xref: /linux/net/smc/smc_clc.c (revision 3191df0a4882c827cac29925e80ecb1775b904bd)
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 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
356 	if (!pclc_prfx ||
357 	    pclc_prfx->ipv6_prefixes_cnt > SMC_CLC_MAX_V6_PREFIX)
358 		return false;
359 
360 	if (hdr->version == SMC_V1) {
361 		if (hdr->typev1 == SMC_TYPE_N)
362 			return false;
363 		if (ntohs(hdr->length) !=
364 			sizeof(*pclc) + ntohs(pclc->iparea_offset) +
365 			sizeof(*pclc_prfx) +
366 			pclc_prfx->ipv6_prefixes_cnt *
367 				sizeof(struct smc_clc_ipv6_prefix) +
368 			sizeof(struct smc_clc_msg_trail))
369 			return false;
370 	} else {
371 		v2_ext = smc_get_clc_v2_ext(pclc);
372 		if ((hdr->typev2 != SMC_TYPE_N &&
373 		     (!v2_ext || v2_ext->hdr.eid_cnt > SMC_CLC_MAX_UEID)) ||
374 		    (smcd_indicated(hdr->typev2) &&
375 		     v2_ext->hdr.ism_gid_cnt > SMCD_CLC_MAX_V2_GID_ENTRIES))
376 			return false;
377 
378 		if (ntohs(hdr->length) !=
379 			sizeof(*pclc) +
380 			sizeof(struct smc_clc_msg_smcd) +
381 			(hdr->typev1 != SMC_TYPE_N ?
382 				sizeof(*pclc_prfx) +
383 				pclc_prfx->ipv6_prefixes_cnt *
384 				sizeof(struct smc_clc_ipv6_prefix) : 0) +
385 			(hdr->typev2 != SMC_TYPE_N ?
386 				sizeof(*v2_ext) +
387 				v2_ext->hdr.eid_cnt * SMC_MAX_EID_LEN : 0) +
388 			(smcd_indicated(hdr->typev2) ?
389 				sizeof(*smcd_v2_ext) + v2_ext->hdr.ism_gid_cnt *
390 					sizeof(struct smc_clc_smcd_gid_chid) :
391 				0) +
392 			sizeof(struct smc_clc_msg_trail))
393 			return false;
394 	}
395 	return true;
396 }
397 
398 /* check arriving CLC accept or confirm */
399 static bool
400 smc_clc_msg_acc_conf_valid(struct smc_clc_msg_accept_confirm *clc)
401 {
402 	struct smc_clc_msg_hdr *hdr = &clc->hdr;
403 
404 	if (hdr->typev1 != SMC_TYPE_R && hdr->typev1 != SMC_TYPE_D)
405 		return false;
406 	if (hdr->version == SMC_V1) {
407 		if ((hdr->typev1 == SMC_TYPE_R &&
408 		     ntohs(hdr->length) != SMCR_CLC_ACCEPT_CONFIRM_LEN) ||
409 		    (hdr->typev1 == SMC_TYPE_D &&
410 		     ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN))
411 			return false;
412 	} else {
413 		if (hdr->typev1 == SMC_TYPE_D &&
414 		    ntohs(hdr->length) < SMCD_CLC_ACCEPT_CONFIRM_LEN_V2)
415 			return false;
416 		if (hdr->typev1 == SMC_TYPE_R &&
417 		    ntohs(hdr->length) < SMCR_CLC_ACCEPT_CONFIRM_LEN_V2)
418 			return false;
419 	}
420 	return true;
421 }
422 
423 /* check arriving CLC decline */
424 static bool
425 smc_clc_msg_decl_valid(struct smc_clc_msg_decline *dclc)
426 {
427 	struct smc_clc_msg_hdr *hdr = &dclc->hdr;
428 
429 	if (hdr->version == SMC_V1) {
430 		if (ntohs(hdr->length) != sizeof(struct smc_clc_msg_decline))
431 			return false;
432 	} else {
433 		if (ntohs(hdr->length) != sizeof(struct smc_clc_msg_decline_v2))
434 			return false;
435 	}
436 	return true;
437 }
438 
439 static int smc_clc_fill_fce_v2x(struct smc_clc_first_contact_ext_v2x *fce_v2x,
440 				struct smc_init_info *ini)
441 {
442 	int ret = sizeof(*fce_v2x);
443 
444 	memset(fce_v2x, 0, sizeof(*fce_v2x));
445 	fce_v2x->fce_v2_base.os_type = SMC_CLC_OS_LINUX;
446 	fce_v2x->fce_v2_base.release = ini->release_nr;
447 	memcpy(fce_v2x->fce_v2_base.hostname,
448 	       smc_hostname, sizeof(smc_hostname));
449 	if (ini->is_smcd && ini->release_nr < SMC_RELEASE_1) {
450 		ret = sizeof(struct smc_clc_first_contact_ext);
451 		goto out;
452 	}
453 
454 	if (ini->release_nr >= SMC_RELEASE_1) {
455 		if (!ini->is_smcd) {
456 			fce_v2x->max_conns = ini->max_conns;
457 			fce_v2x->max_links = ini->max_links;
458 		}
459 		fce_v2x->feature_mask = htons(ini->feature_mask);
460 	}
461 
462 out:
463 	return ret;
464 }
465 
466 /* check if received message has a correct header length and contains valid
467  * heading and trailing eyecatchers
468  */
469 static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm, bool check_trl)
470 {
471 	struct smc_clc_msg_accept_confirm *clc;
472 	struct smc_clc_msg_proposal *pclc;
473 	struct smc_clc_msg_decline *dclc;
474 	struct smc_clc_msg_trail *trl;
475 
476 	if (memcmp(clcm->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
477 	    memcmp(clcm->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
478 		return false;
479 	switch (clcm->type) {
480 	case SMC_CLC_PROPOSAL:
481 		pclc = (struct smc_clc_msg_proposal *)clcm;
482 		if (!smc_clc_msg_prop_valid(pclc))
483 			return false;
484 		trl = (struct smc_clc_msg_trail *)
485 			((u8 *)pclc + ntohs(pclc->hdr.length) - sizeof(*trl));
486 		break;
487 	case SMC_CLC_ACCEPT:
