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 /* Wait for data on the tcp-socket, analyze received data
  26  * Returns:
  27  * 0 if success and it was not a decline that we received.
  28  * SMC_CLC_DECL_REPLY if decline received for fallback w/o another decl send.
  29  * clcsock error, -EINTR, -ECONNRESET, -EPROTO otherwise.
  30  */
  31 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
  32                      u8 expected_type)
  33 {
  34         struct sock *clc_sk = smc->clcsock->sk;
  35         struct smc_clc_msg_hdr *clcm = buf;
  36         struct msghdr msg = {NULL, 0};
  37         int reason_code = 0;
  38         struct kvec vec;
  39         int len, datlen;
  40         int krflags;
  41
  42         /* peek the first few bytes to determine length of data to receive
  43          * so we don't consume any subsequent CLC message or payload data
  44          * in the TCP byte stream
  45          */
  46         vec.iov_base = buf;
  47         vec.iov_len = buflen;
  48         krflags = MSG_PEEK | MSG_WAITALL;
  49         smc->clcsock->sk->sk_rcvtimeo = CLC_WAIT_TIME;
  50         len = kernel_recvmsg(smc->clcsock, &msg, &vec, 1,
  51                              sizeof(struct smc_clc_msg_hdr), krflags);
  52         if (signal_pending(current)) {
  53                 reason_code = -EINTR;
  54                 clc_sk->sk_err = EINTR;
  55                 smc->sk.sk_err = EINTR;
  56                 goto out;
  57         }
  58         if (clc_sk->sk_err) {
  59                 reason_code = -clc_sk->sk_err;
  60                 smc->sk.sk_err = clc_sk->sk_err;
  61                 goto out;
  62         }
  63         if (!len) { /* peer has performed orderly shutdown */
  64                 smc->sk.sk_err = ECONNRESET;
  65                 reason_code = -ECONNRESET;
  66                 goto out;
  67         }
  68         if (len < 0) {
  69                 smc->sk.sk_err = -len;
  70                 reason_code = len;
  71                 goto out;
  72         }
  73         datlen = ntohs(clcm->length);
  74         if ((len < sizeof(struct smc_clc_msg_hdr)) ||
  75             (datlen < sizeof(struct smc_clc_msg_decline)) ||
  76             (datlen > sizeof(struct smc_clc_msg_accept_confirm)) ||
  77             memcmp(clcm->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) ||
  78             ((clcm->type != SMC_CLC_DECLINE) &&
  79              (clcm->type != expected_type))) {
  80                 smc->sk.sk_err = EPROTO;
  81                 reason_code = -EPROTO;
  82                 goto out;
  83         }
  84
  85         /* receive the complete CLC message */
  86         vec.iov_base = buf;
  87         vec.iov_len = buflen;
  88         memset(&msg, 0, sizeof(struct msghdr));
  89         krflags = MSG_WAITALL;
  90         smc->clcsock->sk->sk_rcvtimeo = CLC_WAIT_TIME;
  91         len = kernel_recvmsg(smc->clcsock, &msg, &vec, 1, datlen, krflags);
  92         if (len < datlen) {
  93                 smc->sk.sk_err = EPROTO;
  94                 reason_code = -EPROTO;
  95                 goto out;
  96         }
  97         if (clcm->type == SMC_CLC_DECLINE) {
  98                 reason_code = SMC_CLC_DECL_REPLY;
  99                 if (((struct smc_clc_msg_decline *)buf)->hdr.flag) {
 100                         smc->conn.lgr->sync_err = true;
 101                         smc_lgr_terminate(smc->conn.lgr);
 102                 }
 103         }
 104
 105 out:
 106         return reason_code;
 107 }
 108
 109 /* send CLC DECLINE message across internal TCP socket */
 110 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info)
 111 {
 112         struct smc_clc_msg_decline dclc;
 113         struct msghdr msg;
 114         struct kvec vec;
 115         int len;
 116
 117         memset(&dclc, 0, sizeof(dclc));
