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, unsigned long timeout)
 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         clc_sk->sk_rcvtimeo = timeout;
 289         iov_iter_kvec(&msg.msg_iter, READ, &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                 if (clc_sk->sk_err == EAGAIN &&
 301                     expected_type == SMC_CLC_DECLINE)
 302                         clc_sk->sk_err = 0; /* reset for fallback usage */
 303                 else
 304                         smc->sk.sk_err = clc_sk->sk_err;
 305                 goto out;
 306         }
 307         if (!len) { /* peer has performed orderly shutdown */
 308                 smc->sk.sk_err = ECONNRESET;
 309                 reason_code = -ECONNRESET;
 310                 goto out;
 311         }
 312         if (len < 0) {
 313                 if (len != -EAGAIN || expected_type != SMC_CLC_DECLINE)
 314                         smc->sk.sk_err = -len;
 315                 reason_code = len;
 316                 goto out;
 317         }
 318         datlen = ntohs(clcm->length);
 319         if ((len < sizeof(struct smc_clc_msg_hdr)) ||
 320             (datlen > buflen) ||
 321             (clcm->version != SMC_CLC_V1) ||
 322             (clcm->path != SMC_TYPE_R && clcm->path != SMC_TYPE_D &&
 323              clcm->path != SMC_TYPE_B) ||
 324             ((clcm->type != SMC_CLC_DECLINE) &&
 325              (clcm->type != expected_type))) {
 326                 smc->sk.sk_err = EPROTO;
 327                 reason_code = -EPROTO;
 328                 goto out;
 329         }
 330
 331         /* receive the complete CLC message */
 332         memset(&msg, 0, sizeof(struct msghdr));
 333         iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, datlen);
 334         krflags = MSG_WAITALL;
 335         len = sock_recvmsg(smc->clcsock, &msg, krflags);
 336         if (len < datlen || !smc_clc_msg_hdr_valid(clcm)) {
 337                 smc->sk.sk_err = EPROTO;
 338                 reason_code = -EPROTO;
 339                 goto out;
 340         }
 341         if (clcm->type == SMC_CLC_DECLINE) {
 342                 struct smc_clc_msg_decline *dclc;
 343
 344                 dclc = (struct smc_clc_msg_decline *)clcm;
 345                 reason_code = SMC_CLC_DECL_PEERDECL;
 346                 smc->peer_diagnosis = ntohl(dclc->peer_diagnosis);
 347                 if (((struct smc_clc_msg_decline *)buf)->hdr.flag) {
 348                         smc->conn.lgr->sync_err = 1;
 349                         smc_lgr_terminate(smc->conn.lgr);
 350                 }
 351         }
 352
 353 out:
 354         clc_sk->sk_rcvtimeo = rcvtimeo;
 355         return reason_code;
 356 }
 357
 358 /* send CLC DECLINE message across internal TCP socket */
 359 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info)
 360 {
 361         struct smc_clc_msg_decline dclc;
 362         struct msghdr msg;
 363         struct kvec vec;
 364         int len;
 365
 366         memset(&dclc, 0, sizeof(dclc));
 367         memcpy(dclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 368         dclc.hdr.type = SMC_CLC_DECLINE;
 369         dclc.hdr.length = htons(sizeof(struct smc_clc_msg_decline));
 370         dclc.hdr.version = SMC_CLC_V1;
 371         dclc.hdr.flag = (peer_diag_info == SMC_CLC_DECL_SYNCERR) ? 1 : 0;
 372         memcpy(dclc.id_for_peer, local_systemid, sizeof(local_systemid));
 373         dclc.peer_diagnosis = htonl(peer_diag_info);
 374         memcpy(dclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 375
 376         memset(&msg, 0, sizeof(msg));
 377         vec.iov_base = &dclc;
 378         vec.iov_len = sizeof(struct smc_clc_msg_decline);
 379         len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
 380                              sizeof(struct smc_clc_msg_decline));
 381         if (len < 0 || len < sizeof(struct smc_clc_msg_decline))
 382                 len = -EPROTO;
 383         return len > 0 ? 0 : len;
 384 }
 385
 386 /* send CLC PROPOSAL message across internal TCP socket */
 387 int smc_clc_send_proposal(struct smc_sock *smc, int smc_type,
 388                           struct smc_ib_device *ibdev, u8 ibport, u8 gid[],
 389                           struct smcd_dev *ismdev)
 390 {
 391         struct smc_clc_ipv6_prefix ipv6_prfx[SMC_CLC_MAX_V6_PREFIX];
 392         struct smc_clc_msg_proposal_prefix pclc_prfx;
 393         struct smc_clc_msg_smcd pclc_smcd;
 394         struct smc_clc_msg_proposal pclc;
 395         struct smc_clc_msg_trail trl;
 396         int len, i, plen, rc;
 397         int reason_code = 0;
 398         struct kvec vec[5];
 399         struct msghdr msg;
 400
 401         /* retrieve ip prefixes for CLC proposal msg */
 402         rc = smc_clc_prfx_set(smc->clcsock, &pclc_prfx, ipv6_prfx);
 403         if (rc)
