[tor-commits] [flashproxy/master] Also figure out the register_addr after opening listeners.

[dcf at torproject.org]

commit 5a6529e1e2792fe794cee239f963bf5a65503e16
Author: David Fifield <david at bamsoftware.com>
Date:   Sat Feb 1 21:01:04 2014 -0800

    Also figure out the register_addr after opening listeners.
    
    So that you register the proper port number when you give ":0" on the
    command line.
    
    There may be up to two listeners: one for IPv4 and one for IPv6, and
    they may be on different ports or they may be the same. Previously they
    could only be the same, so we could pass a specification like ":9000" to
    a registration helper, and whether it happened to use IPv4 or IPv6
    things would work out. Now that the ports may be different with ":0",
    there is ambiguity because omitting the host part has meant
    "registration helper guesses the external address" which really means
    "the remote server the registration helper talks to guesses the
    address." If we have, for example,
    	$ ./flashproxy-client --external --register :9001 :0
    	2014-02-01 21:35:29 Listening remote on 0.0.0.0:10000.
    	2014-02-01 21:35:29 Listening remote on [::]:20000.
    it would be a mistake to try and register both ":10000" and ":20000",
    because they will both be guessed to be the same address family. We
    don't have a way to hint to registration helpers that a guessed address
    should belong to a certain address family.
    
    A similar but smaller difficulty exists with --register-addr. That
    option takes default values from the actual listening address, so that
    you can, for example, provide an IP address and have the port filled in
    automatically. Providing an IPv4 address would cause the IPv4 address to
    be registered twice, once correctly with a port belonging to IPv4 and
    once incorrectly with a port belonging to IPv6.
    
    Unsure fo the best way to handle this, I kept that there is a single
    register_addr, and it is set only to the IPv4 listener. The behavior is
    the same in all cases that worked before; that is, all cases that don't
    use ":0" as a port specification. If you need to override it, you can
    use --register-addr.
---
 flashproxy-client |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/flashproxy-client b/flashproxy-client
index f3c8926..09630b3 100755
--- a/flashproxy-client
+++ b/flashproxy-client
@@ -1179,7 +1179,6 @@ def main():
         options.remote_addrs.append(("0.0.0.0", remote_addr[1]))
         if socket.has_ipv6:
             options.remote_addrs.append(("::", remote_addr[1]))
-    options.register_addr = parse_addr_spec(register_addr_spec or ":", *remote_addr)
 
     if not register_methods:
         register_methods = DEFAULT_REGISTER_METHODS
@@ -1196,6 +1195,13 @@ def main():
             continue
         remote_listen.append(listen)
         log(u"Listening remote on %s." % format_sockaddr(listen.getsockname()))
+        if options.register_addr is None:
+            host, port = socket.getnameinfo(listen.getsockname(), socket.NI_NUMERICHOST | socket.NI_NUMERICSERV)
+            port = int(port)
+            if not remote_addr[0]:
+                # Make host part blank (not 0.0.0.0) if unspecified.
+                host = ""
+            options.register_addr = parse_addr_spec(register_addr_spec or ":", host, port)
     if not remote_listen:
         log(u"Failed to open any remote listeners, quitting.")
         pt_cmethoderror("Failed to open any remote listeners.")