xref: /linux/net/smc/af_smc.c (revision 40e79150c1686263e6a031d7702aec63aff31332)
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 smcr_link_reg_rmb(struct smc_link *link,
342 			     struct smc_buf_desc *rmb_desc, bool conf_rkey)
343 {
344 	if (!rmb_desc->is_reg_mr[link->link_idx]) {
345 		/* register memory region for new rmb */
346 		if (smc_wr_reg_send(link, rmb_desc->mr_rx[link->link_idx])) {
347 			rmb_desc->is_reg_err = true;
348 			return -EFAULT;
349 		}
350 		rmb_desc->is_reg_mr[link->link_idx] = true;
351 	}
352 	if (!conf_rkey)
353 		return 0;
354 
355 	/* exchange confirm_rkey msg with peer */
356 	if (!rmb_desc->is_conf_rkey) {
357 		if (smc_llc_do_confirm_rkey(link, rmb_desc)) {
358 			rmb_desc->is_reg_err = true;
359 			return -EFAULT;
360 		}
361 		rmb_desc->is_conf_rkey = true;
362 	}
363 	return 0;
364 }
365 
366 /* register the new rmb on all links */
367 static int smcr_lgr_reg_rmbs(struct smc_link_group *lgr,
368 			     struct smc_buf_desc *rmb_desc)
369 {
370 	int i, rc;
371 
372 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
373 		if (lgr->lnk[i].state != SMC_LNK_ACTIVE)
374 			continue;
375 		rc = smcr_link_reg_rmb(&lgr->lnk[i], rmb_desc, true);
376 		if (rc)
377 			return rc;
378 	}
379 	return 0;
380 }
381 
382 static int smcr_clnt_conf_first_link(struct smc_sock *smc)
383 {
384 	struct smc_link *link = smc->conn.lnk;
385 	struct smc_llc_qentry *qentry;
386 	int rc;
387 
388 	link->lgr->type = SMC_LGR_SINGLE;
389 
390 	/* receive CONFIRM LINK request from server over RoCE fabric */
391 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
392 			      SMC_LLC_CONFIRM_LINK);
393 	if (!qentry) {
394 		struct smc_clc_msg_decline dclc;
395 
396 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
397 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
398 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
399 	}
400 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_REQ);
401 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
402 	if (rc)
403 		return SMC_CLC_DECL_RMBE_EC;
404 
405 	rc = smc_ib_modify_qp_rts(link);
406 	if (rc)
407 		return SMC_CLC_DECL_ERR_RDYLNK;
408 
409 	smc_wr_remember_qp_attr(link);
410 
411 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc, false))
412 		return SMC_CLC_DECL_ERR_REGRMB;
413 
414 	/* confirm_rkey is implicit on 1st contact */
415 	smc->conn.rmb_desc->is_conf_rkey = true;
416 
417 	/* send CONFIRM LINK response over RoCE fabric */
418 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
419 	if (rc < 0)
420 		return SMC_CLC_DECL_TIMEOUT_CL;
421 
422 	smc_llc_link_active(link);
423 
424 	/* optional 2nd link, receive ADD LINK request from server */
425 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
426 			      SMC_LLC_ADD_LINK);
427 	if (!qentry) {
428 		struct smc_clc_msg_decline dclc;
429 
430 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
431 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
432 		if (rc == -EAGAIN)
433 			rc = 0; /* no DECLINE received, go with one link */
434 		return rc;
435 	}
436 	smc_llc_flow_qentry_clr(&link->lgr->llc_flow_lcl);
437 	/* tbd: call smc_llc_cli_add_link(link, qentry); */
438 	return 0;
439 }
440 
441 static void smcr_conn_save_peer_info(struct smc_sock *smc,
442 				     struct smc_clc_msg_accept_confirm *clc)
443 {
444 	int bufsize = smc_uncompress_bufsize(clc->rmbe_size);
445 
446 	smc->conn.peer_rmbe_idx = clc->rmbe_idx;
447 	smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
448 	smc->conn.peer_rmbe_size = bufsize;
449 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
450 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
451 }
452 
453 static void smcd_conn_save_peer_info(struct smc_sock *smc,
454 				     struct smc_clc_msg_accept_confirm *clc)
455 {
456 	int bufsize = smc_uncompress_bufsize(clc->dmbe_size);
457 
458 	smc->conn.peer_rmbe_idx = clc->dmbe_idx;
459 	smc->conn.peer_token = clc->token;
460 	/* msg header takes up space in the buffer */
461 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
462 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
463 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
464 }
465 
466 static void smc_conn_save_peer_info(struct smc_sock *smc,
467 				    struct smc_clc_msg_accept_confirm *clc)
468 {
469 	if (smc->conn.lgr->is_smcd)
470 		smcd_conn_save_peer_info(smc, clc);
471 	else
472 		smcr_conn_save_peer_info(smc, clc);
473 }
474 
475 static void smc_link_save_peer_info(struct smc_link *link,
476 				    struct smc_clc_msg_accept_confirm *clc)
477 {
478 	link->peer_qpn = ntoh24(clc->qpn);
479 	memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
480 	memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
481 	link->peer_psn = ntoh24(clc->psn);
482 	link->peer_mtu = clc->qp_mtu;
483 }
484 
485 static void smc_switch_to_fallback(struct smc_sock *smc)
486 {
487 	smc->use_fallback = true;
488 	if (smc->sk.sk_socket && smc->sk.sk_socket->file) {
489 		smc->clcsock->file = smc->sk.sk_socket->file;
490 		smc->clcsock->file->private_data = smc->clcsock;
491 		smc->clcsock->wq.fasync_list =
492 			smc->sk.sk_socket->wq.fasync_list;
493 	}
494 }
495 
496 /* fall back during connect */
497 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
498 {
499 	smc_switch_to_fallback(smc);
500 	smc->fallback_rsn = reason_code;
501 	smc_copy_sock_settings_to_clc(smc);
502 	smc->connect_nonblock = 0;
503 	if (smc->sk.sk_state == SMC_INIT)
504 		smc->sk.sk_state = SMC_ACTIVE;
505 	return 0;
506 }
507 
508 /* decline and fall back during connect */
509 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code)
510 {
511 	int rc;
512 
513 	if (reason_code < 0) { /* error, fallback is not possible */
514 		if (smc->sk.sk_state == SMC_INIT)
515 			sock_put(&smc->sk); /* passive closing */
516 		return reason_code;
517 	}
518 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
519 		rc = smc_clc_send_decline(smc, reason_code);
520 		if (rc < 0) {
521 			if (smc->sk.sk_state == SMC_INIT)
522 				sock_put(&smc->sk); /* passive closing */
523 			return rc;
524 		}
525 	}
526 	return smc_connect_fallback(smc, reason_code);
527 }
528 
529 /* abort connecting */
530 static int smc_connect_abort(struct smc_sock *smc, int reason_code,
531 			     int local_contact)
532 {
533 	bool is_smcd = smc->conn.lgr->is_smcd;
534 
535 	if (local_contact == SMC_FIRST_CONTACT)
536 		smc_lgr_cleanup_early(&smc->conn);
537 	else
538 		smc_conn_free(&smc->conn);
539 	if (is_smcd)
540 		/* there is only one lgr role for SMC-D; use server lock */
541 		mutex_unlock(&smc_server_lgr_pending);
542 	else
543 		mutex_unlock(&smc_client_lgr_pending);
544 
545 	smc->connect_nonblock = 0;
546 	return reason_code;
547 }
548 
549 /* check if there is a rdma device available for this connection. */
550 /* called for connect and listen */
551 static int smc_find_rdma_device(struct smc_sock *smc, struct smc_init_info *ini)
552 {
553 	/* PNET table look up: search active ib_device and port
554 	 * within same PNETID that also contains the ethernet device
555 	 * used for the internal TCP socket
556 	 */
557 	smc_pnet_find_roce_resource(smc->clcsock->sk, ini);
558 	if (!ini->ib_dev)
559 		return SMC_CLC_DECL_NOSMCRDEV;
560 	return 0;
561 }
562 
563 /* check if there is an ISM device available for this connection. */
564 /* called for connect and listen */
565 static int smc_find_ism_device(struct smc_sock *smc, struct smc_init_info *ini)
566 {
567 	/* Find ISM device with same PNETID as connecting interface  */
568 	smc_pnet_find_ism_resource(smc->clcsock->sk, ini);
569 	if (!ini->ism_dev)
570 		return SMC_CLC_DECL_NOSMCDDEV;
571 	return 0;
572 }
573 
574 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
575 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
576 				      struct smc_init_info *ini)
577 {
578 	if (ini->vlan_id && smc_ism_get_vlan(ini->ism_dev, ini->vlan_id))
579 		return SMC_CLC_DECL_ISMVLANERR;
580 	return 0;
581 }
582 
583 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
584  * used, the VLAN ID will be registered again during the connection setup.
