xref: /linux/net/smc/af_smc.c (revision b04df400c30235fa347313c9e2a0695549bd2c8e)
1 /*
2  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
3  *
4  *  AF_SMC protocol family socket handler keeping the AF_INET sock address type
5  *  applies to SOCK_STREAM sockets only
6  *  offers an alternative communication option for TCP-protocol sockets
7  *  applicable with RoCE-cards only
8  *
9  *  Initial restrictions:
10  *    - support for alternate links postponed
11  *    - partial support for non-blocking sockets only
12  *    - support for urgent data postponed
13  *
14  *  Copyright IBM Corp. 2016, 2018
15  *
16  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
17  *              based on prototype from Frank Blaschka
18  */
19 
20 #define KMSG_COMPONENT "smc"
21 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
22 
23 #include <linux/module.h>
24 #include <linux/socket.h>
25 #include <linux/workqueue.h>
26 #include <linux/in.h>
27 #include <linux/sched/signal.h>
28 
29 #include <net/sock.h>
30 #include <net/tcp.h>
31 #include <net/smc.h>
32 #include <asm/ioctls.h>
33 
34 #include "smc.h"
35 #include "smc_clc.h"
36 #include "smc_llc.h"
37 #include "smc_cdc.h"
38 #include "smc_core.h"
39 #include "smc_ib.h"
40 #include "smc_pnet.h"
41 #include "smc_tx.h"
42 #include "smc_rx.h"
43 #include "smc_close.h"
44 
45 static DEFINE_MUTEX(smc_create_lgr_pending);	/* serialize link group
46 						 * creation
47 						 */
48 
49 struct smc_lgr_list smc_lgr_list = {		/* established link groups */
50 	.lock = __SPIN_LOCK_UNLOCKED(smc_lgr_list.lock),
51 	.list = LIST_HEAD_INIT(smc_lgr_list.list),
52 };
53 
54 static void smc_tcp_listen_work(struct work_struct *);
55 
56 static void smc_set_keepalive(struct sock *sk, int val)
57 {
58 	struct smc_sock *smc = smc_sk(sk);
59 
60 	smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
61 }
62 
63 static struct smc_hashinfo smc_v4_hashinfo = {
64 	.lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
65 };
66 
67 static struct smc_hashinfo smc_v6_hashinfo = {
68 	.lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
69 };
70 
71 int smc_hash_sk(struct sock *sk)
72 {
73 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
74 	struct hlist_head *head;
75 
76 	head = &h->ht;
77 
78 	write_lock_bh(&h->lock);
79 	sk_add_node(sk, head);
80 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
81 	write_unlock_bh(&h->lock);
82 
83 	return 0;
84 }
85 EXPORT_SYMBOL_GPL(smc_hash_sk);
86 
87 void smc_unhash_sk(struct sock *sk)
88 {
89 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
90 
91 	write_lock_bh(&h->lock);
92 	if (sk_del_node_init(sk))
93 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
94 	write_unlock_bh(&h->lock);
95 }
96 EXPORT_SYMBOL_GPL(smc_unhash_sk);
97 
98 struct proto smc_proto = {
99 	.name		= "SMC",
100 	.owner		= THIS_MODULE,
101 	.keepalive	= smc_set_keepalive,
102 	.hash		= smc_hash_sk,
103 	.unhash		= smc_unhash_sk,
104 	.obj_size	= sizeof(struct smc_sock),
105 	.h.smc_hash	= &smc_v4_hashinfo,
106 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
107 };
108 EXPORT_SYMBOL_GPL(smc_proto);
109 
110 struct proto smc_proto6 = {
111 	.name		= "SMC6",
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_v6_hashinfo,
118 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
119 };
120 EXPORT_SYMBOL_GPL(smc_proto6);
121 
122 static int smc_release(struct socket *sock)
123 {
124 	struct sock *sk = sock->sk;
125 	struct smc_sock *smc;
126 	int rc = 0;
127 
128 	if (!sk)
129 		goto out;
130 
131 	smc = smc_sk(sk);
132 	if (sk->sk_state == SMC_LISTEN)
133 		/* smc_close_non_accepted() is called and acquires
134 		 * sock lock for child sockets again
135 		 */
136 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
137 	else
138 		lock_sock(sk);
139 
140 	if (!smc->use_fallback) {
141 		rc = smc_close_active(smc);
142 		sock_set_flag(sk, SOCK_DEAD);
143 		sk->sk_shutdown |= SHUTDOWN_MASK;
144 	}
145 	if (smc->clcsock) {
146 		sock_release(smc->clcsock);
147 		smc->clcsock = NULL;
148 	}
149 	if (smc->use_fallback) {
150 		sock_put(sk); /* passive closing */
151 		sk->sk_state = SMC_CLOSED;
152 		sk->sk_state_change(sk);
153 	}
154 
155 	/* detach socket */
156 	sock_orphan(sk);
157 	sock->sk = NULL;
158 	if (!smc->use_fallback && sk->sk_state == SMC_CLOSED)
159 		smc_conn_free(&smc->conn);
160 	release_sock(sk);
161 
162 	sk->sk_prot->unhash(sk);
163 	sock_put(sk); /* final sock_put */
164 out:
165 	return rc;
166 }
167 
168 static void smc_destruct(struct sock *sk)
169 {
170 	if (sk->sk_state != SMC_CLOSED)
171 		return;
172 	if (!sock_flag(sk, SOCK_DEAD))
173 		return;
174 
175 	sk_refcnt_debug_dec(sk);
176 }
177 
178 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
179 				   int protocol)
180 {
181 	struct smc_sock *smc;
182 	struct proto *prot;
183 	struct sock *sk;
184 
185 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
186 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
187 	if (!sk)
188 		return NULL;
189 
190 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
191 	sk->sk_state = SMC_INIT;
192 	sk->sk_destruct = smc_destruct;
193 	sk->sk_protocol = protocol;
194 	smc = smc_sk(sk);
195 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
196 	INIT_LIST_HEAD(&smc->accept_q);
197 	spin_lock_init(&smc->accept_q_lock);
198 	sk->sk_prot->hash(sk);
199 	sk_refcnt_debug_inc(sk);
200 
201 	return sk;
202 }
203 
204 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
205 		    int addr_len)
206 {
207 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
208 	struct sock *sk = sock->sk;
209 	struct smc_sock *smc;
210 	int rc;
211 
212 	smc = smc_sk(sk);
213 
214 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
215 	rc = -EINVAL;
216 	if (addr_len < sizeof(struct sockaddr_in))
217 		goto out;
218 
219 	rc = -EAFNOSUPPORT;
220 	if (addr->sin_family != AF_INET &&
221 	    addr->sin_family != AF_INET6 &&
222 	    addr->sin_family != AF_UNSPEC)
223 		goto out;
224 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
225 	if (addr->sin_family == AF_UNSPEC &&
