1 // SPDX-License-Identifier: GPL-2.0
3 * Shared Memory Communications over RDMA (SMC-R) and RoCE
5 * CLC (connection layer control) handshake over initial TCP socket to
6 * prepare for RDMA traffic
8 * Copyright IBM Corp. 2016, 2018
10 * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
14 #include <linux/inetdevice.h>
15 #include <linux/if_ether.h>
16 #include <linux/sched/signal.h>
18 #include <net/addrconf.h>
28 #define SMCR_CLC_ACCEPT_CONFIRM_LEN 68
29 #define SMCD_CLC_ACCEPT_CONFIRM_LEN 48
31 /* eye catcher "SMCR" EBCDIC for CLC messages */
32 static const char SMC_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xd9'};
33 /* eye catcher "SMCD" EBCDIC for CLC messages */
34 static const char SMCD_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xc4'};
36 /* check if received message has a correct header length and contains valid
37 * heading and trailing eyecatchers
39 static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm)
41 struct smc_clc_msg_proposal_prefix *pclc_prfx;
42 struct smc_clc_msg_accept_confirm *clc;
43 struct smc_clc_msg_proposal *pclc;
44 struct smc_clc_msg_decline *dclc;
45 struct smc_clc_msg_trail *trl;
47 if (memcmp(clcm->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
48 memcmp(clcm->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
51 case SMC_CLC_PROPOSAL:
52 if (clcm->path != SMC_TYPE_R && clcm->path != SMC_TYPE_D &&
53 clcm->path != SMC_TYPE_B)
55 pclc = (struct smc_clc_msg_proposal *)clcm;
56 pclc_prfx = smc_clc_proposal_get_prefix(pclc);
57 if (ntohs(pclc->hdr.length) !=
58 sizeof(*pclc) + ntohs(pclc->iparea_offset) +
60 pclc_prfx->ipv6_prefixes_cnt *
61 sizeof(struct smc_clc_ipv6_prefix) +
64 trl = (struct smc_clc_msg_trail *)
65 ((u8 *)pclc + ntohs(pclc->hdr.length) - sizeof(*trl));
69 if (clcm->path != SMC_TYPE_R && clcm->path != SMC_TYPE_D)
71 clc = (struct smc_clc_msg_accept_confirm *)clcm;
72 if ((clcm->path == SMC_TYPE_R &&
73 ntohs(clc->hdr.length) != SMCR_CLC_ACCEPT_CONFIRM_LEN) ||
74 (clcm->path == SMC_TYPE_D &&
75 ntohs(clc->hdr.length) != SMCD_CLC_ACCEPT_CONFIRM_LEN))
77 trl = (struct smc_clc_msg_trail *)
78 ((u8 *)clc + ntohs(clc->hdr.length) - sizeof(*trl));
81 dclc = (struct smc_clc_msg_decline *)clcm;
82 if (ntohs(dclc->hdr.length) != sizeof(*dclc))
89 if (memcmp(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
90 memcmp(trl->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
95 /* find ipv4 addr on device and get the prefix len, fill CLC proposal msg */
96 static int smc_clc_prfx_set4_rcu(struct dst_entry *dst, __be32 ipv4,
97 struct smc_clc_msg_proposal_prefix *prop)
99 struct in_device *in_dev = __in_dev_get_rcu(dst->dev);
100 const struct in_ifaddr *ifa;
105 in_dev_for_each_ifa_rcu(ifa, in_dev) {
106 if (!inet_ifa_match(ipv4, ifa))
108 prop->prefix_len = inet_mask_len(ifa->ifa_mask);
109 prop->outgoing_subnet = ifa->ifa_address & ifa->ifa_mask;
110 /* prop->ipv6_prefixes_cnt = 0; already done by memset before */
116 /* fill CLC proposal msg with ipv6 prefixes from device */
117 static int smc_clc_prfx_set6_rcu(struct dst_entry *dst,
118 struct smc_clc_msg_proposal_prefix *prop,
119 struct smc_clc_ipv6_prefix *ipv6_prfx)
121 #if IS_ENABLED(CONFIG_IPV6)
122 struct inet6_dev *in6_dev = __in6_dev_get(dst->dev);
