xref: /linux/net/smc/af_smc.c (revision f3956ebb3bf06ab2266ad5ee2214aed46405810c)
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, NULL);
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 	u8 *eid = NULL;
887 	int rc = 0;
888 
889 	ini->is_smcd = true;
890 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
891 
892 	if (aclc->hdr.version == SMC_V2) {
893 		struct smc_clc_msg_accept_confirm_v2 *aclc_v2 =
894 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
895 
896 		rc = smc_v2_determine_accepted_chid(aclc_v2, ini);
897 		if (rc)
898 			return rc;
899 	}
900 	ini->ism_peer_gid[ini->ism_selected] = aclc->d0.gid;
901 
902 	/* there is only one lgr role for SMC-D; use server lock */
903 	mutex_lock(&smc_server_lgr_pending);
904 	rc = smc_conn_create(smc, ini);
905 	if (rc) {
906 		mutex_unlock(&smc_server_lgr_pending);
907 		return rc;
908 	}
909 
910 	/* Create send and receive buffers */
911 	rc = smc_buf_create(smc, true);
912 	if (rc) {
913 		rc = (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB : SMC_CLC_DECL_MEM;
914 		goto connect_abort;
915 	}
916 
917 	smc_conn_save_peer_info(smc, aclc);
918 	smc_close_init(smc);
919 	smc_rx_init(smc);
920 	smc_tx_init(smc);
921 
922 	if (aclc->hdr.version > SMC_V1) {
923 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
924 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
925 
926 		eid = clc_v2->eid;
927 	}
928 
929 	rc = smc_clc_send_confirm(smc, ini->first_contact_local,
930 				  aclc->hdr.version, eid);
931 	if (rc)
932 		goto connect_abort;
933 	mutex_unlock(&smc_server_lgr_pending);
934 
935 	smc_copy_sock_settings_to_clc(smc);
936 	smc->connect_nonblock = 0;
937 	if (smc->sk.sk_state == SMC_INIT)
938 		smc->sk.sk_state = SMC_ACTIVE;
939 
940 	return 0;
941 connect_abort:
942 	smc_conn_abort(smc, ini->first_contact_local);
943 	mutex_unlock(&smc_server_lgr_pending);
944 	smc->connect_nonblock = 0;
945 
946 	return rc;
947 }
948 
949 /* check if received accept type and version matches a proposed one */
950 static int smc_connect_check_aclc(struct smc_init_info *ini,
951 				  struct smc_clc_msg_accept_confirm *aclc)
952 {
953 	if ((aclc->hdr.typev1 == SMC_TYPE_R &&
954 	     !smcr_indicated(ini->smc_type_v1)) ||
955 	    (aclc->hdr.typev1 == SMC_TYPE_D &&
956 	     ((!smcd_indicated(ini->smc_type_v1) &&
957 	       !smcd_indicated(ini->smc_type_v2)) ||
958 	      (aclc->hdr.version == SMC_V1 &&
959 	       !smcd_indicated(ini->smc_type_v1)) ||
960 	      (aclc->hdr.version == SMC_V2 &&
961 	       !smcd_indicated(ini->smc_type_v2)))))
962 		return SMC_CLC_DECL_MODEUNSUPP;
963 
964 	return 0;
965 }
966 
967 /* perform steps before actually connecting */
968 static int __smc_connect(struct smc_sock *smc)
969 {
970 	u8 version = smc_ism_is_v2_capable() ? SMC_V2 : SMC_V1;
971 	struct smc_clc_msg_accept_confirm_v2 *aclc2;
972 	struct smc_clc_msg_accept_confirm *aclc;
973 	struct smc_init_info *ini = NULL;
974 	u8 *buf = NULL;
975 	int rc = 0;
976 
977 	if (smc->use_fallback)
978 		return smc_connect_fallback(smc, smc->fallback_rsn);
979 
980 	/* if peer has not signalled SMC-capability, fall back */
981 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
982 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
983 
984 	/* IPSec connections opt out of SMC optimizations */
985 	if (using_ipsec(smc))
986 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC,
987 						    version);
988 
989 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
990 	if (!ini)
991 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_MEM,
992 						    version);
993 
994 	ini->smcd_version = SMC_V1;
995 	ini->smcd_version |= smc_ism_is_v2_capable() ? SMC_V2 : 0;
996 	ini->smc_type_v1 = SMC_TYPE_B;
997 	ini->smc_type_v2 = smc_ism_is_v2_capable() ? SMC_TYPE_D : SMC_TYPE_N;
998 
999 	/* get vlan id from IP device */
1000 	if (smc_vlan_by_tcpsk(smc->clcsock, ini)) {
1001 		ini->smcd_version &= ~SMC_V1;
1002 		ini->smc_type_v1 = SMC_TYPE_N;
1003 		if (!ini->smcd_version) {
1004 			rc = SMC_CLC_DECL_GETVLANERR;
1005 			goto fallback;
1006 		}
1007 	}
1008 
1009 	rc = smc_find_proposal_devices(smc, ini);
1010 	if (rc)
1011 		goto fallback;
1012 
1013 	buf = kzalloc(SMC_CLC_MAX_ACCEPT_LEN, GFP_KERNEL);
1014 	if (!buf) {
1015 		rc = SMC_CLC_DECL_MEM;
1016 		goto fallback;
1017 	}
1018 	aclc2 = (struct smc_clc_msg_accept_confirm_v2 *)buf;
1019 	aclc = (struct smc_clc_msg_accept_confirm *)aclc2;
1020 
1021 	/* perform CLC handshake */
1022 	rc = smc_connect_clc(smc, aclc2, ini);
1023 	if (rc)
1024 		goto vlan_cleanup;
1025 
1026 	/* check if smc modes and versions of CLC proposal and accept match */
1027 	rc = smc_connect_check_aclc(ini, aclc);
1028 	version = aclc->hdr.version == SMC_V1 ? SMC_V1 : SMC_V2;
1029 	ini->smcd_version = version;
1030 	if (rc)
1031 		goto vlan_cleanup;
1032 
1033 	/* depending on previous steps, connect using rdma or ism */
1034 	if (aclc->hdr.typev1 == SMC_TYPE_R)
1035 		rc = smc_connect_rdma(smc, aclc, ini);
1036 	else if (aclc->hdr.typev1 == SMC_TYPE_D)
1037 		rc = smc_connect_ism(smc, aclc, ini);
1038 	if (rc)
1039 		goto vlan_cleanup;
1040 
1041 	SMC_STAT_CLNT_SUCC_INC(sock_net(smc->clcsock->sk), aclc);
1042 	smc_connect_ism_vlan_cleanup(smc, ini);
1043 	kfree(buf);
1044 	kfree(ini);
1045 	return 0;
1046 
1047 vlan_cleanup:
1048 	smc_connect_ism_vlan_cleanup(smc, ini);
1049 	kfree(buf);
1050 fallback:
1051 	kfree(ini);
1052 	return smc_connect_decline_fallback(smc, rc, version);
1053 }
1054 
1055 static void smc_connect_work(struct work_struct *work)
1056 {
1057 	struct smc_sock *smc = container_of(work, struct smc_sock,
1058 					    connect_work);
1059 	long timeo = smc->sk.sk_sndtimeo;
1060 	int rc = 0;
1061 
1062 	if (!timeo)
1063 		timeo = MAX_SCHEDULE_TIMEOUT;
1064 	lock_sock(smc->clcsock->sk);
1065 	if (smc->clcsock->sk->sk_err) {
1066 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
1067 	} else if ((1 << smc->clcsock->sk->sk_state) &
1068 					(TCPF_SYN_SENT | TCP_SYN_RECV)) {
1069 		rc = sk_stream_wait_connect(smc->clcsock->sk, &timeo);
1070 		if ((rc == -EPIPE) &&
1071 		    ((1 << smc->clcsock->sk->sk_state) &
1072 					(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))
1073 			rc = 0;
1074 	}
1075 	release_sock(smc->clcsock->sk);
1076 	lock_sock(&smc->sk);
1077 	if (rc != 0 || smc->sk.sk_err) {
1078 		smc->sk.sk_state = SMC_CLOSED;
1079 		if (rc == -EPIPE || rc == -EAGAIN)
1080 			smc->sk.sk_err = EPIPE;
1081 		else if (signal_pending(current))
1082 			smc->sk.sk_err = -sock_intr_errno(timeo);
1083 		sock_put(&smc->sk); /* passive closing */
1084 		goto out;
1085 	}
1086 
1087 	rc = __smc_connect(smc);
1088 	if (rc < 0)
1089 		smc->sk.sk_err = -rc;
1090 
1091 out:
