bridge.c

   1 /*
   2  * netifd - network interface daemon
   3  * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14 #include <string.h>
  15 #include <stdlib.h>
  16 #include <stdio.h>
  17 #include <assert.h>
  18 #include <errno.h>
  19
  20 #include "netifd.h"
  21 #include "device.h"
  22 #include "interface.h"
  23 #include "system.h"
  24
  25 enum {
  26         BRIDGE_ATTR_IFNAME,
  27         BRIDGE_ATTR_STP,
  28         BRIDGE_ATTR_FORWARD_DELAY,
  29         BRIDGE_ATTR_PRIORITY,
  30         BRIDGE_ATTR_IGMP_SNOOP,
  31         BRIDGE_ATTR_AGEING_TIME,
  32         BRIDGE_ATTR_HELLO_TIME,
  33         BRIDGE_ATTR_MAX_AGE,
  34         BRIDGE_ATTR_BRIDGE_EMPTY,
  35         BRIDGE_ATTR_MULTICAST_QUERIER,
  36         BRIDGE_ATTR_HASH_MAX,
  37         __BRIDGE_ATTR_MAX
  38 };
  39
  40 static const struct blobmsg_policy bridge_attrs[__BRIDGE_ATTR_MAX] = {
  41         [BRIDGE_ATTR_IFNAME] = { "ifname", BLOBMSG_TYPE_ARRAY },
  42         [BRIDGE_ATTR_STP] = { "stp", BLOBMSG_TYPE_BOOL },
  43         [BRIDGE_ATTR_FORWARD_DELAY] = { "forward_delay", BLOBMSG_TYPE_INT32 },
  44         [BRIDGE_ATTR_PRIORITY] = { "priority", BLOBMSG_TYPE_INT32 },
  45         [BRIDGE_ATTR_AGEING_TIME] = { "ageing_time", BLOBMSG_TYPE_INT32 },
  46         [BRIDGE_ATTR_HELLO_TIME] = { "hello_time", BLOBMSG_TYPE_INT32 },
  47         [BRIDGE_ATTR_MAX_AGE] = { "max_age", BLOBMSG_TYPE_INT32 },
  48         [BRIDGE_ATTR_IGMP_SNOOP] = { "igmp_snooping", BLOBMSG_TYPE_BOOL },
  49         [BRIDGE_ATTR_BRIDGE_EMPTY] = { "bridge_empty", BLOBMSG_TYPE_BOOL },
  50         [BRIDGE_ATTR_MULTICAST_QUERIER] = { "multicast_querier", BLOBMSG_TYPE_BOOL },
  51         [BRIDGE_ATTR_HASH_MAX] = { "hash_max", BLOBMSG_TYPE_INT32 },
  52 };
  53
  54 static const struct uci_blob_param_info bridge_attr_info[__BRIDGE_ATTR_MAX] = {
  55         [BRIDGE_ATTR_IFNAME] = { .type = BLOBMSG_TYPE_STRING },
  56 };
  57
  58 static const struct uci_blob_param_list bridge_attr_list = {
  59         .n_params = __BRIDGE_ATTR_MAX,
  60         .params = bridge_attrs,
  61         .info = bridge_attr_info,
  62
  63         .n_next = 1,
  64         .next = { &device_attr_list },
  65 };
  66
  67 static struct device *bridge_create(const char *name, struct blob_attr *attr);
  68 static void bridge_config_init(struct device *dev);
  69 static void bridge_free(struct device *dev);
  70 static void bridge_dump_info(struct device *dev, struct blob_buf *b);
  71 enum dev_change_type
  72 bridge_reload(struct device *dev, struct blob_attr *attr);
  73
  74 const struct device_type bridge_device_type = {
  75         .name = "Bridge",
  76         .config_params = &bridge_attr_list,
  77
  78         .create = bridge_create,
  79         .config_init = bridge_config_init,
  80         .reload = bridge_reload,
  81         .free = bridge_free,
  82         .dump_info = bridge_dump_info,
  83 };
  84
  85 struct bridge_state {
  86         struct device dev;
  87         device_state_cb set_state;
  88
  89         struct blob_attr *config_data;
  90         struct bridge_config config;
  91         struct blob_attr *ifnames;
  92         bool active;
  93         bool force_active;
  94
  95         struct uloop_timeout retry;
  96         struct bridge_member *primary_port;
  97         struct vlist_tree members;
  98         int n_present;
  99         int n_failed;
 100 };
 101
 102 struct bridge_member {
 103         struct vlist_node node;
 104         struct bridge_state *bst;
 105         struct device_user dev;
 106         bool present;
 107         char name[];
 108 };
 109
 110 static void
 111 bridge_reset_primary(struct bridge_state *bst)
 112 {
 113         struct bridge_member *bm;
 114
 115         if (!bst->primary_port &&
 116             (bst->dev.settings.flags & DEV_OPT_MACADDR))
 117                 return;
 118
 119         bst->primary_port = NULL;
 120         bst->dev.settings.flags &= ~DEV_OPT_MACADDR;
 121         vlist_for_each_element(&bst->members, bm, node) {