585  */
586 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc, bool is_smcd,
587 					struct smc_init_info *ini)
588 {
589 	if (!is_smcd)
590 		return 0;
591 	if (ini->vlan_id && smc_ism_put_vlan(ini->ism_dev, ini->vlan_id))
592 		return SMC_CLC_DECL_CNFERR;
593 	return 0;
594 }
595 
596 /* CLC handshake during connect */
597 static int smc_connect_clc(struct smc_sock *smc, int smc_type,
598 			   struct smc_clc_msg_accept_confirm *aclc,
599 			   struct smc_init_info *ini)
600 {
601 	int rc = 0;
602 
603 	/* do inband token exchange */
604 	rc = smc_clc_send_proposal(smc, smc_type, ini);
605 	if (rc)
606 		return rc;
607 	/* receive SMC Accept CLC message */
608 	return smc_clc_wait_msg(smc, aclc, sizeof(*aclc), SMC_CLC_ACCEPT,
609 				CLC_WAIT_TIME);
610 }
611 
612 /* setup for RDMA connection of client */
613 static int smc_connect_rdma(struct smc_sock *smc,
614 			    struct smc_clc_msg_accept_confirm *aclc,
615 			    struct smc_init_info *ini)
616 {
617 	int i, reason_code = 0;
618 	struct smc_link *link;
619 
620 	ini->is_smcd = false;
621 	ini->ib_lcl = &aclc->lcl;
622 	ini->ib_clcqpn = ntoh24(aclc->qpn);
623 	ini->srv_first_contact = aclc->hdr.flag;
624 
625 	mutex_lock(&smc_client_lgr_pending);
626 	reason_code = smc_conn_create(smc, ini);
627 	if (reason_code) {
628 		mutex_unlock(&smc_client_lgr_pending);
629 		return reason_code;
630 	}
631 
632 	smc_conn_save_peer_info(smc, aclc);
633 
634 	if (ini->cln_first_contact == SMC_FIRST_CONTACT) {
635 		link = smc->conn.lnk;
636 	} else {
637 		/* set link that was assigned by server */
638 		link = NULL;
639 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
640 			struct smc_link *l = &smc->conn.lgr->lnk[i];
641 
642 			if (l->peer_qpn == ntoh24(aclc->qpn)) {
643 				link = l;
644 				break;
645 			}
646 		}
647 		if (!link)
648 			return smc_connect_abort(smc, SMC_CLC_DECL_NOSRVLINK,
649 						 ini->cln_first_contact);
650 		smc->conn.lnk = link;
651 	}
652 
653 	/* create send buffer and rmb */
654 	if (smc_buf_create(smc, false))
655 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM,
656 					 ini->cln_first_contact);
657 
658 	if (ini->cln_first_contact == SMC_FIRST_CONTACT)
659 		smc_link_save_peer_info(link, aclc);
660 
661 	if (smc_rmb_rtoken_handling(&smc->conn, link, aclc))
662 		return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RTOK,
663 					 ini->cln_first_contact);
664 
665 	smc_close_init(smc);
666 	smc_rx_init(smc);
667 
668 	if (ini->cln_first_contact == SMC_FIRST_CONTACT) {
669 		if (smc_ib_ready_link(link))
670 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RDYLNK,
671 						 ini->cln_first_contact);
672 	} else {
673 		if (smcr_lgr_reg_rmbs(smc->conn.lgr, smc->conn.rmb_desc))
674 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_REGRMB,
675 						 ini->cln_first_contact);
676 	}
677 	smc_rmb_sync_sg_for_device(&smc->conn);
678 
679 	reason_code = smc_clc_send_confirm(smc);
680 	if (reason_code)
681 		return smc_connect_abort(smc, reason_code,
682 					 ini->cln_first_contact);
683 
684 	smc_tx_init(smc);
685 
686 	if (ini->cln_first_contact == SMC_FIRST_CONTACT) {
687 		/* QP confirmation over RoCE fabric */
688 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
689 		reason_code = smcr_clnt_conf_first_link(smc);
690 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
691 		if (reason_code)
692 			return smc_connect_abort(smc, reason_code,
693 						 ini->cln_first_contact);
694 	}
695 	mutex_unlock(&smc_client_lgr_pending);
696 
697 	smc_copy_sock_settings_to_clc(smc);
698 	smc->connect_nonblock = 0;
699 	if (smc->sk.sk_state == SMC_INIT)
700 		smc->sk.sk_state = SMC_ACTIVE;
701 
702 	return 0;
703 }
704 
705 /* setup for ISM connection of client */
706 static int smc_connect_ism(struct smc_sock *smc,
707 			   struct smc_clc_msg_accept_confirm *aclc,
708 			   struct smc_init_info *ini)
709 {
710 	int rc = 0;
711 
712 	ini->is_smcd = true;
713 	ini->ism_gid = aclc->gid;
714 	ini->srv_first_contact = aclc->hdr.flag;
715 
716 	/* there is only one lgr role for SMC-D; use server lock */
717 	mutex_lock(&smc_server_lgr_pending);
718 	rc = smc_conn_create(smc, ini);
719 	if (rc) {
720 		mutex_unlock(&smc_server_lgr_pending);
721 		return rc;
722 	}
723 
724 	/* Create send and receive buffers */
725 	if (smc_buf_create(smc, true))
726 		return smc_connect_abort(smc, SMC_CLC_DECL_MEM,
727 					 ini->cln_first_contact);
728 
729 	smc_conn_save_peer_info(smc, aclc);
730 	smc_close_init(smc);
731 	smc_rx_init(smc);
732 	smc_tx_init(smc);
733 
734 	rc = smc_clc_send_confirm(smc);
735 	if (rc)
736 		return smc_connect_abort(smc, rc, ini->cln_first_contact);
737 	mutex_unlock(&smc_server_lgr_pending);
738 
739 	smc_copy_sock_settings_to_clc(smc);
740 	smc->connect_nonblock = 0;
741 	if (smc->sk.sk_state == SMC_INIT)
742 		smc->sk.sk_state = SMC_ACTIVE;
743 
744 	return 0;
745 }
746 
747 /* perform steps before actually connecting */
748 static int __smc_connect(struct smc_sock *smc)
749 {
750 	bool ism_supported = false, rdma_supported = false;
751 	struct smc_clc_msg_accept_confirm aclc;
752 	struct smc_init_info ini = {0};
753 	int smc_type;
754 	int rc = 0;
755 
756 	if (smc->use_fallback)
757 		return smc_connect_fallback(smc, smc->fallback_rsn);
758 
759 	/* if peer has not signalled SMC-capability, fall back */
760 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
761 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
762 
763 	/* IPSec connections opt out of SMC-R optimizations */
764 	if (using_ipsec(smc))
765 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC);
766 
767 	/* get vlan id from IP device */
768 	if (smc_vlan_by_tcpsk(smc->clcsock, &ini))
769 		return smc_connect_decline_fallback(smc,
770 						    SMC_CLC_DECL_GETVLANERR);
771 
772 	/* check if there is an ism device available */
773 	if (!smc_find_ism_device(smc, &ini) &&
774 	    !smc_connect_ism_vlan_setup(smc, &ini)) {
775 		/* ISM is supported for this connection */
776 		ism_supported = true;
777 		smc_type = SMC_TYPE_D;
778 	}
779 
780 	/* check if there is a rdma device available */
781 	if (!smc_find_rdma_device(smc, &ini)) {
782 		/* RDMA is supported for this connection */
783 		rdma_supported = true;
784 		if (ism_supported)
785 			smc_type = SMC_TYPE_B; /* both */
786 		else
787 			smc_type = SMC_TYPE_R; /* only RDMA */
788 	}
789 
790 	/* if neither ISM nor RDMA are supported, fallback */
791 	if (!rdma_supported && !ism_supported)
792 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_NOSMCDEV);
793 
794 	/* perform CLC handshake */
795 	rc = smc_connect_clc(smc, smc_type, &aclc, &ini);
796 	if (rc) {
797 		smc_connect_ism_vlan_cleanup(smc, ism_supported, &ini);
