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                 if (sk->sk_state != SMC_LISTEN && sk->sk_state != SMC_INIT)
 151                         sock_put(sk); /* passive closing */
 152                 sk->sk_state = SMC_CLOSED;
 153                 sk->sk_state_change(sk);
 154         }
 155
 156         /* detach socket */
 157         sock_orphan(sk);
 158         sock->sk = NULL;
 159         if (!smc->use_fallback && sk->sk_state == SMC_CLOSED)
 160                 smc_conn_free(&smc->conn);
 161         release_sock(sk);
 162
 163         sk->sk_prot->unhash(sk);
 164         sock_put(sk); /* final sock_put */
 165 out:
 166         return rc;
 167 }
 168
 169 static void smc_destruct(struct sock *sk)
 170 {
 171         if (sk->sk_state != SMC_CLOSED)
 172                 return;
 173         if (!sock_flag(sk, SOCK_DEAD))
 174                 return;
 175
 176         sk_refcnt_debug_dec(sk);
 177 }
 178
 179 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
 180                                    int protocol)
 181 {
 182         struct smc_sock *smc;
 183         struct proto *prot;
 184         struct sock *sk;
 185
 186         prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
 187         sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
 188         if (!sk)
 189                 return NULL;
 190
 191         sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
 192         sk->sk_state = SMC_INIT;
 193         sk->sk_destruct = smc_destruct;
 194         sk->sk_protocol = protocol;
 195         smc = smc_sk(sk);
 196         INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
 197         INIT_WORK(&smc->connect_work, smc_connect_work);
 198         INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
 199         INIT_LIST_HEAD(&smc->accept_q);
 200         spin_lock_init(&smc->accept_q_lock);
 201         spin_lock_init(&smc->conn.send_lock);
 202         sk->sk_prot->hash(sk);
 203         sk_refcnt_debug_inc(sk);
 204
 205         return sk;
 206 }
 207
 208 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
 209                     int addr_len)
 210 {
 211         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
 212         struct sock *sk = sock->sk;
 213         struct smc_sock *smc;
 214         int rc;
 215
 216         smc = smc_sk(sk);
 217
 218         /* replicate tests from inet_bind(), to be safe wrt. future changes */
 219         rc = -EINVAL;
 220         if (addr_len < sizeof(struct sockaddr_in))
 221                 goto out;
 222
 223         rc = -EAFNOSUPPORT;
 224         if (addr->sin_family != AF_INET &&
 225             addr->sin_family != AF_INET6 &&
 226             addr->sin_family != AF_UNSPEC)
 227                 goto out;
 228         /* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
 229         if (addr->sin_family == AF_UNSPEC &&
 230             addr->sin_addr.s_addr != htonl(INADDR_ANY))
 231                 goto out;
 232
 233         lock_sock(sk);
 234
 235         /* Check if socket is already active */
 236         rc = -EINVAL;
 237         if (sk->sk_state != SMC_INIT)
 238                 goto out_rel;
 239
 240         smc->clcsock->sk->sk_reuse = sk->sk_reuse;
 241         rc = kernel_bind(smc->clcsock, uaddr, addr_len);
 242
 243 out_rel:
 244         release_sock(sk);
 245 out:
 246         return rc;
 247 }
 248
 249 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
 250                                    unsigned long mask)
 251 {
 252         /* options we don't get control via setsockopt for */
 253         nsk->sk_type = osk->sk_type;
 254         nsk->sk_sndbuf = osk->sk_sndbuf;
 255         nsk->sk_rcvbuf = osk->sk_rcvbuf;
 256         nsk->sk_sndtimeo = osk->sk_sndtimeo;
 257         nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
 258         nsk->sk_mark = osk->sk_mark;
 259         nsk->sk_priority = osk->sk_priority;
 260         nsk->sk_rcvlowat = osk->sk_rcvlowat;
 261         nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
 262         nsk->sk_err = osk->sk_err;
 263
 264         nsk->sk_flags &= ~mask;
 265         nsk->sk_flags |= osk->sk_flags & mask;
 266 }
 267
 268 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
 269                              (1UL << SOCK_KEEPOPEN) | \
 270                              (1UL << SOCK_LINGER) | \
 271                              (1UL << SOCK_BROADCAST) | \
 272                              (1UL << SOCK_TIMESTAMP) | \
 273                              (1UL << SOCK_DBG) | \
 274                              (1UL << SOCK_RCVTSTAMP) | \
 275                              (1UL << SOCK_RCVTSTAMPNS) | \
 276                              (1UL << SOCK_LOCALROUTE) | \
 277                              (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
 278                              (1UL << SOCK_RXQ_OVFL) | \
 279                              (1UL << SOCK_WIFI_STATUS) | \
 280                              (1UL << SOCK_NOFCS) | \
 281                              (1UL << SOCK_FILTER_LOCKED))
 282 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
 283  * clc socket (since smc is not called for these options from net/core)
 284  */
 285 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
 286 {
 287         smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
 288 }
 289
 290 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
 291                              (1UL << SOCK_KEEPOPEN) | \
 292                              (1UL << SOCK_LINGER) | \
 293                              (1UL << SOCK_DBG))
 294 /* copy only settings and flags relevant for smc from clc to smc socket */
 295 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
 296 {
 297         smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
 298 }
 299
 300 /* register a new rmb, optionally send confirm_rkey msg to register with peer */
 301 static int smc_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc,
 302                        bool conf_rkey)
 303 {
 304         /* register memory region for new rmb */
 305         if (smc_wr_reg_send(link, rmb_desc->mr_rx[SMC_SINGLE_LINK])) {
 306                 rmb_desc->regerr = 1;
 307                 return -EFAULT;
 308         }
 309         if (!conf_rkey)
 310                 return 0;
 311         /* exchange confirm_rkey msg with peer */
 312         if (smc_llc_do_confirm_rkey(link, rmb_desc)) {
 313                 rmb_desc->regerr = 1;
 314                 return -EFAULT;
 315         }
 316         return 0;
 317 }
 318
 319 static int smc_clnt_conf_first_link(struct smc_sock *smc)
 320 {
 321         struct net *net = sock_net(smc->clcsock->sk);
 322         struct smc_link_group *lgr = smc->conn.lgr;
 323         struct smc_link *link;
 324         int rest;
 325         int rc;
 326
 327         link = &lgr->lnk[SMC_SINGLE_LINK];
 328         /* receive CONFIRM LINK request from server over RoCE fabric */
 329         rest = wait_for_completion_interruptible_timeout(
 330                 &link->llc_confirm,
 331                 SMC_LLC_WAIT_FIRST_TIME);
 332         if (rest <= 0) {
 333                 struct smc_clc_msg_decline dclc;
 334
 335                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
 336                                       SMC_CLC_DECLINE);
 337                 return rc;
 338         }
 339
 340         if (link->llc_confirm_rc)
 341                 return SMC_CLC_DECL_RMBE_EC;
 342
 343         rc = smc_ib_modify_qp_rts(link);
 344         if (rc)
 345                 return SMC_CLC_DECL_INTERR;
 346
 347         smc_wr_remember_qp_attr(link);
 348
 349         if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
 350                 return SMC_CLC_DECL_INTERR;
 351
 352         /* send CONFIRM LINK response over RoCE fabric */
 353         rc = smc_llc_send_confirm_link(link,
 354                                        link->smcibdev->mac[link->ibport - 1],
 355                                        &link->smcibdev->gid[link->ibport - 1],
 356                                        SMC_LLC_RESP);
 357         if (rc < 0)
 358                 return SMC_CLC_DECL_TCL;
 359
