Notify duplicate detections over a UNIX sockets to listening applications

src/libcharon/plugins/duplicheck/Makefile.am

@@ -2,7 +2,8 @@
 INCLUDES = -I$(top_srcdir)/src/libstrongswan -I$(top_srcdir)/src/libhydra \
 	-I$(top_srcdir)/src/libcharon
 
-AM_CFLAGS = -rdynamic
+AM_CFLAGS = -rdynamic \
+	-DIPSEC_PIDDIR=\"${piddir}\"
 
 if MONOLITHIC
 noinst_LTLIBRARIES = libstrongswan-duplicheck.la
@@ -11,6 +12,7 @@ plugin_LTLIBRARIES = libstrongswan-duplicheck.la
 endif
 
 libstrongswan_duplicheck_la_SOURCES = duplicheck_plugin.h duplicheck_plugin.c \
-	duplicheck_listener.h duplicheck_listener.c
+	duplicheck_listener.h duplicheck_listener.c \
+	duplicheck_notify.h duplicheck_notify.c
 
 libstrongswan_duplicheck_la_LDFLAGS = -module -avoid-version

src/libcharon/plugins/duplicheck/duplicheck_listener.c

@@ -33,6 +33,11 @@ struct private_duplicheck_listener_t {
 	 */
 	duplicheck_listener_t public;
 
+	/**
+	 * Socket to send notifications to
+	 */
+	duplicheck_notify_t *notify;
+
 	/**
 	 * Mutex to lock hashtables
 	 */
@@ -176,6 +181,7 @@ METHOD(listener_t, message_hook, bool,
 						(job_t*)delete_ike_sa_job_create(entry->sa, TRUE));
 				entry_destroy(entry);
 			}
+			this->notify->send(this->notify, id);
 		}
 	}
 	return TRUE;
@@ -211,7 +217,7 @@ METHOD(duplicheck_listener_t, destroy, void,
 /**
  * See header
  */
-duplicheck_listener_t *duplicheck_listener_create()
+duplicheck_listener_t *duplicheck_listener_create(duplicheck_notify_t *notify)
 {
 	private_duplicheck_listener_t *this;
 
@@ -224,6 +230,7 @@ duplicheck_listener_t *duplicheck_listener_create()
 			},
 			.destroy = _destroy,
 		},
+		.notify = notify,
 		.mutex = mutex_create(MUTEX_TYPE_DEFAULT),
 		.active = hashtable_create((hashtable_hash_t)hash,
 								   (hashtable_equals_t)equals, 32),

src/libcharon/plugins/duplicheck/duplicheck_listener.h

@@ -21,6 +21,8 @@
 #ifndef DUPLICHECK_LISTENER_H_
 #define DUPLICHECK_LISTENER_H_
 
+#include "duplicheck_notify.h"
+
 #include <bus/listeners/listener.h>
 
 typedef struct duplicheck_listener_t duplicheck_listener_t;
@@ -43,7 +45,10 @@ struct duplicheck_listener_t {
 
 /**
  * Create a duplicheck_listener instance.
+ *
+ * @param notify		socket to send notifications to
+ * @return				listener
  */
-duplicheck_listener_t *duplicheck_listener_create();
+duplicheck_listener_t *duplicheck_listener_create(duplicheck_notify_t *notify);
 
