xref: /linux/net/smc/smc_clc.c (revision 55d0969c451159cff86949b38c39171cab962069)
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 IS_ENABLED(CONFIG_S390)
159 	if (!rc && !smc_clc_eid_table.ueid_cnt) {
160 		smc_clc_eid_table.seid_enabled = 1;
161 		rc = -EAGAIN;	/* indicate success and enabling of seid */
162 	}
163 #endif
164 	write_unlock(&smc_clc_eid_table.lock);
165 	return rc;
166 }
167 
168 int smc_nl_remove_ueid(struct sk_buff *skb, struct genl_info *info)
169 {
170 	struct nlattr *nla_ueid = info->attrs[SMC_NLA_EID_TABLE_ENTRY];
171 	char *ueid;
172 
173 	if (!nla_ueid || nla_len(nla_ueid) != SMC_MAX_EID_LEN + 1)
174 		return -EINVAL;
175 	ueid = (char *)nla_data(nla_ueid);
176 
177 	return smc_clc_ueid_remove(ueid);
178 }
179 
180 int smc_nl_flush_ueid(struct sk_buff *skb, struct genl_info *info)
181 {
182 	smc_clc_ueid_remove(NULL);
183 	return 0;
184 }
185 
186 static int smc_nl_ueid_dumpinfo(struct sk_buff *skb, u32 portid, u32 seq,
187 				u32 flags, char *ueid)
188 {
189 	char ueid_str[SMC_MAX_EID_LEN + 1];
190 	void *hdr;
191 
192 	hdr = genlmsg_put(skb, portid, seq, &smc_gen_nl_family,
193 			  flags, SMC_NETLINK_DUMP_UEID);
194 	if (!hdr)
195 		return -ENOMEM;
196 	memcpy(ueid_str, ueid, SMC_MAX_EID_LEN);
197 	ueid_str[SMC_MAX_EID_LEN] = 0;
198 	if (nla_put_string(skb, SMC_NLA_EID_TABLE_ENTRY, ueid_str)) {
199 		genlmsg_cancel(skb, hdr);
200 		return -EMSGSIZE;
201 	}
202 	genlmsg_end(skb, hdr);
203 	return 0;
204 }
205 
206 static int _smc_nl_ueid_dump(struct sk_buff *skb, u32 portid, u32 seq,
207 			     int start_idx)
208 {
209 	struct smc_clc_eid_entry *lst_ueid;
210 	int idx = 0;
211 
212 	read_lock(&smc_clc_eid_table.lock);
213 	list_for_each_entry(lst_ueid, &smc_clc_eid_table.list, list) {
214 		if (idx++ < start_idx)
215 			continue;
216 		if (smc_nl_ueid_dumpinfo(skb, portid, seq, NLM_F_MULTI,
217 					 lst_ueid->eid)) {
218 			--idx;
219 			break;
220 		}
221 	}
222 	read_unlock(&smc_clc_eid_table.lock);
223 	return idx;
224 }
225 
226 int smc_nl_dump_ueid(struct sk_buff *skb, struct netlink_callback *cb)
227 {
228 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
229 	int idx;
230 
231 	idx = _smc_nl_ueid_dump(skb, NETLINK_CB(cb->skb).portid,
232 				cb->nlh->nlmsg_seq, cb_ctx->pos[0]);
233 
234 	cb_ctx->pos[0] = idx;
235 	return skb->len;
236 }
237 
238 int smc_nl_dump_seid(struct sk_buff *skb, struct netlink_callback *cb)
239 {
240 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
241 	char seid_str[SMC_MAX_EID_LEN + 1];
242 	u8 seid_enabled;
243 	void *hdr;
244 	u8 *seid;
245 
246 	if (cb_ctx->pos[0])
247 		return skb->len;
248 
249 	hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
250 			  &smc_gen_nl_family, NLM_F_MULTI,
251 			  SMC_NETLINK_DUMP_SEID);
252 	if (!hdr)
253 		return -ENOMEM;
254 	if (!smc_ism_is_v2_capable())
255 		goto end;
256 
257 	smc_ism_get_system_eid(&seid);
258 	memcpy(seid_str, seid, SMC_MAX_EID_LEN);
259 	seid_str[SMC_MAX_EID_LEN] = 0;
260 	if (nla_put_string(skb, SMC_NLA_SEID_ENTRY, seid_str))
261 		goto err;
262 	read_lock(&smc_clc_eid_table.lock);
263 	seid_enabled = smc_clc_eid_table.seid_enabled;
264 	read_unlock(&smc_clc_eid_table.lock);
265 	if (nla_put_u8(skb, SMC_NLA_SEID_ENABLED, seid_enabled))
266 		goto err;
267 end:
268 	genlmsg_end(skb, hdr);
269 	cb_ctx->pos[0]++;
270 	return skb->len;
271 err:
272 	genlmsg_cancel(skb, hdr);
273 	return -EMSGSIZE;
274 }
275 
276 int smc_nl_enable_seid(struct sk_buff *skb, struct genl_info *info)
277 {
278 #if IS_ENABLED(CONFIG_S390)
279 	write_lock(&smc_clc_eid_table.lock);
280 	smc_clc_eid_table.seid_enabled = 1;
281 	write_unlock(&smc_clc_eid_table.lock);
282 	return 0;
283 #else
284 	return -EOPNOTSUPP;
285 #endif
286 }
287 
288 int smc_nl_disable_seid(struct sk_buff *skb, struct genl_info *info)
289 {
290 	int rc = 0;
291 
292 #if IS_ENABLED(CONFIG_S390)
293 	write_lock(&smc_clc_eid_table.lock);
294 	if (!smc_clc_eid_table.ueid_cnt)
295 		rc = -ENOENT;
296 	else
297 		smc_clc_eid_table.seid_enabled = 0;
298 	write_unlock(&smc_clc_eid_table.lock);
299 #else
300 	rc = -EOPNOTSUPP;
301 #endif
302 	return rc;
303 }
304 
305 static bool _smc_clc_match_ueid(u8 *peer_ueid)
306 {
307 	struct smc_clc_eid_entry *tmp_ueid;
308 
309 	list_for_each_entry(tmp_ueid, &smc_clc_eid_table.list, list) {
310 		if (!memcmp(tmp_ueid->eid, peer_ueid, SMC_MAX_EID_LEN))
311 			return true;
312 	}
313 	return false;
314 }
315 
316 bool smc_clc_match_eid(u8 *negotiated_eid,
317 		       struct smc_clc_v2_extension *smc_v2_ext,
318 		       u8 *peer_eid, u8 *local_eid)
319 {
320 	bool match = false;
321 	int i;
322 
323 	negotiated_eid[0] = 0;
324 	read_lock(&smc_clc_eid_table.lock);
325 	if (peer_eid && local_eid &&
326 	    smc_clc_eid_table.seid_enabled &&
327 	    smc_v2_ext->hdr.flag.seid &&
328 	    !memcmp(peer_eid, local_eid, SMC_MAX_EID_LEN)) {
329 		memcpy(negotiated_eid, peer_eid, SMC_MAX_EID_LEN);
330 		match = true;
331 		goto out;
332 	}
333 
334 	for (i = 0; i < smc_v2_ext->hdr.eid_cnt; i++) {
335 		if (_smc_clc_match_ueid(smc_v2_ext->user_eids[i])) {
336 			memcpy(negotiated_eid, smc_v2_ext->user_eids[i],
337 			       SMC_MAX_EID_LEN);
338 			match = true;
339 			goto out;
340 		}
341 	}
342 out:
343 	read_unlock(&smc_clc_eid_table.lock);
344 	return match;
345 }
346 
347 /* check arriving CLC proposal */
348 static bool smc_clc_msg_prop_valid(struct smc_clc_msg_proposal *pclc)
349 {
350 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
351 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
352 	struct smc_clc_msg_hdr *hdr = &pclc->hdr;
353 	struct smc_clc_v2_extension *v2_ext;
354 
355 	v2_ext = smc_get_clc_v2_ext(pclc);
356 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
357 	if (hdr->version == SMC_V1) {
358 		if (hdr->typev1 == SMC_TYPE_N)
359 			return false;
360 		if (ntohs(hdr->length) !=
361 			sizeof(*pclc) + ntohs(pclc->iparea_offset) +
362 			sizeof(*pclc_prfx) +
363 			pclc_prfx->ipv6_prefixes_cnt *
364 				sizeof(struct smc_clc_ipv6_prefix) +
365 			sizeof(struct smc_clc_msg_trail))
366 			return false;
367 	} else {
368 		if (ntohs(hdr->length) !=
369 			sizeof(*pclc) +
370 			sizeof(struct smc_clc_msg_smcd) +
371 			(hdr->typev1 != SMC_TYPE_N ?
