xref: /linux/net/smc/af_smc.c (revision 4ab5a5d2a4a2289c2af07accbec7170ca5671f41)
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 	if (smc->clcsock) {
150 		if (smc->use_fallback && sk->sk_state == SMC_LISTEN) {
151 			/* wake up clcsock accept */
152 			rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
153 		}
154 		mutex_lock(&smc->clcsock_release_lock);
155 		sock_release(smc->clcsock);
156 		smc->clcsock = NULL;
157 		mutex_unlock(&smc->clcsock_release_lock);
158 	}
159 	if (smc->use_fallback) {
160 		if (sk->sk_state != SMC_LISTEN && sk->sk_state != SMC_INIT)
161 			sock_put(sk); /* passive closing */
162 		sk->sk_state = SMC_CLOSED;
163 		sk->sk_state_change(sk);
164 	}
165 
166 	/* detach socket */
167 	sock_orphan(sk);
168 	sock->sk = NULL;
169 	if (!smc->use_fallback && sk->sk_state == SMC_CLOSED)
170 		smc_conn_free(&smc->conn);
171 	release_sock(sk);
172 
173 	sk->sk_prot->unhash(sk);
174 	sock_put(sk); /* final sock_put */
175 out:
176 	return rc;
177 }
178 
179 static void smc_destruct(struct sock *sk)
180 {
181 	if (sk->sk_state != SMC_CLOSED)
182 		return;
183 	if (!sock_flag(sk, SOCK_DEAD))
184 		return;
185 
186 	sk_refcnt_debug_dec(sk);
187 }
188 
189 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
190 				   int protocol)
191 {
192 	struct smc_sock *smc;
193 	struct proto *prot;
194 	struct sock *sk;
195 
196 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
197 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
198 	if (!sk)
199 		return NULL;
200 
201 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
202 	sk->sk_state = SMC_INIT;
203 	sk->sk_destruct = smc_destruct;
204 	sk->sk_protocol = protocol;
205 	smc = smc_sk(sk);
206 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
207 	INIT_WORK(&smc->connect_work, smc_connect_work);
208 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
209 	INIT_LIST_HEAD(&smc->accept_q);
210 	spin_lock_init(&smc->accept_q_lock);
211 	spin_lock_init(&smc->conn.send_lock);
212 	sk->sk_prot->hash(sk);
213 	sk_refcnt_debug_inc(sk);
214 	mutex_init(&smc->clcsock_release_lock);
215 
216 	return sk;
217 }
218 
219 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
220 		    int addr_len)
221 {
222 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
223 	struct sock *sk = sock->sk;
224 	struct smc_sock *smc;
225 	int rc;
226 
227 	smc = smc_sk(sk);
228 
229 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
230 	rc = -EINVAL;
231 	if (addr_len < sizeof(struct sockaddr_in))
232 		goto out;
233 
234 	rc = -EAFNOSUPPORT;
235 	if (addr->sin_family != AF_INET &&
236 	    addr->sin_family != AF_INET6 &&
237 	    addr->sin_family != AF_UNSPEC)
238 		goto out;
239 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
240 	if (addr->sin_family == AF_UNSPEC &&
241 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
242 		goto out;
243 
244 	lock_sock(sk);
245 
246 	/* Check if socket is already active */
247 	rc = -EINVAL;
248 	if (sk->sk_state != SMC_INIT)
249 		goto out_rel;
250 
251 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
252 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
253 
254 out_rel:
255 	release_sock(sk);
256 out:
257 	return rc;
258 }
259 
260 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
261 				   unsigned long mask)
262 {
263 	/* options we don't get control via setsockopt for */
264 	nsk->sk_type = osk->sk_type;
265 	nsk->sk_sndbuf = osk->sk_sndbuf;
266 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
267 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
268 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
269 	nsk->sk_mark = osk->sk_mark;
270 	nsk->sk_priority = osk->sk_priority;
271 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
272 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
273 	nsk->sk_err = osk->sk_err;
274 
275 	nsk->sk_flags &= ~mask;
276 	nsk->sk_flags |= osk->sk_flags & mask;
277 }
278 
279 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
280 			     (1UL << SOCK_KEEPOPEN) | \
281 			     (1UL << SOCK_LINGER) | \
282 			     (1UL << SOCK_BROADCAST) | \
283 			     (1UL << SOCK_TIMESTAMP) | \
284 			     (1UL << SOCK_DBG) | \
285 			     (1UL << SOCK_RCVTSTAMP) | \
286 			     (1UL << SOCK_RCVTSTAMPNS) | \
287 			     (1UL << SOCK_LOCALROUTE) | \
288 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
289 			     (1UL << SOCK_RXQ_OVFL) | \
290 			     (1UL << SOCK_WIFI_STATUS) | \
291 			     (1UL << SOCK_NOFCS) | \
292 			     (1UL << SOCK_FILTER_LOCKED))
293 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
294  * clc socket (since smc is not called for these options from net/core)
295  */
296 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
297 {
298 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
299 }
300 
301 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
302 			     (1UL << SOCK_KEEPOPEN) | \
303 			     (1UL << SOCK_LINGER) | \
304 			     (1UL << SOCK_DBG))
305 /* copy only settings and flags relevant for smc from clc to smc socket */
306 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
307 {
308 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
309 }
310 
311 /* register a new rmb, optionally send confirm_rkey msg to register with peer */
312 static int smc_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc,
313 		       bool conf_rkey)
314 {
315 	/* register memory region for new rmb */
316 	if (smc_wr_reg_send(link, rmb_desc->mr_rx[SMC_SINGLE_LINK])) {
317 		rmb_desc->regerr = 1;
318 		return -EFAULT;
319 	}
320 	if (!conf_rkey)
321 		return 0;
322 	/* exchange confirm_rkey msg with peer */
323 	if (smc_llc_do_confirm_rkey(link, rmb_desc)) {
324 		rmb_desc->regerr = 1;
325 		return -EFAULT;
326 	}
327 	return 0;
328 }
329 
330 static int smc_clnt_conf_first_link(struct smc_sock *smc)
331 {
332 	struct net *net = sock_net(smc->clcsock->sk);
333 	struct smc_link_group *lgr = smc->conn.lgr;
334 	struct smc_link *link;
335 	int rest;
336 	int rc;
337 
338 	link = &lgr->lnk[SMC_SINGLE_LINK];
339 	/* receive CONFIRM LINK request from server over RoCE fabric */
340 	rest = wait_for_completion_interruptible_timeout(
341 		&link->llc_confirm,
342 		SMC_LLC_WAIT_FIRST_TIME);
343 	if (rest <= 0) {
344 		struct smc_clc_msg_decline dclc;
345 
346 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
347 				      SMC_CLC_DECLINE);
348 		return rc;
349 	}
350 
351 	if (link->llc_confirm_rc)
352 		return SMC_CLC_DECL_RMBE_EC;
353 
354 	rc = smc_ib_modify_qp_rts(link);
355 	if (rc)
356 		return SMC_CLC_DECL_ERR_RDYLNK;
357 
358 	smc_wr_remember_qp_attr(link);
359 
360 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
361 		return SMC_CLC_DECL_ERR_REGRMB;
362 
363 	/* send CONFIRM LINK response over RoCE fabric */
364 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
365 	if (rc < 0)
366 		return SMC_CLC_DECL_TIMEOUT_CL;
367 
368 	/* receive ADD LINK request from server over RoCE fabric */
369 	rest = wait_for_completion_interruptible_timeout(&link->llc_add,
370 							 SMC_LLC_WAIT_TIME);
371 	if (rest <= 0) {
372 		struct smc_clc_msg_decline dclc;
373 
374 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
375 				      SMC_CLC_DECLINE);
376 		return rc;
377 	}
378 
379 	/* send add link reject message, only one link supported for now */
380 	rc = smc_llc_send_add_link(link,
381 				   link->smcibdev->mac[link->ibport - 1],