 #endif /** DUPLICHECK_LISTENER_H_ @}*/

src/libcharon/plugins/duplicheck/duplicheck_notify.c

@@ -0,0 +1,211 @@
+/*
+ * Copyright (C) 2011 Martin Willi
+ * Copyright (C) 2011 revosec AG
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+#include "duplicheck_notify.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include <daemon.h>
+#include <threading/mutex.h>
+#include <threading/thread.h>
+#include <utils/linked_list.h>
+#include <processing/jobs/callback_job.h>
+
+#define DUPLICHECK_SOCKET IPSEC_PIDDIR "/charon.dck"
+
+typedef struct private_duplicheck_notify_t private_duplicheck_notify_t;
+
+/**
+ * Private data of an duplicheck_notify_t object.
+ */
+struct private_duplicheck_notify_t {
+
+	/**
+	 * Public duplicheck_notify_t interface.
+	 */
+	duplicheck_notify_t public;
+
+	/**
+	 * Callback job dispatching connections
+	 */
+	callback_job_t *job;
+
+	/**
+	 * Mutex to lock list
+	 */
+	mutex_t *mutex;
+
+	/**
+	 * List of connected sockets
+	 */
+	linked_list_t *connected;
+
+	/**
+	 * Socket dispatching connections
+	 */
+	int socket;
+};
+
+/**
+ * Open duplicheck unix socket
+ */
+static bool open_socket(private_duplicheck_notify_t *this)
+{
+	struct sockaddr_un addr;
+	mode_t old;
+
+	addr.sun_family = AF_UNIX;
+	strcpy(addr.sun_path, DUPLICHECK_SOCKET);
+
+	this->socket = socket(AF_UNIX, SOCK_SEQPACKET, 0);
+	if (this->socket == -1)
+	{
+		DBG1(DBG_CFG, "creating duplicheck socket failed");
+		return FALSE;
+	}
+	unlink(addr.sun_path);
+	old = umask(~(S_IRWXU | S_IRWXG));
+	if (bind(this->socket, (struct sockaddr*)&addr, sizeof(addr)) < 0)
+	{
+		DBG1(DBG_CFG, "binding duplicheck socket failed: %s", strerror(errno));
+		close(this->socket);
+		return FALSE;
+	}
+	umask(old);
+	if (chown(addr.sun_path, charon->uid, charon->gid) != 0)
+	{
+		DBG1(DBG_CFG, "changing duplicheck socket permissions failed: %s",
+			 strerror(errno));
+	}
+	if (listen(this->socket, 3) < 0)
+	{
+		DBG1(DBG_CFG, "listening on duplicheck socket failed: %s",
+			 strerror(errno));
+		close(this->socket);
+		unlink(addr.sun_path);
+		return FALSE;
+	}
+	return TRUE;
+}
+
+/**
+ * Accept duplicheck notification connections
+ */
+static job_requeue_t receive(private_duplicheck_notify_t *this)
+{
+	struct sockaddr_un addr;
+	int len = sizeof(addr);
+	uintptr_t fd;
+	bool oldstate;
+
+	oldstate = thread_cancelability(TRUE);
+	fd = accept(this->socket, (struct sockaddr*)&addr, &len);
+	thread_cancelability(oldstate);
+
+	if (fd != -1)
+	{
+		this->mutex->lock(this->mutex);
+		this->connected->insert_last(this->connected, (void*)fd);
+		this->mutex->unlock(this->mutex);
+	 }
+	 else
+	 {
+		 DBG1(DBG_CFG, "accepting duplicheck connection failed: %s",
+			  strerror(errno));
+	 }
+	 return JOB_REQUEUE_FAIR;
+}
+
+METHOD(duplicheck_notify_t, send_, void,
+	private_duplicheck_notify_t *this, identification_t *id)
+{
+	char buf[128];
+	enumerator_t *enumerator;
+	uintptr_t fd;
+	int len;
+
+	len = snprintf(buf, sizeof(buf), "%Y", id);
+	if (len > 0 && len < sizeof(buf))
+	{
+		this->mutex->lock(this->mutex);
+		enumerator = this->connected->create_enumerator(this->connected);
+		while (enumerator->enumerate(enumerator, &fd))
+		{
+			if (send(fd, &buf, len + 1, 0) != len + 1)
+			{
+				DBG1(DBG_CFG, "sending duplicheck notify failed: %s",
+					 strerror(errno));
+				this->connected->remove_at(this->connected, enumerator);
+				close(fd);
+			}
+		}
+		enumerator->destroy(enumerator);
+		this->mutex->unlock(this->mutex);
+	}
+}
+
+METHOD(duplicheck_notify_t, destroy, void,
+	private_duplicheck_notify_t *this)
+{
+	enumerator_t *enumerator;
+	uintptr_t fd;
+
+	if (this->job)
+	{
+		this->job->cancel(this->job);
+	}
+	enumerator = this->connected->create_enumerator(this->connected);
+	while (enumerator->enumerate(enumerator, &fd))
+	{
+		close(fd);
+	}
+	enumerator->destroy(enumerator);
+	this->connected->destroy(this->connected);
+	this->mutex->destroy(this->mutex);
+	free(this);
+}
+
+/**
+ * See header
+ */
+duplicheck_notify_t *duplicheck_notify_create()
+{
+	private_duplicheck_notify_t *this;
+
+	INIT(this,
+		.public = {
+			.send = _send_,
+			.destroy = _destroy,
+		},
+		.connected = linked_list_create(),
+		.mutex = mutex_create(MUTEX_TYPE_DEFAULT),
+	);
+
+	if (!open_socket(this))
+	{
+		destroy(this);
+		return NULL;
+	}
+	this->job = callback_job_create((callback_job_cb_t)receive,
+									this, NULL, NULL);
+	lib->processor->queue_job(lib->processor, (job_t*)this->job);
+
+	return &this->public;
+}

