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 }
  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 blob_attr *attr)
 115 {
 116         struct alias_device *alias;
 117
 118         alias = calloc(1, sizeof(*alias) + strlen(name) + 1);
 119         if (!alias)
 120                 return NULL;
 121
 122         strcpy(alias->name, name);
 123         alias->dev.set_state = alias_device_set_state;
 124         alias->dev.hidden = true;
 125         device_init_virtual(&alias->dev, &alias_device_type, NULL);
 126         alias->avl.key = alias->name;
 127         avl_insert(&aliases, &alias->avl);
 128         alias->dep.alias = true;
 129         alias->dep.cb = alias_device_cb;
 130         device_check_state(&alias->dev);
 131
 132         return &alias->dev;
 133 }
 134
 135 static void alias_device_free(struct device *dev)
 136 {
 137         struct alias_device *alias;
 138
 139         alias = container_of(dev, struct alias_device, dev);
 140         device_remove_user(&alias->new_dep);
 141         device_remove_user(&alias->dep);
 142         avl_delete(&aliases, &alias->avl);
 143         free(alias);
 144 }
 145
 146 static int alias_check_state(struct device *dev)
 147 {
 148         struct alias_device *alias;
 149         struct interface *iface;
 150         struct device *ndev = NULL;
 151
 152         alias = container_of(dev, struct alias_device, dev);
 153
 154         iface = vlist_find(&interfaces, alias->name, iface, node);
 155         if (iface && iface->state == IFS_UP)
 156                 ndev = iface->l3_dev.dev;
 157
 158         alias_set_device(alias, ndev);
 159
 160         return 0;
 161 }
 162
 163 static const struct device_type alias_device_type = {
 164         .name = "Network alias",
 165         .create = alias_device_create,
 166         .free = alias_device_free,
 167         .check_state = alias_check_state,
 168 };
 169
 170 void
 171 alias_notify_device(const char *name, struct device *dev)
 172 {
 173         struct alias_device *alias;
 174
 175         device_lock();
 176
 177         alias = avl_find_element(&aliases, name, alias, avl);
 178         if (alias)
 179                 alias_set_device(alias, dev);
 180
 181         device_unlock();
 182 }
 183
 184 struct device *
 185 device_alias_get(const char *name)
 186 {
 187         struct alias_device *alias;
 188
 189         alias = avl_find_element(&aliases, name, alias, avl);
 190         if (alias)
 191                 return &alias->dev;
 192
 193         return alias_device_create(name, NULL);
 194 }
 195
 196 static void __init alias_init(void)
 197 {
 198         avl_init(&aliases, avl_strcmp, false, NULL);
 199 }