www.pudn.com > pppcode.rar > ppp.c

/*///////////////////////////////////////////////////////////////////////////// 
File Name : PPP.C 
Author : Rene Trenado 
Location : Motorola Applications Lab, Baja California 
Date Created : September 2000 
Current Revision : 0.0 
Notes : This file contains the code for the PPP module 
/////////////////////////////////////////////////////////////////////////////*/ 
 
#include  
#include "commdrv.h" 
#include "ppp.h" 
#include "ip.h" 
#include "udp.h" 
#include "icmp.h" 
const char * User = ""; // Username of ISP account 
const char * Password = ""; // Password of username 
/************************* Private Functions *************************/ 
static void HandleLCPOptions (void); 
static void HandleIPCPOptions (void); 
static WORD PPPfcs16 (WORD fcs, BYTE *cp, int len); 
static void RejectProtocol (BYTE *InBuffer); 
////////////////////// Protected ROM Data ///////////////////////// 
static const BYTE PPPData [] = { 
	0xff,0x03,0xc0,0x21,0x02,0x01,0x00,0x04,0x00,0x00 
}; 
static const BYTE LCPTerminate[] = { 
	0xff,0x03,0xc0,0x21,0x05,0x04,0x00,0x04,0x80,0xfe 
}; 
static const unsigned short fcstab[256] = { 
	0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf, 
		0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7, 
		0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e, 
		0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876, 
		0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd, 
		0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5, 
		0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c, 
		0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974, 
		0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb, 
		0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3, 
		0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a, 
		0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72, 
		0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9, 
		0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1, 
		0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738, 
		0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70, 
		0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7, 
		0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff, 
		0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036, 
		0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e, 
		0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5, 
		0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd, 
		0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134, 
		0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c, 
		0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3, 
		0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb, 
		0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232, 
		0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a, 
		0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1, 
		0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9, 
		0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330, 
		0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78 
}; 
///////////////////// Public R A M Data ///////////////////////////// 
volatile BYTE PPPStatus = 0; 
extern BYTE  InBuffer [PPP_BUFFER_SIZE + 1];/// Input Buffer for PPP data 
extern BYTE  OutBuffer[PPP_BUFFER_SIZE + 1];/// Output Buffer for PPP data 
///////////////////// Protected R A M Data ///////////////////////// 
static BYTE *PPP_Packet = InBuffer; 
static volatile BYTE FrameSize = 0; 
//static EventProc PPPEntryProc; 
/*********************************************************************** 
Function : PPPInit 
Parameters : None 
Date : September 2000 
Desc : Initialize the PPP Module 
***********************************************************************/ 
void PPPInit (void) { 
	PPPStatus |= ReSync; 
} 
/*********************************************************************** 
Function : PPPGetInputBuffer 
Parameters : None 
Date : September 2000 
Desc : Returns a PPP Input Buffer pointer to caller 
***********************************************************************/ 
BYTE *PPPGetInputBuffer (void) { 
	return &InBuffer[0]; 
} 
/*********************************************************************** 
Function : PPPGetOutputBuffer 
Parameters : None 
Date : September 2000 
Desc : Returns a pointer to PPP Output Buffer to caller 
***********************************************************************/ 
BYTE *PPPGetOutputBuffer (void) { 
	return &OutBuffer[0]; 
} 
/*********************************************************************** 
Function : PPPfcs16 
Parameters : fcs: current fcs 
cp: pointer to PPP data 
len: size of PPP data 
Date : September 2000 
Desc : Calculate a new fcs given the current fcs and the new data. 
***********************************************************************/ 
static WORD PPPfcs16 (WORD fcs, BYTE *cp, int len) { 
	while (len--) 
		fcs = (fcs >> 8) ^ fcstab[(fcs ^ *cp++) & 0xff]; 
	return (fcs); 
} 
/*********************************************************************** 
Function : public PPPGetChecksum 
Parameters : cp: A pinter to the PPP Packet 
len: Size of PPP Packet 
Date : September 2000 
Desc : Returns the Checksum of the PPP Packet pointed by cp 
***********************************************************************/ 
WORD PPPGetChecksum (register unsigned char *cp, register int len) { 
	return ~PPPfcs16( PPPINITFCS16, cp, len ); 
} 
/*********************************************************************** 
Function : ProcPPPReceive 
Parameters : A Byte character to stream in a PPP Packet 
Date : August 2000 
Desc : This function process a BYTE following HDLC - PPP 
specifications. The Async event on input driver should 
call this function (usually the COMM ISR). 
