Coverage Report

Created: 2026-02-26 06:35

next uncovered line (L), next uncovered region (R), next uncovered branch (B)
/src/gpsd/gpsd-3.27.6~dev/drivers/driver_ais.c
Line
Count
Source
1
/*
2
 * Driver for AIS messages.
3
 *
4
 * See the file AIVDM.txt on the GPSD website for documentation and references.
5
 * AIVDM de-armoring is handled elsewhere; this is the binary-packet driver.
6
 *
7
 * Code for message types 1-15, 18-21, and 24 has been tested against
8
 * live data with known-good decodings. Code for message types 16-17,
9
 * 22-23, and 25-27 has not.
10
 * For the special IMO messages (types 6 and 8), only the following have been
11
 * tested against known-good decodings:
12
 *  - IMO236 met/hydro message: Type=8, DAC=1, FI=11
13
 *  - IMO289 met/hydro message: Type=8, DAC=1, FI=31
14
 *
15
 * This file is Copyright 2010 by the GPSD project
16
 * SPDX-License-Identifier: BSD-2-clause
17
 */
18
19
#include "../include/gpsd_config.h"   // must be before all includes
20
21
#include <ctype.h>
22
#include <stdlib.h>
23
#include <string.h>
24
25
#include "../include/gpsd.h"
26
#include "../include/bits.h"
27
28
/*
29
 * Parse the data from the device
30
 */
31
32
// beginning at bitvec bit start, unpack count sixbit characters
33
static void from_sixbit_untrimmed(const unsigned char *bitvec,
34
                                  unsigned int start,
35
                                  int count, char *to)
36
0
{
37
0
    const char sixchr[65] =
38
0
        "@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_ !\"#$%&'()*+,-./0123456789:;<=>?";
39
0
    int i;
40
41
    // six-bit to ASCII
42
0
    for (i = 0; i < count; i++) {
43
0
        char newchar = sixchr[ubits(bitvec, start + 6 * i, 6U, false)];
44
45
0
        if ('@' == newchar) {
46
0
            break;
47
0
        }
48
0
        to[i] = newchar;
49
0
    }
50
0
    to[i] = '\0';
51
0
}
52
53
// trim spaces on right end
54
static void trim_spaces_on_right_end(char* to, size_t max)
55
0
{
56
0
    long long i;
57
58
    // pacify Coverity 498043, overflow
59
0
    for (i = strnlen(to, max) - 1; i >= 0; i--) {
60
0
        if (' ' == to[i] ||
61
0
            '@' == to[i]) {
62
0
            to[i] = '\0';
63
0
        } else {
64
0
            break;
65
0
        }
66
0
    }
67
0
}
68
69
/* beginning at bitvec bit start, unpack count sixbit characters
70
 * and remove trailing spaces */
71
static void from_sixbit(const unsigned char *bitvec, unsigned int start,
72
                        int count, char *to)
73
0
{
74
0
       from_sixbit_untrimmed(bitvec, start, count, to);
75
0
       trim_spaces_on_right_end(to, count);
76
0
}
77
78
/* decode an AIS binary packet
79
 *
80
 * Return: True on success
81
 *         False on failure
82
 */
83
bool ais_binary_decode(const struct gpsd_errout_t *errout,
84
                       struct ais_t *ais,
85
                       const unsigned char *bits, size_t bitlen,
86
                       struct ais_type24_queue_t *type24_queue)
87
0
{
88
0
    unsigned int u; int i;
89
90
0
#define UBITS(s, l)     ubits(bits, s, l, false)
91
0
#define SBITS(s, l)     sbits(bits, s, l, false)
92
0
#define UCHARS(s, to)   from_sixbit(bits, s, sizeof(to)-1, to)
93
0
#define ENDCHARS(s, to) from_sixbit(bits, s, (bitlen-(s))/6,to)
94
0
    ais->type = UBITS(0, 6);
95
0
    ais->repeat = UBITS(6, 2);
96
0
    ais->mmsi = UBITS(8, 30);
97
0
    GPSD_LOG(LOG_INF, errout, "AIVDM message type %d, MMSI %09d:\n",
98
0
             ais->type, ais->mmsi);
99
100
0
#define PERMISSIVE_LENGTH_CHECK(correct) \
101
0
        if (bitlen < correct) { \
102
0
            GPSD_LOG(LOG_ERROR, errout, \
103
0
                     "AIVDM message type %d size < %d bits (%zd).\n",   \
104
0
                     ais->type, correct, bitlen);                       \
105
0
            return false; \
106
0
        } else if (bitlen > correct) { \
107
0
            GPSD_LOG(LOG_WARN, errout, \
108
0
                     "AIVDM message type %d size > %d bits (%zd).\n",   \
109
0
                     ais->type, correct, bitlen);                       \
110
0
        }
111
112
0
#define RANGE_CHECK(min, max) \
113
0
        if (bitlen < min || bitlen > max) { \
114
0
            GPSD_LOG(LOG_ERROR, errout, \
115
0
                     "AIVDM message type %d size is out of range (%zd).\n", \
116
0
                     ais->type, bitlen);                                \
117
0
            return false; \
118
0
        }
119
120
    /*
121
     * Something about the shape of this switch statement confuses
122
     * GNU indent so badly that there is no point in trying to be
123
     * finer-grained than leaving it all alone.
124
     */
125
    // *INDENT-OFF*
126
0
    switch (ais->type) {
127
0
    case 1:     // Position Report
128
0
        FALLTHROUGH
129
0
    case 2:
130
0
        FALLTHROUGH
131
0
    case 3:
132
        // per https://www.navcen.uscg.gov/ais-class-a-reports
133
        // In 2023, most of our samples are 168, but some are 163 and 204.
134
0
        RANGE_CHECK(163, 204)
135
0
        ais->type1.status       = UBITS(38, 4);
136
0
        ais->type1.turn         = SBITS(42, 8);
137
0
        ais->type1.speed        = UBITS(50, 10);
138
0
        ais->type1.accuracy     = UBITS(60, 1) != 0;
139
0
        ais->type1.lon          = SBITS(61, 28);
140
0
        ais->type1.lat          = SBITS(89, 27);
141
0
        ais->type1.course       = UBITS(116, 12);
142
0
        ais->type1.heading      = UBITS(128, 9);
143
0
        ais->type1.second       = UBITS(137, 6);
144
0
        ais->type1.maneuver     = UBITS(143, 2);
145
        // ais->type1.spare     = UBITS(145, 3);
146
0
        ais->type1.raim         = UBITS(148, 1) != 0;
147
0
        if(bitlen >= 168) {
148
0
            ais->type1.radio        = UBITS(149, 19);
149
0
        } else {
150
            // less than 168, as of 2023 we have no examples of this.
151
0
            ais->type1.radio        = UBITS(149, bitlen - 149);
152
0
        }
153
0
        break;
154
0
    case 4:     // Base Station Report
155
0
        FALLTHROUGH
156
0
    case 11:    // UTC/Date Response
157
0
        PERMISSIVE_LENGTH_CHECK(168)
158
0
        ais->type4.year         = UBITS(38, 14);
159
0
        ais->type4.month        = UBITS(52, 4);
160
0
        ais->type4.day          = UBITS(56, 5);
161
0
        ais->type4.hour         = UBITS(61, 5);
162
0
        ais->type4.minute       = UBITS(66, 6);
163
0
        ais->type4.second       = UBITS(72, 6);
164
0
        ais->type4.accuracy     = UBITS(78, 1) != 0;
165
0
        ais->type4.lon          = SBITS(79, 28);
166
0
        ais->type4.lat          = SBITS(107, 27);
167
0
        ais->type4.epfd         = UBITS(134, 4);
168
        //ais->type4.spare      = UBITS(138, 10);
169
0
        ais->type4.raim         = UBITS(148, 1) != 0;
170
0
        ais->type4.radio        = UBITS(149, 19);
171
0
        break;
172
0
    case 5: // Ship static and voyage related data
173
0
        if (424 != bitlen) {
174
0
            GPSD_LOG(LOG_WARN, errout,
175
0
                     "AIVDM message type 5 size not 424 bits (%zd).\n",
176
0
                     bitlen);
177
            /*
178
             * For unknown reasons, a lot of transmitters in the wild ship
179
             * with a length of 420 or 422.  This is a recoverable error.
