xref: /linux/net/smc/af_smc.c (revision cad4977344b35ea116ec5fefe91a76b1dfa113f5)
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 		sock_release(smc->clcsock);
151 		smc->clcsock = NULL;
152 	}
153 	if (smc->use_fallback) {
154 		if (sk->sk_state != SMC_LISTEN && sk->sk_state != SMC_INIT)
155 			sock_put(sk); /* passive closing */
156 		sk->sk_state = SMC_CLOSED;
157 		sk->sk_state_change(sk);
158 	}
159 
160 	/* detach socket */
161 	sock_orphan(sk);
162 	sock->sk = NULL;
163 	if (!smc->use_fallback && sk->sk_state == SMC_CLOSED)
164 		smc_conn_free(&smc->conn);
165 	release_sock(sk);
166 
167 	sk->sk_prot->unhash(sk);
168 	sock_put(sk); /* final sock_put */
169 out:
170 	return rc;
171 }
172 
173 static void smc_destruct(struct sock *sk)
174 {
175 	if (sk->sk_state != SMC_CLOSED)
176 		return;
177 	if (!sock_flag(sk, SOCK_DEAD))
178 		return;
179 
180 	sk_refcnt_debug_dec(sk);
181 }
182 
183 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
184 				   int protocol)
185 {
186 	struct smc_sock *smc;
187 	struct proto *prot;
188 	struct sock *sk;
189 
190 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
191 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
192 	if (!sk)
193 		return NULL;
194 
195 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
196 	sk->sk_state = SMC_INIT;
197 	sk->sk_destruct = smc_destruct;
198 	sk->sk_protocol = protocol;
199 	smc = smc_sk(sk);
200 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
201 	INIT_WORK(&smc->connect_work, smc_connect_work);
202 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
203 	INIT_LIST_HEAD(&smc->accept_q);
204 	spin_lock_init(&smc->accept_q_lock);
205 	spin_lock_init(&smc->conn.send_lock);
206 	sk->sk_prot->hash(sk);
207 	sk_refcnt_debug_inc(sk);
208 
209 	return sk;
210 }
211 
212 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
213 		    int addr_len)
214 {
215 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
216 	struct sock *sk = sock->sk;
217 	struct smc_sock *smc;
218 	int rc;
219 
220 	smc = smc_sk(sk);
221 
222 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
223 	rc = -EINVAL;
224 	if (addr_len < sizeof(struct sockaddr_in))
225 		goto out;
226 
227 	rc = -EAFNOSUPPORT;
228 	if (addr->sin_family != AF_INET &&
229 	    addr->sin_family != AF_INET6 &&
230 	    addr->sin_family != AF_UNSPEC)
231 		goto out;
232 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
233 	if (addr->sin_family == AF_UNSPEC &&
234 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
235 		goto out;
236 
237 	lock_sock(sk);
238 
239 	/* Check if socket is already active */
240 	rc = -EINVAL;
241 	if (sk->sk_state != SMC_INIT)
242 		goto out_rel;
243 
244 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
245 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
246 
247 out_rel:
248 	release_sock(sk);
249 out:
250 	return rc;
251 }
252 
253 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
254 				   unsigned long mask)
255 {
256 	/* options we don't get control via setsockopt for */
257 	nsk->sk_type = osk->sk_type;
258 	nsk->sk_sndbuf = osk->sk_sndbuf;
259 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
260 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
261 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
262 	nsk->sk_mark = osk->sk_mark;
263 	nsk->sk_priority = osk->sk_priority;
264 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
265 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
266 	nsk->sk_err = osk->sk_err;
267 
268 	nsk->sk_flags &= ~mask;
269 	nsk->sk_flags |= osk->sk_flags & mask;
270 }
271 
272 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
273 			     (1UL << SOCK_KEEPOPEN) | \
274 			     (1UL << SOCK_LINGER) | \
275 			     (1UL << SOCK_BROADCAST) | \
276 			     (1UL << SOCK_TIMESTAMP) | \
277 			     (1UL << SOCK_DBG) | \
278 			     (1UL << SOCK_RCVTSTAMP) | \
279 			     (1UL << SOCK_RCVTSTAMPNS) | \
280 			     (1UL << SOCK_LOCALROUTE) | \
281 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
282 			     (1UL << SOCK_RXQ_OVFL) | \
283 			     (1UL << SOCK_WIFI_STATUS) | \
284 			     (1UL << SOCK_NOFCS) | \
285 			     (1UL << SOCK_FILTER_LOCKED))
286 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
287  * clc socket (since smc is not called for these options from net/core)
288  */
289 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
290 {
291 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
292 }
293 
294 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
295 			     (1UL << SOCK_KEEPOPEN) | \
296 			     (1UL << SOCK_LINGER) | \
297 			     (1UL << SOCK_DBG))
298 /* copy only settings and flags relevant for smc from clc to smc socket */
299 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
300 {
301 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
302 }
303 
304 /* register a new rmb, send confirm_rkey msg to register with peer */
305 static int smc_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc,
306 		       bool conf_rkey)
307 {
308 	if (!rmb_desc->wr_reg) {
309 		/* register memory region for new rmb */
310 		if (smc_wr_reg_send(link, rmb_desc->mr_rx[SMC_SINGLE_LINK])) {
311 			rmb_desc->regerr = 1;
312 			return -EFAULT;
313 		}
314 		rmb_desc->wr_reg = 1;
315 	}
316 	if (!conf_rkey)
317 		return 0;
318 	/* exchange confirm_rkey msg with peer */
319 	if (smc_llc_do_confirm_rkey(link, rmb_desc)) {
320 		rmb_desc->regerr = 1;
321 		return -EFAULT;
322 	}
323 	return 0;
324 }
325 
326 static int smc_clnt_conf_first_link(struct smc_sock *smc)
327 {
328 	struct net *net = sock_net(smc->clcsock->sk);
329 	struct smc_link_group *lgr = smc->conn.lgr;
330 	struct smc_link *link;
331 	int rest;
332 	int rc;
333 
334 	link = &lgr->lnk[SMC_SINGLE_LINK];
335 	/* receive CONFIRM LINK request from server over RoCE fabric */
336 	rest = wait_for_completion_interruptible_timeout(
337 		&link->llc_confirm,
338 		SMC_LLC_WAIT_FIRST_TIME);
339 	if (rest <= 0) {
340 		struct smc_clc_msg_decline dclc;
341 
342 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
343 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
344 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
345 	}
346 
347 	if (link->llc_confirm_rc)
348 		return SMC_CLC_DECL_RMBE_EC;
349 
350 	rc = smc_ib_modify_qp_rts(link);
351 	if (rc)
352 		return SMC_CLC_DECL_ERR_RDYLNK;
353 
354 	smc_wr_remember_qp_attr(link);
355 
356 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
357 		return SMC_CLC_DECL_ERR_REGRMB;
358 
359 	/* send CONFIRM LINK response over RoCE fabric */
360 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
361 	if (rc < 0)
362 		return SMC_CLC_DECL_TIMEOUT_CL;
363 
364 	/* receive ADD LINK request from server over RoCE fabric */
365 	rest = wait_for_completion_interruptible_timeout(&link->llc_add,
366 							 SMC_LLC_WAIT_TIME);
367 	if (rest <= 0) {
368 		struct smc_clc_msg_decline dclc;
369 
370 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
371 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
372 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_AL : rc;
373 	}
374 
375 	/* send add link reject message, only one link supported for now */
376 	rc = smc_llc_send_add_link(link,
377 				   link->smcibdev->mac[link->ibport - 1],
378 				   link->gid, SMC_LLC_RESP);
379 	if (rc < 0)
