xref: /linux/net/smc/af_smc.c (revision 43b46e6bc69c2aa4331cfd7fa4e2943a894339e5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
4  *
5  *  AF_SMC protocol family socket handler keeping the AF_INET sock address type
6  *  applies to SOCK_STREAM sockets only
7  *  offers an alternative communication option for TCP-protocol sockets
8  *  applicable with RoCE-cards only
9  *
10  *  Initial restrictions:
11  *    - support for alternate links postponed
12  *
13  *  Copyright IBM Corp. 2016, 2018
14  *
15  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
16  *              based on prototype from Frank Blaschka
17  */
18 
19 #define KMSG_COMPONENT "smc"
20 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
21 
22 #include <linux/module.h>
23 #include <linux/socket.h>
24 #include <linux/workqueue.h>
25 #include <linux/in.h>
26 #include <linux/sched/signal.h>
27 #include <linux/if_vlan.h>
28 #include <linux/rcupdate_wait.h>
29 #include <linux/ctype.h>
30 
31 #include <net/sock.h>
32 #include <net/tcp.h>
33 #include <net/smc.h>
34 #include <asm/ioctls.h>
35 
36 #include <net/net_namespace.h>
37 #include <net/netns/generic.h>
38 #include "smc_netns.h"
39 
40 #include "smc.h"
41 #include "smc_clc.h"
42 #include "smc_llc.h"
43 #include "smc_cdc.h"
44 #include "smc_core.h"
45 #include "smc_ib.h"
46 #include "smc_ism.h"
47 #include "smc_pnet.h"
48 #include "smc_netlink.h"
49 #include "smc_tx.h"
50 #include "smc_rx.h"
51 #include "smc_close.h"
52 #include "smc_stats.h"
53 #include "smc_tracepoint.h"
54 #include "smc_sysctl.h"
55 
56 static DEFINE_MUTEX(smc_server_lgr_pending);	/* serialize link group
57 						 * creation on server
58 						 */
59 static DEFINE_MUTEX(smc_client_lgr_pending);	/* serialize link group
60 						 * creation on client
61 						 */
62 
63 static struct workqueue_struct	*smc_tcp_ls_wq;	/* wq for tcp listen work */
64 struct workqueue_struct	*smc_hs_wq;	/* wq for handshake work */
65 struct workqueue_struct	*smc_close_wq;	/* wq for close work */
66 
67 static void smc_tcp_listen_work(struct work_struct *);
68 static void smc_connect_work(struct work_struct *);
69 
70 int smc_nl_dump_hs_limitation(struct sk_buff *skb, struct netlink_callback *cb)
71 {
72 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
73 	void *hdr;
74 
75 	if (cb_ctx->pos[0])
76 		goto out;
77 
78 	hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
79 			  &smc_gen_nl_family, NLM_F_MULTI,
80 			  SMC_NETLINK_DUMP_HS_LIMITATION);
81 	if (!hdr)
82 		return -ENOMEM;
83 
84 	if (nla_put_u8(skb, SMC_NLA_HS_LIMITATION_ENABLED,
85 		       sock_net(skb->sk)->smc.limit_smc_hs))
86 		goto err;
87 
88 	genlmsg_end(skb, hdr);
89 	cb_ctx->pos[0] = 1;
90 out:
91 	return skb->len;
92 err:
93 	genlmsg_cancel(skb, hdr);
94 	return -EMSGSIZE;
95 }
96 
97 int smc_nl_enable_hs_limitation(struct sk_buff *skb, struct genl_info *info)
98 {
99 	sock_net(skb->sk)->smc.limit_smc_hs = true;
100 	return 0;
101 }
102 
103 int smc_nl_disable_hs_limitation(struct sk_buff *skb, struct genl_info *info)
104 {
105 	sock_net(skb->sk)->smc.limit_smc_hs = false;
106 	return 0;
107 }
108 
109 static void smc_set_keepalive(struct sock *sk, int val)
110 {
111 	struct smc_sock *smc = smc_sk(sk);
112 
113 	smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
114 }
115 
116 static struct sock *smc_tcp_syn_recv_sock(const struct sock *sk,
117 					  struct sk_buff *skb,
118 					  struct request_sock *req,
119 					  struct dst_entry *dst,
120 					  struct request_sock *req_unhash,
121 					  bool *own_req)
122 {
123 	struct smc_sock *smc;
124 	struct sock *child;
125 
126 	smc = smc_clcsock_user_data(sk);
127 
128 	if (READ_ONCE(sk->sk_ack_backlog) + atomic_read(&smc->queued_smc_hs) >
129 				sk->sk_max_ack_backlog)
130 		goto drop;
131 
132 	if (sk_acceptq_is_full(&smc->sk)) {
133 		NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
134 		goto drop;
135 	}
136 
137 	/* passthrough to original syn recv sock fct */
138 	child = smc->ori_af_ops->syn_recv_sock(sk, skb, req, dst, req_unhash,
139 					       own_req);
140 	/* child must not inherit smc or its ops */
141 	if (child) {
142 		rcu_assign_sk_user_data(child, NULL);
143 
144 		/* v4-mapped sockets don't inherit parent ops. Don't restore. */
145 		if (inet_csk(child)->icsk_af_ops == inet_csk(sk)->icsk_af_ops)
146 			inet_csk(child)->icsk_af_ops = smc->ori_af_ops;
147 	}
148 	return child;
149 
150 drop:
151 	dst_release(dst);
152 	tcp_listendrop(sk);
153 	return NULL;
154 }
155 
156 static bool smc_hs_congested(const struct sock *sk)
157 {
158 	const struct smc_sock *smc;
159 
160 	smc = smc_clcsock_user_data(sk);
161 
162 	if (!smc)
163 		return true;
164 
165 	if (workqueue_congested(WORK_CPU_UNBOUND, smc_hs_wq))
166 		return true;
167 
168 	return false;
169 }
170 
171 static struct smc_hashinfo smc_v4_hashinfo = {
172 	.lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
173 };
174 
175 static struct smc_hashinfo smc_v6_hashinfo = {
176 	.lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
177 };
178 
179 int smc_hash_sk(struct sock *sk)
180 {
181 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
182 	struct hlist_head *head;
183 
184 	head = &h->ht;
185 
186 	write_lock_bh(&h->lock);
187 	sk_add_node(sk, head);
188 	write_unlock_bh(&h->lock);
189 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
190 
191 	return 0;
192 }
193 EXPORT_SYMBOL_GPL(smc_hash_sk);
194 
195 void smc_unhash_sk(struct sock *sk)
196 {
197 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
198 
199 	write_lock_bh(&h->lock);
200 	if (sk_del_node_init(sk))
201 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
202 	write_unlock_bh(&h->lock);
203 }
204 EXPORT_SYMBOL_GPL(smc_unhash_sk);
205 
206 /* This will be called before user really release sock_lock. So do the
207  * work which we didn't do because of user hold the sock_lock in the
208  * BH context
209  */
210 static void smc_release_cb(struct sock *sk)
211 {
212 	struct smc_sock *smc = smc_sk(sk);
213 
214 	if (smc->conn.tx_in_release_sock) {
215 		smc_tx_pending(&smc->conn);
216 		smc->conn.tx_in_release_sock = false;
217 	}
218 }
219 
220 struct proto smc_proto = {
221 	.name		= "SMC",
222 	.owner		= THIS_MODULE,
223 	.keepalive	= smc_set_keepalive,
224 	.hash		= smc_hash_sk,
225 	.unhash		= smc_unhash_sk,
226 	.release_cb	= smc_release_cb,
227 	.obj_size	= sizeof(struct smc_sock),
228 	.h.smc_hash	= &smc_v4_hashinfo,
229 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
230 };
231 EXPORT_SYMBOL_GPL(smc_proto);
232 
233 struct proto smc_proto6 = {
234 	.name		= "SMC6",
235 	.owner		= THIS_MODULE,
236 	.keepalive	= smc_set_keepalive,
237 	.hash		= smc_hash_sk,
238 	.unhash		= smc_unhash_sk,
239 	.release_cb	= smc_release_cb,
240 	.obj_size	= sizeof(struct smc_sock),
241 	.h.smc_hash	= &smc_v6_hashinfo,
242 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
243 };
244 EXPORT_SYMBOL_GPL(smc_proto6);
245 
246 static void smc_fback_restore_callbacks(struct smc_sock *smc)
247 {
248 	struct sock *clcsk = smc->clcsock->sk;
249 
250 	write_lock_bh(&clcsk->sk_callback_lock);
251 	clcsk->sk_user_data = NULL;
252 
253 	smc_clcsock_restore_cb(&clcsk->sk_state_change, &smc->clcsk_state_change);
254 	smc_clcsock_restore_cb(&clcsk->sk_data_ready, &smc->clcsk_data_ready);
255 	smc_clcsock_restore_cb(&clcsk->sk_write_space, &smc->clcsk_write_space);
256 	smc_clcsock_restore_cb(&clcsk->sk_error_report, &smc->clcsk_error_report);
257 
258 	write_unlock_bh(&clcsk->sk_callback_lock);
259 }
260 
261 static void smc_restore_fallback_changes(struct smc_sock *smc)
262 {
263 	if (smc->clcsock->file) { /* non-accepted sockets have no file yet */
264 		smc->clcsock->file->private_data = smc->sk.sk_socket;
265 		smc->clcsock->file = NULL;
266 		smc_fback_restore_callbacks(smc);
267 	}
268 }
269 
270 static int __smc_release(struct smc_sock *smc)
271 {
272 	struct sock *sk = &smc->sk;
273 	int rc = 0;
274 
275 	if (!smc->use_fallback) {
276 		rc = smc_close_active(smc);
277 		sock_set_flag(sk, SOCK_DEAD);
278 		sk->sk_shutdown |= SHUTDOWN_MASK;
279 	} else {
280 		if (sk->sk_state != SMC_CLOSED) {
281 			if (sk->sk_state != SMC_LISTEN &&
282 			    sk->sk_state != SMC_INIT)
283 				sock_put(sk); /* passive closing */
284 			if (sk->sk_state == SMC_LISTEN) {
285 				/* wake up clcsock accept */
286 				rc = kernel_sock_shutdown(smc->clcsock,
287 							  SHUT_RDWR);
288 			}
289 			sk->sk_state = SMC_CLOSED;
290 			sk->sk_state_change(sk);
291 		}
292 		smc_restore_fallback_changes(smc);
293 	}
294 
295 	sk->sk_prot->unhash(sk);
296 
297 	if (sk->sk_state == SMC_CLOSED) {
298 		if (smc->clcsock) {
299 			release_sock(sk);
300 			smc_clcsock_release(smc);
301 			lock_sock(sk);
302 		}
303 		if (!smc->use_fallback)
304 			smc_conn_free(&smc->conn);
305 	}
306 
307 	return rc;
308 }
309 
310 static int smc_release(struct socket *sock)
311 {
312 	struct sock *sk = sock->sk;
313 	struct smc_sock *smc;
314 	int old_state, rc = 0;
315 
316 	if (!sk)
317 		goto out;
318 
319 	sock_hold(sk); /* sock_put below */
320 	smc = smc_sk(sk);
321 
322 	old_state = sk->sk_state;
323 
324 	/* cleanup for a dangling non-blocking connect */
325 	if (smc->connect_nonblock && old_state == SMC_INIT)
326 		tcp_abort(smc->clcsock->sk, ECONNABORTED);
327 
328 	if (cancel_work_sync(&smc->connect_work))
329 		sock_put(&smc->sk); /* sock_hold in smc_connect for passive closing */
330 
331 	if (sk->sk_state == SMC_LISTEN)
332 		/* smc_close_non_accepted() is called and acquires
333 		 * sock lock for child sockets again
334 		 */
335 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
336 	else
337 		lock_sock(sk);
338 
339 	if (old_state == SMC_INIT && sk->sk_state == SMC_ACTIVE &&
340 	    !smc->use_fallback)
341 		smc_close_active_abort(smc);
342 
343 	rc = __smc_release(smc);
344 
345 	/* detach socket */
346 	sock_orphan(sk);
347 	sock->sk = NULL;
348 	release_sock(sk);
349 
350 	sock_put(sk); /* sock_hold above */
351 	sock_put(sk); /* final sock_put */
352 out:
353 	return rc;
354 }
355 
356 static void smc_destruct(struct sock *sk)
357 {
358 	if (sk->sk_state != SMC_CLOSED)
359 		return;
360 	if (!sock_flag(sk, SOCK_DEAD))
361 		return;
362 
363 	sk_refcnt_debug_dec(sk);
364 }
365 
366 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
367 				   int protocol)
368 {
369 	struct smc_sock *smc;
370 	struct proto *prot;
371 	struct sock *sk;
372 
373 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
374 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
375 	if (!sk)
376 		return NULL;
377 
378 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
379 	sk->sk_state = SMC_INIT;
380 	sk->sk_destruct = smc_destruct;
381 	sk->sk_protocol = protocol;
382 	WRITE_ONCE(sk->sk_sndbuf, READ_ONCE(net->smc.sysctl_wmem));
383 	WRITE_ONCE(sk->sk_rcvbuf, READ_ONCE(net->smc.sysctl_rmem));
384 	smc = smc_sk(sk);
385 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
386 	INIT_WORK(&smc->connect_work, smc_connect_work);
387 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
388 	INIT_LIST_HEAD(&smc->accept_q);
389 	spin_lock_init(&smc->accept_q_lock);
390 	spin_lock_init(&smc->conn.send_lock);
391 	sk->sk_prot->hash(sk);
392 	sk_refcnt_debug_inc(sk);
393 	mutex_init(&smc->clcsock_release_lock);
394 	smc_init_saved_callbacks(smc);
395 
396 	return sk;
397 }
398 
399 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
400 		    int addr_len)
401 {
402 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
403 	struct sock *sk = sock->sk;
404 	struct smc_sock *smc;
405 	int rc;
406 
407 	smc = smc_sk(sk);
408 
409 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
410 	rc = -EINVAL;
411 	if (addr_len < sizeof(struct sockaddr_in))
412 		goto out;
413 
414 	rc = -EAFNOSUPPORT;
415 	if (addr->sin_family != AF_INET &&
416 	    addr->sin_family != AF_INET6 &&
417 	    addr->sin_family != AF_UNSPEC)
418 		goto out;
419 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
420 	if (addr->sin_family == AF_UNSPEC &&
421 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
422 		goto out;
423 
424 	lock_sock(sk);
425 
426 	/* Check if socket is already active */
427 	rc = -EINVAL;
428 	if (sk->sk_state != SMC_INIT || smc->connect_nonblock)
429 		goto out_rel;
430 
431 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
432 	smc->clcsock->sk->sk_reuseport = sk->sk_reuseport;
433 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
434 
435 out_rel:
436 	release_sock(sk);
437 out:
438 	return rc;
439 }
440 
441 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
442 				   unsigned long mask)
443 {
444 	/* options we don't get control via setsockopt for */
445 	nsk->sk_type = osk->sk_type;
446 	nsk->sk_sndbuf = osk->sk_sndbuf;
447 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
448 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
449 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
450 	nsk->sk_mark = osk->sk_mark;
451 	nsk->sk_priority = osk->sk_priority;
452 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
453 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
454 	nsk->sk_err = osk->sk_err;
455 
456 	nsk->sk_flags &= ~mask;
457 	nsk->sk_flags |= osk->sk_flags & mask;
458 }
459 
460 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
461 			     (1UL << SOCK_KEEPOPEN) | \
462 			     (1UL << SOCK_LINGER) | \
463 			     (1UL << SOCK_BROADCAST) | \
464 			     (1UL << SOCK_TIMESTAMP) | \
465 			     (1UL << SOCK_DBG) | \
