owfd: dhcp: add dhcp helpers skeleton

All known dhcp daemons have horrible interfaces if you want to use them
for short-lived ad-hoc networks like Wifi-P2P. Therefore, we use our own
helper with gdhcp as DHCP implementation.

openwfd_dhcp implements a DHCP server and daemon. Depending in the given
command-line argument, it is run as either. All configuration parameters
are passed via command-line.

Note that openwfd_dhcp is a workaround and should only be used as such.
Once network-managers pick up proper Wifi-P2P APIs, we can remove
openwfd_p2pd (including openwfd_dhcp) and start using their APIs. Until
then, we need this small hack.

This patch only adds the dhcp skeleton. No real functionality is added,
yet.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>

6 files changed, 657 insertions, 1 deletions

diff --git a/.gitignore b/.gitignore
index d50f367..c371dc8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,6 +21,7 @@ config.status
 configure
 libtool
 m4/
+openwfd_dhcp
 openwfd_ie
 openwfd_p2pd
 stamp-h1
diff --git a/Makefile.am b/Makefile.am
index d1aa135..6f78a38 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -62,7 +62,8 @@ AM_LDFLAGS = \
 
 AM_CPPFLAGS += \
 	-DBUILD_ENABLE_DEBUG \
-	"-DBUILD_BINDIR_WPA_SUPPLICANT=\"/bin\""
+	"-DBUILD_BINDIR_WPA_SUPPLICANT=\"/bin\"" \
+	"-DBUILD_BINDIR_IP=\"/bin\""
 
 #
 # SHL - Static Helper Library
@@ -142,6 +143,27 @@ openwfd_p2pd_LDADD = \
 openwfd_p2pd_LDFLAGS = $(AM_LDFLAGS)
 
 #
+# openwfd_dhcp
+#
+
+bin_PROGRAMS += openwfd_dhcp
+
+openwfd_dhcp_SOURCES = \
+	src/dhcp.h \
+	src/dhcp.c \
+	src/dhcp_config.c
+
+openwfd_dhcp_CPPFLAGS = \
+	$(AM_CPPFLAGS) \
+	$(DHCP_CFLAGS)
+openwfd_dhcp_LDADD = \
+	$(DHCP_LIBS) \
+	libgdhcp.la \
+	libowfd.la \
+	libshl.la
+openwfd_dhcp_LDFLAGS = $(AM_LDFLAGS)
+
+#
 # Tools
 #
 
diff --git a/configure.ac b/configure.ac
index d1f635f..7883ba3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -45,6 +45,14 @@ AC_SUBST(GDHCP_CFLAGS)
 AC_SUBST(GDHCP_LIBS)
 
