xref: /openbmc/linux/net/smc/af_smc.c (revision 74be2d3b)
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 the new rmb on all links */
341 static int smcr_lgr_reg_rmbs(struct smc_link *link,
342 			     struct smc_buf_desc *rmb_desc)
343 {
344 	struct smc_link_group *lgr = link->lgr;
345 	int i, rc = 0;
346 
347 	rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
348 	if (rc)
349 		return rc;
350 	/* protect against parallel smc_llc_cli_rkey_exchange() and
351 	 * parallel smcr_link_reg_rmb()
352 	 */
353 	mutex_lock(&lgr->llc_conf_mutex);
354 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
355 		if (lgr->lnk[i].state != SMC_LNK_ACTIVE)
356 			continue;
357 		rc = smcr_link_reg_rmb(&lgr->lnk[i], rmb_desc);
358 		if (rc)
359 			goto out;
360 	}
361 
362 	/* exchange confirm_rkey msg with peer */
363 	rc = smc_llc_do_confirm_rkey(link, rmb_desc);
364 	if (rc) {
365 		rc = -EFAULT;
366 		goto out;
367 	}
368 	rmb_desc->is_conf_rkey = true;
369 out:
370 	mutex_unlock(&lgr->llc_conf_mutex);
371 	smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
372 	return rc;
373 }
374 
375 static int smcr_clnt_conf_first_link(struct smc_sock *smc)
376 {
377 	struct smc_link *link = smc->conn.lnk;
378 	struct smc_llc_qentry *qentry;
379 	int rc;
380 
381 	/* receive CONFIRM LINK request from server over RoCE fabric */
382 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
383 			      SMC_LLC_CONFIRM_LINK);
384 	if (!qentry) {
385 		struct smc_clc_msg_decline dclc;
386 
387 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
388 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
389 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
390 	}
391 	smc_llc_save_peer_uid(qentry);
392 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_REQ);
393 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
394 	if (rc)
395 		return SMC_CLC_DECL_RMBE_EC;
396 
397 	rc = smc_ib_modify_qp_rts(link);
398 	if (rc)
399 		return SMC_CLC_DECL_ERR_RDYLNK;
400 
401 	smc_wr_remember_qp_attr(link);
402 
403 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc))
404 		return SMC_CLC_DECL_ERR_REGRMB;
405 
406 	/* confirm_rkey is implicit on 1st contact */
407 	smc->conn.rmb_desc->is_conf_rkey = true;
408 
409 	/* send CONFIRM LINK response over RoCE fabric */
410 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
411 	if (rc < 0)
412 		return SMC_CLC_DECL_TIMEOUT_CL;
413 
414 	smc_llc_link_active(link);
415 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
416 
417 	/* optional 2nd link, receive ADD LINK request from server */
418 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
419 			      SMC_LLC_ADD_LINK);
420 	if (!qentry) {
421 		struct smc_clc_msg_decline dclc;
422 
423 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
424 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
425 		if (rc == -EAGAIN)
426 			rc = 0; /* no DECLINE received, go with one link */
427 		return rc;
428 	}
429 	smc_llc_flow_qentry_clr(&link->lgr->llc_flow_lcl);
430 	smc_llc_cli_add_link(link, qentry);
431 	return 0;
432 }
433 
434 static void smcr_conn_save_peer_info(struct smc_sock *smc,
435 				     struct smc_clc_msg_accept_confirm *clc)
436 {
437 	int bufsize = smc_uncompress_bufsize(clc->rmbe_size);
438 
439 	smc->conn.peer_rmbe_idx = clc->rmbe_idx;
440 	smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
441 	smc->conn.peer_rmbe_size = bufsize;
442 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
443 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
444 }
445 
446 static void smcd_conn_save_peer_info(struct smc_sock *smc,
447 				     struct smc_clc_msg_accept_confirm *clc)
448 {
449 	int bufsize = smc_uncompress_bufsize(clc->dmbe_size);
450 
451 	smc->conn.peer_rmbe_idx = clc->dmbe_idx;
452 	smc->conn.peer_token = clc->token;
453 	/* msg header takes up space in the buffer */
454 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
455 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
456 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
457 }
458 
459 static void smc_conn_save_peer_info(struct smc_sock *smc,
460 				    struct smc_clc_msg_accept_confirm *clc)
461 {
462 	if (smc->conn.lgr->is_smcd)
463 		smcd_conn_save_peer_info(smc, clc);
464 	else
465 		smcr_conn_save_peer_info(smc, clc);
466 }
467 
468 static void smc_link_save_peer_info(struct smc_link *link,
469 				    struct smc_clc_msg_accept_confirm *clc)
470 {
471 	link->peer_qpn = ntoh24(clc->qpn);
472 	memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
473 	memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
474 	link->peer_psn = ntoh24(clc->psn);
475 	link->peer_mtu = clc->qp_mtu;
476 }
477 
478 static void smc_switch_to_fallback(struct smc_sock *smc)
479 {
480 	smc->use_fallback = true;
481 	if (smc->sk.sk_socket && smc->sk.sk_socket->file) {
482 		smc->clcsock->file = smc->sk.sk_socket->file;
483 		smc->clcsock->file->private_data = smc->clcsock;
484 		smc->clcsock->wq.fasync_list =
485 			smc->sk.sk_socket->wq.fasync_list;
486 	}
487 }
488 
489 /* fall back during connect */
490 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
491 {
492 	smc_switch_to_fallback(smc);
493 	smc->fallback_rsn = reason_code;
494 	smc_copy_sock_settings_to_clc(smc);
495 	smc->connect_nonblock = 0;
496 	if (smc->sk.sk_state == SMC_INIT)
497 		smc->sk.sk_state = SMC_ACTIVE;
498 	return 0;
499 }
500 
501 /* decline and fall back during connect */
502 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code)
503 {
504 	int rc;
505 
506 	if (reason_code < 0) { /* error, fallback is not possible */
507 		if (smc->sk.sk_state == SMC_INIT)
508 			sock_put(&smc->sk); /* passive closing */
509 		return reason_code;
510 	}
511 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
512 		rc = smc_clc_send_decline(smc, reason_code);
513 		if (rc < 0) {
514 			if (smc->sk.sk_state == SMC_INIT)
515 				sock_put(&smc->sk); /* passive closing */
516 			return rc;
517 		}
518 	}
519 	return smc_connect_fallback(smc, reason_code);
520 }
521 
522 /* abort connecting */
523 static int smc_connect_abort(struct smc_sock *smc, int reason_code,
524 			     int local_contact)
525 {
526 	bool is_smcd = smc->conn.lgr->is_smcd;
527 
528 	if (local_contact == SMC_FIRST_CONTACT)
529 		smc_lgr_cleanup_early(&smc->conn);
530 	else
531 		smc_conn_free(&smc->conn);
532 	if (is_smcd)
533 		/* there is only one lgr role for SMC-D; use server lock */
534 		mutex_unlock(&smc_server_lgr_pending);
535 	else
536 		mutex_unlock(&smc_client_lgr_pending);
537 
538 	smc->connect_nonblock = 0;
539 	return reason_code;
540 }
541 
542 /* check if there is a rdma device available for this connection. */
543 /* called for connect and listen */
544 static int smc_find_rdma_device(struct smc_sock *smc, struct smc_init_info *ini)
545 {
546 	/* PNET table look up: search active ib_device and port
547 	 * within same PNETID that also contains the ethernet device
548 	 * used for the internal TCP socket
549 	 */
550 	smc_pnet_find_roce_resource(smc->clcsock->sk, ini);
551 	if (!ini->ib_dev)
552 		return SMC_CLC_DECL_NOSMCRDEV;
553 	return 0;
554 }
555 
556 /* check if there is an ISM device available for this connection. */
557 /* called for connect and listen */
558 static int smc_find_ism_device(struct smc_sock *smc, struct smc_init_info *ini)
559 {
560 	/* Find ISM device with same PNETID as connecting interface  */
561 	smc_pnet_find_ism_resource(smc->clcsock->sk, ini);
562 	if (!ini->ism_dev)
563 		return SMC_CLC_DECL_NOSMCDDEV;
564 	return 0;
565 }
566 
567 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
568 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
569 				      struct smc_init_info *ini)
570 {
571 	if (ini->vlan_id && smc_ism_get_vlan(ini->ism_dev, ini->vlan_id))
572 		return SMC_CLC_DECL_ISMVLANERR;
573 	return 0;
574 }
575 
576 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
577  * used, the VLAN ID will be registered again during the connection setup.
