xref: /linux/net/smc/af_smc.c (revision 37744feebc086908fd89760650f458ab19071750)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
4  *
5  *  AF_SMC protocol family socket handler keeping the AF_INET sock address type
6  *  applies to SOCK_STREAM sockets only
7  *  offers an alternative communication option for TCP-protocol sockets
8  *  applicable with RoCE-cards only
9  *
10  *  Initial restrictions:
11  *    - support for alternate links postponed
12  *
13  *  Copyright IBM Corp. 2016, 2018
14  *
15  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
16  *              based on prototype from Frank Blaschka
17  */
18 
19 #define KMSG_COMPONENT "smc"
20 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
21 
22 #include <linux/module.h>
23 #include <linux/socket.h>
24 #include <linux/workqueue.h>
25 #include <linux/in.h>
26 #include <linux/sched/signal.h>
27 #include <linux/if_vlan.h>
28 #include <linux/rcupdate_wait.h>
29 
30 #include <net/sock.h>
31 #include <net/tcp.h>
32 #include <net/smc.h>
33 #include <asm/ioctls.h>
34 
35 #include <net/net_namespace.h>
36 #include <net/netns/generic.h>
37 #include "smc_netns.h"
38 
39 #include "smc.h"
40 #include "smc_clc.h"
41 #include "smc_llc.h"
42 #include "smc_cdc.h"
43 #include "smc_core.h"
44 #include "smc_ib.h"
45 #include "smc_ism.h"
46 #include "smc_pnet.h"
47 #include "smc_tx.h"
48 #include "smc_rx.h"
49 #include "smc_close.h"
50 
51 static DEFINE_MUTEX(smc_server_lgr_pending);	/* serialize link group
52 						 * creation on server
53 						 */
54 static DEFINE_MUTEX(smc_client_lgr_pending);	/* serialize link group
55 						 * creation on client
56 						 */
57 
58 static void smc_tcp_listen_work(struct work_struct *);
59 static void smc_connect_work(struct work_struct *);
60 
61 static void smc_set_keepalive(struct sock *sk, int val)
62 {
63 	struct smc_sock *smc = smc_sk(sk);
64 
65 	smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
66 }
67 
68 static struct smc_hashinfo smc_v4_hashinfo = {
69 	.lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
70 };
71 
72 static struct smc_hashinfo smc_v6_hashinfo = {
73 	.lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
74 };
75 
76 int smc_hash_sk(struct sock *sk)
77 {
78 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
79 	struct hlist_head *head;
80 
81 	head = &h->ht;
82 
83 	write_lock_bh(&h->lock);
84 	sk_add_node(sk, head);
85 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
86 	write_unlock_bh(&h->lock);
87 
88 	return 0;
89 }
90 EXPORT_SYMBOL_GPL(smc_hash_sk);
91 
92 void smc_unhash_sk(struct sock *sk)
93 {
94 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
95 
96 	write_lock_bh(&h->lock);
97 	if (sk_del_node_init(sk))
98 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
99 	write_unlock_bh(&h->lock);
100 }
101 EXPORT_SYMBOL_GPL(smc_unhash_sk);
102 
103 struct proto smc_proto = {
104 	.name		= "SMC",
105 	.owner		= THIS_MODULE,
106 	.keepalive	= smc_set_keepalive,
107 	.hash		= smc_hash_sk,
108 	.unhash		= smc_unhash_sk,
109 	.obj_size	= sizeof(struct smc_sock),
110 	.h.smc_hash	= &smc_v4_hashinfo,
111 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
112 };
113 EXPORT_SYMBOL_GPL(smc_proto);
114 
115 struct proto smc_proto6 = {
116 	.name		= "SMC6",
117 	.owner		= THIS_MODULE,
118 	.keepalive	= smc_set_keepalive,
119 	.hash		= smc_hash_sk,
120 	.unhash		= smc_unhash_sk,
121 	.obj_size	= sizeof(struct smc_sock),
122 	.h.smc_hash	= &smc_v6_hashinfo,
123 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
124 };
125 EXPORT_SYMBOL_GPL(smc_proto6);
126 
127 static void smc_restore_fallback_changes(struct smc_sock *smc)
128 {
129 	smc->clcsock->file->private_data = smc->sk.sk_socket;
130 	smc->clcsock->file = NULL;
131 }
132 
133 static int __smc_release(struct smc_sock *smc)
134 {
135 	struct sock *sk = &smc->sk;
136 	int rc = 0;
137 
138 	if (!smc->use_fallback) {
139 		rc = smc_close_active(smc);
140 		sock_set_flag(sk, SOCK_DEAD);
141 		sk->sk_shutdown |= SHUTDOWN_MASK;
142 	} else {
143 		if (sk->sk_state != SMC_LISTEN && sk->sk_state != SMC_INIT)
144 			sock_put(sk); /* passive closing */
145 		if (sk->sk_state == SMC_LISTEN) {
146 			/* wake up clcsock accept */
147 			rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
148 		}
149 		sk->sk_state = SMC_CLOSED;
150 		sk->sk_state_change(sk);
151 		smc_restore_fallback_changes(smc);
152 	}
153 
154 	sk->sk_prot->unhash(sk);
155 
156 	if (sk->sk_state == SMC_CLOSED) {
157 		if (smc->clcsock) {
158 			release_sock(sk);
159 			smc_clcsock_release(smc);
160 			lock_sock(sk);
161 		}
162 		if (!smc->use_fallback)
163 			smc_conn_free(&smc->conn);
164 	}
165 
166 	return rc;
167 }
168 
169 static int smc_release(struct socket *sock)
170 {
171 	struct sock *sk = sock->sk;
172 	struct smc_sock *smc;
173 	int rc = 0;
174 
175 	if (!sk)
176 		goto out;
177 
178 	sock_hold(sk); /* sock_put below */
179 	smc = smc_sk(sk);
180 
181 	/* cleanup for a dangling non-blocking connect */
182 	if (smc->connect_nonblock && sk->sk_state == SMC_INIT)
183 		tcp_abort(smc->clcsock->sk, ECONNABORTED);
184 	flush_work(&smc->connect_work);
185 
186 	if (sk->sk_state == SMC_LISTEN)
187 		/* smc_close_non_accepted() is called and acquires
188 		 * sock lock for child sockets again
189 		 */
190 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
191 	else
192 		lock_sock(sk);
193 
194 	rc = __smc_release(smc);
195 
196 	/* detach socket */
197 	sock_orphan(sk);
198 	sock->sk = NULL;
199 	release_sock(sk);
200 
201 	sock_put(sk); /* sock_hold above */
202 	sock_put(sk); /* final sock_put */
203 out:
204 	return rc;
205 }
206 
207 static void smc_destruct(struct sock *sk)
208 {
209 	if (sk->sk_state != SMC_CLOSED)
210 		return;
211 	if (!sock_flag(sk, SOCK_DEAD))
212 		return;
213 
214 	sk_refcnt_debug_dec(sk);
215 }
216 
217 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
218 				   int protocol)
219 {
220 	struct smc_sock *smc;
221 	struct proto *prot;
222 	struct sock *sk;
223 
224 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
225 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
226 	if (!sk)
227 		return NULL;
228 
229 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
230 	sk->sk_state = SMC_INIT;
231 	sk->sk_destruct = smc_destruct;
232 	sk->sk_protocol = protocol;
233 	smc = smc_sk(sk);
234 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
235 	INIT_WORK(&smc->connect_work, smc_connect_work);
236 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
237 	INIT_LIST_HEAD(&smc->accept_q);
238 	spin_lock_init(&smc->accept_q_lock);
239 	spin_lock_init(&smc->conn.send_lock);
240 	sk->sk_prot->hash(sk);
241 	sk_refcnt_debug_inc(sk);
242 	mutex_init(&smc->clcsock_release_lock);
243 
244 	return sk;
245 }
246 
247 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
248 		    int addr_len)
249 {
250 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
251 	struct sock *sk = sock->sk;
252 	struct smc_sock *smc;
253 	int rc;
254 
255 	smc = smc_sk(sk);
256 
257 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
258 	rc = -EINVAL;
259 	if (addr_len < sizeof(struct sockaddr_in))
260 		goto out;
261 
262 	rc = -EAFNOSUPPORT;
263 	if (addr->sin_family != AF_INET &&
264 	    addr->sin_family != AF_INET6 &&
265 	    addr->sin_family != AF_UNSPEC)
266 		goto out;
267 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
268 	if (addr->sin_family == AF_UNSPEC &&
269 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
270 		goto out;
271 
272 	lock_sock(sk);
273 
274 	/* Check if socket is already active */
275 	rc = -EINVAL;
276 	if (sk->sk_state != SMC_INIT || smc->connect_nonblock)
277 		goto out_rel;
278 
279 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
280 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
281 
282 out_rel:
283 	release_sock(sk);
284 out:
285 	return rc;
286 }
287 
288 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
289 				   unsigned long mask)
290 {
291 	/* options we don't get control via setsockopt for */
292 	nsk->sk_type = osk->sk_type;
293 	nsk->sk_sndbuf = osk->sk_sndbuf;
294 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
295 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
296 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
297 	nsk->sk_mark = osk->sk_mark;
298 	nsk->sk_priority = osk->sk_priority;
299 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
300 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
301 	nsk->sk_err = osk->sk_err;
302 
303 	nsk->sk_flags &= ~mask;
304 	nsk->sk_flags |= osk->sk_flags & mask;
305 }
306 
307 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
308 			     (1UL << SOCK_KEEPOPEN) | \