382 				   link->gid, SMC_LLC_RESP);
383 	if (rc < 0)
384 		return SMC_CLC_DECL_TIMEOUT_AL;
385 
386 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
387 
388 	return 0;
389 }
390 
391 static void smcr_conn_save_peer_info(struct smc_sock *smc,
392 				     struct smc_clc_msg_accept_confirm *clc)
393 {
394 	int bufsize = smc_uncompress_bufsize(clc->rmbe_size);
395 
396 	smc->conn.peer_rmbe_idx = clc->rmbe_idx;
397 	smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
398 	smc->conn.peer_rmbe_size = bufsize;
399 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
400 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
401 }
402 
403 static void smcd_conn_save_peer_info(struct smc_sock *smc,
404 				     struct smc_clc_msg_accept_confirm *clc)
405 {
406 	int bufsize = smc_uncompress_bufsize(clc->dmbe_size);
407 
408 	smc->conn.peer_rmbe_idx = clc->dmbe_idx;
409 	smc->conn.peer_token = clc->token;
410 	/* msg header takes up space in the buffer */
411 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
412 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
413 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
414 }
415 
416 static void smc_conn_save_peer_info(struct smc_sock *smc,
417 				    struct smc_clc_msg_accept_confirm *clc)
418 {
419 	if (smc->conn.lgr->is_smcd)
420 		smcd_conn_save_peer_info(smc, clc);
421 	else
422 		smcr_conn_save_peer_info(smc, clc);
423 }
424 
425 static void smc_link_save_peer_info(struct smc_link *link,
426 				    struct smc_clc_msg_accept_confirm *clc)
427 {
428 	link->peer_qpn = ntoh24(clc->qpn);
429 	memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
430 	memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
431 	link->peer_psn = ntoh24(clc->psn);
432 	link->peer_mtu = clc->qp_mtu;
433 }
434 
435 /* fall back during connect */
436 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
437 {
438 	smc->use_fallback = true;
439 	smc->fallback_rsn = reason_code;
440 	smc_copy_sock_settings_to_clc(smc);
441 	if (smc->sk.sk_state == SMC_INIT)
442 		smc->sk.sk_state = SMC_ACTIVE;
443 	return 0;
444 }
445 
446 /* decline and fall back during connect */
447 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code)
448 {
449 	int rc;
450 
451 	if (reason_code < 0) { /* error, fallback is not possible */
452 		if (smc->sk.sk_state == SMC_INIT)
453 			sock_put(&smc->sk); /* passive closing */
454 		return reason_code;
455 	}
456 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
457 		rc = smc_clc_send_decline(smc, reason_code);
458 		if (rc < 0) {
459 			if (smc->sk.sk_state == SMC_INIT)
460 				sock_put(&smc->sk); /* passive closing */
461 			return rc;
462 		}
463 	}
464 	return smc_connect_fallback(smc, reason_code);
465 }
466 
467 /* abort connecting */
468 static int smc_connect_abort(struct smc_sock *smc, int reason_code,
469 			     int local_contact)
470 {
471 	if (local_contact == SMC_FIRST_CONTACT)
472 		smc_lgr_forget(smc->conn.lgr);
473 	mutex_unlock(&smc_create_lgr_pending);
474 	smc_conn_free(&smc->conn);
475 	return reason_code;
476 }
477 
478 /* check if there is a rdma device available for this connection. */
479 /* called for connect and listen */
480 static int smc_check_rdma(struct smc_sock *smc, struct smc_ib_device **ibdev,
481 			  u8 *ibport, unsigned short vlan_id, u8 gid[])
482 {
483 	int reason_code = 0;
484 
485 	/* PNET table look up: search active ib_device and port
486 	 * within same PNETID that also contains the ethernet device
487 	 * used for the internal TCP socket
488 	 */
489 	smc_pnet_find_roce_resource(smc->clcsock->sk, ibdev, ibport, vlan_id,
490 				    gid);
491 	if (!(*ibdev))
492 		reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
493 
494 	return reason_code;
495 }
496 
497 /* check if there is an ISM device available for this connection. */
498 /* called for connect and listen */
499 static int smc_check_ism(struct smc_sock *smc, struct smcd_dev **ismdev)
500 {
501 	/* Find ISM device with same PNETID as connecting interface  */
502 	smc_pnet_find_ism_resource(smc->clcsock->sk, ismdev);
503 	if (!(*ismdev))
504 		return SMC_CLC_DECL_CNFERR; /* configuration error */
505 	return 0;
506 }
507 
508 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
509 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
510 				      struct smcd_dev *ismdev,
511 				      unsigned short vlan_id)
512 {
513 	if (vlan_id && smc_ism_get_vlan(ismdev, vlan_id))
514 		return SMC_CLC_DECL_CNFERR;
515 	return 0;
516 }
517 
518 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
519  * used, the VLAN ID will be registered again during the connection setup.
520  */
521 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc, bool is_smcd,
522 					struct smcd_dev *ismdev,
523 					unsigned short vlan_id)
524 {
525 	if (!is_smcd)
526 		return 0;
527 	if (vlan_id && smc_ism_put_vlan(ismdev, vlan_id))
528 		return SMC_CLC_DECL_CNFERR;
529 	return 0;
530 }
531 
532 /* CLC handshake during connect */
533 static int smc_connect_clc(struct smc_sock *smc, int smc_type,
534 			   struct smc_clc_msg_accept_confirm *aclc,
535 			   struct smc_ib_device *ibdev, u8 ibport,
536 			   u8 gid[], struct smcd_dev *ismdev)
537 {
538 	int rc = 0;
539 
540 	/* do inband token exchange */
541 	rc = smc_clc_send_proposal(smc, smc_type, ibdev, ibport, gid, ismdev);
542 	if (rc)
543 		return rc;
544 	/* receive SMC Accept CLC message */
545 	return smc_clc_wait_msg(smc, aclc, sizeof(*aclc), SMC_CLC_ACCEPT);
546 }
547 
548 /* setup for RDMA connection of client */
549 static int smc_connect_rdma(struct smc_sock *smc,
550 			    struct smc_clc_msg_accept_confirm *aclc,
551 			    struct smc_ib_device *ibdev, u8 ibport)
552 {
553 	int local_contact = SMC_FIRST_CONTACT;
554 	struct smc_link *link;
555 	int reason_code = 0;
556 
557 	mutex_lock(&smc_create_lgr_pending);
558 	local_contact = smc_conn_create(smc, false, aclc->hdr.flag, ibdev,
559 					ibport, ntoh24(aclc->qpn), &aclc->lcl,
560 					NULL, 0);
561 	if (local_contact < 0) {
562 		if (local_contact == -ENOMEM)
563 			reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
564 		else if (local_contact == -ENOLINK)
565 			reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
566 		else
567 			reason_code = SMC_CLC_DECL_INTERR; /* other error */
568 		return smc_connect_abort(smc, reason_code, 0);
569 	}
570 	link = &smc->conn.lgr->lnk[SMC_SINGLE_LINK];
571 
572 	smc_conn_save_peer_info(smc, aclc);
573 
574 	/* create send buffer and rmb */
575 	if (smc_buf_create(smc, false))
576 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM, local_contact);
577 
578 	if (local_contact == SMC_FIRST_CONTACT)
579 		smc_link_save_peer_info(link, aclc);
580 
581 	if (smc_rmb_rtoken_handling(&smc->conn, aclc))
582 		return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RTOK,
583 					 local_contact);
584 
585 	smc_close_init(smc);
586 	smc_rx_init(smc);
587 
588 	if (local_contact == SMC_FIRST_CONTACT) {
589 		if (smc_ib_ready_link(link))
590 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RDYLNK,
591 						 local_contact);
592 	} else {
593 		if (!smc->conn.rmb_desc->reused &&
594 		    smc_reg_rmb(link, smc->conn.rmb_desc, true))
595 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_REGRMB,
596 						 local_contact);
597 	}
598 	smc_rmb_sync_sg_for_device(&smc->conn);
599 
