xref: /linux/net/smc/af_smc.c (revision e0c1b49f5b674cca7b10549c53b3791d0bbc90a8)
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_LISTEN && sk->sk_state != SMC_INIT)
153 			sock_put(sk); /* passive closing */
154 		if (sk->sk_state == SMC_LISTEN) {
155 			/* wake up clcsock accept */
156 			rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
157 		}
158 		sk->sk_state = SMC_CLOSED;
159 		sk->sk_state_change(sk);
160 		smc_restore_fallback_changes(smc);
161 	}
162 
163 	sk->sk_prot->unhash(sk);
164 
165 	if (sk->sk_state == SMC_CLOSED) {
166 		if (smc->clcsock) {
167 			release_sock(sk);
168 			smc_clcsock_release(smc);
169 			lock_sock(sk);
170 		}
171 		if (!smc->use_fallback)
172 			smc_conn_free(&smc->conn);
173 	}
174 
175 	return rc;
176 }
177 
178 static int smc_release(struct socket *sock)
179 {
180 	struct sock *sk = sock->sk;
181 	struct smc_sock *smc;
182 	int rc = 0;
183 
184 	if (!sk)
185 		goto out;
186 
187 	sock_hold(sk); /* sock_put below */
188 	smc = smc_sk(sk);
189 
190 	/* cleanup for a dangling non-blocking connect */
191 	if (smc->connect_nonblock && sk->sk_state == SMC_INIT)
192 		tcp_abort(smc->clcsock->sk, ECONNABORTED);
193 	flush_work(&smc->connect_work);
194 
195 	if (sk->sk_state == SMC_LISTEN)
196 		/* smc_close_non_accepted() is called and acquires
197 		 * sock lock for child sockets again
198 		 */
199 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
200 	else
201 		lock_sock(sk);
202 
203 	rc = __smc_release(smc);
204 
205 	/* detach socket */
206 	sock_orphan(sk);
207 	sock->sk = NULL;
208 	release_sock(sk);
209 
210 	sock_put(sk); /* sock_hold above */
211 	sock_put(sk); /* final sock_put */
212 out:
213 	return rc;
214 }
215 
216 static void smc_destruct(struct sock *sk)
217 {
218 	if (sk->sk_state != SMC_CLOSED)
219 		return;
220 	if (!sock_flag(sk, SOCK_DEAD))
221 		return;
222 
223 	sk_refcnt_debug_dec(sk);
224 }
225 
226 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
227 				   int protocol)
228 {
229 	struct smc_sock *smc;
230 	struct proto *prot;
231 	struct sock *sk;
232 
233 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
234 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
235 	if (!sk)
236 		return NULL;
237 
238 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
239 	sk->sk_state = SMC_INIT;
240 	sk->sk_destruct = smc_destruct;
241 	sk->sk_protocol = protocol;
242 	smc = smc_sk(sk);
243 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
244 	INIT_WORK(&smc->connect_work, smc_connect_work);
245 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
246 	INIT_LIST_HEAD(&smc->accept_q);
247 	spin_lock_init(&smc->accept_q_lock);
248 	spin_lock_init(&smc->conn.send_lock);
249 	sk->sk_prot->hash(sk);
250 	sk_refcnt_debug_inc(sk);
251 	mutex_init(&smc->clcsock_release_lock);
252 
253 	return sk;
254 }
255 
256 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
257 		    int addr_len)
258 {
259 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
260 	struct sock *sk = sock->sk;
261 	struct smc_sock *smc;
262 	int rc;
263 
264 	smc = smc_sk(sk);
265 
266 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
267 	rc = -EINVAL;
268 	if (addr_len < sizeof(struct sockaddr_in))
269 		goto out;
270 
271 	rc = -EAFNOSUPPORT;
272 	if (addr->sin_family != AF_INET &&
273 	    addr->sin_family != AF_INET6 &&
274 	    addr->sin_family != AF_UNSPEC)
275 		goto out;
276 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
277 	if (addr->sin_family == AF_UNSPEC &&
278 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
279 		goto out;
280 
281 	lock_sock(sk);
282 
283 	/* Check if socket is already active */
284 	rc = -EINVAL;
285 	if (sk->sk_state != SMC_INIT || smc->connect_nonblock)
286 		goto out_rel;
287 
288 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
289 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
290 
291 out_rel:
292 	release_sock(sk);
293 out:
294 	return rc;
295 }
296 
297 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
298 				   unsigned long mask)
299 {
300 	/* options we don't get control via setsockopt for */
301 	nsk->sk_type = osk->sk_type;
302 	nsk->sk_sndbuf = osk->sk_sndbuf;
303 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
304 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
305 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
306 	nsk->sk_mark = osk->sk_mark;
307 	nsk->sk_priority = osk->sk_priority;
308 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
309 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
310 	nsk->sk_err = osk->sk_err;
311 
312 	nsk->sk_flags &= ~mask;
313 	nsk->sk_flags |= osk->sk_flags & mask;
314 }
315 
316 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
317 			     (1UL << SOCK_KEEPOPEN) | \
318 			     (1UL << SOCK_LINGER) | \
319 			     (1UL << SOCK_BROADCAST) | \
320 			     (1UL << SOCK_TIMESTAMP) | \
321 			     (1UL << SOCK_DBG) | \
322 			     (1UL << SOCK_RCVTSTAMP) | \
323 			     (1UL << SOCK_RCVTSTAMPNS) | \
324 			     (1UL << SOCK_LOCALROUTE) | \
325 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
326 			     (1UL << SOCK_RXQ_OVFL) | \
327 			     (1UL << SOCK_WIFI_STATUS) | \
328 			     (1UL << SOCK_NOFCS) | \
329 			     (1UL << SOCK_FILTER_LOCKED) | \
330 			     (1UL << SOCK_TSTAMP_NEW))
331 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
332  * clc socket (since smc is not called for these options from net/core)
333  */
334 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
335 {
336 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
337 }
338 
339 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
340 			     (1UL << SOCK_KEEPOPEN) | \
341 			     (1UL << SOCK_LINGER) | \
342 			     (1UL << SOCK_DBG))
343 /* copy only settings and flags relevant for smc from clc to smc socket */
344 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
345 {
346 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
347 }
348 
349 /* register the new rmb on all links */
350 static int smcr_lgr_reg_rmbs(struct smc_link *link,
351 			     struct smc_buf_desc *rmb_desc)
352 {
353 	struct smc_link_group *lgr = link->lgr;
354 	int i, rc = 0;
355 
356 	rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
357 	if (rc)
358 		return rc;
359 	/* protect against parallel smc_llc_cli_rkey_exchange() and
360 	 * parallel smcr_link_reg_rmb()
361 	 */
362 	mutex_lock(&lgr->llc_conf_mutex);
363 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
364 		if (!smc_link_active(&lgr->lnk[i]))
365 			continue;
366 		rc = smcr_link_reg_rmb(&lgr->lnk[i], rmb_desc);
367 		if (rc)
368 			goto out;
369 	}
370 
371 	/* exchange confirm_rkey msg with peer */
372 	rc = smc_llc_do_confirm_rkey(link, rmb_desc);
373 	if (rc) {
374 		rc = -EFAULT;
375 		goto out;
376 	}
377 	rmb_desc->is_conf_rkey = true;
378 out:
379 	mutex_unlock(&lgr->llc_conf_mutex);
380 	smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
381 	return rc;
382 }
383 
384 static int smcr_clnt_conf_first_link(struct smc_sock *smc)
385 {
386 	struct smc_link *link = smc->conn.lnk;
387 	struct smc_llc_qentry *qentry;
388 	int rc;
389 
390 	/* receive CONFIRM LINK request from server over RoCE fabric */
391 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
392 			      SMC_LLC_CONFIRM_LINK);
393 	if (!qentry) {
394 		struct smc_clc_msg_decline dclc;
395 
396 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
397 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
398 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
399 	}
400 	smc_llc_save_peer_uid(qentry);
401 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_REQ);
402 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
403 	if (rc)
404 		return SMC_CLC_DECL_RMBE_EC;
405 
406 	rc = smc_ib_modify_qp_rts(link);
407 	if (rc)
408 		return SMC_CLC_DECL_ERR_RDYLNK;
409 
410 	smc_wr_remember_qp_attr(link);
411 
412 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc))
413 		return SMC_CLC_DECL_ERR_REGRMB;
414 
415 	/* confirm_rkey is implicit on 1st contact */
416 	smc->conn.rmb_desc->is_conf_rkey = true;
417 
418 	/* send CONFIRM LINK response over RoCE fabric */
419 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
420 	if (rc < 0)
421 		return SMC_CLC_DECL_TIMEOUT_CL;
422 
423 	smc_llc_link_active(link);
424 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
425 
426 	/* optional 2nd link, receive ADD LINK request from server */
427 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
428 			      SMC_LLC_ADD_LINK);
429 	if (!qentry) {
430 		struct smc_clc_msg_decline dclc;
431 
432 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
433 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
434 		if (rc == -EAGAIN)
435 			rc = 0; /* no DECLINE received, go with one link */
436 		return rc;
437 	}
438 	smc_llc_flow_qentry_clr(&link->lgr->llc_flow_lcl);
439 	smc_llc_cli_add_link(link, qentry);
440 	return 0;
441 }
442 
443 static bool smc_isascii(char *hostname)
444 {
445 	int i;
446 
447 	for (i = 0; i < SMC_MAX_HOSTNAME_LEN; i++)
448 		if (!isascii(hostname[i]))
449 			return false;
450 	return true;
451 }
452 
453 static void smc_conn_save_peer_info_fce(struct smc_sock *smc,
454 					struct smc_clc_msg_accept_confirm *clc)
455 {
456 	struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
457 		(struct smc_clc_msg_accept_confirm_v2 *)clc;
458 	struct smc_clc_first_contact_ext *fce;
459 	int clc_v2_len;
460 
461 	if (clc->hdr.version == SMC_V1 ||
462 	    !(clc->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
463 		return;
464 
465 	if (smc->conn.lgr->is_smcd) {
466 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->d1.eid,
467 		       SMC_MAX_EID_LEN);
468 		clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
469 					 d1);
470 	} else {
