xref: /openbmc/linux/net/smc/af_smc.c (revision dc023681)
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 
54 static DEFINE_MUTEX(smc_server_lgr_pending);	/* serialize link group
55 						 * creation on server
56 						 */
57 static DEFINE_MUTEX(smc_client_lgr_pending);	/* serialize link group
58 						 * creation on client
59 						 */
60 
61 struct workqueue_struct	*smc_hs_wq;	/* wq for handshake work */
62 struct workqueue_struct	*smc_close_wq;	/* wq for close work */
63 
64 static void smc_tcp_listen_work(struct work_struct *);
65 static void smc_connect_work(struct work_struct *);
66 
67 static void smc_set_keepalive(struct sock *sk, int val)
68 {
69 	struct smc_sock *smc = smc_sk(sk);
70 
71 	smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
72 }
73 
74 static struct smc_hashinfo smc_v4_hashinfo = {
75 	.lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
76 };
77 
78 static struct smc_hashinfo smc_v6_hashinfo = {
79 	.lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
80 };
81 
82 int smc_hash_sk(struct sock *sk)
83 {
84 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
85 	struct hlist_head *head;
86 
87 	head = &h->ht;
88 
89 	write_lock_bh(&h->lock);
90 	sk_add_node(sk, head);
91 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
92 	write_unlock_bh(&h->lock);
93 
94 	return 0;
95 }
96 EXPORT_SYMBOL_GPL(smc_hash_sk);
97 
98 void smc_unhash_sk(struct sock *sk)
99 {
100 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
101 
102 	write_lock_bh(&h->lock);
103 	if (sk_del_node_init(sk))
104 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
105 	write_unlock_bh(&h->lock);
106 }
107 EXPORT_SYMBOL_GPL(smc_unhash_sk);
108 
109 struct proto smc_proto = {
110 	.name		= "SMC",
111 	.owner		= THIS_MODULE,
112 	.keepalive	= smc_set_keepalive,
113 	.hash		= smc_hash_sk,
114 	.unhash		= smc_unhash_sk,
115 	.obj_size	= sizeof(struct smc_sock),
116 	.h.smc_hash	= &smc_v4_hashinfo,
117 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
118 };
119 EXPORT_SYMBOL_GPL(smc_proto);
120 
121 struct proto smc_proto6 = {
122 	.name		= "SMC6",
123 	.owner		= THIS_MODULE,
124 	.keepalive	= smc_set_keepalive,
125 	.hash		= smc_hash_sk,
126 	.unhash		= smc_unhash_sk,
127 	.obj_size	= sizeof(struct smc_sock),
128 	.h.smc_hash	= &smc_v6_hashinfo,
129 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
130 };
131 EXPORT_SYMBOL_GPL(smc_proto6);
132 
133 static void smc_restore_fallback_changes(struct smc_sock *smc)
134 {
135 	if (smc->clcsock->file) { /* non-accepted sockets have no file yet */
136 		smc->clcsock->file->private_data = smc->sk.sk_socket;
137 		smc->clcsock->file = NULL;
138 	}
139 }
140 
141 static int __smc_release(struct smc_sock *smc)
142 {
143 	struct sock *sk = &smc->sk;
144 	int rc = 0;
145 
146 	if (!smc->use_fallback) {
147 		rc = smc_close_active(smc);
148 		sock_set_flag(sk, SOCK_DEAD);
149 		sk->sk_shutdown |= SHUTDOWN_MASK;
150 	} else {
151 		if (sk->sk_state != SMC_LISTEN && sk->sk_state != SMC_INIT)
152 			sock_put(sk); /* passive closing */
153 		if (sk->sk_state == SMC_LISTEN) {
154 			/* wake up clcsock accept */
155 			rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
156 		}
157 		sk->sk_state = SMC_CLOSED;
158 		sk->sk_state_change(sk);
159 		smc_restore_fallback_changes(smc);
160 	}
161 
162 	sk->sk_prot->unhash(sk);
163 
164 	if (sk->sk_state == SMC_CLOSED) {
165 		if (smc->clcsock) {
166 			release_sock(sk);
167 			smc_clcsock_release(smc);
168 			lock_sock(sk);
169 		}
170 		if (!smc->use_fallback)
171 			smc_conn_free(&smc->conn);
172 	}
173 
174 	return rc;
175 }
176 
177 static int smc_release(struct socket *sock)
178 {
179 	struct sock *sk = sock->sk;
180 	struct smc_sock *smc;
181 	int rc = 0;
182 
183 	if (!sk)
184 		goto out;
185 
186 	sock_hold(sk); /* sock_put below */
187 	smc = smc_sk(sk);
188 
189 	/* cleanup for a dangling non-blocking connect */
190 	if (smc->connect_nonblock && sk->sk_state == SMC_INIT)
191 		tcp_abort(smc->clcsock->sk, ECONNABORTED);
192 	flush_work(&smc->connect_work);
193 
194 	if (sk->sk_state == SMC_LISTEN)
195 		/* smc_close_non_accepted() is called and acquires
196 		 * sock lock for child sockets again
197 		 */
198 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
199 	else
200 		lock_sock(sk);
201 
202 	rc = __smc_release(smc);
203 
204 	/* detach socket */
205 	sock_orphan(sk);
206 	sock->sk = NULL;
207 	release_sock(sk);
208 
209 	sock_put(sk); /* sock_hold above */
210 	sock_put(sk); /* final sock_put */
211 out:
212 	return rc;
213 }
214 
215 static void smc_destruct(struct sock *sk)
216 {
217 	if (sk->sk_state != SMC_CLOSED)
218 		return;
219 	if (!sock_flag(sk, SOCK_DEAD))
220 		return;
221 
222 	sk_refcnt_debug_dec(sk);
223 }
224 
225 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
226 				   int protocol)
227 {
228 	struct smc_sock *smc;
229 	struct proto *prot;
230 	struct sock *sk;
231 
232 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
233 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
234 	if (!sk)
235 		return NULL;
236 
237 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
238 	sk->sk_state = SMC_INIT;
239 	sk->sk_destruct = smc_destruct;
240 	sk->sk_protocol = protocol;
241 	smc = smc_sk(sk);
242 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
243 	INIT_WORK(&smc->connect_work, smc_connect_work);
244 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
245 	INIT_LIST_HEAD(&smc->accept_q);
246 	spin_lock_init(&smc->accept_q_lock);
247 	spin_lock_init(&smc->conn.send_lock);
248 	sk->sk_prot->hash(sk);
249 	sk_refcnt_debug_inc(sk);
250 	mutex_init(&smc->clcsock_release_lock);
251 
252 	return sk;
253 }
254 
255 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
256 		    int addr_len)
257 {
258 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
259 	struct sock *sk = sock->sk;
260 	struct smc_sock *smc;
261 	int rc;
262 
263 	smc = smc_sk(sk);
264 
265 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
266 	rc = -EINVAL;
267 	if (addr_len < sizeof(struct sockaddr_in))
268 		goto out;
269 
270 	rc = -EAFNOSUPPORT;
271 	if (addr->sin_family != AF_INET &&
272 	    addr->sin_family != AF_INET6 &&
273 	    addr->sin_family != AF_UNSPEC)
274 		goto out;
275 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
276 	if (addr->sin_family == AF_UNSPEC &&
277 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
278 		goto out;
279 
280 	lock_sock(sk);
281 
282 	/* Check if socket is already active */
283 	rc = -EINVAL;
284 	if (sk->sk_state != SMC_INIT || smc->connect_nonblock)
285 		goto out_rel;
286 
287 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
288 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
289 
290 out_rel:
291 	release_sock(sk);
292 out:
293 	return rc;
294 }
295 
296 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
297 				   unsigned long mask)
298 {
299 	/* options we don't get control via setsockopt for */
300 	nsk->sk_type = osk->sk_type;
301 	nsk->sk_sndbuf = osk->sk_sndbuf;
302 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
303 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
304 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
305 	nsk->sk_mark = osk->sk_mark;
306 	nsk->sk_priority = osk->sk_priority;
307 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
308 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
309 	nsk->sk_err = osk->sk_err;
310 
311 	nsk->sk_flags &= ~mask;
312 	nsk->sk_flags |= osk->sk_flags & mask;
313 }
314 
315 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
316 			     (1UL << SOCK_KEEPOPEN) | \
317 			     (1UL << SOCK_LINGER) | \
318 			     (1UL << SOCK_BROADCAST) | \
319 			     (1UL << SOCK_TIMESTAMP) | \
320 			     (1UL << SOCK_DBG) | \
321 			     (1UL << SOCK_RCVTSTAMP) | \
322 			     (1UL << SOCK_RCVTSTAMPNS) | \
323 			     (1UL << SOCK_LOCALROUTE) | \
324 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
325 			     (1UL << SOCK_RXQ_OVFL) | \
326 			     (1UL << SOCK_WIFI_STATUS) | \
327 			     (1UL << SOCK_NOFCS) | \
328 			     (1UL << SOCK_FILTER_LOCKED) | \
329 			     (1UL << SOCK_TSTAMP_NEW))
330 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
331  * clc socket (since smc is not called for these options from net/core)
332  */
333 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
334 {
335 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
336 }
337 
338 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
339 			     (1UL << SOCK_KEEPOPEN) | \
340 			     (1UL << SOCK_LINGER) | \
341 			     (1UL << SOCK_DBG))
342 /* copy only settings and flags relevant for smc from clc to smc socket */
343 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
344 {
345 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
346 }
347 
348 /* register the new rmb on all links */
349 static int smcr_lgr_reg_rmbs(struct smc_link *link,
350 			     struct smc_buf_desc *rmb_desc)
351 {
352 	struct smc_link_group *lgr = link->lgr;
353 	int i, rc = 0;
354 
355 	rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
356 	if (rc)
357 		return rc;
358 	/* protect against parallel smc_llc_cli_rkey_exchange() and
359 	 * parallel smcr_link_reg_rmb()
360 	 */
361 	mutex_lock(&lgr->llc_conf_mutex);
362 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
363 		if (!smc_link_active(&lgr->lnk[i]))
364 			continue;
365 		rc = smcr_link_reg_rmb(&lgr->lnk[i], rmb_desc);
366 		if (rc)
367 			goto out;
368 	}
369 
370 	/* exchange confirm_rkey msg with peer */
371 	rc = smc_llc_do_confirm_rkey(link, rmb_desc);
372 	if (rc) {
373 		rc = -EFAULT;
374 		goto out;
375 	}
376 	rmb_desc->is_conf_rkey = true;
377 out:
378 	mutex_unlock(&lgr->llc_conf_mutex);
379 	smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
380 	return rc;
381 }
382 
383 static int smcr_clnt_conf_first_link(struct smc_sock *smc)
384 {
385 	struct smc_link *link = smc->conn.lnk;
386 	struct smc_llc_qentry *qentry;
387 	int rc;
388 
389 	/* receive CONFIRM LINK request from server over RoCE fabric */
390 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
391 			      SMC_LLC_CONFIRM_LINK);
392 	if (!qentry) {
393 		struct smc_clc_msg_decline dclc;
394 
395 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
396 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
397 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
398 	}
399 	smc_llc_save_peer_uid(qentry);
400 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_REQ);
401 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
402 	if (rc)
403 		return SMC_CLC_DECL_RMBE_EC;
404 
