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
  69         struct list_head members;
  70         int n_present;
  71 };
  72
  73 struct bridge_member {
  74         struct list_head list;
  75         struct bridge_state *bst;
  76         struct device_user dev;
  77         bool present;
  78 };
  79
  80 static void bridge_free_member(struct bridge_member *bm);
  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         if (bst->n_present == 0)
 135                 device_set_present(&bst->dev, false);
 136 }
 137
 138 static void
 139 bridge_member_cb(struct device_user *dev, enum device_event ev)
 140 {
 141         struct bridge_member *bm = container_of(dev, struct bridge_member, dev);
 142         struct bridge_state *bst = bm->bst;
 143
 144         switch (ev) {
 145         case DEV_EVENT_ADD:
 146                 assert(!bm->present);
 147
 148                 bm->present = true;
 149                 bst->n_present++;
 150
 151                 if (bst->dev.active)
 152                         bridge_enable_member(bm);
 153                 else if (bst->n_present == 1)
 154                         device_set_present(&bst->dev, true);
 155
 156                 break;
 157         case DEV_EVENT_REMOVE:
 158                 if (!bm->present)
 159                         return;
 160
 161                 if (dev->hotplug)
 162                         bridge_free_member(bm);
 163                 else
 164                         bridge_remove_member(bm);
 165
 166                 break;
 167         default:
 168                 return;
 169         }
 170 }
 171
 172 static int
 173 bridge_set_down(struct bridge_state *bst)
 174 {
 175         struct bridge_member *bm;
 176
 177         bst->set_state(&bst->dev, false);
 178
 179         list_for_each_entry(bm, &bst->members, list)
 180                 bridge_disable_member(bm);
 181
 182         system_bridge_delbr(&bst->dev);
 183
 184         return 0;
 185 }
 186
 187 static int
 188 bridge_set_up(struct bridge_state *bst)
 189 {
 190         struct bridge_member *bm;
 191         int ret;
 192
 193         if (!bst->n_present)
 194                 return -ENOENT;
 195
 196         ret = system_bridge_addbr(&bst->dev, &bst->config);
 197         if (ret < 0)
 198                 goto out;
 199
 200         list_for_each_entry(bm, &bst->members, list)
 201                 bridge_enable_member(bm);
 202
 203         if (!bst->n_present) {
 204                 /* initialization of all member interfaces failed */
 205                 system_bridge_delbr(&bst->dev);
 206                 device_set_present(&bst->dev, false);
 207                 return -ENOENT;
 208         }
 209
 210         ret = bst->set_state(&bst->dev, true);
 211         if (ret < 0)
 212                 bridge_set_down(bst);
 213
 214 out:
 215         return ret;
 216 }
 217
 218 static int
 219 bridge_set_state(struct device *dev, bool up)
 220 {
 221         struct bridge_state *bst;
 222
 223         bst = container_of(dev, struct bridge_state, dev);
 224
 225         if (up)
 226                 return bridge_set_up(bst);
 227         else
 228                 return bridge_set_down(bst);
 229 }
 230
 231 static struct bridge_member *
 232 bridge_create_member(struct bridge_state *bst, struct device *dev, bool hotplug)
 233 {
 234         struct bridge_member *bm;
 235
 236         bm = calloc(1, sizeof(*bm));
 237         bm->bst = bst;
 238         bm->dev.cb = bridge_member_cb;
 239         bm->dev.hotplug = hotplug;
 240         list_add_tail(&bm->list, &bst->members);
 241
 242         device_add_user(&bm->dev, dev);
 243
 244         return bm;
 245 }
 246
 247 static void
 248 bridge_free_member(struct bridge_member *bm)
 249 {
 250         bridge_remove_member(bm);
 251         device_remove_user(&bm->dev);
 252         list_del(&bm->list);
 253         free(bm);
 254 }
 255
 256 static void
 257 bridge_add_member(struct bridge_state *bst, const char *name)
 258 {
 259         struct device *dev;
 260
 261         dev = device_get(name, true);
 262         if (!dev)
 263                 return;
 264
 265         bridge_create_member(bst, dev, false);
 266 }
 267
 268 static int
 269 bridge_hotplug_add(struct device *dev, struct device *member)
 270 {
 271         struct bridge_state *bst = container_of(dev, struct bridge_state, dev);
 272
 273         bridge_create_member(bst, member, true);
 274
 275         return 0;
 276 }
 277
 278 static int
