xref: /linux/net/smc/af_smc.c (revision 65aa371ea52a92dd10826a2ea74bd2c395ee90a8)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
4  *
5  *  AF_SMC protocol family socket handler keeping the AF_INET sock address type
6  *  applies to SOCK_STREAM sockets only
7  *  offers an alternative communication option for TCP-protocol sockets
8  *  applicable with RoCE-cards only
9  *
10  *  Initial restrictions:
11  *    - support for alternate links postponed
12  *
13  *  Copyright IBM Corp. 2016, 2018
14  *
15  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
16  *              based on prototype from Frank Blaschka
17  */
18 
19 #define KMSG_COMPONENT "smc"
20 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
21 
22 #include <linux/module.h>
23 #include <linux/socket.h>
24 #include <linux/workqueue.h>
25 #include <linux/in.h>
26 #include <linux/sched/signal.h>
27 #include <linux/if_vlan.h>
28 #include <linux/rcupdate_wait.h>
29 #include <linux/ctype.h>
30 
31 #include <net/sock.h>
32 #include <net/tcp.h>
33 #include <net/smc.h>
34 #include <asm/ioctls.h>
35 
36 #include <net/net_namespace.h>
37 #include <net/netns/generic.h>
38 #include "smc_netns.h"
39 
40 #include "smc.h"
41 #include "smc_clc.h"
42 #include "smc_llc.h"
43 #include "smc_cdc.h"
44 #include "smc_core.h"
45 #include "smc_ib.h"
46 #include "smc_ism.h"
47 #include "smc_pnet.h"
48 #include "smc_netlink.h"
49 #include "smc_tx.h"
50 #include "smc_rx.h"
51 #include "smc_close.h"
52 #include "smc_stats.h"
53 
54 static DEFINE_MUTEX(smc_server_lgr_pending);	/* serialize link group
55 						 * creation on server
56 						 */
57 static DEFINE_MUTEX(smc_client_lgr_pending);	/* serialize link group
58 						 * creation on client
59 						 */
60 
61 struct workqueue_struct	*smc_hs_wq;	/* wq for handshake work */
62 struct workqueue_struct	*smc_close_wq;	/* wq for close work */
63 
64 static void smc_tcp_listen_work(struct work_struct *);
65 static void smc_connect_work(struct work_struct *);
66 
67 static void smc_set_keepalive(struct sock *sk, int val)
68 {
69 	struct smc_sock *smc = smc_sk(sk);
70 
71 	smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
72 }
73 
74 static struct smc_hashinfo smc_v4_hashinfo = {
75 	.lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
76 };
77 
78 static struct smc_hashinfo smc_v6_hashinfo = {
79 	.lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
80 };
81 
82 int smc_hash_sk(struct sock *sk)
83 {
84 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
85 	struct hlist_head *head;
86 
87 	head = &h->ht;
88 
89 	write_lock_bh(&h->lock);
90 	sk_add_node(sk, head);
91 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
92 	write_unlock_bh(&h->lock);
93 
94 	return 0;
95 }
96 EXPORT_SYMBOL_GPL(smc_hash_sk);
97 
98 void smc_unhash_sk(struct sock *sk)
99 {
100 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
101 
102 	write_lock_bh(&h->lock);
103 	if (sk_del_node_init(sk))
104 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
105 	write_unlock_bh(&h->lock);
106 }
107 EXPORT_SYMBOL_GPL(smc_unhash_sk);
108 
109 struct proto smc_proto = {
110 	.name		= "SMC",
111 	.owner		= THIS_MODULE,
112 	.keepalive	= smc_set_keepalive,
113 	.hash		= smc_hash_sk,
114 	.unhash		= smc_unhash_sk,
115 	.obj_size	= sizeof(struct smc_sock),
116 	.h.smc_hash	= &smc_v4_hashinfo,
117 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
118 };
119 EXPORT_SYMBOL_GPL(smc_proto);
120 
121 struct proto smc_proto6 = {
122 	.name		= "SMC6",
123 	.owner		= THIS_MODULE,
124 	.keepalive	= smc_set_keepalive,
125 	.hash		= smc_hash_sk,
126 	.unhash		= smc_unhash_sk,
127 	.obj_size	= sizeof(struct smc_sock),
128 	.h.smc_hash	= &smc_v6_hashinfo,
129 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
130 };
131 EXPORT_SYMBOL_GPL(smc_proto6);
132 
133 static void smc_restore_fallback_changes(struct smc_sock *smc)
134 {
135 	if (smc->clcsock->file) { /* non-accepted sockets have no file yet */
136 		smc->clcsock->file->private_data = smc->sk.sk_socket;
137 		smc->clcsock->file = NULL;
138 	}
139 }
140 
141 static int __smc_release(struct smc_sock *smc)
142 {
143 	struct sock *sk = &smc->sk;
144 	int rc = 0;
145 
146 	if (!smc->use_fallback) {
147 		rc = smc_close_active(smc);
148 		sock_set_flag(sk, SOCK_DEAD);
149 		sk->sk_shutdown |= SHUTDOWN_MASK;
150 	} else {
151 		if (sk->sk_state != SMC_LISTEN && sk->sk_state != SMC_INIT)
152 			sock_put(sk); /* passive closing */
153 		if (sk->sk_state == SMC_LISTEN) {
154 			/* wake up clcsock accept */
155 			rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
156 		}
157 		sk->sk_state = SMC_CLOSED;
158 		sk->sk_state_change(sk);
159 		smc_restore_fallback_changes(smc);
160 	}
161 
162 	sk->sk_prot->unhash(sk);
163 
164 	if (sk->sk_state == SMC_CLOSED) {
165 		if (smc->clcsock) {
166 			release_sock(sk);
167 			smc_clcsock_release(smc);
168 			lock_sock(sk);
169 		}
170 		if (!smc->use_fallback)
171 			smc_conn_free(&smc->conn);
172 	}
173 
174 	return rc;
175 }
176 
177 static int smc_release(struct socket *sock)
178 {
179 	struct sock *sk = sock->sk;
180 	struct smc_sock *smc;
181 	int rc = 0;
182 
183 	if (!sk)
184 		goto out;
185 
186 	sock_hold(sk); /* sock_put below */
187 	smc = smc_sk(sk);
188 
189 	/* cleanup for a dangling non-blocking connect */
190 	if (smc->connect_nonblock && sk->sk_state == SMC_INIT)
191 		tcp_abort(smc->clcsock->sk, ECONNABORTED);
192 	flush_work(&smc->connect_work);
193 
194 	if (sk->sk_state == SMC_LISTEN)
195 		/* smc_close_non_accepted() is called and acquires
196 		 * sock lock for child sockets again
197 		 */
198 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
199 	else
200 		lock_sock(sk);
201 
202 	rc = __smc_release(smc);
203 
204 	/* detach socket */
205 	sock_orphan(sk);
206 	sock->sk = NULL;
207 	release_sock(sk);
208 
209 	sock_put(sk); /* sock_hold above */
210 	sock_put(sk); /* final sock_put */
211 out:
212 	return rc;
213 }
214 
215 static void smc_destruct(struct sock *sk)
216 {
217 	if (sk->sk_state != SMC_CLOSED)
218 		return;
219 	if (!sock_flag(sk, SOCK_DEAD))
220 		return;
221 
222 	sk_refcnt_debug_dec(sk);
223 }
224 
225 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
226 				   int protocol)
227 {
228 	struct smc_sock *smc;
229 	struct proto *prot;
230 	struct sock *sk;
231 
232 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
233 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
234 	if (!sk)
235 		return NULL;
236 
237 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
238 	sk->sk_state = SMC_INIT;
239 	sk->sk_destruct = smc_destruct;
240 	sk->sk_protocol = protocol;
241 	smc = smc_sk(sk);
242 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
243 	INIT_WORK(&smc->connect_work, smc_connect_work);
244 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
245 	INIT_LIST_HEAD(&smc->accept_q);
246 	spin_lock_init(&smc->accept_q_lock);
247 	spin_lock_init(&smc->conn.send_lock);
248 	sk->sk_prot->hash(sk);
249 	sk_refcnt_debug_inc(sk);
250 	mutex_init(&smc->clcsock_release_lock);
251 
252 	return sk;
253 }
254 
255 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
256 		    int addr_len)
257 {
258 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
259 	struct sock *sk = sock->sk;
260 	struct smc_sock *smc;
261 	int rc;
262 
263 	smc = smc_sk(sk);
264 
265 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
266 	rc = -EINVAL;
267 	if (addr_len < sizeof(struct sockaddr_in))
268 		goto out;
269 
270 	rc = -EAFNOSUPPORT;
271 	if (addr->sin_family != AF_INET &&
272 	    addr->sin_family != AF_INET6 &&
273 	    addr->sin_family != AF_UNSPEC)
274 		goto out;
275 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
276 	if (addr->sin_family == AF_UNSPEC &&
277 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
278 		goto out;
279 
280 	lock_sock(sk);
281 
282 	/* Check if socket is already active */
283 	rc = -EINVAL;
284 	if (sk->sk_state != SMC_INIT || smc->connect_nonblock)
285 		goto out_rel;
286 
287 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
288 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
289 
290 out_rel:
291 	release_sock(sk);
292 out:
293 	return rc;
294 }
295 
296 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
297 				   unsigned long mask)
298 {
299 	/* options we don't get control via setsockopt for */
300 	nsk->sk_type = osk->sk_type;
301 	nsk->sk_sndbuf = osk->sk_sndbuf;
302 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
303 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
304 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
305 	nsk->sk_mark = osk->sk_mark;
306 	nsk->sk_priority = osk->sk_priority;
307 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
308 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
309 	nsk->sk_err = osk->sk_err;
310 
311 	nsk->sk_flags &= ~mask;
312 	nsk->sk_flags |= osk->sk_flags & mask;
313 }
314 
315 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
316 			     (1UL << SOCK_KEEPOPEN) | \
317 			     (1UL << SOCK_LINGER) | \
318 			     (1UL << SOCK_BROADCAST) | \
319 			     (1UL << SOCK_TIMESTAMP) | \
320 			     (1UL << SOCK_DBG) | \
321 			     (1UL << SOCK_RCVTSTAMP) | \
322 			     (1UL << SOCK_RCVTSTAMPNS) | \
323 			     (1UL << SOCK_LOCALROUTE) | \
324 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
325 			     (1UL << SOCK_RXQ_OVFL) | \
326 			     (1UL << SOCK_WIFI_STATUS) | \
327 			     (1UL << SOCK_NOFCS) | \
328 			     (1UL << SOCK_FILTER_LOCKED) | \
329 			     (1UL << SOCK_TSTAMP_NEW))
330 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
331  * clc socket (since smc is not called for these options from net/core)
332  */
333 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
334 {
335 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
336 }
337 
338 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
339 			     (1UL << SOCK_KEEPOPEN) | \
340 			     (1UL << SOCK_LINGER) | \
341 			     (1UL << SOCK_DBG))
342 /* copy only settings and flags relevant for smc from clc to smc socket */
343 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
344 {
345 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
346 }
347 
348 /* register the new rmb on all links */
349 static int smcr_lgr_reg_rmbs(struct smc_link *link,
350 			     struct smc_buf_desc *rmb_desc)
351 {
352 	struct smc_link_group *lgr = link->lgr;
353 	int i, rc = 0;
354 
355 	rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
356 	if (rc)
357 		return rc;
358 	/* protect against parallel smc_llc_cli_rkey_exchange() and
359 	 * parallel smcr_link_reg_rmb()
360 	 */
361 	mutex_lock(&lgr->llc_conf_mutex);
362 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
363 		if (!smc_link_active(&lgr->lnk[i]))
364 			continue;
365 		rc = smcr_link_reg_rmb(&lgr->lnk[i], rmb_desc);
366 		if (rc)
367 			goto out;
368 	}
369 
370 	/* exchange confirm_rkey msg with peer */
371 	rc = smc_llc_do_confirm_rkey(link, rmb_desc);
372 	if (rc) {
373 		rc = -EFAULT;
374 		goto out;
375 	}
376 	rmb_desc->is_conf_rkey = true;
377 out:
378 	mutex_unlock(&lgr->llc_conf_mutex);
379 	smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
380 	return rc;
381 }
382 
383 static int smcr_clnt_conf_first_link(struct smc_sock *smc)
384 {
385 	struct smc_link *link = smc->conn.lnk;
386 	struct smc_llc_qentry *qentry;
387 	int rc;
388 
389 	/* receive CONFIRM LINK request from server over RoCE fabric */
390 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
391 			      SMC_LLC_CONFIRM_LINK);
392 	if (!qentry) {
393 		struct smc_clc_msg_decline dclc;
394 
395 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
396 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
397 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
398 	}
399 	smc_llc_save_peer_uid(qentry);
400 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_REQ);
401 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
