net/smc/af_smc.c

   1 /*
   2  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
   3  *
   4  *  AF_SMC protocol family socket handler keeping the AF_INET sock address type
   5  *  applies to SOCK_STREAM sockets only
   6  *  offers an alternative communication option for TCP-protocol sockets
   7  *  applicable with RoCE-cards only
   8  *
   9  *  Initial restrictions:
  10  *    - support for alternate links postponed
  11  *
  12  *  Copyright IBM Corp. 2016, 2018
  13  *
  14  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
  15  *              based on prototype from Frank Blaschka
  16  */
  17
  18 #define KMSG_COMPONENT "smc"
  19 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  20
  21 #include <linux/module.h>
  22 #include <linux/socket.h>
  23 #include <linux/workqueue.h>
  24 #include <linux/in.h>
  25 #include <linux/sched/signal.h>
  26
  27 #include <net/sock.h>
  28 #include <net/tcp.h>
  29 #include <net/smc.h>
  30 #include <asm/ioctls.h>
  31
  32 #include "smc.h"
  33 #include "smc_clc.h"
  34 #include "smc_llc.h"
  35 #include "smc_cdc.h"
  36 #include "smc_core.h"
  37 #include "smc_ib.h"
  38 #include "smc_pnet.h"
  39 #include "smc_tx.h"
  40 #include "smc_rx.h"
  41 #include "smc_close.h"
  42
  43 static DEFINE_MUTEX(smc_create_lgr_pending);    /* serialize link group
  44                                                  * creation
  45                                                  */
  46
  47 static void smc_tcp_listen_work(struct work_struct *);
  48 static void smc_connect_work(struct work_struct *);
  49
  50 static void smc_set_keepalive(struct sock *sk, int val)
  51 {
  52         struct smc_sock *smc = smc_sk(sk);
  53
  54         smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
  55 }
  56
  57 static struct smc_hashinfo smc_v4_hashinfo = {
  58         .lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
  59 };
  60
  61 static struct smc_hashinfo smc_v6_hashinfo = {
  62         .lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
  63 };
  64
  65 int smc_hash_sk(struct sock *sk)
  66 {
  67         struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
  68         struct hlist_head *head;
  69
  70         head = &h->ht;
  71
  72         write_lock_bh(&h->lock);
  73         sk_add_node(sk, head);
  74         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
  75         write_unlock_bh(&h->lock);
  76
  77         return 0;
  78 }
  79 EXPORT_SYMBOL_GPL(smc_hash_sk);
  80
  81 void smc_unhash_sk(struct sock *sk)
  82 {
  83         struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
  84
  85         write_lock_bh(&h->lock);
  86         if (sk_del_node_init(sk))
  87                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
  88         write_unlock_bh(&h->lock);
  89 }
  90 EXPORT_SYMBOL_GPL(smc_unhash_sk);
  91
  92 struct proto smc_proto = {
  93         .name           = "SMC",
  94         .owner          = THIS_MODULE,
  95         .keepalive      = smc_set_keepalive,
  96         .hash           = smc_hash_sk,
  97         .unhash         = smc_unhash_sk,
  98         .obj_size       = sizeof(struct smc_sock),
  99         .h.smc_hash     = &smc_v4_hashinfo,
 100         .slab_flags     = SLAB_TYPESAFE_BY_RCU,
 101 };
 102 EXPORT_SYMBOL_GPL(smc_proto);
 103
 104 struct proto smc_proto6 = {
 105         .name           = "SMC6",
 106         .owner          = THIS_MODULE,
 107         .keepalive      = smc_set_keepalive,
 108         .hash           = smc_hash_sk,
 109         .unhash         = smc_unhash_sk,
 110         .obj_size       = sizeof(struct smc_sock),
 111         .h.smc_hash     = &smc_v6_hashinfo,
 112         .slab_flags     = SLAB_TYPESAFE_BY_RCU,
 113 };
 114 EXPORT_SYMBOL_GPL(smc_proto6);
 115
 116 static int smc_release(struct socket *sock)
 117 {
 118         struct sock *sk = sock->sk;
 119         struct smc_sock *smc;
 120         int rc = 0;
 121
 122         if (!sk)
 123                 goto out;
 124
 125         smc = smc_sk(sk);
 126
 127         /* cleanup for a dangling non-blocking connect */
 128         flush_work(&smc->connect_work);
 129         kfree(smc->connect_info);
 130         smc->connect_info = NULL;
 131
 132         if (sk->sk_state == SMC_LISTEN)
 133                 /* smc_close_non_accepted() is called and acquires
 134                  * sock lock for child sockets again
 135                  */
 136                 lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 137         else
 138                 lock_sock(sk);
 139
 140         if (!smc->use_fallback) {
 141                 rc = smc_close_active(smc);
 142                 sock_set_flag(sk, SOCK_DEAD);
 143                 sk->sk_shutdown |= SHUTDOWN_MASK;
 144         }
 145         if (smc->clcsock) {
 146                 sock_release(smc->clcsock);
 147                 smc->clcsock = NULL;
 148         }
 149         if (smc->use_fallback) {
 150                 sock_put(sk); /* passive closing */
 151                 sk->sk_state = SMC_CLOSED;
 152                 sk->sk_state_change(sk);
 153         }
 154
 155         /* detach socket */
 156         sock_orphan(sk);
 157         sock->sk = NULL;
 158         if (!smc->use_fallback && sk->sk_state == SMC_CLOSED)
 159                 smc_conn_free(&smc->conn);
 160         release_sock(sk);
 161
 162         sk->sk_prot->unhash(sk);
 163         sock_put(sk); /* final sock_put */
 164 out:
 165         return rc;
 166 }
 167
 168 static void smc_destruct(struct sock *sk)
 169 {
 170         if (sk->sk_state != SMC_CLOSED)
 171                 return;
 172         if (!sock_flag(sk, SOCK_DEAD))
 173                 return;
 174
 175         sk_refcnt_debug_dec(sk);
 176 }
 177
 178 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
 179                                    int protocol)
 180 {
 181         struct smc_sock *smc;
 182         struct proto *prot;
 183         struct sock *sk;
 184
 185         prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
 186         sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
 187         if (!sk)
 188                 return NULL;
 189
 190         sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
 191         sk->sk_state = SMC_INIT;
 192         sk->sk_destruct = smc_destruct;
 193         sk->sk_protocol = protocol;
 194         smc = smc_sk(sk);
 195         INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
 196         INIT_WORK(&smc->connect_work, smc_connect_work);
 197         INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
 198         INIT_LIST_HEAD(&smc->accept_q);
 199         spin_lock_init(&smc->accept_q_lock);
 200         spin_lock_init(&smc->conn.send_lock);
 201         sk->sk_prot->hash(sk);
 202         sk_refcnt_debug_inc(sk);
 203
 204         return sk;
 205 }
 206
 207 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
 208                     int addr_len)
 209 {
 210         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
 211         struct sock *sk = sock->sk;
 212         struct smc_sock *smc;
 213         int rc;
 214
 215         smc = smc_sk(sk);
 216
 217         /* replicate tests from inet_bind(), to be safe wrt. future changes */
 218         rc = -EINVAL;
 219         if (addr_len < sizeof(struct sockaddr_in))
 220                 goto out;
 221
 222         rc = -EAFNOSUPPORT;
 223         if (addr->sin_family != AF_INET &&
 224             addr->sin_family != AF_INET6 &&
 225             addr->sin_family != AF_UNSPEC)
 226                 goto out;
 227         /* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
 228         if (addr->sin_family == AF_UNSPEC &&
 229             addr->sin_addr.s_addr != htonl(INADDR_ANY))
 230                 goto out;
 231
 232         lock_sock(sk);
 233
 234         /* Check if socket is already active */
 235         rc = -EINVAL;
 236         if (sk->sk_state != SMC_INIT)
 237                 goto out_rel;
 238
 239         smc->clcsock->sk->sk_reuse = sk->sk_reuse;
 240         rc = kernel_bind(smc->clcsock, uaddr, addr_len);
 241
 242 out_rel:
 243         release_sock(sk);
 244 out:
 245         return rc;
 246 }
 247
 248 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
 249                                    unsigned long mask)
 250 {
 251         /* options we don't get control via setsockopt for */
 252         nsk->sk_type = osk->sk_type;
 253         nsk->sk_sndbuf = osk->sk_sndbuf;
 254         nsk->sk_rcvbuf = osk->sk_rcvbuf;
 255         nsk->sk_sndtimeo = osk->sk_sndtimeo;
 256         nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
 257         nsk->sk_mark = osk->sk_mark;
 258         nsk->sk_priority = osk->sk_priority;
 259         nsk->sk_rcvlowat = osk->sk_rcvlowat;