180
             */
181
0
            if (420 > bitlen) {
182
0
                return false;
183
0
            }
184
0
        }
185
0
        ais->type5.ais_version  = UBITS(38, 2);
186
0
        ais->type5.imo          = UBITS(40, 30);
187
0
        UCHARS(70, ais->type5.callsign);
188
0
        UCHARS(112, ais->type5.shipname);
189
0
        ais->type5.shiptype     = UBITS(232, 8);
190
0
        ais->type5.to_bow       = UBITS(240, 9);
191
0
        ais->type5.to_stern     = UBITS(249, 9);
192
0
        ais->type5.to_port      = UBITS(258, 6);
193
0
        ais->type5.to_starboard = UBITS(264, 6);
194
0
        ais->type5.epfd         = UBITS(270, 4);
195
0
        ais->type5.month        = UBITS(274, 4);
196
0
        ais->type5.day          = UBITS(278, 5);
197
0
        ais->type5.hour         = UBITS(283, 5);
198
0
        ais->type5.minute       = UBITS(288, 6);
199
0
        ais->type5.draught      = UBITS(294, 8);
200
0
        UCHARS(302, ais->type5.destination);
201
0
        if (423 <= bitlen) {
202
0
            ais->type5.dte          = UBITS(422, 1);
203
0
        }
204
        //ais->type5.spare        = UBITS(423, 1);
205
0
        break;
206
0
    case 6:   // Addressed Binary Message
207
0
        RANGE_CHECK(88, 1008);
208
0
        ais->type6.seqno          = UBITS(38, 2);
209
0
        ais->type6.dest_mmsi      = UBITS(40, 30);
210
0
        ais->type6.retransmit     = UBITS(70, 1) != 0;
211
        //ais->type6.spare        = UBITS(71, 1);
212
0
        ais->type6.dac            = UBITS(72, 10);
213
0
        ais->type6.fid            = UBITS(82, 6);
214
0
        ais->type6.bitcount       = bitlen - 88;
215
        // not strictly required - helps stability in testing
216
0
        (void)memset(ais->type6.bitdata, '\0', sizeof(ais->type6.bitdata));
217
0
        ais->type6.structured = false;
218
        // Inland AIS
219
0
        if (200 == ais->type6.dac) {
220
0
            switch (ais->type6.fid) {
221
0
            case 21:    // ETA at lock/bridge/terminal
222
0
                if (248 != bitlen) {
223
0
                    break;
224
0
                }
225
0
                UCHARS(88, ais->type6.dac200fid21.country);
226
0
                UCHARS(100, ais->type6.dac200fid21.locode);
227
0
                UCHARS(118, ais->type6.dac200fid21.section);
228
0
                UCHARS(148, ais->type6.dac200fid21.terminal);
229
0
                UCHARS(178, ais->type6.dac200fid21.hectometre);
230
0
                ais->type6.dac200fid21.month    = UBITS(208, 4);
231
0
                ais->type6.dac200fid21.day      = UBITS(212, 5);
232
0
                ais->type6.dac200fid21.hour     = UBITS(217, 5);
233
0
                ais->type6.dac200fid21.minute   = UBITS(222, 6);
234
0
                ais->type6.dac200fid21.tugs     = UBITS(228, 3);
235
0
                ais->type6.dac200fid21.airdraught       = UBITS(231, 12);
236
                // skip 5 bits
237
0
                ais->type6.structured = true;
238
0
                break;
239
0
            case 22:    // RTA at lock/bridge/terminal
240
0
                if (232 != bitlen) {
241
0
                    break;
242
0
                }
243
0
                UCHARS(88, ais->type6.dac200fid22.country);
244
0
                UCHARS(100, ais->type6.dac200fid22.locode);
245
0
                UCHARS(118, ais->type6.dac200fid22.section);
246
0
                UCHARS(148, ais->type6.dac200fid22.terminal);
247
0
                UCHARS(178, ais->type6.dac200fid22.hectometre);
248
0
                ais->type6.dac200fid22.month    = UBITS(208, 4);
249
0
                ais->type6.dac200fid22.day      = UBITS(212, 5);
250
0
                ais->type6.dac200fid22.hour     = UBITS(217, 5);
251
0
                ais->type6.dac200fid22.minute   = UBITS(222, 6);
252
0
                ais->type6.dac200fid22.status   = UBITS(228, 2);
253
                // skip 2 bits
254
0
                ais->type6.structured = true;
255
0
                break;
256
0
            case 55:    // Number of Persons On Board
257
0
                if (168 != bitlen) {
258
0
                    break;
259
0
                }
260
0
                ais->type6.dac200fid55.crew       = UBITS(88, 8);
261
0
                ais->type6.dac200fid55.passengers = UBITS(96, 13);
262
0
                ais->type6.dac200fid55.personnel  = UBITS(109, 8);
263
                // skip 51 bits
264
0
                ais->type6.structured = true;
265
0
                break;
266
0
            }
267
0
        }
268
        // UK and Republic Of Ireland
269
0
        else if (235 == ais->type6.dac ||
270
0
                 250 == ais->type6.dac) {
271
0
            switch (ais->type6.fid) {
272
0
            case 10:    // GLA - AtoN monitoring data
273
0
                if (136 != bitlen) {
274
0
                    break;
275
0
                }
276
0
                ais->type6.dac235fid10.ana_int  = UBITS(88, 10);
277
0
                ais->type6.dac235fid10.ana_ext1 = UBITS(98, 10);
278
0
                ais->type6.dac235fid10.ana_ext2 = UBITS(108, 10);
279
0
                ais->type6.dac235fid10.racon    = UBITS(118, 2);
280
0
                ais->type6.dac235fid10.light    = UBITS(120, 2);
281
0
                ais->type6.dac235fid10.alarm    = UBITS(122, 1);
282
0
                ais->type6.dac235fid10.stat_ext = UBITS(123, 8);
283
0
                ais->type6.dac235fid10.off_pos  = UBITS(131, 1);
284
                // skip 4 bits
285
0
                ais->type6.structured = true;
286
0
                break;
287
0
            }
288
0
        }
289
        // International
290
0
        else if (1 == ais->type6.dac)
291
0
            switch (ais->type6.fid) {
292
0
            case 12:    // IMO236 - Dangerous cargo indication
293
0
                UCHARS(88, ais->type6.dac1fid12.lastport);
294
0
                ais->type6.dac1fid12.lmonth     = UBITS(118, 4);
295
0
                ais->type6.dac1fid12.lday       = UBITS(122, 5);
296
0
                ais->type6.dac1fid12.lhour      = UBITS(127, 5);
297
0
                ais->type6.dac1fid12.lminute    = UBITS(132, 6);
298
0
                UCHARS(138, ais->type6.dac1fid12.nextport);
299
0
                ais->type6.dac1fid12.nmonth     = UBITS(168, 4);
300
0
                ais->type6.dac1fid12.nday       = UBITS(172, 5);
301
0
                ais->type6.dac1fid12.nhour      = UBITS(177, 5);
302
0
                ais->type6.dac1fid12.nminute    = UBITS(182, 6);
303
0
                UCHARS(188, ais->type6.dac1fid12.dangerous);
304
0
                UCHARS(308, ais->type6.dac1fid12.imdcat);
305
0
                ais->type6.dac1fid12.unid       = UBITS(332, 13);
306
0
                ais->type6.dac1fid12.amount     = UBITS(345, 10);
307
0
                ais->type6.dac1fid12.unit       = UBITS(355, 2);
308
                // skip 3 bits
309
0
                ais->type6.structured = true;
310
0
                break;
311
0
            case 14:    // IMO236 - Tidal Window
312
0
                ais->type6.dac1fid32.month      = UBITS(88, 4);
313
0
                ais->type6.dac1fid32.day        = UBITS(92, 5);
314
0
#define ARRAY_BASE 97
315
0
#define ELEMENT_SIZE 93
316
0
                for (u = 0; ARRAY_BASE + (ELEMENT_SIZE*u) <= bitlen; u++) {
317
0
                    int a = ARRAY_BASE + (ELEMENT_SIZE*u);
318
0
                    struct tidal_t *tp = &ais->type6.dac1fid32.tidals[u];
319
0
                    tp->lat       = SBITS(a + 0, 27);
320
0
                    tp->lon       = SBITS(a + 27, 28);
321
0
                    tp->from_hour = UBITS(a + 55, 5);
322
0
                    tp->from_min  = UBITS(a + 60, 6);
323
0
                    tp->to_hour   = UBITS(a + 66, 5);
324
0
                    tp->to_min    = UBITS(a + 71, 6);