 360         /* receive ADD LINK request from server over RoCE fabric */
 361         rest = wait_for_completion_interruptible_timeout(&link->llc_add,
 362                                                          SMC_LLC_WAIT_TIME);
 363         if (rest <= 0) {
 364                 struct smc_clc_msg_decline dclc;
 365
 366                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
 367                                       SMC_CLC_DECLINE);
 368                 return rc;
 369         }
 370
 371         /* send add link reject message, only one link supported for now */
 372         rc = smc_llc_send_add_link(link,
 373                                    link->smcibdev->mac[link->ibport - 1],
 374                                    &link->smcibdev->gid[link->ibport - 1],
 375                                    SMC_LLC_RESP);
 376         if (rc < 0)
 377                 return SMC_CLC_DECL_TCL;
 378
 379         smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
 380
 381         return 0;
 382 }
 383
 384 static void smc_conn_save_peer_info(struct smc_sock *smc,
 385                                     struct smc_clc_msg_accept_confirm *clc)
 386 {
 387         int bufsize = smc_uncompress_bufsize(clc->rmbe_size);
 388
 389         smc->conn.peer_rmbe_idx = clc->rmbe_idx;
 390         smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
 391         smc->conn.peer_rmbe_size = bufsize;
 392         atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
 393         smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
 394 }
 395
 396 static void smc_link_save_peer_info(struct smc_link *link,
 397                                     struct smc_clc_msg_accept_confirm *clc)
 398 {
 399         link->peer_qpn = ntoh24(clc->qpn);
 400         memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
 401         memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
 402         link->peer_psn = ntoh24(clc->psn);
 403         link->peer_mtu = clc->qp_mtu;
 404 }
 405
 406 /* fall back during connect */
 407 static int smc_connect_fallback(struct smc_sock *smc)
 408 {
 409         smc->use_fallback = true;
 410         smc_copy_sock_settings_to_clc(smc);
 411         if (smc->sk.sk_state == SMC_INIT)
 412                 smc->sk.sk_state = SMC_ACTIVE;
 413         return 0;
 414 }
 415
 416 /* decline and fall back during connect */
 417 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code)
 418 {
 419         int rc;
 420
 421         if (reason_code < 0) { /* error, fallback is not possible */
 422                 if (smc->sk.sk_state == SMC_INIT)
 423                         sock_put(&smc->sk); /* passive closing */
 424                 return reason_code;
 425         }
 426         if (reason_code != SMC_CLC_DECL_REPLY) {
 427                 rc = smc_clc_send_decline(smc, reason_code);
 428                 if (rc < 0) {
 429                         if (smc->sk.sk_state == SMC_INIT)
 430                                 sock_put(&smc->sk); /* passive closing */
 431                         return rc;
 432                 }
 433         }
 434         return smc_connect_fallback(smc);
 435 }
 436
 437 /* abort connecting */
 438 static int smc_connect_abort(struct smc_sock *smc, int reason_code,
 439                              int local_contact)
 440 {
 441         if (local_contact == SMC_FIRST_CONTACT)
 442                 smc_lgr_forget(smc->conn.lgr);
 443         mutex_unlock(&smc_create_lgr_pending);
 444         smc_conn_free(&smc->conn);
 445         return reason_code;
 446 }
 447
 448 /* check if there is a rdma device available for this connection. */
 449 /* called for connect and listen */
 450 static int smc_check_rdma(struct smc_sock *smc, struct smc_ib_device **ibdev,
 451                           u8 *ibport)
 452 {
 453         int reason_code = 0;
 454
 455         /* PNET table look up: search active ib_device and port
 456          * within same PNETID that also contains the ethernet device
 457          * used for the internal TCP socket
 458          */
 459         smc_pnet_find_roce_resource(smc->clcsock->sk, ibdev, ibport);
 460         if (!(*ibdev))
 461                 reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
 462
 463         return reason_code;
 464 }
 465
 466 /* CLC handshake during connect */
 467 static int smc_connect_clc(struct smc_sock *smc,
 468                            struct smc_clc_msg_accept_confirm *aclc,
 469                            struct smc_ib_device *ibdev, u8 ibport)
 470 {
 471         int rc = 0;
 472
 473         /* do inband token exchange */
 474         rc = smc_clc_send_proposal(smc, ibdev, ibport);
 475         if (rc)
 476                 return rc;
 477         /* receive SMC Accept CLC message */
 478         return smc_clc_wait_msg(smc, aclc, sizeof(*aclc), SMC_CLC_ACCEPT);
 479 }
 480
 481 /* setup for RDMA connection of client */
 482 static int smc_connect_rdma(struct smc_sock *smc,
 483                             struct smc_clc_msg_accept_confirm *aclc,
 484                             struct smc_ib_device *ibdev, u8 ibport)
 485 {
 486         int local_contact = SMC_FIRST_CONTACT;
 487         struct smc_link *link;
 488         int reason_code = 0;
 489
 490         mutex_lock(&smc_create_lgr_pending);
 491         local_contact = smc_conn_create(smc, ibdev, ibport, &aclc->lcl,
 492                                         aclc->hdr.flag);
 493         if (local_contact < 0) {
 494                 if (local_contact == -ENOMEM)
 495                         reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
 496                 else if (local_contact == -ENOLINK)
 497                         reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
 498                 else
 499                         reason_code = SMC_CLC_DECL_INTERR; /* other error */
 500                 return smc_connect_abort(smc, reason_code, 0);
 501         }
 502         link = &smc->conn.lgr->lnk[SMC_SINGLE_LINK];
 503
 504         smc_conn_save_peer_info(smc, aclc);
 505
 506         /* create send buffer and rmb */
 507         if (smc_buf_create(smc))
 508                 return smc_connect_abort(smc, SMC_CLC_DECL_MEM, local_contact);
 509
 510         if (local_contact == SMC_FIRST_CONTACT)
 511                 smc_link_save_peer_info(link, aclc);
 512
 513         if (smc_rmb_rtoken_handling(&smc->conn, aclc))
 514                 return smc_connect_abort(smc, SMC_CLC_DECL_INTERR,
 515                                          local_contact);
 516
 517         smc_close_init(smc);
 518         smc_rx_init(smc);
 519
 520         if (local_contact == SMC_FIRST_CONTACT) {
 521                 if (smc_ib_ready_link(link))
 522                         return smc_connect_abort(smc, SMC_CLC_DECL_INTERR,
 523                                                  local_contact);
 524         } else {
 525                 if (!smc->conn.rmb_desc->reused &&
 526                     smc_reg_rmb(link, smc->conn.rmb_desc, true))
 527                         return smc_connect_abort(smc, SMC_CLC_DECL_INTERR,
 528                                                  local_contact);
 529         }
 530         smc_rmb_sync_sg_for_device(&smc->conn);
 531
 532         reason_code = smc_clc_send_confirm(smc);
 533         if (reason_code)
 534                 return smc_connect_abort(smc, reason_code, local_contact);
 535
 536         smc_tx_init(smc);
 537
 538         if (local_contact == SMC_FIRST_CONTACT) {
 539                 /* QP confirmation over RoCE fabric */
 540                 reason_code = smc_clnt_conf_first_link(smc);
 541                 if (reason_code)
 542                         return smc_connect_abort(smc, reason_code,
 543                                                  local_contact);
 544         }
 545         mutex_unlock(&smc_create_lgr_pending);
 546
 547         smc_copy_sock_settings_to_clc(smc);
 548         if (smc->sk.sk_state == SMC_INIT)
 549                 smc->sk.sk_state = SMC_ACTIVE;
 550
 551         return 0;
 552 }
 553
 554 /* perform steps before actually connecting */
 555 static int __smc_connect(struct smc_sock *smc)
 556 {