372 				sizeof(*pclc_prfx) +
373 				pclc_prfx->ipv6_prefixes_cnt *
374 				sizeof(struct smc_clc_ipv6_prefix) : 0) +
375 			(hdr->typev2 != SMC_TYPE_N ?
376 				sizeof(*v2_ext) +
377 				v2_ext->hdr.eid_cnt * SMC_MAX_EID_LEN : 0) +
378 			(smcd_indicated(hdr->typev2) ?
379 				sizeof(*smcd_v2_ext) + v2_ext->hdr.ism_gid_cnt *
380 					sizeof(struct smc_clc_smcd_gid_chid) :
381 				0) +
382 			sizeof(struct smc_clc_msg_trail))
383 			return false;
384 	}
385 	return true;
386 }
387 
388 /* check arriving CLC accept or confirm */
389 static bool
390 smc_clc_msg_acc_conf_valid(struct smc_clc_msg_accept_confirm *clc)
391 {
392 	struct smc_clc_msg_hdr *hdr = &clc->hdr;
393 
394 	if (hdr->typev1 != SMC_TYPE_R && hdr->typev1 != SMC_TYPE_D)
395 		return false;
396 	if (hdr->version == SMC_V1) {
397 		if ((hdr->typev1 == SMC_TYPE_R &&
398 		     ntohs(hdr->length) != SMCR_CLC_ACCEPT_CONFIRM_LEN) ||
399 		    (hdr->typev1 == SMC_TYPE_D &&
400 		     ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN))
401 			return false;
402 	} else {
403 		if (hdr->typev1 == SMC_TYPE_D &&
404 		    ntohs(hdr->length) < SMCD_CLC_ACCEPT_CONFIRM_LEN_V2)
405 			return false;
406 		if (hdr->typev1 == SMC_TYPE_R &&
407 		    ntohs(hdr->length) < SMCR_CLC_ACCEPT_CONFIRM_LEN_V2)
408 			return false;
409 	}
410 	return true;
411 }
412 
413 /* check arriving CLC decline */
414 static bool
415 smc_clc_msg_decl_valid(struct smc_clc_msg_decline *dclc)
416 {
417 	struct smc_clc_msg_hdr *hdr = &dclc->hdr;
418 
419 	if (hdr->typev1 != SMC_TYPE_R && hdr->typev1 != SMC_TYPE_D)
420 		return false;
421 	if (hdr->version == SMC_V1) {
422 		if (ntohs(hdr->length) != sizeof(struct smc_clc_msg_decline))
423 			return false;
424 	} else {
425 		if (ntohs(hdr->length) != sizeof(struct smc_clc_msg_decline_v2))
426 			return false;
427 	}
428 	return true;
429 }
430 
431 static int smc_clc_fill_fce_v2x(struct smc_clc_first_contact_ext_v2x *fce_v2x,
432 				struct smc_init_info *ini)
433 {
434 	int ret = sizeof(*fce_v2x);
435 
436 	memset(fce_v2x, 0, sizeof(*fce_v2x));
437 	fce_v2x->fce_v2_base.os_type = SMC_CLC_OS_LINUX;
438 	fce_v2x->fce_v2_base.release = ini->release_nr;
439 	memcpy(fce_v2x->fce_v2_base.hostname,
440 	       smc_hostname, sizeof(smc_hostname));
441 	if (ini->is_smcd && ini->release_nr < SMC_RELEASE_1) {
442 		ret = sizeof(struct smc_clc_first_contact_ext);
443 		goto out;
444 	}
445 
446 	if (ini->release_nr >= SMC_RELEASE_1) {
447 		if (!ini->is_smcd) {
448 			fce_v2x->max_conns = ini->max_conns;
449 			fce_v2x->max_links = ini->max_links;
450 		}
451 		fce_v2x->feature_mask = htons(ini->feature_mask);
452 	}
453 
454 out:
455 	return ret;
456 }
457 
458 /* check if received message has a correct header length and contains valid
459  * heading and trailing eyecatchers
460  */
461 static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm, bool check_trl)
462 {
463 	struct smc_clc_msg_accept_confirm *clc;
464 	struct smc_clc_msg_proposal *pclc;
465 	struct smc_clc_msg_decline *dclc;
466 	struct smc_clc_msg_trail *trl;
467 
468 	if (memcmp(clcm->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
469 	    memcmp(clcm->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
470 		return false;
471 	switch (clcm->type) {
472 	case SMC_CLC_PROPOSAL:
473 		pclc = (struct smc_clc_msg_proposal *)clcm;
474 		if (!smc_clc_msg_prop_valid(pclc))
475 			return false;
476 		trl = (struct smc_clc_msg_trail *)
477 			((u8 *)pclc + ntohs(pclc->hdr.length) - sizeof(*trl));
478 		break;
479 	case SMC_CLC_ACCEPT:
480 	case SMC_CLC_CONFIRM:
481 		clc = (struct smc_clc_msg_accept_confirm *)clcm;
482 		if (!smc_clc_msg_acc_conf_valid(clc))
483 			return false;
484 		trl = (struct smc_clc_msg_trail *)
485 			((u8 *)clc + ntohs(clc->hdr.length) - sizeof(*trl));
486 		break;
487 	case SMC_CLC_DECLINE:
488 		dclc = (struct smc_clc_msg_decline *)clcm;
489 		if (!smc_clc_msg_decl_valid(dclc))
490 			return false;
491 		check_trl = false;
492 		break;
493 	default:
494 		return false;
495 	}
496 	if (check_trl &&
497 	    memcmp(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
498 	    memcmp(trl->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
499 		return false;
500 	return true;
501 }
502 
503 /* find ipv4 addr on device and get the prefix len, fill CLC proposal msg */
504 static int smc_clc_prfx_set4_rcu(struct dst_entry *dst, __be32 ipv4,
505 				 struct smc_clc_msg_proposal_prefix *prop)
506 {
507 	struct in_device *in_dev = __in_dev_get_rcu(dst->dev);
508 	const struct in_ifaddr *ifa;
509 
510 	if (!in_dev)
511 		return -ENODEV;
512 
513 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
514 		if (!inet_ifa_match(ipv4, ifa))
515 			continue;
516 		prop->prefix_len = inet_mask_len(ifa->ifa_mask);
517 		prop->outgoing_subnet = ifa->ifa_address & ifa->ifa_mask;