466 			     (1UL << SOCK_RCVTSTAMP) | \
467 			     (1UL << SOCK_RCVTSTAMPNS) | \
468 			     (1UL << SOCK_LOCALROUTE) | \
469 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
470 			     (1UL << SOCK_RXQ_OVFL) | \
471 			     (1UL << SOCK_WIFI_STATUS) | \
472 			     (1UL << SOCK_NOFCS) | \
473 			     (1UL << SOCK_FILTER_LOCKED) | \
474 			     (1UL << SOCK_TSTAMP_NEW))
475 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
476  * clc socket (since smc is not called for these options from net/core)
477  */
478 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
479 {
480 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
481 }
482 
483 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
484 			     (1UL << SOCK_KEEPOPEN) | \
485 			     (1UL << SOCK_LINGER) | \
486 			     (1UL << SOCK_DBG))
487 /* copy only settings and flags relevant for smc from clc to smc socket */
488 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
489 {
490 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
491 }
492 
493 /* register the new vzalloced sndbuf on all links */
494 static int smcr_lgr_reg_sndbufs(struct smc_link *link,
495 				struct smc_buf_desc *snd_desc)
496 {
497 	struct smc_link_group *lgr = link->lgr;
498 	int i, rc = 0;
499 
500 	if (!snd_desc->is_vm)
501 		return -EINVAL;
502 
503 	/* protect against parallel smcr_link_reg_buf() */
504 	mutex_lock(&lgr->llc_conf_mutex);
505 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
506 		if (!smc_link_active(&lgr->lnk[i]))
507 			continue;
508 		rc = smcr_link_reg_buf(&lgr->lnk[i], snd_desc);
509 		if (rc)
510 			break;
511 	}
512 	mutex_unlock(&lgr->llc_conf_mutex);
513 	return rc;
514 }
515 
516 /* register the new rmb on all links */
517 static int smcr_lgr_reg_rmbs(struct smc_link *link,
518 			     struct smc_buf_desc *rmb_desc)
519 {
520 	struct smc_link_group *lgr = link->lgr;
521 	int i, rc = 0;
522 
523 	rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
524 	if (rc)
525 		return rc;
526 	/* protect against parallel smc_llc_cli_rkey_exchange() and
527 	 * parallel smcr_link_reg_buf()
528 	 */
529 	mutex_lock(&lgr->llc_conf_mutex);
530 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
531 		if (!smc_link_active(&lgr->lnk[i]))
532 			continue;
533 		rc = smcr_link_reg_buf(&lgr->lnk[i], rmb_desc);
534 		if (rc)
535 			goto out;
536 	}
537 
538 	/* exchange confirm_rkey msg with peer */
539 	rc = smc_llc_do_confirm_rkey(link, rmb_desc);
540 	if (rc) {
541 		rc = -EFAULT;
542 		goto out;
543 	}
544 	rmb_desc->is_conf_rkey = true;
545 out:
546 	mutex_unlock(&lgr->llc_conf_mutex);
547 	smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
548 	return rc;
549 }
550 
551 static int smcr_clnt_conf_first_link(struct smc_sock *smc)
552 {
553 	struct smc_link *link = smc->conn.lnk;
554 	struct smc_llc_qentry *qentry;
555 	int rc;
556 
557 	/* receive CONFIRM LINK request from server over RoCE fabric */
558 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
559 			      SMC_LLC_CONFIRM_LINK);
560 	if (!qentry) {
561 		struct smc_clc_msg_decline dclc;
562 
563 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
564 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
565 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
566 	}
567 	smc_llc_save_peer_uid(qentry);
568 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_REQ);
569 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
570 	if (rc)
571 		return SMC_CLC_DECL_RMBE_EC;
572 
573 	rc = smc_ib_modify_qp_rts(link);
574 	if (rc)
575 		return SMC_CLC_DECL_ERR_RDYLNK;
576 
577 	smc_wr_remember_qp_attr(link);
578 
579 	/* reg the sndbuf if it was vzalloced */
580 	if (smc->conn.sndbuf_desc->is_vm) {
581 		if (smcr_link_reg_buf(link, smc->conn.sndbuf_desc))
582 			return SMC_CLC_DECL_ERR_REGBUF;
583 	}
584 
585 	/* reg the rmb */
586 	if (smcr_link_reg_buf(link, smc->conn.rmb_desc))
587 		return SMC_CLC_DECL_ERR_REGBUF;
588 
589 	/* confirm_rkey is implicit on 1st contact */
590 	smc->conn.rmb_desc->is_conf_rkey = true;
591 
592 	/* send CONFIRM LINK response over RoCE fabric */
593 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
594 	if (rc < 0)
595 		return SMC_CLC_DECL_TIMEOUT_CL;
596 
597 	smc_llc_link_active(link);
598 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
599 
600 	/* optional 2nd link, receive ADD LINK request from server */
601 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
602 			      SMC_LLC_ADD_LINK);
603 	if (!qentry) {
604 		struct smc_clc_msg_decline dclc;
605 
606 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
607 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
608 		if (rc == -EAGAIN)
609 			rc = 0; /* no DECLINE received, go with one link */
610 		return rc;
611 	}
612 	smc_llc_flow_qentry_clr(&link->lgr->llc_flow_lcl);
613 	smc_llc_cli_add_link(link, qentry);
614 	return 0;
615 }
616 
617 static bool smc_isascii(char *hostname)
618 {
619 	int i;
620 
621 	for (i = 0; i < SMC_MAX_HOSTNAME_LEN; i++)
622 		if (!isascii(hostname[i]))
623 			return false;
624 	return true;
625 }
626 
627 static void smc_conn_save_peer_info_fce(struct smc_sock *smc,
628 					struct smc_clc_msg_accept_confirm *clc)
629 {
630 	struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
631 		(struct smc_clc_msg_accept_confirm_v2 *)clc;
632 	struct smc_clc_first_contact_ext *fce;
633 	int clc_v2_len;
634 
635 	if (clc->hdr.version == SMC_V1 ||
636 	    !(clc->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
637 		return;
638 
639 	if (smc->conn.lgr->is_smcd) {
640 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->d1.eid,
641 		       SMC_MAX_EID_LEN);
642 		clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
643 					 d1);
644 	} else {
645 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->r1.eid,
646 		       SMC_MAX_EID_LEN);
647 		clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
648 					 r1);
649 	}
650 	fce = (struct smc_clc_first_contact_ext *)(((u8 *)clc_v2) + clc_v2_len);
651 	smc->conn.lgr->peer_os = fce->os_type;
652 	smc->conn.lgr->peer_smc_release = fce->release;
653 	if (smc_isascii(fce->hostname))
654 		memcpy(smc->conn.lgr->peer_hostname, fce->hostname,
655 		       SMC_MAX_HOSTNAME_LEN);
656 }
657 
658 static void smcr_conn_save_peer_info(struct smc_sock *smc,
659 				     struct smc_clc_msg_accept_confirm *clc)
660 {
661 	int bufsize = smc_uncompress_bufsize(clc->r0.rmbe_size);
662 
663 	smc->conn.peer_rmbe_idx = clc->r0.rmbe_idx;
664 	smc->conn.local_tx_ctrl.token = ntohl(clc->r0.rmbe_alert_token);
665 	smc->conn.peer_rmbe_size = bufsize;
666 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
667 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
668 }
669 
670 static void smcd_conn_save_peer_info(struct smc_sock *smc,
671 				     struct smc_clc_msg_accept_confirm *clc)
672 {
673 	int bufsize = smc_uncompress_bufsize(clc->d0.dmbe_size);
674 
675 	smc->conn.peer_rmbe_idx = clc->d0.dmbe_idx;
676 	smc->conn.peer_token = clc->d0.token;
677 	/* msg header takes up space in the buffer */
678 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
679 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
680 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
681 }
682 
683 static void smc_conn_save_peer_info(struct smc_sock *smc,
684 				    struct smc_clc_msg_accept_confirm *clc)
685 {
686 	if (smc->conn.lgr->is_smcd)
687 		smcd_conn_save_peer_info(smc, clc);
688 	else
689 		smcr_conn_save_peer_info(smc, clc);
690 	smc_conn_save_peer_info_fce(smc, clc);
691 }
692 
693 static void smc_link_save_peer_info(struct smc_link *link,
694 				    struct smc_clc_msg_accept_confirm *clc,
695 				    struct smc_init_info *ini)
696 {
697 	link->peer_qpn = ntoh24(clc->r0.qpn);
698 	memcpy(link->peer_gid, ini->peer_gid, SMC_GID_SIZE);
699 	memcpy(link->peer_mac, ini->peer_mac, sizeof(link->peer_mac));
700 	link->peer_psn = ntoh24(clc->r0.psn);
701 	link->peer_mtu = clc->r0.qp_mtu;
702 }
703 
704 static void smc_stat_inc_fback_rsn_cnt(struct smc_sock *smc,
705 				       struct smc_stats_fback *fback_arr)
706 {
707 	int cnt;
708 
709 	for (cnt = 0; cnt < SMC_MAX_FBACK_RSN_CNT; cnt++) {
710 		if (fback_arr[cnt].fback_code == smc->fallback_rsn) {
711 			fback_arr[cnt].count++;
712 			break;
713 		}
714 		if (!fback_arr[cnt].fback_code) {
715 			fback_arr[cnt].fback_code = smc->fallback_rsn;
716 			fback_arr[cnt].count++;
717 			break;
718 		}
719 	}
720 }
721 
722 static void smc_stat_fallback(struct smc_sock *smc)
723 {
724 	struct net *net = sock_net(&smc->sk);
725 
726 	mutex_lock(&net->smc.mutex_fback_rsn);
727 	if (smc->listen_smc) {
728 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->srv);
729 		net->smc.fback_rsn->srv_fback_cnt++;
730 	} else {
731 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->clnt);
732 		net->smc.fback_rsn->clnt_fback_cnt++;
733 	}
734 	mutex_unlock(&net->smc.mutex_fback_rsn);
735 }
736 
737 /* must be called under rcu read lock */
738 static void smc_fback_wakeup_waitqueue(struct smc_sock *smc, void *key)
739 {
740 	struct socket_wq *wq;
741 	__poll_t flags;
742 
743 	wq = rcu_dereference(smc->sk.sk_wq);
744 	if (!skwq_has_sleeper(wq))
745 		return;
746 
747 	/* wake up smc sk->sk_wq */
748 	if (!key) {
749 		/* sk_state_change */
750 		wake_up_interruptible_all(&wq->wait);
751 	} else {
752 		flags = key_to_poll(key);
753 		if (flags & (EPOLLIN | EPOLLOUT))
754 			/* sk_data_ready or sk_write_space */
755 			wake_up_interruptible_sync_poll(&wq->wait, flags);
756 		else if (flags & EPOLLERR)
757 			/* sk_error_report */
758 			wake_up_interruptible_poll(&wq->wait, flags);
759 	}
760 }
761 
762 static int smc_fback_mark_woken(wait_queue_entry_t *wait,
763 				unsigned int mode, int sync, void *key)
764 {
765 	struct smc_mark_woken *mark =
766 		container_of(wait, struct smc_mark_woken, wait_entry);
767 
768 	mark->woken = true;
769 	mark->key = key;
770 	return 0;
771 }
772 
773 static void smc_fback_forward_wakeup(struct smc_sock *smc, struct sock *clcsk,
774 				     void (*clcsock_callback)(struct sock *sk))
775 {
776 	struct smc_mark_woken mark = { .woken = false };
777 	struct socket_wq *wq;
778 
779 	init_waitqueue_func_entry(&mark.wait_entry,
780 				  smc_fback_mark_woken);
781 	rcu_read_lock();
782 	wq = rcu_dereference(clcsk->sk_wq);
783 	if (!wq)
784 		goto out;
785 	add_wait_queue(sk_sleep(clcsk), &mark.wait_entry);
786 	clcsock_callback(clcsk);
787 	remove_wait_queue(sk_sleep(clcsk), &mark.wait_entry);
788 
789 	if (mark.woken)
790 		smc_fback_wakeup_waitqueue(smc, mark.key);
791 out:
792 	rcu_read_unlock();
793 }
794 
795 static void smc_fback_state_change(struct sock *clcsk)
796 {
797 	struct smc_sock *smc;
798 
799 	read_lock_bh(&clcsk->sk_callback_lock);
800 	smc = smc_clcsock_user_data(clcsk);
801 	if (smc)
802 		smc_fback_forward_wakeup(smc, clcsk,
803 					 smc->clcsk_state_change);
804 	read_unlock_bh(&clcsk->sk_callback_lock);
805 }
806 
807 static void smc_fback_data_ready(struct sock *clcsk)
808 {
809 	struct smc_sock *smc;
810 
811 	read_lock_bh(&clcsk->sk_callback_lock);
812 	smc = smc_clcsock_user_data(clcsk);
813 	if (smc)
814 		smc_fback_forward_wakeup(smc, clcsk,
815 					 smc->clcsk_data_ready);
816 	read_unlock_bh(&clcsk->sk_callback_lock);
817 }
818 
819 static void smc_fback_write_space(struct sock *clcsk)
820 {
821 	struct smc_sock *smc;
822 
823 	read_lock_bh(&clcsk->sk_callback_lock);
824 	smc = smc_clcsock_user_data(clcsk);
825 	if (smc)
826 		smc_fback_forward_wakeup(smc, clcsk,
827 					 smc->clcsk_write_space);
828 	read_unlock_bh(&clcsk->sk_callback_lock);
829 }
830 
831 static void smc_fback_error_report(struct sock *clcsk)
832 {
833 	struct smc_sock *smc;
834 
835 	read_lock_bh(&clcsk->sk_callback_lock);
836 	smc = smc_clcsock_user_data(clcsk);
837 	if (smc)
838 		smc_fback_forward_wakeup(smc, clcsk,
839 					 smc->clcsk_error_report);
840 	read_unlock_bh(&clcsk->sk_callback_lock);
841 }
842 
843 static void smc_fback_replace_callbacks(struct smc_sock *smc)
844 {
845 	struct sock *clcsk = smc->clcsock->sk;
846 
847 	write_lock_bh(&clcsk->sk_callback_lock);
848 	clcsk->sk_user_data = (void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
849 
850 	smc_clcsock_replace_cb(&clcsk->sk_state_change, smc_fback_state_change,
851 			       &smc->clcsk_state_change);
852 	smc_clcsock_replace_cb(&clcsk->sk_data_ready, smc_fback_data_ready,
853 			       &smc->clcsk_data_ready);
854 	smc_clcsock_replace_cb(&clcsk->sk_write_space, smc_fback_write_space,
855 			       &smc->clcsk_write_space);
856 	smc_clcsock_replace_cb(&clcsk->sk_error_report, smc_fback_error_report,
857 			       &smc->clcsk_error_report);
858 
859 	write_unlock_bh(&clcsk->sk_callback_lock);
860 }
861 
862 static int smc_switch_to_fallback(struct smc_sock *smc, int reason_code)
863 {
864 	int rc = 0;
865 
866 	mutex_lock(&smc->clcsock_release_lock);
867 	if (!smc->clcsock) {
868 		rc = -EBADF;
869 		goto out;
870 	}
871 
872 	smc->use_fallback = true;
873 	smc->fallback_rsn = reason_code;
874 	smc_stat_fallback(smc);
875 	trace_smc_switch_to_fallback(smc, reason_code);
876 	if (smc->sk.sk_socket && smc->sk.sk_socket->file) {
877 		smc->clcsock->file = smc->sk.sk_socket->file;
878 		smc->clcsock->file->private_data = smc->clcsock;
879 		smc->clcsock->wq.fasync_list =
880 			smc->sk.sk_socket->wq.fasync_list;
881 
882 		/* There might be some wait entries remaining
883 		 * in smc sk->sk_wq and they should be woken up
884 		 * as clcsock's wait queue is woken up.
