xref: /openbmc/linux/net/smc/af_smc.c (revision 176f011b)
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_create_lgr_pending);	/* serialize link group
46 						 * creation
47 						 */
48 
49 static void smc_tcp_listen_work(struct work_struct *);
50 static void smc_connect_work(struct work_struct *);
51 
52 static void smc_set_keepalive(struct sock *sk, int val)
53 {
54 	struct smc_sock *smc = smc_sk(sk);
55 
56 	smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
57 }
58 
59 static struct smc_hashinfo smc_v4_hashinfo = {
60 	.lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
61 };
62 
63 static struct smc_hashinfo smc_v6_hashinfo = {
64 	.lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
65 };
66 
67 int smc_hash_sk(struct sock *sk)
68 {
69 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
70 	struct hlist_head *head;
71 
72 	head = &h->ht;
73 
74 	write_lock_bh(&h->lock);
75 	sk_add_node(sk, head);
76 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
77 	write_unlock_bh(&h->lock);
78 
79 	return 0;
80 }
81 EXPORT_SYMBOL_GPL(smc_hash_sk);
82 
83 void smc_unhash_sk(struct sock *sk)
84 {
85 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
86 
87 	write_lock_bh(&h->lock);
88 	if (sk_del_node_init(sk))
89 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
90 	write_unlock_bh(&h->lock);
91 }
92 EXPORT_SYMBOL_GPL(smc_unhash_sk);
93 
94 struct proto smc_proto = {
95 	.name		= "SMC",
96 	.owner		= THIS_MODULE,
97 	.keepalive	= smc_set_keepalive,
98 	.hash		= smc_hash_sk,
99 	.unhash		= smc_unhash_sk,
100 	.obj_size	= sizeof(struct smc_sock),
101 	.h.smc_hash	= &smc_v4_hashinfo,
102 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
103 };
104 EXPORT_SYMBOL_GPL(smc_proto);
105 
106 struct proto smc_proto6 = {
107 	.name		= "SMC6",
108 	.owner		= THIS_MODULE,
109 	.keepalive	= smc_set_keepalive,
110 	.hash		= smc_hash_sk,
111 	.unhash		= smc_unhash_sk,
112 	.obj_size	= sizeof(struct smc_sock),
113 	.h.smc_hash	= &smc_v6_hashinfo,
114 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
115 };
116 EXPORT_SYMBOL_GPL(smc_proto6);
117 
118 static int smc_release(struct socket *sock)
119 {
120 	struct sock *sk = sock->sk;
121 	struct smc_sock *smc;
122 	int rc = 0;
123 
124 	if (!sk)
125 		goto out;
126 
127 	smc = smc_sk(sk);
128 
129 	/* cleanup for a dangling non-blocking connect */
130 	if (smc->connect_info && sk->sk_state == SMC_INIT)
131 		tcp_abort(smc->clcsock->sk, ECONNABORTED);
132 	flush_work(&smc->connect_work);
133 	kfree(smc->connect_info);
134 	smc->connect_info = NULL;
135 
136 	if (sk->sk_state == SMC_LISTEN)
137 		/* smc_close_non_accepted() is called and acquires
138 		 * sock lock for child sockets again
139 		 */
140 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
141 	else
142 		lock_sock(sk);
143 
144 	if (!smc->use_fallback) {
145 		rc = smc_close_active(smc);
146 		sock_set_flag(sk, SOCK_DEAD);
147 		sk->sk_shutdown |= SHUTDOWN_MASK;
148 	}
149 
150 	sk->sk_prot->unhash(sk);
151 
152 	if (smc->clcsock) {
153 		if (smc->use_fallback && sk->sk_state == SMC_LISTEN) {
154 			/* wake up clcsock accept */
155 			rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
156 		}
157 		mutex_lock(&smc->clcsock_release_lock);
158 		sock_release(smc->clcsock);
159 		smc->clcsock = NULL;
160 		mutex_unlock(&smc->clcsock_release_lock);
161 	}
162 	if (smc->use_fallback) {
163 		if (sk->sk_state != SMC_LISTEN && sk->sk_state != SMC_INIT)
164 			sock_put(sk); /* passive closing */
165 		sk->sk_state = SMC_CLOSED;
166 		sk->sk_state_change(sk);
167 	}
168 
169 	/* detach socket */
170 	sock_orphan(sk);
171 	sock->sk = NULL;
172 	if (!smc->use_fallback && sk->sk_state == SMC_CLOSED)
173 		smc_conn_free(&smc->conn);
174 	release_sock(sk);
175 
176 	sock_put(sk); /* final sock_put */
177 out:
178 	return rc;
179 }
180 
181 static void smc_destruct(struct sock *sk)
182 {
183 	if (sk->sk_state != SMC_CLOSED)
184 		return;
185 	if (!sock_flag(sk, SOCK_DEAD))
186 		return;
187 
188 	sk_refcnt_debug_dec(sk);
189 }
190 
191 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
192 				   int protocol)
193 {
194 	struct smc_sock *smc;
195 	struct proto *prot;
196 	struct sock *sk;
197 
198 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
199 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
200 	if (!sk)
201 		return NULL;
202 
203 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
204 	sk->sk_state = SMC_INIT;
205 	sk->sk_destruct = smc_destruct;
206 	sk->sk_protocol = protocol;
207 	smc = smc_sk(sk);
208 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
209 	INIT_WORK(&smc->connect_work, smc_connect_work);
210 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
211 	INIT_LIST_HEAD(&smc->accept_q);
212 	spin_lock_init(&smc->accept_q_lock);
213 	spin_lock_init(&smc->conn.send_lock);
214 	sk->sk_prot->hash(sk);
215 	sk_refcnt_debug_inc(sk);
216 	mutex_init(&smc->clcsock_release_lock);
217 
218 	return sk;
219 }
220 
221 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
222 		    int addr_len)
223 {
224 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
225 	struct sock *sk = sock->sk;
226 	struct smc_sock *smc;
227 	int rc;
228 
229 	smc = smc_sk(sk);
230 
231 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
232 	rc = -EINVAL;
233 	if (addr_len < sizeof(struct sockaddr_in))
234 		goto out;
235 
236 	rc = -EAFNOSUPPORT;
237 	if (addr->sin_family != AF_INET &&
238 	    addr->sin_family != AF_INET6 &&
239 	    addr->sin_family != AF_UNSPEC)
240 		goto out;
241 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
242 	if (addr->sin_family == AF_UNSPEC &&
243 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
244 		goto out;
245 
246 	lock_sock(sk);
247 
248 	/* Check if socket is already active */
249 	rc = -EINVAL;
250 	if (sk->sk_state != SMC_INIT)
251 		goto out_rel;
252 
253 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
254 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
255 
256 out_rel:
257 	release_sock(sk);
258 out:
259 	return rc;
260 }
261 
262 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
263 				   unsigned long mask)
264 {
265 	/* options we don't get control via setsockopt for */
266 	nsk->sk_type = osk->sk_type;
267 	nsk->sk_sndbuf = osk->sk_sndbuf;
268 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
269 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
270 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
271 	nsk->sk_mark = osk->sk_mark;
272 	nsk->sk_priority = osk->sk_priority;
273 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
274 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
275 	nsk->sk_err = osk->sk_err;
276 
277 	nsk->sk_flags &= ~mask;
278 	nsk->sk_flags |= osk->sk_flags & mask;
279 }
280 
281 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
282 			     (1UL << SOCK_KEEPOPEN) | \
283 			     (1UL << SOCK_LINGER) | \
284 			     (1UL << SOCK_BROADCAST) | \
285 			     (1UL << SOCK_TIMESTAMP) | \
286 			     (1UL << SOCK_DBG) | \
287 			     (1UL << SOCK_RCVTSTAMP) | \
288 			     (1UL << SOCK_RCVTSTAMPNS) | \
289 			     (1UL << SOCK_LOCALROUTE) | \
290 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
291 			     (1UL << SOCK_RXQ_OVFL) | \
292 			     (1UL << SOCK_WIFI_STATUS) | \
293 			     (1UL << SOCK_NOFCS) | \
294 			     (1UL << SOCK_FILTER_LOCKED))
295 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
296  * clc socket (since smc is not called for these options from net/core)
297  */
298 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
