net/smc/smc_clc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
   4  *
   5  *  CLC (connection layer control) handshake over initial TCP socket to
   6  *  prepare for RDMA traffic
   7  *
   8  *  Copyright IBM Corp. 2016, 2018
   9  *
  10  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
  11  */
  12
  13 #include <linux/in.h>
  14 #include <linux/inetdevice.h>
  15 #include <linux/if_ether.h>
  16 #include <linux/sched/signal.h>
  17
  18 #include <net/addrconf.h>
  19 #include <net/sock.h>
  20 #include <net/tcp.h>
  21
  22 #include "smc.h"
  23 #include "smc_core.h"
  24 #include "smc_clc.h"
  25 #include "smc_ib.h"
  26 #include "smc_ism.h"
  27
  28 #define SMCR_CLC_ACCEPT_CONFIRM_LEN 68
  29 #define SMCD_CLC_ACCEPT_CONFIRM_LEN 48
  30
  31 /* eye catcher "SMCR" EBCDIC for CLC messages */
  32 static const char SMC_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xd9'};
  33 /* eye catcher "SMCD" EBCDIC for CLC messages */
  34 static const char SMCD_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xc4'};
  35
  36 /* check if received message has a correct header length and contains valid
  37  * heading and trailing eyecatchers
  38  */
  39 static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm)
  40 {
  41         struct smc_clc_msg_proposal_prefix *pclc_prfx;
  42         struct smc_clc_msg_accept_confirm *clc;
  43         struct smc_clc_msg_proposal *pclc;
  44         struct smc_clc_msg_decline *dclc;
  45         struct smc_clc_msg_trail *trl;
  46
  47         if (memcmp(clcm->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
  48             memcmp(clcm->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
  49                 return false;
  50         switch (clcm->type) {
  51         case SMC_CLC_PROPOSAL:
  52                 if (clcm->path != SMC_TYPE_R && clcm->path != SMC_TYPE_D &&
  53                     clcm->path != SMC_TYPE_B)
  54                         return false;
  55                 pclc = (struct smc_clc_msg_proposal *)clcm;
  56                 pclc_prfx = smc_clc_proposal_get_prefix(pclc);
  57                 if (ntohs(pclc->hdr.length) !=
  58                         sizeof(*pclc) + ntohs(pclc->iparea_offset) +
  59                         sizeof(*pclc_prfx) +
  60                         pclc_prfx->ipv6_prefixes_cnt *
  61                                 sizeof(struct smc_clc_ipv6_prefix) +
  62                         sizeof(*trl))
  63                         return false;
  64                 trl = (struct smc_clc_msg_trail *)
  65                         ((u8 *)pclc + ntohs(pclc->hdr.length) - sizeof(*trl));
  66                 break;
  67         case SMC_CLC_ACCEPT:
  68         case SMC_CLC_CONFIRM:
  69                 if (clcm->path != SMC_TYPE_R && clcm->path != SMC_TYPE_D)
  70                         return false;
  71                 clc = (struct smc_clc_msg_accept_confirm *)clcm;
  72                 if ((clcm->path == SMC_TYPE_R &&
  73                      ntohs(clc->hdr.length) != SMCR_CLC_ACCEPT_CONFIRM_LEN) ||
  74                     (clcm->path == SMC_TYPE_D &&
  75                      ntohs(clc->hdr.length) != SMCD_CLC_ACCEPT_CONFIRM_LEN))
  76                         return false;
  77                 trl = (struct smc_clc_msg_trail *)
  78                         ((u8 *)clc + ntohs(clc->hdr.length) - sizeof(*trl));
  79                 break;
  80         case SMC_CLC_DECLINE:
  81                 dclc = (struct smc_clc_msg_decline *)clcm;
  82                 if (ntohs(dclc->hdr.length) != sizeof(*dclc))
  83                         return false;
  84                 trl = &dclc->trl;
  85                 break;
