xref: /openbmc/linux/net/smc/af_smc.c (revision cef69974)
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_restore_fallback_changes(struct smc_sock *smc)
247 {
248 	if (smc->clcsock->file) { /* non-accepted sockets have no file yet */
249 		smc->clcsock->file->private_data = smc->sk.sk_socket;
250 		smc->clcsock->file = NULL;
251 	}
252 }
253 
254 static int __smc_release(struct smc_sock *smc)
255 {
256 	struct sock *sk = &smc->sk;
257 	int rc = 0;
258 
259 	if (!smc->use_fallback) {
260 		rc = smc_close_active(smc);
261 		sock_set_flag(sk, SOCK_DEAD);
262 		sk->sk_shutdown |= SHUTDOWN_MASK;
263 	} else {
264 		if (sk->sk_state != SMC_CLOSED) {
265 			if (sk->sk_state != SMC_LISTEN &&
266 			    sk->sk_state != SMC_INIT)
267 				sock_put(sk); /* passive closing */
268 			if (sk->sk_state == SMC_LISTEN) {
269 				/* wake up clcsock accept */
270 				rc = kernel_sock_shutdown(smc->clcsock,
271 							  SHUT_RDWR);
272 			}
273 			sk->sk_state = SMC_CLOSED;
274 			sk->sk_state_change(sk);
275 		}
276 		smc_restore_fallback_changes(smc);
277 	}
278 
279 	sk->sk_prot->unhash(sk);
280 
281 	if (sk->sk_state == SMC_CLOSED) {
282 		if (smc->clcsock) {
283 			release_sock(sk);
284 			smc_clcsock_release(smc);
285 			lock_sock(sk);
286 		}
287 		if (!smc->use_fallback)
288 			smc_conn_free(&smc->conn);
289 	}
290 
291 	return rc;
292 }
293 
294 static int smc_release(struct socket *sock)
295 {
296 	struct sock *sk = sock->sk;
297 	struct smc_sock *smc;
298 	int old_state, rc = 0;
299 
300 	if (!sk)
301 		goto out;
302 
303 	sock_hold(sk); /* sock_put below */
304 	smc = smc_sk(sk);
305 
306 	old_state = sk->sk_state;
307 
308 	/* cleanup for a dangling non-blocking connect */
309 	if (smc->connect_nonblock && old_state == SMC_INIT)
310 		tcp_abort(smc->clcsock->sk, ECONNABORTED);
311 
312 	if (cancel_work_sync(&smc->connect_work))
313 		sock_put(&smc->sk); /* sock_hold in smc_connect for passive closing */
314 
315 	if (sk->sk_state == SMC_LISTEN)
316 		/* smc_close_non_accepted() is called and acquires
317 		 * sock lock for child sockets again
318 		 */
319 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
320 	else
321 		lock_sock(sk);
322 
323 	if (old_state == SMC_INIT && sk->sk_state == SMC_ACTIVE &&
324 	    !smc->use_fallback)
325 		smc_close_active_abort(smc);
326 
327 	rc = __smc_release(smc);
328 
329 	/* detach socket */
330 	sock_orphan(sk);
331 	sock->sk = NULL;
332 	release_sock(sk);
333 
334 	sock_put(sk); /* sock_hold above */
335 	sock_put(sk); /* final sock_put */
336 out:
337 	return rc;
338 }
339 
340 static void smc_destruct(struct sock *sk)
341 {
342 	if (sk->sk_state != SMC_CLOSED)
343 		return;
344 	if (!sock_flag(sk, SOCK_DEAD))
345 		return;
346 
347 	sk_refcnt_debug_dec(sk);
348 }
349 
350 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
351 				   int protocol)
352 {
353 	struct smc_sock *smc;
354 	struct proto *prot;
355 	struct sock *sk;
356 
357 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
358 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
359 	if (!sk)
360 		return NULL;
361 
362 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
363 	sk->sk_state = SMC_INIT;
364 	sk->sk_destruct = smc_destruct;
365 	sk->sk_protocol = protocol;
366 	smc = smc_sk(sk);
367 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
368 	INIT_WORK(&smc->connect_work, smc_connect_work);
369 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
370 	INIT_LIST_HEAD(&smc->accept_q);
371 	spin_lock_init(&smc->accept_q_lock);
372 	spin_lock_init(&smc->conn.send_lock);
373 	sk->sk_prot->hash(sk);
374 	sk_refcnt_debug_inc(sk);
375 	mutex_init(&smc->clcsock_release_lock);
376 
377 	return sk;
378 }
379 
380 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
381 		    int addr_len)
382 {
383 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
384 	struct sock *sk = sock->sk;
385 	struct smc_sock *smc;
386 	int rc;
387 
388 	smc = smc_sk(sk);
389 
390 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
391 	rc = -EINVAL;
392 	if (addr_len < sizeof(struct sockaddr_in))
393 		goto out;
394 
395 	rc = -EAFNOSUPPORT;
396 	if (addr->sin_family != AF_INET &&
397 	    addr->sin_family != AF_INET6 &&
398 	    addr->sin_family != AF_UNSPEC)
399 		goto out;
400 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
401 	if (addr->sin_family == AF_UNSPEC &&
402 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
403 		goto out;
404 
405 	lock_sock(sk);
406 
407 	/* Check if socket is already active */
408 	rc = -EINVAL;
409 	if (sk->sk_state != SMC_INIT || smc->connect_nonblock)
410 		goto out_rel;
411 
412 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
413 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
414 
415 out_rel:
416 	release_sock(sk);
417 out:
418 	return rc;
419 }
420 
421 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
422 				   unsigned long mask)
423 {
424 	/* options we don't get control via setsockopt for */
425 	nsk->sk_type = osk->sk_type;
426 	nsk->sk_sndbuf = osk->sk_sndbuf;
427 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
428 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
429 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
430 	nsk->sk_mark = osk->sk_mark;
431 	nsk->sk_priority = osk->sk_priority;
432 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
433 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
434 	nsk->sk_err = osk->sk_err;
435 
436 	nsk->sk_flags &= ~mask;
437 	nsk->sk_flags |= osk->sk_flags & mask;
438 }
439 
440 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
441 			     (1UL << SOCK_KEEPOPEN) | \
442 			     (1UL << SOCK_LINGER) | \
443 			     (1UL << SOCK_BROADCAST) | \
444 			     (1UL << SOCK_TIMESTAMP) | \
445 			     (1UL << SOCK_DBG) | \
446 			     (1UL << SOCK_RCVTSTAMP) | \
447 			     (1UL << SOCK_RCVTSTAMPNS) | \
448 			     (1UL << SOCK_LOCALROUTE) | \
449 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
450 			     (1UL << SOCK_RXQ_OVFL) | \
451 			     (1UL << SOCK_WIFI_STATUS) | \
452 			     (1UL << SOCK_NOFCS) | \
453 			     (1UL << SOCK_FILTER_LOCKED) | \
454 			     (1UL << SOCK_TSTAMP_NEW))
455 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
456  * clc socket (since smc is not called for these options from net/core)
457  */
458 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
459 {
460 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
461 }
462 
463 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
464 			     (1UL << SOCK_KEEPOPEN) | \
465 			     (1UL << SOCK_LINGER) | \
466 			     (1UL << SOCK_DBG))
467 /* copy only settings and flags relevant for smc from clc to smc socket */
468 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
469 {
470 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
471 }
472 
473 /* register the new rmb on all links */
474 static int smcr_lgr_reg_rmbs(struct smc_link *link,
475 			     struct smc_buf_desc *rmb_desc)
476 {
477 	struct smc_link_group *lgr = link->lgr;
478 	int i, rc = 0;
479 
480 	rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
481 	if (rc)
482 		return rc;
483 	/* protect against parallel smc_llc_cli_rkey_exchange() and
484 	 * parallel smcr_link_reg_rmb()
485 	 */
486 	mutex_lock(&lgr->llc_conf_mutex);
487 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
488 		if (!smc_link_active(&lgr->lnk[i]))
489 			continue;
490 		rc = smcr_link_reg_rmb(&lgr->lnk[i], rmb_desc);
491 		if (rc)
492 			goto out;
493 	}
494 
495 	/* exchange confirm_rkey msg with peer */
496 	rc = smc_llc_do_confirm_rkey(link, rmb_desc);
497 	if (rc) {
498 		rc = -EFAULT;
499 		goto out;
500 	}
501 	rmb_desc->is_conf_rkey = true;
502 out:
503 	mutex_unlock(&lgr->llc_conf_mutex);
504 	smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
505 	return rc;
506 }
507 
508 static int smcr_clnt_conf_first_link(struct smc_sock *smc)
509 {
510 	struct smc_link *link = smc->conn.lnk;
511 	struct smc_llc_qentry *qentry;
512 	int rc;
513 
514 	/* receive CONFIRM LINK request from server over RoCE fabric */
515 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
516 			      SMC_LLC_CONFIRM_LINK);
517 	if (!qentry) {
518 		struct smc_clc_msg_decline dclc;
519 
520 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
521 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
522 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
523 	}
524 	smc_llc_save_peer_uid(qentry);
525 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_REQ);
526 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
527 	if (rc)
528 		return SMC_CLC_DECL_RMBE_EC;
529 
530 	rc = smc_ib_modify_qp_rts(link);
531 	if (rc)
532 		return SMC_CLC_DECL_ERR_RDYLNK;
533 
534 	smc_wr_remember_qp_attr(link);
535 
536 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc))
537 		return SMC_CLC_DECL_ERR_REGRMB;
538 
539 	/* confirm_rkey is implicit on 1st contact */
540 	smc->conn.rmb_desc->is_conf_rkey = true;
541 
542 	/* send CONFIRM LINK response over RoCE fabric */
543 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
544 	if (rc < 0)
545 		return SMC_CLC_DECL_TIMEOUT_CL;
546 
547 	smc_llc_link_active(link);
548 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
549 
550 	/* optional 2nd link, receive ADD LINK request from server */
551 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
552 			      SMC_LLC_ADD_LINK);
553 	if (!qentry) {
554 		struct smc_clc_msg_decline dclc;
555 
556 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
557 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
558 		if (rc == -EAGAIN)
559 			rc = 0; /* no DECLINE received, go with one link */
560 		return rc;
561 	}
562 	smc_llc_flow_qentry_clr(&link->lgr->llc_flow_lcl);
563 	smc_llc_cli_add_link(link, qentry);
564 	return 0;
565 }
566 
567 static bool smc_isascii(char *hostname)
568 {
569 	int i;
570 
571 	for (i = 0; i < SMC_MAX_HOSTNAME_LEN; i++)
572 		if (!isascii(hostname[i]))
573 			return false;
574 	return true;
575 }
576 
577 static void smc_conn_save_peer_info_fce(struct smc_sock *smc,
578 					struct smc_clc_msg_accept_confirm *clc)
579 {
580 	struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
581 		(struct smc_clc_msg_accept_confirm_v2 *)clc;
582 	struct smc_clc_first_contact_ext *fce;
583 	int clc_v2_len;
584 
585 	if (clc->hdr.version == SMC_V1 ||
586 	    !(clc->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
587 		return;
588 
589 	if (smc->conn.lgr->is_smcd) {
590 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->d1.eid,
591 		       SMC_MAX_EID_LEN);
592 		clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
593 					 d1);
594 	} else {
595 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->r1.eid,
596 		       SMC_MAX_EID_LEN);
597 		clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
598 					 r1);
599 	}
600 	fce = (struct smc_clc_first_contact_ext *)(((u8 *)clc_v2) + clc_v2_len);
601 	smc->conn.lgr->peer_os = fce->os_type;
602 	smc->conn.lgr->peer_smc_release = fce->release;
603 	if (smc_isascii(fce->hostname))
604 		memcpy(smc->conn.lgr->peer_hostname, fce->hostname,
605 		       SMC_MAX_HOSTNAME_LEN);
606 }
607 
608 static void smcr_conn_save_peer_info(struct smc_sock *smc,
609 				     struct smc_clc_msg_accept_confirm *clc)
610 {
611 	int bufsize = smc_uncompress_bufsize(clc->r0.rmbe_size);
612 
613 	smc->conn.peer_rmbe_idx = clc->r0.rmbe_idx;
614 	smc->conn.local_tx_ctrl.token = ntohl(clc->r0.rmbe_alert_token);
615 	smc->conn.peer_rmbe_size = bufsize;
616 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
617 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
618 }
619 
620 static void smcd_conn_save_peer_info(struct smc_sock *smc,
621 				     struct smc_clc_msg_accept_confirm *clc)
622 {
623 	int bufsize = smc_uncompress_bufsize(clc->d0.dmbe_size);
624 
625 	smc->conn.peer_rmbe_idx = clc->d0.dmbe_idx;
626 	smc->conn.peer_token = clc->d0.token;
627 	/* msg header takes up space in the buffer */
628 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
629 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
630 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
631 }
632 
633 static void smc_conn_save_peer_info(struct smc_sock *smc,
634 				    struct smc_clc_msg_accept_confirm *clc)
635 {
636 	if (smc->conn.lgr->is_smcd)
637 		smcd_conn_save_peer_info(smc, clc);