299 {
300 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
301 }
302 
303 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
304 			     (1UL << SOCK_KEEPOPEN) | \
305 			     (1UL << SOCK_LINGER) | \
306 			     (1UL << SOCK_DBG))
307 /* copy only settings and flags relevant for smc from clc to smc socket */
308 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
309 {
310 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
311 }
312 
313 /* register a new rmb, send confirm_rkey msg to register with peer */
314 static int smc_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc,
315 		       bool conf_rkey)
316 {
317 	if (!rmb_desc->wr_reg) {
318 		/* register memory region for new rmb */
319 		if (smc_wr_reg_send(link, rmb_desc->mr_rx[SMC_SINGLE_LINK])) {
320 			rmb_desc->regerr = 1;
321 			return -EFAULT;
322 		}
323 		rmb_desc->wr_reg = 1;
324 	}
325 	if (!conf_rkey)
326 		return 0;
327 	/* exchange confirm_rkey msg with peer */
328 	if (smc_llc_do_confirm_rkey(link, rmb_desc)) {
329 		rmb_desc->regerr = 1;
330 		return -EFAULT;
331 	}
332 	return 0;
333 }
334 
335 static int smc_clnt_conf_first_link(struct smc_sock *smc)
336 {
337 	struct net *net = sock_net(smc->clcsock->sk);
338 	struct smc_link_group *lgr = smc->conn.lgr;
339 	struct smc_link *link;
340 	int rest;
341 	int rc;
342 
343 	link = &lgr->lnk[SMC_SINGLE_LINK];
344 	/* receive CONFIRM LINK request from server over RoCE fabric */
345 	rest = wait_for_completion_interruptible_timeout(
346 		&link->llc_confirm,
347 		SMC_LLC_WAIT_FIRST_TIME);
348 	if (rest <= 0) {
349 		struct smc_clc_msg_decline dclc;
350 
351 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
352 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
353 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
354 	}
355 
356 	if (link->llc_confirm_rc)
357 		return SMC_CLC_DECL_RMBE_EC;
358 
359 	rc = smc_ib_modify_qp_rts(link);
360 	if (rc)
361 		return SMC_CLC_DECL_ERR_RDYLNK;
362 
363 	smc_wr_remember_qp_attr(link);
364 
365 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
366 		return SMC_CLC_DECL_ERR_REGRMB;
367 
368 	/* send CONFIRM LINK response over RoCE fabric */
369 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
370 	if (rc < 0)
371 		return SMC_CLC_DECL_TIMEOUT_CL;
372 
373 	/* receive ADD LINK request from server over RoCE fabric */
374 	rest = wait_for_completion_interruptible_timeout(&link->llc_add,
375 							 SMC_LLC_WAIT_TIME);
376 	if (rest <= 0) {
377 		struct smc_clc_msg_decline dclc;
378 
379 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
380 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
381 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_AL : rc;
382 	}
383 
384 	/* send add link reject message, only one link supported for now */
385 	rc = smc_llc_send_add_link(link,
386 				   link->smcibdev->mac[link->ibport - 1],
387 				   link->gid, SMC_LLC_RESP);
388 	if (rc < 0)
389 		return SMC_CLC_DECL_TIMEOUT_AL;
390 
391 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
392 
393 	return 0;
394 }
395 
396 static void smcr_conn_save_peer_info(struct smc_sock *smc,
397 				     struct smc_clc_msg_accept_confirm *clc)
398 {
399 	int bufsize = smc_uncompress_bufsize(clc->rmbe_size);
400 
401 	smc->conn.peer_rmbe_idx = clc->rmbe_idx;
402 	smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
403 	smc->conn.peer_rmbe_size = bufsize;
404 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
405 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
406 }
407 
408 static void smcd_conn_save_peer_info(struct smc_sock *smc,
409 				     struct smc_clc_msg_accept_confirm *clc)
410 {
411 	int bufsize = smc_uncompress_bufsize(clc->dmbe_size);
412 
413 	smc->conn.peer_rmbe_idx = clc->dmbe_idx;
414 	smc->conn.peer_token = clc->token;
415 	/* msg header takes up space in the buffer */
416 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
417 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
418 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
419 }
420 
421 static void smc_conn_save_peer_info(struct smc_sock *smc,
422 				    struct smc_clc_msg_accept_confirm *clc)
423 {
424 	if (smc->conn.lgr->is_smcd)
425 		smcd_conn_save_peer_info(smc, clc);
426 	else
427 		smcr_conn_save_peer_info(smc, clc);
428 }
429 
430 static void smc_link_save_peer_info(struct smc_link *link,
431 				    struct smc_clc_msg_accept_confirm *clc)
432 {
433 	link->peer_qpn = ntoh24(clc->qpn);
434 	memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
435 	memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
436 	link->peer_psn = ntoh24(clc->psn);
437 	link->peer_mtu = clc->qp_mtu;
438 }
439 
440 /* fall back during connect */
441 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
442 {
443 	smc->use_fallback = true;
444 	smc->fallback_rsn = reason_code;
445 	smc_copy_sock_settings_to_clc(smc);
446 	if (smc->sk.sk_state == SMC_INIT)
447 		smc->sk.sk_state = SMC_ACTIVE;
448 	return 0;
449 }
450 
451 /* decline and fall back during connect */
452 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code)
453 {
454 	int rc;
455 
456 	if (reason_code < 0) { /* error, fallback is not possible */
457 		if (smc->sk.sk_state == SMC_INIT)
458 			sock_put(&smc->sk); /* passive closing */
459 		return reason_code;
460 	}
461 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
462 		rc = smc_clc_send_decline(smc, reason_code);
463 		if (rc < 0) {
464 			if (smc->sk.sk_state == SMC_INIT)
465 				sock_put(&smc->sk); /* passive closing */
466 			return rc;
467 		}
468 	}
469 	return smc_connect_fallback(smc, reason_code);
470 }
471 
472 /* abort connecting */
473 static int smc_connect_abort(struct smc_sock *smc, int reason_code,
474 			     int local_contact)
475 {
476 	if (local_contact == SMC_FIRST_CONTACT)
477 		smc_lgr_forget(smc->conn.lgr);
478 	mutex_unlock(&smc_create_lgr_pending);
479 	smc_conn_free(&smc->conn);
480 	return reason_code;
481 }
482 
483 /* check if there is a rdma device available for this connection. */
484 /* called for connect and listen */
485 static int smc_check_rdma(struct smc_sock *smc, struct smc_ib_device **ibdev,
486 			  u8 *ibport, unsigned short vlan_id, u8 gid[])
487 {
488 	int reason_code = 0;
489 
490 	/* PNET table look up: search active ib_device and port
491 	 * within same PNETID that also contains the ethernet device
492 	 * used for the internal TCP socket
493 	 */
494 	smc_pnet_find_roce_resource(smc->clcsock->sk, ibdev, ibport, vlan_id,
495 				    gid);
496 	if (!(*ibdev))
497 		reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
498 
499 	return reason_code;
500 }
501 
502 /* check if there is an ISM device available for this connection. */
503 /* called for connect and listen */
504 static int smc_check_ism(struct smc_sock *smc, struct smcd_dev **ismdev)
505 {
506 	/* Find ISM device with same PNETID as connecting interface  */
507 	smc_pnet_find_ism_resource(smc->clcsock->sk, ismdev);
508 	if (!(*ismdev))
509 		return SMC_CLC_DECL_CNFERR; /* configuration error */
510 	return 0;
511 }
512 
513 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
514 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
515 				      struct smcd_dev *ismdev,
516 				      unsigned short vlan_id)
517 {
518 	if (vlan_id && smc_ism_get_vlan(ismdev, vlan_id))
519 		return SMC_CLC_DECL_CNFERR;
520 	return 0;
521 }
522 
523 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
524  * used, the VLAN ID will be registered again during the connection setup.