578  */
579 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc, bool is_smcd,
580 					struct smc_init_info *ini)
581 {
582 	if (!is_smcd)
583 		return 0;
584 	if (ini->vlan_id && smc_ism_put_vlan(ini->ism_dev, ini->vlan_id))
585 		return SMC_CLC_DECL_CNFERR;
586 	return 0;
587 }
588 
589 /* CLC handshake during connect */
590 static int smc_connect_clc(struct smc_sock *smc, int smc_type,
591 			   struct smc_clc_msg_accept_confirm *aclc,
592 			   struct smc_init_info *ini)
593 {
594 	int rc = 0;
595 
596 	/* do inband token exchange */
597 	rc = smc_clc_send_proposal(smc, smc_type, ini);
598 	if (rc)
599 		return rc;
600 	/* receive SMC Accept CLC message */
601 	return smc_clc_wait_msg(smc, aclc, sizeof(*aclc), SMC_CLC_ACCEPT,
602 				CLC_WAIT_TIME);
603 }
604 
605 /* setup for RDMA connection of client */
606 static int smc_connect_rdma(struct smc_sock *smc,
607 			    struct smc_clc_msg_accept_confirm *aclc,
608 			    struct smc_init_info *ini)
609 {
610 	int i, reason_code = 0;
611 	struct smc_link *link;
612 
613 	ini->is_smcd = false;
614 	ini->ib_lcl = &aclc->lcl;
615 	ini->ib_clcqpn = ntoh24(aclc->qpn);
616 	ini->srv_first_contact = aclc->hdr.flag;
617 
618 	mutex_lock(&smc_client_lgr_pending);
619 	reason_code = smc_conn_create(smc, ini);
620 	if (reason_code) {
621 		mutex_unlock(&smc_client_lgr_pending);
622 		return reason_code;
623 	}
624 
625 	smc_conn_save_peer_info(smc, aclc);
626 
627 	if (ini->cln_first_contact == SMC_FIRST_CONTACT) {
628 		link = smc->conn.lnk;
629 	} else {
630 		/* set link that was assigned by server */
631 		link = NULL;
632 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
633 			struct smc_link *l = &smc->conn.lgr->lnk[i];
634 
635 			if (l->peer_qpn == ntoh24(aclc->qpn)) {
636 				link = l;
637 				break;
638 			}
639 		}
640 		if (!link)
641 			return smc_connect_abort(smc, SMC_CLC_DECL_NOSRVLINK,
642 						 ini->cln_first_contact);
643 		smc->conn.lnk = link;
644 	}
645 
646 	/* create send buffer and rmb */
647 	if (smc_buf_create(smc, false))
648 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM,
649 					 ini->cln_first_contact);
650 
651 	if (ini->cln_first_contact == SMC_FIRST_CONTACT)
652 		smc_link_save_peer_info(link, aclc);
653 
654 	if (smc_rmb_rtoken_handling(&smc->conn, link, aclc))
655 		return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RTOK,
656 					 ini->cln_first_contact);
657 
658 	smc_close_init(smc);
659 	smc_rx_init(smc);
660 
661 	if (ini->cln_first_contact == SMC_FIRST_CONTACT) {
662 		if (smc_ib_ready_link(link))
663 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RDYLNK,
664 						 ini->cln_first_contact);
665 	} else {
666 		if (smcr_lgr_reg_rmbs(link, smc->conn.rmb_desc))
667 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_REGRMB,
668 						 ini->cln_first_contact);
669 	}
670 	smc_rmb_sync_sg_for_device(&smc->conn);
671 
672 	reason_code = smc_clc_send_confirm(smc);
673 	if (reason_code)
674 		return smc_connect_abort(smc, reason_code,
675 					 ini->cln_first_contact);
676 
677 	smc_tx_init(smc);
678 
679 	if (ini->cln_first_contact == SMC_FIRST_CONTACT) {
680 		/* QP confirmation over RoCE fabric */
681 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
682 		reason_code = smcr_clnt_conf_first_link(smc);
683 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
684 		if (reason_code)
685 			return smc_connect_abort(smc, reason_code,
686 						 ini->cln_first_contact);
687 	}
688 	mutex_unlock(&smc_client_lgr_pending);
689 
690 	smc_copy_sock_settings_to_clc(smc);
691 	smc->connect_nonblock = 0;
692 	if (smc->sk.sk_state == SMC_INIT)
693 		smc->sk.sk_state = SMC_ACTIVE;
694 
695 	return 0;
696 }
697 
698 /* setup for ISM connection of client */
699 static int smc_connect_ism(struct smc_sock *smc,
700 			   struct smc_clc_msg_accept_confirm *aclc,
701 			   struct smc_init_info *ini)
702 {
703 	int rc = 0;
704 
705 	ini->is_smcd = true;
706 	ini->ism_gid = aclc->gid;
707 	ini->srv_first_contact = aclc->hdr.flag;
708 
709 	/* there is only one lgr role for SMC-D; use server lock */
710 	mutex_lock(&smc_server_lgr_pending);
711 	rc = smc_conn_create(smc, ini);
712 	if (rc) {
713 		mutex_unlock(&smc_server_lgr_pending);
714 		return rc;
715 	}
716 
717 	/* Create send and receive buffers */
718 	if (smc_buf_create(smc, true))
719 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM,
720 					 ini->cln_first_contact);
721 
722 	smc_conn_save_peer_info(smc, aclc);
723 	smc_close_init(smc);
724 	smc_rx_init(smc);
725 	smc_tx_init(smc);
726 
727 	rc = smc_clc_send_confirm(smc);
728 	if (rc)
729 		return smc_connect_abort(smc, rc, ini->cln_first_contact);
730 	mutex_unlock(&smc_server_lgr_pending);
731 
732 	smc_copy_sock_settings_to_clc(smc);
733 	smc->connect_nonblock = 0;
734 	if (smc->sk.sk_state == SMC_INIT)
735 		smc->sk.sk_state = SMC_ACTIVE;
736 
737 	return 0;
738 }
739 
740 /* perform steps before actually connecting */
741 static int __smc_connect(struct smc_sock *smc)
742 {
743 	bool ism_supported = false, rdma_supported = false;
744 	struct smc_clc_msg_accept_confirm aclc;
745 	struct smc_init_info ini = {0};
746 	int smc_type;
747 	int rc = 0;
748 
749 	if (smc->use_fallback)
750 		return smc_connect_fallback(smc, smc->fallback_rsn);
751 
752 	/* if peer has not signalled SMC-capability, fall back */
753 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
754 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
755 
756 	/* IPSec connections opt out of SMC-R optimizations */
757 	if (using_ipsec(smc))
758 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC);
759 
760 	/* get vlan id from IP device */
761 	if (smc_vlan_by_tcpsk(smc->clcsock, &ini))
762 		return smc_connect_decline_fallback(smc,
763 						    SMC_CLC_DECL_GETVLANERR);
764 
765 	/* check if there is an ism device available */
766 	if (!smc_find_ism_device(smc, &ini) &&
767 	    !smc_connect_ism_vlan_setup(smc, &ini)) {
768 		/* ISM is supported for this connection */
769 		ism_supported = true;
770 		smc_type = SMC_TYPE_D;
771 	}
772 
773 	/* check if there is a rdma device available */
774 	if (!smc_find_rdma_device(smc, &ini)) {
775 		/* RDMA is supported for this connection */
776 		rdma_supported = true;
777 		if (ism_supported)
778 			smc_type = SMC_TYPE_B; /* both */
779 		else
780 			smc_type = SMC_TYPE_R; /* only RDMA */
781 	}
782 
783 	/* if neither ISM nor RDMA are supported, fallback */
784 	if (!rdma_supported && !ism_supported)
785 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_NOSMCDEV);
786 
787 	/* perform CLC handshake */
788 	rc = smc_connect_clc(smc, smc_type, &aclc, &ini);
789 	if (rc) {
790 		smc_connect_ism_vlan_cleanup(smc, ism_supported, &ini);
791 		return smc_connect_decline_fallback(smc, rc);
