xref: /linux/net/smc/smc_clc.c (revision 9052e9c95d908d6c3d7570aadc8898e1d871c8bb)
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, 2018
9  *
10  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
11  */
12 
13 #include <linux/in.h>
14 #include <linux/inetdevice.h>
15 #include <linux/if_ether.h>
16 #include <linux/sched/signal.h>
17 #include <linux/utsname.h>
18 #include <linux/ctype.h>
19 
20 #include <net/addrconf.h>
21 #include <net/sock.h>
22 #include <net/tcp.h>
23 
24 #include "smc.h"
25 #include "smc_core.h"
26 #include "smc_clc.h"
27 #include "smc_ib.h"
28 #include "smc_ism.h"
29 
30 #define SMCR_CLC_ACCEPT_CONFIRM_LEN 68
31 #define SMCD_CLC_ACCEPT_CONFIRM_LEN 48
32 #define SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 78
33 #define SMC_CLC_RECV_BUF_LEN	100
34 
35 /* eye catcher "SMCR" EBCDIC for CLC messages */
36 static const char SMC_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xd9'};
37 /* eye catcher "SMCD" EBCDIC for CLC messages */
38 static const char SMCD_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xc4'};
39 
40 static u8 smc_hostname[SMC_MAX_HOSTNAME_LEN];
41 
42 /* check arriving CLC proposal */
43 static bool smc_clc_msg_prop_valid(struct smc_clc_msg_proposal *pclc)
44 {
45 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
46 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
47 	struct smc_clc_msg_hdr *hdr = &pclc->hdr;
48 	struct smc_clc_v2_extension *v2_ext;
49 
50 	v2_ext = smc_get_clc_v2_ext(pclc);
51 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
52 	if (hdr->version == SMC_V1) {
53 		if (hdr->typev1 == SMC_TYPE_N)
54 			return false;
55 		if (ntohs(hdr->length) !=
56 			sizeof(*pclc) + ntohs(pclc->iparea_offset) +
57 			sizeof(*pclc_prfx) +
58 			pclc_prfx->ipv6_prefixes_cnt *
59 				sizeof(struct smc_clc_ipv6_prefix) +
60 			sizeof(struct smc_clc_msg_trail))
61 			return false;
62 	} else {
63 		if (ntohs(hdr->length) !=
64 			sizeof(*pclc) +
65 			sizeof(struct smc_clc_msg_smcd) +
66 			(hdr->typev1 != SMC_TYPE_N ?
67 				sizeof(*pclc_prfx) +
68 				pclc_prfx->ipv6_prefixes_cnt *
69 				sizeof(struct smc_clc_ipv6_prefix) : 0) +
70 			(hdr->typev2 != SMC_TYPE_N ?
71 				sizeof(*v2_ext) +
72 				v2_ext->hdr.eid_cnt * SMC_MAX_EID_LEN : 0) +
73 			(smcd_indicated(hdr->typev2) ?
74 				sizeof(*smcd_v2_ext) + v2_ext->hdr.ism_gid_cnt *
75 					sizeof(struct smc_clc_smcd_gid_chid) :
76 				0) +
77 			sizeof(struct smc_clc_msg_trail))
78 			return false;
79 	}
80 	return true;
81 }
82 
83 /* check arriving CLC accept or confirm */
84 static bool
85 smc_clc_msg_acc_conf_valid(struct smc_clc_msg_accept_confirm_v2 *clc_v2)
86 {
87 	struct smc_clc_msg_hdr *hdr = &clc_v2->hdr;
88 
89 	if (hdr->typev1 != SMC_TYPE_R && hdr->typev1 != SMC_TYPE_D)
90 		return false;
91 	if (hdr->version == SMC_V1) {
92 		if ((hdr->typev1 == SMC_TYPE_R &&
93 		     ntohs(hdr->length) != SMCR_CLC_ACCEPT_CONFIRM_LEN) ||
94 		    (hdr->typev1 == SMC_TYPE_D &&
95 		     ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN))
96 			return false;
97 	} else {
98 		if (hdr->typev1 == SMC_TYPE_D &&
99 		    ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 &&
100 		    (ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 +
101 				sizeof(struct smc_clc_first_contact_ext)))
102 			return false;
103 	}
104 	return true;
105 }
106 
107 static void smc_clc_fill_fce(struct smc_clc_first_contact_ext *fce, int *len)
108 {
109 	memset(fce, 0, sizeof(*fce));
110 	fce->os_type = SMC_CLC_OS_LINUX;
111 	fce->release = SMC_RELEASE;
