xref: /linux/net/smc/af_smc.c (revision 83869019c74cc2d01c96a3be2463a4eebe362224)
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 
55 static DEFINE_MUTEX(smc_server_lgr_pending);	/* serialize link group
56 						 * creation on server
57 						 */
58 static DEFINE_MUTEX(smc_client_lgr_pending);	/* serialize link group
59 						 * creation on client
60 						 */
61 
62 struct workqueue_struct	*smc_hs_wq;	/* wq for handshake work */
63 struct workqueue_struct	*smc_close_wq;	/* wq for close work */
64 
65 static void smc_tcp_listen_work(struct work_struct *);
66 static void smc_connect_work(struct work_struct *);
67 
68 static void smc_set_keepalive(struct sock *sk, int val)
69 {
70 	struct smc_sock *smc = smc_sk(sk);
71 
72 	smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
73 }
74 
75 static struct smc_hashinfo smc_v4_hashinfo = {
76 	.lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
77 };
78 
79 static struct smc_hashinfo smc_v6_hashinfo = {
80 	.lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
81 };
82 
83 int smc_hash_sk(struct sock *sk)
84 {
85 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
86 	struct hlist_head *head;
87 
88 	head = &h->ht;
89 
90 	write_lock_bh(&h->lock);
91 	sk_add_node(sk, head);
92 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
93 	write_unlock_bh(&h->lock);
94 
95 	return 0;
96 }
97 EXPORT_SYMBOL_GPL(smc_hash_sk);
98 
99 void smc_unhash_sk(struct sock *sk)
100 {
101 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
102 
103 	write_lock_bh(&h->lock);
104 	if (sk_del_node_init(sk))
105 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
106 	write_unlock_bh(&h->lock);
107 }
108 EXPORT_SYMBOL_GPL(smc_unhash_sk);
109 
110 struct proto smc_proto = {
111 	.name		= "SMC",
112 	.owner		= THIS_MODULE,
113 	.keepalive	= smc_set_keepalive,
114 	.hash		= smc_hash_sk,
115 	.unhash		= smc_unhash_sk,
116 	.obj_size	= sizeof(struct smc_sock),
117 	.h.smc_hash	= &smc_v4_hashinfo,
118 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
119 };
120 EXPORT_SYMBOL_GPL(smc_proto);
121 
122 struct proto smc_proto6 = {
123 	.name		= "SMC6",
124 	.owner		= THIS_MODULE,
125 	.keepalive	= smc_set_keepalive,
126 	.hash		= smc_hash_sk,
127 	.unhash		= smc_unhash_sk,
128 	.obj_size	= sizeof(struct smc_sock),
129 	.h.smc_hash	= &smc_v6_hashinfo,
130 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
131 };
132 EXPORT_SYMBOL_GPL(smc_proto6);
133 
134 static void smc_restore_fallback_changes(struct smc_sock *smc)
135 {
136 	if (smc->clcsock->file) { /* non-accepted sockets have no file yet */
137 		smc->clcsock->file->private_data = smc->sk.sk_socket;
138 		smc->clcsock->file = NULL;
139 	}
140 }
141 
142 static int __smc_release(struct smc_sock *smc)
143 {
144 	struct sock *sk = &smc->sk;
145 	int rc = 0;
146 
147 	if (!smc->use_fallback) {
148 		rc = smc_close_active(smc);
149 		sock_set_flag(sk, SOCK_DEAD);
150 		sk->sk_shutdown |= SHUTDOWN_MASK;
151 	} else {
152 		if (sk->sk_state != SMC_CLOSED) {
153 			if (sk->sk_state != SMC_LISTEN &&
154 			    sk->sk_state != SMC_INIT)
155 				sock_put(sk); /* passive closing */
156 			if (sk->sk_state == SMC_LISTEN) {
157 				/* wake up clcsock accept */
158 				rc = kernel_sock_shutdown(smc->clcsock,
159 							  SHUT_RDWR);
160 			}
161 			sk->sk_state = SMC_CLOSED;
162 			sk->sk_state_change(sk);
163 		}
164 		smc_restore_fallback_changes(smc);
165 	}
166 
167 	sk->sk_prot->unhash(sk);
168 
169 	if (sk->sk_state == SMC_CLOSED) {
170 		if (smc->clcsock) {
171 			release_sock(sk);
172 			smc_clcsock_release(smc);
173 			lock_sock(sk);
174 		}
175 		if (!smc->use_fallback)
176 			smc_conn_free(&smc->conn);
177 	}
178 
179 	return rc;
180 }
181 
182 static int smc_release(struct socket *sock)
183 {
184 	struct sock *sk = sock->sk;
185 	struct smc_sock *smc;
186 	int rc = 0;
187 
188 	if (!sk)
189 		goto out;
190 
191 	sock_hold(sk); /* sock_put below */
192 	smc = smc_sk(sk);
193 
194 	/* cleanup for a dangling non-blocking connect */
195 	if (smc->connect_nonblock && sk->sk_state == SMC_INIT)
196 		tcp_abort(smc->clcsock->sk, ECONNABORTED);
197 	flush_work(&smc->connect_work);
198 
199 	if (sk->sk_state == SMC_LISTEN)
200 		/* smc_close_non_accepted() is called and acquires
201 		 * sock lock for child sockets again
202 		 */
203 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
204 	else
205 		lock_sock(sk);
206 
207 	rc = __smc_release(smc);
208 
209 	/* detach socket */
210 	sock_orphan(sk);
211 	sock->sk = NULL;
212 	release_sock(sk);
213 
214 	sock_put(sk); /* sock_hold above */
215 	sock_put(sk); /* final sock_put */
216 out:
217 	return rc;
218 }
219 
220 static void smc_destruct(struct sock *sk)
221 {
222 	if (sk->sk_state != SMC_CLOSED)
223 		return;
224 	if (!sock_flag(sk, SOCK_DEAD))
225 		return;
226 
227 	sk_refcnt_debug_dec(sk);
228 }
229 
230 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
231 				   int protocol)
232 {
233 	struct smc_sock *smc;
234 	struct proto *prot;
235 	struct sock *sk;
236 
237 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
238 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
239 	if (!sk)
240 		return NULL;
241 
242 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
243 	sk->sk_state = SMC_INIT;
244 	sk->sk_destruct = smc_destruct;
245 	sk->sk_protocol = protocol;
246 	smc = smc_sk(sk);
247 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
248 	INIT_WORK(&smc->connect_work, smc_connect_work);
249 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
250 	INIT_LIST_HEAD(&smc->accept_q);
251 	spin_lock_init(&smc->accept_q_lock);
252 	spin_lock_init(&smc->conn.send_lock);
253 	sk->sk_prot->hash(sk);
254 	sk_refcnt_debug_inc(sk);
255 	mutex_init(&smc->clcsock_release_lock);
256 
257 	return sk;
258 }
259 
260 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
261 		    int addr_len)
262 {
263 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
264 	struct sock *sk = sock->sk;
265 	struct smc_sock *smc;
266 	int rc;
267 
268 	smc = smc_sk(sk);
269 
270 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
271 	rc = -EINVAL;
272 	if (addr_len < sizeof(struct sockaddr_in))
273 		goto out;
274 
275 	rc = -EAFNOSUPPORT;
276 	if (addr->sin_family != AF_INET &&
277 	    addr->sin_family != AF_INET6 &&
278 	    addr->sin_family != AF_UNSPEC)
279 		goto out;
280 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
281 	if (addr->sin_family == AF_UNSPEC &&
282 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
283 		goto out;
284 
285 	lock_sock(sk);
286 
287 	/* Check if socket is already active */
288 	rc = -EINVAL;
289 	if (sk->sk_state != SMC_INIT || smc->connect_nonblock)
290 		goto out_rel;
291 
292 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
293 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
294 
295 out_rel:
296 	release_sock(sk);
297 out:
298 	return rc;
299 }
300 
301 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
302 				   unsigned long mask)
303 {
304 	/* options we don't get control via setsockopt for */
305 	nsk->sk_type = osk->sk_type;
306 	nsk->sk_sndbuf = osk->sk_sndbuf;
307 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
308 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
309 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
310 	nsk->sk_mark = osk->sk_mark;
311 	nsk->sk_priority = osk->sk_priority;
312 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
313 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
314 	nsk->sk_err = osk->sk_err;
315 
316 	nsk->sk_flags &= ~mask;
317 	nsk->sk_flags |= osk->sk_flags & mask;
318 }
319 
320 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
321 			     (1UL << SOCK_KEEPOPEN) | \
322 			     (1UL << SOCK_LINGER) | \
323 			     (1UL << SOCK_BROADCAST) | \
324 			     (1UL << SOCK_TIMESTAMP) | \
325 			     (1UL << SOCK_DBG) | \
326 			     (1UL << SOCK_RCVTSTAMP) | \
327 			     (1UL << SOCK_RCVTSTAMPNS) | \
328 			     (1UL << SOCK_LOCALROUTE) | \
329 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
330 			     (1UL << SOCK_RXQ_OVFL) | \
331 			     (1UL << SOCK_WIFI_STATUS) | \
332 			     (1UL << SOCK_NOFCS) | \
333 			     (1UL << SOCK_FILTER_LOCKED) | \
334 			     (1UL << SOCK_TSTAMP_NEW))
335 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
336  * clc socket (since smc is not called for these options from net/core)
337  */
338 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
339 {
340 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
341 }
342 
343 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
344 			     (1UL << SOCK_KEEPOPEN) | \
345 			     (1UL << SOCK_LINGER) | \
346 			     (1UL << SOCK_DBG))
347 /* copy only settings and flags relevant for smc from clc to smc socket */
348 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
349 {
350 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
351 }
352 
353 /* register the new rmb on all links */
354 static int smcr_lgr_reg_rmbs(struct smc_link *link,
355 			     struct smc_buf_desc *rmb_desc)
356 {
357 	struct smc_link_group *lgr = link->lgr;
358 	int i, rc = 0;
359 
360 	rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
361 	if (rc)
362 		return rc;
363 	/* protect against parallel smc_llc_cli_rkey_exchange() and
364 	 * parallel smcr_link_reg_rmb()
365 	 */
366 	mutex_lock(&lgr->llc_conf_mutex);
367 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
368 		if (!smc_link_active(&lgr->lnk[i]))
369 			continue;
370 		rc = smcr_link_reg_rmb(&lgr->lnk[i], rmb_desc);
371 		if (rc)
372 			goto out;
373 	}
374 
375 	/* exchange confirm_rkey msg with peer */
376 	rc = smc_llc_do_confirm_rkey(link, rmb_desc);
377 	if (rc) {
378 		rc = -EFAULT;
379 		goto out;
380 	}
381 	rmb_desc->is_conf_rkey = true;
382 out:
383 	mutex_unlock(&lgr->llc_conf_mutex);
384 	smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
385 	return rc;
386 }
387 
388 static int smcr_clnt_conf_first_link(struct smc_sock *smc)
389 {
390 	struct smc_link *link = smc->conn.lnk;
391 	struct smc_llc_qentry *qentry;
392 	int rc;
393 
394 	/* receive CONFIRM LINK request from server over RoCE fabric */
395 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
396 			      SMC_LLC_CONFIRM_LINK);
397 	if (!qentry) {
398 		struct smc_clc_msg_decline dclc;
399 
400 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
401 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
402 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
403 	}
404 	smc_llc_save_peer_uid(qentry);
405 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_REQ);
406 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
407 	if (rc)
408 		return SMC_CLC_DECL_RMBE_EC;
409 
410 	rc = smc_ib_modify_qp_rts(link);
411 	if (rc)
412 		return SMC_CLC_DECL_ERR_RDYLNK;
413 
414 	smc_wr_remember_qp_attr(link);
415 
416 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc))
417 		return SMC_CLC_DECL_ERR_REGRMB;
418 
419 	/* confirm_rkey is implicit on 1st contact */
420 	smc->conn.rmb_desc->is_conf_rkey = true;
421 
422 	/* send CONFIRM LINK response over RoCE fabric */
423 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
424 	if (rc < 0)
425 		return SMC_CLC_DECL_TIMEOUT_CL;
426 
427 	smc_llc_link_active(link);
428 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
429 
430 	/* optional 2nd link, receive ADD LINK request from server */
431 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
432 			      SMC_LLC_ADD_LINK);
433 	if (!qentry) {
434 		struct smc_clc_msg_decline dclc;
435 
436 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
