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         const struct in_ifaddr *ifa;
 101
 102         if (!in_dev)
 103                 return -ENODEV;
 104
 105         in_dev_for_each_ifa_rcu(ifa, in_dev) {
 106                 if (!inet_ifa_match(ipv4, ifa))
 107                         continue;
 108                 prop->prefix_len = inet_mask_len(ifa->ifa_mask);
 109                 prop->outgoing_subnet = ifa->ifa_address & ifa->ifa_mask;
 110                 /* prop->ipv6_prefixes_cnt = 0; already done by memset before */
 111                 return 0;
 112         }
 113         return -ENOENT;
 114 }
 115
 116 /* fill CLC proposal msg with ipv6 prefixes from device */
 117 static int smc_clc_prfx_set6_rcu(struct dst_entry *dst,
 118                                  struct smc_clc_msg_proposal_prefix *prop,
 119                                  struct smc_clc_ipv6_prefix *ipv6_prfx)
 120 {
 121 #if IS_ENABLED(CONFIG_IPV6)
 122         struct inet6_dev *in6_dev = __in6_dev_get(dst->dev);
 123         struct inet6_ifaddr *ifa;
 124         int cnt = 0;
 125
 126         if (!in6_dev)
 127                 return -ENODEV;
 128         /* use a maximum of 8 IPv6 prefixes from device */
 129         list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
 130                 if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
 131                         continue;
 132                 ipv6_addr_prefix(&ipv6_prfx[cnt].prefix,
 133                                  &ifa->addr, ifa->prefix_len);
 134                 ipv6_prfx[cnt].prefix_len = ifa->prefix_len;
 135                 cnt++;
 136                 if (cnt == SMC_CLC_MAX_V6_PREFIX)
 137                         break;
 138         }
 139         prop->ipv6_prefixes_cnt = cnt;
 140         if (cnt)
 141                 return 0;
 142 #endif
 143         return -ENOENT;
 144 }
 145
 146 /* retrieve and set prefixes in CLC proposal msg */
 147 static int smc_clc_prfx_set(struct socket *clcsock,
 148                             struct smc_clc_msg_proposal_prefix *prop,
 149                             struct smc_clc_ipv6_prefix *ipv6_prfx)
 150 {
 151         struct dst_entry *dst = sk_dst_get(clcsock->sk);
 152         struct sockaddr_storage addrs;
 153         struct sockaddr_in6 *addr6;
 154         struct sockaddr_in *addr;
 155         int rc = -ENOENT;
 156
 157         memset(prop, 0, sizeof(*prop));
 158         if (!dst) {
 159                 rc = -ENOTCONN;
 160                 goto out;
 161         }
 162         if (!dst->dev) {
 163                 rc = -ENODEV;
 164                 goto out_rel;
 165         }
 166         /* get address to which the internal TCP socket is bound */
 167         kernel_getsockname(clcsock, (struct sockaddr *)&addrs);
 168         /* analyze IP specific data of net_device belonging to TCP socket */
 169         addr6 = (struct sockaddr_in6 *)&addrs;
 170         rcu_read_lock();
 171         if (addrs.ss_family == PF_INET) {
 172                 /* IPv4 */
 173                 addr = (struct sockaddr_in *)&addrs;
 174                 rc = smc_clc_prfx_set4_rcu(dst, addr->sin_addr.s_addr, prop);
 175         } else if (ipv6_addr_v4mapped(&addr6->sin6_addr)) {
 176                 /* mapped IPv4 address - peer is IPv4 only */
 177                 rc = smc_clc_prfx_set4_rcu(dst, addr6->sin6_addr.s6_addr32[3],
 178                                            prop);
