/* $Id$ */
/** @file
* IPRT - IPv4 Checksum calculation and validation.
*/
/*
* Copyright (C) 2008-2011 Oracle Corporation
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* General Public License (GPL) as published by the Free Software
* Foundation, in version 2 as it comes in the "COPYING" file of the
* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
*
* The contents of this file may alternatively be used under the terms
* of the Common Development and Distribution License Version 1.0
* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
* VirtualBox OSE distribution, in which case the provisions of the
* CDDL are applicable instead of those of the GPL.
*
* You may elect to license modified versions of this file under the
* terms and conditions of either the GPL or the CDDL or both.
*/
/*******************************************************************************
* Header Files *
*******************************************************************************/
/**
* Calculates the checksum of the IPv4 header.
*
* @returns Checksum (network endian).
* @param pIpHdr Pointer to the IPv4 header to checksum, network endian (big).
* Assumes the caller already checked the minimum size requirement.
*/
{
/*+ paw[5] == 0 */ /* ip_sum */
/* any options */
{
/* this is a bit insane... (identical to the TCP header) */
{
case 9: u32Sum += paw[10] + paw[11] + paw[12] + paw[13] + paw[14] + paw[15] + paw[16] + paw[17]; break;
case 10: u32Sum += paw[10] + paw[11] + paw[12] + paw[13] + paw[14] + paw[15] + paw[16] + paw[17] + paw[18] + paw[19]; break;
case 11: u32Sum += paw[10] + paw[11] + paw[12] + paw[13] + paw[14] + paw[15] + paw[16] + paw[17] + paw[18] + paw[19] + paw[20] + paw[21]; break;
case 12: u32Sum += paw[10] + paw[11] + paw[12] + paw[13] + paw[14] + paw[15] + paw[16] + paw[17] + paw[18] + paw[19] + paw[20] + paw[21] + paw[22] + paw[23]; break;
case 13: u32Sum += paw[10] + paw[11] + paw[12] + paw[13] + paw[14] + paw[15] + paw[16] + paw[17] + paw[18] + paw[19] + paw[20] + paw[21] + paw[22] + paw[23] + paw[24] + paw[25]; break;
case 14: u32Sum += paw[10] + paw[11] + paw[12] + paw[13] + paw[14] + paw[15] + paw[16] + paw[17] + paw[18] + paw[19] + paw[20] + paw[21] + paw[22] + paw[23] + paw[24] + paw[25] + paw[26] + paw[27]; break;
case 15: u32Sum += paw[10] + paw[11] + paw[12] + paw[13] + paw[14] + paw[15] + paw[16] + paw[17] + paw[18] + paw[19] + paw[20] + paw[21] + paw[22] + paw[23] + paw[24] + paw[25] + paw[26] + paw[27] + paw[28] + paw[29]; break;
default:
AssertFailed();
}
}
/* 16-bit one complement fun */
}
/**
* Verifies the header version, header size, packet size, and header checksum
* of the specified IPv4 header.
*
* @returns true if valid, false if invalid.
* @param pIpHdr Pointer to the IPv4 header to validate. Network endian (big).
* @param cbHdrMax The max header size, or the max size of what pIpHdr points
* to if you like. Note that an IPv4 header can be up to 60 bytes.
* @param cbPktMax The max IP packet size, IP header and payload. This doesn't have
* to be mapped following pIpHdr.
* @param fChecksum Whether to validate the checksum (GSO).
*/
RTDECL(bool) RTNetIPv4IsHdrValid(PCRTNETIPV4 pIpHdr, size_t cbHdrMax, size_t cbPktMax, bool fChecksum)
{
/*
* The header fields.
*/
return false;
return false;
{
Assert((size_t)pIpHdr->ip_hl * 4 > cbPktMax); /* You'll hit this if you mapped/copy too little of the header! */
return false;
}
return false;
return false;
/*
* The header checksum if requested.
*/
if (fChecksum)
{
return false;
}
return true;
}
/**
* Calculates the checksum of a pseudo header given an IPv4 header [inlined].
*
* @returns 32-bit intermediary checksum value.
* @param pIpHdr The IP header (network endian (big)).
