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 *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 = 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         read_lock_bh(&tipc_net_lock);
 202         for (i = 0; media_info_array[i] != NULL; i++) {
 203                 for (j = 0; j < MAX_BEARERS; j++) {
 204                         b = bearer_list[j];
 205                         if (!b)
 206                                 continue;
 207                         if (b->media == media_info_array[i]) {
 208                                 tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME,
 209                                                     b->name,
 210                                                     strlen(b->name) + 1);
 211                         }
 212                 }
 213         }
 214         read_unlock_bh(&tipc_net_lock);
 215         return buf;
 216 }
 217
 218 void tipc_bearer_add_dest(struct tipc_bearer *b_ptr, u32 dest)
 219 {
 220         tipc_nmap_add(&b_ptr->nodes, dest);
 221         tipc_bcbearer_sort();
 222         tipc_disc_add_dest(b_ptr->link_req);
 223 }
 224
 225 void tipc_bearer_remove_dest(struct tipc_bearer *b_ptr, u32 dest)
 226 {
 227         tipc_nmap_remove(&b_ptr->nodes, dest);
 228         tipc_bcbearer_sort();
 229         tipc_disc_remove_dest(b_ptr->link_req);
 230 }
 231
 232 /**
 233  * tipc_enable_bearer - enable bearer with the given name
 234  */
 235 int tipc_enable_bearer(const char *name, u32 disc_domain, u32 priority)
 236 {
 237         struct tipc_bearer *b_ptr;
 238         struct tipc_media *m_ptr;
 239         struct tipc_bearer_names b_names;
 240         char addr_string[16];
 241         u32 bearer_id;
 242         u32 with_this_prio;
 243         u32 i;
 244         int res = -EINVAL;
 245
 246         if (!tipc_own_addr) {
 247                 pr_warn("Bearer <%s> rejected, not supported in standalone mode\n",
 248                         name);
 249                 return -ENOPROTOOPT;
 250         }
 251         if (!bearer_name_validate(name, &b_names)) {
 252                 pr_warn("Bearer <%s> rejected, illegal name\n", name);
 253                 return -EINVAL;
 254         }
 255         if (tipc_addr_domain_valid(disc_domain) &&
 256             (disc_domain != tipc_own_addr)) {
 257                 if (tipc_in_scope(disc_domain, tipc_own_addr)) {
 258                         disc_domain = tipc_own_addr & TIPC_CLUSTER_MASK;
 259                         res = 0;   /* accept any node in own cluster */
 260                 } else if (in_own_cluster_exact(disc_domain))
 261                         res = 0;   /* accept specified node in own cluster */
 262         }
 263         if (res) {
 264                 pr_warn("Bearer <%s> rejected, illegal discovery domain\n",
 265                         name);
 266                 return -EINVAL;
 267         }
 268         if ((priority > TIPC_MAX_LINK_PRI) &&
 269             (priority != TIPC_MEDIA_LINK_PRI)) {
 270                 pr_warn("Bearer <%s> rejected, illegal priority\n", name);
 271                 return -EINVAL;
 272         }
 273
 274         write_lock_bh(&tipc_net_lock);
 275
 276         m_ptr = tipc_media_find(b_names.media_name);
 277         if (!m_ptr) {
 278                 pr_warn("Bearer <%s> rejected, media <%s> not registered\n",
 279                         name, b_names.media_name);
 280                 goto exit;
 281         }
 282
 283         if (priority == TIPC_MEDIA_LINK_PRI)
 284                 priority = m_ptr->priority;
 285
 286 restart:
 287         bearer_id = MAX_BEARERS;
 288         with_this_prio = 1;
 289         for (i = MAX_BEARERS; i-- != 0; ) {
 290                 b_ptr = bearer_list[i];
 291                 if (!b_ptr) {
 292                         bearer_id = i;
 293                         continue;
 294                 }
 295                 if (!strcmp(name, b_ptr->name)) {
 296                         pr_warn("Bearer <%s> rejected, already enabled\n",
 297                                 name);
 298                         goto exit;
 299                 }