402 	if (rc)
403 		return SMC_CLC_DECL_RMBE_EC;
404 
405 	rc = smc_ib_modify_qp_rts(link);
406 	if (rc)
407 		return SMC_CLC_DECL_ERR_RDYLNK;
408 
409 	smc_wr_remember_qp_attr(link);
410 
411 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc))
412 		return SMC_CLC_DECL_ERR_REGRMB;
413 
414 	/* confirm_rkey is implicit on 1st contact */
415 	smc->conn.rmb_desc->is_conf_rkey = true;
416 
417 	/* send CONFIRM LINK response over RoCE fabric */
418 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
419 	if (rc < 0)
420 		return SMC_CLC_DECL_TIMEOUT_CL;
421 
422 	smc_llc_link_active(link);
423 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
424 
425 	/* optional 2nd link, receive ADD LINK request from server */
426 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
427 			      SMC_LLC_ADD_LINK);
428 	if (!qentry) {
429 		struct smc_clc_msg_decline dclc;
430 
431 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
432 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
433 		if (rc == -EAGAIN)
434 			rc = 0; /* no DECLINE received, go with one link */
435 		return rc;
436 	}
437 	smc_llc_flow_qentry_clr(&link->lgr->llc_flow_lcl);
438 	smc_llc_cli_add_link(link, qentry);
439 	return 0;
440 }
441 
442 static bool smc_isascii(char *hostname)
443 {
444 	int i;
445 
446 	for (i = 0; i < SMC_MAX_HOSTNAME_LEN; i++)
447 		if (!isascii(hostname[i]))
448 			return false;
449 	return true;
450 }
451 
452 static void smc_conn_save_peer_info_fce(struct smc_sock *smc,
453 					struct smc_clc_msg_accept_confirm *clc)
454 {
455 	struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
456 		(struct smc_clc_msg_accept_confirm_v2 *)clc;
457 	struct smc_clc_first_contact_ext *fce;
458 	int clc_v2_len;
459 
460 	if (clc->hdr.version == SMC_V1 ||
461 	    !(clc->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
462 		return;
463 
464 	if (smc->conn.lgr->is_smcd) {
465 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->d1.eid,
466 		       SMC_MAX_EID_LEN);
467 		clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
468 					 d1);
469 	} else {
470 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->r1.eid,
471 		       SMC_MAX_EID_LEN);
472 		clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
473 					 r1);
474 	}
475 	fce = (struct smc_clc_first_contact_ext *)(((u8 *)clc_v2) + clc_v2_len);
476 	smc->conn.lgr->peer_os = fce->os_type;
477 	smc->conn.lgr->peer_smc_release = fce->release;
478 	if (smc_isascii(fce->hostname))
479 		memcpy(smc->conn.lgr->peer_hostname, fce->hostname,
480 		       SMC_MAX_HOSTNAME_LEN);
481 }
482 
483 static void smcr_conn_save_peer_info(struct smc_sock *smc,
484 				     struct smc_clc_msg_accept_confirm *clc)
485 {
486 	int bufsize = smc_uncompress_bufsize(clc->r0.rmbe_size);
487 
488 	smc->conn.peer_rmbe_idx = clc->r0.rmbe_idx;
489 	smc->conn.local_tx_ctrl.token = ntohl(clc->r0.rmbe_alert_token);
490 	smc->conn.peer_rmbe_size = bufsize;
491 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
492 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
493 }
494 
495 static void smcd_conn_save_peer_info(struct smc_sock *smc,
496 				     struct smc_clc_msg_accept_confirm *clc)
497 {
498 	int bufsize = smc_uncompress_bufsize(clc->d0.dmbe_size);
499 
500 	smc->conn.peer_rmbe_idx = clc->d0.dmbe_idx;
501 	smc->conn.peer_token = clc->d0.token;
502 	/* msg header takes up space in the buffer */
503 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
504 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
505 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
506 }
507 
508 static void smc_conn_save_peer_info(struct smc_sock *smc,
509 				    struct smc_clc_msg_accept_confirm *clc)
510 {
511 	if (smc->conn.lgr->is_smcd)
512 		smcd_conn_save_peer_info(smc, clc);
513 	else
514 		smcr_conn_save_peer_info(smc, clc);
515 	smc_conn_save_peer_info_fce(smc, clc);
516 }
517 
518 static void smc_link_save_peer_info(struct smc_link *link,
519 				    struct smc_clc_msg_accept_confirm *clc,
520 				    struct smc_init_info *ini)
521 {
522 	link->peer_qpn = ntoh24(clc->r0.qpn);
523 	memcpy(link->peer_gid, ini->peer_gid, SMC_GID_SIZE);
524 	memcpy(link->peer_mac, ini->peer_mac, sizeof(link->peer_mac));
525 	link->peer_psn = ntoh24(clc->r0.psn);
526 	link->peer_mtu = clc->r0.qp_mtu;
527 }
528 
529 static void smc_stat_inc_fback_rsn_cnt(struct smc_sock *smc,
530 				       struct smc_stats_fback *fback_arr)
531 {
532 	int cnt;
533 
534 	for (cnt = 0; cnt < SMC_MAX_FBACK_RSN_CNT; cnt++) {
535 		if (fback_arr[cnt].fback_code == smc->fallback_rsn) {
536 			fback_arr[cnt].count++;
537 			break;
538 		}
539 		if (!fback_arr[cnt].fback_code) {
540 			fback_arr[cnt].fback_code = smc->fallback_rsn;
541 			fback_arr[cnt].count++;
542 			break;
543 		}
544 	}
545 }
546 
547 static void smc_stat_fallback(struct smc_sock *smc)
548 {
549 	struct net *net = sock_net(&smc->sk);
550 
551 	mutex_lock(&net->smc.mutex_fback_rsn);
552 	if (smc->listen_smc) {
553 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->srv);
554 		net->smc.fback_rsn->srv_fback_cnt++;
555 	} else {
556 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->clnt);
557 		net->smc.fback_rsn->clnt_fback_cnt++;
558 	}
559 	mutex_unlock(&net->smc.mutex_fback_rsn);
560 }
561 
562 static void smc_switch_to_fallback(struct smc_sock *smc, int reason_code)
563 {
564 	smc->use_fallback = true;
565 	smc->fallback_rsn = reason_code;
566 	smc_stat_fallback(smc);
567 	if (smc->sk.sk_socket && smc->sk.sk_socket->file) {
568 		smc->clcsock->file = smc->sk.sk_socket->file;
569 		smc->clcsock->file->private_data = smc->clcsock;
570 		smc->clcsock->wq.fasync_list =
571 			smc->sk.sk_socket->wq.fasync_list;
572 	}
573 }
574 
575 /* fall back during connect */
576 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
577 {
578 	smc_switch_to_fallback(smc, reason_code);
579 	smc_copy_sock_settings_to_clc(smc);
580 	smc->connect_nonblock = 0;
581 	if (smc->sk.sk_state == SMC_INIT)
582 		smc->sk.sk_state = SMC_ACTIVE;
583 	return 0;
584 }
585 
586 /* decline and fall back during connect */
587 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code,
588 					u8 version)
589 {
590 	struct net *net = sock_net(&smc->sk);
591 	int rc;
592 
593 	if (reason_code < 0) { /* error, fallback is not possible */
594 		this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
595 		if (smc->sk.sk_state == SMC_INIT)
596 			sock_put(&smc->sk); /* passive closing */
597 		return reason_code;
598 	}
599 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
600 		rc = smc_clc_send_decline(smc, reason_code, version);
601 		if (rc < 0) {
602 			this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
603 			if (smc->sk.sk_state == SMC_INIT)
604 				sock_put(&smc->sk); /* passive closing */
605 			return rc;
606 		}
607 	}
608 	return smc_connect_fallback(smc, reason_code);
609 }
610 
611 static void smc_conn_abort(struct smc_sock *smc, int local_first)
612 {
613 	if (local_first)
614 		smc_lgr_cleanup_early(&smc->conn);
615 	else
616 		smc_conn_free(&smc->conn);
617 }
618 
619 /* check if there is a rdma device available for this connection. */
620 /* called for connect and listen */
621 static int smc_find_rdma_device(struct smc_sock *smc, struct smc_init_info *ini)
622 {
623 	/* PNET table look up: search active ib_device and port
624 	 * within same PNETID that also contains the ethernet device
625 	 * used for the internal TCP socket
626 	 */
627 	smc_pnet_find_roce_resource(smc->clcsock->sk, ini);
628 	if (!ini->check_smcrv2 && !ini->ib_dev)
629 		return SMC_CLC_DECL_NOSMCRDEV;
630 	if (ini->check_smcrv2 && !ini->smcrv2.ib_dev_v2)
631 		return SMC_CLC_DECL_NOSMCRDEV;
632 	return 0;
633 }
634 
635 /* check if there is an ISM device available for this connection. */
636 /* called for connect and listen */
637 static int smc_find_ism_device(struct smc_sock *smc, struct smc_init_info *ini)
638 {
639 	/* Find ISM device with same PNETID as connecting interface  */
640 	smc_pnet_find_ism_resource(smc->clcsock->sk, ini);
641 	if (!ini->ism_dev[0])
642 		return SMC_CLC_DECL_NOSMCDDEV;
643 	else
644 		ini->ism_chid[0] = smc_ism_get_chid(ini->ism_dev[0]);
645 	return 0;
646 }
647 
648 /* is chid unique for the ism devices that are already determined? */
649 static bool smc_find_ism_v2_is_unique_chid(u16 chid, struct smc_init_info *ini,
650 					   int cnt)
651 {
652 	int i = (!ini->ism_dev[0]) ? 1 : 0;
653 
654 	for (; i < cnt; i++)
655 		if (ini->ism_chid[i] == chid)
656 			return false;
657 	return true;
658 }
659 
660 /* determine possible V2 ISM devices (either without PNETID or with PNETID plus
661  * PNETID matching net_device)
662  */
663 static int smc_find_ism_v2_device_clnt(struct smc_sock *smc,
664 				       struct smc_init_info *ini)
665 {
666 	int rc = SMC_CLC_DECL_NOSMCDDEV;
667 	struct smcd_dev *smcd;
668 	int i = 1;
669 	u16 chid;
670 
671 	if (smcd_indicated(ini->smc_type_v1))
672 		rc = 0;		/* already initialized for V1 */
673 	mutex_lock(&smcd_dev_list.mutex);
674 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
675 		if (smcd->going_away || smcd == ini->ism_dev[0])
676 			continue;
677 		chid = smc_ism_get_chid(smcd);
678 		if (!smc_find_ism_v2_is_unique_chid(chid, ini, i))
679 			continue;
680 		if (!smc_pnet_is_pnetid_set(smcd->pnetid) ||
681 		    smc_pnet_is_ndev_pnetid(sock_net(&smc->sk), smcd->pnetid)) {
682 			ini->ism_dev[i] = smcd;
683 			ini->ism_chid[i] = chid;
684 			ini->is_smcd = true;
685 			rc = 0;
686 			i++;
687 			if (i > SMC_MAX_ISM_DEVS)
688 				break;
689 		}
690 	}
691 	mutex_unlock(&smcd_dev_list.mutex);
692 	ini->ism_offered_cnt = i - 1;
693 	if (!ini->ism_dev[0] && !ini->ism_dev[1])
694 		ini->smcd_version = 0;
695 
696 	return rc;
697 }
698 
699 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
700 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
701 				      struct smc_init_info *ini)
702 {
703 	if (ini->vlan_id && smc_ism_get_vlan(ini->ism_dev[0], ini->vlan_id))
704 		return SMC_CLC_DECL_ISMVLANERR;
705 	return 0;
706 }
707 
708 static int smc_find_proposal_devices(struct smc_sock *smc,
709 				     struct smc_init_info *ini)
710 {
711 	int rc = 0;
712 
713 	/* check if there is an ism device available */
714 	if (!(ini->smcd_version & SMC_V1) ||
715 	    smc_find_ism_device(smc, ini) ||
716 	    smc_connect_ism_vlan_setup(smc, ini))
717 		ini->smcd_version &= ~SMC_V1;
718 	/* else ISM V1 is supported for this connection */
719 
720 	/* check if there is an rdma device available */
721 	if (!(ini->smcr_version & SMC_V1) ||
722 	    smc_find_rdma_device(smc, ini))
723 		ini->smcr_version &= ~SMC_V1;
724 	/* else RDMA is supported for this connection */
725 
726 	ini->smc_type_v1 = smc_indicated_type(ini->smcd_version & SMC_V1,
727 					      ini->smcr_version & SMC_V1);
728 
729 	/* check if there is an ism v2 device available */
730 	if (!(ini->smcd_version & SMC_V2) ||
731 	    !smc_ism_is_v2_capable() ||
732 	    smc_find_ism_v2_device_clnt(smc, ini))
733 		ini->smcd_version &= ~SMC_V2;
734 
735 	/* check if there is an rdma v2 device available */
736 	ini->check_smcrv2 = true;
737 	ini->smcrv2.saddr = smc->clcsock->sk->sk_rcv_saddr;
738 	if (!(ini->smcr_version & SMC_V2) ||
739 	    smc->clcsock->sk->sk_family != AF_INET ||
740 	    !smc_clc_ueid_count() ||
741 	    smc_find_rdma_device(smc, ini))
742 		ini->smcr_version &= ~SMC_V2;
743 	ini->check_smcrv2 = false;
744 
745 	ini->smc_type_v2 = smc_indicated_type(ini->smcd_version & SMC_V2,
746 					      ini->smcr_version & SMC_V2);
747 
748 	/* if neither ISM nor RDMA are supported, fallback */
749 	if (ini->smc_type_v1 == SMC_TYPE_N && ini->smc_type_v2 == SMC_TYPE_N)
750 		rc = SMC_CLC_DECL_NOSMCDEV;
751 
752 	return rc;
753 }
754 
755 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
756  * used, the VLAN ID will be registered again during the connection setup.
