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      1 /*
      2  * libjingle
      3  * Copyright 2004--2005, Google Inc.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions are met:
      7  *
      8  *  1. Redistributions of source code must retain the above copyright notice,
      9  *     this list of conditions and the following disclaimer.
     10  *  2. Redistributions in binary form must reproduce the above copyright notice,
     11  *     this list of conditions and the following disclaimer in the documentation
     12  *     and/or other materials provided with the distribution.
     13  *  3. The name of the author may not be used to endorse or promote products
     14  *     derived from this software without specific prior written permission.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
     19  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     20  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #ifndef __STUN_H__
     29 #define __STUN_H__
     30 
     31 // This file contains classes for dealing with the STUN and TURN protocols.
     32 // Both protocols use the same wire format.
     33 
     34 #include <string>
     35 #include <vector>
     36 
     37 #include "talk/base/basictypes.h"
     38 #include "talk/base/bytebuffer.h"
     39 
     40 namespace cricket {
     41 
     42 // These are the types of STUN & TURN messages as of last check.
     43 enum StunMessageType {
     44   STUN_BINDING_REQUEST              = 0x0001,
     45   STUN_BINDING_RESPONSE             = 0x0101,
     46   STUN_BINDING_ERROR_RESPONSE       = 0x0111,
     47   STUN_SHARED_SECRET_REQUEST        = 0x0002,
     48   STUN_SHARED_SECRET_RESPONSE       = 0x0102,
     49   STUN_SHARED_SECRET_ERROR_RESPONSE = 0x0112,
     50   STUN_ALLOCATE_REQUEST             = 0x0003,
     51   STUN_ALLOCATE_RESPONSE            = 0x0103,
     52   STUN_ALLOCATE_ERROR_RESPONSE      = 0x0113,
     53   STUN_SEND_REQUEST                 = 0x0004,
     54   STUN_SEND_RESPONSE                = 0x0104,
     55   STUN_SEND_ERROR_RESPONSE          = 0x0114,
     56   STUN_DATA_INDICATION              = 0x0115
     57 };
     58 
     59 // These are the types of attributes defined in STUN & TURN.  Next to each is
     60 // the name of the class (T is StunTAttribute) that implements that type.
     61 enum StunAttributeType {
     62   STUN_ATTR_MAPPED_ADDRESS        = 0x0001, // Address
     63   STUN_ATTR_RESPONSE_ADDRESS      = 0x0002, // Address
     64   STUN_ATTR_CHANGE_REQUEST        = 0x0003, // UInt32
     65   STUN_ATTR_SOURCE_ADDRESS        = 0x0004, // Address
     66   STUN_ATTR_CHANGED_ADDRESS       = 0x0005, // Address
     67   STUN_ATTR_USERNAME              = 0x0006, // ByteString, multiple of 4 bytes
     68   STUN_ATTR_PASSWORD              = 0x0007, // ByteString, multiple of 4 bytes
     69   STUN_ATTR_MESSAGE_INTEGRITY     = 0x0008, // ByteString, 20 bytes
     70   STUN_ATTR_ERROR_CODE            = 0x0009, // ErrorCode
     71   STUN_ATTR_UNKNOWN_ATTRIBUTES    = 0x000a, // UInt16List
     72   STUN_ATTR_REFLECTED_FROM        = 0x000b, // Address
     73   STUN_ATTR_TRANSPORT_PREFERENCES = 0x000c, // TransportPrefs
     74   STUN_ATTR_LIFETIME              = 0x000d, // UInt32
     75   STUN_ATTR_ALTERNATE_SERVER      = 0x000e, // Address
     76   STUN_ATTR_MAGIC_COOKIE          = 0x000f, // ByteString, 4 bytes
     77   STUN_ATTR_BANDWIDTH             = 0x0010, // UInt32
     78   STUN_ATTR_DESTINATION_ADDRESS   = 0x0011, // Address
