net/smc/af_smc.c

   1 /*
   2  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
   3  *
   4  *  AF_SMC protocol family socket handler keeping the AF_INET sock address type
   5  *  applies to SOCK_STREAM sockets only
   6  *  offers an alternative communication option for TCP-protocol sockets
   7  *  applicable with RoCE-cards only
   8  *
   9  *  Initial restrictions:
  10  *    - non-blocking connect postponed
  11  *    - IPv6 support postponed
  12  *    - support for alternate links postponed
  13  *    - partial support for non-blocking sockets only
  14  *    - support for urgent data postponed
  15  *
  16  *  Copyright IBM Corp. 2016
  17  *
  18  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
  19  *              based on prototype from Frank Blaschka
  20  */
  21
  22 #define KMSG_COMPONENT "smc"
  23 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  24
  25 #include <linux/module.h>
  26 #include <linux/socket.h>
  27 #include <linux/inetdevice.h>
  28 #include <linux/workqueue.h>
  29 #include <linux/in.h>
  30 #include <net/sock.h>
  31 #include <net/tcp.h>
  32
  33 #include "smc.h"
  34 #include "smc_clc.h"
  35 #include "smc_llc.h"
  36 #include "smc_cdc.h"
  37 #include "smc_core.h"
  38 #include "smc_ib.h"
  39 #include "smc_pnet.h"
  40 #include "smc_tx.h"
  41 #include "smc_rx.h"
  42
  43 static DEFINE_MUTEX(smc_create_lgr_pending);    /* serialize link group
  44                                                  * creation
  45                                                  */
  46
  47 struct smc_lgr_list smc_lgr_list = {            /* established link groups */
  48         .lock = __SPIN_LOCK_UNLOCKED(smc_lgr_list.lock),
  49         .list = LIST_HEAD_INIT(smc_lgr_list.list),
  50 };
  51
  52 static void smc_tcp_listen_work(struct work_struct *);
  53
  54 static void smc_set_keepalive(struct sock *sk, int val)
  55 {
  56         struct smc_sock *smc = smc_sk(sk);
  57
  58         smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
  59 }
  60
  61 static struct proto smc_proto = {
  62         .name           = "SMC",
  63         .owner          = THIS_MODULE,
  64         .keepalive      = smc_set_keepalive,
  65         .obj_size       = sizeof(struct smc_sock),
  66         .slab_flags     = SLAB_DESTROY_BY_RCU,
  67 };
  68
  69 static int smc_release(struct socket *sock)
  70 {
  71         struct sock *sk = sock->sk;
  72         struct smc_sock *smc;
  73
  74         if (!sk)
  75                 goto out;
  76
  77         smc = smc_sk(sk);
  78         lock_sock(sk);
  79
  80         sk->sk_state = SMC_CLOSED;
  81         if (smc->clcsock) {
  82                 sock_release(smc->clcsock);
  83                 smc->clcsock = NULL;
  84         }
  85
  86         /* detach socket */
  87         sock_orphan(sk);
  88         sock->sk = NULL;
  89         release_sock(sk);
  90
  91         sock_put(sk);
  92 out:
  93         return 0;
  94 }
  95
  96 static void smc_destruct(struct sock *sk)
  97 {
  98         if (sk->sk_state != SMC_CLOSED)
  99                 return;
 100         if (!sock_flag(sk, SOCK_DEAD))
 101                 return;
 102
 103         sk_refcnt_debug_dec(sk);
 104 }
 105
 106 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock)
 107 {
 108         struct smc_sock *smc;
 109         struct sock *sk;
 110
 111         sk = sk_alloc(net, PF_SMC, GFP_KERNEL, &smc_proto, 0);
 112         if (!sk)
 113                 return NULL;
 114
 115         sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
 116         sk->sk_state = SMC_INIT;
 117         sk->sk_destruct = smc_destruct;
 118         sk->sk_protocol = SMCPROTO_SMC;
 119         smc = smc_sk(sk);
 120         INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
 121         INIT_LIST_HEAD(&smc->accept_q);
 122         spin_lock_init(&smc->accept_q_lock);
 123         sk_refcnt_debug_inc(sk);
 124
 125         return sk;
 126 }
 127
 128 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
 129                     int addr_len)
 130 {
 131         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
 132         struct sock *sk = sock->sk;
 133         struct smc_sock *smc;
 134         int rc;
 135
 136         smc = smc_sk(sk);
 137
 138         /* replicate tests from inet_bind(), to be safe wrt. future changes */
 139         rc = -EINVAL;
 140         if (addr_len < sizeof(struct sockaddr_in))
 141                 goto out;
 142
 143         rc = -EAFNOSUPPORT;
 144         /* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
 145         if ((addr->sin_family != AF_INET) &&
 146             ((addr->sin_family != AF_UNSPEC) ||
 147              (addr->sin_addr.s_addr != htonl(INADDR_ANY))))
 148                 goto out;
 149
 150         lock_sock(sk);
 151
 152         /* Check if socket is already active */
 153         rc = -EINVAL;
 154         if (sk->sk_state != SMC_INIT)
 155                 goto out_rel;
 156
 157         smc->clcsock->sk->sk_reuse = sk->sk_reuse;
 158         rc = kernel_bind(smc->clcsock, uaddr, addr_len);
 159
 160 out_rel:
 161         release_sock(sk);
 162 out:
 163         return rc;
 164 }
 165
 166 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
 167                                    unsigned long mask)
 168 {
 169         /* options we don't get control via setsockopt for */
 170         nsk->sk_type = osk->sk_type;
 171         nsk->sk_sndbuf = osk->sk_sndbuf;
 172         nsk->sk_rcvbuf = osk->sk_rcvbuf;
 173         nsk->sk_sndtimeo = osk->sk_sndtimeo;
 174         nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
 175         nsk->sk_mark = osk->sk_mark;
 176         nsk->sk_priority = osk->sk_priority;
 177         nsk->sk_rcvlowat = osk->sk_rcvlowat;
 178         nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
