src/proto_udp.c - haproxy - Gitiles

 /*
  * AF_CUST_UDP/AF_CUST_UDP6 UDP protocol layer
  *
  * Copyright 2019 HAProxy Technologies, Frédéric Lécaille <flecaille@haproxy.com>
  *
  * Partial merge by Emeric Brun <ebrun@haproxy.com>
  *
  * 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.
  *
  */

 #include <ctype.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>

 #include <sys/param.h>
 #include <sys/socket.h>
 #include <sys/types.h>

 #include <netinet/udp.h>
 #include <netinet/in.h>

 #include <haproxy/fd.h>
 #include <haproxy/listener.h>
 #include <haproxy/log.h>
 #include <haproxy/namespace.h>
 #include <haproxy/port_range.h>
 #include <haproxy/protocol.h>
 #include <haproxy/proto_udp.h>
 #include <haproxy/proxy.h>
 #include <haproxy/server.h>
 #include <haproxy/sock.h>
 #include <haproxy/sock_inet.h>
 #include <haproxy/task.h>

 static int udp_bind_listener(struct listener *listener, char *errmsg, int errlen);
 static void udp4_add_listener(struct listener *listener, int port);
 static void udp6_add_listener(struct listener *listener, int port);

 /* Note: must not be declared <const> as its list will be overwritten */
 static struct protocol proto_udp4 = {
 	.name = "udp4",
 	.sock_domain = AF_CUST_UDP4,
 	.sock_type = SOCK_DGRAM,
 	.sock_prot = IPPROTO_UDP,
 	.sock_family = AF_INET,
 	.sock_addrlen = sizeof(struct sockaddr_in),
 	.l3_addrlen = 32/8,
 	.accept = NULL,
 	.connect = NULL,
 	.bind = udp_bind_listener,
 	.enable_all = enable_all_listeners,
 	.get_src = udp_get_src,
 	.get_dst = udp_get_dst,
 	.pause = udp_pause_listener,
 	.add = udp4_add_listener,
 	.addrcmp = sock_inet4_addrcmp,
 	.listeners = LIST_HEAD_INIT(proto_udp4.listeners),
 	.nb_listeners = 0,
 };

 INITCALL1(STG_REGISTER, protocol_register, &proto_udp4);

 /* Note: must not be declared <const> as its list will be overwritten */
 static struct protocol proto_udp6 = {
 	.name = "udp6",
 	.sock_domain = AF_CUST_UDP6,
 	.sock_type = SOCK_DGRAM,
 	.sock_prot = IPPROTO_UDP,
 	.sock_family = AF_INET6,
 	.sock_addrlen = sizeof(struct sockaddr_in6),
 	.l3_addrlen = 128/8,
 	.accept = NULL,
 	.connect = NULL,
 	.bind = udp_bind_listener,
 	.enable_all = enable_all_listeners,
 	.get_src = udp6_get_src,
 	.get_dst = udp6_get_dst,
 	.pause = udp_pause_listener,
 	.add = udp6_add_listener,
 	.addrcmp = sock_inet6_addrcmp,
 	.listeners = LIST_HEAD_INIT(proto_udp6.listeners),
 	.nb_listeners = 0,
 };

 INITCALL1(STG_REGISTER, protocol_register, &proto_udp6);

 /*
  * Retrieves the source address for the socket <fd>, with <dir> indicating
  * if we're a listener (=0) or an initiator (!=0). It returns 0 in case of
  * success, -1 in case of error. The socket's source address is stored in
  * <sa> for <salen> bytes.
  */
 int udp_get_src(int fd, struct sockaddr *sa, socklen_t salen, int dir)
 {
 	int ret;

 	ret = sock_get_src(fd, sa, salen, dir);
 	if (!ret)
 		sa->sa_family = AF_CUST_UDP4;

 	return ret;
 }

 /*
  * Retrieves the source address for the socket <fd>, with <dir> indicating
  * if we're a listener (=0) or an initiator (!=0). It returns 0 in case of
  * success, -1 in case of error. The socket's source address is stored in
  * <sa> for <salen> bytes.
  */
 int udp6_get_src(int fd, struct sockaddr *sa, socklen_t salen, int dir)
 {
 	int ret;