757  */
758 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc,
759 					struct smc_init_info *ini)
760 {
761 	if (!smcd_indicated(ini->smc_type_v1))
762 		return 0;
763 	if (ini->vlan_id && smc_ism_put_vlan(ini->ism_dev[0], ini->vlan_id))
764 		return SMC_CLC_DECL_CNFERR;
765 	return 0;
766 }
767 
768 #define SMC_CLC_MAX_ACCEPT_LEN \
769 	(sizeof(struct smc_clc_msg_accept_confirm_v2) + \
770 	 sizeof(struct smc_clc_first_contact_ext) + \
771 	 sizeof(struct smc_clc_msg_trail))
772 
773 /* CLC handshake during connect */
774 static int smc_connect_clc(struct smc_sock *smc,
775 			   struct smc_clc_msg_accept_confirm_v2 *aclc2,
776 			   struct smc_init_info *ini)
777 {
778 	int rc = 0;
779 
780 	/* do inband token exchange */
781 	rc = smc_clc_send_proposal(smc, ini);
782 	if (rc)
783 		return rc;
784 	/* receive SMC Accept CLC message */
785 	return smc_clc_wait_msg(smc, aclc2, SMC_CLC_MAX_ACCEPT_LEN,
786 				SMC_CLC_ACCEPT, CLC_WAIT_TIME);
787 }
788 
789 void smc_fill_gid_list(struct smc_link_group *lgr,
790 		       struct smc_gidlist *gidlist,
791 		       struct smc_ib_device *known_dev, u8 *known_gid)
792 {
793 	struct smc_init_info *alt_ini = NULL;
794 
795 	memset(gidlist, 0, sizeof(*gidlist));
796 	memcpy(gidlist->list[gidlist->len++], known_gid, SMC_GID_SIZE);
797 
798 	alt_ini = kzalloc(sizeof(*alt_ini), GFP_KERNEL);
799 	if (!alt_ini)
800 		goto out;
801 
802 	alt_ini->vlan_id = lgr->vlan_id;
803 	alt_ini->check_smcrv2 = true;
804 	alt_ini->smcrv2.saddr = lgr->saddr;
805 	smc_pnet_find_alt_roce(lgr, alt_ini, known_dev);
806 
807 	if (!alt_ini->smcrv2.ib_dev_v2)
808 		goto out;
809 
810 	memcpy(gidlist->list[gidlist->len++], alt_ini->smcrv2.ib_gid_v2,
811 	       SMC_GID_SIZE);
812 
813 out:
814 	kfree(alt_ini);
815 }
816 
817 static int smc_connect_rdma_v2_prepare(struct smc_sock *smc,
818 				       struct smc_clc_msg_accept_confirm *aclc,
819 				       struct smc_init_info *ini)
820 {
821 	struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
822 		(struct smc_clc_msg_accept_confirm_v2 *)aclc;
823 	struct smc_clc_first_contact_ext *fce =
824 		(struct smc_clc_first_contact_ext *)
825 			(((u8 *)clc_v2) + sizeof(*clc_v2));
826 
827 	if (!ini->first_contact_peer || aclc->hdr.version == SMC_V1)
828 		return 0;
829 
830 	if (fce->v2_direct) {
831 		memcpy(ini->smcrv2.nexthop_mac, &aclc->r0.lcl.mac, ETH_ALEN);
832 		ini->smcrv2.uses_gateway = false;
833 	} else {
834 		if (smc_ib_find_route(smc->clcsock->sk->sk_rcv_saddr,
835 				      smc_ib_gid_to_ipv4(aclc->r0.lcl.gid),
836 				      ini->smcrv2.nexthop_mac,
837 				      &ini->smcrv2.uses_gateway))
838 			return SMC_CLC_DECL_NOROUTE;
839 		if (!ini->smcrv2.uses_gateway) {
840 			/* mismatch: peer claims indirect, but its direct */
841 			return SMC_CLC_DECL_NOINDIRECT;
842 		}
843 	}
844 	return 0;
845 }
846 
847 /* setup for RDMA connection of client */
848 static int smc_connect_rdma(struct smc_sock *smc,
849 			    struct smc_clc_msg_accept_confirm *aclc,
850 			    struct smc_init_info *ini)
851 {
852 	int i, reason_code = 0;
853 	struct smc_link *link;
854 	u8 *eid = NULL;
855 
856 	ini->is_smcd = false;
857 	ini->ib_clcqpn = ntoh24(aclc->r0.qpn);
858 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
859 	memcpy(ini->peer_systemid, aclc->r0.lcl.id_for_peer, SMC_SYSTEMID_LEN);
860 	memcpy(ini->peer_gid, aclc->r0.lcl.gid, SMC_GID_SIZE);
861 	memcpy(ini->peer_mac, aclc->r0.lcl.mac, ETH_ALEN);
862 
863 	reason_code = smc_connect_rdma_v2_prepare(smc, aclc, ini);
864 	if (reason_code)
865 		return reason_code;
866 
867 	mutex_lock(&smc_client_lgr_pending);
868 	reason_code = smc_conn_create(smc, ini);
869 	if (reason_code) {
870 		mutex_unlock(&smc_client_lgr_pending);
871 		return reason_code;
872 	}
873 
874 	smc_conn_save_peer_info(smc, aclc);
875 
876 	if (ini->first_contact_local) {
877 		link = smc->conn.lnk;
878 	} else {
879 		/* set link that was assigned by server */
880 		link = NULL;
881 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
882 			struct smc_link *l = &smc->conn.lgr->lnk[i];
883 
884 			if (l->peer_qpn == ntoh24(aclc->r0.qpn) &&
885 			    !memcmp(l->peer_gid, &aclc->r0.lcl.gid,
886 				    SMC_GID_SIZE) &&
887 			    (aclc->hdr.version > SMC_V1 ||
888 			     !memcmp(l->peer_mac, &aclc->r0.lcl.mac,
889 				     sizeof(l->peer_mac)))) {
890 				link = l;
891 				break;
892 			}
893 		}
894 		if (!link) {
895 			reason_code = SMC_CLC_DECL_NOSRVLINK;
896 			goto connect_abort;
897 		}
898 		smc_switch_link_and_count(&smc->conn, link);
899 	}
900 
901 	/* create send buffer and rmb */
902 	if (smc_buf_create(smc, false)) {
903 		reason_code = SMC_CLC_DECL_MEM;
904 		goto connect_abort;
905 	}
906 
907 	if (ini->first_contact_local)
908 		smc_link_save_peer_info(link, aclc, ini);
909 
910 	if (smc_rmb_rtoken_handling(&smc->conn, link, aclc)) {
911 		reason_code = SMC_CLC_DECL_ERR_RTOK;
912 		goto connect_abort;
913 	}
914 
915 	smc_close_init(smc);
916 	smc_rx_init(smc);
917 
918 	if (ini->first_contact_local) {
919 		if (smc_ib_ready_link(link)) {
920 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
921 			goto connect_abort;
922 		}
923 	} else {
924 		if (smcr_lgr_reg_rmbs(link, smc->conn.rmb_desc)) {
925 			reason_code = SMC_CLC_DECL_ERR_REGRMB;
926 			goto connect_abort;
927 		}
928 	}
929 	smc_rmb_sync_sg_for_device(&smc->conn);
930 
931 	if (aclc->hdr.version > SMC_V1) {
932 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
933 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
934 
935 		eid = clc_v2->r1.eid;
936 		if (ini->first_contact_local)
937 			smc_fill_gid_list(link->lgr, &ini->smcrv2.gidlist,
938 					  link->smcibdev, link->gid);
939 	}
940 
941 	reason_code = smc_clc_send_confirm(smc, ini->first_contact_local,
942 					   aclc->hdr.version, eid, ini);
943 	if (reason_code)
944 		goto connect_abort;
945 
946 	smc_tx_init(smc);
947 
948 	if (ini->first_contact_local) {
949 		/* QP confirmation over RoCE fabric */
950 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
951 		reason_code = smcr_clnt_conf_first_link(smc);
952 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
953 		if (reason_code)
954 			goto connect_abort;
955 	}
956 	mutex_unlock(&smc_client_lgr_pending);
957 
958 	smc_copy_sock_settings_to_clc(smc);
959 	smc->connect_nonblock = 0;
960 	if (smc->sk.sk_state == SMC_INIT)
961 		smc->sk.sk_state = SMC_ACTIVE;
962 
963 	return 0;
964 connect_abort:
965 	smc_conn_abort(smc, ini->first_contact_local);
966 	mutex_unlock(&smc_client_lgr_pending);
967 	smc->connect_nonblock = 0;
968 
969 	return reason_code;
970 }
971 
972 /* The server has chosen one of the proposed ISM devices for the communication.
973  * Determine from the CHID of the received CLC ACCEPT the ISM device chosen.
974  */
975 static int
976 smc_v2_determine_accepted_chid(struct smc_clc_msg_accept_confirm_v2 *aclc,
977 			       struct smc_init_info *ini)
978 {
979 	int i;
980 
981 	for (i = 0; i < ini->ism_offered_cnt + 1; i++) {
982 		if (ini->ism_chid[i] == ntohs(aclc->d1.chid)) {
983 			ini->ism_selected = i;
984 			return 0;
985 		}
986 	}
987 
988 	return -EPROTO;
989 }
990 
991 /* setup for ISM connection of client */
992 static int smc_connect_ism(struct smc_sock *smc,
993 			   struct smc_clc_msg_accept_confirm *aclc,
994 			   struct smc_init_info *ini)
995 {
996 	u8 *eid = NULL;
997 	int rc = 0;
998 
999 	ini->is_smcd = true;
1000 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
1001 
1002 	if (aclc->hdr.version == SMC_V2) {
1003 		struct smc_clc_msg_accept_confirm_v2 *aclc_v2 =
1004 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1005 
1006 		rc = smc_v2_determine_accepted_chid(aclc_v2, ini);
1007 		if (rc)
1008 			return rc;
1009 	}
1010 	ini->ism_peer_gid[ini->ism_selected] = aclc->d0.gid;
1011 
1012 	/* there is only one lgr role for SMC-D; use server lock */
1013 	mutex_lock(&smc_server_lgr_pending);
1014 	rc = smc_conn_create(smc, ini);
1015 	if (rc) {
1016 		mutex_unlock(&smc_server_lgr_pending);
1017 		return rc;
1018 	}
1019 
1020 	/* Create send and receive buffers */
1021 	rc = smc_buf_create(smc, true);
1022 	if (rc) {
1023 		rc = (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB : SMC_CLC_DECL_MEM;
1024 		goto connect_abort;
1025 	}
1026 
1027 	smc_conn_save_peer_info(smc, aclc);
1028 	smc_close_init(smc);
1029 	smc_rx_init(smc);
1030 	smc_tx_init(smc);
1031 
1032 	if (aclc->hdr.version > SMC_V1) {
1033 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
1034 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1035 
1036 		eid = clc_v2->d1.eid;
1037 	}
1038 
1039 	rc = smc_clc_send_confirm(smc, ini->first_contact_local,
1040 				  aclc->hdr.version, eid, NULL);
1041 	if (rc)
1042 		goto connect_abort;
1043 	mutex_unlock(&smc_server_lgr_pending);
1044 
1045 	smc_copy_sock_settings_to_clc(smc);
1046 	smc->connect_nonblock = 0;
1047 	if (smc->sk.sk_state == SMC_INIT)
1048 		smc->sk.sk_state = SMC_ACTIVE;
1049 
1050 	return 0;
1051 connect_abort:
1052 	smc_conn_abort(smc, ini->first_contact_local);
1053 	mutex_unlock(&smc_server_lgr_pending);
1054 	smc->connect_nonblock = 0;
1055 
1056 	return rc;
1057 }
1058 
1059 /* check if received accept type and version matches a proposed one */
1060 static int smc_connect_check_aclc(struct smc_init_info *ini,
1061 				  struct smc_clc_msg_accept_confirm *aclc)
1062 {
1063 	if (aclc->hdr.typev1 != SMC_TYPE_R &&
1064 	    aclc->hdr.typev1 != SMC_TYPE_D)
1065 		return SMC_CLC_DECL_MODEUNSUPP;
1066 
1067 	if (aclc->hdr.version >= SMC_V2) {
1068 		if ((aclc->hdr.typev1 == SMC_TYPE_R &&
1069 		     !smcr_indicated(ini->smc_type_v2)) ||
1070 		    (aclc->hdr.typev1 == SMC_TYPE_D &&
1071 		     !smcd_indicated(ini->smc_type_v2)))
1072 			return SMC_CLC_DECL_MODEUNSUPP;
1073 	} else {
1074 		if ((aclc->hdr.typev1 == SMC_TYPE_R &&
1075 		     !smcr_indicated(ini->smc_type_v1)) ||
1076 		    (aclc->hdr.typev1 == SMC_TYPE_D &&
1077 		     !smcd_indicated(ini->smc_type_v1)))
1078 			return SMC_CLC_DECL_MODEUNSUPP;
1079 	}
1080 
1081 	return 0;
1082 }
1083 
1084 /* perform steps before actually connecting */
1085 static int __smc_connect(struct smc_sock *smc)
1086 {
1087 	u8 version = smc_ism_is_v2_capable() ? SMC_V2 : SMC_V1;
1088 	struct smc_clc_msg_accept_confirm_v2 *aclc2;
1089 	struct smc_clc_msg_accept_confirm *aclc;
1090 	struct smc_init_info *ini = NULL;
1091 	u8 *buf = NULL;
1092 	int rc = 0;
1093 
1094 	if (smc->use_fallback)
1095 		return smc_connect_fallback(smc, smc->fallback_rsn);
1096 
1097 	/* if peer has not signalled SMC-capability, fall back */
1098 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
1099 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
1100 