380 		return SMC_CLC_DECL_TIMEOUT_AL;
381 
382 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
383 
384 	return 0;
385 }
386 
387 static void smcr_conn_save_peer_info(struct smc_sock *smc,
388 				     struct smc_clc_msg_accept_confirm *clc)
389 {
390 	int bufsize = smc_uncompress_bufsize(clc->rmbe_size);
391 
392 	smc->conn.peer_rmbe_idx = clc->rmbe_idx;
393 	smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
394 	smc->conn.peer_rmbe_size = bufsize;
395 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
396 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
397 }
398 
399 static void smcd_conn_save_peer_info(struct smc_sock *smc,
400 				     struct smc_clc_msg_accept_confirm *clc)
401 {
402 	int bufsize = smc_uncompress_bufsize(clc->dmbe_size);
403 
404 	smc->conn.peer_rmbe_idx = clc->dmbe_idx;
405 	smc->conn.peer_token = clc->token;
406 	/* msg header takes up space in the buffer */
407 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
408 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
409 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
410 }
411 
412 static void smc_conn_save_peer_info(struct smc_sock *smc,
413 				    struct smc_clc_msg_accept_confirm *clc)
414 {
415 	if (smc->conn.lgr->is_smcd)
416 		smcd_conn_save_peer_info(smc, clc);
417 	else
418 		smcr_conn_save_peer_info(smc, clc);
419 }
420 
421 static void smc_link_save_peer_info(struct smc_link *link,
422 				    struct smc_clc_msg_accept_confirm *clc)
423 {
424 	link->peer_qpn = ntoh24(clc->qpn);
425 	memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
426 	memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
427 	link->peer_psn = ntoh24(clc->psn);
428 	link->peer_mtu = clc->qp_mtu;
429 }
430 
431 /* fall back during connect */
432 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
433 {
434 	smc->use_fallback = true;
435 	smc->fallback_rsn = reason_code;
436 	smc_copy_sock_settings_to_clc(smc);
437 	if (smc->sk.sk_state == SMC_INIT)
438 		smc->sk.sk_state = SMC_ACTIVE;
439 	return 0;
440 }
441 
442 /* decline and fall back during connect */
443 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code)
444 {
445 	int rc;
446 
447 	if (reason_code < 0) { /* error, fallback is not possible */
448 		if (smc->sk.sk_state == SMC_INIT)
449 			sock_put(&smc->sk); /* passive closing */
450 		return reason_code;
451 	}
452 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
453 		rc = smc_clc_send_decline(smc, reason_code);
454 		if (rc < 0) {
455 			if (smc->sk.sk_state == SMC_INIT)
456 				sock_put(&smc->sk); /* passive closing */
457 			return rc;
458 		}
459 	}
460 	return smc_connect_fallback(smc, reason_code);
461 }
462 
463 /* abort connecting */
464 static int smc_connect_abort(struct smc_sock *smc, int reason_code,
465 			     int local_contact)
466 {
467 	if (local_contact == SMC_FIRST_CONTACT)
468 		smc_lgr_forget(smc->conn.lgr);
469 	mutex_unlock(&smc_create_lgr_pending);
470 	smc_conn_free(&smc->conn);
471 	return reason_code;
472 }
473 
474 /* check if there is a rdma device available for this connection. */
475 /* called for connect and listen */
476 static int smc_check_rdma(struct smc_sock *smc, struct smc_ib_device **ibdev,
477 			  u8 *ibport, unsigned short vlan_id, u8 gid[])
478 {
479 	int reason_code = 0;
480 
481 	/* PNET table look up: search active ib_device and port
482 	 * within same PNETID that also contains the ethernet device
483 	 * used for the internal TCP socket
484 	 */
485 	smc_pnet_find_roce_resource(smc->clcsock->sk, ibdev, ibport, vlan_id,
486 				    gid);
487 	if (!(*ibdev))
488 		reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
489 
490 	return reason_code;
491 }
492 
493 /* check if there is an ISM device available for this connection. */
494 /* called for connect and listen */
495 static int smc_check_ism(struct smc_sock *smc, struct smcd_dev **ismdev)
496 {
497 	/* Find ISM device with same PNETID as connecting interface  */
498 	smc_pnet_find_ism_resource(smc->clcsock->sk, ismdev);
499 	if (!(*ismdev))
500 		return SMC_CLC_DECL_CNFERR; /* configuration error */
501 	return 0;
502 }
503 
504 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
505 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
506 				      struct smcd_dev *ismdev,
507 				      unsigned short vlan_id)
508 {
509 	if (vlan_id && smc_ism_get_vlan(ismdev, vlan_id))
510 		return SMC_CLC_DECL_CNFERR;
511 	return 0;
512 }
513 
514 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
515  * used, the VLAN ID will be registered again during the connection setup.
516  */
517 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc, bool is_smcd,
518 					struct smcd_dev *ismdev,
519 					unsigned short vlan_id)
520 {
521 	if (!is_smcd)
522 		return 0;
523 	if (vlan_id && smc_ism_put_vlan(ismdev, vlan_id))
524 		return SMC_CLC_DECL_CNFERR;
525 	return 0;
526 }
527 
528 /* CLC handshake during connect */
529 static int smc_connect_clc(struct smc_sock *smc, int smc_type,
530 			   struct smc_clc_msg_accept_confirm *aclc,
531 			   struct smc_ib_device *ibdev, u8 ibport,
532 			   u8 gid[], struct smcd_dev *ismdev)
533 {
534 	int rc = 0;
535 
536 	/* do inband token exchange */
537 	rc = smc_clc_send_proposal(smc, smc_type, ibdev, ibport, gid, ismdev);
538 	if (rc)
539 		return rc;
540 	/* receive SMC Accept CLC message */
541 	return smc_clc_wait_msg(smc, aclc, sizeof(*aclc), SMC_CLC_ACCEPT,
542 				CLC_WAIT_TIME);
543 }
544 
545 /* setup for RDMA connection of client */
546 static int smc_connect_rdma(struct smc_sock *smc,
547 			    struct smc_clc_msg_accept_confirm *aclc,
548 			    struct smc_ib_device *ibdev, u8 ibport)
549 {
550 	int local_contact = SMC_FIRST_CONTACT;
551 	struct smc_link *link;
552 	int reason_code = 0;
553 
554 	mutex_lock(&smc_create_lgr_pending);
555 	local_contact = smc_conn_create(smc, false, aclc->hdr.flag, ibdev,
556 					ibport, ntoh24(aclc->qpn), &aclc->lcl,
557 					NULL, 0);
558 	if (local_contact < 0) {
559 		if (local_contact == -ENOMEM)
560 			reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
561 		else if (local_contact == -ENOLINK)
562 			reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
563 		else
564 			reason_code = SMC_CLC_DECL_INTERR; /* other error */
565 		return smc_connect_abort(smc, reason_code, 0);
566 	}
567 	link = &smc->conn.lgr->lnk[SMC_SINGLE_LINK];
568 
569 	smc_conn_save_peer_info(smc, aclc);
570 
571 	/* create send buffer and rmb */
572 	if (smc_buf_create(smc, false))
573 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM, local_contact);
574 
575 	if (local_contact == SMC_FIRST_CONTACT)
576 		smc_link_save_peer_info(link, aclc);
577 
578 	if (smc_rmb_rtoken_handling(&smc->conn, aclc))
579 		return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RTOK,
580 					 local_contact);
581 
582 	smc_close_init(smc);
583 	smc_rx_init(smc);
584 
585 	if (local_contact == SMC_FIRST_CONTACT) {
586 		if (smc_ib_ready_link(link))
587 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RDYLNK,
588 						 local_contact);
589 	} else {
590 		if (smc_reg_rmb(link, smc->conn.rmb_desc, true))
591 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_REGRMB,
592 						 local_contact);
593 	}
594 	smc_rmb_sync_sg_for_device(&smc->conn);
595 
596 	reason_code = smc_clc_send_confirm(smc);
