logger: permit to send messages larger than 1024 characters

This is an important capability that has been specified in RFC5424.
However, messages larger than 1024 chars are being accepted for years
now by at least rsyslog and syslog-ng.

This patch adds the option --size to permit setting a new max
size, with 1024 being the default.

Note that the size limit is only approximative, as we do not take the
header size in account (RFC talks about total message length).

[[kzak@redhat.com: - add 'S' to getopt_long(),
                   - rename --message-size to --size
                   - add the option to bash-completion]

Signed-off-by: Karel Zak <kzak@redhat.com>

1 files changed, 16 insertions, 7 deletions

diff --git a/misc-utils/logger.c b/misc-utils/logger.c
index 24cbb3b0b..3740c2e84 100644
--- a/misc-utils/logger.c
+++ b/misc-utils/logger.c
@@ -102,6 +102,7 @@ struct logger_ctl {
 	char *server;
 	char *port;
 	int socket_type;
+	size_t max_message_size;
 	void (*syslogfp)(const struct logger_ctl *ctl, const char *msg);
 	unsigned int
 			unix_socket_errors:1,	/* whether to report or not errors */
@@ -374,7 +375,7 @@ static void syslog_rfc3164(const struct logger_ctl *ctl, const char *msg)
 	if (dot)
 		*dot = '\0';
 
-	len = xasprintf(&buf, "<%d>%.15s %s %.200s%s: %.400s",
+	len = xasprintf(&buf, "<%d>%.15s %s %.200s%s: %s",
 		 ctl->pri, rfc3164_current_time(), hostname, cp, pid, msg);
 
 	write_output(ctl, buf, len);
@@ -522,9 +523,9 @@ static void logger_open(struct logger_ctl *ctl)
 
 static void logger_command_line(const struct logger_ctl *ctl, char **argv)
 {
-	char buf[4096];
+	char *const buf = xmalloc(ctl->max_message_size + 1);
 	char *p = buf;
-	const char *endp = buf + sizeof(buf) - 2;
+	const char *endp = buf + ctl->max_message_size - 1;
 	size_t len;
 
 	while (*argv) {
@@ -533,7 +534,8 @@ static void logger_command_line(const struct logger_ctl *ctl, char **argv)
 			ctl->syslogfp(ctl, buf);
 			p = buf;
 		}
-		if (sizeof(buf) - 1 < len) {
+		if (ctl->max_message_size < len) {
+			(*argv)[ctl->max_message_size] = '\0'; /* truncate */
 			ctl->syslogfp(ctl, *argv++);
 			continue;
 		}
@@ -550,9 +552,9 @@ static void logger_stdin(struct logger_ctl *ctl)
 {
 	char *msg;
 	int default_priority = ctl->pri;
-	char buf[1024];
+	char *const buf = xmalloc(ctl->max_message_size + 2);
 
-	while (fgets(buf, sizeof(buf), stdin) != NULL) {
+	while (fgets(buf, ctl->max_message_size+2, stdin) != NULL) {
 		int len = strlen(buf);
 
 		/* some glibc versions are buggy, they add an additional
@@ -588,6 +590,7 @@ static void __attribute__ ((__noreturn__)) usage(FILE *out)
 	fputs(_(" -p, --priority <prio>    mark given message with this priority\n"), out);
 	fputs(_("     --prio-prefix        look for a prefix on every line read from stdin\n"), out);
 	fputs(_(" -s, --stderr             output message to standard error as well\n"), out);
+	fputs(_(" -S, --size <size>        maximum size for a single message\n"), out);
 	fputs(_(" -t, --tag <tag>          mark every line with this tag\n"), out);
 	fputs(_(" -n, --server <name>      write to this remote syslog server\n"), out);
 	fputs(_(" -P, --port <number>      use this UDP port\n"), out);
@@ -630,6 +633,7 @@ int main(int argc, char **argv)
 		.server = NULL,
 		.port = NULL,
 		.socket_type = ALL_TYPES,
+		.max_message_size = 1024,
 		.rfc5424_time = 1,
 		.rfc5424_tq = 1,
 		.rfc5424_host = 1,
@@ -657,6 +661,7 @@ int main(int argc, char **argv)
 		{ "prio-prefix", no_argument, 0, OPT_PRIO_PREFIX },
 		{ "rfc3164",	no_argument,  0, OPT_RFC3164 },
 		{ "rfc5424",	optional_argument,  0, OPT_RFC5424 },
+		{ "size",       required_argument,  0, 'S' },
 #ifdef HAVE_LIBSYSTEMD
 		{ "journald",   optional_argument,  0, OPT_JOURNALD },
 #endif
@@ -668,7 +673,7 @@ int main(int argc, char **argv)
 	textdomain(PACKAGE);
 	atexit(close_stdout);
 
-	while ((ch = getopt_long(argc, argv, "f:ip:st:u:dTn:P:Vh",
+	while ((ch = getopt_long(argc, argv, "f:ip:S:st:u:dTn:P:Vh",
 					    longopts, NULL)) != -1) {
 		switch (ch) {
 		case 'f':		/* file to log */
@@ -701,6 +706,10 @@ int main(int argc, char **argv)
 		case 'u':		/* unix socket */
 			ctl.unix_socket = optarg;
 			break;
+		case 'S':		/* max message size */
+			ctl.max_message_size = strtosize_or_err(optarg,
+				_("failed to parse message size"));
+			break;
 		case 'd':
 			ctl.socket_type = TYPE_UDP;
 			break;