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/*
* Copyright 2004 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef P2P_BASE_STUN_H_
#define P2P_BASE_STUN_H_
// This file contains classes for dealing with the STUN protocol, as specified
// in RFC 5389, and its descendants.
#include <memory>
#include <string>
#include <vector>
#include "rtc_base/bytebuffer.h"
#include "rtc_base/socketaddress.h"
namespace cricket {
// These are the types of STUN messages defined in RFC 5389.
enum StunMessageType {
STUN_BINDING_REQUEST = 0x0001,
STUN_BINDING_INDICATION = 0x0011,
STUN_BINDING_RESPONSE = 0x0101,
STUN_BINDING_ERROR_RESPONSE = 0x0111,
};
// These are all known STUN attributes, defined in RFC 5389 and elsewhere.
// Next to each is the name of the class (T is StunTAttribute) that implements
// that type.
// RETRANSMIT_COUNT is the number of outstanding pings without a response at
// the time the packet is generated.
enum StunAttributeType {
STUN_ATTR_MAPPED_ADDRESS = 0x0001, // Address
STUN_ATTR_USERNAME = 0x0006, // ByteString
STUN_ATTR_MESSAGE_INTEGRITY = 0x0008, // ByteString, 20 bytes
STUN_ATTR_ERROR_CODE = 0x0009, // ErrorCode
STUN_ATTR_UNKNOWN_ATTRIBUTES = 0x000a, // UInt16List
STUN_ATTR_REALM = 0x0014, // ByteString
STUN_ATTR_NONCE = 0x0015, // ByteString
STUN_ATTR_XOR_MAPPED_ADDRESS = 0x0020, // XorAddress
STUN_ATTR_SOFTWARE = 0x8022, // ByteString
STUN_ATTR_ALTERNATE_SERVER = 0x8023, // Address
STUN_ATTR_FINGERPRINT = 0x8028, // UInt32
STUN_ATTR_ORIGIN = 0x802F, // ByteString
STUN_ATTR_RETRANSMIT_COUNT = 0xFF00 // UInt32
};
// These are the types of the values associated with the attributes above.
// This allows us to perform some basic validation when reading or adding
// attributes. Note that these values are for our own use, and not defined in
// RFC 5389.
enum StunAttributeValueType {
STUN_VALUE_UNKNOWN = 0,
STUN_VALUE_ADDRESS = 1,
STUN_VALUE_XOR_ADDRESS = 2,
STUN_VALUE_UINT32 = 3,
STUN_VALUE_UINT64 = 4,
STUN_VALUE_BYTE_STRING = 5,
STUN_VALUE_ERROR_CODE = 6,
STUN_VALUE_UINT16_LIST = 7
};
// These are the types of STUN addresses defined in RFC 5389.
enum StunAddressFamily {
// NB: UNDEF is not part of the STUN spec.
STUN_ADDRESS_UNDEF = 0,
STUN_ADDRESS_IPV4 = 1,
STUN_ADDRESS_IPV6 = 2
};
// These are the types of STUN error codes defined in RFC 5389.
enum StunErrorCode {
STUN_ERROR_TRY_ALTERNATE = 300,
STUN_ERROR_BAD_REQUEST = 400,
STUN_ERROR_UNAUTHORIZED = 401,
STUN_ERROR_UNKNOWN_ATTRIBUTE = 420,
STUN_ERROR_STALE_CREDENTIALS = 430, // GICE only
STUN_ERROR_STALE_NONCE = 438,
STUN_ERROR_SERVER_ERROR = 500,
STUN_ERROR_GLOBAL_FAILURE = 600
};
// Strings for the error codes above.
extern const char STUN_ERROR_REASON_TRY_ALTERNATE_SERVER[];
extern const char STUN_ERROR_REASON_BAD_REQUEST[];
extern const char STUN_ERROR_REASON_UNAUTHORIZED[];
extern const char STUN_ERROR_REASON_UNKNOWN_ATTRIBUTE[];
extern const char STUN_ERROR_REASON_STALE_CREDENTIALS[];
extern const char STUN_ERROR_REASON_STALE_NONCE[];
extern const char STUN_ERROR_REASON_SERVER_ERROR[];
// The mask used to determine whether a STUN message is a request/response etc.