     79   STUN_ATTR_SOURCE_ADDRESS2       = 0x0012, // Address
     80   STUN_ATTR_DATA                  = 0x0013, // ByteString
     81   STUN_ATTR_OPTIONS               = 0x8001  // UInt32
     82 };
     83 
     84 enum StunErrorCodes {
     85   STUN_ERROR_BAD_REQUEST          = 400,
     86   STUN_ERROR_UNAUTHORIZED         = 401,
     87   STUN_ERROR_UNKNOWN_ATTRIBUTE    = 420,
     88   STUN_ERROR_STALE_CREDENTIALS    = 430,
     89   STUN_ERROR_INTEGRITY_CHECK_FAILURE = 431,
     90   STUN_ERROR_MISSING_USERNAME     = 432,
     91   STUN_ERROR_USE_TLS              = 433,
     92   STUN_ERROR_SERVER_ERROR         = 500,
     93   STUN_ERROR_GLOBAL_FAILURE       = 600
     94 };
     95 
     96 extern const std::string STUN_ERROR_REASON_BAD_REQUEST;
     97 extern const std::string STUN_ERROR_REASON_UNAUTHORIZED;
     98 extern const std::string STUN_ERROR_REASON_UNKNOWN_ATTRIBUTE;
     99 extern const std::string STUN_ERROR_REASON_STALE_CREDENTIALS;
    100 extern const std::string STUN_ERROR_REASON_INTEGRITY_CHECK_FAILURE;
    101 extern const std::string STUN_ERROR_REASON_MISSING_USERNAME;
    102 extern const std::string STUN_ERROR_REASON_USE_TLS;
    103 extern const std::string STUN_ERROR_REASON_SERVER_ERROR;
    104 extern const std::string STUN_ERROR_REASON_GLOBAL_FAILURE;
    105 
    106 class StunAttribute;
    107 class StunAddressAttribute;
    108 class StunUInt32Attribute;
    109 class StunByteStringAttribute;
    110 class StunErrorCodeAttribute;
    111 class StunUInt16ListAttribute;
    112 class StunTransportPrefsAttribute;
    113 
    114 // Records a complete STUN/TURN message.  Each message consists of a type and
    115 // any number of attributes.  Each attribute is parsed into an instance of an
    116 // appropriate class (see above).  The Get* methods will return instances of
    117 // that attribute class.
    118 class StunMessage {
    119 public:
    120   StunMessage();
    121   ~StunMessage();
    122 
    123   StunMessageType type() const { return static_cast<StunMessageType>(type_); }
    124   uint16 length() const { return length_; }
    125   const std::string& transaction_id() const { return transaction_id_; }
    126 
    127   void SetType(StunMessageType type) { type_ = type; }
    128   void SetTransactionID(const std::string& str);
    129 
    130   const StunAddressAttribute* GetAddress(StunAttributeType type) const;
    131   const StunUInt32Attribute* GetUInt32(StunAttributeType type) const;
    132   const StunByteStringAttribute* GetByteString(StunAttributeType type) const;
    133   const StunErrorCodeAttribute* GetErrorCode() const;
    134   const StunUInt16ListAttribute* GetUnknownAttributes() const;
    135   const StunTransportPrefsAttribute* GetTransportPrefs() const;
    136 
    137   void AddAttribute(StunAttribute* attr);
    138 
    139   // Parses the STUN/TURN packet in the given buffer and records it here.  The
    140   // return value indicates whether this was successful.
    141   bool Read(talk_base::ByteBuffer* buf);
    142 
    143   // Writes this object into a STUN/TURN packet.  Return value is true if
    144   // successful.
    145   void Write(talk_base::ByteBuffer* buf) const;
    146 
    147 private:
    148   uint16 type_;
    149   uint16 length_;
    150   std::string transaction_id_;
    151   std::vector<StunAttribute*>* attrs_;
    152 
    153   const StunAttribute* GetAttribute(StunAttributeType type) const;
    154 };
    155 
    156 // Base class for all STUN/TURN attributes.
