net/tipc/bearer.c

   1 /*
   2  * net/tipc/bearer.c: TIPC bearer code
   3  *
   4  * Copyright (c) 1996-2006, 2013, Ericsson AB
   5  * Copyright (c) 2004-2006, 2010-2013, Wind River Systems
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the names of the copyright holders nor the names of its
  17  *    contributors may be used to endorse or promote products derived from
  18  *    this software without specific prior written permission.
  19  *
  20  * Alternatively, this software may be distributed under the terms of the
  21  * GNU General Public License ("GPL") version 2 as published by the Free
  22  * Software Foundation.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34  * POSSIBILITY OF SUCH DAMAGE.
  35  */
  36
  37 #include "core.h"
  38 #include "config.h"
  39 #include "bearer.h"
  40 #include "discover.h"
  41
  42 #define MAX_ADDR_STR 60
  43
  44 static struct tipc_media * const media_info_array[] = {
  45         &eth_media_info,
  46 #ifdef CONFIG_TIPC_MEDIA_IB
  47         &ib_media_info,
  48 #endif
  49         NULL
  50 };
  51
  52 struct tipc_bearer __rcu *bearer_list[MAX_BEARERS + 1];
  53
  54 static void bearer_disable(struct tipc_bearer *b_ptr, bool shutting_down);
  55
  56 /**
  57  * tipc_media_find - locates specified media object by name
  58  */
  59 struct tipc_media *tipc_media_find(const char *name)
  60 {
  61         u32 i;
  62
  63         for (i = 0; media_info_array[i] != NULL; i++) {
  64                 if (!strcmp(media_info_array[i]->name, name))
  65                         break;
  66         }
  67         return media_info_array[i];
  68 }
  69
  70 /**
  71  * media_find_id - locates specified media object by type identifier
  72  */
  73 static struct tipc_media *media_find_id(u8 type)
  74 {
  75         u32 i;
  76
  77         for (i = 0; media_info_array[i] != NULL; i++) {
  78                 if (media_info_array[i]->type_id == type)
  79                         break;
  80         }
  81         return media_info_array[i];
  82 }
  83
  84 /**
  85  * tipc_media_addr_printf - record media address in print buffer
  86  */
  87 void tipc_media_addr_printf(char *buf, int len, struct tipc_media_addr *a)
  88 {
  89         char addr_str[MAX_ADDR_STR];
  90         struct tipc_media *m_ptr;
  91         int ret;
  92
  93         m_ptr = media_find_id(a->media_id);
  94
  95         if (m_ptr && !m_ptr->addr2str(a, addr_str, sizeof(addr_str)))
  96                 ret = tipc_snprintf(buf, len, "%s(%s)", m_ptr->name, addr_str);
  97         else {
  98                 u32 i;
  99
 100                 ret = tipc_snprintf(buf, len, "UNKNOWN(%u)", a->media_id);
 101                 for (i = 0; i < sizeof(a->value); i++)
 102                         ret += tipc_snprintf(buf - ret, len + ret,
 103                                             "-%02x", a->value[i]);
 104         }
 105 }
 106
 107 /**
 108  * tipc_media_get_names - record names of registered media in buffer
 109  */
 110 struct sk_buff *tipc_media_get_names(void)
 111 {
 112         struct sk_buff *buf;
 113         int i;
 114
 115         buf = tipc_cfg_reply_alloc(MAX_MEDIA * TLV_SPACE(TIPC_MAX_MEDIA_NAME));
 116         if (!buf)
 117                 return NULL;
 118
 119         for (i = 0; media_info_array[i] != NULL; i++) {
 120                 tipc_cfg_append_tlv(buf, TIPC_TLV_MEDIA_NAME,
 121                                     media_info_array[i]->name,
 122                                     strlen(media_info_array[i]->name) + 1);
 123         }
 124         return buf;
 125 }
 126
 127 /**
 128  * bearer_name_validate - validate & (optionally) deconstruct bearer name
 129  * @name: ptr to bearer name string
 130  * @name_parts: ptr to area for bearer name components (or NULL if not needed)
 131  *
 132  * Returns 1 if bearer name is valid, otherwise 0.
