xref: /openbmc/linux/net/smc/af_smc.c (revision 8bd1369b)
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  *
12  *  Copyright IBM Corp. 2016, 2018
13  *
14  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
15  *              based on prototype from Frank Blaschka
16  */
17 
18 #define KMSG_COMPONENT "smc"
19 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
20 
21 #include <linux/module.h>
22 #include <linux/socket.h>
23 #include <linux/workqueue.h>
24 #include <linux/in.h>
25 #include <linux/sched/signal.h>
26 
27 #include <net/sock.h>
28 #include <net/tcp.h>
29 #include <net/smc.h>
30 #include <asm/ioctls.h>
31 
32 #include "smc.h"
33 #include "smc_clc.h"
34 #include "smc_llc.h"
35 #include "smc_cdc.h"
36 #include "smc_core.h"
37 #include "smc_ib.h"
38 #include "smc_pnet.h"
39 #include "smc_tx.h"
40 #include "smc_rx.h"
41 #include "smc_close.h"
42 
43 static DEFINE_MUTEX(smc_create_lgr_pending);	/* serialize link group
44 						 * creation
45 						 */
46 
47 static void smc_tcp_listen_work(struct work_struct *);
48 static void smc_connect_work(struct work_struct *);
49 
50 static void smc_set_keepalive(struct sock *sk, int val)
51 {
52 	struct smc_sock *smc = smc_sk(sk);
53 
54 	smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
55 }
56 
57 static struct smc_hashinfo smc_v4_hashinfo = {
58 	.lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
59 };
60 
61 static struct smc_hashinfo smc_v6_hashinfo = {
62 	.lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
63 };
64 
65 int smc_hash_sk(struct sock *sk)
66 {
67 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
68 	struct hlist_head *head;
69 
70 	head = &h->ht;
71 
72 	write_lock_bh(&h->lock);
73 	sk_add_node(sk, head);
74 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
75 	write_unlock_bh(&h->lock);
76 
77 	return 0;
78 }
79 EXPORT_SYMBOL_GPL(smc_hash_sk);
80 
81 void smc_unhash_sk(struct sock *sk)
82 {
83 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
84 
85 	write_lock_bh(&h->lock);
86 	if (sk_del_node_init(sk))
87 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
88 	write_unlock_bh(&h->lock);
89 }
90 EXPORT_SYMBOL_GPL(smc_unhash_sk);
91 
92 struct proto smc_proto = {
93 	.name		= "SMC",
94 	.owner		= THIS_MODULE,
95 	.keepalive	= smc_set_keepalive,
96 	.hash		= smc_hash_sk,
97 	.unhash		= smc_unhash_sk,
98 	.obj_size	= sizeof(struct smc_sock),
99 	.h.smc_hash	= &smc_v4_hashinfo,
100 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
101 };
102 EXPORT_SYMBOL_GPL(smc_proto);
103 
104 struct proto smc_proto6 = {
105 	.name		= "SMC6",
106 	.owner		= THIS_MODULE,
107 	.keepalive	= smc_set_keepalive,
108 	.hash		= smc_hash_sk,
109 	.unhash		= smc_unhash_sk,
110 	.obj_size	= sizeof(struct smc_sock),
111 	.h.smc_hash	= &smc_v6_hashinfo,
112 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
113 };
114 EXPORT_SYMBOL_GPL(smc_proto6);
115 
116 static int smc_release(struct socket *sock)
117 {
118 	struct sock *sk = sock->sk;
119 	struct smc_sock *smc;
120 	int rc = 0;
121 
122 	if (!sk)
123 		goto out;
124 
125 	smc = smc_sk(sk);
126 
127 	/* cleanup for a dangling non-blocking connect */
128 	flush_work(&smc->connect_work);
129 	kfree(smc->connect_info);
130 	smc->connect_info = NULL;
131 
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 		if (sk->sk_state != SMC_LISTEN && sk->sk_state != SMC_INIT)
151 			sock_put(sk); /* passive closing */
152 		sk->sk_state = SMC_CLOSED;
153 		sk->sk_state_change(sk);
154 	}
155 
156 	/* detach socket */
157 	sock_orphan(sk);
158 	sock->sk = NULL;
159 	if (!smc->use_fallback && sk->sk_state == SMC_CLOSED)
160 		smc_conn_free(&smc->conn);
161 	release_sock(sk);
162 
163 	sk->sk_prot->unhash(sk);
164 	sock_put(sk); /* final sock_put */
165 out:
166 	return rc;
167 }
168 
169 static void smc_destruct(struct sock *sk)
170 {
171 	if (sk->sk_state != SMC_CLOSED)
172 		return;
173 	if (!sock_flag(sk, SOCK_DEAD))
174 		return;
175 
176 	sk_refcnt_debug_dec(sk);
177 }
178 
179 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
180 				   int protocol)
181 {
182 	struct smc_sock *smc;
183 	struct proto *prot;
184 	struct sock *sk;
185 
186 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
187 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
188 	if (!sk)
189 		return NULL;
190 
191 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
192 	sk->sk_state = SMC_INIT;
193 	sk->sk_destruct = smc_destruct;
194 	sk->sk_protocol = protocol;
195 	smc = smc_sk(sk);
196 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
197 	INIT_WORK(&smc->connect_work, smc_connect_work);
198 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
199 	INIT_LIST_HEAD(&smc->accept_q);
200 	spin_lock_init(&smc->accept_q_lock);
201 	spin_lock_init(&smc->conn.send_lock);
202 	sk->sk_prot->hash(sk);
203 	sk_refcnt_debug_inc(sk);
204 
205 	return sk;
206 }
207 
208 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
209 		    int addr_len)
210 {
211 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
212 	struct sock *sk = sock->sk;
213 	struct smc_sock *smc;
214 	int rc;
215 
216 	smc = smc_sk(sk);
217 
218 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
219 	rc = -EINVAL;
220 	if (addr_len < sizeof(struct sockaddr_in))
221 		goto out;
222 
223 	rc = -EAFNOSUPPORT;
224 	if (addr->sin_family != AF_INET &&
225 	    addr->sin_family != AF_INET6 &&
226 	    addr->sin_family != AF_UNSPEC)
227 		goto out;
228 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
229 	if (addr->sin_family == AF_UNSPEC &&
230 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
231 		goto out;
232 
233 	lock_sock(sk);
234 
235 	/* Check if socket is already active */
236 	rc = -EINVAL;
237 	if (sk->sk_state != SMC_INIT)
238 		goto out_rel;
239 
240 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
241 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
242 
243 out_rel:
244 	release_sock(sk);
245 out:
246 	return rc;
247 }
248 
249 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
250 				   unsigned long mask)
251 {
252 	/* options we don't get control via setsockopt for */
253 	nsk->sk_type = osk->sk_type;
254 	nsk->sk_sndbuf = osk->sk_sndbuf;
255 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
256 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
257 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
258 	nsk->sk_mark = osk->sk_mark;
259 	nsk->sk_priority = osk->sk_priority;
260 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
261 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
262 	nsk->sk_err = osk->sk_err;
263 
264 	nsk->sk_flags &= ~mask;
265 	nsk->sk_flags |= osk->sk_flags & mask;
266 }
267 
268 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
