Add options to tag ptp4l and phc2sys log messages.

When running multiple instances of ptp4l or phc2sys, it's difficult to
tell which log message belongs to which instance. Add new options to
ptp4l and phc2sys which can specify a tag for all messages printed to
the standard output or system log, so messages from different instances
can have different tags.

Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>

config.c

@@ -199,6 +199,7 @@ struct config_item config_tab[] = {
 	PORT_ITEM_INT("logMinPdelayReqInterval", 0, INT8_MIN, INT8_MAX),
 	PORT_ITEM_INT("logSyncInterval", 0, INT8_MIN, INT8_MAX),
 	GLOB_ITEM_INT("logging_level", LOG_INFO, PRINT_LEVEL_MIN, PRINT_LEVEL_MAX),
+	GLOB_ITEM_STR("message_tag", NULL),
 	GLOB_ITEM_STR("manufacturerIdentity", "00:00:00"),
 	GLOB_ITEM_INT("max_frequency", 900000000, 0, INT_MAX),
 	PORT_ITEM_INT("min_neighbor_prop_delay", -20000000, INT_MIN, -1),

phc2sys.8

@@ -206,6 +206,10 @@ The default is /var/run/ptp4l.
 Set the maximum syslog level of messages which should be printed or sent to
 the system logger. The default is 6 (LOG_INFO).
 .TP
+.BI \-t " message-tag"
+Specify the tag which is added to all messages printed to the standard output
+or system log. The default is an empty string.
+.TP
 .B \-m
 Print messages to the standard output.
 .TP

phc2sys.c

@@ -1209,6 +1209,7 @@ static void usage(char *progname)
 		" -x             apply leap seconds by servo instead of kernel\n"
 		" -z [path]      server address for UDS (/var/run/ptp4l)\n"
 		" -l [num]       set the logging level to 'num' (6)\n"
+		" -t [tag]       add tag to log messages\n"
 		" -m             print messages to stdout\n"
 		" -q             do not print messages to the syslog\n"
 		" -v             prints the software version and exits\n"
@@ -1219,7 +1220,7 @@ static void usage(char *progname)
 
 int main(int argc, char *argv[])
 {
-	char *progname;
+	char *progname, *message_tag = NULL;
 	char *src_name = NULL, *dst_name = NULL;
 	struct clock *src, *dst;
 	struct config *cfg;
@@ -1251,7 +1252,7 @@ int main(int argc, char *argv[])
 	progname = strrchr(argv[0], '/');
 	progname = progname ? 1+progname : argv[0];
 	while (EOF != (c = getopt(argc, argv,
-				  "arc:d:s:E:P:I:S:F:R:N:O:L:M:i:u:wn:xz:l:mqvh"))) {
+				  "arc:d:s:E:P:I:S:F:R:N:O:L:M:i:u:wn:xz:l:t:mqvh"))) {
 		switch (c) {
 		case 'a':
 			autocfg = 1;
@@ -1363,6 +1364,9 @@ int main(int argc, char *argv[])
 					  PRINT_LEVEL_MIN, PRINT_LEVEL_MAX))
 				goto end;
 			break;
+		case 't':
+			message_tag = optarg;
+			break;
 		case 'm':
 			verbose = 1;
 			break;
@@ -1405,6 +1409,7 @@ int main(int argc, char *argv[])
 	}
 
 	print_set_progname(progname);
+	print_set_tag(message_tag);
 	print_set_verbose(verbose);
 	print_set_syslog(use_syslog);
 	print_set_level(print_level);

print.c

@@ -28,12 +28,18 @@ static int verbose = 0;
 static int print_level = LOG_INFO;
 static int use_syslog = 1;
 static const char *progname;
+static const char *message_tag;
 
 void print_set_progname(const char *name)
 {
 	progname = name;
 }
 
+void print_set_tag(const char *tag)
+{
+	message_tag = tag;
+}
+
 void print_set_syslog(int value)
 {
 	use_syslog = value ? 1 : 0;
@@ -67,13 +73,17 @@ void print(int level, char const *format, ...)
 
 	if (verbose) {
 		f = level >= LOG_NOTICE ? stdout : stderr;
-		fprintf(f, "%s[%ld.%03ld]: %s\n",
+		fprintf(f, "%s[%ld.%03ld]: %s%s%s\n",
 			progname ? progname : "",
-			ts.tv_sec, ts.tv_nsec / 1000000, buf);
+			ts.tv_sec, ts.tv_nsec / 1000000,
+			message_tag ? message_tag : "", message_tag ? " " : "",
+			buf);
 		fflush(f);
 	}
 	if (use_syslog) {
-		syslog(level, "[%ld.%03ld] %s",
-		       ts.tv_sec, ts.tv_nsec / 1000000, buf);
+		syslog(level, "[%ld.%03ld] %s%s%s",
+		       ts.tv_sec, ts.tv_nsec / 1000000,
+		       message_tag ? message_tag : "", message_tag ? " " : "",
+		       buf);
 	}
 }

print.h

@@ -33,6 +33,7 @@ __attribute__ ((format (printf, 2, 3)))
 void print(int level, char const *format, ...);
 
 void print_set_progname(const char *name);
+void print_set_tag(const char *tag);
 void print_set_syslog(int value);
 void print_set_level(int level);
 void print_set_verbose(int value);

ptp4l.8

@@ -485,6 +485,12 @@ is 0.
 The maximum logging level of messages which should be printed.
 The default is 6 (LOG_INFO).
 .TP
+.B message_tag
+The tag which is added to all messages printed to the standard output or system
+log.
+The default is an empty string (which cannot be set in the configuration file
+as the option requires an argument).
+.TP
 .B verbose
 Print messages to the standard output if enabled.
 The default is 0 (disabled).

ptp4l.c

@@ -183,6 +183,7 @@ int main(int argc, char *argv[])
 	}
 
 	print_set_progname(progname);
+	print_set_tag(config_get_string(cfg, NULL, "message_tag"));
 	print_set_verbose(config_get_int(cfg, NULL, "verbose"));
 	print_set_syslog(config_get_int(cfg, NULL, "use_syslog"));
 	print_set_level(config_get_int(cfg, NULL, "logging_level"));