471 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->r1.eid,
472 		       SMC_MAX_EID_LEN);
473 		clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
474 					 r1);
475 	}
476 	fce = (struct smc_clc_first_contact_ext *)(((u8 *)clc_v2) + clc_v2_len);
477 	smc->conn.lgr->peer_os = fce->os_type;
478 	smc->conn.lgr->peer_smc_release = fce->release;
479 	if (smc_isascii(fce->hostname))
480 		memcpy(smc->conn.lgr->peer_hostname, fce->hostname,
481 		       SMC_MAX_HOSTNAME_LEN);
482 }
483 
484 static void smcr_conn_save_peer_info(struct smc_sock *smc,
485 				     struct smc_clc_msg_accept_confirm *clc)
486 {
487 	int bufsize = smc_uncompress_bufsize(clc->r0.rmbe_size);
488 
489 	smc->conn.peer_rmbe_idx = clc->r0.rmbe_idx;
490 	smc->conn.local_tx_ctrl.token = ntohl(clc->r0.rmbe_alert_token);
491 	smc->conn.peer_rmbe_size = bufsize;
492 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
493 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
494 }
495 
496 static void smcd_conn_save_peer_info(struct smc_sock *smc,
497 				     struct smc_clc_msg_accept_confirm *clc)
498 {
499 	int bufsize = smc_uncompress_bufsize(clc->d0.dmbe_size);
500 
501 	smc->conn.peer_rmbe_idx = clc->d0.dmbe_idx;
502 	smc->conn.peer_token = clc->d0.token;
503 	/* msg header takes up space in the buffer */
504 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
505 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
506 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
507 }
508 
509 static void smc_conn_save_peer_info(struct smc_sock *smc,
510 				    struct smc_clc_msg_accept_confirm *clc)
511 {
512 	if (smc->conn.lgr->is_smcd)
513 		smcd_conn_save_peer_info(smc, clc);
514 	else
515 		smcr_conn_save_peer_info(smc, clc);
516 	smc_conn_save_peer_info_fce(smc, clc);
517 }
518 
519 static void smc_link_save_peer_info(struct smc_link *link,
520 				    struct smc_clc_msg_accept_confirm *clc,
521 				    struct smc_init_info *ini)
522 {
523 	link->peer_qpn = ntoh24(clc->r0.qpn);
524 	memcpy(link->peer_gid, ini->peer_gid, SMC_GID_SIZE);
525 	memcpy(link->peer_mac, ini->peer_mac, sizeof(link->peer_mac));
526 	link->peer_psn = ntoh24(clc->r0.psn);
527 	link->peer_mtu = clc->r0.qp_mtu;
528 }
529 
530 static void smc_stat_inc_fback_rsn_cnt(struct smc_sock *smc,
531 				       struct smc_stats_fback *fback_arr)
532 {
533 	int cnt;
534 
535 	for (cnt = 0; cnt < SMC_MAX_FBACK_RSN_CNT; cnt++) {
536 		if (fback_arr[cnt].fback_code == smc->fallback_rsn) {
537 			fback_arr[cnt].count++;
538 			break;
539 		}
540 		if (!fback_arr[cnt].fback_code) {
541 			fback_arr[cnt].fback_code = smc->fallback_rsn;
542 			fback_arr[cnt].count++;
543 			break;
544 		}
545 	}
546 }
547 
548 static void smc_stat_fallback(struct smc_sock *smc)
549 {
550 	struct net *net = sock_net(&smc->sk);
551 
552 	mutex_lock(&net->smc.mutex_fback_rsn);
553 	if (smc->listen_smc) {
554 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->srv);
555 		net->smc.fback_rsn->srv_fback_cnt++;
556 	} else {
557 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->clnt);
558 		net->smc.fback_rsn->clnt_fback_cnt++;
559 	}
560 	mutex_unlock(&net->smc.mutex_fback_rsn);
561 }
562 
563 static void smc_switch_to_fallback(struct smc_sock *smc, int reason_code)
564 {
565 	smc->use_fallback = true;
566 	smc->fallback_rsn = reason_code;
567 	smc_stat_fallback(smc);
568 	trace_smc_switch_to_fallback(smc, reason_code);
569 	if (smc->sk.sk_socket && smc->sk.sk_socket->file) {
570 		smc->clcsock->file = smc->sk.sk_socket->file;
571 		smc->clcsock->file->private_data = smc->clcsock;
572 		smc->clcsock->wq.fasync_list =
573 			smc->sk.sk_socket->wq.fasync_list;
574 	}
575 }
576 
577 /* fall back during connect */
578 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
579 {
580 	smc_switch_to_fallback(smc, reason_code);
581 	smc_copy_sock_settings_to_clc(smc);
582 	smc->connect_nonblock = 0;
583 	if (smc->sk.sk_state == SMC_INIT)
584 		smc->sk.sk_state = SMC_ACTIVE;
585 	return 0;
586 }
587 
588 /* decline and fall back during connect */
589 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code,
590 					u8 version)
591 {
592 	struct net *net = sock_net(&smc->sk);
593 	int rc;
594 
595 	if (reason_code < 0) { /* error, fallback is not possible */
596 		this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
597 		if (smc->sk.sk_state == SMC_INIT)
598 			sock_put(&smc->sk); /* passive closing */
599 		return reason_code;
600 	}
601 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
602 		rc = smc_clc_send_decline(smc, reason_code, version);
603 		if (rc < 0) {
604 			this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
605 			if (smc->sk.sk_state == SMC_INIT)
606 				sock_put(&smc->sk); /* passive closing */
607 			return rc;
608 		}
609 	}
610 	return smc_connect_fallback(smc, reason_code);
611 }
612 
613 static void smc_conn_abort(struct smc_sock *smc, int local_first)
614 {
615 	if (local_first)
616 		smc_lgr_cleanup_early(&smc->conn);
617 	else
618 		smc_conn_free(&smc->conn);
619 }
620 
621 /* check if there is a rdma device available for this connection. */
622 /* called for connect and listen */
623 static int smc_find_rdma_device(struct smc_sock *smc, struct smc_init_info *ini)
624 {
625 	/* PNET table look up: search active ib_device and port
626 	 * within same PNETID that also contains the ethernet device
627 	 * used for the internal TCP socket
628 	 */
629 	smc_pnet_find_roce_resource(smc->clcsock->sk, ini);
630 	if (!ini->check_smcrv2 && !ini->ib_dev)
631 		return SMC_CLC_DECL_NOSMCRDEV;
632 	if (ini->check_smcrv2 && !ini->smcrv2.ib_dev_v2)
633 		return SMC_CLC_DECL_NOSMCRDEV;
634 	return 0;
635 }
636 
637 /* check if there is an ISM device available for this connection. */
638 /* called for connect and listen */
639 static int smc_find_ism_device(struct smc_sock *smc, struct smc_init_info *ini)
640 {
641 	/* Find ISM device with same PNETID as connecting interface  */
642 	smc_pnet_find_ism_resource(smc->clcsock->sk, ini);
643 	if (!ini->ism_dev[0])
644 		return SMC_CLC_DECL_NOSMCDDEV;
645 	else
646 		ini->ism_chid[0] = smc_ism_get_chid(ini->ism_dev[0]);
647 	return 0;
648 }
649 
650 /* is chid unique for the ism devices that are already determined? */
651 static bool smc_find_ism_v2_is_unique_chid(u16 chid, struct smc_init_info *ini,
652 					   int cnt)
653 {
654 	int i = (!ini->ism_dev[0]) ? 1 : 0;
655 
656 	for (; i < cnt; i++)
657 		if (ini->ism_chid[i] == chid)
658 			return false;
659 	return true;
660 }
661 
662 /* determine possible V2 ISM devices (either without PNETID or with PNETID plus
663  * PNETID matching net_device)
664  */
665 static int smc_find_ism_v2_device_clnt(struct smc_sock *smc,
666 				       struct smc_init_info *ini)
667 {
668 	int rc = SMC_CLC_DECL_NOSMCDDEV;
669 	struct smcd_dev *smcd;
670 	int i = 1;
671 	u16 chid;
672 
673 	if (smcd_indicated(ini->smc_type_v1))
674 		rc = 0;		/* already initialized for V1 */
675 	mutex_lock(&smcd_dev_list.mutex);
676 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
677 		if (smcd->going_away || smcd == ini->ism_dev[0])
678 			continue;
679 		chid = smc_ism_get_chid(smcd);
680 		if (!smc_find_ism_v2_is_unique_chid(chid, ini, i))
681 			continue;
682 		if (!smc_pnet_is_pnetid_set(smcd->pnetid) ||
683 		    smc_pnet_is_ndev_pnetid(sock_net(&smc->sk), smcd->pnetid)) {
684 			ini->ism_dev[i] = smcd;
685 			ini->ism_chid[i] = chid;
686 			ini->is_smcd = true;
687 			rc = 0;
688 			i++;
689 			if (i > SMC_MAX_ISM_DEVS)
690 				break;
691 		}
692 	}
693 	mutex_unlock(&smcd_dev_list.mutex);
694 	ini->ism_offered_cnt = i - 1;
695 	if (!ini->ism_dev[0] && !ini->ism_dev[1])
696 		ini->smcd_version = 0;
697 
698 	return rc;
699 }
700 
701 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
702 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
703 				      struct smc_init_info *ini)
704 {
705 	if (ini->vlan_id && smc_ism_get_vlan(ini->ism_dev[0], ini->vlan_id))
706 		return SMC_CLC_DECL_ISMVLANERR;
707 	return 0;
708 }
709 
710 static int smc_find_proposal_devices(struct smc_sock *smc,
711 				     struct smc_init_info *ini)
712 {
713 	int rc = 0;
714 
715 	/* check if there is an ism device available */
716 	if (!(ini->smcd_version & SMC_V1) ||
717 	    smc_find_ism_device(smc, ini) ||
718 	    smc_connect_ism_vlan_setup(smc, ini))
719 		ini->smcd_version &= ~SMC_V1;
720 	/* else ISM V1 is supported for this connection */
721 
722 	/* check if there is an rdma device available */
723 	if (!(ini->smcr_version & SMC_V1) ||
724 	    smc_find_rdma_device(smc, ini))
725 		ini->smcr_version &= ~SMC_V1;
726 	/* else RDMA is supported for this connection */
727 
728 	ini->smc_type_v1 = smc_indicated_type(ini->smcd_version & SMC_V1,
729 					      ini->smcr_version & SMC_V1);
730 
731 	/* check if there is an ism v2 device available */
732 	if (!(ini->smcd_version & SMC_V2) ||
733 	    !smc_ism_is_v2_capable() ||
734 	    smc_find_ism_v2_device_clnt(smc, ini))
735 		ini->smcd_version &= ~SMC_V2;
736 
737 	/* check if there is an rdma v2 device available */
738 	ini->check_smcrv2 = true;
739 	ini->smcrv2.saddr = smc->clcsock->sk->sk_rcv_saddr;
740 	if (!(ini->smcr_version & SMC_V2) ||
741 	    smc->clcsock->sk->sk_family != AF_INET ||
742 	    !smc_clc_ueid_count() ||
743 	    smc_find_rdma_device(smc, ini))
744 		ini->smcr_version &= ~SMC_V2;
745 	ini->check_smcrv2 = false;
746 
747 	ini->smc_type_v2 = smc_indicated_type(ini->smcd_version & SMC_V2,
748 					      ini->smcr_version & SMC_V2);
749 
750 	/* if neither ISM nor RDMA are supported, fallback */
751 	if (ini->smc_type_v1 == SMC_TYPE_N && ini->smc_type_v2 == SMC_TYPE_N)
752 		rc = SMC_CLC_DECL_NOSMCDEV;
753 
754 	return rc;
755 }
756 
757 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
758  * used, the VLAN ID will be registered again during the connection setup.
