/*
This file is part of GNUnet.
- (C) 2010 Christian Grothoff (and other contributing authors)
+ (C) 2011 Christian Grothoff (and other contributing authors)
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
* @file src/nat/gnunet-nat-server.c
* @brief Daemon to run on 'gnunet.org' to help test NAT traversal code
* @author Christian Grothoff
- *
*/
#include "platform.h"
#include "gnunet_util_lib.h"
+#include "gnunet_nat_lib.h"
+#include "gnunet_protocols.h"
+#include "nat.h"
+
+
+/**
+ * Our server.
+ */
+static struct GNUNET_SERVER_Handle *server;
+
+/**
+ * Our configuration.
+ */
+static const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+
+/**
+ * Try contacting the peer using autonomous
+ * NAT traveral method.
+ *
+ * @param dst_ipv4 IPv4 address to send the fake ICMP message
+ * @param dport destination port to include in ICMP message
+ * @param is_tcp mark for TCP (GNUNET_YES) or UDP (GNUNET_NO)
+ */
+static void
+try_anat (uint32_t dst_ipv4, uint16_t dport, int is_tcp)
+{
+ struct GNUNET_NAT_Handle *h;
+ struct sockaddr_in sa;
+
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Asking for connection reversal with %x and code %u\n",
+ (unsigned int) dst_ipv4, (unsigned int) dport);
+ h = GNUNET_NAT_register (cfg, is_tcp, dport, 0, NULL, NULL, NULL, NULL, NULL);
+ memset (&sa, 0, sizeof (sa));
+ sa.sin_family = AF_INET;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ sa.sin_len = sizeof (sa);
+#endif
+ sa.sin_addr.s_addr = dst_ipv4;
+ GNUNET_NAT_run_client (h, &sa);
+ GNUNET_NAT_unregister (h);
+}
+
+
+/**
+ * Closure for 'tcp_send'.
+ */
+struct TcpContext
+{
+ /**
+ * TCP socket.
+ */
+ struct GNUNET_NETWORK_Handle *s;
+
+ /**
+ * Data to transmit.
+ */
+ uint16_t data;
+};
+
+
+/**
+ * Task called by the scheduler once we can do the TCP send
+ * (or once we failed to connect...).
+ *
+ * @param cls the 'struct TcpContext'
+ * @param tc scheduler context
+ */
+static void
+tcp_send (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+ struct TcpContext *ctx = cls;
+
+ if ((NULL != tc->write_ready) &&
+ (GNUNET_NETWORK_fdset_isset (tc->write_ready, ctx->s)))
+ {
+ if (-1 ==
+ GNUNET_NETWORK_socket_send (ctx->s, &ctx->data, sizeof (ctx->data)))
+ {
+ GNUNET_log_strerror (GNUNET_ERROR_TYPE_DEBUG, "send");
+ }
+ GNUNET_NETWORK_socket_shutdown (ctx->s, SHUT_RDWR);
+ }
+ GNUNET_NETWORK_socket_close (ctx->s);
+ GNUNET_free (ctx);
+}
+
+
+/**
+ * Try to send 'data' to the
+ * IP 'dst_ipv4' at port 'dport' via TCP.
+ *
+ * @param dst_ipv4 target IP
+ * @param dport target port
+ * @param data data to send
+ */
+static void
+try_send_tcp (uint32_t dst_ipv4, uint16_t dport, uint16_t data)
+{
+ struct GNUNET_NETWORK_Handle *s;
+ struct sockaddr_in sa;
+ struct TcpContext *ctx;
+
+ s = GNUNET_NETWORK_socket_create (AF_INET, SOCK_STREAM, 0);
+ if (NULL == s)
+ {
+ GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "socket");
+ return;
+ }
+ memset (&sa, 0, sizeof (sa));
+ sa.sin_family = AF_INET;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ sa.sin_len = sizeof (sa);
+#endif
+ sa.sin_addr.s_addr = dst_ipv4;
+ sa.sin_port = htons (dport);
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sending TCP message to `%s'\n",
+ GNUNET_a2s ((struct sockaddr *) &sa, sizeof (sa)));
+ if ((GNUNET_OK !=
+ GNUNET_NETWORK_socket_connect (s, (const struct sockaddr *) &sa,
+ sizeof (sa))) && (errno != EINPROGRESS))
+ {
+ GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "connect");
+ GNUNET_NETWORK_socket_close (s);
+ return;
+ }
+ ctx = GNUNET_new (struct TcpContext);
+ ctx->s = s;
+ ctx->data = data;
+ GNUNET_SCHEDULER_add_write_net (GNUNET_TIME_UNIT_SECONDS, s, &tcp_send, ctx);
+}
+
/**
- * Should we print some debug output?
+ * Try to send 'data' to the
+ * IP 'dst_ipv4' at port 'dport' via UDP.
