xref: /openbmc/linux/net/smc/af_smc.c (revision dd5b2498)
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 #include <linux/if_vlan.h>
27 
28 #include <net/sock.h>
29 #include <net/tcp.h>
30 #include <net/smc.h>
31 #include <asm/ioctls.h>
32 
33 #include <net/net_namespace.h>
34 #include <net/netns/generic.h>
35 #include "smc_netns.h"
36 
37 #include "smc.h"
38 #include "smc_clc.h"
39 #include "smc_llc.h"
40 #include "smc_cdc.h"
41 #include "smc_core.h"
42 #include "smc_ib.h"
43 #include "smc_ism.h"
44 #include "smc_pnet.h"
45 #include "smc_tx.h"
46 #include "smc_rx.h"
47 #include "smc_close.h"
48 
49 static DEFINE_MUTEX(smc_server_lgr_pending);	/* serialize link group
50 						 * creation on server
51 						 */
52 static DEFINE_MUTEX(smc_client_lgr_pending);	/* serialize link group
53 						 * creation on client
54 						 */
55 
56 static void smc_tcp_listen_work(struct work_struct *);
57 static void smc_connect_work(struct work_struct *);
58 
59 static void smc_set_keepalive(struct sock *sk, int val)
60 {
61 	struct smc_sock *smc = smc_sk(sk);
62 
63 	smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
64 }
65 
66 static struct smc_hashinfo smc_v4_hashinfo = {
67 	.lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
68 };
69 
70 static struct smc_hashinfo smc_v6_hashinfo = {
71 	.lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
72 };
73 
74 int smc_hash_sk(struct sock *sk)
75 {
76 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
77 	struct hlist_head *head;
78 
79 	head = &h->ht;
80 
81 	write_lock_bh(&h->lock);
82 	sk_add_node(sk, head);
83 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
84 	write_unlock_bh(&h->lock);
85 
86 	return 0;
87 }
88 EXPORT_SYMBOL_GPL(smc_hash_sk);
89 
90 void smc_unhash_sk(struct sock *sk)
91 {
92 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
93 
94 	write_lock_bh(&h->lock);
95 	if (sk_del_node_init(sk))
96 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
97 	write_unlock_bh(&h->lock);
98 }
99 EXPORT_SYMBOL_GPL(smc_unhash_sk);
100 
101 struct proto smc_proto = {
102 	.name		= "SMC",
103 	.owner		= THIS_MODULE,
104 	.keepalive	= smc_set_keepalive,
105 	.hash		= smc_hash_sk,
106 	.unhash		= smc_unhash_sk,
107 	.obj_size	= sizeof(struct smc_sock),
108 	.h.smc_hash	= &smc_v4_hashinfo,
109 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
110 };
111 EXPORT_SYMBOL_GPL(smc_proto);
112 
113 struct proto smc_proto6 = {
114 	.name		= "SMC6",
115 	.owner		= THIS_MODULE,
116 	.keepalive	= smc_set_keepalive,
117 	.hash		= smc_hash_sk,
118 	.unhash		= smc_unhash_sk,
119 	.obj_size	= sizeof(struct smc_sock),
120 	.h.smc_hash	= &smc_v6_hashinfo,
121 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
122 };
123 EXPORT_SYMBOL_GPL(smc_proto6);
124 
125 static int smc_release(struct socket *sock)
126 {
127 	struct sock *sk = sock->sk;
128 	struct smc_sock *smc;
129 	int rc = 0;
130 
131 	if (!sk)
132 		goto out;
133 
134 	smc = smc_sk(sk);
135 
136 	/* cleanup for a dangling non-blocking connect */
137 	if (smc->connect_nonblock && sk->sk_state == SMC_INIT)
138 		tcp_abort(smc->clcsock->sk, ECONNABORTED);
139 	flush_work(&smc->connect_work);
140 
141 	if (sk->sk_state == SMC_LISTEN)
142 		/* smc_close_non_accepted() is called and acquires
143 		 * sock lock for child sockets again
144 		 */
145 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
146 	else
147 		lock_sock(sk);
148 
149 	if (!smc->use_fallback) {
150 		rc = smc_close_active(smc);
151 		sock_set_flag(sk, SOCK_DEAD);
152 		sk->sk_shutdown |= SHUTDOWN_MASK;
153 	} else {
154 		if (sk->sk_state != SMC_LISTEN && sk->sk_state != SMC_INIT)
155 			sock_put(sk); /* passive closing */
156 		if (sk->sk_state == SMC_LISTEN) {
157 			/* wake up clcsock accept */
158 			rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
159 		}
160 		sk->sk_state = SMC_CLOSED;
161 		sk->sk_state_change(sk);
162 	}
163 
164 	sk->sk_prot->unhash(sk);
165 
166 	if (sk->sk_state == SMC_CLOSED) {
167 		if (smc->clcsock) {
168 			mutex_lock(&smc->clcsock_release_lock);
169 			sock_release(smc->clcsock);
170 			smc->clcsock = NULL;
171 			mutex_unlock(&smc->clcsock_release_lock);
172 		}
173 		if (!smc->use_fallback)
174 			smc_conn_free(&smc->conn);
175 	}
176 
177 	/* detach socket */
178 	sock_orphan(sk);
179 	sock->sk = NULL;
180 	release_sock(sk);
181 
182 	sock_put(sk); /* final sock_put */
183 out:
184 	return rc;
185 }
186 
187 static void smc_destruct(struct sock *sk)
188 {
189 	if (sk->sk_state != SMC_CLOSED)
190 		return;
191 	if (!sock_flag(sk, SOCK_DEAD))
192 		return;
193 
194 	sk_refcnt_debug_dec(sk);
195 }
196 
197 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
198 				   int protocol)
199 {
200 	struct smc_sock *smc;
201 	struct proto *prot;
202 	struct sock *sk;
203 
204 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
205 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
206 	if (!sk)
207 		return NULL;
208 
209 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
210 	sk->sk_state = SMC_INIT;
211 	sk->sk_destruct = smc_destruct;
212 	sk->sk_protocol = protocol;
213 	smc = smc_sk(sk);
214 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
215 	INIT_WORK(&smc->connect_work, smc_connect_work);
216 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
217 	INIT_LIST_HEAD(&smc->accept_q);
218 	spin_lock_init(&smc->accept_q_lock);
219 	spin_lock_init(&smc->conn.send_lock);
220 	sk->sk_prot->hash(sk);
221 	sk_refcnt_debug_inc(sk);
222 	mutex_init(&smc->clcsock_release_lock);
223 
224 	return sk;
225 }
226 
227 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
228 		    int addr_len)
229 {
230 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
231 	struct sock *sk = sock->sk;
232 	struct smc_sock *smc;
233 	int rc;
234 
235 	smc = smc_sk(sk);
236 
237 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
238 	rc = -EINVAL;
239 	if (addr_len < sizeof(struct sockaddr_in))
240 		goto out;
241 
242 	rc = -EAFNOSUPPORT;
243 	if (addr->sin_family != AF_INET &&
244 	    addr->sin_family != AF_INET6 &&
245 	    addr->sin_family != AF_UNSPEC)
246 		goto out;
247 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
248 	if (addr->sin_family == AF_UNSPEC &&
249 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
250 		goto out;
251 
252 	lock_sock(sk);
253 
254 	/* Check if socket is already active */
255 	rc = -EINVAL;
256 	if (sk->sk_state != SMC_INIT)
257 		goto out_rel;
258 
259 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
260 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
261 
262 out_rel:
263 	release_sock(sk);
264 out:
265 	return rc;
266 }
267 
268 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
269 				   unsigned long mask)
270 {
271 	/* options we don't get control via setsockopt for */
272 	nsk->sk_type = osk->sk_type;
273 	nsk->sk_sndbuf = osk->sk_sndbuf;
274 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
275 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
276 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
277 	nsk->sk_mark = osk->sk_mark;
278 	nsk->sk_priority = osk->sk_priority;
279 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
280 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
281 	nsk->sk_err = osk->sk_err;
282 
283 	nsk->sk_flags &= ~mask;
284 	nsk->sk_flags |= osk->sk_flags & mask;
285 }
286 
287 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
288 			     (1UL << SOCK_KEEPOPEN) | \
289 			     (1UL << SOCK_LINGER) | \
290 			     (1UL << SOCK_BROADCAST) | \
291 			     (1UL << SOCK_TIMESTAMP) | \
292 			     (1UL << SOCK_DBG) | \
293 			     (1UL << SOCK_RCVTSTAMP) | \
294 			     (1UL << SOCK_RCVTSTAMPNS) | \
295 			     (1UL << SOCK_LOCALROUTE) | \
296 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
297 			     (1UL << SOCK_RXQ_OVFL) | \
298 			     (1UL << SOCK_WIFI_STATUS) | \