***********************************************************************/ 
void ProcPPPReceive (register BYTE c) { 
	PPPStatus |= ByteRx; 
	if (PPPStatus & IsFrame) return; 
	if (PPPStatus & ReSync) { 
		if (c != 0x7E) return; 
		PPPStatus &= ~ReSync; 
		FrameSize = 0; 
	} 
	if (PPPStatus & IsESC) { 
		PPP_Packet [FrameSize++] = 0x20 ^ c; 
		PPPStatus &= ~IsESC; 
	} 
	else { 
		switch (c) { 
case ESC: // Special ESC (0x7D) Character received 
	PPPStatus |= IsESC; 
	break; 
case END: // Special END (0x7E) Character received 
	// Avoid zero length packets (0x7F - 0x7F 
	// conditions); 
	if (FrameSize > 0) { 
		PPP_Packet [FrameSize] = 0; 
		PPPStatus |= IsFrame;// Signal Frame availability 
	} 
	break; 
default: 
	PPP_Packet [FrameSize++] = c; 
	if (FrameSize > (PPP_BUFFER_SIZE - 6)) { 
		FrameSize = 0; 
		PPPStatus |= ReSync; 
	} 
	break; 
		} 
	} 
} 
/*********************************************************************** 
Function : PPPSend 
Parameters : Buffer: A pointer to a buffer containing the PPP packet to send 
len: the size of the PPP packet 
Date : September 2000 
Desc : Sends a BYTE array of len length following HDLC - PPP specifications 
***********************************************************************/ 
void ProcPPPSend (BYTE *Buffer, BYTE len) { 
	WORD Checksum = 0; 
	Checksum = PPPGetChecksum (Buffer, Buffer[7] + 4); 
	Buffer [Buffer[7]+4] = Checksum & 0xFF; 
	Buffer [Buffer[7]+5] = (Checksum >> 8) & 0xFF; 
	WriteComm (0x7E); 
	while (len--) { 
		if ((signed char)*Buffer < (signed char)0x20) { 
			WriteComm (0x7D); 
			WriteComm (*Buffer ^ 0x20); 
		} else { 
			switch (*Buffer) { 
case 0x7E: 
	WriteComm (0x7D); 
	WriteComm (0x5E); 
	break; 
case 0x7D: 
	WriteComm (0x7D); 
	WriteComm (0x5D); 
	break; 
default: 
	WriteComm (*Buffer); 
	break; 
			} 
		} 
		Buffer++; 
	} 
	WriteComm (0x7E); 
} 
/*********************************************************************** 
Function : public PPPFrameSize 
Parameters : None 
Date : August 2000 
Desc : Returns the size of the current available PPP packet 
stored in InBuffer. Caller should call this function 
if needed only when the IsFram flag has been signaled. 
***********************************************************************/ 
BYTE PPPFrameSize (void) { 
	return FrameSize; 
} 
/*********************************************************************** 
Function : protected HandleLCPOptions 
Parameters : None 
Date : August 2000 
Desc : State Machine that implements LCP packet negotiation 
***********************************************************************/ 
static void HandleLCPOptions (void) { 
	BYTE *dest = OutBuffer; // A pointer to the options of output buffer 
	BYTE *ptr = (BYTE *)&InBuffer[8]; // A pointer to the options of input buffer 
	switch (InBuffer [4] ) { 
		//++++++++++++++++++++++++++++++++++++++++++++++++++++ 
case TERMINATE: //Server Terminate-Request received 
	Move (InBuffer, OutBuffer, InBuffer[7]+6); 
	OutBuffer [4] = TERMINATE_ACK; 
	ProcPPPSend ((BYTE *)OutBuffer, OutBuffer[7] + 6); 
	PPPStatus &= ~LinkOn; 
	break; 
	//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 
case REQ: 
	////////////////////////////////////////////////////////////////////// 
	/////// Server requesting option 2 /////// 
	////////////////////////////////////////////////////////////////////// 
	if ((InBuffer [8] == 0x02) && (InBuffer [7] <= 0x0A)) { 
		if ((InBuffer [10] == 0xFF) && 
			(InBuffer [11] == 0xFF) && 
			(InBuffer [12] == 0xFF) && 
			(InBuffer [13] == 0xFF)) { 
				InBuffer [4] = ACK; 
				ProcPPPSend (InBuffer, InBuffer [7] + 6); 
				return; 
			} 
	} else 
		////////////////////////////////////////////////////////////////////// 
		/////// Server requesting first options, reject all but 3 /////// 
		////////////////////////////////////////////////////////////////////// 
		if ((InBuffer [8] != 0x03) && (InBuffer [7] > 9)) { 
			BYTE OptionsSize; 
			BYTE Option; 
			BYTE Size; 
			Move (InBuffer, OutBuffer, 8);// Move LCP header to output buffer 
			OutBuffer [4] = REJ; // Output will be a reject packet 
			dest += 8; // Offset output pointer to 
			// LCP options 
			OptionsSize = InBuffer[7] - 4; // Get size of LCP 
			// options 
			while (OptionsSize > 0) { // Is there options to 
				// process? 