1092 	if (!sock_flag(&smc->sk, SOCK_DEAD)) {
1093 		if (smc->sk.sk_err) {
1094 			smc->sk.sk_state_change(&smc->sk);
1095 		} else { /* allow polling before and after fallback decision */
1096 			smc->clcsock->sk->sk_write_space(smc->clcsock->sk);
1097 			smc->sk.sk_write_space(&smc->sk);
1098 		}
1099 	}
1100 	release_sock(&smc->sk);
1101 }
1102 
1103 static int smc_connect(struct socket *sock, struct sockaddr *addr,
1104 		       int alen, int flags)
1105 {
1106 	struct sock *sk = sock->sk;
1107 	struct smc_sock *smc;
1108 	int rc = -EINVAL;
1109 
1110 	smc = smc_sk(sk);
1111 
1112 	/* separate smc parameter checking to be safe */
1113 	if (alen < sizeof(addr->sa_family))
1114 		goto out_err;
1115 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
1116 		goto out_err;
1117 
1118 	lock_sock(sk);
1119 	switch (sk->sk_state) {
1120 	default:
1121 		goto out;
1122 	case SMC_ACTIVE:
1123 		rc = -EISCONN;
1124 		goto out;
1125 	case SMC_INIT:
1126 		break;
1127 	}
1128 
1129 	smc_copy_sock_settings_to_clc(smc);
1130 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1131 	if (smc->connect_nonblock) {
1132 		rc = -EALREADY;
1133 		goto out;
1134 	}
1135 	rc = kernel_connect(smc->clcsock, addr, alen, flags);
1136 	if (rc && rc != -EINPROGRESS)
1137 		goto out;
1138 
1139 	sock_hold(&smc->sk); /* sock put in passive closing */
1140 	if (smc->use_fallback)
1141 		goto out;
1142 	if (flags & O_NONBLOCK) {
1143 		if (queue_work(smc_hs_wq, &smc->connect_work))
1144 			smc->connect_nonblock = 1;
1145 		rc = -EINPROGRESS;
1146 	} else {
1147 		rc = __smc_connect(smc);
1148 		if (rc < 0)
1149 			goto out;
1150 		else
1151 			rc = 0; /* success cases including fallback */
1152 	}
1153 
1154 out:
1155 	release_sock(sk);
1156 out_err:
1157 	return rc;
1158 }
1159 
1160 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
1161 {
1162 	struct socket *new_clcsock = NULL;
1163 	struct sock *lsk = &lsmc->sk;
1164 	struct sock *new_sk;
1165 	int rc = -EINVAL;
1166 
1167 	release_sock(lsk);
1168 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
1169 	if (!new_sk) {
1170 		rc = -ENOMEM;
1171 		lsk->sk_err = ENOMEM;
1172 		*new_smc = NULL;
1173 		lock_sock(lsk);
1174 		goto out;
1175 	}
1176 	*new_smc = smc_sk(new_sk);
1177 
1178 	mutex_lock(&lsmc->clcsock_release_lock);
1179 	if (lsmc->clcsock)
1180 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, SOCK_NONBLOCK);
1181 	mutex_unlock(&lsmc->clcsock_release_lock);
1182 	lock_sock(lsk);
1183 	if  (rc < 0 && rc != -EAGAIN)
1184 		lsk->sk_err = -rc;
1185 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
1186 		new_sk->sk_prot->unhash(new_sk);
1187 		if (new_clcsock)
1188 			sock_release(new_clcsock);
1189 		new_sk->sk_state = SMC_CLOSED;
1190 		sock_set_flag(new_sk, SOCK_DEAD);
1191 		sock_put(new_sk); /* final */
1192 		*new_smc = NULL;
1193 		goto out;
1194 	}
1195 
1196 	/* new clcsock has inherited the smc listen-specific sk_data_ready
1197 	 * function; switch it back to the original sk_data_ready function
1198 	 */
1199 	new_clcsock->sk->sk_data_ready = lsmc->clcsk_data_ready;
1200 	(*new_smc)->clcsock = new_clcsock;
1201 out:
1202 	return rc;
1203 }
1204 
1205 /* add a just created sock to the accept queue of the listen sock as
1206  * candidate for a following socket accept call from user space
1207  */
1208 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
1209 {
1210 	struct smc_sock *par = smc_sk(parent);
1211 
1212 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
1213 	spin_lock(&par->accept_q_lock);
1214 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
1215 	spin_unlock(&par->accept_q_lock);
1216 	sk_acceptq_added(parent);
1217 }
1218 
1219 /* remove a socket from the accept queue of its parental listening socket */
1220 static void smc_accept_unlink(struct sock *sk)
1221 {
1222 	struct smc_sock *par = smc_sk(sk)->listen_smc;
1223 
1224 	spin_lock(&par->accept_q_lock);
1225 	list_del_init(&smc_sk(sk)->accept_q);
1226 	spin_unlock(&par->accept_q_lock);
1227 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
1228 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
1229 }
1230 
1231 /* remove a sock from the accept queue to bind it to a new socket created
1232  * for a socket accept call from user space
1233  */
1234 struct sock *smc_accept_dequeue(struct sock *parent,
1235 				struct socket *new_sock)
1236 {
1237 	struct smc_sock *isk, *n;
1238 	struct sock *new_sk;
1239 
1240 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
1241 		new_sk = (struct sock *)isk;
1242 
1243 		smc_accept_unlink(new_sk);
1244 		if (new_sk->sk_state == SMC_CLOSED) {
1245 			new_sk->sk_prot->unhash(new_sk);
1246 			if (isk->clcsock) {
1247 				sock_release(isk->clcsock);
1248 				isk->clcsock = NULL;
1249 			}
1250 			sock_put(new_sk); /* final */
1251 			continue;
1252 		}
1253 		if (new_sock) {
1254 			sock_graft(new_sk, new_sock);
1255 			if (isk->use_fallback) {
1256 				smc_sk(new_sk)->clcsock->file = new_sock->file;
1257 				isk->clcsock->file->private_data = isk->clcsock;
1258 			}
1259 		}
1260 		return new_sk;
1261 	}
1262 	return NULL;
1263 }
1264 
1265 /* clean up for a created but never accepted sock */
1266 void smc_close_non_accepted(struct sock *sk)
1267 {
1268 	struct smc_sock *smc = smc_sk(sk);
1269 
1270 	sock_hold(sk); /* sock_put below */
1271 	lock_sock(sk);
1272 	if (!sk->sk_lingertime)
1273 		/* wait for peer closing */
1274 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
1275 	__smc_release(smc);
1276 	release_sock(sk);
1277 	sock_put(sk); /* sock_hold above */
1278 	sock_put(sk); /* final sock_put */
1279 }
1280 
1281 static int smcr_serv_conf_first_link(struct smc_sock *smc)
1282 {
1283 	struct smc_link *link = smc->conn.lnk;
1284 	struct smc_llc_qentry *qentry;
1285 	int rc;
1286 
1287 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc))
1288 		return SMC_CLC_DECL_ERR_REGRMB;
1289 
1290 	/* send CONFIRM LINK request to client over the RoCE fabric */
1291 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
1292 	if (rc < 0)
1293 		return SMC_CLC_DECL_TIMEOUT_CL;
1294 
1295 	/* receive CONFIRM LINK response from client over the RoCE fabric */
1296 	qentry = smc_llc_wait(link->lgr, link, SMC_LLC_WAIT_TIME,
1297 			      SMC_LLC_CONFIRM_LINK);
1298 	if (!qentry) {
1299 		struct smc_clc_msg_decline dclc;
1300 
1301 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1302 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1303 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
1304 	}
1305 	smc_llc_save_peer_uid(qentry);
1306 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_RESP);
1307 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
1308 	if (rc)