792 	}
793 
794 	/* depending on previous steps, connect using rdma or ism */
795 	if (rdma_supported && aclc.hdr.path == SMC_TYPE_R)
796 		rc = smc_connect_rdma(smc, &aclc, &ini);
797 	else if (ism_supported && aclc.hdr.path == SMC_TYPE_D)
798 		rc = smc_connect_ism(smc, &aclc, &ini);
799 	else
800 		rc = SMC_CLC_DECL_MODEUNSUPP;
801 	if (rc) {
802 		smc_connect_ism_vlan_cleanup(smc, ism_supported, &ini);
803 		return smc_connect_decline_fallback(smc, rc);
804 	}
805 
806 	smc_connect_ism_vlan_cleanup(smc, ism_supported, &ini);
807 	return 0;
808 }
809 
810 static void smc_connect_work(struct work_struct *work)
811 {
812 	struct smc_sock *smc = container_of(work, struct smc_sock,
813 					    connect_work);
814 	long timeo = smc->sk.sk_sndtimeo;
815 	int rc = 0;
816 
817 	if (!timeo)
818 		timeo = MAX_SCHEDULE_TIMEOUT;
819 	lock_sock(smc->clcsock->sk);
820 	if (smc->clcsock->sk->sk_err) {
821 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
822 	} else if ((1 << smc->clcsock->sk->sk_state) &
823 					(TCPF_SYN_SENT | TCP_SYN_RECV)) {
824 		rc = sk_stream_wait_connect(smc->clcsock->sk, &timeo);
825 		if ((rc == -EPIPE) &&
826 		    ((1 << smc->clcsock->sk->sk_state) &
827 					(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))
828 			rc = 0;
829 	}
830 	release_sock(smc->clcsock->sk);
831 	lock_sock(&smc->sk);
832 	if (rc != 0 || smc->sk.sk_err) {
833 		smc->sk.sk_state = SMC_CLOSED;
834 		if (rc == -EPIPE || rc == -EAGAIN)
835 			smc->sk.sk_err = EPIPE;
836 		else if (signal_pending(current))
837 			smc->sk.sk_err = -sock_intr_errno(timeo);
838 		sock_put(&smc->sk); /* passive closing */
839 		goto out;
840 	}
841 
842 	rc = __smc_connect(smc);
843 	if (rc < 0)
844 		smc->sk.sk_err = -rc;
845 
846 out:
847 	if (!sock_flag(&smc->sk, SOCK_DEAD)) {
848 		if (smc->sk.sk_err) {
849 			smc->sk.sk_state_change(&smc->sk);
850 		} else { /* allow polling before and after fallback decision */
851 			smc->clcsock->sk->sk_write_space(smc->clcsock->sk);
852 			smc->sk.sk_write_space(&smc->sk);
853 		}
854 	}
855 	release_sock(&smc->sk);
856 }
857 
858 static int smc_connect(struct socket *sock, struct sockaddr *addr,
859 		       int alen, int flags)
860 {
861 	struct sock *sk = sock->sk;
862 	struct smc_sock *smc;
863 	int rc = -EINVAL;
864 
865 	smc = smc_sk(sk);
866 
867 	/* separate smc parameter checking to be safe */
868 	if (alen < sizeof(addr->sa_family))
869 		goto out_err;
870 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
871 		goto out_err;
872 
873 	lock_sock(sk);
874 	switch (sk->sk_state) {
875 	default:
876 		goto out;
877 	case SMC_ACTIVE:
878 		rc = -EISCONN;
879 		goto out;
880 	case SMC_INIT:
881 		rc = 0;
882 		break;
883 	}
884 
885 	smc_copy_sock_settings_to_clc(smc);
886 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
887 	if (smc->connect_nonblock) {
888 		rc = -EALREADY;
889 		goto out;
890 	}
891 	rc = kernel_connect(smc->clcsock, addr, alen, flags);
892 	if (rc && rc != -EINPROGRESS)
893 		goto out;
894 
895 	sock_hold(&smc->sk); /* sock put in passive closing */
896 	if (smc->use_fallback)
897 		goto out;
898 	if (flags & O_NONBLOCK) {
899 		if (schedule_work(&smc->connect_work))
900 			smc->connect_nonblock = 1;
901 		rc = -EINPROGRESS;
902 	} else {
903 		rc = __smc_connect(smc);
904 		if (rc < 0)
905 			goto out;
906 		else
907 			rc = 0; /* success cases including fallback */
908 	}
909 
910 out:
911 	release_sock(sk);
912 out_err:
913 	return rc;
914 }
915 
916 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
917 {
918 	struct socket *new_clcsock = NULL;
919 	struct sock *lsk = &lsmc->sk;
920 	struct sock *new_sk;
921 	int rc = -EINVAL;
922 
923 	release_sock(lsk);
924 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
925 	if (!new_sk) {
926 		rc = -ENOMEM;
927 		lsk->sk_err = ENOMEM;
928 		*new_smc = NULL;
929 		lock_sock(lsk);
930 		goto out;
931 	}
932 	*new_smc = smc_sk(new_sk);
933 
934 	mutex_lock(&lsmc->clcsock_release_lock);
935 	if (lsmc->clcsock)
936 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
937 	mutex_unlock(&lsmc->clcsock_release_lock);
938 	lock_sock(lsk);
939 	if  (rc < 0)
940 		lsk->sk_err = -rc;
941 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
942 		new_sk->sk_prot->unhash(new_sk);
943 		if (new_clcsock)
944 			sock_release(new_clcsock);
945 		new_sk->sk_state = SMC_CLOSED;
946 		sock_set_flag(new_sk, SOCK_DEAD);
947 		sock_put(new_sk); /* final */
948 		*new_smc = NULL;
949 		goto out;
950 	}
951 
952 	(*new_smc)->clcsock = new_clcsock;
953 out:
954 	return rc;
955 }
956 
957 /* add a just created sock to the accept queue of the listen sock as
958  * candidate for a following socket accept call from user space
959  */
960 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
961 {
962 	struct smc_sock *par = smc_sk(parent);
963 
964 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
965 	spin_lock(&par->accept_q_lock);
966 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
967 	spin_unlock(&par->accept_q_lock);
968 	sk_acceptq_added(parent);
969 }
970 
971 /* remove a socket from the accept queue of its parental listening socket */
972 static void smc_accept_unlink(struct sock *sk)
973 {
974 	struct smc_sock *par = smc_sk(sk)->listen_smc;
975 
976 	spin_lock(&par->accept_q_lock);
977 	list_del_init(&smc_sk(sk)->accept_q);
978 	spin_unlock(&par->accept_q_lock);
979 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
980 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
981 }
982 
983 /* remove a sock from the accept queue to bind it to a new socket created
984  * for a socket accept call from user space
985  */
986 struct sock *smc_accept_dequeue(struct sock *parent,
987 				struct socket *new_sock)
988 {
989 	struct smc_sock *isk, *n;
990 	struct sock *new_sk;
991 
992 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
993 		new_sk = (struct sock *)isk;
994 
995 		smc_accept_unlink(new_sk);
996 		if (new_sk->sk_state == SMC_CLOSED) {
997 			new_sk->sk_prot->unhash(new_sk);
998 			if (isk->clcsock) {
999 				sock_release(isk->clcsock);
1000 				isk->clcsock = NULL;
1001 			}
1002 			sock_put(new_sk); /* final */
1003 			continue;
1004 		}
1005 		if (new_sock) {
1006 			sock_graft(new_sk, new_sock);
1007 			if (isk->use_fallback) {
1008 				smc_sk(new_sk)->clcsock->file = new_sock->file;
1009 				isk->clcsock->file->private_data = isk->clcsock;
1010 			}
1011 		}
1012 		return new_sk;
1013 	}
1014 	return NULL;
1015 }
1016 
1017 /* clean up for a created but never accepted sock */
1018 void smc_close_non_accepted(struct sock *sk)
1019 {
1020 	struct smc_sock *smc = smc_sk(sk);
1021 
1022 	sock_hold(sk); /* sock_put below */
1023 	lock_sock(sk);
1024 	if (!sk->sk_lingertime)
1025 		/* wait for peer closing */
