First step towards RTCM2 JSON parsing.

Handles message types 3, 4, 6, and 16 (the easy ones). No unit test
yet. Not ready for production.

1 files changed, 133 insertions, 0 deletions

diff --git a/rtcm2_json.c b/rtcm2_json.c
new file mode 100644
index 00000000..35f37360
--- /dev/null
+++ b/rtcm2_json.c
@@ -0,0 +1,133 @@
+/****************************************************************************
+
+NAME
+   rtcm2_json.c - deserialize RTCM2 JSON
+
+DESCRIPTION
+   This module uses the generic JSON parser to get data from RTCM2
+representations to libgps structures.
+
+***************************************************************************/
+
+#include <math.h>
+#include <assert.h>
+#include <string.h>
+#include <stddef.h>
+#include <stdio.h>
+
+#include "gpsd_config.h"
+#include "gpsd.h"
+#include "gps_json.h"
+
+/* common fields in every RTCM2 message */
+
+int json_rtcm2_read(const char *buf, 
+		    char *path, size_t pathlen,
+		    struct rtcm2_t *rtcm2, 
+		    const char **endptr)
+{
+
+#define RTCM2_HEADER \
+	{"class",          check,    .dflt.check = "RTCM2"}, \
+	{"type",           uinteger, .addr.uinteger = &rtcm2->type}, \
+	{"device",         string,   .addr.string = path, \
+	                             .len = pathlen}, \
+	{"station_id",     uinteger, .addr.uinteger = &rtcm2->refstaid}, \
+	{"zcount",         real,     .addr.real = &rtcm2->zcount, \
+			             .dflt.real = NAN}, \
+	{"seqnum",         uinteger, .addr.uinteger = &rtcm2->seqnum}, \
+	{"length",         uinteger, .addr.uinteger = &rtcm2->length}, \
+	{"station_health", uinteger, .addr.uinteger = &rtcm2->stathlth},
+
+    int status;
+    const struct json_attr_t json_rtcm1[] = {
+	// FIXME
+	RTCM2_HEADER
+	{NULL},
+    };
+
+    const struct json_attr_t json_rtcm3[] = {
+	RTCM2_HEADER
+        {"valid",          boolean, .addr.boolean = &rtcm2->reference.valid},
+	{"x",              real,    .addr.real = &rtcm2->ecef.x,
+			            .dflt.real = NAN},
+	{"y",              real,    .addr.real = &rtcm2->ecef.y,
+			            .dflt.real = NAN},
+	{"z",              real,    .addr.real = &rtcm2->ecef.z,
+			            .dflt.real = NAN},
+	{NULL},
+    };
+
+    const struct json_attr_t json_rtcm4[] = {
+	RTCM2_HEADER
+        {"valid",          boolean, .addr.boolean = &rtcm2->reference.valid},
+	{"system",         integer, .addr.integer = &rtcm2->reference.system},
+	{"sense",          integer, .addr.integer = &rtcm2->reference.sense},
+	{"datum",          string,  .addr.string = rtcm2->reference.datum,
+	                            .len = sizeof(rtcm2->reference.datum)},
+	{"dx",             real,    .addr.real = &rtcm2->reference.dx,
+			            .dflt.real = NAN},
+	{"dy",             real,    .addr.real = &rtcm2->reference.dy,
+			            .dflt.real = NAN},
+	{"dz",             real,    .addr.real = &rtcm2->reference.dz,
+			            .dflt.real = NAN},
+	{NULL},
+    };
+
+    const struct json_attr_t json_rtcm5[] = {
+	// FIXME
+	RTCM2_HEADER
+	{NULL},
+    };
+
+    const struct json_attr_t json_rtcm6[] = {
+	RTCM2_HEADER
+	// No-op or keepalive message
+	{NULL},
+    };
+
+    const struct json_attr_t json_rtcm7[] = {
+	// FIXME
+	RTCM2_HEADER
+	{NULL},
+    };
+
+    const struct json_attr_t json_rtcm16[] = {
+	RTCM2_HEADER
+	{"message",        string,  .addr.string = rtcm2->message,
+	                            .len = sizeof(rtcm2->message)},
+	{NULL},
+    };
+
+    const struct json_attr_t json_rtcm_fallback[] = {
+	// FIXME
+	RTCM2_HEADER
+	{NULL},
+    };
+
+#undef RTCM2_HEADER
+
+    memset(rtcm2, '\0', sizeof(struct rtcm2_t));
+
+    if (strstr(buf, "\"type\":1") != NULL || strstr(buf, "\"type\":9") != NULL)
+	status = json_read_object(buf, json_rtcm1, endptr);
+    else if (strstr(buf, "\"type\":3") != NULL)
+	status = json_read_object(buf, json_rtcm3, endptr);
+    else if (strstr(buf, "\"type\":4") != NULL) {
+	status = json_read_object(buf, json_rtcm4, endptr);
+    } else if (strstr(buf, "\"type\":5") != NULL)
+	status = json_read_object(buf, json_rtcm5, endptr);
+    else if (strstr(buf, "\"type\":6") != NULL)
+	status = json_read_object(buf, json_rtcm6, endptr);
+    else if (strstr(buf, "\"type\":7") != NULL)
+	status = json_read_object(buf, json_rtcm7, endptr);
+    else if (strstr(buf, "\"type\":16") != NULL)
+	status = json_read_object(buf, json_rtcm16, endptr);
+    else
+	status = json_read_object(buf, json_rtcm_fallback, endptr);
+    if (status != 0)
+	return status;
+    return 0;
+}
+
+/* rtcm2_json.c ends here */