226 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
227 		goto out;
228 
229 	lock_sock(sk);
230 
231 	/* Check if socket is already active */
232 	rc = -EINVAL;
233 	if (sk->sk_state != SMC_INIT)
234 		goto out_rel;
235 
236 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
237 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
238 
239 out_rel:
240 	release_sock(sk);
241 out:
242 	return rc;
243 }
244 
245 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
246 				   unsigned long mask)
247 {
248 	/* options we don't get control via setsockopt for */
249 	nsk->sk_type = osk->sk_type;
250 	nsk->sk_sndbuf = osk->sk_sndbuf;
251 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
252 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
253 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
254 	nsk->sk_mark = osk->sk_mark;
255 	nsk->sk_priority = osk->sk_priority;
256 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
257 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
258 	nsk->sk_err = osk->sk_err;
259 
260 	nsk->sk_flags &= ~mask;
261 	nsk->sk_flags |= osk->sk_flags & mask;
262 }
263 
264 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
265 			     (1UL << SOCK_KEEPOPEN) | \
266 			     (1UL << SOCK_LINGER) | \
267 			     (1UL << SOCK_BROADCAST) | \
268 			     (1UL << SOCK_TIMESTAMP) | \
269 			     (1UL << SOCK_DBG) | \
270 			     (1UL << SOCK_RCVTSTAMP) | \
271 			     (1UL << SOCK_RCVTSTAMPNS) | \
272 			     (1UL << SOCK_LOCALROUTE) | \
273 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
274 			     (1UL << SOCK_RXQ_OVFL) | \
275 			     (1UL << SOCK_WIFI_STATUS) | \
276 			     (1UL << SOCK_NOFCS) | \
277 			     (1UL << SOCK_FILTER_LOCKED))
278 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
279  * clc socket (since smc is not called for these options from net/core)
280  */
281 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
282 {
283 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
284 }
285 
286 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
287 			     (1UL << SOCK_KEEPOPEN) | \
288 			     (1UL << SOCK_LINGER) | \
289 			     (1UL << SOCK_DBG))
290 /* copy only settings and flags relevant for smc from clc to smc socket */
291 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
292 {
293 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
294 }
295 
296 /* register a new rmb, optionally send confirm_rkey msg to register with peer */
297 static int smc_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc,
298 		       bool conf_rkey)
299 {
300 	/* register memory region for new rmb */
301 	if (smc_wr_reg_send(link, rmb_desc->mr_rx[SMC_SINGLE_LINK])) {
302 		rmb_desc->regerr = 1;
303 		return -EFAULT;
304 	}
305 	if (!conf_rkey)
306 		return 0;
307 	/* exchange confirm_rkey msg with peer */
308 	if (smc_llc_do_confirm_rkey(link, rmb_desc)) {
309 		rmb_desc->regerr = 1;
310 		return -EFAULT;
311 	}
312 	return 0;
313 }
314 
315 static int smc_clnt_conf_first_link(struct smc_sock *smc)
316 {
317 	struct net *net = sock_net(smc->clcsock->sk);
318 	struct smc_link_group *lgr = smc->conn.lgr;
319 	struct smc_link *link;
320 	int rest;
321 	int rc;
322 
323 	link = &lgr->lnk[SMC_SINGLE_LINK];
324 	/* receive CONFIRM LINK request from server over RoCE fabric */
325 	rest = wait_for_completion_interruptible_timeout(
326 		&link->llc_confirm,
327 		SMC_LLC_WAIT_FIRST_TIME);
328 	if (rest <= 0) {
329 		struct smc_clc_msg_decline dclc;
330 
331 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
332 				      SMC_CLC_DECLINE);
333 		return rc;
334 	}
335 
336 	if (link->llc_confirm_rc)
337 		return SMC_CLC_DECL_RMBE_EC;
338 
339 	rc = smc_ib_modify_qp_rts(link);
340 	if (rc)
341 		return SMC_CLC_DECL_INTERR;
342 
343 	smc_wr_remember_qp_attr(link);
344 
345 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
346 		return SMC_CLC_DECL_INTERR;
347 
348 	/* send CONFIRM LINK response over RoCE fabric */
349 	rc = smc_llc_send_confirm_link(link,
350 				       link->smcibdev->mac[link->ibport - 1],
351 				       &link->smcibdev->gid[link->ibport - 1],
352 				       SMC_LLC_RESP);
353 	if (rc < 0)
354 		return SMC_CLC_DECL_TCL;
355 
356 	/* receive ADD LINK request from server over RoCE fabric */
357 	rest = wait_for_completion_interruptible_timeout(&link->llc_add,
358 							 SMC_LLC_WAIT_TIME);
359 	if (rest <= 0) {
360 		struct smc_clc_msg_decline dclc;
361 
362 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
363 				      SMC_CLC_DECLINE);
364 		return rc;
365 	}
366 
367 	/* send add link reject message, only one link supported for now */
368 	rc = smc_llc_send_add_link(link,
369 				   link->smcibdev->mac[link->ibport - 1],
370 				   &link->smcibdev->gid[link->ibport - 1],
371 				   SMC_LLC_RESP);
372 	if (rc < 0)
373 		return SMC_CLC_DECL_TCL;
374 
375 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
376 
377 	return 0;
378 }
379 
380 static void smc_conn_save_peer_info(struct smc_sock *smc,
381 				    struct smc_clc_msg_accept_confirm *clc)
382 {
383 	smc->conn.peer_conn_idx = clc->conn_idx;
384 	smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
385 	smc->conn.peer_rmbe_size = smc_uncompress_bufsize(clc->rmbe_size);
386 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
387 }
388 
389 static void smc_link_save_peer_info(struct smc_link *link,
390 				    struct smc_clc_msg_accept_confirm *clc)
391 {
392 	link->peer_qpn = ntoh24(clc->qpn);
393 	memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
394 	memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
395 	link->peer_psn = ntoh24(clc->psn);
396 	link->peer_mtu = clc->qp_mtu;
397 }
398 
399 /* setup for RDMA connection of client */
400 static int smc_connect_rdma(struct smc_sock *smc)
401 {
402 	struct smc_clc_msg_accept_confirm aclc;
403 	int local_contact = SMC_FIRST_CONTACT;
404 	struct smc_ib_device *smcibdev;
405 	struct smc_link *link;
406 	u8 srv_first_contact;
407 	int reason_code = 0;
408 	int rc = 0;
409 	u8 ibport;
410 
411 	sock_hold(&smc->sk); /* sock put in passive closing */
412 
413 	if (smc->use_fallback)
