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
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
|
/****************************************************************************
NAME:
packet.c -- a packet-sniffing engine for reading from GPS devices
DESCRIPTION:
Initial conditions of the problem:
1. We have a file descriptor open for (possibly non-blocking) read. The device
on the other end is sending packets at us.
2. It may require more than one read to gather a packet. Reads may span packet
boundaries.
3. There may be leading garbage before the first packet. After the first
start-of-packet, the input should be well-formed.
The problem: how do we recognize which kind of packet we're getting?
No need to handle Garmin USB binary, we know that type by the fact we're
connected to the Garmin kernel driver. But we need to be able to tell the
others apart and distinguish them from baud barf.
PERMISSIONS
This file is Copyright (c) 2010 by the GPSD project
BSD terms apply: see the file COPYING in the distribution root for details.
***************************************************************************/
#include <sys/types.h>
#include <stdio.h>
#include <stdbool.h>
#include <ctype.h>
#include <string.h>
#include <errno.h>
#include <netinet/in.h>
#include <arpa/inet.h> /* for htons() */
#include <unistd.h>
#include "bits.h"
#include "gpsd.h"
#include "crc24q.h"
#include "strfuncs.h"
/*
* The packet-recognition state machine. This takes an incoming byte stream
* and tries to segment it into packets. There are four types of packets:
*
* 1) Comments. These begin with # and end with \r\n.
*
* 2) NMEA lines. These begin with $, and with \r\n, and have a checksum.
*
* 3) Checksummed binary packets. These begin with some fixed leader
* character(s), have a length embedded in them, and end with a
* checksum (and possibly some fixed trailing bytes).
*
* 4) ISGPS packets. The input may be a bitstream containing IS-GPS-200
* packets. Each includes a fixed leader byte, a length, and check bits.
* In this case, it is not guaranted that packet starts begin on byte
* bounaries; the recognizer has to run a separate state machine against
* each byte just to achieve synchronization lock with the bitstream.
*
* 5) Un-checksummed binary packets. Like case 3, but without
* a checksum it's much easier to get a false match from garbage.
* The packet recognizer gives checksummed types higher priority.
*
* Adding support for a new GPS protocol typically reqires adding state
* transitions to support whatever binary packet structure it has. The
* goal is for the lexer to be able to cope with arbitrarily mixed packet
* types on the input stream. This is a requirement because (1) sometimes
* gpsd wants to switch a device that supports both NMEA and a binary
* packet protocol to the latter for more detailed reporting, and (b) in
* the presence of device hotplugging, the type of GPS report coming
* in is subject to change at any time.
*
* Caller should consume a packet when it sees one of the *_RECOGNIZED
* states. It's good practice to follow the _RECOGNIZED transition
* with one that recognizes a leader of the same packet type rather
* than dropping back to ground state -- this for example will prevent
* the state machine from hopping between recognizing TSIP and
* EverMore packets that both start with a DLE.
*
* Error handling is brutally simple; any time we see an unexpected
* character, go to GROUND_STATE and reset the machine (except that a
* $ in an NMEA payload only resets back to NMEA_DOLLAR state). Because
* another good packet will usually be along in less than a second
* repeating the same data, Boyer-Moore-like attempts to do parallel
* recognition beyond the headers would make no sense in this
* application, they'd just add complexity.
*
* The NMEA portion of the state machine allows the following talker IDs:
* $GP -- Global Positioning System.
* $GL -- GLONASS, according to IEIC 61162-1
* $GN -- Mixed GPS and GLONASS data, according to IEIC 61162-1
* $BD -- Beidou
* $GB -- Beidou
* $QZ -- QZSS GPS augmentation system
* $II -- Integrated Instrumentation (Raytheon's SeaTalk system).
* $IN -- Integrated Navigation (Garmin uses this).
* $WI -- Weather instrument (Airmar PB200, Radio Ocean ROWIND, Vaisala WXT520).
* $HC -- Heading/compass (Airmar PB200).
* $TI -- Turn indicator (Airmar PB200).
* $EC -- Electronic Chart Display & Information System (ECDIS)
* $SD -- Depth Sounder
* $YX -- Transducer (used by some Airmar equipment including PB100)
* $P -- Vendor-specific sentence
*
* !AB -- NMEA 4.0 Base AIS station
* !AD -- MMEA 4.0 Dependent AIS Base Station
* !AI -- Mobile AIS station
* !AN -- NMEA 4.0 Aid to Navigation AIS station
* !AR -- NMEA 4.0 AIS Receiving Station
* !AX -- NMEA 4.0 Repeater AIS station
* !AS -- NMEA 4.0 Limited Base Station
* !AT -- NMEA 4.0 AIS Transmitting Station
* !BS -- Base AIS station (deprecated in NMEA 4.0)
* !SA -- NMEA 4.0 Physical Shore AIS Station
*/
enum
{
#include "packet_states.h"
};
static char *state_table[] = {
#include "packet_names.h"
};
#define SOH (unsigned char)0x01
#define DLE (unsigned char)0x10
#define STX (unsigned char)0x02
#define ETX (unsigned char)0x03
#ifdef ONCORE_ENABLE
static size_t oncore_payload_cksum_length(unsigned char id1, unsigned char id2)
{
size_t l;
/* For the packet sniffer to not terminate the message due to
* payload data looking like a trailer, the known payload lengths
* including the checksum are given. Return -1 for unknown IDs.
*/
#define ONCTYPE(id2,id3) ((((unsigned int)id2)<<8)|(id3))
/* *INDENT-OFF* */
switch (ONCTYPE(id1,id2)) {
case ONCTYPE('A','b'): l = 10; break; /* GMT offset */
case ONCTYPE('A','w'): l = 8; break; /* time mode */
case ONCTYPE('A','c'): l = 11; break; /* date */
case ONCTYPE('A','a'): l = 10; break; /* time of day */
case ONCTYPE('A','d'): l = 11; break; /* latitude */
case ONCTYPE('A','e'): l = 11; break; /* longitude */
case ONCTYPE('A','f'): l = 15; break; /* height */
case ONCTYPE('E','a'): l = 76; break; /* position/status/data */
case ONCTYPE('A','g'): l = 8; break; /* satellite mask angle */
case ONCTYPE('B','b'): l = 92; break; /* visible satellites status */
case ONCTYPE('B','j'): l = 8; break; /* leap seconds pending */
case ONCTYPE('A','q'): l = 8; break; /* atmospheric correction mode */
case ONCTYPE('A','p'): l = 25; break; /* set user datum / select datum */
/* Command "Ao" gives "Ap" response (select datum) */
case ONCTYPE('C','h'): l = 9; break; /* almanac input ("Cb" response) */
case ONCTYPE('C','b'): l = 33; break; /* almanac output ("Be" response) */
case ONCTYPE('S','z'): l = 8; break; /* system power-on failure */
case ONCTYPE('C','j'): l = 294; break; /* receiver ID */
case ONCTYPE('F','a'): l = 9; break; /* self-test */
case ONCTYPE('C','f'): l = 7; break; /* set-to-defaults */
case ONCTYPE('E','q'): l = 96; break; /* ASCII position */
case ONCTYPE('A','u'): l = 12; break; /* altitide hold height */
case ONCTYPE('A','v'): l = 8; break; /* altitude hold mode */
case ONCTYPE('A','N'): l = 8; break; /* velocity filter */
case ONCTYPE('A','O'): l = 8; break; /* RTCM report mode */
case ONCTYPE('C','c'): l = 80; break; /* ephemeris data input ("Bf") */
case ONCTYPE('C','k'): l = 7; break; /* pseudorng correction inp. ("Ce")*/
/* Command "Ci" (switch to NMEA, GT versions only) has no response */
case ONCTYPE('B','o'): l = 8; break; /* UTC offset status */
case ONCTYPE('A','z'): l = 11; break; /* 1PPS cable delay */
case ONCTYPE('A','y'): l = 11; break; /* 1PPS offset */
case ONCTYPE('A','P'): l = 8; break; /* pulse mode */
case ONCTYPE('A','s'): l = 20; break; /* position-hold position */
case ONCTYPE('A','t'): l = 8; break; /* position-hold mode */
case ONCTYPE('E','n'): l = 69; break; /* time RAIM setup and status */
default:
return 0;
}
/* *INDENT-ON* */
return l - 6; /* Subtract header and trailer. */
}
#endif /* ONCORE_ENABLE */
static bool character_pushback(struct gps_lexer_t *lexer, unsigned int newstate)
/* push back the last character grabbed, setting a specified state */
{
--lexer->inbufptr;
--lexer->char_counter;
lexer->state = newstate;
if (lexer->errout.debug >= LOG_RAW + 2)
{
unsigned char c = *lexer->inbufptr;