518 		/* prop->ipv6_prefixes_cnt = 0; already done by memset before */
519 		return 0;
520 	}
521 	return -ENOENT;
522 }
523 
524 /* fill CLC proposal msg with ipv6 prefixes from device */
525 static int smc_clc_prfx_set6_rcu(struct dst_entry *dst,
526 				 struct smc_clc_msg_proposal_prefix *prop,
527 				 struct smc_clc_ipv6_prefix *ipv6_prfx)
528 {
529 #if IS_ENABLED(CONFIG_IPV6)
530 	struct inet6_dev *in6_dev = __in6_dev_get(dst->dev);
531 	struct inet6_ifaddr *ifa;
532 	int cnt = 0;
533 
534 	if (!in6_dev)
535 		return -ENODEV;
536 	/* use a maximum of 8 IPv6 prefixes from device */
537 	list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
538 		if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
539 			continue;
540 		ipv6_addr_prefix(&ipv6_prfx[cnt].prefix,
541 				 &ifa->addr, ifa->prefix_len);
542 		ipv6_prfx[cnt].prefix_len = ifa->prefix_len;
543 		cnt++;
544 		if (cnt == SMC_CLC_MAX_V6_PREFIX)
545 			break;
546 	}
547 	prop->ipv6_prefixes_cnt = cnt;
548 	if (cnt)
549 		return 0;
550 #endif
551 	return -ENOENT;
552 }
553 
554 /* retrieve and set prefixes in CLC proposal msg */
555 static int smc_clc_prfx_set(struct socket *clcsock,
556 			    struct smc_clc_msg_proposal_prefix *prop,
557 			    struct smc_clc_ipv6_prefix *ipv6_prfx)
558 {
559 	struct dst_entry *dst = sk_dst_get(clcsock->sk);
560 	struct sockaddr_storage addrs;
561 	struct sockaddr_in6 *addr6;
562 	struct sockaddr_in *addr;
563 	int rc = -ENOENT;
564 
565 	if (!dst) {
566 		rc = -ENOTCONN;
567 		goto out;
568 	}
569 	if (!dst->dev) {
570 		rc = -ENODEV;
571 		goto out_rel;
572 	}
573 	/* get address to which the internal TCP socket is bound */
574 	if (kernel_getsockname(clcsock, (struct sockaddr *)&addrs) < 0)
575 		goto out_rel;
576 	/* analyze IP specific data of net_device belonging to TCP socket */
577 	addr6 = (struct sockaddr_in6 *)&addrs;
578 	rcu_read_lock();
579 	if (addrs.ss_family == PF_INET) {
580 		/* IPv4 */
581 		addr = (struct sockaddr_in *)&addrs;
582 		rc = smc_clc_prfx_set4_rcu(dst, addr->sin_addr.s_addr, prop);
583 	} else if (ipv6_addr_v4mapped(&addr6->sin6_addr)) {
584 		/* mapped IPv4 address - peer is IPv4 only */
585 		rc = smc_clc_prfx_set4_rcu(dst, addr6->sin6_addr.s6_addr32[3],
586 					   prop);
587 	} else {
588 		/* IPv6 */
589 		rc = smc_clc_prfx_set6_rcu(dst, prop, ipv6_prfx);
590 	}
591 	rcu_read_unlock();
592 out_rel:
593 	dst_release(dst);
594 out:
595 	return rc;
596 }
597 
598 /* match ipv4 addrs of dev against addr in CLC proposal */
599 static int smc_clc_prfx_match4_rcu(struct net_device *dev,
600 				   struct smc_clc_msg_proposal_prefix *prop)
601 {
602 	struct in_device *in_dev = __in_dev_get_rcu(dev);
603 	const struct in_ifaddr *ifa;
604 
605 	if (!in_dev)
606 		return -ENODEV;
607 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
608 		if (prop->prefix_len == inet_mask_len(ifa->ifa_mask) &&
609 		    inet_ifa_match(prop->outgoing_subnet, ifa))
610 			return 0;
611 	}
612 
613 	return -ENOENT;
614 }
615 
616 /* match ipv6 addrs of dev against addrs in CLC proposal */
617 static int smc_clc_prfx_match6_rcu(struct net_device *dev,
618 				   struct smc_clc_msg_proposal_prefix *prop)
619 {
620 #if IS_ENABLED(CONFIG_IPV6)
621 	struct inet6_dev *in6_dev = __in6_dev_get(dev);
622 	struct smc_clc_ipv6_prefix *ipv6_prfx;
623 	struct inet6_ifaddr *ifa;
624 	int i, max;
625 
626 	if (!in6_dev)
627 		return -ENODEV;
628 	/* ipv6 prefix list starts behind smc_clc_msg_proposal_prefix */
629 	ipv6_prfx = (struct smc_clc_ipv6_prefix *)((u8 *)prop + sizeof(*prop));
630 	max = min_t(u8, prop->ipv6_prefixes_cnt, SMC_CLC_MAX_V6_PREFIX);
631 	list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
632 		if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
633 			continue;
634 		for (i = 0; i < max; i++) {
635 			if (ifa->prefix_len == ipv6_prfx[i].prefix_len &&
636 			    ipv6_prefix_equal(&ifa->addr, &ipv6_prfx[i].prefix,
637 					      ifa->prefix_len))
638 				return 0;
639 		}
640 	}
641 #endif
642 	return -ENOENT;
643 }
644 
645 /* check if proposed prefixes match one of our device prefixes */
646 int smc_clc_prfx_match(struct socket *clcsock,
647 		       struct smc_clc_msg_proposal_prefix *prop)
648 {
649 	struct dst_entry *dst = sk_dst_get(clcsock->sk);
650 	int rc;
651 
652 	if (!dst) {
653 		rc = -ENOTCONN;
654 		goto out;
655 	}
656 	if (!dst->dev) {
657 		rc = -ENODEV;
658 		goto out_rel;
659 	}
660 	rcu_read_lock();
661 	if (!prop->ipv6_prefixes_cnt)
662 		rc = smc_clc_prfx_match4_rcu(dst->dev, prop);
663 	else
664 		rc = smc_clc_prfx_match6_rcu(dst->dev, prop);
665 	rcu_read_unlock();
666 out_rel:
667 	dst_release(dst);
668 out:
669 	return rc;
670 }
671 
672 /* Wait for data on the tcp-socket, analyze received data
673  * Returns:
674  * 0 if success and it was not a decline that we received.