 179         nsk->sk_err = osk->sk_err;
 180
 181         nsk->sk_flags &= ~mask;
 182         nsk->sk_flags |= osk->sk_flags & mask;
 183 }
 184
 185 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
 186                              (1UL << SOCK_KEEPOPEN) | \
 187                              (1UL << SOCK_LINGER) | \
 188                              (1UL << SOCK_BROADCAST) | \
 189                              (1UL << SOCK_TIMESTAMP) | \
 190                              (1UL << SOCK_DBG) | \
 191                              (1UL << SOCK_RCVTSTAMP) | \
 192                              (1UL << SOCK_RCVTSTAMPNS) | \
 193                              (1UL << SOCK_LOCALROUTE) | \
 194                              (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
 195                              (1UL << SOCK_RXQ_OVFL) | \
 196                              (1UL << SOCK_WIFI_STATUS) | \
 197                              (1UL << SOCK_NOFCS) | \
 198                              (1UL << SOCK_FILTER_LOCKED))
 199 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
 200  * clc socket (since smc is not called for these options from net/core)
 201  */
 202 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
 203 {
 204         smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
 205 }
 206
 207 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
 208                              (1UL << SOCK_KEEPOPEN) | \
 209                              (1UL << SOCK_LINGER) | \
 210                              (1UL << SOCK_DBG))
 211 /* copy only settings and flags relevant for smc from clc to smc socket */
 212 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
 213 {
 214         smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
 215 }
 216
 217 /* determine subnet and mask of internal TCP socket */
 218 int smc_netinfo_by_tcpsk(struct socket *clcsock,
 219                          __be32 *subnet, u8 *prefix_len)
 220 {
 221         struct dst_entry *dst = sk_dst_get(clcsock->sk);
 222         struct sockaddr_in addr;
 223         int rc = -ENOENT;
 224         int len;
 225
 226         if (!dst) {
 227                 rc = -ENOTCONN;
 228                 goto out;
 229         }
 230         if (!dst->dev) {
 231                 rc = -ENODEV;
 232                 goto out_rel;
 233         }
 234
 235         /* get address to which the internal TCP socket is bound */
 236         kernel_getsockname(clcsock, (struct sockaddr *)&addr, &len);
 237         /* analyze IPv4 specific data of net_device belonging to TCP socket */
 238         for_ifa(dst->dev->ip_ptr) {
 239                 if (ifa->ifa_address != addr.sin_addr.s_addr)
 240                         continue;
 241                 *prefix_len = inet_mask_len(ifa->ifa_mask);
 242                 *subnet = ifa->ifa_address & ifa->ifa_mask;
 243                 rc = 0;
 244                 break;
 245         } endfor_ifa(dst->dev->ip_ptr);
 246
 247 out_rel:
 248         dst_release(dst);
 249 out:
 250         return rc;
 251 }
 252
 253 static int smc_clnt_conf_first_link(struct smc_sock *smc, union ib_gid *gid)
 254 {
 255         struct smc_link_group *lgr = smc->conn.lgr;
 256         struct smc_link *link;
 257         int rest;
 258         int rc;
 259
 260         link = &lgr->lnk[SMC_SINGLE_LINK];
 261         /* receive CONFIRM LINK request from server over RoCE fabric */
 262         rest = wait_for_completion_interruptible_timeout(
 263                 &link->llc_confirm,
 264                 SMC_LLC_WAIT_FIRST_TIME);
 265         if (rest <= 0) {
 266                 struct smc_clc_msg_decline dclc;
 267
 268                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
 269                                       SMC_CLC_DECLINE);
 270                 return rc;
 271         }
 272
 273         rc = smc_ib_modify_qp_rts(link);
 274         if (rc)
 275                 return SMC_CLC_DECL_INTERR;
 276
 277         smc_wr_remember_qp_attr(link);
 278         /* send CONFIRM LINK response over RoCE fabric */
 279         rc = smc_llc_send_confirm_link(link,
 280                                        link->smcibdev->mac[link->ibport - 1],
 281                                        gid, SMC_LLC_RESP);
 282         if (rc < 0)
 283                 return SMC_CLC_DECL_TCL;
 284
 285         return rc;
 286 }
 287
 288 static void smc_conn_save_peer_info(struct smc_sock *smc,
 289                                     struct smc_clc_msg_accept_confirm *clc)
 290 {
 291         smc->conn.peer_conn_idx = clc->conn_idx;
 292         smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
 293         smc->conn.peer_rmbe_size = smc_uncompress_bufsize(clc->rmbe_size);
 294         atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
 295 }
 296
 297 static void smc_link_save_peer_info(struct smc_link *link,
 298                                     struct smc_clc_msg_accept_confirm *clc)
 299 {
 300         link->peer_qpn = ntoh24(clc->qpn);
 301         memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
 302         memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
 303         link->peer_psn = ntoh24(clc->psn);
 304         link->peer_mtu = clc->qp_mtu;
 305 }
 306
 307 /* setup for RDMA connection of client */
 308 static int smc_connect_rdma(struct smc_sock *smc)
 309 {
 310         struct sockaddr_in *inaddr = (struct sockaddr_in *)smc->addr;
 311         struct smc_clc_msg_accept_confirm aclc;
 312         int local_contact = SMC_FIRST_CONTACT;
 313         struct smc_ib_device *smcibdev;
 314         struct smc_link *link;
 315         u8 srv_first_contact;
 316         int reason_code = 0;
 317         int rc = 0;
 318         u8 ibport;
 319
 320         /* IPSec connections opt out of SMC-R optimizations */
 321         if (using_ipsec(smc)) {
 322                 reason_code = SMC_CLC_DECL_IPSEC;
