/* SPDX-License-Identifier: GPL-2.0-or-later *//* *  SR-IPv6 implementation * *  Author: *  David Lebrun <david.lebrun@uclouvain.be> */ #ifndef _NET_SEG6_H#define _NET_SEG6_H #include <linux/net.h>#include <linux/ipv6.h>#include <linux/seg6.h>#include <linux/rhashtable-types.h> static inline void update_csum_diff4(struct sk_buff *skb, __be32 from,				     __be32 to){	__be32 diff[] = { ~from, to }; 	skb->csum = ~csum_partial((char *)diff, sizeof(diff), ~skb->csum);} static inline void update_csum_diff16(struct sk_buff *skb, __be32 *from,				      __be32 *to){	__be32 diff[] = {		~from[0], ~from[1], ~from[2], ~from[3],		to[0], to[1], to[2], to[3],	}; 	skb->csum = ~csum_partial((char *)diff, sizeof(diff), ~skb->csum);} struct seg6_pernet_data {	struct mutex lock;	struct in6_addr __rcu *tun_src;#ifdef CONFIG_IPV6_SEG6_HMAC	struct rhashtable hmac_infos;#endif}; static inline struct seg6_pernet_data *seg6_pernet(struct net *net){#if IS_ENABLED(CONFIG_IPV6)	return net->ipv6.seg6_data;#else	return NULL;#endif} extern int seg6_init(void);extern void seg6_exit(void);#ifdef CONFIG_IPV6_SEG6_LWTUNNELextern int seg6_iptunnel_init(void);extern void seg6_iptunnel_exit(void);extern int seg6_local_init(void);extern void seg6_local_exit(void);#elsestatic inline int seg6_iptunnel_init(void) { return 0; }static inline void seg6_iptunnel_exit(void) {}static inline int seg6_local_init(void) { return 0; }static inline void seg6_local_exit(void) {}#endif extern bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len, bool reduced);extern struct ipv6_sr_hdr *seg6_get_srh(struct sk_buff *skb, int flags);extern void seg6_icmp_srh(struct sk_buff *skb, struct inet6_skb_parm *opt);extern int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh,			     int proto);extern int seg6_do_srh_inline(struct sk_buff *skb, struct ipv6_sr_hdr *osrh);extern int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,			       u32 tbl_id); /* If the packet which invoked an ICMP error contains an SRH return * the true destination address from within the SRH, otherwise use the * destination address in the IP header. */static inline const struct in6_addr *seg6_get_daddr(struct sk_buff *skb,						    struct inet6_skb_parm *opt){	struct ipv6_sr_hdr *srh; 	if (opt->flags & IP6SKB_SEG6) {		srh = (struct ipv6_sr_hdr *)(skb->data + opt->srhoff);		return  &srh->segments[0];	} 	return NULL;}  #endif