/* 
 * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
 * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
 */
#include <pjlib.h>
#include <pjlib-util.h>
#include <pjmedia.h>
#include <pjmedia-codec.h>

static const char *USAGE =
"pcaputil [options] INPUT OUTPUT\n"
"\n"
"  Convert captured RTP packets in PCAP file to WAV file or play it\n"
"  to audio device.\n"
"\n"
"  INPUT  is the PCAP file name/path.\n"
"  OUTPUT is the WAV file name/path to store the output, or set to \"-\",\n"
"         to play the output to audio device. The program will decode\n"
"         the RTP contents using codec that is available in PJMEDIA,\n"
"         and optionally decrypt the content using the SRTP crypto and\n"
"         keys below.\n"
"\n"
"Options to filter packets from PCAP file:\n"
"(you can always select the relevant packets from Wireshark of course!)\n"
"  --src-ip=IP            Only include packets from this source address\n"
"  --dst-ip=IP            Only include packets destined to this address\n"
"  --src-port=port        Only include packets from this source port number\n"
"  --dst-port=port        Only include packets destined to this port number\n"
"\n"
"Options for RTP packet processing:\n"
""
"  --codec=codec_id       The codec ID formatted \"name/clock-rate/channel-count\"\n"
"                         must be specified for codec with dynamic PT,\n"
"                         e.g: \"Speex/8000\"\n"
"  --srtp-crypto=TAG, -c  Set crypto to be used to decrypt SRTP packets. Valid\n"
"                         tags are: \n"
"                           AES_CM_128_HMAC_SHA1_80 \n"
"                           AES_CM_128_HMAC_SHA1_32\n"
"  --srtp-key=KEY, -k     Set the base64 key to decrypt SRTP packets.\n"
"\n"
"Options for playing to audio device:\n"
""
"  --play-dev-id=dev_id   Audio device ID for playback.\n"
"\n"
"  Example:\n"
"    pcaputil file.pcap output.wav\n"
"    pcaputil -c AES_CM_128_HMAC_SHA1_80 \\\n"
"             -k VLDONbsbGl2Puqy+0PV7w/uGfpSPKFevDpxGsxN3 \\\n"
"             file.pcap output.wav\n"
"\n"
;

static struct app
{
    pj_caching_pool      cp;
    pj_pool_t           *pool;
    pjmedia_endpt       *mept;
    pj_pcap_file        *pcap;
    pjmedia_port        *wav;
    pjmedia_codec       *codec;
    pjmedia_aud_stream  *aud_strm;
    unsigned             pt;
    pjmedia_transport   *srtp;
    pjmedia_rtp_session  rtp_sess;
    pj_bool_t            rtp_sess_init;
} app;


static void cleanup()
{
    if (app.srtp) pjmedia_transport_close(app.srtp);
    if (app.wav) {
        pj_ssize_t pos = pjmedia_wav_writer_port_get_pos(app.wav);
        if (pos >= 0) {
            unsigned msec;
            msec = (unsigned)pos / 2 * 1000 / PJMEDIA_PIA_SRATE(&app.wav->info);
            printf("Written: %dm:%02ds.%03d\n",
                    msec / 1000 / 60,
                    (msec / 1000) % 60,
                    msec % 1000);
        }
        pjmedia_port_destroy(app.wav);
    }
    if (app.pcap) pj_pcap_close(app.pcap);
    if (app.codec) {
        pjmedia_codec_mgr *cmgr;
        pjmedia_codec_close(app.codec);
        cmgr = pjmedia_endpt_get_codec_mgr(app.mept);
        pjmedia_codec_mgr_dealloc_codec(cmgr, app.codec);
    }
    if (app.aud_strm) {
        pjmedia_aud_stream_stop(app.aud_strm);
        pjmedia_aud_stream_destroy(app.aud_strm);
    }
    if (app.mept) pjmedia_endpt_destroy(app.mept);
    if (app.pool) pj_pool_release(app.pool);
    pj_caching_pool_destroy(&app.cp);
    pj_shutdown();
}

static void err_exit(const char *title, pj_status_t status)
{
    if (status != PJ_SUCCESS) {
        char errmsg[PJ_ERR_MSG_SIZE];
        pj_strerror(status, errmsg, sizeof(errmsg));
        printf("Error: %s: %s\n", title, errmsg);
    } else {
        printf("Error: %s\n", title);
    }
    cleanup();
    exit(1);
}

