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         [IFEV_CREATE] = "create",
  42 };
  43
  44 static void
  45 run_cmd(const char *ifname, const char *device, enum interface_event event,
  46                 enum interface_update_flags updated)
  47 {
  48         char *argv[3];
  49         int pid;
  50
  51         pid = fork();
  52         if (pid < 0) {
  53                 task_complete(NULL, -1);
  54                 return;
  55         }
  56
  57         if (pid > 0) {
  58                 task.pid = pid;
  59                 uloop_process_add(&task);
  60                 return;
  61         }
  62
  63         setenv("ACTION", eventnames[event], 1);
  64         setenv("INTERFACE", ifname, 1);
  65         if (device)
  66                 setenv("DEVICE", device, 1);
  67
  68         if (event == IFEV_UPDATE) {
  69                 if (updated & IUF_ADDRESS)
  70                         setenv("IFUPDATE_ADDRESSES", "1", 1);
  71                 if (updated & IUF_ROUTE)
  72                         setenv("IFUPDATE_ROUTES", "1", 1);
  73                 if (updated & IUF_PREFIX)
  74                         setenv("IFUPDATE_PREFIXES", "1", 1);
  75                 if (updated & IUF_DATA)
  76                         setenv("IFUPDATE_DATA", "1", 1);
  77         }
  78
  79         argv[0] = hotplug_cmd_path;
  80         argv[1] = "iface";
  81         argv[2] = NULL;
  82         execvp(argv[0], argv);
  83         exit(127);
  84 }
  85
  86 static void
  87 call_hotplug(void)
  88 {
  89         const char *device = NULL;
  90         if (list_empty(&pending))
  91                 return;
  92
  93         current = list_first_entry(&pending, struct interface, hotplug_list);
  94         current_ev = current->hotplug_ev;
  95         list_del_init(&current->hotplug_list);
  96
  97         if ((current_ev == IFEV_UP || current_ev == IFEV_UPDATE) && current->l3_dev.dev)
  98                 device = current->l3_dev.dev->ifname;
  99
 100         D(SYSTEM, "Call hotplug handler for interface '%s', event '%s' (%s)",
 101         current->name, eventnames[current_ev], device ? device : "none");
 102         run_cmd(current->name, device, current_ev, current->updated);
 103 }
 104
 105 static void
 106 task_complete(struct uloop_process *proc, int ret)
 107 {
 108         if (current)
 109                 D(SYSTEM, "Complete hotplug handler for interface '%s'", current->name);
 110         current = NULL;
 111         call_hotplug();
 112 }
 113
 114 /*
 115  * Queue an interface for an up/down event.
 116  * An interface can only have one event in the queue and one
 117  * event waiting for completion.
 118  * When queueing an event that is the same as the one waiting for
 119  * completion, remove the interface from the queue
 120  */
 121 static void
 122 interface_queue_event(struct interface *iface, enum interface_event ev)
 123 {
 124         D(SYSTEM, "Queue hotplug handler for interface '%s', event '%s'",
 125                         iface->name, eventnames[ev]);
 126         if (ev == IFEV_UP || ev == IFEV_DOWN)
 127                 netifd_ubus_interface_event(iface, ev == IFEV_UP);
 128
 129         netifd_ubus_interface_notify(iface, ev != IFEV_DOWN);
 130
 131         /* no hotplug.d calls for link up */
 132         if (ev == IFEV_LINK_UP)
 133                 return;
 134
 135         if (current == iface) {
 136                 /* an event for iface is being processed */
 137                 if (!list_empty(&iface->hotplug_list)) {
 138                         /* an additional event for iface is pending   */
 139                         /* overwrite pending event if it differs from */
 140                         /* an update                                  */
 141                         if (ev != IFEV_UPDATE)
 142                                 iface->hotplug_ev = ev;
 143                 }
 144                 else {
 145                         /* no additional event for iface is pending */
 146                         if (ev != current_ev || ev == IFEV_UPDATE) {
 147                                 /* only add the interface to the pending list if
 148                                  * the event is different from the one being
 149                                  * handled or if it is an update */
 150                                 iface->hotplug_ev = ev;
 151                                 /* Handle hotplug calls FIFO */
 152                                 list_add_tail(&iface->hotplug_list, &pending);
 153                         }
 154                 }
 155         }
 156         else {
 157                 /* currently not handling an event or handling an event
 158                  * for another interface */
 159                 if (!list_empty(&iface->hotplug_list)) {
 160                         /* an event for iface is pending */
 161                         if (!(iface->hotplug_ev == IFEV_UP &&
 162                                 ev == IFEV_UPDATE)) {
 163                                 /* overwrite pending event, unless the incoming
 164                                  * event is an ifupdate while the pending one
 165                                  * is an ifup */
 166                                 iface->hotplug_ev = ev;
 167                         }
 168                 }
 169                 else {
 170                         /* an event for the interface is not yet pending,
 171                          * queue it */
 172                         iface->hotplug_ev = ev;
 173                         /* Handle hotplug calls FIFO */
 174                         list_add_tail(&iface->hotplug_list, &pending);
 175                 }
 176         }
 177
 178         if (!task.pending && !current)
 179                 call_hotplug();
 180 }
 181
 182 static void
 183 interface_dequeue_event(struct interface *iface)
 184 {
 185         if (iface == current)
 186                 current = NULL;
 187
 188         if (!list_empty(&iface->hotplug_list))
 189                 list_del_init(&iface->hotplug_list);
 190 }
 191
 192 static void interface_event_cb(struct interface_user *dep, struct interface *iface,
 193                                enum interface_event ev)
 194 {
 195         switch (ev) {
 196                 case IFEV_LINK_UP:
 197                 case IFEV_UP:
 198                 case IFEV_UP_FAILED:
 199                 case IFEV_UPDATE:
 200                 case IFEV_DOWN:
 201                         interface_queue_event(iface, ev);
 202                         break;
 203                 case IFEV_FREE:
 204                         interface_dequeue_event(iface);
 205                         break;
 206                 default:
 207                         break;
 208         }
 209 }
 210
 211 static struct interface_user event_user = {
 212         .cb = interface_event_cb
 213 };
 214
 215 static void __init interface_event_init(void)
 216 {
 217         interface_add_user(&event_user, NULL);
 218 }