Patrick McHardy
f09943fefe
Add nf_conntrack port of the PPtP conntrack/NAT helper. Since there seems to be no IPv6-capable PPtP implementation the helper only support IPv4. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
113 lines
2.5 KiB
C
113 lines
2.5 KiB
C
#ifndef _CONNTRACK_PROTO_GRE_H
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#define _CONNTRACK_PROTO_GRE_H
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#include <asm/byteorder.h>
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/* GRE PROTOCOL HEADER */
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/* GRE Version field */
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#define GRE_VERSION_1701 0x0
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#define GRE_VERSION_PPTP 0x1
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/* GRE Protocol field */
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#define GRE_PROTOCOL_PPTP 0x880B
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/* GRE Flags */
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#define GRE_FLAG_C 0x80
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#define GRE_FLAG_R 0x40
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#define GRE_FLAG_K 0x20
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#define GRE_FLAG_S 0x10
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#define GRE_FLAG_A 0x80
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#define GRE_IS_C(f) ((f)&GRE_FLAG_C)
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#define GRE_IS_R(f) ((f)&GRE_FLAG_R)
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#define GRE_IS_K(f) ((f)&GRE_FLAG_K)
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#define GRE_IS_S(f) ((f)&GRE_FLAG_S)
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#define GRE_IS_A(f) ((f)&GRE_FLAG_A)
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/* GRE is a mess: Four different standards */
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struct gre_hdr {
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#if defined(__LITTLE_ENDIAN_BITFIELD)
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__u16 rec:3,
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srr:1,
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seq:1,
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key:1,
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routing:1,
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csum:1,
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version:3,
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reserved:4,
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ack:1;
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#elif defined(__BIG_ENDIAN_BITFIELD)
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__u16 csum:1,
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routing:1,
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key:1,
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seq:1,
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srr:1,
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rec:3,
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ack:1,
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reserved:4,
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version:3;
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#else
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#error "Adjust your <asm/byteorder.h> defines"
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#endif
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__be16 protocol;
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};
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/* modified GRE header for PPTP */
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struct gre_hdr_pptp {
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__u8 flags; /* bitfield */
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__u8 version; /* should be GRE_VERSION_PPTP */
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__be16 protocol; /* should be GRE_PROTOCOL_PPTP */
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__be16 payload_len; /* size of ppp payload, not inc. gre header */
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__be16 call_id; /* peer's call_id for this session */
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__be32 seq; /* sequence number. Present if S==1 */
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__be32 ack; /* seq number of highest packet recieved by */
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/* sender in this session */
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};
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struct nf_ct_gre {
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unsigned int stream_timeout;
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unsigned int timeout;
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};
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#ifdef __KERNEL__
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#include <net/netfilter/nf_conntrack_tuple.h>
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struct nf_conn;
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/* structure for original <-> reply keymap */
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struct nf_ct_gre_keymap {
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struct list_head list;
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struct nf_conntrack_tuple tuple;
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};
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/* add new tuple->key_reply pair to keymap */
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int nf_ct_gre_keymap_add(struct nf_conn *ct, enum ip_conntrack_dir dir,
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struct nf_conntrack_tuple *t);
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/* delete keymap entries */
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void nf_ct_gre_keymap_destroy(struct nf_conn *ct);
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/* get pointer to gre key, if present */
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static inline __be32 *gre_key(struct gre_hdr *greh)
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{
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if (!greh->key)
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return NULL;
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if (greh->csum || greh->routing)
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return (__be32 *)(greh+sizeof(*greh)+4);
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return (__be32 *)(greh+sizeof(*greh));
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}
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/* get pointer ot gre csum, if present */
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static inline __sum16 *gre_csum(struct gre_hdr *greh)
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{
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if (!greh->csum)
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return NULL;
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return (__sum16 *)(greh+sizeof(*greh));
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}
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extern void nf_ct_gre_keymap_flush(void);
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extern void nf_nat_need_gre(void);
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#endif /* __KERNEL__ */
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#endif /* _CONNTRACK_PROTO_GRE_H */
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