xref: /linux/net/smc/smc_clc.c (revision e0d53e4f7fd84cb41ece77c3f02c18699cc82736)
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 #include "smc_netlink.h"
30 
31 #define SMCR_CLC_ACCEPT_CONFIRM_LEN 68
32 #define SMCD_CLC_ACCEPT_CONFIRM_LEN 48
33 #define SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 78
34 #define SMCR_CLC_ACCEPT_CONFIRM_LEN_V2 108
35 #define SMC_CLC_RECV_BUF_LEN	100
36 
37 /* eye catcher "SMCR" EBCDIC for CLC messages */
38 static const char SMC_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xd9'};
39 /* eye catcher "SMCD" EBCDIC for CLC messages */
40 static const char SMCD_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xc4'};
41 
42 static u8 smc_hostname[SMC_MAX_HOSTNAME_LEN];
43 
44 struct smc_clc_eid_table {
45 	rwlock_t lock;
46 	struct list_head list;
47 	u8 ueid_cnt;
48 	u8 seid_enabled;
49 };
50 
51 static struct smc_clc_eid_table smc_clc_eid_table;
52 
53 struct smc_clc_eid_entry {
54 	struct list_head list;
55 	u8 eid[SMC_MAX_EID_LEN];
56 };
57 
58 /* The size of a user EID is 32 characters.
59  * Valid characters should be (single-byte character set) A-Z, 0-9, '.' and '-'.
60  * Blanks should only be used to pad to the expected size.
61  * First character must be alphanumeric.
62  */
63 static bool smc_clc_ueid_valid(char *ueid)
64 {
65 	char *end = ueid + SMC_MAX_EID_LEN;
66 
67 	while (--end >= ueid && isspace(*end))
68 		;
69 	if (end < ueid)
70 		return false;
71 	if (!isalnum(*ueid) || islower(*ueid))
72 		return false;
73 	while (ueid <= end) {
74 		if ((!isalnum(*ueid) || islower(*ueid)) && *ueid != '.' &&
75 		    *ueid != '-')
76 			return false;
77 		ueid++;
78 	}
79 	return true;
80 }
81 
82 static int smc_clc_ueid_add(char *ueid)
83 {
84 	struct smc_clc_eid_entry *new_ueid, *tmp_ueid;
85 	int rc;
86 
87 	if (!smc_clc_ueid_valid(ueid))
88 		return -EINVAL;
89 
90 	/* add a new ueid entry to the ueid table if there isn't one */
91 	new_ueid = kzalloc(sizeof(*new_ueid), GFP_KERNEL);
92 	if (!new_ueid)
93 		return -ENOMEM;
94 	memcpy(new_ueid->eid, ueid, SMC_MAX_EID_LEN);
95 
96 	write_lock(&smc_clc_eid_table.lock);
97 	if (smc_clc_eid_table.ueid_cnt >= SMC_MAX_UEID) {
98 		rc = -ERANGE;
99 		goto err_out;
100 	}
101 	list_for_each_entry(tmp_ueid, &smc_clc_eid_table.list, list) {
102 		if (!memcmp(tmp_ueid->eid, ueid, SMC_MAX_EID_LEN)) {
103 			rc = -EEXIST;
104 			goto err_out;
105 		}
106 	}
107 	list_add_tail(&new_ueid->list, &smc_clc_eid_table.list);
108 	smc_clc_eid_table.ueid_cnt++;
109 	write_unlock(&smc_clc_eid_table.lock);
110 	return 0;
111 
112 err_out:
113 	write_unlock(&smc_clc_eid_table.lock);
114 	kfree(new_ueid);
115 	return rc;
116 }
117 
118 int smc_clc_ueid_count(void)
119 {
120 	int count;
121 
122 	read_lock(&smc_clc_eid_table.lock);
123 	count = smc_clc_eid_table.ueid_cnt;
124 	read_unlock(&smc_clc_eid_table.lock);
125 
126 	return count;
127 }
128 
129 int smc_nl_add_ueid(struct sk_buff *skb, struct genl_info *info)
130 {
131 	struct nlattr *nla_ueid = info->attrs[SMC_NLA_EID_TABLE_ENTRY];
132 	char *ueid;
133 
134 	if (!nla_ueid || nla_len(nla_ueid) != SMC_MAX_EID_LEN + 1)
135 		return -EINVAL;
136 	ueid = (char *)nla_data(nla_ueid);
137 
138 	return smc_clc_ueid_add(ueid);
139 }
140 
141 /* remove one or all ueid entries from the table */
142 static int smc_clc_ueid_remove(char *ueid)
143 {
144 	struct smc_clc_eid_entry *lst_ueid, *tmp_ueid;
145 	int rc = -ENOENT;
146 
147 	/* remove table entry */
148 	write_lock(&smc_clc_eid_table.lock);
149 	list_for_each_entry_safe(lst_ueid, tmp_ueid, &smc_clc_eid_table.list,
150 				 list) {
151 		if (!ueid || !memcmp(lst_ueid->eid, ueid, SMC_MAX_EID_LEN)) {
152 			list_del(&lst_ueid->list);
153 			smc_clc_eid_table.ueid_cnt--;
154 			kfree(lst_ueid);
155 			rc = 0;
156 		}
157 	}
158 	if (!rc && !smc_clc_eid_table.ueid_cnt) {
159 		smc_clc_eid_table.seid_enabled = 1;
160 		rc = -EAGAIN;	/* indicate success and enabling of seid */
161 	}
162 	write_unlock(&smc_clc_eid_table.lock);
163 	return rc;
164 }
165 
166 int smc_nl_remove_ueid(struct sk_buff *skb, struct genl_info *info)
167 {
168 	struct nlattr *nla_ueid = info->attrs[SMC_NLA_EID_TABLE_ENTRY];
169 	char *ueid;
170 
171 	if (!nla_ueid || nla_len(nla_ueid) != SMC_MAX_EID_LEN + 1)
172 		return -EINVAL;
173 	ueid = (char *)nla_data(nla_ueid);
174 
175 	return smc_clc_ueid_remove(ueid);
176 }
177 
178 int smc_nl_flush_ueid(struct sk_buff *skb, struct genl_info *info)
179 {
180 	smc_clc_ueid_remove(NULL);
181 	return 0;
182 }
183 
184 static int smc_nl_ueid_dumpinfo(struct sk_buff *skb, u32 portid, u32 seq,
185 				u32 flags, char *ueid)
186 {
187 	char ueid_str[SMC_MAX_EID_LEN + 1];
188 	void *hdr;
189 
190 	hdr = genlmsg_put(skb, portid, seq, &smc_gen_nl_family,
191 			  flags, SMC_NETLINK_DUMP_UEID);
192 	if (!hdr)
193 		return -ENOMEM;