405 	rc = smc_ib_modify_qp_rts(link);
406 	if (rc)
407 		return SMC_CLC_DECL_ERR_RDYLNK;
408 
409 	smc_wr_remember_qp_attr(link);
410 
411 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc))
412 		return SMC_CLC_DECL_ERR_REGRMB;
413 
414 	/* confirm_rkey is implicit on 1st contact */
415 	smc->conn.rmb_desc->is_conf_rkey = true;
416 
417 	/* send CONFIRM LINK response over RoCE fabric */
418 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
419 	if (rc < 0)
420 		return SMC_CLC_DECL_TIMEOUT_CL;
421 
422 	smc_llc_link_active(link);
423 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
424 
425 	/* optional 2nd link, receive ADD LINK request from server */
426 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
427 			      SMC_LLC_ADD_LINK);
428 	if (!qentry) {
429 		struct smc_clc_msg_decline dclc;
430 
431 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
432 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
433 		if (rc == -EAGAIN)
434 			rc = 0; /* no DECLINE received, go with one link */
435 		return rc;
436 	}
437 	smc_llc_flow_qentry_clr(&link->lgr->llc_flow_lcl);
438 	smc_llc_cli_add_link(link, qentry);
439 	return 0;
440 }
441 
442 static void smcr_conn_save_peer_info(struct smc_sock *smc,
443 				     struct smc_clc_msg_accept_confirm *clc)
444 {
445 	int bufsize = smc_uncompress_bufsize(clc->r0.rmbe_size);
446 
447 	smc->conn.peer_rmbe_idx = clc->r0.rmbe_idx;
448 	smc->conn.local_tx_ctrl.token = ntohl(clc->r0.rmbe_alert_token);
449 	smc->conn.peer_rmbe_size = bufsize;
450 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
451 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
452 }
453 
454 static bool smc_isascii(char *hostname)
455 {
456 	int i;
457 
458 	for (i = 0; i < SMC_MAX_HOSTNAME_LEN; i++)
459 		if (!isascii(hostname[i]))
460 			return false;
461 	return true;
462 }
463 
464 static void smcd_conn_save_peer_info(struct smc_sock *smc,
465 				     struct smc_clc_msg_accept_confirm *clc)
466 {
467 	int bufsize = smc_uncompress_bufsize(clc->d0.dmbe_size);
468 
469 	smc->conn.peer_rmbe_idx = clc->d0.dmbe_idx;
470 	smc->conn.peer_token = clc->d0.token;
471 	/* msg header takes up space in the buffer */
472 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
473 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
474 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
475 	if (clc->hdr.version > SMC_V1 &&
476 	    (clc->hdr.typev2 & SMC_FIRST_CONTACT_MASK)) {
477 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
478 			(struct smc_clc_msg_accept_confirm_v2 *)clc;
479 		struct smc_clc_first_contact_ext *fce =
480 			(struct smc_clc_first_contact_ext *)
481 				(((u8 *)clc_v2) + sizeof(*clc_v2));
482 
483 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->eid,
484 		       SMC_MAX_EID_LEN);
485 		smc->conn.lgr->peer_os = fce->os_type;
486 		smc->conn.lgr->peer_smc_release = fce->release;
487 		if (smc_isascii(fce->hostname))
488 			memcpy(smc->conn.lgr->peer_hostname, fce->hostname,
489 			       SMC_MAX_HOSTNAME_LEN);
490 	}
491 }
492 
493 static void smc_conn_save_peer_info(struct smc_sock *smc,
494 				    struct smc_clc_msg_accept_confirm *clc)
495 {
496 	if (smc->conn.lgr->is_smcd)
497 		smcd_conn_save_peer_info(smc, clc);
498 	else
499 		smcr_conn_save_peer_info(smc, clc);
500 }
501 
502 static void smc_link_save_peer_info(struct smc_link *link,
503 				    struct smc_clc_msg_accept_confirm *clc)
504 {
505 	link->peer_qpn = ntoh24(clc->r0.qpn);
506 	memcpy(link->peer_gid, clc->r0.lcl.gid, SMC_GID_SIZE);
507 	memcpy(link->peer_mac, clc->r0.lcl.mac, sizeof(link->peer_mac));
508 	link->peer_psn = ntoh24(clc->r0.psn);
509 	link->peer_mtu = clc->r0.qp_mtu;
510 }
511 
512 static void smc_stat_inc_fback_rsn_cnt(struct smc_sock *smc,
513 				       struct smc_stats_fback *fback_arr)
514 {
515 	int cnt;
516 
517 	for (cnt = 0; cnt < SMC_MAX_FBACK_RSN_CNT; cnt++) {
518 		if (fback_arr[cnt].fback_code == smc->fallback_rsn) {
519 			fback_arr[cnt].count++;
520 			break;
521 		}
522 		if (!fback_arr[cnt].fback_code) {
523 			fback_arr[cnt].fback_code = smc->fallback_rsn;
524 			fback_arr[cnt].count++;
525 			break;
526 		}
527 	}
528 }
529 
530 static void smc_stat_fallback(struct smc_sock *smc)
531 {
532 	struct net *net = sock_net(&smc->sk);
533 
534 	mutex_lock(&net->smc.mutex_fback_rsn);
535 	if (smc->listen_smc) {
536 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->srv);
537 		net->smc.fback_rsn->srv_fback_cnt++;
538 	} else {
539 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->clnt);
540 		net->smc.fback_rsn->clnt_fback_cnt++;
541 	}
542 	mutex_unlock(&net->smc.mutex_fback_rsn);
543 }
544 
545 static void smc_switch_to_fallback(struct smc_sock *smc, int reason_code)
546 {
547 	smc->use_fallback = true;
548 	smc->fallback_rsn = reason_code;
549 	smc_stat_fallback(smc);
550 	if (smc->sk.sk_socket && smc->sk.sk_socket->file) {
551 		smc->clcsock->file = smc->sk.sk_socket->file;
552 		smc->clcsock->file->private_data = smc->clcsock;
553 		smc->clcsock->wq.fasync_list =
554 			smc->sk.sk_socket->wq.fasync_list;
555 	}
556 }
557 
558 /* fall back during connect */
559 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
560 {
561 	smc_switch_to_fallback(smc, reason_code);
562 	smc_copy_sock_settings_to_clc(smc);
563 	smc->connect_nonblock = 0;
564 	if (smc->sk.sk_state == SMC_INIT)
565 		smc->sk.sk_state = SMC_ACTIVE;
566 	return 0;
567 }
568 
569 /* decline and fall back during connect */
570 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code,
571 					u8 version)
572 {
573 	struct net *net = sock_net(&smc->sk);
574 	int rc;
575 
576 	if (reason_code < 0) { /* error, fallback is not possible */
577 		this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
578 		if (smc->sk.sk_state == SMC_INIT)
579 			sock_put(&smc->sk); /* passive closing */
580 		return reason_code;
581 	}
582 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
583 		rc = smc_clc_send_decline(smc, reason_code, version);
584 		if (rc < 0) {
585 			this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
586 			if (smc->sk.sk_state == SMC_INIT)
587 				sock_put(&smc->sk); /* passive closing */
588 			return rc;
589 		}
590 	}
591 	return smc_connect_fallback(smc, reason_code);
592 }
593 
594 static void smc_conn_abort(struct smc_sock *smc, int local_first)
595 {
596 	if (local_first)
597 		smc_lgr_cleanup_early(&smc->conn);
598 	else
599 		smc_conn_free(&smc->conn);
600 }
601 
602 /* check if there is a rdma device available for this connection. */
603 /* called for connect and listen */
604 static int smc_find_rdma_device(struct smc_sock *smc, struct smc_init_info *ini)
605 {
606 	/* PNET table look up: search active ib_device and port
607 	 * within same PNETID that also contains the ethernet device
608 	 * used for the internal TCP socket
609 	 */
610 	smc_pnet_find_roce_resource(smc->clcsock->sk, ini);
611 	if (!ini->ib_dev)
612 		return SMC_CLC_DECL_NOSMCRDEV;
613 	return 0;
614 }
615 
616 /* check if there is an ISM device available for this connection. */
617 /* called for connect and listen */
618 static int smc_find_ism_device(struct smc_sock *smc, struct smc_init_info *ini)
619 {
620 	/* Find ISM device with same PNETID as connecting interface  */
621 	smc_pnet_find_ism_resource(smc->clcsock->sk, ini);
622 	if (!ini->ism_dev[0])
623 		return SMC_CLC_DECL_NOSMCDDEV;
624 	else
625 		ini->ism_chid[0] = smc_ism_get_chid(ini->ism_dev[0]);
626 	return 0;
627 }
628 
629 /* is chid unique for the ism devices that are already determined? */
630 static bool smc_find_ism_v2_is_unique_chid(u16 chid, struct smc_init_info *ini,
631 					   int cnt)
632 {
633 	int i = (!ini->ism_dev[0]) ? 1 : 0;
634 
635 	for (; i < cnt; i++)
636 		if (ini->ism_chid[i] == chid)
637 			return false;
638 	return true;
639 }
640 
641 /* determine possible V2 ISM devices (either without PNETID or with PNETID plus
642  * PNETID matching net_device)
643  */
644 static int smc_find_ism_v2_device_clnt(struct smc_sock *smc,
645 				       struct smc_init_info *ini)
646 {
647 	int rc = SMC_CLC_DECL_NOSMCDDEV;
648 	struct smcd_dev *smcd;
649 	int i = 1;
650 	u16 chid;
651 
652 	if (smcd_indicated(ini->smc_type_v1))
653 		rc = 0;		/* already initialized for V1 */
654 	mutex_lock(&smcd_dev_list.mutex);
655 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
656 		if (smcd->going_away || smcd == ini->ism_dev[0])
657 			continue;
658 		chid = smc_ism_get_chid(smcd);
659 		if (!smc_find_ism_v2_is_unique_chid(chid, ini, i))
660 			continue;
661 		if (!smc_pnet_is_pnetid_set(smcd->pnetid) ||
662 		    smc_pnet_is_ndev_pnetid(sock_net(&smc->sk), smcd->pnetid)) {
663 			ini->ism_dev[i] = smcd;
664 			ini->ism_chid[i] = chid;
665 			ini->is_smcd = true;
666 			rc = 0;
667 			i++;
668 			if (i > SMC_MAX_ISM_DEVS)
669 				break;
670 		}
671 	}
672 	mutex_unlock(&smcd_dev_list.mutex);
673 	ini->ism_offered_cnt = i - 1;
674 	if (!ini->ism_dev[0] && !ini->ism_dev[1])
675 		ini->smcd_version = 0;
676 
677 	return rc;
678 }
679 
680 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
681 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
682 				      struct smc_init_info *ini)
683 {
684 	if (ini->vlan_id && smc_ism_get_vlan(ini->ism_dev[0], ini->vlan_id))
685 		return SMC_CLC_DECL_ISMVLANERR;
686 	return 0;
687 }
688 
689 static int smc_find_proposal_devices(struct smc_sock *smc,
690 				     struct smc_init_info *ini)
691 {
692 	int rc = 0;
693 
694 	/* check if there is an ism device available */
695 	if (ini->smcd_version & SMC_V1) {
696 		if (smc_find_ism_device(smc, ini) ||
697 		    smc_connect_ism_vlan_setup(smc, ini)) {
698 			if (ini->smc_type_v1 == SMC_TYPE_B)
699 				ini->smc_type_v1 = SMC_TYPE_R;
700 			else
701 				ini->smc_type_v1 = SMC_TYPE_N;
702 		} /* else ISM V1 is supported for this connection */
703 		if (smc_find_rdma_device(smc, ini)) {
704 			if (ini->smc_type_v1 == SMC_TYPE_B)
705 				ini->smc_type_v1 = SMC_TYPE_D;
706 			else
707 				ini->smc_type_v1 = SMC_TYPE_N;
708 		} /* else RDMA is supported for this connection */
709 	}
710 	if (smc_ism_is_v2_capable() && smc_find_ism_v2_device_clnt(smc, ini))
711 		ini->smc_type_v2 = SMC_TYPE_N;
712 
713 	/* if neither ISM nor RDMA are supported, fallback */
714 	if (!smcr_indicated(ini->smc_type_v1) &&
715 	    ini->smc_type_v1 == SMC_TYPE_N && ini->smc_type_v2 == SMC_TYPE_N)
716 		rc = SMC_CLC_DECL_NOSMCDEV;
717 
718 	return rc;
719 }
720 
721 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
722  * used, the VLAN ID will be registered again during the connection setup.