600 	reason_code = smc_clc_send_confirm(smc);
601 	if (reason_code)
602 		return smc_connect_abort(smc, reason_code, local_contact);
603 
604 	smc_tx_init(smc);
605 
606 	if (local_contact == SMC_FIRST_CONTACT) {
607 		/* QP confirmation over RoCE fabric */
608 		reason_code = smc_clnt_conf_first_link(smc);
609 		if (reason_code)
610 			return smc_connect_abort(smc, reason_code,
611 						 local_contact);
612 	}
613 	mutex_unlock(&smc_create_lgr_pending);
614 
615 	smc_copy_sock_settings_to_clc(smc);
616 	if (smc->sk.sk_state == SMC_INIT)
617 		smc->sk.sk_state = SMC_ACTIVE;
618 
619 	return 0;
620 }
621 
622 /* setup for ISM connection of client */
623 static int smc_connect_ism(struct smc_sock *smc,
624 			   struct smc_clc_msg_accept_confirm *aclc,
625 			   struct smcd_dev *ismdev)
626 {
627 	int local_contact = SMC_FIRST_CONTACT;
628 	int rc = 0;
629 
630 	mutex_lock(&smc_create_lgr_pending);
631 	local_contact = smc_conn_create(smc, true, aclc->hdr.flag, NULL, 0, 0,
632 					NULL, ismdev, aclc->gid);
633 	if (local_contact < 0)
634 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM, 0);
635 
636 	/* Create send and receive buffers */
637 	if (smc_buf_create(smc, true))
638 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM, local_contact);
639 
640 	smc_conn_save_peer_info(smc, aclc);
641 	smc_close_init(smc);
642 	smc_rx_init(smc);
643 	smc_tx_init(smc);
644 
645 	rc = smc_clc_send_confirm(smc);
646 	if (rc)
647 		return smc_connect_abort(smc, rc, local_contact);
648 	mutex_unlock(&smc_create_lgr_pending);
649 
650 	smc_copy_sock_settings_to_clc(smc);
651 	if (smc->sk.sk_state == SMC_INIT)
652 		smc->sk.sk_state = SMC_ACTIVE;
653 
654 	return 0;
655 }
656 
657 /* perform steps before actually connecting */
658 static int __smc_connect(struct smc_sock *smc)
659 {
660 	bool ism_supported = false, rdma_supported = false;
661 	struct smc_clc_msg_accept_confirm aclc;
662 	struct smc_ib_device *ibdev;
663 	struct smcd_dev *ismdev;
664 	u8 gid[SMC_GID_SIZE];
665 	unsigned short vlan;
666 	int smc_type;
667 	int rc = 0;
668 	u8 ibport;
669 
670 	sock_hold(&smc->sk); /* sock put in passive closing */
671 
672 	if (smc->use_fallback)
673 		return smc_connect_fallback(smc, smc->fallback_rsn);
674 
675 	/* if peer has not signalled SMC-capability, fall back */
676 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
677 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
678 
679 	/* IPSec connections opt out of SMC-R optimizations */
680 	if (using_ipsec(smc))
681 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC);
682 
683 	/* check for VLAN ID */
684 	if (smc_vlan_by_tcpsk(smc->clcsock, &vlan))
685 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_CNFERR);
686 
687 	/* check if there is an ism device available */
688 	if (!smc_check_ism(smc, &ismdev) &&
689 	    !smc_connect_ism_vlan_setup(smc, ismdev, vlan)) {
690 		/* ISM is supported for this connection */
691 		ism_supported = true;
692 		smc_type = SMC_TYPE_D;
693 	}
694 
695 	/* check if there is a rdma device available */
696 	if (!smc_check_rdma(smc, &ibdev, &ibport, vlan, gid)) {
697 		/* RDMA is supported for this connection */
698 		rdma_supported = true;
699 		if (ism_supported)
700 			smc_type = SMC_TYPE_B; /* both */
701 		else
702 			smc_type = SMC_TYPE_R; /* only RDMA */
703 	}
704 
705 	/* if neither ISM nor RDMA are supported, fallback */
706 	if (!rdma_supported && !ism_supported)
707 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_NOSMCDEV);
708 
709 	/* perform CLC handshake */
710 	rc = smc_connect_clc(smc, smc_type, &aclc, ibdev, ibport, gid, ismdev);
711 	if (rc) {
712 		smc_connect_ism_vlan_cleanup(smc, ism_supported, ismdev, vlan);
713 		return smc_connect_decline_fallback(smc, rc);
714 	}
715 
716 	/* depending on previous steps, connect using rdma or ism */
717 	if (rdma_supported && aclc.hdr.path == SMC_TYPE_R)
718 		rc = smc_connect_rdma(smc, &aclc, ibdev, ibport);
719 	else if (ism_supported && aclc.hdr.path == SMC_TYPE_D)
720 		rc = smc_connect_ism(smc, &aclc, ismdev);
721 	else
722 		rc = SMC_CLC_DECL_MODEUNSUPP;
723 	if (rc) {
724 		smc_connect_ism_vlan_cleanup(smc, ism_supported, ismdev, vlan);
725 		return smc_connect_decline_fallback(smc, rc);
726 	}
727 
728 	smc_connect_ism_vlan_cleanup(smc, ism_supported, ismdev, vlan);
729 	return 0;
730 }
731 
732 static void smc_connect_work(struct work_struct *work)
733 {
734 	struct smc_sock *smc = container_of(work, struct smc_sock,
735 					    connect_work);
736 	int rc;
737 
738 	lock_sock(&smc->sk);
739 	rc = kernel_connect(smc->clcsock, &smc->connect_info->addr,
740 			    smc->connect_info->alen, smc->connect_info->flags);
741 	if (smc->clcsock->sk->sk_err) {
742 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
743 		goto out;
744 	}
745 	if (rc < 0) {
746 		smc->sk.sk_err = -rc;
747 		goto out;
748 	}
749 
750 	rc = __smc_connect(smc);
751 	if (rc < 0)
752 		smc->sk.sk_err = -rc;
753 
754 out:
755 	if (smc->sk.sk_err)
756 		smc->sk.sk_state_change(&smc->sk);
757 	else
758 		smc->sk.sk_write_space(&smc->sk);
759 	kfree(smc->connect_info);
760 	smc->connect_info = NULL;
761 	release_sock(&smc->sk);
762 }
763 
764 static int smc_connect(struct socket *sock, struct sockaddr *addr,
765 		       int alen, int flags)
766 {
767 	struct sock *sk = sock->sk;
768 	struct smc_sock *smc;
769 	int rc = -EINVAL;
770 
771 	smc = smc_sk(sk);
772 
773 	/* separate smc parameter checking to be safe */
774 	if (alen < sizeof(addr->sa_family))
775 		goto out_err;
776 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
777 		goto out_err;
778 
779 	lock_sock(sk);
780 	switch (sk->sk_state) {
781 	default:
782 		goto out;
783 	case SMC_ACTIVE:
784 		rc = -EISCONN;
785 		goto out;
786 	case SMC_INIT:
787 		rc = 0;
788 		break;
789 	}
790 
791 	smc_copy_sock_settings_to_clc(smc);
792 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
793 	if (flags & O_NONBLOCK) {
794 		if (smc->connect_info) {
795 			rc = -EALREADY;
796 			goto out;
797 		}
798 		smc->connect_info = kzalloc(alen + 2 * sizeof(int), GFP_KERNEL);
799 		if (!smc->connect_info) {
800 			rc = -ENOMEM;
801 			goto out;
802 		}
803 		smc->connect_info->alen = alen;
804 		smc->connect_info->flags = flags ^ O_NONBLOCK;
805 		memcpy(&smc->connect_info->addr, addr, alen);
806 		schedule_work(&smc->connect_work);
807 		rc = -EINPROGRESS;
808 	} else {
809 		rc = kernel_connect(smc->clcsock, addr, alen, flags);
810 		if (rc)
811 			goto out;
812 
813 		rc = __smc_connect(smc);
814 		if (rc < 0)
815 			goto out;
816 		else
817 			rc = 0; /* success cases including fallback */
818 	}
819 
820 out:
821 	release_sock(sk);
822 out_err:
823 	return rc;
824 }
825 
826 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
827 {
828 	struct socket *new_clcsock = NULL;
829 	struct sock *lsk = &lsmc->sk;
830 	struct sock *new_sk;
831 	int rc = -EINVAL;
832 
833 	release_sock(lsk);
834 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
835 	if (!new_sk) {
836 		rc = -ENOMEM;
837 		lsk->sk_err = ENOMEM;
838 		*new_smc = NULL;
839 		lock_sock(lsk);
840 		goto out;
841 	}
842 	*new_smc = smc_sk(new_sk);
843 
844 	mutex_lock(&lsmc->clcsock_release_lock);
845 	if (lsmc->clcsock)
846 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
847 	mutex_unlock(&lsmc->clcsock_release_lock);
848 	lock_sock(lsk);
849 	if  (rc < 0)
850 		lsk->sk_err = -rc;
