getaddrinfo: Refactor code for readability

The close_retry goto jump is confusing and clumsy to read, so refactor
the code a bit to make it easier to follow.

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: DJ Delorie <dj@redhat.com>

diff --git a/sysdeps/posix/getaddrinfo.c b/sysdeps/posix/getaddrinfo.c
index aa34de6591b5b5491fe6707d8c68c8f13d1245b4..bcff909b2f3939d04b6ad33a78ae4f510504f96c 100644 (file)
--- a/sysdeps/posix/getaddrinfo.c
+++ b/sysdeps/posix/getaddrinfo.c
@@ -2246,6 +2246,36 @@ gaiconf_reload (void)
     gaiconf_init ();
 }
 
+static bool
+try_connect (int *fdp, int *afp, struct sockaddr_in6 *source_addrp,
+            const struct sockaddr *addr, socklen_t addrlen, int family)
+{
+  int fd = *fdp;
+  int af = *afp;
+  socklen_t sl = sizeof (*source_addrp);
+
+  while (true)
+    {
+      if (fd != -1 && __connect (fd, addr, addrlen) == 0
+         && __getsockname (fd, (struct sockaddr *) source_addrp, &sl) == 0)
+       return true;
+
+      if (errno == EAFNOSUPPORT && af == AF_INET6 && family == AF_INET)
+       {
+         /* This could mean IPv6 sockets are IPv6-only.  */
+         if (fd != -1)
+           __close_nocancel_nostatus (fd);
+         *afp = af = AF_INET;
+         *fdp = fd = __socket (AF_INET, SOCK_DGRAM | SOCK_CLOEXEC,
+                               IPPROTO_IP);
+         continue;
+       }
+
+      return false;
+    }
+
+  __builtin_unreachable ();
+}
 
 int
 getaddrinfo (const char *name, const char *service,
@@ -2436,7 +2466,6 @@ getaddrinfo (const char *name, const char *service,
              if (fd == -1 || (af == AF_INET && q->ai_family == AF_INET6))
                {
                  if (fd != -1)
-                 close_retry:
                    __close_nocancel_nostatus (fd);
                  af = q->ai_family;
                  fd = __socket (af, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_IP);
@@ -2448,14 +2477,10 @@ getaddrinfo (const char *name, const char *service,
                  __connect (fd, &sa, sizeof (sa));
                }
 
-             socklen_t sl = sizeof (results[i].source_addr);
-             if (fd != -1
-                 && __connect (fd, q->ai_addr, q->ai_addrlen) == 0
-                 && __getsockname (fd,
-                                   (struct sockaddr *) &results[i].source_addr,
-                                   &sl) == 0)
+             if (try_connect (&fd, &af, &results[i].source_addr, q->ai_addr,
+                              q->ai_addrlen, q->ai_family))
                {
-                 results[i].source_addr_len = sl;
+                 results[i].source_addr_len = sizeof (results[i].source_addr);
                  results[i].got_source_addr = true;
 
                  if (in6ai != NULL)
@@ -2520,10 +2545,6 @@ getaddrinfo (const char *name, const char *service,
                      results[i].source_addr_len = sizeof (struct sockaddr_in);
                    }
                }
-             else if (errno == EAFNOSUPPORT && af == AF_INET6
-                      && q->ai_family == AF_INET)
-               /* This could mean IPv6 sockets are IPv6-only.  */
-               goto close_retry;
              else
                /* Just make sure that if we have to process the same
                   address again we do not copy any memory.  */