414 		goto out_connected;
415 
416 	if (!tcp_sk(smc->clcsock->sk)->syn_smc) {
417 		/* peer has not signalled SMC-capability */
418 		smc->use_fallback = true;
419 		goto out_connected;
420 	}
421 
422 	/* IPSec connections opt out of SMC-R optimizations */
423 	if (using_ipsec(smc)) {
424 		reason_code = SMC_CLC_DECL_IPSEC;
425 		goto decline_rdma;
426 	}
427 
428 	/* PNET table look up: search active ib_device and port
429 	 * within same PNETID that also contains the ethernet device
430 	 * used for the internal TCP socket
431 	 */
432 	smc_pnet_find_roce_resource(smc->clcsock->sk, &smcibdev, &ibport);
433 	if (!smcibdev) {
434 		reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
435 		goto decline_rdma;
436 	}
437 
438 	/* do inband token exchange */
439 	reason_code = smc_clc_send_proposal(smc, smcibdev, ibport);
440 	if (reason_code < 0) {
441 		rc = reason_code;
442 		goto out_err;
443 	}
444 	if (reason_code > 0) /* configuration error */
445 		goto decline_rdma;
446 	/* receive SMC Accept CLC message */
447 	reason_code = smc_clc_wait_msg(smc, &aclc, sizeof(aclc),
448 				       SMC_CLC_ACCEPT);
449 	if (reason_code < 0) {
450 		rc = reason_code;
451 		goto out_err;
452 	}
453 	if (reason_code > 0)
454 		goto decline_rdma;
455 
456 	srv_first_contact = aclc.hdr.flag;
457 	mutex_lock(&smc_create_lgr_pending);
458 	local_contact = smc_conn_create(smc, smcibdev, ibport, &aclc.lcl,
459 					srv_first_contact);
460 	if (local_contact < 0) {
461 		rc = local_contact;
462 		if (rc == -ENOMEM)
463 			reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
464 		else if (rc == -ENOLINK)
465 			reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
466 		else
467 			reason_code = SMC_CLC_DECL_INTERR; /* other error */
468 		goto decline_rdma_unlock;
469 	}
470 	link = &smc->conn.lgr->lnk[SMC_SINGLE_LINK];
471 
472 	smc_conn_save_peer_info(smc, &aclc);
473 
474 	/* create send buffer and rmb */
475 	rc = smc_buf_create(smc);
476 	if (rc) {
477 		reason_code = SMC_CLC_DECL_MEM;
478 		goto decline_rdma_unlock;
479 	}
480 
481 	if (local_contact == SMC_FIRST_CONTACT)
482 		smc_link_save_peer_info(link, &aclc);
483 
484 	rc = smc_rmb_rtoken_handling(&smc->conn, &aclc);
485 	if (rc) {
486 		reason_code = SMC_CLC_DECL_INTERR;
487 		goto decline_rdma_unlock;
488 	}
489 
490 	smc_close_init(smc);
491 	smc_rx_init(smc);
492 
493 	if (local_contact == SMC_FIRST_CONTACT) {
494 		rc = smc_ib_ready_link(link);
495 		if (rc) {
496 			reason_code = SMC_CLC_DECL_INTERR;
497 			goto decline_rdma_unlock;
498 		}
499 	} else {
500 		if (!smc->conn.rmb_desc->reused) {
501 			if (smc_reg_rmb(link, smc->conn.rmb_desc, true)) {
502 				reason_code = SMC_CLC_DECL_INTERR;
503 				goto decline_rdma_unlock;
504 			}
505 		}
506 	}
507 	smc_rmb_sync_sg_for_device(&smc->conn);
508 
509 	rc = smc_clc_send_confirm(smc);
510 	if (rc)
511 		goto out_err_unlock;
512 
513 	if (local_contact == SMC_FIRST_CONTACT) {
514 		/* QP confirmation over RoCE fabric */
515 		reason_code = smc_clnt_conf_first_link(smc);
516 		if (reason_code < 0) {
517 			rc = reason_code;
518 			goto out_err_unlock;
519 		}
520 		if (reason_code > 0)
521 			goto decline_rdma_unlock;
522 	}
523 
524 	mutex_unlock(&smc_create_lgr_pending);
525 	smc_tx_init(smc);
526 
527 out_connected:
528 	smc_copy_sock_settings_to_clc(smc);
529 	if (smc->sk.sk_state == SMC_INIT)
530 		smc->sk.sk_state = SMC_ACTIVE;
531 
532 	return rc ? rc : local_contact;
533 
534 decline_rdma_unlock:
535 	if (local_contact == SMC_FIRST_CONTACT)
536 		smc_lgr_forget(smc->conn.lgr);
537 	mutex_unlock(&smc_create_lgr_pending);
538 	smc_conn_free(&smc->conn);
539 decline_rdma:
540 	/* RDMA setup failed, switch back to TCP */
541 	smc->use_fallback = true;
542 	if (reason_code && (reason_code != SMC_CLC_DECL_REPLY)) {
543 		rc = smc_clc_send_decline(smc, reason_code);
544 		if (rc < 0)
545 			goto out_err;
546 	}
547 	goto out_connected;
548 
549 out_err_unlock:
550 	if (local_contact == SMC_FIRST_CONTACT)
551 		smc_lgr_forget(smc->conn.lgr);
552 	mutex_unlock(&smc_create_lgr_pending);
553 	smc_conn_free(&smc->conn);
554 out_err:
555 	if (smc->sk.sk_state == SMC_INIT)
556 		sock_put(&smc->sk); /* passive closing */
557 	return rc;
558 }
559 
560 static int smc_connect(struct socket *sock, struct sockaddr *addr,
561 		       int alen, int flags)
562 {
563 	struct sock *sk = sock->sk;
564 	struct smc_sock *smc;
565 	int rc = -EINVAL;
566 
567 	smc = smc_sk(sk);
568 
569 	/* separate smc parameter checking to be safe */
570 	if (alen < sizeof(addr->sa_family))
571 		goto out_err;
572 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
573 		goto out_err;
574 
575 	lock_sock(sk);
576 	switch (sk->sk_state) {
577 	default:
578 		goto out;
579 	case SMC_ACTIVE:
580 		rc = -EISCONN;
581 		goto out;
582 	case SMC_INIT:
583 		rc = 0;
584 		break;
585 	}
586 
587 	smc_copy_sock_settings_to_clc(smc);
588 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
589 	rc = kernel_connect(smc->clcsock, addr, alen, flags);
590 	if (rc)
591 		goto out;
592 
593 	/* setup RDMA connection */
594 	rc = smc_connect_rdma(smc);
595 	if (rc < 0)
596 		goto out;
597 	else
598 		rc = 0; /* success cases including fallback */
599 
600 out:
601 	release_sock(sk);
602 out_err:
603 	return rc;
604 }
605 
606 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
607 {
608 	struct socket *new_clcsock = NULL;
609 	struct sock *lsk = &lsmc->sk;
610 	struct sock *new_sk;
611 	int rc;
612 
613 	release_sock(lsk);
614 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
615 	if (!new_sk) {
616 		rc = -ENOMEM;
617 		lsk->sk_err = ENOMEM;
618 		*new_smc = NULL;
619 		lock_sock(lsk);
620 		goto out;
621 	}
622 	*new_smc = smc_sk(new_sk);
623 
624 	rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
625 	lock_sock(lsk);
626 	if  (rc < 0)
627 		lsk->sk_err = -rc;
628 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
629 		if (new_clcsock)
630 			sock_release(new_clcsock);
631 		new_sk->sk_state = SMC_CLOSED;
632 		sock_set_flag(new_sk, SOCK_DEAD);
633 		new_sk->sk_prot->unhash(new_sk);