const uint32_t kStunTypeMask = 0x0110;
// STUN Attribute header length.
const size_t kStunAttributeHeaderSize = 4;
// Following values correspond to RFC5389.
const size_t kStunHeaderSize = 20;
const size_t kStunTransactionIdOffset = 8;
const size_t kStunTransactionIdLength = 12;
const uint32_t kStunMagicCookie = 0x2112A442;
const size_t kStunMagicCookieLength = sizeof(kStunMagicCookie);
// Following value corresponds to an earlier version of STUN from
// RFC3489.
const size_t kStunLegacyTransactionIdLength = 16;
// STUN Message Integrity HMAC length.
const size_t kStunMessageIntegritySize = 20;
class StunAttribute;
class StunAddressAttribute;
class StunXorAddressAttribute;
class StunUInt32Attribute;
class StunUInt64Attribute;
class StunByteStringAttribute;
class StunErrorCodeAttribute;
class StunUInt16ListAttribute;
// Records a complete STUN/TURN message. Each message consists of a type and
// any number of attributes. Each attribute is parsed into an instance of an
// appropriate class (see above). The Get* methods will return instances of
// that attribute class.
class StunMessage {
public:
StunMessage();
virtual ~StunMessage();
int type() const { return type_; }
size_t length() const { return length_; }
const std::string& transaction_id() const { return transaction_id_; }
// Returns true if the message confirms to RFC3489 rather than
// RFC5389. The main difference between two version of the STUN
// protocol is the presence of the magic cookie and different length
// of transaction ID. For outgoing packets version of the protocol
// is determined by the lengths of the transaction ID.
bool IsLegacy() const;
void SetType(int type) { type_ = static_cast<uint16_t>(type); }
bool SetTransactionID(const std::string& str);
// Gets the desired attribute value, or NULL if no such attribute type exists.
const StunAddressAttribute* GetAddress(int type) const;
const StunUInt32Attribute* GetUInt32(int type) const;
const StunUInt64Attribute* GetUInt64(int type) const;
const StunByteStringAttribute* GetByteString(int type) const;
// Gets these specific attribute values.
const StunErrorCodeAttribute* GetErrorCode() const;
// Returns the code inside the error code attribute, if present, and
// STUN_ERROR_GLOBAL_FAILURE otherwise.
int GetErrorCodeValue() const;
const StunUInt16ListAttribute* GetUnknownAttributes() const;
// Takes ownership of the specified attribute and adds it to the message.
void AddAttribute(std::unique_ptr<StunAttribute> attr);
// Remove the last occurrence of an attribute.
std::unique_ptr<StunAttribute> RemoveAttribute(int type);
// Validates that a raw STUN message has a correct MESSAGE-INTEGRITY value.
// This can't currently be done on a StunMessage, since it is affected by
// padding data (which we discard when reading a StunMessage).
static bool ValidateMessageIntegrity(const char* data,
size_t size,
const std::string& password);
// Adds a MESSAGE-INTEGRITY attribute that is valid for the current message.
bool AddMessageIntegrity(const std::string& password);
bool AddMessageIntegrity(const char* key, size_t keylen);
// Verifies that a given buffer is STUN by checking for a correct FINGERPRINT.
static bool ValidateFingerprint(const char* data, size_t size);
// Adds a FINGERPRINT attribute that is valid for the current message.
bool AddFingerprint();
// Parses the STUN packet in the given buffer and records it here. The
// return value indicates whether this was successful.
bool Read(rtc::ByteBufferReader* buf);
// Writes this object into a STUN packet. The return value indicates whether
// this was successful.
bool Write(rtc::ByteBufferWriter* buf) const;
// Creates an empty message. Overridable by derived classes.
virtual StunMessage* CreateNew() const;
// Modify the stun magic cookie used for this STUN message.
