Merge tag 'drm-intel-fixes-2017-12-22-1' of git://anongit.freedesktop.org/drm/drm...
[linux-2.6-microblaze.git] / net / smc / af_smc.c
1 /*
2  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
3  *
4  *  AF_SMC protocol family socket handler keeping the AF_INET sock address type
5  *  applies to SOCK_STREAM sockets only
6  *  offers an alternative communication option for TCP-protocol sockets
7  *  applicable with RoCE-cards only
8  *
9  *  Initial restrictions:
10  *    - non-blocking connect postponed
11  *    - IPv6 support postponed
12  *    - support for alternate links postponed
13  *    - partial support for non-blocking sockets only
14  *    - support for urgent data postponed
15  *
16  *  Copyright IBM Corp. 2016
17  *
18  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
19  *              based on prototype from Frank Blaschka
20  */
21
22 #define KMSG_COMPONENT "smc"
23 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
24
25 #include <linux/module.h>
26 #include <linux/socket.h>
27 #include <linux/inetdevice.h>
28 #include <linux/workqueue.h>
29 #include <linux/in.h>
30 #include <linux/sched/signal.h>
31
32 #include <net/sock.h>
33 #include <net/tcp.h>
34 #include <net/smc.h>
35
36 #include "smc.h"
37 #include "smc_clc.h"
38 #include "smc_llc.h"
39 #include "smc_cdc.h"
40 #include "smc_core.h"
41 #include "smc_ib.h"
42 #include "smc_pnet.h"
43 #include "smc_tx.h"
44 #include "smc_rx.h"
45 #include "smc_close.h"
46
47 static DEFINE_MUTEX(smc_create_lgr_pending);    /* serialize link group
48                                                  * creation
49                                                  */
50
51 struct smc_lgr_list smc_lgr_list = {            /* established link groups */
52         .lock = __SPIN_LOCK_UNLOCKED(smc_lgr_list.lock),
53         .list = LIST_HEAD_INIT(smc_lgr_list.list),
54 };
55
56 static void smc_tcp_listen_work(struct work_struct *);
57
58 static void smc_set_keepalive(struct sock *sk, int val)
59 {
60         struct smc_sock *smc = smc_sk(sk);
61
62         smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
63 }
64
65 static struct smc_hashinfo smc_v4_hashinfo = {
66         .lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
67 };
68
69 int smc_hash_sk(struct sock *sk)
70 {
71         struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
72         struct hlist_head *head;
73
74         head = &h->ht;
75
76         write_lock_bh(&h->lock);
77         sk_add_node(sk, head);
78         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
79         write_unlock_bh(&h->lock);
80
81         return 0;
82 }
83 EXPORT_SYMBOL_GPL(smc_hash_sk);
84
85 void smc_unhash_sk(struct sock *sk)
86 {
87         struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
88
89         write_lock_bh(&h->lock);
90         if (sk_del_node_init(sk))
91                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
92         write_unlock_bh(&h->lock);
93 }
94 EXPORT_SYMBOL_GPL(smc_unhash_sk);
95
96 struct proto smc_proto = {
97         .name           = "SMC",
98         .owner          = THIS_MODULE,
99         .keepalive      = smc_set_keepalive,
100         .hash           = smc_hash_sk,
101         .unhash         = smc_unhash_sk,
102         .obj_size       = sizeof(struct smc_sock),
103         .h.smc_hash     = &smc_v4_hashinfo,
104         .slab_flags     = SLAB_TYPESAFE_BY_RCU,
105 };
106 EXPORT_SYMBOL_GPL(smc_proto);
107
108 static int smc_release(struct socket *sock)
109 {
110         struct sock *sk = sock->sk;
111         struct smc_sock *smc;
112         int rc = 0;
113
114         if (!sk)
115                 goto out;
116
117         smc = smc_sk(sk);
118         sock_hold(sk);
119         if (sk->sk_state == SMC_LISTEN)
120                 /* smc_close_non_accepted() is called and acquires
121                  * sock lock for child sockets again
122                  */
123                 lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
124         else
125                 lock_sock(sk);
126
127         if (smc->use_fallback) {
128                 sk->sk_state = SMC_CLOSED;
129                 sk->sk_state_change(sk);
130         } else {
131                 rc = smc_close_active(smc);
132                 sock_set_flag(sk, SOCK_DEAD);
133                 sk->sk_shutdown |= SHUTDOWN_MASK;
134         }
135         if (smc->clcsock) {
136                 sock_release(smc->clcsock);
137                 smc->clcsock = NULL;
138         }
139
140         /* detach socket */
141         sock_orphan(sk);
142         sock->sk = NULL;
143         if (smc->use_fallback) {
144                 schedule_delayed_work(&smc->sock_put_work, TCP_TIMEWAIT_LEN);
145         } else if (sk->sk_state == SMC_CLOSED) {
146                 smc_conn_free(&smc->conn);
147                 schedule_delayed_work(&smc->sock_put_work,
148                                       SMC_CLOSE_SOCK_PUT_DELAY);
149         }
150         release_sock(sk);
151
152         sock_put(sk);
153 out:
154         return rc;
155 }
156
157 static void smc_destruct(struct sock *sk)
158 {
159         if (sk->sk_state != SMC_CLOSED)
160                 return;
161         if (!sock_flag(sk, SOCK_DEAD))
162                 return;
163
164         sk_refcnt_debug_dec(sk);
165 }
166
167 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock)
168 {
169         struct smc_sock *smc;
170         struct sock *sk;
171
172         sk = sk_alloc(net, PF_SMC, GFP_KERNEL, &smc_proto, 0);
173         if (!sk)
174                 return NULL;
175
176         sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
177         sk->sk_state = SMC_INIT;
178         sk->sk_destruct = smc_destruct;
179         sk->sk_protocol = SMCPROTO_SMC;
180         smc = smc_sk(sk);
181         INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
182         INIT_LIST_HEAD(&smc->accept_q);
183         spin_lock_init(&smc->accept_q_lock);
184         INIT_DELAYED_WORK(&smc->sock_put_work, smc_close_sock_put_work);
185         sk->sk_prot->hash(sk);
186         sk_refcnt_debug_inc(sk);
187
188         return sk;
189 }
190
191 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
192                     int addr_len)
193 {
194         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
195         struct sock *sk = sock->sk;
196         struct smc_sock *smc;
197         int rc;
198
199         smc = smc_sk(sk);
200
201         /* replicate tests from inet_bind(), to be safe wrt. future changes */
202         rc = -EINVAL;
203         if (addr_len < sizeof(struct sockaddr_in))
204                 goto out;
205
206         rc = -EAFNOSUPPORT;
