xref: /linux/net/smc/af_smc.c (revision a5d9265e017f081f0dc133c0e2f45103d027b874)
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 "smc.h"
34 #include "smc_clc.h"
35 #include "smc_llc.h"
36 #include "smc_cdc.h"
37 #include "smc_core.h"
38 #include "smc_ib.h"
39 #include "smc_ism.h"
40 #include "smc_pnet.h"
41 #include "smc_tx.h"
42 #include "smc_rx.h"
43 #include "smc_close.h"
44 
45 static DEFINE_MUTEX(smc_server_lgr_pending);	/* serialize link group
46 						 * creation on server
47 						 */
48 static DEFINE_MUTEX(smc_client_lgr_pending);	/* serialize link group
49 						 * creation on client
50 						 */
51 
52 static void smc_tcp_listen_work(struct work_struct *);
53 static void smc_connect_work(struct work_struct *);
54 
55 static void smc_set_keepalive(struct sock *sk, int val)
56 {
57 	struct smc_sock *smc = smc_sk(sk);
58 
59 	smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
60 }
61 
62 static struct smc_hashinfo smc_v4_hashinfo = {
63 	.lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
64 };
65 
66 static struct smc_hashinfo smc_v6_hashinfo = {
67 	.lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
68 };
69 
70 int smc_hash_sk(struct sock *sk)
71 {
72 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
73 	struct hlist_head *head;
74 
75 	head = &h->ht;
76 
77 	write_lock_bh(&h->lock);
78 	sk_add_node(sk, head);
79 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
80 	write_unlock_bh(&h->lock);
81 
82 	return 0;
83 }
84 EXPORT_SYMBOL_GPL(smc_hash_sk);
85 
86 void smc_unhash_sk(struct sock *sk)
87 {
88 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
89 
90 	write_lock_bh(&h->lock);
91 	if (sk_del_node_init(sk))
92 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
93 	write_unlock_bh(&h->lock);
94 }
95 EXPORT_SYMBOL_GPL(smc_unhash_sk);
96 
97 struct proto smc_proto = {
98 	.name		= "SMC",
99 	.owner		= THIS_MODULE,
100 	.keepalive	= smc_set_keepalive,
101 	.hash		= smc_hash_sk,
102 	.unhash		= smc_unhash_sk,
103 	.obj_size	= sizeof(struct smc_sock),
104 	.h.smc_hash	= &smc_v4_hashinfo,
105 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
106 };
107 EXPORT_SYMBOL_GPL(smc_proto);
108 
109 struct proto smc_proto6 = {
110 	.name		= "SMC6",
111 	.owner		= THIS_MODULE,
112 	.keepalive	= smc_set_keepalive,
113 	.hash		= smc_hash_sk,
114 	.unhash		= smc_unhash_sk,
115 	.obj_size	= sizeof(struct smc_sock),
116 	.h.smc_hash	= &smc_v6_hashinfo,
117 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
118 };
119 EXPORT_SYMBOL_GPL(smc_proto6);
120 
121 static int smc_release(struct socket *sock)
122 {
123 	struct sock *sk = sock->sk;
124 	struct smc_sock *smc;
125 	int rc = 0;
126 
127 	if (!sk)
128 		goto out;
129 
130 	smc = smc_sk(sk);
131 
132 	/* cleanup for a dangling non-blocking connect */
133 	if (smc->connect_info && sk->sk_state == SMC_INIT)
134 		tcp_abort(smc->clcsock->sk, ECONNABORTED);
135 	flush_work(&smc->connect_work);
136 	kfree(smc->connect_info);
137 	smc->connect_info = NULL;
138 
139 	if (sk->sk_state == SMC_LISTEN)
140 		/* smc_close_non_accepted() is called and acquires
141 		 * sock lock for child sockets again
142 		 */
143 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
144 	else
145 		lock_sock(sk);
146 
147 	if (!smc->use_fallback) {
148 		rc = smc_close_active(smc);
149 		sock_set_flag(sk, SOCK_DEAD);
150 		sk->sk_shutdown |= SHUTDOWN_MASK;
151 	} else {
152 		if (sk->sk_state != SMC_LISTEN && sk->sk_state != SMC_INIT)
153 			sock_put(sk); /* passive closing */
154 		if (sk->sk_state == SMC_LISTEN) {
155 			/* wake up clcsock accept */
156 			rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
157 		}
158 		sk->sk_state = SMC_CLOSED;
159 		sk->sk_state_change(sk);
160 	}
161 
162 	sk->sk_prot->unhash(sk);
163 
164 	if (sk->sk_state == SMC_CLOSED) {
165 		if (smc->clcsock) {
166 			mutex_lock(&smc->clcsock_release_lock);
167 			sock_release(smc->clcsock);
168 			smc->clcsock = NULL;
169 			mutex_unlock(&smc->clcsock_release_lock);
170 		}
171 		if (!smc->use_fallback)
172 			smc_conn_free(&smc->conn);
173 	}
174 
175 	/* detach socket */
176 	sock_orphan(sk);
177 	sock->sk = NULL;
178 	release_sock(sk);
179 
180 	sock_put(sk); /* final sock_put */
181 out:
182 	return rc;
183 }
184 
185 static void smc_destruct(struct sock *sk)
186 {
187 	if (sk->sk_state != SMC_CLOSED)
188 		return;
189 	if (!sock_flag(sk, SOCK_DEAD))
190 		return;
191 
192 	sk_refcnt_debug_dec(sk);
193 }
194 
195 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
196 				   int protocol)
197 {
198 	struct smc_sock *smc;
199 	struct proto *prot;
200 	struct sock *sk;
201 
202 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
203 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
204 	if (!sk)
205 		return NULL;
206 
207 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
208 	sk->sk_state = SMC_INIT;
209 	sk->sk_destruct = smc_destruct;
210 	sk->sk_protocol = protocol;
211 	smc = smc_sk(sk);
212 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
213 	INIT_WORK(&smc->connect_work, smc_connect_work);
214 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
215 	INIT_LIST_HEAD(&smc->accept_q);
216 	spin_lock_init(&smc->accept_q_lock);
217 	spin_lock_init(&smc->conn.send_lock);
218 	sk->sk_prot->hash(sk);
219 	sk_refcnt_debug_inc(sk);
220 	mutex_init(&smc->clcsock_release_lock);
221 
222 	return sk;
223 }
224 
225 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
226 		    int addr_len)
227 {
228 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
229 	struct sock *sk = sock->sk;
230 	struct smc_sock *smc;
231 	int rc;
232 
233 	smc = smc_sk(sk);
234 
235 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
236 	rc = -EINVAL;
237 	if (addr_len < sizeof(struct sockaddr_in))
238 		goto out;
239 
240 	rc = -EAFNOSUPPORT;
241 	if (addr->sin_family != AF_INET &&
242 	    addr->sin_family != AF_INET6 &&
243 	    addr->sin_family != AF_UNSPEC)
244 		goto out;
245 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
246 	if (addr->sin_family == AF_UNSPEC &&
247 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
248 		goto out;
249 
250 	lock_sock(sk);
251 
252 	/* Check if socket is already active */
253 	rc = -EINVAL;
254 	if (sk->sk_state != SMC_INIT)
255 		goto out_rel;
256 
257 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
258 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
259 
260 out_rel:
261 	release_sock(sk);
262 out:
263 	return rc;
264 }
265 
266 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
267 				   unsigned long mask)
268 {
269 	/* options we don't get control via setsockopt for */
270 	nsk->sk_type = osk->sk_type;
271 	nsk->sk_sndbuf = osk->sk_sndbuf;
272 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
273 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
274 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
275 	nsk->sk_mark = osk->sk_mark;
276 	nsk->sk_priority = osk->sk_priority;
277 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
278 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
279 	nsk->sk_err = osk->sk_err;
280 
281 	nsk->sk_flags &= ~mask;
282 	nsk->sk_flags |= osk->sk_flags & mask;
283 }
284 
285 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
286 			     (1UL << SOCK_KEEPOPEN) | \
287 			     (1UL << SOCK_LINGER) | \
288 			     (1UL << SOCK_BROADCAST) | \
289 			     (1UL << SOCK_TIMESTAMP) | \
290 			     (1UL << SOCK_DBG) | \
291 			     (1UL << SOCK_RCVTSTAMP) | \
292 			     (1UL << SOCK_RCVTSTAMPNS) | \
293 			     (1UL << SOCK_LOCALROUTE) | \
294 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
295 			     (1UL << SOCK_RXQ_OVFL) | \
296 			     (1UL << SOCK_WIFI_STATUS) | \
297 			     (1UL << SOCK_NOFCS) | \
298 			     (1UL << SOCK_FILTER_LOCKED) | \
299 			     (1UL << SOCK_TSTAMP_NEW))
300 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
