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) {
 136                 if (!test_bit(CF_CONNECTED, &con->flags) ||
 137                     !kref_get_unless_zero(&con->kref))
 138                         con = NULL;
 139         }
 140         spin_unlock_bh(&s->idr_lock);
 141         return con;
 142 }
 143
 144 static void sock_data_ready(struct sock *sk)
 145 {
 146         struct tipc_conn *con;
 147
 148         read_lock_bh(&sk->sk_callback_lock);
 149         con = sock2con(sk);
 150         if (con && test_bit(CF_CONNECTED, &con->flags)) {
 151                 conn_get(con);
 152                 if (!queue_work(con->server->rcv_wq, &con->rwork))
 153                         conn_put(con);
 154         }
 155         read_unlock_bh(&sk->sk_callback_lock);
 156 }
 157
 158 static void sock_write_space(struct sock *sk)
 159 {
 160         struct tipc_conn *con;
 161
 162         read_lock_bh(&sk->sk_callback_lock);
 163         con = sock2con(sk);
 164         if (con && test_bit(CF_CONNECTED, &con->flags)) {
 165                 conn_get(con);
 166                 if (!queue_work(con->server->send_wq, &con->swork))
 167                         conn_put(con);
 168         }
 169         read_unlock_bh(&sk->sk_callback_lock);
 170 }
 171
 172 static void tipc_register_callbacks(struct socket *sock, struct tipc_conn *con)
 173 {
 174         struct sock *sk = sock->sk;
 175
 176         write_lock_bh(&sk->sk_callback_lock);
 177
 178         sk->sk_data_ready = sock_data_ready;
 179         sk->sk_write_space = sock_write_space;
 180         sk->sk_user_data = con;
 181
 182         con->sock = sock;
 183
 184         write_unlock_bh(&sk->sk_callback_lock);
 185 }
 186
 187 static void tipc_close_conn(struct tipc_conn *con)
 188 {
 189         struct tipc_server *s = con->server;
 190         struct sock *sk = con->sock->sk;
 191         bool disconnect = false;
 192
 193         write_lock_bh(&sk->sk_callback_lock);
 194         disconnect = test_and_clear_bit(CF_CONNECTED, &con->flags);
 195         if (disconnect) {
 196                 sk->sk_user_data = NULL;
 197                 if (con->conid)
 198                         s->tipc_conn_release(con->conid, con->usr_data);
 199         }
 200         write_unlock_bh(&sk->sk_callback_lock);
 201
 202         /* Handle concurrent calls from sending and receiving threads */
 203         if (!disconnect)
 204                 return;
 205
 206         /* Don't flush pending works, -just let them expire */
 207         kernel_sock_shutdown(con->sock, SHUT_RDWR);
 208         conn_put(con);
 209 }
 210
 211 static struct tipc_conn *tipc_alloc_conn(struct tipc_server *s)
 212 {
 213         struct tipc_conn *con;
 214         int ret;
 215
 216         con = kzalloc(sizeof(struct tipc_conn), GFP_ATOMIC);
 217         if (!con)
 218                 return ERR_PTR(-ENOMEM);
 219
 220         kref_init(&con->kref);
 221         INIT_LIST_HEAD(&con->outqueue);
 222         spin_lock_init(&con->outqueue_lock);
 223         INIT_WORK(&con->swork, tipc_send_work);
 224         INIT_WORK(&con->rwork, tipc_recv_work);
 225
 226         spin_lock_bh(&s->idr_lock);
 227         ret = idr_alloc(&s->conn_idr, con, 0, 0, GFP_ATOMIC);
 228         if (ret < 0) {
 229                 kfree(con);
 230                 spin_unlock_bh(&s->idr_lock);
 231                 return ERR_PTR(-ENOMEM);
 232         }
 233         con->conid = ret;
 234         s->idr_in_use++;
 235         spin_unlock_bh(&s->idr_lock);
 236
 237         set_bit(CF_CONNECTED, &con->flags);
 238         con->server = s;
 239
 240         return con;
 241 }
 242
 243 static int tipc_receive_from_sock(struct tipc_conn *con)
 244 {
 245         struct tipc_server *s = con->server;
 246         struct sock *sk = con->sock->sk;
 247         struct sockaddr_tipc addr;
 248         struct msghdr msg = {};
 249         struct kvec iov;
 250         void *buf;
 251         int ret;
 252
 253         buf = kmem_cache_alloc(s->rcvbuf_cache, GFP_ATOMIC);
 254         if (!buf) {
 255                 ret = -ENOMEM;
 256                 goto out_close;
