[NETFILTER]: nf_conntrack_sip: support method specific request/response handling

Add support for per-method request/response handlers and perform SDP
parsing for INVITE/UPDATE requests and for all informational and
successful responses.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 20 insertions, 0 deletions

diff --git a/include/linux/netfilter/nf_conntrack_sip.h b/include/linux/netfilter/nf_conntrack_sip.h
index 68a0d6a41733..da93e80804c2 100644
--- a/include/linux/netfilter/nf_conntrack_sip.h
+++ b/include/linux/netfilter/nf_conntrack_sip.h
@@ -5,6 +5,25 @@
 #define SIP_PORT        5060
 #define SIP_TIMEOUT     3600
 
+struct sip_handler {
+        const char      *method;
+        unsigned int    len;
+        int             (*request)(struct sk_buff *skb,
+                                   const char **dptr, unsigned int *datalen,
+                                   unsigned int cseq);
+        int             (*response)(struct sk_buff *skb,
+                                    const char **dptr, unsigned int *datalen,
+                                    unsigned int cseq, unsigned int code);
+};
+
+#define SIP_HANDLER(__method, __request, __response)                    \
+{                                                                       \
+        .method         = (__method),                                   \
+        .len            = sizeof(__method) - 1,                         \
+        .request        = (__request),                                  \
+        .response       = (__response),                                 \
+}
+
 struct sip_header {
         const char      *name;
         const char      *cname;
@@ -35,6 +54,7 @@ struct sip_header {
         __SIP_HDR(__name, NULL, __search, __match)
 
 enum sip_header_types {
+        SIP_HDR_CSEQ,
         SIP_HDR_FROM,
         SIP_HDR_TO,
         SIP_HDR_CONTACT,