Implement `portfwd-loopback-choice'. Works on local side in Unix as

[u/mdw/putty] / unix / uxnet.c

diff --git a/unix/uxnet.c b/unix/uxnet.c
index e4e07b0..7a9630a 100644 (file)
--- a/unix/uxnet.c
+++ b/unix/uxnet.c
@@ -21,6 +21,8 @@
 #include "network.h"
 #include "tree234.h"
 
+#define ipv4_is_loopback(addr) (inet_netof(addr) == IN_LOOPBACKNET)
+
 struct Socket_tag {
     struct socket_function_table *fn;
     /* the above variable absolutely *must* be the first in this structure */
@@ -474,7 +476,7 @@ Socket sk_new(SockAddr addr, int port, int privport, int oobinline,
     return (Socket) ret;
 }
 
-Socket sk_newlistener(int port, Plug plug, int local_host_only)
+Socket sk_newlistener(char *srcaddr, int port, Plug plug, int local_host_only)
 {
     static struct socket_function_table fn_table = {
        sk_tcp_plug,
@@ -534,6 +536,8 @@ Socket sk_newlistener(int port, Plug plug, int local_host_only)
     if (addr->family == AF_INET6) {
        memset(&a6, 0, sizeof(a6));
        a6.sin6_family = AF_INET6;
+       /* FIXME: srcaddr is ignored for IPv6, because I (SGT) don't
+        * know how to do it. :-) */
        if (local_host_only)
            a6.sin6_addr = in6addr_loopback;
        else
@@ -542,11 +546,32 @@ Socket sk_newlistener(int port, Plug plug, int local_host_only)
     } else
 #endif
     {
+       int got_addr = 0;
        a.sin_family = AF_INET;
-       if (local_host_only)
-           a.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
-       else
-           a.sin_addr.s_addr = htonl(INADDR_ANY);
+
+       /*
+        * Bind to source address. First try an explicitly
+        * specified one...
+        */
+       if (srcaddr) {
+           a.sin_addr.s_addr = inet_addr(srcaddr);
+           if (a.sin_addr.s_addr != INADDR_NONE) {
+               /* Override localhost_only with specified listen addr. */
+               ret->localhost_only = ipv4_is_loopback(a.sin_addr);
+               got_addr = 1;
+           }
+       }
+
+       /*
+        * ... and failing that, go with one of the standard ones.
+        */
+       if (!got_addr) {
+           if (local_host_only)
+               a.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+           else
+               a.sin_addr.s_addr = htonl(INADDR_ANY);
+       }
+
        a.sin_port = htons((short)port);
     }
 #ifdef IPV6
@@ -763,8 +788,7 @@ int select_result(int fd, int event)
                break;
            }
 
-           if (s->localhost_only &&
-               ntohl(isa.sin_addr.s_addr) != INADDR_LOOPBACK) {
+           if (s->localhost_only && !ipv4_is_loopback(isa.sin_addr)) {
                close(t);              /* someone let nonlocal through?! */
            } else if (plug_accepting(s->plug, (void*)t)) {
                close(t);              /* denied or error */