851 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
852 		if (new_clcsock)
853 			sock_release(new_clcsock);
854 		new_sk->sk_state = SMC_CLOSED;
855 		sock_set_flag(new_sk, SOCK_DEAD);
856 		new_sk->sk_prot->unhash(new_sk);
857 		sock_put(new_sk); /* final */
858 		*new_smc = NULL;
859 		goto out;
860 	}
861 
862 	(*new_smc)->clcsock = new_clcsock;
863 out:
864 	return rc;
865 }
866 
867 /* add a just created sock to the accept queue of the listen sock as
868  * candidate for a following socket accept call from user space
869  */
870 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
871 {
872 	struct smc_sock *par = smc_sk(parent);
873 
874 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
875 	spin_lock(&par->accept_q_lock);
876 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
877 	spin_unlock(&par->accept_q_lock);
878 	sk_acceptq_added(parent);
879 }
880 
881 /* remove a socket from the accept queue of its parental listening socket */
882 static void smc_accept_unlink(struct sock *sk)
883 {
884 	struct smc_sock *par = smc_sk(sk)->listen_smc;
885 
886 	spin_lock(&par->accept_q_lock);
887 	list_del_init(&smc_sk(sk)->accept_q);
888 	spin_unlock(&par->accept_q_lock);
889 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
890 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
891 }
892 
893 /* remove a sock from the accept queue to bind it to a new socket created
894  * for a socket accept call from user space
895  */
896 struct sock *smc_accept_dequeue(struct sock *parent,
897 				struct socket *new_sock)
898 {
899 	struct smc_sock *isk, *n;
900 	struct sock *new_sk;
901 
902 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
903 		new_sk = (struct sock *)isk;
904 
905 		smc_accept_unlink(new_sk);
906 		if (new_sk->sk_state == SMC_CLOSED) {
907 			if (isk->clcsock) {
908 				sock_release(isk->clcsock);
909 				isk->clcsock = NULL;
910 			}
911 			new_sk->sk_prot->unhash(new_sk);
912 			sock_put(new_sk); /* final */
913 			continue;
914 		}
915 		if (new_sock)
916 			sock_graft(new_sk, new_sock);
917 		return new_sk;
918 	}
919 	return NULL;
920 }
921 
922 /* clean up for a created but never accepted sock */
923 void smc_close_non_accepted(struct sock *sk)
924 {
925 	struct smc_sock *smc = smc_sk(sk);
926 
927 	lock_sock(sk);
928 	if (!sk->sk_lingertime)
929 		/* wait for peer closing */
930 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
931 	if (!smc->use_fallback) {
932 		smc_close_active(smc);
933 		sock_set_flag(sk, SOCK_DEAD);
934 		sk->sk_shutdown |= SHUTDOWN_MASK;
935 	}
936 	if (smc->clcsock) {
937 		struct socket *tcp;
938 
939 		tcp = smc->clcsock;
940 		smc->clcsock = NULL;
941 		sock_release(tcp);
942 	}
943 	if (smc->use_fallback) {
944 		sock_put(sk); /* passive closing */
945 		sk->sk_state = SMC_CLOSED;
946 	} else {
947 		if (sk->sk_state == SMC_CLOSED)
948 			smc_conn_free(&smc->conn);
949 	}
950 	release_sock(sk);
951 	sk->sk_prot->unhash(sk);
952 	sock_put(sk); /* final sock_put */
953 }
954 
955 static int smc_serv_conf_first_link(struct smc_sock *smc)
956 {
957 	struct net *net = sock_net(smc->clcsock->sk);
958 	struct smc_link_group *lgr = smc->conn.lgr;
959 	struct smc_link *link;
960 	int rest;
961 	int rc;
962 
963 	link = &lgr->lnk[SMC_SINGLE_LINK];
964 
965 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
966 		return SMC_CLC_DECL_ERR_REGRMB;
967 
968 	/* send CONFIRM LINK request to client over the RoCE fabric */
969 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
970 	if (rc < 0)
971 		return SMC_CLC_DECL_TIMEOUT_CL;
972 
973 	/* receive CONFIRM LINK response from client over the RoCE fabric */
974 	rest = wait_for_completion_interruptible_timeout(
975 		&link->llc_confirm_resp,
976 		SMC_LLC_WAIT_FIRST_TIME);
977 	if (rest <= 0) {
978 		struct smc_clc_msg_decline dclc;
979 
980 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
981 				      SMC_CLC_DECLINE);
982 		return rc;
983 	}
984 
985 	if (link->llc_confirm_resp_rc)
986 		return SMC_CLC_DECL_RMBE_EC;
987 
988 	/* send ADD LINK request to client over the RoCE fabric */
989 	rc = smc_llc_send_add_link(link,
990 				   link->smcibdev->mac[link->ibport - 1],
991 				   link->gid, SMC_LLC_REQ);
992 	if (rc < 0)
993 		return SMC_CLC_DECL_TIMEOUT_AL;
994 
995 	/* receive ADD LINK response from client over the RoCE fabric */
996 	rest = wait_for_completion_interruptible_timeout(&link->llc_add_resp,
997 							 SMC_LLC_WAIT_TIME);
998 	if (rest <= 0) {
999 		struct smc_clc_msg_decline dclc;
1000 
1001 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1002 				      SMC_CLC_DECLINE);
1003 		return rc;
1004 	}
1005 
1006 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
1007 
1008 	return 0;
1009 }
1010 
1011 /* listen worker: finish */
1012 static void smc_listen_out(struct smc_sock *new_smc)
1013 {
1014 	struct smc_sock *lsmc = new_smc->listen_smc;
1015 	struct sock *newsmcsk = &new_smc->sk;
1016 
1017 	lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1018 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1019 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1020 	} else { /* no longer listening */
1021 		smc_close_non_accepted(newsmcsk);
1022 	}
1023 	release_sock(&lsmc->sk);
1024 
1025 	/* Wake up accept */
1026 	lsmc->sk.sk_data_ready(&lsmc->sk);
1027 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1028 }
1029 
1030 /* listen worker: finish in state connected */
1031 static void smc_listen_out_connected(struct smc_sock *new_smc)
1032 {
1033 	struct sock *newsmcsk = &new_smc->sk;
1034 
1035 	sk_refcnt_debug_inc(newsmcsk);
1036 	if (newsmcsk->sk_state == SMC_INIT)
1037 		newsmcsk->sk_state = SMC_ACTIVE;
1038 
1039 	smc_listen_out(new_smc);
1040 }
1041 
1042 /* listen worker: finish in error state */
1043 static void smc_listen_out_err(struct smc_sock *new_smc)
1044 {
1045 	struct sock *newsmcsk = &new_smc->sk;
1046 
1047 	if (newsmcsk->sk_state == SMC_INIT)
1048 		sock_put(&new_smc->sk); /* passive closing */
1049 	newsmcsk->sk_state = SMC_CLOSED;
1050 	smc_conn_free(&new_smc->conn);
1051 
1052 	smc_listen_out(new_smc);
1053 }
1054 
1055 /* listen worker: decline and fall back if possible */
1056 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1057 			       int local_contact)
1058 {
1059 	/* RDMA setup failed, switch back to TCP */
1060 	if (local_contact == SMC_FIRST_CONTACT)
1061 		smc_lgr_forget(new_smc->conn.lgr);
1062 	if (reason_code < 0) { /* error, no fallback possible */
1063 		smc_listen_out_err(new_smc);
1064 		return;
1065 	}
1066 	smc_conn_free(&new_smc->conn);
1067 	new_smc->use_fallback = true;
1068 	new_smc->fallback_rsn = reason_code;
1069 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1070 		if (smc_clc_send_decline(new_smc, reason_code) < 0) {
1071 			smc_listen_out_err(new_smc);
1072 			return;
1073 		}
1074 	}
1075 	smc_listen_out_connected(new_smc);
1076 }
1077 
1078 /* listen worker: check prefixes */
1079 static int smc_listen_rdma_check(struct smc_sock *new_smc,
1080 				 struct smc_clc_msg_proposal *pclc)
1081 {
1082 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1083 	struct socket *newclcsock = new_smc->clcsock;
1084 
1085 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1086 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1087 		return SMC_CLC_DECL_CNFERR;
1088 
1089 	return 0;
1090 }
1091 