638 	else
639 		smcr_conn_save_peer_info(smc, clc);
640 	smc_conn_save_peer_info_fce(smc, clc);
641 }
642 
643 static void smc_link_save_peer_info(struct smc_link *link,
644 				    struct smc_clc_msg_accept_confirm *clc,
645 				    struct smc_init_info *ini)
646 {
647 	link->peer_qpn = ntoh24(clc->r0.qpn);
648 	memcpy(link->peer_gid, ini->peer_gid, SMC_GID_SIZE);
649 	memcpy(link->peer_mac, ini->peer_mac, sizeof(link->peer_mac));
650 	link->peer_psn = ntoh24(clc->r0.psn);
651 	link->peer_mtu = clc->r0.qp_mtu;
652 }
653 
654 static void smc_stat_inc_fback_rsn_cnt(struct smc_sock *smc,
655 				       struct smc_stats_fback *fback_arr)
656 {
657 	int cnt;
658 
659 	for (cnt = 0; cnt < SMC_MAX_FBACK_RSN_CNT; cnt++) {
660 		if (fback_arr[cnt].fback_code == smc->fallback_rsn) {
661 			fback_arr[cnt].count++;
662 			break;
663 		}
664 		if (!fback_arr[cnt].fback_code) {
665 			fback_arr[cnt].fback_code = smc->fallback_rsn;
666 			fback_arr[cnt].count++;
667 			break;
668 		}
669 	}
670 }
671 
672 static void smc_stat_fallback(struct smc_sock *smc)
673 {
674 	struct net *net = sock_net(&smc->sk);
675 
676 	mutex_lock(&net->smc.mutex_fback_rsn);
677 	if (smc->listen_smc) {
678 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->srv);
679 		net->smc.fback_rsn->srv_fback_cnt++;
680 	} else {
681 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->clnt);
682 		net->smc.fback_rsn->clnt_fback_cnt++;
683 	}
684 	mutex_unlock(&net->smc.mutex_fback_rsn);
685 }
686 
687 /* must be called under rcu read lock */
688 static void smc_fback_wakeup_waitqueue(struct smc_sock *smc, void *key)
689 {
690 	struct socket_wq *wq;
691 	__poll_t flags;
692 
693 	wq = rcu_dereference(smc->sk.sk_wq);
694 	if (!skwq_has_sleeper(wq))
695 		return;
696 
697 	/* wake up smc sk->sk_wq */
698 	if (!key) {
699 		/* sk_state_change */
700 		wake_up_interruptible_all(&wq->wait);
701 	} else {
702 		flags = key_to_poll(key);
703 		if (flags & (EPOLLIN | EPOLLOUT))
704 			/* sk_data_ready or sk_write_space */
705 			wake_up_interruptible_sync_poll(&wq->wait, flags);
706 		else if (flags & EPOLLERR)
707 			/* sk_error_report */
708 			wake_up_interruptible_poll(&wq->wait, flags);
709 	}
710 }
711 
712 static int smc_fback_mark_woken(wait_queue_entry_t *wait,
713 				unsigned int mode, int sync, void *key)
714 {
715 	struct smc_mark_woken *mark =
716 		container_of(wait, struct smc_mark_woken, wait_entry);
717 
718 	mark->woken = true;
719 	mark->key = key;
720 	return 0;
721 }
722 
723 static void smc_fback_forward_wakeup(struct smc_sock *smc, struct sock *clcsk,
724 				     void (*clcsock_callback)(struct sock *sk))
725 {
726 	struct smc_mark_woken mark = { .woken = false };
727 	struct socket_wq *wq;
728 
729 	init_waitqueue_func_entry(&mark.wait_entry,
730 				  smc_fback_mark_woken);
731 	rcu_read_lock();
732 	wq = rcu_dereference(clcsk->sk_wq);
733 	if (!wq)
734 		goto out;
735 	add_wait_queue(sk_sleep(clcsk), &mark.wait_entry);
736 	clcsock_callback(clcsk);
737 	remove_wait_queue(sk_sleep(clcsk), &mark.wait_entry);
738 
739 	if (mark.woken)
740 		smc_fback_wakeup_waitqueue(smc, mark.key);
741 out:
742 	rcu_read_unlock();
743 }
744 
745 static void smc_fback_state_change(struct sock *clcsk)
746 {
747 	struct smc_sock *smc =
748 		smc_clcsock_user_data(clcsk);
749 
750 	if (!smc)
751 		return;
752 	smc_fback_forward_wakeup(smc, clcsk, smc->clcsk_state_change);
753 }
754 
755 static void smc_fback_data_ready(struct sock *clcsk)
756 {
757 	struct smc_sock *smc =
758 		smc_clcsock_user_data(clcsk);
759 
760 	if (!smc)
761 		return;
762 	smc_fback_forward_wakeup(smc, clcsk, smc->clcsk_data_ready);
763 }
764 
765 static void smc_fback_write_space(struct sock *clcsk)
766 {
767 	struct smc_sock *smc =
768 		smc_clcsock_user_data(clcsk);
769 
770 	if (!smc)
771 		return;
772 	smc_fback_forward_wakeup(smc, clcsk, smc->clcsk_write_space);
773 }
774 
775 static void smc_fback_error_report(struct sock *clcsk)
776 {
777 	struct smc_sock *smc =
778 		smc_clcsock_user_data(clcsk);
779 
780 	if (!smc)
781 		return;
782 	smc_fback_forward_wakeup(smc, clcsk, smc->clcsk_error_report);
783 }
784 
785 static int smc_switch_to_fallback(struct smc_sock *smc, int reason_code)
786 {
787 	struct sock *clcsk;
788 	int rc = 0;
789 
790 	mutex_lock(&smc->clcsock_release_lock);
791 	if (!smc->clcsock) {
792 		rc = -EBADF;
793 		goto out;
794 	}
795 	clcsk = smc->clcsock->sk;
796 
797 	if (smc->use_fallback)
798 		goto out;
799 	smc->use_fallback = true;
800 	smc->fallback_rsn = reason_code;
801 	smc_stat_fallback(smc);
802 	trace_smc_switch_to_fallback(smc, reason_code);
803 	if (smc->sk.sk_socket && smc->sk.sk_socket->file) {
804 		smc->clcsock->file = smc->sk.sk_socket->file;
805 		smc->clcsock->file->private_data = smc->clcsock;
806 		smc->clcsock->wq.fasync_list =
807 			smc->sk.sk_socket->wq.fasync_list;
808 
809 		/* There might be some wait entries remaining
810 		 * in smc sk->sk_wq and they should be woken up
811 		 * as clcsock's wait queue is woken up.
812 		 */
813 		smc->clcsk_state_change = clcsk->sk_state_change;
814 		smc->clcsk_data_ready = clcsk->sk_data_ready;
815 		smc->clcsk_write_space = clcsk->sk_write_space;
816 		smc->clcsk_error_report = clcsk->sk_error_report;
817 
818 		clcsk->sk_state_change = smc_fback_state_change;
819 		clcsk->sk_data_ready = smc_fback_data_ready;
820 		clcsk->sk_write_space = smc_fback_write_space;
821 		clcsk->sk_error_report = smc_fback_error_report;
822 
823 		smc->clcsock->sk->sk_user_data =
824 			(void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
825 	}
826 out:
827 	mutex_unlock(&smc->clcsock_release_lock);
828 	return rc;
829 }
830 
831 /* fall back during connect */
832 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
833 {
834 	struct net *net = sock_net(&smc->sk);
835 	int rc = 0;
836 
837 	rc = smc_switch_to_fallback(smc, reason_code);
838 	if (rc) { /* fallback fails */
839 		this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
840 		if (smc->sk.sk_state == SMC_INIT)
841 			sock_put(&smc->sk); /* passive closing */
842 		return rc;
843 	}
844 	smc_copy_sock_settings_to_clc(smc);
845 	smc->connect_nonblock = 0;
846 	if (smc->sk.sk_state == SMC_INIT)
847 		smc->sk.sk_state = SMC_ACTIVE;
848 	return 0;
849 }
850 
851 /* decline and fall back during connect */
852 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code,
853 					u8 version)
854 {
855 	struct net *net = sock_net(&smc->sk);
856 	int rc;
857 
858 	if (reason_code < 0) { /* error, fallback is not possible */
859 		this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
860 		if (smc->sk.sk_state == SMC_INIT)
861 			sock_put(&smc->sk); /* passive closing */
862 		return reason_code;
863 	}
864 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
865 		rc = smc_clc_send_decline(smc, reason_code, version);
866 		if (rc < 0) {
867 			this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
868 			if (smc->sk.sk_state == SMC_INIT)
869 				sock_put(&smc->sk); /* passive closing */
870 			return rc;
871 		}
872 	}
873 	return smc_connect_fallback(smc, reason_code);
874 }
875 
876 static void smc_conn_abort(struct smc_sock *smc, int local_first)
877 {
878 	struct smc_connection *conn = &smc->conn;
879 	struct smc_link_group *lgr = conn->lgr;
880 	bool lgr_valid = false;
881 
882 	if (smc_conn_lgr_valid(conn))
883 		lgr_valid = true;
884 
885 	smc_conn_free(conn);
886 	if (local_first && lgr_valid)
887 		smc_lgr_cleanup_early(lgr);
888 }
889 
890 /* check if there is a rdma device available for this connection. */
891 /* called for connect and listen */
892 static int smc_find_rdma_device(struct smc_sock *smc, struct smc_init_info *ini)
893 {
894 	/* PNET table look up: search active ib_device and port
895 	 * within same PNETID that also contains the ethernet device
896 	 * used for the internal TCP socket
897 	 */
898 	smc_pnet_find_roce_resource(smc->clcsock->sk, ini);
899 	if (!ini->check_smcrv2 && !ini->ib_dev)
900 		return SMC_CLC_DECL_NOSMCRDEV;
901 	if (ini->check_smcrv2 && !ini->smcrv2.ib_dev_v2)
902 		return SMC_CLC_DECL_NOSMCRDEV;
903 	return 0;
904 }
905 
906 /* check if there is an ISM device available for this connection. */
907 /* called for connect and listen */
908 static int smc_find_ism_device(struct smc_sock *smc, struct smc_init_info *ini)
909 {
910 	/* Find ISM device with same PNETID as connecting interface  */
911 	smc_pnet_find_ism_resource(smc->clcsock->sk, ini);
912 	if (!ini->ism_dev[0])
913 		return SMC_CLC_DECL_NOSMCDDEV;
914 	else
915 		ini->ism_chid[0] = smc_ism_get_chid(ini->ism_dev[0]);
916 	return 0;
917 }
918 
919 /* is chid unique for the ism devices that are already determined? */
920 static bool smc_find_ism_v2_is_unique_chid(u16 chid, struct smc_init_info *ini,
921 					   int cnt)
922 {
923 	int i = (!ini->ism_dev[0]) ? 1 : 0;
924 
925 	for (; i < cnt; i++)
926 		if (ini->ism_chid[i] == chid)
927 			return false;
928 	return true;
929 }
930 
931 /* determine possible V2 ISM devices (either without PNETID or with PNETID plus
932  * PNETID matching net_device)
933  */
934 static int smc_find_ism_v2_device_clnt(struct smc_sock *smc,
935 				       struct smc_init_info *ini)
936 {
937 	int rc = SMC_CLC_DECL_NOSMCDDEV;
938 	struct smcd_dev *smcd;
939 	int i = 1;
940 	u16 chid;
941 
942 	if (smcd_indicated(ini->smc_type_v1))
943 		rc = 0;		/* already initialized for V1 */
944 	mutex_lock(&smcd_dev_list.mutex);
945 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
946 		if (smcd->going_away || smcd == ini->ism_dev[0])
947 			continue;
948 		chid = smc_ism_get_chid(smcd);
949 		if (!smc_find_ism_v2_is_unique_chid(chid, ini, i))
950 			continue;
951 		if (!smc_pnet_is_pnetid_set(smcd->pnetid) ||
952 		    smc_pnet_is_ndev_pnetid(sock_net(&smc->sk), smcd->pnetid)) {
953 			ini->ism_dev[i] = smcd;
954 			ini->ism_chid[i] = chid;
955 			ini->is_smcd = true;
956 			rc = 0;
957 			i++;
958 			if (i > SMC_MAX_ISM_DEVS)
959 				break;
960 		}
961 	}
962 	mutex_unlock(&smcd_dev_list.mutex);
963 	ini->ism_offered_cnt = i - 1;
964 	if (!ini->ism_dev[0] && !ini->ism_dev[1])
965 		ini->smcd_version = 0;
966 
967 	return rc;
968 }
969 
970 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
971 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
972 				      struct smc_init_info *ini)
973 {
974 	if (ini->vlan_id && smc_ism_get_vlan(ini->ism_dev[0], ini->vlan_id))
975 		return SMC_CLC_DECL_ISMVLANERR;
976 	return 0;
977 }
978 
979 static int smc_find_proposal_devices(struct smc_sock *smc,
980 				     struct smc_init_info *ini)
981 {
982 	int rc = 0;
983 
984 	/* check if there is an ism device available */
985 	if (!(ini->smcd_version & SMC_V1) ||
986 	    smc_find_ism_device(smc, ini) ||
987 	    smc_connect_ism_vlan_setup(smc, ini))
988 		ini->smcd_version &= ~SMC_V1;
989 	/* else ISM V1 is supported for this connection */
990 
991 	/* check if there is an rdma device available */
992 	if (!(ini->smcr_version & SMC_V1) ||
993 	    smc_find_rdma_device(smc, ini))
994 		ini->smcr_version &= ~SMC_V1;
995 	/* else RDMA is supported for this connection */
996 
997 	ini->smc_type_v1 = smc_indicated_type(ini->smcd_version & SMC_V1,
998 					      ini->smcr_version & SMC_V1);
999 
1000 	/* check if there is an ism v2 device available */
1001 	if (!(ini->smcd_version & SMC_V2) ||
1002 	    !smc_ism_is_v2_capable() ||
1003 	    smc_find_ism_v2_device_clnt(smc, ini))
1004 		ini->smcd_version &= ~SMC_V2;
1005 
1006 	/* check if there is an rdma v2 device available */
1007 	ini->check_smcrv2 = true;
1008 	ini->smcrv2.saddr = smc->clcsock->sk->sk_rcv_saddr;
1009 	if (!(ini->smcr_version & SMC_V2) ||
1010 	    smc->clcsock->sk->sk_family != AF_INET ||
1011 	    !smc_clc_ueid_count() ||
1012 	    smc_find_rdma_device(smc, ini))
1013 		ini->smcr_version &= ~SMC_V2;
1014 	ini->check_smcrv2 = false;
1015 
1016 	ini->smc_type_v2 = smc_indicated_type(ini->smcd_version & SMC_V2,
1017 					      ini->smcr_version & SMC_V2);
1018 
1019 	/* if neither ISM nor RDMA are supported, fallback */
1020 	if (ini->smc_type_v1 == SMC_TYPE_N && ini->smc_type_v2 == SMC_TYPE_N)
1021 		rc = SMC_CLC_DECL_NOSMCDEV;
1022 
1023 	return rc;
1024 }
1025 
1026 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
1027  * used, the VLAN ID will be registered again during the connection setup.
