tinySNMP.cpp

#include "tinySNMP.h"

#define DEBUG

void packetSNMPprint(byte _packet[],int _packetSize)
{
	//print packet
	
	Serial.println("Packet = byte - int - char");
	for(int n = 0;n < _packetSize;n++)
	{
		Serial.print("p[");
		Serial.print(n); 
		Serial.print("]= 0x"); 
		Serial.print(byte(_packet[n]),HEX);
		Serial.print('\t');
		Serial.print(int(_packet[n]),DEC);
		Serial.print('\t');
		Serial.println(char(_packet[n]));
	}	
}

int packetSNMPcheck(byte _packet[],int _packetSize) //check SNMP
{
	//packet check max size
	if(_packetSize > SNMP_MAX_PACKET_LEN)
	{
#ifdef DEBUG
		Serial.println("SNMP big size");
#endif
		return SNMP_ERR_TOO_BIG;
	}
	
	//packet check to SNMP and size
	if( (byte(_packet[0]) != 0x30 ) || ((_packetSize-2)!= int(_packet[1]) ) )
	{
#ifdef DEBUG
		Serial.println("SNMP size invalid");
#endif
		return SNMP_ERR_GEN_ERROR;
	}

	//check version SNMP
	if(int(_packet[4]) > SNMP_VERSION) 
	{
#ifdef DEBUG
		Serial.println("SNMP version invalid");
#endif
		return SNMP_ERR_GEN_ERROR;
	}
#ifdef DEBUG
	Serial.println("SNMP packet OK");
#endif
	return SNMP_ERR_NO_ERROR;
}

int packetSNMPcommunity(byte _packet[],int _packetSize,char _community[],int _communitySize)
{	
	//community length
	int _comLen = _packet[6];
	//check community	
	if(_communitySize != _comLen)
	{
		return SNMP_ERR_NO_SUCH_NAME;
	}
	else
	{	
		for (int i=0;i < _comLen;i++)
		{
			if(_community[i] != _packet[7+i]) 
			{
#ifdef DEBUG
				Serial.println("SNMP community invalid");
#endif			
				return SNMP_ERR_NO_SUCH_NAME;
			}

		}
	}
	return SNMP_ERR_NO_ERROR;
}

int packetSNMPread(byte _packet[],int _packetSize, struct OID *_oid)
{
	//length community
	_oid->SNMPcommLen = _packet[6];
	//community
	for(unsigned int i = 0;i < _oid->SNMPcommLen;i++ )
	{
		_oid->SNMPcomm[i] = _packet[6 + 1 + i];
	}
	//pdu
	_oid->SNMPpduType = _packet[6 + _oid->SNMPcommLen + 1];
	unsigned int _pduLen = _packet[6 + _oid->SNMPcommLen + 2];
	//request id
	_oid->SNMPridType = _packet[6 + _oid->SNMPcommLen + 3];
	_oid->SNMPridLen = _packet[6 + _oid->SNMPcommLen + 4];
	for (unsigned int i = 0;i < _oid->SNMPridLen;i++)
	{
		_oid->SNMPrid[i] = _packet[6 + _oid->SNMPcommLen + 4 + 1 + i];
	}
	//error
	_oid->SNMPerrType = _packet[6 + _oid->SNMPcommLen + 4 + _oid->SNMPridLen + 1];
	_oid->SNMPerrLen = _packet[6 + _oid->SNMPcommLen + 4 + _oid->SNMPridLen + 2];
	for(unsigned int i = 0;i < _oid->SNMPerrLen;i++ )
	{
		_oid->SNMPerr[i] = _packet[6 + _oid->SNMPcommLen + 4 + _oid->SNMPridLen + 2 + 1 + i];
	}
	//error index
	_oid->SNMPeriType = _packet[6 + _oid->SNMPcommLen + 4 + _oid->SNMPridLen + 2 + _oid->SNMPerrLen + 1];
	_oid->SNMPeriLen = _packet[6 + _oid->SNMPcommLen + 4 + _oid->SNMPridLen + 2 + _oid->SNMPerrLen + 2];
	for(unsigned int i = 0;i < _oid->SNMPeriLen;i++ )
	{
		_oid->SNMPeri[i] = _packet[6 + _oid->SNMPcommLen + 4 + _oid->SNMPridLen + 2 + _oid->SNMPerrLen + 2 + 1 + i];
	}
	//varbind list
	byte _vblType = _packet[6 + _oid->SNMPcommLen + 4 + _oid->SNMPridLen + 2 + _oid->SNMPerrLen + 2 + _oid->SNMPeriLen + 1];
	unsigned int _vblLen = _packet[6 + _oid->SNMPcommLen + 4 + _oid->SNMPridLen + 2 + _oid->SNMPerrLen + 2 + _oid->SNMPeriLen + 2];
	//varbind
	byte _vbiType = _packet[6 + _oid->SNMPcommLen + 4 + _oid->SNMPridLen + 2 + _oid->SNMPerrLen + 2 + _oid->SNMPeriLen + 3];
	unsigned int _vbiLen = _packet[6 + _oid->SNMPcommLen + 4 + _oid->SNMPridLen + 2 + _oid->SNMPerrLen + 2 + _oid->SNMPeriLen + 4];
	//object id
	_oid->SNMPoidType = _packet[6 + _oid->SNMPcommLen + 4 + _oid->SNMPridLen + 2 + _oid->SNMPerrLen + 2 + _oid->SNMPeriLen + 5];
	_oid->SNMPoidLen = _packet[6 + _oid->SNMPcommLen + 4 + _oid->SNMPridLen + 2 + _oid->SNMPerrLen + 2 + _oid->SNMPeriLen + 6];
	for (unsigned int i=0;i < _oid->SNMPoidLen;i++)
	{
		_oid->SNMPoid[i] = byte(_packet[6 + _oid->SNMPcommLen + 4 + _oid->SNMPridLen + 2 + _oid->SNMPerrLen + 2 + _oid->SNMPeriLen + 6 + 1 + i]);
	}
	//value oid
	byte _valueType = _packet[6 + _oid->SNMPcommLen + 4 + _oid->SNMPridLen + 2 + _oid->SNMPerrLen + 2 + _oid->SNMPeriLen + 6 + _oid->SNMPoidLen + 1];
	unsigned int _valueLen = _packet[6 + _oid->SNMPcommLen + 4 + _oid->SNMPridLen + 2 + _oid->SNMPerrLen + 2 + _oid->SNMPeriLen + 6 + _oid->SNMPoidLen + 2];