 257         }
 258
 259         iov.iov_base = buf;
 260         iov.iov_len = s->max_rcvbuf_size;
 261         msg.msg_name = &addr;
 262         iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1, iov.iov_len);
 263         ret = sock_recvmsg(con->sock, &msg, MSG_DONTWAIT);
 264         if (ret <= 0) {
 265                 kmem_cache_free(s->rcvbuf_cache, buf);
 266                 goto out_close;
 267         }
 268
 269         read_lock_bh(&sk->sk_callback_lock);
 270         if (test_bit(CF_CONNECTED, &con->flags))
 271                 ret = s->tipc_conn_recvmsg(sock_net(con->sock->sk), con->conid,
 272                                            &addr, con->usr_data, buf, ret);
 273         read_unlock_bh(&sk->sk_callback_lock);
 274         kmem_cache_free(s->rcvbuf_cache, buf);
 275         if (ret < 0)
 276                 tipc_conn_terminate(s, con->conid);
 277         return ret;
 278
 279 out_close:
 280         if (ret != -EWOULDBLOCK)
 281                 tipc_close_conn(con);
 282         else if (ret == 0)
 283                 /* Don't return success if we really got EOF */
 284                 ret = -EAGAIN;
 285
 286         return ret;
 287 }
 288
 289 static int tipc_accept_from_sock(struct tipc_conn *con)
 290 {
 291         struct tipc_server *s = con->server;
 292         struct socket *sock = con->sock;
 293         struct socket *newsock;
 294         struct tipc_conn *newcon;
 295         int ret;
 296
 297         ret = kernel_accept(sock, &newsock, O_NONBLOCK);
 298         if (ret < 0)
 299                 return ret;
 300
 301         newcon = tipc_alloc_conn(con->server);
 302         if (IS_ERR(newcon)) {
 303                 ret = PTR_ERR(newcon);
 304                 sock_release(newsock);
 305                 return ret;
 306         }
 307
 308         newcon->rx_action = tipc_receive_from_sock;
 309         tipc_register_callbacks(newsock, newcon);
 310
 311         /* Notify that new connection is incoming */
 312         newcon->usr_data = s->tipc_conn_new(newcon->conid);
 313         if (!newcon->usr_data) {
 314                 sock_release(newsock);
 315                 conn_put(newcon);
 316                 return -ENOMEM;
 317         }
 318
 319         /* Wake up receive process in case of 'SYN+' message */
 320         newsock->sk->sk_data_ready(newsock->sk);
 321         return ret;
 322 }
 323
 324 static struct socket *tipc_create_listen_sock(struct tipc_conn *con)
 325 {
 326         struct tipc_server *s = con->server;
 327         struct socket *sock = NULL;
 328         int ret;
 329
 330         ret = sock_create_kern(s->net, AF_TIPC, SOCK_SEQPACKET, 0, &sock);
 331         if (ret < 0)
 332                 return NULL;
 333         ret = kernel_setsockopt(sock, SOL_TIPC, TIPC_IMPORTANCE,
 334                                 (char *)&s->imp, sizeof(s->imp));
 335         if (ret < 0)
 336                 goto create_err;
 337         ret = kernel_bind(sock, (struct sockaddr *)s->saddr, sizeof(*s->saddr));
 338         if (ret < 0)
 339                 goto create_err;
 340
 341         switch (s->type) {
 342         case SOCK_STREAM:
 343         case SOCK_SEQPACKET:
 344                 con->rx_action = tipc_accept_from_sock;
 345
 346                 ret = kernel_listen(sock, 0);
 347                 if (ret < 0)
 348                         goto create_err;
 349                 break;
 350         case SOCK_DGRAM:
 351         case SOCK_RDM:
 352                 con->rx_action = tipc_receive_from_sock;
 353                 break;
 354         default:
 355                 pr_err("Unknown socket type %d\n", s->type);
 356                 goto create_err;
 357         }
 358
 359         /* As server's listening socket owner and creator is the same module,
 360          * we have to decrease TIPC module reference count to guarantee that
 361          * it remains zero after the server socket is created, otherwise,
 362          * executing "rmmod" command is unable to make TIPC module deleted
 363          * after TIPC module is inserted successfully.
