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 #define SMC_CLC_RECV_BUF_LEN    100
  31
  32 /* eye catcher "SMCR" EBCDIC for CLC messages */
  33 static const char SMC_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xd9'};
  34 /* eye catcher "SMCD" EBCDIC for CLC messages */
  35 static const char SMCD_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xc4'};
  36
  37 /* check if received message has a correct header length and contains valid
  38  * heading and trailing eyecatchers
  39  */
  40 static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm, bool check_trl)
  41 {
  42         struct smc_clc_msg_proposal_prefix *pclc_prfx;
  43         struct smc_clc_msg_accept_confirm *clc;
  44         struct smc_clc_msg_proposal *pclc;
  45         struct smc_clc_msg_decline *dclc;
  46         struct smc_clc_msg_trail *trl;
  47
  48         if (memcmp(clcm->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
  49             memcmp(clcm->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
  50                 return false;
  51         switch (clcm->type) {
  52         case SMC_CLC_PROPOSAL:
  53                 pclc = (struct smc_clc_msg_proposal *)clcm;
  54                 pclc_prfx = smc_clc_proposal_get_prefix(pclc);
  55                 if (ntohs(pclc->hdr.length) <
  56                         sizeof(*pclc) + ntohs(pclc->iparea_offset) +
  57                         sizeof(*pclc_prfx) +
  58                         pclc_prfx->ipv6_prefixes_cnt *
  59                                 sizeof(struct smc_clc_ipv6_prefix) +
  60                         sizeof(*trl))
  61                         return false;
  62                 trl = (struct smc_clc_msg_trail *)
  63                         ((u8 *)pclc + ntohs(pclc->hdr.length) - sizeof(*trl));
  64                 break;
  65         case SMC_CLC_ACCEPT:
  66         case SMC_CLC_CONFIRM:
  67                 if (clcm->path != SMC_TYPE_R && clcm->path != SMC_TYPE_D)
  68                         return false;
  69                 clc = (struct smc_clc_msg_accept_confirm *)clcm;
  70                 if ((clcm->path == SMC_TYPE_R &&
  71                      ntohs(clc->hdr.length) != SMCR_CLC_ACCEPT_CONFIRM_LEN) ||
  72                     (clcm->path == SMC_TYPE_D &&
  73                      ntohs(clc->hdr.length) != SMCD_CLC_ACCEPT_CONFIRM_LEN))
  74                         return false;
  75                 trl = (struct smc_clc_msg_trail *)
  76                         ((u8 *)clc + ntohs(clc->hdr.length) - sizeof(*trl));
  77                 break;
  78         case SMC_CLC_DECLINE:
  79                 dclc = (struct smc_clc_msg_decline *)clcm;
  80                 if (ntohs(dclc->hdr.length) != sizeof(*dclc))
  81                         return false;
  82                 trl = &dclc->trl;
  83                 break;
  84         default:
  85                 return false;
  86         }
  87         if (check_trl &&
  88             memcmp(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
  89             memcmp(trl->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
  90                 return false;
  91         return true;
  92 }
  93
  94 /* find ipv4 addr on device and get the prefix len, fill CLC proposal msg */
  95 static int smc_clc_prfx_set4_rcu(struct dst_entry *dst, __be32 ipv4,
  96                                  struct smc_clc_msg_proposal_prefix *prop)
  97 {
  98         struct in_device *in_dev = __in_dev_get_rcu(dst->dev);
  99         const struct in_ifaddr *ifa;
 100
 101         if (!in_dev)
 102                 return -ENODEV;
 103
 104         in_dev_for_each_ifa_rcu(ifa, in_dev) {
 105                 if (!inet_ifa_match(ipv4, ifa))
 106                         continue;
 107                 prop->prefix_len = inet_mask_len(ifa->ifa_mask);
 108                 prop->outgoing_subnet = ifa->ifa_address & ifa->ifa_mask;
 109                 /* prop->ipv6_prefixes_cnt = 0; already done by memset before */
 110                 return 0;
 111         }
 112         return -ENOENT;