675  * SMC_CLC_DECL_REPLY if decline received for fallback w/o another decl send.
676  * clcsock error, -EINTR, -ECONNRESET, -EPROTO otherwise.
677  */
678 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
679 		     u8 expected_type, unsigned long timeout)
680 {
681 	long rcvtimeo = smc->clcsock->sk->sk_rcvtimeo;
682 	struct sock *clc_sk = smc->clcsock->sk;
683 	struct smc_clc_msg_hdr *clcm = buf;
684 	struct msghdr msg = {NULL, 0};
685 	int reason_code = 0;
686 	struct kvec vec = {buf, buflen};
687 	int len, datlen, recvlen;
688 	bool check_trl = true;
689 	int krflags;
690 
691 	/* peek the first few bytes to determine length of data to receive
692 	 * so we don't consume any subsequent CLC message or payload data
693 	 * in the TCP byte stream
694 	 */
695 	/*
696 	 * Caller must make sure that buflen is no less than
697 	 * sizeof(struct smc_clc_msg_hdr)
698 	 */
699 	krflags = MSG_PEEK | MSG_WAITALL;
700 	clc_sk->sk_rcvtimeo = timeout;
701 	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &vec, 1,
702 			sizeof(struct smc_clc_msg_hdr));
703 	len = sock_recvmsg(smc->clcsock, &msg, krflags);
704 	if (signal_pending(current)) {
705 		reason_code = -EINTR;
706 		clc_sk->sk_err = EINTR;
707 		smc->sk.sk_err = EINTR;
708 		goto out;
709 	}
710 	if (clc_sk->sk_err) {
711 		reason_code = -clc_sk->sk_err;
712 		if (clc_sk->sk_err == EAGAIN &&
713 		    expected_type == SMC_CLC_DECLINE)
714 			clc_sk->sk_err = 0; /* reset for fallback usage */
715 		else
716 			smc->sk.sk_err = clc_sk->sk_err;
717 		goto out;
718 	}
719 	if (!len) { /* peer has performed orderly shutdown */
720 		smc->sk.sk_err = ECONNRESET;
721 		reason_code = -ECONNRESET;
722 		goto out;
723 	}
724 	if (len < 0) {
725 		if (len != -EAGAIN || expected_type != SMC_CLC_DECLINE)
726 			smc->sk.sk_err = -len;
727 		reason_code = len;
728 		goto out;
729 	}
730 	datlen = ntohs(clcm->length);
731 	if ((len < sizeof(struct smc_clc_msg_hdr)) ||
732 	    (clcm->version < SMC_V1) ||
733 	    ((clcm->type != SMC_CLC_DECLINE) &&
734 	     (clcm->type != expected_type))) {
735 		smc->sk.sk_err = EPROTO;
736 		reason_code = -EPROTO;
737 		goto out;
738 	}
739 
740 	/* receive the complete CLC message */
741 	memset(&msg, 0, sizeof(struct msghdr));
742 	if (datlen > buflen) {
743 		check_trl = false;
744 		recvlen = buflen;
745 	} else {
746 		recvlen = datlen;
747 	}
748 	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &vec, 1, recvlen);
749 	krflags = MSG_WAITALL;
750 	len = sock_recvmsg(smc->clcsock, &msg, krflags);
751 	if (len < recvlen || !smc_clc_msg_hdr_valid(clcm, check_trl)) {
752 		smc->sk.sk_err = EPROTO;
753 		reason_code = -EPROTO;
754 		goto out;
755 	}
756 	datlen -= len;
757 	while (datlen) {
758 		u8 tmp[SMC_CLC_RECV_BUF_LEN];
759 
760 		vec.iov_base = &tmp;
761 		vec.iov_len = SMC_CLC_RECV_BUF_LEN;
762 		/* receive remaining proposal message */
763 		recvlen = datlen > SMC_CLC_RECV_BUF_LEN ?
764 						SMC_CLC_RECV_BUF_LEN : datlen;
765 		iov_iter_kvec(&msg.msg_iter, ITER_DEST, &vec, 1, recvlen);
766 		len = sock_recvmsg(smc->clcsock, &msg, krflags);
767 		datlen -= len;
768 	}
769 	if (clcm->type == SMC_CLC_DECLINE) {
770 		struct smc_clc_msg_decline *dclc;
771 
772 		dclc = (struct smc_clc_msg_decline *)clcm;
773 		reason_code = SMC_CLC_DECL_PEERDECL;
774 		smc->peer_diagnosis = ntohl(dclc->peer_diagnosis);
775 		if (((struct smc_clc_msg_decline *)buf)->hdr.typev2 &
776 						SMC_FIRST_CONTACT_MASK) {
777 			smc->conn.lgr->sync_err = 1;
778 			smc_lgr_terminate_sched(smc->conn.lgr);
779 		}
780 	}
781 
782 out:
783 	clc_sk->sk_rcvtimeo = rcvtimeo;
784 	return reason_code;
785 }
786 
787 /* send CLC DECLINE message across internal TCP socket */
788 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info, u8 version)
789 {
790 	struct smc_clc_msg_decline *dclc_v1;
791 	struct smc_clc_msg_decline_v2 dclc;
792 	struct msghdr msg;
793 	int len, send_len;
794 	struct kvec vec;
795 
796 	dclc_v1 = (struct smc_clc_msg_decline *)&dclc;
797 	memset(&dclc, 0, sizeof(dclc));
798 	memcpy(dclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
799 	dclc.hdr.type = SMC_CLC_DECLINE;
800 	dclc.hdr.version = version;
801 	dclc.os_type = version == SMC_V1 ? 0 : SMC_CLC_OS_LINUX;
802 	dclc.hdr.typev2 = (peer_diag_info == SMC_CLC_DECL_SYNCERR) ?
