xref: /linux/net/smc/af_smc.c (revision 6eed756408c69687613a83fd221431c8790cf0bb)
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 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
433 
434 out_rel:
435 	release_sock(sk);
436 out:
437 	return rc;
438 }
439 
440 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
441 				   unsigned long mask)
442 {
443 	/* options we don't get control via setsockopt for */
444 	nsk->sk_type = osk->sk_type;
445 	nsk->sk_sndbuf = osk->sk_sndbuf;
446 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
447 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
448 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
449 	nsk->sk_mark = osk->sk_mark;
450 	nsk->sk_priority = osk->sk_priority;
451 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
452 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
453 	nsk->sk_err = osk->sk_err;
454 
455 	nsk->sk_flags &= ~mask;
456 	nsk->sk_flags |= osk->sk_flags & mask;
457 }
458 
459 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
460 			     (1UL << SOCK_KEEPOPEN) | \
461 			     (1UL << SOCK_LINGER) | \
462 			     (1UL << SOCK_BROADCAST) | \
463 			     (1UL << SOCK_TIMESTAMP) | \
464 			     (1UL << SOCK_DBG) | \
465 			     (1UL << SOCK_RCVTSTAMP) | \
466 			     (1UL << SOCK_RCVTSTAMPNS) | \
467 			     (1UL << SOCK_LOCALROUTE) | \
468 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
469 			     (1UL << SOCK_RXQ_OVFL) | \
470 			     (1UL << SOCK_WIFI_STATUS) | \
471 			     (1UL << SOCK_NOFCS) | \
472 			     (1UL << SOCK_FILTER_LOCKED) | \
473 			     (1UL << SOCK_TSTAMP_NEW))
474 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
475  * clc socket (since smc is not called for these options from net/core)
476  */
477 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
478 {
479 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
480 }
481 
482 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
483 			     (1UL << SOCK_KEEPOPEN) | \
484 			     (1UL << SOCK_LINGER) | \
485 			     (1UL << SOCK_DBG))
486 /* copy only settings and flags relevant for smc from clc to smc socket */
487 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
488 {
489 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
490 }
491 
492 /* register the new vzalloced sndbuf on all links */
493 static int smcr_lgr_reg_sndbufs(struct smc_link *link,
494 				struct smc_buf_desc *snd_desc)
495 {
496 	struct smc_link_group *lgr = link->lgr;
497 	int i, rc = 0;
498 
499 	if (!snd_desc->is_vm)
500 		return -EINVAL;
501 
502 	/* protect against parallel smcr_link_reg_buf() */
503 	mutex_lock(&lgr->llc_conf_mutex);
504 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
505 		if (!smc_link_active(&lgr->lnk[i]))
506 			continue;
507 		rc = smcr_link_reg_buf(&lgr->lnk[i], snd_desc);
508 		if (rc)
509 			break;
510 	}
511 	mutex_unlock(&lgr->llc_conf_mutex);
512 	return rc;
513 }
514 
515 /* register the new rmb on all links */
516 static int smcr_lgr_reg_rmbs(struct smc_link *link,
517 			     struct smc_buf_desc *rmb_desc)
518 {
519 	struct smc_link_group *lgr = link->lgr;
520 	int i, rc = 0;
521 
522 	rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
523 	if (rc)
524 		return rc;
525 	/* protect against parallel smc_llc_cli_rkey_exchange() and
526 	 * parallel smcr_link_reg_buf()
527 	 */
528 	mutex_lock(&lgr->llc_conf_mutex);
529 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
530 		if (!smc_link_active(&lgr->lnk[i]))
531 			continue;
532 		rc = smcr_link_reg_buf(&lgr->lnk[i], rmb_desc);
533 		if (rc)
534 			goto out;
535 	}
536 
537 	/* exchange confirm_rkey msg with peer */
538 	rc = smc_llc_do_confirm_rkey(link, rmb_desc);
539 	if (rc) {
540 		rc = -EFAULT;
541 		goto out;
542 	}
543 	rmb_desc->is_conf_rkey = true;
544 out:
545 	mutex_unlock(&lgr->llc_conf_mutex);
546 	smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
547 	return rc;
548 }
549 
550 static int smcr_clnt_conf_first_link(struct smc_sock *smc)
551 {
552 	struct smc_link *link = smc->conn.lnk;
553 	struct smc_llc_qentry *qentry;
554 	int rc;
555 
556 	/* receive CONFIRM LINK request from server over RoCE fabric */
557 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
558 			      SMC_LLC_CONFIRM_LINK);
559 	if (!qentry) {
560 		struct smc_clc_msg_decline dclc;
561 
562 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
563 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
564 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
565 	}
566 	smc_llc_save_peer_uid(qentry);
567 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_REQ);
568 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
569 	if (rc)
570 		return SMC_CLC_DECL_RMBE_EC;
571 
572 	rc = smc_ib_modify_qp_rts(link);
573 	if (rc)
574 		return SMC_CLC_DECL_ERR_RDYLNK;
575 
576 	smc_wr_remember_qp_attr(link);
577 
578 	/* reg the sndbuf if it was vzalloced */
579 	if (smc->conn.sndbuf_desc->is_vm) {
580 		if (smcr_link_reg_buf(link, smc->conn.sndbuf_desc))
581 			return SMC_CLC_DECL_ERR_REGBUF;
582 	}
583 
584 	/* reg the rmb */
585 	if (smcr_link_reg_buf(link, smc->conn.rmb_desc))
586 		return SMC_CLC_DECL_ERR_REGBUF;
587 
588 	/* confirm_rkey is implicit on 1st contact */
589 	smc->conn.rmb_desc->is_conf_rkey = true;
590 
591 	/* send CONFIRM LINK response over RoCE fabric */
592 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
593 	if (rc < 0)
594 		return SMC_CLC_DECL_TIMEOUT_CL;
595 
596 	smc_llc_link_active(link);
597 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
598 
599 	/* optional 2nd link, receive ADD LINK request from server */
600 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
601 			      SMC_LLC_ADD_LINK);
602 	if (!qentry) {
603 		struct smc_clc_msg_decline dclc;
604 
605 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
606 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
607 		if (rc == -EAGAIN)
608 			rc = 0; /* no DECLINE received, go with one link */
609 		return rc;
610 	}
611 	smc_llc_flow_qentry_clr(&link->lgr->llc_flow_lcl);
612 	smc_llc_cli_add_link(link, qentry);
613 	return 0;
614 }
615 
616 static bool smc_isascii(char *hostname)
617 {
618 	int i;
619 
620 	for (i = 0; i < SMC_MAX_HOSTNAME_LEN; i++)
621 		if (!isascii(hostname[i]))
622 			return false;
623 	return true;
624 }
625 
626 static void smc_conn_save_peer_info_fce(struct smc_sock *smc,
627 					struct smc_clc_msg_accept_confirm *clc)
628 {
629 	struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
630 		(struct smc_clc_msg_accept_confirm_v2 *)clc;
631 	struct smc_clc_first_contact_ext *fce;
632 	int clc_v2_len;
633 
634 	if (clc->hdr.version == SMC_V1 ||
635 	    !(clc->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
636 		return;
637 
638 	if (smc->conn.lgr->is_smcd) {
639 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->d1.eid,
640 		       SMC_MAX_EID_LEN);
641 		clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
642 					 d1);
643 	} else {
644 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->r1.eid,
645 		       SMC_MAX_EID_LEN);
646 		clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
647 					 r1);
648 	}
649 	fce = (struct smc_clc_first_contact_ext *)(((u8 *)clc_v2) + clc_v2_len);
650 	smc->conn.lgr->peer_os = fce->os_type;
651 	smc->conn.lgr->peer_smc_release = fce->release;
652 	if (smc_isascii(fce->hostname))
653 		memcpy(smc->conn.lgr->peer_hostname, fce->hostname,
654 		       SMC_MAX_HOSTNAME_LEN);
655 }
656 
657 static void smcr_conn_save_peer_info(struct smc_sock *smc,
658 				     struct smc_clc_msg_accept_confirm *clc)
659 {
660 	int bufsize = smc_uncompress_bufsize(clc->r0.rmbe_size);
661 
662 	smc->conn.peer_rmbe_idx = clc->r0.rmbe_idx;
663 	smc->conn.local_tx_ctrl.token = ntohl(clc->r0.rmbe_alert_token);
664 	smc->conn.peer_rmbe_size = bufsize;
665 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
666 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
667 }
668 
669 static void smcd_conn_save_peer_info(struct smc_sock *smc,
670 				     struct smc_clc_msg_accept_confirm *clc)
671 {
672 	int bufsize = smc_uncompress_bufsize(clc->d0.dmbe_size);
673 
674 	smc->conn.peer_rmbe_idx = clc->d0.dmbe_idx;
675 	smc->conn.peer_token = clc->d0.token;
676 	/* msg header takes up space in the buffer */
677 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
678 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
679 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
680 }
681 
682 static void smc_conn_save_peer_info(struct smc_sock *smc,
683 				    struct smc_clc_msg_accept_confirm *clc)
684 {
685 	if (smc->conn.lgr->is_smcd)
686 		smcd_conn_save_peer_info(smc, clc);
687 	else
688 		smcr_conn_save_peer_info(smc, clc);
689 	smc_conn_save_peer_info_fce(smc, clc);
690 }
691 
692 static void smc_link_save_peer_info(struct smc_link *link,
693 				    struct smc_clc_msg_accept_confirm *clc,
694 				    struct smc_init_info *ini)
695 {
696 	link->peer_qpn = ntoh24(clc->r0.qpn);
697 	memcpy(link->peer_gid, ini->peer_gid, SMC_GID_SIZE);
698 	memcpy(link->peer_mac, ini->peer_mac, sizeof(link->peer_mac));
699 	link->peer_psn = ntoh24(clc->r0.psn);
700 	link->peer_mtu = clc->r0.qp_mtu;
701 }
702 
703 static void smc_stat_inc_fback_rsn_cnt(struct smc_sock *smc,
704 				       struct smc_stats_fback *fback_arr)
705 {
706 	int cnt;
707 
708 	for (cnt = 0; cnt < SMC_MAX_FBACK_RSN_CNT; cnt++) {
709 		if (fback_arr[cnt].fback_code == smc->fallback_rsn) {
710 			fback_arr[cnt].count++;
711 			break;
712 		}
713 		if (!fback_arr[cnt].fback_code) {
714 			fback_arr[cnt].fback_code = smc->fallback_rsn;
715 			fback_arr[cnt].count++;
716 			break;
717 		}
718 	}
719 }
720 
721 static void smc_stat_fallback(struct smc_sock *smc)
722 {
723 	struct net *net = sock_net(&smc->sk);
724 
725 	mutex_lock(&net->smc.mutex_fback_rsn);
726 	if (smc->listen_smc) {
727 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->srv);
728 		net->smc.fback_rsn->srv_fback_cnt++;
729 	} else {
730 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->clnt);
731 		net->smc.fback_rsn->clnt_fback_cnt++;
732 	}
733 	mutex_unlock(&net->smc.mutex_fback_rsn);
734 }
735 
736 /* must be called under rcu read lock */
737 static void smc_fback_wakeup_waitqueue(struct smc_sock *smc, void *key)
738 {
739 	struct socket_wq *wq;
740 	__poll_t flags;
741 
742 	wq = rcu_dereference(smc->sk.sk_wq);
743 	if (!skwq_has_sleeper(wq))
744 		return;
745 
746 	/* wake up smc sk->sk_wq */
747 	if (!key) {
748 		/* sk_state_change */
749 		wake_up_interruptible_all(&wq->wait);
750 	} else {
751 		flags = key_to_poll(key);
752 		if (flags & (EPOLLIN | EPOLLOUT))
753 			/* sk_data_ready or sk_write_space */
754 			wake_up_interruptible_sync_poll(&wq->wait, flags);
755 		else if (flags & EPOLLERR)
756 			/* sk_error_report */
757 			wake_up_interruptible_poll(&wq->wait, flags);
758 	}
759 }
760 
761 static int smc_fback_mark_woken(wait_queue_entry_t *wait,
762 				unsigned int mode, int sync, void *key)
763 {
764 	struct smc_mark_woken *mark =
765 		container_of(wait, struct smc_mark_woken, wait_entry);
766 
767 	mark->woken = true;
768 	mark->key = key;
769 	return 0;
770 }
771 
772 static void smc_fback_forward_wakeup(struct smc_sock *smc, struct sock *clcsk,
773 				     void (*clcsock_callback)(struct sock *sk))
774 {
775 	struct smc_mark_woken mark = { .woken = false };
776 	struct socket_wq *wq;
777 
778 	init_waitqueue_func_entry(&mark.wait_entry,
779 				  smc_fback_mark_woken);
780 	rcu_read_lock();
781 	wq = rcu_dereference(clcsk->sk_wq);
782 	if (!wq)
783 		goto out;
784 	add_wait_queue(sk_sleep(clcsk), &mark.wait_entry);
785 	clcsock_callback(clcsk);
786 	remove_wait_queue(sk_sleep(clcsk), &mark.wait_entry);
787 
788 	if (mark.woken)
789 		smc_fback_wakeup_waitqueue(smc, mark.key);
790 out:
791 	rcu_read_unlock();
792 }
793 
794 static void smc_fback_state_change(struct sock *clcsk)
795 {
796 	struct smc_sock *smc;
797 
798 	read_lock_bh(&clcsk->sk_callback_lock);
799 	smc = smc_clcsock_user_data(clcsk);
800 	if (smc)
801 		smc_fback_forward_wakeup(smc, clcsk,
802 					 smc->clcsk_state_change);
803 	read_unlock_bh(&clcsk->sk_callback_lock);
804 }
805 
806 static void smc_fback_data_ready(struct sock *clcsk)
807 {
808 	struct smc_sock *smc;
809 
810 	read_lock_bh(&clcsk->sk_callback_lock);
811 	smc = smc_clcsock_user_data(clcsk);
812 	if (smc)
813 		smc_fback_forward_wakeup(smc, clcsk,
814 					 smc->clcsk_data_ready);
815 	read_unlock_bh(&clcsk->sk_callback_lock);
816 }
817 
818 static void smc_fback_write_space(struct sock *clcsk)
819 {
820 	struct smc_sock *smc;
821 
822 	read_lock_bh(&clcsk->sk_callback_lock);
823 	smc = smc_clcsock_user_data(clcsk);
824 	if (smc)
825 		smc_fback_forward_wakeup(smc, clcsk,
826 					 smc->clcsk_write_space);
827 	read_unlock_bh(&clcsk->sk_callback_lock);
828 }
829 
830 static void smc_fback_error_report(struct sock *clcsk)
831 {
832 	struct smc_sock *smc;
833 
834 	read_lock_bh(&clcsk->sk_callback_lock);
835 	smc = smc_clcsock_user_data(clcsk);
836 	if (smc)
837 		smc_fback_forward_wakeup(smc, clcsk,
838 					 smc->clcsk_error_report);
839 	read_unlock_bh(&clcsk->sk_callback_lock);
840 }
841 
842 static void smc_fback_replace_callbacks(struct smc_sock *smc)
843 {
844 	struct sock *clcsk = smc->clcsock->sk;
845 
846 	write_lock_bh(&clcsk->sk_callback_lock);
847 	clcsk->sk_user_data = (void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
848 
849 	smc_clcsock_replace_cb(&clcsk->sk_state_change, smc_fback_state_change,
850 			       &smc->clcsk_state_change);
851 	smc_clcsock_replace_cb(&clcsk->sk_data_ready, smc_fback_data_ready,
852 			       &smc->clcsk_data_ready);
853 	smc_clcsock_replace_cb(&clcsk->sk_write_space, smc_fback_write_space,
854 			       &smc->clcsk_write_space);
855 	smc_clcsock_replace_cb(&clcsk->sk_error_report, smc_fback_error_report,
856 			       &smc->clcsk_error_report);
857 
858 	write_unlock_bh(&clcsk->sk_callback_lock);
859 }
860 
861 static int smc_switch_to_fallback(struct smc_sock *smc, int reason_code)
862 {
863 	int rc = 0;
864 
865 	mutex_lock(&smc->clcsock_release_lock);
866 	if (!smc->clcsock) {
867 		rc = -EBADF;
868 		goto out;
869 	}
870 
871 	smc->use_fallback = true;
872 	smc->fallback_rsn = reason_code;
873 	smc_stat_fallback(smc);
874 	trace_smc_switch_to_fallback(smc, reason_code);
875 	if (smc->sk.sk_socket && smc->sk.sk_socket->file) {
876 		smc->clcsock->file = smc->sk.sk_socket->file;
877 		smc->clcsock->file->private_data = smc->clcsock;
878 		smc->clcsock->wq.fasync_list =
879 			smc->sk.sk_socket->wq.fasync_list;
880 
881 		/* There might be some wait entries remaining
882 		 * in smc sk->sk_wq and they should be woken up
883 		 * as clcsock's wait queue is woken up.
