bridge.c

   1 #include <string.h>
   2 #include <stdlib.h>
   3 #include <stdio.h>
   4 #include <assert.h>
   5 #include <errno.h>
   6
   7 #include "netifd.h"
   8 #include "device.h"
   9 #include "interface.h"
  10 #include "system.h"
  11
  12 enum {
  13         BRIDGE_ATTR_IFNAME,
  14         BRIDGE_ATTR_STP,
  15         BRIDGE_ATTR_FORWARD_DELAY,
  16         BRIDGE_ATTR_IGMP_SNOOP,
  17         BRIDGE_ATTR_AGEING_TIME,
  18         BRIDGE_ATTR_HELLO_TIME,
  19         BRIDGE_ATTR_MAX_AGE,
  20         __BRIDGE_ATTR_MAX
  21 };
  22
  23 static const struct blobmsg_policy bridge_attrs[__BRIDGE_ATTR_MAX] = {
  24         [BRIDGE_ATTR_IFNAME] = { "ifname", BLOBMSG_TYPE_ARRAY },
  25         [BRIDGE_ATTR_STP] = { "stp", BLOBMSG_TYPE_BOOL },
  26         [BRIDGE_ATTR_FORWARD_DELAY] = { "forward_delay", BLOBMSG_TYPE_INT32 },
  27         [BRIDGE_ATTR_AGEING_TIME] = { "ageing_time", BLOBMSG_TYPE_INT32 },
  28         [BRIDGE_ATTR_HELLO_TIME] = { "hello_time", BLOBMSG_TYPE_INT32 },
  29         [BRIDGE_ATTR_MAX_AGE] = { "max_age", BLOBMSG_TYPE_INT32 },
  30         [BRIDGE_ATTR_IGMP_SNOOP] = { "igmp_snooping", BLOBMSG_TYPE_BOOL },
  31 };
  32
  33 static const union config_param_info bridge_attr_info[__BRIDGE_ATTR_MAX] = {
  34         [BRIDGE_ATTR_IFNAME] = { .type = BLOBMSG_TYPE_STRING },
  35 };
  36
  37 static const struct config_param_list bridge_attr_list = {
  38         .n_params = __BRIDGE_ATTR_MAX,
  39         .params = bridge_attrs,
  40         .info = bridge_attr_info,
  41
  42         .n_next = 1,
  43         .next = { &device_attr_list },
  44 };
  45
  46 static struct device *bridge_create(const char *name, struct blob_attr *attr);
  47 static void bridge_config_init(struct device *dev);
  48 static void bridge_free(struct device *dev);
  49 static void bridge_dump_info(struct device *dev, struct blob_buf *b);
  50
  51 const struct device_type bridge_device_type = {
  52         .name = "Bridge",
  53         .config_params = &bridge_attr_list,
  54
  55         .create = bridge_create,
  56         .config_init = bridge_config_init,
  57         .free = bridge_free,
  58         .dump_info = bridge_dump_info,
  59 };
  60
  61 struct bridge_state {
  62         struct device dev;
  63         device_state_cb set_state;
  64
  65         struct bridge_config config;
  66         struct blob_attr *ifnames;
  67         bool active;
  68         bool force_active;
  69
  70         struct vlist_tree members;
  71         int n_present;
  72 };
  73
  74 struct bridge_member {
  75         struct vlist_node node;
  76         struct bridge_state *bst;
  77         struct device_user dev;
  78         bool present;
  79         char name[];
  80 };
  81
  82 static int
  83 bridge_disable_member(struct bridge_member *bm)
  84 {
  85         struct bridge_state *bst = bm->bst;
  86
  87         if (!bm->present)
  88                 return 0;
  89
  90         system_bridge_delif(&bst->dev, bm->dev.dev);
  91         device_release(&bm->dev);
  92
  93         return 0;
  94 }
  95
  96 static int
  97 bridge_enable_member(struct bridge_member *bm)
  98 {
  99         struct bridge_state *bst = bm->bst;
 100         int ret;
 101
 102         if (!bm->present)
 103                 return 0;
 104
 105         ret = device_claim(&bm->dev);
 106         if (ret < 0)
 107                 goto error;
 108
 109         ret = system_bridge_addif(&bst->dev, bm->dev.dev);
 110         if (ret < 0)
 111                 goto error;
 112
 113         return 0;
 114
 115 error:
 116         bm->present = false;
 117         bst->n_present--;
 118         return ret;
 119 }
 120
 121 static void
 122 bridge_remove_member(struct bridge_member *bm)
 123 {
 124         struct bridge_state *bst = bm->bst;
 125
 126         if (!bm->present)
 127                 return;
 128
 129         bm->present = false;
 130         bm->bst->n_present--;
 131         if (bst->dev.active)
 132                 bridge_disable_member(bm);
 133
 134         bst->force_active = false;
 135         if (bst->n_present == 0)
 136                 device_set_present(&bst->dev, false);
 137 }
 138
 139 static void
 140 bridge_member_cb(struct device_user *dev, enum device_event ev)
 141 {
 142         struct bridge_member *bm = container_of(dev, struct bridge_member, dev);
 143         struct bridge_state *bst = bm->bst;
 144
 145         switch (ev) {
 146         case DEV_EVENT_ADD:
 147                 assert(!bm->present);
 148
 149                 bm->present = true;
 150                 bst->n_present++;