  86         default:
  87                 return false;
  88         }
  89         if (memcmp(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
  90             memcmp(trl->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
  91                 return false;
  92         return true;
  93 }
  94
  95 /* find ipv4 addr on device and get the prefix len, fill CLC proposal msg */
  96 static int smc_clc_prfx_set4_rcu(struct dst_entry *dst, __be32 ipv4,
  97                                  struct smc_clc_msg_proposal_prefix *prop)
  98 {
  99         struct in_device *in_dev = __in_dev_get_rcu(dst->dev);
 100
 101         if (!in_dev)
 102                 return -ENODEV;
 103         for_ifa(in_dev) {
 104                 if (!inet_ifa_match(ipv4, ifa))
 105                         continue;
 106                 prop->prefix_len = inet_mask_len(ifa->ifa_mask);
 107                 prop->outgoing_subnet = ifa->ifa_address & ifa->ifa_mask;
 108                 /* prop->ipv6_prefixes_cnt = 0; already done by memset before */
 109                 return 0;
 110         } endfor_ifa(in_dev);
 111         return -ENOENT;
 112 }
 113
 114 /* fill CLC proposal msg with ipv6 prefixes from device */
 115 static int smc_clc_prfx_set6_rcu(struct dst_entry *dst,
 116                                  struct smc_clc_msg_proposal_prefix *prop,
 117                                  struct smc_clc_ipv6_prefix *ipv6_prfx)
 118 {
 119 #if IS_ENABLED(CONFIG_IPV6)
 120         struct inet6_dev *in6_dev = __in6_dev_get(dst->dev);
 121         struct inet6_ifaddr *ifa;
 122         int cnt = 0;
 123
 124         if (!in6_dev)
 125                 return -ENODEV;
 126         /* use a maximum of 8 IPv6 prefixes from device */
 127         list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
 128                 if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
 129                         continue;
 130                 ipv6_addr_prefix(&ipv6_prfx[cnt].prefix,
 131                                  &ifa->addr, ifa->prefix_len);
 132                 ipv6_prfx[cnt].prefix_len = ifa->prefix_len;
 133                 cnt++;
 134                 if (cnt == SMC_CLC_MAX_V6_PREFIX)
 135                         break;
 136         }
 137         prop->ipv6_prefixes_cnt = cnt;
 138         if (cnt)
 139                 return 0;
 140 #endif
 141         return -ENOENT;
 142 }
 143
 144 /* retrieve and set prefixes in CLC proposal msg */
 145 static int smc_clc_prfx_set(struct socket *clcsock,
 146                             struct smc_clc_msg_proposal_prefix *prop,
 147                             struct smc_clc_ipv6_prefix *ipv6_prfx)
 148 {
 149         struct dst_entry *dst = sk_dst_get(clcsock->sk);
 150         struct sockaddr_storage addrs;
 151         struct sockaddr_in6 *addr6;
 152         struct sockaddr_in *addr;
 153         int rc = -ENOENT;
 154
 155         memset(prop, 0, sizeof(*prop));
 156         if (!dst) {
 157                 rc = -ENOTCONN;
 158                 goto out;
 159         }
 160         if (!dst->dev) {
 161                 rc = -ENODEV;
 162                 goto out_rel;
 163         }
 164         /* get address to which the internal TCP socket is bound */
 165         kernel_getsockname(clcsock, (struct sockaddr *)&addrs);
 166         /* analyze IP specific data of net_device belonging to TCP socket */
 167         addr6 = (struct sockaddr_in6 *)&addrs;
 168         rcu_read_lock();
 169         if (addrs.ss_family == PF_INET) {
 170                 /* IPv4 */
 171                 addr = (struct sockaddr_in *)&addrs;
 172                 rc = smc_clc_prfx_set4_rcu(dst, addr->sin_addr.s_addr, prop);