194 	memcpy(ueid_str, ueid, SMC_MAX_EID_LEN);
195 	ueid_str[SMC_MAX_EID_LEN] = 0;
196 	if (nla_put_string(skb, SMC_NLA_EID_TABLE_ENTRY, ueid_str)) {
197 		genlmsg_cancel(skb, hdr);
198 		return -EMSGSIZE;
199 	}
200 	genlmsg_end(skb, hdr);
201 	return 0;
202 }
203 
204 static int _smc_nl_ueid_dump(struct sk_buff *skb, u32 portid, u32 seq,
205 			     int start_idx)
206 {
207 	struct smc_clc_eid_entry *lst_ueid;
208 	int idx = 0;
209 
210 	read_lock(&smc_clc_eid_table.lock);
211 	list_for_each_entry(lst_ueid, &smc_clc_eid_table.list, list) {
212 		if (idx++ < start_idx)
213 			continue;
214 		if (smc_nl_ueid_dumpinfo(skb, portid, seq, NLM_F_MULTI,
215 					 lst_ueid->eid)) {
216 			--idx;
217 			break;
218 		}
219 	}
220 	read_unlock(&smc_clc_eid_table.lock);
221 	return idx;
222 }
223 
224 int smc_nl_dump_ueid(struct sk_buff *skb, struct netlink_callback *cb)
225 {
226 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
227 	int idx;
228 
229 	idx = _smc_nl_ueid_dump(skb, NETLINK_CB(cb->skb).portid,
230 				cb->nlh->nlmsg_seq, cb_ctx->pos[0]);
231 
232 	cb_ctx->pos[0] = idx;
233 	return skb->len;
234 }
235 
236 int smc_nl_dump_seid(struct sk_buff *skb, struct netlink_callback *cb)
237 {
238 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
239 	char seid_str[SMC_MAX_EID_LEN + 1];
240 	u8 seid_enabled;
241 	void *hdr;
242 	u8 *seid;
243 
244 	if (cb_ctx->pos[0])
245 		return skb->len;
246 
247 	hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
248 			  &smc_gen_nl_family, NLM_F_MULTI,
249 			  SMC_NETLINK_DUMP_SEID);
250 	if (!hdr)
251 		return -ENOMEM;
252 	if (!smc_ism_is_v2_capable())
253 		goto end;
254 
255 	smc_ism_get_system_eid(&seid);
256 	memcpy(seid_str, seid, SMC_MAX_EID_LEN);
257 	seid_str[SMC_MAX_EID_LEN] = 0;
258 	if (nla_put_string(skb, SMC_NLA_SEID_ENTRY, seid_str))
259 		goto err;
260 	read_lock(&smc_clc_eid_table.lock);
261 	seid_enabled = smc_clc_eid_table.seid_enabled;
262 	read_unlock(&smc_clc_eid_table.lock);
263 	if (nla_put_u8(skb, SMC_NLA_SEID_ENABLED, seid_enabled))
264 		goto err;
265 end:
266 	genlmsg_end(skb, hdr);
267 	cb_ctx->pos[0]++;
268 	return skb->len;
269 err:
270 	genlmsg_cancel(skb, hdr);
271 	return -EMSGSIZE;
272 }
273 
274 int smc_nl_enable_seid(struct sk_buff *skb, struct genl_info *info)
275 {
276 	write_lock(&smc_clc_eid_table.lock);
277 	smc_clc_eid_table.seid_enabled = 1;
278 	write_unlock(&smc_clc_eid_table.lock);
279 	return 0;
280 }
281 
282 int smc_nl_disable_seid(struct sk_buff *skb, struct genl_info *info)
283 {
284 	int rc = 0;
285 
286 	write_lock(&smc_clc_eid_table.lock);
287 	if (!smc_clc_eid_table.ueid_cnt)
288 		rc = -ENOENT;
289 	else
290 		smc_clc_eid_table.seid_enabled = 0;
291 	write_unlock(&smc_clc_eid_table.lock);
292 	return rc;
293 }
294 
295 static bool _smc_clc_match_ueid(u8 *peer_ueid)
296 {
297 	struct smc_clc_eid_entry *tmp_ueid;
298 
299 	list_for_each_entry(tmp_ueid, &smc_clc_eid_table.list, list) {
300 		if (!memcmp(tmp_ueid->eid, peer_ueid, SMC_MAX_EID_LEN))
301 			return true;
302 	}
303 	return false;
304 }
305 
306 bool smc_clc_match_eid(u8 *negotiated_eid,
307 		       struct smc_clc_v2_extension *smc_v2_ext,
308 		       u8 *peer_eid, u8 *local_eid)
309 {
310 	bool match = false;
311 	int i;
312 
313 	negotiated_eid[0] = 0;
314 	read_lock(&smc_clc_eid_table.lock);
315 	if (peer_eid && local_eid &&
316 	    smc_clc_eid_table.seid_enabled &&
317 	    smc_v2_ext->hdr.flag.seid &&
318 	    !memcmp(peer_eid, local_eid, SMC_MAX_EID_LEN)) {
319 		memcpy(negotiated_eid, peer_eid, SMC_MAX_EID_LEN);
320 		match = true;
321 		goto out;
322 	}
323 
324 	for (i = 0; i < smc_v2_ext->hdr.eid_cnt; i++) {
325 		if (_smc_clc_match_ueid(smc_v2_ext->user_eids[i])) {
326 			memcpy(negotiated_eid, smc_v2_ext->user_eids[i],
327 			       SMC_MAX_EID_LEN);
328 			match = true;
329 			goto out;
330 		}
331 	}
332 out:
333 	read_unlock(&smc_clc_eid_table.lock);
334 	return match;
335 }
336 
337 /* check arriving CLC proposal */
338 static bool smc_clc_msg_prop_valid(struct smc_clc_msg_proposal *pclc)
339 {
340 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
341 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
342 	struct smc_clc_msg_hdr *hdr = &pclc->hdr;
343 	struct smc_clc_v2_extension *v2_ext;
344 
345 	v2_ext = smc_get_clc_v2_ext(pclc);
346 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
347 	if (hdr->version == SMC_V1) {
348 		if (hdr->typev1 == SMC_TYPE_N)
349 			return false;
350 		if (ntohs(hdr->length) !=
351 			sizeof(*pclc) + ntohs(pclc->iparea_offset) +
352 			sizeof(*pclc_prfx) +
353 			pclc_prfx->ipv6_prefixes_cnt *
354 				sizeof(struct smc_clc_ipv6_prefix) +
355 			sizeof(struct smc_clc_msg_trail))
356 			return false;
357 	} else {
358 		if (ntohs(hdr->length) !=
359 			sizeof(*pclc) +
360 			sizeof(struct smc_clc_msg_smcd) +
361 			(hdr->typev1 != SMC_TYPE_N ?
