resume being printist: if the hostname contains non-printable

characters, then fail. this time don't even bother telling the
server operator about these cases, because what's he going to do?

if it turns out that some significant population somewhere in the
world uses non-printable hostnames and wants to use tor, then i
hereby assume that they will contact us.


svn:r6171

src/or/buffers.c

@@ -1003,7 +1003,13 @@ fetch_from_buf_socks(buf_t *buf, socks_request_t *req, int log_sockstype)
           req->address[len] = 0;
           req->port = ntohs(get_uint16(buf->cur+5+len));
           buf_remove_from_front(buf, 5+len+2);
-
+          if (!tor_strisprint(req->address) || strchr(req->address,'\"')) {
+            log_warn(LD_PROTOCOL,
+                     "Your application (using socks5 on port %d) gave Tor "
+                     "a malformed hostname: %s. Rejecting the connection.",
+                     req->port, escaped(req->address));
+            return -1;
+          }
           if (log_sockstype)
             log_notice(LD_APP,
                   "Your application (using socks5 on port %d) gave "
@@ -1098,6 +1104,13 @@ fetch_from_buf_socks(buf_t *buf, socks_request_t *req, int log_sockstype)
       log_debug(LD_APP,"socks4: Everything is here. Success.");
       strlcpy(req->address, startaddr ? startaddr : tmpbuf,
               sizeof(req->address));
+      if (!tor_strisprint(req->address) || strchr(req->address,'\"')) {
+        log_warn(LD_PROTOCOL,
+                 "Your application (using socks4 on port %d) gave Tor "
+                 "a malformed hostname: %s. Rejecting the connection.",
+                 req->port, escaped(req->address));
+        return -1;
+      }
       /* next points to the final \0 on inbuf */
       buf_remove_from_front(buf, next-buf->cur+1);
       return 1;

src/or/connection_edge.c

@@ -1533,6 +1533,13 @@ connection_exit_begin_conn(cell_t *cell, circuit_t *circ)
     tor_free(address);
     return 0;
   }
+  if (!tor_strisprint(address)) {
+    log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+           "Non-printing characters in address %s in relay "
+           "begin cell. Dropping.", escaped(address));
+    tor_free(address);
+    return 0;
+  }
 
   log_debug(LD_EXIT,"Creating new exit connection.");
   n_stream = connection_new(CONN_TYPE_EXIT);