 	ret = sock_get_src(fd, sa, salen, dir);
 	if (!ret)
 		sa->sa_family = AF_CUST_UDP6;

 	return ret;
 }

 /*
  * Retrieves the original destination address for the socket <fd>, with <dir>
  * indicating if we're a listener (=0) or an initiator (!=0). In the case of a
  * listener, if the original destination address was translated, the original
  * address is retrieved. It returns 0 in case of success, -1 in case of error.
  * The socket's source address is stored in <sa> for <salen> bytes.
  */
 int udp_get_dst(int fd, struct sockaddr *sa, socklen_t salen, int dir)
 {
 	int ret;

 	ret = sock_inet_get_dst(fd, sa, salen, dir);
 	if (!ret)
 		sa->sa_family = AF_CUST_UDP4;

 	return ret;
 }

 /*
  * Retrieves the original destination address for the socket <fd>, with <dir>
  * indicating if we're a listener (=0) or an initiator (!=0). In the case of a
  * listener, if the original destination address was translated, the original
  * address is retrieved. It returns 0 in case of success, -1 in case of error.
  * The socket's source address is stored in <sa> for <salen> bytes.
  */
 int udp6_get_dst(int fd, struct sockaddr *sa, socklen_t salen, int dir)
 {
 	int ret;

 	ret = sock_get_dst(fd, sa, salen, dir);
 	if (!ret)
 		sa->sa_family = AF_CUST_UDP6;

 	return ret;
 }

 /* This function tries to bind a UDPv4/v6 listener. It may return a warning or
  * an error message in <errmsg> if the message is at most <errlen> bytes long
  * (including '\0'). Note that <errmsg> may be NULL if <errlen> is also zero.
  * The return value is composed from ERR_ABORT, ERR_WARN,
  * ERR_ALERT, ERR_RETRYABLE and ERR_FATAL. ERR_NONE indicates that everything
  * was alright and that no message was returned. ERR_RETRYABLE means that an
  * error occurred but that it may vanish after a retry (eg: port in use), and
  * ERR_FATAL indicates a non-fixable error. ERR_WARN and ERR_ALERT do not alter
  * the meaning of the error, but just indicate that a message is present which
  * should be displayed with the respective level. Last, ERR_ABORT indicates
  * that it's pointless to try to start other listeners. No error message is
  * returned if errlen is NULL.
  */
 int udp_bind_listener(struct listener *listener, char *errmsg, int errlen)
 {
 	__label__ udp_return, udp_close_return;
 	int fd, err;
 	const char *msg = NULL;
 	/* copy listener addr because sometimes we need to switch family */
 	struct sockaddr_storage addr_inet = listener->rx.addr;

 	/* force to classic sock family */
 	addr_inet.ss_family = listener->rx.proto->sock_family;

 	/* ensure we never return garbage */
 	if (errlen)
 		*errmsg = 0;

 	if (listener->state != LI_ASSIGNED)
 		return ERR_NONE; /* already bound */

 	err = ERR_NONE;

 	/* TODO: Implement reuse fd. Take care that to identify fd to reuse
 	 * listeners uses a special AF_CUST_ family and we MUST consider
 	 * IPPROTO (sockaddr is not enough)
 	 */

 	fd = my_socketat(listener->bind_conf->settings.netns,
 	                 listener->rx.proto->sock_family,
 	                 listener->rx.proto->sock_type,
 	                 listener->rx.proto->sock_prot);
 	if (fd == -1) {
 		err |= ERR_RETRYABLE | ERR_ALERT;
 		msg = "cannot create listening socket";
 		goto udp_return;
 	}

 	if (fd >= global.maxsock) {
 		err |= ERR_FATAL | ERR_ABORT | ERR_ALERT;
 		msg = "not enough free sockets (raise '-n' parameter)";
 		goto udp_close_return;
 	}

 	if (fcntl(fd, F_SETFL, O_NONBLOCK) == -1) {
 		err |= ERR_FATAL | ERR_ALERT;
 		msg = "cannot make socket non-blocking";
 		goto udp_close_return;
 	}

 	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) == -1) {
 		/* not fatal but should be reported */
 		msg = "cannot do so_reuseaddr";
 		err |= ERR_ALERT;
 	}