1028  */
1029 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc,
1030 					struct smc_init_info *ini)
1031 {
1032 	if (!smcd_indicated(ini->smc_type_v1))
1033 		return 0;
1034 	if (ini->vlan_id && smc_ism_put_vlan(ini->ism_dev[0], ini->vlan_id))
1035 		return SMC_CLC_DECL_CNFERR;
1036 	return 0;
1037 }
1038 
1039 #define SMC_CLC_MAX_ACCEPT_LEN \
1040 	(sizeof(struct smc_clc_msg_accept_confirm_v2) + \
1041 	 sizeof(struct smc_clc_first_contact_ext) + \
1042 	 sizeof(struct smc_clc_msg_trail))
1043 
1044 /* CLC handshake during connect */
1045 static int smc_connect_clc(struct smc_sock *smc,
1046 			   struct smc_clc_msg_accept_confirm_v2 *aclc2,
1047 			   struct smc_init_info *ini)
1048 {
1049 	int rc = 0;
1050 
1051 	/* do inband token exchange */
1052 	rc = smc_clc_send_proposal(smc, ini);
1053 	if (rc)
1054 		return rc;
1055 	/* receive SMC Accept CLC message */
1056 	return smc_clc_wait_msg(smc, aclc2, SMC_CLC_MAX_ACCEPT_LEN,
1057 				SMC_CLC_ACCEPT, CLC_WAIT_TIME);
1058 }
1059 
1060 void smc_fill_gid_list(struct smc_link_group *lgr,
1061 		       struct smc_gidlist *gidlist,
1062 		       struct smc_ib_device *known_dev, u8 *known_gid)
1063 {
1064 	struct smc_init_info *alt_ini = NULL;
1065 
1066 	memset(gidlist, 0, sizeof(*gidlist));
1067 	memcpy(gidlist->list[gidlist->len++], known_gid, SMC_GID_SIZE);
1068 
1069 	alt_ini = kzalloc(sizeof(*alt_ini), GFP_KERNEL);
1070 	if (!alt_ini)
1071 		goto out;
1072 
1073 	alt_ini->vlan_id = lgr->vlan_id;
1074 	alt_ini->check_smcrv2 = true;
1075 	alt_ini->smcrv2.saddr = lgr->saddr;
1076 	smc_pnet_find_alt_roce(lgr, alt_ini, known_dev);
1077 
1078 	if (!alt_ini->smcrv2.ib_dev_v2)
1079 		goto out;
1080 
1081 	memcpy(gidlist->list[gidlist->len++], alt_ini->smcrv2.ib_gid_v2,
1082 	       SMC_GID_SIZE);
1083 
1084 out:
1085 	kfree(alt_ini);
1086 }
1087 
1088 static int smc_connect_rdma_v2_prepare(struct smc_sock *smc,
1089 				       struct smc_clc_msg_accept_confirm *aclc,
1090 				       struct smc_init_info *ini)
1091 {
1092 	struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
1093 		(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1094 	struct smc_clc_first_contact_ext *fce =
1095 		(struct smc_clc_first_contact_ext *)
1096 			(((u8 *)clc_v2) + sizeof(*clc_v2));
1097 
1098 	if (!ini->first_contact_peer || aclc->hdr.version == SMC_V1)
1099 		return 0;
1100 
1101 	if (fce->v2_direct) {
1102 		memcpy(ini->smcrv2.nexthop_mac, &aclc->r0.lcl.mac, ETH_ALEN);
1103 		ini->smcrv2.uses_gateway = false;
1104 	} else {
1105 		if (smc_ib_find_route(smc->clcsock->sk->sk_rcv_saddr,
1106 				      smc_ib_gid_to_ipv4(aclc->r0.lcl.gid),
1107 				      ini->smcrv2.nexthop_mac,
1108 				      &ini->smcrv2.uses_gateway))
1109 			return SMC_CLC_DECL_NOROUTE;
1110 		if (!ini->smcrv2.uses_gateway) {
1111 			/* mismatch: peer claims indirect, but its direct */
1112 			return SMC_CLC_DECL_NOINDIRECT;
1113 		}
1114 	}
1115 	return 0;
1116 }
1117 
1118 /* setup for RDMA connection of client */
1119 static int smc_connect_rdma(struct smc_sock *smc,
1120 			    struct smc_clc_msg_accept_confirm *aclc,
1121 			    struct smc_init_info *ini)
1122 {
1123 	int i, reason_code = 0;
1124 	struct smc_link *link;
1125 	u8 *eid = NULL;
1126 
1127 	ini->is_smcd = false;
1128 	ini->ib_clcqpn = ntoh24(aclc->r0.qpn);
1129 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
1130 	memcpy(ini->peer_systemid, aclc->r0.lcl.id_for_peer, SMC_SYSTEMID_LEN);
1131 	memcpy(ini->peer_gid, aclc->r0.lcl.gid, SMC_GID_SIZE);
1132 	memcpy(ini->peer_mac, aclc->r0.lcl.mac, ETH_ALEN);
1133 
1134 	reason_code = smc_connect_rdma_v2_prepare(smc, aclc, ini);
1135 	if (reason_code)
1136 		return reason_code;
1137 
1138 	mutex_lock(&smc_client_lgr_pending);
1139 	reason_code = smc_conn_create(smc, ini);
1140 	if (reason_code) {
1141 		mutex_unlock(&smc_client_lgr_pending);
1142 		return reason_code;
1143 	}
1144 
1145 	smc_conn_save_peer_info(smc, aclc);
1146 
1147 	if (ini->first_contact_local) {
1148 		link = smc->conn.lnk;
1149 	} else {
1150 		/* set link that was assigned by server */
1151 		link = NULL;
1152 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1153 			struct smc_link *l = &smc->conn.lgr->lnk[i];
1154 
1155 			if (l->peer_qpn == ntoh24(aclc->r0.qpn) &&
1156 			    !memcmp(l->peer_gid, &aclc->r0.lcl.gid,
1157 				    SMC_GID_SIZE) &&
1158 			    (aclc->hdr.version > SMC_V1 ||
1159 			     !memcmp(l->peer_mac, &aclc->r0.lcl.mac,
1160 				     sizeof(l->peer_mac)))) {
1161 				link = l;
1162 				break;
1163 			}
1164 		}
1165 		if (!link) {
1166 			reason_code = SMC_CLC_DECL_NOSRVLINK;
1167 			goto connect_abort;
1168 		}
1169 		smc_switch_link_and_count(&smc->conn, link);
1170 	}
1171 
1172 	/* create send buffer and rmb */
1173 	if (smc_buf_create(smc, false)) {
1174 		reason_code = SMC_CLC_DECL_MEM;
1175 		goto connect_abort;
1176 	}
1177 
1178 	if (ini->first_contact_local)
1179 		smc_link_save_peer_info(link, aclc, ini);
1180 
1181 	if (smc_rmb_rtoken_handling(&smc->conn, link, aclc)) {
1182 		reason_code = SMC_CLC_DECL_ERR_RTOK;
1183 		goto connect_abort;
1184 	}
1185 
1186 	smc_close_init(smc);
1187 	smc_rx_init(smc);
1188 
1189 	if (ini->first_contact_local) {
1190 		if (smc_ib_ready_link(link)) {
1191 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
1192 			goto connect_abort;
1193 		}
1194 	} else {
1195 		if (smcr_lgr_reg_rmbs(link, smc->conn.rmb_desc)) {
1196 			reason_code = SMC_CLC_DECL_ERR_REGRMB;
1197 			goto connect_abort;
1198 		}
1199 	}
1200 	smc_rmb_sync_sg_for_device(&smc->conn);
1201 
1202 	if (aclc->hdr.version > SMC_V1) {
1203 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
1204 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1205 
1206 		eid = clc_v2->r1.eid;
1207 		if (ini->first_contact_local)
1208 			smc_fill_gid_list(link->lgr, &ini->smcrv2.gidlist,
1209 					  link->smcibdev, link->gid);
1210 	}
1211 
1212 	reason_code = smc_clc_send_confirm(smc, ini->first_contact_local,
1213 					   aclc->hdr.version, eid, ini);
1214 	if (reason_code)
1215 		goto connect_abort;
1216 
1217 	smc_tx_init(smc);
1218 
1219 	if (ini->first_contact_local) {
1220 		/* QP confirmation over RoCE fabric */
1221 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
1222 		reason_code = smcr_clnt_conf_first_link(smc);
1223 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
1224 		if (reason_code)
1225 			goto connect_abort;
1226 	}
1227 	mutex_unlock(&smc_client_lgr_pending);
1228 
1229 	smc_copy_sock_settings_to_clc(smc);
1230 	smc->connect_nonblock = 0;
1231 	if (smc->sk.sk_state == SMC_INIT)
1232 		smc->sk.sk_state = SMC_ACTIVE;
1233 
1234 	return 0;
1235 connect_abort:
1236 	smc_conn_abort(smc, ini->first_contact_local);
1237 	mutex_unlock(&smc_client_lgr_pending);
1238 	smc->connect_nonblock = 0;
1239 
1240 	return reason_code;
1241 }
1242 
1243 /* The server has chosen one of the proposed ISM devices for the communication.
1244  * Determine from the CHID of the received CLC ACCEPT the ISM device chosen.
1245  */
1246 static int
1247 smc_v2_determine_accepted_chid(struct smc_clc_msg_accept_confirm_v2 *aclc,
1248 			       struct smc_init_info *ini)
1249 {
1250 	int i;
1251 
1252 	for (i = 0; i < ini->ism_offered_cnt + 1; i++) {
1253 		if (ini->ism_chid[i] == ntohs(aclc->d1.chid)) {
1254 			ini->ism_selected = i;
1255 			return 0;
1256 		}
1257 	}
1258 
1259 	return -EPROTO;
1260 }
1261 
1262 /* setup for ISM connection of client */
1263 static int smc_connect_ism(struct smc_sock *smc,
1264 			   struct smc_clc_msg_accept_confirm *aclc,
1265 			   struct smc_init_info *ini)
1266 {
1267 	u8 *eid = NULL;
1268 	int rc = 0;
1269 
1270 	ini->is_smcd = true;
1271 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
1272 
1273 	if (aclc->hdr.version == SMC_V2) {
1274 		struct smc_clc_msg_accept_confirm_v2 *aclc_v2 =
1275 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1276 
1277 		rc = smc_v2_determine_accepted_chid(aclc_v2, ini);
1278 		if (rc)
1279 			return rc;
1280 	}
1281 	ini->ism_peer_gid[ini->ism_selected] = aclc->d0.gid;
1282 
1283 	/* there is only one lgr role for SMC-D; use server lock */
1284 	mutex_lock(&smc_server_lgr_pending);
1285 	rc = smc_conn_create(smc, ini);
1286 	if (rc) {
1287 		mutex_unlock(&smc_server_lgr_pending);
1288 		return rc;
1289 	}
1290 
1291 	/* Create send and receive buffers */
1292 	rc = smc_buf_create(smc, true);
1293 	if (rc) {
1294 		rc = (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB : SMC_CLC_DECL_MEM;
1295 		goto connect_abort;
1296 	}
1297 
1298 	smc_conn_save_peer_info(smc, aclc);
1299 	smc_close_init(smc);
1300 	smc_rx_init(smc);
1301 	smc_tx_init(smc);
1302 
1303 	if (aclc->hdr.version > SMC_V1) {
1304 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
1305 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1306 
1307 		eid = clc_v2->d1.eid;
1308 	}
1309 
1310 	rc = smc_clc_send_confirm(smc, ini->first_contact_local,
1311 				  aclc->hdr.version, eid, NULL);
1312 	if (rc)
1313 		goto connect_abort;
1314 	mutex_unlock(&smc_server_lgr_pending);
1315 
1316 	smc_copy_sock_settings_to_clc(smc);
1317 	smc->connect_nonblock = 0;
1318 	if (smc->sk.sk_state == SMC_INIT)
1319 		smc->sk.sk_state = SMC_ACTIVE;
1320 
1321 	return 0;
1322 connect_abort:
1323 	smc_conn_abort(smc, ini->first_contact_local);
1324 	mutex_unlock(&smc_server_lgr_pending);
1325 	smc->connect_nonblock = 0;
1326 
1327 	return rc;
1328 }
1329 
1330 /* check if received accept type and version matches a proposed one */
1331 static int smc_connect_check_aclc(struct smc_init_info *ini,
1332 				  struct smc_clc_msg_accept_confirm *aclc)
1333 {
1334 	if (aclc->hdr.typev1 != SMC_TYPE_R &&
1335 	    aclc->hdr.typev1 != SMC_TYPE_D)
1336 		return SMC_CLC_DECL_MODEUNSUPP;
1337 
1338 	if (aclc->hdr.version >= SMC_V2) {
1339 		if ((aclc->hdr.typev1 == SMC_TYPE_R &&
1340 		     !smcr_indicated(ini->smc_type_v2)) ||
1341 		    (aclc->hdr.typev1 == SMC_TYPE_D &&
1342 		     !smcd_indicated(ini->smc_type_v2)))
1343 			return SMC_CLC_DECL_MODEUNSUPP;
1344 	} else {
1345 		if ((aclc->hdr.typev1 == SMC_TYPE_R &&
1346 		     !smcr_indicated(ini->smc_type_v1)) ||
1347 		    (aclc->hdr.typev1 == SMC_TYPE_D &&
1348 		     !smcd_indicated(ini->smc_type_v1)))
1349 			return SMC_CLC_DECL_MODEUNSUPP;
1350 	}
1351 
1352 	return 0;
1353 }
1354 
1355 /* perform steps before actually connecting */
1356 static int __smc_connect(struct smc_sock *smc)
1357 {
1358 	u8 version = smc_ism_is_v2_capable() ? SMC_V2 : SMC_V1;
1359 	struct smc_clc_msg_accept_confirm_v2 *aclc2;
1360 	struct smc_clc_msg_accept_confirm *aclc;
1361 	struct smc_init_info *ini = NULL;
1362 	u8 *buf = NULL;
1363 	int rc = 0;
1364 
1365 	if (smc->use_fallback)
1366 		return smc_connect_fallback(smc, smc->fallback_rsn);
1367 
1368 	/* if peer has not signalled SMC-capability, fall back */
1369 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
1370 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
1371 
1372 	/* IPSec connections opt out of SMC optimizations */
1373 	if (using_ipsec(smc))
1374 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC,
1375 						    version);
1376 
1377 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1378 	if (!ini)
1379 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_MEM,
1380 						    version);
1381 
1382 	ini->smcd_version = SMC_V1 | SMC_V2;
1383 	ini->smcr_version = SMC_V1 | SMC_V2;
1384 	ini->smc_type_v1 = SMC_TYPE_B;
1385 	ini->smc_type_v2 = SMC_TYPE_B;
1386 
1387 	/* get vlan id from IP device */
1388 	if (smc_vlan_by_tcpsk(smc->clcsock, ini)) {
1389 		ini->smcd_version &= ~SMC_V1;
1390 		ini->smcr_version = 0;
1391 		ini->smc_type_v1 = SMC_TYPE_N;
1392 		if (!ini->smcd_version) {
1393 			rc = SMC_CLC_DECL_GETVLANERR;
1394 			goto fallback;
1395 		}
1396 	}
1397 
1398 	rc = smc_find_proposal_devices(smc, ini);
1399 	if (rc)
1400 		goto fallback;
1401 
1402 	buf = kzalloc(SMC_CLC_MAX_ACCEPT_LEN, GFP_KERNEL);
1403 	if (!buf) {
1404 		rc = SMC_CLC_DECL_MEM;
1405 		goto fallback;
1406 	}
1407 	aclc2 = (struct smc_clc_msg_accept_confirm_v2 *)buf;
1408 	aclc = (struct smc_clc_msg_accept_confirm *)aclc2;