309 			     (1UL << SOCK_LINGER) | \
310 			     (1UL << SOCK_BROADCAST) | \
311 			     (1UL << SOCK_TIMESTAMP) | \
312 			     (1UL << SOCK_DBG) | \
313 			     (1UL << SOCK_RCVTSTAMP) | \
314 			     (1UL << SOCK_RCVTSTAMPNS) | \
315 			     (1UL << SOCK_LOCALROUTE) | \
316 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
317 			     (1UL << SOCK_RXQ_OVFL) | \
318 			     (1UL << SOCK_WIFI_STATUS) | \
319 			     (1UL << SOCK_NOFCS) | \
320 			     (1UL << SOCK_FILTER_LOCKED) | \
321 			     (1UL << SOCK_TSTAMP_NEW))
322 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
323  * clc socket (since smc is not called for these options from net/core)
324  */
325 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
326 {
327 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
328 }
329 
330 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
331 			     (1UL << SOCK_KEEPOPEN) | \
332 			     (1UL << SOCK_LINGER) | \
333 			     (1UL << SOCK_DBG))
334 /* copy only settings and flags relevant for smc from clc to smc socket */
335 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
336 {
337 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
338 }
339 
340 /* register a new rmb, send confirm_rkey msg to register with peer */
341 static int smc_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc,
342 		       bool conf_rkey)
343 {
344 	if (!rmb_desc->wr_reg) {
345 		/* register memory region for new rmb */
346 		if (smc_wr_reg_send(link, rmb_desc->mr_rx[SMC_SINGLE_LINK])) {
347 			rmb_desc->regerr = 1;
348 			return -EFAULT;
349 		}
350 		rmb_desc->wr_reg = 1;
351 	}
352 	if (!conf_rkey)
353 		return 0;
354 	/* exchange confirm_rkey msg with peer */
355 	if (smc_llc_do_confirm_rkey(link, rmb_desc)) {
356 		rmb_desc->regerr = 1;
357 		return -EFAULT;
358 	}
359 	return 0;
360 }
361 
362 static int smc_clnt_conf_first_link(struct smc_sock *smc)
363 {
364 	struct net *net = sock_net(smc->clcsock->sk);
365 	struct smc_link_group *lgr = smc->conn.lgr;
366 	struct smc_link *link;
367 	int rest;
368 	int rc;
369 
370 	link = &lgr->lnk[SMC_SINGLE_LINK];
371 	/* receive CONFIRM LINK request from server over RoCE fabric */
372 	rest = wait_for_completion_interruptible_timeout(
373 		&link->llc_confirm,
374 		SMC_LLC_WAIT_FIRST_TIME);
375 	if (rest <= 0) {
376 		struct smc_clc_msg_decline dclc;
377 
378 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
379 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
380 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
381 	}
382 
383 	if (link->llc_confirm_rc)
384 		return SMC_CLC_DECL_RMBE_EC;
385 
386 	rc = smc_ib_modify_qp_rts(link);
387 	if (rc)
388 		return SMC_CLC_DECL_ERR_RDYLNK;
389 
390 	smc_wr_remember_qp_attr(link);
391 
392 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
393 		return SMC_CLC_DECL_ERR_REGRMB;
394 
395 	/* send CONFIRM LINK response over RoCE fabric */
396 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
397 	if (rc < 0)
398 		return SMC_CLC_DECL_TIMEOUT_CL;
399 
400 	/* receive ADD LINK request from server over RoCE fabric */
401 	rest = wait_for_completion_interruptible_timeout(&link->llc_add,
402 							 SMC_LLC_WAIT_TIME);
403 	if (rest <= 0) {
404 		struct smc_clc_msg_decline dclc;
405 
406 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
407 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
408 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_AL : rc;
409 	}
410 
411 	/* send add link reject message, only one link supported for now */
412 	rc = smc_llc_send_add_link(link,
413 				   link->smcibdev->mac[link->ibport - 1],
414 				   link->gid, SMC_LLC_RESP);
415 	if (rc < 0)
416 		return SMC_CLC_DECL_TIMEOUT_AL;
417 
418 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
419 
420 	return 0;
421 }
422 
423 static void smcr_conn_save_peer_info(struct smc_sock *smc,
424 				     struct smc_clc_msg_accept_confirm *clc)
425 {
426 	int bufsize = smc_uncompress_bufsize(clc->rmbe_size);
427 
428 	smc->conn.peer_rmbe_idx = clc->rmbe_idx;
429 	smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
430 	smc->conn.peer_rmbe_size = bufsize;
431 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
432 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
433 }
434 
435 static void smcd_conn_save_peer_info(struct smc_sock *smc,
436 				     struct smc_clc_msg_accept_confirm *clc)
437 {
438 	int bufsize = smc_uncompress_bufsize(clc->dmbe_size);
439 
440 	smc->conn.peer_rmbe_idx = clc->dmbe_idx;
441 	smc->conn.peer_token = clc->token;
442 	/* msg header takes up space in the buffer */
443 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
444 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
445 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
446 }
447 
448 static void smc_conn_save_peer_info(struct smc_sock *smc,
449 				    struct smc_clc_msg_accept_confirm *clc)
450 {
451 	if (smc->conn.lgr->is_smcd)
452 		smcd_conn_save_peer_info(smc, clc);
453 	else
454 		smcr_conn_save_peer_info(smc, clc);
455 }
456 
457 static void smc_link_save_peer_info(struct smc_link *link,
458 				    struct smc_clc_msg_accept_confirm *clc)
459 {
460 	link->peer_qpn = ntoh24(clc->qpn);
461 	memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
462 	memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
463 	link->peer_psn = ntoh24(clc->psn);
464 	link->peer_mtu = clc->qp_mtu;
465 }
466 
467 static void smc_switch_to_fallback(struct smc_sock *smc)
468 {
469 	smc->use_fallback = true;
470 	if (smc->sk.sk_socket && smc->sk.sk_socket->file) {
471 		smc->clcsock->file = smc->sk.sk_socket->file;
472 		smc->clcsock->file->private_data = smc->clcsock;
473 		smc->clcsock->wq.fasync_list =
474 			smc->sk.sk_socket->wq.fasync_list;
475 	}
476 }
477 
478 /* fall back during connect */
479 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
480 {
481 	smc_switch_to_fallback(smc);
482 	smc->fallback_rsn = reason_code;
483 	smc_copy_sock_settings_to_clc(smc);
484 	smc->connect_nonblock = 0;
485 	if (smc->sk.sk_state == SMC_INIT)
486 		smc->sk.sk_state = SMC_ACTIVE;
487 	return 0;
488 }
489 
490 /* decline and fall back during connect */
491 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code)
492 {
493 	int rc;
494 
495 	if (reason_code < 0) { /* error, fallback is not possible */
496 		if (smc->sk.sk_state == SMC_INIT)
497 			sock_put(&smc->sk); /* passive closing */
498 		return reason_code;
499 	}
500 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
501 		rc = smc_clc_send_decline(smc, reason_code);
502 		if (rc < 0) {
503 			if (smc->sk.sk_state == SMC_INIT)
504 				sock_put(&smc->sk); /* passive closing */
505 			return rc;
506 		}
507 	}
508 	return smc_connect_fallback(smc, reason_code);
509 }
510 
511 /* abort connecting */
512 static int smc_connect_abort(struct smc_sock *smc, int reason_code,
513 			     int local_contact)
514 {
515 	bool is_smcd = smc->conn.lgr->is_smcd;
516 
517 	if (local_contact == SMC_FIRST_CONTACT)
518 		smc_lgr_cleanup_early(&smc->conn);
519 	else
520 		smc_conn_free(&smc->conn);
521 	if (is_smcd)
522 		/* there is only one lgr role for SMC-D; use server lock */
523 		mutex_unlock(&smc_server_lgr_pending);
524 	else
525 		mutex_unlock(&smc_client_lgr_pending);
526 
527 	smc->connect_nonblock = 0;
528 	return reason_code;
529 }
530 
531 /* check if there is a rdma device available for this connection. */
532 /* called for connect and listen */
533 static int smc_find_rdma_device(struct smc_sock *smc, struct smc_init_info *ini)
534 {
535 	/* PNET table look up: search active ib_device and port
536 	 * within same PNETID that also contains the ethernet device
537 	 * used for the internal TCP socket
538 	 */
539 	smc_pnet_find_roce_resource(smc->clcsock->sk, ini);
540 	if (!ini->ib_dev)
541 		return SMC_CLC_DECL_NOSMCRDEV;
542 	return 0;
543 }
544 
545 /* check if there is an ISM device available for this connection. */
546 /* called for connect and listen */
547 static int smc_find_ism_device(struct smc_sock *smc, struct smc_init_info *ini)
548 {
549 	/* Find ISM device with same PNETID as connecting interface  */
550 	smc_pnet_find_ism_resource(smc->clcsock->sk, ini);
551 	if (!ini->ism_dev)
552 		return SMC_CLC_DECL_NOSMCDDEV;
553 	return 0;
554 }
555 
556 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
557 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
558 				      struct smc_init_info *ini)
559 {
560 	if (ini->vlan_id && smc_ism_get_vlan(ini->ism_dev, ini->vlan_id))
561 		return SMC_CLC_DECL_ISMVLANERR;
562 	return 0;
563 }
564 
565 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
566  * used, the VLAN ID will be registered again during the connection setup.
