Moved host_t and host_resolver_t to a new networking subfolder

src/libstrongswan/networking/host.c

@@ -0,0 +1,578 @@
+/*
+ * Copyright (C) 2006-2012 Tobias Brunner
+ * Copyright (C) 2006 Daniel Roethlisberger
+ * Copyright (C) 2005-2006 Martin Willi
+ * Copyright (C) 2005 Jan Hutter
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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 "host.h"
+
+#include <debug.h>
+#include <library.h>
+
+#define IPV4_LEN	 4
+#define IPV6_LEN	16
+
+typedef struct private_host_t private_host_t;
+
+/**
+ * Private Data of a host object.
+ */
+struct private_host_t {
+	/**
+	 * Public data
+	 */
+	host_t public;
+
+	/**
+	 * low-lewel structure, which stores the address
+	 */
+	union {
+		/** generic type */
+		struct sockaddr address;
+		/** maximum sockaddr size */
+		struct sockaddr_storage address_max;
+		/** IPv4 address */
+		struct sockaddr_in address4;
+		/** IPv6 address */
+		struct sockaddr_in6 address6;
+	};
+	/**
+	 * length of address structure
+	 */
+	socklen_t socklen;
+};
+
+
+METHOD(host_t, get_sockaddr, sockaddr_t*,
+	private_host_t *this)
+{
+	return &(this->address);
+}
+
+METHOD(host_t, get_sockaddr_len, socklen_t*,
+	private_host_t *this)
+{
+	return &(this->socklen);
+}
+
+METHOD(host_t, is_anyaddr, bool,
+	private_host_t *this)
+{
+	static const u_int8_t zeroes[IPV6_LEN];
+
+	switch (this->address.sa_family)
+	{
+		case AF_INET:
+		{
+			return memeq(zeroes, &(this->address4.sin_addr.s_addr), IPV4_LEN);
+		}
+		case AF_INET6:
+		{
+			return memeq(zeroes, &(this->address6.sin6_addr.s6_addr), IPV6_LEN);
+		}
+		default:
+		{
+			return FALSE;
+		}
+	}
+}
+
+/**
+ * Described in header.
+ */
+int host_printf_hook(printf_hook_data_t *data, printf_hook_spec_t *spec,
+					 const void *const *args)
+{
+	private_host_t *this = *((private_host_t**)(args[0]));
+	char buffer[INET6_ADDRSTRLEN + 16];
+
+	if (this == NULL)
+	{
+		snprintf(buffer, sizeof(buffer), "(null)");
+	}
+	else if (is_anyaddr(this) && !spec->plus)
+	{
+		snprintf(buffer, sizeof(buffer), "%%any%s",
+				 this->address.sa_family == AF_INET6 ? "6" : "");
+	}
+	else
+	{
+		void *address;
+		u_int16_t port;
+		int len;
+
+		address = &this->address6.sin6_addr;
+		port = this->address6.sin6_port;
+
+		switch (this->address.sa_family)
+		{
+			case AF_INET:
+				address = &this->address4.sin_addr;
+				port = this->address4.sin_port;
+				/* fall */
+			case AF_INET6:
+
+				if (inet_ntop(this->address.sa_family, address,
+							  buffer, sizeof(buffer)) == NULL)
+				{
+					snprintf(buffer, sizeof(buffer),
+							 "(address conversion failed)");
+				}
+				else if (spec->hash)
+				{
+					len = strlen(buffer);
+					snprintf(buffer + len, sizeof(buffer) - len,
+							 "[%d]", ntohs(port));
+				}
+				break;
+			default:
+				snprintf(buffer, sizeof(buffer), "(family not supported)");
+				break;
+		}
+	}
+	if (spec->minus)
+	{
+		return print_in_hook(data, "%-*s", spec->width, buffer);
+	}
+	return print_in_hook(data, "%*s", spec->width, buffer);
+}
+
+METHOD(host_t, get_address, chunk_t,
+	private_host_t *this)
+{
+	chunk_t address = chunk_empty;
+
+	switch (this->address.sa_family)
+	{
+		case AF_INET:
+		{
+			address.ptr = (char*)&(this->address4.sin_addr.s_addr);
+			address.len = IPV4_LEN;
+			return address;
+		}
+		case AF_INET6:
+		{
+			address.ptr = (char*)&(this->address6.sin6_addr.s6_addr);