885 		 */
886 		smc_fback_replace_callbacks(smc);
887 	}
888 out:
889 	mutex_unlock(&smc->clcsock_release_lock);
890 	return rc;
891 }
892 
893 /* fall back during connect */
894 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
895 {
896 	struct net *net = sock_net(&smc->sk);
897 	int rc = 0;
898 
899 	rc = smc_switch_to_fallback(smc, reason_code);
900 	if (rc) { /* fallback fails */
901 		this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
902 		if (smc->sk.sk_state == SMC_INIT)
903 			sock_put(&smc->sk); /* passive closing */
904 		return rc;
905 	}
906 	smc_copy_sock_settings_to_clc(smc);
907 	smc->connect_nonblock = 0;
908 	if (smc->sk.sk_state == SMC_INIT)
909 		smc->sk.sk_state = SMC_ACTIVE;
910 	return 0;
911 }
912 
913 /* decline and fall back during connect */
914 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code,
915 					u8 version)
916 {
917 	struct net *net = sock_net(&smc->sk);
918 	int rc;
919 
920 	if (reason_code < 0) { /* error, fallback is not possible */
921 		this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
922 		if (smc->sk.sk_state == SMC_INIT)
923 			sock_put(&smc->sk); /* passive closing */
924 		return reason_code;
925 	}
926 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
927 		rc = smc_clc_send_decline(smc, reason_code, version);
928 		if (rc < 0) {
929 			this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
930 			if (smc->sk.sk_state == SMC_INIT)
931 				sock_put(&smc->sk); /* passive closing */
932 			return rc;
933 		}
934 	}
935 	return smc_connect_fallback(smc, reason_code);
936 }
937 
938 static void smc_conn_abort(struct smc_sock *smc, int local_first)
939 {
940 	struct smc_connection *conn = &smc->conn;
941 	struct smc_link_group *lgr = conn->lgr;
942 	bool lgr_valid = false;
943 
944 	if (smc_conn_lgr_valid(conn))
945 		lgr_valid = true;
946 
947 	smc_conn_free(conn);
948 	if (local_first && lgr_valid)
949 		smc_lgr_cleanup_early(lgr);
950 }
951 
952 /* check if there is a rdma device available for this connection. */
953 /* called for connect and listen */
954 static int smc_find_rdma_device(struct smc_sock *smc, struct smc_init_info *ini)
955 {
956 	/* PNET table look up: search active ib_device and port
957 	 * within same PNETID that also contains the ethernet device
958 	 * used for the internal TCP socket
959 	 */
960 	smc_pnet_find_roce_resource(smc->clcsock->sk, ini);
961 	if (!ini->check_smcrv2 && !ini->ib_dev)
962 		return SMC_CLC_DECL_NOSMCRDEV;
963 	if (ini->check_smcrv2 && !ini->smcrv2.ib_dev_v2)
964 		return SMC_CLC_DECL_NOSMCRDEV;
965 	return 0;
966 }
967 
968 /* check if there is an ISM device available for this connection. */
969 /* called for connect and listen */
970 static int smc_find_ism_device(struct smc_sock *smc, struct smc_init_info *ini)
971 {
972 	/* Find ISM device with same PNETID as connecting interface  */
973 	smc_pnet_find_ism_resource(smc->clcsock->sk, ini);
974 	if (!ini->ism_dev[0])
975 		return SMC_CLC_DECL_NOSMCDDEV;
976 	else
977 		ini->ism_chid[0] = smc_ism_get_chid(ini->ism_dev[0]);
978 	return 0;
979 }
980 
981 /* is chid unique for the ism devices that are already determined? */
982 static bool smc_find_ism_v2_is_unique_chid(u16 chid, struct smc_init_info *ini,
983 					   int cnt)
984 {
985 	int i = (!ini->ism_dev[0]) ? 1 : 0;
986 
987 	for (; i < cnt; i++)
988 		if (ini->ism_chid[i] == chid)
989 			return false;
990 	return true;
991 }
992 
993 /* determine possible V2 ISM devices (either without PNETID or with PNETID plus
994  * PNETID matching net_device)
995  */
996 static int smc_find_ism_v2_device_clnt(struct smc_sock *smc,
997 				       struct smc_init_info *ini)
998 {
999 	int rc = SMC_CLC_DECL_NOSMCDDEV;
1000 	struct smcd_dev *smcd;
1001 	int i = 1;
1002 	u16 chid;
1003 
1004 	if (smcd_indicated(ini->smc_type_v1))
1005 		rc = 0;		/* already initialized for V1 */
1006 	mutex_lock(&smcd_dev_list.mutex);
1007 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
1008 		if (smcd->going_away || smcd == ini->ism_dev[0])
1009 			continue;
1010 		chid = smc_ism_get_chid(smcd);
1011 		if (!smc_find_ism_v2_is_unique_chid(chid, ini, i))
1012 			continue;
1013 		if (!smc_pnet_is_pnetid_set(smcd->pnetid) ||
1014 		    smc_pnet_is_ndev_pnetid(sock_net(&smc->sk), smcd->pnetid)) {
1015 			ini->ism_dev[i] = smcd;
1016 			ini->ism_chid[i] = chid;
1017 			ini->is_smcd = true;
1018 			rc = 0;
1019 			i++;
1020 			if (i > SMC_MAX_ISM_DEVS)
1021 				break;
1022 		}
1023 	}
1024 	mutex_unlock(&smcd_dev_list.mutex);
1025 	ini->ism_offered_cnt = i - 1;
1026 	if (!ini->ism_dev[0] && !ini->ism_dev[1])
1027 		ini->smcd_version = 0;
1028 
1029 	return rc;
1030 }
1031 
1032 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
1033 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
1034 				      struct smc_init_info *ini)
1035 {
1036 	if (ini->vlan_id && smc_ism_get_vlan(ini->ism_dev[0], ini->vlan_id))
1037 		return SMC_CLC_DECL_ISMVLANERR;
1038 	return 0;
1039 }
1040 
1041 static int smc_find_proposal_devices(struct smc_sock *smc,
1042 				     struct smc_init_info *ini)
1043 {
1044 	int rc = 0;
1045 
1046 	/* check if there is an ism device available */
1047 	if (!(ini->smcd_version & SMC_V1) ||
1048 	    smc_find_ism_device(smc, ini) ||
1049 	    smc_connect_ism_vlan_setup(smc, ini))
1050 		ini->smcd_version &= ~SMC_V1;
1051 	/* else ISM V1 is supported for this connection */
1052 
1053 	/* check if there is an rdma device available */
1054 	if (!(ini->smcr_version & SMC_V1) ||
1055 	    smc_find_rdma_device(smc, ini))
1056 		ini->smcr_version &= ~SMC_V1;
1057 	/* else RDMA is supported for this connection */
1058 
1059 	ini->smc_type_v1 = smc_indicated_type(ini->smcd_version & SMC_V1,
1060 					      ini->smcr_version & SMC_V1);
1061 
1062 	/* check if there is an ism v2 device available */
1063 	if (!(ini->smcd_version & SMC_V2) ||
1064 	    !smc_ism_is_v2_capable() ||
1065 	    smc_find_ism_v2_device_clnt(smc, ini))
1066 		ini->smcd_version &= ~SMC_V2;
1067 
1068 	/* check if there is an rdma v2 device available */
1069 	ini->check_smcrv2 = true;
1070 	ini->smcrv2.saddr = smc->clcsock->sk->sk_rcv_saddr;
1071 	if (!(ini->smcr_version & SMC_V2) ||
1072 	    smc->clcsock->sk->sk_family != AF_INET ||
1073 	    !smc_clc_ueid_count() ||
1074 	    smc_find_rdma_device(smc, ini))
1075 		ini->smcr_version &= ~SMC_V2;
1076 	ini->check_smcrv2 = false;
1077 
1078 	ini->smc_type_v2 = smc_indicated_type(ini->smcd_version & SMC_V2,
1079 					      ini->smcr_version & SMC_V2);
1080 
1081 	/* if neither ISM nor RDMA are supported, fallback */
1082 	if (ini->smc_type_v1 == SMC_TYPE_N && ini->smc_type_v2 == SMC_TYPE_N)
1083 		rc = SMC_CLC_DECL_NOSMCDEV;
1084 
1085 	return rc;
1086 }
1087 
1088 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
1089  * used, the VLAN ID will be registered again during the connection setup.
1090  */
1091 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc,
1092 					struct smc_init_info *ini)
1093 {
1094 	if (!smcd_indicated(ini->smc_type_v1))
1095 		return 0;
1096 	if (ini->vlan_id && smc_ism_put_vlan(ini->ism_dev[0], ini->vlan_id))
1097 		return SMC_CLC_DECL_CNFERR;
1098 	return 0;
1099 }
1100 
1101 #define SMC_CLC_MAX_ACCEPT_LEN \
1102 	(sizeof(struct smc_clc_msg_accept_confirm_v2) + \
1103 	 sizeof(struct smc_clc_first_contact_ext) + \
1104 	 sizeof(struct smc_clc_msg_trail))
1105 
1106 /* CLC handshake during connect */
1107 static int smc_connect_clc(struct smc_sock *smc,
1108 			   struct smc_clc_msg_accept_confirm_v2 *aclc2,
1109 			   struct smc_init_info *ini)
1110 {
1111 	int rc = 0;
1112 
1113 	/* do inband token exchange */
1114 	rc = smc_clc_send_proposal(smc, ini);
1115 	if (rc)
1116 		return rc;
1117 	/* receive SMC Accept CLC message */
1118 	return smc_clc_wait_msg(smc, aclc2, SMC_CLC_MAX_ACCEPT_LEN,
1119 				SMC_CLC_ACCEPT, CLC_WAIT_TIME);
1120 }
1121 
1122 void smc_fill_gid_list(struct smc_link_group *lgr,
1123 		       struct smc_gidlist *gidlist,
1124 		       struct smc_ib_device *known_dev, u8 *known_gid)
1125 {
1126 	struct smc_init_info *alt_ini = NULL;
1127 
1128 	memset(gidlist, 0, sizeof(*gidlist));
1129 	memcpy(gidlist->list[gidlist->len++], known_gid, SMC_GID_SIZE);
1130 
1131 	alt_ini = kzalloc(sizeof(*alt_ini), GFP_KERNEL);
1132 	if (!alt_ini)
1133 		goto out;
1134 
1135 	alt_ini->vlan_id = lgr->vlan_id;
1136 	alt_ini->check_smcrv2 = true;
1137 	alt_ini->smcrv2.saddr = lgr->saddr;
1138 	smc_pnet_find_alt_roce(lgr, alt_ini, known_dev);
1139 
1140 	if (!alt_ini->smcrv2.ib_dev_v2)
1141 		goto out;
1142 
1143 	memcpy(gidlist->list[gidlist->len++], alt_ini->smcrv2.ib_gid_v2,
1144 	       SMC_GID_SIZE);
1145 
1146 out:
1147 	kfree(alt_ini);
1148 }
1149 
1150 static int smc_connect_rdma_v2_prepare(struct smc_sock *smc,
1151 				       struct smc_clc_msg_accept_confirm *aclc,
1152 				       struct smc_init_info *ini)
1153 {
1154 	struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
1155 		(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1156 	struct smc_clc_first_contact_ext *fce =
1157 		(struct smc_clc_first_contact_ext *)
1158 			(((u8 *)clc_v2) + sizeof(*clc_v2));
1159 
1160 	if (!ini->first_contact_peer || aclc->hdr.version == SMC_V1)
1161 		return 0;
1162 
1163 	if (fce->v2_direct) {
1164 		memcpy(ini->smcrv2.nexthop_mac, &aclc->r0.lcl.mac, ETH_ALEN);
1165 		ini->smcrv2.uses_gateway = false;
1166 	} else {
1167 		if (smc_ib_find_route(smc->clcsock->sk->sk_rcv_saddr,
1168 				      smc_ib_gid_to_ipv4(aclc->r0.lcl.gid),
1169 				      ini->smcrv2.nexthop_mac,
1170 				      &ini->smcrv2.uses_gateway))
1171 			return SMC_CLC_DECL_NOROUTE;
1172 		if (!ini->smcrv2.uses_gateway) {
1173 			/* mismatch: peer claims indirect, but its direct */
1174 			return SMC_CLC_DECL_NOINDIRECT;
1175 		}
1176 	}
1177 	return 0;
1178 }
1179 
1180 /* setup for RDMA connection of client */
1181 static int smc_connect_rdma(struct smc_sock *smc,
1182 			    struct smc_clc_msg_accept_confirm *aclc,
1183 			    struct smc_init_info *ini)
1184 {
1185 	int i, reason_code = 0;
1186 	struct smc_link *link;
1187 	u8 *eid = NULL;
1188 
1189 	ini->is_smcd = false;
1190 	ini->ib_clcqpn = ntoh24(aclc->r0.qpn);
1191 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
1192 	memcpy(ini->peer_systemid, aclc->r0.lcl.id_for_peer, SMC_SYSTEMID_LEN);
1193 	memcpy(ini->peer_gid, aclc->r0.lcl.gid, SMC_GID_SIZE);
1194 	memcpy(ini->peer_mac, aclc->r0.lcl.mac, ETH_ALEN);
1195 
1196 	reason_code = smc_connect_rdma_v2_prepare(smc, aclc, ini);
1197 	if (reason_code)
1198 		return reason_code;
1199 
1200 	mutex_lock(&smc_client_lgr_pending);
1201 	reason_code = smc_conn_create(smc, ini);
1202 	if (reason_code) {
1203 		mutex_unlock(&smc_client_lgr_pending);
1204 		return reason_code;
1205 	}
1206 
1207 	smc_conn_save_peer_info(smc, aclc);
1208 
1209 	if (ini->first_contact_local) {
1210 		link = smc->conn.lnk;
1211 	} else {
1212 		/* set link that was assigned by server */
1213 		link = NULL;
1214 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1215 			struct smc_link *l = &smc->conn.lgr->lnk[i];
1216 
1217 			if (l->peer_qpn == ntoh24(aclc->r0.qpn) &&
1218 			    !memcmp(l->peer_gid, &aclc->r0.lcl.gid,
1219 				    SMC_GID_SIZE) &&
1220 			    (aclc->hdr.version > SMC_V1 ||
1221 			     !memcmp(l->peer_mac, &aclc->r0.lcl.mac,
1222 				     sizeof(l->peer_mac)))) {
1223 				link = l;
1224 				break;
1225 			}
1226 		}
1227 		if (!link) {
1228 			reason_code = SMC_CLC_DECL_NOSRVLINK;
1229 			goto connect_abort;
1230 		}
1231 		smc_switch_link_and_count(&smc->conn, link);
1232 	}
1233 
1234 	/* create send buffer and rmb */
1235 	if (smc_buf_create(smc, false)) {
1236 		reason_code = SMC_CLC_DECL_MEM;
1237 		goto connect_abort;
1238 	}
1239 
1240 	if (ini->first_contact_local)
1241 		smc_link_save_peer_info(link, aclc, ini);
1242 
1243 	if (smc_rmb_rtoken_handling(&smc->conn, link, aclc)) {
1244 		reason_code = SMC_CLC_DECL_ERR_RTOK;
1245 		goto connect_abort;
1246 	}
1247 
1248 	smc_close_init(smc);
1249 	smc_rx_init(smc);
1250 
1251 	if (ini->first_contact_local) {
1252 		if (smc_ib_ready_link(link)) {
1253 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
1254 			goto connect_abort;
1255 		}
1256 	} else {
1257 		/* reg sendbufs if they were vzalloced */
1258 		if (smc->conn.sndbuf_desc->is_vm) {
1259 			if (smcr_lgr_reg_sndbufs(link, smc->conn.sndbuf_desc)) {
1260 				reason_code = SMC_CLC_DECL_ERR_REGBUF;
1261 				goto connect_abort;
1262 			}
1263 		}
1264 		if (smcr_lgr_reg_rmbs(link, smc->conn.rmb_desc)) {
1265 			reason_code = SMC_CLC_DECL_ERR_REGBUF;
1266 			goto connect_abort;
1267 		}
1268 	}
1269 
1270 	if (aclc->hdr.version > SMC_V1) {
1271 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
1272 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1273 
1274 		eid = clc_v2->r1.eid;
1275 		if (ini->first_contact_local)
1276 			smc_fill_gid_list(link->lgr, &ini->smcrv2.gidlist,
1277 					  link->smcibdev, link->gid);
1278 	}
1279 
1280 	reason_code = smc_clc_send_confirm(smc, ini->first_contact_local,
1281 					   aclc->hdr.version, eid, ini);
1282 	if (reason_code)
1283 		goto connect_abort;
1284 
1285 	smc_tx_init(smc);
1286 
1287 	if (ini->first_contact_local) {
1288 		/* QP confirmation over RoCE fabric */
1289 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
1290 		reason_code = smcr_clnt_conf_first_link(smc);
1291 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
1292 		if (reason_code)
1293 			goto connect_abort;
1294 	}
1295 	mutex_unlock(&smc_client_lgr_pending);
1296 
1297 	smc_copy_sock_settings_to_clc(smc);
1298 	smc->connect_nonblock = 0;
1299 	if (smc->sk.sk_state == SMC_INIT)
1300 		smc->sk.sk_state = SMC_ACTIVE;
1301 
1302 	return 0;
1303 connect_abort:
1304 	smc_conn_abort(smc, ini->first_contact_local);
1305 	mutex_unlock(&smc_client_lgr_pending);
1306 	smc->connect_nonblock = 0;
1307 
1308 	return reason_code;
1309 }
1310 
1311 /* The server has chosen one of the proposed ISM devices for the communication.
1312  * Determine from the CHID of the received CLC ACCEPT the ISM device chosen.