884 		 */
885 		smc_fback_replace_callbacks(smc);
886 	}
887 out:
888 	mutex_unlock(&smc->clcsock_release_lock);
889 	return rc;
890 }
891 
892 /* fall back during connect */
893 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
894 {
895 	struct net *net = sock_net(&smc->sk);
896 	int rc = 0;
897 
898 	rc = smc_switch_to_fallback(smc, reason_code);
899 	if (rc) { /* fallback fails */
900 		this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
901 		if (smc->sk.sk_state == SMC_INIT)
902 			sock_put(&smc->sk); /* passive closing */
903 		return rc;
904 	}
905 	smc_copy_sock_settings_to_clc(smc);
906 	smc->connect_nonblock = 0;
907 	if (smc->sk.sk_state == SMC_INIT)
908 		smc->sk.sk_state = SMC_ACTIVE;
909 	return 0;
910 }
911 
912 /* decline and fall back during connect */
913 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code,
914 					u8 version)
915 {
916 	struct net *net = sock_net(&smc->sk);
917 	int rc;
918 
919 	if (reason_code < 0) { /* error, fallback is not possible */
920 		this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
921 		if (smc->sk.sk_state == SMC_INIT)
922 			sock_put(&smc->sk); /* passive closing */
923 		return reason_code;
924 	}
925 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
926 		rc = smc_clc_send_decline(smc, reason_code, version);
927 		if (rc < 0) {
928 			this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
929 			if (smc->sk.sk_state == SMC_INIT)
930 				sock_put(&smc->sk); /* passive closing */
931 			return rc;
932 		}
933 	}
934 	return smc_connect_fallback(smc, reason_code);
935 }
936 
937 static void smc_conn_abort(struct smc_sock *smc, int local_first)
938 {
939 	struct smc_connection *conn = &smc->conn;
940 	struct smc_link_group *lgr = conn->lgr;
941 	bool lgr_valid = false;
942 
943 	if (smc_conn_lgr_valid(conn))
944 		lgr_valid = true;
945 
946 	smc_conn_free(conn);
947 	if (local_first && lgr_valid)
948 		smc_lgr_cleanup_early(lgr);
949 }
950 
951 /* check if there is a rdma device available for this connection. */
952 /* called for connect and listen */
953 static int smc_find_rdma_device(struct smc_sock *smc, struct smc_init_info *ini)
954 {
955 	/* PNET table look up: search active ib_device and port
956 	 * within same PNETID that also contains the ethernet device
957 	 * used for the internal TCP socket
958 	 */
959 	smc_pnet_find_roce_resource(smc->clcsock->sk, ini);
960 	if (!ini->check_smcrv2 && !ini->ib_dev)
961 		return SMC_CLC_DECL_NOSMCRDEV;
962 	if (ini->check_smcrv2 && !ini->smcrv2.ib_dev_v2)
963 		return SMC_CLC_DECL_NOSMCRDEV;
964 	return 0;
965 }
966 
967 /* check if there is an ISM device available for this connection. */
968 /* called for connect and listen */
969 static int smc_find_ism_device(struct smc_sock *smc, struct smc_init_info *ini)
970 {
971 	/* Find ISM device with same PNETID as connecting interface  */
972 	smc_pnet_find_ism_resource(smc->clcsock->sk, ini);
973 	if (!ini->ism_dev[0])
974 		return SMC_CLC_DECL_NOSMCDDEV;
975 	else
976 		ini->ism_chid[0] = smc_ism_get_chid(ini->ism_dev[0]);
977 	return 0;
978 }
979 
980 /* is chid unique for the ism devices that are already determined? */
981 static bool smc_find_ism_v2_is_unique_chid(u16 chid, struct smc_init_info *ini,
982 					   int cnt)
983 {
984 	int i = (!ini->ism_dev[0]) ? 1 : 0;
985 
986 	for (; i < cnt; i++)
987 		if (ini->ism_chid[i] == chid)
988 			return false;
989 	return true;
990 }
991 
992 /* determine possible V2 ISM devices (either without PNETID or with PNETID plus
993  * PNETID matching net_device)
994  */
995 static int smc_find_ism_v2_device_clnt(struct smc_sock *smc,
996 				       struct smc_init_info *ini)
997 {
998 	int rc = SMC_CLC_DECL_NOSMCDDEV;
999 	struct smcd_dev *smcd;
1000 	int i = 1;
1001 	u16 chid;
1002 
1003 	if (smcd_indicated(ini->smc_type_v1))
1004 		rc = 0;		/* already initialized for V1 */
1005 	mutex_lock(&smcd_dev_list.mutex);
1006 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
1007 		if (smcd->going_away || smcd == ini->ism_dev[0])
1008 			continue;
1009 		chid = smc_ism_get_chid(smcd);
1010 		if (!smc_find_ism_v2_is_unique_chid(chid, ini, i))
1011 			continue;
1012 		if (!smc_pnet_is_pnetid_set(smcd->pnetid) ||
1013 		    smc_pnet_is_ndev_pnetid(sock_net(&smc->sk), smcd->pnetid)) {
1014 			ini->ism_dev[i] = smcd;
1015 			ini->ism_chid[i] = chid;
1016 			ini->is_smcd = true;
1017 			rc = 0;
1018 			i++;
1019 			if (i > SMC_MAX_ISM_DEVS)
1020 				break;
1021 		}
1022 	}
1023 	mutex_unlock(&smcd_dev_list.mutex);
1024 	ini->ism_offered_cnt = i - 1;
1025 	if (!ini->ism_dev[0] && !ini->ism_dev[1])
1026 		ini->smcd_version = 0;
1027 
1028 	return rc;
1029 }
1030 
1031 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
1032 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
1033 				      struct smc_init_info *ini)
1034 {
1035 	if (ini->vlan_id && smc_ism_get_vlan(ini->ism_dev[0], ini->vlan_id))
1036 		return SMC_CLC_DECL_ISMVLANERR;
1037 	return 0;
1038 }
1039 
1040 static int smc_find_proposal_devices(struct smc_sock *smc,
1041 				     struct smc_init_info *ini)
1042 {
1043 	int rc = 0;
1044 
1045 	/* check if there is an ism device available */
1046 	if (!(ini->smcd_version & SMC_V1) ||
1047 	    smc_find_ism_device(smc, ini) ||
1048 	    smc_connect_ism_vlan_setup(smc, ini))
1049 		ini->smcd_version &= ~SMC_V1;
1050 	/* else ISM V1 is supported for this connection */
1051 
1052 	/* check if there is an rdma device available */
1053 	if (!(ini->smcr_version & SMC_V1) ||
1054 	    smc_find_rdma_device(smc, ini))
1055 		ini->smcr_version &= ~SMC_V1;
1056 	/* else RDMA is supported for this connection */
1057 
1058 	ini->smc_type_v1 = smc_indicated_type(ini->smcd_version & SMC_V1,
1059 					      ini->smcr_version & SMC_V1);
1060 
1061 	/* check if there is an ism v2 device available */
1062 	if (!(ini->smcd_version & SMC_V2) ||
1063 	    !smc_ism_is_v2_capable() ||
1064 	    smc_find_ism_v2_device_clnt(smc, ini))
1065 		ini->smcd_version &= ~SMC_V2;
1066 
1067 	/* check if there is an rdma v2 device available */
1068 	ini->check_smcrv2 = true;
1069 	ini->smcrv2.saddr = smc->clcsock->sk->sk_rcv_saddr;
1070 	if (!(ini->smcr_version & SMC_V2) ||
1071 	    smc->clcsock->sk->sk_family != AF_INET ||
1072 	    !smc_clc_ueid_count() ||
1073 	    smc_find_rdma_device(smc, ini))
1074 		ini->smcr_version &= ~SMC_V2;
1075 	ini->check_smcrv2 = false;
1076 
1077 	ini->smc_type_v2 = smc_indicated_type(ini->smcd_version & SMC_V2,
1078 					      ini->smcr_version & SMC_V2);
1079 
1080 	/* if neither ISM nor RDMA are supported, fallback */
1081 	if (ini->smc_type_v1 == SMC_TYPE_N && ini->smc_type_v2 == SMC_TYPE_N)
1082 		rc = SMC_CLC_DECL_NOSMCDEV;
1083 
1084 	return rc;
1085 }
1086 
1087 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
1088  * used, the VLAN ID will be registered again during the connection setup.