567  */
568 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc, bool is_smcd,
569 					struct smc_init_info *ini)
570 {
571 	if (!is_smcd)
572 		return 0;
573 	if (ini->vlan_id && smc_ism_put_vlan(ini->ism_dev, ini->vlan_id))
574 		return SMC_CLC_DECL_CNFERR;
575 	return 0;
576 }
577 
578 /* CLC handshake during connect */
579 static int smc_connect_clc(struct smc_sock *smc, int smc_type,
580 			   struct smc_clc_msg_accept_confirm *aclc,
581 			   struct smc_init_info *ini)
582 {
583 	int rc = 0;
584 
585 	/* do inband token exchange */
586 	rc = smc_clc_send_proposal(smc, smc_type, ini);
587 	if (rc)
588 		return rc;
589 	/* receive SMC Accept CLC message */
590 	return smc_clc_wait_msg(smc, aclc, sizeof(*aclc), SMC_CLC_ACCEPT,
591 				CLC_WAIT_TIME);
592 }
593 
594 /* setup for RDMA connection of client */
595 static int smc_connect_rdma(struct smc_sock *smc,
596 			    struct smc_clc_msg_accept_confirm *aclc,
597 			    struct smc_init_info *ini)
598 {
599 	struct smc_link *link;
600 	int reason_code = 0;
601 
602 	ini->is_smcd = false;
603 	ini->ib_lcl = &aclc->lcl;
604 	ini->ib_clcqpn = ntoh24(aclc->qpn);
605 	ini->srv_first_contact = aclc->hdr.flag;
606 
607 	mutex_lock(&smc_client_lgr_pending);
608 	reason_code = smc_conn_create(smc, ini);
609 	if (reason_code) {
610 		mutex_unlock(&smc_client_lgr_pending);
611 		return reason_code;
612 	}
613 	link = &smc->conn.lgr->lnk[SMC_SINGLE_LINK];
614 
615 	smc_conn_save_peer_info(smc, aclc);
616 
617 	/* create send buffer and rmb */
618 	if (smc_buf_create(smc, false))
619 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM,
620 					 ini->cln_first_contact);
621 
622 	if (ini->cln_first_contact == SMC_FIRST_CONTACT)
623 		smc_link_save_peer_info(link, aclc);
624 
625 	if (smc_rmb_rtoken_handling(&smc->conn, aclc))
626 		return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RTOK,
627 					 ini->cln_first_contact);
628 
629 	smc_close_init(smc);
630 	smc_rx_init(smc);
631 
632 	if (ini->cln_first_contact == SMC_FIRST_CONTACT) {
633 		if (smc_ib_ready_link(link))
634 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RDYLNK,
635 						 ini->cln_first_contact);
636 	} else {
637 		if (smc_reg_rmb(link, smc->conn.rmb_desc, true))
638 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_REGRMB,
639 						 ini->cln_first_contact);
640 	}
641 	smc_rmb_sync_sg_for_device(&smc->conn);
642 
643 	reason_code = smc_clc_send_confirm(smc);
644 	if (reason_code)
645 		return smc_connect_abort(smc, reason_code,
646 					 ini->cln_first_contact);
647 
648 	smc_tx_init(smc);
649 
650 	if (ini->cln_first_contact == SMC_FIRST_CONTACT) {
651 		/* QP confirmation over RoCE fabric */
652 		reason_code = smc_clnt_conf_first_link(smc);
653 		if (reason_code)
654 			return smc_connect_abort(smc, reason_code,
655 						 ini->cln_first_contact);
656 	}
657 	mutex_unlock(&smc_client_lgr_pending);
658 
659 	smc_copy_sock_settings_to_clc(smc);
660 	smc->connect_nonblock = 0;
661 	if (smc->sk.sk_state == SMC_INIT)
662 		smc->sk.sk_state = SMC_ACTIVE;
663 
664 	return 0;
665 }
666 
667 /* setup for ISM connection of client */
668 static int smc_connect_ism(struct smc_sock *smc,
669 			   struct smc_clc_msg_accept_confirm *aclc,
670 			   struct smc_init_info *ini)
671 {
672 	int rc = 0;
673 
674 	ini->is_smcd = true;
675 	ini->ism_gid = aclc->gid;
676 	ini->srv_first_contact = aclc->hdr.flag;
677 
678 	/* there is only one lgr role for SMC-D; use server lock */
679 	mutex_lock(&smc_server_lgr_pending);
680 	rc = smc_conn_create(smc, ini);
681 	if (rc) {
682 		mutex_unlock(&smc_server_lgr_pending);
683 		return rc;
684 	}
685 
686 	/* Create send and receive buffers */
687 	if (smc_buf_create(smc, true))
688 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM,
689 					 ini->cln_first_contact);
690 
691 	smc_conn_save_peer_info(smc, aclc);
692 	smc_close_init(smc);
693 	smc_rx_init(smc);
694 	smc_tx_init(smc);
695 
696 	rc = smc_clc_send_confirm(smc);
697 	if (rc)
698 		return smc_connect_abort(smc, rc, ini->cln_first_contact);
699 	mutex_unlock(&smc_server_lgr_pending);
700 
701 	smc_copy_sock_settings_to_clc(smc);
702 	smc->connect_nonblock = 0;
703 	if (smc->sk.sk_state == SMC_INIT)
704 		smc->sk.sk_state = SMC_ACTIVE;
705 
706 	return 0;
707 }
708 
709 /* perform steps before actually connecting */
710 static int __smc_connect(struct smc_sock *smc)
711 {
712 	bool ism_supported = false, rdma_supported = false;
713 	struct smc_clc_msg_accept_confirm aclc;
714 	struct smc_init_info ini = {0};
715 	int smc_type;
716 	int rc = 0;
717 
718 	if (smc->use_fallback)
719 		return smc_connect_fallback(smc, smc->fallback_rsn);
720 
721 	/* if peer has not signalled SMC-capability, fall back */
722 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
723 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
724 
725 	/* IPSec connections opt out of SMC-R optimizations */
726 	if (using_ipsec(smc))
727 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC);
728 
729 	/* get vlan id from IP device */
730 	if (smc_vlan_by_tcpsk(smc->clcsock, &ini))
731 		return smc_connect_decline_fallback(smc,
732 						    SMC_CLC_DECL_GETVLANERR);
733 
734 	/* check if there is an ism device available */
735 	if (!smc_find_ism_device(smc, &ini) &&
736 	    !smc_connect_ism_vlan_setup(smc, &ini)) {
737 		/* ISM is supported for this connection */
738 		ism_supported = true;
739 		smc_type = SMC_TYPE_D;
740 	}
741 
742 	/* check if there is a rdma device available */
743 	if (!smc_find_rdma_device(smc, &ini)) {
744 		/* RDMA is supported for this connection */
745 		rdma_supported = true;
746 		if (ism_supported)
747 			smc_type = SMC_TYPE_B; /* both */
748 		else
749 			smc_type = SMC_TYPE_R; /* only RDMA */
750 	}
751 
752 	/* if neither ISM nor RDMA are supported, fallback */
753 	if (!rdma_supported && !ism_supported)
754 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_NOSMCDEV);
755 
756 	/* perform CLC handshake */
757 	rc = smc_connect_clc(smc, smc_type, &aclc, &ini);
758 	if (rc) {
759 		smc_connect_ism_vlan_cleanup(smc, ism_supported, &ini);
760 		return smc_connect_decline_fallback(smc, rc);
761 	}
762 
763 	/* depending on previous steps, connect using rdma or ism */
764 	if (rdma_supported && aclc.hdr.path == SMC_TYPE_R)
765 		rc = smc_connect_rdma(smc, &aclc, &ini);
766 	else if (ism_supported && aclc.hdr.path == SMC_TYPE_D)
767 		rc = smc_connect_ism(smc, &aclc, &ini);
768 	else
769 		rc = SMC_CLC_DECL_MODEUNSUPP;
770 	if (rc) {
771 		smc_connect_ism_vlan_cleanup(smc, ism_supported, &ini);
772 		return smc_connect_decline_fallback(smc, rc);
773 	}
774 
775 	smc_connect_ism_vlan_cleanup(smc, ism_supported, &ini);
776 	return 0;
777 }
778 
779 static void smc_connect_work(struct work_struct *work)
780 {
781 	struct smc_sock *smc = container_of(work, struct smc_sock,
782 					    connect_work);
783 	long timeo = smc->sk.sk_sndtimeo;
784 	int rc = 0;
785 
786 	if (!timeo)
787 		timeo = MAX_SCHEDULE_TIMEOUT;
788 	lock_sock(smc->clcsock->sk);
789 	if (smc->clcsock->sk->sk_err) {
790 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
791 	} else if ((1 << smc->clcsock->sk->sk_state) &
792 					(TCPF_SYN_SENT | TCP_SYN_RECV)) {
793 		rc = sk_stream_wait_connect(smc->clcsock->sk, &timeo);
794 		if ((rc == -EPIPE) &&
795 		    ((1 << smc->clcsock->sk->sk_state) &
796 					(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))
797 			rc = 0;
798 	}
799 	release_sock(smc->clcsock->sk);
800 	lock_sock(&smc->sk);
801 	if (rc != 0 || smc->sk.sk_err) {
802 		smc->sk.sk_state = SMC_CLOSED;
803 		if (rc == -EPIPE || rc == -EAGAIN)
804 			smc->sk.sk_err = EPIPE;
805 		else if (signal_pending(current))
806 			smc->sk.sk_err = -sock_intr_errno(timeo);
807 		sock_put(&smc->sk); /* passive closing */
808 		goto out;
809 	}
810 
811 	rc = __smc_connect(smc);
812 	if (rc < 0)
813 		smc->sk.sk_err = -rc;
814 
815 out:
816 	if (!sock_flag(&smc->sk, SOCK_DEAD)) {
817 		if (smc->sk.sk_err) {
818 			smc->sk.sk_state_change(&smc->sk);
819 		} else { /* allow polling before and after fallback decision */
