack_backlog = 0;
 972         sk->sk_state = SMC_LISTEN;
 973         INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
 974         schedule_work(&smc->tcp_listen_work);
 975
 976 out:
 977         release_sock(sk);
 978         return rc;
 979 }
 980
 981 static int smc_accept(struct socket *sock, struct socket *new_sock,
 982                       int flags, bool kern)
 983 {
 984         struct sock *sk = sock->sk, *nsk;
 985         DECLARE_WAITQUEUE(wait, current);
 986         struct smc_sock *lsmc;
 987         long timeo;
 988         int rc = 0;
 989
 990         lsmc = smc_sk(sk);
 991         lock_sock(sk);
 992
 993         if (lsmc->sk.sk_state != SMC_LISTEN) {
 994                 rc = -EINVAL;
 995                 goto out;
 996         }
 997
 998         /* Wait for an incoming connection */
 999         timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1000         add_wait_queue_exclusive(sk_sleep(sk), &wait);
1001         while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1002                 set_current_state(TASK_INTERRUPTIBLE);
1003                 if (!timeo) {
1004                         rc = -EAGAIN;
1005                         break;
1006                 }
1007                 release_sock(sk);
1008                 timeo = schedule_timeout(timeo);
1009                 /* wakeup by sk_data_ready in smc_listen_work() */
1010                 sched_annotate_sleep();
1011                 lock_sock(sk);
1012                 if (signal_pending(current)) {
1013                         rc = sock_intr_errno(timeo);
1014                         break;
1015                 }
1016         }
1017         set_current_state(TASK_RUNNING);
1018         remove_wait_queue(sk_sleep(sk), &wait);
1019
1020         if (!rc)
1021                 rc = sock_error(nsk);
1022
1023 out:
1024         release_sock(sk);
1025         return rc;
1026 }
1027
1028 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1029                        int *len, int peer)
1030 {
1031         struct smc_sock *smc;
1032
1033         if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
1034             (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
1035                 return -ENOTCONN;
1036
1037         smc = smc_sk(sock->sk);
1038
1039         return smc->clcsock->ops->getname(smc->clcsock, addr, len, peer);
1040 }
1041
1042 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1043 {
1044         struct sock *sk = sock->sk;
1045         struct smc_sock *smc;
1046         int rc = -EPIPE;
1047
1048         smc = smc_sk(sk);
1049         lock_sock(sk);
1050         if ((sk->sk_state != SMC_ACTIVE) &&
1051             (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1052             (sk->sk_state != SMC_INIT))
1053                 goto out;
1054         if (smc->use_fallback)
1055                 rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
1056         else
1057                 rc = smc_tx_sendmsg(smc, msg, len);
1058 out:
1059         release_sock(sk);
1060         return rc;
1061 }
1062
1063 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1064                        int flags)
1065 {
1066         struct sock *sk = sock->sk;
1067         struct smc_sock *smc;
1068         int rc = -ENOTCONN;
1069
1070         smc = smc_sk(sk);
1071         lock_sock(sk);
1072         if ((sk->sk_state == SMC_INIT) ||
1073             (sk->sk_state == SMC_LISTEN) ||
1074             (sk->sk_state == SMC_CLOSED))
1075                 goto out;
1076
1077         if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1078                 rc = 0;
1079                 goto out;
1080         }
1081
1082         if (smc->use_fallback)
1083                 rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
1084         else
1085                 rc = smc_rx_recvmsg(smc, msg, len, flags);
1086
1087 out:
1088         release_sock(sk);
1089         return rc;
1090 }
1091
1092 static unsigned int smc_accept_poll(struct sock *parent)
1093 {
1094         struct smc_sock *isk;
1095         struct sock *sk;
1096
1097         lock_sock(parent);
1098         list_for_each_entry(isk, &smc_sk(parent)->accept_q, accept_q) {
1099                 sk = (struct sock *)isk;
1100
