From: Mark Wooding <mdw@distorted.org.uk>
Date: Wed, 6 Jun 2018 19:10:14 +0000 (+0100)
Subject: noip.c (encode_..._inet_addr: Abstract out checking a single address.
X-Git-Tag: 1.2.0~22
X-Git-Url: https://git.distorted.org.uk/~mdw/preload-hacks/commitdiff_plain/81e3737d842818a305e23802405f4e15b5e8381d

noip.c (encode_..._inet_addr: Abstract out checking a single address.

There's this common pattern of building the Unix-domain socket address,
probing its status, maybe unlinking the socket if it's stale, and
returning the result.  Let's only write that once.

No functional change.
---

diff --git a/noip.c b/noip.c
index 8806d02..1d40850 100644
--- a/noip.c
+++ b/noip.c
@@ -679,6 +679,23 @@ done:
   return (rc);
 }
 
+/* Encode SA as a Unix-domain address SUN, and return whether it's currently
+ * in use.
+ */
+static int encode_single_inet_addr(const struct sockaddr *sa,
+				   struct sockaddr_un *sun,
+				   int quickp)
+{
+  char buf[ADDRBUFSZ];
+  int rc;
+
+  snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir,
+	   present_sockaddr(sa, 0, buf, sizeof(buf)));
+  if ((rc = unix_socket_status(sun, quickp)) == USED) return (USED);
+  else if (rc == STALE) unlink(sun->sun_path);
+  return (UNUSED);
+}
+
 /* Convert the IP address SA to a Unix-domain address SUN.  Fail if the
  * address seems already taken.  If DESPARATEP then try cleaning up stale old
  * sockets.
@@ -689,28 +706,22 @@ static int encode_unused_inet_addr(struct sockaddr *sa,
 {
   address waddr;
   struct sockaddr_un wsun;
-  int rc;
-  char buf[ADDRBUFSZ];
   int port = port_from_sockaddr(sa);
 
   /* First, look for an exact match.  Only look quickly unless we're
    * desperate.  If the socket is in use, we fail here.  (This could get
    * racy.  Let's not worry about that for now.)
    */
-  snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir,
-	   present_sockaddr(sa, 0, buf, sizeof(buf)));
-  if ((rc = unix_socket_status(sun, !desperatep)) == USED) return (-1);
-  else if (rc == STALE) unlink(sun->sun_path);
+  if (encode_single_inet_addr(sa, sun, !desperatep) == USED)
+    return (-1);
 
   /* Next, check the corresponding wildcard address, so as to avoid
    * inadvertant collisions with listeners.  Do this in the same way.
    */
   wildcard_address(sa->sa_family, &waddr.sa);
   port_to_sockaddr(&waddr.sa, port);
-  snprintf(wsun.sun_path, sizeof(wsun.sun_path), "%s/%s", sockdir,
-	   present_sockaddr(&waddr.sa, 0, buf, sizeof(buf)));
-  if ((rc = unix_socket_status(&wsun, !desperatep)) == USED) return (-1);
-  else if (rc == STALE) unlink(wsun.sun_path);
+  if (encode_single_inet_addr(&waddr.sa, &wsun, !desperatep) == USED)
+    return (-1);
 
   /* All is well. */
   return (0);
@@ -732,7 +743,6 @@ static int encode_inet_addr(struct sockaddr_un *sun,
   address addr;
   int port = port_from_sockaddr(sa);
   char buf[ADDRBUFSZ];
-  int rc;
 
   D( fprintf(stderr, "noip(%d): encode %s (%s)", getpid(),
 	     present_sockaddr(sa, 0, buf, sizeof(buf)),
@@ -746,20 +756,15 @@ static int encode_inet_addr(struct sockaddr_un *sun,
     /* Try the address as given.  If it's in use, or we don't necessarily
      * want an existing socket, then we're done.
      */
-    snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir,
-	     present_sockaddr(sa, 0, buf, sizeof(buf)));
-    rc = unix_socket_status(sun, 0);
-    if (rc == STALE) unlink(sun->sun_path);
-    if (rc == USED || (f&ENCF_FRESH)) goto found;
+    if (encode_single_inet_addr(sa, sun, 0) == USED || (f&ENCF_FRESH))
+      goto found;
 
     /* We're looking for a socket which already exists.  Try the
      * corresponding wildcard address.
      */
     wildcard_address(sa->sa_family, &addr.sa);
     port_to_sockaddr(&addr.sa, port);
-    snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir,
-	     present_sockaddr(&addr.sa, 0, buf, sizeof(buf)));
-    if (unix_socket_status(sun, 0) == STALE) unlink(sun->sun_path);
+    encode_single_inet_addr(&addr.sa, sun, 0);
 
   } else {
     /* We want a fresh new socket. */