1313  */
1314 static int
1315 smc_v2_determine_accepted_chid(struct smc_clc_msg_accept_confirm_v2 *aclc,
1316 			       struct smc_init_info *ini)
1317 {
1318 	int i;
1319 
1320 	for (i = 0; i < ini->ism_offered_cnt + 1; i++) {
1321 		if (ini->ism_chid[i] == ntohs(aclc->d1.chid)) {
1322 			ini->ism_selected = i;
1323 			return 0;
1324 		}
1325 	}
1326 
1327 	return -EPROTO;
1328 }
1329 
1330 /* setup for ISM connection of client */
1331 static int smc_connect_ism(struct smc_sock *smc,
1332 			   struct smc_clc_msg_accept_confirm *aclc,
1333 			   struct smc_init_info *ini)
1334 {
1335 	u8 *eid = NULL;
1336 	int rc = 0;
1337 
1338 	ini->is_smcd = true;
1339 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
1340 
1341 	if (aclc->hdr.version == SMC_V2) {
1342 		struct smc_clc_msg_accept_confirm_v2 *aclc_v2 =
1343 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1344 
1345 		rc = smc_v2_determine_accepted_chid(aclc_v2, ini);
1346 		if (rc)
1347 			return rc;
1348 	}
1349 	ini->ism_peer_gid[ini->ism_selected] = aclc->d0.gid;
1350 
1351 	/* there is only one lgr role for SMC-D; use server lock */
1352 	mutex_lock(&smc_server_lgr_pending);
1353 	rc = smc_conn_create(smc, ini);
1354 	if (rc) {
1355 		mutex_unlock(&smc_server_lgr_pending);
1356 		return rc;
1357 	}
1358 
1359 	/* Create send and receive buffers */
1360 	rc = smc_buf_create(smc, true);
1361 	if (rc) {
1362 		rc = (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB : SMC_CLC_DECL_MEM;
1363 		goto connect_abort;
1364 	}
1365 
1366 	smc_conn_save_peer_info(smc, aclc);
1367 	smc_close_init(smc);
1368 	smc_rx_init(smc);
1369 	smc_tx_init(smc);
1370 
1371 	if (aclc->hdr.version > SMC_V1) {
1372 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
1373 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1374 
1375 		eid = clc_v2->d1.eid;
1376 	}
1377 
1378 	rc = smc_clc_send_confirm(smc, ini->first_contact_local,
1379 				  aclc->hdr.version, eid, NULL);
1380 	if (rc)
1381 		goto connect_abort;
1382 	mutex_unlock(&smc_server_lgr_pending);
1383 
1384 	smc_copy_sock_settings_to_clc(smc);
1385 	smc->connect_nonblock = 0;
1386 	if (smc->sk.sk_state == SMC_INIT)
1387 		smc->sk.sk_state = SMC_ACTIVE;
1388 
1389 	return 0;
1390 connect_abort:
1391 	smc_conn_abort(smc, ini->first_contact_local);
1392 	mutex_unlock(&smc_server_lgr_pending);
1393 	smc->connect_nonblock = 0;
1394 
1395 	return rc;
1396 }
1397 
1398 /* check if received accept type and version matches a proposed one */
1399 static int smc_connect_check_aclc(struct smc_init_info *ini,
1400 				  struct smc_clc_msg_accept_confirm *aclc)
1401 {
1402 	if (aclc->hdr.typev1 != SMC_TYPE_R &&
1403 	    aclc->hdr.typev1 != SMC_TYPE_D)
1404 		return SMC_CLC_DECL_MODEUNSUPP;
1405 
1406 	if (aclc->hdr.version >= SMC_V2) {
1407 		if ((aclc->hdr.typev1 == SMC_TYPE_R &&
1408 		     !smcr_indicated(ini->smc_type_v2)) ||
1409 		    (aclc->hdr.typev1 == SMC_TYPE_D &&
1410 		     !smcd_indicated(ini->smc_type_v2)))
1411 			return SMC_CLC_DECL_MODEUNSUPP;
1412 	} else {
1413 		if ((aclc->hdr.typev1 == SMC_TYPE_R &&
1414 		     !smcr_indicated(ini->smc_type_v1)) ||
1415 		    (aclc->hdr.typev1 == SMC_TYPE_D &&
1416 		     !smcd_indicated(ini->smc_type_v1)))
1417 			return SMC_CLC_DECL_MODEUNSUPP;
1418 	}
1419 
1420 	return 0;
1421 }
1422 
1423 /* perform steps before actually connecting */
1424 static int __smc_connect(struct smc_sock *smc)
1425 {
1426 	u8 version = smc_ism_is_v2_capable() ? SMC_V2 : SMC_V1;
1427 	struct smc_clc_msg_accept_confirm_v2 *aclc2;
1428 	struct smc_clc_msg_accept_confirm *aclc;
1429 	struct smc_init_info *ini = NULL;
1430 	u8 *buf = NULL;
1431 	int rc = 0;
1432 
1433 	if (smc->use_fallback)
1434 		return smc_connect_fallback(smc, smc->fallback_rsn);
1435 
1436 	/* if peer has not signalled SMC-capability, fall back */
1437 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
1438 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
1439 
1440 	/* IPSec connections opt out of SMC optimizations */
1441 	if (using_ipsec(smc))
1442 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC,
1443 						    version);
1444 
1445 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1446 	if (!ini)
1447 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_MEM,
1448 						    version);
1449 
1450 	ini->smcd_version = SMC_V1 | SMC_V2;
1451 	ini->smcr_version = SMC_V1 | SMC_V2;
1452 	ini->smc_type_v1 = SMC_TYPE_B;
1453 	ini->smc_type_v2 = SMC_TYPE_B;
1454 
1455 	/* get vlan id from IP device */
1456 	if (smc_vlan_by_tcpsk(smc->clcsock, ini)) {
1457 		ini->smcd_version &= ~SMC_V1;
1458 		ini->smcr_version = 0;
1459 		ini->smc_type_v1 = SMC_TYPE_N;
1460 		if (!ini->smcd_version) {
1461 			rc = SMC_CLC_DECL_GETVLANERR;
1462 			goto fallback;
1463 		}
1464 	}
1465 
1466 	rc = smc_find_proposal_devices(smc, ini);
1467 	if (rc)
1468 		goto fallback;
1469 
1470 	buf = kzalloc(SMC_CLC_MAX_ACCEPT_LEN, GFP_KERNEL);
1471 	if (!buf) {
1472 		rc = SMC_CLC_DECL_MEM;
1473 		goto fallback;
1474 	}
1475 	aclc2 = (struct smc_clc_msg_accept_confirm_v2 *)buf;
1476 	aclc = (struct smc_clc_msg_accept_confirm *)aclc2;
1477 
1478 	/* perform CLC handshake */
1479 	rc = smc_connect_clc(smc, aclc2, ini);
1480 	if (rc) {
1481 		/* -EAGAIN on timeout, see tcp_recvmsg() */
1482 		if (rc == -EAGAIN) {
1483 			rc = -ETIMEDOUT;
1484 			smc->sk.sk_err = ETIMEDOUT;
1485 		}
1486 		goto vlan_cleanup;
1487 	}
1488 
1489 	/* check if smc modes and versions of CLC proposal and accept match */
1490 	rc = smc_connect_check_aclc(ini, aclc);
1491 	version = aclc->hdr.version == SMC_V1 ? SMC_V1 : SMC_V2;
1492 	if (rc)
1493 		goto vlan_cleanup;
1494 
1495 	/* depending on previous steps, connect using rdma or ism */
1496 	if (aclc->hdr.typev1 == SMC_TYPE_R) {
1497 		ini->smcr_version = version;
1498 		rc = smc_connect_rdma(smc, aclc, ini);
1499 	} else if (aclc->hdr.typev1 == SMC_TYPE_D) {
1500 		ini->smcd_version = version;
1501 		rc = smc_connect_ism(smc, aclc, ini);
1502 	}
1503 	if (rc)
1504 		goto vlan_cleanup;
1505 
1506 	SMC_STAT_CLNT_SUCC_INC(sock_net(smc->clcsock->sk), aclc);
1507 	smc_connect_ism_vlan_cleanup(smc, ini);
1508 	kfree(buf);
1509 	kfree(ini);
1510 	return 0;
1511 
1512 vlan_cleanup:
1513 	smc_connect_ism_vlan_cleanup(smc, ini);
1514 	kfree(buf);
1515 fallback:
1516 	kfree(ini);
1517 	return smc_connect_decline_fallback(smc, rc, version);
1518 }
1519 
1520 static void smc_connect_work(struct work_struct *work)
1521 {
1522 	struct smc_sock *smc = container_of(work, struct smc_sock,
1523 					    connect_work);
1524 	long timeo = smc->sk.sk_sndtimeo;
1525 	int rc = 0;
1526 
1527 	if (!timeo)
1528 		timeo = MAX_SCHEDULE_TIMEOUT;
1529 	lock_sock(smc->clcsock->sk);
1530 	if (smc->clcsock->sk->sk_err) {
1531 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
1532 	} else if ((1 << smc->clcsock->sk->sk_state) &
1533 					(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
1534 		rc = sk_stream_wait_connect(smc->clcsock->sk, &timeo);
1535 		if ((rc == -EPIPE) &&
1536 		    ((1 << smc->clcsock->sk->sk_state) &
1537 					(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))
1538 			rc = 0;
1539 	}
1540 	release_sock(smc->clcsock->sk);
1541 	lock_sock(&smc->sk);
1542 	if (rc != 0 || smc->sk.sk_err) {
1543 		smc->sk.sk_state = SMC_CLOSED;
1544 		if (rc == -EPIPE || rc == -EAGAIN)
1545 			smc->sk.sk_err = EPIPE;
1546 		else if (rc == -ECONNREFUSED)
1547 			smc->sk.sk_err = ECONNREFUSED;
1548 		else if (signal_pending(current))
1549 			smc->sk.sk_err = -sock_intr_errno(timeo);
1550 		sock_put(&smc->sk); /* passive closing */
1551 		goto out;
1552 	}
1553 
1554 	rc = __smc_connect(smc);
1555 	if (rc < 0)
1556 		smc->sk.sk_err = -rc;
1557 
1558 out:
1559 	if (!sock_flag(&smc->sk, SOCK_DEAD)) {
1560 		if (smc->sk.sk_err) {
1561 			smc->sk.sk_state_change(&smc->sk);
1562 		} else { /* allow polling before and after fallback decision */
1563 			smc->clcsock->sk->sk_write_space(smc->clcsock->sk);
1564 			smc->sk.sk_write_space(&smc->sk);
1565 		}
1566 	}
1567 	release_sock(&smc->sk);
1568 }
1569 
1570 static int smc_connect(struct socket *sock, struct sockaddr *addr,
1571 		       int alen, int flags)
1572 {
1573 	struct sock *sk = sock->sk;
1574 	struct smc_sock *smc;
1575 	int rc = -EINVAL;
1576 
1577 	smc = smc_sk(sk);
1578 
1579 	/* separate smc parameter checking to be safe */
1580 	if (alen < sizeof(addr->sa_family))
1581 		goto out_err;
1582 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
1583 		goto out_err;
1584 
1585 	lock_sock(sk);
1586 	switch (sock->state) {
1587 	default:
1588 		rc = -EINVAL;
1589 		goto out;
1590 	case SS_CONNECTED:
1591 		rc = sk->sk_state == SMC_ACTIVE ? -EISCONN : -EINVAL;
1592 		goto out;
1593 	case SS_CONNECTING:
1594 		if (sk->sk_state == SMC_ACTIVE)
1595 			goto connected;
1596 		break;
1597 	case SS_UNCONNECTED:
1598 		sock->state = SS_CONNECTING;
1599 		break;
1600 	}
1601 
1602 	switch (sk->sk_state) {
1603 	default:
1604 		goto out;
1605 	case SMC_CLOSED:
1606 		rc = sock_error(sk) ? : -ECONNABORTED;
1607 		sock->state = SS_UNCONNECTED;
1608 		goto out;
1609 	case SMC_ACTIVE:
1610 		rc = -EISCONN;
1611 		goto out;
1612 	case SMC_INIT:
1613 		break;
1614 	}
1615 
1616 	smc_copy_sock_settings_to_clc(smc);
1617 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1618 	if (smc->connect_nonblock) {
1619 		rc = -EALREADY;
1620 		goto out;
1621 	}
1622 	rc = kernel_connect(smc->clcsock, addr, alen, flags);
1623 	if (rc && rc != -EINPROGRESS)
1624 		goto out;
1625 
1626 	if (smc->use_fallback) {
1627 		sock->state = rc ? SS_CONNECTING : SS_CONNECTED;
1628 		goto out;
1629 	}
1630 	sock_hold(&smc->sk); /* sock put in passive closing */
1631 	if (flags & O_NONBLOCK) {
1632 		if (queue_work(smc_hs_wq, &smc->connect_work))
1633 			smc->connect_nonblock = 1;
1634 		rc = -EINPROGRESS;
1635 		goto out;
1636 	} else {
1637 		rc = __smc_connect(smc);
1638 		if (rc < 0)
1639 			goto out;
1640 	}
1641 
1642 connected:
1643 	rc = 0;
1644 	sock->state = SS_CONNECTED;
1645 out:
1646 	release_sock(sk);
1647 out_err:
1648 	return rc;
1649 }
1650 
1651 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
1652 {
1653 	struct socket *new_clcsock = NULL;
1654 	struct sock *lsk = &lsmc->sk;
1655 	struct sock *new_sk;
1656 	int rc = -EINVAL;
1657 
1658 	release_sock(lsk);
1659 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
1660 	if (!new_sk) {
1661 		rc = -ENOMEM;
1662 		lsk->sk_err = ENOMEM;
1663 		*new_smc = NULL;
1664 		lock_sock(lsk);
1665 		goto out;
1666 	}
1667 	*new_smc = smc_sk(new_sk);
1668 
1669 	mutex_lock(&lsmc->clcsock_release_lock);
1670 	if (lsmc->clcsock)
1671 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, SOCK_NONBLOCK);
1672 	mutex_unlock(&lsmc->clcsock_release_lock);
1673 	lock_sock(lsk);
1674 	if  (rc < 0 && rc != -EAGAIN)
1675 		lsk->sk_err = -rc;
1676 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
1677 		new_sk->sk_prot->unhash(new_sk);
1678 		if (new_clcsock)
1679 			sock_release(new_clcsock);
1680 		new_sk->sk_state = SMC_CLOSED;
1681 		sock_set_flag(new_sk, SOCK_DEAD);
1682 		sock_put(new_sk); /* final */
1683 		*new_smc = NULL;
1684 		goto out;
1685 	}
1686 
1687 	/* new clcsock has inherited the smc listen-specific sk_data_ready
1688 	 * function; switch it back to the original sk_data_ready function
1689 	 */
1690 	new_clcsock->sk->sk_data_ready = lsmc->clcsk_data_ready;
1691 
1692 	/* if new clcsock has also inherited the fallback-specific callback
1693 	 * functions, switch them back to the original ones.