	if(_oid->SNMPoidLen > 0 && _oid->SNMPoidLen <= SNMP_MAX_OID_SIZE)
	{
/*		for (int i=0;i <= _oidLen;i++)
		{
			_oid->SNMPoid[i] = byte(_packet[6 + _oid->SNMPcommLen + 4 + _oid->SNMPridLen + 2 + _oid->SNMPerrLen + 2 + _oid->SNMPeriLen + 7 + i]);
			//Serial.println(byte(_oid.oid[i]),HEX);
		}

		//read value
		if(_valueType != SNMP_TYPE_NULL && _valueLen > 0) //NULL
		{
			for (int i=0;i <= _valueLen;i++)
			{
				_oid->SNMPval[i] = byte(_packet[6 + _oid->SNMPcommLen + 4 + _oid->SNMPridLen + 2 + _oid->SNMPerrLen + 2 + _oid->SNMPeriLen + 6 + _oid->SNMPoidLen + 3 + i]);
			}
		}
*/		return 0;
	}
	else
	{
		return 1;
	}

}

unsigned int checkOID( struct OID *_oid)
{
	//general
	//{0x2B,0x6,0x1,0x2,0x1,0x1,x(1-6),0x0}
	if(_oid->SNMPoid[0] == 0x2B &&
		_oid->SNMPoid[1] == 0x6 &&
		_oid->SNMPoid[2] == 0x1 &&
		_oid->SNMPoid[3] == 0x2 &&
		_oid->SNMPoid[4] == 0x1 &&
		_oid->SNMPoid[5] == 0x1 &&
		_oid->SNMPoid[7] == 0x0)
	{
		for(unsigned int i=1;i<=6;i++)
		{
			if (i == (unsigned int)_oid->SNMPoid[6])
			{
				return i;
			}
			else return 0;
		}
	}
	//sensors
	if(_oid->SNMPoid[0] == 0x2B &&
		_oid->SNMPoid[1] == 0x6 &&
		_oid->SNMPoid[2] == 0x1 &&
		_oid->SNMPoid[3] == 0x4 &&
		_oid->SNMPoid[4] == 0x1 &&
		_oid->SNMPoid[5] == 0x82 &&
		_oid->SNMPoid[6] == 0x9D &&
		_oid->SNMPoid[7] == 0x66 &&
		_oid->SNMPoid[10] == 0x0)
	{	
		//analog sensors (.1.3.6.1.4.1.36582.1.x91-16).0)
		//{0x2B,0x6,0x1,0x4,0x1,0x82,0x9D,0x66,0x1,0x1,0x0}
		if(_oid->SNMPoid[8] == 0x1)
		{	
			for(unsigned int i=1;i<=16;i++)
			{
				if (i == (unsigned int)_oid->SNMPoid[9])
					return i+16;
				else return 0;
			}
		}
		//digital sensors (.1.3.6.1.4.1.36582.2.y(1-16).0)
		//{0x2B,0x6,0x1,0x4,0x1,0x82,0x9D,0x66,0x2,0x1,0x0}
		if(_oid->SNMPoid[8] == 0x2)
		{
			for(unsigned int i=1;i<=16;i++)
			{
				if (i == (unsigned int)_oid->SNMPoid[9])
					return i+64;
				else return 0;
			}
		}
	}
	return 0;
}