 279 bridge_hotplug_del(struct device *dev, struct device *member)
 280 {
 281         struct bridge_state *bst = container_of(dev, struct bridge_state, dev);
 282         struct bridge_member *bm;
 283
 284         list_for_each_entry(bm, &bst->members, list) {
 285                 if (bm->dev.dev != member)
 286                         continue;
 287
 288                 bridge_free_member(bm);
 289                 return 0;
 290         }
 291
 292         return -ENOENT;
 293 }
 294
 295 static const struct device_hotplug_ops bridge_ops = {
 296         .add = bridge_hotplug_add,
 297         .del = bridge_hotplug_del
 298 };
 299
 300 static void
 301 bridge_free(struct device *dev)
 302 {
 303         struct bridge_state *bst;
 304         struct bridge_member *bm;
 305
 306         device_cleanup(dev);
 307         bst = container_of(dev, struct bridge_state, dev);
 308         while (!list_empty(&bst->members)) {
 309                 bm = list_first_entry(&bst->members, struct bridge_member, list);
 310                 bridge_free_member(bm);
 311         }
 312         free(bst);
 313 }
 314
 315 static void
 316 bridge_dump_info(struct device *dev, struct blob_buf *b)
 317 {
 318         struct bridge_state *bst;
 319         struct bridge_member *bm;
 320         void *list;
 321
 322         bst = container_of(dev, struct bridge_state, dev);
 323
 324         list = blobmsg_open_array(b, "bridge-members");
 325         list_for_each_entry(bm, &bst->members, list) {
 326                 blobmsg_add_string(b, NULL, bm->dev.dev->ifname);
 327         }
 328         blobmsg_close_array(b, list);
 329 }
 330
 331 static void
 332 bridge_config_init(struct device *dev)
 333 {
 334         struct bridge_state *bst;
 335         struct blob_attr *cur;
 336         int rem;
 337
 338         bst = container_of(dev, struct bridge_state, dev);
 339
 340         if (!bst->ifnames)
 341                 return;
 342
 343         blobmsg_for_each_attr(cur, bst->ifnames, rem) {
 344                 bridge_add_member(bst, blobmsg_data(cur));
 345         }
 346 }
 347
 348 static void
 349 bridge_apply_settings(struct bridge_state *bst, struct blob_attr **tb)
 350 {
 351         struct bridge_config *cfg = &bst->config;
 352         struct blob_attr *cur;
 353
 354         /* defaults */
 355         cfg->stp = true;
 356         cfg->forward_delay = 1;
 357         cfg->igmp_snoop = true;
 358
 359         if ((cur = tb[BRIDGE_ATTR_STP]))
 360                 cfg->stp = blobmsg_get_bool(cur);
 361
 362         if ((cur = tb[BRIDGE_ATTR_FORWARD_DELAY]))
 363                 cfg->forward_delay = blobmsg_get_u32(cur);
 364
 365         if ((cur = tb[BRIDGE_ATTR_IGMP_SNOOP]))
 366                 cfg->igmp_snoop = blobmsg_get_bool(cur);
 367
 368         if ((cur = tb[BRIDGE_ATTR_AGEING_TIME])) {
 369                 cfg->ageing_time = blobmsg_get_u32(cur);
 370                 cfg->flags |= BRIDGE_OPT_AGEING_TIME;
 371         }
 372
 373         if ((cur = tb[BRIDGE_ATTR_HELLO_TIME])) {
 374                 cfg->hello_time = blobmsg_get_u32(cur);
 375                 cfg->flags |= BRIDGE_OPT_HELLO_TIME;
 376         }
 377
 378         if ((cur = tb[BRIDGE_ATTR_MAX_AGE])) {
 379                 cfg->max_age = blobmsg_get_u32(cur);
 380                 cfg->flags |= BRIDGE_OPT_MAX_AGE;
 381         }
 382 }
 383
 384 static struct device *
 385 bridge_create(const char *name, struct blob_attr *attr)
 386 {
 387         struct blob_attr *tb_dev[__DEV_ATTR_MAX];
 388         struct blob_attr *tb_br[__BRIDGE_ATTR_MAX];
 389         struct bridge_state *bst;
 390         struct device *dev = NULL;
 391
 392         blobmsg_parse(device_attr_list.params, __DEV_ATTR_MAX, tb_dev,
 393                 blob_data(attr), blob_len(attr));
 394         blobmsg_parse(bridge_attrs, __BRIDGE_ATTR_MAX, tb_br,
 395                 blob_data(attr), blob_len(attr));
 396
 397         bst = calloc(1, sizeof(*bst));
 398         if (!bst)
 399                 return NULL;
 400
 401         dev = &bst->dev;
 402         device_init(dev, &bridge_device_type, name);
 403         device_init_settings(dev, tb_dev);
 404         dev->config_pending = true;
 405         bst->ifnames = tb_br[BRIDGE_ATTR_IFNAME];
 406         bridge_apply_settings(bst, tb_br);
 407
 408         bst->set_state = dev->set_state;
 409         dev->set_state = bridge_set_state;
 410
 411         dev->hotplug_ops = &bridge_ops;
 412
 413         INIT_LIST_HEAD(&bst->members);
 414
 415         return dev;
 416 }
 417
 418