 173         } else if (ipv6_addr_v4mapped(&addr6->sin6_addr)) {
 174                 /* mapped IPv4 address - peer is IPv4 only */
 175                 rc = smc_clc_prfx_set4_rcu(dst, addr6->sin6_addr.s6_addr32[3],
 176                                            prop);
 177         } else {
 178                 /* IPv6 */
 179                 rc = smc_clc_prfx_set6_rcu(dst, prop, ipv6_prfx);
 180         }
 181         rcu_read_unlock();
 182 out_rel:
 183         dst_release(dst);
 184 out:
 185         return rc;
 186 }
 187
 188 /* match ipv4 addrs of dev against addr in CLC proposal */
 189 static int smc_clc_prfx_match4_rcu(struct net_device *dev,
 190                                    struct smc_clc_msg_proposal_prefix *prop)
 191 {
 192         struct in_device *in_dev = __in_dev_get_rcu(dev);
 193
 194         if (!in_dev)
 195                 return -ENODEV;
 196         for_ifa(in_dev) {
 197                 if (prop->prefix_len == inet_mask_len(ifa->ifa_mask) &&
 198                     inet_ifa_match(prop->outgoing_subnet, ifa))
 199                         return 0;
 200         } endfor_ifa(in_dev);
 201
 202         return -ENOENT;
 203 }
 204
 205 /* match ipv6 addrs of dev against addrs in CLC proposal */
 206 static int smc_clc_prfx_match6_rcu(struct net_device *dev,
 207                                    struct smc_clc_msg_proposal_prefix *prop)
 208 {
 209 #if IS_ENABLED(CONFIG_IPV6)
 210         struct inet6_dev *in6_dev = __in6_dev_get(dev);
 211         struct smc_clc_ipv6_prefix *ipv6_prfx;
 212         struct inet6_ifaddr *ifa;
 213         int i, max;
 214
 215         if (!in6_dev)
 216                 return -ENODEV;
 217         /* ipv6 prefix list starts behind smc_clc_msg_proposal_prefix */
 218         ipv6_prfx = (struct smc_clc_ipv6_prefix *)((u8 *)prop + sizeof(*prop));
 219         max = min_t(u8, prop->ipv6_prefixes_cnt, SMC_CLC_MAX_V6_PREFIX);
 220         list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
 221                 if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
 222                         continue;
 223                 for (i = 0; i < max; i++) {
 224                         if (ifa->prefix_len == ipv6_prfx[i].prefix_len &&
 225                             ipv6_prefix_equal(&ifa->addr, &ipv6_prfx[i].prefix,
 226                                               ifa->prefix_len))
 227                                 return 0;
 228                 }
 229         }
 230 #endif
 231         return -ENOENT;
 232 }
 233
 234 /* check if proposed prefixes match one of our device prefixes */
 235 int smc_clc_prfx_match(struct socket *clcsock,
 236                        struct smc_clc_msg_proposal_prefix *prop)
 237 {
 238         struct dst_entry *dst = sk_dst_get(clcsock->sk);
 239         int rc;
 240
 241         if (!dst) {
 242                 rc = -ENOTCONN;
 243                 goto out;
 244         }
 245         if (!dst->dev) {
 246                 rc = -ENODEV;
 247                 goto out_rel;
 248         }
 249         rcu_read_lock();
 250         if (!prop->ipv6_prefixes_cnt)
 251                 rc = smc_clc_prfx_match4_rcu(dst->dev, prop);
 252         else
 253                 rc = smc_clc_prfx_match6_rcu(dst->dev, prop);
 254         rcu_read_unlock();
 255 out_rel:
 256         dst_release(dst);
 257 out:
 258         return rc;
 259 }
 260
 261 /* Wait for data on the tcp-socket, analyze received data
 262  * Returns:
 263  * 0 if success and it was not a decline that we received.
 264  * SMC_CLC_DECL_REPLY if decline received for fallback w/o another decl send.
 265  * clcsock error, -EINTR, -ECONNRESET, -EPROTO otherwise.