437 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
438 		if (rc == -EAGAIN)
439 			rc = 0; /* no DECLINE received, go with one link */
440 		return rc;
441 	}
442 	smc_llc_flow_qentry_clr(&link->lgr->llc_flow_lcl);
443 	smc_llc_cli_add_link(link, qentry);
444 	return 0;
445 }
446 
447 static bool smc_isascii(char *hostname)
448 {
449 	int i;
450 
451 	for (i = 0; i < SMC_MAX_HOSTNAME_LEN; i++)
452 		if (!isascii(hostname[i]))
453 			return false;
454 	return true;
455 }
456 
457 static void smc_conn_save_peer_info_fce(struct smc_sock *smc,
458 					struct smc_clc_msg_accept_confirm *clc)
459 {
460 	struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
461 		(struct smc_clc_msg_accept_confirm_v2 *)clc;
462 	struct smc_clc_first_contact_ext *fce;
463 	int clc_v2_len;
464 
465 	if (clc->hdr.version == SMC_V1 ||
466 	    !(clc->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
467 		return;
468 
469 	if (smc->conn.lgr->is_smcd) {
470 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->d1.eid,
471 		       SMC_MAX_EID_LEN);
472 		clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
473 					 d1);
474 	} else {
475 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->r1.eid,
476 		       SMC_MAX_EID_LEN);
477 		clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
478 					 r1);
479 	}
480 	fce = (struct smc_clc_first_contact_ext *)(((u8 *)clc_v2) + clc_v2_len);
481 	smc->conn.lgr->peer_os = fce->os_type;
482 	smc->conn.lgr->peer_smc_release = fce->release;
483 	if (smc_isascii(fce->hostname))
484 		memcpy(smc->conn.lgr->peer_hostname, fce->hostname,
485 		       SMC_MAX_HOSTNAME_LEN);
486 }
487 
488 static void smcr_conn_save_peer_info(struct smc_sock *smc,
489 				     struct smc_clc_msg_accept_confirm *clc)
490 {
491 	int bufsize = smc_uncompress_bufsize(clc->r0.rmbe_size);
492 
493 	smc->conn.peer_rmbe_idx = clc->r0.rmbe_idx;
494 	smc->conn.local_tx_ctrl.token = ntohl(clc->r0.rmbe_alert_token);
495 	smc->conn.peer_rmbe_size = bufsize;
496 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
497 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
498 }
499 
500 static void smcd_conn_save_peer_info(struct smc_sock *smc,
501 				     struct smc_clc_msg_accept_confirm *clc)
502 {
503 	int bufsize = smc_uncompress_bufsize(clc->d0.dmbe_size);
504 
505 	smc->conn.peer_rmbe_idx = clc->d0.dmbe_idx;
506 	smc->conn.peer_token = clc->d0.token;
507 	/* msg header takes up space in the buffer */
508 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
509 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
510 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
511 }
512 
513 static void smc_conn_save_peer_info(struct smc_sock *smc,
514 				    struct smc_clc_msg_accept_confirm *clc)
515 {
516 	if (smc->conn.lgr->is_smcd)
517 		smcd_conn_save_peer_info(smc, clc);
518 	else
519 		smcr_conn_save_peer_info(smc, clc);
520 	smc_conn_save_peer_info_fce(smc, clc);
521 }
522 
523 static void smc_link_save_peer_info(struct smc_link *link,
524 				    struct smc_clc_msg_accept_confirm *clc,
525 				    struct smc_init_info *ini)
526 {
527 	link->peer_qpn = ntoh24(clc->r0.qpn);
528 	memcpy(link->peer_gid, ini->peer_gid, SMC_GID_SIZE);
529 	memcpy(link->peer_mac, ini->peer_mac, sizeof(link->peer_mac));
530 	link->peer_psn = ntoh24(clc->r0.psn);
531 	link->peer_mtu = clc->r0.qp_mtu;
532 }
533 
534 static void smc_stat_inc_fback_rsn_cnt(struct smc_sock *smc,
535 				       struct smc_stats_fback *fback_arr)
536 {
537 	int cnt;
538 
539 	for (cnt = 0; cnt < SMC_MAX_FBACK_RSN_CNT; cnt++) {
540 		if (fback_arr[cnt].fback_code == smc->fallback_rsn) {
541 			fback_arr[cnt].count++;
542 			break;
543 		}
544 		if (!fback_arr[cnt].fback_code) {
545 			fback_arr[cnt].fback_code = smc->fallback_rsn;
546 			fback_arr[cnt].count++;
547 			break;
548 		}
549 	}
550 }
551 
552 static void smc_stat_fallback(struct smc_sock *smc)
553 {
554 	struct net *net = sock_net(&smc->sk);
555 
556 	mutex_lock(&net->smc.mutex_fback_rsn);
557 	if (smc->listen_smc) {
558 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->srv);
559 		net->smc.fback_rsn->srv_fback_cnt++;
560 	} else {
561 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->clnt);
562 		net->smc.fback_rsn->clnt_fback_cnt++;
563 	}
564 	mutex_unlock(&net->smc.mutex_fback_rsn);
565 }
566 
567 static void smc_switch_to_fallback(struct smc_sock *smc, int reason_code)
568 {
569 	wait_queue_head_t *smc_wait = sk_sleep(&smc->sk);
570 	wait_queue_head_t *clc_wait = sk_sleep(smc->clcsock->sk);
571 	unsigned long flags;
572 
573 	smc->use_fallback = true;
574 	smc->fallback_rsn = reason_code;
575 	smc_stat_fallback(smc);
576 	trace_smc_switch_to_fallback(smc, reason_code);
577 	if (smc->sk.sk_socket && smc->sk.sk_socket->file) {
578 		smc->clcsock->file = smc->sk.sk_socket->file;
579 		smc->clcsock->file->private_data = smc->clcsock;
580 		smc->clcsock->wq.fasync_list =
581 			smc->sk.sk_socket->wq.fasync_list;
582 
583 		/* There may be some entries remaining in
584 		 * smc socket->wq, which should be removed
585 		 * to clcsocket->wq during the fallback.
586 		 */
587 		spin_lock_irqsave(&smc_wait->lock, flags);
588 		spin_lock_nested(&clc_wait->lock, SINGLE_DEPTH_NESTING);
589 		list_splice_init(&smc_wait->head, &clc_wait->head);
590 		spin_unlock(&clc_wait->lock);
591 		spin_unlock_irqrestore(&smc_wait->lock, flags);
592 	}
593 }
594 
595 /* fall back during connect */
596 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
597 {
598 	smc_switch_to_fallback(smc, reason_code);
599 	smc_copy_sock_settings_to_clc(smc);
600 	smc->connect_nonblock = 0;
601 	if (smc->sk.sk_state == SMC_INIT)
602 		smc->sk.sk_state = SMC_ACTIVE;
603 	return 0;
604 }
605 
606 /* decline and fall back during connect */
607 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code,
608 					u8 version)
609 {
610 	struct net *net = sock_net(&smc->sk);
611 	int rc;
612 
613 	if (reason_code < 0) { /* error, fallback is not possible */
614 		this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
615 		if (smc->sk.sk_state == SMC_INIT)
616 			sock_put(&smc->sk); /* passive closing */
617 		return reason_code;
618 	}
619 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
620 		rc = smc_clc_send_decline(smc, reason_code, version);
621 		if (rc < 0) {
622 			this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
623 			if (smc->sk.sk_state == SMC_INIT)
624 				sock_put(&smc->sk); /* passive closing */
625 			return rc;
626 		}
627 	}
628 	return smc_connect_fallback(smc, reason_code);
629 }
630 
631 static void smc_conn_abort(struct smc_sock *smc, int local_first)
632 {
633 	if (local_first)
634 		smc_lgr_cleanup_early(&smc->conn);
635 	else
636 		smc_conn_free(&smc->conn);
637 }
638 
639 /* check if there is a rdma device available for this connection. */
640 /* called for connect and listen */
641 static int smc_find_rdma_device(struct smc_sock *smc, struct smc_init_info *ini)
642 {
643 	/* PNET table look up: search active ib_device and port
644 	 * within same PNETID that also contains the ethernet device
645 	 * used for the internal TCP socket
646 	 */
647 	smc_pnet_find_roce_resource(smc->clcsock->sk, ini);
648 	if (!ini->check_smcrv2 && !ini->ib_dev)
649 		return SMC_CLC_DECL_NOSMCRDEV;
650 	if (ini->check_smcrv2 && !ini->smcrv2.ib_dev_v2)
651 		return SMC_CLC_DECL_NOSMCRDEV;
652 	return 0;
653 }
654 
655 /* check if there is an ISM device available for this connection. */
656 /* called for connect and listen */
657 static int smc_find_ism_device(struct smc_sock *smc, struct smc_init_info *ini)
658 {
659 	/* Find ISM device with same PNETID as connecting interface  */
660 	smc_pnet_find_ism_resource(smc->clcsock->sk, ini);
661 	if (!ini->ism_dev[0])
662 		return SMC_CLC_DECL_NOSMCDDEV;
663 	else
664 		ini->ism_chid[0] = smc_ism_get_chid(ini->ism_dev[0]);
665 	return 0;
666 }
667 
668 /* is chid unique for the ism devices that are already determined? */
669 static bool smc_find_ism_v2_is_unique_chid(u16 chid, struct smc_init_info *ini,
670 					   int cnt)
671 {
672 	int i = (!ini->ism_dev[0]) ? 1 : 0;
673 
674 	for (; i < cnt; i++)
675 		if (ini->ism_chid[i] == chid)
676 			return false;
677 	return true;
678 }
679 
680 /* determine possible V2 ISM devices (either without PNETID or with PNETID plus
681  * PNETID matching net_device)
682  */
683 static int smc_find_ism_v2_device_clnt(struct smc_sock *smc,
684 				       struct smc_init_info *ini)
685 {
686 	int rc = SMC_CLC_DECL_NOSMCDDEV;
687 	struct smcd_dev *smcd;
688 	int i = 1;
689 	u16 chid;
690 
691 	if (smcd_indicated(ini->smc_type_v1))
692 		rc = 0;		/* already initialized for V1 */
693 	mutex_lock(&smcd_dev_list.mutex);
694 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
695 		if (smcd->going_away || smcd == ini->ism_dev[0])
696 			continue;
697 		chid = smc_ism_get_chid(smcd);
698 		if (!smc_find_ism_v2_is_unique_chid(chid, ini, i))
699 			continue;
700 		if (!smc_pnet_is_pnetid_set(smcd->pnetid) ||
701 		    smc_pnet_is_ndev_pnetid(sock_net(&smc->sk), smcd->pnetid)) {
702 			ini->ism_dev[i] = smcd;
703 			ini->ism_chid[i] = chid;
704 			ini->is_smcd = true;
705 			rc = 0;
706 			i++;
707 			if (i > SMC_MAX_ISM_DEVS)
708 				break;
709 		}
710 	}
711 	mutex_unlock(&smcd_dev_list.mutex);
712 	ini->ism_offered_cnt = i - 1;
713 	if (!ini->ism_dev[0] && !ini->ism_dev[1])
714 		ini->smcd_version = 0;
715 
716 	return rc;
717 }
718 
719 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
720 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
721 				      struct smc_init_info *ini)
722 {
723 	if (ini->vlan_id && smc_ism_get_vlan(ini->ism_dev[0], ini->vlan_id))
724 		return SMC_CLC_DECL_ISMVLANERR;
725 	return 0;
726 }
727 
728 static int smc_find_proposal_devices(struct smc_sock *smc,
729 				     struct smc_init_info *ini)
730 {
731 	int rc = 0;
732 
733 	/* check if there is an ism device available */
734 	if (!(ini->smcd_version & SMC_V1) ||
735 	    smc_find_ism_device(smc, ini) ||
736 	    smc_connect_ism_vlan_setup(smc, ini))
737 		ini->smcd_version &= ~SMC_V1;
738 	/* else ISM V1 is supported for this connection */
739 
740 	/* check if there is an rdma device available */
741 	if (!(ini->smcr_version & SMC_V1) ||
742 	    smc_find_rdma_device(smc, ini))
743 		ini->smcr_version &= ~SMC_V1;
744 	/* else RDMA is supported for this connection */
745 
746 	ini->smc_type_v1 = smc_indicated_type(ini->smcd_version & SMC_V1,
747 					      ini->smcr_version & SMC_V1);
748 
749 	/* check if there is an ism v2 device available */
750 	if (!(ini->smcd_version & SMC_V2) ||
751 	    !smc_ism_is_v2_capable() ||
752 	    smc_find_ism_v2_device_clnt(smc, ini))
753 		ini->smcd_version &= ~SMC_V2;
754 
755 	/* check if there is an rdma v2 device available */
756 	ini->check_smcrv2 = true;
757 	ini->smcrv2.saddr = smc->clcsock->sk->sk_rcv_saddr;
758 	if (!(ini->smcr_version & SMC_V2) ||
759 	    smc->clcsock->sk->sk_family != AF_INET ||
760 	    !smc_clc_ueid_count() ||
761 	    smc_find_rdma_device(smc, ini))
762 		ini->smcr_version &= ~SMC_V2;
763 	ini->check_smcrv2 = false;
764 
765 	ini->smc_type_v2 = smc_indicated_type(ini->smcd_version & SMC_V2,
766 					      ini->smcr_version & SMC_V2);
767 
768 	/* if neither ISM nor RDMA are supported, fallback */
769 	if (ini->smc_type_v1 == SMC_TYPE_N && ini->smc_type_v2 == SMC_TYPE_N)
770 		rc = SMC_CLC_DECL_NOSMCDEV;
771 
772 	return rc;
773 }
774 
775 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
776  * used, the VLAN ID will be registered again during the connection setup.