723  */
724 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc,
725 					struct smc_init_info *ini)
726 {
727 	if (!smcd_indicated(ini->smc_type_v1))
728 		return 0;
729 	if (ini->vlan_id && smc_ism_put_vlan(ini->ism_dev[0], ini->vlan_id))
730 		return SMC_CLC_DECL_CNFERR;
731 	return 0;
732 }
733 
734 #define SMC_CLC_MAX_ACCEPT_LEN \
735 	(sizeof(struct smc_clc_msg_accept_confirm_v2) + \
736 	 sizeof(struct smc_clc_first_contact_ext) + \
737 	 sizeof(struct smc_clc_msg_trail))
738 
739 /* CLC handshake during connect */
740 static int smc_connect_clc(struct smc_sock *smc,
741 			   struct smc_clc_msg_accept_confirm_v2 *aclc2,
742 			   struct smc_init_info *ini)
743 {
744 	int rc = 0;
745 
746 	/* do inband token exchange */
747 	rc = smc_clc_send_proposal(smc, ini);
748 	if (rc)
749 		return rc;
750 	/* receive SMC Accept CLC message */
751 	return smc_clc_wait_msg(smc, aclc2, SMC_CLC_MAX_ACCEPT_LEN,
752 				SMC_CLC_ACCEPT, CLC_WAIT_TIME);
753 }
754 
755 /* setup for RDMA connection of client */
756 static int smc_connect_rdma(struct smc_sock *smc,
757 			    struct smc_clc_msg_accept_confirm *aclc,
758 			    struct smc_init_info *ini)
759 {
760 	int i, reason_code = 0;
761 	struct smc_link *link;
762 
763 	ini->is_smcd = false;
764 	ini->ib_lcl = &aclc->r0.lcl;
765 	ini->ib_clcqpn = ntoh24(aclc->r0.qpn);
766 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
767 
768 	mutex_lock(&smc_client_lgr_pending);
769 	reason_code = smc_conn_create(smc, ini);
770 	if (reason_code) {
771 		mutex_unlock(&smc_client_lgr_pending);
772 		return reason_code;
773 	}
774 
775 	smc_conn_save_peer_info(smc, aclc);
776 
777 	if (ini->first_contact_local) {
778 		link = smc->conn.lnk;
779 	} else {
780 		/* set link that was assigned by server */
781 		link = NULL;
782 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
783 			struct smc_link *l = &smc->conn.lgr->lnk[i];
784 
785 			if (l->peer_qpn == ntoh24(aclc->r0.qpn) &&
786 			    !memcmp(l->peer_gid, &aclc->r0.lcl.gid,
787 				    SMC_GID_SIZE) &&
788 			    !memcmp(l->peer_mac, &aclc->r0.lcl.mac,
789 				    sizeof(l->peer_mac))) {
790 				link = l;
791 				break;
792 			}
793 		}
794 		if (!link) {
795 			reason_code = SMC_CLC_DECL_NOSRVLINK;
796 			goto connect_abort;
797 		}
798 		smc_switch_link_and_count(&smc->conn, link);
799 	}
800 
801 	/* create send buffer and rmb */
802 	if (smc_buf_create(smc, false)) {
803 		reason_code = SMC_CLC_DECL_MEM;
804 		goto connect_abort;
805 	}
806 
807 	if (ini->first_contact_local)
808 		smc_link_save_peer_info(link, aclc);
809 
810 	if (smc_rmb_rtoken_handling(&smc->conn, link, aclc)) {
811 		reason_code = SMC_CLC_DECL_ERR_RTOK;
812 		goto connect_abort;
813 	}
814 
815 	smc_close_init(smc);
816 	smc_rx_init(smc);
817 
818 	if (ini->first_contact_local) {
819 		if (smc_ib_ready_link(link)) {
820 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
821 			goto connect_abort;
822 		}
823 	} else {
824 		if (smcr_lgr_reg_rmbs(link, smc->conn.rmb_desc)) {
825 			reason_code = SMC_CLC_DECL_ERR_REGRMB;
826 			goto connect_abort;
827 		}
828 	}
829 	smc_rmb_sync_sg_for_device(&smc->conn);
830 
831 	reason_code = smc_clc_send_confirm(smc, ini->first_contact_local,
832 					   SMC_V1);
833 	if (reason_code)
834 		goto connect_abort;
835 
836 	smc_tx_init(smc);
837 
838 	if (ini->first_contact_local) {
839 		/* QP confirmation over RoCE fabric */
840 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
841 		reason_code = smcr_clnt_conf_first_link(smc);
842 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
843 		if (reason_code)
844 			goto connect_abort;
845 	}
846 	mutex_unlock(&smc_client_lgr_pending);
847 
848 	smc_copy_sock_settings_to_clc(smc);
849 	smc->connect_nonblock = 0;
850 	if (smc->sk.sk_state == SMC_INIT)
851 		smc->sk.sk_state = SMC_ACTIVE;
852 
853 	return 0;
854 connect_abort:
855 	smc_conn_abort(smc, ini->first_contact_local);
856 	mutex_unlock(&smc_client_lgr_pending);
857 	smc->connect_nonblock = 0;
858 
859 	return reason_code;
860 }
861 
862 /* The server has chosen one of the proposed ISM devices for the communication.
863  * Determine from the CHID of the received CLC ACCEPT the ISM device chosen.
864  */
865 static int
866 smc_v2_determine_accepted_chid(struct smc_clc_msg_accept_confirm_v2 *aclc,
867 			       struct smc_init_info *ini)
868 {
869 	int i;
870 
871 	for (i = 0; i < ini->ism_offered_cnt + 1; i++) {
872 		if (ini->ism_chid[i] == ntohs(aclc->chid)) {
873 			ini->ism_selected = i;
874 			return 0;
875 		}
876 	}
877 
878 	return -EPROTO;
879 }
880 
881 /* setup for ISM connection of client */
882 static int smc_connect_ism(struct smc_sock *smc,
883 			   struct smc_clc_msg_accept_confirm *aclc,
884 			   struct smc_init_info *ini)
885 {
886 	int rc = 0;
887 
888 	ini->is_smcd = true;
889 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
890 
891 	if (aclc->hdr.version == SMC_V2) {
892 		struct smc_clc_msg_accept_confirm_v2 *aclc_v2 =
893 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
894 
895 		rc = smc_v2_determine_accepted_chid(aclc_v2, ini);
896 		if (rc)
897 			return rc;
898 	}
899 	ini->ism_peer_gid[ini->ism_selected] = aclc->d0.gid;
900 
901 	/* there is only one lgr role for SMC-D; use server lock */
902 	mutex_lock(&smc_server_lgr_pending);
903 	rc = smc_conn_create(smc, ini);
904 	if (rc) {
905 		mutex_unlock(&smc_server_lgr_pending);
906 		return rc;
907 	}
908 
909 	/* Create send and receive buffers */
910 	rc = smc_buf_create(smc, true);
911 	if (rc) {
912 		rc = (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB : SMC_CLC_DECL_MEM;
913 		goto connect_abort;
914 	}
915 
916 	smc_conn_save_peer_info(smc, aclc);
917 	smc_close_init(smc);
918 	smc_rx_init(smc);
919 	smc_tx_init(smc);
920 
921 	rc = smc_clc_send_confirm(smc, ini->first_contact_local,
922 				  aclc->hdr.version);
923 	if (rc)
924 		goto connect_abort;
925 	mutex_unlock(&smc_server_lgr_pending);
926 
927 	smc_copy_sock_settings_to_clc(smc);
928 	smc->connect_nonblock = 0;
929 	if (smc->sk.sk_state == SMC_INIT)
930 		smc->sk.sk_state = SMC_ACTIVE;
931 
932 	return 0;
933 connect_abort:
934 	smc_conn_abort(smc, ini->first_contact_local);
935 	mutex_unlock(&smc_server_lgr_pending);
936 	smc->connect_nonblock = 0;
937 
938 	return rc;
939 }
940 
941 /* check if received accept type and version matches a proposed one */
942 static int smc_connect_check_aclc(struct smc_init_info *ini,
943 				  struct smc_clc_msg_accept_confirm *aclc)
944 {
945 	if ((aclc->hdr.typev1 == SMC_TYPE_R &&
946 	     !smcr_indicated(ini->smc_type_v1)) ||
947 	    (aclc->hdr.typev1 == SMC_TYPE_D &&
948 	     ((!smcd_indicated(ini->smc_type_v1) &&
949 	       !smcd_indicated(ini->smc_type_v2)) ||
950 	      (aclc->hdr.version == SMC_V1 &&
951 	       !smcd_indicated(ini->smc_type_v1)) ||
952 	      (aclc->hdr.version == SMC_V2 &&
953 	       !smcd_indicated(ini->smc_type_v2)))))
954 		return SMC_CLC_DECL_MODEUNSUPP;
955 
956 	return 0;
957 }
958 
959 /* perform steps before actually connecting */
960 static int __smc_connect(struct smc_sock *smc)
961 {
962 	u8 version = smc_ism_is_v2_capable() ? SMC_V2 : SMC_V1;
963 	struct smc_clc_msg_accept_confirm_v2 *aclc2;
964 	struct smc_clc_msg_accept_confirm *aclc;
965 	struct smc_init_info *ini = NULL;
966 	u8 *buf = NULL;
967 	int rc = 0;
968 
969 	if (smc->use_fallback)
970 		return smc_connect_fallback(smc, smc->fallback_rsn);
971 
972 	/* if peer has not signalled SMC-capability, fall back */
973 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
974 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
975 
976 	/* IPSec connections opt out of SMC optimizations */
977 	if (using_ipsec(smc))
978 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC,
979 						    version);
980 
981 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
982 	if (!ini)
983 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_MEM,
984 						    version);
985 
986 	ini->smcd_version = SMC_V1;
987 	ini->smcd_version |= smc_ism_is_v2_capable() ? SMC_V2 : 0;
988 	ini->smc_type_v1 = SMC_TYPE_B;
989 	ini->smc_type_v2 = smc_ism_is_v2_capable() ? SMC_TYPE_D : SMC_TYPE_N;
990 
991 	/* get vlan id from IP device */
992 	if (smc_vlan_by_tcpsk(smc->clcsock, ini)) {
993 		ini->smcd_version &= ~SMC_V1;
994 		ini->smc_type_v1 = SMC_TYPE_N;
995 		if (!ini->smcd_version) {
996 			rc = SMC_CLC_DECL_GETVLANERR;
997 			goto fallback;
998 		}
999 	}
1000 
1001 	rc = smc_find_proposal_devices(smc, ini);
1002 	if (rc)
1003 		goto fallback;
1004 
1005 	buf = kzalloc(SMC_CLC_MAX_ACCEPT_LEN, GFP_KERNEL);
1006 	if (!buf) {
1007 		rc = SMC_CLC_DECL_MEM;
1008 		goto fallback;
1009 	}
1010 	aclc2 = (struct smc_clc_msg_accept_confirm_v2 *)buf;
1011 	aclc = (struct smc_clc_msg_accept_confirm *)aclc2;
1012 
1013 	/* perform CLC handshake */
1014 	rc = smc_connect_clc(smc, aclc2, ini);
1015 	if (rc)
1016 		goto vlan_cleanup;
1017 
1018 	/* check if smc modes and versions of CLC proposal and accept match */
1019 	rc = smc_connect_check_aclc(ini, aclc);
1020 	version = aclc->hdr.version == SMC_V1 ? SMC_V1 : SMC_V2;
1021 	ini->smcd_version = version;
1022 	if (rc)
1023 		goto vlan_cleanup;
1024 
1025 	/* depending on previous steps, connect using rdma or ism */
1026 	if (aclc->hdr.typev1 == SMC_TYPE_R)
1027 		rc = smc_connect_rdma(smc, aclc, ini);
1028 	else if (aclc->hdr.typev1 == SMC_TYPE_D)
1029 		rc = smc_connect_ism(smc, aclc, ini);
1030 	if (rc)
1031 		goto vlan_cleanup;
1032 
1033 	SMC_STAT_CLNT_SUCC_INC(sock_net(smc->clcsock->sk), aclc);
1034 	smc_connect_ism_vlan_cleanup(smc, ini);
1035 	kfree(buf);
1036 	kfree(ini);
1037 	return 0;
1038 
1039 vlan_cleanup:
1040 	smc_connect_ism_vlan_cleanup(smc, ini);
1041 	kfree(buf);
1042 fallback:
1043 	kfree(ini);
1044 	return smc_connect_decline_fallback(smc, rc, version);
1045 }
1046 
1047 static void smc_connect_work(struct work_struct *work)
1048 {
1049 	struct smc_sock *smc = container_of(work, struct smc_sock,
1050 					    connect_work);
1051 	long timeo = smc->sk.sk_sndtimeo;
1052 	int rc = 0;
1053 
1054 	if (!timeo)
1055 		timeo = MAX_SCHEDULE_TIMEOUT;
1056 	lock_sock(smc->clcsock->sk);
1057 	if (smc->clcsock->sk->sk_err) {
1058 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