597 	if (reason_code)
598 		return smc_connect_abort(smc, reason_code, local_contact);
599 
600 	smc_tx_init(smc);
601 
602 	if (local_contact == SMC_FIRST_CONTACT) {
603 		/* QP confirmation over RoCE fabric */
604 		reason_code = smc_clnt_conf_first_link(smc);
605 		if (reason_code)
606 			return smc_connect_abort(smc, reason_code,
607 						 local_contact);
608 	}
609 	mutex_unlock(&smc_create_lgr_pending);
610 
611 	smc_copy_sock_settings_to_clc(smc);
612 	if (smc->sk.sk_state == SMC_INIT)
613 		smc->sk.sk_state = SMC_ACTIVE;
614 
615 	return 0;
616 }
617 
618 /* setup for ISM connection of client */
619 static int smc_connect_ism(struct smc_sock *smc,
620 			   struct smc_clc_msg_accept_confirm *aclc,
621 			   struct smcd_dev *ismdev)
622 {
623 	int local_contact = SMC_FIRST_CONTACT;
624 	int rc = 0;
625 
626 	mutex_lock(&smc_create_lgr_pending);
627 	local_contact = smc_conn_create(smc, true, aclc->hdr.flag, NULL, 0, 0,
628 					NULL, ismdev, aclc->gid);
629 	if (local_contact < 0)
630 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM, 0);
631 
632 	/* Create send and receive buffers */
633 	if (smc_buf_create(smc, true))
634 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM, local_contact);
635 
636 	smc_conn_save_peer_info(smc, aclc);
637 	smc_close_init(smc);
638 	smc_rx_init(smc);
639 	smc_tx_init(smc);
640 
641 	rc = smc_clc_send_confirm(smc);
642 	if (rc)
643 		return smc_connect_abort(smc, rc, local_contact);
644 	mutex_unlock(&smc_create_lgr_pending);
645 
646 	smc_copy_sock_settings_to_clc(smc);
647 	if (smc->sk.sk_state == SMC_INIT)
648 		smc->sk.sk_state = SMC_ACTIVE;
649 
650 	return 0;
651 }
652 
653 /* perform steps before actually connecting */
654 static int __smc_connect(struct smc_sock *smc)
655 {
656 	bool ism_supported = false, rdma_supported = false;
657 	struct smc_clc_msg_accept_confirm aclc;
658 	struct smc_ib_device *ibdev;
659 	struct smcd_dev *ismdev;
660 	u8 gid[SMC_GID_SIZE];
661 	unsigned short vlan;
662 	int smc_type;
663 	int rc = 0;
664 	u8 ibport;
665 
666 	sock_hold(&smc->sk); /* sock put in passive closing */
667 
668 	if (smc->use_fallback)
669 		return smc_connect_fallback(smc, smc->fallback_rsn);
670 
671 	/* if peer has not signalled SMC-capability, fall back */
672 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
673 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
674 
675 	/* IPSec connections opt out of SMC-R optimizations */
676 	if (using_ipsec(smc))
677 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC);
678 
679 	/* check for VLAN ID */
680 	if (smc_vlan_by_tcpsk(smc->clcsock, &vlan))
681 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_CNFERR);
682 
683 	/* check if there is an ism device available */
684 	if (!smc_check_ism(smc, &ismdev) &&
685 	    !smc_connect_ism_vlan_setup(smc, ismdev, vlan)) {
686 		/* ISM is supported for this connection */
687 		ism_supported = true;
688 		smc_type = SMC_TYPE_D;
689 	}
690 
691 	/* check if there is a rdma device available */
692 	if (!smc_check_rdma(smc, &ibdev, &ibport, vlan, gid)) {
693 		/* RDMA is supported for this connection */
694 		rdma_supported = true;
695 		if (ism_supported)
696 			smc_type = SMC_TYPE_B; /* both */
697 		else
698 			smc_type = SMC_TYPE_R; /* only RDMA */
699 	}
700 
701 	/* if neither ISM nor RDMA are supported, fallback */
702 	if (!rdma_supported && !ism_supported)
703 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_NOSMCDEV);
704 
705 	/* perform CLC handshake */
706 	rc = smc_connect_clc(smc, smc_type, &aclc, ibdev, ibport, gid, ismdev);
707 	if (rc) {
708 		smc_connect_ism_vlan_cleanup(smc, ism_supported, ismdev, vlan);
709 		return smc_connect_decline_fallback(smc, rc);
710 	}
711 
712 	/* depending on previous steps, connect using rdma or ism */
713 	if (rdma_supported && aclc.hdr.path == SMC_TYPE_R)
714 		rc = smc_connect_rdma(smc, &aclc, ibdev, ibport);
715 	else if (ism_supported && aclc.hdr.path == SMC_TYPE_D)
716 		rc = smc_connect_ism(smc, &aclc, ismdev);
717 	else
718 		rc = SMC_CLC_DECL_MODEUNSUPP;
719 	if (rc) {
720 		smc_connect_ism_vlan_cleanup(smc, ism_supported, ismdev, vlan);
721 		return smc_connect_decline_fallback(smc, rc);
722 	}
723 
724 	smc_connect_ism_vlan_cleanup(smc, ism_supported, ismdev, vlan);
725 	return 0;
726 }
727 
728 static void smc_connect_work(struct work_struct *work)
729 {
730 	struct smc_sock *smc = container_of(work, struct smc_sock,
731 					    connect_work);
732 	int rc;
733 
734 	lock_sock(&smc->sk);
735 	rc = kernel_connect(smc->clcsock, &smc->connect_info->addr,
736 			    smc->connect_info->alen, smc->connect_info->flags);
737 	if (smc->clcsock->sk->sk_err) {
738 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
739 		goto out;
740 	}
741 	if (rc < 0) {
742 		smc->sk.sk_err = -rc;
743 		goto out;
744 	}
745 
746 	rc = __smc_connect(smc);
747 	if (rc < 0)
748 		smc->sk.sk_err = -rc;
749 
750 out:
751 	if (smc->sk.sk_err)
752 		smc->sk.sk_state_change(&smc->sk);
753 	else
754 		smc->sk.sk_write_space(&smc->sk);
755 	kfree(smc->connect_info);
756 	smc->connect_info = NULL;
757 	release_sock(&smc->sk);
758 }
759 
760 static int smc_connect(struct socket *sock, struct sockaddr *addr,
761 		       int alen, int flags)
762 {
763 	struct sock *sk = sock->sk;
764 	struct smc_sock *smc;
765 	int rc = -EINVAL;
766 
767 	smc = smc_sk(sk);
768 
769 	/* separate smc parameter checking to be safe */
770 	if (alen < sizeof(addr->sa_family))
771 		goto out_err;
772 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
773 		goto out_err;
774 
775 	lock_sock(sk);
776 	switch (sk->sk_state) {
777 	default:
778 		goto out;
779 	case SMC_ACTIVE:
780 		rc = -EISCONN;
781 		goto out;
782 	case SMC_INIT:
783 		rc = 0;
784 		break;
785 	}
786 
787 	smc_copy_sock_settings_to_clc(smc);
788 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
789 	if (flags & O_NONBLOCK) {
790 		if (smc->connect_info) {
791 			rc = -EALREADY;
792 			goto out;
793 		}
794 		smc->connect_info = kzalloc(alen + 2 * sizeof(int), GFP_KERNEL);
795 		if (!smc->connect_info) {
796 			rc = -ENOMEM;
797 			goto out;
798 		}
799 		smc->connect_info->alen = alen;
800 		smc->connect_info->flags = flags ^ O_NONBLOCK;
801 		memcpy(&smc->connect_info->addr, addr, alen);
802 		schedule_work(&smc->connect_work);
803 		rc = -EINPROGRESS;
804 	} else {
805 		rc = kernel_connect(smc->clcsock, addr, alen, flags);
806 		if (rc)
807 			goto out;
808 
809 		rc = __smc_connect(smc);
810 		if (rc < 0)
811 			goto out;
812 		else
813 			rc = 0; /* success cases including fallback */
814 	}
815 
816 out:
817 	release_sock(sk);
818 out_err:
819 	return rc;
820 }
821 
822 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
823 {
824 	struct socket *new_clcsock = NULL;
825 	struct sock *lsk = &lsmc->sk;
826 	struct sock *new_sk;
827 	int rc;
828 
829 	release_sock(lsk);
830 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
831 	if (!new_sk) {
832 		rc = -ENOMEM;
833 		lsk->sk_err = ENOMEM;
834 		*new_smc = NULL;
835 		lock_sock(lsk);
836 		goto out;
837 	}
838 	*new_smc = smc_sk(new_sk);
839 
840 	rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
841 	lock_sock(lsk);
842 	if  (rc < 0)
843 		lsk->sk_err = -rc;
844 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
845 		if (new_clcsock)
846 			sock_release(new_clcsock);