 557         struct smc_clc_msg_accept_confirm aclc;
 558         struct smc_ib_device *ibdev;
 559         int rc = 0;
 560         u8 ibport;
 561
 562         sock_hold(&smc->sk); /* sock put in passive closing */
 563
 564         if (smc->use_fallback)
 565                 return smc_connect_fallback(smc);
 566
 567         /* if peer has not signalled SMC-capability, fall back */
 568         if (!tcp_sk(smc->clcsock->sk)->syn_smc)
 569                 return smc_connect_fallback(smc);
 570
 571         /* IPSec connections opt out of SMC-R optimizations */
 572         if (using_ipsec(smc))
 573                 return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC);
 574
 575         /* check if a RDMA device is available; if not, fall back */
 576         if (smc_check_rdma(smc, &ibdev, &ibport))
 577                 return smc_connect_decline_fallback(smc, SMC_CLC_DECL_CNFERR);
 578
 579         /* perform CLC handshake */
 580         rc = smc_connect_clc(smc, &aclc, ibdev, ibport);
 581         if (rc)
 582                 return smc_connect_decline_fallback(smc, rc);
 583
 584         /* connect using rdma */
 585         rc = smc_connect_rdma(smc, &aclc, ibdev, ibport);
 586         if (rc)
 587                 return smc_connect_decline_fallback(smc, rc);
 588
 589         return 0;
 590 }
 591
 592 static void smc_connect_work(struct work_struct *work)
 593 {
 594         struct smc_sock *smc = container_of(work, struct smc_sock,
 595                                             connect_work);
 596         int rc;
 597
 598         lock_sock(&smc->sk);
 599         rc = kernel_connect(smc->clcsock, &smc->connect_info->addr,
 600                             smc->connect_info->alen, smc->connect_info->flags);
 601         if (smc->clcsock->sk->sk_err) {
 602                 smc->sk.sk_err = smc->clcsock->sk->sk_err;
 603                 goto out;
 604         }
 605         if (rc < 0) {
 606                 smc->sk.sk_err = -rc;
 607                 goto out;
 608         }
 609
 610         rc = __smc_connect(smc);
 611         if (rc < 0)
 612                 smc->sk.sk_err = -rc;
 613
 614 out:
 615         smc->sk.sk_state_change(&smc->sk);
 616         kfree(smc->connect_info);
 617         smc->connect_info = NULL;
 618         release_sock(&smc->sk);
 619 }
 620
 621 static int smc_connect(struct socket *sock, struct sockaddr *addr,
 622                        int alen, int flags)
 623 {
 624         struct sock *sk = sock->sk;
 625         struct smc_sock *smc;
 626         int rc = -EINVAL;
 627
 628         smc = smc_sk(sk);
 629
 630         /* separate smc parameter checking to be safe */
 631         if (alen < sizeof(addr->sa_family))
 632                 goto out_err;
 633         if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
 634                 goto out_err;
 635
 636         lock_sock(sk);
 637         switch (sk->sk_state) {
 638         default:
 639                 goto out;
 640         case SMC_ACTIVE:
 641                 rc = -EISCONN;
 642                 goto out;
 643         case SMC_INIT:
 644                 rc = 0;
 645                 break;
 646         }
 647
 648         smc_copy_sock_settings_to_clc(smc);
 649         tcp_sk(smc->clcsock->sk)->syn_smc = 1;
 650         if (flags & O_NONBLOCK) {
 651                 if (smc->connect_info) {
 652                         rc = -EALREADY;
 653                         goto out;
 654                 }
 655                 smc->connect_info = kzalloc(alen + 2 * sizeof(int), GFP_KERNEL);
 656                 if (!smc->connect_info) {
 657                         rc = -ENOMEM;
 658                         goto out;
 659                 }
 660                 smc->connect_info->alen = alen;
 661                 smc->connect_info->flags = flags ^ O_NONBLOCK;
 662                 memcpy(&smc->connect_info->addr, addr, alen);
 663                 schedule_work(&smc->connect_work);
 664                 rc = -EINPROGRESS;
 665         } else {
 666                 rc = kernel_connect(smc->clcsock, addr, alen, flags);
 667                 if (rc)
 668                         goto out;
 669
 670                 rc = __smc_connect(smc);
 671                 if (rc < 0)
 672                         goto out;
 673                 else
 674                         rc = 0; /* success cases including fallback */
 675         }
 676
 677 out:
 678         release_sock(sk);
 679 out_err:
 680         return rc;
 681 }
 682
 683 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
 684 {
 685         struct socket *new_clcsock = NULL;
 686         struct sock *lsk = &lsmc->sk;
 687         struct sock *new_sk;
 688         int rc;
 689
 690         release_sock(lsk);
 691         new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
 692         if (!new_sk) {
 693                 rc = -ENOMEM;
 694                 lsk->sk_err = ENOMEM;
 695                 *new_smc = NULL;
 696                 lock_sock(lsk);
 697                 goto out;
 698         }
 699         *new_smc = smc_sk(new_sk);
 700
 701         rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
 702         lock_sock(lsk);
 703         if  (rc < 0)
 704                 lsk->sk_err = -rc;
 705         if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
 706                 if (new_clcsock)
 707                         sock_release(new_clcsock);
 708                 new_sk->sk_state = SMC_CLOSED;
 709                 sock_set_flag(new_sk, SOCK_DEAD);
 710                 new_sk->sk_prot->unhash(new_sk);
 711                 sock_put(new_sk); /* final */
 712                 *new_smc = NULL;
 713                 goto out;
 714         }
 715
 716         (*new_smc)->clcsock = new_clcsock;
 717 out:
 718         return rc;
 719 }
 720
 721 /* add a just created sock to the accept queue of the listen sock as
 722  * candidate for a following socket accept call from user space
 723  */
 724 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
 725 {
 726         struct smc_sock *par = smc_sk(parent);
 727
 728         sock_hold(sk); /* sock_put in smc_accept_unlink () */
 729         spin_lock(&par->accept_q_lock);
 730         list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
 731         spin_unlock(&par->accept_q_lock);
 732         sk_acceptq_added(parent);
 733 }
 734
 735 /* remove a socket from the accept queue of its parental listening socket */
 736 static void smc_accept_unlink(struct sock *sk)
 737 {
 738         struct smc_sock *par = smc_sk(sk)->listen_smc;
 739
 740         spin_lock(&par->accept_q_lock);
 741         list_del_init(&smc_sk(sk)->accept_q);
 742         spin_unlock(&par->accept_q_lock);
 743         sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
 744         sock_put(sk); /* sock_hold in smc_accept_enqueue */
 745 }
 746
 747 /* remove a sock from the accept queue to bind it to a new socket created
 748  * for a socket accept call from user space
 749  */
 750 struct sock *smc_accept_dequeue(struct sock *parent,
 751                                 struct socket *new_sock)
 752 {
 753         struct smc_sock *isk, *n;
 754         struct sock *new_sk;
 755
 756         list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
 757                 new_sk = (struct sock *)isk;
 758
 759                 smc_accept_unlink(new_sk);
 760                 if (new_sk->sk_state == SMC_CLOSED) {
 761                         if (isk->clcsock) {
 762                                 sock_release(isk->clcsock);
 763                                 isk->clcsock = NULL;
 764                         }
 765                         new_sk->sk_prot->unhash(new_sk);
 766                         sock_put(new_sk); /* final */
 767                         continue;
 768                 }
 769                 if (new_sock)
 770                         sock_graft(new_sk, new_sock);
 771                 return new_sk;
 772         }
 773         return NULL;
 774 }
 775
 776 /* clean up for a created but never accepted sock */
 777 void smc_close_non_accepted(struct sock *sk)
 778 {
 779         struct smc_sock *smc = smc_sk(sk);
 780
 781         lock_sock(sk);
 782         if (!sk->sk_lingertime)