325
0
                    tp->cdir      = UBITS(a + 77, 9);
326
0
                    tp->cspeed    = UBITS(a + 86, 7);
327
0
                }
328
0
                ais->type6.dac1fid32.ntidals = u;
329
0
#undef ARRAY_BASE
330
0
#undef ELEMENT_SIZE
331
0
                ais->type6.structured = true;
332
0
                break;
333
0
            case 15:
334
                // IMO236 - Extended Ship Static and Voyage Related Data
335
0
                ais->type6.dac1fid15.airdraught = UBITS(56, 11);
336
0
                ais->type6.structured = true;
337
0
                break;
338
0
            case 16:    // IMO236 - Number of persons on board
339
0
                if (136 == ais->type6.bitcount) {
340
0
                    ais->type6.dac1fid16.persons = UBITS(88, 13);  // 289
341
0
                } else {
342
0
                    ais->type6.dac1fid16.persons = UBITS(55, 13);  // 236
343
0
                }
344
0
                ais->type6.structured = true;
345
0
                break;
346
0
            case 18:    // IMO289 - Clearance time to enter port
347
0
                ais->type6.dac1fid18.linkage    = UBITS(88, 10);
348
0
                ais->type6.dac1fid18.month      = UBITS(98, 4);
349
0
                ais->type6.dac1fid18.day        = UBITS(102, 5);
350
0
                ais->type6.dac1fid18.hour       = UBITS(107, 5);
351
0
                ais->type6.dac1fid18.minute     = UBITS(112, 6);
352
0
                UCHARS(118, ais->type6.dac1fid18.portname);
353
0
                UCHARS(238, ais->type6.dac1fid18.destination);
354
0
                ais->type6.dac1fid18.lon        = SBITS(268, 25);
355
0
                ais->type6.dac1fid18.lat        = SBITS(293, 24);
356
                // skip 43 bits
357
0
                ais->type6.structured = true;
358
0
                break;
359
0
            case 20:    // IMO289 - Berthing data - addressed
360
0
                ais->type6.dac1fid20.linkage      = UBITS(88, 10);
361
0
                ais->type6.dac1fid20.berth_length = UBITS(98, 9);
362
0
                ais->type6.dac1fid20.berth_depth  = UBITS(107, 8);
363
0
                ais->type6.dac1fid20.position     = UBITS(115, 3);
364
0
                ais->type6.dac1fid20.month        = UBITS(118, 4);
365
0
                ais->type6.dac1fid20.day          = UBITS(122, 5);
366
0
                ais->type6.dac1fid20.hour         = UBITS(127, 5);
367
0
                ais->type6.dac1fid20.minute       = UBITS(132, 6);
368
0
                ais->type6.dac1fid20.availability = UBITS(138, 1);
369
0
                ais->type6.dac1fid20.agent        = UBITS(139, 2);
370
0
                ais->type6.dac1fid20.fuel         = UBITS(141, 2);
371
0
                ais->type6.dac1fid20.chandler     = UBITS(143, 2);
372
0
                ais->type6.dac1fid20.stevedore    = UBITS(145, 2);
373
0
                ais->type6.dac1fid20.electrical   = UBITS(147, 2);
374
0
                ais->type6.dac1fid20.water        = UBITS(149, 2);
375
0
                ais->type6.dac1fid20.customs      = UBITS(151, 2);
376
0
                ais->type6.dac1fid20.cartage      = UBITS(153, 2);
377
0
                ais->type6.dac1fid20.crane        = UBITS(155, 2);
378
0
                ais->type6.dac1fid20.lift         = UBITS(157, 2);
379
0
                ais->type6.dac1fid20.medical      = UBITS(159, 2);
380
0
                ais->type6.dac1fid20.navrepair    = UBITS(161, 2);
381
0
                ais->type6.dac1fid20.provisions   = UBITS(163, 2);
382
0
                ais->type6.dac1fid20.shiprepair   = UBITS(165, 2);
383
0
                ais->type6.dac1fid20.surveyor     = UBITS(167, 2);
384
0
                ais->type6.dac1fid20.steam        = UBITS(169, 2);
385
0
                ais->type6.dac1fid20.tugs         = UBITS(171, 2);
386
0
                ais->type6.dac1fid20.solidwaste   = UBITS(173, 2);
387
0
                ais->type6.dac1fid20.liquidwaste  = UBITS(175, 2);
388
0
                ais->type6.dac1fid20.hazardouswaste = UBITS(177, 2);
389
0
                ais->type6.dac1fid20.ballast      = UBITS(179, 2);
390
0
                ais->type6.dac1fid20.additional   = UBITS(181, 2);
391
0
                ais->type6.dac1fid20.regional1    = UBITS(183, 2);
392
0
                ais->type6.dac1fid20.regional2    = UBITS(185, 2);
393
0
                ais->type6.dac1fid20.future1      = UBITS(187, 2);
394
0
                ais->type6.dac1fid20.future2      = UBITS(189, 2);
395
0
                UCHARS(191, ais->type6.dac1fid20.berth_name);
396
0
                ais->type6.dac1fid20.berth_lon    = SBITS(311, 25);
397
0
                ais->type6.dac1fid20.berth_lat    = SBITS(336, 24);
398
0
                ais->type6.structured = true;
399
0
                break;
400
0
            case 23:        // IMO289 - Area notice - addressed
401
0
                break;
402
0
            case 25:    // IMO289 - Dangerous cargo indication
403
0
                ais->type6.dac1fid25.unit       = UBITS(88, 2);
404
0
                ais->type6.dac1fid25.amount     = UBITS(90, 10);
405
0
                for (u = 0; 100 + u*17 < bitlen; u++) {
406
0
                    ais->type6.dac1fid25.cargos[u].code =
407
0
                        UBITS(100 + u * 17, 4);
408
0
                    ais->type6.dac1fid25.cargos[u].subtype =
409
0
                        UBITS(104 + u * 17, 13);
410
0
                }
411
0
                ais->type6.dac1fid25.ncargos = u;
412
0
                ais->type6.structured = true;
413
0
                break;
414
0
            case 28:    // IMO289 - Route info - addressed
415
0
                ais->type6.dac1fid28.linkage    = UBITS(88, 10);
416
0
                ais->type6.dac1fid28.sender     = UBITS(98, 3);
417
0
                ais->type6.dac1fid28.rtype      = UBITS(101, 5);
418
0
                ais->type6.dac1fid28.month      = UBITS(106, 4);
419
0
                ais->type6.dac1fid28.day        = UBITS(110, 5);
420
0
                ais->type6.dac1fid28.hour       = UBITS(115, 5);
421
0
                ais->type6.dac1fid28.minute     = UBITS(120, 6);
422
0
                ais->type6.dac1fid28.duration   = UBITS(126, 18);
423
0
                ais->type6.dac1fid28.waycount   = UBITS(144, 5);
424
0
#define ARRAY_BASE 149
425
0
#define ELEMENT_SIZE 55
426
0
                for (u = 0;
427
0
                     u < (unsigned char)ais->type6.dac1fid28.waycount; u++) {
428
0
                    int a = ARRAY_BASE + (ELEMENT_SIZE*u);
429
0
                    ais->type6.dac1fid28.waypoints[u].lon = SBITS(a + 0, 28);
430
0
                    ais->type6.dac1fid28.waypoints[u].lat = SBITS(a + 28, 27);
431
0
                }
432
0
#undef ARRAY_BASE
433
0
#undef ELEMENT_SIZE
434
0
                ais->type6.structured = true;
435
0
                break;
436
0
            case 30:    // IMO289 - Text description - addressed
437
0
                ais->type6.dac1fid30.linkage   = UBITS(88, 10);
438
0
                ENDCHARS(98, ais->type6.dac1fid30.text);
439
0
                ais->type6.structured = true;
440
0
                break;
441
0
            case 32:    // IMO289 - Tidal Window
442
0
                ais->type6.dac1fid32.month      = UBITS(88, 4);
443
0
                ais->type6.dac1fid32.day        = UBITS(92, 5);
444
0
#define ARRAY_BASE 97
445
0
#define ELEMENT_SIZE 88
446
0
                for (u = 0; ARRAY_BASE + (ELEMENT_SIZE*u) <= bitlen; u++) {
447
0
                    int a = ARRAY_BASE + (ELEMENT_SIZE*u);
448
0
                    struct tidal_t *tp = &ais->type6.dac1fid32.tidals[u];
449
0
                    tp->lon       = SBITS(a + 0, 25);
450
0
                    tp->lat       = SBITS(a + 25, 24);
451
0
                    tp->from_hour = UBITS(a + 49, 5);