1089  */
1090 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc,
1091 					struct smc_init_info *ini)
1092 {
1093 	if (!smcd_indicated(ini->smc_type_v1))
1094 		return 0;
1095 	if (ini->vlan_id && smc_ism_put_vlan(ini->ism_dev[0], ini->vlan_id))
1096 		return SMC_CLC_DECL_CNFERR;
1097 	return 0;
1098 }
1099 
1100 #define SMC_CLC_MAX_ACCEPT_LEN \
1101 	(sizeof(struct smc_clc_msg_accept_confirm_v2) + \
1102 	 sizeof(struct smc_clc_first_contact_ext) + \
1103 	 sizeof(struct smc_clc_msg_trail))
1104 
1105 /* CLC handshake during connect */
1106 static int smc_connect_clc(struct smc_sock *smc,
1107 			   struct smc_clc_msg_accept_confirm_v2 *aclc2,
1108 			   struct smc_init_info *ini)
1109 {
1110 	int rc = 0;
1111 
1112 	/* do inband token exchange */
1113 	rc = smc_clc_send_proposal(smc, ini);
1114 	if (rc)
1115 		return rc;
1116 	/* receive SMC Accept CLC message */
1117 	return smc_clc_wait_msg(smc, aclc2, SMC_CLC_MAX_ACCEPT_LEN,
1118 				SMC_CLC_ACCEPT, CLC_WAIT_TIME);
1119 }
1120 
1121 void smc_fill_gid_list(struct smc_link_group *lgr,
1122 		       struct smc_gidlist *gidlist,
1123 		       struct smc_ib_device *known_dev, u8 *known_gid)
1124 {
1125 	struct smc_init_info *alt_ini = NULL;
1126 
1127 	memset(gidlist, 0, sizeof(*gidlist));
1128 	memcpy(gidlist->list[gidlist->len++], known_gid, SMC_GID_SIZE);
1129 
1130 	alt_ini = kzalloc(sizeof(*alt_ini), GFP_KERNEL);
1131 	if (!alt_ini)
1132 		goto out;
1133 
1134 	alt_ini->vlan_id = lgr->vlan_id;
1135 	alt_ini->check_smcrv2 = true;
1136 	alt_ini->smcrv2.saddr = lgr->saddr;
1137 	smc_pnet_find_alt_roce(lgr, alt_ini, known_dev);
1138 
1139 	if (!alt_ini->smcrv2.ib_dev_v2)
1140 		goto out;
1141 
1142 	memcpy(gidlist->list[gidlist->len++], alt_ini->smcrv2.ib_gid_v2,
1143 	       SMC_GID_SIZE);
1144 
1145 out:
1146 	kfree(alt_ini);
1147 }
1148 
1149 static int smc_connect_rdma_v2_prepare(struct smc_sock *smc,
1150 				       struct smc_clc_msg_accept_confirm *aclc,
1151 				       struct smc_init_info *ini)
1152 {
1153 	struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
1154 		(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1155 	struct smc_clc_first_contact_ext *fce =
1156 		(struct smc_clc_first_contact_ext *)
1157 			(((u8 *)clc_v2) + sizeof(*clc_v2));
1158 
1159 	if (!ini->first_contact_peer || aclc->hdr.version == SMC_V1)
1160 		return 0;
1161 
1162 	if (fce->v2_direct) {
1163 		memcpy(ini->smcrv2.nexthop_mac, &aclc->r0.lcl.mac, ETH_ALEN);
1164 		ini->smcrv2.uses_gateway = false;
1165 	} else {
1166 		if (smc_ib_find_route(smc->clcsock->sk->sk_rcv_saddr,
1167 				      smc_ib_gid_to_ipv4(aclc->r0.lcl.gid),
1168 				      ini->smcrv2.nexthop_mac,
1169 				      &ini->smcrv2.uses_gateway))
1170 			return SMC_CLC_DECL_NOROUTE;
1171 		if (!ini->smcrv2.uses_gateway) {
1172 			/* mismatch: peer claims indirect, but its direct */
1173 			return SMC_CLC_DECL_NOINDIRECT;
1174 		}
1175 	}
1176 	return 0;
1177 }
1178 
1179 /* setup for RDMA connection of client */
1180 static int smc_connect_rdma(struct smc_sock *smc,
1181 			    struct smc_clc_msg_accept_confirm *aclc,
1182 			    struct smc_init_info *ini)
1183 {
1184 	int i, reason_code = 0;
1185 	struct smc_link *link;
1186 	u8 *eid = NULL;
1187 
1188 	ini->is_smcd = false;
1189 	ini->ib_clcqpn = ntoh24(aclc->r0.qpn);
1190 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
1191 	memcpy(ini->peer_systemid, aclc->r0.lcl.id_for_peer, SMC_SYSTEMID_LEN);
1192 	memcpy(ini->peer_gid, aclc->r0.lcl.gid, SMC_GID_SIZE);
1193 	memcpy(ini->peer_mac, aclc->r0.lcl.mac, ETH_ALEN);
1194 
1195 	reason_code = smc_connect_rdma_v2_prepare(smc, aclc, ini);
1196 	if (reason_code)
1197 		return reason_code;
1198 
1199 	mutex_lock(&smc_client_lgr_pending);
1200 	reason_code = smc_conn_create(smc, ini);
1201 	if (reason_code) {
1202 		mutex_unlock(&smc_client_lgr_pending);
1203 		return reason_code;
1204 	}
1205 
1206 	smc_conn_save_peer_info(smc, aclc);
1207 
1208 	if (ini->first_contact_local) {
1209 		link = smc->conn.lnk;
1210 	} else {
1211 		/* set link that was assigned by server */
1212 		link = NULL;
1213 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1214 			struct smc_link *l = &smc->conn.lgr->lnk[i];
1215 
1216 			if (l->peer_qpn == ntoh24(aclc->r0.qpn) &&
1217 			    !memcmp(l->peer_gid, &aclc->r0.lcl.gid,
1218 				    SMC_GID_SIZE) &&
1219 			    (aclc->hdr.version > SMC_V1 ||
1220 			     !memcmp(l->peer_mac, &aclc->r0.lcl.mac,
1221 				     sizeof(l->peer_mac)))) {
1222 				link = l;
1223 				break;
1224 			}
1225 		}
1226 		if (!link) {
1227 			reason_code = SMC_CLC_DECL_NOSRVLINK;
1228 			goto connect_abort;
1229 		}
1230 		smc_switch_link_and_count(&smc->conn, link);
1231 	}
1232 
1233 	/* create send buffer and rmb */
1234 	if (smc_buf_create(smc, false)) {
1235 		reason_code = SMC_CLC_DECL_MEM;
1236 		goto connect_abort;
1237 	}
1238 
1239 	if (ini->first_contact_local)
1240 		smc_link_save_peer_info(link, aclc, ini);
1241 
1242 	if (smc_rmb_rtoken_handling(&smc->conn, link, aclc)) {
1243 		reason_code = SMC_CLC_DECL_ERR_RTOK;
1244 		goto connect_abort;
1245 	}
1246 
1247 	smc_close_init(smc);
1248 	smc_rx_init(smc);
1249 
1250 	if (ini->first_contact_local) {
1251 		if (smc_ib_ready_link(link)) {
1252 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
1253 			goto connect_abort;
1254 		}
1255 	} else {
1256 		/* reg sendbufs if they were vzalloced */
1257 		if (smc->conn.sndbuf_desc->is_vm) {
1258 			if (smcr_lgr_reg_sndbufs(link, smc->conn.sndbuf_desc)) {
1259 				reason_code = SMC_CLC_DECL_ERR_REGBUF;
1260 				goto connect_abort;
1261 			}
1262 		}
1263 		if (smcr_lgr_reg_rmbs(link, smc->conn.rmb_desc)) {
1264 			reason_code = SMC_CLC_DECL_ERR_REGBUF;
1265 			goto connect_abort;
1266 		}
1267 	}
1268 
1269 	if (aclc->hdr.version > SMC_V1) {
1270 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
1271 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1272 
1273 		eid = clc_v2->r1.eid;
1274 		if (ini->first_contact_local)
1275 			smc_fill_gid_list(link->lgr, &ini->smcrv2.gidlist,
1276 					  link->smcibdev, link->gid);
1277 	}
1278 
1279 	reason_code = smc_clc_send_confirm(smc, ini->first_contact_local,
1280 					   aclc->hdr.version, eid, ini);
1281 	if (reason_code)
1282 		goto connect_abort;
1283 
1284 	smc_tx_init(smc);
1285 
1286 	if (ini->first_contact_local) {
1287 		/* QP confirmation over RoCE fabric */
1288 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
1289 		reason_code = smcr_clnt_conf_first_link(smc);
1290 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
1291 		if (reason_code)
1292 			goto connect_abort;
1293 	}
1294 	mutex_unlock(&smc_client_lgr_pending);
1295 
1296 	smc_copy_sock_settings_to_clc(smc);
1297 	smc->connect_nonblock = 0;
1298 	if (smc->sk.sk_state == SMC_INIT)
1299 		smc->sk.sk_state = SMC_ACTIVE;
1300 
1301 	return 0;
1302 connect_abort:
1303 	smc_conn_abort(smc, ini->first_contact_local);
1304 	mutex_unlock(&smc_client_lgr_pending);
1305 	smc->connect_nonblock = 0;
1306 
1307 	return reason_code;
1308 }
1309 
1310 /* The server has chosen one of the proposed ISM devices for the communication.
1311  * Determine from the CHID of the received CLC ACCEPT the ISM device chosen.
1312  */
1313 static int
1314 smc_v2_determine_accepted_chid(struct smc_clc_msg_accept_confirm_v2 *aclc,
1315 			       struct smc_init_info *ini)
1316 {
1317 	int i;
1318 
1319 	for (i = 0; i < ini->ism_offered_cnt + 1; i++) {
1320 		if (ini->ism_chid[i] == ntohs(aclc->d1.chid)) {
1321 			ini->ism_selected = i;
1322 			return 0;
1323 		}
1324 	}
1325 
1326 	return -EPROTO;
1327 }
1328 
1329 /* setup for ISM connection of client */
1330 static int smc_connect_ism(struct smc_sock *smc,
1331 			   struct smc_clc_msg_accept_confirm *aclc,
1332 			   struct smc_init_info *ini)
1333 {
1334 	u8 *eid = NULL;
1335 	int rc = 0;
1336 
1337 	ini->is_smcd = true;
1338 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
1339 
1340 	if (aclc->hdr.version == SMC_V2) {
1341 		struct smc_clc_msg_accept_confirm_v2 *aclc_v2 =
1342 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1343 
1344 		rc = smc_v2_determine_accepted_chid(aclc_v2, ini);
1345 		if (rc)
1346 			return rc;
1347 	}
1348 	ini->ism_peer_gid[ini->ism_selected] = aclc->d0.gid;
1349 
1350 	/* there is only one lgr role for SMC-D; use server lock */
1351 	mutex_lock(&smc_server_lgr_pending);
1352 	rc = smc_conn_create(smc, ini);
1353 	if (rc) {
1354 		mutex_unlock(&smc_server_lgr_pending);
1355 		return rc;
1356 	}
1357 
1358 	/* Create send and receive buffers */
1359 	rc = smc_buf_create(smc, true);
1360 	if (rc) {
1361 		rc = (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB : SMC_CLC_DECL_MEM;
1362 		goto connect_abort;
1363 	}
1364 
1365 	smc_conn_save_peer_info(smc, aclc);
1366 	smc_close_init(smc);
1367 	smc_rx_init(smc);
1368 	smc_tx_init(smc);
1369 
1370 	if (aclc->hdr.version > SMC_V1) {
1371 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
1372 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1373 
1374 		eid = clc_v2->d1.eid;
1375 	}
1376 
1377 	rc = smc_clc_send_confirm(smc, ini->first_contact_local,
1378 				  aclc->hdr.version, eid, NULL);
1379 	if (rc)
1380 		goto connect_abort;
1381 	mutex_unlock(&smc_server_lgr_pending);
1382 
1383 	smc_copy_sock_settings_to_clc(smc);
1384 	smc->connect_nonblock = 0;
1385 	if (smc->sk.sk_state == SMC_INIT)
1386 		smc->sk.sk_state = SMC_ACTIVE;
1387 
1388 	return 0;
1389 connect_abort:
1390 	smc_conn_abort(smc, ini->first_contact_local);
1391 	mutex_unlock(&smc_server_lgr_pending);
1392 	smc->connect_nonblock = 0;
1393 
1394 	return rc;
1395 }
1396 
1397 /* check if received accept type and version matches a proposed one */
1398 static int smc_connect_check_aclc(struct smc_init_info *ini,
1399 				  struct smc_clc_msg_accept_confirm *aclc)
1400 {
1401 	if (aclc->hdr.typev1 != SMC_TYPE_R &&
1402 	    aclc->hdr.typev1 != SMC_TYPE_D)
1403 		return SMC_CLC_DECL_MODEUNSUPP;
1404 
1405 	if (aclc->hdr.version >= SMC_V2) {
1406 		if ((aclc->hdr.typev1 == SMC_TYPE_R &&
1407 		     !smcr_indicated(ini->smc_type_v2)) ||
1408 		    (aclc->hdr.typev1 == SMC_TYPE_D &&
1409 		     !smcd_indicated(ini->smc_type_v2)))
1410 			return SMC_CLC_DECL_MODEUNSUPP;
1411 	} else {
1412 		if ((aclc->hdr.typev1 == SMC_TYPE_R &&
1413 		     !smcr_indicated(ini->smc_type_v1)) ||
1414 		    (aclc->hdr.typev1 == SMC_TYPE_D &&
1415 		     !smcd_indicated(ini->smc_type_v1)))
1416 			return SMC_CLC_DECL_MODEUNSUPP;
1417 	}
1418 
1419 	return 0;
1420 }
1421 
1422 /* perform steps before actually connecting */
1423 static int __smc_connect(struct smc_sock *smc)
1424 {
1425 	u8 version = smc_ism_is_v2_capable() ? SMC_V2 : SMC_V1;
1426 	struct smc_clc_msg_accept_confirm_v2 *aclc2;
1427 	struct smc_clc_msg_accept_confirm *aclc;
1428 	struct smc_init_info *ini = NULL;
1429 	u8 *buf = NULL;
1430 	int rc = 0;
1431 
1432 	if (smc->use_fallback)
1433 		return smc_connect_fallback(smc, smc->fallback_rsn);
1434 
1435 	/* if peer has not signalled SMC-capability, fall back */
1436 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
1437 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
1438 
1439 	/* IPSec connections opt out of SMC optimizations */
1440 	if (using_ipsec(smc))
1441 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC,
1442 						    version);
1443 
1444 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1445 	if (!ini)
1446 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_MEM,
1447 						    version);
1448 
1449 	ini->smcd_version = SMC_V1 | SMC_V2;
1450 	ini->smcr_version = SMC_V1 | SMC_V2;
1451 	ini->smc_type_v1 = SMC_TYPE_B;
1452 	ini->smc_type_v2 = SMC_TYPE_B;
1453 
1454 	/* get vlan id from IP device */
1455 	if (smc_vlan_by_tcpsk(smc->clcsock, ini)) {
1456 		ini->smcd_version &= ~SMC_V1;
1457 		ini->smcr_version = 0;
1458 		ini->smc_type_v1 = SMC_TYPE_N;
1459 		if (!ini->smcd_version) {
1460 			rc = SMC_CLC_DECL_GETVLANERR;
1461 			goto fallback;
1462 		}
1463 	}
1464 
1465 	rc = smc_find_proposal_devices(smc, ini);
1466 	if (rc)
1467 		goto fallback;
1468 
1469 	buf = kzalloc(SMC_CLC_MAX_ACCEPT_LEN, GFP_KERNEL);
1470 	if (!buf) {
1471 		rc = SMC_CLC_DECL_MEM;
1472 		goto fallback;
1473 	}
1474 	aclc2 = (struct smc_clc_msg_accept_confirm_v2 *)buf;
1475 	aclc = (struct smc_clc_msg_accept_confirm *)aclc2;
1476 
1477 	/* perform CLC handshake */
1478 	rc = smc_connect_clc(smc, aclc2, ini);
1479 	if (rc) {
1480 		/* -EAGAIN on timeout, see tcp_recvmsg() */
1481 		if (rc == -EAGAIN) {
1482 			rc = -ETIMEDOUT;
1483 			smc->sk.sk_err = ETIMEDOUT;
1484 		}
1485 		goto vlan_cleanup;
1486 	}
1487 
1488 	/* check if smc modes and versions of CLC proposal and accept match */