 122                 uint8_t *macaddr;
 123
 124                 if (!bm->present)
 125                         continue;
 126
 127                 bst->primary_port = bm;
 128                 if (bm->dev.dev->settings.flags & DEV_OPT_MACADDR)
 129                         macaddr = bm->dev.dev->settings.macaddr;
 130                 else
 131                         macaddr = bm->dev.dev->orig_settings.macaddr;
 132                 memcpy(bst->dev.settings.macaddr, macaddr, 6);
 133                 bst->dev.settings.flags |= DEV_OPT_MACADDR;
 134                 return;
 135         }
 136 }
 137
 138 static int
 139 bridge_disable_member(struct bridge_member *bm)
 140 {
 141         struct bridge_state *bst = bm->bst;
 142
 143         if (!bm->present)
 144                 return 0;
 145
 146         system_bridge_delif(&bst->dev, bm->dev.dev);
 147         device_release(&bm->dev);
 148
 149         device_broadcast_event(&bst->dev, DEV_EVENT_TOPO_CHANGE);
 150
 151         return 0;
 152 }
 153
 154 static int
 155 bridge_enable_interface(struct bridge_state *bst)
 156 {
 157         int ret;
 158
 159         if (bst->active)
 160                 return 0;
 161
 162         ret = system_bridge_addbr(&bst->dev, &bst->config);
 163         if (ret < 0)
 164                 return ret;
 165
 166         bst->active = true;
 167         return 0;
 168 }
 169
 170 static void
 171 bridge_disable_interface(struct bridge_state *bst)
 172 {
 173         if (!bst->active)
 174                 return;
 175
 176         system_bridge_delbr(&bst->dev);
 177         bst->active = false;
 178 }
 179
 180 static int
 181 bridge_enable_member(struct bridge_member *bm)
 182 {
 183         struct bridge_state *bst = bm->bst;
 184         int ret;
 185
 186         if (!bm->present)
 187                 return 0;
 188
 189         ret = bridge_enable_interface(bst);
 190         if (ret)
 191                 goto error;
 192
 193         /* Disable IPv6 for bridge members */
 194         if (!(bm->dev.dev->settings.flags & DEV_OPT_IPV6)) {
 195                 bm->dev.dev->settings.ipv6 = 0;
 196                 bm->dev.dev->settings.flags |= DEV_OPT_IPV6;
 197         }
 198
 199         ret = device_claim(&bm->dev);
 200         if (ret < 0)
 201                 goto error;
 202
 203         ret = system_bridge_addif(&bst->dev, bm->dev.dev);
 204         if (ret < 0) {
 205                 D(DEVICE, "Bridge device %s could not be added\n", bm->dev.dev->ifname);
 206                 goto error;
 207         }
 208
 209         device_set_present(&bst->dev, true);
 210         device_broadcast_event(&bst->dev, DEV_EVENT_TOPO_CHANGE);
 211
 212         return 0;
 213
 214 error:
 215         bst->n_failed++;
 216         bm->present = false;
 217         bst->n_present--;
 218         device_release(&bm->dev);
 219
 220         return ret;
 221 }
 222
 223 static void
 224 bridge_remove_member(struct bridge_member *bm)
 225 {
 226         struct bridge_state *bst = bm->bst;
 227
 228         if (!bm->present)
 229                 return;
 230
 231         if (bm == bst->primary_port)
 232                 bridge_reset_primary(bst);
 233
 234         if (bst->dev.active)
 235                 bridge_disable_member(bm);
 236
 237         bm->present = false;
 238         bm->bst->n_present--;
 239
 240         if (bst->config.bridge_empty)
 241                 return;
 242
 243         bst->force_active = false;
 244         if (bst->n_present == 0)
 245                 device_set_present(&bst->dev, false);
 246 }
 247
 248 static void
 249 bridge_free_member(struct bridge_member *bm)
 250 {
 251         struct device *dev = bm->dev.dev;
 252
 253         bridge_remove_member(bm);
 254         device_remove_user(&bm->dev);
 255
 256         /*
 257          * When reloading the config and moving a device from one bridge to
 258          * another, the other bridge may have tried to claim this device
 259          * before it was removed here.