1092 /* listen worker: initialize connection and buffers */
1093 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1094 				struct smc_clc_msg_proposal *pclc,
1095 				struct smc_ib_device *ibdev, u8 ibport,
1096 				int *local_contact)
1097 {
1098 	/* allocate connection / link group */
1099 	*local_contact = smc_conn_create(new_smc, false, 0, ibdev, ibport, 0,
1100 					 &pclc->lcl, NULL, 0);
1101 	if (*local_contact < 0) {
1102 		if (*local_contact == -ENOMEM)
1103 			return SMC_CLC_DECL_MEM;/* insufficient memory*/
1104 		return SMC_CLC_DECL_INTERR; /* other error */
1105 	}
1106 
1107 	/* create send buffer and rmb */
1108 	if (smc_buf_create(new_smc, false))
1109 		return SMC_CLC_DECL_MEM;
1110 
1111 	return 0;
1112 }
1113 
1114 /* listen worker: initialize connection and buffers for SMC-D */
1115 static int smc_listen_ism_init(struct smc_sock *new_smc,
1116 			       struct smc_clc_msg_proposal *pclc,
1117 			       struct smcd_dev *ismdev,
1118 			       int *local_contact)
1119 {
1120 	struct smc_clc_msg_smcd *pclc_smcd;
1121 
1122 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
1123 	*local_contact = smc_conn_create(new_smc, true, 0, NULL, 0, 0, NULL,
1124 					 ismdev, pclc_smcd->gid);
1125 	if (*local_contact < 0) {
1126 		if (*local_contact == -ENOMEM)
1127 			return SMC_CLC_DECL_MEM;/* insufficient memory*/
1128 		return SMC_CLC_DECL_INTERR; /* other error */
1129 	}
1130 
1131 	/* Check if peer can be reached via ISM device */
1132 	if (smc_ism_cantalk(new_smc->conn.lgr->peer_gid,
1133 			    new_smc->conn.lgr->vlan_id,
1134 			    new_smc->conn.lgr->smcd)) {
1135 		if (*local_contact == SMC_FIRST_CONTACT)
1136 			smc_lgr_forget(new_smc->conn.lgr);
1137 		smc_conn_free(&new_smc->conn);
1138 		return SMC_CLC_DECL_CNFERR;
1139 	}
1140 
1141 	/* Create send and receive buffers */
1142 	if (smc_buf_create(new_smc, true)) {
1143 		if (*local_contact == SMC_FIRST_CONTACT)
1144 			smc_lgr_forget(new_smc->conn.lgr);
1145 		smc_conn_free(&new_smc->conn);
1146 		return SMC_CLC_DECL_MEM;
1147 	}
1148 
1149 	return 0;
1150 }
1151 
1152 /* listen worker: register buffers */
1153 static int smc_listen_rdma_reg(struct smc_sock *new_smc, int local_contact)
1154 {
1155 	struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
1156 
1157 	if (local_contact != SMC_FIRST_CONTACT) {
1158 		if (!new_smc->conn.rmb_desc->reused) {
1159 			if (smc_reg_rmb(link, new_smc->conn.rmb_desc, true))
1160 				return SMC_CLC_DECL_ERR_REGRMB;
1161 		}
1162 	}
1163 	smc_rmb_sync_sg_for_device(&new_smc->conn);
1164 
1165 	return 0;
1166 }
1167 
1168 /* listen worker: finish RDMA setup */
1169 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
1170 				  struct smc_clc_msg_accept_confirm *cclc,
1171 				  int local_contact)
1172 {
1173 	struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
1174 	int reason_code = 0;
1175 
1176 	if (local_contact == SMC_FIRST_CONTACT)
1177 		smc_link_save_peer_info(link, cclc);
1178 
1179 	if (smc_rmb_rtoken_handling(&new_smc->conn, cclc)) {
1180 		reason_code = SMC_CLC_DECL_ERR_RTOK;
1181 		goto decline;
1182 	}
1183 
1184 	if (local_contact == SMC_FIRST_CONTACT) {
1185 		if (smc_ib_ready_link(link)) {
1186 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
1187 			goto decline;
1188 		}
1189 		/* QP confirmation over RoCE fabric */
1190 		reason_code = smc_serv_conf_first_link(new_smc);
1191 		if (reason_code)
1192 			goto decline;
1193 	}
1194 	return 0;
1195 
1196 decline:
1197 	mutex_unlock(&smc_create_lgr_pending);
1198 	smc_listen_decline(new_smc, reason_code, local_contact);
1199 	return reason_code;
1200 }
1201 
1202 /* setup for RDMA connection of server */
1203 static void smc_listen_work(struct work_struct *work)
1204 {
1205 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
1206 						smc_listen_work);
1207 	struct socket *newclcsock = new_smc->clcsock;
1208 	struct smc_clc_msg_accept_confirm cclc;
1209 	struct smc_clc_msg_proposal *pclc;
1210 	struct smc_ib_device *ibdev;
1211 	bool ism_supported = false;
1212 	struct smcd_dev *ismdev;
1213 	u8 buf[SMC_CLC_MAX_LEN];
1214 	int local_contact = 0;
1215 	unsigned short vlan;
1216 	int reason_code = 0;
1217 	int rc = 0;
1218 	u8 ibport;
1219 
1220 	if (new_smc->use_fallback) {
1221 		smc_listen_out_connected(new_smc);
1222 		return;
1223 	}
1224 
1225 	/* check if peer is smc capable */
1226 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
1227 		new_smc->use_fallback = true;
1228 		new_smc->fallback_rsn = SMC_CLC_DECL_PEERNOSMC;
1229 		smc_listen_out_connected(new_smc);
1230 		return;
1231 	}
1232 
1233 	/* do inband token exchange -
1234 	 * wait for and receive SMC Proposal CLC message
1235 	 */
1236 	pclc = (struct smc_clc_msg_proposal *)&buf;
1237 	reason_code = smc_clc_wait_msg(new_smc, pclc, SMC_CLC_MAX_LEN,
1238 				       SMC_CLC_PROPOSAL);
1239 	if (reason_code) {
1240 		smc_listen_decline(new_smc, reason_code, 0);
1241 		return;
1242 	}
1243 
1244 	/* IPSec connections opt out of SMC-R optimizations */
1245 	if (using_ipsec(new_smc)) {
1246 		smc_listen_decline(new_smc, SMC_CLC_DECL_IPSEC, 0);
1247 		return;
1248 	}
1249 
1250 	mutex_lock(&smc_create_lgr_pending);
1251 	smc_close_init(new_smc);
1252 	smc_rx_init(new_smc);
1253 	smc_tx_init(new_smc);
1254 
1255 	/* check if ISM is available */
1256 	if ((pclc->hdr.path == SMC_TYPE_D || pclc->hdr.path == SMC_TYPE_B) &&
1257 	    !smc_check_ism(new_smc, &ismdev) &&
1258 	    !smc_listen_ism_init(new_smc, pclc, ismdev, &local_contact)) {
1259 		ism_supported = true;
1260 	}
1261 
1262 	/* check if RDMA is available */
1263 	if (!ism_supported &&
1264 	    ((pclc->hdr.path != SMC_TYPE_R && pclc->hdr.path != SMC_TYPE_B) ||
1265 	     smc_vlan_by_tcpsk(new_smc->clcsock, &vlan) ||
1266 	     smc_check_rdma(new_smc, &ibdev, &ibport, vlan, NULL) ||
1267 	     smc_listen_rdma_check(new_smc, pclc) ||
1268 	     smc_listen_rdma_init(new_smc, pclc, ibdev, ibport,
1269 				  &local_contact) ||
1270 	     smc_listen_rdma_reg(new_smc, local_contact))) {
1271 		/* SMC not supported, decline */
1272 		mutex_unlock(&smc_create_lgr_pending);
1273 		smc_listen_decline(new_smc, SMC_CLC_DECL_MODEUNSUPP,
1274 				   local_contact);
1275 		return;
1276 	}
1277 
1278 	/* send SMC Accept CLC message */
1279 	rc = smc_clc_send_accept(new_smc, local_contact);
1280 	if (rc) {
1281 		mutex_unlock(&smc_create_lgr_pending);
1282 		smc_listen_decline(new_smc, rc, local_contact);
1283 		return;
1284 	}
1285 
1286 	/* receive SMC Confirm CLC message */
1287 	reason_code = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
1288 				       SMC_CLC_CONFIRM);
1289 	if (reason_code) {
1290 		mutex_unlock(&smc_create_lgr_pending);
1291 		smc_listen_decline(new_smc, reason_code, local_contact);
1292 		return;
1293 	}
1294 
1295 	/* finish worker */
1296 	if (!ism_supported) {
1297 		if (smc_listen_rdma_finish(new_smc, &cclc, local_contact))
1298 			return;
1299 	}
1300 	smc_conn_save_peer_info(new_smc, &cclc);
1301 	mutex_unlock(&smc_create_lgr_pending);
1302 	smc_listen_out_connected(new_smc);
1303 }
1304 
1305 static void smc_tcp_listen_work(struct work_struct *work)
1306 {
1307 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
1308 					     tcp_listen_work);
1309 	struct sock *lsk = &lsmc->sk;
1310 	struct smc_sock *new_smc;
1311 	int rc = 0;
1312 
1313 	lock_sock(lsk);
1314 	while (lsk->sk_state == SMC_LISTEN) {