803 						SMC_FIRST_CONTACT_MASK : 0;
804 	if ((!smc_conn_lgr_valid(&smc->conn) || !smc->conn.lgr->is_smcd) &&
805 	    smc_ib_is_valid_local_systemid())
806 		memcpy(dclc.id_for_peer, local_systemid,
807 		       sizeof(local_systemid));
808 	dclc.peer_diagnosis = htonl(peer_diag_info);
809 	if (version == SMC_V1) {
810 		memcpy(dclc_v1->trl.eyecatcher, SMC_EYECATCHER,
811 		       sizeof(SMC_EYECATCHER));
812 		send_len = sizeof(*dclc_v1);
813 	} else {
814 		memcpy(dclc.trl.eyecatcher, SMC_EYECATCHER,
815 		       sizeof(SMC_EYECATCHER));
816 		send_len = sizeof(dclc);
817 	}
818 	dclc.hdr.length = htons(send_len);
819 
820 	memset(&msg, 0, sizeof(msg));
821 	vec.iov_base = &dclc;
822 	vec.iov_len = send_len;
823 	len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1, send_len);
824 	if (len < 0 || len < send_len)
825 		len = -EPROTO;
826 	return len > 0 ? 0 : len;
827 }
828 
829 /* send CLC PROPOSAL message across internal TCP socket */
830 int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini)
831 {
832 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
833 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
834 	struct smc_clc_msg_proposal *pclc_base;
835 	struct smc_clc_smcd_gid_chid *gidchids;
836 	struct smc_clc_msg_proposal_area *pclc;
837 	struct smc_clc_ipv6_prefix *ipv6_prfx;
838 	struct net *net = sock_net(&smc->sk);
839 	struct smc_clc_v2_extension *v2_ext;
840 	struct smc_clc_msg_smcd *pclc_smcd;
841 	struct smc_clc_msg_trail *trl;
842 	struct smcd_dev *smcd;
843 	int len, i, plen, rc;
844 	int reason_code = 0;
845 	struct kvec vec[8];
846 	struct msghdr msg;
847 
848 	pclc = kzalloc(sizeof(*pclc), GFP_KERNEL);
849 	if (!pclc)
850 		return -ENOMEM;
851 
852 	pclc_base = &pclc->pclc_base;
853 	pclc_smcd = &pclc->pclc_smcd;
854 	pclc_prfx = &pclc->pclc_prfx;
855 	ipv6_prfx = pclc->pclc_prfx_ipv6;
856 	v2_ext = container_of(&pclc->pclc_v2_ext,
857 			      struct smc_clc_v2_extension, fixed);
858 	smcd_v2_ext = container_of(&pclc->pclc_smcd_v2_ext,
859 				   struct smc_clc_smcd_v2_extension, fixed);
860 	gidchids = pclc->pclc_gidchids;
861 	trl = &pclc->pclc_trl;
862 
863 	pclc_base->hdr.version = SMC_V2;
864 	pclc_base->hdr.typev1 = ini->smc_type_v1;
865 	pclc_base->hdr.typev2 = ini->smc_type_v2;
866 	plen = sizeof(*pclc_base) + sizeof(*pclc_smcd) + sizeof(*trl);
867 
868 	/* retrieve ip prefixes for CLC proposal msg */
869 	if (ini->smc_type_v1 != SMC_TYPE_N) {
870 		rc = smc_clc_prfx_set(smc->clcsock, pclc_prfx, ipv6_prfx);
871 		if (rc) {
872 			if (ini->smc_type_v2 == SMC_TYPE_N) {
873 				kfree(pclc);
874 				return SMC_CLC_DECL_CNFERR;
875 			}
876 			pclc_base->hdr.typev1 = SMC_TYPE_N;
877 		} else {
878 			pclc_base->iparea_offset = htons(sizeof(*pclc_smcd));
879 			plen += sizeof(*pclc_prfx) +
880 					pclc_prfx->ipv6_prefixes_cnt *
881 					sizeof(ipv6_prfx[0]);
882 		}
883 	}
884 
885 	/* build SMC Proposal CLC message */
886 	memcpy(pclc_base->hdr.eyecatcher, SMC_EYECATCHER,
887 	       sizeof(SMC_EYECATCHER));
888 	pclc_base->hdr.type = SMC_CLC_PROPOSAL;
889 	if (smcr_indicated(ini->smc_type_v1)) {
890 		/* add SMC-R specifics */
891 		memcpy(pclc_base->lcl.id_for_peer, local_systemid,
892 		       sizeof(local_systemid));
893 		memcpy(pclc_base->lcl.gid, ini->ib_gid, SMC_GID_SIZE);
894 		memcpy(pclc_base->lcl.mac, &ini->ib_dev->mac[ini->ib_port - 1],
895 		       ETH_ALEN);
896 	}
897 	if (smcd_indicated(ini->smc_type_v1)) {
898 		struct smcd_gid smcd_gid;
899 
900 		/* add SMC-D specifics */
901 		if (ini->ism_dev[0]) {
902 			smcd = ini->ism_dev[0];
903 			smcd->ops->get_local_gid(smcd, &smcd_gid);
904 			pclc_smcd->ism.gid = htonll(smcd_gid.gid);
905 			pclc_smcd->ism.chid =
906 				htons(smc_ism_get_chid(ini->ism_dev[0]));
907 		}
908 	}
909 	if (ini->smc_type_v2 == SMC_TYPE_N) {
910 		pclc_smcd->v2_ext_offset = 0;
911 	} else {
912 		struct smc_clc_eid_entry *ueident;
913 		u16 v2_ext_offset;
914 
915 		v2_ext->hdr.flag.release = SMC_RELEASE;
916 		v2_ext_offset = sizeof(*pclc_smcd) -
917 			offsetofend(struct smc_clc_msg_smcd, v2_ext_offset);
918 		if (ini->smc_type_v1 != SMC_TYPE_N)
919 			v2_ext_offset += sizeof(*pclc_prfx) +
920 						pclc_prfx->ipv6_prefixes_cnt *
921 						sizeof(ipv6_prfx[0]);
922 		pclc_smcd->v2_ext_offset = htons(v2_ext_offset);
923 		plen += sizeof(*v2_ext);
924 
925 		v2_ext->feature_mask = htons(SMC_FEATURE_MASK);
926 		read_lock(&smc_clc_eid_table.lock);
927 		v2_ext->hdr.eid_cnt = smc_clc_eid_table.ueid_cnt;
928 		plen += smc_clc_eid_table.ueid_cnt * SMC_MAX_EID_LEN;
929 		i = 0;
930 		list_for_each_entry(ueident, &smc_clc_eid_table.list, list) {
931 			memcpy(v2_ext->user_eids[i++], ueident->eid,
932 			       sizeof(ueident->eid));
933 		}
934 		read_unlock(&smc_clc_eid_table.lock);
935 	}
936 	if (smcd_indicated(ini->smc_type_v2)) {
937 		struct smcd_gid smcd_gid;
938 		u8 *eid = NULL;
939 		int entry = 0;
940 
941 		v2_ext->hdr.flag.seid = smc_clc_eid_table.seid_enabled;
942 		v2_ext->hdr.smcd_v2_ext_offset = htons(sizeof(*v2_ext) -
943 				offsetofend(struct smc_clnt_opts_area_hdr,
944 					    smcd_v2_ext_offset) +
945 				v2_ext->hdr.eid_cnt * SMC_MAX_EID_LEN);
946 		smc_ism_get_system_eid(&eid);
947 		if (eid && v2_ext->hdr.flag.seid)
948 			memcpy(smcd_v2_ext->system_eid, eid, SMC_MAX_EID_LEN);
949 		plen += sizeof(*smcd_v2_ext);
950 		if (ini->ism_offered_cnt) {
951 			for (i = 1; i <= ini->ism_offered_cnt; i++) {
952 				smcd = ini->ism_dev[i];
953 				smcd->ops->get_local_gid(smcd, &smcd_gid);
954 				gidchids[entry].chid =
955 					htons(smc_ism_get_chid(ini->ism_dev[i]));
956 				gidchids[entry].gid = htonll(smcd_gid.gid);
957 				if (smc_ism_is_emulated(smcd)) {
958 					/* an Emulated-ISM device takes two
959 					 * entries. CHID of the second entry
960 					 * repeats that of the first entry.
