xref: /linux/net/smc/af_smc.c (revision ea8a163e02d6925773129e2dd86e419e491b791d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
4  *
5  *  AF_SMC protocol family socket handler keeping the AF_INET sock address type
6  *  applies to SOCK_STREAM sockets only
7  *  offers an alternative communication option for TCP-protocol sockets
8  *  applicable with RoCE-cards only
9  *
10  *  Initial restrictions:
11  *    - support for alternate links postponed
12  *
13  *  Copyright IBM Corp. 2016, 2018
14  *
15  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
16  *              based on prototype from Frank Blaschka
17  */
18 
19 #define KMSG_COMPONENT "smc"
20 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
21 
22 #include <linux/module.h>
23 #include <linux/socket.h>
24 #include <linux/workqueue.h>
25 #include <linux/in.h>
26 #include <linux/sched/signal.h>
27 #include <linux/if_vlan.h>
28 #include <linux/rcupdate_wait.h>
29 #include <linux/ctype.h>
30 
31 #include <net/sock.h>
32 #include <net/tcp.h>
33 #include <net/smc.h>
34 #include <asm/ioctls.h>
35 
36 #include <net/net_namespace.h>
37 #include <net/netns/generic.h>
38 #include "smc_netns.h"
39 
40 #include "smc.h"
41 #include "smc_clc.h"
42 #include "smc_llc.h"
43 #include "smc_cdc.h"
44 #include "smc_core.h"
45 #include "smc_ib.h"
46 #include "smc_ism.h"
47 #include "smc_pnet.h"
48 #include "smc_netlink.h"
49 #include "smc_tx.h"
50 #include "smc_rx.h"
51 #include "smc_close.h"
52 #include "smc_stats.h"
53 #include "smc_tracepoint.h"
54 
55 static DEFINE_MUTEX(smc_server_lgr_pending);	/* serialize link group
56 						 * creation on server
57 						 */
58 static DEFINE_MUTEX(smc_client_lgr_pending);	/* serialize link group
59 						 * creation on client
60 						 */
61 
62 struct workqueue_struct	*smc_hs_wq;	/* wq for handshake work */
63 struct workqueue_struct	*smc_close_wq;	/* wq for close work */
64 
65 static void smc_tcp_listen_work(struct work_struct *);
66 static void smc_connect_work(struct work_struct *);
67 
68 static void smc_set_keepalive(struct sock *sk, int val)
69 {
70 	struct smc_sock *smc = smc_sk(sk);
71 
72 	smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
73 }
74 
75 static struct smc_hashinfo smc_v4_hashinfo = {
76 	.lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
77 };
78 
79 static struct smc_hashinfo smc_v6_hashinfo = {
80 	.lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
81 };
82 
83 int smc_hash_sk(struct sock *sk)
84 {
85 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
86 	struct hlist_head *head;
87 
88 	head = &h->ht;
89 
90 	write_lock_bh(&h->lock);
91 	sk_add_node(sk, head);
92 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
93 	write_unlock_bh(&h->lock);
94 
95 	return 0;
96 }
97 EXPORT_SYMBOL_GPL(smc_hash_sk);
98 
99 void smc_unhash_sk(struct sock *sk)
100 {
101 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
102 
103 	write_lock_bh(&h->lock);
104 	if (sk_del_node_init(sk))
105 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
106 	write_unlock_bh(&h->lock);
107 }
108 EXPORT_SYMBOL_GPL(smc_unhash_sk);
109 
110 struct proto smc_proto = {
111 	.name		= "SMC",
112 	.owner		= THIS_MODULE,
113 	.keepalive	= smc_set_keepalive,
114 	.hash		= smc_hash_sk,
115 	.unhash		= smc_unhash_sk,
116 	.obj_size	= sizeof(struct smc_sock),
117 	.h.smc_hash	= &smc_v4_hashinfo,
118 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
119 };
120 EXPORT_SYMBOL_GPL(smc_proto);
121 
122 struct proto smc_proto6 = {
123 	.name		= "SMC6",
124 	.owner		= THIS_MODULE,
125 	.keepalive	= smc_set_keepalive,
126 	.hash		= smc_hash_sk,
127 	.unhash		= smc_unhash_sk,
128 	.obj_size	= sizeof(struct smc_sock),
129 	.h.smc_hash	= &smc_v6_hashinfo,
130 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
131 };
132 EXPORT_SYMBOL_GPL(smc_proto6);
133 
134 static void smc_restore_fallback_changes(struct smc_sock *smc)
135 {
136 	if (smc->clcsock->file) { /* non-accepted sockets have no file yet */
137 		smc->clcsock->file->private_data = smc->sk.sk_socket;
138 		smc->clcsock->file = NULL;
139 	}
140 }
141 
142 static int __smc_release(struct smc_sock *smc)
143 {
144 	struct sock *sk = &smc->sk;
145 	int rc = 0;
146 
147 	if (!smc->use_fallback) {
148 		rc = smc_close_active(smc);
149 		sock_set_flag(sk, SOCK_DEAD);
150 		sk->sk_shutdown |= SHUTDOWN_MASK;
151 	} else {
152 		if (sk->sk_state != SMC_CLOSED) {
153 			if (sk->sk_state != SMC_LISTEN &&
154 			    sk->sk_state != SMC_INIT)
155 				sock_put(sk); /* passive closing */
156 			if (sk->sk_state == SMC_LISTEN) {
157 				/* wake up clcsock accept */
158 				rc = kernel_sock_shutdown(smc->clcsock,
159 							  SHUT_RDWR);
160 			}
161 			sk->sk_state = SMC_CLOSED;
162 			sk->sk_state_change(sk);
163 		}
164 		smc_restore_fallback_changes(smc);
165 	}
166 
167 	sk->sk_prot->unhash(sk);
168 
169 	if (sk->sk_state == SMC_CLOSED) {
170 		if (smc->clcsock) {
171 			release_sock(sk);
172 			smc_clcsock_release(smc);
173 			lock_sock(sk);
174 		}
175 		if (!smc->use_fallback)
176 			smc_conn_free(&smc->conn);
177 	}
178 
179 	return rc;
180 }
181 
182 static int smc_release(struct socket *sock)
183 {
184 	struct sock *sk = sock->sk;
185 	struct smc_sock *smc;
186 	int rc = 0;
187 
188 	if (!sk)
189 		goto out;
190 
191 	sock_hold(sk); /* sock_put below */
192 	smc = smc_sk(sk);
193 
194 	/* cleanup for a dangling non-blocking connect */
195 	if (smc->connect_nonblock && sk->sk_state == SMC_INIT)
196 		tcp_abort(smc->clcsock->sk, ECONNABORTED);
197 	flush_work(&smc->connect_work);
198 
199 	if (sk->sk_state == SMC_LISTEN)
200 		/* smc_close_non_accepted() is called and acquires
201 		 * sock lock for child sockets again
202 		 */
203 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
204 	else
205 		lock_sock(sk);
206 
207 	rc = __smc_release(smc);
208 
209 	/* detach socket */
210 	sock_orphan(sk);
211 	sock->sk = NULL;
212 	release_sock(sk);
213 
214 	sock_put(sk); /* sock_hold above */
215 	sock_put(sk); /* final sock_put */
216 out:
217 	return rc;
218 }
219 
220 static void smc_destruct(struct sock *sk)
221 {
222 	if (sk->sk_state != SMC_CLOSED)
223 		return;
224 	if (!sock_flag(sk, SOCK_DEAD))
225 		return;
226 
227 	sk_refcnt_debug_dec(sk);
228 }
229 
230 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
231 				   int protocol)
232 {
233 	struct smc_sock *smc;
234 	struct proto *prot;
235 	struct sock *sk;
236 
237 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
238 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
239 	if (!sk)
240 		return NULL;
241 
242 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
243 	sk->sk_state = SMC_INIT;
244 	sk->sk_destruct = smc_destruct;
245 	sk->sk_protocol = protocol;
246 	smc = smc_sk(sk);
247 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
248 	INIT_WORK(&smc->connect_work, smc_connect_work);
249 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
250 	INIT_LIST_HEAD(&smc->accept_q);
251 	spin_lock_init(&smc->accept_q_lock);
252 	spin_lock_init(&smc->conn.send_lock);
253 	sk->sk_prot->hash(sk);
254 	sk_refcnt_debug_inc(sk);
255 	mutex_init(&smc->clcsock_release_lock);
256 
257 	return sk;
258 }
259 
260 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
261 		    int addr_len)
262 {
263 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
264 	struct sock *sk = sock->sk;
265 	struct smc_sock *smc;
266 	int rc;
267 
268 	smc = smc_sk(sk);
269 
270 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
271 	rc = -EINVAL;
272 	if (addr_len < sizeof(struct sockaddr_in))
273 		goto out;
274 
275 	rc = -EAFNOSUPPORT;
276 	if (addr->sin_family != AF_INET &&
277 	    addr->sin_family != AF_INET6 &&
278 	    addr->sin_family != AF_UNSPEC)
279 		goto out;
280 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
281 	if (addr->sin_family == AF_UNSPEC &&
282 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
283 		goto out;
284 
285 	lock_sock(sk);
286 
287 	/* Check if socket is already active */
288 	rc = -EINVAL;
289 	if (sk->sk_state != SMC_INIT || smc->connect_nonblock)
290 		goto out_rel;
291 
292 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
293 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
294 
295 out_rel:
296 	release_sock(sk);
297 out:
298 	return rc;
299 }
300 
301 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
302 				   unsigned long mask)
303 {
304 	/* options we don't get control via setsockopt for */
305 	nsk->sk_type = osk->sk_type;
306 	nsk->sk_sndbuf = osk->sk_sndbuf;
307 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
308 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
309 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
310 	nsk->sk_mark = osk->sk_mark;
311 	nsk->sk_priority = osk->sk_priority;
312 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
313 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
314 	nsk->sk_err = osk->sk_err;
315 
316 	nsk->sk_flags &= ~mask;
317 	nsk->sk_flags |= osk->sk_flags & mask;
318 }
319 
320 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
321 			     (1UL << SOCK_KEEPOPEN) | \
322 			     (1UL << SOCK_LINGER) | \
323 			     (1UL << SOCK_BROADCAST) | \
324 			     (1UL << SOCK_TIMESTAMP) | \
325 			     (1UL << SOCK_DBG) | \
326 			     (1UL << SOCK_RCVTSTAMP) | \
327 			     (1UL << SOCK_RCVTSTAMPNS) | \
328 			     (1UL << SOCK_LOCALROUTE) | \
329 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
330 			     (1UL << SOCK_RXQ_OVFL) | \
331 			     (1UL << SOCK_WIFI_STATUS) | \
332 			     (1UL << SOCK_NOFCS) | \
333 			     (1UL << SOCK_FILTER_LOCKED) | \
334 			     (1UL << SOCK_TSTAMP_NEW))
335 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
336  * clc socket (since smc is not called for these options from net/core)
337  */
338 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
339 {
340 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
341 }
342 
343 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
344 			     (1UL << SOCK_KEEPOPEN) | \
345 			     (1UL << SOCK_LINGER) | \
346 			     (1UL << SOCK_DBG))
347 /* copy only settings and flags relevant for smc from clc to smc socket */
348 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
349 {
350 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
351 }
352 
353 /* register the new rmb on all links */
354 static int smcr_lgr_reg_rmbs(struct smc_link *link,
355 			     struct smc_buf_desc *rmb_desc)
356 {
357 	struct smc_link_group *lgr = link->lgr;
358 	int i, rc = 0;
359 
360 	rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
361 	if (rc)
362 		return rc;
363 	/* protect against parallel smc_llc_cli_rkey_exchange() and
364 	 * parallel smcr_link_reg_rmb()
365 	 */
366 	mutex_lock(&lgr->llc_conf_mutex);
367 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
368 		if (!smc_link_active(&lgr->lnk[i]))
369 			continue;
370 		rc = smcr_link_reg_rmb(&lgr->lnk[i], rmb_desc);
371 		if (rc)
372 			goto out;
373 	}
374 
375 	/* exchange confirm_rkey msg with peer */
376 	rc = smc_llc_do_confirm_rkey(link, rmb_desc);
377 	if (rc) {
378 		rc = -EFAULT;
379 		goto out;
380 	}
381 	rmb_desc->is_conf_rkey = true;
382 out:
383 	mutex_unlock(&lgr->llc_conf_mutex);
384 	smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
385 	return rc;
386 }
387 
388 static int smcr_clnt_conf_first_link(struct smc_sock *smc)
389 {
390 	struct smc_link *link = smc->conn.lnk;
391 	struct smc_llc_qentry *qentry;
392 	int rc;
393 
394 	/* receive CONFIRM LINK request from server over RoCE fabric */
395 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
396 			      SMC_LLC_CONFIRM_LINK);
397 	if (!qentry) {
398 		struct smc_clc_msg_decline dclc;
399 
400 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
401 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
402 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
403 	}
404 	smc_llc_save_peer_uid(qentry);
405 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_REQ);