299 			     (1UL << SOCK_NOFCS) | \
300 			     (1UL << SOCK_FILTER_LOCKED) | \
301 			     (1UL << SOCK_TSTAMP_NEW))
302 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
303  * clc socket (since smc is not called for these options from net/core)
304  */
305 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
306 {
307 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
308 }
309 
310 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
311 			     (1UL << SOCK_KEEPOPEN) | \
312 			     (1UL << SOCK_LINGER) | \
313 			     (1UL << SOCK_DBG))
314 /* copy only settings and flags relevant for smc from clc to smc socket */
315 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
316 {
317 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
318 }
319 
320 /* register a new rmb, send confirm_rkey msg to register with peer */
321 static int smc_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc,
322 		       bool conf_rkey)
323 {
324 	if (!rmb_desc->wr_reg) {
325 		/* register memory region for new rmb */
326 		if (smc_wr_reg_send(link, rmb_desc->mr_rx[SMC_SINGLE_LINK])) {
327 			rmb_desc->regerr = 1;
328 			return -EFAULT;
329 		}
330 		rmb_desc->wr_reg = 1;
331 	}
332 	if (!conf_rkey)
333 		return 0;
334 	/* exchange confirm_rkey msg with peer */
335 	if (smc_llc_do_confirm_rkey(link, rmb_desc)) {
336 		rmb_desc->regerr = 1;
337 		return -EFAULT;
338 	}
339 	return 0;
340 }
341 
342 static int smc_clnt_conf_first_link(struct smc_sock *smc)
343 {
344 	struct net *net = sock_net(smc->clcsock->sk);
345 	struct smc_link_group *lgr = smc->conn.lgr;
346 	struct smc_link *link;
347 	int rest;
348 	int rc;
349 
350 	link = &lgr->lnk[SMC_SINGLE_LINK];
351 	/* receive CONFIRM LINK request from server over RoCE fabric */
352 	rest = wait_for_completion_interruptible_timeout(
353 		&link->llc_confirm,
354 		SMC_LLC_WAIT_FIRST_TIME);
355 	if (rest <= 0) {
356 		struct smc_clc_msg_decline dclc;
357 
358 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
359 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
360 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
361 	}
362 
363 	if (link->llc_confirm_rc)
364 		return SMC_CLC_DECL_RMBE_EC;
365 
366 	rc = smc_ib_modify_qp_rts(link);
367 	if (rc)
368 		return SMC_CLC_DECL_ERR_RDYLNK;
369 
370 	smc_wr_remember_qp_attr(link);
371 
372 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
373 		return SMC_CLC_DECL_ERR_REGRMB;
374 
375 	/* send CONFIRM LINK response over RoCE fabric */
376 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
377 	if (rc < 0)
378 		return SMC_CLC_DECL_TIMEOUT_CL;
379 
380 	/* receive ADD LINK request from server over RoCE fabric */
381 	rest = wait_for_completion_interruptible_timeout(&link->llc_add,
382 							 SMC_LLC_WAIT_TIME);
383 	if (rest <= 0) {
384 		struct smc_clc_msg_decline dclc;
385 
386 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
387 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
388 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_AL : rc;
389 	}
390 
391 	/* send add link reject message, only one link supported for now */
392 	rc = smc_llc_send_add_link(link,
393 				   link->smcibdev->mac[link->ibport - 1],
394 				   link->gid, SMC_LLC_RESP);
395 	if (rc < 0)
396 		return SMC_CLC_DECL_TIMEOUT_AL;
397 
398 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
399 
400 	return 0;
401 }
402 
403 static void smcr_conn_save_peer_info(struct smc_sock *smc,
404 				     struct smc_clc_msg_accept_confirm *clc)
405 {
406 	int bufsize = smc_uncompress_bufsize(clc->rmbe_size);
407 
408 	smc->conn.peer_rmbe_idx = clc->rmbe_idx;
409 	smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
410 	smc->conn.peer_rmbe_size = bufsize;
411 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
412 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
413 }
414 
415 static void smcd_conn_save_peer_info(struct smc_sock *smc,
416 				     struct smc_clc_msg_accept_confirm *clc)
417 {
418 	int bufsize = smc_uncompress_bufsize(clc->dmbe_size);
419 
420 	smc->conn.peer_rmbe_idx = clc->dmbe_idx;
421 	smc->conn.peer_token = clc->token;
422 	/* msg header takes up space in the buffer */
423 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
424 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
425 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
426 }
427 
428 static void smc_conn_save_peer_info(struct smc_sock *smc,
429 				    struct smc_clc_msg_accept_confirm *clc)
430 {
431 	if (smc->conn.lgr->is_smcd)
432 		smcd_conn_save_peer_info(smc, clc);
433 	else
434 		smcr_conn_save_peer_info(smc, clc);
435 }
436 
437 static void smc_link_save_peer_info(struct smc_link *link,
438 				    struct smc_clc_msg_accept_confirm *clc)
439 {
440 	link->peer_qpn = ntoh24(clc->qpn);
441 	memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
442 	memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
443 	link->peer_psn = ntoh24(clc->psn);
444 	link->peer_mtu = clc->qp_mtu;
445 }
446 
447 /* fall back during connect */
448 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
449 {
450 	smc->use_fallback = true;
451 	smc->fallback_rsn = reason_code;
452 	smc_copy_sock_settings_to_clc(smc);
453 	smc->connect_nonblock = 0;
454 	if (smc->sk.sk_state == SMC_INIT)
455 		smc->sk.sk_state = SMC_ACTIVE;
456 	return 0;
457 }
458 
459 /* decline and fall back during connect */
460 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code)
461 {
462 	int rc;
463 
464 	if (reason_code < 0) { /* error, fallback is not possible */
465 		if (smc->sk.sk_state == SMC_INIT)
466 			sock_put(&smc->sk); /* passive closing */
467 		return reason_code;
468 	}
469 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
470 		rc = smc_clc_send_decline(smc, reason_code);
471 		if (rc < 0) {
472 			if (smc->sk.sk_state == SMC_INIT)
473 				sock_put(&smc->sk); /* passive closing */
474 			return rc;
475 		}
476 	}
477 	return smc_connect_fallback(smc, reason_code);
478 }
479 
480 /* abort connecting */
481 static int smc_connect_abort(struct smc_sock *smc, int reason_code,
482 			     int local_contact)
483 {
484 	if (local_contact == SMC_FIRST_CONTACT)
485 		smc_lgr_forget(smc->conn.lgr);
486 	if (smc->conn.lgr->is_smcd)
487 		/* there is only one lgr role for SMC-D; use server lock */
488 		mutex_unlock(&smc_server_lgr_pending);
489 	else
490 		mutex_unlock(&smc_client_lgr_pending);
491 
492 	smc_conn_free(&smc->conn);
493 	smc->connect_nonblock = 0;
494 	return reason_code;
495 }
496 
497 /* check if there is a rdma device available for this connection. */
498 /* called for connect and listen */
499 static int smc_find_rdma_device(struct smc_sock *smc, struct smc_init_info *ini)
500 {
501 	/* PNET table look up: search active ib_device and port
502 	 * within same PNETID that also contains the ethernet device
503 	 * used for the internal TCP socket
504 	 */
505 	smc_pnet_find_roce_resource(smc->clcsock->sk, ini);
506 	if (!ini->ib_dev)
507 		return SMC_CLC_DECL_NOSMCRDEV;
508 	return 0;
509 }
510 
511 /* check if there is an ISM device available for this connection. */
512 /* called for connect and listen */
513 static int smc_find_ism_device(struct smc_sock *smc, struct smc_init_info *ini)
514 {
515 	/* Find ISM device with same PNETID as connecting interface  */
516 	smc_pnet_find_ism_resource(smc->clcsock->sk, ini);
517 	if (!ini->ism_dev)
518 		return SMC_CLC_DECL_NOSMCDDEV;
519 	return 0;
520 }
521 
522 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
523 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
524 				      struct smc_init_info *ini)
525 {
526 	if (ini->vlan_id && smc_ism_get_vlan(ini->ism_dev, ini->vlan_id))
527 		return SMC_CLC_DECL_ISMVLANERR;
528 	return 0;
529 }
530 
531 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
532  * used, the VLAN ID will be registered again during the connection setup.