 260         nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
 261         nsk->sk_err = osk->sk_err;
 262
 263         nsk->sk_flags &= ~mask;
 264         nsk->sk_flags |= osk->sk_flags & mask;
 265 }
 266
 267 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
 268                              (1UL << SOCK_KEEPOPEN) | \
 269                              (1UL << SOCK_LINGER) | \
 270                              (1UL << SOCK_BROADCAST) | \
 271                              (1UL << SOCK_TIMESTAMP) | \
 272                              (1UL << SOCK_DBG) | \
 273                              (1UL << SOCK_RCVTSTAMP) | \
 274                              (1UL << SOCK_RCVTSTAMPNS) | \
 275                              (1UL << SOCK_LOCALROUTE) | \
 276                              (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
 277                              (1UL << SOCK_RXQ_OVFL) | \
 278                              (1UL << SOCK_WIFI_STATUS) | \
 279                              (1UL << SOCK_NOFCS) | \
 280                              (1UL << SOCK_FILTER_LOCKED))
 281 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
 282  * clc socket (since smc is not called for these options from net/core)
 283  */
 284 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
 285 {
 286         smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
 287 }
 288
 289 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
 290                              (1UL << SOCK_KEEPOPEN) | \
 291                              (1UL << SOCK_LINGER) | \
 292                              (1UL << SOCK_DBG))
 293 /* copy only settings and flags relevant for smc from clc to smc socket */
 294 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
 295 {
 296         smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
 297 }
 298
 299 /* register a new rmb, optionally send confirm_rkey msg to register with peer */
 300 static int smc_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc,
 301                        bool conf_rkey)
 302 {
 303         /* register memory region for new rmb */
 304         if (smc_wr_reg_send(link, rmb_desc->mr_rx[SMC_SINGLE_LINK])) {
 305                 rmb_desc->regerr = 1;
 306                 return -EFAULT;
 307         }
 308         if (!conf_rkey)
 309                 return 0;
 310         /* exchange confirm_rkey msg with peer */
 311         if (smc_llc_do_confirm_rkey(link, rmb_desc)) {
 312                 rmb_desc->regerr = 1;
 313                 return -EFAULT;
 314         }
 315         return 0;
 316 }
 317
 318 static int smc_clnt_conf_first_link(struct smc_sock *smc)
 319 {
 320         struct net *net = sock_net(smc->clcsock->sk);
 321         struct smc_link_group *lgr = smc->conn.lgr;
 322         struct smc_link *link;
 323         int rest;
 324         int rc;
 325
 326         link = &lgr->lnk[SMC_SINGLE_LINK];
 327         /* receive CONFIRM LINK request from server over RoCE fabric */
 328         rest = wait_for_completion_interruptible_timeout(
 329                 &link->llc_confirm,
 330                 SMC_LLC_WAIT_FIRST_TIME);
 331         if (rest <= 0) {
 332                 struct smc_clc_msg_decline dclc;
 333
 334                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
 335                                       SMC_CLC_DECLINE);
 336                 return rc;
 337         }
 338
 339         if (link->llc_confirm_rc)
 340                 return SMC_CLC_DECL_RMBE_EC;
 341
 342         rc = smc_ib_modify_qp_rts(link);
 343         if (rc)
 344                 return SMC_CLC_DECL_INTERR;
 345
 346         smc_wr_remember_qp_attr(link);
 347
 348         if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
 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                                        &link->smcibdev->gid[link->ibport - 1],
 355                                        SMC_LLC_RESP);
 356         if (rc < 0)
 357                 return SMC_CLC_DECL_TCL;
 358
 359         /* receive ADD LINK request from server over RoCE fabric */
 360         rest = wait_for_completion_interruptible_timeout(&link->llc_add,
 361                                                          SMC_LLC_WAIT_TIME);
 362         if (rest <= 0) {
 363                 struct smc_clc_msg_decline dclc;
 364
 365                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
 366                                       SMC_CLC_DECLINE);
 367                 return rc;
 368         }
 369
 370         /* send add link reject message, only one link supported for now */
 371         rc = smc_llc_send_add_link(link,
 372                                    link->smcibdev->mac[link->ibport - 1],
 373                                    &link->smcibdev->gid[link->ibport - 1],
 374                                    SMC_LLC_RESP);
 375         if (rc < 0)
 376                 return SMC_CLC_DECL_TCL;
 377
 378         smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
 379
 380         return 0;
 381 }
 382
 383 static void smc_conn_save_peer_info(struct smc_sock *smc,
 384                                     struct smc_clc_msg_accept_confirm *clc)
 385 {
 386         int bufsize = smc_uncompress_bufsize(clc->rmbe_size);
 387
 388         smc->conn.peer_rmbe_idx = clc->rmbe_idx;
 389         smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
 390         smc->conn.peer_rmbe_size = bufsize;
 391         atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
 392         smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
 393 }
 394
 395 static void smc_link_save_peer_info(struct smc_link *link,
 396                                     struct smc_clc_msg_accept_confirm *clc)
 397 {
 398         link->peer_qpn = ntoh24(clc->qpn);
 399         memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
 400         memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
 401         link->peer_psn = ntoh24(clc->psn);
 402         link->peer_mtu = clc->qp_mtu;
 403 }
 404
 405 /* fall back during connect */
 406 static int smc_connect_fallback(struct smc_sock *smc)
 407 {
 408         smc->use_fallback = true;
 409         smc_copy_sock_settings_to_clc(smc);
 410         if (smc->sk.sk_state == SMC_INIT)
 411                 smc->sk.sk_state = SMC_ACTIVE;
 412         return 0;
 413 }
 414
 415 /* decline and fall back during connect */
 416 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code)
 417 {
 418         int rc;
 419
 420         if (reason_code < 0) /* error, fallback is not possible */
 421                 return reason_code;
 422         if (reason_code != SMC_CLC_DECL_REPLY) {
 423                 rc = smc_clc_send_decline(smc, reason_code);
 424                 if (rc < 0)
 425                         return rc;
 426         }
 427         return smc_connect_fallback(smc);
 428 }
 429
 430 /* abort connecting */
 431 static int smc_connect_abort(struct smc_sock *smc, int reason_code,
 432                              int local_contact)
 433 {
 434         if (local_contact == SMC_FIRST_CONTACT)
 435                 smc_lgr_forget(smc->conn.lgr);
 436         mutex_unlock(&smc_create_lgr_pending);
 437         smc_conn_free(&smc->conn);
 438         if (reason_code < 0 && smc->sk.sk_state == SMC_INIT)
 439                 sock_put(&smc->sk); /* passive closing */
 440         return reason_code;
 441 }
 442
 443 /* check if there is a rdma device available for this connection. */
 444 /* called for connect and listen */
 445 static int smc_check_rdma(struct smc_sock *smc, struct smc_ib_device **ibdev,
 446                           u8 *ibport)
 447 {
 448         int reason_code = 0;
 449
 450         /* PNET table look up: search active ib_device and port
 451          * within same PNETID that also contains the ethernet device
 452          * used for the internal TCP socket
 453          */
 454         smc_pnet_find_roce_resource(smc->clcsock->sk, ibdev, ibport);
 455         if (!(*ibdev))
 456                 reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
 457
 458         return reason_code;
 459 }
 460
 461 /* CLC handshake during connect */
 462 static int smc_connect_clc(struct smc_sock *smc,
 463                            struct smc_clc_msg_accept_confirm *aclc,
 464                            struct smc_ib_device *ibdev, u8 ibport)
 465 {
 466         int rc = 0;
 467
 468         /* do inband token exchange */
 469         rc = smc_clc_send_proposal(smc, ibdev, ibport);
 470         if (rc)
 471                 return rc;
 472         /* receive SMC Accept CLC message */
 473         return smc_clc_wait_msg(smc, aclc, sizeof(*aclc), SMC_CLC_ACCEPT);
 474 }
 475
 476 /* setup for RDMA connection of client */