798 		return smc_connect_decline_fallback(smc, rc);
799 	}
800 
801 	/* depending on previous steps, connect using rdma or ism */
802 	if (rdma_supported && aclc.hdr.path == SMC_TYPE_R)
803 		rc = smc_connect_rdma(smc, &aclc, &ini);
804 	else if (ism_supported && aclc.hdr.path == SMC_TYPE_D)
805 		rc = smc_connect_ism(smc, &aclc, &ini);
806 	else
807 		rc = SMC_CLC_DECL_MODEUNSUPP;
808 	if (rc) {
809 		smc_connect_ism_vlan_cleanup(smc, ism_supported, &ini);
810 		return smc_connect_decline_fallback(smc, rc);
811 	}
812 
813 	smc_connect_ism_vlan_cleanup(smc, ism_supported, &ini);
814 	return 0;
815 }
816 
817 static void smc_connect_work(struct work_struct *work)
818 {
819 	struct smc_sock *smc = container_of(work, struct smc_sock,
820 					    connect_work);
821 	long timeo = smc->sk.sk_sndtimeo;
822 	int rc = 0;
823 
824 	if (!timeo)
825 		timeo = MAX_SCHEDULE_TIMEOUT;
826 	lock_sock(smc->clcsock->sk);
827 	if (smc->clcsock->sk->sk_err) {
828 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
829 	} else if ((1 << smc->clcsock->sk->sk_state) &
830 					(TCPF_SYN_SENT | TCP_SYN_RECV)) {
831 		rc = sk_stream_wait_connect(smc->clcsock->sk, &timeo);
832 		if ((rc == -EPIPE) &&
833 		    ((1 << smc->clcsock->sk->sk_state) &
834 					(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))
835 			rc = 0;
836 	}
837 	release_sock(smc->clcsock->sk);
838 	lock_sock(&smc->sk);
839 	if (rc != 0 || smc->sk.sk_err) {
840 		smc->sk.sk_state = SMC_CLOSED;
841 		if (rc == -EPIPE || rc == -EAGAIN)
842 			smc->sk.sk_err = EPIPE;
843 		else if (signal_pending(current))
844 			smc->sk.sk_err = -sock_intr_errno(timeo);
845 		sock_put(&smc->sk); /* passive closing */
846 		goto out;
847 	}
848 
849 	rc = __smc_connect(smc);
850 	if (rc < 0)
851 		smc->sk.sk_err = -rc;
852 
853 out:
854 	if (!sock_flag(&smc->sk, SOCK_DEAD)) {
855 		if (smc->sk.sk_err) {
856 			smc->sk.sk_state_change(&smc->sk);
857 		} else { /* allow polling before and after fallback decision */
858 			smc->clcsock->sk->sk_write_space(smc->clcsock->sk);
859 			smc->sk.sk_write_space(&smc->sk);
860 		}
861 	}
862 	release_sock(&smc->sk);
863 }
864 
865 static int smc_connect(struct socket *sock, struct sockaddr *addr,
866 		       int alen, int flags)
867 {
868 	struct sock *sk = sock->sk;
869 	struct smc_sock *smc;
870 	int rc = -EINVAL;
871 
872 	smc = smc_sk(sk);
873 
874 	/* separate smc parameter checking to be safe */
875 	if (alen < sizeof(addr->sa_family))
876 		goto out_err;
877 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
878 		goto out_err;
879 
880 	lock_sock(sk);
881 	switch (sk->sk_state) {
882 	default:
883 		goto out;
884 	case SMC_ACTIVE:
885 		rc = -EISCONN;
886 		goto out;
887 	case SMC_INIT:
888 		rc = 0;
889 		break;
890 	}
891 
892 	smc_copy_sock_settings_to_clc(smc);
893 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
894 	if (smc->connect_nonblock) {
895 		rc = -EALREADY;
896 		goto out;
897 	}
898 	rc = kernel_connect(smc->clcsock, addr, alen, flags);
899 	if (rc && rc != -EINPROGRESS)
900 		goto out;
901 
902 	sock_hold(&smc->sk); /* sock put in passive closing */
903 	if (smc->use_fallback)
904 		goto out;
905 	if (flags & O_NONBLOCK) {
906 		if (schedule_work(&smc->connect_work))
907 			smc->connect_nonblock = 1;
908 		rc = -EINPROGRESS;
909 	} else {
910 		rc = __smc_connect(smc);
911 		if (rc < 0)
912 			goto out;
913 		else
914 			rc = 0; /* success cases including fallback */
915 	}
916 
917 out:
918 	release_sock(sk);
919 out_err:
920 	return rc;
921 }
922 
923 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
924 {
925 	struct socket *new_clcsock = NULL;
926 	struct sock *lsk = &lsmc->sk;
927 	struct sock *new_sk;
928 	int rc = -EINVAL;
929 
930 	release_sock(lsk);
931 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
932 	if (!new_sk) {
933 		rc = -ENOMEM;
934 		lsk->sk_err = ENOMEM;
935 		*new_smc = NULL;
936 		lock_sock(lsk);
937 		goto out;
938 	}
939 	*new_smc = smc_sk(new_sk);
940 
941 	mutex_lock(&lsmc->clcsock_release_lock);
942 	if (lsmc->clcsock)
943 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
944 	mutex_unlock(&lsmc->clcsock_release_lock);
945 	lock_sock(lsk);
946 	if  (rc < 0)
947 		lsk->sk_err = -rc;
948 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
949 		new_sk->sk_prot->unhash(new_sk);
950 		if (new_clcsock)
951 			sock_release(new_clcsock);
952 		new_sk->sk_state = SMC_CLOSED;
953 		sock_set_flag(new_sk, SOCK_DEAD);
954 		sock_put(new_sk); /* final */
955 		*new_smc = NULL;
956 		goto out;
957 	}
958 
959 	(*new_smc)->clcsock = new_clcsock;
960 out:
961 	return rc;
962 }
963 
964 /* add a just created sock to the accept queue of the listen sock as
965  * candidate for a following socket accept call from user space
966  */
967 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
968 {
969 	struct smc_sock *par = smc_sk(parent);
970 
971 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
972 	spin_lock(&par->accept_q_lock);
973 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
974 	spin_unlock(&par->accept_q_lock);
975 	sk_acceptq_added(parent);
976 }
977 
978 /* remove a socket from the accept queue of its parental listening socket */
979 static void smc_accept_unlink(struct sock *sk)
980 {
981 	struct smc_sock *par = smc_sk(sk)->listen_smc;
982 
983 	spin_lock(&par->accept_q_lock);
984 	list_del_init(&smc_sk(sk)->accept_q);
985 	spin_unlock(&par->accept_q_lock);
986 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
987 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
988 }
989 
990 /* remove a sock from the accept queue to bind it to a new socket created
991  * for a socket accept call from user space
992  */
993 struct sock *smc_accept_dequeue(struct sock *parent,
994 				struct socket *new_sock)
995 {
996 	struct smc_sock *isk, *n;
997 	struct sock *new_sk;
998 
999 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
1000 		new_sk = (struct sock *)isk;
1001 
1002 		smc_accept_unlink(new_sk);
1003 		if (new_sk->sk_state == SMC_CLOSED) {
1004 			new_sk->sk_prot->unhash(new_sk);
1005 			if (isk->clcsock) {
1006 				sock_release(isk->clcsock);
1007 				isk->clcsock = NULL;
1008 			}
1009 			sock_put(new_sk); /* final */
1010 			continue;
1011 		}
1012 		if (new_sock) {
1013 			sock_graft(new_sk, new_sock);
1014 			if (isk->use_fallback) {
1015 				smc_sk(new_sk)->clcsock->file = new_sock->file;
1016 				isk->clcsock->file->private_data = isk->clcsock;
1017 			}
1018 		}
1019 		return new_sk;
1020 	}
1021 	return NULL;
1022 }
1023 
1024 /* clean up for a created but never accepted sock */
1025 void smc_close_non_accepted(struct sock *sk)
1026 {
1027 	struct smc_sock *smc = smc_sk(sk);
1028 
1029 	sock_hold(sk); /* sock_put below */
