aboutsummaryrefslogtreecommitdiffstats
path: root/lib/edi/ETIDecoder.cpp
blob: baede112eeb78ede60a087fd65241fb9fa127c06 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
/*
   Copyright (C) 2017
   Matthias P. Braendli, matthias.braendli@mpb.li

   http://opendigitalradio.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.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#include "ETIDecoder.hpp"
#include "buffer_unpack.hpp"
#include "crc.h"
#include "Log.h"
#include <stdio.h>
#include <cassert>
#include <sstream>

namespace EdiDecoder {

using namespace std;

ETIDecoder::ETIDecoder(DataCollector& data_collector) :
    m_data_collector(data_collector),
    m_last_seq(0)
{
}

void ETIDecoder::push_bytes(const vector<uint8_t> &buf)
{
    copy(buf.begin(), buf.end(), back_inserter(m_input_data));

    while (m_input_data.size() > 2) {
        if (m_input_data[0] == 'A' and m_input_data[1] == 'F') {
            const decode_state_t st = decode_afpacket(m_input_data);

            if (st.num_bytes_consumed == 0 and not st.complete) {
                // We need to refill our buffer
                break;
            }

            if (st.num_bytes_consumed) {
                vector<uint8_t> remaining_data;
                copy(m_input_data.begin() + st.num_bytes_consumed,
                        m_input_data.end(),
                        back_inserter(remaining_data));
                m_input_data = remaining_data;
            }

            if (st.complete) {
                m_data_collector.assemble();
            }

        }
        else if (m_input_data[0] == 'P' and m_input_data[1] == 'F') {
            PFT::Fragment fragment;
            const size_t fragment_bytes = fragment.loadData(m_input_data);

            if (fragment_bytes == 0) {
                // We need to refill our buffer
                break;
            }

            vector<uint8_t> remaining_data;
            copy(m_input_data.begin() + fragment_bytes,
                    m_input_data.end(),
                    back_inserter(remaining_data));
            m_input_data = remaining_data;

            if (fragment.isValid()) {
                m_pft.pushPFTFrag(fragment);
            }

            auto af = m_pft.getNextAFPacket();
            if (not af.empty()) {
                decode_state_t st = decode_afpacket(af);

                if (st.complete) {
                    m_data_collector.assemble();
                }
            }

        }
        else {
            etiLog.log(warn,"Unknown %c!", *m_input_data.data());
            m_input_data.erase(m_input_data.begin());
        }
    }
}

void ETIDecoder::push_packet(const vector<uint8_t> &buf)
{
    if (buf.size() < 2) {
        throw std::invalid_argument("Not enough bytes to read EDI packet header");
    }

    if (buf[0] == 'A' and buf[1] == 'F') {
        const decode_state_t st = decode_afpacket(buf);

        if (st.complete) {
            m_data_collector.assemble();
        }

    }
    else if (buf[0] == 'P' and buf[1] == 'F') {
        PFT::Fragment fragment;
        fragment.loadData(buf);

        if (fragment.isValid()) {
            m_pft.pushPFTFrag(fragment);
        }

        auto af = m_pft.getNextAFPacket();
        if (not af.empty()) {
            const decode_state_t st = decode_afpacket(af);

            if (st.complete) {
                m_data_collector.assemble();
            }
        }
    }
    else {
        const char packettype[3] = {(char)buf[0], (char)buf[1], '\0'};
        std::stringstream ss;
        ss << "Unknown EDI packet ";
        ss << packettype;
        throw std::invalid_argument(ss.str());
    }
}

void ETIDecoder::setMaxDelay(int num_af_packets)
{
    m_pft.setMaxDelay(num_af_packets);
}

#define AFPACKET_HEADER_LEN 10 // includes SYNC

ETIDecoder::decode_state_t ETIDecoder::decode_afpacket(
        const std::vector<uint8_t> &input_data)
{
    if (input_data.size() < AFPACKET_HEADER_LEN) {
        return {false, 0};
    }