525  */
526 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc, bool is_smcd,
527 					struct smcd_dev *ismdev,
528 					unsigned short vlan_id)
529 {
530 	if (!is_smcd)
531 		return 0;
532 	if (vlan_id && smc_ism_put_vlan(ismdev, vlan_id))
533 		return SMC_CLC_DECL_CNFERR;
534 	return 0;
535 }
536 
537 /* CLC handshake during connect */
538 static int smc_connect_clc(struct smc_sock *smc, int smc_type,
539 			   struct smc_clc_msg_accept_confirm *aclc,
540 			   struct smc_ib_device *ibdev, u8 ibport,
541 			   u8 gid[], struct smcd_dev *ismdev)
542 {
543 	int rc = 0;
544 
545 	/* do inband token exchange */
546 	rc = smc_clc_send_proposal(smc, smc_type, ibdev, ibport, gid, ismdev);
547 	if (rc)
548 		return rc;
549 	/* receive SMC Accept CLC message */
550 	return smc_clc_wait_msg(smc, aclc, sizeof(*aclc), SMC_CLC_ACCEPT,
551 				CLC_WAIT_TIME);
552 }
553 
554 /* setup for RDMA connection of client */
555 static int smc_connect_rdma(struct smc_sock *smc,
556 			    struct smc_clc_msg_accept_confirm *aclc,
557 			    struct smc_ib_device *ibdev, u8 ibport)
558 {
559 	int local_contact = SMC_FIRST_CONTACT;
560 	struct smc_link *link;
561 	int reason_code = 0;
562 
563 	mutex_lock(&smc_create_lgr_pending);
564 	local_contact = smc_conn_create(smc, false, aclc->hdr.flag, ibdev,
565 					ibport, ntoh24(aclc->qpn), &aclc->lcl,
566 					NULL, 0);
567 	if (local_contact < 0) {
568 		if (local_contact == -ENOMEM)
569 			reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
570 		else if (local_contact == -ENOLINK)
571 			reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
572 		else
573 			reason_code = SMC_CLC_DECL_INTERR; /* other error */
574 		return smc_connect_abort(smc, reason_code, 0);
575 	}
576 	link = &smc->conn.lgr->lnk[SMC_SINGLE_LINK];
577 
578 	smc_conn_save_peer_info(smc, aclc);
579 
580 	/* create send buffer and rmb */
581 	if (smc_buf_create(smc, false))
582 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM, local_contact);
583 
584 	if (local_contact == SMC_FIRST_CONTACT)
585 		smc_link_save_peer_info(link, aclc);
586 
587 	if (smc_rmb_rtoken_handling(&smc->conn, aclc))
588 		return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RTOK,
589 					 local_contact);
590 
591 	smc_close_init(smc);
592 	smc_rx_init(smc);
593 
594 	if (local_contact == SMC_FIRST_CONTACT) {
595 		if (smc_ib_ready_link(link))
596 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RDYLNK,
597 						 local_contact);
598 	} else {
599 		if (smc_reg_rmb(link, smc->conn.rmb_desc, true))
600 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_REGRMB,
601 						 local_contact);
602 	}
603 	smc_rmb_sync_sg_for_device(&smc->conn);
604 
605 	reason_code = smc_clc_send_confirm(smc);
606 	if (reason_code)
607 		return smc_connect_abort(smc, reason_code, local_contact);
608 
609 	smc_tx_init(smc);
610 
611 	if (local_contact == SMC_FIRST_CONTACT) {
612 		/* QP confirmation over RoCE fabric */
613 		reason_code = smc_clnt_conf_first_link(smc);
614 		if (reason_code)
615 			return smc_connect_abort(smc, reason_code,
616 						 local_contact);
617 	}
618 	mutex_unlock(&smc_create_lgr_pending);
619 
620 	smc_copy_sock_settings_to_clc(smc);
621 	if (smc->sk.sk_state == SMC_INIT)
622 		smc->sk.sk_state = SMC_ACTIVE;
623 
624 	return 0;
625 }
626 
627 /* setup for ISM connection of client */
628 static int smc_connect_ism(struct smc_sock *smc,
629 			   struct smc_clc_msg_accept_confirm *aclc,
630 			   struct smcd_dev *ismdev)
631 {
632 	int local_contact = SMC_FIRST_CONTACT;
633 	int rc = 0;
634 
635 	mutex_lock(&smc_create_lgr_pending);
636 	local_contact = smc_conn_create(smc, true, aclc->hdr.flag, NULL, 0, 0,
637 					NULL, ismdev, aclc->gid);
638 	if (local_contact < 0)
639 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM, 0);
640 
641 	/* Create send and receive buffers */
642 	if (smc_buf_create(smc, true))
643 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM, local_contact);
644 
645 	smc_conn_save_peer_info(smc, aclc);
646 	smc_close_init(smc);
647 	smc_rx_init(smc);
648 	smc_tx_init(smc);
649 
650 	rc = smc_clc_send_confirm(smc);
651 	if (rc)
652 		return smc_connect_abort(smc, rc, local_contact);
653 	mutex_unlock(&smc_create_lgr_pending);
654 
655 	smc_copy_sock_settings_to_clc(smc);
656 	if (smc->sk.sk_state == SMC_INIT)
657 		smc->sk.sk_state = SMC_ACTIVE;
658 
659 	return 0;
660 }
661 
662 /* perform steps before actually connecting */
663 static int __smc_connect(struct smc_sock *smc)
664 {
665 	bool ism_supported = false, rdma_supported = false;
666 	struct smc_clc_msg_accept_confirm aclc;
667 	struct smc_ib_device *ibdev;
668 	struct smcd_dev *ismdev;
669 	u8 gid[SMC_GID_SIZE];
670 	unsigned short vlan;
671 	int smc_type;
672 	int rc = 0;
673 	u8 ibport;
674 
675 	sock_hold(&smc->sk); /* sock put in passive closing */
676 
677 	if (smc->use_fallback)
678 		return smc_connect_fallback(smc, smc->fallback_rsn);
679 
680 	/* if peer has not signalled SMC-capability, fall back */
681 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
682 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
683 
684 	/* IPSec connections opt out of SMC-R optimizations */
685 	if (using_ipsec(smc))
686 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC);
687 
688 	/* check for VLAN ID */
689 	if (smc_vlan_by_tcpsk(smc->clcsock, &vlan))
690 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_CNFERR);
691 
692 	/* check if there is an ism device available */
693 	if (!smc_check_ism(smc, &ismdev) &&
694 	    !smc_connect_ism_vlan_setup(smc, ismdev, vlan)) {
695 		/* ISM is supported for this connection */
696 		ism_supported = true;
697 		smc_type = SMC_TYPE_D;
698 	}
699 
700 	/* check if there is a rdma device available */
701 	if (!smc_check_rdma(smc, &ibdev, &ibport, vlan, gid)) {
702 		/* RDMA is supported for this connection */
703 		rdma_supported = true;
704 		if (ism_supported)
705 			smc_type = SMC_TYPE_B; /* both */
706 		else
707 			smc_type = SMC_TYPE_R; /* only RDMA */
708 	}
709 
710 	/* if neither ISM nor RDMA are supported, fallback */
711 	if (!rdma_supported && !ism_supported)
712 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_NOSMCDEV);
713 
714 	/* perform CLC handshake */
715 	rc = smc_connect_clc(smc, smc_type, &aclc, ibdev, ibport, gid, ismdev);
716 	if (rc) {
717 		smc_connect_ism_vlan_cleanup(smc, ism_supported, ismdev, vlan);
718 		return smc_connect_decline_fallback(smc, rc);
719 	}
720 
721 	/* depending on previous steps, connect using rdma or ism */
722 	if (rdma_supported && aclc.hdr.path == SMC_TYPE_R)
723 		rc = smc_connect_rdma(smc, &aclc, ibdev, ibport);
724 	else if (ism_supported && aclc.hdr.path == SMC_TYPE_D)
725 		rc = smc_connect_ism(smc, &aclc, ismdev);
726 	else
727 		rc = SMC_CLC_DECL_MODEUNSUPP;
728 	if (rc) {
729 		smc_connect_ism_vlan_cleanup(smc, ism_supported, ismdev, vlan);
730 		return smc_connect_decline_fallback(smc, rc);
731 	}
732 
733 	smc_connect_ism_vlan_cleanup(smc, ism_supported, ismdev, vlan);
734 	return 0;
735 }
736 
737 static void smc_connect_work(struct work_struct *work)
738 {
739 	struct smc_sock *smc = container_of(work, struct smc_sock,
740 					    connect_work);
741 	int rc;
742 
743 	lock_sock(&smc->sk);
744 	rc = kernel_connect(smc->clcsock, &smc->connect_info->addr,
745 			    smc->connect_info->alen, smc->connect_info->flags);
746 	if (smc->clcsock->sk->sk_err) {