452
0
                    tp->from_min  = UBITS(a + 54, 6);
453
0
                    tp->to_hour   = UBITS(a + 60, 5);
454
0
                    tp->to_min    = UBITS(a + 65, 6);
455
0
                    tp->cdir      = UBITS(a + 71, 9);
456
0
                    tp->cspeed    = UBITS(a + 80, 8);
457
0
                }
458
0
                ais->type6.dac1fid32.ntidals = u;
459
0
#undef ARRAY_BASE
460
0
#undef ELEMENT_SIZE
461
0
                ais->type6.structured = true;
462
0
                break;
463
0
            }
464
0
        if (!ais->type6.structured) {
465
0
            (void)memcpy(ais->type6.bitdata, bits + (88 / CHAR_BIT),
466
0
                         BITS_TO_BYTES(ais->type6.bitcount));
467
0
        }
468
0
        break;
469
0
    case 7:    // Binary acknowledge
470
0
        FALLTHROUGH
471
0
    case 13:   // Safety Related Acknowledge
472
0
    {
473
0
        unsigned int mmsi[4];
474
0
        unsigned seqno[4];
475
0
        RANGE_CHECK(72, 168);
476
0
        for (u = 0; u < sizeof(mmsi)/sizeof(mmsi[0]); u++) {
477
0
            if (40 + 32 * u < bitlen) {
478
0
                mmsi[u] = UBITS(40 + 32 * u, 30);
479
0
                seqno[u] = UBITS(72 + 32 * u, 2);
480
0
            } else {
481
0
                mmsi[u] = 0;
482
0
                seqno[u] = 0;
483
0
            }
484
0
        }
485
0
        ais->type7.mmsi1 = mmsi[0];
486
0
        ais->type7.seqno1 = seqno[0];
487
0
        ais->type7.mmsi2 = mmsi[1];
488
0
        ais->type7.seqno2 = seqno[1];
489
0
        ais->type7.mmsi3 = mmsi[2];
490
0
        ais->type7.seqno3 = seqno[2];
491
0
        ais->type7.mmsi4 = mmsi[3];
492
0
        ais->type7.seqno4 = seqno[3];
493
0
        break;
494
0
    }
495
0
    case 8: // Binary Broadcast Message
496
0
        RANGE_CHECK(56, 1008);
497
        //ais->type8.spare        = UBITS(38, 2);
498
0
        ais->type8.dac            = UBITS(40, 10);
499
0
        ais->type8.fid            = UBITS(50, 6);
500
0
        ais->type8.bitcount       = bitlen - 56;
501
        // not strictly required - helps stability in testing
502
0
        (void)memset(ais->type8.bitdata, '\0', sizeof(ais->type8.bitdata));
503
0
        ais->type8.structured = false;
504
0
        if (1 == ais->type8.dac)
505
0
            switch (ais->type8.fid) {
506
0
            case 11:        // IMO236 - Meteorological/Hydrological data
507
                // layout is almost identical to FID=31 from IMO289
508
0
                ais->type8.dac1fid11.lat        = SBITS(56, 24);
509
0
                ais->type8.dac1fid11.lon        = SBITS(80, 25);
510
0
                ais->type8.dac1fid11.day        = UBITS(105, 5);
511
0
                ais->type8.dac1fid11.hour       = UBITS(110, 5);
512
0
                ais->type8.dac1fid11.minute     = UBITS(115, 6);
513
0
                ais->type8.dac1fid11.wspeed     = UBITS(121, 7);
514
0
                ais->type8.dac1fid11.wgust      = UBITS(128, 7);
515
0
                ais->type8.dac1fid11.wdir       = UBITS(135, 9);
516
0
                ais->type8.dac1fid11.wgustdir   = UBITS(144, 9);
517
0
                ais->type8.dac1fid11.airtemp    = UBITS(153, 11);
518
0
                ais->type8.dac1fid11.humidity   = UBITS(164, 7);
519
0
                ais->type8.dac1fid11.dewpoint   = UBITS(171, 10);
520
0
                ais->type8.dac1fid11.pressure   = UBITS(181, 9);
521
0
                ais->type8.dac1fid11.pressuretend       = UBITS(190, 2);
522
0
                ais->type8.dac1fid11.visibility = UBITS(192, 8);
523
0
                ais->type8.dac1fid11.waterlevel = UBITS(200, 9);
524
0
                ais->type8.dac1fid11.leveltrend = UBITS(209, 2);
525
0
                ais->type8.dac1fid11.cspeed     = UBITS(211, 8);
526
0
                ais->type8.dac1fid11.cdir       = UBITS(219, 9);
527
0
                ais->type8.dac1fid11.cspeed2    = UBITS(228, 8);
528
0
                ais->type8.dac1fid11.cdir2      = UBITS(236, 9);
529
0
                ais->type8.dac1fid11.cdepth2    = UBITS(245, 5);
530
0
                ais->type8.dac1fid11.cspeed3    = UBITS(250, 8);
531
0
                ais->type8.dac1fid11.cdir3      = UBITS(258, 9);
532
0
                ais->type8.dac1fid11.cdepth3    = UBITS(267, 5);
533
0
                ais->type8.dac1fid11.waveheight = UBITS(272, 8);
534
0
                ais->type8.dac1fid11.waveperiod = UBITS(280, 6);
535
0
                ais->type8.dac1fid11.wavedir    = UBITS(286, 9);
536
0
                ais->type8.dac1fid11.swellheight        = UBITS(295, 8);
537
0
                ais->type8.dac1fid11.swellperiod        = UBITS(303, 6);
538
0
                ais->type8.dac1fid11.swelldir   = UBITS(309, 9);
539
0
                ais->type8.dac1fid11.seastate   = UBITS(318, 4);
540
0
                ais->type8.dac1fid11.watertemp  = UBITS(322, 10);
541
0
                ais->type8.dac1fid11.preciptype = UBITS(332, 3);
542
0
                ais->type8.dac1fid11.salinity   = UBITS(335, 9);
543
0
                ais->type8.dac1fid11.ice        = UBITS(344, 2);
544
0
                ais->type8.structured = true;
545
0
                break;
546
0
            case 13:        // IMO236 - Fairway closed
547
0
                UCHARS(56, ais->type8.dac1fid13.reason);
548
0
                UCHARS(176, ais->type8.dac1fid13.closefrom);
549
0
                UCHARS(296, ais->type8.dac1fid13.closeto);
550
0
                ais->type8.dac1fid13.radius     = UBITS(416, 10);
551
0
                ais->type8.dac1fid13.extunit    = UBITS(426, 2);
552
0
                ais->type8.dac1fid13.fday       = UBITS(428, 5);
553
0
                ais->type8.dac1fid13.fmonth     = UBITS(433, 4);
554
0
                ais->type8.dac1fid13.fhour      = UBITS(437, 5);
555
0
                ais->type8.dac1fid13.fminute    = UBITS(442, 6);
556
0
                ais->type8.dac1fid13.tday       = UBITS(448, 5);
557
0
                ais->type8.dac1fid13.tmonth     = UBITS(453, 4);
558
0
                ais->type8.dac1fid13.thour      = UBITS(457, 5);
559
0
                ais->type8.dac1fid13.tminute    = UBITS(462, 6);
560
                // skip 4 bits
561
0
                ais->type8.structured = true;
562
0
                break;
563
0
            case 15:        // IMO236 - Extended ship and voyage
564
0
                ais->type8.dac1fid15.airdraught = UBITS(56, 11);
565
                // skip 5 bits
566
0
                ais->type8.structured = true;
567
0
                break;
568
0
            case 16:        // Number of Persons On Board
569
0
                if (136 == ais->type8.bitcount) {
570
0
                    ais->type8.dac1fid16.persons = UBITS(88, 13);  // 289
571
0
                    ais->type8.structured = true;
572
0
                } else if (72 == ais->type8.bitcount) {
573
0
                    ais->type8.dac1fid16.persons = UBITS(55, 13);  // 236
574
0
                    ais->type8.structured = true;
575
0
                }
576
0
                break;
577
0
            case 17:        // IMO289 - VTS-generated/synthetic targets
578
0
#define ARRAY_BASE 56
579
0
#define ELEMENT_SIZE 122
580
0
                for (u = 0; ARRAY_BASE + (ELEMENT_SIZE * u) <= bitlen; u++) {
581
0
                    struct target_t *tp = &ais->type8.dac1fid17.targets[u];
582
0
                    int a = ARRAY_BASE + (ELEMENT_SIZE * u);
583
0
                    tp->idtype = UBITS(a + 0, 2);
584
0
                    switch (tp->idtype) {
585
0
                    case DAC1FID17_IDTYPE_MMSI:
586
0
                        tp->id.mmsi     = UBITS(a + 2, 42);
587
0
                        break;
588
0
                    case DAC1FID17_IDTYPE_IMO:
589
0
                        tp->id.imo      = UBITS(a + 2, 42);
590
0