634 		sock_put(new_sk); /* final */
635 		*new_smc = NULL;
636 		goto out;
637 	}
638 
639 	(*new_smc)->clcsock = new_clcsock;
640 out:
641 	return rc;
642 }
643 
644 /* add a just created sock to the accept queue of the listen sock as
645  * candidate for a following socket accept call from user space
646  */
647 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
648 {
649 	struct smc_sock *par = smc_sk(parent);
650 
651 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
652 	spin_lock(&par->accept_q_lock);
653 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
654 	spin_unlock(&par->accept_q_lock);
655 	sk_acceptq_added(parent);
656 }
657 
658 /* remove a socket from the accept queue of its parental listening socket */
659 static void smc_accept_unlink(struct sock *sk)
660 {
661 	struct smc_sock *par = smc_sk(sk)->listen_smc;
662 
663 	spin_lock(&par->accept_q_lock);
664 	list_del_init(&smc_sk(sk)->accept_q);
665 	spin_unlock(&par->accept_q_lock);
666 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
667 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
668 }
669 
670 /* remove a sock from the accept queue to bind it to a new socket created
671  * for a socket accept call from user space
672  */
673 struct sock *smc_accept_dequeue(struct sock *parent,
674 				struct socket *new_sock)
675 {
676 	struct smc_sock *isk, *n;
677 	struct sock *new_sk;
678 
679 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
680 		new_sk = (struct sock *)isk;
681 
682 		smc_accept_unlink(new_sk);
683 		if (new_sk->sk_state == SMC_CLOSED) {
684 			if (isk->clcsock) {
685 				sock_release(isk->clcsock);
686 				isk->clcsock = NULL;
687 			}
688 			new_sk->sk_prot->unhash(new_sk);
689 			sock_put(new_sk); /* final */
690 			continue;
691 		}
692 		if (new_sock)
693 			sock_graft(new_sk, new_sock);
694 		return new_sk;
695 	}
696 	return NULL;
697 }
698 
699 /* clean up for a created but never accepted sock */
700 void smc_close_non_accepted(struct sock *sk)
701 {
702 	struct smc_sock *smc = smc_sk(sk);
703 
704 	lock_sock(sk);
705 	if (!sk->sk_lingertime)
706 		/* wait for peer closing */
707 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
708 	if (!smc->use_fallback) {
709 		smc_close_active(smc);
710 		sock_set_flag(sk, SOCK_DEAD);
711 		sk->sk_shutdown |= SHUTDOWN_MASK;
712 	}
713 	if (smc->clcsock) {
714 		struct socket *tcp;
715 
716 		tcp = smc->clcsock;
717 		smc->clcsock = NULL;
718 		sock_release(tcp);
719 	}
720 	if (smc->use_fallback) {
721 		sock_put(sk); /* passive closing */
722 		sk->sk_state = SMC_CLOSED;
723 	} else {
724 		if (sk->sk_state == SMC_CLOSED)
725 			smc_conn_free(&smc->conn);
726 	}
727 	release_sock(sk);
728 	sk->sk_prot->unhash(sk);
729 	sock_put(sk); /* final sock_put */
730 }
731 
732 static int smc_serv_conf_first_link(struct smc_sock *smc)
733 {
734 	struct net *net = sock_net(smc->clcsock->sk);
735 	struct smc_link_group *lgr = smc->conn.lgr;
736 	struct smc_link *link;
737 	int rest;
738 	int rc;
739 
740 	link = &lgr->lnk[SMC_SINGLE_LINK];
741 
742 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
743 		return SMC_CLC_DECL_INTERR;
744 
745 	/* send CONFIRM LINK request to client over the RoCE fabric */
746 	rc = smc_llc_send_confirm_link(link,
747 				       link->smcibdev->mac[link->ibport - 1],
748 				       &link->smcibdev->gid[link->ibport - 1],
749 				       SMC_LLC_REQ);
750 	if (rc < 0)
751 		return SMC_CLC_DECL_TCL;
752 
753 	/* receive CONFIRM LINK response from client over the RoCE fabric */
754 	rest = wait_for_completion_interruptible_timeout(
755 		&link->llc_confirm_resp,
756 		SMC_LLC_WAIT_FIRST_TIME);
757 	if (rest <= 0) {
758 		struct smc_clc_msg_decline dclc;
759 
760 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
761 				      SMC_CLC_DECLINE);
762 		return rc;
763 	}
764 
765 	if (link->llc_confirm_resp_rc)
766 		return SMC_CLC_DECL_RMBE_EC;
767 
768 	/* send ADD LINK request to client over the RoCE fabric */
769 	rc = smc_llc_send_add_link(link,
770 				   link->smcibdev->mac[link->ibport - 1],
771 				   &link->smcibdev->gid[link->ibport - 1],
772 				   SMC_LLC_REQ);
773 	if (rc < 0)
774 		return SMC_CLC_DECL_TCL;
775 
776 	/* receive ADD LINK response from client over the RoCE fabric */
777 	rest = wait_for_completion_interruptible_timeout(&link->llc_add_resp,
778 							 SMC_LLC_WAIT_TIME);
779 	if (rest <= 0) {
780 		struct smc_clc_msg_decline dclc;
781 
782 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
783 				      SMC_CLC_DECLINE);
784 		return rc;
785 	}
786 
787 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
788 
789 	return 0;
790 }
791 
792 /* setup for RDMA connection of server */
793 static void smc_listen_work(struct work_struct *work)
794 {
795 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
796 						smc_listen_work);
797 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
798 	struct socket *newclcsock = new_smc->clcsock;
799 	struct smc_sock *lsmc = new_smc->listen_smc;
800 	struct smc_clc_msg_accept_confirm cclc;
801 	int local_contact = SMC_REUSE_CONTACT;
802 	struct sock *newsmcsk = &new_smc->sk;
803 	struct smc_clc_msg_proposal *pclc;
804 	struct smc_ib_device *smcibdev;
805 	u8 buf[SMC_CLC_MAX_LEN];
806 	struct smc_link *link;
807 	int reason_code = 0;
808 	int rc = 0;
809 	u8 ibport;
810 
811 	if (new_smc->use_fallback)
812 		goto out_connected;
813 
814 	/* check if peer is smc capable */
815 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
816 		new_smc->use_fallback = true;
817 		goto out_connected;
818 	}
819 
820 	/* do inband token exchange -
821 	 *wait for and receive SMC Proposal CLC message
822 	 */
823 	reason_code = smc_clc_wait_msg(new_smc, &buf, sizeof(buf),
824 				       SMC_CLC_PROPOSAL);
825 	if (reason_code < 0)
826 		goto out_err;
827 	if (reason_code > 0)
828 		goto decline_rdma;
829 
830 	/* IPSec connections opt out of SMC-R optimizations */
831 	if (using_ipsec(new_smc)) {
832 		reason_code = SMC_CLC_DECL_IPSEC;
833 		goto decline_rdma;
834 	}
835 
836 	/* PNET table look up: search active ib_device and port