 300                 if ((b_ptr->priority == priority) &&
 301                     (++with_this_prio > 2)) {
 302                         if (priority-- == 0) {
 303                                 pr_warn("Bearer <%s> rejected, duplicate priority\n",
 304                                         name);
 305                                 goto exit;
 306                         }
 307                         pr_warn("Bearer <%s> priority adjustment required %u->%u\n",
 308                                 name, priority + 1, priority);
 309                         goto restart;
 310                 }
 311         }
 312         if (bearer_id >= MAX_BEARERS) {
 313                 pr_warn("Bearer <%s> rejected, bearer limit reached (%u)\n",
 314                         name, MAX_BEARERS);
 315                 goto exit;
 316         }
 317
 318         b_ptr = kzalloc(sizeof(*b_ptr), GFP_ATOMIC);
 319         if (!b_ptr) {
 320                 res = -ENOMEM;
 321                 goto exit;
 322         }
 323         strcpy(b_ptr->name, name);
 324         b_ptr->media = m_ptr;
 325         res = m_ptr->enable_media(b_ptr);
 326         if (res) {
 327                 pr_warn("Bearer <%s> rejected, enable failure (%d)\n",
 328                         name, -res);
 329                 goto exit;
 330         }
 331
 332         b_ptr->identity = bearer_id;
 333         b_ptr->tolerance = m_ptr->tolerance;
 334         b_ptr->window = m_ptr->window;
 335         b_ptr->net_plane = bearer_id + 'A';
 336         b_ptr->priority = priority;
 337
 338         res = tipc_disc_create(b_ptr, &b_ptr->bcast_addr, disc_domain);
 339         if (res) {
 340                 bearer_disable(b_ptr, false);
 341                 pr_warn("Bearer <%s> rejected, discovery object creation failed\n",
 342                         name);
 343                 goto exit;
 344         }
 345
 346         bearer_list[bearer_id] = b_ptr;
 347
 348         pr_info("Enabled bearer <%s>, discovery domain %s, priority %u\n",
 349                 name,
 350                 tipc_addr_string_fill(addr_string, disc_domain), priority);
 351 exit:
 352         write_unlock_bh(&tipc_net_lock);
 353         return res;
 354 }
 355
 356 /**
 357  * tipc_reset_bearer - Reset all links established over this bearer
 358  */
 359 static int tipc_reset_bearer(struct tipc_bearer *b_ptr)
 360 {
 361         read_lock_bh(&tipc_net_lock);
 362         pr_info("Resetting bearer <%s>\n", b_ptr->name);
 363         tipc_link_reset_list(b_ptr->identity);
 364         read_unlock_bh(&tipc_net_lock);
 365         return 0;
 366 }
 367
 368 /**
 369  * bearer_disable
 370  *
 371  * Note: This routine assumes caller holds tipc_net_lock.
 372  */
 373 static void bearer_disable(struct tipc_bearer *b_ptr, bool shutting_down)
 374 {
 375         u32 i;
 376
 377         pr_info("Disabling bearer <%s>\n", b_ptr->name);
 378         b_ptr->media->disable_media(b_ptr);
 379
 380         tipc_link_delete_list(b_ptr->identity, shutting_down);
 381         if (b_ptr->link_req)
 382                 tipc_disc_delete(b_ptr->link_req);
 383
 384         for (i = 0; i < MAX_BEARERS; i++) {
 385                 if (b_ptr == bearer_list[i]) {
 386                         bearer_list[i] = NULL;
 387                         break;
 388                 }
 389         }
 390         kfree(b_ptr);
 391 }
 392
 393 int tipc_disable_bearer(const char *name)
 394 {
 395         struct tipc_bearer *b_ptr;
 396         int res;
 397
 398         write_lock_bh(&tipc_net_lock);
 399         b_ptr = tipc_bearer_find(name);
 400         if (b_ptr == NULL) {
 401                 pr_warn("Attempt to disable unknown bearer <%s>\n", name);
 402                 res = -EINVAL;
 403         } else {
 404                 bearer_disable(b_ptr, false);
 405                 res = 0;
 406         }
 407         write_unlock_bh(&tipc_net_lock);
 408         return res;
 409 }
 410
 411
 412 /* tipc_l2_media_addr_set - initialize Ethernet media address structure
 413  *
 414  * Media-dependent "value" field stores MAC address in first 6 bytes
 415  * and zeroes out the remaining bytes.