 179         } else {
 180                 /* IPv6 */
 181                 rc = smc_clc_prfx_set6_rcu(dst, prop, ipv6_prfx);
 182         }
 183         rcu_read_unlock();
 184 out_rel:
 185         dst_release(dst);
 186 out:
 187         return rc;
 188 }
 189
 190 /* match ipv4 addrs of dev against addr in CLC proposal */
 191 static int smc_clc_prfx_match4_rcu(struct net_device *dev,
 192                                    struct smc_clc_msg_proposal_prefix *prop)
 193 {
 194         struct in_device *in_dev = __in_dev_get_rcu(dev);
 195         const struct in_ifaddr *ifa;
 196
 197         if (!in_dev)
 198                 return -ENODEV;
 199         in_dev_for_each_ifa_rcu(ifa, in_dev) {
 200                 if (prop->prefix_len == inet_mask_len(ifa->ifa_mask) &&
 201                     inet_ifa_match(prop->outgoing_subnet, ifa))
 202                         return 0;
 203         }
 204
 205         return -ENOENT;
 206 }
 207
 208 /* match ipv6 addrs of dev against addrs in CLC proposal */
 209 static int smc_clc_prfx_match6_rcu(struct net_device *dev,
 210                                    struct smc_clc_msg_proposal_prefix *prop)
 211 {
 212 #if IS_ENABLED(CONFIG_IPV6)
 213         struct inet6_dev *in6_dev = __in6_dev_get(dev);
 214         struct smc_clc_ipv6_prefix *ipv6_prfx;
 215         struct inet6_ifaddr *ifa;
 216         int i, max;
 217
 218         if (!in6_dev)
 219                 return -ENODEV;
 220         /* ipv6 prefix list starts behind smc_clc_msg_proposal_prefix */
 221         ipv6_prfx = (struct smc_clc_ipv6_prefix *)((u8 *)prop + sizeof(*prop));
 222         max = min_t(u8, prop->ipv6_prefixes_cnt, SMC_CLC_MAX_V6_PREFIX);
 223         list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
 224                 if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
 225                         continue;
 226                 for (i = 0; i < max; i++) {
 227                         if (ifa->prefix_len == ipv6_prfx[i].prefix_len &&
 228                             ipv6_prefix_equal(&ifa->addr, &ipv6_prfx[i].prefix,
 229                                               ifa->prefix_len))
 230                                 return 0;
 231                 }
 232         }
 233 #endif
 234         return -ENOENT;
 235 }
 236
 237 /* check if proposed prefixes match one of our device prefixes */
 238 int smc_clc_prfx_match(struct socket *clcsock,
 239                        struct smc_clc_msg_proposal_prefix *prop)
 240 {
 241         struct dst_entry *dst = sk_dst_get(clcsock->sk);
 242         int rc;
 243
 244         if (!dst) {
 245                 rc = -ENOTCONN;
 246                 goto out;
 247         }
 248         if (!dst->dev) {
 249                 rc = -ENODEV;
 250                 goto out_rel;
 251         }
 252         rcu_read_lock();
 253         if (!prop->ipv6_prefixes_cnt)
 254                 rc = smc_clc_prfx_match4_rcu(dst->dev, prop);
 255         else
 256                 rc = smc_clc_prfx_match6_rcu(dst->dev, prop);
 257         rcu_read_unlock();
 258 out_rel:
 259         dst_release(dst);
 260 out:
 261         return rc;
 262 }
 263
 264 /* Wait for data on the tcp-socket, analyze received data
 265  * Returns:
 266  * 0 if success and it was not a decline that we received.
 267  * SMC_CLC_DECL_REPLY if decline received for fallback w/o another decl send.
 268  * clcsock error, -EINTR, -ECONNRESET, -EPROTO otherwise.