gpsd_log(&lexer->errout, LOG_RAW + 2,
"%08ld: character '%c' [%02x] pushed back, state set to %s\n",
lexer->char_counter,
(isprint((int)c) ? c : '.'), c,
state_table[lexer->state]);
}
return false;
}
static bool nextstate(struct gps_lexer_t *lexer, unsigned char c)
{
static int n = 0;
#ifdef RTCM104V2_ENABLE
enum isgpsstat_t isgpsstat;
#endif /* RTCM104V2_ENABLE */
#ifdef SUPERSTAR2_ENABLE
static unsigned char ctmp;
#endif /* SUPERSTAR2_ENABLE */
n++;
switch (lexer->state) {
case GROUND_STATE:
n = 0;
#ifdef STASH_ENABLE
lexer->stashbuflen = 0;
#endif
if (c == '#') {
lexer->state = COMMENT_BODY;
break;
}
#ifdef NMEA0183_ENABLE
if (c == '$') {
lexer->state = NMEA_DOLLAR;
break;
}
if (c == '!') {
lexer->state = NMEA_BANG;
break;
}
#endif /* NMEA0183_ENABLE */
#if defined(TNT_ENABLE) || defined(GARMINTXT_ENABLE) || defined(ONCORE_ENABLE)
if (c == '@') {
#ifdef RTCM104V2_ENABLE
if (rtcm2_decode(lexer, c) == ISGPS_MESSAGE) {
lexer->state = RTCM2_RECOGNIZED;
break;
}
#endif /* RTCM104V2_ENABLE */
lexer->state = AT1_LEADER;
break;
}
#endif
#if defined(SIRF_ENABLE) || defined(SKYTRAQ_ENABLE)
if (c == 0xa0) {
lexer->state = SIRF_LEADER_1;
break;
}
#endif /* SIRF_ENABLE || SKYTRAQ_ENABLE */
#ifdef SUPERSTAR2_ENABLE
if (c == SOH) {
lexer->state = SUPERSTAR2_LEADER;
break;
}
#endif /* SUPERSTAR2_ENABLE */
#if defined(TSIP_ENABLE) || defined(EVERMORE_ENABLE) || defined(GARMIN_ENABLE)
if (c == DLE) {
lexer->state = DLE_LEADER;
break;
}
#endif /* TSIP_ENABLE || EVERMORE_ENABLE || GARMIN_ENABLE */
#ifdef TRIPMATE_ENABLE
if (c == 'A') {
#ifdef RTCM104V2_ENABLE
if (rtcm2_decode(lexer, c) == ISGPS_MESSAGE) {
lexer->state = RTCM2_RECOGNIZED;
break;
}
#endif /* RTCM104V2_ENABLE */
lexer->state = ASTRAL_1;
break;
}
#endif /* TRIPMATE_ENABLE */
#ifdef EARTHMATE_ENABLE
if (c == 'E') {
#ifdef RTCM104V2_ENABLE
if (rtcm2_decode(lexer, c) == ISGPS_MESSAGE) {
lexer->state = RTCM2_RECOGNIZED;
break;
}
#endif /* RTCM104V2_ENABLE */
lexer->state = EARTHA_1;
break;
}
#endif /* EARTHMATE_ENABLE */
#ifdef ZODIAC_ENABLE
if (c == 0xff) {
lexer->state = ZODIAC_LEADER_1;
break;
}
#endif /* ZODIAC_ENABLE */
#ifdef UBLOX_ENABLE
if (c == 0xb5) {
lexer->state = UBX_LEADER_1;
break;
}
#endif /* UBLOX_ENABLE */
#ifdef ITRAX_ENABLE
if (c == '<') {
lexer->state = ITALK_LEADER_1;
break;
}
#endif /* ITRAX_ENABLE */
#ifdef NAVCOM_ENABLE
if (c == 0x02) {
lexer->state = NAVCOM_LEADER_1;
break;
}
#endif /* NAVCOM_ENABLE */
#ifdef GEOSTAR_ENABLE
if (c == 'P') {
lexer->state = GEOSTAR_LEADER_1;
break;
}
#endif /* GEOSTAR_ENABLE */
#ifdef RTCM104V2_ENABLE
if ((isgpsstat = rtcm2_decode(lexer, c)) == ISGPS_SYNC) {
lexer->state = RTCM2_SYNC_STATE;
break;
} else if (isgpsstat == ISGPS_MESSAGE) {
lexer->state = RTCM2_RECOGNIZED;
break;
}
#endif /* RTCM104V2_ENABLE */
#ifdef RTCM104V3_ENABLE
if (c == 0xD3) {
lexer->state = RTCM3_LEADER_1;
break;
}
#endif /* RTCM104V3_ENABLE */
#ifdef PASSTHROUGH_ENABLE
if (c == '{')
return character_pushback(lexer, JSON_LEADER);
#endif /* PASSTHROUGH_ENABLE */
break;
case COMMENT_BODY:
if (c == '\n')
lexer->state = COMMENT_RECOGNIZED;
else if (!isprint(c))
return character_pushback(lexer, GROUND_STATE);
break;
#ifdef NMEA0183_ENABLE
case NMEA_DOLLAR:
if (c == 'G')
lexer->state = NMEA_PUB_LEAD;
else if (c == 'P') /* vendor sentence */
lexer->state = NMEA_VENDOR_LEAD;
else if (c == 'I') /* Seatalk */
lexer->state = SEATALK_LEAD_1;
else if (c == 'W') /* Weather instrument */
lexer->state = WEATHER_LEAD_1;
else if (c == 'H') /* Heading/compass */
lexer->state = HEADCOMP_LEAD_1;
else if (c == 'T') /* Turn indicator */
lexer->state = TURN_LEAD_1;
else if (c == 'A') /* SiRF Ack */
lexer->state = SIRF_ACK_LEAD_1;
else if (c == 'E') /* ECDIS */
lexer->state = ECDIS_LEAD_1;
else if (c == 'S')
lexer->state = SOUNDER_LEAD_1;
else if (c == 'Y')
lexer->state = TRANSDUCER_LEAD_1;
else if (c == 'B')
lexer->state = BEIDOU_LEAD_1;
else if (c == 'Q')
lexer->state = QZSS_LEAD_1;
#ifdef OCEANSERVER_ENABLE
else if (c == 'C')
lexer->state = NMEA_LEADER_END;
#endif /* OCEANSERVER_ENABLE */
else
(void) character_pushback(lexer, GROUND_STATE);
break;
case NMEA_PUB_LEAD:
/*
* $GP == GPS, $GL = GLONASS only, $GN = mixed GPS and GLONASS,
* according to NMEA (IEIC 61162-1) DRAFT 02/06/2009.
* We have a log from China with a Beidou device using $GB
* rather than $BD.
*/
if (c == 'B' || c == 'P' || c == 'N' || c == 'L')
lexer->state = NMEA_LEADER_END;
else
(void) character_pushback(lexer, GROUND_STATE);
break;
case NMEA_VENDOR_LEAD:
if (c == 'A')
lexer->state = NMEA_PASHR_A;
else if (isalpha(c))
lexer->state = NMEA_LEADER_END;
else
(void) character_pushback(lexer, GROUND_STATE);
break;
/*
* Without the following six states, DLE in a $PASHR can fool the
* sniffer into thinking it sees a TSIP packet. Hilarity ensues.
*/
case NMEA_PASHR_A:
if (c == 'S')
lexer->state = NMEA_PASHR_S;
else if (isalpha(c))
lexer->state = NMEA_LEADER_END;
else
(void) character_pushback(lexer, GROUND_STATE);
break;
case NMEA_PASHR_S:
if (c == 'H')
lexer->state = NMEA_PASHR_H;
else if (isalpha(c))
lexer->state = NMEA_LEADER_END;
else
(void) character_pushback(lexer, GROUND_STATE);
break;
case NMEA_PASHR_H:
if (c == 'R')
lexer->state = NMEA_BINARY_BODY;
else if (isalpha(c))
lexer->state = NMEA_LEADER_END;
else
(void) character_pushback(lexer, GROUND_STATE);
break;
case NMEA_BINARY_BODY:
if (c == '\r')
lexer->state = NMEA_BINARY_CR;
break;
case NMEA_BINARY_CR:
if (c == '\n')
lexer->state = NMEA_BINARY_NL;
else
lexer->state = NMEA_BINARY_BODY;
break;
case NMEA_BINARY_NL:
if (c == '$')
(void) character_pushback(lexer, NMEA_RECOGNIZED);
else
lexer->state = NMEA_BINARY_BODY;
break;
case NMEA_BANG:
if (c == 'A')
lexer->state = AIS_LEAD_1;
else if (c == 'B')
lexer->state = AIS_LEAD_ALT1;
else if (c == 'S')
lexer->state = AIS_LEAD_ALT3;
else
return character_pushback(lexer, GROUND_STATE);
break;
case AIS_LEAD_1:
if (strchr("BDINRSTX", c) != NULL)
lexer->state = AIS_LEAD_2;
else
return character_pushback(lexer, GROUND_STATE);
break;
case AIS_LEAD_2:
if (isalpha(c))
lexer->state = NMEA_LEADER_END;
else
return character_pushback(lexer, GROUND_STATE);
break;
case AIS_LEAD_ALT1:
if (c == 'S')
lexer->state = AIS_LEAD_ALT2;
else
return character_pushback(lexer, GROUND_STATE);
break;
case AIS_LEAD_ALT2:
if (isalpha(c))
lexer->state = NMEA_LEADER_END;
else
return character_pushback(lexer, GROUND_STATE);
break;
case AIS_LEAD_ALT3:
if (c == 'A')
lexer->state = AIS_LEAD_ALT4;
else
return character_pushback(lexer, GROUND_STATE);
break;
case AIS_LEAD_ALT4:
if (isalpha(c))
lexer->state = NMEA_LEADER_END;
else
return character_pushback(lexer, GROUND_STATE);
break;
#if defined(TNT_ENABLE) || defined(GARMINTXT_ENABLE) || defined(ONCORE_ENABLE)
case AT1_LEADER:
switch (c) {
#ifdef ONCORE_ENABLE
case '@':
lexer->state = ONCORE_AT2;
break;
#endif /* ONCORE_ENABLE */
#ifdef TNT_ENABLE
case '*':
/*
* TNT has similar structure to NMEA packet, '*' before
* optional checksum ends the packet. Since '*' cannot be
* received from GARMIN working in TEXT mode, use this
* difference to tell that this is not GARMIN TEXT packet,
* could be TNT.
*/
lexer->state = NMEA_LEADER_END;
break;
#endif /* TNT_ENABLE */
#if defined(GARMINTXT_ENABLE)
case '\r':
/* stay in this state, next character should be '\n' */
/* in the theory we can stop search here and don't wait for '\n' */
lexer->state = AT1_LEADER;
break;
case '\n':
/* end of packet found */
lexer->state = GTXT_RECOGNIZED;
break;
#endif /* GARMINTXT_ENABLE */
default:
if (!isprint(c))
return character_pushback(lexer, GROUND_STATE);
}
break;
#endif /* defined(TNT_ENABLE) || defined(GARMINTXT_ENABLE) || defined(ONCORE_ENABLE) */
case NMEA_LEADER_END:
if (c == '\r')
lexer->state = NMEA_CR;
else if (c == '\n')
/* not strictly correct, but helps for interpreting logfiles */
lexer->state = NMEA_RECOGNIZED;
else if (c == '$') {
#ifdef STASH_ENABLE
(void) character_pushback(lexer, STASH_RECOGNIZED);
#else
(void) character_pushback(lexer, GROUND_STATE);
#endif
} else if (!isprint(c))
(void) character_pushback(lexer, GROUND_STATE);
break;
case NMEA_CR:
if (c == '\n')
lexer->state = NMEA_RECOGNIZED;
/*
* There's a GPS called a Jackson Labs Firefly-1a that emits \r\r\n
* at the end of each sentence. Don't be confused by this.
