towards moving STUN logic into new NAT service

1 files changed, 157 insertions, 13 deletions

diff --git a/src/nat/nat_stun.h b/src/nat/nat_stun.h
index f8d99b164..4c6c178fb 100644
--- a/src/nat/nat_stun.h
+++ b/src/nat/nat_stun.h
@@ -17,15 +17,14 @@
      Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
      Boston, MA 02110-1301, USA.
 */
-
 /**
- * Testcase for STUN server resolution
+ * Message types for STUN server resolution
  *
  * @file nat/nat_stun.h
  * @brief Testcase for STUN library
  * @author Bruno Souza Cabral
  * @autor Mark Spencer (Original code borrowed from Asterisk)
- *
+ * @author Christian Grothoff
  */
 
 
@@ -34,7 +33,10 @@
 
 #define STUN_MAGIC_COOKIE       0x2112A442
 
-typedef struct { uint32_t id[3]; } GNUNET_PACKED stun_trans_id;
+typedef struct {
+  uint32_t id[3];
+} GNUNET_PACKED stun_trans_id;
+
 
 struct stun_header
 {
@@ -44,32 +46,47 @@ struct stun_header
   stun_trans_id id;
 } GNUNET_PACKED;
 
+
 struct stun_attr
 {
   uint16_t attr;
   uint16_t len;
 } GNUNET_PACKED;
 
-/*
+
+/**
  * The format normally used for addresses carried by STUN messages.
  */
 struct stun_addr
 {
   uint8_t  unused;
+
+  /**
+   * Address family, we expect AF_INET.
+   */
   uint8_t  family;
+
+  /**
+   * Port number.
+   */
   uint16_t port;
+  
+  /**
+   * IPv4 address. Should this be "struct in_addr"?
+   */
   uint32_t   addr;
 } GNUNET_PACKED;
 
 
-
-/* STUN message classes */
+/**
+ * STUN message classes 
+ */
 enum StunClasses {
-    INVALID_CLASS = 0,
-    STUN_REQUEST = 0x0000,
-    STUN_INDICATION = 0x0001,
-    STUN_RESPONSE = 0x0002,
-    STUN_ERROR_RESPONSE = 0x0003
+  INVALID_CLASS = 0,
+  STUN_REQUEST = 0x0000,
+  STUN_INDICATION = 0x0001,
+  STUN_RESPONSE = 0x0002,
+  STUN_ERROR_RESPONSE = 0x0003
 };
 
 enum StunMethods {
@@ -84,7 +101,9 @@ enum StunMethods {
   STUN_CHANNEL_BIND = 0x0009
 };
 
-/* Basic attribute types in stun messages.
+
+/**
+ * Basic attribute types in stun messages.
  * Messages can also contain custom attributes (codes above 0x7fff)
  */
 enum StunAttributes {
@@ -108,3 +127,128 @@ enum StunAttributes {
   STUN_ALTERNATE_SERVER = 0x8023,
   STUN_FINGERPRINT = 0x8028
 };
+
+
+/**
+ * Convert a message to a StunClass
+ *
+ * @param msg the received message
+ * @return the converted StunClass
+ */
+static int
+decode_class(int msg)
+{
+  /* Sorry for the magic, but this maps the class according to rfc5245 */
+  return ((msg & 0x0010) >> 4) | ((msg & 0x0100) >> 7);
+}
+
+/**
+ * Convert a message to a StunMethod
+ *
+ * @param msg the received message
+ * @return the converted StunMethod
+ */
+static int
+decode_method(int msg)
+{
+  return (msg & 0x000f) | ((msg & 0x00e0) >> 1) | ((msg & 0x3e00) >> 2);
+}
+
+
+/**
+ * Print a class and method from a STUN message
+ *
+ * @param msg
+ * @return string with the message class and method
+ */
+static const char *
+stun_msg2str (int msg)
+{
+  static const struct {
+    enum StunClasses value;
+    const char *name;
+  } classes[] = {
+    { STUN_REQUEST, "Request" },
+    { STUN_INDICATION, "Indication" },
+    { STUN_RESPONSE, "Response" },
+    { STUN_ERROR_RESPONSE, "Error Response" },
+    { 0, NULL }
+  };
+  static const struct {
+    enum StunMethods value;
+    const char *name;
+  } methods[] = {
+    { STUN_BINDING, "Binding" },
+    { 0, NULL }
+  };
+  static char result[64];
+  const char *msg_class = NULL;
+  const char *method = NULL;
+  int value;
+
+  value = decode_class (msg);
+  for (unsigned int i = 0; classes[i].name; i++)
+    if (classes[i].value == value)
+    {
+      msg_class = classes[i].name;
+      break;
+    }
+  value = decode_method (msg);
+  for (unsigned int i = 0; methods[i].name; i++)
+    if (methods[i].value == value)
+    {
+      method = methods[i].name;
+      break;
+    }
+  GNUNET_snprintf (result,
+                   sizeof(result),
+                   "%s %s",
+                   method ? : "Unknown Method",
+                   msg_class ? : "Unknown Class Message");
+  return result;
+}
+
+
+/**
+ * Print attribute name
+ *
+ * @param msg with a attribute type
+ * @return string with the attribute name
+ */
+static const char *
+stun_attr2str (enum StunAttributes msg)
+{
+  static const struct {
+    enum StunAttributes value;
+    const char *name;
+  } attrs[] = {
+    { STUN_MAPPED_ADDRESS, "Mapped Address" },
+    { STUN_RESPONSE_ADDRESS, "Response Address" },
+    { STUN_CHANGE_ADDRESS, "Change Address" },
+    { STUN_SOURCE_ADDRESS, "Source Address" },
+    { STUN_CHANGED_ADDRESS, "Changed Address" },
+    { STUN_USERNAME, "Username" },
+    { STUN_PASSWORD, "Password" },
+    { STUN_MESSAGE_INTEGRITY, "Message Integrity" },
+    { STUN_ERROR_CODE, "Error Code" },
+    { STUN_UNKNOWN_ATTRIBUTES, "Unknown Attributes" },
+    { STUN_REFLECTED_FROM, "Reflected From" },
+    { STUN_REALM, "Realm" },
+    { STUN_NONCE, "Nonce" },
+    { STUN_XOR_MAPPED_ADDRESS, "XOR Mapped Address" },
+    { STUN_MS_VERSION, "MS Version" },
+    { STUN_MS_XOR_MAPPED_ADDRESS, "MS XOR Mapped Address" },
+    { STUN_SOFTWARE, "Software" },
+    { STUN_ALTERNATE_SERVER, "Alternate Server" },
+    { STUN_FINGERPRINT, "Fingerprint" },
+    { 0, NULL }
+  };
+
+  for (unsigned int i = 0; attrs[i].name; i++)
+    if (attrs[i].value == msg)
+      return attrs[i].name;
+  return "Unknown Attribute";
+}
+
+
+/* end of nat_stun.h */