From: Christian Grothoff <christian@grothoff.org>
Date: Mon, 24 Oct 2016 20:16:19 +0000 (+0000)
Subject: working towards new NAT client library implementation
X-Git-Tag: initial-import-from-subversion-38251~59
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=0cda05a0cbbe53f97f74062cbd3fedca7d602925;p=oweals%2Fgnunet.git

working towards new NAT client library implementation
---

diff --git a/src/nat/nat_api.c b/src/nat/nat_api.c
index 6488fdf88..e7320eb50 100644
--- a/src/nat/nat_api.c
+++ b/src/nat/nat_api.c
@@ -28,6 +28,31 @@
  */
 #include "platform.h"
 #include "gnunet_nat_service.h"
+#include "nat.h"
+#include "nat_stun.h"
+
+
+/**
+ * Entry in DLL of addresses of this peer.
+ */
+struct AddrEntry
+{
+
+  /**
+   * DLL.
+   */
+  struct AddrEntry *next;
+
+  /**
+   * DLL.
+   */
+  struct AddrEntry *prev;
+
+  /**
+   * Number of bytes that follow.
+   */
+  socklen_t addrlen;
+};
 
 
 /**
@@ -51,6 +76,16 @@ struct GNUNET_NAT_Handle
    */
   struct GNUNET_MessageHeader *reg;
   
+  /**
+   * Head of address DLL.
+   */
+  struct AddrEntry *ae_head;
+
+  /**
+   * Tail of address DLL.
+   */
+  struct AddrEntry *ae_tail;
+
   /**
    * Function to call when our addresses change.
    */
@@ -66,9 +101,162 @@ struct GNUNET_NAT_Handle
    */
   void *callback_cls;
 
+  /**
+   * Task scheduled to reconnect to the service.
+   */
+  struct GNUNET_SCHEDULER_Task *reconnect_task;
+
+  /**
+   * How long to wait until we reconnect.
+   */
+  struct GNUNET_TIME_Relative reconnect_delay;
 };
 