533  */
534 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc, bool is_smcd,
535 					struct smc_init_info *ini)
536 {
537 	if (!is_smcd)
538 		return 0;
539 	if (ini->vlan_id && smc_ism_put_vlan(ini->ism_dev, ini->vlan_id))
540 		return SMC_CLC_DECL_CNFERR;
541 	return 0;
542 }
543 
544 /* CLC handshake during connect */
545 static int smc_connect_clc(struct smc_sock *smc, int smc_type,
546 			   struct smc_clc_msg_accept_confirm *aclc,
547 			   struct smc_init_info *ini)
548 {
549 	int rc = 0;
550 
551 	/* do inband token exchange */
552 	rc = smc_clc_send_proposal(smc, smc_type, ini);
553 	if (rc)
554 		return rc;
555 	/* receive SMC Accept CLC message */
556 	return smc_clc_wait_msg(smc, aclc, sizeof(*aclc), SMC_CLC_ACCEPT,
557 				CLC_WAIT_TIME);
558 }
559 
560 /* setup for RDMA connection of client */
561 static int smc_connect_rdma(struct smc_sock *smc,
562 			    struct smc_clc_msg_accept_confirm *aclc,
563 			    struct smc_init_info *ini)
564 {
565 	struct smc_link *link;
566 	int reason_code = 0;
567 
568 	ini->is_smcd = false;
569 	ini->ib_lcl = &aclc->lcl;
570 	ini->ib_clcqpn = ntoh24(aclc->qpn);
571 	ini->srv_first_contact = aclc->hdr.flag;
572 
573 	mutex_lock(&smc_client_lgr_pending);
574 	reason_code = smc_conn_create(smc, ini);
575 	if (reason_code) {
576 		mutex_unlock(&smc_client_lgr_pending);
577 		return reason_code;
578 	}
579 	link = &smc->conn.lgr->lnk[SMC_SINGLE_LINK];
580 
581 	smc_conn_save_peer_info(smc, aclc);
582 
583 	/* create send buffer and rmb */
584 	if (smc_buf_create(smc, false))
585 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM,
586 					 ini->cln_first_contact);
587 
588 	if (ini->cln_first_contact == SMC_FIRST_CONTACT)
589 		smc_link_save_peer_info(link, aclc);
590 
591 	if (smc_rmb_rtoken_handling(&smc->conn, aclc))
592 		return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RTOK,
593 					 ini->cln_first_contact);
594 
595 	smc_close_init(smc);
596 	smc_rx_init(smc);
597 
598 	if (ini->cln_first_contact == SMC_FIRST_CONTACT) {
599 		if (smc_ib_ready_link(link))
600 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RDYLNK,
601 						 ini->cln_first_contact);
602 	} else {
603 		if (smc_reg_rmb(link, smc->conn.rmb_desc, true))
604 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_REGRMB,
605 						 ini->cln_first_contact);
606 	}
607 	smc_rmb_sync_sg_for_device(&smc->conn);
608 
609 	reason_code = smc_clc_send_confirm(smc);
610 	if (reason_code)
611 		return smc_connect_abort(smc, reason_code,
612 					 ini->cln_first_contact);
613 
614 	smc_tx_init(smc);
615 
616 	if (ini->cln_first_contact == SMC_FIRST_CONTACT) {
617 		/* QP confirmation over RoCE fabric */
618 		reason_code = smc_clnt_conf_first_link(smc);
619 		if (reason_code)
620 			return smc_connect_abort(smc, reason_code,
621 						 ini->cln_first_contact);
622 	}
623 	mutex_unlock(&smc_client_lgr_pending);
624 
625 	smc_copy_sock_settings_to_clc(smc);
626 	smc->connect_nonblock = 0;
627 	if (smc->sk.sk_state == SMC_INIT)
628 		smc->sk.sk_state = SMC_ACTIVE;
629 
630 	return 0;
631 }
632 
633 /* setup for ISM connection of client */
634 static int smc_connect_ism(struct smc_sock *smc,
635 			   struct smc_clc_msg_accept_confirm *aclc,
636 			   struct smc_init_info *ini)
637 {
638 	int rc = 0;
639 
640 	ini->is_smcd = true;
641 	ini->ism_gid = aclc->gid;
642 	ini->srv_first_contact = aclc->hdr.flag;
643 
644 	/* there is only one lgr role for SMC-D; use server lock */
645 	mutex_lock(&smc_server_lgr_pending);
646 	rc = smc_conn_create(smc, ini);
647 	if (rc) {
648 		mutex_unlock(&smc_server_lgr_pending);
649 		return rc;
650 	}
651 
652 	/* Create send and receive buffers */
653 	if (smc_buf_create(smc, true))
654 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM,
655 					 ini->cln_first_contact);
656 
657 	smc_conn_save_peer_info(smc, aclc);
658 	smc_close_init(smc);
659 	smc_rx_init(smc);
660 	smc_tx_init(smc);
661 
662 	rc = smc_clc_send_confirm(smc);
663 	if (rc)
664 		return smc_connect_abort(smc, rc, ini->cln_first_contact);
665 	mutex_unlock(&smc_server_lgr_pending);
666 
667 	smc_copy_sock_settings_to_clc(smc);
668 	smc->connect_nonblock = 0;
669 	if (smc->sk.sk_state == SMC_INIT)
670 		smc->sk.sk_state = SMC_ACTIVE;
671 
672 	return 0;
673 }
674 
675 /* perform steps before actually connecting */
676 static int __smc_connect(struct smc_sock *smc)
677 {
678 	bool ism_supported = false, rdma_supported = false;
679 	struct smc_clc_msg_accept_confirm aclc;
680 	struct smc_init_info ini = {0};
681 	int smc_type;
682 	int rc = 0;
683 
684 	sock_hold(&smc->sk); /* sock put in passive closing */
685 
686 	if (smc->use_fallback)
687 		return smc_connect_fallback(smc, smc->fallback_rsn);
688 
689 	/* if peer has not signalled SMC-capability, fall back */
690 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
691 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
692 
693 	/* IPSec connections opt out of SMC-R optimizations */
694 	if (using_ipsec(smc))
695 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC);
696 
697 	/* get vlan id from IP device */
698 	if (smc_vlan_by_tcpsk(smc->clcsock, &ini))
699 		return smc_connect_decline_fallback(smc,
700 						    SMC_CLC_DECL_GETVLANERR);
701 
702 	/* check if there is an ism device available */
703 	if (!smc_find_ism_device(smc, &ini) &&
704 	    !smc_connect_ism_vlan_setup(smc, &ini)) {
705 		/* ISM is supported for this connection */
706 		ism_supported = true;
707 		smc_type = SMC_TYPE_D;
708 	}
709 
710 	/* check if there is a rdma device available */
711 	if (!smc_find_rdma_device(smc, &ini)) {
712 		/* RDMA is supported for this connection */
713 		rdma_supported = true;
714 		if (ism_supported)
715 			smc_type = SMC_TYPE_B; /* both */
716 		else
717 			smc_type = SMC_TYPE_R; /* only RDMA */
718 	}
719 
720 	/* if neither ISM nor RDMA are supported, fallback */
721 	if (!rdma_supported && !ism_supported)
722 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_NOSMCDEV);
723 
724 	/* perform CLC handshake */
725 	rc = smc_connect_clc(smc, smc_type, &aclc, &ini);
726 	if (rc) {
727 		smc_connect_ism_vlan_cleanup(smc, ism_supported, &ini);
728 		return smc_connect_decline_fallback(smc, rc);
729 	}
730 
731 	/* depending on previous steps, connect using rdma or ism */
732 	if (rdma_supported && aclc.hdr.path == SMC_TYPE_R)
733 		rc = smc_connect_rdma(smc, &aclc, &ini);
734 	else if (ism_supported && aclc.hdr.path == SMC_TYPE_D)
735 		rc = smc_connect_ism(smc, &aclc, &ini);
736 	else
737 		rc = SMC_CLC_DECL_MODEUNSUPP;
738 	if (rc) {
739 		smc_connect_ism_vlan_cleanup(smc, ism_supported, &ini);
740 		return smc_connect_decline_fallback(smc, rc);
741 	}
742 
743 	smc_connect_ism_vlan_cleanup(smc, ism_supported, &ini);
744 	return 0;
745 }
746 
747 static void smc_connect_work(struct work_struct *work)
748 {
749 	struct smc_sock *smc = container_of(work, struct smc_sock,
750 					    connect_work);
751 	long timeo = smc->sk.sk_sndtimeo;
752 	int rc = 0;
753 
754 	if (!timeo)
755 		timeo = MAX_SCHEDULE_TIMEOUT;
756 	lock_sock(smc->clcsock->sk);
757 	if (smc->clcsock->sk->sk_err) {
758 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
759 	} else if ((1 << smc->clcsock->sk->sk_state) &
760 					(TCPF_SYN_SENT | TCP_SYN_RECV)) {
761 		rc = sk_stream_wait_connect(smc->clcsock->sk, &timeo);
762 		if ((rc == -EPIPE) &&
763 		    ((1 << smc->clcsock->sk->sk_state) &
764 					(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))
765 			rc = 0;
766 	}
767 	release_sock(smc->clcsock->sk);
768 	lock_sock(&smc->sk);
769 	if (rc != 0 || smc->sk.sk_err) {
770 		smc->sk.sk_state = SMC_CLOSED;
771 		if (rc == -EPIPE || rc == -EAGAIN)
772 			smc->sk.sk_err = EPIPE;
773 		else if (signal_pending(current))
774 			smc->sk.sk_err = -sock_intr_errno(timeo);
775 		goto out;
776 	}
777 
778 	rc = __smc_connect(smc);
779 	if (rc < 0)
780 		smc->sk.sk_err = -rc;
781 
782 out:
783 	if (smc->sk.sk_err)
784 		smc->sk.sk_state_change(&smc->sk);
