/*
 * Copyright (c) 2008 CACE Technologies, Davis (California)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * 3. Neither the name of CACE Technologies nor the names of its 
 * contributors may be used to endorse or promote products derived from 
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This sample was contributed by 
 * Marcin Okraszewski (Marcin.OkraszewskiATpl.compuware.com)
 *
 */

#include <tchar.h>
#include <pcap.h>
#include <stdio.h>

BOOL LoadNpcapDlls()
{
    _TCHAR npcap_dir[512];
    UINT len;
    len = GetSystemDirectory(npcap_dir, 480);
    if (!len) {
        fprintf(stderr, "Error in GetSystemDirectory: %x", GetLastError());
        return FALSE;
    }
    _tcscat_s(npcap_dir, 512, _T("\\Npcap"));
    if (SetDllDirectory(npcap_dir) == 0) {
        fprintf(stderr, "Error in SetDllDirectory: %x", GetLastError());
        return FALSE;
    }
    return TRUE;
}

/** Prints packet timestaps regardless of format*/
int _tmain(int argc, _TCHAR* argv[])
{
    char errbuf[PCAP_ERRBUF_SIZE];
    _TCHAR cmd[1024];
    _TCHAR tshark_path[MAX_PATH];
    _TCHAR file_path[MAX_PATH];

    /* Load Npcap and its functions. */
    if (!LoadNpcapDlls())
    {
        fprintf(stderr, "Couldn't load Npcap\n");
        exit(1);
    }

    if ( argc != 3 ) {
        _tprintf(_T("Prints packet timestaps regardless of format.\n"));
        _tprintf(_T("Usage:\n\t%s <tshark path> <trace file>\n"), argv[0]);
        return 1;
    }

    // conversion to short path name in case there are spaces
    if ( ! GetShortPathName(argv[1], tshark_path, MAX_PATH) || 
         ! GetShortPathName(argv[2], file_path, MAX_PATH) )
    {
        _tprintf(_T("Failed to convert paths to short form."));
        return 1;
    }

    // create tshark command, which will make the trace conversion and print in libpcap format to stdout
    if ( _stprintf_s(cmd, 1024, _T("%s -r %s -w - -F libpcap"), tshark_path, file_path) < 0 ) {
        _tprintf(_T("Failed to create command\n"));
        return 1;
    }

    // start tshark
    FILE *tshark_out = _tpopen(cmd, _T("rb"));
    if ( tshark_out == NULL ) {
        strerror_s(errbuf, PCAP_ERRBUF_SIZE, errno);
        printf("Failed run tshark: %s\n", errbuf);
        _tprintf(_T("Command: %s"), cmd);
        return 1;
    }

    // open stdout from tshark
    pcap_t *pcap = pcap_fopen_offline(tshark_out, errbuf);
    if ( pcap == NULL ) {
        printf("Error opening stream from tshark: %s\n", errbuf);
        return 1;
    }

    // print information about every packet int trace
    struct pcap_pkthdr hdr;
    while ( pcap_next(pcap, &hdr) ) {
        printf("packet: ts: %u.%06u,  len: %4u,  caplen: %4u\n", hdr.ts.tv_sec, hdr.ts.tv_usec, hdr.len, hdr.caplen);
    }

    // clean up
    pcap_close(pcap);
    _pclose(tshark_out);
    return 0;
}