362 				sizeof(*pclc_prfx) +
363 				pclc_prfx->ipv6_prefixes_cnt *
364 				sizeof(struct smc_clc_ipv6_prefix) : 0) +
365 			(hdr->typev2 != SMC_TYPE_N ?
366 				sizeof(*v2_ext) +
367 				v2_ext->hdr.eid_cnt * SMC_MAX_EID_LEN : 0) +
368 			(smcd_indicated(hdr->typev2) ?
369 				sizeof(*smcd_v2_ext) + v2_ext->hdr.ism_gid_cnt *
370 					sizeof(struct smc_clc_smcd_gid_chid) :
371 				0) +
372 			sizeof(struct smc_clc_msg_trail))
373 			return false;
374 	}
375 	return true;
376 }
377 
378 /* check arriving CLC accept or confirm */
379 static bool
380 smc_clc_msg_acc_conf_valid(struct smc_clc_msg_accept_confirm_v2 *clc_v2)
381 {
382 	struct smc_clc_msg_hdr *hdr = &clc_v2->hdr;
383 
384 	if (hdr->typev1 != SMC_TYPE_R && hdr->typev1 != SMC_TYPE_D)
385 		return false;
386 	if (hdr->version == SMC_V1) {
387 		if ((hdr->typev1 == SMC_TYPE_R &&
388 		     ntohs(hdr->length) != SMCR_CLC_ACCEPT_CONFIRM_LEN) ||
389 		    (hdr->typev1 == SMC_TYPE_D &&
390 		     ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN))
391 			return false;
392 	} else {
393 		if (hdr->typev1 == SMC_TYPE_D &&
394 		    ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 &&
395 		    (ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 +
396 				sizeof(struct smc_clc_first_contact_ext)))
397 			return false;
398 		if (hdr->typev1 == SMC_TYPE_R &&
399 		    ntohs(hdr->length) < SMCR_CLC_ACCEPT_CONFIRM_LEN_V2)
400 			return false;
401 	}
402 	return true;
403 }
404 
405 /* check arriving CLC decline */
406 static bool
407 smc_clc_msg_decl_valid(struct smc_clc_msg_decline *dclc)
408 {
409 	struct smc_clc_msg_hdr *hdr = &dclc->hdr;
410 
411 	if (hdr->typev1 != SMC_TYPE_R && hdr->typev1 != SMC_TYPE_D)
412 		return false;
413 	if (hdr->version == SMC_V1) {
414 		if (ntohs(hdr->length) != sizeof(struct smc_clc_msg_decline))
415 			return false;
416 	} else {
417 		if (ntohs(hdr->length) != sizeof(struct smc_clc_msg_decline_v2))
418 			return false;
419 	}
420 	return true;
421 }
422 
423 static void smc_clc_fill_fce(struct smc_clc_first_contact_ext *fce, int *len)
424 {
425 	memset(fce, 0, sizeof(*fce));
426 	fce->os_type = SMC_CLC_OS_LINUX;
427 	fce->release = SMC_RELEASE;
428 	memcpy(fce->hostname, smc_hostname, sizeof(smc_hostname));
429 	(*len) += sizeof(*fce);
430 }
431 
432 /* check if received message has a correct header length and contains valid
433  * heading and trailing eyecatchers
434  */
435 static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm, bool check_trl)
436 {
437 	struct smc_clc_msg_accept_confirm_v2 *clc_v2;
438 	struct smc_clc_msg_proposal *pclc;
439 	struct smc_clc_msg_decline *dclc;
440 	struct smc_clc_msg_trail *trl;
441 
442 	if (memcmp(clcm->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
443 	    memcmp(clcm->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
444 		return false;
445 	switch (clcm->type) {
446 	case SMC_CLC_PROPOSAL:
447 		pclc = (struct smc_clc_msg_proposal *)clcm;
448 		if (!smc_clc_msg_prop_valid(pclc))
449 			return false;
450 		trl = (struct smc_clc_msg_trail *)
451 			((u8 *)pclc + ntohs(pclc->hdr.length) - sizeof(*trl));
452 		break;
453 	case SMC_CLC_ACCEPT:
454 	case SMC_CLC_CONFIRM:
455 		clc_v2 = (struct smc_clc_msg_accept_confirm_v2 *)clcm;
456 		if (!smc_clc_msg_acc_conf_valid(clc_v2))
457 			return false;
458 		trl = (struct smc_clc_msg_trail *)
459 			((u8 *)clc_v2 + ntohs(clc_v2->hdr.length) -
460 							sizeof(*trl));
461 		break;
462 	case SMC_CLC_DECLINE:
463 		dclc = (struct smc_clc_msg_decline *)clcm;
464 		if (!smc_clc_msg_decl_valid(dclc))
465 			return false;
466 		check_trl = false;
467 		break;
468 	default:
469 		return false;
470 	}
471 	if (check_trl &&
472 	    memcmp(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
473 	    memcmp(trl->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
474 		return false;
475 	return true;
476 }
477 
478 /* find ipv4 addr on device and get the prefix len, fill CLC proposal msg */
479 static int smc_clc_prfx_set4_rcu(struct dst_entry *dst, __be32 ipv4,
480 				 struct smc_clc_msg_proposal_prefix *prop)
481 {
482 	struct in_device *in_dev = __in_dev_get_rcu(dst->dev);
483 	const struct in_ifaddr *ifa;
484 
485 	if (!in_dev)
486 		return -ENODEV;
487 
488 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
489 		if (!inet_ifa_match(ipv4, ifa))
490 			continue;
491 		prop->prefix_len = inet_mask_len(ifa->ifa_mask);
492 		prop->outgoing_subnet = ifa->ifa_address & ifa->ifa_mask;
493 		/* prop->ipv6_prefixes_cnt = 0; already done by memset before */
494 		return 0;
495 	}
496 	return -ENOENT;
497 }
498 
499 /* fill CLC proposal msg with ipv6 prefixes from device */
500 static int smc_clc_prfx_set6_rcu(struct dst_entry *dst,