 404                 return SMC_CLC_DECL_CNFERR; /* configuration error */
 405
 406         /* send SMC Proposal CLC message */
 407         plen = sizeof(pclc) + sizeof(pclc_prfx) +
 408                (pclc_prfx.ipv6_prefixes_cnt * sizeof(ipv6_prfx[0])) +
 409                sizeof(trl);
 410         memset(&pclc, 0, sizeof(pclc));
 411         memcpy(pclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 412         pclc.hdr.type = SMC_CLC_PROPOSAL;
 413         pclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 414         pclc.hdr.path = smc_type;
 415         if (smc_type == SMC_TYPE_R || smc_type == SMC_TYPE_B) {
 416                 /* add SMC-R specifics */
 417                 memcpy(pclc.lcl.id_for_peer, local_systemid,
 418                        sizeof(local_systemid));
 419                 memcpy(&pclc.lcl.gid, gid, SMC_GID_SIZE);
 420                 memcpy(&pclc.lcl.mac, &ibdev->mac[ibport - 1], ETH_ALEN);
 421                 pclc.iparea_offset = htons(0);
 422         }
 423         if (smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B) {
 424                 /* add SMC-D specifics */
 425                 memset(&pclc_smcd, 0, sizeof(pclc_smcd));
 426                 plen += sizeof(pclc_smcd);
 427                 pclc.iparea_offset = htons(SMC_CLC_PROPOSAL_MAX_OFFSET);
 428                 pclc_smcd.gid = ismdev->local_gid;
 429         }
 430         pclc.hdr.length = htons(plen);
 431
 432         memcpy(trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 433         memset(&msg, 0, sizeof(msg));
 434         i = 0;
 435         vec[i].iov_base = &pclc;
 436         vec[i++].iov_len = sizeof(pclc);
 437         if (smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B) {
 438                 vec[i].iov_base = &pclc_smcd;
 439                 vec[i++].iov_len = sizeof(pclc_smcd);
 440         }
 441         vec[i].iov_base = &pclc_prfx;
 442         vec[i++].iov_len = sizeof(pclc_prfx);
 443         if (pclc_prfx.ipv6_prefixes_cnt > 0) {
 444                 vec[i].iov_base = &ipv6_prfx[0];
 445                 vec[i++].iov_len = pclc_prfx.ipv6_prefixes_cnt *
 446                                    sizeof(ipv6_prfx[0]);
 447         }
 448         vec[i].iov_base = &trl;
 449         vec[i++].iov_len = sizeof(trl);
 450         /* due to the few bytes needed for clc-handshake this cannot block */
 451         len = kernel_sendmsg(smc->clcsock, &msg, vec, i, plen);
 452         if (len < 0) {
 453                 smc->sk.sk_err = smc->clcsock->sk->sk_err;
 454                 reason_code = -smc->sk.sk_err;
 455         } else if (len < (int)sizeof(pclc)) {
 456                 reason_code = -ENETUNREACH;
 457                 smc->sk.sk_err = -reason_code;
 458         }
 459
 460         return reason_code;
 461 }
 462
 463 /* send CLC CONFIRM message across internal TCP socket */
 464 int smc_clc_send_confirm(struct smc_sock *smc)
 465 {
 466         struct smc_connection *conn = &smc->conn;
 467         struct smc_clc_msg_accept_confirm cclc;
 468         struct smc_link *link;
 469         int reason_code = 0;
 470         struct msghdr msg;
 471         struct kvec vec;
 472         int len;
 473
 474         /* send SMC Confirm CLC msg */
 475         memset(&cclc, 0, sizeof(cclc));
 476         cclc.hdr.type = SMC_CLC_CONFIRM;
 477         cclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 478         if (smc->conn.lgr->is_smcd) {
 479                 /* SMC-D specific settings */
 480                 memcpy(cclc.hdr.eyecatcher, SMCD_EYECATCHER,
 481                        sizeof(SMCD_EYECATCHER));
 482                 cclc.hdr.path = SMC_TYPE_D;
 483                 cclc.hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
 484                 cclc.gid = conn->lgr->smcd->local_gid;
 485                 cclc.token = conn->rmb_desc->token;
 486                 cclc.dmbe_size = conn->rmbe_size_short;
 487                 cclc.dmbe_idx = 0;
 488                 memcpy(&cclc.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
 489                 memcpy(cclc.smcd_trl.eyecatcher, SMCD_EYECATCHER,
 490                        sizeof(SMCD_EYECATCHER));
 491         } else {
 492                 /* SMC-R specific settings */
 493                 link = &conn->lgr->lnk[SMC_SINGLE_LINK];
 494                 memcpy(cclc.hdr.eyecatcher, SMC_EYECATCHER,
 495                        sizeof(SMC_EYECATCHER));
 496                 cclc.hdr.path = SMC_TYPE_R;
 497                 cclc.hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
 498                 memcpy(cclc.lcl.id_for_peer, local_systemid,
 499                        sizeof(local_systemid));
 500                 memcpy(&cclc.lcl.gid, link->gid, SMC_GID_SIZE);
 501                 memcpy(&cclc.lcl.mac, &link->smcibdev->mac[link->ibport - 1],
 502                        ETH_ALEN);
