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methods for I2NP header access

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orignal 2015-01-01 16:51:15 -05:00
parent c5c0d2060c
commit bfc6274cd8
2 changed files with 43 additions and 20 deletions
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35
I2NPProtocol.h
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@ -3,6 +3,7 @@
#include <inttypes.h>
#include <set>
#include <cryptopp/sha.h>
#include <string.h>
#include "I2PEndian.h"
#include "Identity.h"
@ -10,7 +11,14 @@
#include "LeaseSet.h"
namespace i2p
{
{
// I2NP header
const size_t I2NP_HEADER_TYPEID_OFFSET = 0;
const size_t I2NP_HEADER_MSGID_OFFSET = I2NP_HEADER_TYPEID_OFFSET + 1;
const size_t I2NP_HEADER_EXPIRATION_OFFSET = I2NP_HEADER_MSGID_OFFSET + 4;
const size_t I2NP_HEADER_SIZE_OFFSET = I2NP_HEADER_EXPIRATION_OFFSET + 8;
const size_t I2NP_HEADER_CHKS_OFFSET = I2NP_HEADER_SIZE_OFFSET + 2;
#pragma pack (1)
struct I2NPHeader
@ -114,11 +122,32 @@ namespace tunnel
I2NPMessage (): buf (nullptr),len (sizeof (I2NPHeader) + 2),
offset(2), maxLen (0), from (nullptr) {};
// reserve 2 bytes for NTCP header
I2NPHeader * GetHeader () { return (I2NPHeader *)GetBuffer (); };
I2NPHeader * GetHeader () { return (I2NPHeader *)GetBuffer (); }; // depricated
// header accessors
uint8_t * GetHeaderBuffer () { return GetBuffer (); };
const uint8_t * GetHeaderBuffer () const { return GetBuffer (); };
void SetTypeID (uint8_t typeID) { GetHeaderBuffer ()[I2NP_HEADER_TYPEID_OFFSET] = typeID; };
uint8_t GetTypeID () const { return GetHeaderBuffer ()[I2NP_HEADER_TYPEID_OFFSET]; };
void SetMsgID (uint32_t msgID) { htobe32buf (GetHeaderBuffer () + I2NP_HEADER_MSGID_OFFSET, msgID); };
uint32_t GetMsgID () const { return bufbe32toh (GetHeaderBuffer () + I2NP_HEADER_MSGID_OFFSET); };
void SetExpiration (uint64_t expiration) { htobe64buf (GetHeaderBuffer () + I2NP_HEADER_EXPIRATION_OFFSET, expiration); };
uint64_t GetExpiration () const { return bufbe64toh (GetHeaderBuffer () + I2NP_HEADER_EXPIRATION_OFFSET); };
uint16_t GetSize () const { return bufbe16toh (GetHeaderBuffer () + I2NP_HEADER_SIZE_OFFSET); };
void UpdateSize () { htobe16buf (GetHeaderBuffer () + I2NP_HEADER_SIZE_OFFSET, GetPayloadLength ()); };
void UpdateChks ()
{
uint8_t hash[32];
CryptoPP::SHA256().CalculateDigest(hash, GetPayload (), GetPayloadLength ());
GetHeaderBuffer ()[I2NP_HEADER_CHKS_OFFSET] = hash[0];
}
// payload
uint8_t * GetPayload () { return GetBuffer () + sizeof(I2NPHeader); };
uint8_t * GetBuffer () { return buf + offset; };
const uint8_t * GetBuffer () const { return buf + offset; };
size_t GetLength () const { return len - offset; };
size_t GetLength () const { return len - offset; };
size_t GetPayloadLength () const { return GetLength () - sizeof(I2NPHeader); };
void Align (size_t alignment)
{
size_t rem = ((size_t)GetBuffer ()) % alignment;