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