From f0608ceaa79d99d24e97517f9a9a0fed2b9698b4 Mon Sep 17 00:00:00 2001 From: Marco Angaroni Date: Tue, 30 Aug 2016 18:48:24 +0200 Subject: [PATCH] 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 Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_sip.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c index 251a9a44d189..d8035351aff5 100644 --- a/net/netfilter/nf_conntrack_sip.c +++ b/net/netfilter/nf_conntrack_sip.c @@ -83,9 +83,10 @@ static int digits_len(const struct nf_conn *ct, const char *dptr, static int iswordc(const char c) { if (isalnum(c) || c == '!' || c == '"' || c == '%' || - (c >= '(' && c <= '/') || c == ':' || c == '<' || c == '>' || + (c >= '(' && c <= '+') || c == ':' || c == '<' || c == '>' || c == '?' || (c >= '[' && c <= ']') || c == '_' || c == '`' || - c == '{' || c == '}' || c == '~') + c == '{' || c == '}' || c == '~' || (c >= '-' && c <= '/') || + c == '\'') return 1; return 0; } -- 2.30.2