112 	memcpy(fce->hostname, smc_hostname, sizeof(smc_hostname));
113 	(*len) += sizeof(*fce);
114 }
115 
116 /* check if received message has a correct header length and contains valid
117  * heading and trailing eyecatchers
118  */
119 static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm, bool check_trl)
120 {
121 	struct smc_clc_msg_accept_confirm_v2 *clc_v2;
122 	struct smc_clc_msg_proposal *pclc;
123 	struct smc_clc_msg_decline *dclc;
124 	struct smc_clc_msg_trail *trl;
125 
126 	if (memcmp(clcm->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
127 	    memcmp(clcm->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
128 		return false;
129 	switch (clcm->type) {
130 	case SMC_CLC_PROPOSAL:
131 		pclc = (struct smc_clc_msg_proposal *)clcm;
132 		if (!smc_clc_msg_prop_valid(pclc))
133 			return false;
134 		trl = (struct smc_clc_msg_trail *)
135 			((u8 *)pclc + ntohs(pclc->hdr.length) - sizeof(*trl));
136 		break;
137 	case SMC_CLC_ACCEPT:
138 	case SMC_CLC_CONFIRM:
139 		clc_v2 = (struct smc_clc_msg_accept_confirm_v2 *)clcm;
140 		if (!smc_clc_msg_acc_conf_valid(clc_v2))
141 			return false;
142 		trl = (struct smc_clc_msg_trail *)
143 			((u8 *)clc_v2 + ntohs(clc_v2->hdr.length) -
144 							sizeof(*trl));
145 		break;
146 	case SMC_CLC_DECLINE:
147 		dclc = (struct smc_clc_msg_decline *)clcm;
148 		if (ntohs(dclc->hdr.length) != sizeof(*dclc))
149 			return false;
150 		trl = &dclc->trl;
151 		break;
152 	default:
153 		return false;
154 	}
155 	if (check_trl &&
156 	    memcmp(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
157 	    memcmp(trl->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
158 		return false;
159 	return true;
160 }
161 
162 /* find ipv4 addr on device and get the prefix len, fill CLC proposal msg */
163 static int smc_clc_prfx_set4_rcu(struct dst_entry *dst, __be32 ipv4,
164 				 struct smc_clc_msg_proposal_prefix *prop)
165 {
166 	struct in_device *in_dev = __in_dev_get_rcu(dst->dev);
167 	const struct in_ifaddr *ifa;
168 
169 	if (!in_dev)
170 		return -ENODEV;
171 
172 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
173 		if (!inet_ifa_match(ipv4, ifa))
174 			continue;
175 		prop->prefix_len = inet_mask_len(ifa->ifa_mask);
176 		prop->outgoing_subnet = ifa->ifa_address & ifa->ifa_mask;
177 		/* prop->ipv6_prefixes_cnt = 0; already done by memset before */
178 		return 0;
179 	}
180 	return -ENOENT;
181 }
182 
183 /* fill CLC proposal msg with ipv6 prefixes from device */
184 static int smc_clc_prfx_set6_rcu(struct dst_entry *dst,
185 				 struct smc_clc_msg_proposal_prefix *prop,
186 				 struct smc_clc_ipv6_prefix *ipv6_prfx)
187 {
188 #if IS_ENABLED(CONFIG_IPV6)
189 	struct inet6_dev *in6_dev = __in6_dev_get(dst->dev);
190 	struct inet6_ifaddr *ifa;
191 	int cnt = 0;
192 
193 	if (!in6_dev)
194 		return -ENODEV;
195 	/* use a maximum of 8 IPv6 prefixes from device */
196 	list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
197 		if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
198 			continue;
199 		ipv6_addr_prefix(&ipv6_prfx[cnt].prefix,
200 				 &ifa->addr, ifa->prefix_len);
201 		ipv6_prfx[cnt].prefix_len = ifa->prefix_len;
202 		cnt++;
203 		if (cnt == SMC_CLC_MAX_V6_PREFIX)
204 			break;
205 	}
206 	prop->ipv6_prefixes_cnt = cnt;
207 	if (cnt)
208 		return 0;
209 #endif
210 	return -ENOENT;
211 }
212 
213 /* retrieve and set prefixes in CLC proposal msg */
214 static int smc_clc_prfx_set(struct socket *clcsock,
215 			    struct smc_clc_msg_proposal_prefix *prop,
216 			    struct smc_clc_ipv6_prefix *ipv6_prfx)
