log: Add _perror() logging function variants

In many places, we have direct perror() calls, which completely bypass
logging functions and log files.

They are definitely convenient: offer similar convenience with
_perror() logging variants, so that we can drop those direct perror()
calls.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 22 insertions, 0 deletions

diff --git a/log.c b/log.c
index 0199eb4..7182acb 100644
--- a/log.c
+++ b/log.c
@@ -78,6 +78,11 @@ void vlogmsg(int pri, const char *format, va_list ap)
 	}
 }
 
+/**
+ * logmsg() - vlogmsg() wrapper for variable argument lists
+ * @pri:	Facility and level map, same as priority for vsyslog()
+ * @format:	Message
+ */
 void logmsg(int pri, const char *format, ...)
 {
 	va_list ap;
@@ -87,6 +92,23 @@ void logmsg(int pri, const char *format, ...)
 	va_end(ap);
 }
 
+/**
+ * logmsg_perror() - vlogmsg() wrapper with perror()-like functionality
+ * @pri:	Facility and level map, same as priority for vsyslog()
+ * @format:	Message
+ */
+void logmsg_perror(int pri, const char *format, ...)
+{
+	int errno_copy = errno;
+	va_list ap;
+
+	va_start(ap, format);
+	vlogmsg(pri, format, ap);
+	va_end(ap);
+
+	logmsg(pri, ": %s", strerror(errno_copy));
+}
+
 /* Prefixes for log file messages, indexed by priority */
 const char *logfile_prefix[] = {
 	NULL, NULL, NULL,	/* Unused: LOG_EMERG, LOG_ALERT, LOG_CRIT */