747 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
748 		goto out;
749 	}
750 	if (rc < 0) {
751 		smc->sk.sk_err = -rc;
752 		goto out;
753 	}
754 
755 	rc = __smc_connect(smc);
756 	if (rc < 0)
757 		smc->sk.sk_err = -rc;
758 
759 out:
760 	if (smc->sk.sk_err)
761 		smc->sk.sk_state_change(&smc->sk);
762 	else
763 		smc->sk.sk_write_space(&smc->sk);
764 	kfree(smc->connect_info);
765 	smc->connect_info = NULL;
766 	release_sock(&smc->sk);
767 }
768 
769 static int smc_connect(struct socket *sock, struct sockaddr *addr,
770 		       int alen, int flags)
771 {
772 	struct sock *sk = sock->sk;
773 	struct smc_sock *smc;
774 	int rc = -EINVAL;
775 
776 	smc = smc_sk(sk);
777 
778 	/* separate smc parameter checking to be safe */
779 	if (alen < sizeof(addr->sa_family))
780 		goto out_err;
781 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
782 		goto out_err;
783 
784 	lock_sock(sk);
785 	switch (sk->sk_state) {
786 	default:
787 		goto out;
788 	case SMC_ACTIVE:
789 		rc = -EISCONN;
790 		goto out;
791 	case SMC_INIT:
792 		rc = 0;
793 		break;
794 	}
795 
796 	smc_copy_sock_settings_to_clc(smc);
797 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
798 	if (flags & O_NONBLOCK) {
799 		if (smc->connect_info) {
800 			rc = -EALREADY;
801 			goto out;
802 		}
803 		smc->connect_info = kzalloc(alen + 2 * sizeof(int), GFP_KERNEL);
804 		if (!smc->connect_info) {
805 			rc = -ENOMEM;
806 			goto out;
807 		}
808 		smc->connect_info->alen = alen;
809 		smc->connect_info->flags = flags ^ O_NONBLOCK;
810 		memcpy(&smc->connect_info->addr, addr, alen);
811 		schedule_work(&smc->connect_work);
812 		rc = -EINPROGRESS;
813 	} else {
814 		rc = kernel_connect(smc->clcsock, addr, alen, flags);
815 		if (rc)
816 			goto out;
817 
818 		rc = __smc_connect(smc);
819 		if (rc < 0)
820 			goto out;
821 		else
822 			rc = 0; /* success cases including fallback */
823 	}
824 
825 out:
826 	release_sock(sk);
827 out_err:
828 	return rc;
829 }
830 
831 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
832 {
833 	struct socket *new_clcsock = NULL;
834 	struct sock *lsk = &lsmc->sk;
835 	struct sock *new_sk;
836 	int rc = -EINVAL;
837 
838 	release_sock(lsk);
839 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
840 	if (!new_sk) {
841 		rc = -ENOMEM;
842 		lsk->sk_err = ENOMEM;
843 		*new_smc = NULL;
844 		lock_sock(lsk);
845 		goto out;
846 	}
847 	*new_smc = smc_sk(new_sk);
848 
849 	mutex_lock(&lsmc->clcsock_release_lock);
850 	if (lsmc->clcsock)
851 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
852 	mutex_unlock(&lsmc->clcsock_release_lock);
853 	lock_sock(lsk);
854 	if  (rc < 0)
855 		lsk->sk_err = -rc;
856 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
857 		if (new_clcsock)
858 			sock_release(new_clcsock);
859 		new_sk->sk_state = SMC_CLOSED;
860 		sock_set_flag(new_sk, SOCK_DEAD);
861 		new_sk->sk_prot->unhash(new_sk);
862 		sock_put(new_sk); /* final */
863 		*new_smc = NULL;
864 		goto out;
865 	}
866 
867 	(*new_smc)->clcsock = new_clcsock;
868 out:
869 	return rc;
870 }
871 
872 /* add a just created sock to the accept queue of the listen sock as
873  * candidate for a following socket accept call from user space
874  */
875 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
876 {
877 	struct smc_sock *par = smc_sk(parent);
878 
879 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
880 	spin_lock(&par->accept_q_lock);
881 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
882 	spin_unlock(&par->accept_q_lock);
883 	sk_acceptq_added(parent);
884 }
885 
886 /* remove a socket from the accept queue of its parental listening socket */
887 static void smc_accept_unlink(struct sock *sk)
888 {
889 	struct smc_sock *par = smc_sk(sk)->listen_smc;
890 
891 	spin_lock(&par->accept_q_lock);
892 	list_del_init(&smc_sk(sk)->accept_q);
893 	spin_unlock(&par->accept_q_lock);
894 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
895 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
896 }
897 
898 /* remove a sock from the accept queue to bind it to a new socket created
899  * for a socket accept call from user space
900  */
901 struct sock *smc_accept_dequeue(struct sock *parent,
902 				struct socket *new_sock)
903 {
904 	struct smc_sock *isk, *n;
905 	struct sock *new_sk;
906 
907 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
908 		new_sk = (struct sock *)isk;
909 
910 		smc_accept_unlink(new_sk);
911 		if (new_sk->sk_state == SMC_CLOSED) {
912 			if (isk->clcsock) {
913 				sock_release(isk->clcsock);
914 				isk->clcsock = NULL;
915 			}
916 			new_sk->sk_prot->unhash(new_sk);
917 			sock_put(new_sk); /* final */
918 			continue;
919 		}
920 		if (new_sock)
921 			sock_graft(new_sk, new_sock);
922 		return new_sk;
923 	}
924 	return NULL;
925 }
926 
927 /* clean up for a created but never accepted sock */
928 void smc_close_non_accepted(struct sock *sk)
929 {
930 	struct smc_sock *smc = smc_sk(sk);
931 
932 	lock_sock(sk);
933 	if (!sk->sk_lingertime)
934 		/* wait for peer closing */
935 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
936 	if (!smc->use_fallback) {
937 		smc_close_active(smc);
938 		sock_set_flag(sk, SOCK_DEAD);
939 		sk->sk_shutdown |= SHUTDOWN_MASK;
940 	}
941 	if (smc->clcsock) {
942 		struct socket *tcp;
943 
944 		tcp = smc->clcsock;
945 		smc->clcsock = NULL;
946 		sock_release(tcp);
947 	}
948 	if (smc->use_fallback) {
949 		sock_put(sk); /* passive closing */
950 		sk->sk_state = SMC_CLOSED;
951 	} else {
952 		if (sk->sk_state == SMC_CLOSED)
953 			smc_conn_free(&smc->conn);
954 	}
955 	release_sock(sk);
956 	sk->sk_prot->unhash(sk);
957 	sock_put(sk); /* final sock_put */
958 }
959 
960 static int smc_serv_conf_first_link(struct smc_sock *smc)
961 {
962 	struct net *net = sock_net(smc->clcsock->sk);
963 	struct smc_link_group *lgr = smc->conn.lgr;
964 	struct smc_link *link;
965 	int rest;
966 	int rc;
967 
968 	link = &lgr->lnk[SMC_SINGLE_LINK];
969 
970 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
971 		return SMC_CLC_DECL_ERR_REGRMB;
972 
973 	/* send CONFIRM LINK request to client over the RoCE fabric */
974 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
975 	if (rc < 0)
976 		return SMC_CLC_DECL_TIMEOUT_CL;
977 
978 	/* receive CONFIRM LINK response from client over the RoCE fabric */
979 	rest = wait_for_completion_interruptible_timeout(
980 		&link->llc_confirm_resp,
981 		SMC_LLC_WAIT_FIRST_TIME);
982 	if (rest <= 0) {
983 		struct smc_clc_msg_decline dclc;
984 
985 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
986 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
987 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
988 	}
989 
990 	if (link->llc_confirm_resp_rc)
991 		return SMC_CLC_DECL_RMBE_EC;
992 
993 	/* send ADD LINK request to client over the RoCE fabric */
994 	rc = smc_llc_send_add_link(link,
995 				   link->smcibdev->mac[link->ibport - 1],
996 				   link->gid, SMC_LLC_REQ);
997 	if (rc < 0)
998 		return SMC_CLC_DECL_TIMEOUT_AL;
999 
1000 	/* receive ADD LINK response from client over the RoCE fabric */
1001 	rest = wait_for_completion_interruptible_timeout(&link->llc_add_resp,
1002 							 SMC_LLC_WAIT_TIME);
1003 	if (rest <= 0) {
1004 		struct smc_clc_msg_decline dclc;
1005 
1006 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1007 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1008 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_AL : rc;