488 	case SMC_CLC_CONFIRM:
489 		clc = (struct smc_clc_msg_accept_confirm *)clcm;
490 		if (!smc_clc_msg_acc_conf_valid(clc))
491 			return false;
492 		trl = (struct smc_clc_msg_trail *)
493 			((u8 *)clc + ntohs(clc->hdr.length) - sizeof(*trl));
494 		break;
495 	case SMC_CLC_DECLINE:
496 		dclc = (struct smc_clc_msg_decline *)clcm;
497 		if (!smc_clc_msg_decl_valid(dclc))
498 			return false;
499 		check_trl = false;
500 		break;
501 	default:
502 		return false;
503 	}
504 	if (check_trl &&
505 	    memcmp(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
506 	    memcmp(trl->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
507 		return false;
508 	return true;
509 }
510 
511 /* find ipv4 addr on device and get the prefix len, fill CLC proposal msg */
512 static int smc_clc_prfx_set4_rcu(struct dst_entry *dst, __be32 ipv4,
513 				 struct smc_clc_msg_proposal_prefix *prop)
514 {
515 	struct in_device *in_dev = __in_dev_get_rcu(dst->dev);
516 	const struct in_ifaddr *ifa;
517 
518 	if (!in_dev)
519 		return -ENODEV;
520 
521 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
522 		if (!inet_ifa_match(ipv4, ifa))
523 			continue;
524 		prop->prefix_len = inet_mask_len(ifa->ifa_mask);
525 		prop->outgoing_subnet = ifa->ifa_address & ifa->ifa_mask;
526 		/* prop->ipv6_prefixes_cnt = 0; already done by memset before */
527 		return 0;
528 	}
529 	return -ENOENT;
530 }
531 
532 /* fill CLC proposal msg with ipv6 prefixes from device */
533 static int smc_clc_prfx_set6_rcu(struct dst_entry *dst,
534 				 struct smc_clc_msg_proposal_prefix *prop,
535 				 struct smc_clc_ipv6_prefix *ipv6_prfx)
536 {
537 #if IS_ENABLED(CONFIG_IPV6)
538 	struct inet6_dev *in6_dev = __in6_dev_get(dst->dev);
539 	struct inet6_ifaddr *ifa;
540 	int cnt = 0;
541 
542 	if (!in6_dev)
543 		return -ENODEV;
544 	/* use a maximum of 8 IPv6 prefixes from device */
545 	list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
546 		if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
547 			continue;
548 		ipv6_addr_prefix(&ipv6_prfx[cnt].prefix,
549 				 &ifa->addr, ifa->prefix_len);
550 		ipv6_prfx[cnt].prefix_len = ifa->prefix_len;
551 		cnt++;
552 		if (cnt == SMC_CLC_MAX_V6_PREFIX)
553 			break;
554 	}
555 	prop->ipv6_prefixes_cnt = cnt;
556 	if (cnt)
557 		return 0;
558 #endif
559 	return -ENOENT;
560 }
561 
562 /* retrieve and set prefixes in CLC proposal msg */
563 static int smc_clc_prfx_set(struct socket *clcsock,
564 			    struct smc_clc_msg_proposal_prefix *prop,
565 			    struct smc_clc_ipv6_prefix *ipv6_prfx)
566 {
567 	struct dst_entry *dst = sk_dst_get(clcsock->sk);
568 	struct sockaddr_storage addrs;
569 	struct sockaddr_in6 *addr6;
570 	struct sockaddr_in *addr;
571 	int rc = -ENOENT;
572 
573 	if (!dst) {
574 		rc = -ENOTCONN;
575 		goto out;
576 	}
577 	if (!dst->dev) {
578 		rc = -ENODEV;
579 		goto out_rel;
580 	}
581 	/* get address to which the internal TCP socket is bound */
582 	if (kernel_getsockname(clcsock, (struct sockaddr *)&addrs) < 0)
583 		goto out_rel;
584 	/* analyze IP specific data of net_device belonging to TCP socket */
585 	addr6 = (struct sockaddr_in6 *)&addrs;
586 	rcu_read_lock();
587 	if (addrs.ss_family == PF_INET) {
588 		/* IPv4 */
589 		addr = (struct sockaddr_in *)&addrs;
590 		rc = smc_clc_prfx_set4_rcu(dst, addr->sin_addr.s_addr, prop);
591 	} else if (ipv6_addr_v4mapped(&addr6->sin6_addr)) {
592 		/* mapped IPv4 address - peer is IPv4 only */
593 		rc = smc_clc_prfx_set4_rcu(dst, addr6->sin6_addr.s6_addr32[3],
594 					   prop);
595 	} else {
596 		/* IPv6 */
597 		rc = smc_clc_prfx_set6_rcu(dst, prop, ipv6_prfx);
598 	}
599 	rcu_read_unlock();
600 out_rel:
601 	dst_release(dst);
602 out:
603 	return rc;
604 }
605 
606 /* match ipv4 addrs of dev against addr in CLC proposal */
607 static int smc_clc_prfx_match4_rcu(struct net_device *dev,
608 				   struct smc_clc_msg_proposal_prefix *prop)
609 {
610 	struct in_device *in_dev = __in_dev_get_rcu(dev);
611 	const struct in_ifaddr *ifa;
612 
613 	if (!in_dev)
614 		return -ENODEV;
615 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
616 		if (prop->prefix_len == inet_mask_len(ifa->ifa_mask) &&
617 		    inet_ifa_match(prop->outgoing_subnet, ifa))
618 			return 0;
619 	}
620 
621 	return -ENOENT;
622 }
623 
624 /* match ipv6 addrs of dev against addrs in CLC proposal */
625 static int smc_clc_prfx_match6_rcu(struct net_device *dev,
626 				   struct smc_clc_msg_proposal_prefix *prop)
627 {
628 #if IS_ENABLED(CONFIG_IPV6)
629 	struct inet6_dev *in6_dev = __in6_dev_get(dev);