1101                 if (sk->sk_state == SMC_ACTIVE) {
1102                         release_sock(parent);
1103                         return POLLIN | POLLRDNORM;
1104                 }
1105         }
1106         release_sock(parent);
1107
1108         return 0;
1109 }
1110
1111 static unsigned int smc_poll(struct file *file, struct socket *sock,
1112                              poll_table *wait)
1113 {
1114         struct sock *sk = sock->sk;
1115         unsigned int mask = 0;
1116         struct smc_sock *smc;
1117         int rc;
1118
1119         smc = smc_sk(sock->sk);
1120         if ((sk->sk_state == SMC_INIT) || smc->use_fallback) {
1121                 /* delegate to CLC child sock */
1122                 mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
1123                 /* if non-blocking connect finished ... */
1124                 lock_sock(sk);
1125                 if ((sk->sk_state == SMC_INIT) && (mask & POLLOUT)) {
1126                         sk->sk_err = smc->clcsock->sk->sk_err;
1127                         if (sk->sk_err) {
1128                                 mask |= POLLERR;
1129                         } else {
1130                                 rc = smc_connect_rdma(smc);
1131                                 if (rc < 0)
1132                                         mask |= POLLERR;
1133                                 else
1134                                         /* success cases including fallback */
1135                                         mask |= POLLOUT | POLLWRNORM;
1136                         }
1137                 }
1138                 release_sock(sk);
1139         } else {
1140                 sock_poll_wait(file, sk_sleep(sk), wait);
1141                 if (sk->sk_state == SMC_LISTEN)
1142                         /* woken up by sk_data_ready in smc_listen_work() */
1143                         mask |= smc_accept_poll(sk);
1144                 if (sk->sk_err)
1145                         mask |= POLLERR;
1146                 if (atomic_read(&smc->conn.sndbuf_space) ||
1147                     (sk->sk_shutdown & SEND_SHUTDOWN)) {
1148                         mask |= POLLOUT | POLLWRNORM;
1149                 } else {
1150                         sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1151                         set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1152                 }
1153                 if (atomic_read(&smc->conn.bytes_to_rcv))
1154                         mask |= POLLIN | POLLRDNORM;
1155                 if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1156                     (sk->sk_state == SMC_CLOSED))
1157                         mask |= POLLHUP;
1158                 if (sk->sk_shutdown & RCV_SHUTDOWN)
1159                         mask |= POLLIN | POLLRDNORM | POLLRDHUP;
1160                 if (sk->sk_state == SMC_APPCLOSEWAIT1)
1161                         mask |= POLLIN;
1162
1163         }
1164
1165         return mask;
1166 }
1167
1168 static int smc_shutdown(struct socket *sock, int how)
1169 {
1170         struct sock *sk = sock->sk;
1171         struct smc_sock *smc;
1172         int rc = -EINVAL;
1173         int rc1 = 0;
1174
1175         smc = smc_sk(sk);
1176
1177         if ((how < SHUT_RD) || (how > SHUT_RDWR))
1178                 return rc;
1179
1180         lock_sock(sk);
1181
1182         rc = -ENOTCONN;
1183         if ((sk->sk_state != SMC_LISTEN) &&
1184             (sk->sk_state != SMC_ACTIVE) &&
1185             (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
1186             (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
1187             (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1188             (sk->sk_state != SMC_APPCLOSEWAIT2) &&
1189             (sk->sk_state != SMC_APPFINCLOSEWAIT))
1190                 goto out;
1191         if (smc->use_fallback) {
1192                 rc = kernel_sock_shutdown(smc->clcsock, how);
1193                 sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
1194                 if (sk->sk_shutdown == SHUTDOWN_MASK)
1195                         sk->sk_state = SMC_CLOSED;
1196                 goto out;
1197         }
1198         switch (how) {
1199         case SHUT_RDWR:         /* shutdown in both directions */