				Option = *ptr; // Get option number 
				Size = *(ptr + 1); // Get size of this option 
				OptionsSize -= Size; // Reduce the amount of 
				// OptionsSize 
				if (Option == 3) { // Is this option 3? 
					// (authentication protocol) 
					ptr += Size; // Remove this option in 
					// output packet 
					// Set New Packet size 
					OutBuffer [7] = OutBuffer [7] - Size; 
				} 
				else { 
					// Copy this option to the output buffer 
					while (Size-- ) { 
						*dest++ = *ptr++; 
					} 
				} 
			} 
		} else 
			////////////////////////////////////////////////////////////////////// 
			/////// Server Request CHAP protocol, We reply with 
			/////// a suggestion of the PAP protocol instead 
			////////////////////////////////////////////////////////////////////// 
			if ((InBuffer [8] == 0x03) && (InBuffer [10] == 0xC2)) { 
				InBuffer [4] = NAK; // NAK CHAP protocol 
				InBuffer [10] = 0xC0; // We suggest PAP instead 
				// Send the NAK reply 
				ProcPPPSend (InBuffer, InBuffer[7]+6); 
				return; 
			} else 
				////////////////////////////////////////////////////////////////////// 
				/////// Server Request PAP protocol ////////// 
				/////// We Acknowledge this reply and then we start negotiating 
				/////// the Async-Control-Char..., Here we send both packets!!! 
				////////////////////////////////////////////////////////////////////// 
				if ((InBuffer [8] == 0x03) && (InBuffer [10] == 0xC0)) { 
					Move (InBuffer, OutBuffer, InBuffer[7]+6); 
					OutBuffer[4] = ACK; 
					ProcPPPSend ((BYTE *)OutBuffer, OutBuffer[7] + 6); 
					OutBuffer[4] = REQ; 
					OutBuffer[5] = OutBuffer [5] + 1; 
					OutBuffer[7] = 0x0A; 
					OutBuffer[8] = 0x02; 
					OutBuffer[9] = 0x06; 
					OutBuffer[10] = 0xFF; 
					OutBuffer[11] = 0xFF; 
					OutBuffer[12] = 0xFF; 
					OutBuffer[13] = 0xFF; 
				} 
				ProcPPPSend ((BYTE *)OutBuffer, OutBuffer[7] + 6); 
				break; 
				//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 
case ACK: 
	////////////////////////////////////////////////////////////////////// 
	/////// Server Acknowledge Async Control ////////// 
	////////////////////////////////////////////////////////////////////// 
	if (InBuffer [8] == 0x02) { 
		SendPAPPacket (REQ, User, Password); 
	} 
	break; 
	//++++++++++++++++++++++++++++++++++++++++++++++++++++ 
case NAK: 
	break; 
	//++++++++++++++++++++++++++++++++++++++++++++++++++++ 
case REJ: 
	break; 
	//++++++++++++++++++++++++++++++++++++++++++++++++++++ 
case TERMINATE_ACK: // Terminate ACK! 
