net/tipc/server.c

   1 /*
   2  * net/tipc/server.c: TIPC server infrastructure
   3  *
   4  * Copyright (c) 2012-2013, Wind River Systems
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the names of the copyright holders nor the names of its
  16  *    contributors may be used to endorse or promote products derived from
  17  *    this software without specific prior written permission.
  18  *
  19  * Alternatively, this software may be distributed under the terms of the
  20  * GNU General Public License ("GPL") version 2 as published by the Free
  21  * Software Foundation.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  24  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  27  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  28  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  29  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  30  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  31  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  32  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  33  * POSSIBILITY OF SUCH DAMAGE.
  34  */
  35
  36 #include "server.h"
  37 #include "core.h"
  38 #include "socket.h"
  39 #include "addr.h"
  40 #include "msg.h"
  41 #include <net/sock.h>
  42 #include <linux/module.h>
  43
  44 /* Number of messages to send before rescheduling */
  45 #define MAX_SEND_MSG_COUNT      25
  46 #define MAX_RECV_MSG_COUNT      25
  47 #define CF_CONNECTED            1
  48 #define CF_SERVER               2
  49
  50 #define sock2con(x) ((struct tipc_conn *)(x)->sk_user_data)
  51
  52 /**
  53  * struct tipc_conn - TIPC connection structure
  54  * @kref: reference counter to connection object
  55  * @conid: connection identifier
  56  * @sock: socket handler associated with connection
  57  * @flags: indicates connection state
  58  * @server: pointer to connected server
  59  * @rwork: receive work item
  60  * @usr_data: user-specified field
  61  * @rx_action: what to do when connection socket is active
  62  * @outqueue: pointer to first outbound message in queue
  63  * @outqueue_lock: control access to the outqueue
  64  * @outqueue: list of connection objects for its server
  65  * @swork: send work item
  66  */
  67 struct tipc_conn {
  68         struct kref kref;
  69         int conid;
  70         struct socket *sock;
  71         unsigned long flags;
  72         struct tipc_server *server;
  73         struct work_struct rwork;
  74         int (*rx_action) (struct tipc_conn *con);
  75         void *usr_data;
  76         struct list_head outqueue;
  77         spinlock_t outqueue_lock;
  78         struct work_struct swork;
  79 };
  80
  81 /* An entry waiting to be sent */
  82 struct outqueue_entry {
  83         struct list_head list;
  84         struct kvec iov;
  85         struct sockaddr_tipc dest;
  86 };
  87
  88 static void tipc_recv_work(struct work_struct *work);
  89 static void tipc_send_work(struct work_struct *work);
  90 static void tipc_clean_outqueues(struct tipc_conn *con);
  91
  92 static void tipc_conn_kref_release(struct kref *kref)
  93 {
  94         struct tipc_conn *con = container_of(kref, struct tipc_conn, kref);
  95         struct tipc_server *s = con->server;
  96         struct sockaddr_tipc *saddr = s->saddr;
  97         struct socket *sock = con->sock;
  98         struct sock *sk;
  99
 100         if (sock) {
 101                 sk = sock->sk;
 102                 if (test_bit(CF_SERVER, &con->flags)) {
 103                         __module_get(sock->ops->owner);
