xref: /openbmc/linux/net/smc/af_smc.c (revision ed1666f6)
1 /*
2  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
3  *
4  *  AF_SMC protocol family socket handler keeping the AF_INET sock address type
5  *  applies to SOCK_STREAM sockets only
6  *  offers an alternative communication option for TCP-protocol sockets
7  *  applicable with RoCE-cards only
8  *
9  *  Initial restrictions:
10  *    - support for alternate links postponed
11  *
12  *  Copyright IBM Corp. 2016, 2018
13  *
14  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
15  *              based on prototype from Frank Blaschka
16  */
17 
18 #define KMSG_COMPONENT "smc"
19 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
20 
21 #include <linux/module.h>
22 #include <linux/socket.h>
23 #include <linux/workqueue.h>
24 #include <linux/in.h>
25 #include <linux/sched/signal.h>
26 #include <linux/if_vlan.h>
27 
28 #include <net/sock.h>
29 #include <net/tcp.h>
30 #include <net/smc.h>
31 #include <asm/ioctls.h>
32 
33 #include <net/net_namespace.h>
34 #include <net/netns/generic.h>
35 #include "smc_netns.h"
36 
37 #include "smc.h"
38 #include "smc_clc.h"
39 #include "smc_llc.h"
40 #include "smc_cdc.h"
41 #include "smc_core.h"
42 #include "smc_ib.h"
43 #include "smc_ism.h"
44 #include "smc_pnet.h"
45 #include "smc_tx.h"
46 #include "smc_rx.h"
47 #include "smc_close.h"
48 
49 static DEFINE_MUTEX(smc_server_lgr_pending);	/* serialize link group
50 						 * creation on server
51 						 */
52 static DEFINE_MUTEX(smc_client_lgr_pending);	/* serialize link group
53 						 * creation on client
54 						 */
55 
56 static void smc_tcp_listen_work(struct work_struct *);
57 static void smc_connect_work(struct work_struct *);
58 
59 static void smc_set_keepalive(struct sock *sk, int val)
60 {
61 	struct smc_sock *smc = smc_sk(sk);
62 
63 	smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
64 }
65 
66 static struct smc_hashinfo smc_v4_hashinfo = {
67 	.lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
68 };
69 
70 static struct smc_hashinfo smc_v6_hashinfo = {
71 	.lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
72 };
73 
74 int smc_hash_sk(struct sock *sk)
75 {
76 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
77 	struct hlist_head *head;
78 
79 	head = &h->ht;
80 
81 	write_lock_bh(&h->lock);
82 	sk_add_node(sk, head);
83 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
84 	write_unlock_bh(&h->lock);
85 
86 	return 0;
87 }
88 EXPORT_SYMBOL_GPL(smc_hash_sk);
89 
90 void smc_unhash_sk(struct sock *sk)
91 {
92 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
93 
94 	write_lock_bh(&h->lock);
95 	if (sk_del_node_init(sk))
96 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
97 	write_unlock_bh(&h->lock);
98 }
99 EXPORT_SYMBOL_GPL(smc_unhash_sk);
100 
101 struct proto smc_proto = {
102 	.name		= "SMC",
103 	.owner		= THIS_MODULE,
104 	.keepalive	= smc_set_keepalive,
105 	.hash		= smc_hash_sk,
106 	.unhash		= smc_unhash_sk,
107 	.obj_size	= sizeof(struct smc_sock),
108 	.h.smc_hash	= &smc_v4_hashinfo,
109 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
110 };
111 EXPORT_SYMBOL_GPL(smc_proto);
112 
113 struct proto smc_proto6 = {
114 	.name		= "SMC6",
115 	.owner		= THIS_MODULE,
116 	.keepalive	= smc_set_keepalive,
117 	.hash		= smc_hash_sk,
118 	.unhash		= smc_unhash_sk,
119 	.obj_size	= sizeof(struct smc_sock),
120 	.h.smc_hash	= &smc_v6_hashinfo,
121 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
122 };
123 EXPORT_SYMBOL_GPL(smc_proto6);
124 
125 static int smc_release(struct socket *sock)
126 {
127 	struct sock *sk = sock->sk;
128 	struct smc_sock *smc;
129 	int rc = 0;
130 
131 	if (!sk)
132 		goto out;
133 
134 	smc = smc_sk(sk);
135 
136 	/* cleanup for a dangling non-blocking connect */
137 	if (smc->connect_info && sk->sk_state == SMC_INIT)
138 		tcp_abort(smc->clcsock->sk, ECONNABORTED);
139 	flush_work(&smc->connect_work);
140 	kfree(smc->connect_info);
141 	smc->connect_info = NULL;
142 
143 	if (sk->sk_state == SMC_LISTEN)
144 		/* smc_close_non_accepted() is called and acquires
145 		 * sock lock for child sockets again
146 		 */
147 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
148 	else
149 		lock_sock(sk);
150 
151 	if (!smc->use_fallback) {
152 		rc = smc_close_active(smc);
153 		sock_set_flag(sk, SOCK_DEAD);
154 		sk->sk_shutdown |= SHUTDOWN_MASK;
155 	} else {
156 		if (sk->sk_state != SMC_LISTEN && sk->sk_state != SMC_INIT)
157 			sock_put(sk); /* passive closing */
158 		if (sk->sk_state == SMC_LISTEN) {
159 			/* wake up clcsock accept */
160 			rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
161 		}
162 		sk->sk_state = SMC_CLOSED;
163 		sk->sk_state_change(sk);
164 	}
165 
166 	sk->sk_prot->unhash(sk);
167 
168 	if (sk->sk_state == SMC_CLOSED) {
169 		if (smc->clcsock) {
170 			mutex_lock(&smc->clcsock_release_lock);
171 			sock_release(smc->clcsock);
172 			smc->clcsock = NULL;
173 			mutex_unlock(&smc->clcsock_release_lock);
174 		}
175 		if (!smc->use_fallback)
176 			smc_conn_free(&smc->conn);
177 	}
178 
179 	/* detach socket */
180 	sock_orphan(sk);
181 	sock->sk = NULL;
182 	release_sock(sk);
183 
184 	sock_put(sk); /* final sock_put */
185 out:
186 	return rc;
187 }
188 
189 static void smc_destruct(struct sock *sk)
190 {
191 	if (sk->sk_state != SMC_CLOSED)
192 		return;
193 	if (!sock_flag(sk, SOCK_DEAD))
194 		return;
195 
196 	sk_refcnt_debug_dec(sk);
197 }
198 
199 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
200 				   int protocol)
201 {
202 	struct smc_sock *smc;
203 	struct proto *prot;
204 	struct sock *sk;
205 
206 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
207 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
208 	if (!sk)
209 		return NULL;
210 
211 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
212 	sk->sk_state = SMC_INIT;
213 	sk->sk_destruct = smc_destruct;
214 	sk->sk_protocol = protocol;
215 	smc = smc_sk(sk);
216 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
217 	INIT_WORK(&smc->connect_work, smc_connect_work);
218 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
219 	INIT_LIST_HEAD(&smc->accept_q);
220 	spin_lock_init(&smc->accept_q_lock);
221 	spin_lock_init(&smc->conn.send_lock);
222 	sk->sk_prot->hash(sk);
223 	sk_refcnt_debug_inc(sk);
224 	mutex_init(&smc->clcsock_release_lock);
225 
226 	return sk;
227 }
228 
229 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
230 		    int addr_len)
231 {
232 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
233 	struct sock *sk = sock->sk;
234 	struct smc_sock *smc;
235 	int rc;
236 
237 	smc = smc_sk(sk);
238 
239 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
240 	rc = -EINVAL;
241 	if (addr_len < sizeof(struct sockaddr_in))
242 		goto out;
243 
244 	rc = -EAFNOSUPPORT;
245 	if (addr->sin_family != AF_INET &&
246 	    addr->sin_family != AF_INET6 &&
247 	    addr->sin_family != AF_UNSPEC)
248 		goto out;
249 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
250 	if (addr->sin_family == AF_UNSPEC &&
251 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
252 		goto out;
253 
254 	lock_sock(sk);
255 
256 	/* Check if socket is already active */
257 	rc = -EINVAL;
258 	if (sk->sk_state != SMC_INIT)
259 		goto out_rel;
260 
261 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
262 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
263 
264 out_rel:
265 	release_sock(sk);
266 out:
267 	return rc;
268 }
269 
270 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
271 				   unsigned long mask)
272 {
273 	/* options we don't get control via setsockopt for */
274 	nsk->sk_type = osk->sk_type;
275 	nsk->sk_sndbuf = osk->sk_sndbuf;
276 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
277 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
278 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
279 	nsk->sk_mark = osk->sk_mark;
280 	nsk->sk_priority = osk->sk_priority;
281 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
282 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
283 	nsk->sk_err = osk->sk_err;
284 
285 	nsk->sk_flags &= ~mask;
286 	nsk->sk_flags |= osk->sk_flags & mask;
287 }
288 
289 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
290 			     (1UL << SOCK_KEEPOPEN) | \
291 			     (1UL << SOCK_LINGER) | \
292 			     (1UL << SOCK_BROADCAST) | \