 477 static int smc_connect_rdma(struct smc_sock *smc,
 478                             struct smc_clc_msg_accept_confirm *aclc,
 479                             struct smc_ib_device *ibdev, u8 ibport)
 480 {
 481         int local_contact = SMC_FIRST_CONTACT;
 482         struct smc_link *link;
 483         int reason_code = 0;
 484
 485         mutex_lock(&smc_create_lgr_pending);
 486         local_contact = smc_conn_create(smc, ibdev, ibport, &aclc->lcl,
 487                                         aclc->hdr.flag);
 488         if (local_contact < 0) {
 489                 if (local_contact == -ENOMEM)
 490                         reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
 491                 else if (local_contact == -ENOLINK)
 492                         reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
 493                 else
 494                         reason_code = SMC_CLC_DECL_INTERR; /* other error */
 495                 return smc_connect_abort(smc, reason_code, 0);
 496         }
 497         link = &smc->conn.lgr->lnk[SMC_SINGLE_LINK];
 498
 499         smc_conn_save_peer_info(smc, aclc);
 500
 501         /* create send buffer and rmb */
 502         if (smc_buf_create(smc))
 503                 return smc_connect_abort(smc, SMC_CLC_DECL_MEM, local_contact);
 504
 505         if (local_contact == SMC_FIRST_CONTACT)
 506                 smc_link_save_peer_info(link, aclc);
 507
 508         if (smc_rmb_rtoken_handling(&smc->conn, aclc))
 509                 return smc_connect_abort(smc, SMC_CLC_DECL_INTERR,
 510                                          local_contact);
 511
 512         smc_close_init(smc);
 513         smc_rx_init(smc);
 514
 515         if (local_contact == SMC_FIRST_CONTACT) {
 516                 if (smc_ib_ready_link(link))
 517                         return smc_connect_abort(smc, SMC_CLC_DECL_INTERR,
 518                                                  local_contact);
 519         } else {
 520                 if (!smc->conn.rmb_desc->reused &&
 521                     smc_reg_rmb(link, smc->conn.rmb_desc, true))
 522                         return smc_connect_abort(smc, SMC_CLC_DECL_INTERR,
 523                                                  local_contact);
 524         }
 525         smc_rmb_sync_sg_for_device(&smc->conn);
 526
 527         reason_code = smc_clc_send_confirm(smc);
 528         if (reason_code)
 529                 return smc_connect_abort(smc, reason_code, local_contact);
 530
 531         smc_tx_init(smc);
 532
 533         if (local_contact == SMC_FIRST_CONTACT) {
 534                 /* QP confirmation over RoCE fabric */
 535                 reason_code = smc_clnt_conf_first_link(smc);
 536                 if (reason_code)
 537                         return smc_connect_abort(smc, reason_code,
 538                                                  local_contact);
 539         }
 540         mutex_unlock(&smc_create_lgr_pending);
 541
 542         smc_copy_sock_settings_to_clc(smc);
 543         if (smc->sk.sk_state == SMC_INIT)
 544                 smc->sk.sk_state = SMC_ACTIVE;
 545
 546         return 0;
 547 }
 548
 549 /* perform steps before actually connecting */
 550 static int __smc_connect(struct smc_sock *smc)
 551 {
 552         struct smc_clc_msg_accept_confirm aclc;
 553         struct smc_ib_device *ibdev;
 554         int rc = 0;
 555         u8 ibport;
 556
 557         sock_hold(&smc->sk); /* sock put in passive closing */
 558
 559         if (smc->use_fallback)
 560                 return smc_connect_fallback(smc);
 561
 562         /* if peer has not signalled SMC-capability, fall back */
 563         if (!tcp_sk(smc->clcsock->sk)->syn_smc)
 564                 return smc_connect_fallback(smc);
 565
 566         /* IPSec connections opt out of SMC-R optimizations */
 567         if (using_ipsec(smc))
 568                 return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC);
 569
 570         /* check if a RDMA device is available; if not, fall back */
 571         if (smc_check_rdma(smc, &ibdev, &ibport))
 572                 return smc_connect_decline_fallback(smc, SMC_CLC_DECL_CNFERR);
 573
 574         /* perform CLC handshake */
 575         rc = smc_connect_clc(smc, &aclc, ibdev, ibport);
 576         if (rc)
 577                 return smc_connect_decline_fallback(smc, rc);
 578
 579         /* connect using rdma */
 580         rc = smc_connect_rdma(smc, &aclc, ibdev, ibport);
 581         if (rc)
 582                 return smc_connect_decline_fallback(smc, rc);
 583
 584         return 0;
 585 }
 586
 587 static void smc_connect_work(struct work_struct *work)
 588 {
 589         struct smc_sock *smc = container_of(work, struct smc_sock,
 590                                             connect_work);
 591         int rc;
 592
 593         lock_sock(&smc->sk);
 594         rc = kernel_connect(smc->clcsock, &smc->connect_info->addr,
 595                             smc->connect_info->alen, smc->connect_info->flags);
 596         if (smc->clcsock->sk->sk_err) {
 597                 smc->sk.sk_err = smc->clcsock->sk->sk_err;
 598                 goto out;
 599         }
 600         if (rc < 0) {
 601                 smc->sk.sk_err = -rc;
 602                 goto out;
 603         }
 604
 605         rc = __smc_connect(smc);
 606         if (rc < 0)
 607                 smc->sk.sk_err = -rc;
 608
 609 out:
 610         smc->sk.sk_state_change(&smc->sk);
 611         kfree(smc->connect_info);
 612         smc->connect_info = NULL;
 613         release_sock(&smc->sk);
 614 }
 615
 616 static int smc_connect(struct socket *sock, struct sockaddr *addr,
 617                        int alen, int flags)
 618 {
 619         struct sock *sk = sock->sk;
 620         struct smc_sock *smc;
 621         int rc = -EINVAL;
 622
 623         smc = smc_sk(sk);
 624
 625         /* separate smc parameter checking to be safe */
 626         if (alen < sizeof(addr->sa_family))
 627                 goto out_err;
 628         if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
 629                 goto out_err;
 630
 631         lock_sock(sk);
 632         switch (sk->sk_state) {
 633         default:
 634                 goto out;
 635         case SMC_ACTIVE:
 636                 rc = -EISCONN;
 637                 goto out;
 638         case SMC_INIT:
 639                 rc = 0;
 640                 break;
 641         }
 642
 643         smc_copy_sock_settings_to_clc(smc);
 644         tcp_sk(smc->clcsock->sk)->syn_smc = 1;
 645         if (flags & O_NONBLOCK) {
 646                 if (smc->connect_info) {
 647                         rc = -EALREADY;
 648                         goto out;
 649                 }
 650                 smc->connect_info = kzalloc(alen + 2 * sizeof(int), GFP_KERNEL);
 651                 if (!smc->connect_info) {
 652                         rc = -ENOMEM;
 653                         goto out;
 654                 }
 655                 smc->connect_info->alen = alen;
 656                 smc->connect_info->flags = flags ^ O_NONBLOCK;
 657                 memcpy(&smc->connect_info->addr, addr, alen);
 658                 schedule_work(&smc->connect_work);
 659                 rc = -EINPROGRESS;
 660         } else {
 661                 rc = kernel_connect(smc->clcsock, addr, alen, flags);
 662                 if (rc)
 663                         goto out;
 664
 665                 rc = __smc_connect(smc);
 666                 if (rc < 0)
 667                         goto out;
 668                 else
 669                         rc = 0; /* success cases including fallback */
 670         }
 671
 672 out:
 673         release_sock(sk);
 674 out_err:
 675         return rc;
 676 }
 677
 678 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
 679 {
 680         struct socket *new_clcsock = NULL;
 681         struct sock *lsk = &lsmc->sk;
 682         struct sock *new_sk;
 683         int rc;
 684
 685         release_sock(lsk);
 686         new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
 687         if (!new_sk) {
 688                 rc = -ENOMEM;
 689                 lsk->sk_err = ENOMEM;
 690                 *new_smc = NULL;
 691                 lock_sock(lsk);
 692                 goto out;
 693         }
 694         *new_smc = smc_sk(new_sk);
 695
 696         rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
 697         lock_sock(lsk);
 698         if  (rc < 0)
 699                 lsk->sk_err = -rc;
 700         if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
 701                 if (new_clcsock)
 702                         sock_release(new_clcsock);
 703                 new_sk->sk_state = SMC_CLOSED;
 704                 sock_set_flag(new_sk, SOCK_DEAD);