123 struct inet6_ifaddr *ifa;
128 /* use a maximum of 8 IPv6 prefixes from device */
129 list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
130 if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
132 ipv6_addr_prefix(&ipv6_prfx[cnt].prefix,
133 &ifa->addr, ifa->prefix_len);
134 ipv6_prfx[cnt].prefix_len = ifa->prefix_len;
136 if (cnt == SMC_CLC_MAX_V6_PREFIX)
139 prop->ipv6_prefixes_cnt = cnt;
146 /* retrieve and set prefixes in CLC proposal msg */
147 static int smc_clc_prfx_set(struct socket *clcsock,
148 struct smc_clc_msg_proposal_prefix *prop,
149 struct smc_clc_ipv6_prefix *ipv6_prfx)
151 struct dst_entry *dst = sk_dst_get(clcsock->sk);
152 struct sockaddr_storage addrs;
153 struct sockaddr_in6 *addr6;
154 struct sockaddr_in *addr;
157 memset(prop, 0, sizeof(*prop));
166 /* get address to which the internal TCP socket is bound */
167 if (kernel_getsockname(clcsock, (struct sockaddr *)&addrs) < 0)
169 /* analyze IP specific data of net_device belonging to TCP socket */
170 addr6 = (struct sockaddr_in6 *)&addrs;
172 if (addrs.ss_family == PF_INET) {
174 addr = (struct sockaddr_in *)&addrs;
175 rc = smc_clc_prfx_set4_rcu(dst, addr->sin_addr.s_addr, prop);
176 } else if (ipv6_addr_v4mapped(&addr6->sin6_addr)) {
177 /* mapped IPv4 address - peer is IPv4 only */
178 rc = smc_clc_prfx_set4_rcu(dst, addr6->sin6_addr.s6_addr32[3],
182 rc = smc_clc_prfx_set6_rcu(dst, prop, ipv6_prfx);
191 /* match ipv4 addrs of dev against addr in CLC proposal */
192 static int smc_clc_prfx_match4_rcu(struct net_device *dev,
193 struct smc_clc_msg_proposal_prefix *prop)
195 struct in_device *in_dev = __in_dev_get_rcu(dev);
196 const struct in_ifaddr *ifa;
200 in_dev_for_each_ifa_rcu(ifa, in_dev) {
201 if (prop->prefix_len == inet_mask_len(ifa->ifa_mask) &&
202 inet_ifa_match(prop->outgoing_subnet, ifa))
209 /* match ipv6 addrs of dev against addrs in CLC proposal */
210 static int smc_clc_prfx_match6_rcu(struct net_device *dev,
211 struct smc_clc_msg_proposal_prefix *prop)
213 #if IS_ENABLED(CONFIG_IPV6)
214 struct inet6_dev *in6_dev = __in6_dev_get(dev);
215 struct smc_clc_ipv6_prefix *ipv6_prfx;
216 struct inet6_ifaddr *ifa;
221 /* ipv6 prefix list starts behind smc_clc_msg_proposal_prefix */
222 ipv6_prfx = (struct smc_clc_ipv6_prefix *)((u8 *)prop + sizeof(*prop));
223 max = min_t(u8, prop->ipv6_prefixes_cnt, SMC_CLC_MAX_V6_PREFIX);
224 list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
225 if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
227 for (i = 0; i < max; i++) {
228 if (ifa->prefix_len == ipv6_prfx[i].prefix_len &&
229 ipv6_prefix_equal(&ifa->addr, &ipv6_prfx[i].prefix,
238 /* check if proposed prefixes match one of our device prefixes */
239 int smc_clc_prfx_match(struct socket *clcsock,
240 struct smc_clc_msg_proposal_prefix *prop)
242 struct dst_entry *dst = sk_dst_get(clcsock->sk);
254 if (!prop->ipv6_prefixes_cnt)
255 rc = smc_clc_prfx_match4_rcu(dst->dev, prop);
257 rc = smc_clc_prfx_match6_rcu(dst->dev, prop);
265 /* Wait for data on the tcp-socket, analyze received data
267 * 0 if success and it was not a decline that we received.
268 * SMC_CLC_DECL_REPLY if decline received for fallback w/o another decl send.
269 * clcsock error, -EINTR, -ECONNRESET, -EPROTO otherwise.