406 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
407 	if (rc)
408 		return SMC_CLC_DECL_RMBE_EC;
409 
410 	rc = smc_ib_modify_qp_rts(link);
411 	if (rc)
412 		return SMC_CLC_DECL_ERR_RDYLNK;
413 
414 	smc_wr_remember_qp_attr(link);
415 
416 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc))
417 		return SMC_CLC_DECL_ERR_REGRMB;
418 
419 	/* confirm_rkey is implicit on 1st contact */
420 	smc->conn.rmb_desc->is_conf_rkey = true;
421 
422 	/* send CONFIRM LINK response over RoCE fabric */
423 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
424 	if (rc < 0)
425 		return SMC_CLC_DECL_TIMEOUT_CL;
426 
427 	smc_llc_link_active(link);
428 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
429 
430 	/* optional 2nd link, receive ADD LINK request from server */
431 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
432 			      SMC_LLC_ADD_LINK);
433 	if (!qentry) {
434 		struct smc_clc_msg_decline dclc;
435 
436 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
437 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
438 		if (rc == -EAGAIN)
439 			rc = 0; /* no DECLINE received, go with one link */
440 		return rc;
441 	}
442 	smc_llc_flow_qentry_clr(&link->lgr->llc_flow_lcl);
443 	smc_llc_cli_add_link(link, qentry);
444 	return 0;
445 }
446 
447 static bool smc_isascii(char *hostname)
448 {
449 	int i;
450 
451 	for (i = 0; i < SMC_MAX_HOSTNAME_LEN; i++)
452 		if (!isascii(hostname[i]))
453 			return false;
454 	return true;
455 }
456 
457 static void smc_conn_save_peer_info_fce(struct smc_sock *smc,
458 					struct smc_clc_msg_accept_confirm *clc)
459 {
460 	struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
461 		(struct smc_clc_msg_accept_confirm_v2 *)clc;
462 	struct smc_clc_first_contact_ext *fce;
463 	int clc_v2_len;
464 
465 	if (clc->hdr.version == SMC_V1 ||
466 	    !(clc->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
467 		return;
468 
469 	if (smc->conn.lgr->is_smcd) {
470 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->d1.eid,
471 		       SMC_MAX_EID_LEN);
472 		clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
473 					 d1);
474 	} else {
475 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->r1.eid,
476 		       SMC_MAX_EID_LEN);
477 		clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
478 					 r1);
479 	}
480 	fce = (struct smc_clc_first_contact_ext *)(((u8 *)clc_v2) + clc_v2_len);
481 	smc->conn.lgr->peer_os = fce->os_type;
482 	smc->conn.lgr->peer_smc_release = fce->release;
483 	if (smc_isascii(fce->hostname))
484 		memcpy(smc->conn.lgr->peer_hostname, fce->hostname,
485 		       SMC_MAX_HOSTNAME_LEN);
486 }
487 
488 static void smcr_conn_save_peer_info(struct smc_sock *smc,
489 				     struct smc_clc_msg_accept_confirm *clc)
490 {
491 	int bufsize = smc_uncompress_bufsize(clc->r0.rmbe_size);
492 
493 	smc->conn.peer_rmbe_idx = clc->r0.rmbe_idx;
494 	smc->conn.local_tx_ctrl.token = ntohl(clc->r0.rmbe_alert_token);
495 	smc->conn.peer_rmbe_size = bufsize;
496 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
497 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
498 }
499 
500 static void smcd_conn_save_peer_info(struct smc_sock *smc,
501 				     struct smc_clc_msg_accept_confirm *clc)
502 {
503 	int bufsize = smc_uncompress_bufsize(clc->d0.dmbe_size);
504 
505 	smc->conn.peer_rmbe_idx = clc->d0.dmbe_idx;
506 	smc->conn.peer_token = clc->d0.token;
507 	/* msg header takes up space in the buffer */
508 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
509 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
510 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
511 }
512 
513 static void smc_conn_save_peer_info(struct smc_sock *smc,
514 				    struct smc_clc_msg_accept_confirm *clc)
515 {
516 	if (smc->conn.lgr->is_smcd)
517 		smcd_conn_save_peer_info(smc, clc);
518 	else
519 		smcr_conn_save_peer_info(smc, clc);
520 	smc_conn_save_peer_info_fce(smc, clc);
521 }
522 
523 static void smc_link_save_peer_info(struct smc_link *link,
524 				    struct smc_clc_msg_accept_confirm *clc,
525 				    struct smc_init_info *ini)
526 {
527 	link->peer_qpn = ntoh24(clc->r0.qpn);
528 	memcpy(link->peer_gid, ini->peer_gid, SMC_GID_SIZE);
529 	memcpy(link->peer_mac, ini->peer_mac, sizeof(link->peer_mac));
530 	link->peer_psn = ntoh24(clc->r0.psn);
531 	link->peer_mtu = clc->r0.qp_mtu;
532 }
533 
534 static void smc_stat_inc_fback_rsn_cnt(struct smc_sock *smc,
535 				       struct smc_stats_fback *fback_arr)
536 {
537 	int cnt;
538 
539 	for (cnt = 0; cnt < SMC_MAX_FBACK_RSN_CNT; cnt++) {
540 		if (fback_arr[cnt].fback_code == smc->fallback_rsn) {
541 			fback_arr[cnt].count++;
542 			break;
543 		}
544 		if (!fback_arr[cnt].fback_code) {
545 			fback_arr[cnt].fback_code = smc->fallback_rsn;
546 			fback_arr[cnt].count++;
547 			break;
548 		}
549 	}
550 }
551 
552 static void smc_stat_fallback(struct smc_sock *smc)
553 {
554 	struct net *net = sock_net(&smc->sk);
555 
556 	mutex_lock(&net->smc.mutex_fback_rsn);
557 	if (smc->listen_smc) {
558 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->srv);
559 		net->smc.fback_rsn->srv_fback_cnt++;
560 	} else {
561 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->clnt);
562 		net->smc.fback_rsn->clnt_fback_cnt++;
563 	}
564 	mutex_unlock(&net->smc.mutex_fback_rsn);
565 }
566 
567 static void smc_switch_to_fallback(struct smc_sock *smc, int reason_code)
568 {
569 	smc->use_fallback = true;
570 	smc->fallback_rsn = reason_code;
571 	smc_stat_fallback(smc);
572 	trace_smc_switch_to_fallback(smc, reason_code);
573 	if (smc->sk.sk_socket && smc->sk.sk_socket->file) {
574 		smc->clcsock->file = smc->sk.sk_socket->file;
575 		smc->clcsock->file->private_data = smc->clcsock;
576 		smc->clcsock->wq.fasync_list =
577 			smc->sk.sk_socket->wq.fasync_list;
578 	}
579 }
580 
581 /* fall back during connect */
582 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
583 {
584 	smc_switch_to_fallback(smc, reason_code);
585 	smc_copy_sock_settings_to_clc(smc);
586 	smc->connect_nonblock = 0;
587 	if (smc->sk.sk_state == SMC_INIT)
588 		smc->sk.sk_state = SMC_ACTIVE;
589 	return 0;
590 }
591 
592 /* decline and fall back during connect */
593 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code,
594 					u8 version)
595 {
596 	struct net *net = sock_net(&smc->sk);
597 	int rc;
598 
599 	if (reason_code < 0) { /* error, fallback is not possible */
600 		this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
601 		if (smc->sk.sk_state == SMC_INIT)
602 			sock_put(&smc->sk); /* passive closing */
603 		return reason_code;
604 	}
605 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
606 		rc = smc_clc_send_decline(smc, reason_code, version);
607 		if (rc < 0) {
608 			this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
609 			if (smc->sk.sk_state == SMC_INIT)
610 				sock_put(&smc->sk); /* passive closing */
611 			return rc;
612 		}
613 	}
614 	return smc_connect_fallback(smc, reason_code);
615 }
616 
617 static void smc_conn_abort(struct smc_sock *smc, int local_first)
618 {
619 	if (local_first)
620 		smc_lgr_cleanup_early(&smc->conn);
621 	else
622 		smc_conn_free(&smc->conn);
623 }
624 
625 /* check if there is a rdma device available for this connection. */
626 /* called for connect and listen */
627 static int smc_find_rdma_device(struct smc_sock *smc, struct smc_init_info *ini)
628 {
629 	/* PNET table look up: search active ib_device and port
630 	 * within same PNETID that also contains the ethernet device
631 	 * used for the internal TCP socket
632 	 */
633 	smc_pnet_find_roce_resource(smc->clcsock->sk, ini);
634 	if (!ini->check_smcrv2 && !ini->ib_dev)
635 		return SMC_CLC_DECL_NOSMCRDEV;
636 	if (ini->check_smcrv2 && !ini->smcrv2.ib_dev_v2)
637 		return SMC_CLC_DECL_NOSMCRDEV;
638 	return 0;
639 }
640 
641 /* check if there is an ISM device available for this connection. */
642 /* called for connect and listen */
643 static int smc_find_ism_device(struct smc_sock *smc, struct smc_init_info *ini)
644 {
645 	/* Find ISM device with same PNETID as connecting interface  */
646 	smc_pnet_find_ism_resource(smc->clcsock->sk, ini);
647 	if (!ini->ism_dev[0])
648 		return SMC_CLC_DECL_NOSMCDDEV;
649 	else
650 		ini->ism_chid[0] = smc_ism_get_chid(ini->ism_dev[0]);
651 	return 0;
652 }
653 
654 /* is chid unique for the ism devices that are already determined? */
655 static bool smc_find_ism_v2_is_unique_chid(u16 chid, struct smc_init_info *ini,
656 					   int cnt)
657 {
658 	int i = (!ini->ism_dev[0]) ? 1 : 0;
659 
660 	for (; i < cnt; i++)
661 		if (ini->ism_chid[i] == chid)
662 			return false;
663 	return true;
664 }
665 
666 /* determine possible V2 ISM devices (either without PNETID or with PNETID plus
667  * PNETID matching net_device)
668  */
669 static int smc_find_ism_v2_device_clnt(struct smc_sock *smc,
670 				       struct smc_init_info *ini)
671 {
672 	int rc = SMC_CLC_DECL_NOSMCDDEV;
673 	struct smcd_dev *smcd;
674 	int i = 1;
675 	u16 chid;
676 
677 	if (smcd_indicated(ini->smc_type_v1))
678 		rc = 0;		/* already initialized for V1 */
679 	mutex_lock(&smcd_dev_list.mutex);
680 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
681 		if (smcd->going_away || smcd == ini->ism_dev[0])
682 			continue;
683 		chid = smc_ism_get_chid(smcd);
684 		if (!smc_find_ism_v2_is_unique_chid(chid, ini, i))
685 			continue;
686 		if (!smc_pnet_is_pnetid_set(smcd->pnetid) ||
687 		    smc_pnet_is_ndev_pnetid(sock_net(&smc->sk), smcd->pnetid)) {
688 			ini->ism_dev[i] = smcd;
689 			ini->ism_chid[i] = chid;
690 			ini->is_smcd = true;
691 			rc = 0;
692 			i++;
693 			if (i > SMC_MAX_ISM_DEVS)
694 				break;
695 		}
696 	}
697 	mutex_unlock(&smcd_dev_list.mutex);
698 	ini->ism_offered_cnt = i - 1;
699 	if (!ini->ism_dev[0] && !ini->ism_dev[1])
700 		ini->smcd_version = 0;
701 
702 	return rc;
703 }
704 
705 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
706 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
707 				      struct smc_init_info *ini)
708 {
709 	if (ini->vlan_id && smc_ism_get_vlan(ini->ism_dev[0], ini->vlan_id))
710 		return SMC_CLC_DECL_ISMVLANERR;
711 	return 0;
712 }
713 
714 static int smc_find_proposal_devices(struct smc_sock *smc,
715 				     struct smc_init_info *ini)
716 {
717 	int rc = 0;
718 
719 	/* check if there is an ism device available */
720 	if (!(ini->smcd_version & SMC_V1) ||
721 	    smc_find_ism_device(smc, ini) ||
722 	    smc_connect_ism_vlan_setup(smc, ini))
723 		ini->smcd_version &= ~SMC_V1;
724 	/* else ISM V1 is supported for this connection */
725 
726 	/* check if there is an rdma device available */
727 	if (!(ini->smcr_version & SMC_V1) ||
728 	    smc_find_rdma_device(smc, ini))
729 		ini->smcr_version &= ~SMC_V1;
730 	/* else RDMA is supported for this connection */
731 
732 	ini->smc_type_v1 = smc_indicated_type(ini->smcd_version & SMC_V1,
733 					      ini->smcr_version & SMC_V1);
734 
735 	/* check if there is an ism v2 device available */
736 	if (!(ini->smcd_version & SMC_V2) ||
737 	    !smc_ism_is_v2_capable() ||
738 	    smc_find_ism_v2_device_clnt(smc, ini))
739 		ini->smcd_version &= ~SMC_V2;
740 
741 	/* check if there is an rdma v2 device available */
742 	ini->check_smcrv2 = true;
743 	ini->smcrv2.saddr = smc->clcsock->sk->sk_rcv_saddr;
744 	if (!(ini->smcr_version & SMC_V2) ||
745 	    smc->clcsock->sk->sk_family != AF_INET ||
746 	    !smc_clc_ueid_count() ||
747 	    smc_find_rdma_device(smc, ini))
748 		ini->smcr_version &= ~SMC_V2;
749 	ini->check_smcrv2 = false;
750 
751 	ini->smc_type_v2 = smc_indicated_type(ini->smcd_version & SMC_V2,
752 					      ini->smcr_version & SMC_V2);
753 
754 	/* if neither ISM nor RDMA are supported, fallback */
755 	if (ini->smc_type_v1 == SMC_TYPE_N && ini->smc_type_v2 == SMC_TYPE_N)
756 		rc = SMC_CLC_DECL_NOSMCDEV;
757 
758 	return rc;
759 }
760 
761 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
762  * used, the VLAN ID will be registered again during the connection setup.