269 			     (1UL << SOCK_KEEPOPEN) | \
270 			     (1UL << SOCK_LINGER) | \
271 			     (1UL << SOCK_BROADCAST) | \
272 			     (1UL << SOCK_TIMESTAMP) | \
273 			     (1UL << SOCK_DBG) | \
274 			     (1UL << SOCK_RCVTSTAMP) | \
275 			     (1UL << SOCK_RCVTSTAMPNS) | \
276 			     (1UL << SOCK_LOCALROUTE) | \
277 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
278 			     (1UL << SOCK_RXQ_OVFL) | \
279 			     (1UL << SOCK_WIFI_STATUS) | \
280 			     (1UL << SOCK_NOFCS) | \
281 			     (1UL << SOCK_FILTER_LOCKED))
282 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
283  * clc socket (since smc is not called for these options from net/core)
284  */
285 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
286 {
287 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
288 }
289 
290 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
291 			     (1UL << SOCK_KEEPOPEN) | \
292 			     (1UL << SOCK_LINGER) | \
293 			     (1UL << SOCK_DBG))
294 /* copy only settings and flags relevant for smc from clc to smc socket */
295 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
296 {
297 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
298 }
299 
300 /* register a new rmb, optionally send confirm_rkey msg to register with peer */
301 static int smc_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc,
302 		       bool conf_rkey)
303 {
304 	/* register memory region for new rmb */
305 	if (smc_wr_reg_send(link, rmb_desc->mr_rx[SMC_SINGLE_LINK])) {
306 		rmb_desc->regerr = 1;
307 		return -EFAULT;
308 	}
309 	if (!conf_rkey)
310 		return 0;
311 	/* exchange confirm_rkey msg with peer */
312 	if (smc_llc_do_confirm_rkey(link, rmb_desc)) {
313 		rmb_desc->regerr = 1;
314 		return -EFAULT;
315 	}
316 	return 0;
317 }
318 
319 static int smc_clnt_conf_first_link(struct smc_sock *smc)
320 {
321 	struct net *net = sock_net(smc->clcsock->sk);
322 	struct smc_link_group *lgr = smc->conn.lgr;
323 	struct smc_link *link;
324 	int rest;
325 	int rc;
326 
327 	link = &lgr->lnk[SMC_SINGLE_LINK];
328 	/* receive CONFIRM LINK request from server over RoCE fabric */
329 	rest = wait_for_completion_interruptible_timeout(
330 		&link->llc_confirm,
331 		SMC_LLC_WAIT_FIRST_TIME);
332 	if (rest <= 0) {
333 		struct smc_clc_msg_decline dclc;
334 
335 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
336 				      SMC_CLC_DECLINE);
337 		return rc;
338 	}
339 
340 	if (link->llc_confirm_rc)
341 		return SMC_CLC_DECL_RMBE_EC;
342 
343 	rc = smc_ib_modify_qp_rts(link);
344 	if (rc)
345 		return SMC_CLC_DECL_INTERR;
346 
347 	smc_wr_remember_qp_attr(link);
348 
349 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
350 		return SMC_CLC_DECL_INTERR;
351 
352 	/* send CONFIRM LINK response over RoCE fabric */
353 	rc = smc_llc_send_confirm_link(link,
354 				       link->smcibdev->mac[link->ibport - 1],
355 				       &link->smcibdev->gid[link->ibport - 1],
356 				       SMC_LLC_RESP);
357 	if (rc < 0)
358 		return SMC_CLC_DECL_TCL;
359 
360 	/* receive ADD LINK request from server over RoCE fabric */
361 	rest = wait_for_completion_interruptible_timeout(&link->llc_add,
362 							 SMC_LLC_WAIT_TIME);
363 	if (rest <= 0) {
364 		struct smc_clc_msg_decline dclc;
365 
366 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
367 				      SMC_CLC_DECLINE);
368 		return rc;
369 	}
370 
371 	/* send add link reject message, only one link supported for now */
372 	rc = smc_llc_send_add_link(link,
373 				   link->smcibdev->mac[link->ibport - 1],
374 				   &link->smcibdev->gid[link->ibport - 1],
375 				   SMC_LLC_RESP);
376 	if (rc < 0)
377 		return SMC_CLC_DECL_TCL;
378 
379 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
380 
381 	return 0;
382 }
383 
384 static void smc_conn_save_peer_info(struct smc_sock *smc,
385 				    struct smc_clc_msg_accept_confirm *clc)
386 {
387 	int bufsize = smc_uncompress_bufsize(clc->rmbe_size);
388 
389 	smc->conn.peer_rmbe_idx = clc->rmbe_idx;
390 	smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
391 	smc->conn.peer_rmbe_size = bufsize;
392 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
393 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
394 }
395 
396 static void smc_link_save_peer_info(struct smc_link *link,
397 				    struct smc_clc_msg_accept_confirm *clc)
398 {
399 	link->peer_qpn = ntoh24(clc->qpn);
400 	memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
401 	memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
402 	link->peer_psn = ntoh24(clc->psn);
403 	link->peer_mtu = clc->qp_mtu;
404 }
405 
406 /* fall back during connect */
407 static int smc_connect_fallback(struct smc_sock *smc)
408 {
409 	smc->use_fallback = true;
410 	smc_copy_sock_settings_to_clc(smc);
411 	if (smc->sk.sk_state == SMC_INIT)
412 		smc->sk.sk_state = SMC_ACTIVE;
413 	return 0;
414 }
415 
416 /* decline and fall back during connect */
417 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code)
418 {
419 	int rc;
420 
421 	if (reason_code < 0) { /* error, fallback is not possible */
422 		if (smc->sk.sk_state == SMC_INIT)
423 			sock_put(&smc->sk); /* passive closing */
424 		return reason_code;
425 	}
426 	if (reason_code != SMC_CLC_DECL_REPLY) {
427 		rc = smc_clc_send_decline(smc, reason_code);
428 		if (rc < 0) {
429 			if (smc->sk.sk_state == SMC_INIT)
430 				sock_put(&smc->sk); /* passive closing */
431 			return rc;
432 		}
433 	}
434 	return smc_connect_fallback(smc);
435 }
436 
437 /* abort connecting */
438 static int smc_connect_abort(struct smc_sock *smc, int reason_code,
439 			     int local_contact)
440 {
441 	if (local_contact == SMC_FIRST_CONTACT)
442 		smc_lgr_forget(smc->conn.lgr);
443 	mutex_unlock(&smc_create_lgr_pending);
444 	smc_conn_free(&smc->conn);
445 	return reason_code;
446 }
447 
448 /* check if there is a rdma device available for this connection. */
449 /* called for connect and listen */
450 static int smc_check_rdma(struct smc_sock *smc, struct smc_ib_device **ibdev,
451 			  u8 *ibport)
452 {
453 	int reason_code = 0;
454 
455 	/* PNET table look up: search active ib_device and port
456 	 * within same PNETID that also contains the ethernet device
457 	 * used for the internal TCP socket
458 	 */
459 	smc_pnet_find_roce_resource(smc->clcsock->sk, ibdev, ibport);
460 	if (!(*ibdev))
461 		reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
462 
463 	return reason_code;
464 }
465 
466 /* CLC handshake during connect */
467 static int smc_connect_clc(struct smc_sock *smc,
468 			   struct smc_clc_msg_accept_confirm *aclc,
469 			   struct smc_ib_device *ibdev, u8 ibport)
470 {
471 	int rc = 0;
472 
473 	/* do inband token exchange */
474 	rc = smc_clc_send_proposal(smc, ibdev, ibport);
475 	if (rc)
476 		return rc;
