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_member_cb(struct device_user *dev, enum device_event ev)
 123 {
 124         struct bridge_member *bm = container_of(dev, struct bridge_member, dev);
 125         struct bridge_state *bst = bm->bst;
 126
 127         switch (ev) {
 128         case DEV_EVENT_ADD:
 129                 assert(!bm->present);
 130
 131                 bm->present = true;
 132                 bst->n_present++;
 133
 134                 if (bst->dev.active)
 135                         bridge_enable_member(bm);
 136                 else if (bst->n_present == 1)
 137                         device_set_present(&bst->dev, true);
 138
 139                 break;
 140         case DEV_EVENT_REMOVE:
 141                 if (!bm->present)
 142                         return;
 143
 144                 if (bst->dev.active)
 145                         bridge_disable_member(bm);
 146
 147                 bm->present = false;
 148                 bm->bst->n_present--;
 149                 if (bst->n_present == 0)
 150                         device_set_present(&bst->dev, false);
 151
 152                 if (dev->hotplug)
 153                         bridge_free_member(bm);
 154                 break;
 155         default:
 156                 return;
 157         }
 158 }
 159
 160 static int
 161 bridge_set_down(struct bridge_state *bst)
 162 {
 163         struct bridge_member *bm;
 164
 165         bst->set_state(&bst->dev, false);
 166
 167         list_for_each_entry(bm, &bst->members, list)
 168                 bridge_disable_member(bm);
 169
 170         system_bridge_delbr(&bst->dev);
 171
 172         return 0;
 173 }
 174
 175 static int
 176 bridge_set_up(struct bridge_state *bst)
 177 {
 178         struct bridge_member *bm;
 179         int ret;
 180
 181         if (!bst->n_present)
 182                 return -ENOENT;
 183
 184         ret = system_bridge_addbr(&bst->dev, &bst->config);
 185         if (ret < 0)
 186                 goto out;
 187
 188         list_for_each_entry(bm, &bst->members, list)
 189                 bridge_enable_member(bm);
 190
 191         if (!bst->n_present) {
 192                 /* initialization of all member interfaces failed */
 193                 system_bridge_delbr(&bst->dev);
 194                 device_set_present(&bst->dev, false);
 195                 return -ENOENT;
 196         }
 197
 198         ret = bst->set_state(&bst->dev, true);
 199         if (ret < 0)
 200                 bridge_set_down(bst);
 201
 202 out:
 203         return ret;
 204 }
 205
 206 static int
 207 bridge_set_state(struct device *dev, bool up)
 208 {
 209         struct bridge_state *bst;
 210
 211         bst = container_of(dev, struct bridge_state, dev);
 212
 213         if (up)
 214                 return bridge_set_up(bst);
 215         else
 216                 return bridge_set_down(bst);
 217 }
 218
 219 static struct bridge_member *
 220 bridge_create_member(struct bridge_state *bst, struct device *dev, bool hotplug)
 221 {
 222         struct bridge_member *bm;
 223
 224         bm = calloc(1, sizeof(*bm));
 225         bm->bst = bst;
 226         bm->dev.cb = bridge_member_cb;
 227         device_add_user(&bm->dev, dev);
 228         bm->dev.hotplug = hotplug;
 229
 230         list_add_tail(&bm->list, &bst->members);
 231
 232         if (bst->dev.active)
 233                 bridge_enable_member(bm);
 234
 235         return bm;
 236 }
 237
 238 static void
 239 bridge_free_member(struct bridge_member *bm)
 240 {
 241         if (bm->present) {
 242                 bridge_member_cb(&bm->dev, DEV_EVENT_REMOVE);
 243                 bm->bst->n_present--;
 244                 if (bm->bst->dev.active)
 245                         bridge_disable_member(bm);
 246         }
 247
 248         list_del(&bm->list);
 249         device_remove_user(&bm->dev);
 250         free(bm);
 251 }
 252
 253 static void
 254 bridge_add_member(struct bridge_state *bst, const char *name)
 255 {
 256         struct device *dev;
 257
 258         dev = device_get(name, true);
 259         if (!dev)
 260                 return;
 261
 262         bridge_create_member(bst, dev, false);
 263 }
 264
 265 static int
 266 bridge_hotplug_add(struct device *dev, struct device *member)
 267 {
 268         struct bridge_state *bst = container_of(dev, struct bridge_state, dev);
 269
 270         bridge_create_member(bst, member, true);
 271
 272         return 0;
 273 }
 274
 275 static int
