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                 alias->dev.ifindex = 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 present = false;
  87
  88         alias = container_of(dep, struct alias_device, dep);
  89         switch (ev) {
  90         case DEV_EVENT_ADD:
  91                 present = true;
  92         case DEV_EVENT_REMOVE:
  93                 device_set_present(&alias->dev, present);
  94                 break;
  95         default:
  96                 device_broadcast_event(&alias->dev, ev);
  97                 break;
  98         }
  99 }
 100
 101 static struct device *
 102 alias_device_create(const char *name, struct blob_attr *attr)
 103 {
 104         struct alias_device *alias;
 105
 106         alias = calloc(1, sizeof(*alias) + strlen(name) + 1);
 107         strcpy(alias->name, name);
 108         alias->dev.set_state = alias_device_set_state;
 109         alias->dev.hidden = true;
 110         device_init_virtual(&alias->dev, &alias_device_type, NULL);
 111         alias->avl.key = alias->name;
 112         avl_insert(&aliases, &alias->avl);
 113         alias->dep.alias = true;
 114         alias->dep.cb = alias_device_cb;
 115         device_check_state(&alias->dev);
 116
 117         return &alias->dev;
 118 }
 119
 120 static void alias_device_free(struct device *dev)
 121 {
 122         struct alias_device *alias;
 123
 124         alias = container_of(dev, struct alias_device, dev);
 125         avl_delete(&aliases, &alias->avl);
 126         free(alias);
 127 }
 128
 129 static int alias_check_state(struct device *dev)
 130 {
 131         struct alias_device *alias;
 132         struct interface *iface;
 133         struct device *ndev = NULL;
 134
 135         alias = container_of(dev, struct alias_device, dev);
 136
 137         iface = vlist_find(&interfaces, alias->name, iface, node);
 138         if (iface && iface->state == IFS_UP)
 139                 ndev = iface->l3_dev.dev;
 140
 141         alias_set_device(alias, ndev);
 142
 143         return 0;
 144 }
 145
 146 static const struct device_type alias_device_type = {
 147         .name = "Network alias",
 148         .create = alias_device_create,
 149         .free = alias_device_free,
 150         .check_state = alias_check_state,
 151 };
 152
 153 void
 154 alias_notify_device(const char *name, struct device *dev)
 155 {
 156         struct alias_device *alias;
 157
 158         device_lock();
 159
 160         alias = avl_find_element(&aliases, name, alias, avl);
 161         if (alias)
 162                 alias_set_device(alias, dev);
 163
 164         device_unlock();
 165 }
 166
 167 struct device *
 168 device_alias_get(const char *name)
 169 {
 170         struct alias_device *alias;
 171
 172         alias = avl_find_element(&aliases, name, alias, avl);
 173         if (alias)
 174                 return &alias->dev;
 175
 176         return alias_device_create(name, NULL);
 177 }
 178
 179 static void __init alias_init(void)
 180 {
 181         avl_init(&aliases, avl_strcmp, false, NULL);
 182 }