217 {
218 	struct dst_entry *dst = sk_dst_get(clcsock->sk);
219 	struct sockaddr_storage addrs;
220 	struct sockaddr_in6 *addr6;
221 	struct sockaddr_in *addr;
222 	int rc = -ENOENT;
223 
224 	if (!dst) {
225 		rc = -ENOTCONN;
226 		goto out;
227 	}
228 	if (!dst->dev) {
229 		rc = -ENODEV;
230 		goto out_rel;
231 	}
232 	/* get address to which the internal TCP socket is bound */
233 	if (kernel_getsockname(clcsock, (struct sockaddr *)&addrs) < 0)
234 		goto out_rel;
235 	/* analyze IP specific data of net_device belonging to TCP socket */
236 	addr6 = (struct sockaddr_in6 *)&addrs;
237 	rcu_read_lock();
238 	if (addrs.ss_family == PF_INET) {
239 		/* IPv4 */
240 		addr = (struct sockaddr_in *)&addrs;
241 		rc = smc_clc_prfx_set4_rcu(dst, addr->sin_addr.s_addr, prop);
242 	} else if (ipv6_addr_v4mapped(&addr6->sin6_addr)) {
243 		/* mapped IPv4 address - peer is IPv4 only */
244 		rc = smc_clc_prfx_set4_rcu(dst, addr6->sin6_addr.s6_addr32[3],
245 					   prop);
246 	} else {
247 		/* IPv6 */
248 		rc = smc_clc_prfx_set6_rcu(dst, prop, ipv6_prfx);
249 	}
250 	rcu_read_unlock();
251 out_rel:
252 	dst_release(dst);
253 out:
254 	return rc;
255 }
256 
257 /* match ipv4 addrs of dev against addr in CLC proposal */
258 static int smc_clc_prfx_match4_rcu(struct net_device *dev,
259 				   struct smc_clc_msg_proposal_prefix *prop)
260 {
261 	struct in_device *in_dev = __in_dev_get_rcu(dev);
262 	const struct in_ifaddr *ifa;
263 
264 	if (!in_dev)
265 		return -ENODEV;
266 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
267 		if (prop->prefix_len == inet_mask_len(ifa->ifa_mask) &&
268 		    inet_ifa_match(prop->outgoing_subnet, ifa))
269 			return 0;
270 	}
271 
272 	return -ENOENT;
273 }
274 
275 /* match ipv6 addrs of dev against addrs in CLC proposal */
276 static int smc_clc_prfx_match6_rcu(struct net_device *dev,
277 				   struct smc_clc_msg_proposal_prefix *prop)
278 {
279 #if IS_ENABLED(CONFIG_IPV6)
280 	struct inet6_dev *in6_dev = __in6_dev_get(dev);
281 	struct smc_clc_ipv6_prefix *ipv6_prfx;
282 	struct inet6_ifaddr *ifa;
283 	int i, max;
284 
285 	if (!in6_dev)
286 		return -ENODEV;
287 	/* ipv6 prefix list starts behind smc_clc_msg_proposal_prefix */
288 	ipv6_prfx = (struct smc_clc_ipv6_prefix *)((u8 *)prop + sizeof(*prop));
289 	max = min_t(u8, prop->ipv6_prefixes_cnt, SMC_CLC_MAX_V6_PREFIX);
290 	list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
291 		if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
292 			continue;
293 		for (i = 0; i < max; i++) {
294 			if (ifa->prefix_len == ipv6_prfx[i].prefix_len &&
295 			    ipv6_prefix_equal(&ifa->addr, &ipv6_prfx[i].prefix,
296 					      ifa->prefix_len))
297 				return 0;
298 		}
299 	}
300 #endif
301 	return -ENOENT;
302 }
303 
304 /* check if proposed prefixes match one of our device prefixes */
305 int smc_clc_prfx_match(struct socket *clcsock,
306 		       struct smc_clc_msg_proposal_prefix *prop)
307 {
308 	struct dst_entry *dst = sk_dst_get(clcsock->sk);
309 	int rc;
310 
311 	if (!dst) {
312 		rc = -ENOTCONN;
313 		goto out;
314 	}
315 	if (!dst->dev) {
316 		rc = -ENODEV;
317 		goto out_rel;
318 	}
319 	rcu_read_lock();
320 	if (!prop->ipv6_prefixes_cnt)
321 		rc = smc_clc_prfx_match4_rcu(dst->dev, prop);
322 	else
323 		rc = smc_clc_prfx_match6_rcu(dst->dev, prop);
324 	rcu_read_unlock();
325 out_rel:
326 	dst_release(dst);
327 out:
328 	return rc;
329 }
330 
331 /* Wait for data on the tcp-socket, analyze received data
332  * Returns:
333  * 0 if success and it was not a decline that we received.