501 				 struct smc_clc_msg_proposal_prefix *prop,
502 				 struct smc_clc_ipv6_prefix *ipv6_prfx)
503 {
504 #if IS_ENABLED(CONFIG_IPV6)
505 	struct inet6_dev *in6_dev = __in6_dev_get(dst->dev);
506 	struct inet6_ifaddr *ifa;
507 	int cnt = 0;
508 
509 	if (!in6_dev)
510 		return -ENODEV;
511 	/* use a maximum of 8 IPv6 prefixes from device */
512 	list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
513 		if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
514 			continue;
515 		ipv6_addr_prefix(&ipv6_prfx[cnt].prefix,
516 				 &ifa->addr, ifa->prefix_len);
517 		ipv6_prfx[cnt].prefix_len = ifa->prefix_len;
518 		cnt++;
519 		if (cnt == SMC_CLC_MAX_V6_PREFIX)
520 			break;
521 	}
522 	prop->ipv6_prefixes_cnt = cnt;
523 	if (cnt)
524 		return 0;
525 #endif
526 	return -ENOENT;
527 }
528 
529 /* retrieve and set prefixes in CLC proposal msg */
530 static int smc_clc_prfx_set(struct socket *clcsock,
531 			    struct smc_clc_msg_proposal_prefix *prop,
532 			    struct smc_clc_ipv6_prefix *ipv6_prfx)
533 {
534 	struct dst_entry *dst = sk_dst_get(clcsock->sk);
535 	struct sockaddr_storage addrs;
536 	struct sockaddr_in6 *addr6;
537 	struct sockaddr_in *addr;
538 	int rc = -ENOENT;
539 
540 	if (!dst) {
541 		rc = -ENOTCONN;
542 		goto out;
543 	}
544 	if (!dst->dev) {
545 		rc = -ENODEV;
546 		goto out_rel;
547 	}
548 	/* get address to which the internal TCP socket is bound */
549 	if (kernel_getsockname(clcsock, (struct sockaddr *)&addrs) < 0)
550 		goto out_rel;
551 	/* analyze IP specific data of net_device belonging to TCP socket */
552 	addr6 = (struct sockaddr_in6 *)&addrs;
553 	rcu_read_lock();
554 	if (addrs.ss_family == PF_INET) {
555 		/* IPv4 */
556 		addr = (struct sockaddr_in *)&addrs;
557 		rc = smc_clc_prfx_set4_rcu(dst, addr->sin_addr.s_addr, prop);
558 	} else if (ipv6_addr_v4mapped(&addr6->sin6_addr)) {
559 		/* mapped IPv4 address - peer is IPv4 only */
560 		rc = smc_clc_prfx_set4_rcu(dst, addr6->sin6_addr.s6_addr32[3],
561 					   prop);
562 	} else {
563 		/* IPv6 */
564 		rc = smc_clc_prfx_set6_rcu(dst, prop, ipv6_prfx);
565 	}
566 	rcu_read_unlock();
567 out_rel:
568 	dst_release(dst);
569 out:
570 	return rc;
571 }
572 
573 /* match ipv4 addrs of dev against addr in CLC proposal */
574 static int smc_clc_prfx_match4_rcu(struct net_device *dev,
575 				   struct smc_clc_msg_proposal_prefix *prop)
576 {
577 	struct in_device *in_dev = __in_dev_get_rcu(dev);
578 	const struct in_ifaddr *ifa;
579 
580 	if (!in_dev)
581 		return -ENODEV;
582 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
583 		if (prop->prefix_len == inet_mask_len(ifa->ifa_mask) &&
584 		    inet_ifa_match(prop->outgoing_subnet, ifa))
585 			return 0;
586 	}
587 
588 	return -ENOENT;
589 }
590 
591 /* match ipv6 addrs of dev against addrs in CLC proposal */
592 static int smc_clc_prfx_match6_rcu(struct net_device *dev,
593 				   struct smc_clc_msg_proposal_prefix *prop)
594 {
595 #if IS_ENABLED(CONFIG_IPV6)
596 	struct inet6_dev *in6_dev = __in6_dev_get(dev);
597 	struct smc_clc_ipv6_prefix *ipv6_prfx;
598 	struct inet6_ifaddr *ifa;
599 	int i, max;
600 
601 	if (!in6_dev)
602 		return -ENODEV;
603 	/* ipv6 prefix list starts behind smc_clc_msg_proposal_prefix */
604 	ipv6_prfx = (struct smc_clc_ipv6_prefix *)((u8 *)prop + sizeof(*prop));
605 	max = min_t(u8, prop->ipv6_prefixes_cnt, SMC_CLC_MAX_V6_PREFIX);
606 	list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
607 		if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
608 			continue;
609 		for (i = 0; i < max; i++) {
610 			if (ifa->prefix_len == ipv6_prfx[i].prefix_len &&
611 			    ipv6_prefix_equal(&ifa->addr, &ipv6_prfx[i].prefix,
612 					      ifa->prefix_len))
613 				return 0;
614 		}
615 	}
616 #endif
617 	return -ENOENT;
618 }
619 
620 /* check if proposed prefixes match one of our device prefixes */
621 int smc_clc_prfx_match(struct socket *clcsock,
622 		       struct smc_clc_msg_proposal_prefix *prop)
623 {
624 	struct dst_entry *dst = sk_dst_get(clcsock->sk);
625 	int rc;
626 
627 	if (!dst) {
628 		rc = -ENOTCONN;
629 		goto out;
630 	}
631 	if (!dst->dev) {
632 		rc = -ENODEV;
633 		goto out_rel;
634 	}
635 	rcu_read_lock();
636 	if (!prop->ipv6_prefixes_cnt)
637 		rc = smc_clc_prfx_match4_rcu(dst->dev, prop);
638 	else
639 		rc = smc_clc_prfx_match6_rcu(dst->dev, prop);
640 	rcu_read_unlock();
641 out_rel:
642 	dst_release(dst);
643 out:
644 	return rc;
645 }
646 
647 /* Wait for data on the tcp-socket, analyze received data
648  * Returns:
649  * 0 if success and it was not a decline that we received.
650  * SMC_CLC_DECL_REPLY if decline received for fallback w/o another decl send.
651  * clcsock error, -EINTR, -ECONNRESET, -EPROTO otherwise.
