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 static const char * const eventnames[] = {
  34         [IFEV_DOWN] = "ifdown",
  35         [IFEV_UP] = "ifup",
  36         [IFEV_UP_FAILED] = "ifup-failed",
  37         [IFEV_UPDATE] = "ifupdate",
  38         [IFEV_FREE] = "free",
  39         [IFEV_RELOAD] = "reload",
  40         [IFEV_LINK_UP] = "iflink",
  41 };
  42
  43 static void
  44 run_cmd(const char *ifname, const char *device, enum interface_event event,
  45                 enum interface_update_flags updated)
  46 {
  47         char *argv[3];
  48         int pid;
  49
  50         pid = fork();
  51         if (pid < 0)
  52                 return task_complete(NULL, -1);
  53
  54         if (pid > 0) {
  55                 task.pid = pid;
  56                 uloop_process_add(&task);
  57                 return;
  58         }
  59
  60         setenv("ACTION", eventnames[event], 1);
  61         setenv("INTERFACE", ifname, 1);
  62         if (device)
  63                 setenv("DEVICE", device, 1);
  64
  65         if (event == IFEV_UPDATE) {
  66                 if (updated & IUF_ADDRESS)
  67                         setenv("IFUPDATE_ADDRESSES", "1", 1);
  68                 if (updated & IUF_ROUTE)
  69                         setenv("IFUPDATE_ROUTES", "1", 1);
  70                 if (updated & IUF_PREFIX)
  71                         setenv("IFUPDATE_PREFIXES", "1", 1);
  72                 if (updated & IUF_DATA)
  73                         setenv("IFUPDATE_DATA", "1", 1);
  74         }
  75
  76         argv[0] = hotplug_cmd_path;
  77         argv[1] = "iface";
  78         argv[2] = NULL;
  79         execvp(argv[0], argv);
  80         exit(127);
  81 }
  82
  83 static void
  84 call_hotplug(void)
  85 {
  86         const char *device = NULL;
  87         if (list_empty(&pending))
  88                 return;
  89
  90         current = list_first_entry(&pending, struct interface, hotplug_list);
  91         current_ev = current->hotplug_ev;
  92         list_del_init(&current->hotplug_list);
  93
  94         if ((current_ev == IFEV_UP || current_ev == IFEV_UPDATE) && current->l3_dev.dev)
  95                 device = current->l3_dev.dev->ifname;
  96
  97         D(SYSTEM, "Call hotplug handler for interface '%s', event '%s' (%s)\n",
  98         current->name, eventnames[current_ev], device ? device : "none");
  99         run_cmd(current->name, device, current_ev, current->updated);
 100 }
 101
 102 static void
 103 task_complete(struct uloop_process *proc, int ret)
 104 {
 105         if (current)
 106                 D(SYSTEM, "Complete hotplug handler for interface '%s'\n", current->name);
 107         current = NULL;
 108         call_hotplug();
 109 }
 110
 111 /*
 112  * Queue an interface for an up/down event.
 113  * An interface can only have one event in the queue and one
 114  * event waiting for completion.
 115  * When queueing an event that is the same as the one waiting for
 116  * completion, remove the interface from the queue
 117  */
 118 static void
 119 interface_queue_event(struct interface *iface, enum interface_event ev)
 120 {
 121         D(SYSTEM, "Queue hotplug handler for interface '%s', event '%s'\n",
 122                         iface->name, eventnames[ev]);
 123         if (ev == IFEV_UP || ev == IFEV_DOWN)
 124                 netifd_ubus_interface_event(iface, ev == IFEV_UP);
 125
 126         netifd_ubus_interface_notify(iface, ev != IFEV_DOWN);
 127
 128         /* no hotplug.d calls for link up */
 129         if (ev == IFEV_LINK_UP)
 130                 return;
 131
 132         if (current == iface) {
 133                 /* an event for iface is being processed */
 134                 if (!list_empty(&iface->hotplug_list)) {
 135                         /* an additional event for iface is pending   */
 136                         /* overwrite pending event if it differs from */
 137                         /* an update                                  */
 138                         if (ev != IFEV_UPDATE)
 139                                 iface->hotplug_ev = ev;
 140                 }
 141                 else {
 142                         /* no additional event for iface is pending */
 143                         if (ev != current_ev || ev == IFEV_UPDATE) {
 144                                 /* only add the interface to the pending list if
 145                                  * the event is different from the one being
 146                                  * handled or if it is an update */
 147                                 iface->hotplug_ev = ev;
 148                                 /* Handle hotplug calls FIFO */
 149                                 list_add_tail(&iface->hotplug_list, &pending);
 150                         }
 151                 }
 152         }
 153         else {
 154                 /* currently not handling an event or handling an event
 155                  * for another interface */
 156                 if (!list_empty(&iface->hotplug_list)) {
 157                         /* an event for iface is pending */
 158                         if (!(iface->hotplug_ev == IFEV_UP &&
 159                                 ev == IFEV_UPDATE)) {
 160                                 /* overwrite pending event, unless the incoming
 161                                  * event is an ifupdate while the pending one
 162                                  * is an ifup */
 163                                 iface->hotplug_ev = ev;
 164                         }
 165                 }
 166                 else {
 167                         /* an event for the interface is not yet pending,
 168                          * queue it */
 169                         iface->hotplug_ev = ev;
 170                         /* Handle hotplug calls FIFO */
 171                         list_add_tail(&iface->hotplug_list, &pending);
 172                 }
 173         }
 174
 175         if (!task.pending && !current)
 176                 call_hotplug();
 177 }
 178
 179 static void
 180 interface_dequeue_event(struct interface *iface)
 181 {
 182         if (iface == current)
 183                 current = NULL;
 184
 185         if (!list_empty(&iface->hotplug_list))
 186                 list_del_init(&iface->hotplug_list);
 187 }
 188
 189 static void interface_event_cb(struct interface_user *dep, struct interface *iface,
 190                                enum interface_event ev)
 191 {
 192         switch (ev) {
 193                 case IFEV_LINK_UP:
 194                 case IFEV_UP:
 195                 case IFEV_UP_FAILED:
 196                 case IFEV_UPDATE:
 197                 case IFEV_DOWN:
 198                         interface_queue_event(iface, ev);
 199                         break;
 200                 case IFEV_FREE:
 201                         interface_dequeue_event(iface);
 202                         break;
 203                 default:
 204                         break;
 205         }
 206 }
 207
 208 static struct interface_user event_user = {
 209         .cb = interface_event_cb
 210 };
 211
 212 static void __init interface_event_init(void)
 213 {
 214         interface_add_user(&event_user, NULL);
 215 }