1026 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
1027 	__smc_release(smc);
1028 	release_sock(sk);
1029 	sock_put(sk); /* sock_hold above */
1030 	sock_put(sk); /* final sock_put */
1031 }
1032 
1033 static int smcr_serv_conf_first_link(struct smc_sock *smc)
1034 {
1035 	struct smc_link *link = smc->conn.lnk;
1036 	struct smc_llc_qentry *qentry;
1037 	int rc;
1038 
1039 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc))
1040 		return SMC_CLC_DECL_ERR_REGRMB;
1041 
1042 	/* send CONFIRM LINK request to client over the RoCE fabric */
1043 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
1044 	if (rc < 0)
1045 		return SMC_CLC_DECL_TIMEOUT_CL;
1046 
1047 	/* receive CONFIRM LINK response from client over the RoCE fabric */
1048 	qentry = smc_llc_wait(link->lgr, link, SMC_LLC_WAIT_TIME,
1049 			      SMC_LLC_CONFIRM_LINK);
1050 	if (!qentry) {
1051 		struct smc_clc_msg_decline dclc;
1052 
1053 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1054 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1055 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
1056 	}
1057 	smc_llc_save_peer_uid(qentry);
1058 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_RESP);
1059 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
1060 	if (rc)
1061 		return SMC_CLC_DECL_RMBE_EC;
1062 
1063 	/* confirm_rkey is implicit on 1st contact */
1064 	smc->conn.rmb_desc->is_conf_rkey = true;
1065 
1066 	smc_llc_link_active(link);
1067 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
1068 
1069 	/* initial contact - try to establish second link */
1070 	smc_llc_srv_add_link(link);
1071 	return 0;
1072 }
1073 
1074 /* listen worker: finish */
1075 static void smc_listen_out(struct smc_sock *new_smc)
1076 {
1077 	struct smc_sock *lsmc = new_smc->listen_smc;
1078 	struct sock *newsmcsk = &new_smc->sk;
1079 
1080 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1081 		lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1082 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1083 		release_sock(&lsmc->sk);
1084 	} else { /* no longer listening */
1085 		smc_close_non_accepted(newsmcsk);
1086 	}
1087 
1088 	/* Wake up accept */
1089 	lsmc->sk.sk_data_ready(&lsmc->sk);
1090 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1091 }
1092 
1093 /* listen worker: finish in state connected */
1094 static void smc_listen_out_connected(struct smc_sock *new_smc)
1095 {
1096 	struct sock *newsmcsk = &new_smc->sk;
1097 
1098 	sk_refcnt_debug_inc(newsmcsk);
1099 	if (newsmcsk->sk_state == SMC_INIT)
1100 		newsmcsk->sk_state = SMC_ACTIVE;
1101 
1102 	smc_listen_out(new_smc);
1103 }
1104 
1105 /* listen worker: finish in error state */
1106 static void smc_listen_out_err(struct smc_sock *new_smc)
1107 {
1108 	struct sock *newsmcsk = &new_smc->sk;
1109 
1110 	if (newsmcsk->sk_state == SMC_INIT)
1111 		sock_put(&new_smc->sk); /* passive closing */
1112 	newsmcsk->sk_state = SMC_CLOSED;
1113 
1114 	smc_listen_out(new_smc);
1115 }
1116 
1117 /* listen worker: decline and fall back if possible */
1118 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1119 			       int local_contact)
1120 {
1121 	/* RDMA setup failed, switch back to TCP */
1122 	if (local_contact == SMC_FIRST_CONTACT)
1123 		smc_lgr_cleanup_early(&new_smc->conn);
1124 	else
1125 		smc_conn_free(&new_smc->conn);
1126 	if (reason_code < 0) { /* error, no fallback possible */
1127 		smc_listen_out_err(new_smc);
1128 		return;
1129 	}
1130 	smc_switch_to_fallback(new_smc);
1131 	new_smc->fallback_rsn = reason_code;
1132 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1133 		if (smc_clc_send_decline(new_smc, reason_code) < 0) {
1134 			smc_listen_out_err(new_smc);
1135 			return;
1136 		}
1137 	}
1138 	smc_listen_out_connected(new_smc);
1139 }
1140 
1141 /* listen worker: check prefixes */
1142 static int smc_listen_prfx_check(struct smc_sock *new_smc,
1143 				 struct smc_clc_msg_proposal *pclc)
1144 {
1145 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1146 	struct socket *newclcsock = new_smc->clcsock;
1147 
1148 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1149 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1150 		return SMC_CLC_DECL_DIFFPREFIX;
1151 
1152 	return 0;
1153 }
1154 
1155 /* listen worker: initialize connection and buffers */
1156 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1157 				struct smc_init_info *ini)
1158 {
1159 	int rc;
1160 
1161 	/* allocate connection / link group */
1162 	rc = smc_conn_create(new_smc, ini);
1163 	if (rc)
1164 		return rc;
1165 
1166 	/* create send buffer and rmb */
1167 	if (smc_buf_create(new_smc, false))
1168 		return SMC_CLC_DECL_MEM;
1169 
1170 	return 0;
1171 }
1172 
1173 /* listen worker: initialize connection and buffers for SMC-D */
1174 static int smc_listen_ism_init(struct smc_sock *new_smc,
1175 			       struct smc_clc_msg_proposal *pclc,
1176 			       struct smc_init_info *ini)
1177 {
1178 	struct smc_clc_msg_smcd *pclc_smcd;
1179 	int rc;
1180 
1181 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
1182 	ini->ism_gid = pclc_smcd->gid;
1183 	rc = smc_conn_create(new_smc, ini);
1184 	if (rc)
1185 		return rc;
1186 
1187 	/* Check if peer can be reached via ISM device */
1188 	if (smc_ism_cantalk(new_smc->conn.lgr->peer_gid,
1189 			    new_smc->conn.lgr->vlan_id,
1190 			    new_smc->conn.lgr->smcd)) {
1191 		if (ini->cln_first_contact == SMC_FIRST_CONTACT)
1192 			smc_lgr_cleanup_early(&new_smc->conn);
1193 		else
1194 			smc_conn_free(&new_smc->conn);
1195 		return SMC_CLC_DECL_SMCDNOTALK;
1196 	}
1197 
1198 	/* Create send and receive buffers */
1199 	if (smc_buf_create(new_smc, true)) {
1200 		if (ini->cln_first_contact == SMC_FIRST_CONTACT)
1201 			smc_lgr_cleanup_early(&new_smc->conn);
1202 		else
1203 			smc_conn_free(&new_smc->conn);
1204 		return SMC_CLC_DECL_MEM;
1205 	}
1206 
1207 	return 0;
1208 }
1209 
1210 /* listen worker: register buffers */
1211 static int smc_listen_rdma_reg(struct smc_sock *new_smc, int local_contact)
1212 {
1213 	struct smc_connection *conn = &new_smc->conn;
1214 
1215 	if (local_contact != SMC_FIRST_CONTACT) {
1216 		if (smcr_lgr_reg_rmbs(conn->lnk, conn->rmb_desc))
1217 			return SMC_CLC_DECL_ERR_REGRMB;
1218 	}
1219 	smc_rmb_sync_sg_for_device(&new_smc->conn);
1220 
1221 	return 0;
1222 }
1223 
1224 /* listen worker: finish RDMA setup */
1225 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
1226 				  struct smc_clc_msg_accept_confirm *cclc,
1227 				  int local_contact)
1228 {
1229 	struct smc_link *link = new_smc->conn.lnk;
1230 	int reason_code = 0;
1231 
1232 	if (local_contact == SMC_FIRST_CONTACT)
1233 		smc_link_save_peer_info(link, cclc);
1234 
1235 	if (smc_rmb_rtoken_handling(&new_smc->conn, link, cclc)) {