 260          * Ensure that claiming the device is retried by toggling its present
 261          * state
 262          */
 263         if (dev->present) {
 264                 device_set_present(dev, false);
 265                 device_set_present(dev, true);
 266         }
 267
 268         free(bm);
 269 }
 270
 271 static void
 272 bridge_check_retry(struct bridge_state *bst)
 273 {
 274         if (!bst->n_failed)
 275                 return;
 276
 277         uloop_timeout_set(&bst->retry, 100);
 278 }
 279
 280 static void
 281 bridge_member_cb(struct device_user *dev, enum device_event ev)
 282 {
 283         struct bridge_member *bm = container_of(dev, struct bridge_member, dev);
 284         struct bridge_state *bst = bm->bst;
 285
 286         switch (ev) {
 287         case DEV_EVENT_ADD:
 288                 assert(!bm->present);
 289
 290                 bm->present = true;
 291                 bst->n_present++;
 292
 293                 if (bst->n_present == 1)
 294                         device_set_present(&bst->dev, true);
 295                 if (bst->dev.active && !bridge_enable_member(bm)) {
 296                         /*
 297                          * Adding a bridge member can overwrite the bridge mtu
 298                          * in the kernel, apply the bridge settings in case the
 299                          * bridge mtu is set
 300                          */
 301                         system_if_apply_settings(&bst->dev, &bst->dev.settings,
 302                                                  DEV_OPT_MTU | DEV_OPT_MTU6);
 303                 }
 304
 305                 break;
 306         case DEV_EVENT_REMOVE:
 307                 if (dev->hotplug) {
 308                         vlist_delete(&bst->members, &bm->node);
 309                         return;
 310                 }
 311
 312                 if (bm->present)
 313                         bridge_remove_member(bm);
 314
 315                 break;
 316         default:
 317                 return;
 318         }
 319 }
 320
 321 static int
 322 bridge_set_down(struct bridge_state *bst)
 323 {
 324         struct bridge_member *bm;
 325
 326         bst->set_state(&bst->dev, false);
 327
 328         vlist_for_each_element(&bst->members, bm, node)
 329                 bridge_disable_member(bm);
 330
 331         bridge_disable_interface(bst);
 332
 333         return 0;
 334 }
 335
 336 static int
 337 bridge_set_up(struct bridge_state *bst)
 338 {
 339         struct bridge_member *bm;
 340         int ret;
 341
 342         if (!bst->n_present) {
 343                 if (!bst->force_active)
 344                         return -ENOENT;
 345
 346                 ret = bridge_enable_interface(bst);
 347                 if (ret)
 348                         return ret;
 349         }
 350
 351         bst->n_failed = 0;
 352         vlist_for_each_element(&bst->members, bm, node)
 353                 bridge_enable_member(bm);
 354         bridge_check_retry(bst);
 355
 356         if (!bst->force_active && !bst->n_present) {
 357                 /* initialization of all member interfaces failed */
 358                 bridge_disable_interface(bst);
 359                 device_set_present(&bst->dev, false);
 360                 return -ENOENT;
 361         }
 362
 363         bridge_reset_primary(bst);
 364         ret = bst->set_state(&bst->dev, true);
 365         if (ret < 0)
 366                 bridge_set_down(bst);
 367
 368         return ret;
 369 }
 370
 371 static int
 372 bridge_set_state(struct device *dev, bool up)