 113 }
 114
 115 /* fill CLC proposal msg with ipv6 prefixes from device */
 116 static int smc_clc_prfx_set6_rcu(struct dst_entry *dst,
 117                                  struct smc_clc_msg_proposal_prefix *prop,
 118                                  struct smc_clc_ipv6_prefix *ipv6_prfx)
 119 {
 120 #if IS_ENABLED(CONFIG_IPV6)
 121         struct inet6_dev *in6_dev = __in6_dev_get(dst->dev);
 122         struct inet6_ifaddr *ifa;
 123         int cnt = 0;
 124
 125         if (!in6_dev)
 126                 return -ENODEV;
 127         /* use a maximum of 8 IPv6 prefixes from device */
 128         list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
 129                 if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
 130                         continue;
 131                 ipv6_addr_prefix(&ipv6_prfx[cnt].prefix,
 132                                  &ifa->addr, ifa->prefix_len);
 133                 ipv6_prfx[cnt].prefix_len = ifa->prefix_len;
 134                 cnt++;
 135                 if (cnt == SMC_CLC_MAX_V6_PREFIX)
 136                         break;
 137         }
 138         prop->ipv6_prefixes_cnt = cnt;
 139         if (cnt)
 140                 return 0;
 141 #endif
 142         return -ENOENT;
 143 }
 144
 145 /* retrieve and set prefixes in CLC proposal msg */
 146 static int smc_clc_prfx_set(struct socket *clcsock,
 147                             struct smc_clc_msg_proposal_prefix *prop,
 148                             struct smc_clc_ipv6_prefix *ipv6_prfx)
 149 {
 150         struct dst_entry *dst = sk_dst_get(clcsock->sk);
 151         struct sockaddr_storage addrs;
 152         struct sockaddr_in6 *addr6;
 153         struct sockaddr_in *addr;
 154         int rc = -ENOENT;
 155
 156         memset(prop, 0, sizeof(*prop));
 157         if (!dst) {
 158                 rc = -ENOTCONN;
 159                 goto out;
 160         }
 161         if (!dst->dev) {
 162                 rc = -ENODEV;
 163                 goto out_rel;
 164         }
 165         /* get address to which the internal TCP socket is bound */
 166         kernel_getsockname(clcsock, (struct sockaddr *)&addrs);
 167         /* analyze IP specific data of net_device belonging to TCP socket */
 168         addr6 = (struct sockaddr_in6 *)&addrs;
 169         rcu_read_lock();
 170         if (addrs.ss_family == PF_INET) {
 171                 /* IPv4 */
 172                 addr = (struct sockaddr_in *)&addrs;
 173                 rc = smc_clc_prfx_set4_rcu(dst, addr->sin_addr.s_addr, prop);
 174         } else if (ipv6_addr_v4mapped(&addr6->sin6_addr)) {
 175                 /* mapped IPv4 address - peer is IPv4 only */
 176                 rc = smc_clc_prfx_set4_rcu(dst, addr6->sin6_addr.s6_addr32[3],
 177                                            prop);
 178         } else {
 179                 /* IPv6 */
 180                 rc = smc_clc_prfx_set6_rcu(dst, prop, ipv6_prfx);
 181         }
 182         rcu_read_unlock();
 183 out_rel:
 184         dst_release(dst);
 185 out:
 186         return rc;
 187 }
 188
 189 /* match ipv4 addrs of dev against addr in CLC proposal */
 190 static int smc_clc_prfx_match4_rcu(struct net_device *dev,
 191                                    struct smc_clc_msg_proposal_prefix *prop)
 192 {
 193         struct in_device *in_dev = __in_dev_get_rcu(dev);
 194         const struct in_ifaddr *ifa;
 195
 196         if (!in_dev)
 197                 return -ENODEV;
 198         in_dev_for_each_ifa_rcu(ifa, in_dev) {
 199                 if (prop->prefix_len == inet_mask_len(ifa->ifa_mask) &&
 200                     inet_ifa_match(prop->outgoing_subnet, ifa))
 201                         return 0;
 202         }
 203
 204         return -ENOENT;
 205 }
 206
 207 /* match ipv6 addrs of dev against addrs in CLC proposal */
 208 static int smc_clc_prfx_match6_rcu(struct net_device *dev,
 209                                    struct smc_clc_msg_proposal_prefix *prop)
 210 {
 211 #if IS_ENABLED(CONFIG_IPV6)
