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