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Diffstat (limited to '')
| -rw-r--r-- | include/net/gre.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/include/net/gre.h b/include/net/gre.h new file mode 100644 index 000000000..b60f212c1 --- /dev/null +++ b/include/net/gre.h @@ -0,0 +1,154 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __LINUX_GRE_H +#define __LINUX_GRE_H + +#include <linux/skbuff.h> +#include <net/ip_tunnels.h> + +struct gre_base_hdr { + __be16 flags; + __be16 protocol; +} __packed; + +struct gre_full_hdr { + struct gre_base_hdr fixed_header; + __be16 csum; + __be16 reserved1; + __be32 key; + __be32 seq; +} __packed; +#define GRE_HEADER_SECTION 4 + +#define GREPROTO_CISCO 0 +#define GREPROTO_PPTP 1 +#define GREPROTO_MAX 2 +#define GRE_IP_PROTO_MAX 2 + +struct gre_protocol { + int (*handler)(struct sk_buff *skb); + void (*err_handler)(struct sk_buff *skb, u32 info); +}; + +int gre_add_protocol(const struct gre_protocol *proto, u8 version); +int gre_del_protocol(const struct gre_protocol *proto, u8 version); + +struct net_device *gretap_fb_dev_create(struct net *net, const char *name, + u8 name_assign_type); +int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, + bool *csum_err, __be16 proto, int nhs); + +static inline bool netif_is_gretap(const struct net_device *dev) +{ + return dev->rtnl_link_ops && + !strcmp(dev->rtnl_link_ops->kind, "gretap"); +} + +static inline bool netif_is_ip6gretap(const struct net_device *dev) +{ + return dev->rtnl_link_ops && + !strcmp(dev->rtnl_link_ops->kind, "ip6gretap"); +} + +static inline int gre_calc_hlen(__be16 o_flags) +{ + int addend = 4; + + if (o_flags & TUNNEL_CSUM) + addend += 4; + if (o_flags & TUNNEL_KEY) + addend += 4; + if (o_flags & TUNNEL_SEQ) + addend += 4; + return addend; +} + +static inline __be16 gre_flags_to_tnl_flags(__be16 flags) +{ + __be16 tflags = 0; + + if (flags & GRE_CSUM) + tflags |= TUNNEL_CSUM; + if (flags & GRE_ROUTING) + tflags |= TUNNEL_ROUTING; + if (flags & GRE_KEY) + tflags |= TUNNEL_KEY; + if (flags & GRE_SEQ) + tflags |= TUNNEL_SEQ; + if (flags & GRE_STRICT) + tflags |= TUNNEL_STRICT; + if (flags & GRE_REC) + tflags |= TUNNEL_REC; + if (flags & GRE_VERSION) + tflags |= TUNNEL_VERSION; + + return tflags; +} + +static inline __be16 gre_tnl_flags_to_gre_flags(__be16 tflags) +{ + __be16 flags = 0; + + if (tflags & TUNNEL_CSUM) + flags |= GRE_CSUM; + if (tflags & TUNNEL_ROUTING) + flags |= GRE_ROUTING; + if (tflags & TUNNEL_KEY) + flags |= GRE_KEY; + if (tflags & TUNNEL_SEQ) + flags |= GRE_SEQ; + if (tflags & TUNNEL_STRICT) + flags |= GRE_STRICT; + if (tflags & TUNNEL_REC) + flags |= GRE_REC; + if (tflags & TUNNEL_VERSION) + flags |= GRE_VERSION; + + return flags; +} + +static inline __sum16 gre_checksum(struct sk_buff *skb) +{ + __wsum csum; + + if (skb->ip_summed == CHECKSUM_PARTIAL) + csum = lco_csum(skb); + else + csum = skb_checksum(skb, 0, skb->len, 0); + return csum_fold(csum); +} + +static inline void gre_build_header(struct sk_buff *skb, int hdr_len, + __be16 flags, __be16 proto, + __be32 key, __be32 seq) +{ + struct gre_base_hdr *greh; + + skb_push(skb, hdr_len); + + skb_set_inner_protocol(skb, proto); + skb_reset_transport_header(skb); + greh = (struct gre_base_hdr *)skb->data; + greh->flags = gre_tnl_flags_to_gre_flags(flags); + greh->protocol = proto; + + if (flags & (TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_SEQ)) { + __be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4); + + if (flags & TUNNEL_SEQ) { + *ptr = seq; + ptr--; + } + if (flags & TUNNEL_KEY) { + *ptr = key; + ptr--; + } + if (flags & TUNNEL_CSUM && + !(skb_shinfo(skb)->gso_type & + (SKB_GSO_GRE | SKB_GSO_GRE_CSUM))) { + *ptr = 0; + *(__sum16 *)ptr = gre_checksum(skb); + } + } +} + +#endif |