// This is used for testing.
void SetStunMagicCookie(uint32_t val);
protected:
// Verifies that the given attribute is allowed for this message.
virtual StunAttributeValueType GetAttributeValueType(int type) const;
private:
StunAttribute* CreateAttribute(int type, size_t length) /* const*/;
const StunAttribute* GetAttribute(int type) const;
static bool IsValidTransactionId(const std::string& transaction_id);
uint16_t type_;
uint16_t length_;
std::string transaction_id_;
std::vector<std::unique_ptr<StunAttribute>> attrs_;
uint32_t stun_magic_cookie_;
};
// Base class for all STUN/TURN attributes.
class StunAttribute {
public:
virtual ~StunAttribute() {}
int type() const { return type_; }
size_t length() const { return length_; }
// Return the type of this attribute.
virtual StunAttributeValueType value_type() const = 0;
// Only XorAddressAttribute needs this so far.
virtual void SetOwner(StunMessage* owner) {}
// Reads the body (not the type or length) for this type of attribute from
// the given buffer. Return value is true if successful.
virtual bool Read(rtc::ByteBufferReader* buf) = 0;
// Writes the body (not the type or length) to the given buffer. Return
// value is true if successful.
virtual bool Write(rtc::ByteBufferWriter* buf) const = 0;
// Creates an attribute object with the given type and smallest length.
static StunAttribute* Create(StunAttributeValueType value_type,
uint16_t type,
uint16_t length,
StunMessage* owner);
// TODO(?): Allow these create functions to take parameters, to reduce
// the amount of work callers need to do to initialize attributes.
static std::unique_ptr<StunAddressAttribute> CreateAddress(uint16_t type);
static std::unique_ptr<StunXorAddressAttribute> CreateXorAddress(
uint16_t type);
static std::unique_ptr<StunUInt32Attribute> CreateUInt32(uint16_t type);
static std::unique_ptr<StunUInt64Attribute> CreateUInt64(uint16_t type);
static std::unique_ptr<StunByteStringAttribute> CreateByteString(
uint16_t type);
static std::unique_ptr<StunErrorCodeAttribute> CreateErrorCode();
static std::unique_ptr<StunUInt16ListAttribute> CreateUnknownAttributes();
protected:
StunAttribute(uint16_t type, uint16_t length);
void SetLength(uint16_t length) { length_ = length; }
void WritePadding(rtc::ByteBufferWriter* buf) const;
void ConsumePadding(rtc::ByteBufferReader* buf) const;
private:
uint16_t type_;
uint16_t length_;
};
// Implements STUN attributes that record an Internet address.
class StunAddressAttribute : public StunAttribute {
public:
static const uint16_t SIZE_UNDEF = 0;
static const uint16_t SIZE_IP4 = 8;
static const uint16_t SIZE_IP6 = 20;
StunAddressAttribute(uint16_t type, const rtc::SocketAddress& addr);
StunAddressAttribute(uint16_t type, uint16_t length);
StunAttributeValueType value_type() const override;
StunAddressFamily family() const {
switch (address_.ipaddr().family()) {
case AF_INET:
return STUN_ADDRESS_IPV4;
case AF_INET6:
return STUN_ADDRESS_IPV6;
}
return STUN_ADDRESS_UNDEF;
}
const rtc::SocketAddress& GetAddress() const { return address_; }
const rtc::IPAddress& ipaddr() const { return address_.ipaddr(); }
uint16_t port() const { return address_.port(); }
void SetAddress(const rtc::SocketAddress& addr) {
address_ = addr;
EnsureAddressLength();
}
void SetIP(const rtc::IPAddress& ip) {
address_.SetIP(ip);
EnsureAddressLength();
}
void SetPort(uint16_t port) { address_.SetPort(port); }
bool Read(rtc::ByteBufferReader* buf) override;
bool Write(rtc::ByteBufferWriter* buf) const override;
private:
void EnsureAddressLength() {
switch (family()) {
case STUN_ADDRESS_IPV4: {
SetLength(SIZE_IP4);
break;
}
case STUN_ADDRESS_IPV6: {
SetLength(SIZE_IP6);
break;
}
default: {
SetLength(SIZE_UNDEF);
break;
}
}
}
rtc::SocketAddress address_;
};
// Implements STUN attributes that record an Internet address. When encoded
// in a STUN message, the address contained in this attribute is XORed with the
// transaction ID of the message.