1059 	} else if ((1 << smc->clcsock->sk->sk_state) &
1060 					(TCPF_SYN_SENT | TCP_SYN_RECV)) {
1061 		rc = sk_stream_wait_connect(smc->clcsock->sk, &timeo);
1062 		if ((rc == -EPIPE) &&
1063 		    ((1 << smc->clcsock->sk->sk_state) &
1064 					(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))
1065 			rc = 0;
1066 	}
1067 	release_sock(smc->clcsock->sk);
1068 	lock_sock(&smc->sk);
1069 	if (rc != 0 || smc->sk.sk_err) {
1070 		smc->sk.sk_state = SMC_CLOSED;
1071 		if (rc == -EPIPE || rc == -EAGAIN)
1072 			smc->sk.sk_err = EPIPE;
1073 		else if (signal_pending(current))
1074 			smc->sk.sk_err = -sock_intr_errno(timeo);
1075 		sock_put(&smc->sk); /* passive closing */
1076 		goto out;
1077 	}
1078 
1079 	rc = __smc_connect(smc);
1080 	if (rc < 0)
1081 		smc->sk.sk_err = -rc;
1082 
1083 out:
1084 	if (!sock_flag(&smc->sk, SOCK_DEAD)) {
1085 		if (smc->sk.sk_err) {
1086 			smc->sk.sk_state_change(&smc->sk);
1087 		} else { /* allow polling before and after fallback decision */
1088 			smc->clcsock->sk->sk_write_space(smc->clcsock->sk);
1089 			smc->sk.sk_write_space(&smc->sk);
1090 		}
1091 	}
1092 	release_sock(&smc->sk);
1093 }
1094 
1095 static int smc_connect(struct socket *sock, struct sockaddr *addr,
1096 		       int alen, int flags)
1097 {
1098 	struct sock *sk = sock->sk;
1099 	struct smc_sock *smc;
1100 	int rc = -EINVAL;
1101 
1102 	smc = smc_sk(sk);
1103 
1104 	/* separate smc parameter checking to be safe */
1105 	if (alen < sizeof(addr->sa_family))
1106 		goto out_err;
1107 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
1108 		goto out_err;
1109 
1110 	lock_sock(sk);
1111 	switch (sk->sk_state) {
1112 	default:
1113 		goto out;
1114 	case SMC_ACTIVE:
1115 		rc = -EISCONN;
1116 		goto out;
1117 	case SMC_INIT:
1118 		break;
1119 	}
1120 
1121 	smc_copy_sock_settings_to_clc(smc);
1122 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1123 	if (smc->connect_nonblock) {
1124 		rc = -EALREADY;
1125 		goto out;
1126 	}
1127 	rc = kernel_connect(smc->clcsock, addr, alen, flags);
1128 	if (rc && rc != -EINPROGRESS)
1129 		goto out;
1130 
1131 	sock_hold(&smc->sk); /* sock put in passive closing */
1132 	if (smc->use_fallback)
1133 		goto out;
1134 	if (flags & O_NONBLOCK) {
1135 		if (queue_work(smc_hs_wq, &smc->connect_work))
1136 			smc->connect_nonblock = 1;
1137 		rc = -EINPROGRESS;
1138 	} else {
1139 		rc = __smc_connect(smc);
1140 		if (rc < 0)
1141 			goto out;
1142 		else
1143 			rc = 0; /* success cases including fallback */
1144 	}
1145 
1146 out:
1147 	release_sock(sk);
1148 out_err:
1149 	return rc;
1150 }
1151 
1152 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
1153 {
1154 	struct socket *new_clcsock = NULL;
1155 	struct sock *lsk = &lsmc->sk;
1156 	struct sock *new_sk;
1157 	int rc = -EINVAL;
1158 
1159 	release_sock(lsk);
1160 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
1161 	if (!new_sk) {
1162 		rc = -ENOMEM;
1163 		lsk->sk_err = ENOMEM;
1164 		*new_smc = NULL;
1165 		lock_sock(lsk);
1166 		goto out;
1167 	}
1168 	*new_smc = smc_sk(new_sk);
1169 
1170 	mutex_lock(&lsmc->clcsock_release_lock);
1171 	if (lsmc->clcsock)
1172 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, SOCK_NONBLOCK);
1173 	mutex_unlock(&lsmc->clcsock_release_lock);
1174 	lock_sock(lsk);
1175 	if  (rc < 0 && rc != -EAGAIN)
1176 		lsk->sk_err = -rc;
1177 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
1178 		new_sk->sk_prot->unhash(new_sk);
1179 		if (new_clcsock)
1180 			sock_release(new_clcsock);
1181 		new_sk->sk_state = SMC_CLOSED;
1182 		sock_set_flag(new_sk, SOCK_DEAD);
1183 		sock_put(new_sk); /* final */
1184 		*new_smc = NULL;
1185 		goto out;
1186 	}
1187 
1188 	/* new clcsock has inherited the smc listen-specific sk_data_ready
1189 	 * function; switch it back to the original sk_data_ready function
1190 	 */
1191 	new_clcsock->sk->sk_data_ready = lsmc->clcsk_data_ready;
1192 	(*new_smc)->clcsock = new_clcsock;
1193 out:
1194 	return rc;
1195 }
1196 
1197 /* add a just created sock to the accept queue of the listen sock as
1198  * candidate for a following socket accept call from user space
1199  */
1200 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
1201 {
1202 	struct smc_sock *par = smc_sk(parent);
1203 
1204 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
1205 	spin_lock(&par->accept_q_lock);
1206 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
1207 	spin_unlock(&par->accept_q_lock);
1208 	sk_acceptq_added(parent);
1209 }
1210 
1211 /* remove a socket from the accept queue of its parental listening socket */
1212 static void smc_accept_unlink(struct sock *sk)
1213 {
1214 	struct smc_sock *par = smc_sk(sk)->listen_smc;
1215 
1216 	spin_lock(&par->accept_q_lock);
1217 	list_del_init(&smc_sk(sk)->accept_q);
1218 	spin_unlock(&par->accept_q_lock);
1219 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
1220 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
1221 }
1222 
1223 /* remove a sock from the accept queue to bind it to a new socket created
1224  * for a socket accept call from user space
1225  */
1226 struct sock *smc_accept_dequeue(struct sock *parent,
1227 				struct socket *new_sock)
1228 {
1229 	struct smc_sock *isk, *n;
1230 	struct sock *new_sk;
1231 
1232 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
1233 		new_sk = (struct sock *)isk;
1234 
1235 		smc_accept_unlink(new_sk);
1236 		if (new_sk->sk_state == SMC_CLOSED) {
1237 			new_sk->sk_prot->unhash(new_sk);
1238 			if (isk->clcsock) {
1239 				sock_release(isk->clcsock);
1240 				isk->clcsock = NULL;
1241 			}
1242 			sock_put(new_sk); /* final */
1243 			continue;
1244 		}
1245 		if (new_sock) {
1246 			sock_graft(new_sk, new_sock);
1247 			if (isk->use_fallback) {
1248 				smc_sk(new_sk)->clcsock->file = new_sock->file;
1249 				isk->clcsock->file->private_data = isk->clcsock;
1250 			}
1251 		}
1252 		return new_sk;
1253 	}
1254 	return NULL;
1255 }
1256 
1257 /* clean up for a created but never accepted sock */
1258 void smc_close_non_accepted(struct sock *sk)
1259 {
1260 	struct smc_sock *smc = smc_sk(sk);
1261 
1262 	sock_hold(sk); /* sock_put below */
1263 	lock_sock(sk);
1264 	if (!sk->sk_lingertime)
1265 		/* wait for peer closing */
1266 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
1267 	__smc_release(smc);
1268 	release_sock(sk);
1269 	sock_put(sk); /* sock_hold above */
1270 	sock_put(sk); /* final sock_put */
1271 }
1272 
1273 static int smcr_serv_conf_first_link(struct smc_sock *smc)
1274 {
1275 	struct smc_link *link = smc->conn.lnk;
1276 	struct smc_llc_qentry *qentry;
1277 	int rc;
1278 
1279 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc))
1280 		return SMC_CLC_DECL_ERR_REGRMB;
1281 
1282 	/* send CONFIRM LINK request to client over the RoCE fabric */
1283 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
1284 	if (rc < 0)
1285 		return SMC_CLC_DECL_TIMEOUT_CL;
1286 
1287 	/* receive CONFIRM LINK response from client over the RoCE fabric */
1288 	qentry = smc_llc_wait(link->lgr, link, SMC_LLC_WAIT_TIME,
1289 			      SMC_LLC_CONFIRM_LINK);
1290 	if (!qentry) {
1291 		struct smc_clc_msg_decline dclc;
1292 
1293 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1294 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1295 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
1296 	}
1297 	smc_llc_save_peer_uid(qentry);
1298 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_RESP);
1299 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
1300 	if (rc)
1301 		return SMC_CLC_DECL_RMBE_EC;
1302 
1303 	/* confirm_rkey is implicit on 1st contact */
1304 	smc->conn.rmb_desc->is_conf_rkey = true;
1305 
1306 	smc_llc_link_active(link);
1307 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
1308 
1309 	/* initial contact - try to establish second link */
1310 	smc_llc_srv_add_link(link);
1311 	return 0;
1312 }
1313 
1314 /* listen worker: finish */
1315 static void smc_listen_out(struct smc_sock *new_smc)
1316 {
1317 	struct smc_sock *lsmc = new_smc->listen_smc;
1318 	struct sock *newsmcsk = &new_smc->sk;
1319 
1320 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1321 		lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1322 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1323 		release_sock(&lsmc->sk);
1324 	} else { /* no longer listening */
1325 		smc_close_non_accepted(newsmcsk);
1326 	}
1327 
1328 	/* Wake up accept */
1329 	lsmc->sk.sk_data_ready(&lsmc->sk);
1330 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1331 }
1332 
1333 /* listen worker: finish in state connected */
1334 static void smc_listen_out_connected(struct smc_sock *new_smc)
1335 {
1336 	struct sock *newsmcsk = &new_smc->sk;
1337 
1338 	sk_refcnt_debug_inc(newsmcsk);
1339 	if (newsmcsk->sk_state == SMC_INIT)
1340 		newsmcsk->sk_state = SMC_ACTIVE;
1341 
1342 	smc_listen_out(new_smc);
1343 }
1344 
1345 /* listen worker: finish in error state */
1346 static void smc_listen_out_err(struct smc_sock *new_smc)
1347 {
1348 	struct sock *newsmcsk = &new_smc->sk;
1349 	struct net *net = sock_net(newsmcsk);
1350 
1351 	this_cpu_inc(net->smc.smc_stats->srv_hshake_err_cnt);
1352 	if (newsmcsk->sk_state == SMC_INIT)
1353 		sock_put(&new_smc->sk); /* passive closing */
1354 	newsmcsk->sk_state = SMC_CLOSED;
1355 
1356 	smc_listen_out(new_smc);
1357 }
1358 
1359 /* listen worker: decline and fall back if possible */
1360 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1361 			       int local_first, u8 version)
1362 {
1363 	/* RDMA setup failed, switch back to TCP */
1364 	smc_conn_abort(new_smc, local_first);
1365 	if (reason_code < 0) { /* error, no fallback possible */
1366 		smc_listen_out_err(new_smc);
1367 		return;
1368 	}
1369 	smc_switch_to_fallback(new_smc, reason_code);
1370 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1371 		if (smc_clc_send_decline(new_smc, reason_code, version) < 0) {
1372 			smc_listen_out_err(new_smc);
1373 			return;
1374 		}
1375 	}
1376 	smc_listen_out_connected(new_smc);
1377 }
1378 
1379 /* listen worker: version checking */
1380 static int smc_listen_v2_check(struct smc_sock *new_smc,
1381 			       struct smc_clc_msg_proposal *pclc,
1382 			       struct smc_init_info *ini)
1383 {