1101 	/* IPSec connections opt out of SMC optimizations */
1102 	if (using_ipsec(smc))
1103 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC,
1104 						    version);
1105 
1106 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1107 	if (!ini)
1108 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_MEM,
1109 						    version);
1110 
1111 	ini->smcd_version = SMC_V1 | SMC_V2;
1112 	ini->smcr_version = SMC_V1 | SMC_V2;
1113 	ini->smc_type_v1 = SMC_TYPE_B;
1114 	ini->smc_type_v2 = SMC_TYPE_B;
1115 
1116 	/* get vlan id from IP device */
1117 	if (smc_vlan_by_tcpsk(smc->clcsock, ini)) {
1118 		ini->smcd_version &= ~SMC_V1;
1119 		ini->smcr_version = 0;
1120 		ini->smc_type_v1 = SMC_TYPE_N;
1121 		if (!ini->smcd_version) {
1122 			rc = SMC_CLC_DECL_GETVLANERR;
1123 			goto fallback;
1124 		}
1125 	}
1126 
1127 	rc = smc_find_proposal_devices(smc, ini);
1128 	if (rc)
1129 		goto fallback;
1130 
1131 	buf = kzalloc(SMC_CLC_MAX_ACCEPT_LEN, GFP_KERNEL);
1132 	if (!buf) {
1133 		rc = SMC_CLC_DECL_MEM;
1134 		goto fallback;
1135 	}
1136 	aclc2 = (struct smc_clc_msg_accept_confirm_v2 *)buf;
1137 	aclc = (struct smc_clc_msg_accept_confirm *)aclc2;
1138 
1139 	/* perform CLC handshake */
1140 	rc = smc_connect_clc(smc, aclc2, ini);
1141 	if (rc)
1142 		goto vlan_cleanup;
1143 
1144 	/* check if smc modes and versions of CLC proposal and accept match */
1145 	rc = smc_connect_check_aclc(ini, aclc);
1146 	version = aclc->hdr.version == SMC_V1 ? SMC_V1 : SMC_V2;
1147 	if (rc)
1148 		goto vlan_cleanup;
1149 
1150 	/* depending on previous steps, connect using rdma or ism */
1151 	if (aclc->hdr.typev1 == SMC_TYPE_R) {
1152 		ini->smcr_version = version;
1153 		rc = smc_connect_rdma(smc, aclc, ini);
1154 	} else if (aclc->hdr.typev1 == SMC_TYPE_D) {
1155 		ini->smcd_version = version;
1156 		rc = smc_connect_ism(smc, aclc, ini);
1157 	}
1158 	if (rc)
1159 		goto vlan_cleanup;
1160 
1161 	SMC_STAT_CLNT_SUCC_INC(sock_net(smc->clcsock->sk), aclc);
1162 	smc_connect_ism_vlan_cleanup(smc, ini);
1163 	kfree(buf);
1164 	kfree(ini);
1165 	return 0;
1166 
1167 vlan_cleanup:
1168 	smc_connect_ism_vlan_cleanup(smc, ini);
1169 	kfree(buf);
1170 fallback:
1171 	kfree(ini);
1172 	return smc_connect_decline_fallback(smc, rc, version);
1173 }
1174 
1175 static void smc_connect_work(struct work_struct *work)
1176 {
1177 	struct smc_sock *smc = container_of(work, struct smc_sock,
1178 					    connect_work);
1179 	long timeo = smc->sk.sk_sndtimeo;
1180 	int rc = 0;
1181 
1182 	if (!timeo)
1183 		timeo = MAX_SCHEDULE_TIMEOUT;
1184 	lock_sock(smc->clcsock->sk);
1185 	if (smc->clcsock->sk->sk_err) {
1186 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
1187 	} else if ((1 << smc->clcsock->sk->sk_state) &
1188 					(TCPF_SYN_SENT | TCP_SYN_RECV)) {
1189 		rc = sk_stream_wait_connect(smc->clcsock->sk, &timeo);
1190 		if ((rc == -EPIPE) &&
1191 		    ((1 << smc->clcsock->sk->sk_state) &
1192 					(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))
1193 			rc = 0;
1194 	}
1195 	release_sock(smc->clcsock->sk);
1196 	lock_sock(&smc->sk);
1197 	if (rc != 0 || smc->sk.sk_err) {
1198 		smc->sk.sk_state = SMC_CLOSED;
1199 		if (rc == -EPIPE || rc == -EAGAIN)
1200 			smc->sk.sk_err = EPIPE;
1201 		else if (signal_pending(current))
1202 			smc->sk.sk_err = -sock_intr_errno(timeo);
1203 		sock_put(&smc->sk); /* passive closing */
1204 		goto out;
1205 	}
1206 
1207 	rc = __smc_connect(smc);
1208 	if (rc < 0)
1209 		smc->sk.sk_err = -rc;
1210 
1211 out:
1212 	if (!sock_flag(&smc->sk, SOCK_DEAD)) {
1213 		if (smc->sk.sk_err) {
1214 			smc->sk.sk_state_change(&smc->sk);
1215 		} else { /* allow polling before and after fallback decision */
1216 			smc->clcsock->sk->sk_write_space(smc->clcsock->sk);
1217 			smc->sk.sk_write_space(&smc->sk);
1218 		}
1219 	}
1220 	release_sock(&smc->sk);
1221 }
1222 
1223 static int smc_connect(struct socket *sock, struct sockaddr *addr,
1224 		       int alen, int flags)
1225 {
1226 	struct sock *sk = sock->sk;
1227 	struct smc_sock *smc;
1228 	int rc = -EINVAL;
1229 
1230 	smc = smc_sk(sk);
1231 
1232 	/* separate smc parameter checking to be safe */
1233 	if (alen < sizeof(addr->sa_family))
1234 		goto out_err;
1235 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
1236 		goto out_err;
1237 
1238 	lock_sock(sk);
1239 	switch (sk->sk_state) {
1240 	default:
1241 		goto out;
1242 	case SMC_ACTIVE:
1243 		rc = -EISCONN;
1244 		goto out;
1245 	case SMC_INIT:
1246 		break;
1247 	}
1248 
1249 	smc_copy_sock_settings_to_clc(smc);
1250 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1251 	if (smc->connect_nonblock) {
1252 		rc = -EALREADY;
1253 		goto out;
1254 	}
1255 	rc = kernel_connect(smc->clcsock, addr, alen, flags);
1256 	if (rc && rc != -EINPROGRESS)
1257 		goto out;
1258 
1259 	sock_hold(&smc->sk); /* sock put in passive closing */
1260 	if (smc->use_fallback)
1261 		goto out;
1262 	if (flags & O_NONBLOCK) {
1263 		if (queue_work(smc_hs_wq, &smc->connect_work))
1264 			smc->connect_nonblock = 1;
1265 		rc = -EINPROGRESS;
1266 	} else {
1267 		rc = __smc_connect(smc);
1268 		if (rc < 0)
1269 			goto out;
1270 		else
1271 			rc = 0; /* success cases including fallback */
1272 	}
1273 
1274 out:
1275 	release_sock(sk);
1276 out_err:
1277 	return rc;
1278 }
1279 
1280 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
1281 {
1282 	struct socket *new_clcsock = NULL;
1283 	struct sock *lsk = &lsmc->sk;
1284 	struct sock *new_sk;
1285 	int rc = -EINVAL;
1286 
1287 	release_sock(lsk);
1288 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
1289 	if (!new_sk) {
1290 		rc = -ENOMEM;
1291 		lsk->sk_err = ENOMEM;
1292 		*new_smc = NULL;
1293 		lock_sock(lsk);
1294 		goto out;
1295 	}
1296 	*new_smc = smc_sk(new_sk);
1297 
1298 	mutex_lock(&lsmc->clcsock_release_lock);
1299 	if (lsmc->clcsock)
1300 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, SOCK_NONBLOCK);
1301 	mutex_unlock(&lsmc->clcsock_release_lock);
1302 	lock_sock(lsk);
1303 	if  (rc < 0 && rc != -EAGAIN)
1304 		lsk->sk_err = -rc;
1305 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
1306 		new_sk->sk_prot->unhash(new_sk);
1307 		if (new_clcsock)
1308 			sock_release(new_clcsock);
1309 		new_sk->sk_state = SMC_CLOSED;
1310 		sock_set_flag(new_sk, SOCK_DEAD);
1311 		sock_put(new_sk); /* final */
1312 		*new_smc = NULL;
1313 		goto out;
1314 	}
1315 
1316 	/* new clcsock has inherited the smc listen-specific sk_data_ready
1317 	 * function; switch it back to the original sk_data_ready function
1318 	 */
1319 	new_clcsock->sk->sk_data_ready = lsmc->clcsk_data_ready;
1320 	(*new_smc)->clcsock = new_clcsock;
1321 out:
1322 	return rc;
1323 }
1324 
1325 /* add a just created sock to the accept queue of the listen sock as
1326  * candidate for a following socket accept call from user space
1327  */
1328 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
1329 {
1330 	struct smc_sock *par = smc_sk(parent);
1331 
1332 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
1333 	spin_lock(&par->accept_q_lock);
1334 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
1335 	spin_unlock(&par->accept_q_lock);
1336 	sk_acceptq_added(parent);
1337 }
1338 
1339 /* remove a socket from the accept queue of its parental listening socket */
1340 static void smc_accept_unlink(struct sock *sk)
1341 {
1342 	struct smc_sock *par = smc_sk(sk)->listen_smc;
1343 
1344 	spin_lock(&par->accept_q_lock);
1345 	list_del_init(&smc_sk(sk)->accept_q);
1346 	spin_unlock(&par->accept_q_lock);
1347 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
1348 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
1349 }
1350 
1351 /* remove a sock from the accept queue to bind it to a new socket created
1352  * for a socket accept call from user space
1353  */
1354 struct sock *smc_accept_dequeue(struct sock *parent,
1355 				struct socket *new_sock)
1356 {
1357 	struct smc_sock *isk, *n;
1358 	struct sock *new_sk;
1359 
1360 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
1361 		new_sk = (struct sock *)isk;
1362 
1363 		smc_accept_unlink(new_sk);
1364 		if (new_sk->sk_state == SMC_CLOSED) {
1365 			new_sk->sk_prot->unhash(new_sk);
1366 			if (isk->clcsock) {
1367 				sock_release(isk->clcsock);
1368 				isk->clcsock = NULL;
1369 			}
1370 			sock_put(new_sk); /* final */
1371 			continue;
1372 		}
1373 		if (new_sock) {
1374 			sock_graft(new_sk, new_sock);
1375 			if (isk->use_fallback) {
1376 				smc_sk(new_sk)->clcsock->file = new_sock->file;
1377 				isk->clcsock->file->private_data = isk->clcsock;
1378 			}
1379 		}
1380 		return new_sk;
1381 	}
1382 	return NULL;
1383 }
1384 
1385 /* clean up for a created but never accepted sock */
1386 void smc_close_non_accepted(struct sock *sk)
1387 {
1388 	struct smc_sock *smc = smc_sk(sk);
1389 
1390 	sock_hold(sk); /* sock_put below */
1391 	lock_sock(sk);
1392 	if (!sk->sk_lingertime)
1393 		/* wait for peer closing */
1394 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
1395 	__smc_release(smc);
1396 	release_sock(sk);
1397 	sock_put(sk); /* sock_hold above */
1398 	sock_put(sk); /* final sock_put */
1399 }
1400 
1401 static int smcr_serv_conf_first_link(struct smc_sock *smc)
1402 {
1403 	struct smc_link *link = smc->conn.lnk;
1404 	struct smc_llc_qentry *qentry;
1405 	int rc;
1406 
1407 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc))
1408 		return SMC_CLC_DECL_ERR_REGRMB;
1409 
1410 	/* send CONFIRM LINK request to client over the RoCE fabric */
1411 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
1412 	if (rc < 0)
1413 		return SMC_CLC_DECL_TIMEOUT_CL;
1414 
1415 	/* receive CONFIRM LINK response from client over the RoCE fabric */
1416 	qentry = smc_llc_wait(link->lgr, link, SMC_LLC_WAIT_TIME,
1417 			      SMC_LLC_CONFIRM_LINK);
1418 	if (!qentry) {
1419 		struct smc_clc_msg_decline dclc;
1420 
1421 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1422 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1423 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
1424 	}
1425 	smc_llc_save_peer_uid(qentry);
1426 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_RESP);
1427 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
1428 	if (rc)
1429 		return SMC_CLC_DECL_RMBE_EC;
1430 
1431 	/* confirm_rkey is implicit on 1st contact */
1432 	smc->conn.rmb_desc->is_conf_rkey = true;
1433 
1434 	smc_llc_link_active(link);
1435 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
1436 
1437 	/* initial contact - try to establish second link */
1438 	smc_llc_srv_add_link(link, NULL);
1439 	return 0;
1440 }
1441 
1442 /* listen worker: finish */
1443 static void smc_listen_out(struct smc_sock *new_smc)
1444 {
1445 	struct smc_sock *lsmc = new_smc->listen_smc;
