net/smc/smc_clc.c

   1 /*
   2  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
   3  *
   4  *  CLC (connection layer control) handshake over initial TCP socket to
   5  *  prepare for RDMA traffic
   6  *
   7  *  Copyright IBM Corp. 2016
   8  *
   9  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
  10  */
  11
  12 #include <linux/in.h>
  13 #include <linux/if_ether.h>
  14 #include <linux/sched/signal.h>
  15
  16 #include <net/sock.h>
  17 #include <net/tcp.h>
  18
  19 #include "smc.h"
  20 #include "smc_core.h"
  21 #include "smc_clc.h"
  22 #include "smc_ib.h"
  23
  24 /* Wait for data on the tcp-socket, analyze received data
  25  * Returns:
  26  * 0 if success and it was not a decline that we received.
  27  * SMC_CLC_DECL_REPLY if decline received for fallback w/o another decl send.
  28  * clcsock error, -EINTR, -ECONNRESET, -EPROTO otherwise.
  29  */
  30 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
  31                      u8 expected_type)
  32 {
  33         struct sock *clc_sk = smc->clcsock->sk;
  34         struct smc_clc_msg_hdr *clcm = buf;
  35         struct msghdr msg = {NULL, 0};
  36         int reason_code = 0;
  37         struct kvec vec;
  38         int len, datlen;
  39         int krflags;
  40
  41         /* peek the first few bytes to determine length of data to receive
  42          * so we don't consume any subsequent CLC message or payload data
  43          * in the TCP byte stream
  44          */
  45         vec.iov_base = buf;
  46         vec.iov_len = buflen;
  47         krflags = MSG_PEEK | MSG_WAITALL;
  48         smc->clcsock->sk->sk_rcvtimeo = CLC_WAIT_TIME;
  49         len = kernel_recvmsg(smc->clcsock, &msg, &vec, 1,
  50                              sizeof(struct smc_clc_msg_hdr), krflags);
  51         if (signal_pending(current)) {
  52                 reason_code = -EINTR;
  53                 clc_sk->sk_err = EINTR;
  54                 smc->sk.sk_err = EINTR;
  55                 goto out;
  56         }
  57         if (clc_sk->sk_err) {
  58                 reason_code = -clc_sk->sk_err;
  59                 smc->sk.sk_err = clc_sk->sk_err;
  60                 goto out;
  61         }
  62         if (!len) { /* peer has performed orderly shutdown */
  63                 smc->sk.sk_err = ECONNRESET;
  64                 reason_code = -ECONNRESET;
  65                 goto out;
  66         }
  67         if (len < 0) {
  68                 smc->sk.sk_err = -len;
  69                 reason_code = len;
  70                 goto out;
  71         }
  72         datlen = ntohs(clcm->length);
  73         if ((len < sizeof(struct smc_clc_msg_hdr)) ||
  74             (datlen < sizeof(struct smc_clc_msg_decline)) ||
  75             (datlen > sizeof(struct smc_clc_msg_accept_confirm)) ||
  76             memcmp(clcm->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) ||
  77             ((clcm->type != SMC_CLC_DECLINE) &&
  78              (clcm->type != expected_type))) {
  79                 smc->sk.sk_err = EPROTO;
  80                 reason_code = -EPROTO;
  81                 goto out;
  82         }
  83
  84         /* receive the complete CLC message */
  85         vec.iov_base = buf;
  86         vec.iov_len = buflen;
  87         memset(&msg, 0, sizeof(struct msghdr));
  88         krflags = MSG_WAITALL;
  89         smc->clcsock->sk->sk_rcvtimeo = CLC_WAIT_TIME;
  90         len = kernel_recvmsg(smc->clcsock, &msg, &vec, 1, datlen, krflags);
  91         if (len < datlen) {
  92                 smc->sk.sk_err = EPROTO;
  93                 reason_code = -EPROTO;
  94                 goto out;
  95         }
  96         if (clcm->type == SMC_CLC_DECLINE) {
  97                 reason_code = SMC_CLC_DECL_REPLY;
  98                 if (ntohl(((struct smc_clc_msg_decline *)buf)->peer_diagnosis)
  99                         == SMC_CLC_DECL_SYNCERR)
 100                         smc->conn.lgr->sync_err = true;
 101         }
 102
 103 out:
 104         return reason_code;
 105 }
