interface-hotplug.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <unistd.h>
   5
   6 #include <libubox/uloop.h>
   7
   8 #include "netifd.h"
   9 #include "interface.h"
  10
  11 char *hotplug_cmd_path = DEFAULT_HOTPLUG_PATH;
  12 static struct interface *current;
  13 static enum interface_event current_ev;
  14 static struct list_head pending = LIST_HEAD_INIT(pending);
  15
  16 static void task_complete(struct uloop_process *proc, int ret);
  17 static struct uloop_process task = {
  18         .cb = task_complete,
  19 };
  20
  21 static void
  22 run_cmd(const char *ifname, bool up)
  23 {
  24         char *argv[3];
  25         int pid;
  26
  27         pid = fork();
  28         if (pid < 0)
  29                 return task_complete(NULL, -1);
  30
  31         if (pid > 0) {
  32                 task.pid = pid;
  33                 uloop_process_add(&task);
  34                 return;
  35         }
  36
  37         setenv("ACTION", up ? "ifup" : "ifdown", 1);
  38         setenv("INTERFACE", ifname, 1);
  39         argv[0] = hotplug_cmd_path;
  40         argv[1] = "network";
  41         argv[2] = NULL;
  42         execvp(argv[0], argv);
  43         exit(127);
  44 }
  45
  46 static void
  47 call_hotplug(void)
  48 {
  49         if (list_empty(&pending))
  50                 return;
  51
  52         current = list_first_entry(&pending, struct interface, hotplug_list);
  53         current_ev = current->hotplug_ev;
  54         list_del_init(&current->hotplug_list);
  55         run_cmd(current->name, current_ev == IFEV_UP);
  56 }
  57
  58 static void
  59 task_complete(struct uloop_process *proc, int ret)
  60 {
  61         current = NULL;
  62         call_hotplug();
  63 }
  64
  65 /*
  66  * Queue an interface for an up/down event.
  67  * An interface can only have one event in the queue and one
  68  * event waiting for completion.
  69  * When queueing an event that is the same as the one waiting for
  70  * completion, remove the interface from the queue
  71  */
  72 void
  73 interface_queue_event(struct interface *iface, enum interface_event ev)
  74 {
  75         enum interface_event last_ev;
  76
  77         D(SYSTEM, "Queue hotplug handler for interface '%s'\n", iface->name);
  78         if (current == iface)
  79                 last_ev = current_ev;
  80         else
  81                 last_ev = iface->hotplug_ev;
  82
  83         iface->hotplug_ev = ev;
  84         if (last_ev == ev && !list_empty(&iface->hotplug_list))
  85                 list_del(&iface->hotplug_list);
  86         else if (last_ev != ev && list_empty(&iface->hotplug_list))
  87                 list_add(&iface->hotplug_list, &pending);
  88
  89         if (!task.pending && !current)
  90                 call_hotplug();
  91 }
  92
  93 void
  94 interface_dequeue_event(struct interface *iface)
  95 {
  96         if (iface == current)
  97                 current = NULL;
  98
  99         if (!list_empty(&iface->hotplug_list))
 100                 list_del_init(&iface->hotplug_list);
 101 }