334  * SMC_CLC_DECL_REPLY if decline received for fallback w/o another decl send.
335  * clcsock error, -EINTR, -ECONNRESET, -EPROTO otherwise.
336  */
337 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
338 		     u8 expected_type, unsigned long timeout)
339 {
340 	long rcvtimeo = smc->clcsock->sk->sk_rcvtimeo;
341 	struct sock *clc_sk = smc->clcsock->sk;
342 	struct smc_clc_msg_hdr *clcm = buf;
343 	struct msghdr msg = {NULL, 0};
344 	int reason_code = 0;
345 	struct kvec vec = {buf, buflen};
346 	int len, datlen, recvlen;
347 	bool check_trl = true;
348 	int krflags;
349 
350 	/* peek the first few bytes to determine length of data to receive
351 	 * so we don't consume any subsequent CLC message or payload data
352 	 * in the TCP byte stream
353 	 */
354 	/*
355 	 * Caller must make sure that buflen is no less than
356 	 * sizeof(struct smc_clc_msg_hdr)
357 	 */
358 	krflags = MSG_PEEK | MSG_WAITALL;
359 	clc_sk->sk_rcvtimeo = timeout;
360 	iov_iter_kvec(&msg.msg_iter, READ, &vec, 1,
361 			sizeof(struct smc_clc_msg_hdr));
362 	len = sock_recvmsg(smc->clcsock, &msg, krflags);
363 	if (signal_pending(current)) {
364 		reason_code = -EINTR;
365 		clc_sk->sk_err = EINTR;
366 		smc->sk.sk_err = EINTR;
367 		goto out;
368 	}
369 	if (clc_sk->sk_err) {
370 		reason_code = -clc_sk->sk_err;
371 		if (clc_sk->sk_err == EAGAIN &&
372 		    expected_type == SMC_CLC_DECLINE)
373 			clc_sk->sk_err = 0; /* reset for fallback usage */
374 		else
375 			smc->sk.sk_err = clc_sk->sk_err;
376 		goto out;
377 	}
378 	if (!len) { /* peer has performed orderly shutdown */
379 		smc->sk.sk_err = ECONNRESET;
380 		reason_code = -ECONNRESET;
381 		goto out;
382 	}
383 	if (len < 0) {
384 		if (len != -EAGAIN || expected_type != SMC_CLC_DECLINE)
385 			smc->sk.sk_err = -len;
386 		reason_code = len;
387 		goto out;
388 	}
389 	datlen = ntohs(clcm->length);
390 	if ((len < sizeof(struct smc_clc_msg_hdr)) ||
391 	    (clcm->version < SMC_V1) ||
392 	    ((clcm->type != SMC_CLC_DECLINE) &&
393 	     (clcm->type != expected_type))) {
394 		smc->sk.sk_err = EPROTO;
395 		reason_code = -EPROTO;
396 		goto out;
397 	}
398 
399 	/* receive the complete CLC message */
400 	memset(&msg, 0, sizeof(struct msghdr));
401 	if (datlen > buflen) {
402 		check_trl = false;
403 		recvlen = buflen;
404 	} else {
405 		recvlen = datlen;
406 	}
407 	iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, recvlen);
408 	krflags = MSG_WAITALL;
409 	len = sock_recvmsg(smc->clcsock, &msg, krflags);
410 	if (len < recvlen || !smc_clc_msg_hdr_valid(clcm, check_trl)) {
411 		smc->sk.sk_err = EPROTO;
412 		reason_code = -EPROTO;
413 		goto out;
414 	}
415 	datlen -= len;
416 	while (datlen) {
417 		u8 tmp[SMC_CLC_RECV_BUF_LEN];
418 
419 		vec.iov_base = &tmp;
420 		vec.iov_len = SMC_CLC_RECV_BUF_LEN;
421 		/* receive remaining proposal message */
422 		recvlen = datlen > SMC_CLC_RECV_BUF_LEN ?
