From: Harlan Stenn <stenn@ntp.org>
Date: Wed, 8 Dec 2010 07:34:17 +0000 (-0500)
Subject: [Bug 1743] Display timezone offset when showing time for sntp in the local timezone.
X-Git-Tag: NTP_4_2_7P92~1^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d65be755460867d58008f7c73bd5a334890aa942;p=thirdparty%2Fntp.git

[Bug 1743] Display timezone offset when showing time for sntp in the local timezone.

bk: 4cff34f9pmtl-zCnAmh_mnil7vEJCA
---

diff --git a/ChangeLog b/ChangeLog
index f7cffd2c2..ae8d367f7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,8 @@
 ---
 
 * [Bug 1742] Fix a typo in an error message in the "build" script.
+* [Bug 1743] Display timezone offset when showing time for sntp in the
+  local timezone.
 * Clean up m4 quoting in configure.ac, *.m4 files, resolving
   intermittent AC_LANG_PROGRAM possibly undefined errors.
 * Clean up the SNTP documentation.
diff --git a/sntp/configure.ac b/sntp/configure.ac
index 0b34eed7c..d05d53600 100644
--- a/sntp/configure.ac
+++ b/sntp/configure.ac
@@ -237,6 +237,7 @@ AC_HEADER_TIME
 AC_HEADER_STDBOOL
 AC_C_CONST
 AC_TYPE_SIZE_T
+AC_CHECK_SIZEOF([time_t])
 
 AC_C_INLINE
 
diff --git a/sntp/main.c b/sntp/main.c
index ef7f11457..6ce262536 100644
--- a/sntp/main.c
+++ b/sntp/main.c
@@ -199,6 +199,8 @@ handle_pkt (
 	char *hostname = NULL, *ref, *ts_str = NULL;
 	double offset, precision, root_dispersion;
 	char addr_buf[INET6_ADDRSTRLEN];
+	char *p_SNTP_PRETEND_TIME;
+	time_t pretend_time;
 
 	if(rpktl > 0)
 		sw_case = 1;
@@ -243,9 +245,21 @@ handle_pkt (
 		}
 
 		GETTIMEOFDAY(&tv_dst, (struct timezone *)NULL);
-		tv_dst.tv_sec += JAN_1970;
 
-		offset_calculation(rpkt, rpktl, &tv_dst, &offset, &precision, &root_dispersion);
+		p_SNTP_PRETEND_TIME = getenv("SNTP_PRETEND_TIME");
+		if (p_SNTP_PRETEND_TIME) {
+#if SIZEOF_TIME_T == 4
+			sscanf(p_SNTP_PRETEND_TIME, "%ld", &pretend_time);
+#elif SIZEOF_TIME_T == 8
+			sscanf(p_SNTP_PRETEND_TIME, "%lld", &pretend_time);
+#else
+# include "GRONK: unexpected value for SIZEOF_TIME_T"
+#endif
+			tv_dst.tv_sec = pretend_time;
+		}
+
+		offset_calculation(rpkt, rpktl, &tv_dst, &offset,
+				   &precision, &root_dispersion);
 
 		for (digits = 0; (precision *= 10.) < 1.; ++digits)
 			/* empty */ ;
@@ -262,6 +276,9 @@ handle_pkt (
 		printf("\n");
 		free(ts_str);
 
+		if (p_SNTP_PRETEND_TIME)
+			return 0;
+
 		if (ENABLED_OPT(SETTOD) || ENABLED_OPT(ADJTIME))
 			return set_time(offset); 
 
@@ -325,6 +342,7 @@ offset_calculation (
 	L_SUB(&tmp, &p_org);
 	LFPTOD(&tmp, t21);
 	TVTOTS(tv_dst, &dst);
+	dst.l_ui += JAN_1970;
 	tmp = p_xmt;
 	L_SUB(&tmp, &dst);
 	LFPTOD(&tmp, t34);
diff --git a/sntp/utilities.c b/sntp/utilities.c
index 6180ecb7a..e19ee1c35 100644
--- a/sntp/utilities.c
+++ b/sntp/utilities.c
@@ -1,5 +1,6 @@
 #include <config.h>
 #include "utilities.h"
+#include <assert.h>
 
 /* Display a NTP packet in hex with leading address offset 
  * e.g. offset: value, 0: ff 1: fe ... 255: 00
@@ -139,34 +140,47 @@ ss_to_str (
 
 	return buf;
 }
-
-/* Converts a struct tv to a date string
+/*
+ * Converts a struct tv to a date string
  */
 char *
-tv_to_str (
-		struct timeval *tv
-	  )
+tv_to_str(
+	const struct timeval *tv
+	)
 {
-	static const char *month_names[] = {
-		"Jan", "Feb", "Mar", "Apr", "May", "Jun",
-		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
-	};
-
-	char *buf = (char *) emalloc(sizeof(char) * 48);
-	time_t cur_time = time(NULL);
-	struct tm *tm_ptr;
-
-	tm_ptr = localtime(&cur_time);
-
-
-	snprintf(buf, 48, "%i %s %.2d %.2d:%.2d:%.2d.%.6d", 
-			tm_ptr->tm_year + 1900,
-			month_names[tm_ptr->tm_mon],
-			tm_ptr->tm_mday,
-			tm_ptr->tm_hour,
-			tm_ptr->tm_min,
-			tm_ptr->tm_sec,
-			(int)tv->tv_usec);
+	const size_t bufsize = 48;
+	char *buf;
+	time_t gmt_time, local_time;
+	struct tm *p_tm_local;
+	int hh, mm, lto;
+
+	/*
+	 * convert to struct tm in UTC, then intentionally feed
+	 * that tm to mktime() which expects local time input, to
+	 * derive the offset from UTC to local time.
+	 */
+	gmt_time = tv->tv_sec;
+	local_time = mktime(gmtime(&gmt_time));
+	p_tm_local = localtime(&gmt_time);
+
+	/* Local timezone offsets should never cause an overflow.  Yeah. */
+	lto = difftime(local_time, gmt_time);
+	lto /= 60;
+	hh = lto / 60;
+	mm = abs(lto % 60);
+
+	buf = emalloc(bufsize);
+	snprintf(buf, bufsize,
+		 "%d-%.2d-%.2d %.2d:%.2d:%.2d.%.6d (%+03d%02d)",
+		 p_tm_local->tm_year + 1900,
+		 p_tm_local->tm_mon + 1,
+		 p_tm_local->tm_mday,
+		 p_tm_local->tm_hour,
+		 p_tm_local->tm_min,
+		 p_tm_local->tm_sec,
+		 (int)tv->tv_usec,
+		 hh,
+		 mm);
 
 	return buf;
 }
diff --git a/sntp/utilities.h b/sntp/utilities.h
index 79fd77477..a122f868d 100644
--- a/sntp/utilities.h
+++ b/sntp/utilities.h
@@ -20,6 +20,6 @@ void l_fp_output_dec (l_fp *ts, FILE *output);
 
 char *addrinfo_to_str (struct addrinfo *addr);
 char *ss_to_str (sockaddr_u *saddr);
-char *tv_to_str (struct timeval *tv);
+char *tv_to_str (const struct timeval *tv);
 
 #endif