                        break;
591
0
                    case DAC1FID17_IDTYPE_CALLSIGN:
592
0
                        UCHARS(a + 2, tp->id.callsign);
593
0
                        break;
594
0
                    default:
595
0
                        UCHARS(a + 2, tp->id.other);
596
0
                        break;
597
0
                    }
598
                    // skip 4 bits
599
0
                    tp->lat     = SBITS(a + 48, 24);
600
0
                    tp->lon     = SBITS(a + 72, 25);
601
0
                    tp->course  = UBITS(a + 97, 9);
602
0
                    tp->second  = UBITS(a + 106, 6);
603
0
                    tp->speed   = UBITS(a + 112, 10);
604
0
                }
605
0
                ais->type8.dac1fid17.ntargets = u;
606
0
#undef ARRAY_BASE
607
0
#undef ELEMENT_SIZE
608
0
                ais->type8.structured = true;
609
0
                break;
610
0
            case 19:        // IMO289 - Marine Traffic Signal
611
0
                ais->type8.dac1fid19.linkage    = UBITS(56, 10);
612
0
                UCHARS(66, ais->type8.dac1fid19.station);
613
0
                ais->type8.dac1fid19.lon        = SBITS(186, 25);
614
0
                ais->type8.dac1fid19.lat        = SBITS(211, 24);
615
0
                ais->type8.dac1fid19.status     = UBITS(235, 2);
616
0
                ais->type8.dac1fid19.signal     = UBITS(237, 5);
617
0
                ais->type8.dac1fid19.hour       = UBITS(242, 5);
618
0
                ais->type8.dac1fid19.minute     = UBITS(247, 6);
619
0
                ais->type8.dac1fid19.nextsignal = UBITS(253, 5);
620
                // skip 102 bits
621
0
                ais->type8.structured = true;
622
0
                break;
623
0
            case 21:        // IMO289 - Weather obs. report from ship
624
0
                break;
625
0
            case 22:        // IMO289 - Area notice - broadcast
626
0
                break;
627
0
            case 24:
628
                // IMO289 - Extended ship static & voyage-related data
629
0
                break;
630
0
            case 26:        // IMO289 - Environmental
631
0
                break;
632
0
            case 27:        // IMO289 - Route information - broadcast
633
0
                ais->type8.dac1fid27.linkage    = UBITS(56, 10);
634
0
                ais->type8.dac1fid27.sender     = UBITS(66, 3);
635
0
                ais->type8.dac1fid27.rtype      = UBITS(69, 5);
636
0
                ais->type8.dac1fid27.month      = UBITS(74, 4);
637
0
                ais->type8.dac1fid27.day        = UBITS(78, 5);
638
0
                ais->type8.dac1fid27.hour       = UBITS(83, 5);
639
0
                ais->type8.dac1fid27.minute     = UBITS(88, 6);
640
0
                ais->type8.dac1fid27.duration   = UBITS(94, 18);
641
0
                ais->type8.dac1fid27.waycount   = UBITS(112, 5);
642
0
#define ARRAY_BASE 117
643
0
#define ELEMENT_SIZE 55
644
0
                for (i = 0; i < ais->type8.dac1fid27.waycount; i++) {
645
0
                    int a = ARRAY_BASE + (ELEMENT_SIZE*i);
646
0
                    ais->type8.dac1fid27.waypoints[i].lon = SBITS(a + 0, 28);
647
0
                    ais->type8.dac1fid27.waypoints[i].lat = SBITS(a + 28, 27);
648
0
                }
649
0
#undef ARRAY_BASE
650
0
#undef ELEMENT_SIZE
651
0
                ais->type8.structured = true;
652
0
                break;
653
0
            case 29:        // IMO289 - Text Description - broadcast
654
0
                ais->type8.dac1fid29.linkage   = UBITS(56, 10);
655
0
                ENDCHARS(66, ais->type8.dac1fid29.text);
656
0
                ais->type8.structured = true;
657
0
                break;
658
0
            case 31:        // IMO289 - Meteorological/Hydrological data
659
0
                ais->type8.dac1fid31.lon        = SBITS(56, 25);
660
0
                ais->type8.dac1fid31.lat        = SBITS(81, 24);
661
0
                ais->type8.dac1fid31.accuracy   = (bool)UBITS(105, 1);
662
0
                ais->type8.dac1fid31.day        = UBITS(106, 5);
663
0
                ais->type8.dac1fid31.hour       = UBITS(111, 5);
664
0
                ais->type8.dac1fid31.minute     = UBITS(116, 6);
665
0
                ais->type8.dac1fid31.wspeed     = UBITS(122, 7);
666
0
                ais->type8.dac1fid31.wgust      = UBITS(129, 7);
667
0
                ais->type8.dac1fid31.wdir       = UBITS(136, 9);
668
0
                ais->type8.dac1fid31.wgustdir   = UBITS(145, 9);
669
0
                ais->type8.dac1fid31.airtemp    = SBITS(154, 11);
670
0
                ais->type8.dac1fid31.humidity   = UBITS(165, 7);
671
0
                ais->type8.dac1fid31.dewpoint   = SBITS(172, 10);
672
0
                ais->type8.dac1fid31.pressure   = UBITS(182, 9);
673
0
                ais->type8.dac1fid31.pressuretend       = UBITS(191, 2);
674
0
                ais->type8.dac1fid31.visgreater = UBITS(193, 1);
675
0
                ais->type8.dac1fid31.visibility = UBITS(194, 7);
676
0
                ais->type8.dac1fid31.waterlevel = UBITS(201, 12);
677
0
                ais->type8.dac1fid31.leveltrend = UBITS(213, 2);
678
0
                ais->type8.dac1fid31.cspeed     = UBITS(215, 8);
679
0
                ais->type8.dac1fid31.cdir       = UBITS(223, 9);
680
0
                ais->type8.dac1fid31.cspeed2    = UBITS(232, 8);
681
0
                ais->type8.dac1fid31.cdir2      = UBITS(240, 9);
682
0
                ais->type8.dac1fid31.cdepth2    = UBITS(249, 5);
683
0
                ais->type8.dac1fid31.cspeed3    = UBITS(254, 8);
684
0
                ais->type8.dac1fid31.cdir3      = UBITS(262, 9);
685
0
                ais->type8.dac1fid31.cdepth3    = UBITS(271, 5);
686
0
                ais->type8.dac1fid31.waveheight = UBITS(276, 8);
687
0
                ais->type8.dac1fid31.waveperiod = UBITS(284, 6);
688
0
                ais->type8.dac1fid31.wavedir    = UBITS(290, 9);
689
0
                ais->type8.dac1fid31.swellheight = UBITS(299, 8);
690
0
                ais->type8.dac1fid31.swellperiod = UBITS(307, 6);
691
0
                ais->type8.dac1fid31.swelldir   = UBITS(313, 9);
692
0
                ais->type8.dac1fid31.seastate   = UBITS(322, 4);
693
0
                ais->type8.dac1fid31.watertemp  = SBITS(326, 10);
694
0
                ais->type8.dac1fid31.preciptype = UBITS(336, 3);
695
0
                ais->type8.dac1fid31.salinity   = UBITS(339, 9);
696
0
                ais->type8.dac1fid31.ice        = UBITS(348, 2);
697
0
                ais->type8.structured = true;
698
0
                break;
699
0
            }
700
0
        else if (200 == ais->type8.dac) {
701
0
            switch (ais->type8.fid) {
702
0
            case 10:    // Inland ship static and voyage related data
703
0
                if (168 != bitlen) {
704
0
                    break;
705
0
                }
706
0
                UCHARS(56, ais->type8.dac200fid10.vin);
707
0
                ais->type8.dac200fid10.length   = UBITS(104, 13);
708
0
                ais->type8.dac200fid10.beam     = UBITS(117, 10);
709
0
                ais->type8.dac200fid10.shiptype = UBITS(127, 14);
710
0
                ais->type8.dac200fid10.hazard   = UBITS(141, 3);
711
0
                ais->type8.dac200fid10.draught  = UBITS(144, 11);
712
0
                ais->type8.dac200fid10.loaded   = UBITS(155, 2);
713
0
                ais->type8.dac200fid10.speed_q  = (bool)UBITS(157, 1);
714
0
                ais->type8.dac200fid10.course_q = (bool)UBITS(158, 1);
715
0
                ais->type8.dac200fid10.heading_q = (bool)UBITS(159, 1);
716
                // skip 8 bits
717
                /*
718
                 * Attempt to prevent false matches with this message type
719
                 * by range-checking certain fields.