 212         struct inet6_dev *in6_dev = __in6_dev_get(dev);
 213         struct smc_clc_ipv6_prefix *ipv6_prfx;
 214         struct inet6_ifaddr *ifa;
 215         int i, max;
 216
 217         if (!in6_dev)
 218                 return -ENODEV;
 219         /* ipv6 prefix list starts behind smc_clc_msg_proposal_prefix */
 220         ipv6_prfx = (struct smc_clc_ipv6_prefix *)((u8 *)prop + sizeof(*prop));
 221         max = min_t(u8, prop->ipv6_prefixes_cnt, SMC_CLC_MAX_V6_PREFIX);
 222         list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
 223                 if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
 224                         continue;
 225                 for (i = 0; i < max; i++) {
 226                         if (ifa->prefix_len == ipv6_prfx[i].prefix_len &&
 227                             ipv6_prefix_equal(&ifa->addr, &ipv6_prfx[i].prefix,
 228                                               ifa->prefix_len))
 229                                 return 0;
 230                 }
 231         }
 232 #endif
 233         return -ENOENT;
 234 }
 235
 236 /* check if proposed prefixes match one of our device prefixes */
 237 int smc_clc_prfx_match(struct socket *clcsock,
 238                        struct smc_clc_msg_proposal_prefix *prop)
 239 {
 240         struct dst_entry *dst = sk_dst_get(clcsock->sk);
 241         int rc;
 242
 243         if (!dst) {
 244                 rc = -ENOTCONN;
 245                 goto out;
 246         }
 247         if (!dst->dev) {
 248                 rc = -ENODEV;
 249                 goto out_rel;
 250         }
 251         rcu_read_lock();
 252         if (!prop->ipv6_prefixes_cnt)
 253                 rc = smc_clc_prfx_match4_rcu(dst->dev, prop);
 254         else
 255                 rc = smc_clc_prfx_match6_rcu(dst->dev, prop);
 256         rcu_read_unlock();
 257 out_rel:
 258         dst_release(dst);
 259 out:
 260         return rc;
 261 }
 262
 263 /* Wait for data on the tcp-socket, analyze received data
 264  * Returns:
 265  * 0 if success and it was not a decline that we received.
 266  * SMC_CLC_DECL_REPLY if decline received for fallback w/o another decl send.
 267  * clcsock error, -EINTR, -ECONNRESET, -EPROTO otherwise.
 268  */
 269 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 270                      u8 expected_type, unsigned long timeout)
 271 {
 272         long rcvtimeo = smc->clcsock->sk->sk_rcvtimeo;
 273         struct sock *clc_sk = smc->clcsock->sk;
 274         struct smc_clc_msg_hdr *clcm = buf;
 275         struct msghdr msg = {NULL, 0};
 276         int reason_code = 0;
 277         struct kvec vec = {buf, buflen};
 278         int len, datlen, recvlen;
 279         bool check_trl = true;
 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             (clcm->version < SMC_CLC_V1) ||
 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         if (clcm->type == SMC_CLC_PROPOSAL && clcm->path == SMC_TYPE_N)
 332                 reason_code = SMC_CLC_DECL_VERSMISMAT; /* just V2 offered */
 333
 334         /* receive the complete CLC message */
 335         memset(&msg, 0, sizeof(struct msghdr));
 336         if (datlen > buflen) {
 337                 check_trl = false;
 338                 recvlen = buflen;
 339         } else {
 340                 recvlen = datlen;
 341         }
 342         iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, recvlen);
 343         krflags = MSG_WAITALL;
 344         len = sock_recvmsg(smc->clcsock, &msg, krflags);
 345         if (len < recvlen || !smc_clc_msg_hdr_valid(clcm, check_trl)) {
 346                 smc->sk.sk_err = EPROTO;
 347                 reason_code = -EPROTO;
 348                 goto out;
 349         }
 350         datlen -= len;
 351         while (datlen) {
 352                 u8 tmp[SMC_CLC_RECV_BUF_LEN];
 353
 354                 vec.iov_base = &tmp;
 355                 vec.iov_len = SMC_CLC_RECV_BUF_LEN;
 356                 /* receive remaining proposal message */
 357                 recvlen = datlen > SMC_CLC_RECV_BUF_LEN ?