423 						SMC_CLC_RECV_BUF_LEN : datlen;
424 		iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, recvlen);
425 		len = sock_recvmsg(smc->clcsock, &msg, krflags);
426 		datlen -= len;
427 	}
428 	if (clcm->type == SMC_CLC_DECLINE) {
429 		struct smc_clc_msg_decline *dclc;
430 
431 		dclc = (struct smc_clc_msg_decline *)clcm;
432 		reason_code = SMC_CLC_DECL_PEERDECL;
433 		smc->peer_diagnosis = ntohl(dclc->peer_diagnosis);
434 		if (((struct smc_clc_msg_decline *)buf)->hdr.typev2 &
435 						SMC_FIRST_CONTACT_MASK) {
436 			smc->conn.lgr->sync_err = 1;
437 			smc_lgr_terminate_sched(smc->conn.lgr);
438 		}
439 	}
440 
441 out:
442 	clc_sk->sk_rcvtimeo = rcvtimeo;
443 	return reason_code;
444 }
445 
446 /* send CLC DECLINE message across internal TCP socket */
447 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info, u8 version)
448 {
449 	struct smc_clc_msg_decline dclc;
450 	struct msghdr msg;
451 	struct kvec vec;
452 	int len;
453 
454 	memset(&dclc, 0, sizeof(dclc));
455 	memcpy(dclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
456 	dclc.hdr.type = SMC_CLC_DECLINE;
457 	dclc.hdr.length = htons(sizeof(struct smc_clc_msg_decline));
458 	dclc.hdr.version = version;
459 	dclc.os_type = version == SMC_V1 ? 0 : SMC_CLC_OS_LINUX;
460 	dclc.hdr.typev2 = (peer_diag_info == SMC_CLC_DECL_SYNCERR) ?
461 						SMC_FIRST_CONTACT_MASK : 0;
462 	if ((!smc->conn.lgr || !smc->conn.lgr->is_smcd) &&
463 	    smc_ib_is_valid_local_systemid())
464 		memcpy(dclc.id_for_peer, local_systemid,
465 		       sizeof(local_systemid));
466 	dclc.peer_diagnosis = htonl(peer_diag_info);
467 	memcpy(dclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
468 
469 	memset(&msg, 0, sizeof(msg));
470 	vec.iov_base = &dclc;
471 	vec.iov_len = sizeof(struct smc_clc_msg_decline);
472 	len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
473 			     sizeof(struct smc_clc_msg_decline));
474 	if (len < 0 || len < sizeof(struct smc_clc_msg_decline))
475 		len = -EPROTO;
476 	return len > 0 ? 0 : len;
477 }
478 
479 /* send CLC PROPOSAL message across internal TCP socket */
480 int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini)
481 {
482 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
483 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
484 	struct smc_clc_msg_proposal *pclc_base;
485 	struct smc_clc_smcd_gid_chid *gidchids;
486 	struct smc_clc_msg_proposal_area *pclc;
487 	struct smc_clc_ipv6_prefix *ipv6_prfx;
488 	struct smc_clc_v2_extension *v2_ext;
489 	struct smc_clc_msg_smcd *pclc_smcd;
490 	struct smc_clc_msg_trail *trl;
491 	int len, i, plen, rc;
492 	int reason_code = 0;
493 	struct kvec vec[8];
494 	struct msghdr msg;
495 
496 	pclc = kzalloc(sizeof(*pclc), GFP_KERNEL);
497 	if (!pclc)
498 		return -ENOMEM;
499 
500 	pclc_base = &pclc->pclc_base;
501 	pclc_smcd = &pclc->pclc_smcd;
502 	pclc_prfx = &pclc->pclc_prfx;
503 	ipv6_prfx = pclc->pclc_prfx_ipv6;
504 	v2_ext = &pclc->pclc_v2_ext;
505 	smcd_v2_ext = &pclc->pclc_smcd_v2_ext;
506 	gidchids = pclc->pclc_gidchids;
507 	trl = &pclc->pclc_trl;
508 
509 	pclc_base->hdr.version = SMC_V2;
510 	pclc_base->hdr.typev1 = ini->smc_type_v1;
511 	pclc_base->hdr.typev2 = ini->smc_type_v2;
512 	plen = sizeof(*pclc_base) + sizeof(*pclc_smcd) + sizeof(*trl);