src/libcharon/plugins/duplicheck/duplicheck_notify.h

@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2011 Martin Willi
+ * Copyright (C) 2011 revosec AG
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+/**
+ * @defgroup duplicheck_notify duplicheck_notify
+ * @{ @ingroup duplicheck
+ */
+
+#ifndef DUPLICHECK_NOTIFY_H_
+#define DUPLICHECK_NOTIFY_H_
+
+#include <utils/identification.h>
+
+typedef struct duplicheck_notify_t duplicheck_notify_t;
+
+/**
+ * Sends notifications over a unix socket when duplicates are detected.
+ */
+struct duplicheck_notify_t {
+
+	/**
+	 * Send a notification message if duplicate IKE_SA detected.
+	 *
+	 * @param id		identity a duplicate tunnel has been detected
+	 */
+	void (*send)(duplicheck_notify_t *this, identification_t *id);
+
+	/**
+	 * Destroy a duplicheck_notify_t.
+	 */
+	void (*destroy)(duplicheck_notify_t *this);
+};
+
+/**
+ * Create a duplicheck_notify instance.
+ */
+duplicheck_notify_t *duplicheck_notify_create();
+
+#endif /** DUPLICHECK_NOTIFY_H_ @}*/

src/libcharon/plugins/duplicheck/duplicheck_plugin.c

@@ -15,6 +15,7 @@
 
 #include "duplicheck_plugin.h"
 
+#include "duplicheck_notify.h"
 #include "duplicheck_listener.h"
 
 #include <daemon.h>
@@ -35,12 +36,18 @@ struct private_duplicheck_plugin_t {
 	 * Listener doing duplicate checks
 	 */
 	duplicheck_listener_t *listener;
+
+	/**
+	 * Notification sender facility
+	 */
+	duplicheck_notify_t *notify;
 };
 
 METHOD(plugin_t, destroy, void,
 	private_duplicheck_plugin_t *this)
 {
 	charon->bus->remove_listener(charon->bus, &this->listener->listener);
+	this->notify->destroy(this->notify);
 	this->listener->destroy(this->listener);
 	free(this);
 }
@@ -58,9 +65,15 @@ plugin_t *duplicheck_plugin_create()
 				.destroy = _destroy,
 			},
 		},
-		.listener = duplicheck_listener_create(),
+		.notify = duplicheck_notify_create(),
 	);
 
+	if (!this->notify)
+	{
+		free(this);
+		return NULL;
+	}
+	this->listener = duplicheck_listener_create(this->notify);
 	charon->bus->add_listener(charon->bus, &this->listener->listener);
 
 	return &this->public.plugin;