 323                 goto decline_rdma;
 324         }
 325
 326         /* PNET table look up: search active ib_device and port
 327          * within same PNETID that also contains the ethernet device
 328          * used for the internal TCP socket
 329          */
 330         smc_pnet_find_roce_resource(smc->clcsock->sk, &smcibdev, &ibport);
 331         if (!smcibdev) {
 332                 reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
 333                 goto decline_rdma;
 334         }
 335
 336         /* do inband token exchange */
 337         reason_code = smc_clc_send_proposal(smc, smcibdev, ibport);
 338         if (reason_code < 0) {
 339                 rc = reason_code;
 340                 goto out_err;
 341         }
 342         if (reason_code > 0) /* configuration error */
 343                 goto decline_rdma;
 344         /* receive SMC Accept CLC message */
 345         reason_code = smc_clc_wait_msg(smc, &aclc, sizeof(aclc),
 346                                        SMC_CLC_ACCEPT);
 347         if (reason_code < 0) {
 348                 rc = reason_code;
 349                 goto out_err;
 350         }
 351         if (reason_code > 0)
 352                 goto decline_rdma;
 353
 354         srv_first_contact = aclc.hdr.flag;
 355         mutex_lock(&smc_create_lgr_pending);
 356         local_contact = smc_conn_create(smc, inaddr->sin_addr.s_addr, smcibdev,
 357                                         ibport, &aclc.lcl, srv_first_contact);
 358         if (local_contact < 0) {
 359                 rc = local_contact;
 360                 if (rc == -ENOMEM)
 361                         reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
 362                 else if (rc == -ENOLINK)
 363                         reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
 364                 goto decline_rdma_unlock;
 365         }
 366         link = &smc->conn.lgr->lnk[SMC_SINGLE_LINK];
 367
 368         smc_conn_save_peer_info(smc, &aclc);
 369
 370         rc = smc_sndbuf_create(smc);
 371         if (rc) {
 372                 reason_code = SMC_CLC_DECL_MEM;
 373                 goto decline_rdma_unlock;
 374         }
 375         rc = smc_rmb_create(smc);
 376         if (rc) {
 377                 reason_code = SMC_CLC_DECL_MEM;
 378                 goto decline_rdma_unlock;
 379         }
 380
 381         if (local_contact == SMC_FIRST_CONTACT)
 382                 smc_link_save_peer_info(link, &aclc);
 383
 384         rc = smc_rmb_rtoken_handling(&smc->conn, &aclc);
 385         if (rc) {
 386                 reason_code = SMC_CLC_DECL_INTERR;
 387                 goto decline_rdma_unlock;
 388         }
 389
 390         if (local_contact == SMC_FIRST_CONTACT) {
 391                 rc = smc_ib_ready_link(link);
 392                 if (rc) {
 393                         reason_code = SMC_CLC_DECL_INTERR;
 394                         goto decline_rdma_unlock;
 395                 }
 396         }
 397
 398         rc = smc_clc_send_confirm(smc);
 399         if (rc)
 400                 goto out_err_unlock;
 401
 402         if (local_contact == SMC_FIRST_CONTACT) {
 403                 /* QP confirmation over RoCE fabric */
 404                 reason_code = smc_clnt_conf_first_link(
 405                         smc, &smcibdev->gid[ibport - 1]);
 406                 if (reason_code < 0) {
 407                         rc = reason_code;
 408                         goto out_err_unlock;
 409                 }
 410                 if (reason_code > 0)
 411                         goto decline_rdma_unlock;
 412         }
 413
 414         mutex_unlock(&smc_create_lgr_pending);
 415         smc_tx_init(smc);
 416         smc_rx_init(smc);
 417
 418 out_connected:
 419         smc_copy_sock_settings_to_clc(smc);
 420         smc->sk.sk_state = SMC_ACTIVE;
 421
 422         return rc ? rc : local_contact;
 423
 424 decline_rdma_unlock:
 425         mutex_unlock(&smc_create_lgr_pending);
 426         smc_conn_free(&smc->conn);
 427 decline_rdma:
 428         /* RDMA setup failed, switch back to TCP */
 429         smc->use_fallback = true;
 430         if (reason_code && (reason_code != SMC_CLC_DECL_REPLY)) {
 431                 rc = smc_clc_send_decline(smc, reason_code, 0);
 432                 if (rc < sizeof(struct smc_clc_msg_decline))
 433                         goto out_err;
 434         }
 435         goto out_connected;
 436
 437 out_err_unlock:
 438         mutex_unlock(&smc_create_lgr_pending);
 439         smc_conn_free(&smc->conn);
 440 out_err:
 441         return rc;
 442 }
 443
 444 static int smc_connect(struct socket *sock, struct sockaddr *addr,
 445                        int alen, int flags)
 446 {
 447         struct sock *sk = sock->sk;
 448         struct smc_sock *smc;
 449         int rc = -EINVAL;
 450
 451         smc = smc_sk(sk);
 452
 453         /* separate smc parameter checking to be safe */
 454         if (alen < sizeof(addr->sa_family))
 455                 goto out_err;
 456         if (addr->sa_family != AF_INET)
 457                 goto out_err;
 458         smc->addr = addr;       /* needed for nonblocking connect */
 459
 460         lock_sock(sk);
 461         switch (sk->sk_state) {
 462         default:
 463                 goto out;
 464         case SMC_ACTIVE:
 465                 rc = -EISCONN;
 466                 goto out;
 467         case SMC_INIT:
 468                 rc = 0;
 469                 break;
 470         }
 471
 472         smc_copy_sock_settings_to_clc(smc);
 473         rc = kernel_connect(smc->clcsock, addr, alen, flags);
 474         if (rc)
 475                 goto out;
 476
 477         /* setup RDMA connection */
 478         rc = smc_connect_rdma(smc);
 479         if (rc < 0)
 480                 goto out;