1489 	rc = smc_connect_check_aclc(ini, aclc);
1490 	version = aclc->hdr.version == SMC_V1 ? SMC_V1 : SMC_V2;
1491 	if (rc)
1492 		goto vlan_cleanup;
1493 
1494 	/* depending on previous steps, connect using rdma or ism */
1495 	if (aclc->hdr.typev1 == SMC_TYPE_R) {
1496 		ini->smcr_version = version;
1497 		rc = smc_connect_rdma(smc, aclc, ini);
1498 	} else if (aclc->hdr.typev1 == SMC_TYPE_D) {
1499 		ini->smcd_version = version;
1500 		rc = smc_connect_ism(smc, aclc, ini);
1501 	}
1502 	if (rc)
1503 		goto vlan_cleanup;
1504 
1505 	SMC_STAT_CLNT_SUCC_INC(sock_net(smc->clcsock->sk), aclc);
1506 	smc_connect_ism_vlan_cleanup(smc, ini);
1507 	kfree(buf);
1508 	kfree(ini);
1509 	return 0;
1510 
1511 vlan_cleanup:
1512 	smc_connect_ism_vlan_cleanup(smc, ini);
1513 	kfree(buf);
1514 fallback:
1515 	kfree(ini);
1516 	return smc_connect_decline_fallback(smc, rc, version);
1517 }
1518 
1519 static void smc_connect_work(struct work_struct *work)
1520 {
1521 	struct smc_sock *smc = container_of(work, struct smc_sock,
1522 					    connect_work);
1523 	long timeo = smc->sk.sk_sndtimeo;
1524 	int rc = 0;
1525 
1526 	if (!timeo)
1527 		timeo = MAX_SCHEDULE_TIMEOUT;
1528 	lock_sock(smc->clcsock->sk);
1529 	if (smc->clcsock->sk->sk_err) {
1530 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
1531 	} else if ((1 << smc->clcsock->sk->sk_state) &
1532 					(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
1533 		rc = sk_stream_wait_connect(smc->clcsock->sk, &timeo);
1534 		if ((rc == -EPIPE) &&
1535 		    ((1 << smc->clcsock->sk->sk_state) &
1536 					(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))
1537 			rc = 0;
1538 	}
1539 	release_sock(smc->clcsock->sk);
1540 	lock_sock(&smc->sk);
1541 	if (rc != 0 || smc->sk.sk_err) {
1542 		smc->sk.sk_state = SMC_CLOSED;
1543 		if (rc == -EPIPE || rc == -EAGAIN)
1544 			smc->sk.sk_err = EPIPE;
1545 		else if (rc == -ECONNREFUSED)
1546 			smc->sk.sk_err = ECONNREFUSED;
1547 		else if (signal_pending(current))
1548 			smc->sk.sk_err = -sock_intr_errno(timeo);
1549 		sock_put(&smc->sk); /* passive closing */
1550 		goto out;
1551 	}
1552 
1553 	rc = __smc_connect(smc);
1554 	if (rc < 0)
1555 		smc->sk.sk_err = -rc;
1556 
1557 out:
1558 	if (!sock_flag(&smc->sk, SOCK_DEAD)) {
1559 		if (smc->sk.sk_err) {
1560 			smc->sk.sk_state_change(&smc->sk);
1561 		} else { /* allow polling before and after fallback decision */
1562 			smc->clcsock->sk->sk_write_space(smc->clcsock->sk);
1563 			smc->sk.sk_write_space(&smc->sk);
1564 		}
1565 	}
1566 	release_sock(&smc->sk);
1567 }
1568 
1569 static int smc_connect(struct socket *sock, struct sockaddr *addr,
1570 		       int alen, int flags)
1571 {
1572 	struct sock *sk = sock->sk;
1573 	struct smc_sock *smc;
1574 	int rc = -EINVAL;
1575 
1576 	smc = smc_sk(sk);
1577 
1578 	/* separate smc parameter checking to be safe */
1579 	if (alen < sizeof(addr->sa_family))
1580 		goto out_err;
1581 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
1582 		goto out_err;
1583 
1584 	lock_sock(sk);
1585 	switch (sock->state) {
1586 	default:
1587 		rc = -EINVAL;
1588 		goto out;
1589 	case SS_CONNECTED:
1590 		rc = sk->sk_state == SMC_ACTIVE ? -EISCONN : -EINVAL;
1591 		goto out;
1592 	case SS_CONNECTING:
1593 		if (sk->sk_state == SMC_ACTIVE)
1594 			goto connected;
1595 		break;
1596 	case SS_UNCONNECTED:
1597 		sock->state = SS_CONNECTING;
1598 		break;
1599 	}
1600 
1601 	switch (sk->sk_state) {
1602 	default:
1603 		goto out;
1604 	case SMC_CLOSED:
1605 		rc = sock_error(sk) ? : -ECONNABORTED;
1606 		sock->state = SS_UNCONNECTED;
1607 		goto out;
1608 	case SMC_ACTIVE:
1609 		rc = -EISCONN;
1610 		goto out;
1611 	case SMC_INIT:
1612 		break;
1613 	}
1614 
1615 	smc_copy_sock_settings_to_clc(smc);
1616 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1617 	if (smc->connect_nonblock) {
1618 		rc = -EALREADY;
1619 		goto out;
1620 	}
1621 	rc = kernel_connect(smc->clcsock, addr, alen, flags);
1622 	if (rc && rc != -EINPROGRESS)
1623 		goto out;
1624 
1625 	if (smc->use_fallback) {
1626 		sock->state = rc ? SS_CONNECTING : SS_CONNECTED;
1627 		goto out;
1628 	}
1629 	sock_hold(&smc->sk); /* sock put in passive closing */
1630 	if (flags & O_NONBLOCK) {
1631 		if (queue_work(smc_hs_wq, &smc->connect_work))
1632 			smc->connect_nonblock = 1;
1633 		rc = -EINPROGRESS;
1634 		goto out;
1635 	} else {
1636 		rc = __smc_connect(smc);
1637 		if (rc < 0)
1638 			goto out;
1639 	}
1640 
1641 connected:
1642 	rc = 0;
1643 	sock->state = SS_CONNECTED;
1644 out:
1645 	release_sock(sk);
1646 out_err:
1647 	return rc;
1648 }
1649 
1650 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
1651 {
1652 	struct socket *new_clcsock = NULL;
1653 	struct sock *lsk = &lsmc->sk;
1654 	struct sock *new_sk;
1655 	int rc = -EINVAL;
1656 
1657 	release_sock(lsk);
1658 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
1659 	if (!new_sk) {
1660 		rc = -ENOMEM;
1661 		lsk->sk_err = ENOMEM;
1662 		*new_smc = NULL;
1663 		lock_sock(lsk);
1664 		goto out;
1665 	}
1666 	*new_smc = smc_sk(new_sk);
1667 
1668 	mutex_lock(&lsmc->clcsock_release_lock);
1669 	if (lsmc->clcsock)
1670 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, SOCK_NONBLOCK);
1671 	mutex_unlock(&lsmc->clcsock_release_lock);
1672 	lock_sock(lsk);
1673 	if  (rc < 0 && rc != -EAGAIN)
1674 		lsk->sk_err = -rc;
1675 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
1676 		new_sk->sk_prot->unhash(new_sk);
1677 		if (new_clcsock)
1678 			sock_release(new_clcsock);
1679 		new_sk->sk_state = SMC_CLOSED;
1680 		sock_set_flag(new_sk, SOCK_DEAD);
1681 		sock_put(new_sk); /* final */
1682 		*new_smc = NULL;
1683 		goto out;
1684 	}
1685 
1686 	/* new clcsock has inherited the smc listen-specific sk_data_ready
1687 	 * function; switch it back to the original sk_data_ready function
1688 	 */
1689 	new_clcsock->sk->sk_data_ready = lsmc->clcsk_data_ready;
1690 
1691 	/* if new clcsock has also inherited the fallback-specific callback
1692 	 * functions, switch them back to the original ones.
1693 	 */
1694 	if (lsmc->use_fallback) {
1695 		if (lsmc->clcsk_state_change)
1696 			new_clcsock->sk->sk_state_change = lsmc->clcsk_state_change;
1697 		if (lsmc->clcsk_write_space)
1698 			new_clcsock->sk->sk_write_space = lsmc->clcsk_write_space;
1699 		if (lsmc->clcsk_error_report)
1700 			new_clcsock->sk->sk_error_report = lsmc->clcsk_error_report;
1701 	}
1702 
1703 	(*new_smc)->clcsock = new_clcsock;
1704 out:
1705 	return rc;
1706 }
1707 
1708 /* add a just created sock to the accept queue of the listen sock as
1709  * candidate for a following socket accept call from user space
1710  */
1711 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
1712 {
1713 	struct smc_sock *par = smc_sk(parent);
1714 
1715 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
1716 	spin_lock(&par->accept_q_lock);
1717 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
1718 	spin_unlock(&par->accept_q_lock);
1719 	sk_acceptq_added(parent);
1720 }
1721 
1722 /* remove a socket from the accept queue of its parental listening socket */
1723 static void smc_accept_unlink(struct sock *sk)
1724 {
1725 	struct smc_sock *par = smc_sk(sk)->listen_smc;
1726 
1727 	spin_lock(&par->accept_q_lock);
1728 	list_del_init(&smc_sk(sk)->accept_q);
1729 	spin_unlock(&par->accept_q_lock);
1730 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
1731 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
1732 }
1733 
1734 /* remove a sock from the accept queue to bind it to a new socket created
1735  * for a socket accept call from user space
1736  */
1737 struct sock *smc_accept_dequeue(struct sock *parent,
1738 				struct socket *new_sock)
1739 {
1740 	struct smc_sock *isk, *n;
1741 	struct sock *new_sk;
1742 
1743 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
1744 		new_sk = (struct sock *)isk;
1745 
1746 		smc_accept_unlink(new_sk);
1747 		if (new_sk->sk_state == SMC_CLOSED) {
1748 			new_sk->sk_prot->unhash(new_sk);
1749 			if (isk->clcsock) {
1750 				sock_release(isk->clcsock);
1751 				isk->clcsock = NULL;
1752 			}
1753 			sock_put(new_sk); /* final */
1754 			continue;
1755 		}
1756 		if (new_sock) {
1757 			sock_graft(new_sk, new_sock);
1758 			new_sock->state = SS_CONNECTED;
1759 			if (isk->use_fallback) {
1760 				smc_sk(new_sk)->clcsock->file = new_sock->file;
1761 				isk->clcsock->file->private_data = isk->clcsock;
1762 			}
1763 		}
1764 		return new_sk;
1765 	}
1766 	return NULL;
1767 }
1768 
1769 /* clean up for a created but never accepted sock */
1770 void smc_close_non_accepted(struct sock *sk)
1771 {
1772 	struct smc_sock *smc = smc_sk(sk);
1773 
1774 	sock_hold(sk); /* sock_put below */
1775 	lock_sock(sk);
1776 	if (!sk->sk_lingertime)
1777 		/* wait for peer closing */
1778 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
1779 	__smc_release(smc);
1780 	release_sock(sk);
1781 	sock_put(sk); /* sock_hold above */
1782 	sock_put(sk); /* final sock_put */
1783 }
1784 
1785 static int smcr_serv_conf_first_link(struct smc_sock *smc)
1786 {
1787 	struct smc_link *link = smc->conn.lnk;
1788 	struct smc_llc_qentry *qentry;
1789 	int rc;
1790 
1791 	/* reg the sndbuf if it was vzalloced*/
1792 	if (smc->conn.sndbuf_desc->is_vm) {
1793 		if (smcr_link_reg_buf(link, smc->conn.sndbuf_desc))
1794 			return SMC_CLC_DECL_ERR_REGBUF;
1795 	}
1796 
1797 	/* reg the rmb */
1798 	if (smcr_link_reg_buf(link, smc->conn.rmb_desc))
1799 		return SMC_CLC_DECL_ERR_REGBUF;
1800 
1801 	/* send CONFIRM LINK request to client over the RoCE fabric */
1802 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
1803 	if (rc < 0)
1804 		return SMC_CLC_DECL_TIMEOUT_CL;
1805 
1806 	/* receive CONFIRM LINK response from client over the RoCE fabric */
1807 	qentry = smc_llc_wait(link->lgr, link, SMC_LLC_WAIT_TIME,
1808 			      SMC_LLC_CONFIRM_LINK);
1809 	if (!qentry) {
1810 		struct smc_clc_msg_decline dclc;
1811 
1812 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1813 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1814 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
1815 	}
1816 	smc_llc_save_peer_uid(qentry);
1817 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_RESP);
1818 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
1819 	if (rc)
1820 		return SMC_CLC_DECL_RMBE_EC;
1821 
1822 	/* confirm_rkey is implicit on 1st contact */
1823 	smc->conn.rmb_desc->is_conf_rkey = true;
1824 
1825 	smc_llc_link_active(link);
1826 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
1827 
1828 	/* initial contact - try to establish second link */
1829 	smc_llc_srv_add_link(link, NULL);
1830 	return 0;
1831 }
1832 
1833 /* listen worker: finish */
1834 static void smc_listen_out(struct smc_sock *new_smc)
1835 {
1836 	struct smc_sock *lsmc = new_smc->listen_smc;
1837 	struct sock *newsmcsk = &new_smc->sk;
1838 
1839 	if (tcp_sk(new_smc->clcsock->sk)->syn_smc)
1840 		atomic_dec(&lsmc->queued_smc_hs);
1841 
1842 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1843 		lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1844 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1845 		release_sock(&lsmc->sk);
1846 	} else { /* no longer listening */
1847 		smc_close_non_accepted(newsmcsk);
1848 	}
1849 
1850 	/* Wake up accept */
1851 	lsmc->sk.sk_data_ready(&lsmc->sk);
1852 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1853 }
1854 
1855 /* listen worker: finish in state connected */
1856 static void smc_listen_out_connected(struct smc_sock *new_smc)
1857 {
1858 	struct sock *newsmcsk = &new_smc->sk;
1859 
1860 	if (newsmcsk->sk_state == SMC_INIT)
1861 		newsmcsk->sk_state = SMC_ACTIVE;
1862 
1863 	smc_listen_out(new_smc);
1864 }
1865 
1866 /* listen worker: finish in error state */
1867 static void smc_listen_out_err(struct smc_sock *new_smc)
1868 {
1869 	struct sock *newsmcsk = &new_smc->sk;
1870 	struct net *net = sock_net(newsmcsk);
1871 
1872 	this_cpu_inc(net->smc.smc_stats->srv_hshake_err_cnt);
1873 	if (newsmcsk->sk_state == SMC_INIT)
1874 		sock_put(&new_smc->sk); /* passive closing */
1875 	newsmcsk->sk_state = SMC_CLOSED;
1876 
1877 	smc_listen_out(new_smc);
1878 }
1879 
1880 /* listen worker: decline and fall back if possible */
1881 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1882 			       int local_first, u8 version)
1883 {
1884 	/* RDMA setup failed, switch back to TCP */
1885 	smc_conn_abort(new_smc, local_first);
1886 	if (reason_code < 0 ||
1887 	    smc_switch_to_fallback(new_smc, reason_code)) {
1888 		/* error, no fallback possible */
1889 		smc_listen_out_err(new_smc);
1890 		return;
1891 	}
1892 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1893 		if (smc_clc_send_decline(new_smc, reason_code, version) < 0) {