*/
{
#ifdef RT_BIG_ENDIAN
#else
#endif
+ RT_H2BE_U16(cbPayload);
return u32Sum;
}
/**
* Calculates the checksum of a pseudo header given an IPv4 header.
*
* @returns 32-bit intermediary checksum value.
* @param pIpHdr The IP header (network endian (big)).
*/
{
return rtNetIPv4PseudoChecksum(pIpHdr);
}
/**
* Calculates the checksum of a pseudo header given the individual components.
*
* @returns 32-bit intermediary checksum value.
* @param SrcAddr The source address in host endian.
* @param DstAddr The destination address in host endian.
* @param bProtocol The protocol number.
* @param cbPkt The packet size (host endian of course) (no IPv4 header).
*/
RTDECL(uint32_t) RTNetIPv4PseudoChecksumBits(RTNETADDRIPV4 SrcAddr, RTNETADDRIPV4 DstAddr, uint8_t bProtocol, uint16_t cbPkt)
{
#ifdef RT_BIG_ENDIAN
#else
#endif
+ RT_H2BE_U16(cbPkt);
return u32Sum;
}
/**
* Adds the checksum of the UDP header to the intermediate checksum value [inlined].
*
* @returns 32-bit intermediary checksum value.
* @param pUdpHdr Pointer to the UDP header to checksum, network endian (big).
* @param u32Sum The 32-bit intermediate checksum value.
*/
{
/*+ pUdpHdr->uh_sum = 0 */
return u32Sum;
}
/**
* Adds the checksum of the UDP header to the intermediate checksum value.
*
* @returns 32-bit intermediary checksum value.
* @param pUdpHdr Pointer to the UDP header to checksum, network endian (big).
* @param u32Sum The 32-bit intermediate checksum value.
*/
{
}
/**
* Adds the checksum of the TCP header to the intermediate checksum value [inlined].
*
* @returns 32-bit intermediary checksum value.
* @param pTcpHdr Pointer to the TCP header to checksum, network
* endian (big). Assumes the caller has already validate
* it and made sure the entire header is present.
* @param u32Sum The 32-bit intermediate checksum value.
*/
{
/*+ paw[8] == 0 */ /* th_sum */
{
/* this is a bit insane... (identical to the IPv4 header) */
{
case 9: u32Sum += paw[10] + paw[11] + paw[12] + paw[13] + paw[14] + paw[15] + paw[16] + paw[17]; break;
case 10: u32Sum += paw[10] + paw[11] + paw[12] + paw[13] + paw[14] + paw[15] + paw[16] + paw[17] + paw[18] + paw[19]; break;
case 11: u32Sum += paw[10] + paw[11] + paw[12] + paw[13] + paw[14] + paw[15] + paw[16] + paw[17] + paw[18] + paw[19] + paw[20] + paw[21]; break;
case 12: u32Sum += paw[10] + paw[11] + paw[12] + paw[13] + paw[14] + paw[15] + paw[16] + paw[17] + paw[18] + paw[19] + paw[20] + paw[21] + paw[22] + paw[23]; break;
case 13: u32Sum += paw[10] + paw[11] + paw[12] + paw[13] + paw[14] + paw[15] + paw[16] + paw[17] + paw[18] + paw[19] + paw[20] + paw[21] + paw[22] + paw[23] + paw[24] + paw[25]; break;
case 14: u32Sum += paw[10] + paw[11] + paw[12] + paw[13] + paw[14] + paw[15] + paw[16] + paw[17] + paw[18] + paw[19] + paw[20] + paw[21] + paw[22] + paw[23] + paw[24] + paw[25] + paw[26] + paw[27]; break;
case 15: u32Sum += paw[10] + paw[11] + paw[12] + paw[13] + paw[14] + paw[15] + paw[16] + paw[17] + paw[18] + paw[19] + paw[20] + paw[21] + paw[22] + paw[23] + paw[24] + paw[25] + paw[26] + paw[27] + paw[28] + paw[29]; break;
default:
AssertFailed();
}
}
return u32Sum;
}
/**
* Adds the checksum of the TCP header to the intermediate checksum value.