1384 	struct smc_clc_smcd_v2_extension *pclc_smcd_v2_ext;
1385 	struct smc_clc_v2_extension *pclc_v2_ext;
1386 	int rc = SMC_CLC_DECL_PEERNOSMC;
1387 
1388 	ini->smc_type_v1 = pclc->hdr.typev1;
1389 	ini->smc_type_v2 = pclc->hdr.typev2;
1390 	ini->smcd_version = ini->smc_type_v1 != SMC_TYPE_N ? SMC_V1 : 0;
1391 	if (pclc->hdr.version > SMC_V1)
1392 		ini->smcd_version |=
1393 				ini->smc_type_v2 != SMC_TYPE_N ? SMC_V2 : 0;
1394 	if (!(ini->smcd_version & SMC_V2)) {
1395 		rc = SMC_CLC_DECL_PEERNOSMC;
1396 		goto out;
1397 	}
1398 	if (!smc_ism_is_v2_capable()) {
1399 		ini->smcd_version &= ~SMC_V2;
1400 		rc = SMC_CLC_DECL_NOISM2SUPP;
1401 		goto out;
1402 	}
1403 	pclc_v2_ext = smc_get_clc_v2_ext(pclc);
1404 	if (!pclc_v2_ext) {
1405 		ini->smcd_version &= ~SMC_V2;
1406 		rc = SMC_CLC_DECL_NOV2EXT;
1407 		goto out;
1408 	}
1409 	pclc_smcd_v2_ext = smc_get_clc_smcd_v2_ext(pclc_v2_ext);
1410 	if (!pclc_smcd_v2_ext) {
1411 		ini->smcd_version &= ~SMC_V2;
1412 		rc = SMC_CLC_DECL_NOV2DEXT;
1413 	}
1414 
1415 out:
1416 	if (!ini->smcd_version)
1417 		return rc;
1418 
1419 	return 0;
1420 }
1421 
1422 /* listen worker: check prefixes */
1423 static int smc_listen_prfx_check(struct smc_sock *new_smc,
1424 				 struct smc_clc_msg_proposal *pclc)
1425 {
1426 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1427 	struct socket *newclcsock = new_smc->clcsock;
1428 
1429 	if (pclc->hdr.typev1 == SMC_TYPE_N)
1430 		return 0;
1431 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1432 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1433 		return SMC_CLC_DECL_DIFFPREFIX;
1434 
1435 	return 0;
1436 }
1437 
1438 /* listen worker: initialize connection and buffers */
1439 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1440 				struct smc_init_info *ini)
1441 {
1442 	int rc;
1443 
1444 	/* allocate connection / link group */
1445 	rc = smc_conn_create(new_smc, ini);
1446 	if (rc)
1447 		return rc;
1448 
1449 	/* create send buffer and rmb */
1450 	if (smc_buf_create(new_smc, false))
1451 		return SMC_CLC_DECL_MEM;
1452 
1453 	return 0;
1454 }
1455 
1456 /* listen worker: initialize connection and buffers for SMC-D */
1457 static int smc_listen_ism_init(struct smc_sock *new_smc,
1458 			       struct smc_init_info *ini)
1459 {
1460 	int rc;
1461 
1462 	rc = smc_conn_create(new_smc, ini);
1463 	if (rc)
1464 		return rc;
1465 
1466 	/* Create send and receive buffers */
1467 	rc = smc_buf_create(new_smc, true);
1468 	if (rc) {
1469 		smc_conn_abort(new_smc, ini->first_contact_local);
1470 		return (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB :
1471 					 SMC_CLC_DECL_MEM;
1472 	}
1473 
1474 	return 0;
1475 }
1476 
1477 static bool smc_is_already_selected(struct smcd_dev *smcd,
1478 				    struct smc_init_info *ini,
1479 				    int matches)
1480 {
1481 	int i;
1482 
1483 	for (i = 0; i < matches; i++)
1484 		if (smcd == ini->ism_dev[i])
1485 			return true;
1486 
1487 	return false;
1488 }
1489 
1490 /* check for ISM devices matching proposed ISM devices */
1491 static void smc_check_ism_v2_match(struct smc_init_info *ini,
1492 				   u16 proposed_chid, u64 proposed_gid,
1493 				   unsigned int *matches)
1494 {
1495 	struct smcd_dev *smcd;
1496 
1497 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
1498 		if (smcd->going_away)
1499 			continue;
1500 		if (smc_is_already_selected(smcd, ini, *matches))
1501 			continue;
1502 		if (smc_ism_get_chid(smcd) == proposed_chid &&
1503 		    !smc_ism_cantalk(proposed_gid, ISM_RESERVED_VLANID, smcd)) {
1504 			ini->ism_peer_gid[*matches] = proposed_gid;
1505 			ini->ism_dev[*matches] = smcd;
1506 			(*matches)++;
1507 			break;
1508 		}
1509 	}
1510 }
1511 
1512 static void smc_find_ism_store_rc(u32 rc, struct smc_init_info *ini)
1513 {
1514 	if (!ini->rc)
1515 		ini->rc = rc;
1516 }
1517 
1518 static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
1519 					struct smc_clc_msg_proposal *pclc,
1520 					struct smc_init_info *ini)
1521 {
1522 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
1523 	struct smc_clc_v2_extension *smc_v2_ext;
1524 	struct smc_clc_msg_smcd *pclc_smcd;
1525 	unsigned int matches = 0;
1526 	u8 smcd_version;
1527 	u8 *eid = NULL;
1528 	int i, rc;
1529 
1530 	if (!(ini->smcd_version & SMC_V2) || !smcd_indicated(ini->smc_type_v2))
1531 		goto not_found;
1532 
1533 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
1534 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
1535 	smcd_v2_ext = smc_get_clc_smcd_v2_ext(smc_v2_ext);
1536 	if (!smcd_v2_ext ||
1537 	    !smc_v2_ext->hdr.flag.seid) { /* no system EID support for SMCD */
1538 		smc_find_ism_store_rc(SMC_CLC_DECL_NOSEID, ini);
1539 		goto not_found;
1540 	}
1541 
1542 	mutex_lock(&smcd_dev_list.mutex);
1543 	if (pclc_smcd->ism.chid)
1544 		/* check for ISM device matching proposed native ISM device */
1545 		smc_check_ism_v2_match(ini, ntohs(pclc_smcd->ism.chid),
1546 				       ntohll(pclc_smcd->ism.gid), &matches);
1547 	for (i = 1; i <= smc_v2_ext->hdr.ism_gid_cnt; i++) {
1548 		/* check for ISM devices matching proposed non-native ISM
1549 		 * devices
1550 		 */
1551 		smc_check_ism_v2_match(ini,
1552 				       ntohs(smcd_v2_ext->gidchid[i - 1].chid),
1553 				       ntohll(smcd_v2_ext->gidchid[i - 1].gid),
1554 				       &matches);
1555 	}
1556 	mutex_unlock(&smcd_dev_list.mutex);
1557 
1558 	if (ini->ism_dev[0]) {
1559 		smc_ism_get_system_eid(ini->ism_dev[0], &eid);
1560 		if (memcmp(eid, smcd_v2_ext->system_eid, SMC_MAX_EID_LEN))
1561 			goto not_found;
1562 	} else {
1563 		goto not_found;
1564 	}
1565 
1566 	/* separate - outside the smcd_dev_list.lock */
1567 	smcd_version = ini->smcd_version;
1568 	for (i = 0; i < matches; i++) {
1569 		ini->smcd_version = SMC_V2;
1570 		ini->is_smcd = true;
1571 		ini->ism_selected = i;
1572 		rc = smc_listen_ism_init(new_smc, ini);
1573 		if (rc) {
1574 			smc_find_ism_store_rc(rc, ini);
1575 			/* try next active ISM device */
1576 			continue;
1577 		}
1578 		return; /* matching and usable V2 ISM device found */
1579 	}
1580 	/* no V2 ISM device could be initialized */
1581 	ini->smcd_version = smcd_version;	/* restore original value */
1582 
1583 not_found:
1584 	ini->smcd_version &= ~SMC_V2;
1585 	ini->ism_dev[0] = NULL;
1586 	ini->is_smcd = false;
1587 }
1588 
1589 static void smc_find_ism_v1_device_serv(struct smc_sock *new_smc,
1590 					struct smc_clc_msg_proposal *pclc,
1591 					struct smc_init_info *ini)
1592 {
1593 	struct smc_clc_msg_smcd *pclc_smcd = smc_get_clc_msg_smcd(pclc);
1594 	int rc = 0;
1595 
1596 	/* check if ISM V1 is available */
1597 	if (!(ini->smcd_version & SMC_V1) || !smcd_indicated(ini->smc_type_v1))
1598 		goto not_found;
1599 	ini->is_smcd = true; /* prepare ISM check */
1600 	ini->ism_peer_gid[0] = ntohll(pclc_smcd->ism.gid);
1601 	rc = smc_find_ism_device(new_smc, ini);
1602 	if (rc)
1603 		goto not_found;
1604 	ini->ism_selected = 0;
1605 	rc = smc_listen_ism_init(new_smc, ini);
1606 	if (!rc)
1607 		return;		/* V1 ISM device found */
1608 
1609 not_found:
1610 	smc_find_ism_store_rc(rc, ini);
1611 	ini->ism_dev[0] = NULL;
1612 	ini->is_smcd = false;
1613 }
1614 
1615 /* listen worker: register buffers */
1616 static int smc_listen_rdma_reg(struct smc_sock *new_smc, bool local_first)
1617 {
1618 	struct smc_connection *conn = &new_smc->conn;
1619 
1620 	if (!local_first) {
1621 		if (smcr_lgr_reg_rmbs(conn->lnk, conn->rmb_desc))
1622 			return SMC_CLC_DECL_ERR_REGRMB;
1623 	}
1624 	smc_rmb_sync_sg_for_device(&new_smc->conn);
1625 
1626 	return 0;
1627 }
1628 
1629 static int smc_find_rdma_v1_device_serv(struct smc_sock *new_smc,
1630 					struct smc_clc_msg_proposal *pclc,
1631 					struct smc_init_info *ini)
1632 {
1633 	int rc;
1634 
1635 	if (!smcr_indicated(ini->smc_type_v1))
1636 		return SMC_CLC_DECL_NOSMCDEV;
1637 
1638 	/* prepare RDMA check */
1639 	ini->ib_lcl = &pclc->lcl;
1640 	rc = smc_find_rdma_device(new_smc, ini);
1641 	if (rc) {
1642 		/* no RDMA device found */
1643 		if (ini->smc_type_v1 == SMC_TYPE_B)
1644 			/* neither ISM nor RDMA device found */
1645 			rc = SMC_CLC_DECL_NOSMCDEV;
1646 		return rc;
1647 	}
1648 	rc = smc_listen_rdma_init(new_smc, ini);
1649 	if (rc)
1650 		return rc;
1651 	return smc_listen_rdma_reg(new_smc, ini->first_contact_local);
1652 }
1653 
1654 /* determine the local device matching to proposal */
1655 static int smc_listen_find_device(struct smc_sock *new_smc,
1656 				  struct smc_clc_msg_proposal *pclc,
1657 				  struct smc_init_info *ini)
1658 {
1659 	int rc;
1660 
1661 	/* check for ISM device matching V2 proposed device */
1662 	smc_find_ism_v2_device_serv(new_smc, pclc, ini);
1663 	if (ini->ism_dev[0])
1664 		return 0;
1665 
1666 	if (!(ini->smcd_version & SMC_V1))
1667 		return ini->rc ?: SMC_CLC_DECL_NOSMCD2DEV;
1668 
1669 	/* check for matching IP prefix and subnet length */
1670 	rc = smc_listen_prfx_check(new_smc, pclc);
1671 	if (rc)
1672 		return ini->rc ?: rc;
1673 
1674 	/* get vlan id from IP device */
1675 	if (smc_vlan_by_tcpsk(new_smc->clcsock, ini))
1676 		return ini->rc ?: SMC_CLC_DECL_GETVLANERR;
1677 
1678 	/* check for ISM device matching V1 proposed device */
1679 	smc_find_ism_v1_device_serv(new_smc, pclc, ini);
1680 	if (ini->ism_dev[0])
1681 		return 0;
1682 
1683 	if (pclc->hdr.typev1 == SMC_TYPE_D)
1684 		/* skip RDMA and decline */
1685 		return ini->rc ?: SMC_CLC_DECL_NOSMCDDEV;
1686 
1687 	/* check if RDMA is available */
1688 	rc = smc_find_rdma_v1_device_serv(new_smc, pclc, ini);
1689 	smc_find_ism_store_rc(rc, ini);
1690 
1691 	return (!rc) ? 0 : ini->rc;
1692 }
1693 
1694 /* listen worker: finish RDMA setup */
1695 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
1696 				  struct smc_clc_msg_accept_confirm *cclc,
1697 				  bool local_first)
1698 {
1699 	struct smc_link *link = new_smc->conn.lnk;
1700 	int reason_code = 0;
1701 
1702 	if (local_first)
1703 		smc_link_save_peer_info(link, cclc);
1704 
1705 	if (smc_rmb_rtoken_handling(&new_smc->conn, link, cclc))
1706 		return SMC_CLC_DECL_ERR_RTOK;
1707 
1708 	if (local_first) {
1709 		if (smc_ib_ready_link(link))
1710 			return SMC_CLC_DECL_ERR_RDYLNK;
1711 		/* QP confirmation over RoCE fabric */
1712 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