293 			     (1UL << SOCK_TIMESTAMP) | \
294 			     (1UL << SOCK_DBG) | \
295 			     (1UL << SOCK_RCVTSTAMP) | \
296 			     (1UL << SOCK_RCVTSTAMPNS) | \
297 			     (1UL << SOCK_LOCALROUTE) | \
298 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
299 			     (1UL << SOCK_RXQ_OVFL) | \
300 			     (1UL << SOCK_WIFI_STATUS) | \
301 			     (1UL << SOCK_NOFCS) | \
302 			     (1UL << SOCK_FILTER_LOCKED) | \
303 			     (1UL << SOCK_TSTAMP_NEW))
304 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
305  * clc socket (since smc is not called for these options from net/core)
306  */
307 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
308 {
309 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
310 }
311 
312 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
313 			     (1UL << SOCK_KEEPOPEN) | \
314 			     (1UL << SOCK_LINGER) | \
315 			     (1UL << SOCK_DBG))
316 /* copy only settings and flags relevant for smc from clc to smc socket */
317 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
318 {
319 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
320 }
321 
322 /* register a new rmb, send confirm_rkey msg to register with peer */
323 static int smc_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc,
324 		       bool conf_rkey)
325 {
326 	if (!rmb_desc->wr_reg) {
327 		/* register memory region for new rmb */
328 		if (smc_wr_reg_send(link, rmb_desc->mr_rx[SMC_SINGLE_LINK])) {
329 			rmb_desc->regerr = 1;
330 			return -EFAULT;
331 		}
332 		rmb_desc->wr_reg = 1;
333 	}
334 	if (!conf_rkey)
335 		return 0;
336 	/* exchange confirm_rkey msg with peer */
337 	if (smc_llc_do_confirm_rkey(link, rmb_desc)) {
338 		rmb_desc->regerr = 1;
339 		return -EFAULT;
340 	}
341 	return 0;
342 }
343 
344 static int smc_clnt_conf_first_link(struct smc_sock *smc)
345 {
346 	struct net *net = sock_net(smc->clcsock->sk);
347 	struct smc_link_group *lgr = smc->conn.lgr;
348 	struct smc_link *link;
349 	int rest;
350 	int rc;
351 
352 	link = &lgr->lnk[SMC_SINGLE_LINK];
353 	/* receive CONFIRM LINK request from server over RoCE fabric */
354 	rest = wait_for_completion_interruptible_timeout(
355 		&link->llc_confirm,
356 		SMC_LLC_WAIT_FIRST_TIME);
357 	if (rest <= 0) {
358 		struct smc_clc_msg_decline dclc;
359 
360 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
361 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
362 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
363 	}
364 
365 	if (link->llc_confirm_rc)
366 		return SMC_CLC_DECL_RMBE_EC;
367 
368 	rc = smc_ib_modify_qp_rts(link);
369 	if (rc)
370 		return SMC_CLC_DECL_ERR_RDYLNK;
371 
372 	smc_wr_remember_qp_attr(link);
373 
374 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
375 		return SMC_CLC_DECL_ERR_REGRMB;
376 
377 	/* send CONFIRM LINK response over RoCE fabric */
378 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
379 	if (rc < 0)
380 		return SMC_CLC_DECL_TIMEOUT_CL;
381 
382 	/* receive ADD LINK request from server over RoCE fabric */
383 	rest = wait_for_completion_interruptible_timeout(&link->llc_add,
384 							 SMC_LLC_WAIT_TIME);
385 	if (rest <= 0) {
386 		struct smc_clc_msg_decline dclc;
387 
388 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
389 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
390 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_AL : rc;
391 	}
392 
393 	/* send add link reject message, only one link supported for now */
394 	rc = smc_llc_send_add_link(link,
395 				   link->smcibdev->mac[link->ibport - 1],
396 				   link->gid, SMC_LLC_RESP);
397 	if (rc < 0)
398 		return SMC_CLC_DECL_TIMEOUT_AL;
399 
400 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
401 
402 	return 0;
403 }
404 
405 static void smcr_conn_save_peer_info(struct smc_sock *smc,
406 				     struct smc_clc_msg_accept_confirm *clc)
407 {
408 	int bufsize = smc_uncompress_bufsize(clc->rmbe_size);
409 
410 	smc->conn.peer_rmbe_idx = clc->rmbe_idx;
411 	smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
412 	smc->conn.peer_rmbe_size = bufsize;
413 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
414 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
415 }
416 
417 static void smcd_conn_save_peer_info(struct smc_sock *smc,
418 				     struct smc_clc_msg_accept_confirm *clc)
419 {
420 	int bufsize = smc_uncompress_bufsize(clc->dmbe_size);
421 
422 	smc->conn.peer_rmbe_idx = clc->dmbe_idx;
423 	smc->conn.peer_token = clc->token;
424 	/* msg header takes up space in the buffer */
425 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
426 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
427 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
428 }
429 
430 static void smc_conn_save_peer_info(struct smc_sock *smc,
431 				    struct smc_clc_msg_accept_confirm *clc)
432 {
433 	if (smc->conn.lgr->is_smcd)
434 		smcd_conn_save_peer_info(smc, clc);
435 	else
436 		smcr_conn_save_peer_info(smc, clc);
437 }
438 
439 static void smc_link_save_peer_info(struct smc_link *link,
440 				    struct smc_clc_msg_accept_confirm *clc)
441 {
442 	link->peer_qpn = ntoh24(clc->qpn);
443 	memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
444 	memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
445 	link->peer_psn = ntoh24(clc->psn);
446 	link->peer_mtu = clc->qp_mtu;
447 }
448 
449 /* fall back during connect */
450 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
451 {
452 	smc->use_fallback = true;
453 	smc->fallback_rsn = reason_code;
454 	smc_copy_sock_settings_to_clc(smc);
455 	if (smc->sk.sk_state == SMC_INIT)
456 		smc->sk.sk_state = SMC_ACTIVE;
457 	return 0;
458 }
459 
460 /* decline and fall back during connect */
461 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code)
462 {
463 	int rc;
464 
465 	if (reason_code < 0) { /* error, fallback is not possible */
466 		if (smc->sk.sk_state == SMC_INIT)
467 			sock_put(&smc->sk); /* passive closing */
468 		return reason_code;
469 	}
470 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
471 		rc = smc_clc_send_decline(smc, reason_code);
472 		if (rc < 0) {
473 			if (smc->sk.sk_state == SMC_INIT)
474 				sock_put(&smc->sk); /* passive closing */
475 			return rc;
476 		}
477 	}
478 	return smc_connect_fallback(smc, reason_code);
479 }
480 
481 /* abort connecting */
482 static int smc_connect_abort(struct smc_sock *smc, int reason_code,
483 			     int local_contact)
484 {
485 	if (local_contact == SMC_FIRST_CONTACT)
486 		smc_lgr_forget(smc->conn.lgr);
487 	if (smc->conn.lgr->is_smcd)
488 		/* there is only one lgr role for SMC-D; use server lock */
489 		mutex_unlock(&smc_server_lgr_pending);
490 	else
491 		mutex_unlock(&smc_client_lgr_pending);
492 
493 	smc_conn_free(&smc->conn);
494 	return reason_code;
495 }
496 
497 /* check if there is a rdma device available for this connection. */
498 /* called for connect and listen */
499 static int smc_check_rdma(struct smc_sock *smc, struct smc_ib_device **ibdev,
500 			  u8 *ibport, unsigned short vlan_id, u8 gid[])
501 {
502 	int reason_code = 0;
503 
504 	/* PNET table look up: search active ib_device and port
505 	 * within same PNETID that also contains the ethernet device
506 	 * used for the internal TCP socket
507 	 */
508 	smc_pnet_find_roce_resource(smc->clcsock->sk, ibdev, ibport, vlan_id,
509 				    gid);
510 	if (!(*ibdev))
511 		reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
512 
513 	return reason_code;
514 }
515 
516 /* check if there is an ISM device available for this connection. */
517 /* called for connect and listen */
518 static int smc_check_ism(struct smc_sock *smc, struct smcd_dev **ismdev)
519 {
520 	/* Find ISM device with same PNETID as connecting interface  */
521 	smc_pnet_find_ism_resource(smc->clcsock->sk, ismdev);
522 	if (!(*ismdev))
523 		return SMC_CLC_DECL_CNFERR; /* configuration error */
524 	return 0;
525 }
526 
527 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
528 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
529 				      struct smcd_dev *ismdev,
530 				      unsigned short vlan_id)
531 {
532 	if (vlan_id && smc_ism_get_vlan(ismdev, vlan_id))
533 		return SMC_CLC_DECL_CNFERR;
534 	return 0;
535 }
536 
537 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
538  * used, the VLAN ID will be registered again during the connection setup.