301  * clc socket (since smc is not called for these options from net/core)
302  */
303 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
304 {
305 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
306 }
307 
308 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
309 			     (1UL << SOCK_KEEPOPEN) | \
310 			     (1UL << SOCK_LINGER) | \
311 			     (1UL << SOCK_DBG))
312 /* copy only settings and flags relevant for smc from clc to smc socket */
313 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
314 {
315 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
316 }
317 
318 /* register a new rmb, send confirm_rkey msg to register with peer */
319 static int smc_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc,
320 		       bool conf_rkey)
321 {
322 	if (!rmb_desc->wr_reg) {
323 		/* register memory region for new rmb */
324 		if (smc_wr_reg_send(link, rmb_desc->mr_rx[SMC_SINGLE_LINK])) {
325 			rmb_desc->regerr = 1;
326 			return -EFAULT;
327 		}
328 		rmb_desc->wr_reg = 1;
329 	}
330 	if (!conf_rkey)
331 		return 0;
332 	/* exchange confirm_rkey msg with peer */
333 	if (smc_llc_do_confirm_rkey(link, rmb_desc)) {
334 		rmb_desc->regerr = 1;
335 		return -EFAULT;
336 	}
337 	return 0;
338 }
339 
340 static int smc_clnt_conf_first_link(struct smc_sock *smc)
341 {
342 	struct net *net = sock_net(smc->clcsock->sk);
343 	struct smc_link_group *lgr = smc->conn.lgr;
344 	struct smc_link *link;
345 	int rest;
346 	int rc;
347 
348 	link = &lgr->lnk[SMC_SINGLE_LINK];
349 	/* receive CONFIRM LINK request from server over RoCE fabric */
350 	rest = wait_for_completion_interruptible_timeout(
351 		&link->llc_confirm,
352 		SMC_LLC_WAIT_FIRST_TIME);
353 	if (rest <= 0) {
354 		struct smc_clc_msg_decline dclc;
355 
356 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
357 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
358 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
359 	}
360 
361 	if (link->llc_confirm_rc)
362 		return SMC_CLC_DECL_RMBE_EC;
363 
364 	rc = smc_ib_modify_qp_rts(link);
365 	if (rc)
366 		return SMC_CLC_DECL_ERR_RDYLNK;
367 
368 	smc_wr_remember_qp_attr(link);
369 
370 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
371 		return SMC_CLC_DECL_ERR_REGRMB;
372 
373 	/* send CONFIRM LINK response over RoCE fabric */
374 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
375 	if (rc < 0)
376 		return SMC_CLC_DECL_TIMEOUT_CL;
377 
378 	/* receive ADD LINK request from server over RoCE fabric */
379 	rest = wait_for_completion_interruptible_timeout(&link->llc_add,
380 							 SMC_LLC_WAIT_TIME);
381 	if (rest <= 0) {
382 		struct smc_clc_msg_decline dclc;
383 
384 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
385 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
386 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_AL : rc;
387 	}
388 
389 	/* send add link reject message, only one link supported for now */
390 	rc = smc_llc_send_add_link(link,
391 				   link->smcibdev->mac[link->ibport - 1],
392 				   link->gid, SMC_LLC_RESP);
393 	if (rc < 0)
394 		return SMC_CLC_DECL_TIMEOUT_AL;
395 
396 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
397 
398 	return 0;
399 }
400 
401 static void smcr_conn_save_peer_info(struct smc_sock *smc,
402 				     struct smc_clc_msg_accept_confirm *clc)
403 {
404 	int bufsize = smc_uncompress_bufsize(clc->rmbe_size);
405 
406 	smc->conn.peer_rmbe_idx = clc->rmbe_idx;
407 	smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
408 	smc->conn.peer_rmbe_size = bufsize;
409 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
410 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
411 }
412 
413 static void smcd_conn_save_peer_info(struct smc_sock *smc,
414 				     struct smc_clc_msg_accept_confirm *clc)
415 {
416 	int bufsize = smc_uncompress_bufsize(clc->dmbe_size);
417 
418 	smc->conn.peer_rmbe_idx = clc->dmbe_idx;
419 	smc->conn.peer_token = clc->token;
420 	/* msg header takes up space in the buffer */
421 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
422 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
423 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
424 }
425 
426 static void smc_conn_save_peer_info(struct smc_sock *smc,
427 				    struct smc_clc_msg_accept_confirm *clc)
428 {
429 	if (smc->conn.lgr->is_smcd)
430 		smcd_conn_save_peer_info(smc, clc);
431 	else
432 		smcr_conn_save_peer_info(smc, clc);
433 }
434 
435 static void smc_link_save_peer_info(struct smc_link *link,
436 				    struct smc_clc_msg_accept_confirm *clc)
437 {
438 	link->peer_qpn = ntoh24(clc->qpn);
439 	memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
440 	memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
441 	link->peer_psn = ntoh24(clc->psn);
442 	link->peer_mtu = clc->qp_mtu;
443 }
444 
445 /* fall back during connect */
446 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
447 {
448 	smc->use_fallback = true;
449 	smc->fallback_rsn = reason_code;
450 	smc_copy_sock_settings_to_clc(smc);
451 	if (smc->sk.sk_state == SMC_INIT)
452 		smc->sk.sk_state = SMC_ACTIVE;
453 	return 0;
454 }
455 
456 /* decline and fall back during connect */
457 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code)
458 {
459 	int rc;
460 
461 	if (reason_code < 0) { /* error, fallback is not possible */
462 		if (smc->sk.sk_state == SMC_INIT)
463 			sock_put(&smc->sk); /* passive closing */
464 		return reason_code;
465 	}
466 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
467 		rc = smc_clc_send_decline(smc, reason_code);
468 		if (rc < 0) {
469 			if (smc->sk.sk_state == SMC_INIT)
470 				sock_put(&smc->sk); /* passive closing */
471 			return rc;
472 		}
473 	}
474 	return smc_connect_fallback(smc, reason_code);
475 }
476 
477 /* abort connecting */
478 static int smc_connect_abort(struct smc_sock *smc, int reason_code,
479 			     int local_contact)
480 {
481 	if (local_contact == SMC_FIRST_CONTACT)
482 		smc_lgr_forget(smc->conn.lgr);
483 	if (smc->conn.lgr->is_smcd)
484 		/* there is only one lgr role for SMC-D; use server lock */
485 		mutex_unlock(&smc_server_lgr_pending);
486 	else
487 		mutex_unlock(&smc_client_lgr_pending);
488 
489 	smc_conn_free(&smc->conn);
490 	return reason_code;
491 }
492 
493 /* check if there is a rdma device available for this connection. */
494 /* called for connect and listen */
495 static int smc_check_rdma(struct smc_sock *smc, struct smc_ib_device **ibdev,
496 			  u8 *ibport, unsigned short vlan_id, u8 gid[])
497 {
498 	int reason_code = 0;
499 
500 	/* PNET table look up: search active ib_device and port
501 	 * within same PNETID that also contains the ethernet device
502 	 * used for the internal TCP socket
503 	 */
504 	smc_pnet_find_roce_resource(smc->clcsock->sk, ibdev, ibport, vlan_id,
505 				    gid);
506 	if (!(*ibdev))
507 		reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
508 
509 	return reason_code;
510 }
511 
512 /* check if there is an ISM device available for this connection. */
513 /* called for connect and listen */
514 static int smc_check_ism(struct smc_sock *smc, struct smcd_dev **ismdev)
515 {
516 	/* Find ISM device with same PNETID as connecting interface  */
517 	smc_pnet_find_ism_resource(smc->clcsock->sk, ismdev);
518 	if (!(*ismdev))
519 		return SMC_CLC_DECL_CNFERR; /* configuration error */
520 	return 0;
521 }
522 
523 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
524 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
525 				      struct smcd_dev *ismdev,
526 				      unsigned short vlan_id)
527 {
528 	if (vlan_id && smc_ism_get_vlan(ismdev, vlan_id))
529 		return SMC_CLC_DECL_CNFERR;
530 	return 0;
531 }
532 
533 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
534  * used, the VLAN ID will be registered again during the connection setup.