1200                 rc = smc_close_active(smc);
1201                 break;
1202         case SHUT_WR:
1203                 rc = smc_close_shutdown_write(smc);
1204                 break;
1205         case SHUT_RD:
1206                 if (sk->sk_state == SMC_LISTEN)
1207                         rc = smc_close_active(smc);
1208                 else
1209                         rc = 0;
1210                         /* nothing more to do because peer is not involved */
1211                 break;
1212         }
1213         rc1 = kernel_sock_shutdown(smc->clcsock, how);
1214         /* map sock_shutdown_cmd constants to sk_shutdown value range */
1215         sk->sk_shutdown |= how + 1;
1216
1217 out:
1218         release_sock(sk);
1219         return rc ? rc : rc1;
1220 }
1221
1222 static int smc_setsockopt(struct socket *sock, int level, int optname,
1223                           char __user *optval, unsigned int optlen)
1224 {
1225         struct sock *sk = sock->sk;
1226         struct smc_sock *smc;
1227
1228         smc = smc_sk(sk);
1229
1230         /* generic setsockopts reaching us here always apply to the
1231          * CLC socket
1232          */
1233         return smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
1234                                              optval, optlen);
1235 }
1236
1237 static int smc_getsockopt(struct socket *sock, int level, int optname,
1238                           char __user *optval, int __user *optlen)
1239 {
1240         struct smc_sock *smc;
1241
1242         smc = smc_sk(sock->sk);
1243         /* socket options apply to the CLC socket */
1244         return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
1245                                              optval, optlen);
1246 }
1247
1248 static int smc_ioctl(struct socket *sock, unsigned int cmd,
1249                      unsigned long arg)
1250 {
1251         struct smc_sock *smc;
1252
1253         smc = smc_sk(sock->sk);
1254         if (smc->use_fallback)
1255                 return smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
1256         else
1257                 return sock_no_ioctl(sock, cmd, arg);
1258 }
1259
1260 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
1261                             int offset, size_t size, int flags)
1262 {
1263         struct sock *sk = sock->sk;
1264         struct smc_sock *smc;
1265         int rc = -EPIPE;
1266
1267         smc = smc_sk(sk);
1268         lock_sock(sk);
1269         if (sk->sk_state != SMC_ACTIVE)
1270                 goto out;
1271         if (smc->use_fallback)
1272                 rc = kernel_sendpage(smc->clcsock, page, offset,
1273                                      size, flags);
1274         else
1275                 rc = sock_no_sendpage(sock, page, offset, size, flags);
1276
1277 out:
1278         release_sock(sk);
1279         return rc;
1280 }
1281
1282 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
1283                                struct pipe_inode_info *pipe, size_t len,
1284                                     unsigned int flags)
1285 {
1286         struct sock *sk = sock->sk;
1287         struct smc_sock *smc;
1288         int rc = -ENOTCONN;
1289
1290         smc = smc_sk(sk);
1291         lock_sock(sk);
1292         if ((sk->sk_state != SMC_ACTIVE) && (sk->sk_state != SMC_CLOSED))
1293                 goto out;
1294         if (smc->use_fallback) {
1295                 rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
1296                                                     pipe, len, flags);
1297         } else {
1298                 rc = -EOPNOTSUPP;
1299         }
1300 out:
1301         release_sock(sk);
1302         return rc;
1303 }
1304
1305 /* must look like tcp */
1306 static const struct proto_ops smc_sock_ops = {
1307         .family         = PF_SMC,
1308         .owner          = THIS_MODULE,
1309         .release        = smc_release,
1310         .bind           = smc_bind,
1311         .connect        = smc_connect,
1312         .socketpair     = sock_no_socketpair,
1313         .accept         = smc_accept,
1314         .getname        = smc_getname,
1315         .poll           = smc_poll,
