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