1236 		reason_code = SMC_CLC_DECL_ERR_RTOK;
1237 		goto decline;
1238 	}
1239 
1240 	if (local_contact == SMC_FIRST_CONTACT) {
1241 		if (smc_ib_ready_link(link)) {
1242 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
1243 			goto decline;
1244 		}
1245 		/* QP confirmation over RoCE fabric */
1246 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
1247 		reason_code = smcr_serv_conf_first_link(new_smc);
1248 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
1249 		if (reason_code)
1250 			goto decline;
1251 	}
1252 	return 0;
1253 
1254 decline:
1255 	smc_listen_decline(new_smc, reason_code, local_contact);
1256 	return reason_code;
1257 }
1258 
1259 /* setup for RDMA connection of server */
1260 static void smc_listen_work(struct work_struct *work)
1261 {
1262 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
1263 						smc_listen_work);
1264 	struct socket *newclcsock = new_smc->clcsock;
1265 	struct smc_clc_msg_accept_confirm cclc;
1266 	struct smc_clc_msg_proposal *pclc;
1267 	struct smc_init_info ini = {0};
1268 	bool ism_supported = false;
1269 	u8 buf[SMC_CLC_MAX_LEN];
1270 	int rc = 0;
1271 
1272 	if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
1273 		return smc_listen_out_err(new_smc);
1274 
1275 	if (new_smc->use_fallback) {
1276 		smc_listen_out_connected(new_smc);
1277 		return;
1278 	}
1279 
1280 	/* check if peer is smc capable */
1281 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
1282 		smc_switch_to_fallback(new_smc);
1283 		new_smc->fallback_rsn = SMC_CLC_DECL_PEERNOSMC;
1284 		smc_listen_out_connected(new_smc);
1285 		return;
1286 	}
1287 
1288 	/* do inband token exchange -
1289 	 * wait for and receive SMC Proposal CLC message
1290 	 */
1291 	pclc = (struct smc_clc_msg_proposal *)&buf;
1292 	rc = smc_clc_wait_msg(new_smc, pclc, SMC_CLC_MAX_LEN,
1293 			      SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
1294 	if (rc)
1295 		goto out_decl;
1296 
1297 	/* IPSec connections opt out of SMC-R optimizations */
1298 	if (using_ipsec(new_smc)) {
1299 		rc = SMC_CLC_DECL_IPSEC;
1300 		goto out_decl;
1301 	}
1302 
1303 	/* check for matching IP prefix and subnet length */
1304 	rc = smc_listen_prfx_check(new_smc, pclc);
1305 	if (rc)
1306 		goto out_decl;
1307 
1308 	/* get vlan id from IP device */
1309 	if (smc_vlan_by_tcpsk(new_smc->clcsock, &ini)) {
1310 		rc = SMC_CLC_DECL_GETVLANERR;
1311 		goto out_decl;
1312 	}
1313 
1314 	mutex_lock(&smc_server_lgr_pending);
1315 	smc_close_init(new_smc);
1316 	smc_rx_init(new_smc);
1317 	smc_tx_init(new_smc);
1318 
1319 	/* check if ISM is available */
1320 	if (pclc->hdr.path == SMC_TYPE_D || pclc->hdr.path == SMC_TYPE_B) {
1321 		ini.is_smcd = true; /* prepare ISM check */
1322 		rc = smc_find_ism_device(new_smc, &ini);
1323 		if (!rc)
1324 			rc = smc_listen_ism_init(new_smc, pclc, &ini);
1325 		if (!rc)
1326 			ism_supported = true;
1327 		else if (pclc->hdr.path == SMC_TYPE_D)
1328 			goto out_unlock; /* skip RDMA and decline */
1329 	}
1330 
1331 	/* check if RDMA is available */
1332 	if (!ism_supported) { /* SMC_TYPE_R or SMC_TYPE_B */
1333 		/* prepare RDMA check */
1334 		ini.is_smcd = false;
1335 		ini.ism_dev = NULL;
1336 		ini.ib_lcl = &pclc->lcl;
1337 		rc = smc_find_rdma_device(new_smc, &ini);
1338 		if (rc) {
1339 			/* no RDMA device found */
1340 			if (pclc->hdr.path == SMC_TYPE_B)
1341 				/* neither ISM nor RDMA device found */
1342 				rc = SMC_CLC_DECL_NOSMCDEV;
1343 			goto out_unlock;
1344 		}
1345 		rc = smc_listen_rdma_init(new_smc, &ini);
1346 		if (rc)
1347 			goto out_unlock;
1348 		rc = smc_listen_rdma_reg(new_smc, ini.cln_first_contact);
1349 		if (rc)
1350 			goto out_unlock;
1351 	}
1352 
1353 	/* send SMC Accept CLC message */
1354 	rc = smc_clc_send_accept(new_smc, ini.cln_first_contact);
1355 	if (rc)
1356 		goto out_unlock;
1357 
1358 	/* SMC-D does not need this lock any more */
1359 	if (ism_supported)
1360 		mutex_unlock(&smc_server_lgr_pending);
1361 
1362 	/* receive SMC Confirm CLC message */
1363 	rc = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
1364 			      SMC_CLC_CONFIRM, CLC_WAIT_TIME);
1365 	if (rc) {
1366 		if (!ism_supported)
1367 			goto out_unlock;
1368 		goto out_decl;
1369 	}
1370 
1371 	/* finish worker */
1372 	if (!ism_supported) {
1373 		rc = smc_listen_rdma_finish(new_smc, &cclc,
1374 					    ini.cln_first_contact);
1375 		mutex_unlock(&smc_server_lgr_pending);
1376 		if (rc)
1377 			return;
1378 	}
1379 	smc_conn_save_peer_info(new_smc, &cclc);
1380 	smc_listen_out_connected(new_smc);
1381 	return;
1382 
1383 out_unlock:
1384 	mutex_unlock(&smc_server_lgr_pending);
1385 out_decl:
1386 	smc_listen_decline(new_smc, rc, ini.cln_first_contact);
1387 }
1388 
1389 static void smc_tcp_listen_work(struct work_struct *work)
1390 {
1391 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
1392 					     tcp_listen_work);
1393 	struct sock *lsk = &lsmc->sk;
1394 	struct smc_sock *new_smc;
1395 	int rc = 0;
1396 
1397 	lock_sock(lsk);
1398 	while (lsk->sk_state == SMC_LISTEN) {
1399 		rc = smc_clcsock_accept(lsmc, &new_smc);
1400 		if (rc)
1401 			goto out;
1402 		if (!new_smc)
1403 			continue;
1404 
1405 		new_smc->listen_smc = lsmc;
1406 		new_smc->use_fallback = lsmc->use_fallback;
1407 		new_smc->fallback_rsn = lsmc->fallback_rsn;
1408 		sock_hold(lsk); /* sock_put in smc_listen_work */
1409 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
1410 		smc_copy_sock_settings_to_smc(new_smc);
1411 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
1412 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
1413 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
1414 		if (!schedule_work(&new_smc->smc_listen_work))
1415 			sock_put(&new_smc->sk);
1416 	}
1417 
1418 out:
1419 	release_sock(lsk);
1420 	sock_put(&lsmc->sk); /* sock_hold in smc_listen */
1421 }
1422 
1423 static int smc_listen(struct socket *sock, int backlog)
1424 {
1425 	struct sock *sk = sock->sk;
1426 	struct smc_sock *smc;
1427 	int rc;
1428 
1429 	smc = smc_sk(sk);
1430 	lock_sock(sk);
1431 
1432 	rc = -EINVAL;
1433 	if ((sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) ||
1434 	    smc->connect_nonblock)
1435 		goto out;
1436 
1437 	rc = 0;
1438 	if (sk->sk_state == SMC_LISTEN) {
1439 		sk->sk_max_ack_backlog = backlog;
1440 		goto out;
1441 	}
1442 	/* some socket options are handled in core, so we could not apply
1443 	 * them to the clc socket -- copy smc socket options to clc socket
1444 	 */
1445 	smc_copy_sock_settings_to_clc(smc);
1446 	if (!smc->use_fallback)
1447 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1448 
1449 	rc = kernel_listen(smc->clcsock, backlog);
1450 	if (rc)
1451 		goto out;
1452 	sk->sk_max_ack_backlog = backlog;