 
+/**
+ * Task to connect to the NAT service.
+ *
+ * @param cls our `struct GNUNET_NAT_Handle *`
+ */
+static void
+do_connect (void *cls);
+
+
+/**
+ * Task to connect to the NAT service.
+ *
+ * @param nh handle to reconnect
+ */
+static void
+reconnect (struct GNUNET_NAT_Handle *nh)
+{
+  if (NULL != nh->mq)
+  {
+    GNUNET_MQ_destroy (nh->mq);
+    nh->mq = NULL;
+  }
+  nh->reconnect_delay
+    = GNUNET_TIME_STD_BACKOFF (nh->reconnect_delay);
+  nh->reconnect_task
+    = GNUNET_SCHEDULER_add_delayed (nh->reconnect_delay,
+				    &do_connect,
+				    nh);
+}
+
+
+/**
+ * Check connection reversal request.
+ *
+ * @param cls our `struct GNUNET_NAT_Handle`
+ * @param crm the message
+ * @return #GNUNET_OK if @a crm is well-formed
+ */
+static int
+check_connection_reversal_request (void *cls,
+				   const struct GNUNET_NAT_ConnectionReversalRequestedMessage *crm)
+{
+  GNUNET_break (0);
+  return GNUNET_SYSERR;
+}
+
+  
+/**
+ * Handle connection reversal request.
+ *
+ * @param cls our `struct GNUNET_NAT_Handle`
+ * @param crm the message
+ */
+static void
+handle_connection_reversal_request (void *cls,
+				    const struct GNUNET_NAT_ConnectionReversalRequestedMessage *crm)
+{
+  // FIXME: parse
+  // FIXME: call callback!
+  GNUNET_break (0);
+}
+
+
+/**
+ * Check address change notification.
+ *
+ * @param cls our `struct GNUNET_NAT_Handle`
+ * @param acn the message
+ * @return #GNUNET_OK if @a crm is well-formed
+ */
+static int
+check_address_change_notification (void *cls,
+				   const struct GNUNET_NAT_AddressChangeNotificationMessage *acn)
+{
+  GNUNET_break (0);
+  return GNUNET_SYSERR;
+}
+
+  
+/**
+ * Handle connection reversal request.
+ *
+ * @param cls our `struct GNUNET_NAT_Handle`
+ * @param acn the message
+ */
+static void
+handle_address_change_notification (void *cls,
+				    const struct GNUNET_NAT_AddressChangeNotificationMessage *acn)
+{
+  // FIXME: parse
+  // FIXME: update ae-DLL
+  // FIXME: call callback!
+  GNUNET_break (0);
+}
+
+
+/**
+ * Handle queue errors by reconnecting to NAT.
+ *
+ * @param cls the `struct GNUNET_NAT_Handle *`
+ * @param error details about the error
+ */
+static void
+mq_error_handler (void *cls,
+		  enum GNUNET_MQ_Error error)
+{
+  struct GNUNET_NAT_Handle *nh = cls;
+
+  reconnect (nh);
+}
+
+
+/**
+ * Task to connect to the NAT service.
+ *
+ * @param cls our `struct GNUNET_NAT_Handle *`
+ */
+static void
+do_connect (void *cls)
+{
+  struct GNUNET_NAT_Handle *nh = cls;
+  struct GNUNET_MQ_MessageHandler handlers[] = {
+    GNUNET_MQ_hd_var_size (connection_reversal_request,
+			   GNUNET_MESSAGE_TYPE_NAT_CONNECTION_REVERSAL_REQUESTED,
+			   struct GNUNET_NAT_ConnectionReversalRequestedMessage,
+			   nh),
+    GNUNET_MQ_hd_var_size (address_change_notification,
+			   GNUNET_MESSAGE_TYPE_NAT_ADDRESS_CHANGE,
+			   struct GNUNET_NAT_AddressChangeNotificationMessage,
+			   nh),
+    GNUNET_MQ_handler_end ()
+  };
+
+  nh->reconnect_task = NULL;
+  nh->mq = GNUNET_CLIENT_connecT (nh->cfg,
+				  "nat",
+				  handlers,
+				  &mq_error_handler,
+				  nh);
+  if (NULL == nh->mq)
+    reconnect (nh);
+}
+
+
 /**
  * Attempt to enable port redirection and detect public IP address
  * contacting UPnP or NAT-PMP routers on the local network. Use @a
@@ -101,17 +289,142 @@ GNUNET_NAT_register (const struct GNUNET_CONFIGURATION_Handle *cfg,
                      GNUNET_NAT_ReversalCallback reversal_callback,
                      void *callback_cls)
 {
-  struct GNUNET_NAT_Handle *nh = GNUNET_new (struct GNUNET_NAT_Handle);
-
+  struct GNUNET_NAT_Handle *nh;
+  struct GNUNET_NAT_RegisterMessage *rm;
+  size_t len;
+  char *off;
+  
+  len = 0;
+  for (unsigned int i=0;i<num_addrs;i++)
+    len += addrlens[i];
+  if ( (len > GNUNET_SERVER_MAX_MESSAGE_SIZE - sizeof (*rm)) ||
+       (num_addrs > UINT16_MAX) )
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  rm = GNUNET_malloc (sizeof (*rm) + len);
+  rm->header.size = htons (sizeof (*rm) + len);
+  rm->header.type = htons (GNUNET_MESSAGE_TYPE_NAT_REGISTER);
+  rm->flags = GNUNET_NAT_RF_NONE;
+  if (NULL != address_callback)
+    rm->flags |= GNUNET_NAT_RF_ADDRESSES;
+  if (NULL != reversal_callback)
+    rm->flags |= GNUNET_NAT_RF_REVERSAL;
+  rm->proto = proto;
+  rm->adv_port = htons (adv_port);
+  rm->num_addrs = htons ((uint16_t) num_addrs);
+  off = (char *) &rm[1];
+  for (unsigned int i=0;i<num_addrs;i++)
+  {
+    GNUNET_memcpy (off,
+		   addrs[i],
+		   addrlens[i]);
+    off += addrlens[i];
+  }
+
+  nh = GNUNET_new (struct GNUNET_NAT_Handle);
+  nh->reg = &rm->header;
   nh->cfg = cfg;
   nh->address_callback = address_callback;
   nh->reversal_callback = reversal_callback;
   nh->callback_cls = callback_cls;
+  do_connect (nh);
   GNUNET_break (0);
   return nh;
 }
 
