alias.c

   1 /*
   2  * netifd - network interface daemon
   3  * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14 #include <string.h>
  15 #include <stdlib.h>
  16 #include <stdio.h>
  17
  18 #include "netifd.h"
  19 #include "device.h"
  20 #include "interface.h"
  21
  22 static struct avl_tree aliases;
  23
  24 struct alias_device {
  25         struct avl_node avl;
  26         struct device dev;
  27         struct device_user dep;
  28         struct device_user new_dep;
  29         bool update;
  30         char name[];
  31 };
  32
  33 static void alias_set_device(struct alias_device *alias, struct device *dev)
  34 {
  35         if (dev == alias->dep.dev) {
  36                 if (alias->update) {
  37                         device_remove_user(&alias->new_dep);
  38                         alias->update = false;
  39                         if (dev)
  40                                 device_set_present(&alias->dev, true);
  41                 }
  42                 return;
  43         }
  44
  45         device_set_present(&alias->dev, false);
  46         device_remove_user(&alias->new_dep);
  47         if (alias->dev.active) {
  48                 if (dev)
  49                         device_add_user(&alias->new_dep, dev);
  50
  51                 alias->update = true;
  52                 return;
  53         }
  54
  55         alias->update = false;
  56         device_remove_user(&alias->dep);
  57         alias->dev.hidden = !dev;
  58         if (dev) {
  59                 device_set_ifindex(&alias->dev, dev->ifindex);
  60                 device_set_ifname(&alias->dev, dev->ifname);
  61                 device_add_user(&alias->dep, dev);
  62         } else {
  63                 device_set_ifname(&alias->dev, "");
  64                 device_set_link(&alias->dev, false);
  65         }
  66 }
  67
  68 static int
  69 alias_device_set_state(struct device *dev, bool state)
  70 {
  71         struct alias_device *alias;
  72
  73         alias = container_of(dev, struct alias_device, dev);
  74         if (!alias->dep.dev)
  75                 return -1;
  76
  77         if (state)
  78                 return device_claim(&alias->dep);
  79
  80         device_release(&alias->dep);
  81         if (alias->update)
  82                 alias_set_device(alias, alias->new_dep.dev);
  83
  84         return 0;
  85 }
  86
  87 static void alias_device_cb(struct device_user *dep, enum device_event ev)
  88 {
  89         struct alias_device *alias;
  90         bool new_state = false;
  91
  92         alias = container_of(dep, struct alias_device, dep);
  93         switch (ev) {
  94         case DEV_EVENT_ADD:
  95                 new_state = true;
  96         case DEV_EVENT_REMOVE:
  97                 device_set_present(&alias->dev, new_state);
  98                 break;
  99         case DEV_EVENT_LINK_UP:
 100                 new_state = true;
 101         case DEV_EVENT_LINK_DOWN:
 102                 device_set_link(&alias->dev, new_state);
 103                 break;
 104         case DEV_EVENT_UPDATE_IFINDEX:
 105                 device_set_ifindex(&alias->dev, dep->dev->ifindex);
 106                 break;
 107         default:
 108                 device_broadcast_event(&alias->dev, ev);
 109                 break;
 110         }
 111 }
 112
 113 static struct device *
 114 alias_device_create(const char *name, struct device_type *devtype,
 115                     struct blob_attr *attr)
 116 {
 117         struct alias_device *alias;
 118
 119         alias = calloc(1, sizeof(*alias) + strlen(name) + 1);
 120         if (!alias)
 121                 return NULL;
 122
 123         strcpy(alias->name, name);
 124         alias->dev.set_state = alias_device_set_state;
 125         alias->dev.hidden = true;
 126         device_init_virtual(&alias->dev, devtype, NULL);
 127         alias->avl.key = alias->name;
 128         avl_insert(&aliases, &alias->avl);
 129         alias->dep.alias = true;
 130         alias->dep.cb = alias_device_cb;
 131         device_check_state(&alias->dev);
 132
 133         return &alias->dev;
 134 }
 135
 136 static void alias_device_free(struct device *dev)
 137 {
 138         struct alias_device *alias;
 139
 140         alias = container_of(dev, struct alias_device, dev);
 141         device_remove_user(&alias->new_dep);
 142         device_remove_user(&alias->dep);
 143         avl_delete(&aliases, &alias->avl);
 144         free(alias);
 145 }
 146
 147 static int alias_check_state(struct device *dev)
 148 {
 149         struct alias_device *alias;
 150         struct interface *iface;
 151         struct device *ndev = NULL;
 152
 153         alias = container_of(dev, struct alias_device, dev);
 154
 155         iface = vlist_find(&interfaces, alias->name, iface, node);
 156         if (iface && iface->state == IFS_UP)
 157                 ndev = iface->l3_dev.dev;
 158
 159         alias_set_device(alias, ndev);
 160
 161         return 0;
 162 }
 163
 164 static struct device_type alias_device_type = {
 165         .name = "Network alias",
 166         .create = alias_device_create,
 167         .free = alias_device_free,
 168         .check_state = alias_check_state,
 169 };
 170
 171 void
 172 alias_notify_device(const char *name, struct device *dev)
 173 {
 174         struct alias_device *alias;
 175
 176         device_lock();
 177
 178         alias = avl_find_element(&aliases, name, alias, avl);
 179         if (alias)
 180                 alias_set_device(alias, dev);
 181
 182         device_unlock();
 183 }
 184
 185 struct device *
 186 device_alias_get(const char *name)
 187 {
 188         struct alias_device *alias;
 189
 190         alias = avl_find_element(&aliases, name, alias, avl);
 191         if (alias)
 192                 return &alias->dev;
 193
 194         return alias_device_create(name, &alias_device_type, NULL);
 195 }
 196
 197 static void __init alias_init(void)
 198 {
 199         avl_init(&aliases, avl_strcmp, false, NULL);
 200 }