Add --[enable|disable]-v4-mapped configure option to control

whether or not Apache expects to handle IPv4 connections
on IPv6 listening sockets.  Either setting will work on
systems with the IPV6_V6ONLY socket option.  --enable-v4-mapped
must be used on systems that always allow IPv4 connections on
IPv6 listening sockets.

Note: As the ssl config file is not automatically generated and
      it is expected to require editing anyway to work, the only
      change there was to suggest the required Listen statements
      in a comment.

PR:   PR 14037 (Bugzilla), PR 7492 (Gnats), various dups of these PRs


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@97516 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 19 insertions, 0 deletions

diff --git a/server/listen.c b/server/listen.c
index e57bef075e..cbdefae9bd 100644
--- a/server/listen.c
+++ b/server/listen.c
@@ -88,6 +88,13 @@ static apr_status_t make_sock(apr_pool_t *p, ap_listen_rec *server)
 {
     apr_socket_t *s = server->sd;
     int one = 1;
+#if APR_HAVE_IPV6
+#ifdef AP_ENABLE_V4_MAPPED
+    int v6only_setting = 0;
+#else
+    int v6only_setting = 1;
+#endif
+#endif
     apr_status_t stat;
 
 #ifndef WIN32
@@ -110,6 +117,18 @@ static apr_status_t make_sock(apr_pool_t *p, ap_listen_rec *server)
         return stat;
     }
 
+#if APR_HAVE_IPV6
+    stat = apr_socket_opt_set(s, APR_IPV6_V6ONLY, v6only_setting);
+    if (stat != APR_SUCCESS && stat != APR_ENOTIMPL) {
+        ap_log_perror(APLOG_MARK, APLOG_CRIT, stat, p,
+                      "make_sock: for address %pI, apr_socket_opt_set: "
+                      "(IPV6_V6ONLY)",
+                      server->bind_addr);
+        apr_socket_close(s);
+        return stat;
+    }
+#endif
+
     /*
      * To send data over high bandwidth-delay connections at full
      * speed we must force the TCP window to open wide enough to keep the