477 	/* receive SMC Accept CLC message */
478 	return smc_clc_wait_msg(smc, aclc, sizeof(*aclc), SMC_CLC_ACCEPT);
479 }
480 
481 /* setup for RDMA connection of client */
482 static int smc_connect_rdma(struct smc_sock *smc,
483 			    struct smc_clc_msg_accept_confirm *aclc,
484 			    struct smc_ib_device *ibdev, u8 ibport)
485 {
486 	int local_contact = SMC_FIRST_CONTACT;
487 	struct smc_link *link;
488 	int reason_code = 0;
489 
490 	mutex_lock(&smc_create_lgr_pending);
491 	local_contact = smc_conn_create(smc, ibdev, ibport, &aclc->lcl,
492 					aclc->hdr.flag);
493 	if (local_contact < 0) {
494 		if (local_contact == -ENOMEM)
495 			reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
496 		else if (local_contact == -ENOLINK)
497 			reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
498 		else
499 			reason_code = SMC_CLC_DECL_INTERR; /* other error */
500 		return smc_connect_abort(smc, reason_code, 0);
501 	}
502 	link = &smc->conn.lgr->lnk[SMC_SINGLE_LINK];
503 
504 	smc_conn_save_peer_info(smc, aclc);
505 
506 	/* create send buffer and rmb */
507 	if (smc_buf_create(smc))
508 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM, local_contact);
509 
510 	if (local_contact == SMC_FIRST_CONTACT)
511 		smc_link_save_peer_info(link, aclc);
512 
513 	if (smc_rmb_rtoken_handling(&smc->conn, aclc))
514 		return smc_connect_abort(smc, SMC_CLC_DECL_INTERR,
515 					 local_contact);
516 
517 	smc_close_init(smc);
518 	smc_rx_init(smc);
519 
520 	if (local_contact == SMC_FIRST_CONTACT) {
521 		if (smc_ib_ready_link(link))
522 			return smc_connect_abort(smc, SMC_CLC_DECL_INTERR,
523 						 local_contact);
524 	} else {
525 		if (!smc->conn.rmb_desc->reused &&
526 		    smc_reg_rmb(link, smc->conn.rmb_desc, true))
527 			return smc_connect_abort(smc, SMC_CLC_DECL_INTERR,
528 						 local_contact);
529 	}
530 	smc_rmb_sync_sg_for_device(&smc->conn);
531 
532 	reason_code = smc_clc_send_confirm(smc);
533 	if (reason_code)
534 		return smc_connect_abort(smc, reason_code, local_contact);
535 
536 	smc_tx_init(smc);
537 
538 	if (local_contact == SMC_FIRST_CONTACT) {
539 		/* QP confirmation over RoCE fabric */
540 		reason_code = smc_clnt_conf_first_link(smc);
541 		if (reason_code)
542 			return smc_connect_abort(smc, reason_code,
543 						 local_contact);
544 	}
545 	mutex_unlock(&smc_create_lgr_pending);
546 
547 	smc_copy_sock_settings_to_clc(smc);
548 	if (smc->sk.sk_state == SMC_INIT)
549 		smc->sk.sk_state = SMC_ACTIVE;
550 
551 	return 0;
552 }
553 
554 /* perform steps before actually connecting */
555 static int __smc_connect(struct smc_sock *smc)
556 {
557 	struct smc_clc_msg_accept_confirm aclc;
558 	struct smc_ib_device *ibdev;
559 	int rc = 0;
560 	u8 ibport;
561 
562 	sock_hold(&smc->sk); /* sock put in passive closing */
563 
564 	if (smc->use_fallback)
565 		return smc_connect_fallback(smc);
566 
567 	/* if peer has not signalled SMC-capability, fall back */
568 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
569 		return smc_connect_fallback(smc);
570 
571 	/* IPSec connections opt out of SMC-R optimizations */
572 	if (using_ipsec(smc))
573 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC);
574 
575 	/* check if a RDMA device is available; if not, fall back */
576 	if (smc_check_rdma(smc, &ibdev, &ibport))
577 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_CNFERR);
578 
579 	/* perform CLC handshake */
580 	rc = smc_connect_clc(smc, &aclc, ibdev, ibport);
581 	if (rc)
582 		return smc_connect_decline_fallback(smc, rc);
583 
584 	/* connect using rdma */
585 	rc = smc_connect_rdma(smc, &aclc, ibdev, ibport);
586 	if (rc)
587 		return smc_connect_decline_fallback(smc, rc);
588 
589 	return 0;
590 }
591 
592 static void smc_connect_work(struct work_struct *work)
593 {
594 	struct smc_sock *smc = container_of(work, struct smc_sock,
595 					    connect_work);
596 	int rc;
597 
598 	lock_sock(&smc->sk);
599 	rc = kernel_connect(smc->clcsock, &smc->connect_info->addr,
600 			    smc->connect_info->alen, smc->connect_info->flags);
601 	if (smc->clcsock->sk->sk_err) {
602 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
603 		goto out;
604 	}
605 	if (rc < 0) {
606 		smc->sk.sk_err = -rc;
607 		goto out;
608 	}
609 
610 	rc = __smc_connect(smc);
611 	if (rc < 0)
612 		smc->sk.sk_err = -rc;
613 
614 out:
615 	smc->sk.sk_state_change(&smc->sk);
616 	kfree(smc->connect_info);
617 	smc->connect_info = NULL;
618 	release_sock(&smc->sk);
619 }
620 
621 static int smc_connect(struct socket *sock, struct sockaddr *addr,
622 		       int alen, int flags)
623 {
624 	struct sock *sk = sock->sk;
625 	struct smc_sock *smc;
626 	int rc = -EINVAL;
627 
628 	smc = smc_sk(sk);
629 
630 	/* separate smc parameter checking to be safe */
631 	if (alen < sizeof(addr->sa_family))
632 		goto out_err;
633 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
634 		goto out_err;
635 
636 	lock_sock(sk);
637 	switch (sk->sk_state) {
638 	default:
639 		goto out;
640 	case SMC_ACTIVE:
641 		rc = -EISCONN;
642 		goto out;
643 	case SMC_INIT:
644 		rc = 0;
645 		break;
646 	}
647 
648 	smc_copy_sock_settings_to_clc(smc);
649 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
650 	if (flags & O_NONBLOCK) {
651 		if (smc->connect_info) {
652 			rc = -EALREADY;
653 			goto out;
654 		}
655 		smc->connect_info = kzalloc(alen + 2 * sizeof(int), GFP_KERNEL);
656 		if (!smc->connect_info) {
657 			rc = -ENOMEM;
658 			goto out;
659 		}
660 		smc->connect_info->alen = alen;
661 		smc->connect_info->flags = flags ^ O_NONBLOCK;
662 		memcpy(&smc->connect_info->addr, addr, alen);
663 		schedule_work(&smc->connect_work);
664 		rc = -EINPROGRESS;
665 	} else {
666 		rc = kernel_connect(smc->clcsock, addr, alen, flags);
667 		if (rc)
668 			goto out;
669 
670 		rc = __smc_connect(smc);
671 		if (rc < 0)
672 			goto out;
673 		else
674 			rc = 0; /* success cases including fallback */
675 	}
676 
677 out:
678 	release_sock(sk);
679 out_err:
680 	return rc;
681 }
682 
683 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
684 {
685 	struct socket *new_clcsock = NULL;
686 	struct sock *lsk = &lsmc->sk;
687 	struct sock *new_sk;
688 	int rc;
689 
690 	release_sock(lsk);
691 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
692 	if (!new_sk) {
693 		rc = -ENOMEM;
694 		lsk->sk_err = ENOMEM;
695 		*new_smc = NULL;
696 		lock_sock(lsk);
697 		goto out;
698 	}
699 	*new_smc = smc_sk(new_sk);
700 
701 	rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
702 	lock_sock(lsk);
703 	if  (rc < 0)
704 		lsk->sk_err = -rc;
705 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
706 		if (new_clcsock)
707 			sock_release(new_clcsock);
708 		new_sk->sk_state = SMC_CLOSED;
709 		sock_set_flag(new_sk, SOCK_DEAD);
