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 const struct device_type alias_device_type;
  34
  35 static void alias_set_device(struct alias_device *alias, struct device *dev)
  36 {
  37         if (dev == alias->dep.dev) {
  38                 if (alias->update) {
  39                         device_remove_user(&alias->new_dep);
  40                         alias->update = false;
  41                         if (dev)
  42                                 device_set_present(&alias->dev, true);
  43                 }
  44                 return;
  45         }
  46
  47         device_set_present(&alias->dev, false);
  48         device_remove_user(&alias->new_dep);
  49         if (alias->dev.active) {
  50                 if (dev)
  51                         device_add_user(&alias->new_dep, dev);
  52
  53                 alias->update = true;
  54                 return;
  55         }
  56
  57         alias->update = false;
  58         device_remove_user(&alias->dep);
  59         alias->dev.hidden = !dev;
  60         if (dev) {
  61                 device_set_ifindex(&alias->dev, dev->ifindex);
  62                 device_set_ifname(&alias->dev, dev->ifname);
  63                 device_add_user(&alias->dep, dev);
  64         } else {
  65                 device_set_ifname(&alias->dev, "");
  66                 device_set_link(&alias->dev, false);
  67         }
  68 }
  69
  70 static int
  71 alias_device_set_state(struct device *dev, bool state)
  72 {
  73         struct alias_device *alias;
  74
  75         alias = container_of(dev, struct alias_device, dev);
  76         if (!alias->dep.dev)
  77                 return -1;
  78
  79         if (state)
  80                 return device_claim(&alias->dep);
  81
  82         device_release(&alias->dep);
  83         if (alias->update)
  84                 alias_set_device(alias, alias->new_dep.dev);
  85
  86         return 0;
  87 }
  88
  89 static void alias_device_cb(struct device_user *dep, enum device_event ev)
  90 {
  91         struct alias_device *alias;
  92         bool new_state = false;
  93
  94         alias = container_of(dep, struct alias_device, dep);
  95         switch (ev) {
  96         case DEV_EVENT_ADD:
  97                 new_state = true;
  98         case DEV_EVENT_REMOVE:
  99                 device_set_present(&alias->dev, new_state);
 100                 break;
 101         case DEV_EVENT_LINK_UP:
 102                 new_state = true;
 103         case DEV_EVENT_LINK_DOWN:
 104                 device_set_link(&alias->dev, new_state);
 105                 break;
 106         case DEV_EVENT_UPDATE_IFINDEX:
 107                 device_set_ifindex(&alias->dev, dep->dev->ifindex);
 108                 break;
 109         default:
 110                 device_broadcast_event(&alias->dev, ev);
 111                 break;
 112         }
 113 }
 114
 115 static struct device *
 116 alias_device_create(const char *name, struct blob_attr *attr)
 117 {
 118         struct alias_device *alias;
 119
 120         alias = calloc(1, sizeof(*alias) + strlen(name) + 1);
 121         if (!alias)
 122                 return NULL;
 123
 124         strcpy(alias->name, name);
 125         alias->dev.set_state = alias_device_set_state;
 126         alias->dev.hidden = true;
 127         device_init_virtual(&alias->dev, &alias_device_type, NULL);
 128         alias->avl.key = alias->name;
 129         avl_insert(&aliases, &alias->avl);
 130         alias->dep.alias = true;
 131         alias->dep.cb = alias_device_cb;
 132         device_check_state(&alias->dev);
 133
 134         return &alias->dev;
 135 }
 136
 137 static void alias_device_free(struct device *dev)
 138 {
 139         struct alias_device *alias;
 140
 141         alias = container_of(dev, struct alias_device, dev);
 142         device_remove_user(&alias->new_dep);
 143         device_remove_user(&alias->dep);
 144         avl_delete(&aliases, &alias->avl);
 145         free(alias);
 146 }
 147
 148 static int alias_check_state(struct device *dev)
 149 {
 150         struct alias_device *alias;
 151         struct interface *iface;
 152         struct device *ndev = NULL;
 153
 154         alias = container_of(dev, struct alias_device, dev);
 155
 156         iface = vlist_find(&interfaces, alias->name, iface, node);
 157         if (iface && iface->state == IFS_UP)
 158                 ndev = iface->l3_dev.dev;
 159
 160         alias_set_device(alias, ndev);
 161
 162         return 0;
 163 }
 164
 165 static const struct device_type alias_device_type = {
 166         .name = "Network alias",
 167         .create = alias_device_create,
 168         .free = alias_device_free,
 169         .check_state = alias_check_state,
 170 };
 171
 172 void
 173 alias_notify_device(const char *name, struct device *dev)
 174 {
 175         struct alias_device *alias;
 176
 177         device_lock();
 178
 179         alias = avl_find_element(&aliases, name, alias, avl);
 180         if (alias)
 181                 alias_set_device(alias, dev);
 182
 183         device_unlock();
 184 }
 185
 186 struct device *
 187 device_alias_get(const char *name)
 188 {
 189         struct alias_device *alias;
 190
 191         alias = avl_find_element(&aliases, name, alias, avl);
 192         if (alias)
 193                 return &alias->dev;
 194
 195         return alias_device_create(name, NULL);
 196 }
 197
 198 static void __init alias_init(void)
 199 {
 200         avl_init(&aliases, avl_strcmp, false, NULL);
 201 }