Pcap.cpp revision 0c38d8c7cccfe74a429f34f61add9df945079044
/* $Id$ */
/** @file
* Helpers for writing libpcap files.
*/
/*
* Copyright (C) 2006-2008 Sun Microsystems, Inc.
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* you can redistribute it and/or modify it under the terms of the GNU
* 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.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 USA or visit http://www.sun.com if you need
* additional information or have any questions.
*/
/*******************************************************************************
* Header Files *
*******************************************************************************/
#include "Pcap.h"
#include <iprt/file.h>
#include <iprt/stream.h>
#include <iprt/time.h>
#include <iprt/err.h>
/*******************************************************************************
* Structures and Typedefs *
*******************************************************************************/
/* "libpcap" magic */
#define PCAP_MAGIC 0xa1b2c3d4
/* "libpcap" file header (minus magic number). */
struct pcap_hdr
{
uint16_t version_major; /* major version number = 2 */
uint16_t version_minor; /* minor version number = 4 */
int32_t thiszone; /* GMT to local correction = 0 */
uint32_t sigfigs; /* accuracy of timestamps = 0 */
uint32_t snaplen; /* max length of captured packets, in octets = 0xffff */
uint32_t network; /* data link type = 01 */
};
/* "libpcap" record header. */
struct pcaprec_hdr
{
uint32_t ts_sec; /* timestamp seconds */
uint32_t ts_usec; /* timestamp microseconds */
uint32_t incl_len; /* number of octets of packet saved in file */
uint32_t orig_len; /* actual length of packet */
};
struct pcaprec_hdr_init
{
uint32_t u32Magic;
struct pcap_hdr pcap;
struct pcaprec_hdr rec0;
};
/*******************************************************************************
* Global Variables *
*******************************************************************************/
static pcaprec_hdr_init const s_Hdr =
{
PCAP_MAGIC,
{ 2, 4, 0, 0, 0xffff, 1 },
/* force ethereal to start at 0.000000. */
{ 0, 1, 0, 60 }
};
/**
* Internal helper.
*/
static void pcapCalcHeader(struct pcaprec_hdr *pHdr, uint64_t StartNanoTS, size_t cbFrame, size_t cbMax)
{
uint64_t u64TS = RTTimeNanoTS() - StartNanoTS;
pHdr->ts_sec = (uint32_t)(u64TS / 1000000000);
pHdr->ts_usec = (uint32_t)((u64TS / 1000) % 1000000);
pHdr->incl_len = (uint32_t)RT_MIN(cbFrame, cbMax);
pHdr->orig_len = (uint32_t)cbFrame;
}
/**
* Writes the stream header.
*
* @returns IPRT status code, @see RTStrmWrite.
*
* @param pStream The stream handle.
* @param StartNanoTS What to subtract from the RTTimeNanoTS output.
*/
int PcapStreamHdr(PRTSTREAM pStream, uint64_t StartNanoTS)
{
pcaprec_hdr_init Hdr = s_Hdr;
pcapCalcHeader(&Hdr.rec0, StartNanoTS, 60, 0);
return RTStrmWrite(pStream, &Hdr, sizeof(Hdr));
}
/**
* Writes a frame to a stream.
*
* @returns IPRT status code, @see RTStrmWrite.
*
* @param pStream The stream handle.
* @param StartNanoTS What to subtract from the RTTimeNanoTS output.
* @param pvFrame The start of the frame.
* @param cbFrame The size of the frame.
* @param cbMax The max number of bytes to include in the file.
*/
int PcapStreamFrame(PRTSTREAM pStream, uint64_t StartNanoTS, const void *pvFrame, size_t cbFrame, size_t cbMax)
{
struct pcaprec_hdr Hdr;
pcapCalcHeader(&Hdr, StartNanoTS, cbFrame, cbMax);
int rc1 = RTStrmWrite(pStream, &Hdr, sizeof(Hdr));
int rc2 = RTStrmWrite(pStream, pvFrame, Hdr.incl_len);
return RT_SUCCESS(rc1) ? rc2 : rc1;
}
/**
* Writes the file header.
*
* @returns IPRT status code, @see RTFileWrite.
*
* @param File The file handle.
* @param StartNanoTS What to subtract from the RTTimeNanoTS output.
*/
int PcapFileHdr(RTFILE File, uint64_t StartNanoTS)
{
pcaprec_hdr_init Hdr = s_Hdr;
pcapCalcHeader(&Hdr.rec0, StartNanoTS, 60, 0);
return RTFileWrite(File, &Hdr, sizeof(Hdr), NULL);
}
/**
* Writes a frame to a file.
*
* @returns IPRT status code, @see RTFileWrite.
*
* @param File The file handle.
* @param StartNanoTS What to subtract from the RTTimeNanoTS output.
* @param pvFrame The start of the frame.
* @param cbFrame The size of the frame.
* @param cbMax The max number of bytes to include in the file.
*/
int PcapFileFrame(RTFILE File, uint64_t StartNanoTS, const void *pvFrame, size_t cbFrame, size_t cbMax)
{
struct pcaprec_hdr Hdr;
pcapCalcHeader(&Hdr, StartNanoTS, cbFrame, cbMax);
int rc1 = RTFileWrite(File, &Hdr, sizeof(Hdr), NULL);
int rc2 = RTFileWrite(File, pvFrame, Hdr.incl_len, NULL);
return RT_SUCCESS(rc1) ? rc2 : rc1;
}