 104                         __module_get(sk->sk_prot_creator->owner);
 105                 }
 106                 saddr->scope = -TIPC_NODE_SCOPE;
 107                 kernel_bind(sock, (struct sockaddr *)saddr, sizeof(*saddr));
 108                 sock_release(sock);
 109                 con->sock = NULL;
 110         }
 111         spin_lock_bh(&s->idr_lock);
 112         idr_remove(&s->conn_idr, con->conid);
 113         s->idr_in_use--;
 114         spin_unlock_bh(&s->idr_lock);
 115         tipc_clean_outqueues(con);
 116         kfree(con);
 117 }
 118
 119 static void conn_put(struct tipc_conn *con)
 120 {
 121         kref_put(&con->kref, tipc_conn_kref_release);
 122 }
 123
 124 static void conn_get(struct tipc_conn *con)
 125 {
 126         kref_get(&con->kref);
 127 }
 128
 129 static struct tipc_conn *tipc_conn_lookup(struct tipc_server *s, int conid)
 130 {
 131         struct tipc_conn *con;
 132
 133         spin_lock_bh(&s->idr_lock);
 134         con = idr_find(&s->conn_idr, conid);
 135         if (con && test_bit(CF_CONNECTED, &con->flags))
 136                 conn_get(con);
 137         else
 138                 con = NULL;
 139         spin_unlock_bh(&s->idr_lock);
 140         return con;
 141 }
 142
 143 static void sock_data_ready(struct sock *sk)
 144 {
 145         struct tipc_conn *con;
 146
 147         read_lock_bh(&sk->sk_callback_lock);
 148         con = sock2con(sk);
 149         if (con && test_bit(CF_CONNECTED, &con->flags)) {
 150                 conn_get(con);
 151                 if (!queue_work(con->server->rcv_wq, &con->rwork))
 152                         conn_put(con);
 153         }
 154         read_unlock_bh(&sk->sk_callback_lock);
 155 }
 156
 157 static void sock_write_space(struct sock *sk)
 158 {
 159         struct tipc_conn *con;
 160
 161         read_lock_bh(&sk->sk_callback_lock);
 162         con = sock2con(sk);
 163         if (con && test_bit(CF_CONNECTED, &con->flags)) {
 164                 conn_get(con);
 165                 if (!queue_work(con->server->send_wq, &con->swork))
 166                         conn_put(con);
 167         }
 168         read_unlock_bh(&sk->sk_callback_lock);
 169 }
 170
 171 static void tipc_register_callbacks(struct socket *sock, struct tipc_conn *con)
 172 {
 173         struct sock *sk = sock->sk;
 174
 175         write_lock_bh(&sk->sk_callback_lock);
 176
 177         sk->sk_data_ready = sock_data_ready;
 178         sk->sk_write_space = sock_write_space;
 179         sk->sk_user_data = con;
 180
 181         con->sock = sock;
 182
 183         write_unlock_bh(&sk->sk_callback_lock);
 184 }
 185
 186 static void tipc_unregister_callbacks(struct tipc_conn *con)
 187 {
 188         struct sock *sk = con->sock->sk;
 189
 190         write_lock_bh(&sk->sk_callback_lock);
 191         sk->sk_user_data = NULL;
 192         write_unlock_bh(&sk->sk_callback_lock);
 193 }
 194
 195 static void tipc_close_conn(struct tipc_conn *con)
 196 {
 197         struct tipc_server *s = con->server;
 198
 199         if (test_and_clear_bit(CF_CONNECTED, &con->flags)) {
 200                 if (con->sock)
 201                         tipc_unregister_callbacks(con);
 202
 203                 if (con->conid)
 204                         s->tipc_conn_release(con->conid, con->usr_data);
 205
 206                 /* We shouldn't flush pending works as we may be in the
 207                  * thread. In fact the races with pending rx/tx work structs
 208                  * are harmless for us here as we have already deleted this
 209                  * connection from server connection list.