763  */
764 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc,
765 					struct smc_init_info *ini)
766 {
767 	if (!smcd_indicated(ini->smc_type_v1))
768 		return 0;
769 	if (ini->vlan_id && smc_ism_put_vlan(ini->ism_dev[0], ini->vlan_id))
770 		return SMC_CLC_DECL_CNFERR;
771 	return 0;
772 }
773 
774 #define SMC_CLC_MAX_ACCEPT_LEN \
775 	(sizeof(struct smc_clc_msg_accept_confirm_v2) + \
776 	 sizeof(struct smc_clc_first_contact_ext) + \
777 	 sizeof(struct smc_clc_msg_trail))
778 
779 /* CLC handshake during connect */
780 static int smc_connect_clc(struct smc_sock *smc,
781 			   struct smc_clc_msg_accept_confirm_v2 *aclc2,
782 			   struct smc_init_info *ini)
783 {
784 	int rc = 0;
785 
786 	/* do inband token exchange */
787 	rc = smc_clc_send_proposal(smc, ini);
788 	if (rc)
789 		return rc;
790 	/* receive SMC Accept CLC message */
791 	return smc_clc_wait_msg(smc, aclc2, SMC_CLC_MAX_ACCEPT_LEN,
792 				SMC_CLC_ACCEPT, CLC_WAIT_TIME);
793 }
794 
795 void smc_fill_gid_list(struct smc_link_group *lgr,
796 		       struct smc_gidlist *gidlist,
797 		       struct smc_ib_device *known_dev, u8 *known_gid)
798 {
799 	struct smc_init_info *alt_ini = NULL;
800 
801 	memset(gidlist, 0, sizeof(*gidlist));
802 	memcpy(gidlist->list[gidlist->len++], known_gid, SMC_GID_SIZE);
803 
804 	alt_ini = kzalloc(sizeof(*alt_ini), GFP_KERNEL);
805 	if (!alt_ini)
806 		goto out;
807 
808 	alt_ini->vlan_id = lgr->vlan_id;
809 	alt_ini->check_smcrv2 = true;
810 	alt_ini->smcrv2.saddr = lgr->saddr;
811 	smc_pnet_find_alt_roce(lgr, alt_ini, known_dev);
812 
813 	if (!alt_ini->smcrv2.ib_dev_v2)
814 		goto out;
815 
816 	memcpy(gidlist->list[gidlist->len++], alt_ini->smcrv2.ib_gid_v2,
817 	       SMC_GID_SIZE);
818 
819 out:
820 	kfree(alt_ini);
821 }
822 
823 static int smc_connect_rdma_v2_prepare(struct smc_sock *smc,
824 				       struct smc_clc_msg_accept_confirm *aclc,
825 				       struct smc_init_info *ini)
826 {
827 	struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
828 		(struct smc_clc_msg_accept_confirm_v2 *)aclc;
829 	struct smc_clc_first_contact_ext *fce =
830 		(struct smc_clc_first_contact_ext *)
831 			(((u8 *)clc_v2) + sizeof(*clc_v2));
832 
833 	if (!ini->first_contact_peer || aclc->hdr.version == SMC_V1)
834 		return 0;
835 
836 	if (fce->v2_direct) {
837 		memcpy(ini->smcrv2.nexthop_mac, &aclc->r0.lcl.mac, ETH_ALEN);
838 		ini->smcrv2.uses_gateway = false;
839 	} else {
840 		if (smc_ib_find_route(smc->clcsock->sk->sk_rcv_saddr,
841 				      smc_ib_gid_to_ipv4(aclc->r0.lcl.gid),
842 				      ini->smcrv2.nexthop_mac,
843 				      &ini->smcrv2.uses_gateway))
844 			return SMC_CLC_DECL_NOROUTE;
845 		if (!ini->smcrv2.uses_gateway) {
846 			/* mismatch: peer claims indirect, but its direct */
847 			return SMC_CLC_DECL_NOINDIRECT;
848 		}
849 	}
850 	return 0;
851 }
852 
853 /* setup for RDMA connection of client */
854 static int smc_connect_rdma(struct smc_sock *smc,
855 			    struct smc_clc_msg_accept_confirm *aclc,
856 			    struct smc_init_info *ini)
857 {
858 	int i, reason_code = 0;
859 	struct smc_link *link;
860 	u8 *eid = NULL;
861 
862 	ini->is_smcd = false;
863 	ini->ib_clcqpn = ntoh24(aclc->r0.qpn);
864 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
865 	memcpy(ini->peer_systemid, aclc->r0.lcl.id_for_peer, SMC_SYSTEMID_LEN);
866 	memcpy(ini->peer_gid, aclc->r0.lcl.gid, SMC_GID_SIZE);
867 	memcpy(ini->peer_mac, aclc->r0.lcl.mac, ETH_ALEN);
868 
869 	reason_code = smc_connect_rdma_v2_prepare(smc, aclc, ini);
870 	if (reason_code)
871 		return reason_code;
872 
873 	mutex_lock(&smc_client_lgr_pending);
874 	reason_code = smc_conn_create(smc, ini);
875 	if (reason_code) {
876 		mutex_unlock(&smc_client_lgr_pending);
877 		return reason_code;
878 	}
879 
880 	smc_conn_save_peer_info(smc, aclc);
881 
882 	if (ini->first_contact_local) {
883 		link = smc->conn.lnk;
884 	} else {
885 		/* set link that was assigned by server */
886 		link = NULL;
887 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
888 			struct smc_link *l = &smc->conn.lgr->lnk[i];
889 
890 			if (l->peer_qpn == ntoh24(aclc->r0.qpn) &&
891 			    !memcmp(l->peer_gid, &aclc->r0.lcl.gid,
892 				    SMC_GID_SIZE) &&
893 			    (aclc->hdr.version > SMC_V1 ||
894 			     !memcmp(l->peer_mac, &aclc->r0.lcl.mac,
895 				     sizeof(l->peer_mac)))) {
896 				link = l;
897 				break;
898 			}
899 		}
900 		if (!link) {
901 			reason_code = SMC_CLC_DECL_NOSRVLINK;
902 			goto connect_abort;
903 		}
904 		smc_switch_link_and_count(&smc->conn, link);
905 	}
906 
907 	/* create send buffer and rmb */
908 	if (smc_buf_create(smc, false)) {
909 		reason_code = SMC_CLC_DECL_MEM;
910 		goto connect_abort;
911 	}
912 
913 	if (ini->first_contact_local)
914 		smc_link_save_peer_info(link, aclc, ini);
915 
916 	if (smc_rmb_rtoken_handling(&smc->conn, link, aclc)) {
917 		reason_code = SMC_CLC_DECL_ERR_RTOK;
918 		goto connect_abort;
919 	}
920 
921 	smc_close_init(smc);
922 	smc_rx_init(smc);
923 
924 	if (ini->first_contact_local) {
925 		if (smc_ib_ready_link(link)) {
926 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
927 			goto connect_abort;
928 		}
929 	} else {
930 		if (smcr_lgr_reg_rmbs(link, smc->conn.rmb_desc)) {
931 			reason_code = SMC_CLC_DECL_ERR_REGRMB;
932 			goto connect_abort;
933 		}
934 	}
935 	smc_rmb_sync_sg_for_device(&smc->conn);
936 
937 	if (aclc->hdr.version > SMC_V1) {
938 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
939 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
940 
941 		eid = clc_v2->r1.eid;
942 		if (ini->first_contact_local)
943 			smc_fill_gid_list(link->lgr, &ini->smcrv2.gidlist,
944 					  link->smcibdev, link->gid);
945 	}
946 
947 	reason_code = smc_clc_send_confirm(smc, ini->first_contact_local,
948 					   aclc->hdr.version, eid, ini);
949 	if (reason_code)
950 		goto connect_abort;
951 
952 	smc_tx_init(smc);
953 
954 	if (ini->first_contact_local) {
955 		/* QP confirmation over RoCE fabric */
956 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
957 		reason_code = smcr_clnt_conf_first_link(smc);
958 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
959 		if (reason_code)
960 			goto connect_abort;
961 	}
962 	mutex_unlock(&smc_client_lgr_pending);
963 
964 	smc_copy_sock_settings_to_clc(smc);
965 	smc->connect_nonblock = 0;
966 	if (smc->sk.sk_state == SMC_INIT)
967 		smc->sk.sk_state = SMC_ACTIVE;
968 
969 	return 0;
970 connect_abort:
971 	smc_conn_abort(smc, ini->first_contact_local);
972 	mutex_unlock(&smc_client_lgr_pending);
973 	smc->connect_nonblock = 0;
974 
975 	return reason_code;
976 }
977 
978 /* The server has chosen one of the proposed ISM devices for the communication.
979  * Determine from the CHID of the received CLC ACCEPT the ISM device chosen.
980  */
981 static int
982 smc_v2_determine_accepted_chid(struct smc_clc_msg_accept_confirm_v2 *aclc,
983 			       struct smc_init_info *ini)
984 {
985 	int i;
986 
987 	for (i = 0; i < ini->ism_offered_cnt + 1; i++) {
988 		if (ini->ism_chid[i] == ntohs(aclc->d1.chid)) {
989 			ini->ism_selected = i;
990 			return 0;
991 		}
992 	}
993 
994 	return -EPROTO;
995 }
996 
997 /* setup for ISM connection of client */
998 static int smc_connect_ism(struct smc_sock *smc,
999 			   struct smc_clc_msg_accept_confirm *aclc,
1000 			   struct smc_init_info *ini)
1001 {
1002 	u8 *eid = NULL;
1003 	int rc = 0;
1004 
1005 	ini->is_smcd = true;
1006 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
1007 
1008 	if (aclc->hdr.version == SMC_V2) {
1009 		struct smc_clc_msg_accept_confirm_v2 *aclc_v2 =
1010 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1011 
1012 		rc = smc_v2_determine_accepted_chid(aclc_v2, ini);
1013 		if (rc)
1014 			return rc;
1015 	}
1016 	ini->ism_peer_gid[ini->ism_selected] = aclc->d0.gid;
1017 
1018 	/* there is only one lgr role for SMC-D; use server lock */
1019 	mutex_lock(&smc_server_lgr_pending);
1020 	rc = smc_conn_create(smc, ini);
1021 	if (rc) {
1022 		mutex_unlock(&smc_server_lgr_pending);
1023 		return rc;
1024 	}
1025 
1026 	/* Create send and receive buffers */
1027 	rc = smc_buf_create(smc, true);
1028 	if (rc) {
1029 		rc = (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB : SMC_CLC_DECL_MEM;
1030 		goto connect_abort;
1031 	}
1032 
1033 	smc_conn_save_peer_info(smc, aclc);
1034 	smc_close_init(smc);
1035 	smc_rx_init(smc);
1036 	smc_tx_init(smc);
1037 
1038 	if (aclc->hdr.version > SMC_V1) {
1039 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
1040 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1041 
1042 		eid = clc_v2->d1.eid;
1043 	}
1044 
1045 	rc = smc_clc_send_confirm(smc, ini->first_contact_local,
1046 				  aclc->hdr.version, eid, NULL);
1047 	if (rc)
1048 		goto connect_abort;
1049 	mutex_unlock(&smc_server_lgr_pending);
1050 
1051 	smc_copy_sock_settings_to_clc(smc);
1052 	smc->connect_nonblock = 0;
1053 	if (smc->sk.sk_state == SMC_INIT)
1054 		smc->sk.sk_state = SMC_ACTIVE;
1055 
1056 	return 0;
1057 connect_abort:
1058 	smc_conn_abort(smc, ini->first_contact_local);
1059 	mutex_unlock(&smc_server_lgr_pending);
1060 	smc->connect_nonblock = 0;
1061 
1062 	return rc;
1063 }
1064 
1065 /* check if received accept type and version matches a proposed one */
1066 static int smc_connect_check_aclc(struct smc_init_info *ini,
1067 				  struct smc_clc_msg_accept_confirm *aclc)
1068 {
1069 	if (aclc->hdr.typev1 != SMC_TYPE_R &&
1070 	    aclc->hdr.typev1 != SMC_TYPE_D)
1071 		return SMC_CLC_DECL_MODEUNSUPP;
1072 
1073 	if (aclc->hdr.version >= SMC_V2) {
1074 		if ((aclc->hdr.typev1 == SMC_TYPE_R &&
1075 		     !smcr_indicated(ini->smc_type_v2)) ||
1076 		    (aclc->hdr.typev1 == SMC_TYPE_D &&
1077 		     !smcd_indicated(ini->smc_type_v2)))
1078 			return SMC_CLC_DECL_MODEUNSUPP;
1079 	} else {
1080 		if ((aclc->hdr.typev1 == SMC_TYPE_R &&
1081 		     !smcr_indicated(ini->smc_type_v1)) ||
1082 		    (aclc->hdr.typev1 == SMC_TYPE_D &&
1083 		     !smcd_indicated(ini->smc_type_v1)))
1084 			return SMC_CLC_DECL_MODEUNSUPP;
1085 	}
1086 
1087 	return 0;
1088 }
1089 
1090 /* perform steps before actually connecting */
1091 static int __smc_connect(struct smc_sock *smc)
1092 {
1093 	u8 version = smc_ism_is_v2_capable() ? SMC_V2 : SMC_V1;
1094 	struct smc_clc_msg_accept_confirm_v2 *aclc2;
1095 	struct smc_clc_msg_accept_confirm *aclc;
1096 	struct smc_init_info *ini = NULL;
1097 	u8 *buf = NULL;
1098 	int rc = 0;
1099 
1100 	if (smc->use_fallback)
1101 		return smc_connect_fallback(smc, smc->fallback_rsn);
1102 
1103 	/* if peer has not signalled SMC-capability, fall back */
1104 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
1105 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
1106 