785 	else
786 		smc->sk.sk_write_space(&smc->sk);
787 	release_sock(&smc->sk);
788 }
789 
790 static int smc_connect(struct socket *sock, struct sockaddr *addr,
791 		       int alen, int flags)
792 {
793 	struct sock *sk = sock->sk;
794 	struct smc_sock *smc;
795 	int rc = -EINVAL;
796 
797 	smc = smc_sk(sk);
798 
799 	/* separate smc parameter checking to be safe */
800 	if (alen < sizeof(addr->sa_family))
801 		goto out_err;
802 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
803 		goto out_err;
804 
805 	lock_sock(sk);
806 	switch (sk->sk_state) {
807 	default:
808 		goto out;
809 	case SMC_ACTIVE:
810 		rc = -EISCONN;
811 		goto out;
812 	case SMC_INIT:
813 		rc = 0;
814 		break;
815 	}
816 
817 	smc_copy_sock_settings_to_clc(smc);
818 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
819 	if (smc->connect_nonblock) {
820 		rc = -EALREADY;
821 		goto out;
822 	}
823 	rc = kernel_connect(smc->clcsock, addr, alen, flags);
824 	if (rc && rc != -EINPROGRESS)
825 		goto out;
826 	if (flags & O_NONBLOCK) {
827 		if (schedule_work(&smc->connect_work))
828 			smc->connect_nonblock = 1;
829 		rc = -EINPROGRESS;
830 	} else {
831 		rc = __smc_connect(smc);
832 		if (rc < 0)
833 			goto out;
834 		else
835 			rc = 0; /* success cases including fallback */
836 	}
837 
838 out:
839 	release_sock(sk);
840 out_err:
841 	return rc;
842 }
843 
844 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
845 {
846 	struct socket *new_clcsock = NULL;
847 	struct sock *lsk = &lsmc->sk;
848 	struct sock *new_sk;
849 	int rc = -EINVAL;
850 
851 	release_sock(lsk);
852 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
853 	if (!new_sk) {
854 		rc = -ENOMEM;
855 		lsk->sk_err = ENOMEM;
856 		*new_smc = NULL;
857 		lock_sock(lsk);
858 		goto out;
859 	}
860 	*new_smc = smc_sk(new_sk);
861 
862 	mutex_lock(&lsmc->clcsock_release_lock);
863 	if (lsmc->clcsock)
864 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
865 	mutex_unlock(&lsmc->clcsock_release_lock);
866 	lock_sock(lsk);
867 	if  (rc < 0)
868 		lsk->sk_err = -rc;
869 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
870 		if (new_clcsock)
871 			sock_release(new_clcsock);
872 		new_sk->sk_state = SMC_CLOSED;
873 		sock_set_flag(new_sk, SOCK_DEAD);
874 		new_sk->sk_prot->unhash(new_sk);
875 		sock_put(new_sk); /* final */
876 		*new_smc = NULL;
877 		goto out;
878 	}
879 
880 	(*new_smc)->clcsock = new_clcsock;
881 out:
882 	return rc;
883 }
884 
885 /* add a just created sock to the accept queue of the listen sock as
886  * candidate for a following socket accept call from user space
887  */
888 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
889 {
890 	struct smc_sock *par = smc_sk(parent);
891 
892 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
893 	spin_lock(&par->accept_q_lock);
894 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
895 	spin_unlock(&par->accept_q_lock);
896 	sk_acceptq_added(parent);
897 }
898 
899 /* remove a socket from the accept queue of its parental listening socket */
900 static void smc_accept_unlink(struct sock *sk)
901 {
902 	struct smc_sock *par = smc_sk(sk)->listen_smc;
903 
904 	spin_lock(&par->accept_q_lock);
905 	list_del_init(&smc_sk(sk)->accept_q);
906 	spin_unlock(&par->accept_q_lock);
907 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
908 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
909 }
910 
911 /* remove a sock from the accept queue to bind it to a new socket created
912  * for a socket accept call from user space
913  */
914 struct sock *smc_accept_dequeue(struct sock *parent,
915 				struct socket *new_sock)
916 {
917 	struct smc_sock *isk, *n;
918 	struct sock *new_sk;
919 
920 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
921 		new_sk = (struct sock *)isk;
922 
923 		smc_accept_unlink(new_sk);
924 		if (new_sk->sk_state == SMC_CLOSED) {
925 			if (isk->clcsock) {
926 				sock_release(isk->clcsock);
927 				isk->clcsock = NULL;
928 			}
929 			new_sk->sk_prot->unhash(new_sk);
930 			sock_put(new_sk); /* final */
931 			continue;
932 		}
933 		if (new_sock)
934 			sock_graft(new_sk, new_sock);
935 		return new_sk;
936 	}
937 	return NULL;
938 }
939 
940 /* clean up for a created but never accepted sock */
941 void smc_close_non_accepted(struct sock *sk)
942 {
943 	struct smc_sock *smc = smc_sk(sk);
944 
945 	lock_sock(sk);
946 	if (!sk->sk_lingertime)
947 		/* wait for peer closing */
948 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
949 	if (!smc->use_fallback) {
950 		smc_close_active(smc);
951 		sock_set_flag(sk, SOCK_DEAD);
952 		sk->sk_shutdown |= SHUTDOWN_MASK;
953 	}
954 	if (smc->clcsock) {
955 		struct socket *tcp;
956 
957 		tcp = smc->clcsock;
958 		smc->clcsock = NULL;
959 		sock_release(tcp);
960 	}
961 	if (smc->use_fallback) {
962 		sock_put(sk); /* passive closing */
963 		sk->sk_state = SMC_CLOSED;
964 	} else {
965 		if (sk->sk_state == SMC_CLOSED)
966 			smc_conn_free(&smc->conn);
967 	}
968 	release_sock(sk);
969 	sk->sk_prot->unhash(sk);
970 	sock_put(sk); /* final sock_put */
971 }
972 
973 static int smc_serv_conf_first_link(struct smc_sock *smc)
974 {
975 	struct net *net = sock_net(smc->clcsock->sk);
976 	struct smc_link_group *lgr = smc->conn.lgr;
977 	struct smc_link *link;
978 	int rest;
979 	int rc;
980 
981 	link = &lgr->lnk[SMC_SINGLE_LINK];
982 
983 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
984 		return SMC_CLC_DECL_ERR_REGRMB;
985 
986 	/* send CONFIRM LINK request to client over the RoCE fabric */
987 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
988 	if (rc < 0)
989 		return SMC_CLC_DECL_TIMEOUT_CL;
990 
991 	/* receive CONFIRM LINK response from client over the RoCE fabric */
992 	rest = wait_for_completion_interruptible_timeout(
993 		&link->llc_confirm_resp,
994 		SMC_LLC_WAIT_FIRST_TIME);
995 	if (rest <= 0) {
996 		struct smc_clc_msg_decline dclc;
997 
998 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
999 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1000 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
1001 	}
1002 
1003 	if (link->llc_confirm_resp_rc)
1004 		return SMC_CLC_DECL_RMBE_EC;
1005 
1006 	/* send ADD LINK request to client over the RoCE fabric */
1007 	rc = smc_llc_send_add_link(link,
1008 				   link->smcibdev->mac[link->ibport - 1],
1009 				   link->gid, SMC_LLC_REQ);
1010 	if (rc < 0)
1011 		return SMC_CLC_DECL_TIMEOUT_AL;
1012 
1013 	/* receive ADD LINK response from client over the RoCE fabric */
1014 	rest = wait_for_completion_interruptible_timeout(&link->llc_add_resp,
1015 							 SMC_LLC_WAIT_TIME);
1016 	if (rest <= 0) {
1017 		struct smc_clc_msg_decline dclc;
1018 
1019 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1020 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1021 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_AL : rc;
1022 	}
1023 
1024 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
1025 
1026 	return 0;
1027 }
1028 
1029 /* listen worker: finish */
1030 static void smc_listen_out(struct smc_sock *new_smc)
1031 {
1032 	struct smc_sock *lsmc = new_smc->listen_smc;
1033 	struct sock *newsmcsk = &new_smc->sk;
1034 
1035 	lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1036 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1037 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1038 	} else { /* no longer listening */
1039 		smc_close_non_accepted(newsmcsk);
1040 	}
1041 	release_sock(&lsmc->sk);
1042 
1043 	/* Wake up accept */
1044 	lsmc->sk.sk_data_ready(&lsmc->sk);
1045 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1046 }
1047 
1048 /* listen worker: finish in state connected */
1049 static void smc_listen_out_connected(struct smc_sock *new_smc)
1050 {
1051 	struct sock *newsmcsk = &new_smc->sk;
1052 
1053 	sk_refcnt_debug_inc(newsmcsk);
1054 	if (newsmcsk->sk_state == SMC_INIT)
1055 		newsmcsk->sk_state = SMC_ACTIVE;
1056 
1057 	smc_listen_out(new_smc);
1058 }
1059 
1060 /* listen worker: finish in error state */