1713 		reason_code = smcr_serv_conf_first_link(new_smc);
1714 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
1715 	}
1716 	return reason_code;
1717 }
1718 
1719 /* setup for connection of server */
1720 static void smc_listen_work(struct work_struct *work)
1721 {
1722 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
1723 						smc_listen_work);
1724 	u8 version = smc_ism_is_v2_capable() ? SMC_V2 : SMC_V1;
1725 	struct socket *newclcsock = new_smc->clcsock;
1726 	struct smc_clc_msg_accept_confirm *cclc;
1727 	struct smc_clc_msg_proposal_area *buf;
1728 	struct smc_clc_msg_proposal *pclc;
1729 	struct smc_init_info *ini = NULL;
1730 	int rc = 0;
1731 
1732 	if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
1733 		return smc_listen_out_err(new_smc);
1734 
1735 	if (new_smc->use_fallback) {
1736 		smc_listen_out_connected(new_smc);
1737 		return;
1738 	}
1739 
1740 	/* check if peer is smc capable */
1741 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
1742 		smc_switch_to_fallback(new_smc, SMC_CLC_DECL_PEERNOSMC);
1743 		smc_listen_out_connected(new_smc);
1744 		return;
1745 	}
1746 
1747 	/* do inband token exchange -
1748 	 * wait for and receive SMC Proposal CLC message
1749 	 */
1750 	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
1751 	if (!buf) {
1752 		rc = SMC_CLC_DECL_MEM;
1753 		goto out_decl;
1754 	}
1755 	pclc = (struct smc_clc_msg_proposal *)buf;
1756 	rc = smc_clc_wait_msg(new_smc, pclc, sizeof(*buf),
1757 			      SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
1758 	if (rc)
1759 		goto out_decl;
1760 	version = pclc->hdr.version == SMC_V1 ? SMC_V1 : version;
1761 
1762 	/* IPSec connections opt out of SMC optimizations */
1763 	if (using_ipsec(new_smc)) {
1764 		rc = SMC_CLC_DECL_IPSEC;
1765 		goto out_decl;
1766 	}
1767 
1768 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1769 	if (!ini) {
1770 		rc = SMC_CLC_DECL_MEM;
1771 		goto out_decl;
1772 	}
1773 
1774 	/* initial version checking */
1775 	rc = smc_listen_v2_check(new_smc, pclc, ini);
1776 	if (rc)
1777 		goto out_decl;
1778 
1779 	mutex_lock(&smc_server_lgr_pending);
1780 	smc_close_init(new_smc);
1781 	smc_rx_init(new_smc);
1782 	smc_tx_init(new_smc);
1783 
1784 	/* determine ISM or RoCE device used for connection */
1785 	rc = smc_listen_find_device(new_smc, pclc, ini);
1786 	if (rc)
1787 		goto out_unlock;
1788 
1789 	/* send SMC Accept CLC message */
1790 	rc = smc_clc_send_accept(new_smc, ini->first_contact_local,
1791 				 ini->smcd_version == SMC_V2 ? SMC_V2 : SMC_V1);
1792 	if (rc)
1793 		goto out_unlock;
1794 
1795 	/* SMC-D does not need this lock any more */
1796 	if (ini->is_smcd)
1797 		mutex_unlock(&smc_server_lgr_pending);
1798 
1799 	/* receive SMC Confirm CLC message */
1800 	memset(buf, 0, sizeof(*buf));
1801 	cclc = (struct smc_clc_msg_accept_confirm *)buf;
1802 	rc = smc_clc_wait_msg(new_smc, cclc, sizeof(*buf),
1803 			      SMC_CLC_CONFIRM, CLC_WAIT_TIME);
1804 	if (rc) {
1805 		if (!ini->is_smcd)
1806 			goto out_unlock;
1807 		goto out_decl;
1808 	}
1809 
1810 	/* finish worker */
1811 	if (!ini->is_smcd) {
1812 		rc = smc_listen_rdma_finish(new_smc, cclc,
1813 					    ini->first_contact_local);
1814 		if (rc)
1815 			goto out_unlock;
1816 		mutex_unlock(&smc_server_lgr_pending);
1817 	}
1818 	smc_conn_save_peer_info(new_smc, cclc);
1819 	smc_listen_out_connected(new_smc);
1820 	SMC_STAT_SERV_SUCC_INC(sock_net(newclcsock->sk), ini);
1821 	goto out_free;
1822 
1823 out_unlock:
1824 	mutex_unlock(&smc_server_lgr_pending);
1825 out_decl:
1826 	smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0,
1827 			   version);
1828 out_free:
1829 	kfree(ini);
1830 	kfree(buf);
1831 }
1832 
1833 static void smc_tcp_listen_work(struct work_struct *work)
1834 {
1835 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
1836 					     tcp_listen_work);
1837 	struct sock *lsk = &lsmc->sk;
1838 	struct smc_sock *new_smc;
1839 	int rc = 0;
1840 
1841 	lock_sock(lsk);
1842 	while (lsk->sk_state == SMC_LISTEN) {
1843 		rc = smc_clcsock_accept(lsmc, &new_smc);
1844 		if (rc) /* clcsock accept queue empty or error */
1845 			goto out;
1846 		if (!new_smc)
1847 			continue;
1848 
1849 		new_smc->listen_smc = lsmc;
1850 		new_smc->use_fallback = lsmc->use_fallback;
1851 		new_smc->fallback_rsn = lsmc->fallback_rsn;
1852 		sock_hold(lsk); /* sock_put in smc_listen_work */
1853 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
1854 		smc_copy_sock_settings_to_smc(new_smc);
1855 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
1856 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
1857 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
1858 		if (!queue_work(smc_hs_wq, &new_smc->smc_listen_work))
1859 			sock_put(&new_smc->sk);
1860 	}
1861 
1862 out:
1863 	release_sock(lsk);
1864 	sock_put(&lsmc->sk); /* sock_hold in smc_clcsock_data_ready() */
1865 }
1866 
1867 static void smc_clcsock_data_ready(struct sock *listen_clcsock)
1868 {
1869 	struct smc_sock *lsmc;
1870 
1871 	lsmc = (struct smc_sock *)
1872 	       ((uintptr_t)listen_clcsock->sk_user_data & ~SK_USER_DATA_NOCOPY);
1873 	if (!lsmc)
1874 		return;
1875 	lsmc->clcsk_data_ready(listen_clcsock);
1876 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1877 		sock_hold(&lsmc->sk); /* sock_put in smc_tcp_listen_work() */
1878 		if (!queue_work(smc_hs_wq, &lsmc->tcp_listen_work))
1879 			sock_put(&lsmc->sk);
1880 	}
1881 }
1882 
1883 static int smc_listen(struct socket *sock, int backlog)
1884 {
1885 	struct sock *sk = sock->sk;
1886 	struct smc_sock *smc;
1887 	int rc;
1888 
1889 	smc = smc_sk(sk);
1890 	lock_sock(sk);
1891 
1892 	rc = -EINVAL;
1893 	if ((sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) ||
1894 	    smc->connect_nonblock)
1895 		goto out;
1896 
1897 	rc = 0;
1898 	if (sk->sk_state == SMC_LISTEN) {
1899 		sk->sk_max_ack_backlog = backlog;
1900 		goto out;
1901 	}
1902 	/* some socket options are handled in core, so we could not apply
1903 	 * them to the clc socket -- copy smc socket options to clc socket
1904 	 */
1905 	smc_copy_sock_settings_to_clc(smc);
1906 	if (!smc->use_fallback)
1907 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1908 
1909 	/* save original sk_data_ready function and establish
1910 	 * smc-specific sk_data_ready function
1911 	 */
1912 	smc->clcsk_data_ready = smc->clcsock->sk->sk_data_ready;
1913 	smc->clcsock->sk->sk_data_ready = smc_clcsock_data_ready;
1914 	smc->clcsock->sk->sk_user_data =
1915 		(void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
1916 	rc = kernel_listen(smc->clcsock, backlog);
1917 	if (rc)
1918 		goto out;
1919 	sk->sk_max_ack_backlog = backlog;
1920 	sk->sk_ack_backlog = 0;
1921 	sk->sk_state = SMC_LISTEN;
1922 
1923 out:
1924 	release_sock(sk);
1925 	return rc;
1926 }
1927 
1928 static int smc_accept(struct socket *sock, struct socket *new_sock,
1929 		      int flags, bool kern)
1930 {
1931 	struct sock *sk = sock->sk, *nsk;
1932 	DECLARE_WAITQUEUE(wait, current);
1933 	struct smc_sock *lsmc;
1934 	long timeo;
1935 	int rc = 0;
1936 
1937 	lsmc = smc_sk(sk);
1938 	sock_hold(sk); /* sock_put below */
1939 	lock_sock(sk);
1940 
1941 	if (lsmc->sk.sk_state != SMC_LISTEN) {
1942 		rc = -EINVAL;
1943 		release_sock(sk);
1944 		goto out;
1945 	}
1946 
1947 	/* Wait for an incoming connection */
1948 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1949 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
1950 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1951 		set_current_state(TASK_INTERRUPTIBLE);
1952 		if (!timeo) {
1953 			rc = -EAGAIN;
1954 			break;
1955 		}
1956 		release_sock(sk);
1957 		timeo = schedule_timeout(timeo);
1958 		/* wakeup by sk_data_ready in smc_listen_work() */
1959 		sched_annotate_sleep();
1960 		lock_sock(sk);
1961 		if (signal_pending(current)) {
1962 			rc = sock_intr_errno(timeo);
1963 			break;
1964 		}
1965 	}
1966 	set_current_state(TASK_RUNNING);
1967 	remove_wait_queue(sk_sleep(sk), &wait);
1968 
1969 	if (!rc)
1970 		rc = sock_error(nsk);
1971 	release_sock(sk);
1972 	if (rc)
1973 		goto out;
1974 
1975 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
1976 		/* wait till data arrives on the socket */
1977 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
1978 								MSEC_PER_SEC);
1979 		if (smc_sk(nsk)->use_fallback) {
1980 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
1981 
1982 			lock_sock(clcsk);
1983 			if (skb_queue_empty(&clcsk->sk_receive_queue))
1984 				sk_wait_data(clcsk, &timeo, NULL);
1985 			release_sock(clcsk);
1986 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
1987 			lock_sock(nsk);
1988 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
1989 			release_sock(nsk);
1990 		}
1991 	}
1992 
1993 out:
1994 	sock_put(sk); /* sock_hold above */
1995 	return rc;
1996 }
1997 
1998 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1999 		       int peer)
2000 {
2001 	struct smc_sock *smc;
2002 
2003 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
2004 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
2005 		return -ENOTCONN;
2006 
2007 	smc = smc_sk(sock->sk);
2008 
2009 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
2010 }
2011 
2012 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2013 {
2014 	struct sock *sk = sock->sk;
2015 	struct smc_sock *smc;
2016 	int rc = -EPIPE;
2017 
2018 	smc = smc_sk(sk);
2019 	lock_sock(sk);
2020 	if ((sk->sk_state != SMC_ACTIVE) &&
2021 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2022 	    (sk->sk_state != SMC_INIT))
2023 		goto out;
2024 
2025 	if (msg->msg_flags & MSG_FASTOPEN) {
2026 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2027 			smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2028 		} else {
2029 			rc = -EINVAL;
2030 			goto out;
2031 		}
2032 	}
2033 
2034 	if (smc->use_fallback) {
2035 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
2036 	} else {
2037 		rc = smc_tx_sendmsg(smc, msg, len);
2038 		SMC_STAT_TX_PAYLOAD(smc, len, rc);
2039 	}
2040 out:
2041 	release_sock(sk);
2042 	return rc;
2043 }
2044 
2045 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2046 		       int flags)
2047 {
2048 	struct sock *sk = sock->sk;
2049 	struct smc_sock *smc;
2050 	int rc = -ENOTCONN;