759  */
760 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc,
761 					struct smc_init_info *ini)
762 {
763 	if (!smcd_indicated(ini->smc_type_v1))
764 		return 0;
765 	if (ini->vlan_id && smc_ism_put_vlan(ini->ism_dev[0], ini->vlan_id))
766 		return SMC_CLC_DECL_CNFERR;
767 	return 0;
768 }
769 
770 #define SMC_CLC_MAX_ACCEPT_LEN \
771 	(sizeof(struct smc_clc_msg_accept_confirm_v2) + \
772 	 sizeof(struct smc_clc_first_contact_ext) + \
773 	 sizeof(struct smc_clc_msg_trail))
774 
775 /* CLC handshake during connect */
776 static int smc_connect_clc(struct smc_sock *smc,
777 			   struct smc_clc_msg_accept_confirm_v2 *aclc2,
778 			   struct smc_init_info *ini)
779 {
780 	int rc = 0;
781 
782 	/* do inband token exchange */
783 	rc = smc_clc_send_proposal(smc, ini);
784 	if (rc)
785 		return rc;
786 	/* receive SMC Accept CLC message */
787 	return smc_clc_wait_msg(smc, aclc2, SMC_CLC_MAX_ACCEPT_LEN,
788 				SMC_CLC_ACCEPT, CLC_WAIT_TIME);
789 }
790 
791 void smc_fill_gid_list(struct smc_link_group *lgr,
792 		       struct smc_gidlist *gidlist,
793 		       struct smc_ib_device *known_dev, u8 *known_gid)
794 {
795 	struct smc_init_info *alt_ini = NULL;
796 
797 	memset(gidlist, 0, sizeof(*gidlist));
798 	memcpy(gidlist->list[gidlist->len++], known_gid, SMC_GID_SIZE);
799 
800 	alt_ini = kzalloc(sizeof(*alt_ini), GFP_KERNEL);
801 	if (!alt_ini)
802 		goto out;
803 
804 	alt_ini->vlan_id = lgr->vlan_id;
805 	alt_ini->check_smcrv2 = true;
806 	alt_ini->smcrv2.saddr = lgr->saddr;
807 	smc_pnet_find_alt_roce(lgr, alt_ini, known_dev);
808 
809 	if (!alt_ini->smcrv2.ib_dev_v2)
810 		goto out;
811 
812 	memcpy(gidlist->list[gidlist->len++], alt_ini->smcrv2.ib_gid_v2,
813 	       SMC_GID_SIZE);
814 
815 out:
816 	kfree(alt_ini);
817 }
818 
819 static int smc_connect_rdma_v2_prepare(struct smc_sock *smc,
820 				       struct smc_clc_msg_accept_confirm *aclc,
821 				       struct smc_init_info *ini)
822 {
823 	struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
824 		(struct smc_clc_msg_accept_confirm_v2 *)aclc;
825 	struct smc_clc_first_contact_ext *fce =
826 		(struct smc_clc_first_contact_ext *)
827 			(((u8 *)clc_v2) + sizeof(*clc_v2));
828 
829 	if (!ini->first_contact_peer || aclc->hdr.version == SMC_V1)
830 		return 0;
831 
832 	if (fce->v2_direct) {
833 		memcpy(ini->smcrv2.nexthop_mac, &aclc->r0.lcl.mac, ETH_ALEN);
834 		ini->smcrv2.uses_gateway = false;
835 	} else {
836 		if (smc_ib_find_route(smc->clcsock->sk->sk_rcv_saddr,
837 				      smc_ib_gid_to_ipv4(aclc->r0.lcl.gid),
838 				      ini->smcrv2.nexthop_mac,
839 				      &ini->smcrv2.uses_gateway))
840 			return SMC_CLC_DECL_NOROUTE;
841 		if (!ini->smcrv2.uses_gateway) {
842 			/* mismatch: peer claims indirect, but its direct */
843 			return SMC_CLC_DECL_NOINDIRECT;
844 		}
845 	}
846 	return 0;
847 }
848 
849 /* setup for RDMA connection of client */
850 static int smc_connect_rdma(struct smc_sock *smc,
851 			    struct smc_clc_msg_accept_confirm *aclc,
852 			    struct smc_init_info *ini)
853 {
854 	int i, reason_code = 0;
855 	struct smc_link *link;
856 	u8 *eid = NULL;
857 
858 	ini->is_smcd = false;
859 	ini->ib_clcqpn = ntoh24(aclc->r0.qpn);
860 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
861 	memcpy(ini->peer_systemid, aclc->r0.lcl.id_for_peer, SMC_SYSTEMID_LEN);
862 	memcpy(ini->peer_gid, aclc->r0.lcl.gid, SMC_GID_SIZE);
863 	memcpy(ini->peer_mac, aclc->r0.lcl.mac, ETH_ALEN);
864 
865 	reason_code = smc_connect_rdma_v2_prepare(smc, aclc, ini);
866 	if (reason_code)
867 		return reason_code;
868 
869 	mutex_lock(&smc_client_lgr_pending);
870 	reason_code = smc_conn_create(smc, ini);
871 	if (reason_code) {
872 		mutex_unlock(&smc_client_lgr_pending);
873 		return reason_code;
874 	}
875 
876 	smc_conn_save_peer_info(smc, aclc);
877 
878 	if (ini->first_contact_local) {
879 		link = smc->conn.lnk;
880 	} else {
881 		/* set link that was assigned by server */
882 		link = NULL;
883 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
884 			struct smc_link *l = &smc->conn.lgr->lnk[i];
885 
886 			if (l->peer_qpn == ntoh24(aclc->r0.qpn) &&
887 			    !memcmp(l->peer_gid, &aclc->r0.lcl.gid,
888 				    SMC_GID_SIZE) &&
889 			    (aclc->hdr.version > SMC_V1 ||
890 			     !memcmp(l->peer_mac, &aclc->r0.lcl.mac,
891 				     sizeof(l->peer_mac)))) {
892 				link = l;
893 				break;
894 			}
895 		}
896 		if (!link) {
897 			reason_code = SMC_CLC_DECL_NOSRVLINK;
898 			goto connect_abort;
899 		}
900 		smc_switch_link_and_count(&smc->conn, link);
901 	}
902 
903 	/* create send buffer and rmb */
904 	if (smc_buf_create(smc, false)) {
905 		reason_code = SMC_CLC_DECL_MEM;
906 		goto connect_abort;
907 	}
908 
909 	if (ini->first_contact_local)
910 		smc_link_save_peer_info(link, aclc, ini);
911 
912 	if (smc_rmb_rtoken_handling(&smc->conn, link, aclc)) {
913 		reason_code = SMC_CLC_DECL_ERR_RTOK;
914 		goto connect_abort;
915 	}
916 
917 	smc_close_init(smc);
918 	smc_rx_init(smc);
919 
920 	if (ini->first_contact_local) {
921 		if (smc_ib_ready_link(link)) {
922 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
923 			goto connect_abort;
924 		}
925 	} else {
926 		if (smcr_lgr_reg_rmbs(link, smc->conn.rmb_desc)) {
927 			reason_code = SMC_CLC_DECL_ERR_REGRMB;
928 			goto connect_abort;
929 		}
930 	}
931 	smc_rmb_sync_sg_for_device(&smc->conn);
932 
933 	if (aclc->hdr.version > SMC_V1) {
934 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
935 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
936 
937 		eid = clc_v2->r1.eid;
938 		if (ini->first_contact_local)
939 			smc_fill_gid_list(link->lgr, &ini->smcrv2.gidlist,
940 					  link->smcibdev, link->gid);
941 	}
942 
943 	reason_code = smc_clc_send_confirm(smc, ini->first_contact_local,
944 					   aclc->hdr.version, eid, ini);
945 	if (reason_code)
946 		goto connect_abort;
947 
948 	smc_tx_init(smc);
949 
950 	if (ini->first_contact_local) {
951 		/* QP confirmation over RoCE fabric */
952 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
953 		reason_code = smcr_clnt_conf_first_link(smc);
954 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
955 		if (reason_code)
956 			goto connect_abort;
957 	}
958 	mutex_unlock(&smc_client_lgr_pending);
959 
960 	smc_copy_sock_settings_to_clc(smc);
961 	smc->connect_nonblock = 0;
962 	if (smc->sk.sk_state == SMC_INIT)
963 		smc->sk.sk_state = SMC_ACTIVE;
964 
965 	return 0;
966 connect_abort:
967 	smc_conn_abort(smc, ini->first_contact_local);
968 	mutex_unlock(&smc_client_lgr_pending);
969 	smc->connect_nonblock = 0;
970 
971 	return reason_code;
972 }
973 
974 /* The server has chosen one of the proposed ISM devices for the communication.
975  * Determine from the CHID of the received CLC ACCEPT the ISM device chosen.
976  */
977 static int
978 smc_v2_determine_accepted_chid(struct smc_clc_msg_accept_confirm_v2 *aclc,
979 			       struct smc_init_info *ini)
980 {
981 	int i;
982 
983 	for (i = 0; i < ini->ism_offered_cnt + 1; i++) {
984 		if (ini->ism_chid[i] == ntohs(aclc->d1.chid)) {
985 			ini->ism_selected = i;
986 			return 0;
987 		}
988 	}
989 
990 	return -EPROTO;
991 }
992 
993 /* setup for ISM connection of client */
994 static int smc_connect_ism(struct smc_sock *smc,
995 			   struct smc_clc_msg_accept_confirm *aclc,
996 			   struct smc_init_info *ini)
997 {
998 	u8 *eid = NULL;
999 	int rc = 0;
1000 
1001 	ini->is_smcd = true;
1002 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
1003 
1004 	if (aclc->hdr.version == SMC_V2) {
1005 		struct smc_clc_msg_accept_confirm_v2 *aclc_v2 =
1006 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1007 
1008 		rc = smc_v2_determine_accepted_chid(aclc_v2, ini);
1009 		if (rc)
1010 			return rc;
1011 	}
1012 	ini->ism_peer_gid[ini->ism_selected] = aclc->d0.gid;
1013 
1014 	/* there is only one lgr role for SMC-D; use server lock */
1015 	mutex_lock(&smc_server_lgr_pending);
1016 	rc = smc_conn_create(smc, ini);
1017 	if (rc) {
1018 		mutex_unlock(&smc_server_lgr_pending);
1019 		return rc;
1020 	}
1021 
1022 	/* Create send and receive buffers */
1023 	rc = smc_buf_create(smc, true);
1024 	if (rc) {
1025 		rc = (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB : SMC_CLC_DECL_MEM;
1026 		goto connect_abort;
1027 	}
1028 
1029 	smc_conn_save_peer_info(smc, aclc);
1030 	smc_close_init(smc);
1031 	smc_rx_init(smc);
1032 	smc_tx_init(smc);
1033 
1034 	if (aclc->hdr.version > SMC_V1) {
1035 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
1036 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1037 
1038 		eid = clc_v2->d1.eid;
1039 	}
1040 
1041 	rc = smc_clc_send_confirm(smc, ini->first_contact_local,
1042 				  aclc->hdr.version, eid, NULL);
1043 	if (rc)
1044 		goto connect_abort;
1045 	mutex_unlock(&smc_server_lgr_pending);
1046 
1047 	smc_copy_sock_settings_to_clc(smc);
1048 	smc->connect_nonblock = 0;
1049 	if (smc->sk.sk_state == SMC_INIT)
1050 		smc->sk.sk_state = SMC_ACTIVE;
1051 
1052 	return 0;
1053 connect_abort:
1054 	smc_conn_abort(smc, ini->first_contact_local);
1055 	mutex_unlock(&smc_server_lgr_pending);
1056 	smc->connect_nonblock = 0;
1057 
1058 	return rc;
1059 }
1060 
1061 /* check if received accept type and version matches a proposed one */
1062 static int smc_connect_check_aclc(struct smc_init_info *ini,
1063 				  struct smc_clc_msg_accept_confirm *aclc)
1064 {
1065 	if (aclc->hdr.typev1 != SMC_TYPE_R &&
1066 	    aclc->hdr.typev1 != SMC_TYPE_D)
1067 		return SMC_CLC_DECL_MODEUNSUPP;
1068 
1069 	if (aclc->hdr.version >= SMC_V2) {
1070 		if ((aclc->hdr.typev1 == SMC_TYPE_R &&
1071 		     !smcr_indicated(ini->smc_type_v2)) ||
1072 		    (aclc->hdr.typev1 == SMC_TYPE_D &&
1073 		     !smcd_indicated(ini->smc_type_v2)))
1074 			return SMC_CLC_DECL_MODEUNSUPP;
1075 	} else {
1076 		if ((aclc->hdr.typev1 == SMC_TYPE_R &&
1077 		     !smcr_indicated(ini->smc_type_v1)) ||
1078 		    (aclc->hdr.typev1 == SMC_TYPE_D &&
1079 		     !smcd_indicated(ini->smc_type_v1)))
1080 			return SMC_CLC_DECL_MODEUNSUPP;
1081 	}
1082 
1083 	return 0;
1084 }
1085 
1086 /* perform steps before actually connecting */
1087 static int __smc_connect(struct smc_sock *smc)
1088 {
1089 	u8 version = smc_ism_is_v2_capable() ? SMC_V2 : SMC_V1;
1090 	struct smc_clc_msg_accept_confirm_v2 *aclc2;
1091 	struct smc_clc_msg_accept_confirm *aclc;
1092 	struct smc_init_info *ini = NULL;
1093 	u8 *buf = NULL;
1094 	int rc = 0;
1095 
1096 	if (smc->use_fallback)
1097 		return smc_connect_fallback(smc, smc->fallback_rsn);
1098 
1099 	/* if peer has not signalled SMC-capability, fall back */
1100 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
1101 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
1102 