1061 static void smc_listen_out_err(struct smc_sock *new_smc)
1062 {
1063 	struct sock *newsmcsk = &new_smc->sk;
1064 
1065 	if (newsmcsk->sk_state == SMC_INIT)
1066 		sock_put(&new_smc->sk); /* passive closing */
1067 	newsmcsk->sk_state = SMC_CLOSED;
1068 	smc_conn_free(&new_smc->conn);
1069 
1070 	smc_listen_out(new_smc);
1071 }
1072 
1073 /* listen worker: decline and fall back if possible */
1074 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1075 			       int local_contact)
1076 {
1077 	/* RDMA setup failed, switch back to TCP */
1078 	if (local_contact == SMC_FIRST_CONTACT)
1079 		smc_lgr_forget(new_smc->conn.lgr);
1080 	if (reason_code < 0) { /* error, no fallback possible */
1081 		smc_listen_out_err(new_smc);
1082 		return;
1083 	}
1084 	smc_conn_free(&new_smc->conn);
1085 	new_smc->use_fallback = true;
1086 	new_smc->fallback_rsn = reason_code;
1087 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1088 		if (smc_clc_send_decline(new_smc, reason_code) < 0) {
1089 			smc_listen_out_err(new_smc);
1090 			return;
1091 		}
1092 	}
1093 	smc_listen_out_connected(new_smc);
1094 }
1095 
1096 /* listen worker: check prefixes */
1097 static int smc_listen_prfx_check(struct smc_sock *new_smc,
1098 				 struct smc_clc_msg_proposal *pclc)
1099 {
1100 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1101 	struct socket *newclcsock = new_smc->clcsock;
1102 
1103 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1104 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1105 		return SMC_CLC_DECL_DIFFPREFIX;
1106 
1107 	return 0;
1108 }
1109 
1110 /* listen worker: initialize connection and buffers */
1111 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1112 				struct smc_init_info *ini)
1113 {
1114 	int rc;
1115 
1116 	/* allocate connection / link group */
1117 	rc = smc_conn_create(new_smc, ini);
1118 	if (rc)
1119 		return rc;
1120 
1121 	/* create send buffer and rmb */
1122 	if (smc_buf_create(new_smc, false))
1123 		return SMC_CLC_DECL_MEM;
1124 
1125 	return 0;
1126 }
1127 
1128 /* listen worker: initialize connection and buffers for SMC-D */
1129 static int smc_listen_ism_init(struct smc_sock *new_smc,
1130 			       struct smc_clc_msg_proposal *pclc,
1131 			       struct smc_init_info *ini)
1132 {
1133 	struct smc_clc_msg_smcd *pclc_smcd;
1134 	int rc;
1135 
1136 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
1137 	ini->ism_gid = pclc_smcd->gid;
1138 	rc = smc_conn_create(new_smc, ini);
1139 	if (rc)
1140 		return rc;
1141 
1142 	/* Check if peer can be reached via ISM device */
1143 	if (smc_ism_cantalk(new_smc->conn.lgr->peer_gid,
1144 			    new_smc->conn.lgr->vlan_id,
1145 			    new_smc->conn.lgr->smcd)) {
1146 		if (ini->cln_first_contact == SMC_FIRST_CONTACT)
1147 			smc_lgr_forget(new_smc->conn.lgr);
1148 		smc_conn_free(&new_smc->conn);
1149 		return SMC_CLC_DECL_SMCDNOTALK;
1150 	}
1151 
1152 	/* Create send and receive buffers */
1153 	if (smc_buf_create(new_smc, true)) {
1154 		if (ini->cln_first_contact == SMC_FIRST_CONTACT)
1155 			smc_lgr_forget(new_smc->conn.lgr);
1156 		smc_conn_free(&new_smc->conn);
1157 		return SMC_CLC_DECL_MEM;
1158 	}
1159 
1160 	return 0;
1161 }
1162 
1163 /* listen worker: register buffers */
1164 static int smc_listen_rdma_reg(struct smc_sock *new_smc, int local_contact)
1165 {
1166 	struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
1167 
1168 	if (local_contact != SMC_FIRST_CONTACT) {
1169 		if (smc_reg_rmb(link, new_smc->conn.rmb_desc, true))
1170 			return SMC_CLC_DECL_ERR_REGRMB;
1171 	}
1172 	smc_rmb_sync_sg_for_device(&new_smc->conn);
1173 
1174 	return 0;
1175 }
1176 
1177 /* listen worker: finish RDMA setup */
1178 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
1179 				  struct smc_clc_msg_accept_confirm *cclc,
1180 				  int local_contact)
1181 {
1182 	struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
1183 	int reason_code = 0;
1184 
1185 	if (local_contact == SMC_FIRST_CONTACT)
1186 		smc_link_save_peer_info(link, cclc);
1187 
1188 	if (smc_rmb_rtoken_handling(&new_smc->conn, cclc)) {
1189 		reason_code = SMC_CLC_DECL_ERR_RTOK;
1190 		goto decline;
1191 	}
1192 
1193 	if (local_contact == SMC_FIRST_CONTACT) {
1194 		if (smc_ib_ready_link(link)) {
1195 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
1196 			goto decline;
1197 		}
1198 		/* QP confirmation over RoCE fabric */
1199 		reason_code = smc_serv_conf_first_link(new_smc);
1200 		if (reason_code)
1201 			goto decline;
1202 	}
1203 	return 0;
1204 
1205 decline:
1206 	smc_listen_decline(new_smc, reason_code, local_contact);
1207 	return reason_code;
1208 }
1209 
1210 /* setup for RDMA connection of server */
1211 static void smc_listen_work(struct work_struct *work)
1212 {
1213 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
1214 						smc_listen_work);
1215 	struct socket *newclcsock = new_smc->clcsock;
1216 	struct smc_clc_msg_accept_confirm cclc;
1217 	struct smc_clc_msg_proposal *pclc;
1218 	struct smc_init_info ini = {0};
1219 	bool ism_supported = false;
1220 	u8 buf[SMC_CLC_MAX_LEN];
1221 	int rc = 0;
1222 
1223 	if (new_smc->use_fallback) {
1224 		smc_listen_out_connected(new_smc);
1225 		return;
1226 	}
1227 
1228 	/* check if peer is smc capable */
1229 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
1230 		new_smc->use_fallback = true;
1231 		new_smc->fallback_rsn = SMC_CLC_DECL_PEERNOSMC;
1232 		smc_listen_out_connected(new_smc);
1233 		return;
1234 	}
1235 
1236 	/* do inband token exchange -
1237 	 * wait for and receive SMC Proposal CLC message
1238 	 */
1239 	pclc = (struct smc_clc_msg_proposal *)&buf;
1240 	rc = smc_clc_wait_msg(new_smc, pclc, SMC_CLC_MAX_LEN,
1241 			      SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
1242 	if (rc)
1243 		goto out_decl;
1244 
1245 	/* IPSec connections opt out of SMC-R optimizations */
1246 	if (using_ipsec(new_smc)) {
1247 		rc = SMC_CLC_DECL_IPSEC;
1248 		goto out_decl;
1249 	}
1250 
1251 	/* check for matching IP prefix and subnet length */
1252 	rc = smc_listen_prfx_check(new_smc, pclc);
1253 	if (rc)
1254 		goto out_decl;
1255 
1256 	/* get vlan id from IP device */
1257 	if (smc_vlan_by_tcpsk(new_smc->clcsock, &ini)) {
1258 		rc = SMC_CLC_DECL_GETVLANERR;
1259 		goto out_decl;
1260 	}
1261 
1262 	mutex_lock(&smc_server_lgr_pending);
1263 	smc_close_init(new_smc);
1264 	smc_rx_init(new_smc);
1265 	smc_tx_init(new_smc);
1266 
1267 	/* check if ISM is available */
1268 	if (pclc->hdr.path == SMC_TYPE_D || pclc->hdr.path == SMC_TYPE_B) {
1269 		ini.is_smcd = true; /* prepare ISM check */
1270 		rc = smc_find_ism_device(new_smc, &ini);
1271 		if (!rc)
1272 			rc = smc_listen_ism_init(new_smc, pclc, &ini);
1273 		if (!rc)
1274 			ism_supported = true;
1275 		else if (pclc->hdr.path == SMC_TYPE_D)
1276 			goto out_unlock; /* skip RDMA and decline */
1277 	}
1278 
1279 	/* check if RDMA is available */
1280 	if (!ism_supported) { /* SMC_TYPE_R or SMC_TYPE_B */
1281 		/* prepare RDMA check */
1282 		memset(&ini, 0, sizeof(ini));
1283 		ini.is_smcd = false;
1284 		ini.ib_lcl = &pclc->lcl;
1285 		rc = smc_find_rdma_device(new_smc, &ini);
1286 		if (rc) {
1287 			/* no RDMA device found */
1288 			if (pclc->hdr.path == SMC_TYPE_B)
1289 				/* neither ISM nor RDMA device found */
1290 				rc = SMC_CLC_DECL_NOSMCDEV;
1291 			goto out_unlock;
1292 		}
1293 		rc = smc_listen_rdma_init(new_smc, &ini);
1294 		if (rc)
1295 			goto out_unlock;
1296 		rc = smc_listen_rdma_reg(new_smc, ini.cln_first_contact);
1297 		if (rc)
1298 			goto out_unlock;
1299 	}
1300 
1301 	/* send SMC Accept CLC message */
1302 	rc = smc_clc_send_accept(new_smc, ini.cln_first_contact);
1303 	if (rc)
1304 		goto out_unlock;
1305 
1306 	/* SMC-D does not need this lock any more */
1307 	if (ism_supported)
1308 		mutex_unlock(&smc_server_lgr_pending);
1309 
1310 	/* receive SMC Confirm CLC message */
1311 	rc = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
1312 			      SMC_CLC_CONFIRM, CLC_WAIT_TIME);