630 	struct smc_clc_ipv6_prefix *ipv6_prfx;
631 	struct inet6_ifaddr *ifa;
632 	int i, max;
633 
634 	if (!in6_dev)
635 		return -ENODEV;
636 	/* ipv6 prefix list starts behind smc_clc_msg_proposal_prefix */
637 	ipv6_prfx = (struct smc_clc_ipv6_prefix *)((u8 *)prop + sizeof(*prop));
638 	max = min_t(u8, prop->ipv6_prefixes_cnt, SMC_CLC_MAX_V6_PREFIX);
639 	list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
640 		if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
641 			continue;
642 		for (i = 0; i < max; i++) {
643 			if (ifa->prefix_len == ipv6_prfx[i].prefix_len &&
644 			    ipv6_prefix_equal(&ifa->addr, &ipv6_prfx[i].prefix,
645 					      ifa->prefix_len))
646 				return 0;
647 		}
648 	}
649 #endif
650 	return -ENOENT;
651 }
652 
653 /* check if proposed prefixes match one of our device prefixes */
654 int smc_clc_prfx_match(struct socket *clcsock,
655 		       struct smc_clc_msg_proposal_prefix *prop)
656 {
657 	struct dst_entry *dst = sk_dst_get(clcsock->sk);
658 	int rc;
659 
660 	if (!dst) {
661 		rc = -ENOTCONN;
662 		goto out;
663 	}
664 	if (!dst->dev) {
665 		rc = -ENODEV;
666 		goto out_rel;
667 	}
668 	rcu_read_lock();
669 	if (!prop->ipv6_prefixes_cnt)
670 		rc = smc_clc_prfx_match4_rcu(dst->dev, prop);
671 	else
672 		rc = smc_clc_prfx_match6_rcu(dst->dev, prop);
673 	rcu_read_unlock();
674 out_rel:
675 	dst_release(dst);
676 out:
677 	return rc;
678 }
679 
680 /* Wait for data on the tcp-socket, analyze received data
681  * Returns:
682  * 0 if success and it was not a decline that we received.
683  * SMC_CLC_DECL_REPLY if decline received for fallback w/o another decl send.
684  * clcsock error, -EINTR, -ECONNRESET, -EPROTO otherwise.
685  */
686 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
687 		     u8 expected_type, unsigned long timeout)
688 {
689 	long rcvtimeo = READ_ONCE(smc->clcsock->sk->sk_rcvtimeo);
690 	struct sock *clc_sk = smc->clcsock->sk;
691 	struct smc_clc_msg_hdr *clcm = buf;
692 	struct msghdr msg = {NULL, 0};
693 	int reason_code = 0;
694 	struct kvec vec = {buf, buflen};
695 	int len, datlen, recvlen;
696 	bool check_trl = true;
697 	int krflags;
698 
699 	/* peek the first few bytes to determine length of data to receive
700 	 * so we don't consume any subsequent CLC message or payload data
701 	 * in the TCP byte stream
702 	 */
703 	/*
704 	 * Caller must make sure that buflen is no less than
705 	 * sizeof(struct smc_clc_msg_hdr)
706 	 */
707 	krflags = MSG_PEEK | MSG_WAITALL;
708 	WRITE_ONCE(clc_sk->sk_rcvtimeo, timeout);
709 	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &vec, 1,
710 			sizeof(struct smc_clc_msg_hdr));
711 	len = sock_recvmsg(smc->clcsock, &msg, krflags);
712 	if (signal_pending(current)) {
713 		reason_code = -EINTR;
714 		clc_sk->sk_err = EINTR;
715 		smc->sk.sk_err = EINTR;
716 		goto out;
717 	}
718 	if (clc_sk->sk_err) {
719 		reason_code = -clc_sk->sk_err;
720 		if (clc_sk->sk_err == EAGAIN &&
721 		    expected_type == SMC_CLC_DECLINE)
722 			clc_sk->sk_err = 0; /* reset for fallback usage */
723 		else
724 			smc->sk.sk_err = clc_sk->sk_err;
725 		goto out;
726 	}
727 	if (!len) { /* peer has performed orderly shutdown */
728 		smc->sk.sk_err = ECONNRESET;
729 		reason_code = -ECONNRESET;
730 		goto out;
731 	}
732 	if (len < 0) {
733 		if (len != -EAGAIN || expected_type != SMC_CLC_DECLINE)
734 			smc->sk.sk_err = -len;
735 		reason_code = len;
736 		goto out;
737 	}
738 	datlen = ntohs(clcm->length);
739 	if ((len < sizeof(struct smc_clc_msg_hdr)) ||
740 	    (clcm->version < SMC_V1) ||
741 	    ((clcm->type != SMC_CLC_DECLINE) &&
742 	     (clcm->type != expected_type))) {
743 		smc->sk.sk_err = EPROTO;
744 		reason_code = -EPROTO;
745 		goto out;
746 	}
747 
748 	/* receive the complete CLC message */
749 	memset(&msg, 0, sizeof(struct msghdr));
750 	if (datlen > buflen) {
751 		check_trl = false;
752 		recvlen = buflen;
753 	} else {
754 		recvlen = datlen;
755 	}
756 	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &vec, 1, recvlen);
757 	krflags = MSG_WAITALL;
758 	len = sock_recvmsg(smc->clcsock, &msg, krflags);
759 	if (len < recvlen || !smc_clc_msg_hdr_valid(clcm, check_trl)) {
760 		smc->sk.sk_err = EPROTO;
761 		reason_code = -EPROTO;
762 		goto out;
763 	}
764 	datlen -= len;
765 	while (datlen) {
766 		u8 tmp[SMC_CLC_RECV_BUF_LEN];
767 
768 		vec.iov_base = &tmp;
769 		vec.iov_len = SMC_CLC_RECV_BUF_LEN;
770 		/* receive remaining proposal message */
771 		recvlen = datlen > SMC_CLC_RECV_BUF_LEN ?