class StunXorAddressAttribute : public StunAddressAttribute {
public:
StunXorAddressAttribute(uint16_t type, const rtc::SocketAddress& addr);
StunXorAddressAttribute(uint16_t type, uint16_t length, StunMessage* owner);
StunAttributeValueType value_type() const override;
void SetOwner(StunMessage* owner) override;
bool Read(rtc::ByteBufferReader* buf) override;
bool Write(rtc::ByteBufferWriter* buf) const override;
private:
rtc::IPAddress GetXoredIP() const;
StunMessage* owner_;
};
// Implements STUN attributes that record a 32-bit integer.
class StunUInt32Attribute : public StunAttribute {
public:
static const uint16_t SIZE = 4;
StunUInt32Attribute(uint16_t type, uint32_t value);
explicit StunUInt32Attribute(uint16_t type);
StunAttributeValueType value_type() const override;
uint32_t value() const { return bits_; }
void SetValue(uint32_t bits) { bits_ = bits; }
bool GetBit(size_t index) const;
void SetBit(size_t index, bool value);
bool Read(rtc::ByteBufferReader* buf) override;
bool Write(rtc::ByteBufferWriter* buf) const override;
private:
uint32_t bits_;
};
class StunUInt64Attribute : public StunAttribute {
public:
static const uint16_t SIZE = 8;
StunUInt64Attribute(uint16_t type, uint64_t value);
explicit StunUInt64Attribute(uint16_t type);
StunAttributeValueType value_type() const override;
uint64_t value() const { return bits_; }
void SetValue(uint64_t bits) { bits_ = bits; }
bool Read(rtc::ByteBufferReader* buf) override;
bool Write(rtc::ByteBufferWriter* buf) const override;
private:
uint64_t bits_;
};
// Implements STUN attributes that record an arbitrary byte string.
class StunByteStringAttribute : public StunAttribute {
public:
explicit StunByteStringAttribute(uint16_t type);
StunByteStringAttribute(uint16_t type, const std::string& str);
StunByteStringAttribute(uint16_t type, const void* bytes, size_t length);
StunByteStringAttribute(uint16_t type, uint16_t length);
~StunByteStringAttribute() override;
StunAttributeValueType value_type() const override;
const char* bytes() const { return bytes_; }
std::string GetString() const { return std::string(bytes_, length()); }
void CopyBytes(const char* bytes); // uses strlen
void CopyBytes(const void* bytes, size_t length);
uint8_t GetByte(size_t index) const;
void SetByte(size_t index, uint8_t value);
bool Read(rtc::ByteBufferReader* buf) override;
bool Write(rtc::ByteBufferWriter* buf) const override;
private:
void SetBytes(char* bytes, size_t length);
char* bytes_;
};
// Implements STUN attributes that record an error code.
class StunErrorCodeAttribute : public StunAttribute {
public:
static const uint16_t MIN_SIZE;
StunErrorCodeAttribute(uint16_t type, int code, const std::string& reason);
StunErrorCodeAttribute(uint16_t type, uint16_t length);
~StunErrorCodeAttribute() override;
StunAttributeValueType value_type() const override;
// The combined error and class, e.g. 0x400.
int code() const;
void SetCode(int code);
// The individual error components.
int eclass() const { return class_; }
int number() const { return number_; }
const std::string& reason() const { return reason_; }
void SetClass(uint8_t eclass) { class_ = eclass; }
void SetNumber(uint8_t number) { number_ = number; }
void SetReason(const std::string& reason);
bool Read(rtc::ByteBufferReader* buf) override;
bool Write(rtc::ByteBufferWriter* buf) const override;
private:
uint8_t class_;
uint8_t number_;
std::string reason_;
};
// Implements STUN attributes that record a list of attribute names.