1009 	}
1010 
1011 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
1012 
1013 	return 0;
1014 }
1015 
1016 /* listen worker: finish */
1017 static void smc_listen_out(struct smc_sock *new_smc)
1018 {
1019 	struct smc_sock *lsmc = new_smc->listen_smc;
1020 	struct sock *newsmcsk = &new_smc->sk;
1021 
1022 	lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1023 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1024 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1025 	} else { /* no longer listening */
1026 		smc_close_non_accepted(newsmcsk);
1027 	}
1028 	release_sock(&lsmc->sk);
1029 
1030 	/* Wake up accept */
1031 	lsmc->sk.sk_data_ready(&lsmc->sk);
1032 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1033 }
1034 
1035 /* listen worker: finish in state connected */
1036 static void smc_listen_out_connected(struct smc_sock *new_smc)
1037 {
1038 	struct sock *newsmcsk = &new_smc->sk;
1039 
1040 	sk_refcnt_debug_inc(newsmcsk);
1041 	if (newsmcsk->sk_state == SMC_INIT)
1042 		newsmcsk->sk_state = SMC_ACTIVE;
1043 
1044 	smc_listen_out(new_smc);
1045 }
1046 
1047 /* listen worker: finish in error state */
1048 static void smc_listen_out_err(struct smc_sock *new_smc)
1049 {
1050 	struct sock *newsmcsk = &new_smc->sk;
1051 
1052 	if (newsmcsk->sk_state == SMC_INIT)
1053 		sock_put(&new_smc->sk); /* passive closing */
1054 	newsmcsk->sk_state = SMC_CLOSED;
1055 	smc_conn_free(&new_smc->conn);
1056 
1057 	smc_listen_out(new_smc);
1058 }
1059 
1060 /* listen worker: decline and fall back if possible */
1061 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1062 			       int local_contact)
1063 {
1064 	/* RDMA setup failed, switch back to TCP */
1065 	if (local_contact == SMC_FIRST_CONTACT)
1066 		smc_lgr_forget(new_smc->conn.lgr);
1067 	if (reason_code < 0) { /* error, no fallback possible */
1068 		smc_listen_out_err(new_smc);
1069 		return;
1070 	}
1071 	smc_conn_free(&new_smc->conn);
1072 	new_smc->use_fallback = true;
1073 	new_smc->fallback_rsn = reason_code;
1074 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1075 		if (smc_clc_send_decline(new_smc, reason_code) < 0) {
1076 			smc_listen_out_err(new_smc);
1077 			return;
1078 		}
1079 	}
1080 	smc_listen_out_connected(new_smc);
1081 }
1082 
1083 /* listen worker: check prefixes */
1084 static int smc_listen_rdma_check(struct smc_sock *new_smc,
1085 				 struct smc_clc_msg_proposal *pclc)
1086 {
1087 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1088 	struct socket *newclcsock = new_smc->clcsock;
1089 
1090 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1091 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1092 		return SMC_CLC_DECL_CNFERR;
1093 
1094 	return 0;
1095 }
1096 
1097 /* listen worker: initialize connection and buffers */
1098 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1099 				struct smc_clc_msg_proposal *pclc,
1100 				struct smc_ib_device *ibdev, u8 ibport,
1101 				int *local_contact)
1102 {
1103 	/* allocate connection / link group */
1104 	*local_contact = smc_conn_create(new_smc, false, 0, ibdev, ibport, 0,
1105 					 &pclc->lcl, NULL, 0);
1106 	if (*local_contact < 0) {
1107 		if (*local_contact == -ENOMEM)
1108 			return SMC_CLC_DECL_MEM;/* insufficient memory*/
1109 		return SMC_CLC_DECL_INTERR; /* other error */
1110 	}
1111 
1112 	/* create send buffer and rmb */
1113 	if (smc_buf_create(new_smc, false))
1114 		return SMC_CLC_DECL_MEM;
1115 
1116 	return 0;
1117 }
1118 
1119 /* listen worker: initialize connection and buffers for SMC-D */
1120 static int smc_listen_ism_init(struct smc_sock *new_smc,
1121 			       struct smc_clc_msg_proposal *pclc,
1122 			       struct smcd_dev *ismdev,
1123 			       int *local_contact)
1124 {
1125 	struct smc_clc_msg_smcd *pclc_smcd;
1126 
1127 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
1128 	*local_contact = smc_conn_create(new_smc, true, 0, NULL, 0, 0, NULL,
1129 					 ismdev, pclc_smcd->gid);
1130 	if (*local_contact < 0) {
1131 		if (*local_contact == -ENOMEM)
1132 			return SMC_CLC_DECL_MEM;/* insufficient memory*/
1133 		return SMC_CLC_DECL_INTERR; /* other error */
1134 	}
1135 
1136 	/* Check if peer can be reached via ISM device */
1137 	if (smc_ism_cantalk(new_smc->conn.lgr->peer_gid,
1138 			    new_smc->conn.lgr->vlan_id,
1139 			    new_smc->conn.lgr->smcd)) {
1140 		if (*local_contact == SMC_FIRST_CONTACT)
1141 			smc_lgr_forget(new_smc->conn.lgr);
1142 		smc_conn_free(&new_smc->conn);
1143 		return SMC_CLC_DECL_CNFERR;
1144 	}
1145 
1146 	/* Create send and receive buffers */
1147 	if (smc_buf_create(new_smc, true)) {
1148 		if (*local_contact == SMC_FIRST_CONTACT)
1149 			smc_lgr_forget(new_smc->conn.lgr);
1150 		smc_conn_free(&new_smc->conn);
1151 		return SMC_CLC_DECL_MEM;
1152 	}
1153 
1154 	return 0;
1155 }
1156 
1157 /* listen worker: register buffers */
1158 static int smc_listen_rdma_reg(struct smc_sock *new_smc, int local_contact)
1159 {
1160 	struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
1161 
1162 	if (local_contact != SMC_FIRST_CONTACT) {
1163 		if (smc_reg_rmb(link, new_smc->conn.rmb_desc, true))
1164 			return SMC_CLC_DECL_ERR_REGRMB;
1165 	}
1166 	smc_rmb_sync_sg_for_device(&new_smc->conn);
1167 
1168 	return 0;
1169 }
1170 
1171 /* listen worker: finish RDMA setup */
1172 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
1173 				  struct smc_clc_msg_accept_confirm *cclc,
1174 				  int local_contact)
1175 {
1176 	struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
1177 	int reason_code = 0;
1178 
1179 	if (local_contact == SMC_FIRST_CONTACT)
1180 		smc_link_save_peer_info(link, cclc);
1181 
1182 	if (smc_rmb_rtoken_handling(&new_smc->conn, cclc)) {
1183 		reason_code = SMC_CLC_DECL_ERR_RTOK;
1184 		goto decline;
1185 	}
1186 
1187 	if (local_contact == SMC_FIRST_CONTACT) {
1188 		if (smc_ib_ready_link(link)) {
1189 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
1190 			goto decline;
1191 		}
1192 		/* QP confirmation over RoCE fabric */
1193 		reason_code = smc_serv_conf_first_link(new_smc);
1194 		if (reason_code)
1195 			goto decline;
1196 	}
1197 	return 0;
1198 
1199 decline:
1200 	smc_listen_decline(new_smc, reason_code, local_contact);
1201 	return reason_code;
1202 }
1203 
1204 /* setup for RDMA connection of server */
1205 static void smc_listen_work(struct work_struct *work)
1206 {
1207 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
1208 						smc_listen_work);
1209 	struct socket *newclcsock = new_smc->clcsock;
1210 	struct smc_clc_msg_accept_confirm cclc;
1211 	struct smc_clc_msg_proposal *pclc;
1212 	struct smc_ib_device *ibdev;
1213 	bool ism_supported = false;
1214 	struct smcd_dev *ismdev;
1215 	u8 buf[SMC_CLC_MAX_LEN];
1216 	int local_contact = 0;
1217 	unsigned short vlan;
1218 	int reason_code = 0;
1219 	int rc = 0;
1220 	u8 ibport;
1221 
1222 	if (new_smc->use_fallback) {
1223 		smc_listen_out_connected(new_smc);
1224 		return;
1225 	}
1226 
1227 	/* check if peer is smc capable */
1228 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
1229 		new_smc->use_fallback = true;
1230 		new_smc->fallback_rsn = SMC_CLC_DECL_PEERNOSMC;
1231 		smc_listen_out_connected(new_smc);
1232 		return;
1233 	}
1234 
1235 	/* do inband token exchange -
1236 	 * wait for and receive SMC Proposal CLC message
1237 	 */
1238 	pclc = (struct smc_clc_msg_proposal *)&buf;