207         /* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
208         if ((addr->sin_family != AF_INET) &&
209             ((addr->sin_family != AF_UNSPEC) ||
210              (addr->sin_addr.s_addr != htonl(INADDR_ANY))))
211                 goto out;
212
213         lock_sock(sk);
214
215         /* Check if socket is already active */
216         rc = -EINVAL;
217         if (sk->sk_state != SMC_INIT)
218                 goto out_rel;
219
220         smc->clcsock->sk->sk_reuse = sk->sk_reuse;
221         rc = kernel_bind(smc->clcsock, uaddr, addr_len);
222
223 out_rel:
224         release_sock(sk);
225 out:
226         return rc;
227 }
228
229 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
230                                    unsigned long mask)
231 {
232         /* options we don't get control via setsockopt for */
233         nsk->sk_type = osk->sk_type;
234         nsk->sk_sndbuf = osk->sk_sndbuf;
235         nsk->sk_rcvbuf = osk->sk_rcvbuf;
236         nsk->sk_sndtimeo = osk->sk_sndtimeo;
237         nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
238         nsk->sk_mark = osk->sk_mark;
239         nsk->sk_priority = osk->sk_priority;
240         nsk->sk_rcvlowat = osk->sk_rcvlowat;
241         nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
242         nsk->sk_err = osk->sk_err;
243
244         nsk->sk_flags &= ~mask;
245         nsk->sk_flags |= osk->sk_flags & mask;
246 }
247
248 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
249                              (1UL << SOCK_KEEPOPEN) | \
250                              (1UL << SOCK_LINGER) | \
251                              (1UL << SOCK_BROADCAST) | \
252                              (1UL << SOCK_TIMESTAMP) | \
253                              (1UL << SOCK_DBG) | \
254                              (1UL << SOCK_RCVTSTAMP) | \
255                              (1UL << SOCK_RCVTSTAMPNS) | \
256                              (1UL << SOCK_LOCALROUTE) | \
257                              (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
258                              (1UL << SOCK_RXQ_OVFL) | \
259                              (1UL << SOCK_WIFI_STATUS) | \
260                              (1UL << SOCK_NOFCS) | \
261                              (1UL << SOCK_FILTER_LOCKED))
262 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
263  * clc socket (since smc is not called for these options from net/core)
264  */
265 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
266 {
267         smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
268 }
269
270 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
271                              (1UL << SOCK_KEEPOPEN) | \
272                              (1UL << SOCK_LINGER) | \
273                              (1UL << SOCK_DBG))
274 /* copy only settings and flags relevant for smc from clc to smc socket */
275 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
276 {
277         smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
278 }
279
280 /* determine subnet and mask of internal TCP socket */
281 int smc_netinfo_by_tcpsk(struct socket *clcsock,
282                          __be32 *subnet, u8 *prefix_len)
283 {
284         struct dst_entry *dst = sk_dst_get(clcsock->sk);
285         struct in_device *in_dev;
286         struct sockaddr_in addr;
287         int rc = -ENOENT;
288         int len;
289
290         if (!dst) {
291                 rc = -ENOTCONN;
292                 goto out;
293         }
294         if (!dst->dev) {
295                 rc = -ENODEV;
296                 goto out_rel;
297         }
298
299         /* get address to which the internal TCP socket is bound */
300         kernel_getsockname(clcsock, (struct sockaddr *)&addr, &len);
301         /* analyze IPv4 specific data of net_device belonging to TCP socket */
302         rcu_read_lock();
303         in_dev = __in_dev_get_rcu(dst->dev);
304         for_ifa(in_dev) {
305                 if (!inet_ifa_match(addr.sin_addr.s_addr, ifa))
306                         continue;
307                 *prefix_len = inet_mask_len(ifa->ifa_mask);
308                 *subnet = ifa->ifa_address & ifa->ifa_mask;
309                 rc = 0;
310                 break;
311         } endfor_ifa(in_dev);
312         rcu_read_unlock();
313
314 out_rel:
315         dst_release(dst);
316 out:
317         return rc;
318 }
319
320 static int smc_clnt_conf_first_link(struct smc_sock *smc, union ib_gid *gid)
321 {
322         struct smc_link_group *lgr = smc->conn.lgr;
323         struct smc_link *link;
324         int rest;
325         int rc;
326
327         link = &lgr->lnk[SMC_SINGLE_LINK];
328         /* receive CONFIRM LINK request from server over RoCE fabric */
329         rest = wait_for_completion_interruptible_timeout(
330                 &link->llc_confirm,
331                 SMC_LLC_WAIT_FIRST_TIME);
332         if (rest <= 0) {
333                 struct smc_clc_msg_decline dclc;
334
335                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
336                                       SMC_CLC_DECLINE);
337                 return rc;
338         }
339
340         rc = smc_ib_modify_qp_rts(link);
341         if (rc)
342                 return SMC_CLC_DECL_INTERR;
343
344         smc_wr_remember_qp_attr(link);
345
346         rc = smc_wr_reg_send(link,
347                              smc->conn.rmb_desc->mr_rx[SMC_SINGLE_LINK]);
348         if (rc)
349                 return SMC_CLC_DECL_INTERR;
350
351         /* send CONFIRM LINK response over RoCE fabric */
352         rc = smc_llc_send_confirm_link(link,
353                                        link->smcibdev->mac[link->ibport - 1],
354                                        gid, SMC_LLC_RESP);
355         if (rc < 0)
356                 return SMC_CLC_DECL_TCL;
357
358         return rc;
359 }
360
361 static void smc_conn_save_peer_info(struct smc_sock *smc,
362                                     struct smc_clc_msg_accept_confirm *clc)
363 {
364         smc->conn.peer_conn_idx = clc->conn_idx;
365         smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
366         smc->conn.peer_rmbe_size = smc_uncompress_bufsize(clc->rmbe_size);
367         atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
368 }
369
370 static void smc_link_save_peer_info(struct smc_link *link,
371                                     struct smc_clc_msg_accept_confirm *clc)
372 {
373         link->peer_qpn = ntoh24(clc->qpn);
374         memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
375         memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
376         link->peer_psn = ntoh24(clc->psn);