    157 class StunAttribute {
    158 public:
    159   virtual ~StunAttribute() {}
    160 
    161   StunAttributeType type() const {
    162     return static_cast<StunAttributeType>(type_);
    163   }
    164   uint16 length() const { return length_; }
    165 
    166   // Reads the body (not the type or length) for this type of attribute from
    167   // the given buffer.  Return value is true if successful.
    168   virtual bool Read(talk_base::ByteBuffer* buf) = 0;
    169 
    170   // Writes the body (not the type or length) to the given buffer.  Return
    171   // value is true if successful.
    172   virtual void Write(talk_base::ByteBuffer* buf) const = 0;
    173 
    174   // Creates an attribute object with the given type and len.
    175   static StunAttribute* Create(uint16 type, uint16 length);
    176 
    177   // Creates an attribute object with the given type and smallest length.
    178   static StunAddressAttribute* CreateAddress(uint16 type);
    179   static StunUInt32Attribute* CreateUInt32(uint16 type);
    180   static StunByteStringAttribute* CreateByteString(uint16 type);
    181   static StunErrorCodeAttribute* CreateErrorCode();
    182   static StunUInt16ListAttribute* CreateUnknownAttributes();
    183   static StunTransportPrefsAttribute* CreateTransportPrefs();
    184 
    185 protected:
    186   StunAttribute(uint16 type, uint16 length);
    187 
    188   void SetLength(uint16 length) { length_ = length; }
    189 
    190 private:
    191   uint16 type_;
    192   uint16 length_;
    193 };
    194 
    195 // Implements STUN/TURN attributes that record an Internet address.
    196 class StunAddressAttribute : public StunAttribute {
    197 public:
    198   StunAddressAttribute(uint16 type);
    199 
    200 #if (_MSC_VER < 1300)
    201   enum { SIZE = 8 };
    202 #else
    203   static const uint16 SIZE = 8;
    204 #endif
    205 
    206   uint8 family() const { return family_; }
    207   uint16 port() const { return port_; }
    208   uint32 ip() const { return ip_; }
    209 
    210   void SetFamily(uint8 family) { family_ = family; }
    211   void SetIP(uint32 ip) { ip_ = ip; }
    212   void SetPort(uint16 port) { port_ = port; }
    213 
    214   bool Read(talk_base::ByteBuffer* buf);
    215   void Write(talk_base::ByteBuffer* buf) const;
    216 
    217 private:
    218   uint8 family_;
    219   uint16 port_;
    220   uint32 ip_;
    221 };
    222 
    223 // Implements STUN/TURN attributs that record a 32-bit integer.
    224 class StunUInt32Attribute : public StunAttribute {
    225 public:
    226   StunUInt32Attribute(uint16 type);
    227 
    228 #if (_MSC_VER < 1300)
    229   enum { SIZE = 4 };
    230 #else
    231   static const uint16 SIZE = 4;
    232 #endif
    233 
    234   uint32 value() const { return bits_; }
    235 
    236   void SetValue(uint32 bits) { bits_ = bits; }
    237 
    238   bool GetBit(int index) const;
    239   void SetBit(int index, bool value);
    240 
    241   bool Read(talk_base::ByteBuffer* buf);
    242   void Write(talk_base::ByteBuffer* buf) const;
    243 
    244 private:
    245   uint32 bits_;
    246 };
    247 
    248 // Implements STUN/TURN attributs that record an arbitrary byte string
    249 class StunByteStringAttribute : public StunAttribute {
    250 public:
    251   StunByteStringAttribute(uint16 type, uint16 length);
    252   ~StunByteStringAttribute();
    253 
    254   const char* bytes() const { return bytes_; }
    255 
    256   void SetBytes(char* bytes, uint16 length);
    257 
    258   void CopyBytes(const char* bytes); // uses strlen
    259   void CopyBytes(const void* bytes, uint16 length);
    260 
    261   uint8 GetByte(int index) const;
    262   void SetByte(int index, uint8 value);
    263 
    264   bool Read(talk_base::ByteBuffer* buf);
    265   void Write(talk_base::ByteBuffer* buf) const;
    266 
    267 private:
    268   char* bytes_;
    269 };
    270 
    271 // Implements STUN/TURN attributs that record an error code.