 133  */
 134 static int bearer_name_validate(const char *name,
 135                                 struct tipc_bearer_names *name_parts)
 136 {
 137         char name_copy[TIPC_MAX_BEARER_NAME];
 138         char *media_name;
 139         char *if_name;
 140         u32 media_len;
 141         u32 if_len;
 142
 143         /* copy bearer name & ensure length is OK */
 144         name_copy[TIPC_MAX_BEARER_NAME - 1] = 0;
 145         /* need above in case non-Posix strncpy() doesn't pad with nulls */
 146         strncpy(name_copy, name, TIPC_MAX_BEARER_NAME);
 147         if (name_copy[TIPC_MAX_BEARER_NAME - 1] != 0)
 148                 return 0;
 149
 150         /* ensure all component parts of bearer name are present */
 151         media_name = name_copy;
 152         if_name = strchr(media_name, ':');
 153         if (if_name == NULL)
 154                 return 0;
 155         *(if_name++) = 0;
 156         media_len = if_name - media_name;
 157         if_len = strlen(if_name) + 1;
 158
 159         /* validate component parts of bearer name */
 160         if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
 161             (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME))
 162                 return 0;
 163
 164         /* return bearer name components, if necessary */
 165         if (name_parts) {
 166                 strcpy(name_parts->media_name, media_name);
 167                 strcpy(name_parts->if_name, if_name);
 168         }
 169         return 1;
 170 }
 171
 172 /**
 173  * tipc_bearer_find - locates bearer object with matching bearer name
 174  */
 175 struct tipc_bearer *tipc_bearer_find(const char *name)
 176 {
 177         struct tipc_bearer *b_ptr;
 178         u32 i;
 179
 180         for (i = 0; i < MAX_BEARERS; i++) {
 181                 b_ptr = rtnl_dereference(bearer_list[i]);
 182                 if (b_ptr && (!strcmp(b_ptr->name, name)))
 183                         return b_ptr;
 184         }
 185         return NULL;
 186 }
 187
 188 /**
 189  * tipc_bearer_get_names - record names of bearers in buffer
 190  */
 191 struct sk_buff *tipc_bearer_get_names(void)
 192 {
 193         struct sk_buff *buf;
 194         struct tipc_bearer *b;
 195         int i, j;
 196
 197         buf = tipc_cfg_reply_alloc(MAX_BEARERS * TLV_SPACE(TIPC_MAX_BEARER_NAME));
 198         if (!buf)
 199                 return NULL;
 200
 201         for (i = 0; media_info_array[i] != NULL; i++) {
 202                 for (j = 0; j < MAX_BEARERS; j++) {
 203                         b = rtnl_dereference(bearer_list[j]);
 204                         if (!b)
 205                                 continue;
 206                         if (b->media == media_info_array[i]) {
 207                                 tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME,
 208                                                     b->name,
 209                                                     strlen(b->name) + 1);
 210                         }
 211                 }
 212         }
 213         return buf;
 214 }
 215
 216 void tipc_bearer_add_dest(u32 bearer_id, u32 dest)
 217 {
 218         struct tipc_bearer *b_ptr;
 219
 220         rcu_read_lock();
 221         b_ptr = rcu_dereference_rtnl(bearer_list[bearer_id]);
 222         if (b_ptr) {
 223                 tipc_bcbearer_sort(&b_ptr->nodes, dest, true);
 224                 tipc_disc_add_dest(b_ptr->link_req);
 225         }
 226         rcu_read_unlock();
 227 }
 228
 229 void tipc_bearer_remove_dest(u32 bearer_id, u32 dest)
 230 {
 231         struct tipc_bearer *b_ptr;
 232
 233         rcu_read_lock();
 234         b_ptr = rcu_dereference_rtnl(bearer_list[bearer_id]);
 235         if (b_ptr) {
 236                 tipc_bcbearer_sort(&b_ptr->nodes, dest, false);
 237                 tipc_disc_remove_dest(b_ptr->link_req);
 238         }
 239         rcu_read_unlock();
 240 }
 241
 242 /**
 243  * tipc_enable_bearer - enable bearer with the given name
 244  */
 245 int tipc_enable_bearer(const char *name, u32 disc_domain, u32 priority)
 246 {
 247         struct tipc_bearer *b_ptr;
 248         struct tipc_media *m_ptr;
 249         struct tipc_bearer_names b_names;
 250         char addr_string[16];
 251         u32 bearer_id;
 252         u32 with_this_prio;
 253         u32 i;
 254         int res = -EINVAL;
 255
 256         if (!tipc_own_addr) {
 257                 pr_warn("Bearer <%s> rejected, not supported in standalone mode\n",
 258                         name);
 259                 return -ENOPROTOOPT;
 260         }
 261         if (!bearer_name_validate(name, &b_names)) {
