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