 481         else
 482                 rc = 0; /* success cases including fallback */
 483
 484 out:
 485         release_sock(sk);
 486 out_err:
 487         return rc;
 488 }
 489
 490 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
 491 {
 492         struct sock *sk = &lsmc->sk;
 493         struct socket *new_clcsock;
 494         struct sock *new_sk;
 495         int rc;
 496
 497         release_sock(&lsmc->sk);
 498         new_sk = smc_sock_alloc(sock_net(sk), NULL);
 499         if (!new_sk) {
 500                 rc = -ENOMEM;
 501                 lsmc->sk.sk_err = ENOMEM;
 502                 *new_smc = NULL;
 503                 lock_sock(&lsmc->sk);
 504                 goto out;
 505         }
 506         *new_smc = smc_sk(new_sk);
 507
 508         rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
 509         lock_sock(&lsmc->sk);
 510         if  (rc < 0) {
 511                 lsmc->sk.sk_err = -rc;
 512                 new_sk->sk_state = SMC_CLOSED;
 513                 sock_set_flag(new_sk, SOCK_DEAD);
 514                 sock_put(new_sk);
 515                 *new_smc = NULL;
 516                 goto out;
 517         }
 518         if (lsmc->sk.sk_state == SMC_CLOSED) {
 519                 if (new_clcsock)
 520                         sock_release(new_clcsock);
 521                 new_sk->sk_state = SMC_CLOSED;
 522                 sock_set_flag(new_sk, SOCK_DEAD);
 523                 sock_put(new_sk);
 524                 *new_smc = NULL;
 525                 goto out;
 526         }
 527
 528         (*new_smc)->clcsock = new_clcsock;
 529 out:
 530         return rc;
 531 }
 532
 533 /* add a just created sock to the accept queue of the listen sock as
 534  * candidate for a following socket accept call from user space
 535  */
 536 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
 537 {
 538         struct smc_sock *par = smc_sk(parent);
 539
 540         sock_hold(sk);
 541         spin_lock(&par->accept_q_lock);
 542         list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
 543         spin_unlock(&par->accept_q_lock);
 544         sk_acceptq_added(parent);
 545 }
 546
 547 /* remove a socket from the accept queue of its parental listening socket */
 548 static void smc_accept_unlink(struct sock *sk)
 549 {
 550         struct smc_sock *par = smc_sk(sk)->listen_smc;
 551
 552         spin_lock(&par->accept_q_lock);
 553         list_del_init(&smc_sk(sk)->accept_q);
 554         spin_unlock(&par->accept_q_lock);
 555         sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
 556         sock_put(sk);
 557 }
 558
 559 /* remove a sock from the accept queue to bind it to a new socket created
 560  * for a socket accept call from user space
 561  */
 562 static struct sock *smc_accept_dequeue(struct sock *parent,
 563                                        struct socket *new_sock)
 564 {
 565         struct smc_sock *isk, *n;
 566         struct sock *new_sk;
 567
 568         list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
 569                 new_sk = (struct sock *)isk;
 570
 571                 smc_accept_unlink(new_sk);
 572                 if (new_sk->sk_state == SMC_CLOSED) {
 573                         /* tbd in follow-on patch: close this sock */
 574                         continue;
 575                 }
 576                 if (new_sock)
 577                         sock_graft(new_sk, new_sock);
 578                 return new_sk;
 579         }
 580         return NULL;
 581 }
 582
 583 /* clean up for a created but never accepted sock */
 584 static void smc_close_non_accepted(struct sock *sk)
 585 {
 586         struct smc_sock *smc = smc_sk(sk);
 587
 588         sock_hold(sk);
 589         if (smc->clcsock) {
 590                 struct socket *tcp;
 591
 592                 tcp = smc->clcsock;
 593                 smc->clcsock = NULL;
 594                 sock_release(tcp);
 595         }
 596         /* more closing stuff to be added with socket closing patch */
 597         sock_put(sk);
 598 }
 599
 600 static int smc_serv_conf_first_link(struct smc_sock *smc)
 601 {
 602         struct smc_link_group *lgr = smc->conn.lgr;
 603         struct smc_link *link;
 604         int rest;
 605         int rc;
 606
 607         link = &lgr->lnk[SMC_SINGLE_LINK];
 608         /* send CONFIRM LINK request to client over the RoCE fabric */
 609         rc = smc_llc_send_confirm_link(link,
 610                                        link->smcibdev->mac[link->ibport - 1],
 611                                        &link->smcibdev->gid[link->ibport - 1],
 612                                        SMC_LLC_REQ);
 613         if (rc < 0)
 614                 return SMC_CLC_DECL_TCL;
 615
 616         /* receive CONFIRM LINK response from client over the RoCE fabric */
 617         rest = wait_for_completion_interruptible_timeout(
 618                 &link->llc_confirm_resp,
 619                 SMC_LLC_WAIT_FIRST_TIME);
 620         if (rest <= 0) {
 621                 struct smc_clc_msg_decline dclc;
 622
 623                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
 624                                       SMC_CLC_DECLINE);
 625         }
 626
 627         return rc;
 628 }
 629
 630 /* setup for RDMA connection of server */
 631 static void smc_listen_work(struct work_struct *work)
 632 {
 633         struct smc_sock *new_smc = container_of(work, struct smc_sock,
 634                                                 smc_listen_work);
 635         struct socket *newclcsock = new_smc->clcsock;
 636         struct smc_sock *lsmc = new_smc->listen_smc;
 637         struct smc_clc_msg_accept_confirm cclc;
 638         int local_contact = SMC_REUSE_CONTACT;
 639         struct sock *newsmcsk = &new_smc->sk;
 640         struct smc_clc_msg_proposal pclc;