1446 	struct sock *newsmcsk = &new_smc->sk;
1447 
1448 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1449 		lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1450 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1451 		release_sock(&lsmc->sk);
1452 	} else { /* no longer listening */
1453 		smc_close_non_accepted(newsmcsk);
1454 	}
1455 
1456 	/* Wake up accept */
1457 	lsmc->sk.sk_data_ready(&lsmc->sk);
1458 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1459 }
1460 
1461 /* listen worker: finish in state connected */
1462 static void smc_listen_out_connected(struct smc_sock *new_smc)
1463 {
1464 	struct sock *newsmcsk = &new_smc->sk;
1465 
1466 	sk_refcnt_debug_inc(newsmcsk);
1467 	if (newsmcsk->sk_state == SMC_INIT)
1468 		newsmcsk->sk_state = SMC_ACTIVE;
1469 
1470 	smc_listen_out(new_smc);
1471 }
1472 
1473 /* listen worker: finish in error state */
1474 static void smc_listen_out_err(struct smc_sock *new_smc)
1475 {
1476 	struct sock *newsmcsk = &new_smc->sk;
1477 	struct net *net = sock_net(newsmcsk);
1478 
1479 	this_cpu_inc(net->smc.smc_stats->srv_hshake_err_cnt);
1480 	if (newsmcsk->sk_state == SMC_INIT)
1481 		sock_put(&new_smc->sk); /* passive closing */
1482 	newsmcsk->sk_state = SMC_CLOSED;
1483 
1484 	smc_listen_out(new_smc);
1485 }
1486 
1487 /* listen worker: decline and fall back if possible */
1488 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1489 			       int local_first, u8 version)
1490 {
1491 	/* RDMA setup failed, switch back to TCP */
1492 	smc_conn_abort(new_smc, local_first);
1493 	if (reason_code < 0) { /* error, no fallback possible */
1494 		smc_listen_out_err(new_smc);
1495 		return;
1496 	}
1497 	smc_switch_to_fallback(new_smc, reason_code);
1498 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1499 		if (smc_clc_send_decline(new_smc, reason_code, version) < 0) {
1500 			smc_listen_out_err(new_smc);
1501 			return;
1502 		}
1503 	}
1504 	smc_listen_out_connected(new_smc);
1505 }
1506 
1507 /* listen worker: version checking */
1508 static int smc_listen_v2_check(struct smc_sock *new_smc,
1509 			       struct smc_clc_msg_proposal *pclc,
1510 			       struct smc_init_info *ini)
1511 {
1512 	struct smc_clc_smcd_v2_extension *pclc_smcd_v2_ext;
1513 	struct smc_clc_v2_extension *pclc_v2_ext;
1514 	int rc = SMC_CLC_DECL_PEERNOSMC;
1515 
1516 	ini->smc_type_v1 = pclc->hdr.typev1;
1517 	ini->smc_type_v2 = pclc->hdr.typev2;
1518 	ini->smcd_version = smcd_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
1519 	ini->smcr_version = smcr_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
1520 	if (pclc->hdr.version > SMC_V1) {
1521 		if (smcd_indicated(ini->smc_type_v2))
1522 			ini->smcd_version |= SMC_V2;
1523 		if (smcr_indicated(ini->smc_type_v2))
1524 			ini->smcr_version |= SMC_V2;
1525 	}
1526 	if (!(ini->smcd_version & SMC_V2) && !(ini->smcr_version & SMC_V2)) {
1527 		rc = SMC_CLC_DECL_PEERNOSMC;
1528 		goto out;
1529 	}
1530 	pclc_v2_ext = smc_get_clc_v2_ext(pclc);
1531 	if (!pclc_v2_ext) {
1532 		ini->smcd_version &= ~SMC_V2;
1533 		ini->smcr_version &= ~SMC_V2;
1534 		rc = SMC_CLC_DECL_NOV2EXT;
1535 		goto out;
1536 	}
1537 	pclc_smcd_v2_ext = smc_get_clc_smcd_v2_ext(pclc_v2_ext);
1538 	if (ini->smcd_version & SMC_V2) {
1539 		if (!smc_ism_is_v2_capable()) {
1540 			ini->smcd_version &= ~SMC_V2;
1541 			rc = SMC_CLC_DECL_NOISM2SUPP;
1542 		} else if (!pclc_smcd_v2_ext) {
1543 			ini->smcd_version &= ~SMC_V2;
1544 			rc = SMC_CLC_DECL_NOV2DEXT;
1545 		} else if (!pclc_v2_ext->hdr.eid_cnt &&
1546 			   !pclc_v2_ext->hdr.flag.seid) {
1547 			ini->smcd_version &= ~SMC_V2;
1548 			rc = SMC_CLC_DECL_NOUEID;
1549 		}
1550 	}
1551 	if (ini->smcr_version & SMC_V2) {
1552 		if (!pclc_v2_ext->hdr.eid_cnt) {
1553 			ini->smcr_version &= ~SMC_V2;
1554 			rc = SMC_CLC_DECL_NOUEID;
1555 		}
1556 	}
1557 
1558 out:
1559 	if (!ini->smcd_version && !ini->smcr_version)
1560 		return rc;
1561 
1562 	return 0;
1563 }
1564 
1565 /* listen worker: check prefixes */
1566 static int smc_listen_prfx_check(struct smc_sock *new_smc,
1567 				 struct smc_clc_msg_proposal *pclc)
1568 {
1569 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1570 	struct socket *newclcsock = new_smc->clcsock;
1571 
1572 	if (pclc->hdr.typev1 == SMC_TYPE_N)
1573 		return 0;
1574 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1575 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1576 		return SMC_CLC_DECL_DIFFPREFIX;
1577 
1578 	return 0;
1579 }
1580 
1581 /* listen worker: initialize connection and buffers */
1582 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1583 				struct smc_init_info *ini)
1584 {
1585 	int rc;
1586 
1587 	/* allocate connection / link group */
1588 	rc = smc_conn_create(new_smc, ini);
1589 	if (rc)
1590 		return rc;
1591 
1592 	/* create send buffer and rmb */
1593 	if (smc_buf_create(new_smc, false))
1594 		return SMC_CLC_DECL_MEM;
1595 
1596 	return 0;
1597 }
1598 
1599 /* listen worker: initialize connection and buffers for SMC-D */
1600 static int smc_listen_ism_init(struct smc_sock *new_smc,
1601 			       struct smc_init_info *ini)
1602 {
1603 	int rc;
1604 
1605 	rc = smc_conn_create(new_smc, ini);
1606 	if (rc)
1607 		return rc;
1608 
1609 	/* Create send and receive buffers */
1610 	rc = smc_buf_create(new_smc, true);
1611 	if (rc) {
1612 		smc_conn_abort(new_smc, ini->first_contact_local);
1613 		return (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB :
1614 					 SMC_CLC_DECL_MEM;
1615 	}
1616 
1617 	return 0;
1618 }
1619 
1620 static bool smc_is_already_selected(struct smcd_dev *smcd,
1621 				    struct smc_init_info *ini,
1622 				    int matches)
1623 {
1624 	int i;
1625 
1626 	for (i = 0; i < matches; i++)
1627 		if (smcd == ini->ism_dev[i])
1628 			return true;
1629 
1630 	return false;
1631 }
1632 
1633 /* check for ISM devices matching proposed ISM devices */
1634 static void smc_check_ism_v2_match(struct smc_init_info *ini,
1635 				   u16 proposed_chid, u64 proposed_gid,
1636 				   unsigned int *matches)
1637 {
1638 	struct smcd_dev *smcd;
1639 
1640 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
1641 		if (smcd->going_away)
1642 			continue;
1643 		if (smc_is_already_selected(smcd, ini, *matches))
1644 			continue;
1645 		if (smc_ism_get_chid(smcd) == proposed_chid &&
1646 		    !smc_ism_cantalk(proposed_gid, ISM_RESERVED_VLANID, smcd)) {
1647 			ini->ism_peer_gid[*matches] = proposed_gid;
1648 			ini->ism_dev[*matches] = smcd;
1649 			(*matches)++;
1650 			break;
1651 		}
1652 	}
1653 }
1654 
1655 static void smc_find_ism_store_rc(u32 rc, struct smc_init_info *ini)
1656 {
1657 	if (!ini->rc)
1658 		ini->rc = rc;
1659 }
1660 
1661 static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
1662 					struct smc_clc_msg_proposal *pclc,
1663 					struct smc_init_info *ini)
1664 {
1665 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
1666 	struct smc_clc_v2_extension *smc_v2_ext;
1667 	struct smc_clc_msg_smcd *pclc_smcd;
1668 	unsigned int matches = 0;
1669 	u8 smcd_version;
1670 	u8 *eid = NULL;
1671 	int i, rc;
1672 
1673 	if (!(ini->smcd_version & SMC_V2) || !smcd_indicated(ini->smc_type_v2))
1674 		goto not_found;
1675 
1676 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
1677 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
1678 	smcd_v2_ext = smc_get_clc_smcd_v2_ext(smc_v2_ext);
1679 
1680 	mutex_lock(&smcd_dev_list.mutex);
1681 	if (pclc_smcd->ism.chid)
1682 		/* check for ISM device matching proposed native ISM device */
1683 		smc_check_ism_v2_match(ini, ntohs(pclc_smcd->ism.chid),
1684 				       ntohll(pclc_smcd->ism.gid), &matches);
1685 	for (i = 1; i <= smc_v2_ext->hdr.ism_gid_cnt; i++) {
1686 		/* check for ISM devices matching proposed non-native ISM
1687 		 * devices
1688 		 */
1689 		smc_check_ism_v2_match(ini,
1690 				       ntohs(smcd_v2_ext->gidchid[i - 1].chid),
1691 				       ntohll(smcd_v2_ext->gidchid[i - 1].gid),
1692 				       &matches);
1693 	}
1694 	mutex_unlock(&smcd_dev_list.mutex);
1695 
1696 	if (!ini->ism_dev[0]) {
1697 		smc_find_ism_store_rc(SMC_CLC_DECL_NOSMCD2DEV, ini);
1698 		goto not_found;
1699 	}
1700 
1701 	smc_ism_get_system_eid(&eid);
1702 	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext,
1703 			       smcd_v2_ext->system_eid, eid))
1704 		goto not_found;
1705 
1706 	/* separate - outside the smcd_dev_list.lock */
1707 	smcd_version = ini->smcd_version;
1708 	for (i = 0; i < matches; i++) {
1709 		ini->smcd_version = SMC_V2;
1710 		ini->is_smcd = true;
1711 		ini->ism_selected = i;
1712 		rc = smc_listen_ism_init(new_smc, ini);
1713 		if (rc) {
1714 			smc_find_ism_store_rc(rc, ini);
1715 			/* try next active ISM device */
1716 			continue;
1717 		}
1718 		return; /* matching and usable V2 ISM device found */
1719 	}
1720 	/* no V2 ISM device could be initialized */
1721 	ini->smcd_version = smcd_version;	/* restore original value */
1722 	ini->negotiated_eid[0] = 0;
1723 
1724 not_found:
1725 	ini->smcd_version &= ~SMC_V2;
1726 	ini->ism_dev[0] = NULL;
1727 	ini->is_smcd = false;
1728 }
1729 
1730 static void smc_find_ism_v1_device_serv(struct smc_sock *new_smc,
1731 					struct smc_clc_msg_proposal *pclc,
1732 					struct smc_init_info *ini)
1733 {
1734 	struct smc_clc_msg_smcd *pclc_smcd = smc_get_clc_msg_smcd(pclc);
1735 	int rc = 0;
1736 
1737 	/* check if ISM V1 is available */
1738 	if (!(ini->smcd_version & SMC_V1) || !smcd_indicated(ini->smc_type_v1))
1739 		goto not_found;
1740 	ini->is_smcd = true; /* prepare ISM check */
1741 	ini->ism_peer_gid[0] = ntohll(pclc_smcd->ism.gid);
1742 	rc = smc_find_ism_device(new_smc, ini);
1743 	if (rc)
1744 		goto not_found;
1745 	ini->ism_selected = 0;
1746 	rc = smc_listen_ism_init(new_smc, ini);
1747 	if (!rc)
1748 		return;		/* V1 ISM device found */
1749 
1750 not_found:
1751 	smc_find_ism_store_rc(rc, ini);
1752 	ini->smcd_version &= ~SMC_V1;
1753 	ini->ism_dev[0] = NULL;
1754 	ini->is_smcd = false;
1755 }
1756 
1757 /* listen worker: register buffers */
1758 static int smc_listen_rdma_reg(struct smc_sock *new_smc, bool local_first)
1759 {
1760 	struct smc_connection *conn = &new_smc->conn;
1761 
1762 	if (!local_first) {
1763 		if (smcr_lgr_reg_rmbs(conn->lnk, conn->rmb_desc))
1764 			return SMC_CLC_DECL_ERR_REGRMB;
1765 	}
1766 	smc_rmb_sync_sg_for_device(&new_smc->conn);
1767 
1768 	return 0;
1769 }
1770 
1771 static void smc_find_rdma_v2_device_serv(struct smc_sock *new_smc,
1772 					 struct smc_clc_msg_proposal *pclc,
1773 					 struct smc_init_info *ini)
1774 {
1775 	struct smc_clc_v2_extension *smc_v2_ext;
1776 	u8 smcr_version;
1777 	int rc;
1778 
1779 	if (!(ini->smcr_version & SMC_V2) || !smcr_indicated(ini->smc_type_v2))
1780 		goto not_found;
1781 