	PPPStatus &= ~LinkOn; 
	break; 
	} 
	return; 
} 
/*********************************************************************** 
Function : protected HandleIPCPOptions 
Parameters : None 
Date : August 2000 
Desc : State Machine that implement IPCP packet negotiation 
***********************************************************************/ 
static void HandleIPCPOptions (void) { 
	BYTE *dest = (BYTE *)&OutBuffer[8]; 
	BYTE *ptr = (BYTE *)&InBuffer[8]; 
	BYTE FrameSize; 
	BYTE Option; 
	BYTE Size; 
	switch (InBuffer [4] ) { 
case REQ: 
	if ((InBuffer [8] != 0x03) && (InBuffer [7] > 0x0A)) { 
		OutBuffer [0] = 0xFF; // Build a IPCP header 
		OutBuffer [1] = 0x03; 
		OutBuffer [2] = 0x80; // Set IPCP protocol 
		OutBuffer [3] = 0x21; 
		OutBuffer [4] = REJ; // This will be a 
		// REJ packet for now 
		OutBuffer [5] = InBuffer [5]; 
		FrameSize = InBuffer[7] - 4; 
		///////// Ignore all but option #3 /////// 
		while (FrameSize > 0) { 
			Option = *ptr; 
			Size = *(ptr + 1); 
			FrameSize -= Size; 
			if (Option == 3) { 
				ptr += Size; 
				//Set New Packet size 
				OutBuffer [7] = InBuffer [7] - Size; 
			} 
			else { 
				while (Size-- ) { 
					*dest++ = *ptr++; 
				} 
			} 
		} 
	} 
	else { 
		// Acknowledge IP Address // 
		Move (InBuffer, OutBuffer, InBuffer[7]+6); 
		OutBuffer [4] = ACK; 
		ProcPPPSend ((BYTE *)OutBuffer, OutBuffer[7] + 6); 
		// Now Request IP address to complete 3-way handshake 
		OutBuffer [4] = REQ; // Request command 
		OutBuffer [5] = OutBuffer [5] + 1; // Packet ID = ID + 1 
		OutBuffer [10] = 0; // IP address is set 
		// to 0 so ISP server 
		OutBuffer [11] = 0; // can assing us one 
		OutBuffer [12] = 0; 
		OutBuffer [13] = 0; 
	} 
	ProcPPPSend ((BYTE *)OutBuffer, OutBuffer[7] + 6); 
	break; 
case ACK: 
	if (InBuffer [8] == 3) { // Reply of the only IPCP 
		// Request we can send 
		IPAddress [0] = InBuffer [10]; // ISP assigned IP 
		IPAddress [1] = InBuffer [11]; 
		IPAddress [2] = InBuffer [12]; 
		IPAddress [3] = InBuffer [13]; 
		 
		PPPStatus |= LinkOn; // PPP Link is now up 
	} 
	break; 
case NAK: 
	if ((InBuffer[8] == 0x03) && (InBuffer [7] <= 0x0A)) { 
		/// Request IP Address //// 
		Move (InBuffer, OutBuffer, InBuffer[7]+6); 
		OutBuffer[4] = 0x01; 
		ProcPPPSend ((BYTE *)OutBuffer, OutBuffer[7] + 6); 
	} 
	break; 
case REJ: 
	break; 
	} 
} 
/*********************************************************************** 
Function : public PPPSendPAPPacket 
Parameters : Action: REQ, REJ, NAK 
ID: Sequence number of PPP packet 
user: User name for login 
password: Password in plain text 
Date : September 2000 
Desc : Formats a PAP packet on Output Buffer. This function 
supports the type field for future implementation of 
the PPP module in server mode. 