777  */
778 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc,
779 					struct smc_init_info *ini)
780 {
781 	if (!smcd_indicated(ini->smc_type_v1))
782 		return 0;
783 	if (ini->vlan_id && smc_ism_put_vlan(ini->ism_dev[0], ini->vlan_id))
784 		return SMC_CLC_DECL_CNFERR;
785 	return 0;
786 }
787 
788 #define SMC_CLC_MAX_ACCEPT_LEN \
789 	(sizeof(struct smc_clc_msg_accept_confirm_v2) + \
790 	 sizeof(struct smc_clc_first_contact_ext) + \
791 	 sizeof(struct smc_clc_msg_trail))
792 
793 /* CLC handshake during connect */
794 static int smc_connect_clc(struct smc_sock *smc,
795 			   struct smc_clc_msg_accept_confirm_v2 *aclc2,
796 			   struct smc_init_info *ini)
797 {
798 	int rc = 0;
799 
800 	/* do inband token exchange */
801 	rc = smc_clc_send_proposal(smc, ini);
802 	if (rc)
803 		return rc;
804 	/* receive SMC Accept CLC message */
805 	return smc_clc_wait_msg(smc, aclc2, SMC_CLC_MAX_ACCEPT_LEN,
806 				SMC_CLC_ACCEPT, CLC_WAIT_TIME);
807 }
808 
809 void smc_fill_gid_list(struct smc_link_group *lgr,
810 		       struct smc_gidlist *gidlist,
811 		       struct smc_ib_device *known_dev, u8 *known_gid)
812 {
813 	struct smc_init_info *alt_ini = NULL;
814 
815 	memset(gidlist, 0, sizeof(*gidlist));
816 	memcpy(gidlist->list[gidlist->len++], known_gid, SMC_GID_SIZE);
817 
818 	alt_ini = kzalloc(sizeof(*alt_ini), GFP_KERNEL);
819 	if (!alt_ini)
820 		goto out;
821 
822 	alt_ini->vlan_id = lgr->vlan_id;
823 	alt_ini->check_smcrv2 = true;
824 	alt_ini->smcrv2.saddr = lgr->saddr;
825 	smc_pnet_find_alt_roce(lgr, alt_ini, known_dev);
826 
827 	if (!alt_ini->smcrv2.ib_dev_v2)
828 		goto out;
829 
830 	memcpy(gidlist->list[gidlist->len++], alt_ini->smcrv2.ib_gid_v2,
831 	       SMC_GID_SIZE);
832 
833 out:
834 	kfree(alt_ini);
835 }
836 
837 static int smc_connect_rdma_v2_prepare(struct smc_sock *smc,
838 				       struct smc_clc_msg_accept_confirm *aclc,
839 				       struct smc_init_info *ini)
840 {
841 	struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
842 		(struct smc_clc_msg_accept_confirm_v2 *)aclc;
843 	struct smc_clc_first_contact_ext *fce =
844 		(struct smc_clc_first_contact_ext *)
845 			(((u8 *)clc_v2) + sizeof(*clc_v2));
846 
847 	if (!ini->first_contact_peer || aclc->hdr.version == SMC_V1)
848 		return 0;
849 
850 	if (fce->v2_direct) {
851 		memcpy(ini->smcrv2.nexthop_mac, &aclc->r0.lcl.mac, ETH_ALEN);
852 		ini->smcrv2.uses_gateway = false;
853 	} else {
854 		if (smc_ib_find_route(smc->clcsock->sk->sk_rcv_saddr,
855 				      smc_ib_gid_to_ipv4(aclc->r0.lcl.gid),
856 				      ini->smcrv2.nexthop_mac,
857 				      &ini->smcrv2.uses_gateway))
858 			return SMC_CLC_DECL_NOROUTE;
859 		if (!ini->smcrv2.uses_gateway) {
860 			/* mismatch: peer claims indirect, but its direct */
861 			return SMC_CLC_DECL_NOINDIRECT;
862 		}
863 	}
864 	return 0;
865 }
866 
867 /* setup for RDMA connection of client */
868 static int smc_connect_rdma(struct smc_sock *smc,
869 			    struct smc_clc_msg_accept_confirm *aclc,
870 			    struct smc_init_info *ini)
871 {
872 	int i, reason_code = 0;
873 	struct smc_link *link;
874 	u8 *eid = NULL;
875 
876 	ini->is_smcd = false;
877 	ini->ib_clcqpn = ntoh24(aclc->r0.qpn);
878 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
879 	memcpy(ini->peer_systemid, aclc->r0.lcl.id_for_peer, SMC_SYSTEMID_LEN);
880 	memcpy(ini->peer_gid, aclc->r0.lcl.gid, SMC_GID_SIZE);
881 	memcpy(ini->peer_mac, aclc->r0.lcl.mac, ETH_ALEN);
882 
883 	reason_code = smc_connect_rdma_v2_prepare(smc, aclc, ini);
884 	if (reason_code)
885 		return reason_code;
886 
887 	mutex_lock(&smc_client_lgr_pending);
888 	reason_code = smc_conn_create(smc, ini);
889 	if (reason_code) {
890 		mutex_unlock(&smc_client_lgr_pending);
891 		return reason_code;
892 	}
893 
894 	smc_conn_save_peer_info(smc, aclc);
895 
896 	if (ini->first_contact_local) {
897 		link = smc->conn.lnk;
898 	} else {
899 		/* set link that was assigned by server */
900 		link = NULL;
901 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
902 			struct smc_link *l = &smc->conn.lgr->lnk[i];
903 
904 			if (l->peer_qpn == ntoh24(aclc->r0.qpn) &&
905 			    !memcmp(l->peer_gid, &aclc->r0.lcl.gid,
906 				    SMC_GID_SIZE) &&
907 			    (aclc->hdr.version > SMC_V1 ||
908 			     !memcmp(l->peer_mac, &aclc->r0.lcl.mac,
909 				     sizeof(l->peer_mac)))) {
910 				link = l;
911 				break;
912 			}
913 		}
914 		if (!link) {
915 			reason_code = SMC_CLC_DECL_NOSRVLINK;
916 			goto connect_abort;
917 		}
918 		smc_switch_link_and_count(&smc->conn, link);
919 	}
920 
921 	/* create send buffer and rmb */
922 	if (smc_buf_create(smc, false)) {
923 		reason_code = SMC_CLC_DECL_MEM;
924 		goto connect_abort;
925 	}
926 
927 	if (ini->first_contact_local)
928 		smc_link_save_peer_info(link, aclc, ini);
929 
930 	if (smc_rmb_rtoken_handling(&smc->conn, link, aclc)) {
931 		reason_code = SMC_CLC_DECL_ERR_RTOK;
932 		goto connect_abort;
933 	}
934 
935 	smc_close_init(smc);
936 	smc_rx_init(smc);
937 
938 	if (ini->first_contact_local) {
939 		if (smc_ib_ready_link(link)) {
940 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
941 			goto connect_abort;
942 		}
943 	} else {
944 		if (smcr_lgr_reg_rmbs(link, smc->conn.rmb_desc)) {
945 			reason_code = SMC_CLC_DECL_ERR_REGRMB;
946 			goto connect_abort;
947 		}
948 	}
949 	smc_rmb_sync_sg_for_device(&smc->conn);
950 
951 	if (aclc->hdr.version > SMC_V1) {
952 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
953 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
954 
955 		eid = clc_v2->r1.eid;
956 		if (ini->first_contact_local)
957 			smc_fill_gid_list(link->lgr, &ini->smcrv2.gidlist,
958 					  link->smcibdev, link->gid);
959 	}
960 
961 	reason_code = smc_clc_send_confirm(smc, ini->first_contact_local,
962 					   aclc->hdr.version, eid, ini);
963 	if (reason_code)
964 		goto connect_abort;
965 
966 	smc_tx_init(smc);
967 
968 	if (ini->first_contact_local) {
969 		/* QP confirmation over RoCE fabric */
970 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
971 		reason_code = smcr_clnt_conf_first_link(smc);
972 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
973 		if (reason_code)
974 			goto connect_abort;
975 	}
976 	mutex_unlock(&smc_client_lgr_pending);
977 
978 	smc_copy_sock_settings_to_clc(smc);
979 	smc->connect_nonblock = 0;
980 	if (smc->sk.sk_state == SMC_INIT)
981 		smc->sk.sk_state = SMC_ACTIVE;
982 
983 	return 0;
984 connect_abort:
985 	smc_conn_abort(smc, ini->first_contact_local);
986 	mutex_unlock(&smc_client_lgr_pending);
987 	smc->connect_nonblock = 0;
988 
989 	return reason_code;
990 }
991 
992 /* The server has chosen one of the proposed ISM devices for the communication.
993  * Determine from the CHID of the received CLC ACCEPT the ISM device chosen.
994  */
995 static int
996 smc_v2_determine_accepted_chid(struct smc_clc_msg_accept_confirm_v2 *aclc,
997 			       struct smc_init_info *ini)
998 {
999 	int i;
1000 
1001 	for (i = 0; i < ini->ism_offered_cnt + 1; i++) {
1002 		if (ini->ism_chid[i] == ntohs(aclc->d1.chid)) {
1003 			ini->ism_selected = i;
1004 			return 0;
1005 		}
1006 	}
1007 
1008 	return -EPROTO;
1009 }
1010 
1011 /* setup for ISM connection of client */
1012 static int smc_connect_ism(struct smc_sock *smc,
1013 			   struct smc_clc_msg_accept_confirm *aclc,
1014 			   struct smc_init_info *ini)
1015 {
1016 	u8 *eid = NULL;
1017 	int rc = 0;
1018 
1019 	ini->is_smcd = true;
1020 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
1021 
1022 	if (aclc->hdr.version == SMC_V2) {
1023 		struct smc_clc_msg_accept_confirm_v2 *aclc_v2 =
1024 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1025 
1026 		rc = smc_v2_determine_accepted_chid(aclc_v2, ini);
1027 		if (rc)
1028 			return rc;
1029 	}
1030 	ini->ism_peer_gid[ini->ism_selected] = aclc->d0.gid;
1031 
1032 	/* there is only one lgr role for SMC-D; use server lock */
1033 	mutex_lock(&smc_server_lgr_pending);
1034 	rc = smc_conn_create(smc, ini);
1035 	if (rc) {
1036 		mutex_unlock(&smc_server_lgr_pending);
1037 		return rc;
1038 	}
1039 
1040 	/* Create send and receive buffers */
1041 	rc = smc_buf_create(smc, true);
1042 	if (rc) {
1043 		rc = (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB : SMC_CLC_DECL_MEM;
1044 		goto connect_abort;
1045 	}
1046 
1047 	smc_conn_save_peer_info(smc, aclc);
1048 	smc_close_init(smc);
1049 	smc_rx_init(smc);
1050 	smc_tx_init(smc);
1051 
1052 	if (aclc->hdr.version > SMC_V1) {
1053 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
1054 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1055 
1056 		eid = clc_v2->d1.eid;
1057 	}
1058 
1059 	rc = smc_clc_send_confirm(smc, ini->first_contact_local,
1060 				  aclc->hdr.version, eid, NULL);
1061 	if (rc)
1062 		goto connect_abort;
1063 	mutex_unlock(&smc_server_lgr_pending);
1064 
1065 	smc_copy_sock_settings_to_clc(smc);
1066 	smc->connect_nonblock = 0;
1067 	if (smc->sk.sk_state == SMC_INIT)
1068 		smc->sk.sk_state = SMC_ACTIVE;
1069 
1070 	return 0;
1071 connect_abort:
1072 	smc_conn_abort(smc, ini->first_contact_local);
1073 	mutex_unlock(&smc_server_lgr_pending);
1074 	smc->connect_nonblock = 0;
1075 
1076 	return rc;
1077 }
1078 
1079 /* check if received accept type and version matches a proposed one */
1080 static int smc_connect_check_aclc(struct smc_init_info *ini,
1081 				  struct smc_clc_msg_accept_confirm *aclc)
1082 {
1083 	if (aclc->hdr.typev1 != SMC_TYPE_R &&
1084 	    aclc->hdr.typev1 != SMC_TYPE_D)
1085 		return SMC_CLC_DECL_MODEUNSUPP;
1086 
1087 	if (aclc->hdr.version >= SMC_V2) {
1088 		if ((aclc->hdr.typev1 == SMC_TYPE_R &&
1089 		     !smcr_indicated(ini->smc_type_v2)) ||
1090 		    (aclc->hdr.typev1 == SMC_TYPE_D &&
1091 		     !smcd_indicated(ini->smc_type_v2)))
1092 			return SMC_CLC_DECL_MODEUNSUPP;
1093 	} else {
1094 		if ((aclc->hdr.typev1 == SMC_TYPE_R &&
1095 		     !smcr_indicated(ini->smc_type_v1)) ||
1096 		    (aclc->hdr.typev1 == SMC_TYPE_D &&
1097 		     !smcd_indicated(ini->smc_type_v1)))
1098 			return SMC_CLC_DECL_MODEUNSUPP;
1099 	}
1100 
1101 	return 0;
1102 }
1103 
1104 /* perform steps before actually connecting */
1105 static int __smc_connect(struct smc_sock *smc)
1106 {
1107 	u8 version = smc_ism_is_v2_capable() ? SMC_V2 : SMC_V1;
1108 	struct smc_clc_msg_accept_confirm_v2 *aclc2;
1109 	struct smc_clc_msg_accept_confirm *aclc;
1110 	struct smc_init_info *ini = NULL;
1111 	u8 *buf = NULL;
1112 	int rc = 0;
1113 
1114 	if (smc->use_fallback)
1115 		return smc_connect_fallback(smc, smc->fallback_rsn);
1116 
1117 	/* if peer has not signalled SMC-capability, fall back */
1118 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
1119 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
1120 
1121 	/* IPSec connections opt out of SMC optimizations */