*/
else if (c == '\r')
lexer->state = NMEA_CR;
else
(void) character_pushback(lexer, GROUND_STATE);
break;
case NMEA_RECOGNIZED:
if (c == '#')
lexer->state = COMMENT_BODY;
else if (c == '$')
lexer->state = NMEA_DOLLAR;
else if (c == '!')
lexer->state = NMEA_BANG;
#ifdef UBLOX_ENABLE
else if (c == 0xb5) /* LEA-5H can and will output NMEA and UBX back to back */
lexer->state = UBX_LEADER_1;
#endif
#ifdef PASSTHROUGH_ENABLE
else if (c == '{')
return character_pushback(lexer, JSON_LEADER);
#endif /* PASSTHROUGH_ENABLE */
else
return character_pushback(lexer, GROUND_STATE);
break;
case SEATALK_LEAD_1:
if (c == 'I' || c == 'N') /* II or IN are accepted */
lexer->state = NMEA_LEADER_END;
else
return character_pushback(lexer, GROUND_STATE);
break;
case WEATHER_LEAD_1:
if (c == 'I') /* Weather instrument leader accepted */
lexer->state = NMEA_LEADER_END;
else
return character_pushback(lexer, GROUND_STATE);
break;
case HEADCOMP_LEAD_1:
if (c == 'C') /* Heading/compass leader accepted */
lexer->state = NMEA_LEADER_END;
else
return character_pushback(lexer, GROUND_STATE);
break;
case TURN_LEAD_1:
if (c == 'I') /* Turn indicator leader accepted */
lexer->state = NMEA_LEADER_END;
else
return character_pushback(lexer, GROUND_STATE);
break;
case ECDIS_LEAD_1:
if (c == 'C') /* ECDIS leader accepted */
lexer->state = NMEA_LEADER_END;
else
return character_pushback(lexer, GROUND_STATE);
break;
case SOUNDER_LEAD_1:
if (c == 'D') /* Depth-sounder leader accepted */
lexer->state = NMEA_LEADER_END;
else
return character_pushback(lexer, GROUND_STATE);
break;
case TRANSDUCER_LEAD_1:
if (c == 'X') /* Transducer leader accepted */
lexer->state = NMEA_LEADER_END;
else
return character_pushback(lexer, GROUND_STATE);
break;
case BEIDOU_LEAD_1:
if (c == 'D') /* Beidou leader accepted */
lexer->state = NMEA_LEADER_END;
else
return character_pushback(lexer, GROUND_STATE);
break;
case QZSS_LEAD_1:
if (c == 'Z') /* QZSS leader accepted */
lexer->state = NMEA_LEADER_END;
else
return character_pushback(lexer, GROUND_STATE);
break;
#ifdef TRIPMATE_ENABLE
case ASTRAL_1:
if (c == 'S') {
#ifdef RTCM104V2_ENABLE
if ((isgpsstat = rtcm2_decode(lexer, c)) == ISGPS_SYNC) {
lexer->state = RTCM2_SYNC_STATE;
break;
} else if (isgpsstat == ISGPS_MESSAGE) {
lexer->state = RTCM2_RECOGNIZED;
break;
}
#endif /* RTCM104V2_ENABLE */
lexer->state = ASTRAL_2;
} else
(void) character_pushback(lexer, GROUND_STATE);
break;
case ASTRAL_2:
if (c == 'T') {
#ifdef RTCM104V2_ENABLE
if ((isgpsstat = rtcm2_decode(lexer, c)) == ISGPS_SYNC) {
lexer->state = RTCM2_SYNC_STATE;
break;
} else if (isgpsstat == ISGPS_MESSAGE) {
lexer->state = RTCM2_RECOGNIZED;
break;
}
#endif /* RTCM104V2_ENABLE */
lexer->state = ASTRAL_3;
} else
(void) character_pushback(lexer, GROUND_STATE);
break;
case ASTRAL_3:
if (c == 'R') {
#ifdef RTCM104V2_ENABLE
if ((isgpsstat = rtcm2_decode(lexer, c)) == ISGPS_SYNC) {
lexer->state = RTCM2_SYNC_STATE;
break;
} else if (isgpsstat == ISGPS_MESSAGE) {
lexer->state = RTCM2_RECOGNIZED;
break;
}
#endif /* RTCM104V2_ENABLE */
lexer->state = ASTRAL_5;
} else
(void) character_pushback(lexer, GROUND_STATE);
break;
case ASTRAL_4:
if (c == 'A') {
#ifdef RTCM104V2_ENABLE
if ((isgpsstat = rtcm2_decode(lexer, c)) == ISGPS_SYNC) {
lexer->state = RTCM2_SYNC_STATE;
break;
} else if (isgpsstat == ISGPS_MESSAGE) {
lexer->state = RTCM2_RECOGNIZED;
break;
}
#endif /* RTCM104V2_ENABLE */
lexer->state = ASTRAL_2;
} else
(void) character_pushback(lexer, GROUND_STATE);
break;
case ASTRAL_5:
if (c == 'L') {
#ifdef RTCM104V2_ENABLE
if ((isgpsstat = rtcm2_decode(lexer, c)) == ISGPS_SYNC) {
lexer->state = RTCM2_SYNC_STATE;
break;
} else if (isgpsstat == ISGPS_MESSAGE) {
lexer->state = RTCM2_RECOGNIZED;
break;
}
#endif /* RTCM104V2_ENABLE */
lexer->state = NMEA_RECOGNIZED;
} else
(void) character_pushback(lexer, GROUND_STATE);
break;
#endif /* TRIPMATE_ENABLE */
#ifdef EARTHMATE_ENABLE
case EARTHA_1:
if (c == 'A') {
#ifdef RTCM104V2_ENABLE
if ((isgpsstat = rtcm2_decode(lexer, c)) == ISGPS_SYNC) {
lexer->state = RTCM2_SYNC_STATE;
break;
} else if (isgpsstat == ISGPS_MESSAGE) {
lexer->state = RTCM2_RECOGNIZED;
break;
}
#endif /* RTCM104V2_ENABLE */
lexer->state = EARTHA_2;
} else
(void) character_pushback(lexer, GROUND_STATE);
break;
case EARTHA_2:
if (c == 'R') {
#ifdef RTCM104V2_ENABLE
if ((isgpsstat = rtcm2_decode(lexer, c)) == ISGPS_SYNC) {
lexer->state = RTCM2_SYNC_STATE;
break;
} else if (isgpsstat == ISGPS_MESSAGE) {
lexer->state = RTCM2_RECOGNIZED;
break;
}
#endif /* RTCM104V2_ENABLE */
lexer->state = EARTHA_3;
} else
(void) character_pushback(lexer, GROUND_STATE);
break;
case EARTHA_3:
if (c == 'T') {
#ifdef RTCM104V2_ENABLE
if ((isgpsstat = rtcm2_decode(lexer, c)) == ISGPS_SYNC) {
lexer->state = RTCM2_SYNC_STATE;
break;
} else if (isgpsstat == ISGPS_MESSAGE) {
lexer->state = RTCM2_RECOGNIZED;
break;
}
#endif /* RTCM104V2_ENABLE */
lexer->state = EARTHA_4;
} else
(void) character_pushback(lexer, GROUND_STATE);
break;
case EARTHA_4:
if (c == 'H') {
#ifdef RTCM104V2_ENABLE
if ((isgpsstat = rtcm2_decode(lexer, c)) == ISGPS_SYNC) {
lexer->state = RTCM2_SYNC_STATE;
break;
} else if (isgpsstat == ISGPS_MESSAGE) {
lexer->state = RTCM2_RECOGNIZED;
break;
}
#endif /* RTCM104V2_ENABLE */
lexer->state = EARTHA_5;
} else
(void) character_pushback(lexer, GROUND_STATE);
break;
case EARTHA_5:
if (c == 'A') {
#ifdef RTCM104V2_ENABLE
if ((isgpsstat = rtcm2_decode(lexer, c)) == ISGPS_SYNC) {
lexer->state = RTCM2_SYNC_STATE;
break;
} else if (isgpsstat == ISGPS_MESSAGE) {
lexer->state = RTCM2_RECOGNIZED;
break;
}
#endif /* RTCM104V2_ENABLE */
lexer->state = NMEA_RECOGNIZED;
} else
(void) character_pushback(lexer, GROUND_STATE);
break;
#endif /* EARTHMATE_ENABLE */
case SIRF_ACK_LEAD_1:
if (c == 'c')
lexer->state = SIRF_ACK_LEAD_2;
else if (c == 'I')
lexer->state = AIS_LEAD_2;
else
return character_pushback(lexer, GROUND_STATE);
break;
case SIRF_ACK_LEAD_2:
if (c == 'k')
lexer->state = NMEA_LEADER_END;
else
return character_pushback(lexer, GROUND_STATE);
break;
#endif /* NMEA0183_ENABLE */
#if defined(SIRF_ENABLE) || defined(SKYTRAQ_ENABLE)
case SIRF_LEADER_1:
# ifdef SIRF_ENABLE
/* SIRF leads with 0xA0,0xA2 */
if (c == 0xa2)
lexer->state = SIRF_LEADER_2;
else
# endif /* SIRF_ENABLE */
# ifdef SKYTRAQ_ENABLE
/* Skytraq leads with 0xA0,0xA1 */
if (c == 0xa1)
lexer->state = SKY_LEADER_2;
else
# endif /* SKYTRAQ_ENABLE */
return character_pushback(lexer, GROUND_STATE);
break;
#endif /* SIRF_ENABLE || SKYTRAQ_ENABLE */
#ifdef SIRF_ENABLE
case SIRF_LEADER_2:
lexer->length = (size_t) (c << 8);
lexer->state = SIRF_LENGTH_1;
break;
case SIRF_LENGTH_1:
lexer->length += c + 2;
if (lexer->length <= MAX_PACKET_LENGTH)
lexer->state = SIRF_PAYLOAD;
else
return character_pushback(lexer, GROUND_STATE);
break;
case SIRF_PAYLOAD:
if (--lexer->length == 0)
lexer->state = SIRF_DELIVERED;
break;
case SIRF_DELIVERED:
if (c == 0xb0)
lexer->state = SIRF_TRAILER_1;
else
return character_pushback(lexer, GROUND_STATE);
break;
case SIRF_TRAILER_1:
if (c == 0xb3)
lexer->state = SIRF_RECOGNIZED;
else
return character_pushback(lexer, GROUND_STATE);
break;
case SIRF_RECOGNIZED:
if (c == 0xa0)
lexer->state = SIRF_LEADER_1;
else
return character_pushback(lexer, GROUND_STATE);
break;
#endif /* SIRF_ENABLE */
#ifdef SKYTRAQ_ENABLE
case SKY_LEADER_2:
/* MSB of length is first */
lexer->length = (size_t) (c << 8);
lexer->state = SKY_LENGTH_1;
break;
case SKY_LENGTH_1:
/* Skytraq length can be any 16 bit number, except 0 */
lexer->length += c;
if ( 0 == lexer->length )
return character_pushback(lexer, GROUND_STATE);
if (lexer->length > MAX_PACKET_LENGTH)
return character_pushback(lexer, GROUND_STATE);
lexer->state = SKY_PAYLOAD;
break;
case SKY_PAYLOAD:
if ( 00 == --lexer->length)
lexer->state = SKY_DELIVERED;
break;
case SKY_DELIVERED:
if ( lexer->errout.debug >= LOG_RAW+1) {
char scratchbuf[MAX_PACKET_LENGTH*2+1];
gpsd_log(&lexer->errout, LOG_RAW+1,
"Skytraq = %s\n",
gpsd_packetdump(scratchbuf, sizeof(scratchbuf),
(char *)lexer->inbuffer,
lexer->inbufptr - (unsigned char *)lexer->inbuffer));
}
{
unsigned char csum = 0;
for (n = 4;
(unsigned char *)(lexer->inbuffer + n) < lexer->inbufptr - 1;
n++)
csum ^= lexer->inbuffer[n];
if (csum != c) {
gpsd_log(&lexer->errout, LOG_IO,
"Skytraq bad checksum 0x%hhx, expecting 0x%x\n",
csum, c);
lexer->state = GROUND_STATE;
break;
}
}
lexer->state = SKY_CSUM;
break;
case SKY_CSUM:
if ( 0x0d != c)
return character_pushback(lexer, GROUND_STATE);
lexer->state = SKY_TRAILER_1;
break;
case SKY_TRAILER_1:
if ( 0x0a != c)
return character_pushback(lexer, GROUND_STATE);
lexer->state = SKY_RECOGNIZED;
break;
case SKY_RECOGNIZED:
if ( 0xa0 != c)
return character_pushback(lexer, GROUND_STATE);
lexer->state = SIRF_LEADER_1;
break;
#endif /* SKYTRAQ */
#ifdef SUPERSTAR2_ENABLE
case SUPERSTAR2_LEADER:
ctmp = c;
lexer->state = SUPERSTAR2_ID1;
break;
case SUPERSTAR2_ID1:
if ((ctmp ^ 0xff) == c)
lexer->state = SUPERSTAR2_ID2;
else
return character_pushback(lexer, GROUND_STATE);
break;
case SUPERSTAR2_ID2:
lexer->length = (size_t) c; /* how many data bytes follow this byte */
if (lexer->length)
lexer->state = SUPERSTAR2_PAYLOAD;
else
lexer->state = SUPERSTAR2_CKSUM1; /* no data, jump to checksum */
break;
case SUPERSTAR2_PAYLOAD:
if (--lexer->length == 0)
lexer->state = SUPERSTAR2_CKSUM1;
break;
case SUPERSTAR2_CKSUM1:
lexer->state = SUPERSTAR2_CKSUM2;
break;
case SUPERSTAR2_CKSUM2:
lexer->state = SUPERSTAR2_RECOGNIZED;
break;
case SUPERSTAR2_RECOGNIZED:
if (c == SOH)
lexer->state = SUPERSTAR2_LEADER;
else
return character_pushback(lexer, GROUND_STATE);
break;
#endif /* SUPERSTAR2_ENABLE */
#ifdef ONCORE_ENABLE
case ONCORE_AT2:
if (isupper(c)) {
lexer->length = (size_t) c;
lexer->state = ONCORE_ID1;
} else
return character_pushback(lexer, GROUND_STATE);
break;
case ONCORE_ID1:
if (isalpha(c)) {
lexer->length =
oncore_payload_cksum_length((unsigned char)lexer->length, c);
if (lexer->length != 0) {
lexer->state = ONCORE_PAYLOAD;
break;
}
} else
return character_pushback(lexer, GROUND_STATE);
break;
case ONCORE_PAYLOAD:
if (--lexer->length == 0)
lexer->state = ONCORE_CHECKSUM;
break;
case ONCORE_CHECKSUM:
if (c != '\r')
return character_pushback(lexer, GROUND_STATE);
else
lexer->state = ONCORE_CR;
break;
case ONCORE_CR:
if (c == '\n')
lexer->state = ONCORE_RECOGNIZED;
else
lexer->state = ONCORE_PAYLOAD;
break;
case ONCORE_RECOGNIZED:
if (c == '@')
lexer->state = AT1_LEADER;
else
return character_pushback(lexer, GROUND_STATE);
break;
#endif /* ONCORE_ENABLE */
#if defined(TSIP_ENABLE) || defined(EVERMORE_ENABLE) || defined(GARMIN_ENABLE)
case DLE_LEADER:
#ifdef EVERMORE_ENABLE
if (c == STX) {
lexer->state = EVERMORE_LEADER_2;
break;
}
#endif /* EVERMORE_ENABLE */
#if defined(TSIP_ENABLE) || defined(GARMIN_ENABLE) || defined(NAVCOM_ENABLE)
/* garmin is special case of TSIP */
/* check last because there's no checksum */
#if defined(TSIP_ENABLE)
if (c >= 0x13) {
lexer->state = TSIP_PAYLOAD;
break;
}
#endif /* TSIP_ENABLE */
if (c == DLE) {
lexer->state = GROUND_STATE;
break;
}
// FALL-THRU!!!!! no break here
#endif /* TSIP_ENABLE */
#ifdef NAVCOM_ENABLE
case NAVCOM_LEADER_1:
if (c == 0x99)
lexer->state = NAVCOM_LEADER_2;
else
return character_pushback(lexer, GROUND_STATE);
break;
case NAVCOM_LEADER_2:
if (c == 0x66)
lexer->state = NAVCOM_LEADER_3;
else
return character_pushback(lexer, GROUND_STATE);
break;
case NAVCOM_LEADER_3:
lexer->state = NAVCOM_ID;
break;
case NAVCOM_ID:
lexer->length = (size_t) c - 4;
lexer->state = NAVCOM_LENGTH_1;
break;
case NAVCOM_LENGTH_1:
lexer->length += (c << 8);
lexer->state = NAVCOM_LENGTH_2;
break;
case NAVCOM_LENGTH_2:
if (--lexer->length == 0)
lexer->state = NAVCOM_PAYLOAD;
break;
case NAVCOM_PAYLOAD:
{
unsigned char csum = lexer->inbuffer[3];
for (n = 4;
(unsigned char *)(lexer->inbuffer + n) < lexer->inbufptr - 1;
n++)
csum ^= lexer->inbuffer[n];
if (csum != c) {
gpsd_log(&lexer->errout, LOG_IO,
"Navcom packet type 0x%hhx bad checksum 0x%hhx, expecting 0x%x\n",
lexer->inbuffer[3], csum, c);
lexer->state = GROUND_STATE;
break;
}
}
lexer->state = NAVCOM_CSUM;
break;
case NAVCOM_CSUM:
if (c == 0x03)
lexer->state = NAVCOM_RECOGNIZED;
else
return character_pushback(lexer, GROUND_STATE);
break;
case NAVCOM_RECOGNIZED:
if (c == 0x02)
lexer->state = NAVCOM_LEADER_1;
else
return character_pushback(lexer, GROUND_STATE);
break;
#endif /* NAVCOM_ENABLE */
#endif /* TSIP_ENABLE || EVERMORE_ENABLE || GARMIN_ENABLE */
#ifdef RTCM104V3_ENABLE
case RTCM3_LEADER_1:
/* high 6 bits must be zero, low 2 bits are MSB of a 10-bit length */
if ((c & 0xFC) == 0) {
lexer->length = (size_t) (c << 8);
lexer->state = RTCM3_LEADER_2;
} else
return character_pushback(lexer, GROUND_STATE);
break;
case RTCM3_LEADER_2:
/* third byte is the low 8 bits of the RTCM3 packet length */
lexer->length |= c;
lexer->length += 3; /* to get the three checksum bytes */
lexer->state = RTCM3_PAYLOAD;
break;
case RTCM3_PAYLOAD:
if (--lexer->length == 0)
lexer->state = RTCM3_RECOGNIZED;
break;
#endif /* RTCM104V3_ENABLE */
#ifdef ZODIAC_ENABLE
case ZODIAC_EXPECTED:
case ZODIAC_RECOGNIZED:
if (c == 0xff)
lexer->state = ZODIAC_LEADER_1;
else
return character_pushback(lexer, GROUND_STATE);
break;
case ZODIAC_LEADER_1:
if (c == 0x81)
lexer->state = ZODIAC_LEADER_2;
else
return character_pushback(lexer, GROUND_STATE);
break;
case ZODIAC_LEADER_2:
lexer->state = ZODIAC_ID_1;
break;
case ZODIAC_ID_1:
lexer->state = ZODIAC_ID_2;
break;
case ZODIAC_ID_2:
lexer->length = (size_t) c;
lexer->state = ZODIAC_LENGTH_1;
break;
case ZODIAC_LENGTH_1:
lexer->length += (c << 8);
lexer->state = ZODIAC_LENGTH_2;
break;
case ZODIAC_LENGTH_2:
lexer->state = ZODIAC_FLAGS_1;
break;
case ZODIAC_FLAGS_1:
lexer->state = ZODIAC_FLAGS_2;
break;
case ZODIAC_FLAGS_2:
lexer->state = ZODIAC_HSUM_1;
break;
case ZODIAC_HSUM_1:
{
#define getword(i) (short)(lexer->inbuffer[2*(i)] | (lexer->inbuffer[2*(i)+1] << 8))
short sum = getword(0) + getword(1) + getword(2) + getword(3);
sum *= -1;
if (sum != getword(4)) {
gpsd_log(&lexer->errout, LOG_IO,
"Zodiac Header checksum 0x%hx expecting 0x%hx\n",
sum, getword(4));
lexer->state = GROUND_STATE;
break;
}
}
gpsd_log(&lexer->errout, LOG_RAW + 1,
"Zodiac header id=%hd len=%hd flags=%hx\n",
getword(1), getword(2), getword(3));
#undef getword
if (lexer->length == 0) {
lexer->state = ZODIAC_RECOGNIZED;
break;
}
lexer->length *= 2; /* word count to byte count */
lexer->length += 2; /* checksum */
/* 10 bytes is the length of the Zodiac header */
if (lexer->length <= MAX_PACKET_LENGTH - 10)
lexer->state = ZODIAC_PAYLOAD;
else
return character_pushback(lexer, GROUND_STATE);
break;
case ZODIAC_PAYLOAD:
if (--lexer->length == 0)
lexer->state = ZODIAC_RECOGNIZED;
break;
#endif /* ZODIAC_ENABLE */
#ifdef UBLOX_ENABLE
case UBX_LEADER_1:
if (c == 0x62)
lexer->state = UBX_LEADER_2;
else
return character_pushback(lexer, GROUND_STATE);
break;
case UBX_LEADER_2:
lexer->state = UBX_CLASS_ID;
break;
case UBX_CLASS_ID:
lexer->state = UBX_MESSAGE_ID;
break;
case UBX_MESSAGE_ID:
lexer->length = (size_t) c;
lexer->state = UBX_LENGTH_1;
break;
case UBX_LENGTH_1:
lexer->length += (c << 8);
if (lexer->length <= MAX_PACKET_LENGTH)
lexer->state = UBX_LENGTH_2;
else
return character_pushback(lexer, GROUND_STATE);
break;
case UBX_LENGTH_2:
lexer->state = UBX_PAYLOAD;
break;
case UBX_PAYLOAD:
if (--lexer->length == 0)
lexer->state = UBX_CHECKSUM_A;
/* else stay in payload state */
break;
case UBX_CHECKSUM_A:
lexer->state = UBX_RECOGNIZED;
break;
case UBX_RECOGNIZED:
if (c == 0xb5)
lexer->state = UBX_LEADER_1;
#ifdef NMEA0183_ENABLE
else if (c == '$') /* LEA-5H can and will output NMEA and UBX back to back */
lexer->state = NMEA_DOLLAR;
#endif /* NMEA0183_ENABLE */
#ifdef PASSTHROUGH_ENABLE
else if (c == '{')
return character_pushback(lexer, JSON_LEADER);
#endif /* PASSTHROUGH_ENABLE */
else
return character_pushback(lexer, GROUND_STATE);
break;
#endif /* UBLOX_ENABLE */
#ifdef EVERMORE_ENABLE
case EVERMORE_LEADER_1:
if (c == STX)
lexer->state = EVERMORE_LEADER_2;
else
return character_pushback(lexer, GROUND_STATE);
break;
case EVERMORE_LEADER_2:
lexer->length = (size_t) c;
if (c == DLE)
lexer->state = EVERMORE_PAYLOAD_DLE;
else
lexer->state = EVERMORE_PAYLOAD;
break;
case EVERMORE_PAYLOAD:
if (c == DLE)
lexer->state = EVERMORE_PAYLOAD_DLE;
else if (--lexer->length == 0)
return character_pushback(lexer, GROUND_STATE);
break;
case EVERMORE_PAYLOAD_DLE:
switch (c) {
case DLE:
lexer->state = EVERMORE_PAYLOAD;
break;
case ETX:
lexer->state = EVERMORE_RECOGNIZED;
break;
default:
lexer->state = GROUND_STATE;
}
break;
case EVERMORE_RECOGNIZED:
if (c == DLE)
lexer->state = EVERMORE_LEADER_1;
else
return character_pushback(lexer, GROUND_STATE);
break;
#endif /* EVERMORE_ENABLE */
#ifdef ITRAX_ENABLE
case ITALK_LEADER_1:
if (c == '!')