 #ifdef SO_REUSEPORT
 	/* OpenBSD and Linux 3.9 support this. As it's present in old libc versions of
 	 * Linux, it might return an error that we will silently ignore.
 	 */
 	if (global.tune.options & GTUNE_USE_REUSEPORT)
 		setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one));
 #endif

 	if (listener->options & LI_O_FOREIGN) {
 		switch (addr_inet.ss_family) {
 		case AF_INET:
 			if (!sock_inet4_make_foreign(fd)) {
 				msg = "cannot make listening socket transparent";
 				err |= ERR_ALERT;
 			}
 		break;
 		case AF_INET6:
 			if (!sock_inet6_make_foreign(fd)) {
 				msg = "cannot make listening socket transparent";
 				err |= ERR_ALERT;
 			}
 		break;
 		}
 	}

 #ifdef SO_BINDTODEVICE
 	/* Note: this might fail if not CAP_NET_RAW */
 	if (listener->bind_conf->settings.interface) {
 		if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
 		               listener->bind_conf->settings.interface,
 		               strlen(listener->bind_conf->settings.interface) + 1) == -1) {
 			msg = "cannot bind listener to device";
 			err |= ERR_WARN;
 		}
 	}
 #endif
 #if defined(IPV6_V6ONLY)
 	if (listener->options & LI_O_V6ONLY)
                 setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one));
 	else if (listener->options & LI_O_V4V6)
                 setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &zero, sizeof(zero));
 #endif

 	if (bind(fd, (struct sockaddr *)&addr_inet, listener->rx.proto->sock_addrlen) < 0) {
 		err |= ERR_RETRYABLE | ERR_ALERT;
 		msg = "cannot bind socket";
 		goto udp_close_return;
 	}

 	/* the socket is ready */
 	listener->rx.fd = fd;
 	listener->state = LI_LISTEN;

 	if (listener->bind_conf->frontend->mode == PR_MODE_SYSLOG)
 		fd_insert(fd, listener, syslog_fd_handler,
 		          thread_mask(listener->bind_conf->settings.bind_thread) & all_threads_mask);
 	else {
 		err |= ERR_FATAL | ERR_ALERT;
 		msg = "UDP is not yet supported on this proxy mode";
 		goto udp_close_return;
 	}

  udp_return:
 	if (msg && errlen) {
 		char pn[INET6_ADDRSTRLEN];

 		addr_to_str(&addr_inet, pn, sizeof(pn));
 		snprintf(errmsg, errlen, "%s [%s:%d]", msg, pn, get_host_port(&addr_inet));
 	}
 	return err;

  udp_close_return:
 	close(fd);
 	goto udp_return;
 }

 /* Add <listener> to the list of udp4 listeners, on port <port>. The
  * listener's state is automatically updated from LI_INIT to LI_ASSIGNED.
  * The number of listeners for the protocol is updated.
  */
 static void udp4_add_listener(struct listener *listener, int port)
 {
 	if (listener->state != LI_INIT)
 		return;
 	listener->state = LI_ASSIGNED;
 	listener->rx.proto = &proto_udp4;
 	((struct sockaddr_in *)(&listener->rx.addr))->sin_port = htons(port);
 	LIST_ADDQ(&proto_udp4.listeners, &listener->rx.proto_list);
 	proto_udp4.nb_listeners++;
 }

 /* Add <listener> to the list of udp6 listeners, on port <port>. The
  * listener's state is automatically updated from LI_INIT to LI_ASSIGNED.
  * The number of listeners for the protocol is updated.
  */
 static void udp6_add_listener(struct listener *listener, int port)
 {
 	if (listener->state != LI_INIT)
 		return;
 	listener->state = LI_ASSIGNED;
 	listener->rx.proto = &proto_udp6;
 	((struct sockaddr_in *)(&listener->rx.addr))->sin_port = htons(port);
 	LIST_ADDQ(&proto_udp6.listeners, &listener->rx.proto_list);
 	proto_udp6.nb_listeners++;
 }

 /* Pause a listener. Returns < 0 in case of failure, 0 if the listener
  * was totally stopped, or > 0 if correctly paused.
  */
 int udp_pause_listener(struct listener *l)
 {
 	/* we don't support pausing on UDP */
 	return -1;
 }