1122 	if (using_ipsec(smc))
1123 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC,
1124 						    version);
1125 
1126 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1127 	if (!ini)
1128 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_MEM,
1129 						    version);
1130 
1131 	ini->smcd_version = SMC_V1 | SMC_V2;
1132 	ini->smcr_version = SMC_V1 | SMC_V2;
1133 	ini->smc_type_v1 = SMC_TYPE_B;
1134 	ini->smc_type_v2 = SMC_TYPE_B;
1135 
1136 	/* get vlan id from IP device */
1137 	if (smc_vlan_by_tcpsk(smc->clcsock, ini)) {
1138 		ini->smcd_version &= ~SMC_V1;
1139 		ini->smcr_version = 0;
1140 		ini->smc_type_v1 = SMC_TYPE_N;
1141 		if (!ini->smcd_version) {
1142 			rc = SMC_CLC_DECL_GETVLANERR;
1143 			goto fallback;
1144 		}
1145 	}
1146 
1147 	rc = smc_find_proposal_devices(smc, ini);
1148 	if (rc)
1149 		goto fallback;
1150 
1151 	buf = kzalloc(SMC_CLC_MAX_ACCEPT_LEN, GFP_KERNEL);
1152 	if (!buf) {
1153 		rc = SMC_CLC_DECL_MEM;
1154 		goto fallback;
1155 	}
1156 	aclc2 = (struct smc_clc_msg_accept_confirm_v2 *)buf;
1157 	aclc = (struct smc_clc_msg_accept_confirm *)aclc2;
1158 
1159 	/* perform CLC handshake */
1160 	rc = smc_connect_clc(smc, aclc2, ini);
1161 	if (rc)
1162 		goto vlan_cleanup;
1163 
1164 	/* check if smc modes and versions of CLC proposal and accept match */
1165 	rc = smc_connect_check_aclc(ini, aclc);
1166 	version = aclc->hdr.version == SMC_V1 ? SMC_V1 : SMC_V2;
1167 	if (rc)
1168 		goto vlan_cleanup;
1169 
1170 	/* depending on previous steps, connect using rdma or ism */
1171 	if (aclc->hdr.typev1 == SMC_TYPE_R) {
1172 		ini->smcr_version = version;
1173 		rc = smc_connect_rdma(smc, aclc, ini);
1174 	} else if (aclc->hdr.typev1 == SMC_TYPE_D) {
1175 		ini->smcd_version = version;
1176 		rc = smc_connect_ism(smc, aclc, ini);
1177 	}
1178 	if (rc)
1179 		goto vlan_cleanup;
1180 
1181 	SMC_STAT_CLNT_SUCC_INC(sock_net(smc->clcsock->sk), aclc);
1182 	smc_connect_ism_vlan_cleanup(smc, ini);
1183 	kfree(buf);
1184 	kfree(ini);
1185 	return 0;
1186 
1187 vlan_cleanup:
1188 	smc_connect_ism_vlan_cleanup(smc, ini);
1189 	kfree(buf);
1190 fallback:
1191 	kfree(ini);
1192 	return smc_connect_decline_fallback(smc, rc, version);
1193 }
1194 
1195 static void smc_connect_work(struct work_struct *work)
1196 {
1197 	struct smc_sock *smc = container_of(work, struct smc_sock,
1198 					    connect_work);
1199 	long timeo = smc->sk.sk_sndtimeo;
1200 	int rc = 0;
1201 
1202 	if (!timeo)
1203 		timeo = MAX_SCHEDULE_TIMEOUT;
1204 	lock_sock(smc->clcsock->sk);
1205 	if (smc->clcsock->sk->sk_err) {
1206 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
1207 	} else if ((1 << smc->clcsock->sk->sk_state) &
1208 					(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
1209 		rc = sk_stream_wait_connect(smc->clcsock->sk, &timeo);
1210 		if ((rc == -EPIPE) &&
1211 		    ((1 << smc->clcsock->sk->sk_state) &
1212 					(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))
1213 			rc = 0;
1214 	}
1215 	release_sock(smc->clcsock->sk);
1216 	lock_sock(&smc->sk);
1217 	if (rc != 0 || smc->sk.sk_err) {
1218 		smc->sk.sk_state = SMC_CLOSED;
1219 		if (rc == -EPIPE || rc == -EAGAIN)
1220 			smc->sk.sk_err = EPIPE;
1221 		else if (signal_pending(current))
1222 			smc->sk.sk_err = -sock_intr_errno(timeo);
1223 		sock_put(&smc->sk); /* passive closing */
1224 		goto out;
1225 	}
1226 
1227 	rc = __smc_connect(smc);
1228 	if (rc < 0)
1229 		smc->sk.sk_err = -rc;
1230 
1231 out:
1232 	if (!sock_flag(&smc->sk, SOCK_DEAD)) {
1233 		if (smc->sk.sk_err) {
1234 			smc->sk.sk_state_change(&smc->sk);
1235 		} else { /* allow polling before and after fallback decision */
1236 			smc->clcsock->sk->sk_write_space(smc->clcsock->sk);
1237 			smc->sk.sk_write_space(&smc->sk);
1238 		}
1239 	}
1240 	release_sock(&smc->sk);
1241 }
1242 
1243 static int smc_connect(struct socket *sock, struct sockaddr *addr,
1244 		       int alen, int flags)
1245 {
1246 	struct sock *sk = sock->sk;
1247 	struct smc_sock *smc;
1248 	int rc = -EINVAL;
1249 
1250 	smc = smc_sk(sk);
1251 
1252 	/* separate smc parameter checking to be safe */
1253 	if (alen < sizeof(addr->sa_family))
1254 		goto out_err;
1255 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
1256 		goto out_err;
1257 
1258 	lock_sock(sk);
1259 	switch (sk->sk_state) {
1260 	default:
1261 		goto out;
1262 	case SMC_ACTIVE:
1263 		rc = -EISCONN;
1264 		goto out;
1265 	case SMC_INIT:
1266 		break;
1267 	}
1268 
1269 	smc_copy_sock_settings_to_clc(smc);
1270 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1271 	if (smc->connect_nonblock) {
1272 		rc = -EALREADY;
1273 		goto out;
1274 	}
1275 	rc = kernel_connect(smc->clcsock, addr, alen, flags);
1276 	if (rc && rc != -EINPROGRESS)
1277 		goto out;
1278 
1279 	sock_hold(&smc->sk); /* sock put in passive closing */
1280 	if (smc->use_fallback)
1281 		goto out;
1282 	if (flags & O_NONBLOCK) {
1283 		if (queue_work(smc_hs_wq, &smc->connect_work))
1284 			smc->connect_nonblock = 1;
1285 		rc = -EINPROGRESS;
1286 	} else {
1287 		rc = __smc_connect(smc);
1288 		if (rc < 0)
1289 			goto out;
1290 		else
1291 			rc = 0; /* success cases including fallback */
1292 	}
1293 
1294 out:
1295 	release_sock(sk);
1296 out_err:
1297 	return rc;
1298 }
1299 
1300 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
1301 {
1302 	struct socket *new_clcsock = NULL;
1303 	struct sock *lsk = &lsmc->sk;
1304 	struct sock *new_sk;
1305 	int rc = -EINVAL;
1306 
1307 	release_sock(lsk);
1308 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
1309 	if (!new_sk) {
1310 		rc = -ENOMEM;
1311 		lsk->sk_err = ENOMEM;
1312 		*new_smc = NULL;
1313 		lock_sock(lsk);
1314 		goto out;
1315 	}
1316 	*new_smc = smc_sk(new_sk);
1317 
1318 	mutex_lock(&lsmc->clcsock_release_lock);
1319 	if (lsmc->clcsock)
1320 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, SOCK_NONBLOCK);
1321 	mutex_unlock(&lsmc->clcsock_release_lock);
1322 	lock_sock(lsk);
1323 	if  (rc < 0 && rc != -EAGAIN)
1324 		lsk->sk_err = -rc;
1325 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
1326 		new_sk->sk_prot->unhash(new_sk);
1327 		if (new_clcsock)
1328 			sock_release(new_clcsock);
1329 		new_sk->sk_state = SMC_CLOSED;
1330 		sock_set_flag(new_sk, SOCK_DEAD);
1331 		sock_put(new_sk); /* final */
1332 		*new_smc = NULL;
1333 		goto out;
1334 	}
1335 
1336 	/* new clcsock has inherited the smc listen-specific sk_data_ready
1337 	 * function; switch it back to the original sk_data_ready function
1338 	 */
1339 	new_clcsock->sk->sk_data_ready = lsmc->clcsk_data_ready;
1340 	(*new_smc)->clcsock = new_clcsock;
1341 out:
1342 	return rc;
1343 }
1344 
1345 /* add a just created sock to the accept queue of the listen sock as
1346  * candidate for a following socket accept call from user space
1347  */
1348 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
1349 {
1350 	struct smc_sock *par = smc_sk(parent);
1351 
1352 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
1353 	spin_lock(&par->accept_q_lock);
1354 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
1355 	spin_unlock(&par->accept_q_lock);
1356 	sk_acceptq_added(parent);
1357 }
1358 
1359 /* remove a socket from the accept queue of its parental listening socket */
1360 static void smc_accept_unlink(struct sock *sk)
1361 {
1362 	struct smc_sock *par = smc_sk(sk)->listen_smc;
1363 
1364 	spin_lock(&par->accept_q_lock);
1365 	list_del_init(&smc_sk(sk)->accept_q);
1366 	spin_unlock(&par->accept_q_lock);
1367 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
1368 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
1369 }
1370 
1371 /* remove a sock from the accept queue to bind it to a new socket created
1372  * for a socket accept call from user space
1373  */
1374 struct sock *smc_accept_dequeue(struct sock *parent,
1375 				struct socket *new_sock)
1376 {
1377 	struct smc_sock *isk, *n;
1378 	struct sock *new_sk;
1379 
1380 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
1381 		new_sk = (struct sock *)isk;
1382 
1383 		smc_accept_unlink(new_sk);
1384 		if (new_sk->sk_state == SMC_CLOSED) {
1385 			new_sk->sk_prot->unhash(new_sk);
1386 			if (isk->clcsock) {
1387 				sock_release(isk->clcsock);
1388 				isk->clcsock = NULL;
1389 			}
1390 			sock_put(new_sk); /* final */
1391 			continue;
1392 		}
1393 		if (new_sock) {
1394 			sock_graft(new_sk, new_sock);
1395 			if (isk->use_fallback) {
1396 				smc_sk(new_sk)->clcsock->file = new_sock->file;
1397 				isk->clcsock->file->private_data = isk->clcsock;
1398 			}
1399 		}
1400 		return new_sk;
1401 	}
1402 	return NULL;
1403 }
1404 
1405 /* clean up for a created but never accepted sock */
1406 void smc_close_non_accepted(struct sock *sk)
1407 {
1408 	struct smc_sock *smc = smc_sk(sk);
1409 
1410 	sock_hold(sk); /* sock_put below */
1411 	lock_sock(sk);
1412 	if (!sk->sk_lingertime)
1413 		/* wait for peer closing */
1414 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
1415 	__smc_release(smc);
1416 	release_sock(sk);
1417 	sock_put(sk); /* sock_hold above */
1418 	sock_put(sk); /* final sock_put */
1419 }
1420 
1421 static int smcr_serv_conf_first_link(struct smc_sock *smc)
1422 {
1423 	struct smc_link *link = smc->conn.lnk;
1424 	struct smc_llc_qentry *qentry;
1425 	int rc;
1426 
1427 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc))
1428 		return SMC_CLC_DECL_ERR_REGRMB;
1429 
1430 	/* send CONFIRM LINK request to client over the RoCE fabric */
1431 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
1432 	if (rc < 0)
1433 		return SMC_CLC_DECL_TIMEOUT_CL;
1434 
1435 	/* receive CONFIRM LINK response from client over the RoCE fabric */
1436 	qentry = smc_llc_wait(link->lgr, link, SMC_LLC_WAIT_TIME,
1437 			      SMC_LLC_CONFIRM_LINK);
1438 	if (!qentry) {
1439 		struct smc_clc_msg_decline dclc;
1440 
1441 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1442 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1443 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
1444 	}
1445 	smc_llc_save_peer_uid(qentry);
1446 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_RESP);
1447 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
1448 	if (rc)
1449 		return SMC_CLC_DECL_RMBE_EC;
1450 
1451 	/* confirm_rkey is implicit on 1st contact */
1452 	smc->conn.rmb_desc->is_conf_rkey = true;
1453 
1454 	smc_llc_link_active(link);
1455 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
1456 
1457 	/* initial contact - try to establish second link */
1458 	smc_llc_srv_add_link(link, NULL);
1459 	return 0;
1460 }
1461 
1462 /* listen worker: finish */
1463 static void smc_listen_out(struct smc_sock *new_smc)
1464 {
1465 	struct smc_sock *lsmc = new_smc->listen_smc;
1466 	struct sock *newsmcsk = &new_smc->sk;
1467 