1782 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
1783 	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext, NULL, NULL))
1784 		goto not_found;
1785 
1786 	/* prepare RDMA check */
1787 	memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
1788 	memcpy(ini->peer_gid, smc_v2_ext->roce, SMC_GID_SIZE);
1789 	memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
1790 	ini->check_smcrv2 = true;
1791 	ini->smcrv2.clc_sk = new_smc->clcsock->sk;
1792 	ini->smcrv2.saddr = new_smc->clcsock->sk->sk_rcv_saddr;
1793 	ini->smcrv2.daddr = smc_ib_gid_to_ipv4(smc_v2_ext->roce);
1794 	rc = smc_find_rdma_device(new_smc, ini);
1795 	if (rc) {
1796 		smc_find_ism_store_rc(rc, ini);
1797 		goto not_found;
1798 	}
1799 	if (!ini->smcrv2.uses_gateway)
1800 		memcpy(ini->smcrv2.nexthop_mac, pclc->lcl.mac, ETH_ALEN);
1801 
1802 	smcr_version = ini->smcr_version;
1803 	ini->smcr_version = SMC_V2;
1804 	rc = smc_listen_rdma_init(new_smc, ini);
1805 	if (!rc)
1806 		rc = smc_listen_rdma_reg(new_smc, ini->first_contact_local);
1807 	if (!rc)
1808 		return;
1809 	ini->smcr_version = smcr_version;
1810 	smc_find_ism_store_rc(rc, ini);
1811 
1812 not_found:
1813 	ini->smcr_version &= ~SMC_V2;
1814 	ini->check_smcrv2 = false;
1815 }
1816 
1817 static int smc_find_rdma_v1_device_serv(struct smc_sock *new_smc,
1818 					struct smc_clc_msg_proposal *pclc,
1819 					struct smc_init_info *ini)
1820 {
1821 	int rc;
1822 
1823 	if (!(ini->smcr_version & SMC_V1) || !smcr_indicated(ini->smc_type_v1))
1824 		return SMC_CLC_DECL_NOSMCDEV;
1825 
1826 	/* prepare RDMA check */
1827 	memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
1828 	memcpy(ini->peer_gid, pclc->lcl.gid, SMC_GID_SIZE);
1829 	memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
1830 	rc = smc_find_rdma_device(new_smc, ini);
1831 	if (rc) {
1832 		/* no RDMA device found */
1833 		return SMC_CLC_DECL_NOSMCDEV;
1834 	}
1835 	rc = smc_listen_rdma_init(new_smc, ini);
1836 	if (rc)
1837 		return rc;
1838 	return smc_listen_rdma_reg(new_smc, ini->first_contact_local);
1839 }
1840 
1841 /* determine the local device matching to proposal */
1842 static int smc_listen_find_device(struct smc_sock *new_smc,
1843 				  struct smc_clc_msg_proposal *pclc,
1844 				  struct smc_init_info *ini)
1845 {
1846 	int prfx_rc;
1847 
1848 	/* check for ISM device matching V2 proposed device */
1849 	smc_find_ism_v2_device_serv(new_smc, pclc, ini);
1850 	if (ini->ism_dev[0])
1851 		return 0;
1852 
1853 	/* check for matching IP prefix and subnet length (V1) */
1854 	prfx_rc = smc_listen_prfx_check(new_smc, pclc);
1855 	if (prfx_rc)
1856 		smc_find_ism_store_rc(prfx_rc, ini);
1857 
1858 	/* get vlan id from IP device */
1859 	if (smc_vlan_by_tcpsk(new_smc->clcsock, ini))
1860 		return ini->rc ?: SMC_CLC_DECL_GETVLANERR;
1861 
1862 	/* check for ISM device matching V1 proposed device */
1863 	if (!prfx_rc)
1864 		smc_find_ism_v1_device_serv(new_smc, pclc, ini);
1865 	if (ini->ism_dev[0])
1866 		return 0;
1867 
1868 	if (!smcr_indicated(pclc->hdr.typev1) &&
1869 	    !smcr_indicated(pclc->hdr.typev2))
1870 		/* skip RDMA and decline */
1871 		return ini->rc ?: SMC_CLC_DECL_NOSMCDDEV;
1872 
1873 	/* check if RDMA V2 is available */
1874 	smc_find_rdma_v2_device_serv(new_smc, pclc, ini);
1875 	if (ini->smcrv2.ib_dev_v2)
1876 		return 0;
1877 
1878 	/* check if RDMA V1 is available */
1879 	if (!prfx_rc) {
1880 		int rc;
1881 
1882 		rc = smc_find_rdma_v1_device_serv(new_smc, pclc, ini);
1883 		smc_find_ism_store_rc(rc, ini);
1884 		return (!rc) ? 0 : ini->rc;
1885 	}
1886 	return SMC_CLC_DECL_NOSMCDEV;
1887 }
1888 
1889 /* listen worker: finish RDMA setup */
1890 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
1891 				  struct smc_clc_msg_accept_confirm *cclc,
1892 				  bool local_first,
1893 				  struct smc_init_info *ini)
1894 {
1895 	struct smc_link *link = new_smc->conn.lnk;
1896 	int reason_code = 0;
1897 
1898 	if (local_first)
1899 		smc_link_save_peer_info(link, cclc, ini);
1900 
1901 	if (smc_rmb_rtoken_handling(&new_smc->conn, link, cclc))
1902 		return SMC_CLC_DECL_ERR_RTOK;
1903 
1904 	if (local_first) {
1905 		if (smc_ib_ready_link(link))
1906 			return SMC_CLC_DECL_ERR_RDYLNK;
1907 		/* QP confirmation over RoCE fabric */
1908 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
1909 		reason_code = smcr_serv_conf_first_link(new_smc);
1910 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
1911 	}
1912 	return reason_code;
1913 }
1914 
1915 /* setup for connection of server */
1916 static void smc_listen_work(struct work_struct *work)
1917 {
1918 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
1919 						smc_listen_work);
1920 	struct socket *newclcsock = new_smc->clcsock;
1921 	struct smc_clc_msg_accept_confirm *cclc;
1922 	struct smc_clc_msg_proposal_area *buf;
1923 	struct smc_clc_msg_proposal *pclc;
1924 	struct smc_init_info *ini = NULL;
1925 	u8 proposal_version = SMC_V1;
1926 	u8 accept_version;
1927 	int rc = 0;
1928 
1929 	if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
1930 		return smc_listen_out_err(new_smc);
1931 
1932 	if (new_smc->use_fallback) {
1933 		smc_listen_out_connected(new_smc);
1934 		return;
1935 	}
1936 
1937 	/* check if peer is smc capable */
1938 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
1939 		smc_switch_to_fallback(new_smc, SMC_CLC_DECL_PEERNOSMC);
1940 		smc_listen_out_connected(new_smc);
1941 		return;
1942 	}
1943 
1944 	/* do inband token exchange -
1945 	 * wait for and receive SMC Proposal CLC message
1946 	 */
1947 	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
1948 	if (!buf) {
1949 		rc = SMC_CLC_DECL_MEM;
1950 		goto out_decl;
1951 	}
1952 	pclc = (struct smc_clc_msg_proposal *)buf;
1953 	rc = smc_clc_wait_msg(new_smc, pclc, sizeof(*buf),
1954 			      SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
1955 	if (rc)
1956 		goto out_decl;
1957 
1958 	if (pclc->hdr.version > SMC_V1)
1959 		proposal_version = SMC_V2;
1960 
1961 	/* IPSec connections opt out of SMC optimizations */
1962 	if (using_ipsec(new_smc)) {
1963 		rc = SMC_CLC_DECL_IPSEC;
1964 		goto out_decl;
1965 	}
1966 
1967 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1968 	if (!ini) {
1969 		rc = SMC_CLC_DECL_MEM;
1970 		goto out_decl;
1971 	}
1972 
1973 	/* initial version checking */
1974 	rc = smc_listen_v2_check(new_smc, pclc, ini);
1975 	if (rc)
1976 		goto out_decl;
1977 
1978 	mutex_lock(&smc_server_lgr_pending);
1979 	smc_close_init(new_smc);
1980 	smc_rx_init(new_smc);
1981 	smc_tx_init(new_smc);
1982 
1983 	/* determine ISM or RoCE device used for connection */
1984 	rc = smc_listen_find_device(new_smc, pclc, ini);
1985 	if (rc)
1986 		goto out_unlock;
1987 
1988 	/* send SMC Accept CLC message */
1989 	accept_version = ini->is_smcd ? ini->smcd_version : ini->smcr_version;
1990 	rc = smc_clc_send_accept(new_smc, ini->first_contact_local,
1991 				 accept_version, ini->negotiated_eid);
1992 	if (rc)
1993 		goto out_unlock;
1994 
1995 	/* SMC-D does not need this lock any more */
1996 	if (ini->is_smcd)
1997 		mutex_unlock(&smc_server_lgr_pending);
1998 
1999 	/* receive SMC Confirm CLC message */
2000 	memset(buf, 0, sizeof(*buf));
2001 	cclc = (struct smc_clc_msg_accept_confirm *)buf;
2002 	rc = smc_clc_wait_msg(new_smc, cclc, sizeof(*buf),
2003 			      SMC_CLC_CONFIRM, CLC_WAIT_TIME);
2004 	if (rc) {
2005 		if (!ini->is_smcd)
2006 			goto out_unlock;
2007 		goto out_decl;
2008 	}
2009 
2010 	/* finish worker */
2011 	if (!ini->is_smcd) {
2012 		rc = smc_listen_rdma_finish(new_smc, cclc,
2013 					    ini->first_contact_local, ini);
2014 		if (rc)
2015 			goto out_unlock;
2016 		mutex_unlock(&smc_server_lgr_pending);
2017 	}
2018 	smc_conn_save_peer_info(new_smc, cclc);
2019 	smc_listen_out_connected(new_smc);
2020 	SMC_STAT_SERV_SUCC_INC(sock_net(newclcsock->sk), ini);
2021 	goto out_free;
2022 
2023 out_unlock:
2024 	mutex_unlock(&smc_server_lgr_pending);
2025 out_decl:
2026 	smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0,
2027 			   proposal_version);
2028 out_free:
2029 	kfree(ini);
2030 	kfree(buf);
2031 }
2032 
2033 static void smc_tcp_listen_work(struct work_struct *work)
2034 {
2035 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
2036 					     tcp_listen_work);
2037 	struct sock *lsk = &lsmc->sk;
2038 	struct smc_sock *new_smc;
2039 	int rc = 0;
2040 
2041 	lock_sock(lsk);
2042 	while (lsk->sk_state == SMC_LISTEN) {
2043 		rc = smc_clcsock_accept(lsmc, &new_smc);
2044 		if (rc) /* clcsock accept queue empty or error */
2045 			goto out;
2046 		if (!new_smc)
2047 			continue;
2048 
2049 		new_smc->listen_smc = lsmc;
2050 		new_smc->use_fallback = lsmc->use_fallback;
2051 		new_smc->fallback_rsn = lsmc->fallback_rsn;
2052 		sock_hold(lsk); /* sock_put in smc_listen_work */
2053 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
2054 		smc_copy_sock_settings_to_smc(new_smc);
2055 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
2056 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
2057 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
2058 		if (!queue_work(smc_hs_wq, &new_smc->smc_listen_work))
2059 			sock_put(&new_smc->sk);
2060 	}
2061 
2062 out:
2063 	release_sock(lsk);
2064 	sock_put(&lsmc->sk); /* sock_hold in smc_clcsock_data_ready() */
2065 }
2066 
2067 static void smc_clcsock_data_ready(struct sock *listen_clcsock)
2068 {
2069 	struct smc_sock *lsmc;
2070 
2071 	lsmc = (struct smc_sock *)
2072 	       ((uintptr_t)listen_clcsock->sk_user_data & ~SK_USER_DATA_NOCOPY);
2073 	if (!lsmc)
2074 		return;
2075 	lsmc->clcsk_data_ready(listen_clcsock);
2076 	if (lsmc->sk.sk_state == SMC_LISTEN) {
2077 		sock_hold(&lsmc->sk); /* sock_put in smc_tcp_listen_work() */
2078 		if (!queue_work(smc_hs_wq, &lsmc->tcp_listen_work))
2079 			sock_put(&lsmc->sk);
2080 	}
2081 }
2082 
2083 static int smc_listen(struct socket *sock, int backlog)
2084 {
2085 	struct sock *sk = sock->sk;
2086 	struct smc_sock *smc;
2087 	int rc;
2088 
2089 	smc = smc_sk(sk);
2090 	lock_sock(sk);
2091 
2092 	rc = -EINVAL;
2093 	if ((sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) ||
2094 	    smc->connect_nonblock)
2095 		goto out;
2096 
2097 	rc = 0;
2098 	if (sk->sk_state == SMC_LISTEN) {
2099 		sk->sk_max_ack_backlog = backlog;
2100 		goto out;
2101 	}
2102 	/* some socket options are handled in core, so we could not apply
2103 	 * them to the clc socket -- copy smc socket options to clc socket
2104 	 */
2105 	smc_copy_sock_settings_to_clc(smc);
2106 	if (!smc->use_fallback)
2107 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
2108 
2109 	/* save original sk_data_ready function and establish
2110 	 * smc-specific sk_data_ready function
2111 	 */