1409 
1410 	/* perform CLC handshake */
1411 	rc = smc_connect_clc(smc, aclc2, ini);
1412 	if (rc) {
1413 		/* -EAGAIN on timeout, see tcp_recvmsg() */
1414 		if (rc == -EAGAIN) {
1415 			rc = -ETIMEDOUT;
1416 			smc->sk.sk_err = ETIMEDOUT;
1417 		}
1418 		goto vlan_cleanup;
1419 	}
1420 
1421 	/* check if smc modes and versions of CLC proposal and accept match */
1422 	rc = smc_connect_check_aclc(ini, aclc);
1423 	version = aclc->hdr.version == SMC_V1 ? SMC_V1 : SMC_V2;
1424 	if (rc)
1425 		goto vlan_cleanup;
1426 
1427 	/* depending on previous steps, connect using rdma or ism */
1428 	if (aclc->hdr.typev1 == SMC_TYPE_R) {
1429 		ini->smcr_version = version;
1430 		rc = smc_connect_rdma(smc, aclc, ini);
1431 	} else if (aclc->hdr.typev1 == SMC_TYPE_D) {
1432 		ini->smcd_version = version;
1433 		rc = smc_connect_ism(smc, aclc, ini);
1434 	}
1435 	if (rc)
1436 		goto vlan_cleanup;
1437 
1438 	SMC_STAT_CLNT_SUCC_INC(sock_net(smc->clcsock->sk), aclc);
1439 	smc_connect_ism_vlan_cleanup(smc, ini);
1440 	kfree(buf);
1441 	kfree(ini);
1442 	return 0;
1443 
1444 vlan_cleanup:
1445 	smc_connect_ism_vlan_cleanup(smc, ini);
1446 	kfree(buf);
1447 fallback:
1448 	kfree(ini);
1449 	return smc_connect_decline_fallback(smc, rc, version);
1450 }
1451 
1452 static void smc_connect_work(struct work_struct *work)
1453 {
1454 	struct smc_sock *smc = container_of(work, struct smc_sock,
1455 					    connect_work);
1456 	long timeo = smc->sk.sk_sndtimeo;
1457 	int rc = 0;
1458 
1459 	if (!timeo)
1460 		timeo = MAX_SCHEDULE_TIMEOUT;
1461 	lock_sock(smc->clcsock->sk);
1462 	if (smc->clcsock->sk->sk_err) {
1463 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
1464 	} else if ((1 << smc->clcsock->sk->sk_state) &
1465 					(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
1466 		rc = sk_stream_wait_connect(smc->clcsock->sk, &timeo);
1467 		if ((rc == -EPIPE) &&
1468 		    ((1 << smc->clcsock->sk->sk_state) &
1469 					(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))
1470 			rc = 0;
1471 	}
1472 	release_sock(smc->clcsock->sk);
1473 	lock_sock(&smc->sk);
1474 	if (rc != 0 || smc->sk.sk_err) {
1475 		smc->sk.sk_state = SMC_CLOSED;
1476 		if (rc == -EPIPE || rc == -EAGAIN)
1477 			smc->sk.sk_err = EPIPE;
1478 		else if (signal_pending(current))
1479 			smc->sk.sk_err = -sock_intr_errno(timeo);
1480 		sock_put(&smc->sk); /* passive closing */
1481 		goto out;
1482 	}
1483 
1484 	rc = __smc_connect(smc);
1485 	if (rc < 0)
1486 		smc->sk.sk_err = -rc;
1487 
1488 out:
1489 	if (!sock_flag(&smc->sk, SOCK_DEAD)) {
1490 		if (smc->sk.sk_err) {
1491 			smc->sk.sk_state_change(&smc->sk);
1492 		} else { /* allow polling before and after fallback decision */
1493 			smc->clcsock->sk->sk_write_space(smc->clcsock->sk);
1494 			smc->sk.sk_write_space(&smc->sk);
1495 		}
1496 	}
1497 	release_sock(&smc->sk);
1498 }
1499 
1500 static int smc_connect(struct socket *sock, struct sockaddr *addr,
1501 		       int alen, int flags)
1502 {
1503 	struct sock *sk = sock->sk;
1504 	struct smc_sock *smc;
1505 	int rc = -EINVAL;
1506 
1507 	smc = smc_sk(sk);
1508 
1509 	/* separate smc parameter checking to be safe */
1510 	if (alen < sizeof(addr->sa_family))
1511 		goto out_err;
1512 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
1513 		goto out_err;
1514 
1515 	lock_sock(sk);
1516 	switch (sk->sk_state) {
1517 	default:
1518 		goto out;
1519 	case SMC_ACTIVE:
1520 		rc = -EISCONN;
1521 		goto out;
1522 	case SMC_INIT:
1523 		break;
1524 	}
1525 
1526 	smc_copy_sock_settings_to_clc(smc);
1527 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1528 	if (smc->connect_nonblock) {
1529 		rc = -EALREADY;
1530 		goto out;
1531 	}
1532 	rc = kernel_connect(smc->clcsock, addr, alen, flags);
1533 	if (rc && rc != -EINPROGRESS)
1534 		goto out;
1535 
1536 	sock_hold(&smc->sk); /* sock put in passive closing */
1537 	if (smc->use_fallback)
1538 		goto out;
1539 	if (flags & O_NONBLOCK) {
1540 		if (queue_work(smc_hs_wq, &smc->connect_work))
1541 			smc->connect_nonblock = 1;
1542 		rc = -EINPROGRESS;
1543 	} else {
1544 		rc = __smc_connect(smc);
1545 		if (rc < 0)
1546 			goto out;
1547 		else
1548 			rc = 0; /* success cases including fallback */
1549 	}
1550 
1551 out:
1552 	release_sock(sk);
1553 out_err:
1554 	return rc;
1555 }
1556 
1557 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
1558 {
1559 	struct socket *new_clcsock = NULL;
1560 	struct sock *lsk = &lsmc->sk;
1561 	struct sock *new_sk;
1562 	int rc = -EINVAL;
1563 
1564 	release_sock(lsk);
1565 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
1566 	if (!new_sk) {
1567 		rc = -ENOMEM;
1568 		lsk->sk_err = ENOMEM;
1569 		*new_smc = NULL;
1570 		lock_sock(lsk);
1571 		goto out;
1572 	}
1573 	*new_smc = smc_sk(new_sk);
1574 
1575 	mutex_lock(&lsmc->clcsock_release_lock);
1576 	if (lsmc->clcsock)
1577 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, SOCK_NONBLOCK);
1578 	mutex_unlock(&lsmc->clcsock_release_lock);
1579 	lock_sock(lsk);
1580 	if  (rc < 0 && rc != -EAGAIN)
1581 		lsk->sk_err = -rc;
1582 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
1583 		new_sk->sk_prot->unhash(new_sk);
1584 		if (new_clcsock)
1585 			sock_release(new_clcsock);
1586 		new_sk->sk_state = SMC_CLOSED;
1587 		sock_set_flag(new_sk, SOCK_DEAD);
1588 		sock_put(new_sk); /* final */
1589 		*new_smc = NULL;
1590 		goto out;
1591 	}
1592 
1593 	/* new clcsock has inherited the smc listen-specific sk_data_ready
1594 	 * function; switch it back to the original sk_data_ready function
1595 	 */
1596 	new_clcsock->sk->sk_data_ready = lsmc->clcsk_data_ready;
1597 	(*new_smc)->clcsock = new_clcsock;
1598 out:
1599 	return rc;
1600 }
1601 
1602 /* add a just created sock to the accept queue of the listen sock as
1603  * candidate for a following socket accept call from user space
1604  */
1605 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
1606 {
1607 	struct smc_sock *par = smc_sk(parent);
1608 
1609 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
1610 	spin_lock(&par->accept_q_lock);
1611 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
1612 	spin_unlock(&par->accept_q_lock);
1613 	sk_acceptq_added(parent);
1614 }
1615 
1616 /* remove a socket from the accept queue of its parental listening socket */
1617 static void smc_accept_unlink(struct sock *sk)
1618 {
1619 	struct smc_sock *par = smc_sk(sk)->listen_smc;
1620 
1621 	spin_lock(&par->accept_q_lock);
1622 	list_del_init(&smc_sk(sk)->accept_q);
1623 	spin_unlock(&par->accept_q_lock);
1624 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
1625 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
1626 }
1627 
1628 /* remove a sock from the accept queue to bind it to a new socket created
1629  * for a socket accept call from user space
1630  */
1631 struct sock *smc_accept_dequeue(struct sock *parent,
1632 				struct socket *new_sock)
1633 {
1634 	struct smc_sock *isk, *n;
1635 	struct sock *new_sk;
1636 
1637 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
1638 		new_sk = (struct sock *)isk;
1639 
1640 		smc_accept_unlink(new_sk);
1641 		if (new_sk->sk_state == SMC_CLOSED) {
1642 			new_sk->sk_prot->unhash(new_sk);
1643 			if (isk->clcsock) {
1644 				sock_release(isk->clcsock);
1645 				isk->clcsock = NULL;
1646 			}
1647 			sock_put(new_sk); /* final */
1648 			continue;
1649 		}
1650 		if (new_sock) {
1651 			sock_graft(new_sk, new_sock);
1652 			if (isk->use_fallback) {
1653 				smc_sk(new_sk)->clcsock->file = new_sock->file;
1654 				isk->clcsock->file->private_data = isk->clcsock;
1655 			}
1656 		}
1657 		return new_sk;
1658 	}
1659 	return NULL;
1660 }
1661 
1662 /* clean up for a created but never accepted sock */
1663 void smc_close_non_accepted(struct sock *sk)
1664 {
1665 	struct smc_sock *smc = smc_sk(sk);
1666 
1667 	sock_hold(sk); /* sock_put below */
1668 	lock_sock(sk);
1669 	if (!sk->sk_lingertime)
1670 		/* wait for peer closing */
1671 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
1672 	__smc_release(smc);
1673 	release_sock(sk);
1674 	sock_put(sk); /* sock_hold above */
1675 	sock_put(sk); /* final sock_put */
1676 }
1677 
1678 static int smcr_serv_conf_first_link(struct smc_sock *smc)
1679 {
1680 	struct smc_link *link = smc->conn.lnk;
1681 	struct smc_llc_qentry *qentry;
1682 	int rc;
1683 
1684 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc))
1685 		return SMC_CLC_DECL_ERR_REGRMB;
1686 
1687 	/* send CONFIRM LINK request to client over the RoCE fabric */
1688 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
1689 	if (rc < 0)
1690 		return SMC_CLC_DECL_TIMEOUT_CL;
1691 
1692 	/* receive CONFIRM LINK response from client over the RoCE fabric */
1693 	qentry = smc_llc_wait(link->lgr, link, SMC_LLC_WAIT_TIME,
1694 			      SMC_LLC_CONFIRM_LINK);
1695 	if (!qentry) {
1696 		struct smc_clc_msg_decline dclc;
1697 
1698 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1699 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1700 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
1701 	}
1702 	smc_llc_save_peer_uid(qentry);
1703 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_RESP);
1704 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
1705 	if (rc)
1706 		return SMC_CLC_DECL_RMBE_EC;
1707 
1708 	/* confirm_rkey is implicit on 1st contact */
1709 	smc->conn.rmb_desc->is_conf_rkey = true;
1710 
1711 	smc_llc_link_active(link);
1712 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
1713 
1714 	/* initial contact - try to establish second link */
1715 	smc_llc_srv_add_link(link, NULL);
1716 	return 0;
1717 }
1718 
1719 /* listen worker: finish */
1720 static void smc_listen_out(struct smc_sock *new_smc)
1721 {
1722 	struct smc_sock *lsmc = new_smc->listen_smc;
1723 	struct sock *newsmcsk = &new_smc->sk;
1724 
1725 	if (tcp_sk(new_smc->clcsock->sk)->syn_smc)
1726 		atomic_dec(&lsmc->queued_smc_hs);
1727 
1728 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1729 		lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1730 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1731 		release_sock(&lsmc->sk);
1732 	} else { /* no longer listening */
1733 		smc_close_non_accepted(newsmcsk);
1734 	}
1735 
1736 	/* Wake up accept */
1737 	lsmc->sk.sk_data_ready(&lsmc->sk);
1738 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1739 }
1740 
1741 /* listen worker: finish in state connected */
1742 static void smc_listen_out_connected(struct smc_sock *new_smc)
1743 {
1744 	struct sock *newsmcsk = &new_smc->sk;
1745 
1746 	sk_refcnt_debug_inc(newsmcsk);
1747 	if (newsmcsk->sk_state == SMC_INIT)
1748 		newsmcsk->sk_state = SMC_ACTIVE;
1749 
1750 	smc_listen_out(new_smc);
1751 }
1752 
1753 /* listen worker: finish in error state */
1754 static void smc_listen_out_err(struct smc_sock *new_smc)
1755 {
1756 	struct sock *newsmcsk = &new_smc->sk;
1757 	struct net *net = sock_net(newsmcsk);
1758 
1759 	this_cpu_inc(net->smc.smc_stats->srv_hshake_err_cnt);
1760 	if (newsmcsk->sk_state == SMC_INIT)
1761 		sock_put(&new_smc->sk); /* passive closing */
1762 	newsmcsk->sk_state = SMC_CLOSED;
1763 
1764 	smc_listen_out(new_smc);
1765 }
1766 
1767 /* listen worker: decline and fall back if possible */
1768 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1769 			       int local_first, u8 version)
1770 {
1771 	/* RDMA setup failed, switch back to TCP */
1772 	smc_conn_abort(new_smc, local_first);
1773 	if (reason_code < 0 ||
1774 	    smc_switch_to_fallback(new_smc, reason_code)) {
1775 		/* error, no fallback possible */
1776 		smc_listen_out_err(new_smc);
1777 		return;
1778 	}
1779 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1780 		if (smc_clc_send_decline(new_smc, reason_code, version) < 0) {
1781 			smc_listen_out_err(new_smc);
1782 			return;
1783 		}
1784 	}
1785 	smc_listen_out_connected(new_smc);
1786 }
1787 
1788 /* listen worker: version checking */
1789 static int smc_listen_v2_check(struct smc_sock *new_smc,
1790 			       struct smc_clc_msg_proposal *pclc,
1791 			       struct smc_init_info *ini)
1792 {
1793 	struct smc_clc_smcd_v2_extension *pclc_smcd_v2_ext;
1794 	struct smc_clc_v2_extension *pclc_v2_ext;