377         link->peer_mtu = clc->qp_mtu;
378 }
379
380 /* setup for RDMA connection of client */
381 static int smc_connect_rdma(struct smc_sock *smc)
382 {
383         struct sockaddr_in *inaddr = (struct sockaddr_in *)smc->addr;
384         struct smc_clc_msg_accept_confirm aclc;
385         int local_contact = SMC_FIRST_CONTACT;
386         struct smc_ib_device *smcibdev;
387         struct smc_link *link;
388         u8 srv_first_contact;
389         int reason_code = 0;
390         int rc = 0;
391         u8 ibport;
392
393         if (!tcp_sk(smc->clcsock->sk)->syn_smc) {
394                 /* peer has not signalled SMC-capability */
395                 smc->use_fallback = true;
396                 goto out_connected;
397         }
398
399         /* IPSec connections opt out of SMC-R optimizations */
400         if (using_ipsec(smc)) {
401                 reason_code = SMC_CLC_DECL_IPSEC;
402                 goto decline_rdma;
403         }
404
405         /* PNET table look up: search active ib_device and port
406          * within same PNETID that also contains the ethernet device
407          * used for the internal TCP socket
408          */
409         smc_pnet_find_roce_resource(smc->clcsock->sk, &smcibdev, &ibport);
410         if (!smcibdev) {
411                 reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
412                 goto decline_rdma;
413         }
414
415         /* do inband token exchange */
416         reason_code = smc_clc_send_proposal(smc, smcibdev, ibport);
417         if (reason_code < 0) {
418                 rc = reason_code;
419                 goto out_err;
420         }
421         if (reason_code > 0) /* configuration error */
422                 goto decline_rdma;
423         /* receive SMC Accept CLC message */
424         reason_code = smc_clc_wait_msg(smc, &aclc, sizeof(aclc),
425                                        SMC_CLC_ACCEPT);
426         if (reason_code < 0) {
427                 rc = reason_code;
428                 goto out_err;
429         }
430         if (reason_code > 0)
431                 goto decline_rdma;
432
433         srv_first_contact = aclc.hdr.flag;
434         mutex_lock(&smc_create_lgr_pending);
435         local_contact = smc_conn_create(smc, inaddr->sin_addr.s_addr, smcibdev,
436                                         ibport, &aclc.lcl, srv_first_contact);
437         if (local_contact < 0) {
438                 rc = local_contact;
439                 if (rc == -ENOMEM)
440                         reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
441                 else if (rc == -ENOLINK)
442                         reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
443                 goto decline_rdma_unlock;
444         }
445         link = &smc->conn.lgr->lnk[SMC_SINGLE_LINK];
446
447         smc_conn_save_peer_info(smc, &aclc);
448
449         /* create send buffer and rmb */
450         rc = smc_buf_create(smc);
451         if (rc) {
452                 reason_code = SMC_CLC_DECL_MEM;
453                 goto decline_rdma_unlock;
454         }
455
456         if (local_contact == SMC_FIRST_CONTACT)
457                 smc_link_save_peer_info(link, &aclc);
458
459         rc = smc_rmb_rtoken_handling(&smc->conn, &aclc);
460         if (rc) {
461                 reason_code = SMC_CLC_DECL_INTERR;
462                 goto decline_rdma_unlock;
463         }
464
465         smc_close_init(smc);
466         smc_rx_init(smc);
467
468         if (local_contact == SMC_FIRST_CONTACT) {
469                 rc = smc_ib_ready_link(link);
470                 if (rc) {
471                         reason_code = SMC_CLC_DECL_INTERR;
472                         goto decline_rdma_unlock;
473                 }
474         } else {
475                 struct smc_buf_desc *buf_desc = smc->conn.rmb_desc;
476
477                 if (!buf_desc->reused) {
478                         /* register memory region for new rmb */
479                         rc = smc_wr_reg_send(link,
480                                              buf_desc->mr_rx[SMC_SINGLE_LINK]);
481                         if (rc) {
482                                 reason_code = SMC_CLC_DECL_INTERR;
483                                 goto decline_rdma_unlock;
484                         }
485                 }
486         }
487         smc_rmb_sync_sg_for_device(&smc->conn);
488
489         rc = smc_clc_send_confirm(smc);
490         if (rc)
491                 goto out_err_unlock;
492
493         if (local_contact == SMC_FIRST_CONTACT) {
494                 /* QP confirmation over RoCE fabric */
495                 reason_code = smc_clnt_conf_first_link(
496                         smc, &smcibdev->gid[ibport - 1]);
497                 if (reason_code < 0) {
498                         rc = reason_code;
499                         goto out_err_unlock;
500                 }
501                 if (reason_code > 0)
502                         goto decline_rdma_unlock;
503         }
504
505         mutex_unlock(&smc_create_lgr_pending);
506         smc_tx_init(smc);
507
508 out_connected:
509         smc_copy_sock_settings_to_clc(smc);
510         if (smc->sk.sk_state == SMC_INIT)
511                 smc->sk.sk_state = SMC_ACTIVE;
512
513         return rc ? rc : local_contact;
514
515 decline_rdma_unlock:
516         mutex_unlock(&smc_create_lgr_pending);
517         smc_conn_free(&smc->conn);
518 decline_rdma:
519         /* RDMA setup failed, switch back to TCP */
520         smc->use_fallback = true;
521         if (reason_code && (reason_code != SMC_CLC_DECL_REPLY)) {
522                 rc = smc_clc_send_decline(smc, reason_code);
523                 if (rc < sizeof(struct smc_clc_msg_decline))
524                         goto out_err;
525         }
526         goto out_connected;
527
528 out_err_unlock:
529         mutex_unlock(&smc_create_lgr_pending);
530         smc_conn_free(&smc->conn);
531 out_err:
532         return rc;
533 }
534
535 static int smc_connect(struct socket *sock, struct sockaddr *addr,
536                        int alen, int flags)
537 {
538         struct sock *sk = sock->sk;
539         struct smc_sock *smc;
540         int rc = -EINVAL;
541
542         smc = smc_sk(sk);
543
544         /* separate smc parameter checking to be safe */
545         if (alen < sizeof(addr->sa_family))
546                 goto out_err;
547         if (addr->sa_family != AF_INET)
548                 goto out_err;
549         smc->addr = addr;       /* needed for nonblocking connect */
550
551         lock_sock(sk);
552         switch (sk->sk_state) {
553         default:
554                 goto out;
555         case SMC_ACTIVE:
556                 rc = -EISCONN;
557                 goto out;
558         case SMC_INIT:
559                 rc = 0;
560                 break;
561         }
562
563         smc_copy_sock_settings_to_clc(smc);
564         tcp_sk(smc->clcsock->sk)->syn_smc = 1;
565         rc = kernel_connect(smc->clcsock, addr, alen, flags);
566         if (rc)
567                 goto out;
568
569         /* setup RDMA connection */
570         rc = smc_connect_rdma(smc);
571         if (rc < 0)
572                 goto out;
573         else
574                 rc = 0; /* success cases including fallback */
575
576 out:
577         release_sock(sk);
578 out_err:
579         return rc;
580 }
581
582 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
583 {
584         struct sock *sk = &lsmc->sk;
585         struct socket *new_clcsock;
586         struct sock *new_sk;
587         int rc;
588
589         release_sock(&lsmc->sk);
590         new_sk = smc_sock_alloc(sock_net(sk), NULL);
591         if (!new_sk) {
592                 rc = -ENOMEM;
593                 lsmc->sk.sk_err = ENOMEM;
594                 *new_smc = NULL;
595                 lock_sock(&lsmc->sk);
596                 goto out;
597         }
598         *new_smc = smc_sk(new_sk);
599
600         rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
601         lock_sock(&lsmc->sk);
602         if  (rc < 0) {
603                 lsmc->sk.sk_err = -rc;
604                 new_sk->sk_state = SMC_CLOSED;
605                 sock_set_flag(new_sk, SOCK_DEAD);
606                 sk->sk_prot->unhash(new_sk);
607                 sock_put(new_sk);
608                 *new_smc = NULL;
609                 goto out;
610         }
611         if (lsmc->sk.sk_state == SMC_CLOSED) {
612                 if (new_clcsock)
613                         sock_release(new_clcsock);
614                 new_sk->sk_state = SMC_CLOSED;
615                 sock_set_flag(new_sk, SOCK_DEAD);
616                 sk->sk_prot->unhash(new_sk);
617                 sock_put(new_sk);
618                 *new_smc = NULL;
619                 goto out;
620         }
621
622         (*new_smc)->clcsock = new_clcsock;
623 out:
624         return rc;
625 }
626
627 /* add a just created sock to the accept queue of the listen sock as
628  * candidate for a following socket accept call from user space
629  */
630 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
631 {
632         struct smc_sock *par = smc_sk(parent);
633
634         sock_hold(sk);
635         spin_lock(&par->accept_q_lock);
636         list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
637         spin_unlock(&par->accept_q_lock);
638         sk_acceptq_added(parent);
639 }
640
641 /* remove a socket from the accept queue of its parental listening socket */
642 static void smc_accept_unlink(struct sock *sk)
643 {
644         struct smc_sock *par = smc_sk(sk)->listen_smc;
645
646         spin_lock(&par->accept_q_lock);
647         list_del_init(&smc_sk(sk)->accept_q);
648         spin_unlock(&par->accept_q_lock);
649         sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
650         sock_put(sk);
651 }
652
653 /* remove a sock from the accept queue to bind it to a new socket created
654  * for a socket accept call from user space
655  */
656 struct sock *smc_accept_dequeue(struct sock *parent,
657                                 struct socket *new_sock)
658 {
659         struct smc_sock *isk, *n;
660         struct sock *new_sk;
661
662         list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
663                 new_sk = (struct sock *)isk;
664
665                 smc_accept_unlink(new_sk);
666                 if (new_sk->sk_state == SMC_CLOSED) {
667                         new_sk->sk_prot->unhash(new_sk);
668                         sock_put(new_sk);
669                         continue;
670                 }
671                 if (new_sock)
672                         sock_graft(new_sk, new_sock);
673                 return new_sk;
674         }
675         return NULL;
676 }
677
678 /* clean up for a created but never accepted sock */
679 void smc_close_non_accepted(struct sock *sk)
680 {
681         struct smc_sock *smc = smc_sk(sk);
682
683         sock_hold(sk);
684         lock_sock(sk);
685         if (!sk->sk_lingertime)
686                 /* wait for peer closing */
687                 sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
688         if (smc->use_fallback) {
689                 sk->sk_state = SMC_CLOSED;
690         } else {
691                 smc_close_active(smc);
692                 sock_set_flag(sk, SOCK_DEAD);
693                 sk->sk_shutdown |= SHUTDOWN_MASK;
694         }
695         if (smc->clcsock) {
696                 struct socket *tcp;
697
698                 tcp = smc->clcsock;
699                 smc->clcsock = NULL;
700                 sock_release(tcp);
701         }
702         if (smc->use_fallback) {
703                 schedule_delayed_work(&smc->sock_put_work, TCP_TIMEWAIT_LEN);
704         } else if (sk->sk_state == SMC_CLOSED) {
705                 smc_conn_free(&smc->conn);
706                 schedule_delayed_work(&smc->sock_put_work,
707                                       SMC_CLOSE_SOCK_PUT_DELAY);
708         }
709         release_sock(sk);
710         sock_put(sk);
711 }
712
713 static int smc_serv_conf_first_link(struct smc_sock *smc)
714 {
715         struct smc_link_group *lgr = smc->conn.lgr;
716         struct smc_link *link;
717         int rest;
718         int rc;
719
720         link = &lgr->lnk[SMC_SINGLE_LINK];
721
722         rc = smc_wr_reg_send(link,
723                              smc->conn.rmb_desc->mr_rx[SMC_SINGLE_LINK]);
724         if (rc)
725                 return SMC_CLC_DECL_INTERR;
726
727         /* send CONFIRM LINK request to client over the RoCE fabric */
728         rc = smc_llc_send_confirm_link(link,
729                                        link->smcibdev->mac[link->ibport - 1],
730                                        &link->smcibdev->gid[link->ibport - 1],
731                                        SMC_LLC_REQ);
732         if (rc < 0)
733                 return SMC_CLC_DECL_TCL;
734
735         /* receive CONFIRM LINK response from client over the RoCE fabric */
736         rest = wait_for_completion_interruptible_timeout(
737                 &link->llc_confirm_resp,
738                 SMC_LLC_WAIT_FIRST_TIME);
739         if (rest <= 0) {
740                 struct smc_clc_msg_decline dclc;
741
742                 rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
743                                       SMC_CLC_DECLINE);
744         }