 /*
  * Local variables:
  *  c-indent-level: 8
  *  c-basic-offset: 8
  * End:
  */
	/*
	* AF_CUST_UDP/AF_CUST_UDP6 UDP protocol layer
	*
	* Copyright 2019 HAProxy Technologies, Frédéric Lécaille <flecaille@haproxy.com>
	*
	* Partial merge by Emeric Brun <ebrun@haproxy.com>
	*
	* 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.
	*
	*/

	#include <ctype.h>
	#include <errno.h>
	#include <fcntl.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <time.h>

	#include <sys/param.h>
	#include <sys/socket.h>
	#include <sys/types.h>

	#include <netinet/udp.h>
	#include <netinet/in.h>

	#include <haproxy/fd.h>
	#include <haproxy/listener.h>
	#include <haproxy/log.h>
	#include <haproxy/namespace.h>
	#include <haproxy/port_range.h>
	#include <haproxy/protocol.h>
	#include <haproxy/proto_udp.h>
	#include <haproxy/proxy.h>
	#include <haproxy/server.h>
	#include <haproxy/sock.h>
	#include <haproxy/sock_inet.h>
	#include <haproxy/task.h>

	static int udp_bind_listener(struct listener listener, char errmsg, int errlen);
	static void udp4_add_listener(struct listener *listener, int port);
	static void udp6_add_listener(struct listener *listener, int port);

	/* Note: must not be declared <const> as its list will be overwritten */
	static struct protocol proto_udp4 = {
	.name = "udp4",
	.sock_domain = AF_CUST_UDP4,
	.sock_type = SOCK_DGRAM,
	.sock_prot = IPPROTO_UDP,
	.sock_family = AF_INET,
	.sock_addrlen = sizeof(struct sockaddr_in),
	.l3_addrlen = 32/8,
	.accept = NULL,
	.connect = NULL,
	.bind = udp_bind_listener,
	.enable_all = enable_all_listeners,
	.get_src = udp_get_src,
	.get_dst = udp_get_dst,
	.pause = udp_pause_listener,
	.add = udp4_add_listener,
	.addrcmp = sock_inet4_addrcmp,
	.listeners = LIST_HEAD_INIT(proto_udp4.listeners),
	.nb_listeners = 0,
	};

	INITCALL1(STG_REGISTER, protocol_register, &proto_udp4);

	/* Note: must not be declared <const> as its list will be overwritten */
	static struct protocol proto_udp6 = {
	.name = "udp6",
	.sock_domain = AF_CUST_UDP6,
	.sock_type = SOCK_DGRAM,
	.sock_prot = IPPROTO_UDP,
	.sock_family = AF_INET6,
	.sock_addrlen = sizeof(struct sockaddr_in6),
	.l3_addrlen = 128/8,
	.accept = NULL,
	.connect = NULL,
	.bind = udp_bind_listener,
	.enable_all = enable_all_listeners,
	.get_src = udp6_get_src,
	.get_dst = udp6_get_dst,
	.pause = udp_pause_listener,
	.add = udp6_add_listener,
	.addrcmp = sock_inet6_addrcmp,
	.listeners = LIST_HEAD_INIT(proto_udp6.listeners),
	.nb_listeners = 0,
	};

	INITCALL1(STG_REGISTER, protocol_register, &proto_udp6);

	/*
	* Retrieves the source address for the socket <fd>, with <dir> indicating
	* if we're a listener (=0) or an initiator (!=0). It returns 0 in case of
	* success, -1 in case of error. The socket's source address is stored in
	* <sa> for <salen> bytes.
	*/
	int udp_get_src(int fd, struct sockaddr *sa, socklen_t salen, int dir)
	{
	int ret;

	ret = sock_get_src(fd, sa, salen, dir);
	if (!ret)
	sa->sa_family = AF_CUST_UDP4;

	return ret;
	}

	/*
	* Retrieves the source address for the socket <fd>, with <dir> indicating
	* if we're a listener (=0) or an initiator (!=0). It returns 0 in case of
	* success, -1 in case of error. The socket's source address is stored in
	* <sa> for <salen> bytes.
	*/
	int udp6_get_src(int fd, struct sockaddr *sa, socklen_t salen, int dir)
	{
	int ret;