 #
+# Test for dhcp dependencies
+#
+
+PKG_CHECK_MODULES([DHCP], [glib-2.0])
+AC_SUBST(DHCP_CFLAGS)
+AC_SUBST(DHCP_LIBS)
+
+#
 # Test for "check" which we use for our test-suite. If not found, we disable
 # all tests.
 #
diff --git a/src/dhcp.c b/src/dhcp.c
new file mode 100644
index 0000000..3894563
--- /dev/null
+++ b/src/dhcp.c
@@ -0,0 +1,205 @@
+/*
+ * OpenWFD - Open-Source Wifi-Display Implementation
+ *
+ * Copyright (c) 2013 David Herrmann <dh.herrmann@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <arpa/inet.h>
+#include <errno.h>
+#include <glib.h>
+#include <netinet/in.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/epoll.h>
+#include <sys/signalfd.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include "dhcp.h"
+#include "gdhcp/gdhcp.h"
+#include "shl_log.h"
+
+struct owfd_dhcp {
+	struct owfd_dhcp_config config;
+	GMainLoop *loop;
+
+	int sfd;
+	GIOChannel *sfd_chan;
+	guint sfd_id;
+};
+
+static gboolean owfd_dhcp_sfd_fn(GIOChannel *chan, GIOCondition mask,
+				 gpointer data)
+{
+	struct owfd_dhcp *dhcp = data;
+	ssize_t l;
+	struct signalfd_siginfo info;
+
+	if (mask & (G_IO_HUP | G_IO_ERR)) {
+		log_vEPIPE();
+		g_main_loop_quit(dhcp->loop);
+		return FALSE;
+	}
+
+	l = read(dhcp->sfd, &info, sizeof(info));
+	if (l < 0) {
+		log_vERRNO();
+		g_main_loop_quit(dhcp->loop);
+		return FALSE;
+	} else if (l != sizeof(info)) {
+		log_vEFAULT();
+		return TRUE;
+	}
+
+	log_notice("received signal %d: %s",
+		   info.ssi_signo, strsignal(info.ssi_signo));
+
+	g_main_loop_quit(dhcp->loop);
+	return FALSE;
+}
+
+static int owfd_dhcp_run(struct owfd_dhcp *dhcp)
+{
+	g_main_loop_run(dhcp->loop);
+
+	return 0;
+}
+
+static void owfd_dhcp_teardown(struct owfd_dhcp *dhcp)
+{
+	if (dhcp->sfd >= 0) {
+		g_source_remove(dhcp->sfd_id);
+		g_io_channel_unref(dhcp->sfd_chan);
+		close(dhcp->sfd);
+	}
+
+	if (dhcp->loop)
+		g_main_loop_unref(dhcp->loop);
+}
+
+static void sig_dummy(int sig)
+{
+}
+
+static int owfd_dhcp_setup(struct owfd_dhcp *dhcp)
+{
+	static const int sigs[] = {
+		SIGINT,
+		SIGTERM,
+		SIGQUIT,
+		SIGHUP,
+		SIGPIPE,
+		0
+	};
+	int r, i;
+	sigset_t mask;
+	struct sigaction sig;
+
+	dhcp->loop = g_main_loop_new(NULL, FALSE);
+
+	sigemptyset(&mask);
+	memset(&sig, 0, sizeof(sig));
+	sig.sa_handler = sig_dummy;
+	sig.sa_flags = SA_RESTART;
+
+	for (i = 0; sigs[i]; ++i) {
+		sigaddset(&mask, sigs[i]);
+		r = sigaction(sigs[i], &sig, NULL);
+		if (r < 0) {
+			r = log_ERRNO();
+			goto error;
+		}
+	}
+
+	r = sigprocmask(SIG_BLOCK, &mask, NULL);
+	if (r < 0) {
+		r = log_ERRNO();
+		goto error;
+	}
+
+	dhcp->sfd = signalfd(-1, &mask, SFD_CLOEXEC | SFD_NONBLOCK);
+	if (dhcp->sfd < 0) {
+		r = log_ERRNO();
+		goto error;
+	}
+
+	dhcp->sfd_chan = g_io_channel_unix_new(dhcp->sfd);
+	dhcp->sfd_id = g_io_add_watch(dhcp->sfd_chan,
+				      G_IO_HUP | G_IO_ERR | G_IO_IN,
+				      owfd_dhcp_sfd_fn,
+				      dhcp);
+
+	return 0;
+
+error:
+	owfd_dhcp_teardown(dhcp);
+	return r;
+}
+
+int main(int argc, char **argv)
+{
+	struct owfd_dhcp dhcp;
+	int r;
+
+	memset(&dhcp, 0, sizeof(dhcp));
+	dhcp.sfd = -1;
+	owfd_dhcp_init_config(&dhcp.config);
+
+	r = owfd_dhcp_parse_argv(&dhcp.config, argc, argv);
+	if (r < 0)
+		goto err_out;
+
+	if (dhcp.config.debug)
