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