1309 		return SMC_CLC_DECL_RMBE_EC;
1310 
1311 	/* confirm_rkey is implicit on 1st contact */
1312 	smc->conn.rmb_desc->is_conf_rkey = true;
1313 
1314 	smc_llc_link_active(link);
1315 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
1316 
1317 	/* initial contact - try to establish second link */
1318 	smc_llc_srv_add_link(link);
1319 	return 0;
1320 }
1321 
1322 /* listen worker: finish */
1323 static void smc_listen_out(struct smc_sock *new_smc)
1324 {
1325 	struct smc_sock *lsmc = new_smc->listen_smc;
1326 	struct sock *newsmcsk = &new_smc->sk;
1327 
1328 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1329 		lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1330 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1331 		release_sock(&lsmc->sk);
1332 	} else { /* no longer listening */
1333 		smc_close_non_accepted(newsmcsk);
1334 	}
1335 
1336 	/* Wake up accept */
1337 	lsmc->sk.sk_data_ready(&lsmc->sk);
1338 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1339 }
1340 
1341 /* listen worker: finish in state connected */
1342 static void smc_listen_out_connected(struct smc_sock *new_smc)
1343 {
1344 	struct sock *newsmcsk = &new_smc->sk;
1345 
1346 	sk_refcnt_debug_inc(newsmcsk);
1347 	if (newsmcsk->sk_state == SMC_INIT)
1348 		newsmcsk->sk_state = SMC_ACTIVE;
1349 
1350 	smc_listen_out(new_smc);
1351 }
1352 
1353 /* listen worker: finish in error state */
1354 static void smc_listen_out_err(struct smc_sock *new_smc)
1355 {
1356 	struct sock *newsmcsk = &new_smc->sk;
1357 	struct net *net = sock_net(newsmcsk);
1358 
1359 	this_cpu_inc(net->smc.smc_stats->srv_hshake_err_cnt);
1360 	if (newsmcsk->sk_state == SMC_INIT)
1361 		sock_put(&new_smc->sk); /* passive closing */
1362 	newsmcsk->sk_state = SMC_CLOSED;
1363 
1364 	smc_listen_out(new_smc);
1365 }
1366 
1367 /* listen worker: decline and fall back if possible */
1368 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1369 			       int local_first, u8 version)
1370 {
1371 	/* RDMA setup failed, switch back to TCP */
1372 	smc_conn_abort(new_smc, local_first);
1373 	if (reason_code < 0) { /* error, no fallback possible */
1374 		smc_listen_out_err(new_smc);
1375 		return;
1376 	}
1377 	smc_switch_to_fallback(new_smc, reason_code);
1378 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1379 		if (smc_clc_send_decline(new_smc, reason_code, version) < 0) {
1380 			smc_listen_out_err(new_smc);
1381 			return;
1382 		}
1383 	}
1384 	smc_listen_out_connected(new_smc);
1385 }
1386 
1387 /* listen worker: version checking */
1388 static int smc_listen_v2_check(struct smc_sock *new_smc,
1389 			       struct smc_clc_msg_proposal *pclc,
1390 			       struct smc_init_info *ini)
1391 {
1392 	struct smc_clc_smcd_v2_extension *pclc_smcd_v2_ext;
1393 	struct smc_clc_v2_extension *pclc_v2_ext;
1394 	int rc = SMC_CLC_DECL_PEERNOSMC;
1395 
1396 	ini->smc_type_v1 = pclc->hdr.typev1;
1397 	ini->smc_type_v2 = pclc->hdr.typev2;
1398 	ini->smcd_version = ini->smc_type_v1 != SMC_TYPE_N ? SMC_V1 : 0;
1399 	if (pclc->hdr.version > SMC_V1)
1400 		ini->smcd_version |=
1401 				ini->smc_type_v2 != SMC_TYPE_N ? SMC_V2 : 0;
1402 	if (!(ini->smcd_version & SMC_V2)) {
1403 		rc = SMC_CLC_DECL_PEERNOSMC;
1404 		goto out;
1405 	}
1406 	if (!smc_ism_is_v2_capable()) {
1407 		ini->smcd_version &= ~SMC_V2;
1408 		rc = SMC_CLC_DECL_NOISM2SUPP;
1409 		goto out;
1410 	}
1411 	pclc_v2_ext = smc_get_clc_v2_ext(pclc);
1412 	if (!pclc_v2_ext) {
1413 		ini->smcd_version &= ~SMC_V2;
1414 		rc = SMC_CLC_DECL_NOV2EXT;
1415 		goto out;
1416 	}
1417 	pclc_smcd_v2_ext = smc_get_clc_smcd_v2_ext(pclc_v2_ext);
1418 	if (!pclc_smcd_v2_ext) {
1419 		ini->smcd_version &= ~SMC_V2;
1420 		rc = SMC_CLC_DECL_NOV2DEXT;
1421 	}
1422 
1423 out:
1424 	if (!ini->smcd_version)
1425 		return rc;
1426 
1427 	return 0;
1428 }
1429 
1430 /* listen worker: check prefixes */
1431 static int smc_listen_prfx_check(struct smc_sock *new_smc,
1432 				 struct smc_clc_msg_proposal *pclc)
1433 {
1434 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1435 	struct socket *newclcsock = new_smc->clcsock;
1436 
1437 	if (pclc->hdr.typev1 == SMC_TYPE_N)
1438 		return 0;
1439 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1440 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1441 		return SMC_CLC_DECL_DIFFPREFIX;
1442 
1443 	return 0;
1444 }
1445 
1446 /* listen worker: initialize connection and buffers */
1447 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1448 				struct smc_init_info *ini)
1449 {
1450 	int rc;
1451 
1452 	/* allocate connection / link group */
1453 	rc = smc_conn_create(new_smc, ini);
1454 	if (rc)
1455 		return rc;
1456 
1457 	/* create send buffer and rmb */
1458 	if (smc_buf_create(new_smc, false))
1459 		return SMC_CLC_DECL_MEM;
1460 
1461 	return 0;
1462 }
1463 
1464 /* listen worker: initialize connection and buffers for SMC-D */
1465 static int smc_listen_ism_init(struct smc_sock *new_smc,
1466 			       struct smc_init_info *ini)
1467 {
1468 	int rc;
1469 
1470 	rc = smc_conn_create(new_smc, ini);
1471 	if (rc)
1472 		return rc;
1473 
1474 	/* Create send and receive buffers */
1475 	rc = smc_buf_create(new_smc, true);
1476 	if (rc) {
1477 		smc_conn_abort(new_smc, ini->first_contact_local);
1478 		return (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB :
1479 					 SMC_CLC_DECL_MEM;
1480 	}
1481 
1482 	return 0;
1483 }
1484 
1485 static bool smc_is_already_selected(struct smcd_dev *smcd,
1486 				    struct smc_init_info *ini,
1487 				    int matches)
1488 {
1489 	int i;
1490 
1491 	for (i = 0; i < matches; i++)
1492 		if (smcd == ini->ism_dev[i])
1493 			return true;
1494 
1495 	return false;
1496 }
1497 
1498 /* check for ISM devices matching proposed ISM devices */
1499 static void smc_check_ism_v2_match(struct smc_init_info *ini,
1500 				   u16 proposed_chid, u64 proposed_gid,
1501 				   unsigned int *matches)
1502 {
1503 	struct smcd_dev *smcd;
1504 
1505 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
1506 		if (smcd->going_away)
1507 			continue;
1508 		if (smc_is_already_selected(smcd, ini, *matches))
1509 			continue;
1510 		if (smc_ism_get_chid(smcd) == proposed_chid &&
1511 		    !smc_ism_cantalk(proposed_gid, ISM_RESERVED_VLANID, smcd)) {
1512 			ini->ism_peer_gid[*matches] = proposed_gid;
1513 			ini->ism_dev[*matches] = smcd;
1514 			(*matches)++;
1515 			break;
1516 		}
1517 	}
1518 }
1519 
1520 static void smc_find_ism_store_rc(u32 rc, struct smc_init_info *ini)
1521 {
1522 	if (!ini->rc)
1523 		ini->rc = rc;
1524 }
1525 
1526 static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
1527 					struct smc_clc_msg_proposal *pclc,
1528 					struct smc_init_info *ini)
1529 {
1530 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