 503                 hton24(cclc.qpn, link->roce_qp->qp_num);
 504                 cclc.rmb_rkey =
 505                         htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
 506                 cclc.rmbe_idx = 1; /* for now: 1 RMB = 1 RMBE */
 507                 cclc.rmbe_alert_token = htonl(conn->alert_token_local);
 508                 cclc.qp_mtu = min(link->path_mtu, link->peer_mtu);
 509                 cclc.rmbe_size = conn->rmbe_size_short;
 510                 cclc.rmb_dma_addr = cpu_to_be64((u64)sg_dma_address
 511                                 (conn->rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
 512                 hton24(cclc.psn, link->psn_initial);
 513                 memcpy(cclc.smcr_trl.eyecatcher, SMC_EYECATCHER,
 514                        sizeof(SMC_EYECATCHER));
 515         }
 516
 517         memset(&msg, 0, sizeof(msg));
 518         vec.iov_base = &cclc;
 519         vec.iov_len = ntohs(cclc.hdr.length);
 520         len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
 521                              ntohs(cclc.hdr.length));
 522         if (len < ntohs(cclc.hdr.length)) {
 523                 if (len >= 0) {
 524                         reason_code = -ENETUNREACH;
 525                         smc->sk.sk_err = -reason_code;
 526                 } else {
 527                         smc->sk.sk_err = smc->clcsock->sk->sk_err;
 528                         reason_code = -smc->sk.sk_err;
 529                 }
 530         }
 531         return reason_code;
 532 }
 533
 534 /* send CLC ACCEPT message across internal TCP socket */
 535 int smc_clc_send_accept(struct smc_sock *new_smc, int srv_first_contact)
 536 {
 537         struct smc_connection *conn = &new_smc->conn;
 538         struct smc_clc_msg_accept_confirm aclc;
 539         struct smc_link *link;
 540         struct msghdr msg;
 541         struct kvec vec;
 542         int len;
 543
 544         memset(&aclc, 0, sizeof(aclc));
 545         aclc.hdr.type = SMC_CLC_ACCEPT;
 546         aclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 547         if (srv_first_contact)
 548                 aclc.hdr.flag = 1;
 549
 550         if (new_smc->conn.lgr->is_smcd) {
 551                 /* SMC-D specific settings */
 552                 aclc.hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
 553                 memcpy(aclc.hdr.eyecatcher, SMCD_EYECATCHER,
 554                        sizeof(SMCD_EYECATCHER));
 555                 aclc.hdr.path = SMC_TYPE_D;
 556                 aclc.gid = conn->lgr->smcd->local_gid;
 557                 aclc.token = conn->rmb_desc->token;
 558                 aclc.dmbe_size = conn->rmbe_size_short;
 559                 aclc.dmbe_idx = 0;
 560                 memcpy(&aclc.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
 561                 memcpy(aclc.smcd_trl.eyecatcher, SMCD_EYECATCHER,
 562                        sizeof(SMCD_EYECATCHER));
 563         } else {
 564                 /* SMC-R specific settings */
 565                 aclc.hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
 566                 memcpy(aclc.hdr.eyecatcher, SMC_EYECATCHER,
 567                        sizeof(SMC_EYECATCHER));
 568                 aclc.hdr.path = SMC_TYPE_R;
 569                 link = &conn->lgr->lnk[SMC_SINGLE_LINK];
 570                 memcpy(aclc.lcl.id_for_peer, local_systemid,
 571                        sizeof(local_systemid));
 572                 memcpy(&aclc.lcl.gid, link->gid, SMC_GID_SIZE);
 573                 memcpy(&aclc.lcl.mac, link->smcibdev->mac[link->ibport - 1],
 574                        ETH_ALEN);
 575                 hton24(aclc.qpn, link->roce_qp->qp_num);
 576                 aclc.rmb_rkey =
 577                         htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
 578                 aclc.rmbe_idx = 1;              /* as long as 1 RMB = 1 RMBE */
 579                 aclc.rmbe_alert_token = htonl(conn->alert_token_local);
 580                 aclc.qp_mtu = link->path_mtu;
 581                 aclc.rmbe_size = conn->rmbe_size_short,
 582                 aclc.rmb_dma_addr = cpu_to_be64((u64)sg_dma_address
 583                                 (conn->rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
 584                 hton24(aclc.psn, link->psn_initial);
 585                 memcpy(aclc.smcr_trl.eyecatcher, SMC_EYECATCHER,
 586                        sizeof(SMC_EYECATCHER));
 587         }
 588
 589         memset(&msg, 0, sizeof(msg));
 590         vec.iov_base = &aclc;
 591         vec.iov_len = ntohs(aclc.hdr.length);
 592         len = kernel_sendmsg(new_smc->clcsock, &msg, &vec, 1,
 593                              ntohs(aclc.hdr.length));
 594         if (len < ntohs(aclc.hdr.length))
 595                 len = len >= 0 ? -EPROTO : -new_smc->clcsock->sk->sk_err;
 596
 597         return len > 0 ? 0 : len;
 598 }