539  */
540 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc, bool is_smcd,
541 					struct smcd_dev *ismdev,
542 					unsigned short vlan_id)
543 {
544 	if (!is_smcd)
545 		return 0;
546 	if (vlan_id && smc_ism_put_vlan(ismdev, vlan_id))
547 		return SMC_CLC_DECL_CNFERR;
548 	return 0;
549 }
550 
551 /* CLC handshake during connect */
552 static int smc_connect_clc(struct smc_sock *smc, int smc_type,
553 			   struct smc_clc_msg_accept_confirm *aclc,
554 			   struct smc_ib_device *ibdev, u8 ibport,
555 			   u8 gid[], struct smcd_dev *ismdev)
556 {
557 	int rc = 0;
558 
559 	/* do inband token exchange */
560 	rc = smc_clc_send_proposal(smc, smc_type, ibdev, ibport, gid, ismdev);
561 	if (rc)
562 		return rc;
563 	/* receive SMC Accept CLC message */
564 	return smc_clc_wait_msg(smc, aclc, sizeof(*aclc), SMC_CLC_ACCEPT,
565 				CLC_WAIT_TIME);
566 }
567 
568 /* setup for RDMA connection of client */
569 static int smc_connect_rdma(struct smc_sock *smc,
570 			    struct smc_clc_msg_accept_confirm *aclc,
571 			    struct smc_ib_device *ibdev, u8 ibport)
572 {
573 	int local_contact = SMC_FIRST_CONTACT;
574 	struct smc_link *link;
575 	int reason_code = 0;
576 
577 	mutex_lock(&smc_client_lgr_pending);
578 	local_contact = smc_conn_create(smc, false, aclc->hdr.flag, ibdev,
579 					ibport, ntoh24(aclc->qpn), &aclc->lcl,
580 					NULL, 0);
581 	if (local_contact < 0) {
582 		if (local_contact == -ENOMEM)
583 			reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
584 		else if (local_contact == -ENOLINK)
585 			reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
586 		else
587 			reason_code = SMC_CLC_DECL_INTERR; /* other error */
588 		mutex_unlock(&smc_client_lgr_pending);
589 		return reason_code;
590 	}
591 	link = &smc->conn.lgr->lnk[SMC_SINGLE_LINK];
592 
593 	smc_conn_save_peer_info(smc, aclc);
594 
595 	/* create send buffer and rmb */
596 	if (smc_buf_create(smc, false))
597 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM, local_contact);
598 
599 	if (local_contact == SMC_FIRST_CONTACT)
600 		smc_link_save_peer_info(link, aclc);
601 
602 	if (smc_rmb_rtoken_handling(&smc->conn, aclc))
603 		return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RTOK,
604 					 local_contact);
605 
606 	smc_close_init(smc);
607 	smc_rx_init(smc);
608 
609 	if (local_contact == SMC_FIRST_CONTACT) {
610 		if (smc_ib_ready_link(link))
611 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RDYLNK,
612 						 local_contact);
613 	} else {
614 		if (smc_reg_rmb(link, smc->conn.rmb_desc, true))
615 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_REGRMB,
616 						 local_contact);
617 	}
618 	smc_rmb_sync_sg_for_device(&smc->conn);
619 
620 	reason_code = smc_clc_send_confirm(smc);
621 	if (reason_code)
622 		return smc_connect_abort(smc, reason_code, local_contact);
623 
624 	smc_tx_init(smc);
625 
626 	if (local_contact == SMC_FIRST_CONTACT) {
627 		/* QP confirmation over RoCE fabric */
628 		reason_code = smc_clnt_conf_first_link(smc);
629 		if (reason_code)
630 			return smc_connect_abort(smc, reason_code,
631 						 local_contact);
632 	}
633 	mutex_unlock(&smc_client_lgr_pending);
634 
635 	smc_copy_sock_settings_to_clc(smc);
636 	if (smc->sk.sk_state == SMC_INIT)
637 		smc->sk.sk_state = SMC_ACTIVE;
638 
639 	return 0;
640 }
641 
642 /* setup for ISM connection of client */
643 static int smc_connect_ism(struct smc_sock *smc,
644 			   struct smc_clc_msg_accept_confirm *aclc,
645 			   struct smcd_dev *ismdev)
646 {
647 	int local_contact = SMC_FIRST_CONTACT;
648 	int rc = 0;
649 
650 	/* there is only one lgr role for SMC-D; use server lock */
651 	mutex_lock(&smc_server_lgr_pending);
652 	local_contact = smc_conn_create(smc, true, aclc->hdr.flag, NULL, 0, 0,
653 					NULL, ismdev, aclc->gid);
654 	if (local_contact < 0) {
655 		mutex_unlock(&smc_server_lgr_pending);
656 		return SMC_CLC_DECL_MEM;
657 	}
658 
659 	/* Create send and receive buffers */
660 	if (smc_buf_create(smc, true))
661 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM, local_contact);
662 
663 	smc_conn_save_peer_info(smc, aclc);
664 	smc_close_init(smc);
665 	smc_rx_init(smc);
666 	smc_tx_init(smc);
667 
668 	rc = smc_clc_send_confirm(smc);
669 	if (rc)
670 		return smc_connect_abort(smc, rc, local_contact);
671 	mutex_unlock(&smc_server_lgr_pending);
672 
673 	smc_copy_sock_settings_to_clc(smc);
674 	if (smc->sk.sk_state == SMC_INIT)
675 		smc->sk.sk_state = SMC_ACTIVE;
676 
677 	return 0;
678 }
679 
680 /* perform steps before actually connecting */
681 static int __smc_connect(struct smc_sock *smc)
682 {
683 	bool ism_supported = false, rdma_supported = false;
684 	struct smc_clc_msg_accept_confirm aclc;
685 	struct smc_ib_device *ibdev;
686 	struct smcd_dev *ismdev;
687 	u8 gid[SMC_GID_SIZE];
688 	unsigned short vlan;
689 	int smc_type;
690 	int rc = 0;
691 	u8 ibport;
692 
693 	sock_hold(&smc->sk); /* sock put in passive closing */
694 
695 	if (smc->use_fallback)
696 		return smc_connect_fallback(smc, smc->fallback_rsn);
697 
698 	/* if peer has not signalled SMC-capability, fall back */
699 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
700 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
701 
702 	/* IPSec connections opt out of SMC-R optimizations */
703 	if (using_ipsec(smc))
704 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC);
705 
706 	/* check for VLAN ID */
707 	if (smc_vlan_by_tcpsk(smc->clcsock, &vlan))
708 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_CNFERR);
709 
710 	/* check if there is an ism device available */
711 	if (!smc_check_ism(smc, &ismdev) &&
712 	    !smc_connect_ism_vlan_setup(smc, ismdev, vlan)) {
713 		/* ISM is supported for this connection */
714 		ism_supported = true;
715 		smc_type = SMC_TYPE_D;
716 	}
717 
718 	/* check if there is a rdma device available */
719 	if (!smc_check_rdma(smc, &ibdev, &ibport, vlan, gid)) {
720 		/* RDMA is supported for this connection */
721 		rdma_supported = true;
722 		if (ism_supported)
723 			smc_type = SMC_TYPE_B; /* both */
724 		else
725 			smc_type = SMC_TYPE_R; /* only RDMA */
726 	}
727 
728 	/* if neither ISM nor RDMA are supported, fallback */
729 	if (!rdma_supported && !ism_supported)
730 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_NOSMCDEV);
731 
732 	/* perform CLC handshake */
733 	rc = smc_connect_clc(smc, smc_type, &aclc, ibdev, ibport, gid, ismdev);
734 	if (rc) {
735 		smc_connect_ism_vlan_cleanup(smc, ism_supported, ismdev, vlan);
736 		return smc_connect_decline_fallback(smc, rc);
737 	}
738 
739 	/* depending on previous steps, connect using rdma or ism */
740 	if (rdma_supported && aclc.hdr.path == SMC_TYPE_R)
741 		rc = smc_connect_rdma(smc, &aclc, ibdev, ibport);
742 	else if (ism_supported && aclc.hdr.path == SMC_TYPE_D)
743 		rc = smc_connect_ism(smc, &aclc, ismdev);
744 	else
745 		rc = SMC_CLC_DECL_MODEUNSUPP;
746 	if (rc) {
747 		smc_connect_ism_vlan_cleanup(smc, ism_supported, ismdev, vlan);
748 		return smc_connect_decline_fallback(smc, rc);
749 	}
750 
751 	smc_connect_ism_vlan_cleanup(smc, ism_supported, ismdev, vlan);
752 	return 0;
753 }
754 
755 static void smc_connect_work(struct work_struct *work)
756 {
757 	struct smc_sock *smc = container_of(work, struct smc_sock,
758 					    connect_work);
759 	int rc;
760 
761 	lock_sock(&smc->sk);
762 	rc = kernel_connect(smc->clcsock, &smc->connect_info->addr,
763 			    smc->connect_info->alen, smc->connect_info->flags);
764 	if (smc->clcsock->sk->sk_err) {
765 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
766 		goto out;
767 	}
768 	if (rc < 0) {
769 		smc->sk.sk_err = -rc;
770 		goto out;
771 	}
772 
773 	rc = __smc_connect(smc);
774 	if (rc < 0)
775 		smc->sk.sk_err = -rc;
776 
777 out:
778 	if (smc->sk.sk_err)
779 		smc->sk.sk_state_change(&smc->sk);
780 	else
781 		smc->sk.sk_write_space(&smc->sk);
782 	kfree(smc->connect_info);
783 	smc->connect_info = NULL;
784 	release_sock(&smc->sk);
785 }
786 
787 static int smc_connect(struct socket *sock, struct sockaddr *addr,