lexer->state = ITALK_LEADER_2;
else
return character_pushback(lexer, GROUND_STATE);
break;
case ITALK_LEADER_2:
lexer->length = (size_t) (lexer->inbuffer[6] & 0xff);
lexer->state = ITALK_LENGTH;
break;
case ITALK_LENGTH:
lexer->length += 1; /* fix number of words in payload */
lexer->length *= 2; /* convert to number of bytes */
lexer->length += 3; /* add trailer length */
lexer->state = ITALK_PAYLOAD;
break;
case ITALK_PAYLOAD:
/* lookahead for "<!" because sometimes packets are short but valid */
if ((c == '>') && (lexer->inbufptr[0] == '<') &&
(lexer->inbufptr[1] == '!')) {
lexer->state = ITALK_RECOGNIZED;
gpsd_log(&lexer->errout, LOG_IO,
"ITALK: trying to process runt packet\n");
break;
} else if (--lexer->length == 0)
lexer->state = ITALK_DELIVERED;
break;
case ITALK_DELIVERED:
if (c == '>')
lexer->state = ITALK_RECOGNIZED;
else
return character_pushback(lexer, GROUND_STATE);
break;
case ITALK_RECOGNIZED:
if (c == '<')
lexer->state = ITALK_LEADER_1;
else
return character_pushback(lexer, GROUND_STATE);
break;
#endif /* ITRAX_ENABLE */
#ifdef GEOSTAR_ENABLE
case GEOSTAR_LEADER_1:
if (c == 'S')
lexer->state = GEOSTAR_LEADER_2;
else
return character_pushback(lexer, GROUND_STATE);
break;
case GEOSTAR_LEADER_2:
if (c == 'G')
lexer->state = GEOSTAR_LEADER_3;
else
return character_pushback(lexer, GROUND_STATE);
break;
case GEOSTAR_LEADER_3:
if (c == 'G')
lexer->state = GEOSTAR_LEADER_4;
else
return character_pushback(lexer, GROUND_STATE);
break;
case GEOSTAR_LEADER_4:
lexer->state = GEOSTAR_MESSAGE_ID_1;
break;
case GEOSTAR_MESSAGE_ID_1:
lexer->state = GEOSTAR_MESSAGE_ID_2;
break;
case GEOSTAR_MESSAGE_ID_2:
lexer->length = (size_t)(c * 4);
lexer->state = GEOSTAR_LENGTH_1;
break;
case GEOSTAR_LENGTH_1:
lexer->length += (c << 8) * 4;
if (lexer->length <= MAX_PACKET_LENGTH)
lexer->state = GEOSTAR_LENGTH_2;
else
return character_pushback(lexer, GROUND_STATE);
break;
case GEOSTAR_LENGTH_2:
lexer->state = GEOSTAR_PAYLOAD;
break;
case GEOSTAR_PAYLOAD:
if (--lexer->length == 0)
lexer->state = GEOSTAR_CHECKSUM_A;
/* else stay in payload state */
break;
case GEOSTAR_CHECKSUM_A:
lexer->state = GEOSTAR_CHECKSUM_B;
break;
case GEOSTAR_CHECKSUM_B:
lexer->state = GEOSTAR_CHECKSUM_C;
break;
case GEOSTAR_CHECKSUM_C:
lexer->state = GEOSTAR_RECOGNIZED;
break;
case GEOSTAR_RECOGNIZED:
if (c == 'P')
lexer->state = GEOSTAR_LEADER_1;
else
return character_pushback(lexer, GROUND_STATE);
break;
#endif /* GEOSTAR_ENABLE */
#ifdef TSIP_ENABLE
case TSIP_LEADER:
/* unused case */
if (c >= 0x13)
lexer->state = TSIP_PAYLOAD;
else
return character_pushback(lexer, GROUND_STATE);
break;
case TSIP_PAYLOAD:
if (c == DLE)
lexer->state = TSIP_DLE;
break;
case TSIP_DLE:
switch (c) {
case ETX:
lexer->state = TSIP_RECOGNIZED;
break;
case DLE:
lexer->state = TSIP_PAYLOAD;
break;
default:
lexer->state = GROUND_STATE;
break;
}
break;
case TSIP_RECOGNIZED:
if (c == DLE)
/*
* Don't go to TSIP_LEADER state -- TSIP packets aren't
* checksummed, so false positives are easy. We might be
* looking at another DLE-stuffed protocol like EverMore
* or Garmin streaming binary.
*/
lexer->state = DLE_LEADER;
else
return character_pushback(lexer, GROUND_STATE);
break;
#endif /* TSIP_ENABLE */
#ifdef RTCM104V2_ENABLE
case RTCM2_SYNC_STATE:
case RTCM2_SKIP_STATE:
if ((isgpsstat = rtcm2_decode(lexer, c)) == ISGPS_MESSAGE) {
lexer->state = RTCM2_RECOGNIZED;
break;
} else if (isgpsstat == ISGPS_NO_SYNC)
lexer->state = GROUND_STATE;
break;
case RTCM2_RECOGNIZED:
if (c == '#')
/*
* There's a remote possibility this could fire when # =
* 0x23 is legitimate in-stream RTCM2 data. No help for
* it, the test framework needs this case so it can inject
* # EOF and we'll miss a packet.
*/
return character_pushback(lexer, GROUND_STATE);
else if (rtcm2_decode(lexer, c) == ISGPS_SYNC) {
lexer->state = RTCM2_SYNC_STATE;
break;
} else
lexer->state = GROUND_STATE;
break;
#endif /* RTCM104V2_ENABLE */
#ifdef PASSTHROUGH_ENABLE
case JSON_LEADER:
if (c == '{' || c == '[') {
lexer->json_depth++;
} else if (c == '}' || c == ']') {
if (--lexer->json_depth == 0)
lexer->state = JSON_RECOGNIZED;
} else if (isspace(c) || c == ',')
break;
else if (c == '"') {
lexer->state = JSON_STRINGLITERAL;
lexer->json_after = JSON_END_ATTRIBUTE;
} else {
gpsd_log(&lexer->errout, LOG_RAW + 2,
"%08ld: missing attribute start after header\n",
lexer->char_counter);
lexer->state = GROUND_STATE;
}
break;
case JSON_STRINGLITERAL:
if (c == '\\')
lexer->state = JSON_STRING_SOLIDUS;
else if (c == '"')
lexer->state = lexer->json_after;
break;
case JSON_STRING_SOLIDUS:
lexer->state = JSON_STRINGLITERAL;
break;
case JSON_END_ATTRIBUTE:
if (isspace(c))
break;
else if (c == ':')
lexer->state = JSON_EXPECT_VALUE;
else
/* saw something other than value start after colon */
return character_pushback(lexer, GROUND_STATE);
break;
case JSON_EXPECT_VALUE:
if (isspace(c))
break;
else if (c == '"') {
lexer->state = JSON_STRINGLITERAL;
lexer->json_after = JSON_END_VALUE;
} else if (c == '{' || c == '[') {
return character_pushback(lexer, JSON_LEADER);
} else if (strchr("-0123456789", c) != NULL) {
lexer->state = JSON_NUMBER;
} else if (c == 't' || c == 'f' || c == 'n')
/*
* This is a bit more permissive than strictly necessary, as
* GPSD JSON does not include the null token. Still, it's
* futureproofing.
*/
lexer->state = JSON_SPECIAL;
else
/* couldn't recognize start of value literal */
return character_pushback(lexer, GROUND_STATE);
break;
case JSON_NUMBER:
/*
* Will recognize some ill-formed numeric literals.
* Should be OK as we're already three stages deep inside
* JSON recognition; odds that we'll actually see an
* ill-formed literal are quite low. and the worst
* possible result if it happens is our JSON parser will
* quietly chuck out the object.