+			address.len = IPV6_LEN;
+			return address;
+		}
+		default:
+		{
+			/* return empty chunk */
+			return address;
+		}
+	}
+}
+
+METHOD(host_t, get_family, int,
+	private_host_t *this)
+{
+	return this->address.sa_family;
+}
+
+METHOD(host_t, get_port, u_int16_t,
+	private_host_t *this)
+{
+	switch (this->address.sa_family)
+	{
+		case AF_INET:
+		{
+			return ntohs(this->address4.sin_port);
+		}
+		case AF_INET6:
+		{
+			return ntohs(this->address6.sin6_port);
+		}
+		default:
+		{
+			return 0;
+		}
+	}
+}
+
+METHOD(host_t, set_port, void,
+	private_host_t *this, u_int16_t port)
+{
+	switch (this->address.sa_family)
+	{
+		case AF_INET:
+		{
+			this->address4.sin_port = htons(port);
+			break;
+		}
+		case AF_INET6:
+		{
+			this->address6.sin6_port = htons(port);
+			break;
+		}
+		default:
+		{
+			break;
+		}
+	}
+}
+
+METHOD(host_t, clone_, host_t*,
+	private_host_t *this)
+{
+	private_host_t *new;
+
+	new = malloc_thing(private_host_t);
+	memcpy(new, this, sizeof(private_host_t));
+
+	return &new->public;
+}
+
+/**
+ * Implements host_t.ip_equals
+ */
+static bool ip_equals(private_host_t *this, private_host_t *other)
+{
+	if (this->address.sa_family != other->address.sa_family)
+	{
+		/* 0.0.0.0 and 0::0 are equal */
+		return (is_anyaddr(this) && is_anyaddr(other));
+	}
+
+	switch (this->address.sa_family)
+	{
+		case AF_INET:
+		{
+			return memeq(&this->address4.sin_addr, &other->address4.sin_addr,
+						 sizeof(this->address4.sin_addr));
+		}
+		case AF_INET6:
+		{
+			return memeq(&this->address6.sin6_addr, &other->address6.sin6_addr,
+						 sizeof(this->address6.sin6_addr));
+		}
+		default:
+			break;
+	}
+	return FALSE;
+}
+
+/**
+ * Implements host_t.get_differences
+ */
+static host_diff_t get_differences(host_t *this, host_t *other)
+{
+	host_diff_t ret = HOST_DIFF_NONE;
+
+	if (!this->ip_equals(this, other))
+	{
+		ret |= HOST_DIFF_ADDR;
+	}
+
+	if (this->get_port(this) != other->get_port(other))
+	{
+		ret |= HOST_DIFF_PORT;
+	}
+
+	return ret;
+}
+
+/**
+ * Implements host_t.equals
+ */
+static bool equals(private_host_t *this, private_host_t *other)
+{
+	if (!ip_equals(this, other))
+	{
+		return FALSE;
+	}
+
+	switch (this->address.sa_family)
+	{
+		case AF_INET:
+		{
+			return (this->address4.sin_port == other->address4.sin_port);
+		}
+		case AF_INET6:
+		{
+			return (this->address6.sin6_port == other->address6.sin6_port);
+		}
+		default:
+			break;
+	}
+	return FALSE;
+}
+
+METHOD(host_t, destroy, void,
+	private_host_t *this)
+{
+	free(this);
+}
+
+/**
+ * Creates an empty host_t object
+ */
+static private_host_t *host_create_empty(void)
+{
+	private_host_t *this;
+
+	INIT(this,
+		.public = {
+			.get_sockaddr = _get_sockaddr,
+			.get_sockaddr_len = _get_sockaddr_len,
+			.clone = _clone_,
+			.get_family = _get_family,
+			.get_address = _get_address,
+			.get_port = _get_port,
+			.set_port = _set_port,
+			.get_differences = get_differences,
+			.ip_equals = (bool (*)(host_t *,host_t *))ip_equals,
+			.equals = (bool (*)(host_t *,host_t *)) equals,
+			.is_anyaddr = _is_anyaddr,
+			.destroy = _destroy,
+		},
+	);
+
+	return this;
+}
+
+/*
+ * Create a %any host with port
+ */
+static host_t *host_create_any_port(int family, u_int16_t port)
+{
+	host_t *this;
+
+	this = host_create_any(family);
+	this->set_port(this, port);
+	return this;
+}
+
+/*
+ * Described in header.
