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
   9  *
  10  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
  11  */
  12
  13 #include <linux/in.h>
  14 #include <linux/if_ether.h>
  15 #include <linux/sched/signal.h>
  16
  17 #include <net/sock.h>
  18 #include <net/tcp.h>
  19
  20 #include "smc.h"
  21 #include "smc_core.h"
  22 #include "smc_clc.h"
  23 #include "smc_ib.h"
  24
  25 /* check if received message has a correct header length and contains valid
  26  * heading and trailing eyecatchers
  27  */
  28 static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm)
  29 {
  30         struct smc_clc_msg_proposal_prefix *pclc_prfx;
  31         struct smc_clc_msg_accept_confirm *clc;
  32         struct smc_clc_msg_proposal *pclc;
  33         struct smc_clc_msg_decline *dclc;
  34         struct smc_clc_msg_trail *trl;
  35
  36         if (memcmp(clcm->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)))
  37                 return false;
  38         switch (clcm->type) {
  39         case SMC_CLC_PROPOSAL:
  40                 pclc = (struct smc_clc_msg_proposal *)clcm;
  41                 pclc_prfx = smc_clc_proposal_get_prefix(pclc);
  42                 if (ntohs(pclc->hdr.length) !=
  43                         sizeof(*pclc) + ntohs(pclc->iparea_offset) +
  44                         sizeof(*pclc_prfx) +
  45                         pclc_prfx->ipv6_prefixes_cnt *
  46                                 sizeof(struct smc_clc_ipv6_prefix) +
  47                         sizeof(*trl))
  48                         return false;
  49                 trl = (struct smc_clc_msg_trail *)
  50                         ((u8 *)pclc + ntohs(pclc->hdr.length) - sizeof(*trl));
  51                 break;
  52         case SMC_CLC_ACCEPT:
  53         case SMC_CLC_CONFIRM:
  54                 clc = (struct smc_clc_msg_accept_confirm *)clcm;
  55                 if (ntohs(clc->hdr.length) != sizeof(*clc))
  56                         return false;
  57                 trl = &clc->trl;
  58                 break;
  59         case SMC_CLC_DECLINE:
  60                 dclc = (struct smc_clc_msg_decline *)clcm;
  61                 if (ntohs(dclc->hdr.length) != sizeof(*dclc))
  62                         return false;
  63                 trl = &dclc->trl;
  64                 break;
  65         default:
  66                 return false;
  67         }
  68         if (memcmp(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)))
  69                 return false;
  70         return true;
  71 }
  72
  73 /* Wait for data on the tcp-socket, analyze received data
  74  * Returns:
  75  * 0 if success and it was not a decline that we received.
  76  * SMC_CLC_DECL_REPLY if decline received for fallback w/o another decl send.
  77  * clcsock error, -EINTR, -ECONNRESET, -EPROTO otherwise.
  78  */
  79 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
  80                      u8 expected_type)
  81 {
  82         struct sock *clc_sk = smc->clcsock->sk;
  83         struct smc_clc_msg_hdr *clcm = buf;
  84         struct msghdr msg = {NULL, 0};
  85         int reason_code = 0;
  86         struct kvec vec = {buf, buflen};
  87         int len, datlen;
  88         int krflags;
  89
  90         /* peek the first few bytes to determine length of data to receive
  91          * so we don't consume any subsequent CLC message or payload data
  92          * in the TCP byte stream
  93          */
  94         /*
  95          * Caller must make sure that buflen is no less than
  96          * sizeof(struct smc_clc_msg_hdr)
  97          */
  98         krflags = MSG_PEEK | MSG_WAITALL;
  99         smc->clcsock->sk->sk_rcvtimeo = CLC_WAIT_TIME;
 100         iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &vec, 1,
 101                         sizeof(struct smc_clc_msg_hdr));
 102         len = sock_recvmsg(smc->clcsock, &msg, krflags);
 103         if (signal_pending(current)) {
 104                 reason_code = -EINTR;
 105                 clc_sk->sk_err = EINTR;
 106                 smc->sk.sk_err = EINTR;
 107                 goto out;
 108         }
 109         if (clc_sk->sk_err) {
 110                 reason_code = -clc_sk->sk_err;
 111                 smc->sk.sk_err = clc_sk->sk_err;
 112                 goto out;
 113         }
 114         if (!len) { /* peer has performed orderly shutdown */
 115                 smc->sk.sk_err = ECONNRESET;
 116                 reason_code = -ECONNRESET;
 117                 goto out;
 118         }
 119         if (len < 0) {
 120                 smc->sk.sk_err = -len;
 121                 reason_code = len;
 122                 goto out;
 123         }
 124         datlen = ntohs(clcm->length);
 125         if ((len < sizeof(struct smc_clc_msg_hdr)) ||
 126             (datlen > buflen) ||
 127             ((clcm->type != SMC_CLC_DECLINE) &&