 358                                                 SMC_CLC_RECV_BUF_LEN : datlen;
 359                 iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, recvlen);
 360                 len = sock_recvmsg(smc->clcsock, &msg, krflags);
 361                 datlen -= len;
 362         }
 363         if (clcm->type == SMC_CLC_DECLINE) {
 364                 struct smc_clc_msg_decline *dclc;
 365
 366                 dclc = (struct smc_clc_msg_decline *)clcm;
 367                 reason_code = SMC_CLC_DECL_PEERDECL;
 368                 smc->peer_diagnosis = ntohl(dclc->peer_diagnosis);
 369                 if (((struct smc_clc_msg_decline *)buf)->hdr.flag) {
 370                         smc->conn.lgr->sync_err = 1;
 371                         smc_lgr_terminate_sched(smc->conn.lgr);
 372                 }
 373         }
 374
 375 out:
 376         clc_sk->sk_rcvtimeo = rcvtimeo;
 377         return reason_code;
 378 }
 379
 380 /* send CLC DECLINE message across internal TCP socket */
 381 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info)
 382 {
 383         struct smc_clc_msg_decline dclc;
 384         struct msghdr msg;
 385         struct kvec vec;
 386         int len;
 387
 388         memset(&dclc, 0, sizeof(dclc));
 389         memcpy(dclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 390         dclc.hdr.type = SMC_CLC_DECLINE;
 391         dclc.hdr.length = htons(sizeof(struct smc_clc_msg_decline));
 392         dclc.hdr.version = SMC_CLC_V1;
 393         dclc.hdr.flag = (peer_diag_info == SMC_CLC_DECL_SYNCERR) ? 1 : 0;
 394         if ((!smc->conn.lgr || !smc->conn.lgr->is_smcd) &&
 395             smc_ib_is_valid_local_systemid())
 396                 memcpy(dclc.id_for_peer, local_systemid,
 397                        sizeof(local_systemid));
 398         dclc.peer_diagnosis = htonl(peer_diag_info);
 399         memcpy(dclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 400
 401         memset(&msg, 0, sizeof(msg));
 402         vec.iov_base = &dclc;
 403         vec.iov_len = sizeof(struct smc_clc_msg_decline);
 404         len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
 405                              sizeof(struct smc_clc_msg_decline));
 406         if (len < 0 || len < sizeof(struct smc_clc_msg_decline))
 407                 len = -EPROTO;
 408         return len > 0 ? 0 : len;
 409 }
 410
 411 /* send CLC PROPOSAL message across internal TCP socket */
 412 int smc_clc_send_proposal(struct smc_sock *smc, int smc_type,
 413                           struct smc_init_info *ini)
 414 {
 415         struct smc_clc_ipv6_prefix ipv6_prfx[SMC_CLC_MAX_V6_PREFIX];
 416         struct smc_clc_msg_proposal_prefix pclc_prfx;
 417         struct smc_clc_msg_smcd pclc_smcd;
 418         struct smc_clc_msg_proposal pclc;
 419         struct smc_clc_msg_trail trl;
 420         int len, i, plen, rc;
 421         int reason_code = 0;
 422         struct kvec vec[5];
 423         struct msghdr msg;
 424
 425         /* retrieve ip prefixes for CLC proposal msg */
 426         rc = smc_clc_prfx_set(smc->clcsock, &pclc_prfx, ipv6_prfx);
 427         if (rc)
 428                 return SMC_CLC_DECL_CNFERR; /* configuration error */
 429
 430         /* send SMC Proposal CLC message */
 431         plen = sizeof(pclc) + sizeof(pclc_prfx) +
 432                (pclc_prfx.ipv6_prefixes_cnt * sizeof(ipv6_prfx[0])) +
 433                sizeof(trl);
 434         memset(&pclc, 0, sizeof(pclc));
 435         memcpy(pclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 436         pclc.hdr.type = SMC_CLC_PROPOSAL;
 437         pclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 438         pclc.hdr.path = smc_type;
 439         if (smc_type == SMC_TYPE_R || smc_type == SMC_TYPE_B) {
 440                 /* add SMC-R specifics */
 441                 memcpy(pclc.lcl.id_for_peer, local_systemid,
 442                        sizeof(local_systemid));
 443                 memcpy(&pclc.lcl.gid, ini->ib_gid, SMC_GID_SIZE);
 444                 memcpy(&pclc.lcl.mac, &ini->ib_dev->mac[ini->ib_port - 1],
 445                        ETH_ALEN);
 446                 pclc.iparea_offset = htons(0);
 447         }
 448         if (smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B) {