535  */
536 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc, bool is_smcd,
537 					struct smcd_dev *ismdev,
538 					unsigned short vlan_id)
539 {
540 	if (!is_smcd)
541 		return 0;
542 	if (vlan_id && smc_ism_put_vlan(ismdev, vlan_id))
543 		return SMC_CLC_DECL_CNFERR;
544 	return 0;
545 }
546 
547 /* CLC handshake during connect */
548 static int smc_connect_clc(struct smc_sock *smc, int smc_type,
549 			   struct smc_clc_msg_accept_confirm *aclc,
550 			   struct smc_ib_device *ibdev, u8 ibport,
551 			   u8 gid[], struct smcd_dev *ismdev)
552 {
553 	int rc = 0;
554 
555 	/* do inband token exchange */
556 	rc = smc_clc_send_proposal(smc, smc_type, ibdev, ibport, gid, ismdev);
557 	if (rc)
558 		return rc;
559 	/* receive SMC Accept CLC message */
560 	return smc_clc_wait_msg(smc, aclc, sizeof(*aclc), SMC_CLC_ACCEPT,
561 				CLC_WAIT_TIME);
562 }
563 
564 /* setup for RDMA connection of client */
565 static int smc_connect_rdma(struct smc_sock *smc,
566 			    struct smc_clc_msg_accept_confirm *aclc,
567 			    struct smc_ib_device *ibdev, u8 ibport)
568 {
569 	int local_contact = SMC_FIRST_CONTACT;
570 	struct smc_link *link;
571 	int reason_code = 0;
572 
573 	mutex_lock(&smc_client_lgr_pending);
574 	local_contact = smc_conn_create(smc, false, aclc->hdr.flag, ibdev,
575 					ibport, ntoh24(aclc->qpn), &aclc->lcl,
576 					NULL, 0);
577 	if (local_contact < 0) {
578 		if (local_contact == -ENOMEM)
579 			reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
580 		else if (local_contact == -ENOLINK)
581 			reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
582 		else
583 			reason_code = SMC_CLC_DECL_INTERR; /* other error */
584 		mutex_unlock(&smc_client_lgr_pending);
585 		return reason_code;
586 	}
587 	link = &smc->conn.lgr->lnk[SMC_SINGLE_LINK];
588 
589 	smc_conn_save_peer_info(smc, aclc);
590 
591 	/* create send buffer and rmb */
592 	if (smc_buf_create(smc, false))
593 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM, local_contact);
594 
595 	if (local_contact == SMC_FIRST_CONTACT)
596 		smc_link_save_peer_info(link, aclc);
597 
598 	if (smc_rmb_rtoken_handling(&smc->conn, aclc))
599 		return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RTOK,
600 					 local_contact);
601 
602 	smc_close_init(smc);
603 	smc_rx_init(smc);
604 
605 	if (local_contact == SMC_FIRST_CONTACT) {
606 		if (smc_ib_ready_link(link))
607 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RDYLNK,
608 						 local_contact);
609 	} else {
610 		if (smc_reg_rmb(link, smc->conn.rmb_desc, true))
611 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_REGRMB,
612 						 local_contact);
613 	}
614 	smc_rmb_sync_sg_for_device(&smc->conn);
615 
616 	reason_code = smc_clc_send_confirm(smc);
617 	if (reason_code)
618 		return smc_connect_abort(smc, reason_code, local_contact);
619 
620 	smc_tx_init(smc);
621 
622 	if (local_contact == SMC_FIRST_CONTACT) {
623 		/* QP confirmation over RoCE fabric */
624 		reason_code = smc_clnt_conf_first_link(smc);
625 		if (reason_code)
626 			return smc_connect_abort(smc, reason_code,
627 						 local_contact);
628 	}
629 	mutex_unlock(&smc_client_lgr_pending);
630 
631 	smc_copy_sock_settings_to_clc(smc);
632 	if (smc->sk.sk_state == SMC_INIT)
633 		smc->sk.sk_state = SMC_ACTIVE;
634 
635 	return 0;
636 }
637 
638 /* setup for ISM connection of client */
639 static int smc_connect_ism(struct smc_sock *smc,
640 			   struct smc_clc_msg_accept_confirm *aclc,
641 			   struct smcd_dev *ismdev)
642 {
643 	int local_contact = SMC_FIRST_CONTACT;
644 	int rc = 0;
645 
646 	/* there is only one lgr role for SMC-D; use server lock */
647 	mutex_lock(&smc_server_lgr_pending);
648 	local_contact = smc_conn_create(smc, true, aclc->hdr.flag, NULL, 0, 0,
649 					NULL, ismdev, aclc->gid);
650 	if (local_contact < 0) {
651 		mutex_unlock(&smc_server_lgr_pending);
652 		return SMC_CLC_DECL_MEM;
653 	}
654 
655 	/* Create send and receive buffers */
656 	if (smc_buf_create(smc, true))
657 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM, local_contact);
658 
659 	smc_conn_save_peer_info(smc, aclc);
660 	smc_close_init(smc);
661 	smc_rx_init(smc);
662 	smc_tx_init(smc);
663 
664 	rc = smc_clc_send_confirm(smc);
665 	if (rc)
666 		return smc_connect_abort(smc, rc, local_contact);
667 	mutex_unlock(&smc_server_lgr_pending);
668 
669 	smc_copy_sock_settings_to_clc(smc);
670 	if (smc->sk.sk_state == SMC_INIT)
671 		smc->sk.sk_state = SMC_ACTIVE;
672 
673 	return 0;
674 }
675 
676 /* perform steps before actually connecting */
677 static int __smc_connect(struct smc_sock *smc)
678 {
679 	bool ism_supported = false, rdma_supported = false;
680 	struct smc_clc_msg_accept_confirm aclc;
681 	struct smc_ib_device *ibdev;
682 	struct smcd_dev *ismdev;
683 	u8 gid[SMC_GID_SIZE];
684 	unsigned short vlan;
685 	int smc_type;
686 	int rc = 0;
687 	u8 ibport;
688 
689 	sock_hold(&smc->sk); /* sock put in passive closing */
690 
691 	if (smc->use_fallback)
692 		return smc_connect_fallback(smc, smc->fallback_rsn);
693 
694 	/* if peer has not signalled SMC-capability, fall back */
695 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
696 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
697 
698 	/* IPSec connections opt out of SMC-R optimizations */
699 	if (using_ipsec(smc))
700 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC);
701 
702 	/* check for VLAN ID */
703 	if (smc_vlan_by_tcpsk(smc->clcsock, &vlan))
704 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_CNFERR);
705 
706 	/* check if there is an ism device available */
707 	if (!smc_check_ism(smc, &ismdev) &&
708 	    !smc_connect_ism_vlan_setup(smc, ismdev, vlan)) {
709 		/* ISM is supported for this connection */
710 		ism_supported = true;
711 		smc_type = SMC_TYPE_D;
712 	}
713 
714 	/* check if there is a rdma device available */
715 	if (!smc_check_rdma(smc, &ibdev, &ibport, vlan, gid)) {
716 		/* RDMA is supported for this connection */
717 		rdma_supported = true;
718 		if (ism_supported)
719 			smc_type = SMC_TYPE_B; /* both */
720 		else
721 			smc_type = SMC_TYPE_R; /* only RDMA */
722 	}
723 
724 	/* if neither ISM nor RDMA are supported, fallback */
725 	if (!rdma_supported && !ism_supported)
726 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_NOSMCDEV);
727 
728 	/* perform CLC handshake */
729 	rc = smc_connect_clc(smc, smc_type, &aclc, ibdev, ibport, gid, ismdev);
730 	if (rc) {
731 		smc_connect_ism_vlan_cleanup(smc, ism_supported, ismdev, vlan);
732 		return smc_connect_decline_fallback(smc, rc);
733 	}
734 
735 	/* depending on previous steps, connect using rdma or ism */
736 	if (rdma_supported && aclc.hdr.path == SMC_TYPE_R)
737 		rc = smc_connect_rdma(smc, &aclc, ibdev, ibport);
738 	else if (ism_supported && aclc.hdr.path == SMC_TYPE_D)
739 		rc = smc_connect_ism(smc, &aclc, ismdev);
740 	else
741 		rc = SMC_CLC_DECL_MODEUNSUPP;
742 	if (rc) {
743 		smc_connect_ism_vlan_cleanup(smc, ism_supported, ismdev, vlan);
744 		return smc_connect_decline_fallback(smc, rc);
745 	}
746 
747 	smc_connect_ism_vlan_cleanup(smc, ism_supported, ismdev, vlan);
748 	return 0;
749 }
750 
751 static void smc_connect_work(struct work_struct *work)
752 {
753 	struct smc_sock *smc = container_of(work, struct smc_sock,
754 					    connect_work);
755 	int rc;
756 
757 	lock_sock(&smc->sk);
758 	rc = kernel_connect(smc->clcsock, &smc->connect_info->addr,
759 			    smc->connect_info->alen, smc->connect_info->flags);
760 	if (smc->clcsock->sk->sk_err) {