745
746         return rc;
747 }
748
749 /* setup for RDMA connection of server */
750 static void smc_listen_work(struct work_struct *work)
751 {
752         struct smc_sock *new_smc = container_of(work, struct smc_sock,
753                                                 smc_listen_work);
754         struct socket *newclcsock = new_smc->clcsock;
755         struct smc_sock *lsmc = new_smc->listen_smc;
756         struct smc_clc_msg_accept_confirm cclc;
757         int local_contact = SMC_REUSE_CONTACT;
758         struct sock *newsmcsk = &new_smc->sk;
759         struct smc_clc_msg_proposal pclc;
760         struct smc_ib_device *smcibdev;
761         struct sockaddr_in peeraddr;
762         struct smc_link *link;
763         int reason_code = 0;
764         int rc = 0, len;
765         __be32 subnet;
766         u8 prefix_len;
767         u8 ibport;
768
769         /* check if peer is smc capable */
770         if (!tcp_sk(newclcsock->sk)->syn_smc) {
771                 new_smc->use_fallback = true;
772                 goto out_connected;
773         }
774
775         /* do inband token exchange -
776          *wait for and receive SMC Proposal CLC message
777          */
778         reason_code = smc_clc_wait_msg(new_smc, &pclc, sizeof(pclc),
779                                        SMC_CLC_PROPOSAL);
780         if (reason_code < 0)
781                 goto out_err;
782         if (reason_code > 0)
783                 goto decline_rdma;
784
785         /* IPSec connections opt out of SMC-R optimizations */
786         if (using_ipsec(new_smc)) {
787                 reason_code = SMC_CLC_DECL_IPSEC;
788                 goto decline_rdma;
789         }
790
791         /* PNET table look up: search active ib_device and port
792          * within same PNETID that also contains the ethernet device
793          * used for the internal TCP socket
794          */
795         smc_pnet_find_roce_resource(newclcsock->sk, &smcibdev, &ibport);
796         if (!smcibdev) {
797                 reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
798                 goto decline_rdma;
799         }
800
801         /* determine subnet and mask from internal TCP socket */
802         rc = smc_netinfo_by_tcpsk(newclcsock, &subnet, &prefix_len);
803         if (rc) {
804                 reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
805                 goto decline_rdma;
806         }
807         if ((pclc.outgoing_subnet != subnet) ||
808             (pclc.prefix_len != prefix_len)) {
809                 reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
810                 goto decline_rdma;
811         }
812
813         /* get address of the peer connected to the internal TCP socket */
814         kernel_getpeername(newclcsock, (struct sockaddr *)&peeraddr, &len);
815
816         /* allocate connection / link group */
817         mutex_lock(&smc_create_lgr_pending);
818         local_contact = smc_conn_create(new_smc, peeraddr.sin_addr.s_addr,
819                                         smcibdev, ibport, &pclc.lcl, 0);
820         if (local_contact < 0) {
821                 rc = local_contact;
822                 if (rc == -ENOMEM)
823                         reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
824                 goto decline_rdma_unlock;
825         }
826         link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
827
828         /* create send buffer and rmb */
829         rc = smc_buf_create(new_smc);
830         if (rc) {
831                 reason_code = SMC_CLC_DECL_MEM;
832                 goto decline_rdma_unlock;
833         }
834
835         smc_close_init(new_smc);
836         smc_rx_init(new_smc);
837
838         if (local_contact != SMC_FIRST_CONTACT) {
839                 struct smc_buf_desc *buf_desc = new_smc->conn.rmb_desc;
840
841                 if (!buf_desc->reused) {
842                         /* register memory region for new rmb */
843                         rc = smc_wr_reg_send(link,
844                                              buf_desc->mr_rx[SMC_SINGLE_LINK]);
845                         if (rc) {
846                                 reason_code = SMC_CLC_DECL_INTERR;
847                                 goto decline_rdma_unlock;
848                         }
849                 }
850         }
851         smc_rmb_sync_sg_for_device(&new_smc->conn);
852
853         rc = smc_clc_send_accept(new_smc, local_contact);
854         if (rc)
855                 goto out_err_unlock;
856
857         /* receive SMC Confirm CLC message */
858         reason_code = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
859                                        SMC_CLC_CONFIRM);
860         if (reason_code < 0)
861                 goto out_err_unlock;
862         if (reason_code > 0)
863                 goto decline_rdma_unlock;
864         smc_conn_save_peer_info(new_smc, &cclc);
865         if (local_contact == SMC_FIRST_CONTACT)
866                 smc_link_save_peer_info(link, &cclc);
867
868         rc = smc_rmb_rtoken_handling(&new_smc->conn, &cclc);
869         if (rc) {
870                 reason_code = SMC_CLC_DECL_INTERR;
871                 goto decline_rdma_unlock;
872         }
873
874         if (local_contact == SMC_FIRST_CONTACT) {
875                 rc = smc_ib_ready_link(link);
876                 if (rc) {
877                         reason_code = SMC_CLC_DECL_INTERR;
878                         goto decline_rdma_unlock;
879                 }
880                 /* QP confirmation over RoCE fabric */
881                 reason_code = smc_serv_conf_first_link(new_smc);
882                 if (reason_code < 0) {
883                         /* peer is not aware of a problem */
884                         rc = reason_code;
885                         goto out_err_unlock;
886                 }
887                 if (reason_code > 0)
888                         goto decline_rdma_unlock;
889         }
890
891         smc_tx_init(new_smc);
892         mutex_unlock(&smc_create_lgr_pending);
893
894 out_connected:
895         sk_refcnt_debug_inc(newsmcsk);
896         if (newsmcsk->sk_state == SMC_INIT)
897                 newsmcsk->sk_state = SMC_ACTIVE;
898 enqueue:
899         lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
900         if (lsmc->sk.sk_state == SMC_LISTEN) {
901                 smc_accept_enqueue(&lsmc->sk, newsmcsk);
902         } else { /* no longer listening */
903                 smc_close_non_accepted(newsmcsk);
904         }
905         release_sock(&lsmc->sk);
906
907         /* Wake up accept */
908         lsmc->sk.sk_data_ready(&lsmc->sk);