1315 		rc = smc_clcsock_accept(lsmc, &new_smc);
1316 		if (rc)
1317 			goto out;
1318 		if (!new_smc)
1319 			continue;
1320 
1321 		new_smc->listen_smc = lsmc;
1322 		new_smc->use_fallback = lsmc->use_fallback;
1323 		new_smc->fallback_rsn = lsmc->fallback_rsn;
1324 		sock_hold(lsk); /* sock_put in smc_listen_work */
1325 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
1326 		smc_copy_sock_settings_to_smc(new_smc);
1327 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
1328 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
1329 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
1330 		if (!schedule_work(&new_smc->smc_listen_work))
1331 			sock_put(&new_smc->sk);
1332 	}
1333 
1334 out:
1335 	release_sock(lsk);
1336 	sock_put(&lsmc->sk); /* sock_hold in smc_listen */
1337 }
1338 
1339 static int smc_listen(struct socket *sock, int backlog)
1340 {
1341 	struct sock *sk = sock->sk;
1342 	struct smc_sock *smc;
1343 	int rc;
1344 
1345 	smc = smc_sk(sk);
1346 	lock_sock(sk);
1347 
1348 	rc = -EINVAL;
1349 	if ((sk->sk_state != SMC_INIT) && (sk->sk_state != SMC_LISTEN))
1350 		goto out;
1351 
1352 	rc = 0;
1353 	if (sk->sk_state == SMC_LISTEN) {
1354 		sk->sk_max_ack_backlog = backlog;
1355 		goto out;
1356 	}
1357 	/* some socket options are handled in core, so we could not apply
1358 	 * them to the clc socket -- copy smc socket options to clc socket
1359 	 */
1360 	smc_copy_sock_settings_to_clc(smc);
1361 	if (!smc->use_fallback)
1362 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1363 
1364 	rc = kernel_listen(smc->clcsock, backlog);
1365 	if (rc)
1366 		goto out;
1367 	sk->sk_max_ack_backlog = backlog;
1368 	sk->sk_ack_backlog = 0;
1369 	sk->sk_state = SMC_LISTEN;
1370 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
1371 	sock_hold(sk); /* sock_hold in tcp_listen_worker */
1372 	if (!schedule_work(&smc->tcp_listen_work))
1373 		sock_put(sk);
1374 
1375 out:
1376 	release_sock(sk);
1377 	return rc;
1378 }
1379 
1380 static int smc_accept(struct socket *sock, struct socket *new_sock,
1381 		      int flags, bool kern)
1382 {
1383 	struct sock *sk = sock->sk, *nsk;
1384 	DECLARE_WAITQUEUE(wait, current);
1385 	struct smc_sock *lsmc;
1386 	long timeo;
1387 	int rc = 0;
1388 
1389 	lsmc = smc_sk(sk);
1390 	sock_hold(sk); /* sock_put below */
1391 	lock_sock(sk);
1392 
1393 	if (lsmc->sk.sk_state != SMC_LISTEN) {
1394 		rc = -EINVAL;
1395 		release_sock(sk);
1396 		goto out;
1397 	}
1398 
1399 	/* Wait for an incoming connection */
1400 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1401 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
1402 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1403 		set_current_state(TASK_INTERRUPTIBLE);
1404 		if (!timeo) {
1405 			rc = -EAGAIN;
1406 			break;
1407 		}
1408 		release_sock(sk);
1409 		timeo = schedule_timeout(timeo);
1410 		/* wakeup by sk_data_ready in smc_listen_work() */
1411 		sched_annotate_sleep();
1412 		lock_sock(sk);
1413 		if (signal_pending(current)) {
1414 			rc = sock_intr_errno(timeo);
1415 			break;
1416 		}
1417 	}
1418 	set_current_state(TASK_RUNNING);
1419 	remove_wait_queue(sk_sleep(sk), &wait);
1420 
1421 	if (!rc)
1422 		rc = sock_error(nsk);
1423 	release_sock(sk);
1424 	if (rc)
1425 		goto out;
1426 
1427 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
1428 		/* wait till data arrives on the socket */
1429 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
1430 								MSEC_PER_SEC);
1431 		if (smc_sk(nsk)->use_fallback) {
1432 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
1433 
1434 			lock_sock(clcsk);
1435 			if (skb_queue_empty(&clcsk->sk_receive_queue))
1436 				sk_wait_data(clcsk, &timeo, NULL);
1437 			release_sock(clcsk);
1438 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
1439 			lock_sock(nsk);
1440 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
1441 			release_sock(nsk);
1442 		}
1443 	}
1444 
1445 out:
1446 	sock_put(sk); /* sock_hold above */
1447 	return rc;
1448 }
1449 
1450 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1451 		       int peer)
1452 {
1453 	struct smc_sock *smc;
1454 
1455 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
1456 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
1457 		return -ENOTCONN;
1458 
1459 	smc = smc_sk(sock->sk);
1460 
1461 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
1462 }
1463 
1464 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1465 {
1466 	struct sock *sk = sock->sk;
1467 	struct smc_sock *smc;
1468 	int rc = -EPIPE;
1469 
1470 	smc = smc_sk(sk);
1471 	lock_sock(sk);
1472 	if ((sk->sk_state != SMC_ACTIVE) &&
1473 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1474 	    (sk->sk_state != SMC_INIT))
1475 		goto out;
1476 
1477 	if (msg->msg_flags & MSG_FASTOPEN) {
1478 		if (sk->sk_state == SMC_INIT) {
1479 			smc->use_fallback = true;
1480 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1481 		} else {
1482 			rc = -EINVAL;
1483 			goto out;
1484 		}
1485 	}
1486 
1487 	if (smc->use_fallback)
1488 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
1489 	else
1490 		rc = smc_tx_sendmsg(smc, msg, len);
1491 out:
1492 	release_sock(sk);
1493 	return rc;
1494 }
1495 
1496 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1497 		       int flags)
1498 {
1499 	struct sock *sk = sock->sk;
1500 	struct smc_sock *smc;
1501 	int rc = -ENOTCONN;
1502 
1503 	smc = smc_sk(sk);
1504 	lock_sock(sk);
1505 	if ((sk->sk_state == SMC_INIT) ||
1506 	    (sk->sk_state == SMC_LISTEN) ||
1507 	    (sk->sk_state == SMC_CLOSED))
1508 		goto out;
1509 
1510 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1511 		rc = 0;
1512 		goto out;
1513 	}
1514 
1515 	if (smc->use_fallback) {
1516 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
1517 	} else {
1518 		msg->msg_namelen = 0;
1519 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
1520 	}
1521 
1522 out:
1523 	release_sock(sk);
1524 	return rc;
1525 }
1526 
1527 static __poll_t smc_accept_poll(struct sock *parent)
1528 {
1529 	struct smc_sock *isk = smc_sk(parent);
1530 	__poll_t mask = 0;
1531 
1532 	spin_lock(&isk->accept_q_lock);
1533 	if (!list_empty(&isk->accept_q))
1534 		mask = EPOLLIN | EPOLLRDNORM;
1535 	spin_unlock(&isk->accept_q_lock);
1536 
1537 	return mask;
1538 }
1539 
1540 static __poll_t smc_poll(struct file *file, struct socket *sock,
1541 			     poll_table *wait)
1542 {
1543 	struct sock *sk = sock->sk;
1544 	__poll_t mask = 0;
1545 	struct smc_sock *smc;
1546 
1547 	if (!sk)
1548 		return EPOLLNVAL;
1549 
1550 	smc = smc_sk(sock->sk);
1551 	if (smc->use_fallback) {
1552 		/* delegate to CLC child sock */
1553 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
1554 		sk->sk_err = smc->clcsock->sk->sk_err;
1555 		if (sk->sk_err)
1556 			mask |= EPOLLERR;
1557 	} else {
1558 		if (sk->sk_state != SMC_CLOSED)
1559 			sock_poll_wait(file, sock, wait);
1560 		if (sk->sk_err)
1561 			mask |= EPOLLERR;
1562 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1563 		    (sk->sk_state == SMC_CLOSED))
1564 			mask |= EPOLLHUP;
1565 		if (sk->sk_state == SMC_LISTEN) {
1566 			/* woken up by sk_data_ready in smc_listen_work() */
1567 			mask = smc_accept_poll(sk);
1568 		} else {
1569 			if (atomic_read(&smc->conn.sndbuf_space) ||
1570 			    sk->sk_shutdown & SEND_SHUTDOWN) {
1571 				mask |= EPOLLOUT | EPOLLWRNORM;
1572 			} else {