788 		       int alen, int flags)
789 {
790 	struct sock *sk = sock->sk;
791 	struct smc_sock *smc;
792 	int rc = -EINVAL;
793 
794 	smc = smc_sk(sk);
795 
796 	/* separate smc parameter checking to be safe */
797 	if (alen < sizeof(addr->sa_family))
798 		goto out_err;
799 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
800 		goto out_err;
801 
802 	lock_sock(sk);
803 	switch (sk->sk_state) {
804 	default:
805 		goto out;
806 	case SMC_ACTIVE:
807 		rc = -EISCONN;
808 		goto out;
809 	case SMC_INIT:
810 		rc = 0;
811 		break;
812 	}
813 
814 	smc_copy_sock_settings_to_clc(smc);
815 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
816 	if (flags & O_NONBLOCK) {
817 		if (smc->connect_info) {
818 			rc = -EALREADY;
819 			goto out;
820 		}
821 		smc->connect_info = kzalloc(alen + 2 * sizeof(int), GFP_KERNEL);
822 		if (!smc->connect_info) {
823 			rc = -ENOMEM;
824 			goto out;
825 		}
826 		smc->connect_info->alen = alen;
827 		smc->connect_info->flags = flags ^ O_NONBLOCK;
828 		memcpy(&smc->connect_info->addr, addr, alen);
829 		schedule_work(&smc->connect_work);
830 		rc = -EINPROGRESS;
831 	} else {
832 		rc = kernel_connect(smc->clcsock, addr, alen, flags);
833 		if (rc)
834 			goto out;
835 
836 		rc = __smc_connect(smc);
837 		if (rc < 0)
838 			goto out;
839 		else
840 			rc = 0; /* success cases including fallback */
841 	}
842 
843 out:
844 	release_sock(sk);
845 out_err:
846 	return rc;
847 }
848 
849 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
850 {
851 	struct socket *new_clcsock = NULL;
852 	struct sock *lsk = &lsmc->sk;
853 	struct sock *new_sk;
854 	int rc = -EINVAL;
855 
856 	release_sock(lsk);
857 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
858 	if (!new_sk) {
859 		rc = -ENOMEM;
860 		lsk->sk_err = ENOMEM;
861 		*new_smc = NULL;
862 		lock_sock(lsk);
863 		goto out;
864 	}
865 	*new_smc = smc_sk(new_sk);
866 
867 	mutex_lock(&lsmc->clcsock_release_lock);
868 	if (lsmc->clcsock)
869 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
870 	mutex_unlock(&lsmc->clcsock_release_lock);
871 	lock_sock(lsk);
872 	if  (rc < 0)
873 		lsk->sk_err = -rc;
874 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
875 		if (new_clcsock)
876 			sock_release(new_clcsock);
877 		new_sk->sk_state = SMC_CLOSED;
878 		sock_set_flag(new_sk, SOCK_DEAD);
879 		new_sk->sk_prot->unhash(new_sk);
880 		sock_put(new_sk); /* final */
881 		*new_smc = NULL;
882 		goto out;
883 	}
884 
885 	(*new_smc)->clcsock = new_clcsock;
886 out:
887 	return rc;
888 }
889 
890 /* add a just created sock to the accept queue of the listen sock as
891  * candidate for a following socket accept call from user space
892  */
893 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
894 {
895 	struct smc_sock *par = smc_sk(parent);
896 
897 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
898 	spin_lock(&par->accept_q_lock);
899 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
900 	spin_unlock(&par->accept_q_lock);
901 	sk_acceptq_added(parent);
902 }
903 
904 /* remove a socket from the accept queue of its parental listening socket */
905 static void smc_accept_unlink(struct sock *sk)
906 {
907 	struct smc_sock *par = smc_sk(sk)->listen_smc;
908 
909 	spin_lock(&par->accept_q_lock);
910 	list_del_init(&smc_sk(sk)->accept_q);
911 	spin_unlock(&par->accept_q_lock);
912 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
913 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
914 }
915 
916 /* remove a sock from the accept queue to bind it to a new socket created
917  * for a socket accept call from user space
918  */
919 struct sock *smc_accept_dequeue(struct sock *parent,
920 				struct socket *new_sock)
921 {
922 	struct smc_sock *isk, *n;
923 	struct sock *new_sk;
924 
925 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
926 		new_sk = (struct sock *)isk;
927 
928 		smc_accept_unlink(new_sk);
929 		if (new_sk->sk_state == SMC_CLOSED) {
930 			if (isk->clcsock) {
931 				sock_release(isk->clcsock);
932 				isk->clcsock = NULL;
933 			}
934 			new_sk->sk_prot->unhash(new_sk);
935 			sock_put(new_sk); /* final */
936 			continue;
937 		}
938 		if (new_sock)
939 			sock_graft(new_sk, new_sock);
940 		return new_sk;
941 	}
942 	return NULL;
943 }
944 
945 /* clean up for a created but never accepted sock */
946 void smc_close_non_accepted(struct sock *sk)
947 {
948 	struct smc_sock *smc = smc_sk(sk);
949 
950 	lock_sock(sk);
951 	if (!sk->sk_lingertime)
952 		/* wait for peer closing */
953 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
954 	if (!smc->use_fallback) {
955 		smc_close_active(smc);
956 		sock_set_flag(sk, SOCK_DEAD);
957 		sk->sk_shutdown |= SHUTDOWN_MASK;
958 	}
959 	if (smc->clcsock) {
960 		struct socket *tcp;
961 
962 		tcp = smc->clcsock;
963 		smc->clcsock = NULL;
964 		sock_release(tcp);
965 	}
966 	if (smc->use_fallback) {
967 		sock_put(sk); /* passive closing */
968 		sk->sk_state = SMC_CLOSED;
969 	} else {
970 		if (sk->sk_state == SMC_CLOSED)
971 			smc_conn_free(&smc->conn);
972 	}
973 	release_sock(sk);
974 	sk->sk_prot->unhash(sk);
975 	sock_put(sk); /* final sock_put */
976 }
977 
978 static int smc_serv_conf_first_link(struct smc_sock *smc)
979 {
980 	struct net *net = sock_net(smc->clcsock->sk);
981 	struct smc_link_group *lgr = smc->conn.lgr;
982 	struct smc_link *link;
983 	int rest;
984 	int rc;
985 
986 	link = &lgr->lnk[SMC_SINGLE_LINK];
987 
988 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
989 		return SMC_CLC_DECL_ERR_REGRMB;
990 
991 	/* send CONFIRM LINK request to client over the RoCE fabric */
992 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
993 	if (rc < 0)
994 		return SMC_CLC_DECL_TIMEOUT_CL;
995 
996 	/* receive CONFIRM LINK response from client over the RoCE fabric */
997 	rest = wait_for_completion_interruptible_timeout(
998 		&link->llc_confirm_resp,
999 		SMC_LLC_WAIT_FIRST_TIME);
1000 	if (rest <= 0) {
1001 		struct smc_clc_msg_decline dclc;
1002 
1003 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1004 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1005 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
1006 	}
1007 
1008 	if (link->llc_confirm_resp_rc)
1009 		return SMC_CLC_DECL_RMBE_EC;
1010 
1011 	/* send ADD LINK request to client over the RoCE fabric */
1012 	rc = smc_llc_send_add_link(link,
1013 				   link->smcibdev->mac[link->ibport - 1],
1014 				   link->gid, SMC_LLC_REQ);
1015 	if (rc < 0)
1016 		return SMC_CLC_DECL_TIMEOUT_AL;
1017 
1018 	/* receive ADD LINK response from client over the RoCE fabric */
1019 	rest = wait_for_completion_interruptible_timeout(&link->llc_add_resp,
1020 							 SMC_LLC_WAIT_TIME);
1021 	if (rest <= 0) {
1022 		struct smc_clc_msg_decline dclc;
1023 
1024 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1025 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1026 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_AL : rc;
1027 	}
1028 
1029 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
1030 
1031 	return 0;
1032 }
1033 
1034 /* listen worker: finish */
1035 static void smc_listen_out(struct smc_sock *new_smc)
1036 {
1037 	struct smc_sock *lsmc = new_smc->listen_smc;
1038 	struct sock *newsmcsk = &new_smc->sk;
1039 
1040 	lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1041 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1042 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1043 	} else { /* no longer listening */
1044 		smc_close_non_accepted(newsmcsk);
1045 	}
1046 	release_sock(&lsmc->sk);
1047 
1048 	/* Wake up accept */
1049 	lsmc->sk.sk_data_ready(&lsmc->sk);
1050 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1051 }
1052 
1053 /* listen worker: finish in state connected */
1054 static void smc_listen_out_connected(struct smc_sock *new_smc)
1055 {
1056 	struct sock *newsmcsk = &new_smc->sk;
1057 
1058 	sk_refcnt_debug_inc(newsmcsk);
1059 	if (newsmcsk->sk_state == SMC_INIT)
1060 		newsmcsk->sk_state = SMC_ACTIVE;
1061 