1894 			smc_listen_out_err(new_smc);
1895 			return;
1896 		}
1897 	}
1898 	smc_listen_out_connected(new_smc);
1899 }
1900 
1901 /* listen worker: version checking */
1902 static int smc_listen_v2_check(struct smc_sock *new_smc,
1903 			       struct smc_clc_msg_proposal *pclc,
1904 			       struct smc_init_info *ini)
1905 {
1906 	struct smc_clc_smcd_v2_extension *pclc_smcd_v2_ext;
1907 	struct smc_clc_v2_extension *pclc_v2_ext;
1908 	int rc = SMC_CLC_DECL_PEERNOSMC;
1909 
1910 	ini->smc_type_v1 = pclc->hdr.typev1;
1911 	ini->smc_type_v2 = pclc->hdr.typev2;
1912 	ini->smcd_version = smcd_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
1913 	ini->smcr_version = smcr_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
1914 	if (pclc->hdr.version > SMC_V1) {
1915 		if (smcd_indicated(ini->smc_type_v2))
1916 			ini->smcd_version |= SMC_V2;
1917 		if (smcr_indicated(ini->smc_type_v2))
1918 			ini->smcr_version |= SMC_V2;
1919 	}
1920 	if (!(ini->smcd_version & SMC_V2) && !(ini->smcr_version & SMC_V2)) {
1921 		rc = SMC_CLC_DECL_PEERNOSMC;
1922 		goto out;
1923 	}
1924 	pclc_v2_ext = smc_get_clc_v2_ext(pclc);
1925 	if (!pclc_v2_ext) {
1926 		ini->smcd_version &= ~SMC_V2;
1927 		ini->smcr_version &= ~SMC_V2;
1928 		rc = SMC_CLC_DECL_NOV2EXT;
1929 		goto out;
1930 	}
1931 	pclc_smcd_v2_ext = smc_get_clc_smcd_v2_ext(pclc_v2_ext);
1932 	if (ini->smcd_version & SMC_V2) {
1933 		if (!smc_ism_is_v2_capable()) {
1934 			ini->smcd_version &= ~SMC_V2;
1935 			rc = SMC_CLC_DECL_NOISM2SUPP;
1936 		} else if (!pclc_smcd_v2_ext) {
1937 			ini->smcd_version &= ~SMC_V2;
1938 			rc = SMC_CLC_DECL_NOV2DEXT;
1939 		} else if (!pclc_v2_ext->hdr.eid_cnt &&
1940 			   !pclc_v2_ext->hdr.flag.seid) {
1941 			ini->smcd_version &= ~SMC_V2;
1942 			rc = SMC_CLC_DECL_NOUEID;
1943 		}
1944 	}
1945 	if (ini->smcr_version & SMC_V2) {
1946 		if (!pclc_v2_ext->hdr.eid_cnt) {
1947 			ini->smcr_version &= ~SMC_V2;
1948 			rc = SMC_CLC_DECL_NOUEID;
1949 		}
1950 	}
1951 
1952 out:
1953 	if (!ini->smcd_version && !ini->smcr_version)
1954 		return rc;
1955 
1956 	return 0;
1957 }
1958 
1959 /* listen worker: check prefixes */
1960 static int smc_listen_prfx_check(struct smc_sock *new_smc,
1961 				 struct smc_clc_msg_proposal *pclc)
1962 {
1963 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1964 	struct socket *newclcsock = new_smc->clcsock;
1965 
1966 	if (pclc->hdr.typev1 == SMC_TYPE_N)
1967 		return 0;
1968 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1969 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1970 		return SMC_CLC_DECL_DIFFPREFIX;
1971 
1972 	return 0;
1973 }
1974 
1975 /* listen worker: initialize connection and buffers */
1976 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1977 				struct smc_init_info *ini)
1978 {
1979 	int rc;
1980 
1981 	/* allocate connection / link group */
1982 	rc = smc_conn_create(new_smc, ini);
1983 	if (rc)
1984 		return rc;
1985 
1986 	/* create send buffer and rmb */
1987 	if (smc_buf_create(new_smc, false))
1988 		return SMC_CLC_DECL_MEM;
1989 
1990 	return 0;
1991 }
1992 
1993 /* listen worker: initialize connection and buffers for SMC-D */
1994 static int smc_listen_ism_init(struct smc_sock *new_smc,
1995 			       struct smc_init_info *ini)
1996 {
1997 	int rc;
1998 
1999 	rc = smc_conn_create(new_smc, ini);
2000 	if (rc)
2001 		return rc;
2002 
2003 	/* Create send and receive buffers */
2004 	rc = smc_buf_create(new_smc, true);
2005 	if (rc) {
2006 		smc_conn_abort(new_smc, ini->first_contact_local);
2007 		return (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB :
2008 					 SMC_CLC_DECL_MEM;
2009 	}
2010 
2011 	return 0;
2012 }
2013 
2014 static bool smc_is_already_selected(struct smcd_dev *smcd,
2015 				    struct smc_init_info *ini,
2016 				    int matches)
2017 {
2018 	int i;
2019 
2020 	for (i = 0; i < matches; i++)
2021 		if (smcd == ini->ism_dev[i])
2022 			return true;
2023 
2024 	return false;
2025 }
2026 
2027 /* check for ISM devices matching proposed ISM devices */
2028 static void smc_check_ism_v2_match(struct smc_init_info *ini,
2029 				   u16 proposed_chid, u64 proposed_gid,
2030 				   unsigned int *matches)
2031 {
2032 	struct smcd_dev *smcd;
2033 
2034 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
2035 		if (smcd->going_away)
2036 			continue;
2037 		if (smc_is_already_selected(smcd, ini, *matches))
2038 			continue;
2039 		if (smc_ism_get_chid(smcd) == proposed_chid &&
2040 		    !smc_ism_cantalk(proposed_gid, ISM_RESERVED_VLANID, smcd)) {
2041 			ini->ism_peer_gid[*matches] = proposed_gid;
2042 			ini->ism_dev[*matches] = smcd;
2043 			(*matches)++;
2044 			break;
2045 		}
2046 	}
2047 }
2048 
2049 static void smc_find_ism_store_rc(u32 rc, struct smc_init_info *ini)
2050 {
2051 	if (!ini->rc)
2052 		ini->rc = rc;
2053 }
2054 
2055 static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
2056 					struct smc_clc_msg_proposal *pclc,
2057 					struct smc_init_info *ini)
2058 {
2059 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
2060 	struct smc_clc_v2_extension *smc_v2_ext;
2061 	struct smc_clc_msg_smcd *pclc_smcd;
2062 	unsigned int matches = 0;
2063 	u8 smcd_version;
2064 	u8 *eid = NULL;
2065 	int i, rc;
2066 
2067 	if (!(ini->smcd_version & SMC_V2) || !smcd_indicated(ini->smc_type_v2))
2068 		goto not_found;
2069 
2070 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
2071 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
2072 	smcd_v2_ext = smc_get_clc_smcd_v2_ext(smc_v2_ext);
2073 
2074 	mutex_lock(&smcd_dev_list.mutex);
2075 	if (pclc_smcd->ism.chid)
2076 		/* check for ISM device matching proposed native ISM device */
2077 		smc_check_ism_v2_match(ini, ntohs(pclc_smcd->ism.chid),
2078 				       ntohll(pclc_smcd->ism.gid), &matches);
2079 	for (i = 1; i <= smc_v2_ext->hdr.ism_gid_cnt; i++) {
2080 		/* check for ISM devices matching proposed non-native ISM
2081 		 * devices
2082 		 */
2083 		smc_check_ism_v2_match(ini,
2084 				       ntohs(smcd_v2_ext->gidchid[i - 1].chid),
2085 				       ntohll(smcd_v2_ext->gidchid[i - 1].gid),
2086 				       &matches);
2087 	}
2088 	mutex_unlock(&smcd_dev_list.mutex);
2089 
2090 	if (!ini->ism_dev[0]) {
2091 		smc_find_ism_store_rc(SMC_CLC_DECL_NOSMCD2DEV, ini);
2092 		goto not_found;
2093 	}
2094 
2095 	smc_ism_get_system_eid(&eid);
2096 	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext,
2097 			       smcd_v2_ext->system_eid, eid))
2098 		goto not_found;
2099 
2100 	/* separate - outside the smcd_dev_list.lock */
2101 	smcd_version = ini->smcd_version;
2102 	for (i = 0; i < matches; i++) {
2103 		ini->smcd_version = SMC_V2;
2104 		ini->is_smcd = true;
2105 		ini->ism_selected = i;
2106 		rc = smc_listen_ism_init(new_smc, ini);
2107 		if (rc) {
2108 			smc_find_ism_store_rc(rc, ini);
2109 			/* try next active ISM device */
2110 			continue;
2111 		}
2112 		return; /* matching and usable V2 ISM device found */
2113 	}
2114 	/* no V2 ISM device could be initialized */
2115 	ini->smcd_version = smcd_version;	/* restore original value */
2116 	ini->negotiated_eid[0] = 0;
2117 
2118 not_found:
2119 	ini->smcd_version &= ~SMC_V2;
2120 	ini->ism_dev[0] = NULL;
2121 	ini->is_smcd = false;
2122 }
2123 
2124 static void smc_find_ism_v1_device_serv(struct smc_sock *new_smc,
2125 					struct smc_clc_msg_proposal *pclc,
2126 					struct smc_init_info *ini)
2127 {
2128 	struct smc_clc_msg_smcd *pclc_smcd = smc_get_clc_msg_smcd(pclc);
2129 	int rc = 0;
2130 
2131 	/* check if ISM V1 is available */
2132 	if (!(ini->smcd_version & SMC_V1) || !smcd_indicated(ini->smc_type_v1))
2133 		goto not_found;
2134 	ini->is_smcd = true; /* prepare ISM check */
2135 	ini->ism_peer_gid[0] = ntohll(pclc_smcd->ism.gid);
2136 	rc = smc_find_ism_device(new_smc, ini);
2137 	if (rc)
2138 		goto not_found;
2139 	ini->ism_selected = 0;
2140 	rc = smc_listen_ism_init(new_smc, ini);
2141 	if (!rc)
2142 		return;		/* V1 ISM device found */
2143 
2144 not_found:
2145 	smc_find_ism_store_rc(rc, ini);
2146 	ini->smcd_version &= ~SMC_V1;
2147 	ini->ism_dev[0] = NULL;
2148 	ini->is_smcd = false;
2149 }
2150 
2151 /* listen worker: register buffers */
2152 static int smc_listen_rdma_reg(struct smc_sock *new_smc, bool local_first)
2153 {
2154 	struct smc_connection *conn = &new_smc->conn;
2155 
2156 	if (!local_first) {
2157 		/* reg sendbufs if they were vzalloced */
2158 		if (conn->sndbuf_desc->is_vm) {
2159 			if (smcr_lgr_reg_sndbufs(conn->lnk,
2160 						 conn->sndbuf_desc))
2161 				return SMC_CLC_DECL_ERR_REGBUF;
2162 		}
2163 		if (smcr_lgr_reg_rmbs(conn->lnk, conn->rmb_desc))
2164 			return SMC_CLC_DECL_ERR_REGBUF;
2165 	}
2166 
2167 	return 0;
2168 }
2169 
2170 static void smc_find_rdma_v2_device_serv(struct smc_sock *new_smc,
2171 					 struct smc_clc_msg_proposal *pclc,
2172 					 struct smc_init_info *ini)
2173 {
2174 	struct smc_clc_v2_extension *smc_v2_ext;
2175 	u8 smcr_version;
2176 	int rc;
2177 
2178 	if (!(ini->smcr_version & SMC_V2) || !smcr_indicated(ini->smc_type_v2))
2179 		goto not_found;
2180 
2181 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
2182 	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext, NULL, NULL))
2183 		goto not_found;
2184 
2185 	/* prepare RDMA check */
2186 	memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
2187 	memcpy(ini->peer_gid, smc_v2_ext->roce, SMC_GID_SIZE);
2188 	memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
2189 	ini->check_smcrv2 = true;
2190 	ini->smcrv2.clc_sk = new_smc->clcsock->sk;
2191 	ini->smcrv2.saddr = new_smc->clcsock->sk->sk_rcv_saddr;
2192 	ini->smcrv2.daddr = smc_ib_gid_to_ipv4(smc_v2_ext->roce);
2193 	rc = smc_find_rdma_device(new_smc, ini);
2194 	if (rc) {
2195 		smc_find_ism_store_rc(rc, ini);
2196 		goto not_found;
2197 	}
2198 	if (!ini->smcrv2.uses_gateway)
2199 		memcpy(ini->smcrv2.nexthop_mac, pclc->lcl.mac, ETH_ALEN);
2200 
2201 	smcr_version = ini->smcr_version;
2202 	ini->smcr_version = SMC_V2;
2203 	rc = smc_listen_rdma_init(new_smc, ini);
2204 	if (!rc)
2205 		rc = smc_listen_rdma_reg(new_smc, ini->first_contact_local);
2206 	if (!rc)
2207 		return;
2208 	ini->smcr_version = smcr_version;
2209 	smc_find_ism_store_rc(rc, ini);
2210 
2211 not_found:
2212 	ini->smcr_version &= ~SMC_V2;
2213 	ini->smcrv2.ib_dev_v2 = NULL;
2214 	ini->check_smcrv2 = false;
2215 }
2216 
2217 static int smc_find_rdma_v1_device_serv(struct smc_sock *new_smc,
2218 					struct smc_clc_msg_proposal *pclc,
2219 					struct smc_init_info *ini)
2220 {
2221 	int rc;
2222 
2223 	if (!(ini->smcr_version & SMC_V1) || !smcr_indicated(ini->smc_type_v1))
2224 		return SMC_CLC_DECL_NOSMCDEV;
2225 
2226 	/* prepare RDMA check */
2227 	memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
2228 	memcpy(ini->peer_gid, pclc->lcl.gid, SMC_GID_SIZE);
2229 	memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
2230 	rc = smc_find_rdma_device(new_smc, ini);
2231 	if (rc) {
2232 		/* no RDMA device found */
2233 		return SMC_CLC_DECL_NOSMCDEV;
2234 	}
2235 	rc = smc_listen_rdma_init(new_smc, ini);
2236 	if (rc)
2237 		return rc;
2238 	return smc_listen_rdma_reg(new_smc, ini->first_contact_local);
2239 }
2240 
2241 /* determine the local device matching to proposal */
2242 static int smc_listen_find_device(struct smc_sock *new_smc,
2243 				  struct smc_clc_msg_proposal *pclc,
2244 				  struct smc_init_info *ini)
2245 {
2246 	int prfx_rc;
2247 
2248 	/* check for ISM device matching V2 proposed device */
2249 	smc_find_ism_v2_device_serv(new_smc, pclc, ini);
2250 	if (ini->ism_dev[0])
2251 		return 0;
2252 
2253 	/* check for matching IP prefix and subnet length (V1) */
2254 	prfx_rc = smc_listen_prfx_check(new_smc, pclc);
2255 	if (prfx_rc)
2256 		smc_find_ism_store_rc(prfx_rc, ini);
2257 
2258 	/* get vlan id from IP device */
2259 	if (smc_vlan_by_tcpsk(new_smc->clcsock, ini))
2260 		return ini->rc ?: SMC_CLC_DECL_GETVLANERR;
2261 
2262 	/* check for ISM device matching V1 proposed device */
2263 	if (!prfx_rc)
2264 		smc_find_ism_v1_device_serv(new_smc, pclc, ini);
2265 	if (ini->ism_dev[0])
2266 		return 0;
2267 
2268 	if (!smcr_indicated(pclc->hdr.typev1) &&
2269 	    !smcr_indicated(pclc->hdr.typev2))
2270 		/* skip RDMA and decline */
2271 		return ini->rc ?: SMC_CLC_DECL_NOSMCDDEV;
2272 
2273 	/* check if RDMA V2 is available */
2274 	smc_find_rdma_v2_device_serv(new_smc, pclc, ini);
2275 	if (ini->smcrv2.ib_dev_v2)
2276 		return 0;
2277 
2278 	/* check if RDMA V1 is available */
2279 	if (!prfx_rc) {
2280 		int rc;
2281 
2282 		rc = smc_find_rdma_v1_device_serv(new_smc, pclc, ini);
2283 		smc_find_ism_store_rc(rc, ini);
2284 		return (!rc) ? 0 : ini->rc;
2285 	}
2286 	return SMC_CLC_DECL_NOSMCDEV;
2287 }
2288 