#define T(op)       do { \
                        status = op; \
                        if (status != PJ_SUCCESS) \
                            err_exit(#op, status); \
                    } while (0)


static void read_rtp(pj_uint8_t *buf, pj_size_t bufsize,
                     pjmedia_rtp_hdr **rtp,
                     pj_uint8_t **payload,
                     unsigned *payload_size,
                     pj_bool_t check_pt)
{
    pj_status_t status;

    /* Init RTP session */
    if (!app.rtp_sess_init) {
        T(pjmedia_rtp_session_init(&app.rtp_sess, 0, 0));
        app.rtp_sess_init = PJ_TRUE;
    }

    /* Loop reading until we have a good RTP packet */
    for (;;) {
        pj_size_t sz = bufsize;
        const pjmedia_rtp_hdr *r;
        const void *p;
        pjmedia_rtp_status seq_st;

        status = pj_pcap_read_udp(app.pcap, NULL, buf, &sz);
        if (status != PJ_SUCCESS)
            err_exit("Error reading PCAP file", status);

        /* Decode RTP packet to make sure that this is an RTP packet.
         * We will decode it again to get the payload after we do
         * SRTP decoding
         */
        status = pjmedia_rtp_decode_rtp(&app.rtp_sess, buf, (int)sz, &r, 
                                        &p, payload_size);
        if (status != PJ_SUCCESS) {
            char errmsg[PJ_ERR_MSG_SIZE];
            pj_strerror(status, errmsg, sizeof(errmsg));
            printf("Not RTP packet, skipping packet: %s\n", errmsg);
            continue;
        }

        /* Decrypt SRTP */
#if PJMEDIA_HAS_SRTP
        if (app.srtp) {
            int len = (int)sz;
            status = pjmedia_transport_srtp_decrypt_pkt(app.srtp, PJ_TRUE, 
                                                        buf, &len);
            if (status != PJ_SUCCESS) {
                char errmsg[PJ_ERR_MSG_SIZE];
                pj_strerror(status, errmsg, sizeof(errmsg));
                printf("SRTP packet decryption failed, skipping packet: %s\n", 
                        errmsg);
                continue;
            }
            sz = len;

            /* Decode RTP packet again */
            status = pjmedia_rtp_decode_rtp(&app.rtp_sess, buf, (int)sz, &r,
                                            &p, payload_size);
            if (status != PJ_SUCCESS) {
                char errmsg[PJ_ERR_MSG_SIZE];
                pj_strerror(status, errmsg, sizeof(errmsg));
                printf("Not RTP packet, skipping packet: %s\n", errmsg);
                continue;
            }
        }
#endif

        /* Update RTP session */
        pjmedia_rtp_session_update2(&app.rtp_sess, r, &seq_st, PJ_FALSE);

        /* Skip out-of-order packet */
        if (seq_st.diff == 0) {
            printf("Skipping out of order packet\n");
            continue;
        }

        /* Skip if payload type is different */
        if (check_pt && r->pt != app.pt) {
            printf("Skipping RTP packet with bad payload type\n");
            continue;
        }

        /* Skip bad packet */
        if (seq_st.status.flag.bad) {
            printf("Skipping bad RTP\n");
            continue;
        }


        *rtp = (pjmedia_rtp_hdr*)r;
        *payload = (pj_uint8_t*)p;

