commit a04414d0518930fbfcdb21cfb6486e1efc9ed8b4 Author: David Fifield david@bamsoftware.com Date: Wed Jul 4 06:42:32 2012 -0700

Use an exception in parse_socks_header instead of an error return. --- connector.py | 23 +++++++++++------------ 1 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/connector.py b/connector.py index ed4f02c..353d6b5 100755 --- a/connector.py +++ b/connector.py @@ -554,26 +554,23 @@ def grab_string(s, pos): return pos, None

def parse_socks_request(data): + """Parse the 8-byte SOCKS header at the beginning of data. Returns a + (dest, port) tuple. Raises ValueError on error.""" try: ver, cmd, dport, o1, o2, o3, o4 = struct.unpack(">BBHBBBB", data[:8]) except struct.error: - log(u"Couldn't unpack SOCKS4 header.") - return None + raise ValueError("Couldn't unpack SOCKS4 header") if ver != 4: - log(u"SOCKS header has wrong version (%d)." % ver) - return None + raise ValueError("SOCKS header has wrong version (%d)" % ver) if cmd != 1: - log(u"SOCKS header had wrong command (%d)." % cmd) - return None + raise ValueError("SOCKS header had wrong command (%d)" % cmd) pos, userid = grab_string(data, 8) if userid is None: - log(u"Couldn't read userid from SOCKS header.") - return None + raise ValueError("Couldn't read userid from SOCKS header") if o1 == 0 and o2 == 0 and o3 == 0 and o4 != 0: pos, dest = grab_string(data, pos) if dest is None: - log(u"Couldn't read destination from SOCKS4a header.") - return None + raise ValueError("Couldn't read destination from SOCKS4a header") else: dest = "%d.%d.%d.%d" % (o1, o2, o3, o4) return dest, dport @@ -585,8 +582,10 @@ def handle_socks_request(fd): except socket.error, e: log(u"Socket error from SOCKS-pending: %s" % repr(str(e))) return False - dest_addr = parse_socks_request(data) - if dest_addr is None: + try: + dest_addr = parse_socks_request(data) + except ValueError, e: + log(u"Error parsing SOCKS header: %s." % str(e)) # Error reply. fd.sendall(struct.pack(">BBHBBBB", 0, 91, 0, 0, 0, 0, 0)) return False