1453 	sk->sk_ack_backlog = 0;
1454 	sk->sk_state = SMC_LISTEN;
1455 	sock_hold(sk); /* sock_hold in tcp_listen_worker */
1456 	if (!schedule_work(&smc->tcp_listen_work))
1457 		sock_put(sk);
1458 
1459 out:
1460 	release_sock(sk);
1461 	return rc;
1462 }
1463 
1464 static int smc_accept(struct socket *sock, struct socket *new_sock,
1465 		      int flags, bool kern)
1466 {
1467 	struct sock *sk = sock->sk, *nsk;
1468 	DECLARE_WAITQUEUE(wait, current);
1469 	struct smc_sock *lsmc;
1470 	long timeo;
1471 	int rc = 0;
1472 
1473 	lsmc = smc_sk(sk);
1474 	sock_hold(sk); /* sock_put below */
1475 	lock_sock(sk);
1476 
1477 	if (lsmc->sk.sk_state != SMC_LISTEN) {
1478 		rc = -EINVAL;
1479 		release_sock(sk);
1480 		goto out;
1481 	}
1482 
1483 	/* Wait for an incoming connection */
1484 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1485 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
1486 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1487 		set_current_state(TASK_INTERRUPTIBLE);
1488 		if (!timeo) {
1489 			rc = -EAGAIN;
1490 			break;
1491 		}
1492 		release_sock(sk);
1493 		timeo = schedule_timeout(timeo);
1494 		/* wakeup by sk_data_ready in smc_listen_work() */
1495 		sched_annotate_sleep();
1496 		lock_sock(sk);
1497 		if (signal_pending(current)) {
1498 			rc = sock_intr_errno(timeo);
1499 			break;
1500 		}
1501 	}
1502 	set_current_state(TASK_RUNNING);
1503 	remove_wait_queue(sk_sleep(sk), &wait);
1504 
1505 	if (!rc)
1506 		rc = sock_error(nsk);
1507 	release_sock(sk);
1508 	if (rc)
1509 		goto out;
1510 
1511 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
1512 		/* wait till data arrives on the socket */
1513 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
1514 								MSEC_PER_SEC);
1515 		if (smc_sk(nsk)->use_fallback) {
1516 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
1517 
1518 			lock_sock(clcsk);
1519 			if (skb_queue_empty(&clcsk->sk_receive_queue))
1520 				sk_wait_data(clcsk, &timeo, NULL);
1521 			release_sock(clcsk);
1522 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
1523 			lock_sock(nsk);
1524 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
1525 			release_sock(nsk);
1526 		}
1527 	}
1528 
1529 out:
1530 	sock_put(sk); /* sock_hold above */
1531 	return rc;
1532 }
1533 
1534 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1535 		       int peer)
1536 {
1537 	struct smc_sock *smc;
1538 
1539 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
1540 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
1541 		return -ENOTCONN;
1542 
1543 	smc = smc_sk(sock->sk);
1544 
1545 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
1546 }
1547 
1548 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1549 {
1550 	struct sock *sk = sock->sk;
1551 	struct smc_sock *smc;
1552 	int rc = -EPIPE;
1553 
1554 	smc = smc_sk(sk);
1555 	lock_sock(sk);
1556 	if ((sk->sk_state != SMC_ACTIVE) &&
1557 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1558 	    (sk->sk_state != SMC_INIT))
1559 		goto out;
1560 
1561 	if (msg->msg_flags & MSG_FASTOPEN) {
1562 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
1563 			smc_switch_to_fallback(smc);
1564 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1565 		} else {
1566 			rc = -EINVAL;
1567 			goto out;
1568 		}
1569 	}
1570 
1571 	if (smc->use_fallback)
1572 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
1573 	else
1574 		rc = smc_tx_sendmsg(smc, msg, len);
1575 out:
1576 	release_sock(sk);
1577 	return rc;
1578 }
1579 
1580 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1581 		       int flags)
1582 {
1583 	struct sock *sk = sock->sk;
1584 	struct smc_sock *smc;
1585 	int rc = -ENOTCONN;
1586 
1587 	smc = smc_sk(sk);
1588 	lock_sock(sk);
1589 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
1590 		/* socket was connected before, no more data to read */
1591 		rc = 0;
1592 		goto out;
1593 	}
1594 	if ((sk->sk_state == SMC_INIT) ||
1595 	    (sk->sk_state == SMC_LISTEN) ||
1596 	    (sk->sk_state == SMC_CLOSED))
1597 		goto out;
1598 
1599 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1600 		rc = 0;
1601 		goto out;
1602 	}
1603 
1604 	if (smc->use_fallback) {
1605 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
1606 	} else {
1607 		msg->msg_namelen = 0;
1608 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
1609 	}
1610 
1611 out:
1612 	release_sock(sk);
1613 	return rc;
1614 }
1615 
1616 static __poll_t smc_accept_poll(struct sock *parent)
1617 {
1618 	struct smc_sock *isk = smc_sk(parent);
1619 	__poll_t mask = 0;
1620 
1621 	spin_lock(&isk->accept_q_lock);
1622 	if (!list_empty(&isk->accept_q))
1623 		mask = EPOLLIN | EPOLLRDNORM;
1624 	spin_unlock(&isk->accept_q_lock);
1625 
1626 	return mask;
1627 }
1628 
1629 static __poll_t smc_poll(struct file *file, struct socket *sock,
1630 			     poll_table *wait)
1631 {
1632 	struct sock *sk = sock->sk;
1633 	struct smc_sock *smc;
1634 	__poll_t mask = 0;
1635 
1636 	if (!sk)
1637 		return EPOLLNVAL;
1638 
1639 	smc = smc_sk(sock->sk);
1640 	if (smc->use_fallback) {
1641 		/* delegate to CLC child sock */
1642 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
1643 		sk->sk_err = smc->clcsock->sk->sk_err;
1644 	} else {
1645 		if (sk->sk_state != SMC_CLOSED)
1646 			sock_poll_wait(file, sock, wait);
1647 		if (sk->sk_err)
1648 			mask |= EPOLLERR;
1649 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1650 		    (sk->sk_state == SMC_CLOSED))
1651 			mask |= EPOLLHUP;
1652 		if (sk->sk_state == SMC_LISTEN) {
1653 			/* woken up by sk_data_ready in smc_listen_work() */
1654 			mask |= smc_accept_poll(sk);
1655 		} else if (smc->use_fallback) { /* as result of connect_work()*/
1656 			mask |= smc->clcsock->ops->poll(file, smc->clcsock,
1657 							   wait);
1658 			sk->sk_err = smc->clcsock->sk->sk_err;
1659 		} else {
1660 			if ((sk->sk_state != SMC_INIT &&
1661 			     atomic_read(&smc->conn.sndbuf_space)) ||
1662 			    sk->sk_shutdown & SEND_SHUTDOWN) {
1663 				mask |= EPOLLOUT | EPOLLWRNORM;
1664 			} else {
1665 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1666 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1667 			}
1668 			if (atomic_read(&smc->conn.bytes_to_rcv))
1669 				mask |= EPOLLIN | EPOLLRDNORM;
1670 			if (sk->sk_shutdown & RCV_SHUTDOWN)
1671 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
1672 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
1673 				mask |= EPOLLIN;
1674 			if (smc->conn.urg_state == SMC_URG_VALID)
1675 				mask |= EPOLLPRI;
1676 		}
1677 	}
1678 
1679 	return mask;
1680 }
1681 
1682 static int smc_shutdown(struct socket *sock, int how)
1683 {
1684 	struct sock *sk = sock->sk;
1685 	struct smc_sock *smc;
1686 	int rc = -EINVAL;
1687 	int rc1 = 0;
1688 