+		log_max_sev = LOG_DEBUG;
+	else if (dhcp.config.verbose)
+		log_max_sev = LOG_INFO;
+	else if (dhcp.config.silent)
+		log_max_sev = LOG_ERROR;
+
+	if (dhcp.config.silent)
+		log_debug("-");
+	else
+		log_format(LOG_DEFAULT_BASE, NULL, LOG_SEV_NUM,
+			   "openwfd_dhcp - revision %s %s %s",
+			   "some-rev-TODO-xyz", __DATE__, __TIME__);
+
+	log_info("initializing");
+	r = owfd_dhcp_setup(&dhcp);
+	if (r < 0)
+		goto err_conf;
+
+	log_info("running");
+	r = owfd_dhcp_run(&dhcp);
+
+	owfd_dhcp_teardown(&dhcp);
+err_conf:
+	owfd_dhcp_clear_config(&dhcp.config);
+	if (r < 0) {
+		errno = -r;
+		log_error("initialization failed (%d): %m", r);
+	}
+	log_info("exiting");
+err_out:
+	return -r;
+}
diff --git a/src/dhcp.h b/src/dhcp.h
new file mode 100644
index 0000000..64aa261
--- /dev/null
+++ b/src/dhcp.h
@@ -0,0 +1,66 @@
+/*
+ * OpenWFD - Open-Source Wifi-Display Implementation
+ *
+ * Copyright (c) 2013 David Herrmann <dh.herrmann@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef OWFD_DHCP_H
+#define OWFD_DHCP_H
+
+#include <stdbool.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* config handling */
+
+struct owfd_dhcp_config {
+	unsigned int verbose : 1;
+	unsigned int silent : 1;
+	unsigned int debug : 1;
+
+	unsigned int client : 1;
+	unsigned int server : 1;
+
+	char *interface;
+	char *ip_binary;
+
+	char *local;
+	char *gateway;
+	char *dns;
+	char *subnet;
+	char *ip_from;
+	char *ip_to;
+};
+
+void owfd_dhcp_init_config(struct owfd_dhcp_config *conf);
+void owfd_dhcp_clear_config(struct owfd_dhcp_config *conf);
+int owfd_dhcp_parse_argv(struct owfd_dhcp_config *conf,
+			 int argc, char **argv);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* OWFD_DHCP_H */
diff --git a/src/dhcp_config.c b/src/dhcp_config.c
new file mode 100644
index 0000000..28d050c
--- /dev/null
+++ b/src/dhcp_config.c
@@ -0,0 +1,354 @@
+/*
+ * OpenWFD - Open-Source Wifi-Display Implementation
+ *
+ * Copyright (c) 2013 David Herrmann <dh.herrmann@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <arpa/inet.h>
+#include <errno.h>
+#include <getopt.h>
+#include <netinet/in.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include "dhcp.h"
+
+#define LONG_OPT_OFFSET 10000
+
+enum {
+	OPT_HELP,
+	OPT_VERBOSE,
+	OPT_SILENT,
+	OPT_DEBUG,
+
+	OPT_CLIENT,
+	OPT_SERVER,
+
+	OPT_INTERFACE,
+	OPT_IP_BINARY,
+
+	OPT_LOCAL,
+	OPT_GATEWAY,
+	OPT_DNS,
+	OPT_SUBNET,
+	OPT_IP_FROM,
+	OPT_IP_TO,
+};
+
+const char short_options[] = ":hvcsi:";
+
+#define OPT(_name, _arg, _val) \
+	{ .name = _name, .has_arg = _arg, .val = LONG_OPT_OFFSET + _val }
+const struct option long_options[] = {
+	OPT("help", 0, OPT_HELP),
+	OPT("verbose", 0, OPT_VERBOSE),
+	OPT("silent", 0, OPT_SILENT),
+	OPT("debug", 0, OPT_DEBUG),
+
+	OPT("client", 0, OPT_CLIENT),
+	OPT("server", 0, OPT_SERVER),
+
+	OPT("interface", 1, OPT_INTERFACE),
+	OPT("ip-binary", 1, OPT_IP_BINARY),
+
+	OPT("local", 1, OPT_LOCAL),
+	OPT("gateway", 1, OPT_GATEWAY),
+	OPT("dns", 1, OPT_DNS),
+	OPT("subnet", 1, OPT_SUBNET),
+	OPT("ip-from", 1, OPT_IP_FROM),
+	OPT("ip-to", 1, OPT_IP_TO),
+
+	OPT(NULL, 0, 0),
+};
+#undef OPT
+
+void owfd_dhcp_init_config(struct owfd_dhcp_config *conf)
+{
+	memset(conf, 0, sizeof(*conf));
+}
+