1795 	int rc = SMC_CLC_DECL_PEERNOSMC;
1796 
1797 	ini->smc_type_v1 = pclc->hdr.typev1;
1798 	ini->smc_type_v2 = pclc->hdr.typev2;
1799 	ini->smcd_version = smcd_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
1800 	ini->smcr_version = smcr_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
1801 	if (pclc->hdr.version > SMC_V1) {
1802 		if (smcd_indicated(ini->smc_type_v2))
1803 			ini->smcd_version |= SMC_V2;
1804 		if (smcr_indicated(ini->smc_type_v2))
1805 			ini->smcr_version |= SMC_V2;
1806 	}
1807 	if (!(ini->smcd_version & SMC_V2) && !(ini->smcr_version & SMC_V2)) {
1808 		rc = SMC_CLC_DECL_PEERNOSMC;
1809 		goto out;
1810 	}
1811 	pclc_v2_ext = smc_get_clc_v2_ext(pclc);
1812 	if (!pclc_v2_ext) {
1813 		ini->smcd_version &= ~SMC_V2;
1814 		ini->smcr_version &= ~SMC_V2;
1815 		rc = SMC_CLC_DECL_NOV2EXT;
1816 		goto out;
1817 	}
1818 	pclc_smcd_v2_ext = smc_get_clc_smcd_v2_ext(pclc_v2_ext);
1819 	if (ini->smcd_version & SMC_V2) {
1820 		if (!smc_ism_is_v2_capable()) {
1821 			ini->smcd_version &= ~SMC_V2;
1822 			rc = SMC_CLC_DECL_NOISM2SUPP;
1823 		} else if (!pclc_smcd_v2_ext) {
1824 			ini->smcd_version &= ~SMC_V2;
1825 			rc = SMC_CLC_DECL_NOV2DEXT;
1826 		} else if (!pclc_v2_ext->hdr.eid_cnt &&
1827 			   !pclc_v2_ext->hdr.flag.seid) {
1828 			ini->smcd_version &= ~SMC_V2;
1829 			rc = SMC_CLC_DECL_NOUEID;
1830 		}
1831 	}
1832 	if (ini->smcr_version & SMC_V2) {
1833 		if (!pclc_v2_ext->hdr.eid_cnt) {
1834 			ini->smcr_version &= ~SMC_V2;
1835 			rc = SMC_CLC_DECL_NOUEID;
1836 		}
1837 	}
1838 
1839 out:
1840 	if (!ini->smcd_version && !ini->smcr_version)
1841 		return rc;
1842 
1843 	return 0;
1844 }
1845 
1846 /* listen worker: check prefixes */
1847 static int smc_listen_prfx_check(struct smc_sock *new_smc,
1848 				 struct smc_clc_msg_proposal *pclc)
1849 {
1850 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1851 	struct socket *newclcsock = new_smc->clcsock;
1852 
1853 	if (pclc->hdr.typev1 == SMC_TYPE_N)
1854 		return 0;
1855 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1856 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1857 		return SMC_CLC_DECL_DIFFPREFIX;
1858 
1859 	return 0;
1860 }
1861 
1862 /* listen worker: initialize connection and buffers */
1863 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1864 				struct smc_init_info *ini)
1865 {
1866 	int rc;
1867 
1868 	/* allocate connection / link group */
1869 	rc = smc_conn_create(new_smc, ini);
1870 	if (rc)
1871 		return rc;
1872 
1873 	/* create send buffer and rmb */
1874 	if (smc_buf_create(new_smc, false))
1875 		return SMC_CLC_DECL_MEM;
1876 
1877 	return 0;
1878 }
1879 
1880 /* listen worker: initialize connection and buffers for SMC-D */
1881 static int smc_listen_ism_init(struct smc_sock *new_smc,
1882 			       struct smc_init_info *ini)
1883 {
1884 	int rc;
1885 
1886 	rc = smc_conn_create(new_smc, ini);
1887 	if (rc)
1888 		return rc;
1889 
1890 	/* Create send and receive buffers */
1891 	rc = smc_buf_create(new_smc, true);
1892 	if (rc) {
1893 		smc_conn_abort(new_smc, ini->first_contact_local);
1894 		return (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB :
1895 					 SMC_CLC_DECL_MEM;
1896 	}
1897 
1898 	return 0;
1899 }
1900 
1901 static bool smc_is_already_selected(struct smcd_dev *smcd,
1902 				    struct smc_init_info *ini,
1903 				    int matches)
1904 {
1905 	int i;
1906 
1907 	for (i = 0; i < matches; i++)
1908 		if (smcd == ini->ism_dev[i])
1909 			return true;
1910 
1911 	return false;
1912 }
1913 
1914 /* check for ISM devices matching proposed ISM devices */
1915 static void smc_check_ism_v2_match(struct smc_init_info *ini,
1916 				   u16 proposed_chid, u64 proposed_gid,
1917 				   unsigned int *matches)
1918 {
1919 	struct smcd_dev *smcd;
1920 
1921 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
1922 		if (smcd->going_away)
1923 			continue;
1924 		if (smc_is_already_selected(smcd, ini, *matches))
1925 			continue;
1926 		if (smc_ism_get_chid(smcd) == proposed_chid &&
1927 		    !smc_ism_cantalk(proposed_gid, ISM_RESERVED_VLANID, smcd)) {
1928 			ini->ism_peer_gid[*matches] = proposed_gid;
1929 			ini->ism_dev[*matches] = smcd;
1930 			(*matches)++;
1931 			break;
1932 		}
1933 	}
1934 }
1935 
1936 static void smc_find_ism_store_rc(u32 rc, struct smc_init_info *ini)
1937 {
1938 	if (!ini->rc)
1939 		ini->rc = rc;
1940 }
1941 
1942 static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
1943 					struct smc_clc_msg_proposal *pclc,
1944 					struct smc_init_info *ini)
1945 {
1946 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
1947 	struct smc_clc_v2_extension *smc_v2_ext;
1948 	struct smc_clc_msg_smcd *pclc_smcd;
1949 	unsigned int matches = 0;
1950 	u8 smcd_version;
1951 	u8 *eid = NULL;
1952 	int i, rc;
1953 
1954 	if (!(ini->smcd_version & SMC_V2) || !smcd_indicated(ini->smc_type_v2))
1955 		goto not_found;
1956 
1957 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
1958 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
1959 	smcd_v2_ext = smc_get_clc_smcd_v2_ext(smc_v2_ext);
1960 
1961 	mutex_lock(&smcd_dev_list.mutex);
1962 	if (pclc_smcd->ism.chid)
1963 		/* check for ISM device matching proposed native ISM device */
1964 		smc_check_ism_v2_match(ini, ntohs(pclc_smcd->ism.chid),
1965 				       ntohll(pclc_smcd->ism.gid), &matches);
1966 	for (i = 1; i <= smc_v2_ext->hdr.ism_gid_cnt; i++) {
1967 		/* check for ISM devices matching proposed non-native ISM
1968 		 * devices
1969 		 */
1970 		smc_check_ism_v2_match(ini,
1971 				       ntohs(smcd_v2_ext->gidchid[i - 1].chid),
1972 				       ntohll(smcd_v2_ext->gidchid[i - 1].gid),
1973 				       &matches);
1974 	}
1975 	mutex_unlock(&smcd_dev_list.mutex);
1976 
1977 	if (!ini->ism_dev[0]) {
1978 		smc_find_ism_store_rc(SMC_CLC_DECL_NOSMCD2DEV, ini);
1979 		goto not_found;
1980 	}
1981 
1982 	smc_ism_get_system_eid(&eid);
1983 	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext,
1984 			       smcd_v2_ext->system_eid, eid))
1985 		goto not_found;
1986 
1987 	/* separate - outside the smcd_dev_list.lock */
1988 	smcd_version = ini->smcd_version;
1989 	for (i = 0; i < matches; i++) {
1990 		ini->smcd_version = SMC_V2;
1991 		ini->is_smcd = true;
1992 		ini->ism_selected = i;
1993 		rc = smc_listen_ism_init(new_smc, ini);
1994 		if (rc) {
1995 			smc_find_ism_store_rc(rc, ini);
1996 			/* try next active ISM device */
1997 			continue;
1998 		}
1999 		return; /* matching and usable V2 ISM device found */
2000 	}
2001 	/* no V2 ISM device could be initialized */
2002 	ini->smcd_version = smcd_version;	/* restore original value */
2003 	ini->negotiated_eid[0] = 0;
2004 
2005 not_found:
2006 	ini->smcd_version &= ~SMC_V2;
2007 	ini->ism_dev[0] = NULL;
2008 	ini->is_smcd = false;
2009 }
2010 
2011 static void smc_find_ism_v1_device_serv(struct smc_sock *new_smc,
2012 					struct smc_clc_msg_proposal *pclc,
2013 					struct smc_init_info *ini)
2014 {
2015 	struct smc_clc_msg_smcd *pclc_smcd = smc_get_clc_msg_smcd(pclc);
2016 	int rc = 0;
2017 
2018 	/* check if ISM V1 is available */
2019 	if (!(ini->smcd_version & SMC_V1) || !smcd_indicated(ini->smc_type_v1))
2020 		goto not_found;
2021 	ini->is_smcd = true; /* prepare ISM check */
2022 	ini->ism_peer_gid[0] = ntohll(pclc_smcd->ism.gid);
2023 	rc = smc_find_ism_device(new_smc, ini);
2024 	if (rc)
2025 		goto not_found;
2026 	ini->ism_selected = 0;
2027 	rc = smc_listen_ism_init(new_smc, ini);
2028 	if (!rc)
2029 		return;		/* V1 ISM device found */
2030 
2031 not_found:
2032 	smc_find_ism_store_rc(rc, ini);
2033 	ini->smcd_version &= ~SMC_V1;
2034 	ini->ism_dev[0] = NULL;
2035 	ini->is_smcd = false;
2036 }
2037 
2038 /* listen worker: register buffers */
2039 static int smc_listen_rdma_reg(struct smc_sock *new_smc, bool local_first)
2040 {
2041 	struct smc_connection *conn = &new_smc->conn;
2042 
2043 	if (!local_first) {
2044 		if (smcr_lgr_reg_rmbs(conn->lnk, conn->rmb_desc))
2045 			return SMC_CLC_DECL_ERR_REGRMB;
2046 	}
2047 	smc_rmb_sync_sg_for_device(&new_smc->conn);
2048 
2049 	return 0;
2050 }
2051 
2052 static void smc_find_rdma_v2_device_serv(struct smc_sock *new_smc,
2053 					 struct smc_clc_msg_proposal *pclc,
2054 					 struct smc_init_info *ini)
2055 {
2056 	struct smc_clc_v2_extension *smc_v2_ext;
2057 	u8 smcr_version;
2058 	int rc;
2059 
2060 	if (!(ini->smcr_version & SMC_V2) || !smcr_indicated(ini->smc_type_v2))
2061 		goto not_found;
2062 
2063 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
2064 	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext, NULL, NULL))
2065 		goto not_found;
2066 
2067 	/* prepare RDMA check */
2068 	memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
2069 	memcpy(ini->peer_gid, smc_v2_ext->roce, SMC_GID_SIZE);
2070 	memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
2071 	ini->check_smcrv2 = true;
2072 	ini->smcrv2.clc_sk = new_smc->clcsock->sk;
2073 	ini->smcrv2.saddr = new_smc->clcsock->sk->sk_rcv_saddr;
2074 	ini->smcrv2.daddr = smc_ib_gid_to_ipv4(smc_v2_ext->roce);
2075 	rc = smc_find_rdma_device(new_smc, ini);
2076 	if (rc) {
2077 		smc_find_ism_store_rc(rc, ini);
2078 		goto not_found;
2079 	}
2080 	if (!ini->smcrv2.uses_gateway)
2081 		memcpy(ini->smcrv2.nexthop_mac, pclc->lcl.mac, ETH_ALEN);
2082 
2083 	smcr_version = ini->smcr_version;
2084 	ini->smcr_version = SMC_V2;
2085 	rc = smc_listen_rdma_init(new_smc, ini);
2086 	if (!rc)
2087 		rc = smc_listen_rdma_reg(new_smc, ini->first_contact_local);
2088 	if (!rc)
2089 		return;
2090 	ini->smcr_version = smcr_version;
2091 	smc_find_ism_store_rc(rc, ini);
2092 
2093 not_found:
2094 	ini->smcr_version &= ~SMC_V2;
2095 	ini->check_smcrv2 = false;
2096 }
2097 
2098 static int smc_find_rdma_v1_device_serv(struct smc_sock *new_smc,
2099 					struct smc_clc_msg_proposal *pclc,
2100 					struct smc_init_info *ini)
2101 {
2102 	int rc;
2103 
2104 	if (!(ini->smcr_version & SMC_V1) || !smcr_indicated(ini->smc_type_v1))
2105 		return SMC_CLC_DECL_NOSMCDEV;
2106 
2107 	/* prepare RDMA check */
2108 	memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
2109 	memcpy(ini->peer_gid, pclc->lcl.gid, SMC_GID_SIZE);
2110 	memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
2111 	rc = smc_find_rdma_device(new_smc, ini);
2112 	if (rc) {
2113 		/* no RDMA device found */
2114 		return SMC_CLC_DECL_NOSMCDEV;
2115 	}
2116 	rc = smc_listen_rdma_init(new_smc, ini);
2117 	if (rc)
2118 		return rc;
2119 	return smc_listen_rdma_reg(new_smc, ini->first_contact_local);
2120 }
2121 
2122 /* determine the local device matching to proposal */
2123 static int smc_listen_find_device(struct smc_sock *new_smc,
2124 				  struct smc_clc_msg_proposal *pclc,
2125 				  struct smc_init_info *ini)
2126 {
2127 	int prfx_rc;
2128 
2129 	/* check for ISM device matching V2 proposed device */
2130 	smc_find_ism_v2_device_serv(new_smc, pclc, ini);
2131 	if (ini->ism_dev[0])
2132 		return 0;
2133 
2134 	/* check for matching IP prefix and subnet length (V1) */
2135 	prfx_rc = smc_listen_prfx_check(new_smc, pclc);
2136 	if (prfx_rc)
2137 		smc_find_ism_store_rc(prfx_rc, ini);
2138 
2139 	/* get vlan id from IP device */
2140 	if (smc_vlan_by_tcpsk(new_smc->clcsock, ini))
2141 		return ini->rc ?: SMC_CLC_DECL_GETVLANERR;
2142 
2143 	/* check for ISM device matching V1 proposed device */
2144 	if (!prfx_rc)
2145 		smc_find_ism_v1_device_serv(new_smc, pclc, ini);
2146 	if (ini->ism_dev[0])
2147 		return 0;
2148 
2149 	if (!smcr_indicated(pclc->hdr.typev1) &&
2150 	    !smcr_indicated(pclc->hdr.typev2))
2151 		/* skip RDMA and decline */
2152 		return ini->rc ?: SMC_CLC_DECL_NOSMCDDEV;
2153 
2154 	/* check if RDMA V2 is available */
2155 	smc_find_rdma_v2_device_serv(new_smc, pclc, ini);
2156 	if (ini->smcrv2.ib_dev_v2)
2157 		return 0;
2158 
2159 	/* check if RDMA V1 is available */
2160 	if (!prfx_rc) {
2161 		int rc;
2162 
2163 		rc = smc_find_rdma_v1_device_serv(new_smc, pclc, ini);
2164 		smc_find_ism_store_rc(rc, ini);
2165 		return (!rc) ? 0 : ini->rc;
2166 	}
2167 	return SMC_CLC_DECL_NOSMCDEV;
2168 }
2169 
2170 /* listen worker: finish RDMA setup */