2051 
2052 	smc = smc_sk(sk);
2053 	lock_sock(sk);
2054 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2055 		/* socket was connected before, no more data to read */
2056 		rc = 0;
2057 		goto out;
2058 	}
2059 	if ((sk->sk_state == SMC_INIT) ||
2060 	    (sk->sk_state == SMC_LISTEN) ||
2061 	    (sk->sk_state == SMC_CLOSED))
2062 		goto out;
2063 
2064 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2065 		rc = 0;
2066 		goto out;
2067 	}
2068 
2069 	if (smc->use_fallback) {
2070 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
2071 	} else {
2072 		msg->msg_namelen = 0;
2073 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
2074 		SMC_STAT_RX_PAYLOAD(smc, rc, rc);
2075 	}
2076 
2077 out:
2078 	release_sock(sk);
2079 	return rc;
2080 }
2081 
2082 static __poll_t smc_accept_poll(struct sock *parent)
2083 {
2084 	struct smc_sock *isk = smc_sk(parent);
2085 	__poll_t mask = 0;
2086 
2087 	spin_lock(&isk->accept_q_lock);
2088 	if (!list_empty(&isk->accept_q))
2089 		mask = EPOLLIN | EPOLLRDNORM;
2090 	spin_unlock(&isk->accept_q_lock);
2091 
2092 	return mask;
2093 }
2094 
2095 static __poll_t smc_poll(struct file *file, struct socket *sock,
2096 			     poll_table *wait)
2097 {
2098 	struct sock *sk = sock->sk;
2099 	struct smc_sock *smc;
2100 	__poll_t mask = 0;
2101 
2102 	if (!sk)
2103 		return EPOLLNVAL;
2104 
2105 	smc = smc_sk(sock->sk);
2106 	if (smc->use_fallback) {
2107 		/* delegate to CLC child sock */
2108 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
2109 		sk->sk_err = smc->clcsock->sk->sk_err;
2110 	} else {
2111 		if (sk->sk_state != SMC_CLOSED)
2112 			sock_poll_wait(file, sock, wait);
2113 		if (sk->sk_err)
2114 			mask |= EPOLLERR;
2115 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
2116 		    (sk->sk_state == SMC_CLOSED))
2117 			mask |= EPOLLHUP;
2118 		if (sk->sk_state == SMC_LISTEN) {
2119 			/* woken up by sk_data_ready in smc_listen_work() */
2120 			mask |= smc_accept_poll(sk);
2121 		} else if (smc->use_fallback) { /* as result of connect_work()*/
2122 			mask |= smc->clcsock->ops->poll(file, smc->clcsock,
2123 							   wait);
2124 			sk->sk_err = smc->clcsock->sk->sk_err;
2125 		} else {
2126 			if ((sk->sk_state != SMC_INIT &&
2127 			     atomic_read(&smc->conn.sndbuf_space)) ||
2128 			    sk->sk_shutdown & SEND_SHUTDOWN) {
2129 				mask |= EPOLLOUT | EPOLLWRNORM;
2130 			} else {
2131 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2132 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2133 			}
2134 			if (atomic_read(&smc->conn.bytes_to_rcv))
2135 				mask |= EPOLLIN | EPOLLRDNORM;
2136 			if (sk->sk_shutdown & RCV_SHUTDOWN)
2137 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
2138 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
2139 				mask |= EPOLLIN;
2140 			if (smc->conn.urg_state == SMC_URG_VALID)
2141 				mask |= EPOLLPRI;
2142 		}
2143 	}
2144 
2145 	return mask;
2146 }
2147 
2148 static int smc_shutdown(struct socket *sock, int how)
2149 {
2150 	struct sock *sk = sock->sk;
2151 	struct smc_sock *smc;
2152 	int rc = -EINVAL;
2153 	int rc1 = 0;
2154 
2155 	smc = smc_sk(sk);
2156 
2157 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
2158 		return rc;
2159 
2160 	lock_sock(sk);
2161 
2162 	rc = -ENOTCONN;
2163 	if ((sk->sk_state != SMC_ACTIVE) &&
2164 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
2165 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
2166 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2167 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
2168 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
2169 		goto out;
2170 	if (smc->use_fallback) {
2171 		rc = kernel_sock_shutdown(smc->clcsock, how);
2172 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
2173 		if (sk->sk_shutdown == SHUTDOWN_MASK)
2174 			sk->sk_state = SMC_CLOSED;
2175 		goto out;
2176 	}
2177 	switch (how) {
2178 	case SHUT_RDWR:		/* shutdown in both directions */
2179 		rc = smc_close_active(smc);
2180 		break;
2181 	case SHUT_WR:
2182 		rc = smc_close_shutdown_write(smc);
2183 		break;
2184 	case SHUT_RD:
2185 		rc = 0;
2186 		/* nothing more to do because peer is not involved */
2187 		break;
2188 	}
2189 	if (smc->clcsock)
2190 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
2191 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
2192 	sk->sk_shutdown |= how + 1;
2193 
2194 out:
2195 	release_sock(sk);
2196 	return rc ? rc : rc1;
2197 }
2198 
2199 static int smc_setsockopt(struct socket *sock, int level, int optname,
2200 			  sockptr_t optval, unsigned int optlen)
2201 {
2202 	struct sock *sk = sock->sk;
2203 	struct smc_sock *smc;
2204 	int val, rc;
2205 
2206 	if (level == SOL_TCP && optname == TCP_ULP)
2207 		return -EOPNOTSUPP;
2208 
2209 	smc = smc_sk(sk);
2210 
2211 	/* generic setsockopts reaching us here always apply to the
2212 	 * CLC socket
2213 	 */
2214 	if (unlikely(!smc->clcsock->ops->setsockopt))
2215 		rc = -EOPNOTSUPP;
2216 	else
2217 		rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
2218 						   optval, optlen);
2219 	if (smc->clcsock->sk->sk_err) {
2220 		sk->sk_err = smc->clcsock->sk->sk_err;
2221 		sk_error_report(sk);
2222 	}
2223 
2224 	if (optlen < sizeof(int))
2225 		return -EINVAL;
2226 	if (copy_from_sockptr(&val, optval, sizeof(int)))
2227 		return -EFAULT;
2228 
2229 	lock_sock(sk);
2230 	if (rc || smc->use_fallback)
2231 		goto out;
2232 	switch (optname) {
2233 	case TCP_FASTOPEN:
2234 	case TCP_FASTOPEN_CONNECT:
2235 	case TCP_FASTOPEN_KEY:
2236 	case TCP_FASTOPEN_NO_COOKIE:
2237 		/* option not supported by SMC */
2238 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2239 			smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2240 		} else {
2241 			rc = -EINVAL;
2242 		}
2243 		break;
2244 	case TCP_NODELAY:
2245 		if (sk->sk_state != SMC_INIT &&
2246 		    sk->sk_state != SMC_LISTEN &&
2247 		    sk->sk_state != SMC_CLOSED) {
2248 			if (val) {
2249 				SMC_STAT_INC(smc, ndly_cnt);
2250 				mod_delayed_work(smc->conn.lgr->tx_wq,
2251 						 &smc->conn.tx_work, 0);
2252 			}
2253 		}
2254 		break;
2255 	case TCP_CORK:
2256 		if (sk->sk_state != SMC_INIT &&
2257 		    sk->sk_state != SMC_LISTEN &&
2258 		    sk->sk_state != SMC_CLOSED) {
2259 			if (!val) {
2260 				SMC_STAT_INC(smc, cork_cnt);
2261 				mod_delayed_work(smc->conn.lgr->tx_wq,
2262 						 &smc->conn.tx_work, 0);
2263 			}
2264 		}
2265 		break;
2266 	case TCP_DEFER_ACCEPT:
2267 		smc->sockopt_defer_accept = val;
2268 		break;
2269 	default:
2270 		break;
2271 	}
2272 out:
2273 	release_sock(sk);
2274 
2275 	return rc;
2276 }
2277 
2278 static int smc_getsockopt(struct socket *sock, int level, int optname,
2279 			  char __user *optval, int __user *optlen)
2280 {
2281 	struct smc_sock *smc;
2282 
2283 	smc = smc_sk(sock->sk);
2284 	/* socket options apply to the CLC socket */
2285 	if (unlikely(!smc->clcsock->ops->getsockopt))
2286 		return -EOPNOTSUPP;
2287 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
2288 					     optval, optlen);
2289 }
2290 
2291 static int smc_ioctl(struct socket *sock, unsigned int cmd,
2292 		     unsigned long arg)
2293 {
2294 	union smc_host_cursor cons, urg;
2295 	struct smc_connection *conn;
2296 	struct smc_sock *smc;
2297 	int answ;
2298 
2299 	smc = smc_sk(sock->sk);
2300 	conn = &smc->conn;
2301 	lock_sock(&smc->sk);
2302 	if (smc->use_fallback) {
2303 		if (!smc->clcsock) {
2304 			release_sock(&smc->sk);
2305 			return -EBADF;
2306 		}
2307 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
2308 		release_sock(&smc->sk);
2309 		return answ;
2310 	}
2311 	switch (cmd) {
2312 	case SIOCINQ: /* same as FIONREAD */
2313 		if (smc->sk.sk_state == SMC_LISTEN) {
2314 			release_sock(&smc->sk);
2315 			return -EINVAL;
2316 		}
2317 		if (smc->sk.sk_state == SMC_INIT ||
2318 		    smc->sk.sk_state == SMC_CLOSED)
2319 			answ = 0;
2320 		else
2321 			answ = atomic_read(&smc->conn.bytes_to_rcv);
2322 		break;
2323 	case SIOCOUTQ:
2324 		/* output queue size (not send + not acked) */
2325 		if (smc->sk.sk_state == SMC_LISTEN) {
2326 			release_sock(&smc->sk);
2327 			return -EINVAL;
2328 		}
2329 		if (smc->sk.sk_state == SMC_INIT ||
2330 		    smc->sk.sk_state == SMC_CLOSED)
2331 			answ = 0;
2332 		else
2333 			answ = smc->conn.sndbuf_desc->len -
2334 					atomic_read(&smc->conn.sndbuf_space);
2335 		break;
2336 	case SIOCOUTQNSD:
2337 		/* output queue size (not send only) */
2338 		if (smc->sk.sk_state == SMC_LISTEN) {
2339 			release_sock(&smc->sk);
2340 			return -EINVAL;
2341 		}
2342 		if (smc->sk.sk_state == SMC_INIT ||
2343 		    smc->sk.sk_state == SMC_CLOSED)
2344 			answ = 0;
2345 		else
2346 			answ = smc_tx_prepared_sends(&smc->conn);
2347 		break;
2348 	case SIOCATMARK:
2349 		if (smc->sk.sk_state == SMC_LISTEN) {
2350 			release_sock(&smc->sk);
2351 			return -EINVAL;
2352 		}
2353 		if (smc->sk.sk_state == SMC_INIT ||
2354 		    smc->sk.sk_state == SMC_CLOSED) {
2355 			answ = 0;
2356 		} else {
2357 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
2358 			smc_curs_copy(&urg, &conn->urg_curs, conn);
2359 			answ = smc_curs_diff(conn->rmb_desc->len,
2360 					     &cons, &urg) == 1;
2361 		}
2362 		break;
2363 	default:
2364 		release_sock(&smc->sk);
2365 		return -ENOIOCTLCMD;
2366 	}
2367 	release_sock(&smc->sk);
2368 
2369 	return put_user(answ, (int __user *)arg);
2370 }
2371 
2372 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
2373 			    int offset, size_t size, int flags)
2374 {
2375 	struct sock *sk = sock->sk;
2376 	struct smc_sock *smc;
2377 	int rc = -EPIPE;
2378 
2379 	smc = smc_sk(sk);
2380 	lock_sock(sk);
2381 	if (sk->sk_state != SMC_ACTIVE) {
2382 		release_sock(sk);
2383 		goto out;
2384 	}
2385 	release_sock(sk);
2386 	if (smc->use_fallback) {
2387 		rc = kernel_sendpage(smc->clcsock, page, offset,
2388 				     size, flags);
2389 	} else {
2390 		SMC_STAT_INC(smc, sendpage_cnt);
2391 		rc = sock_no_sendpage(sock, page, offset, size, flags);
2392 	}
2393 
2394 out:
2395 	return rc;
2396 }
2397 
2398 /* Map the affected portions of the rmbe into an spd, note the number of bytes
2399  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
2400  * updates till whenever a respective page has been fully processed.