1030 	lock_sock(sk);
1031 	if (!sk->sk_lingertime)
1032 		/* wait for peer closing */
1033 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
1034 	__smc_release(smc);
1035 	release_sock(sk);
1036 	sock_put(sk); /* sock_hold above */
1037 	sock_put(sk); /* final sock_put */
1038 }
1039 
1040 static int smcr_serv_conf_first_link(struct smc_sock *smc)
1041 {
1042 	struct smc_link *link = smc->conn.lnk;
1043 	struct smc_llc_qentry *qentry;
1044 	int rc;
1045 
1046 	link->lgr->type = SMC_LGR_SINGLE;
1047 
1048 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc, false))
1049 		return SMC_CLC_DECL_ERR_REGRMB;
1050 
1051 	/* send CONFIRM LINK request to client over the RoCE fabric */
1052 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
1053 	if (rc < 0)
1054 		return SMC_CLC_DECL_TIMEOUT_CL;
1055 
1056 	/* receive CONFIRM LINK response from client over the RoCE fabric */
1057 	qentry = smc_llc_wait(link->lgr, link, SMC_LLC_WAIT_TIME,
1058 			      SMC_LLC_CONFIRM_LINK);
1059 	if (!qentry) {
1060 		struct smc_clc_msg_decline dclc;
1061 
1062 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1063 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1064 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
1065 	}
1066 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_RESP);
1067 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
1068 	if (rc)
1069 		return SMC_CLC_DECL_RMBE_EC;
1070 
1071 	/* confirm_rkey is implicit on 1st contact */
1072 	smc->conn.rmb_desc->is_conf_rkey = true;
1073 
1074 	smc_llc_link_active(link);
1075 
1076 	/* initial contact - try to establish second link */
1077 	/* tbd: call smc_llc_srv_add_link(link); */
1078 	return 0;
1079 }
1080 
1081 /* listen worker: finish */
1082 static void smc_listen_out(struct smc_sock *new_smc)
1083 {
1084 	struct smc_sock *lsmc = new_smc->listen_smc;
1085 	struct sock *newsmcsk = &new_smc->sk;
1086 
1087 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1088 		lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1089 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1090 		release_sock(&lsmc->sk);
1091 	} else { /* no longer listening */
1092 		smc_close_non_accepted(newsmcsk);
1093 	}
1094 
1095 	/* Wake up accept */
1096 	lsmc->sk.sk_data_ready(&lsmc->sk);
1097 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1098 }
1099 
1100 /* listen worker: finish in state connected */
1101 static void smc_listen_out_connected(struct smc_sock *new_smc)
1102 {
1103 	struct sock *newsmcsk = &new_smc->sk;
1104 
1105 	sk_refcnt_debug_inc(newsmcsk);
1106 	if (newsmcsk->sk_state == SMC_INIT)
1107 		newsmcsk->sk_state = SMC_ACTIVE;
1108 
1109 	smc_listen_out(new_smc);
1110 }
1111 
1112 /* listen worker: finish in error state */
1113 static void smc_listen_out_err(struct smc_sock *new_smc)
1114 {
1115 	struct sock *newsmcsk = &new_smc->sk;
1116 
1117 	if (newsmcsk->sk_state == SMC_INIT)
1118 		sock_put(&new_smc->sk); /* passive closing */
1119 	newsmcsk->sk_state = SMC_CLOSED;
1120 
1121 	smc_listen_out(new_smc);
1122 }
1123 
1124 /* listen worker: decline and fall back if possible */
1125 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1126 			       int local_contact)
1127 {
1128 	/* RDMA setup failed, switch back to TCP */
1129 	if (local_contact == SMC_FIRST_CONTACT)
1130 		smc_lgr_cleanup_early(&new_smc->conn);
1131 	else
1132 		smc_conn_free(&new_smc->conn);
1133 	if (reason_code < 0) { /* error, no fallback possible */
1134 		smc_listen_out_err(new_smc);
1135 		return;
1136 	}
1137 	smc_switch_to_fallback(new_smc);
1138 	new_smc->fallback_rsn = reason_code;
1139 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1140 		if (smc_clc_send_decline(new_smc, reason_code) < 0) {
1141 			smc_listen_out_err(new_smc);
1142 			return;
1143 		}
1144 	}
1145 	smc_listen_out_connected(new_smc);
1146 }
1147 
1148 /* listen worker: check prefixes */
1149 static int smc_listen_prfx_check(struct smc_sock *new_smc,
1150 				 struct smc_clc_msg_proposal *pclc)
1151 {
1152 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1153 	struct socket *newclcsock = new_smc->clcsock;
1154 
1155 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1156 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1157 		return SMC_CLC_DECL_DIFFPREFIX;
1158 
1159 	return 0;
1160 }
1161 
1162 /* listen worker: initialize connection and buffers */
1163 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1164 				struct smc_init_info *ini)
1165 {
1166 	int rc;
1167 
1168 	/* allocate connection / link group */
1169 	rc = smc_conn_create(new_smc, ini);
1170 	if (rc)
1171 		return rc;
1172 
1173 	/* create send buffer and rmb */
1174 	if (smc_buf_create(new_smc, false))
1175 		return SMC_CLC_DECL_MEM;
1176 
1177 	return 0;
1178 }
1179 
1180 /* listen worker: initialize connection and buffers for SMC-D */
1181 static int smc_listen_ism_init(struct smc_sock *new_smc,
1182 			       struct smc_clc_msg_proposal *pclc,
1183 			       struct smc_init_info *ini)
1184 {
1185 	struct smc_clc_msg_smcd *pclc_smcd;
1186 	int rc;
1187 
1188 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
1189 	ini->ism_gid = pclc_smcd->gid;
1190 	rc = smc_conn_create(new_smc, ini);
1191 	if (rc)
1192 		return rc;
1193 
1194 	/* Check if peer can be reached via ISM device */
1195 	if (smc_ism_cantalk(new_smc->conn.lgr->peer_gid,
1196 			    new_smc->conn.lgr->vlan_id,
1197 			    new_smc->conn.lgr->smcd)) {
1198 		if (ini->cln_first_contact == SMC_FIRST_CONTACT)
1199 			smc_lgr_cleanup_early(&new_smc->conn);
1200 		else
1201 			smc_conn_free(&new_smc->conn);
1202 		return SMC_CLC_DECL_SMCDNOTALK;
1203 	}
1204 
1205 	/* Create send and receive buffers */
1206 	if (smc_buf_create(new_smc, true)) {
1207 		if (ini->cln_first_contact == SMC_FIRST_CONTACT)
1208 			smc_lgr_cleanup_early(&new_smc->conn);
1209 		else
1210 			smc_conn_free(&new_smc->conn);
1211 		return SMC_CLC_DECL_MEM;
1212 	}
1213 
1214 	return 0;
1215 }
1216 
1217 /* listen worker: register buffers */
1218 static int smc_listen_rdma_reg(struct smc_sock *new_smc, int local_contact)
1219 {
1220 	struct smc_connection *conn = &new_smc->conn;
1221 
1222 	if (local_contact != SMC_FIRST_CONTACT) {
1223 		if (smcr_lgr_reg_rmbs(conn->lgr, conn->rmb_desc))
1224 			return SMC_CLC_DECL_ERR_REGRMB;
1225 	}
1226 	smc_rmb_sync_sg_for_device(&new_smc->conn);
1227 
1228 	return 0;
1229 }
1230 
1231 /* listen worker: finish RDMA setup */
1232 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
1233 				  struct smc_clc_msg_accept_confirm *cclc,
1234 				  int local_contact)
1235 {
1236 	struct smc_link *link = new_smc->conn.lnk;
1237 	int reason_code = 0;
1238 
1239 	if (local_contact == SMC_FIRST_CONTACT)