1103 	/* IPSec connections opt out of SMC optimizations */
1104 	if (using_ipsec(smc))
1105 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC,
1106 						    version);
1107 
1108 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1109 	if (!ini)
1110 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_MEM,
1111 						    version);
1112 
1113 	ini->smcd_version = SMC_V1 | SMC_V2;
1114 	ini->smcr_version = SMC_V1 | SMC_V2;
1115 	ini->smc_type_v1 = SMC_TYPE_B;
1116 	ini->smc_type_v2 = SMC_TYPE_B;
1117 
1118 	/* get vlan id from IP device */
1119 	if (smc_vlan_by_tcpsk(smc->clcsock, ini)) {
1120 		ini->smcd_version &= ~SMC_V1;
1121 		ini->smcr_version = 0;
1122 		ini->smc_type_v1 = SMC_TYPE_N;
1123 		if (!ini->smcd_version) {
1124 			rc = SMC_CLC_DECL_GETVLANERR;
1125 			goto fallback;
1126 		}
1127 	}
1128 
1129 	rc = smc_find_proposal_devices(smc, ini);
1130 	if (rc)
1131 		goto fallback;
1132 
1133 	buf = kzalloc(SMC_CLC_MAX_ACCEPT_LEN, GFP_KERNEL);
1134 	if (!buf) {
1135 		rc = SMC_CLC_DECL_MEM;
1136 		goto fallback;
1137 	}
1138 	aclc2 = (struct smc_clc_msg_accept_confirm_v2 *)buf;
1139 	aclc = (struct smc_clc_msg_accept_confirm *)aclc2;
1140 
1141 	/* perform CLC handshake */
1142 	rc = smc_connect_clc(smc, aclc2, ini);
1143 	if (rc)
1144 		goto vlan_cleanup;
1145 
1146 	/* check if smc modes and versions of CLC proposal and accept match */
1147 	rc = smc_connect_check_aclc(ini, aclc);
1148 	version = aclc->hdr.version == SMC_V1 ? SMC_V1 : SMC_V2;
1149 	if (rc)
1150 		goto vlan_cleanup;
1151 
1152 	/* depending on previous steps, connect using rdma or ism */
1153 	if (aclc->hdr.typev1 == SMC_TYPE_R) {
1154 		ini->smcr_version = version;
1155 		rc = smc_connect_rdma(smc, aclc, ini);
1156 	} else if (aclc->hdr.typev1 == SMC_TYPE_D) {
1157 		ini->smcd_version = version;
1158 		rc = smc_connect_ism(smc, aclc, ini);
1159 	}
1160 	if (rc)
1161 		goto vlan_cleanup;
1162 
1163 	SMC_STAT_CLNT_SUCC_INC(sock_net(smc->clcsock->sk), aclc);
1164 	smc_connect_ism_vlan_cleanup(smc, ini);
1165 	kfree(buf);
1166 	kfree(ini);
1167 	return 0;
1168 
1169 vlan_cleanup:
1170 	smc_connect_ism_vlan_cleanup(smc, ini);
1171 	kfree(buf);
1172 fallback:
1173 	kfree(ini);
1174 	return smc_connect_decline_fallback(smc, rc, version);
1175 }
1176 
1177 static void smc_connect_work(struct work_struct *work)
1178 {
1179 	struct smc_sock *smc = container_of(work, struct smc_sock,
1180 					    connect_work);
1181 	long timeo = smc->sk.sk_sndtimeo;
1182 	int rc = 0;
1183 
1184 	if (!timeo)
1185 		timeo = MAX_SCHEDULE_TIMEOUT;
1186 	lock_sock(smc->clcsock->sk);
1187 	if (smc->clcsock->sk->sk_err) {
1188 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
1189 	} else if ((1 << smc->clcsock->sk->sk_state) &
1190 					(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
1191 		rc = sk_stream_wait_connect(smc->clcsock->sk, &timeo);
1192 		if ((rc == -EPIPE) &&
1193 		    ((1 << smc->clcsock->sk->sk_state) &
1194 					(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))
1195 			rc = 0;
1196 	}
1197 	release_sock(smc->clcsock->sk);
1198 	lock_sock(&smc->sk);
1199 	if (rc != 0 || smc->sk.sk_err) {
1200 		smc->sk.sk_state = SMC_CLOSED;
1201 		if (rc == -EPIPE || rc == -EAGAIN)
1202 			smc->sk.sk_err = EPIPE;
1203 		else if (signal_pending(current))
1204 			smc->sk.sk_err = -sock_intr_errno(timeo);
1205 		sock_put(&smc->sk); /* passive closing */
1206 		goto out;
1207 	}
1208 
1209 	rc = __smc_connect(smc);
1210 	if (rc < 0)
1211 		smc->sk.sk_err = -rc;
1212 
1213 out:
1214 	if (!sock_flag(&smc->sk, SOCK_DEAD)) {
1215 		if (smc->sk.sk_err) {
1216 			smc->sk.sk_state_change(&smc->sk);
1217 		} else { /* allow polling before and after fallback decision */
1218 			smc->clcsock->sk->sk_write_space(smc->clcsock->sk);
1219 			smc->sk.sk_write_space(&smc->sk);
1220 		}
1221 	}
1222 	release_sock(&smc->sk);
1223 }
1224 
1225 static int smc_connect(struct socket *sock, struct sockaddr *addr,
1226 		       int alen, int flags)
1227 {
1228 	struct sock *sk = sock->sk;
1229 	struct smc_sock *smc;
1230 	int rc = -EINVAL;
1231 
1232 	smc = smc_sk(sk);
1233 
1234 	/* separate smc parameter checking to be safe */
1235 	if (alen < sizeof(addr->sa_family))
1236 		goto out_err;
1237 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
1238 		goto out_err;
1239 
1240 	lock_sock(sk);
1241 	switch (sk->sk_state) {
1242 	default:
1243 		goto out;
1244 	case SMC_ACTIVE:
1245 		rc = -EISCONN;
1246 		goto out;
1247 	case SMC_INIT:
1248 		break;
1249 	}
1250 
1251 	smc_copy_sock_settings_to_clc(smc);
1252 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1253 	if (smc->connect_nonblock) {
1254 		rc = -EALREADY;
1255 		goto out;
1256 	}
1257 	rc = kernel_connect(smc->clcsock, addr, alen, flags);
1258 	if (rc && rc != -EINPROGRESS)
1259 		goto out;
1260 
1261 	sock_hold(&smc->sk); /* sock put in passive closing */
1262 	if (smc->use_fallback)
1263 		goto out;
1264 	if (flags & O_NONBLOCK) {
1265 		if (queue_work(smc_hs_wq, &smc->connect_work))
1266 			smc->connect_nonblock = 1;
1267 		rc = -EINPROGRESS;
1268 	} else {
1269 		rc = __smc_connect(smc);
1270 		if (rc < 0)
1271 			goto out;
1272 		else
1273 			rc = 0; /* success cases including fallback */
1274 	}
1275 
1276 out:
1277 	release_sock(sk);
1278 out_err:
1279 	return rc;
1280 }
1281 
1282 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
1283 {
1284 	struct socket *new_clcsock = NULL;
1285 	struct sock *lsk = &lsmc->sk;
1286 	struct sock *new_sk;
1287 	int rc = -EINVAL;
1288 
1289 	release_sock(lsk);
1290 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
1291 	if (!new_sk) {
1292 		rc = -ENOMEM;
1293 		lsk->sk_err = ENOMEM;
1294 		*new_smc = NULL;
1295 		lock_sock(lsk);
1296 		goto out;
1297 	}
1298 	*new_smc = smc_sk(new_sk);
1299 
1300 	mutex_lock(&lsmc->clcsock_release_lock);
1301 	if (lsmc->clcsock)
1302 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, SOCK_NONBLOCK);
1303 	mutex_unlock(&lsmc->clcsock_release_lock);
1304 	lock_sock(lsk);
1305 	if  (rc < 0 && rc != -EAGAIN)
1306 		lsk->sk_err = -rc;
1307 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
1308 		new_sk->sk_prot->unhash(new_sk);
1309 		if (new_clcsock)
1310 			sock_release(new_clcsock);
1311 		new_sk->sk_state = SMC_CLOSED;
1312 		sock_set_flag(new_sk, SOCK_DEAD);
1313 		sock_put(new_sk); /* final */
1314 		*new_smc = NULL;
1315 		goto out;
1316 	}
1317 
1318 	/* new clcsock has inherited the smc listen-specific sk_data_ready
1319 	 * function; switch it back to the original sk_data_ready function
1320 	 */
1321 	new_clcsock->sk->sk_data_ready = lsmc->clcsk_data_ready;
1322 	(*new_smc)->clcsock = new_clcsock;
1323 out:
1324 	return rc;
1325 }
1326 
1327 /* add a just created sock to the accept queue of the listen sock as
1328  * candidate for a following socket accept call from user space
1329  */
1330 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
1331 {
1332 	struct smc_sock *par = smc_sk(parent);
1333 
1334 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
1335 	spin_lock(&par->accept_q_lock);
1336 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
1337 	spin_unlock(&par->accept_q_lock);
1338 	sk_acceptq_added(parent);
1339 }
1340 
1341 /* remove a socket from the accept queue of its parental listening socket */
1342 static void smc_accept_unlink(struct sock *sk)
1343 {
1344 	struct smc_sock *par = smc_sk(sk)->listen_smc;
1345 
1346 	spin_lock(&par->accept_q_lock);
1347 	list_del_init(&smc_sk(sk)->accept_q);
1348 	spin_unlock(&par->accept_q_lock);
1349 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
1350 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
1351 }
1352 
1353 /* remove a sock from the accept queue to bind it to a new socket created
1354  * for a socket accept call from user space
1355  */
1356 struct sock *smc_accept_dequeue(struct sock *parent,
1357 				struct socket *new_sock)
1358 {
1359 	struct smc_sock *isk, *n;
1360 	struct sock *new_sk;
1361 
1362 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
1363 		new_sk = (struct sock *)isk;
1364 
1365 		smc_accept_unlink(new_sk);
1366 		if (new_sk->sk_state == SMC_CLOSED) {
1367 			new_sk->sk_prot->unhash(new_sk);
1368 			if (isk->clcsock) {
1369 				sock_release(isk->clcsock);
1370 				isk->clcsock = NULL;
1371 			}
1372 			sock_put(new_sk); /* final */
1373 			continue;
1374 		}
1375 		if (new_sock) {
1376 			sock_graft(new_sk, new_sock);
1377 			if (isk->use_fallback) {
1378 				smc_sk(new_sk)->clcsock->file = new_sock->file;
1379 				isk->clcsock->file->private_data = isk->clcsock;
1380 			}
1381 		}
1382 		return new_sk;
1383 	}
1384 	return NULL;
1385 }
1386 
1387 /* clean up for a created but never accepted sock */
1388 void smc_close_non_accepted(struct sock *sk)
1389 {
1390 	struct smc_sock *smc = smc_sk(sk);
1391 
1392 	sock_hold(sk); /* sock_put below */
1393 	lock_sock(sk);
1394 	if (!sk->sk_lingertime)
1395 		/* wait for peer closing */
1396 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
1397 	__smc_release(smc);
1398 	release_sock(sk);
1399 	sock_put(sk); /* sock_hold above */
1400 	sock_put(sk); /* final sock_put */
1401 }
1402 
1403 static int smcr_serv_conf_first_link(struct smc_sock *smc)
1404 {
1405 	struct smc_link *link = smc->conn.lnk;
1406 	struct smc_llc_qentry *qentry;
1407 	int rc;
1408 
1409 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc))
1410 		return SMC_CLC_DECL_ERR_REGRMB;
1411 
1412 	/* send CONFIRM LINK request to client over the RoCE fabric */
1413 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
1414 	if (rc < 0)
1415 		return SMC_CLC_DECL_TIMEOUT_CL;
1416 
1417 	/* receive CONFIRM LINK response from client over the RoCE fabric */
1418 	qentry = smc_llc_wait(link->lgr, link, SMC_LLC_WAIT_TIME,
1419 			      SMC_LLC_CONFIRM_LINK);
1420 	if (!qentry) {
1421 		struct smc_clc_msg_decline dclc;
1422 
1423 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1424 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1425 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
1426 	}
1427 	smc_llc_save_peer_uid(qentry);
1428 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_RESP);
1429 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
1430 	if (rc)
1431 		return SMC_CLC_DECL_RMBE_EC;
1432 
1433 	/* confirm_rkey is implicit on 1st contact */
1434 	smc->conn.rmb_desc->is_conf_rkey = true;
1435 
1436 	smc_llc_link_active(link);
1437 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
1438 
1439 	/* initial contact - try to establish second link */
1440 	smc_llc_srv_add_link(link, NULL);
1441 	return 0;
1442 }
1443 
1444 /* listen worker: finish */
1445 static void smc_listen_out(struct smc_sock *new_smc)
1446 {
1447 	struct smc_sock *lsmc = new_smc->listen_smc;