 118         memcpy(dclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 119         dclc.hdr.type = SMC_CLC_DECLINE;
 120         dclc.hdr.length = htons(sizeof(struct smc_clc_msg_decline));
 121         dclc.hdr.version = SMC_CLC_V1;
 122         dclc.hdr.flag = (peer_diag_info == SMC_CLC_DECL_SYNCERR) ? 1 : 0;
 123         memcpy(dclc.id_for_peer, local_systemid, sizeof(local_systemid));
 124         dclc.peer_diagnosis = htonl(peer_diag_info);
 125         memcpy(dclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 126
 127         memset(&msg, 0, sizeof(msg));
 128         vec.iov_base = &dclc;
 129         vec.iov_len = sizeof(struct smc_clc_msg_decline);
 130         len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
 131                              sizeof(struct smc_clc_msg_decline));
 132         if (len < sizeof(struct smc_clc_msg_decline))
 133                 smc->sk.sk_err = EPROTO;
 134         if (len < 0)
 135                 smc->sk.sk_err = -len;
 136         return len;
 137 }
 138
 139 /* send CLC PROPOSAL message across internal TCP socket */
 140 int smc_clc_send_proposal(struct smc_sock *smc,
 141                           struct smc_ib_device *smcibdev,
 142                           u8 ibport)
 143 {
 144         struct smc_clc_msg_proposal pclc;
 145         int reason_code = 0;
 146         struct msghdr msg;
 147         struct kvec vec;
 148         int len, rc;
 149
 150         /* send SMC Proposal CLC message */
 151         memset(&pclc, 0, sizeof(pclc));
 152         memcpy(pclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 153         pclc.hdr.type = SMC_CLC_PROPOSAL;
 154         pclc.hdr.length = htons(sizeof(pclc));
 155         pclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 156         memcpy(pclc.lcl.id_for_peer, local_systemid, sizeof(local_systemid));
 157         memcpy(&pclc.lcl.gid, &smcibdev->gid[ibport - 1], SMC_GID_SIZE);
 158         memcpy(&pclc.lcl.mac, &smcibdev->mac[ibport - 1], ETH_ALEN);
 159
 160         /* determine subnet and mask from internal TCP socket */
 161         rc = smc_netinfo_by_tcpsk(smc->clcsock, &pclc.outgoing_subnet,
 162                                   &pclc.prefix_len);
 163         if (rc)
 164                 return SMC_CLC_DECL_CNFERR; /* configuration error */
 165         memcpy(pclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 166         memset(&msg, 0, sizeof(msg));
 167         vec.iov_base = &pclc;
 168         vec.iov_len = sizeof(pclc);
 169         /* due to the few bytes needed for clc-handshake this cannot block */
 170         len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1, sizeof(pclc));
 171         if (len < sizeof(pclc)) {
 172                 if (len >= 0) {
 173                         reason_code = -ENETUNREACH;
 174                         smc->sk.sk_err = -reason_code;
 175                 } else {
 176                         smc->sk.sk_err = smc->clcsock->sk->sk_err;
 177                         reason_code = -smc->sk.sk_err;
 178                 }
 179         }
 180
 181         return reason_code;
 182 }
 183
 184 /* send CLC CONFIRM message across internal TCP socket */
 185 int smc_clc_send_confirm(struct smc_sock *smc)
 186 {
 187         struct smc_connection *conn = &smc->conn;
 188         struct smc_clc_msg_accept_confirm cclc;
 189         struct smc_link *link;
 190         int reason_code = 0;
 191         struct msghdr msg;
 192         struct kvec vec;
 193         int len;
 194
 195         link = &conn->lgr->lnk[SMC_SINGLE_LINK];
 196         /* send SMC Confirm CLC msg */
 197         memset(&cclc, 0, sizeof(cclc));
 198         memcpy(cclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 199         cclc.hdr.type = SMC_CLC_CONFIRM;
 200         cclc.hdr.length = htons(sizeof(cclc));
 201         cclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 202         memcpy(cclc.lcl.id_for_peer, local_systemid, sizeof(local_systemid));