 276 bridge_hotplug_del(struct device *dev, struct device *member)
 277 {
 278         struct bridge_state *bst = container_of(dev, struct bridge_state, dev);
 279         struct bridge_member *bm;
 280
 281         list_for_each_entry(bm, &bst->members, list) {
 282                 if (bm->dev.dev != member)
 283                         continue;
 284
 285                 bridge_free_member(bm);
 286                 return 0;
 287         }
 288
 289         return -ENOENT;
 290 }
 291
 292 static const struct device_hotplug_ops bridge_ops = {
 293         .add = bridge_hotplug_add,
 294         .del = bridge_hotplug_del
 295 };
 296
 297 static void
 298 bridge_free(struct device *dev)
 299 {
 300         struct bridge_state *bst;
 301         struct bridge_member *bm;
 302
 303         device_cleanup(dev);
 304         bst = container_of(dev, struct bridge_state, dev);
 305         while (!list_empty(&bst->members)) {
 306                 bm = list_first_entry(&bst->members, struct bridge_member, list);
 307                 bridge_free_member(bm);
 308         }
 309         free(bst);
 310 }
 311
 312 static void
 313 bridge_dump_info(struct device *dev, struct blob_buf *b)
 314 {
 315         struct bridge_state *bst;
 316         struct bridge_member *bm;
 317         void *list;
 318
 319         bst = container_of(dev, struct bridge_state, dev);
 320
 321         list = blobmsg_open_array(b, "bridge-members");
 322         list_for_each_entry(bm, &bst->members, list) {
 323                 blobmsg_add_string(b, NULL, bm->dev.dev->ifname);
 324         }
 325         blobmsg_close_array(b, list);
 326 }
 327
 328 static void
 329 bridge_config_init(struct device *dev)
 330 {
 331         struct bridge_state *bst;
 332         struct blob_attr *cur;
 333         int rem;
 334
 335         bst = container_of(dev, struct bridge_state, dev);
 336         blobmsg_for_each_attr(cur, bst->ifnames, rem) {
 337                 bridge_add_member(bst, blobmsg_data(cur));
 338         }
 339 }
 340
 341 static void
 342 bridge_apply_settings(struct bridge_state *bst, struct blob_attr **tb)
 343 {
 344         struct bridge_config *cfg = &bst->config;
 345         struct blob_attr *cur;
 346
 347         /* defaults */
 348         cfg->stp = true;
 349         cfg->forward_delay = 1;
 350         cfg->igmp_snoop = true;
 351
 352         if ((cur = tb[BRIDGE_ATTR_STP]))
 353                 cfg->stp = blobmsg_get_bool(cur);
 354
 355         if ((cur = tb[BRIDGE_ATTR_FORWARD_DELAY]))
 356                 cfg->forward_delay = blobmsg_get_u32(cur);
 357
 358         if ((cur = tb[BRIDGE_ATTR_IGMP_SNOOP]))
 359                 cfg->igmp_snoop = blobmsg_get_bool(cur);
 360
 361         if ((cur = tb[BRIDGE_ATTR_AGEING_TIME])) {
 362                 cfg->ageing_time = blobmsg_get_u32(cur);
 363                 cfg->flags |= BRIDGE_OPT_AGEING_TIME;
 364         }
 365
 366         if ((cur = tb[BRIDGE_ATTR_HELLO_TIME])) {
 367                 cfg->hello_time = blobmsg_get_u32(cur);
 368                 cfg->flags |= BRIDGE_OPT_HELLO_TIME;
 369         }
 370
 371         if ((cur = tb[BRIDGE_ATTR_MAX_AGE])) {
 372                 cfg->max_age = blobmsg_get_u32(cur);
 373                 cfg->flags |= BRIDGE_OPT_MAX_AGE;
 374         }
 375 }
 376
 377 static struct device *
 378 bridge_create(const char *name, struct blob_attr *attr)
 379 {
 380         struct blob_attr *tb_dev[__DEV_ATTR_MAX];
 381         struct blob_attr *tb_br[__BRIDGE_ATTR_MAX];
 382         struct bridge_state *bst;
 383         struct device *dev = NULL;
 384
 385         blobmsg_parse(device_attr_list.params, __DEV_ATTR_MAX, tb_dev,
 386                 blob_data(attr), blob_len(attr));
 387         blobmsg_parse(bridge_attrs, __BRIDGE_ATTR_MAX, tb_br,
 388                 blob_data(attr), blob_len(attr));
 389
 390         if (!tb_br[BRIDGE_ATTR_IFNAME])
 391                 return NULL;
 392
 393         bst = calloc(1, sizeof(*bst));
 394         if (!bst)
 395                 return NULL;
 396
 397         dev = &bst->dev;
 398         device_init(dev, &bridge_device_type, name);
 399         device_init_settings(dev, tb_dev);
 400         dev->config_pending = true;
 401         bst->ifnames = tb_br[BRIDGE_ATTR_IFNAME];
 402         bridge_apply_settings(bst, tb_br);
 403
 404         bst->set_state = dev->set_state;
 405         dev->set_state = bridge_set_state;
 406
 407         dev->hotplug_ops = &bridge_ops;
 408
 409         INIT_LIST_HEAD(&bst->members);
 410
 411         return dev;
 412 }
 413
 414