710 		new_sk->sk_prot->unhash(new_sk);
711 		sock_put(new_sk); /* final */
712 		*new_smc = NULL;
713 		goto out;
714 	}
715 
716 	(*new_smc)->clcsock = new_clcsock;
717 out:
718 	return rc;
719 }
720 
721 /* add a just created sock to the accept queue of the listen sock as
722  * candidate for a following socket accept call from user space
723  */
724 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
725 {
726 	struct smc_sock *par = smc_sk(parent);
727 
728 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
729 	spin_lock(&par->accept_q_lock);
730 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
731 	spin_unlock(&par->accept_q_lock);
732 	sk_acceptq_added(parent);
733 }
734 
735 /* remove a socket from the accept queue of its parental listening socket */
736 static void smc_accept_unlink(struct sock *sk)
737 {
738 	struct smc_sock *par = smc_sk(sk)->listen_smc;
739 
740 	spin_lock(&par->accept_q_lock);
741 	list_del_init(&smc_sk(sk)->accept_q);
742 	spin_unlock(&par->accept_q_lock);
743 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
744 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
745 }
746 
747 /* remove a sock from the accept queue to bind it to a new socket created
748  * for a socket accept call from user space
749  */
750 struct sock *smc_accept_dequeue(struct sock *parent,
751 				struct socket *new_sock)
752 {
753 	struct smc_sock *isk, *n;
754 	struct sock *new_sk;
755 
756 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
757 		new_sk = (struct sock *)isk;
758 
759 		smc_accept_unlink(new_sk);
760 		if (new_sk->sk_state == SMC_CLOSED) {
761 			if (isk->clcsock) {
762 				sock_release(isk->clcsock);
763 				isk->clcsock = NULL;
764 			}
765 			new_sk->sk_prot->unhash(new_sk);
766 			sock_put(new_sk); /* final */
767 			continue;
768 		}
769 		if (new_sock)
770 			sock_graft(new_sk, new_sock);
771 		return new_sk;
772 	}
773 	return NULL;
774 }
775 
776 /* clean up for a created but never accepted sock */
777 void smc_close_non_accepted(struct sock *sk)
778 {
779 	struct smc_sock *smc = smc_sk(sk);
780 
781 	lock_sock(sk);
782 	if (!sk->sk_lingertime)
783 		/* wait for peer closing */
784 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
785 	if (!smc->use_fallback) {
786 		smc_close_active(smc);
787 		sock_set_flag(sk, SOCK_DEAD);
788 		sk->sk_shutdown |= SHUTDOWN_MASK;
789 	}
790 	if (smc->clcsock) {
791 		struct socket *tcp;
792 
793 		tcp = smc->clcsock;
794 		smc->clcsock = NULL;
795 		sock_release(tcp);
796 	}
797 	if (smc->use_fallback) {
798 		sock_put(sk); /* passive closing */
799 		sk->sk_state = SMC_CLOSED;
800 	} else {
801 		if (sk->sk_state == SMC_CLOSED)
802 			smc_conn_free(&smc->conn);
803 	}
804 	release_sock(sk);
805 	sk->sk_prot->unhash(sk);
806 	sock_put(sk); /* final sock_put */
807 }
808 
809 static int smc_serv_conf_first_link(struct smc_sock *smc)
810 {
811 	struct net *net = sock_net(smc->clcsock->sk);
812 	struct smc_link_group *lgr = smc->conn.lgr;
813 	struct smc_link *link;
814 	int rest;
815 	int rc;
816 
817 	link = &lgr->lnk[SMC_SINGLE_LINK];
818 
819 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
820 		return SMC_CLC_DECL_INTERR;
821 
822 	/* send CONFIRM LINK request to client over the RoCE fabric */
823 	rc = smc_llc_send_confirm_link(link,
824 				       link->smcibdev->mac[link->ibport - 1],
825 				       &link->smcibdev->gid[link->ibport - 1],
826 				       SMC_LLC_REQ);
827 	if (rc < 0)
828 		return SMC_CLC_DECL_TCL;
829 
830 	/* receive CONFIRM LINK response from client over the RoCE fabric */
831 	rest = wait_for_completion_interruptible_timeout(
832 		&link->llc_confirm_resp,
833 		SMC_LLC_WAIT_FIRST_TIME);
834 	if (rest <= 0) {
835 		struct smc_clc_msg_decline dclc;
836 
837 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
838 				      SMC_CLC_DECLINE);
839 		return rc;
840 	}
841 
842 	if (link->llc_confirm_resp_rc)
843 		return SMC_CLC_DECL_RMBE_EC;
844 
845 	/* send ADD LINK request to client over the RoCE fabric */
846 	rc = smc_llc_send_add_link(link,
847 				   link->smcibdev->mac[link->ibport - 1],
848 				   &link->smcibdev->gid[link->ibport - 1],
849 				   SMC_LLC_REQ);
850 	if (rc < 0)
851 		return SMC_CLC_DECL_TCL;
852 
853 	/* receive ADD LINK response from client over the RoCE fabric */
854 	rest = wait_for_completion_interruptible_timeout(&link->llc_add_resp,
855 							 SMC_LLC_WAIT_TIME);
856 	if (rest <= 0) {
857 		struct smc_clc_msg_decline dclc;
858 
859 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
860 				      SMC_CLC_DECLINE);
861 		return rc;
862 	}
863 
864 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
865 
866 	return 0;
867 }
868 
869 /* listen worker: finish */
870 static void smc_listen_out(struct smc_sock *new_smc)
871 {
872 	struct smc_sock *lsmc = new_smc->listen_smc;
873 	struct sock *newsmcsk = &new_smc->sk;
874 
875 	lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
876 	if (lsmc->sk.sk_state == SMC_LISTEN) {
877 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
878 	} else { /* no longer listening */
879 		smc_close_non_accepted(newsmcsk);
880 	}
881 	release_sock(&lsmc->sk);
882 
883 	/* Wake up accept */
884 	lsmc->sk.sk_data_ready(&lsmc->sk);
885 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
886 }
887 
888 /* listen worker: finish in state connected */
889 static void smc_listen_out_connected(struct smc_sock *new_smc)
890 {
891 	struct sock *newsmcsk = &new_smc->sk;
892 
893 	sk_refcnt_debug_inc(newsmcsk);
894 	if (newsmcsk->sk_state == SMC_INIT)
895 		newsmcsk->sk_state = SMC_ACTIVE;
896 
897 	smc_listen_out(new_smc);
898 }
899 
900 /* listen worker: finish in error state */
901 static void smc_listen_out_err(struct smc_sock *new_smc)
902 {
903 	struct sock *newsmcsk = &new_smc->sk;
904 
905 	if (newsmcsk->sk_state == SMC_INIT)
906 		sock_put(&new_smc->sk); /* passive closing */
907 	newsmcsk->sk_state = SMC_CLOSED;
908 	smc_conn_free(&new_smc->conn);
909 
910 	smc_listen_out(new_smc);
911 }
912 
913 /* listen worker: decline and fall back if possible */
914 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
915 			       int local_contact)
916 {
917 	/* RDMA setup failed, switch back to TCP */
918 	if (local_contact == SMC_FIRST_CONTACT)
919 		smc_lgr_forget(new_smc->conn.lgr);
920 	if (reason_code < 0) { /* error, no fallback possible */
921 		smc_listen_out_err(new_smc);
922 		return;
923 	}
924 	smc_conn_free(&new_smc->conn);
925 	new_smc->use_fallback = true;
926 	if (reason_code && reason_code != SMC_CLC_DECL_REPLY) {
927 		if (smc_clc_send_decline(new_smc, reason_code) < 0) {
928 			smc_listen_out_err(new_smc);
929 			return;
930 		}
931 	}
932 	smc_listen_out_connected(new_smc);
933 }
934 
935 /* listen worker: check prefixes */
