1 files changed, 270 insertions, 5 deletions

diff --git a/src/nat/gnunet-nat-server.c b/src/nat/gnunet-nat-server.c
index c1f1be668..ae831db08 100644
--- a/src/nat/gnunet-nat-server.c
+++ b/src/nat/gnunet-nat-server.c
@@ -1,6 +1,6 @@
 /*
      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
@@ -26,11 +26,220 @@
  */
 #include "platform.h"
 #include "gnunet_util_lib.h"
+#include "gnunet_nat_lib.h"
+#include "gnunet_protocols.h"
+#include "nat.h"
 
 /**
- * Should we print some debug output?
+ * Our server.
  */
-#define VERBOSE 0
+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;
+
+  h = GNUNET_NAT_register (cfg,
+                           is_tcp,
+                           dport,
+                           0, NULL, NULL,
+                           NULL, NULL, NULL);
+  memset (&sa, 0, sizeof (sa));
+#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 ctx 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_WARNING, "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_ivp4 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_UNIX, SOCK_STREAM, 0);
+  if (NULL == s)
+    {
+      GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "socket");
+      return;
+    }
+  memset (&sa, 0, sizeof (sa));
+#if HAVE_SOCKADDR_IN_SIN_LEN
+  sa.sin_len = sizeof (sa);
+#endif
+  sa.sin_addr.s_addr = dst_ipv4; 
+  sa.sin_port = htons (dport);
+  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_malloc (sizeof (struct TcpContext));
+  ctx->s = s;
+  ctx->data = data;
+  GNUNET_SCHEDULER_add_write_net (GNUNET_TIME_UNIT_SECONDS,
+                                  s,
+                                  &tcp_send, ctx);
+}
+
+
+/**
+ * Try to send 'data' to the
+ * IP 'dst_ipv4' at port 'dport' via UDP.
+ * 
+ * @param dst_ivp4 target IP
+ * @param dport target port
+ * @param data data to send
+ */
+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_UNIX, SOCK_DGRAM, 0);
+  if (NULL == s)
+    {
+      GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "socket");
+      return;
+    }
+  memset (&sa, 0, sizeof (sa));
+#if HAVE_SOCKADDR_IN_SIN_LEN
+  sa.sin_len = sizeof (sa);
+#endif
+  sa.sin_addr.s_addr = dst_ipv4; 
+  sa.sin_port = htons (dport);
+  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;
+
+  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 ctx 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.
@@ -44,11 +253,67 @@ static void
 run (void *cls,
      char *const *args,
      const char *cfgfile,
-     const struct GNUNET_CONFIGURATION_Handle * c)
+     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!\n"));
+      return;
+    }
+  memset (&in4, 0, sizeof (in4)); 
+  memset (&in6, 0, sizeof (in6)); 
+  in4.sin_port = htons ((uint16_t) port);
+  in6.sin6_port = htons ((uint16_t) port);
+#if HAVE_SOCKADDR_IN_SIN_LEN
+  in4.sin_len = sizeof (in);
+  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[])
 {
@@ -58,7 +323,7 @@ main (int argc, char *const argv[])
 
   if (GNUNET_OK !=
       GNUNET_PROGRAM_run (argc, argv, 
-                          "gnunet-nat-server", 
+                          "gnunet-nat-server [options] PORT", 
                           _("GNUnet NAT traversal test helper daemon"), 
                           options,
                           &run, NULL))