271 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
272 u8 expected_type, unsigned long timeout)
274 long rcvtimeo = smc->clcsock->sk->sk_rcvtimeo;
275 struct sock *clc_sk = smc->clcsock->sk;
276 struct smc_clc_msg_hdr *clcm = buf;
277 struct msghdr msg = {NULL, 0};
279 struct kvec vec = {buf, buflen};
283 /* peek the first few bytes to determine length of data to receive
284 * so we don't consume any subsequent CLC message or payload data
285 * in the TCP byte stream
288 * Caller must make sure that buflen is no less than
289 * sizeof(struct smc_clc_msg_hdr)
291 krflags = MSG_PEEK | MSG_WAITALL;
292 clc_sk->sk_rcvtimeo = timeout;
293 iov_iter_kvec(&msg.msg_iter, READ, &vec, 1,
294 sizeof(struct smc_clc_msg_hdr));
295 len = sock_recvmsg(smc->clcsock, &msg, krflags);
296 if (signal_pending(current)) {
297 reason_code = -EINTR;
298 clc_sk->sk_err = EINTR;
299 smc->sk.sk_err = EINTR;
302 if (clc_sk->sk_err) {
303 reason_code = -clc_sk->sk_err;
304 if (clc_sk->sk_err == EAGAIN &&
305 expected_type == SMC_CLC_DECLINE)
306 clc_sk->sk_err = 0; /* reset for fallback usage */
308 smc->sk.sk_err = clc_sk->sk_err;
311 if (!len) { /* peer has performed orderly shutdown */
312 smc->sk.sk_err = ECONNRESET;
313 reason_code = -ECONNRESET;
317 if (len != -EAGAIN || expected_type != SMC_CLC_DECLINE)
318 smc->sk.sk_err = -len;
322 datlen = ntohs(clcm->length);
323 if ((len < sizeof(struct smc_clc_msg_hdr)) ||
325 (clcm->version != SMC_CLC_V1) ||
326 (clcm->path != SMC_TYPE_R && clcm->path != SMC_TYPE_D &&
327 clcm->path != SMC_TYPE_B) ||
328 ((clcm->type != SMC_CLC_DECLINE) &&
329 (clcm->type != expected_type))) {
330 smc->sk.sk_err = EPROTO;
331 reason_code = -EPROTO;
335 /* receive the complete CLC message */
336 memset(&msg, 0, sizeof(struct msghdr));
337 iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, datlen);
338 krflags = MSG_WAITALL;
339 len = sock_recvmsg(smc->clcsock, &msg, krflags);
340 if (len < datlen || !smc_clc_msg_hdr_valid(clcm)) {
341 smc->sk.sk_err = EPROTO;
342 reason_code = -EPROTO;
345 if (clcm->type == SMC_CLC_DECLINE) {
346 struct smc_clc_msg_decline *dclc;
348 dclc = (struct smc_clc_msg_decline *)clcm;
349 reason_code = SMC_CLC_DECL_PEERDECL;
350 smc->peer_diagnosis = ntohl(dclc->peer_diagnosis);
351 if (((struct smc_clc_msg_decline *)buf)->hdr.flag) {
352 smc->conn.lgr->sync_err = 1;
353 smc_lgr_terminate(smc->conn.lgr);
358 clc_sk->sk_rcvtimeo = rcvtimeo;
362 /* send CLC DECLINE message across internal TCP socket */
363 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info)
365 struct smc_clc_msg_decline dclc;
370 memset(&dclc, 0, sizeof(dclc));
371 memcpy(dclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
372 dclc.hdr.type = SMC_CLC_DECLINE;
373 dclc.hdr.length = htons(sizeof(struct smc_clc_msg_decline));
374 dclc.hdr.version = SMC_CLC_V1;
375 dclc.hdr.flag = (peer_diag_info == SMC_CLC_DECL_SYNCERR) ? 1 : 0;
376 if (smc->conn.lgr && !smc->conn.lgr->is_smcd)
377 memcpy(dclc.id_for_peer, local_systemid,
378 sizeof(local_systemid));
379 dclc.peer_diagnosis = htonl(peer_diag_info);
380 memcpy(dclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
382 memset(&msg, 0, sizeof(msg));
383 vec.iov_base = &dclc;
384 vec.iov_len = sizeof(struct smc_clc_msg_decline);
385 len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
386 sizeof(struct smc_clc_msg_decline));
387 if (len < 0 || len < sizeof(struct smc_clc_msg_decline))
389 return len > 0 ? 0 : len;
392 /* send CLC PROPOSAL message across internal TCP socket */