2289 /* listen worker: finish RDMA setup */
2290 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
2291 				  struct smc_clc_msg_accept_confirm *cclc,
2292 				  bool local_first,
2293 				  struct smc_init_info *ini)
2294 {
2295 	struct smc_link *link = new_smc->conn.lnk;
2296 	int reason_code = 0;
2297 
2298 	if (local_first)
2299 		smc_link_save_peer_info(link, cclc, ini);
2300 
2301 	if (smc_rmb_rtoken_handling(&new_smc->conn, link, cclc))
2302 		return SMC_CLC_DECL_ERR_RTOK;
2303 
2304 	if (local_first) {
2305 		if (smc_ib_ready_link(link))
2306 			return SMC_CLC_DECL_ERR_RDYLNK;
2307 		/* QP confirmation over RoCE fabric */
2308 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
2309 		reason_code = smcr_serv_conf_first_link(new_smc);
2310 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
2311 	}
2312 	return reason_code;
2313 }
2314 
2315 /* setup for connection of server */
2316 static void smc_listen_work(struct work_struct *work)
2317 {
2318 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
2319 						smc_listen_work);
2320 	struct socket *newclcsock = new_smc->clcsock;
2321 	struct smc_clc_msg_accept_confirm *cclc;
2322 	struct smc_clc_msg_proposal_area *buf;
2323 	struct smc_clc_msg_proposal *pclc;
2324 	struct smc_init_info *ini = NULL;
2325 	u8 proposal_version = SMC_V1;
2326 	u8 accept_version;
2327 	int rc = 0;
2328 
2329 	if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
2330 		return smc_listen_out_err(new_smc);
2331 
2332 	if (new_smc->use_fallback) {
2333 		smc_listen_out_connected(new_smc);
2334 		return;
2335 	}
2336 
2337 	/* check if peer is smc capable */
2338 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
2339 		rc = smc_switch_to_fallback(new_smc, SMC_CLC_DECL_PEERNOSMC);
2340 		if (rc)
2341 			smc_listen_out_err(new_smc);
2342 		else
2343 			smc_listen_out_connected(new_smc);
2344 		return;
2345 	}
2346 
2347 	/* do inband token exchange -
2348 	 * wait for and receive SMC Proposal CLC message
2349 	 */
2350 	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
2351 	if (!buf) {
2352 		rc = SMC_CLC_DECL_MEM;
2353 		goto out_decl;
2354 	}
2355 	pclc = (struct smc_clc_msg_proposal *)buf;
2356 	rc = smc_clc_wait_msg(new_smc, pclc, sizeof(*buf),
2357 			      SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
2358 	if (rc)
2359 		goto out_decl;
2360 
2361 	if (pclc->hdr.version > SMC_V1)
2362 		proposal_version = SMC_V2;
2363 
2364 	/* IPSec connections opt out of SMC optimizations */
2365 	if (using_ipsec(new_smc)) {
2366 		rc = SMC_CLC_DECL_IPSEC;
2367 		goto out_decl;
2368 	}
2369 
2370 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
2371 	if (!ini) {
2372 		rc = SMC_CLC_DECL_MEM;
2373 		goto out_decl;
2374 	}
2375 
2376 	/* initial version checking */
2377 	rc = smc_listen_v2_check(new_smc, pclc, ini);
2378 	if (rc)
2379 		goto out_decl;
2380 
2381 	mutex_lock(&smc_server_lgr_pending);
2382 	smc_close_init(new_smc);
2383 	smc_rx_init(new_smc);
2384 	smc_tx_init(new_smc);
2385 
2386 	/* determine ISM or RoCE device used for connection */
2387 	rc = smc_listen_find_device(new_smc, pclc, ini);
2388 	if (rc)
2389 		goto out_unlock;
2390 
2391 	/* send SMC Accept CLC message */
2392 	accept_version = ini->is_smcd ? ini->smcd_version : ini->smcr_version;
2393 	rc = smc_clc_send_accept(new_smc, ini->first_contact_local,
2394 				 accept_version, ini->negotiated_eid);
2395 	if (rc)
2396 		goto out_unlock;
2397 
2398 	/* SMC-D does not need this lock any more */
2399 	if (ini->is_smcd)
2400 		mutex_unlock(&smc_server_lgr_pending);
2401 
2402 	/* receive SMC Confirm CLC message */
2403 	memset(buf, 0, sizeof(*buf));
2404 	cclc = (struct smc_clc_msg_accept_confirm *)buf;
2405 	rc = smc_clc_wait_msg(new_smc, cclc, sizeof(*buf),
2406 			      SMC_CLC_CONFIRM, CLC_WAIT_TIME);
2407 	if (rc) {
2408 		if (!ini->is_smcd)
2409 			goto out_unlock;
2410 		goto out_decl;
2411 	}
2412 
2413 	/* finish worker */
2414 	if (!ini->is_smcd) {
2415 		rc = smc_listen_rdma_finish(new_smc, cclc,
2416 					    ini->first_contact_local, ini);
2417 		if (rc)
2418 			goto out_unlock;
2419 		mutex_unlock(&smc_server_lgr_pending);
2420 	}
2421 	smc_conn_save_peer_info(new_smc, cclc);
2422 	smc_listen_out_connected(new_smc);
2423 	SMC_STAT_SERV_SUCC_INC(sock_net(newclcsock->sk), ini);
2424 	goto out_free;
2425 
2426 out_unlock:
2427 	mutex_unlock(&smc_server_lgr_pending);
2428 out_decl:
2429 	smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0,
2430 			   proposal_version);
2431 out_free:
2432 	kfree(ini);
2433 	kfree(buf);
2434 }
2435 
2436 static void smc_tcp_listen_work(struct work_struct *work)
2437 {
2438 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
2439 					     tcp_listen_work);
2440 	struct sock *lsk = &lsmc->sk;
2441 	struct smc_sock *new_smc;
2442 	int rc = 0;
2443 
2444 	lock_sock(lsk);
2445 	while (lsk->sk_state == SMC_LISTEN) {
2446 		rc = smc_clcsock_accept(lsmc, &new_smc);
2447 		if (rc) /* clcsock accept queue empty or error */
2448 			goto out;
2449 		if (!new_smc)
2450 			continue;
2451 
2452 		if (tcp_sk(new_smc->clcsock->sk)->syn_smc)
2453 			atomic_inc(&lsmc->queued_smc_hs);
2454 
2455 		new_smc->listen_smc = lsmc;
2456 		new_smc->use_fallback = lsmc->use_fallback;
2457 		new_smc->fallback_rsn = lsmc->fallback_rsn;
2458 		sock_hold(lsk); /* sock_put in smc_listen_work */
2459 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
2460 		smc_copy_sock_settings_to_smc(new_smc);
2461 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
2462 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
2463 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
2464 		if (!queue_work(smc_hs_wq, &new_smc->smc_listen_work))
2465 			sock_put(&new_smc->sk);
2466 	}
2467 
2468 out:
2469 	release_sock(lsk);
2470 	sock_put(&lsmc->sk); /* sock_hold in smc_clcsock_data_ready() */
2471 }
2472 
2473 static void smc_clcsock_data_ready(struct sock *listen_clcsock)
2474 {
2475 	struct smc_sock *lsmc;
2476 
2477 	read_lock_bh(&listen_clcsock->sk_callback_lock);
2478 	lsmc = smc_clcsock_user_data(listen_clcsock);
2479 	if (!lsmc)
2480 		goto out;
2481 	lsmc->clcsk_data_ready(listen_clcsock);
2482 	if (lsmc->sk.sk_state == SMC_LISTEN) {
2483 		sock_hold(&lsmc->sk); /* sock_put in smc_tcp_listen_work() */
2484 		if (!queue_work(smc_tcp_ls_wq, &lsmc->tcp_listen_work))
2485 			sock_put(&lsmc->sk);
2486 	}
2487 out:
2488 	read_unlock_bh(&listen_clcsock->sk_callback_lock);
2489 }
2490 
2491 static int smc_listen(struct socket *sock, int backlog)
2492 {
2493 	struct sock *sk = sock->sk;
2494 	struct smc_sock *smc;
2495 	int rc;
2496 
2497 	smc = smc_sk(sk);
2498 	lock_sock(sk);
2499 
2500 	rc = -EINVAL;
2501 	if ((sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) ||
2502 	    smc->connect_nonblock || sock->state != SS_UNCONNECTED)
2503 		goto out;
2504 
2505 	rc = 0;
2506 	if (sk->sk_state == SMC_LISTEN) {
2507 		sk->sk_max_ack_backlog = backlog;
2508 		goto out;
2509 	}
2510 	/* some socket options are handled in core, so we could not apply
2511 	 * them to the clc socket -- copy smc socket options to clc socket
2512 	 */
2513 	smc_copy_sock_settings_to_clc(smc);
2514 	if (!smc->use_fallback)
2515 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
2516 
2517 	/* save original sk_data_ready function and establish
2518 	 * smc-specific sk_data_ready function
2519 	 */
2520 	write_lock_bh(&smc->clcsock->sk->sk_callback_lock);
2521 	smc->clcsock->sk->sk_user_data =
2522 		(void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
2523 	smc_clcsock_replace_cb(&smc->clcsock->sk->sk_data_ready,
2524 			       smc_clcsock_data_ready, &smc->clcsk_data_ready);
2525 	write_unlock_bh(&smc->clcsock->sk->sk_callback_lock);
2526 
2527 	/* save original ops */
2528 	smc->ori_af_ops = inet_csk(smc->clcsock->sk)->icsk_af_ops;
2529 
2530 	smc->af_ops = *smc->ori_af_ops;
2531 	smc->af_ops.syn_recv_sock = smc_tcp_syn_recv_sock;
2532 
2533 	inet_csk(smc->clcsock->sk)->icsk_af_ops = &smc->af_ops;
2534 
2535 	if (smc->limit_smc_hs)
2536 		tcp_sk(smc->clcsock->sk)->smc_hs_congested = smc_hs_congested;
2537 
2538 	rc = kernel_listen(smc->clcsock, backlog);
2539 	if (rc) {
2540 		write_lock_bh(&smc->clcsock->sk->sk_callback_lock);
2541 		smc_clcsock_restore_cb(&smc->clcsock->sk->sk_data_ready,
2542 				       &smc->clcsk_data_ready);
2543 		smc->clcsock->sk->sk_user_data = NULL;
2544 		write_unlock_bh(&smc->clcsock->sk->sk_callback_lock);
2545 		goto out;
2546 	}
2547 	sk->sk_max_ack_backlog = backlog;
2548 	sk->sk_ack_backlog = 0;
2549 	sk->sk_state = SMC_LISTEN;
2550 
2551 out:
2552 	release_sock(sk);
2553 	return rc;
2554 }
2555 
2556 static int smc_accept(struct socket *sock, struct socket *new_sock,
2557 		      int flags, bool kern)
2558 {
2559 	struct sock *sk = sock->sk, *nsk;
2560 	DECLARE_WAITQUEUE(wait, current);
2561 	struct smc_sock *lsmc;
2562 	long timeo;
2563 	int rc = 0;
2564 
2565 	lsmc = smc_sk(sk);
2566 	sock_hold(sk); /* sock_put below */
2567 	lock_sock(sk);
2568 
2569 	if (lsmc->sk.sk_state != SMC_LISTEN) {
2570 		rc = -EINVAL;
2571 		release_sock(sk);
2572 		goto out;
2573 	}
2574 
2575 	/* Wait for an incoming connection */
2576 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
2577 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
2578 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
2579 		set_current_state(TASK_INTERRUPTIBLE);
2580 		if (!timeo) {
2581 			rc = -EAGAIN;
2582 			break;
2583 		}
2584 		release_sock(sk);
2585 		timeo = schedule_timeout(timeo);
2586 		/* wakeup by sk_data_ready in smc_listen_work() */
2587 		sched_annotate_sleep();
2588 		lock_sock(sk);
2589 		if (signal_pending(current)) {
2590 			rc = sock_intr_errno(timeo);
2591 			break;
2592 		}
2593 	}
2594 	set_current_state(TASK_RUNNING);
2595 	remove_wait_queue(sk_sleep(sk), &wait);
2596 
2597 	if (!rc)
2598 		rc = sock_error(nsk);
2599 	release_sock(sk);
2600 	if (rc)
2601 		goto out;
2602 
2603 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
2604 		/* wait till data arrives on the socket */
2605 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
2606 								MSEC_PER_SEC);
2607 		if (smc_sk(nsk)->use_fallback) {
2608 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
2609 
2610 			lock_sock(clcsk);
2611 			if (skb_queue_empty(&clcsk->sk_receive_queue))
2612 				sk_wait_data(clcsk, &timeo, NULL);
2613 			release_sock(clcsk);
2614 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
2615 			lock_sock(nsk);
2616 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
2617 			release_sock(nsk);
2618 		}
2619 	}
2620 
2621 out:
2622 	sock_put(sk); /* sock_hold above */
2623 	return rc;
2624 }
2625 
2626 static int smc_getname(struct socket *sock, struct sockaddr *addr,
2627 		       int peer)
2628 {
2629 	struct smc_sock *smc;
2630 
2631 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
2632 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
2633 		return -ENOTCONN;
2634 
2635 	smc = smc_sk(sock->sk);
2636 
2637 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
2638 }
2639 
2640 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2641 {
2642 	struct sock *sk = sock->sk;
2643 	struct smc_sock *smc;
2644 	int rc = -EPIPE;
2645 
2646 	smc = smc_sk(sk);
2647 	lock_sock(sk);
2648 	if ((sk->sk_state != SMC_ACTIVE) &&
2649 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2650 	    (sk->sk_state != SMC_INIT))
2651 		goto out;
2652 
2653 	if (msg->msg_flags & MSG_FASTOPEN) {
2654 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2655 			rc = smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2656 			if (rc)
2657 				goto out;
2658 		} else {
2659 			rc = -EINVAL;
2660 			goto out;
2661 		}
2662 	}
2663 
2664 	if (smc->use_fallback) {
2665 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
2666 	} else {
2667 		rc = smc_tx_sendmsg(smc, msg, len);
2668 		SMC_STAT_TX_PAYLOAD(smc, len, rc);
2669 	}
2670 out:
2671 	release_sock(sk);
2672 	return rc;
2673 }
2674 
2675 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2676 		       int flags)
2677 {
2678 	struct sock *sk = sock->sk;
2679 	struct smc_sock *smc;
2680 	int rc = -ENOTCONN;
2681 
2682 	smc = smc_sk(sk);
2683 	lock_sock(sk);
2684 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2685 		/* socket was connected before, no more data to read */
2686 		rc = 0;
2687 		goto out;
2688 	}
2689 	if ((sk->sk_state == SMC_INIT) ||
2690 	    (sk->sk_state == SMC_LISTEN) ||
2691 	    (sk->sk_state == SMC_CLOSED))
2692 		goto out;
2693 
2694 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2695 		rc = 0;
2696 		goto out;
2697 	}
2698 
2699 	if (smc->use_fallback) {
2700 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
