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