1316         .ioctl          = smc_ioctl,
1317         .listen         = smc_listen,
1318         .shutdown       = smc_shutdown,
1319         .setsockopt     = smc_setsockopt,
1320         .getsockopt     = smc_getsockopt,
1321         .sendmsg        = smc_sendmsg,
1322         .recvmsg        = smc_recvmsg,
1323         .mmap           = sock_no_mmap,
1324         .sendpage       = smc_sendpage,
1325         .splice_read    = smc_splice_read,
1326 };
1327
1328 static int smc_create(struct net *net, struct socket *sock, int protocol,
1329                       int kern)
1330 {
1331         struct smc_sock *smc;
1332         struct sock *sk;
1333         int rc;
1334
1335         rc = -ESOCKTNOSUPPORT;
1336         if (sock->type != SOCK_STREAM)
1337                 goto out;
1338
1339         rc = -EPROTONOSUPPORT;
1340         if ((protocol != IPPROTO_IP) && (protocol != IPPROTO_TCP))
1341                 goto out;
1342
1343         rc = -ENOBUFS;
1344         sock->ops = &smc_sock_ops;
1345         sk = smc_sock_alloc(net, sock);
1346         if (!sk)
1347                 goto out;
1348
1349         /* create internal TCP socket for CLC handshake and fallback */
1350         smc = smc_sk(sk);
1351         smc->use_fallback = false; /* assume rdma capability first */
1352         rc = sock_create_kern(net, PF_INET, SOCK_STREAM,
1353                               IPPROTO_TCP, &smc->clcsock);
1354         if (rc)
1355                 sk_common_release(sk);
1356         smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
1357         smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
1358
1359 out:
1360         return rc;
1361 }
1362
1363 static const struct net_proto_family smc_sock_family_ops = {
1364         .family = PF_SMC,
1365         .owner  = THIS_MODULE,
1366         .create = smc_create,
1367 };
1368
1369 static int __init smc_init(void)
1370 {
1371         int rc;
1372
1373         rc = smc_pnet_init();
1374         if (rc)
1375                 return rc;
1376
1377         rc = smc_llc_init();
1378         if (rc) {
1379                 pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
1380                 goto out_pnet;
1381         }
1382
1383         rc = smc_cdc_init();
1384         if (rc) {
1385                 pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
1386                 goto out_pnet;
1387         }
1388
1389         rc = proto_register(&smc_proto, 1);
1390         if (rc) {
1391                 pr_err("%s: proto_register fails with %d\n", __func__, rc);
1392                 goto out_pnet;
1393         }
1394
1395         rc = sock_register(&smc_sock_family_ops);
1396         if (rc) {
1397                 pr_err("%s: sock_register fails with %d\n", __func__, rc);
1398                 goto out_proto;
1399         }
1400         INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
1401
1402         rc = smc_ib_register_client();
1403         if (rc) {
1404                 pr_err("%s: ib_register fails with %d\n", __func__, rc);
1405                 goto out_sock;
1406         }
1407
1408         return 0;
1409
1410 out_sock:
1411         sock_unregister(PF_SMC);
1412 out_proto:
1413         proto_unregister(&smc_proto);
1414 out_pnet:
1415         smc_pnet_exit();
1416         return rc;
1417 }
1418
1419 static void __exit smc_exit(void)
1420 {
1421         struct smc_link_group *lgr, *lg;
1422         LIST_HEAD(lgr_freeing_list);
1423
1424         spin_lock_bh(&smc_lgr_list.lock);
1425         if (!list_empty(&smc_lgr_list.list))
1426                 list_splice_init(&smc_lgr_list.list, &lgr_freeing_list);
1427         spin_unlock_bh(&smc_lgr_list.lock);
1428         list_for_each_entry_safe(lgr, lg, &lgr_freeing_list, list) {
1429                 list_del_init(&lgr->list);
1430                 smc_lgr_free(lgr); /* free link group */
1431         }
1432         smc_ib_unregister_client();
1433         sock_unregister(PF_SMC);
1434         proto_unregister(&smc_proto);
1435         smc_pnet_exit();
1436 }
1437
1438 module_init(smc_init);
1439 module_exit(smc_exit);
1440
1441 MODULE_AUTHOR("Ursula Braun <[email protected]>");
1442 MODULE_DESCRIPTION("smc socket address family");
1443 MODULE_LICENSE("GPL");
1444 MODULE_ALIAS_NETPROTO(PF_SMC);