2701 	} else {
2702 		msg->msg_namelen = 0;
2703 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
2704 		SMC_STAT_RX_PAYLOAD(smc, rc, rc);
2705 	}
2706 
2707 out:
2708 	release_sock(sk);
2709 	return rc;
2710 }
2711 
2712 static __poll_t smc_accept_poll(struct sock *parent)
2713 {
2714 	struct smc_sock *isk = smc_sk(parent);
2715 	__poll_t mask = 0;
2716 
2717 	spin_lock(&isk->accept_q_lock);
2718 	if (!list_empty(&isk->accept_q))
2719 		mask = EPOLLIN | EPOLLRDNORM;
2720 	spin_unlock(&isk->accept_q_lock);
2721 
2722 	return mask;
2723 }
2724 
2725 static __poll_t smc_poll(struct file *file, struct socket *sock,
2726 			     poll_table *wait)
2727 {
2728 	struct sock *sk = sock->sk;
2729 	struct smc_sock *smc;
2730 	__poll_t mask = 0;
2731 
2732 	if (!sk)
2733 		return EPOLLNVAL;
2734 
2735 	smc = smc_sk(sock->sk);
2736 	if (smc->use_fallback) {
2737 		/* delegate to CLC child sock */
2738 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
2739 		sk->sk_err = smc->clcsock->sk->sk_err;
2740 	} else {
2741 		if (sk->sk_state != SMC_CLOSED)
2742 			sock_poll_wait(file, sock, wait);
2743 		if (sk->sk_err)
2744 			mask |= EPOLLERR;
2745 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
2746 		    (sk->sk_state == SMC_CLOSED))
2747 			mask |= EPOLLHUP;
2748 		if (sk->sk_state == SMC_LISTEN) {
2749 			/* woken up by sk_data_ready in smc_listen_work() */
2750 			mask |= smc_accept_poll(sk);
2751 		} else if (smc->use_fallback) { /* as result of connect_work()*/
2752 			mask |= smc->clcsock->ops->poll(file, smc->clcsock,
2753 							   wait);
2754 			sk->sk_err = smc->clcsock->sk->sk_err;
2755 		} else {
2756 			if ((sk->sk_state != SMC_INIT &&
2757 			     atomic_read(&smc->conn.sndbuf_space)) ||
2758 			    sk->sk_shutdown & SEND_SHUTDOWN) {
2759 				mask |= EPOLLOUT | EPOLLWRNORM;
2760 			} else {
2761 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2762 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2763 			}
2764 			if (atomic_read(&smc->conn.bytes_to_rcv))
2765 				mask |= EPOLLIN | EPOLLRDNORM;
2766 			if (sk->sk_shutdown & RCV_SHUTDOWN)
2767 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
2768 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
2769 				mask |= EPOLLIN;
2770 			if (smc->conn.urg_state == SMC_URG_VALID)
2771 				mask |= EPOLLPRI;
2772 		}
2773 	}
2774 
2775 	return mask;
2776 }
2777 
2778 static int smc_shutdown(struct socket *sock, int how)
2779 {
2780 	struct sock *sk = sock->sk;
2781 	bool do_shutdown = true;
2782 	struct smc_sock *smc;
2783 	int rc = -EINVAL;
2784 	int old_state;
2785 	int rc1 = 0;
2786 
2787 	smc = smc_sk(sk);
2788 
2789 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
2790 		return rc;
2791 
2792 	lock_sock(sk);
2793 
2794 	if (sock->state == SS_CONNECTING) {
2795 		if (sk->sk_state == SMC_ACTIVE)
2796 			sock->state = SS_CONNECTED;
2797 		else if (sk->sk_state == SMC_PEERCLOSEWAIT1 ||
2798 			 sk->sk_state == SMC_PEERCLOSEWAIT2 ||
2799 			 sk->sk_state == SMC_APPCLOSEWAIT1 ||
2800 			 sk->sk_state == SMC_APPCLOSEWAIT2 ||
2801 			 sk->sk_state == SMC_APPFINCLOSEWAIT)
2802 			sock->state = SS_DISCONNECTING;
2803 	}
2804 
2805 	rc = -ENOTCONN;
2806 	if ((sk->sk_state != SMC_ACTIVE) &&
2807 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
2808 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
2809 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2810 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
2811 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
2812 		goto out;
2813 	if (smc->use_fallback) {
2814 		rc = kernel_sock_shutdown(smc->clcsock, how);
2815 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
2816 		if (sk->sk_shutdown == SHUTDOWN_MASK) {
2817 			sk->sk_state = SMC_CLOSED;
2818 			sk->sk_socket->state = SS_UNCONNECTED;
2819 			sock_put(sk);
2820 		}
2821 		goto out;
2822 	}
2823 	switch (how) {
2824 	case SHUT_RDWR:		/* shutdown in both directions */
2825 		old_state = sk->sk_state;
2826 		rc = smc_close_active(smc);
2827 		if (old_state == SMC_ACTIVE &&
2828 		    sk->sk_state == SMC_PEERCLOSEWAIT1)
2829 			do_shutdown = false;
2830 		break;
2831 	case SHUT_WR:
2832 		rc = smc_close_shutdown_write(smc);
2833 		break;
2834 	case SHUT_RD:
2835 		rc = 0;
2836 		/* nothing more to do because peer is not involved */
2837 		break;
2838 	}
2839 	if (do_shutdown && smc->clcsock)
2840 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
2841 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
2842 	sk->sk_shutdown |= how + 1;
2843 
2844 	if (sk->sk_state == SMC_CLOSED)
2845 		sock->state = SS_UNCONNECTED;
2846 	else
2847 		sock->state = SS_DISCONNECTING;
2848 out:
2849 	release_sock(sk);
2850 	return rc ? rc : rc1;
2851 }
2852 
2853 static int __smc_getsockopt(struct socket *sock, int level, int optname,
2854 			    char __user *optval, int __user *optlen)
2855 {
2856 	struct smc_sock *smc;
2857 	int val, len;
2858 
2859 	smc = smc_sk(sock->sk);
2860 
2861 	if (get_user(len, optlen))
2862 		return -EFAULT;
2863 
2864 	len = min_t(int, len, sizeof(int));
2865 
2866 	if (len < 0)
2867 		return -EINVAL;
2868 
2869 	switch (optname) {
2870 	case SMC_LIMIT_HS:
2871 		val = smc->limit_smc_hs;
2872 		break;
2873 	default:
2874 		return -EOPNOTSUPP;
2875 	}
2876 
2877 	if (put_user(len, optlen))
2878 		return -EFAULT;
2879 	if (copy_to_user(optval, &val, len))
2880 		return -EFAULT;
2881 
2882 	return 0;
2883 }
2884 
2885 static int __smc_setsockopt(struct socket *sock, int level, int optname,
2886 			    sockptr_t optval, unsigned int optlen)
2887 {
2888 	struct sock *sk = sock->sk;
2889 	struct smc_sock *smc;
2890 	int val, rc;
2891 
2892 	smc = smc_sk(sk);
2893 
2894 	lock_sock(sk);
2895 	switch (optname) {
2896 	case SMC_LIMIT_HS:
2897 		if (optlen < sizeof(int)) {
2898 			rc = -EINVAL;
2899 			break;
2900 		}
2901 		if (copy_from_sockptr(&val, optval, sizeof(int))) {
2902 			rc = -EFAULT;
2903 			break;
2904 		}
2905 
2906 		smc->limit_smc_hs = !!val;
2907 		rc = 0;
2908 		break;
2909 	default:
2910 		rc = -EOPNOTSUPP;
2911 		break;
2912 	}
2913 	release_sock(sk);
2914 
2915 	return rc;
2916 }
2917 
2918 static int smc_setsockopt(struct socket *sock, int level, int optname,
2919 			  sockptr_t optval, unsigned int optlen)
2920 {
2921 	struct sock *sk = sock->sk;
2922 	struct smc_sock *smc;
2923 	int val, rc;
2924 
2925 	if (level == SOL_TCP && optname == TCP_ULP)
2926 		return -EOPNOTSUPP;
2927 	else if (level == SOL_SMC)
2928 		return __smc_setsockopt(sock, level, optname, optval, optlen);
2929 
2930 	smc = smc_sk(sk);
2931 
2932 	/* generic setsockopts reaching us here always apply to the
2933 	 * CLC socket
2934 	 */
2935 	mutex_lock(&smc->clcsock_release_lock);
2936 	if (!smc->clcsock) {
2937 		mutex_unlock(&smc->clcsock_release_lock);
2938 		return -EBADF;
2939 	}
2940 	if (unlikely(!smc->clcsock->ops->setsockopt))
2941 		rc = -EOPNOTSUPP;
2942 	else
2943 		rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
2944 						   optval, optlen);
2945 	if (smc->clcsock->sk->sk_err) {
2946 		sk->sk_err = smc->clcsock->sk->sk_err;
2947 		sk_error_report(sk);
2948 	}
2949 	mutex_unlock(&smc->clcsock_release_lock);
2950 
2951 	if (optlen < sizeof(int))
2952 		return -EINVAL;
2953 	if (copy_from_sockptr(&val, optval, sizeof(int)))
2954 		return -EFAULT;
2955 
2956 	lock_sock(sk);
2957 	if (rc || smc->use_fallback)
2958 		goto out;
2959 	switch (optname) {
2960 	case TCP_FASTOPEN:
2961 	case TCP_FASTOPEN_CONNECT:
2962 	case TCP_FASTOPEN_KEY:
2963 	case TCP_FASTOPEN_NO_COOKIE:
2964 		/* option not supported by SMC */
2965 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2966 			rc = smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2967 		} else {
2968 			rc = -EINVAL;
2969 		}
2970 		break;
2971 	case TCP_NODELAY:
2972 		if (sk->sk_state != SMC_INIT &&
2973 		    sk->sk_state != SMC_LISTEN &&
2974 		    sk->sk_state != SMC_CLOSED) {
2975 			if (val) {
2976 				SMC_STAT_INC(smc, ndly_cnt);
2977 				smc_tx_pending(&smc->conn);
2978 				cancel_delayed_work(&smc->conn.tx_work);
2979 			}
2980 		}
2981 		break;
2982 	case TCP_CORK:
2983 		if (sk->sk_state != SMC_INIT &&
2984 		    sk->sk_state != SMC_LISTEN &&
2985 		    sk->sk_state != SMC_CLOSED) {
2986 			if (!val) {
2987 				SMC_STAT_INC(smc, cork_cnt);
2988 				smc_tx_pending(&smc->conn);
2989 				cancel_delayed_work(&smc->conn.tx_work);
2990 			}
2991 		}
2992 		break;
2993 	case TCP_DEFER_ACCEPT:
2994 		smc->sockopt_defer_accept = val;
2995 		break;
2996 	default:
2997 		break;
2998 	}
2999 out:
3000 	release_sock(sk);
3001 
3002 	return rc;
3003 }
3004 
3005 static int smc_getsockopt(struct socket *sock, int level, int optname,
3006 			  char __user *optval, int __user *optlen)
3007 {
3008 	struct smc_sock *smc;
3009 	int rc;
3010 
3011 	if (level == SOL_SMC)
3012 		return __smc_getsockopt(sock, level, optname, optval, optlen);
3013 
3014 	smc = smc_sk(sock->sk);
3015 	mutex_lock(&smc->clcsock_release_lock);
3016 	if (!smc->clcsock) {
3017 		mutex_unlock(&smc->clcsock_release_lock);
3018 		return -EBADF;
3019 	}
3020 	/* socket options apply to the CLC socket */
3021 	if (unlikely(!smc->clcsock->ops->getsockopt)) {
3022 		mutex_unlock(&smc->clcsock_release_lock);
3023 		return -EOPNOTSUPP;
3024 	}
3025 	rc = smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
3026 					   optval, optlen);
3027 	mutex_unlock(&smc->clcsock_release_lock);
3028 	return rc;
3029 }
3030 
3031 static int smc_ioctl(struct socket *sock, unsigned int cmd,
3032 		     unsigned long arg)
3033 {
3034 	union smc_host_cursor cons, urg;
3035 	struct smc_connection *conn;
3036 	struct smc_sock *smc;
3037 	int answ;
3038 
3039 	smc = smc_sk(sock->sk);
3040 	conn = &smc->conn;
3041 	lock_sock(&smc->sk);
3042 	if (smc->use_fallback) {
3043 		if (!smc->clcsock) {
3044 			release_sock(&smc->sk);
3045 			return -EBADF;
3046 		}
3047 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
3048 		release_sock(&smc->sk);
3049 		return answ;
3050 	}
3051 	switch (cmd) {
3052 	case SIOCINQ: /* same as FIONREAD */
3053 		if (smc->sk.sk_state == SMC_LISTEN) {
3054 			release_sock(&smc->sk);
3055 			return -EINVAL;
3056 		}
3057 		if (smc->sk.sk_state == SMC_INIT ||
3058 		    smc->sk.sk_state == SMC_CLOSED)
3059 			answ = 0;
3060 		else
3061 			answ = atomic_read(&smc->conn.bytes_to_rcv);
3062 		break;
3063 	case SIOCOUTQ:
3064 		/* output queue size (not send + not acked) */
3065 		if (smc->sk.sk_state == SMC_LISTEN) {
3066 			release_sock(&smc->sk);
3067 			return -EINVAL;
3068 		}
3069 		if (smc->sk.sk_state == SMC_INIT ||
3070 		    smc->sk.sk_state == SMC_CLOSED)
3071 			answ = 0;
3072 		else
3073 			answ = smc->conn.sndbuf_desc->len -
3074 					atomic_read(&smc->conn.sndbuf_space);
3075 		break;
3076 	case SIOCOUTQNSD:
3077 		/* output queue size (not send only) */
3078 		if (smc->sk.sk_state == SMC_LISTEN) {
3079 			release_sock(&smc->sk);
3080 			return -EINVAL;
3081 		}
3082 		if (smc->sk.sk_state == SMC_INIT ||
3083 		    smc->sk.sk_state == SMC_CLOSED)
3084 			answ = 0;
3085 		else
3086 			answ = smc_tx_prepared_sends(&smc->conn);
3087 		break;
3088 	case SIOCATMARK:
3089 		if (smc->sk.sk_state == SMC_LISTEN) {
3090 			release_sock(&smc->sk);
3091 			return -EINVAL;
3092 		}
3093 		if (smc->sk.sk_state == SMC_INIT ||
3094 		    smc->sk.sk_state == SMC_CLOSED) {
3095 			answ = 0;
3096 		} else {
3097 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
3098 			smc_curs_copy(&urg, &conn->urg_curs, conn);
3099 			answ = smc_curs_diff(conn->rmb_desc->len,
3100 					     &cons, &urg) == 1;
3101 		}
3102 		break;
3103 	default:
3104 		release_sock(&smc->sk);
3105 		return -ENOIOCTLCMD;
3106 	}
3107 	release_sock(&smc->sk);
3108 
3109 	return put_user(answ, (int __user *)arg);
3110 }
3111 
3112 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
3113 			    int offset, size_t size, int flags)
3114 {
3115 	struct sock *sk = sock->sk;
3116 	struct smc_sock *smc;
3117 	int rc = -EPIPE;
3118 
3119 	smc = smc_sk(sk);
3120 	lock_sock(sk);
3121 	if (sk->sk_state != SMC_ACTIVE) {
3122 		release_sock(sk);
3123 		goto out;
3124 	}
3125 	release_sock(sk);
3126 	if (smc->use_fallback) {
3127 		rc = kernel_sendpage(smc->clcsock, page, offset,
3128 				     size, flags);
3129 	} else {
3130 		lock_sock(sk);
3131 		rc = smc_tx_sendpage(smc, page, offset, size, flags);
3132 		release_sock(sk);
3133 		SMC_STAT_INC(smc, sendpage_cnt);
3134 	}
3135 
3136 out:
3137 	return rc;
3138 }
3139 
3140 /* Map the affected portions of the rmbe into an spd, note the number of bytes
3141  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
3142  * updates till whenever a respective page has been fully processed.
