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_MAX
  16 };
  17
  18 static const struct blobmsg_policy bridge_attrs[__BRIDGE_ATTR_MAX] = {
  19         [BRIDGE_ATTR_IFNAME] = { "ifname", BLOBMSG_TYPE_ARRAY },
  20         [BRIDGE_ATTR_STP] = { "stp", BLOBMSG_TYPE_BOOL },
  21 };
  22
  23 static const union config_param_info bridge_attr_info[__BRIDGE_ATTR_MAX] = {
  24         [BRIDGE_ATTR_IFNAME] = { .type = BLOBMSG_TYPE_STRING },
  25 };
  26
  27 static const struct config_param_list bridge_attr_list = {
  28         .n_params = __BRIDGE_ATTR_MAX,
  29         .params = bridge_attrs,
  30         .info = bridge_attr_info,
  31
  32         .n_next = 1,
  33         .next = { &device_attr_list },
  34 };
  35
  36 static struct device *bridge_create(struct blob_attr *attr);
  37 static void bridge_config_init(struct device *dev);
  38 static void bridge_free(struct device *dev);
  39 static void bridge_dump_status(struct device *dev, struct blob_buf *b);
  40
  41 const struct device_type bridge_device_type = {
  42         .name = "Bridge",
  43         .config_params = &bridge_attr_list,
  44
  45         .create = bridge_create,
  46         .config_init = bridge_config_init,
  47         .free = bridge_free,
  48         .dump_status = bridge_dump_status,
  49 };
  50
  51 struct bridge_state {
  52         struct device dev;
  53         device_state_cb set_state;
  54
  55         struct blob_attr *ifnames;
  56         bool active;
  57
  58         struct list_head members;
  59         int n_present;
  60 };
  61
  62 struct bridge_member {
  63         struct list_head list;
  64         struct bridge_state *bst;
  65         struct device_user dev;
  66         bool present;
  67 };
  68
  69 static int
  70 bridge_disable_member(struct bridge_member *bm)
  71 {
  72         struct bridge_state *bst = bm->bst;
  73
  74         if (!bm->present)
  75                 return 0;
  76
  77         system_bridge_delif(&bst->dev, bm->dev.dev);
  78         device_release(&bm->dev);
  79
  80         return 0;
  81 }
  82
  83 static int
  84 bridge_enable_member(struct bridge_member *bm)
  85 {
  86         struct bridge_state *bst = bm->bst;
  87         int ret;
  88
  89         if (!bm->present)
  90                 return 0;
  91
  92         ret = device_claim(&bm->dev);
  93         if (ret < 0)
  94                 goto error;
  95
  96         ret = system_bridge_addif(&bst->dev, bm->dev.dev);
  97         if (ret < 0)
  98                 goto error;
  99
 100         return 0;
 101
 102 error:
 103         bm->present = false;
 104         bst->n_present--;
 105         return ret;
 106 }
 107
 108 static void
 109 bridge_member_cb(struct device_user *dev, enum device_event ev)
 110 {
 111         struct bridge_member *bm = container_of(dev, struct bridge_member, dev);
 112         struct bridge_state *bst = bm->bst;
 113
 114         switch (ev) {
 115         case DEV_EVENT_ADD:
 116                 assert(!bm->present);
 117
 118                 bm->present = true;
 119                 bst->n_present++;
 120
 121                 if (bst->dev.active)
 122                         bridge_enable_member(bm);
 123                 else if (bst->n_present == 1)
 124                         device_set_present(&bst->dev, true);
 125
 126                 break;
 127         case DEV_EVENT_REMOVE:
 128                 if (!bm->present)
 129                         return;
 130
 131                 if (bst->dev.active)
 132                         bridge_disable_member(bm);
 133
 134                 bm->present = false;
 135                 bm->bst->n_present--;
 136                 if (bst->n_present == 0)
 137                         device_set_present(&bst->dev, false);
 138
 139                 break;
 140         default:
 141                 return;
 142         }
 143 }
 144
 145 static int
 146 bridge_set_down(struct bridge_state *bst)
 147 {
 148         struct bridge_member *bm;
 149
 150         bst->set_state(&bst->dev, false);
 151
 152         list_for_each_entry(bm, &bst->members, list)
 153                 bridge_disable_member(bm);
 154
 155         system_bridge_delbr(&bst->dev);
 156
 157         return 0;
 158 }
 159
 160 static int
 161 bridge_set_up(struct bridge_state *bst)
 162 {
 163         struct bridge_member *bm;
 164         int ret;
 165
 166         if (!bst->n_present)
 167                 return -ENOENT;
 168
 169         ret = system_bridge_addbr(&bst->dev);
 170         if (ret < 0)
 171                 goto out;
 172
 173         list_for_each_entry(bm, &bst->members, list)
 174                 bridge_enable_member(bm);
 175
 176         if (!bst->n_present) {
 177                 /* initialization of all member interfaces failed */
 178                 system_bridge_delbr(&bst->dev);
 179                 device_set_present(&bst->dev, false);
 180                 return -ENOENT;
 181         }
 182
 183         ret = bst->set_state(&bst->dev, true);
 184         if (ret < 0)
 185                 bridge_set_down(bst);
 186
 187 out:
 188         return ret;
 189 }
 190
 191 static int
 192 bridge_set_state(struct device *dev, bool up)
 193 {