 269  */
 270 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 271                      u8 expected_type, unsigned long timeout)
 272 {
 273         long rcvtimeo = smc->clcsock->sk->sk_rcvtimeo;
 274         struct sock *clc_sk = smc->clcsock->sk;
 275         struct smc_clc_msg_hdr *clcm = buf;
 276         struct msghdr msg = {NULL, 0};
 277         int reason_code = 0;
 278         struct kvec vec = {buf, buflen};
 279         int len, datlen;
 280         int krflags;
 281
 282         /* peek the first few bytes to determine length of data to receive
 283          * so we don't consume any subsequent CLC message or payload data
 284          * in the TCP byte stream
 285          */
 286         /*
 287          * Caller must make sure that buflen is no less than
 288          * sizeof(struct smc_clc_msg_hdr)
 289          */
 290         krflags = MSG_PEEK | MSG_WAITALL;
 291         clc_sk->sk_rcvtimeo = timeout;
 292         iov_iter_kvec(&msg.msg_iter, READ, &vec, 1,
 293                         sizeof(struct smc_clc_msg_hdr));
 294         len = sock_recvmsg(smc->clcsock, &msg, krflags);
 295         if (signal_pending(current)) {
 296                 reason_code = -EINTR;
 297                 clc_sk->sk_err = EINTR;
 298                 smc->sk.sk_err = EINTR;
 299                 goto out;
 300         }
 301         if (clc_sk->sk_err) {
 302                 reason_code = -clc_sk->sk_err;
 303                 if (clc_sk->sk_err == EAGAIN &&
 304                     expected_type == SMC_CLC_DECLINE)
 305                         clc_sk->sk_err = 0; /* reset for fallback usage */
 306                 else
 307                         smc->sk.sk_err = clc_sk->sk_err;
 308                 goto out;
 309         }
 310         if (!len) { /* peer has performed orderly shutdown */
 311                 smc->sk.sk_err = ECONNRESET;
 312                 reason_code = -ECONNRESET;
 313                 goto out;
 314         }
 315         if (len < 0) {
 316                 if (len != -EAGAIN || expected_type != SMC_CLC_DECLINE)
 317                         smc->sk.sk_err = -len;
 318                 reason_code = len;
 319                 goto out;
 320         }
 321         datlen = ntohs(clcm->length);
 322         if ((len < sizeof(struct smc_clc_msg_hdr)) ||
 323             (datlen > buflen) ||
 324             (clcm->version != SMC_CLC_V1) ||
 325             (clcm->path != SMC_TYPE_R && clcm->path != SMC_TYPE_D &&
 326              clcm->path != SMC_TYPE_B) ||
 327             ((clcm->type != SMC_CLC_DECLINE) &&
 328              (clcm->type != expected_type))) {
 329                 smc->sk.sk_err = EPROTO;
 330                 reason_code = -EPROTO;
 331                 goto out;
 332         }
 333
 334         /* receive the complete CLC message */
 335         memset(&msg, 0, sizeof(struct msghdr));
 336         iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, datlen);
 337         krflags = MSG_WAITALL;
 338         len = sock_recvmsg(smc->clcsock, &msg, krflags);
 339         if (len < datlen || !smc_clc_msg_hdr_valid(clcm)) {
 340                 smc->sk.sk_err = EPROTO;
 341                 reason_code = -EPROTO;
 342                 goto out;
 343         }
 344         if (clcm->type == SMC_CLC_DECLINE) {
 345                 struct smc_clc_msg_decline *dclc;
 346
 347                 dclc = (struct smc_clc_msg_decline *)clcm;
 348                 reason_code = SMC_CLC_DECL_PEERDECL;
 349                 smc->peer_diagnosis = ntohl(dclc->peer_diagnosis);
 350                 if (((struct smc_clc_msg_decline *)buf)->hdr.flag) {
 351                         smc->conn.lgr->sync_err = 1;
 352                         smc_lgr_terminate_sched(smc->conn.lgr);
 353                 }
 354         }
 355
 356 out:
 357         clc_sk->sk_rcvtimeo = rcvtimeo;
 358         return reason_code;
 359 }
 360
 361 /* send CLC DECLINE message across internal TCP socket */