 641         struct smc_ib_device *smcibdev;
 642         struct sockaddr_in peeraddr;
 643         struct smc_link *link;
 644         int reason_code = 0;
 645         int rc = 0, len;
 646         __be32 subnet;
 647         u8 prefix_len;
 648         u8 ibport;
 649
 650         /* do inband token exchange -
 651          *wait for and receive SMC Proposal CLC message
 652          */
 653         reason_code = smc_clc_wait_msg(new_smc, &pclc, sizeof(pclc),
 654                                        SMC_CLC_PROPOSAL);
 655         if (reason_code < 0)
 656                 goto out_err;
 657         if (reason_code > 0)
 658                 goto decline_rdma;
 659
 660         /* IPSec connections opt out of SMC-R optimizations */
 661         if (using_ipsec(new_smc)) {
 662                 reason_code = SMC_CLC_DECL_IPSEC;
 663                 goto decline_rdma;
 664         }
 665
 666         /* PNET table look up: search active ib_device and port
 667          * within same PNETID that also contains the ethernet device
 668          * used for the internal TCP socket
 669          */
 670         smc_pnet_find_roce_resource(newclcsock->sk, &smcibdev, &ibport);
 671         if (!smcibdev) {
 672                 reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
 673                 goto decline_rdma;
 674         }
 675
 676         /* determine subnet and mask from internal TCP socket */
 677         rc = smc_netinfo_by_tcpsk(newclcsock, &subnet, &prefix_len);
 678         if (rc) {
 679                 reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
 680                 goto decline_rdma;
 681         }
 682         if ((pclc.outgoing_subnet != subnet) ||
 683             (pclc.prefix_len != prefix_len)) {
 684                 reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
 685                 goto decline_rdma;
 686         }
 687
 688         /* get address of the peer connected to the internal TCP socket */
 689         kernel_getpeername(newclcsock, (struct sockaddr *)&peeraddr, &len);
 690
 691         /* allocate connection / link group */
 692         mutex_lock(&smc_create_lgr_pending);
 693         local_contact = smc_conn_create(new_smc, peeraddr.sin_addr.s_addr,
 694                                         smcibdev, ibport, &pclc.lcl, 0);
 695         if (local_contact == SMC_REUSE_CONTACT)
 696                 /* lock no longer needed, free it due to following
 697                  * smc_clc_wait_msg() call
 698                  */
 699                 mutex_unlock(&smc_create_lgr_pending);
 700         if (local_contact < 0) {
 701                 rc = local_contact;
 702                 if (rc == -ENOMEM)
 703                         reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
 704                 else if (rc == -ENOLINK)
 705                         reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
 706                 goto decline_rdma;
 707         }
 708         link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
 709
 710         rc = smc_sndbuf_create(new_smc);
 711         if (rc) {
 712                 reason_code = SMC_CLC_DECL_MEM;
 713                 goto decline_rdma;
 714         }
 715         rc = smc_rmb_create(new_smc);
 716         if (rc) {
 717                 reason_code = SMC_CLC_DECL_MEM;
 718                 goto decline_rdma;
 719         }
 720
 721         rc = smc_clc_send_accept(new_smc, local_contact);
 722         if (rc)
 723                 goto out_err;
 724
 725         /* receive SMC Confirm CLC message */
 726         reason_code = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
 727                                        SMC_CLC_CONFIRM);
 728         if (reason_code < 0)
 729                 goto out_err;
 730         if (reason_code > 0)
 731                 goto decline_rdma;
 732         smc_conn_save_peer_info(new_smc, &cclc);
 733         if (local_contact == SMC_FIRST_CONTACT)
 734                 smc_link_save_peer_info(link, &cclc);
 735
 736         rc = smc_rmb_rtoken_handling(&new_smc->conn, &cclc);
 737         if (rc) {
 738                 reason_code = SMC_CLC_DECL_INTERR;
 739                 goto decline_rdma;
 740         }
 741
 742         if (local_contact == SMC_FIRST_CONTACT) {
 743                 rc = smc_ib_ready_link(link);
 744                 if (rc) {
 745                         reason_code = SMC_CLC_DECL_INTERR;
 746                         goto decline_rdma;
 747                 }
 748                 /* QP confirmation over RoCE fabric */
 749                 reason_code = smc_serv_conf_first_link(new_smc);
 750                 if (reason_code < 0) {
 751                         /* peer is not aware of a problem */
 752                         rc = reason_code;
 753                         goto out_err;
 754                 }
 755                 if (reason_code > 0)
 756                         goto decline_rdma;
 757         }
 758
 759         smc_tx_init(new_smc);
 760         smc_rx_init(new_smc);
 761
 762 out_connected:
 763         sk_refcnt_debug_inc(newsmcsk);
 764         newsmcsk->sk_state = SMC_ACTIVE;
 765 enqueue:
 766         if (local_contact == SMC_FIRST_CONTACT)
 767                 mutex_unlock(&smc_create_lgr_pending);
 768         lock_sock(&lsmc->sk);
 769         if (lsmc->sk.sk_state == SMC_LISTEN) {
 770                 smc_accept_enqueue(&lsmc->sk, newsmcsk);
 771         } else { /* no longer listening */
 772                 smc_close_non_accepted(newsmcsk);
 773         }
 774         release_sock(&lsmc->sk);
 775
 776         /* Wake up accept */
 777         lsmc->sk.sk_data_ready(&lsmc->sk);
 778         sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
 779         return;
 780
 781 decline_rdma:
 782         /* RDMA setup failed, switch back to TCP */
 783         smc_conn_free(&new_smc->conn);