720
                 */
721
0
                if (DAC200FID10_HAZARD_MAX < ais->type8.dac200fid10.hazard ||
722
0
                    !isascii((int)ais->type8.dac200fid10.vin[0])) {
723
0
                    ais->type8.structured = false;
724
0
                } else {
725
0
                    ais->type8.structured = true;
726
0
                }
727
0
                break;
728
0
            case 23:    // EMMA warning
729
0
                if (256 != bitlen) {
730
0
                    break;
731
0
                }
732
0
                ais->type8.dac200fid23.start_year       = UBITS(56, 8);
733
0
                ais->type8.dac200fid23.start_month      = UBITS(64, 4);
734
0
                ais->type8.dac200fid23.start_day        = UBITS(68, 5);
735
0
                ais->type8.dac200fid23.end_year         = UBITS(73, 8);
736
0
                ais->type8.dac200fid23.end_month        = UBITS(81, 4);
737
0
                ais->type8.dac200fid23.end_day          = UBITS(85, 5);
738
0
                ais->type8.dac200fid23.start_hour       = UBITS(90, 5);
739
0
                ais->type8.dac200fid23.start_minute     = UBITS(95, 6);
740
0
                ais->type8.dac200fid23.end_hour         = UBITS(101, 5);
741
0
                ais->type8.dac200fid23.end_minute       = UBITS(106, 6);
742
0
                ais->type8.dac200fid23.start_lon        = SBITS(112, 28);
743
0
                ais->type8.dac200fid23.start_lat        = SBITS(140, 27);
744
0
                ais->type8.dac200fid23.end_lon          = SBITS(167, 28);
745
0
                ais->type8.dac200fid23.end_lat          = SBITS(195, 27);
746
0
                ais->type8.dac200fid23.type             = UBITS(222, 4);
747
0
                ais->type8.dac200fid23.min              = SBITS(226, 9);
748
0
                ais->type8.dac200fid23.max              = SBITS(235, 9);
749
0
                ais->type8.dac200fid23.intensity        = UBITS(244, 2);
750
0
                ais->type8.dac200fid23.wind             = UBITS(246, 4);
751
                // skip 6 bits
752
0
                ais->type8.structured = true;
753
0
                break;
754
0
            case 24:    // Water level
755
0
                if (168 != bitlen) {
756
0
                    break;
757
0
                }
758
0
                UCHARS(56, ais->type8.dac200fid24.country);
759
0
#define ARRAY_BASE 68
760
0
#define ELEMENT_SIZE 25
761
0
                for (i = 0; ARRAY_BASE + (ELEMENT_SIZE * i) < (int)bitlen;
762
0
                     i++) {
763
0
                    int a = ARRAY_BASE + (ELEMENT_SIZE * i);
764
0
                    ais->type8.dac200fid24.gauges[i].id = UBITS(a + 0,  11);
765
0
                    ais->type8.dac200fid24.gauges[i].level = SBITS(a + 11, 14);
766
0
                }
767
0
                ais->type8.dac200fid24.ngauges = i;
768
0
#undef ARRAY_BASE
769
0
#undef ELEMENT_SIZE
770
                // skip 6 bits
771
0
                ais->type8.structured = true;
772
0
                break;
773
0
            case 40:    // Signal status
774
0
                if (168 != bitlen) {
775
0
                    break;
776
0
                }
777
0
                ais->type8.dac200fid40.lon              = SBITS(56, 28);
778
0
                ais->type8.dac200fid40.lat              = SBITS(84, 27);
779
0
                ais->type8.dac200fid40.form             = UBITS(111, 4);
780
0
                ais->type8.dac200fid40.facing           = UBITS(115, 9);
781
0
                ais->type8.dac200fid40.direction        = UBITS(124, 3);
782
0
                ais->type8.dac200fid40.status           = UBITS(127, 30);
783
                // skip 11 bits
784
0
                ais->type8.structured = true;
785
0
                break;
786
0
            }
787
0
        }
788
        // land here if we failed to match a known DAC/FID
789
0
        if (!ais->type8.structured) {
790
0
            size_t number_of_bytes = BITS_TO_BYTES(ais->type8.bitcount);
791
0
            (void)memcpy(ais->type8.bitdata, bits + (56 / CHAR_BIT),
792
0
                         number_of_bytes);
793
0
            size_t valid_bits_in_last_byte = ais->type8.bitcount % CHAR_BIT;
794
0
            if(valid_bits_in_last_byte > 0) {
795
0
                    ais->type8.bitdata[number_of_bytes - 1] &=
796
0
                            (0xFF << (8 - valid_bits_in_last_byte));
797
0
            }
798
0
        }
799
0
        break;
800
0
    case 9: // Standard SAR Aircraft Position Report
801
0
        PERMISSIVE_LENGTH_CHECK(168);
802
0
        ais->type9.alt          = UBITS(38, 12);
803
0
        ais->type9.speed        = UBITS(50, 10);
804
0
        ais->type9.accuracy     = (bool)UBITS(60, 1);
805
0
        ais->type9.lon          = SBITS(61, 28);
806
0
        ais->type9.lat          = SBITS(89, 27);
807
0
        ais->type9.course       = UBITS(116, 12);
808
0
        ais->type9.second       = UBITS(128, 6);
809
0
        ais->type9.regional     = UBITS(134, 8);
810
0
        ais->type9.dte          = UBITS(142, 1);
811
        //ais->type9.spare      = UBITS(143, 3);
812
0
        ais->type9.assigned     = UBITS(146, 1) != 0;
813
0
        ais->type9.raim         = UBITS(147, 1) != 0;
814
0
        ais->type9.radio        = UBITS(148, 20);
815
0
        break;
816
0
    case 10: // UTC/Date inquiry
817
0
        PERMISSIVE_LENGTH_CHECK(72);
818
        //ais->type10.spare        = UBITS(38, 2);
819
0
        ais->type10.dest_mmsi      = UBITS(40, 30);
820
        //ais->type10.spare2       = UBITS(70, 2);
821
0
        break;
822
0
    case 12: // Safety Related Message
823
0
        RANGE_CHECK(72, 1008);
824
0
        ais->type12.seqno          = UBITS(38, 2);
825
0
        ais->type12.dest_mmsi      = UBITS(40, 30);
826
0
        ais->type12.retransmit     = (bool)UBITS(70, 1);
827
        //ais->type12.spare        = UBITS(71, 1);
828
0
        ENDCHARS(72, ais->type12.text);
829
0
        break;
830
0
    case 14:    // Safety Related Broadcast Message
831
0
        RANGE_CHECK(40, 1008);
832
        //ais->type14.spare          = UBITS(38, 2);
833
0
        ENDCHARS(40, ais->type14.text);
834
0
        break;
835
0
    case 15:    // Interrogation
836
0
        RANGE_CHECK(88, 168);
837
0
        (void)memset(&ais->type15, '\0', sizeof(ais->type15));
838
        //ais->type14.spare         = UBITS(38, 2);
839
0
        ais->type15.mmsi1           = UBITS(40, 30);
840
0
        ais->type15.type1_1         = UBITS(70, 6);
841
0
        ais->type15.type1_1         = UBITS(70, 6);
842
0
        ais->type15.offset1_1       = UBITS(76, 12);
843
        //ais->type14.spare2        = UBITS(88, 2);
844
0
        if (90 < bitlen) {
845
0
            ais->type15.type1_2       = UBITS(90, 6);
846
0
            ais->type15.offset1_2     = UBITS(96, 12);
847
            //ais->type14.spare3      = UBITS(108, 2);
848
0
            if (110 < bitlen) {
849
0
                ais->type15.mmsi2       = UBITS(110, 30);
850
0
                ais->type15.type2_1     = UBITS(140, 6);
851
0
                ais->type15.offset2_1   = UBITS(146, 12);
852
                //ais->type14.spare4    = UBITS(158, 2);
853
0
            }
854
0
        }
855
0
        break;
856
0
    case 16:    // Assigned Mode Command
857
0
        RANGE_CHECK(96, 168);
858
0
        ais->type16.mmsi1       = UBITS(40, 30);
859
0
        ais->type16.offset1     = UBITS(70, 12);
860
0
        ais->type16.increment1  = UBITS(82, 10);
861
0
        if (144 > bitlen) {
862
0
            ais->type16.mmsi2=ais->type16.offset2=ais->type16.increment2 = 0;
863
0
        } else {
864
0
            ais->type16.mmsi2   = UBITS(92, 30);
865
0
            ais->type16.offset2 = UBITS(122, 12);
866
0
            ais->type16.increment2      = UBITS(134, 10);
867
0
        }
868
0
        break;
869
0
    case 17:    // GNSS Broadcast Binary Message
870
0
        RANGE_CHECK(80, 816);
871
        //ais->type17.spare     = UBITS(38, 2);
872
0
        ais->type17.lon         = SBITS(40, 18);
873
0
        ais->type17.lat         = SBITS(58, 17);
874
        //ais->type17.spare     = UBITS(75, 5);
875
0
        ais->type17.bitcount    = bitlen - 80;
876
0
        (void)memcpy(ais->type17.bitdata, bits + (80 / CHAR_BIT),
877
0
                     BITS_TO_BYTES(ais->type17.bitcount));
