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[] = {"ifdown", "ifup", "ifupdate"};
  34
  35 static void
  36 run_cmd(const char *ifname, const char *device, enum interface_event event,
  37                 enum interface_update_flags updated)
  38 {
  39         char *argv[3];
  40         int pid;
  41
  42         pid = fork();
  43         if (pid < 0)
  44                 return task_complete(NULL, -1);
  45
  46         if (pid > 0) {
  47                 task.pid = pid;
  48                 uloop_process_add(&task);
  49                 return;
  50         }
  51
  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', event '%s' (%s)\n",
  90         current->name, eventnames[current_ev], device ? device : "none");
  91         run_cmd(current->name, device, current_ev, current->updated);
  92 }
  93
  94 static void
  95 task_complete(struct uloop_process *proc, int ret)
  96 {
  97         if (current)
  98                 D(SYSTEM, "Complete hotplug handler for interface '%s'\n", current->name);
  99         current = NULL;
 100         call_hotplug();
 101 }
 102
 103 /*
 104  * Queue an interface for an up/down event.
 105  * An interface can only have one event in the queue and one
 106  * event waiting for completion.
 107  * When queueing an event that is the same as the one waiting for
 108  * completion, remove the interface from the queue
 109  */
 110 static void
 111 interface_queue_event(struct interface *iface, enum interface_event ev)
 112 {
 113         D(SYSTEM, "Queue hotplug handler for interface '%s', event '%s'\n",
 114                         iface->name, eventnames[ev]);
 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                 /* an event for iface is being processed */
 122                 if (!list_empty(&iface->hotplug_list)) {
 123                         /* an additional event for iface is pending */
 124                         if ((ev != current_ev || ev == IFEV_UPDATE) &&
 125                         !(iface->hotplug_ev == IFEV_UP && ev == IFEV_UPDATE)) {
 126                                 /* if incoming event is different from the one
 127                                  * being handled or if it is an update,
 128                                  * overwrite pending event, but never
 129                                  * overwrite an ifup with an ifupdate */
 130                                 iface->hotplug_ev = ev;
 131                         }
 132                         else if (ev == current_ev && ev != IFEV_UPDATE) {
 133                                 /* if incoming event is not an ifupdate
 134                                  * and is the same as the one that is
 135                                  * being handled, remove it from the
 136                                  * pending list */
 137                                 list_del_init(&iface->hotplug_list);
 138                         }
 139                 }
 140                 else {
 141                         /* no additional event for iface is pending */
 142                         if (ev != current_ev || ev == IFEV_UPDATE) {
 143                                 /* only add the interface to the pending list if
 144                                  * the event is different from the one being
 145                                  * handled or if it is an update */
 146                                 iface->hotplug_ev = ev;
 147                                 /* Handle hotplug calls FIFO */
 148                                 list_add_tail(&iface->hotplug_list, &pending);
 149                         }
 150                 }
 151         }
 152         else {
 153                 /* currently not handling an event or handling an event
 154                  * for another interface */
 155                 if (!list_empty(&iface->hotplug_list)) {
 156                         /* an event for iface is pending */
 157                         if (!(iface->hotplug_ev == IFEV_UP &&
 158                                 ev == IFEV_UPDATE)) {
 159                                 /* overwrite pending event, unless the incoming
 160                                  * event is an ifupdate while the pending one
 161                                  * is an ifup */
 162                                 iface->hotplug_ev = ev;
 163                         }
 164                 }
 165                 else {
 166                         /* an event for the interface is not yet pending,
 167                          * queue it */
 168                         iface->hotplug_ev = ev;
 169                         /* Handle hotplug calls FIFO */
 170                         list_add_tail(&iface->hotplug_list, &pending);
 171                 }
 172         }
 173
 174         if (!task.pending && !current)
 175                 call_hotplug();
 176 }
 177
 178 static void
 179 interface_dequeue_event(struct interface *iface)
 180 {
 181         if (iface == current)
 182                 current = NULL;
 183
 184         if (!list_empty(&iface->hotplug_list))
 185                 list_del_init(&iface->hotplug_list);
 186 }
 187
 188 static void interface_event_cb(struct interface_user *dep, struct interface *iface,
 189                                enum interface_event ev)
 190 {
 191         switch (ev) {
 192                 case IFEV_UP:
 193                 case IFEV_UPDATE:
 194                 case IFEV_DOWN:
 195                         interface_queue_event(iface, ev);
 196                         break;
 197                 case IFEV_FREE:
 198                 case IFEV_RELOAD:
 199                         interface_dequeue_event(iface);
 200                         break;
 201         }
 202 }
 203
 204 static struct interface_user event_user = {
 205         .cb = interface_event_cb
 206 };
 207
 208 static void __init interface_event_init(void)
 209 {
 210         interface_add_user(&event_user, NULL);
 211 }