 364          *
 365          * However, the reference count is ever increased twice in
 366          * sock_create_kern(): one is to increase the reference count of owner
 367          * of TIPC socket's proto_ops struct; another is to increment the
 368          * reference count of owner of TIPC proto struct. Therefore, we must
 369          * decrement the module reference count twice to ensure that it keeps
 370          * zero after server's listening socket is created. Of course, we
 371          * must bump the module reference count twice as well before the socket
 372          * is closed.
 373          */
 374         module_put(sock->ops->owner);
 375         module_put(sock->sk->sk_prot_creator->owner);
 376         set_bit(CF_SERVER, &con->flags);
 377
 378         return sock;
 379
 380 create_err:
 381         kernel_sock_shutdown(sock, SHUT_RDWR);
 382         sock_release(sock);
 383         return NULL;
 384 }
 385
 386 static int tipc_open_listening_sock(struct tipc_server *s)
 387 {
 388         struct socket *sock;
 389         struct tipc_conn *con;
 390
 391         con = tipc_alloc_conn(s);
 392         if (IS_ERR(con))
 393                 return PTR_ERR(con);
 394
 395         sock = tipc_create_listen_sock(con);
 396         if (!sock) {
 397                 idr_remove(&s->conn_idr, con->conid);
 398                 s->idr_in_use--;
 399                 kfree(con);
 400                 return -EINVAL;
 401         }
 402
 403         tipc_register_callbacks(sock, con);
 404         return 0;
 405 }
 406
 407 static struct outqueue_entry *tipc_alloc_entry(void *data, int len)
 408 {
 409         struct outqueue_entry *entry;
 410         void *buf;
 411
 412         entry = kmalloc(sizeof(struct outqueue_entry), GFP_ATOMIC);
 413         if (!entry)
 414                 return NULL;
 415
 416         buf = kmemdup(data, len, GFP_ATOMIC);
 417         if (!buf) {
 418                 kfree(entry);
 419                 return NULL;
 420         }
 421
 422         entry->iov.iov_base = buf;
 423         entry->iov.iov_len = len;
 424
 425         return entry;
 426 }
 427
 428 static void tipc_free_entry(struct outqueue_entry *e)
 429 {
 430         kfree(e->iov.iov_base);
 431         kfree(e);
 432 }
 433
 434 static void tipc_clean_outqueues(struct tipc_conn *con)
 435 {
 436         struct outqueue_entry *e, *safe;
 437
 438         spin_lock_bh(&con->outqueue_lock);
 439         list_for_each_entry_safe(e, safe, &con->outqueue, list) {
 440                 list_del(&e->list);
 441                 tipc_free_entry(e);
 442         }
 443         spin_unlock_bh(&con->outqueue_lock);
 444 }
 445
 446 int tipc_conn_sendmsg(struct tipc_server *s, int conid,
 447                       struct sockaddr_tipc *addr, void *data, size_t len)
 448 {
 449         struct outqueue_entry *e;
 450         struct tipc_conn *con;
 451
 452         con = tipc_conn_lookup(s, conid);
 453         if (!con)
 454                 return -EINVAL;
 455
 456         if (!test_bit(CF_CONNECTED, &con->flags)) {
 457                 conn_put(con);
 458                 return 0;
 459         }
 460
 461         e = tipc_alloc_entry(data, len);
 462         if (!e) {
 463                 conn_put(con);
 464                 return -ENOMEM;
 465         }
 466
 467         if (addr)
 468                 memcpy(&e->dest, addr, sizeof(struct sockaddr_tipc));
 469
 470         spin_lock_bh(&con->outqueue_lock);
 471         list_add_tail(&e->list, &con->outqueue);
 472         spin_unlock_bh(&con->outqueue_lock);
 473
 474         if (!queue_work(s->send_wq, &con->swork))
 475                 conn_put(con);
 476         return 0;
 477 }
 478
 479 void tipc_conn_terminate(struct tipc_server *s, int conid)
 480 {
 481         struct tipc_conn *con;
 482
 483         con = tipc_conn_lookup(s, conid);
 484         if (con) {