1694 	 */
1695 	if (lsmc->use_fallback) {
1696 		if (lsmc->clcsk_state_change)
1697 			new_clcsock->sk->sk_state_change = lsmc->clcsk_state_change;
1698 		if (lsmc->clcsk_write_space)
1699 			new_clcsock->sk->sk_write_space = lsmc->clcsk_write_space;
1700 		if (lsmc->clcsk_error_report)
1701 			new_clcsock->sk->sk_error_report = lsmc->clcsk_error_report;
1702 	}
1703 
1704 	(*new_smc)->clcsock = new_clcsock;
1705 out:
1706 	return rc;
1707 }
1708 
1709 /* add a just created sock to the accept queue of the listen sock as
1710  * candidate for a following socket accept call from user space
1711  */
1712 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
1713 {
1714 	struct smc_sock *par = smc_sk(parent);
1715 
1716 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
1717 	spin_lock(&par->accept_q_lock);
1718 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
1719 	spin_unlock(&par->accept_q_lock);
1720 	sk_acceptq_added(parent);
1721 }
1722 
1723 /* remove a socket from the accept queue of its parental listening socket */
1724 static void smc_accept_unlink(struct sock *sk)
1725 {
1726 	struct smc_sock *par = smc_sk(sk)->listen_smc;
1727 
1728 	spin_lock(&par->accept_q_lock);
1729 	list_del_init(&smc_sk(sk)->accept_q);
1730 	spin_unlock(&par->accept_q_lock);
1731 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
1732 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
1733 }
1734 
1735 /* remove a sock from the accept queue to bind it to a new socket created
1736  * for a socket accept call from user space
1737  */
1738 struct sock *smc_accept_dequeue(struct sock *parent,
1739 				struct socket *new_sock)
1740 {
1741 	struct smc_sock *isk, *n;
1742 	struct sock *new_sk;
1743 
1744 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
1745 		new_sk = (struct sock *)isk;
1746 
1747 		smc_accept_unlink(new_sk);
1748 		if (new_sk->sk_state == SMC_CLOSED) {
1749 			new_sk->sk_prot->unhash(new_sk);
1750 			if (isk->clcsock) {
1751 				sock_release(isk->clcsock);
1752 				isk->clcsock = NULL;
1753 			}
1754 			sock_put(new_sk); /* final */
1755 			continue;
1756 		}
1757 		if (new_sock) {
1758 			sock_graft(new_sk, new_sock);
1759 			new_sock->state = SS_CONNECTED;
1760 			if (isk->use_fallback) {
1761 				smc_sk(new_sk)->clcsock->file = new_sock->file;
1762 				isk->clcsock->file->private_data = isk->clcsock;
1763 			}
1764 		}
1765 		return new_sk;
1766 	}
1767 	return NULL;
1768 }
1769 
1770 /* clean up for a created but never accepted sock */
1771 void smc_close_non_accepted(struct sock *sk)
1772 {
1773 	struct smc_sock *smc = smc_sk(sk);
1774 
1775 	sock_hold(sk); /* sock_put below */
1776 	lock_sock(sk);
1777 	if (!sk->sk_lingertime)
1778 		/* wait for peer closing */
1779 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
1780 	__smc_release(smc);
1781 	release_sock(sk);
1782 	sock_put(sk); /* sock_hold above */
1783 	sock_put(sk); /* final sock_put */
1784 }
1785 
1786 static int smcr_serv_conf_first_link(struct smc_sock *smc)
1787 {
1788 	struct smc_link *link = smc->conn.lnk;
1789 	struct smc_llc_qentry *qentry;
1790 	int rc;
1791 
1792 	/* reg the sndbuf if it was vzalloced*/
1793 	if (smc->conn.sndbuf_desc->is_vm) {
1794 		if (smcr_link_reg_buf(link, smc->conn.sndbuf_desc))
1795 			return SMC_CLC_DECL_ERR_REGBUF;
1796 	}
1797 
1798 	/* reg the rmb */
1799 	if (smcr_link_reg_buf(link, smc->conn.rmb_desc))
1800 		return SMC_CLC_DECL_ERR_REGBUF;
1801 
1802 	/* send CONFIRM LINK request to client over the RoCE fabric */
1803 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
1804 	if (rc < 0)
1805 		return SMC_CLC_DECL_TIMEOUT_CL;
1806 
1807 	/* receive CONFIRM LINK response from client over the RoCE fabric */
1808 	qentry = smc_llc_wait(link->lgr, link, SMC_LLC_WAIT_TIME,
1809 			      SMC_LLC_CONFIRM_LINK);
1810 	if (!qentry) {
1811 		struct smc_clc_msg_decline dclc;
1812 
1813 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1814 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1815 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
1816 	}
1817 	smc_llc_save_peer_uid(qentry);
1818 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_RESP);
1819 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
1820 	if (rc)
1821 		return SMC_CLC_DECL_RMBE_EC;
1822 
1823 	/* confirm_rkey is implicit on 1st contact */
1824 	smc->conn.rmb_desc->is_conf_rkey = true;
1825 
1826 	smc_llc_link_active(link);
1827 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
1828 
1829 	/* initial contact - try to establish second link */
1830 	smc_llc_srv_add_link(link, NULL);
1831 	return 0;
1832 }
1833 
1834 /* listen worker: finish */
1835 static void smc_listen_out(struct smc_sock *new_smc)
1836 {
1837 	struct smc_sock *lsmc = new_smc->listen_smc;
1838 	struct sock *newsmcsk = &new_smc->sk;
1839 
1840 	if (tcp_sk(new_smc->clcsock->sk)->syn_smc)
1841 		atomic_dec(&lsmc->queued_smc_hs);
1842 
1843 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1844 		lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1845 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1846 		release_sock(&lsmc->sk);
1847 	} else { /* no longer listening */
1848 		smc_close_non_accepted(newsmcsk);
1849 	}
1850 
1851 	/* Wake up accept */
1852 	lsmc->sk.sk_data_ready(&lsmc->sk);
1853 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1854 }
1855 
1856 /* listen worker: finish in state connected */
1857 static void smc_listen_out_connected(struct smc_sock *new_smc)
1858 {
1859 	struct sock *newsmcsk = &new_smc->sk;
1860 
1861 	if (newsmcsk->sk_state == SMC_INIT)
1862 		newsmcsk->sk_state = SMC_ACTIVE;
1863 
1864 	smc_listen_out(new_smc);
1865 }
1866 
1867 /* listen worker: finish in error state */
1868 static void smc_listen_out_err(struct smc_sock *new_smc)
1869 {
1870 	struct sock *newsmcsk = &new_smc->sk;
1871 	struct net *net = sock_net(newsmcsk);
1872 
1873 	this_cpu_inc(net->smc.smc_stats->srv_hshake_err_cnt);
1874 	if (newsmcsk->sk_state == SMC_INIT)
1875 		sock_put(&new_smc->sk); /* passive closing */
1876 	newsmcsk->sk_state = SMC_CLOSED;
1877 
1878 	smc_listen_out(new_smc);
1879 }
1880 
1881 /* listen worker: decline and fall back if possible */
1882 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1883 			       int local_first, u8 version)
1884 {
1885 	/* RDMA setup failed, switch back to TCP */
1886 	smc_conn_abort(new_smc, local_first);
1887 	if (reason_code < 0 ||
1888 	    smc_switch_to_fallback(new_smc, reason_code)) {
1889 		/* error, no fallback possible */
1890 		smc_listen_out_err(new_smc);
1891 		return;
1892 	}
1893 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1894 		if (smc_clc_send_decline(new_smc, reason_code, version) < 0) {
1895 			smc_listen_out_err(new_smc);
1896 			return;
1897 		}
1898 	}
1899 	smc_listen_out_connected(new_smc);
1900 }
1901 
1902 /* listen worker: version checking */
1903 static int smc_listen_v2_check(struct smc_sock *new_smc,
1904 			       struct smc_clc_msg_proposal *pclc,
1905 			       struct smc_init_info *ini)
1906 {
1907 	struct smc_clc_smcd_v2_extension *pclc_smcd_v2_ext;
1908 	struct smc_clc_v2_extension *pclc_v2_ext;
1909 	int rc = SMC_CLC_DECL_PEERNOSMC;
1910 
1911 	ini->smc_type_v1 = pclc->hdr.typev1;
1912 	ini->smc_type_v2 = pclc->hdr.typev2;
1913 	ini->smcd_version = smcd_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
1914 	ini->smcr_version = smcr_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
1915 	if (pclc->hdr.version > SMC_V1) {
1916 		if (smcd_indicated(ini->smc_type_v2))
1917 			ini->smcd_version |= SMC_V2;
1918 		if (smcr_indicated(ini->smc_type_v2))
1919 			ini->smcr_version |= SMC_V2;
1920 	}
1921 	if (!(ini->smcd_version & SMC_V2) && !(ini->smcr_version & SMC_V2)) {
1922 		rc = SMC_CLC_DECL_PEERNOSMC;
1923 		goto out;
1924 	}
1925 	pclc_v2_ext = smc_get_clc_v2_ext(pclc);
1926 	if (!pclc_v2_ext) {
1927 		ini->smcd_version &= ~SMC_V2;
1928 		ini->smcr_version &= ~SMC_V2;
1929 		rc = SMC_CLC_DECL_NOV2EXT;
1930 		goto out;
1931 	}
1932 	pclc_smcd_v2_ext = smc_get_clc_smcd_v2_ext(pclc_v2_ext);
1933 	if (ini->smcd_version & SMC_V2) {
1934 		if (!smc_ism_is_v2_capable()) {
1935 			ini->smcd_version &= ~SMC_V2;
1936 			rc = SMC_CLC_DECL_NOISM2SUPP;
1937 		} else if (!pclc_smcd_v2_ext) {
1938 			ini->smcd_version &= ~SMC_V2;
1939 			rc = SMC_CLC_DECL_NOV2DEXT;
1940 		} else if (!pclc_v2_ext->hdr.eid_cnt &&
1941 			   !pclc_v2_ext->hdr.flag.seid) {
1942 			ini->smcd_version &= ~SMC_V2;
1943 			rc = SMC_CLC_DECL_NOUEID;
1944 		}
1945 	}
1946 	if (ini->smcr_version & SMC_V2) {
1947 		if (!pclc_v2_ext->hdr.eid_cnt) {
1948 			ini->smcr_version &= ~SMC_V2;
1949 			rc = SMC_CLC_DECL_NOUEID;
1950 		}
1951 	}
1952 
1953 out:
1954 	if (!ini->smcd_version && !ini->smcr_version)
1955 		return rc;
1956 
1957 	return 0;
1958 }
1959 
1960 /* listen worker: check prefixes */
1961 static int smc_listen_prfx_check(struct smc_sock *new_smc,
1962 				 struct smc_clc_msg_proposal *pclc)
1963 {
1964 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1965 	struct socket *newclcsock = new_smc->clcsock;
1966 
1967 	if (pclc->hdr.typev1 == SMC_TYPE_N)
1968 		return 0;
1969 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1970 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1971 		return SMC_CLC_DECL_DIFFPREFIX;
1972 
1973 	return 0;
1974 }
1975 
1976 /* listen worker: initialize connection and buffers */
1977 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1978 				struct smc_init_info *ini)
1979 {
1980 	int rc;
1981 
1982 	/* allocate connection / link group */
1983 	rc = smc_conn_create(new_smc, ini);
1984 	if (rc)
1985 		return rc;
1986 
1987 	/* create send buffer and rmb */
1988 	if (smc_buf_create(new_smc, false))
1989 		return SMC_CLC_DECL_MEM;
1990 
1991 	return 0;
1992 }
1993 
1994 /* listen worker: initialize connection and buffers for SMC-D */
1995 static int smc_listen_ism_init(struct smc_sock *new_smc,
1996 			       struct smc_init_info *ini)
1997 {
1998 	int rc;
1999 
2000 	rc = smc_conn_create(new_smc, ini);
2001 	if (rc)
2002 		return rc;
2003 
2004 	/* Create send and receive buffers */
2005 	rc = smc_buf_create(new_smc, true);
2006 	if (rc) {
2007 		smc_conn_abort(new_smc, ini->first_contact_local);
2008 		return (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB :
2009 					 SMC_CLC_DECL_MEM;
2010 	}
2011 
2012 	return 0;
2013 }
2014 
2015 static bool smc_is_already_selected(struct smcd_dev *smcd,
2016 				    struct smc_init_info *ini,
2017 				    int matches)
2018 {
2019 	int i;
2020 
2021 	for (i = 0; i < matches; i++)
2022 		if (smcd == ini->ism_dev[i])
2023 			return true;
2024 
2025 	return false;
2026 }
2027 
2028 /* check for ISM devices matching proposed ISM devices */
2029 static void smc_check_ism_v2_match(struct smc_init_info *ini,
2030 				   u16 proposed_chid, u64 proposed_gid,
2031 				   unsigned int *matches)
2032 {
2033 	struct smcd_dev *smcd;
2034 
2035 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
2036 		if (smcd->going_away)
2037 			continue;
2038 		if (smc_is_already_selected(smcd, ini, *matches))
2039 			continue;
2040 		if (smc_ism_get_chid(smcd) == proposed_chid &&
2041 		    !smc_ism_cantalk(proposed_gid, ISM_RESERVED_VLANID, smcd)) {
2042 			ini->ism_peer_gid[*matches] = proposed_gid;
2043 			ini->ism_dev[*matches] = smcd;
2044 			(*matches)++;
2045 			break;
2046 		}
2047 	}
2048 }
2049 
2050 static void smc_find_ism_store_rc(u32 rc, struct smc_init_info *ini)
2051 {
2052 	if (!ini->rc)
2053 		ini->rc = rc;
2054 }
2055 
2056 static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
2057 					struct smc_clc_msg_proposal *pclc,
2058 					struct smc_init_info *ini)
2059 {
2060 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
2061 	struct smc_clc_v2_extension *smc_v2_ext;
2062 	struct smc_clc_msg_smcd *pclc_smcd;
2063 	unsigned int matches = 0;
2064 	u8 smcd_version;
2065 	u8 *eid = NULL;
2066 	int i, rc;
2067 
2068 	if (!(ini->smcd_version & SMC_V2) || !smcd_indicated(ini->smc_type_v2))
2069 		goto not_found;
2070 
2071 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
2072 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
2073 	smcd_v2_ext = smc_get_clc_smcd_v2_ext(smc_v2_ext);
2074 
2075 	mutex_lock(&smcd_dev_list.mutex);
2076 	if (pclc_smcd->ism.chid)
2077 		/* check for ISM device matching proposed native ISM device */
2078 		smc_check_ism_v2_match(ini, ntohs(pclc_smcd->ism.chid),
2079 				       ntohll(pclc_smcd->ism.gid), &matches);
2080 	for (i = 1; i <= smc_v2_ext->hdr.ism_gid_cnt; i++) {
2081 		/* check for ISM devices matching proposed non-native ISM
2082 		 * devices
2083 		 */
2084 		smc_check_ism_v2_match(ini,
2085 				       ntohs(smcd_v2_ext->gidchid[i - 1].chid),
2086 				       ntohll(smcd_v2_ext->gidchid[i - 1].gid),
2087 				       &matches);
2088 	}
2089 	mutex_unlock(&smcd_dev_list.mutex);
2090 
2091 	if (!ini->ism_dev[0]) {
2092 		smc_find_ism_store_rc(SMC_CLC_DECL_NOSMCD2DEV, ini);
2093 		goto not_found;
2094 	}
2095 
2096 	smc_ism_get_system_eid(&eid);
2097 	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext,
2098 			       smcd_v2_ext->system_eid, eid))
2099 		goto not_found;
2100 
2101 	/* separate - outside the smcd_dev_list.lock */
2102 	smcd_version = ini->smcd_version;
2103 	for (i = 0; i < matches; i++) {
2104 		ini->smcd_version = SMC_V2;
2105 		ini->is_smcd = true;
2106 		ini->ism_selected = i;
2107 		rc = smc_listen_ism_init(new_smc, ini);
2108 		if (rc) {
2109 			smc_find_ism_store_rc(rc, ini);
2110 			/* try next active ISM device */
2111 			continue;
2112 		}
2113 		return; /* matching and usable V2 ISM device found */
2114 	}
2115 	/* no V2 ISM device could be initialized */
2116 	ini->smcd_version = smcd_version;	/* restore original value */
2117 	ini->negotiated_eid[0] = 0;
2118 
2119 not_found:
2120 	ini->smcd_version &= ~SMC_V2;
2121 	ini->ism_dev[0] = NULL;
2122 	ini->is_smcd = false;
2123 }
2124 
2125 static void smc_find_ism_v1_device_serv(struct smc_sock *new_smc,
2126 					struct smc_clc_msg_proposal *pclc,
2127 					struct smc_init_info *ini)
2128 {
2129 	struct smc_clc_msg_smcd *pclc_smcd = smc_get_clc_msg_smcd(pclc);
2130 	int rc = 0;
2131 
2132 	/* check if ISM V1 is available */
2133 	if (!(ini->smcd_version & SMC_V1) || !smcd_indicated(ini->smc_type_v1))
2134 		goto not_found;
2135 	ini->is_smcd = true; /* prepare ISM check */
2136 	ini->ism_peer_gid[0] = ntohll(pclc_smcd->ism.gid);
2137 	rc = smc_find_ism_device(new_smc, ini);
2138 	if (rc)
2139 		goto not_found;
2140 	ini->ism_selected = 0;
2141 	rc = smc_listen_ism_init(new_smc, ini);
2142 	if (!rc)
2143 		return;		/* V1 ISM device found */
2144 
2145 not_found:
2146 	smc_find_ism_store_rc(rc, ini);
2147 	ini->smcd_version &= ~SMC_V1;
2148 	ini->ism_dev[0] = NULL;
2149 	ini->is_smcd = false;
2150 }
2151 
2152 /* listen worker: register buffers */
2153 static int smc_listen_rdma_reg(struct smc_sock *new_smc, bool local_first)
2154 {
