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         bool cleanup;
  29         char name[];
  30 };
  31
  32 static const struct device_type alias_device_type;
  33
  34 static int
  35 alias_device_set_state(struct device *dev, bool state)
  36 {
  37         struct alias_device *alias;
  38
  39         alias = container_of(dev, struct alias_device, dev);
  40         if (!alias->dep.dev)
  41                 return -1;
  42
  43         if (state)
  44                 return device_claim(&alias->dep);
  45
  46         device_release(&alias->dep);
  47         if (alias->cleanup)
  48                 device_remove_user(&alias->dep);
  49         return 0;
  50 }
  51
  52 static void alias_device_cb(struct device_user *dep, enum device_event ev)
  53 {
  54         struct alias_device *alias;
  55         bool present = false;
  56
  57         alias = container_of(dep, struct alias_device, dep);
  58         switch (ev) {
  59         case DEV_EVENT_ADD:
  60                 present = true;
  61         case DEV_EVENT_REMOVE:
  62                 device_set_present(&alias->dev, present);
  63                 break;
  64         default:
  65                 device_broadcast_event(&alias->dev, ev);
  66                 break;
  67         }
  68 }
  69
  70 static struct device *
  71 alias_device_create(const char *name, struct blob_attr *attr)
  72 {
  73         struct alias_device *alias;
  74
  75         alias = calloc(1, sizeof(*alias) + strlen(name) + 1);
  76         strcpy(alias->name, name);
  77         alias->dev.set_state = alias_device_set_state;
  78         alias->dev.hidden = true;
  79         device_init_virtual(&alias->dev, &alias_device_type, NULL);
  80         alias->avl.key = alias->name;
  81         avl_insert(&aliases, &alias->avl);
  82         alias->dep.alias = true;
  83         alias->dep.cb = alias_device_cb;
  84         device_check_state(&alias->dev);
  85
  86         return &alias->dev;
  87 }
  88
  89 static void alias_device_free(struct device *dev)
  90 {
  91         struct alias_device *alias;
  92
  93         alias = container_of(dev, struct alias_device, dev);
  94         avl_delete(&aliases, &alias->avl);
  95         free(alias);
  96 }
  97
  98 static void __alias_notify_device(struct alias_device *alias, struct device *dev)
  99 {
 100         alias->cleanup = !dev;
 101         if (dev) {
 102                 if (dev != alias->dep.dev) {
 103                         device_remove_user(&alias->dep);
 104                         strcpy(alias->dev.ifname, dev->ifname);
 105                         device_add_user(&alias->dep, dev);
 106                         alias->dev.hidden = false;
 107                         device_broadcast_event(&alias->dev, DEV_EVENT_UPDATE_IFNAME);
 108                 }
 109         }
 110
 111         if (!dev && alias->dep.dev && !alias->dep.dev->active) {
 112                 device_remove_user(&alias->dep);
 113                 alias->dev.hidden = true;
 114                 alias->dev.ifname[0] = 0;
 115                 device_broadcast_event(&alias->dev, DEV_EVENT_UPDATE_IFNAME);
 116         }
 117 }
 118
 119 static int alias_check_state(struct device *dev)
 120 {
 121         struct alias_device *alias;
 122         struct interface *iface;
 123         struct device *ndev = NULL;
 124
 125         alias = container_of(dev, struct alias_device, dev);
 126
 127         iface = vlist_find(&interfaces, alias->name, iface, node);
 128         if (iface && iface->state == IFS_UP)
 129                 ndev = iface->main_dev.dev;
 130
 131         __alias_notify_device(alias, ndev);
 132
 133         return 0;
 134 }
 135
 136 static const struct device_type alias_device_type = {
 137         .name = "Network alias",
 138         .create = alias_device_create,
 139         .free = alias_device_free,
 140         .check_state = alias_check_state,
 141 };
 142
 143 void
 144 alias_notify_device(const char *name, struct device *dev)
 145 {
 146         struct alias_device *alias;
 147
 148         device_lock();
 149
 150         alias = avl_find_element(&aliases, name, alias, avl);
 151         if (alias)
 152                 __alias_notify_device(alias, dev);
 153
 154         device_unlock();
 155 }
 156
 157 struct device *
 158 device_alias_get(const char *name)
 159 {
 160         struct alias_device *alias;
 161
 162         alias = avl_find_element(&aliases, name, alias, avl);
 163         if (alias)
 164                 return &alias->dev;
 165
 166         return alias_device_create(name, NULL);
 167 }
 168
 169 static void __init alias_init(void)
 170 {
 171         avl_init(&aliases, avl_strcmp, false, NULL);
 172 }