1468 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1469 		lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1470 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1471 		release_sock(&lsmc->sk);
1472 	} else { /* no longer listening */
1473 		smc_close_non_accepted(newsmcsk);
1474 	}
1475 
1476 	/* Wake up accept */
1477 	lsmc->sk.sk_data_ready(&lsmc->sk);
1478 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1479 }
1480 
1481 /* listen worker: finish in state connected */
1482 static void smc_listen_out_connected(struct smc_sock *new_smc)
1483 {
1484 	struct sock *newsmcsk = &new_smc->sk;
1485 
1486 	sk_refcnt_debug_inc(newsmcsk);
1487 	if (newsmcsk->sk_state == SMC_INIT)
1488 		newsmcsk->sk_state = SMC_ACTIVE;
1489 
1490 	smc_listen_out(new_smc);
1491 }
1492 
1493 /* listen worker: finish in error state */
1494 static void smc_listen_out_err(struct smc_sock *new_smc)
1495 {
1496 	struct sock *newsmcsk = &new_smc->sk;
1497 	struct net *net = sock_net(newsmcsk);
1498 
1499 	this_cpu_inc(net->smc.smc_stats->srv_hshake_err_cnt);
1500 	if (newsmcsk->sk_state == SMC_INIT)
1501 		sock_put(&new_smc->sk); /* passive closing */
1502 	newsmcsk->sk_state = SMC_CLOSED;
1503 
1504 	smc_listen_out(new_smc);
1505 }
1506 
1507 /* listen worker: decline and fall back if possible */
1508 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1509 			       int local_first, u8 version)
1510 {
1511 	/* RDMA setup failed, switch back to TCP */
1512 	smc_conn_abort(new_smc, local_first);
1513 	if (reason_code < 0) { /* error, no fallback possible */
1514 		smc_listen_out_err(new_smc);
1515 		return;
1516 	}
1517 	smc_switch_to_fallback(new_smc, reason_code);
1518 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1519 		if (smc_clc_send_decline(new_smc, reason_code, version) < 0) {
1520 			smc_listen_out_err(new_smc);
1521 			return;
1522 		}
1523 	}
1524 	smc_listen_out_connected(new_smc);
1525 }
1526 
1527 /* listen worker: version checking */
1528 static int smc_listen_v2_check(struct smc_sock *new_smc,
1529 			       struct smc_clc_msg_proposal *pclc,
1530 			       struct smc_init_info *ini)
1531 {
1532 	struct smc_clc_smcd_v2_extension *pclc_smcd_v2_ext;
1533 	struct smc_clc_v2_extension *pclc_v2_ext;
1534 	int rc = SMC_CLC_DECL_PEERNOSMC;
1535 
1536 	ini->smc_type_v1 = pclc->hdr.typev1;
1537 	ini->smc_type_v2 = pclc->hdr.typev2;
1538 	ini->smcd_version = smcd_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
1539 	ini->smcr_version = smcr_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
1540 	if (pclc->hdr.version > SMC_V1) {
1541 		if (smcd_indicated(ini->smc_type_v2))
1542 			ini->smcd_version |= SMC_V2;
1543 		if (smcr_indicated(ini->smc_type_v2))
1544 			ini->smcr_version |= SMC_V2;
1545 	}
1546 	if (!(ini->smcd_version & SMC_V2) && !(ini->smcr_version & SMC_V2)) {
1547 		rc = SMC_CLC_DECL_PEERNOSMC;
1548 		goto out;
1549 	}
1550 	pclc_v2_ext = smc_get_clc_v2_ext(pclc);
1551 	if (!pclc_v2_ext) {
1552 		ini->smcd_version &= ~SMC_V2;
1553 		ini->smcr_version &= ~SMC_V2;
1554 		rc = SMC_CLC_DECL_NOV2EXT;
1555 		goto out;
1556 	}
1557 	pclc_smcd_v2_ext = smc_get_clc_smcd_v2_ext(pclc_v2_ext);
1558 	if (ini->smcd_version & SMC_V2) {
1559 		if (!smc_ism_is_v2_capable()) {
1560 			ini->smcd_version &= ~SMC_V2;
1561 			rc = SMC_CLC_DECL_NOISM2SUPP;
1562 		} else if (!pclc_smcd_v2_ext) {
1563 			ini->smcd_version &= ~SMC_V2;
1564 			rc = SMC_CLC_DECL_NOV2DEXT;
1565 		} else if (!pclc_v2_ext->hdr.eid_cnt &&
1566 			   !pclc_v2_ext->hdr.flag.seid) {
1567 			ini->smcd_version &= ~SMC_V2;
1568 			rc = SMC_CLC_DECL_NOUEID;
1569 		}
1570 	}
1571 	if (ini->smcr_version & SMC_V2) {
1572 		if (!pclc_v2_ext->hdr.eid_cnt) {
1573 			ini->smcr_version &= ~SMC_V2;
1574 			rc = SMC_CLC_DECL_NOUEID;
1575 		}
1576 	}
1577 
1578 out:
1579 	if (!ini->smcd_version && !ini->smcr_version)
1580 		return rc;
1581 
1582 	return 0;
1583 }
1584 
1585 /* listen worker: check prefixes */
1586 static int smc_listen_prfx_check(struct smc_sock *new_smc,
1587 				 struct smc_clc_msg_proposal *pclc)
1588 {
1589 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1590 	struct socket *newclcsock = new_smc->clcsock;
1591 
1592 	if (pclc->hdr.typev1 == SMC_TYPE_N)
1593 		return 0;
1594 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1595 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1596 		return SMC_CLC_DECL_DIFFPREFIX;
1597 
1598 	return 0;
1599 }
1600 
1601 /* listen worker: initialize connection and buffers */
1602 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1603 				struct smc_init_info *ini)
1604 {
1605 	int rc;
1606 
1607 	/* allocate connection / link group */
1608 	rc = smc_conn_create(new_smc, ini);
1609 	if (rc)
1610 		return rc;
1611 
1612 	/* create send buffer and rmb */
1613 	if (smc_buf_create(new_smc, false))
1614 		return SMC_CLC_DECL_MEM;
1615 
1616 	return 0;
1617 }
1618 
1619 /* listen worker: initialize connection and buffers for SMC-D */
1620 static int smc_listen_ism_init(struct smc_sock *new_smc,
1621 			       struct smc_init_info *ini)
1622 {
1623 	int rc;
1624 
1625 	rc = smc_conn_create(new_smc, ini);
1626 	if (rc)
1627 		return rc;
1628 
1629 	/* Create send and receive buffers */
1630 	rc = smc_buf_create(new_smc, true);
1631 	if (rc) {
1632 		smc_conn_abort(new_smc, ini->first_contact_local);
1633 		return (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB :
1634 					 SMC_CLC_DECL_MEM;
1635 	}
1636 
1637 	return 0;
1638 }
1639 
1640 static bool smc_is_already_selected(struct smcd_dev *smcd,
1641 				    struct smc_init_info *ini,
1642 				    int matches)
1643 {
1644 	int i;
1645 
1646 	for (i = 0; i < matches; i++)
1647 		if (smcd == ini->ism_dev[i])
1648 			return true;
1649 
1650 	return false;
1651 }
1652 
1653 /* check for ISM devices matching proposed ISM devices */
1654 static void smc_check_ism_v2_match(struct smc_init_info *ini,
1655 				   u16 proposed_chid, u64 proposed_gid,
1656 				   unsigned int *matches)
1657 {
1658 	struct smcd_dev *smcd;
1659 
1660 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
1661 		if (smcd->going_away)
1662 			continue;
1663 		if (smc_is_already_selected(smcd, ini, *matches))
1664 			continue;
1665 		if (smc_ism_get_chid(smcd) == proposed_chid &&
1666 		    !smc_ism_cantalk(proposed_gid, ISM_RESERVED_VLANID, smcd)) {
1667 			ini->ism_peer_gid[*matches] = proposed_gid;
1668 			ini->ism_dev[*matches] = smcd;
1669 			(*matches)++;
1670 			break;
1671 		}
1672 	}
1673 }
1674 
1675 static void smc_find_ism_store_rc(u32 rc, struct smc_init_info *ini)
1676 {
1677 	if (!ini->rc)
1678 		ini->rc = rc;
1679 }
1680 
1681 static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
1682 					struct smc_clc_msg_proposal *pclc,
1683 					struct smc_init_info *ini)
1684 {
1685 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
1686 	struct smc_clc_v2_extension *smc_v2_ext;
1687 	struct smc_clc_msg_smcd *pclc_smcd;
1688 	unsigned int matches = 0;
1689 	u8 smcd_version;
1690 	u8 *eid = NULL;
1691 	int i, rc;
1692 
1693 	if (!(ini->smcd_version & SMC_V2) || !smcd_indicated(ini->smc_type_v2))
1694 		goto not_found;
1695 
1696 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
1697 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
1698 	smcd_v2_ext = smc_get_clc_smcd_v2_ext(smc_v2_ext);
1699 
1700 	mutex_lock(&smcd_dev_list.mutex);
1701 	if (pclc_smcd->ism.chid)
1702 		/* check for ISM device matching proposed native ISM device */
1703 		smc_check_ism_v2_match(ini, ntohs(pclc_smcd->ism.chid),
1704 				       ntohll(pclc_smcd->ism.gid), &matches);
1705 	for (i = 1; i <= smc_v2_ext->hdr.ism_gid_cnt; i++) {
1706 		/* check for ISM devices matching proposed non-native ISM
1707 		 * devices
1708 		 */
1709 		smc_check_ism_v2_match(ini,
1710 				       ntohs(smcd_v2_ext->gidchid[i - 1].chid),
1711 				       ntohll(smcd_v2_ext->gidchid[i - 1].gid),
1712 				       &matches);
1713 	}
1714 	mutex_unlock(&smcd_dev_list.mutex);
1715 
1716 	if (!ini->ism_dev[0]) {
1717 		smc_find_ism_store_rc(SMC_CLC_DECL_NOSMCD2DEV, ini);
1718 		goto not_found;
1719 	}
1720 
1721 	smc_ism_get_system_eid(&eid);
1722 	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext,
1723 			       smcd_v2_ext->system_eid, eid))
1724 		goto not_found;
1725 
1726 	/* separate - outside the smcd_dev_list.lock */
1727 	smcd_version = ini->smcd_version;
1728 	for (i = 0; i < matches; i++) {
1729 		ini->smcd_version = SMC_V2;
1730 		ini->is_smcd = true;
1731 		ini->ism_selected = i;
1732 		rc = smc_listen_ism_init(new_smc, ini);
1733 		if (rc) {
1734 			smc_find_ism_store_rc(rc, ini);
1735 			/* try next active ISM device */
1736 			continue;
1737 		}
1738 		return; /* matching and usable V2 ISM device found */
1739 	}
1740 	/* no V2 ISM device could be initialized */
1741 	ini->smcd_version = smcd_version;	/* restore original value */
1742 	ini->negotiated_eid[0] = 0;
1743 
1744 not_found:
1745 	ini->smcd_version &= ~SMC_V2;
1746 	ini->ism_dev[0] = NULL;
1747 	ini->is_smcd = false;
1748 }
1749 
1750 static void smc_find_ism_v1_device_serv(struct smc_sock *new_smc,
1751 					struct smc_clc_msg_proposal *pclc,
1752 					struct smc_init_info *ini)
1753 {
1754 	struct smc_clc_msg_smcd *pclc_smcd = smc_get_clc_msg_smcd(pclc);
1755 	int rc = 0;
1756 
1757 	/* check if ISM V1 is available */
1758 	if (!(ini->smcd_version & SMC_V1) || !smcd_indicated(ini->smc_type_v1))
1759 		goto not_found;
1760 	ini->is_smcd = true; /* prepare ISM check */
1761 	ini->ism_peer_gid[0] = ntohll(pclc_smcd->ism.gid);
1762 	rc = smc_find_ism_device(new_smc, ini);
1763 	if (rc)
1764 		goto not_found;
1765 	ini->ism_selected = 0;
1766 	rc = smc_listen_ism_init(new_smc, ini);
1767 	if (!rc)
1768 		return;		/* V1 ISM device found */
1769 
1770 not_found:
1771 	smc_find_ism_store_rc(rc, ini);
1772 	ini->smcd_version &= ~SMC_V1;
1773 	ini->ism_dev[0] = NULL;
1774 	ini->is_smcd = false;
1775 }
1776 
1777 /* listen worker: register buffers */
1778 static int smc_listen_rdma_reg(struct smc_sock *new_smc, bool local_first)
1779 {
1780 	struct smc_connection *conn = &new_smc->conn;
1781 
1782 	if (!local_first) {
1783 		if (smcr_lgr_reg_rmbs(conn->lnk, conn->rmb_desc))
1784 			return SMC_CLC_DECL_ERR_REGRMB;
1785 	}
1786 	smc_rmb_sync_sg_for_device(&new_smc->conn);
1787 
1788 	return 0;
1789 }
1790 
1791 static void smc_find_rdma_v2_device_serv(struct smc_sock *new_smc,
1792 					 struct smc_clc_msg_proposal *pclc,
1793 					 struct smc_init_info *ini)
1794 {
1795 	struct smc_clc_v2_extension *smc_v2_ext;
1796 	u8 smcr_version;
1797 	int rc;
1798 
1799 	if (!(ini->smcr_version & SMC_V2) || !smcr_indicated(ini->smc_type_v2))
1800 		goto not_found;
1801 
1802 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
1803 	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext, NULL, NULL))