1531 	struct smc_clc_v2_extension *smc_v2_ext;
1532 	struct smc_clc_msg_smcd *pclc_smcd;
1533 	unsigned int matches = 0;
1534 	u8 smcd_version;
1535 	u8 *eid = NULL;
1536 	int i, rc;
1537 
1538 	if (!(ini->smcd_version & SMC_V2) || !smcd_indicated(ini->smc_type_v2))
1539 		goto not_found;
1540 
1541 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
1542 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
1543 	smcd_v2_ext = smc_get_clc_smcd_v2_ext(smc_v2_ext);
1544 	if (!smcd_v2_ext) {
1545 		smc_find_ism_store_rc(SMC_CLC_DECL_NOV2DEXT, ini);
1546 		goto not_found;
1547 	}
1548 
1549 	mutex_lock(&smcd_dev_list.mutex);
1550 	if (pclc_smcd->ism.chid)
1551 		/* check for ISM device matching proposed native ISM device */
1552 		smc_check_ism_v2_match(ini, ntohs(pclc_smcd->ism.chid),
1553 				       ntohll(pclc_smcd->ism.gid), &matches);
1554 	for (i = 1; i <= smc_v2_ext->hdr.ism_gid_cnt; i++) {
1555 		/* check for ISM devices matching proposed non-native ISM
1556 		 * devices
1557 		 */
1558 		smc_check_ism_v2_match(ini,
1559 				       ntohs(smcd_v2_ext->gidchid[i - 1].chid),
1560 				       ntohll(smcd_v2_ext->gidchid[i - 1].gid),
1561 				       &matches);
1562 	}
1563 	mutex_unlock(&smcd_dev_list.mutex);
1564 
1565 	if (!ini->ism_dev[0])
1566 		goto not_found;
1567 
1568 	smc_ism_get_system_eid(&eid);
1569 	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext,
1570 			       smcd_v2_ext->system_eid, eid))
1571 		goto not_found;
1572 
1573 	/* separate - outside the smcd_dev_list.lock */
1574 	smcd_version = ini->smcd_version;
1575 	for (i = 0; i < matches; i++) {
1576 		ini->smcd_version = SMC_V2;
1577 		ini->is_smcd = true;
1578 		ini->ism_selected = i;
1579 		rc = smc_listen_ism_init(new_smc, ini);
1580 		if (rc) {
1581 			smc_find_ism_store_rc(rc, ini);
1582 			/* try next active ISM device */
1583 			continue;
1584 		}
1585 		return; /* matching and usable V2 ISM device found */
1586 	}
1587 	/* no V2 ISM device could be initialized */
1588 	ini->smcd_version = smcd_version;	/* restore original value */
1589 	ini->negotiated_eid[0] = 0;
1590 
1591 not_found:
1592 	ini->smcd_version &= ~SMC_V2;
1593 	ini->ism_dev[0] = NULL;
1594 	ini->is_smcd = false;
1595 }
1596 
1597 static void smc_find_ism_v1_device_serv(struct smc_sock *new_smc,
1598 					struct smc_clc_msg_proposal *pclc,
1599 					struct smc_init_info *ini)
1600 {
1601 	struct smc_clc_msg_smcd *pclc_smcd = smc_get_clc_msg_smcd(pclc);
1602 	int rc = 0;
1603 
1604 	/* check if ISM V1 is available */
1605 	if (!(ini->smcd_version & SMC_V1) || !smcd_indicated(ini->smc_type_v1))
1606 		goto not_found;
1607 	ini->is_smcd = true; /* prepare ISM check */
1608 	ini->ism_peer_gid[0] = ntohll(pclc_smcd->ism.gid);
1609 	rc = smc_find_ism_device(new_smc, ini);
1610 	if (rc)
1611 		goto not_found;
1612 	ini->ism_selected = 0;
1613 	rc = smc_listen_ism_init(new_smc, ini);
1614 	if (!rc)
1615 		return;		/* V1 ISM device found */
1616 
1617 not_found:
1618 	smc_find_ism_store_rc(rc, ini);
1619 	ini->ism_dev[0] = NULL;
1620 	ini->is_smcd = false;
1621 }
1622 
1623 /* listen worker: register buffers */
1624 static int smc_listen_rdma_reg(struct smc_sock *new_smc, bool local_first)
1625 {
1626 	struct smc_connection *conn = &new_smc->conn;
1627 
1628 	if (!local_first) {
1629 		if (smcr_lgr_reg_rmbs(conn->lnk, conn->rmb_desc))
1630 			return SMC_CLC_DECL_ERR_REGRMB;
1631 	}
1632 	smc_rmb_sync_sg_for_device(&new_smc->conn);
1633 
1634 	return 0;
1635 }
1636 
1637 static int smc_find_rdma_v1_device_serv(struct smc_sock *new_smc,
1638 					struct smc_clc_msg_proposal *pclc,
1639 					struct smc_init_info *ini)
1640 {
1641 	int rc;
1642 
1643 	if (!smcr_indicated(ini->smc_type_v1))
1644 		return SMC_CLC_DECL_NOSMCDEV;
1645 
1646 	/* prepare RDMA check */
1647 	ini->ib_lcl = &pclc->lcl;
1648 	rc = smc_find_rdma_device(new_smc, ini);
1649 	if (rc) {
1650 		/* no RDMA device found */
1651 		if (ini->smc_type_v1 == SMC_TYPE_B)
1652 			/* neither ISM nor RDMA device found */
1653 			rc = SMC_CLC_DECL_NOSMCDEV;
1654 		return rc;
1655 	}
1656 	rc = smc_listen_rdma_init(new_smc, ini);
1657 	if (rc)
1658 		return rc;
1659 	return smc_listen_rdma_reg(new_smc, ini->first_contact_local);
1660 }
1661 
1662 /* determine the local device matching to proposal */
1663 static int smc_listen_find_device(struct smc_sock *new_smc,
1664 				  struct smc_clc_msg_proposal *pclc,
1665 				  struct smc_init_info *ini)
1666 {
1667 	int rc;
1668 
1669 	/* check for ISM device matching V2 proposed device */
1670 	smc_find_ism_v2_device_serv(new_smc, pclc, ini);
1671 	if (ini->ism_dev[0])
1672 		return 0;
1673 
1674 	if (!(ini->smcd_version & SMC_V1))
1675 		return ini->rc ?: SMC_CLC_DECL_NOSMCD2DEV;
1676 
1677 	/* check for matching IP prefix and subnet length */
1678 	rc = smc_listen_prfx_check(new_smc, pclc);
1679 	if (rc)
1680 		return ini->rc ?: rc;
1681 
1682 	/* get vlan id from IP device */
1683 	if (smc_vlan_by_tcpsk(new_smc->clcsock, ini))
1684 		return ini->rc ?: SMC_CLC_DECL_GETVLANERR;
1685 
1686 	/* check for ISM device matching V1 proposed device */
1687 	smc_find_ism_v1_device_serv(new_smc, pclc, ini);
1688 	if (ini->ism_dev[0])
1689 		return 0;
1690 
1691 	if (pclc->hdr.typev1 == SMC_TYPE_D)
1692 		/* skip RDMA and decline */
1693 		return ini->rc ?: SMC_CLC_DECL_NOSMCDDEV;
1694 
1695 	/* check if RDMA is available */
1696 	rc = smc_find_rdma_v1_device_serv(new_smc, pclc, ini);
1697 	smc_find_ism_store_rc(rc, ini);
1698 
1699 	return (!rc) ? 0 : ini->rc;
1700 }
1701 
1702 /* listen worker: finish RDMA setup */
1703 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
1704 				  struct smc_clc_msg_accept_confirm *cclc,
1705 				  bool local_first)
1706 {
1707 	struct smc_link *link = new_smc->conn.lnk;
1708 	int reason_code = 0;
1709 
1710 	if (local_first)
1711 		smc_link_save_peer_info(link, cclc);
1712 
1713 	if (smc_rmb_rtoken_handling(&new_smc->conn, link, cclc))
1714 		return SMC_CLC_DECL_ERR_RTOK;
1715 
1716 	if (local_first) {
1717 		if (smc_ib_ready_link(link))
1718 			return SMC_CLC_DECL_ERR_RDYLNK;
1719 		/* QP confirmation over RoCE fabric */
1720 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
1721 		reason_code = smcr_serv_conf_first_link(new_smc);
1722 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
1723 	}
1724 	return reason_code;
1725 }
1726 
1727 /* setup for connection of server */
1728 static void smc_listen_work(struct work_struct *work)
1729 {
1730 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
1731 						smc_listen_work);
1732 	u8 version = smc_ism_is_v2_capable() ? SMC_V2 : SMC_V1;
1733 	struct socket *newclcsock = new_smc->clcsock;
1734 	struct smc_clc_msg_accept_confirm *cclc;