847 		new_sk->sk_state = SMC_CLOSED;
848 		sock_set_flag(new_sk, SOCK_DEAD);
849 		new_sk->sk_prot->unhash(new_sk);
850 		sock_put(new_sk); /* final */
851 		*new_smc = NULL;
852 		goto out;
853 	}
854 
855 	(*new_smc)->clcsock = new_clcsock;
856 out:
857 	return rc;
858 }
859 
860 /* add a just created sock to the accept queue of the listen sock as
861  * candidate for a following socket accept call from user space
862  */
863 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
864 {
865 	struct smc_sock *par = smc_sk(parent);
866 
867 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
868 	spin_lock(&par->accept_q_lock);
869 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
870 	spin_unlock(&par->accept_q_lock);
871 	sk_acceptq_added(parent);
872 }
873 
874 /* remove a socket from the accept queue of its parental listening socket */
875 static void smc_accept_unlink(struct sock *sk)
876 {
877 	struct smc_sock *par = smc_sk(sk)->listen_smc;
878 
879 	spin_lock(&par->accept_q_lock);
880 	list_del_init(&smc_sk(sk)->accept_q);
881 	spin_unlock(&par->accept_q_lock);
882 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
883 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
884 }
885 
886 /* remove a sock from the accept queue to bind it to a new socket created
887  * for a socket accept call from user space
888  */
889 struct sock *smc_accept_dequeue(struct sock *parent,
890 				struct socket *new_sock)
891 {
892 	struct smc_sock *isk, *n;
893 	struct sock *new_sk;
894 
895 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
896 		new_sk = (struct sock *)isk;
897 
898 		smc_accept_unlink(new_sk);
899 		if (new_sk->sk_state == SMC_CLOSED) {
900 			if (isk->clcsock) {
901 				sock_release(isk->clcsock);
902 				isk->clcsock = NULL;
903 			}
904 			new_sk->sk_prot->unhash(new_sk);
905 			sock_put(new_sk); /* final */
906 			continue;
907 		}
908 		if (new_sock)
909 			sock_graft(new_sk, new_sock);
910 		return new_sk;
911 	}
912 	return NULL;
913 }
914 
915 /* clean up for a created but never accepted sock */
916 void smc_close_non_accepted(struct sock *sk)
917 {
918 	struct smc_sock *smc = smc_sk(sk);
919 
920 	lock_sock(sk);
921 	if (!sk->sk_lingertime)
922 		/* wait for peer closing */
923 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
924 	if (!smc->use_fallback) {
925 		smc_close_active(smc);
926 		sock_set_flag(sk, SOCK_DEAD);
927 		sk->sk_shutdown |= SHUTDOWN_MASK;
928 	}
929 	if (smc->clcsock) {
930 		struct socket *tcp;
931 
932 		tcp = smc->clcsock;
933 		smc->clcsock = NULL;
934 		sock_release(tcp);
935 	}
936 	if (smc->use_fallback) {
937 		sock_put(sk); /* passive closing */
938 		sk->sk_state = SMC_CLOSED;
939 	} else {
940 		if (sk->sk_state == SMC_CLOSED)
941 			smc_conn_free(&smc->conn);
942 	}
943 	release_sock(sk);
944 	sk->sk_prot->unhash(sk);
945 	sock_put(sk); /* final sock_put */
946 }
947 
948 static int smc_serv_conf_first_link(struct smc_sock *smc)
949 {
950 	struct net *net = sock_net(smc->clcsock->sk);
951 	struct smc_link_group *lgr = smc->conn.lgr;
952 	struct smc_link *link;
953 	int rest;
954 	int rc;
955 
956 	link = &lgr->lnk[SMC_SINGLE_LINK];
957 
958 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
959 		return SMC_CLC_DECL_ERR_REGRMB;
960 
961 	/* send CONFIRM LINK request to client over the RoCE fabric */
962 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
963 	if (rc < 0)
964 		return SMC_CLC_DECL_TIMEOUT_CL;
965 
966 	/* receive CONFIRM LINK response from client over the RoCE fabric */
967 	rest = wait_for_completion_interruptible_timeout(
968 		&link->llc_confirm_resp,
969 		SMC_LLC_WAIT_FIRST_TIME);
970 	if (rest <= 0) {
971 		struct smc_clc_msg_decline dclc;
972 
973 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
974 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
975 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
976 	}
977 
978 	if (link->llc_confirm_resp_rc)
979 		return SMC_CLC_DECL_RMBE_EC;
980 
981 	/* send ADD LINK request to client over the RoCE fabric */
982 	rc = smc_llc_send_add_link(link,
983 				   link->smcibdev->mac[link->ibport - 1],
984 				   link->gid, SMC_LLC_REQ);
985 	if (rc < 0)
986 		return SMC_CLC_DECL_TIMEOUT_AL;
987 
988 	/* receive ADD LINK response from client over the RoCE fabric */
989 	rest = wait_for_completion_interruptible_timeout(&link->llc_add_resp,
990 							 SMC_LLC_WAIT_TIME);
991 	if (rest <= 0) {
992 		struct smc_clc_msg_decline dclc;
993 
994 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
995 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
996 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_AL : rc;
997 	}
998 
999 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
1000 
1001 	return 0;
1002 }
1003 
1004 /* listen worker: finish */
1005 static void smc_listen_out(struct smc_sock *new_smc)
1006 {
1007 	struct smc_sock *lsmc = new_smc->listen_smc;
1008 	struct sock *newsmcsk = &new_smc->sk;
1009 
1010 	lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1011 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1012 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1013 	} else { /* no longer listening */
1014 		smc_close_non_accepted(newsmcsk);
1015 	}
1016 	release_sock(&lsmc->sk);
1017 
1018 	/* Wake up accept */
1019 	lsmc->sk.sk_data_ready(&lsmc->sk);
1020 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1021 }
1022 
1023 /* listen worker: finish in state connected */
1024 static void smc_listen_out_connected(struct smc_sock *new_smc)
1025 {
1026 	struct sock *newsmcsk = &new_smc->sk;
1027 
1028 	sk_refcnt_debug_inc(newsmcsk);
1029 	if (newsmcsk->sk_state == SMC_INIT)
1030 		newsmcsk->sk_state = SMC_ACTIVE;
1031 
1032 	smc_listen_out(new_smc);
1033 }
1034 
1035 /* listen worker: finish in error state */
1036 static void smc_listen_out_err(struct smc_sock *new_smc)
1037 {
1038 	struct sock *newsmcsk = &new_smc->sk;
1039 
1040 	if (newsmcsk->sk_state == SMC_INIT)
1041 		sock_put(&new_smc->sk); /* passive closing */
1042 	newsmcsk->sk_state = SMC_CLOSED;
1043 	smc_conn_free(&new_smc->conn);
1044 
1045 	smc_listen_out(new_smc);
1046 }
1047 
1048 /* listen worker: decline and fall back if possible */
1049 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1050 			       int local_contact)
1051 {
1052 	/* RDMA setup failed, switch back to TCP */
1053 	if (local_contact == SMC_FIRST_CONTACT)
1054 		smc_lgr_forget(new_smc->conn.lgr);
1055 	if (reason_code < 0) { /* error, no fallback possible */
1056 		smc_listen_out_err(new_smc);
1057 		return;
1058 	}
1059 	smc_conn_free(&new_smc->conn);
1060 	new_smc->use_fallback = true;
1061 	new_smc->fallback_rsn = reason_code;
1062 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1063 		if (smc_clc_send_decline(new_smc, reason_code) < 0) {
1064 			smc_listen_out_err(new_smc);
1065 			return;
1066 		}
1067 	}
1068 	smc_listen_out_connected(new_smc);
1069 }
1070 
1071 /* listen worker: check prefixes */
1072 static int smc_listen_rdma_check(struct smc_sock *new_smc,
1073 				 struct smc_clc_msg_proposal *pclc)
1074 {
1075 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1076 	struct socket *newclcsock = new_smc->clcsock;
1077 
1078 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1079 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1080 		return SMC_CLC_DECL_CNFERR;