 705                 new_sk->sk_prot->unhash(new_sk);
 706                 sock_put(new_sk); /* final */
 707                 *new_smc = NULL;
 708                 goto out;
 709         }
 710
 711         (*new_smc)->clcsock = new_clcsock;
 712 out:
 713         return rc;
 714 }
 715
 716 /* add a just created sock to the accept queue of the listen sock as
 717  * candidate for a following socket accept call from user space
 718  */
 719 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
 720 {
 721         struct smc_sock *par = smc_sk(parent);
 722
 723         sock_hold(sk); /* sock_put in smc_accept_unlink () */
 724         spin_lock(&par->accept_q_lock);
 725         list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
 726         spin_unlock(&par->accept_q_lock);
 727         sk_acceptq_added(parent);
 728 }
 729
 730 /* remove a socket from the accept queue of its parental listening socket */
 731 static void smc_accept_unlink(struct sock *sk)
 732 {
 733         struct smc_sock *par = smc_sk(sk)->listen_smc;
 734
 735         spin_lock(&par->accept_q_lock);
 736         list_del_init(&smc_sk(sk)->accept_q);
 737         spin_unlock(&par->accept_q_lock);
 738         sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
 739         sock_put(sk); /* sock_hold in smc_accept_enqueue */
 740 }
 741
 742 /* remove a sock from the accept queue to bind it to a new socket created
 743  * for a socket accept call from user space
 744  */
 745 struct sock *smc_accept_dequeue(struct sock *parent,
 746                                 struct socket *new_sock)
 747 {
 748         struct smc_sock *isk, *n;
 749         struct sock *new_sk;
 750
 751         list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
 752                 new_sk = (struct sock *)isk;
 753
 754                 smc_accept_unlink(new_sk);
 755                 if (new_sk->sk_state == SMC_CLOSED) {
 756                         if (isk->clcsock) {
 757                                 sock_release(isk->clcsock);
 758                                 isk->clcsock = NULL;
 759                         }
 760                         new_sk->sk_prot->unhash(new_sk);
 761                         sock_put(new_sk); /* final */
 762                         continue;
 763                 }
 764                 if (new_sock)
 765                         sock_graft(new_sk, new_sock);
 766                 return new_sk;
 767         }
 768         return NULL;
 769 }
 770
 771 /* clean up for a created but never accepted sock */
 772 void smc_close_non_accepted(struct sock *sk)
 773 {
 774         struct smc_sock *smc = smc_sk(sk);
 775
 776         lock_sock(sk);
 777         if (!sk->sk_lingertime)
 778                 /* wait for peer closing */
 779                 sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
 780         if (!smc->use_fallback) {
 781                 smc_close_active(smc);
 782                 sock_set_flag(sk, SOCK_DEAD);
 783                 sk->sk_shutdown |= SHUTDOWN_MASK;
 784         }
 785         if (smc->clcsock) {
 786                 struct socket *tcp;
 787
 788                 tcp = smc->clcsock;
 789                 smc->clcsock = NULL;
 790                 sock_release(tcp);
 791         }
 792         if (smc->use_fallback) {
 793                 sock_put(sk); /* passive closing */
 794                 sk->sk_state = SMC_CLOSED;
 795         } else {
 796                 if (sk->sk_state == SMC_CLOSED)
 797                         smc_conn_free(&smc->conn);
 798         }
 799         release_sock(sk);
 800         sk->sk_prot->unhash(sk);
 801         sock_put(sk); /* final sock_put */
 802 }
 803
 804 static int smc_serv_conf_first_link(struct smc_sock *smc)
 805 {
 806         struct net *net = sock_net(smc->clcsock->sk);
 807         struct smc_link_group *lgr = smc->conn.lgr;
 808         struct smc_link *link;
 809         int rest;
 810         int rc;
 811
 812         link = &lgr->lnk[SMC_SINGLE_LINK];
 813
 814         if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
 815                 return SMC_CLC_DECL_INTERR;
 816
 817         /* send CONFIRM LINK request to client over the RoCE fabric */
 818         rc = smc_llc_send_confirm_link(link,
 819                                        link->smcibdev->mac[link->ibport - 1],
 820                                        &link->smcibdev->gid[link->ibport - 1],
 821                                        SMC_LLC_REQ);
 822         if (rc < 0)
 823                 return SMC_CLC_DECL_TCL;
 824
 825         /* receive CONFIRM LINK response from client over the RoCE fabric */
 826         rest = wait_for_completion_interruptible_timeout(
 827                 &link->llc_confirm_resp,
 828                 SMC_LLC_WAIT_FIRST_TIME);
 829         if (rest <= 0) {
 830                 struct smc_clc_msg_decline dclc;
 831
 832                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
 833                                       SMC_CLC_DECLINE);
 834                 return rc;
 835         }
 836
 837         if (link->llc_confirm_resp_rc)
 838                 return SMC_CLC_DECL_RMBE_EC;
 839
 840         /* send ADD LINK request to client over the RoCE fabric */
 841         rc = smc_llc_send_add_link(link,
 842                                    link->smcibdev->mac[link->ibport - 1],
 843                                    &link->smcibdev->gid[link->ibport - 1],
 844                                    SMC_LLC_REQ);
 845         if (rc < 0)
 846                 return SMC_CLC_DECL_TCL;
 847
 848         /* receive ADD LINK response from client over the RoCE fabric */
 849         rest = wait_for_completion_interruptible_timeout(&link->llc_add_resp,
 850                                                          SMC_LLC_WAIT_TIME);
 851         if (rest <= 0) {
 852                 struct smc_clc_msg_decline dclc;
 853
 854                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
 855                                       SMC_CLC_DECLINE);
 856                 return rc;
 857         }
 858
 859         smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
 860
 861         return 0;
 862 }
 863
 864 /* listen worker: finish */
 865 static void smc_listen_out(struct smc_sock *new_smc)
 866 {
 867         struct smc_sock *lsmc = new_smc->listen_smc;
 868         struct sock *newsmcsk = &new_smc->sk;
 869
 870         lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
 871         if (lsmc->sk.sk_state == SMC_LISTEN) {
 872                 smc_accept_enqueue(&lsmc->sk, newsmcsk);
 873         } else { /* no longer listening */
 874                 smc_close_non_accepted(newsmcsk);
 875         }
 876         release_sock(&lsmc->sk);
 877
 878         /* Wake up accept */
 879         lsmc->sk.sk_data_ready(&lsmc->sk);
 880         sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
 881 }
 882
 883 /* listen worker: finish in state connected */
 884 static void smc_listen_out_connected(struct smc_sock *new_smc)
 885 {
 886         struct sock *newsmcsk = &new_smc->sk;
 887
 888         sk_refcnt_debug_inc(newsmcsk);
 889         if (newsmcsk->sk_state == SMC_INIT)
 890                 newsmcsk->sk_state = SMC_ACTIVE;
 891
 892         smc_listen_out(new_smc);
 893 }
 894
 895 /* listen worker: finish in error state */
 896 static void smc_listen_out_err(struct smc_sock *new_smc)
 897 {
 898         struct sock *newsmcsk = &new_smc->sk;
 899
 900         if (newsmcsk->sk_state == SMC_INIT)
 901                 sock_put(&new_smc->sk); /* passive closing */
 902         newsmcsk->sk_state = SMC_CLOSED;
 903         smc_conn_free(&new_smc->conn);
 904
 905         smc_listen_out(new_smc);
 906 }
 907
 908 /* listen worker: decline and fall back if possible */
 909 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
 910                                int local_contact)
 911 {
 912         /* RDMA setup failed, switch back to TCP */
 913         if (local_contact == SMC_FIRST_CONTACT)
 914                 smc_lgr_forget(new_smc->conn.lgr);
 915         if (reason_code < 0) { /* error, no fallback possible */
 916                 smc_listen_out_err(new_smc);
 917                 return;
 918         }
 919         smc_conn_free(&new_smc->conn);
 920         new_smc->use_fallback = true;
 921         if (reason_code && reason_code != SMC_CLC_DECL_REPLY) {
 922                 if (smc_clc_send_decline(new_smc, reason_code) < 0) {
 923                         smc_listen_out_err(new_smc);
 924                         return;
 925                 }
 926         }
 927         smc_listen_out_connected(new_smc);
 928 }
 929
 930 /* listen worker: check prefixes */
 931 static int smc_listen_rdma_check(struct smc_sock *new_smc,