2171 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
2172 				  struct smc_clc_msg_accept_confirm *cclc,
2173 				  bool local_first,
2174 				  struct smc_init_info *ini)
2175 {
2176 	struct smc_link *link = new_smc->conn.lnk;
2177 	int reason_code = 0;
2178 
2179 	if (local_first)
2180 		smc_link_save_peer_info(link, cclc, ini);
2181 
2182 	if (smc_rmb_rtoken_handling(&new_smc->conn, link, cclc))
2183 		return SMC_CLC_DECL_ERR_RTOK;
2184 
2185 	if (local_first) {
2186 		if (smc_ib_ready_link(link))
2187 			return SMC_CLC_DECL_ERR_RDYLNK;
2188 		/* QP confirmation over RoCE fabric */
2189 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
2190 		reason_code = smcr_serv_conf_first_link(new_smc);
2191 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
2192 	}
2193 	return reason_code;
2194 }
2195 
2196 /* setup for connection of server */
2197 static void smc_listen_work(struct work_struct *work)
2198 {
2199 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
2200 						smc_listen_work);
2201 	struct socket *newclcsock = new_smc->clcsock;
2202 	struct smc_clc_msg_accept_confirm *cclc;
2203 	struct smc_clc_msg_proposal_area *buf;
2204 	struct smc_clc_msg_proposal *pclc;
2205 	struct smc_init_info *ini = NULL;
2206 	u8 proposal_version = SMC_V1;
2207 	u8 accept_version;
2208 	int rc = 0;
2209 
2210 	if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
2211 		return smc_listen_out_err(new_smc);
2212 
2213 	if (new_smc->use_fallback) {
2214 		smc_listen_out_connected(new_smc);
2215 		return;
2216 	}
2217 
2218 	/* check if peer is smc capable */
2219 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
2220 		rc = smc_switch_to_fallback(new_smc, SMC_CLC_DECL_PEERNOSMC);
2221 		if (rc)
2222 			smc_listen_out_err(new_smc);
2223 		else
2224 			smc_listen_out_connected(new_smc);
2225 		return;
2226 	}
2227 
2228 	/* do inband token exchange -
2229 	 * wait for and receive SMC Proposal CLC message
2230 	 */
2231 	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
2232 	if (!buf) {
2233 		rc = SMC_CLC_DECL_MEM;
2234 		goto out_decl;
2235 	}
2236 	pclc = (struct smc_clc_msg_proposal *)buf;
2237 	rc = smc_clc_wait_msg(new_smc, pclc, sizeof(*buf),
2238 			      SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
2239 	if (rc)
2240 		goto out_decl;
2241 
2242 	if (pclc->hdr.version > SMC_V1)
2243 		proposal_version = SMC_V2;
2244 
2245 	/* IPSec connections opt out of SMC optimizations */
2246 	if (using_ipsec(new_smc)) {
2247 		rc = SMC_CLC_DECL_IPSEC;
2248 		goto out_decl;
2249 	}
2250 
2251 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
2252 	if (!ini) {
2253 		rc = SMC_CLC_DECL_MEM;
2254 		goto out_decl;
2255 	}
2256 
2257 	/* initial version checking */
2258 	rc = smc_listen_v2_check(new_smc, pclc, ini);
2259 	if (rc)
2260 		goto out_decl;
2261 
2262 	mutex_lock(&smc_server_lgr_pending);
2263 	smc_close_init(new_smc);
2264 	smc_rx_init(new_smc);
2265 	smc_tx_init(new_smc);
2266 
2267 	/* determine ISM or RoCE device used for connection */
2268 	rc = smc_listen_find_device(new_smc, pclc, ini);
2269 	if (rc)
2270 		goto out_unlock;
2271 
2272 	/* send SMC Accept CLC message */
2273 	accept_version = ini->is_smcd ? ini->smcd_version : ini->smcr_version;
2274 	rc = smc_clc_send_accept(new_smc, ini->first_contact_local,
2275 				 accept_version, ini->negotiated_eid);
2276 	if (rc)
2277 		goto out_unlock;
2278 
2279 	/* SMC-D does not need this lock any more */
2280 	if (ini->is_smcd)
2281 		mutex_unlock(&smc_server_lgr_pending);
2282 
2283 	/* receive SMC Confirm CLC message */
2284 	memset(buf, 0, sizeof(*buf));
2285 	cclc = (struct smc_clc_msg_accept_confirm *)buf;
2286 	rc = smc_clc_wait_msg(new_smc, cclc, sizeof(*buf),
2287 			      SMC_CLC_CONFIRM, CLC_WAIT_TIME);
2288 	if (rc) {
2289 		if (!ini->is_smcd)
2290 			goto out_unlock;
2291 		goto out_decl;
2292 	}
2293 
2294 	/* finish worker */
2295 	if (!ini->is_smcd) {
2296 		rc = smc_listen_rdma_finish(new_smc, cclc,
2297 					    ini->first_contact_local, ini);
2298 		if (rc)
2299 			goto out_unlock;
2300 		mutex_unlock(&smc_server_lgr_pending);
2301 	}
2302 	smc_conn_save_peer_info(new_smc, cclc);
2303 	smc_listen_out_connected(new_smc);
2304 	SMC_STAT_SERV_SUCC_INC(sock_net(newclcsock->sk), ini);
2305 	goto out_free;
2306 
2307 out_unlock:
2308 	mutex_unlock(&smc_server_lgr_pending);
2309 out_decl:
2310 	smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0,
2311 			   proposal_version);
2312 out_free:
2313 	kfree(ini);
2314 	kfree(buf);
2315 }
2316 
2317 static void smc_tcp_listen_work(struct work_struct *work)
2318 {
2319 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
2320 					     tcp_listen_work);
2321 	struct sock *lsk = &lsmc->sk;
2322 	struct smc_sock *new_smc;
2323 	int rc = 0;
2324 
2325 	lock_sock(lsk);
2326 	while (lsk->sk_state == SMC_LISTEN) {
2327 		rc = smc_clcsock_accept(lsmc, &new_smc);
2328 		if (rc) /* clcsock accept queue empty or error */
2329 			goto out;
2330 		if (!new_smc)
2331 			continue;
2332 
2333 		if (tcp_sk(new_smc->clcsock->sk)->syn_smc)
2334 			atomic_inc(&lsmc->queued_smc_hs);
2335 
2336 		new_smc->listen_smc = lsmc;
2337 		new_smc->use_fallback = lsmc->use_fallback;
2338 		new_smc->fallback_rsn = lsmc->fallback_rsn;
2339 		sock_hold(lsk); /* sock_put in smc_listen_work */
2340 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
2341 		smc_copy_sock_settings_to_smc(new_smc);
2342 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
2343 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
2344 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
2345 		if (!queue_work(smc_hs_wq, &new_smc->smc_listen_work))
2346 			sock_put(&new_smc->sk);
2347 	}
2348 
2349 out:
2350 	release_sock(lsk);
2351 	sock_put(&lsmc->sk); /* sock_hold in smc_clcsock_data_ready() */
2352 }
2353 
2354 static void smc_clcsock_data_ready(struct sock *listen_clcsock)
2355 {
2356 	struct smc_sock *lsmc =
2357 		smc_clcsock_user_data(listen_clcsock);
2358 
2359 	if (!lsmc)
2360 		return;
2361 	lsmc->clcsk_data_ready(listen_clcsock);
2362 	if (lsmc->sk.sk_state == SMC_LISTEN) {
2363 		sock_hold(&lsmc->sk); /* sock_put in smc_tcp_listen_work() */
2364 		if (!queue_work(smc_tcp_ls_wq, &lsmc->tcp_listen_work))
2365 			sock_put(&lsmc->sk);
2366 	}
2367 }
2368 
2369 static int smc_listen(struct socket *sock, int backlog)
2370 {
2371 	struct sock *sk = sock->sk;
2372 	struct smc_sock *smc;
2373 	int rc;
2374 
2375 	smc = smc_sk(sk);
2376 	lock_sock(sk);
2377 
2378 	rc = -EINVAL;
2379 	if ((sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) ||
2380 	    smc->connect_nonblock)
2381 		goto out;
2382 
2383 	rc = 0;
2384 	if (sk->sk_state == SMC_LISTEN) {
2385 		sk->sk_max_ack_backlog = backlog;
2386 		goto out;
2387 	}
2388 	/* some socket options are handled in core, so we could not apply
2389 	 * them to the clc socket -- copy smc socket options to clc socket
2390 	 */
2391 	smc_copy_sock_settings_to_clc(smc);
2392 	if (!smc->use_fallback)
2393 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
2394 
2395 	/* save original sk_data_ready function and establish
2396 	 * smc-specific sk_data_ready function
2397 	 */
2398 	smc->clcsk_data_ready = smc->clcsock->sk->sk_data_ready;
2399 	smc->clcsock->sk->sk_data_ready = smc_clcsock_data_ready;
2400 	smc->clcsock->sk->sk_user_data =
2401 		(void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
2402 
2403 	/* save original ops */
2404 	smc->ori_af_ops = inet_csk(smc->clcsock->sk)->icsk_af_ops;
2405 
2406 	smc->af_ops = *smc->ori_af_ops;
2407 	smc->af_ops.syn_recv_sock = smc_tcp_syn_recv_sock;
2408 
2409 	inet_csk(smc->clcsock->sk)->icsk_af_ops = &smc->af_ops;
2410 
2411 	if (smc->limit_smc_hs)
2412 		tcp_sk(smc->clcsock->sk)->smc_hs_congested = smc_hs_congested;
2413 
2414 	rc = kernel_listen(smc->clcsock, backlog);
2415 	if (rc) {
2416 		smc->clcsock->sk->sk_data_ready = smc->clcsk_data_ready;
2417 		goto out;
2418 	}
2419 	sk->sk_max_ack_backlog = backlog;
2420 	sk->sk_ack_backlog = 0;
2421 	sk->sk_state = SMC_LISTEN;
2422 
2423 out:
2424 	release_sock(sk);
2425 	return rc;
2426 }
2427 
2428 static int smc_accept(struct socket *sock, struct socket *new_sock,
2429 		      int flags, bool kern)
2430 {
2431 	struct sock *sk = sock->sk, *nsk;
2432 	DECLARE_WAITQUEUE(wait, current);
2433 	struct smc_sock *lsmc;
2434 	long timeo;
2435 	int rc = 0;
2436 
2437 	lsmc = smc_sk(sk);
2438 	sock_hold(sk); /* sock_put below */
2439 	lock_sock(sk);
2440 
2441 	if (lsmc->sk.sk_state != SMC_LISTEN) {
2442 		rc = -EINVAL;
2443 		release_sock(sk);
2444 		goto out;
2445 	}
2446 
2447 	/* Wait for an incoming connection */
2448 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
2449 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
2450 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
2451 		set_current_state(TASK_INTERRUPTIBLE);
2452 		if (!timeo) {
2453 			rc = -EAGAIN;
2454 			break;
2455 		}
2456 		release_sock(sk);
2457 		timeo = schedule_timeout(timeo);
2458 		/* wakeup by sk_data_ready in smc_listen_work() */
2459 		sched_annotate_sleep();
2460 		lock_sock(sk);
2461 		if (signal_pending(current)) {
2462 			rc = sock_intr_errno(timeo);
2463 			break;
2464 		}
2465 	}
2466 	set_current_state(TASK_RUNNING);
2467 	remove_wait_queue(sk_sleep(sk), &wait);
2468 
2469 	if (!rc)
2470 		rc = sock_error(nsk);
2471 	release_sock(sk);
2472 	if (rc)
2473 		goto out;
2474 
2475 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
2476 		/* wait till data arrives on the socket */
2477 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
2478 								MSEC_PER_SEC);
2479 		if (smc_sk(nsk)->use_fallback) {
2480 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
2481 
2482 			lock_sock(clcsk);
2483 			if (skb_queue_empty(&clcsk->sk_receive_queue))
2484 				sk_wait_data(clcsk, &timeo, NULL);
2485 			release_sock(clcsk);
2486 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
2487 			lock_sock(nsk);
2488 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
2489 			release_sock(nsk);
2490 		}
2491 	}
2492 
2493 out:
2494 	sock_put(sk); /* sock_hold above */
2495 	return rc;
2496 }
2497 
2498 static int smc_getname(struct socket *sock, struct sockaddr *addr,
2499 		       int peer)
2500 {
2501 	struct smc_sock *smc;
2502 
2503 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
2504 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
2505 		return -ENOTCONN;
2506 
2507 	smc = smc_sk(sock->sk);
2508 
2509 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
2510 }
2511 
2512 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2513 {
2514 	struct sock *sk = sock->sk;
2515 	struct smc_sock *smc;
2516 	int rc = -EPIPE;
2517 
2518 	smc = smc_sk(sk);
2519 	lock_sock(sk);
2520 	if ((sk->sk_state != SMC_ACTIVE) &&
2521 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2522 	    (sk->sk_state != SMC_INIT))
2523 		goto out;
2524 
2525 	if (msg->msg_flags & MSG_FASTOPEN) {
2526 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2527 			rc = smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2528 			if (rc)
2529 				goto out;
2530 		} else {
2531 			rc = -EINVAL;
2532 			goto out;
2533 		}
2534 	}
2535 
2536 	if (smc->use_fallback) {
2537 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
2538 	} else {
2539 		rc = smc_tx_sendmsg(smc, msg, len);
2540 		SMC_STAT_TX_PAYLOAD(smc, len, rc);
2541 	}
2542 out:
2543 	release_sock(sk);
2544 	return rc;
2545 }
2546 
2547 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2548 		       int flags)
2549 {
2550 	struct sock *sk = sock->sk;
2551 	struct smc_sock *smc;
2552 	int rc = -ENOTCONN;
2553 
2554 	smc = smc_sk(sk);
2555 	lock_sock(sk);
2556 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2557 		/* socket was connected before, no more data to read */
2558 		rc = 0;
2559 		goto out;
2560 	}
2561 	if ((sk->sk_state == SMC_INIT) ||
2562 	    (sk->sk_state == SMC_LISTEN) ||
2563 	    (sk->sk_state == SMC_CLOSED))
2564 		goto out;
2565 
2566 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2567 		rc = 0;
2568 		goto out;
2569 	}
2570 
2571 	if (smc->use_fallback) {