961 					 */
962 					gidchids[entry + 1].chid =
963 						gidchids[entry].chid;
964 					gidchids[entry + 1].gid =
965 						htonll(smcd_gid.gid_ext);
966 					entry++;
967 				}
968 				entry++;
969 			}
970 			plen += entry * sizeof(struct smc_clc_smcd_gid_chid);
971 		}
972 		v2_ext->hdr.ism_gid_cnt = entry;
973 	}
974 	if (smcr_indicated(ini->smc_type_v2)) {
975 		memcpy(v2_ext->roce, ini->smcrv2.ib_gid_v2, SMC_GID_SIZE);
976 		v2_ext->max_conns = net->smc.sysctl_max_conns_per_lgr;
977 		v2_ext->max_links = net->smc.sysctl_max_links_per_lgr;
978 	}
979 
980 	pclc_base->hdr.length = htons(plen);
981 	memcpy(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
982 
983 	/* send SMC Proposal CLC message */
984 	memset(&msg, 0, sizeof(msg));
985 	i = 0;
986 	vec[i].iov_base = pclc_base;
987 	vec[i++].iov_len = sizeof(*pclc_base);
988 	vec[i].iov_base = pclc_smcd;
989 	vec[i++].iov_len = sizeof(*pclc_smcd);
990 	if (ini->smc_type_v1 != SMC_TYPE_N) {
991 		vec[i].iov_base = pclc_prfx;
992 		vec[i++].iov_len = sizeof(*pclc_prfx);
993 		if (pclc_prfx->ipv6_prefixes_cnt > 0) {
994 			vec[i].iov_base = ipv6_prfx;
995 			vec[i++].iov_len = pclc_prfx->ipv6_prefixes_cnt *
996 					   sizeof(ipv6_prfx[0]);
997 		}
998 	}
999 	if (ini->smc_type_v2 != SMC_TYPE_N) {
1000 		vec[i].iov_base = v2_ext;
1001 		vec[i++].iov_len = sizeof(*v2_ext) +
1002 				   (v2_ext->hdr.eid_cnt * SMC_MAX_EID_LEN);
1003 		if (smcd_indicated(ini->smc_type_v2)) {
1004 			vec[i].iov_base = smcd_v2_ext;
1005 			vec[i++].iov_len = sizeof(*smcd_v2_ext);
1006 			if (ini->ism_offered_cnt) {
1007 				vec[i].iov_base = gidchids;
1008 				vec[i++].iov_len = v2_ext->hdr.ism_gid_cnt *
1009 					sizeof(struct smc_clc_smcd_gid_chid);
1010 			}
1011 		}
1012 	}
1013 	vec[i].iov_base = trl;
1014 	vec[i++].iov_len = sizeof(*trl);
1015 	/* due to the few bytes needed for clc-handshake this cannot block */
1016 	len = kernel_sendmsg(smc->clcsock, &msg, vec, i, plen);
1017 	if (len < 0) {
1018 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
1019 		reason_code = -smc->sk.sk_err;
1020 	} else if (len < ntohs(pclc_base->hdr.length)) {
1021 		reason_code = -ENETUNREACH;
1022 		smc->sk.sk_err = -reason_code;
1023 	}
1024 
1025 	kfree(pclc);
1026 	return reason_code;
1027 }
1028 
1029 static void
1030 smcd_clc_prep_confirm_accept(struct smc_connection *conn,
1031 			     struct smc_clc_msg_accept_confirm *clc,
1032 			     int first_contact, u8 version,
1033 			     u8 *eid, struct smc_init_info *ini,
1034 			     int *fce_len,
1035 			     struct smc_clc_first_contact_ext_v2x *fce_v2x,
1036 			     struct smc_clc_msg_trail *trl)
1037 {
1038 	struct smcd_dev *smcd = conn->lgr->smcd;
1039 	struct smcd_gid smcd_gid;
1040 	u16 chid;
1041 	int len;
1042 
1043 	/* SMC-D specific settings */
1044 	memcpy(clc->hdr.eyecatcher, SMCD_EYECATCHER,
1045 	       sizeof(SMCD_EYECATCHER));
1046 	smcd->ops->get_local_gid(smcd, &smcd_gid);
1047 	clc->hdr.typev1 = SMC_TYPE_D;
1048 	clc->d0.gid = htonll(smcd_gid.gid);
1049 	clc->d0.token = htonll(conn->rmb_desc->token);
1050 	clc->d0.dmbe_size = conn->rmbe_size_comp;
1051 	clc->d0.dmbe_idx = 0;
1052 	memcpy(&clc->d0.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
1053 	if (version == SMC_V1) {
1054 		clc->hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
1055 	} else {
1056 		chid = smc_ism_get_chid(smcd);
1057 		clc->d1.chid = htons(chid);
1058 		if (eid && eid[0])
1059 			memcpy(clc->d1.eid, eid, SMC_MAX_EID_LEN);
1060 		if (__smc_ism_is_emulated(chid))
1061 			clc->d1.gid_ext = htonll(smcd_gid.gid_ext);
1062 		len = SMCD_CLC_ACCEPT_CONFIRM_LEN_V2;
1063 		if (first_contact) {
1064 			*fce_len = smc_clc_fill_fce_v2x(fce_v2x, ini);
1065 			len += *fce_len;
1066 		}
1067 		clc->hdr.length = htons(len);
1068 	}
1069 	memcpy(trl->eyecatcher, SMCD_EYECATCHER,
1070 	       sizeof(SMCD_EYECATCHER));
1071 }
1072 
1073 static void
1074 smcr_clc_prep_confirm_accept(struct smc_connection *conn,
1075 			     struct smc_clc_msg_accept_confirm *clc,
1076 			     int first_contact, u8 version,
1077 			     u8 *eid, struct smc_init_info *ini,
1078 			     int *fce_len,
1079 			     struct smc_clc_first_contact_ext_v2x *fce_v2x,
1080 			     struct smc_clc_fce_gid_ext *gle,
1081 			     struct smc_clc_msg_trail *trl)
1082 {
1083 	struct smc_link *link = conn->lnk;
1084 	int len;
1085 
1086 	/* SMC-R specific settings */
1087 	memcpy(clc->hdr.eyecatcher, SMC_EYECATCHER,
1088 	       sizeof(SMC_EYECATCHER));
1089 	clc->hdr.typev1 = SMC_TYPE_R;
1090 	memcpy(clc->r0.lcl.id_for_peer, local_systemid,
1091 	       sizeof(local_systemid));
1092 	memcpy(&clc->r0.lcl.gid, link->gid, SMC_GID_SIZE);
1093 	memcpy(&clc->r0.lcl.mac, &link->smcibdev->mac[link->ibport - 1],
1094 	       ETH_ALEN);
1095 	hton24(clc->r0.qpn, link->roce_qp->qp_num);
1096 	clc->r0.rmb_rkey =
1097 		htonl(conn->rmb_desc->mr[link->link_idx]->rkey);
1098 	clc->r0.rmbe_idx = 1; /* for now: 1 RMB = 1 RMBE */
1099 	clc->r0.rmbe_alert_token = htonl(conn->alert_token_local);
1100 	switch (clc->hdr.type) {
1101 	case SMC_CLC_ACCEPT:
1102 		clc->r0.qp_mtu = link->path_mtu;
1103 		break;
1104 	case SMC_CLC_CONFIRM:
1105 		clc->r0.qp_mtu = min(link->path_mtu, link->peer_mtu);
1106 		break;
1107 	}
1108 	clc->r0.rmbe_size = conn->rmbe_size_comp;
1109 	clc->r0.rmb_dma_addr = conn->rmb_desc->is_vm ?