652  */
653 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
654 		     u8 expected_type, unsigned long timeout)
655 {
656 	long rcvtimeo = smc->clcsock->sk->sk_rcvtimeo;
657 	struct sock *clc_sk = smc->clcsock->sk;
658 	struct smc_clc_msg_hdr *clcm = buf;
659 	struct msghdr msg = {NULL, 0};
660 	int reason_code = 0;
661 	struct kvec vec = {buf, buflen};
662 	int len, datlen, recvlen;
663 	bool check_trl = true;
664 	int krflags;
665 
666 	/* peek the first few bytes to determine length of data to receive
667 	 * so we don't consume any subsequent CLC message or payload data
668 	 * in the TCP byte stream
669 	 */
670 	/*
671 	 * Caller must make sure that buflen is no less than
672 	 * sizeof(struct smc_clc_msg_hdr)
673 	 */
674 	krflags = MSG_PEEK | MSG_WAITALL;
675 	clc_sk->sk_rcvtimeo = timeout;
676 	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &vec, 1,
677 			sizeof(struct smc_clc_msg_hdr));
678 	len = sock_recvmsg(smc->clcsock, &msg, krflags);
679 	if (signal_pending(current)) {
680 		reason_code = -EINTR;
681 		clc_sk->sk_err = EINTR;
682 		smc->sk.sk_err = EINTR;
683 		goto out;
684 	}
685 	if (clc_sk->sk_err) {
686 		reason_code = -clc_sk->sk_err;
687 		if (clc_sk->sk_err == EAGAIN &&
688 		    expected_type == SMC_CLC_DECLINE)
689 			clc_sk->sk_err = 0; /* reset for fallback usage */
690 		else
691 			smc->sk.sk_err = clc_sk->sk_err;
692 		goto out;
693 	}
694 	if (!len) { /* peer has performed orderly shutdown */
695 		smc->sk.sk_err = ECONNRESET;
696 		reason_code = -ECONNRESET;
697 		goto out;
698 	}
699 	if (len < 0) {
700 		if (len != -EAGAIN || expected_type != SMC_CLC_DECLINE)
701 			smc->sk.sk_err = -len;
702 		reason_code = len;
703 		goto out;
704 	}
705 	datlen = ntohs(clcm->length);
706 	if ((len < sizeof(struct smc_clc_msg_hdr)) ||
707 	    (clcm->version < SMC_V1) ||
708 	    ((clcm->type != SMC_CLC_DECLINE) &&
709 	     (clcm->type != expected_type))) {
710 		smc->sk.sk_err = EPROTO;
711 		reason_code = -EPROTO;
712 		goto out;
713 	}
714 
715 	/* receive the complete CLC message */
716 	memset(&msg, 0, sizeof(struct msghdr));
717 	if (datlen > buflen) {
718 		check_trl = false;
719 		recvlen = buflen;
720 	} else {
721 		recvlen = datlen;
722 	}
723 	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &vec, 1, recvlen);
724 	krflags = MSG_WAITALL;
725 	len = sock_recvmsg(smc->clcsock, &msg, krflags);
726 	if (len < recvlen || !smc_clc_msg_hdr_valid(clcm, check_trl)) {
727 		smc->sk.sk_err = EPROTO;
728 		reason_code = -EPROTO;
729 		goto out;
730 	}
731 	datlen -= len;
732 	while (datlen) {
733 		u8 tmp[SMC_CLC_RECV_BUF_LEN];
734 
735 		vec.iov_base = &tmp;
736 		vec.iov_len = SMC_CLC_RECV_BUF_LEN;
737 		/* receive remaining proposal message */
738 		recvlen = datlen > SMC_CLC_RECV_BUF_LEN ?
739 						SMC_CLC_RECV_BUF_LEN : datlen;
740 		iov_iter_kvec(&msg.msg_iter, ITER_DEST, &vec, 1, recvlen);
741 		len = sock_recvmsg(smc->clcsock, &msg, krflags);
742 		datlen -= len;
743 	}
744 	if (clcm->type == SMC_CLC_DECLINE) {
745 		struct smc_clc_msg_decline *dclc;
746 
747 		dclc = (struct smc_clc_msg_decline *)clcm;
748 		reason_code = SMC_CLC_DECL_PEERDECL;
749 		smc->peer_diagnosis = ntohl(dclc->peer_diagnosis);
750 		if (((struct smc_clc_msg_decline *)buf)->hdr.typev2 &
751 						SMC_FIRST_CONTACT_MASK) {
752 			smc->conn.lgr->sync_err = 1;
753 			smc_lgr_terminate_sched(smc->conn.lgr);
754 		}
755 	}
756 
757 out:
758 	clc_sk->sk_rcvtimeo = rcvtimeo;
759 	return reason_code;
760 }
761 
762 /* send CLC DECLINE message across internal TCP socket */
763 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info, u8 version)
764 {
765 	struct smc_clc_msg_decline *dclc_v1;
766 	struct smc_clc_msg_decline_v2 dclc;
767 	struct msghdr msg;
768 	int len, send_len;
769 	struct kvec vec;
770 
771 	dclc_v1 = (struct smc_clc_msg_decline *)&dclc;
772 	memset(&dclc, 0, sizeof(dclc));
773 	memcpy(dclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
774 	dclc.hdr.type = SMC_CLC_DECLINE;
775 	dclc.hdr.version = version;
776 	dclc.os_type = version == SMC_V1 ? 0 : SMC_CLC_OS_LINUX;
777 	dclc.hdr.typev2 = (peer_diag_info == SMC_CLC_DECL_SYNCERR) ?
