1 files changed, 114 insertions, 0 deletions
diff --git a/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h b/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h
new file mode 100644
index 00000000000000..8d090ef82f5ffc
--- /dev/null
+++ b/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h
@@ -0,0 +1,114 @@
+#ifndef _CONNTRACK_PROTO_GRE_H
+#define _CONNTRACK_PROTO_GRE_H
+#include <asm/byteorder.h>
+
+/* GRE PROTOCOL HEADER */
+
+/* GRE Version field */
+#define GRE_VERSION_1701	0x0
+#define GRE_VERSION_PPTP	0x1
+
+/* GRE Protocol field */
+#define GRE_PROTOCOL_PPTP	0x880B
+
+/* GRE Flags */
+#define GRE_FLAG_C		0x80
+#define GRE_FLAG_R		0x40
+#define GRE_FLAG_K		0x20
+#define GRE_FLAG_S		0x10
+#define GRE_FLAG_A		0x80
+
+#define GRE_IS_C(f)	((f)&GRE_FLAG_C)
+#define GRE_IS_R(f)	((f)&GRE_FLAG_R)
+#define GRE_IS_K(f)	((f)&GRE_FLAG_K)
+#define GRE_IS_S(f)	((f)&GRE_FLAG_S)
+#define GRE_IS_A(f)	((f)&GRE_FLAG_A)
+
+/* GRE is a mess: Four different standards */
+struct gre_hdr {
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+	__u16	rec:3,
+		srr:1,
+		seq:1,
+		key:1,
+		routing:1,
+		csum:1,
+		version:3,
+		reserved:4,
+		ack:1;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+	__u16	csum:1,
+		routing:1,
+		key:1,
+		seq:1,
+		srr:1,
+		rec:3,
+		ack:1,
+		reserved:4,
+		version:3;
+#else
+#error "Adjust your <asm/byteorder.h> defines"
+#endif
+	__u16	protocol;
+};
+
+/* modified GRE header for PPTP */
+struct gre_hdr_pptp {
+	__u8  flags;		/* bitfield */
+	__u8  version;		/* should be GRE_VERSION_PPTP */
+	__u16 protocol;		/* should be GRE_PROTOCOL_PPTP */
+	__u16 payload_len;	/* size of ppp payload, not inc. gre header */
+	__u16 call_id;		/* peer's call_id for this session */
+	__u32 seq;		/* sequence number.  Present if S==1 */
+	__u32 ack;		/* seq number of highest packet recieved by */
+				/*  sender in this session */
+};
+
+
+/* this is part of ip_conntrack */
+struct ip_ct_gre {
+	unsigned int stream_timeout;
+	unsigned int timeout;
+};
+
+#ifdef __KERNEL__
+struct ip_conntrack_expect;
+struct ip_conntrack;
+
+/* structure for original <-> reply keymap */
+struct ip_ct_gre_keymap {
+	struct list_head list;
+
+	struct ip_conntrack_tuple tuple;
+};
+
+/* add new tuple->key_reply pair to keymap */
+int ip_ct_gre_keymap_add(struct ip_conntrack *ct,
+			 struct ip_conntrack_tuple *t,
+			 int reply);
+
+/* delete keymap entries */
+void ip_ct_gre_keymap_destroy(struct ip_conntrack *ct);
+
+
+/* get pointer to gre key, if present */
+static inline u_int32_t *gre_key(struct gre_hdr *greh)
+{
+	if (!greh->key)
+		return NULL;
+	if (greh->csum || greh->routing)
+		return (u_int32_t *) (greh+sizeof(*greh)+4);
+	return (u_int32_t *) (greh+sizeof(*greh));
+}
+
+/* get pointer ot gre csum, if present */
+static inline u_int16_t *gre_csum(struct gre_hdr *greh)
+{
+	if (!greh->csum)
+		return NULL;
+	return (u_int16_t *) (greh+sizeof(*greh));
+}
+
+#endif /* __KERNEL__ */
+
+#endif /* _CONNTRACK_PROTO_GRE_H */