2155 	struct smc_connection *conn = &new_smc->conn;
2156 
2157 	if (!local_first) {
2158 		/* reg sendbufs if they were vzalloced */
2159 		if (conn->sndbuf_desc->is_vm) {
2160 			if (smcr_lgr_reg_sndbufs(conn->lnk,
2161 						 conn->sndbuf_desc))
2162 				return SMC_CLC_DECL_ERR_REGBUF;
2163 		}
2164 		if (smcr_lgr_reg_rmbs(conn->lnk, conn->rmb_desc))
2165 			return SMC_CLC_DECL_ERR_REGBUF;
2166 	}
2167 
2168 	return 0;
2169 }
2170 
2171 static void smc_find_rdma_v2_device_serv(struct smc_sock *new_smc,
2172 					 struct smc_clc_msg_proposal *pclc,
2173 					 struct smc_init_info *ini)
2174 {
2175 	struct smc_clc_v2_extension *smc_v2_ext;
2176 	u8 smcr_version;
2177 	int rc;
2178 
2179 	if (!(ini->smcr_version & SMC_V2) || !smcr_indicated(ini->smc_type_v2))
2180 		goto not_found;
2181 
2182 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
2183 	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext, NULL, NULL))
2184 		goto not_found;
2185 
2186 	/* prepare RDMA check */
2187 	memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
2188 	memcpy(ini->peer_gid, smc_v2_ext->roce, SMC_GID_SIZE);
2189 	memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
2190 	ini->check_smcrv2 = true;
2191 	ini->smcrv2.clc_sk = new_smc->clcsock->sk;
2192 	ini->smcrv2.saddr = new_smc->clcsock->sk->sk_rcv_saddr;
2193 	ini->smcrv2.daddr = smc_ib_gid_to_ipv4(smc_v2_ext->roce);
2194 	rc = smc_find_rdma_device(new_smc, ini);
2195 	if (rc) {
2196 		smc_find_ism_store_rc(rc, ini);
2197 		goto not_found;
2198 	}
2199 	if (!ini->smcrv2.uses_gateway)
2200 		memcpy(ini->smcrv2.nexthop_mac, pclc->lcl.mac, ETH_ALEN);
2201 
2202 	smcr_version = ini->smcr_version;
2203 	ini->smcr_version = SMC_V2;
2204 	rc = smc_listen_rdma_init(new_smc, ini);
2205 	if (!rc)
2206 		rc = smc_listen_rdma_reg(new_smc, ini->first_contact_local);
2207 	if (!rc)
2208 		return;
2209 	ini->smcr_version = smcr_version;
2210 	smc_find_ism_store_rc(rc, ini);
2211 
2212 not_found:
2213 	ini->smcr_version &= ~SMC_V2;
2214 	ini->smcrv2.ib_dev_v2 = NULL;
2215 	ini->check_smcrv2 = false;
2216 }
2217 
2218 static int smc_find_rdma_v1_device_serv(struct smc_sock *new_smc,
2219 					struct smc_clc_msg_proposal *pclc,
2220 					struct smc_init_info *ini)
2221 {
2222 	int rc;
2223 
2224 	if (!(ini->smcr_version & SMC_V1) || !smcr_indicated(ini->smc_type_v1))
2225 		return SMC_CLC_DECL_NOSMCDEV;
2226 
2227 	/* prepare RDMA check */
2228 	memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
2229 	memcpy(ini->peer_gid, pclc->lcl.gid, SMC_GID_SIZE);
2230 	memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
2231 	rc = smc_find_rdma_device(new_smc, ini);
2232 	if (rc) {
2233 		/* no RDMA device found */
2234 		return SMC_CLC_DECL_NOSMCDEV;
2235 	}
2236 	rc = smc_listen_rdma_init(new_smc, ini);
2237 	if (rc)
2238 		return rc;
2239 	return smc_listen_rdma_reg(new_smc, ini->first_contact_local);
2240 }
2241 
2242 /* determine the local device matching to proposal */
2243 static int smc_listen_find_device(struct smc_sock *new_smc,
2244 				  struct smc_clc_msg_proposal *pclc,
2245 				  struct smc_init_info *ini)
2246 {
2247 	int prfx_rc;
2248 
2249 	/* check for ISM device matching V2 proposed device */
2250 	smc_find_ism_v2_device_serv(new_smc, pclc, ini);
2251 	if (ini->ism_dev[0])
2252 		return 0;
2253 
2254 	/* check for matching IP prefix and subnet length (V1) */
2255 	prfx_rc = smc_listen_prfx_check(new_smc, pclc);
2256 	if (prfx_rc)
2257 		smc_find_ism_store_rc(prfx_rc, ini);
2258 
2259 	/* get vlan id from IP device */
2260 	if (smc_vlan_by_tcpsk(new_smc->clcsock, ini))
2261 		return ini->rc ?: SMC_CLC_DECL_GETVLANERR;
2262 
2263 	/* check for ISM device matching V1 proposed device */
2264 	if (!prfx_rc)
2265 		smc_find_ism_v1_device_serv(new_smc, pclc, ini);
2266 	if (ini->ism_dev[0])
2267 		return 0;
2268 
2269 	if (!smcr_indicated(pclc->hdr.typev1) &&
2270 	    !smcr_indicated(pclc->hdr.typev2))
2271 		/* skip RDMA and decline */
2272 		return ini->rc ?: SMC_CLC_DECL_NOSMCDDEV;
2273 
2274 	/* check if RDMA V2 is available */
2275 	smc_find_rdma_v2_device_serv(new_smc, pclc, ini);
2276 	if (ini->smcrv2.ib_dev_v2)
2277 		return 0;
2278 
2279 	/* check if RDMA V1 is available */
2280 	if (!prfx_rc) {
2281 		int rc;
2282 
2283 		rc = smc_find_rdma_v1_device_serv(new_smc, pclc, ini);
2284 		smc_find_ism_store_rc(rc, ini);
2285 		return (!rc) ? 0 : ini->rc;
2286 	}
2287 	return SMC_CLC_DECL_NOSMCDEV;
2288 }
2289 
2290 /* listen worker: finish RDMA setup */
2291 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
2292 				  struct smc_clc_msg_accept_confirm *cclc,
2293 				  bool local_first,
2294 				  struct smc_init_info *ini)
2295 {
2296 	struct smc_link *link = new_smc->conn.lnk;
2297 	int reason_code = 0;
2298 
2299 	if (local_first)
2300 		smc_link_save_peer_info(link, cclc, ini);
2301 
2302 	if (smc_rmb_rtoken_handling(&new_smc->conn, link, cclc))
2303 		return SMC_CLC_DECL_ERR_RTOK;
2304 
2305 	if (local_first) {
2306 		if (smc_ib_ready_link(link))
2307 			return SMC_CLC_DECL_ERR_RDYLNK;
2308 		/* QP confirmation over RoCE fabric */
2309 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
2310 		reason_code = smcr_serv_conf_first_link(new_smc);
2311 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
2312 	}
2313 	return reason_code;
2314 }
2315 
2316 /* setup for connection of server */
2317 static void smc_listen_work(struct work_struct *work)
2318 {
2319 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
2320 						smc_listen_work);
2321 	struct socket *newclcsock = new_smc->clcsock;
2322 	struct smc_clc_msg_accept_confirm *cclc;
2323 	struct smc_clc_msg_proposal_area *buf;
2324 	struct smc_clc_msg_proposal *pclc;
2325 	struct smc_init_info *ini = NULL;
2326 	u8 proposal_version = SMC_V1;
2327 	u8 accept_version;
2328 	int rc = 0;
2329 
2330 	if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
2331 		return smc_listen_out_err(new_smc);
2332 
2333 	if (new_smc->use_fallback) {
2334 		smc_listen_out_connected(new_smc);
2335 		return;
2336 	}
2337 
2338 	/* check if peer is smc capable */
2339 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
2340 		rc = smc_switch_to_fallback(new_smc, SMC_CLC_DECL_PEERNOSMC);
2341 		if (rc)
2342 			smc_listen_out_err(new_smc);
2343 		else
2344 			smc_listen_out_connected(new_smc);
2345 		return;
2346 	}
2347 
2348 	/* do inband token exchange -
2349 	 * wait for and receive SMC Proposal CLC message
2350 	 */
2351 	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
2352 	if (!buf) {
2353 		rc = SMC_CLC_DECL_MEM;
2354 		goto out_decl;
2355 	}
2356 	pclc = (struct smc_clc_msg_proposal *)buf;
2357 	rc = smc_clc_wait_msg(new_smc, pclc, sizeof(*buf),
2358 			      SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
2359 	if (rc)
2360 		goto out_decl;
2361 
2362 	if (pclc->hdr.version > SMC_V1)
2363 		proposal_version = SMC_V2;
2364 
2365 	/* IPSec connections opt out of SMC optimizations */
2366 	if (using_ipsec(new_smc)) {
2367 		rc = SMC_CLC_DECL_IPSEC;
2368 		goto out_decl;
2369 	}
2370 
2371 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
2372 	if (!ini) {
2373 		rc = SMC_CLC_DECL_MEM;
2374 		goto out_decl;
2375 	}
2376 
2377 	/* initial version checking */
2378 	rc = smc_listen_v2_check(new_smc, pclc, ini);
2379 	if (rc)
2380 		goto out_decl;
2381 
2382 	mutex_lock(&smc_server_lgr_pending);
2383 	smc_close_init(new_smc);
2384 	smc_rx_init(new_smc);
2385 	smc_tx_init(new_smc);
2386 
2387 	/* determine ISM or RoCE device used for connection */
2388 	rc = smc_listen_find_device(new_smc, pclc, ini);
2389 	if (rc)
2390 		goto out_unlock;
2391 
2392 	/* send SMC Accept CLC message */
2393 	accept_version = ini->is_smcd ? ini->smcd_version : ini->smcr_version;
2394 	rc = smc_clc_send_accept(new_smc, ini->first_contact_local,
2395 				 accept_version, ini->negotiated_eid);
2396 	if (rc)
2397 		goto out_unlock;
2398 
2399 	/* SMC-D does not need this lock any more */
2400 	if (ini->is_smcd)
2401 		mutex_unlock(&smc_server_lgr_pending);
2402 
2403 	/* receive SMC Confirm CLC message */
2404 	memset(buf, 0, sizeof(*buf));
2405 	cclc = (struct smc_clc_msg_accept_confirm *)buf;
2406 	rc = smc_clc_wait_msg(new_smc, cclc, sizeof(*buf),
2407 			      SMC_CLC_CONFIRM, CLC_WAIT_TIME);
2408 	if (rc) {
2409 		if (!ini->is_smcd)
2410 			goto out_unlock;
2411 		goto out_decl;
2412 	}
2413 
2414 	/* finish worker */
2415 	if (!ini->is_smcd) {
2416 		rc = smc_listen_rdma_finish(new_smc, cclc,
2417 					    ini->first_contact_local, ini);
2418 		if (rc)
2419 			goto out_unlock;
2420 		mutex_unlock(&smc_server_lgr_pending);
2421 	}
2422 	smc_conn_save_peer_info(new_smc, cclc);
2423 	smc_listen_out_connected(new_smc);
2424 	SMC_STAT_SERV_SUCC_INC(sock_net(newclcsock->sk), ini);
2425 	goto out_free;
2426 
2427 out_unlock:
2428 	mutex_unlock(&smc_server_lgr_pending);
2429 out_decl:
2430 	smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0,
2431 			   proposal_version);
2432 out_free:
2433 	kfree(ini);
2434 	kfree(buf);
2435 }
2436 
2437 static void smc_tcp_listen_work(struct work_struct *work)
2438 {
2439 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
2440 					     tcp_listen_work);
2441 	struct sock *lsk = &lsmc->sk;
2442 	struct smc_sock *new_smc;
2443 	int rc = 0;
2444 
2445 	lock_sock(lsk);
2446 	while (lsk->sk_state == SMC_LISTEN) {
2447 		rc = smc_clcsock_accept(lsmc, &new_smc);
2448 		if (rc) /* clcsock accept queue empty or error */
2449 			goto out;
2450 		if (!new_smc)
2451 			continue;
2452 
2453 		if (tcp_sk(new_smc->clcsock->sk)->syn_smc)
2454 			atomic_inc(&lsmc->queued_smc_hs);
2455 
2456 		new_smc->listen_smc = lsmc;
2457 		new_smc->use_fallback = lsmc->use_fallback;
2458 		new_smc->fallback_rsn = lsmc->fallback_rsn;
2459 		sock_hold(lsk); /* sock_put in smc_listen_work */
2460 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
2461 		smc_copy_sock_settings_to_smc(new_smc);
2462 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
2463 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
2464 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
2465 		if (!queue_work(smc_hs_wq, &new_smc->smc_listen_work))
2466 			sock_put(&new_smc->sk);
2467 	}
2468 
2469 out:
2470 	release_sock(lsk);
2471 	sock_put(&lsmc->sk); /* sock_hold in smc_clcsock_data_ready() */
2472 }
2473 
2474 static void smc_clcsock_data_ready(struct sock *listen_clcsock)
2475 {
2476 	struct smc_sock *lsmc;
2477 
2478 	read_lock_bh(&listen_clcsock->sk_callback_lock);
2479 	lsmc = smc_clcsock_user_data(listen_clcsock);
2480 	if (!lsmc)
2481 		goto out;
2482 	lsmc->clcsk_data_ready(listen_clcsock);
2483 	if (lsmc->sk.sk_state == SMC_LISTEN) {
2484 		sock_hold(&lsmc->sk); /* sock_put in smc_tcp_listen_work() */
2485 		if (!queue_work(smc_tcp_ls_wq, &lsmc->tcp_listen_work))
2486 			sock_put(&lsmc->sk);
2487 	}
2488 out:
2489 	read_unlock_bh(&listen_clcsock->sk_callback_lock);
2490 }
2491 
2492 static int smc_listen(struct socket *sock, int backlog)
2493 {
2494 	struct sock *sk = sock->sk;
2495 	struct smc_sock *smc;
2496 	int rc;
2497 
2498 	smc = smc_sk(sk);
2499 	lock_sock(sk);
2500 
2501 	rc = -EINVAL;
2502 	if ((sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) ||
2503 	    smc->connect_nonblock || sock->state != SS_UNCONNECTED)
2504 		goto out;
2505 
2506 	rc = 0;
2507 	if (sk->sk_state == SMC_LISTEN) {
2508 		sk->sk_max_ack_backlog = backlog;
2509 		goto out;
2510 	}
2511 	/* some socket options are handled in core, so we could not apply
2512 	 * them to the clc socket -- copy smc socket options to clc socket
2513 	 */
2514 	smc_copy_sock_settings_to_clc(smc);
2515 	if (!smc->use_fallback)
2516 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
2517 
2518 	/* save original sk_data_ready function and establish
2519 	 * smc-specific sk_data_ready function
2520 	 */
2521 	write_lock_bh(&smc->clcsock->sk->sk_callback_lock);
2522 	smc->clcsock->sk->sk_user_data =
2523 		(void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
2524 	smc_clcsock_replace_cb(&smc->clcsock->sk->sk_data_ready,
2525 			       smc_clcsock_data_ready, &smc->clcsk_data_ready);
2526 	write_unlock_bh(&smc->clcsock->sk->sk_callback_lock);
2527 
2528 	/* save original ops */
2529 	smc->ori_af_ops = inet_csk(smc->clcsock->sk)->icsk_af_ops;
2530 
2531 	smc->af_ops = *smc->ori_af_ops;
2532 	smc->af_ops.syn_recv_sock = smc_tcp_syn_recv_sock;
2533 
2534 	inet_csk(smc->clcsock->sk)->icsk_af_ops = &smc->af_ops;
2535 
2536 	if (smc->limit_smc_hs)
2537 		tcp_sk(smc->clcsock->sk)->smc_hs_congested = smc_hs_congested;
2538 
2539 	rc = kernel_listen(smc->clcsock, backlog);
2540 	if (rc) {
2541 		write_lock_bh(&smc->clcsock->sk->sk_callback_lock);
2542 		smc_clcsock_restore_cb(&smc->clcsock->sk->sk_data_ready,
2543 				       &smc->clcsk_data_ready);
2544 		smc->clcsock->sk->sk_user_data = NULL;
2545 		write_unlock_bh(&smc->clcsock->sk->sk_callback_lock);
2546 		goto out;
2547 	}
2548 	sk->sk_max_ack_backlog = backlog;
2549 	sk->sk_ack_backlog = 0;
2550 	sk->sk_state = SMC_LISTEN;
2551 
2552 out:
2553 	release_sock(sk);
2554 	return rc;
2555 }
2556 
2557 static int smc_accept(struct socket *sock, struct socket *new_sock,
2558 		      int flags, bool kern)
2559 {
2560 	struct sock *sk = sock->sk, *nsk;
2561 	DECLARE_WAITQUEUE(wait, current);
2562 	struct smc_sock *lsmc;
2563 	long timeo;
2564 	int rc = 0;
2565 
2566 	lsmc = smc_sk(sk);
2567 	sock_hold(sk); /* sock_put below */
2568 	lock_sock(sk);
2569 
2570 	if (lsmc->sk.sk_state != SMC_LISTEN) {
2571 		rc = -EINVAL;
2572 		release_sock(sk);
2573 		goto out;
2574 	}
2575 
2576 	/* Wait for an incoming connection */
2577 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
2578 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
2579 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
2580 		set_current_state(TASK_INTERRUPTIBLE);
2581 		if (!timeo) {
2582 			rc = -EAGAIN;
2583 			break;
2584 		}
2585 		release_sock(sk);
2586 		timeo = schedule_timeout(timeo);
2587 		/* wakeup by sk_data_ready in smc_listen_work() */
2588 		sched_annotate_sleep();
2589 		lock_sock(sk);
2590 		if (signal_pending(current)) {
2591 			rc = sock_intr_errno(timeo);
2592 			break;
2593 		}
2594 	}
2595 	set_current_state(TASK_RUNNING);
2596 	remove_wait_queue(sk_sleep(sk), &wait);
2597 
2598 	if (!rc)
2599 		rc = sock_error(nsk);
2600 	release_sock(sk);
2601 	if (rc)
2602 		goto out;
2603 
2604 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
2605 		/* wait till data arrives on the socket */
2606 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
2607 								MSEC_PER_SEC);
2608 		if (smc_sk(nsk)->use_fallback) {
2609 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
2610 
2611 			lock_sock(clcsk);
2612 			if (skb_queue_empty(&clcsk->sk_receive_queue))
2613 				sk_wait_data(clcsk, &timeo, NULL);
2614 			release_sock(clcsk);
2615 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
2616 			lock_sock(nsk);