3143  * Note that subsequent recv() calls have to wait till all splice() processing
3144  * completed.
3145  */
3146 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
3147 			       struct pipe_inode_info *pipe, size_t len,
3148 			       unsigned int flags)
3149 {
3150 	struct sock *sk = sock->sk;
3151 	struct smc_sock *smc;
3152 	int rc = -ENOTCONN;
3153 
3154 	smc = smc_sk(sk);
3155 	lock_sock(sk);
3156 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
3157 		/* socket was connected before, no more data to read */
3158 		rc = 0;
3159 		goto out;
3160 	}
3161 	if (sk->sk_state == SMC_INIT ||
3162 	    sk->sk_state == SMC_LISTEN ||
3163 	    sk->sk_state == SMC_CLOSED)
3164 		goto out;
3165 
3166 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
3167 		rc = 0;
3168 		goto out;
3169 	}
3170 
3171 	if (smc->use_fallback) {
3172 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
3173 						    pipe, len, flags);
3174 	} else {
3175 		if (*ppos) {
3176 			rc = -ESPIPE;
3177 			goto out;
3178 		}
3179 		if (flags & SPLICE_F_NONBLOCK)
3180 			flags = MSG_DONTWAIT;
3181 		else
3182 			flags = 0;
3183 		SMC_STAT_INC(smc, splice_cnt);
3184 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
3185 	}
3186 out:
3187 	release_sock(sk);
3188 
3189 	return rc;
3190 }
3191 
3192 /* must look like tcp */
3193 static const struct proto_ops smc_sock_ops = {
3194 	.family		= PF_SMC,
3195 	.owner		= THIS_MODULE,
3196 	.release	= smc_release,
3197 	.bind		= smc_bind,
3198 	.connect	= smc_connect,
3199 	.socketpair	= sock_no_socketpair,
3200 	.accept		= smc_accept,
3201 	.getname	= smc_getname,
3202 	.poll		= smc_poll,
3203 	.ioctl		= smc_ioctl,
3204 	.listen		= smc_listen,
3205 	.shutdown	= smc_shutdown,
3206 	.setsockopt	= smc_setsockopt,
3207 	.getsockopt	= smc_getsockopt,
3208 	.sendmsg	= smc_sendmsg,
3209 	.recvmsg	= smc_recvmsg,
3210 	.mmap		= sock_no_mmap,
3211 	.sendpage	= smc_sendpage,
3212 	.splice_read	= smc_splice_read,
3213 };
3214 
3215 static int __smc_create(struct net *net, struct socket *sock, int protocol,
3216 			int kern, struct socket *clcsock)
3217 {
3218 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
3219 	struct smc_sock *smc;
3220 	struct sock *sk;
3221 	int rc;
3222 
3223 	rc = -ESOCKTNOSUPPORT;
3224 	if (sock->type != SOCK_STREAM)
3225 		goto out;
3226 
3227 	rc = -EPROTONOSUPPORT;
3228 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
3229 		goto out;
3230 
3231 	rc = -ENOBUFS;
3232 	sock->ops = &smc_sock_ops;
3233 	sock->state = SS_UNCONNECTED;
3234 	sk = smc_sock_alloc(net, sock, protocol);
3235 	if (!sk)
3236 		goto out;
3237 
3238 	/* create internal TCP socket for CLC handshake and fallback */
3239 	smc = smc_sk(sk);
3240 	smc->use_fallback = false; /* assume rdma capability first */
3241 	smc->fallback_rsn = 0;
3242 
3243 	/* default behavior from limit_smc_hs in every net namespace */
3244 	smc->limit_smc_hs = net->smc.limit_smc_hs;
3245 
3246 	rc = 0;
3247 	if (!clcsock) {
3248 		rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
3249 				      &smc->clcsock);
3250 		if (rc) {
3251 			sk_common_release(sk);
3252 			goto out;
3253 		}
3254 	} else {
3255 		smc->clcsock = clcsock;
3256 	}
3257 
3258 out:
3259 	return rc;
3260 }
3261 
3262 static int smc_create(struct net *net, struct socket *sock, int protocol,
3263 		      int kern)
3264 {
3265 	return __smc_create(net, sock, protocol, kern, NULL);
3266 }
3267 
3268 static const struct net_proto_family smc_sock_family_ops = {
3269 	.family	= PF_SMC,
3270 	.owner	= THIS_MODULE,
3271 	.create	= smc_create,
3272 };
3273 
3274 static int smc_ulp_init(struct sock *sk)
3275 {
3276 	struct socket *tcp = sk->sk_socket;
3277 	struct net *net = sock_net(sk);
3278 	struct socket *smcsock;
3279 	int protocol, ret;
3280 
3281 	/* only TCP can be replaced */
3282 	if (tcp->type != SOCK_STREAM || sk->sk_protocol != IPPROTO_TCP ||
3283 	    (sk->sk_family != AF_INET && sk->sk_family != AF_INET6))
3284 		return -ESOCKTNOSUPPORT;
3285 	/* don't handle wq now */
3286 	if (tcp->state != SS_UNCONNECTED || !tcp->file || tcp->wq.fasync_list)
3287 		return -ENOTCONN;
3288 
3289 	if (sk->sk_family == AF_INET)
3290 		protocol = SMCPROTO_SMC;
3291 	else
3292 		protocol = SMCPROTO_SMC6;
3293 
3294 	smcsock = sock_alloc();
3295 	if (!smcsock)
3296 		return -ENFILE;
3297 
3298 	smcsock->type = SOCK_STREAM;
3299 	__module_get(THIS_MODULE); /* tried in __tcp_ulp_find_autoload */
3300 	ret = __smc_create(net, smcsock, protocol, 1, tcp);
3301 	if (ret) {
3302 		sock_release(smcsock); /* module_put() which ops won't be NULL */
3303 		return ret;
3304 	}
3305 
3306 	/* replace tcp socket to smc */
3307 	smcsock->file = tcp->file;
3308 	smcsock->file->private_data = smcsock;
3309 	smcsock->file->f_inode = SOCK_INODE(smcsock); /* replace inode when sock_close */
3310 	smcsock->file->f_path.dentry->d_inode = SOCK_INODE(smcsock); /* dput() in __fput */
3311 	tcp->file = NULL;
3312 
3313 	return ret;
3314 }
3315 
3316 static void smc_ulp_clone(const struct request_sock *req, struct sock *newsk,
3317 			  const gfp_t priority)
3318 {
3319 	struct inet_connection_sock *icsk = inet_csk(newsk);
3320 
3321 	/* don't inherit ulp ops to child when listen */
3322 	icsk->icsk_ulp_ops = NULL;
3323 }
3324 
3325 static struct tcp_ulp_ops smc_ulp_ops __read_mostly = {
3326 	.name		= "smc",
3327 	.owner		= THIS_MODULE,
3328 	.init		= smc_ulp_init,
3329 	.clone		= smc_ulp_clone,
3330 };
3331 
3332 unsigned int smc_net_id;
3333 
3334 static __net_init int smc_net_init(struct net *net)
3335 {
3336 	int rc;
3337 
3338 	rc = smc_sysctl_net_init(net);
3339 	if (rc)
3340 		return rc;
3341 	return smc_pnet_net_init(net);
3342 }
3343 
3344 static void __net_exit smc_net_exit(struct net *net)
3345 {
3346 	smc_sysctl_net_exit(net);
3347 	smc_pnet_net_exit(net);
3348 }
3349 
3350 static __net_init int smc_net_stat_init(struct net *net)
3351 {
3352 	return smc_stats_init(net);
3353 }
3354 
3355 static void __net_exit smc_net_stat_exit(struct net *net)
3356 {
3357 	smc_stats_exit(net);
3358 }
3359 
3360 static struct pernet_operations smc_net_ops = {
3361 	.init = smc_net_init,
3362 	.exit = smc_net_exit,
3363 	.id   = &smc_net_id,
3364 	.size = sizeof(struct smc_net),
3365 };
3366 
3367 static struct pernet_operations smc_net_stat_ops = {
3368 	.init = smc_net_stat_init,
3369 	.exit = smc_net_stat_exit,
3370 };
3371 
3372 static int __init smc_init(void)
3373 {
3374 	int rc;
3375 
3376 	rc = register_pernet_subsys(&smc_net_ops);
3377 	if (rc)
3378 		return rc;
3379 
3380 	rc = register_pernet_subsys(&smc_net_stat_ops);
3381 	if (rc)
3382 		return rc;
3383 
3384 	smc_ism_init();
3385 	smc_clc_init();
3386 
3387 	rc = smc_nl_init();
3388 	if (rc)
3389 		goto out_pernet_subsys;
3390 
3391 	rc = smc_pnet_init();
3392 	if (rc)
3393 		goto out_nl;
3394 
3395 	rc = -ENOMEM;
3396 
3397 	smc_tcp_ls_wq = alloc_workqueue("smc_tcp_ls_wq", 0, 0);
3398 	if (!smc_tcp_ls_wq)
3399 		goto out_pnet;
3400 
3401 	smc_hs_wq = alloc_workqueue("smc_hs_wq", 0, 0);
3402 	if (!smc_hs_wq)
3403 		goto out_alloc_tcp_ls_wq;
3404 
3405 	smc_close_wq = alloc_workqueue("smc_close_wq", 0, 0);
3406 	if (!smc_close_wq)
3407 		goto out_alloc_hs_wq;
3408 
3409 	rc = smc_core_init();
3410 	if (rc) {
3411 		pr_err("%s: smc_core_init fails with %d\n", __func__, rc);
3412 		goto out_alloc_wqs;
3413 	}
3414 
3415 	rc = smc_llc_init();
3416 	if (rc) {
3417 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
3418 		goto out_core;
3419 	}
3420 
3421 	rc = smc_cdc_init();
3422 	if (rc) {
3423 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
3424 		goto out_core;
3425 	}
3426 
3427 	rc = proto_register(&smc_proto, 1);
3428 	if (rc) {
3429 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
3430 		goto out_core;
3431 	}
3432 
3433 	rc = proto_register(&smc_proto6, 1);
3434 	if (rc) {
3435 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
3436 		goto out_proto;
3437 	}
3438 
3439 	rc = sock_register(&smc_sock_family_ops);
3440 	if (rc) {
3441 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
3442 		goto out_proto6;
3443 	}
3444 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
3445 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
3446 
3447 	rc = smc_ib_register_client();
3448 	if (rc) {
3449 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
3450 		goto out_sock;
3451 	}
3452 
3453 	rc = tcp_register_ulp(&smc_ulp_ops);
3454 	if (rc) {
3455 		pr_err("%s: tcp_ulp_register fails with %d\n", __func__, rc);
3456 		goto out_ib;
3457 	}
3458 
3459 	static_branch_enable(&tcp_have_smc);
3460 	return 0;
3461 
3462 out_ib:
3463 	smc_ib_unregister_client();
3464 out_sock:
3465 	sock_unregister(PF_SMC);
3466 out_proto6:
3467 	proto_unregister(&smc_proto6);
3468 out_proto:
3469 	proto_unregister(&smc_proto);
3470 out_core:
3471 	smc_core_exit();
3472 out_alloc_wqs:
3473 	destroy_workqueue(smc_close_wq);
3474 out_alloc_hs_wq:
3475 	destroy_workqueue(smc_hs_wq);
3476 out_alloc_tcp_ls_wq:
3477 	destroy_workqueue(smc_tcp_ls_wq);
3478 out_pnet:
3479 	smc_pnet_exit();
3480 out_nl:
3481 	smc_nl_exit();
3482 out_pernet_subsys:
3483 	unregister_pernet_subsys(&smc_net_ops);
3484 
3485 	return rc;
3486 }
3487 
3488 static void __exit smc_exit(void)
3489 {
3490 	static_branch_disable(&tcp_have_smc);
3491 	tcp_unregister_ulp(&smc_ulp_ops);
3492 	sock_unregister(PF_SMC);
3493 	smc_core_exit();
3494 	smc_ib_unregister_client();
3495 	destroy_workqueue(smc_close_wq);
3496 	destroy_workqueue(smc_tcp_ls_wq);
3497 	destroy_workqueue(smc_hs_wq);
3498 	proto_unregister(&smc_proto6);
3499 	proto_unregister(&smc_proto);
3500 	smc_pnet_exit();
3501 	smc_nl_exit();
3502 	smc_clc_exit();
3503 	unregister_pernet_subsys(&smc_net_stat_ops);
3504 	unregister_pernet_subsys(&smc_net_ops);
3505 	rcu_barrier();
3506 }
3507 
3508 module_init(smc_init);
3509 module_exit(smc_exit);
3510 
3511 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
3512 MODULE_DESCRIPTION("smc socket address family");
3513 MODULE_LICENSE("GPL");
3514 MODULE_ALIAS_NETPROTO(PF_SMC);
3515 MODULE_ALIAS_TCP_ULP("smc");
3516 MODULE_ALIAS_GENL_FAMILY(SMC_GENL_FAMILY_NAME);
3517