1107 	/* IPSec connections opt out of SMC optimizations */
1108 	if (using_ipsec(smc))
1109 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC,
1110 						    version);
1111 
1112 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1113 	if (!ini)
1114 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_MEM,
1115 						    version);
1116 
1117 	ini->smcd_version = SMC_V1 | SMC_V2;
1118 	ini->smcr_version = SMC_V1 | SMC_V2;
1119 	ini->smc_type_v1 = SMC_TYPE_B;
1120 	ini->smc_type_v2 = SMC_TYPE_B;
1121 
1122 	/* get vlan id from IP device */
1123 	if (smc_vlan_by_tcpsk(smc->clcsock, ini)) {
1124 		ini->smcd_version &= ~SMC_V1;
1125 		ini->smcr_version = 0;
1126 		ini->smc_type_v1 = SMC_TYPE_N;
1127 		if (!ini->smcd_version) {
1128 			rc = SMC_CLC_DECL_GETVLANERR;
1129 			goto fallback;
1130 		}
1131 	}
1132 
1133 	rc = smc_find_proposal_devices(smc, ini);
1134 	if (rc)
1135 		goto fallback;
1136 
1137 	buf = kzalloc(SMC_CLC_MAX_ACCEPT_LEN, GFP_KERNEL);
1138 	if (!buf) {
1139 		rc = SMC_CLC_DECL_MEM;
1140 		goto fallback;
1141 	}
1142 	aclc2 = (struct smc_clc_msg_accept_confirm_v2 *)buf;
1143 	aclc = (struct smc_clc_msg_accept_confirm *)aclc2;
1144 
1145 	/* perform CLC handshake */
1146 	rc = smc_connect_clc(smc, aclc2, ini);
1147 	if (rc)
1148 		goto vlan_cleanup;
1149 
1150 	/* check if smc modes and versions of CLC proposal and accept match */
1151 	rc = smc_connect_check_aclc(ini, aclc);
1152 	version = aclc->hdr.version == SMC_V1 ? SMC_V1 : SMC_V2;
1153 	if (rc)
1154 		goto vlan_cleanup;
1155 
1156 	/* depending on previous steps, connect using rdma or ism */
1157 	if (aclc->hdr.typev1 == SMC_TYPE_R) {
1158 		ini->smcr_version = version;
1159 		rc = smc_connect_rdma(smc, aclc, ini);
1160 	} else if (aclc->hdr.typev1 == SMC_TYPE_D) {
1161 		ini->smcd_version = version;
1162 		rc = smc_connect_ism(smc, aclc, ini);
1163 	}
1164 	if (rc)
1165 		goto vlan_cleanup;
1166 
1167 	SMC_STAT_CLNT_SUCC_INC(sock_net(smc->clcsock->sk), aclc);
1168 	smc_connect_ism_vlan_cleanup(smc, ini);
1169 	kfree(buf);
1170 	kfree(ini);
1171 	return 0;
1172 
1173 vlan_cleanup:
1174 	smc_connect_ism_vlan_cleanup(smc, ini);
1175 	kfree(buf);
1176 fallback:
1177 	kfree(ini);
1178 	return smc_connect_decline_fallback(smc, rc, version);
1179 }
1180 
1181 static void smc_connect_work(struct work_struct *work)
1182 {
1183 	struct smc_sock *smc = container_of(work, struct smc_sock,
1184 					    connect_work);
1185 	long timeo = smc->sk.sk_sndtimeo;
1186 	int rc = 0;
1187 
1188 	if (!timeo)
1189 		timeo = MAX_SCHEDULE_TIMEOUT;
1190 	lock_sock(smc->clcsock->sk);
1191 	if (smc->clcsock->sk->sk_err) {
1192 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
1193 	} else if ((1 << smc->clcsock->sk->sk_state) &
1194 					(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
1195 		rc = sk_stream_wait_connect(smc->clcsock->sk, &timeo);
1196 		if ((rc == -EPIPE) &&
1197 		    ((1 << smc->clcsock->sk->sk_state) &
1198 					(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))
1199 			rc = 0;
1200 	}
1201 	release_sock(smc->clcsock->sk);
1202 	lock_sock(&smc->sk);
1203 	if (rc != 0 || smc->sk.sk_err) {
1204 		smc->sk.sk_state = SMC_CLOSED;
1205 		if (rc == -EPIPE || rc == -EAGAIN)
1206 			smc->sk.sk_err = EPIPE;
1207 		else if (signal_pending(current))
1208 			smc->sk.sk_err = -sock_intr_errno(timeo);
1209 		sock_put(&smc->sk); /* passive closing */
1210 		goto out;
1211 	}
1212 
1213 	rc = __smc_connect(smc);
1214 	if (rc < 0)
1215 		smc->sk.sk_err = -rc;
1216 
1217 out:
1218 	if (!sock_flag(&smc->sk, SOCK_DEAD)) {
1219 		if (smc->sk.sk_err) {
1220 			smc->sk.sk_state_change(&smc->sk);
1221 		} else { /* allow polling before and after fallback decision */
1222 			smc->clcsock->sk->sk_write_space(smc->clcsock->sk);
1223 			smc->sk.sk_write_space(&smc->sk);
1224 		}
1225 	}
1226 	release_sock(&smc->sk);
1227 }
1228 
1229 static int smc_connect(struct socket *sock, struct sockaddr *addr,
1230 		       int alen, int flags)
1231 {
1232 	struct sock *sk = sock->sk;
1233 	struct smc_sock *smc;
1234 	int rc = -EINVAL;
1235 
1236 	smc = smc_sk(sk);
1237 
1238 	/* separate smc parameter checking to be safe */
1239 	if (alen < sizeof(addr->sa_family))
1240 		goto out_err;
1241 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
1242 		goto out_err;
1243 
1244 	lock_sock(sk);
1245 	switch (sk->sk_state) {
1246 	default:
1247 		goto out;
1248 	case SMC_ACTIVE:
1249 		rc = -EISCONN;
1250 		goto out;
1251 	case SMC_INIT:
1252 		break;
1253 	}
1254 
1255 	smc_copy_sock_settings_to_clc(smc);
1256 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1257 	if (smc->connect_nonblock) {
1258 		rc = -EALREADY;
1259 		goto out;
1260 	}
1261 	rc = kernel_connect(smc->clcsock, addr, alen, flags);
1262 	if (rc && rc != -EINPROGRESS)
1263 		goto out;
1264 
1265 	sock_hold(&smc->sk); /* sock put in passive closing */
1266 	if (smc->use_fallback)
1267 		goto out;
1268 	if (flags & O_NONBLOCK) {
1269 		if (queue_work(smc_hs_wq, &smc->connect_work))
1270 			smc->connect_nonblock = 1;
1271 		rc = -EINPROGRESS;
1272 	} else {
1273 		rc = __smc_connect(smc);
1274 		if (rc < 0)
1275 			goto out;
1276 		else
1277 			rc = 0; /* success cases including fallback */
1278 	}
1279 
1280 out:
1281 	release_sock(sk);
1282 out_err:
1283 	return rc;
1284 }
1285 
1286 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
1287 {
1288 	struct socket *new_clcsock = NULL;
1289 	struct sock *lsk = &lsmc->sk;
1290 	struct sock *new_sk;
1291 	int rc = -EINVAL;
1292 
1293 	release_sock(lsk);
1294 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
1295 	if (!new_sk) {
1296 		rc = -ENOMEM;
1297 		lsk->sk_err = ENOMEM;
1298 		*new_smc = NULL;
1299 		lock_sock(lsk);
1300 		goto out;
1301 	}
1302 	*new_smc = smc_sk(new_sk);
1303 
1304 	mutex_lock(&lsmc->clcsock_release_lock);
1305 	if (lsmc->clcsock)
1306 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, SOCK_NONBLOCK);
1307 	mutex_unlock(&lsmc->clcsock_release_lock);
1308 	lock_sock(lsk);
1309 	if  (rc < 0 && rc != -EAGAIN)
1310 		lsk->sk_err = -rc;
1311 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
1312 		new_sk->sk_prot->unhash(new_sk);
1313 		if (new_clcsock)
1314 			sock_release(new_clcsock);
1315 		new_sk->sk_state = SMC_CLOSED;
1316 		sock_set_flag(new_sk, SOCK_DEAD);
1317 		sock_put(new_sk); /* final */
1318 		*new_smc = NULL;
1319 		goto out;
1320 	}
1321 
1322 	/* new clcsock has inherited the smc listen-specific sk_data_ready
1323 	 * function; switch it back to the original sk_data_ready function
1324 	 */
1325 	new_clcsock->sk->sk_data_ready = lsmc->clcsk_data_ready;
1326 	(*new_smc)->clcsock = new_clcsock;
1327 out:
1328 	return rc;
1329 }
1330 
1331 /* add a just created sock to the accept queue of the listen sock as
1332  * candidate for a following socket accept call from user space
1333  */
1334 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
1335 {
1336 	struct smc_sock *par = smc_sk(parent);
1337 
1338 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
1339 	spin_lock(&par->accept_q_lock);
1340 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
1341 	spin_unlock(&par->accept_q_lock);
1342 	sk_acceptq_added(parent);
1343 }
1344 
1345 /* remove a socket from the accept queue of its parental listening socket */
1346 static void smc_accept_unlink(struct sock *sk)
1347 {
1348 	struct smc_sock *par = smc_sk(sk)->listen_smc;
1349 
1350 	spin_lock(&par->accept_q_lock);
1351 	list_del_init(&smc_sk(sk)->accept_q);
1352 	spin_unlock(&par->accept_q_lock);
1353 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
1354 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
1355 }
1356 
1357 /* remove a sock from the accept queue to bind it to a new socket created
1358  * for a socket accept call from user space
1359  */
1360 struct sock *smc_accept_dequeue(struct sock *parent,
1361 				struct socket *new_sock)
1362 {
1363 	struct smc_sock *isk, *n;
1364 	struct sock *new_sk;
1365 
1366 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
1367 		new_sk = (struct sock *)isk;
1368 
1369 		smc_accept_unlink(new_sk);
1370 		if (new_sk->sk_state == SMC_CLOSED) {
1371 			new_sk->sk_prot->unhash(new_sk);
1372 			if (isk->clcsock) {
1373 				sock_release(isk->clcsock);
1374 				isk->clcsock = NULL;
1375 			}
1376 			sock_put(new_sk); /* final */
1377 			continue;
1378 		}
1379 		if (new_sock) {
1380 			sock_graft(new_sk, new_sock);
1381 			if (isk->use_fallback) {
1382 				smc_sk(new_sk)->clcsock->file = new_sock->file;
1383 				isk->clcsock->file->private_data = isk->clcsock;
1384 			}
1385 		}
1386 		return new_sk;
1387 	}
1388 	return NULL;
1389 }
1390 
1391 /* clean up for a created but never accepted sock */
1392 void smc_close_non_accepted(struct sock *sk)
1393 {
1394 	struct smc_sock *smc = smc_sk(sk);
1395 
1396 	sock_hold(sk); /* sock_put below */
1397 	lock_sock(sk);
1398 	if (!sk->sk_lingertime)
1399 		/* wait for peer closing */
1400 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
1401 	__smc_release(smc);
1402 	release_sock(sk);
1403 	sock_put(sk); /* sock_hold above */
1404 	sock_put(sk); /* final sock_put */
1405 }
1406 
1407 static int smcr_serv_conf_first_link(struct smc_sock *smc)
1408 {
1409 	struct smc_link *link = smc->conn.lnk;
1410 	struct smc_llc_qentry *qentry;
1411 	int rc;
1412 
1413 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc))
1414 		return SMC_CLC_DECL_ERR_REGRMB;
1415 
1416 	/* send CONFIRM LINK request to client over the RoCE fabric */
1417 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
1418 	if (rc < 0)
1419 		return SMC_CLC_DECL_TIMEOUT_CL;
1420 
1421 	/* receive CONFIRM LINK response from client over the RoCE fabric */
1422 	qentry = smc_llc_wait(link->lgr, link, SMC_LLC_WAIT_TIME,
1423 			      SMC_LLC_CONFIRM_LINK);
1424 	if (!qentry) {
1425 		struct smc_clc_msg_decline dclc;
1426 
1427 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1428 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1429 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
1430 	}
1431 	smc_llc_save_peer_uid(qentry);
1432 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_RESP);
1433 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
1434 	if (rc)
1435 		return SMC_CLC_DECL_RMBE_EC;
1436 
1437 	/* confirm_rkey is implicit on 1st contact */
1438 	smc->conn.rmb_desc->is_conf_rkey = true;
1439 
1440 	smc_llc_link_active(link);
1441 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
1442 
1443 	/* initial contact - try to establish second link */
1444 	smc_llc_srv_add_link(link, NULL);
1445 	return 0;
1446 }
1447 
1448 /* listen worker: finish */
1449 static void smc_listen_out(struct smc_sock *new_smc)
1450 {
1451 	struct smc_sock *lsmc = new_smc->listen_smc;