393 int smc_clc_send_proposal(struct smc_sock *smc, int smc_type,
394 struct smc_init_info *ini)
396 struct smc_clc_ipv6_prefix ipv6_prfx[SMC_CLC_MAX_V6_PREFIX];
397 struct smc_clc_msg_proposal_prefix pclc_prfx;
398 struct smc_clc_msg_smcd pclc_smcd;
399 struct smc_clc_msg_proposal pclc;
400 struct smc_clc_msg_trail trl;
401 int len, i, plen, rc;
406 /* retrieve ip prefixes for CLC proposal msg */
407 rc = smc_clc_prfx_set(smc->clcsock, &pclc_prfx, ipv6_prfx);
409 return SMC_CLC_DECL_CNFERR; /* configuration error */
411 /* send SMC Proposal CLC message */
412 plen = sizeof(pclc) + sizeof(pclc_prfx) +
413 (pclc_prfx.ipv6_prefixes_cnt * sizeof(ipv6_prfx[0])) +
415 memset(&pclc, 0, sizeof(pclc));
416 memcpy(pclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
417 pclc.hdr.type = SMC_CLC_PROPOSAL;
418 pclc.hdr.version = SMC_CLC_V1; /* SMC version */
419 pclc.hdr.path = smc_type;
420 if (smc_type == SMC_TYPE_R || smc_type == SMC_TYPE_B) {
421 /* add SMC-R specifics */
422 memcpy(pclc.lcl.id_for_peer, local_systemid,
423 sizeof(local_systemid));
424 memcpy(&pclc.lcl.gid, ini->ib_gid, SMC_GID_SIZE);
425 memcpy(&pclc.lcl.mac, &ini->ib_dev->mac[ini->ib_port - 1],
427 pclc.iparea_offset = htons(0);
429 if (smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B) {
430 /* add SMC-D specifics */
431 memset(&pclc_smcd, 0, sizeof(pclc_smcd));
432 plen += sizeof(pclc_smcd);
433 pclc.iparea_offset = htons(SMC_CLC_PROPOSAL_MAX_OFFSET);
434 pclc_smcd.gid = ini->ism_dev->local_gid;
436 pclc.hdr.length = htons(plen);
438 memcpy(trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
439 memset(&msg, 0, sizeof(msg));
441 vec[i].iov_base = &pclc;
442 vec[i++].iov_len = sizeof(pclc);
443 if (smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B) {
444 vec[i].iov_base = &pclc_smcd;
445 vec[i++].iov_len = sizeof(pclc_smcd);
447 vec[i].iov_base = &pclc_prfx;
448 vec[i++].iov_len = sizeof(pclc_prfx);
449 if (pclc_prfx.ipv6_prefixes_cnt > 0) {
450 vec[i].iov_base = &ipv6_prfx[0];
451 vec[i++].iov_len = pclc_prfx.ipv6_prefixes_cnt *
452 sizeof(ipv6_prfx[0]);
454 vec[i].iov_base = &trl;
455 vec[i++].iov_len = sizeof(trl);
456 /* due to the few bytes needed for clc-handshake this cannot block */
457 len = kernel_sendmsg(smc->clcsock, &msg, vec, i, plen);
459 smc->sk.sk_err = smc->clcsock->sk->sk_err;
460 reason_code = -smc->sk.sk_err;
461 } else if (len < (int)sizeof(pclc)) {
462 reason_code = -ENETUNREACH;
463 smc->sk.sk_err = -reason_code;
469 /* send CLC CONFIRM message across internal TCP socket */
470 int smc_clc_send_confirm(struct smc_sock *smc)
472 struct smc_connection *conn = &smc->conn;
473 struct smc_clc_msg_accept_confirm cclc;
474 struct smc_link *link;
480 /* send SMC Confirm CLC msg */
481 memset(&cclc, 0, sizeof(cclc));
482 cclc.hdr.type = SMC_CLC_CONFIRM;
483 cclc.hdr.version = SMC_CLC_V1; /* SMC version */
484 if (smc->conn.lgr->is_smcd) {
485 /* SMC-D specific settings */
486 memcpy(cclc.hdr.eyecatcher, SMCD_EYECATCHER,
487 sizeof(SMCD_EYECATCHER));
488 cclc.hdr.path = SMC_TYPE_D;
489 cclc.hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
490 cclc.gid = conn->lgr->smcd->local_gid;
491 cclc.token = conn->rmb_desc->token;
492 cclc.dmbe_size = conn->rmbe_size_short;
494 memcpy(&cclc.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
495 memcpy(cclc.smcd_trl.eyecatcher, SMCD_EYECATCHER,
496 sizeof(SMCD_EYECATCHER));
498 /* SMC-R specific settings */
499 link = &conn->lgr->lnk[SMC_SINGLE_LINK];
500 memcpy(cclc.hdr.eyecatcher, SMC_EYECATCHER,