761 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
762 		goto out;
763 	}
764 	if (rc < 0) {
765 		smc->sk.sk_err = -rc;
766 		goto out;
767 	}
768 
769 	rc = __smc_connect(smc);
770 	if (rc < 0)
771 		smc->sk.sk_err = -rc;
772 
773 out:
774 	if (smc->sk.sk_err)
775 		smc->sk.sk_state_change(&smc->sk);
776 	else
777 		smc->sk.sk_write_space(&smc->sk);
778 	kfree(smc->connect_info);
779 	smc->connect_info = NULL;
780 	release_sock(&smc->sk);
781 }
782 
783 static int smc_connect(struct socket *sock, struct sockaddr *addr,
784 		       int alen, int flags)
785 {
786 	struct sock *sk = sock->sk;
787 	struct smc_sock *smc;
788 	int rc = -EINVAL;
789 
790 	smc = smc_sk(sk);
791 
792 	/* separate smc parameter checking to be safe */
793 	if (alen < sizeof(addr->sa_family))
794 		goto out_err;
795 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
796 		goto out_err;
797 
798 	lock_sock(sk);
799 	switch (sk->sk_state) {
800 	default:
801 		goto out;
802 	case SMC_ACTIVE:
803 		rc = -EISCONN;
804 		goto out;
805 	case SMC_INIT:
806 		rc = 0;
807 		break;
808 	}
809 
810 	smc_copy_sock_settings_to_clc(smc);
811 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
812 	if (flags & O_NONBLOCK) {
813 		if (smc->connect_info) {
814 			rc = -EALREADY;
815 			goto out;
816 		}
817 		smc->connect_info = kzalloc(alen + 2 * sizeof(int), GFP_KERNEL);
818 		if (!smc->connect_info) {
819 			rc = -ENOMEM;
820 			goto out;
821 		}
822 		smc->connect_info->alen = alen;
823 		smc->connect_info->flags = flags ^ O_NONBLOCK;
824 		memcpy(&smc->connect_info->addr, addr, alen);
825 		schedule_work(&smc->connect_work);
826 		rc = -EINPROGRESS;
827 	} else {
828 		rc = kernel_connect(smc->clcsock, addr, alen, flags);
829 		if (rc)
830 			goto out;
831 
832 		rc = __smc_connect(smc);
833 		if (rc < 0)
834 			goto out;
835 		else
836 			rc = 0; /* success cases including fallback */
837 	}
838 
839 out:
840 	release_sock(sk);
841 out_err:
842 	return rc;
843 }
844 
845 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
846 {
847 	struct socket *new_clcsock = NULL;
848 	struct sock *lsk = &lsmc->sk;
849 	struct sock *new_sk;
850 	int rc = -EINVAL;
851 
852 	release_sock(lsk);
853 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
854 	if (!new_sk) {
855 		rc = -ENOMEM;
856 		lsk->sk_err = ENOMEM;
857 		*new_smc = NULL;
858 		lock_sock(lsk);
859 		goto out;
860 	}
861 	*new_smc = smc_sk(new_sk);
862 
863 	mutex_lock(&lsmc->clcsock_release_lock);
864 	if (lsmc->clcsock)
865 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
866 	mutex_unlock(&lsmc->clcsock_release_lock);
867 	lock_sock(lsk);
868 	if  (rc < 0)
869 		lsk->sk_err = -rc;
870 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
871 		if (new_clcsock)
872 			sock_release(new_clcsock);
873 		new_sk->sk_state = SMC_CLOSED;
874 		sock_set_flag(new_sk, SOCK_DEAD);
875 		new_sk->sk_prot->unhash(new_sk);
876 		sock_put(new_sk); /* final */
877 		*new_smc = NULL;
878 		goto out;
879 	}
880 
881 	(*new_smc)->clcsock = new_clcsock;
882 out:
883 	return rc;
884 }
885 
886 /* add a just created sock to the accept queue of the listen sock as
887  * candidate for a following socket accept call from user space
888  */
889 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
890 {
891 	struct smc_sock *par = smc_sk(parent);
892 
893 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
894 	spin_lock(&par->accept_q_lock);
895 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
896 	spin_unlock(&par->accept_q_lock);
897 	sk_acceptq_added(parent);
898 }
899 
900 /* remove a socket from the accept queue of its parental listening socket */
901 static void smc_accept_unlink(struct sock *sk)
902 {
903 	struct smc_sock *par = smc_sk(sk)->listen_smc;
904 
905 	spin_lock(&par->accept_q_lock);
906 	list_del_init(&smc_sk(sk)->accept_q);
907 	spin_unlock(&par->accept_q_lock);
908 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
909 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
910 }
911 
912 /* remove a sock from the accept queue to bind it to a new socket created
913  * for a socket accept call from user space
914  */
915 struct sock *smc_accept_dequeue(struct sock *parent,
916 				struct socket *new_sock)
917 {
918 	struct smc_sock *isk, *n;
919 	struct sock *new_sk;
920 
921 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
922 		new_sk = (struct sock *)isk;
923 
924 		smc_accept_unlink(new_sk);
925 		if (new_sk->sk_state == SMC_CLOSED) {
926 			if (isk->clcsock) {
927 				sock_release(isk->clcsock);
928 				isk->clcsock = NULL;
929 			}
930 			new_sk->sk_prot->unhash(new_sk);
931 			sock_put(new_sk); /* final */
932 			continue;
933 		}
934 		if (new_sock)
935 			sock_graft(new_sk, new_sock);
936 		return new_sk;
937 	}
938 	return NULL;
939 }
940 
941 /* clean up for a created but never accepted sock */
942 void smc_close_non_accepted(struct sock *sk)
943 {
944 	struct smc_sock *smc = smc_sk(sk);
945 
946 	lock_sock(sk);
947 	if (!sk->sk_lingertime)
948 		/* wait for peer closing */
949 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
950 	if (!smc->use_fallback) {
951 		smc_close_active(smc);
952 		sock_set_flag(sk, SOCK_DEAD);
953 		sk->sk_shutdown |= SHUTDOWN_MASK;
954 	}
955 	if (smc->clcsock) {
956 		struct socket *tcp;
957 
958 		tcp = smc->clcsock;
959 		smc->clcsock = NULL;
960 		sock_release(tcp);
961 	}
962 	if (smc->use_fallback) {
963 		sock_put(sk); /* passive closing */
964 		sk->sk_state = SMC_CLOSED;
965 	} else {
966 		if (sk->sk_state == SMC_CLOSED)
967 			smc_conn_free(&smc->conn);
968 	}
969 	release_sock(sk);
970 	sk->sk_prot->unhash(sk);
971 	sock_put(sk); /* final sock_put */
972 }
973 
974 static int smc_serv_conf_first_link(struct smc_sock *smc)
975 {
976 	struct net *net = sock_net(smc->clcsock->sk);
977 	struct smc_link_group *lgr = smc->conn.lgr;
978 	struct smc_link *link;
979 	int rest;
980 	int rc;
981 
982 	link = &lgr->lnk[SMC_SINGLE_LINK];
983 
984 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
985 		return SMC_CLC_DECL_ERR_REGRMB;
986 
987 	/* send CONFIRM LINK request to client over the RoCE fabric */
988 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
989 	if (rc < 0)
990 		return SMC_CLC_DECL_TIMEOUT_CL;
991 
992 	/* receive CONFIRM LINK response from client over the RoCE fabric */
993 	rest = wait_for_completion_interruptible_timeout(
994 		&link->llc_confirm_resp,
995 		SMC_LLC_WAIT_FIRST_TIME);
996 	if (rest <= 0) {
997 		struct smc_clc_msg_decline dclc;
998 
999 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1000 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1001 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
1002 	}
1003 
1004 	if (link->llc_confirm_resp_rc)
1005 		return SMC_CLC_DECL_RMBE_EC;
1006 
1007 	/* send ADD LINK request to client over the RoCE fabric */
1008 	rc = smc_llc_send_add_link(link,
1009 				   link->smcibdev->mac[link->ibport - 1],
1010 				   link->gid, SMC_LLC_REQ);
1011 	if (rc < 0)
1012 		return SMC_CLC_DECL_TIMEOUT_AL;
1013 
1014 	/* receive ADD LINK response from client over the RoCE fabric */
1015 	rest = wait_for_completion_interruptible_timeout(&link->llc_add_resp,
1016 							 SMC_LLC_WAIT_TIME);
1017 	if (rest <= 0) {
1018 		struct smc_clc_msg_decline dclc;
1019 
1020 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1021 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1022 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_AL : rc;
1023 	}
1024 
1025 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