2112 	smc->clcsk_data_ready = smc->clcsock->sk->sk_data_ready;
2113 	smc->clcsock->sk->sk_data_ready = smc_clcsock_data_ready;
2114 	smc->clcsock->sk->sk_user_data =
2115 		(void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
2116 	rc = kernel_listen(smc->clcsock, backlog);
2117 	if (rc)
2118 		goto out;
2119 	sk->sk_max_ack_backlog = backlog;
2120 	sk->sk_ack_backlog = 0;
2121 	sk->sk_state = SMC_LISTEN;
2122 
2123 out:
2124 	release_sock(sk);
2125 	return rc;
2126 }
2127 
2128 static int smc_accept(struct socket *sock, struct socket *new_sock,
2129 		      int flags, bool kern)
2130 {
2131 	struct sock *sk = sock->sk, *nsk;
2132 	DECLARE_WAITQUEUE(wait, current);
2133 	struct smc_sock *lsmc;
2134 	long timeo;
2135 	int rc = 0;
2136 
2137 	lsmc = smc_sk(sk);
2138 	sock_hold(sk); /* sock_put below */
2139 	lock_sock(sk);
2140 
2141 	if (lsmc->sk.sk_state != SMC_LISTEN) {
2142 		rc = -EINVAL;
2143 		release_sock(sk);
2144 		goto out;
2145 	}
2146 
2147 	/* Wait for an incoming connection */
2148 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
2149 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
2150 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
2151 		set_current_state(TASK_INTERRUPTIBLE);
2152 		if (!timeo) {
2153 			rc = -EAGAIN;
2154 			break;
2155 		}
2156 		release_sock(sk);
2157 		timeo = schedule_timeout(timeo);
2158 		/* wakeup by sk_data_ready in smc_listen_work() */
2159 		sched_annotate_sleep();
2160 		lock_sock(sk);
2161 		if (signal_pending(current)) {
2162 			rc = sock_intr_errno(timeo);
2163 			break;
2164 		}
2165 	}
2166 	set_current_state(TASK_RUNNING);
2167 	remove_wait_queue(sk_sleep(sk), &wait);
2168 
2169 	if (!rc)
2170 		rc = sock_error(nsk);
2171 	release_sock(sk);
2172 	if (rc)
2173 		goto out;
2174 
2175 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
2176 		/* wait till data arrives on the socket */
2177 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
2178 								MSEC_PER_SEC);
2179 		if (smc_sk(nsk)->use_fallback) {
2180 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
2181 
2182 			lock_sock(clcsk);
2183 			if (skb_queue_empty(&clcsk->sk_receive_queue))
2184 				sk_wait_data(clcsk, &timeo, NULL);
2185 			release_sock(clcsk);
2186 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
2187 			lock_sock(nsk);
2188 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
2189 			release_sock(nsk);
2190 		}
2191 	}
2192 
2193 out:
2194 	sock_put(sk); /* sock_hold above */
2195 	return rc;
2196 }
2197 
2198 static int smc_getname(struct socket *sock, struct sockaddr *addr,
2199 		       int peer)
2200 {
2201 	struct smc_sock *smc;
2202 
2203 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
2204 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
2205 		return -ENOTCONN;
2206 
2207 	smc = smc_sk(sock->sk);
2208 
2209 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
2210 }
2211 
2212 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2213 {
2214 	struct sock *sk = sock->sk;
2215 	struct smc_sock *smc;
2216 	int rc = -EPIPE;
2217 
2218 	smc = smc_sk(sk);
2219 	lock_sock(sk);
2220 	if ((sk->sk_state != SMC_ACTIVE) &&
2221 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2222 	    (sk->sk_state != SMC_INIT))
2223 		goto out;
2224 
2225 	if (msg->msg_flags & MSG_FASTOPEN) {
2226 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2227 			smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2228 		} else {
2229 			rc = -EINVAL;
2230 			goto out;
2231 		}
2232 	}
2233 
2234 	if (smc->use_fallback) {
2235 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
2236 	} else {
2237 		rc = smc_tx_sendmsg(smc, msg, len);
2238 		SMC_STAT_TX_PAYLOAD(smc, len, rc);
2239 	}
2240 out:
2241 	release_sock(sk);
2242 	return rc;
2243 }
2244 
2245 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2246 		       int flags)
2247 {
2248 	struct sock *sk = sock->sk;
2249 	struct smc_sock *smc;
2250 	int rc = -ENOTCONN;
2251 
2252 	smc = smc_sk(sk);
2253 	lock_sock(sk);
2254 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2255 		/* socket was connected before, no more data to read */
2256 		rc = 0;
2257 		goto out;
2258 	}
2259 	if ((sk->sk_state == SMC_INIT) ||
2260 	    (sk->sk_state == SMC_LISTEN) ||
2261 	    (sk->sk_state == SMC_CLOSED))
2262 		goto out;
2263 
2264 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2265 		rc = 0;
2266 		goto out;
2267 	}
2268 
2269 	if (smc->use_fallback) {
2270 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
2271 	} else {
2272 		msg->msg_namelen = 0;
2273 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
2274 		SMC_STAT_RX_PAYLOAD(smc, rc, rc);
2275 	}
2276 
2277 out:
2278 	release_sock(sk);
2279 	return rc;
2280 }
2281 
2282 static __poll_t smc_accept_poll(struct sock *parent)
2283 {
2284 	struct smc_sock *isk = smc_sk(parent);
2285 	__poll_t mask = 0;
2286 
2287 	spin_lock(&isk->accept_q_lock);
2288 	if (!list_empty(&isk->accept_q))
2289 		mask = EPOLLIN | EPOLLRDNORM;
2290 	spin_unlock(&isk->accept_q_lock);
2291 
2292 	return mask;
2293 }
2294 
2295 static __poll_t smc_poll(struct file *file, struct socket *sock,
2296 			     poll_table *wait)
2297 {
2298 	struct sock *sk = sock->sk;
2299 	struct smc_sock *smc;
2300 	__poll_t mask = 0;
2301 
2302 	if (!sk)
2303 		return EPOLLNVAL;
2304 
2305 	smc = smc_sk(sock->sk);
2306 	if (smc->use_fallback) {
2307 		/* delegate to CLC child sock */
2308 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
2309 		sk->sk_err = smc->clcsock->sk->sk_err;
2310 	} else {
2311 		if (sk->sk_state != SMC_CLOSED)
2312 			sock_poll_wait(file, sock, wait);
2313 		if (sk->sk_err)
2314 			mask |= EPOLLERR;
2315 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
2316 		    (sk->sk_state == SMC_CLOSED))
2317 			mask |= EPOLLHUP;
2318 		if (sk->sk_state == SMC_LISTEN) {
2319 			/* woken up by sk_data_ready in smc_listen_work() */
2320 			mask |= smc_accept_poll(sk);
2321 		} else if (smc->use_fallback) { /* as result of connect_work()*/
2322 			mask |= smc->clcsock->ops->poll(file, smc->clcsock,
2323 							   wait);
2324 			sk->sk_err = smc->clcsock->sk->sk_err;
2325 		} else {
2326 			if ((sk->sk_state != SMC_INIT &&
2327 			     atomic_read(&smc->conn.sndbuf_space)) ||
2328 			    sk->sk_shutdown & SEND_SHUTDOWN) {
2329 				mask |= EPOLLOUT | EPOLLWRNORM;
2330 			} else {
2331 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2332 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2333 			}
2334 			if (atomic_read(&smc->conn.bytes_to_rcv))
2335 				mask |= EPOLLIN | EPOLLRDNORM;
2336 			if (sk->sk_shutdown & RCV_SHUTDOWN)
2337 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
2338 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
2339 				mask |= EPOLLIN;
2340 			if (smc->conn.urg_state == SMC_URG_VALID)
2341 				mask |= EPOLLPRI;
2342 		}
2343 	}
2344 
2345 	return mask;
2346 }
2347 
2348 static int smc_shutdown(struct socket *sock, int how)
2349 {
2350 	struct sock *sk = sock->sk;
2351 	struct smc_sock *smc;
2352 	int rc = -EINVAL;
2353 	int rc1 = 0;
2354 
2355 	smc = smc_sk(sk);
2356 
2357 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
2358 		return rc;
2359 
2360 	lock_sock(sk);
2361 
2362 	rc = -ENOTCONN;
2363 	if ((sk->sk_state != SMC_ACTIVE) &&
2364 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
2365 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
2366 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2367 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
2368 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
2369 		goto out;
2370 	if (smc->use_fallback) {
2371 		rc = kernel_sock_shutdown(smc->clcsock, how);
2372 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
2373 		if (sk->sk_shutdown == SHUTDOWN_MASK)
2374 			sk->sk_state = SMC_CLOSED;
2375 		goto out;
2376 	}
2377 	switch (how) {
2378 	case SHUT_RDWR:		/* shutdown in both directions */
2379 		rc = smc_close_active(smc);
2380 		break;
2381 	case SHUT_WR:
2382 		rc = smc_close_shutdown_write(smc);
2383 		break;
2384 	case SHUT_RD:
2385 		rc = 0;
2386 		/* nothing more to do because peer is not involved */
2387 		break;
2388 	}
2389 	if (smc->clcsock)
2390 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
2391 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
2392 	sk->sk_shutdown |= how + 1;
2393 
2394 out:
2395 	release_sock(sk);
2396 	return rc ? rc : rc1;
2397 }
2398 
2399 static int smc_setsockopt(struct socket *sock, int level, int optname,
2400 			  sockptr_t optval, unsigned int optlen)
2401 {
2402 	struct sock *sk = sock->sk;
2403 	struct smc_sock *smc;
2404 	int val, rc;
2405 
2406 	if (level == SOL_TCP && optname == TCP_ULP)
2407 		return -EOPNOTSUPP;
2408 
2409 	smc = smc_sk(sk);
2410 
2411 	/* generic setsockopts reaching us here always apply to the
2412 	 * CLC socket
2413 	 */
2414 	if (unlikely(!smc->clcsock->ops->setsockopt))
2415 		rc = -EOPNOTSUPP;
2416 	else
2417 		rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
2418 						   optval, optlen);
2419 	if (smc->clcsock->sk->sk_err) {
2420 		sk->sk_err = smc->clcsock->sk->sk_err;
2421 		sk_error_report(sk);
2422 	}
2423 
2424 	if (optlen < sizeof(int))
2425 		return -EINVAL;
2426 	if (copy_from_sockptr(&val, optval, sizeof(int)))
2427 		return -EFAULT;
2428 
2429 	lock_sock(sk);
2430 	if (rc || smc->use_fallback)
2431 		goto out;
2432 	switch (optname) {
2433 	case TCP_FASTOPEN:
2434 	case TCP_FASTOPEN_CONNECT:
2435 	case TCP_FASTOPEN_KEY:
2436 	case TCP_FASTOPEN_NO_COOKIE:
2437 		/* option not supported by SMC */
2438 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2439 			smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2440 		} else {
2441 			rc = -EINVAL;
2442 		}
2443 		break;
2444 	case TCP_NODELAY:
2445 		if (sk->sk_state != SMC_INIT &&
2446 		    sk->sk_state != SMC_LISTEN &&
2447 		    sk->sk_state != SMC_CLOSED) {
2448 			if (val) {
2449 				SMC_STAT_INC(smc, ndly_cnt);
2450 				mod_delayed_work(smc->conn.lgr->tx_wq,
2451 						 &smc->conn.tx_work, 0);
2452 			}
2453 		}
2454 		break;
2455 	case TCP_CORK:
2456 		if (sk->sk_state != SMC_INIT &&
2457 		    sk->sk_state != SMC_LISTEN &&
2458 		    sk->sk_state != SMC_CLOSED) {
2459 			if (!val) {
2460 				SMC_STAT_INC(smc, cork_cnt);
2461 				mod_delayed_work(smc->conn.lgr->tx_wq,
2462 						 &smc->conn.tx_work, 0);
2463 			}
2464 		}
2465 		break;
2466 	case TCP_DEFER_ACCEPT:
2467 		smc->sockopt_defer_accept = val;
2468 		break;
2469 	default:
2470 		break;
2471 	}
2472 out:
2473 	release_sock(sk);
2474 
2475 	return rc;
2476 }
2477 
2478 static int smc_getsockopt(struct socket *sock, int level, int optname,
2479 			  char __user *optval, int __user *optlen)
2480 {
2481 	struct smc_sock *smc;