1452 	struct sock *newsmcsk = &new_smc->sk;
1453 
1454 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1455 		lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1456 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1457 		release_sock(&lsmc->sk);
1458 	} else { /* no longer listening */
1459 		smc_close_non_accepted(newsmcsk);
1460 	}
1461 
1462 	/* Wake up accept */
1463 	lsmc->sk.sk_data_ready(&lsmc->sk);
1464 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1465 }
1466 
1467 /* listen worker: finish in state connected */
1468 static void smc_listen_out_connected(struct smc_sock *new_smc)
1469 {
1470 	struct sock *newsmcsk = &new_smc->sk;
1471 
1472 	sk_refcnt_debug_inc(newsmcsk);
1473 	if (newsmcsk->sk_state == SMC_INIT)
1474 		newsmcsk->sk_state = SMC_ACTIVE;
1475 
1476 	smc_listen_out(new_smc);
1477 }
1478 
1479 /* listen worker: finish in error state */
1480 static void smc_listen_out_err(struct smc_sock *new_smc)
1481 {
1482 	struct sock *newsmcsk = &new_smc->sk;
1483 	struct net *net = sock_net(newsmcsk);
1484 
1485 	this_cpu_inc(net->smc.smc_stats->srv_hshake_err_cnt);
1486 	if (newsmcsk->sk_state == SMC_INIT)
1487 		sock_put(&new_smc->sk); /* passive closing */
1488 	newsmcsk->sk_state = SMC_CLOSED;
1489 
1490 	smc_listen_out(new_smc);
1491 }
1492 
1493 /* listen worker: decline and fall back if possible */
1494 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1495 			       int local_first, u8 version)
1496 {
1497 	/* RDMA setup failed, switch back to TCP */
1498 	smc_conn_abort(new_smc, local_first);
1499 	if (reason_code < 0) { /* error, no fallback possible */
1500 		smc_listen_out_err(new_smc);
1501 		return;
1502 	}
1503 	smc_switch_to_fallback(new_smc, reason_code);
1504 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1505 		if (smc_clc_send_decline(new_smc, reason_code, version) < 0) {
1506 			smc_listen_out_err(new_smc);
1507 			return;
1508 		}
1509 	}
1510 	smc_listen_out_connected(new_smc);
1511 }
1512 
1513 /* listen worker: version checking */
1514 static int smc_listen_v2_check(struct smc_sock *new_smc,
1515 			       struct smc_clc_msg_proposal *pclc,
1516 			       struct smc_init_info *ini)
1517 {
1518 	struct smc_clc_smcd_v2_extension *pclc_smcd_v2_ext;
1519 	struct smc_clc_v2_extension *pclc_v2_ext;
1520 	int rc = SMC_CLC_DECL_PEERNOSMC;
1521 
1522 	ini->smc_type_v1 = pclc->hdr.typev1;
1523 	ini->smc_type_v2 = pclc->hdr.typev2;
1524 	ini->smcd_version = smcd_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
1525 	ini->smcr_version = smcr_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
1526 	if (pclc->hdr.version > SMC_V1) {
1527 		if (smcd_indicated(ini->smc_type_v2))
1528 			ini->smcd_version |= SMC_V2;
1529 		if (smcr_indicated(ini->smc_type_v2))
1530 			ini->smcr_version |= SMC_V2;
1531 	}
1532 	if (!(ini->smcd_version & SMC_V2) && !(ini->smcr_version & SMC_V2)) {
1533 		rc = SMC_CLC_DECL_PEERNOSMC;
1534 		goto out;
1535 	}
1536 	pclc_v2_ext = smc_get_clc_v2_ext(pclc);
1537 	if (!pclc_v2_ext) {
1538 		ini->smcd_version &= ~SMC_V2;
1539 		ini->smcr_version &= ~SMC_V2;
1540 		rc = SMC_CLC_DECL_NOV2EXT;
1541 		goto out;
1542 	}
1543 	pclc_smcd_v2_ext = smc_get_clc_smcd_v2_ext(pclc_v2_ext);
1544 	if (ini->smcd_version & SMC_V2) {
1545 		if (!smc_ism_is_v2_capable()) {
1546 			ini->smcd_version &= ~SMC_V2;
1547 			rc = SMC_CLC_DECL_NOISM2SUPP;
1548 		} else if (!pclc_smcd_v2_ext) {
1549 			ini->smcd_version &= ~SMC_V2;
1550 			rc = SMC_CLC_DECL_NOV2DEXT;
1551 		} else if (!pclc_v2_ext->hdr.eid_cnt &&
1552 			   !pclc_v2_ext->hdr.flag.seid) {
1553 			ini->smcd_version &= ~SMC_V2;
1554 			rc = SMC_CLC_DECL_NOUEID;
1555 		}
1556 	}
1557 	if (ini->smcr_version & SMC_V2) {
1558 		if (!pclc_v2_ext->hdr.eid_cnt) {
1559 			ini->smcr_version &= ~SMC_V2;
1560 			rc = SMC_CLC_DECL_NOUEID;
1561 		}
1562 	}
1563 
1564 out:
1565 	if (!ini->smcd_version && !ini->smcr_version)
1566 		return rc;
1567 
1568 	return 0;
1569 }
1570 
1571 /* listen worker: check prefixes */
1572 static int smc_listen_prfx_check(struct smc_sock *new_smc,
1573 				 struct smc_clc_msg_proposal *pclc)
1574 {
1575 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1576 	struct socket *newclcsock = new_smc->clcsock;
1577 
1578 	if (pclc->hdr.typev1 == SMC_TYPE_N)
1579 		return 0;
1580 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1581 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1582 		return SMC_CLC_DECL_DIFFPREFIX;
1583 
1584 	return 0;
1585 }
1586 
1587 /* listen worker: initialize connection and buffers */
1588 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1589 				struct smc_init_info *ini)
1590 {
1591 	int rc;
1592 
1593 	/* allocate connection / link group */
1594 	rc = smc_conn_create(new_smc, ini);
1595 	if (rc)
1596 		return rc;
1597 
1598 	/* create send buffer and rmb */
1599 	if (smc_buf_create(new_smc, false))
1600 		return SMC_CLC_DECL_MEM;
1601 
1602 	return 0;
1603 }
1604 
1605 /* listen worker: initialize connection and buffers for SMC-D */
1606 static int smc_listen_ism_init(struct smc_sock *new_smc,
1607 			       struct smc_init_info *ini)
1608 {
1609 	int rc;
1610 
1611 	rc = smc_conn_create(new_smc, ini);
1612 	if (rc)
1613 		return rc;
1614 
1615 	/* Create send and receive buffers */
1616 	rc = smc_buf_create(new_smc, true);
1617 	if (rc) {
1618 		smc_conn_abort(new_smc, ini->first_contact_local);
1619 		return (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB :
1620 					 SMC_CLC_DECL_MEM;
1621 	}
1622 
1623 	return 0;
1624 }
1625 
1626 static bool smc_is_already_selected(struct smcd_dev *smcd,
1627 				    struct smc_init_info *ini,
1628 				    int matches)
1629 {
1630 	int i;
1631 
1632 	for (i = 0; i < matches; i++)
1633 		if (smcd == ini->ism_dev[i])
1634 			return true;
1635 
1636 	return false;
1637 }
1638 
1639 /* check for ISM devices matching proposed ISM devices */
1640 static void smc_check_ism_v2_match(struct smc_init_info *ini,
1641 				   u16 proposed_chid, u64 proposed_gid,
1642 				   unsigned int *matches)
1643 {
1644 	struct smcd_dev *smcd;
1645 
1646 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
1647 		if (smcd->going_away)
1648 			continue;
1649 		if (smc_is_already_selected(smcd, ini, *matches))
1650 			continue;
1651 		if (smc_ism_get_chid(smcd) == proposed_chid &&
1652 		    !smc_ism_cantalk(proposed_gid, ISM_RESERVED_VLANID, smcd)) {
1653 			ini->ism_peer_gid[*matches] = proposed_gid;
1654 			ini->ism_dev[*matches] = smcd;
1655 			(*matches)++;
1656 			break;
1657 		}
1658 	}
1659 }
1660 
1661 static void smc_find_ism_store_rc(u32 rc, struct smc_init_info *ini)
1662 {
1663 	if (!ini->rc)
1664 		ini->rc = rc;
1665 }
1666 
1667 static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
1668 					struct smc_clc_msg_proposal *pclc,
1669 					struct smc_init_info *ini)
1670 {
1671 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
1672 	struct smc_clc_v2_extension *smc_v2_ext;
1673 	struct smc_clc_msg_smcd *pclc_smcd;
1674 	unsigned int matches = 0;
1675 	u8 smcd_version;
1676 	u8 *eid = NULL;
1677 	int i, rc;
1678 
1679 	if (!(ini->smcd_version & SMC_V2) || !smcd_indicated(ini->smc_type_v2))
1680 		goto not_found;
1681 
1682 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
1683 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
1684 	smcd_v2_ext = smc_get_clc_smcd_v2_ext(smc_v2_ext);
1685 
1686 	mutex_lock(&smcd_dev_list.mutex);
1687 	if (pclc_smcd->ism.chid)
1688 		/* check for ISM device matching proposed native ISM device */
1689 		smc_check_ism_v2_match(ini, ntohs(pclc_smcd->ism.chid),
1690 				       ntohll(pclc_smcd->ism.gid), &matches);
1691 	for (i = 1; i <= smc_v2_ext->hdr.ism_gid_cnt; i++) {
1692 		/* check for ISM devices matching proposed non-native ISM
1693 		 * devices
1694 		 */
1695 		smc_check_ism_v2_match(ini,
1696 				       ntohs(smcd_v2_ext->gidchid[i - 1].chid),
1697 				       ntohll(smcd_v2_ext->gidchid[i - 1].gid),
1698 				       &matches);
1699 	}
1700 	mutex_unlock(&smcd_dev_list.mutex);
1701 
1702 	if (!ini->ism_dev[0]) {
1703 		smc_find_ism_store_rc(SMC_CLC_DECL_NOSMCD2DEV, ini);
1704 		goto not_found;
1705 	}
1706 
1707 	smc_ism_get_system_eid(&eid);
1708 	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext,
1709 			       smcd_v2_ext->system_eid, eid))
1710 		goto not_found;
1711 
1712 	/* separate - outside the smcd_dev_list.lock */
1713 	smcd_version = ini->smcd_version;
1714 	for (i = 0; i < matches; i++) {
1715 		ini->smcd_version = SMC_V2;
1716 		ini->is_smcd = true;
1717 		ini->ism_selected = i;
1718 		rc = smc_listen_ism_init(new_smc, ini);
1719 		if (rc) {
1720 			smc_find_ism_store_rc(rc, ini);
1721 			/* try next active ISM device */
1722 			continue;
1723 		}
1724 		return; /* matching and usable V2 ISM device found */
1725 	}
1726 	/* no V2 ISM device could be initialized */
1727 	ini->smcd_version = smcd_version;	/* restore original value */
1728 	ini->negotiated_eid[0] = 0;
1729 
1730 not_found:
1731 	ini->smcd_version &= ~SMC_V2;
1732 	ini->ism_dev[0] = NULL;
1733 	ini->is_smcd = false;
1734 }
1735 
1736 static void smc_find_ism_v1_device_serv(struct smc_sock *new_smc,
1737 					struct smc_clc_msg_proposal *pclc,
1738 					struct smc_init_info *ini)
1739 {
1740 	struct smc_clc_msg_smcd *pclc_smcd = smc_get_clc_msg_smcd(pclc);
1741 	int rc = 0;
1742 
1743 	/* check if ISM V1 is available */
1744 	if (!(ini->smcd_version & SMC_V1) || !smcd_indicated(ini->smc_type_v1))
1745 		goto not_found;
1746 	ini->is_smcd = true; /* prepare ISM check */
1747 	ini->ism_peer_gid[0] = ntohll(pclc_smcd->ism.gid);
1748 	rc = smc_find_ism_device(new_smc, ini);
1749 	if (rc)
1750 		goto not_found;
1751 	ini->ism_selected = 0;
1752 	rc = smc_listen_ism_init(new_smc, ini);
1753 	if (!rc)
1754 		return;		/* V1 ISM device found */
1755 
1756 not_found:
1757 	smc_find_ism_store_rc(rc, ini);
1758 	ini->smcd_version &= ~SMC_V1;
1759 	ini->ism_dev[0] = NULL;
1760 	ini->is_smcd = false;
1761 }
1762 
1763 /* listen worker: register buffers */
1764 static int smc_listen_rdma_reg(struct smc_sock *new_smc, bool local_first)
1765 {
1766 	struct smc_connection *conn = &new_smc->conn;
1767 
1768 	if (!local_first) {
1769 		if (smcr_lgr_reg_rmbs(conn->lnk, conn->rmb_desc))
1770 			return SMC_CLC_DECL_ERR_REGRMB;
1771 	}
1772 	smc_rmb_sync_sg_for_device(&new_smc->conn);
1773 
1774 	return 0;
1775 }
1776 
1777 static void smc_find_rdma_v2_device_serv(struct smc_sock *new_smc,
1778 					 struct smc_clc_msg_proposal *pclc,
1779 					 struct smc_init_info *ini)
1780 {
1781 	struct smc_clc_v2_extension *smc_v2_ext;
1782 	u8 smcr_version;
1783 	int rc;
1784 
1785 	if (!(ini->smcr_version & SMC_V2) || !smcr_indicated(ini->smc_type_v2))
1786 		goto not_found;