*
* @returns 32-bit intermediary checksum value.
* @param pTcpHdr Pointer to the TCP header to checksum, network
* endian (big). Assumes the caller has already validate
* it and made sure the entire header is present.
* @param u32Sum The 32-bit intermediate checksum value.
*/
{
}
/**
* Adds the checksum of the specified data segment to the intermediate checksum value [inlined].
*
* @returns 32-bit intermediary checksum value.
* @param pvData Pointer to the data that should be checksummed.
* @param cbData The number of bytes to checksum.
* @param u32Sum The 32-bit intermediate checksum value.
* @param pfOdd This is used to keep track of odd bits, initialize to false
* when starting to checksum the data (aka text) after a TCP
* or UDP header (data never start at an odd offset).
*/
DECLINLINE(uint32_t) rtNetIPv4AddDataChecksum(void const *pvData, size_t cbData, uint32_t u32Sum, bool *pfOdd)
{
if (*pfOdd)
{
#ifdef RT_BIG_ENDIAN
/* there was an odd byte in the previous chunk, add the lower byte. */
#else
/* there was an odd byte in the previous chunk, add the upper byte. */
#endif
/* skip the byte. */
cbData--;
if (!cbData)
return u32Sum;
}
/* iterate the data. */
while (cbData > 1)
{
pw++;
cbData -= 2;
}
/* handle odd byte. */
if (cbData)
{
#ifdef RT_BIG_ENDIAN
#else
#endif
*pfOdd = true;
}
else
*pfOdd = false;
return u32Sum;
}
/**
* Adds the checksum of the specified data segment to the intermediate checksum value.
*
* @returns 32-bit intermediary checksum value.
* @param pvData The data bits to checksum.
* @param cbData The number of bytes to checksum.
* @param u32Sum The 32-bit intermediate checksum value.
* @param pfOdd This is used to keep track of odd bits, initialize to false
* when starting to checksum the data (aka text) after a TCP
* or UDP header (data never start at an odd offset).
*/
RTDECL(uint32_t) RTNetIPv4AddDataChecksum(void const *pvData, size_t cbData, uint32_t u32Sum, bool *pfOdd)
{
}
/**
* Finalizes a IPv4 checksum [inlined].
*
* @returns The checksum (network endian).
* @param u32Sum The 32-bit intermediate checksum value.
*/
{
/* 16-bit one complement fun */
}
/**
* Finalizes a IPv4 checksum.
*
* @returns The checksum (network endian).
* @param u32Sum The 32-bit intermediate checksum value.
*/
{
return rtNetIPv4FinalizeChecksum(u32Sum);
}
/**
* Calculates the checksum for the UDP header given the UDP header w/ payload
* and the checksum of the pseudo header.
*
* @returns The checksum (network endian).
* @param u32Sum The checksum of the pseudo header. See
* RTNetIPv4PseudoChecksum and RTNetIPv6PseudoChecksum.
* @param pUdpHdr Pointer to the UDP header and the payload, in
* network endian (big). We use the uh_ulen field to
* figure out how much to checksum.
*/
{
bool fOdd;
fOdd = false;
u32Sum = rtNetIPv4AddDataChecksum(pUdpHdr + 1, RT_BE2H_U16(pUdpHdr->uh_ulen) - sizeof(*pUdpHdr), u32Sum, &fOdd);
return rtNetIPv4FinalizeChecksum(u32Sum);
}
/**
* Calculates the checksum for the UDP header given the IP header,
* UDP header and payload.
*
* @returns The checksum (network endian).
* @param pIpHdr Pointer to the IPv4 header, in network endian (big).
* @param pUdpHdr Pointer to the UDP header, in network endian (big).
* @param pvData Pointer to the UDP payload. The size is taken from the
* UDP header and the caller is supposed to have validated
* this before calling.
*/
{
bool fOdd;
fOdd = false;
u32Sum = rtNetIPv4AddDataChecksum(pvData, RT_BE2H_U16(pUdpHdr->uh_ulen) - sizeof(*pUdpHdr), u32Sum, &fOdd);
return rtNetIPv4FinalizeChecksum(u32Sum);
}
/**
* Simple verification of an UDP packet size.
