/* $Id$ */

/*
 *   Copyright (c) 2001-2010 Aaron Turner <aturner at synfin dot net>
 *   Copyright (c) 2013-2018 Fred Klassen <tcpreplay at appneta dot com> - AppNeta
 *
 *   The Tcpreplay Suite of tools is free software: you can redistribute it 
 *   and/or modify it under the terms of the GNU General Public License as 
 *   published by the Free Software Foundation, either version 3 of the 
 *   License, or with the authors permission any later version.
 *
 *   The Tcpreplay Suite is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with the Tcpreplay Suite.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <unistd.h>
#include <string.h>

#include "config.h"
#include "defines.h"
#include "common.h"
#include "tcpreplay_api.h"
#include "send_packets.h"


static int replay_file(tcpreplay_t *ctx, int idx);
static int replay_two_files(tcpreplay_t *ctx, int idx1, int idx2);
static int replay_cache(tcpreplay_t *ctx, int idx);
static int replay_two_caches(tcpreplay_t *ctx, int idx1, int idx2);
static int replay_fd(tcpreplay_t *ctx, int idx);
static int replay_two_fds(tcpreplay_t *ctx, int idx1, int idx2);

/**
 * \brief Internal tcpreplay method to replay a given index
 *
 * This is used by tcpreplay_replay() to actually send the packets
 */
int 
tcpr_replay_index(tcpreplay_t *ctx)
{
    int rcode = 0;
    int idx;
    assert(ctx);

    /* only process a single file */
    if (! ctx->options->dualfile) {
        /* process each pcap file in order */
        for (idx = 0; idx < ctx->options->source_cnt && !ctx->abort; idx++) {
            /* reset cache markers for each iteration */
            ctx->cache_byte = 0;
            ctx->cache_bit = 0;
            switch(ctx->options->sources[idx].type) {
                case source_filename:
                    rcode = replay_file(ctx, idx);
                    break;
                case source_fd:
                    rcode = replay_fd(ctx, idx);
                    break;
                case source_cache:
                    rcode = replay_cache(ctx, idx);
                    break;
                default:
                    tcpreplay_seterr(ctx, "Invalid source type: %d", ctx->options->sources[idx].type);
                    rcode = -1;
            }
        }
    }

    /* dual file mode: two files, two interfaces */
    else {
        /* process each pcap file in order */
        for (idx = 0; idx < ctx->options->source_cnt && !ctx->abort; idx += 2) {
            if (ctx->options->sources[idx].type != ctx->options->sources[(idx+1)].type) {
                tcpreplay_seterr(ctx, "Both source indexes (%d, %d) must be of the same type", idx, (idx+1));
                return -1;
            }
            switch(ctx->options->sources[idx].type) {
                case source_filename:
                    rcode = replay_two_files(ctx, idx, (idx+1));
                    break;
                case source_fd:
                    rcode = replay_two_fds(ctx, idx, (idx+1));
                    break;
                case source_cache:
                    rcode = replay_two_caches(ctx, idx, (idx+1));
                    break;
                default:
                    tcpreplay_seterr(ctx, "Invalid source type: %d", ctx->options->sources[idx].type);
                    rcode = -1;
            }

        }

    }
    if (rcode < 0) {
        ctx->running = false;
        return -1;
    }

    return rcode;
}


/**
 * \brief replay a pcap file out interface(s)
 *
 * Internal to tcpreplay.  Does the heavy lifting.
 */
static int
replay_file(tcpreplay_t *ctx, int idx)
{
    char *path;
    pcap_t *pcap = NULL;
    char ebuf[PCAP_ERRBUF_SIZE];

    assert(ctx);
    assert(ctx->options->sources[idx].type == source_filename);

    path = ctx->options->sources[idx].filename;

    /* read from pcap file if we haven't cached things yet */
    if (!ctx->options->preload_pcap) {
        if ((pcap = pcap_open_offline(path, ebuf)) == NULL) {
            tcpreplay_seterr(ctx, "Error opening pcap file: %s", ebuf);
            return -1;
        }

        ctx->options->file_cache[idx].dlt = pcap_datalink(pcap);

#ifdef HAVE_PCAP_SNAPSHOT
        if (pcap_snapshot(pcap) < 65535)
            warnx("%s was captured using a snaplen of %d bytes.  This may mean you have truncated packets.",
                    path, pcap_snapshot(pcap));
#endif