1804 		goto not_found;
1805 
1806 	/* prepare RDMA check */
1807 	memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
1808 	memcpy(ini->peer_gid, smc_v2_ext->roce, SMC_GID_SIZE);
1809 	memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
1810 	ini->check_smcrv2 = true;
1811 	ini->smcrv2.clc_sk = new_smc->clcsock->sk;
1812 	ini->smcrv2.saddr = new_smc->clcsock->sk->sk_rcv_saddr;
1813 	ini->smcrv2.daddr = smc_ib_gid_to_ipv4(smc_v2_ext->roce);
1814 	rc = smc_find_rdma_device(new_smc, ini);
1815 	if (rc) {
1816 		smc_find_ism_store_rc(rc, ini);
1817 		goto not_found;
1818 	}
1819 	if (!ini->smcrv2.uses_gateway)
1820 		memcpy(ini->smcrv2.nexthop_mac, pclc->lcl.mac, ETH_ALEN);
1821 
1822 	smcr_version = ini->smcr_version;
1823 	ini->smcr_version = SMC_V2;
1824 	rc = smc_listen_rdma_init(new_smc, ini);
1825 	if (!rc)
1826 		rc = smc_listen_rdma_reg(new_smc, ini->first_contact_local);
1827 	if (!rc)
1828 		return;
1829 	ini->smcr_version = smcr_version;
1830 	smc_find_ism_store_rc(rc, ini);
1831 
1832 not_found:
1833 	ini->smcr_version &= ~SMC_V2;
1834 	ini->check_smcrv2 = false;
1835 }
1836 
1837 static int smc_find_rdma_v1_device_serv(struct smc_sock *new_smc,
1838 					struct smc_clc_msg_proposal *pclc,
1839 					struct smc_init_info *ini)
1840 {
1841 	int rc;
1842 
1843 	if (!(ini->smcr_version & SMC_V1) || !smcr_indicated(ini->smc_type_v1))
1844 		return SMC_CLC_DECL_NOSMCDEV;
1845 
1846 	/* prepare RDMA check */
1847 	memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
1848 	memcpy(ini->peer_gid, pclc->lcl.gid, SMC_GID_SIZE);
1849 	memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
1850 	rc = smc_find_rdma_device(new_smc, ini);
1851 	if (rc) {
1852 		/* no RDMA device found */
1853 		return SMC_CLC_DECL_NOSMCDEV;
1854 	}
1855 	rc = smc_listen_rdma_init(new_smc, ini);
1856 	if (rc)
1857 		return rc;
1858 	return smc_listen_rdma_reg(new_smc, ini->first_contact_local);
1859 }
1860 
1861 /* determine the local device matching to proposal */
1862 static int smc_listen_find_device(struct smc_sock *new_smc,
1863 				  struct smc_clc_msg_proposal *pclc,
1864 				  struct smc_init_info *ini)
1865 {
1866 	int prfx_rc;
1867 
1868 	/* check for ISM device matching V2 proposed device */
1869 	smc_find_ism_v2_device_serv(new_smc, pclc, ini);
1870 	if (ini->ism_dev[0])
1871 		return 0;
1872 
1873 	/* check for matching IP prefix and subnet length (V1) */
1874 	prfx_rc = smc_listen_prfx_check(new_smc, pclc);
1875 	if (prfx_rc)
1876 		smc_find_ism_store_rc(prfx_rc, ini);
1877 
1878 	/* get vlan id from IP device */
1879 	if (smc_vlan_by_tcpsk(new_smc->clcsock, ini))
1880 		return ini->rc ?: SMC_CLC_DECL_GETVLANERR;
1881 
1882 	/* check for ISM device matching V1 proposed device */
1883 	if (!prfx_rc)
1884 		smc_find_ism_v1_device_serv(new_smc, pclc, ini);
1885 	if (ini->ism_dev[0])
1886 		return 0;
1887 
1888 	if (!smcr_indicated(pclc->hdr.typev1) &&
1889 	    !smcr_indicated(pclc->hdr.typev2))
1890 		/* skip RDMA and decline */
1891 		return ini->rc ?: SMC_CLC_DECL_NOSMCDDEV;
1892 
1893 	/* check if RDMA V2 is available */
1894 	smc_find_rdma_v2_device_serv(new_smc, pclc, ini);
1895 	if (ini->smcrv2.ib_dev_v2)
1896 		return 0;
1897 
1898 	/* check if RDMA V1 is available */
1899 	if (!prfx_rc) {
1900 		int rc;
1901 
1902 		rc = smc_find_rdma_v1_device_serv(new_smc, pclc, ini);
1903 		smc_find_ism_store_rc(rc, ini);
1904 		return (!rc) ? 0 : ini->rc;
1905 	}
1906 	return SMC_CLC_DECL_NOSMCDEV;
1907 }
1908 
1909 /* listen worker: finish RDMA setup */
1910 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
1911 				  struct smc_clc_msg_accept_confirm *cclc,
1912 				  bool local_first,
1913 				  struct smc_init_info *ini)
1914 {
1915 	struct smc_link *link = new_smc->conn.lnk;
1916 	int reason_code = 0;
1917 
1918 	if (local_first)
1919 		smc_link_save_peer_info(link, cclc, ini);
1920 
1921 	if (smc_rmb_rtoken_handling(&new_smc->conn, link, cclc))
1922 		return SMC_CLC_DECL_ERR_RTOK;
1923 
1924 	if (local_first) {
1925 		if (smc_ib_ready_link(link))
1926 			return SMC_CLC_DECL_ERR_RDYLNK;
1927 		/* QP confirmation over RoCE fabric */
1928 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
1929 		reason_code = smcr_serv_conf_first_link(new_smc);
1930 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
1931 	}
1932 	return reason_code;
1933 }
1934 
1935 /* setup for connection of server */
1936 static void smc_listen_work(struct work_struct *work)
1937 {
1938 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
1939 						smc_listen_work);
1940 	struct socket *newclcsock = new_smc->clcsock;
1941 	struct smc_clc_msg_accept_confirm *cclc;
1942 	struct smc_clc_msg_proposal_area *buf;
1943 	struct smc_clc_msg_proposal *pclc;
1944 	struct smc_init_info *ini = NULL;
1945 	u8 proposal_version = SMC_V1;
1946 	u8 accept_version;
1947 	int rc = 0;
1948 
1949 	if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
1950 		return smc_listen_out_err(new_smc);
1951 
1952 	if (new_smc->use_fallback) {
1953 		smc_listen_out_connected(new_smc);
1954 		return;
1955 	}
1956 
1957 	/* check if peer is smc capable */
1958 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
1959 		smc_switch_to_fallback(new_smc, SMC_CLC_DECL_PEERNOSMC);
1960 		smc_listen_out_connected(new_smc);
1961 		return;
1962 	}
1963 
1964 	/* do inband token exchange -
1965 	 * wait for and receive SMC Proposal CLC message
1966 	 */
1967 	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
1968 	if (!buf) {
1969 		rc = SMC_CLC_DECL_MEM;
1970 		goto out_decl;
1971 	}
1972 	pclc = (struct smc_clc_msg_proposal *)buf;
1973 	rc = smc_clc_wait_msg(new_smc, pclc, sizeof(*buf),
1974 			      SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
1975 	if (rc)
1976 		goto out_decl;
1977 
1978 	if (pclc->hdr.version > SMC_V1)
1979 		proposal_version = SMC_V2;
1980 
1981 	/* IPSec connections opt out of SMC optimizations */
1982 	if (using_ipsec(new_smc)) {
1983 		rc = SMC_CLC_DECL_IPSEC;
1984 		goto out_decl;
1985 	}
1986 
1987 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1988 	if (!ini) {
1989 		rc = SMC_CLC_DECL_MEM;
1990 		goto out_decl;
1991 	}
1992 
1993 	/* initial version checking */
1994 	rc = smc_listen_v2_check(new_smc, pclc, ini);
1995 	if (rc)
1996 		goto out_decl;
1997 
1998 	mutex_lock(&smc_server_lgr_pending);
1999 	smc_close_init(new_smc);
2000 	smc_rx_init(new_smc);
2001 	smc_tx_init(new_smc);
2002 
2003 	/* determine ISM or RoCE device used for connection */
2004 	rc = smc_listen_find_device(new_smc, pclc, ini);
2005 	if (rc)
2006 		goto out_unlock;
2007 
2008 	/* send SMC Accept CLC message */
2009 	accept_version = ini->is_smcd ? ini->smcd_version : ini->smcr_version;
2010 	rc = smc_clc_send_accept(new_smc, ini->first_contact_local,
2011 				 accept_version, ini->negotiated_eid);
2012 	if (rc)
2013 		goto out_unlock;
2014 
2015 	/* SMC-D does not need this lock any more */
2016 	if (ini->is_smcd)
2017 		mutex_unlock(&smc_server_lgr_pending);
2018 
2019 	/* receive SMC Confirm CLC message */
2020 	memset(buf, 0, sizeof(*buf));
2021 	cclc = (struct smc_clc_msg_accept_confirm *)buf;
2022 	rc = smc_clc_wait_msg(new_smc, cclc, sizeof(*buf),
2023 			      SMC_CLC_CONFIRM, CLC_WAIT_TIME);
2024 	if (rc) {
2025 		if (!ini->is_smcd)
2026 			goto out_unlock;
2027 		goto out_decl;
2028 	}
2029 
2030 	/* finish worker */
2031 	if (!ini->is_smcd) {
2032 		rc = smc_listen_rdma_finish(new_smc, cclc,
2033 					    ini->first_contact_local, ini);
2034 		if (rc)
2035 			goto out_unlock;
2036 		mutex_unlock(&smc_server_lgr_pending);
2037 	}
2038 	smc_conn_save_peer_info(new_smc, cclc);
2039 	smc_listen_out_connected(new_smc);
2040 	SMC_STAT_SERV_SUCC_INC(sock_net(newclcsock->sk), ini);
2041 	goto out_free;
2042 
2043 out_unlock:
2044 	mutex_unlock(&smc_server_lgr_pending);
2045 out_decl:
2046 	smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0,
2047 			   proposal_version);
2048 out_free:
2049 	kfree(ini);
2050 	kfree(buf);
2051 }
2052 
2053 static void smc_tcp_listen_work(struct work_struct *work)
2054 {
2055 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
2056 					     tcp_listen_work);
2057 	struct sock *lsk = &lsmc->sk;
2058 	struct smc_sock *new_smc;
2059 	int rc = 0;
2060 
2061 	lock_sock(lsk);
2062 	while (lsk->sk_state == SMC_LISTEN) {
2063 		rc = smc_clcsock_accept(lsmc, &new_smc);
2064 		if (rc) /* clcsock accept queue empty or error */
2065 			goto out;
2066 		if (!new_smc)
2067 			continue;
2068 
2069 		new_smc->listen_smc = lsmc;
2070 		new_smc->use_fallback = lsmc->use_fallback;
2071 		new_smc->fallback_rsn = lsmc->fallback_rsn;
2072 		sock_hold(lsk); /* sock_put in smc_listen_work */
2073 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
2074 		smc_copy_sock_settings_to_smc(new_smc);
2075 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
2076 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
2077 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
2078 		if (!queue_work(smc_hs_wq, &new_smc->smc_listen_work))
2079 			sock_put(&new_smc->sk);
2080 	}
2081 
2082 out:
2083 	release_sock(lsk);
2084 	sock_put(&lsmc->sk); /* sock_hold in smc_clcsock_data_ready() */
2085 }
2086 
2087 static void smc_clcsock_data_ready(struct sock *listen_clcsock)
2088 {
2089 	struct smc_sock *lsmc;
2090 
2091 	lsmc = (struct smc_sock *)
2092 	       ((uintptr_t)listen_clcsock->sk_user_data & ~SK_USER_DATA_NOCOPY);
2093 	if (!lsmc)
2094 		return;
2095 	lsmc->clcsk_data_ready(listen_clcsock);
2096 	if (lsmc->sk.sk_state == SMC_LISTEN) {
2097 		sock_hold(&lsmc->sk); /* sock_put in smc_tcp_listen_work() */
2098 		if (!queue_work(smc_hs_wq, &lsmc->tcp_listen_work))
2099 			sock_put(&lsmc->sk);
2100 	}
2101 }
2102 
2103 static int smc_listen(struct socket *sock, int backlog)
2104 {
2105 	struct sock *sk = sock->sk;
2106 	struct smc_sock *smc;
2107 	int rc;
2108 
2109 	smc = smc_sk(sk);
2110 	lock_sock(sk);
2111 
2112 	rc = -EINVAL;
2113 	if ((sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) ||
2114 	    smc->connect_nonblock)
2115 		goto out;
2116 
2117 	rc = 0;
2118 	if (sk->sk_state == SMC_LISTEN) {
2119 		sk->sk_max_ack_backlog = backlog;
2120 		goto out;
2121 	}
2122 	/* some socket options are handled in core, so we could not apply
2123 	 * them to the clc socket -- copy smc socket options to clc socket
2124 	 */
2125 	smc_copy_sock_settings_to_clc(smc);
2126 	if (!smc->use_fallback)
2127 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
2128 
2129 	/* save original sk_data_ready function and establish
2130 	 * smc-specific sk_data_ready function
2131 	 */
2132 	smc->clcsk_data_ready = smc->clcsock->sk->sk_data_ready;
2133 	smc->clcsock->sk->sk_data_ready = smc_clcsock_data_ready;
2134 	smc->clcsock->sk->sk_user_data =