936 static int smc_listen_rdma_check(struct smc_sock *new_smc,
937 				 struct smc_clc_msg_proposal *pclc)
938 {
939 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
940 	struct socket *newclcsock = new_smc->clcsock;
941 
942 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
943 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
944 		return SMC_CLC_DECL_CNFERR;
945 
946 	return 0;
947 }
948 
949 /* listen worker: initialize connection and buffers */
950 static int smc_listen_rdma_init(struct smc_sock *new_smc,
951 				struct smc_clc_msg_proposal *pclc,
952 				struct smc_ib_device *ibdev, u8 ibport,
953 				int *local_contact)
954 {
955 	/* allocate connection / link group */
956 	*local_contact = smc_conn_create(new_smc, ibdev, ibport, &pclc->lcl, 0);
957 	if (*local_contact < 0) {
958 		if (*local_contact == -ENOMEM)
959 			return SMC_CLC_DECL_MEM;/* insufficient memory*/
960 		return SMC_CLC_DECL_INTERR; /* other error */
961 	}
962 
963 	/* create send buffer and rmb */
964 	if (smc_buf_create(new_smc))
965 		return SMC_CLC_DECL_MEM;
966 
967 	return 0;
968 }
969 
970 /* listen worker: register buffers */
971 static int smc_listen_rdma_reg(struct smc_sock *new_smc, int local_contact)
972 {
973 	struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
974 
975 	if (local_contact != SMC_FIRST_CONTACT) {
976 		if (!new_smc->conn.rmb_desc->reused) {
977 			if (smc_reg_rmb(link, new_smc->conn.rmb_desc, true))
978 				return SMC_CLC_DECL_INTERR;
979 		}
980 	}
981 	smc_rmb_sync_sg_for_device(&new_smc->conn);
982 
983 	return 0;
984 }
985 
986 /* listen worker: finish RDMA setup */
987 static void smc_listen_rdma_finish(struct smc_sock *new_smc,
988 				   struct smc_clc_msg_accept_confirm *cclc,
989 				   int local_contact)
990 {
991 	struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
992 	int reason_code = 0;
993 
994 	if (local_contact == SMC_FIRST_CONTACT)
995 		smc_link_save_peer_info(link, cclc);
996 
997 	if (smc_rmb_rtoken_handling(&new_smc->conn, cclc)) {
998 		reason_code = SMC_CLC_DECL_INTERR;
999 		goto decline;
1000 	}
1001 
1002 	if (local_contact == SMC_FIRST_CONTACT) {
1003 		if (smc_ib_ready_link(link)) {
1004 			reason_code = SMC_CLC_DECL_INTERR;
1005 			goto decline;
1006 		}
1007 		/* QP confirmation over RoCE fabric */
1008 		reason_code = smc_serv_conf_first_link(new_smc);
1009 		if (reason_code)
1010 			goto decline;
1011 	}
1012 	return;
1013 
1014 decline:
1015 	mutex_unlock(&smc_create_lgr_pending);
1016 	smc_listen_decline(new_smc, reason_code, local_contact);
1017 }
1018 
1019 /* setup for RDMA connection of server */
1020 static void smc_listen_work(struct work_struct *work)
1021 {
1022 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
1023 						smc_listen_work);
1024 	struct socket *newclcsock = new_smc->clcsock;
1025 	struct smc_clc_msg_accept_confirm cclc;
1026 	struct smc_clc_msg_proposal *pclc;
1027 	struct smc_ib_device *ibdev;
1028 	u8 buf[SMC_CLC_MAX_LEN];
1029 	int local_contact = 0;
1030 	int reason_code = 0;
1031 	int rc = 0;
1032 	u8 ibport;
1033 
1034 	if (new_smc->use_fallback) {
1035 		smc_listen_out_connected(new_smc);
1036 		return;
1037 	}
1038 
1039 	/* check if peer is smc capable */
1040 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
1041 		new_smc->use_fallback = true;
1042 		smc_listen_out_connected(new_smc);
1043 		return;
1044 	}
1045 
1046 	/* do inband token exchange -
1047 	 * wait for and receive SMC Proposal CLC message
1048 	 */
1049 	pclc = (struct smc_clc_msg_proposal *)&buf;
1050 	reason_code = smc_clc_wait_msg(new_smc, pclc, SMC_CLC_MAX_LEN,
1051 				       SMC_CLC_PROPOSAL);
1052 	if (reason_code) {
1053 		smc_listen_decline(new_smc, reason_code, 0);
1054 		return;
1055 	}
1056 
1057 	/* IPSec connections opt out of SMC-R optimizations */
1058 	if (using_ipsec(new_smc)) {
1059 		smc_listen_decline(new_smc, SMC_CLC_DECL_IPSEC, 0);
1060 		return;
1061 	}
1062 
1063 	mutex_lock(&smc_create_lgr_pending);
1064 	smc_close_init(new_smc);
1065 	smc_rx_init(new_smc);
1066 	smc_tx_init(new_smc);
1067 
1068 	/* check if RDMA is available */
1069 	if (smc_check_rdma(new_smc, &ibdev, &ibport) ||
1070 	    smc_listen_rdma_check(new_smc, pclc) ||
1071 	    smc_listen_rdma_init(new_smc, pclc, ibdev, ibport,
1072 				 &local_contact) ||
1073 	    smc_listen_rdma_reg(new_smc, local_contact)) {
1074 		/* SMC not supported, decline */
1075 		mutex_unlock(&smc_create_lgr_pending);
1076 		smc_listen_decline(new_smc, SMC_CLC_DECL_CNFERR, local_contact);
1077 		return;
1078 	}
1079 
1080 	/* send SMC Accept CLC message */
1081 	rc = smc_clc_send_accept(new_smc, local_contact);
1082 	if (rc) {
1083 		mutex_unlock(&smc_create_lgr_pending);
1084 		smc_listen_decline(new_smc, rc, local_contact);
1085 		return;
1086 	}
1087 
1088 	/* receive SMC Confirm CLC message */
1089 	reason_code = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
1090 				       SMC_CLC_CONFIRM);
1091 	if (reason_code) {
1092 		mutex_unlock(&smc_create_lgr_pending);
1093 		smc_listen_decline(new_smc, reason_code, local_contact);
1094 		return;
1095 	}
1096 
1097 	/* finish worker */
1098 	smc_listen_rdma_finish(new_smc, &cclc, local_contact);
1099 	smc_conn_save_peer_info(new_smc, &cclc);
1100 	mutex_unlock(&smc_create_lgr_pending);
1101 	smc_listen_out_connected(new_smc);
1102 }
1103 
1104 static void smc_tcp_listen_work(struct work_struct *work)
1105 {
1106 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
1107 					     tcp_listen_work);
1108 	struct sock *lsk = &lsmc->sk;
1109 	struct smc_sock *new_smc;
1110 	int rc = 0;
1111 
1112 	lock_sock(lsk);
1113 	while (lsk->sk_state == SMC_LISTEN) {
1114 		rc = smc_clcsock_accept(lsmc, &new_smc);
1115 		if (rc)
1116 			goto out;
1117 		if (!new_smc)
1118 			continue;
1119 
1120 		new_smc->listen_smc = lsmc;
1121 		new_smc->use_fallback = lsmc->use_fallback;
1122 		sock_hold(lsk); /* sock_put in smc_listen_work */
1123 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
1124 		smc_copy_sock_settings_to_smc(new_smc);
1125 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
1126 		if (!schedule_work(&new_smc->smc_listen_work))
1127 			sock_put(&new_smc->sk);
1128 	}
1129 
1130 out:
1131 	release_sock(lsk);
1132 	sock_put(&lsmc->sk); /* sock_hold in smc_listen */
1133 }
1134 
1135 static int smc_listen(struct socket *sock, int backlog)
1136 {
1137 	struct sock *sk = sock->sk;
1138 	struct smc_sock *smc;
1139 	int rc;
1140 
1141 	smc = smc_sk(sk);
1142 	lock_sock(sk);
1143 
1144 	rc = -EINVAL;
1145 	if ((sk->sk_state != SMC_INIT) && (sk->sk_state != SMC_LISTEN))
1146 		goto out;
1147 
1148 	rc = 0;
1149 	if (sk->sk_state == SMC_LISTEN) {
1150 		sk->sk_max_ack_backlog = backlog;
1151 		goto out;
1152 	}