909         sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
910         return;
911
912 decline_rdma_unlock:
913         mutex_unlock(&smc_create_lgr_pending);
914 decline_rdma:
915         /* RDMA setup failed, switch back to TCP */
916         smc_conn_free(&new_smc->conn);
917         new_smc->use_fallback = true;
918         if (reason_code && (reason_code != SMC_CLC_DECL_REPLY)) {
919                 rc = smc_clc_send_decline(new_smc, reason_code);
920                 if (rc < sizeof(struct smc_clc_msg_decline))
921                         goto out_err;
922         }
923         goto out_connected;
924
925 out_err_unlock:
926         mutex_unlock(&smc_create_lgr_pending);
927 out_err:
928         newsmcsk->sk_state = SMC_CLOSED;
929         smc_conn_free(&new_smc->conn);
930         goto enqueue; /* queue new sock with sk_err set */
931 }
932
933 static void smc_tcp_listen_work(struct work_struct *work)
934 {
935         struct smc_sock *lsmc = container_of(work, struct smc_sock,
936                                              tcp_listen_work);
937         struct smc_sock *new_smc;
938         int rc = 0;
939
940         lock_sock(&lsmc->sk);
941         while (lsmc->sk.sk_state == SMC_LISTEN) {
942                 rc = smc_clcsock_accept(lsmc, &new_smc);
943                 if (rc)
944                         goto out;
945                 if (!new_smc)
946                         continue;
947
948                 new_smc->listen_smc = lsmc;
949                 new_smc->use_fallback = false; /* assume rdma capability first*/
950                 sock_hold(&lsmc->sk); /* sock_put in smc_listen_work */
951                 INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
952                 smc_copy_sock_settings_to_smc(new_smc);
953                 schedule_work(&new_smc->smc_listen_work);
954         }
955
956 out:
957         release_sock(&lsmc->sk);
958         lsmc->sk.sk_data_ready(&lsmc->sk); /* no more listening, wake accept */
959 }
960
961 static int smc_listen(struct socket *sock, int backlog)
962 {
963         struct sock *sk = sock->sk;
964         struct smc_sock *smc;
965         int rc;
966
967         smc = smc_sk(sk);
968         lock_sock(sk);
969
970         rc = -EINVAL;
971         if ((sk->sk_state != SMC_INIT) && (sk->sk_state != SMC_LISTEN))
972                 goto out;
973
974         rc = 0;
975         if (sk->sk_state == SMC_LISTEN) {
976                 sk->sk_max_ack_backlog = backlog;
977                 goto out;
978         }
979         /* some socket options are handled in core, so we could not apply
980          * them to the clc socket -- copy smc socket options to clc socket
981          */
982         smc_copy_sock_settings_to_clc(smc);
983         tcp_sk(smc->clcsock->sk)->syn_smc = 1;
984
985         rc = kernel_listen(smc->clcsock, backlog);
986         if (rc)
987                 goto out;
988         sk->sk_max_ack_backlog = backlog;
989         sk->sk_ack_backlog = 0;
990         sk->sk_state = SMC_LISTEN;
991         INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
992         schedule_work(&smc->tcp_listen_work);
993
994 out:
995         release_sock(sk);
996         return rc;
997 }
998
999 static int smc_accept(struct socket *sock, struct socket *new_sock,
1000                       int flags, bool kern)
1001 {
1002         struct sock *sk = sock->sk, *nsk;
1003         DECLARE_WAITQUEUE(wait, current);
1004         struct smc_sock *lsmc;
1005         long timeo;
1006         int rc = 0;
1007
1008         lsmc = smc_sk(sk);
1009         lock_sock(sk);
1010
1011         if (lsmc->sk.sk_state != SMC_LISTEN) {
1012                 rc = -EINVAL;
1013                 goto out;
1014         }
1015
1016         /* Wait for an incoming connection */
1017         timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1018         add_wait_queue_exclusive(sk_sleep(sk), &wait);
1019         while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1020                 set_current_state(TASK_INTERRUPTIBLE);
1021                 if (!timeo) {
1022                         rc = -EAGAIN;
1023                         break;
1024                 }
1025                 release_sock(sk);
1026                 timeo = schedule_timeout(timeo);
1027                 /* wakeup by sk_data_ready in smc_listen_work() */
1028                 sched_annotate_sleep();
1029                 lock_sock(sk);
1030                 if (signal_pending(current)) {
1031                         rc = sock_intr_errno(timeo);
1032                         break;
1033                 }
1034         }
1035         set_current_state(TASK_RUNNING);
1036         remove_wait_queue(sk_sleep(sk), &wait);
1037
1038         if (!rc)
1039                 rc = sock_error(nsk);
1040
1041 out:
1042         release_sock(sk);
1043         return rc;
1044 }
1045
1046 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1047                        int *len, int peer)
1048 {
1049         struct smc_sock *smc;
1050
1051         if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
1052             (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
1053                 return -ENOTCONN;
1054
1055         smc = smc_sk(sock->sk);
1056
1057         return smc->clcsock->ops->getname(smc->clcsock, addr, len, peer);
1058 }
1059
1060 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1061 {
1062         struct sock *sk = sock->sk;
1063         struct smc_sock *smc;
1064         int rc = -EPIPE;
1065
1066         smc = smc_sk(sk);
1067         lock_sock(sk);
1068         if ((sk->sk_state != SMC_ACTIVE) &&
1069             (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1070             (sk->sk_state != SMC_INIT))
1071                 goto out;
1072         if (smc->use_fallback)
1073                 rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
1074         else
1075                 rc = smc_tx_sendmsg(smc, msg, len);
1076 out:
1077         release_sock(sk);
1078         return rc;
1079 }
1080
1081 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1082                        int flags)
1083 {
1084         struct sock *sk = sock->sk;
1085         struct smc_sock *smc;
1086         int rc = -ENOTCONN;
1087
1088         smc = smc_sk(sk);
1089         lock_sock(sk);
1090         if ((sk->sk_state == SMC_INIT) ||
1091             (sk->sk_state == SMC_LISTEN) ||
1092             (sk->sk_state == SMC_CLOSED))
1093                 goto out;
1094
1095         if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
1096                 rc = 0;
1097                 goto out;
1098         }
1099
1100         if (smc->use_fallback)