	ret = sock_get_src(fd, sa, salen, dir);
	if (!ret)
	sa->sa_family = AF_CUST_UDP6;

	return ret;
	}

	/*
	* Retrieves the original destination address for the socket <fd>, with <dir>
	* indicating if we're a listener (=0) or an initiator (!=0). In the case of a
	* listener, if the original destination address was translated, the original
	* address is retrieved. It returns 0 in case of success, -1 in case of error.
	* The socket's source address is stored in <sa> for <salen> bytes.
	*/
	int udp_get_dst(int fd, struct sockaddr *sa, socklen_t salen, int dir)
	{
	int ret;

	ret = sock_inet_get_dst(fd, sa, salen, dir);
	if (!ret)
	sa->sa_family = AF_CUST_UDP4;

	return ret;
	}

	/*
	* Retrieves the original destination address for the socket <fd>, with <dir>
	* indicating if we're a listener (=0) or an initiator (!=0). In the case of a
	* listener, if the original destination address was translated, the original
	* address is retrieved. It returns 0 in case of success, -1 in case of error.
	* The socket's source address is stored in <sa> for <salen> bytes.
	*/
	int udp6_get_dst(int fd, struct sockaddr *sa, socklen_t salen, int dir)
	{
	int ret;

	ret = sock_get_dst(fd, sa, salen, dir);
	if (!ret)
	sa->sa_family = AF_CUST_UDP6;

	return ret;
	}

	/* This function tries to bind a UDPv4/v6 listener. It may return a warning or
	* an error message in <errmsg> if the message is at most <errlen> bytes long
	* (including '\0'). Note that <errmsg> may be NULL if <errlen> is also zero.
	* The return value is composed from ERR_ABORT, ERR_WARN,
	* ERR_ALERT, ERR_RETRYABLE and ERR_FATAL. ERR_NONE indicates that everything
	* was alright and that no message was returned. ERR_RETRYABLE means that an
	* error occurred but that it may vanish after a retry (eg: port in use), and
	* ERR_FATAL indicates a non-fixable error. ERR_WARN and ERR_ALERT do not alter
	* the meaning of the error, but just indicate that a message is present which
	* should be displayed with the respective level. Last, ERR_ABORT indicates
	* that it's pointless to try to start other listeners. No error message is
	* returned if errlen is NULL.
	*/
	int udp_bind_listener(struct listener listener, char errmsg, int errlen)
	{
	__label__ udp_return, udp_close_return;
	int fd, err;
	const char *msg = NULL;
	/* copy listener addr because sometimes we need to switch family */
	struct sockaddr_storage addr_inet = listener->rx.addr;

	/* force to classic sock family */
	addr_inet.ss_family = listener->rx.proto->sock_family;

	/* ensure we never return garbage */
	if (errlen)
	*errmsg = 0;

	if (listener->state != LI_ASSIGNED)
	return ERR_NONE; /* already bound */

	err = ERR_NONE;

	/* TODO: Implement reuse fd. Take care that to identify fd to reuse
	* listeners uses a special AF_CUST_ family and we MUST consider
	* IPPROTO (sockaddr is not enough)
	*/

	fd = my_socketat(listener->bind_conf->settings.netns,
	listener->rx.proto->sock_family,
	listener->rx.proto->sock_type,
	listener->rx.proto->sock_prot);
	if (fd == -1) {
	err \|= ERR_RETRYABLE \| ERR_ALERT;
	msg = "cannot create listening socket";
	goto udp_return;
	}

	if (fd >= global.maxsock) {
	err \|= ERR_FATAL \| ERR_ABORT \| ERR_ALERT;
	msg = "not enough free sockets (raise '-n' parameter)";
	goto udp_close_return;
	}

	if (fcntl(fd, F_SETFL, O_NONBLOCK) == -1) {
	err \|= ERR_FATAL \| ERR_ALERT;
	msg = "cannot make socket non-blocking";
	goto udp_close_return;
	}

	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) == -1) {
	/* not fatal but should be reported */
	msg = "cannot do so_reuseaddr";
	err \|= ERR_ALERT;
	}