1153 	/* some socket options are handled in core, so we could not apply
1154 	 * them to the clc socket -- copy smc socket options to clc socket
1155 	 */
1156 	smc_copy_sock_settings_to_clc(smc);
1157 	if (!smc->use_fallback)
1158 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1159 
1160 	rc = kernel_listen(smc->clcsock, backlog);
1161 	if (rc)
1162 		goto out;
1163 	sk->sk_max_ack_backlog = backlog;
1164 	sk->sk_ack_backlog = 0;
1165 	sk->sk_state = SMC_LISTEN;
1166 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
1167 	sock_hold(sk); /* sock_hold in tcp_listen_worker */
1168 	if (!schedule_work(&smc->tcp_listen_work))
1169 		sock_put(sk);
1170 
1171 out:
1172 	release_sock(sk);
1173 	return rc;
1174 }
1175 
1176 static int smc_accept(struct socket *sock, struct socket *new_sock,
1177 		      int flags, bool kern)
1178 {
1179 	struct sock *sk = sock->sk, *nsk;
1180 	DECLARE_WAITQUEUE(wait, current);
1181 	struct smc_sock *lsmc;
1182 	long timeo;
1183 	int rc = 0;
1184 
1185 	lsmc = smc_sk(sk);
1186 	sock_hold(sk); /* sock_put below */
1187 	lock_sock(sk);
1188 
1189 	if (lsmc->sk.sk_state != SMC_LISTEN) {
1190 		rc = -EINVAL;
1191 		release_sock(sk);
1192 		goto out;
1193 	}
1194 
1195 	/* Wait for an incoming connection */
1196 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1197 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
1198 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1199 		set_current_state(TASK_INTERRUPTIBLE);
1200 		if (!timeo) {
1201 			rc = -EAGAIN;
1202 			break;
1203 		}
1204 		release_sock(sk);
1205 		timeo = schedule_timeout(timeo);
1206 		/* wakeup by sk_data_ready in smc_listen_work() */
1207 		sched_annotate_sleep();
1208 		lock_sock(sk);
1209 		if (signal_pending(current)) {
1210 			rc = sock_intr_errno(timeo);
1211 			break;
1212 		}
1213 	}
1214 	set_current_state(TASK_RUNNING);
1215 	remove_wait_queue(sk_sleep(sk), &wait);
1216 
1217 	if (!rc)
1218 		rc = sock_error(nsk);
1219 	release_sock(sk);
1220 	if (rc)
1221 		goto out;
1222 
1223 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
1224 		/* wait till data arrives on the socket */
1225 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
1226 								MSEC_PER_SEC);
1227 		if (smc_sk(nsk)->use_fallback) {
1228 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
1229 
1230 			lock_sock(clcsk);
1231 			if (skb_queue_empty(&clcsk->sk_receive_queue))
1232 				sk_wait_data(clcsk, &timeo, NULL);
1233 			release_sock(clcsk);
1234 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
1235 			lock_sock(nsk);
1236 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
1237 			release_sock(nsk);
1238 		}
1239 	}
1240 
1241 out:
1242 	sock_put(sk); /* sock_hold above */
1243 	return rc;
1244 }
1245 
1246 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1247 		       int peer)
1248 {
1249 	struct smc_sock *smc;
1250 
1251 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
1252 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
1253 		return -ENOTCONN;
1254 
1255 	smc = smc_sk(sock->sk);
1256 
1257 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
1258 }
1259 
1260 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1261 {
1262 	struct sock *sk = sock->sk;
1263 	struct smc_sock *smc;
1264 	int rc = -EPIPE;
1265 
1266 	smc = smc_sk(sk);
1267 	lock_sock(sk);
1268 	if ((sk->sk_state != SMC_ACTIVE) &&
1269 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1270 	    (sk->sk_state != SMC_INIT))
1271 		goto out;
1272 
1273 	if (msg->msg_flags & MSG_FASTOPEN) {
1274 		if (sk->sk_state == SMC_INIT) {
1275 			smc->use_fallback = true;
1276 		} else {
1277 			rc = -EINVAL;
1278 			goto out;
1279 		}
1280 	}
1281 
1282 	if (smc->use_fallback)
1283 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
1284 	else
1285 		rc = smc_tx_sendmsg(smc, msg, len);
1286 out:
1287 	release_sock(sk);
1288 	return rc;
1289 }
1290 
1291 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1292 		       int flags)
1293 {
1294 	struct sock *sk = sock->sk;
1295 	struct smc_sock *smc;
1296 	int rc = -ENOTCONN;
1297 
1298 	smc = smc_sk(sk);
1299 	lock_sock(sk);
1300 	if ((sk->sk_state == SMC_INIT) ||
1301 	    (sk->sk_state == SMC_LISTEN) ||
1302 	    (sk->sk_state == SMC_CLOSED))
1303 		goto out;
1304 
1305 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1306 		rc = 0;
1307 		goto out;
1308 	}
1309 
1310 	if (smc->use_fallback) {
1311 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
1312 	} else {
1313 		msg->msg_namelen = 0;
1314 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
1315 	}
1316 
1317 out:
1318 	release_sock(sk);
1319 	return rc;
1320 }
1321 
1322 static __poll_t smc_accept_poll(struct sock *parent)
1323 {
1324 	struct smc_sock *isk = smc_sk(parent);
1325 	__poll_t mask = 0;
1326 
1327 	spin_lock(&isk->accept_q_lock);
1328 	if (!list_empty(&isk->accept_q))
1329 		mask = EPOLLIN | EPOLLRDNORM;
1330 	spin_unlock(&isk->accept_q_lock);
1331 
1332 	return mask;
1333 }
1334 
1335 static __poll_t smc_poll(struct file *file, struct socket *sock,
1336 			     poll_table *wait)
1337 {
1338 	struct sock *sk = sock->sk;
1339 	__poll_t mask = 0;
1340 	struct smc_sock *smc;
1341 
1342 	if (!sk)
1343 		return EPOLLNVAL;
1344 
1345 	smc = smc_sk(sock->sk);
1346 	if ((sk->sk_state == SMC_INIT) || smc->use_fallback) {
1347 		/* delegate to CLC child sock */
1348 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
1349 		sk->sk_err = smc->clcsock->sk->sk_err;
1350 		if (sk->sk_err)
1351 			mask |= EPOLLERR;
1352 	} else {
1353 		if (sk->sk_state != SMC_CLOSED)
1354 			sock_poll_wait(file, sk_sleep(sk), wait);
1355 		if (sk->sk_err)
1356 			mask |= EPOLLERR;
1357 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1358 		    (sk->sk_state == SMC_CLOSED))
1359 			mask |= EPOLLHUP;
1360 		if (sk->sk_state == SMC_LISTEN) {
1361 			/* woken up by sk_data_ready in smc_listen_work() */
1362 			mask = smc_accept_poll(sk);
1363 		} else {
1364 			if (atomic_read(&smc->conn.sndbuf_space) ||
1365 			    sk->sk_shutdown & SEND_SHUTDOWN) {
1366 				mask |= EPOLLOUT | EPOLLWRNORM;
1367 			} else {
1368 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1369 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1370 			}
1371 			if (atomic_read(&smc->conn.bytes_to_rcv))
1372 				mask |= EPOLLIN | EPOLLRDNORM;
1373 			if (sk->sk_shutdown & RCV_SHUTDOWN)
1374 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
1375 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
1376 				mask |= EPOLLIN;
1377 		}
1378 		if (smc->conn.urg_state == SMC_URG_VALID)
1379 			mask |= EPOLLPRI;
1380 	}
1381 
1382 	return mask;
1383 }
1384 
1385 static int smc_shutdown(struct socket *sock, int how)
1386 {
1387 	struct sock *sk = sock->sk;
