interface-event.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 <stdio.h>
  15 #include <stdlib.h>
  16 #include <string.h>
  17
  18 #include <libubox/uloop.h>
  19
  20 #include "netifd.h"
  21 #include "interface.h"
  22 #include "ubus.h"
  23
  24 char *hotplug_cmd_path = DEFAULT_HOTPLUG_PATH;
  25 static struct interface *current;
  26 static enum interface_event current_ev;
  27 static struct list_head pending = LIST_HEAD_INIT(pending);
  28
  29 static void task_complete(struct uloop_process *proc, int ret);
  30 static struct uloop_process task = {
  31         .cb = task_complete,
  32 };
  33
  34 static void
  35 run_cmd(const char *ifname, const char *device, enum interface_event event)
  36 {
  37         char *argv[3];
  38         int pid;
  39
  40         pid = fork();
  41         if (pid < 0)
  42                 return task_complete(NULL, -1);
  43
  44         if (pid > 0) {
  45                 task.pid = pid;
  46                 uloop_process_add(&task);
  47                 return;
  48         }
  49
  50         char *eventnames[] = {"ifdown", "ifup", "ifupdate"};
  51         setenv("ACTION", eventnames[event], 1);
  52         setenv("INTERFACE", ifname, 1);
  53         if (device)
  54                 setenv("DEVICE", device, 1);
  55         argv[0] = hotplug_cmd_path;
  56         argv[1] = "iface";
  57         argv[2] = NULL;
  58         execvp(argv[0], argv);
  59         exit(127);
  60 }
  61
  62 static void
  63 call_hotplug(void)
  64 {
  65         const char *device = NULL;
  66         if (list_empty(&pending))
  67                 return;
  68
  69         current = list_first_entry(&pending, struct interface, hotplug_list);
  70         current_ev = current->hotplug_ev;
  71         list_del_init(&current->hotplug_list);
  72
  73         if (current_ev == IFEV_UP && current->l3_dev.dev)
  74                 device = current->l3_dev.dev->ifname;
  75
  76         D(SYSTEM, "Call hotplug handler for interface '%s' (%s)\n", current->name, device ? device : "none");
  77         run_cmd(current->name, device, current_ev);
  78 }
  79
  80 static void
  81 task_complete(struct uloop_process *proc, int ret)
  82 {
  83         if (current)
  84                 D(SYSTEM, "Complete hotplug handler for interface '%s'\n", current->name);
  85         current = NULL;
  86         call_hotplug();
  87 }
  88
  89 /*
  90  * Queue an interface for an up/down event.
  91  * An interface can only have one event in the queue and one
  92  * event waiting for completion.
  93  * When queueing an event that is the same as the one waiting for
  94  * completion, remove the interface from the queue
  95  */
  96 static void
  97 interface_queue_event(struct interface *iface, enum interface_event ev)
  98 {
  99         enum interface_event last_ev;
 100
 101         D(SYSTEM, "Queue hotplug handler for interface '%s'\n", iface->name);
 102         if (ev == IFEV_UP || ev == IFEV_DOWN)
 103                 netifd_ubus_interface_event(iface, ev == IFEV_UP);
 104
 105         netifd_ubus_interface_notify(iface, ev != IFEV_DOWN);
 106
 107         if (current == iface)
 108                 last_ev = current_ev;
 109         else
 110                 last_ev = iface->hotplug_ev;
 111
 112         iface->hotplug_ev = ev;
 113         if ((last_ev == ev && ev != IFEV_UPDATE) && !list_empty(&iface->hotplug_list))
 114                 list_del_init(&iface->hotplug_list);
 115         else if ((last_ev != ev || ev == IFEV_UPDATE) && list_empty(&iface->hotplug_list))
 116                 list_add(&iface->hotplug_list, &pending);
 117
 118         if (!task.pending && !current)
 119                 call_hotplug();
 120 }
 121
 122 static void
 123 interface_dequeue_event(struct interface *iface)
 124 {
 125         if (iface == current)
 126                 current = NULL;
 127
 128         if (!list_empty(&iface->hotplug_list))
 129                 list_del_init(&iface->hotplug_list);
 130 }
 131
 132 static void interface_event_cb(struct interface_user *dep, struct interface *iface,
 133                                enum interface_event ev)
 134 {
 135         switch (ev) {
 136                 case IFEV_UP:
 137                 case IFEV_UPDATE:
 138                 case IFEV_DOWN:
 139                         interface_queue_event(iface, ev);
 140                         break;
 141                 case IFEV_FREE:
 142                 case IFEV_RELOAD:
 143                         interface_dequeue_event(iface);
 144                         break;
 145         }
 146 }
 147
 148 static struct interface_user event_user = {
 149         .cb = interface_event_cb
 150 };
 151
 152 static void __init interface_event_init(void)
 153 {
 154         interface_add_user(&event_user, NULL);
 155 }