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