 210                  */
 211                 if (con->sock)
 212                         kernel_sock_shutdown(con->sock, SHUT_RDWR);
 213                 conn_put(con);
 214         }
 215 }
 216
 217 static struct tipc_conn *tipc_alloc_conn(struct tipc_server *s)
 218 {
 219         struct tipc_conn *con;
 220         int ret;
 221
 222         con = kzalloc(sizeof(struct tipc_conn), GFP_ATOMIC);
 223         if (!con)
 224                 return ERR_PTR(-ENOMEM);
 225
 226         kref_init(&con->kref);
 227         INIT_LIST_HEAD(&con->outqueue);
 228         spin_lock_init(&con->outqueue_lock);
 229         INIT_WORK(&con->swork, tipc_send_work);
 230         INIT_WORK(&con->rwork, tipc_recv_work);
 231
 232         spin_lock_bh(&s->idr_lock);
 233         ret = idr_alloc(&s->conn_idr, con, 0, 0, GFP_ATOMIC);
 234         if (ret < 0) {
 235                 kfree(con);
 236                 spin_unlock_bh(&s->idr_lock);
 237                 return ERR_PTR(-ENOMEM);
 238         }
 239         con->conid = ret;
 240         s->idr_in_use++;
 241         spin_unlock_bh(&s->idr_lock);
 242
 243         set_bit(CF_CONNECTED, &con->flags);
 244         con->server = s;
 245
 246         return con;
 247 }
 248
 249 static int tipc_receive_from_sock(struct tipc_conn *con)
 250 {
 251         struct msghdr msg = {};
 252         struct tipc_server *s = con->server;
 253         struct sockaddr_tipc addr;
 254         struct kvec iov;
 255         void *buf;
 256         int ret;
 257
 258         buf = kmem_cache_alloc(s->rcvbuf_cache, GFP_ATOMIC);
 259         if (!buf) {
 260                 ret = -ENOMEM;
 261                 goto out_close;
 262         }
 263
 264         iov.iov_base = buf;
 265         iov.iov_len = s->max_rcvbuf_size;
 266         msg.msg_name = &addr;
 267         ret = kernel_recvmsg(con->sock, &msg, &iov, 1, iov.iov_len,
 268                              MSG_DONTWAIT);
 269         if (ret <= 0) {
 270                 kmem_cache_free(s->rcvbuf_cache, buf);
 271                 goto out_close;
 272         }
 273
 274         s->tipc_conn_recvmsg(sock_net(con->sock->sk), con->conid, &addr,
 275                              con->usr_data, buf, ret);
 276
 277         kmem_cache_free(s->rcvbuf_cache, buf);
 278
 279         return 0;
 280
 281 out_close:
 282         if (ret != -EWOULDBLOCK)
 283                 tipc_close_conn(con);
 284         else if (ret == 0)
 285                 /* Don't return success if we really got EOF */
 286                 ret = -EAGAIN;
 287
 288         return ret;
 289 }
 290
 291 static int tipc_accept_from_sock(struct tipc_conn *con)
 292 {
 293         struct tipc_server *s = con->server;
 294         struct socket *sock = con->sock;
 295         struct socket *newsock;
 296         struct tipc_conn *newcon;
 297         int ret;
 298
 299         ret = kernel_accept(sock, &newsock, O_NONBLOCK);
 300         if (ret < 0)
 301                 return ret;
 302
 303         newcon = tipc_alloc_conn(con->server);
 304         if (IS_ERR(newcon)) {
 305                 ret = PTR_ERR(newcon);
 306                 sock_release(newsock);
 307                 return ret;
 308         }
 309
 310         newcon->rx_action = tipc_receive_from_sock;
 311         tipc_register_callbacks(newsock, newcon);
 312
 313         /* Notify that new connection is incoming */
 314         newcon->usr_data = s->tipc_conn_new(newcon->conid);
 315         if (!newcon->usr_data) {
 316                 sock_release(newsock);
 317                 conn_put(newcon);
 318                 return -ENOMEM;
 319         }
 320
 321         /* Wake up receive process in case of 'SYN+' message */
 322         newsock->sk->sk_data_ready(newsock->sk);
 323         return ret;
 324 }
 325
 326 static struct socket *tipc_create_listen_sock(struct tipc_conn *con)
 327 {
 328         struct tipc_server *s = con->server;
 329         struct socket *sock = NULL;
 330         int ret;
 331
 332         ret = sock_create_kern(s->net, AF_TIPC, SOCK_SEQPACKET, 0, &sock);
 333         if (ret < 0)
 334                 return NULL;
 335         ret = kernel_setsockopt(sock, SOL_TIPC, TIPC_IMPORTANCE,
 336                                 (char *)&s->imp, sizeof(s->imp));
 337         if (ret < 0)
 338                 goto create_err;
 339         ret = kernel_bind(sock, (struct sockaddr *)s->saddr, sizeof(*s->saddr));
 340         if (ret < 0)
 341                 goto create_err;
 342
 343         switch (s->type) {
 344         case SOCK_STREAM:
 345         case SOCK_SEQPACKET:
 346                 con->rx_action = tipc_accept_from_sock;
 347
 348                 ret = kernel_listen(sock, 0);
 349                 if (ret < 0)
 350                         goto create_err;
 351                 break;
 352         case SOCK_DGRAM:
 353         case SOCK_RDM:
 354                 con->rx_action = tipc_receive_from_sock;
 355                 break;
 356         default:
 357                 pr_err("Unknown socket type %d\n", s->type);
 358                 goto create_err;
 359         }
 360
 361         /* As server's listening socket owner and creator is the same module,
 362          * we have to decrease TIPC module reference count to guarantee that
 363          * it remains zero after the server socket is created, otherwise,
 364          * executing "rmmod" command is unable to make TIPC module deleted
 365          * after TIPC module is inserted successfully.