1787 
1788 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
1789 	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext, NULL, NULL))
1790 		goto not_found;
1791 
1792 	/* prepare RDMA check */
1793 	memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
1794 	memcpy(ini->peer_gid, smc_v2_ext->roce, SMC_GID_SIZE);
1795 	memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
1796 	ini->check_smcrv2 = true;
1797 	ini->smcrv2.clc_sk = new_smc->clcsock->sk;
1798 	ini->smcrv2.saddr = new_smc->clcsock->sk->sk_rcv_saddr;
1799 	ini->smcrv2.daddr = smc_ib_gid_to_ipv4(smc_v2_ext->roce);
1800 	rc = smc_find_rdma_device(new_smc, ini);
1801 	if (rc) {
1802 		smc_find_ism_store_rc(rc, ini);
1803 		goto not_found;
1804 	}
1805 	if (!ini->smcrv2.uses_gateway)
1806 		memcpy(ini->smcrv2.nexthop_mac, pclc->lcl.mac, ETH_ALEN);
1807 
1808 	smcr_version = ini->smcr_version;
1809 	ini->smcr_version = SMC_V2;
1810 	rc = smc_listen_rdma_init(new_smc, ini);
1811 	if (!rc)
1812 		rc = smc_listen_rdma_reg(new_smc, ini->first_contact_local);
1813 	if (!rc)
1814 		return;
1815 	ini->smcr_version = smcr_version;
1816 	smc_find_ism_store_rc(rc, ini);
1817 
1818 not_found:
1819 	ini->smcr_version &= ~SMC_V2;
1820 	ini->check_smcrv2 = false;
1821 }
1822 
1823 static int smc_find_rdma_v1_device_serv(struct smc_sock *new_smc,
1824 					struct smc_clc_msg_proposal *pclc,
1825 					struct smc_init_info *ini)
1826 {
1827 	int rc;
1828 
1829 	if (!(ini->smcr_version & SMC_V1) || !smcr_indicated(ini->smc_type_v1))
1830 		return SMC_CLC_DECL_NOSMCDEV;
1831 
1832 	/* prepare RDMA check */
1833 	memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
1834 	memcpy(ini->peer_gid, pclc->lcl.gid, SMC_GID_SIZE);
1835 	memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
1836 	rc = smc_find_rdma_device(new_smc, ini);
1837 	if (rc) {
1838 		/* no RDMA device found */
1839 		return SMC_CLC_DECL_NOSMCDEV;
1840 	}
1841 	rc = smc_listen_rdma_init(new_smc, ini);
1842 	if (rc)
1843 		return rc;
1844 	return smc_listen_rdma_reg(new_smc, ini->first_contact_local);
1845 }
1846 
1847 /* determine the local device matching to proposal */
1848 static int smc_listen_find_device(struct smc_sock *new_smc,
1849 				  struct smc_clc_msg_proposal *pclc,
1850 				  struct smc_init_info *ini)
1851 {
1852 	int prfx_rc;
1853 
1854 	/* check for ISM device matching V2 proposed device */
1855 	smc_find_ism_v2_device_serv(new_smc, pclc, ini);
1856 	if (ini->ism_dev[0])
1857 		return 0;
1858 
1859 	/* check for matching IP prefix and subnet length (V1) */
1860 	prfx_rc = smc_listen_prfx_check(new_smc, pclc);
1861 	if (prfx_rc)
1862 		smc_find_ism_store_rc(prfx_rc, ini);
1863 
1864 	/* get vlan id from IP device */
1865 	if (smc_vlan_by_tcpsk(new_smc->clcsock, ini))
1866 		return ini->rc ?: SMC_CLC_DECL_GETVLANERR;
1867 
1868 	/* check for ISM device matching V1 proposed device */
1869 	if (!prfx_rc)
1870 		smc_find_ism_v1_device_serv(new_smc, pclc, ini);
1871 	if (ini->ism_dev[0])
1872 		return 0;
1873 
1874 	if (!smcr_indicated(pclc->hdr.typev1) &&
1875 	    !smcr_indicated(pclc->hdr.typev2))
1876 		/* skip RDMA and decline */
1877 		return ini->rc ?: SMC_CLC_DECL_NOSMCDDEV;
1878 
1879 	/* check if RDMA V2 is available */
1880 	smc_find_rdma_v2_device_serv(new_smc, pclc, ini);
1881 	if (ini->smcrv2.ib_dev_v2)
1882 		return 0;
1883 
1884 	/* check if RDMA V1 is available */
1885 	if (!prfx_rc) {
1886 		int rc;
1887 
1888 		rc = smc_find_rdma_v1_device_serv(new_smc, pclc, ini);
1889 		smc_find_ism_store_rc(rc, ini);
1890 		return (!rc) ? 0 : ini->rc;
1891 	}
1892 	return SMC_CLC_DECL_NOSMCDEV;
1893 }
1894 
1895 /* listen worker: finish RDMA setup */
1896 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
1897 				  struct smc_clc_msg_accept_confirm *cclc,
1898 				  bool local_first,
1899 				  struct smc_init_info *ini)
1900 {
1901 	struct smc_link *link = new_smc->conn.lnk;
1902 	int reason_code = 0;
1903 
1904 	if (local_first)
1905 		smc_link_save_peer_info(link, cclc, ini);
1906 
1907 	if (smc_rmb_rtoken_handling(&new_smc->conn, link, cclc))
1908 		return SMC_CLC_DECL_ERR_RTOK;
1909 
1910 	if (local_first) {
1911 		if (smc_ib_ready_link(link))
1912 			return SMC_CLC_DECL_ERR_RDYLNK;
1913 		/* QP confirmation over RoCE fabric */
1914 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
1915 		reason_code = smcr_serv_conf_first_link(new_smc);
1916 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
1917 	}
1918 	return reason_code;
1919 }
1920 
1921 /* setup for connection of server */
1922 static void smc_listen_work(struct work_struct *work)
1923 {
1924 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
1925 						smc_listen_work);
1926 	struct socket *newclcsock = new_smc->clcsock;
1927 	struct smc_clc_msg_accept_confirm *cclc;
1928 	struct smc_clc_msg_proposal_area *buf;
1929 	struct smc_clc_msg_proposal *pclc;
1930 	struct smc_init_info *ini = NULL;
1931 	u8 proposal_version = SMC_V1;
1932 	u8 accept_version;
1933 	int rc = 0;
1934 
1935 	if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
1936 		return smc_listen_out_err(new_smc);
1937 
1938 	if (new_smc->use_fallback) {
1939 		smc_listen_out_connected(new_smc);
1940 		return;
1941 	}
1942 
1943 	/* check if peer is smc capable */
1944 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
1945 		smc_switch_to_fallback(new_smc, SMC_CLC_DECL_PEERNOSMC);
1946 		smc_listen_out_connected(new_smc);
1947 		return;
1948 	}
1949 
1950 	/* do inband token exchange -
1951 	 * wait for and receive SMC Proposal CLC message
1952 	 */
1953 	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
1954 	if (!buf) {
1955 		rc = SMC_CLC_DECL_MEM;
1956 		goto out_decl;
1957 	}
1958 	pclc = (struct smc_clc_msg_proposal *)buf;
1959 	rc = smc_clc_wait_msg(new_smc, pclc, sizeof(*buf),
1960 			      SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
1961 	if (rc)
1962 		goto out_decl;
1963 
1964 	if (pclc->hdr.version > SMC_V1)
1965 		proposal_version = SMC_V2;
1966 
1967 	/* IPSec connections opt out of SMC optimizations */
1968 	if (using_ipsec(new_smc)) {
1969 		rc = SMC_CLC_DECL_IPSEC;
1970 		goto out_decl;
1971 	}
1972 
1973 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1974 	if (!ini) {
1975 		rc = SMC_CLC_DECL_MEM;
1976 		goto out_decl;
1977 	}
1978 
1979 	/* initial version checking */
1980 	rc = smc_listen_v2_check(new_smc, pclc, ini);
1981 	if (rc)
1982 		goto out_decl;
1983 
1984 	mutex_lock(&smc_server_lgr_pending);
1985 	smc_close_init(new_smc);
1986 	smc_rx_init(new_smc);
1987 	smc_tx_init(new_smc);
1988 
1989 	/* determine ISM or RoCE device used for connection */
1990 	rc = smc_listen_find_device(new_smc, pclc, ini);
1991 	if (rc)
1992 		goto out_unlock;
1993 
1994 	/* send SMC Accept CLC message */
1995 	accept_version = ini->is_smcd ? ini->smcd_version : ini->smcr_version;
1996 	rc = smc_clc_send_accept(new_smc, ini->first_contact_local,
1997 				 accept_version, ini->negotiated_eid);
1998 	if (rc)
1999 		goto out_unlock;
2000 
2001 	/* SMC-D does not need this lock any more */
2002 	if (ini->is_smcd)
2003 		mutex_unlock(&smc_server_lgr_pending);
2004 
2005 	/* receive SMC Confirm CLC message */
2006 	memset(buf, 0, sizeof(*buf));
2007 	cclc = (struct smc_clc_msg_accept_confirm *)buf;
2008 	rc = smc_clc_wait_msg(new_smc, cclc, sizeof(*buf),
2009 			      SMC_CLC_CONFIRM, CLC_WAIT_TIME);
2010 	if (rc) {
2011 		if (!ini->is_smcd)
2012 			goto out_unlock;
2013 		goto out_decl;
2014 	}
2015 
2016 	/* finish worker */
2017 	if (!ini->is_smcd) {
2018 		rc = smc_listen_rdma_finish(new_smc, cclc,
2019 					    ini->first_contact_local, ini);
2020 		if (rc)
2021 			goto out_unlock;
2022 		mutex_unlock(&smc_server_lgr_pending);
2023 	}
2024 	smc_conn_save_peer_info(new_smc, cclc);
2025 	smc_listen_out_connected(new_smc);
2026 	SMC_STAT_SERV_SUCC_INC(sock_net(newclcsock->sk), ini);
2027 	goto out_free;
2028 
2029 out_unlock:
2030 	mutex_unlock(&smc_server_lgr_pending);
2031 out_decl:
2032 	smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0,
2033 			   proposal_version);
2034 out_free:
2035 	kfree(ini);
2036 	kfree(buf);
2037 }
2038 
2039 static void smc_tcp_listen_work(struct work_struct *work)
2040 {
2041 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
2042 					     tcp_listen_work);
2043 	struct sock *lsk = &lsmc->sk;
2044 	struct smc_sock *new_smc;
2045 	int rc = 0;
2046 
2047 	lock_sock(lsk);
2048 	while (lsk->sk_state == SMC_LISTEN) {
2049 		rc = smc_clcsock_accept(lsmc, &new_smc);
2050 		if (rc) /* clcsock accept queue empty or error */
2051 			goto out;
2052 		if (!new_smc)
2053 			continue;
2054 
2055 		new_smc->listen_smc = lsmc;
2056 		new_smc->use_fallback = lsmc->use_fallback;
2057 		new_smc->fallback_rsn = lsmc->fallback_rsn;
2058 		sock_hold(lsk); /* sock_put in smc_listen_work */
2059 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
2060 		smc_copy_sock_settings_to_smc(new_smc);
2061 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
2062 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
2063 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
2064 		if (!queue_work(smc_hs_wq, &new_smc->smc_listen_work))
2065 			sock_put(&new_smc->sk);
2066 	}
2067 
2068 out:
2069 	release_sock(lsk);
2070 	sock_put(&lsmc->sk); /* sock_hold in smc_clcsock_data_ready() */
2071 }
2072 
2073 static void smc_clcsock_data_ready(struct sock *listen_clcsock)
2074 {
2075 	struct smc_sock *lsmc;
2076 
2077 	lsmc = (struct smc_sock *)
2078 	       ((uintptr_t)listen_clcsock->sk_user_data & ~SK_USER_DATA_NOCOPY);
2079 	if (!lsmc)
2080 		return;
2081 	lsmc->clcsk_data_ready(listen_clcsock);
2082 	if (lsmc->sk.sk_state == SMC_LISTEN) {
2083 		sock_hold(&lsmc->sk); /* sock_put in smc_tcp_listen_work() */
2084 		if (!queue_work(smc_hs_wq, &lsmc->tcp_listen_work))
2085 			sock_put(&lsmc->sk);
2086 	}
2087 }
2088 
2089 static int smc_listen(struct socket *sock, int backlog)
2090 {
2091 	struct sock *sk = sock->sk;
2092 	struct smc_sock *smc;
2093 	int rc;
2094 
2095 	smc = smc_sk(sk);
2096 	lock_sock(sk);
2097 
2098 	rc = -EINVAL;
2099 	if ((sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) ||
2100 	    smc->connect_nonblock)
2101 		goto out;
2102 
2103 	rc = 0;
2104 	if (sk->sk_state == SMC_LISTEN) {
2105 		sk->sk_max_ack_backlog = backlog;
2106 		goto out;
2107 	}
2108 	/* some socket options are handled in core, so we could not apply
2109 	 * them to the clc socket -- copy smc socket options to clc socket
2110 	 */
2111 	smc_copy_sock_settings_to_clc(smc);
2112 	if (!smc->use_fallback)
2113 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
2114 
2115 	/* save original sk_data_ready function and establish
2116 	 * smc-specific sk_data_ready function