1735 	struct smc_clc_msg_proposal_area *buf;
1736 	struct smc_clc_msg_proposal *pclc;
1737 	struct smc_init_info *ini = NULL;
1738 	int rc = 0;
1739 
1740 	if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
1741 		return smc_listen_out_err(new_smc);
1742 
1743 	if (new_smc->use_fallback) {
1744 		smc_listen_out_connected(new_smc);
1745 		return;
1746 	}
1747 
1748 	/* check if peer is smc capable */
1749 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
1750 		smc_switch_to_fallback(new_smc, SMC_CLC_DECL_PEERNOSMC);
1751 		smc_listen_out_connected(new_smc);
1752 		return;
1753 	}
1754 
1755 	/* do inband token exchange -
1756 	 * wait for and receive SMC Proposal CLC message
1757 	 */
1758 	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
1759 	if (!buf) {
1760 		rc = SMC_CLC_DECL_MEM;
1761 		goto out_decl;
1762 	}
1763 	pclc = (struct smc_clc_msg_proposal *)buf;
1764 	rc = smc_clc_wait_msg(new_smc, pclc, sizeof(*buf),
1765 			      SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
1766 	if (rc)
1767 		goto out_decl;
1768 	version = pclc->hdr.version == SMC_V1 ? SMC_V1 : version;
1769 
1770 	/* IPSec connections opt out of SMC optimizations */
1771 	if (using_ipsec(new_smc)) {
1772 		rc = SMC_CLC_DECL_IPSEC;
1773 		goto out_decl;
1774 	}
1775 
1776 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1777 	if (!ini) {
1778 		rc = SMC_CLC_DECL_MEM;
1779 		goto out_decl;
1780 	}
1781 
1782 	/* initial version checking */
1783 	rc = smc_listen_v2_check(new_smc, pclc, ini);
1784 	if (rc)
1785 		goto out_decl;
1786 
1787 	mutex_lock(&smc_server_lgr_pending);
1788 	smc_close_init(new_smc);
1789 	smc_rx_init(new_smc);
1790 	smc_tx_init(new_smc);
1791 
1792 	/* determine ISM or RoCE device used for connection */
1793 	rc = smc_listen_find_device(new_smc, pclc, ini);
1794 	if (rc)
1795 		goto out_unlock;
1796 
1797 	/* send SMC Accept CLC message */
1798 	rc = smc_clc_send_accept(new_smc, ini->first_contact_local,
1799 				 ini->smcd_version == SMC_V2 ? SMC_V2 : SMC_V1,
1800 				 ini->negotiated_eid);
1801 	if (rc)
1802 		goto out_unlock;
1803 
1804 	/* SMC-D does not need this lock any more */
1805 	if (ini->is_smcd)
1806 		mutex_unlock(&smc_server_lgr_pending);
1807 
1808 	/* receive SMC Confirm CLC message */
1809 	memset(buf, 0, sizeof(*buf));
1810 	cclc = (struct smc_clc_msg_accept_confirm *)buf;
1811 	rc = smc_clc_wait_msg(new_smc, cclc, sizeof(*buf),
1812 			      SMC_CLC_CONFIRM, CLC_WAIT_TIME);
1813 	if (rc) {
1814 		if (!ini->is_smcd)
1815 			goto out_unlock;
1816 		goto out_decl;
1817 	}
1818 
1819 	/* finish worker */
1820 	if (!ini->is_smcd) {
1821 		rc = smc_listen_rdma_finish(new_smc, cclc,
1822 					    ini->first_contact_local);
1823 		if (rc)
1824 			goto out_unlock;
1825 		mutex_unlock(&smc_server_lgr_pending);
1826 	}
1827 	smc_conn_save_peer_info(new_smc, cclc);
1828 	smc_listen_out_connected(new_smc);
1829 	SMC_STAT_SERV_SUCC_INC(sock_net(newclcsock->sk), ini);
1830 	goto out_free;
1831 
1832 out_unlock:
1833 	mutex_unlock(&smc_server_lgr_pending);
1834 out_decl:
1835 	smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0,
1836 			   version);
1837 out_free:
1838 	kfree(ini);
1839 	kfree(buf);
1840 }
1841 
1842 static void smc_tcp_listen_work(struct work_struct *work)
1843 {
1844 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
1845 					     tcp_listen_work);
1846 	struct sock *lsk = &lsmc->sk;
1847 	struct smc_sock *new_smc;
1848 	int rc = 0;
1849 
1850 	lock_sock(lsk);
1851 	while (lsk->sk_state == SMC_LISTEN) {
1852 		rc = smc_clcsock_accept(lsmc, &new_smc);
1853 		if (rc) /* clcsock accept queue empty or error */
1854 			goto out;
1855 		if (!new_smc)
1856 			continue;
1857 
1858 		new_smc->listen_smc = lsmc;
1859 		new_smc->use_fallback = lsmc->use_fallback;
1860 		new_smc->fallback_rsn = lsmc->fallback_rsn;
1861 		sock_hold(lsk); /* sock_put in smc_listen_work */
1862 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
1863 		smc_copy_sock_settings_to_smc(new_smc);
1864 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
1865 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
1866 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
1867 		if (!queue_work(smc_hs_wq, &new_smc->smc_listen_work))
1868 			sock_put(&new_smc->sk);
1869 	}
1870 
1871 out:
1872 	release_sock(lsk);
1873 	sock_put(&lsmc->sk); /* sock_hold in smc_clcsock_data_ready() */
1874 }
1875 
1876 static void smc_clcsock_data_ready(struct sock *listen_clcsock)
1877 {
1878 	struct smc_sock *lsmc;
1879 
1880 	lsmc = (struct smc_sock *)
1881 	       ((uintptr_t)listen_clcsock->sk_user_data & ~SK_USER_DATA_NOCOPY);
1882 	if (!lsmc)
1883 		return;
1884 	lsmc->clcsk_data_ready(listen_clcsock);
1885 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1886 		sock_hold(&lsmc->sk); /* sock_put in smc_tcp_listen_work() */
1887 		if (!queue_work(smc_hs_wq, &lsmc->tcp_listen_work))
1888 			sock_put(&lsmc->sk);
1889 	}
1890 }
1891 
1892 static int smc_listen(struct socket *sock, int backlog)
1893 {
1894 	struct sock *sk = sock->sk;
1895 	struct smc_sock *smc;
1896 	int rc;
1897 
1898 	smc = smc_sk(sk);
1899 	lock_sock(sk);
1900 
1901 	rc = -EINVAL;
1902 	if ((sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) ||
1903 	    smc->connect_nonblock)
1904 		goto out;
1905 
1906 	rc = 0;
1907 	if (sk->sk_state == SMC_LISTEN) {
1908 		sk->sk_max_ack_backlog = backlog;
1909 		goto out;
1910 	}
1911 	/* some socket options are handled in core, so we could not apply
1912 	 * them to the clc socket -- copy smc socket options to clc socket
1913 	 */
1914 	smc_copy_sock_settings_to_clc(smc);
1915 	if (!smc->use_fallback)
1916 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1917 
1918 	/* save original sk_data_ready function and establish
1919 	 * smc-specific sk_data_ready function
1920 	 */
1921 	smc->clcsk_data_ready = smc->clcsock->sk->sk_data_ready;
1922 	smc->clcsock->sk->sk_data_ready = smc_clcsock_data_ready;
1923 	smc->clcsock->sk->sk_user_data =
1924 		(void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
1925 	rc = kernel_listen(smc->clcsock, backlog);
1926 	if (rc)
1927 		goto out;
1928 	sk->sk_max_ack_backlog = backlog;
1929 	sk->sk_ack_backlog = 0;
1930 	sk->sk_state = SMC_LISTEN;
1931 
1932 out:
1933 	release_sock(sk);
1934 	return rc;
1935 }
1936 
1937 static int smc_accept(struct socket *sock, struct socket *new_sock,
1938 		      int flags, bool kern)
1939 {
1940 	struct sock *sk = sock->sk, *nsk;
1941 	DECLARE_WAITQUEUE(wait, current);
1942 	struct smc_sock *lsmc;
1943 	long timeo;
1944 	int rc = 0;
1945 
1946 	lsmc = smc_sk(sk);
1947 	sock_hold(sk); /* sock_put below */
1948 	lock_sock(sk);
1949 
1950 	if (lsmc->sk.sk_state != SMC_LISTEN) {