2572 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
2573 	} else {
2574 		msg->msg_namelen = 0;
2575 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
2576 		SMC_STAT_RX_PAYLOAD(smc, rc, rc);
2577 	}
2578 
2579 out:
2580 	release_sock(sk);
2581 	return rc;
2582 }
2583 
2584 static __poll_t smc_accept_poll(struct sock *parent)
2585 {
2586 	struct smc_sock *isk = smc_sk(parent);
2587 	__poll_t mask = 0;
2588 
2589 	spin_lock(&isk->accept_q_lock);
2590 	if (!list_empty(&isk->accept_q))
2591 		mask = EPOLLIN | EPOLLRDNORM;
2592 	spin_unlock(&isk->accept_q_lock);
2593 
2594 	return mask;
2595 }
2596 
2597 static __poll_t smc_poll(struct file *file, struct socket *sock,
2598 			     poll_table *wait)
2599 {
2600 	struct sock *sk = sock->sk;
2601 	struct smc_sock *smc;
2602 	__poll_t mask = 0;
2603 
2604 	if (!sk)
2605 		return EPOLLNVAL;
2606 
2607 	smc = smc_sk(sock->sk);
2608 	if (smc->use_fallback) {
2609 		/* delegate to CLC child sock */
2610 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
2611 		sk->sk_err = smc->clcsock->sk->sk_err;
2612 	} else {
2613 		if (sk->sk_state != SMC_CLOSED)
2614 			sock_poll_wait(file, sock, wait);
2615 		if (sk->sk_err)
2616 			mask |= EPOLLERR;
2617 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
2618 		    (sk->sk_state == SMC_CLOSED))
2619 			mask |= EPOLLHUP;
2620 		if (sk->sk_state == SMC_LISTEN) {
2621 			/* woken up by sk_data_ready in smc_listen_work() */
2622 			mask |= smc_accept_poll(sk);
2623 		} else if (smc->use_fallback) { /* as result of connect_work()*/
2624 			mask |= smc->clcsock->ops->poll(file, smc->clcsock,
2625 							   wait);
2626 			sk->sk_err = smc->clcsock->sk->sk_err;
2627 		} else {
2628 			if ((sk->sk_state != SMC_INIT &&
2629 			     atomic_read(&smc->conn.sndbuf_space)) ||
2630 			    sk->sk_shutdown & SEND_SHUTDOWN) {
2631 				mask |= EPOLLOUT | EPOLLWRNORM;
2632 			} else {
2633 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2634 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2635 			}
2636 			if (atomic_read(&smc->conn.bytes_to_rcv))
2637 				mask |= EPOLLIN | EPOLLRDNORM;
2638 			if (sk->sk_shutdown & RCV_SHUTDOWN)
2639 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
2640 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
2641 				mask |= EPOLLIN;
2642 			if (smc->conn.urg_state == SMC_URG_VALID)
2643 				mask |= EPOLLPRI;
2644 		}
2645 	}
2646 
2647 	return mask;
2648 }
2649 
2650 static int smc_shutdown(struct socket *sock, int how)
2651 {
2652 	struct sock *sk = sock->sk;
2653 	bool do_shutdown = true;
2654 	struct smc_sock *smc;
2655 	int rc = -EINVAL;
2656 	int old_state;
2657 	int rc1 = 0;
2658 
2659 	smc = smc_sk(sk);
2660 
2661 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
2662 		return rc;
2663 
2664 	lock_sock(sk);
2665 
2666 	rc = -ENOTCONN;
2667 	if ((sk->sk_state != SMC_ACTIVE) &&
2668 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
2669 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
2670 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2671 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
2672 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
2673 		goto out;
2674 	if (smc->use_fallback) {
2675 		rc = kernel_sock_shutdown(smc->clcsock, how);
2676 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
2677 		if (sk->sk_shutdown == SHUTDOWN_MASK)
2678 			sk->sk_state = SMC_CLOSED;
2679 		goto out;
2680 	}
2681 	switch (how) {
2682 	case SHUT_RDWR:		/* shutdown in both directions */
2683 		old_state = sk->sk_state;
2684 		rc = smc_close_active(smc);
2685 		if (old_state == SMC_ACTIVE &&
2686 		    sk->sk_state == SMC_PEERCLOSEWAIT1)
2687 			do_shutdown = false;
2688 		break;
2689 	case SHUT_WR:
2690 		rc = smc_close_shutdown_write(smc);
2691 		break;
2692 	case SHUT_RD:
2693 		rc = 0;
2694 		/* nothing more to do because peer is not involved */
2695 		break;
2696 	}
2697 	if (do_shutdown && smc->clcsock)
2698 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
2699 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
2700 	sk->sk_shutdown |= how + 1;
2701 
2702 out:
2703 	release_sock(sk);
2704 	return rc ? rc : rc1;
2705 }
2706 
2707 static int __smc_getsockopt(struct socket *sock, int level, int optname,
2708 			    char __user *optval, int __user *optlen)
2709 {
2710 	struct smc_sock *smc;
2711 	int val, len;
2712 
2713 	smc = smc_sk(sock->sk);
2714 
2715 	if (get_user(len, optlen))
2716 		return -EFAULT;
2717 
2718 	len = min_t(int, len, sizeof(int));
2719 
2720 	if (len < 0)
2721 		return -EINVAL;
2722 
2723 	switch (optname) {
2724 	case SMC_LIMIT_HS:
2725 		val = smc->limit_smc_hs;
2726 		break;
2727 	default:
2728 		return -EOPNOTSUPP;
2729 	}
2730 
2731 	if (put_user(len, optlen))
2732 		return -EFAULT;
2733 	if (copy_to_user(optval, &val, len))
2734 		return -EFAULT;
2735 
2736 	return 0;
2737 }
2738 
2739 static int __smc_setsockopt(struct socket *sock, int level, int optname,
2740 			    sockptr_t optval, unsigned int optlen)
2741 {
2742 	struct sock *sk = sock->sk;
2743 	struct smc_sock *smc;
2744 	int val, rc;
2745 
2746 	smc = smc_sk(sk);
2747 
2748 	lock_sock(sk);
2749 	switch (optname) {
2750 	case SMC_LIMIT_HS:
2751 		if (optlen < sizeof(int)) {
2752 			rc = -EINVAL;
2753 			break;
2754 		}
2755 		if (copy_from_sockptr(&val, optval, sizeof(int))) {
2756 			rc = -EFAULT;
2757 			break;
2758 		}
2759 
2760 		smc->limit_smc_hs = !!val;
2761 		rc = 0;
2762 		break;
2763 	default:
2764 		rc = -EOPNOTSUPP;
2765 		break;
2766 	}
2767 	release_sock(sk);
2768 
2769 	return rc;
2770 }
2771 
2772 static int smc_setsockopt(struct socket *sock, int level, int optname,
2773 			  sockptr_t optval, unsigned int optlen)
2774 {
2775 	struct sock *sk = sock->sk;
2776 	struct smc_sock *smc;
2777 	int val, rc;
2778 
2779 	if (level == SOL_TCP && optname == TCP_ULP)
2780 		return -EOPNOTSUPP;
2781 	else if (level == SOL_SMC)
2782 		return __smc_setsockopt(sock, level, optname, optval, optlen);
2783 
2784 	smc = smc_sk(sk);
2785 
2786 	/* generic setsockopts reaching us here always apply to the
2787 	 * CLC socket
2788 	 */
2789 	mutex_lock(&smc->clcsock_release_lock);
2790 	if (!smc->clcsock) {
2791 		mutex_unlock(&smc->clcsock_release_lock);
2792 		return -EBADF;
2793 	}
2794 	if (unlikely(!smc->clcsock->ops->setsockopt))
2795 		rc = -EOPNOTSUPP;
2796 	else
2797 		rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
2798 						   optval, optlen);
2799 	if (smc->clcsock->sk->sk_err) {
2800 		sk->sk_err = smc->clcsock->sk->sk_err;
2801 		sk_error_report(sk);
2802 	}
2803 	mutex_unlock(&smc->clcsock_release_lock);
2804 
2805 	if (optlen < sizeof(int))
2806 		return -EINVAL;
2807 	if (copy_from_sockptr(&val, optval, sizeof(int)))
2808 		return -EFAULT;
2809 
2810 	lock_sock(sk);
2811 	if (rc || smc->use_fallback)
2812 		goto out;
2813 	switch (optname) {
2814 	case TCP_FASTOPEN:
2815 	case TCP_FASTOPEN_CONNECT:
2816 	case TCP_FASTOPEN_KEY:
2817 	case TCP_FASTOPEN_NO_COOKIE:
2818 		/* option not supported by SMC */
2819 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2820 			rc = smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2821 		} else {
2822 			rc = -EINVAL;
2823 		}
2824 		break;
2825 	case TCP_NODELAY:
2826 		if (sk->sk_state != SMC_INIT &&
2827 		    sk->sk_state != SMC_LISTEN &&
2828 		    sk->sk_state != SMC_CLOSED) {
2829 			if (val) {
2830 				SMC_STAT_INC(smc, ndly_cnt);
2831 				smc_tx_pending(&smc->conn);
2832 				cancel_delayed_work(&smc->conn.tx_work);
2833 			}
2834 		}
2835 		break;
2836 	case TCP_CORK:
2837 		if (sk->sk_state != SMC_INIT &&
2838 		    sk->sk_state != SMC_LISTEN &&
2839 		    sk->sk_state != SMC_CLOSED) {
2840 			if (!val) {
2841 				SMC_STAT_INC(smc, cork_cnt);
2842 				smc_tx_pending(&smc->conn);
2843 				cancel_delayed_work(&smc->conn.tx_work);
2844 			}
2845 		}
2846 		break;
2847 	case TCP_DEFER_ACCEPT:
2848 		smc->sockopt_defer_accept = val;
2849 		break;
2850 	default:
2851 		break;
2852 	}
2853 out:
2854 	release_sock(sk);
2855 
2856 	return rc;
2857 }
2858 
2859 static int smc_getsockopt(struct socket *sock, int level, int optname,
2860 			  char __user *optval, int __user *optlen)
2861 {
2862 	struct smc_sock *smc;
2863 	int rc;
2864 
2865 	if (level == SOL_SMC)
2866 		return __smc_getsockopt(sock, level, optname, optval, optlen);
2867 
2868 	smc = smc_sk(sock->sk);
2869 	mutex_lock(&smc->clcsock_release_lock);
2870 	if (!smc->clcsock) {
2871 		mutex_unlock(&smc->clcsock_release_lock);
2872 		return -EBADF;
2873 	}
2874 	/* socket options apply to the CLC socket */
2875 	if (unlikely(!smc->clcsock->ops->getsockopt)) {
2876 		mutex_unlock(&smc->clcsock_release_lock);
2877 		return -EOPNOTSUPP;
2878 	}
2879 	rc = smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
2880 					   optval, optlen);
2881 	mutex_unlock(&smc->clcsock_release_lock);
2882 	return rc;
2883 }
2884 
2885 static int smc_ioctl(struct socket *sock, unsigned int cmd,
2886 		     unsigned long arg)
2887 {
2888 	union smc_host_cursor cons, urg;
2889 	struct smc_connection *conn;
2890 	struct smc_sock *smc;
2891 	int answ;
2892 
2893 	smc = smc_sk(sock->sk);
2894 	conn = &smc->conn;
2895 	lock_sock(&smc->sk);
2896 	if (smc->use_fallback) {
2897 		if (!smc->clcsock) {
2898 			release_sock(&smc->sk);
2899 			return -EBADF;
2900 		}
2901 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
2902 		release_sock(&smc->sk);
2903 		return answ;
2904 	}
2905 	switch (cmd) {
2906 	case SIOCINQ: /* same as FIONREAD */
2907 		if (smc->sk.sk_state == SMC_LISTEN) {
2908 			release_sock(&smc->sk);
2909 			return -EINVAL;
2910 		}
2911 		if (smc->sk.sk_state == SMC_INIT ||
2912 		    smc->sk.sk_state == SMC_CLOSED)
2913 			answ = 0;
2914 		else
2915 			answ = atomic_read(&smc->conn.bytes_to_rcv);
2916 		break;
2917 	case SIOCOUTQ:
2918 		/* output queue size (not send + not acked) */
2919 		if (smc->sk.sk_state == SMC_LISTEN) {
2920 			release_sock(&smc->sk);
2921 			return -EINVAL;
2922 		}
2923 		if (smc->sk.sk_state == SMC_INIT ||
2924 		    smc->sk.sk_state == SMC_CLOSED)
2925 			answ = 0;
2926 		else
2927 			answ = smc->conn.sndbuf_desc->len -
2928 					atomic_read(&smc->conn.sndbuf_space);
2929 		break;
2930 	case SIOCOUTQNSD:
2931 		/* output queue size (not send only) */
2932 		if (smc->sk.sk_state == SMC_LISTEN) {
2933 			release_sock(&smc->sk);
2934 			return -EINVAL;
2935 		}
2936 		if (smc->sk.sk_state == SMC_INIT ||
2937 		    smc->sk.sk_state == SMC_CLOSED)
2938 			answ = 0;
2939 		else
2940 			answ = smc_tx_prepared_sends(&smc->conn);
2941 		break;
2942 	case SIOCATMARK:
2943 		if (smc->sk.sk_state == SMC_LISTEN) {
2944 			release_sock(&smc->sk);
2945 			return -EINVAL;
2946 		}
2947 		if (smc->sk.sk_state == SMC_INIT ||
2948 		    smc->sk.sk_state == SMC_CLOSED) {
2949 			answ = 0;
2950 		} else {
2951 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
2952 			smc_curs_copy(&urg, &conn->urg_curs, conn);
2953 			answ = smc_curs_diff(conn->rmb_desc->len,
2954 					     &cons, &urg) == 1;
2955 		}
2956 		break;
2957 	default:
2958 		release_sock(&smc->sk);
2959 		return -ENOIOCTLCMD;
2960 	}
2961 	release_sock(&smc->sk);
2962 
2963 	return put_user(answ, (int __user *)arg);
2964 }
2965 
2966 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
2967 			    int offset, size_t size, int flags)
2968 {
2969 	struct sock *sk = sock->sk;
2970 	struct smc_sock *smc;
2971 	int rc = -EPIPE;
2972 
2973 	smc = smc_sk(sk);
2974 	lock_sock(sk);
2975 	if (sk->sk_state != SMC_ACTIVE) {
2976 		release_sock(sk);
2977 		goto out;
2978 	}
2979 	release_sock(sk);
2980 	if (smc->use_fallback) {
2981 		rc = kernel_sendpage(smc->clcsock, page, offset,
2982 				     size, flags);
2983 	} else {
2984 		lock_sock(sk);
2985 		rc = smc_tx_sendpage(smc, page, offset, size, flags);
2986 		release_sock(sk);
2987 		SMC_STAT_INC(smc, sendpage_cnt);
2988 	}
2989 
2990 out:
2991 	return rc;
2992 }
2993 
2994 /* Map the affected portions of the rmbe into an spd, note the number of bytes
2995  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
2996  * updates till whenever a respective page has been fully processed.