2135 		(void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
2136 	rc = kernel_listen(smc->clcsock, backlog);
2137 	if (rc) {
2138 		smc->clcsock->sk->sk_data_ready = smc->clcsk_data_ready;
2139 		goto out;
2140 	}
2141 	sk->sk_max_ack_backlog = backlog;
2142 	sk->sk_ack_backlog = 0;
2143 	sk->sk_state = SMC_LISTEN;
2144 
2145 out:
2146 	release_sock(sk);
2147 	return rc;
2148 }
2149 
2150 static int smc_accept(struct socket *sock, struct socket *new_sock,
2151 		      int flags, bool kern)
2152 {
2153 	struct sock *sk = sock->sk, *nsk;
2154 	DECLARE_WAITQUEUE(wait, current);
2155 	struct smc_sock *lsmc;
2156 	long timeo;
2157 	int rc = 0;
2158 
2159 	lsmc = smc_sk(sk);
2160 	sock_hold(sk); /* sock_put below */
2161 	lock_sock(sk);
2162 
2163 	if (lsmc->sk.sk_state != SMC_LISTEN) {
2164 		rc = -EINVAL;
2165 		release_sock(sk);
2166 		goto out;
2167 	}
2168 
2169 	/* Wait for an incoming connection */
2170 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
2171 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
2172 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
2173 		set_current_state(TASK_INTERRUPTIBLE);
2174 		if (!timeo) {
2175 			rc = -EAGAIN;
2176 			break;
2177 		}
2178 		release_sock(sk);
2179 		timeo = schedule_timeout(timeo);
2180 		/* wakeup by sk_data_ready in smc_listen_work() */
2181 		sched_annotate_sleep();
2182 		lock_sock(sk);
2183 		if (signal_pending(current)) {
2184 			rc = sock_intr_errno(timeo);
2185 			break;
2186 		}
2187 	}
2188 	set_current_state(TASK_RUNNING);
2189 	remove_wait_queue(sk_sleep(sk), &wait);
2190 
2191 	if (!rc)
2192 		rc = sock_error(nsk);
2193 	release_sock(sk);
2194 	if (rc)
2195 		goto out;
2196 
2197 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
2198 		/* wait till data arrives on the socket */
2199 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
2200 								MSEC_PER_SEC);
2201 		if (smc_sk(nsk)->use_fallback) {
2202 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
2203 
2204 			lock_sock(clcsk);
2205 			if (skb_queue_empty(&clcsk->sk_receive_queue))
2206 				sk_wait_data(clcsk, &timeo, NULL);
2207 			release_sock(clcsk);
2208 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
2209 			lock_sock(nsk);
2210 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
2211 			release_sock(nsk);
2212 		}
2213 	}
2214 
2215 out:
2216 	sock_put(sk); /* sock_hold above */
2217 	return rc;
2218 }
2219 
2220 static int smc_getname(struct socket *sock, struct sockaddr *addr,
2221 		       int peer)
2222 {
2223 	struct smc_sock *smc;
2224 
2225 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
2226 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
2227 		return -ENOTCONN;
2228 
2229 	smc = smc_sk(sock->sk);
2230 
2231 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
2232 }
2233 
2234 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2235 {
2236 	struct sock *sk = sock->sk;
2237 	struct smc_sock *smc;
2238 	int rc = -EPIPE;
2239 
2240 	smc = smc_sk(sk);
2241 	lock_sock(sk);
2242 	if ((sk->sk_state != SMC_ACTIVE) &&
2243 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2244 	    (sk->sk_state != SMC_INIT))
2245 		goto out;
2246 
2247 	if (msg->msg_flags & MSG_FASTOPEN) {
2248 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2249 			smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2250 		} else {
2251 			rc = -EINVAL;
2252 			goto out;
2253 		}
2254 	}
2255 
2256 	if (smc->use_fallback) {
2257 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
2258 	} else {
2259 		rc = smc_tx_sendmsg(smc, msg, len);
2260 		SMC_STAT_TX_PAYLOAD(smc, len, rc);
2261 	}
2262 out:
2263 	release_sock(sk);
2264 	return rc;
2265 }
2266 
2267 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2268 		       int flags)
2269 {
2270 	struct sock *sk = sock->sk;
2271 	struct smc_sock *smc;
2272 	int rc = -ENOTCONN;
2273 
2274 	smc = smc_sk(sk);
2275 	lock_sock(sk);
2276 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2277 		/* socket was connected before, no more data to read */
2278 		rc = 0;
2279 		goto out;
2280 	}
2281 	if ((sk->sk_state == SMC_INIT) ||
2282 	    (sk->sk_state == SMC_LISTEN) ||
2283 	    (sk->sk_state == SMC_CLOSED))
2284 		goto out;
2285 
2286 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2287 		rc = 0;
2288 		goto out;
2289 	}
2290 
2291 	if (smc->use_fallback) {
2292 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
2293 	} else {
2294 		msg->msg_namelen = 0;
2295 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
2296 		SMC_STAT_RX_PAYLOAD(smc, rc, rc);
2297 	}
2298 
2299 out:
2300 	release_sock(sk);
2301 	return rc;
2302 }
2303 
2304 static __poll_t smc_accept_poll(struct sock *parent)
2305 {
2306 	struct smc_sock *isk = smc_sk(parent);
2307 	__poll_t mask = 0;
2308 
2309 	spin_lock(&isk->accept_q_lock);
2310 	if (!list_empty(&isk->accept_q))
2311 		mask = EPOLLIN | EPOLLRDNORM;
2312 	spin_unlock(&isk->accept_q_lock);
2313 
2314 	return mask;
2315 }
2316 
2317 static __poll_t smc_poll(struct file *file, struct socket *sock,
2318 			     poll_table *wait)
2319 {
2320 	struct sock *sk = sock->sk;
2321 	struct smc_sock *smc;
2322 	__poll_t mask = 0;
2323 
2324 	if (!sk)
2325 		return EPOLLNVAL;
2326 
2327 	smc = smc_sk(sock->sk);
2328 	if (smc->use_fallback) {
2329 		/* delegate to CLC child sock */
2330 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
2331 		sk->sk_err = smc->clcsock->sk->sk_err;
2332 	} else {
2333 		if (sk->sk_state != SMC_CLOSED)
2334 			sock_poll_wait(file, sock, wait);
2335 		if (sk->sk_err)
2336 			mask |= EPOLLERR;
2337 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
2338 		    (sk->sk_state == SMC_CLOSED))
2339 			mask |= EPOLLHUP;
2340 		if (sk->sk_state == SMC_LISTEN) {
2341 			/* woken up by sk_data_ready in smc_listen_work() */
2342 			mask |= smc_accept_poll(sk);
2343 		} else if (smc->use_fallback) { /* as result of connect_work()*/
2344 			mask |= smc->clcsock->ops->poll(file, smc->clcsock,
2345 							   wait);
2346 			sk->sk_err = smc->clcsock->sk->sk_err;
2347 		} else {
2348 			if ((sk->sk_state != SMC_INIT &&
2349 			     atomic_read(&smc->conn.sndbuf_space)) ||
2350 			    sk->sk_shutdown & SEND_SHUTDOWN) {
2351 				mask |= EPOLLOUT | EPOLLWRNORM;
2352 			} else {
2353 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2354 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2355 			}
2356 			if (atomic_read(&smc->conn.bytes_to_rcv))
2357 				mask |= EPOLLIN | EPOLLRDNORM;
2358 			if (sk->sk_shutdown & RCV_SHUTDOWN)
2359 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
2360 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
2361 				mask |= EPOLLIN;
2362 			if (smc->conn.urg_state == SMC_URG_VALID)
2363 				mask |= EPOLLPRI;
2364 		}
2365 	}
2366 
2367 	return mask;
2368 }
2369 
2370 static int smc_shutdown(struct socket *sock, int how)
2371 {
2372 	struct sock *sk = sock->sk;
2373 	bool do_shutdown = true;
2374 	struct smc_sock *smc;
2375 	int rc = -EINVAL;
2376 	int old_state;
2377 	int rc1 = 0;
2378 
2379 	smc = smc_sk(sk);
2380 
2381 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
2382 		return rc;
2383 
2384 	lock_sock(sk);
2385 
2386 	rc = -ENOTCONN;
2387 	if ((sk->sk_state != SMC_ACTIVE) &&
2388 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
2389 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
2390 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2391 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
2392 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
2393 		goto out;
2394 	if (smc->use_fallback) {
2395 		rc = kernel_sock_shutdown(smc->clcsock, how);
2396 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
2397 		if (sk->sk_shutdown == SHUTDOWN_MASK)
2398 			sk->sk_state = SMC_CLOSED;
2399 		goto out;
2400 	}
2401 	switch (how) {
2402 	case SHUT_RDWR:		/* shutdown in both directions */
2403 		old_state = sk->sk_state;
2404 		rc = smc_close_active(smc);
2405 		if (old_state == SMC_ACTIVE &&
2406 		    sk->sk_state == SMC_PEERCLOSEWAIT1)
2407 			do_shutdown = false;
2408 		break;
2409 	case SHUT_WR:
2410 		rc = smc_close_shutdown_write(smc);
2411 		break;
2412 	case SHUT_RD:
2413 		rc = 0;
2414 		/* nothing more to do because peer is not involved */
2415 		break;
2416 	}
2417 	if (do_shutdown && smc->clcsock)
2418 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
2419 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
2420 	sk->sk_shutdown |= how + 1;
2421 
2422 out:
2423 	release_sock(sk);
2424 	return rc ? rc : rc1;
2425 }
2426 
2427 static int smc_setsockopt(struct socket *sock, int level, int optname,
2428 			  sockptr_t optval, unsigned int optlen)
2429 {
2430 	struct sock *sk = sock->sk;
2431 	struct smc_sock *smc;
2432 	int val, rc;
2433 
2434 	if (level == SOL_TCP && optname == TCP_ULP)
2435 		return -EOPNOTSUPP;
2436 
2437 	smc = smc_sk(sk);
2438 
2439 	/* generic setsockopts reaching us here always apply to the
2440 	 * CLC socket
2441 	 */
2442 	if (unlikely(!smc->clcsock->ops->setsockopt))
2443 		rc = -EOPNOTSUPP;
2444 	else
2445 		rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
2446 						   optval, optlen);
2447 	if (smc->clcsock->sk->sk_err) {
2448 		sk->sk_err = smc->clcsock->sk->sk_err;
2449 		sk_error_report(sk);
2450 	}
2451 
2452 	if (optlen < sizeof(int))
2453 		return -EINVAL;
2454 	if (copy_from_sockptr(&val, optval, sizeof(int)))
2455 		return -EFAULT;
2456 
2457 	lock_sock(sk);
2458 	if (rc || smc->use_fallback)
2459 		goto out;
2460 	switch (optname) {
2461 	case TCP_FASTOPEN:
2462 	case TCP_FASTOPEN_CONNECT:
2463 	case TCP_FASTOPEN_KEY:
2464 	case TCP_FASTOPEN_NO_COOKIE:
2465 		/* option not supported by SMC */
2466 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2467 			smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2468 		} else {
2469 			rc = -EINVAL;
2470 		}
2471 		break;
2472 	case TCP_NODELAY:
2473 		if (sk->sk_state != SMC_INIT &&
2474 		    sk->sk_state != SMC_LISTEN &&
2475 		    sk->sk_state != SMC_CLOSED) {
2476 			if (val) {
2477 				SMC_STAT_INC(smc, ndly_cnt);
2478 				mod_delayed_work(smc->conn.lgr->tx_wq,
2479 						 &smc->conn.tx_work, 0);
2480 			}
2481 		}
2482 		break;
2483 	case TCP_CORK:
2484 		if (sk->sk_state != SMC_INIT &&
2485 		    sk->sk_state != SMC_LISTEN &&
2486 		    sk->sk_state != SMC_CLOSED) {
2487 			if (!val) {
2488 				SMC_STAT_INC(smc, cork_cnt);
2489 				mod_delayed_work(smc->conn.lgr->tx_wq,
2490 						 &smc->conn.tx_work, 0);
2491 			}
2492 		}
2493 		break;
2494 	case TCP_DEFER_ACCEPT:
2495 		smc->sockopt_defer_accept = val;
2496 		break;
2497 	default:
2498 		break;
2499 	}
2500 out:
2501 	release_sock(sk);
2502 
2503 	return rc;
2504 }
2505 
2506 static int smc_getsockopt(struct socket *sock, int level, int optname,