 266  */
 267 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 268                      u8 expected_type)
 269 {
 270         long rcvtimeo = smc->clcsock->sk->sk_rcvtimeo;
 271         struct sock *clc_sk = smc->clcsock->sk;
 272         struct smc_clc_msg_hdr *clcm = buf;
 273         struct msghdr msg = {NULL, 0};
 274         int reason_code = 0;
 275         struct kvec vec = {buf, buflen};
 276         int len, datlen;
 277         int krflags;
 278
 279         /* peek the first few bytes to determine length of data to receive
 280          * so we don't consume any subsequent CLC message or payload data
 281          * in the TCP byte stream
 282          */
 283         /*
 284          * Caller must make sure that buflen is no less than
 285          * sizeof(struct smc_clc_msg_hdr)
 286          */
 287         krflags = MSG_PEEK | MSG_WAITALL;
 288         smc->clcsock->sk->sk_rcvtimeo = CLC_WAIT_TIME;
 289         iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &vec, 1,
 290                         sizeof(struct smc_clc_msg_hdr));
 291         len = sock_recvmsg(smc->clcsock, &msg, krflags);
 292         if (signal_pending(current)) {
 293                 reason_code = -EINTR;
 294                 clc_sk->sk_err = EINTR;
 295                 smc->sk.sk_err = EINTR;
 296                 goto out;
 297         }
 298         if (clc_sk->sk_err) {
 299                 reason_code = -clc_sk->sk_err;
 300                 smc->sk.sk_err = clc_sk->sk_err;
 301                 goto out;
 302         }
 303         if (!len) { /* peer has performed orderly shutdown */
 304                 smc->sk.sk_err = ECONNRESET;
 305                 reason_code = -ECONNRESET;
 306                 goto out;
 307         }
 308         if (len < 0) {
 309                 smc->sk.sk_err = -len;
 310                 reason_code = len;
 311                 goto out;
 312         }
 313         datlen = ntohs(clcm->length);
 314         if ((len < sizeof(struct smc_clc_msg_hdr)) ||
 315             (datlen > buflen) ||
 316             (clcm->version != SMC_CLC_V1) ||
 317             (clcm->path != SMC_TYPE_R && clcm->path != SMC_TYPE_D &&
 318              clcm->path != SMC_TYPE_B) ||
 319             ((clcm->type != SMC_CLC_DECLINE) &&
 320              (clcm->type != expected_type))) {
 321                 smc->sk.sk_err = EPROTO;
 322                 reason_code = -EPROTO;
 323                 goto out;
 324         }
 325
 326         /* receive the complete CLC message */
 327         memset(&msg, 0, sizeof(struct msghdr));
 328         iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &vec, 1, datlen);
 329         krflags = MSG_WAITALL;
 330         len = sock_recvmsg(smc->clcsock, &msg, krflags);
 331         if (len < datlen || !smc_clc_msg_hdr_valid(clcm)) {
 332                 smc->sk.sk_err = EPROTO;
 333                 reason_code = -EPROTO;
 334                 goto out;
 335         }
 336         if (clcm->type == SMC_CLC_DECLINE) {
 337                 struct smc_clc_msg_decline *dclc;
 338
 339                 dclc = (struct smc_clc_msg_decline *)clcm;
 340                 reason_code = SMC_CLC_DECL_PEERDECL;
 341                 smc->peer_diagnosis = ntohl(dclc->peer_diagnosis);
 342                 if (((struct smc_clc_msg_decline *)buf)->hdr.flag) {
 343                         smc->conn.lgr->sync_err = 1;
 344                         smc_lgr_terminate(smc->conn.lgr);
 345                 }
 346         }
 347
 348 out:
 349         smc->clcsock->sk->sk_rcvtimeo = rcvtimeo;
 350         return reason_code;
 351 }
 352
 353 /* send CLC DECLINE message across internal TCP socket */
 354 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info)
 355 {
 356         struct smc_clc_msg_decline dclc;
 357         struct msghdr msg;
 358         struct kvec vec;
 359         int len;
 360
 361         memset(&dclc, 0, sizeof(dclc));