1110 		cpu_to_be64((uintptr_t)conn->rmb_desc->cpu_addr) :
1111 		cpu_to_be64((u64)sg_dma_address
1112 			    (conn->rmb_desc->sgt[link->link_idx].sgl));
1113 	hton24(clc->r0.psn, link->psn_initial);
1114 	if (version == SMC_V1) {
1115 		clc->hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
1116 	} else {
1117 		if (eid && eid[0])
1118 			memcpy(clc->r1.eid, eid, SMC_MAX_EID_LEN);
1119 		len = SMCR_CLC_ACCEPT_CONFIRM_LEN_V2;
1120 		if (first_contact) {
1121 			*fce_len = smc_clc_fill_fce_v2x(fce_v2x, ini);
1122 			len += *fce_len;
1123 			fce_v2x->fce_v2_base.v2_direct =
1124 				!link->lgr->uses_gateway;
1125 			if (clc->hdr.type == SMC_CLC_CONFIRM) {
1126 				memset(gle, 0, sizeof(*gle));
1127 				gle->gid_cnt = ini->smcrv2.gidlist.len;
1128 				len += sizeof(*gle);
1129 				len += gle->gid_cnt * sizeof(gle->gid[0]);
1130 			}
1131 		}
1132 		clc->hdr.length = htons(len);
1133 	}
1134 	memcpy(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
1135 }
1136 
1137 /* build and send CLC CONFIRM / ACCEPT message */
1138 static int smc_clc_send_confirm_accept(struct smc_sock *smc,
1139 				       struct smc_clc_msg_accept_confirm *clc,
1140 				       int first_contact, u8 version,
1141 				       u8 *eid, struct smc_init_info *ini)
1142 {
1143 	struct smc_clc_first_contact_ext_v2x fce_v2x;
1144 	struct smc_connection *conn = &smc->conn;
1145 	struct smc_clc_fce_gid_ext gle;
1146 	struct smc_clc_msg_trail trl;
1147 	int i, fce_len;
1148 	struct kvec vec[5];
1149 	struct msghdr msg;
1150 
1151 	/* send SMC Confirm CLC msg */
1152 	clc->hdr.version = version;	/* SMC version */
1153 	if (first_contact)
1154 		clc->hdr.typev2 |= SMC_FIRST_CONTACT_MASK;
1155 	if (conn->lgr->is_smcd)
1156 		smcd_clc_prep_confirm_accept(conn, clc, first_contact,
1157 					     version, eid, ini, &fce_len,
1158 					     &fce_v2x, &trl);
1159 	else
1160 		smcr_clc_prep_confirm_accept(conn, clc, first_contact,
1161 					     version, eid, ini, &fce_len,
1162 					     &fce_v2x, &gle, &trl);
1163 	memset(&msg, 0, sizeof(msg));
1164 	i = 0;
1165 	vec[i].iov_base = clc;
1166 	if (version > SMC_V1)
1167 		vec[i++].iov_len = (clc->hdr.typev1 == SMC_TYPE_D ?
1168 					SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 :
1169 					SMCR_CLC_ACCEPT_CONFIRM_LEN_V2) -
1170 				   sizeof(trl);
1171 	else
1172 		vec[i++].iov_len = (clc->hdr.typev1 == SMC_TYPE_D ?