 128              (clcm->type != expected_type))) {
 129                 smc->sk.sk_err = EPROTO;
 130                 reason_code = -EPROTO;
 131                 goto out;
 132         }
 133
 134         /* receive the complete CLC message */
 135         memset(&msg, 0, sizeof(struct msghdr));
 136         iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &vec, 1, buflen);
 137         krflags = MSG_WAITALL;
 138         smc->clcsock->sk->sk_rcvtimeo = CLC_WAIT_TIME;
 139         len = sock_recvmsg(smc->clcsock, &msg, krflags);
 140         if (len < datlen || !smc_clc_msg_hdr_valid(clcm)) {
 141                 smc->sk.sk_err = EPROTO;
 142                 reason_code = -EPROTO;
 143                 goto out;
 144         }
 145         if (clcm->type == SMC_CLC_DECLINE) {
 146                 reason_code = SMC_CLC_DECL_REPLY;
 147                 if (((struct smc_clc_msg_decline *)buf)->hdr.flag) {
 148                         smc->conn.lgr->sync_err = true;
 149                         smc_lgr_terminate(smc->conn.lgr);
 150                 }
 151         }
 152
 153 out:
 154         return reason_code;
 155 }
 156
 157 /* send CLC DECLINE message across internal TCP socket */
 158 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info)
 159 {
 160         struct smc_clc_msg_decline dclc;
 161         struct msghdr msg;
 162         struct kvec vec;
 163         int len;
 164
 165         memset(&dclc, 0, sizeof(dclc));
 166         memcpy(dclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 167         dclc.hdr.type = SMC_CLC_DECLINE;
 168         dclc.hdr.length = htons(sizeof(struct smc_clc_msg_decline));
 169         dclc.hdr.version = SMC_CLC_V1;
 170         dclc.hdr.flag = (peer_diag_info == SMC_CLC_DECL_SYNCERR) ? 1 : 0;
 171         memcpy(dclc.id_for_peer, local_systemid, sizeof(local_systemid));
 172         dclc.peer_diagnosis = htonl(peer_diag_info);
 173         memcpy(dclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 174
 175         memset(&msg, 0, sizeof(msg));
 176         vec.iov_base = &dclc;
 177         vec.iov_len = sizeof(struct smc_clc_msg_decline);
 178         len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
 179                              sizeof(struct smc_clc_msg_decline));
 180         if (len < sizeof(struct smc_clc_msg_decline))
 181                 smc->sk.sk_err = EPROTO;
 182         if (len < 0)
 183                 smc->sk.sk_err = -len;
 184         return sock_error(&smc->sk);
 185 }
 186
 187 /* send CLC PROPOSAL message across internal TCP socket */
 188 int smc_clc_send_proposal(struct smc_sock *smc,
 189                           struct smc_ib_device *smcibdev,
 190                           u8 ibport)
 191 {
 192         struct smc_clc_msg_proposal_prefix pclc_prfx;
 193         struct smc_clc_msg_proposal pclc;
 194         struct smc_clc_msg_trail trl;
 195         int reason_code = 0;
 196         struct kvec vec[3];
 197         struct msghdr msg;
 198         int len, plen, rc;
 199
 200         /* send SMC Proposal CLC message */
 201         plen = sizeof(pclc) + sizeof(pclc_prfx) + sizeof(trl);
 202         memset(&pclc, 0, sizeof(pclc));
 203         memcpy(pclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 204         pclc.hdr.type = SMC_CLC_PROPOSAL;
 205         pclc.hdr.length = htons(plen);
 206         pclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 207         memcpy(pclc.lcl.id_for_peer, local_systemid, sizeof(local_systemid));
 208         memcpy(&pclc.lcl.gid, &smcibdev->gid[ibport - 1], SMC_GID_SIZE);
 209         memcpy(&pclc.lcl.mac, &smcibdev->mac[ibport - 1], ETH_ALEN);
 210         pclc.iparea_offset = htons(0);
 211
 212         memset(&pclc_prfx, 0, sizeof(pclc_prfx));
 213         /* determine subnet and mask from internal TCP socket */
 214         rc = smc_netinfo_by_tcpsk(smc->clcsock, &pclc_prfx.outgoing_subnet,
 215                                   &pclc_prfx.prefix_len);
 216         if (rc)
 217                 return SMC_CLC_DECL_CNFERR; /* configuration error */
 218         pclc_prfx.ipv6_prefixes_cnt = 0;
 219         memcpy(trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 220         memset(&msg, 0, sizeof(msg));
 221         vec[0].iov_base = &pclc;
 222         vec[0].iov_len = sizeof(pclc);
 223         vec[1].iov_base = &pclc_prfx;
 224         vec[1].iov_len = sizeof(pclc_prfx);
 225         vec[2].iov_base = &trl;
 226         vec[2].iov_len = sizeof(trl);
 227         /* due to the few bytes needed for clc-handshake this cannot block */
 228         len = kernel_sendmsg(smc->clcsock, &msg, vec, 3, plen);
 229         if (len < sizeof(pclc)) {
 230                 if (len >= 0) {
 231                         reason_code = -ENETUNREACH;
 232                         smc->sk.sk_err = -reason_code;
 233                 } else {
 234                         smc->sk.sk_err = smc->clcsock->sk->sk_err;