1062 	smc_listen_out(new_smc);
1063 }
1064 
1065 /* listen worker: finish in error state */
1066 static void smc_listen_out_err(struct smc_sock *new_smc)
1067 {
1068 	struct sock *newsmcsk = &new_smc->sk;
1069 
1070 	if (newsmcsk->sk_state == SMC_INIT)
1071 		sock_put(&new_smc->sk); /* passive closing */
1072 	newsmcsk->sk_state = SMC_CLOSED;
1073 	smc_conn_free(&new_smc->conn);
1074 
1075 	smc_listen_out(new_smc);
1076 }
1077 
1078 /* listen worker: decline and fall back if possible */
1079 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1080 			       int local_contact)
1081 {
1082 	/* RDMA setup failed, switch back to TCP */
1083 	if (local_contact == SMC_FIRST_CONTACT)
1084 		smc_lgr_forget(new_smc->conn.lgr);
1085 	if (reason_code < 0) { /* error, no fallback possible */
1086 		smc_listen_out_err(new_smc);
1087 		return;
1088 	}
1089 	smc_conn_free(&new_smc->conn);
1090 	new_smc->use_fallback = true;
1091 	new_smc->fallback_rsn = reason_code;
1092 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1093 		if (smc_clc_send_decline(new_smc, reason_code) < 0) {
1094 			smc_listen_out_err(new_smc);
1095 			return;
1096 		}
1097 	}
1098 	smc_listen_out_connected(new_smc);
1099 }
1100 
1101 /* listen worker: check prefixes */
1102 static int smc_listen_rdma_check(struct smc_sock *new_smc,
1103 				 struct smc_clc_msg_proposal *pclc)
1104 {
1105 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1106 	struct socket *newclcsock = new_smc->clcsock;
1107 
1108 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1109 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1110 		return SMC_CLC_DECL_CNFERR;
1111 
1112 	return 0;
1113 }
1114 
1115 /* listen worker: initialize connection and buffers */
1116 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1117 				struct smc_clc_msg_proposal *pclc,
1118 				struct smc_ib_device *ibdev, u8 ibport,
1119 				int *local_contact)
1120 {
1121 	/* allocate connection / link group */
1122 	*local_contact = smc_conn_create(new_smc, false, 0, ibdev, ibport, 0,
1123 					 &pclc->lcl, NULL, 0);
1124 	if (*local_contact < 0) {
1125 		if (*local_contact == -ENOMEM)
1126 			return SMC_CLC_DECL_MEM;/* insufficient memory*/
1127 		return SMC_CLC_DECL_INTERR; /* other error */
1128 	}
1129 
1130 	/* create send buffer and rmb */
1131 	if (smc_buf_create(new_smc, false))
1132 		return SMC_CLC_DECL_MEM;
1133 
1134 	return 0;
1135 }
1136 
1137 /* listen worker: initialize connection and buffers for SMC-D */
1138 static int smc_listen_ism_init(struct smc_sock *new_smc,
1139 			       struct smc_clc_msg_proposal *pclc,
1140 			       struct smcd_dev *ismdev,
1141 			       int *local_contact)
1142 {
1143 	struct smc_clc_msg_smcd *pclc_smcd;
1144 
1145 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
1146 	*local_contact = smc_conn_create(new_smc, true, 0, NULL, 0, 0, NULL,
1147 					 ismdev, pclc_smcd->gid);
1148 	if (*local_contact < 0) {
1149 		if (*local_contact == -ENOMEM)
1150 			return SMC_CLC_DECL_MEM;/* insufficient memory*/
1151 		return SMC_CLC_DECL_INTERR; /* other error */
1152 	}
1153 
1154 	/* Check if peer can be reached via ISM device */
1155 	if (smc_ism_cantalk(new_smc->conn.lgr->peer_gid,
1156 			    new_smc->conn.lgr->vlan_id,
1157 			    new_smc->conn.lgr->smcd)) {
1158 		if (*local_contact == SMC_FIRST_CONTACT)
1159 			smc_lgr_forget(new_smc->conn.lgr);
1160 		smc_conn_free(&new_smc->conn);
1161 		return SMC_CLC_DECL_CNFERR;
1162 	}
1163 
1164 	/* Create send and receive buffers */
1165 	if (smc_buf_create(new_smc, true)) {
1166 		if (*local_contact == SMC_FIRST_CONTACT)
1167 			smc_lgr_forget(new_smc->conn.lgr);
1168 		smc_conn_free(&new_smc->conn);
1169 		return SMC_CLC_DECL_MEM;
1170 	}
1171 
1172 	return 0;
1173 }
1174 
1175 /* listen worker: register buffers */
1176 static int smc_listen_rdma_reg(struct smc_sock *new_smc, int local_contact)
1177 {
1178 	struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
1179 
1180 	if (local_contact != SMC_FIRST_CONTACT) {
1181 		if (smc_reg_rmb(link, new_smc->conn.rmb_desc, true))
1182 			return SMC_CLC_DECL_ERR_REGRMB;
1183 	}
1184 	smc_rmb_sync_sg_for_device(&new_smc->conn);
1185 
1186 	return 0;
1187 }
1188 
1189 /* listen worker: finish RDMA setup */
1190 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
1191 				  struct smc_clc_msg_accept_confirm *cclc,
1192 				  int local_contact)
1193 {
1194 	struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
1195 	int reason_code = 0;
1196 
1197 	if (local_contact == SMC_FIRST_CONTACT)
1198 		smc_link_save_peer_info(link, cclc);
1199 
1200 	if (smc_rmb_rtoken_handling(&new_smc->conn, cclc)) {
1201 		reason_code = SMC_CLC_DECL_ERR_RTOK;
1202 		goto decline;
1203 	}
1204 
1205 	if (local_contact == SMC_FIRST_CONTACT) {
1206 		if (smc_ib_ready_link(link)) {
1207 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
1208 			goto decline;
1209 		}
1210 		/* QP confirmation over RoCE fabric */
1211 		reason_code = smc_serv_conf_first_link(new_smc);
1212 		if (reason_code)
1213 			goto decline;
1214 	}
1215 	return 0;
1216 
1217 decline:
1218 	smc_listen_decline(new_smc, reason_code, local_contact);
1219 	return reason_code;
1220 }
1221 
1222 /* setup for RDMA connection of server */
1223 static void smc_listen_work(struct work_struct *work)
1224 {
1225 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
1226 						smc_listen_work);
1227 	struct socket *newclcsock = new_smc->clcsock;
1228 	struct smc_clc_msg_accept_confirm cclc;
1229 	struct smc_clc_msg_proposal *pclc;
1230 	struct smc_ib_device *ibdev;
1231 	bool ism_supported = false;
1232 	struct smcd_dev *ismdev;
1233 	u8 buf[SMC_CLC_MAX_LEN];
1234 	int local_contact = 0;
1235 	unsigned short vlan;
1236 	int reason_code = 0;
1237 	int rc = 0;
1238 	u8 ibport;
1239 
1240 	if (new_smc->use_fallback) {
1241 		smc_listen_out_connected(new_smc);
1242 		return;
1243 	}
1244 
1245 	/* check if peer is smc capable */
1246 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
1247 		new_smc->use_fallback = true;
1248 		new_smc->fallback_rsn = SMC_CLC_DECL_PEERNOSMC;
1249 		smc_listen_out_connected(new_smc);
1250 		return;
1251 	}
1252 
1253 	/* do inband token exchange -
1254 	 * wait for and receive SMC Proposal CLC message
1255 	 */
1256 	pclc = (struct smc_clc_msg_proposal *)&buf;
1257 	reason_code = smc_clc_wait_msg(new_smc, pclc, SMC_CLC_MAX_LEN,
1258 				       SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
1259 	if (reason_code) {
1260 		smc_listen_decline(new_smc, reason_code, 0);
1261 		return;
1262 	}
1263 
1264 	/* IPSec connections opt out of SMC-R optimizations */
1265 	if (using_ipsec(new_smc)) {
1266 		smc_listen_decline(new_smc, SMC_CLC_DECL_IPSEC, 0);
1267 		return;
1268 	}
1269 
1270 	mutex_lock(&smc_server_lgr_pending);
1271 	smc_close_init(new_smc);
1272 	smc_rx_init(new_smc);
1273 	smc_tx_init(new_smc);
1274 
1275 	/* check if ISM is available */
1276 	if ((pclc->hdr.path == SMC_TYPE_D || pclc->hdr.path == SMC_TYPE_B) &&
1277 	    !smc_check_ism(new_smc, &ismdev) &&
1278 	    !smc_listen_ism_init(new_smc, pclc, ismdev, &local_contact)) {
1279 		ism_supported = true;
1280 	}
1281 
1282 	/* check if RDMA is available */
1283 	if (!ism_supported &&
1284 	    ((pclc->hdr.path != SMC_TYPE_R && pclc->hdr.path != SMC_TYPE_B) ||
1285 	     smc_vlan_by_tcpsk(new_smc->clcsock, &vlan) ||
1286 	     smc_check_rdma(new_smc, &ibdev, &ibport, vlan, NULL) ||
1287 	     smc_listen_rdma_check(new_smc, pclc) ||
1288 	     smc_listen_rdma_init(new_smc, pclc, ibdev, ibport,
1289 				  &local_contact) ||
1290 	     smc_listen_rdma_reg(new_smc, local_contact))) {
1291 		/* SMC not supported, decline */
1292 		mutex_unlock(&smc_server_lgr_pending);
1293 		smc_listen_decline(new_smc, SMC_CLC_DECL_MODEUNSUPP,
1294 				   local_contact);
1295 		return;
1296 	}
1297 
1298 	/* send SMC Accept CLC message */
1299 	rc = smc_clc_send_accept(new_smc, local_contact);
1300 	if (rc) {
1301 		mutex_unlock(&smc_server_lgr_pending);
1302 		smc_listen_decline(new_smc, rc, local_contact);