1081 
1082 	return 0;
1083 }
1084 
1085 /* listen worker: initialize connection and buffers */
1086 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1087 				struct smc_clc_msg_proposal *pclc,
1088 				struct smc_ib_device *ibdev, u8 ibport,
1089 				int *local_contact)
1090 {
1091 	/* allocate connection / link group */
1092 	*local_contact = smc_conn_create(new_smc, false, 0, ibdev, ibport, 0,
1093 					 &pclc->lcl, NULL, 0);
1094 	if (*local_contact < 0) {
1095 		if (*local_contact == -ENOMEM)
1096 			return SMC_CLC_DECL_MEM;/* insufficient memory*/
1097 		return SMC_CLC_DECL_INTERR; /* other error */
1098 	}
1099 
1100 	/* create send buffer and rmb */
1101 	if (smc_buf_create(new_smc, false))
1102 		return SMC_CLC_DECL_MEM;
1103 
1104 	return 0;
1105 }
1106 
1107 /* listen worker: initialize connection and buffers for SMC-D */
1108 static int smc_listen_ism_init(struct smc_sock *new_smc,
1109 			       struct smc_clc_msg_proposal *pclc,
1110 			       struct smcd_dev *ismdev,
1111 			       int *local_contact)
1112 {
1113 	struct smc_clc_msg_smcd *pclc_smcd;
1114 
1115 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
1116 	*local_contact = smc_conn_create(new_smc, true, 0, NULL, 0, 0, NULL,
1117 					 ismdev, pclc_smcd->gid);
1118 	if (*local_contact < 0) {
1119 		if (*local_contact == -ENOMEM)
1120 			return SMC_CLC_DECL_MEM;/* insufficient memory*/
1121 		return SMC_CLC_DECL_INTERR; /* other error */
1122 	}
1123 
1124 	/* Check if peer can be reached via ISM device */
1125 	if (smc_ism_cantalk(new_smc->conn.lgr->peer_gid,
1126 			    new_smc->conn.lgr->vlan_id,
1127 			    new_smc->conn.lgr->smcd)) {
1128 		if (*local_contact == SMC_FIRST_CONTACT)
1129 			smc_lgr_forget(new_smc->conn.lgr);
1130 		smc_conn_free(&new_smc->conn);
1131 		return SMC_CLC_DECL_CNFERR;
1132 	}
1133 
1134 	/* Create send and receive buffers */
1135 	if (smc_buf_create(new_smc, true)) {
1136 		if (*local_contact == SMC_FIRST_CONTACT)
1137 			smc_lgr_forget(new_smc->conn.lgr);
1138 		smc_conn_free(&new_smc->conn);
1139 		return SMC_CLC_DECL_MEM;
1140 	}
1141 
1142 	return 0;
1143 }
1144 
1145 /* listen worker: register buffers */
1146 static int smc_listen_rdma_reg(struct smc_sock *new_smc, int local_contact)
1147 {
1148 	struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
1149 
1150 	if (local_contact != SMC_FIRST_CONTACT) {
1151 		if (smc_reg_rmb(link, new_smc->conn.rmb_desc, true))
1152 			return SMC_CLC_DECL_ERR_REGRMB;
1153 	}
1154 	smc_rmb_sync_sg_for_device(&new_smc->conn);
1155 
1156 	return 0;
1157 }
1158 
1159 /* listen worker: finish RDMA setup */
1160 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
1161 				  struct smc_clc_msg_accept_confirm *cclc,
1162 				  int local_contact)
1163 {
1164 	struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
1165 	int reason_code = 0;
1166 
1167 	if (local_contact == SMC_FIRST_CONTACT)
1168 		smc_link_save_peer_info(link, cclc);
1169 
1170 	if (smc_rmb_rtoken_handling(&new_smc->conn, cclc)) {
1171 		reason_code = SMC_CLC_DECL_ERR_RTOK;
1172 		goto decline;
1173 	}
1174 
1175 	if (local_contact == SMC_FIRST_CONTACT) {
1176 		if (smc_ib_ready_link(link)) {
1177 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
1178 			goto decline;
1179 		}
1180 		/* QP confirmation over RoCE fabric */
1181 		reason_code = smc_serv_conf_first_link(new_smc);
1182 		if (reason_code)
1183 			goto decline;
1184 	}
1185 	return 0;
1186 
1187 decline:
1188 	smc_listen_decline(new_smc, reason_code, local_contact);
1189 	return reason_code;
1190 }
1191 
1192 /* setup for RDMA connection of server */
1193 static void smc_listen_work(struct work_struct *work)
1194 {
1195 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
1196 						smc_listen_work);
1197 	struct socket *newclcsock = new_smc->clcsock;
1198 	struct smc_clc_msg_accept_confirm cclc;
1199 	struct smc_clc_msg_proposal *pclc;
1200 	struct smc_ib_device *ibdev;
1201 	bool ism_supported = false;
1202 	struct smcd_dev *ismdev;
1203 	u8 buf[SMC_CLC_MAX_LEN];
1204 	int local_contact = 0;
1205 	unsigned short vlan;
1206 	int reason_code = 0;
1207 	int rc = 0;
1208 	u8 ibport;
1209 
1210 	if (new_smc->use_fallback) {
1211 		smc_listen_out_connected(new_smc);
1212 		return;
1213 	}
1214 
1215 	/* check if peer is smc capable */
1216 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
1217 		new_smc->use_fallback = true;
1218 		new_smc->fallback_rsn = SMC_CLC_DECL_PEERNOSMC;
1219 		smc_listen_out_connected(new_smc);
1220 		return;
1221 	}
1222 
1223 	/* do inband token exchange -
1224 	 * wait for and receive SMC Proposal CLC message
1225 	 */
1226 	pclc = (struct smc_clc_msg_proposal *)&buf;
1227 	reason_code = smc_clc_wait_msg(new_smc, pclc, SMC_CLC_MAX_LEN,
1228 				       SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
1229 	if (reason_code) {
1230 		smc_listen_decline(new_smc, reason_code, 0);
1231 		return;
1232 	}
1233 
1234 	/* IPSec connections opt out of SMC-R optimizations */
1235 	if (using_ipsec(new_smc)) {
1236 		smc_listen_decline(new_smc, SMC_CLC_DECL_IPSEC, 0);
1237 		return;
1238 	}
1239 
1240 	mutex_lock(&smc_create_lgr_pending);
1241 	smc_close_init(new_smc);
1242 	smc_rx_init(new_smc);
1243 	smc_tx_init(new_smc);
1244 
1245 	/* check if ISM is available */
1246 	if ((pclc->hdr.path == SMC_TYPE_D || pclc->hdr.path == SMC_TYPE_B) &&
1247 	    !smc_check_ism(new_smc, &ismdev) &&
1248 	    !smc_listen_ism_init(new_smc, pclc, ismdev, &local_contact)) {
1249 		ism_supported = true;
1250 	}
1251 
1252 	/* check if RDMA is available */
1253 	if (!ism_supported &&
1254 	    ((pclc->hdr.path != SMC_TYPE_R && pclc->hdr.path != SMC_TYPE_B) ||
1255 	     smc_vlan_by_tcpsk(new_smc->clcsock, &vlan) ||
1256 	     smc_check_rdma(new_smc, &ibdev, &ibport, vlan, NULL) ||
1257 	     smc_listen_rdma_check(new_smc, pclc) ||
1258 	     smc_listen_rdma_init(new_smc, pclc, ibdev, ibport,
1259 				  &local_contact) ||
1260 	     smc_listen_rdma_reg(new_smc, local_contact))) {
1261 		/* SMC not supported, decline */
1262 		mutex_unlock(&smc_create_lgr_pending);
1263 		smc_listen_decline(new_smc, SMC_CLC_DECL_MODEUNSUPP,
1264 				   local_contact);
1265 		return;
1266 	}
1267 
1268 	/* send SMC Accept CLC message */
1269 	rc = smc_clc_send_accept(new_smc, local_contact);
1270 	if (rc) {
1271 		mutex_unlock(&smc_create_lgr_pending);
1272 		smc_listen_decline(new_smc, rc, local_contact);
1273 		return;
1274 	}
1275 
1276 	/* receive SMC Confirm CLC message */
1277 	reason_code = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
1278 				       SMC_CLC_CONFIRM, CLC_WAIT_TIME);
1279 	if (reason_code) {
1280 		mutex_unlock(&smc_create_lgr_pending);
1281 		smc_listen_decline(new_smc, reason_code, local_contact);
1282 		return;
1283 	}
1284 
1285 	/* finish worker */
1286 	if (!ism_supported) {
1287 		if (smc_listen_rdma_finish(new_smc, &cclc, local_contact)) {
1288 			mutex_unlock(&smc_create_lgr_pending);
1289 			return;
1290 		}
1291 	}
1292 	smc_conn_save_peer_info(new_smc, &cclc);
1293 	mutex_unlock(&smc_create_lgr_pending);
1294 	smc_listen_out_connected(new_smc);
1295 }
1296 
1297 static void smc_tcp_listen_work(struct work_struct *work)
1298 {
1299 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
1300 					     tcp_listen_work);
1301 	struct sock *lsk = &lsmc->sk;
