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