1026 
1027 	return 0;
1028 }
1029 
1030 /* listen worker: finish */
1031 static void smc_listen_out(struct smc_sock *new_smc)
1032 {
1033 	struct smc_sock *lsmc = new_smc->listen_smc;
1034 	struct sock *newsmcsk = &new_smc->sk;
1035 
1036 	lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1037 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1038 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1039 	} else { /* no longer listening */
1040 		smc_close_non_accepted(newsmcsk);
1041 	}
1042 	release_sock(&lsmc->sk);
1043 
1044 	/* Wake up accept */
1045 	lsmc->sk.sk_data_ready(&lsmc->sk);
1046 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1047 }
1048 
1049 /* listen worker: finish in state connected */
1050 static void smc_listen_out_connected(struct smc_sock *new_smc)
1051 {
1052 	struct sock *newsmcsk = &new_smc->sk;
1053 
1054 	sk_refcnt_debug_inc(newsmcsk);
1055 	if (newsmcsk->sk_state == SMC_INIT)
1056 		newsmcsk->sk_state = SMC_ACTIVE;
1057 
1058 	smc_listen_out(new_smc);
1059 }
1060 
1061 /* listen worker: finish in error state */
1062 static void smc_listen_out_err(struct smc_sock *new_smc)
1063 {
1064 	struct sock *newsmcsk = &new_smc->sk;
1065 
1066 	if (newsmcsk->sk_state == SMC_INIT)
1067 		sock_put(&new_smc->sk); /* passive closing */
1068 	newsmcsk->sk_state = SMC_CLOSED;
1069 	smc_conn_free(&new_smc->conn);
1070 
1071 	smc_listen_out(new_smc);
1072 }
1073 
1074 /* listen worker: decline and fall back if possible */
1075 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1076 			       int local_contact)
1077 {
1078 	/* RDMA setup failed, switch back to TCP */
1079 	if (local_contact == SMC_FIRST_CONTACT)
1080 		smc_lgr_forget(new_smc->conn.lgr);
1081 	if (reason_code < 0) { /* error, no fallback possible */
1082 		smc_listen_out_err(new_smc);
1083 		return;
1084 	}
1085 	smc_conn_free(&new_smc->conn);
1086 	new_smc->use_fallback = true;
1087 	new_smc->fallback_rsn = reason_code;
1088 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1089 		if (smc_clc_send_decline(new_smc, reason_code) < 0) {
1090 			smc_listen_out_err(new_smc);
1091 			return;
1092 		}
1093 	}
1094 	smc_listen_out_connected(new_smc);
1095 }
1096 
1097 /* listen worker: check prefixes */
1098 static int smc_listen_rdma_check(struct smc_sock *new_smc,
1099 				 struct smc_clc_msg_proposal *pclc)
1100 {
1101 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1102 	struct socket *newclcsock = new_smc->clcsock;
1103 
1104 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1105 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1106 		return SMC_CLC_DECL_CNFERR;
1107 
1108 	return 0;
1109 }
1110 
1111 /* listen worker: initialize connection and buffers */
1112 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1113 				struct smc_clc_msg_proposal *pclc,
1114 				struct smc_ib_device *ibdev, u8 ibport,
1115 				int *local_contact)
1116 {
1117 	/* allocate connection / link group */
1118 	*local_contact = smc_conn_create(new_smc, false, 0, ibdev, ibport, 0,
1119 					 &pclc->lcl, NULL, 0);
1120 	if (*local_contact < 0) {
1121 		if (*local_contact == -ENOMEM)
1122 			return SMC_CLC_DECL_MEM;/* insufficient memory*/
1123 		return SMC_CLC_DECL_INTERR; /* other error */
1124 	}
1125 
1126 	/* create send buffer and rmb */
1127 	if (smc_buf_create(new_smc, false))
1128 		return SMC_CLC_DECL_MEM;
1129 
1130 	return 0;
1131 }
1132 
1133 /* listen worker: initialize connection and buffers for SMC-D */
1134 static int smc_listen_ism_init(struct smc_sock *new_smc,
1135 			       struct smc_clc_msg_proposal *pclc,
1136 			       struct smcd_dev *ismdev,
1137 			       int *local_contact)
1138 {
1139 	struct smc_clc_msg_smcd *pclc_smcd;
1140 
1141 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
1142 	*local_contact = smc_conn_create(new_smc, true, 0, NULL, 0, 0, NULL,
1143 					 ismdev, pclc_smcd->gid);
1144 	if (*local_contact < 0) {
1145 		if (*local_contact == -ENOMEM)
1146 			return SMC_CLC_DECL_MEM;/* insufficient memory*/
1147 		return SMC_CLC_DECL_INTERR; /* other error */
1148 	}
1149 
1150 	/* Check if peer can be reached via ISM device */
1151 	if (smc_ism_cantalk(new_smc->conn.lgr->peer_gid,
1152 			    new_smc->conn.lgr->vlan_id,
1153 			    new_smc->conn.lgr->smcd)) {
1154 		if (*local_contact == SMC_FIRST_CONTACT)
1155 			smc_lgr_forget(new_smc->conn.lgr);
1156 		smc_conn_free(&new_smc->conn);
1157 		return SMC_CLC_DECL_CNFERR;
1158 	}
1159 
1160 	/* Create send and receive buffers */
1161 	if (smc_buf_create(new_smc, true)) {
1162 		if (*local_contact == SMC_FIRST_CONTACT)
1163 			smc_lgr_forget(new_smc->conn.lgr);
1164 		smc_conn_free(&new_smc->conn);
1165 		return SMC_CLC_DECL_MEM;
1166 	}
1167 
1168 	return 0;
1169 }
1170 
1171 /* listen worker: register buffers */
1172 static int smc_listen_rdma_reg(struct smc_sock *new_smc, int local_contact)
1173 {
1174 	struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
1175 
1176 	if (local_contact != SMC_FIRST_CONTACT) {
1177 		if (smc_reg_rmb(link, new_smc->conn.rmb_desc, true))
1178 			return SMC_CLC_DECL_ERR_REGRMB;
1179 	}
1180 	smc_rmb_sync_sg_for_device(&new_smc->conn);
1181 
1182 	return 0;
1183 }
1184 
1185 /* listen worker: finish RDMA setup */
1186 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
1187 				  struct smc_clc_msg_accept_confirm *cclc,
1188 				  int local_contact)
1189 {
1190 	struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
1191 	int reason_code = 0;
1192 
1193 	if (local_contact == SMC_FIRST_CONTACT)
1194 		smc_link_save_peer_info(link, cclc);
1195 
1196 	if (smc_rmb_rtoken_handling(&new_smc->conn, cclc)) {
1197 		reason_code = SMC_CLC_DECL_ERR_RTOK;
1198 		goto decline;
1199 	}
1200 
1201 	if (local_contact == SMC_FIRST_CONTACT) {
1202 		if (smc_ib_ready_link(link)) {
1203 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
1204 			goto decline;
1205 		}
1206 		/* QP confirmation over RoCE fabric */
1207 		reason_code = smc_serv_conf_first_link(new_smc);
1208 		if (reason_code)
1209 			goto decline;
1210 	}
1211 	return 0;
1212 
1213 decline:
1214 	smc_listen_decline(new_smc, reason_code, local_contact);
1215 	return reason_code;
1216 }
1217 
1218 /* setup for RDMA connection of server */
1219 static void smc_listen_work(struct work_struct *work)
1220 {
1221 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
1222 						smc_listen_work);
1223 	struct socket *newclcsock = new_smc->clcsock;
1224 	struct smc_clc_msg_accept_confirm cclc;
1225 	struct smc_clc_msg_proposal *pclc;
1226 	struct smc_ib_device *ibdev;
1227 	bool ism_supported = false;
1228 	struct smcd_dev *ismdev;
1229 	u8 buf[SMC_CLC_MAX_LEN];
1230 	int local_contact = 0;
1231 	unsigned short vlan;
1232 	int reason_code = 0;
1233 	int rc = 0;
1234 	u8 ibport;
1235 
1236 	if (new_smc->use_fallback) {
1237 		smc_listen_out_connected(new_smc);
1238 		return;
1239 	}
1240 
1241 	/* check if peer is smc capable */
1242 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
1243 		new_smc->use_fallback = true;
1244 		new_smc->fallback_rsn = SMC_CLC_DECL_PEERNOSMC;
1245 		smc_listen_out_connected(new_smc);
1246 		return;
1247 	}
1248 
1249 	/* do inband token exchange -
1250 	 * wait for and receive SMC Proposal CLC message
1251 	 */
1252 	pclc = (struct smc_clc_msg_proposal *)&buf;
1253 	reason_code = smc_clc_wait_msg(new_smc, pclc, SMC_CLC_MAX_LEN,
1254 				       SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
1255 	if (reason_code) {