 373 {
 374         struct bridge_state *bst;
 375
 376         bst = container_of(dev, struct bridge_state, dev);
 377
 378         if (up)
 379                 return bridge_set_up(bst);
 380         else
 381                 return bridge_set_down(bst);
 382 }
 383
 384 static struct bridge_member *
 385 bridge_create_member(struct bridge_state *bst, struct device *dev, bool hotplug)
 386 {
 387         struct bridge_member *bm;
 388
 389         bm = calloc(1, sizeof(*bm) + strlen(dev->ifname) + 1);
 390         if (!bm)
 391                 return NULL;
 392
 393         bm->bst = bst;
 394         bm->dev.cb = bridge_member_cb;
 395         bm->dev.hotplug = hotplug;
 396         strcpy(bm->name, dev->ifname);
 397         bm->dev.dev = dev;
 398         vlist_add(&bst->members, &bm->node, bm->name);
 399         // Need to look up the bridge member again as the above
 400         // created pointer will be freed in case the bridge member
 401         // already existed
 402         bm = vlist_find(&bst->members, dev->ifname, bm, node);
 403         if (hotplug && bm)
 404                 bm->node.version = -1;
 405
 406         return bm;
 407 }
 408
 409 static void
 410 bridge_member_update(struct vlist_tree *tree, struct vlist_node *node_new,
 411                      struct vlist_node *node_old)
 412 {
 413         struct bridge_member *bm;
 414         struct device *dev;
 415
 416         if (node_new) {
 417                 bm = container_of(node_new, struct bridge_member, node);
 418
 419                 if (node_old) {
 420                         free(bm);
 421                         return;
 422                 }
 423
 424                 dev = bm->dev.dev;
 425                 bm->dev.dev = NULL;
 426                 device_add_user(&bm->dev, dev);
 427         }
 428
 429
 430         if (node_old) {
 431                 bm = container_of(node_old, struct bridge_member, node);
 432                 bridge_free_member(bm);
 433         }
 434 }
 435
 436
 437 static void
 438 bridge_add_member(struct bridge_state *bst, const char *name)
 439 {
 440         struct device *dev;
 441
 442         dev = device_get(name, true);
 443         if (!dev)
 444                 return;
 445
 446         bridge_create_member(bst, dev, false);
 447 }
 448
 449 static int
 450 bridge_hotplug_add(struct device *dev, struct device *member)
 451 {
 452         struct bridge_state *bst = container_of(dev, struct bridge_state, dev);
 453
 454         bridge_create_member(bst, member, true);
 455
 456         return 0;
 457 }
 458
 459 static int
 460 bridge_hotplug_del(struct device *dev, struct device *member)
 461 {
 462         struct bridge_state *bst = container_of(dev, struct bridge_state, dev);
 463         struct bridge_member *bm;
 464
 465         bm = vlist_find(&bst->members, member->ifname, bm, node);
 466         if (!bm)
 467                 return UBUS_STATUS_NOT_FOUND;
 468
 469         vlist_delete(&bst->members, &bm->node);
 470         return 0;
 471 }
 472
 473 static int
 474 bridge_hotplug_prepare(struct device *dev)
 475 {
 476         struct bridge_state *bst;
 477
 478         bst = container_of(dev, struct bridge_state, dev);
 479         bst->force_active = true;
 480         device_set_present(&bst->dev, true);
 481
 482         return 0;
 483 }
 484
 485 static const struct device_hotplug_ops bridge_ops = {
 486         .prepare = bridge_hotplug_prepare,
 487         .add = bridge_hotplug_add,
 488         .del = bridge_hotplug_del
 489 };
 490
 491 static void