2617 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
2618 			release_sock(nsk);
2619 		}
2620 	}
2621 
2622 out:
2623 	sock_put(sk); /* sock_hold above */
2624 	return rc;
2625 }
2626 
2627 static int smc_getname(struct socket *sock, struct sockaddr *addr,
2628 		       int peer)
2629 {
2630 	struct smc_sock *smc;
2631 
2632 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
2633 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
2634 		return -ENOTCONN;
2635 
2636 	smc = smc_sk(sock->sk);
2637 
2638 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
2639 }
2640 
2641 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2642 {
2643 	struct sock *sk = sock->sk;
2644 	struct smc_sock *smc;
2645 	int rc = -EPIPE;
2646 
2647 	smc = smc_sk(sk);
2648 	lock_sock(sk);
2649 	if ((sk->sk_state != SMC_ACTIVE) &&
2650 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2651 	    (sk->sk_state != SMC_INIT))
2652 		goto out;
2653 
2654 	if (msg->msg_flags & MSG_FASTOPEN) {
2655 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2656 			rc = smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2657 			if (rc)
2658 				goto out;
2659 		} else {
2660 			rc = -EINVAL;
2661 			goto out;
2662 		}
2663 	}
2664 
2665 	if (smc->use_fallback) {
2666 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
2667 	} else {
2668 		rc = smc_tx_sendmsg(smc, msg, len);
2669 		SMC_STAT_TX_PAYLOAD(smc, len, rc);
2670 	}
2671 out:
2672 	release_sock(sk);
2673 	return rc;
2674 }
2675 
2676 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2677 		       int flags)
2678 {
2679 	struct sock *sk = sock->sk;
2680 	struct smc_sock *smc;
2681 	int rc = -ENOTCONN;
2682 
2683 	smc = smc_sk(sk);
2684 	lock_sock(sk);
2685 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2686 		/* socket was connected before, no more data to read */
2687 		rc = 0;
2688 		goto out;
2689 	}
2690 	if ((sk->sk_state == SMC_INIT) ||
2691 	    (sk->sk_state == SMC_LISTEN) ||
2692 	    (sk->sk_state == SMC_CLOSED))
2693 		goto out;
2694 
2695 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2696 		rc = 0;
2697 		goto out;
2698 	}
2699 
2700 	if (smc->use_fallback) {
2701 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
2702 	} else {
2703 		msg->msg_namelen = 0;
2704 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
2705 		SMC_STAT_RX_PAYLOAD(smc, rc, rc);
2706 	}
2707 
2708 out:
2709 	release_sock(sk);
2710 	return rc;
2711 }
2712 
2713 static __poll_t smc_accept_poll(struct sock *parent)
2714 {
2715 	struct smc_sock *isk = smc_sk(parent);
2716 	__poll_t mask = 0;
2717 
2718 	spin_lock(&isk->accept_q_lock);
2719 	if (!list_empty(&isk->accept_q))
2720 		mask = EPOLLIN | EPOLLRDNORM;
2721 	spin_unlock(&isk->accept_q_lock);
2722 
2723 	return mask;
2724 }
2725 
2726 static __poll_t smc_poll(struct file *file, struct socket *sock,
2727 			     poll_table *wait)
2728 {
2729 	struct sock *sk = sock->sk;
2730 	struct smc_sock *smc;
2731 	__poll_t mask = 0;
2732 
2733 	if (!sk)
2734 		return EPOLLNVAL;
2735 
2736 	smc = smc_sk(sock->sk);
2737 	if (smc->use_fallback) {
2738 		/* delegate to CLC child sock */
2739 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
2740 		sk->sk_err = smc->clcsock->sk->sk_err;
2741 	} else {
2742 		if (sk->sk_state != SMC_CLOSED)
2743 			sock_poll_wait(file, sock, wait);
2744 		if (sk->sk_err)
2745 			mask |= EPOLLERR;
2746 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
2747 		    (sk->sk_state == SMC_CLOSED))
2748 			mask |= EPOLLHUP;
2749 		if (sk->sk_state == SMC_LISTEN) {
2750 			/* woken up by sk_data_ready in smc_listen_work() */
2751 			mask |= smc_accept_poll(sk);
2752 		} else if (smc->use_fallback) { /* as result of connect_work()*/
2753 			mask |= smc->clcsock->ops->poll(file, smc->clcsock,
2754 							   wait);
2755 			sk->sk_err = smc->clcsock->sk->sk_err;
2756 		} else {
2757 			if ((sk->sk_state != SMC_INIT &&
2758 			     atomic_read(&smc->conn.sndbuf_space)) ||
2759 			    sk->sk_shutdown & SEND_SHUTDOWN) {
2760 				mask |= EPOLLOUT | EPOLLWRNORM;
2761 			} else {
2762 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2763 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2764 			}
2765 			if (atomic_read(&smc->conn.bytes_to_rcv))
2766 				mask |= EPOLLIN | EPOLLRDNORM;
2767 			if (sk->sk_shutdown & RCV_SHUTDOWN)
2768 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
2769 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
2770 				mask |= EPOLLIN;
2771 			if (smc->conn.urg_state == SMC_URG_VALID)
2772 				mask |= EPOLLPRI;
2773 		}
2774 	}
2775 
2776 	return mask;
2777 }
2778 
2779 static int smc_shutdown(struct socket *sock, int how)
2780 {
2781 	struct sock *sk = sock->sk;
2782 	bool do_shutdown = true;
2783 	struct smc_sock *smc;
2784 	int rc = -EINVAL;
2785 	int old_state;
2786 	int rc1 = 0;
2787 
2788 	smc = smc_sk(sk);
2789 
2790 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
2791 		return rc;
2792 
2793 	lock_sock(sk);
2794 
2795 	if (sock->state == SS_CONNECTING) {
2796 		if (sk->sk_state == SMC_ACTIVE)
2797 			sock->state = SS_CONNECTED;
2798 		else if (sk->sk_state == SMC_PEERCLOSEWAIT1 ||
2799 			 sk->sk_state == SMC_PEERCLOSEWAIT2 ||
2800 			 sk->sk_state == SMC_APPCLOSEWAIT1 ||
2801 			 sk->sk_state == SMC_APPCLOSEWAIT2 ||
2802 			 sk->sk_state == SMC_APPFINCLOSEWAIT)
2803 			sock->state = SS_DISCONNECTING;
2804 	}
2805 
2806 	rc = -ENOTCONN;
2807 	if ((sk->sk_state != SMC_ACTIVE) &&
2808 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
2809 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
2810 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2811 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
2812 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
2813 		goto out;
2814 	if (smc->use_fallback) {
2815 		rc = kernel_sock_shutdown(smc->clcsock, how);
2816 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
2817 		if (sk->sk_shutdown == SHUTDOWN_MASK) {
2818 			sk->sk_state = SMC_CLOSED;
2819 			sk->sk_socket->state = SS_UNCONNECTED;
2820 			sock_put(sk);
2821 		}
2822 		goto out;
2823 	}
2824 	switch (how) {
2825 	case SHUT_RDWR:		/* shutdown in both directions */
2826 		old_state = sk->sk_state;
2827 		rc = smc_close_active(smc);
2828 		if (old_state == SMC_ACTIVE &&
2829 		    sk->sk_state == SMC_PEERCLOSEWAIT1)
2830 			do_shutdown = false;
2831 		break;
2832 	case SHUT_WR:
2833 		rc = smc_close_shutdown_write(smc);
2834 		break;
2835 	case SHUT_RD:
2836 		rc = 0;
2837 		/* nothing more to do because peer is not involved */
2838 		break;
2839 	}
2840 	if (do_shutdown && smc->clcsock)
2841 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
2842 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
2843 	sk->sk_shutdown |= how + 1;
2844 
2845 	if (sk->sk_state == SMC_CLOSED)
2846 		sock->state = SS_UNCONNECTED;
2847 	else
2848 		sock->state = SS_DISCONNECTING;
2849 out:
2850 	release_sock(sk);
2851 	return rc ? rc : rc1;
2852 }
2853 
2854 static int __smc_getsockopt(struct socket *sock, int level, int optname,
2855 			    char __user *optval, int __user *optlen)
2856 {
2857 	struct smc_sock *smc;
2858 	int val, len;
2859 
2860 	smc = smc_sk(sock->sk);
2861 
2862 	if (get_user(len, optlen))
2863 		return -EFAULT;
2864 
2865 	len = min_t(int, len, sizeof(int));
2866 
2867 	if (len < 0)
2868 		return -EINVAL;
2869 
2870 	switch (optname) {
2871 	case SMC_LIMIT_HS:
2872 		val = smc->limit_smc_hs;
2873 		break;
2874 	default:
2875 		return -EOPNOTSUPP;
2876 	}
2877 
2878 	if (put_user(len, optlen))
2879 		return -EFAULT;
2880 	if (copy_to_user(optval, &val, len))
2881 		return -EFAULT;
2882 
2883 	return 0;
2884 }
2885 
2886 static int __smc_setsockopt(struct socket *sock, int level, int optname,
2887 			    sockptr_t optval, unsigned int optlen)
2888 {
2889 	struct sock *sk = sock->sk;
2890 	struct smc_sock *smc;
2891 	int val, rc;
2892 
2893 	smc = smc_sk(sk);
2894 
2895 	lock_sock(sk);
2896 	switch (optname) {
2897 	case SMC_LIMIT_HS:
2898 		if (optlen < sizeof(int)) {
2899 			rc = -EINVAL;
2900 			break;
2901 		}
2902 		if (copy_from_sockptr(&val, optval, sizeof(int))) {
2903 			rc = -EFAULT;
2904 			break;
2905 		}
2906 
2907 		smc->limit_smc_hs = !!val;
2908 		rc = 0;
2909 		break;
2910 	default:
2911 		rc = -EOPNOTSUPP;
2912 		break;
2913 	}
2914 	release_sock(sk);
2915 
2916 	return rc;
2917 }
2918 
2919 static int smc_setsockopt(struct socket *sock, int level, int optname,
2920 			  sockptr_t optval, unsigned int optlen)
2921 {
2922 	struct sock *sk = sock->sk;
2923 	struct smc_sock *smc;
2924 	int val, rc;
2925 
2926 	if (level == SOL_TCP && optname == TCP_ULP)
2927 		return -EOPNOTSUPP;
2928 	else if (level == SOL_SMC)
2929 		return __smc_setsockopt(sock, level, optname, optval, optlen);
2930 
2931 	smc = smc_sk(sk);
2932 
2933 	/* generic setsockopts reaching us here always apply to the
2934 	 * CLC socket
2935 	 */
2936 	mutex_lock(&smc->clcsock_release_lock);
2937 	if (!smc->clcsock) {
2938 		mutex_unlock(&smc->clcsock_release_lock);
2939 		return -EBADF;
2940 	}
2941 	if (unlikely(!smc->clcsock->ops->setsockopt))
2942 		rc = -EOPNOTSUPP;
2943 	else
2944 		rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
2945 						   optval, optlen);
2946 	if (smc->clcsock->sk->sk_err) {
2947 		sk->sk_err = smc->clcsock->sk->sk_err;
2948 		sk_error_report(sk);
2949 	}
2950 	mutex_unlock(&smc->clcsock_release_lock);
2951 
2952 	if (optlen < sizeof(int))
2953 		return -EINVAL;
2954 	if (copy_from_sockptr(&val, optval, sizeof(int)))
2955 		return -EFAULT;
2956 
2957 	lock_sock(sk);
2958 	if (rc || smc->use_fallback)
2959 		goto out;
2960 	switch (optname) {
2961 	case TCP_FASTOPEN:
2962 	case TCP_FASTOPEN_CONNECT:
2963 	case TCP_FASTOPEN_KEY:
2964 	case TCP_FASTOPEN_NO_COOKIE:
2965 		/* option not supported by SMC */
2966 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2967 			rc = smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2968 		} else {
2969 			rc = -EINVAL;
2970 		}
2971 		break;
2972 	case TCP_NODELAY:
2973 		if (sk->sk_state != SMC_INIT &&
2974 		    sk->sk_state != SMC_LISTEN &&
2975 		    sk->sk_state != SMC_CLOSED) {
2976 			if (val) {
2977 				SMC_STAT_INC(smc, ndly_cnt);
2978 				smc_tx_pending(&smc->conn);
2979 				cancel_delayed_work(&smc->conn.tx_work);
2980 			}
2981 		}
2982 		break;
2983 	case TCP_CORK:
2984 		if (sk->sk_state != SMC_INIT &&
2985 		    sk->sk_state != SMC_LISTEN &&
2986 		    sk->sk_state != SMC_CLOSED) {
2987 			if (!val) {
2988 				SMC_STAT_INC(smc, cork_cnt);
2989 				smc_tx_pending(&smc->conn);
2990 				cancel_delayed_work(&smc->conn.tx_work);
2991 			}
2992 		}
2993 		break;
2994 	case TCP_DEFER_ACCEPT:
2995 		smc->sockopt_defer_accept = val;
2996 		break;
2997 	default:
2998 		break;
2999 	}
3000 out:
3001 	release_sock(sk);
3002 
3003 	return rc;
3004 }
3005 
3006 static int smc_getsockopt(struct socket *sock, int level, int optname,
3007 			  char __user *optval, int __user *optlen)
3008 {
3009 	struct smc_sock *smc;
3010 	int rc;
3011 
3012 	if (level == SOL_SMC)
3013 		return __smc_getsockopt(sock, level, optname, optval, optlen);
3014 
3015 	smc = smc_sk(sock->sk);
3016 	mutex_lock(&smc->clcsock_release_lock);
3017 	if (!smc->clcsock) {
3018 		mutex_unlock(&smc->clcsock_release_lock);
3019 		return -EBADF;
3020 	}
3021 	/* socket options apply to the CLC socket */
3022 	if (unlikely(!smc->clcsock->ops->getsockopt)) {
3023 		mutex_unlock(&smc->clcsock_release_lock);
3024 		return -EOPNOTSUPP;
3025 	}
3026 	rc = smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
3027 					   optval, optlen);
3028 	mutex_unlock(&smc->clcsock_release_lock);
3029 	return rc;
3030 }
3031 
3032 static int smc_ioctl(struct socket *sock, unsigned int cmd,
3033 		     unsigned long arg)
3034 {
3035 	union smc_host_cursor cons, urg;
3036 	struct smc_connection *conn;
3037 	struct smc_sock *smc;
3038 	int answ;
3039 
3040 	smc = smc_sk(sock->sk);
3041 	conn = &smc->conn;
3042 	lock_sock(&smc->sk);
3043 	if (smc->use_fallback) {
3044 		if (!smc->clcsock) {
3045 			release_sock(&smc->sk);
3046 			return -EBADF;
3047 		}
3048 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
3049 		release_sock(&smc->sk);
3050 		return answ;
3051 	}
3052 	switch (cmd) {
3053 	case SIOCINQ: /* same as FIONREAD */
3054 		if (smc->sk.sk_state == SMC_LISTEN) {
3055 			release_sock(&smc->sk);
3056 			return -EINVAL;
3057 		}
3058 		if (smc->sk.sk_state == SMC_INIT ||
3059 		    smc->sk.sk_state == SMC_CLOSED)
3060 			answ = 0;
3061 		else
3062 			answ = atomic_read(&smc->conn.bytes_to_rcv);
3063 		break;
3064 	case SIOCOUTQ:
3065 		/* output queue size (not send + not acked) */
3066 		if (smc->sk.sk_state == SMC_LISTEN) {
3067 			release_sock(&smc->sk);
3068 			return -EINVAL;
3069 		}
3070 		if (smc->sk.sk_state == SMC_INIT ||
3071 		    smc->sk.sk_state == SMC_CLOSED)
3072 			answ = 0;
3073 		else
3074 			answ = smc->conn.sndbuf_desc->len -
3075 					atomic_read(&smc->conn.sndbuf_space);
3076 		break;
3077 	case SIOCOUTQNSD:
3078 		/* output queue size (not send only) */
3079 		if (smc->sk.sk_state == SMC_LISTEN) {
3080 			release_sock(&smc->sk);
3081 			return -EINVAL;
3082 		}
3083 		if (smc->sk.sk_state == SMC_INIT ||
3084 		    smc->sk.sk_state == SMC_CLOSED)
3085 			answ = 0;
3086 		else
3087 			answ = smc_tx_prepared_sends(&smc->conn);
3088 		break;
3089 	case SIOCATMARK:
3090 		if (smc->sk.sk_state == SMC_LISTEN) {
3091 			release_sock(&smc->sk);
3092 			return -EINVAL;
3093 		}
3094 		if (smc->sk.sk_state == SMC_INIT ||
3095 		    smc->sk.sk_state == SMC_CLOSED) {
3096 			answ = 0;
3097 		} else {
3098 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
3099 			smc_curs_copy(&urg, &conn->urg_curs, conn);
3100 			answ = smc_curs_diff(conn->rmb_desc->len,
3101 					     &cons, &urg) == 1;
3102 		}
3103 		break;
3104 	default:
3105 		release_sock(&smc->sk);
3106 		return -ENOIOCTLCMD;
3107 	}
3108 	release_sock(&smc->sk);
3109 
3110 	return put_user(answ, (int __user *)arg);
3111 }
3112 
3113 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
3114 			    int offset, size_t size, int flags)
3115 {
3116 	struct sock *sk = sock->sk;
3117 	struct smc_sock *smc;
3118 	int rc = -EPIPE;
3119 
3120 	smc = smc_sk(sk);
3121 	lock_sock(sk);
3122 	if (sk->sk_state != SMC_ACTIVE) {
3123 		release_sock(sk);
3124 		goto out;
3125 	}
3126 	release_sock(sk);
3127 	if (smc->use_fallback) {
3128 		rc = kernel_sendpage(smc->clcsock, page, offset,
3129 				     size, flags);
3130 	} else {
3131 		lock_sock(sk);
3132 		rc = smc_tx_sendpage(smc, page, offset, size, flags);
3133 		release_sock(sk);
3134 		SMC_STAT_INC(smc, sendpage_cnt);
3135 	}
3136 
3137 out:
3138 	return rc;
3139 }
3140 
3141 /* Map the affected portions of the rmbe into an spd, note the number of bytes
3142  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
3143  * updates till whenever a respective page has been fully processed.