1448 	struct sock *newsmcsk = &new_smc->sk;
1449 
1450 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1451 		lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1452 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1453 		release_sock(&lsmc->sk);
1454 	} else { /* no longer listening */
1455 		smc_close_non_accepted(newsmcsk);
1456 	}
1457 
1458 	/* Wake up accept */
1459 	lsmc->sk.sk_data_ready(&lsmc->sk);
1460 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1461 }
1462 
1463 /* listen worker: finish in state connected */
1464 static void smc_listen_out_connected(struct smc_sock *new_smc)
1465 {
1466 	struct sock *newsmcsk = &new_smc->sk;
1467 
1468 	sk_refcnt_debug_inc(newsmcsk);
1469 	if (newsmcsk->sk_state == SMC_INIT)
1470 		newsmcsk->sk_state = SMC_ACTIVE;
1471 
1472 	smc_listen_out(new_smc);
1473 }
1474 
1475 /* listen worker: finish in error state */
1476 static void smc_listen_out_err(struct smc_sock *new_smc)
1477 {
1478 	struct sock *newsmcsk = &new_smc->sk;
1479 	struct net *net = sock_net(newsmcsk);
1480 
1481 	this_cpu_inc(net->smc.smc_stats->srv_hshake_err_cnt);
1482 	if (newsmcsk->sk_state == SMC_INIT)
1483 		sock_put(&new_smc->sk); /* passive closing */
1484 	newsmcsk->sk_state = SMC_CLOSED;
1485 
1486 	smc_listen_out(new_smc);
1487 }
1488 
1489 /* listen worker: decline and fall back if possible */
1490 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1491 			       int local_first, u8 version)
1492 {
1493 	/* RDMA setup failed, switch back to TCP */
1494 	smc_conn_abort(new_smc, local_first);
1495 	if (reason_code < 0) { /* error, no fallback possible */
1496 		smc_listen_out_err(new_smc);
1497 		return;
1498 	}
1499 	smc_switch_to_fallback(new_smc, reason_code);
1500 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1501 		if (smc_clc_send_decline(new_smc, reason_code, version) < 0) {
1502 			smc_listen_out_err(new_smc);
1503 			return;
1504 		}
1505 	}
1506 	smc_listen_out_connected(new_smc);
1507 }
1508 
1509 /* listen worker: version checking */
1510 static int smc_listen_v2_check(struct smc_sock *new_smc,
1511 			       struct smc_clc_msg_proposal *pclc,
1512 			       struct smc_init_info *ini)
1513 {
1514 	struct smc_clc_smcd_v2_extension *pclc_smcd_v2_ext;
1515 	struct smc_clc_v2_extension *pclc_v2_ext;
1516 	int rc = SMC_CLC_DECL_PEERNOSMC;
1517 
1518 	ini->smc_type_v1 = pclc->hdr.typev1;
1519 	ini->smc_type_v2 = pclc->hdr.typev2;
1520 	ini->smcd_version = smcd_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
1521 	ini->smcr_version = smcr_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
1522 	if (pclc->hdr.version > SMC_V1) {
1523 		if (smcd_indicated(ini->smc_type_v2))
1524 			ini->smcd_version |= SMC_V2;
1525 		if (smcr_indicated(ini->smc_type_v2))
1526 			ini->smcr_version |= SMC_V2;
1527 	}
1528 	if (!(ini->smcd_version & SMC_V2) && !(ini->smcr_version & SMC_V2)) {
1529 		rc = SMC_CLC_DECL_PEERNOSMC;
1530 		goto out;
1531 	}
1532 	pclc_v2_ext = smc_get_clc_v2_ext(pclc);
1533 	if (!pclc_v2_ext) {
1534 		ini->smcd_version &= ~SMC_V2;
1535 		ini->smcr_version &= ~SMC_V2;
1536 		rc = SMC_CLC_DECL_NOV2EXT;
1537 		goto out;
1538 	}
1539 	pclc_smcd_v2_ext = smc_get_clc_smcd_v2_ext(pclc_v2_ext);
1540 	if (ini->smcd_version & SMC_V2) {
1541 		if (!smc_ism_is_v2_capable()) {
1542 			ini->smcd_version &= ~SMC_V2;
1543 			rc = SMC_CLC_DECL_NOISM2SUPP;
1544 		} else if (!pclc_smcd_v2_ext) {
1545 			ini->smcd_version &= ~SMC_V2;
1546 			rc = SMC_CLC_DECL_NOV2DEXT;
1547 		} else if (!pclc_v2_ext->hdr.eid_cnt &&
1548 			   !pclc_v2_ext->hdr.flag.seid) {
1549 			ini->smcd_version &= ~SMC_V2;
1550 			rc = SMC_CLC_DECL_NOUEID;
1551 		}
1552 	}
1553 	if (ini->smcr_version & SMC_V2) {
1554 		if (!pclc_v2_ext->hdr.eid_cnt) {
1555 			ini->smcr_version &= ~SMC_V2;
1556 			rc = SMC_CLC_DECL_NOUEID;
1557 		}
1558 	}
1559 
1560 out:
1561 	if (!ini->smcd_version && !ini->smcr_version)
1562 		return rc;
1563 
1564 	return 0;
1565 }
1566 
1567 /* listen worker: check prefixes */
1568 static int smc_listen_prfx_check(struct smc_sock *new_smc,
1569 				 struct smc_clc_msg_proposal *pclc)
1570 {
1571 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1572 	struct socket *newclcsock = new_smc->clcsock;
1573 
1574 	if (pclc->hdr.typev1 == SMC_TYPE_N)
1575 		return 0;
1576 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1577 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1578 		return SMC_CLC_DECL_DIFFPREFIX;
1579 
1580 	return 0;
1581 }
1582 
1583 /* listen worker: initialize connection and buffers */
1584 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1585 				struct smc_init_info *ini)
1586 {
1587 	int rc;
1588 
1589 	/* allocate connection / link group */
1590 	rc = smc_conn_create(new_smc, ini);
1591 	if (rc)
1592 		return rc;
1593 
1594 	/* create send buffer and rmb */
1595 	if (smc_buf_create(new_smc, false))
1596 		return SMC_CLC_DECL_MEM;
1597 
1598 	return 0;
1599 }
1600 
1601 /* listen worker: initialize connection and buffers for SMC-D */
1602 static int smc_listen_ism_init(struct smc_sock *new_smc,
1603 			       struct smc_init_info *ini)
1604 {
1605 	int rc;
1606 
1607 	rc = smc_conn_create(new_smc, ini);
1608 	if (rc)
1609 		return rc;
1610 
1611 	/* Create send and receive buffers */
1612 	rc = smc_buf_create(new_smc, true);
1613 	if (rc) {
1614 		smc_conn_abort(new_smc, ini->first_contact_local);
1615 		return (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB :
1616 					 SMC_CLC_DECL_MEM;
1617 	}
1618 
1619 	return 0;
1620 }
1621 
1622 static bool smc_is_already_selected(struct smcd_dev *smcd,
1623 				    struct smc_init_info *ini,
1624 				    int matches)
1625 {
1626 	int i;
1627 
1628 	for (i = 0; i < matches; i++)
1629 		if (smcd == ini->ism_dev[i])
1630 			return true;
1631 
1632 	return false;
1633 }
1634 
1635 /* check for ISM devices matching proposed ISM devices */
1636 static void smc_check_ism_v2_match(struct smc_init_info *ini,
1637 				   u16 proposed_chid, u64 proposed_gid,
1638 				   unsigned int *matches)
1639 {
1640 	struct smcd_dev *smcd;
1641 
1642 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
1643 		if (smcd->going_away)
1644 			continue;
1645 		if (smc_is_already_selected(smcd, ini, *matches))
1646 			continue;
1647 		if (smc_ism_get_chid(smcd) == proposed_chid &&
1648 		    !smc_ism_cantalk(proposed_gid, ISM_RESERVED_VLANID, smcd)) {
1649 			ini->ism_peer_gid[*matches] = proposed_gid;
1650 			ini->ism_dev[*matches] = smcd;
1651 			(*matches)++;
1652 			break;
1653 		}
1654 	}
1655 }
1656 
1657 static void smc_find_ism_store_rc(u32 rc, struct smc_init_info *ini)
1658 {
1659 	if (!ini->rc)
1660 		ini->rc = rc;
1661 }
1662 
1663 static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
1664 					struct smc_clc_msg_proposal *pclc,
1665 					struct smc_init_info *ini)
1666 {
1667 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
1668 	struct smc_clc_v2_extension *smc_v2_ext;
1669 	struct smc_clc_msg_smcd *pclc_smcd;
1670 	unsigned int matches = 0;
1671 	u8 smcd_version;
1672 	u8 *eid = NULL;
1673 	int i, rc;
1674 
1675 	if (!(ini->smcd_version & SMC_V2) || !smcd_indicated(ini->smc_type_v2))
1676 		goto not_found;
1677 
1678 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
1679 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
1680 	smcd_v2_ext = smc_get_clc_smcd_v2_ext(smc_v2_ext);
1681 
1682 	mutex_lock(&smcd_dev_list.mutex);
1683 	if (pclc_smcd->ism.chid)
1684 		/* check for ISM device matching proposed native ISM device */
1685 		smc_check_ism_v2_match(ini, ntohs(pclc_smcd->ism.chid),
1686 				       ntohll(pclc_smcd->ism.gid), &matches);
1687 	for (i = 1; i <= smc_v2_ext->hdr.ism_gid_cnt; i++) {
1688 		/* check for ISM devices matching proposed non-native ISM
1689 		 * devices
1690 		 */
1691 		smc_check_ism_v2_match(ini,
1692 				       ntohs(smcd_v2_ext->gidchid[i - 1].chid),
1693 				       ntohll(smcd_v2_ext->gidchid[i - 1].gid),
1694 				       &matches);
1695 	}
1696 	mutex_unlock(&smcd_dev_list.mutex);
1697 
1698 	if (!ini->ism_dev[0]) {
1699 		smc_find_ism_store_rc(SMC_CLC_DECL_NOSMCD2DEV, ini);
1700 		goto not_found;
1701 	}
1702 
1703 	smc_ism_get_system_eid(&eid);
1704 	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext,
1705 			       smcd_v2_ext->system_eid, eid))
1706 		goto not_found;
1707 
1708 	/* separate - outside the smcd_dev_list.lock */
1709 	smcd_version = ini->smcd_version;
1710 	for (i = 0; i < matches; i++) {
1711 		ini->smcd_version = SMC_V2;
1712 		ini->is_smcd = true;
1713 		ini->ism_selected = i;
1714 		rc = smc_listen_ism_init(new_smc, ini);
1715 		if (rc) {
1716 			smc_find_ism_store_rc(rc, ini);
1717 			/* try next active ISM device */
1718 			continue;
1719 		}
1720 		return; /* matching and usable V2 ISM device found */
1721 	}
1722 	/* no V2 ISM device could be initialized */
1723 	ini->smcd_version = smcd_version;	/* restore original value */
1724 	ini->negotiated_eid[0] = 0;
1725 
1726 not_found:
1727 	ini->smcd_version &= ~SMC_V2;
1728 	ini->ism_dev[0] = NULL;
1729 	ini->is_smcd = false;
1730 }
1731 
1732 static void smc_find_ism_v1_device_serv(struct smc_sock *new_smc,
1733 					struct smc_clc_msg_proposal *pclc,
1734 					struct smc_init_info *ini)
1735 {
1736 	struct smc_clc_msg_smcd *pclc_smcd = smc_get_clc_msg_smcd(pclc);
1737 	int rc = 0;
1738 
1739 	/* check if ISM V1 is available */
1740 	if (!(ini->smcd_version & SMC_V1) || !smcd_indicated(ini->smc_type_v1))
1741 		goto not_found;
1742 	ini->is_smcd = true; /* prepare ISM check */
1743 	ini->ism_peer_gid[0] = ntohll(pclc_smcd->ism.gid);
1744 	rc = smc_find_ism_device(new_smc, ini);
1745 	if (rc)
1746 		goto not_found;
1747 	ini->ism_selected = 0;
1748 	rc = smc_listen_ism_init(new_smc, ini);
1749 	if (!rc)
1750 		return;		/* V1 ISM device found */
1751 
1752 not_found:
1753 	smc_find_ism_store_rc(rc, ini);
1754 	ini->smcd_version &= ~SMC_V1;
1755 	ini->ism_dev[0] = NULL;
1756 	ini->is_smcd = false;
1757 }
1758 
1759 /* listen worker: register buffers */
1760 static int smc_listen_rdma_reg(struct smc_sock *new_smc, bool local_first)
1761 {
1762 	struct smc_connection *conn = &new_smc->conn;
1763 
1764 	if (!local_first) {
1765 		if (smcr_lgr_reg_rmbs(conn->lnk, conn->rmb_desc))
1766 			return SMC_CLC_DECL_ERR_REGRMB;
1767 	}
1768 	smc_rmb_sync_sg_for_device(&new_smc->conn);
1769 
1770 	return 0;
1771 }
1772 
1773 static void smc_find_rdma_v2_device_serv(struct smc_sock *new_smc,
1774 					 struct smc_clc_msg_proposal *pclc,
1775 					 struct smc_init_info *ini)
1776 {
1777 	struct smc_clc_v2_extension *smc_v2_ext;
1778 	u8 smcr_version;
1779 	int rc;
1780 
1781 	if (!(ini->smcr_version & SMC_V2) || !smcr_indicated(ini->smc_type_v2))
1782 		goto not_found;