 366          *
 367          * However, the reference count is ever increased twice in
 368          * sock_create_kern(): one is to increase the reference count of owner
 369          * of TIPC socket's proto_ops struct; another is to increment the
 370          * reference count of owner of TIPC proto struct. Therefore, we must
 371          * decrement the module reference count twice to ensure that it keeps
 372          * zero after server's listening socket is created. Of course, we
 373          * must bump the module reference count twice as well before the socket
 374          * is closed.
 375          */
 376         module_put(sock->ops->owner);
 377         module_put(sock->sk->sk_prot_creator->owner);
 378         set_bit(CF_SERVER, &con->flags);
 379
 380         return sock;
 381
 382 create_err:
 383         kernel_sock_shutdown(sock, SHUT_RDWR);
 384         sock_release(sock);
 385         return NULL;
 386 }
 387
 388 static int tipc_open_listening_sock(struct tipc_server *s)
 389 {
 390         struct socket *sock;
 391         struct tipc_conn *con;
 392
 393         con = tipc_alloc_conn(s);
 394         if (IS_ERR(con))
 395                 return PTR_ERR(con);
 396
 397         sock = tipc_create_listen_sock(con);
 398         if (!sock) {
 399                 idr_remove(&s->conn_idr, con->conid);
 400                 s->idr_in_use--;
 401                 kfree(con);
 402                 return -EINVAL;
 403         }
 404
 405         tipc_register_callbacks(sock, con);
 406         return 0;
 407 }
 408
 409 static struct outqueue_entry *tipc_alloc_entry(void *data, int len)
 410 {
 411         struct outqueue_entry *entry;
 412         void *buf;
 413
 414         entry = kmalloc(sizeof(struct outqueue_entry), GFP_ATOMIC);
 415         if (!entry)
 416                 return NULL;
 417
 418         buf = kmemdup(data, len, GFP_ATOMIC);
 419         if (!buf) {
 420                 kfree(entry);
 421                 return NULL;
 422         }
 423
 424         entry->iov.iov_base = buf;
 425         entry->iov.iov_len = len;
 426
 427         return entry;
 428 }
 429
 430 static void tipc_free_entry(struct outqueue_entry *e)
 431 {
 432         kfree(e->iov.iov_base);
 433         kfree(e);
 434 }
 435
 436 static void tipc_clean_outqueues(struct tipc_conn *con)
 437 {
 438         struct outqueue_entry *e, *safe;
 439
 440         spin_lock_bh(&con->outqueue_lock);
 441         list_for_each_entry_safe(e, safe, &con->outqueue, list) {
 442                 list_del(&e->list);
 443                 tipc_free_entry(e);
 444         }
 445         spin_unlock_bh(&con->outqueue_lock);
 446 }
 447
 448 int tipc_conn_sendmsg(struct tipc_server *s, int conid,
 449                       struct sockaddr_tipc *addr, void *data, size_t len)
 450 {
 451         struct outqueue_entry *e;
 452         struct tipc_conn *con;
 453
 454         con = tipc_conn_lookup(s, conid);
 455         if (!con)
 456                 return -EINVAL;
 457
 458         if (!test_bit(CF_CONNECTED, &con->flags)) {
 459                 conn_put(con);
 460                 return 0;
 461         }
 462
 463         e = tipc_alloc_entry(data, len);
 464         if (!e) {
 465                 conn_put(con);
 466                 return -ENOMEM;
 467         }
 468
 469         if (addr)
 470                 memcpy(&e->dest, addr, sizeof(struct sockaddr_tipc));
 471
 472         spin_lock_bh(&con->outqueue_lock);
 473         list_add_tail(&e->list, &con->outqueue);
 474         spin_unlock_bh(&con->outqueue_lock);
 475
 476         if (!queue_work(s->send_wq, &con->swork))
 477                 conn_put(con);
 478         return 0;
 479 }
 480
 481 void tipc_conn_terminate(struct tipc_server *s, int conid)
 482 {
 483         struct tipc_conn *con;
 484