 362 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info)
 363 {
 364         struct smc_clc_msg_decline dclc;
 365         struct msghdr msg;
 366         struct kvec vec;
 367         int len;
 368
 369         memset(&dclc, 0, sizeof(dclc));
 370         memcpy(dclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 371         dclc.hdr.type = SMC_CLC_DECLINE;
 372         dclc.hdr.length = htons(sizeof(struct smc_clc_msg_decline));
 373         dclc.hdr.version = SMC_CLC_V1;
 374         dclc.hdr.flag = (peer_diag_info == SMC_CLC_DECL_SYNCERR) ? 1 : 0;
 375         if ((!smc->conn.lgr || !smc->conn.lgr->is_smcd) &&
 376             smc_ib_is_valid_local_systemid())
 377                 memcpy(dclc.id_for_peer, local_systemid,
 378                        sizeof(local_systemid));
 379         dclc.peer_diagnosis = htonl(peer_diag_info);
 380         memcpy(dclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 381
 382         memset(&msg, 0, sizeof(msg));
 383         vec.iov_base = &dclc;
 384         vec.iov_len = sizeof(struct smc_clc_msg_decline);
 385         len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
 386                              sizeof(struct smc_clc_msg_decline));
 387         if (len < 0 || len < sizeof(struct smc_clc_msg_decline))
 388                 len = -EPROTO;
 389         return len > 0 ? 0 : len;
 390 }
 391
 392 /* send CLC PROPOSAL message across internal TCP socket */
 393 int smc_clc_send_proposal(struct smc_sock *smc, int smc_type,
 394                           struct smc_init_info *ini)
 395 {
 396         struct smc_clc_ipv6_prefix ipv6_prfx[SMC_CLC_MAX_V6_PREFIX];
 397         struct smc_clc_msg_proposal_prefix pclc_prfx;
 398         struct smc_clc_msg_smcd pclc_smcd;
 399         struct smc_clc_msg_proposal pclc;
 400         struct smc_clc_msg_trail trl;
 401         int len, i, plen, rc;
 402         int reason_code = 0;
 403         struct kvec vec[5];
 404         struct msghdr msg;
 405
 406         /* retrieve ip prefixes for CLC proposal msg */
 407         rc = smc_clc_prfx_set(smc->clcsock, &pclc_prfx, ipv6_prfx);
 408         if (rc)
 409                 return SMC_CLC_DECL_CNFERR; /* configuration error */
 410
 411         /* send SMC Proposal CLC message */
 412         plen = sizeof(pclc) + sizeof(pclc_prfx) +
 413                (pclc_prfx.ipv6_prefixes_cnt * sizeof(ipv6_prfx[0])) +
 414                sizeof(trl);
 415         memset(&pclc, 0, sizeof(pclc));
 416         memcpy(pclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 417         pclc.hdr.type = SMC_CLC_PROPOSAL;
 418         pclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 419         pclc.hdr.path = smc_type;
 420         if (smc_type == SMC_TYPE_R || smc_type == SMC_TYPE_B) {
 421                 /* add SMC-R specifics */
 422                 memcpy(pclc.lcl.id_for_peer, local_systemid,
 423                        sizeof(local_systemid));
 424                 memcpy(&pclc.lcl.gid, ini->ib_gid, SMC_GID_SIZE);
 425                 memcpy(&pclc.lcl.mac, &ini->ib_dev->mac[ini->ib_port - 1],
 426                        ETH_ALEN);
 427                 pclc.iparea_offset = htons(0);
 428         }
 429         if (smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B) {
 430                 /* add SMC-D specifics */
 431                 memset(&pclc_smcd, 0, sizeof(pclc_smcd));
 432                 plen += sizeof(pclc_smcd);
 433                 pclc.iparea_offset = htons(SMC_CLC_PROPOSAL_MAX_OFFSET);
 434                 pclc_smcd.gid = ini->ism_dev->local_gid;
 435         }
 436         pclc.hdr.length = htons(plen);
 437
 438         memcpy(trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 439         memset(&msg, 0, sizeof(msg));
 440         i = 0;
 441         vec[i].iov_base = &pclc;
 442         vec[i++].iov_len = sizeof(pclc);
 443         if (smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B) {
 444                 vec[i].iov_base = &pclc_smcd;