1239 	reason_code = smc_clc_wait_msg(new_smc, pclc, SMC_CLC_MAX_LEN,
1240 				       SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
1241 	if (reason_code) {
1242 		smc_listen_decline(new_smc, reason_code, 0);
1243 		return;
1244 	}
1245 
1246 	/* IPSec connections opt out of SMC-R optimizations */
1247 	if (using_ipsec(new_smc)) {
1248 		smc_listen_decline(new_smc, SMC_CLC_DECL_IPSEC, 0);
1249 		return;
1250 	}
1251 
1252 	mutex_lock(&smc_create_lgr_pending);
1253 	smc_close_init(new_smc);
1254 	smc_rx_init(new_smc);
1255 	smc_tx_init(new_smc);
1256 
1257 	/* check if ISM is available */
1258 	if ((pclc->hdr.path == SMC_TYPE_D || pclc->hdr.path == SMC_TYPE_B) &&
1259 	    !smc_check_ism(new_smc, &ismdev) &&
1260 	    !smc_listen_ism_init(new_smc, pclc, ismdev, &local_contact)) {
1261 		ism_supported = true;
1262 	}
1263 
1264 	/* check if RDMA is available */
1265 	if (!ism_supported &&
1266 	    ((pclc->hdr.path != SMC_TYPE_R && pclc->hdr.path != SMC_TYPE_B) ||
1267 	     smc_vlan_by_tcpsk(new_smc->clcsock, &vlan) ||
1268 	     smc_check_rdma(new_smc, &ibdev, &ibport, vlan, NULL) ||
1269 	     smc_listen_rdma_check(new_smc, pclc) ||
1270 	     smc_listen_rdma_init(new_smc, pclc, ibdev, ibport,
1271 				  &local_contact) ||
1272 	     smc_listen_rdma_reg(new_smc, local_contact))) {
1273 		/* SMC not supported, decline */
1274 		mutex_unlock(&smc_create_lgr_pending);
1275 		smc_listen_decline(new_smc, SMC_CLC_DECL_MODEUNSUPP,
1276 				   local_contact);
1277 		return;
1278 	}
1279 
1280 	/* send SMC Accept CLC message */
1281 	rc = smc_clc_send_accept(new_smc, local_contact);
1282 	if (rc) {
1283 		mutex_unlock(&smc_create_lgr_pending);
1284 		smc_listen_decline(new_smc, rc, local_contact);
1285 		return;
1286 	}
1287 
1288 	/* receive SMC Confirm CLC message */
1289 	reason_code = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
1290 				       SMC_CLC_CONFIRM, CLC_WAIT_TIME);
1291 	if (reason_code) {
1292 		mutex_unlock(&smc_create_lgr_pending);
1293 		smc_listen_decline(new_smc, reason_code, local_contact);
1294 		return;
1295 	}
1296 
1297 	/* finish worker */
1298 	if (!ism_supported) {
1299 		if (smc_listen_rdma_finish(new_smc, &cclc, local_contact)) {
1300 			mutex_unlock(&smc_create_lgr_pending);
1301 			return;
1302 		}
1303 	}
1304 	smc_conn_save_peer_info(new_smc, &cclc);
1305 	mutex_unlock(&smc_create_lgr_pending);
1306 	smc_listen_out_connected(new_smc);
1307 }
1308 
1309 static void smc_tcp_listen_work(struct work_struct *work)
1310 {
1311 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
1312 					     tcp_listen_work);
1313 	struct sock *lsk = &lsmc->sk;
1314 	struct smc_sock *new_smc;
1315 	int rc = 0;
1316 
1317 	lock_sock(lsk);
1318 	while (lsk->sk_state == SMC_LISTEN) {
1319 		rc = smc_clcsock_accept(lsmc, &new_smc);
1320 		if (rc)
1321 			goto out;
1322 		if (!new_smc)
1323 			continue;
1324 
1325 		new_smc->listen_smc = lsmc;
1326 		new_smc->use_fallback = lsmc->use_fallback;
1327 		new_smc->fallback_rsn = lsmc->fallback_rsn;
1328 		sock_hold(lsk); /* sock_put in smc_listen_work */
1329 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
1330 		smc_copy_sock_settings_to_smc(new_smc);
1331 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
1332 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
1333 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
1334 		if (!schedule_work(&new_smc->smc_listen_work))
1335 			sock_put(&new_smc->sk);
1336 	}
1337 
1338 out:
1339 	release_sock(lsk);
1340 	sock_put(&lsmc->sk); /* sock_hold in smc_listen */
1341 }
1342 
1343 static int smc_listen(struct socket *sock, int backlog)
1344 {
1345 	struct sock *sk = sock->sk;
1346 	struct smc_sock *smc;
1347 	int rc;
1348 
1349 	smc = smc_sk(sk);
1350 	lock_sock(sk);
1351 
1352 	rc = -EINVAL;
1353 	if ((sk->sk_state != SMC_INIT) && (sk->sk_state != SMC_LISTEN))
1354 		goto out;
1355 
1356 	rc = 0;
1357 	if (sk->sk_state == SMC_LISTEN) {
1358 		sk->sk_max_ack_backlog = backlog;
1359 		goto out;
1360 	}
1361 	/* some socket options are handled in core, so we could not apply
1362 	 * them to the clc socket -- copy smc socket options to clc socket
1363 	 */
1364 	smc_copy_sock_settings_to_clc(smc);
1365 	if (!smc->use_fallback)
1366 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1367 
1368 	rc = kernel_listen(smc->clcsock, backlog);
1369 	if (rc)
1370 		goto out;
1371 	sk->sk_max_ack_backlog = backlog;
1372 	sk->sk_ack_backlog = 0;
1373 	sk->sk_state = SMC_LISTEN;
1374 	sock_hold(sk); /* sock_hold in tcp_listen_worker */
1375 	if (!schedule_work(&smc->tcp_listen_work))
1376 		sock_put(sk);
1377 
1378 out:
1379 	release_sock(sk);
1380 	return rc;
1381 }
1382 
1383 static int smc_accept(struct socket *sock, struct socket *new_sock,
1384 		      int flags, bool kern)
1385 {
1386 	struct sock *sk = sock->sk, *nsk;
1387 	DECLARE_WAITQUEUE(wait, current);
1388 	struct smc_sock *lsmc;
1389 	long timeo;
1390 	int rc = 0;
1391 
1392 	lsmc = smc_sk(sk);
1393 	sock_hold(sk); /* sock_put below */
1394 	lock_sock(sk);
1395 
1396 	if (lsmc->sk.sk_state != SMC_LISTEN) {
1397 		rc = -EINVAL;
1398 		release_sock(sk);
1399 		goto out;
1400 	}
1401 
1402 	/* Wait for an incoming connection */
1403 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1404 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
1405 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1406 		set_current_state(TASK_INTERRUPTIBLE);
1407 		if (!timeo) {
1408 			rc = -EAGAIN;
1409 			break;
1410 		}
1411 		release_sock(sk);
1412 		timeo = schedule_timeout(timeo);
1413 		/* wakeup by sk_data_ready in smc_listen_work() */
1414 		sched_annotate_sleep();
1415 		lock_sock(sk);
1416 		if (signal_pending(current)) {
1417 			rc = sock_intr_errno(timeo);
1418 			break;
1419 		}
1420 	}
1421 	set_current_state(TASK_RUNNING);
1422 	remove_wait_queue(sk_sleep(sk), &wait);
1423 
1424 	if (!rc)
1425 		rc = sock_error(nsk);
1426 	release_sock(sk);
1427 	if (rc)
1428 		goto out;
1429 
1430 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
1431 		/* wait till data arrives on the socket */
1432 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
1433 								MSEC_PER_SEC);
1434 		if (smc_sk(nsk)->use_fallback) {
1435 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
1436 
1437 			lock_sock(clcsk);
1438 			if (skb_queue_empty(&clcsk->sk_receive_queue))
1439 				sk_wait_data(clcsk, &timeo, NULL);
1440 			release_sock(clcsk);
1441 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
1442 			lock_sock(nsk);
1443 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
1444 			release_sock(nsk);
1445 		}
1446 	}
1447 
1448 out:
1449 	sock_put(sk); /* sock_hold above */
1450 	return rc;
1451 }
1452 
1453 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1454 		       int peer)
1455 {
1456 	struct smc_sock *smc;
1457 
1458 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
1459 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
1460 		return -ENOTCONN;
1461 
1462 	smc = smc_sk(sock->sk);
1463 
1464 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
1465 }
1466 
1467 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1468 {
1469 	struct sock *sk = sock->sk;
1470 	struct smc_sock *smc;
1471 	int rc = -EPIPE;
1472 
1473 	smc = smc_sk(sk);
1474 	lock_sock(sk);
1475 	if ((sk->sk_state != SMC_ACTIVE) &&
1476 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1477 	    (sk->sk_state != SMC_INIT))
1478 		goto out;