***********************************************************************/ 
void SendPAPPacket (BYTE Action,char* user, char* password) { 
	OutBuffer[0] = 0xFF; 
	OutBuffer[1] = 0x03; 
	OutBuffer[2] = 0xC0; // Format PAP packet header 
	OutBuffer[3] = 0x23; 
	OutBuffer[4] = Action; 
	OutBuffer[5] = InBuffer[5] + 1; // Increment ID 
	OutBuffer[6] = 0; 
	OutBuffer[7] = strlen (user) + strlen (password) + 6;// Set length of PAP 
	OutBuffer[8] = strlen (user); // Set length of 
	// Username 
	Move (user, &OutBuffer [9], strlen (user)); // Store Username 
	OutBuffer [9 + strlen (user)] = strlen (password); // Set length of 
	// password 
	Move (password, &OutBuffer [10 + strlen (user)], strlen (password)); 
	ProcPPPSend ((BYTE *)OutBuffer, OutBuffer[7] + 6); // Send PAP packet 
} 
/*********************************************************************** 
Function : Move 
Parameters : src: A pointer to the data to copy 
dest: A pointer to the destination location 
numBYTEs: Number of bytes to copy 
Date : September 2000 
Desc : Copies a block of numBYTEs bytes from src pointer 
to dest pointer 
***********************************************************************/ 
void Move (BYTE *src, BYTE *dest, register numBYTEs) { 
	if ( numBYTEs <= 0 ) return; 
	if ( src < dest ) { 
		src += numBYTEs; 
		dest += numBYTEs; 
		do { 
			*--dest = *--src; 
		} while ( --numBYTEs > 0 ); 
	} else 
		do { 
			*dest++ = *src++; 
		} while ( --numBYTEs > 0 ); 
} 
/*********************************************************************** 
Function : protected RejectProtocol 
Parameters : InBuffer -> A pointer to the buffer that has the PPP 
Packet to reject 
Date : August 2000 
Desc : Rejects the a PPP packet based on its Protocol field 
Stored on InBuffer 
***********************************************************************/ 
static void RejectProtocol (BYTE *InBuffer) { 
	OutBuffer[0] = 0xFF; 
	OutBuffer[1] = 0x03; 
	OutBuffer[2] = 0xC0; 
	OutBuffer[3] = 0x21; 
	OutBuffer[4] = 0x08; 
	OutBuffer[5] = 20; 
	OutBuffer[6] = 0; 
	OutBuffer[7] = InBuffer[7] + 6; 
	Move (&InBuffer[2], &OutBuffer[8], InBuffer [7] + 2); 
	ProcPPPSend ((BYTE *)OutBuffer, OutBuffer[7] + 6); 
} 
/*********************************************************************** 
Function : protected PPPSendVoidLcp 
Parameters : None 
Date : September 2000 
Desc : Sends a void LCP packet with no options to the PPP Server. 
This will force the server to reply with his options to 
negotiate. Some ISPs require scripts to stablish a connection thus 
a void LCP packet will try to force the server to negotiate PPP. 
***********************************************************************/ 
void PPPSendVoidLCP (void) { 
	 
	Move (PPPData, OutBuffer, PPPData[7] + 6); 
	ProcPPPSend ((BYTE *)OutBuffer, OutBuffer[7] + 6); 
} 
/*********************************************************************** 
Function : PPPTerminate 
Parameters : None 
Date : September 2000 
Desc : Terminates a PPP link by sending a terminate LCP packet 
***********************************************************************/ 
void PPPTerminate (void) { 
	Move ((BYTE *)LCPTerminate, OutBuffer, 10); 
	ProcPPPSend (OutBuffer, 10); 
} 
/*********************************************************************** 
Function : PPPEntry 
Parameters : None 
Date : August 2000 
Desc : PPP Module Entry, Applications should call PPPEntry 
frequently in the main loop or in portions of the app 
code. 
***********************************************************************/ 
void PPPEntry (void) { 
	if (PPPStatus & IsFrame) { 
		switch (*(WORD *)(&InBuffer[2])) { 
case LCP_PACKET: 
	HandleLCPOptions (); 
	break; 
case PAP_PACKET: 
	if (InBuffer[4] == 0x02) {// Authentication OK 
		} 
	break; 
case IPCP_PACKET: // IPCP Handler 
	HandleIPCPOptions (); 
	break; 
case IP_DATAGRAM: // IP Data Handler 
	if (!IPCompare ((BYTE *)&InBuffer[20])) { 
		// Misrouted datagram or broadcast 
		// message received 
	} 
	else 
		switch (InBuffer[13]) { 
case UDP: 
	UDP_Handler ((UDPDatagram *)&InBuffer[16]); 
	break; 
case TCP: 
	break; 
case ICMP: 
	IcmpHandler ((IPDatagram *)&InBuffer[4]); 
	break; 
default: 
	break; 
		} 
		break; 
default: 
	RejectProtocol (InBuffer);// Cannot handle this type of packet 
	break; 
		} // End of switch statement 
		PPPStatus &= ~IsFrame; 
		PPPStatus |= ReSync; 
	} // End of if IsFrame 
}