    // read length from packet
    uint32_t taglength = read_32b(input_data.begin() + 2);
    uint16_t seq = read_16b(input_data.begin() + 6);
    if (m_last_seq + 1 != seq) {
        etiLog.level(warn) << "EDI AF Packet sequence error";
    }
    m_last_seq = seq;

    bool has_crc = (input_data[8] & 0x80) ? true : false;
    uint8_t major_revision = (input_data[8] & 0x70) >> 4;
    uint8_t minor_revision = input_data[8] & 0x0F;
    if (major_revision != 1 or minor_revision != 0) {
        throw invalid_argument("EDI AF Packet has wrong revision " +
                to_string(major_revision) + "." + to_string(minor_revision));
    }
    uint8_t pt = input_data[9];
    if (pt != 'T') {
        // only support Tag
        return {false, 0};
    }

    const size_t crclength = 2;
    if (input_data.size() < AFPACKET_HEADER_LEN + taglength + crclength) {
        return {false, 0};
    }

    if (not has_crc) {
        throw invalid_argument("AF packet not supported, has no CRC");
    }

    uint16_t crc = 0xffff;
    for (size_t i = 0; i < AFPACKET_HEADER_LEN + taglength; i++) {
        crc = crc16(crc, &input_data[i], 1);
    }
    crc ^= 0xffff;

    uint16_t packet_crc = read_16b(input_data.begin() + AFPACKET_HEADER_LEN + taglength);

    if (packet_crc != crc) {
        throw invalid_argument(
                "AF Packet crc wrong");
    }
    else {
        vector<uint8_t> payload(taglength);
        copy(input_data.begin() + AFPACKET_HEADER_LEN,
                input_data.begin() + AFPACKET_HEADER_LEN + taglength,
                payload.begin());

        return {decode_tagpacket(payload),
            AFPACKET_HEADER_LEN + taglength + 2};
    }
}

bool ETIDecoder::decode_tagpacket(const vector<uint8_t> &payload)
{
    size_t length = 0;

    bool success = true;

    for (size_t i = 0; i + 8 < payload.size(); i += 8 + length) {
        char tag_sz[5];
        tag_sz[4] = '\0';
        copy(payload.begin() + i, payload.begin() + i + 4, tag_sz);

        string tag(tag_sz);

        uint32_t taglength = read_32b(payload.begin() + i + 4);

        if (taglength % 8 != 0) {
            etiLog.log(warn, "Invalid tag length!");
            break;
        }
        taglength /= 8;

        length = taglength;

        vector<uint8_t> tag_value(taglength);
        copy(   payload.begin() + i+8,
                payload.begin() + i+8+taglength,
                tag_value.begin());

        bool tagsuccess = false;
        if (tag == "*ptr") {
            tagsuccess = decode_starptr(tag_value);
        }
        else if (tag == "deti") {
            tagsuccess = decode_deti(tag_value);
        }
        else if (tag.substr(0, 3) == "est") {
            uint8_t n = tag_sz[3];
            tagsuccess = decode_estn(tag_value, n);
        }
        else if (tag == "*dmy") {
            tagsuccess = decode_stardmy(tag_value);
        }
        else {
            etiLog.log(warn, "Unknown TAG %s", tag.c_str());
            break;
        }

        if (not tagsuccess) {
            etiLog.log(warn, "Error decoding TAG %s", tag.c_str());
            success = tagsuccess;
            break;
        }
    }

    return success;
}

bool ETIDecoder::decode_starptr(const vector<uint8_t> &value)
{
    if (value.size() != 0x40 / 8) {
        etiLog.log(warn, "Incorrect length %02lx for *PTR", value.size());
        return false;
    }

    char protocol_sz[5];
    protocol_sz[4] = '\0';
    copy(value.begin(), value.begin() + 4, protocol_sz);
    string protocol(protocol_sz);

    uint16_t major = read_16b(value.begin() + 4);
    uint16_t minor = read_16b(value.begin() + 6);

    m_data_collector.update_protocol(protocol, major, minor);

    return true;
}

bool ETIDecoder::decode_deti(const vector<uint8_t> &value)
{
    /*
    uint16_t detiHeader = fct | (fcth << 8) | (rfudf << 13) | (ficf << 14) | (atstf << 15);
    packet.push_back(detiHeader >> 8);
    packet.push_back(detiHeader & 0xFF);
    */