2117 	 */
2118 	smc->clcsk_data_ready = smc->clcsock->sk->sk_data_ready;
2119 	smc->clcsock->sk->sk_data_ready = smc_clcsock_data_ready;
2120 	smc->clcsock->sk->sk_user_data =
2121 		(void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
2122 	rc = kernel_listen(smc->clcsock, backlog);
2123 	if (rc)
2124 		goto out;
2125 	sk->sk_max_ack_backlog = backlog;
2126 	sk->sk_ack_backlog = 0;
2127 	sk->sk_state = SMC_LISTEN;
2128 
2129 out:
2130 	release_sock(sk);
2131 	return rc;
2132 }
2133 
2134 static int smc_accept(struct socket *sock, struct socket *new_sock,
2135 		      int flags, bool kern)
2136 {
2137 	struct sock *sk = sock->sk, *nsk;
2138 	DECLARE_WAITQUEUE(wait, current);
2139 	struct smc_sock *lsmc;
2140 	long timeo;
2141 	int rc = 0;
2142 
2143 	lsmc = smc_sk(sk);
2144 	sock_hold(sk); /* sock_put below */
2145 	lock_sock(sk);
2146 
2147 	if (lsmc->sk.sk_state != SMC_LISTEN) {
2148 		rc = -EINVAL;
2149 		release_sock(sk);
2150 		goto out;
2151 	}
2152 
2153 	/* Wait for an incoming connection */
2154 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
2155 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
2156 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
2157 		set_current_state(TASK_INTERRUPTIBLE);
2158 		if (!timeo) {
2159 			rc = -EAGAIN;
2160 			break;
2161 		}
2162 		release_sock(sk);
2163 		timeo = schedule_timeout(timeo);
2164 		/* wakeup by sk_data_ready in smc_listen_work() */
2165 		sched_annotate_sleep();
2166 		lock_sock(sk);
2167 		if (signal_pending(current)) {
2168 			rc = sock_intr_errno(timeo);
2169 			break;
2170 		}
2171 	}
2172 	set_current_state(TASK_RUNNING);
2173 	remove_wait_queue(sk_sleep(sk), &wait);
2174 
2175 	if (!rc)
2176 		rc = sock_error(nsk);
2177 	release_sock(sk);
2178 	if (rc)
2179 		goto out;
2180 
2181 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
2182 		/* wait till data arrives on the socket */
2183 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
2184 								MSEC_PER_SEC);
2185 		if (smc_sk(nsk)->use_fallback) {
2186 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
2187 
2188 			lock_sock(clcsk);
2189 			if (skb_queue_empty(&clcsk->sk_receive_queue))
2190 				sk_wait_data(clcsk, &timeo, NULL);
2191 			release_sock(clcsk);
2192 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
2193 			lock_sock(nsk);
2194 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
2195 			release_sock(nsk);
2196 		}
2197 	}
2198 
2199 out:
2200 	sock_put(sk); /* sock_hold above */
2201 	return rc;
2202 }
2203 
2204 static int smc_getname(struct socket *sock, struct sockaddr *addr,
2205 		       int peer)
2206 {
2207 	struct smc_sock *smc;
2208 
2209 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
2210 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
2211 		return -ENOTCONN;
2212 
2213 	smc = smc_sk(sock->sk);
2214 
2215 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
2216 }
2217 
2218 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2219 {
2220 	struct sock *sk = sock->sk;
2221 	struct smc_sock *smc;
2222 	int rc = -EPIPE;
2223 
2224 	smc = smc_sk(sk);
2225 	lock_sock(sk);
2226 	if ((sk->sk_state != SMC_ACTIVE) &&
2227 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2228 	    (sk->sk_state != SMC_INIT))
2229 		goto out;
2230 
2231 	if (msg->msg_flags & MSG_FASTOPEN) {
2232 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2233 			smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2234 		} else {
2235 			rc = -EINVAL;
2236 			goto out;
2237 		}
2238 	}
2239 
2240 	if (smc->use_fallback) {
2241 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
2242 	} else {
2243 		rc = smc_tx_sendmsg(smc, msg, len);
2244 		SMC_STAT_TX_PAYLOAD(smc, len, rc);
2245 	}
2246 out:
2247 	release_sock(sk);
2248 	return rc;
2249 }
2250 
2251 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2252 		       int flags)
2253 {
2254 	struct sock *sk = sock->sk;
2255 	struct smc_sock *smc;
2256 	int rc = -ENOTCONN;
2257 
2258 	smc = smc_sk(sk);
2259 	lock_sock(sk);
2260 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2261 		/* socket was connected before, no more data to read */
2262 		rc = 0;
2263 		goto out;
2264 	}
2265 	if ((sk->sk_state == SMC_INIT) ||
2266 	    (sk->sk_state == SMC_LISTEN) ||
2267 	    (sk->sk_state == SMC_CLOSED))
2268 		goto out;
2269 
2270 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2271 		rc = 0;
2272 		goto out;
2273 	}
2274 
2275 	if (smc->use_fallback) {
2276 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
2277 	} else {
2278 		msg->msg_namelen = 0;
2279 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
2280 		SMC_STAT_RX_PAYLOAD(smc, rc, rc);
2281 	}
2282 
2283 out:
2284 	release_sock(sk);
2285 	return rc;
2286 }
2287 
2288 static __poll_t smc_accept_poll(struct sock *parent)
2289 {
2290 	struct smc_sock *isk = smc_sk(parent);
2291 	__poll_t mask = 0;
2292 
2293 	spin_lock(&isk->accept_q_lock);
2294 	if (!list_empty(&isk->accept_q))
2295 		mask = EPOLLIN | EPOLLRDNORM;
2296 	spin_unlock(&isk->accept_q_lock);
2297 
2298 	return mask;
2299 }
2300 
2301 static __poll_t smc_poll(struct file *file, struct socket *sock,
2302 			     poll_table *wait)
2303 {
2304 	struct sock *sk = sock->sk;
2305 	struct smc_sock *smc;
2306 	__poll_t mask = 0;
2307 
2308 	if (!sk)
2309 		return EPOLLNVAL;
2310 
2311 	smc = smc_sk(sock->sk);
2312 	if (smc->use_fallback) {
2313 		/* delegate to CLC child sock */
2314 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
2315 		sk->sk_err = smc->clcsock->sk->sk_err;
2316 	} else {
2317 		if (sk->sk_state != SMC_CLOSED)
2318 			sock_poll_wait(file, sock, wait);
2319 		if (sk->sk_err)
2320 			mask |= EPOLLERR;
2321 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
2322 		    (sk->sk_state == SMC_CLOSED))
2323 			mask |= EPOLLHUP;
2324 		if (sk->sk_state == SMC_LISTEN) {
2325 			/* woken up by sk_data_ready in smc_listen_work() */
2326 			mask |= smc_accept_poll(sk);
2327 		} else if (smc->use_fallback) { /* as result of connect_work()*/
2328 			mask |= smc->clcsock->ops->poll(file, smc->clcsock,
2329 							   wait);
2330 			sk->sk_err = smc->clcsock->sk->sk_err;
2331 		} else {
2332 			if ((sk->sk_state != SMC_INIT &&
2333 			     atomic_read(&smc->conn.sndbuf_space)) ||
2334 			    sk->sk_shutdown & SEND_SHUTDOWN) {
2335 				mask |= EPOLLOUT | EPOLLWRNORM;
2336 			} else {
2337 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2338 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2339 			}
2340 			if (atomic_read(&smc->conn.bytes_to_rcv))
2341 				mask |= EPOLLIN | EPOLLRDNORM;
2342 			if (sk->sk_shutdown & RCV_SHUTDOWN)
2343 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
2344 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
2345 				mask |= EPOLLIN;
2346 			if (smc->conn.urg_state == SMC_URG_VALID)
2347 				mask |= EPOLLPRI;
2348 		}
2349 	}
2350 
2351 	return mask;
2352 }
2353 
2354 static int smc_shutdown(struct socket *sock, int how)
2355 {
2356 	struct sock *sk = sock->sk;
2357 	struct smc_sock *smc;
2358 	int rc = -EINVAL;
2359 	int rc1 = 0;
2360 
2361 	smc = smc_sk(sk);
2362 
2363 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
2364 		return rc;
2365 
2366 	lock_sock(sk);
2367 
2368 	rc = -ENOTCONN;
2369 	if ((sk->sk_state != SMC_ACTIVE) &&
2370 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
2371 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
2372 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2373 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
2374 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
2375 		goto out;
2376 	if (smc->use_fallback) {
2377 		rc = kernel_sock_shutdown(smc->clcsock, how);
2378 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
2379 		if (sk->sk_shutdown == SHUTDOWN_MASK)
2380 			sk->sk_state = SMC_CLOSED;
2381 		goto out;
2382 	}
2383 	switch (how) {
2384 	case SHUT_RDWR:		/* shutdown in both directions */
2385 		rc = smc_close_active(smc);
2386 		break;
2387 	case SHUT_WR:
2388 		rc = smc_close_shutdown_write(smc);
2389 		break;
2390 	case SHUT_RD:
2391 		rc = 0;
2392 		/* nothing more to do because peer is not involved */
2393 		break;
2394 	}
2395 	if (smc->clcsock)
2396 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
2397 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
2398 	sk->sk_shutdown |= how + 1;
2399 
2400 out:
2401 	release_sock(sk);
2402 	return rc ? rc : rc1;
2403 }
2404 
2405 static int smc_setsockopt(struct socket *sock, int level, int optname,
2406 			  sockptr_t optval, unsigned int optlen)
2407 {
2408 	struct sock *sk = sock->sk;
2409 	struct smc_sock *smc;
2410 	int val, rc;
2411 
2412 	if (level == SOL_TCP && optname == TCP_ULP)
2413 		return -EOPNOTSUPP;
2414 
2415 	smc = smc_sk(sk);
2416 
2417 	/* generic setsockopts reaching us here always apply to the
2418 	 * CLC socket
2419 	 */
2420 	if (unlikely(!smc->clcsock->ops->setsockopt))
2421 		rc = -EOPNOTSUPP;
2422 	else
2423 		rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
2424 						   optval, optlen);
2425 	if (smc->clcsock->sk->sk_err) {
2426 		sk->sk_err = smc->clcsock->sk->sk_err;
2427 		sk_error_report(sk);
2428 	}
2429 
2430 	if (optlen < sizeof(int))
2431 		return -EINVAL;
2432 	if (copy_from_sockptr(&val, optval, sizeof(int)))
2433 		return -EFAULT;
2434 
2435 	lock_sock(sk);
2436 	if (rc || smc->use_fallback)
2437 		goto out;
2438 	switch (optname) {
2439 	case TCP_FASTOPEN:
2440 	case TCP_FASTOPEN_CONNECT:
2441 	case TCP_FASTOPEN_KEY:
2442 	case TCP_FASTOPEN_NO_COOKIE:
2443 		/* option not supported by SMC */
2444 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2445 			smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2446 		} else {
2447 			rc = -EINVAL;
2448 		}
2449 		break;
2450 	case TCP_NODELAY:
2451 		if (sk->sk_state != SMC_INIT &&
2452 		    sk->sk_state != SMC_LISTEN &&
2453 		    sk->sk_state != SMC_CLOSED) {
2454 			if (val) {
2455 				SMC_STAT_INC(smc, ndly_cnt);
2456 				mod_delayed_work(smc->conn.lgr->tx_wq,
2457 						 &smc->conn.tx_work, 0);
2458 			}
2459 		}
2460 		break;
2461 	case TCP_CORK:
2462 		if (sk->sk_state != SMC_INIT &&
2463 		    sk->sk_state != SMC_LISTEN &&
2464 		    sk->sk_state != SMC_CLOSED) {
2465 			if (!val) {
2466 				SMC_STAT_INC(smc, cork_cnt);
2467 				mod_delayed_work(smc->conn.lgr->tx_wq,
2468 						 &smc->conn.tx_work, 0);
2469 			}
2470 		}
2471 		break;
2472 	case TCP_DEFER_ACCEPT:
2473 		smc->sockopt_defer_accept = val;
2474 		break;
2475 	default:
2476 		break;
2477 	}
2478 out:
2479 	release_sock(sk);
2480 
2481 	return rc;
2482 }
2483 
2484 static int smc_getsockopt(struct socket *sock, int level, int optname,
2485 			  char __user *optval, int __user *optlen)
2486 {