+ */
+host_t *host_create_from_string(char *string, u_int16_t port)
+{
+	private_host_t *this;
+
+	if (streq(string, "%any"))
+	{
+		return host_create_any_port(AF_INET, port);
+	}
+	if (streq(string, "%any6"))
+	{
+		return host_create_any_port(AF_INET6, port);
+	}
+
+	this = host_create_empty();
+	if (strchr(string, '.'))
+	{
+		this->address.sa_family = AF_INET;
+	}
+	else
+	{
+		this->address.sa_family = AF_INET6;
+	}
+	switch (this->address.sa_family)
+	{
+		case AF_INET:
+		{
+			if (inet_pton(AF_INET, string, &this->address4.sin_addr) <=0)
+			{
+				break;
+			}
+			this->address4.sin_port = htons(port);
+			this->socklen = sizeof(struct sockaddr_in);
+			return &this->public;
+		}
+		case AF_INET6:
+		{
+			if (inet_pton(AF_INET6, string, &this->address6.sin6_addr) <=0)
+			{
+				break;
+			}
+			this->address6.sin6_port = htons(port);
+			this->socklen = sizeof(struct sockaddr_in6);
+			return &this->public;
+		}
+		default:
+		{
+			break;
+		}
+	}
+	free(this);
+	return NULL;
+}
+
+/*
+ * Described in header.
+ */
+host_t *host_create_from_sockaddr(sockaddr_t *sockaddr)
+{
+	private_host_t *this = host_create_empty();
+
+	switch (sockaddr->sa_family)
+	{
+		case AF_INET:
+		{
+			memcpy(&this->address4, (struct sockaddr_in*)sockaddr,
+				   sizeof(struct sockaddr_in));
+			this->socklen = sizeof(struct sockaddr_in);
+			return &this->public;
+		}
+		case AF_INET6:
+		{
+			memcpy(&this->address6, (struct sockaddr_in6*)sockaddr,
+				   sizeof(struct sockaddr_in6));
+			this->socklen = sizeof(struct sockaddr_in6);
+			return &this->public;
+		}
+		default:
+			break;
+	}
+	free(this);
+	return NULL;
+}
+
+/*
+ * Described in header.
+ */
+host_t *host_create_from_dns(char *string, int af, u_int16_t port)
+{
+	host_t *this;
+
+	this = lib->hosts->resolve(lib->hosts, string, af);
+	if (this)
+	{
+		this->set_port(this, port);
+	}
+	return this;
+}
+
+/*
+ * Described in header.
+ */
+host_t *host_create_from_chunk(int family, chunk_t address, u_int16_t port)
+{
+	private_host_t *this;
+
+	switch (family)
+	{
+		case AF_INET:
+			if (address.len < IPV4_LEN)
+			{
+				return NULL;
+			}
+			address.len = IPV4_LEN;
+			break;
+		case AF_INET6:
+			if (address.len < IPV6_LEN)
+			{
+				return NULL;
+			}
+			address.len = IPV6_LEN;
+			break;
+		case AF_UNSPEC:
+			switch (address.len)
+			{
+				case IPV4_LEN:
+					family = AF_INET;
+					break;
+				case IPV6_LEN:
+					family = AF_INET6;
+					break;
+				default:
+					return NULL;
+			}
+			break;
+		default:
+			return NULL;
+	}
+	this = host_create_empty();
+	this->address.sa_family = family;
+	switch (family)
+	{
+		case AF_INET:
+			memcpy(&this->address4.sin_addr.s_addr, address.ptr, address.len);
+			this->address4.sin_port = htons(port);
+			this->socklen = sizeof(struct sockaddr_in);
+			break;
+		case AF_INET6:
+			memcpy(&this->address6.sin6_addr.s6_addr, address.ptr, address.len);
+			this->address6.sin6_port = htons(port);
+			this->socklen = sizeof(struct sockaddr_in6);
+			break;
+	}
+	return &this->public;
+}
+
+/*
+ * Described in header.
