Merge branch 'logger-fix-tcp-framing' of https://github.com/rgerhards/util-linux

* 'logger-fix-tcp-framing' of https://github.com/rgerhards/util-linux:
  logger: bugfix: tcp syslog framing is broken, -T unusable
  logger: refactor the way output is written

1 files changed, 27 insertions, 13 deletions

diff --git a/misc-utils/logger.c b/misc-utils/logger.c
index 308db8b34d..24cbb3b0b4 100644
--- a/misc-utils/logger.c
+++ b/misc-utils/logger.c
@@ -332,6 +332,30 @@ rfc3164_current_time(void)
 	return time;
 }
 
+/* writes generated buffer to desired destination. For TCP syslog,
+ * we use RFC6587 octet-stuffing. This is not great, but doing
+ * full blown RFC5425 (TLS) looks like it is too much for the
+ * logger utility.
+ */
+static void write_output(const struct logger_ctl *ctl, const char *const buf,
+	const size_t len)
+{
+	if (write_all(ctl->fd, buf, len) < 0)
+		warn(_("write failed"));
+	else
+		if (ctl->socket_type == TYPE_TCP)
+			/* using an additional write seems like the best compromise:
+			 * - writev() is not yet supported by framework
+			 * - adding the \n to the buffer in formatters violates layers
+			 * - adding \n after the fact requires memory copy
+			 * - logger is not a high-performance app
+			 */
+			if (write_all(ctl->fd, "\n", 1) < 0)
+				warn(_("write failed"));
+	if (ctl->stderr_printout)
+		fprintf(stderr, "%s\n", buf);
+}
+
 static void syslog_rfc3164(const struct logger_ctl *ctl, const char *msg)
 {
 	char *buf, pid[30], *cp, *hostname, *dot;
@@ -353,10 +377,7 @@ static void syslog_rfc3164(const struct logger_ctl *ctl, const char *msg)
 	len = xasprintf(&buf, "<%d>%.15s %s %.200s%s: %.400s",
 		 ctl->pri, rfc3164_current_time(), hostname, cp, pid, msg);
 
-	if (write_all(ctl->fd, buf, len) < 0)
-		warn(_("write failed"));
-	if (ctl->stderr_printout)
-		fprintf(stderr, "%s\n", buf);
+	write_output(ctl, buf, len);
 
 	free(hostname);
 	free(buf);
@@ -427,11 +448,7 @@ static void syslog_rfc5424(const  struct logger_ctl *ctl, const char *msg)
 		  hostname ? hostname : "",
 		  tag, pid, timeq, msg);
 
-	if (write_all(ctl->fd, buf, len) < 0)
-		warn(_("write failed"));
-
-	if (ctl->stderr_printout)
-		fprintf(stderr, "%s\n", buf);
+	write_output(ctl, buf, len);
 
 	free(hostname);
 	free(buf);
@@ -483,10 +500,7 @@ static void syslog_local(const struct logger_ctl *ctl, const char *msg)
 
 	len = xasprintf(&buf, "<%d>%s %s%s: %s", ctl->pri, rfc3164_current_time(),
 		tag, pid, msg);
-	if (write_all(ctl->fd, buf, len) < 0)
-		warn(_("write failed"));
-	if (ctl->stderr_printout)
-		fprintf(stderr, "%s\n", buf);
+	write_output(ctl, buf, len);
 	free(buf);
 }