1479 
1480 	if (msg->msg_flags & MSG_FASTOPEN) {
1481 		if (sk->sk_state == SMC_INIT) {
1482 			smc->use_fallback = true;
1483 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1484 		} else {
1485 			rc = -EINVAL;
1486 			goto out;
1487 		}
1488 	}
1489 
1490 	if (smc->use_fallback)
1491 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
1492 	else
1493 		rc = smc_tx_sendmsg(smc, msg, len);
1494 out:
1495 	release_sock(sk);
1496 	return rc;
1497 }
1498 
1499 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1500 		       int flags)
1501 {
1502 	struct sock *sk = sock->sk;
1503 	struct smc_sock *smc;
1504 	int rc = -ENOTCONN;
1505 
1506 	smc = smc_sk(sk);
1507 	lock_sock(sk);
1508 	if ((sk->sk_state == SMC_INIT) ||
1509 	    (sk->sk_state == SMC_LISTEN) ||
1510 	    (sk->sk_state == SMC_CLOSED))
1511 		goto out;
1512 
1513 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1514 		rc = 0;
1515 		goto out;
1516 	}
1517 
1518 	if (smc->use_fallback) {
1519 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
1520 	} else {
1521 		msg->msg_namelen = 0;
1522 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
1523 	}
1524 
1525 out:
1526 	release_sock(sk);
1527 	return rc;
1528 }
1529 
1530 static __poll_t smc_accept_poll(struct sock *parent)
1531 {
1532 	struct smc_sock *isk = smc_sk(parent);
1533 	__poll_t mask = 0;
1534 
1535 	spin_lock(&isk->accept_q_lock);
1536 	if (!list_empty(&isk->accept_q))
1537 		mask = EPOLLIN | EPOLLRDNORM;
1538 	spin_unlock(&isk->accept_q_lock);
1539 
1540 	return mask;
1541 }
1542 
1543 static __poll_t smc_poll(struct file *file, struct socket *sock,
1544 			     poll_table *wait)
1545 {
1546 	struct sock *sk = sock->sk;
1547 	__poll_t mask = 0;
1548 	struct smc_sock *smc;
1549 
1550 	if (!sk)
1551 		return EPOLLNVAL;
1552 
1553 	smc = smc_sk(sock->sk);
1554 	if (smc->use_fallback) {
1555 		/* delegate to CLC child sock */
1556 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
1557 		sk->sk_err = smc->clcsock->sk->sk_err;
1558 		if (sk->sk_err)
1559 			mask |= EPOLLERR;
1560 	} else {
1561 		if (sk->sk_state != SMC_CLOSED)
1562 			sock_poll_wait(file, sock, wait);
1563 		if (sk->sk_err)
1564 			mask |= EPOLLERR;
1565 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1566 		    (sk->sk_state == SMC_CLOSED))
1567 			mask |= EPOLLHUP;
1568 		if (sk->sk_state == SMC_LISTEN) {
1569 			/* woken up by sk_data_ready in smc_listen_work() */
1570 			mask = smc_accept_poll(sk);
1571 		} else {
1572 			if (atomic_read(&smc->conn.sndbuf_space) ||
1573 			    sk->sk_shutdown & SEND_SHUTDOWN) {
1574 				mask |= EPOLLOUT | EPOLLWRNORM;
1575 			} else {
1576 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1577 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1578 			}
1579 			if (atomic_read(&smc->conn.bytes_to_rcv))
1580 				mask |= EPOLLIN | EPOLLRDNORM;
1581 			if (sk->sk_shutdown & RCV_SHUTDOWN)
1582 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
1583 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
1584 				mask |= EPOLLIN;
1585 			if (smc->conn.urg_state == SMC_URG_VALID)
1586 				mask |= EPOLLPRI;
1587 		}
1588 	}
1589 
1590 	return mask;
1591 }
1592 
1593 static int smc_shutdown(struct socket *sock, int how)
1594 {
1595 	struct sock *sk = sock->sk;
1596 	struct smc_sock *smc;
1597 	int rc = -EINVAL;
1598 	int rc1 = 0;
1599 
1600 	smc = smc_sk(sk);
1601 
1602 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
1603 		return rc;
1604 
1605 	lock_sock(sk);
1606 
1607 	rc = -ENOTCONN;
1608 	if ((sk->sk_state != SMC_ACTIVE) &&
1609 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
1610 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
1611 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1612 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
1613 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
1614 		goto out;
1615 	if (smc->use_fallback) {
1616 		rc = kernel_sock_shutdown(smc->clcsock, how);
1617 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
1618 		if (sk->sk_shutdown == SHUTDOWN_MASK)
1619 			sk->sk_state = SMC_CLOSED;
1620 		goto out;
1621 	}
1622 	switch (how) {
1623 	case SHUT_RDWR:		/* shutdown in both directions */
1624 		rc = smc_close_active(smc);
1625 		break;
1626 	case SHUT_WR:
1627 		rc = smc_close_shutdown_write(smc);
1628 		break;
1629 	case SHUT_RD:
1630 		rc = 0;
1631 		/* nothing more to do because peer is not involved */
1632 		break;
1633 	}
1634 	if (smc->clcsock)
1635 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
1636 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
1637 	sk->sk_shutdown |= how + 1;
1638 
1639 out:
1640 	release_sock(sk);
1641 	return rc ? rc : rc1;
1642 }
1643 
1644 static int smc_setsockopt(struct socket *sock, int level, int optname,
1645 			  char __user *optval, unsigned int optlen)
1646 {
1647 	struct sock *sk = sock->sk;
1648 	struct smc_sock *smc;
1649 	int val, rc;
1650 
1651 	smc = smc_sk(sk);
1652 
1653 	/* generic setsockopts reaching us here always apply to the
1654 	 * CLC socket
1655 	 */
1656 	rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
1657 					   optval, optlen);
1658 	if (smc->clcsock->sk->sk_err) {
1659 		sk->sk_err = smc->clcsock->sk->sk_err;
1660 		sk->sk_error_report(sk);
1661 	}
1662 	if (rc)
1663 		return rc;
1664 
1665 	if (optlen < sizeof(int))
1666 		return -EINVAL;
1667 	if (get_user(val, (int __user *)optval))
1668 		return -EFAULT;
1669 
1670 	lock_sock(sk);
1671 	switch (optname) {
1672 	case TCP_ULP:
1673 	case TCP_FASTOPEN:
1674 	case TCP_FASTOPEN_CONNECT:
1675 	case TCP_FASTOPEN_KEY:
1676 	case TCP_FASTOPEN_NO_COOKIE:
1677 		/* option not supported by SMC */
1678 		if (sk->sk_state == SMC_INIT) {
1679 			smc->use_fallback = true;
1680 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1681 		} else {
1682 			if (!smc->use_fallback)
1683 				rc = -EINVAL;
1684 		}
1685 		break;
1686 	case TCP_NODELAY:
1687 		if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1688 			if (val && !smc->use_fallback)
1689 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1690 						 0);
1691 		}
1692 		break;
1693 	case TCP_CORK:
1694 		if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1695 			if (!val && !smc->use_fallback)
1696 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1697 						 0);
1698 		}
1699 		break;
1700 	case TCP_DEFER_ACCEPT:
1701 		smc->sockopt_defer_accept = val;
1702 		break;
1703 	default:
1704 		break;
1705 	}
1706 	release_sock(sk);
1707 
1708 	return rc;
1709 }
1710 
1711 static int smc_getsockopt(struct socket *sock, int level, int optname,
1712 			  char __user *optval, int __user *optlen)
1713 {
1714 	struct smc_sock *smc;
1715 
1716 	smc = smc_sk(sock->sk);
1717 	/* socket options apply to the CLC socket */
1718 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
1719 					     optval, optlen);
1720 }
1721 
1722 static int smc_ioctl(struct socket *sock, unsigned int cmd,
1723 		     unsigned long arg)
1724 {
1725 	union smc_host_cursor cons, urg;
1726 	struct smc_connection *conn;
1727 	struct smc_sock *smc;
1728 	int answ;
1729 
1730 	smc = smc_sk(sock->sk);
1731 	conn = &smc->conn;
1732 	lock_sock(&smc->sk);
1733 	if (smc->use_fallback) {
1734 		if (!smc->clcsock) {
1735 			release_sock(&smc->sk);
1736 			return -EBADF;
1737 		}
1738 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
1739 		release_sock(&smc->sk);
1740 		return answ;
1741 	}