+ */
+host_t *host_create_from_subnet(char *string, int *bits)
+{
+	char *pos, buf[64];
+	host_t *net;
+
+	pos = strchr(string, '/');
+	if (pos)
+	{
+		if (pos - string >= sizeof(buf))
+		{
+			return NULL;
+		}
+		strncpy(buf, string, pos - string);
+		buf[pos - string] = '\0';
+		*bits = atoi(pos + 1);
+		return host_create_from_string(buf, 0);
+	}
+	net = host_create_from_string(string, 0);
+	if (net)
+	{
+		if (net->get_family(net) == AF_INET)
+		{
+			*bits = 32;
+		}
+		else
+		{
+			*bits = 128;
+		}
+	}
+	return net;
+}
+
+/*
+ * Described in header.
+ */
+host_t *host_create_any(int family)
+{
+	private_host_t *this = host_create_empty();
+
+	memset(&this->address_max, 0, sizeof(struct sockaddr_storage));
+	this->address.sa_family = family;
+
+	switch (family)
+	{
+		case AF_INET:
+		{
+			this->socklen = sizeof(struct sockaddr_in);
+			return &(this->public);
+		}
+		case AF_INET6:
+		{
+			this->socklen = sizeof(struct sockaddr_in6);
+			return &this->public;
+		}
+		default:
+			break;
+	}
+	free(this);
+	return NULL;
+}

src/libstrongswan/networking/host.h

@@ -0,0 +1,220 @@
+/*
+ * Copyright (C) 2006-2009 Tobias Brunner
+ * Copyright (C) 2006 Daniel Roethlisberger
+ * Copyright (C) 2005-2008 Martin Willi
+ * Copyright (C) 2005 Jan Hutter
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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 host host
+ * @{ @ingroup networking
+ */
+
+#ifndef HOST_H_
+#define HOST_H_
+
+typedef enum host_diff_t host_diff_t;
+typedef struct host_t host_t;
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include <chunk.h>
+
+/**
+ * Differences between two hosts. They differ in
+ * address, port, or both.
+ */
+enum host_diff_t {
+	HOST_DIFF_NONE = 0,
+	HOST_DIFF_ADDR = 1,
+	HOST_DIFF_PORT = 2,
+};
+
+/**
+ * Representates a Host
+ *
+ * Host object, identifies a address:port pair and defines some
+ * useful functions on it.
+ */
+struct host_t {
+
+	/**
+	 * Build a clone of this host object.
+	 *
+	 * @return		cloned host
+	 */
+	host_t *(*clone) (host_t *this);
+
+	/**
+	 * Get a pointer to the internal sockaddr struct.
+	 *
+	 * This is used for sending and receiving via sockets.
+	 *
+	 * @return		pointer to the internal sockaddr structure
+	 */
+	sockaddr_t  *(*get_sockaddr) (host_t *this);
+
+	/**
+	 * Get the length of the sockaddr struct.
+	 *
+	 * Depending on the family, the length of the sockaddr struct
+	 * is different. Use this function to get the length of the sockaddr
+	 * struct returned by get_sock_addr.
+	 *
+	 * This is used for sending and receiving via sockets.
+	 *
+	 * @return		length of the sockaddr struct
+	 */
+	socklen_t *(*get_sockaddr_len) (host_t *this);
+
+	/**
+	 * Gets the family of the address
+	 *
+	 * @return		family
+	 */
+	int (*get_family) (host_t *this);
+
+	/**
+	 * Checks if the ip address of host is set to default route.
