2005-02-16 Andrew J. Schorr <ajschorr@alumni.princeton.edu>

	* network.c: (set_nonblocking) Should check return code from
	  fcntl(F_GETFL).

1 files changed, 11 insertions, 1 deletions

diff --git a/lib/network.c b/lib/network.c
index 3b296720..3373983b 100644
--- a/lib/network.c
+++ b/lib/network.c
@@ -75,7 +75,17 @@ writen(int fd, const u_char *ptr, int nbytes)
 int
 set_nonblocking(int fd)
 {
-  if (fcntl(fd, F_SETFL, (fcntl(fd, F_GETFL) | O_NONBLOCK)) < 0)
+  int flags;
+
+  /* According to the Single UNIX Spec, the return value for F_GETFL should
+     never be negative. */
+  if ((flags = fcntl(fd, F_GETFL)) < 0)
+    {
+      zlog_warn("fcntl(F_GETFL) failed for fd %d: %s",
+      		fd, safe_strerror(errno));
+      return -1;
+    }
+  if (fcntl(fd, F_SETFL, (flags | O_NONBLOCK)) < 0)
     {
       zlog_warn("fcntl failed setting fd %d non-blocking: %s",
       		fd, safe_strerror(errno));