 416  */
 417 void tipc_l2_media_addr_set(const struct tipc_bearer *b,
 418                             struct tipc_media_addr *a, char *mac)
 419 {
 420         int len = b->media->hwaddr_len;
 421
 422         if (unlikely(sizeof(a->value) < len)) {
 423                 WARN_ONCE(1, "Media length invalid\n");
 424                 return;
 425         }
 426
 427         memcpy(a->value, mac, len);
 428         memset(a->value + len, 0, sizeof(a->value) - len);
 429         a->media_id = b->media->type_id;
 430         a->broadcast = !memcmp(mac, b->bcast_addr.value, len);
 431 }
 432
 433 int tipc_enable_l2_media(struct tipc_bearer *b)
 434 {
 435         struct net_device *dev;
 436         char *driver_name = strchr((const char *)b->name, ':') + 1;
 437
 438         /* Find device with specified name */
 439         dev = dev_get_by_name(&init_net, driver_name);
 440         if (!dev)
 441                 return -ENODEV;
 442
 443         /* Associate TIPC bearer with Ethernet bearer */
 444         b->media_ptr = dev;
 445         memset(b->bcast_addr.value, 0, sizeof(b->bcast_addr.value));
 446         memcpy(b->bcast_addr.value, dev->broadcast, b->media->hwaddr_len);
 447         b->bcast_addr.media_id = b->media->type_id;
 448         b->bcast_addr.broadcast = 1;
 449         b->mtu = dev->mtu;
 450         tipc_l2_media_addr_set(b, &b->addr, (char *)dev->dev_addr);
 451         rcu_assign_pointer(dev->tipc_ptr, b);
 452         return 0;
 453 }
 454
 455 /* tipc_disable_l2_media - detach TIPC bearer from an Ethernet interface
 456  *
 457  * Mark Ethernet bearer as inactive so that incoming buffers are thrown away,
 458  * then get worker thread to complete bearer cleanup.  (Can't do cleanup
 459  * here because cleanup code needs to sleep and caller holds spinlocks.)
 460  */
 461 void tipc_disable_l2_media(struct tipc_bearer *b)
 462 {
 463         struct net_device *dev = (struct net_device *)b->media_ptr;
 464         RCU_INIT_POINTER(dev->tipc_ptr, NULL);
 465         dev_put(dev);
 466 }
 467
 468 /**
 469  * tipc_l2_send_msg - send a TIPC packet out over an Ethernet interface
 470  * @buf: the packet to be sent
 471  * @b_ptr: the bearer through which the packet is to be sent
 472  * @dest: peer destination address
 473  */
 474 int tipc_l2_send_msg(struct sk_buff *buf, struct tipc_bearer *b,
 475                      struct tipc_media_addr *dest)
 476 {
 477         struct sk_buff *clone;
 478         int delta;
 479         struct net_device *dev = (struct net_device *)b->media_ptr;
 480
 481         clone = skb_clone(buf, GFP_ATOMIC);
 482         if (!clone)
 483                 return 0;
 484
 485         delta = dev->hard_header_len - skb_headroom(buf);
 486         if ((delta > 0) &&
 487             pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
 488                 kfree_skb(clone);
 489                 return 0;
 490         }
 491
 492         skb_reset_network_header(clone);
 493         clone->dev = dev;
 494         clone->protocol = htons(ETH_P_TIPC);
 495         dev_hard_header(clone, dev, ETH_P_TIPC, dest->value,
 496                         dev->dev_addr, clone->len);
 497         dev_queue_xmit(clone);
 498         return 0;
 499 }
 500
 501 /* tipc_bearer_send- sends buffer to destination over bearer
 502  *
 503  * IMPORTANT:
 504  * The media send routine must not alter the buffer being passed in
 505  * as it may be needed for later retransmission!