+	 *
+	 * @return		TRUE if host is 0.0.0.0 or 0::0, FALSE otherwise
+	 */
+	bool (*is_anyaddr) (host_t *this);
+
+	/**
+	 * Get the address of this host as chunk_t
+	 *
+	 * Returned chunk points to internal data.
+	 *
+	 * @return		address string,
+	 */
+	chunk_t (*get_address) (host_t *this);
+
+	/**
+	 * Get the port of this host
+	 *
+	 * @return		port number
+	 */
+	u_int16_t (*get_port) (host_t *this);
+
+	/**
+	 * Set the port of this host
+	 *
+	 * @param port	port numer
+	 */
+	void (*set_port) (host_t *this, u_int16_t port);
+
+	/**
+	 * Compare the ips of two hosts hosts.
+	 *
+	 * @param other	the other to compare
+	 * @return		TRUE if addresses are equal.
+	 */
+	bool (*ip_equals) (host_t *this, host_t *other);
+
+	/**
+	 * Compare two hosts, with port.
+	 *
+	 * @param other	the other to compare
+	 * @return		TRUE if addresses and ports are equal.
+	 */
+	bool (*equals) (host_t *this, host_t *other);
+
+	/**
+	 * Compare two hosts and return the differences.
+	 *
+	 * @param other	the other to compare
+	 * @return		differences in a combination of host_diff_t's
+	 */
+	host_diff_t (*get_differences) (host_t *this, host_t *other);
+
+	/**
+	 * Destroy this host object.
+	 */
+	void (*destroy) (host_t *this);
+};
+
+/**
+ * Constructor to create a host_t object from an address string.
+ *
+ * @param string		string of an address, such as "152.96.193.130"
+ * @param port			port number
+ * @return				host_t, NULL if string not an address.
+ */
+host_t *host_create_from_string(char *string, u_int16_t port);
+
+/**
+ * Constructor to create a host_t from a DNS name.
+ *
+ * @param string		hostname to resolve
+ * @param family		family to prefer, 0 for first match
+ * @param port			port number
+ * @return				host_t, NULL lookup failed
+ */
+host_t *host_create_from_dns(char *string, int family, u_int16_t port);
+
+/**
+ * Constructor to create a host_t object from an address chunk.
+ *
+ * If family is AF_UNSPEC, it is guessed using address.len.
+ *
+ * @param family		Address family, such as AF_INET or AF_INET6
+ * @param address		address as chunk_t in network order
+ * @param port			port number
+ * @return				host_t, NULL if family not supported/chunk invalid
+ */
+host_t *host_create_from_chunk(int family, chunk_t address, u_int16_t port);
+
+/**
+ * Constructor to create a host_t object from a sockaddr struct
+ *
+ * @param sockaddr		sockaddr struct which contains family, address and port
+ * @return				host_t, NULL if family not supported
+ */
+host_t *host_create_from_sockaddr(sockaddr_t *sockaddr);
+
+/**
+ * Create a host from a CIDR subnet definition (1.2.3.0/24), return bits.
+ *
+ * @param string		string to parse
+ * @param bits			gets the number of network bits in CIDR notation
+ * @return				network start address, NULL on error
+ */
+host_t *host_create_from_subnet(char *string, int *bits);
+
+/**
+ * Create a host without an address, a "any" host.
+ *
+ * @param family		family of the any host
+ * @return				host_t, NULL if family not supported
+ */
+host_t *host_create_any(int family);
+
+/**
+ * printf hook function for host_t.