1313 	if (rc) {
1314 		if (!ism_supported)
1315 			goto out_unlock;
1316 		goto out_decl;
1317 	}
1318 
1319 	/* finish worker */
1320 	if (!ism_supported) {
1321 		rc = smc_listen_rdma_finish(new_smc, &cclc,
1322 					    ini.cln_first_contact);
1323 		mutex_unlock(&smc_server_lgr_pending);
1324 		if (rc)
1325 			return;
1326 	}
1327 	smc_conn_save_peer_info(new_smc, &cclc);
1328 	smc_listen_out_connected(new_smc);
1329 	return;
1330 
1331 out_unlock:
1332 	mutex_unlock(&smc_server_lgr_pending);
1333 out_decl:
1334 	smc_listen_decline(new_smc, rc, ini.cln_first_contact);
1335 }
1336 
1337 static void smc_tcp_listen_work(struct work_struct *work)
1338 {
1339 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
1340 					     tcp_listen_work);
1341 	struct sock *lsk = &lsmc->sk;
1342 	struct smc_sock *new_smc;
1343 	int rc = 0;
1344 
1345 	lock_sock(lsk);
1346 	while (lsk->sk_state == SMC_LISTEN) {
1347 		rc = smc_clcsock_accept(lsmc, &new_smc);
1348 		if (rc)
1349 			goto out;
1350 		if (!new_smc)
1351 			continue;
1352 
1353 		new_smc->listen_smc = lsmc;
1354 		new_smc->use_fallback = lsmc->use_fallback;
1355 		new_smc->fallback_rsn = lsmc->fallback_rsn;
1356 		sock_hold(lsk); /* sock_put in smc_listen_work */
1357 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
1358 		smc_copy_sock_settings_to_smc(new_smc);
1359 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
1360 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
1361 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
1362 		if (!schedule_work(&new_smc->smc_listen_work))
1363 			sock_put(&new_smc->sk);
1364 	}
1365 
1366 out:
1367 	release_sock(lsk);
1368 	sock_put(&lsmc->sk); /* sock_hold in smc_listen */
1369 }
1370 
1371 static int smc_listen(struct socket *sock, int backlog)
1372 {
1373 	struct sock *sk = sock->sk;
1374 	struct smc_sock *smc;
1375 	int rc;
1376 
1377 	smc = smc_sk(sk);
1378 	lock_sock(sk);
1379 
1380 	rc = -EINVAL;
1381 	if ((sk->sk_state != SMC_INIT) && (sk->sk_state != SMC_LISTEN))
1382 		goto out;
1383 
1384 	rc = 0;
1385 	if (sk->sk_state == SMC_LISTEN) {
1386 		sk->sk_max_ack_backlog = backlog;
1387 		goto out;
1388 	}
1389 	/* some socket options are handled in core, so we could not apply
1390 	 * them to the clc socket -- copy smc socket options to clc socket
1391 	 */
1392 	smc_copy_sock_settings_to_clc(smc);
1393 	if (!smc->use_fallback)
1394 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1395 
1396 	rc = kernel_listen(smc->clcsock, backlog);
1397 	if (rc)
1398 		goto out;
1399 	sk->sk_max_ack_backlog = backlog;
1400 	sk->sk_ack_backlog = 0;
1401 	sk->sk_state = SMC_LISTEN;
1402 	sock_hold(sk); /* sock_hold in tcp_listen_worker */
1403 	if (!schedule_work(&smc->tcp_listen_work))
1404 		sock_put(sk);
1405 
1406 out:
1407 	release_sock(sk);
1408 	return rc;
1409 }
1410 
1411 static int smc_accept(struct socket *sock, struct socket *new_sock,
1412 		      int flags, bool kern)
1413 {
1414 	struct sock *sk = sock->sk, *nsk;
1415 	DECLARE_WAITQUEUE(wait, current);
1416 	struct smc_sock *lsmc;
1417 	long timeo;
1418 	int rc = 0;
1419 
1420 	lsmc = smc_sk(sk);
1421 	sock_hold(sk); /* sock_put below */
1422 	lock_sock(sk);
1423 
1424 	if (lsmc->sk.sk_state != SMC_LISTEN) {
1425 		rc = -EINVAL;
1426 		release_sock(sk);
1427 		goto out;
1428 	}
1429 
1430 	/* Wait for an incoming connection */
1431 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1432 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
1433 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1434 		set_current_state(TASK_INTERRUPTIBLE);
1435 		if (!timeo) {
1436 			rc = -EAGAIN;
1437 			break;
1438 		}
1439 		release_sock(sk);
1440 		timeo = schedule_timeout(timeo);
1441 		/* wakeup by sk_data_ready in smc_listen_work() */
1442 		sched_annotate_sleep();
1443 		lock_sock(sk);
1444 		if (signal_pending(current)) {
1445 			rc = sock_intr_errno(timeo);
1446 			break;
1447 		}
1448 	}
1449 	set_current_state(TASK_RUNNING);
1450 	remove_wait_queue(sk_sleep(sk), &wait);
1451 
1452 	if (!rc)
1453 		rc = sock_error(nsk);
1454 	release_sock(sk);
1455 	if (rc)
1456 		goto out;
1457 
1458 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
1459 		/* wait till data arrives on the socket */
1460 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
1461 								MSEC_PER_SEC);
1462 		if (smc_sk(nsk)->use_fallback) {
1463 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
1464 
1465 			lock_sock(clcsk);
1466 			if (skb_queue_empty(&clcsk->sk_receive_queue))
1467 				sk_wait_data(clcsk, &timeo, NULL);
1468 			release_sock(clcsk);
1469 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
1470 			lock_sock(nsk);
1471 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
1472 			release_sock(nsk);
1473 		}
1474 	}
1475 
1476 out:
1477 	sock_put(sk); /* sock_hold above */
1478 	return rc;
1479 }
1480 
1481 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1482 		       int peer)
1483 {
1484 	struct smc_sock *smc;
1485 
1486 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
1487 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
1488 		return -ENOTCONN;
1489 
1490 	smc = smc_sk(sock->sk);
1491 
1492 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
1493 }
1494 
1495 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1496 {
1497 	struct sock *sk = sock->sk;
1498 	struct smc_sock *smc;
1499 	int rc = -EPIPE;
1500 
1501 	smc = smc_sk(sk);
1502 	lock_sock(sk);
1503 	if ((sk->sk_state != SMC_ACTIVE) &&
1504 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1505 	    (sk->sk_state != SMC_INIT))
1506 		goto out;
1507 
1508 	if (msg->msg_flags & MSG_FASTOPEN) {
1509 		if (sk->sk_state == SMC_INIT) {
1510 			smc->use_fallback = true;
1511 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1512 		} else {
1513 			rc = -EINVAL;
1514 			goto out;
1515 		}
1516 	}
1517 
1518 	if (smc->use_fallback)
1519 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
1520 	else
1521 		rc = smc_tx_sendmsg(smc, msg, len);
1522 out:
1523 	release_sock(sk);
1524 	return rc;
1525 }
1526 
1527 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1528 		       int flags)
1529 {
1530 	struct sock *sk = sock->sk;
1531 	struct smc_sock *smc;
1532 	int rc = -ENOTCONN;
1533 
1534 	smc = smc_sk(sk);
1535 	lock_sock(sk);
1536 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
1537 		/* socket was connected before, no more data to read */
1538 		rc = 0;
1539 		goto out;
1540 	}
1541 	if ((sk->sk_state == SMC_INIT) ||
1542 	    (sk->sk_state == SMC_LISTEN) ||
1543 	    (sk->sk_state == SMC_CLOSED))
1544 		goto out;
1545 
1546 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1547 		rc = 0;
1548 		goto out;
1549 	}
1550 
1551 	if (smc->use_fallback) {
1552 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
1553 	} else {
1554 		msg->msg_namelen = 0;
1555 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
1556 	}
1557 
1558 out:
1559 	release_sock(sk);
1560 	return rc;
1561 }
1562 
1563 static __poll_t smc_accept_poll(struct sock *parent)
1564 {
1565 	struct smc_sock *isk = smc_sk(parent);
1566 	__poll_t mask = 0;
1567 
1568 	spin_lock(&isk->accept_q_lock);
1569 	if (!list_empty(&isk->accept_q))
1570 		mask = EPOLLIN | EPOLLRDNORM;
1571 	spin_unlock(&isk->accept_q_lock);
1572 
1573 	return mask;
1574 }
1575 
1576 static __poll_t smc_poll(struct file *file, struct socket *sock,
1577 			     poll_table *wait)
1578 {
1579 	struct sock *sk = sock->sk;
1580 	struct smc_sock *smc;
1581 	__poll_t mask = 0;
1582 
1583 	if (!sk)
1584 		return EPOLLNVAL;
1585 
1586 	smc = smc_sk(sock->sk);
1587 	if (smc->use_fallback) {
1588 		/* delegate to CLC child sock */
1589 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
1590 		sk->sk_err = smc->clcsock->sk->sk_err;
1591 	} else {
1592 		if (sk->sk_state != SMC_CLOSED)
1593 			sock_poll_wait(file, sock, wait);
1594 		if (sk->sk_err)
1595 			mask |= EPOLLERR;
1596 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1597 		    (sk->sk_state == SMC_CLOSED))