2482 
2483 	smc = smc_sk(sock->sk);
2484 	/* socket options apply to the CLC socket */
2485 	if (unlikely(!smc->clcsock->ops->getsockopt))
2486 		return -EOPNOTSUPP;
2487 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
2488 					     optval, optlen);
2489 }
2490 
2491 static int smc_ioctl(struct socket *sock, unsigned int cmd,
2492 		     unsigned long arg)
2493 {
2494 	union smc_host_cursor cons, urg;
2495 	struct smc_connection *conn;
2496 	struct smc_sock *smc;
2497 	int answ;
2498 
2499 	smc = smc_sk(sock->sk);
2500 	conn = &smc->conn;
2501 	lock_sock(&smc->sk);
2502 	if (smc->use_fallback) {
2503 		if (!smc->clcsock) {
2504 			release_sock(&smc->sk);
2505 			return -EBADF;
2506 		}
2507 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
2508 		release_sock(&smc->sk);
2509 		return answ;
2510 	}
2511 	switch (cmd) {
2512 	case SIOCINQ: /* same as FIONREAD */
2513 		if (smc->sk.sk_state == SMC_LISTEN) {
2514 			release_sock(&smc->sk);
2515 			return -EINVAL;
2516 		}
2517 		if (smc->sk.sk_state == SMC_INIT ||
2518 		    smc->sk.sk_state == SMC_CLOSED)
2519 			answ = 0;
2520 		else
2521 			answ = atomic_read(&smc->conn.bytes_to_rcv);
2522 		break;
2523 	case SIOCOUTQ:
2524 		/* output queue size (not send + not acked) */
2525 		if (smc->sk.sk_state == SMC_LISTEN) {
2526 			release_sock(&smc->sk);
2527 			return -EINVAL;
2528 		}
2529 		if (smc->sk.sk_state == SMC_INIT ||
2530 		    smc->sk.sk_state == SMC_CLOSED)
2531 			answ = 0;
2532 		else
2533 			answ = smc->conn.sndbuf_desc->len -
2534 					atomic_read(&smc->conn.sndbuf_space);
2535 		break;
2536 	case SIOCOUTQNSD:
2537 		/* output queue size (not send only) */
2538 		if (smc->sk.sk_state == SMC_LISTEN) {
2539 			release_sock(&smc->sk);
2540 			return -EINVAL;
2541 		}
2542 		if (smc->sk.sk_state == SMC_INIT ||
2543 		    smc->sk.sk_state == SMC_CLOSED)
2544 			answ = 0;
2545 		else
2546 			answ = smc_tx_prepared_sends(&smc->conn);
2547 		break;
2548 	case SIOCATMARK:
2549 		if (smc->sk.sk_state == SMC_LISTEN) {
2550 			release_sock(&smc->sk);
2551 			return -EINVAL;
2552 		}
2553 		if (smc->sk.sk_state == SMC_INIT ||
2554 		    smc->sk.sk_state == SMC_CLOSED) {
2555 			answ = 0;
2556 		} else {
2557 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
2558 			smc_curs_copy(&urg, &conn->urg_curs, conn);
2559 			answ = smc_curs_diff(conn->rmb_desc->len,
2560 					     &cons, &urg) == 1;
2561 		}
2562 		break;
2563 	default:
2564 		release_sock(&smc->sk);
2565 		return -ENOIOCTLCMD;
2566 	}
2567 	release_sock(&smc->sk);
2568 
2569 	return put_user(answ, (int __user *)arg);
2570 }
2571 
2572 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
2573 			    int offset, size_t size, int flags)
2574 {
2575 	struct sock *sk = sock->sk;
2576 	struct smc_sock *smc;
2577 	int rc = -EPIPE;
2578 
2579 	smc = smc_sk(sk);
2580 	lock_sock(sk);
2581 	if (sk->sk_state != SMC_ACTIVE) {
2582 		release_sock(sk);
2583 		goto out;
2584 	}
2585 	release_sock(sk);
2586 	if (smc->use_fallback) {
2587 		rc = kernel_sendpage(smc->clcsock, page, offset,
2588 				     size, flags);
2589 	} else {
2590 		SMC_STAT_INC(smc, sendpage_cnt);
2591 		rc = sock_no_sendpage(sock, page, offset, size, flags);
2592 	}
2593 
2594 out:
2595 	return rc;
2596 }
2597 
2598 /* Map the affected portions of the rmbe into an spd, note the number of bytes
2599  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
2600  * updates till whenever a respective page has been fully processed.
2601  * Note that subsequent recv() calls have to wait till all splice() processing
2602  * completed.
2603  */
2604 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
2605 			       struct pipe_inode_info *pipe, size_t len,
2606 			       unsigned int flags)
2607 {
2608 	struct sock *sk = sock->sk;
2609 	struct smc_sock *smc;
2610 	int rc = -ENOTCONN;
2611 
2612 	smc = smc_sk(sk);
2613 	lock_sock(sk);
2614 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2615 		/* socket was connected before, no more data to read */
2616 		rc = 0;
2617 		goto out;
2618 	}
2619 	if (sk->sk_state == SMC_INIT ||
2620 	    sk->sk_state == SMC_LISTEN ||
2621 	    sk->sk_state == SMC_CLOSED)
2622 		goto out;
2623 
2624 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2625 		rc = 0;
2626 		goto out;
2627 	}
2628 
2629 	if (smc->use_fallback) {
2630 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
2631 						    pipe, len, flags);
2632 	} else {
2633 		if (*ppos) {
2634 			rc = -ESPIPE;
2635 			goto out;
2636 		}
2637 		if (flags & SPLICE_F_NONBLOCK)
2638 			flags = MSG_DONTWAIT;
2639 		else
2640 			flags = 0;
2641 		SMC_STAT_INC(smc, splice_cnt);
2642 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
2643 	}
2644 out:
2645 	release_sock(sk);
2646 
2647 	return rc;
2648 }
2649 
2650 /* must look like tcp */
2651 static const struct proto_ops smc_sock_ops = {
2652 	.family		= PF_SMC,
2653 	.owner		= THIS_MODULE,
2654 	.release	= smc_release,
2655 	.bind		= smc_bind,
2656 	.connect	= smc_connect,
2657 	.socketpair	= sock_no_socketpair,
2658 	.accept		= smc_accept,
2659 	.getname	= smc_getname,
2660 	.poll		= smc_poll,
2661 	.ioctl		= smc_ioctl,
2662 	.listen		= smc_listen,
2663 	.shutdown	= smc_shutdown,
2664 	.setsockopt	= smc_setsockopt,
2665 	.getsockopt	= smc_getsockopt,
2666 	.sendmsg	= smc_sendmsg,
2667 	.recvmsg	= smc_recvmsg,
2668 	.mmap		= sock_no_mmap,
2669 	.sendpage	= smc_sendpage,
2670 	.splice_read	= smc_splice_read,
2671 };
2672 
2673 static int smc_create(struct net *net, struct socket *sock, int protocol,
2674 		      int kern)
2675 {
2676 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
2677 	struct smc_sock *smc;
2678 	struct sock *sk;
2679 	int rc;
2680 
2681 	rc = -ESOCKTNOSUPPORT;
2682 	if (sock->type != SOCK_STREAM)
2683 		goto out;
2684 
2685 	rc = -EPROTONOSUPPORT;
2686 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
2687 		goto out;
2688 
2689 	rc = -ENOBUFS;
2690 	sock->ops = &smc_sock_ops;
2691 	sk = smc_sock_alloc(net, sock, protocol);
2692 	if (!sk)
2693 		goto out;
2694 
2695 	/* create internal TCP socket for CLC handshake and fallback */
2696 	smc = smc_sk(sk);
2697 	smc->use_fallback = false; /* assume rdma capability first */
2698 	smc->fallback_rsn = 0;
2699 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
2700 			      &smc->clcsock);
2701 	if (rc) {
2702 		sk_common_release(sk);
2703 		goto out;
2704 	}
2705 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
2706 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
2707 
2708 out:
2709 	return rc;
2710 }
2711 
2712 static const struct net_proto_family smc_sock_family_ops = {
2713 	.family	= PF_SMC,
2714 	.owner	= THIS_MODULE,
2715 	.create	= smc_create,
2716 };
2717 
2718 unsigned int smc_net_id;
2719 
2720 static __net_init int smc_net_init(struct net *net)
2721 {
2722 	return smc_pnet_net_init(net);
2723 }
2724 
2725 static void __net_exit smc_net_exit(struct net *net)
2726 {
2727 	smc_pnet_net_exit(net);
2728 }
2729 
2730 static __net_init int smc_net_stat_init(struct net *net)
2731 {
2732 	return smc_stats_init(net);
2733 }
2734 
2735 static void __net_exit smc_net_stat_exit(struct net *net)
2736 {
2737 	smc_stats_exit(net);
2738 }
2739 
2740 static struct pernet_operations smc_net_ops = {
2741 	.init = smc_net_init,
2742 	.exit = smc_net_exit,
2743 	.id   = &smc_net_id,
2744 	.size = sizeof(struct smc_net),
2745 };
2746 
2747 static struct pernet_operations smc_net_stat_ops = {
2748 	.init = smc_net_stat_init,
2749 	.exit = smc_net_stat_exit,
2750 };
2751 
2752 static int __init smc_init(void)
2753 {
2754 	int rc;
2755 
2756 	rc = register_pernet_subsys(&smc_net_ops);
2757 	if (rc)
2758 		return rc;
2759 
2760 	rc = register_pernet_subsys(&smc_net_stat_ops);
2761 	if (rc)
2762 		return rc;
2763 
2764 	smc_ism_init();
2765 	smc_clc_init();
2766 
2767 	rc = smc_nl_init();
2768 	if (rc)
2769 		goto out_pernet_subsys;
2770 
2771 	rc = smc_pnet_init();
2772 	if (rc)
2773 		goto out_nl;
2774 
2775 	rc = -ENOMEM;
2776 	smc_hs_wq = alloc_workqueue("smc_hs_wq", 0, 0);
2777 	if (!smc_hs_wq)
2778 		goto out_pnet;
2779 
2780 	smc_close_wq = alloc_workqueue("smc_close_wq", 0, 0);
2781 	if (!smc_close_wq)
2782 		goto out_alloc_hs_wq;
2783 
2784 	rc = smc_core_init();
2785 	if (rc) {
2786 		pr_err("%s: smc_core_init fails with %d\n", __func__, rc);
2787 		goto out_alloc_wqs;
2788 	}
2789 
2790 	rc = smc_llc_init();
2791 	if (rc) {
2792 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
2793 		goto out_core;
2794 	}
2795 
2796 	rc = smc_cdc_init();
2797 	if (rc) {
2798 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
2799 		goto out_core;
2800 	}
2801 
2802 	rc = proto_register(&smc_proto, 1);
2803 	if (rc) {
2804 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
2805 		goto out_core;
2806 	}
2807 
2808 	rc = proto_register(&smc_proto6, 1);
2809 	if (rc) {
2810 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
2811 		goto out_proto;
2812 	}
2813 
2814 	rc = sock_register(&smc_sock_family_ops);
2815 	if (rc) {
2816 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
2817 		goto out_proto6;
2818 	}
2819 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
2820 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
2821 
2822 	rc = smc_ib_register_client();
2823 	if (rc) {
2824 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
2825 		goto out_sock;
2826 	}
2827 
2828 	static_branch_enable(&tcp_have_smc);
2829 	return 0;
2830 
2831 out_sock:
2832 	sock_unregister(PF_SMC);
2833 out_proto6:
2834 	proto_unregister(&smc_proto6);
2835 out_proto:
2836 	proto_unregister(&smc_proto);
2837 out_core:
2838 	smc_core_exit();
2839 out_alloc_wqs:
2840 	destroy_workqueue(smc_close_wq);
2841 out_alloc_hs_wq:
2842 	destroy_workqueue(smc_hs_wq);
2843 out_pnet:
2844 	smc_pnet_exit();
2845 out_nl:
2846 	smc_nl_exit();
2847 out_pernet_subsys:
2848 	unregister_pernet_subsys(&smc_net_ops);
2849 
2850 	return rc;
2851 }
2852 
2853 static void __exit smc_exit(void)
2854 {
2855 	static_branch_disable(&tcp_have_smc);
2856 	sock_unregister(PF_SMC);
2857 	smc_core_exit();
2858 	smc_ib_unregister_client();
2859 	destroy_workqueue(smc_close_wq);
2860 	destroy_workqueue(smc_hs_wq);
2861 	proto_unregister(&smc_proto6);
2862 	proto_unregister(&smc_proto);
2863 	smc_pnet_exit();
2864 	smc_nl_exit();
2865 	smc_clc_exit();
2866 	unregister_pernet_subsys(&smc_net_stat_ops);
2867 	unregister_pernet_subsys(&smc_net_ops);
2868 	rcu_barrier();
2869 }
2870 
2871 module_init(smc_init);
2872 module_exit(smc_exit);
2873 
2874 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
2875 MODULE_DESCRIPTION("smc socket address family");
2876 MODULE_LICENSE("GPL");
2877 MODULE_ALIAS_NETPROTO(PF_SMC);
2878