1783 
1784 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
1785 	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext, NULL, NULL))
1786 		goto not_found;
1787 
1788 	/* prepare RDMA check */
1789 	memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
1790 	memcpy(ini->peer_gid, smc_v2_ext->roce, SMC_GID_SIZE);
1791 	memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
1792 	ini->check_smcrv2 = true;
1793 	ini->smcrv2.clc_sk = new_smc->clcsock->sk;
1794 	ini->smcrv2.saddr = new_smc->clcsock->sk->sk_rcv_saddr;
1795 	ini->smcrv2.daddr = smc_ib_gid_to_ipv4(smc_v2_ext->roce);
1796 	rc = smc_find_rdma_device(new_smc, ini);
1797 	if (rc) {
1798 		smc_find_ism_store_rc(rc, ini);
1799 		goto not_found;
1800 	}
1801 	if (!ini->smcrv2.uses_gateway)
1802 		memcpy(ini->smcrv2.nexthop_mac, pclc->lcl.mac, ETH_ALEN);
1803 
1804 	smcr_version = ini->smcr_version;
1805 	ini->smcr_version = SMC_V2;
1806 	rc = smc_listen_rdma_init(new_smc, ini);
1807 	if (!rc)
1808 		rc = smc_listen_rdma_reg(new_smc, ini->first_contact_local);
1809 	if (!rc)
1810 		return;
1811 	ini->smcr_version = smcr_version;
1812 	smc_find_ism_store_rc(rc, ini);
1813 
1814 not_found:
1815 	ini->smcr_version &= ~SMC_V2;
1816 	ini->check_smcrv2 = false;
1817 }
1818 
1819 static int smc_find_rdma_v1_device_serv(struct smc_sock *new_smc,
1820 					struct smc_clc_msg_proposal *pclc,
1821 					struct smc_init_info *ini)
1822 {
1823 	int rc;
1824 
1825 	if (!(ini->smcr_version & SMC_V1) || !smcr_indicated(ini->smc_type_v1))
1826 		return SMC_CLC_DECL_NOSMCDEV;
1827 
1828 	/* prepare RDMA check */
1829 	memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
1830 	memcpy(ini->peer_gid, pclc->lcl.gid, SMC_GID_SIZE);
1831 	memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
1832 	rc = smc_find_rdma_device(new_smc, ini);
1833 	if (rc) {
1834 		/* no RDMA device found */
1835 		return SMC_CLC_DECL_NOSMCDEV;
1836 	}
1837 	rc = smc_listen_rdma_init(new_smc, ini);
1838 	if (rc)
1839 		return rc;
1840 	return smc_listen_rdma_reg(new_smc, ini->first_contact_local);
1841 }
1842 
1843 /* determine the local device matching to proposal */
1844 static int smc_listen_find_device(struct smc_sock *new_smc,
1845 				  struct smc_clc_msg_proposal *pclc,
1846 				  struct smc_init_info *ini)
1847 {
1848 	int prfx_rc;
1849 
1850 	/* check for ISM device matching V2 proposed device */
1851 	smc_find_ism_v2_device_serv(new_smc, pclc, ini);
1852 	if (ini->ism_dev[0])
1853 		return 0;
1854 
1855 	/* check for matching IP prefix and subnet length (V1) */
1856 	prfx_rc = smc_listen_prfx_check(new_smc, pclc);
1857 	if (prfx_rc)
1858 		smc_find_ism_store_rc(prfx_rc, ini);
1859 
1860 	/* get vlan id from IP device */
1861 	if (smc_vlan_by_tcpsk(new_smc->clcsock, ini))
1862 		return ini->rc ?: SMC_CLC_DECL_GETVLANERR;
1863 
1864 	/* check for ISM device matching V1 proposed device */
1865 	if (!prfx_rc)
1866 		smc_find_ism_v1_device_serv(new_smc, pclc, ini);
1867 	if (ini->ism_dev[0])
1868 		return 0;
1869 
1870 	if (!smcr_indicated(pclc->hdr.typev1) &&
1871 	    !smcr_indicated(pclc->hdr.typev2))
1872 		/* skip RDMA and decline */
1873 		return ini->rc ?: SMC_CLC_DECL_NOSMCDDEV;
1874 
1875 	/* check if RDMA V2 is available */
1876 	smc_find_rdma_v2_device_serv(new_smc, pclc, ini);
1877 	if (ini->smcrv2.ib_dev_v2)
1878 		return 0;
1879 
1880 	/* check if RDMA V1 is available */
1881 	if (!prfx_rc) {
1882 		int rc;
1883 
1884 		rc = smc_find_rdma_v1_device_serv(new_smc, pclc, ini);
1885 		smc_find_ism_store_rc(rc, ini);
1886 		return (!rc) ? 0 : ini->rc;
1887 	}
1888 	return SMC_CLC_DECL_NOSMCDEV;
1889 }
1890 
1891 /* listen worker: finish RDMA setup */
1892 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
1893 				  struct smc_clc_msg_accept_confirm *cclc,
1894 				  bool local_first,
1895 				  struct smc_init_info *ini)
1896 {
1897 	struct smc_link *link = new_smc->conn.lnk;
1898 	int reason_code = 0;
1899 
1900 	if (local_first)
1901 		smc_link_save_peer_info(link, cclc, ini);
1902 
1903 	if (smc_rmb_rtoken_handling(&new_smc->conn, link, cclc))
1904 		return SMC_CLC_DECL_ERR_RTOK;
1905 
1906 	if (local_first) {
1907 		if (smc_ib_ready_link(link))
1908 			return SMC_CLC_DECL_ERR_RDYLNK;
1909 		/* QP confirmation over RoCE fabric */
1910 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
1911 		reason_code = smcr_serv_conf_first_link(new_smc);
1912 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
1913 	}
1914 	return reason_code;
1915 }
1916 
1917 /* setup for connection of server */
1918 static void smc_listen_work(struct work_struct *work)
1919 {
1920 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
1921 						smc_listen_work);
1922 	struct socket *newclcsock = new_smc->clcsock;
1923 	struct smc_clc_msg_accept_confirm *cclc;
1924 	struct smc_clc_msg_proposal_area *buf;
1925 	struct smc_clc_msg_proposal *pclc;
1926 	struct smc_init_info *ini = NULL;
1927 	u8 proposal_version = SMC_V1;
1928 	u8 accept_version;
1929 	int rc = 0;
1930 
1931 	if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
1932 		return smc_listen_out_err(new_smc);
1933 
1934 	if (new_smc->use_fallback) {
1935 		smc_listen_out_connected(new_smc);
1936 		return;
1937 	}
1938 
1939 	/* check if peer is smc capable */
1940 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
1941 		smc_switch_to_fallback(new_smc, SMC_CLC_DECL_PEERNOSMC);
1942 		smc_listen_out_connected(new_smc);
1943 		return;
1944 	}
1945 
1946 	/* do inband token exchange -
1947 	 * wait for and receive SMC Proposal CLC message
1948 	 */
1949 	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
1950 	if (!buf) {
1951 		rc = SMC_CLC_DECL_MEM;
1952 		goto out_decl;
1953 	}
1954 	pclc = (struct smc_clc_msg_proposal *)buf;
1955 	rc = smc_clc_wait_msg(new_smc, pclc, sizeof(*buf),
1956 			      SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
1957 	if (rc)
1958 		goto out_decl;
1959 
1960 	if (pclc->hdr.version > SMC_V1)
1961 		proposal_version = SMC_V2;
1962 
1963 	/* IPSec connections opt out of SMC optimizations */
1964 	if (using_ipsec(new_smc)) {
1965 		rc = SMC_CLC_DECL_IPSEC;
1966 		goto out_decl;
1967 	}
1968 
1969 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1970 	if (!ini) {
1971 		rc = SMC_CLC_DECL_MEM;
1972 		goto out_decl;
1973 	}
1974 
1975 	/* initial version checking */
1976 	rc = smc_listen_v2_check(new_smc, pclc, ini);
1977 	if (rc)
1978 		goto out_decl;
1979 
1980 	mutex_lock(&smc_server_lgr_pending);
1981 	smc_close_init(new_smc);
1982 	smc_rx_init(new_smc);
1983 	smc_tx_init(new_smc);
1984 
1985 	/* determine ISM or RoCE device used for connection */
1986 	rc = smc_listen_find_device(new_smc, pclc, ini);
1987 	if (rc)
1988 		goto out_unlock;
1989 
1990 	/* send SMC Accept CLC message */
1991 	accept_version = ini->is_smcd ? ini->smcd_version : ini->smcr_version;
1992 	rc = smc_clc_send_accept(new_smc, ini->first_contact_local,
1993 				 accept_version, ini->negotiated_eid);
1994 	if (rc)
1995 		goto out_unlock;
1996 
1997 	/* SMC-D does not need this lock any more */
1998 	if (ini->is_smcd)
1999 		mutex_unlock(&smc_server_lgr_pending);
2000 
2001 	/* receive SMC Confirm CLC message */
2002 	memset(buf, 0, sizeof(*buf));
2003 	cclc = (struct smc_clc_msg_accept_confirm *)buf;
2004 	rc = smc_clc_wait_msg(new_smc, cclc, sizeof(*buf),
2005 			      SMC_CLC_CONFIRM, CLC_WAIT_TIME);
2006 	if (rc) {
2007 		if (!ini->is_smcd)
2008 			goto out_unlock;
2009 		goto out_decl;
2010 	}
2011 
2012 	/* finish worker */
2013 	if (!ini->is_smcd) {
2014 		rc = smc_listen_rdma_finish(new_smc, cclc,
2015 					    ini->first_contact_local, ini);
2016 		if (rc)
2017 			goto out_unlock;
2018 		mutex_unlock(&smc_server_lgr_pending);
2019 	}
2020 	smc_conn_save_peer_info(new_smc, cclc);
2021 	smc_listen_out_connected(new_smc);
2022 	SMC_STAT_SERV_SUCC_INC(sock_net(newclcsock->sk), ini);
2023 	goto out_free;
2024 
2025 out_unlock:
2026 	mutex_unlock(&smc_server_lgr_pending);
2027 out_decl:
2028 	smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0,
2029 			   proposal_version);
2030 out_free:
2031 	kfree(ini);
2032 	kfree(buf);
2033 }
2034 
2035 static void smc_tcp_listen_work(struct work_struct *work)
2036 {
2037 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
2038 					     tcp_listen_work);
2039 	struct sock *lsk = &lsmc->sk;
2040 	struct smc_sock *new_smc;
2041 	int rc = 0;
2042 
2043 	lock_sock(lsk);
2044 	while (lsk->sk_state == SMC_LISTEN) {
2045 		rc = smc_clcsock_accept(lsmc, &new_smc);
2046 		if (rc) /* clcsock accept queue empty or error */
2047 			goto out;
2048 		if (!new_smc)
2049 			continue;
2050 
2051 		new_smc->listen_smc = lsmc;
2052 		new_smc->use_fallback = lsmc->use_fallback;
2053 		new_smc->fallback_rsn = lsmc->fallback_rsn;
2054 		sock_hold(lsk); /* sock_put in smc_listen_work */
2055 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
2056 		smc_copy_sock_settings_to_smc(new_smc);
2057 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
2058 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
2059 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
2060 		if (!queue_work(smc_hs_wq, &new_smc->smc_listen_work))
2061 			sock_put(&new_smc->sk);
2062 	}
2063 
2064 out:
2065 	release_sock(lsk);
2066 	sock_put(&lsmc->sk); /* sock_hold in smc_clcsock_data_ready() */
2067 }
2068 
2069 static void smc_clcsock_data_ready(struct sock *listen_clcsock)
2070 {
2071 	struct smc_sock *lsmc;
2072 
2073 	lsmc = (struct smc_sock *)
2074 	       ((uintptr_t)listen_clcsock->sk_user_data & ~SK_USER_DATA_NOCOPY);
2075 	if (!lsmc)
2076 		return;
2077 	lsmc->clcsk_data_ready(listen_clcsock);
2078 	if (lsmc->sk.sk_state == SMC_LISTEN) {
2079 		sock_hold(&lsmc->sk); /* sock_put in smc_tcp_listen_work() */
2080 		if (!queue_work(smc_hs_wq, &lsmc->tcp_listen_work))
2081 			sock_put(&lsmc->sk);
2082 	}
2083 }
2084 
2085 static int smc_listen(struct socket *sock, int backlog)
2086 {
2087 	struct sock *sk = sock->sk;
2088 	struct smc_sock *smc;
2089 	int rc;
2090 
2091 	smc = smc_sk(sk);
2092 	lock_sock(sk);
2093 
2094 	rc = -EINVAL;
2095 	if ((sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) ||
2096 	    smc->connect_nonblock)
2097 		goto out;
2098 
2099 	rc = 0;
2100 	if (sk->sk_state == SMC_LISTEN) {
2101 		sk->sk_max_ack_backlog = backlog;
2102 		goto out;
2103 	}
2104 	/* some socket options are handled in core, so we could not apply
2105 	 * them to the clc socket -- copy smc socket options to clc socket
2106 	 */
2107 	smc_copy_sock_settings_to_clc(smc);
2108 	if (!smc->use_fallback)
2109 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
2110 
2111 	/* save original sk_data_ready function and establish
2112 	 * smc-specific sk_data_ready function
2113 	 */