1256 		smc_listen_decline(new_smc, reason_code, 0);
1257 		return;
1258 	}
1259 
1260 	/* IPSec connections opt out of SMC-R optimizations */
1261 	if (using_ipsec(new_smc)) {
1262 		smc_listen_decline(new_smc, SMC_CLC_DECL_IPSEC, 0);
1263 		return;
1264 	}
1265 
1266 	mutex_lock(&smc_server_lgr_pending);
1267 	smc_close_init(new_smc);
1268 	smc_rx_init(new_smc);
1269 	smc_tx_init(new_smc);
1270 
1271 	/* check if ISM is available */
1272 	if ((pclc->hdr.path == SMC_TYPE_D || pclc->hdr.path == SMC_TYPE_B) &&
1273 	    !smc_check_ism(new_smc, &ismdev) &&
1274 	    !smc_listen_ism_init(new_smc, pclc, ismdev, &local_contact)) {
1275 		ism_supported = true;
1276 	}
1277 
1278 	/* check if RDMA is available */
1279 	if (!ism_supported &&
1280 	    ((pclc->hdr.path != SMC_TYPE_R && pclc->hdr.path != SMC_TYPE_B) ||
1281 	     smc_vlan_by_tcpsk(new_smc->clcsock, &vlan) ||
1282 	     smc_check_rdma(new_smc, &ibdev, &ibport, vlan, NULL) ||
1283 	     smc_listen_rdma_check(new_smc, pclc) ||
1284 	     smc_listen_rdma_init(new_smc, pclc, ibdev, ibport,
1285 				  &local_contact) ||
1286 	     smc_listen_rdma_reg(new_smc, local_contact))) {
1287 		/* SMC not supported, decline */
1288 		mutex_unlock(&smc_server_lgr_pending);
1289 		smc_listen_decline(new_smc, SMC_CLC_DECL_MODEUNSUPP,
1290 				   local_contact);
1291 		return;
1292 	}
1293 
1294 	/* send SMC Accept CLC message */
1295 	rc = smc_clc_send_accept(new_smc, local_contact);
1296 	if (rc) {
1297 		mutex_unlock(&smc_server_lgr_pending);
1298 		smc_listen_decline(new_smc, rc, local_contact);
1299 		return;
1300 	}
1301 
1302 	/* SMC-D does not need this lock any more */
1303 	if (ism_supported)
1304 		mutex_unlock(&smc_server_lgr_pending);
1305 
1306 	/* receive SMC Confirm CLC message */
1307 	reason_code = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
1308 				       SMC_CLC_CONFIRM, CLC_WAIT_TIME);
1309 	if (reason_code) {
1310 		if (!ism_supported)
1311 			mutex_unlock(&smc_server_lgr_pending);
1312 		smc_listen_decline(new_smc, reason_code, local_contact);
1313 		return;
1314 	}
1315 
1316 	/* finish worker */
1317 	if (!ism_supported) {
1318 		rc = smc_listen_rdma_finish(new_smc, &cclc, local_contact);
1319 		mutex_unlock(&smc_server_lgr_pending);
1320 		if (rc)
1321 			return;
1322 	}
1323 	smc_conn_save_peer_info(new_smc, &cclc);
1324 	smc_listen_out_connected(new_smc);
1325 }
1326 
1327 static void smc_tcp_listen_work(struct work_struct *work)
1328 {
1329 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
1330 					     tcp_listen_work);
1331 	struct sock *lsk = &lsmc->sk;
1332 	struct smc_sock *new_smc;
1333 	int rc = 0;
1334 
1335 	lock_sock(lsk);
1336 	while (lsk->sk_state == SMC_LISTEN) {
1337 		rc = smc_clcsock_accept(lsmc, &new_smc);
1338 		if (rc)
1339 			goto out;
1340 		if (!new_smc)
1341 			continue;
1342 
1343 		new_smc->listen_smc = lsmc;
1344 		new_smc->use_fallback = lsmc->use_fallback;
1345 		new_smc->fallback_rsn = lsmc->fallback_rsn;
1346 		sock_hold(lsk); /* sock_put in smc_listen_work */
1347 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
1348 		smc_copy_sock_settings_to_smc(new_smc);
1349 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
1350 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
1351 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
1352 		if (!schedule_work(&new_smc->smc_listen_work))
1353 			sock_put(&new_smc->sk);
1354 	}
1355 
1356 out:
1357 	release_sock(lsk);
1358 	sock_put(&lsmc->sk); /* sock_hold in smc_listen */
1359 }
1360 
1361 static int smc_listen(struct socket *sock, int backlog)
1362 {
1363 	struct sock *sk = sock->sk;
1364 	struct smc_sock *smc;
1365 	int rc;
1366 
1367 	smc = smc_sk(sk);
1368 	lock_sock(sk);
1369 
1370 	rc = -EINVAL;
1371 	if ((sk->sk_state != SMC_INIT) && (sk->sk_state != SMC_LISTEN))
1372 		goto out;
1373 
1374 	rc = 0;
1375 	if (sk->sk_state == SMC_LISTEN) {
1376 		sk->sk_max_ack_backlog = backlog;
1377 		goto out;
1378 	}
1379 	/* some socket options are handled in core, so we could not apply
1380 	 * them to the clc socket -- copy smc socket options to clc socket
1381 	 */
1382 	smc_copy_sock_settings_to_clc(smc);
1383 	if (!smc->use_fallback)
1384 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1385 
1386 	rc = kernel_listen(smc->clcsock, backlog);
1387 	if (rc)
1388 		goto out;
1389 	sk->sk_max_ack_backlog = backlog;
1390 	sk->sk_ack_backlog = 0;
1391 	sk->sk_state = SMC_LISTEN;
1392 	sock_hold(sk); /* sock_hold in tcp_listen_worker */
1393 	if (!schedule_work(&smc->tcp_listen_work))
1394 		sock_put(sk);
1395 
1396 out:
1397 	release_sock(sk);
1398 	return rc;
1399 }
1400 
1401 static int smc_accept(struct socket *sock, struct socket *new_sock,
1402 		      int flags, bool kern)
1403 {
1404 	struct sock *sk = sock->sk, *nsk;
1405 	DECLARE_WAITQUEUE(wait, current);
1406 	struct smc_sock *lsmc;
1407 	long timeo;
1408 	int rc = 0;
1409 
1410 	lsmc = smc_sk(sk);
1411 	sock_hold(sk); /* sock_put below */
1412 	lock_sock(sk);
1413 
1414 	if (lsmc->sk.sk_state != SMC_LISTEN) {
1415 		rc = -EINVAL;
1416 		release_sock(sk);
1417 		goto out;
1418 	}
1419 
1420 	/* Wait for an incoming connection */
1421 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1422 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
1423 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1424 		set_current_state(TASK_INTERRUPTIBLE);
1425 		if (!timeo) {
1426 			rc = -EAGAIN;
1427 			break;
1428 		}
1429 		release_sock(sk);
1430 		timeo = schedule_timeout(timeo);
1431 		/* wakeup by sk_data_ready in smc_listen_work() */
1432 		sched_annotate_sleep();
1433 		lock_sock(sk);
1434 		if (signal_pending(current)) {
1435 			rc = sock_intr_errno(timeo);
1436 			break;
1437 		}
1438 	}
1439 	set_current_state(TASK_RUNNING);
1440 	remove_wait_queue(sk_sleep(sk), &wait);
1441 
1442 	if (!rc)
1443 		rc = sock_error(nsk);
1444 	release_sock(sk);
1445 	if (rc)
1446 		goto out;
1447 
1448 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
1449 		/* wait till data arrives on the socket */
1450 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
1451 								MSEC_PER_SEC);
1452 		if (smc_sk(nsk)->use_fallback) {
1453 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
1454 
1455 			lock_sock(clcsk);
1456 			if (skb_queue_empty(&clcsk->sk_receive_queue))
1457 				sk_wait_data(clcsk, &timeo, NULL);
1458 			release_sock(clcsk);
1459 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
1460 			lock_sock(nsk);
1461 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
1462 			release_sock(nsk);
1463 		}
1464 	}
1465 
1466 out:
1467 	sock_put(sk); /* sock_hold above */
1468 	return rc;
1469 }
1470 
1471 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1472 		       int peer)
1473 {
1474 	struct smc_sock *smc;
1475 
1476 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
1477 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
1478 		return -ENOTCONN;
1479 
1480 	smc = smc_sk(sock->sk);
1481 
1482 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
1483 }
1484 
1485 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1486 {
1487 	struct sock *sk = sock->sk;
1488 	struct smc_sock *smc;
1489 	int rc = -EPIPE;
1490 
1491 	smc = smc_sk(sk);
1492 	lock_sock(sk);
1493 	if ((sk->sk_state != SMC_ACTIVE) &&
1494 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1495 	    (sk->sk_state != SMC_INIT))
1496 		goto out;
1497 
1498 	if (msg->msg_flags & MSG_FASTOPEN) {
1499 		if (sk->sk_state == SMC_INIT) {
1500 			smc->use_fallback = true;