 106
 107 /* send CLC DECLINE message across internal TCP socket */
 108 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info,
 109                          u8 out_of_sync)
 110 {
 111         struct smc_clc_msg_decline dclc;
 112         struct msghdr msg;
 113         struct kvec vec;
 114         int len;
 115
 116         memset(&dclc, 0, sizeof(dclc));
 117         memcpy(dclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 118         dclc.hdr.type = SMC_CLC_DECLINE;
 119         dclc.hdr.length = htons(sizeof(struct smc_clc_msg_decline));
 120         dclc.hdr.version = SMC_CLC_V1;
 121         dclc.hdr.flag = out_of_sync ? 1 : 0;
 122         memcpy(dclc.id_for_peer, local_systemid, sizeof(local_systemid));
 123         dclc.peer_diagnosis = htonl(peer_diag_info);
 124         memcpy(dclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 125
 126         memset(&msg, 0, sizeof(msg));
 127         vec.iov_base = &dclc;
 128         vec.iov_len = sizeof(struct smc_clc_msg_decline);
 129         len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
 130                              sizeof(struct smc_clc_msg_decline));
 131         if (len < sizeof(struct smc_clc_msg_decline))
 132                 smc->sk.sk_err = EPROTO;
 133         if (len < 0)
 134                 smc->sk.sk_err = -len;
 135         return len;
 136 }
 137
 138 /* send CLC PROPOSAL message across internal TCP socket */
 139 int smc_clc_send_proposal(struct smc_sock *smc,
 140                           struct smc_ib_device *smcibdev,
 141                           u8 ibport)
 142 {
 143         struct smc_clc_msg_proposal pclc;
 144         int reason_code = 0;
 145         struct msghdr msg;
 146         struct kvec vec;
 147         int len, rc;
 148
 149         /* send SMC Proposal CLC message */
 150         memset(&pclc, 0, sizeof(pclc));
 151         memcpy(pclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 152         pclc.hdr.type = SMC_CLC_PROPOSAL;
 153         pclc.hdr.length = htons(sizeof(pclc));
 154         pclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 155         memcpy(pclc.lcl.id_for_peer, local_systemid, sizeof(local_systemid));
 156         memcpy(&pclc.lcl.gid, &smcibdev->gid[ibport - 1], SMC_GID_SIZE);
 157         memcpy(&pclc.lcl.mac, &smcibdev->mac[ibport - 1], ETH_ALEN);
 158
 159         /* determine subnet and mask from internal TCP socket */
 160         rc = smc_netinfo_by_tcpsk(smc->clcsock, &pclc.outgoing_subnet,
 161                                   &pclc.prefix_len);
 162         if (rc)
 163                 return SMC_CLC_DECL_CNFERR; /* configuration error */
 164         memcpy(pclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 165         memset(&msg, 0, sizeof(msg));
 166         vec.iov_base = &pclc;
 167         vec.iov_len = sizeof(pclc);
 168         /* due to the few bytes needed for clc-handshake this cannot block */
 169         len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1, sizeof(pclc));
 170         if (len < sizeof(pclc)) {
 171                 if (len >= 0) {
 172                         reason_code = -ENETUNREACH;
 173                         smc->sk.sk_err = -reason_code;
 174                 } else {
 175                         smc->sk.sk_err = smc->clcsock->sk->sk_err;
 176                         reason_code = -smc->sk.sk_err;
 177                 }
 178         }
 179
 180         return reason_code;
 181 }
 182
 183 /* send CLC CONFIRM message across internal TCP socket */
 184 int smc_clc_send_confirm(struct smc_sock *smc)
 185 {
 186         struct smc_connection *conn = &smc->conn;
 187         struct smc_clc_msg_accept_confirm cclc;
 188         struct smc_link *link;
 189         int reason_code = 0;
 190         struct msghdr msg;
 191         struct kvec vec;
 192         int len;
 193
 194         link = &conn->lgr->lnk[SMC_SINGLE_LINK];
 195         /* send SMC Confirm CLC msg */
 196         memset(&cclc, 0, sizeof(cclc));