1101                 rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
1102         else
1103                 rc = smc_rx_recvmsg(smc, msg, len, flags);
1104
1105 out:
1106         release_sock(sk);
1107         return rc;
1108 }
1109
1110 static unsigned int smc_accept_poll(struct sock *parent)
1111 {
1112         struct smc_sock *isk;
1113         struct sock *sk;
1114
1115         lock_sock(parent);
1116         list_for_each_entry(isk, &smc_sk(parent)->accept_q, accept_q) {
1117                 sk = (struct sock *)isk;
1118
1119                 if (sk->sk_state == SMC_ACTIVE) {
1120                         release_sock(parent);
1121                         return POLLIN | POLLRDNORM;
1122                 }
1123         }
1124         release_sock(parent);
1125
1126         return 0;
1127 }
1128
1129 static unsigned int smc_poll(struct file *file, struct socket *sock,
1130                              poll_table *wait)
1131 {
1132         struct sock *sk = sock->sk;
1133         unsigned int mask = 0;
1134         struct smc_sock *smc;
1135         int rc;
1136
1137         smc = smc_sk(sock->sk);
1138         if ((sk->sk_state == SMC_INIT) || smc->use_fallback) {
1139                 /* delegate to CLC child sock */
1140                 mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
1141                 /* if non-blocking connect finished ... */
1142                 lock_sock(sk);
1143                 if ((sk->sk_state == SMC_INIT) && (mask & POLLOUT)) {
1144                         sk->sk_err = smc->clcsock->sk->sk_err;
1145                         if (sk->sk_err) {
1146                                 mask |= POLLERR;
1147                         } else {
1148                                 rc = smc_connect_rdma(smc);
1149                                 if (rc < 0)
1150                                         mask |= POLLERR;
1151                                 else
1152                                         /* success cases including fallback */
1153                                         mask |= POLLOUT | POLLWRNORM;
1154                         }
1155                 }
1156                 release_sock(sk);
1157         } else {
1158                 sock_poll_wait(file, sk_sleep(sk), wait);
1159                 if (sk->sk_state == SMC_LISTEN)
1160                         /* woken up by sk_data_ready in smc_listen_work() */
1161                         mask |= smc_accept_poll(sk);
1162                 if (sk->sk_err)
1163                         mask |= POLLERR;
1164                 if (atomic_read(&smc->conn.sndbuf_space) ||
1165                     (sk->sk_shutdown & SEND_SHUTDOWN)) {
1166                         mask |= POLLOUT | POLLWRNORM;
1167                 } else {
1168                         sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1169                         set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1170                 }
1171                 if (atomic_read(&smc->conn.bytes_to_rcv))
1172                         mask |= POLLIN | POLLRDNORM;
1173                 if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1174                     (sk->sk_state == SMC_CLOSED))
1175                         mask |= POLLHUP;
1176                 if (sk->sk_shutdown & RCV_SHUTDOWN)
1177                         mask |= POLLIN | POLLRDNORM | POLLRDHUP;
1178                 if (sk->sk_state == SMC_APPCLOSEWAIT1)
1179                         mask |= POLLIN;
1180
1181         }
1182
1183         return mask;
1184 }
1185
1186 static int smc_shutdown(struct socket *sock, int how)
1187 {
1188         struct sock *sk = sock->sk;
1189         struct smc_sock *smc;
1190         int rc = -EINVAL;
1191         int rc1 = 0;
1192
1193         smc = smc_sk(sk);
1194
1195         if ((how < SHUT_RD) || (how > SHUT_RDWR))
1196                 return rc;
1197
1198         lock_sock(sk);
1199
1200         rc = -ENOTCONN;
1201         if ((sk->sk_state != SMC_LISTEN) &&
1202             (sk->sk_state != SMC_ACTIVE) &&
1203             (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
1204             (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
1205             (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1206             (sk->sk_state != SMC_APPCLOSEWAIT2) &&
1207             (sk->sk_state != SMC_APPFINCLOSEWAIT))
1208                 goto out;
1209         if (smc->use_fallback) {
1210                 rc = kernel_sock_shutdown(smc->clcsock, how);
1211                 sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
1212                 if (sk->sk_shutdown == SHUTDOWN_MASK)
1213                         sk->sk_state = SMC_CLOSED;
1214                 goto out;
1215         }
1216         switch (how) {
1217         case SHUT_RDWR:         /* shutdown in both directions */
1218                 rc = smc_close_active(smc);
1219                 break;
1220         case SHUT_WR:
1221                 rc = smc_close_shutdown_write(smc);
1222                 break;
1223         case SHUT_RD:
1224                 if (sk->sk_state == SMC_LISTEN)
1225                         rc = smc_close_active(smc);
1226                 else
1227                         rc = 0;
1228                         /* nothing more to do because peer is not involved */
1229                 break;
1230         }
1231         rc1 = kernel_sock_shutdown(smc->clcsock, how);
1232         /* map sock_shutdown_cmd constants to sk_shutdown value range */
1233         sk->sk_shutdown |= how + 1;
1234
1235 out:
1236         release_sock(sk);
1237         return rc ? rc : rc1;
1238 }
1239
1240 static int smc_setsockopt(struct socket *sock, int level, int optname,
1241                           char __user *optval, unsigned int optlen)
1242 {
1243         struct sock *sk = sock->sk;
1244         struct smc_sock *smc;
1245
1246         smc = smc_sk(sk);
1247
1248         /* generic setsockopts reaching us here always apply to the
1249          * CLC socket
1250          */
1251         return smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
1252                                              optval, optlen);
1253 }
1254
1255 static int smc_getsockopt(struct socket *sock, int level, int optname,
1256                           char __user *optval, int __user *optlen)
1257 {
1258         struct smc_sock *smc;
1259
1260         smc = smc_sk(sock->sk);
1261         /* socket options apply to the CLC socket */
1262         return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
1263                                              optval, optlen);
1264 }
1265
1266 static int smc_ioctl(struct socket *sock, unsigned int cmd,
1267                      unsigned long arg)
1268 {