 262                 pr_warn("Bearer <%s> rejected, illegal name\n", name);
 263                 return -EINVAL;
 264         }
 265         if (tipc_addr_domain_valid(disc_domain) &&
 266             (disc_domain != tipc_own_addr)) {
 267                 if (tipc_in_scope(disc_domain, tipc_own_addr)) {
 268                         disc_domain = tipc_own_addr & TIPC_CLUSTER_MASK;
 269                         res = 0;   /* accept any node in own cluster */
 270                 } else if (in_own_cluster_exact(disc_domain))
 271                         res = 0;   /* accept specified node in own cluster */
 272         }
 273         if (res) {
 274                 pr_warn("Bearer <%s> rejected, illegal discovery domain\n",
 275                         name);
 276                 return -EINVAL;
 277         }
 278         if ((priority > TIPC_MAX_LINK_PRI) &&
 279             (priority != TIPC_MEDIA_LINK_PRI)) {
 280                 pr_warn("Bearer <%s> rejected, illegal priority\n", name);
 281                 return -EINVAL;
 282         }
 283
 284         m_ptr = tipc_media_find(b_names.media_name);
 285         if (!m_ptr) {
 286                 pr_warn("Bearer <%s> rejected, media <%s> not registered\n",
 287                         name, b_names.media_name);
 288                 return -EINVAL;
 289         }
 290
 291         if (priority == TIPC_MEDIA_LINK_PRI)
 292                 priority = m_ptr->priority;
 293
 294 restart:
 295         bearer_id = MAX_BEARERS;
 296         with_this_prio = 1;
 297         for (i = MAX_BEARERS; i-- != 0; ) {
 298                 b_ptr = rtnl_dereference(bearer_list[i]);
 299                 if (!b_ptr) {
 300                         bearer_id = i;
 301                         continue;
 302                 }
 303                 if (!strcmp(name, b_ptr->name)) {
 304                         pr_warn("Bearer <%s> rejected, already enabled\n",
 305                                 name);
 306                         return -EINVAL;
 307                 }
 308                 if ((b_ptr->priority == priority) &&
 309                     (++with_this_prio > 2)) {
 310                         if (priority-- == 0) {
 311                                 pr_warn("Bearer <%s> rejected, duplicate priority\n",
 312                                         name);
 313                                 return -EINVAL;
 314                         }
 315                         pr_warn("Bearer <%s> priority adjustment required %u->%u\n",
 316                                 name, priority + 1, priority);
 317                         goto restart;
 318                 }
 319         }
 320         if (bearer_id >= MAX_BEARERS) {
 321                 pr_warn("Bearer <%s> rejected, bearer limit reached (%u)\n",
 322                         name, MAX_BEARERS);
 323                 return -EINVAL;
 324         }
 325
 326         b_ptr = kzalloc(sizeof(*b_ptr), GFP_ATOMIC);
 327         if (!b_ptr)
 328                 return -ENOMEM;
 329
 330         strcpy(b_ptr->name, name);
 331         b_ptr->media = m_ptr;
 332         res = m_ptr->enable_media(b_ptr);
 333         if (res) {
 334                 pr_warn("Bearer <%s> rejected, enable failure (%d)\n",
 335                         name, -res);
 336                 return -EINVAL;
 337         }
 338
 339         b_ptr->identity = bearer_id;
 340         b_ptr->tolerance = m_ptr->tolerance;
 341         b_ptr->window = m_ptr->window;
 342         b_ptr->domain = disc_domain;
 343         b_ptr->net_plane = bearer_id + 'A';
 344         b_ptr->priority = priority;
 345
 346         res = tipc_disc_create(b_ptr, &b_ptr->bcast_addr);
 347         if (res) {
 348                 bearer_disable(b_ptr, false);
 349                 pr_warn("Bearer <%s> rejected, discovery object creation failed\n",
 350                         name);
 351                 return -EINVAL;
 352         }
 353
 354         rcu_assign_pointer(bearer_list[bearer_id], b_ptr);
 355
 356         pr_info("Enabled bearer <%s>, discovery domain %s, priority %u\n",
 357                 name,
 358                 tipc_addr_string_fill(addr_string, disc_domain), priority);
 359         return res;
 360 }
 361
 362 /**
 363  * tipc_reset_bearer - Reset all links established over this bearer
 364  */
 365 static int tipc_reset_bearer(struct tipc_bearer *b_ptr)
 366 {
 367         pr_info("Resetting bearer <%s>\n", b_ptr->name);
 368         tipc_link_reset_list(b_ptr->identity);
 369         tipc_disc_reset(b_ptr);
 370         return 0;
 371 }
 372
 373 /**
 374  * bearer_disable
 375  *
 376  * Note: This routine assumes caller holds RTNL lock.