837 	 * within same PNETID that also contains the ethernet device
838 	 * used for the internal TCP socket
839 	 */
840 	smc_pnet_find_roce_resource(newclcsock->sk, &smcibdev, &ibport);
841 	if (!smcibdev) {
842 		reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
843 		goto decline_rdma;
844 	}
845 
846 	pclc = (struct smc_clc_msg_proposal *)&buf;
847 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
848 
849 	rc = smc_clc_prfx_match(newclcsock, pclc_prfx);
850 	if (rc) {
851 		reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
852 		goto decline_rdma;
853 	}
854 
855 	/* allocate connection / link group */
856 	mutex_lock(&smc_create_lgr_pending);
857 	local_contact = smc_conn_create(new_smc, smcibdev, ibport, &pclc->lcl,
858 					0);
859 	if (local_contact < 0) {
860 		rc = local_contact;
861 		if (rc == -ENOMEM)
862 			reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
863 		goto decline_rdma_unlock;
864 	}
865 	link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
866 
867 	/* create send buffer and rmb */
868 	rc = smc_buf_create(new_smc);
869 	if (rc) {
870 		reason_code = SMC_CLC_DECL_MEM;
871 		goto decline_rdma_unlock;
872 	}
873 
874 	smc_close_init(new_smc);
875 	smc_rx_init(new_smc);
876 
877 	if (local_contact != SMC_FIRST_CONTACT) {
878 		if (!new_smc->conn.rmb_desc->reused) {
879 			if (smc_reg_rmb(link, new_smc->conn.rmb_desc, true)) {
880 				reason_code = SMC_CLC_DECL_INTERR;
881 				goto decline_rdma_unlock;
882 			}
883 		}
884 	}
885 	smc_rmb_sync_sg_for_device(&new_smc->conn);
886 
887 	rc = smc_clc_send_accept(new_smc, local_contact);
888 	if (rc)
889 		goto out_err_unlock;
890 
891 	/* receive SMC Confirm CLC message */
892 	reason_code = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
893 				       SMC_CLC_CONFIRM);
894 	if (reason_code < 0)
895 		goto out_err_unlock;
896 	if (reason_code > 0)
897 		goto decline_rdma_unlock;
898 	smc_conn_save_peer_info(new_smc, &cclc);
899 	if (local_contact == SMC_FIRST_CONTACT)
900 		smc_link_save_peer_info(link, &cclc);
901 
902 	rc = smc_rmb_rtoken_handling(&new_smc->conn, &cclc);
903 	if (rc) {
904 		reason_code = SMC_CLC_DECL_INTERR;
905 		goto decline_rdma_unlock;
906 	}
907 
908 	if (local_contact == SMC_FIRST_CONTACT) {
909 		rc = smc_ib_ready_link(link);
910 		if (rc) {
911 			reason_code = SMC_CLC_DECL_INTERR;
912 			goto decline_rdma_unlock;
913 		}
914 		/* QP confirmation over RoCE fabric */
915 		reason_code = smc_serv_conf_first_link(new_smc);
916 		if (reason_code < 0)
917 			/* peer is not aware of a problem */
918 			goto out_err_unlock;
919 		if (reason_code > 0)
920 			goto decline_rdma_unlock;
921 	}
922 
923 	smc_tx_init(new_smc);
924 	mutex_unlock(&smc_create_lgr_pending);
925 
926 out_connected:
927 	sk_refcnt_debug_inc(newsmcsk);
928 	if (newsmcsk->sk_state == SMC_INIT)
929 		newsmcsk->sk_state = SMC_ACTIVE;
930 enqueue:
931 	lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
932 	if (lsmc->sk.sk_state == SMC_LISTEN) {
933 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
934 	} else { /* no longer listening */
935 		smc_close_non_accepted(newsmcsk);
936 	}
937 	release_sock(&lsmc->sk);
938 
939 	/* Wake up accept */
940 	lsmc->sk.sk_data_ready(&lsmc->sk);
941 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
942 	return;
943 
944 decline_rdma_unlock:
945 	if (local_contact == SMC_FIRST_CONTACT)
946 		smc_lgr_forget(new_smc->conn.lgr);
947 	mutex_unlock(&smc_create_lgr_pending);
948 decline_rdma:
949 	/* RDMA setup failed, switch back to TCP */
950 	smc_conn_free(&new_smc->conn);
951 	new_smc->use_fallback = true;
952 	if (reason_code && (reason_code != SMC_CLC_DECL_REPLY)) {
953 		if (smc_clc_send_decline(new_smc, reason_code) < 0)
954 			goto out_err;
955 	}
956 	goto out_connected;
957 
958 out_err_unlock:
959 	if (local_contact == SMC_FIRST_CONTACT)
960 		smc_lgr_forget(new_smc->conn.lgr);
961 	mutex_unlock(&smc_create_lgr_pending);
962 out_err:
963 	if (newsmcsk->sk_state == SMC_INIT)
964 		sock_put(&new_smc->sk); /* passive closing */
965 	newsmcsk->sk_state = SMC_CLOSED;
966 	smc_conn_free(&new_smc->conn);
967 	goto enqueue; /* queue new sock with sk_err set */
968 }
969 
970 static void smc_tcp_listen_work(struct work_struct *work)
971 {
972 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
973 					     tcp_listen_work);
974 	struct sock *lsk = &lsmc->sk;
975 	struct smc_sock *new_smc;
976 	int rc = 0;
977 
978 	lock_sock(lsk);
979 	while (lsk->sk_state == SMC_LISTEN) {
980 		rc = smc_clcsock_accept(lsmc, &new_smc);
981 		if (rc)
982 			goto out;
983 		if (!new_smc)
984 			continue;
985 
986 		new_smc->listen_smc = lsmc;
987 		new_smc->use_fallback = lsmc->use_fallback;
988 		sock_hold(lsk); /* sock_put in smc_listen_work */
989 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
990 		smc_copy_sock_settings_to_smc(new_smc);
991 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
992 		if (!schedule_work(&new_smc->smc_listen_work))
993 			sock_put(&new_smc->sk);
994 	}
995 
996 out:
997 	release_sock(lsk);
998 	sock_put(&lsmc->sk); /* sock_hold in smc_listen */
999 }
1000 
1001 static int smc_listen(struct socket *sock, int backlog)
1002 {
1003 	struct sock *sk = sock->sk;
1004 	struct smc_sock *smc;
1005 	int rc;
1006 
1007 	smc = smc_sk(sk);
1008 	lock_sock(sk);
1009 
1010 	rc = -EINVAL;
1011 	if ((sk->sk_state != SMC_INIT) && (sk->sk_state != SMC_LISTEN))
1012 		goto out;
1013 
1014 	rc = 0;
1015 	if (sk->sk_state == SMC_LISTEN) {
1016 		sk->sk_max_ack_backlog = backlog;
1017 		goto out;
1018 	}
1019 	/* some socket options are handled in core, so we could not apply
1020 	 * them to the clc socket -- copy smc socket options to clc socket
1021 	 */
1022 	smc_copy_sock_settings_to_clc(smc);
1023 	if (!smc->use_fallback)
1024 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1025 
1026 	rc = kernel_listen(smc->clcsock, backlog);
1027 	if (rc)
1028 		goto out;
1029 	sk->sk_max_ack_backlog = backlog;
1030 	sk->sk_ack_backlog = 0;
1031 	sk->sk_state = SMC_LISTEN;
1032 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