    272 class StunErrorCodeAttribute : public StunAttribute {
    273 public:
    274   StunErrorCodeAttribute(uint16 type, uint16 length);
    275   ~StunErrorCodeAttribute();
    276 
    277 #if (_MSC_VER < 1300)
    278   enum { MIN_SIZE = 4 };
    279 #else
    280   static const uint16 MIN_SIZE = 4;
    281 #endif
    282 
    283   uint32 error_code() const { return (class_ << 8) | number_; }
    284   uint8 error_class() const { return class_; }
    285   uint8 number() const { return number_; }
    286   const std::string& reason() const { return reason_; }
    287 
    288   void SetErrorCode(uint32 code);
    289   void SetErrorClass(uint8 eclass) { class_ = eclass; }
    290   void SetNumber(uint8 number) { number_ = number; }
    291   void SetReason(const std::string& reason);
    292 
    293   bool Read(talk_base::ByteBuffer* buf);
    294   void Write(talk_base::ByteBuffer* buf) const;
    295 
    296 private:
    297   uint8 class_;
    298   uint8 number_;
    299   std::string reason_;
    300 };
    301 
    302 // Implements STUN/TURN attributs that record a list of attribute names.
    303 class StunUInt16ListAttribute : public StunAttribute {
    304 public:
    305   StunUInt16ListAttribute(uint16 type, uint16 length);
    306   ~StunUInt16ListAttribute();
    307 
    308   size_t Size() const;
    309   uint16 GetType(int index) const;
    310   void SetType(int index, uint16 value);
    311   void AddType(uint16 value);
    312 
    313   bool Read(talk_base::ByteBuffer* buf);
    314   void Write(talk_base::ByteBuffer* buf) const;
    315 
    316 private:
    317   std::vector<uint16>* attr_types_;
    318 };
    319 
    320 // Implements the TURN TRANSPORT-PREFS attribute, which provides information
    321 // about the ports to allocate.
    322 class StunTransportPrefsAttribute : public StunAttribute {
    323 public:
    324   StunTransportPrefsAttribute(uint16 type, uint16 length);
    325   ~StunTransportPrefsAttribute();
    326 
    327 #if (_MSC_VER < 1300)
    328   enum { SIZE1 = 4, SIZE2 = 12 };
    329 #else
    330   static const uint16 SIZE1 = 4;
    331   static const uint16 SIZE2 = 12;
    332 #endif
    333 
    334   bool preallocate() const { return preallocate_; }
    335   uint8 preference_type() const { return prefs_; }
    336   const StunAddressAttribute* address() const { return addr_; }
    337 
    338   void SetPreferenceType(uint8 prefs) { prefs_ = prefs; }
    339 
    340   // Sets the preallocate address to the given value, or if 0 is given, it sets
    341   // to not preallocate.
    342   void SetPreallocateAddress(StunAddressAttribute* addr);
    343 
    344   bool Read(talk_base::ByteBuffer* buf);
    345   void Write(talk_base::ByteBuffer* buf) const;
    346 
    347 private:
    348   bool preallocate_;
    349   uint8 prefs_;
    350   StunAddressAttribute* addr_;
    351 };
    352 
    353 // The special MAGIC-COOKIE attribute is used to distinguish TURN packets from
    354 // other kinds of traffic.
    355 const char STUN_MAGIC_COOKIE_VALUE[] = { 0x72, char(0xc6), 0x4b, char(0xc6) };
    356 
    357 // Returns the (successful) response type for the given request type.
    358 StunMessageType GetStunResponseType(StunMessageType request_type);
    359 
    360 // Returns the error response type for the given request type.
    361 StunMessageType GetStunErrorResponseType(StunMessageType request_type);
    362 
    363 } // namespace cricket
    364 
    365 #endif // __STUN_H__
    366