3144  * Note that subsequent recv() calls have to wait till all splice() processing
3145  * completed.
3146  */
3147 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
3148 			       struct pipe_inode_info *pipe, size_t len,
3149 			       unsigned int flags)
3150 {
3151 	struct sock *sk = sock->sk;
3152 	struct smc_sock *smc;
3153 	int rc = -ENOTCONN;
3154 
3155 	smc = smc_sk(sk);
3156 	lock_sock(sk);
3157 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
3158 		/* socket was connected before, no more data to read */
3159 		rc = 0;
3160 		goto out;
3161 	}
3162 	if (sk->sk_state == SMC_INIT ||
3163 	    sk->sk_state == SMC_LISTEN ||
3164 	    sk->sk_state == SMC_CLOSED)
3165 		goto out;
3166 
3167 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
3168 		rc = 0;
3169 		goto out;
3170 	}
3171 
3172 	if (smc->use_fallback) {
3173 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
3174 						    pipe, len, flags);
3175 	} else {
3176 		if (*ppos) {
3177 			rc = -ESPIPE;
3178 			goto out;
3179 		}
3180 		if (flags & SPLICE_F_NONBLOCK)
3181 			flags = MSG_DONTWAIT;
3182 		else
3183 			flags = 0;
3184 		SMC_STAT_INC(smc, splice_cnt);
3185 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
3186 	}
3187 out:
3188 	release_sock(sk);
3189 
3190 	return rc;
3191 }
3192 
3193 /* must look like tcp */
3194 static const struct proto_ops smc_sock_ops = {
3195 	.family		= PF_SMC,
3196 	.owner		= THIS_MODULE,
3197 	.release	= smc_release,
3198 	.bind		= smc_bind,
3199 	.connect	= smc_connect,
3200 	.socketpair	= sock_no_socketpair,
3201 	.accept		= smc_accept,
3202 	.getname	= smc_getname,
3203 	.poll		= smc_poll,
3204 	.ioctl		= smc_ioctl,
3205 	.listen		= smc_listen,
3206 	.shutdown	= smc_shutdown,
3207 	.setsockopt	= smc_setsockopt,
3208 	.getsockopt	= smc_getsockopt,
3209 	.sendmsg	= smc_sendmsg,
3210 	.recvmsg	= smc_recvmsg,
3211 	.mmap		= sock_no_mmap,
3212 	.sendpage	= smc_sendpage,
3213 	.splice_read	= smc_splice_read,
3214 };
3215 
3216 static int __smc_create(struct net *net, struct socket *sock, int protocol,
3217 			int kern, struct socket *clcsock)
3218 {
3219 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
3220 	struct smc_sock *smc;
3221 	struct sock *sk;
3222 	int rc;
3223 
3224 	rc = -ESOCKTNOSUPPORT;
3225 	if (sock->type != SOCK_STREAM)
3226 		goto out;
3227 
3228 	rc = -EPROTONOSUPPORT;
3229 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
3230 		goto out;
3231 
3232 	rc = -ENOBUFS;
3233 	sock->ops = &smc_sock_ops;
3234 	sock->state = SS_UNCONNECTED;
3235 	sk = smc_sock_alloc(net, sock, protocol);
3236 	if (!sk)
3237 		goto out;
3238 
3239 	/* create internal TCP socket for CLC handshake and fallback */
3240 	smc = smc_sk(sk);
3241 	smc->use_fallback = false; /* assume rdma capability first */
3242 	smc->fallback_rsn = 0;
3243 
3244 	/* default behavior from limit_smc_hs in every net namespace */
3245 	smc->limit_smc_hs = net->smc.limit_smc_hs;
3246 
3247 	rc = 0;
3248 	if (!clcsock) {
3249 		rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
3250 				      &smc->clcsock);
3251 		if (rc) {
3252 			sk_common_release(sk);
3253 			goto out;
3254 		}
3255 	} else {
3256 		smc->clcsock = clcsock;
3257 	}
3258 
3259 out:
3260 	return rc;
3261 }
3262 
3263 static int smc_create(struct net *net, struct socket *sock, int protocol,
3264 		      int kern)
3265 {
3266 	return __smc_create(net, sock, protocol, kern, NULL);
3267 }
3268 
3269 static const struct net_proto_family smc_sock_family_ops = {
3270 	.family	= PF_SMC,
3271 	.owner	= THIS_MODULE,
3272 	.create	= smc_create,
3273 };
3274 
3275 static int smc_ulp_init(struct sock *sk)
3276 {
3277 	struct socket *tcp = sk->sk_socket;
3278 	struct net *net = sock_net(sk);
3279 	struct socket *smcsock;
3280 	int protocol, ret;
3281 
3282 	/* only TCP can be replaced */
3283 	if (tcp->type != SOCK_STREAM || sk->sk_protocol != IPPROTO_TCP ||
3284 	    (sk->sk_family != AF_INET && sk->sk_family != AF_INET6))
3285 		return -ESOCKTNOSUPPORT;
3286 	/* don't handle wq now */
3287 	if (tcp->state != SS_UNCONNECTED || !tcp->file || tcp->wq.fasync_list)
3288 		return -ENOTCONN;
3289 
3290 	if (sk->sk_family == AF_INET)
3291 		protocol = SMCPROTO_SMC;
3292 	else
3293 		protocol = SMCPROTO_SMC6;
3294 
3295 	smcsock = sock_alloc();
3296 	if (!smcsock)
3297 		return -ENFILE;
3298 
3299 	smcsock->type = SOCK_STREAM;
3300 	__module_get(THIS_MODULE); /* tried in __tcp_ulp_find_autoload */
3301 	ret = __smc_create(net, smcsock, protocol, 1, tcp);
3302 	if (ret) {
3303 		sock_release(smcsock); /* module_put() which ops won't be NULL */
3304 		return ret;
3305 	}
3306 
3307 	/* replace tcp socket to smc */
3308 	smcsock->file = tcp->file;
3309 	smcsock->file->private_data = smcsock;
3310 	smcsock->file->f_inode = SOCK_INODE(smcsock); /* replace inode when sock_close */
3311 	smcsock->file->f_path.dentry->d_inode = SOCK_INODE(smcsock); /* dput() in __fput */
3312 	tcp->file = NULL;
3313 
3314 	return ret;
3315 }
3316 
3317 static void smc_ulp_clone(const struct request_sock *req, struct sock *newsk,
3318 			  const gfp_t priority)
3319 {
3320 	struct inet_connection_sock *icsk = inet_csk(newsk);
3321 
3322 	/* don't inherit ulp ops to child when listen */
3323 	icsk->icsk_ulp_ops = NULL;
3324 }
3325 
3326 static struct tcp_ulp_ops smc_ulp_ops __read_mostly = {
3327 	.name		= "smc",
3328 	.owner		= THIS_MODULE,
3329 	.init		= smc_ulp_init,
3330 	.clone		= smc_ulp_clone,
3331 };
3332 
3333 unsigned int smc_net_id;
3334 
3335 static __net_init int smc_net_init(struct net *net)
3336 {
3337 	int rc;
3338 
3339 	rc = smc_sysctl_net_init(net);
3340 	if (rc)
3341 		return rc;
3342 	return smc_pnet_net_init(net);
3343 }
3344 
3345 static void __net_exit smc_net_exit(struct net *net)
3346 {
3347 	smc_sysctl_net_exit(net);
3348 	smc_pnet_net_exit(net);
3349 }
3350 
3351 static __net_init int smc_net_stat_init(struct net *net)
3352 {
3353 	return smc_stats_init(net);
3354 }
3355 
3356 static void __net_exit smc_net_stat_exit(struct net *net)
3357 {
3358 	smc_stats_exit(net);
3359 }
3360 
3361 static struct pernet_operations smc_net_ops = {
3362 	.init = smc_net_init,
3363 	.exit = smc_net_exit,
3364 	.id   = &smc_net_id,
3365 	.size = sizeof(struct smc_net),
3366 };
3367 
3368 static struct pernet_operations smc_net_stat_ops = {
3369 	.init = smc_net_stat_init,
3370 	.exit = smc_net_stat_exit,
3371 };
3372 
3373 static int __init smc_init(void)
3374 {
3375 	int rc;
3376 
3377 	rc = register_pernet_subsys(&smc_net_ops);
3378 	if (rc)
3379 		return rc;
3380 
3381 	rc = register_pernet_subsys(&smc_net_stat_ops);
3382 	if (rc)
3383 		goto out_pernet_subsys;
3384 
3385 	smc_ism_init();
3386 	smc_clc_init();
3387 
3388 	rc = smc_nl_init();
3389 	if (rc)
3390 		goto out_pernet_subsys_stat;
3391 
3392 	rc = smc_pnet_init();
3393 	if (rc)
3394 		goto out_nl;
3395 
3396 	rc = -ENOMEM;
3397 
3398 	smc_tcp_ls_wq = alloc_workqueue("smc_tcp_ls_wq", 0, 0);
3399 	if (!smc_tcp_ls_wq)
3400 		goto out_pnet;
3401 
3402 	smc_hs_wq = alloc_workqueue("smc_hs_wq", 0, 0);
3403 	if (!smc_hs_wq)
3404 		goto out_alloc_tcp_ls_wq;
3405 
3406 	smc_close_wq = alloc_workqueue("smc_close_wq", 0, 0);
3407 	if (!smc_close_wq)
3408 		goto out_alloc_hs_wq;
3409 
3410 	rc = smc_core_init();
3411 	if (rc) {
3412 		pr_err("%s: smc_core_init fails with %d\n", __func__, rc);
3413 		goto out_alloc_wqs;
3414 	}
3415 
3416 	rc = smc_llc_init();
3417 	if (rc) {
3418 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
3419 		goto out_core;
3420 	}
3421 
3422 	rc = smc_cdc_init();
3423 	if (rc) {
3424 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
3425 		goto out_core;
3426 	}
3427 
3428 	rc = proto_register(&smc_proto, 1);
3429 	if (rc) {
3430 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
3431 		goto out_core;
3432 	}
3433 
3434 	rc = proto_register(&smc_proto6, 1);
3435 	if (rc) {
3436 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
3437 		goto out_proto;
3438 	}
3439 
3440 	rc = sock_register(&smc_sock_family_ops);
3441 	if (rc) {
3442 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
3443 		goto out_proto6;
3444 	}
3445 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
3446 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
3447 
3448 	rc = smc_ib_register_client();
3449 	if (rc) {
3450 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
3451 		goto out_sock;
3452 	}
3453 
3454 	rc = tcp_register_ulp(&smc_ulp_ops);
3455 	if (rc) {
3456 		pr_err("%s: tcp_ulp_register fails with %d\n", __func__, rc);
3457 		goto out_ib;
3458 	}
3459 
3460 	static_branch_enable(&tcp_have_smc);
3461 	return 0;
3462 
3463 out_ib:
3464 	smc_ib_unregister_client();
3465 out_sock:
3466 	sock_unregister(PF_SMC);
3467 out_proto6:
3468 	proto_unregister(&smc_proto6);
3469 out_proto:
3470 	proto_unregister(&smc_proto);
3471 out_core:
3472 	smc_core_exit();
3473 out_alloc_wqs:
3474 	destroy_workqueue(smc_close_wq);
3475 out_alloc_hs_wq:
3476 	destroy_workqueue(smc_hs_wq);
3477 out_alloc_tcp_ls_wq:
3478 	destroy_workqueue(smc_tcp_ls_wq);
3479 out_pnet:
3480 	smc_pnet_exit();
3481 out_nl:
3482 	smc_nl_exit();
3483 out_pernet_subsys_stat:
3484 	unregister_pernet_subsys(&smc_net_stat_ops);
3485 out_pernet_subsys:
3486 	unregister_pernet_subsys(&smc_net_ops);
3487 
3488 	return rc;
3489 }
3490 
3491 static void __exit smc_exit(void)
3492 {
3493 	static_branch_disable(&tcp_have_smc);
3494 	tcp_unregister_ulp(&smc_ulp_ops);
3495 	sock_unregister(PF_SMC);
3496 	smc_core_exit();
3497 	smc_ib_unregister_client();
3498 	destroy_workqueue(smc_close_wq);
3499 	destroy_workqueue(smc_tcp_ls_wq);
3500 	destroy_workqueue(smc_hs_wq);
3501 	proto_unregister(&smc_proto6);
3502 	proto_unregister(&smc_proto);
3503 	smc_pnet_exit();
3504 	smc_nl_exit();
3505 	smc_clc_exit();
3506 	unregister_pernet_subsys(&smc_net_stat_ops);
3507 	unregister_pernet_subsys(&smc_net_ops);
3508 	rcu_barrier();
3509 }
3510 
3511 module_init(smc_init);
3512 module_exit(smc_exit);
3513 
3514 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
3515 MODULE_DESCRIPTION("smc socket address family");
3516 MODULE_LICENSE("GPL");
3517 MODULE_ALIAS_NETPROTO(PF_SMC);
3518 MODULE_ALIAS_TCP_ULP("smc");
3519 MODULE_ALIAS_GENL_FAMILY(SMC_GENL_FAMILY_NAME);
3520