 445                 vec[i++].iov_len = sizeof(pclc_smcd);
 446         }
 447         vec[i].iov_base = &pclc_prfx;
 448         vec[i++].iov_len = sizeof(pclc_prfx);
 449         if (pclc_prfx.ipv6_prefixes_cnt > 0) {
 450                 vec[i].iov_base = &ipv6_prfx[0];
 451                 vec[i++].iov_len = pclc_prfx.ipv6_prefixes_cnt *
 452                                    sizeof(ipv6_prfx[0]);
 453         }
 454         vec[i].iov_base = &trl;
 455         vec[i++].iov_len = sizeof(trl);
 456         /* due to the few bytes needed for clc-handshake this cannot block */
 457         len = kernel_sendmsg(smc->clcsock, &msg, vec, i, plen);
 458         if (len < 0) {
 459                 smc->sk.sk_err = smc->clcsock->sk->sk_err;
 460                 reason_code = -smc->sk.sk_err;
 461         } else if (len < (int)sizeof(pclc)) {
 462                 reason_code = -ENETUNREACH;
 463                 smc->sk.sk_err = -reason_code;
 464         }
 465
 466         return reason_code;
 467 }
 468
 469 /* send CLC CONFIRM message across internal TCP socket */
 470 int smc_clc_send_confirm(struct smc_sock *smc)
 471 {
 472         struct smc_connection *conn = &smc->conn;
 473         struct smc_clc_msg_accept_confirm cclc;
 474         struct smc_link *link;
 475         int reason_code = 0;
 476         struct msghdr msg;
 477         struct kvec vec;
 478         int len;
 479
 480         /* send SMC Confirm CLC msg */
 481         memset(&cclc, 0, sizeof(cclc));
 482         cclc.hdr.type = SMC_CLC_CONFIRM;
 483         cclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 484         if (smc->conn.lgr->is_smcd) {
 485                 /* SMC-D specific settings */
 486                 memcpy(cclc.hdr.eyecatcher, SMCD_EYECATCHER,
 487                        sizeof(SMCD_EYECATCHER));
 488                 cclc.hdr.path = SMC_TYPE_D;
 489                 cclc.hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
 490                 cclc.gid = conn->lgr->smcd->local_gid;
 491                 cclc.token = conn->rmb_desc->token;
 492                 cclc.dmbe_size = conn->rmbe_size_short;
 493                 cclc.dmbe_idx = 0;
 494                 memcpy(&cclc.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
 495                 memcpy(cclc.smcd_trl.eyecatcher, SMCD_EYECATCHER,
 496                        sizeof(SMCD_EYECATCHER));
 497         } else {
 498                 /* SMC-R specific settings */
 499                 link = &conn->lgr->lnk[SMC_SINGLE_LINK];
 500                 memcpy(cclc.hdr.eyecatcher, SMC_EYECATCHER,
 501                        sizeof(SMC_EYECATCHER));
 502                 cclc.hdr.path = SMC_TYPE_R;
 503                 cclc.hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
 504                 memcpy(cclc.lcl.id_for_peer, local_systemid,
 505                        sizeof(local_systemid));
 506                 memcpy(&cclc.lcl.gid, link->gid, SMC_GID_SIZE);
 507                 memcpy(&cclc.lcl.mac, &link->smcibdev->mac[link->ibport - 1],
 508                        ETH_ALEN);
 509                 hton24(cclc.qpn, link->roce_qp->qp_num);
 510                 cclc.rmb_rkey =
 511                         htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
 512                 cclc.rmbe_idx = 1; /* for now: 1 RMB = 1 RMBE */
 513                 cclc.rmbe_alert_token = htonl(conn->alert_token_local);
 514                 cclc.qp_mtu = min(link->path_mtu, link->peer_mtu);
 515                 cclc.rmbe_size = conn->rmbe_size_short;
 516                 cclc.rmb_dma_addr = cpu_to_be64((u64)sg_dma_address
 517                                 (conn->rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
 518                 hton24(cclc.psn, link->psn_initial);
 519                 memcpy(cclc.smcr_trl.eyecatcher, SMC_EYECATCHER,
 520                        sizeof(SMC_EYECATCHER));
 521         }
 522
 523         memset(&msg, 0, sizeof(msg));
 524         vec.iov_base = &cclc;