772 						SMC_CLC_RECV_BUF_LEN : datlen;
773 		iov_iter_kvec(&msg.msg_iter, ITER_DEST, &vec, 1, recvlen);
774 		len = sock_recvmsg(smc->clcsock, &msg, krflags);
775 		if (len < recvlen) {
776 			smc->sk.sk_err = EPROTO;
777 			reason_code = -EPROTO;
778 			goto out;
779 		}
780 		datlen -= len;
781 	}
782 	if (clcm->type == SMC_CLC_DECLINE) {
783 		struct smc_clc_msg_decline *dclc;
784 
785 		dclc = (struct smc_clc_msg_decline *)clcm;
786 		reason_code = SMC_CLC_DECL_PEERDECL;
787 		smc->peer_diagnosis = ntohl(dclc->peer_diagnosis);
788 		if (((struct smc_clc_msg_decline *)buf)->hdr.typev2 &
789 						SMC_FIRST_CONTACT_MASK) {
790 			smc->conn.lgr->sync_err = 1;
791 			smc_lgr_terminate_sched(smc->conn.lgr);
792 		}
793 	}
794 
795 out:
796 	WRITE_ONCE(clc_sk->sk_rcvtimeo, rcvtimeo);
797 	return reason_code;
798 }
799 
800 /* send CLC DECLINE message across internal TCP socket */
801 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info, u8 version)
802 {
803 	struct smc_clc_msg_decline *dclc_v1;
804 	struct smc_clc_msg_decline_v2 dclc;
805 	struct msghdr msg;
806 	int len, send_len;
807 	struct kvec vec;
808 
809 	dclc_v1 = (struct smc_clc_msg_decline *)&dclc;
810 	memset(&dclc, 0, sizeof(dclc));
811 	memcpy(dclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
812 	dclc.hdr.type = SMC_CLC_DECLINE;
813 	dclc.hdr.version = version;
814 	dclc.os_type = version == SMC_V1 ? 0 : SMC_CLC_OS_LINUX;
815 	dclc.hdr.typev2 = (peer_diag_info == SMC_CLC_DECL_SYNCERR) ?
816 						SMC_FIRST_CONTACT_MASK : 0;
817 	if ((!smc_conn_lgr_valid(&smc->conn) || !smc->conn.lgr->is_smcd) &&
818 	    smc_ib_is_valid_local_systemid())
819 		memcpy(dclc.id_for_peer, local_systemid,
820 		       sizeof(local_systemid));
821 	dclc.peer_diagnosis = htonl(peer_diag_info);
822 	if (version == SMC_V1) {
823 		memcpy(dclc_v1->trl.eyecatcher, SMC_EYECATCHER,
824 		       sizeof(SMC_EYECATCHER));
825 		send_len = sizeof(*dclc_v1);
826 	} else {
827 		memcpy(dclc.trl.eyecatcher, SMC_EYECATCHER,
828 		       sizeof(SMC_EYECATCHER));
829 		send_len = sizeof(dclc);
830 	}
831 	dclc.hdr.length = htons(send_len);
832 
833 	memset(&msg, 0, sizeof(msg));
834 	vec.iov_base = &dclc;
835 	vec.iov_len = send_len;
836 	len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1, send_len);
837 	if (len < 0 || len < send_len)
838 		len = -EPROTO;
839 	return len > 0 ? 0 : len;
840 }
841 
842 /* send CLC PROPOSAL message across internal TCP socket */
843 int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini)
844 {
845 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
846 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
847 	struct smc_clc_msg_proposal *pclc_base;
848 	struct smc_clc_smcd_gid_chid *gidchids;
849 	struct smc_clc_msg_proposal_area *pclc;
850 	struct smc_clc_ipv6_prefix *ipv6_prfx;
851 	struct net *net = sock_net(&smc->sk);
852 	struct smc_clc_v2_extension *v2_ext;
853 	struct smc_clc_msg_smcd *pclc_smcd;
854 	struct smc_clc_msg_trail *trl;
855 	struct smcd_dev *smcd;
856 	int len, i, plen, rc;
857 	int reason_code = 0;
858 	struct kvec vec[8];
859 	struct msghdr msg;
860 
861 	pclc = kzalloc(sizeof(*pclc), GFP_KERNEL);
862 	if (!pclc)
863 		return -ENOMEM;
864 
865 	pclc_base = &pclc->pclc_base;
866 	pclc_smcd = &pclc->pclc_smcd;
867 	pclc_prfx = &pclc->pclc_prfx;
868 	ipv6_prfx = pclc->pclc_prfx_ipv6;
869 	v2_ext = container_of(&pclc->pclc_v2_ext,
870 			      struct smc_clc_v2_extension, fixed);
871 	smcd_v2_ext = container_of(&pclc->pclc_smcd_v2_ext,
872 				   struct smc_clc_smcd_v2_extension, fixed);
873 	gidchids = pclc->pclc_gidchids;
874 	trl = &pclc->pclc_trl;
875 
876 	pclc_base->hdr.version = SMC_V2;