 783                 /* wait for peer closing */
 784                 sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
 785         if (!smc->use_fallback) {
 786                 smc_close_active(smc);
 787                 sock_set_flag(sk, SOCK_DEAD);
 788                 sk->sk_shutdown |= SHUTDOWN_MASK;
 789         }
 790         if (smc->clcsock) {
 791                 struct socket *tcp;
 792
 793                 tcp = smc->clcsock;
 794                 smc->clcsock = NULL;
 795                 sock_release(tcp);
 796         }
 797         if (smc->use_fallback) {
 798                 sock_put(sk); /* passive closing */
 799                 sk->sk_state = SMC_CLOSED;
 800         } else {
 801                 if (sk->sk_state == SMC_CLOSED)
 802                         smc_conn_free(&smc->conn);
 803         }
 804         release_sock(sk);
 805         sk->sk_prot->unhash(sk);
 806         sock_put(sk); /* final sock_put */
 807 }
 808
 809 static int smc_serv_conf_first_link(struct smc_sock *smc)
 810 {
 811         struct net *net = sock_net(smc->clcsock->sk);
 812         struct smc_link_group *lgr = smc->conn.lgr;
 813         struct smc_link *link;
 814         int rest;
 815         int rc;
 816
 817         link = &lgr->lnk[SMC_SINGLE_LINK];
 818
 819         if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
 820                 return SMC_CLC_DECL_INTERR;
 821
 822         /* send CONFIRM LINK request to client over the RoCE fabric */
 823         rc = smc_llc_send_confirm_link(link,
 824                                        link->smcibdev->mac[link->ibport - 1],
 825                                        &link->smcibdev->gid[link->ibport - 1],
 826                                        SMC_LLC_REQ);
 827         if (rc < 0)
 828                 return SMC_CLC_DECL_TCL;
 829
 830         /* receive CONFIRM LINK response from client over the RoCE fabric */
 831         rest = wait_for_completion_interruptible_timeout(
 832                 &link->llc_confirm_resp,
 833                 SMC_LLC_WAIT_FIRST_TIME);
 834         if (rest <= 0) {
 835                 struct smc_clc_msg_decline dclc;
 836
 837                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
 838                                       SMC_CLC_DECLINE);
 839                 return rc;
 840         }
 841
 842         if (link->llc_confirm_resp_rc)
 843                 return SMC_CLC_DECL_RMBE_EC;
 844
 845         /* send ADD LINK request to client over the RoCE fabric */
 846         rc = smc_llc_send_add_link(link,
 847                                    link->smcibdev->mac[link->ibport - 1],
 848                                    &link->smcibdev->gid[link->ibport - 1],
 849                                    SMC_LLC_REQ);
 850         if (rc < 0)
 851                 return SMC_CLC_DECL_TCL;
 852
 853         /* receive ADD LINK response from client over the RoCE fabric */
 854         rest = wait_for_completion_interruptible_timeout(&link->llc_add_resp,
 855                                                          SMC_LLC_WAIT_TIME);
 856         if (rest <= 0) {
 857                 struct smc_clc_msg_decline dclc;
 858
 859                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
 860                                       SMC_CLC_DECLINE);
 861                 return rc;
 862         }
 863
 864         smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
 865
 866         return 0;
 867 }
 868
 869 /* listen worker: finish */
 870 static void smc_listen_out(struct smc_sock *new_smc)
 871 {
 872         struct smc_sock *lsmc = new_smc->listen_smc;
 873         struct sock *newsmcsk = &new_smc->sk;
 874
 875         lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
 876         if (lsmc->sk.sk_state == SMC_LISTEN) {
 877                 smc_accept_enqueue(&lsmc->sk, newsmcsk);
 878         } else { /* no longer listening */
 879                 smc_close_non_accepted(newsmcsk);
 880         }
 881         release_sock(&lsmc->sk);
 882
 883         /* Wake up accept */
 884         lsmc->sk.sk_data_ready(&lsmc->sk);
 885         sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
 886 }
 887
 888 /* listen worker: finish in state connected */
 889 static void smc_listen_out_connected(struct smc_sock *new_smc)
 890 {
 891         struct sock *newsmcsk = &new_smc->sk;
 892
 893         sk_refcnt_debug_inc(newsmcsk);
 894         if (newsmcsk->sk_state == SMC_INIT)
 895                 newsmcsk->sk_state = SMC_ACTIVE;
 896
 897         smc_listen_out(new_smc);
 898 }
 899
 900 /* listen worker: finish in error state */
 901 static void smc_listen_out_err(struct smc_sock *new_smc)
 902 {
 903         struct sock *newsmcsk = &new_smc->sk;
 904
 905         if (newsmcsk->sk_state == SMC_INIT)
 906                 sock_put(&new_smc->sk); /* passive closing */
 907         newsmcsk->sk_state = SMC_CLOSED;
 908         smc_conn_free(&new_smc->conn);
 909
 910         smc_listen_out(new_smc);
 911 }
 912
 913 /* listen worker: decline and fall back if possible */
 914 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
 915                                int local_contact)
 916 {
 917         /* RDMA setup failed, switch back to TCP */
 918         if (local_contact == SMC_FIRST_CONTACT)
 919                 smc_lgr_forget(new_smc->conn.lgr);
 920         if (reason_code < 0) { /* error, no fallback possible */
 921                 smc_listen_out_err(new_smc);
 922                 return;
 923         }
 924         smc_conn_free(&new_smc->conn);
 925         new_smc->use_fallback = true;
 926         if (reason_code && reason_code != SMC_CLC_DECL_REPLY) {
 927                 if (smc_clc_send_decline(new_smc, reason_code) < 0) {
 928                         smc_listen_out_err(new_smc);
 929                         return;
 930                 }
 931         }
 932         smc_listen_out_connected(new_smc);
 933 }
 934
 935 /* listen worker: check prefixes */
 936 static int smc_listen_rdma_check(struct smc_sock *new_smc,
 937                                  struct smc_clc_msg_proposal *pclc)
 938 {
 939         struct smc_clc_msg_proposal_prefix *pclc_prfx;
 940         struct socket *newclcsock = new_smc->clcsock;
 941
 942         pclc_prfx = smc_clc_proposal_get_prefix(pclc);
 943         if (smc_clc_prfx_match(newclcsock, pclc_prfx))
 944                 return SMC_CLC_DECL_CNFERR;
 945
 946         return 0;
 947 }
 948
 949 /* listen worker: initialize connection and buffers */
 950 static int smc_listen_rdma_init(struct smc_sock *new_smc,
 951                                 struct smc_clc_msg_proposal *pclc,
 952                                 struct smc_ib_device *ibdev, u8 ibport,
 953                                 int *local_contact)
 954 {
 955         /* allocate connection / link group */
 956         *local_contact = smc_conn_create(new_smc, ibdev, ibport, &pclc->lcl, 0);
 957         if (*local_contact < 0) {
 958                 if (*local_contact == -ENOMEM)
 959                         return SMC_CLC_DECL_MEM;/* insufficient memory*/
 960                 return SMC_CLC_DECL_INTERR; /* other error */
 961         }
 962
 963         /* create send buffer and rmb */
 964         if (smc_buf_create(new_smc))
 965                 return SMC_CLC_DECL_MEM;
 966
 967         return 0;
 968 }
 969
 970 /* listen worker: register buffers */
 971 static int smc_listen_rdma_reg(struct smc_sock *new_smc, int local_contact)
 972 {
 973         struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
 974
 975         if (local_contact != SMC_FIRST_CONTACT) {
 976                 if (!new_smc->conn.rmb_desc->reused) {
 977                         if (smc_reg_rmb(link, new_smc->conn.rmb_desc, true))
 978                                 return SMC_CLC_DECL_INTERR;
 979                 }
 980         }
 981         smc_rmb_sync_sg_for_device(&new_smc->conn);
 982
 983         return 0;
 984 }
 985
 986 /* listen worker: finish RDMA setup */
 987 static void smc_listen_rdma_finish(struct smc_sock *new_smc,
 988                                    struct smc_clc_msg_accept_confirm *cclc,
 989                                    int local_contact)