1951 		rc = -EINVAL;
1952 		release_sock(sk);
1953 		goto out;
1954 	}
1955 
1956 	/* Wait for an incoming connection */
1957 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1958 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
1959 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1960 		set_current_state(TASK_INTERRUPTIBLE);
1961 		if (!timeo) {
1962 			rc = -EAGAIN;
1963 			break;
1964 		}
1965 		release_sock(sk);
1966 		timeo = schedule_timeout(timeo);
1967 		/* wakeup by sk_data_ready in smc_listen_work() */
1968 		sched_annotate_sleep();
1969 		lock_sock(sk);
1970 		if (signal_pending(current)) {
1971 			rc = sock_intr_errno(timeo);
1972 			break;
1973 		}
1974 	}
1975 	set_current_state(TASK_RUNNING);
1976 	remove_wait_queue(sk_sleep(sk), &wait);
1977 
1978 	if (!rc)
1979 		rc = sock_error(nsk);
1980 	release_sock(sk);
1981 	if (rc)
1982 		goto out;
1983 
1984 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
1985 		/* wait till data arrives on the socket */
1986 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
1987 								MSEC_PER_SEC);
1988 		if (smc_sk(nsk)->use_fallback) {
1989 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
1990 
1991 			lock_sock(clcsk);
1992 			if (skb_queue_empty(&clcsk->sk_receive_queue))
1993 				sk_wait_data(clcsk, &timeo, NULL);
1994 			release_sock(clcsk);
1995 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
1996 			lock_sock(nsk);
1997 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
1998 			release_sock(nsk);
1999 		}
2000 	}
2001 
2002 out:
2003 	sock_put(sk); /* sock_hold above */
2004 	return rc;
2005 }
2006 
2007 static int smc_getname(struct socket *sock, struct sockaddr *addr,
2008 		       int peer)
2009 {
2010 	struct smc_sock *smc;
2011 
2012 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
2013 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
2014 		return -ENOTCONN;
2015 
2016 	smc = smc_sk(sock->sk);
2017 
2018 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
2019 }
2020 
2021 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2022 {
2023 	struct sock *sk = sock->sk;
2024 	struct smc_sock *smc;
2025 	int rc = -EPIPE;
2026 
2027 	smc = smc_sk(sk);
2028 	lock_sock(sk);
2029 	if ((sk->sk_state != SMC_ACTIVE) &&
2030 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2031 	    (sk->sk_state != SMC_INIT))
2032 		goto out;
2033 
2034 	if (msg->msg_flags & MSG_FASTOPEN) {
2035 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2036 			smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2037 		} else {
2038 			rc = -EINVAL;
2039 			goto out;
2040 		}
2041 	}
2042 
2043 	if (smc->use_fallback) {
2044 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
2045 	} else {
2046 		rc = smc_tx_sendmsg(smc, msg, len);
2047 		SMC_STAT_TX_PAYLOAD(smc, len, rc);
2048 	}
2049 out:
2050 	release_sock(sk);
2051 	return rc;
2052 }
2053 
2054 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2055 		       int flags)
2056 {
2057 	struct sock *sk = sock->sk;
2058 	struct smc_sock *smc;
2059 	int rc = -ENOTCONN;
2060 
2061 	smc = smc_sk(sk);
2062 	lock_sock(sk);
2063 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2064 		/* socket was connected before, no more data to read */
2065 		rc = 0;
2066 		goto out;
2067 	}
2068 	if ((sk->sk_state == SMC_INIT) ||
2069 	    (sk->sk_state == SMC_LISTEN) ||
2070 	    (sk->sk_state == SMC_CLOSED))
2071 		goto out;
2072 
2073 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2074 		rc = 0;
2075 		goto out;
2076 	}
2077 
2078 	if (smc->use_fallback) {
2079 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
2080 	} else {
2081 		msg->msg_namelen = 0;
2082 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
2083 		SMC_STAT_RX_PAYLOAD(smc, rc, rc);
2084 	}
2085 
2086 out:
2087 	release_sock(sk);
2088 	return rc;
2089 }
2090 
2091 static __poll_t smc_accept_poll(struct sock *parent)
2092 {
2093 	struct smc_sock *isk = smc_sk(parent);
2094 	__poll_t mask = 0;
2095 
2096 	spin_lock(&isk->accept_q_lock);
2097 	if (!list_empty(&isk->accept_q))
2098 		mask = EPOLLIN | EPOLLRDNORM;
2099 	spin_unlock(&isk->accept_q_lock);
2100 
2101 	return mask;
2102 }
2103 
2104 static __poll_t smc_poll(struct file *file, struct socket *sock,
2105 			     poll_table *wait)
2106 {
2107 	struct sock *sk = sock->sk;
2108 	struct smc_sock *smc;
2109 	__poll_t mask = 0;
2110 
2111 	if (!sk)
2112 		return EPOLLNVAL;
2113 
2114 	smc = smc_sk(sock->sk);
2115 	if (smc->use_fallback) {
2116 		/* delegate to CLC child sock */
2117 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
2118 		sk->sk_err = smc->clcsock->sk->sk_err;
2119 	} else {
2120 		if (sk->sk_state != SMC_CLOSED)
2121 			sock_poll_wait(file, sock, wait);
2122 		if (sk->sk_err)
2123 			mask |= EPOLLERR;
2124 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
2125 		    (sk->sk_state == SMC_CLOSED))
2126 			mask |= EPOLLHUP;
2127 		if (sk->sk_state == SMC_LISTEN) {
2128 			/* woken up by sk_data_ready in smc_listen_work() */
2129 			mask |= smc_accept_poll(sk);
2130 		} else if (smc->use_fallback) { /* as result of connect_work()*/
2131 			mask |= smc->clcsock->ops->poll(file, smc->clcsock,
2132 							   wait);
2133 			sk->sk_err = smc->clcsock->sk->sk_err;
2134 		} else {
2135 			if ((sk->sk_state != SMC_INIT &&
2136 			     atomic_read(&smc->conn.sndbuf_space)) ||
2137 			    sk->sk_shutdown & SEND_SHUTDOWN) {
2138 				mask |= EPOLLOUT | EPOLLWRNORM;
2139 			} else {
2140 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2141 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2142 			}
2143 			if (atomic_read(&smc->conn.bytes_to_rcv))
2144 				mask |= EPOLLIN | EPOLLRDNORM;
2145 			if (sk->sk_shutdown & RCV_SHUTDOWN)
2146 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
2147 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
2148 				mask |= EPOLLIN;
2149 			if (smc->conn.urg_state == SMC_URG_VALID)
2150 				mask |= EPOLLPRI;
2151 		}
2152 	}
2153 
2154 	return mask;
2155 }
2156 
2157 static int smc_shutdown(struct socket *sock, int how)
2158 {
2159 	struct sock *sk = sock->sk;
2160 	struct smc_sock *smc;
2161 	int rc = -EINVAL;
2162 	int rc1 = 0;
2163 
2164 	smc = smc_sk(sk);
2165 
2166 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
2167 		return rc;
2168 
2169 	lock_sock(sk);
2170 
2171 	rc = -ENOTCONN;
2172 	if ((sk->sk_state != SMC_ACTIVE) &&
2173 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
2174 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
2175 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2176 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
2177 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
2178 		goto out;