1303 		return;
1304 	}
1305 
1306 	/* SMC-D does not need this lock any more */
1307 	if (ism_supported)
1308 		mutex_unlock(&smc_server_lgr_pending);
1309 
1310 	/* receive SMC Confirm CLC message */
1311 	reason_code = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
1312 				       SMC_CLC_CONFIRM, CLC_WAIT_TIME);
1313 	if (reason_code) {
1314 		if (!ism_supported)
1315 			mutex_unlock(&smc_server_lgr_pending);
1316 		smc_listen_decline(new_smc, reason_code, local_contact);
1317 		return;
1318 	}
1319 
1320 	/* finish worker */
1321 	if (!ism_supported) {
1322 		rc = smc_listen_rdma_finish(new_smc, &cclc, local_contact);
1323 		mutex_unlock(&smc_server_lgr_pending);
1324 		if (rc)
1325 			return;
1326 	}
1327 	smc_conn_save_peer_info(new_smc, &cclc);
1328 	smc_listen_out_connected(new_smc);
1329 }
1330 
1331 static void smc_tcp_listen_work(struct work_struct *work)
1332 {
1333 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
1334 					     tcp_listen_work);
1335 	struct sock *lsk = &lsmc->sk;
1336 	struct smc_sock *new_smc;
1337 	int rc = 0;
1338 
1339 	lock_sock(lsk);
1340 	while (lsk->sk_state == SMC_LISTEN) {
1341 		rc = smc_clcsock_accept(lsmc, &new_smc);
1342 		if (rc)
1343 			goto out;
1344 		if (!new_smc)
1345 			continue;
1346 
1347 		new_smc->listen_smc = lsmc;
1348 		new_smc->use_fallback = lsmc->use_fallback;
1349 		new_smc->fallback_rsn = lsmc->fallback_rsn;
1350 		sock_hold(lsk); /* sock_put in smc_listen_work */
1351 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
1352 		smc_copy_sock_settings_to_smc(new_smc);
1353 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
1354 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
1355 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
1356 		if (!schedule_work(&new_smc->smc_listen_work))
1357 			sock_put(&new_smc->sk);
1358 	}
1359 
1360 out:
1361 	release_sock(lsk);
1362 	sock_put(&lsmc->sk); /* sock_hold in smc_listen */
1363 }
1364 
1365 static int smc_listen(struct socket *sock, int backlog)
1366 {
1367 	struct sock *sk = sock->sk;
1368 	struct smc_sock *smc;
1369 	int rc;
1370 
1371 	smc = smc_sk(sk);
1372 	lock_sock(sk);
1373 
1374 	rc = -EINVAL;
1375 	if ((sk->sk_state != SMC_INIT) && (sk->sk_state != SMC_LISTEN))
1376 		goto out;
1377 
1378 	rc = 0;
1379 	if (sk->sk_state == SMC_LISTEN) {
1380 		sk->sk_max_ack_backlog = backlog;
1381 		goto out;
1382 	}
1383 	/* some socket options are handled in core, so we could not apply
1384 	 * them to the clc socket -- copy smc socket options to clc socket
1385 	 */
1386 	smc_copy_sock_settings_to_clc(smc);
1387 	if (!smc->use_fallback)
1388 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1389 
1390 	rc = kernel_listen(smc->clcsock, backlog);
1391 	if (rc)
1392 		goto out;
1393 	sk->sk_max_ack_backlog = backlog;
1394 	sk->sk_ack_backlog = 0;
1395 	sk->sk_state = SMC_LISTEN;
1396 	sock_hold(sk); /* sock_hold in tcp_listen_worker */
1397 	if (!schedule_work(&smc->tcp_listen_work))
1398 		sock_put(sk);
1399 
1400 out:
1401 	release_sock(sk);
1402 	return rc;
1403 }
1404 
1405 static int smc_accept(struct socket *sock, struct socket *new_sock,
1406 		      int flags, bool kern)
1407 {
1408 	struct sock *sk = sock->sk, *nsk;
1409 	DECLARE_WAITQUEUE(wait, current);
1410 	struct smc_sock *lsmc;
1411 	long timeo;
1412 	int rc = 0;
1413 
1414 	lsmc = smc_sk(sk);
1415 	sock_hold(sk); /* sock_put below */
1416 	lock_sock(sk);
1417 
1418 	if (lsmc->sk.sk_state != SMC_LISTEN) {
1419 		rc = -EINVAL;
1420 		release_sock(sk);
1421 		goto out;
1422 	}
1423 
1424 	/* Wait for an incoming connection */
1425 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1426 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
1427 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1428 		set_current_state(TASK_INTERRUPTIBLE);
1429 		if (!timeo) {
1430 			rc = -EAGAIN;
1431 			break;
1432 		}
1433 		release_sock(sk);
1434 		timeo = schedule_timeout(timeo);
1435 		/* wakeup by sk_data_ready in smc_listen_work() */
1436 		sched_annotate_sleep();
1437 		lock_sock(sk);
1438 		if (signal_pending(current)) {
1439 			rc = sock_intr_errno(timeo);
1440 			break;
1441 		}
1442 	}
1443 	set_current_state(TASK_RUNNING);
1444 	remove_wait_queue(sk_sleep(sk), &wait);
1445 
1446 	if (!rc)
1447 		rc = sock_error(nsk);
1448 	release_sock(sk);
1449 	if (rc)
1450 		goto out;
1451 
1452 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
1453 		/* wait till data arrives on the socket */
1454 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
1455 								MSEC_PER_SEC);
1456 		if (smc_sk(nsk)->use_fallback) {
1457 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
1458 
1459 			lock_sock(clcsk);
1460 			if (skb_queue_empty(&clcsk->sk_receive_queue))
1461 				sk_wait_data(clcsk, &timeo, NULL);
1462 			release_sock(clcsk);
1463 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
1464 			lock_sock(nsk);
1465 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
1466 			release_sock(nsk);
1467 		}
1468 	}
1469 
1470 out:
1471 	sock_put(sk); /* sock_hold above */
1472 	return rc;
1473 }
1474 
1475 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1476 		       int peer)
1477 {
1478 	struct smc_sock *smc;
1479 
1480 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
1481 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
1482 		return -ENOTCONN;
1483 
1484 	smc = smc_sk(sock->sk);
1485 
1486 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
1487 }
1488 
1489 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1490 {
1491 	struct sock *sk = sock->sk;
1492 	struct smc_sock *smc;
1493 	int rc = -EPIPE;
1494 
1495 	smc = smc_sk(sk);
1496 	lock_sock(sk);
1497 	if ((sk->sk_state != SMC_ACTIVE) &&
1498 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1499 	    (sk->sk_state != SMC_INIT))
1500 		goto out;
1501 
1502 	if (msg->msg_flags & MSG_FASTOPEN) {
1503 		if (sk->sk_state == SMC_INIT) {
1504 			smc->use_fallback = true;
1505 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1506 		} else {
1507 			rc = -EINVAL;
1508 			goto out;
1509 		}
1510 	}
1511 
1512 	if (smc->use_fallback)
1513 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
1514 	else
1515 		rc = smc_tx_sendmsg(smc, msg, len);
1516 out:
1517 	release_sock(sk);
1518 	return rc;
1519 }
1520 
1521 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1522 		       int flags)
1523 {
1524 	struct sock *sk = sock->sk;
1525 	struct smc_sock *smc;
1526 	int rc = -ENOTCONN;
1527 
1528 	smc = smc_sk(sk);
1529 	lock_sock(sk);
1530 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
1531 		/* socket was connected before, no more data to read */
1532 		rc = 0;
1533 		goto out;
1534 	}
1535 	if ((sk->sk_state == SMC_INIT) ||
1536 	    (sk->sk_state == SMC_LISTEN) ||
1537 	    (sk->sk_state == SMC_CLOSED))
1538 		goto out;
1539 
1540 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1541 		rc = 0;
1542 		goto out;
1543 	}
1544 
1545 	if (smc->use_fallback) {
1546 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
1547 	} else {
1548 		msg->msg_namelen = 0;
1549 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
1550 	}
1551 
1552 out:
1553 	release_sock(sk);
1554 	return rc;
1555 }
1556 
1557 static __poll_t smc_accept_poll(struct sock *parent)
1558 {
1559 	struct smc_sock *isk = smc_sk(parent);
1560 	__poll_t mask = 0;
1561 
1562 	spin_lock(&isk->accept_q_lock);
1563 	if (!list_empty(&isk->accept_q))
1564 		mask = EPOLLIN | EPOLLRDNORM;
1565 	spin_unlock(&isk->accept_q_lock);
1566 
1567 	return mask;
1568 }
1569 
1570 static __poll_t smc_poll(struct file *file, struct socket *sock,
1571 			     poll_table *wait)
1572 {
1573 	struct sock *sk = sock->sk;
1574 	__poll_t mask = 0;
1575 	struct smc_sock *smc;
1576 
1577 	if (!sk)
1578 		return EPOLLNVAL;
1579 
1580 	smc = smc_sk(sock->sk);
1581 	if (smc->use_fallback) {
1582 		/* delegate to CLC child sock */
1583 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
1584 		sk->sk_err = smc->clcsock->sk->sk_err;