1388 	struct smc_sock *smc;
1389 	int rc = -EINVAL;
1390 	int rc1 = 0;
1391 
1392 	smc = smc_sk(sk);
1393 
1394 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
1395 		return rc;
1396 
1397 	lock_sock(sk);
1398 
1399 	rc = -ENOTCONN;
1400 	if ((sk->sk_state != SMC_LISTEN) &&
1401 	    (sk->sk_state != SMC_ACTIVE) &&
1402 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
1403 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
1404 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1405 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
1406 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
1407 		goto out;
1408 	if (smc->use_fallback) {
1409 		rc = kernel_sock_shutdown(smc->clcsock, how);
1410 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
1411 		if (sk->sk_shutdown == SHUTDOWN_MASK)
1412 			sk->sk_state = SMC_CLOSED;
1413 		goto out;
1414 	}
1415 	switch (how) {
1416 	case SHUT_RDWR:		/* shutdown in both directions */
1417 		rc = smc_close_active(smc);
1418 		break;
1419 	case SHUT_WR:
1420 		rc = smc_close_shutdown_write(smc);
1421 		break;
1422 	case SHUT_RD:
1423 		rc = 0;
1424 		/* nothing more to do because peer is not involved */
1425 		break;
1426 	}
1427 	if (smc->clcsock)
1428 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
1429 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
1430 	sk->sk_shutdown |= how + 1;
1431 
1432 out:
1433 	release_sock(sk);
1434 	return rc ? rc : rc1;
1435 }
1436 
1437 static int smc_setsockopt(struct socket *sock, int level, int optname,
1438 			  char __user *optval, unsigned int optlen)
1439 {
1440 	struct sock *sk = sock->sk;
1441 	struct smc_sock *smc;
1442 	int val, rc;
1443 
1444 	smc = smc_sk(sk);
1445 
1446 	/* generic setsockopts reaching us here always apply to the
1447 	 * CLC socket
1448 	 */
1449 	rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
1450 					   optval, optlen);
1451 	if (smc->clcsock->sk->sk_err) {
1452 		sk->sk_err = smc->clcsock->sk->sk_err;
1453 		sk->sk_error_report(sk);
1454 	}
1455 	if (rc)
1456 		return rc;
1457 
1458 	if (optlen < sizeof(int))
1459 		return -EINVAL;
1460 	if (get_user(val, (int __user *)optval))
1461 		return -EFAULT;
1462 
1463 	lock_sock(sk);
1464 	switch (optname) {
1465 	case TCP_ULP:
1466 	case TCP_FASTOPEN:
1467 	case TCP_FASTOPEN_CONNECT:
1468 	case TCP_FASTOPEN_KEY:
1469 	case TCP_FASTOPEN_NO_COOKIE:
1470 		/* option not supported by SMC */
1471 		if (sk->sk_state == SMC_INIT) {
1472 			smc->use_fallback = true;
1473 		} else {
1474 			if (!smc->use_fallback)
1475 				rc = -EINVAL;
1476 		}
1477 		break;
1478 	case TCP_NODELAY:
1479 		if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1480 			if (val && !smc->use_fallback)
1481 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1482 						 0);
1483 		}
1484 		break;
1485 	case TCP_CORK:
1486 		if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1487 			if (!val && !smc->use_fallback)
1488 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1489 						 0);
1490 		}
1491 		break;
1492 	case TCP_DEFER_ACCEPT:
1493 		smc->sockopt_defer_accept = val;
1494 		break;
1495 	default:
1496 		break;
1497 	}
1498 	release_sock(sk);
1499 
1500 	return rc;
1501 }
1502 
1503 static int smc_getsockopt(struct socket *sock, int level, int optname,
1504 			  char __user *optval, int __user *optlen)
1505 {
1506 	struct smc_sock *smc;
1507 
1508 	smc = smc_sk(sock->sk);
1509 	/* socket options apply to the CLC socket */
1510 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
1511 					     optval, optlen);
1512 }
1513 
1514 static int smc_ioctl(struct socket *sock, unsigned int cmd,
1515 		     unsigned long arg)
1516 {
1517 	union smc_host_cursor cons, urg;
1518 	struct smc_connection *conn;
1519 	struct smc_sock *smc;
1520 	int answ;
1521 
1522 	smc = smc_sk(sock->sk);
1523 	conn = &smc->conn;
1524 	if (smc->use_fallback) {
1525 		if (!smc->clcsock)
1526 			return -EBADF;
1527 		return smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
1528 	}
1529 	lock_sock(&smc->sk);
1530 	switch (cmd) {
1531 	case SIOCINQ: /* same as FIONREAD */
1532 		if (smc->sk.sk_state == SMC_LISTEN) {
1533 			release_sock(&smc->sk);
1534 			return -EINVAL;
1535 		}
1536 		if (smc->sk.sk_state == SMC_INIT ||
1537 		    smc->sk.sk_state == SMC_CLOSED)
1538 			answ = 0;
1539 		else
1540 			answ = atomic_read(&smc->conn.bytes_to_rcv);
1541 		break;
1542 	case SIOCOUTQ:
1543 		/* output queue size (not send + not acked) */
1544 		if (smc->sk.sk_state == SMC_LISTEN) {
1545 			release_sock(&smc->sk);
1546 			return -EINVAL;
1547 		}
1548 		if (smc->sk.sk_state == SMC_INIT ||
1549 		    smc->sk.sk_state == SMC_CLOSED)
1550 			answ = 0;
1551 		else
1552 			answ = smc->conn.sndbuf_desc->len -
1553 					atomic_read(&smc->conn.sndbuf_space);
1554 		break;
1555 	case SIOCOUTQNSD:
1556 		/* output queue size (not send only) */
1557 		if (smc->sk.sk_state == SMC_LISTEN) {
1558 			release_sock(&smc->sk);
1559 			return -EINVAL;
1560 		}
1561 		if (smc->sk.sk_state == SMC_INIT ||
1562 		    smc->sk.sk_state == SMC_CLOSED)
1563 			answ = 0;
1564 		else
1565 			answ = smc_tx_prepared_sends(&smc->conn);
1566 		break;
1567 	case SIOCATMARK:
1568 		if (smc->sk.sk_state == SMC_LISTEN) {
1569 			release_sock(&smc->sk);
1570 			return -EINVAL;
1571 		}
1572 		if (smc->sk.sk_state == SMC_INIT ||
1573 		    smc->sk.sk_state == SMC_CLOSED) {
1574 			answ = 0;
1575 		} else {
1576 			smc_curs_write(&cons,
1577 			       smc_curs_read(&conn->local_tx_ctrl.cons, conn),
1578 				       conn);
1579 			smc_curs_write(&urg,
1580 				       smc_curs_read(&conn->urg_curs, conn),
1581 				       conn);
1582 			answ = smc_curs_diff(conn->rmb_desc->len,
1583 					     &cons, &urg) == 1;
1584 		}
1585 		break;
1586 	default:
1587 		release_sock(&smc->sk);
1588 		return -ENOIOCTLCMD;
1589 	}
1590 	release_sock(&smc->sk);
1591 
1592 	return put_user(answ, (int __user *)arg);
1593 }
1594 
1595 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
1596 			    int offset, size_t size, int flags)
1597 {
1598 	struct sock *sk = sock->sk;
1599 	struct smc_sock *smc;
1600 	int rc = -EPIPE;
1601 
1602 	smc = smc_sk(sk);
1603 	lock_sock(sk);
1604 	if (sk->sk_state != SMC_ACTIVE) {
1605 		release_sock(sk);
1606 		goto out;
1607 	}
1608 	release_sock(sk);
1609 	if (smc->use_fallback)
1610 		rc = kernel_sendpage(smc->clcsock, page, offset,
1611 				     size, flags);
1612 	else
1613 		rc = sock_no_sendpage(sock, page, offset, size, flags);
1614 
1615 out:
1616 	return rc;
1617 }
1618 
1619 /* Map the affected portions of the rmbe into an spd, note the number of bytes
1620  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
1621  * updates till whenever a respective page has been fully processed.