820 			smc->clcsock->sk->sk_write_space(smc->clcsock->sk);
821 			smc->sk.sk_write_space(&smc->sk);
822 		}
823 	}
824 	release_sock(&smc->sk);
825 }
826 
827 static int smc_connect(struct socket *sock, struct sockaddr *addr,
828 		       int alen, int flags)
829 {
830 	struct sock *sk = sock->sk;
831 	struct smc_sock *smc;
832 	int rc = -EINVAL;
833 
834 	smc = smc_sk(sk);
835 
836 	/* separate smc parameter checking to be safe */
837 	if (alen < sizeof(addr->sa_family))
838 		goto out_err;
839 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
840 		goto out_err;
841 
842 	lock_sock(sk);
843 	switch (sk->sk_state) {
844 	default:
845 		goto out;
846 	case SMC_ACTIVE:
847 		rc = -EISCONN;
848 		goto out;
849 	case SMC_INIT:
850 		rc = 0;
851 		break;
852 	}
853 
854 	smc_copy_sock_settings_to_clc(smc);
855 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
856 	if (smc->connect_nonblock) {
857 		rc = -EALREADY;
858 		goto out;
859 	}
860 	rc = kernel_connect(smc->clcsock, addr, alen, flags);
861 	if (rc && rc != -EINPROGRESS)
862 		goto out;
863 
864 	sock_hold(&smc->sk); /* sock put in passive closing */
865 	if (smc->use_fallback)
866 		goto out;
867 	if (flags & O_NONBLOCK) {
868 		if (schedule_work(&smc->connect_work))
869 			smc->connect_nonblock = 1;
870 		rc = -EINPROGRESS;
871 	} else {
872 		rc = __smc_connect(smc);
873 		if (rc < 0)
874 			goto out;
875 		else
876 			rc = 0; /* success cases including fallback */
877 	}
878 
879 out:
880 	release_sock(sk);
881 out_err:
882 	return rc;
883 }
884 
885 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
886 {
887 	struct socket *new_clcsock = NULL;
888 	struct sock *lsk = &lsmc->sk;
889 	struct sock *new_sk;
890 	int rc = -EINVAL;
891 
892 	release_sock(lsk);
893 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
894 	if (!new_sk) {
895 		rc = -ENOMEM;
896 		lsk->sk_err = ENOMEM;
897 		*new_smc = NULL;
898 		lock_sock(lsk);
899 		goto out;
900 	}
901 	*new_smc = smc_sk(new_sk);
902 
903 	mutex_lock(&lsmc->clcsock_release_lock);
904 	if (lsmc->clcsock)
905 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
906 	mutex_unlock(&lsmc->clcsock_release_lock);
907 	lock_sock(lsk);
908 	if  (rc < 0)
909 		lsk->sk_err = -rc;
910 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
911 		new_sk->sk_prot->unhash(new_sk);
912 		if (new_clcsock)
913 			sock_release(new_clcsock);
914 		new_sk->sk_state = SMC_CLOSED;
915 		sock_set_flag(new_sk, SOCK_DEAD);
916 		sock_put(new_sk); /* final */
917 		*new_smc = NULL;
918 		goto out;
919 	}
920 
921 	(*new_smc)->clcsock = new_clcsock;
922 out:
923 	return rc;
924 }
925 
926 /* add a just created sock to the accept queue of the listen sock as
927  * candidate for a following socket accept call from user space
928  */
929 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
930 {
931 	struct smc_sock *par = smc_sk(parent);
932 
933 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
934 	spin_lock(&par->accept_q_lock);
935 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
936 	spin_unlock(&par->accept_q_lock);
937 	sk_acceptq_added(parent);
938 }
939 
940 /* remove a socket from the accept queue of its parental listening socket */
941 static void smc_accept_unlink(struct sock *sk)
942 {
943 	struct smc_sock *par = smc_sk(sk)->listen_smc;
944 
945 	spin_lock(&par->accept_q_lock);
946 	list_del_init(&smc_sk(sk)->accept_q);
947 	spin_unlock(&par->accept_q_lock);
948 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
949 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
950 }
951 
952 /* remove a sock from the accept queue to bind it to a new socket created
953  * for a socket accept call from user space
954  */
955 struct sock *smc_accept_dequeue(struct sock *parent,
956 				struct socket *new_sock)
957 {
958 	struct smc_sock *isk, *n;
959 	struct sock *new_sk;
960 
961 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
962 		new_sk = (struct sock *)isk;
963 
964 		smc_accept_unlink(new_sk);
965 		if (new_sk->sk_state == SMC_CLOSED) {
966 			new_sk->sk_prot->unhash(new_sk);
967 			if (isk->clcsock) {
968 				sock_release(isk->clcsock);
969 				isk->clcsock = NULL;
970 			}
971 			sock_put(new_sk); /* final */
972 			continue;
973 		}
974 		if (new_sock) {
975 			sock_graft(new_sk, new_sock);
976 			if (isk->use_fallback) {
977 				smc_sk(new_sk)->clcsock->file = new_sock->file;
978 				isk->clcsock->file->private_data = isk->clcsock;
979 			}
980 		}
981 		return new_sk;
982 	}
983 	return NULL;
984 }
985 
986 /* clean up for a created but never accepted sock */
987 void smc_close_non_accepted(struct sock *sk)
988 {
989 	struct smc_sock *smc = smc_sk(sk);
990 
991 	sock_hold(sk); /* sock_put below */
992 	lock_sock(sk);
993 	if (!sk->sk_lingertime)
994 		/* wait for peer closing */
995 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
996 	__smc_release(smc);
997 	release_sock(sk);
998 	sock_put(sk); /* sock_hold above */
999 	sock_put(sk); /* final sock_put */
1000 }
1001 
1002 static int smc_serv_conf_first_link(struct smc_sock *smc)
1003 {
1004 	struct net *net = sock_net(smc->clcsock->sk);
1005 	struct smc_link_group *lgr = smc->conn.lgr;
1006 	struct smc_link *link;
1007 	int rest;
1008 	int rc;
1009 
1010 	link = &lgr->lnk[SMC_SINGLE_LINK];
1011 
1012 	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
1013 		return SMC_CLC_DECL_ERR_REGRMB;
1014 
1015 	/* send CONFIRM LINK request to client over the RoCE fabric */
1016 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
1017 	if (rc < 0)
1018 		return SMC_CLC_DECL_TIMEOUT_CL;
1019 
1020 	/* receive CONFIRM LINK response from client over the RoCE fabric */
1021 	rest = wait_for_completion_interruptible_timeout(
1022 		&link->llc_confirm_resp,
1023 		SMC_LLC_WAIT_FIRST_TIME);
1024 	if (rest <= 0) {
1025 		struct smc_clc_msg_decline dclc;
1026 
1027 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1028 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1029 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
1030 	}
1031 
1032 	if (link->llc_confirm_resp_rc)
1033 		return SMC_CLC_DECL_RMBE_EC;
1034 
1035 	/* send ADD LINK request to client over the RoCE fabric */
1036 	rc = smc_llc_send_add_link(link,
1037 				   link->smcibdev->mac[link->ibport - 1],
1038 				   link->gid, SMC_LLC_REQ);
1039 	if (rc < 0)
1040 		return SMC_CLC_DECL_TIMEOUT_AL;
1041 
1042 	/* receive ADD LINK response from client over the RoCE fabric */
1043 	rest = wait_for_completion_interruptible_timeout(&link->llc_add_resp,
1044 							 SMC_LLC_WAIT_TIME);
1045 	if (rest <= 0) {
1046 		struct smc_clc_msg_decline dclc;
1047 
1048 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1049 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1050 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_AL : rc;
1051 	}
1052 
1053 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
1054 
1055 	return 0;
1056 }
1057 
1058 /* listen worker: finish */
1059 static void smc_listen_out(struct smc_sock *new_smc)
1060 {
1061 	struct smc_sock *lsmc = new_smc->listen_smc;
1062 	struct sock *newsmcsk = &new_smc->sk;
1063 
1064 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1065 		lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1066 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1067 		release_sock(&lsmc->sk);
1068 	} else { /* no longer listening */
1069 		smc_close_non_accepted(newsmcsk);
1070 	}
1071 
1072 	/* Wake up accept */
1073 	lsmc->sk.sk_data_ready(&lsmc->sk);
1074 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1075 }
1076 
1077 /* listen worker: finish in state connected */
1078 static void smc_listen_out_connected(struct smc_sock *new_smc)
1079 {
1080 	struct sock *newsmcsk = &new_smc->sk;
1081 
1082 	sk_refcnt_debug_inc(newsmcsk);
1083 	if (newsmcsk->sk_state == SMC_INIT)
1084 		newsmcsk->sk_state = SMC_ACTIVE;
1085 
1086 	smc_listen_out(new_smc);
1087 }
1088 
1089 /* listen worker: finish in error state */
1090 static void smc_listen_out_err(struct smc_sock *new_smc)
1091 {