 492 bridge_free(struct device *dev)
 493 {
 494         struct bridge_state *bst;
 495
 496         bst = container_of(dev, struct bridge_state, dev);
 497         vlist_flush_all(&bst->members);
 498         free(bst->config_data);
 499         free(bst);
 500 }
 501
 502 static void
 503 bridge_dump_info(struct device *dev, struct blob_buf *b)
 504 {
 505         struct bridge_state *bst;
 506         struct bridge_member *bm;
 507         void *list;
 508
 509         bst = container_of(dev, struct bridge_state, dev);
 510
 511         system_if_dump_info(dev, b);
 512         list = blobmsg_open_array(b, "bridge-members");
 513
 514         vlist_for_each_element(&bst->members, bm, node)
 515                 blobmsg_add_string(b, NULL, bm->dev.dev->ifname);
 516
 517         blobmsg_close_array(b, list);
 518 }
 519
 520 static void
 521 bridge_config_init(struct device *dev)
 522 {
 523         struct bridge_state *bst;
 524         struct blob_attr *cur;
 525         int rem;
 526
 527         bst = container_of(dev, struct bridge_state, dev);
 528
 529         if (bst->config.bridge_empty) {
 530                 bst->force_active = true;
 531                 device_set_present(&bst->dev, true);
 532         }
 533
 534         bst->n_failed = 0;
 535         vlist_update(&bst->members);
 536         if (bst->ifnames) {
 537                 blobmsg_for_each_attr(cur, bst->ifnames, rem) {
 538                         bridge_add_member(bst, blobmsg_data(cur));
 539                 }
 540         }
 541         vlist_flush(&bst->members);
 542         bridge_check_retry(bst);
 543 }
 544
 545 static void
 546 bridge_apply_settings(struct bridge_state *bst, struct blob_attr **tb)
 547 {
 548         struct bridge_config *cfg = &bst->config;
 549         struct blob_attr *cur;
 550
 551         /* defaults */
 552         cfg->stp = false;
 553         cfg->forward_delay = 2;
 554         cfg->igmp_snoop = true;
 555         cfg->multicast_querier = true;
 556         cfg->hash_max = 512;
 557         cfg->bridge_empty = false;
 558         cfg->priority = 0x7FFF;
 559
 560         if ((cur = tb[BRIDGE_ATTR_STP]))
 561                 cfg->stp = blobmsg_get_bool(cur);
 562
 563         if ((cur = tb[BRIDGE_ATTR_FORWARD_DELAY]))
 564                 cfg->forward_delay = blobmsg_get_u32(cur);
 565
 566         if ((cur = tb[BRIDGE_ATTR_PRIORITY]))
 567                 cfg->priority = blobmsg_get_u32(cur);
 568
 569         if ((cur = tb[BRIDGE_ATTR_IGMP_SNOOP]))
 570                 cfg->multicast_querier = cfg->igmp_snoop = blobmsg_get_bool(cur);
 571
 572         if ((cur = tb[BRIDGE_ATTR_MULTICAST_QUERIER]))
 573                 cfg->multicast_querier = blobmsg_get_bool(cur);
 574
 575         if ((cur = tb[BRIDGE_ATTR_HASH_MAX]))
 576                 cfg->hash_max = blobmsg_get_u32(cur);
 577
 578         if ((cur = tb[BRIDGE_ATTR_AGEING_TIME])) {
 579                 cfg->ageing_time = blobmsg_get_u32(cur);
 580                 cfg->flags |= BRIDGE_OPT_AGEING_TIME;
 581         }
 582
 583         if ((cur = tb[BRIDGE_ATTR_HELLO_TIME])) {
 584                 cfg->hello_time = blobmsg_get_u32(cur);
 585                 cfg->flags |= BRIDGE_OPT_HELLO_TIME;
 586         }
 587
 588         if ((cur = tb[BRIDGE_ATTR_MAX_AGE])) {
 589                 cfg->max_age = blobmsg_get_u32(cur);
 590                 cfg->flags |= BRIDGE_OPT_MAX_AGE;
 591         }
 592
 593         if ((cur = tb[BRIDGE_ATTR_BRIDGE_EMPTY]))
 594                 cfg->bridge_empty = blobmsg_get_bool(cur);
 595 }
 596