1240 		smc_link_save_peer_info(link, cclc);
1241 
1242 	if (smc_rmb_rtoken_handling(&new_smc->conn, link, cclc)) {
1243 		reason_code = SMC_CLC_DECL_ERR_RTOK;
1244 		goto decline;
1245 	}
1246 
1247 	if (local_contact == SMC_FIRST_CONTACT) {
1248 		if (smc_ib_ready_link(link)) {
1249 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
1250 			goto decline;
1251 		}
1252 		/* QP confirmation over RoCE fabric */
1253 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
1254 		reason_code = smcr_serv_conf_first_link(new_smc);
1255 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
1256 		if (reason_code)
1257 			goto decline;
1258 	}
1259 	return 0;
1260 
1261 decline:
1262 	smc_listen_decline(new_smc, reason_code, local_contact);
1263 	return reason_code;
1264 }
1265 
1266 /* setup for RDMA connection of server */
1267 static void smc_listen_work(struct work_struct *work)
1268 {
1269 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
1270 						smc_listen_work);
1271 	struct socket *newclcsock = new_smc->clcsock;
1272 	struct smc_clc_msg_accept_confirm cclc;
1273 	struct smc_clc_msg_proposal *pclc;
1274 	struct smc_init_info ini = {0};
1275 	bool ism_supported = false;
1276 	u8 buf[SMC_CLC_MAX_LEN];
1277 	int rc = 0;
1278 
1279 	if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
1280 		return smc_listen_out_err(new_smc);
1281 
1282 	if (new_smc->use_fallback) {
1283 		smc_listen_out_connected(new_smc);
1284 		return;
1285 	}
1286 
1287 	/* check if peer is smc capable */
1288 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
1289 		smc_switch_to_fallback(new_smc);
1290 		new_smc->fallback_rsn = SMC_CLC_DECL_PEERNOSMC;
1291 		smc_listen_out_connected(new_smc);
1292 		return;
1293 	}
1294 
1295 	/* do inband token exchange -
1296 	 * wait for and receive SMC Proposal CLC message
1297 	 */
1298 	pclc = (struct smc_clc_msg_proposal *)&buf;
1299 	rc = smc_clc_wait_msg(new_smc, pclc, SMC_CLC_MAX_LEN,
1300 			      SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
1301 	if (rc)
1302 		goto out_decl;
1303 
1304 	/* IPSec connections opt out of SMC-R optimizations */
1305 	if (using_ipsec(new_smc)) {
1306 		rc = SMC_CLC_DECL_IPSEC;
1307 		goto out_decl;
1308 	}
1309 
1310 	/* check for matching IP prefix and subnet length */
1311 	rc = smc_listen_prfx_check(new_smc, pclc);
1312 	if (rc)
1313 		goto out_decl;
1314 
1315 	/* get vlan id from IP device */
1316 	if (smc_vlan_by_tcpsk(new_smc->clcsock, &ini)) {
1317 		rc = SMC_CLC_DECL_GETVLANERR;
1318 		goto out_decl;
1319 	}
1320 
1321 	mutex_lock(&smc_server_lgr_pending);
1322 	smc_close_init(new_smc);
1323 	smc_rx_init(new_smc);
1324 	smc_tx_init(new_smc);
1325 
1326 	/* check if ISM is available */
1327 	if (pclc->hdr.path == SMC_TYPE_D || pclc->hdr.path == SMC_TYPE_B) {
1328 		ini.is_smcd = true; /* prepare ISM check */
1329 		rc = smc_find_ism_device(new_smc, &ini);
1330 		if (!rc)
1331 			rc = smc_listen_ism_init(new_smc, pclc, &ini);
1332 		if (!rc)
1333 			ism_supported = true;
1334 		else if (pclc->hdr.path == SMC_TYPE_D)
1335 			goto out_unlock; /* skip RDMA and decline */
1336 	}
1337 
1338 	/* check if RDMA is available */
1339 	if (!ism_supported) { /* SMC_TYPE_R or SMC_TYPE_B */
1340 		/* prepare RDMA check */
1341 		ini.is_smcd = false;
1342 		ini.ism_dev = NULL;
1343 		ini.ib_lcl = &pclc->lcl;
1344 		rc = smc_find_rdma_device(new_smc, &ini);
1345 		if (rc) {
1346 			/* no RDMA device found */
1347 			if (pclc->hdr.path == SMC_TYPE_B)
1348 				/* neither ISM nor RDMA device found */
1349 				rc = SMC_CLC_DECL_NOSMCDEV;
1350 			goto out_unlock;
1351 		}
1352 		rc = smc_listen_rdma_init(new_smc, &ini);
1353 		if (rc)
1354 			goto out_unlock;
1355 		rc = smc_listen_rdma_reg(new_smc, ini.cln_first_contact);
1356 		if (rc)
1357 			goto out_unlock;
1358 	}
1359 
1360 	/* send SMC Accept CLC message */
1361 	rc = smc_clc_send_accept(new_smc, ini.cln_first_contact);
1362 	if (rc)
1363 		goto out_unlock;
1364 
1365 	/* SMC-D does not need this lock any more */
1366 	if (ism_supported)
1367 		mutex_unlock(&smc_server_lgr_pending);
1368 
1369 	/* receive SMC Confirm CLC message */
1370 	rc = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
1371 			      SMC_CLC_CONFIRM, CLC_WAIT_TIME);
1372 	if (rc) {
1373 		if (!ism_supported)
1374 			goto out_unlock;
1375 		goto out_decl;
1376 	}
1377 
1378 	/* finish worker */
1379 	if (!ism_supported) {
1380 		rc = smc_listen_rdma_finish(new_smc, &cclc,
1381 					    ini.cln_first_contact);
1382 		mutex_unlock(&smc_server_lgr_pending);
1383 		if (rc)
1384 			return;
1385 	}
1386 	smc_conn_save_peer_info(new_smc, &cclc);
1387 	smc_listen_out_connected(new_smc);
1388 	return;
1389 
1390 out_unlock:
1391 	mutex_unlock(&smc_server_lgr_pending);
1392 out_decl:
1393 	smc_listen_decline(new_smc, rc, ini.cln_first_contact);
1394 }
1395 
1396 static void smc_tcp_listen_work(struct work_struct *work)
1397 {
1398 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
1399 					     tcp_listen_work);
1400 	struct sock *lsk = &lsmc->sk;
1401 	struct smc_sock *new_smc;
1402 	int rc = 0;
1403 
1404 	lock_sock(lsk);
1405 	while (lsk->sk_state == SMC_LISTEN) {
1406 		rc = smc_clcsock_accept(lsmc, &new_smc);
1407 		if (rc)
1408 			goto out;
1409 		if (!new_smc)
1410 			continue;
1411 
1412 		new_smc->listen_smc = lsmc;
1413 		new_smc->use_fallback = lsmc->use_fallback;
1414 		new_smc->fallback_rsn = lsmc->fallback_rsn;
1415 		sock_hold(lsk); /* sock_put in smc_listen_work */
1416 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
1417 		smc_copy_sock_settings_to_smc(new_smc);
1418 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
1419 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
1420 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
1421 		if (!schedule_work(&new_smc->smc_listen_work))
1422 			sock_put(&new_smc->sk);
1423 	}
1424 
1425 out:
1426 	release_sock(lsk);
1427 	sock_put(&lsmc->sk); /* sock_hold in smc_listen */
1428 }
1429 
1430 static int smc_listen(struct socket *sock, int backlog)
1431 {
1432 	struct sock *sk = sock->sk;
1433 	struct smc_sock *smc;
1434 	int rc;
1435 
1436 	smc = smc_sk(sk);
1437 	lock_sock(sk);
1438 
1439 	rc = -EINVAL;
1440 	if ((sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) ||
1441 	    smc->connect_nonblock)
1442 		goto out;
1443 
1444 	rc = 0;
1445 	if (sk->sk_state == SMC_LISTEN) {
1446 		sk->sk_max_ack_backlog = backlog;
1447 		goto out;
1448 	}
1449 	/* some socket options are handled in core, so we could not apply
1450 	 * them to the clc socket -- copy smc socket options to clc socket
1451 	 */
1452 	smc_copy_sock_settings_to_clc(smc);
1453 	if (!smc->use_fallback)
1454 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1455 