2997  * Note that subsequent recv() calls have to wait till all splice() processing
2998  * completed.
2999  */
3000 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
3001 			       struct pipe_inode_info *pipe, size_t len,
3002 			       unsigned int flags)
3003 {
3004 	struct sock *sk = sock->sk;
3005 	struct smc_sock *smc;
3006 	int rc = -ENOTCONN;
3007 
3008 	smc = smc_sk(sk);
3009 	lock_sock(sk);
3010 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
3011 		/* socket was connected before, no more data to read */
3012 		rc = 0;
3013 		goto out;
3014 	}
3015 	if (sk->sk_state == SMC_INIT ||
3016 	    sk->sk_state == SMC_LISTEN ||
3017 	    sk->sk_state == SMC_CLOSED)
3018 		goto out;
3019 
3020 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
3021 		rc = 0;
3022 		goto out;
3023 	}
3024 
3025 	if (smc->use_fallback) {
3026 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
3027 						    pipe, len, flags);
3028 	} else {
3029 		if (*ppos) {
3030 			rc = -ESPIPE;
3031 			goto out;
3032 		}
3033 		if (flags & SPLICE_F_NONBLOCK)
3034 			flags = MSG_DONTWAIT;
3035 		else
3036 			flags = 0;
3037 		SMC_STAT_INC(smc, splice_cnt);
3038 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
3039 	}
3040 out:
3041 	release_sock(sk);
3042 
3043 	return rc;
3044 }
3045 
3046 /* must look like tcp */
3047 static const struct proto_ops smc_sock_ops = {
3048 	.family		= PF_SMC,
3049 	.owner		= THIS_MODULE,
3050 	.release	= smc_release,
3051 	.bind		= smc_bind,
3052 	.connect	= smc_connect,
3053 	.socketpair	= sock_no_socketpair,
3054 	.accept		= smc_accept,
3055 	.getname	= smc_getname,
3056 	.poll		= smc_poll,
3057 	.ioctl		= smc_ioctl,
3058 	.listen		= smc_listen,
3059 	.shutdown	= smc_shutdown,
3060 	.setsockopt	= smc_setsockopt,
3061 	.getsockopt	= smc_getsockopt,
3062 	.sendmsg	= smc_sendmsg,
3063 	.recvmsg	= smc_recvmsg,
3064 	.mmap		= sock_no_mmap,
3065 	.sendpage	= smc_sendpage,
3066 	.splice_read	= smc_splice_read,
3067 };
3068 
3069 static int __smc_create(struct net *net, struct socket *sock, int protocol,
3070 			int kern, struct socket *clcsock)
3071 {
3072 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
3073 	struct smc_sock *smc;
3074 	struct sock *sk;
3075 	int rc;
3076 
3077 	rc = -ESOCKTNOSUPPORT;
3078 	if (sock->type != SOCK_STREAM)
3079 		goto out;
3080 
3081 	rc = -EPROTONOSUPPORT;
3082 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
3083 		goto out;
3084 
3085 	rc = -ENOBUFS;
3086 	sock->ops = &smc_sock_ops;
3087 	sk = smc_sock_alloc(net, sock, protocol);
3088 	if (!sk)
3089 		goto out;
3090 
3091 	/* create internal TCP socket for CLC handshake and fallback */
3092 	smc = smc_sk(sk);
3093 	smc->use_fallback = false; /* assume rdma capability first */
3094 	smc->fallback_rsn = 0;
3095 
3096 	/* default behavior from limit_smc_hs in every net namespace */
3097 	smc->limit_smc_hs = net->smc.limit_smc_hs;
3098 
3099 	rc = 0;
3100 	if (!clcsock) {
3101 		rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
3102 				      &smc->clcsock);
3103 		if (rc) {
3104 			sk_common_release(sk);
3105 			goto out;
3106 		}
3107 	} else {
3108 		smc->clcsock = clcsock;
3109 	}
3110 
3111 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
3112 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
3113 
3114 out:
3115 	return rc;
3116 }
3117 
3118 static int smc_create(struct net *net, struct socket *sock, int protocol,
3119 		      int kern)
3120 {
3121 	return __smc_create(net, sock, protocol, kern, NULL);
3122 }
3123 
3124 static const struct net_proto_family smc_sock_family_ops = {
3125 	.family	= PF_SMC,
3126 	.owner	= THIS_MODULE,
3127 	.create	= smc_create,
3128 };
3129 
3130 static int smc_ulp_init(struct sock *sk)
3131 {
3132 	struct socket *tcp = sk->sk_socket;
3133 	struct net *net = sock_net(sk);
3134 	struct socket *smcsock;
3135 	int protocol, ret;
3136 
3137 	/* only TCP can be replaced */
3138 	if (tcp->type != SOCK_STREAM || sk->sk_protocol != IPPROTO_TCP ||
3139 	    (sk->sk_family != AF_INET && sk->sk_family != AF_INET6))
3140 		return -ESOCKTNOSUPPORT;
3141 	/* don't handle wq now */
3142 	if (tcp->state != SS_UNCONNECTED || !tcp->file || tcp->wq.fasync_list)
3143 		return -ENOTCONN;
3144 
3145 	if (sk->sk_family == AF_INET)
3146 		protocol = SMCPROTO_SMC;
3147 	else
3148 		protocol = SMCPROTO_SMC6;
3149 
3150 	smcsock = sock_alloc();
3151 	if (!smcsock)
3152 		return -ENFILE;
3153 
3154 	smcsock->type = SOCK_STREAM;
3155 	__module_get(THIS_MODULE); /* tried in __tcp_ulp_find_autoload */
3156 	ret = __smc_create(net, smcsock, protocol, 1, tcp);
3157 	if (ret) {
3158 		sock_release(smcsock); /* module_put() which ops won't be NULL */
3159 		return ret;
3160 	}
3161 
3162 	/* replace tcp socket to smc */
3163 	smcsock->file = tcp->file;
3164 	smcsock->file->private_data = smcsock;
3165 	smcsock->file->f_inode = SOCK_INODE(smcsock); /* replace inode when sock_close */
3166 	smcsock->file->f_path.dentry->d_inode = SOCK_INODE(smcsock); /* dput() in __fput */
3167 	tcp->file = NULL;
3168 
3169 	return ret;
3170 }
3171 
3172 static void smc_ulp_clone(const struct request_sock *req, struct sock *newsk,
3173 			  const gfp_t priority)
3174 {
3175 	struct inet_connection_sock *icsk = inet_csk(newsk);
3176 
3177 	/* don't inherit ulp ops to child when listen */
3178 	icsk->icsk_ulp_ops = NULL;
3179 }
3180 
3181 static struct tcp_ulp_ops smc_ulp_ops __read_mostly = {
3182 	.name		= "smc",
3183 	.owner		= THIS_MODULE,
3184 	.init		= smc_ulp_init,
3185 	.clone		= smc_ulp_clone,
3186 };
3187 
3188 unsigned int smc_net_id;
3189 
3190 static __net_init int smc_net_init(struct net *net)
3191 {
3192 	int rc;
3193 
3194 	rc = smc_sysctl_net_init(net);
3195 	if (rc)
3196 		return rc;
3197 	return smc_pnet_net_init(net);
3198 }
3199 
3200 static void __net_exit smc_net_exit(struct net *net)
3201 {
3202 	smc_sysctl_net_exit(net);
3203 	smc_pnet_net_exit(net);
3204 }
3205 
3206 static __net_init int smc_net_stat_init(struct net *net)
3207 {
3208 	return smc_stats_init(net);
3209 }
3210 
3211 static void __net_exit smc_net_stat_exit(struct net *net)
3212 {
3213 	smc_stats_exit(net);
3214 }
3215 
3216 static struct pernet_operations smc_net_ops = {
3217 	.init = smc_net_init,
3218 	.exit = smc_net_exit,
3219 	.id   = &smc_net_id,
3220 	.size = sizeof(struct smc_net),
3221 };
3222 
3223 static struct pernet_operations smc_net_stat_ops = {
3224 	.init = smc_net_stat_init,
3225 	.exit = smc_net_stat_exit,
3226 };
3227 
3228 static int __init smc_init(void)
3229 {
3230 	int rc;
3231 
3232 	rc = register_pernet_subsys(&smc_net_ops);
3233 	if (rc)
3234 		return rc;
3235 
3236 	rc = register_pernet_subsys(&smc_net_stat_ops);
3237 	if (rc)
3238 		return rc;
3239 
3240 	smc_ism_init();
3241 	smc_clc_init();
3242 
3243 	rc = smc_nl_init();
3244 	if (rc)
3245 		goto out_pernet_subsys;
3246 
3247 	rc = smc_pnet_init();
3248 	if (rc)
3249 		goto out_nl;
3250 
3251 	rc = -ENOMEM;
3252 
3253 	smc_tcp_ls_wq = alloc_workqueue("smc_tcp_ls_wq", 0, 0);
3254 	if (!smc_tcp_ls_wq)
3255 		goto out_pnet;
3256 
3257 	smc_hs_wq = alloc_workqueue("smc_hs_wq", 0, 0);
3258 	if (!smc_hs_wq)
3259 		goto out_alloc_tcp_ls_wq;
3260 
3261 	smc_close_wq = alloc_workqueue("smc_close_wq", 0, 0);
3262 	if (!smc_close_wq)
3263 		goto out_alloc_hs_wq;
3264 
3265 	rc = smc_core_init();
3266 	if (rc) {
3267 		pr_err("%s: smc_core_init fails with %d\n", __func__, rc);
3268 		goto out_alloc_wqs;
3269 	}
3270 
3271 	rc = smc_llc_init();
3272 	if (rc) {
3273 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
3274 		goto out_core;
3275 	}
3276 
3277 	rc = smc_cdc_init();
3278 	if (rc) {
3279 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
3280 		goto out_core;
3281 	}
3282 
3283 	rc = proto_register(&smc_proto, 1);
3284 	if (rc) {
3285 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
3286 		goto out_core;
3287 	}
3288 
3289 	rc = proto_register(&smc_proto6, 1);
3290 	if (rc) {
3291 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
3292 		goto out_proto;
3293 	}
3294 
3295 	rc = sock_register(&smc_sock_family_ops);
3296 	if (rc) {
3297 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
3298 		goto out_proto6;
3299 	}
3300 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
3301 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
3302 
3303 	rc = smc_ib_register_client();
3304 	if (rc) {
3305 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
3306 		goto out_sock;
3307 	}
3308 
3309 	rc = tcp_register_ulp(&smc_ulp_ops);
3310 	if (rc) {
3311 		pr_err("%s: tcp_ulp_register fails with %d\n", __func__, rc);
3312 		goto out_ib;
3313 	}
3314 
3315 	static_branch_enable(&tcp_have_smc);
3316 	return 0;
3317 
3318 out_ib:
3319 	smc_ib_unregister_client();
3320 out_sock:
3321 	sock_unregister(PF_SMC);
3322 out_proto6:
3323 	proto_unregister(&smc_proto6);
3324 out_proto:
3325 	proto_unregister(&smc_proto);
3326 out_core:
3327 	smc_core_exit();
3328 out_alloc_wqs:
3329 	destroy_workqueue(smc_close_wq);
3330 out_alloc_hs_wq:
3331 	destroy_workqueue(smc_hs_wq);
3332 out_alloc_tcp_ls_wq:
3333 	destroy_workqueue(smc_tcp_ls_wq);
3334 out_pnet:
3335 	smc_pnet_exit();
3336 out_nl:
3337 	smc_nl_exit();
3338 out_pernet_subsys:
3339 	unregister_pernet_subsys(&smc_net_ops);
3340 
3341 	return rc;
3342 }
3343 
3344 static void __exit smc_exit(void)
3345 {
3346 	static_branch_disable(&tcp_have_smc);
3347 	tcp_unregister_ulp(&smc_ulp_ops);
3348 	sock_unregister(PF_SMC);
3349 	smc_core_exit();
3350 	smc_ib_unregister_client();
3351 	destroy_workqueue(smc_close_wq);
3352 	destroy_workqueue(smc_tcp_ls_wq);
3353 	destroy_workqueue(smc_hs_wq);
3354 	proto_unregister(&smc_proto6);
3355 	proto_unregister(&smc_proto);
3356 	smc_pnet_exit();
3357 	smc_nl_exit();
3358 	smc_clc_exit();
3359 	unregister_pernet_subsys(&smc_net_stat_ops);
3360 	unregister_pernet_subsys(&smc_net_ops);
3361 	rcu_barrier();
3362 }
3363 
3364 module_init(smc_init);
3365 module_exit(smc_exit);
3366 
3367 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
3368 MODULE_DESCRIPTION("smc socket address family");
3369 MODULE_LICENSE("GPL");
3370 MODULE_ALIAS_NETPROTO(PF_SMC);
3371 MODULE_ALIAS_TCP_ULP("smc");
3372