2401  * Note that subsequent recv() calls have to wait till all splice() processing
2402  * completed.
2403  */
2404 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
2405 			       struct pipe_inode_info *pipe, size_t len,
2406 			       unsigned int flags)
2407 {
2408 	struct sock *sk = sock->sk;
2409 	struct smc_sock *smc;
2410 	int rc = -ENOTCONN;
2411 
2412 	smc = smc_sk(sk);
2413 	lock_sock(sk);
2414 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2415 		/* socket was connected before, no more data to read */
2416 		rc = 0;
2417 		goto out;
2418 	}
2419 	if (sk->sk_state == SMC_INIT ||
2420 	    sk->sk_state == SMC_LISTEN ||
2421 	    sk->sk_state == SMC_CLOSED)
2422 		goto out;
2423 
2424 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2425 		rc = 0;
2426 		goto out;
2427 	}
2428 
2429 	if (smc->use_fallback) {
2430 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
2431 						    pipe, len, flags);
2432 	} else {
2433 		if (*ppos) {
2434 			rc = -ESPIPE;
2435 			goto out;
2436 		}
2437 		if (flags & SPLICE_F_NONBLOCK)
2438 			flags = MSG_DONTWAIT;
2439 		else
2440 			flags = 0;
2441 		SMC_STAT_INC(smc, splice_cnt);
2442 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
2443 	}
2444 out:
2445 	release_sock(sk);
2446 
2447 	return rc;
2448 }
2449 
2450 /* must look like tcp */
2451 static const struct proto_ops smc_sock_ops = {
2452 	.family		= PF_SMC,
2453 	.owner		= THIS_MODULE,
2454 	.release	= smc_release,
2455 	.bind		= smc_bind,
2456 	.connect	= smc_connect,
2457 	.socketpair	= sock_no_socketpair,
2458 	.accept		= smc_accept,
2459 	.getname	= smc_getname,
2460 	.poll		= smc_poll,
2461 	.ioctl		= smc_ioctl,
2462 	.listen		= smc_listen,
2463 	.shutdown	= smc_shutdown,
2464 	.setsockopt	= smc_setsockopt,
2465 	.getsockopt	= smc_getsockopt,
2466 	.sendmsg	= smc_sendmsg,
2467 	.recvmsg	= smc_recvmsg,
2468 	.mmap		= sock_no_mmap,
2469 	.sendpage	= smc_sendpage,
2470 	.splice_read	= smc_splice_read,
2471 };
2472 
2473 static int smc_create(struct net *net, struct socket *sock, int protocol,
2474 		      int kern)
2475 {
2476 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
2477 	struct smc_sock *smc;
2478 	struct sock *sk;
2479 	int rc;
2480 
2481 	rc = -ESOCKTNOSUPPORT;
2482 	if (sock->type != SOCK_STREAM)
2483 		goto out;
2484 
2485 	rc = -EPROTONOSUPPORT;
2486 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
2487 		goto out;
2488 
2489 	rc = -ENOBUFS;
2490 	sock->ops = &smc_sock_ops;
2491 	sk = smc_sock_alloc(net, sock, protocol);
2492 	if (!sk)
2493 		goto out;
2494 
2495 	/* create internal TCP socket for CLC handshake and fallback */
2496 	smc = smc_sk(sk);
2497 	smc->use_fallback = false; /* assume rdma capability first */
2498 	smc->fallback_rsn = 0;
2499 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
2500 			      &smc->clcsock);
2501 	if (rc) {
2502 		sk_common_release(sk);
2503 		goto out;
2504 	}
2505 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
2506 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
2507 
2508 out:
2509 	return rc;
2510 }
2511 
2512 static const struct net_proto_family smc_sock_family_ops = {
2513 	.family	= PF_SMC,
2514 	.owner	= THIS_MODULE,
2515 	.create	= smc_create,
2516 };
2517 
2518 unsigned int smc_net_id;
2519 
2520 static __net_init int smc_net_init(struct net *net)
2521 {
2522 	return smc_pnet_net_init(net);
2523 }
2524 
2525 static void __net_exit smc_net_exit(struct net *net)
2526 {
2527 	smc_pnet_net_exit(net);
2528 }
2529 
2530 static __net_init int smc_net_stat_init(struct net *net)
2531 {
2532 	return smc_stats_init(net);
2533 }
2534 
2535 static void __net_exit smc_net_stat_exit(struct net *net)
2536 {
2537 	smc_stats_exit(net);
2538 }
2539 
2540 static struct pernet_operations smc_net_ops = {
2541 	.init = smc_net_init,
2542 	.exit = smc_net_exit,
2543 	.id   = &smc_net_id,
2544 	.size = sizeof(struct smc_net),
2545 };
2546 
2547 static struct pernet_operations smc_net_stat_ops = {
2548 	.init = smc_net_stat_init,
2549 	.exit = smc_net_stat_exit,
2550 };
2551 
2552 static int __init smc_init(void)
2553 {
2554 	int rc;
2555 
2556 	rc = register_pernet_subsys(&smc_net_ops);
2557 	if (rc)
2558 		return rc;
2559 
2560 	rc = register_pernet_subsys(&smc_net_stat_ops);
2561 	if (rc)
2562 		return rc;
2563 
2564 	smc_ism_init();
2565 	smc_clc_init();
2566 
2567 	rc = smc_nl_init();
2568 	if (rc)
2569 		goto out_pernet_subsys;
2570 
2571 	rc = smc_pnet_init();
2572 	if (rc)
2573 		goto out_nl;
2574 
2575 	rc = -ENOMEM;
2576 	smc_hs_wq = alloc_workqueue("smc_hs_wq", 0, 0);
2577 	if (!smc_hs_wq)
2578 		goto out_pnet;
2579 
2580 	smc_close_wq = alloc_workqueue("smc_close_wq", 0, 0);
2581 	if (!smc_close_wq)
2582 		goto out_alloc_hs_wq;
2583 
2584 	rc = smc_core_init();
2585 	if (rc) {
2586 		pr_err("%s: smc_core_init fails with %d\n", __func__, rc);
2587 		goto out_alloc_wqs;
2588 	}
2589 
2590 	rc = smc_llc_init();
2591 	if (rc) {
2592 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
2593 		goto out_core;
2594 	}
2595 
2596 	rc = smc_cdc_init();
2597 	if (rc) {
2598 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
2599 		goto out_core;
2600 	}
2601 
2602 	rc = proto_register(&smc_proto, 1);
2603 	if (rc) {
2604 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
2605 		goto out_core;
2606 	}
2607 
2608 	rc = proto_register(&smc_proto6, 1);
2609 	if (rc) {
2610 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
2611 		goto out_proto;
2612 	}
2613 
2614 	rc = sock_register(&smc_sock_family_ops);
2615 	if (rc) {
2616 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
2617 		goto out_proto6;
2618 	}
2619 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
2620 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
2621 
2622 	rc = smc_ib_register_client();
2623 	if (rc) {
2624 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
2625 		goto out_sock;
2626 	}
2627 
2628 	static_branch_enable(&tcp_have_smc);
2629 	return 0;
2630 
2631 out_sock:
2632 	sock_unregister(PF_SMC);
2633 out_proto6:
2634 	proto_unregister(&smc_proto6);
2635 out_proto:
2636 	proto_unregister(&smc_proto);
2637 out_core:
2638 	smc_core_exit();
2639 out_alloc_wqs:
2640 	destroy_workqueue(smc_close_wq);
2641 out_alloc_hs_wq:
2642 	destroy_workqueue(smc_hs_wq);
2643 out_pnet:
2644 	smc_pnet_exit();
2645 out_nl:
2646 	smc_nl_exit();
2647 out_pernet_subsys:
2648 	unregister_pernet_subsys(&smc_net_ops);
2649 
2650 	return rc;
2651 }
2652 
2653 static void __exit smc_exit(void)
2654 {
2655 	static_branch_disable(&tcp_have_smc);
2656 	sock_unregister(PF_SMC);
2657 	smc_core_exit();
2658 	smc_ib_unregister_client();
2659 	destroy_workqueue(smc_close_wq);
2660 	destroy_workqueue(smc_hs_wq);
2661 	proto_unregister(&smc_proto6);
2662 	proto_unregister(&smc_proto);
2663 	smc_pnet_exit();
2664 	smc_nl_exit();
2665 	unregister_pernet_subsys(&smc_net_stat_ops);
2666 	unregister_pernet_subsys(&smc_net_ops);
2667 	rcu_barrier();
2668 }
2669 
2670 module_init(smc_init);
2671 module_exit(smc_exit);
2672 
2673 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
2674 MODULE_DESCRIPTION("smc socket address family");
2675 MODULE_LICENSE("GPL");
2676 MODULE_ALIAS_NETPROTO(PF_SMC);
2677