 197         memcpy(cclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 198         cclc.hdr.type = SMC_CLC_CONFIRM;
 199         cclc.hdr.length = htons(sizeof(cclc));
 200         cclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 201         memcpy(cclc.lcl.id_for_peer, local_systemid, sizeof(local_systemid));
 202         memcpy(&cclc.lcl.gid, &link->smcibdev->gid[link->ibport - 1],
 203                SMC_GID_SIZE);
 204         memcpy(&cclc.lcl.mac, &link->smcibdev->mac[link->ibport - 1], ETH_ALEN);
 205         hton24(cclc.qpn, link->roce_qp->qp_num);
 206         cclc.rmb_rkey =
 207                 htonl(conn->rmb_desc->rkey[SMC_SINGLE_LINK]);
 208         cclc.conn_idx = 1; /* for now: 1 RMB = 1 RMBE */
 209         cclc.rmbe_alert_token = htonl(conn->alert_token_local);
 210         cclc.qp_mtu = min(link->path_mtu, link->peer_mtu);
 211         cclc.rmbe_size = conn->rmbe_size_short;
 212         cclc.rmb_dma_addr =
 213                 cpu_to_be64((u64)conn->rmb_desc->dma_addr[SMC_SINGLE_LINK]);
 214         hton24(cclc.psn, link->psn_initial);
 215
 216         memcpy(cclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 217
 218         memset(&msg, 0, sizeof(msg));
 219         vec.iov_base = &cclc;
 220         vec.iov_len = sizeof(cclc);
 221         len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1, sizeof(cclc));
 222         if (len < sizeof(cclc)) {
 223                 if (len >= 0) {
 224                         reason_code = -ENETUNREACH;
 225                         smc->sk.sk_err = -reason_code;
 226                 } else {
 227                         smc->sk.sk_err = smc->clcsock->sk->sk_err;
 228                         reason_code = -smc->sk.sk_err;
 229                 }
 230         }
 231         return reason_code;
 232 }
 233
 234 /* send CLC ACCEPT message across internal TCP socket */
 235 int smc_clc_send_accept(struct smc_sock *new_smc, int srv_first_contact)
 236 {
 237         struct smc_connection *conn = &new_smc->conn;
 238         struct smc_clc_msg_accept_confirm aclc;
 239         struct smc_link *link;
 240         struct msghdr msg;
 241         struct kvec vec;
 242         int rc = 0;
 243         int len;
 244
 245         link = &conn->lgr->lnk[SMC_SINGLE_LINK];
 246         memset(&aclc, 0, sizeof(aclc));
 247         memcpy(aclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 248         aclc.hdr.type = SMC_CLC_ACCEPT;
 249         aclc.hdr.length = htons(sizeof(aclc));
 250         aclc.hdr.version = SMC_CLC_V1;          /* SMC version */
 251         if (srv_first_contact)
 252                 aclc.hdr.flag = 1;
 253         memcpy(aclc.lcl.id_for_peer, local_systemid, sizeof(local_systemid));
 254         memcpy(&aclc.lcl.gid, &link->smcibdev->gid[link->ibport - 1],
 255                SMC_GID_SIZE);
 256         memcpy(&aclc.lcl.mac, link->smcibdev->mac[link->ibport - 1], ETH_ALEN);
 257         hton24(aclc.qpn, link->roce_qp->qp_num);
 258         aclc.rmb_rkey =
 259                 htonl(conn->rmb_desc->rkey[SMC_SINGLE_LINK]);
 260         aclc.conn_idx = 1;                      /* as long as 1 RMB = 1 RMBE */
 261         aclc.rmbe_alert_token = htonl(conn->alert_token_local);
 262         aclc.qp_mtu = link->path_mtu;
 263         aclc.rmbe_size = conn->rmbe_size_short,
 264         aclc.rmb_dma_addr =
 265                 cpu_to_be64((u64)conn->rmb_desc->dma_addr[SMC_SINGLE_LINK]);
 266         hton24(aclc.psn, link->psn_initial);
 267         memcpy(aclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 268
 269         memset(&msg, 0, sizeof(msg));
 270         vec.iov_base = &aclc;
 271         vec.iov_len = sizeof(aclc);
 272         len = kernel_sendmsg(new_smc->clcsock, &msg, &vec, 1, sizeof(aclc));
 273         if (len < sizeof(aclc)) {
 274                 if (len >= 0)
 275                         new_smc->sk.sk_err = EPROTO;
 276                 else
 277                         new_smc->sk.sk_err = new_smc->clcsock->sk->sk_err;
 278                 rc = sock_error(&new_smc->sk);
 279         }
 280
 281         return rc;
 282 }