 377  */
 378 static void bearer_disable(struct tipc_bearer *b_ptr, bool shutting_down)
 379 {
 380         u32 i;
 381
 382         pr_info("Disabling bearer <%s>\n", b_ptr->name);
 383         b_ptr->media->disable_media(b_ptr);
 384
 385         tipc_link_delete_list(b_ptr->identity, shutting_down);
 386         if (b_ptr->link_req)
 387                 tipc_disc_delete(b_ptr->link_req);
 388
 389         for (i = 0; i < MAX_BEARERS; i++) {
 390                 if (b_ptr == rtnl_dereference(bearer_list[i])) {
 391                         RCU_INIT_POINTER(bearer_list[i], NULL);
 392                         break;
 393                 }
 394         }
 395         kfree_rcu(b_ptr, rcu);
 396 }
 397
 398 int tipc_disable_bearer(const char *name)
 399 {
 400         struct tipc_bearer *b_ptr;
 401         int res;
 402
 403         b_ptr = tipc_bearer_find(name);
 404         if (b_ptr == NULL) {
 405                 pr_warn("Attempt to disable unknown bearer <%s>\n", name);
 406                 res = -EINVAL;
 407         } else {
 408                 bearer_disable(b_ptr, false);
 409                 res = 0;
 410         }
 411         return res;
 412 }
 413
 414 int tipc_enable_l2_media(struct tipc_bearer *b)
 415 {
 416         struct net_device *dev;
 417         char *driver_name = strchr((const char *)b->name, ':') + 1;
 418
 419         /* Find device with specified name */
 420         dev = dev_get_by_name(&init_net, driver_name);
 421         if (!dev)
 422                 return -ENODEV;
 423
 424         /* Associate TIPC bearer with L2 bearer */
 425         rcu_assign_pointer(b->media_ptr, dev);
 426         memset(&b->bcast_addr, 0, sizeof(b->bcast_addr));
 427         memcpy(b->bcast_addr.value, dev->broadcast, b->media->hwaddr_len);
 428         b->bcast_addr.media_id = b->media->type_id;
 429         b->bcast_addr.broadcast = 1;
 430         b->mtu = dev->mtu;
 431         b->media->raw2addr(b, &b->addr, (char *)dev->dev_addr);
 432         rcu_assign_pointer(dev->tipc_ptr, b);
 433         return 0;
 434 }
 435
 436 /* tipc_disable_l2_media - detach TIPC bearer from an L2 interface
 437  *
 438  * Mark L2 bearer as inactive so that incoming buffers are thrown away,
 439  * then get worker thread to complete bearer cleanup.  (Can't do cleanup
 440  * here because cleanup code needs to sleep and caller holds spinlocks.)
 441  */
 442 void tipc_disable_l2_media(struct tipc_bearer *b)
 443 {
 444         struct net_device *dev;
 445
 446         dev = (struct net_device *)rtnl_dereference(b->media_ptr);
 447         RCU_INIT_POINTER(b->media_ptr, NULL);
 448         RCU_INIT_POINTER(dev->tipc_ptr, NULL);
 449         synchronize_net();
 450         dev_put(dev);
 451 }
 452
 453 /**
 454  * tipc_l2_send_msg - send a TIPC packet out over an L2 interface
 455  * @buf: the packet to be sent
 456  * @b_ptr: the bearer through which the packet is to be sent
 457  * @dest: peer destination address
 458  */
 459 int tipc_l2_send_msg(struct sk_buff *buf, struct tipc_bearer *b,
 460                      struct tipc_media_addr *dest)
 461 {
 462         struct sk_buff *clone;
 463         struct net_device *dev;
 464         int delta;
 465
 466         dev = (struct net_device *)rcu_dereference_rtnl(b->media_ptr);
 467         if (!dev)
 468                 return 0;
 469
 470         clone = skb_clone(buf, GFP_ATOMIC);
 471         if (!clone)
 472                 return 0;
 473
 474         delta = dev->hard_header_len - skb_headroom(buf);
 475         if ((delta > 0) &&
 476             pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
 477                 kfree_skb(clone);
 478                 return 0;
 479         }
 480
 481         skb_reset_network_header(clone);
 482         clone->dev = dev;
 483         clone->protocol = htons(ETH_P_TIPC);
 484         dev_hard_header(clone, dev, ETH_P_TIPC, dest->value,
 485                         dev->dev_addr, clone->len);
 486         dev_queue_xmit(clone);
 487         return 0;
 488 }
 489
 490 /* tipc_bearer_send- sends buffer to destination over bearer
 491  *
 492  * IMPORTANT:
 493  * The media send routine must not alter the buffer being passed in
 494  * as it may be needed for later retransmission!
