netfilter: nf_ct_sip: correct allowed characters in Call-ID SIP header
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 /
"/" / "[" / "]" / "?" /
"{" / "}" )
Signed-off-by: Marco Angaroni <marcoangaroni@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
1 file changed