1092 	struct sock *newsmcsk = &new_smc->sk;
1093 
1094 	if (newsmcsk->sk_state == SMC_INIT)
1095 		sock_put(&new_smc->sk); /* passive closing */
1096 	newsmcsk->sk_state = SMC_CLOSED;
1097 
1098 	smc_listen_out(new_smc);
1099 }
1100 
1101 /* listen worker: decline and fall back if possible */
1102 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1103 			       int local_contact)
1104 {
1105 	/* RDMA setup failed, switch back to TCP */
1106 	if (local_contact == SMC_FIRST_CONTACT)
1107 		smc_lgr_cleanup_early(&new_smc->conn);
1108 	else
1109 		smc_conn_free(&new_smc->conn);
1110 	if (reason_code < 0) { /* error, no fallback possible */
1111 		smc_listen_out_err(new_smc);
1112 		return;
1113 	}
1114 	smc_switch_to_fallback(new_smc);
1115 	new_smc->fallback_rsn = reason_code;
1116 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1117 		if (smc_clc_send_decline(new_smc, reason_code) < 0) {
1118 			smc_listen_out_err(new_smc);
1119 			return;
1120 		}
1121 	}
1122 	smc_listen_out_connected(new_smc);
1123 }
1124 
1125 /* listen worker: check prefixes */
1126 static int smc_listen_prfx_check(struct smc_sock *new_smc,
1127 				 struct smc_clc_msg_proposal *pclc)
1128 {
1129 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1130 	struct socket *newclcsock = new_smc->clcsock;
1131 
1132 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1133 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1134 		return SMC_CLC_DECL_DIFFPREFIX;
1135 
1136 	return 0;
1137 }
1138 
1139 /* listen worker: initialize connection and buffers */
1140 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1141 				struct smc_init_info *ini)
1142 {
1143 	int rc;
1144 
1145 	/* allocate connection / link group */
1146 	rc = smc_conn_create(new_smc, ini);
1147 	if (rc)
1148 		return rc;
1149 
1150 	/* create send buffer and rmb */
1151 	if (smc_buf_create(new_smc, false))
1152 		return SMC_CLC_DECL_MEM;
1153 
1154 	return 0;
1155 }
1156 
1157 /* listen worker: initialize connection and buffers for SMC-D */
1158 static int smc_listen_ism_init(struct smc_sock *new_smc,
1159 			       struct smc_clc_msg_proposal *pclc,
1160 			       struct smc_init_info *ini)
1161 {
1162 	struct smc_clc_msg_smcd *pclc_smcd;
1163 	int rc;
1164 
1165 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
1166 	ini->ism_gid = pclc_smcd->gid;
1167 	rc = smc_conn_create(new_smc, ini);
1168 	if (rc)
1169 		return rc;
1170 
1171 	/* Check if peer can be reached via ISM device */
1172 	if (smc_ism_cantalk(new_smc->conn.lgr->peer_gid,
1173 			    new_smc->conn.lgr->vlan_id,
1174 			    new_smc->conn.lgr->smcd)) {
1175 		if (ini->cln_first_contact == SMC_FIRST_CONTACT)
1176 			smc_lgr_cleanup_early(&new_smc->conn);
1177 		else
1178 			smc_conn_free(&new_smc->conn);
1179 		return SMC_CLC_DECL_SMCDNOTALK;
1180 	}
1181 
1182 	/* Create send and receive buffers */
1183 	if (smc_buf_create(new_smc, true)) {
1184 		if (ini->cln_first_contact == SMC_FIRST_CONTACT)
1185 			smc_lgr_cleanup_early(&new_smc->conn);
1186 		else
1187 			smc_conn_free(&new_smc->conn);
1188 		return SMC_CLC_DECL_MEM;
1189 	}
1190 
1191 	return 0;
1192 }
1193 
1194 /* listen worker: register buffers */
1195 static int smc_listen_rdma_reg(struct smc_sock *new_smc, int local_contact)
1196 {
1197 	struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
1198 
1199 	if (local_contact != SMC_FIRST_CONTACT) {
1200 		if (smc_reg_rmb(link, new_smc->conn.rmb_desc, true))
1201 			return SMC_CLC_DECL_ERR_REGRMB;
1202 	}
1203 	smc_rmb_sync_sg_for_device(&new_smc->conn);
1204 
1205 	return 0;
1206 }
1207 
1208 /* listen worker: finish RDMA setup */
1209 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
1210 				  struct smc_clc_msg_accept_confirm *cclc,
1211 				  int local_contact)
1212 {
1213 	struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
1214 	int reason_code = 0;
1215 
1216 	if (local_contact == SMC_FIRST_CONTACT)
1217 		smc_link_save_peer_info(link, cclc);
1218 
1219 	if (smc_rmb_rtoken_handling(&new_smc->conn, cclc)) {
1220 		reason_code = SMC_CLC_DECL_ERR_RTOK;
1221 		goto decline;
1222 	}
1223 
1224 	if (local_contact == SMC_FIRST_CONTACT) {
1225 		if (smc_ib_ready_link(link)) {
1226 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
1227 			goto decline;
1228 		}
1229 		/* QP confirmation over RoCE fabric */
1230 		reason_code = smc_serv_conf_first_link(new_smc);
1231 		if (reason_code)
1232 			goto decline;
1233 	}
1234 	return 0;
1235 
1236 decline:
1237 	smc_listen_decline(new_smc, reason_code, local_contact);
1238 	return reason_code;
1239 }
1240 
1241 /* setup for RDMA connection of server */
1242 static void smc_listen_work(struct work_struct *work)
1243 {
1244 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
1245 						smc_listen_work);
1246 	struct socket *newclcsock = new_smc->clcsock;
1247 	struct smc_clc_msg_accept_confirm cclc;
1248 	struct smc_clc_msg_proposal *pclc;
1249 	struct smc_init_info ini = {0};
1250 	bool ism_supported = false;
1251 	u8 buf[SMC_CLC_MAX_LEN];
1252 	int rc = 0;
1253 
1254 	if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
1255 		return smc_listen_out_err(new_smc);
1256 
1257 	if (new_smc->use_fallback) {
1258 		smc_listen_out_connected(new_smc);
1259 		return;
1260 	}
1261 
1262 	/* check if peer is smc capable */
1263 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
1264 		smc_switch_to_fallback(new_smc);
1265 		new_smc->fallback_rsn = SMC_CLC_DECL_PEERNOSMC;
1266 		smc_listen_out_connected(new_smc);
1267 		return;
1268 	}
1269 
1270 	/* do inband token exchange -
1271 	 * wait for and receive SMC Proposal CLC message
1272 	 */
1273 	pclc = (struct smc_clc_msg_proposal *)&buf;
1274 	rc = smc_clc_wait_msg(new_smc, pclc, SMC_CLC_MAX_LEN,
1275 			      SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
1276 	if (rc)
1277 		goto out_decl;
1278 
1279 	/* IPSec connections opt out of SMC-R optimizations */
1280 	if (using_ipsec(new_smc)) {
1281 		rc = SMC_CLC_DECL_IPSEC;
1282 		goto out_decl;
1283 	}
1284 
1285 	/* check for matching IP prefix and subnet length */
1286 	rc = smc_listen_prfx_check(new_smc, pclc);
1287 	if (rc)
1288 		goto out_decl;
1289 
1290 	/* get vlan id from IP device */
1291 	if (smc_vlan_by_tcpsk(new_smc->clcsock, &ini)) {
1292 		rc = SMC_CLC_DECL_GETVLANERR;
1293 		goto out_decl;
1294 	}
1295 
1296 	mutex_lock(&smc_server_lgr_pending);
1297 	smc_close_init(new_smc);
1298 	smc_rx_init(new_smc);
1299 	smc_tx_init(new_smc);
1300 
1301 	/* check if ISM is available */
1302 	if (pclc->hdr.path == SMC_TYPE_D || pclc->hdr.path == SMC_TYPE_B) {
1303 		ini.is_smcd = true; /* prepare ISM check */
1304 		rc = smc_find_ism_device(new_smc, &ini);
1305 		if (!rc)
1306 			rc = smc_listen_ism_init(new_smc, pclc, &ini);
1307 		if (!rc)
1308 			ism_supported = true;
1309 		else if (pclc->hdr.path == SMC_TYPE_D)
1310 			goto out_unlock; /* skip RDMA and decline */
1311 	}
1312 
1313 	/* check if RDMA is available */
1314 	if (!ism_supported) { /* SMC_TYPE_R or SMC_TYPE_B */
1315 		/* prepare RDMA check */
1316 		ini.is_smcd = false;
1317 		ini.ism_dev = NULL;
1318 		ini.ib_lcl = &pclc->lcl;
1319 		rc = smc_find_rdma_device(new_smc, &ini);
1320 		if (rc) {
1321 			/* no RDMA device found */
1322 			if (pclc->hdr.path == SMC_TYPE_B)
1323 				/* neither ISM nor RDMA device found */
1324 				rc = SMC_CLC_DECL_NOSMCDEV;
1325 			goto out_unlock;
1326 		}
1327 		rc = smc_listen_rdma_init(new_smc, &ini);
1328 		if (rc)
1329 			goto out_unlock;
1330 		rc = smc_listen_rdma_reg(new_smc, ini.cln_first_contact);
1331 		if (rc)
1332 			goto out_unlock;
1333 	}
1334 
1335 	/* send SMC Accept CLC message */
1336 	rc = smc_clc_send_accept(new_smc, ini.cln_first_contact);
1337 	if (rc)
1338 		goto out_unlock;
1339 
1340 	/* SMC-D does not need this lock any more */
1341 	if (ism_supported)
1342 		mutex_unlock(&smc_server_lgr_pending);
1343 
1344 	/* receive SMC Confirm CLC message */
1345 	rc = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
1346 			      SMC_CLC_CONFIRM, CLC_WAIT_TIME);
1347 	if (rc) {