 485         con = tipc_conn_lookup(s, conid);
 486         if (con) {
 487                 tipc_close_conn(con);
 488                 conn_put(con);
 489         }
 490 }
 491
 492 bool tipc_topsrv_kern_subscr(struct net *net, u32 port, u32 type,
 493                              u32 lower, u32 upper, int *conid)
 494 {
 495         struct tipc_subscriber *scbr;
 496         struct tipc_subscr sub;
 497         struct tipc_server *s;
 498         struct tipc_conn *con;
 499
 500         sub.seq.type = type;
 501         sub.seq.lower = lower;
 502         sub.seq.upper = upper;
 503         sub.timeout = TIPC_WAIT_FOREVER;
 504         sub.filter = TIPC_SUB_PORTS;
 505         *(u32 *)&sub.usr_handle = port;
 506
 507         con = tipc_alloc_conn(tipc_topsrv(net));
 508         if (IS_ERR(con))
 509                 return false;
 510
 511         *conid = con->conid;
 512         s = con->server;
 513         scbr = s->tipc_conn_new(*conid);
 514         if (!scbr) {
 515                 conn_put(con);
 516                 return false;
 517         }
 518
 519         con->usr_data = scbr;
 520         con->sock = NULL;
 521         s->tipc_conn_recvmsg(net, *conid, NULL, scbr, &sub, sizeof(sub));
 522         return true;
 523 }
 524
 525 void tipc_topsrv_kern_unsubscr(struct net *net, int conid)
 526 {
 527         struct tipc_conn *con;
 528
 529         con = tipc_conn_lookup(tipc_topsrv(net), conid);
 530         if (!con)
 531                 return;
 532         tipc_close_conn(con);
 533         conn_put(con);
 534 }
 535
 536 static void tipc_send_kern_top_evt(struct net *net, struct tipc_event *evt)
 537 {
 538         u32 port = *(u32 *)&evt->s.usr_handle;
 539         u32 self = tipc_own_addr(net);
 540         struct sk_buff_head evtq;
 541         struct sk_buff *skb;
 542
 543         skb = tipc_msg_create(TOP_SRV, 0, INT_H_SIZE, sizeof(*evt),
 544                               self, self, port, port, 0);
 545         if (!skb)
 546                 return;
 547         msg_set_dest_droppable(buf_msg(skb), true);
 548         memcpy(msg_data(buf_msg(skb)), evt, sizeof(*evt));
 549         skb_queue_head_init(&evtq);
 550         __skb_queue_tail(&evtq, skb);
 551         tipc_sk_rcv(net, &evtq);
 552 }
 553
 554 static void tipc_send_to_sock(struct tipc_conn *con)
 555 {
 556         struct tipc_server *s = con->server;
 557         struct outqueue_entry *e;
 558         struct tipc_event *evt;
 559         struct msghdr msg;
 560         int count = 0;
 561         int ret;
 562
 563         spin_lock_bh(&con->outqueue_lock);
 564         while (test_bit(CF_CONNECTED, &con->flags)) {
 565                 e = list_entry(con->outqueue.next, struct outqueue_entry, list);
 566                 if ((struct list_head *) e == &con->outqueue)
 567                         break;
 568
 569                 spin_unlock_bh(&con->outqueue_lock);
 570
 571                 if (con->sock) {
 572                         memset(&msg, 0, sizeof(msg));
 573                         msg.msg_flags = MSG_DONTWAIT;
 574                         if (s->type == SOCK_DGRAM || s->type == SOCK_RDM) {
 575                                 msg.msg_name = &e->dest;
 576                                 msg.msg_namelen = sizeof(struct sockaddr_tipc);
 577                         }
 578                         ret = kernel_sendmsg(con->sock, &msg, &e->iov, 1,
 579                                              e->iov.iov_len);
 580                         if (ret == -EWOULDBLOCK || ret == 0) {
 581                                 cond_resched();
 582                                 goto out;
 583                         } else if (ret < 0) {
 584                                 goto send_err;
 585                         }
 586                 } else {
 587                         evt = e->iov.iov_base;