1269         struct smc_sock *smc;
1270
1271         smc = smc_sk(sock->sk);
1272         if (smc->use_fallback)
1273                 return smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
1274         else
1275                 return sock_no_ioctl(sock, cmd, arg);
1276 }
1277
1278 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
1279                             int offset, size_t size, int flags)
1280 {
1281         struct sock *sk = sock->sk;
1282         struct smc_sock *smc;
1283         int rc = -EPIPE;
1284
1285         smc = smc_sk(sk);
1286         lock_sock(sk);
1287         if (sk->sk_state != SMC_ACTIVE)
1288                 goto out;
1289         if (smc->use_fallback)
1290                 rc = kernel_sendpage(smc->clcsock, page, offset,
1291                                      size, flags);
1292         else
1293                 rc = sock_no_sendpage(sock, page, offset, size, flags);
1294
1295 out:
1296         release_sock(sk);
1297         return rc;
1298 }
1299
1300 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
1301                                struct pipe_inode_info *pipe, size_t len,
1302                                     unsigned int flags)
1303 {
1304         struct sock *sk = sock->sk;
1305         struct smc_sock *smc;
1306         int rc = -ENOTCONN;
1307
1308         smc = smc_sk(sk);
1309         lock_sock(sk);
1310         if ((sk->sk_state != SMC_ACTIVE) && (sk->sk_state != SMC_CLOSED))
1311                 goto out;
1312         if (smc->use_fallback) {
1313                 rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
1314                                                     pipe, len, flags);
1315         } else {
1316                 rc = -EOPNOTSUPP;
1317         }
1318 out:
1319         release_sock(sk);
1320         return rc;
1321 }
1322
1323 /* must look like tcp */
1324 static const struct proto_ops smc_sock_ops = {
1325         .family         = PF_SMC,
1326         .owner          = THIS_MODULE,
1327         .release        = smc_release,
1328         .bind           = smc_bind,
1329         .connect        = smc_connect,
1330         .socketpair     = sock_no_socketpair,
1331         .accept         = smc_accept,
1332         .getname        = smc_getname,
1333         .poll           = smc_poll,
1334         .ioctl          = smc_ioctl,
1335         .listen         = smc_listen,
1336         .shutdown       = smc_shutdown,
1337         .setsockopt     = smc_setsockopt,
1338         .getsockopt     = smc_getsockopt,
1339         .sendmsg        = smc_sendmsg,
1340         .recvmsg        = smc_recvmsg,
1341         .mmap           = sock_no_mmap,
1342         .sendpage       = smc_sendpage,
1343         .splice_read    = smc_splice_read,
1344 };
1345
1346 static int smc_create(struct net *net, struct socket *sock, int protocol,
1347                       int kern)
1348 {
1349         struct smc_sock *smc;
1350         struct sock *sk;
1351         int rc;
1352
1353         rc = -ESOCKTNOSUPPORT;
1354         if (sock->type != SOCK_STREAM)
1355                 goto out;
1356
1357         rc = -EPROTONOSUPPORT;
1358         if ((protocol != IPPROTO_IP) && (protocol != IPPROTO_TCP))
1359                 goto out;
1360
1361         rc = -ENOBUFS;
1362         sock->ops = &smc_sock_ops;
1363         sk = smc_sock_alloc(net, sock);
1364         if (!sk)
1365                 goto out;
1366
1367         /* create internal TCP socket for CLC handshake and fallback */
1368         smc = smc_sk(sk);
1369         smc->use_fallback = false; /* assume rdma capability first */
1370         rc = sock_create_kern(net, PF_INET, SOCK_STREAM,
1371                               IPPROTO_TCP, &smc->clcsock);
1372         if (rc)
1373                 sk_common_release(sk);
1374         smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
1375         smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
1376
1377 out:
1378         return rc;
1379 }
1380
1381 static const struct net_proto_family smc_sock_family_ops = {
1382         .family = PF_SMC,
1383         .owner  = THIS_MODULE,
1384         .create = smc_create,
1385 };
1386
1387 static int __init smc_init(void)
1388 {
1389         int rc;
1390
1391         rc = smc_pnet_init();
1392         if (rc)
1393                 return rc;
1394
1395         rc = smc_llc_init();
1396         if (rc) {
1397                 pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
1398                 goto out_pnet;
1399         }
1400
1401         rc = smc_cdc_init();
1402         if (rc) {
1403                 pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
1404                 goto out_pnet;
1405         }
1406
1407         rc = proto_register(&smc_proto, 1);
1408         if (rc) {
1409                 pr_err("%s: proto_register fails with %d\n", __func__, rc);
1410                 goto out_pnet;
1411         }
1412
1413         rc = sock_register(&smc_sock_family_ops);
1414         if (rc) {
1415                 pr_err("%s: sock_register fails with %d\n", __func__, rc);
1416                 goto out_proto;
1417         }
1418         INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
1419
1420         rc = smc_ib_register_client();
1421         if (rc) {
1422                 pr_err("%s: ib_register fails with %d\n", __func__, rc);
1423                 goto out_sock;
1424         }
1425
1426         static_branch_enable(&tcp_have_smc);
1427         return 0;
1428
1429 out_sock:
1430         sock_unregister(PF_SMC);
1431 out_proto:
1432         proto_unregister(&smc_proto);
1433 out_pnet:
1434         smc_pnet_exit();
1435         return rc;
1436 }
1437
1438 static void __exit smc_exit(void)
1439 {
1440         struct smc_link_group *lgr, *lg;
1441         LIST_HEAD(lgr_freeing_list);
1442
1443         spin_lock_bh(&smc_lgr_list.lock);
1444         if (!list_empty(&smc_lgr_list.list))
1445                 list_splice_init(&smc_lgr_list.list, &lgr_freeing_list);
1446         spin_unlock_bh(&smc_lgr_list.lock);
1447         list_for_each_entry_safe(lgr, lg, &lgr_freeing_list, list) {
1448                 list_del_init(&lgr->list);
1449                 smc_lgr_free(lgr); /* free link group */
1450         }
1451         static_branch_disable(&tcp_have_smc);
1452         smc_ib_unregister_client();
1453         sock_unregister(PF_SMC);
1454         proto_unregister(&smc_proto);
1455         smc_pnet_exit();
1456 }
1457
1458 module_init(smc_init);
1459 module_exit(smc_exit);
1460
1461 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
1462 MODULE_DESCRIPTION("smc socket address family");
1463 MODULE_LICENSE("GPL");
1464 MODULE_ALIAS_NETPROTO(PF_SMC);