/*
 * Copyright (c) 2002-2004 The Regents of The University of Michigan
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * 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;
 * neither the name of the copyright holders 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.
 */

/* @file
 * Simple object for creating a simple pcap style packet trace
 */

#include <sys/time.h>

#include <algorithm>
#include <string>

#include "base/misc.hh"
#include "dev/etherdump.hh"
#include "sim/builder.hh"
#include "sim/universe.hh"

using std::string;

EtherDump::EtherDump(const string &name, const string &file, int max)
    : SimObject(name), maxlen(max)
{
    if (!file.empty())
        stream.open(file.c_str());
}

#define DLT_EN10MB		1       	// Ethernet (10Mb)
#define TCPDUMP_MAGIC		0xa1b2c3d4
#define PCAP_VERSION_MAJOR	2
#define PCAP_VERSION_MINOR	4

struct pcap_file_header {
    uint32_t magic;
    uint16_t version_major;
    uint16_t version_minor;
    int32_t thiszone;		// gmt to local correction
    uint32_t sigfigs;		// accuracy of timestamps
    uint32_t snaplen;		// max length saved portion of each pkt
    uint32_t linktype;		// data link type (DLT_*)
};

struct pcap_pkthdr {
    uint32_t seconds;
    uint32_t microseconds;
    uint32_t caplen;		// length of portion present
    uint32_t len;		// length this packet (off wire)
};

void
EtherDump::init()
{
    if (!stream.is_open())
        return;

    curtime = time(NULL);
    s_freq = ticksPerSecond;
    us_freq = ticksPerSecond / ULL(1000000);

    struct pcap_file_header hdr;
    hdr.magic = TCPDUMP_MAGIC;
    hdr.version_major = PCAP_VERSION_MAJOR;
    hdr.version_minor = PCAP_VERSION_MINOR;

    hdr.thiszone = -5 * 3600;
    hdr.snaplen = 1500;
    hdr.sigfigs = 0;
    hdr.linktype = DLT_EN10MB;

    stream.write(reinterpret_cast<char *>(&hdr), sizeof(hdr));

    /*
     * output an empty packet with the current time so that we know
     * when the simulation began.  This allows us to correlate packets
     * to sim_cycles.
     */
    pcap_pkthdr pkthdr;
    pkthdr.seconds = curtime;
    pkthdr.microseconds = 0;
    pkthdr.caplen = 0;
    pkthdr.len = 0;
    stream.write(reinterpret_cast<char *>(&pkthdr), sizeof(pkthdr));

    stream.flush();
}

void
EtherDump::dumpPacket(PacketPtr &packet)
{
    pcap_pkthdr pkthdr;
    pkthdr.seconds = curtime + (curTick / s_freq);
    pkthdr.microseconds = (curTick / us_freq) % ULL(1000000);
    pkthdr.caplen = std::min(packet->length, maxlen);
    pkthdr.len = packet->length;
    stream.write(reinterpret_cast<char *>(&pkthdr), sizeof(pkthdr));
    stream.write(reinterpret_cast<char *>(packet->data), pkthdr.caplen);
    stream.flush();
}

BEGIN_DECLARE_SIM_OBJECT_PARAMS(EtherDump)

    Param<string> file;
    Param<int> maxlen;

END_DECLARE_SIM_OBJECT_PARAMS(EtherDump)

BEGIN_INIT_SIM_OBJECT_PARAMS(EtherDump)

    INIT_PARAM(file, "file to dump packets to"),
    INIT_PARAM_DFLT(maxlen, "max portion of packet data to dump", 96)

END_INIT_SIM_OBJECT_PARAMS(EtherDump)

CREATE_SIM_OBJECT(EtherDump)
{
    string filename;
    if (file.isValid()) {
        filename = file;

        if (filename[0] != '/' && !outputDirectory.empty())
            filename = outputDirectory + filename;
    } else {
        if (outputDirectory.empty()) {
            filename = "etherdump";
        } else {
            filename = outputDirectory + "etherdump";
        }
    }

    return new EtherDump(getInstanceName(), filename, maxlen);
}

REGISTER_SIM_OBJECT("EtherDump", EtherDump)