1348 		if (!ism_supported)
1349 			goto out_unlock;
1350 		goto out_decl;
1351 	}
1352 
1353 	/* finish worker */
1354 	if (!ism_supported) {
1355 		rc = smc_listen_rdma_finish(new_smc, &cclc,
1356 					    ini.cln_first_contact);
1357 		mutex_unlock(&smc_server_lgr_pending);
1358 		if (rc)
1359 			return;
1360 	}
1361 	smc_conn_save_peer_info(new_smc, &cclc);
1362 	smc_listen_out_connected(new_smc);
1363 	return;
1364 
1365 out_unlock:
1366 	mutex_unlock(&smc_server_lgr_pending);
1367 out_decl:
1368 	smc_listen_decline(new_smc, rc, ini.cln_first_contact);
1369 }
1370 
1371 static void smc_tcp_listen_work(struct work_struct *work)
1372 {
1373 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
1374 					     tcp_listen_work);
1375 	struct sock *lsk = &lsmc->sk;
1376 	struct smc_sock *new_smc;
1377 	int rc = 0;
1378 
1379 	lock_sock(lsk);
1380 	while (lsk->sk_state == SMC_LISTEN) {
1381 		rc = smc_clcsock_accept(lsmc, &new_smc);
1382 		if (rc)
1383 			goto out;
1384 		if (!new_smc)
1385 			continue;
1386 
1387 		new_smc->listen_smc = lsmc;
1388 		new_smc->use_fallback = lsmc->use_fallback;
1389 		new_smc->fallback_rsn = lsmc->fallback_rsn;
1390 		sock_hold(lsk); /* sock_put in smc_listen_work */
1391 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
1392 		smc_copy_sock_settings_to_smc(new_smc);
1393 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
1394 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
1395 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
1396 		if (!schedule_work(&new_smc->smc_listen_work))
1397 			sock_put(&new_smc->sk);
1398 	}
1399 
1400 out:
1401 	release_sock(lsk);
1402 	sock_put(&lsmc->sk); /* sock_hold in smc_listen */
1403 }
1404 
1405 static int smc_listen(struct socket *sock, int backlog)
1406 {
1407 	struct sock *sk = sock->sk;
1408 	struct smc_sock *smc;
1409 	int rc;
1410 
1411 	smc = smc_sk(sk);
1412 	lock_sock(sk);
1413 
1414 	rc = -EINVAL;
1415 	if ((sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) ||
1416 	    smc->connect_nonblock)
1417 		goto out;
1418 
1419 	rc = 0;
1420 	if (sk->sk_state == SMC_LISTEN) {
1421 		sk->sk_max_ack_backlog = backlog;
1422 		goto out;
1423 	}
1424 	/* some socket options are handled in core, so we could not apply
1425 	 * them to the clc socket -- copy smc socket options to clc socket
1426 	 */
1427 	smc_copy_sock_settings_to_clc(smc);
1428 	if (!smc->use_fallback)
1429 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1430 
1431 	rc = kernel_listen(smc->clcsock, backlog);
1432 	if (rc)
1433 		goto out;
1434 	sk->sk_max_ack_backlog = backlog;
1435 	sk->sk_ack_backlog = 0;
1436 	sk->sk_state = SMC_LISTEN;
1437 	sock_hold(sk); /* sock_hold in tcp_listen_worker */
1438 	if (!schedule_work(&smc->tcp_listen_work))
1439 		sock_put(sk);
1440 
1441 out:
1442 	release_sock(sk);
1443 	return rc;
1444 }
1445 
1446 static int smc_accept(struct socket *sock, struct socket *new_sock,
1447 		      int flags, bool kern)
1448 {
1449 	struct sock *sk = sock->sk, *nsk;
1450 	DECLARE_WAITQUEUE(wait, current);
1451 	struct smc_sock *lsmc;
1452 	long timeo;
1453 	int rc = 0;
1454 
1455 	lsmc = smc_sk(sk);
1456 	sock_hold(sk); /* sock_put below */
1457 	lock_sock(sk);
1458 
1459 	if (lsmc->sk.sk_state != SMC_LISTEN) {
1460 		rc = -EINVAL;
1461 		release_sock(sk);
1462 		goto out;
1463 	}
1464 
1465 	/* Wait for an incoming connection */
1466 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1467 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
1468 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1469 		set_current_state(TASK_INTERRUPTIBLE);
1470 		if (!timeo) {
1471 			rc = -EAGAIN;
1472 			break;
1473 		}
1474 		release_sock(sk);
1475 		timeo = schedule_timeout(timeo);
1476 		/* wakeup by sk_data_ready in smc_listen_work() */
1477 		sched_annotate_sleep();
1478 		lock_sock(sk);
1479 		if (signal_pending(current)) {
1480 			rc = sock_intr_errno(timeo);
1481 			break;
1482 		}
1483 	}
1484 	set_current_state(TASK_RUNNING);
1485 	remove_wait_queue(sk_sleep(sk), &wait);
1486 
1487 	if (!rc)
1488 		rc = sock_error(nsk);
1489 	release_sock(sk);
1490 	if (rc)
1491 		goto out;
1492 
1493 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
1494 		/* wait till data arrives on the socket */
1495 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
1496 								MSEC_PER_SEC);
1497 		if (smc_sk(nsk)->use_fallback) {
1498 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
1499 
1500 			lock_sock(clcsk);
1501 			if (skb_queue_empty(&clcsk->sk_receive_queue))
1502 				sk_wait_data(clcsk, &timeo, NULL);
1503 			release_sock(clcsk);
1504 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
1505 			lock_sock(nsk);
1506 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
1507 			release_sock(nsk);
1508 		}
1509 	}
1510 
1511 out:
1512 	sock_put(sk); /* sock_hold above */
1513 	return rc;
1514 }
1515 
1516 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1517 		       int peer)
1518 {
1519 	struct smc_sock *smc;
1520 
1521 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
1522 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
1523 		return -ENOTCONN;
1524 
1525 	smc = smc_sk(sock->sk);
1526 
1527 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
1528 }
1529 
1530 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1531 {
1532 	struct sock *sk = sock->sk;
1533 	struct smc_sock *smc;
1534 	int rc = -EPIPE;
1535 
1536 	smc = smc_sk(sk);
1537 	lock_sock(sk);
1538 	if ((sk->sk_state != SMC_ACTIVE) &&
1539 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1540 	    (sk->sk_state != SMC_INIT))
1541 		goto out;
1542 
1543 	if (msg->msg_flags & MSG_FASTOPEN) {
1544 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
1545 			smc_switch_to_fallback(smc);
1546 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1547 		} else {
1548 			rc = -EINVAL;
1549 			goto out;
1550 		}
1551 	}
1552 
1553 	if (smc->use_fallback)
1554 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
1555 	else
1556 		rc = smc_tx_sendmsg(smc, msg, len);
1557 out:
1558 	release_sock(sk);
1559 	return rc;
1560 }
1561 
1562 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1563 		       int flags)
1564 {
1565 	struct sock *sk = sock->sk;
1566 	struct smc_sock *smc;
1567 	int rc = -ENOTCONN;
1568 
1569 	smc = smc_sk(sk);
1570 	lock_sock(sk);
1571 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
1572 		/* socket was connected before, no more data to read */
1573 		rc = 0;
1574 		goto out;
1575 	}
1576 	if ((sk->sk_state == SMC_INIT) ||
1577 	    (sk->sk_state == SMC_LISTEN) ||
1578 	    (sk->sk_state == SMC_CLOSED))
1579 		goto out;
1580 
1581 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1582 		rc = 0;
1583 		goto out;
1584 	}
1585 
1586 	if (smc->use_fallback) {
1587 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
1588 	} else {
1589 		msg->msg_namelen = 0;
1590 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
1591 	}
1592 
1593 out:
1594 	release_sock(sk);
1595 	return rc;
1596 }
1597 
1598 static __poll_t smc_accept_poll(struct sock *parent)
1599 {
1600 	struct smc_sock *isk = smc_sk(parent);
1601 	__poll_t mask = 0;
1602 
1603 	spin_lock(&isk->accept_q_lock);
1604 	if (!list_empty(&isk->accept_q))
1605 		mask = EPOLLIN | EPOLLRDNORM;
1606 	spin_unlock(&isk->accept_q_lock);
1607 
1608 	return mask;
1609 }
1610 
1611 static __poll_t smc_poll(struct file *file, struct socket *sock,
1612 			     poll_table *wait)
1613 {
1614 	struct sock *sk = sock->sk;
1615 	struct smc_sock *smc;
1616 	__poll_t mask = 0;
1617 
1618 	if (!sk)
1619 		return EPOLLNVAL;
1620 
1621 	smc = smc_sk(sock->sk);
1622 	if (smc->use_fallback) {
1623 		/* delegate to CLC child sock */
1624 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
1625 		sk->sk_err = smc->clcsock->sk->sk_err;
1626 	} else {
1627 		if (sk->sk_state != SMC_CLOSED)
1628 			sock_poll_wait(file, sock, wait);
1629 		if (sk->sk_err)
1630 			mask |= EPOLLERR;
1631 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1632 		    (sk->sk_state == SMC_CLOSED))