1689 	smc = smc_sk(sk);
1690 
1691 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
1692 		return rc;
1693 
1694 	lock_sock(sk);
1695 
1696 	rc = -ENOTCONN;
1697 	if ((sk->sk_state != SMC_ACTIVE) &&
1698 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
1699 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
1700 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1701 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
1702 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
1703 		goto out;
1704 	if (smc->use_fallback) {
1705 		rc = kernel_sock_shutdown(smc->clcsock, how);
1706 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
1707 		if (sk->sk_shutdown == SHUTDOWN_MASK)
1708 			sk->sk_state = SMC_CLOSED;
1709 		goto out;
1710 	}
1711 	switch (how) {
1712 	case SHUT_RDWR:		/* shutdown in both directions */
1713 		rc = smc_close_active(smc);
1714 		break;
1715 	case SHUT_WR:
1716 		rc = smc_close_shutdown_write(smc);
1717 		break;
1718 	case SHUT_RD:
1719 		rc = 0;
1720 		/* nothing more to do because peer is not involved */
1721 		break;
1722 	}
1723 	if (smc->clcsock)
1724 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
1725 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
1726 	sk->sk_shutdown |= how + 1;
1727 
1728 out:
1729 	release_sock(sk);
1730 	return rc ? rc : rc1;
1731 }
1732 
1733 static int smc_setsockopt(struct socket *sock, int level, int optname,
1734 			  char __user *optval, unsigned int optlen)
1735 {
1736 	struct sock *sk = sock->sk;
1737 	struct smc_sock *smc;
1738 	int val, rc;
1739 
1740 	smc = smc_sk(sk);
1741 
1742 	/* generic setsockopts reaching us here always apply to the
1743 	 * CLC socket
1744 	 */
1745 	rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
1746 					   optval, optlen);
1747 	if (smc->clcsock->sk->sk_err) {
1748 		sk->sk_err = smc->clcsock->sk->sk_err;
1749 		sk->sk_error_report(sk);
1750 	}
1751 
1752 	if (optlen < sizeof(int))
1753 		return -EINVAL;
1754 	if (get_user(val, (int __user *)optval))
1755 		return -EFAULT;
1756 
1757 	lock_sock(sk);
1758 	if (rc || smc->use_fallback)
1759 		goto out;
1760 	switch (optname) {
1761 	case TCP_ULP:
1762 	case TCP_FASTOPEN:
1763 	case TCP_FASTOPEN_CONNECT:
1764 	case TCP_FASTOPEN_KEY:
1765 	case TCP_FASTOPEN_NO_COOKIE:
1766 		/* option not supported by SMC */
1767 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
1768 			smc_switch_to_fallback(smc);
1769 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1770 		} else {
1771 			rc = -EINVAL;
1772 		}
1773 		break;
1774 	case TCP_NODELAY:
1775 		if (sk->sk_state != SMC_INIT &&
1776 		    sk->sk_state != SMC_LISTEN &&
1777 		    sk->sk_state != SMC_CLOSED) {
1778 			if (val)
1779 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1780 						 0);
1781 		}
1782 		break;
1783 	case TCP_CORK:
1784 		if (sk->sk_state != SMC_INIT &&
1785 		    sk->sk_state != SMC_LISTEN &&
1786 		    sk->sk_state != SMC_CLOSED) {
1787 			if (!val)
1788 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1789 						 0);
1790 		}
1791 		break;
1792 	case TCP_DEFER_ACCEPT:
1793 		smc->sockopt_defer_accept = val;
1794 		break;
1795 	default:
1796 		break;
1797 	}
1798 out:
1799 	release_sock(sk);
1800 
1801 	return rc;
1802 }
1803 
1804 static int smc_getsockopt(struct socket *sock, int level, int optname,
1805 			  char __user *optval, int __user *optlen)
1806 {
1807 	struct smc_sock *smc;
1808 
1809 	smc = smc_sk(sock->sk);
1810 	/* socket options apply to the CLC socket */
1811 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
1812 					     optval, optlen);
1813 }
1814 
1815 static int smc_ioctl(struct socket *sock, unsigned int cmd,
1816 		     unsigned long arg)
1817 {
1818 	union smc_host_cursor cons, urg;
1819 	struct smc_connection *conn;
1820 	struct smc_sock *smc;
1821 	int answ;
1822 
1823 	smc = smc_sk(sock->sk);
1824 	conn = &smc->conn;
1825 	lock_sock(&smc->sk);
1826 	if (smc->use_fallback) {
1827 		if (!smc->clcsock) {
1828 			release_sock(&smc->sk);
1829 			return -EBADF;
1830 		}
1831 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
1832 		release_sock(&smc->sk);
1833 		return answ;
1834 	}
1835 	switch (cmd) {
1836 	case SIOCINQ: /* same as FIONREAD */
1837 		if (smc->sk.sk_state == SMC_LISTEN) {
1838 			release_sock(&smc->sk);
1839 			return -EINVAL;
1840 		}
1841 		if (smc->sk.sk_state == SMC_INIT ||
1842 		    smc->sk.sk_state == SMC_CLOSED)
1843 			answ = 0;
1844 		else
1845 			answ = atomic_read(&smc->conn.bytes_to_rcv);
1846 		break;
1847 	case SIOCOUTQ:
1848 		/* output queue size (not send + not acked) */
1849 		if (smc->sk.sk_state == SMC_LISTEN) {
1850 			release_sock(&smc->sk);
1851 			return -EINVAL;
1852 		}
1853 		if (smc->sk.sk_state == SMC_INIT ||
1854 		    smc->sk.sk_state == SMC_CLOSED)
1855 			answ = 0;
1856 		else
1857 			answ = smc->conn.sndbuf_desc->len -
1858 					atomic_read(&smc->conn.sndbuf_space);
1859 		break;
1860 	case SIOCOUTQNSD:
1861 		/* output queue size (not send only) */
1862 		if (smc->sk.sk_state == SMC_LISTEN) {
1863 			release_sock(&smc->sk);
1864 			return -EINVAL;
1865 		}
1866 		if (smc->sk.sk_state == SMC_INIT ||
1867 		    smc->sk.sk_state == SMC_CLOSED)
1868 			answ = 0;
1869 		else
1870 			answ = smc_tx_prepared_sends(&smc->conn);
1871 		break;
1872 	case SIOCATMARK:
1873 		if (smc->sk.sk_state == SMC_LISTEN) {
1874 			release_sock(&smc->sk);
1875 			return -EINVAL;
1876 		}
1877 		if (smc->sk.sk_state == SMC_INIT ||
1878 		    smc->sk.sk_state == SMC_CLOSED) {
1879 			answ = 0;
1880 		} else {
1881 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
1882 			smc_curs_copy(&urg, &conn->urg_curs, conn);
1883 			answ = smc_curs_diff(conn->rmb_desc->len,
1884 					     &cons, &urg) == 1;
1885 		}
1886 		break;
1887 	default:
1888 		release_sock(&smc->sk);
1889 		return -ENOIOCTLCMD;
1890 	}
1891 	release_sock(&smc->sk);
1892 
1893 	return put_user(answ, (int __user *)arg);
1894 }
1895 
1896 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
1897 			    int offset, size_t size, int flags)
1898 {
1899 	struct sock *sk = sock->sk;
1900 	struct smc_sock *smc;
1901 	int rc = -EPIPE;
1902 
1903 	smc = smc_sk(sk);
1904 	lock_sock(sk);
1905 	if (sk->sk_state != SMC_ACTIVE) {
1906 		release_sock(sk);
1907 		goto out;
1908 	}
1909 	release_sock(sk);
1910 	if (smc->use_fallback)
1911 		rc = kernel_sendpage(smc->clcsock, page, offset,
1912 				     size, flags);
1913 	else
1914 		rc = sock_no_sendpage(sock, page, offset, size, flags);
1915 
1916 out:
1917 	return rc;
1918 }
1919 
1920 /* Map the affected portions of the rmbe into an spd, note the number of bytes
1921  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
1922  * updates till whenever a respective page has been fully processed.