 151
 152                 if (bst->dev.active)
 153                         bridge_enable_member(bm);
 154                 else if (bst->n_present == 1)
 155                         device_set_present(&bst->dev, true);
 156
 157                 break;
 158         case DEV_EVENT_REMOVE:
 159                 if (!bm->present)
 160                         return;
 161
 162                 if (dev->hotplug)
 163                         vlist_delete(&bst->members, &bm->node);
 164                 else
 165                         bridge_remove_member(bm);
 166
 167                 break;
 168         default:
 169                 return;
 170         }
 171 }
 172
 173 static int
 174 bridge_set_down(struct bridge_state *bst)
 175 {
 176         struct bridge_member *bm;
 177
 178         bst->set_state(&bst->dev, false);
 179
 180         vlist_for_each_element(&bst->members, bm, node)
 181                 bridge_disable_member(bm);
 182
 183         system_bridge_delbr(&bst->dev);
 184
 185         return 0;
 186 }
 187
 188 static int
 189 bridge_set_up(struct bridge_state *bst)
 190 {
 191         struct bridge_member *bm;
 192         int ret;
 193
 194         if (!bst->force_active && !bst->n_present)
 195                 return -ENOENT;
 196
 197         ret = system_bridge_addbr(&bst->dev, &bst->config);
 198         if (ret < 0)
 199                 goto out;
 200
 201         vlist_for_each_element(&bst->members, bm, node)
 202                 bridge_enable_member(bm);
 203
 204         if (!bst->force_active && !bst->n_present) {
 205                 /* initialization of all member interfaces failed */
 206                 system_bridge_delbr(&bst->dev);
 207                 device_set_present(&bst->dev, false);
 208                 return -ENOENT;
 209         }
 210
 211         ret = bst->set_state(&bst->dev, true);
 212         if (ret < 0)
 213                 bridge_set_down(bst);
 214
 215 out:
 216         return ret;
 217 }
 218
 219 static int
 220 bridge_set_state(struct device *dev, bool up)
 221 {
 222         struct bridge_state *bst;
 223
 224         bst = container_of(dev, struct bridge_state, dev);
 225
 226         if (up)
 227                 return bridge_set_up(bst);
 228         else
 229                 return bridge_set_down(bst);
 230 }
 231
 232 static struct bridge_member *
 233 bridge_create_member(struct bridge_state *bst, struct device *dev, bool hotplug)
 234 {
 235         struct bridge_member *bm;
 236
 237         bm = calloc(1, sizeof(*bm) + strlen(dev->ifname) + 1);
 238         bm->bst = bst;
 239         bm->dev.cb = bridge_member_cb;
 240         bm->dev.hotplug = hotplug;
 241         strcpy(bm->name, dev->ifname);
 242         bm->dev.dev = dev;
 243         vlist_add(&bst->members, &bm->node, bm->name);
 244
 245         return bm;
 246 }
 247
 248 static void
 249 bridge_member_update(struct vlist_tree *tree, struct vlist_node *node_new,
 250                      struct vlist_node *node_old)
 251 {
 252         struct bridge_member *bm;
 253         struct device *dev;
 254
 255         if (node_new) {
 256                 bm = container_of(node_new, struct bridge_member, node);
 257
 258                 if (node_old) {
 259                         free(bm);
 260                         return;
 261                 }
 262
 263                 dev = bm->dev.dev;
 264                 bm->dev.dev = NULL;
 265                 device_add_user(&bm->dev, dev);
 266         }
 267
 268
 269         if (node_old) {
 270                 bm = container_of(node_old, struct bridge_member, node);
 271                 bridge_remove_member(bm);
 272                 device_remove_user(&bm->dev);
 273                 free(bm);
 274         }
 275 }
 276
 277
 278 static void
 279 bridge_add_member(struct bridge_state *bst, const char *name)
 280 {
 281         struct device *dev;
 282
 283         dev = device_get(name, true);
 284         if (!dev)
 285                 return;
 286
 287         bridge_create_member(bst, dev, false);
 288 }
 289
 290 static int
 291 bridge_hotplug_add(struct device *dev, struct device *member)
 292 {
 293         struct bridge_state *bst = container_of(dev, struct bridge_state, dev);
 294
 295         bridge_create_member(bst, member, true);
 296
 297         return 0;
 298 }
 299
 300 static int
 301 bridge_hotplug_del(struct device *dev, struct device *member)
 302 {
 303         struct bridge_state *bst = container_of(dev, struct bridge_state, dev);
 304         struct bridge_member *bm;
 305