1501 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1502 		} else {
1503 			rc = -EINVAL;
1504 			goto out;
1505 		}
1506 	}
1507 
1508 	if (smc->use_fallback)
1509 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
1510 	else
1511 		rc = smc_tx_sendmsg(smc, msg, len);
1512 out:
1513 	release_sock(sk);
1514 	return rc;
1515 }
1516 
1517 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1518 		       int flags)
1519 {
1520 	struct sock *sk = sock->sk;
1521 	struct smc_sock *smc;
1522 	int rc = -ENOTCONN;
1523 
1524 	smc = smc_sk(sk);
1525 	lock_sock(sk);
1526 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
1527 		/* socket was connected before, no more data to read */
1528 		rc = 0;
1529 		goto out;
1530 	}
1531 	if ((sk->sk_state == SMC_INIT) ||
1532 	    (sk->sk_state == SMC_LISTEN) ||
1533 	    (sk->sk_state == SMC_CLOSED))
1534 		goto out;
1535 
1536 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1537 		rc = 0;
1538 		goto out;
1539 	}
1540 
1541 	if (smc->use_fallback) {
1542 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
1543 	} else {
1544 		msg->msg_namelen = 0;
1545 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
1546 	}
1547 
1548 out:
1549 	release_sock(sk);
1550 	return rc;
1551 }
1552 
1553 static __poll_t smc_accept_poll(struct sock *parent)
1554 {
1555 	struct smc_sock *isk = smc_sk(parent);
1556 	__poll_t mask = 0;
1557 
1558 	spin_lock(&isk->accept_q_lock);
1559 	if (!list_empty(&isk->accept_q))
1560 		mask = EPOLLIN | EPOLLRDNORM;
1561 	spin_unlock(&isk->accept_q_lock);
1562 
1563 	return mask;
1564 }
1565 
1566 static __poll_t smc_poll(struct file *file, struct socket *sock,
1567 			     poll_table *wait)
1568 {
1569 	struct sock *sk = sock->sk;
1570 	__poll_t mask = 0;
1571 	struct smc_sock *smc;
1572 
1573 	if (!sk)
1574 		return EPOLLNVAL;
1575 
1576 	smc = smc_sk(sock->sk);
1577 	if (smc->use_fallback) {
1578 		/* delegate to CLC child sock */
1579 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
1580 		sk->sk_err = smc->clcsock->sk->sk_err;
1581 		if (sk->sk_err)
1582 			mask |= EPOLLERR;
1583 	} else {
1584 		if (sk->sk_state != SMC_CLOSED)
1585 			sock_poll_wait(file, sock, wait);
1586 		if (sk->sk_err)
1587 			mask |= EPOLLERR;
1588 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1589 		    (sk->sk_state == SMC_CLOSED))
1590 			mask |= EPOLLHUP;
1591 		if (sk->sk_state == SMC_LISTEN) {
1592 			/* woken up by sk_data_ready in smc_listen_work() */
1593 			mask = smc_accept_poll(sk);
1594 		} else {
1595 			if (atomic_read(&smc->conn.sndbuf_space) ||
1596 			    sk->sk_shutdown & SEND_SHUTDOWN) {
1597 				mask |= EPOLLOUT | EPOLLWRNORM;
1598 			} else {
1599 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1600 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1601 			}
1602 			if (atomic_read(&smc->conn.bytes_to_rcv))
1603 				mask |= EPOLLIN | EPOLLRDNORM;
1604 			if (sk->sk_shutdown & RCV_SHUTDOWN)
1605 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
1606 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
1607 				mask |= EPOLLIN;
1608 			if (smc->conn.urg_state == SMC_URG_VALID)
1609 				mask |= EPOLLPRI;
1610 		}
1611 	}
1612 
1613 	return mask;
1614 }
1615 
1616 static int smc_shutdown(struct socket *sock, int how)
1617 {
1618 	struct sock *sk = sock->sk;
1619 	struct smc_sock *smc;
1620 	int rc = -EINVAL;
1621 	int rc1 = 0;
1622 
1623 	smc = smc_sk(sk);
1624 
1625 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
1626 		return rc;
1627 
1628 	lock_sock(sk);
1629 
1630 	rc = -ENOTCONN;
1631 	if ((sk->sk_state != SMC_ACTIVE) &&
1632 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
1633 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
1634 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1635 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
1636 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
1637 		goto out;
1638 	if (smc->use_fallback) {
1639 		rc = kernel_sock_shutdown(smc->clcsock, how);
1640 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
1641 		if (sk->sk_shutdown == SHUTDOWN_MASK)
1642 			sk->sk_state = SMC_CLOSED;
1643 		goto out;
1644 	}
1645 	switch (how) {
1646 	case SHUT_RDWR:		/* shutdown in both directions */
1647 		rc = smc_close_active(smc);
1648 		break;
1649 	case SHUT_WR:
1650 		rc = smc_close_shutdown_write(smc);
1651 		break;
1652 	case SHUT_RD:
1653 		rc = 0;
1654 		/* nothing more to do because peer is not involved */
1655 		break;
1656 	}
1657 	if (smc->clcsock)
1658 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
1659 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
1660 	sk->sk_shutdown |= how + 1;
1661 
1662 out:
1663 	release_sock(sk);
1664 	return rc ? rc : rc1;
1665 }
1666 
1667 static int smc_setsockopt(struct socket *sock, int level, int optname,
1668 			  char __user *optval, unsigned int optlen)
1669 {
1670 	struct sock *sk = sock->sk;
1671 	struct smc_sock *smc;
1672 	int val, rc;
1673 
1674 	smc = smc_sk(sk);
1675 
1676 	/* generic setsockopts reaching us here always apply to the
1677 	 * CLC socket
1678 	 */
1679 	rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
1680 					   optval, optlen);
1681 	if (smc->clcsock->sk->sk_err) {
1682 		sk->sk_err = smc->clcsock->sk->sk_err;
1683 		sk->sk_error_report(sk);
1684 	}
1685 	if (rc)
1686 		return rc;
1687 
1688 	if (optlen < sizeof(int))
1689 		return -EINVAL;
1690 	if (get_user(val, (int __user *)optval))
1691 		return -EFAULT;
1692 
1693 	lock_sock(sk);
1694 	switch (optname) {
1695 	case TCP_ULP:
1696 	case TCP_FASTOPEN:
1697 	case TCP_FASTOPEN_CONNECT:
1698 	case TCP_FASTOPEN_KEY:
1699 	case TCP_FASTOPEN_NO_COOKIE:
1700 		/* option not supported by SMC */
1701 		if (sk->sk_state == SMC_INIT) {
1702 			smc->use_fallback = true;
1703 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1704 		} else {
1705 			if (!smc->use_fallback)
1706 				rc = -EINVAL;
1707 		}
1708 		break;
1709 	case TCP_NODELAY:
1710 		if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1711 			if (val && !smc->use_fallback)
1712 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1713 						 0);
1714 		}
1715 		break;
1716 	case TCP_CORK:
1717 		if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1718 			if (!val && !smc->use_fallback)
1719 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1720 						 0);
1721 		}
1722 		break;
1723 	case TCP_DEFER_ACCEPT:
1724 		smc->sockopt_defer_accept = val;
1725 		break;
1726 	default:
1727 		break;
1728 	}
1729 	release_sock(sk);
1730 
1731 	return rc;
1732 }
1733 
1734 static int smc_getsockopt(struct socket *sock, int level, int optname,
1735 			  char __user *optval, int __user *optlen)
1736 {
1737 	struct smc_sock *smc;
1738 
1739 	smc = smc_sk(sock->sk);
1740 	/* socket options apply to the CLC socket */
1741 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
1742 					     optval, optlen);
1743 }
1744 
1745 static int smc_ioctl(struct socket *sock, unsigned int cmd,
1746 		     unsigned long arg)
1747 {
1748 	union smc_host_cursor cons, urg;
1749 	struct smc_connection *conn;
1750 	struct smc_sock *smc;
1751 	int answ;
1752 
1753 	smc = smc_sk(sock->sk);
1754 	conn = &smc->conn;
1755 	lock_sock(&smc->sk);
1756 	if (smc->use_fallback) {
1757 		if (!smc->clcsock) {
1758 			release_sock(&smc->sk);
1759 			return -EBADF;
1760 		}
1761 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
1762 		release_sock(&smc->sk);
1763 		return answ;
1764 	}
1765 	switch (cmd) {
1766 	case SIOCINQ: /* same as FIONREAD */