 194         struct bridge_state *bst;
 195
 196         bst = container_of(dev, struct bridge_state, dev);
 197
 198         if (up)
 199                 return bridge_set_up(bst);
 200         else
 201                 return bridge_set_down(bst);
 202 }
 203
 204 static struct bridge_member *
 205 bridge_create_member(struct bridge_state *bst, struct device *dev)
 206 {
 207         struct bridge_member *bm;
 208
 209         bm = calloc(1, sizeof(*bm));
 210         bm->bst = bst;
 211         bm->dev.cb = bridge_member_cb;
 212         device_add_user(&bm->dev, dev);
 213
 214         list_add_tail(&bm->list, &bst->members);
 215
 216         if (bst->dev.active)
 217                 bridge_enable_member(bm);
 218
 219         return bm;
 220 }
 221
 222 static void
 223 bridge_free_member(struct bridge_member *bm)
 224 {
 225         if (bm->present) {
 226                 bridge_member_cb(&bm->dev, DEV_EVENT_REMOVE);
 227                 bm->bst->n_present--;
 228                 if (bm->bst->dev.active)
 229                         bridge_disable_member(bm);
 230         }
 231
 232         list_del(&bm->list);
 233         device_remove_user(&bm->dev);
 234         free(bm);
 235 }
 236
 237 static void
 238 bridge_add_member(struct bridge_state *bst, const char *name)
 239 {
 240         struct device *dev;
 241
 242         dev = device_get(name, true);
 243         if (!dev)
 244                 return;
 245
 246         bridge_create_member(bst, dev);
 247 }
 248
 249 static int
 250 bridge_hotplug_add(struct device *dev, struct device *member)
 251 {
 252         struct bridge_state *bst = container_of(dev, struct bridge_state, dev);
 253
 254         bridge_create_member(bst, member);
 255
 256         return 0;
 257 }
 258
 259 static int
 260 bridge_hotplug_del(struct device *dev, struct device *member)
 261 {
 262         struct bridge_state *bst = container_of(dev, struct bridge_state, dev);
 263         struct bridge_member *bm;
 264
 265         list_for_each_entry(bm, &bst->members, list) {
 266                 if (bm->dev.dev != member)
 267                         continue;
 268
 269                 bridge_free_member(bm);
 270                 return 0;
 271         }
 272
 273         return -ENOENT;
 274 }
 275
 276 static const struct device_hotplug_ops bridge_ops = {
 277         .add = bridge_hotplug_add,
 278         .del = bridge_hotplug_del
 279 };
 280
 281 static void
 282 bridge_free(struct device *dev)
 283 {
 284         struct bridge_state *bst;
 285         struct bridge_member *bm;
 286
 287         device_cleanup(dev);
 288         bst = container_of(dev, struct bridge_state, dev);
 289         while (!list_empty(&bst->members)) {
 290                 bm = list_first_entry(&bst->members, struct bridge_member, list);
 291                 bridge_free_member(bm);
 292         }
 293         free(bst);
 294 }
 295
 296 static void
 297 bridge_dump_status(struct device *dev, struct blob_buf *b)
 298 {
 299         struct bridge_state *bst;
 300         struct bridge_member *bm;
 301         void *list;
 302
 303         bst = container_of(dev, struct bridge_state, dev);
 304
 305         list = blobmsg_open_array(b, "bridge-members");
 306         list_for_each_entry(bm, &bst->members, list) {
 307                 blobmsg_add_string(b, NULL, bm->dev.dev->ifname);
 308         }
 309         blobmsg_close_array(b, list);
 310 }
 311
 312 static void
 313 bridge_config_init(struct device *dev)
 314 {
 315         struct bridge_state *bst;
 316         struct blob_attr *cur;
 317         int rem;
 318
 319         bst = container_of(dev, struct bridge_state, dev);
 320         blobmsg_for_each_attr(cur, bst->ifnames, rem) {
 321                 bridge_add_member(bst, blobmsg_data(cur));
 322         }
 323 }
 324
 325 static struct device *
 326 bridge_create(struct blob_attr *attr)
 327 {
 328         struct blob_attr *tb_dev[__DEV_ATTR_MAX];
 329         struct blob_attr *tb_br[__BRIDGE_ATTR_MAX];
 330         struct bridge_state *bst;
 331         struct device *dev = NULL;
 332         const char *name;
 333
 334         blobmsg_parse(device_attr_list.params, __DEV_ATTR_MAX, tb_dev,
 335                 blob_data(attr), blob_len(attr));
 336         blobmsg_parse(bridge_attrs, __BRIDGE_ATTR_MAX, tb_br,
 337                 blob_data(attr), blob_len(attr));
 338
 339         if (!tb_dev[DEV_ATTR_NAME])
 340                 return NULL;
 341
 342         if (!tb_br[BRIDGE_ATTR_IFNAME])
 343                 return NULL;
 344
 345         name = blobmsg_data(tb_dev[DEV_ATTR_NAME]);
 346
 347         bst = calloc(1, sizeof(*bst));
 348         if (!bst)
 349                 return NULL;
 350
 351         dev = &bst->dev;
 352         device_init(dev, &bridge_device_type, name);
 353         device_init_settings(dev, tb_dev);
 354         dev->config_pending = true;
 355         bst->ifnames = tb_br[BRIDGE_ATTR_IFNAME];
 356
 357         bst->set_state = dev->set_state;
 358         dev->set_state = bridge_set_state;
 359
 360         dev->hotplug_ops = &bridge_ops;
 361
 362         INIT_LIST_HEAD(&bst->members);
 363
 364         return dev;
 365 }
 366
 367