1456 	rc = kernel_listen(smc->clcsock, backlog);
1457 	if (rc)
1458 		goto out;
1459 	sk->sk_max_ack_backlog = backlog;
1460 	sk->sk_ack_backlog = 0;
1461 	sk->sk_state = SMC_LISTEN;
1462 	sock_hold(sk); /* sock_hold in tcp_listen_worker */
1463 	if (!schedule_work(&smc->tcp_listen_work))
1464 		sock_put(sk);
1465 
1466 out:
1467 	release_sock(sk);
1468 	return rc;
1469 }
1470 
1471 static int smc_accept(struct socket *sock, struct socket *new_sock,
1472 		      int flags, bool kern)
1473 {
1474 	struct sock *sk = sock->sk, *nsk;
1475 	DECLARE_WAITQUEUE(wait, current);
1476 	struct smc_sock *lsmc;
1477 	long timeo;
1478 	int rc = 0;
1479 
1480 	lsmc = smc_sk(sk);
1481 	sock_hold(sk); /* sock_put below */
1482 	lock_sock(sk);
1483 
1484 	if (lsmc->sk.sk_state != SMC_LISTEN) {
1485 		rc = -EINVAL;
1486 		release_sock(sk);
1487 		goto out;
1488 	}
1489 
1490 	/* Wait for an incoming connection */
1491 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1492 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
1493 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1494 		set_current_state(TASK_INTERRUPTIBLE);
1495 		if (!timeo) {
1496 			rc = -EAGAIN;
1497 			break;
1498 		}
1499 		release_sock(sk);
1500 		timeo = schedule_timeout(timeo);
1501 		/* wakeup by sk_data_ready in smc_listen_work() */
1502 		sched_annotate_sleep();
1503 		lock_sock(sk);
1504 		if (signal_pending(current)) {
1505 			rc = sock_intr_errno(timeo);
1506 			break;
1507 		}
1508 	}
1509 	set_current_state(TASK_RUNNING);
1510 	remove_wait_queue(sk_sleep(sk), &wait);
1511 
1512 	if (!rc)
1513 		rc = sock_error(nsk);
1514 	release_sock(sk);
1515 	if (rc)
1516 		goto out;
1517 
1518 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
1519 		/* wait till data arrives on the socket */
1520 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
1521 								MSEC_PER_SEC);
1522 		if (smc_sk(nsk)->use_fallback) {
1523 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
1524 
1525 			lock_sock(clcsk);
1526 			if (skb_queue_empty(&clcsk->sk_receive_queue))
1527 				sk_wait_data(clcsk, &timeo, NULL);
1528 			release_sock(clcsk);
1529 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
1530 			lock_sock(nsk);
1531 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
1532 			release_sock(nsk);
1533 		}
1534 	}
1535 
1536 out:
1537 	sock_put(sk); /* sock_hold above */
1538 	return rc;
1539 }
1540 
1541 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1542 		       int peer)
1543 {
1544 	struct smc_sock *smc;
1545 
1546 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
1547 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
1548 		return -ENOTCONN;
1549 
1550 	smc = smc_sk(sock->sk);
1551 
1552 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
1553 }
1554 
1555 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1556 {
1557 	struct sock *sk = sock->sk;
1558 	struct smc_sock *smc;
1559 	int rc = -EPIPE;
1560 
1561 	smc = smc_sk(sk);
1562 	lock_sock(sk);
1563 	if ((sk->sk_state != SMC_ACTIVE) &&
1564 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1565 	    (sk->sk_state != SMC_INIT))
1566 		goto out;
1567 
1568 	if (msg->msg_flags & MSG_FASTOPEN) {
1569 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
1570 			smc_switch_to_fallback(smc);
1571 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1572 		} else {
1573 			rc = -EINVAL;
1574 			goto out;
1575 		}
1576 	}
1577 
1578 	if (smc->use_fallback)
1579 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
1580 	else
1581 		rc = smc_tx_sendmsg(smc, msg, len);
1582 out:
1583 	release_sock(sk);
1584 	return rc;
1585 }
1586 
1587 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1588 		       int flags)
1589 {
1590 	struct sock *sk = sock->sk;
1591 	struct smc_sock *smc;
1592 	int rc = -ENOTCONN;
1593 
1594 	smc = smc_sk(sk);
1595 	lock_sock(sk);
1596 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
1597 		/* socket was connected before, no more data to read */
1598 		rc = 0;
1599 		goto out;
1600 	}
1601 	if ((sk->sk_state == SMC_INIT) ||
1602 	    (sk->sk_state == SMC_LISTEN) ||
1603 	    (sk->sk_state == SMC_CLOSED))
1604 		goto out;
1605 
1606 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1607 		rc = 0;
1608 		goto out;
1609 	}
1610 
1611 	if (smc->use_fallback) {
1612 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
1613 	} else {
1614 		msg->msg_namelen = 0;
1615 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
1616 	}
1617 
1618 out:
1619 	release_sock(sk);
1620 	return rc;
1621 }
1622 
1623 static __poll_t smc_accept_poll(struct sock *parent)
1624 {
1625 	struct smc_sock *isk = smc_sk(parent);
1626 	__poll_t mask = 0;
1627 
1628 	spin_lock(&isk->accept_q_lock);
1629 	if (!list_empty(&isk->accept_q))
1630 		mask = EPOLLIN | EPOLLRDNORM;
1631 	spin_unlock(&isk->accept_q_lock);
1632 
1633 	return mask;
1634 }
1635 
1636 static __poll_t smc_poll(struct file *file, struct socket *sock,
1637 			     poll_table *wait)
1638 {
1639 	struct sock *sk = sock->sk;
1640 	struct smc_sock *smc;
1641 	__poll_t mask = 0;
1642 
1643 	if (!sk)
1644 		return EPOLLNVAL;
1645 
1646 	smc = smc_sk(sock->sk);
1647 	if (smc->use_fallback) {
1648 		/* delegate to CLC child sock */
1649 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
1650 		sk->sk_err = smc->clcsock->sk->sk_err;
1651 	} else {
1652 		if (sk->sk_state != SMC_CLOSED)
1653 			sock_poll_wait(file, sock, wait);
1654 		if (sk->sk_err)
1655 			mask |= EPOLLERR;
1656 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1657 		    (sk->sk_state == SMC_CLOSED))
1658 			mask |= EPOLLHUP;
1659 		if (sk->sk_state == SMC_LISTEN) {
1660 			/* woken up by sk_data_ready in smc_listen_work() */
1661 			mask |= smc_accept_poll(sk);
1662 		} else if (smc->use_fallback) { /* as result of connect_work()*/
1663 			mask |= smc->clcsock->ops->poll(file, smc->clcsock,
1664 							   wait);
1665 			sk->sk_err = smc->clcsock->sk->sk_err;
1666 		} else {
1667 			if ((sk->sk_state != SMC_INIT &&
1668 			     atomic_read(&smc->conn.sndbuf_space)) ||
1669 			    sk->sk_shutdown & SEND_SHUTDOWN) {
1670 				mask |= EPOLLOUT | EPOLLWRNORM;
1671 			} else {
1672 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1673 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1674 			}
1675 			if (atomic_read(&smc->conn.bytes_to_rcv))
1676 				mask |= EPOLLIN | EPOLLRDNORM;
1677 			if (sk->sk_shutdown & RCV_SHUTDOWN)
1678 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
1679 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
1680 				mask |= EPOLLIN;
1681 			if (smc->conn.urg_state == SMC_URG_VALID)
1682 				mask |= EPOLLPRI;
1683 		}
1684 	}
1685 
1686 	return mask;
1687 }
1688 
