When checking if a connection comes from localhost, don't assume it's an IPv4

connection.  Instead, correctly check IPv4 and IPv6 connections, assume that
AF_LOCAL is always local, and anything else is always remote.

This makes trivial local-to-remote forwarding work on my system.

git-svn-id: svn://svn.tartarus.org/sgt/putty@5180 cda61777-01e9-0310-a592-d414129be87e

diff --git a/unix/uxnet.c b/unix/uxnet.c
index 357fc86..9cd01f6 100644 (file)
--- a/unix/uxnet.c
+++ b/unix/uxnet.c
@@ -948,6 +948,29 @@ static int sk_tcp_write_oob(Socket sock, const char *buf, int len)
     return s->sending_oob;
 }
 
+static int sockaddr_is_loopback(struct sockaddr *sa)
+{
+    struct sockaddr_in *sin;
+#ifndef NO_IPV6
+    struct sockaddr_in6 *sin6;
+#endif
+
+    switch (sa->sa_family) {
+      case AF_INET:
+       sin = (struct sockaddr_in *)sa;
+       return ipv4_is_loopback(sin->sin_addr);
+#ifndef NO_IPV6
+      case AF_INET6:
+       sin6 = (struct sockaddr_in6 *)sa;
+       return IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr);
+#endif
+      case AF_LOCAL:
+       return TRUE;
+      default:
+       return FALSE;
+    }
+}
+
 static int net_select_result(int fd, int event)
 {
     int ret;
@@ -1009,17 +1032,22 @@ static int net_select_result(int fd, int event)
             * On a listening socket, the readability event means a
             * connection is ready to be accepted.
             */
-           struct sockaddr_in isa;
-           int addrlen = sizeof(struct sockaddr_in);
+#ifdef NO_IPV6
+           struct sockaddr_in ss;
+#else
+           struct sockaddr_storage ss;
+#endif
+           socklen_t addrlen = sizeof(ss);
            int t;  /* socket of connection */
 
-           memset(&isa, 0, sizeof(struct sockaddr_in));
-           t = accept(s->s,(struct sockaddr *)&isa,(socklen_t *) &addrlen);
+           memset(&ss, 0, addrlen);
+           t = accept(s->s, (struct sockaddr *)&ss, &addrlen);
            if (t < 0) {
                break;
            }
 
-           if (s->localhost_only && !ipv4_is_loopback(isa.sin_addr)) {
+           if (s->localhost_only &&
+               !sockaddr_is_loopback((struct sockaddr *)&ss)) {
                close(t);              /* someone let nonlocal through?! */
            } else if (plug_accepting(s->plug, t)) {
                close(t);              /* denied or error */