1033 	sock_hold(sk); /* sock_hold in tcp_listen_worker */
1034 	if (!schedule_work(&smc->tcp_listen_work))
1035 		sock_put(sk);
1036 
1037 out:
1038 	release_sock(sk);
1039 	return rc;
1040 }
1041 
1042 static int smc_accept(struct socket *sock, struct socket *new_sock,
1043 		      int flags, bool kern)
1044 {
1045 	struct sock *sk = sock->sk, *nsk;
1046 	DECLARE_WAITQUEUE(wait, current);
1047 	struct smc_sock *lsmc;
1048 	long timeo;
1049 	int rc = 0;
1050 
1051 	lsmc = smc_sk(sk);
1052 	sock_hold(sk); /* sock_put below */
1053 	lock_sock(sk);
1054 
1055 	if (lsmc->sk.sk_state != SMC_LISTEN) {
1056 		rc = -EINVAL;
1057 		release_sock(sk);
1058 		goto out;
1059 	}
1060 
1061 	/* Wait for an incoming connection */
1062 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1063 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
1064 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1065 		set_current_state(TASK_INTERRUPTIBLE);
1066 		if (!timeo) {
1067 			rc = -EAGAIN;
1068 			break;
1069 		}
1070 		release_sock(sk);
1071 		timeo = schedule_timeout(timeo);
1072 		/* wakeup by sk_data_ready in smc_listen_work() */
1073 		sched_annotate_sleep();
1074 		lock_sock(sk);
1075 		if (signal_pending(current)) {
1076 			rc = sock_intr_errno(timeo);
1077 			break;
1078 		}
1079 	}
1080 	set_current_state(TASK_RUNNING);
1081 	remove_wait_queue(sk_sleep(sk), &wait);
1082 
1083 	if (!rc)
1084 		rc = sock_error(nsk);
1085 	release_sock(sk);
1086 	if (rc)
1087 		goto out;
1088 
1089 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
1090 		/* wait till data arrives on the socket */
1091 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
1092 								MSEC_PER_SEC);
1093 		if (smc_sk(nsk)->use_fallback) {
1094 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
1095 
1096 			lock_sock(clcsk);
1097 			if (skb_queue_empty(&clcsk->sk_receive_queue))
1098 				sk_wait_data(clcsk, &timeo, NULL);
1099 			release_sock(clcsk);
1100 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
1101 			lock_sock(nsk);
1102 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
1103 			release_sock(nsk);
1104 		}
1105 	}
1106 
1107 out:
1108 	sock_put(sk); /* sock_hold above */
1109 	return rc;
1110 }
1111 
1112 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1113 		       int peer)
1114 {
1115 	struct smc_sock *smc;
1116 
1117 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
1118 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
1119 		return -ENOTCONN;
1120 
1121 	smc = smc_sk(sock->sk);
1122 
1123 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
1124 }
1125 
1126 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1127 {
1128 	struct sock *sk = sock->sk;
1129 	struct smc_sock *smc;
1130 	int rc = -EPIPE;
1131 
1132 	smc = smc_sk(sk);
1133 	lock_sock(sk);
1134 	if ((sk->sk_state != SMC_ACTIVE) &&
1135 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1136 	    (sk->sk_state != SMC_INIT))
1137 		goto out;
1138 
1139 	if (msg->msg_flags & MSG_FASTOPEN) {
1140 		if (sk->sk_state == SMC_INIT) {
1141 			smc->use_fallback = true;
1142 		} else {
1143 			rc = -EINVAL;
1144 			goto out;
1145 		}
1146 	}
1147 
1148 	if (smc->use_fallback)
1149 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
1150 	else
1151 		rc = smc_tx_sendmsg(smc, msg, len);
1152 out:
1153 	release_sock(sk);
1154 	return rc;
1155 }
1156 
1157 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1158 		       int flags)
1159 {
1160 	struct sock *sk = sock->sk;
1161 	struct smc_sock *smc;
1162 	int rc = -ENOTCONN;
1163 
1164 	smc = smc_sk(sk);
1165 	lock_sock(sk);
1166 	if ((sk->sk_state == SMC_INIT) ||
1167 	    (sk->sk_state == SMC_LISTEN) ||
1168 	    (sk->sk_state == SMC_CLOSED))
1169 		goto out;
1170 
1171 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1172 		rc = 0;
1173 		goto out;
1174 	}
1175 
1176 	if (smc->use_fallback) {
1177 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
1178 	} else {
1179 		msg->msg_namelen = 0;
1180 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
1181 	}
1182 
1183 out:
1184 	release_sock(sk);
1185 	return rc;
1186 }
1187 
1188 static __poll_t smc_accept_poll(struct sock *parent)
1189 {
1190 	struct smc_sock *isk = smc_sk(parent);
1191 	__poll_t mask = 0;
1192 
1193 	spin_lock(&isk->accept_q_lock);
1194 	if (!list_empty(&isk->accept_q))
1195 		mask = EPOLLIN | EPOLLRDNORM;
1196 	spin_unlock(&isk->accept_q_lock);
1197 
1198 	return mask;
1199 }
1200 
1201 static __poll_t smc_poll(struct file *file, struct socket *sock,
1202 			     poll_table *wait)
1203 {
1204 	struct sock *sk = sock->sk;
1205 	__poll_t mask = 0;
1206 	struct smc_sock *smc;
1207 	int rc;
1208 
1209 	if (!sk)
1210 		return EPOLLNVAL;
1211 
1212 	smc = smc_sk(sock->sk);
1213 	sock_hold(sk);
1214 	lock_sock(sk);
1215 	if ((sk->sk_state == SMC_INIT) || smc->use_fallback) {
1216 		/* delegate to CLC child sock */
1217 		release_sock(sk);
1218 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
1219 		lock_sock(sk);
1220 		sk->sk_err = smc->clcsock->sk->sk_err;
1221 		if (sk->sk_err) {
1222 			mask |= EPOLLERR;
1223 		} else {
1224 			/* if non-blocking connect finished ... */
1225 			if (sk->sk_state == SMC_INIT &&
1226 			    mask & EPOLLOUT &&
1227 			    smc->clcsock->sk->sk_state != TCP_CLOSE) {
1228 				rc = smc_connect_rdma(smc);
1229 				if (rc < 0)
1230 					mask |= EPOLLERR;
1231 				/* success cases including fallback */
1232 				mask |= EPOLLOUT | EPOLLWRNORM;
1233 			}
1234 		}
1235 	} else {
1236 		if (sk->sk_state != SMC_CLOSED) {
1237 			release_sock(sk);
1238 			sock_poll_wait(file, sk_sleep(sk), wait);
1239 			lock_sock(sk);
1240 		}
1241 		if (sk->sk_err)
1242 			mask |= EPOLLERR;
1243 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1244 		    (sk->sk_state == SMC_CLOSED))
1245 			mask |= EPOLLHUP;
1246 		if (sk->sk_state == SMC_LISTEN) {
1247 			/* woken up by sk_data_ready in smc_listen_work() */
1248 			mask = smc_accept_poll(sk);
1249 		} else {
1250 			if (atomic_read(&smc->conn.sndbuf_space) ||
1251 			    sk->sk_shutdown & SEND_SHUTDOWN) {
1252 				mask |= EPOLLOUT | EPOLLWRNORM;
