add support for calls to a hotplug script on interface state changes

[project/netifd.git] / interface-hotplug.c

diff --git a/interface-hotplug.c b/interface-hotplug.c
new file mode 100644 (file)
index 0000000..fff488a
--- /dev/null
+++ b/interface-hotplug.c
@@ -0,0 +1,101 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <libubox/uloop.h>
+
+#include "netifd.h"
+#include "interface.h"
+
+char *hotplug_cmd_path = DEFAULT_HOTPLUG_PATH;
+static struct interface *current;
+static enum interface_event current_ev;
+static struct list_head pending = LIST_HEAD_INIT(pending);
+
+static void task_complete(struct uloop_process *proc, int ret);
+static struct uloop_process task = {
+       .cb = task_complete,
+};
+
+static void
+run_cmd(const char *ifname, bool up)
+{
+       char *argv[3];
+       int pid;
+
+       pid = fork();
+       if (pid < 0)
+               return task_complete(NULL, -1);
+
+       if (pid > 0) {
+               task.pid = pid;
+               uloop_process_add(&task);
+               return;
+       }
+
+       setenv("ACTION", up ? "ifup" : "ifdown", 1);
+       setenv("INTERFACE", ifname, 1);
+       argv[0] = hotplug_cmd_path;
+       argv[1] = "network";
+       argv[2] = NULL;
+       execvp(argv[0], argv);
+       exit(127);
+}
+
+static void
+call_hotplug(void)
+{
+       if (list_empty(&pending))
+               return;
+
+       current = list_first_entry(&pending, struct interface, hotplug_list);
+       current_ev = current->hotplug_ev;
+       list_del_init(&current->hotplug_list);
+       run_cmd(current->name, current_ev == IFEV_UP);
+}
+
+static void
+task_complete(struct uloop_process *proc, int ret)
+{
+       current = NULL;
+       call_hotplug();
+}
+
+/*
+ * Queue an interface for an up/down event.
+ * An interface can only have one event in the queue and one
+ * event waiting for completion.
+ * When queueing an event that is the same as the one waiting for
+ * completion, remove the interface from the queue
+ */
+void
+interface_queue_event(struct interface *iface, enum interface_event ev)
+{
+       enum interface_event last_ev;
+
+       D(SYSTEM, "Queue hotplug handler for interface '%s'\n", iface->name);
+       if (current == iface)
+               last_ev = current_ev;
+       else
+               last_ev = iface->hotplug_ev;
+
+       iface->hotplug_ev = ev;
+       if (last_ev == ev && !list_empty(&iface->hotplug_list))
+               list_del(&iface->hotplug_list);
+       else if (last_ev != ev && list_empty(&iface->hotplug_list))
+               list_add(&iface->hotplug_list, &pending);
+
+       if (!task.pending && !current)
+               call_hotplug();
+}
+
+void
+interface_dequeue_event(struct interface *iface)
+{
+       if (iface == current)
+               current = NULL;
+
+       if (!list_empty(&iface->hotplug_list))
+               list_del_init(&iface->hotplug_list);
+}