implement the LOG_CONS option in syslog

this was previously a no-op, somewhat intentionally, because I failed
to understand that it only has an effect when sending to the logging
facility fails and thus is not the nuisance that it would be if always
sent output to the console.

1 files changed, 9 insertions, 1 deletions

diff --git a/src/misc/syslog.c b/src/misc/syslog.c
index 6d2a864a..fdf90ba9 100644
--- a/src/misc/syslog.c
+++ b/src/misc/syslog.c
@@ -8,6 +8,7 @@
 #include <string.h>
 #include <pthread.h>
 #include <errno.h>
+#include <fcntl.h>
 #include "libc.h"
 #include "atomic.h"
 
@@ -81,6 +82,7 @@ static void _vsyslog(int priority, const char *message, va_list ap)
 	int pid;
 	int l, l2;
 	int hlen;
+	int fd;
 
 	if (log_fd < 0) __openlog();
 
@@ -99,7 +101,13 @@ static void _vsyslog(int priority, const char *message, va_list ap)
 		if (l2 >= sizeof buf - l) l = sizeof buf - 1;
 		else l += l2;
 		if (buf[l-1] != '\n') buf[l++] = '\n';
-		send(log_fd, buf, l, 0);
+		if (send(log_fd, buf, l, 0) < 0 && (log_opt & LOG_CONS)) {
+			fd = open("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
+			if (fd >= 0) {
+				dprintf(fd, "%.*s", l-hlen, buf+hlen);
+				close(fd);
+			}
+		}
 		if (log_opt & LOG_PERROR) dprintf(2, "%.*s", l-hlen, buf+hlen);
 	}
 }