2507 			  char __user *optval, int __user *optlen)
2508 {
2509 	struct smc_sock *smc;
2510 
2511 	smc = smc_sk(sock->sk);
2512 	/* socket options apply to the CLC socket */
2513 	if (unlikely(!smc->clcsock->ops->getsockopt))
2514 		return -EOPNOTSUPP;
2515 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
2516 					     optval, optlen);
2517 }
2518 
2519 static int smc_ioctl(struct socket *sock, unsigned int cmd,
2520 		     unsigned long arg)
2521 {
2522 	union smc_host_cursor cons, urg;
2523 	struct smc_connection *conn;
2524 	struct smc_sock *smc;
2525 	int answ;
2526 
2527 	smc = smc_sk(sock->sk);
2528 	conn = &smc->conn;
2529 	lock_sock(&smc->sk);
2530 	if (smc->use_fallback) {
2531 		if (!smc->clcsock) {
2532 			release_sock(&smc->sk);
2533 			return -EBADF;
2534 		}
2535 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
2536 		release_sock(&smc->sk);
2537 		return answ;
2538 	}
2539 	switch (cmd) {
2540 	case SIOCINQ: /* same as FIONREAD */
2541 		if (smc->sk.sk_state == SMC_LISTEN) {
2542 			release_sock(&smc->sk);
2543 			return -EINVAL;
2544 		}
2545 		if (smc->sk.sk_state == SMC_INIT ||
2546 		    smc->sk.sk_state == SMC_CLOSED)
2547 			answ = 0;
2548 		else
2549 			answ = atomic_read(&smc->conn.bytes_to_rcv);
2550 		break;
2551 	case SIOCOUTQ:
2552 		/* output queue size (not send + not acked) */
2553 		if (smc->sk.sk_state == SMC_LISTEN) {
2554 			release_sock(&smc->sk);
2555 			return -EINVAL;
2556 		}
2557 		if (smc->sk.sk_state == SMC_INIT ||
2558 		    smc->sk.sk_state == SMC_CLOSED)
2559 			answ = 0;
2560 		else
2561 			answ = smc->conn.sndbuf_desc->len -
2562 					atomic_read(&smc->conn.sndbuf_space);
2563 		break;
2564 	case SIOCOUTQNSD:
2565 		/* output queue size (not send only) */
2566 		if (smc->sk.sk_state == SMC_LISTEN) {
2567 			release_sock(&smc->sk);
2568 			return -EINVAL;
2569 		}
2570 		if (smc->sk.sk_state == SMC_INIT ||
2571 		    smc->sk.sk_state == SMC_CLOSED)
2572 			answ = 0;
2573 		else
2574 			answ = smc_tx_prepared_sends(&smc->conn);
2575 		break;
2576 	case SIOCATMARK:
2577 		if (smc->sk.sk_state == SMC_LISTEN) {
2578 			release_sock(&smc->sk);
2579 			return -EINVAL;
2580 		}
2581 		if (smc->sk.sk_state == SMC_INIT ||
2582 		    smc->sk.sk_state == SMC_CLOSED) {
2583 			answ = 0;
2584 		} else {
2585 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
2586 			smc_curs_copy(&urg, &conn->urg_curs, conn);
2587 			answ = smc_curs_diff(conn->rmb_desc->len,
2588 					     &cons, &urg) == 1;
2589 		}
2590 		break;
2591 	default:
2592 		release_sock(&smc->sk);
2593 		return -ENOIOCTLCMD;
2594 	}
2595 	release_sock(&smc->sk);
2596 
2597 	return put_user(answ, (int __user *)arg);
2598 }
2599 
2600 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
2601 			    int offset, size_t size, int flags)
2602 {
2603 	struct sock *sk = sock->sk;
2604 	struct smc_sock *smc;
2605 	int rc = -EPIPE;
2606 
2607 	smc = smc_sk(sk);
2608 	lock_sock(sk);
2609 	if (sk->sk_state != SMC_ACTIVE) {
2610 		release_sock(sk);
2611 		goto out;
2612 	}
2613 	release_sock(sk);
2614 	if (smc->use_fallback) {
2615 		rc = kernel_sendpage(smc->clcsock, page, offset,
2616 				     size, flags);
2617 	} else {
2618 		SMC_STAT_INC(smc, sendpage_cnt);
2619 		rc = sock_no_sendpage(sock, page, offset, size, flags);
2620 	}
2621 
2622 out:
2623 	return rc;
2624 }
2625 
2626 /* Map the affected portions of the rmbe into an spd, note the number of bytes
2627  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
2628  * updates till whenever a respective page has been fully processed.
2629  * Note that subsequent recv() calls have to wait till all splice() processing
2630  * completed.
2631  */
2632 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
2633 			       struct pipe_inode_info *pipe, size_t len,
2634 			       unsigned int flags)
2635 {
2636 	struct sock *sk = sock->sk;
2637 	struct smc_sock *smc;
2638 	int rc = -ENOTCONN;
2639 
2640 	smc = smc_sk(sk);
2641 	lock_sock(sk);
2642 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2643 		/* socket was connected before, no more data to read */
2644 		rc = 0;
2645 		goto out;
2646 	}
2647 	if (sk->sk_state == SMC_INIT ||
2648 	    sk->sk_state == SMC_LISTEN ||
2649 	    sk->sk_state == SMC_CLOSED)
2650 		goto out;
2651 
2652 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2653 		rc = 0;
2654 		goto out;
2655 	}
2656 
2657 	if (smc->use_fallback) {
2658 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
2659 						    pipe, len, flags);
2660 	} else {
2661 		if (*ppos) {
2662 			rc = -ESPIPE;
2663 			goto out;
2664 		}
2665 		if (flags & SPLICE_F_NONBLOCK)
2666 			flags = MSG_DONTWAIT;
2667 		else
2668 			flags = 0;
2669 		SMC_STAT_INC(smc, splice_cnt);
2670 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
2671 	}
2672 out:
2673 	release_sock(sk);
2674 
2675 	return rc;
2676 }
2677 
2678 /* must look like tcp */
2679 static const struct proto_ops smc_sock_ops = {
2680 	.family		= PF_SMC,
2681 	.owner		= THIS_MODULE,
2682 	.release	= smc_release,
2683 	.bind		= smc_bind,
2684 	.connect	= smc_connect,
2685 	.socketpair	= sock_no_socketpair,
2686 	.accept		= smc_accept,
2687 	.getname	= smc_getname,
2688 	.poll		= smc_poll,
2689 	.ioctl		= smc_ioctl,
2690 	.listen		= smc_listen,
2691 	.shutdown	= smc_shutdown,
2692 	.setsockopt	= smc_setsockopt,
2693 	.getsockopt	= smc_getsockopt,
2694 	.sendmsg	= smc_sendmsg,
2695 	.recvmsg	= smc_recvmsg,
2696 	.mmap		= sock_no_mmap,
2697 	.sendpage	= smc_sendpage,
2698 	.splice_read	= smc_splice_read,
2699 };
2700 
2701 static int smc_create(struct net *net, struct socket *sock, int protocol,
2702 		      int kern)
2703 {
2704 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
2705 	struct smc_sock *smc;
2706 	struct sock *sk;
2707 	int rc;
2708 
2709 	rc = -ESOCKTNOSUPPORT;
2710 	if (sock->type != SOCK_STREAM)
2711 		goto out;
2712 
2713 	rc = -EPROTONOSUPPORT;
2714 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
2715 		goto out;
2716 
2717 	rc = -ENOBUFS;
2718 	sock->ops = &smc_sock_ops;
2719 	sk = smc_sock_alloc(net, sock, protocol);
2720 	if (!sk)
2721 		goto out;
2722 
2723 	/* create internal TCP socket for CLC handshake and fallback */
2724 	smc = smc_sk(sk);
2725 	smc->use_fallback = false; /* assume rdma capability first */
2726 	smc->fallback_rsn = 0;
2727 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
2728 			      &smc->clcsock);
2729 	if (rc) {
2730 		sk_common_release(sk);
2731 		goto out;
2732 	}
2733 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
2734 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
2735 
2736 out:
2737 	return rc;
2738 }
2739 
2740 static const struct net_proto_family smc_sock_family_ops = {
2741 	.family	= PF_SMC,
2742 	.owner	= THIS_MODULE,
2743 	.create	= smc_create,
2744 };
2745 
2746 unsigned int smc_net_id;
2747 
2748 static __net_init int smc_net_init(struct net *net)
2749 {
2750 	return smc_pnet_net_init(net);
2751 }
2752 
2753 static void __net_exit smc_net_exit(struct net *net)
2754 {
2755 	smc_pnet_net_exit(net);
2756 }
2757 
2758 static __net_init int smc_net_stat_init(struct net *net)
2759 {
2760 	return smc_stats_init(net);
2761 }
2762 
2763 static void __net_exit smc_net_stat_exit(struct net *net)
2764 {
2765 	smc_stats_exit(net);
2766 }
2767 
2768 static struct pernet_operations smc_net_ops = {
2769 	.init = smc_net_init,
2770 	.exit = smc_net_exit,
2771 	.id   = &smc_net_id,
2772 	.size = sizeof(struct smc_net),
2773 };
2774 
2775 static struct pernet_operations smc_net_stat_ops = {
2776 	.init = smc_net_stat_init,
2777 	.exit = smc_net_stat_exit,
2778 };
2779 
2780 static int __init smc_init(void)
2781 {
2782 	int rc;
2783 
2784 	rc = register_pernet_subsys(&smc_net_ops);
2785 	if (rc)
2786 		return rc;
2787 
2788 	rc = register_pernet_subsys(&smc_net_stat_ops);
2789 	if (rc)
2790 		return rc;
2791 
2792 	smc_ism_init();
2793 	smc_clc_init();
2794 
2795 	rc = smc_nl_init();
2796 	if (rc)
2797 		goto out_pernet_subsys;
2798 
2799 	rc = smc_pnet_init();
2800 	if (rc)
2801 		goto out_nl;
2802 
2803 	rc = -ENOMEM;
2804 	smc_hs_wq = alloc_workqueue("smc_hs_wq", 0, 0);
2805 	if (!smc_hs_wq)
2806 		goto out_pnet;
2807 
2808 	smc_close_wq = alloc_workqueue("smc_close_wq", 0, 0);
2809 	if (!smc_close_wq)
2810 		goto out_alloc_hs_wq;
2811 
2812 	rc = smc_core_init();
2813 	if (rc) {
2814 		pr_err("%s: smc_core_init fails with %d\n", __func__, rc);
2815 		goto out_alloc_wqs;
2816 	}
2817 
2818 	rc = smc_llc_init();
2819 	if (rc) {
2820 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
2821 		goto out_core;
2822 	}
2823 
2824 	rc = smc_cdc_init();
2825 	if (rc) {
2826 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
2827 		goto out_core;
2828 	}
2829 
2830 	rc = proto_register(&smc_proto, 1);
2831 	if (rc) {
2832 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
2833 		goto out_core;
2834 	}
2835 
2836 	rc = proto_register(&smc_proto6, 1);
2837 	if (rc) {
2838 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
2839 		goto out_proto;
2840 	}
2841 
2842 	rc = sock_register(&smc_sock_family_ops);
2843 	if (rc) {
2844 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
2845 		goto out_proto6;
2846 	}
2847 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
2848 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
2849 
2850 	rc = smc_ib_register_client();
2851 	if (rc) {
2852 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
2853 		goto out_sock;
2854 	}
2855 
2856 	static_branch_enable(&tcp_have_smc);
2857 	return 0;
2858 
2859 out_sock:
2860 	sock_unregister(PF_SMC);
2861 out_proto6:
2862 	proto_unregister(&smc_proto6);
2863 out_proto:
2864 	proto_unregister(&smc_proto);
2865 out_core:
2866 	smc_core_exit();
2867 out_alloc_wqs:
2868 	destroy_workqueue(smc_close_wq);
2869 out_alloc_hs_wq:
2870 	destroy_workqueue(smc_hs_wq);
2871 out_pnet:
2872 	smc_pnet_exit();
2873 out_nl:
2874 	smc_nl_exit();
2875 out_pernet_subsys:
2876 	unregister_pernet_subsys(&smc_net_ops);
2877 
2878 	return rc;
2879 }
2880 
2881 static void __exit smc_exit(void)
2882 {
2883 	static_branch_disable(&tcp_have_smc);
2884 	sock_unregister(PF_SMC);
2885 	smc_core_exit();
2886 	smc_ib_unregister_client();
2887 	destroy_workqueue(smc_close_wq);
2888 	destroy_workqueue(smc_hs_wq);
2889 	proto_unregister(&smc_proto6);
2890 	proto_unregister(&smc_proto);
2891 	smc_pnet_exit();
2892 	smc_nl_exit();
2893 	smc_clc_exit();
2894 	unregister_pernet_subsys(&smc_net_stat_ops);
2895 	unregister_pernet_subsys(&smc_net_ops);
2896 	rcu_barrier();
2897 }
2898 
2899 module_init(smc_init);
2900 module_exit(smc_exit);
2901 
2902 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
2903 MODULE_DESCRIPTION("smc socket address family");
2904 MODULE_LICENSE("GPL");
2905 MODULE_ALIAS_NETPROTO(PF_SMC);
2906