+void owfd_dhcp_clear_config(struct owfd_dhcp_config *conf)
+{
+	free(conf->interface);
+	free(conf->ip_binary);
+
+	free(conf->local);
+	free(conf->gateway);
+	free(conf->dns);
+	free(conf->subnet);
+	free(conf->ip_from);
+	free(conf->ip_to);
+}
+
+static void show_help(void)
+{
+	/*
+	 * Usage/Help information
+	 * This should be scaled to a maximum of 80 characters per line:
+	 *
+	 * 80 char line:
+	 *       |   10   |    20   |    30   |    40   |    50   |    60   |    70   |    80   |
+	 *      "12345678901234567890123456789012345678901234567890123456789012345678901234567890\n"
+	 * 80 char line starting with tab:
+	 *       |10|    20   |    30   |    40   |    50   |    60   |    70   |    80   |
+	 *      "\t901234567890123456789012345678901234567890123456789012345678901234567890\n"
+	 */
+	fprintf(stderr,
+		"Usage:\n"
+		"\t%1$s [options]\n"
+		"\t%1$s -h [options]\n"
+		"\n"
+		"All addresses must be given as IPv6 address. If you want to pass an IPv4\n"
+		"address, use '::FFFF:<ipv4>' as usual.\n"
+		"\n"
+		"General Options:\n"
+		"\t-h, --help                  [off]   Print this help and exit\n"
+		"\t-v, --verbose               [off]   Print verbose messages\n"
+		"\t    --debug                 [off]   Enable debug mode\n"
+		"\t    --silent                [off]   Suppress notices and warnings\n"
+		"\n"
+		"Modus Options:\n"
+		"\t-c, --client                [off]   Run as DHCP client\n"
+		"\t-s, --server                [off]   Run as DHCP server\n"
+		"\n"
+		"Network Options:\n"
+		"\t-i, --interface <wlan0>     []      Wireless interface to run on\n"
+		"\t    --ip-binary </path>     [%2$s]\n"
+		"\t                                    Path to 'ip' binary\n"
+		"\n"
+		"Server Options:\n"
+		"\t    --local <addr>          []      Local IPv6 address\n"
+		"\t    --gateway <addr>        []      Gateway IPv6 address\n"
+		"\t    --dns <addr>            []      DNS-Server IPv6 address\n"
+		"\t    --subnet <mask>         []      Subnet mask\n"
+		"\t    --ip-from <addr>        []      Server IPv6-range start address\n"
+		"\t    --ip-to <addr>          []      Server IPv6-range end address\n"
+		, "openwfd_dhcp",
+		BUILD_BINDIR_IP "/ip");
+	/*
+	 * 80 char line:
+	 *       |   10   |    20   |    30   |    40   |    50   |    60   |    70   |    80   |
+	 *      "12345678901234567890123456789012345678901234567890123456789012345678901234567890\n"
+	 * 80 char line starting with tab:
+	 *       |10|    20   |    30   |    40   |    50   |    60   |    70   |    80   |
+	 *      "\t901234567890123456789012345678901234567890123456789012345678901234567890\n"
+	 */
+}
+
+static int OOM(void)
+{
+	fprintf(stderr, "out of memory\n");
+	return -ENOMEM;
+}
+
+static int verify_address(const char *argname, const char *argval)
+{
+	int r;
+	struct in6_addr addr;
+
+	if (!argval) {
+		fprintf(stderr, "no value given for %s\n", argname);
+		return -EINVAL;
+	}
+
+	r = inet_pton(AF_INET6, argval, &addr);
+	if (r != 1) {
+		fprintf(stderr, "invalid IPv6 address for %s\n", argname);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int owfd_dhcp_parse_argv(struct owfd_dhcp_config *conf, int argc, char **argv)
+{
+	int c;
+	bool help = false;
+	char *t;
+	int r;
+
+	opterr = 0;
+	while (1) {