+ *
+ * Arguments are:
+ *	host_t *host
+ * Use #-modifier to include port number
+ * Use +-modifier to force numeric representation (instead of e.g. %any)
+ */
+int host_printf_hook(printf_hook_data_t *data, printf_hook_spec_t *spec,
+					 const void *const *args);
+
+#endif /** HOST_H_ @}*/

src/libstrongswan/networking/host_resolver.c

@@ -0,0 +1,391 @@
+/*
+ * Copyright (C) 2012 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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 <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+
+#include "host_resolver.h"
+
+#include <debug.h>
+#include <library.h>
+#include <threading/condvar.h>
+#include <threading/mutex.h>
+#include <threading/thread.h>
+#include <utils/hashtable.h>
+#include <utils/linked_list.h>
+
+/**
+ * Default minimum and maximum number of threads
+ */
+#define MIN_THREADS_DEFAULT 0
+#define MAX_THREADS_DEFAULT 3
+
+/**
+ * Timeout in seconds to wait for new queries until a thread may be stopped
+ */
+#define NEW_QUERY_WAIT_TIMEOUT 30
+
+typedef struct private_host_resolver_t private_host_resolver_t;
+
+/**
+ * Private data of host_resolver_t
+ */
+struct private_host_resolver_t {
+
+	/**
+	 * Public interface
+	 */
+	host_resolver_t public;
+
+	/**
+	 * Hashtable to check for queued queries, query_t*
+	 */
+	hashtable_t *queries;
+
+	/**
+	 * Queue for queries, query_t*
+	 */
+	linked_list_t *queue;
+
+	/**
+	 * Mutex to safely access private data
+	 */
+	mutex_t *mutex;
+
+	/**
+	 * Condvar to signal arrival of new queries
+	 */
+	condvar_t *new_query;
+
+	/**
+	 * Minimum number of resolver threads
+	 */
+	u_int min_threads;
+
+	/**
+	 * Maximum number of resolver threads
+	 */
+	u_int max_threads;
+
+	/**
+	 * Current number of threads
+	 */
+	u_int threads;
+
+	/**
+	 * Current number of busy threads
+	 */
+	u_int busy_threads;
+
+	/**
+	 * Pool of threads, thread_t*
+	 */
+	linked_list_t *pool;
+
+	/**
+	 * TRUE if no new queries are accepted
+	 */
+	bool disabled;
+
+};
+
+typedef struct {
+	/** DNS name we are looking for */
+	char *name;
+	/** address family we request */
+	int family;
+	/** Condvar to signal completion of a query */
+	condvar_t *done;
+	/** refcount */
+	refcount_t refcount;
+	/** the result if successful */
+	host_t *result;
+} query_t;
+
+/**
+ * Destroy the given query_t object if refcount is zero
+ */
+static void query_destroy(query_t *this)
+{
+	if (ref_put(&this->refcount))
+	{
+		DESTROY_IF(this->result);
+		this->done->destroy(this->done);
+		free(this->name);
+		free(this);
+	}
+}
+
+/**
+ * Signals all waiting threads and destroys the query
+ */
+static void query_signal_and_destroy(query_t *this)
+{
+	this->done->broadcast(this->done);
+	query_destroy(this);
+}
+
+/**
+ * Hash a queued query
+ */
+static u_int query_hash(query_t *this)
+{
+	return chunk_hash_inc(chunk_create(this->name, strlen(this->name)),
+						  chunk_hash(chunk_from_thing(this->family)));
+}
+
+/**
+ * Compare two queued queries
+ */
+static bool query_equals(query_t *this, query_t *other)
+{
+	return this->family == other->family && streq(this->name, other->name);
+}
+
+/**
+ * Main function of resolver threads
+ */
+static void *resolve_hosts(private_host_resolver_t *this)
+{
+	struct addrinfo hints, *result;
+	query_t *query;
+	int error;
+	bool old, timed_out;
+
+	while (TRUE)
+	{
+		this->mutex->lock(this->mutex);
+		thread_cleanup_push((thread_cleanup_t)this->mutex->unlock, this->mutex);
+		while (this->queue->remove_first(this->queue,
+										(void**)&query) != SUCCESS)
+		{
+			old = thread_cancelability(TRUE);