1573 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1574 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1575 			}
1576 			if (atomic_read(&smc->conn.bytes_to_rcv))
1577 				mask |= EPOLLIN | EPOLLRDNORM;
1578 			if (sk->sk_shutdown & RCV_SHUTDOWN)
1579 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
1580 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
1581 				mask |= EPOLLIN;
1582 			if (smc->conn.urg_state == SMC_URG_VALID)
1583 				mask |= EPOLLPRI;
1584 		}
1585 	}
1586 
1587 	return mask;
1588 }
1589 
1590 static int smc_shutdown(struct socket *sock, int how)
1591 {
1592 	struct sock *sk = sock->sk;
1593 	struct smc_sock *smc;
1594 	int rc = -EINVAL;
1595 	int rc1 = 0;
1596 
1597 	smc = smc_sk(sk);
1598 
1599 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
1600 		return rc;
1601 
1602 	lock_sock(sk);
1603 
1604 	rc = -ENOTCONN;
1605 	if ((sk->sk_state != SMC_ACTIVE) &&
1606 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
1607 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
1608 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1609 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
1610 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
1611 		goto out;
1612 	if (smc->use_fallback) {
1613 		rc = kernel_sock_shutdown(smc->clcsock, how);
1614 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
1615 		if (sk->sk_shutdown == SHUTDOWN_MASK)
1616 			sk->sk_state = SMC_CLOSED;
1617 		goto out;
1618 	}
1619 	switch (how) {
1620 	case SHUT_RDWR:		/* shutdown in both directions */
1621 		rc = smc_close_active(smc);
1622 		break;
1623 	case SHUT_WR:
1624 		rc = smc_close_shutdown_write(smc);
1625 		break;
1626 	case SHUT_RD:
1627 		rc = 0;
1628 		/* nothing more to do because peer is not involved */
1629 		break;
1630 	}
1631 	if (smc->clcsock)
1632 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
1633 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
1634 	sk->sk_shutdown |= how + 1;
1635 
1636 out:
1637 	release_sock(sk);
1638 	return rc ? rc : rc1;
1639 }
1640 
1641 static int smc_setsockopt(struct socket *sock, int level, int optname,
1642 			  char __user *optval, unsigned int optlen)
1643 {
1644 	struct sock *sk = sock->sk;
1645 	struct smc_sock *smc;
1646 	int val, rc;
1647 
1648 	smc = smc_sk(sk);
1649 
1650 	/* generic setsockopts reaching us here always apply to the
1651 	 * CLC socket
1652 	 */
1653 	rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
1654 					   optval, optlen);
1655 	if (smc->clcsock->sk->sk_err) {
1656 		sk->sk_err = smc->clcsock->sk->sk_err;
1657 		sk->sk_error_report(sk);
1658 	}
1659 	if (rc)
1660 		return rc;
1661 
1662 	if (optlen < sizeof(int))
1663 		return -EINVAL;
1664 	if (get_user(val, (int __user *)optval))
1665 		return -EFAULT;
1666 
1667 	lock_sock(sk);
1668 	switch (optname) {
1669 	case TCP_ULP:
1670 	case TCP_FASTOPEN:
1671 	case TCP_FASTOPEN_CONNECT:
1672 	case TCP_FASTOPEN_KEY:
1673 	case TCP_FASTOPEN_NO_COOKIE:
1674 		/* option not supported by SMC */
1675 		if (sk->sk_state == SMC_INIT) {
1676 			smc->use_fallback = true;
1677 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1678 		} else {
1679 			if (!smc->use_fallback)
1680 				rc = -EINVAL;
1681 		}
1682 		break;
1683 	case TCP_NODELAY:
1684 		if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1685 			if (val && !smc->use_fallback)
1686 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1687 						 0);
1688 		}
1689 		break;
1690 	case TCP_CORK:
1691 		if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1692 			if (!val && !smc->use_fallback)
1693 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1694 						 0);
1695 		}
1696 		break;
1697 	case TCP_DEFER_ACCEPT:
1698 		smc->sockopt_defer_accept = val;
1699 		break;
1700 	default:
1701 		break;
1702 	}
1703 	release_sock(sk);
1704 
1705 	return rc;
1706 }
1707 
1708 static int smc_getsockopt(struct socket *sock, int level, int optname,
1709 			  char __user *optval, int __user *optlen)
1710 {
1711 	struct smc_sock *smc;
1712 
1713 	smc = smc_sk(sock->sk);
1714 	/* socket options apply to the CLC socket */
1715 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
1716 					     optval, optlen);
1717 }
1718 
1719 static int smc_ioctl(struct socket *sock, unsigned int cmd,
1720 		     unsigned long arg)
1721 {
1722 	union smc_host_cursor cons, urg;
1723 	struct smc_connection *conn;
1724 	struct smc_sock *smc;
1725 	int answ;
1726 
1727 	smc = smc_sk(sock->sk);
1728 	conn = &smc->conn;
1729 	lock_sock(&smc->sk);
1730 	if (smc->use_fallback) {
1731 		if (!smc->clcsock) {
1732 			release_sock(&smc->sk);
1733 			return -EBADF;
1734 		}
1735 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
1736 		release_sock(&smc->sk);
1737 		return answ;
1738 	}
1739 	switch (cmd) {
1740 	case SIOCINQ: /* same as FIONREAD */
1741 		if (smc->sk.sk_state == SMC_LISTEN) {
1742 			release_sock(&smc->sk);
1743 			return -EINVAL;
1744 		}
1745 		if (smc->sk.sk_state == SMC_INIT ||
1746 		    smc->sk.sk_state == SMC_CLOSED)
1747 			answ = 0;
1748 		else
1749 			answ = atomic_read(&smc->conn.bytes_to_rcv);
1750 		break;
1751 	case SIOCOUTQ:
1752 		/* output queue size (not send + not acked) */
1753 		if (smc->sk.sk_state == SMC_LISTEN) {
1754 			release_sock(&smc->sk);
1755 			return -EINVAL;
1756 		}
1757 		if (smc->sk.sk_state == SMC_INIT ||
1758 		    smc->sk.sk_state == SMC_CLOSED)
1759 			answ = 0;
1760 		else
1761 			answ = smc->conn.sndbuf_desc->len -
1762 					atomic_read(&smc->conn.sndbuf_space);
1763 		break;
1764 	case SIOCOUTQNSD:
1765 		/* output queue size (not send only) */
1766 		if (smc->sk.sk_state == SMC_LISTEN) {
1767 			release_sock(&smc->sk);
1768 			return -EINVAL;
1769 		}
1770 		if (smc->sk.sk_state == SMC_INIT ||
1771 		    smc->sk.sk_state == SMC_CLOSED)
1772 			answ = 0;
1773 		else
1774 			answ = smc_tx_prepared_sends(&smc->conn);
1775 		break;
1776 	case SIOCATMARK:
1777 		if (smc->sk.sk_state == SMC_LISTEN) {
1778 			release_sock(&smc->sk);
1779 			return -EINVAL;
1780 		}
1781 		if (smc->sk.sk_state == SMC_INIT ||
1782 		    smc->sk.sk_state == SMC_CLOSED) {
1783 			answ = 0;
1784 		} else {
1785 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
1786 			smc_curs_copy(&urg, &conn->urg_curs, conn);
1787 			answ = smc_curs_diff(conn->rmb_desc->len,
1788 					     &cons, &urg) == 1;
1789 		}
1790 		break;
1791 	default:
1792 		release_sock(&smc->sk);
1793 		return -ENOIOCTLCMD;
1794 	}
1795 	release_sock(&smc->sk);
1796 
1797 	return put_user(answ, (int __user *)arg);
1798 }
1799 
1800 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
1801 			    int offset, size_t size, int flags)
1802 {
1803 	struct sock *sk = sock->sk;
1804 	struct smc_sock *smc;
1805 	int rc = -EPIPE;
1806 
1807 	smc = smc_sk(sk);
1808 	lock_sock(sk);
1809 	if (sk->sk_state != SMC_ACTIVE) {
1810 		release_sock(sk);
1811 		goto out;
1812 	}
1813 	release_sock(sk);
1814 	if (smc->use_fallback)
1815 		rc = kernel_sendpage(smc->clcsock, page, offset,
1816 				     size, flags);
1817 	else
1818 		rc = sock_no_sendpage(sock, page, offset, size, flags);
1819 
1820 out:
1821 	return rc;
1822 }
1823 
1824 /* Map the affected portions of the rmbe into an spd, note the number of bytes
1825  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
1826  * updates till whenever a respective page has been fully processed.