class StunUInt16ListAttribute : public StunAttribute {
public:
StunUInt16ListAttribute(uint16_t type, uint16_t length);
~StunUInt16ListAttribute() override;
StunAttributeValueType value_type() const override;
size_t Size() const;
uint16_t GetType(int index) const;
void SetType(int index, uint16_t value);
void AddType(uint16_t value);
bool Read(rtc::ByteBufferReader* buf) override;
bool Write(rtc::ByteBufferWriter* buf) const override;
private:
std::vector<uint16_t>* attr_types_;
};
// Returns the (successful) response type for the given request type.
// Returns -1 if |request_type| is not a valid request type.
int GetStunSuccessResponseType(int request_type);
// Returns the error response type for the given request type.
// Returns -1 if |request_type| is not a valid request type.
int GetStunErrorResponseType(int request_type);
// Returns whether a given message is a request type.
bool IsStunRequestType(int msg_type);
// Returns whether a given message is an indication type.
bool IsStunIndicationType(int msg_type);
// Returns whether a given response is a success type.
bool IsStunSuccessResponseType(int msg_type);
// Returns whether a given response is an error type.
bool IsStunErrorResponseType(int msg_type);
// Computes the STUN long-term credential hash.
bool ComputeStunCredentialHash(const std::string& username,
const std::string& realm,
const std::string& password,
std::string* hash);
// Make a copy af |attribute| and return a new StunAttribute.
// This is useful if you don't care about what kind of attribute you
// are handling.
//
// The implementation copies by calling Write() followed by Read().
//
// If |tmp_buffer| is supplied this buffer will be used, otherwise
// a buffer will created in the method.
std::unique_ptr<StunAttribute> CopyStunAttribute(
const StunAttribute& attribute,
rtc::ByteBufferWriter* tmp_buffer_ptr = 0);
// TODO(?): Move the TURN/ICE stuff below out to separate files.
extern const char TURN_MAGIC_COOKIE_VALUE[4];
// "GTURN" STUN methods.
// TODO(?): Rename these methods to GTURN_ to make it clear they aren't
// part of standard STUN/TURN.
enum RelayMessageType {
// For now, using the same defs from TurnMessageType below.
// STUN_ALLOCATE_REQUEST = 0x0003,
// STUN_ALLOCATE_RESPONSE = 0x0103,
// STUN_ALLOCATE_ERROR_RESPONSE = 0x0113,
STUN_SEND_REQUEST = 0x0004,
STUN_SEND_RESPONSE = 0x0104,
STUN_SEND_ERROR_RESPONSE = 0x0114,
STUN_DATA_INDICATION = 0x0115,
};
// "GTURN"-specific STUN attributes.
// TODO(?): Rename these attributes to GTURN_ to avoid conflicts.
enum RelayAttributeType {
STUN_ATTR_LIFETIME = 0x000d, // UInt32
STUN_ATTR_MAGIC_COOKIE = 0x000f, // ByteString, 4 bytes
STUN_ATTR_BANDWIDTH = 0x0010, // UInt32
STUN_ATTR_DESTINATION_ADDRESS = 0x0011, // Address
STUN_ATTR_SOURCE_ADDRESS2 = 0x0012, // Address
STUN_ATTR_DATA = 0x0013, // ByteString
STUN_ATTR_OPTIONS = 0x8001, // UInt32
};
// A "GTURN" STUN message.
class RelayMessage : public StunMessage {
protected:
StunAttributeValueType GetAttributeValueType(int type) const override;
StunMessage* CreateNew() const override;
};
// Defined in TURN RFC 5766.