+ *
+ * @param dst_ipv4 target IP
+ * @param dport target port
+ * @param data data to send
*/
-#define VERBOSE 0
+static void
+try_send_udp (uint32_t dst_ipv4, uint16_t dport, uint16_t data)
+{
+ struct GNUNET_NETWORK_Handle *s;
+ struct sockaddr_in sa;
+
+ s = GNUNET_NETWORK_socket_create (AF_INET, SOCK_DGRAM, 0);
+ if (NULL == s)
+ {
+ GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "socket");
+ return;
+ }
+ memset (&sa, 0, sizeof (sa));
+ sa.sin_family = AF_INET;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ sa.sin_len = sizeof (sa);
+#endif
+ sa.sin_addr.s_addr = dst_ipv4;
+ sa.sin_port = htons (dport);
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sending UDP packet to `%s'\n",
+ GNUNET_a2s ((struct sockaddr *) &sa, sizeof (sa)));
+ if (-1 ==
+ GNUNET_NETWORK_socket_sendto (s, &data, sizeof (data),
+ (const struct sockaddr *) &sa, sizeof (sa)))
+ GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "sendto");
+ GNUNET_NETWORK_socket_close (s);
+}
+
+
+/**
+ * We've received a request to probe a NAT
+ * traversal. Do it.
+ *
+ * @param cls unused
+ * @param client handle to client (we always close)
+ * @param msg message with details about what to test
+ */
+static void
+test (void *cls, struct GNUNET_SERVER_Client *client,
+ const struct GNUNET_MessageHeader *msg)
+{
+ const struct GNUNET_NAT_TestMessage *tm;
+ uint16_t dport;
+
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received test request\n");
+ tm = (const struct GNUNET_NAT_TestMessage *) msg;
+ dport = ntohs (tm->dport);
+ if (0 == dport)
+ try_anat (tm->dst_ipv4, ntohs (tm->data), (int) ntohl (tm->is_tcp));
+ else if (GNUNET_YES == ntohl (tm->is_tcp))
+ try_send_tcp (tm->dst_ipv4, dport, tm->data);
+ else
+ try_send_udp (tm->dst_ipv4, dport, tm->data);
+ GNUNET_SERVER_receive_done (client, GNUNET_NO);
+}
+
+
+/**
+ * Task run during shutdown.
+ *
+ * @param cls unused
+ * @param tc scheduler context
+ */
+static void
+shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+ GNUNET_SERVER_destroy (server);
+ server = NULL;
+}
+
/**
* Main function that will be run.
* @param c configuration
*/
static void
-run (void *cls,
- char *const *args,
- const char *cfgfile,
- const struct GNUNET_CONFIGURATION_Handle * c)
+run (void *cls, char *const *args, const char *cfgfile,
+ const struct GNUNET_CONFIGURATION_Handle *c)
{
+ static const struct GNUNET_SERVER_MessageHandler handlers[] = {
+ {&test, NULL, GNUNET_MESSAGE_TYPE_NAT_TEST,
+ sizeof (struct GNUNET_NAT_TestMessage)},
+ {NULL, NULL, 0, 0}
+ };
+ unsigned int port;
+ struct sockaddr_in in4;
+ struct sockaddr_in6 in6;
+
+ socklen_t slen[] = {
+ sizeof (in4),
+ sizeof (in6),
+ 0
+ };
+ struct sockaddr *sa[] = {
+ (struct sockaddr *) &in4,
+ (struct sockaddr *) &in6,
+ NULL
+ };
+
+ cfg = c;
+ if ((args[0] == NULL) || (1 != SSCANF (args[0], "%u", &port)) || (0 == port)
+ || (65536 <= port))
+ {
+ FPRINTF (stderr,
+ _
+ ("Please pass valid port number as the first argument! (got `%s')\n"),
+ args[0]);
+ return;
+ }
+ memset (&in4, 0, sizeof (in4));
+ memset (&in6, 0, sizeof (in6));
+ in4.sin_family = AF_INET;
+ in4.sin_port = htons ((uint16_t) port);
+ in6.sin6_family = AF_INET6;
+ in6.sin6_port = htons ((uint16_t) port);
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ in4.sin_len = sizeof (in4);
+ in6.sin6_len = sizeof (in6);
+#endif
+ server =
+ GNUNET_SERVER_create (NULL, NULL, (struct sockaddr * const *) sa, slen,
+ GNUNET_TIME_UNIT_SECONDS, GNUNET_YES);
+ GNUNET_SERVER_add_handlers (server, handlers);
+ GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &shutdown_task,
+ NULL);
}
+/**
+ * Main function of gnunet-nat-server.
+ *
+ * @param argc number of command-line arguments
+ * @param argv command line
+ * @return 0 on success, -1 on error
+ */
int
main (int argc, char *const argv[])
{
GNUNET_GETOPT_OPTION_END
};
+ if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv, &argc, &argv))
+ return 2;
+
if (GNUNET_OK !=
- GNUNET_PROGRAM_run (argc, argv,
- "gnunet-nat-server",
- _("GNUnet NAT traversal test helper daemon"),
- options,
- &run, NULL))
+ GNUNET_PROGRAM_run (argc, argv, "gnunet-nat-server [options] PORT",
+ _("GNUnet NAT traversal test helper daemon"), options,
+ &run, NULL))
+ {
+ GNUNET_free ((void*) argv);
return 1;
+ }
+ GNUNET_free ((void*) argv);
return 0;
}