778 						SMC_FIRST_CONTACT_MASK : 0;
779 	if ((!smc_conn_lgr_valid(&smc->conn) || !smc->conn.lgr->is_smcd) &&
780 	    smc_ib_is_valid_local_systemid())
781 		memcpy(dclc.id_for_peer, local_systemid,
782 		       sizeof(local_systemid));
783 	dclc.peer_diagnosis = htonl(peer_diag_info);
784 	if (version == SMC_V1) {
785 		memcpy(dclc_v1->trl.eyecatcher, SMC_EYECATCHER,
786 		       sizeof(SMC_EYECATCHER));
787 		send_len = sizeof(*dclc_v1);
788 	} else {
789 		memcpy(dclc.trl.eyecatcher, SMC_EYECATCHER,
790 		       sizeof(SMC_EYECATCHER));
791 		send_len = sizeof(dclc);
792 	}
793 	dclc.hdr.length = htons(send_len);
794 
795 	memset(&msg, 0, sizeof(msg));
796 	vec.iov_base = &dclc;
797 	vec.iov_len = send_len;
798 	len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1, send_len);
799 	if (len < 0 || len < send_len)
800 		len = -EPROTO;
801 	return len > 0 ? 0 : len;
802 }
803 
804 /* send CLC PROPOSAL message across internal TCP socket */
805 int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini)
806 {
807 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
808 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
809 	struct smc_clc_msg_proposal *pclc_base;
810 	struct smc_clc_smcd_gid_chid *gidchids;
811 	struct smc_clc_msg_proposal_area *pclc;
812 	struct smc_clc_ipv6_prefix *ipv6_prfx;
813 	struct smc_clc_v2_extension *v2_ext;
814 	struct smc_clc_msg_smcd *pclc_smcd;
815 	struct smc_clc_msg_trail *trl;
816 	struct smcd_dev *smcd;
817 	int len, i, plen, rc;
818 	int reason_code = 0;
819 	struct kvec vec[8];
820 	struct msghdr msg;
821 
822 	pclc = kzalloc(sizeof(*pclc), GFP_KERNEL);
823 	if (!pclc)
824 		return -ENOMEM;
825 
826 	pclc_base = &pclc->pclc_base;
827 	pclc_smcd = &pclc->pclc_smcd;
828 	pclc_prfx = &pclc->pclc_prfx;
829 	ipv6_prfx = pclc->pclc_prfx_ipv6;
830 	v2_ext = &pclc->pclc_v2_ext;
831 	smcd_v2_ext = &pclc->pclc_smcd_v2_ext;
832 	gidchids = pclc->pclc_gidchids;
833 	trl = &pclc->pclc_trl;
834 
835 	pclc_base->hdr.version = SMC_V2;
836 	pclc_base->hdr.typev1 = ini->smc_type_v1;
837 	pclc_base->hdr.typev2 = ini->smc_type_v2;
838 	plen = sizeof(*pclc_base) + sizeof(*pclc_smcd) + sizeof(*trl);
839 
840 	/* retrieve ip prefixes for CLC proposal msg */
841 	if (ini->smc_type_v1 != SMC_TYPE_N) {
842 		rc = smc_clc_prfx_set(smc->clcsock, pclc_prfx, ipv6_prfx);
843 		if (rc) {
844 			if (ini->smc_type_v2 == SMC_TYPE_N) {
845 				kfree(pclc);
846 				return SMC_CLC_DECL_CNFERR;
847 			}
848 			pclc_base->hdr.typev1 = SMC_TYPE_N;
849 		} else {
850 			pclc_base->iparea_offset = htons(sizeof(*pclc_smcd));
851 			plen += sizeof(*pclc_prfx) +
852 					pclc_prfx->ipv6_prefixes_cnt *
853 					sizeof(ipv6_prfx[0]);
854 		}
855 	}
856 
857 	/* build SMC Proposal CLC message */
858 	memcpy(pclc_base->hdr.eyecatcher, SMC_EYECATCHER,
859 	       sizeof(SMC_EYECATCHER));
860 	pclc_base->hdr.type = SMC_CLC_PROPOSAL;
861 	if (smcr_indicated(ini->smc_type_v1)) {
862 		/* add SMC-R specifics */
863 		memcpy(pclc_base->lcl.id_for_peer, local_systemid,
864 		       sizeof(local_systemid));
865 		memcpy(pclc_base->lcl.gid, ini->ib_gid, SMC_GID_SIZE);
866 		memcpy(pclc_base->lcl.mac, &ini->ib_dev->mac[ini->ib_port - 1],
867 		       ETH_ALEN);
868 	}
869 	if (smcd_indicated(ini->smc_type_v1)) {
870 		/* add SMC-D specifics */
871 		if (ini->ism_dev[0]) {
872 			smcd = ini->ism_dev[0];
873 			pclc_smcd->ism.gid =
874 				htonll(smcd->ops->get_local_gid(smcd));
875 			pclc_smcd->ism.chid =
876 				htons(smc_ism_get_chid(ini->ism_dev[0]));
877 		}
878 	}
879 	if (ini->smc_type_v2 == SMC_TYPE_N) {
880 		pclc_smcd->v2_ext_offset = 0;
881 	} else {
882 		struct smc_clc_eid_entry *ueident;
883 		u16 v2_ext_offset;
884 
885 		v2_ext->hdr.flag.release = SMC_RELEASE;
886 		v2_ext_offset = sizeof(*pclc_smcd) -
887 			offsetofend(struct smc_clc_msg_smcd, v2_ext_offset);
888 		if (ini->smc_type_v1 != SMC_TYPE_N)
889 			v2_ext_offset += sizeof(*pclc_prfx) +
890 						pclc_prfx->ipv6_prefixes_cnt *
891 						sizeof(ipv6_prfx[0]);
892 		pclc_smcd->v2_ext_offset = htons(v2_ext_offset);
893 		plen += sizeof(*v2_ext);
894 
895 		read_lock(&smc_clc_eid_table.lock);
896 		v2_ext->hdr.eid_cnt = smc_clc_eid_table.ueid_cnt;
897 		plen += smc_clc_eid_table.ueid_cnt * SMC_MAX_EID_LEN;
898 		i = 0;
899 		list_for_each_entry(ueident, &smc_clc_eid_table.list, list) {
900 			memcpy(v2_ext->user_eids[i++], ueident->eid,
901 			       sizeof(ueident->eid));
902 		}
903 		read_unlock(&smc_clc_eid_table.lock);
904 	}
905 	if (smcd_indicated(ini->smc_type_v2)) {
906 		u8 *eid = NULL;
907 
908 		v2_ext->hdr.flag.seid = smc_clc_eid_table.seid_enabled;
909 		v2_ext->hdr.ism_gid_cnt = ini->ism_offered_cnt;
910 		v2_ext->hdr.smcd_v2_ext_offset = htons(sizeof(*v2_ext) -
911 				offsetofend(struct smc_clnt_opts_area_hdr,
912 					    smcd_v2_ext_offset) +
913 				v2_ext->hdr.eid_cnt * SMC_MAX_EID_LEN);
914 		smc_ism_get_system_eid(&eid);
915 		if (eid && v2_ext->hdr.flag.seid)
916 			memcpy(smcd_v2_ext->system_eid, eid, SMC_MAX_EID_LEN);
917 		plen += sizeof(*smcd_v2_ext);
918 		if (ini->ism_offered_cnt) {