 362         memcpy(dclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 363         dclc.hdr.type = SMC_CLC_DECLINE;
 364         dclc.hdr.length = htons(sizeof(struct smc_clc_msg_decline));
 365         dclc.hdr.version = SMC_CLC_V1;
 366         dclc.hdr.flag = (peer_diag_info == SMC_CLC_DECL_SYNCERR) ? 1 : 0;
 367         memcpy(dclc.id_for_peer, local_systemid, sizeof(local_systemid));
 368         dclc.peer_diagnosis = htonl(peer_diag_info);
 369         memcpy(dclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 370
 371         memset(&msg, 0, sizeof(msg));
 372         vec.iov_base = &dclc;
 373         vec.iov_len = sizeof(struct smc_clc_msg_decline);
 374         len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
 375                              sizeof(struct smc_clc_msg_decline));
 376         if (len < sizeof(struct smc_clc_msg_decline))
 377                 smc->sk.sk_err = EPROTO;
 378         if (len < 0)
 379                 smc->sk.sk_err = -len;
 380         return sock_error(&smc->sk);
 381 }
 382
 383 /* send CLC PROPOSAL message across internal TCP socket */
 384 int smc_clc_send_proposal(struct smc_sock *smc, int smc_type,
 385                           struct smc_ib_device *ibdev, u8 ibport, u8 gid[],
 386                           struct smcd_dev *ismdev)
 387 {
 388         struct smc_clc_ipv6_prefix ipv6_prfx[SMC_CLC_MAX_V6_PREFIX];
 389         struct smc_clc_msg_proposal_prefix pclc_prfx;
 390         struct smc_clc_msg_smcd pclc_smcd;
 391         struct smc_clc_msg_proposal pclc;
 392         struct smc_clc_msg_trail trl;
 393         int len, i, plen, rc;
 394         int reason_code = 0;
 395         struct kvec vec[5];
 396         struct msghdr msg;
 397
 398         /* retrieve ip prefixes for CLC proposal msg */
 399         rc = smc_clc_prfx_set(smc->clcsock, &pclc_prfx, ipv6_prfx);
 400         if (rc)
 401                 return SMC_CLC_DECL_CNFERR; /* configuration error */
 402
 403         /* send SMC Proposal CLC message */
 404         plen = sizeof(pclc) + sizeof(pclc_prfx) +
 405                (pclc_prfx.ipv6_prefixes_cnt * sizeof(ipv6_prfx[0])) +
 406                sizeof(trl);
 407         memset(&pclc, 0, sizeof(pclc));
 408         memcpy(pclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 409         pclc.hdr.type = SMC_CLC_PROPOSAL;
 410         pclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 411         pclc.hdr.path = smc_type;
 412         if (smc_type == SMC_TYPE_R || smc_type == SMC_TYPE_B) {
 413                 /* add SMC-R specifics */
 414                 memcpy(pclc.lcl.id_for_peer, local_systemid,
 415                        sizeof(local_systemid));
 416                 memcpy(&pclc.lcl.gid, gid, SMC_GID_SIZE);
 417                 memcpy(&pclc.lcl.mac, &ibdev->mac[ibport - 1], ETH_ALEN);
 418                 pclc.iparea_offset = htons(0);
 419         }
 420         if (smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B) {
 421                 /* add SMC-D specifics */
 422                 memset(&pclc_smcd, 0, sizeof(pclc_smcd));
 423                 plen += sizeof(pclc_smcd);
 424                 pclc.iparea_offset = htons(SMC_CLC_PROPOSAL_MAX_OFFSET);
 425                 pclc_smcd.gid = ismdev->local_gid;
 426         }
 427         pclc.hdr.length = htons(plen);
 428
 429         memcpy(trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 430         memset(&msg, 0, sizeof(msg));
 431         i = 0;
 432         vec[i].iov_base = &pclc;
 433         vec[i++].iov_len = sizeof(pclc);
 434         if (smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B) {
 435                 vec[i].iov_base = &pclc_smcd;
 436                 vec[i++].iov_len = sizeof(pclc_smcd);
 437         }
 438         vec[i].iov_base = &pclc_prfx;
 439         vec[i++].iov_len = sizeof(pclc_prfx);
 440         if (pclc_prfx.ipv6_prefixes_cnt > 0) {
 441                 vec[i].iov_base = &ipv6_prfx[0];
