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                 enum interface_update_flags updated)
  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
  57         if (event == IFEV_UPDATE) {
  58                 if (updated & IUF_ADDRESS)
  59                         setenv("IFUPDATE_ADDRESSES", "1", 1);
  60                 if (updated & IUF_ROUTE)
  61                         setenv("IFUPDATE_ROUTES", "1", 1);
  62                 if (updated & IUF_PREFIX)
  63                         setenv("IFUPDATE_PREFIXES", "1", 1);
  64                 if (updated & IUF_DATA)
  65                         setenv("IFUPDATE_DATA", "1", 1);
  66         }
  67
  68         argv[0] = hotplug_cmd_path;
  69         argv[1] = "iface";
  70         argv[2] = NULL;
  71         execvp(argv[0], argv);
  72         exit(127);
  73 }
  74
  75 static void
  76 call_hotplug(void)
  77 {
  78         const char *device = NULL;
  79         if (list_empty(&pending))
  80                 return;
  81
  82         current = list_first_entry(&pending, struct interface, hotplug_list);
  83         current_ev = current->hotplug_ev;
  84         list_del_init(&current->hotplug_list);
  85
  86         if (current_ev == IFEV_UP && current->l3_dev.dev)
  87                 device = current->l3_dev.dev->ifname;
  88
  89         D(SYSTEM, "Call hotplug handler for interface '%s' (%s)\n", current->name, device ? device : "none");
  90         run_cmd(current->name, device, current_ev, current->updated);
  91 }
  92
  93 static void
  94 task_complete(struct uloop_process *proc, int ret)
  95 {
  96         if (current)
  97                 D(SYSTEM, "Complete hotplug handler for interface '%s'\n", current->name);
  98         current = NULL;
  99         call_hotplug();
 100 }
 101
 102 /*
 103  * Queue an interface for an up/down event.
 104  * An interface can only have one event in the queue and one
 105  * event waiting for completion.
 106  * When queueing an event that is the same as the one waiting for
 107  * completion, remove the interface from the queue
 108  */
 109 static void
 110 interface_queue_event(struct interface *iface, enum interface_event ev)
 111 {
 112         enum interface_event last_ev;
 113
 114         D(SYSTEM, "Queue hotplug handler for interface '%s'\n", iface->name);
 115         if (ev == IFEV_UP || ev == IFEV_DOWN)
 116                 netifd_ubus_interface_event(iface, ev == IFEV_UP);
 117
 118         netifd_ubus_interface_notify(iface, ev != IFEV_DOWN);
 119
 120         if (current == iface)
 121                 last_ev = current_ev;
 122         else
 123                 last_ev = iface->hotplug_ev;
 124
 125         iface->hotplug_ev = ev;
 126         if ((last_ev == ev && ev != IFEV_UPDATE) && !list_empty(&iface->hotplug_list))
 127                 list_del_init(&iface->hotplug_list);
 128         else if ((last_ev != ev || ev == IFEV_UPDATE) && list_empty(&iface->hotplug_list))
 129                 list_add(&iface->hotplug_list, &pending);
 130
 131         if (!task.pending && !current)
 132                 call_hotplug();
 133 }
 134
 135 static void
 136 interface_dequeue_event(struct interface *iface)
 137 {
 138         if (iface == current)
 139                 current = NULL;
 140
 141         if (!list_empty(&iface->hotplug_list))
 142                 list_del_init(&iface->hotplug_list);
 143 }
 144
 145 static void interface_event_cb(struct interface_user *dep, struct interface *iface,
 146                                enum interface_event ev)
 147 {
 148         switch (ev) {
 149                 case IFEV_UP:
 150                 case IFEV_UPDATE:
 151                 case IFEV_DOWN:
 152                         interface_queue_event(iface, ev);
 153                         break;
 154                 case IFEV_FREE:
 155                 case IFEV_RELOAD:
 156                         interface_dequeue_event(iface);
 157                         break;
 158         }
 159 }
 160
 161 static struct interface_user event_user = {
 162         .cb = interface_event_cb
 163 };
 164
 165 static void __init interface_event_init(void)
 166 {
 167         interface_add_user(&event_user, NULL);
 168 }