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