 442                 vec[i++].iov_len = pclc_prfx.ipv6_prefixes_cnt *
 443                                    sizeof(ipv6_prfx[0]);
 444         }
 445         vec[i].iov_base = &trl;
 446         vec[i++].iov_len = sizeof(trl);
 447         /* due to the few bytes needed for clc-handshake this cannot block */
 448         len = kernel_sendmsg(smc->clcsock, &msg, vec, i, plen);
 449         if (len < 0) {
 450                 smc->sk.sk_err = smc->clcsock->sk->sk_err;
 451                 reason_code = -smc->sk.sk_err;
 452         } else if (len < (int)sizeof(pclc)) {
 453                 reason_code = -ENETUNREACH;
 454                 smc->sk.sk_err = -reason_code;
 455         }
 456
 457         return reason_code;
 458 }
 459
 460 /* send CLC CONFIRM message across internal TCP socket */
 461 int smc_clc_send_confirm(struct smc_sock *smc)
 462 {
 463         struct smc_connection *conn = &smc->conn;
 464         struct smc_clc_msg_accept_confirm cclc;
 465         struct smc_link *link;
 466         int reason_code = 0;
 467         struct msghdr msg;
 468         struct kvec vec;
 469         int len;
 470
 471         /* send SMC Confirm CLC msg */
 472         memset(&cclc, 0, sizeof(cclc));
 473         cclc.hdr.type = SMC_CLC_CONFIRM;
 474         cclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 475         if (smc->conn.lgr->is_smcd) {
 476                 /* SMC-D specific settings */
 477                 memcpy(cclc.hdr.eyecatcher, SMCD_EYECATCHER,
 478                        sizeof(SMCD_EYECATCHER));
 479                 cclc.hdr.path = SMC_TYPE_D;
 480                 cclc.hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
 481                 cclc.gid = conn->lgr->smcd->local_gid;
 482                 cclc.token = conn->rmb_desc->token;
 483                 cclc.dmbe_size = conn->rmbe_size_short;
 484                 cclc.dmbe_idx = 0;
 485                 memcpy(&cclc.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
 486                 memcpy(cclc.smcd_trl.eyecatcher, SMCD_EYECATCHER,
 487                        sizeof(SMCD_EYECATCHER));
 488         } else {
 489                 /* SMC-R specific settings */
 490                 link = &conn->lgr->lnk[SMC_SINGLE_LINK];
 491                 memcpy(cclc.hdr.eyecatcher, SMC_EYECATCHER,
 492                        sizeof(SMC_EYECATCHER));
 493                 cclc.hdr.path = SMC_TYPE_R;
 494                 cclc.hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
 495                 memcpy(cclc.lcl.id_for_peer, local_systemid,
 496                        sizeof(local_systemid));
 497                 memcpy(&cclc.lcl.gid, link->gid, SMC_GID_SIZE);
 498                 memcpy(&cclc.lcl.mac, &link->smcibdev->mac[link->ibport - 1],
 499                        ETH_ALEN);
 500                 hton24(cclc.qpn, link->roce_qp->qp_num);
 501                 cclc.rmb_rkey =
 502                         htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
 503                 cclc.rmbe_idx = 1; /* for now: 1 RMB = 1 RMBE */
 504                 cclc.rmbe_alert_token = htonl(conn->alert_token_local);
 505                 cclc.qp_mtu = min(link->path_mtu, link->peer_mtu);
 506                 cclc.rmbe_size = conn->rmbe_size_short;
 507                 cclc.rmb_dma_addr = cpu_to_be64((u64)sg_dma_address
 508                                 (conn->rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
 509                 hton24(cclc.psn, link->psn_initial);
 510                 memcpy(cclc.smcr_trl.eyecatcher, SMC_EYECATCHER,
 511                        sizeof(SMC_EYECATCHER));
 512         }
 513
 514         memset(&msg, 0, sizeof(msg));
 515         vec.iov_base = &cclc;
 516         vec.iov_len = ntohs(cclc.hdr.length);
 517         len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
 518                              ntohs(cclc.hdr.length));
 519         if (len < ntohs(cclc.hdr.length)) {
