[or-cvs] fix a crash: if you do socks4 with an IP of 0.0.0.x then we...

[Roger Dingledine]

Update of /home2/or/cvsroot/tor/src/or
In directory moria.mit.edu:/home2/arma/work/onion/cvs/tor/src/or

Modified Files:
	buffers.c 
Log Message:
fix a crash: if you do socks4 with an IP of 0.0.0.x then we get tricked
into thinking you're doing socks4a, and we look for the next byte.

thanks to aphex for finding this.


Index: buffers.c
===================================================================
RCS file: /home2/or/cvsroot/tor/src/or/buffers.c,v
retrieving revision 1.122
retrieving revision 1.123
diff -u -d -r1.122 -r1.123
--- buffers.c	7 Dec 2004 21:57:10 -0000	1.122
+++ buffers.c	22 Dec 2004 09:52:29 -0000	1.123
@@ -584,6 +584,10 @@
       tor_assert(next < buf->mem+buf->datalen);
 
       startaddr = NULL;
+      if (socks4_prot == socks4a && next+1 == buf->mem+buf->datalen) {
+        log_fn(LOG_DEBUG,"socks4: No part of destaddr here yet.");
+        return 0;
+      }
       if (socks4_prot != socks4a && !have_warned_about_unsafe_socks) {
         log_fn(LOG_WARN,"Your application (using socks4 on port %d) is giving Tor only an IP address. Applications that do DNS resolves themselves may leak information. Consider using Socks4A (e.g. via privoxy or socat) instead.", req->port);
 //      have_warned_about_unsafe_socks = 1; // (for now, warn every time)