878
0
        break;
879
0
    case 18:    // Standard Class B CS Position Report
880
        // Per https://www.navcen.uscg.gov/ais-class-b-reports
881
0
        PERMISSIVE_LENGTH_CHECK(168)
882
0
        ais->type18.reserved    = UBITS(38, 8);
883
0
        ais->type18.speed       = UBITS(46, 10);
884
0
        ais->type18.accuracy    = UBITS(56, 1) != 0;
885
0
        ais->type18.lon         = SBITS(57, 28);
886
0
        ais->type18.lat         = SBITS(85, 27);
887
0
        ais->type18.course      = UBITS(112, 12);
888
0
        ais->type18.heading     = UBITS(124, 9);
889
0
        ais->type18.second      = UBITS(133, 6);
890
0
        ais->type18.regional    = UBITS(139, 2);
891
0
        ais->type18.cs          = UBITS(141, 1) != 0;
892
0
        ais->type18.display     = UBITS(142, 1) != 0;
893
0
        ais->type18.dsc         = UBITS(143, 1) != 0;
894
0
        ais->type18.band        = UBITS(144, 1) != 0;
895
0
        ais->type18.msg22       = UBITS(145, 1) != 0;
896
0
        ais->type18.assigned    = UBITS(146, 1) != 0;
897
0
        ais->type18.raim        = UBITS(147, 1) != 0;
898
0
        ais->type18.radio       = UBITS(148, 20);
899
0
        break;
900
0
    case 19:    // Extended Class B CS Position Report
901
0
        PERMISSIVE_LENGTH_CHECK(312)
902
0
        ais->type19.reserved     = UBITS(38, 8);
903
0
        ais->type19.speed        = UBITS(46, 10);
904
0
        ais->type19.accuracy     = UBITS(56, 1) != 0;
905
0
        ais->type19.lon          = SBITS(57, 28);
906
0
        ais->type19.lat          = SBITS(85, 27);
907
0
        ais->type19.course       = UBITS(112, 12);
908
0
        ais->type19.heading      = UBITS(124, 9);
909
0
        ais->type19.second       = UBITS(133, 6);
910
0
        ais->type19.regional     = UBITS(139, 4);
911
0
        UCHARS(143, ais->type19.shipname);
912
0
        ais->type19.shiptype     = UBITS(263, 8);
913
0
        ais->type19.to_bow       = UBITS(271, 9);
914
0
        ais->type19.to_stern     = UBITS(280, 9);
915
0
        ais->type19.to_port      = UBITS(289, 6);
916
0
        ais->type19.to_starboard = UBITS(295, 6);
917
0
        ais->type19.epfd         = UBITS(301, 4);
918
0
        ais->type19.raim         = UBITS(305, 1) != 0;
919
0
        ais->type19.dte          = UBITS(306, 1) != 0;
920
0
        ais->type19.assigned     = UBITS(307, 1) != 0;
921
        //ais->type19.spare      = UBITS(308, 4);
922
0
        break;
923
0
    case 20:    // Data Link Management Message
924
0
        RANGE_CHECK(72, 186);
925
        //ais->type20.spare     = UBITS(38, 2);
926
0
        ais->type20.offset1     = UBITS(40, 12);
927
0
        ais->type20.number1     = UBITS(52, 4);
928
0
        ais->type20.timeout1    = UBITS(56, 3);
929
0
        ais->type20.increment1  = UBITS(59, 11);
930
0
        ais->type20.offset2     = UBITS(70, 12);
931
0
        ais->type20.number2     = UBITS(82, 4);
932
0
        ais->type20.timeout2    = UBITS(86, 3);
933
0
        ais->type20.increment2  = UBITS(89, 11);
934
0
        ais->type20.offset3     = UBITS(100, 12);
935
0
        ais->type20.number3     = UBITS(112, 4);
936
0
        ais->type20.timeout3    = UBITS(116, 3);
937
0
        ais->type20.increment3  = UBITS(119, 11);
938
0
        ais->type20.offset4     = UBITS(130, 12);
939
0
        ais->type20.number4     = UBITS(142, 4);
940
0
        ais->type20.timeout4    = UBITS(146, 3);
941
0
        ais->type20.increment4  = UBITS(149, 11);
942
0
        break;
943
0
    case 21:    // Aid-to-Navigation Report
944
        // Per https://www.navcen.uscg.gov/ais-class-b-reports
945
0
        RANGE_CHECK(272, 368);
946
0
        ais->type21.aid_type     = UBITS(38, 5);
947
0
        from_sixbit_untrimmed(bits, 43, 20, ais->type21.name);
948
0
        ais->type21.accuracy     = UBITS(163, 1);
949
0
        ais->type21.lon          = SBITS(164, 28);
950
0
        ais->type21.lat          = SBITS(192, 27);
951
0
        ais->type21.to_bow       = UBITS(219, 9);
952
0
        ais->type21.to_stern     = UBITS(228, 9);
953
0
        ais->type21.to_port      = UBITS(237, 6);
954
0
        ais->type21.to_starboard = UBITS(243, 6);
955
0
        ais->type21.epfd         = UBITS(249, 4);
956
0
        ais->type21.second       = UBITS(253, 6);
957
0
        ais->type21.off_position = UBITS(259, 1)!= 0;
958
0
        ais->type21.regional     = UBITS(260, 8);
959
0
        ais->type21.raim         = UBITS(268, 1) != 0;
960
0
        ais->type21.virtual_aid  = UBITS(269, 1) != 0;
961
0
        ais->type21.assigned     = UBITS(270, 1) != 0;
962
        //ais->type21.spare      = UBITS(271, 1);
963
0
        if (20 == strnlen(ais->type21.name, 21) &&
964
0
            272 < bitlen) {
965
0
            ENDCHARS(272, ais->type21.name + 20);
966
0
        }
967
0
        trim_spaces_on_right_end(ais->type21.name, sizeof(ais->type21.name));
968
0
        break;
969
0
    case 22:    // Channel Management
970
0
        PERMISSIVE_LENGTH_CHECK(168)
971
0
        ais->type22.channel_a    = UBITS(40, 12);
972
0
        ais->type22.channel_b    = UBITS(52, 12);
973
0
        ais->type22.txrx         = UBITS(64, 4);
974
0
        ais->type22.power        = UBITS(68, 1);
975
0
        ais->type22.addressed    = UBITS(139, 1);
976
0
        if (!ais->type22.addressed) {
977
0
            ais->type22.area.ne_lon       = SBITS(69, 18);
978
0
            ais->type22.area.ne_lat       = SBITS(87, 17);
979
0
            ais->type22.area.sw_lon       = SBITS(104, 18);
980
0
            ais->type22.area.sw_lat       = SBITS(122, 17);
981
0
        } else {
982
0
            ais->type22.mmsi.dest1        = UBITS(69, 30);
983
0
            ais->type22.mmsi.dest2        = UBITS(104, 30);
984
0
        }
985
0
        ais->type22.band_a       = UBITS(140, 1);
986
0
        ais->type22.band_b       = UBITS(141, 1);
987
0
        ais->type22.zonesize     = UBITS(142, 3);
988
0
        break;
989
0
    case 23:    // Group Assignment Command
990
0
        PERMISSIVE_LENGTH_CHECK(160)
991
0
        ais->type23.ne_lon       = SBITS(40, 18);
992
0
        ais->type23.ne_lat       = SBITS(58, 17);
993
0
        ais->type23.sw_lon       = SBITS(75, 18);
994
0
        ais->type23.sw_lat       = SBITS(93, 17);
995
0
        ais->type23.stationtype  = UBITS(110, 4);
996
0
        ais->type23.shiptype     = UBITS(114, 8);
997
0
        ais->type23.txrx         = UBITS(144, 4);
998
0
        ais->type23.interval     = UBITS(146, 4);
999
0
        ais->type23.quiet        = UBITS(150, 4);
1000
0
        break;
1001
0
    case 24:    // Class B CS Static Data Report
1002
0
        switch (UBITS(38, 2)) {
1003
0
        case 0:
1004
0
            RANGE_CHECK(160, 168);
1005
            // save incoming 24A shipname/MMSI pairs in a circular queue
1006
0
            {
1007
0
                struct ais_type24a_t *saveptr =
1008
0
                        &type24_queue->ships[type24_queue->index];
1009
1010
0
                GPSD_LOG(LOG_PROG, errout, "AIVDM: 24A from %09u stashed.\n",
1011
0
                         ais->mmsi);
1012
0
                saveptr->mmsi = ais->mmsi;
1013
0
                UCHARS(40, saveptr->shipname);
1014
0
                ++type24_queue->index;
1015
0
                type24_queue->index %= MAX_TYPE24_INTERLEAVE;
1016
0
            }
1017
            //ais->type24.a.spare       = UBITS(160, 8);
1018
1019
0
            UCHARS(40, ais->type24.shipname);
1020
0
            ais->type24.part = part_a;
1021
0
            return true;
1022
0
        case 1:
1023
0
            PERMISSIVE_LENGTH_CHECK(168)
1024
0
            ais->type24.shiptype = UBITS(40, 8);
1025
            /*
1026
             * In ITU-R 1371-4, there are new model and serial fields
1027
             * carved out of the right-hand end of vendorid, which is
1028
             * reduced from 7 chars to 3.  To cope with older AIS
1029
             * implementations conforming to revision 3 and older,
1030
             * unpack the trailing bits *both* ways; truly
1031
             * revision-4-conformant implementations will have up to
1032
             * four characters of trailing garbage on the vendorid,
1033
             * and older implementations will have garbafe in the
1034
             * model and serial fields.
