Re: [PATCH 2/2] netfilter: correct allowed characters in Call-ID SIP header

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Tue, Aug 30, 2016 at 06:48:24PM +0200, Marco Angaroni wrote:
> Current parsing methods for SIP header Call-ID do not check correctly all
> characters allowed by RFC 3261. In particular "," character is allowed 
> instead of "'" character. As a result Call-ID headers like the following
> are discarded by IPVS SIP persistence engine.
> 
> Call-ID: -.!%*_+`'~()<>:\"/[]?{}
> 
> Above example is composed using all non-alphanumeric characters listed
> in RFC 3261 for Call-ID header syntax.
> 
> Proposed fix is in nf_conntrack_sip module; function iswordc() checks this
> range: (c >= '(' && c <= '/') which includes these characters: ()*+,-./
> They are all allowed except ",". Instead "'" is not included in the list.
> 
> Below is an extract of relevant SIP ABNF syntax.
> 
> Call-ID  =  ( "Call-ID" / "i" ) HCOLON callid
> callid   =  word [ "@" word ]
> 
> HCOLON  =  *( SP / HTAB ) ":" SWS
> SWS     =  [LWS] ; sep whitespace
> LWS     =  [*WSP CRLF] 1*WSP ; linear whitespace
> WSP     =  SP / HTAB
> word    =  1*(alphanum / "-" / "." / "!" / "%" / "*" /
>            "_" / "+" / "`" / "'" / "~" /
>            "(" / ")" / "<" / ">" /
>            ":" / "\" / DQUOTE /
>            "/" / "[" / "]" / "?" /
>            "{" / "}" )

Also applied, thanks.