enum TurnMessageType {
STUN_ALLOCATE_REQUEST = 0x0003,
STUN_ALLOCATE_RESPONSE = 0x0103,
STUN_ALLOCATE_ERROR_RESPONSE = 0x0113,
TURN_REFRESH_REQUEST = 0x0004,
TURN_REFRESH_RESPONSE = 0x0104,
TURN_REFRESH_ERROR_RESPONSE = 0x0114,
TURN_SEND_INDICATION = 0x0016,
TURN_DATA_INDICATION = 0x0017,
TURN_CREATE_PERMISSION_REQUEST = 0x0008,
TURN_CREATE_PERMISSION_RESPONSE = 0x0108,
TURN_CREATE_PERMISSION_ERROR_RESPONSE = 0x0118,
TURN_CHANNEL_BIND_REQUEST = 0x0009,
TURN_CHANNEL_BIND_RESPONSE = 0x0109,
TURN_CHANNEL_BIND_ERROR_RESPONSE = 0x0119,
};
enum TurnAttributeType {
STUN_ATTR_CHANNEL_NUMBER = 0x000C, // UInt32
STUN_ATTR_TURN_LIFETIME = 0x000d, // UInt32
STUN_ATTR_XOR_PEER_ADDRESS = 0x0012, // XorAddress
// TODO(mallinath) - Uncomment after RelayAttributes are renamed.
// STUN_ATTR_DATA = 0x0013, // ByteString
STUN_ATTR_XOR_RELAYED_ADDRESS = 0x0016, // XorAddress
STUN_ATTR_EVEN_PORT = 0x0018, // ByteString, 1 byte.
STUN_ATTR_REQUESTED_TRANSPORT = 0x0019, // UInt32
STUN_ATTR_DONT_FRAGMENT = 0x001A, // No content, Length = 0
STUN_ATTR_RESERVATION_TOKEN = 0x0022, // ByteString, 8 bytes.
// TODO(mallinath) - Rename STUN_ATTR_TURN_LIFETIME to STUN_ATTR_LIFETIME and
// STUN_ATTR_TURN_DATA to STUN_ATTR_DATA. Also rename RelayMessage attributes
// by appending G to attribute name.
};
// RFC 5766-defined errors.
enum TurnErrorType {
STUN_ERROR_FORBIDDEN = 403,
STUN_ERROR_ALLOCATION_MISMATCH = 437,
STUN_ERROR_WRONG_CREDENTIALS = 441,
STUN_ERROR_UNSUPPORTED_PROTOCOL = 442
};
extern const char STUN_ERROR_REASON_FORBIDDEN[];
extern const char STUN_ERROR_REASON_ALLOCATION_MISMATCH[];
extern const char STUN_ERROR_REASON_WRONG_CREDENTIALS[];
extern const char STUN_ERROR_REASON_UNSUPPORTED_PROTOCOL[];
class TurnMessage : public StunMessage {
protected:
StunAttributeValueType GetAttributeValueType(int type) const override;
StunMessage* CreateNew() const override;
};
// RFC 5245 ICE STUN attributes.
enum IceAttributeType {
STUN_ATTR_PRIORITY = 0x0024, // UInt32
STUN_ATTR_USE_CANDIDATE = 0x0025, // No content, Length = 0
STUN_ATTR_ICE_CONTROLLED = 0x8029, // UInt64
STUN_ATTR_ICE_CONTROLLING = 0x802A, // UInt64
STUN_ATTR_NOMINATION = 0xC001, // UInt32
// UInt32. The higher 16 bits are the network ID. The lower 16 bits are the
// network cost.
STUN_ATTR_NETWORK_INFO = 0xC057
};
// RFC 5245-defined errors.
enum IceErrorCode {
STUN_ERROR_ROLE_CONFLICT = 487,
};
extern const char STUN_ERROR_REASON_ROLE_CONFLICT[];
// A RFC 5245 ICE STUN message.
class IceMessage : public StunMessage {
protected:
StunAttributeValueType GetAttributeValueType(int type) const override;
StunMessage* CreateNew() const override;
};
} // namespace cricket
#endif // P2P_BASE_STUN_H_