    } else {
        if (!ctx->options->file_cache[idx].cached) {
            if ((pcap = pcap_open_offline(path, ebuf)) == NULL) {
                tcpreplay_seterr(ctx, "Error opening pcap file: %s", ebuf);
                return -1;
            }
            ctx->options->file_cache[idx].dlt = pcap_datalink(pcap);
        }
    }

#ifdef ENABLE_VERBOSE
    if (ctx->options->verbose) {
        /* in cache mode, we may not have opened the file */
        if (pcap == NULL)
            if ((pcap = pcap_open_offline(path, ebuf)) == NULL) {
               tcpreplay_seterr(ctx, "Error opening pcap file: %s", ebuf);
               return -1;
            }

        ctx->options->file_cache[idx].dlt = pcap_datalink(pcap);
        /* init tcpdump */
        tcpdump_open(ctx->options->tcpdump, pcap);
    }
#endif

    if (pcap != NULL) {
        if (ctx->intf1dlt == -1)
            ctx->intf1dlt = sendpacket_get_dlt(ctx->intf1);
#if 0
        if ((ctx->intf1dlt >= 0) && (ctx->intf1dlt != pcap_datalink(pcap)))
            warnx("%s DLT (%s) does not match that of the outbound interface: %s (%s)",
                    path, pcap_datalink_val_to_name(pcap_datalink(pcap)),
                    ctx->options->intf1->device, pcap_datalink_val_to_name(ctx->intf1dlt));
#endif
        if (ctx->intf1dlt != ctx->options->file_cache[idx].dlt)
            tcpreplay_setwarn(ctx, "%s DLT (%s) does not match that of the outbound interface: %s (%s)",
                path, pcap_datalink_val_to_name(pcap_datalink(pcap)),
                ctx->intf1->device, pcap_datalink_val_to_name(ctx->intf1dlt));
    }

    ctx->stats.active_pcap = ctx->options->sources[idx].filename;
    send_packets(ctx, pcap, idx);

    if (pcap != NULL)
        pcap_close(pcap);

#ifdef ENABLE_VERBOSE
    tcpdump_close(ctx->options->tcpdump);
#endif
    return 0;
}


/**
 * \brief replay two pcap files out two interfaces
 *
 * Internal to tcpreplay, does the heavy lifting for --dualfile
 */
static int
replay_two_files(tcpreplay_t *ctx, int idx1, int idx2)
{
    char *path1, *path2;
    pcap_t *pcap1  = NULL, *pcap2 = NULL;
    char ebuf[PCAP_ERRBUF_SIZE];
    int rcode = 0;

    assert(ctx);
    assert(ctx->options->sources[idx1].type == source_filename);
    assert(ctx->options->sources[idx2].type == source_filename);

    path1 = ctx->options->sources[idx1].filename;
    path2 = ctx->options->sources[idx2].filename;


    /* can't use stdin in dualfile mode */
    if ((strncmp(path1, "-", strlen(path1)) == 0) || 
        (strncmp(path2, "-", strlen(path2)) == 0)) {
        tcpreplay_seterr(ctx, "%s", "Invalid use of STDIN '-' in dual file mode");
        return -1;
    }

    /* read from first pcap file if we haven't cached things yet */
    if (!ctx->options->preload_pcap) {
        if ((pcap1 = pcap_open_offline(path1, ebuf)) == NULL) {
            tcpreplay_seterr(ctx, "Error opening pcap file: %s", ebuf);
            return -1;
        }
        ctx->options->file_cache[idx1].dlt = pcap_datalink(pcap1);
        if ((pcap2 = pcap_open_offline(path2, ebuf)) == NULL) {
            tcpreplay_seterr(ctx, "Error opening pcap file: %s", ebuf);
            return -1;
        }
        ctx->options->file_cache[idx2].dlt = pcap_datalink(pcap2);
    } else {
        if (!ctx->options->file_cache[idx1].cached) {
            if ((pcap1 = pcap_open_offline(path1, ebuf)) == NULL) {
                tcpreplay_seterr(ctx, "Error opening pcap file: %s", ebuf);
                return -1;
            }
            ctx->options->file_cache[idx1].dlt = pcap_datalink(pcap1);
        }
        if (!ctx->options->file_cache[idx2].cached) {
            if ((pcap2 = pcap_open_offline(path2, ebuf)) == NULL) {
                tcpreplay_seterr(ctx, "Error opening pcap file: %s", ebuf);
                return -1;
            }
            ctx->options->file_cache[idx2].dlt = pcap_datalink(pcap2);
        }
    }