1742 	switch (cmd) {
1743 	case SIOCINQ: /* same as FIONREAD */
1744 		if (smc->sk.sk_state == SMC_LISTEN) {
1745 			release_sock(&smc->sk);
1746 			return -EINVAL;
1747 		}
1748 		if (smc->sk.sk_state == SMC_INIT ||
1749 		    smc->sk.sk_state == SMC_CLOSED)
1750 			answ = 0;
1751 		else
1752 			answ = atomic_read(&smc->conn.bytes_to_rcv);
1753 		break;
1754 	case SIOCOUTQ:
1755 		/* output queue size (not send + not acked) */
1756 		if (smc->sk.sk_state == SMC_LISTEN) {
1757 			release_sock(&smc->sk);
1758 			return -EINVAL;
1759 		}
1760 		if (smc->sk.sk_state == SMC_INIT ||
1761 		    smc->sk.sk_state == SMC_CLOSED)
1762 			answ = 0;
1763 		else
1764 			answ = smc->conn.sndbuf_desc->len -
1765 					atomic_read(&smc->conn.sndbuf_space);
1766 		break;
1767 	case SIOCOUTQNSD:
1768 		/* output queue size (not send only) */
1769 		if (smc->sk.sk_state == SMC_LISTEN) {
1770 			release_sock(&smc->sk);
1771 			return -EINVAL;
1772 		}
1773 		if (smc->sk.sk_state == SMC_INIT ||
1774 		    smc->sk.sk_state == SMC_CLOSED)
1775 			answ = 0;
1776 		else
1777 			answ = smc_tx_prepared_sends(&smc->conn);
1778 		break;
1779 	case SIOCATMARK:
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 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
1789 			smc_curs_copy(&urg, &conn->urg_curs, conn);
1790 			answ = smc_curs_diff(conn->rmb_desc->len,
1791 					     &cons, &urg) == 1;
1792 		}
1793 		break;
1794 	default:
1795 		release_sock(&smc->sk);
1796 		return -ENOIOCTLCMD;
1797 	}
1798 	release_sock(&smc->sk);
1799 
1800 	return put_user(answ, (int __user *)arg);
1801 }
1802 
1803 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
1804 			    int offset, size_t size, int flags)
1805 {
1806 	struct sock *sk = sock->sk;
1807 	struct smc_sock *smc;
1808 	int rc = -EPIPE;
1809 
1810 	smc = smc_sk(sk);
1811 	lock_sock(sk);
1812 	if (sk->sk_state != SMC_ACTIVE) {
1813 		release_sock(sk);
1814 		goto out;
1815 	}
1816 	release_sock(sk);
1817 	if (smc->use_fallback)
1818 		rc = kernel_sendpage(smc->clcsock, page, offset,
1819 				     size, flags);
1820 	else
1821 		rc = sock_no_sendpage(sock, page, offset, size, flags);
1822 
1823 out:
1824 	return rc;
1825 }
1826 
1827 /* Map the affected portions of the rmbe into an spd, note the number of bytes
1828  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
1829  * updates till whenever a respective page has been fully processed.
1830  * Note that subsequent recv() calls have to wait till all splice() processing
1831  * completed.
1832  */
1833 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
1834 			       struct pipe_inode_info *pipe, size_t len,
1835 			       unsigned int flags)
1836 {
1837 	struct sock *sk = sock->sk;
1838 	struct smc_sock *smc;
1839 	int rc = -ENOTCONN;
1840 
1841 	smc = smc_sk(sk);
1842 	lock_sock(sk);
1843 
1844 	if (sk->sk_state == SMC_INIT ||
1845 	    sk->sk_state == SMC_LISTEN ||
1846 	    sk->sk_state == SMC_CLOSED)
1847 		goto out;
1848 
1849 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1850 		rc = 0;
1851 		goto out;
1852 	}
1853 
1854 	if (smc->use_fallback) {
1855 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
1856 						    pipe, len, flags);
1857 	} else {
1858 		if (*ppos) {
1859 			rc = -ESPIPE;
1860 			goto out;
1861 		}
1862 		if (flags & SPLICE_F_NONBLOCK)
1863 			flags = MSG_DONTWAIT;
1864 		else
1865 			flags = 0;
1866 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
1867 	}
1868 out:
1869 	release_sock(sk);
1870 
1871 	return rc;
1872 }
1873 
1874 /* must look like tcp */
1875 static const struct proto_ops smc_sock_ops = {
1876 	.family		= PF_SMC,
1877 	.owner		= THIS_MODULE,
1878 	.release	= smc_release,
1879 	.bind		= smc_bind,
1880 	.connect	= smc_connect,
1881 	.socketpair	= sock_no_socketpair,
1882 	.accept		= smc_accept,
1883 	.getname	= smc_getname,
1884 	.poll		= smc_poll,
1885 	.ioctl		= smc_ioctl,
1886 	.listen		= smc_listen,
1887 	.shutdown	= smc_shutdown,
1888 	.setsockopt	= smc_setsockopt,
1889 	.getsockopt	= smc_getsockopt,
1890 	.sendmsg	= smc_sendmsg,
1891 	.recvmsg	= smc_recvmsg,
1892 	.mmap		= sock_no_mmap,
1893 	.sendpage	= smc_sendpage,
1894 	.splice_read	= smc_splice_read,
1895 };
1896 
1897 static int smc_create(struct net *net, struct socket *sock, int protocol,
1898 		      int kern)
1899 {
1900 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
1901 	struct smc_sock *smc;
1902 	struct sock *sk;
1903 	int rc;
1904 
1905 	rc = -ESOCKTNOSUPPORT;
1906 	if (sock->type != SOCK_STREAM)
1907 		goto out;
1908 
1909 	rc = -EPROTONOSUPPORT;
1910 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
1911 		goto out;
1912 
1913 	rc = -ENOBUFS;
1914 	sock->ops = &smc_sock_ops;
1915 	sk = smc_sock_alloc(net, sock, protocol);
1916 	if (!sk)
1917 		goto out;
1918 
1919 	/* create internal TCP socket for CLC handshake and fallback */
1920 	smc = smc_sk(sk);
1921 	smc->use_fallback = false; /* assume rdma capability first */
1922 	smc->fallback_rsn = 0;
1923 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
1924 			      &smc->clcsock);
1925 	if (rc) {
1926 		sk_common_release(sk);
1927 		goto out;
1928 	}
1929 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
1930 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
1931 
1932 out:
1933 	return rc;
1934 }
1935 
1936 static const struct net_proto_family smc_sock_family_ops = {
1937 	.family	= PF_SMC,
1938 	.owner	= THIS_MODULE,
1939 	.create	= smc_create,
1940 };
1941 
1942 static int __init smc_init(void)
1943 {
1944 	int rc;
1945 
1946 	rc = smc_pnet_init();
1947 	if (rc)
1948 		return rc;
1949 
1950 	rc = smc_llc_init();
1951 	if (rc) {
1952 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
1953 		goto out_pnet;
1954 	}
1955 
1956 	rc = smc_cdc_init();
1957 	if (rc) {
1958 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
1959 		goto out_pnet;
1960 	}
1961 
1962 	rc = proto_register(&smc_proto, 1);
1963 	if (rc) {
1964 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
1965 		goto out_pnet;
1966 	}
1967 
1968 	rc = proto_register(&smc_proto6, 1);
1969 	if (rc) {
1970 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
1971 		goto out_proto;
1972 	}
1973 
1974 	rc = sock_register(&smc_sock_family_ops);
1975 	if (rc) {
1976 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
1977 		goto out_proto6;
1978 	}
1979 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
1980 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
1981 
1982 	rc = smc_ib_register_client();
1983 	if (rc) {
1984 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
1985 		goto out_sock;
1986 	}
1987 
1988 	static_branch_enable(&tcp_have_smc);
1989 	return 0;
1990 
1991 out_sock:
1992 	sock_unregister(PF_SMC);
1993 out_proto6:
1994 	proto_unregister(&smc_proto6);
1995 out_proto:
1996 	proto_unregister(&smc_proto);
1997 out_pnet:
1998 	smc_pnet_exit();
1999 	return rc;
2000 }
2001 
2002 static void __exit smc_exit(void)
2003 {
2004 	smc_core_exit();
2005 	static_branch_disable(&tcp_have_smc);
2006 	smc_ib_unregister_client();
2007 	sock_unregister(PF_SMC);
2008 	proto_unregister(&smc_proto6);
2009 	proto_unregister(&smc_proto);
2010 	smc_pnet_exit();
2011 }
2012 
2013 module_init(smc_init);
2014 module_exit(smc_exit);
2015 
2016 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
2017 MODULE_DESCRIPTION("smc socket address family");
2018 MODULE_LICENSE("GPL");
2019 MODULE_ALIAS_NETPROTO(PF_SMC);
2020