 
+/**
+ * Check if an incoming message is a STUN message.
+ *
+ * @param data the packet
+ * @param len the length of the packet in @a data
+ * @return #GNUNET_YES if @a data is a STUN packet,
+ *         #GNUNET_NO if the packet is invalid (not a stun packet)
+ */
+static int
+test_stun_packet (const void *data,
+		  size_t len)
+{
+  const struct stun_header *hdr;
+  const struct stun_attr *attr;
+  uint32_t advertised_message_size;
+  uint32_t message_magic_cookie;
+
+  /* On entry, 'len' is the length of the UDP payload. After the
+   * initial checks it becomes the size of unprocessed options,
+   * while 'data' is advanced accordingly.
+   */
+  if (len < sizeof(struct stun_header))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+		"STUN packet too short (only %d, wanting at least %d)\n",
+		(int) len,
+		(int) sizeof (struct stun_header));
+    return GNUNET_NO;
+  }
+  hdr = (const struct stun_header *) data;
+  /* Skip header as it is already in hdr */
+  len -= sizeof (struct stun_header);
+  data += sizeof (struct stun_header);
+
+  /* len as advertised in the message */
+  advertised_message_size = ntohs (hdr->msglen);
+
+  message_magic_cookie = ntohl (hdr->magic);
+  /* Compare if the cookie match */
+  if (STUN_MAGIC_COOKIE != message_magic_cookie)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+		"Invalid magic cookie for STUN\n");
+    return GNUNET_NO;
+  }
+
+  if (advertised_message_size > len)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+		"Scrambled STUN packet length (got %d, expecting %d)\n",
+		advertised_message_size,
+		(int)len);
+    return GNUNET_NO;
+  }
+  len = advertised_message_size;
+  while (len > 0)
+  {
+    if (len < sizeof (struct stun_attr))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+		  "Attribute too short in STUN packet (got %d, expecting %d)\n",
+		  (int) len,
+		  (int) sizeof(struct stun_attr));
+      return GNUNET_NO;
+    }
+    attr = (const struct stun_attr *) data;
+
+    /* compute total attribute length */
+    advertised_message_size = ntohs (attr->len) + sizeof(struct stun_attr);
+
+    /* Check if we still have space in our buffer */
+    if (advertised_message_size > len)
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+		  "Inconsistent Attribute (length %d exceeds remaining msg len %d)\n",
+		  advertised_message_size,
+		  (int) len);
+      return GNUNET_NO;
+    }
+    data += advertised_message_size;
+    len -= advertised_message_size;
+  }
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+	      "STUN Packet, msg %04x, length: %d\n",
+	      ntohs (hdr->msgtype),
+	      advertised_message_size);
+  return GNUNET_OK;
+}
+
+
 /**
  * Handle an incoming STUN message.  This function is useful as
  * some GNUnet service may be listening on a UDP port and might
@@ -128,6 +441,7 @@ GNUNET_NAT_register (const struct GNUNET_CONFIGURATION_Handle *cfg,
  *
  * @param nh handle to the NAT service
  * @param sender_addr address from which we got @a data
+ * @param sender_addr_len number of bytes in @a sender_addr
  * @param data the packet
  * @param data_size number of bytes in @a data
  * @return #GNUNET_OK on success
@@ -137,11 +451,36 @@ GNUNET_NAT_register (const struct GNUNET_CONFIGURATION_Handle *cfg,
 int
 GNUNET_NAT_stun_handle_packet (struct GNUNET_NAT_Handle *nh,
 			       const struct sockaddr *sender_addr,
+			       size_t sender_addr_len,
 			       const void *data,
                                size_t data_size)
 {
-  GNUNET_break (0);
-  return GNUNET_SYSERR;
+  struct GNUNET_MQ_Envelope *env;
+  struct GNUNET_NAT_HandleStunMessage *hsn;
+  char *buf;
+
+  if (GNUNET_YES !=
+      test_stun_packet (data,
+			data_size))
+    return GNUNET_NO;
+  if (NULL == nh->mq)
+    return GNUNET_SYSERR;
+  env = GNUNET_MQ_msg_extra (hsn,
+			     data_size + sender_addr_len,
+			     GNUNET_MESSAGE_TYPE_NAT_HANDLE_STUN);
+  hsn->sender_addr_size = htons ((uint16_t) sender_addr_len);
+  hsn->payload_size = htons ((uint16_t) data_size);
+  buf = (char *) &hsn[1];
+  GNUNET_memcpy (buf,
+		 sender_addr,
+		 sender_addr_len);
+  buf += sender_addr_len;
+  GNUNET_memcpy (buf,
+		 data,
+		 data_size);
+  GNUNET_MQ_send (nh->mq,
+		  env);
+  return GNUNET_OK;
 }
 
 
@@ -163,8 +502,21 @@ GNUNET_NAT_test_address (struct GNUNET_NAT_Handle *nh,
                          const void *addr,
                          socklen_t addrlen)
 {
-  GNUNET_break (0);
-  return GNUNET_SYSERR;
+  struct AddrEntry *ae;
+
+  if ( (addrlen != sizeof (struct sockaddr_in)) &&
+       (addrlen != sizeof (struct sockaddr_in6)) )
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  for (ae = nh->ae_head; NULL != ae; ae = ae->next)
+    if ( (addrlen == ae->addrlen) &&
+	 (0 == memcmp (addr,
+		       &ae[1],
+		       addrlen)) )
+      return GNUNET_YES;
+  return GNUNET_NO;
 }
 