 506  */
 507 void tipc_bearer_send(struct tipc_bearer *b, struct sk_buff *buf,
 508                       struct tipc_media_addr *dest)
 509 {
 510         b->media->send_msg(buf, b, dest);
 511 }
 512
 513 /**
 514  * tipc_l2_rcv_msg - handle incoming TIPC message from an interface
 515  * @buf: the received packet
 516  * @dev: the net device that the packet was received on
 517  * @pt: the packet_type structure which was used to register this handler
 518  * @orig_dev: the original receive net device in case the device is a bond
 519  *
 520  * Accept only packets explicitly sent to this node, or broadcast packets;
 521  * ignores packets sent using interface multicast, and traffic sent to other
 522  * nodes (which can happen if interface is running in promiscuous mode).
 523  */
 524 static int tipc_l2_rcv_msg(struct sk_buff *buf, struct net_device *dev,
 525                            struct packet_type *pt, struct net_device *orig_dev)
 526 {
 527         struct tipc_bearer *b_ptr;
 528
 529         if (!net_eq(dev_net(dev), &init_net)) {
 530                 kfree_skb(buf);
 531                 return NET_RX_DROP;
 532         }
 533
 534         rcu_read_lock();
 535         b_ptr = rcu_dereference(dev->tipc_ptr);
 536         if (likely(b_ptr)) {
 537                 if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
 538                         buf->next = NULL;
 539                         tipc_rcv(buf, b_ptr);
 540                         rcu_read_unlock();
 541                         return NET_RX_SUCCESS;
 542                 }
 543         }
 544         rcu_read_unlock();
 545
 546         kfree_skb(buf);
 547         return NET_RX_DROP;
 548 }
 549
 550 /**
 551  * tipc_l2_device_event - handle device events from network device
 552  * @nb: the context of the notification
 553  * @evt: the type of event
 554  * @ptr: the net device that the event was on
 555  *
 556  * This function is called by the Ethernet driver in case of link
 557  * change event.
 558  */
 559 static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
 560                                 void *ptr)
 561 {
 562         struct tipc_bearer *b_ptr;
 563         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 564
 565         if (!net_eq(dev_net(dev), &init_net))
 566                 return NOTIFY_DONE;
 567
 568         rcu_read_lock();
 569         b_ptr = rcu_dereference(dev->tipc_ptr);
 570         if (!b_ptr) {
 571                 rcu_read_unlock();
 572                 return NOTIFY_DONE;
 573         }
 574
 575         b_ptr->mtu = dev->mtu;
 576
 577         switch (evt) {
 578         case NETDEV_CHANGE:
 579                 if (netif_carrier_ok(dev))
 580                         break;
 581         case NETDEV_DOWN:
 582         case NETDEV_CHANGEMTU:
 583         case NETDEV_CHANGEADDR:
 584                 tipc_reset_bearer(b_ptr);
 585                 break;
 586         case NETDEV_UNREGISTER:
 587         case NETDEV_CHANGENAME:
 588                 tipc_disable_bearer(b_ptr->name);
 589                 break;
 590         }
 591         rcu_read_unlock();
 592
 593         return NOTIFY_OK;
 594 }
 595
 596 static struct packet_type tipc_packet_type __read_mostly = {
 597         .type = htons(ETH_P_TIPC),
 598         .func = tipc_l2_rcv_msg,
 599 };
 600
 601 static struct notifier_block notifier = {
 602         .notifier_call  = tipc_l2_device_event,
 603         .priority       = 0,
 604 };
 605
 606 int tipc_bearer_setup(void)
 607 {
 608         int err;
 609
 610         err = register_netdevice_notifier(&notifier);
 611         if (err)
 612                 return err;
 613         dev_add_pack(&tipc_packet_type);
 614         return 0;
 615 }
 616
 617 void tipc_bearer_cleanup(void)
 618 {
 619         unregister_netdevice_notifier(&notifier);
 620         dev_remove_pack(&tipc_packet_type);
 621 }
 622
 623 void tipc_bearer_stop(void)
 624 {
 625         struct tipc_bearer *b_ptr;
 626         u32 i;
 627
 628         for (i = 0; i < MAX_BEARERS; i++) {
 629                 b_ptr = bearer_list[i];
 630                 if (b_ptr) {
 631                         bearer_disable(b_ptr, true);
 632                         bearer_list[i] = NULL;
 633                 }
 634         }
 635 }