1622  * Note that subsequent recv() calls have to wait till all splice() processing
1623  * completed.
1624  */
1625 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
1626 			       struct pipe_inode_info *pipe, size_t len,
1627 			       unsigned int flags)
1628 {
1629 	struct sock *sk = sock->sk;
1630 	struct smc_sock *smc;
1631 	int rc = -ENOTCONN;
1632 
1633 	smc = smc_sk(sk);
1634 	lock_sock(sk);
1635 
1636 	if (sk->sk_state == SMC_INIT ||
1637 	    sk->sk_state == SMC_LISTEN ||
1638 	    sk->sk_state == SMC_CLOSED)
1639 		goto out;
1640 
1641 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1642 		rc = 0;
1643 		goto out;
1644 	}
1645 
1646 	if (smc->use_fallback) {
1647 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
1648 						    pipe, len, flags);
1649 	} else {
1650 		if (*ppos) {
1651 			rc = -ESPIPE;
1652 			goto out;
1653 		}
1654 		if (flags & SPLICE_F_NONBLOCK)
1655 			flags = MSG_DONTWAIT;
1656 		else
1657 			flags = 0;
1658 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
1659 	}
1660 out:
1661 	release_sock(sk);
1662 
1663 	return rc;
1664 }
1665 
1666 /* must look like tcp */
1667 static const struct proto_ops smc_sock_ops = {
1668 	.family		= PF_SMC,
1669 	.owner		= THIS_MODULE,
1670 	.release	= smc_release,
1671 	.bind		= smc_bind,
1672 	.connect	= smc_connect,
1673 	.socketpair	= sock_no_socketpair,
1674 	.accept		= smc_accept,
1675 	.getname	= smc_getname,
1676 	.poll		= smc_poll,
1677 	.ioctl		= smc_ioctl,
1678 	.listen		= smc_listen,
1679 	.shutdown	= smc_shutdown,
1680 	.setsockopt	= smc_setsockopt,
1681 	.getsockopt	= smc_getsockopt,
1682 	.sendmsg	= smc_sendmsg,
1683 	.recvmsg	= smc_recvmsg,
1684 	.mmap		= sock_no_mmap,
1685 	.sendpage	= smc_sendpage,
1686 	.splice_read	= smc_splice_read,
1687 };
1688 
1689 static int smc_create(struct net *net, struct socket *sock, int protocol,
1690 		      int kern)
1691 {
1692 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
1693 	struct smc_sock *smc;
1694 	struct sock *sk;
1695 	int rc;
1696 
1697 	rc = -ESOCKTNOSUPPORT;
1698 	if (sock->type != SOCK_STREAM)
1699 		goto out;
1700 
1701 	rc = -EPROTONOSUPPORT;
1702 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
1703 		goto out;
1704 
1705 	rc = -ENOBUFS;
1706 	sock->ops = &smc_sock_ops;
1707 	sk = smc_sock_alloc(net, sock, protocol);
1708 	if (!sk)
1709 		goto out;
1710 
1711 	/* create internal TCP socket for CLC handshake and fallback */
1712 	smc = smc_sk(sk);
1713 	smc->use_fallback = false; /* assume rdma capability first */
1714 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
1715 			      &smc->clcsock);
1716 	if (rc) {
1717 		sk_common_release(sk);
1718 		goto out;
1719 	}
1720 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
1721 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
1722 
1723 out:
1724 	return rc;
1725 }
1726 
1727 static const struct net_proto_family smc_sock_family_ops = {
1728 	.family	= PF_SMC,
1729 	.owner	= THIS_MODULE,
1730 	.create	= smc_create,
1731 };
1732 
1733 static int __init smc_init(void)
1734 {
1735 	int rc;
1736 
1737 	rc = smc_pnet_init();
1738 	if (rc)
1739 		return rc;
1740 
1741 	rc = smc_llc_init();
1742 	if (rc) {
1743 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
1744 		goto out_pnet;
1745 	}
1746 
1747 	rc = smc_cdc_init();
1748 	if (rc) {
1749 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
1750 		goto out_pnet;
1751 	}
1752 
1753 	rc = proto_register(&smc_proto, 1);
1754 	if (rc) {
1755 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
1756 		goto out_pnet;
1757 	}
1758 
1759 	rc = proto_register(&smc_proto6, 1);
1760 	if (rc) {
1761 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
1762 		goto out_proto;
1763 	}
1764 
1765 	rc = sock_register(&smc_sock_family_ops);
1766 	if (rc) {
1767 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
1768 		goto out_proto6;
1769 	}
1770 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
1771 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
1772 
1773 	rc = smc_ib_register_client();
1774 	if (rc) {
1775 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
1776 		goto out_sock;
1777 	}
1778 
1779 	static_branch_enable(&tcp_have_smc);
1780 	return 0;
1781 
1782 out_sock:
1783 	sock_unregister(PF_SMC);
1784 out_proto6:
1785 	proto_unregister(&smc_proto6);
1786 out_proto:
1787 	proto_unregister(&smc_proto);
1788 out_pnet:
1789 	smc_pnet_exit();
1790 	return rc;
1791 }
1792 
1793 static void __exit smc_exit(void)
1794 {
1795 	smc_core_exit();
1796 	static_branch_disable(&tcp_have_smc);
1797 	smc_ib_unregister_client();
1798 	sock_unregister(PF_SMC);
1799 	proto_unregister(&smc_proto6);
1800 	proto_unregister(&smc_proto);
1801 	smc_pnet_exit();
1802 }
1803 
1804 module_init(smc_init);
1805 module_exit(smc_exit);
1806 
1807 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
1808 MODULE_DESCRIPTION("smc socket address family");
1809 MODULE_LICENSE("GPL");
1810 MODULE_ALIAS_NETPROTO(PF_SMC);
1811