513 
514 	/* retrieve ip prefixes for CLC proposal msg */
515 	if (ini->smc_type_v1 != SMC_TYPE_N) {
516 		rc = smc_clc_prfx_set(smc->clcsock, pclc_prfx, ipv6_prfx);
517 		if (rc) {
518 			if (ini->smc_type_v2 == SMC_TYPE_N) {
519 				kfree(pclc);
520 				return SMC_CLC_DECL_CNFERR;
521 			}
522 			pclc_base->hdr.typev1 = SMC_TYPE_N;
523 		} else {
524 			pclc_base->iparea_offset = htons(sizeof(*pclc_smcd));
525 			plen += sizeof(*pclc_prfx) +
526 					pclc_prfx->ipv6_prefixes_cnt *
527 					sizeof(ipv6_prfx[0]);
528 		}
529 	}
530 
531 	/* build SMC Proposal CLC message */
532 	memcpy(pclc_base->hdr.eyecatcher, SMC_EYECATCHER,
533 	       sizeof(SMC_EYECATCHER));
534 	pclc_base->hdr.type = SMC_CLC_PROPOSAL;
535 	if (smcr_indicated(ini->smc_type_v1)) {
536 		/* add SMC-R specifics */
537 		memcpy(pclc_base->lcl.id_for_peer, local_systemid,
538 		       sizeof(local_systemid));
539 		memcpy(pclc_base->lcl.gid, ini->ib_gid, SMC_GID_SIZE);
540 		memcpy(pclc_base->lcl.mac, &ini->ib_dev->mac[ini->ib_port - 1],
541 		       ETH_ALEN);
542 	}
543 	if (smcd_indicated(ini->smc_type_v1)) {
544 		/* add SMC-D specifics */
545 		if (ini->ism_dev[0]) {
546 			pclc_smcd->ism.gid = htonll(ini->ism_dev[0]->local_gid);
547 			pclc_smcd->ism.chid =
548 				htons(smc_ism_get_chid(ini->ism_dev[0]));
549 		}
550 	}
551 	if (ini->smc_type_v2 == SMC_TYPE_N) {
552 		pclc_smcd->v2_ext_offset = 0;
553 	} else {
554 		u16 v2_ext_offset;
555 		u8 *eid = NULL;
556 
557 		v2_ext_offset = sizeof(*pclc_smcd) -
558 			offsetofend(struct smc_clc_msg_smcd, v2_ext_offset);
559 		if (ini->smc_type_v1 != SMC_TYPE_N)
560 			v2_ext_offset += sizeof(*pclc_prfx) +
561 						pclc_prfx->ipv6_prefixes_cnt *
562 						sizeof(ipv6_prfx[0]);
563 		pclc_smcd->v2_ext_offset = htons(v2_ext_offset);
564 		v2_ext->hdr.eid_cnt = 0;
565 		v2_ext->hdr.ism_gid_cnt = ini->ism_offered_cnt;
566 		v2_ext->hdr.flag.release = SMC_RELEASE;
567 		v2_ext->hdr.flag.seid = 1;
568 		v2_ext->hdr.smcd_v2_ext_offset = htons(sizeof(*v2_ext) -
569 				offsetofend(struct smc_clnt_opts_area_hdr,
570 					    smcd_v2_ext_offset) +
571 				v2_ext->hdr.eid_cnt * SMC_MAX_EID_LEN);
572 		if (ini->ism_dev[0])
573 			smc_ism_get_system_eid(ini->ism_dev[0], &eid);
574 		else
575 			smc_ism_get_system_eid(ini->ism_dev[1], &eid);
576 		if (eid)
577 			memcpy(smcd_v2_ext->system_eid, eid, SMC_MAX_EID_LEN);
578 		plen += sizeof(*v2_ext) + sizeof(*smcd_v2_ext);
579 		if (ini->ism_offered_cnt) {
580 			for (i = 1; i <= ini->ism_offered_cnt; i++) {
581 				gidchids[i - 1].gid =
582 					htonll(ini->ism_dev[i]->local_gid);
583 				gidchids[i - 1].chid =
584 					htons(smc_ism_get_chid(ini->ism_dev[i]));
585 			}
586 			plen += ini->ism_offered_cnt *
587 				sizeof(struct smc_clc_smcd_gid_chid);
588 		}
589 	}
590 	pclc_base->hdr.length = htons(plen);
591 	memcpy(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
592 
593 	/* send SMC Proposal CLC message */
594 	memset(&msg, 0, sizeof(msg));
595 	i = 0;
596 	vec[i].iov_base = pclc_base;
597 	vec[i++].iov_len = sizeof(*pclc_base);
598 	vec[i].iov_base = pclc_smcd;
599 	vec[i++].iov_len = sizeof(*pclc_smcd);
600 	if (ini->smc_type_v1 != SMC_TYPE_N) {
601 		vec[i].iov_base = pclc_prfx;
