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