*/
if (strchr("1234567890.eE+-", c) == NULL) {
return character_pushback(lexer, JSON_END_VALUE);
}
break;
case JSON_SPECIAL:
if (strchr("truefalsnil", c) == NULL)
return character_pushback(lexer, JSON_END_VALUE);
break;
case JSON_END_VALUE:
if (isspace(c))
break;
else if (c == ',')
lexer->state = JSON_LEADER;
else if (c == '}' || c == ']')
return character_pushback(lexer, JSON_LEADER);
else
/* trailing garbage after JSON value */
return character_pushback(lexer, GROUND_STATE);
break;
#endif /* PASSTHROUGH_ENABLE */
#ifdef STASH_ENABLE
case STASH_RECOGNIZED:
if (c == '$')
lexer->state = NMEA_DOLLAR;
else
return character_pushback(lexer, GROUND_STATE);
break;
#endif /* STASH_ENABLE */
}
return true; /* no pushback */
}
static void packet_accept(struct gps_lexer_t *lexer, int packet_type)
/* packet grab succeeded, move to output buffer */
{
size_t packetlen = lexer->inbufptr - lexer->inbuffer;
if (packetlen < sizeof(lexer->outbuffer)) {
memcpy(lexer->outbuffer, lexer->inbuffer, packetlen);
lexer->outbuflen = packetlen;
lexer->outbuffer[packetlen] = '\0';
lexer->type = packet_type;
if (lexer->errout.debug >= LOG_RAW+1) {
char scratchbuf[MAX_PACKET_LENGTH*2+1];
gpsd_log(&lexer->errout, LOG_RAW+1,
"Packet type %d accepted %zu = %s\n",
packet_type, packetlen,
gpsd_packetdump(scratchbuf, sizeof(scratchbuf),
(char *)lexer->outbuffer,
lexer->outbuflen));
}
} else {
gpsd_log(&lexer->errout, LOG_ERROR,
"Rejected too long packet type %d len %zu\n",
packet_type, packetlen);
}
}
static void packet_discard(struct gps_lexer_t *lexer)
/* shift the input buffer to discard all data up to current input pointer */
{
size_t discard = lexer->inbufptr - lexer->inbuffer;
size_t remaining = lexer->inbuflen - discard;
lexer->inbufptr = memmove(lexer->inbuffer, lexer->inbufptr, remaining);
lexer->inbuflen = remaining;
if (lexer->errout.debug >= LOG_RAW+1) {
char scratchbuf[MAX_PACKET_LENGTH*2+1];
gpsd_log(&lexer->errout, LOG_RAW + 1,
"Packet discard of %zu, chars remaining is %zu = %s\n",
discard, remaining,
gpsd_packetdump(scratchbuf, sizeof(scratchbuf),
(char *)lexer->inbuffer, lexer->inbuflen));
}
}
#ifdef STASH_ENABLE
static void packet_stash(struct gps_lexer_t *lexer)
/* stash the input buffer up to current input pointer */
{
size_t stashlen = lexer->inbufptr - lexer->inbuffer;
memcpy(lexer->stashbuffer, lexer->inbuffer, stashlen);
lexer->stashbuflen = stashlen;
if (lexer->errout.debug >= LOG_RAW+1) {
char scratchbuf[MAX_PACKET_LENGTH*2+1];
gpsd_log(&lexer->errout, LOG_RAW+1,
"Packet stash of %zu = %s\n",
stashlen,
gpsd_packetdump(scratchbuf, sizeof(scratchbuf),
(char *)lexer->stashbuffer,
lexer->stashbuflen));
}
}
static void packet_unstash(struct gps_lexer_t *lexer)
/* return stash to start of input buffer */
{
size_t available = sizeof(lexer->inbuffer) - lexer->inbuflen;
size_t stashlen = lexer->stashbuflen;
if (stashlen <= available) {
memmove(lexer->inbuffer + stashlen, lexer->inbuffer, lexer->inbuflen);
memcpy(lexer->inbuffer, lexer->stashbuffer, stashlen);
lexer->inbuflen += stashlen;
lexer->stashbuflen = 0;
if (lexer->errout.debug >= LOG_RAW+1) {
char scratchbuf[MAX_PACKET_LENGTH*2+1];
gpsd_log(&lexer->errout, LOG_RAW+1,
"Packet unstash of %zu, reconstructed is %zu = %s\n",
stashlen, lexer->inbuflen,
gpsd_packetdump(scratchbuf, sizeof(scratchbuf),
(char *)lexer->inbuffer, lexer->inbuflen));
}
} else {
gpsd_log(&lexer->errout, LOG_ERROR,
"Rejected too long unstash of %zu\n", stashlen);
lexer->stashbuflen = 0;
}
}
#endif /* STASH_ENABLE */
static void character_discard(struct gps_lexer_t *lexer)
/* shift the input buffer to discard one character and reread data */
{
memmove(lexer->inbuffer, lexer->inbuffer + 1, (size_t)-- lexer->inbuflen);
lexer->inbufptr = lexer->inbuffer;
if (lexer->errout.debug >= LOG_RAW+1) {
char scratchbuf[MAX_PACKET_LENGTH*2+1];
gpsd_log(&lexer->errout, LOG_RAW + 1,
"Character discarded, buffer %zu chars = %s\n",
lexer->inbuflen,
gpsd_packetdump(scratchbuf, sizeof(scratchbuf),
(char *)lexer->inbuffer, lexer->inbuflen));
}
}
/* get 0-origin big-endian words relative to start of packet buffer */
#define getword(i) (short)(lexer->inbuffer[2*(i)] | (lexer->inbuffer[2*(i)+1] << 8))
/* entry points begin here */
void lexer_init(struct gps_lexer_t *lexer)
{
lexer->char_counter = 0;
lexer->retry_counter = 0;
#ifdef PASSTHROUGH_ENABLE
lexer->json_depth = 0;
#endif /* PASSTHROUGH_ENABLE */
#ifdef TIMING_ENABLE
lexer->start_time = 0.0;
#endif /* TIMING_ENABLE */
packet_reset(lexer);
errout_reset(&lexer->errout);
}
void packet_parse(struct gps_lexer_t *lexer)
/* grab a packet from the input buffer */
{
lexer->outbuflen = 0;
while (packet_buffered_input(lexer) > 0) {
unsigned char c = *lexer->inbufptr++;
unsigned int oldstate = lexer->state;
if (!nextstate(lexer, c))
continue;
gpsd_log(&lexer->errout, LOG_RAW + 2,
"%08ld: character '%c' [%02x], %s -> %s\n",
lexer->char_counter, (isprint(c) ? c : '.'), c,
state_table[oldstate], state_table[lexer->state]);
lexer->char_counter++;
if (lexer->state == GROUND_STATE) {
character_discard(lexer);
} else if (lexer->state == COMMENT_RECOGNIZED) {
packet_accept(lexer, COMMENT_PACKET);
packet_discard(lexer);
lexer->state = GROUND_STATE;
break;
}
#ifdef NMEA0183_ENABLE
else if (lexer->state == NMEA_RECOGNIZED) {
/*
* $PASHR packets have no checksum. Avoid the possibility
* that random garbage might make it look like they do.
*/
if (!str_starts_with((const char *)lexer->inbuffer, "$PASHR,"))
{
bool checksum_ok = true;
char csum[3] = { '0', '0', '0' };
char *end;
/*
* Back up past any whitespace. Need to do this because
* at least one GPS (the Firefly 1a) emits \r\r\n
*/
for (end = (char *)lexer->inbufptr - 1; isspace((unsigned char) *end); end--)
continue;
while (strchr("0123456789ABCDEF", *end))
--end;
if (*end == '*') {
unsigned int n, crc = 0;
for (n = 1; (char *)lexer->inbuffer + n < end; n++)
crc ^= lexer->inbuffer[n];
(void)snprintf(csum, sizeof(csum), "%02X", crc);
checksum_ok = (csum[0] == toupper((unsigned char) end[1])
&& csum[1] == toupper((unsigned char) end[2]));
}
if (!checksum_ok) {
gpsd_log(&lexer->errout, LOG_WARN,
"bad checksum in NMEA packet; expected %s.\n",
csum);
packet_accept(lexer, BAD_PACKET);
lexer->state = GROUND_STATE;
packet_discard(lexer);
break; /* exit case */
}
}
/* checksum passed or not present */
#ifdef AIVDM_ENABLE
if (str_starts_with((char *)lexer->inbuffer, "!AIVDM"))
packet_accept(lexer, AIVDM_PACKET);
else if (str_starts_with((char *)lexer->inbuffer, "!AIVDO"))
packet_accept(lexer, AIVDM_PACKET);
else if (str_starts_with((char *)lexer->inbuffer, "!BSVDM"))
packet_accept(lexer, AIVDM_PACKET);
else if (str_starts_with((char *)lexer->inbuffer, "!BSVDO"))
packet_accept(lexer, AIVDM_PACKET);
else if (str_starts_with((char *)lexer->inbuffer, "!ABVDM"))
packet_accept(lexer, AIVDM_PACKET);
else if (str_starts_with((char *)lexer->inbuffer, "!ABVDO"))
packet_accept(lexer, AIVDM_PACKET);
else if (str_starts_with((char *)lexer->inbuffer, "!ANVDM"))
packet_accept(lexer, AIVDM_PACKET);
else if (str_starts_with((char *)lexer->inbuffer, "!ANVDO"))
packet_accept(lexer, AIVDM_PACKET);
else if (str_starts_with((char *)lexer->inbuffer, "!SAVDM"))
packet_accept(lexer, AIVDM_PACKET);
else if (str_starts_with((char *)lexer->inbuffer, "!SAVDO"))
packet_accept(lexer, AIVDM_PACKET);
else
#endif /* AIVDM_ENABLE */
packet_accept(lexer, NMEA_PACKET);
packet_discard(lexer);
#ifdef STASH_ENABLE
if (lexer->stashbuflen)
packet_unstash(lexer);
#endif /* STASH_ENABLE */
break;
}
#endif /* NMEA0183_ENABLE */
#ifdef SIRF_ENABLE
else if (lexer->state == SIRF_RECOGNIZED) {
unsigned char *trailer = lexer->inbufptr - 4;
unsigned int checksum =
(unsigned)((trailer[0] << 8) | trailer[1]);
unsigned int n, crc = 0;
for (n = 4; n < (unsigned)(trailer - lexer->inbuffer); n++)
crc += (int)lexer->inbuffer[n];
crc &= 0x7fff;
if (checksum == crc)
packet_accept(lexer, SIRF_PACKET);
else {
packet_accept(lexer, BAD_PACKET);
lexer->state = GROUND_STATE;
}
packet_discard(lexer);
break;