1923  * Note that subsequent recv() calls have to wait till all splice() processing
1924  * completed.
1925  */
1926 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
1927 			       struct pipe_inode_info *pipe, size_t len,
1928 			       unsigned int flags)
1929 {
1930 	struct sock *sk = sock->sk;
1931 	struct smc_sock *smc;
1932 	int rc = -ENOTCONN;
1933 
1934 	smc = smc_sk(sk);
1935 	lock_sock(sk);
1936 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
1937 		/* socket was connected before, no more data to read */
1938 		rc = 0;
1939 		goto out;
1940 	}
1941 	if (sk->sk_state == SMC_INIT ||
1942 	    sk->sk_state == SMC_LISTEN ||
1943 	    sk->sk_state == SMC_CLOSED)
1944 		goto out;
1945 
1946 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1947 		rc = 0;
1948 		goto out;
1949 	}
1950 
1951 	if (smc->use_fallback) {
1952 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
1953 						    pipe, len, flags);
1954 	} else {
1955 		if (*ppos) {
1956 			rc = -ESPIPE;
1957 			goto out;
1958 		}
1959 		if (flags & SPLICE_F_NONBLOCK)
1960 			flags = MSG_DONTWAIT;
1961 		else
1962 			flags = 0;
1963 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
1964 	}
1965 out:
1966 	release_sock(sk);
1967 
1968 	return rc;
1969 }
1970 
1971 /* must look like tcp */
1972 static const struct proto_ops smc_sock_ops = {
1973 	.family		= PF_SMC,
1974 	.owner		= THIS_MODULE,
1975 	.release	= smc_release,
1976 	.bind		= smc_bind,
1977 	.connect	= smc_connect,
1978 	.socketpair	= sock_no_socketpair,
1979 	.accept		= smc_accept,
1980 	.getname	= smc_getname,
1981 	.poll		= smc_poll,
1982 	.ioctl		= smc_ioctl,
1983 	.listen		= smc_listen,
1984 	.shutdown	= smc_shutdown,
1985 	.setsockopt	= smc_setsockopt,
1986 	.getsockopt	= smc_getsockopt,
1987 	.sendmsg	= smc_sendmsg,
1988 	.recvmsg	= smc_recvmsg,
1989 	.mmap		= sock_no_mmap,
1990 	.sendpage	= smc_sendpage,
1991 	.splice_read	= smc_splice_read,
1992 };
1993 
1994 static int smc_create(struct net *net, struct socket *sock, int protocol,
1995 		      int kern)
1996 {
1997 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
1998 	struct smc_sock *smc;
1999 	struct sock *sk;
2000 	int rc;
2001 
2002 	rc = -ESOCKTNOSUPPORT;
2003 	if (sock->type != SOCK_STREAM)
2004 		goto out;
2005 
2006 	rc = -EPROTONOSUPPORT;
2007 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
2008 		goto out;
2009 
2010 	rc = -ENOBUFS;
2011 	sock->ops = &smc_sock_ops;
2012 	sk = smc_sock_alloc(net, sock, protocol);
2013 	if (!sk)
2014 		goto out;
2015 
2016 	/* create internal TCP socket for CLC handshake and fallback */
2017 	smc = smc_sk(sk);
2018 	smc->use_fallback = false; /* assume rdma capability first */
2019 	smc->fallback_rsn = 0;
2020 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
2021 			      &smc->clcsock);
2022 	if (rc) {
2023 		sk_common_release(sk);
2024 		goto out;
2025 	}
2026 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
2027 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
2028 
2029 out:
2030 	return rc;
2031 }
2032 
2033 static const struct net_proto_family smc_sock_family_ops = {
2034 	.family	= PF_SMC,
2035 	.owner	= THIS_MODULE,
2036 	.create	= smc_create,
2037 };
2038 
2039 unsigned int smc_net_id;
2040 
2041 static __net_init int smc_net_init(struct net *net)
2042 {
2043 	return smc_pnet_net_init(net);
2044 }
2045 
2046 static void __net_exit smc_net_exit(struct net *net)
2047 {
2048 	smc_pnet_net_exit(net);
2049 }
2050 
2051 static struct pernet_operations smc_net_ops = {
2052 	.init = smc_net_init,
2053 	.exit = smc_net_exit,
2054 	.id   = &smc_net_id,
2055 	.size = sizeof(struct smc_net),
2056 };
2057 
2058 static int __init smc_init(void)
2059 {
2060 	int rc;
2061 
2062 	rc = register_pernet_subsys(&smc_net_ops);
2063 	if (rc)
2064 		return rc;
2065 
2066 	rc = smc_pnet_init();
2067 	if (rc)
2068 		goto out_pernet_subsys;
2069 
2070 	rc = smc_core_init();
2071 	if (rc) {
2072 		pr_err("%s: smc_core_init fails with %d\n", __func__, rc);
2073 		goto out_pnet;
2074 	}
2075 
2076 	rc = smc_llc_init();
2077 	if (rc) {
2078 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
2079 		goto out_core;
2080 	}
2081 
2082 	rc = smc_cdc_init();
2083 	if (rc) {
2084 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
2085 		goto out_core;
2086 	}
2087 
2088 	rc = proto_register(&smc_proto, 1);
2089 	if (rc) {
2090 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
2091 		goto out_core;
2092 	}
2093 
2094 	rc = proto_register(&smc_proto6, 1);
2095 	if (rc) {
2096 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
2097 		goto out_proto;
2098 	}
2099 
2100 	rc = sock_register(&smc_sock_family_ops);
2101 	if (rc) {
2102 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
2103 		goto out_proto6;
2104 	}
2105 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
2106 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
2107 
2108 	rc = smc_ib_register_client();
2109 	if (rc) {
2110 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
2111 		goto out_sock;
2112 	}
2113 
2114 	static_branch_enable(&tcp_have_smc);
2115 	return 0;
2116 
2117 out_sock:
2118 	sock_unregister(PF_SMC);
2119 out_proto6:
2120 	proto_unregister(&smc_proto6);
2121 out_proto:
2122 	proto_unregister(&smc_proto);
2123 out_core:
2124 	smc_core_exit();
2125 out_pnet:
2126 	smc_pnet_exit();
2127 out_pernet_subsys:
2128 	unregister_pernet_subsys(&smc_net_ops);
2129 
2130 	return rc;
2131 }
2132 
2133 static void __exit smc_exit(void)
2134 {
2135 	static_branch_disable(&tcp_have_smc);
2136 	sock_unregister(PF_SMC);
2137 	smc_core_exit();
2138 	smc_ib_unregister_client();
2139 	proto_unregister(&smc_proto6);
2140 	proto_unregister(&smc_proto);
2141 	smc_pnet_exit();
2142 	unregister_pernet_subsys(&smc_net_ops);
2143 	rcu_barrier();
2144 }
2145 
2146 module_init(smc_init);
2147 module_exit(smc_exit);
2148 
2149 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
2150 MODULE_DESCRIPTION("smc socket address family");
2151 MODULE_LICENSE("GPL");
2152 MODULE_ALIAS_NETPROTO(PF_SMC);
2153