    if (pcap1 != NULL) {
#ifdef HAVE_PCAP_SNAPSHOT
        if (pcap_snapshot(pcap1) < 65535) {
            tcpreplay_setwarn(ctx, "%s was captured using a snaplen of %d bytes.  This may mean you have truncated packets.",
                    path1, pcap_snapshot(pcap1));
            rcode = -2;
        }

        if (pcap_snapshot(pcap2) < 65535) {
            tcpreplay_setwarn(ctx, "%s was captured using a snaplen of %d bytes.  This may mean you have truncated packets.",
                    path2, pcap_snapshot(pcap2));
            rcode = -2;
        }
#endif
        if (ctx->intf1dlt == -1)
            ctx->intf1dlt = sendpacket_get_dlt(ctx->intf1);
        if ((ctx->intf1dlt >= 0) && (ctx->intf1dlt != pcap_datalink(pcap1))) {
            tcpreplay_setwarn(ctx, "%s DLT (%s) does not match that of the outbound interface: %s (%s)", 
                path1, pcap_datalink_val_to_name(pcap_datalink(pcap1)), 
                ctx->intf1->device, pcap_datalink_val_to_name(ctx->intf1dlt));
            rcode = -2;
        }

        if (ctx->intf2dlt == -1)
            ctx->intf2dlt = sendpacket_get_dlt(ctx->intf2);
        if ((ctx->intf2dlt >= 0) && (ctx->intf2dlt != pcap_datalink(pcap2))) {
            tcpreplay_setwarn(ctx, "%s DLT (%s) does not match that of the outbound interface: %s (%s)", 
                path2, pcap_datalink_val_to_name(pcap_datalink(pcap2)), 
                ctx->intf2->device, pcap_datalink_val_to_name(ctx->intf2dlt));
            rcode = -2;
        }

        if (ctx->intf1dlt != ctx->intf2dlt) {
            tcpreplay_seterr(ctx, "DLT mismatch for %s (%d) and %s (%d)",
                    path1, ctx->intf1dlt, path2, ctx->intf2dlt);
            return -1;
        }
    }

#ifdef ENABLE_VERBOSE
    if (ctx->options->verbose) {

        /* in cache mode, we may not have opened the file */
        if (pcap1 == NULL) {
            if ((pcap1 = pcap_open_offline(path1, ebuf)) == NULL) {
                tcpreplay_seterr(ctx, "Error opening pcap file: %s", ebuf);
                return -1;
            }
            ctx->options->file_cache[idx1].dlt = pcap_datalink(pcap1);
        }
        /* init tcpdump */
        tcpdump_open(ctx->options->tcpdump, pcap1);
    }
#endif


    send_dual_packets(ctx, pcap1, idx1, pcap2, idx2);

    if (pcap1 != NULL)
        pcap_close(pcap1);

    if (pcap2 != NULL)
        pcap_close(pcap2);

#ifdef ENABLE_VERBOSE
    tcpdump_close(ctx->options->tcpdump);
#endif

    return rcode;
}


/**
 * \brief Replay index using existing memory cache 
 *
 * FIXME
 */
static int
replay_cache(tcpreplay_t *ctx, int idx)
{

    assert(ctx);
    assert(ctx->options->sources[idx].type == source_cache);
    return 0;
}

/**
 * \brief Replay two indexes using existing memory cache 
 *
 * FIXME
 */
static int
replay_two_caches(tcpreplay_t *ctx, int idx1, int idx2)
{

    assert(ctx);
    assert(ctx->options->sources[idx1].type == source_cache);
    assert(ctx->options->sources[idx2].type == source_cache);
    return 0;
}

/**
 * \brief Replay index which is a file descriptor 
 *
 * FIXME
 */
static int
replay_fd(tcpreplay_t *ctx, int idx)
{

    assert(ctx);
    assert(ctx->options->sources[idx].type == source_fd);
    return 0;
}

/**
 * \brief Replay two indexes which are a file descriptor 
 *
 * FIXME
 */
static int
replay_two_fds(tcpreplay_t *ctx, int idx1, int idx2)
{

    assert(ctx);
    assert(ctx->options->sources[idx1].type == source_fd);
    assert(ctx->options->sources[idx2].type == source_fd);
    return 0;
}