From bcce45edf1a7576ca73d7841b1079dc1e35c8ff9 Mon Sep 17 00:00:00 2001
From: simon <simon@cda61777-01e9-0310-a592-d414129be87e>
Date: Mon, 27 Aug 2001 15:59:37 +0000
Subject: [PATCH] Port forwarding update: local-host-only listening sockets are
 now done properly (by binding to INADDR_LOOPBACK) instead of hackishly (by
 binding to INADDR_ANY, looking at the peer address when a connection is
 accepted, and slamming the connection shut at that point).

git-svn-id: svn://svn.tartarus.org/sgt/putty@1215 cda61777-01e9-0310-a592-d414129be87e
---
 network.h |  6 +++---
 portfwd.c | 11 +++--------
 winnet.c  | 46 ++++++++++++++++++++++++++--------------------
 3 files changed, 32 insertions(+), 31 deletions(-)

diff --git a/network.h b/network.h
index 0e1420ac..4b7808a3 100644
--- a/network.h
+++ b/network.h
@@ -54,7 +54,7 @@ struct plug_function_table {
      * on a socket is cleared or partially cleared. The new backlog
      * size is passed in the `bufsize' parameter.
      */
-    int (*accepting)(Plug p, struct sockaddr *addr, void *sock);
+    int (*accepting)(Plug p, void *sock);
     /*
      * returns 0 if the host at address addr is a valid host for connecting or error
      */
@@ -69,7 +69,7 @@ void sk_addr_free(SockAddr addr);
 Socket sk_new(SockAddr addr, int port, int privport, int oobinline,
 	      Plug p);
 
-Socket sk_newlistenner(int port, Plug plug);
+Socket sk_newlistener(int port, Plug plug, int local_host_only);
 
 Socket sk_register(void *sock, Plug plug);
 
@@ -83,7 +83,7 @@ Socket sk_register(void *sock, Plug plug);
 #define plug_closing(p,msg,code,callback) (((*p)->closing) (p, msg, code, callback))
 #define plug_receive(p,urgent,buf,len) (((*p)->receive) (p, urgent, buf, len))
 #define plug_sent(p,bufsize) (((*p)->sent) (p, bufsize))
-#define plug_accepting(p, addr, sock) (((*p)->accepting)(p, addr, sock))
+#define plug_accepting(p, sock) (((*p)->accepting)(p, sock))
 #endif
 
 /*
diff --git a/portfwd.c b/portfwd.c
index 43353988..00fc098f 100644
--- a/portfwd.c
+++ b/portfwd.c
@@ -153,9 +153,8 @@ char *pfd_newconnect(Socket *s, char *hostname, int port, void *c)
  called when someone connects to the local port
  */
 
-static int pfd_accepting(Plug p, struct sockaddr *addr, void *sock)
+static int pfd_accepting(Plug p, void *sock)
 {
-    /* for now always accept this socket */
     static struct plug_function_table fn_table = {
 	pfd_closing,
 	pfd_receive,
@@ -163,13 +162,9 @@ static int pfd_accepting(Plug p, struct sockaddr *addr, void *sock)
 	NULL
     };
     struct PFwdPrivate *pr, *org;
-    struct sockaddr_in *sin = (struct sockaddr_in *)addr;
     Socket s;
     char *err;
 
-    if (ntohl(sin->sin_addr.s_addr) != 0x7F000001 && !cfg.lport_acceptall)
-	return 1; /* denied */
-
     org = (struct PFwdPrivate *)p;
     pr = (struct PFwdPrivate *) smalloc(sizeof(struct PFwdPrivate));
     pr->fn = &fn_table;
@@ -205,7 +200,7 @@ static int pfd_accepting(Plug p, struct sockaddr *addr, void *sock)
 
 
 /* Add a new forwarding from port -> desthost:destport
- sets up a listenner on the local machine on port
+ sets up a listener on the local machine on port
  */
 char *pfd_addforward(char *desthost, int destport, int port)
 {
@@ -232,7 +227,7 @@ char *pfd_addforward(char *desthost, int destport, int port)
     pr->ready = 0;
     pr->waiting = NULL;
 
-    pr->s = s = sk_newlistenner(port, (Plug) pr);
+    pr->s = s = sk_newlistener(port, (Plug) pr, !cfg.lport_acceptall);
     if ((err = sk_socket_error(s))) {
 	sfree(pr);
 	return err;
diff --git a/winnet.c b/winnet.c
index ee2fc3a6..40f416d8 100644
--- a/winnet.c
+++ b/winnet.c
@@ -570,7 +570,7 @@ Socket sk_new(SockAddr addr, int port, int privport, int oobinline,
     return (Socket) ret;
 }
 
-Socket sk_newlistenner(int port, Plug plug)
+Socket sk_newlistener(int port, Plug plug, int local_host_only)
 {
     static struct socket_function_table fn_table = {
 	sk_tcp_plug,
@@ -627,13 +627,19 @@ Socket sk_newlistenner(int port, Plug plug)
 	if (addr->family == AF_INET6) {
 	    memset(&a6, 0, sizeof(a6));
 	    a6.sin6_family = AF_INET6;
-/*a6.sin6_addr      = in6addr_any; *//* == 0 */
+	    if (local_host_only)
+		a6.sin6_addr = in6addr_loopback;
+	    else
+		a6.sin6_addr = in6addr_any;
 	    a6.sin6_port = htons(port);
 	} else
 #endif
 	{
 	    a.sin_family = AF_INET;
-	    a.sin_addr.s_addr = htonl(INADDR_ANY);
+	    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
@@ -909,23 +915,23 @@ int select_result(WPARAM wParam, LPARAM lParam)
 	return open;
        case FD_ACCEPT:
 	{
-		struct sockaddr isa;
-		int addrlen = sizeof(struct sockaddr);
-		SOCKET t;  /* socket of connection */
-
-		memset(&isa, 0, sizeof(struct sockaddr));
-		err = 0;
-		t = accept(s->s,&isa,&addrlen);
-		if (t == INVALID_SOCKET)
-				{
-					err = WSAGetLastError();
-					if (err == WSATRY_AGAIN)
-						break;
-				}
-
-		if (plug_accepting(s->plug, &isa, (void*)t)) {
-			closesocket(t); // denied or error
-		}
+	    struct sockaddr isa;
+	    int addrlen = sizeof(struct sockaddr);
+	    SOCKET t;  /* socket of connection */
+
+	    memset(&isa, 0, sizeof(struct sockaddr));
+	    err = 0;
+	    t = accept(s->s,&isa,&addrlen);
+	    if (t == INVALID_SOCKET)
+	    {
+		err = WSAGetLastError();
+		if (err == WSATRY_AGAIN)
+		    break;
+	    }
+
+	    if (plug_accepting(s->plug, (void*)t)) {
+		closesocket(t);	       /* denied or error */
+	    }
 	}
     }
 
-- 
2.11.0