        /* We have good packet */
        break;
    }
}

pjmedia_frame play_frm;
static pj_bool_t play_frm_copied, play_frm_ready;

static pj_status_t wait_play(pjmedia_frame *f)
{
    play_frm_copied = PJ_FALSE;
    play_frm = *f;
    play_frm_ready = PJ_TRUE;
    while (!play_frm_copied) {
        pj_thread_sleep(1);
    }
    play_frm_ready = PJ_FALSE;

    return PJ_SUCCESS;
}

static pj_status_t play_cb(void *user_data, pjmedia_frame *f)
{
    PJ_UNUSED_ARG(user_data);

    if (!play_frm_ready) {
        PJ_LOG(3, ("play_cb()", "Warning! Play frame not ready")); 
        return PJ_SUCCESS;
    }

    pj_memcpy(f->buf, play_frm.buf, play_frm.size);
    f->size = play_frm.size;

    play_frm_copied = PJ_TRUE;
    return PJ_SUCCESS;
}

static void pcap2wav(const pj_str_t *codec,
                     const pj_str_t *wav_filename,
                     pjmedia_aud_dev_index dev_id,
                     const pj_str_t *srtp_crypto,
                     const pj_str_t *srtp_key)
{
    const pj_str_t WAV = {".wav", 4};
    struct pkt
    {
        pj_uint8_t       buffer[PJMEDIA_MAX_MTU];
        pjmedia_rtp_hdr *rtp;
        pj_uint8_t      *payload;
        unsigned         payload_len;
    } pkt0;
    pjmedia_codec_mgr *cmgr;
    const pjmedia_codec_info *ci;
    pjmedia_codec_param param;
    unsigned samples_per_frame;
    pj_status_t status;

    /* Initialize all codecs */
    T( pjmedia_codec_register_audio_codecs(app.mept, NULL) );

    /* Create SRTP transport is needed */
#if PJMEDIA_HAS_SRTP
    if (srtp_crypto->slen) {
        pjmedia_srtp_crypto crypto;
        pjmedia_transport *tp;

        pj_bzero(&crypto, sizeof(crypto));
        crypto.key = *srtp_key;
        crypto.name = *srtp_crypto;
        T( pjmedia_transport_loop_create(app.mept, &tp) );
        T( pjmedia_transport_srtp_create(app.mept, tp, NULL, &app.srtp) );
        T( pjmedia_transport_srtp_start(app.srtp, &crypto, &crypto) );
    }
#else
    PJ_UNUSED_ARG(srtp_crypto);
    PJ_UNUSED_ARG(srtp_key);
#endif

    /* Read first packet */
    read_rtp(pkt0.buffer, sizeof(pkt0.buffer), &pkt0.rtp, 
             &pkt0.payload, &pkt0.payload_len, PJ_FALSE);

    cmgr = pjmedia_endpt_get_codec_mgr(app.mept);

    /* Get codec info and param for the specified payload type */
    app.pt = pkt0.rtp->pt;
    if (app.pt < 96) {
        T( pjmedia_codec_mgr_get_codec_info(cmgr, pkt0.rtp->pt, &ci) );
    } else {
        unsigned cnt = 2;
        const pjmedia_codec_info *info[2];
        T( pjmedia_codec_mgr_find_codecs_by_id(cmgr, codec, &cnt, 
                                               info, NULL) );
        if (cnt != 1)
            err_exit("Codec ID must be specified and unique!", 0);

        ci = info[0];
    }
    T( pjmedia_codec_mgr_get_default_param(cmgr, ci, &param) );

    /* Alloc and init codec */
    T( pjmedia_codec_mgr_alloc_codec(cmgr, ci, &app.codec) );
    T( pjmedia_codec_init(app.codec, app.pool) );
    T( pjmedia_codec_open(app.codec, &param) );

    /* Init audio device or WAV file */
    samples_per_frame = ci->clock_rate * param.info.frm_ptime / 1000;
    if (pj_strcmp2(wav_filename, "-") == 0) {
        pjmedia_aud_param aud_param;