    uint16_t detiHeader = read_16b(value.begin());

    eti_fc_data fc;

    fc.atstf = (detiHeader >> 15) & 0x1;
    fc.ficf = (detiHeader >> 14) & 0x1;
    bool rfudf = (detiHeader >> 13) & 0x1;
    uint8_t fcth = (detiHeader >> 8) & 0x1F;
    uint8_t fct = detiHeader & 0xFF;

    fc.dflc = fcth * 250 + fct; // modulo 5000 counter

    uint32_t etiHeader = read_32b(value.begin() + 2);

    uint8_t stat = (etiHeader >> 24) & 0xFF;

    fc.mid = (etiHeader >> 22) & 0x03;
    fc.fp = (etiHeader >> 19) & 0x07;
    uint8_t rfa = (etiHeader >> 17) & 0x3;
    if (rfa != 0) {
        etiLog.log(warn, "EDI deti TAG: rfa non-zero");
    }

    bool rfu = (etiHeader >> 16) & 0x1;
    uint16_t mnsc = rfu ? 0xFFFF : etiHeader & 0xFFFF;

    const size_t fic_length_words = (fc.ficf ? (fc.mid == 3 ? 32 : 24) : 0);
    const size_t fic_length = 4 * fic_length_words;

    const size_t expected_length = 2 + 4 +
        (fc.atstf ? 1 + 4 + 3 : 0) +
        fic_length +
        (rfudf ? 3 : 0);

    if (value.size() != expected_length) {
        throw std::logic_error("EDI deti: Assertion error:"
                "value.size() != expected_length: " +
               to_string(value.size()) + " " +
               to_string(expected_length));
    }

    etiLog.level(debug) << "EDI DETI";
    m_data_collector.update_err(stat);
    m_data_collector.update_mnsc(mnsc);

    size_t i = 2 + 4;

    if (fc.atstf) {
        uint8_t utco = value[i];
        i++;

        uint32_t seconds = read_32b(value.begin() + i);
        i += 4;

        m_data_collector.update_edi_time(utco, seconds);

        fc.tsta = read_24b(value.begin() + i);
        i += 3;
    }
    else {
        // Null timestamp, ETSI ETS 300 799, C.2.2
        fc.tsta = 0xFFFFFF;
    }


    if (fc.ficf) {
        vector<uint8_t> fic(fic_length);
        copy(   value.begin() + i,
                value.begin() + i + fic_length,
                fic.begin());
        i += fic_length;

        m_data_collector.update_fic(fic);
    }

    if (rfudf) {
        uint32_t rfud = read_24b(value.begin() + i);

        // high 16 bits: RFU in LIDATA EOH
        // low 8 bits: RFU in TIST (not supported)
        m_data_collector.update_rfu(rfud >> 8);
        if ((rfud & 0xFF) != 0xFF) {
            etiLog.level(warn) << "EDI: RFU in TIST not supported";
        }

        i += 3;
    }

    m_data_collector.update_fc_data(fc);

    return true;
}

bool ETIDecoder::decode_estn(const vector<uint8_t> &value, uint8_t n)
{
    uint32_t sstc = read_24b(value.begin());

    eti_stc_data stc;

    stc.stream_index = n - 1; // n is 1-indexed
    stc.scid = (sstc >> 18) & 0x3F;
    stc.sad = (sstc >> 8) & 0x3FF;
    stc.tpl = (sstc >> 2) & 0x3F;
    uint8_t rfa = sstc & 0x3;
    if (rfa != 0) {
        etiLog.level(warn) << "EDI: rfa field in ESTn tag non-null";
    }

    copy(   value.begin() + 3,
            value.end(),
            back_inserter(stc.mst));

    etiLog.level(debug) << "EDI ESTn " << (int)stc.stream_index;
    m_data_collector.add_subchannel(stc);

    return true;
}

bool ETIDecoder::decode_stardmy(const vector<uint8_t> &value)
{
    return true;
}

}