2179 	if (smc->use_fallback) {
2180 		rc = kernel_sock_shutdown(smc->clcsock, how);
2181 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
2182 		if (sk->sk_shutdown == SHUTDOWN_MASK)
2183 			sk->sk_state = SMC_CLOSED;
2184 		goto out;
2185 	}
2186 	switch (how) {
2187 	case SHUT_RDWR:		/* shutdown in both directions */
2188 		rc = smc_close_active(smc);
2189 		break;
2190 	case SHUT_WR:
2191 		rc = smc_close_shutdown_write(smc);
2192 		break;
2193 	case SHUT_RD:
2194 		rc = 0;
2195 		/* nothing more to do because peer is not involved */
2196 		break;
2197 	}
2198 	if (smc->clcsock)
2199 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
2200 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
2201 	sk->sk_shutdown |= how + 1;
2202 
2203 out:
2204 	release_sock(sk);
2205 	return rc ? rc : rc1;
2206 }
2207 
2208 static int smc_setsockopt(struct socket *sock, int level, int optname,
2209 			  sockptr_t optval, unsigned int optlen)
2210 {
2211 	struct sock *sk = sock->sk;
2212 	struct smc_sock *smc;
2213 	int val, rc;
2214 
2215 	if (level == SOL_TCP && optname == TCP_ULP)
2216 		return -EOPNOTSUPP;
2217 
2218 	smc = smc_sk(sk);
2219 
2220 	/* generic setsockopts reaching us here always apply to the
2221 	 * CLC socket
2222 	 */
2223 	if (unlikely(!smc->clcsock->ops->setsockopt))
2224 		rc = -EOPNOTSUPP;
2225 	else
2226 		rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
2227 						   optval, optlen);
2228 	if (smc->clcsock->sk->sk_err) {
2229 		sk->sk_err = smc->clcsock->sk->sk_err;
2230 		sk_error_report(sk);
2231 	}
2232 
2233 	if (optlen < sizeof(int))
2234 		return -EINVAL;
2235 	if (copy_from_sockptr(&val, optval, sizeof(int)))
2236 		return -EFAULT;
2237 
2238 	lock_sock(sk);
2239 	if (rc || smc->use_fallback)
2240 		goto out;
2241 	switch (optname) {
2242 	case TCP_FASTOPEN:
2243 	case TCP_FASTOPEN_CONNECT:
2244 	case TCP_FASTOPEN_KEY:
2245 	case TCP_FASTOPEN_NO_COOKIE:
2246 		/* option not supported by SMC */
2247 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2248 			smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2249 		} else {
2250 			rc = -EINVAL;
2251 		}
2252 		break;
2253 	case TCP_NODELAY:
2254 		if (sk->sk_state != SMC_INIT &&
2255 		    sk->sk_state != SMC_LISTEN &&
2256 		    sk->sk_state != SMC_CLOSED) {
2257 			if (val) {
2258 				SMC_STAT_INC(smc, ndly_cnt);
2259 				mod_delayed_work(smc->conn.lgr->tx_wq,
2260 						 &smc->conn.tx_work, 0);
2261 			}
2262 		}
2263 		break;
2264 	case TCP_CORK:
2265 		if (sk->sk_state != SMC_INIT &&
2266 		    sk->sk_state != SMC_LISTEN &&
2267 		    sk->sk_state != SMC_CLOSED) {
2268 			if (!val) {
2269 				SMC_STAT_INC(smc, cork_cnt);
2270 				mod_delayed_work(smc->conn.lgr->tx_wq,
2271 						 &smc->conn.tx_work, 0);
2272 			}
2273 		}
2274 		break;
2275 	case TCP_DEFER_ACCEPT:
2276 		smc->sockopt_defer_accept = val;
2277 		break;
2278 	default:
2279 		break;
2280 	}
2281 out:
2282 	release_sock(sk);
2283 
2284 	return rc;
2285 }
2286 
2287 static int smc_getsockopt(struct socket *sock, int level, int optname,
2288 			  char __user *optval, int __user *optlen)
2289 {
2290 	struct smc_sock *smc;
2291 
2292 	smc = smc_sk(sock->sk);
2293 	/* socket options apply to the CLC socket */
2294 	if (unlikely(!smc->clcsock->ops->getsockopt))
2295 		return -EOPNOTSUPP;
2296 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
2297 					     optval, optlen);
2298 }
2299 
2300 static int smc_ioctl(struct socket *sock, unsigned int cmd,
2301 		     unsigned long arg)
2302 {
2303 	union smc_host_cursor cons, urg;
2304 	struct smc_connection *conn;
2305 	struct smc_sock *smc;
2306 	int answ;
2307 
2308 	smc = smc_sk(sock->sk);
2309 	conn = &smc->conn;
2310 	lock_sock(&smc->sk);
2311 	if (smc->use_fallback) {
2312 		if (!smc->clcsock) {
2313 			release_sock(&smc->sk);
2314 			return -EBADF;
2315 		}
2316 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
2317 		release_sock(&smc->sk);
2318 		return answ;
2319 	}
2320 	switch (cmd) {
2321 	case SIOCINQ: /* same as FIONREAD */
2322 		if (smc->sk.sk_state == SMC_LISTEN) {
2323 			release_sock(&smc->sk);
2324 			return -EINVAL;
2325 		}
2326 		if (smc->sk.sk_state == SMC_INIT ||
2327 		    smc->sk.sk_state == SMC_CLOSED)
2328 			answ = 0;
2329 		else
2330 			answ = atomic_read(&smc->conn.bytes_to_rcv);
2331 		break;
2332 	case SIOCOUTQ:
2333 		/* output queue size (not send + not acked) */
2334 		if (smc->sk.sk_state == SMC_LISTEN) {
2335 			release_sock(&smc->sk);
2336 			return -EINVAL;
2337 		}
2338 		if (smc->sk.sk_state == SMC_INIT ||
2339 		    smc->sk.sk_state == SMC_CLOSED)
2340 			answ = 0;
2341 		else
2342 			answ = smc->conn.sndbuf_desc->len -
2343 					atomic_read(&smc->conn.sndbuf_space);
2344 		break;
2345 	case SIOCOUTQNSD:
2346 		/* output queue size (not send only) */
2347 		if (smc->sk.sk_state == SMC_LISTEN) {
2348 			release_sock(&smc->sk);
2349 			return -EINVAL;
2350 		}
2351 		if (smc->sk.sk_state == SMC_INIT ||
2352 		    smc->sk.sk_state == SMC_CLOSED)
2353 			answ = 0;
2354 		else
2355 			answ = smc_tx_prepared_sends(&smc->conn);
2356 		break;
2357 	case SIOCATMARK:
2358 		if (smc->sk.sk_state == SMC_LISTEN) {
2359 			release_sock(&smc->sk);
2360 			return -EINVAL;
2361 		}
2362 		if (smc->sk.sk_state == SMC_INIT ||
2363 		    smc->sk.sk_state == SMC_CLOSED) {
2364 			answ = 0;
2365 		} else {
2366 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
2367 			smc_curs_copy(&urg, &conn->urg_curs, conn);
2368 			answ = smc_curs_diff(conn->rmb_desc->len,
2369 					     &cons, &urg) == 1;
2370 		}
2371 		break;
2372 	default:
2373 		release_sock(&smc->sk);
2374 		return -ENOIOCTLCMD;
2375 	}
2376 	release_sock(&smc->sk);
2377 
2378 	return put_user(answ, (int __user *)arg);
2379 }
2380 
2381 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
2382 			    int offset, size_t size, int flags)
2383 {
2384 	struct sock *sk = sock->sk;
2385 	struct smc_sock *smc;
2386 	int rc = -EPIPE;
2387 
2388 	smc = smc_sk(sk);
2389 	lock_sock(sk);
2390 	if (sk->sk_state != SMC_ACTIVE) {
2391 		release_sock(sk);
2392 		goto out;
2393 	}
2394 	release_sock(sk);
2395 	if (smc->use_fallback) {
2396 		rc = kernel_sendpage(smc->clcsock, page, offset,
2397 				     size, flags);
2398 	} else {
2399 		SMC_STAT_INC(smc, sendpage_cnt);
2400 		rc = sock_no_sendpage(sock, page, offset, size, flags);
2401 	}
2402 
2403 out:
2404 	return rc;
2405 }
2406 
2407 /* Map the affected portions of the rmbe into an spd, note the number of bytes
2408  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
2409  * updates till whenever a respective page has been fully processed.
2410  * Note that subsequent recv() calls have to wait till all splice() processing
2411  * completed.