 235                         reason_code = -smc->sk.sk_err;
 236                 }
 237         }
 238
 239         return reason_code;
 240 }
 241
 242 /* send CLC CONFIRM message across internal TCP socket */
 243 int smc_clc_send_confirm(struct smc_sock *smc)
 244 {
 245         struct smc_connection *conn = &smc->conn;
 246         struct smc_clc_msg_accept_confirm cclc;
 247         struct smc_link *link;
 248         int reason_code = 0;
 249         struct msghdr msg;
 250         struct kvec vec;
 251         int len;
 252
 253         link = &conn->lgr->lnk[SMC_SINGLE_LINK];
 254         /* send SMC Confirm CLC msg */
 255         memset(&cclc, 0, sizeof(cclc));
 256         memcpy(cclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 257         cclc.hdr.type = SMC_CLC_CONFIRM;
 258         cclc.hdr.length = htons(sizeof(cclc));
 259         cclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 260         memcpy(cclc.lcl.id_for_peer, local_systemid, sizeof(local_systemid));
 261         memcpy(&cclc.lcl.gid, &link->smcibdev->gid[link->ibport - 1],
 262                SMC_GID_SIZE);
 263         memcpy(&cclc.lcl.mac, &link->smcibdev->mac[link->ibport - 1], ETH_ALEN);
 264         hton24(cclc.qpn, link->roce_qp->qp_num);
 265         cclc.rmb_rkey =
 266                 htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
 267         cclc.conn_idx = 1; /* for now: 1 RMB = 1 RMBE */
 268         cclc.rmbe_alert_token = htonl(conn->alert_token_local);
 269         cclc.qp_mtu = min(link->path_mtu, link->peer_mtu);
 270         cclc.rmbe_size = conn->rmbe_size_short;
 271         cclc.rmb_dma_addr = cpu_to_be64(
 272                 (u64)sg_dma_address(conn->rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
 273         hton24(cclc.psn, link->psn_initial);
 274
 275         memcpy(cclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 276
 277         memset(&msg, 0, sizeof(msg));
 278         vec.iov_base = &cclc;
 279         vec.iov_len = sizeof(cclc);
 280         len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1, sizeof(cclc));
 281         if (len < sizeof(cclc)) {
 282                 if (len >= 0) {
 283                         reason_code = -ENETUNREACH;
 284                         smc->sk.sk_err = -reason_code;
 285                 } else {
 286                         smc->sk.sk_err = smc->clcsock->sk->sk_err;
 287                         reason_code = -smc->sk.sk_err;
 288                 }
 289         }
 290         return reason_code;
 291 }
 292
 293 /* send CLC ACCEPT message across internal TCP socket */
 294 int smc_clc_send_accept(struct smc_sock *new_smc, int srv_first_contact)
 295 {
 296         struct smc_connection *conn = &new_smc->conn;
 297         struct smc_clc_msg_accept_confirm aclc;
 298         struct smc_link *link;
 299         struct msghdr msg;
 300         struct kvec vec;
 301         int rc = 0;
 302         int len;
 303
 304         link = &conn->lgr->lnk[SMC_SINGLE_LINK];
 305         memset(&aclc, 0, sizeof(aclc));
 306         memcpy(aclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 307         aclc.hdr.type = SMC_CLC_ACCEPT;
 308         aclc.hdr.length = htons(sizeof(aclc));
 309         aclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 310         if (srv_first_contact)
 311                 aclc.hdr.flag = 1;
 312         memcpy(aclc.lcl.id_for_peer, local_systemid, sizeof(local_systemid));
 313         memcpy(&aclc.lcl.gid, &link->smcibdev->gid[link->ibport - 1],
 314                SMC_GID_SIZE);
 315         memcpy(&aclc.lcl.mac, link->smcibdev->mac[link->ibport - 1], ETH_ALEN);
 316         hton24(aclc.qpn, link->roce_qp->qp_num);
 317         aclc.rmb_rkey =
 318                 htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
 319         aclc.conn_idx = 1;                      /* as long as 1 RMB = 1 RMBE */
 320         aclc.rmbe_alert_token = htonl(conn->alert_token_local);
 321         aclc.qp_mtu = link->path_mtu;
 322         aclc.rmbe_size = conn->rmbe_size_short,
 323         aclc.rmb_dma_addr = cpu_to_be64(
 324                 (u64)sg_dma_address(conn->rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
 325         hton24(aclc.psn, link->psn_initial);
 326         memcpy(aclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 327
 328         memset(&msg, 0, sizeof(msg));
 329         vec.iov_base = &aclc;
 330         vec.iov_len = sizeof(aclc);
 331         len = kernel_sendmsg(new_smc->clcsock, &msg, &vec, 1, sizeof(aclc));
 332         if (len < sizeof(aclc)) {
 333                 if (len >= 0)
 334                         new_smc->sk.sk_err = EPROTO;
 335                 else
 336                         new_smc->sk.sk_err = new_smc->clcsock->sk->sk_err;
 337                 rc = sock_error(&new_smc->sk);
 338         }
 339
 340         return rc;
 341 }