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