877 	pclc_base->hdr.typev1 = ini->smc_type_v1;
878 	pclc_base->hdr.typev2 = ini->smc_type_v2;
879 	plen = sizeof(*pclc_base) + sizeof(*pclc_smcd) + sizeof(*trl);
880 
881 	/* retrieve ip prefixes for CLC proposal msg */
882 	if (ini->smc_type_v1 != SMC_TYPE_N) {
883 		rc = smc_clc_prfx_set(smc->clcsock, pclc_prfx, ipv6_prfx);
884 		if (rc) {
885 			if (ini->smc_type_v2 == SMC_TYPE_N) {
886 				kfree(pclc);
887 				return SMC_CLC_DECL_CNFERR;
888 			}
889 			pclc_base->hdr.typev1 = SMC_TYPE_N;
890 		} else {
891 			pclc_base->iparea_offset = htons(sizeof(*pclc_smcd));
892 			plen += sizeof(*pclc_prfx) +
893 					pclc_prfx->ipv6_prefixes_cnt *
894 					sizeof(ipv6_prfx[0]);
895 		}
896 	}
897 
898 	/* build SMC Proposal CLC message */
899 	memcpy(pclc_base->hdr.eyecatcher, SMC_EYECATCHER,
900 	       sizeof(SMC_EYECATCHER));
901 	pclc_base->hdr.type = SMC_CLC_PROPOSAL;
902 	if (smcr_indicated(ini->smc_type_v1)) {
903 		/* add SMC-R specifics */
904 		memcpy(pclc_base->lcl.id_for_peer, local_systemid,
905 		       sizeof(local_systemid));
906 		memcpy(pclc_base->lcl.gid, ini->ib_gid, SMC_GID_SIZE);
907 		memcpy(pclc_base->lcl.mac, &ini->ib_dev->mac[ini->ib_port - 1],
908 		       ETH_ALEN);
909 	}
910 	if (smcd_indicated(ini->smc_type_v1)) {
911 		struct smcd_gid smcd_gid;
912 
913 		/* add SMC-D specifics */
914 		if (ini->ism_dev[0]) {
915 			smcd = ini->ism_dev[0];
916 			smcd->ops->get_local_gid(smcd, &smcd_gid);
917 			pclc_smcd->ism.gid = htonll(smcd_gid.gid);
918 			pclc_smcd->ism.chid =
919 				htons(smc_ism_get_chid(ini->ism_dev[0]));
920 		}
921 	}
922 	if (ini->smc_type_v2 == SMC_TYPE_N) {
923 		pclc_smcd->v2_ext_offset = 0;
924 	} else {
925 		struct smc_clc_eid_entry *ueident;
926 		u16 v2_ext_offset;
927 
928 		v2_ext->hdr.flag.release = SMC_RELEASE;
929 		v2_ext_offset = sizeof(*pclc_smcd) -
930 			offsetofend(struct smc_clc_msg_smcd, v2_ext_offset);
931 		if (ini->smc_type_v1 != SMC_TYPE_N)
932 			v2_ext_offset += sizeof(*pclc_prfx) +
933 						pclc_prfx->ipv6_prefixes_cnt *
934 						sizeof(ipv6_prfx[0]);
935 		pclc_smcd->v2_ext_offset = htons(v2_ext_offset);
936 		plen += sizeof(*v2_ext);
937 
938 		v2_ext->feature_mask = htons(SMC_FEATURE_MASK);
939 		read_lock(&smc_clc_eid_table.lock);
940 		v2_ext->hdr.eid_cnt = smc_clc_eid_table.ueid_cnt;
941 		plen += smc_clc_eid_table.ueid_cnt * SMC_MAX_EID_LEN;
942 		i = 0;
943 		list_for_each_entry(ueident, &smc_clc_eid_table.list, list) {
944 			memcpy(v2_ext->user_eids[i++], ueident->eid,
945 			       sizeof(ueident->eid));
946 		}
947 		read_unlock(&smc_clc_eid_table.lock);
948 	}
949 	if (smcd_indicated(ini->smc_type_v2)) {
950 		struct smcd_gid smcd_gid;
951 		u8 *eid = NULL;
952 		int entry = 0;
953 
954 		v2_ext->hdr.flag.seid = smc_clc_eid_table.seid_enabled;
955 		v2_ext->hdr.smcd_v2_ext_offset = htons(sizeof(*v2_ext) -
956 				offsetofend(struct smc_clnt_opts_area_hdr,
957 					    smcd_v2_ext_offset) +
958 				v2_ext->hdr.eid_cnt * SMC_MAX_EID_LEN);
959 		smc_ism_get_system_eid(&eid);
960 		if (eid && v2_ext->hdr.flag.seid)
961 			memcpy(smcd_v2_ext->system_eid, eid, SMC_MAX_EID_LEN);
962 		plen += sizeof(*smcd_v2_ext);
963 		if (ini->ism_offered_cnt) {
964 			for (i = 1; i <= ini->ism_offered_cnt; i++) {
965 				smcd = ini->ism_dev[i];
966 				smcd->ops->get_local_gid(smcd, &smcd_gid);
967 				gidchids[entry].chid =
968 					htons(smc_ism_get_chid(ini->ism_dev[i]));
969 				gidchids[entry].gid = htonll(smcd_gid.gid);
970 				if (smc_ism_is_emulated(smcd)) {
971 					/* an Emulated-ISM device takes two
972 					 * entries. CHID of the second entry
973 					 * repeats that of the first entry.