 932                                  struct smc_clc_msg_proposal *pclc)
 933 {
 934         struct smc_clc_msg_proposal_prefix *pclc_prfx;
 935         struct socket *newclcsock = new_smc->clcsock;
 936
 937         pclc_prfx = smc_clc_proposal_get_prefix(pclc);
 938         if (smc_clc_prfx_match(newclcsock, pclc_prfx))
 939                 return SMC_CLC_DECL_CNFERR;
 940
 941         return 0;
 942 }
 943
 944 /* listen worker: initialize connection and buffers */
 945 static int smc_listen_rdma_init(struct smc_sock *new_smc,
 946                                 struct smc_clc_msg_proposal *pclc,
 947                                 struct smc_ib_device *ibdev, u8 ibport,
 948                                 int *local_contact)
 949 {
 950         /* allocate connection / link group */
 951         *local_contact = smc_conn_create(new_smc, ibdev, ibport, &pclc->lcl, 0);
 952         if (*local_contact < 0) {
 953                 if (*local_contact == -ENOMEM)
 954                         return SMC_CLC_DECL_MEM;/* insufficient memory*/
 955                 return SMC_CLC_DECL_INTERR; /* other error */
 956         }
 957
 958         /* create send buffer and rmb */
 959         if (smc_buf_create(new_smc))
 960                 return SMC_CLC_DECL_MEM;
 961
 962         return 0;
 963 }
 964
 965 /* listen worker: register buffers */
 966 static int smc_listen_rdma_reg(struct smc_sock *new_smc, int local_contact)
 967 {
 968         struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
 969
 970         if (local_contact != SMC_FIRST_CONTACT) {
 971                 if (!new_smc->conn.rmb_desc->reused) {
 972                         if (smc_reg_rmb(link, new_smc->conn.rmb_desc, true))
 973                                 return SMC_CLC_DECL_INTERR;
 974                 }
 975         }
 976         smc_rmb_sync_sg_for_device(&new_smc->conn);
 977
 978         return 0;
 979 }
 980
 981 /* listen worker: finish RDMA setup */
 982 static void smc_listen_rdma_finish(struct smc_sock *new_smc,
 983                                    struct smc_clc_msg_accept_confirm *cclc,
 984                                    int local_contact)
 985 {
 986         struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
 987         int reason_code = 0;
 988
 989         if (local_contact == SMC_FIRST_CONTACT)
 990                 smc_link_save_peer_info(link, cclc);
 991
 992         if (smc_rmb_rtoken_handling(&new_smc->conn, cclc)) {
 993                 reason_code = SMC_CLC_DECL_INTERR;
 994                 goto decline;
 995         }
 996
 997         if (local_contact == SMC_FIRST_CONTACT) {
 998                 if (smc_ib_ready_link(link)) {
 999                         reason_code = SMC_CLC_DECL_INTERR;
1000                         goto decline;
1001                 }
1002                 /* QP confirmation over RoCE fabric */
1003                 reason_code = smc_serv_conf_first_link(new_smc);
1004                 if (reason_code)
1005                         goto decline;
1006         }
1007         return;
1008
1009 decline:
1010         mutex_unlock(&smc_create_lgr_pending);
1011         smc_listen_decline(new_smc, reason_code, local_contact);
1012 }
1013
1014 /* setup for RDMA connection of server */
1015 static void smc_listen_work(struct work_struct *work)
1016 {
1017         struct smc_sock *new_smc = container_of(work, struct smc_sock,
1018                                                 smc_listen_work);
1019         struct socket *newclcsock = new_smc->clcsock;
1020         struct smc_clc_msg_accept_confirm cclc;
1021         struct smc_clc_msg_proposal *pclc;
1022         struct smc_ib_device *ibdev;
1023         u8 buf[SMC_CLC_MAX_LEN];
1024         int local_contact = 0;
1025         int reason_code = 0;
1026         int rc = 0;
1027         u8 ibport;
1028
1029         if (new_smc->use_fallback) {
1030                 smc_listen_out_connected(new_smc);
1031                 return;
1032         }
1033
1034         /* check if peer is smc capable */
1035         if (!tcp_sk(newclcsock->sk)->syn_smc) {
1036                 new_smc->use_fallback = true;
1037                 smc_listen_out_connected(new_smc);
1038                 return;
1039         }
1040
1041         /* do inband token exchange -
1042          * wait for and receive SMC Proposal CLC message
1043          */
1044         pclc = (struct smc_clc_msg_proposal *)&buf;
1045         reason_code = smc_clc_wait_msg(new_smc, pclc, SMC_CLC_MAX_LEN,
1046                                        SMC_CLC_PROPOSAL);
1047         if (reason_code) {
1048                 smc_listen_decline(new_smc, reason_code, 0);
1049                 return;
1050         }
1051
1052         /* IPSec connections opt out of SMC-R optimizations */
1053         if (using_ipsec(new_smc)) {
1054                 smc_listen_decline(new_smc, SMC_CLC_DECL_IPSEC, 0);
1055                 return;
1056         }
1057
1058         mutex_lock(&smc_create_lgr_pending);
1059         smc_close_init(new_smc);
1060         smc_rx_init(new_smc);
1061         smc_tx_init(new_smc);
1062
1063         /* check if RDMA is available */
1064         if (smc_check_rdma(new_smc, &ibdev, &ibport) ||
1065             smc_listen_rdma_check(new_smc, pclc) ||
1066             smc_listen_rdma_init(new_smc, pclc, ibdev, ibport,
1067                                  &local_contact) ||
1068             smc_listen_rdma_reg(new_smc, local_contact)) {
1069                 /* SMC not supported, decline */
1070                 mutex_unlock(&smc_create_lgr_pending);
1071                 smc_listen_decline(new_smc, SMC_CLC_DECL_CNFERR, local_contact);
1072                 return;
1073         }
1074
1075         /* send SMC Accept CLC message */
1076         rc = smc_clc_send_accept(new_smc, local_contact);
1077         if (rc) {
1078                 mutex_unlock(&smc_create_lgr_pending);
1079                 smc_listen_decline(new_smc, rc, local_contact);
1080                 return;
1081         }
1082
1083         /* receive SMC Confirm CLC message */
1084         reason_code = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
1085                                        SMC_CLC_CONFIRM);
1086         if (reason_code) {
1087                 mutex_unlock(&smc_create_lgr_pending);
1088                 smc_listen_decline(new_smc, reason_code, local_contact);
1089                 return;
1090         }
1091
1092         /* finish worker */
1093         smc_listen_rdma_finish(new_smc, &cclc, local_contact);
1094         smc_conn_save_peer_info(new_smc, &cclc);
1095         mutex_unlock(&smc_create_lgr_pending);
1096         smc_listen_out_connected(new_smc);
1097 }
1098
1099 static void smc_tcp_listen_work(struct work_struct *work)
1100 {
1101         struct smc_sock *lsmc = container_of(work, struct smc_sock,
1102                                              tcp_listen_work);
1103         struct sock *lsk = &lsmc->sk;
1104         struct smc_sock *new_smc;
1105         int rc = 0;
1106
1107         lock_sock(lsk);
1108         while (lsk->sk_state == SMC_LISTEN) {
1109                 rc = smc_clcsock_accept(lsmc, &new_smc);
1110                 if (rc)
1111                         goto out;
1112                 if (!new_smc)
1113                         continue;
1114
1115                 new_smc->listen_smc = lsmc;
1116                 new_smc->use_fallback = lsmc->use_fallback;
1117                 sock_hold(lsk); /* sock_put in smc_listen_work */
1118                 INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
1119                 smc_copy_sock_settings_to_smc(new_smc);
1120                 sock_hold(&new_smc->sk); /* sock_put in passive closing */
1121                 if (!schedule_work(&new_smc->smc_listen_work))
1122                         sock_put(&new_smc->sk);
1123         }
1124
1125 out:
1126         release_sock(lsk);
1127         sock_put(&lsmc->sk); /* sock_hold in smc_listen */
1128 }
1129
1130 static int smc_listen(struct socket *sock, int backlog)
1131 {
1132         struct sock *sk = sock->sk;
1133         struct smc_sock *smc;
1134         int rc;
1135
1136         smc = smc_sk(sk);
1137         lock_sock(sk);
1138
1139         rc = -EINVAL;
1140         if ((sk->sk_state != SMC_INIT) && (sk->sk_state != SMC_LISTEN))
1141                 goto out;
1142
1143         rc = 0;
1144         if (sk->sk_state == SMC_LISTEN) {
1145                 sk->sk_max_ack_backlog = backlog;
1146                 goto out;
1147         }
1148         /* some socket options are handled in core, so we could not apply
1149          * them to the clc socket -- copy smc socket options to clc socket
1150          */
1151         smc_copy_sock_settings_to_clc(smc);
1152         if (!smc->use_fallback)