2487 	struct smc_sock *smc;
2488 
2489 	smc = smc_sk(sock->sk);
2490 	/* socket options apply to the CLC socket */
2491 	if (unlikely(!smc->clcsock->ops->getsockopt))
2492 		return -EOPNOTSUPP;
2493 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
2494 					     optval, optlen);
2495 }
2496 
2497 static int smc_ioctl(struct socket *sock, unsigned int cmd,
2498 		     unsigned long arg)
2499 {
2500 	union smc_host_cursor cons, urg;
2501 	struct smc_connection *conn;
2502 	struct smc_sock *smc;
2503 	int answ;
2504 
2505 	smc = smc_sk(sock->sk);
2506 	conn = &smc->conn;
2507 	lock_sock(&smc->sk);
2508 	if (smc->use_fallback) {
2509 		if (!smc->clcsock) {
2510 			release_sock(&smc->sk);
2511 			return -EBADF;
2512 		}
2513 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
2514 		release_sock(&smc->sk);
2515 		return answ;
2516 	}
2517 	switch (cmd) {
2518 	case SIOCINQ: /* same as FIONREAD */
2519 		if (smc->sk.sk_state == SMC_LISTEN) {
2520 			release_sock(&smc->sk);
2521 			return -EINVAL;
2522 		}
2523 		if (smc->sk.sk_state == SMC_INIT ||
2524 		    smc->sk.sk_state == SMC_CLOSED)
2525 			answ = 0;
2526 		else
2527 			answ = atomic_read(&smc->conn.bytes_to_rcv);
2528 		break;
2529 	case SIOCOUTQ:
2530 		/* output queue size (not send + not acked) */
2531 		if (smc->sk.sk_state == SMC_LISTEN) {
2532 			release_sock(&smc->sk);
2533 			return -EINVAL;
2534 		}
2535 		if (smc->sk.sk_state == SMC_INIT ||
2536 		    smc->sk.sk_state == SMC_CLOSED)
2537 			answ = 0;
2538 		else
2539 			answ = smc->conn.sndbuf_desc->len -
2540 					atomic_read(&smc->conn.sndbuf_space);
2541 		break;
2542 	case SIOCOUTQNSD:
2543 		/* output queue size (not send only) */
2544 		if (smc->sk.sk_state == SMC_LISTEN) {
2545 			release_sock(&smc->sk);
2546 			return -EINVAL;
2547 		}
2548 		if (smc->sk.sk_state == SMC_INIT ||
2549 		    smc->sk.sk_state == SMC_CLOSED)
2550 			answ = 0;
2551 		else
2552 			answ = smc_tx_prepared_sends(&smc->conn);
2553 		break;
2554 	case SIOCATMARK:
2555 		if (smc->sk.sk_state == SMC_LISTEN) {
2556 			release_sock(&smc->sk);
2557 			return -EINVAL;
2558 		}
2559 		if (smc->sk.sk_state == SMC_INIT ||
2560 		    smc->sk.sk_state == SMC_CLOSED) {
2561 			answ = 0;
2562 		} else {
2563 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
2564 			smc_curs_copy(&urg, &conn->urg_curs, conn);
2565 			answ = smc_curs_diff(conn->rmb_desc->len,
2566 					     &cons, &urg) == 1;
2567 		}
2568 		break;
2569 	default:
2570 		release_sock(&smc->sk);
2571 		return -ENOIOCTLCMD;
2572 	}
2573 	release_sock(&smc->sk);
2574 
2575 	return put_user(answ, (int __user *)arg);
2576 }
2577 
2578 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
2579 			    int offset, size_t size, int flags)
2580 {
2581 	struct sock *sk = sock->sk;
2582 	struct smc_sock *smc;
2583 	int rc = -EPIPE;
2584 
2585 	smc = smc_sk(sk);
2586 	lock_sock(sk);
2587 	if (sk->sk_state != SMC_ACTIVE) {
2588 		release_sock(sk);
2589 		goto out;
2590 	}
2591 	release_sock(sk);
2592 	if (smc->use_fallback) {
2593 		rc = kernel_sendpage(smc->clcsock, page, offset,
2594 				     size, flags);
2595 	} else {
2596 		SMC_STAT_INC(smc, sendpage_cnt);
2597 		rc = sock_no_sendpage(sock, page, offset, size, flags);
2598 	}
2599 
2600 out:
2601 	return rc;
2602 }
2603 
2604 /* Map the affected portions of the rmbe into an spd, note the number of bytes
2605  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
2606  * updates till whenever a respective page has been fully processed.
2607  * Note that subsequent recv() calls have to wait till all splice() processing
2608  * completed.
2609  */
2610 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
2611 			       struct pipe_inode_info *pipe, size_t len,
2612 			       unsigned int flags)
2613 {
2614 	struct sock *sk = sock->sk;
2615 	struct smc_sock *smc;
2616 	int rc = -ENOTCONN;
2617 
2618 	smc = smc_sk(sk);
2619 	lock_sock(sk);
2620 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2621 		/* socket was connected before, no more data to read */
2622 		rc = 0;
2623 		goto out;
2624 	}
2625 	if (sk->sk_state == SMC_INIT ||
2626 	    sk->sk_state == SMC_LISTEN ||
2627 	    sk->sk_state == SMC_CLOSED)
2628 		goto out;
2629 
2630 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2631 		rc = 0;
2632 		goto out;
2633 	}
2634 
2635 	if (smc->use_fallback) {
2636 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
2637 						    pipe, len, flags);
2638 	} else {
2639 		if (*ppos) {
2640 			rc = -ESPIPE;
2641 			goto out;
2642 		}
2643 		if (flags & SPLICE_F_NONBLOCK)
2644 			flags = MSG_DONTWAIT;
2645 		else
2646 			flags = 0;
2647 		SMC_STAT_INC(smc, splice_cnt);
2648 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
2649 	}
2650 out:
2651 	release_sock(sk);
2652 
2653 	return rc;
2654 }
2655 
2656 /* must look like tcp */
2657 static const struct proto_ops smc_sock_ops = {
2658 	.family		= PF_SMC,
2659 	.owner		= THIS_MODULE,
2660 	.release	= smc_release,
2661 	.bind		= smc_bind,
2662 	.connect	= smc_connect,
2663 	.socketpair	= sock_no_socketpair,
2664 	.accept		= smc_accept,
2665 	.getname	= smc_getname,
2666 	.poll		= smc_poll,
2667 	.ioctl		= smc_ioctl,
2668 	.listen		= smc_listen,
2669 	.shutdown	= smc_shutdown,
2670 	.setsockopt	= smc_setsockopt,
2671 	.getsockopt	= smc_getsockopt,
2672 	.sendmsg	= smc_sendmsg,
2673 	.recvmsg	= smc_recvmsg,
2674 	.mmap		= sock_no_mmap,
2675 	.sendpage	= smc_sendpage,
2676 	.splice_read	= smc_splice_read,
2677 };
2678 
2679 static int smc_create(struct net *net, struct socket *sock, int protocol,
2680 		      int kern)
2681 {
2682 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
2683 	struct smc_sock *smc;
2684 	struct sock *sk;
2685 	int rc;
2686 
2687 	rc = -ESOCKTNOSUPPORT;
2688 	if (sock->type != SOCK_STREAM)
2689 		goto out;
2690 
2691 	rc = -EPROTONOSUPPORT;
2692 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
2693 		goto out;
2694 
2695 	rc = -ENOBUFS;
2696 	sock->ops = &smc_sock_ops;
2697 	sk = smc_sock_alloc(net, sock, protocol);
2698 	if (!sk)
2699 		goto out;
2700 
2701 	/* create internal TCP socket for CLC handshake and fallback */
2702 	smc = smc_sk(sk);
2703 	smc->use_fallback = false; /* assume rdma capability first */
2704 	smc->fallback_rsn = 0;
2705 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
2706 			      &smc->clcsock);
2707 	if (rc) {
2708 		sk_common_release(sk);
2709 		goto out;
2710 	}
2711 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
2712 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
2713 
2714 out:
2715 	return rc;
2716 }
2717 
2718 static const struct net_proto_family smc_sock_family_ops = {
2719 	.family	= PF_SMC,
2720 	.owner	= THIS_MODULE,
2721 	.create	= smc_create,
2722 };
2723 
2724 unsigned int smc_net_id;
2725 
2726 static __net_init int smc_net_init(struct net *net)
2727 {
2728 	return smc_pnet_net_init(net);
2729 }
2730 
2731 static void __net_exit smc_net_exit(struct net *net)
2732 {
2733 	smc_pnet_net_exit(net);
2734 }
2735 
2736 static __net_init int smc_net_stat_init(struct net *net)
2737 {
2738 	return smc_stats_init(net);
2739 }
2740 
2741 static void __net_exit smc_net_stat_exit(struct net *net)
2742 {
2743 	smc_stats_exit(net);
2744 }
2745 
2746 static struct pernet_operations smc_net_ops = {
2747 	.init = smc_net_init,
2748 	.exit = smc_net_exit,
2749 	.id   = &smc_net_id,
2750 	.size = sizeof(struct smc_net),
2751 };
2752 
2753 static struct pernet_operations smc_net_stat_ops = {
2754 	.init = smc_net_stat_init,
2755 	.exit = smc_net_stat_exit,
2756 };
2757 
2758 static int __init smc_init(void)
2759 {
2760 	int rc;
2761 
2762 	rc = register_pernet_subsys(&smc_net_ops);
2763 	if (rc)
2764 		return rc;
2765 
2766 	rc = register_pernet_subsys(&smc_net_stat_ops);
2767 	if (rc)
2768 		return rc;
2769 
2770 	smc_ism_init();
2771 	smc_clc_init();
2772 
2773 	rc = smc_nl_init();
2774 	if (rc)
2775 		goto out_pernet_subsys;
2776 
2777 	rc = smc_pnet_init();
2778 	if (rc)
2779 		goto out_nl;
2780 
2781 	rc = -ENOMEM;
2782 	smc_hs_wq = alloc_workqueue("smc_hs_wq", 0, 0);
2783 	if (!smc_hs_wq)
2784 		goto out_pnet;
2785 
2786 	smc_close_wq = alloc_workqueue("smc_close_wq", 0, 0);
2787 	if (!smc_close_wq)
2788 		goto out_alloc_hs_wq;
2789 
2790 	rc = smc_core_init();
2791 	if (rc) {
2792 		pr_err("%s: smc_core_init fails with %d\n", __func__, rc);
2793 		goto out_alloc_wqs;
2794 	}
2795 
2796 	rc = smc_llc_init();
2797 	if (rc) {
2798 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
2799 		goto out_core;
2800 	}
2801 
2802 	rc = smc_cdc_init();
2803 	if (rc) {
2804 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
2805 		goto out_core;
2806 	}
2807 
2808 	rc = proto_register(&smc_proto, 1);
2809 	if (rc) {
2810 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
2811 		goto out_core;
2812 	}
2813 
2814 	rc = proto_register(&smc_proto6, 1);
2815 	if (rc) {
2816 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
2817 		goto out_proto;
2818 	}
2819 
2820 	rc = sock_register(&smc_sock_family_ops);
2821 	if (rc) {
2822 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
2823 		goto out_proto6;
2824 	}
2825 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
2826 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
2827 
2828 	rc = smc_ib_register_client();
2829 	if (rc) {
2830 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
2831 		goto out_sock;
2832 	}
2833 
2834 	static_branch_enable(&tcp_have_smc);
2835 	return 0;
2836 
2837 out_sock:
2838 	sock_unregister(PF_SMC);
2839 out_proto6:
2840 	proto_unregister(&smc_proto6);
2841 out_proto:
2842 	proto_unregister(&smc_proto);
2843 out_core:
2844 	smc_core_exit();
2845 out_alloc_wqs:
2846 	destroy_workqueue(smc_close_wq);
2847 out_alloc_hs_wq:
2848 	destroy_workqueue(smc_hs_wq);
2849 out_pnet:
2850 	smc_pnet_exit();
2851 out_nl:
2852 	smc_nl_exit();
2853 out_pernet_subsys:
2854 	unregister_pernet_subsys(&smc_net_ops);
2855 
2856 	return rc;
2857 }
2858 
2859 static void __exit smc_exit(void)
2860 {
2861 	static_branch_disable(&tcp_have_smc);
2862 	sock_unregister(PF_SMC);
2863 	smc_core_exit();
2864 	smc_ib_unregister_client();
2865 	destroy_workqueue(smc_close_wq);
2866 	destroy_workqueue(smc_hs_wq);
2867 	proto_unregister(&smc_proto6);
2868 	proto_unregister(&smc_proto);
2869 	smc_pnet_exit();
2870 	smc_nl_exit();
2871 	smc_clc_exit();
2872 	unregister_pernet_subsys(&smc_net_stat_ops);
2873 	unregister_pernet_subsys(&smc_net_ops);
2874 	rcu_barrier();
2875 }
2876 
2877 module_init(smc_init);
2878 module_exit(smc_exit);
2879 
2880 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
2881 MODULE_DESCRIPTION("smc socket address family");
2882 MODULE_LICENSE("GPL");
2883 MODULE_ALIAS_NETPROTO(PF_SMC);
2884