1253 			} else {
1254 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1255 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1256 			}
1257 			if (atomic_read(&smc->conn.bytes_to_rcv))
1258 				mask |= EPOLLIN | EPOLLRDNORM;
1259 			if (sk->sk_shutdown & RCV_SHUTDOWN)
1260 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
1261 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
1262 				mask |= EPOLLIN;
1263 		}
1264 
1265 	}
1266 	release_sock(sk);
1267 	sock_put(sk);
1268 
1269 	return mask;
1270 }
1271 
1272 static int smc_shutdown(struct socket *sock, int how)
1273 {
1274 	struct sock *sk = sock->sk;
1275 	struct smc_sock *smc;
1276 	int rc = -EINVAL;
1277 	int rc1 = 0;
1278 
1279 	smc = smc_sk(sk);
1280 
1281 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
1282 		return rc;
1283 
1284 	lock_sock(sk);
1285 
1286 	rc = -ENOTCONN;
1287 	if ((sk->sk_state != SMC_LISTEN) &&
1288 	    (sk->sk_state != SMC_ACTIVE) &&
1289 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
1290 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
1291 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1292 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
1293 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
1294 		goto out;
1295 	if (smc->use_fallback) {
1296 		rc = kernel_sock_shutdown(smc->clcsock, how);
1297 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
1298 		if (sk->sk_shutdown == SHUTDOWN_MASK)
1299 			sk->sk_state = SMC_CLOSED;
1300 		goto out;
1301 	}
1302 	switch (how) {
1303 	case SHUT_RDWR:		/* shutdown in both directions */
1304 		rc = smc_close_active(smc);
1305 		break;
1306 	case SHUT_WR:
1307 		rc = smc_close_shutdown_write(smc);
1308 		break;
1309 	case SHUT_RD:
1310 		rc = 0;
1311 		/* nothing more to do because peer is not involved */
1312 		break;
1313 	}
1314 	if (smc->clcsock)
1315 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
1316 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
1317 	sk->sk_shutdown |= how + 1;
1318 
1319 out:
1320 	release_sock(sk);
1321 	return rc ? rc : rc1;
1322 }
1323 
1324 static int smc_setsockopt(struct socket *sock, int level, int optname,
1325 			  char __user *optval, unsigned int optlen)
1326 {
1327 	struct sock *sk = sock->sk;
1328 	struct smc_sock *smc;
1329 	int val, rc;
1330 
1331 	smc = smc_sk(sk);
1332 
1333 	/* generic setsockopts reaching us here always apply to the
1334 	 * CLC socket
1335 	 */
1336 	rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
1337 					   optval, optlen);
1338 	if (smc->clcsock->sk->sk_err) {
1339 		sk->sk_err = smc->clcsock->sk->sk_err;
1340 		sk->sk_error_report(sk);
1341 	}
1342 	if (rc)
1343 		return rc;
1344 
1345 	if (optlen < sizeof(int))
1346 		return rc;
1347 	get_user(val, (int __user *)optval);
1348 
1349 	lock_sock(sk);
1350 	switch (optname) {
1351 	case TCP_ULP:
1352 	case TCP_FASTOPEN:
1353 	case TCP_FASTOPEN_CONNECT:
1354 	case TCP_FASTOPEN_KEY:
1355 	case TCP_FASTOPEN_NO_COOKIE:
1356 		/* option not supported by SMC */
1357 		if (sk->sk_state == SMC_INIT) {
1358 			smc->use_fallback = true;
1359 		} else {
1360 			if (!smc->use_fallback)
1361 				rc = -EINVAL;
1362 		}
1363 		break;
1364 	case TCP_NODELAY:
1365 		if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1366 			if (val && !smc->use_fallback)
1367 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1368 						 0);
1369 		}
1370 		break;
1371 	case TCP_CORK:
1372 		if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1373 			if (!val && !smc->use_fallback)
1374 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1375 						 0);
1376 		}
1377 		break;
1378 	case TCP_DEFER_ACCEPT:
1379 		smc->sockopt_defer_accept = val;
1380 		break;
1381 	default:
1382 		break;
1383 	}
1384 	release_sock(sk);
1385 
1386 	return rc;
1387 }
1388 
1389 static int smc_getsockopt(struct socket *sock, int level, int optname,
1390 			  char __user *optval, int __user *optlen)
1391 {
1392 	struct smc_sock *smc;
1393 
1394 	smc = smc_sk(sock->sk);
1395 	/* socket options apply to the CLC socket */
1396 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
1397 					     optval, optlen);
1398 }
1399 
1400 static int smc_ioctl(struct socket *sock, unsigned int cmd,
1401 		     unsigned long arg)
1402 {
1403 	struct smc_sock *smc;
1404 	int answ;
1405 
1406 	smc = smc_sk(sock->sk);
1407 	if (smc->use_fallback) {
1408 		if (!smc->clcsock)
1409 			return -EBADF;
1410 		return smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
1411 	}
1412 	switch (cmd) {
1413 	case SIOCINQ: /* same as FIONREAD */
1414 		if (smc->sk.sk_state == SMC_LISTEN)
1415 			return -EINVAL;
1416 		answ = atomic_read(&smc->conn.bytes_to_rcv);
1417 		break;
1418 	case SIOCOUTQ:
1419 		/* output queue size (not send + not acked) */
1420 		if (smc->sk.sk_state == SMC_LISTEN)
1421 			return -EINVAL;
1422 		answ = smc->conn.sndbuf_size -
1423 					atomic_read(&smc->conn.sndbuf_space);
1424 		break;
1425 	case SIOCOUTQNSD:
1426 		/* output queue size (not send only) */
1427 		if (smc->sk.sk_state == SMC_LISTEN)
1428 			return -EINVAL;
1429 		answ = smc_tx_prepared_sends(&smc->conn);
1430 		break;
1431 	default:
1432 		return -ENOIOCTLCMD;
1433 	}
1434 
1435 	return put_user(answ, (int __user *)arg);
1436 }
1437 
1438 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
1439 			    int offset, size_t size, int flags)
1440 {
1441 	struct sock *sk = sock->sk;
1442 	struct smc_sock *smc;
1443 	int rc = -EPIPE;
1444 
1445 	smc = smc_sk(sk);
1446 	lock_sock(sk);
1447 	if (sk->sk_state != SMC_ACTIVE) {
1448 		release_sock(sk);
1449 		goto out;
1450 	}
1451 	release_sock(sk);
1452 	if (smc->use_fallback)
1453 		rc = kernel_sendpage(smc->clcsock, page, offset,
1454 				     size, flags);
1455 	else
1456 		rc = sock_no_sendpage(sock, page, offset, size, flags);
1457 
1458 out:
1459 	return rc;
1460 }
1461 
1462 /* Map the affected portions of the rmbe into an spd, note the number of bytes
1463  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
1464  * updates till whenever a respective page has been fully processed.
