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