1173 						SMCD_CLC_ACCEPT_CONFIRM_LEN :
1174 						SMCR_CLC_ACCEPT_CONFIRM_LEN) -
1175 				   sizeof(trl);
1176 	if (version > SMC_V1 && first_contact) {
1177 		vec[i].iov_base = &fce_v2x;
1178 		vec[i++].iov_len = fce_len;
1179 		if (!conn->lgr->is_smcd) {
1180 			if (clc->hdr.type == SMC_CLC_CONFIRM) {
1181 				vec[i].iov_base = &gle;
1182 				vec[i++].iov_len = sizeof(gle);
1183 				vec[i].iov_base = &ini->smcrv2.gidlist.list;
1184 				vec[i++].iov_len = gle.gid_cnt *
1185 						   sizeof(gle.gid[0]);
1186 			}
1187 		}
1188 	}
1189 	vec[i].iov_base = &trl;
1190 	vec[i++].iov_len = sizeof(trl);
1191 	return kernel_sendmsg(smc->clcsock, &msg, vec, 1,
1192 			      ntohs(clc->hdr.length));
1193 }
1194 
1195 /* send CLC CONFIRM message across internal TCP socket */
1196 int smc_clc_send_confirm(struct smc_sock *smc, bool clnt_first_contact,
1197 			 u8 version, u8 *eid, struct smc_init_info *ini)
1198 {
1199 	struct smc_clc_msg_accept_confirm cclc;
1200 	int reason_code = 0;
1201 	int len;
1202 
1203 	/* send SMC Confirm CLC msg */
1204 	memset(&cclc, 0, sizeof(cclc));
1205 	cclc.hdr.type = SMC_CLC_CONFIRM;
1206 	len = smc_clc_send_confirm_accept(smc, &cclc, clnt_first_contact,
1207 					  version, eid, ini);
1208 	if (len < ntohs(cclc.hdr.length)) {
1209 		if (len >= 0) {
1210 			reason_code = -ENETUNREACH;
1211 			smc->sk.sk_err = -reason_code;
1212 		} else {
1213 			smc->sk.sk_err = smc->clcsock->sk->sk_err;
1214 			reason_code = -smc->sk.sk_err;
1215 		}
1216 	}
1217 	return reason_code;
1218 }
1219 
1220 /* send CLC ACCEPT message across internal TCP socket */
1221 int smc_clc_send_accept(struct smc_sock *new_smc, bool srv_first_contact,
1222 			u8 version, u8 *negotiated_eid, struct smc_init_info *ini)
1223 {
1224 	struct smc_clc_msg_accept_confirm aclc;
1225 	int len;
1226 
1227 	memset(&aclc, 0, sizeof(aclc));
1228 	aclc.hdr.type = SMC_CLC_ACCEPT;
1229 	len = smc_clc_send_confirm_accept(new_smc, &aclc, srv_first_contact,
1230 					  version, negotiated_eid, ini);
1231 	if (len < ntohs(aclc.hdr.length))
1232 		len = len >= 0 ? -EPROTO : -new_smc->clcsock->sk->sk_err;
1233 
1234 	return len > 0 ? 0 : len;
1235 }
1236 
1237 int smc_clc_srv_v2x_features_validate(struct smc_sock *smc,
1238 				      struct smc_clc_msg_proposal *pclc,
1239 				      struct smc_init_info *ini)
1240 {
1241 	struct smc_clc_v2_extension *pclc_v2_ext;
1242 	struct net *net = sock_net(&smc->sk);
1243 
1244 	ini->max_conns = SMC_CONN_PER_LGR_MAX;
1245 	ini->max_links = SMC_LINKS_ADD_LNK_MAX;
1246 	ini->feature_mask = SMC_FEATURE_MASK;
1247 
1248 	if ((!(ini->smcd_version & SMC_V2) && !(ini->smcr_version & SMC_V2)) ||
1249 	    ini->release_nr < SMC_RELEASE_1)
1250 		return 0;
1251 
1252 	pclc_v2_ext = smc_get_clc_v2_ext(pclc);
1253 	if (!pclc_v2_ext)
1254 		return SMC_CLC_DECL_NOV2EXT;
1255 
1256 	if (ini->smcr_version & SMC_V2) {
1257 		ini->max_conns = min_t(u8, pclc_v2_ext->max_conns,
1258 				       net->smc.sysctl_max_conns_per_lgr);
1259 		if (ini->max_conns < SMC_CONN_PER_LGR_MIN)
1260 			return SMC_CLC_DECL_MAXCONNERR;
1261 
1262 		ini->max_links = min_t(u8, pclc_v2_ext->max_links,
1263 				       net->smc.sysctl_max_links_per_lgr);
1264 		if (ini->max_links < SMC_LINKS_ADD_LNK_MIN)
1265 			return SMC_CLC_DECL_MAXLINKERR;
1266 	}
1267 
1268 	return 0;
1269 }
1270 
1271 int smc_clc_clnt_v2x_features_validate(struct smc_clc_first_contact_ext *fce,
1272 				       struct smc_init_info *ini)
1273 {
1274 	struct smc_clc_first_contact_ext_v2x *fce_v2x =
1275 		(struct smc_clc_first_contact_ext_v2x *)fce;
1276 
1277 	if (ini->release_nr < SMC_RELEASE_1)
1278 		return 0;
1279 
1280 	if (!ini->is_smcd) {
1281 		if (fce_v2x->max_conns < SMC_CONN_PER_LGR_MIN)
1282 			return SMC_CLC_DECL_MAXCONNERR;
1283 		ini->max_conns = fce_v2x->max_conns;
1284 
1285 		if (fce_v2x->max_links > SMC_LINKS_ADD_LNK_MAX ||
1286 		    fce_v2x->max_links < SMC_LINKS_ADD_LNK_MIN)
1287 			return SMC_CLC_DECL_MAXLINKERR;
1288 		ini->max_links = fce_v2x->max_links;
1289 	}
1290 	/* common supplemental features of server and client */
1291 	ini->feature_mask = ntohs(fce_v2x->feature_mask) & SMC_FEATURE_MASK;
1292 
1293 	return 0;
1294 }
1295 
1296 int smc_clc_v2x_features_confirm_check(struct smc_clc_msg_accept_confirm *cclc,
1297 				       struct smc_init_info *ini)
1298 {
1299 	struct smc_clc_first_contact_ext *fce =
1300 		smc_get_clc_first_contact_ext(cclc, ini->is_smcd);
1301 	struct smc_clc_first_contact_ext_v2x *fce_v2x =
1302 		(struct smc_clc_first_contact_ext_v2x *)fce;
1303 
1304 	if (cclc->hdr.version == SMC_V1 ||
1305 	    !(cclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
1306 		return 0;
1307 
1308 	if (ini->release_nr != fce->release)
1309 		return SMC_CLC_DECL_RELEASEERR;
1310 
1311 	if (fce->release < SMC_RELEASE_1)
1312 		return 0;
1313 
1314 	if (!ini->is_smcd) {
1315 		if (fce_v2x->max_conns != ini->max_conns)
1316 			return SMC_CLC_DECL_MAXCONNERR;
1317 		if (fce_v2x->max_links != ini->max_links)
1318 			return SMC_CLC_DECL_MAXLINKERR;
1319 	}
1320 	/* common supplemental features returned by client */
1321 	ini->feature_mask = ntohs(fce_v2x->feature_mask);
1322 
1323 	return 0;
1324 }
1325 
1326 void smc_clc_get_hostname(u8 **host)
1327 {
1328 	*host = &smc_hostname[0];
1329 }
1330 
1331 void __init smc_clc_init(void)
1332 {
1333 	struct new_utsname *u;
1334 
1335 	memset(smc_hostname, _S, sizeof(smc_hostname)); /* ASCII blanks */
1336 	u = utsname();
1337 	memcpy(smc_hostname, u->nodename,
1338 	       min_t(size_t, strlen(u->nodename), sizeof(smc_hostname)));
1339 
1340 	INIT_LIST_HEAD(&smc_clc_eid_table.list);
1341 	rwlock_init(&smc_clc_eid_table.lock);
1342 	smc_clc_eid_table.ueid_cnt = 0;
1343 #if IS_ENABLED(CONFIG_S390)
1344 	smc_clc_eid_table.seid_enabled = 1;
1345 #else
1346 	smc_clc_eid_table.seid_enabled = 0;
1347 #endif
1348 }
1349 
1350 void smc_clc_exit(void)
1351 {
1352 	smc_clc_ueid_remove(NULL);
1353 }
1354