 485                 tipc_close_conn(con);
 486                 conn_put(con);
 487         }
 488 }
 489
 490 bool tipc_topsrv_kern_subscr(struct net *net, u32 port, u32 type, u32 lower,
 491                              u32 upper, u32 filter, int *conid)
 492 {
 493         struct tipc_subscriber *scbr;
 494         struct tipc_subscr sub;
 495         struct tipc_server *s;
 496         struct tipc_conn *con;
 497
 498         sub.seq.type = type;
 499         sub.seq.lower = lower;
 500         sub.seq.upper = upper;
 501         sub.timeout = TIPC_WAIT_FOREVER;
 502         sub.filter = filter;
 503         *(u32 *)&sub.usr_handle = port;
 504
 505         con = tipc_alloc_conn(tipc_topsrv(net));
 506         if (IS_ERR(con))
 507                 return false;
 508
 509         *conid = con->conid;
 510         s = con->server;
 511         scbr = s->tipc_conn_new(*conid);
 512         if (!scbr) {
 513                 conn_put(con);
 514                 return false;
 515         }
 516
 517         con->usr_data = scbr;
 518         con->sock = NULL;
 519         s->tipc_conn_recvmsg(net, *conid, NULL, scbr, &sub, sizeof(sub));
 520         return true;
 521 }
 522
 523 void tipc_topsrv_kern_unsubscr(struct net *net, int conid)
 524 {
 525         struct tipc_conn *con;
 526         struct tipc_server *srv;
 527
 528         con = tipc_conn_lookup(tipc_topsrv(net), conid);
 529         if (!con)
 530                 return;
 531
 532         test_and_clear_bit(CF_CONNECTED, &con->flags);
 533         srv = con->server;
 534         if (con->conid)
 535                 srv->tipc_conn_release(con->conid, con->usr_data);
 536         conn_put(con);
 537         conn_put(con);
 538 }
 539
 540 static void tipc_send_kern_top_evt(struct net *net, struct tipc_event *evt)
 541 {
 542         u32 port = *(u32 *)&evt->s.usr_handle;
 543         u32 self = tipc_own_addr(net);
 544         struct sk_buff_head evtq;
 545         struct sk_buff *skb;
 546
 547         skb = tipc_msg_create(TOP_SRV, 0, INT_H_SIZE, sizeof(*evt),
 548                               self, self, port, port, 0);
 549         if (!skb)
 550                 return;
 551         msg_set_dest_droppable(buf_msg(skb), true);
 552         memcpy(msg_data(buf_msg(skb)), evt, sizeof(*evt));
 553         skb_queue_head_init(&evtq);
 554         __skb_queue_tail(&evtq, skb);
 555         tipc_sk_rcv(net, &evtq);
 556 }
 557
 558 static void tipc_send_to_sock(struct tipc_conn *con)
 559 {
 560         struct tipc_server *s = con->server;
 561         struct outqueue_entry *e;
 562         struct tipc_event *evt;
 563         struct msghdr msg;
 564         int count = 0;
 565         int ret;
 566
 567         spin_lock_bh(&con->outqueue_lock);
 568         while (test_bit(CF_CONNECTED, &con->flags)) {
 569                 e = list_entry(con->outqueue.next, struct outqueue_entry, list);
 570                 if ((struct list_head *) e == &con->outqueue)
 571                         break;
 572
 573                 spin_unlock_bh(&con->outqueue_lock);
 574
 575                 if (con->sock) {
 576                         memset(&msg, 0, sizeof(msg));
 577                         msg.msg_flags = MSG_DONTWAIT;
 578                         if (s->type == SOCK_DGRAM || s->type == SOCK_RDM) {
 579                                 msg.msg_name = &e->dest;
 580                                 msg.msg_namelen = sizeof(struct sockaddr_tipc);
 581                         }
 582                         ret = kernel_sendmsg(con->sock, &msg, &e->iov, 1,
 583                                              e->iov.iov_len);
 584                         if (ret == -EWOULDBLOCK || ret == 0) {
 585                                 cond_resched();
 586                                 goto out;
 587                         } else if (ret < 0) {
 588                                 goto send_err;
 589                         }