1598 			mask |= EPOLLHUP;
1599 		if (sk->sk_state == SMC_LISTEN) {
1600 			/* woken up by sk_data_ready in smc_listen_work() */
1601 			mask |= smc_accept_poll(sk);
1602 		} else if (smc->use_fallback) { /* as result of connect_work()*/
1603 			mask |= smc->clcsock->ops->poll(file, smc->clcsock,
1604 							   wait);
1605 			sk->sk_err = smc->clcsock->sk->sk_err;
1606 		} else {
1607 			if ((sk->sk_state != SMC_INIT &&
1608 			     atomic_read(&smc->conn.sndbuf_space)) ||
1609 			    sk->sk_shutdown & SEND_SHUTDOWN) {
1610 				mask |= EPOLLOUT | EPOLLWRNORM;
1611 			} else {
1612 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1613 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1614 			}
1615 			if (atomic_read(&smc->conn.bytes_to_rcv))
1616 				mask |= EPOLLIN | EPOLLRDNORM;
1617 			if (sk->sk_shutdown & RCV_SHUTDOWN)
1618 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
1619 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
1620 				mask |= EPOLLIN;
1621 			if (smc->conn.urg_state == SMC_URG_VALID)
1622 				mask |= EPOLLPRI;
1623 		}
1624 	}
1625 
1626 	return mask;
1627 }
1628 
1629 static int smc_shutdown(struct socket *sock, int how)
1630 {
1631 	struct sock *sk = sock->sk;
1632 	struct smc_sock *smc;
1633 	int rc = -EINVAL;
1634 	int rc1 = 0;
1635 
1636 	smc = smc_sk(sk);
1637 
1638 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
1639 		return rc;
1640 
1641 	lock_sock(sk);
1642 
1643 	rc = -ENOTCONN;
1644 	if ((sk->sk_state != SMC_ACTIVE) &&
1645 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
1646 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
1647 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1648 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
1649 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
1650 		goto out;
1651 	if (smc->use_fallback) {
1652 		rc = kernel_sock_shutdown(smc->clcsock, how);
1653 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
1654 		if (sk->sk_shutdown == SHUTDOWN_MASK)
1655 			sk->sk_state = SMC_CLOSED;
1656 		goto out;
1657 	}
1658 	switch (how) {
1659 	case SHUT_RDWR:		/* shutdown in both directions */
1660 		rc = smc_close_active(smc);
1661 		break;
1662 	case SHUT_WR:
1663 		rc = smc_close_shutdown_write(smc);
1664 		break;
1665 	case SHUT_RD:
1666 		rc = 0;
1667 		/* nothing more to do because peer is not involved */
1668 		break;
1669 	}
1670 	if (smc->clcsock)
1671 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
1672 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
1673 	sk->sk_shutdown |= how + 1;
1674 
1675 out:
1676 	release_sock(sk);
1677 	return rc ? rc : rc1;
1678 }
1679 
1680 static int smc_setsockopt(struct socket *sock, int level, int optname,
1681 			  char __user *optval, unsigned int optlen)
1682 {
1683 	struct sock *sk = sock->sk;
1684 	struct smc_sock *smc;
1685 	int val, rc;
1686 
1687 	smc = smc_sk(sk);
1688 
1689 	/* generic setsockopts reaching us here always apply to the
1690 	 * CLC socket
1691 	 */
1692 	rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
1693 					   optval, optlen);
1694 	if (smc->clcsock->sk->sk_err) {
1695 		sk->sk_err = smc->clcsock->sk->sk_err;
1696 		sk->sk_error_report(sk);
1697 	}
1698 	if (rc)
1699 		return rc;
1700 
1701 	if (optlen < sizeof(int))
1702 		return -EINVAL;
1703 	if (get_user(val, (int __user *)optval))
1704 		return -EFAULT;
1705 
1706 	lock_sock(sk);
1707 	switch (optname) {
1708 	case TCP_ULP:
1709 	case TCP_FASTOPEN:
1710 	case TCP_FASTOPEN_CONNECT:
1711 	case TCP_FASTOPEN_KEY:
1712 	case TCP_FASTOPEN_NO_COOKIE:
1713 		/* option not supported by SMC */
1714 		if (sk->sk_state == SMC_INIT) {
1715 			smc->use_fallback = true;
1716 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1717 		} else {
1718 			if (!smc->use_fallback)
1719 				rc = -EINVAL;
1720 		}
1721 		break;
1722 	case TCP_NODELAY:
1723 		if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1724 			if (val && !smc->use_fallback)
1725 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1726 						 0);
1727 		}
1728 		break;
1729 	case TCP_CORK:
1730 		if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1731 			if (!val && !smc->use_fallback)
1732 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1733 						 0);
1734 		}
1735 		break;
1736 	case TCP_DEFER_ACCEPT:
1737 		smc->sockopt_defer_accept = val;
1738 		break;
1739 	default:
1740 		break;
1741 	}
1742 	release_sock(sk);
1743 
1744 	return rc;
1745 }
1746 
1747 static int smc_getsockopt(struct socket *sock, int level, int optname,
1748 			  char __user *optval, int __user *optlen)
1749 {
1750 	struct smc_sock *smc;
1751 
1752 	smc = smc_sk(sock->sk);
1753 	/* socket options apply to the CLC socket */
1754 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
1755 					     optval, optlen);
1756 }
1757 
1758 static int smc_ioctl(struct socket *sock, unsigned int cmd,
1759 		     unsigned long arg)
1760 {
1761 	union smc_host_cursor cons, urg;
1762 	struct smc_connection *conn;
1763 	struct smc_sock *smc;
1764 	int answ;
1765 
1766 	smc = smc_sk(sock->sk);
1767 	conn = &smc->conn;
1768 	lock_sock(&smc->sk);
1769 	if (smc->use_fallback) {
1770 		if (!smc->clcsock) {
1771 			release_sock(&smc->sk);
1772 			return -EBADF;
1773 		}
1774 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
1775 		release_sock(&smc->sk);
1776 		return answ;
1777 	}
1778 	switch (cmd) {
1779 	case SIOCINQ: /* same as FIONREAD */
1780 		if (smc->sk.sk_state == SMC_LISTEN) {
1781 			release_sock(&smc->sk);
1782 			return -EINVAL;
1783 		}
1784 		if (smc->sk.sk_state == SMC_INIT ||
1785 		    smc->sk.sk_state == SMC_CLOSED)
1786 			answ = 0;
1787 		else
1788 			answ = atomic_read(&smc->conn.bytes_to_rcv);
1789 		break;
1790 	case SIOCOUTQ:
1791 		/* output queue size (not send + not acked) */
1792 		if (smc->sk.sk_state == SMC_LISTEN) {
1793 			release_sock(&smc->sk);
1794 			return -EINVAL;
1795 		}
1796 		if (smc->sk.sk_state == SMC_INIT ||
1797 		    smc->sk.sk_state == SMC_CLOSED)
1798 			answ = 0;
1799 		else
1800 			answ = smc->conn.sndbuf_desc->len -
1801 					atomic_read(&smc->conn.sndbuf_space);
1802 		break;
1803 	case SIOCOUTQNSD:
1804 		/* output queue size (not send only) */
1805 		if (smc->sk.sk_state == SMC_LISTEN) {
1806 			release_sock(&smc->sk);
1807 			return -EINVAL;
1808 		}
1809 		if (smc->sk.sk_state == SMC_INIT ||
1810 		    smc->sk.sk_state == SMC_CLOSED)
1811 			answ = 0;
1812 		else
1813 			answ = smc_tx_prepared_sends(&smc->conn);
1814 		break;
1815 	case SIOCATMARK:
1816 		if (smc->sk.sk_state == SMC_LISTEN) {
1817 			release_sock(&smc->sk);
1818 			return -EINVAL;
1819 		}
1820 		if (smc->sk.sk_state == SMC_INIT ||
1821 		    smc->sk.sk_state == SMC_CLOSED) {
1822 			answ = 0;
1823 		} else {
1824 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
1825 			smc_curs_copy(&urg, &conn->urg_curs, conn);
1826 			answ = smc_curs_diff(conn->rmb_desc->len,
1827 					     &cons, &urg) == 1;
1828 		}
1829 		break;
1830 	default:
1831 		release_sock(&smc->sk);
1832 		return -ENOIOCTLCMD;
1833 	}
1834 	release_sock(&smc->sk);
1835 
1836 	return put_user(answ, (int __user *)arg);
1837 }
1838 
1839 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
1840 			    int offset, size_t size, int flags)
1841 {
1842 	struct sock *sk = sock->sk;
1843 	struct smc_sock *smc;
1844 	int rc = -EPIPE;
1845 
1846 	smc = smc_sk(sk);
1847 	lock_sock(sk);
1848 	if (sk->sk_state != SMC_ACTIVE) {
1849 		release_sock(sk);
1850 		goto out;
1851 	}
1852 	release_sock(sk);
1853 	if (smc->use_fallback)
1854 		rc = kernel_sendpage(smc->clcsock, page, offset,
1855 				     size, flags);
1856 	else
1857 		rc = sock_no_sendpage(sock, page, offset, size, flags);
1858 
1859 out:
1860 	return rc;
1861 }
1862 
1863 /* Map the affected portions of the rmbe into an spd, note the number of bytes
1864  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
1865  * updates till whenever a respective page has been fully processed.
