vchan-socket-proxy: Move perror() into listen_socket

The use of perror on the return from listen_socket can produce
misleading results like:
UNIX socket path "/tmp/aa....aa" too long (156 >= 108)
listen socket: Success

errno is reset by subsequent system & library calls, so it may be
inaccurate by the time listen_socket returns.  Call perror immediately
after failing system calls to print the proper message.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Wei Liu <wl@xen.org>
Reviewed-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Release-acked-by: Paul Durrant <paul@xen.org>

diff --git a/tools/libvchan/vchan-socket-proxy.c b/tools/libvchan/vchan-socket-proxy.c
index 6ae1d841435452d5b632d0d1784f948dbbd39189..4edc3a44f5a88e6dd8b765091cdc2e63a2dfb183 100644 (file)
--- a/tools/libvchan/vchan-socket-proxy.c
+++ b/tools/libvchan/vchan-socket-proxy.c
@@ -188,16 +188,20 @@ static int listen_socket(const char *path_or_fd) {
 
     /* if not a number, assume a socket path */
     fd = socket(AF_UNIX, SOCK_STREAM, 0);
-    if (fd == -1)
+    if (fd == -1) {
+        perror("socket");
         return -1;
+    }
 
     addr.sun_family = AF_UNIX;
     strcpy(addr.sun_path, path_or_fd);
     if (bind(fd, (const struct sockaddr *)&addr, sizeof(addr)) == -1) {
+        perror("bind");
         close(fd);
         return -1;
     }
     if (listen(fd, 5) != 0) {
+        perror("listen");
         close(fd);
         return -1;
     }
@@ -419,7 +423,7 @@ int main(int argc, char **argv)
         } else {
             socket_fd = listen_socket(socket_path);
             if (socket_fd == -1) {
-                perror("listen socket");
+                fprintf(stderr, "listen socket failed\n");
                 return 1;
             }
         }