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141 lines
3.0 KiB
141 lines
3.0 KiB
#ifndef __LINUX_GRE_H |
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#define __LINUX_GRE_H |
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#include <linux/skbuff.h> |
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#include <net/ip_tunnels.h> |
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struct gre_base_hdr { |
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__be16 flags; |
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__be16 protocol; |
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} __packed; |
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struct gre_full_hdr { |
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struct gre_base_hdr fixed_header; |
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__be16 csum; |
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__be16 reserved1; |
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__be32 key; |
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__be32 seq; |
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} __packed; |
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#define GRE_HEADER_SECTION 4 |
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#define GREPROTO_CISCO 0 |
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#define GREPROTO_PPTP 1 |
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#define GREPROTO_MAX 2 |
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#define GRE_IP_PROTO_MAX 2 |
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struct gre_protocol { |
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int (*handler)(struct sk_buff *skb); |
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void (*err_handler)(struct sk_buff *skb, u32 info); |
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}; |
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int gre_add_protocol(const struct gre_protocol *proto, u8 version); |
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int gre_del_protocol(const struct gre_protocol *proto, u8 version); |
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struct net_device *gretap_fb_dev_create(struct net *net, const char *name, |
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u8 name_assign_type); |
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int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, |
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bool *csum_err, __be16 proto, int nhs); |
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static inline int gre_calc_hlen(__be16 o_flags) |
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{ |
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int addend = 4; |
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if (o_flags & TUNNEL_CSUM) |
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addend += 4; |
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if (o_flags & TUNNEL_KEY) |
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addend += 4; |
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if (o_flags & TUNNEL_SEQ) |
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addend += 4; |
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return addend; |
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} |
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static inline __be16 gre_flags_to_tnl_flags(__be16 flags) |
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{ |
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__be16 tflags = 0; |
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if (flags & GRE_CSUM) |
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tflags |= TUNNEL_CSUM; |
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if (flags & GRE_ROUTING) |
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tflags |= TUNNEL_ROUTING; |
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if (flags & GRE_KEY) |
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tflags |= TUNNEL_KEY; |
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if (flags & GRE_SEQ) |
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tflags |= TUNNEL_SEQ; |
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if (flags & GRE_STRICT) |
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tflags |= TUNNEL_STRICT; |
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if (flags & GRE_REC) |
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tflags |= TUNNEL_REC; |
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if (flags & GRE_VERSION) |
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tflags |= TUNNEL_VERSION; |
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return tflags; |
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} |
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static inline __be16 gre_tnl_flags_to_gre_flags(__be16 tflags) |
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{ |
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__be16 flags = 0; |
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if (tflags & TUNNEL_CSUM) |
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flags |= GRE_CSUM; |
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if (tflags & TUNNEL_ROUTING) |
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flags |= GRE_ROUTING; |
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if (tflags & TUNNEL_KEY) |
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flags |= GRE_KEY; |
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if (tflags & TUNNEL_SEQ) |
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flags |= GRE_SEQ; |
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if (tflags & TUNNEL_STRICT) |
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flags |= GRE_STRICT; |
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if (tflags & TUNNEL_REC) |
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flags |= GRE_REC; |
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if (tflags & TUNNEL_VERSION) |
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flags |= GRE_VERSION; |
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return flags; |
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} |
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static inline __sum16 gre_checksum(struct sk_buff *skb) |
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{ |
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__wsum csum; |
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if (skb->ip_summed == CHECKSUM_PARTIAL) |
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csum = lco_csum(skb); |
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else |
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csum = skb_checksum(skb, 0, skb->len, 0); |
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return csum_fold(csum); |
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} |
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static inline void gre_build_header(struct sk_buff *skb, int hdr_len, |
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__be16 flags, __be16 proto, |
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__be32 key, __be32 seq) |
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{ |
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struct gre_base_hdr *greh; |
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skb_push(skb, hdr_len); |
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skb_set_inner_protocol(skb, proto); |
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skb_reset_transport_header(skb); |
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greh = (struct gre_base_hdr *)skb->data; |
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greh->flags = gre_tnl_flags_to_gre_flags(flags); |
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greh->protocol = proto; |
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if (flags & (TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_SEQ)) { |
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__be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4); |
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if (flags & TUNNEL_SEQ) { |
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*ptr = seq; |
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ptr--; |
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} |
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if (flags & TUNNEL_KEY) { |
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*ptr = key; |
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ptr--; |
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} |
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if (flags & TUNNEL_CSUM && |
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!(skb_shinfo(skb)->gso_type & |
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(SKB_GSO_GRE | SKB_GSO_GRE_CSUM))) { |
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*ptr = 0; |
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*(__sum16 *)ptr = gre_checksum(skb); |
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} |
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} |
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} |
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#endif
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