1302 	struct smc_sock *new_smc;
1303 	int rc = 0;
1304 
1305 	lock_sock(lsk);
1306 	while (lsk->sk_state == SMC_LISTEN) {
1307 		rc = smc_clcsock_accept(lsmc, &new_smc);
1308 		if (rc)
1309 			goto out;
1310 		if (!new_smc)
1311 			continue;
1312 
1313 		new_smc->listen_smc = lsmc;
1314 		new_smc->use_fallback = lsmc->use_fallback;
1315 		new_smc->fallback_rsn = lsmc->fallback_rsn;
1316 		sock_hold(lsk); /* sock_put in smc_listen_work */
1317 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
1318 		smc_copy_sock_settings_to_smc(new_smc);
1319 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
1320 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
1321 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
1322 		if (!schedule_work(&new_smc->smc_listen_work))
1323 			sock_put(&new_smc->sk);
1324 	}
1325 
1326 out:
1327 	release_sock(lsk);
1328 	sock_put(&lsmc->sk); /* sock_hold in smc_listen */
1329 }
1330 
1331 static int smc_listen(struct socket *sock, int backlog)
1332 {
1333 	struct sock *sk = sock->sk;
1334 	struct smc_sock *smc;
1335 	int rc;
1336 
1337 	smc = smc_sk(sk);
1338 	lock_sock(sk);
1339 
1340 	rc = -EINVAL;
1341 	if ((sk->sk_state != SMC_INIT) && (sk->sk_state != SMC_LISTEN))
1342 		goto out;
1343 
1344 	rc = 0;
1345 	if (sk->sk_state == SMC_LISTEN) {
1346 		sk->sk_max_ack_backlog = backlog;
1347 		goto out;
1348 	}
1349 	/* some socket options are handled in core, so we could not apply
1350 	 * them to the clc socket -- copy smc socket options to clc socket
1351 	 */
1352 	smc_copy_sock_settings_to_clc(smc);
1353 	if (!smc->use_fallback)
1354 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1355 
1356 	rc = kernel_listen(smc->clcsock, backlog);
1357 	if (rc)
1358 		goto out;
1359 	sk->sk_max_ack_backlog = backlog;
1360 	sk->sk_ack_backlog = 0;
1361 	sk->sk_state = SMC_LISTEN;
1362 	sock_hold(sk); /* sock_hold in tcp_listen_worker */
1363 	if (!schedule_work(&smc->tcp_listen_work))
1364 		sock_put(sk);
1365 
1366 out:
1367 	release_sock(sk);
1368 	return rc;
1369 }
1370 
1371 static int smc_accept(struct socket *sock, struct socket *new_sock,
1372 		      int flags, bool kern)
1373 {
1374 	struct sock *sk = sock->sk, *nsk;
1375 	DECLARE_WAITQUEUE(wait, current);
1376 	struct smc_sock *lsmc;
1377 	long timeo;
1378 	int rc = 0;
1379 
1380 	lsmc = smc_sk(sk);
1381 	sock_hold(sk); /* sock_put below */
1382 	lock_sock(sk);
1383 
1384 	if (lsmc->sk.sk_state != SMC_LISTEN) {
1385 		rc = -EINVAL;
1386 		release_sock(sk);
1387 		goto out;
1388 	}
1389 
1390 	/* Wait for an incoming connection */
1391 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1392 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
1393 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1394 		set_current_state(TASK_INTERRUPTIBLE);
1395 		if (!timeo) {
1396 			rc = -EAGAIN;
1397 			break;
1398 		}
1399 		release_sock(sk);
1400 		timeo = schedule_timeout(timeo);
1401 		/* wakeup by sk_data_ready in smc_listen_work() */
1402 		sched_annotate_sleep();
1403 		lock_sock(sk);
1404 		if (signal_pending(current)) {
1405 			rc = sock_intr_errno(timeo);
1406 			break;
1407 		}
1408 	}
1409 	set_current_state(TASK_RUNNING);
1410 	remove_wait_queue(sk_sleep(sk), &wait);
1411 
1412 	if (!rc)
1413 		rc = sock_error(nsk);
1414 	release_sock(sk);
1415 	if (rc)
1416 		goto out;
1417 
1418 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
1419 		/* wait till data arrives on the socket */
1420 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
1421 								MSEC_PER_SEC);
1422 		if (smc_sk(nsk)->use_fallback) {
1423 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
1424 
1425 			lock_sock(clcsk);
1426 			if (skb_queue_empty(&clcsk->sk_receive_queue))
1427 				sk_wait_data(clcsk, &timeo, NULL);
1428 			release_sock(clcsk);
1429 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
1430 			lock_sock(nsk);
1431 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
1432 			release_sock(nsk);
1433 		}
1434 	}
1435 
1436 out:
1437 	sock_put(sk); /* sock_hold above */
1438 	return rc;
1439 }
1440 
1441 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1442 		       int peer)
1443 {
1444 	struct smc_sock *smc;
1445 
1446 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
1447 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
1448 		return -ENOTCONN;
1449 
1450 	smc = smc_sk(sock->sk);
1451 
1452 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
1453 }
1454 
1455 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1456 {
1457 	struct sock *sk = sock->sk;
1458 	struct smc_sock *smc;
1459 	int rc = -EPIPE;
1460 
1461 	smc = smc_sk(sk);
1462 	lock_sock(sk);
1463 	if ((sk->sk_state != SMC_ACTIVE) &&
1464 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1465 	    (sk->sk_state != SMC_INIT))
1466 		goto out;
1467 
1468 	if (msg->msg_flags & MSG_FASTOPEN) {
1469 		if (sk->sk_state == SMC_INIT) {
1470 			smc->use_fallback = true;
1471 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1472 		} else {
1473 			rc = -EINVAL;
1474 			goto out;
1475 		}
1476 	}
1477 
1478 	if (smc->use_fallback)
1479 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
1480 	else
1481 		rc = smc_tx_sendmsg(smc, msg, len);
1482 out:
1483 	release_sock(sk);
1484 	return rc;
1485 }
1486 
1487 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1488 		       int flags)
1489 {
1490 	struct sock *sk = sock->sk;
1491 	struct smc_sock *smc;
1492 	int rc = -ENOTCONN;
1493 
1494 	smc = smc_sk(sk);
1495 	lock_sock(sk);
1496 	if ((sk->sk_state == SMC_INIT) ||
1497 	    (sk->sk_state == SMC_LISTEN) ||
1498 	    (sk->sk_state == SMC_CLOSED))
1499 		goto out;
1500 
1501 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1502 		rc = 0;
1503 		goto out;
1504 	}
1505 
1506 	if (smc->use_fallback) {
1507 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
1508 	} else {
1509 		msg->msg_namelen = 0;
1510 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
1511 	}
1512 
1513 out:
1514 	release_sock(sk);
1515 	return rc;
1516 }
1517 
1518 static __poll_t smc_accept_poll(struct sock *parent)
1519 {
1520 	struct smc_sock *isk = smc_sk(parent);
1521 	__poll_t mask = 0;
1522 
1523 	spin_lock(&isk->accept_q_lock);
1524 	if (!list_empty(&isk->accept_q))
1525 		mask = EPOLLIN | EPOLLRDNORM;
1526 	spin_unlock(&isk->accept_q_lock);
1527 
1528 	return mask;
1529 }
1530 
1531 static __poll_t smc_poll(struct file *file, struct socket *sock,
1532 			     poll_table *wait)
1533 {
1534 	struct sock *sk = sock->sk;
1535 	__poll_t mask = 0;
1536 	struct smc_sock *smc;
1537 
1538 	if (!sk)
1539 		return EPOLLNVAL;
1540 
1541 	smc = smc_sk(sock->sk);
1542 	if (smc->use_fallback) {
1543 		/* delegate to CLC child sock */
1544 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
1545 		sk->sk_err = smc->clcsock->sk->sk_err;
1546 		if (sk->sk_err)
1547 			mask |= EPOLLERR;
1548 	} else {
1549 		if (sk->sk_state != SMC_CLOSED)
1550 			sock_poll_wait(file, sock, wait);
1551 		if (sk->sk_err)
1552 			mask |= EPOLLERR;
1553 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1554 		    (sk->sk_state == SMC_CLOSED))
1555 			mask |= EPOLLHUP;
1556 		if (sk->sk_state == SMC_LISTEN) {
1557 			/* woken up by sk_data_ready in smc_listen_work() */
1558 			mask = smc_accept_poll(sk);
1559 		} else {
1560 			if (atomic_read(&smc->conn.sndbuf_space) ||