}
#endif /* SIRF_ENABLE */
#ifdef SKYTRAQ_ENABLE
else if (lexer->state == SKY_RECOGNIZED) {
packet_accept(lexer, SKY_PACKET);
packet_discard(lexer);
break;
}
#endif /* SKYTRAQ_ENABLE */
#ifdef SUPERSTAR2_ENABLE
else if (lexer->state == SUPERSTAR2_RECOGNIZED) {
unsigned a = 0, b;
size_t n;
lexer->length = 4 + (size_t) lexer->inbuffer[3] + 2;
for (n = 0; n < lexer->length - 2; n++)
a += (unsigned)lexer->inbuffer[n];
b = (unsigned)getleu16(lexer->inbuffer, lexer->length - 2);
gpsd_log(&lexer->errout, LOG_IO,
"SuperStarII pkt dump: type %u len %u\n",
lexer->inbuffer[1], (unsigned int)lexer->length);
if (a != b) {
gpsd_log(&lexer->errout, LOG_IO,
"REJECT SuperStarII packet type 0x%02x"
"%zd bad checksum 0x%04x, expecting 0x%04x\n",
lexer->inbuffer[1], lexer->length, a, b);
packet_accept(lexer, BAD_PACKET);
lexer->state = GROUND_STATE;
} else {
packet_accept(lexer, SUPERSTAR2_PACKET);
}
packet_discard(lexer);
break;
}
#endif /* SUPERSTAR2_ENABLE */
#ifdef ONCORE_ENABLE
else if (lexer->state == ONCORE_RECOGNIZED) {
char a, b;
int i, len;
len = lexer->inbufptr - lexer->inbuffer;
a = (char)(lexer->inbuffer[len - 3]);
b = '\0';
for (i = 2; i < len - 3; i++)
b ^= lexer->inbuffer[i];
if (a == b) {
gpsd_log(&lexer->errout, LOG_IO,
"Accept OnCore packet @@%c%c len %d\n",
lexer->inbuffer[2], lexer->inbuffer[3], len);
packet_accept(lexer, ONCORE_PACKET);
} else {
gpsd_log(&lexer->errout, LOG_IO,
"REJECT OnCore packet @@%c%c len %d\n",
lexer->inbuffer[2], lexer->inbuffer[3], len);
packet_accept(lexer, BAD_PACKET);
lexer->state = GROUND_STATE;
}
packet_discard(lexer);
break;
}
#endif /* ONCORE_ENABLE */
#if defined(TSIP_ENABLE) || defined(GARMIN_ENABLE)
else if (lexer->state == TSIP_RECOGNIZED) {
size_t packetlen = lexer->inbufptr - lexer->inbuffer;
#ifdef TSIP_ENABLE
unsigned int pos, dlecnt;
/* don't count stuffed DLEs in the length */
dlecnt = 0;
for (pos = 0; pos < (unsigned int)packetlen; pos++)
if (lexer->inbuffer[pos] == DLE)
dlecnt++;
if (dlecnt > 2) {
dlecnt -= 2;
dlecnt /= 2;
gpsd_log(&lexer->errout, LOG_RAW,
"Unstuffed %d DLEs\n", dlecnt);
packetlen -= dlecnt;
}
#endif /* TSIP_ENABLE */
if (packetlen < 5) {
lexer->state = GROUND_STATE;
} else {
unsigned int pkt_id;
#ifdef GARMIN_ENABLE
unsigned int len;
size_t n;
unsigned int ch, chksum;
n = 0;
#ifdef TSIP_ENABLE
/* shortcut garmin */
if (TSIP_PACKET == lexer->type)
goto not_garmin;
#endif /* TSIP_ENABLE */
if (lexer->inbuffer[n++] != DLE)
goto not_garmin;
pkt_id = lexer->inbuffer[n++]; /* packet ID */
len = lexer->inbuffer[n++];
chksum = len + pkt_id;
if (len == DLE) {
if (lexer->inbuffer[n++] != DLE)
goto not_garmin;
}
for (; len > 0; len--) {
chksum += lexer->inbuffer[n];
if (lexer->inbuffer[n++] == DLE) {
if (lexer->inbuffer[n++] != DLE)
goto not_garmin;
}
}
/* check sum byte */
ch = lexer->inbuffer[n++];
chksum += ch;
if (ch == DLE) {
if (lexer->inbuffer[n++] != DLE)
goto not_garmin;
}
if (lexer->inbuffer[n++] != DLE)
goto not_garmin;
/* we used to say n++ here, but scan-build complains */
if (lexer->inbuffer[n] != ETX)
goto not_garmin;
chksum &= 0xff;
if (chksum) {
gpsd_log(&lexer->errout, LOG_IO,
"Garmin checksum failed: %02x!=0\n", chksum);
goto not_garmin;
}
packet_accept(lexer, GARMIN_PACKET);
packet_discard(lexer);
break;
not_garmin:;
gpsd_log(&lexer->errout, LOG_RAW + 1,
"Not a Garmin packet\n");
#endif /* GARMIN_ENABLE */
#ifdef TSIP_ENABLE
/* check for some common TSIP packet types:
* 0x13, TSIP Parsing Error Notification
* 0x38, Request SV system data
* 0x1c, Hardware/Software Version Information
* 0x41, GPS time, data length 10
* 0x42, Single Precision Fix, data length 16
* 0x43, Velocity Fix, data length 20
* 0x45, Software Version Information, data length 10
* 0x46, Health of Receiver, data length 2
* 0x48, GPS System Messages, data length 22
* 0x49, Almanac Health Page, data length 32
* 0x4a, LLA Position, data length 20
* 0x4b, Machine Code Status, data length 3
* 0x4c, Operating Parameters Report, data length 17
* 0x54, One Satellite Bias, data length 4
* 0x56, Velocity Fix (ENU), data length 20
* 0x57, Last Computed Fix Report, data length 8
* 0x5a, Raw Measurements
* 0x5b, Satellite Ephemeris Status, data length 16
* 0x5c, Satellite Tracking Status, data length 24
* 0x5e, Additional Fix Status Report
* 0x6d, All-In-View Satellite Selection, data length 16+numSV
* 0x82, Differential Position Fix Mode, data length 1
* 0x83, Double Precision XYZ, data length 36
* 0x84, Double Precision LLA, data length 36
* 0xbb, GPS Navigation Configuration
* 0xbc, Receiver Port Configuration
*
* <DLE>[pkt id] [data] <DLE><ETX>
*
* The best description is in [TSIP], the Trimble Standard
* Interface Protocol manual; unless otherwise specified
* that is where these type/length notifications are from.
*
* Note that not all Trimble chips conform perfectly to this
* specification, nor does it cover every packet type we
* may see on the wire.
*/
pkt_id = lexer->inbuffer[1]; /* packet ID */
/* *INDENT-OFF* */
if (!((0x13 == pkt_id) ||
(0x1c == pkt_id) ||
(0xbb == pkt_id) ||
(0xbc == pkt_id) ||
(0x38 == pkt_id))
&& ((0x41 > pkt_id) || (0x8f < pkt_id))) {
gpsd_log(&lexer->errout, LOG_IO,
"Packet ID 0x%02x out of range for TSIP\n",
pkt_id);
goto not_tsip;
}
/* *INDENT-ON* */
#define TSIP_ID_AND_LENGTH(id, len) ((id == pkt_id) && (len == packetlen-4))
if ((0x13 == pkt_id) && (1 <= packetlen))
/* pass */ ;
/*
* Not in [TSIP], Accutime Gold only. Variable length.
*/
else if ((0x1c == pkt_id) && (11 <= packetlen))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x41, 10))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x42, 16))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x43, 20))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x45, 10))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x46, 2))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x48, 22))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x49, 32))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x4a, 20))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x4b, 3))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x4c, 17))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x54, 12))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x55, 4))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x56, 20))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x57, 8))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x5a, 25))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x5b, 16))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x5c, 24))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x5e, 2))
/* pass */ ;
/*
* Not in [TSIP]. It's unclear where this test came from or
* why it's here; the TSIP driver doesn't use type 0x5f.
*/
else if (TSIP_ID_AND_LENGTH(0x5f, 66))
/* pass */ ;
/* 0x6d is variable length depending on the sat picture */
else if ((0x6d == pkt_id)
&& ((0x14 <= packetlen) && (0x20 >= packetlen)))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x82, 1))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x83, 36))
/* pass */ ;
else if (TSIP_ID_AND_LENGTH(0x84, 36))
/* pass */ ;
/* super packets, variable length */
else if ((0x8e == pkt_id) || (0x8f == pkt_id))
/* pass */ ;
/*
* This is according to [TSIP].
*/
else if (TSIP_ID_AND_LENGTH(0xbb, 40))
/* pass */ ;
/*
* The Accutime Gold ships a version of this packet with a
* 43-byte payload. We only use the first 21 bytes, and
* parts after byte 27 are padding.
*/
else if (TSIP_ID_AND_LENGTH(0xbb, 43))
/* pass */ ;
else {
/* pass */ ;
gpsd_log(&lexer->errout, LOG_IO,
"TSIP REJECT pkt_id = %#02x, packetlen= %zu\n",
pkt_id, packetlen);
goto not_tsip;
}
#undef TSIP_ID_AND_LENGTH
/* Debug */
gpsd_log(&lexer->errout, LOG_RAW,
"TSIP pkt_id = %#02x, packetlen= %zu\n",
pkt_id, packetlen);
packet_accept(lexer, TSIP_PACKET);
packet_discard(lexer);
break;
not_tsip:
gpsd_log(&lexer->errout, LOG_RAW + 1, "Not a TSIP packet\n");
/*
* More attempts to recognize ambiguous TSIP-like
* packet types could go here.
