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 #include <unistd.h>
  18
  19 #include <libubox/uloop.h>
  20
  21 #include "netifd.h"
  22 #include "interface.h"
  23 #include "ubus.h"
  24
  25 char *hotplug_cmd_path = DEFAULT_HOTPLUG_PATH;
  26 static struct interface *current;
  27 static enum interface_event current_ev;
  28 static struct list_head pending = LIST_HEAD_INIT(pending);
  29
  30 static void task_complete(struct uloop_process *proc, int ret);
  31 static struct uloop_process task = {
  32         .cb = task_complete,
  33 };
  34
  35 static void
  36 run_cmd(const char *ifname, const char *device, enum interface_event event)
  37 {
  38         char *argv[3];
  39         int pid;
  40
  41         pid = fork();
  42         if (pid < 0)
  43                 return task_complete(NULL, -1);
  44
  45         if (pid > 0) {
  46                 task.pid = pid;
  47                 uloop_process_add(&task);
  48                 return;
  49         }
  50
  51         char *eventnames[] = {"ifdown", "ifup", "ifupdate"};
  52         setenv("ACTION", eventnames[event], 1);
  53         setenv("INTERFACE", ifname, 1);
  54         if (device)
  55                 setenv("DEVICE", device, 1);
  56         argv[0] = hotplug_cmd_path;
  57         argv[1] = "iface";
  58         argv[2] = NULL;
  59         execvp(argv[0], argv);
  60         exit(127);
  61 }
  62
  63 static void
  64 call_hotplug(void)
  65 {
  66         const char *device = NULL;
  67         if (list_empty(&pending))
  68                 return;
  69
  70         current = list_first_entry(&pending, struct interface, hotplug_list);
  71         current_ev = current->hotplug_ev;
  72         list_del_init(&current->hotplug_list);
  73
  74         if (current_ev == IFEV_UP && current->l3_dev.dev)
  75                 device = current->l3_dev.dev->ifname;
  76
  77         D(SYSTEM, "Call hotplug handler for interface '%s' (%s)\n", current->name, device ? device : "none");
  78         run_cmd(current->name, device, current_ev);
  79 }
  80
  81 static void
  82 task_complete(struct uloop_process *proc, int ret)
  83 {
  84         if (current)
  85                 D(SYSTEM, "Complete hotplug handler for interface '%s'\n", current->name);
  86         current = NULL;
  87         call_hotplug();
  88 }
  89
  90 /*
  91  * Queue an interface for an up/down event.
  92  * An interface can only have one event in the queue and one
  93  * event waiting for completion.
  94  * When queueing an event that is the same as the one waiting for
  95  * completion, remove the interface from the queue
  96  */
  97 static void
  98 interface_queue_event(struct interface *iface, enum interface_event ev)
  99 {
 100         enum interface_event last_ev;
 101
 102         D(SYSTEM, "Queue hotplug handler for interface '%s'\n", iface->name);
 103         if (ev == IFEV_UP || ev == IFEV_DOWN)
 104                 netifd_ubus_interface_event(iface, ev == IFEV_UP);
 105
 106         netifd_ubus_interface_notify(iface, ev != IFEV_DOWN);
 107
 108         if (current == iface)
 109                 last_ev = current_ev;
 110         else
 111                 last_ev = iface->hotplug_ev;
 112
 113         iface->hotplug_ev = ev;
 114         if ((last_ev == ev && ev != IFEV_UPDATE) && !list_empty(&iface->hotplug_list))
 115                 list_del_init(&iface->hotplug_list);
 116         else if ((last_ev != ev || ev == IFEV_UPDATE) && list_empty(&iface->hotplug_list))
 117                 list_add(&iface->hotplug_list, &pending);
 118
 119         if (!task.pending && !current)
 120                 call_hotplug();
 121 }
 122
 123 static void
 124 interface_dequeue_event(struct interface *iface)
 125 {
 126         if (iface == current)
 127                 current = NULL;
 128
 129         if (!list_empty(&iface->hotplug_list))
 130                 list_del_init(&iface->hotplug_list);
 131 }
 132
 133 static void interface_event_cb(struct interface_user *dep, struct interface *iface,
 134                                enum interface_event ev)
 135 {
 136         switch (ev) {
 137                 case IFEV_UP:
 138                 case IFEV_UPDATE:
 139                 case IFEV_DOWN:
 140                         interface_queue_event(iface, ev);
 141                         break;
 142                 case IFEV_FREE:
 143                 case IFEV_RELOAD:
 144                         interface_dequeue_event(iface);
 145                         break;
 146         }
 147 }
 148
 149 static struct interface_user event_user = {
 150         .cb = interface_event_cb
 151 };
 152
 153 static void __init interface_event_init(void)
 154 {
 155         interface_add_user(&event_user, NULL);
 156 }