 525         vec.iov_len = ntohs(cclc.hdr.length);
 526         len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
 527                              ntohs(cclc.hdr.length));
 528         if (len < ntohs(cclc.hdr.length)) {
 529                 if (len >= 0) {
 530                         reason_code = -ENETUNREACH;
 531                         smc->sk.sk_err = -reason_code;
 532                 } else {
 533                         smc->sk.sk_err = smc->clcsock->sk->sk_err;
 534                         reason_code = -smc->sk.sk_err;
 535                 }
 536         }
 537         return reason_code;
 538 }
 539
 540 /* send CLC ACCEPT message across internal TCP socket */
 541 int smc_clc_send_accept(struct smc_sock *new_smc, int srv_first_contact)
 542 {
 543         struct smc_connection *conn = &new_smc->conn;
 544         struct smc_clc_msg_accept_confirm aclc;
 545         struct smc_link *link;
 546         struct msghdr msg;
 547         struct kvec vec;
 548         int len;
 549
 550         memset(&aclc, 0, sizeof(aclc));
 551         aclc.hdr.type = SMC_CLC_ACCEPT;
 552         aclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 553         if (srv_first_contact)
 554                 aclc.hdr.flag = 1;
 555
 556         if (new_smc->conn.lgr->is_smcd) {
 557                 /* SMC-D specific settings */
 558                 aclc.hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
 559                 memcpy(aclc.hdr.eyecatcher, SMCD_EYECATCHER,
 560                        sizeof(SMCD_EYECATCHER));
 561                 aclc.hdr.path = SMC_TYPE_D;
 562                 aclc.gid = conn->lgr->smcd->local_gid;
 563                 aclc.token = conn->rmb_desc->token;
 564                 aclc.dmbe_size = conn->rmbe_size_short;
 565                 aclc.dmbe_idx = 0;
 566                 memcpy(&aclc.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
 567                 memcpy(aclc.smcd_trl.eyecatcher, SMCD_EYECATCHER,
 568                        sizeof(SMCD_EYECATCHER));
 569         } else {
 570                 /* SMC-R specific settings */
 571                 aclc.hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
 572                 memcpy(aclc.hdr.eyecatcher, SMC_EYECATCHER,
 573                        sizeof(SMC_EYECATCHER));
 574                 aclc.hdr.path = SMC_TYPE_R;
 575                 link = &conn->lgr->lnk[SMC_SINGLE_LINK];
 576                 memcpy(aclc.lcl.id_for_peer, local_systemid,
 577                        sizeof(local_systemid));
 578                 memcpy(&aclc.lcl.gid, link->gid, SMC_GID_SIZE);
 579                 memcpy(&aclc.lcl.mac, link->smcibdev->mac[link->ibport - 1],
 580                        ETH_ALEN);
 581                 hton24(aclc.qpn, link->roce_qp->qp_num);
 582                 aclc.rmb_rkey =
 583                         htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
 584                 aclc.rmbe_idx = 1;              /* as long as 1 RMB = 1 RMBE */
 585                 aclc.rmbe_alert_token = htonl(conn->alert_token_local);
 586                 aclc.qp_mtu = link->path_mtu;
 587                 aclc.rmbe_size = conn->rmbe_size_short,
 588                 aclc.rmb_dma_addr = cpu_to_be64((u64)sg_dma_address
 589                                 (conn->rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
 590                 hton24(aclc.psn, link->psn_initial);
 591                 memcpy(aclc.smcr_trl.eyecatcher, SMC_EYECATCHER,
 592                        sizeof(SMC_EYECATCHER));
 593         }
 594
 595         memset(&msg, 0, sizeof(msg));
 596         vec.iov_base = &aclc;
 597         vec.iov_len = ntohs(aclc.hdr.length);
 598         len = kernel_sendmsg(new_smc->clcsock, &msg, &vec, 1,
 599                              ntohs(aclc.hdr.length));
 600         if (len < ntohs(aclc.hdr.length))
 601                 len = len >= 0 ? -EPROTO : -new_smc->clcsock->sk->sk_err;
 602
 603         return len > 0 ? 0 : len;
 604 }