1866  * Note that subsequent recv() calls have to wait till all splice() processing
1867  * completed.
1868  */
1869 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
1870 			       struct pipe_inode_info *pipe, size_t len,
1871 			       unsigned int flags)
1872 {
1873 	struct sock *sk = sock->sk;
1874 	struct smc_sock *smc;
1875 	int rc = -ENOTCONN;
1876 
1877 	smc = smc_sk(sk);
1878 	lock_sock(sk);
1879 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
1880 		/* socket was connected before, no more data to read */
1881 		rc = 0;
1882 		goto out;
1883 	}
1884 	if (sk->sk_state == SMC_INIT ||
1885 	    sk->sk_state == SMC_LISTEN ||
1886 	    sk->sk_state == SMC_CLOSED)
1887 		goto out;
1888 
1889 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1890 		rc = 0;
1891 		goto out;
1892 	}
1893 
1894 	if (smc->use_fallback) {
1895 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
1896 						    pipe, len, flags);
1897 	} else {
1898 		if (*ppos) {
1899 			rc = -ESPIPE;
1900 			goto out;
1901 		}
1902 		if (flags & SPLICE_F_NONBLOCK)
1903 			flags = MSG_DONTWAIT;
1904 		else
1905 			flags = 0;
1906 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
1907 	}
1908 out:
1909 	release_sock(sk);
1910 
1911 	return rc;
1912 }
1913 
1914 /* must look like tcp */
1915 static const struct proto_ops smc_sock_ops = {
1916 	.family		= PF_SMC,
1917 	.owner		= THIS_MODULE,
1918 	.release	= smc_release,
1919 	.bind		= smc_bind,
1920 	.connect	= smc_connect,
1921 	.socketpair	= sock_no_socketpair,
1922 	.accept		= smc_accept,
1923 	.getname	= smc_getname,
1924 	.poll		= smc_poll,
1925 	.ioctl		= smc_ioctl,
1926 	.listen		= smc_listen,
1927 	.shutdown	= smc_shutdown,
1928 	.setsockopt	= smc_setsockopt,
1929 	.getsockopt	= smc_getsockopt,
1930 	.sendmsg	= smc_sendmsg,
1931 	.recvmsg	= smc_recvmsg,
1932 	.mmap		= sock_no_mmap,
1933 	.sendpage	= smc_sendpage,
1934 	.splice_read	= smc_splice_read,
1935 };
1936 
1937 static int smc_create(struct net *net, struct socket *sock, int protocol,
1938 		      int kern)
1939 {
1940 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
1941 	struct smc_sock *smc;
1942 	struct sock *sk;
1943 	int rc;
1944 
1945 	rc = -ESOCKTNOSUPPORT;
1946 	if (sock->type != SOCK_STREAM)
1947 		goto out;
1948 
1949 	rc = -EPROTONOSUPPORT;
1950 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
1951 		goto out;
1952 
1953 	rc = -ENOBUFS;
1954 	sock->ops = &smc_sock_ops;
1955 	sk = smc_sock_alloc(net, sock, protocol);
1956 	if (!sk)
1957 		goto out;
1958 
1959 	/* create internal TCP socket for CLC handshake and fallback */
1960 	smc = smc_sk(sk);
1961 	smc->use_fallback = false; /* assume rdma capability first */
1962 	smc->fallback_rsn = 0;
1963 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
1964 			      &smc->clcsock);
1965 	if (rc) {
1966 		sk_common_release(sk);
1967 		goto out;
1968 	}
1969 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
1970 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
1971 
1972 out:
1973 	return rc;
1974 }
1975 
1976 static const struct net_proto_family smc_sock_family_ops = {
1977 	.family	= PF_SMC,
1978 	.owner	= THIS_MODULE,
1979 	.create	= smc_create,
1980 };
1981 
1982 unsigned int smc_net_id;
1983 
1984 static __net_init int smc_net_init(struct net *net)
1985 {
1986 	return smc_pnet_net_init(net);
1987 }
1988 
1989 static void __net_exit smc_net_exit(struct net *net)
1990 {
1991 	smc_pnet_net_exit(net);
1992 }
1993 
1994 static struct pernet_operations smc_net_ops = {
1995 	.init = smc_net_init,
1996 	.exit = smc_net_exit,
1997 	.id   = &smc_net_id,
1998 	.size = sizeof(struct smc_net),
1999 };
2000 
2001 static int __init smc_init(void)
2002 {
2003 	int rc;
2004 
2005 	rc = register_pernet_subsys(&smc_net_ops);
2006 	if (rc)
2007 		return rc;
2008 
2009 	rc = smc_pnet_init();
2010 	if (rc)
2011 		return rc;
2012 
2013 	rc = smc_llc_init();
2014 	if (rc) {
2015 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
2016 		goto out_pnet;
2017 	}
2018 
2019 	rc = smc_cdc_init();
2020 	if (rc) {
2021 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
2022 		goto out_pnet;
2023 	}
2024 
2025 	rc = proto_register(&smc_proto, 1);
2026 	if (rc) {
2027 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
2028 		goto out_pnet;
2029 	}
2030 
2031 	rc = proto_register(&smc_proto6, 1);
2032 	if (rc) {
2033 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
2034 		goto out_proto;
2035 	}
2036 
2037 	rc = sock_register(&smc_sock_family_ops);
2038 	if (rc) {
2039 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
2040 		goto out_proto6;
2041 	}
2042 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
2043 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
2044 
2045 	rc = smc_ib_register_client();
2046 	if (rc) {
2047 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
2048 		goto out_sock;
2049 	}
2050 
2051 	static_branch_enable(&tcp_have_smc);
2052 	return 0;
2053 
2054 out_sock:
2055 	sock_unregister(PF_SMC);
2056 out_proto6:
2057 	proto_unregister(&smc_proto6);
2058 out_proto:
2059 	proto_unregister(&smc_proto);
2060 out_pnet:
2061 	smc_pnet_exit();
2062 	return rc;
2063 }
2064 
2065 static void __exit smc_exit(void)
2066 {
2067 	smc_core_exit();
2068 	static_branch_disable(&tcp_have_smc);
2069 	smc_ib_unregister_client();
2070 	sock_unregister(PF_SMC);
2071 	proto_unregister(&smc_proto6);
2072 	proto_unregister(&smc_proto);
2073 	smc_pnet_exit();
2074 	unregister_pernet_subsys(&smc_net_ops);
2075 }
2076 
2077 module_init(smc_init);
2078 module_exit(smc_exit);
2079 
2080 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
2081 MODULE_DESCRIPTION("smc socket address family");
2082 MODULE_LICENSE("GPL");
2083 MODULE_ALIAS_NETPROTO(PF_SMC);
2084