	#ifdef SO_REUSEPORT
	/* OpenBSD and Linux 3.9 support this. As it's present in old libc versions of
	* Linux, it might return an error that we will silently ignore.
	*/
	if (global.tune.options & GTUNE_USE_REUSEPORT)
	setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one));
	#endif

	if (listener->options & LI_O_FOREIGN) {
	switch (addr_inet.ss_family) {
	case AF_INET:
	if (!sock_inet4_make_foreign(fd)) {
	msg = "cannot make listening socket transparent";
	err \|= ERR_ALERT;
	}
	break;
	case AF_INET6:
	if (!sock_inet6_make_foreign(fd)) {
	msg = "cannot make listening socket transparent";
	err \|= ERR_ALERT;
	}
	break;
	}
	}

	#ifdef SO_BINDTODEVICE
	/* Note: this might fail if not CAP_NET_RAW */
	if (listener->bind_conf->settings.interface) {
	if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
	listener->bind_conf->settings.interface,
	strlen(listener->bind_conf->settings.interface) + 1) == -1) {
	msg = "cannot bind listener to device";
	err \|= ERR_WARN;
	}
	}
	#endif
	#if defined(IPV6_V6ONLY)
	if (listener->options & LI_O_V6ONLY)
	setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one));
	else if (listener->options & LI_O_V4V6)
	setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &zero, sizeof(zero));
	#endif

	if (bind(fd, (struct sockaddr *)&addr_inet, listener->rx.proto->sock_addrlen) < 0) {
	err \|= ERR_RETRYABLE \| ERR_ALERT;
	msg = "cannot bind socket";
	goto udp_close_return;
	}

	/* the socket is ready */
	listener->rx.fd = fd;
	listener->state = LI_LISTEN;

	if (listener->bind_conf->frontend->mode == PR_MODE_SYSLOG)
	fd_insert(fd, listener, syslog_fd_handler,
	thread_mask(listener->bind_conf->settings.bind_thread) & all_threads_mask);
	else {
	err \|= ERR_FATAL \| ERR_ALERT;
	msg = "UDP is not yet supported on this proxy mode";
	goto udp_close_return;
	}

	udp_return:
	if (msg && errlen) {
	char pn[INET6_ADDRSTRLEN];

	addr_to_str(&addr_inet, pn, sizeof(pn));
	snprintf(errmsg, errlen, "%s [%s:%d]", msg, pn, get_host_port(&addr_inet));
	}
	return err;

	udp_close_return:
	close(fd);
	goto udp_return;
	}

	/* Add <listener> to the list of udp4 listeners, on port <port>. The
	* listener's state is automatically updated from LI_INIT to LI_ASSIGNED.
	* The number of listeners for the protocol is updated.
	*/
	static void udp4_add_listener(struct listener *listener, int port)
	{
	if (listener->state != LI_INIT)
	return;
	listener->state = LI_ASSIGNED;
	listener->rx.proto = &proto_udp4;
	((struct sockaddr_in *)(&listener->rx.addr))->sin_port = htons(port);
	LIST_ADDQ(&proto_udp4.listeners, &listener->rx.proto_list);
	proto_udp4.nb_listeners++;
	}

	/* Add <listener> to the list of udp6 listeners, on port <port>. The
	* listener's state is automatically updated from LI_INIT to LI_ASSIGNED.
	* The number of listeners for the protocol is updated.
	*/
	static void udp6_add_listener(struct listener *listener, int port)
	{
	if (listener->state != LI_INIT)
	return;
	listener->state = LI_ASSIGNED;
	listener->rx.proto = &proto_udp6;
	((struct sockaddr_in *)(&listener->rx.addr))->sin_port = htons(port);
	LIST_ADDQ(&proto_udp6.listeners, &listener->rx.proto_list);
	proto_udp6.nb_listeners++;
	}

	/* Pause a listener. Returns < 0 in case of failure, 0 if the listener
	* was totally stopped, or > 0 if correctly paused.
	*/
	int udp_pause_listener(struct listener *l)
	{
	/* we don't support pausing on UDP */
	return -1;
	}

	/*
	* Local variables:
	* c-indent-level: 8
	* c-basic-offset: 8
	* End:
	*/