2114 	smc->clcsk_data_ready = smc->clcsock->sk->sk_data_ready;
2115 	smc->clcsock->sk->sk_data_ready = smc_clcsock_data_ready;
2116 	smc->clcsock->sk->sk_user_data =
2117 		(void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
2118 	rc = kernel_listen(smc->clcsock, backlog);
2119 	if (rc)
2120 		goto out;
2121 	sk->sk_max_ack_backlog = backlog;
2122 	sk->sk_ack_backlog = 0;
2123 	sk->sk_state = SMC_LISTEN;
2124 
2125 out:
2126 	release_sock(sk);
2127 	return rc;
2128 }
2129 
2130 static int smc_accept(struct socket *sock, struct socket *new_sock,
2131 		      int flags, bool kern)
2132 {
2133 	struct sock *sk = sock->sk, *nsk;
2134 	DECLARE_WAITQUEUE(wait, current);
2135 	struct smc_sock *lsmc;
2136 	long timeo;
2137 	int rc = 0;
2138 
2139 	lsmc = smc_sk(sk);
2140 	sock_hold(sk); /* sock_put below */
2141 	lock_sock(sk);
2142 
2143 	if (lsmc->sk.sk_state != SMC_LISTEN) {
2144 		rc = -EINVAL;
2145 		release_sock(sk);
2146 		goto out;
2147 	}
2148 
2149 	/* Wait for an incoming connection */
2150 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
2151 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
2152 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
2153 		set_current_state(TASK_INTERRUPTIBLE);
2154 		if (!timeo) {
2155 			rc = -EAGAIN;
2156 			break;
2157 		}
2158 		release_sock(sk);
2159 		timeo = schedule_timeout(timeo);
2160 		/* wakeup by sk_data_ready in smc_listen_work() */
2161 		sched_annotate_sleep();
2162 		lock_sock(sk);
2163 		if (signal_pending(current)) {
2164 			rc = sock_intr_errno(timeo);
2165 			break;
2166 		}
2167 	}
2168 	set_current_state(TASK_RUNNING);
2169 	remove_wait_queue(sk_sleep(sk), &wait);
2170 
2171 	if (!rc)
2172 		rc = sock_error(nsk);
2173 	release_sock(sk);
2174 	if (rc)
2175 		goto out;
2176 
2177 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
2178 		/* wait till data arrives on the socket */
2179 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
2180 								MSEC_PER_SEC);
2181 		if (smc_sk(nsk)->use_fallback) {
2182 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
2183 
2184 			lock_sock(clcsk);
2185 			if (skb_queue_empty(&clcsk->sk_receive_queue))
2186 				sk_wait_data(clcsk, &timeo, NULL);
2187 			release_sock(clcsk);
2188 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
2189 			lock_sock(nsk);
2190 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
2191 			release_sock(nsk);
2192 		}
2193 	}
2194 
2195 out:
2196 	sock_put(sk); /* sock_hold above */
2197 	return rc;
2198 }
2199 
2200 static int smc_getname(struct socket *sock, struct sockaddr *addr,
2201 		       int peer)
2202 {
2203 	struct smc_sock *smc;
2204 
2205 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
2206 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
2207 		return -ENOTCONN;
2208 
2209 	smc = smc_sk(sock->sk);
2210 
2211 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
2212 }
2213 
2214 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2215 {
2216 	struct sock *sk = sock->sk;
2217 	struct smc_sock *smc;
2218 	int rc = -EPIPE;
2219 
2220 	smc = smc_sk(sk);
2221 	lock_sock(sk);
2222 	if ((sk->sk_state != SMC_ACTIVE) &&
2223 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2224 	    (sk->sk_state != SMC_INIT))
2225 		goto out;
2226 
2227 	if (msg->msg_flags & MSG_FASTOPEN) {
2228 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2229 			smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2230 		} else {
2231 			rc = -EINVAL;
2232 			goto out;
2233 		}
2234 	}
2235 
2236 	if (smc->use_fallback) {
2237 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
2238 	} else {
2239 		rc = smc_tx_sendmsg(smc, msg, len);
2240 		SMC_STAT_TX_PAYLOAD(smc, len, rc);
2241 	}
2242 out:
2243 	release_sock(sk);
2244 	return rc;
2245 }
2246 
2247 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2248 		       int flags)
2249 {
2250 	struct sock *sk = sock->sk;
2251 	struct smc_sock *smc;
2252 	int rc = -ENOTCONN;
2253 
2254 	smc = smc_sk(sk);
2255 	lock_sock(sk);
2256 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2257 		/* socket was connected before, no more data to read */
2258 		rc = 0;
2259 		goto out;
2260 	}
2261 	if ((sk->sk_state == SMC_INIT) ||
2262 	    (sk->sk_state == SMC_LISTEN) ||
2263 	    (sk->sk_state == SMC_CLOSED))
2264 		goto out;
2265 
2266 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2267 		rc = 0;
2268 		goto out;
2269 	}
2270 
2271 	if (smc->use_fallback) {
2272 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
2273 	} else {
2274 		msg->msg_namelen = 0;
2275 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
2276 		SMC_STAT_RX_PAYLOAD(smc, rc, rc);
2277 	}
2278 
2279 out:
2280 	release_sock(sk);
2281 	return rc;
2282 }
2283 
2284 static __poll_t smc_accept_poll(struct sock *parent)
2285 {
2286 	struct smc_sock *isk = smc_sk(parent);
2287 	__poll_t mask = 0;
2288 
2289 	spin_lock(&isk->accept_q_lock);
2290 	if (!list_empty(&isk->accept_q))
2291 		mask = EPOLLIN | EPOLLRDNORM;
2292 	spin_unlock(&isk->accept_q_lock);
2293 
2294 	return mask;
2295 }
2296 
2297 static __poll_t smc_poll(struct file *file, struct socket *sock,
2298 			     poll_table *wait)
2299 {
2300 	struct sock *sk = sock->sk;
2301 	struct smc_sock *smc;
2302 	__poll_t mask = 0;
2303 
2304 	if (!sk)
2305 		return EPOLLNVAL;
2306 
2307 	smc = smc_sk(sock->sk);
2308 	if (smc->use_fallback) {
2309 		/* delegate to CLC child sock */
2310 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
2311 		sk->sk_err = smc->clcsock->sk->sk_err;
2312 	} else {
2313 		if (sk->sk_state != SMC_CLOSED)
2314 			sock_poll_wait(file, sock, wait);
2315 		if (sk->sk_err)
2316 			mask |= EPOLLERR;
2317 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
2318 		    (sk->sk_state == SMC_CLOSED))
2319 			mask |= EPOLLHUP;
2320 		if (sk->sk_state == SMC_LISTEN) {
2321 			/* woken up by sk_data_ready in smc_listen_work() */
2322 			mask |= smc_accept_poll(sk);
2323 		} else if (smc->use_fallback) { /* as result of connect_work()*/
2324 			mask |= smc->clcsock->ops->poll(file, smc->clcsock,
2325 							   wait);
2326 			sk->sk_err = smc->clcsock->sk->sk_err;
2327 		} else {
2328 			if ((sk->sk_state != SMC_INIT &&
2329 			     atomic_read(&smc->conn.sndbuf_space)) ||
2330 			    sk->sk_shutdown & SEND_SHUTDOWN) {
2331 				mask |= EPOLLOUT | EPOLLWRNORM;
2332 			} else {
2333 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2334 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2335 			}
2336 			if (atomic_read(&smc->conn.bytes_to_rcv))
2337 				mask |= EPOLLIN | EPOLLRDNORM;
2338 			if (sk->sk_shutdown & RCV_SHUTDOWN)
2339 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
2340 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
2341 				mask |= EPOLLIN;
2342 			if (smc->conn.urg_state == SMC_URG_VALID)
2343 				mask |= EPOLLPRI;
2344 		}
2345 	}
2346 
2347 	return mask;
2348 }
2349 
2350 static int smc_shutdown(struct socket *sock, int how)
2351 {
2352 	struct sock *sk = sock->sk;
2353 	struct smc_sock *smc;
2354 	int rc = -EINVAL;
2355 	int rc1 = 0;
2356 
2357 	smc = smc_sk(sk);
2358 
2359 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
2360 		return rc;
2361 
2362 	lock_sock(sk);
2363 
2364 	rc = -ENOTCONN;
2365 	if ((sk->sk_state != SMC_ACTIVE) &&
2366 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
2367 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
2368 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2369 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
2370 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
2371 		goto out;
2372 	if (smc->use_fallback) {
2373 		rc = kernel_sock_shutdown(smc->clcsock, how);
2374 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
2375 		if (sk->sk_shutdown == SHUTDOWN_MASK)
2376 			sk->sk_state = SMC_CLOSED;
2377 		goto out;
2378 	}
2379 	switch (how) {
2380 	case SHUT_RDWR:		/* shutdown in both directions */
2381 		rc = smc_close_active(smc);
2382 		break;
2383 	case SHUT_WR:
2384 		rc = smc_close_shutdown_write(smc);
2385 		break;
2386 	case SHUT_RD:
2387 		rc = 0;
2388 		/* nothing more to do because peer is not involved */
2389 		break;
2390 	}
2391 	if (smc->clcsock)
2392 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
2393 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
2394 	sk->sk_shutdown |= how + 1;
2395 
2396 out:
2397 	release_sock(sk);
2398 	return rc ? rc : rc1;
2399 }
2400 
2401 static int smc_setsockopt(struct socket *sock, int level, int optname,
2402 			  sockptr_t optval, unsigned int optlen)
2403 {
2404 	struct sock *sk = sock->sk;
2405 	struct smc_sock *smc;
2406 	int val, rc;
2407 
2408 	if (level == SOL_TCP && optname == TCP_ULP)
2409 		return -EOPNOTSUPP;
2410 
2411 	smc = smc_sk(sk);
2412 
2413 	/* generic setsockopts reaching us here always apply to the
2414 	 * CLC socket
2415 	 */
2416 	if (unlikely(!smc->clcsock->ops->setsockopt))
2417 		rc = -EOPNOTSUPP;
2418 	else
2419 		rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
2420 						   optval, optlen);
2421 	if (smc->clcsock->sk->sk_err) {
2422 		sk->sk_err = smc->clcsock->sk->sk_err;
2423 		sk_error_report(sk);
2424 	}
2425 
2426 	if (optlen < sizeof(int))
2427 		return -EINVAL;
2428 	if (copy_from_sockptr(&val, optval, sizeof(int)))
2429 		return -EFAULT;
2430 
2431 	lock_sock(sk);
2432 	if (rc || smc->use_fallback)
2433 		goto out;
2434 	switch (optname) {
2435 	case TCP_FASTOPEN:
2436 	case TCP_FASTOPEN_CONNECT:
2437 	case TCP_FASTOPEN_KEY:
2438 	case TCP_FASTOPEN_NO_COOKIE:
2439 		/* option not supported by SMC */
2440 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2441 			smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2442 		} else {
2443 			rc = -EINVAL;
2444 		}
2445 		break;
2446 	case TCP_NODELAY:
2447 		if (sk->sk_state != SMC_INIT &&
2448 		    sk->sk_state != SMC_LISTEN &&
2449 		    sk->sk_state != SMC_CLOSED) {
2450 			if (val) {
2451 				SMC_STAT_INC(smc, ndly_cnt);
2452 				mod_delayed_work(smc->conn.lgr->tx_wq,
2453 						 &smc->conn.tx_work, 0);
2454 			}
2455 		}
2456 		break;
2457 	case TCP_CORK:
2458 		if (sk->sk_state != SMC_INIT &&
2459 		    sk->sk_state != SMC_LISTEN &&
2460 		    sk->sk_state != SMC_CLOSED) {
2461 			if (!val) {
2462 				SMC_STAT_INC(smc, cork_cnt);
2463 				mod_delayed_work(smc->conn.lgr->tx_wq,
2464 						 &smc->conn.tx_work, 0);
2465 			}
2466 		}
2467 		break;
2468 	case TCP_DEFER_ACCEPT:
2469 		smc->sockopt_defer_accept = val;
2470 		break;
2471 	default:
2472 		break;
2473 	}
2474 out:
2475 	release_sock(sk);
2476 
2477 	return rc;
2478 }
2479 
2480 static int smc_getsockopt(struct socket *sock, int level, int optname,
2481 			  char __user *optval, int __user *optlen)
2482 {