974 					 */
975 					gidchids[entry + 1].chid =
976 						gidchids[entry].chid;
977 					gidchids[entry + 1].gid =
978 						htonll(smcd_gid.gid_ext);
979 					entry++;
980 				}
981 				entry++;
982 			}
983 			plen += entry * sizeof(struct smc_clc_smcd_gid_chid);
984 		}
985 		v2_ext->hdr.ism_gid_cnt = entry;
986 	}
987 	if (smcr_indicated(ini->smc_type_v2)) {
988 		memcpy(v2_ext->roce, ini->smcrv2.ib_gid_v2, SMC_GID_SIZE);
989 		v2_ext->max_conns = net->smc.sysctl_max_conns_per_lgr;
990 		v2_ext->max_links = net->smc.sysctl_max_links_per_lgr;
991 	}
992 
993 	pclc_base->hdr.length = htons(plen);
994 	memcpy(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
995 
996 	/* send SMC Proposal CLC message */
997 	memset(&msg, 0, sizeof(msg));
998 	i = 0;
999 	vec[i].iov_base = pclc_base;
1000 	vec[i++].iov_len = sizeof(*pclc_base);
1001 	vec[i].iov_base = pclc_smcd;
1002 	vec[i++].iov_len = sizeof(*pclc_smcd);
1003 	if (ini->smc_type_v1 != SMC_TYPE_N) {
1004 		vec[i].iov_base = pclc_prfx;
1005 		vec[i++].iov_len = sizeof(*pclc_prfx);
1006 		if (pclc_prfx->ipv6_prefixes_cnt > 0) {
1007 			vec[i].iov_base = ipv6_prfx;
1008 			vec[i++].iov_len = pclc_prfx->ipv6_prefixes_cnt *
1009 					   sizeof(ipv6_prfx[0]);
1010 		}
1011 	}
1012 	if (ini->smc_type_v2 != SMC_TYPE_N) {
1013 		vec[i].iov_base = v2_ext;
1014 		vec[i++].iov_len = sizeof(*v2_ext) +
1015 				   (v2_ext->hdr.eid_cnt * SMC_MAX_EID_LEN);
1016 		if (smcd_indicated(ini->smc_type_v2)) {
1017 			vec[i].iov_base = smcd_v2_ext;
1018 			vec[i++].iov_len = sizeof(*smcd_v2_ext);
1019 			if (ini->ism_offered_cnt) {
1020 				vec[i].iov_base = gidchids;
1021 				vec[i++].iov_len = v2_ext->hdr.ism_gid_cnt *
1022 					sizeof(struct smc_clc_smcd_gid_chid);
1023 			}
1024 		}
1025 	}
1026 	vec[i].iov_base = trl;
1027 	vec[i++].iov_len = sizeof(*trl);
1028 	/* due to the few bytes needed for clc-handshake this cannot block */
1029 	len = kernel_sendmsg(smc->clcsock, &msg, vec, i, plen);
1030 	if (len < 0) {
1031 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
1032 		reason_code = -smc->sk.sk_err;
1033 	} else if (len < ntohs(pclc_base->hdr.length)) {
1034 		reason_code = -ENETUNREACH;
1035 		smc->sk.sk_err = -reason_code;
1036 	}
1037 
1038 	kfree(pclc);
1039 	return reason_code;
1040 }
1041 
1042 static void
1043 smcd_clc_prep_confirm_accept(struct smc_connection *conn,
1044 			     struct smc_clc_msg_accept_confirm *clc,
1045 			     int first_contact, u8 version,
1046 			     u8 *eid, struct smc_init_info *ini,
1047 			     int *fce_len,
1048 			     struct smc_clc_first_contact_ext_v2x *fce_v2x,
1049 			     struct smc_clc_msg_trail *trl)
1050 {
1051 	struct smcd_dev *smcd = conn->lgr->smcd;
1052 	struct smcd_gid smcd_gid;
1053 	u16 chid;
1054 	int len;
1055 
1056 	/* SMC-D specific settings */
1057 	memcpy(clc->hdr.eyecatcher, SMCD_EYECATCHER,
1058 	       sizeof(SMCD_EYECATCHER));
1059 	smcd->ops->get_local_gid(smcd, &smcd_gid);
1060 	clc->hdr.typev1 = SMC_TYPE_D;
1061 	clc->d0.gid = htonll(smcd_gid.gid);
1062 	clc->d0.token = htonll(conn->rmb_desc->token);
1063 	clc->d0.dmbe_size = conn->rmbe_size_comp;
1064 	clc->d0.dmbe_idx = 0;
1065 	memcpy(&clc->d0.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
1066 	if (version == SMC_V1) {
1067 		clc->hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
1068 	} else {
1069 		chid = smc_ism_get_chid(smcd);
1070 		clc->d1.chid = htons(chid);
1071 		if (eid && eid[0])
1072 			memcpy(clc->d1.eid, eid, SMC_MAX_EID_LEN);
1073 		if (__smc_ism_is_emulated(chid))
1074 			clc->d1.gid_ext = htonll(smcd_gid.gid_ext);
1075 		len = SMCD_CLC_ACCEPT_CONFIRM_LEN_V2;
1076 		if (first_contact) {
1077 			*fce_len = smc_clc_fill_fce_v2x(fce_v2x, ini);
1078 			len += *fce_len;
1079 		}
1080 		clc->hdr.length = htons(len);
1081 	}
1082 	memcpy(trl->eyecatcher, SMCD_EYECATCHER,
1083 	       sizeof(SMCD_EYECATCHER));
1084 }
1085 
1086 static void
1087 smcr_clc_prep_confirm_accept(struct smc_connection *conn,
1088 			     struct smc_clc_msg_accept_confirm *clc,
1089 			     int first_contact, u8 version,
1090 			     u8 *eid, struct smc_init_info *ini,
1091 			     int *fce_len,
1092 			     struct smc_clc_first_contact_ext_v2x *fce_v2x,
1093 			     struct smc_clc_fce_gid_ext *gle,
1094 			     struct smc_clc_msg_trail *trl)
1095 {
1096 	struct smc_link *link = conn->lnk;
1097 	int len;
1098 
1099 	/* SMC-R specific settings */
1100 	memcpy(clc->hdr.eyecatcher, SMC_EYECATCHER,
1101 	       sizeof(SMC_EYECATCHER));
1102 	clc->hdr.typev1 = SMC_TYPE_R;
1103 	memcpy(clc->r0.lcl.id_for_peer, local_systemid,
1104 	       sizeof(local_systemid));
1105 	memcpy(&clc->r0.lcl.gid, link->gid, SMC_GID_SIZE);
1106 	memcpy(&clc->r0.lcl.mac, &link->smcibdev->mac[link->ibport - 1],
1107 	       ETH_ALEN);
1108 	hton24(clc->r0.qpn, link->roce_qp->qp_num);
1109 	clc->r0.rmb_rkey =
1110 		htonl(conn->rmb_desc->mr[link->link_idx]->rkey);
1111 	clc->r0.rmbe_idx = 1; /* for now: 1 RMB = 1 RMBE */
1112 	clc->r0.rmbe_alert_token = htonl(conn->alert_token_local);
1113 	switch (clc->hdr.type) {
1114 	case SMC_CLC_ACCEPT:
1115 		clc->r0.qp_mtu = link->path_mtu;
1116 		break;
1117 	case SMC_CLC_CONFIRM:
1118 		clc->r0.qp_mtu = min(link->path_mtu, link->peer_mtu);
1119 		break;
1120 	}
1121 	clc->r0.rmbe_size = conn->rmbe_size_comp;
1122 	clc->r0.rmb_dma_addr = conn->rmb_desc->is_vm ?