 520                 if (len >= 0) {
 521                         reason_code = -ENETUNREACH;
 522                         smc->sk.sk_err = -reason_code;
 523                 } else {
 524                         smc->sk.sk_err = smc->clcsock->sk->sk_err;
 525                         reason_code = -smc->sk.sk_err;
 526                 }
 527         }
 528         return reason_code;
 529 }
 530
 531 /* send CLC ACCEPT message across internal TCP socket */
 532 int smc_clc_send_accept(struct smc_sock *new_smc, int srv_first_contact)
 533 {
 534         struct smc_connection *conn = &new_smc->conn;
 535         struct smc_clc_msg_accept_confirm aclc;
 536         struct smc_link *link;
 537         struct msghdr msg;
 538         struct kvec vec;
 539         int rc = 0;
 540         int len;
 541
 542         memset(&aclc, 0, sizeof(aclc));
 543         aclc.hdr.type = SMC_CLC_ACCEPT;
 544         aclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 545         if (srv_first_contact)
 546                 aclc.hdr.flag = 1;
 547
 548         if (new_smc->conn.lgr->is_smcd) {
 549                 /* SMC-D specific settings */
 550                 aclc.hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
 551                 memcpy(aclc.hdr.eyecatcher, SMCD_EYECATCHER,
 552                        sizeof(SMCD_EYECATCHER));
 553                 aclc.hdr.path = SMC_TYPE_D;
 554                 aclc.gid = conn->lgr->smcd->local_gid;
 555                 aclc.token = conn->rmb_desc->token;
 556                 aclc.dmbe_size = conn->rmbe_size_short;
 557                 aclc.dmbe_idx = 0;
 558                 memcpy(&aclc.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
 559                 memcpy(aclc.smcd_trl.eyecatcher, SMCD_EYECATCHER,
 560                        sizeof(SMCD_EYECATCHER));
 561         } else {
 562                 /* SMC-R specific settings */
 563                 aclc.hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
 564                 memcpy(aclc.hdr.eyecatcher, SMC_EYECATCHER,
 565                        sizeof(SMC_EYECATCHER));
 566                 aclc.hdr.path = SMC_TYPE_R;
 567                 link = &conn->lgr->lnk[SMC_SINGLE_LINK];
 568                 memcpy(aclc.lcl.id_for_peer, local_systemid,
 569                        sizeof(local_systemid));
 570                 memcpy(&aclc.lcl.gid, link->gid, SMC_GID_SIZE);
 571                 memcpy(&aclc.lcl.mac, link->smcibdev->mac[link->ibport - 1],
 572                        ETH_ALEN);
 573                 hton24(aclc.qpn, link->roce_qp->qp_num);
 574                 aclc.rmb_rkey =
 575                         htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
 576                 aclc.rmbe_idx = 1;              /* as long as 1 RMB = 1 RMBE */
 577                 aclc.rmbe_alert_token = htonl(conn->alert_token_local);
 578                 aclc.qp_mtu = link->path_mtu;
 579                 aclc.rmbe_size = conn->rmbe_size_short,
 580                 aclc.rmb_dma_addr = cpu_to_be64((u64)sg_dma_address
 581                                 (conn->rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
 582                 hton24(aclc.psn, link->psn_initial);
 583                 memcpy(aclc.smcr_trl.eyecatcher, SMC_EYECATCHER,
 584                        sizeof(SMC_EYECATCHER));
 585         }
 586
 587         memset(&msg, 0, sizeof(msg));
 588         vec.iov_base = &aclc;
 589         vec.iov_len = ntohs(aclc.hdr.length);
 590         len = kernel_sendmsg(new_smc->clcsock, &msg, &vec, 1,
 591                              ntohs(aclc.hdr.length));
 592         if (len < ntohs(aclc.hdr.length)) {
 593                 if (len >= 0)
 594                         new_smc->sk.sk_err = EPROTO;
 595                 else
 596                         new_smc->sk.sk_err = new_smc->clcsock->sk->sk_err;
 597                 rc = sock_error(&new_smc->sk);
 598         }
 599
 600         return rc;
 601 }