*/
packet_accept(lexer, BAD_PACKET);
lexer->state = GROUND_STATE;
packet_discard(lexer);
break;
#endif /* TSIP_ENABLE */
}
}
#endif /* TSIP_ENABLE || GARMIN_ENABLE */
#ifdef RTCM104V3_ENABLE
else if (lexer->state == RTCM3_RECOGNIZED) {
if (crc24q_check(lexer->inbuffer,
lexer->inbufptr - lexer->inbuffer)) {
packet_accept(lexer, RTCM3_PACKET);
} else {
gpsd_log(&lexer->errout, LOG_IO,
"RTCM3 data checksum failure, "
"%0x against %02x %02x %02x\n",
crc24q_hash(lexer->inbuffer,
lexer->inbufptr - lexer->inbuffer -
3), lexer->inbufptr[-3],
lexer->inbufptr[-2], lexer->inbufptr[-1]);
packet_accept(lexer, BAD_PACKET);
}
packet_discard(lexer);
lexer->state = GROUND_STATE;
break;
}
#endif /* RTCM104V3_ENABLE */
#ifdef ZODIAC_ENABLE
else if (lexer->state == ZODIAC_RECOGNIZED) {
short len, n, sum;
len = getword(2);
for (n = sum = 0; n < len; n++)
sum += getword(5 + n);
sum *= -1;
if (len == 0 || sum == getword(5 + len)) {
packet_accept(lexer, ZODIAC_PACKET);
} else {
gpsd_log(&lexer->errout, LOG_IO,
"Zodiac data checksum 0x%hx over length %hd, expecting 0x%hx\n",
sum, len, getword(5 + len));
packet_accept(lexer, BAD_PACKET);
lexer->state = GROUND_STATE;
}
packet_discard(lexer);
break;
}
#endif /* ZODIAC_ENABLE */
#ifdef UBLOX_ENABLE
else if (lexer->state == UBX_RECOGNIZED) {
/* UBX use a TCP like checksum */
int n, len;
unsigned char ck_a = (unsigned char)0;
unsigned char ck_b = (unsigned char)0;
len = lexer->inbufptr - lexer->inbuffer;
gpsd_log(&lexer->errout, LOG_IO, "UBX: len %d\n", len);
for (n = 2; n < (len - 2); n++) {
ck_a += lexer->inbuffer[n];
ck_b += ck_a;
}
if (ck_a == lexer->inbuffer[len - 2] &&
ck_b == lexer->inbuffer[len - 1])
packet_accept(lexer, UBX_PACKET);
else {
gpsd_log(&lexer->errout, LOG_IO,
"UBX checksum 0x%02hhx%02hhx over length %d,"
" expecting 0x%02hhx%02hhx (type 0x%02hhx%02hhx)\n",
ck_a,
ck_b,
len,
lexer->inbuffer[len - 2],
lexer->inbuffer[len - 1],
lexer->inbuffer[2], lexer->inbuffer[3]);
packet_accept(lexer, BAD_PACKET);
lexer->state = GROUND_STATE;
}
packet_discard(lexer);
break;
}
#endif /* UBLOX_ENABLE */
#ifdef EVERMORE_ENABLE
else if (lexer->state == EVERMORE_RECOGNIZED) {
unsigned int n, crc, checksum, len;
n = 0;
if (lexer->inbuffer[n++] != DLE)
goto not_evermore;
if (lexer->inbuffer[n++] != STX)
goto not_evermore;
len = lexer->inbuffer[n++];
if (len == DLE) {
if (lexer->inbuffer[n++] != DLE)
goto not_evermore;
}
len -= 2;
crc = 0;
for (; len > 0; len--) {
crc += lexer->inbuffer[n];
if (lexer->inbuffer[n++] == DLE) {
if (lexer->inbuffer[n++] != DLE)
goto not_evermore;
}
}
checksum = lexer->inbuffer[n++];
if (checksum == DLE) {
if (lexer->inbuffer[n++] != DLE)
goto not_evermore;
}
if (lexer->inbuffer[n++] != DLE)
goto not_evermore;
/* we used to say n++ here, but scan-build complains */
if (lexer->inbuffer[n] != ETX)
goto not_evermore;
crc &= 0xff;
if (crc != checksum) {
gpsd_log(&lexer->errout, LOG_IO,
"EverMore checksum failed: %02x != %02x\n",
crc, checksum);
goto not_evermore;
}
packet_accept(lexer, EVERMORE_PACKET);
packet_discard(lexer);
break;
not_evermore:
packet_accept(lexer, BAD_PACKET);
lexer->state = GROUND_STATE;
packet_discard(lexer);
break;
}
#endif /* EVERMORE_ENABLE */
/* XXX CSK */
#ifdef ITRAX_ENABLE
#define getib(j) ((uint8_t)lexer->inbuffer[(j)])
#define getiw(i) ((uint16_t)(((uint16_t)getib((i)+1) << 8) | (uint16_t)getib((i))))
else if (lexer->state == ITALK_RECOGNIZED) {
volatile uint16_t len, n, csum, xsum;
/* number of words */
len = (uint16_t) (lexer->inbuffer[6] & 0xff);
/* expected checksum */
xsum = getiw(7 + 2 * len);
csum = 0;
for (n = 0; n < len; n++) {
volatile uint16_t tmpw = getiw(7 + 2 * n);
volatile uint32_t tmpdw = (csum + 1) * (tmpw + n);
csum ^= (tmpdw & 0xffff) ^ ((tmpdw >> 16) & 0xffff);
}
if (len == 0 || csum == xsum)
packet_accept(lexer, ITALK_PACKET);
else {
gpsd_log(&lexer->errout, LOG_IO,
"ITALK: checksum failed - "
"type 0x%02x expected 0x%04x got 0x%04x\n",
lexer->inbuffer[4], xsum, csum);
packet_accept(lexer, BAD_PACKET);
lexer->state = GROUND_STATE;
}
packet_discard(lexer);
break;
}
#undef getiw
#undef getib
#endif /* ITRAX_ENABLE */
#ifdef NAVCOM_ENABLE
else if (lexer->state == NAVCOM_RECOGNIZED) {
/* By the time we got here we know checksum is OK */
packet_accept(lexer, NAVCOM_PACKET);
packet_discard(lexer);
break;
}
#endif /* NAVCOM_ENABLE */
#ifdef GEOSTAR_ENABLE
else if (lexer->state == GEOSTAR_RECOGNIZED) {
/* GeoStar uses a XOR 32bit checksum */
int n, len;
unsigned int cs = 0L;
len = lexer->inbufptr - lexer->inbuffer;
/* Calculate checksum */
for (n = 0; n < len; n += 4) {
cs ^= getleu32(lexer->inbuffer, n);
}
if (cs == 0)
packet_accept(lexer, GEOSTAR_PACKET);
else {
gpsd_log(&lexer->errout, LOG_IO,
"GeoStar checksum failed 0x%x over length %d\n",
cs, len);
packet_accept(lexer, BAD_PACKET);
lexer->state = GROUND_STATE;
}
packet_discard(lexer);
break;
}
#endif /* GEOSTAR_ENABLE */
#ifdef RTCM104V2_ENABLE
else if (lexer->state == RTCM2_RECOGNIZED) {
/*
* RTCM packets don't have checksums. The six bits of parity
* per word and the preamble better be good enough.
*/
packet_accept(lexer, RTCM2_PACKET);
packet_discard(lexer);
break;
}
#endif /* RTCM104V2_ENABLE */
#ifdef GARMINTXT_ENABLE
else if (lexer->state == GTXT_RECOGNIZED) {
size_t packetlen = lexer->inbufptr - lexer->inbuffer;
if (57 <= packetlen) {
packet_accept(lexer, GARMINTXT_PACKET);
packet_discard(lexer);
lexer->state = GROUND_STATE;
break;
} else {
packet_accept(lexer, BAD_PACKET);
lexer->state = GROUND_STATE;
}
}
#endif
#ifdef PASSTHROUGH_ENABLE
else if (lexer->state == JSON_RECOGNIZED) {
size_t packetlen = lexer->inbufptr - lexer->inbuffer;
if (packetlen >= 11)
/* {"class": } */
packet_accept(lexer, JSON_PACKET);
else
packet_accept(lexer, BAD_PACKET);
packet_discard(lexer);
lexer->state = GROUND_STATE;
break;
}
#endif /* PASSTHROUGH_ENABLE */
#ifdef STASH_ENABLE
else if (lexer->state == STASH_RECOGNIZED) {
packet_stash(lexer);
packet_discard(lexer);
}
#endif /* STASH_ENABLE */
} /* while */
}
#undef getword
ssize_t packet_get(int fd, struct gps_lexer_t *lexer)
/* grab a packet; return -1=>I/O error, 0=>EOF, or a length */
{
ssize_t recvd;
errno = 0;
recvd = read(fd, lexer->inbuffer + lexer->inbuflen,
sizeof(lexer->inbuffer) - (lexer->inbuflen));
if (recvd == -1) {
if ((errno == EAGAIN) || (errno == EINTR)) {
gpsd_log(&lexer->errout, LOG_RAW + 2, "no bytes ready\n");
recvd = 0;
/* fall through, input buffer may be nonempty */
} else {
gpsd_log(&lexer->errout, LOG_RAW + 2,
"errno: %s\n", strerror(errno));
return -1;
}
} else {
if (lexer->errout.debug >= LOG_RAW+1) {
char scratchbuf[MAX_PACKET_LENGTH*2+1];
gpsd_log(&lexer->errout, LOG_RAW + 1,
"Read %zd chars to buffer offset %zd (total %zd): %s\n",
recvd, lexer->inbuflen, lexer->inbuflen + recvd,
gpsd_packetdump(scratchbuf, sizeof(scratchbuf),
(char *)lexer->inbufptr, (size_t) recvd));
}
lexer->inbuflen += recvd;
}
gpsd_log(&lexer->errout, LOG_SPIN,
"packet_get() fd %d -> %zd (%d)\n",
fd, recvd, errno);
/*
* Bail out, indicating no more input, only if we just received
* nothing from the device and there is nothing waiting in the
* packet input buffer.
*/
if (recvd <= 0 && packet_buffered_input(lexer) <= 0)
return recvd;
/* Otherwise, consume from the packet input buffer */
/* coverity[tainted_data] */
packet_parse(lexer);
/* if input buffer is full, discard */
if (sizeof(lexer->inbuffer) == (lexer->inbuflen)) {
/* coverity[tainted_data] */
packet_discard(lexer);
lexer->state = GROUND_STATE;
}
/*
* If we gathered a packet, return its length; it will have been
* consumed out of the input buffer and moved to the output
* buffer. We don't care whether the read() returned 0 or -1 and
* gathered packet data was all buffered or whether it was partly
* just physically read.
*
* Note: this choice greatly simplifies life for callers of
* packet_get(), but means that they cannot tell when a nonzero
* return means there was a successful physical read. They will
* thus credit a data source that drops out with being alive
* slightly longer than it actually was. This is unlikely to
* matter as long as any policy timeouts are large compared to
* the time required to consume the greatest possible amount
* of buffered input, but if you hack this code you need to
* be aware of the issue. It might also slightly affect
* performance profiling.
*/
if (lexer->outbuflen > 0)
return (ssize_t) lexer->outbuflen;
else
/*
* Otherwise recvd is the size of whatever packet fragment we got.
* It can still be 0 or -1 at this point even if buffer data
* was consumed.
*/
return recvd;
}
void packet_reset(struct gps_lexer_t *lexer)
/* return the packet machine to the ground state */
{
lexer->type = BAD_PACKET;
lexer->state = GROUND_STATE;
lexer->inbuflen = 0;
lexer->inbufptr = lexer->inbuffer;
#ifdef BINARY_ENABLE
isgps_init(lexer);
#endif /* BINARY_ENABLE */
#ifdef STASH_ENABLE
lexer->stashbuflen = 0;
#endif /* STASH_ENABLE */
}
#ifdef __UNUSED__
void packet_pushback(struct gps_lexer_t *lexer)
/* push back the last packet grabbed */
{
if (lexer->outbuflen + lexer->inbuflen < MAX_PACKET_LENGTH) {
memmove(lexer->inbuffer + lexer->outbuflen,
lexer->inbuffer, lexer->inbuflen);
memmove(lexer->inbuffer, lexer->outbuffer, lexer->outbuflen);
lexer->inbuflen += lexer->outbuflen;
lexer->inbufptr += lexer->outbuflen;
lexer->outbuflen = 0;
}
}
#endif /* __UNUSED */
|