1561 			    sk->sk_shutdown & SEND_SHUTDOWN) {
1562 				mask |= EPOLLOUT | EPOLLWRNORM;
1563 			} else {
1564 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1565 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1566 			}
1567 			if (atomic_read(&smc->conn.bytes_to_rcv))
1568 				mask |= EPOLLIN | EPOLLRDNORM;
1569 			if (sk->sk_shutdown & RCV_SHUTDOWN)
1570 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
1571 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
1572 				mask |= EPOLLIN;
1573 			if (smc->conn.urg_state == SMC_URG_VALID)
1574 				mask |= EPOLLPRI;
1575 		}
1576 	}
1577 
1578 	return mask;
1579 }
1580 
1581 static int smc_shutdown(struct socket *sock, int how)
1582 {
1583 	struct sock *sk = sock->sk;
1584 	struct smc_sock *smc;
1585 	int rc = -EINVAL;
1586 	int rc1 = 0;
1587 
1588 	smc = smc_sk(sk);
1589 
1590 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
1591 		return rc;
1592 
1593 	lock_sock(sk);
1594 
1595 	rc = -ENOTCONN;
1596 	if ((sk->sk_state != SMC_ACTIVE) &&
1597 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
1598 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
1599 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1600 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
1601 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
1602 		goto out;
1603 	if (smc->use_fallback) {
1604 		rc = kernel_sock_shutdown(smc->clcsock, how);
1605 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
1606 		if (sk->sk_shutdown == SHUTDOWN_MASK)
1607 			sk->sk_state = SMC_CLOSED;
1608 		goto out;
1609 	}
1610 	switch (how) {
1611 	case SHUT_RDWR:		/* shutdown in both directions */
1612 		rc = smc_close_active(smc);
1613 		break;
1614 	case SHUT_WR:
1615 		rc = smc_close_shutdown_write(smc);
1616 		break;
1617 	case SHUT_RD:
1618 		rc = 0;
1619 		/* nothing more to do because peer is not involved */
1620 		break;
1621 	}
1622 	if (smc->clcsock)
1623 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
1624 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
1625 	sk->sk_shutdown |= how + 1;
1626 
1627 out:
1628 	release_sock(sk);
1629 	return rc ? rc : rc1;
1630 }
1631 
1632 static int smc_setsockopt(struct socket *sock, int level, int optname,
1633 			  char __user *optval, unsigned int optlen)
1634 {
1635 	struct sock *sk = sock->sk;
1636 	struct smc_sock *smc;
1637 	int val, rc;
1638 
1639 	smc = smc_sk(sk);
1640 
1641 	/* generic setsockopts reaching us here always apply to the
1642 	 * CLC socket
1643 	 */
1644 	rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
1645 					   optval, optlen);
1646 	if (smc->clcsock->sk->sk_err) {
1647 		sk->sk_err = smc->clcsock->sk->sk_err;
1648 		sk->sk_error_report(sk);
1649 	}
1650 	if (rc)
1651 		return rc;
1652 
1653 	if (optlen < sizeof(int))
1654 		return -EINVAL;
1655 	if (get_user(val, (int __user *)optval))
1656 		return -EFAULT;
1657 
1658 	lock_sock(sk);
1659 	switch (optname) {
1660 	case TCP_ULP:
1661 	case TCP_FASTOPEN:
1662 	case TCP_FASTOPEN_CONNECT:
1663 	case TCP_FASTOPEN_KEY:
1664 	case TCP_FASTOPEN_NO_COOKIE:
1665 		/* option not supported by SMC */
1666 		if (sk->sk_state == SMC_INIT) {
1667 			smc->use_fallback = true;
1668 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1669 		} else {
1670 			if (!smc->use_fallback)
1671 				rc = -EINVAL;
1672 		}
1673 		break;
1674 	case TCP_NODELAY:
1675 		if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1676 			if (val && !smc->use_fallback)
1677 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1678 						 0);
1679 		}
1680 		break;
1681 	case TCP_CORK:
1682 		if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1683 			if (!val && !smc->use_fallback)
1684 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1685 						 0);
1686 		}
1687 		break;
1688 	case TCP_DEFER_ACCEPT:
1689 		smc->sockopt_defer_accept = val;
1690 		break;
1691 	default:
1692 		break;
1693 	}
1694 	release_sock(sk);
1695 
1696 	return rc;
1697 }
1698 
1699 static int smc_getsockopt(struct socket *sock, int level, int optname,
1700 			  char __user *optval, int __user *optlen)
1701 {
1702 	struct smc_sock *smc;
1703 
1704 	smc = smc_sk(sock->sk);
1705 	/* socket options apply to the CLC socket */
1706 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
1707 					     optval, optlen);
1708 }
1709 
1710 static int smc_ioctl(struct socket *sock, unsigned int cmd,
1711 		     unsigned long arg)
1712 {
1713 	union smc_host_cursor cons, urg;
1714 	struct smc_connection *conn;
1715 	struct smc_sock *smc;
1716 	int answ;
1717 
1718 	smc = smc_sk(sock->sk);
1719 	conn = &smc->conn;
1720 	lock_sock(&smc->sk);
1721 	if (smc->use_fallback) {
1722 		if (!smc->clcsock) {
1723 			release_sock(&smc->sk);
1724 			return -EBADF;
1725 		}
1726 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
1727 		release_sock(&smc->sk);
1728 		return answ;
1729 	}
1730 	switch (cmd) {
1731 	case SIOCINQ: /* same as FIONREAD */
1732 		if (smc->sk.sk_state == SMC_LISTEN) {
1733 			release_sock(&smc->sk);
1734 			return -EINVAL;
1735 		}
1736 		if (smc->sk.sk_state == SMC_INIT ||
1737 		    smc->sk.sk_state == SMC_CLOSED)
1738 			answ = 0;
1739 		else
1740 			answ = atomic_read(&smc->conn.bytes_to_rcv);
1741 		break;
1742 	case SIOCOUTQ:
1743 		/* output queue size (not send + not acked) */
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 = smc->conn.sndbuf_desc->len -
1753 					atomic_read(&smc->conn.sndbuf_space);
1754 		break;
1755 	case SIOCOUTQNSD:
1756 		/* output queue size (not send only) */
1757 		if (smc->sk.sk_state == SMC_LISTEN) {
1758 			release_sock(&smc->sk);
1759 			return -EINVAL;
1760 		}
1761 		if (smc->sk.sk_state == SMC_INIT ||
1762 		    smc->sk.sk_state == SMC_CLOSED)
1763 			answ = 0;
1764 		else
1765 			answ = smc_tx_prepared_sends(&smc->conn);
1766 		break;
1767 	case SIOCATMARK:
1768 		if (smc->sk.sk_state == SMC_LISTEN) {
1769 			release_sock(&smc->sk);
1770 			return -EINVAL;
1771 		}
1772 		if (smc->sk.sk_state == SMC_INIT ||
1773 		    smc->sk.sk_state == SMC_CLOSED) {
1774 			answ = 0;
1775 		} else {
1776 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
1777 			smc_curs_copy(&urg, &conn->urg_curs, conn);
1778 			answ = smc_curs_diff(conn->rmb_desc->len,
1779 					     &cons, &urg) == 1;
1780 		}
1781 		break;
1782 	default:
1783 		release_sock(&smc->sk);
1784 		return -ENOIOCTLCMD;
1785 	}
1786 	release_sock(&smc->sk);
1787 
1788 	return put_user(answ, (int __user *)arg);
1789 }
1790 
1791 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
1792 			    int offset, size_t size, int flags)
1793 {
1794 	struct sock *sk = sock->sk;
1795 	struct smc_sock *smc;
1796 	int rc = -EPIPE;
1797 
1798 	smc = smc_sk(sk);
1799 	lock_sock(sk);
1800 	if (sk->sk_state != SMC_ACTIVE) {
1801 		release_sock(sk);
1802 		goto out;
1803 	}
1804 	release_sock(sk);
1805 	if (smc->use_fallback)
1806 		rc = kernel_sendpage(smc->clcsock, page, offset,
1807 				     size, flags);
1808 	else
1809 		rc = sock_no_sendpage(sock, page, offset, size, flags);
1810 
1811 out:
1812 	return rc;
1813 }
1814 
1815 /* Map the affected portions of the rmbe into an spd, note the number of bytes
1816  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
1817  * updates till whenever a respective page has been fully processed.
