From: Thomas Hooge <thomas@hoogi.de>
Date: Tue, 18 Oct 2016 07:06:38 +0000 (+0200)
Subject: Switched from strptime to sscanf, added command line switch to set system clock and... 
X-Git-Url: http://git.openwrt.org//?p=project%2Fugps.git;a=commitdiff_plain;h=32a6b2b702c3b9f8c425f3d9dc9f4273e276029c

Switched from strptime to sscanf, added command line switch to set system clock and fixed typo

Signed-off-by: Thomas Hogge <thomas@hoogi.de>
---

diff --git a/main.c b/main.c
index 6ff4c17..7696cbc 100644
--- a/main.c
+++ b/main.c
@@ -33,6 +33,7 @@ static struct ubus_auto_conn conn;
 static struct blob_buf b;
 static char *ubus_socket;
 struct timespec stamp = { 0 };
+unsigned int adjust_clock = 0;
 
 void
 gps_timestamp(void)
@@ -57,7 +58,7 @@ gps_info(struct ubus_context *ctx, struct ubus_object *obj,
 		blobmsg_add_u32(&b, "age", now.tv_sec - stamp.tv_sec);
 		blobmsg_add_string(&b, "latitude", latitude);
 		blobmsg_add_string(&b, "longitude", longitude);
-		blobmsg_add_string(&b, "elivation", elivation);
+		blobmsg_add_string(&b, "elevation", elevation);
 		blobmsg_add_string(&b, "course", course);
 		blobmsg_add_string(&b, "speed", speed);
 	}
@@ -95,6 +96,7 @@ usage(const char *prog)
 {
 	fprintf(stderr, "Usage: %s [options] <device>\n"
 		"Options:\n"
+		"	-a		Adjust system clock from gps\n"
 		"	-s <path>	Path to ubus socket\n"
 		"	-d <level>	Enable debug messages\n"
 		"	-S		Print messages to stdout\n"
@@ -117,8 +119,11 @@ main(int argc, char ** argv)
 		unsetenv("DBGLVL");
 	}
 
-	while ((ch = getopt(argc, argv, "d:D:s:S")) != -1) {
+	while ((ch = getopt(argc, argv, "ad:s:S")) != -1) {
 		switch (ch) {
+		case 'a':
+			adjust_clock = -1;
+			break;
 		case 's':
 			ubus_socket = optarg;
 			break;
diff --git a/nmea.c b/nmea.c
index 1a7ac27..275f39f 100644
--- a/nmea.c
+++ b/nmea.c
@@ -42,7 +42,7 @@
 #include "nmea.h"
 
 #define MAX_NMEA_PARAM	20
-#define MAX_TIME_OFFSET	2
+#define MAX_TIME_OFFSET	5
 #define MAX_BAD_TIME	3
 
 struct nmea_param {
@@ -51,7 +51,7 @@ struct nmea_param {
 } nmea_params[MAX_NMEA_PARAM];
 
 static int nmea_bad_time;
-char longitude[32] = { 0 }, latitude[32] = { 0 }, course[16] = { 0 }, speed[16] = { 0 }, elivation[16] = { 0 };
+char longitude[32] = { 0 }, latitude[32] = { 0 }, course[16] = { 0 }, speed[16] = { 0 }, elevation[16] = { 0 };
 int gps_valid = 0;
 
 static void
@@ -81,31 +81,36 @@ nmea_rmc_cb(void)
 	memset(&tm, 0, sizeof(tm));
 	tm.tm_isdst = 1;
 
-	if (!strptime(nmea_params[1].str, "%H%M%S", &tm))
-		ERROR("failed to parse time\n");
-	else if (!strptime(nmea_params[9].str, "%d%m%y", &tm))
-		ERROR("failed to parse date\n");
+	if (sscanf(nmea_params[1].str, "%02d%02d%02d",
+		&tm.tm_hour, &tm.tm_min, &tm.tm_sec) != 3) {
+		ERROR("failed to parse time '%s'\n", nmea_params[1].str);
+	}
+	else if (sscanf(nmea_params[9].str, "%02d%02d%02d",
+		&tm.tm_mday, &tm.tm_mon, &tm.tm_year) != 3) {
+		ERROR("failed to parse date '%s'\n", nmea_params[9].str);
+	}
 	else {
-		/* is there a libc api for the tz adjustment ? */
-		struct timeval tv = { mktime(&tm), 0 };
-		struct timeval cur;
+		tm.tm_year += 100; /* year starts with 1900 */
+		tm.tm_mon -= 1; /* month starts with 0 */
 
-		strftime(tmp, 256, "%D %02H:%02M:%02S", &tm);
+		strftime(tmp, 256, "%Y-%m-%dT%H:%M:%S", &tm);
 		DEBUG(3, "date: %s UTC\n", tmp);
 
-		tv.tv_sec -= timezone;
-		if (daylight)
-			tv.tv_sec += 3600;
+		if (adjust_clock) {
+			struct timeval tv = { timegm(&tm), 0 };
+			struct timeval cur;
 
-		gettimeofday(&cur, NULL);
+			gettimeofday(&cur, NULL);
 
-		if (abs(cur.tv_sec - tv.tv_sec) > MAX_TIME_OFFSET) {
-			if (++nmea_bad_time > MAX_BAD_TIME) {
-				LOG("system time differs from GPS time by more than %d seconds. Using %s UTC as the new time\n", MAX_TIME_OFFSET, tmp);
-				settimeofday(&tv, NULL);
+			if (abs(cur.tv_sec - tv.tv_sec) > MAX_TIME_OFFSET) {
+				if (++nmea_bad_time > MAX_BAD_TIME) {
+					LOG("system time differs from GPS time by more than %d seconds. Using %s UTC as the new time\n", MAX_TIME_OFFSET, tmp);
+					/* only set datetime if specified by command line argument! */
+					settimeofday(&tv, NULL);
+				}
+			} else {
+				nmea_bad_time = 0;
 			}
-		} else {
-			nmea_bad_time = 0;
 		}
 	}
 
@@ -144,8 +149,8 @@ nmea_gga_cb(void)
 {
 	if (!gps_valid)
 		return;
-	strncpy(elivation, nmea_params[9].str, sizeof(elivation));
-	DEBUG(4, "height: %s\n", elivation);
+	strncpy(elevation, nmea_params[9].str, sizeof(elevation));
+	DEBUG(4, "height: %s\n", elevation);
 }
 
 static void
diff --git a/nmea.h b/nmea.h
index 641f49e..c6f1896 100644
--- a/nmea.h
+++ b/nmea.h
@@ -23,8 +23,9 @@
 
 #include <libubox/ustream.h>
 
-extern char longitude[32], latitude[32], course[16], speed[16], elivation[16];
+extern char longitude[32], latitude[32], course[16], speed[16], elevation[16];
 extern int nmea_open(char *dev, struct ustream_fd *s, speed_t speed);
 extern void gps_timestamp(void);
+extern unsigned int adjust_clock;
 
 #endif