 990 {
 991         struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
 992         int reason_code = 0;
 993
 994         if (local_contact == SMC_FIRST_CONTACT)
 995                 smc_link_save_peer_info(link, cclc);
 996
 997         if (smc_rmb_rtoken_handling(&new_smc->conn, cclc)) {
 998                 reason_code = SMC_CLC_DECL_INTERR;
 999                 goto decline;
1000         }
1001
1002         if (local_contact == SMC_FIRST_CONTACT) {
1003                 if (smc_ib_ready_link(link)) {
1004                         reason_code = SMC_CLC_DECL_INTERR;
1005                         goto decline;
1006                 }
1007                 /* QP confirmation over RoCE fabric */
1008                 reason_code = smc_serv_conf_first_link(new_smc);
1009                 if (reason_code)
1010                         goto decline;
1011         }
1012         return;
1013
1014 decline:
1015         mutex_unlock(&smc_create_lgr_pending);
1016         smc_listen_decline(new_smc, reason_code, local_contact);
1017 }
1018
1019 /* setup for RDMA connection of server */
1020 static void smc_listen_work(struct work_struct *work)
1021 {
1022         struct smc_sock *new_smc = container_of(work, struct smc_sock,
1023                                                 smc_listen_work);
1024         struct socket *newclcsock = new_smc->clcsock;
1025         struct smc_clc_msg_accept_confirm cclc;
1026         struct smc_clc_msg_proposal *pclc;
1027         struct smc_ib_device *ibdev;
1028         u8 buf[SMC_CLC_MAX_LEN];
1029         int local_contact = 0;
1030         int reason_code = 0;
1031         int rc = 0;
1032         u8 ibport;
1033
1034         if (new_smc->use_fallback) {
1035                 smc_listen_out_connected(new_smc);
1036                 return;
1037         }
1038
1039         /* check if peer is smc capable */
1040         if (!tcp_sk(newclcsock->sk)->syn_smc) {
1041                 new_smc->use_fallback = true;
1042                 smc_listen_out_connected(new_smc);
1043                 return;
1044         }
1045
1046         /* do inband token exchange -
1047          * wait for and receive SMC Proposal CLC message
1048          */
1049         pclc = (struct smc_clc_msg_proposal *)&buf;
1050         reason_code = smc_clc_wait_msg(new_smc, pclc, SMC_CLC_MAX_LEN,
1051                                        SMC_CLC_PROPOSAL);
1052         if (reason_code) {
1053                 smc_listen_decline(new_smc, reason_code, 0);
1054                 return;
1055         }
1056
1057         /* IPSec connections opt out of SMC-R optimizations */
1058         if (using_ipsec(new_smc)) {
1059                 smc_listen_decline(new_smc, SMC_CLC_DECL_IPSEC, 0);
1060                 return;
1061         }
1062
1063         mutex_lock(&smc_create_lgr_pending);
1064         smc_close_init(new_smc);
1065         smc_rx_init(new_smc);
1066         smc_tx_init(new_smc);
1067
1068         /* check if RDMA is available */
1069         if (smc_check_rdma(new_smc, &ibdev, &ibport) ||
1070             smc_listen_rdma_check(new_smc, pclc) ||
1071             smc_listen_rdma_init(new_smc, pclc, ibdev, ibport,
1072                                  &local_contact) ||
1073             smc_listen_rdma_reg(new_smc, local_contact)) {
1074                 /* SMC not supported, decline */
1075                 mutex_unlock(&smc_create_lgr_pending);
1076                 smc_listen_decline(new_smc, SMC_CLC_DECL_CNFERR, local_contact);
1077                 return;
1078         }
1079
1080         /* send SMC Accept CLC message */
1081         rc = smc_clc_send_accept(new_smc, local_contact);
1082         if (rc) {
1083                 mutex_unlock(&smc_create_lgr_pending);
1084                 smc_listen_decline(new_smc, rc, local_contact);
1085                 return;
1086         }
1087
1088         /* receive SMC Confirm CLC message */
1089         reason_code = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
1090                                        SMC_CLC_CONFIRM);
1091         if (reason_code) {
1092                 mutex_unlock(&smc_create_lgr_pending);
1093                 smc_listen_decline(new_smc, reason_code, local_contact);
1094                 return;
1095         }
1096
1097         /* finish worker */
1098         smc_listen_rdma_finish(new_smc, &cclc, local_contact);
1099         smc_conn_save_peer_info(new_smc, &cclc);
1100         mutex_unlock(&smc_create_lgr_pending);
1101         smc_listen_out_connected(new_smc);
1102 }
1103
1104 static void smc_tcp_listen_work(struct work_struct *work)
1105 {
1106         struct smc_sock *lsmc = container_of(work, struct smc_sock,
1107                                              tcp_listen_work);
1108         struct sock *lsk = &lsmc->sk;
1109         struct smc_sock *new_smc;
1110         int rc = 0;
1111
1112         lock_sock(lsk);
1113         while (lsk->sk_state == SMC_LISTEN) {
1114                 rc = smc_clcsock_accept(lsmc, &new_smc);
1115                 if (rc)
1116                         goto out;
1117                 if (!new_smc)
1118                         continue;
1119
1120                 new_smc->listen_smc = lsmc;
1121                 new_smc->use_fallback = lsmc->use_fallback;
1122                 sock_hold(lsk); /* sock_put in smc_listen_work */
1123                 INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
1124                 smc_copy_sock_settings_to_smc(new_smc);
1125                 new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
1126                 new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
1127                 sock_hold(&new_smc->sk); /* sock_put in passive closing */
1128                 if (!schedule_work(&new_smc->smc_listen_work))
1129                         sock_put(&new_smc->sk);
1130         }
1131
1132 out:
1133         release_sock(lsk);
1134         sock_put(&lsmc->sk); /* sock_hold in smc_listen */
1135 }
1136
1137 static int smc_listen(struct socket *sock, int backlog)
1138 {
1139         struct sock *sk = sock->sk;
1140         struct smc_sock *smc;
1141         int rc;
1142
1143         smc = smc_sk(sk);
1144         lock_sock(sk);
1145
1146         rc = -EINVAL;
1147         if ((sk->sk_state != SMC_INIT) && (sk->sk_state != SMC_LISTEN))
1148                 goto out;
1149
1150         rc = 0;
1151         if (sk->sk_state == SMC_LISTEN) {
1152                 sk->sk_max_ack_backlog = backlog;
1153                 goto out;
1154         }
1155         /* some socket options are handled in core, so we could not apply
1156          * them to the clc socket -- copy smc socket options to clc socket
1157          */
1158         smc_copy_sock_settings_to_clc(smc);
1159         if (!smc->use_fallback)
1160                 tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1161
1162         rc = kernel_listen(smc->clcsock, backlog);
1163         if (rc)
1164                 goto out;
1165         sk->sk_max_ack_backlog = backlog;
1166         sk->sk_ack_backlog = 0;
1167         sk->sk_state = SMC_LISTEN;
1168         INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
1169         sock_hold(sk); /* sock_hold in tcp_listen_worker */
1170         if (!schedule_work(&smc->tcp_listen_work))
1171                 sock_put(sk);
1172
1173 out:
1174         release_sock(sk);
1175         return rc;
1176 }
1177
1178 static int smc_accept(struct socket *sock, struct socket *new_sock,
1179                       int flags, bool kern)
1180 {
1181         struct sock *sk = sock->sk, *nsk;
1182         DECLARE_WAITQUEUE(wait, current);
1183         struct smc_sock *lsmc;
1184         long timeo;
1185         int rc = 0;
1186
1187         lsmc = smc_sk(sk);
1188         sock_hold(sk); /* sock_put below */
1189         lock_sock(sk);
1190
1191         if (lsmc->sk.sk_state != SMC_LISTEN) {
1192                 rc = -EINVAL;
1193                 release_sock(sk);
1194                 goto out;
1195         }
1196
1197         /* Wait for an incoming connection */
1198         timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1199         add_wait_queue_exclusive(sk_sleep(sk), &wait);