 784         new_smc->use_fallback = true;
 785         if (reason_code && (reason_code != SMC_CLC_DECL_REPLY)) {
 786                 rc = smc_clc_send_decline(new_smc, reason_code, 0);
 787                 if (rc < sizeof(struct smc_clc_msg_decline))
 788                         goto out_err;
 789         }
 790         goto out_connected;
 791
 792 out_err:
 793         newsmcsk->sk_state = SMC_CLOSED;
 794         goto enqueue; /* queue new sock with sk_err set */
 795 }
 796
 797 static void smc_tcp_listen_work(struct work_struct *work)
 798 {
 799         struct smc_sock *lsmc = container_of(work, struct smc_sock,
 800                                              tcp_listen_work);
 801         struct smc_sock *new_smc;
 802         int rc = 0;
 803
 804         lock_sock(&lsmc->sk);
 805         while (lsmc->sk.sk_state == SMC_LISTEN) {
 806                 rc = smc_clcsock_accept(lsmc, &new_smc);
 807                 if (rc)
 808                         goto out;
 809                 if (!new_smc)
 810                         continue;
 811
 812                 new_smc->listen_smc = lsmc;
 813                 new_smc->use_fallback = false; /* assume rdma capability first*/
 814                 sock_hold(&lsmc->sk); /* sock_put in smc_listen_work */
 815                 INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
 816                 smc_copy_sock_settings_to_smc(new_smc);
 817                 schedule_work(&new_smc->smc_listen_work);
 818         }
 819
 820 out:
 821         release_sock(&lsmc->sk);
 822         lsmc->sk.sk_data_ready(&lsmc->sk); /* no more listening, wake accept */
 823 }
 824
 825 static int smc_listen(struct socket *sock, int backlog)
 826 {
 827         struct sock *sk = sock->sk;
 828         struct smc_sock *smc;
 829         int rc;
 830
 831         smc = smc_sk(sk);
 832         lock_sock(sk);
 833
 834         rc = -EINVAL;
 835         if ((sk->sk_state != SMC_INIT) && (sk->sk_state != SMC_LISTEN))
 836                 goto out;
 837
 838         rc = 0;
 839         if (sk->sk_state == SMC_LISTEN) {
 840                 sk->sk_max_ack_backlog = backlog;
 841                 goto out;
 842         }
 843         /* some socket options are handled in core, so we could not apply
 844          * them to the clc socket -- copy smc socket options to clc socket
 845          */
 846         smc_copy_sock_settings_to_clc(smc);
 847
 848         rc = kernel_listen(smc->clcsock, backlog);
 849         if (rc)
 850                 goto out;
 851         sk->sk_max_ack_backlog = backlog;
 852         sk->sk_ack_backlog = 0;
 853         sk->sk_state = SMC_LISTEN;
 854         INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
 855         schedule_work(&smc->tcp_listen_work);
 856
 857 out:
 858         release_sock(sk);
 859         return rc;
 860 }
 861
 862 static int smc_accept(struct socket *sock, struct socket *new_sock,
 863                       int flags)
 864 {
 865         struct sock *sk = sock->sk, *nsk;
 866         DECLARE_WAITQUEUE(wait, current);
 867         struct smc_sock *lsmc;
 868         long timeo;
 869         int rc = 0;
 870
 871         lsmc = smc_sk(sk);
 872         lock_sock(sk);
 873
 874         if (lsmc->sk.sk_state != SMC_LISTEN) {
 875                 rc = -EINVAL;
 876                 goto out;
 877         }
 878
 879         /* Wait for an incoming connection */
 880         timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
 881         add_wait_queue_exclusive(sk_sleep(sk), &wait);
 882         while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
 883                 set_current_state(TASK_INTERRUPTIBLE);
 884                 if (!timeo) {
 885                         rc = -EAGAIN;
 886                         break;
 887                 }
 888                 release_sock(sk);
 889                 timeo = schedule_timeout(timeo);
 890                 /* wakeup by sk_data_ready in smc_listen_work() */
 891                 sched_annotate_sleep();
 892                 lock_sock(sk);
 893                 if (signal_pending(current)) {
 894                         rc = sock_intr_errno(timeo);
 895                         break;
 896                 }
 897         }
 898         set_current_state(TASK_RUNNING);
 899         remove_wait_queue(sk_sleep(sk), &wait);
 900
 901         if (!rc)
 902                 rc = sock_error(nsk);
 903
 904 out:
 905         release_sock(sk);
 906         return rc;
 907 }
 908
 909 static int smc_getname(struct socket *sock, struct sockaddr *addr,
 910                        int *len, int peer)
 911 {
 912         struct smc_sock *smc;
 913
 914         if (peer && (sock->sk->sk_state != SMC_ACTIVE))
 915                 return -ENOTCONN;
 916
 917         smc = smc_sk(sock->sk);
 918
 919         return smc->clcsock->ops->getname(smc->clcsock, addr, len, peer);
 920 }
 921
 922 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
 923 {
 924         struct sock *sk = sock->sk;
 925         struct smc_sock *smc;
 926         int rc = -EPIPE;
 927
 928         smc = smc_sk(sk);
 929         lock_sock(sk);
 930         if (sk->sk_state != SMC_ACTIVE)
 931                 goto out;
 932         if (smc->use_fallback)
 933                 rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
 934         else
 935                 rc = smc_tx_sendmsg(smc, msg, len);
 936 out:
 937         release_sock(sk);
 938         return rc;
 939 }
 940
 941 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
 942                        int flags)
 943 {
 944         struct sock *sk = sock->sk;
 945         struct smc_sock *smc;
 946         int rc = -ENOTCONN;
 947
 948         smc = smc_sk(sk);
 949         lock_sock(sk);
 950         if ((sk->sk_state != SMC_ACTIVE) && (sk->sk_state != SMC_CLOSED))
 951                 goto out;