602 		vec[i++].iov_len = sizeof(*pclc_prfx);
603 		if (pclc_prfx->ipv6_prefixes_cnt > 0) {
604 			vec[i].iov_base = ipv6_prfx;
605 			vec[i++].iov_len = pclc_prfx->ipv6_prefixes_cnt *
606 					   sizeof(ipv6_prfx[0]);
607 		}
608 	}
609 	if (ini->smc_type_v2 != SMC_TYPE_N) {
610 		vec[i].iov_base = v2_ext;
611 		vec[i++].iov_len = sizeof(*v2_ext);
612 		vec[i].iov_base = smcd_v2_ext;
613 		vec[i++].iov_len = sizeof(*smcd_v2_ext);
614 		if (ini->ism_offered_cnt) {
615 			vec[i].iov_base = gidchids;
616 			vec[i++].iov_len = ini->ism_offered_cnt *
617 					sizeof(struct smc_clc_smcd_gid_chid);
618 		}
619 	}
620 	vec[i].iov_base = trl;
621 	vec[i++].iov_len = sizeof(*trl);
622 	/* due to the few bytes needed for clc-handshake this cannot block */
623 	len = kernel_sendmsg(smc->clcsock, &msg, vec, i, plen);
624 	if (len < 0) {
625 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
626 		reason_code = -smc->sk.sk_err;
627 	} else if (len < ntohs(pclc_base->hdr.length)) {
628 		reason_code = -ENETUNREACH;
629 		smc->sk.sk_err = -reason_code;
630 	}
631 
632 	kfree(pclc);
633 	return reason_code;
634 }
635 
636 /* build and send CLC CONFIRM / ACCEPT message */
637 static int smc_clc_send_confirm_accept(struct smc_sock *smc,
638 				       struct smc_clc_msg_accept_confirm_v2 *clc_v2,
639 				       int first_contact, u8 version)
640 {
641 	struct smc_connection *conn = &smc->conn;
642 	struct smc_clc_msg_accept_confirm *clc;
643 	struct smc_clc_first_contact_ext fce;
644 	struct smc_clc_msg_trail trl;
645 	struct kvec vec[3];
646 	struct msghdr msg;
647 	int i, len;
648 
649 	/* send SMC Confirm CLC msg */
650 	clc = (struct smc_clc_msg_accept_confirm *)clc_v2;
651 	clc->hdr.version = version;	/* SMC version */
652 	if (first_contact)
653 		clc->hdr.typev2 |= SMC_FIRST_CONTACT_MASK;
654 	if (conn->lgr->is_smcd) {
655 		/* SMC-D specific settings */
656 		memcpy(clc->hdr.eyecatcher, SMCD_EYECATCHER,
657 		       sizeof(SMCD_EYECATCHER));
658 		clc->hdr.typev1 = SMC_TYPE_D;
659 		clc->d0.gid = conn->lgr->smcd->local_gid;
660 		clc->d0.token = conn->rmb_desc->token;
661 		clc->d0.dmbe_size = conn->rmbe_size_short;
662 		clc->d0.dmbe_idx = 0;
663 		memcpy(&clc->d0.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
664 		if (version == SMC_V1) {
665 			clc->hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
666 		} else {
667 			u8 *eid = NULL;
668 
669 			clc_v2->chid = htons(smc_ism_get_chid(conn->lgr->smcd));
670 			smc_ism_get_system_eid(conn->lgr->smcd, &eid);
671 			if (eid)
672 				memcpy(clc_v2->eid, eid, SMC_MAX_EID_LEN);
673 			len = SMCD_CLC_ACCEPT_CONFIRM_LEN_V2;
674 			if (first_contact)
675 				smc_clc_fill_fce(&fce, &len);
676 			clc_v2->hdr.length = htons(len);
677 		}
678 		memcpy(trl.eyecatcher, SMCD_EYECATCHER,
679 		       sizeof(SMCD_EYECATCHER));
680 	} else {
681 		struct smc_link *link = conn->lnk;
682 
683 		/* SMC-R specific settings */
684 		link = conn->lnk;
685 		memcpy(clc->hdr.eyecatcher, SMC_EYECATCHER,
686 		       sizeof(SMC_EYECATCHER));
687 		clc->hdr.typev1 = SMC_TYPE_R;
688 		clc->hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
689 		memcpy(clc->r0.lcl.id_for_peer, local_systemid,
690 		       sizeof(local_systemid));
691 		memcpy(&clc->r0.lcl.gid, link->gid, SMC_GID_SIZE);