1200         while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1201                 set_current_state(TASK_INTERRUPTIBLE);
1202                 if (!timeo) {
1203                         rc = -EAGAIN;
1204                         break;
1205                 }
1206                 release_sock(sk);
1207                 timeo = schedule_timeout(timeo);
1208                 /* wakeup by sk_data_ready in smc_listen_work() */
1209                 sched_annotate_sleep();
1210                 lock_sock(sk);
1211                 if (signal_pending(current)) {
1212                         rc = sock_intr_errno(timeo);
1213                         break;
1214                 }
1215         }
1216         set_current_state(TASK_RUNNING);
1217         remove_wait_queue(sk_sleep(sk), &wait);
1218
1219         if (!rc)
1220                 rc = sock_error(nsk);
1221         release_sock(sk);
1222         if (rc)
1223                 goto out;
1224
1225         if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
1226                 /* wait till data arrives on the socket */
1227                 timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
1228                                                                 MSEC_PER_SEC);
1229                 if (smc_sk(nsk)->use_fallback) {
1230                         struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
1231
1232                         lock_sock(clcsk);
1233                         if (skb_queue_empty(&clcsk->sk_receive_queue))
1234                                 sk_wait_data(clcsk, &timeo, NULL);
1235                         release_sock(clcsk);
1236                 } else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
1237                         lock_sock(nsk);
1238                         smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
1239                         release_sock(nsk);
1240                 }
1241         }
1242
1243 out:
1244         sock_put(sk); /* sock_hold above */
1245         return rc;
1246 }
1247
1248 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1249                        int peer)
1250 {
1251         struct smc_sock *smc;
1252
1253         if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
1254             (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
1255                 return -ENOTCONN;
1256
1257         smc = smc_sk(sock->sk);
1258
1259         return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
1260 }
1261
1262 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1263 {
1264         struct sock *sk = sock->sk;
1265         struct smc_sock *smc;
1266         int rc = -EPIPE;
1267
1268         smc = smc_sk(sk);
1269         lock_sock(sk);
1270         if ((sk->sk_state != SMC_ACTIVE) &&
1271             (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1272             (sk->sk_state != SMC_INIT))
1273                 goto out;
1274
1275         if (msg->msg_flags & MSG_FASTOPEN) {
1276                 if (sk->sk_state == SMC_INIT) {
1277                         smc->use_fallback = true;
1278                 } else {
1279                         rc = -EINVAL;
1280                         goto out;
1281                 }
1282         }
1283
1284         if (smc->use_fallback)
1285                 rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
1286         else
1287                 rc = smc_tx_sendmsg(smc, msg, len);
1288 out:
1289         release_sock(sk);
1290         return rc;
1291 }
1292
1293 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1294                        int flags)
1295 {
1296         struct sock *sk = sock->sk;
1297         struct smc_sock *smc;
1298         int rc = -ENOTCONN;
1299
1300         smc = smc_sk(sk);
1301         lock_sock(sk);
1302         if ((sk->sk_state == SMC_INIT) ||
1303             (sk->sk_state == SMC_LISTEN) ||
1304             (sk->sk_state == SMC_CLOSED))
1305                 goto out;
1306
1307         if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1308                 rc = 0;
1309                 goto out;
1310         }
1311
1312         if (smc->use_fallback) {
1313                 rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
1314         } else {
1315                 msg->msg_namelen = 0;
1316                 rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
1317         }
1318
1319 out:
1320         release_sock(sk);
1321         return rc;
1322 }
1323
1324 static __poll_t smc_accept_poll(struct sock *parent)
1325 {
1326         struct smc_sock *isk = smc_sk(parent);
1327         __poll_t mask = 0;
1328
1329         spin_lock(&isk->accept_q_lock);
1330         if (!list_empty(&isk->accept_q))
1331                 mask = EPOLLIN | EPOLLRDNORM;
1332         spin_unlock(&isk->accept_q_lock);
1333
1334         return mask;
1335 }
1336
1337 static __poll_t smc_poll(struct file *file, struct socket *sock,
1338                              poll_table *wait)
1339 {
1340         struct sock *sk = sock->sk;
1341         __poll_t mask = 0;
1342         struct smc_sock *smc;
1343
1344         if (!sk)
1345                 return EPOLLNVAL;
1346
1347         smc = smc_sk(sock->sk);
1348         if ((sk->sk_state == SMC_INIT) || smc->use_fallback) {
1349                 /* delegate to CLC child sock */
1350                 mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
1351                 sk->sk_err = smc->clcsock->sk->sk_err;
1352                 if (sk->sk_err)
1353                         mask |= EPOLLERR;
1354         } else {
1355                 if (sk->sk_state != SMC_CLOSED)
1356                         sock_poll_wait(file, sk_sleep(sk), wait);
1357                 if (sk->sk_err)
1358                         mask |= EPOLLERR;
1359                 if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1360                     (sk->sk_state == SMC_CLOSED))
1361                         mask |= EPOLLHUP;
1362                 if (sk->sk_state == SMC_LISTEN) {
1363                         /* woken up by sk_data_ready in smc_listen_work() */
1364                         mask = smc_accept_poll(sk);
1365                 } else {
1366                         if (atomic_read(&smc->conn.sndbuf_space) ||
1367                             sk->sk_shutdown & SEND_SHUTDOWN) {
1368                                 mask |= EPOLLOUT | EPOLLWRNORM;
1369                         } else {
1370                                 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1371                                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1372                         }
1373                         if (atomic_read(&smc->conn.bytes_to_rcv))
1374                                 mask |= EPOLLIN | EPOLLRDNORM;
1375                         if (sk->sk_shutdown & RCV_SHUTDOWN)
1376                                 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
1377                         if (sk->sk_state == SMC_APPCLOSEWAIT1)
1378                                 mask |= EPOLLIN;
1379                 }
1380                 if (smc->conn.urg_state == SMC_URG_VALID)
1381                         mask |= EPOLLPRI;
1382         }
1383
1384         return mask;
1385 }
1386
1387 static int smc_shutdown(struct socket *sock, int how)
1388 {
1389         struct sock *sk = sock->sk;
1390         struct smc_sock *smc;
1391         int rc = -EINVAL;
1392         int rc1 = 0;
1393
1394         smc = smc_sk(sk);
1395
1396         if ((how < SHUT_RD) || (how > SHUT_RDWR))
1397                 return rc;
1398
1399         lock_sock(sk);
1400
1401         rc = -ENOTCONN;
1402         if ((sk->sk_state != SMC_ACTIVE) &&
1403             (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
1404             (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
1405             (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1406             (sk->sk_state != SMC_APPCLOSEWAIT2) &&
1407             (sk->sk_state != SMC_APPFINCLOSEWAIT))
1408                 goto out;
1409         if (smc->use_fallback) {
1410                 rc = kernel_sock_shutdown(smc->clcsock, how);
1411                 sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