1633 			mask |= EPOLLHUP;
1634 		if (sk->sk_state == SMC_LISTEN) {
1635 			/* woken up by sk_data_ready in smc_listen_work() */
1636 			mask |= smc_accept_poll(sk);
1637 		} else if (smc->use_fallback) { /* as result of connect_work()*/
1638 			mask |= smc->clcsock->ops->poll(file, smc->clcsock,
1639 							   wait);
1640 			sk->sk_err = smc->clcsock->sk->sk_err;
1641 		} else {
1642 			if ((sk->sk_state != SMC_INIT &&
1643 			     atomic_read(&smc->conn.sndbuf_space)) ||
1644 			    sk->sk_shutdown & SEND_SHUTDOWN) {
1645 				mask |= EPOLLOUT | EPOLLWRNORM;
1646 			} else {
1647 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1648 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1649 			}
1650 			if (atomic_read(&smc->conn.bytes_to_rcv))
1651 				mask |= EPOLLIN | EPOLLRDNORM;
1652 			if (sk->sk_shutdown & RCV_SHUTDOWN)
1653 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
1654 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
1655 				mask |= EPOLLIN;
1656 			if (smc->conn.urg_state == SMC_URG_VALID)
1657 				mask |= EPOLLPRI;
1658 		}
1659 	}
1660 
1661 	return mask;
1662 }
1663 
1664 static int smc_shutdown(struct socket *sock, int how)
1665 {
1666 	struct sock *sk = sock->sk;
1667 	struct smc_sock *smc;
1668 	int rc = -EINVAL;
1669 	int rc1 = 0;
1670 
1671 	smc = smc_sk(sk);
1672 
1673 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
1674 		return rc;
1675 
1676 	lock_sock(sk);
1677 
1678 	rc = -ENOTCONN;
1679 	if ((sk->sk_state != SMC_ACTIVE) &&
1680 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
1681 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
1682 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1683 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
1684 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
1685 		goto out;
1686 	if (smc->use_fallback) {
1687 		rc = kernel_sock_shutdown(smc->clcsock, how);
1688 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
1689 		if (sk->sk_shutdown == SHUTDOWN_MASK)
1690 			sk->sk_state = SMC_CLOSED;
1691 		goto out;
1692 	}
1693 	switch (how) {
1694 	case SHUT_RDWR:		/* shutdown in both directions */
1695 		rc = smc_close_active(smc);
1696 		break;
1697 	case SHUT_WR:
1698 		rc = smc_close_shutdown_write(smc);
1699 		break;
1700 	case SHUT_RD:
1701 		rc = 0;
1702 		/* nothing more to do because peer is not involved */
1703 		break;
1704 	}
1705 	if (smc->clcsock)
1706 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
1707 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
1708 	sk->sk_shutdown |= how + 1;
1709 
1710 out:
1711 	release_sock(sk);
1712 	return rc ? rc : rc1;
1713 }
1714 
1715 static int smc_setsockopt(struct socket *sock, int level, int optname,
1716 			  char __user *optval, unsigned int optlen)
1717 {
1718 	struct sock *sk = sock->sk;
1719 	struct smc_sock *smc;
1720 	int val, rc;
1721 
1722 	smc = smc_sk(sk);
1723 
1724 	/* generic setsockopts reaching us here always apply to the
1725 	 * CLC socket
1726 	 */
1727 	rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
1728 					   optval, optlen);
1729 	if (smc->clcsock->sk->sk_err) {
1730 		sk->sk_err = smc->clcsock->sk->sk_err;
1731 		sk->sk_error_report(sk);
1732 	}
1733 
1734 	if (optlen < sizeof(int))
1735 		return -EINVAL;
1736 	if (get_user(val, (int __user *)optval))
1737 		return -EFAULT;
1738 
1739 	lock_sock(sk);
1740 	if (rc || smc->use_fallback)
1741 		goto out;
1742 	switch (optname) {
1743 	case TCP_ULP:
1744 	case TCP_FASTOPEN:
1745 	case TCP_FASTOPEN_CONNECT:
1746 	case TCP_FASTOPEN_KEY:
1747 	case TCP_FASTOPEN_NO_COOKIE:
1748 		/* option not supported by SMC */
1749 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
1750 			smc_switch_to_fallback(smc);
1751 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1752 		} else {
1753 			rc = -EINVAL;
1754 		}
1755 		break;
1756 	case TCP_NODELAY:
1757 		if (sk->sk_state != SMC_INIT &&
1758 		    sk->sk_state != SMC_LISTEN &&
1759 		    sk->sk_state != SMC_CLOSED) {
1760 			if (val)
1761 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1762 						 0);
1763 		}
1764 		break;
1765 	case TCP_CORK:
1766 		if (sk->sk_state != SMC_INIT &&
1767 		    sk->sk_state != SMC_LISTEN &&
1768 		    sk->sk_state != SMC_CLOSED) {
1769 			if (!val)
1770 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1771 						 0);
1772 		}
1773 		break;
1774 	case TCP_DEFER_ACCEPT:
1775 		smc->sockopt_defer_accept = val;
1776 		break;
1777 	default:
1778 		break;
1779 	}
1780 out:
1781 	release_sock(sk);
1782 
1783 	return rc;
1784 }
1785 
1786 static int smc_getsockopt(struct socket *sock, int level, int optname,
1787 			  char __user *optval, int __user *optlen)
1788 {
1789 	struct smc_sock *smc;
1790 
1791 	smc = smc_sk(sock->sk);
1792 	/* socket options apply to the CLC socket */
1793 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
1794 					     optval, optlen);
1795 }
1796 
1797 static int smc_ioctl(struct socket *sock, unsigned int cmd,
1798 		     unsigned long arg)
1799 {
1800 	union smc_host_cursor cons, urg;
1801 	struct smc_connection *conn;
1802 	struct smc_sock *smc;
1803 	int answ;
1804 
1805 	smc = smc_sk(sock->sk);
1806 	conn = &smc->conn;
1807 	lock_sock(&smc->sk);
1808 	if (smc->use_fallback) {
1809 		if (!smc->clcsock) {
1810 			release_sock(&smc->sk);
1811 			return -EBADF;
1812 		}
1813 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
1814 		release_sock(&smc->sk);
1815 		return answ;
1816 	}
1817 	switch (cmd) {
1818 	case SIOCINQ: /* same as FIONREAD */
1819 		if (smc->sk.sk_state == SMC_LISTEN) {
1820 			release_sock(&smc->sk);
1821 			return -EINVAL;
1822 		}
1823 		if (smc->sk.sk_state == SMC_INIT ||
1824 		    smc->sk.sk_state == SMC_CLOSED)
1825 			answ = 0;
1826 		else
1827 			answ = atomic_read(&smc->conn.bytes_to_rcv);
1828 		break;
1829 	case SIOCOUTQ:
1830 		/* output queue size (not send + not acked) */
1831 		if (smc->sk.sk_state == SMC_LISTEN) {
1832 			release_sock(&smc->sk);
1833 			return -EINVAL;
1834 		}
1835 		if (smc->sk.sk_state == SMC_INIT ||
1836 		    smc->sk.sk_state == SMC_CLOSED)
1837 			answ = 0;
1838 		else
1839 			answ = smc->conn.sndbuf_desc->len -
1840 					atomic_read(&smc->conn.sndbuf_space);
1841 		break;
1842 	case SIOCOUTQNSD:
1843 		/* output queue size (not send only) */
1844 		if (smc->sk.sk_state == SMC_LISTEN) {
1845 			release_sock(&smc->sk);
1846 			return -EINVAL;
1847 		}
1848 		if (smc->sk.sk_state == SMC_INIT ||
1849 		    smc->sk.sk_state == SMC_CLOSED)
1850 			answ = 0;
1851 		else
1852 			answ = smc_tx_prepared_sends(&smc->conn);
1853 		break;
1854 	case SIOCATMARK:
1855 		if (smc->sk.sk_state == SMC_LISTEN) {
1856 			release_sock(&smc->sk);
1857 			return -EINVAL;
1858 		}
1859 		if (smc->sk.sk_state == SMC_INIT ||
1860 		    smc->sk.sk_state == SMC_CLOSED) {
1861 			answ = 0;
1862 		} else {
1863 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
1864 			smc_curs_copy(&urg, &conn->urg_curs, conn);
1865 			answ = smc_curs_diff(conn->rmb_desc->len,
1866 					     &cons, &urg) == 1;
1867 		}
1868 		break;
1869 	default:
1870 		release_sock(&smc->sk);
1871 		return -ENOIOCTLCMD;
1872 	}
1873 	release_sock(&smc->sk);
1874 
1875 	return put_user(answ, (int __user *)arg);
1876 }
1877 
1878 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
1879 			    int offset, size_t size, int flags)
1880 {
1881 	struct sock *sk = sock->sk;
1882 	struct smc_sock *smc;
1883 	int rc = -EPIPE;
1884 
1885 	smc = smc_sk(sk);
1886 	lock_sock(sk);
1887 	if (sk->sk_state != SMC_ACTIVE) {
1888 		release_sock(sk);
1889 		goto out;
1890 	}
1891 	release_sock(sk);
1892 	if (smc->use_fallback)
1893 		rc = kernel_sendpage(smc->clcsock, page, offset,
1894 				     size, flags);
1895 	else
1896 		rc = sock_no_sendpage(sock, page, offset, size, flags);
1897 
1898 out:
1899 	return rc;
1900 }
1901 
1902 /* Map the affected portions of the rmbe into an spd, note the number of bytes
1903  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
1904  * updates till whenever a respective page has been fully processed.