501 sizeof(SMC_EYECATCHER));
502 cclc.hdr.path = SMC_TYPE_R;
503 cclc.hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
504 memcpy(cclc.lcl.id_for_peer, local_systemid,
505 sizeof(local_systemid));
506 memcpy(&cclc.lcl.gid, link->gid, SMC_GID_SIZE);
507 memcpy(&cclc.lcl.mac, &link->smcibdev->mac[link->ibport - 1],
509 hton24(cclc.qpn, link->roce_qp->qp_num);
511 htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
512 cclc.rmbe_idx = 1; /* for now: 1 RMB = 1 RMBE */
513 cclc.rmbe_alert_token = htonl(conn->alert_token_local);
514 cclc.qp_mtu = min(link->path_mtu, link->peer_mtu);
515 cclc.rmbe_size = conn->rmbe_size_short;
516 cclc.rmb_dma_addr = cpu_to_be64((u64)sg_dma_address
517 (conn->rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
518 hton24(cclc.psn, link->psn_initial);
519 memcpy(cclc.smcr_trl.eyecatcher, SMC_EYECATCHER,
520 sizeof(SMC_EYECATCHER));
523 memset(&msg, 0, sizeof(msg));
524 vec.iov_base = &cclc;
525 vec.iov_len = ntohs(cclc.hdr.length);
526 len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
527 ntohs(cclc.hdr.length));
528 if (len < ntohs(cclc.hdr.length)) {
530 reason_code = -ENETUNREACH;
531 smc->sk.sk_err = -reason_code;
533 smc->sk.sk_err = smc->clcsock->sk->sk_err;
534 reason_code = -smc->sk.sk_err;
540 /* send CLC ACCEPT message across internal TCP socket */
541 int smc_clc_send_accept(struct smc_sock *new_smc, int srv_first_contact)
543 struct smc_connection *conn = &new_smc->conn;
544 struct smc_clc_msg_accept_confirm aclc;
545 struct smc_link *link;
550 memset(&aclc, 0, sizeof(aclc));
551 aclc.hdr.type = SMC_CLC_ACCEPT;
552 aclc.hdr.version = SMC_CLC_V1; /* SMC version */
553 if (srv_first_contact)
556 if (new_smc->conn.lgr->is_smcd) {
557 /* SMC-D specific settings */
558 aclc.hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
559 memcpy(aclc.hdr.eyecatcher, SMCD_EYECATCHER,
560 sizeof(SMCD_EYECATCHER));
561 aclc.hdr.path = SMC_TYPE_D;
562 aclc.gid = conn->lgr->smcd->local_gid;
563 aclc.token = conn->rmb_desc->token;
564 aclc.dmbe_size = conn->rmbe_size_short;
566 memcpy(&aclc.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
567 memcpy(aclc.smcd_trl.eyecatcher, SMCD_EYECATCHER,
568 sizeof(SMCD_EYECATCHER));
570 /* SMC-R specific settings */
571 aclc.hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
572 memcpy(aclc.hdr.eyecatcher, SMC_EYECATCHER,
573 sizeof(SMC_EYECATCHER));
574 aclc.hdr.path = SMC_TYPE_R;
575 link = &conn->lgr->lnk[SMC_SINGLE_LINK];
576 memcpy(aclc.lcl.id_for_peer, local_systemid,
577 sizeof(local_systemid));
578 memcpy(&aclc.lcl.gid, link->gid, SMC_GID_SIZE);
579 memcpy(&aclc.lcl.mac, link->smcibdev->mac[link->ibport - 1],
581 hton24(aclc.qpn, link->roce_qp->qp_num);
583 htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
584 aclc.rmbe_idx = 1; /* as long as 1 RMB = 1 RMBE */
585 aclc.rmbe_alert_token = htonl(conn->alert_token_local);
586 aclc.qp_mtu = link->path_mtu;
587 aclc.rmbe_size = conn->rmbe_size_short,
588 aclc.rmb_dma_addr = cpu_to_be64((u64)sg_dma_address
589 (conn->rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
590 hton24(aclc.psn, link->psn_initial);
591 memcpy(aclc.smcr_trl.eyecatcher, SMC_EYECATCHER,
592 sizeof(SMC_EYECATCHER));
595 memset(&msg, 0, sizeof(msg));
596 vec.iov_base = &aclc;
597 vec.iov_len = ntohs(aclc.hdr.length);
598 len = kernel_sendmsg(new_smc->clcsock, &msg, &vec, 1,
599 ntohs(aclc.hdr.length));
600 if (len < ntohs(aclc.hdr.length))
601 len = len >= 0 ? -EPROTO : -new_smc->clcsock->sk->sk_err;
603 return len > 0 ? 0 : len;