919 			for (i = 1; i <= ini->ism_offered_cnt; i++) {
920 				smcd = ini->ism_dev[i];
921 				gidchids[i - 1].gid =
922 					htonll(smcd->ops->get_local_gid(smcd));
923 				gidchids[i - 1].chid =
924 					htons(smc_ism_get_chid(ini->ism_dev[i]));
925 			}
926 			plen += ini->ism_offered_cnt *
927 				sizeof(struct smc_clc_smcd_gid_chid);
928 		}
929 	}
930 	if (smcr_indicated(ini->smc_type_v2))
931 		memcpy(v2_ext->roce, ini->smcrv2.ib_gid_v2, SMC_GID_SIZE);
932 
933 	pclc_base->hdr.length = htons(plen);
934 	memcpy(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
935 
936 	/* send SMC Proposal CLC message */
937 	memset(&msg, 0, sizeof(msg));
938 	i = 0;
939 	vec[i].iov_base = pclc_base;
940 	vec[i++].iov_len = sizeof(*pclc_base);
941 	vec[i].iov_base = pclc_smcd;
942 	vec[i++].iov_len = sizeof(*pclc_smcd);
943 	if (ini->smc_type_v1 != SMC_TYPE_N) {
944 		vec[i].iov_base = pclc_prfx;
945 		vec[i++].iov_len = sizeof(*pclc_prfx);
946 		if (pclc_prfx->ipv6_prefixes_cnt > 0) {
947 			vec[i].iov_base = ipv6_prfx;
948 			vec[i++].iov_len = pclc_prfx->ipv6_prefixes_cnt *
949 					   sizeof(ipv6_prfx[0]);
950 		}
951 	}
952 	if (ini->smc_type_v2 != SMC_TYPE_N) {
953 		vec[i].iov_base = v2_ext;
954 		vec[i++].iov_len = sizeof(*v2_ext) +
955 				   (v2_ext->hdr.eid_cnt * SMC_MAX_EID_LEN);
956 		if (smcd_indicated(ini->smc_type_v2)) {
957 			vec[i].iov_base = smcd_v2_ext;
958 			vec[i++].iov_len = sizeof(*smcd_v2_ext);
959 			if (ini->ism_offered_cnt) {
960 				vec[i].iov_base = gidchids;
961 				vec[i++].iov_len = ini->ism_offered_cnt *
962 					sizeof(struct smc_clc_smcd_gid_chid);
963 			}
964 		}
965 	}
966 	vec[i].iov_base = trl;
967 	vec[i++].iov_len = sizeof(*trl);
968 	/* due to the few bytes needed for clc-handshake this cannot block */
969 	len = kernel_sendmsg(smc->clcsock, &msg, vec, i, plen);
970 	if (len < 0) {
971 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
972 		reason_code = -smc->sk.sk_err;
973 	} else if (len < ntohs(pclc_base->hdr.length)) {
974 		reason_code = -ENETUNREACH;
975 		smc->sk.sk_err = -reason_code;
976 	}
977 
978 	kfree(pclc);
979 	return reason_code;
980 }
981 
982 /* build and send CLC CONFIRM / ACCEPT message */
983 static int smc_clc_send_confirm_accept(struct smc_sock *smc,
984 				       struct smc_clc_msg_accept_confirm_v2 *clc_v2,
985 				       int first_contact, u8 version,
986 				       u8 *eid, struct smc_init_info *ini)
987 {
988 	struct smc_connection *conn = &smc->conn;
989 	struct smc_clc_msg_accept_confirm *clc;
990 	struct smc_clc_first_contact_ext fce;
991 	struct smc_clc_fce_gid_ext gle;
992 	struct smc_clc_msg_trail trl;
993 	struct kvec vec[5];
994 	struct msghdr msg;
995 	int i, len;
996 
997 	/* send SMC Confirm CLC msg */
998 	clc = (struct smc_clc_msg_accept_confirm *)clc_v2;
999 	clc->hdr.version = version;	/* SMC version */
1000 	if (first_contact)
1001 		clc->hdr.typev2 |= SMC_FIRST_CONTACT_MASK;
1002 	if (conn->lgr->is_smcd) {
1003 		/* SMC-D specific settings */
1004 		memcpy(clc->hdr.eyecatcher, SMCD_EYECATCHER,
1005 		       sizeof(SMCD_EYECATCHER));
1006 		clc->hdr.typev1 = SMC_TYPE_D;
1007 		clc->d0.gid =
1008 			conn->lgr->smcd->ops->get_local_gid(conn->lgr->smcd);
1009 		clc->d0.token = conn->rmb_desc->token;
1010 		clc->d0.dmbe_size = conn->rmbe_size_short;
1011 		clc->d0.dmbe_idx = 0;
1012 		memcpy(&clc->d0.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
1013 		if (version == SMC_V1) {
1014 			clc->hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
1015 		} else {
1016 			clc_v2->d1.chid =
1017 				htons(smc_ism_get_chid(conn->lgr->smcd));
1018 			if (eid && eid[0])
1019 				memcpy(clc_v2->d1.eid, eid, SMC_MAX_EID_LEN);
1020 			len = SMCD_CLC_ACCEPT_CONFIRM_LEN_V2;
1021 			if (first_contact)
1022 				smc_clc_fill_fce(&fce, &len);
1023 			clc_v2->hdr.length = htons(len);
1024 		}
1025 		memcpy(trl.eyecatcher, SMCD_EYECATCHER,
1026 		       sizeof(SMCD_EYECATCHER));
1027 	} else {
1028 		struct smc_link *link = conn->lnk;
1029 
1030 		/* SMC-R specific settings */
1031 		memcpy(clc->hdr.eyecatcher, SMC_EYECATCHER,
1032 		       sizeof(SMC_EYECATCHER));
1033 		clc->hdr.typev1 = SMC_TYPE_R;
1034 		clc->hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
1035 		memcpy(clc->r0.lcl.id_for_peer, local_systemid,
1036 		       sizeof(local_systemid));
1037 		memcpy(&clc->r0.lcl.gid, link->gid, SMC_GID_SIZE);
1038 		memcpy(&clc->r0.lcl.mac, &link->smcibdev->mac[link->ibport - 1],
1039 		       ETH_ALEN);
1040 		hton24(clc->r0.qpn, link->roce_qp->qp_num);
1041 		clc->r0.rmb_rkey =
1042 			htonl(conn->rmb_desc->mr[link->link_idx]->rkey);
1043 		clc->r0.rmbe_idx = 1; /* for now: 1 RMB = 1 RMBE */
1044 		clc->r0.rmbe_alert_token = htonl(conn->alert_token_local);
1045 		switch (clc->hdr.type) {
1046 		case SMC_CLC_ACCEPT:
1047 			clc->r0.qp_mtu = link->path_mtu;
1048 			break;
1049 		case SMC_CLC_CONFIRM:
1050 			clc->r0.qp_mtu = min(link->path_mtu, link->peer_mtu);
1051 			break;
1052 		}
1053 		clc->r0.rmbe_size = conn->rmbe_size_short;
1054 		clc->r0.rmb_dma_addr = conn->rmb_desc->is_vm ?