 590                 } else {
 591                         evt = e->iov.iov_base;
 592                         tipc_send_kern_top_evt(s->net, evt);
 593                 }
 594                 /* Don't starve users filling buffers */
 595                 if (++count >= MAX_SEND_MSG_COUNT) {
 596                         cond_resched();
 597                         count = 0;
 598                 }
 599
 600                 spin_lock_bh(&con->outqueue_lock);
 601                 list_del(&e->list);
 602                 tipc_free_entry(e);
 603         }
 604         spin_unlock_bh(&con->outqueue_lock);
 605 out:
 606         return;
 607
 608 send_err:
 609         tipc_close_conn(con);
 610 }
 611
 612 static void tipc_recv_work(struct work_struct *work)
 613 {
 614         struct tipc_conn *con = container_of(work, struct tipc_conn, rwork);
 615         int count = 0;
 616
 617         while (test_bit(CF_CONNECTED, &con->flags)) {
 618                 if (con->rx_action(con))
 619                         break;
 620
 621                 /* Don't flood Rx machine */
 622                 if (++count >= MAX_RECV_MSG_COUNT) {
 623                         cond_resched();
 624                         count = 0;
 625                 }
 626         }
 627         conn_put(con);
 628 }
 629
 630 static void tipc_send_work(struct work_struct *work)
 631 {
 632         struct tipc_conn *con = container_of(work, struct tipc_conn, swork);
 633
 634         if (test_bit(CF_CONNECTED, &con->flags))
 635                 tipc_send_to_sock(con);
 636
 637         conn_put(con);
 638 }
 639
 640 static void tipc_work_stop(struct tipc_server *s)
 641 {
 642         destroy_workqueue(s->rcv_wq);
 643         destroy_workqueue(s->send_wq);
 644 }
 645
 646 static int tipc_work_start(struct tipc_server *s)
 647 {
 648         s->rcv_wq = alloc_ordered_workqueue("tipc_rcv", 0);
 649         if (!s->rcv_wq) {
 650                 pr_err("can't start tipc receive workqueue\n");
 651                 return -ENOMEM;
 652         }
 653
 654         s->send_wq = alloc_ordered_workqueue("tipc_send", 0);
 655         if (!s->send_wq) {
 656                 pr_err("can't start tipc send workqueue\n");
 657                 destroy_workqueue(s->rcv_wq);
 658                 return -ENOMEM;
 659         }
 660
 661         return 0;
 662 }
 663
 664 int tipc_server_start(struct tipc_server *s)
 665 {
 666         int ret;
 667
 668         spin_lock_init(&s->idr_lock);
 669         idr_init(&s->conn_idr);
 670         s->idr_in_use = 0;
 671
 672         s->rcvbuf_cache = kmem_cache_create(s->name, s->max_rcvbuf_size,
 673                                             0, SLAB_HWCACHE_ALIGN, NULL);
 674         if (!s->rcvbuf_cache)
 675                 return -ENOMEM;
 676
 677         ret = tipc_work_start(s);
 678         if (ret < 0) {
 679                 kmem_cache_destroy(s->rcvbuf_cache);
 680                 return ret;
 681         }
 682         ret = tipc_open_listening_sock(s);
 683         if (ret < 0) {
 684                 tipc_work_stop(s);
 685                 kmem_cache_destroy(s->rcvbuf_cache);
 686                 return ret;
 687         }
 688         return ret;
 689 }
 690
 691 void tipc_server_stop(struct tipc_server *s)
 692 {
 693         struct tipc_conn *con;
 694         int id;
 695
 696         spin_lock_bh(&s->idr_lock);
 697         for (id = 0; s->idr_in_use; id++) {
 698                 con = idr_find(&s->conn_idr, id);
 699                 if (con) {
 700                         spin_unlock_bh(&s->idr_lock);
 701                         tipc_close_conn(con);
 702                         spin_lock_bh(&s->idr_lock);
 703                 }
 704         }
 705         spin_unlock_bh(&s->idr_lock);
 706
 707         tipc_work_stop(s);
 708         kmem_cache_destroy(s->rcvbuf_cache);
 709         idr_destroy(&s->conn_idr);
 710 }