1905  * Note that subsequent recv() calls have to wait till all splice() processing
1906  * completed.
1907  */
1908 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
1909 			       struct pipe_inode_info *pipe, size_t len,
1910 			       unsigned int flags)
1911 {
1912 	struct sock *sk = sock->sk;
1913 	struct smc_sock *smc;
1914 	int rc = -ENOTCONN;
1915 
1916 	smc = smc_sk(sk);
1917 	lock_sock(sk);
1918 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
1919 		/* socket was connected before, no more data to read */
1920 		rc = 0;
1921 		goto out;
1922 	}
1923 	if (sk->sk_state == SMC_INIT ||
1924 	    sk->sk_state == SMC_LISTEN ||
1925 	    sk->sk_state == SMC_CLOSED)
1926 		goto out;
1927 
1928 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1929 		rc = 0;
1930 		goto out;
1931 	}
1932 
1933 	if (smc->use_fallback) {
1934 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
1935 						    pipe, len, flags);
1936 	} else {
1937 		if (*ppos) {
1938 			rc = -ESPIPE;
1939 			goto out;
1940 		}
1941 		if (flags & SPLICE_F_NONBLOCK)
1942 			flags = MSG_DONTWAIT;
1943 		else
1944 			flags = 0;
1945 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
1946 	}
1947 out:
1948 	release_sock(sk);
1949 
1950 	return rc;
1951 }
1952 
1953 /* must look like tcp */
1954 static const struct proto_ops smc_sock_ops = {
1955 	.family		= PF_SMC,
1956 	.owner		= THIS_MODULE,
1957 	.release	= smc_release,
1958 	.bind		= smc_bind,
1959 	.connect	= smc_connect,
1960 	.socketpair	= sock_no_socketpair,
1961 	.accept		= smc_accept,
1962 	.getname	= smc_getname,
1963 	.poll		= smc_poll,
1964 	.ioctl		= smc_ioctl,
1965 	.listen		= smc_listen,
1966 	.shutdown	= smc_shutdown,
1967 	.setsockopt	= smc_setsockopt,
1968 	.getsockopt	= smc_getsockopt,
1969 	.sendmsg	= smc_sendmsg,
1970 	.recvmsg	= smc_recvmsg,
1971 	.mmap		= sock_no_mmap,
1972 	.sendpage	= smc_sendpage,
1973 	.splice_read	= smc_splice_read,
1974 };
1975 
1976 static int smc_create(struct net *net, struct socket *sock, int protocol,
1977 		      int kern)
1978 {
1979 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
1980 	struct smc_sock *smc;
1981 	struct sock *sk;
1982 	int rc;
1983 
1984 	rc = -ESOCKTNOSUPPORT;
1985 	if (sock->type != SOCK_STREAM)
1986 		goto out;
1987 
1988 	rc = -EPROTONOSUPPORT;
1989 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
1990 		goto out;
1991 
1992 	rc = -ENOBUFS;
1993 	sock->ops = &smc_sock_ops;
1994 	sk = smc_sock_alloc(net, sock, protocol);
1995 	if (!sk)
1996 		goto out;
1997 
1998 	/* create internal TCP socket for CLC handshake and fallback */
1999 	smc = smc_sk(sk);
2000 	smc->use_fallback = false; /* assume rdma capability first */
2001 	smc->fallback_rsn = 0;
2002 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
2003 			      &smc->clcsock);
2004 	if (rc) {
2005 		sk_common_release(sk);
2006 		goto out;
2007 	}
2008 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
2009 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
2010 
2011 out:
2012 	return rc;
2013 }
2014 
2015 static const struct net_proto_family smc_sock_family_ops = {
2016 	.family	= PF_SMC,
2017 	.owner	= THIS_MODULE,
2018 	.create	= smc_create,
2019 };
2020 
2021 unsigned int smc_net_id;
2022 
2023 static __net_init int smc_net_init(struct net *net)
2024 {
2025 	return smc_pnet_net_init(net);
2026 }
2027 
2028 static void __net_exit smc_net_exit(struct net *net)
2029 {
2030 	smc_pnet_net_exit(net);
2031 }
2032 
2033 static struct pernet_operations smc_net_ops = {
2034 	.init = smc_net_init,
2035 	.exit = smc_net_exit,
2036 	.id   = &smc_net_id,
2037 	.size = sizeof(struct smc_net),
2038 };
2039 
2040 static int __init smc_init(void)
2041 {
2042 	int rc;
2043 
2044 	rc = register_pernet_subsys(&smc_net_ops);
2045 	if (rc)
2046 		return rc;
2047 
2048 	rc = smc_pnet_init();
2049 	if (rc)
2050 		goto out_pernet_subsys;
2051 
2052 	rc = smc_core_init();
2053 	if (rc) {
2054 		pr_err("%s: smc_core_init fails with %d\n", __func__, rc);
2055 		goto out_pnet;
2056 	}
2057 
2058 	rc = smc_llc_init();
2059 	if (rc) {
2060 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
2061 		goto out_core;
2062 	}
2063 
2064 	rc = smc_cdc_init();
2065 	if (rc) {
2066 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
2067 		goto out_core;
2068 	}
2069 
2070 	rc = proto_register(&smc_proto, 1);
2071 	if (rc) {
2072 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
2073 		goto out_core;
2074 	}
2075 
2076 	rc = proto_register(&smc_proto6, 1);
2077 	if (rc) {
2078 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
2079 		goto out_proto;
2080 	}
2081 
2082 	rc = sock_register(&smc_sock_family_ops);
2083 	if (rc) {
2084 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
2085 		goto out_proto6;
2086 	}
2087 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
2088 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
2089 
2090 	rc = smc_ib_register_client();
2091 	if (rc) {
2092 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
2093 		goto out_sock;
2094 	}
2095 
2096 	static_branch_enable(&tcp_have_smc);
2097 	return 0;
2098 
2099 out_sock:
2100 	sock_unregister(PF_SMC);
2101 out_proto6:
2102 	proto_unregister(&smc_proto6);
2103 out_proto:
2104 	proto_unregister(&smc_proto);
2105 out_core:
2106 	smc_core_exit();
2107 out_pnet:
2108 	smc_pnet_exit();
2109 out_pernet_subsys:
2110 	unregister_pernet_subsys(&smc_net_ops);
2111 
2112 	return rc;
2113 }
2114 
2115 static void __exit smc_exit(void)
2116 {
2117 	static_branch_disable(&tcp_have_smc);
2118 	sock_unregister(PF_SMC);
2119 	smc_core_exit();
2120 	smc_ib_unregister_client();
2121 	proto_unregister(&smc_proto6);
2122 	proto_unregister(&smc_proto);
2123 	smc_pnet_exit();
2124 	unregister_pernet_subsys(&smc_net_ops);
2125 	rcu_barrier();
2126 }
2127 
2128 module_init(smc_init);
2129 module_exit(smc_exit);
2130 
2131 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
2132 MODULE_DESCRIPTION("smc socket address family");
2133 MODULE_LICENSE("GPL");
2134 MODULE_ALIAS_NETPROTO(PF_SMC);
2135