1412                 if (sk->sk_shutdown == SHUTDOWN_MASK)
1413                         sk->sk_state = SMC_CLOSED;
1414                 goto out;
1415         }
1416         switch (how) {
1417         case SHUT_RDWR:         /* shutdown in both directions */
1418                 rc = smc_close_active(smc);
1419                 break;
1420         case SHUT_WR:
1421                 rc = smc_close_shutdown_write(smc);
1422                 break;
1423         case SHUT_RD:
1424                 rc = 0;
1425                 /* nothing more to do because peer is not involved */
1426                 break;
1427         }
1428         if (smc->clcsock)
1429                 rc1 = kernel_sock_shutdown(smc->clcsock, how);
1430         /* map sock_shutdown_cmd constants to sk_shutdown value range */
1431         sk->sk_shutdown |= how + 1;
1432
1433 out:
1434         release_sock(sk);
1435         return rc ? rc : rc1;
1436 }
1437
1438 static int smc_setsockopt(struct socket *sock, int level, int optname,
1439                           char __user *optval, unsigned int optlen)
1440 {
1441         struct sock *sk = sock->sk;
1442         struct smc_sock *smc;
1443         int val, rc;
1444
1445         smc = smc_sk(sk);
1446
1447         /* generic setsockopts reaching us here always apply to the
1448          * CLC socket
1449          */
1450         rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
1451                                            optval, optlen);
1452         if (smc->clcsock->sk->sk_err) {
1453                 sk->sk_err = smc->clcsock->sk->sk_err;
1454                 sk->sk_error_report(sk);
1455         }
1456         if (rc)
1457                 return rc;
1458
1459         if (optlen < sizeof(int))
1460                 return -EINVAL;
1461         if (get_user(val, (int __user *)optval))
1462                 return -EFAULT;
1463
1464         lock_sock(sk);
1465         switch (optname) {
1466         case TCP_ULP:
1467         case TCP_FASTOPEN:
1468         case TCP_FASTOPEN_CONNECT:
1469         case TCP_FASTOPEN_KEY:
1470         case TCP_FASTOPEN_NO_COOKIE:
1471                 /* option not supported by SMC */
1472                 if (sk->sk_state == SMC_INIT) {
1473                         smc->use_fallback = true;
1474                 } else {
1475                         if (!smc->use_fallback)
1476                                 rc = -EINVAL;
1477                 }
1478                 break;
1479         case TCP_NODELAY:
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_CORK:
1487                 if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1488                         if (!val && !smc->use_fallback)
1489                                 mod_delayed_work(system_wq, &smc->conn.tx_work,
1490                                                  0);
1491                 }
1492                 break;
1493         case TCP_DEFER_ACCEPT:
1494                 smc->sockopt_defer_accept = val;
1495                 break;
1496         default:
1497                 break;
1498         }
1499         release_sock(sk);
1500
1501         return rc;
1502 }
1503
1504 static int smc_getsockopt(struct socket *sock, int level, int optname,
1505                           char __user *optval, int __user *optlen)
1506 {
1507         struct smc_sock *smc;
1508
1509         smc = smc_sk(sock->sk);
1510         /* socket options apply to the CLC socket */
1511         return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
1512                                              optval, optlen);
1513 }
1514
1515 static int smc_ioctl(struct socket *sock, unsigned int cmd,
1516                      unsigned long arg)
1517 {
1518         union smc_host_cursor cons, urg;
1519         struct smc_connection *conn;
1520         struct smc_sock *smc;
1521         int answ;
1522
1523         smc = smc_sk(sock->sk);
1524         conn = &smc->conn;
1525         lock_sock(&smc->sk);
1526         if (smc->use_fallback) {
1527                 if (!smc->clcsock) {
1528                         release_sock(&smc->sk);
1529                         return -EBADF;
1530                 }
1531                 answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
1532                 release_sock(&smc->sk);
1533                 return answ;
1534         }
1535         switch (cmd) {
1536         case SIOCINQ: /* same as FIONREAD */
1537                 if (smc->sk.sk_state == SMC_LISTEN) {
1538                         release_sock(&smc->sk);
1539                         return -EINVAL;
1540                 }
1541                 if (smc->sk.sk_state == SMC_INIT ||
1542                     smc->sk.sk_state == SMC_CLOSED)
1543                         answ = 0;
1544                 else
1545                         answ = atomic_read(&smc->conn.bytes_to_rcv);
1546                 break;
1547         case SIOCOUTQ:
1548                 /* output queue size (not send + not acked) */
1549                 if (smc->sk.sk_state == SMC_LISTEN) {
1550                         release_sock(&smc->sk);
1551                         return -EINVAL;
1552                 }
1553                 if (smc->sk.sk_state == SMC_INIT ||
1554                     smc->sk.sk_state == SMC_CLOSED)
1555                         answ = 0;
1556                 else
1557                         answ = smc->conn.sndbuf_desc->len -
1558                                         atomic_read(&smc->conn.sndbuf_space);
1559                 break;
1560         case SIOCOUTQNSD:
1561                 /* output queue size (not send only) */
1562                 if (smc->sk.sk_state == SMC_LISTEN) {
1563                         release_sock(&smc->sk);
1564                         return -EINVAL;
1565                 }
1566                 if (smc->sk.sk_state == SMC_INIT ||
1567                     smc->sk.sk_state == SMC_CLOSED)
1568                         answ = 0;
1569                 else
1570                         answ = smc_tx_prepared_sends(&smc->conn);
1571                 break;
1572         case SIOCATMARK:
1573                 if (smc->sk.sk_state == SMC_LISTEN) {
1574                         release_sock(&smc->sk);
1575                         return -EINVAL;
1576                 }
1577                 if (smc->sk.sk_state == SMC_INIT ||
1578                     smc->sk.sk_state == SMC_CLOSED) {
1579                         answ = 0;
1580                 } else {
1581                         smc_curs_write(&cons,
1582                                smc_curs_read(&conn->local_tx_ctrl.cons, conn),
1583                                        conn);
1584                         smc_curs_write(&urg,
1585                                        smc_curs_read(&conn->urg_curs, conn),
1586                                        conn);
1587                         answ = smc_curs_diff(conn->rmb_desc->len,
1588                                              &cons, &urg) == 1;
1589                 }
1590                 break;
1591         default:
1592                 release_sock(&smc->sk);
1593                 return -ENOIOCTLCMD;
1594         }
1595         release_sock(&smc->sk);
1596
1597         return put_user(answ, (int __user *)arg);
1598 }
1599
1600 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
1601                             int offset, size_t size, int flags)
1602 {
1603         struct sock *sk = sock->sk;
1604         struct smc_sock *smc;
1605         int rc = -EPIPE;
1606
1607         smc = smc_sk(sk);
1608         lock_sock(sk);
1609         if (sk->sk_state != SMC_ACTIVE) {
1610                 release_sock(sk);
1611                 goto out;
1612         }
1613         release_sock(sk);
1614         if (smc->use_fallback)
1615                 rc = kernel_sendpage(smc->clcsock, page, offset,
1616                                      size, flags);
1617         else
1618                 rc = sock_no_sendpage(sock, page, offset, size, flags);
1619
1620 out:
1621         return rc;
1622 }
1623
1624 /* Map the affected portions of the rmbe into an spd, note the number of bytes
1625  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
1626  * updates till whenever a respective page has been fully processed.