 203         memcpy(&cclc.lcl.gid, &link->smcibdev->gid[link->ibport - 1],
 204                SMC_GID_SIZE);
 205         memcpy(&cclc.lcl.mac, &link->smcibdev->mac[link->ibport - 1], ETH_ALEN);
 206         hton24(cclc.qpn, link->roce_qp->qp_num);
 207         cclc.rmb_rkey =
 208                 htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
 209         cclc.conn_idx = 1; /* for now: 1 RMB = 1 RMBE */
 210         cclc.rmbe_alert_token = htonl(conn->alert_token_local);
 211         cclc.qp_mtu = min(link->path_mtu, link->peer_mtu);
 212         cclc.rmbe_size = conn->rmbe_size_short;
 213         cclc.rmb_dma_addr = cpu_to_be64(
 214                 (u64)sg_dma_address(conn->rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
 215         hton24(cclc.psn, link->psn_initial);
 216
 217         memcpy(cclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 218
 219         memset(&msg, 0, sizeof(msg));
 220         vec.iov_base = &cclc;
 221         vec.iov_len = sizeof(cclc);
 222         len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1, sizeof(cclc));
 223         if (len < sizeof(cclc)) {
 224                 if (len >= 0) {
 225                         reason_code = -ENETUNREACH;
 226                         smc->sk.sk_err = -reason_code;
 227                 } else {
 228                         smc->sk.sk_err = smc->clcsock->sk->sk_err;
 229                         reason_code = -smc->sk.sk_err;
 230                 }
 231         }
 232         return reason_code;
 233 }
 234
 235 /* send CLC ACCEPT message across internal TCP socket */
 236 int smc_clc_send_accept(struct smc_sock *new_smc, int srv_first_contact)
 237 {
 238         struct smc_connection *conn = &new_smc->conn;
 239         struct smc_clc_msg_accept_confirm aclc;
 240         struct smc_link *link;
 241         struct msghdr msg;
 242         struct kvec vec;
 243         int rc = 0;
 244         int len;
 245
 246         link = &conn->lgr->lnk[SMC_SINGLE_LINK];
 247         memset(&aclc, 0, sizeof(aclc));
 248         memcpy(aclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 249         aclc.hdr.type = SMC_CLC_ACCEPT;
 250         aclc.hdr.length = htons(sizeof(aclc));
 251         aclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 252         if (srv_first_contact)
 253                 aclc.hdr.flag = 1;
 254         memcpy(aclc.lcl.id_for_peer, local_systemid, sizeof(local_systemid));
 255         memcpy(&aclc.lcl.gid, &link->smcibdev->gid[link->ibport - 1],
 256                SMC_GID_SIZE);
 257         memcpy(&aclc.lcl.mac, link->smcibdev->mac[link->ibport - 1], ETH_ALEN);
 258         hton24(aclc.qpn, link->roce_qp->qp_num);
 259         aclc.rmb_rkey =
 260                 htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
 261         aclc.conn_idx = 1;                      /* as long as 1 RMB = 1 RMBE */
 262         aclc.rmbe_alert_token = htonl(conn->alert_token_local);
 263         aclc.qp_mtu = link->path_mtu;
 264         aclc.rmbe_size = conn->rmbe_size_short,
 265         aclc.rmb_dma_addr = cpu_to_be64(
 266                 (u64)sg_dma_address(conn->rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
 267         hton24(aclc.psn, link->psn_initial);
 268         memcpy(aclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 269
 270         memset(&msg, 0, sizeof(msg));
 271         vec.iov_base = &aclc;
 272         vec.iov_len = sizeof(aclc);
 273         len = kernel_sendmsg(new_smc->clcsock, &msg, &vec, 1, sizeof(aclc));
 274         if (len < sizeof(aclc)) {
 275                 if (len >= 0)
 276                         new_smc->sk.sk_err = EPROTO;
 277                 else
 278                         new_smc->sk.sk_err = new_smc->clcsock->sk->sk_err;
 279                 rc = sock_error(&new_smc->sk);
 280         }
 281
 282         return rc;
 283 }