1153                 tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1154
1155         rc = kernel_listen(smc->clcsock, backlog);
1156         if (rc)
1157                 goto out;
1158         sk->sk_max_ack_backlog = backlog;
1159         sk->sk_ack_backlog = 0;
1160         sk->sk_state = SMC_LISTEN;
1161         INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
1162         sock_hold(sk); /* sock_hold in tcp_listen_worker */
1163         if (!schedule_work(&smc->tcp_listen_work))
1164                 sock_put(sk);
1165
1166 out:
1167         release_sock(sk);
1168         return rc;
1169 }
1170
1171 static int smc_accept(struct socket *sock, struct socket *new_sock,
1172                       int flags, bool kern)
1173 {
1174         struct sock *sk = sock->sk, *nsk;
1175         DECLARE_WAITQUEUE(wait, current);
1176         struct smc_sock *lsmc;
1177         long timeo;
1178         int rc = 0;
1179
1180         lsmc = smc_sk(sk);
1181         sock_hold(sk); /* sock_put below */
1182         lock_sock(sk);
1183
1184         if (lsmc->sk.sk_state != SMC_LISTEN) {
1185                 rc = -EINVAL;
1186                 release_sock(sk);
1187                 goto out;
1188         }
1189
1190         /* Wait for an incoming connection */
1191         timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1192         add_wait_queue_exclusive(sk_sleep(sk), &wait);
1193         while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1194                 set_current_state(TASK_INTERRUPTIBLE);
1195                 if (!timeo) {
1196                         rc = -EAGAIN;
1197                         break;
1198                 }
1199                 release_sock(sk);
1200                 timeo = schedule_timeout(timeo);
1201                 /* wakeup by sk_data_ready in smc_listen_work() */
1202                 sched_annotate_sleep();
1203                 lock_sock(sk);
1204                 if (signal_pending(current)) {
1205                         rc = sock_intr_errno(timeo);
1206                         break;
1207                 }
1208         }
1209         set_current_state(TASK_RUNNING);
1210         remove_wait_queue(sk_sleep(sk), &wait);
1211
1212         if (!rc)
1213                 rc = sock_error(nsk);
1214         release_sock(sk);
1215         if (rc)
1216                 goto out;
1217
1218         if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
1219                 /* wait till data arrives on the socket */
1220                 timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
1221                                                                 MSEC_PER_SEC);
1222                 if (smc_sk(nsk)->use_fallback) {
1223                         struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
1224
1225                         lock_sock(clcsk);
1226                         if (skb_queue_empty(&clcsk->sk_receive_queue))
1227                                 sk_wait_data(clcsk, &timeo, NULL);
1228                         release_sock(clcsk);
1229                 } else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
1230                         lock_sock(nsk);
1231                         smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
1232                         release_sock(nsk);
1233                 }
1234         }
1235
1236 out:
1237         sock_put(sk); /* sock_hold above */
1238         return rc;
1239 }
1240
1241 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1242                        int peer)
1243 {
1244         struct smc_sock *smc;
1245
1246         if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
1247             (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
1248                 return -ENOTCONN;
1249
1250         smc = smc_sk(sock->sk);
1251
1252         return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
1253 }
1254
1255 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1256 {
1257         struct sock *sk = sock->sk;
1258         struct smc_sock *smc;
1259         int rc = -EPIPE;
1260
1261         smc = smc_sk(sk);
1262         lock_sock(sk);
1263         if ((sk->sk_state != SMC_ACTIVE) &&
1264             (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1265             (sk->sk_state != SMC_INIT))
1266                 goto out;
1267
1268         if (msg->msg_flags & MSG_FASTOPEN) {
1269                 if (sk->sk_state == SMC_INIT) {
1270                         smc->use_fallback = true;
1271                 } else {
1272                         rc = -EINVAL;
1273                         goto out;
1274                 }
1275         }
1276
1277         if (smc->use_fallback)
1278                 rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
1279         else
1280                 rc = smc_tx_sendmsg(smc, msg, len);
1281 out:
1282         release_sock(sk);
1283         return rc;
1284 }
1285
1286 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1287                        int flags)
1288 {
1289         struct sock *sk = sock->sk;
1290         struct smc_sock *smc;
1291         int rc = -ENOTCONN;
1292
1293         smc = smc_sk(sk);
1294         lock_sock(sk);
1295         if ((sk->sk_state == SMC_INIT) ||
1296             (sk->sk_state == SMC_LISTEN) ||
1297             (sk->sk_state == SMC_CLOSED))
1298                 goto out;
1299
1300         if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1301                 rc = 0;
1302                 goto out;
1303         }
1304
1305         if (smc->use_fallback) {
1306                 rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
1307         } else {
1308                 msg->msg_namelen = 0;
1309                 rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
1310         }
1311
1312 out:
1313         release_sock(sk);
1314         return rc;
1315 }
1316
1317 static __poll_t smc_accept_poll(struct sock *parent)
1318 {
1319         struct smc_sock *isk = smc_sk(parent);
1320         __poll_t mask = 0;
1321
1322         spin_lock(&isk->accept_q_lock);
1323         if (!list_empty(&isk->accept_q))
1324                 mask = EPOLLIN | EPOLLRDNORM;
1325         spin_unlock(&isk->accept_q_lock);
1326
1327         return mask;
1328 }
1329
1330 static __poll_t smc_poll(struct file *file, struct socket *sock,
1331                              poll_table *wait)
1332 {
1333         struct sock *sk = sock->sk;
1334         __poll_t mask = 0;
1335         struct smc_sock *smc;
1336
1337         if (!sk)
1338                 return EPOLLNVAL;
1339
1340         smc = smc_sk(sock->sk);
1341         if ((sk->sk_state == SMC_INIT) || smc->use_fallback) {
1342                 /* delegate to CLC child sock */
1343                 mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
1344                 sk->sk_err = smc->clcsock->sk->sk_err;
1345                 if (sk->sk_err)
1346                         mask |= EPOLLERR;
1347         } else {
1348                 if (sk->sk_state != SMC_CLOSED)
1349                         sock_poll_wait(file, sk_sleep(sk), wait);
1350                 if (sk->sk_err)
1351                         mask |= EPOLLERR;
1352                 if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1353                     (sk->sk_state == SMC_CLOSED))
1354                         mask |= EPOLLHUP;
1355                 if (sk->sk_state == SMC_LISTEN) {
1356                         /* woken up by sk_data_ready in smc_listen_work() */
1357                         mask = smc_accept_poll(sk);
1358                 } else {
1359                         if (atomic_read(&smc->conn.sndbuf_space) ||
1360                             sk->sk_shutdown & SEND_SHUTDOWN) {
1361                                 mask |= EPOLLOUT | EPOLLWRNORM;
1362                         } else {
1363                                 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1364                                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1365                         }
1366                         if (atomic_read(&smc->conn.bytes_to_rcv))
1367                                 mask |= EPOLLIN | EPOLLRDNORM;
1368                         if (sk->sk_shutdown & RCV_SHUTDOWN)
1369                                 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
1370                         if (sk->sk_state == SMC_APPCLOSEWAIT1)
1371                                 mask |= EPOLLIN;
1372                 }
1373                 if (smc->conn.urg_state == SMC_URG_VALID)
1374                         mask |= EPOLLPRI;
1375         }
1376
1377         return mask;
1378 }
1379
1380 static int smc_shutdown(struct socket *sock, int how)
1381 {
1382         struct sock *sk = sock->sk;
1383         struct smc_sock *smc;