+			timed_out = this->new_query->timed_wait(this->new_query,
+									this->mutex, NEW_QUERY_WAIT_TIMEOUT * 1000);
+			thread_cancelability(old);
+			if (this->disabled)
+			{
+				thread_cleanup_pop(TRUE);
+				return NULL;
+			}
+			else if (timed_out && (this->threads > this->min_threads))
+			{	/* terminate this thread by detaching it */
+				thread_t *thread = thread_current();
+
+				this->threads--;
+				this->pool->remove(this->pool, thread, NULL);
+				thread_cleanup_pop(TRUE);
+				thread->detach(thread);
+				return NULL;
+			}
+		}
+		this->busy_threads++;
+		thread_cleanup_pop(TRUE);
+
+		memset(&hints, 0, sizeof(hints));
+		hints.ai_family = query->family;
+		hints.ai_socktype = SOCK_DGRAM;
+
+		thread_cleanup_push((thread_cleanup_t)query_signal_and_destroy, query);
+		old = thread_cancelability(TRUE);
+		error = getaddrinfo(query->name, NULL, &hints, &result);
+		thread_cancelability(old);
+		thread_cleanup_pop(FALSE);
+
+		this->mutex->lock(this->mutex);
+		this->busy_threads--;
+		if (error != 0)
+		{
+			DBG1(DBG_LIB, "resolving '%s' failed: %s", query->name,
+				 gai_strerror(error));
+		}
+		else
+		{	/* result is a linked list, but we use only the first address */
+			query->result = host_create_from_sockaddr(result->ai_addr);
+			freeaddrinfo(result);
+		}
+		this->queries->remove(this->queries, query);
+		query->done->broadcast(query->done);
+		this->mutex->unlock(this->mutex);
+		query_destroy(query);
+	}
+	return NULL;
+}
+
+/**
+ * Try to convert IP addresses directly
+ */
+static host_t *try_numeric_lookup(char *name, int family)
+{
+	struct addrinfo hints, *result;
+	int error;
+	host_t *host;
+
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = family;
+	hints.ai_socktype = SOCK_DGRAM;
+	hints.ai_flags = AI_NUMERICHOST;
+
+	error = getaddrinfo(name, NULL, &hints, &result);
+	if (error != 0)
+	{	/* not an IP address */
+		return NULL;
+	}
+	else
+	{	/* result is a linked list, but we use only the first address */
+		host = host_create_from_sockaddr(result->ai_addr);
+		freeaddrinfo(result);
+	}
+	return host;
+}
+
+METHOD(host_resolver_t, resolve, host_t*,
+	private_host_resolver_t *this, char *name, int family)
+{
+	query_t *query, lookup = {
+		.name = name,
+		.family = family,
+	};
+	host_t *result;
+
+	if (streq(name, "%any") || streq(name, "0.0.0.0"))
+	{
+		return host_create_any(family ? family : AF_INET);
+	}
+	if (streq(name, "%any6") || streq(name, "::"))
+	{
+		return host_create_any(family ? family : AF_INET6);
+	}
+	if (family == AF_INET && strchr(name, ':'))
+	{	/* do not try to convert v6 addresses for v4 family */
+		return NULL;
+	}
+	result = try_numeric_lookup(name, family);
+	if (result)
+	{	/* shortcut for numeric IP addresses */
+		return result;
+	}
+	this->mutex->lock(this->mutex);
+	if (this->disabled)
+	{
+		this->mutex->unlock(this->mutex);
+		return NULL;
+	}
+	query = this->queries->get(this->queries, &lookup);
+	if (!query)
+	{
+		INIT(query,
+			.name = strdup(name),
+			.family = family,
+			.done = condvar_create(CONDVAR_TYPE_DEFAULT),
+			.refcount = 1,
+		);
+		this->queries->put(this->queries, query, query);
+		this->queue->insert_last(this->queue, query);
+		this->new_query->signal(this->new_query);
+	}
+	ref_get(&query->refcount);
+	if (this->busy_threads == this->threads &&
+		this->threads < this->max_threads)
+	{
+		thread_t *thread;
+
+		thread = thread_create((thread_main_t)resolve_hosts, this);
+		if (thread)
+		{
+			this->threads++;
+			this->pool->insert_last(this->pool, thread);
+		}
+	}