1689 static int smc_shutdown(struct socket *sock, int how)
1690 {
1691 	struct sock *sk = sock->sk;
1692 	struct smc_sock *smc;
1693 	int rc = -EINVAL;
1694 	int rc1 = 0;
1695 
1696 	smc = smc_sk(sk);
1697 
1698 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
1699 		return rc;
1700 
1701 	lock_sock(sk);
1702 
1703 	rc = -ENOTCONN;
1704 	if ((sk->sk_state != SMC_ACTIVE) &&
1705 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
1706 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
1707 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1708 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
1709 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
1710 		goto out;
1711 	if (smc->use_fallback) {
1712 		rc = kernel_sock_shutdown(smc->clcsock, how);
1713 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
1714 		if (sk->sk_shutdown == SHUTDOWN_MASK)
1715 			sk->sk_state = SMC_CLOSED;
1716 		goto out;
1717 	}
1718 	switch (how) {
1719 	case SHUT_RDWR:		/* shutdown in both directions */
1720 		rc = smc_close_active(smc);
1721 		break;
1722 	case SHUT_WR:
1723 		rc = smc_close_shutdown_write(smc);
1724 		break;
1725 	case SHUT_RD:
1726 		rc = 0;
1727 		/* nothing more to do because peer is not involved */
1728 		break;
1729 	}
1730 	if (smc->clcsock)
1731 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
1732 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
1733 	sk->sk_shutdown |= how + 1;
1734 
1735 out:
1736 	release_sock(sk);
1737 	return rc ? rc : rc1;
1738 }
1739 
1740 static int smc_setsockopt(struct socket *sock, int level, int optname,
1741 			  char __user *optval, unsigned int optlen)
1742 {
1743 	struct sock *sk = sock->sk;
1744 	struct smc_sock *smc;
1745 	int val, rc;
1746 
1747 	smc = smc_sk(sk);
1748 
1749 	/* generic setsockopts reaching us here always apply to the
1750 	 * CLC socket
1751 	 */
1752 	rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
1753 					   optval, optlen);
1754 	if (smc->clcsock->sk->sk_err) {
1755 		sk->sk_err = smc->clcsock->sk->sk_err;
1756 		sk->sk_error_report(sk);
1757 	}
1758 
1759 	if (optlen < sizeof(int))
1760 		return -EINVAL;
1761 	if (get_user(val, (int __user *)optval))
1762 		return -EFAULT;
1763 
1764 	lock_sock(sk);
1765 	if (rc || smc->use_fallback)
1766 		goto out;
1767 	switch (optname) {
1768 	case TCP_ULP:
1769 	case TCP_FASTOPEN:
1770 	case TCP_FASTOPEN_CONNECT:
1771 	case TCP_FASTOPEN_KEY:
1772 	case TCP_FASTOPEN_NO_COOKIE:
1773 		/* option not supported by SMC */
1774 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
1775 			smc_switch_to_fallback(smc);
1776 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1777 		} else {
1778 			rc = -EINVAL;
1779 		}
1780 		break;
1781 	case TCP_NODELAY:
1782 		if (sk->sk_state != SMC_INIT &&
1783 		    sk->sk_state != SMC_LISTEN &&
1784 		    sk->sk_state != SMC_CLOSED) {
1785 			if (val)
1786 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1787 						 0);
1788 		}
1789 		break;
1790 	case TCP_CORK:
1791 		if (sk->sk_state != SMC_INIT &&
1792 		    sk->sk_state != SMC_LISTEN &&
1793 		    sk->sk_state != SMC_CLOSED) {
1794 			if (!val)
1795 				mod_delayed_work(system_wq, &smc->conn.tx_work,
1796 						 0);
1797 		}
1798 		break;
1799 	case TCP_DEFER_ACCEPT:
1800 		smc->sockopt_defer_accept = val;
1801 		break;
1802 	default:
1803 		break;
1804 	}
1805 out:
1806 	release_sock(sk);
1807 
1808 	return rc;
1809 }
1810 
1811 static int smc_getsockopt(struct socket *sock, int level, int optname,
1812 			  char __user *optval, int __user *optlen)
1813 {
1814 	struct smc_sock *smc;
1815 
1816 	smc = smc_sk(sock->sk);
1817 	/* socket options apply to the CLC socket */
1818 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
1819 					     optval, optlen);
1820 }
1821 
1822 static int smc_ioctl(struct socket *sock, unsigned int cmd,
1823 		     unsigned long arg)
1824 {
1825 	union smc_host_cursor cons, urg;
1826 	struct smc_connection *conn;
1827 	struct smc_sock *smc;
1828 	int answ;
1829 
1830 	smc = smc_sk(sock->sk);
1831 	conn = &smc->conn;
1832 	lock_sock(&smc->sk);
1833 	if (smc->use_fallback) {
1834 		if (!smc->clcsock) {
1835 			release_sock(&smc->sk);
1836 			return -EBADF;
1837 		}
1838 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
1839 		release_sock(&smc->sk);
1840 		return answ;
1841 	}
1842 	switch (cmd) {
1843 	case SIOCINQ: /* same as FIONREAD */
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 = atomic_read(&smc->conn.bytes_to_rcv);
1853 		break;
1854 	case SIOCOUTQ:
1855 		/* output queue size (not send + not acked) */
1856 		if (smc->sk.sk_state == SMC_LISTEN) {
1857 			release_sock(&smc->sk);
1858 			return -EINVAL;
1859 		}
1860 		if (smc->sk.sk_state == SMC_INIT ||
1861 		    smc->sk.sk_state == SMC_CLOSED)
1862 			answ = 0;
1863 		else
1864 			answ = smc->conn.sndbuf_desc->len -
1865 					atomic_read(&smc->conn.sndbuf_space);
1866 		break;
1867 	case SIOCOUTQNSD:
1868 		/* output queue size (not send only) */
1869 		if (smc->sk.sk_state == SMC_LISTEN) {
1870 			release_sock(&smc->sk);
1871 			return -EINVAL;
1872 		}
1873 		if (smc->sk.sk_state == SMC_INIT ||
1874 		    smc->sk.sk_state == SMC_CLOSED)
1875 			answ = 0;
1876 		else
1877 			answ = smc_tx_prepared_sends(&smc->conn);
1878 		break;
1879 	case SIOCATMARK:
1880 		if (smc->sk.sk_state == SMC_LISTEN) {
1881 			release_sock(&smc->sk);
1882 			return -EINVAL;
1883 		}
1884 		if (smc->sk.sk_state == SMC_INIT ||
1885 		    smc->sk.sk_state == SMC_CLOSED) {
1886 			answ = 0;
1887 		} else {
1888 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
1889 			smc_curs_copy(&urg, &conn->urg_curs, conn);
1890 			answ = smc_curs_diff(conn->rmb_desc->len,
1891 					     &cons, &urg) == 1;
1892 		}
1893 		break;
1894 	default:
1895 		release_sock(&smc->sk);
1896 		return -ENOIOCTLCMD;
1897 	}
1898 	release_sock(&smc->sk);
1899 
1900 	return put_user(answ, (int __user *)arg);
1901 }
1902 
1903 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
1904 			    int offset, size_t size, int flags)
1905 {
1906 	struct sock *sk = sock->sk;
1907 	struct smc_sock *smc;
1908 	int rc = -EPIPE;
1909 
1910 	smc = smc_sk(sk);
1911 	lock_sock(sk);
1912 	if (sk->sk_state != SMC_ACTIVE) {
1913 		release_sock(sk);
1914 		goto out;
1915 	}
1916 	release_sock(sk);
1917 	if (smc->use_fallback)
1918 		rc = kernel_sendpage(smc->clcsock, page, offset,
1919 				     size, flags);
1920 	else
1921 		rc = sock_no_sendpage(sock, page, offset, size, flags);
1922 
1923 out:
1924 	return rc;
1925 }
1926 
1927 /* Map the affected portions of the rmbe into an spd, note the number of bytes
1928  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
1929  * updates till whenever a respective page has been fully processed.