*
* @returns true if valid, false if invalid.
* @param pIpHdr Pointer to the IPv4 header, in network endian (big).
* This is assumed to be valid and the minimum size being mapped.
* @param pUdpHdr Pointer to the UDP header, in network endian (big).
* @param cbPktMax The max UDP packet size, UDP header and payload (data).
*/
{
/*
* Size validation.
*/
return false;
return false;
return false;
return true;
}
/**
* Simple verification of an UDP packet size.
*
* @returns true if valid, false if invalid.
* @param pIpHdr Pointer to the IPv4 header, in network endian (big).
* This is assumed to be valid and the minimum size being mapped.
* @param pUdpHdr Pointer to the UDP header, in network endian (big).
* @param cbPktMax The max UDP packet size, UDP header and payload (data).
*/
{
}
/**
* Simple verification of an UDP packet (size + checksum).
*
* @returns true if valid, false if invalid.
* @param pIpHdr Pointer to the IPv4 header, in network endian (big).
* This is assumed to be valid and the minimum size being mapped.
* @param pUdpHdr Pointer to the UDP header, in network endian (big).
* @param pvData Pointer to the data, assuming it's one single segment
* and that cbPktMax - sizeof(RTNETUDP) is mapped here.
* @param cbPktMax The max UDP packet size, UDP header and payload (data).
* @param fChecksum Whether to validate the checksum (GSO).
*/
RTDECL(bool) RTNetIPv4IsUDPValid(PCRTNETIPV4 pIpHdr, PCRTNETUDP pUdpHdr, void const *pvData, size_t cbPktMax, bool fChecksum)
{
return false;
{
return false;
}
return true;
}
/**
* Calculates the checksum for the TCP header given the IP header,
* TCP header and payload.
*
* @returns The checksum (network endian).
* @param pIpHdr Pointer to the IPv4 header, in network endian (big).
* @param pTcpHdr Pointer to the TCP header, in network endian (big).
* @param pvData Pointer to the TCP payload. The size is derived from
* the two headers and the caller is supposed to have
* validated this before calling. If NULL, we assume
* the data follows immediately after the TCP header.
*/
{
bool fOdd;
fOdd = false;
return rtNetIPv4FinalizeChecksum(u32Sum);
}
/**
* Calculates the checksum for the TCP header given the TCP header, payload and
* the checksum of the pseudo header.
*
* This is not specific to IPv4.
*
* @returns The checksum (network endian).
* @param u32Sum The checksum of the pseudo header. See
* RTNetIPv4PseudoChecksum and RTNetIPv6PseudoChecksum.
* @param pTcpHdr Pointer to the TCP header, in network endian (big).
* @param pvData Pointer to the TCP payload.
* @param cbData The size of the TCP payload.
*/
RTDECL(uint16_t) RTNetTCPChecksum(uint32_t u32Sum, PCRTNETTCP pTcpHdr, void const *pvData, size_t cbData)
{
bool fOdd;
fOdd = false;
return rtNetIPv4FinalizeChecksum(u32Sum);
}
/**
* Verification of a TCP header.
*
* @returns true if valid, false if invalid.
* @param pIpHdr Pointer to the IPv4 header, in network endian (big).
* This is assumed to be valid and the minimum size being mapped.
* @param pTcpHdr Pointer to the TCP header, in network endian (big).
* @param cbHdrMax The max TCP header size (what pTcpHdr points to).
* @param cbPktMax The max TCP packet size, TCP header and payload (data).
*/
DECLINLINE(bool) rtNetIPv4IsTCPSizeValid(PCRTNETIPV4 pIpHdr, PCRTNETTCP pTcpHdr, size_t cbHdrMax, size_t cbPktMax)
{
/*
* Size validations.
*/
return false;
return false;
return false;
return true;
}
/**
* Simple verification of an TCP packet size.
*
* @returns true if valid, false if invalid.
* @param pIpHdr Pointer to the IPv4 header, in network endian (big).
* This is assumed to be valid and the minimum size being mapped.
* @param pTcpHdr Pointer to the TCP header, in network endian (big).