        /* Open audio device */
        T( pjmedia_aud_dev_default_param(dev_id, &aud_param) );
        aud_param.dir = PJMEDIA_DIR_PLAYBACK;
        aud_param.channel_count = ci->channel_cnt;
        aud_param.clock_rate = ci->clock_rate;
        aud_param.samples_per_frame = samples_per_frame;
        T( pjmedia_aud_stream_create(&aud_param, NULL, &play_cb, 
                                     NULL, &app.aud_strm) );
        T( pjmedia_aud_stream_start(app.aud_strm) );
    } else if (pj_stristr(wav_filename, &WAV)) {
        /* Open WAV file */
        T( pjmedia_wav_writer_port_create(app.pool, wav_filename->ptr,
                                          ci->clock_rate, ci->channel_cnt,
                                          samples_per_frame,
                                          param.info.pcm_bits_per_sample, 0, 0,
                                          &app.wav) );
    } else {
        err_exit("invalid output file", PJ_EINVAL);
    }

    /* Loop reading PCAP and writing WAV file */
    for (;;) {
        struct pkt pkt1;
        pj_timestamp ts;
        pjmedia_frame frames[16], pcm_frame;
        short pcm[PJMEDIA_MAX_MTU];
        unsigned i, frame_cnt;
        long samples_cnt, ts_gap;

        pj_assert(sizeof(pcm) >= samples_per_frame);

        /* Parse first packet */
        ts.u64 = 0;
        frame_cnt = PJ_ARRAY_SIZE(frames);
        T( pjmedia_codec_parse(app.codec, pkt0.payload, pkt0.payload_len, 
                                &ts, &frame_cnt, frames) );

        /* Decode and write to WAV file */
        samples_cnt = 0;
        for (i=0; i<frame_cnt; ++i) {
            pcm_frame.buf = pcm;
            pcm_frame.size = samples_per_frame * 2;

            T( pjmedia_codec_decode(app.codec, &frames[i], 
                                    (unsigned)pcm_frame.size, &pcm_frame) );
            if (app.wav) {
                T( pjmedia_port_put_frame(app.wav, &pcm_frame) );
            }
            if (app.aud_strm) {
                T( wait_play(&pcm_frame) );
            }
            samples_cnt += samples_per_frame;
        }

        /* Read next packet */
        read_rtp(pkt1.buffer, sizeof(pkt1.buffer), &pkt1.rtp,
                 &pkt1.payload, &pkt1.payload_len, PJ_TRUE);

        /* Fill in the gap (if any) between pkt0 and pkt1 */
        ts_gap = pj_ntohl(pkt1.rtp->ts) - pj_ntohl(pkt0.rtp->ts) -
                 samples_cnt;
        while (ts_gap >= (long)samples_per_frame) {

            pcm_frame.buf = pcm;
            pcm_frame.size = samples_per_frame * 2;

            if (app.codec->op->recover) {
                T( pjmedia_codec_recover(app.codec, (unsigned)pcm_frame.size, 
                                         &pcm_frame) );
            } else {
                pj_bzero(pcm_frame.buf, pcm_frame.size);
            }

            if (app.wav) {
                T( pjmedia_port_put_frame(app.wav, &pcm_frame) );
            }
            if (app.aud_strm) {
                T( wait_play(&pcm_frame) );
            }
            ts_gap -= samples_per_frame;
        }
        