 588                         tipc_send_kern_top_evt(s->net, evt);
 589                 }
 590                 /* Don't starve users filling buffers */
 591                 if (++count >= MAX_SEND_MSG_COUNT) {
 592                         cond_resched();
 593                         count = 0;
 594                 }
 595
 596                 spin_lock_bh(&con->outqueue_lock);
 597                 list_del(&e->list);
 598                 tipc_free_entry(e);
 599         }
 600         spin_unlock_bh(&con->outqueue_lock);
 601 out:
 602         return;
 603
 604 send_err:
 605         tipc_close_conn(con);
 606 }
 607
 608 static void tipc_recv_work(struct work_struct *work)
 609 {
 610         struct tipc_conn *con = container_of(work, struct tipc_conn, rwork);
 611         int count = 0;
 612
 613         while (test_bit(CF_CONNECTED, &con->flags)) {
 614                 if (con->rx_action(con))
 615                         break;
 616
 617                 /* Don't flood Rx machine */
 618                 if (++count >= MAX_RECV_MSG_COUNT) {
 619                         cond_resched();
 620                         count = 0;
 621                 }
 622         }
 623         conn_put(con);
 624 }
 625
 626 static void tipc_send_work(struct work_struct *work)
 627 {
 628         struct tipc_conn *con = container_of(work, struct tipc_conn, swork);
 629
 630         if (test_bit(CF_CONNECTED, &con->flags))
 631                 tipc_send_to_sock(con);
 632
 633         conn_put(con);
 634 }
 635
 636 static void tipc_work_stop(struct tipc_server *s)
 637 {
 638         destroy_workqueue(s->rcv_wq);
 639         destroy_workqueue(s->send_wq);
 640 }
 641
 642 static int tipc_work_start(struct tipc_server *s)
 643 {
 644         s->rcv_wq = alloc_ordered_workqueue("tipc_rcv", 0);
 645         if (!s->rcv_wq) {
 646                 pr_err("can't start tipc receive workqueue\n");
 647                 return -ENOMEM;
 648         }
 649
 650         s->send_wq = alloc_ordered_workqueue("tipc_send", 0);
 651         if (!s->send_wq) {
 652                 pr_err("can't start tipc send workqueue\n");
 653                 destroy_workqueue(s->rcv_wq);
 654                 return -ENOMEM;
 655         }
 656
 657         return 0;
 658 }
 659
 660 int tipc_server_start(struct tipc_server *s)
 661 {
 662         int ret;
 663
 664         spin_lock_init(&s->idr_lock);
 665         idr_init(&s->conn_idr);
 666         s->idr_in_use = 0;
 667
 668         s->rcvbuf_cache = kmem_cache_create(s->name, s->max_rcvbuf_size,
 669                                             0, SLAB_HWCACHE_ALIGN, NULL);
 670         if (!s->rcvbuf_cache)
 671                 return -ENOMEM;
 672
 673         ret = tipc_work_start(s);
 674         if (ret < 0) {
 675                 kmem_cache_destroy(s->rcvbuf_cache);
 676                 return ret;
 677         }
 678         ret = tipc_open_listening_sock(s);
 679         if (ret < 0) {
 680                 tipc_work_stop(s);
 681                 kmem_cache_destroy(s->rcvbuf_cache);
 682                 return ret;
 683         }
 684         return ret;
 685 }
 686
 687 void tipc_server_stop(struct tipc_server *s)
 688 {
 689         struct tipc_conn *con;
 690         int id;
 691
 692         spin_lock_bh(&s->idr_lock);
 693         for (id = 0; s->idr_in_use; id++) {
 694                 con = idr_find(&s->conn_idr, id);
 695                 if (con) {
 696                         spin_unlock_bh(&s->idr_lock);
 697                         tipc_close_conn(con);
 698                         spin_lock_bh(&s->idr_lock);
 699                 }
 700         }
 701         spin_unlock_bh(&s->idr_lock);
 702
 703         tipc_work_stop(s);
 704         kmem_cache_destroy(s->rcvbuf_cache);
 705         idr_destroy(&s->conn_idr);
 706 }