* @param cbHdrMax The max TCP header size (what pTcpHdr points to).
* @param cbPktMax The max TCP packet size, TCP header and payload (data).
*/
RTDECL(bool) RTNetIPv4IsTCPSizeValid(PCRTNETIPV4 pIpHdr, PCRTNETTCP pTcpHdr, size_t cbHdrMax, size_t cbPktMax)
{
}
/**
* Simple verification of an TCP packet (size + checksum).
*
* @returns true if valid, false if invalid.
* @param pIpHdr Pointer to the IPv4 header, in network endian (big).
* This is assumed to be valid and the minimum size being mapped.
* @param pTcpHdr Pointer to the TCP header, in network endian (big).
* @param cbHdrMax The max TCP header size (what pTcpHdr points to).
* @param pvData Pointer to the data, assuming it's one single segment
* and that cbPktMax - sizeof(RTNETTCP) is mapped here.
* If NULL then we assume the data follows immediately after
* the TCP header.
* @param cbPktMax The max TCP packet size, TCP header and payload (data).
* @param fChecksum Whether to validate the checksum (GSO).
*/
RTDECL(bool) RTNetIPv4IsTCPValid(PCRTNETIPV4 pIpHdr, PCRTNETTCP pTcpHdr, size_t cbHdrMax, void const *pvData, size_t cbPktMax,
bool fChecksum)
{
return false;
if (fChecksum)
{
return false;
}
return true;
}
/**
* Minimal validation of a DHCP packet.
*
* This will fail on BOOTP packets (if sufficient data is supplied).
* It will not verify the source and destination ports, that's the
* caller's responsibility.
*
* This function will ASSUME that the hardware type is ethernet
*
* @returns true if valid, false if invalid.
* @param pUdpHdr Pointer to the UDP header, in network endian (big).
* This is assumed to be valid and fully mapped.
* @param pDhcp Pointer to the DHCP packet.
* This might not be the entire thing, see cbDhcp.
* @param cbDhcp The number of valid bytes that pDhcp points to.
* @param pMsgType Where to store the message type (if found).
* This will be set to 0 if not found and on failure.
*/
RTDECL(bool) RTNetIPv4IsDHCPValid(PCRTNETUDP pUdpHdr, PCRTNETBOOTP pDhcp, size_t cbDhcp, uint8_t *pMsgType)
{
if (pMsgType)
*pMsgType = 0;
/*
* Validate all the header fields we're able to...
*/
return true;
return false;
return true;
return false;
return true;
return false;
return true;
return false;
/*
* Check the DHCP cookie and make sure it isn't followed by an END option
* (because that seems to be indicating that it's BOOTP and not DHCP).
*/
cbLeft = (ssize_t)cbDhcp - RT_OFFSETOF(RTNETBOOTP, bp_vend.Dhcp.dhcp_cookie) + sizeof(pDhcp->bp_vend.Dhcp.dhcp_cookie);
if (cbLeft < 0)
return true;
return false;
if (cbLeft < 1)
return true;
return false;
/*
* Scan the options until we find the message type or run out of message.
*
* We're not strict about termination (END) for many reasons, however,
* we don't accept END without MSG_TYPE.
*/
MsgType = 0;
while (cbLeft > 0)
{
{
/* Fail if no MSG_TYPE. */
if (!MsgType)
return false;
break;
}
{
cbLeft--;
}
else
{
{
case RTNET_DHCP_OPT_MSG_TYPE:
{
if (cbLeft < 3)
return true;
switch (MsgType)
{
case RTNET_DHCP_MT_DISCOVER:
case RTNET_DHCP_MT_OFFER:
case RTNET_DHCP_MT_REQUEST:
case RTNET_DHCP_MT_DECLINE:
case RTNET_DHCP_MT_ACK:
case RTNET_DHCP_MT_NAC:
case RTNET_DHCP_MT_RELEASE:
case RTNET_DHCP_MT_INFORM:
break;
default:
/* we don't know this message type, fail. */
return false;
}
/* Found a known message type, consider the job done. */
if (pMsgType)
return true;
}
}
/* Skip the option. */
}
}
return true;
}