RetroShare/libretroshare/src/serialiser/rsserializer.h
2017-05-03 22:43:16 +02:00

300 lines
11 KiB
C++

/*
* libretroshare/src/serialiser: rsserializer.h
*
* RetroShare Serialiser.
*
* Copyright 2016 by Cyril Soler
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License Version 2 as published by the Free Software Foundation.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA.
*
* Please report all bugs and problems to "csoler@users.sourceforge.net".
*
*/
#pragma once
///////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Retroshare Serialization code //
///////////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// Classes
// =======
//
// RsSerialiser ----------------+ std::map<uint32_t, RsSerialType*>
//
// RsSerialType
// |
// +----------- RsRawSerializer
// |
// +----------- RsGenericSerializer
// |
// +----------- RsConfigSerializer
// | |
// | +----------- Specific config serializers
// | +----------- ...
// |
// +----------- RsServiceSerializer
// |
// +----------- Specific service serializers
// +----------- ...
// +----------- ...
//
//
// Steps to derive a serializer for a new service:
// ==============================================
//
// 1 - create a serializer class, and overload create_item() to create a new item of your own service for each item type constant:
//
// class MyServiceSerializer: public RsServiceSerializer
// {
// MyServiceSerializer() : RsServiceSerializer(MY_SERVICE_IDENTIFIER) {}
//
// RsItem *create_item(uint16_t service,uint8_t item_subtype) const // mind the "const"!
// {
// if(service != MY_SERVICE_IDENTIFIER) return NULL ;
//
// switch(item_subtype)
// {
// case MY_ITEM_SUBTYPE_01: return new MyServiceItem();
// default:
// return NULL ;
// }
// }
// }
//
// 2 - create your own items, and overload serial_process in order to define the serialized structure:
//
// class MyServiceItem: public RsItem
// {
// virtual void serial_process(RsGenericSerializer::SerializeJob j,RsGenericSerializer::SerializeContext& ctx)
// {
// RsTypeSerializer::serial_process<uint32_t> (j,ctx,count,"count") ; // uint32_t is not really needed here, except for explicitly avoiding int types convertion
// RsTypeSerializer::serial_process (j,ctx,update_times,"update_times") ; // will serialize the map and its content
// RsTypeSerializer::serial_process<RsTlvItem>(j,ctx,key,"key") ; // note the explicit call to TlvItem
// RsTypeSerializer::serial_process (j,ctx,dh_key,"dh_key") ; // template will automatically require serialise/deserialise/size/print_data for your type
// }
//
// private:
// uint32_t count ; // example of an int type. All int sizes are supported
// std::map<uint32_t,time_t> update_times ; // example of a std::map. All std containers are supported.
// RsTlvSecurityKey key ; // example of a TlvItem class.
// BIGNUM *dh_key; // example of a class that needs its own serializer (see below)
// };
//
// Some types may not be already handled by RsTypeSerializer, so in this case, you need to specialise the template for your own type. But this is quite unlikely to
// happen. In most cases, for instance in your structure types, serialization is directly done by calling RsTypeSerializer::serial_process() on each member of the type.
// In case you really need a specific serialization for soe particular type, here is how to do it, with the example of BIGNUM* (a crypto primitive):
//
// template<> bool RsTypeSerializer::serialize(uint8_t data[], uint32_t size, uint32_t &offset, BIGNUM * const & member)
// {
// uint32_t s = BN_num_bytes(member) ;
//
// if(size < offset + 4 + s)
// return false ;
//
// bool ok = true ;
// ok &= setRawUInt32(data, size, &offset, s);
//
// BN_bn2bin(member,&((unsigned char *)data)[offset]) ;
// offset += s ;
//
// return ok;
// }
// template<> bool RsTypeSerializer::deserialize(const uint8_t data[], uint32_t size, uint32_t &offset, BIGNUM *& member)
// {
// uint32_t s=0 ;
// bool ok = true ;
// ok &= getRawUInt32(data, size, &offset, &s);
//
// if(s > size || size - s < offset)
// return false ;
//
// member = BN_bin2bn(&((unsigned char *)data)[offset],s,NULL) ;
// offset += s ;
//
// return ok;
// }
// template<> uint32_t RsTypeSerializer::serial_size(BIGNUM * const & member)
// {
// return 4 + BN_num_bytes(member) ;
// }
// template<> void RsTypeSerializer::print_data(const std::string& name,BIGNUM * const & /* member */)
// {
// std::cerr << "[BIGNUM] : " << name << std::endl;
// }
//
// 3 - in your service, overload the serialiser declaration to add your own:
//
// MyService::MyService()
// {
// addSerialType(new MyServiceSerializer()) ;
// }
//
// If needed, you may serialize your own items by calling:
//
// uint32_t size = MySerializer().size(item) ;
// uint8_t *data = (uint8_t*)malloc(size);
// MySerializer().serialise(item,data,size) ;
//
// 4 - in your service, receive and send items by calling recvItem() and sendItem() respectively.