1767 		if (smc->sk.sk_state == SMC_LISTEN) {
1768 			release_sock(&smc->sk);
1769 			return -EINVAL;
1770 		}
1771 		if (smc->sk.sk_state == SMC_INIT ||
1772 		    smc->sk.sk_state == SMC_CLOSED)
1773 			answ = 0;
1774 		else
1775 			answ = atomic_read(&smc->conn.bytes_to_rcv);
1776 		break;
1777 	case SIOCOUTQ:
1778 		/* output queue size (not send + not acked) */
1779 		if (smc->sk.sk_state == SMC_LISTEN) {
1780 			release_sock(&smc->sk);
1781 			return -EINVAL;
1782 		}
1783 		if (smc->sk.sk_state == SMC_INIT ||
1784 		    smc->sk.sk_state == SMC_CLOSED)
1785 			answ = 0;
1786 		else
1787 			answ = smc->conn.sndbuf_desc->len -
1788 					atomic_read(&smc->conn.sndbuf_space);
1789 		break;
1790 	case SIOCOUTQNSD:
1791 		/* output queue size (not send only) */
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_tx_prepared_sends(&smc->conn);
1801 		break;
1802 	case SIOCATMARK:
1803 		if (smc->sk.sk_state == SMC_LISTEN) {
1804 			release_sock(&smc->sk);
1805 			return -EINVAL;
1806 		}
1807 		if (smc->sk.sk_state == SMC_INIT ||
1808 		    smc->sk.sk_state == SMC_CLOSED) {
1809 			answ = 0;
1810 		} else {
1811 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
1812 			smc_curs_copy(&urg, &conn->urg_curs, conn);
1813 			answ = smc_curs_diff(conn->rmb_desc->len,
1814 					     &cons, &urg) == 1;
1815 		}
1816 		break;
1817 	default:
1818 		release_sock(&smc->sk);
1819 		return -ENOIOCTLCMD;
1820 	}
1821 	release_sock(&smc->sk);
1822 
1823 	return put_user(answ, (int __user *)arg);
1824 }
1825 
1826 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
1827 			    int offset, size_t size, int flags)
1828 {
1829 	struct sock *sk = sock->sk;
1830 	struct smc_sock *smc;
1831 	int rc = -EPIPE;
1832 
1833 	smc = smc_sk(sk);
1834 	lock_sock(sk);
1835 	if (sk->sk_state != SMC_ACTIVE) {
1836 		release_sock(sk);
1837 		goto out;
1838 	}
1839 	release_sock(sk);
1840 	if (smc->use_fallback)
1841 		rc = kernel_sendpage(smc->clcsock, page, offset,
1842 				     size, flags);
1843 	else
1844 		rc = sock_no_sendpage(sock, page, offset, size, flags);
1845 
1846 out:
1847 	return rc;
1848 }
1849 
1850 /* Map the affected portions of the rmbe into an spd, note the number of bytes
1851  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
1852  * updates till whenever a respective page has been fully processed.
1853  * Note that subsequent recv() calls have to wait till all splice() processing
1854  * completed.
1855  */
1856 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
1857 			       struct pipe_inode_info *pipe, size_t len,
1858 			       unsigned int flags)
1859 {
1860 	struct sock *sk = sock->sk;
1861 	struct smc_sock *smc;
1862 	int rc = -ENOTCONN;
1863 
1864 	smc = smc_sk(sk);
1865 	lock_sock(sk);
1866 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
1867 		/* socket was connected before, no more data to read */
1868 		rc = 0;
1869 		goto out;
1870 	}
1871 	if (sk->sk_state == SMC_INIT ||
1872 	    sk->sk_state == SMC_LISTEN ||
1873 	    sk->sk_state == SMC_CLOSED)
1874 		goto out;
1875 
1876 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1877 		rc = 0;
1878 		goto out;
1879 	}
1880 
1881 	if (smc->use_fallback) {
1882 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
1883 						    pipe, len, flags);
1884 	} else {
1885 		if (*ppos) {
1886 			rc = -ESPIPE;
1887 			goto out;
1888 		}
1889 		if (flags & SPLICE_F_NONBLOCK)
1890 			flags = MSG_DONTWAIT;
1891 		else
1892 			flags = 0;
1893 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
1894 	}
1895 out:
1896 	release_sock(sk);
1897 
1898 	return rc;
1899 }
1900 
1901 /* must look like tcp */
1902 static const struct proto_ops smc_sock_ops = {
1903 	.family		= PF_SMC,
1904 	.owner		= THIS_MODULE,
1905 	.release	= smc_release,
1906 	.bind		= smc_bind,
1907 	.connect	= smc_connect,
1908 	.socketpair	= sock_no_socketpair,
1909 	.accept		= smc_accept,
1910 	.getname	= smc_getname,
1911 	.poll		= smc_poll,
1912 	.ioctl		= smc_ioctl,
1913 	.listen		= smc_listen,
1914 	.shutdown	= smc_shutdown,
1915 	.setsockopt	= smc_setsockopt,
1916 	.getsockopt	= smc_getsockopt,
1917 	.sendmsg	= smc_sendmsg,
1918 	.recvmsg	= smc_recvmsg,
1919 	.mmap		= sock_no_mmap,
1920 	.sendpage	= smc_sendpage,
1921 	.splice_read	= smc_splice_read,
1922 };
1923 
1924 static int smc_create(struct net *net, struct socket *sock, int protocol,
1925 		      int kern)
1926 {
1927 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
1928 	struct smc_sock *smc;
1929 	struct sock *sk;
1930 	int rc;
1931 
1932 	rc = -ESOCKTNOSUPPORT;
1933 	if (sock->type != SOCK_STREAM)
1934 		goto out;
1935 
1936 	rc = -EPROTONOSUPPORT;
1937 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
1938 		goto out;
1939 
1940 	rc = -ENOBUFS;
1941 	sock->ops = &smc_sock_ops;
1942 	sk = smc_sock_alloc(net, sock, protocol);
1943 	if (!sk)
1944 		goto out;
1945 
1946 	/* create internal TCP socket for CLC handshake and fallback */
1947 	smc = smc_sk(sk);
1948 	smc->use_fallback = false; /* assume rdma capability first */
1949 	smc->fallback_rsn = 0;
1950 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
1951 			      &smc->clcsock);
1952 	if (rc) {
1953 		sk_common_release(sk);
1954 		goto out;
1955 	}
1956 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
1957 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
1958 
1959 out:
1960 	return rc;
1961 }
1962 
1963 static const struct net_proto_family smc_sock_family_ops = {
1964 	.family	= PF_SMC,
1965 	.owner	= THIS_MODULE,
1966 	.create	= smc_create,
1967 };
1968 
1969 static int __init smc_init(void)
1970 {
1971 	int rc;
1972 
1973 	rc = smc_pnet_init();
1974 	if (rc)
1975 		return rc;
1976 
1977 	rc = smc_llc_init();
1978 	if (rc) {
1979 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
1980 		goto out_pnet;
1981 	}
1982 
1983 	rc = smc_cdc_init();
1984 	if (rc) {
1985 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
1986 		goto out_pnet;
1987 	}
1988 
1989 	rc = proto_register(&smc_proto, 1);
1990 	if (rc) {
1991 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
1992 		goto out_pnet;
1993 	}
1994 
1995 	rc = proto_register(&smc_proto6, 1);
1996 	if (rc) {
1997 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
1998 		goto out_proto;
1999 	}
2000 
2001 	rc = sock_register(&smc_sock_family_ops);
2002 	if (rc) {
2003 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
2004 		goto out_proto6;
2005 	}
2006 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
2007 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
2008 
2009 	rc = smc_ib_register_client();
2010 	if (rc) {
2011 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
2012 		goto out_sock;
2013 	}
2014 
2015 	static_branch_enable(&tcp_have_smc);
2016 	return 0;
2017 
2018 out_sock:
2019 	sock_unregister(PF_SMC);
2020 out_proto6:
2021 	proto_unregister(&smc_proto6);
2022 out_proto:
2023 	proto_unregister(&smc_proto);
2024 out_pnet:
2025 	smc_pnet_exit();
2026 	return rc;
2027 }
2028 
2029 static void __exit smc_exit(void)
2030 {
2031 	smc_core_exit();
2032 	static_branch_disable(&tcp_have_smc);
2033 	smc_ib_unregister_client();
2034 	sock_unregister(PF_SMC);
2035 	proto_unregister(&smc_proto6);
2036 	proto_unregister(&smc_proto);
2037 	smc_pnet_exit();
2038 }
2039 
2040 module_init(smc_init);
2041 module_exit(smc_exit);
2042 
2043 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
2044 MODULE_DESCRIPTION("smc socket address family");
2045 MODULE_LICENSE("GPL");
2046 MODULE_ALIAS_NETPROTO(PF_SMC);
2047