Start on support for unpacking RTCM3 JSON.

Only the 1001 sentence so far, with two fields missing. Not usable
for production yet, but gets infrastructure in place.

1 files changed, 114 insertions, 0 deletions

diff --git a/rtcm3_json.c b/rtcm3_json.c
new file mode 100644
index 00000000..70cd3279
--- /dev/null
+++ b/rtcm3_json.c
@@ -0,0 +1,114 @@
+/****************************************************************************
+
+NAME
+   rtcm3_json.c - deserialize RTCM3 JSON
+
+DESCRIPTION
+   This module uses the generic JSON parser to get data from RTCM3
+representations to libgps structures.
+
+PERMISSIONS
+   This file is Copyright (c) 2013 by the GPSD project
+   BSD terms apply: see the file COPYING in the distribution root for details.
+
+***************************************************************************/
+
+#include <stdio.h>
+#include <math.h>
+#include <string.h>
+#include <stddef.h>
+
+#include "gpsd.h"
+
+#ifdef SOCKET_EXPORT_ENABLE
+#include "gps_json.h"
+
+int json_rtcm3_read(const char *buf,
+		    char *path, size_t pathlen, struct rtcm3_t *rtcm3,
+		    /*@null@*/ const char **endptr)
+{
+
+    static char *stringptrs[NITEMS(rtcm3->rtcmtypes.data)];
+    static char stringstore[sizeof(rtcm3->rtcmtypes.data) * 2];
+    static int stringcount;
+
+/* *INDENT-OFF* */
+#define RTCM3_HEADER \
+	{"class",          t_check,    .dflt.check = "RTCM3"}, \
+	{"type",           t_uinteger, .addr.uinteger = &rtcm3->type}, \
+	{"device",         t_string,   .addr.string = path, \
+	                                  .len = pathlen}, \
+	{"length",         t_uinteger, .addr.uinteger = &rtcm3->length},
+
+    int status = 0, satcount = 0;
+
+    /*@ -fullinitblock @*/
+    const struct json_attr_t rtcm1001_satellite[] = {
+	{"ident",     t_uinteger, STRUCTOBJECT(struct rtcm3_1001_t, ident)},
+	{"ind",       t_uinteger, STRUCTOBJECT(struct rtcm3_1001_t, L1.indicator)},
+	{"prange",    t_real,     STRUCTOBJECT(struct rtcm3_1001_t, L1.pseudorange)},
+	{"delta",     t_real,     STRUCTOBJECT(struct rtcm3_1001_t, L1.rangediff)},
+
+	{"lockt",     t_uinteger, STRUCTOBJECT(struct rtcm3_1001_t, L1.locktime)},
+	{NULL},
+    };
+    /*@-type@*//* STRUCTARRAY confuses splint */
+#define R1001	&rtcm3->rtcmtypes.rtcm3_1001.header
+    const struct json_attr_t json_rtcm1001[] = {
+	RTCM3_HEADER
+	//{"station_id",     t_uinteger, .addr.uinteger = R1001.station_id}, \
+	{"tow",            t_uinteger, .addr.uinteger = R1001.tow}, \
+        {"sync",           t_boolean,  .addr.boolean = R1001.sync},
+        {"smoothing",      t_boolean,  .addr.boolean = R1001.smoothing},
+	//{"interval",       t_uinteger, .addr.uinteger = R1001.interval},
+        {"satellites",     t_array,	STRUCTARRAY(rtcm3->rtcmtypes.rtcm3_1001.rtk_data,
+					    rtcm1001_satellite, &satcount)},
+	{NULL},
+    };
+#undef R1001
+    /*@+type@*/
+
+    /*@-type@*//* complex union array initislizations confuses splint */
+    const struct json_attr_t json_rtcm3_fallback[] = {
+	RTCM3_HEADER
+	{"data",         t_array, .addr.array.element_type = t_string,
+	                             .addr.array.arr.strings.ptrs = stringptrs,
+	                             .addr.array.arr.strings.store = stringstore,
+	                             .addr.array.arr.strings.storelen = sizeof(stringstore),
+	                             .addr.array.count = &stringcount,
+	                             .addr.array.maxlen = NITEMS(stringptrs)},
+	{NULL},
+    };
+    /*@+type@*/
+    /*@ +fullinitblock @*/
+
+#undef RTCM3_HEADER
+/* *INDENT-ON* */
+
+    memset(rtcm3, '\0', sizeof(struct rtcm3_t));
+
+    if (strstr(buf, "\"type\":1001,") != NULL) {
+	status = json_read_object(buf, json_rtcm1001, endptr);
+	if (status == 0)
+	    rtcm3->rtcmtypes.rtcm3_1003.header.satcount = (unsigned)satcount;
+    } else {
+	int n;
+	status = json_read_object(buf, json_rtcm3_fallback, endptr);
+	for (n = 0; n < NITEMS(rtcm3->rtcmtypes.data); n++) {
+	    if (n >= stringcount) {
+		rtcm3->rtcmtypes.data[n] = 0;
+	    } else {
+		unsigned int u;
+		int fldcount = sscanf(stringptrs[n], "0x%02x\n", &u);
+		if (fldcount != 1)
+		    return JSON_ERR_MISC;
+		else
+		    rtcm3->rtcmtypes.data[n] = (unsigned char)u;
+	    }
+	}
+    }
+    return status;
+}
+#endif /* SOCKET_EXPORT_ENABLE */
+
+/* rtcm3_json.c ends here */