1123 		cpu_to_be64((uintptr_t)conn->rmb_desc->cpu_addr) :
1124 		cpu_to_be64((u64)sg_dma_address
1125 			    (conn->rmb_desc->sgt[link->link_idx].sgl));
1126 	hton24(clc->r0.psn, link->psn_initial);
1127 	if (version == SMC_V1) {
1128 		clc->hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
1129 	} else {
1130 		if (eid && eid[0])
1131 			memcpy(clc->r1.eid, eid, SMC_MAX_EID_LEN);
1132 		len = SMCR_CLC_ACCEPT_CONFIRM_LEN_V2;
1133 		if (first_contact) {
1134 			*fce_len = smc_clc_fill_fce_v2x(fce_v2x, ini);
1135 			len += *fce_len;
1136 			fce_v2x->fce_v2_base.v2_direct =
1137 				!link->lgr->uses_gateway;
1138 			if (clc->hdr.type == SMC_CLC_CONFIRM) {
1139 				memset(gle, 0, sizeof(*gle));
1140 				gle->gid_cnt = ini->smcrv2.gidlist.len;
1141 				len += sizeof(*gle);
1142 				len += gle->gid_cnt * sizeof(gle->gid[0]);
1143 			}
1144 		}
1145 		clc->hdr.length = htons(len);
1146 	}
1147 	memcpy(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
1148 }
1149 
1150 /* build and send CLC CONFIRM / ACCEPT message */
1151 static int smc_clc_send_confirm_accept(struct smc_sock *smc,
1152 				       struct smc_clc_msg_accept_confirm *clc,
1153 				       int first_contact, u8 version,
1154 				       u8 *eid, struct smc_init_info *ini)
1155 {
1156 	struct smc_clc_first_contact_ext_v2x fce_v2x;
1157 	struct smc_connection *conn = &smc->conn;
1158 	struct smc_clc_fce_gid_ext gle;
1159 	struct smc_clc_msg_trail trl;
1160 	int i, fce_len;
1161 	struct kvec vec[5];
1162 	struct msghdr msg;
1163 
1164 	/* send SMC Confirm CLC msg */
1165 	clc->hdr.version = version;	/* SMC version */
1166 	if (first_contact)
1167 		clc->hdr.typev2 |= SMC_FIRST_CONTACT_MASK;
1168 	if (conn->lgr->is_smcd)
1169 		smcd_clc_prep_confirm_accept(conn, clc, first_contact,
1170 					     version, eid, ini, &fce_len,
1171 					     &fce_v2x, &trl);
1172 	else
1173 		smcr_clc_prep_confirm_accept(conn, clc, first_contact,
1174 					     version, eid, ini, &fce_len,
1175 					     &fce_v2x, &gle, &trl);
1176 	memset(&msg, 0, sizeof(msg));
1177 	i = 0;
1178 	vec[i].iov_base = clc;
1179 	if (version > SMC_V1)
1180 		vec[i++].iov_len = (clc->hdr.typev1 == SMC_TYPE_D ?
1181 					SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 :
1182 					SMCR_CLC_ACCEPT_CONFIRM_LEN_V2) -
1183 				   sizeof(trl);
1184 	else
1185 		vec[i++].iov_len = (clc->hdr.typev1 == SMC_TYPE_D ?
1186 						SMCD_CLC_ACCEPT_CONFIRM_LEN :
1187 						SMCR_CLC_ACCEPT_CONFIRM_LEN) -
1188 				   sizeof(trl);
1189 	if (version > SMC_V1 && first_contact) {
1190 		vec[i].iov_base = &fce_v2x;
1191 		vec[i++].iov_len = fce_len;
1192 		if (!conn->lgr->is_smcd) {
1193 			if (clc->hdr.type == SMC_CLC_CONFIRM) {
1194 				vec[i].iov_base = &gle;
1195 				vec[i++].iov_len = sizeof(gle);
1196 				vec[i].iov_base = &ini->smcrv2.gidlist.list;
1197 				vec[i++].iov_len = gle.gid_cnt *
1198 						   sizeof(gle.gid[0]);
1199 			}
1200 		}
1201 	}
1202 	vec[i].iov_base = &trl;
1203 	vec[i++].iov_len = sizeof(trl);
1204 	return kernel_sendmsg(smc->clcsock, &msg, vec, 1,
1205 			      ntohs(clc->hdr.length));
1206 }
1207 
1208 /* send CLC CONFIRM message across internal TCP socket */
1209 int smc_clc_send_confirm(struct smc_sock *smc, bool clnt_first_contact,
1210 			 u8 version, u8 *eid, struct smc_init_info *ini)
1211 {
1212 	struct smc_clc_msg_accept_confirm cclc;
1213 	int reason_code = 0;
1214 	int len;
1215 
1216 	/* send SMC Confirm CLC msg */
1217 	memset(&cclc, 0, sizeof(cclc));
1218 	cclc.hdr.type = SMC_CLC_CONFIRM;
1219 	len = smc_clc_send_confirm_accept(smc, &cclc, clnt_first_contact,
1220 					  version, eid, ini);
1221 	if (len < ntohs(cclc.hdr.length)) {
1222 		if (len >= 0) {
1223 			reason_code = -ENETUNREACH;
1224 			smc->sk.sk_err = -reason_code;
1225 		} else {
1226 			smc->sk.sk_err = smc->clcsock->sk->sk_err;
1227 			reason_code = -smc->sk.sk_err;
1228 		}
1229 	}
1230 	return reason_code;
1231 }
1232 
1233 /* send CLC ACCEPT message across internal TCP socket */
1234 int smc_clc_send_accept(struct smc_sock *new_smc, bool srv_first_contact,
1235 			u8 version, u8 *negotiated_eid, struct smc_init_info *ini)
1236 {
1237 	struct smc_clc_msg_accept_confirm aclc;
