ninfod: Do not mix output from multiple threads.

- setbuf(stderr, NULL)
- write a line at once (by vsnprintf + fputs);
- No expcicit locks.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

4 files changed, 54 insertions, 2 deletions

diff --git a/ninfod/config.h.in b/ninfod/config.h.in
index 4bdb50a..10ff9a2 100644
--- a/ninfod/config.h.in
+++ b/ninfod/config.h.in
@@ -24,6 +24,9 @@
 /* Define to 1 if you have the `pthread' library (-lpthread). */
 #undef HAVE_LIBPTHREAD
 
+/* Define to 1 if you have the <limits.h> header file. */
+#undef HAVE_LIMITS_H
+
 /* Define to 1 if you have the <linux/rtnetlink.h> header file. */
 #undef HAVE_LINUX_RTNETLINK_H
 
diff --git a/ninfod/configure b/ninfod/configure
index 4b69014..deba361 100755
--- a/ninfod/configure
+++ b/ninfod/configure
@@ -3535,6 +3535,18 @@ fi
 done
 
 
+for ac_header in limits.h
+do :
+  ac_fn_c_check_header_mongrel "$LINENO" "limits.h" "ac_cv_header_limits_h" "$ac_includes_default"
+if test "x$ac_cv_header_limits_h" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LIMITS_H 1
+_ACEOF
+
+fi
+
+done
+
 for ac_header in openssl/md5.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "openssl/md5.h" "ac_cv_header_openssl_md5_h" "$ac_includes_default"
diff --git a/ninfod/configure.in b/ninfod/configure.in
index f33b77d..99f8da0 100644
--- a/ninfod/configure.in
+++ b/ninfod/configure.in
@@ -76,6 +76,7 @@ dnl Checks for libraries.
 dnl Checks for header files.
 AC_HEADER_STDC
 AC_HEADER_TIME
+AC_CHECK_HEADERS(limits.h)
 AC_CHECK_HEADERS(openssl/md5.h)
 AC_CHECK_HEADERS(sys/uio.h)
 AC_CHECK_HEADERS(sys/utsname.h arpa/inet.h netdb.h syslog.h)
diff --git a/ninfod/ninfod.c b/ninfod/ninfod.c
index bc4a23e..c8a581d 100644
--- a/ninfod/ninfod.c
+++ b/ninfod/ninfod.c
@@ -66,6 +66,9 @@
 #  include <stdint.h>
 # endif
 #endif
+#if HAVE_LIMITS_H
+# include <limits.h>
+#endif
 #if HAVE_UNISTD_H
 # include <unistd.h>
 #endif
@@ -149,9 +152,40 @@ static const __inline__ char * log_level(int priority) {
 void stderrlog(int pri, char *fmt, ...)
 {
 	va_list ap;
+	char *buf = NULL;
+	size_t buflen = 1;
+
 	va_start(ap, fmt);
-	fprintf(stderr, "[%s] ", log_level(pri));
-	vfprintf(stderr, fmt, ap);
+
+	for (buf = NULL, buflen = 1024;
+	     buflen < SIZE_MAX / 2;
+	     free(buf), buf = NULL, buflen *= 2) {
+		size_t rem;
+		size_t res;
+
+		buf = malloc(buflen);
+		if (!buf)
+			break;	/*XXX*/
+
+		rem = buflen;
+
+		res = snprintf(buf, rem, "[%s] ", log_level(pri));
+		if (res >= rem)
+			continue;
+		rem -= res;
+
+		res = vsnprintf(buf + res, rem, fmt, ap);
+
+		if (res >= rem)
+			continue;
+		break;
+	}
+
+	if (buf) {
+		fputs(buf, stderr);
+		free(buf);
+	}
+
 	va_end(ap);
 }
 #endif
@@ -613,6 +647,8 @@ int main (int argc, char **argv)
 		exit(1);
 	}
 
+	setbuf(stderr, NULL);
+
 	if (!opt_d)
 		do_daemonize();