1930  * Note that subsequent recv() calls have to wait till all splice() processing
1931  * completed.
1932  */
1933 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
1934 			       struct pipe_inode_info *pipe, size_t len,
1935 			       unsigned int flags)
1936 {
1937 	struct sock *sk = sock->sk;
1938 	struct smc_sock *smc;
1939 	int rc = -ENOTCONN;
1940 
1941 	smc = smc_sk(sk);
1942 	lock_sock(sk);
1943 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
1944 		/* socket was connected before, no more data to read */
1945 		rc = 0;
1946 		goto out;
1947 	}
1948 	if (sk->sk_state == SMC_INIT ||
1949 	    sk->sk_state == SMC_LISTEN ||
1950 	    sk->sk_state == SMC_CLOSED)
1951 		goto out;
1952 
1953 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1954 		rc = 0;
1955 		goto out;
1956 	}
1957 
1958 	if (smc->use_fallback) {
1959 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
1960 						    pipe, len, flags);
1961 	} else {
1962 		if (*ppos) {
1963 			rc = -ESPIPE;
1964 			goto out;
1965 		}
1966 		if (flags & SPLICE_F_NONBLOCK)
1967 			flags = MSG_DONTWAIT;
1968 		else
1969 			flags = 0;
1970 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
1971 	}
1972 out:
1973 	release_sock(sk);
1974 
1975 	return rc;
1976 }
1977 
1978 /* must look like tcp */
1979 static const struct proto_ops smc_sock_ops = {
1980 	.family		= PF_SMC,
1981 	.owner		= THIS_MODULE,
1982 	.release	= smc_release,
1983 	.bind		= smc_bind,
1984 	.connect	= smc_connect,
1985 	.socketpair	= sock_no_socketpair,
1986 	.accept		= smc_accept,
1987 	.getname	= smc_getname,
1988 	.poll		= smc_poll,
1989 	.ioctl		= smc_ioctl,
1990 	.listen		= smc_listen,
1991 	.shutdown	= smc_shutdown,
1992 	.setsockopt	= smc_setsockopt,
1993 	.getsockopt	= smc_getsockopt,
1994 	.sendmsg	= smc_sendmsg,
1995 	.recvmsg	= smc_recvmsg,
1996 	.mmap		= sock_no_mmap,
1997 	.sendpage	= smc_sendpage,
1998 	.splice_read	= smc_splice_read,
1999 };
2000 
2001 static int smc_create(struct net *net, struct socket *sock, int protocol,
2002 		      int kern)
2003 {
2004 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
2005 	struct smc_sock *smc;
2006 	struct sock *sk;
2007 	int rc;
2008 
2009 	rc = -ESOCKTNOSUPPORT;
2010 	if (sock->type != SOCK_STREAM)
2011 		goto out;
2012 
2013 	rc = -EPROTONOSUPPORT;
2014 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
2015 		goto out;
2016 
2017 	rc = -ENOBUFS;
2018 	sock->ops = &smc_sock_ops;
2019 	sk = smc_sock_alloc(net, sock, protocol);
2020 	if (!sk)
2021 		goto out;
2022 
2023 	/* create internal TCP socket for CLC handshake and fallback */
2024 	smc = smc_sk(sk);
2025 	smc->use_fallback = false; /* assume rdma capability first */
2026 	smc->fallback_rsn = 0;
2027 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
2028 			      &smc->clcsock);
2029 	if (rc) {
2030 		sk_common_release(sk);
2031 		goto out;
2032 	}
2033 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
2034 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
2035 
2036 out:
2037 	return rc;
2038 }
2039 
2040 static const struct net_proto_family smc_sock_family_ops = {
2041 	.family	= PF_SMC,
2042 	.owner	= THIS_MODULE,
2043 	.create	= smc_create,
2044 };
2045 
2046 unsigned int smc_net_id;
2047 
2048 static __net_init int smc_net_init(struct net *net)
2049 {
2050 	return smc_pnet_net_init(net);
2051 }
2052 
2053 static void __net_exit smc_net_exit(struct net *net)
2054 {
2055 	smc_pnet_net_exit(net);
2056 }
2057 
2058 static struct pernet_operations smc_net_ops = {
2059 	.init = smc_net_init,
2060 	.exit = smc_net_exit,
2061 	.id   = &smc_net_id,
2062 	.size = sizeof(struct smc_net),
2063 };
2064 
2065 static int __init smc_init(void)
2066 {
2067 	int rc;
2068 
2069 	rc = register_pernet_subsys(&smc_net_ops);
2070 	if (rc)
2071 		return rc;
2072 
2073 	rc = smc_pnet_init();
2074 	if (rc)
2075 		goto out_pernet_subsys;
2076 
2077 	rc = smc_core_init();
2078 	if (rc) {
2079 		pr_err("%s: smc_core_init fails with %d\n", __func__, rc);
2080 		goto out_pnet;
2081 	}
2082 
2083 	rc = smc_llc_init();
2084 	if (rc) {
2085 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
2086 		goto out_core;
2087 	}
2088 
2089 	rc = smc_cdc_init();
2090 	if (rc) {
2091 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
2092 		goto out_core;
2093 	}
2094 
2095 	rc = proto_register(&smc_proto, 1);
2096 	if (rc) {
2097 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
2098 		goto out_core;
2099 	}
2100 
2101 	rc = proto_register(&smc_proto6, 1);
2102 	if (rc) {
2103 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
2104 		goto out_proto;
2105 	}
2106 
2107 	rc = sock_register(&smc_sock_family_ops);
2108 	if (rc) {
2109 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
2110 		goto out_proto6;
2111 	}
2112 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
2113 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
2114 
2115 	rc = smc_ib_register_client();
2116 	if (rc) {
2117 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
2118 		goto out_sock;
2119 	}
2120 
2121 	static_branch_enable(&tcp_have_smc);
2122 	return 0;
2123 
2124 out_sock:
2125 	sock_unregister(PF_SMC);
2126 out_proto6:
2127 	proto_unregister(&smc_proto6);
2128 out_proto:
2129 	proto_unregister(&smc_proto);
2130 out_core:
2131 	smc_core_exit();
2132 out_pnet:
2133 	smc_pnet_exit();
2134 out_pernet_subsys:
2135 	unregister_pernet_subsys(&smc_net_ops);
2136 
2137 	return rc;
2138 }
2139 
2140 static void __exit smc_exit(void)
2141 {
2142 	static_branch_disable(&tcp_have_smc);
2143 	sock_unregister(PF_SMC);
2144 	smc_core_exit();
2145 	smc_ib_unregister_client();
2146 	proto_unregister(&smc_proto6);
2147 	proto_unregister(&smc_proto);
2148 	smc_pnet_exit();
2149 	unregister_pernet_subsys(&smc_net_ops);
2150 	rcu_barrier();
2151 }
2152 
2153 module_init(smc_init);
2154 module_exit(smc_exit);
2155 
2156 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
2157 MODULE_DESCRIPTION("smc socket address family");
2158 MODULE_LICENSE("GPL");
2159 MODULE_ALIAS_NETPROTO(PF_SMC);
2160