//
#include <stdint.h>
#include <string.h>
#include <iostream>
#include <string>
#include "retroshare/rsflags.h"
#include "serialiser/rsserial.h"
class RsItem ;
#define SERIALIZE_ERROR() std::cerr << __PRETTY_FUNCTION__ << " : "
// This is the base class for serializers.
class RsSerialType
{
public:
RsSerialType(uint32_t t); /* only uses top 24bits */
RsSerialType(uint8_t ver, uint8_t cls, uint8_t t);
RsSerialType(uint8_t ver, uint16_t service);
virtual ~RsSerialType();
virtual uint32_t size(RsItem *)=0;
virtual bool serialise (RsItem *item, void *data, uint32_t *size)=0;
virtual RsItem * deserialise(void *data, uint32_t *size)=0;
uint32_t PacketId() const;
private:
uint32_t type;
};
// This class is only used internally to p3service. It should not be used explicitely otherwise.
class RsRawSerialiser: public RsSerialType
{
public:
RsRawSerialiser() :RsSerialType(RS_PKT_VERSION_SERVICE, 0, 0) {}
virtual ~RsRawSerialiser() { }
virtual uint32_t size(RsItem *);
virtual bool serialise (RsItem *item, void *data, uint32_t *size);
virtual RsItem * deserialise(void *data, uint32_t *size);
};
// Top class for all services and config serializers.
class RsGenericSerializer: public RsSerialType
{
public:
typedef enum { SIZE_ESTIMATE = 0x01, SERIALIZE = 0x02, DESERIALIZE = 0x03, PRINT=0x04 } SerializeJob ;
typedef enum { FORMAT_BINARY = 0x01, FORMAT_JSON = 0x02 } SerializationFormat ;
class SerializeContext
{
public:
SerializeContext(uint8_t *data,uint32_t size,SerializationFormat format,SerializationFlags flags)
: mData(data),mSize(size),mOffset(0),mOk(true),mFormat(format),mFlags(flags) {}
unsigned char *mData ;
uint32_t mSize ;
uint32_t mOffset ;
bool mOk ;
SerializationFormat mFormat ;
SerializationFlags mFlags ;
};
// These are convenience flags to be used by the items when processing the data. The names of the flags
// are not very important. What matters is that the serial_process() method of each item correctly
// deals with the data when it sees the flags, if the serialiser sets them. By default the flags are not
// set and shouldn't be handled.
// When deriving a new serializer, the user can set his own flags, using compatible values
static const SerializationFlags SERIALIZATION_FLAG_NONE ; // 0x0000
static const SerializationFlags SERIALIZATION_FLAG_CONFIG ; // 0x0001
static const SerializationFlags SERIALIZATION_FLAG_SIGNATURE ; // 0x0002
static const SerializationFlags SERIALIZATION_FLAG_SKIP_HEADER ; // 0x0004
// The following functions overload RsSerialType. They *should not* need to be further overloaded.
RsItem *deserialise(void *data,uint32_t *size) =0;
bool serialise(RsItem *item,void *data,uint32_t *size) ;
uint32_t size(RsItem *item) ;
void print(RsItem *item) ;
protected:
RsGenericSerializer(uint8_t serial_class,
uint8_t serial_type,
SerializationFormat format,
SerializationFlags flags )
: RsSerialType(RS_PKT_VERSION1,serial_class,serial_type), mFormat(format),mFlags(flags)
{}
RsGenericSerializer(uint16_t service,
SerializationFormat format,
SerializationFlags flags )
: RsSerialType(RS_PKT_VERSION_SERVICE,service), mFormat(format),mFlags(flags)
{}
SerializationFormat mFormat ;
SerializationFlags mFlags ;
};
// Top class for service serializers. Derive your on service serializer from this class and overload creat_item().
class RsServiceSerializer: public RsGenericSerializer
{
public:
RsServiceSerializer(uint16_t service_id,
SerializationFormat format = FORMAT_BINARY,
SerializationFlags flags = SERIALIZATION_FLAG_NONE)
: RsGenericSerializer(service_id,format,flags) {}
/*! create_item
* should be overloaded to create the correct type of item depending on the data
*/
virtual RsItem *create_item(uint16_t /* service */, uint8_t /* item_sub_id */) const=0;
RsItem *deserialise(void *data,uint32_t *size) ;
};
// Top class for config serializers. Config serializers are only used internally by RS core. The development of new services or plugins do not need this.
class RsConfigSerializer: public RsGenericSerializer
{
public:
RsConfigSerializer(uint8_t config_class,
uint8_t config_type,
SerializationFormat format = FORMAT_BINARY,
SerializationFlags flags = SERIALIZATION_FLAG_NONE)
: RsGenericSerializer(config_class,config_type,format,flags) {}
/*! create_item
* should be overloaded to create the correct type of item depending on the data
*/
virtual RsItem *create_item(uint8_t /* item_type */, uint8_t /* item_sub_type */) const=0;
RsItem *deserialise(void *data,uint32_t *size) ;
};