 495  */
 496 void tipc_bearer_send(u32 bearer_id, struct sk_buff *buf,
 497                       struct tipc_media_addr *dest)
 498 {
 499         struct tipc_bearer *b_ptr;
 500
 501         rcu_read_lock();
 502         b_ptr = rcu_dereference_rtnl(bearer_list[bearer_id]);
 503         if (likely(b_ptr))
 504                 b_ptr->media->send_msg(buf, b_ptr, dest);
 505         rcu_read_unlock();
 506 }
 507
 508 /**
 509  * tipc_l2_rcv_msg - handle incoming TIPC message from an interface
 510  * @buf: the received packet
 511  * @dev: the net device that the packet was received on
 512  * @pt: the packet_type structure which was used to register this handler
 513  * @orig_dev: the original receive net device in case the device is a bond
 514  *
 515  * Accept only packets explicitly sent to this node, or broadcast packets;
 516  * ignores packets sent using interface multicast, and traffic sent to other
 517  * nodes (which can happen if interface is running in promiscuous mode).
 518  */
 519 static int tipc_l2_rcv_msg(struct sk_buff *buf, struct net_device *dev,
 520                            struct packet_type *pt, struct net_device *orig_dev)
 521 {
 522         struct tipc_bearer *b_ptr;
 523
 524         if (!net_eq(dev_net(dev), &init_net)) {
 525                 kfree_skb(buf);
 526                 return NET_RX_DROP;
 527         }
 528
 529         rcu_read_lock();
 530         b_ptr = rcu_dereference_rtnl(dev->tipc_ptr);
 531         if (likely(b_ptr)) {
 532                 if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
 533                         buf->next = NULL;
 534                         tipc_rcv(buf, b_ptr);
 535                         rcu_read_unlock();
 536                         return NET_RX_SUCCESS;
 537                 }
 538         }
 539         rcu_read_unlock();
 540
 541         kfree_skb(buf);
 542         return NET_RX_DROP;
 543 }
 544
 545 /**
 546  * tipc_l2_device_event - handle device events from network device
 547  * @nb: the context of the notification
 548  * @evt: the type of event
 549  * @ptr: the net device that the event was on
 550  *
 551  * This function is called by the Ethernet driver in case of link
 552  * change event.
 553  */
 554 static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
 555                                 void *ptr)
 556 {
 557         struct tipc_bearer *b_ptr;
 558         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 559
 560         if (!net_eq(dev_net(dev), &init_net))
 561                 return NOTIFY_DONE;
 562
 563         b_ptr = rtnl_dereference(dev->tipc_ptr);
 564         if (!b_ptr)
 565                 return NOTIFY_DONE;
 566
 567         b_ptr->mtu = dev->mtu;
 568
 569         switch (evt) {
 570         case NETDEV_CHANGE:
 571                 if (netif_carrier_ok(dev))
 572                         break;
 573         case NETDEV_DOWN:
 574         case NETDEV_CHANGEMTU:
 575                 tipc_reset_bearer(b_ptr);
 576                 break;
 577         case NETDEV_CHANGEADDR:
 578                 b_ptr->media->raw2addr(b_ptr, &b_ptr->addr,
 579                                        (char *)dev->dev_addr);
 580                 tipc_reset_bearer(b_ptr);
 581                 break;
 582         case NETDEV_UNREGISTER:
 583         case NETDEV_CHANGENAME:
 584                 bearer_disable(b_ptr, false);
 585                 break;
 586         }
 587         return NOTIFY_OK;
 588 }
 589
 590 static struct packet_type tipc_packet_type __read_mostly = {
 591         .type = htons(ETH_P_TIPC),
 592         .func = tipc_l2_rcv_msg,
 593 };
 594
 595 static struct notifier_block notifier = {
 596         .notifier_call  = tipc_l2_device_event,
 597         .priority       = 0,
 598 };
 599
 600 int tipc_bearer_setup(void)
 601 {
 602         int err;
 603
 604         err = register_netdevice_notifier(&notifier);
 605         if (err)
 606                 return err;
 607         dev_add_pack(&tipc_packet_type);
 608         return 0;
 609 }
 610
 611 void tipc_bearer_cleanup(void)
 612 {
 613         unregister_netdevice_notifier(&notifier);
 614         dev_remove_pack(&tipc_packet_type);
 615 }
 616
 617 void tipc_bearer_stop(void)
 618 {
 619         struct tipc_bearer *b_ptr;
 620         u32 i;
 621
 622         for (i = 0; i < MAX_BEARERS; i++) {
 623                 b_ptr = rtnl_dereference(bearer_list[i]);
 624                 if (b_ptr) {
 625                         bearer_disable(b_ptr, true);
 626                         bearer_list[i] = NULL;
 627                 }
 628         }
 629 }