1818  * Note that subsequent recv() calls have to wait till all splice() processing
1819  * completed.
1820  */
1821 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
1822 			       struct pipe_inode_info *pipe, size_t len,
1823 			       unsigned int flags)
1824 {
1825 	struct sock *sk = sock->sk;
1826 	struct smc_sock *smc;
1827 	int rc = -ENOTCONN;
1828 
1829 	smc = smc_sk(sk);
1830 	lock_sock(sk);
1831 
1832 	if (sk->sk_state == SMC_INIT ||
1833 	    sk->sk_state == SMC_LISTEN ||
1834 	    sk->sk_state == SMC_CLOSED)
1835 		goto out;
1836 
1837 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1838 		rc = 0;
1839 		goto out;
1840 	}
1841 
1842 	if (smc->use_fallback) {
1843 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
1844 						    pipe, len, flags);
1845 	} else {
1846 		if (*ppos) {
1847 			rc = -ESPIPE;
1848 			goto out;
1849 		}
1850 		if (flags & SPLICE_F_NONBLOCK)
1851 			flags = MSG_DONTWAIT;
1852 		else
1853 			flags = 0;
1854 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
1855 	}
1856 out:
1857 	release_sock(sk);
1858 
1859 	return rc;
1860 }
1861 
1862 /* must look like tcp */
1863 static const struct proto_ops smc_sock_ops = {
1864 	.family		= PF_SMC,
1865 	.owner		= THIS_MODULE,
1866 	.release	= smc_release,
1867 	.bind		= smc_bind,
1868 	.connect	= smc_connect,
1869 	.socketpair	= sock_no_socketpair,
1870 	.accept		= smc_accept,
1871 	.getname	= smc_getname,
1872 	.poll		= smc_poll,
1873 	.ioctl		= smc_ioctl,
1874 	.listen		= smc_listen,
1875 	.shutdown	= smc_shutdown,
1876 	.setsockopt	= smc_setsockopt,
1877 	.getsockopt	= smc_getsockopt,
1878 	.sendmsg	= smc_sendmsg,
1879 	.recvmsg	= smc_recvmsg,
1880 	.mmap		= sock_no_mmap,
1881 	.sendpage	= smc_sendpage,
1882 	.splice_read	= smc_splice_read,
1883 };
1884 
1885 static int smc_create(struct net *net, struct socket *sock, int protocol,
1886 		      int kern)
1887 {
1888 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
1889 	struct smc_sock *smc;
1890 	struct sock *sk;
1891 	int rc;
1892 
1893 	rc = -ESOCKTNOSUPPORT;
1894 	if (sock->type != SOCK_STREAM)
1895 		goto out;
1896 
1897 	rc = -EPROTONOSUPPORT;
1898 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
1899 		goto out;
1900 
1901 	rc = -ENOBUFS;
1902 	sock->ops = &smc_sock_ops;
1903 	sk = smc_sock_alloc(net, sock, protocol);
1904 	if (!sk)
1905 		goto out;
1906 
1907 	/* create internal TCP socket for CLC handshake and fallback */
1908 	smc = smc_sk(sk);
1909 	smc->use_fallback = false; /* assume rdma capability first */
1910 	smc->fallback_rsn = 0;
1911 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
1912 			      &smc->clcsock);
1913 	if (rc) {
1914 		sk_common_release(sk);
1915 		goto out;
1916 	}
1917 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
1918 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
1919 
1920 out:
1921 	return rc;
1922 }
1923 
1924 static const struct net_proto_family smc_sock_family_ops = {
1925 	.family	= PF_SMC,
1926 	.owner	= THIS_MODULE,
1927 	.create	= smc_create,
1928 };
1929 
1930 static int __init smc_init(void)
1931 {
1932 	int rc;
1933 
1934 	rc = smc_pnet_init();
1935 	if (rc)
1936 		return rc;
1937 
1938 	rc = smc_llc_init();
1939 	if (rc) {
1940 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
1941 		goto out_pnet;
1942 	}
1943 
1944 	rc = smc_cdc_init();
1945 	if (rc) {
1946 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
1947 		goto out_pnet;
1948 	}
1949 
1950 	rc = proto_register(&smc_proto, 1);
1951 	if (rc) {
1952 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
1953 		goto out_pnet;
1954 	}
1955 
1956 	rc = proto_register(&smc_proto6, 1);
1957 	if (rc) {
1958 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
1959 		goto out_proto;
1960 	}
1961 
1962 	rc = sock_register(&smc_sock_family_ops);
1963 	if (rc) {
1964 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
1965 		goto out_proto6;
1966 	}
1967 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
1968 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
1969 
1970 	rc = smc_ib_register_client();
1971 	if (rc) {
1972 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
1973 		goto out_sock;
1974 	}
1975 
1976 	static_branch_enable(&tcp_have_smc);
1977 	return 0;
1978 
1979 out_sock:
1980 	sock_unregister(PF_SMC);
1981 out_proto6:
1982 	proto_unregister(&smc_proto6);
1983 out_proto:
1984 	proto_unregister(&smc_proto);
1985 out_pnet:
1986 	smc_pnet_exit();
1987 	return rc;
1988 }
1989 
1990 static void __exit smc_exit(void)
1991 {
1992 	smc_core_exit();
1993 	static_branch_disable(&tcp_have_smc);
1994 	smc_ib_unregister_client();
1995 	sock_unregister(PF_SMC);
1996 	proto_unregister(&smc_proto6);
1997 	proto_unregister(&smc_proto);
1998 	smc_pnet_exit();
1999 }
2000 
2001 module_init(smc_init);
2002 module_exit(smc_exit);
2003 
2004 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
2005 MODULE_DESCRIPTION("smc socket address family");
2006 MODULE_LICENSE("GPL");
2007 MODULE_ALIAS_NETPROTO(PF_SMC);
2008