 952
 953         if (smc->use_fallback)
 954                 rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
 955         else
 956                 rc = smc_rx_recvmsg(smc, msg, len, flags);
 957 out:
 958         release_sock(sk);
 959         return rc;
 960 }
 961
 962 static unsigned int smc_accept_poll(struct sock *parent)
 963 {
 964         struct smc_sock *isk;
 965         struct sock *sk;
 966
 967         lock_sock(parent);
 968         list_for_each_entry(isk, &smc_sk(parent)->accept_q, accept_q) {
 969                 sk = (struct sock *)isk;
 970
 971                 if (sk->sk_state == SMC_ACTIVE) {
 972                         release_sock(parent);
 973                         return POLLIN | POLLRDNORM;
 974                 }
 975         }
 976         release_sock(parent);
 977
 978         return 0;
 979 }
 980
 981 static unsigned int smc_poll(struct file *file, struct socket *sock,
 982                              poll_table *wait)
 983 {
 984         struct sock *sk = sock->sk;
 985         unsigned int mask = 0;
 986         struct smc_sock *smc;
 987         int rc;
 988
 989         smc = smc_sk(sock->sk);
 990         if ((sk->sk_state == SMC_INIT) || smc->use_fallback) {
 991                 /* delegate to CLC child sock */
 992                 mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
 993                 /* if non-blocking connect finished ... */
 994                 lock_sock(sk);
 995                 if ((sk->sk_state == SMC_INIT) && (mask & POLLOUT)) {
 996                         sk->sk_err = smc->clcsock->sk->sk_err;
 997                         if (sk->sk_err) {
 998                                 mask |= POLLERR;
 999                         } else {
1000                                 rc = smc_connect_rdma(smc);
1001                                 if (rc < 0)
1002                                         mask |= POLLERR;
1003                                 else
1004                                         /* success cases including fallback */
1005                                         mask |= POLLOUT | POLLWRNORM;
1006                         }
1007                 }
1008                 release_sock(sk);
1009         } else {
1010                 sock_poll_wait(file, sk_sleep(sk), wait);
1011                 if (sk->sk_state == SMC_LISTEN)
1012                         /* woken up by sk_data_ready in smc_listen_work() */
1013                         mask |= smc_accept_poll(sk);
1014                 if (sk->sk_err)
1015                         mask |= POLLERR;
1016                 if (atomic_read(&smc->conn.sndbuf_space)) {
1017                         mask |= POLLOUT | POLLWRNORM;
1018                 } else {
1019                         sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1020                         set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1021                 }
1022                 if (atomic_read(&smc->conn.bytes_to_rcv))
1023                         mask |= POLLIN | POLLRDNORM;
1024                 /* for now - to be enhanced in follow-on patch */
1025         }
1026
1027         return mask;
1028 }
1029
1030 static int smc_shutdown(struct socket *sock, int how)
1031 {
1032         struct sock *sk = sock->sk;
1033         struct smc_sock *smc;
1034         int rc = -EINVAL;
1035
1036         smc = smc_sk(sk);
1037
1038         if ((how < SHUT_RD) || (how > SHUT_RDWR))
1039                 goto out_err;
1040
1041         lock_sock(sk);
1042
1043         rc = -ENOTCONN;
1044         if (sk->sk_state == SMC_CLOSED)
1045                 goto out;
1046         if (smc->use_fallback) {
1047                 rc = kernel_sock_shutdown(smc->clcsock, how);
1048                 sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
1049                 if (sk->sk_shutdown == SHUTDOWN_MASK)
1050                         sk->sk_state = SMC_CLOSED;
1051         } else {
1052                 rc = sock_no_shutdown(sock, how);
1053         }
1054
1055 out:
1056         release_sock(sk);
1057
1058 out_err:
1059         return rc;
1060 }
1061
1062 static int smc_setsockopt(struct socket *sock, int level, int optname,
1063                           char __user *optval, unsigned int optlen)
1064 {
1065         struct sock *sk = sock->sk;
1066         struct smc_sock *smc;
1067
1068         smc = smc_sk(sk);
1069
1070         /* generic setsockopts reaching us here always apply to the
1071          * CLC socket
1072          */
1073         return smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
1074                                              optval, optlen);
1075 }
1076
1077 static int smc_getsockopt(struct socket *sock, int level, int optname,
1078                           char __user *optval, int __user *optlen)
1079 {
1080         struct smc_sock *smc;
1081
1082         smc = smc_sk(sock->sk);
1083         /* socket options apply to the CLC socket */
1084         return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
1085                                              optval, optlen);
1086 }
1087
1088 static int smc_ioctl(struct socket *sock, unsigned int cmd,
1089                      unsigned long arg)
1090 {
1091         struct smc_sock *smc;
1092
1093         smc = smc_sk(sock->sk);
1094         if (smc->use_fallback)
1095                 return smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
1096         else
1097                 return sock_no_ioctl(sock, cmd, arg);
1098 }
1099
1100 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
1101                             int offset, size_t size, int flags)
1102 {
1103         struct sock *sk = sock->sk;
1104         struct smc_sock *smc;
1105         int rc = -EPIPE;
1106
1107         smc = smc_sk(sk);
1108         lock_sock(sk);
1109         if (sk->sk_state != SMC_ACTIVE)
