Hack around short writes

Actual netconsole packets can be shorter than a line.  So instead of
creating a new line plus timestamp for every fragment, remember whether
we had a newline before and only add a timestamp in those cases.

Currently this is still semi-broken.  We have no memory across packets,
so timestamps are never printed for the first line of a packet.

Signed-off-by: Joern Engel <joern@logfs.org>

1 files changed, 15 insertions, 6 deletions

diff --git a/cancd.c b/cancd.c
index 4d79a3d..8c58b1c 100644
--- a/cancd.c
+++ b/cancd.c
@@ -305,6 +305,7 @@ static int write_formatted(int fd, char *buf, int count)
 	size_t n, len, err;
 	time_t now = time(NULL);
 	struct tm *tm = localtime(&now);
+	int had_newline = 0;
 
 	/*
 	 * buf must be NUL-terminated.  We add 1 to count for the terminating
@@ -313,18 +314,26 @@ static int write_formatted(int fd, char *buf, int count)
 	 */
 	count += 1;
 	while (count > 1) {
-		end = strchrnul(buf, 0xa);
-		*end = 0xa;
+		if (had_newline) {
+			n = strftime(timestr, sizeof(timestr), format, tm);
+			err = do_write(fd, timestr, n);
+			if (err)
+				return err;
+		}
+		end = strchr(buf, 0xa);
+		if (!end) {
+			/* no newline, just write what we have */
+			do_write(fd, buf, count - 1);
+			had_newline = 0;
+			break;
+		}
 		len = end - buf + 1;
-		n = strftime(timestr, sizeof(timestr), format, tm);
-		err = do_write(fd, timestr, n);
-		if (err)
-			return err;
 		err = do_write(fd, buf, len);
 		if (err)
 			return err;
 		buf += len;
 		count -= len;
+		had_newline = 1;
 	}
 	return 0;
 }