1055 			cpu_to_be64((uintptr_t)conn->rmb_desc->cpu_addr) :
1056 			cpu_to_be64((u64)sg_dma_address
1057 				    (conn->rmb_desc->sgt[link->link_idx].sgl));
1058 		hton24(clc->r0.psn, link->psn_initial);
1059 		if (version == SMC_V1) {
1060 			clc->hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
1061 		} else {
1062 			if (eid && eid[0])
1063 				memcpy(clc_v2->r1.eid, eid, SMC_MAX_EID_LEN);
1064 			len = SMCR_CLC_ACCEPT_CONFIRM_LEN_V2;
1065 			if (first_contact) {
1066 				smc_clc_fill_fce(&fce, &len);
1067 				fce.v2_direct = !link->lgr->uses_gateway;
1068 				memset(&gle, 0, sizeof(gle));
1069 				if (ini && clc->hdr.type == SMC_CLC_CONFIRM) {
1070 					gle.gid_cnt = ini->smcrv2.gidlist.len;
1071 					len += sizeof(gle);
1072 					len += gle.gid_cnt * sizeof(gle.gid[0]);
1073 				} else {
1074 					len += sizeof(gle.reserved);
1075 				}
1076 			}
1077 			clc_v2->hdr.length = htons(len);
1078 		}
1079 		memcpy(trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
1080 	}
1081 
1082 	memset(&msg, 0, sizeof(msg));
1083 	i = 0;
1084 	vec[i].iov_base = clc_v2;
1085 	if (version > SMC_V1)
1086 		vec[i++].iov_len = (clc->hdr.typev1 == SMC_TYPE_D ?
1087 					SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 :
1088 					SMCR_CLC_ACCEPT_CONFIRM_LEN_V2) -
1089 				   sizeof(trl);
1090 	else
1091 		vec[i++].iov_len = (clc->hdr.typev1 == SMC_TYPE_D ?
1092 						SMCD_CLC_ACCEPT_CONFIRM_LEN :
1093 						SMCR_CLC_ACCEPT_CONFIRM_LEN) -
1094 				   sizeof(trl);
1095 	if (version > SMC_V1 && first_contact) {
1096 		vec[i].iov_base = &fce;
1097 		vec[i++].iov_len = sizeof(fce);
1098 		if (!conn->lgr->is_smcd) {
1099 			if (clc->hdr.type == SMC_CLC_CONFIRM) {
1100 				vec[i].iov_base = &gle;
1101 				vec[i++].iov_len = sizeof(gle);
1102 				vec[i].iov_base = &ini->smcrv2.gidlist.list;
1103 				vec[i++].iov_len = gle.gid_cnt *
1104 						   sizeof(gle.gid[0]);
1105 			} else {
1106 				vec[i].iov_base = &gle.reserved;
1107 				vec[i++].iov_len = sizeof(gle.reserved);
1108 			}
1109 		}
1110 	}
1111 	vec[i].iov_base = &trl;
1112 	vec[i++].iov_len = sizeof(trl);
1113 	return kernel_sendmsg(smc->clcsock, &msg, vec, 1,
1114 			      ntohs(clc->hdr.length));
1115 }
1116 
1117 /* send CLC CONFIRM message across internal TCP socket */
1118 int smc_clc_send_confirm(struct smc_sock *smc, bool clnt_first_contact,
1119 			 u8 version, u8 *eid, struct smc_init_info *ini)
1120 {
1121 	struct smc_clc_msg_accept_confirm_v2 cclc_v2;
1122 	int reason_code = 0;
1123 	int len;
1124 
1125 	/* send SMC Confirm CLC msg */
1126 	memset(&cclc_v2, 0, sizeof(cclc_v2));
1127 	cclc_v2.hdr.type = SMC_CLC_CONFIRM;
1128 	len = smc_clc_send_confirm_accept(smc, &cclc_v2, clnt_first_contact,
1129 					  version, eid, ini);
1130 	if (len < ntohs(cclc_v2.hdr.length)) {
1131 		if (len >= 0) {
1132 			reason_code = -ENETUNREACH;
1133 			smc->sk.sk_err = -reason_code;
1134 		} else {
1135 			smc->sk.sk_err = smc->clcsock->sk->sk_err;
1136 			reason_code = -smc->sk.sk_err;
1137 		}
1138 	}
1139 	return reason_code;
1140 }
1141 
1142 /* send CLC ACCEPT message across internal TCP socket */
1143 int smc_clc_send_accept(struct smc_sock *new_smc, bool srv_first_contact,
1144 			u8 version, u8 *negotiated_eid)
1145 {
1146 	struct smc_clc_msg_accept_confirm_v2 aclc_v2;
1147 	int len;
1148 
1149 	memset(&aclc_v2, 0, sizeof(aclc_v2));
1150 	aclc_v2.hdr.type = SMC_CLC_ACCEPT;
1151 	len = smc_clc_send_confirm_accept(new_smc, &aclc_v2, srv_first_contact,
1152 					  version, negotiated_eid, NULL);
1153 	if (len < ntohs(aclc_v2.hdr.length))
1154 		len = len >= 0 ? -EPROTO : -new_smc->clcsock->sk->sk_err;
1155 
1156 	return len > 0 ? 0 : len;
1157 }
1158 
1159 void smc_clc_get_hostname(u8 **host)
1160 {
1161 	*host = &smc_hostname[0];
1162 }
1163 
1164 void __init smc_clc_init(void)
1165 {
1166 	struct new_utsname *u;
1167 
1168 	memset(smc_hostname, _S, sizeof(smc_hostname)); /* ASCII blanks */
1169 	u = utsname();
1170 	memcpy(smc_hostname, u->nodename,
1171 	       min_t(size_t, strlen(u->nodename), sizeof(smc_hostname)));
1172 
1173 	INIT_LIST_HEAD(&smc_clc_eid_table.list);
1174 	rwlock_init(&smc_clc_eid_table.lock);
1175 	smc_clc_eid_table.ueid_cnt = 0;
1176 	smc_clc_eid_table.seid_enabled = 1;
1177 }
1178 
1179 void smc_clc_exit(void)
1180 {
1181 	smc_clc_ueid_remove(NULL);
1182 }
1183