fix from pr 6207. a bit more of an explanation: we write the correct

number of bits when connecting via a SOCKS 5 proxy over ipv6, but we
also need to read the same number depending on the received address
type.  this issue is not noticeable with ssh's SOCKS 5 support since it
always set the address type as ipv4.  this fixes connections via SOCKS 5
proxies which set their address type as ipv6 when using ipv6.

after review with, and ok, nicm@

1 files changed, 18 insertions, 4 deletions

diff --git a/src/usr.bin/nc/socks.c b/src/usr.bin/nc/socks.c
index b38dff741e..71108d543b 100644
--- a/src/usr.bin/nc/socks.c
+++ b/src/usr.bin/nc/socks.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: socks.c,v 1.18 2010/04/20 07:26:35 nicm Exp $ */
+/*      $OpenBSD: socks.c,v 1.19 2011/02/12 15:54:18 okan Exp $ */
 
 /*
  * Copyright (c) 1999 Niklas Hallqvist.  All rights reserved.
@@ -222,11 +222,25 @@ socks_connect(const char *host, const char *port,
                 if (cnt != wlen)
                         err(1, "write failed (%zu/%zu)", cnt, wlen);
 
-                cnt = atomicio(read, proxyfd, buf, 10);
-                if (cnt != 10)
-                        err(1, "read failed (%zu/10)", cnt);
+                cnt = atomicio(read, proxyfd, buf, 4);
+                if (cnt != 4)
+                        err(1, "read failed (%zu/4)", cnt);
                 if (buf[1] != 0)
                         errx(1, "connection failed, SOCKS error %d", buf[1]);
+                switch (buf[3]) {
+                case SOCKS_IPV4:
+                        cnt = atomicio(read, proxyfd, buf + 4, 6);
+                        if (cnt != 6)
+                                err(1, "read failed (%d/6)", cnt);
+                        break;
+                case SOCKS_IPV6:
+                        cnt = atomicio(read, proxyfd, buf + 4, 18);
+                        if (cnt != 18)
+                                err(1, "read failed (%d/18)", cnt);
+                        break;
+                default:
+                        errx(1, "connection failed, unsupported address type");
+                }
         } else if (socksv == 4) {
                 /* This will exit on lookup failure */
                 decode_addrport(host, port, (struct sockaddr *)&addr,