1627  * Note that subsequent recv() calls have to wait till all splice() processing
1628  * completed.
1629  */
1630 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
1631                                struct pipe_inode_info *pipe, size_t len,
1632                                unsigned int flags)
1633 {
1634         struct sock *sk = sock->sk;
1635         struct smc_sock *smc;
1636         int rc = -ENOTCONN;
1637
1638         smc = smc_sk(sk);
1639         lock_sock(sk);
1640
1641         if (sk->sk_state == SMC_INIT ||
1642             sk->sk_state == SMC_LISTEN ||
1643             sk->sk_state == SMC_CLOSED)
1644                 goto out;
1645
1646         if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1647                 rc = 0;
1648                 goto out;
1649         }
1650
1651         if (smc->use_fallback) {
1652                 rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
1653                                                     pipe, len, flags);
1654         } else {
1655                 if (*ppos) {
1656                         rc = -ESPIPE;
1657                         goto out;
1658                 }
1659                 if (flags & SPLICE_F_NONBLOCK)
1660                         flags = MSG_DONTWAIT;
1661                 else
1662                         flags = 0;
1663                 rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
1664         }
1665 out:
1666         release_sock(sk);
1667
1668         return rc;
1669 }
1670
1671 /* must look like tcp */
1672 static const struct proto_ops smc_sock_ops = {
1673         .family         = PF_SMC,
1674         .owner          = THIS_MODULE,
1675         .release        = smc_release,
1676         .bind           = smc_bind,
1677         .connect        = smc_connect,
1678         .socketpair     = sock_no_socketpair,
1679         .accept         = smc_accept,
1680         .getname        = smc_getname,
1681         .poll           = smc_poll,
1682         .ioctl          = smc_ioctl,
1683         .listen         = smc_listen,
1684         .shutdown       = smc_shutdown,
1685         .setsockopt     = smc_setsockopt,
1686         .getsockopt     = smc_getsockopt,
1687         .sendmsg        = smc_sendmsg,
1688         .recvmsg        = smc_recvmsg,
1689         .mmap           = sock_no_mmap,
1690         .sendpage       = smc_sendpage,
1691         .splice_read    = smc_splice_read,
1692 };
1693
1694 static int smc_create(struct net *net, struct socket *sock, int protocol,
1695                       int kern)
1696 {
1697         int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
1698         struct smc_sock *smc;
1699         struct sock *sk;
1700         int rc;
1701
1702         rc = -ESOCKTNOSUPPORT;
1703         if (sock->type != SOCK_STREAM)
1704                 goto out;
1705
1706         rc = -EPROTONOSUPPORT;
1707         if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
1708                 goto out;
1709
1710         rc = -ENOBUFS;
1711         sock->ops = &smc_sock_ops;
1712         sk = smc_sock_alloc(net, sock, protocol);
1713         if (!sk)
1714                 goto out;
1715
1716         /* create internal TCP socket for CLC handshake and fallback */
1717         smc = smc_sk(sk);
1718         smc->use_fallback = false; /* assume rdma capability first */
1719         rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
1720                               &smc->clcsock);
1721         if (rc) {
1722                 sk_common_release(sk);
1723                 goto out;
1724         }
1725         smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
1726         smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
1727
1728 out:
1729         return rc;
1730 }
1731
1732 static const struct net_proto_family smc_sock_family_ops = {
1733         .family = PF_SMC,
1734         .owner  = THIS_MODULE,
1735         .create = smc_create,
1736 };
1737
1738 static int __init smc_init(void)
1739 {
1740         int rc;
1741
1742         rc = smc_pnet_init();
1743         if (rc)
1744                 return rc;
1745
1746         rc = smc_llc_init();
1747         if (rc) {
1748                 pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
1749                 goto out_pnet;
1750         }
1751
1752         rc = smc_cdc_init();
1753         if (rc) {
1754                 pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
1755                 goto out_pnet;
1756         }
1757
1758         rc = proto_register(&smc_proto, 1);
1759         if (rc) {
1760                 pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
1761                 goto out_pnet;
1762         }
1763
1764         rc = proto_register(&smc_proto6, 1);
1765         if (rc) {
1766                 pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
1767                 goto out_proto;
1768         }
1769
1770         rc = sock_register(&smc_sock_family_ops);
1771         if (rc) {
1772                 pr_err("%s: sock_register fails with %d\n", __func__, rc);
1773                 goto out_proto6;
1774         }
1775         INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
1776         INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
1777
1778         rc = smc_ib_register_client();
1779         if (rc) {
1780                 pr_err("%s: ib_register fails with %d\n", __func__, rc);
1781                 goto out_sock;
1782         }
1783
1784         static_branch_enable(&tcp_have_smc);
1785         return 0;
1786
1787 out_sock:
1788         sock_unregister(PF_SMC);
1789 out_proto6:
1790         proto_unregister(&smc_proto6);
1791 out_proto:
1792         proto_unregister(&smc_proto);
1793 out_pnet:
1794         smc_pnet_exit();
1795         return rc;
1796 }
1797
1798 static void __exit smc_exit(void)
1799 {
1800         smc_core_exit();
1801         static_branch_disable(&tcp_have_smc);
1802         smc_ib_unregister_client();
1803         sock_unregister(PF_SMC);
1804         proto_unregister(&smc_proto6);
1805         proto_unregister(&smc_proto);
1806         smc_pnet_exit();
1807 }
1808
1809 module_init(smc_init);
1810 module_exit(smc_exit);
1811
1812 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
1813 MODULE_DESCRIPTION("smc socket address family");
1814 MODULE_LICENSE("GPL");
1815 MODULE_ALIAS_NETPROTO(PF_SMC);