        /* Next */
        pkt0 = pkt1;
        pkt0.rtp = (pjmedia_rtp_hdr*)pkt0.buffer;
        pkt0.payload = pkt0.buffer + (pkt1.payload - pkt1.buffer);
    }
}


int main(int argc, char *argv[])
{
    pj_str_t input, output, srtp_crypto, srtp_key, codec;
    pjmedia_aud_dev_index dev_id = PJMEDIA_AUD_DEFAULT_PLAYBACK_DEV;
    pj_pcap_filter filter;
    pj_status_t status;

    enum { 
        OPT_SRC_IP = 1, OPT_DST_IP, OPT_SRC_PORT, OPT_DST_PORT,
        OPT_CODEC, OPT_PLAY_DEV_ID
    };
    struct pj_getopt_option long_options[] = {
        { "srtp-crypto",    1, 0, 'c' },
        { "srtp-key",       1, 0, 'k' },
        { "src-ip",         1, 0, OPT_SRC_IP },
        { "dst-ip",         1, 0, OPT_DST_IP },
        { "src-port",       1, 0, OPT_SRC_PORT },
        { "dst-port",       1, 0, OPT_DST_PORT },
        { "codec",          1, 0, OPT_CODEC },
        { "play-dev-id",    1, 0, OPT_PLAY_DEV_ID },
        { NULL, 0, 0, 0}
    };
    int c;
    int option_index;
    char key_bin[32];

    srtp_crypto.slen = srtp_key.slen = 0;
    codec.slen = 0;

    pj_pcap_filter_default(&filter);
    filter.link = PJ_PCAP_LINK_TYPE_ETH;
    filter.proto = PJ_PCAP_PROTO_TYPE_UDP;

    /* Parse arguments */
    pj_optind = 0;
    while((c=pj_getopt_long(argc,argv, "c:k:", long_options, &option_index))!=-1) {
        switch (c) {
        case 'c':
            srtp_crypto = pj_str(pj_optarg);
            break;
        case 'k':
            {
                int key_len = sizeof(key_bin);
                srtp_key = pj_str(pj_optarg);
                if (pj_base64_decode(&srtp_key, (pj_uint8_t*)key_bin, &key_len)) {
                    puts("Error: invalid key");
                    return 1;
                }
                srtp_key.ptr = key_bin;
                srtp_key.slen = key_len;
            }
            break;
        case OPT_SRC_IP:
            {
                pj_str_t t = pj_str(pj_optarg);
                pj_in_addr a = pj_inet_addr(&t);
                filter.ip_src = a.s_addr;
            }
            break;
        case OPT_DST_IP:
            {
                pj_str_t t = pj_str(pj_optarg);
                pj_in_addr a = pj_inet_addr(&t);
                filter.ip_dst = a.s_addr;
            }
            break;
        case OPT_SRC_PORT:
            filter.src_port = pj_htons((pj_uint16_t)atoi(pj_optarg));
            break;
        case OPT_DST_PORT:
            filter.dst_port = pj_htons((pj_uint16_t)atoi(pj_optarg));
            break;
        case OPT_CODEC:
            codec = pj_str(pj_optarg);
            break;
        case OPT_PLAY_DEV_ID:
            dev_id = atoi(pj_optarg);
            break;
        default:
            puts("Error: invalid option");
            return 1;
        }
    }

    if (pj_optind != argc - 2) {
        puts(USAGE);
        return 1;
    }

    if (!(srtp_crypto.slen) != !(srtp_key.slen)) {
        puts("Error: both SRTP crypto and key must be specified");
        puts(USAGE);
        return 1;
    }

    input = pj_str(argv[pj_optind]);
    output = pj_str(argv[pj_optind+1]);
    
    T( pj_init() );

    pj_caching_pool_init(&app.cp, NULL, 0);
    app.pool = pj_pool_create(&app.cp.factory, "pcaputil", 1000, 1000, NULL);

    T( pjlib_util_init() );
    T( pjmedia_endpt_create(&app.cp.factory, NULL, 0, &app.mept) );

    T( pj_pcap_open(app.pool, input.ptr, &app.pcap) );
    T( pj_pcap_set_filter(app.pcap, &filter) );

    pcap2wav(&codec, &output, dev_id, &srtp_crypto, &srtp_key);

    cleanup();
    return 0;
}