2483 	struct smc_sock *smc;
2484 
2485 	smc = smc_sk(sock->sk);
2486 	/* socket options apply to the CLC socket */
2487 	if (unlikely(!smc->clcsock->ops->getsockopt))
2488 		return -EOPNOTSUPP;
2489 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
2490 					     optval, optlen);
2491 }
2492 
2493 static int smc_ioctl(struct socket *sock, unsigned int cmd,
2494 		     unsigned long arg)
2495 {
2496 	union smc_host_cursor cons, urg;
2497 	struct smc_connection *conn;
2498 	struct smc_sock *smc;
2499 	int answ;
2500 
2501 	smc = smc_sk(sock->sk);
2502 	conn = &smc->conn;
2503 	lock_sock(&smc->sk);
2504 	if (smc->use_fallback) {
2505 		if (!smc->clcsock) {
2506 			release_sock(&smc->sk);
2507 			return -EBADF;
2508 		}
2509 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
2510 		release_sock(&smc->sk);
2511 		return answ;
2512 	}
2513 	switch (cmd) {
2514 	case SIOCINQ: /* same as FIONREAD */
2515 		if (smc->sk.sk_state == SMC_LISTEN) {
2516 			release_sock(&smc->sk);
2517 			return -EINVAL;
2518 		}
2519 		if (smc->sk.sk_state == SMC_INIT ||
2520 		    smc->sk.sk_state == SMC_CLOSED)
2521 			answ = 0;
2522 		else
2523 			answ = atomic_read(&smc->conn.bytes_to_rcv);
2524 		break;
2525 	case SIOCOUTQ:
2526 		/* output queue size (not send + not acked) */
2527 		if (smc->sk.sk_state == SMC_LISTEN) {
2528 			release_sock(&smc->sk);
2529 			return -EINVAL;
2530 		}
2531 		if (smc->sk.sk_state == SMC_INIT ||
2532 		    smc->sk.sk_state == SMC_CLOSED)
2533 			answ = 0;
2534 		else
2535 			answ = smc->conn.sndbuf_desc->len -
2536 					atomic_read(&smc->conn.sndbuf_space);
2537 		break;
2538 	case SIOCOUTQNSD:
2539 		/* output queue size (not send only) */
2540 		if (smc->sk.sk_state == SMC_LISTEN) {
2541 			release_sock(&smc->sk);
2542 			return -EINVAL;
2543 		}
2544 		if (smc->sk.sk_state == SMC_INIT ||
2545 		    smc->sk.sk_state == SMC_CLOSED)
2546 			answ = 0;
2547 		else
2548 			answ = smc_tx_prepared_sends(&smc->conn);
2549 		break;
2550 	case SIOCATMARK:
2551 		if (smc->sk.sk_state == SMC_LISTEN) {
2552 			release_sock(&smc->sk);
2553 			return -EINVAL;
2554 		}
2555 		if (smc->sk.sk_state == SMC_INIT ||
2556 		    smc->sk.sk_state == SMC_CLOSED) {
2557 			answ = 0;
2558 		} else {
2559 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
2560 			smc_curs_copy(&urg, &conn->urg_curs, conn);
2561 			answ = smc_curs_diff(conn->rmb_desc->len,
2562 					     &cons, &urg) == 1;
2563 		}
2564 		break;
2565 	default:
2566 		release_sock(&smc->sk);
2567 		return -ENOIOCTLCMD;
2568 	}
2569 	release_sock(&smc->sk);
2570 
2571 	return put_user(answ, (int __user *)arg);
2572 }
2573 
2574 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
2575 			    int offset, size_t size, int flags)
2576 {
2577 	struct sock *sk = sock->sk;
2578 	struct smc_sock *smc;
2579 	int rc = -EPIPE;
2580 
2581 	smc = smc_sk(sk);
2582 	lock_sock(sk);
2583 	if (sk->sk_state != SMC_ACTIVE) {
2584 		release_sock(sk);
2585 		goto out;
2586 	}
2587 	release_sock(sk);
2588 	if (smc->use_fallback) {
2589 		rc = kernel_sendpage(smc->clcsock, page, offset,
2590 				     size, flags);
2591 	} else {
2592 		SMC_STAT_INC(smc, sendpage_cnt);
2593 		rc = sock_no_sendpage(sock, page, offset, size, flags);
2594 	}
2595 
2596 out:
2597 	return rc;
2598 }
2599 
2600 /* Map the affected portions of the rmbe into an spd, note the number of bytes
2601  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
2602  * updates till whenever a respective page has been fully processed.
2603  * Note that subsequent recv() calls have to wait till all splice() processing
2604  * completed.
2605  */
2606 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
2607 			       struct pipe_inode_info *pipe, size_t len,
2608 			       unsigned int flags)
2609 {
2610 	struct sock *sk = sock->sk;
2611 	struct smc_sock *smc;
2612 	int rc = -ENOTCONN;
2613 
2614 	smc = smc_sk(sk);
2615 	lock_sock(sk);
2616 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2617 		/* socket was connected before, no more data to read */
2618 		rc = 0;
2619 		goto out;
2620 	}
2621 	if (sk->sk_state == SMC_INIT ||
2622 	    sk->sk_state == SMC_LISTEN ||
2623 	    sk->sk_state == SMC_CLOSED)
2624 		goto out;
2625 
2626 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2627 		rc = 0;
2628 		goto out;
2629 	}
2630 
2631 	if (smc->use_fallback) {
2632 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
2633 						    pipe, len, flags);
2634 	} else {
2635 		if (*ppos) {
2636 			rc = -ESPIPE;
2637 			goto out;
2638 		}
2639 		if (flags & SPLICE_F_NONBLOCK)
2640 			flags = MSG_DONTWAIT;
2641 		else
2642 			flags = 0;
2643 		SMC_STAT_INC(smc, splice_cnt);
2644 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
2645 	}
2646 out:
2647 	release_sock(sk);
2648 
2649 	return rc;
2650 }
2651 
2652 /* must look like tcp */
2653 static const struct proto_ops smc_sock_ops = {
2654 	.family		= PF_SMC,
2655 	.owner		= THIS_MODULE,
2656 	.release	= smc_release,
2657 	.bind		= smc_bind,
2658 	.connect	= smc_connect,
2659 	.socketpair	= sock_no_socketpair,
2660 	.accept		= smc_accept,
2661 	.getname	= smc_getname,
2662 	.poll		= smc_poll,
2663 	.ioctl		= smc_ioctl,
2664 	.listen		= smc_listen,
2665 	.shutdown	= smc_shutdown,
2666 	.setsockopt	= smc_setsockopt,
2667 	.getsockopt	= smc_getsockopt,
2668 	.sendmsg	= smc_sendmsg,
2669 	.recvmsg	= smc_recvmsg,
2670 	.mmap		= sock_no_mmap,
2671 	.sendpage	= smc_sendpage,
2672 	.splice_read	= smc_splice_read,
2673 };
2674 
2675 static int smc_create(struct net *net, struct socket *sock, int protocol,
2676 		      int kern)
2677 {
2678 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
2679 	struct smc_sock *smc;
2680 	struct sock *sk;
2681 	int rc;
2682 
2683 	rc = -ESOCKTNOSUPPORT;
2684 	if (sock->type != SOCK_STREAM)
2685 		goto out;
2686 
2687 	rc = -EPROTONOSUPPORT;
2688 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
2689 		goto out;
2690 
2691 	rc = -ENOBUFS;
2692 	sock->ops = &smc_sock_ops;
2693 	sk = smc_sock_alloc(net, sock, protocol);
2694 	if (!sk)
2695 		goto out;
2696 
2697 	/* create internal TCP socket for CLC handshake and fallback */
2698 	smc = smc_sk(sk);
2699 	smc->use_fallback = false; /* assume rdma capability first */
2700 	smc->fallback_rsn = 0;
2701 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
2702 			      &smc->clcsock);
2703 	if (rc) {
2704 		sk_common_release(sk);
2705 		goto out;
2706 	}
2707 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
2708 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
2709 
2710 out:
2711 	return rc;
2712 }
2713 
2714 static const struct net_proto_family smc_sock_family_ops = {
2715 	.family	= PF_SMC,
2716 	.owner	= THIS_MODULE,
2717 	.create	= smc_create,
2718 };
2719 
2720 unsigned int smc_net_id;
2721 
2722 static __net_init int smc_net_init(struct net *net)
2723 {
2724 	return smc_pnet_net_init(net);
2725 }
2726 
2727 static void __net_exit smc_net_exit(struct net *net)
2728 {
2729 	smc_pnet_net_exit(net);
2730 }
2731 
2732 static __net_init int smc_net_stat_init(struct net *net)
2733 {
2734 	return smc_stats_init(net);
2735 }
2736 
2737 static void __net_exit smc_net_stat_exit(struct net *net)
2738 {
2739 	smc_stats_exit(net);
2740 }
2741 
2742 static struct pernet_operations smc_net_ops = {
2743 	.init = smc_net_init,
2744 	.exit = smc_net_exit,
2745 	.id   = &smc_net_id,
2746 	.size = sizeof(struct smc_net),
2747 };
2748 
2749 static struct pernet_operations smc_net_stat_ops = {
2750 	.init = smc_net_stat_init,
2751 	.exit = smc_net_stat_exit,
2752 };
2753 
2754 static int __init smc_init(void)
2755 {
2756 	int rc;
2757 
2758 	rc = register_pernet_subsys(&smc_net_ops);
2759 	if (rc)
2760 		return rc;
2761 
2762 	rc = register_pernet_subsys(&smc_net_stat_ops);
2763 	if (rc)
2764 		return rc;
2765 
2766 	smc_ism_init();
2767 	smc_clc_init();
2768 
2769 	rc = smc_nl_init();
2770 	if (rc)
2771 		goto out_pernet_subsys;
2772 
2773 	rc = smc_pnet_init();
2774 	if (rc)
2775 		goto out_nl;
2776 
2777 	rc = -ENOMEM;
2778 	smc_hs_wq = alloc_workqueue("smc_hs_wq", 0, 0);
2779 	if (!smc_hs_wq)
2780 		goto out_pnet;
2781 
2782 	smc_close_wq = alloc_workqueue("smc_close_wq", 0, 0);
2783 	if (!smc_close_wq)
2784 		goto out_alloc_hs_wq;
2785 
2786 	rc = smc_core_init();
2787 	if (rc) {
2788 		pr_err("%s: smc_core_init fails with %d\n", __func__, rc);
2789 		goto out_alloc_wqs;
2790 	}
2791 
2792 	rc = smc_llc_init();
2793 	if (rc) {
2794 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
2795 		goto out_core;
2796 	}
2797 
2798 	rc = smc_cdc_init();
2799 	if (rc) {
2800 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
2801 		goto out_core;
2802 	}
2803 
2804 	rc = proto_register(&smc_proto, 1);
2805 	if (rc) {
2806 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
2807 		goto out_core;
2808 	}
2809 
2810 	rc = proto_register(&smc_proto6, 1);
2811 	if (rc) {
2812 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
2813 		goto out_proto;
2814 	}
2815 
2816 	rc = sock_register(&smc_sock_family_ops);
2817 	if (rc) {
2818 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
2819 		goto out_proto6;
2820 	}
2821 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
2822 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
2823 
2824 	rc = smc_ib_register_client();
2825 	if (rc) {
2826 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
2827 		goto out_sock;
2828 	}
2829 
2830 	static_branch_enable(&tcp_have_smc);
2831 	return 0;
2832 
2833 out_sock:
2834 	sock_unregister(PF_SMC);
2835 out_proto6:
2836 	proto_unregister(&smc_proto6);
2837 out_proto:
2838 	proto_unregister(&smc_proto);
2839 out_core:
2840 	smc_core_exit();
2841 out_alloc_wqs:
2842 	destroy_workqueue(smc_close_wq);
2843 out_alloc_hs_wq:
2844 	destroy_workqueue(smc_hs_wq);
2845 out_pnet:
2846 	smc_pnet_exit();
2847 out_nl:
2848 	smc_nl_exit();
2849 out_pernet_subsys:
2850 	unregister_pernet_subsys(&smc_net_ops);
2851 
2852 	return rc;
2853 }
2854 
2855 static void __exit smc_exit(void)
2856 {
2857 	static_branch_disable(&tcp_have_smc);
2858 	sock_unregister(PF_SMC);
2859 	smc_core_exit();
2860 	smc_ib_unregister_client();
2861 	destroy_workqueue(smc_close_wq);
2862 	destroy_workqueue(smc_hs_wq);
2863 	proto_unregister(&smc_proto6);
2864 	proto_unregister(&smc_proto);
2865 	smc_pnet_exit();
2866 	smc_nl_exit();
2867 	smc_clc_exit();
2868 	unregister_pernet_subsys(&smc_net_stat_ops);
2869 	unregister_pernet_subsys(&smc_net_ops);
2870 	rcu_barrier();
2871 }
2872 
2873 module_init(smc_init);
2874 module_exit(smc_exit);
2875 
2876 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
2877 MODULE_DESCRIPTION("smc socket address family");
2878 MODULE_LICENSE("GPL");
2879 MODULE_ALIAS_NETPROTO(PF_SMC);
2880