Hi Ulrich, Cc'ing Marco Angaroni. On Wed, Oct 19, 2016 at 10:24:02AM +0200, Ulrich Weber wrote: > on SIP requests, so a fragmented TCP SIP packet starting with > INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE,SUBSCRIBE > Content-Length: 0 > > will not bet interpreted as an INVITE request. > > Confirm with RFC 3261 > Request-Line = Method SP Request-URI SP SIP-Version CRLF Marco has missed your email, so I'm copying and pasting what he told me wrt. to your patch: My understanding is that Ulrich is referring to something like an "Allow" header of a SIP message where the header name is part of a TCP segment and the header value is part of the following TCP segment: Allow: INVITE,ACK,CANCEL,OPTIONS,BYE So I think the fix (check for a space after the method name) is correct. However maybe the check could be made more robust, because if you have the fragmented "Allow" header containing the method names with a space before comma (it's permitted by SIP grammar) like you see below, you would again think that it's the first line of the SIP message: Allow: INVITE , ACK , CANCEL , OPTIONS , BYE Maybe it's worth checking two bytes after method name; the first byte must be a space and the second must a alphanumeric character: the URI following the method name has to start with "sip:" or "sips:" or some other scheme, which starts for sure with an ALPHA character. Request-Line = Method SP Request-URI SP SIP-Version CRLF Request-URI = SIP-URI / SIPS-URI / absoluteURI absoluteURI = scheme ":" ( hier-part / opaque-part ) scheme = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." ) -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