1465  * Note that subsequent recv() calls have to wait till all splice() processing
1466  * completed.
1467  */
1468 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
1469 			       struct pipe_inode_info *pipe, size_t len,
1470 			       unsigned int flags)
1471 {
1472 	struct sock *sk = sock->sk;
1473 	struct smc_sock *smc;
1474 	int rc = -ENOTCONN;
1475 
1476 	smc = smc_sk(sk);
1477 	lock_sock(sk);
1478 
1479 	if (sk->sk_state == SMC_INIT ||
1480 	    sk->sk_state == SMC_LISTEN ||
1481 	    sk->sk_state == SMC_CLOSED)
1482 		goto out;
1483 
1484 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1485 		rc = 0;
1486 		goto out;
1487 	}
1488 
1489 	if (smc->use_fallback) {
1490 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
1491 						    pipe, len, flags);
1492 	} else {
1493 		if (*ppos) {
1494 			rc = -ESPIPE;
1495 			goto out;
1496 		}
1497 		if (flags & SPLICE_F_NONBLOCK)
1498 			flags = MSG_DONTWAIT;
1499 		else
1500 			flags = 0;
1501 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
1502 	}
1503 out:
1504 	release_sock(sk);
1505 
1506 	return rc;
1507 }
1508 
1509 /* must look like tcp */
1510 static const struct proto_ops smc_sock_ops = {
1511 	.family		= PF_SMC,
1512 	.owner		= THIS_MODULE,
1513 	.release	= smc_release,
1514 	.bind		= smc_bind,
1515 	.connect	= smc_connect,
1516 	.socketpair	= sock_no_socketpair,
1517 	.accept		= smc_accept,
1518 	.getname	= smc_getname,
1519 	.poll		= smc_poll,
1520 	.ioctl		= smc_ioctl,
1521 	.listen		= smc_listen,
1522 	.shutdown	= smc_shutdown,
1523 	.setsockopt	= smc_setsockopt,
1524 	.getsockopt	= smc_getsockopt,
1525 	.sendmsg	= smc_sendmsg,
1526 	.recvmsg	= smc_recvmsg,
1527 	.mmap		= sock_no_mmap,
1528 	.sendpage	= smc_sendpage,
1529 	.splice_read	= smc_splice_read,
1530 };
1531 
1532 static int smc_create(struct net *net, struct socket *sock, int protocol,
1533 		      int kern)
1534 {
1535 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
1536 	struct smc_sock *smc;
1537 	struct sock *sk;
1538 	int rc;
1539 
1540 	rc = -ESOCKTNOSUPPORT;
1541 	if (sock->type != SOCK_STREAM)
1542 		goto out;
1543 
1544 	rc = -EPROTONOSUPPORT;
1545 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
1546 		goto out;
1547 
1548 	rc = -ENOBUFS;
1549 	sock->ops = &smc_sock_ops;
1550 	sk = smc_sock_alloc(net, sock, protocol);
1551 	if (!sk)
1552 		goto out;
1553 
1554 	/* create internal TCP socket for CLC handshake and fallback */
1555 	smc = smc_sk(sk);
1556 	smc->use_fallback = false; /* assume rdma capability first */
1557 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
1558 			      &smc->clcsock);
1559 	if (rc) {
1560 		sk_common_release(sk);
1561 		goto out;
1562 	}
1563 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
1564 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
1565 
1566 out:
1567 	return rc;
1568 }
1569 
1570 static const struct net_proto_family smc_sock_family_ops = {
1571 	.family	= PF_SMC,
1572 	.owner	= THIS_MODULE,
1573 	.create	= smc_create,
1574 };
1575 
1576 static int __init smc_init(void)
1577 {
1578 	int rc;
1579 
1580 	rc = smc_pnet_init();
1581 	if (rc)
1582 		return rc;
1583 
1584 	rc = smc_llc_init();
1585 	if (rc) {
1586 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
1587 		goto out_pnet;
1588 	}
1589 
1590 	rc = smc_cdc_init();
1591 	if (rc) {
1592 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
1593 		goto out_pnet;
1594 	}
1595 
1596 	rc = proto_register(&smc_proto, 1);
1597 	if (rc) {
1598 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
1599 		goto out_pnet;
1600 	}
1601 
1602 	rc = proto_register(&smc_proto6, 1);
1603 	if (rc) {
1604 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
1605 		goto out_proto;
1606 	}
1607 
1608 	rc = sock_register(&smc_sock_family_ops);
1609 	if (rc) {
1610 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
1611 		goto out_proto6;
1612 	}
1613 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
1614 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
1615 
1616 	rc = smc_ib_register_client();
1617 	if (rc) {
1618 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
1619 		goto out_sock;
1620 	}
1621 
1622 	static_branch_enable(&tcp_have_smc);
1623 	return 0;
1624 
1625 out_sock:
1626 	sock_unregister(PF_SMC);
1627 out_proto6:
1628 	proto_unregister(&smc_proto6);
1629 out_proto:
1630 	proto_unregister(&smc_proto);
1631 out_pnet:
1632 	smc_pnet_exit();
1633 	return rc;
1634 }
1635 
1636 static void __exit smc_exit(void)
1637 {
1638 	struct smc_link_group *lgr, *lg;
1639 	LIST_HEAD(lgr_freeing_list);
1640 
1641 	spin_lock_bh(&smc_lgr_list.lock);
1642 	if (!list_empty(&smc_lgr_list.list))
1643 		list_splice_init(&smc_lgr_list.list, &lgr_freeing_list);
1644 	spin_unlock_bh(&smc_lgr_list.lock);
1645 	list_for_each_entry_safe(lgr, lg, &lgr_freeing_list, list) {
1646 		list_del_init(&lgr->list);
1647 		smc_llc_link_inactive(&lgr->lnk[SMC_SINGLE_LINK]);
1648 		cancel_delayed_work_sync(&lgr->free_work);
1649 		smc_lgr_free(lgr); /* free link group */
1650 	}
1651 	static_branch_disable(&tcp_have_smc);
1652 	smc_ib_unregister_client();
1653 	sock_unregister(PF_SMC);
1654 	proto_unregister(&smc_proto6);
1655 	proto_unregister(&smc_proto);
1656 	smc_pnet_exit();
1657 }
1658 
1659 module_init(smc_init);
1660 module_exit(smc_exit);
1661 
1662 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
1663 MODULE_DESCRIPTION("smc socket address family");
1664 MODULE_LICENSE("GPL");
1665 MODULE_ALIAS_NETPROTO(PF_SMC);
1666