692 		memcpy(&clc->r0.lcl.mac, &link->smcibdev->mac[link->ibport - 1],
693 		       ETH_ALEN);
694 		hton24(clc->r0.qpn, link->roce_qp->qp_num);
695 		clc->r0.rmb_rkey =
696 			htonl(conn->rmb_desc->mr_rx[link->link_idx]->rkey);
697 		clc->r0.rmbe_idx = 1; /* for now: 1 RMB = 1 RMBE */
698 		clc->r0.rmbe_alert_token = htonl(conn->alert_token_local);
699 		switch (clc->hdr.type) {
700 		case SMC_CLC_ACCEPT:
701 			clc->r0.qp_mtu = link->path_mtu;
702 			break;
703 		case SMC_CLC_CONFIRM:
704 			clc->r0.qp_mtu = min(link->path_mtu, link->peer_mtu);
705 			break;
706 		}
707 		clc->r0.rmbe_size = conn->rmbe_size_short;
708 		clc->r0.rmb_dma_addr = cpu_to_be64((u64)sg_dma_address
709 				(conn->rmb_desc->sgt[link->link_idx].sgl));
710 		hton24(clc->r0.psn, link->psn_initial);
711 		memcpy(trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
712 	}
713 
714 	memset(&msg, 0, sizeof(msg));
715 	i = 0;
716 	vec[i].iov_base = clc_v2;
717 	if (version > SMC_V1)
718 		vec[i++].iov_len = SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 - sizeof(trl);
719 	else
720 		vec[i++].iov_len = (clc->hdr.typev1 == SMC_TYPE_D ?
721 						SMCD_CLC_ACCEPT_CONFIRM_LEN :
722 						SMCR_CLC_ACCEPT_CONFIRM_LEN) -
723 				   sizeof(trl);
724 	if (version > SMC_V1 && first_contact) {
725 		vec[i].iov_base = &fce;
726 		vec[i++].iov_len = sizeof(fce);
727 	}
728 	vec[i].iov_base = &trl;
729 	vec[i++].iov_len = sizeof(trl);
730 	return kernel_sendmsg(smc->clcsock, &msg, vec, 1,
731 			      ntohs(clc->hdr.length));
732 }
733 
734 /* send CLC CONFIRM message across internal TCP socket */
735 int smc_clc_send_confirm(struct smc_sock *smc, bool clnt_first_contact,
736 			 u8 version)
737 {
738 	struct smc_clc_msg_accept_confirm_v2 cclc_v2;
739 	int reason_code = 0;
740 	int len;
741 
742 	/* send SMC Confirm CLC msg */
743 	memset(&cclc_v2, 0, sizeof(cclc_v2));
744 	cclc_v2.hdr.type = SMC_CLC_CONFIRM;
745 	len = smc_clc_send_confirm_accept(smc, &cclc_v2, clnt_first_contact,
746 					  version);
747 	if (len < ntohs(cclc_v2.hdr.length)) {
748 		if (len >= 0) {
749 			reason_code = -ENETUNREACH;
750 			smc->sk.sk_err = -reason_code;
751 		} else {
752 			smc->sk.sk_err = smc->clcsock->sk->sk_err;
753 			reason_code = -smc->sk.sk_err;
754 		}
755 	}
756 	return reason_code;
757 }
758 
759 /* send CLC ACCEPT message across internal TCP socket */
760 int smc_clc_send_accept(struct smc_sock *new_smc, bool srv_first_contact,
761 			u8 version)
762 {
763 	struct smc_clc_msg_accept_confirm_v2 aclc_v2;
764 	int len;
765 
766 	memset(&aclc_v2, 0, sizeof(aclc_v2));
767 	aclc_v2.hdr.type = SMC_CLC_ACCEPT;
768 	len = smc_clc_send_confirm_accept(new_smc, &aclc_v2, srv_first_contact,
769 					  version);
770 	if (len < ntohs(aclc_v2.hdr.length))
771 		len = len >= 0 ? -EPROTO : -new_smc->clcsock->sk->sk_err;
772 
773 	return len > 0 ? 0 : len;
774 }
775 
776 void smc_clc_get_hostname(u8 **host)
777 {
778 	*host = &smc_hostname[0];
779 }
780 
781 void __init smc_clc_init(void)
782 {
783 	struct new_utsname *u;
784 
785 	memset(smc_hostname, _S, sizeof(smc_hostname)); /* ASCII blanks */
786 	u = utsname();
787 	memcpy(smc_hostname, u->nodename,
788 	       min_t(size_t, strlen(u->nodename), sizeof(smc_hostname)));
789 }
790