1110                 goto out;
1111         if (smc->use_fallback)
1112                 rc = kernel_sendpage(smc->clcsock, page, offset,
1113                                      size, flags);
1114         else
1115                 rc = sock_no_sendpage(sock, page, offset, size, flags);
1116
1117 out:
1118         release_sock(sk);
1119         return rc;
1120 }
1121
1122 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
1123                                struct pipe_inode_info *pipe, size_t len,
1124                                     unsigned int flags)
1125 {
1126         struct sock *sk = sock->sk;
1127         struct smc_sock *smc;
1128         int rc = -ENOTCONN;
1129
1130         smc = smc_sk(sk);
1131         lock_sock(sk);
1132         if ((sk->sk_state != SMC_ACTIVE) && (sk->sk_state != SMC_CLOSED))
1133                 goto out;
1134         if (smc->use_fallback) {
1135                 rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
1136                                                     pipe, len, flags);
1137         } else {
1138                 rc = -EOPNOTSUPP;
1139         }
1140 out:
1141         release_sock(sk);
1142         return rc;
1143 }
1144
1145 /* must look like tcp */
1146 static const struct proto_ops smc_sock_ops = {
1147         .family         = PF_SMC,
1148         .owner          = THIS_MODULE,
1149         .release        = smc_release,
1150         .bind           = smc_bind,
1151         .connect        = smc_connect,
1152         .socketpair     = sock_no_socketpair,
1153         .accept         = smc_accept,
1154         .getname        = smc_getname,
1155         .poll           = smc_poll,
1156         .ioctl          = smc_ioctl,
1157         .listen         = smc_listen,
1158         .shutdown       = smc_shutdown,
1159         .setsockopt     = smc_setsockopt,
1160         .getsockopt     = smc_getsockopt,
1161         .sendmsg        = smc_sendmsg,
1162         .recvmsg        = smc_recvmsg,
1163         .mmap           = sock_no_mmap,
1164         .sendpage       = smc_sendpage,
1165         .splice_read    = smc_splice_read,
1166 };
1167
1168 static int smc_create(struct net *net, struct socket *sock, int protocol,
1169                       int kern)
1170 {
1171         struct smc_sock *smc;
1172         struct sock *sk;
1173         int rc;
1174
1175         rc = -ESOCKTNOSUPPORT;
1176         if (sock->type != SOCK_STREAM)
1177                 goto out;
1178
1179         rc = -EPROTONOSUPPORT;
1180         if ((protocol != IPPROTO_IP) && (protocol != IPPROTO_TCP))
1181                 goto out;
1182
1183         rc = -ENOBUFS;
1184         sock->ops = &smc_sock_ops;
1185         sk = smc_sock_alloc(net, sock);
1186         if (!sk)
1187                 goto out;
1188
1189         /* create internal TCP socket for CLC handshake and fallback */
1190         smc = smc_sk(sk);
1191         smc->use_fallback = false; /* assume rdma capability first */
1192         rc = sock_create_kern(net, PF_INET, SOCK_STREAM,
1193                               IPPROTO_TCP, &smc->clcsock);
1194         if (rc)
1195                 sk_common_release(sk);
1196         smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
1197         smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
1198
1199 out:
1200         return rc;
1201 }
1202
1203 static const struct net_proto_family smc_sock_family_ops = {
1204         .family = PF_SMC,
1205         .owner  = THIS_MODULE,
1206         .create = smc_create,
1207 };
1208
1209 static int __init smc_init(void)
1210 {
1211         int rc;
1212
1213         rc = smc_pnet_init();
1214         if (rc)
1215                 return rc;
1216
1217         rc = smc_llc_init();
1218         if (rc) {
1219                 pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
1220                 goto out_pnet;
1221         }
1222
1223         rc = smc_cdc_init();
1224         if (rc) {
1225                 pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
1226                 goto out_pnet;
1227         }
1228
1229         rc = proto_register(&smc_proto, 1);
1230         if (rc) {
1231                 pr_err("%s: proto_register fails with %d\n", __func__, rc);
1232                 goto out_pnet;
1233         }
1234
1235         rc = sock_register(&smc_sock_family_ops);
1236         if (rc) {
1237                 pr_err("%s: sock_register fails with %d\n", __func__, rc);
1238                 goto out_proto;
1239         }
1240
1241         rc = smc_ib_register_client();
1242         if (rc) {
1243                 pr_err("%s: ib_register fails with %d\n", __func__, rc);
1244                 goto out_sock;
1245         }
1246
1247         return 0;
1248
1249 out_sock:
1250         sock_unregister(PF_SMC);
1251 out_proto:
1252         proto_unregister(&smc_proto);
1253 out_pnet:
1254         smc_pnet_exit();
1255         return rc;
1256 }
1257
1258 static void __exit smc_exit(void)
1259 {
1260         struct smc_link_group *lgr, *lg;
1261         LIST_HEAD(lgr_freeing_list);
1262
1263         spin_lock_bh(&smc_lgr_list.lock);
1264         if (!list_empty(&smc_lgr_list.list))
1265                 list_splice_init(&smc_lgr_list.list, &lgr_freeing_list);
1266         spin_unlock_bh(&smc_lgr_list.lock);
1267         list_for_each_entry_safe(lgr, lg, &lgr_freeing_list, list) {
1268                 list_del_init(&lgr->list);
1269                 smc_lgr_free(lgr); /* free link group */
1270         }
1271         smc_ib_unregister_client();
1272         sock_unregister(PF_SMC);
1273         proto_unregister(&smc_proto);
1274         smc_pnet_exit();
1275 }
1276
1277 module_init(smc_init);
1278 module_exit(smc_exit);
1279
1280 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
1281 MODULE_DESCRIPTION("smc socket address family");
1282 MODULE_LICENSE("GPL");
1283 MODULE_ALIAS_NETPROTO(PF_SMC);