2412  */
2413 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
2414 			       struct pipe_inode_info *pipe, size_t len,
2415 			       unsigned int flags)
2416 {
2417 	struct sock *sk = sock->sk;
2418 	struct smc_sock *smc;
2419 	int rc = -ENOTCONN;
2420 
2421 	smc = smc_sk(sk);
2422 	lock_sock(sk);
2423 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2424 		/* socket was connected before, no more data to read */
2425 		rc = 0;
2426 		goto out;
2427 	}
2428 	if (sk->sk_state == SMC_INIT ||
2429 	    sk->sk_state == SMC_LISTEN ||
2430 	    sk->sk_state == SMC_CLOSED)
2431 		goto out;
2432 
2433 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2434 		rc = 0;
2435 		goto out;
2436 	}
2437 
2438 	if (smc->use_fallback) {
2439 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
2440 						    pipe, len, flags);
2441 	} else {
2442 		if (*ppos) {
2443 			rc = -ESPIPE;
2444 			goto out;
2445 		}
2446 		if (flags & SPLICE_F_NONBLOCK)
2447 			flags = MSG_DONTWAIT;
2448 		else
2449 			flags = 0;
2450 		SMC_STAT_INC(smc, splice_cnt);
2451 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
2452 	}
2453 out:
2454 	release_sock(sk);
2455 
2456 	return rc;
2457 }
2458 
2459 /* must look like tcp */
2460 static const struct proto_ops smc_sock_ops = {
2461 	.family		= PF_SMC,
2462 	.owner		= THIS_MODULE,
2463 	.release	= smc_release,
2464 	.bind		= smc_bind,
2465 	.connect	= smc_connect,
2466 	.socketpair	= sock_no_socketpair,
2467 	.accept		= smc_accept,
2468 	.getname	= smc_getname,
2469 	.poll		= smc_poll,
2470 	.ioctl		= smc_ioctl,
2471 	.listen		= smc_listen,
2472 	.shutdown	= smc_shutdown,
2473 	.setsockopt	= smc_setsockopt,
2474 	.getsockopt	= smc_getsockopt,
2475 	.sendmsg	= smc_sendmsg,
2476 	.recvmsg	= smc_recvmsg,
2477 	.mmap		= sock_no_mmap,
2478 	.sendpage	= smc_sendpage,
2479 	.splice_read	= smc_splice_read,
2480 };
2481 
2482 static int smc_create(struct net *net, struct socket *sock, int protocol,
2483 		      int kern)
2484 {
2485 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
2486 	struct smc_sock *smc;
2487 	struct sock *sk;
2488 	int rc;
2489 
2490 	rc = -ESOCKTNOSUPPORT;
2491 	if (sock->type != SOCK_STREAM)
2492 		goto out;
2493 
2494 	rc = -EPROTONOSUPPORT;
2495 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
2496 		goto out;
2497 
2498 	rc = -ENOBUFS;
2499 	sock->ops = &smc_sock_ops;
2500 	sk = smc_sock_alloc(net, sock, protocol);
2501 	if (!sk)
2502 		goto out;
2503 
2504 	/* create internal TCP socket for CLC handshake and fallback */
2505 	smc = smc_sk(sk);
2506 	smc->use_fallback = false; /* assume rdma capability first */
2507 	smc->fallback_rsn = 0;
2508 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
2509 			      &smc->clcsock);
2510 	if (rc) {
2511 		sk_common_release(sk);
2512 		goto out;
2513 	}
2514 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
2515 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
2516 
2517 out:
2518 	return rc;
2519 }
2520 
2521 static const struct net_proto_family smc_sock_family_ops = {
2522 	.family	= PF_SMC,
2523 	.owner	= THIS_MODULE,
2524 	.create	= smc_create,
2525 };
2526 
2527 unsigned int smc_net_id;
2528 
2529 static __net_init int smc_net_init(struct net *net)
2530 {
2531 	return smc_pnet_net_init(net);
2532 }
2533 
2534 static void __net_exit smc_net_exit(struct net *net)
2535 {
2536 	smc_pnet_net_exit(net);
2537 }
2538 
2539 static __net_init int smc_net_stat_init(struct net *net)
2540 {
2541 	return smc_stats_init(net);
2542 }
2543 
2544 static void __net_exit smc_net_stat_exit(struct net *net)
2545 {
2546 	smc_stats_exit(net);
2547 }
2548 
2549 static struct pernet_operations smc_net_ops = {
2550 	.init = smc_net_init,
2551 	.exit = smc_net_exit,
2552 	.id   = &smc_net_id,
2553 	.size = sizeof(struct smc_net),
2554 };
2555 
2556 static struct pernet_operations smc_net_stat_ops = {
2557 	.init = smc_net_stat_init,
2558 	.exit = smc_net_stat_exit,
2559 };
2560 
2561 static int __init smc_init(void)
2562 {
2563 	int rc;
2564 
2565 	rc = register_pernet_subsys(&smc_net_ops);
2566 	if (rc)
2567 		return rc;
2568 
2569 	rc = register_pernet_subsys(&smc_net_stat_ops);
2570 	if (rc)
2571 		return rc;
2572 
2573 	smc_ism_init();
2574 	smc_clc_init();
2575 
2576 	rc = smc_nl_init();
2577 	if (rc)
2578 		goto out_pernet_subsys;
2579 
2580 	rc = smc_pnet_init();
2581 	if (rc)
2582 		goto out_nl;
2583 
2584 	rc = -ENOMEM;
2585 	smc_hs_wq = alloc_workqueue("smc_hs_wq", 0, 0);
2586 	if (!smc_hs_wq)
2587 		goto out_pnet;
2588 
2589 	smc_close_wq = alloc_workqueue("smc_close_wq", 0, 0);
2590 	if (!smc_close_wq)
2591 		goto out_alloc_hs_wq;
2592 
2593 	rc = smc_core_init();
2594 	if (rc) {
2595 		pr_err("%s: smc_core_init fails with %d\n", __func__, rc);
2596 		goto out_alloc_wqs;
2597 	}
2598 
2599 	rc = smc_llc_init();
2600 	if (rc) {
2601 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
2602 		goto out_core;
2603 	}
2604 
2605 	rc = smc_cdc_init();
2606 	if (rc) {
2607 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
2608 		goto out_core;
2609 	}
2610 
2611 	rc = proto_register(&smc_proto, 1);
2612 	if (rc) {
2613 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
2614 		goto out_core;
2615 	}
2616 
2617 	rc = proto_register(&smc_proto6, 1);
2618 	if (rc) {
2619 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
2620 		goto out_proto;
2621 	}
2622 
2623 	rc = sock_register(&smc_sock_family_ops);
2624 	if (rc) {
2625 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
2626 		goto out_proto6;
2627 	}
2628 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
2629 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
2630 
2631 	rc = smc_ib_register_client();
2632 	if (rc) {
2633 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
2634 		goto out_sock;
2635 	}
2636 
2637 	static_branch_enable(&tcp_have_smc);
2638 	return 0;
2639 
2640 out_sock:
2641 	sock_unregister(PF_SMC);
2642 out_proto6:
2643 	proto_unregister(&smc_proto6);
2644 out_proto:
2645 	proto_unregister(&smc_proto);
2646 out_core:
2647 	smc_core_exit();
2648 out_alloc_wqs:
2649 	destroy_workqueue(smc_close_wq);
2650 out_alloc_hs_wq:
2651 	destroy_workqueue(smc_hs_wq);
2652 out_pnet:
2653 	smc_pnet_exit();
2654 out_nl:
2655 	smc_nl_exit();
2656 out_pernet_subsys:
2657 	unregister_pernet_subsys(&smc_net_ops);
2658 
2659 	return rc;
2660 }
2661 
2662 static void __exit smc_exit(void)
2663 {
2664 	static_branch_disable(&tcp_have_smc);
2665 	sock_unregister(PF_SMC);
2666 	smc_core_exit();
2667 	smc_ib_unregister_client();
2668 	destroy_workqueue(smc_close_wq);
2669 	destroy_workqueue(smc_hs_wq);
2670 	proto_unregister(&smc_proto6);
2671 	proto_unregister(&smc_proto);
2672 	smc_pnet_exit();
2673 	smc_nl_exit();
2674 	smc_clc_exit();
2675 	unregister_pernet_subsys(&smc_net_stat_ops);
2676 	unregister_pernet_subsys(&smc_net_ops);
2677 	rcu_barrier();
2678 }
2679 
2680 module_init(smc_init);
2681 module_exit(smc_exit);
2682 
2683 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
2684 MODULE_DESCRIPTION("smc socket address family");
2685 MODULE_LICENSE("GPL");
2686 MODULE_ALIAS_NETPROTO(PF_SMC);
2687