When the platform supports IPv6 (according to APR) and

the system is configured to support IPv6, Apache gets IPv6
listening sockets unless the Listen statement says otherwise
(i.e., Listen specifies an IPv4 numeric address string or a
hostname which resolves to an IPv4 address).

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@87388 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/server/listen.c b/server/listen.c
index a753ad1a3d74c9d7fb9b68fac6da79d01acdc954..202f5b8d7b81d41554887d6b8b8a8df3f72cc433 100644 (file)
--- a/server/listen.c
+++ b/server/listen.c
@@ -72,6 +72,11 @@
 #endif
 
 ap_listen_rec *ap_listeners;
+#if APR_HAVE_IPV6
+static int default_family = APR_UNSPEC;
+#else
+static int default_family = APR_INET;
+#endif
 static ap_listen_rec *old_listeners;
 static int ap_listenbacklog;
 static int send_buffer_size;
@@ -169,6 +174,29 @@ static apr_status_t close_listeners_on_exec(void *v)
 }
 
 
+static void find_default_family(apr_pool_t *p)
+{
+#if APR_HAVE_IPV6
+    /* We know the platform supports IPv6, but this particular
+     * system may not have IPv6 enabled.  See if we can get an
+     * AF_INET6 socket.
+     */
+    if (default_family == APR_UNSPEC) {
+        apr_socket_t *tmp_sock;
+
+        if (apr_create_socket(&tmp_sock, APR_INET6, SOCK_STREAM, 
+                              p) == APR_SUCCESS) {
+            apr_close_socket(tmp_sock);
+            default_family = APR_INET6;
+        }
+        else {
+            default_family = APR_INET;
+        }
+    }
+#endif
+}
+
+
 static void alloc_listener(process_rec *process, char *addr, apr_port_t port)
 {
     ap_listen_rec **walk;
@@ -178,26 +206,20 @@ static void alloc_listener(process_rec *process, char *addr, apr_port_t port)
     apr_port_t oldport;
     apr_sockaddr_t *sa;
 
-    if (!addr) {
-        /* XXX not valid for IPv6 if we can get an IPv6 socket when the
-         *     config doesn't specify an interface address
-         *
-         *     We need to look at the configuration to see which mode we're
-         *     in: 
-         *     a) get IPv6 if we can but fall back to IPv4
-         *        => leave addr NULL so the logic below calls apr_create_socket()
-         *           first
-         *     b) get IPv4
-         *        => set addr to 0.0.0.0
-         *     c) get IPv6
-         *        => set addr to ::
-         *
-         *     Alternative: earlier in initialization, if we start up in fall-
-         *     back-to-IPv4 mode, go ahead and see if we can get an IPv6 socket;
-         *     if not, set mode to get-IPv4; then, we have fewer cases to handle
-         *     here (and probably elsewhere)
-         */
-        addr = APR_ANYADDR;
+    if (!addr) { /* don't bind to specific interface */
+        find_default_family(process->pool);
+        switch(default_family) {
+        case APR_INET:
+            addr = "0.0.0.0";
+            break;
+#if APR_HAVE_IPV6
+        case APR_INET6:
+            addr = "::";
+            break;
+#endif
+        default:
+            ap_assert(1 != 1); /* should not occur */
+        }
     }
 
     /* see if we've got an old listener for this address:port */
@@ -218,32 +240,17 @@ static void alloc_listener(process_rec *process, char *addr, apr_port_t port)
     /* this has to survive restarts */
     new = apr_palloc(process->pool, sizeof(ap_listen_rec));
     new->active = 0;
-    if (addr) {
-        /* binding to specific interface; let apr_getaddrinfo() figure out
-         * what address family is appropriate;
-         */
-        if ((status = apr_getaddrinfo(&new->bind_addr, addr, APR_UNSPEC, port, 0, 
-                                      process->pool)) != APR_SUCCESS) {
-            ap_log_error(APLOG_MARK, APLOG_CRIT, status, NULL,
-                        "alloc_listener: failed to set up sockaddr for %s", addr);
-            return;
-        }
-        if ((status = apr_create_socket(&new->sd, new->bind_addr->sa.sin.sin_family, 
-                                        SOCK_STREAM, process->pool)) != APR_SUCCESS) {
-            ap_log_error(APLOG_MARK, APLOG_CRIT, status, NULL,
-                         "alloc_listener: failed to get a socket for %s", addr);
-            return;
-        }
+    if ((status = apr_getaddrinfo(&new->bind_addr, addr, APR_UNSPEC, port, 0, 
+                                  process->pool)) != APR_SUCCESS) {
+        ap_log_error(APLOG_MARK, APLOG_CRIT, status, NULL,
+                     "alloc_listener: failed to set up sockaddr for %s", addr);
+        return;
     }
-    else { /* XXX See big XXX above in this function. */
-        if ((status = apr_create_socket(&new->sd, APR_INET,
-                                        SOCK_STREAM, process->pool)) != APR_SUCCESS) {
-            ap_log_error(APLOG_MARK, APLOG_CRIT, status, NULL,
-                         "alloc_listener: failed to get a socket for INADDR_ANY");
-            return;
-        }
-        apr_get_sockaddr(&new->bind_addr, APR_LOCAL, new->sd);
-        apr_set_port(new->bind_addr, port);
+    if ((status = apr_create_socket(&new->sd, new->bind_addr->sa.sin.sin_family, 
+                                    SOCK_STREAM, process->pool)) != APR_SUCCESS) {
+        ap_log_error(APLOG_MARK, APLOG_CRIT, status, NULL,
+                     "alloc_listener: failed to get a socket for %s", addr);
+        return;
     }
     new->next = ap_listeners;
     ap_listeners = new;