mod_s2s: streamopened(): Tighter validation around stream 'to' and 'from' attributes...

diff --git a/plugins/s2s/mod_s2s.lua b/plugins/s2s/mod_s2s.lua
index 407a7e04125bba573da14808af7022d950d66165..fcdd9dd62dafd03e57dca54cf5093bc375efead7 100644 (file)
--- a/plugins/s2s/mod_s2s.lua
+++ b/plugins/s2s/mod_s2s.lua
@@ -168,9 +168,33 @@ function stream_callbacks.streamopened(session, attr)
 
        if session.direction == "incoming" then
                -- Send a reply stream header
-               session.to_host = attr.to and nameprep(attr.to);
-               session.from_host = attr.from and nameprep(attr.from);
-       
+               
+               -- Validate to/from
+               local to, from = nameprep(attr.to), nameprep(attr.from);
+               if not to and attr.to then -- COMPAT: Some servers do not reliably set 'to' (especially on stream restarts)
+                       session:close({ condition = "improper-addressing", text = "Invalid 'to' address" });
+                       return;
+               end
+               if not from and attr.from then -- COMPAT: Some servers do not reliably set 'from' (especially on stream restarts)
+                       session:close({ condition = "improper-addressing", text = "Invalid 'from' address" });
+                       return;
+               end
+               
+               -- Set session.[from/to]_host if they have not been set already and if
+               -- this session isn't already authenticated
+               if session.type == "s2sin_unauthed" and from and not session.from_host then
+                       session.from_host = from;
+               elseif from ~= session.from_host then
+                       session:close({ condition = "improper-addressing", text = "New stream 'from' attribute does not match original" });
+                       return;
+               end
+               if session.type == "s2sin_unauthed" and to and not session.to_host then
+                       session.to_host = to;
+               elseif to ~= session.to_host then
+                       session:close({ condition = "improper-addressing", text = "New stream 'to' attribute does not match original" });
+                       return;
+               end
+               
                session.streamid = uuid_gen();
                (session.log or log)("debug", "Incoming s2s received <stream:stream>");
                if session.to_host then