 306         bm = vlist_find(&bst->members, member->ifname, bm, node);
 307         if (!bm)
 308                 return UBUS_STATUS_NOT_FOUND;
 309
 310         vlist_delete(&bst->members, &bm->node);
 311         return 0;
 312 }
 313
 314 static int
 315 bridge_hotplug_prepare(struct device *dev)
 316 {
 317         struct bridge_state *bst;
 318
 319         bst = container_of(dev, struct bridge_state, dev);
 320         bst->force_active = true;
 321         device_set_present(&bst->dev, true);
 322
 323         return 0;
 324 }
 325
 326 static const struct device_hotplug_ops bridge_ops = {
 327         .prepare = bridge_hotplug_prepare,
 328         .add = bridge_hotplug_add,
 329         .del = bridge_hotplug_del
 330 };
 331
 332 static void
 333 bridge_free(struct device *dev)
 334 {
 335         struct bridge_state *bst;
 336
 337         device_cleanup(dev);
 338         bst = container_of(dev, struct bridge_state, dev);
 339         vlist_flush_all(&bst->members);
 340         free(bst);
 341 }
 342
 343 static void
 344 bridge_dump_info(struct device *dev, struct blob_buf *b)
 345 {
 346         struct bridge_state *bst;
 347         struct bridge_member *bm;
 348         void *list;
 349
 350         bst = container_of(dev, struct bridge_state, dev);
 351
 352         system_if_dump_info(dev, b);
 353         list = blobmsg_open_array(b, "bridge-members");
 354
 355         vlist_for_each_element(&bst->members, bm, node)
 356                 blobmsg_add_string(b, NULL, bm->dev.dev->ifname);
 357
 358         blobmsg_close_array(b, list);
 359 }
 360
 361 static void
 362 bridge_config_init(struct device *dev)
 363 {
 364         struct bridge_state *bst;
 365         struct blob_attr *cur;
 366         int rem;
 367
 368         bst = container_of(dev, struct bridge_state, dev);
 369
 370         if (!bst->ifnames)
 371                 return;
 372
 373         blobmsg_for_each_attr(cur, bst->ifnames, rem) {
 374                 bridge_add_member(bst, blobmsg_data(cur));
 375         }
 376 }
 377
 378 static void
 379 bridge_apply_settings(struct bridge_state *bst, struct blob_attr **tb)
 380 {
 381         struct bridge_config *cfg = &bst->config;
 382         struct blob_attr *cur;
 383
 384         /* defaults */
 385         cfg->stp = true;
 386         cfg->forward_delay = 1;
 387         cfg->igmp_snoop = true;
 388
 389         if ((cur = tb[BRIDGE_ATTR_STP]))
 390                 cfg->stp = blobmsg_get_bool(cur);
 391
 392         if ((cur = tb[BRIDGE_ATTR_FORWARD_DELAY]))
 393                 cfg->forward_delay = blobmsg_get_u32(cur);
 394
 395         if ((cur = tb[BRIDGE_ATTR_IGMP_SNOOP]))
 396                 cfg->igmp_snoop = blobmsg_get_bool(cur);
 397
 398         if ((cur = tb[BRIDGE_ATTR_AGEING_TIME])) {
 399                 cfg->ageing_time = blobmsg_get_u32(cur);
 400                 cfg->flags |= BRIDGE_OPT_AGEING_TIME;
 401         }
 402
 403         if ((cur = tb[BRIDGE_ATTR_HELLO_TIME])) {
 404                 cfg->hello_time = blobmsg_get_u32(cur);
 405                 cfg->flags |= BRIDGE_OPT_HELLO_TIME;
 406         }
 407
 408         if ((cur = tb[BRIDGE_ATTR_MAX_AGE])) {
 409                 cfg->max_age = blobmsg_get_u32(cur);
 410                 cfg->flags |= BRIDGE_OPT_MAX_AGE;
 411         }
 412 }
 413
 414 static struct device *
 415 bridge_create(const char *name, struct blob_attr *attr)
 416 {
 417         struct blob_attr *tb_dev[__DEV_ATTR_MAX];
 418         struct blob_attr *tb_br[__BRIDGE_ATTR_MAX];
 419         struct bridge_state *bst;
 420         struct device *dev = NULL;
 421
 422         blobmsg_parse(device_attr_list.params, __DEV_ATTR_MAX, tb_dev,
 423                 blob_data(attr), blob_len(attr));
 424         blobmsg_parse(bridge_attrs, __BRIDGE_ATTR_MAX, tb_br,
 425                 blob_data(attr), blob_len(attr));
 426
 427         bst = calloc(1, sizeof(*bst));
 428         if (!bst)
 429                 return NULL;
 430
 431         dev = &bst->dev;
 432         device_init(dev, &bridge_device_type, name);
 433         device_init_settings(dev, tb_dev);
 434         dev->config_pending = true;
 435         bst->ifnames = tb_br[BRIDGE_ATTR_IFNAME];
 436         bridge_apply_settings(bst, tb_br);
 437
 438         bst->set_state = dev->set_state;
 439         dev->set_state = bridge_set_state;
 440
 441         dev->hotplug_ops = &bridge_ops;
 442
 443         vlist_init(&bst->members, avl_strcmp, bridge_member_update);
 444         bst->members.keep_old = true;
 445
 446         return dev;
 447 }
 448
 449