 
@@ -185,8 +537,28 @@ GNUNET_NAT_request_reversal (struct GNUNET_NAT_Handle *nh,
 			     const struct sockaddr_in *local_sa,
 			     const struct sockaddr_in *remote_sa)
 {
-  GNUNET_break (0);
-  return GNUNET_SYSERR;
+  struct GNUNET_MQ_Envelope *env;
+  struct GNUNET_NAT_RequestConnectionReversalMessage *req;
+  char *buf;
+
+  if (NULL == nh->mq)
+    return GNUNET_SYSERR;
+  env = GNUNET_MQ_msg_extra (req,
+			     2 * sizeof (struct sockaddr_in),
+			     GNUNET_MESSAGE_TYPE_NAT_REQUEST_CONNECTION_REVERSAL);
+  req->local_addr_size = htons (sizeof (struct sockaddr_in));
+  req->remote_addr_size = htons (sizeof (struct sockaddr_in));
+  buf = (char *) &req[1];
+  GNUNET_memcpy (buf,
+		 local_sa,
+		 sizeof (struct sockaddr_in));
+  buf += sizeof (struct sockaddr_in);
+  GNUNET_memcpy (buf,
+		 remote_sa,
+		 sizeof (struct sockaddr_in));
+  GNUNET_MQ_send (nh->mq,
+		  env);
+  return GNUNET_OK;
 }
 
 
@@ -236,6 +608,44 @@ struct GNUNET_NAT_Test
 };
 
 
+/**
+ * Handle result for a NAT test from the service.
+ *
+ * @param cls our `struct GNUNET_NAT_Test *`
+ * @param rm message with the result of the test
+ */
+static void
+handle_test_result (void *cls,
+		    const struct GNUNET_NAT_TestResultMessage *rm)
+{
+  struct GNUNET_NAT_Test *tst = cls;
+  enum GNUNET_NAT_StatusCode sc;
+
+  sc = (enum GNUNET_NAT_StatusCode) ntohl (rm->status_code);
+  tst->cb (tst->cb_cls,
+	   sc);
+  GNUNET_NAT_test_stop (tst);  
+}
+		    
+
+/**
+ * Handle queue errors by reconnecting to NAT.
+ *
+ * @param cls the `struct GNUNET_NAT_Test *`
+ * @param error details about the error
+ */
+static void
+tst_error_handler (void *cls,
+		  enum GNUNET_MQ_Error error)
+{
+  struct GNUNET_NAT_Test *tst = cls;
+
+  tst->cb (tst->cb_cls,
+	   GNUNET_NAT_ERROR_IPC_FAILURE);
+  GNUNET_NAT_test_stop (tst);
+}
+
+
 /**
  * Start testing if NAT traversal works using the given configuration
  * (IPv4-only).  The transport adapters should be down while using
@@ -262,10 +672,38 @@ GNUNET_NAT_test_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
                        void *report_cls)
 {
   struct GNUNET_NAT_Test *tst = GNUNET_new (struct GNUNET_NAT_Test);
+  struct GNUNET_MQ_MessageHandler handlers[] = {
+    GNUNET_MQ_hd_fixed_size (test_result,
+			     GNUNET_MESSAGE_TYPE_NAT_TEST_RESULT,
+			     struct GNUNET_NAT_TestResultMessage,
+			     tst),
+    GNUNET_MQ_handler_end ()
+  };
+  struct GNUNET_MQ_Envelope *env;
+  struct GNUNET_NAT_RequestTestMessage *req;
 
   tst->cb = report;
   tst->cb_cls = report_cls;
-  GNUNET_break (0);
+  tst->mq = GNUNET_CLIENT_connecT (cfg,
+				   "nat",
+				   handlers,
+				   &tst_error_handler,
+				   tst);
+  if (NULL == tst->mq)
+  {
+    GNUNET_break (0);
+    GNUNET_free (tst);
+    return NULL;
+  }
+  env = GNUNET_MQ_msg (req,
+		       GNUNET_MESSAGE_TYPE_NAT_REQUEST_TEST);
+  req->bind_port = htons (bnd_port);
+  req->extern_port = htons (extern_port);
+  req->bind_ip = bind_ip;
+  req->extern_ip = extern_ip;
+  req->proto = proto;
+  GNUNET_MQ_send (tst->mq,
+		  env);
   return tst;
 }
 
@@ -278,7 +716,6 @@ GNUNET_NAT_test_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
 void
 GNUNET_NAT_test_stop (struct GNUNET_NAT_Test *tst)
 {
-  GNUNET_break (0);
   GNUNET_MQ_destroy (tst->mq);
   GNUNET_free (tst);
 }