1384         int rc = -EINVAL;
1385         int rc1 = 0;
1386
1387         smc = smc_sk(sk);
1388
1389         if ((how < SHUT_RD) || (how > SHUT_RDWR))
1390                 return rc;
1391
1392         lock_sock(sk);
1393
1394         rc = -ENOTCONN;
1395         if ((sk->sk_state != SMC_LISTEN) &&
1396             (sk->sk_state != SMC_ACTIVE) &&
1397             (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
1398             (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
1399             (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1400             (sk->sk_state != SMC_APPCLOSEWAIT2) &&
1401             (sk->sk_state != SMC_APPFINCLOSEWAIT))
1402                 goto out;
1403         if (smc->use_fallback) {
1404                 rc = kernel_sock_shutdown(smc->clcsock, how);
1405                 sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
1406                 if (sk->sk_shutdown == SHUTDOWN_MASK)
1407                         sk->sk_state = SMC_CLOSED;
1408                 goto out;
1409         }
1410         switch (how) {
1411         case SHUT_RDWR:         /* shutdown in both directions */
1412                 rc = smc_close_active(smc);
1413                 break;
1414         case SHUT_WR:
1415                 rc = smc_close_shutdown_write(smc);
1416                 break;
1417         case SHUT_RD:
1418                 rc = 0;
1419                 /* nothing more to do because peer is not involved */
1420                 break;
1421         }
1422         if (smc->clcsock)
1423                 rc1 = kernel_sock_shutdown(smc->clcsock, how);
1424         /* map sock_shutdown_cmd constants to sk_shutdown value range */
1425         sk->sk_shutdown |= how + 1;
1426
1427 out:
1428         release_sock(sk);
1429         return rc ? rc : rc1;
1430 }
1431
1432 static int smc_setsockopt(struct socket *sock, int level, int optname,
1433                           char __user *optval, unsigned int optlen)
1434 {
1435         struct sock *sk = sock->sk;
1436         struct smc_sock *smc;
1437         int val, rc;
1438
1439         smc = smc_sk(sk);
1440
1441         /* generic setsockopts reaching us here always apply to the
1442          * CLC socket
1443          */
1444         rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
1445                                            optval, optlen);
1446         if (smc->clcsock->sk->sk_err) {
1447                 sk->sk_err = smc->clcsock->sk->sk_err;
1448                 sk->sk_error_report(sk);
1449         }
1450         if (rc)
1451                 return rc;
1452
1453         if (optlen < sizeof(int))
1454                 return -EINVAL;
1455         get_user(val, (int __user *)optval);
1456
1457         lock_sock(sk);
1458         switch (optname) {
1459         case TCP_ULP:
1460         case TCP_FASTOPEN:
1461         case TCP_FASTOPEN_CONNECT:
1462         case TCP_FASTOPEN_KEY:
1463         case TCP_FASTOPEN_NO_COOKIE:
1464                 /* option not supported by SMC */
1465                 if (sk->sk_state == SMC_INIT) {
1466                         smc->use_fallback = true;
1467                 } else {
1468                         if (!smc->use_fallback)
1469                                 rc = -EINVAL;
1470                 }
1471                 break;
1472         case TCP_NODELAY:
1473                 if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1474                         if (val && !smc->use_fallback)
1475                                 mod_delayed_work(system_wq, &smc->conn.tx_work,
1476                                                  0);
1477                 }
1478                 break;
1479         case TCP_CORK:
1480                 if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1481                         if (!val && !smc->use_fallback)
1482                                 mod_delayed_work(system_wq, &smc->conn.tx_work,
1483                                                  0);
1484                 }
1485                 break;
1486         case TCP_DEFER_ACCEPT:
1487                 smc->sockopt_defer_accept = val;
1488                 break;
1489         default:
1490                 break;
1491         }
1492         release_sock(sk);
1493
1494         return rc;
1495 }
1496
1497 static int smc_getsockopt(struct socket *sock, int level, int optname,
1498                           char __user *optval, int __user *optlen)
1499 {
1500         struct smc_sock *smc;
1501
1502         smc = smc_sk(sock->sk);
1503         /* socket options apply to the CLC socket */
1504         return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
1505                                              optval, optlen);
1506 }
1507
1508 static int smc_ioctl(struct socket *sock, unsigned int cmd,
1509                      unsigned long arg)
1510 {
1511         union smc_host_cursor cons, urg;
1512         struct smc_connection *conn;
1513         struct smc_sock *smc;
1514         int answ;
1515
1516         smc = smc_sk(sock->sk);
1517         conn = &smc->conn;
1518         if (smc->use_fallback) {
1519                 if (!smc->clcsock)
1520                         return -EBADF;
1521                 return smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
1522         }
1523         switch (cmd) {
1524         case SIOCINQ: /* same as FIONREAD */
1525                 if (smc->sk.sk_state == SMC_LISTEN)
1526                         return -EINVAL;
1527                 if (smc->sk.sk_state == SMC_INIT ||
1528                     smc->sk.sk_state == SMC_CLOSED)
1529                         answ = 0;
1530                 else
1531                         answ = atomic_read(&smc->conn.bytes_to_rcv);
1532                 break;
1533         case SIOCOUTQ:
1534                 /* output queue size (not send + not acked) */
1535                 if (smc->sk.sk_state == SMC_LISTEN)
1536                         return -EINVAL;
1537                 if (smc->sk.sk_state == SMC_INIT ||
1538                     smc->sk.sk_state == SMC_CLOSED)
1539                         answ = 0;
1540                 else
1541                         answ = smc->conn.sndbuf_desc->len -
1542                                         atomic_read(&smc->conn.sndbuf_space);
1543                 break;
1544         case SIOCOUTQNSD:
1545                 /* output queue size (not send only) */
1546                 if (smc->sk.sk_state == SMC_LISTEN)
1547                         return -EINVAL;
1548                 if (smc->sk.sk_state == SMC_INIT ||
1549                     smc->sk.sk_state == SMC_CLOSED)
1550                         answ = 0;
1551                 else
1552                         answ = smc_tx_prepared_sends(&smc->conn);
1553                 break;
1554         case SIOCATMARK:
1555                 if (smc->sk.sk_state == SMC_LISTEN)
1556                         return -EINVAL;
1557                 if (smc->sk.sk_state == SMC_INIT ||
1558                     smc->sk.sk_state == SMC_CLOSED) {
1559                         answ = 0;
1560                 } else {
1561                         smc_curs_write(&cons,
1562                                smc_curs_read(&conn->local_tx_ctrl.cons, conn),
1563                                        conn);
1564                         smc_curs_write(&urg,
1565                                        smc_curs_read(&conn->urg_curs, conn),
1566                                        conn);
1567                         answ = smc_curs_diff(conn->rmb_desc->len,
1568                                              &cons, &urg) == 1;
1569                 }
1570                 break;
1571         default:
1572                 return -ENOIOCTLCMD;
1573         }
1574
1575         return put_user(answ, (int __user *)arg);
1576 }
1577
1578 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
1579                             int offset, size_t size, int flags)
1580 {
1581         struct sock *sk = sock->sk;
1582         struct smc_sock *smc;
1583         int rc = -EPIPE;
1584
1585         smc = smc_sk(sk);
1586         lock_sock(sk);
1587         if (sk->sk_state != SMC_ACTIVE) {
1588                 release_sock(sk);
1589                 goto out;
1590         }
1591         release_sock(sk);
1592         if (smc->use_fallback)
1593                 rc = kernel_sendpage(smc->clcsock, page, offset,
1594                                      size, flags);
1595         else
1596                 rc = sock_no_sendpage(sock, page, offset, size, flags);
1597
1598 out:
1599         return rc;
1600 }
1601
1602 /* Map the affected portions of the rmbe into an spd, note the number of bytes
1603  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
1604  * updates till whenever a respective page has been fully processed.