+	query->done->wait(query->done, this->mutex);
+	this->mutex->unlock(this->mutex);
+
+	result = query->result ? query->result->clone(query->result) : NULL;
+	query_destroy(query);
+	return result;
+}
+
+METHOD(host_resolver_t, flush, void,
+	private_host_resolver_t *this)
+{
+	enumerator_t *enumerator;
+	query_t *query;
+
+	this->mutex->lock(this->mutex);
+	enumerator = this->queries->create_enumerator(this->queries);
+	while (enumerator->enumerate(enumerator, &query, NULL))
+	{	/* use the hashtable here as we also want to signal dequeued queries */
+		this->queries->remove_at(this->queries, enumerator);
+		query->done->broadcast(query->done);
+	}
+	enumerator->destroy(enumerator);
+	this->queue->destroy_function(this->queue, (void*)query_destroy);
+	this->queue = linked_list_create();
+	this->disabled = TRUE;
+	/* this will already terminate most idle threads */
+	this->new_query->broadcast(this->new_query);
+	this->mutex->unlock(this->mutex);
+}
+
+METHOD(host_resolver_t, destroy, void,
+	private_host_resolver_t *this)
+{
+	thread_t *thread;
+
+	flush(this);
+	this->pool->invoke_offset(this->pool, offsetof(thread_t, cancel));
+	while (this->pool->remove_first(this->pool, (void**)&thread) == SUCCESS)
+	{
+		thread->join(thread);
+	}
+	this->pool->destroy(this->pool);
+	this->queue->destroy(this->queue);
+	this->queries->destroy(this->queries);
+	this->new_query->destroy(this->new_query);
+	this->mutex->destroy(this->mutex);
+	free(this);
+}
+
+/*
+ * Described in header
+ */
+host_resolver_t *host_resolver_create()
+{
+	private_host_resolver_t *this;
+
+	INIT(this,
+		.public = {
+			.resolve = _resolve,
+			.flush = _flush,
+			.destroy = _destroy,
+		},
+		.queries = hashtable_create((hashtable_hash_t)query_hash,
+									(hashtable_equals_t)query_equals, 8),
+		.queue = linked_list_create(),
+		.pool = linked_list_create(),
+		.mutex = mutex_create(MUTEX_TYPE_DEFAULT),
+		.new_query = condvar_create(CONDVAR_TYPE_DEFAULT),
+	);
+
+	this->min_threads = max(0, lib->settings->get_int(lib->settings,
+									"libstrongswan.host_resolver.min_threads",
+									 MIN_THREADS_DEFAULT));
+	this->max_threads = max(this->min_threads ?: 1,
+							lib->settings->get_int(lib->settings,
+									"libstrongswan.host_resolver.max_threads",
+									 MAX_THREADS_DEFAULT));
+	return &this->public;
+}

src/libstrongswan/networking/host_resolver.h

@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2012 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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 host_resolver host_resolver
+ * @{ @ingroup networking
+ */
+
+#ifndef HOST_RESOLVER_H_
+#define HOST_RESOLVER_H_
+
+#include "host.h"
+
+typedef struct host_resolver_t host_resolver_t;
+
+/**
+ * Resolve hosts by DNS name but do so in a separate thread (calling
+ * getaddrinfo(3) directly might block indefinitely, or at least a very long
+ * time if no DNS servers are reachable).
+ */
+struct host_resolver_t {
+
+	/**
+	 * Resolve host from the given DNS name.
+	 *
+	 * @param name		name to lookup
+	 * @param family	requested address family
+	 * @return			resolved host or NULL if failed or canceled
+	 */
+	host_t *(*resolve)(host_resolver_t *this, char *name, int family);
+
+	/**
+	 * Flush the queue of queries. No new queries will be accepted afterwards.
+	 */
+	void (*flush)(host_resolver_t *this);
+
+	/**
+	 * Destroy a host_resolver_t.
+	 */
+	void (*destroy)(host_resolver_t *this);
+};
+
+/**
+ * Create a host_resolver_t instance.
+ */
+host_resolver_t *host_resolver_create();
+
+#endif /** HOST_RESOLVER_H_ @}*/