<command> | nc seashells.io 1337Some syslog() implementations like musl's always send timestamps in UTC.
The following code adds a new option to syslogd, -Z, to assume incoming
timestamps are always UTC, and to adjust them to the local timezone
(of the syslogd) before logging.
Signed-off-by: Shiz <hi at shiz.me>
---
sysklogd/syslogd.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
diff --git a/sysklogd/syslogd.c b/sysklogd/syslogd.c
index d64ff27..159336e 100644
--- a/sysklogd/syslogd.c
+++ b/sysklogd/syslogd.c
@@ -122,6 +122,7 @@
//usage: "(this version of syslogd ignores /etc/syslog.conf)\n"
//usage: )
//usage: "\n -n Run in foreground"
+//usage: "\n -Z Adjust incoming UTC times to local time"
//usage: IF_FEATURE_REMOTE_LOG(
//usage: "\n -R HOST[:PORT] Log to HOST:PORT (default PORT:514)"
//usage: "\n -L Log locally and via network (default is network only if -R)"
@@ -233,6 +234,8 @@ typedef struct logRule_t {
/*int markInterval;*/ \
/* level of messages to be logged */ \
int logLevel; \
+ /* whether to adjust message timezone */\
+ int adjustTimezone; \
IF_FEATURE_ROTATE_LOGFILE( \
/* max size of file before rotation */ \
unsigned logFileSize; \
@@ -316,6 +319,7 @@ enum {
OPTBIT_outfile, // -O
OPTBIT_loglevel, // -l
OPTBIT_small, // -S
+ OPTBIT_adjusttz, // -Z
IF_FEATURE_ROTATE_LOGFILE(OPTBIT_filesize ,) // -s
IF_FEATURE_ROTATE_LOGFILE(OPTBIT_rotatecnt ,) // -b
IF_FEATURE_REMOTE_LOG( OPTBIT_remotelog ,) // -R
@@ -330,6 +334,7 @@ enum {
OPT_outfile = 1 << OPTBIT_outfile ,
OPT_loglevel = 1 << OPTBIT_loglevel,
OPT_small = 1 << OPTBIT_small ,
+ OPT_adjusttz = 1 << OPTBIT_adjusttz,
OPT_filesize = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_filesize )) + 0,
OPT_rotatecnt = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_rotatecnt )) + 0,
OPT_remotelog = IF_FEATURE_REMOTE_LOG( (1 << OPTBIT_remotelog )) + 0,
@@ -339,7 +344,7 @@ enum {
OPT_cfg = IF_FEATURE_SYSLOGD_CFG( (1 << OPTBIT_cfg )) + 0,
OPT_kmsg = IF_FEATURE_KMSG_SYSLOG( (1 << OPTBIT_kmsg )) + 0,
};
-#define OPTION_STR "m:nO:l:S" \
+#define OPTION_STR "m:nO:l:SZ" \
IF_FEATURE_ROTATE_LOGFILE("s:" ) \
IF_FEATURE_ROTATE_LOGFILE("b:" ) \
IF_FEATURE_REMOTE_LOG( "R:*") \
@@ -815,17 +820,23 @@ static void timestamp_and_log(int pri, char *msg, int len)
{
char *timestamp;
time_t now;
+ struct tm nowtm = { .tm_isdst = 0 };
/* Jan 18 00:11:22 msg... */
/* 01234567890123456 */
if (len < 16 || msg[3] != ' ' || msg[6] != ' '
|| msg[9] != ':' || msg[12] != ':' || msg[15] != ' '
) {
- time(&now);
+ now = time(NULL);
timestamp = ctime(&now) + 4; /* skip day of week */
} else {
- now = 0;
- timestamp = msg;
+ if (G.adjustTimezone && strptime(msg, "%b %e %T", &nowtm)) {
+ now = mktime(&nowtm) - timezone;
+ timestamp = ctime(&now) + 4; /* skip day of week */
+ } else {
+ now = 0;
+ timestamp = msg;
+ }
msg += 16;
}
timestamp[15] = '\0';
@@ -1130,6 +1141,10 @@ int syslogd_main(int argc UNUSED_PARAM, char **argv)
if (opts & OPT_loglevel) // -l
G.logLevel = xatou_range(opt_l, 1, 8);
//if (opts & OPT_small) // -S
+ if (opts & OPT_adjusttz) { // -Z
+ G.adjustTimezone = 1;
+ tzset();
+ }
#if ENABLE_FEATURE_ROTATE_LOGFILE
if (opts & OPT_filesize) // -s
G.logFileSize = xatou_range(opt_s, 0, INT_MAX/1024) * 1024;
--