+		c = getopt_long(argc, argv, short_options, long_options, NULL);
+		if (c <= 0) {
+			break;
+		} else if (c == ':') {
+			fprintf(stderr, "missing argument for: %s\n",
+				argv[optind - 1]);
+			return -EINVAL;
+		} else if (c == '?') {
+			if (optopt && optopt < LONG_OPT_OFFSET)
+				fprintf(stderr, "unknown argument: -%c\n",
+					optopt);
+			else if (!optopt)
+				fprintf(stderr, "unknown argument: %s\n",
+					argv[optind - 1]);
+			else
+				fprintf(stderr, "option takes no arg: %s\n",
+					argv[optind - 1]);
+			return -EINVAL;
+		}
+
+#define OPT(_num) LONG_OPT_OFFSET + _num
+		switch (c) {
+		case 'h':
+		case OPT(OPT_HELP):
+			help = true;
+			break;
+		case 'v':
+		case OPT(OPT_VERBOSE):
+			conf->verbose = 1;
+			break;
+		case OPT(OPT_SILENT):
+			conf->silent = 1;
+			break;
+		case OPT(OPT_DEBUG):
+			conf->debug = 1;
+			break;
+
+		case 'c':
+		case OPT(OPT_CLIENT):
+			conf->server = 0;
+			conf->client = 1;
+			break;
+		case 's':
+		case OPT(OPT_SERVER):
+			conf->client = 0;
+			conf->server = 1;
+			break;
+
+		case 'i':
+		case OPT(OPT_INTERFACE):
+			t = strdup(optarg);
+			if (!t)
+				return OOM();
+			free(conf->interface);
+			conf->interface = t;
+			break;
+		case OPT(OPT_IP_BINARY):
+			t = strdup(optarg);
+			if (!t)
+				return OOM();
+			free(conf->ip_binary);
+			conf->ip_binary = t;
+			break;
+
+		case OPT(OPT_LOCAL):
+			t = strdup(optarg);
+			if (!t)
+				return OOM();
+			free(conf->local);
+			conf->local = t;
+			break;
+		case OPT(OPT_GATEWAY):
+			t = strdup(optarg);
+			if (!t)
+				return OOM();
+			free(conf->gateway);
+			conf->gateway = t;
+			break;
+		case OPT(OPT_DNS):
+			t = strdup(optarg);
+			if (!t)
+				return OOM();
+			free(conf->dns);
+			conf->dns = t;
+			break;
+		case OPT(OPT_SUBNET):
+			t = strdup(optarg);
+			if (!t)
+				return OOM();
+			free(conf->subnet);
+			conf->subnet = t;
+			break;
+		case OPT(OPT_IP_FROM):
+			t = strdup(optarg);
+			if (!t)
+				return OOM();
+			free(conf->ip_from);
+			conf->ip_from = t;
+			break;
+		case OPT(OPT_IP_TO):
+			t = strdup(optarg);
+			if (!t)
+				return OOM();
+			free(conf->ip_to);
+			conf->ip_to = t;
+			break;
+		}
+#undef OPT
+	}
+
+	if (help) {
+		show_help();
+		return -EAGAIN;
+	}
+
+	if (optind < argc) {
+		fprintf(stderr,
+			"unparsed remaining arguments starting with: %s\n",
+			argv[optind]);
+		return -EINVAL;
+	}
+
+	if (!conf->client && !conf->server) {
+		fprintf(stderr,
+			"no --client or --server given\n");
+		return -EINVAL;
+	}
+
+	if (!conf->interface) {
+		fprintf(stderr, "no interface given, use: -i <iface>\n");
+		return -EINVAL;
+	}
+
+	if (!conf->ip_binary) {
+		conf->ip_binary = strdup(BUILD_BINDIR_IP "/ip");
+		if (!conf->ip_binary)
+			return OOM();
+	}
+
+	if (conf->server) {
+		r = verify_address("--local", conf->local);
+		if (r < 0)
+			return r;
+		r = verify_address("--gateway", conf->gateway);
+		if (r < 0)
+			return r;
+		r = verify_address("--dns", conf->dns);
+		if (r < 0)
+			return r;
+		r = verify_address("--subnet", conf->subnet);
+		if (r < 0)
+			return r;
+		r = verify_address("--ip-from", conf->ip_from);
+		if (r < 0)
+			return r;
+		r = verify_address("--ip-to", conf->ip_to);
+		if (r < 0)
+			return r;
+	}
+
+	return 0;
+}