1035
             */
1036
0
            UCHARS(48, ais->type24.vendorid);
1037
0
            ais->type24.model = UBITS(66, 4);
1038
0
            ais->type24.serial = UBITS(70, 20);
1039
0
            UCHARS(90, ais->type24.callsign);
1040
0
            if (AIS_AUXILIARY_MMSI(ais->mmsi)) {
1041
0
                ais->type24.mothership_mmsi   = UBITS(132, 30);
1042
0
            } else {
1043
0
                ais->type24.dim.to_bow        = UBITS(132, 9);
1044
0
                ais->type24.dim.to_stern      = UBITS(141, 9);
1045
0
                ais->type24.dim.to_port       = UBITS(150, 6);
1046
0
                ais->type24.dim.to_starboard  = UBITS(156, 6);
1047
0
            }
1048
            //ais->type24.b.spare           = UBITS(162, 8);
1049
1050
            // search the 24A queue for a matching MMSI
1051
0
            for (i = 0; i < MAX_TYPE24_INTERLEAVE; i++) {
1052
0
                if (type24_queue->ships[i].mmsi == ais->mmsi) {
1053
0
                    (void)strlcpy(ais->type24.shipname,
1054
0
                                  type24_queue->ships[i].shipname,
1055
0
                                  sizeof(ais->type24.shipname));
1056
0
                    GPSD_LOG(LOG_PROG, errout,
1057
0
                             "AIVDM 24B from %09u matches a 24A.\n",
1058
0
                             ais->mmsi);
1059
                    // prevent false match if a 24B is repeated
1060
0
                    type24_queue->ships[i].mmsi = 0;
1061
0
                    ais->type24.part = both;
1062
0
                    return true;
1063
0
                }
1064
0
            }
1065
1066
            // no match, return Part B
1067
0
            ais->type24.part = part_b;
1068
0
            return true;
1069
0
        default:
1070
0
            GPSD_LOG(LOG_WARN, errout,
1071
0
                     "AIVDM message type 24 of subtype unknown.\n");
1072
0
            return false;
1073
0
        }
1074
        // break;
1075
0
    case 25:    // Binary Message, Single Slot
1076
        // this check and the following one reject line noise
1077
0
        if (40 > bitlen ||
1078
0
            168 < bitlen) {
1079
0
            GPSD_LOG(LOG_WARN, errout,
1080
0
                     "AIVDM message type 25 size not between "
1081
0
                     "40 to 168 bits (%zd).\n", bitlen);
1082
0
            return false;
1083
0
        }
1084
0
        ais->type25.addressed   = (bool)UBITS(38, 1);
1085
0
        ais->type25.structured  = (bool)UBITS(39, 1);
1086
0
        if (bitlen < (unsigned)(40 + (16 * ais->type25.structured) +
1087
0
                                (30 * ais->type25.addressed))) {
1088
0
            GPSD_LOG(LOG_WARN, errout,
1089
0
                     "AIVDM message type 25 too short for mode.\n");
1090
0
            return false;
1091
0
        }
1092
0
        if (ais->type25.addressed) {
1093
0
            ais->type25.dest_mmsi   = UBITS(40, 30);
1094
0
        }
1095
0
        if (ais->type25.structured) {
1096
0
            ais->type25.app_id      = UBITS(40 + ais->type25.addressed * 30,16);
1097
0
        }
1098
0
        ais->type25.bitcount        = bitlen - 40 - 16 * ais->type25.structured;
1099
        // bit 40 is exactly 5 bytes in; 2 bytes is 16 bits
1100
0
        (void)memcpy(ais->type25.bitdata,
1101
0
                     bits + 5 + 2 * ais->type25.structured,
1102
0
                     BITS_TO_BYTES(ais->type25.bitcount));
1103
        // discard MMSI if addressed
1104
0
        if (ais->type25.addressed) {
1105
0
            shiftleft((unsigned char *)ais->type25.bitdata,
1106
0
                      ais->type25.bitcount, 30);
1107
0
            ais->type25.bitcount -= 30;
1108
0
        }
1109
0
        break;
1110
0
    case 26:    // Binary Message, Multiple Slot
1111
0
        RANGE_CHECK(60, 1004);
1112
0
        ais->type26.addressed   = (bool)UBITS(38, 1);
1113
0
        ais->type26.structured  = (bool)UBITS(39, 1);
1114
0
        if ((signed)bitlen < 40 + 16 * ais->type26.structured +
1115
0
                30 * ais->type26.addressed + 20) {
1116
0
            GPSD_LOG(LOG_WARN, errout,
1117
0
                     "AIVDM message type 26 too short for mode.\n");
1118
0
            return false;
1119
0
        }
1120
0
        if (ais->type26.addressed) {
1121
0
            ais->type26.dest_mmsi = UBITS(40, 30);
1122
0
        }
1123
0
        if (ais->type26.structured) {
1124
0
            ais->type26.app_id    = UBITS(40 + ais->type26.addressed * 30, 16);
1125
0
        }
1126
0
        ais->type26.bitcount      = bitlen - 60 - 16 * ais->type26.structured;
1127
0
        (void)memcpy(ais->type26.bitdata,
1128
0
                     bits + 5 + 2 * ais->type26.structured,
1129
0
                     BITS_TO_BYTES(ais->type26.bitcount));
1130
        // discard MMSI if addressed
1131
0
        if (ais->type26.addressed) {
1132
0
            shiftleft((unsigned char *)ais->type26.bitdata,
1133
0
                      ais->type26.bitcount, 30);
1134
0
            ais->type26.bitcount -= 30;
1135
0
        }
1136
0
        break;
1137
0
    case 27:    // Long Range AIS Broadcast message
1138
0
        if (96 != bitlen &&
1139
0
            168 != bitlen) {
1140
0
            GPSD_LOG(LOG_WARN, errout,
1141
0
                     "unexpected AIVDM message type 27 (%zd).\n",
1142
0
                     bitlen);
1143
0
            return false;
1144
0
        }
1145
0
        if (168 == bitlen) {
1146
            /*
1147
             * This is an implementation error observed in the wild,
1148
             * sending a full 168-bit slot rather than just 96 bits.
1149
             */
1150
0
            GPSD_LOG(LOG_WARN, errout,
1151
0
                     "oversized 169=8-bit AIVDM message type 27.\n");
1152
0
        }
1153
0
        ais->type27.accuracy    = (bool)UBITS(38, 1);
1154
0
        ais->type27.raim        = UBITS(39, 1) != 0;
1155
0
        ais->type27.status      = UBITS(40, 4);
1156
0
        ais->type27.lon         = SBITS(44, 18);
1157
0
        ais->type27.lat         = SBITS(62, 17);
1158
0
        ais->type27.speed       = UBITS(79, 6);
1159
0
        ais->type27.course      = UBITS(85, 9);
1160
0
        ais->type27.gnss        = (bool)UBITS(94, 1);
1161
0
        break;
1162
0
    default:
1163
0
        GPSD_LOG(LOG_ERROR, errout,
1164
0
                 "Unparsed AIVDM message type %d.\n",ais->type);
1165
0
        return false;
1166
0
    }
1167
    // *INDENT-ON*
1168
0
#undef UCHARS
1169
0
#undef SBITS
1170
0
#undef UBITS
1171
1172
    // data is fully decoded
1173
0
    return true;
1174
0
}
1175
// vim: set expandtab shiftwidth=4