1585 		if (sk->sk_err)
1586 			mask |= EPOLLERR;
1587 	} else {
1588 		if (sk->sk_state != SMC_CLOSED)
1589 			sock_poll_wait(file, sock, wait);
1590 		if (sk->sk_err)
1591 			mask |= EPOLLERR;
1592 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1593 		    (sk->sk_state == SMC_CLOSED))
1594 			mask |= EPOLLHUP;
1595 		if (sk->sk_state == SMC_LISTEN) {
1596 			/* woken up by sk_data_ready in smc_listen_work() */
1597 			mask = smc_accept_poll(sk);
1598 		} else {
1599 			if (atomic_read(&smc->conn.sndbuf_space) ||
1600 			    sk->sk_shutdown & SEND_SHUTDOWN) {
1601 				mask |= EPOLLOUT | EPOLLWRNORM;
1602 			} else {
1603 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1604 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1605 			}
1606 			if (atomic_read(&smc->conn.bytes_to_rcv))
1607 				mask |= EPOLLIN | EPOLLRDNORM;
1608 			if (sk->sk_shutdown & RCV_SHUTDOWN)
1609 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
1610 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
1611 				mask |= EPOLLIN;
1612 			if (smc->conn.urg_state == SMC_URG_VALID)
1613 				mask |= EPOLLPRI;
1614 		}
1615 	}
1616 
1617 	return mask;
1618 }
1619 
1620 static int smc_shutdown(struct socket *sock, int how)
1621 {
1622 	struct sock *sk = sock->sk;
1623 	struct smc_sock *smc;
1624 	int rc = -EINVAL;
1625 	int rc1 = 0;
1626 
1627 	smc = smc_sk(sk);
1628 
1629 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
1630 		return rc;
1631 
1632 	lock_sock(sk);
1633 
1634 	rc = -ENOTCONN;
1635 	if ((sk->sk_state != SMC_ACTIVE) &&
1636 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
1637 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
1638 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1639 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
1640 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
1641 		goto out;
1642 	if (smc->use_fallback) {
1643 		rc = kernel_sock_shutdown(smc->clcsock, how);
1644 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
1645 		if (sk->sk_shutdown == SHUTDOWN_MASK)
1646 			sk->sk_state = SMC_CLOSED;
1647 		goto out;
1648 	}
1649 	switch (how) {
1650 	case SHUT_RDWR:		/* shutdown in both directions */
1651 		rc = smc_close_active(smc);
1652 		break;
1653 	case SHUT_WR:
1654 		rc = smc_close_shutdown_write(smc);
1655 		break;
1656 	case SHUT_RD:
1657 		rc = 0;
1658 		/* nothing more to do because peer is not involved */
1659 		break;
1660 	}
1661 	if (smc->clcsock)
1662 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
1663 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
1664 	sk->sk_shutdown |= how + 1;
1665 
1666 out:
1667 	release_sock(sk);
1668 	return rc ? rc : rc1;
1669 }
1670 
1671 static int smc_setsockopt(struct socket *sock, int level, int optname,
1672 			  char __user *optval, unsigned int optlen)
1673 {
1674 	struct sock *sk = sock->sk;
1675 	struct smc_sock *smc;
1676 	int val, rc;
1677 
1678 	smc = smc_sk(sk);
1679 
1680 	/* generic setsockopts reaching us here always apply to the
1681 	 * CLC socket
1682 	 */
1683 	rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
1684 					   optval, optlen);
1685 	if (smc->clcsock->sk->sk_err) {
1686 		sk->sk_err = smc->clcsock->sk->sk_err;
1687 		sk->sk_error_report(sk);
1688 	}
1689 	if (rc)
1690 		return rc;
1691 
1692 	if (optlen < sizeof(int))
1693 		return -EINVAL;
1694 	if (get_user(val, (int __user *)optval))
1695 		return -EFAULT;
1696 
1697 	lock_sock(sk);
1698 	switch (optname) {
1699 	case TCP_ULP:
1700 	case TCP_FASTOPEN:
1701 	case TCP_FASTOPEN_CONNECT:
1702 	case TCP_FASTOPEN_KEY:
1703 	case TCP_FASTOPEN_NO_COOKIE:
1704 		/* option not supported by SMC */
1705 		if (sk->sk_state == SMC_INIT) {
1706 			smc->use_fallback = true;
1707 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1708 		} else {
1709 			if (!smc->use_fallback)
1710 				rc = -EINVAL;
1711 		}
1712 		break;
1713 	case TCP_NODELAY:
1714 		if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1715 			if (val && !smc->use_fallback)
1716 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1717 						 0);
1718 		}
1719 		break;
1720 	case TCP_CORK:
1721 		if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
1722 			if (!val && !smc->use_fallback)
1723 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1724 						 0);
1725 		}
1726 		break;
1727 	case TCP_DEFER_ACCEPT:
1728 		smc->sockopt_defer_accept = val;
1729 		break;
1730 	default:
1731 		break;
1732 	}
1733 	release_sock(sk);
1734 
1735 	return rc;
1736 }
1737 
1738 static int smc_getsockopt(struct socket *sock, int level, int optname,
1739 			  char __user *optval, int __user *optlen)
1740 {
1741 	struct smc_sock *smc;
1742 
1743 	smc = smc_sk(sock->sk);
1744 	/* socket options apply to the CLC socket */
1745 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
1746 					     optval, optlen);
1747 }
1748 
1749 static int smc_ioctl(struct socket *sock, unsigned int cmd,
1750 		     unsigned long arg)
1751 {
1752 	union smc_host_cursor cons, urg;
1753 	struct smc_connection *conn;
1754 	struct smc_sock *smc;
1755 	int answ;
1756 
1757 	smc = smc_sk(sock->sk);
1758 	conn = &smc->conn;
1759 	lock_sock(&smc->sk);
1760 	if (smc->use_fallback) {
1761 		if (!smc->clcsock) {
1762 			release_sock(&smc->sk);
1763 			return -EBADF;
1764 		}
1765 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
1766 		release_sock(&smc->sk);
1767 		return answ;
1768 	}
1769 	switch (cmd) {
1770 	case SIOCINQ: /* same as FIONREAD */
1771 		if (smc->sk.sk_state == SMC_LISTEN) {
1772 			release_sock(&smc->sk);
1773 			return -EINVAL;
1774 		}
1775 		if (smc->sk.sk_state == SMC_INIT ||
1776 		    smc->sk.sk_state == SMC_CLOSED)
1777 			answ = 0;
1778 		else
1779 			answ = atomic_read(&smc->conn.bytes_to_rcv);
1780 		break;
1781 	case SIOCOUTQ:
1782 		/* output queue size (not send + not acked) */
1783 		if (smc->sk.sk_state == SMC_LISTEN) {
1784 			release_sock(&smc->sk);
1785 			return -EINVAL;
1786 		}
1787 		if (smc->sk.sk_state == SMC_INIT ||
1788 		    smc->sk.sk_state == SMC_CLOSED)
1789 			answ = 0;
1790 		else
1791 			answ = smc->conn.sndbuf_desc->len -
1792 					atomic_read(&smc->conn.sndbuf_space);
1793 		break;
1794 	case SIOCOUTQNSD:
1795 		/* output queue size (not send only) */
1796 		if (smc->sk.sk_state == SMC_LISTEN) {
1797 			release_sock(&smc->sk);
1798 			return -EINVAL;
1799 		}
1800 		if (smc->sk.sk_state == SMC_INIT ||
1801 		    smc->sk.sk_state == SMC_CLOSED)
1802 			answ = 0;
1803 		else
1804 			answ = smc_tx_prepared_sends(&smc->conn);
1805 		break;
1806 	case SIOCATMARK:
1807 		if (smc->sk.sk_state == SMC_LISTEN) {
1808 			release_sock(&smc->sk);
1809 			return -EINVAL;
1810 		}
1811 		if (smc->sk.sk_state == SMC_INIT ||
1812 		    smc->sk.sk_state == SMC_CLOSED) {
1813 			answ = 0;
1814 		} else {
1815 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
1816 			smc_curs_copy(&urg, &conn->urg_curs, conn);
1817 			answ = smc_curs_diff(conn->rmb_desc->len,
1818 					     &cons, &urg) == 1;
1819 		}
1820 		break;
1821 	default:
1822 		release_sock(&smc->sk);
1823 		return -ENOIOCTLCMD;
1824 	}
1825 	release_sock(&smc->sk);
1826 
1827 	return put_user(answ, (int __user *)arg);
1828 }
1829 
1830 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
1831 			    int offset, size_t size, int flags)
1832 {
1833 	struct sock *sk = sock->sk;
1834 	struct smc_sock *smc;
1835 	int rc = -EPIPE;
1836 
1837 	smc = smc_sk(sk);
1838 	lock_sock(sk);
1839 	if (sk->sk_state != SMC_ACTIVE) {
1840 		release_sock(sk);
1841 		goto out;
1842 	}
1843 	release_sock(sk);
1844 	if (smc->use_fallback)
1845 		rc = kernel_sendpage(smc->clcsock, page, offset,
1846 				     size, flags);
1847 	else
1848 		rc = sock_no_sendpage(sock, page, offset, size, flags);
1849 
1850 out:
1851 	return rc;
1852 }
1853 
1854 /* Map the affected portions of the rmbe into an spd, note the number of bytes
1855  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
1856  * updates till whenever a respective page has been fully processed.