1238 	int len;
1239 
1240 	memset(&aclc, 0, sizeof(aclc));
1241 	aclc.hdr.type = SMC_CLC_ACCEPT;
1242 	len = smc_clc_send_confirm_accept(new_smc, &aclc, srv_first_contact,
1243 					  version, negotiated_eid, ini);
1244 	if (len < ntohs(aclc.hdr.length))
1245 		len = len >= 0 ? -EPROTO : -new_smc->clcsock->sk->sk_err;
1246 
1247 	return len > 0 ? 0 : len;
1248 }
1249 
1250 int smc_clc_srv_v2x_features_validate(struct smc_sock *smc,
1251 				      struct smc_clc_msg_proposal *pclc,
1252 				      struct smc_init_info *ini)
1253 {
1254 	struct smc_clc_v2_extension *pclc_v2_ext;
1255 	struct net *net = sock_net(&smc->sk);
1256 
1257 	ini->max_conns = SMC_CONN_PER_LGR_MAX;
1258 	ini->max_links = SMC_LINKS_ADD_LNK_MAX;
1259 	ini->feature_mask = SMC_FEATURE_MASK;
1260 
1261 	if ((!(ini->smcd_version & SMC_V2) && !(ini->smcr_version & SMC_V2)) ||
1262 	    ini->release_nr < SMC_RELEASE_1)
1263 		return 0;
1264 
1265 	pclc_v2_ext = smc_get_clc_v2_ext(pclc);
1266 	if (!pclc_v2_ext)
1267 		return SMC_CLC_DECL_NOV2EXT;
1268 
1269 	if (ini->smcr_version & SMC_V2) {
1270 		ini->max_conns = min_t(u8, pclc_v2_ext->max_conns,
1271 				       net->smc.sysctl_max_conns_per_lgr);
1272 		if (ini->max_conns < SMC_CONN_PER_LGR_MIN)
1273 			return SMC_CLC_DECL_MAXCONNERR;
1274 
1275 		ini->max_links = min_t(u8, pclc_v2_ext->max_links,
1276 				       net->smc.sysctl_max_links_per_lgr);
1277 		if (ini->max_links < SMC_LINKS_ADD_LNK_MIN)
1278 			return SMC_CLC_DECL_MAXLINKERR;
1279 	}
1280 
1281 	return 0;
1282 }
1283 
1284 int smc_clc_clnt_v2x_features_validate(struct smc_clc_first_contact_ext *fce,
1285 				       struct smc_init_info *ini)
1286 {
1287 	struct smc_clc_first_contact_ext_v2x *fce_v2x =
1288 		(struct smc_clc_first_contact_ext_v2x *)fce;
1289 
1290 	if (ini->release_nr < SMC_RELEASE_1)
1291 		return 0;
1292 
1293 	if (!ini->is_smcd) {
1294 		if (fce_v2x->max_conns < SMC_CONN_PER_LGR_MIN)
1295 			return SMC_CLC_DECL_MAXCONNERR;
1296 		ini->max_conns = fce_v2x->max_conns;
1297 
1298 		if (fce_v2x->max_links > SMC_LINKS_ADD_LNK_MAX ||
1299 		    fce_v2x->max_links < SMC_LINKS_ADD_LNK_MIN)
1300 			return SMC_CLC_DECL_MAXLINKERR;
1301 		ini->max_links = fce_v2x->max_links;
1302 	}
1303 	/* common supplemental features of server and client */
1304 	ini->feature_mask = ntohs(fce_v2x->feature_mask) & SMC_FEATURE_MASK;
1305 
1306 	return 0;
1307 }
1308 
1309 int smc_clc_v2x_features_confirm_check(struct smc_clc_msg_accept_confirm *cclc,
1310 				       struct smc_init_info *ini)
1311 {
1312 	struct smc_clc_first_contact_ext *fce =
1313 		smc_get_clc_first_contact_ext(cclc, ini->is_smcd);
1314 	struct smc_clc_first_contact_ext_v2x *fce_v2x =
1315 		(struct smc_clc_first_contact_ext_v2x *)fce;
1316 
1317 	if (cclc->hdr.version == SMC_V1 ||
1318 	    !(cclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
1319 		return 0;
1320 
1321 	if (ini->release_nr != fce->release)
1322 		return SMC_CLC_DECL_RELEASEERR;
1323 
1324 	if (fce->release < SMC_RELEASE_1)
1325 		return 0;
1326 
1327 	if (!ini->is_smcd) {
1328 		if (fce_v2x->max_conns != ini->max_conns)
1329 			return SMC_CLC_DECL_MAXCONNERR;
1330 		if (fce_v2x->max_links != ini->max_links)
1331 			return SMC_CLC_DECL_MAXLINKERR;
1332 	}
1333 	/* common supplemental features returned by client */
1334 	ini->feature_mask = ntohs(fce_v2x->feature_mask);
1335 
1336 	return 0;
1337 }
1338 
1339 void smc_clc_get_hostname(u8 **host)
1340 {
1341 	*host = &smc_hostname[0];
1342 }
1343 
1344 void __init smc_clc_init(void)
1345 {
1346 	struct new_utsname *u;
1347 
1348 	memset(smc_hostname, _S, sizeof(smc_hostname)); /* ASCII blanks */
1349 	u = utsname();
1350 	memcpy(smc_hostname, u->nodename,
1351 	       min_t(size_t, strlen(u->nodename), sizeof(smc_hostname)));
1352 
1353 	INIT_LIST_HEAD(&smc_clc_eid_table.list);
1354 	rwlock_init(&smc_clc_eid_table.lock);
1355 	smc_clc_eid_table.ueid_cnt = 0;
1356 #if IS_ENABLED(CONFIG_S390)
1357 	smc_clc_eid_table.seid_enabled = 1;
1358 #else
1359 	smc_clc_eid_table.seid_enabled = 0;
1360 #endif
1361 }
1362 
1363 void smc_clc_exit(void)
1364 {
1365 	smc_clc_ueid_remove(NULL);
1366 }
1367