 449                 /* add SMC-D specifics */
 450                 memset(&pclc_smcd, 0, sizeof(pclc_smcd));
 451                 plen += sizeof(pclc_smcd);
 452                 pclc.iparea_offset = htons(SMC_CLC_PROPOSAL_MAX_OFFSET);
 453                 pclc_smcd.gid = ini->ism_dev->local_gid;
 454         }
 455         pclc.hdr.length = htons(plen);
 456
 457         memcpy(trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 458         memset(&msg, 0, sizeof(msg));
 459         i = 0;
 460         vec[i].iov_base = &pclc;
 461         vec[i++].iov_len = sizeof(pclc);
 462         if (smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B) {
 463                 vec[i].iov_base = &pclc_smcd;
 464                 vec[i++].iov_len = sizeof(pclc_smcd);
 465         }
 466         vec[i].iov_base = &pclc_prfx;
 467         vec[i++].iov_len = sizeof(pclc_prfx);
 468         if (pclc_prfx.ipv6_prefixes_cnt > 0) {
 469                 vec[i].iov_base = &ipv6_prfx[0];
 470                 vec[i++].iov_len = pclc_prfx.ipv6_prefixes_cnt *
 471                                    sizeof(ipv6_prfx[0]);
 472         }
 473         vec[i].iov_base = &trl;
 474         vec[i++].iov_len = sizeof(trl);
 475         /* due to the few bytes needed for clc-handshake this cannot block */
 476         len = kernel_sendmsg(smc->clcsock, &msg, vec, i, plen);
 477         if (len < 0) {
 478                 smc->sk.sk_err = smc->clcsock->sk->sk_err;
 479                 reason_code = -smc->sk.sk_err;
 480         } else if (len < (int)sizeof(pclc)) {
 481                 reason_code = -ENETUNREACH;
 482                 smc->sk.sk_err = -reason_code;
 483         }
 484
 485         return reason_code;
 486 }
 487
 488 /* send CLC CONFIRM message across internal TCP socket */
 489 int smc_clc_send_confirm(struct smc_sock *smc)
 490 {
 491         struct smc_connection *conn = &smc->conn;
 492         struct smc_clc_msg_accept_confirm cclc;
 493         struct smc_link *link;
 494         int reason_code = 0;
 495         struct msghdr msg;
 496         struct kvec vec;
 497         int len;
 498
 499         /* send SMC Confirm CLC msg */
 500         memset(&cclc, 0, sizeof(cclc));
 501         cclc.hdr.type = SMC_CLC_CONFIRM;
 502         cclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 503         if (smc->conn.lgr->is_smcd) {
 504                 /* SMC-D specific settings */
 505                 memcpy(cclc.hdr.eyecatcher, SMCD_EYECATCHER,
 506                        sizeof(SMCD_EYECATCHER));
 507                 cclc.hdr.path = SMC_TYPE_D;
 508                 cclc.hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
 509                 cclc.gid = conn->lgr->smcd->local_gid;
 510                 cclc.token = conn->rmb_desc->token;
 511                 cclc.dmbe_size = conn->rmbe_size_short;
 512                 cclc.dmbe_idx = 0;
 513                 memcpy(&cclc.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
 514                 memcpy(cclc.smcd_trl.eyecatcher, SMCD_EYECATCHER,
 515                        sizeof(SMCD_EYECATCHER));
 516         } else {
 517                 /* SMC-R specific settings */
 518                 link = conn->lnk;
 519                 memcpy(cclc.hdr.eyecatcher, SMC_EYECATCHER,
 520                        sizeof(SMC_EYECATCHER));
 521                 cclc.hdr.path = SMC_TYPE_R;
 522                 cclc.hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
 523                 memcpy(cclc.lcl.id_for_peer, local_systemid,
 524                        sizeof(local_systemid));
 525                 memcpy(&cclc.lcl.gid, link->gid, SMC_GID_SIZE);
 526                 memcpy(&cclc.lcl.mac, &link->smcibdev->mac[link->ibport - 1],
 527                        ETH_ALEN);
 528                 hton24(cclc.qpn, link->roce_qp->qp_num);
 529                 cclc.rmb_rkey =
 530                         htonl(conn->rmb_desc->mr_rx[link->link_idx]->rkey);
 531                 cclc.rmbe_idx = 1; /* for now: 1 RMB = 1 RMBE */
 532                 cclc.rmbe_alert_token = htonl(conn->alert_token_local);
 533                 cclc.qp_mtu = min(link->path_mtu, link->peer_mtu);
 534                 cclc.rmbe_size = conn->rmbe_size_short;
 535                 cclc.rmb_dma_addr = cpu_to_be64((u64)sg_dma_address