1857  * Note that subsequent recv() calls have to wait till all splice() processing
1858  * completed.
1859  */
1860 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
1861 			       struct pipe_inode_info *pipe, size_t len,
1862 			       unsigned int flags)
1863 {
1864 	struct sock *sk = sock->sk;
1865 	struct smc_sock *smc;
1866 	int rc = -ENOTCONN;
1867 
1868 	smc = smc_sk(sk);
1869 	lock_sock(sk);
1870 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
1871 		/* socket was connected before, no more data to read */
1872 		rc = 0;
1873 		goto out;
1874 	}
1875 	if (sk->sk_state == SMC_INIT ||
1876 	    sk->sk_state == SMC_LISTEN ||
1877 	    sk->sk_state == SMC_CLOSED)
1878 		goto out;
1879 
1880 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1881 		rc = 0;
1882 		goto out;
1883 	}
1884 
1885 	if (smc->use_fallback) {
1886 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
1887 						    pipe, len, flags);
1888 	} else {
1889 		if (*ppos) {
1890 			rc = -ESPIPE;
1891 			goto out;
1892 		}
1893 		if (flags & SPLICE_F_NONBLOCK)
1894 			flags = MSG_DONTWAIT;
1895 		else
1896 			flags = 0;
1897 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
1898 	}
1899 out:
1900 	release_sock(sk);
1901 
1902 	return rc;
1903 }
1904 
1905 /* must look like tcp */
1906 static const struct proto_ops smc_sock_ops = {
1907 	.family		= PF_SMC,
1908 	.owner		= THIS_MODULE,
1909 	.release	= smc_release,
1910 	.bind		= smc_bind,
1911 	.connect	= smc_connect,
1912 	.socketpair	= sock_no_socketpair,
1913 	.accept		= smc_accept,
1914 	.getname	= smc_getname,
1915 	.poll		= smc_poll,
1916 	.ioctl		= smc_ioctl,
1917 	.listen		= smc_listen,
1918 	.shutdown	= smc_shutdown,
1919 	.setsockopt	= smc_setsockopt,
1920 	.getsockopt	= smc_getsockopt,
1921 	.sendmsg	= smc_sendmsg,
1922 	.recvmsg	= smc_recvmsg,
1923 	.mmap		= sock_no_mmap,
1924 	.sendpage	= smc_sendpage,
1925 	.splice_read	= smc_splice_read,
1926 };
1927 
1928 static int smc_create(struct net *net, struct socket *sock, int protocol,
1929 		      int kern)
1930 {
1931 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
1932 	struct smc_sock *smc;
1933 	struct sock *sk;
1934 	int rc;
1935 
1936 	rc = -ESOCKTNOSUPPORT;
1937 	if (sock->type != SOCK_STREAM)
1938 		goto out;
1939 
1940 	rc = -EPROTONOSUPPORT;
1941 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
1942 		goto out;
1943 
1944 	rc = -ENOBUFS;
1945 	sock->ops = &smc_sock_ops;
1946 	sk = smc_sock_alloc(net, sock, protocol);
1947 	if (!sk)
1948 		goto out;
1949 
1950 	/* create internal TCP socket for CLC handshake and fallback */
1951 	smc = smc_sk(sk);
1952 	smc->use_fallback = false; /* assume rdma capability first */
1953 	smc->fallback_rsn = 0;
1954 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
1955 			      &smc->clcsock);
1956 	if (rc) {
1957 		sk_common_release(sk);
1958 		goto out;
1959 	}
1960 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
1961 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
1962 
1963 out:
1964 	return rc;
1965 }
1966 
1967 static const struct net_proto_family smc_sock_family_ops = {
1968 	.family	= PF_SMC,
1969 	.owner	= THIS_MODULE,
1970 	.create	= smc_create,
1971 };
1972 
1973 unsigned int smc_net_id;
1974 
1975 static __net_init int smc_net_init(struct net *net)
1976 {
1977 	return smc_pnet_net_init(net);
1978 }
1979 
1980 static void __net_exit smc_net_exit(struct net *net)
1981 {
1982 	smc_pnet_net_exit(net);
1983 }
1984 
1985 static struct pernet_operations smc_net_ops = {
1986 	.init = smc_net_init,
1987 	.exit = smc_net_exit,
1988 	.id   = &smc_net_id,
1989 	.size = sizeof(struct smc_net),
1990 };
1991 
1992 static int __init smc_init(void)
1993 {
1994 	int rc;
1995 
1996 	rc = register_pernet_subsys(&smc_net_ops);
1997 	if (rc)
1998 		return rc;
1999 
2000 	rc = smc_pnet_init();
2001 	if (rc)
2002 		return rc;
2003 
2004 	rc = smc_llc_init();
2005 	if (rc) {
2006 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
2007 		goto out_pnet;
2008 	}
2009 
2010 	rc = smc_cdc_init();
2011 	if (rc) {
2012 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
2013 		goto out_pnet;
2014 	}
2015 
2016 	rc = proto_register(&smc_proto, 1);
2017 	if (rc) {
2018 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
2019 		goto out_pnet;
2020 	}
2021 
2022 	rc = proto_register(&smc_proto6, 1);
2023 	if (rc) {
2024 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
2025 		goto out_proto;
2026 	}
2027 
2028 	rc = sock_register(&smc_sock_family_ops);
2029 	if (rc) {
2030 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
2031 		goto out_proto6;
2032 	}
2033 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
2034 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
2035 
2036 	rc = smc_ib_register_client();
2037 	if (rc) {
2038 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
2039 		goto out_sock;
2040 	}
2041 
2042 	static_branch_enable(&tcp_have_smc);
2043 	return 0;
2044 
2045 out_sock:
2046 	sock_unregister(PF_SMC);
2047 out_proto6:
2048 	proto_unregister(&smc_proto6);
2049 out_proto:
2050 	proto_unregister(&smc_proto);
2051 out_pnet:
2052 	smc_pnet_exit();
2053 	return rc;
2054 }
2055 
2056 static void __exit smc_exit(void)
2057 {
2058 	smc_core_exit();
2059 	static_branch_disable(&tcp_have_smc);
2060 	smc_ib_unregister_client();
2061 	sock_unregister(PF_SMC);
2062 	proto_unregister(&smc_proto6);
2063 	proto_unregister(&smc_proto);
2064 	smc_pnet_exit();
2065 	unregister_pernet_subsys(&smc_net_ops);
2066 }
2067 
2068 module_init(smc_init);
2069 module_exit(smc_exit);
2070 
2071 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
2072 MODULE_DESCRIPTION("smc socket address family");
2073 MODULE_LICENSE("GPL");
2074 MODULE_ALIAS_NETPROTO(PF_SMC);
2075