 597 enum dev_change_type
 598 bridge_reload(struct device *dev, struct blob_attr *attr)
 599 {
 600         struct blob_attr *tb_dev[__DEV_ATTR_MAX];
 601         struct blob_attr *tb_br[__BRIDGE_ATTR_MAX];
 602         enum dev_change_type ret = DEV_CONFIG_APPLIED;
 603         unsigned long diff;
 604         struct bridge_state *bst;
 605
 606         BUILD_BUG_ON(sizeof(diff) < __BRIDGE_ATTR_MAX / 8);
 607         BUILD_BUG_ON(sizeof(diff) < __DEV_ATTR_MAX / 8);
 608
 609         bst = container_of(dev, struct bridge_state, dev);
 610         attr = blob_memdup(attr);
 611
 612         blobmsg_parse(device_attr_list.params, __DEV_ATTR_MAX, tb_dev,
 613                 blob_data(attr), blob_len(attr));
 614         blobmsg_parse(bridge_attrs, __BRIDGE_ATTR_MAX, tb_br,
 615                 blob_data(attr), blob_len(attr));
 616
 617         bst->ifnames = tb_br[BRIDGE_ATTR_IFNAME];
 618         device_init_settings(dev, tb_dev);
 619         bridge_apply_settings(bst, tb_br);
 620
 621         if (bst->config_data) {
 622                 struct blob_attr *otb_dev[__DEV_ATTR_MAX];
 623                 struct blob_attr *otb_br[__BRIDGE_ATTR_MAX];
 624
 625                 blobmsg_parse(device_attr_list.params, __DEV_ATTR_MAX, otb_dev,
 626                         blob_data(bst->config_data), blob_len(bst->config_data));
 627
 628                 diff = 0;
 629                 uci_blob_diff(tb_dev, otb_dev, &device_attr_list, &diff);
 630                 if (diff)
 631                     ret = DEV_CONFIG_RESTART;
 632
 633                 blobmsg_parse(bridge_attrs, __BRIDGE_ATTR_MAX, otb_br,
 634                         blob_data(bst->config_data), blob_len(bst->config_data));
 635
 636                 diff = 0;
 637                 uci_blob_diff(tb_br, otb_br, &bridge_attr_list, &diff);
 638                 if (diff & ~(1 << BRIDGE_ATTR_IFNAME))
 639                     ret = DEV_CONFIG_RESTART;
 640
 641                 bridge_config_init(dev);
 642         }
 643
 644         free(bst->config_data);
 645         bst->config_data = attr;
 646         return ret;
 647 }
 648
 649 static void
 650 bridge_retry_members(struct uloop_timeout *timeout)
 651 {
 652         struct bridge_state *bst = container_of(timeout, struct bridge_state, retry);
 653         struct bridge_member *bm;
 654
 655         bst->n_failed = 0;
 656         vlist_for_each_element(&bst->members, bm, node) {
 657                 if (bm->present)
 658                         continue;
 659
 660                 if (!bm->dev.dev->present)
 661                         continue;
 662
 663                 bm->present = true;
 664                 bst->n_present++;
 665                 bridge_enable_member(bm);
 666         }
 667 }
 668
 669 static struct device *
 670 bridge_create(const char *name, struct blob_attr *attr)
 671 {
 672         struct bridge_state *bst;
 673         struct device *dev = NULL;
 674
 675         bst = calloc(1, sizeof(*bst));
 676         if (!bst)
 677                 return NULL;
 678
 679         dev = &bst->dev;
 680         device_init(dev, &bridge_device_type, name);
 681         dev->config_pending = true;
 682         bst->retry.cb = bridge_retry_members;
 683
 684         bst->set_state = dev->set_state;
 685         dev->set_state = bridge_set_state;
 686
 687         dev->hotplug_ops = &bridge_ops;
 688
 689         vlist_init(&bst->members, avl_strcmp, bridge_member_update);
 690         bst->members.keep_old = true;
 691         bridge_reload(dev, attr);
 692
 693         return dev;
 694 }