 536                                 (conn->rmb_desc->sgt[link->link_idx].sgl));
 537                 hton24(cclc.psn, link->psn_initial);
 538                 memcpy(cclc.smcr_trl.eyecatcher, SMC_EYECATCHER,
 539                        sizeof(SMC_EYECATCHER));
 540         }
 541
 542         memset(&msg, 0, sizeof(msg));
 543         vec.iov_base = &cclc;
 544         vec.iov_len = ntohs(cclc.hdr.length);
 545         len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
 546                              ntohs(cclc.hdr.length));
 547         if (len < ntohs(cclc.hdr.length)) {
 548                 if (len >= 0) {
 549                         reason_code = -ENETUNREACH;
 550                         smc->sk.sk_err = -reason_code;
 551                 } else {
 552                         smc->sk.sk_err = smc->clcsock->sk->sk_err;
 553                         reason_code = -smc->sk.sk_err;
 554                 }
 555         }
 556         return reason_code;
 557 }
 558
 559 /* send CLC ACCEPT message across internal TCP socket */
 560 int smc_clc_send_accept(struct smc_sock *new_smc, int srv_first_contact)
 561 {
 562         struct smc_connection *conn = &new_smc->conn;
 563         struct smc_clc_msg_accept_confirm aclc;
 564         struct smc_link *link;
 565         struct msghdr msg;
 566         struct kvec vec;
 567         int len;
 568
 569         memset(&aclc, 0, sizeof(aclc));
 570         aclc.hdr.type = SMC_CLC_ACCEPT;
 571         aclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 572         if (srv_first_contact)
 573                 aclc.hdr.flag = 1;
 574
 575         if (new_smc->conn.lgr->is_smcd) {
 576                 /* SMC-D specific settings */
 577                 aclc.hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
 578                 memcpy(aclc.hdr.eyecatcher, SMCD_EYECATCHER,
 579                        sizeof(SMCD_EYECATCHER));
 580                 aclc.hdr.path = SMC_TYPE_D;
 581                 aclc.gid = conn->lgr->smcd->local_gid;
 582                 aclc.token = conn->rmb_desc->token;
 583                 aclc.dmbe_size = conn->rmbe_size_short;
 584                 aclc.dmbe_idx = 0;
 585                 memcpy(&aclc.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
 586                 memcpy(aclc.smcd_trl.eyecatcher, SMCD_EYECATCHER,
 587                        sizeof(SMCD_EYECATCHER));
 588         } else {
 589                 /* SMC-R specific settings */
 590                 aclc.hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
 591                 memcpy(aclc.hdr.eyecatcher, SMC_EYECATCHER,
 592                        sizeof(SMC_EYECATCHER));
 593                 aclc.hdr.path = SMC_TYPE_R;
 594                 link = conn->lnk;
 595                 memcpy(aclc.lcl.id_for_peer, local_systemid,
 596                        sizeof(local_systemid));
 597                 memcpy(&aclc.lcl.gid, link->gid, SMC_GID_SIZE);
 598                 memcpy(&aclc.lcl.mac, link->smcibdev->mac[link->ibport - 1],
 599                        ETH_ALEN);
 600                 hton24(aclc.qpn, link->roce_qp->qp_num);
 601                 aclc.rmb_rkey =
 602                         htonl(conn->rmb_desc->mr_rx[link->link_idx]->rkey);
 603                 aclc.rmbe_idx = 1;              /* as long as 1 RMB = 1 RMBE */
 604                 aclc.rmbe_alert_token = htonl(conn->alert_token_local);
 605                 aclc.qp_mtu = link->path_mtu;
 606                 aclc.rmbe_size = conn->rmbe_size_short,
 607                 aclc.rmb_dma_addr = cpu_to_be64((u64)sg_dma_address
 608                                 (conn->rmb_desc->sgt[link->link_idx].sgl));
 609                 hton24(aclc.psn, link->psn_initial);
 610                 memcpy(aclc.smcr_trl.eyecatcher, SMC_EYECATCHER,
 611                        sizeof(SMC_EYECATCHER));
 612         }
 613
 614         memset(&msg, 0, sizeof(msg));
 615         vec.iov_base = &aclc;
 616         vec.iov_len = ntohs(aclc.hdr.length);
 617         len = kernel_sendmsg(new_smc->clcsock, &msg, &vec, 1,
 618                              ntohs(aclc.hdr.length));
 619         if (len < ntohs(aclc.hdr.length))
 620                 len = len >= 0 ? -EPROTO : -new_smc->clcsock->sk->sk_err;
 621
 622         return len > 0 ? 0 : len;
 623 }