1827  * Note that subsequent recv() calls have to wait till all splice() processing
1828  * completed.
1829  */
1830 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
1831 			       struct pipe_inode_info *pipe, size_t len,
1832 			       unsigned int flags)
1833 {
1834 	struct sock *sk = sock->sk;
1835 	struct smc_sock *smc;
1836 	int rc = -ENOTCONN;
1837 
1838 	smc = smc_sk(sk);
1839 	lock_sock(sk);
1840 
1841 	if (sk->sk_state == SMC_INIT ||
1842 	    sk->sk_state == SMC_LISTEN ||
1843 	    sk->sk_state == SMC_CLOSED)
1844 		goto out;
1845 
1846 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1847 		rc = 0;
1848 		goto out;
1849 	}
1850 
1851 	if (smc->use_fallback) {
1852 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
1853 						    pipe, len, flags);
1854 	} else {
1855 		if (*ppos) {
1856 			rc = -ESPIPE;
1857 			goto out;
1858 		}
1859 		if (flags & SPLICE_F_NONBLOCK)
1860 			flags = MSG_DONTWAIT;
1861 		else
1862 			flags = 0;
1863 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
1864 	}
1865 out:
1866 	release_sock(sk);
1867 
1868 	return rc;
1869 }
1870 
1871 /* must look like tcp */
1872 static const struct proto_ops smc_sock_ops = {
1873 	.family		= PF_SMC,
1874 	.owner		= THIS_MODULE,
1875 	.release	= smc_release,
1876 	.bind		= smc_bind,
1877 	.connect	= smc_connect,
1878 	.socketpair	= sock_no_socketpair,
1879 	.accept		= smc_accept,
1880 	.getname	= smc_getname,
1881 	.poll		= smc_poll,
1882 	.ioctl		= smc_ioctl,
1883 	.listen		= smc_listen,
1884 	.shutdown	= smc_shutdown,
1885 	.setsockopt	= smc_setsockopt,
1886 	.getsockopt	= smc_getsockopt,
1887 	.sendmsg	= smc_sendmsg,
1888 	.recvmsg	= smc_recvmsg,
1889 	.mmap		= sock_no_mmap,
1890 	.sendpage	= smc_sendpage,
1891 	.splice_read	= smc_splice_read,
1892 };
1893 
1894 static int smc_create(struct net *net, struct socket *sock, int protocol,
1895 		      int kern)
1896 {
1897 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
1898 	struct smc_sock *smc;
1899 	struct sock *sk;
1900 	int rc;
1901 
1902 	rc = -ESOCKTNOSUPPORT;
1903 	if (sock->type != SOCK_STREAM)
1904 		goto out;
1905 
1906 	rc = -EPROTONOSUPPORT;
1907 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
1908 		goto out;
1909 
1910 	rc = -ENOBUFS;
1911 	sock->ops = &smc_sock_ops;
1912 	sk = smc_sock_alloc(net, sock, protocol);
1913 	if (!sk)
1914 		goto out;
1915 
1916 	/* create internal TCP socket for CLC handshake and fallback */
1917 	smc = smc_sk(sk);
1918 	smc->use_fallback = false; /* assume rdma capability first */
1919 	smc->fallback_rsn = 0;
1920 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
1921 			      &smc->clcsock);
1922 	if (rc) {
1923 		sk_common_release(sk);
1924 		goto out;
1925 	}
1926 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
1927 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
1928 
1929 out:
1930 	return rc;
1931 }
1932 
1933 static const struct net_proto_family smc_sock_family_ops = {
1934 	.family	= PF_SMC,
1935 	.owner	= THIS_MODULE,
1936 	.create	= smc_create,
1937 };
1938 
1939 static int __init smc_init(void)
1940 {
1941 	int rc;
1942 
1943 	rc = smc_pnet_init();
1944 	if (rc)
1945 		return rc;
1946 
1947 	rc = smc_llc_init();
1948 	if (rc) {
1949 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
1950 		goto out_pnet;
1951 	}
1952 
1953 	rc = smc_cdc_init();
1954 	if (rc) {
1955 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
1956 		goto out_pnet;
1957 	}
1958 
1959 	rc = proto_register(&smc_proto, 1);
1960 	if (rc) {
1961 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
1962 		goto out_pnet;
1963 	}
1964 
1965 	rc = proto_register(&smc_proto6, 1);
1966 	if (rc) {
1967 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
1968 		goto out_proto;
1969 	}
1970 
1971 	rc = sock_register(&smc_sock_family_ops);
1972 	if (rc) {
1973 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
1974 		goto out_proto6;
1975 	}
1976 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
1977 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
1978 
1979 	rc = smc_ib_register_client();
1980 	if (rc) {
1981 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
1982 		goto out_sock;
1983 	}
1984 
1985 	static_branch_enable(&tcp_have_smc);
1986 	return 0;
1987 
1988 out_sock:
1989 	sock_unregister(PF_SMC);
1990 out_proto6:
1991 	proto_unregister(&smc_proto6);
1992 out_proto:
1993 	proto_unregister(&smc_proto);
1994 out_pnet:
1995 	smc_pnet_exit();
1996 	return rc;
1997 }
1998 
1999 static void __exit smc_exit(void)
2000 {
2001 	smc_core_exit();
2002 	static_branch_disable(&tcp_have_smc);
2003 	smc_ib_unregister_client();
2004 	sock_unregister(PF_SMC);
2005 	proto_unregister(&smc_proto6);
2006 	proto_unregister(&smc_proto);
2007 	smc_pnet_exit();
2008 }
2009 
2010 module_init(smc_init);
2011 module_exit(smc_exit);
2012 
2013 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
2014 MODULE_DESCRIPTION("smc socket address family");
2015 MODULE_LICENSE("GPL");
2016 MODULE_ALIAS_NETPROTO(PF_SMC);
2017