1605  * Note that subsequent recv() calls have to wait till all splice() processing
1606  * completed.
1607  */
1608 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
1609                                struct pipe_inode_info *pipe, size_t len,
1610                                unsigned int flags)
1611 {
1612         struct sock *sk = sock->sk;
1613         struct smc_sock *smc;
1614         int rc = -ENOTCONN;
1615
1616         smc = smc_sk(sk);
1617         lock_sock(sk);
1618
1619         if (sk->sk_state == SMC_INIT ||
1620             sk->sk_state == SMC_LISTEN ||
1621             sk->sk_state == SMC_CLOSED)
1622                 goto out;
1623
1624         if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1625                 rc = 0;
1626                 goto out;
1627         }
1628
1629         if (smc->use_fallback) {
1630                 rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
1631                                                     pipe, len, flags);
1632         } else {
1633                 if (*ppos) {
1634                         rc = -ESPIPE;
1635                         goto out;
1636                 }
1637                 if (flags & SPLICE_F_NONBLOCK)
1638                         flags = MSG_DONTWAIT;
1639                 else
1640                         flags = 0;
1641                 rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
1642         }
1643 out:
1644         release_sock(sk);
1645
1646         return rc;
1647 }
1648
1649 /* must look like tcp */
1650 static const struct proto_ops smc_sock_ops = {
1651         .family         = PF_SMC,
1652         .owner          = THIS_MODULE,
1653         .release        = smc_release,
1654         .bind           = smc_bind,
1655         .connect        = smc_connect,
1656         .socketpair     = sock_no_socketpair,
1657         .accept         = smc_accept,
1658         .getname        = smc_getname,
1659         .poll           = smc_poll,
1660         .ioctl          = smc_ioctl,
1661         .listen         = smc_listen,
1662         .shutdown       = smc_shutdown,
1663         .setsockopt     = smc_setsockopt,
1664         .getsockopt     = smc_getsockopt,
1665         .sendmsg        = smc_sendmsg,
1666         .recvmsg        = smc_recvmsg,
1667         .mmap           = sock_no_mmap,
1668         .sendpage       = smc_sendpage,
1669         .splice_read    = smc_splice_read,
1670 };
1671
1672 static int smc_create(struct net *net, struct socket *sock, int protocol,
1673                       int kern)
1674 {
1675         int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
1676         struct smc_sock *smc;
1677         struct sock *sk;
1678         int rc;
1679
1680         rc = -ESOCKTNOSUPPORT;
1681         if (sock->type != SOCK_STREAM)
1682                 goto out;
1683
1684         rc = -EPROTONOSUPPORT;
1685         if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
1686                 goto out;
1687
1688         rc = -ENOBUFS;
1689         sock->ops = &smc_sock_ops;
1690         sk = smc_sock_alloc(net, sock, protocol);
1691         if (!sk)
1692                 goto out;
1693
1694         /* create internal TCP socket for CLC handshake and fallback */
1695         smc = smc_sk(sk);
1696         smc->use_fallback = false; /* assume rdma capability first */
1697         rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
1698                               &smc->clcsock);
1699         if (rc) {
1700                 sk_common_release(sk);
1701                 goto out;
1702         }
1703         smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
1704         smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
1705
1706 out:
1707         return rc;
1708 }
1709
1710 static const struct net_proto_family smc_sock_family_ops = {
1711         .family = PF_SMC,
1712         .owner  = THIS_MODULE,
1713         .create = smc_create,
1714 };
1715
1716 static int __init smc_init(void)
1717 {
1718         int rc;
1719
1720         rc = smc_pnet_init();
1721         if (rc)
1722                 return rc;
1723
1724         rc = smc_llc_init();
1725         if (rc) {
1726                 pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
1727                 goto out_pnet;
1728         }
1729
1730         rc = smc_cdc_init();
1731         if (rc) {
1732                 pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
1733                 goto out_pnet;
1734         }
1735
1736         rc = proto_register(&smc_proto, 1);
1737         if (rc) {
1738                 pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
1739                 goto out_pnet;
1740         }
1741
1742         rc = proto_register(&smc_proto6, 1);
1743         if (rc) {
1744                 pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
1745                 goto out_proto;
1746         }
1747
1748         rc = sock_register(&smc_sock_family_ops);
1749         if (rc) {
1750                 pr_err("%s: sock_register fails with %d\n", __func__, rc);
1751                 goto out_proto6;
1752         }
1753         INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
1754         INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
1755
1756         rc = smc_ib_register_client();
1757         if (rc) {
1758                 pr_err("%s: ib_register fails with %d\n", __func__, rc);
1759                 goto out_sock;
1760         }
1761
1762         static_branch_enable(&tcp_have_smc);
1763         return 0;
1764
1765 out_sock:
1766         sock_unregister(PF_SMC);
1767 out_proto6:
1768         proto_unregister(&smc_proto6);
1769 out_proto:
1770         proto_unregister(&smc_proto);
1771 out_pnet:
1772         smc_pnet_exit();
1773         return rc;
1774 }
1775
1776 static void __exit smc_exit(void)
1777 {
1778         smc_core_exit();
1779         static_branch_disable(&tcp_have_smc);
1780         smc_ib_unregister_client();
1781         sock_unregister(PF_SMC);
1782         proto_unregister(&smc_proto6);
1783         proto_unregister(&smc_proto);
1784         smc_pnet_exit();
1785 }
1786
1787 module_init(smc_init);
1788 module_exit(smc_exit);
1789
1790 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
1791 MODULE_DESCRIPTION("smc socket address family");
1792 MODULE_LICENSE("GPL");
1793 MODULE_ALIAS_NETPROTO(PF_SMC);