xref: /linux/include/net/seg6.h (revision 55d0969c451159cff86949b38c39171cab962069)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  *  SR-IPv6 implementation
4  *
5  *  Author:
6  *  David Lebrun <david.lebrun@uclouvain.be>
7  */
8 
9 #ifndef _NET_SEG6_H
10 #define _NET_SEG6_H
11 
12 #include <linux/net.h>
13 #include <linux/ipv6.h>
14 #include <linux/seg6.h>
15 #include <linux/rhashtable-types.h>
16 
17 static inline void update_csum_diff4(struct sk_buff *skb, __be32 from,
18 				     __be32 to)
19 {
20 	__be32 diff[] = { ~from, to };
21 
22 	skb->csum = ~csum_partial((char *)diff, sizeof(diff), ~skb->csum);
23 }
24 
25 static inline void update_csum_diff16(struct sk_buff *skb, __be32 *from,
26 				      __be32 *to)
27 {
28 	__be32 diff[] = {
29 		~from[0], ~from[1], ~from[2], ~from[3],
30 		to[0], to[1], to[2], to[3],
31 	};
32 
33 	skb->csum = ~csum_partial((char *)diff, sizeof(diff), ~skb->csum);
34 }
35 
36 struct seg6_pernet_data {
37 	struct mutex lock;
38 	struct in6_addr __rcu *tun_src;
39 #ifdef CONFIG_IPV6_SEG6_HMAC
40 	struct rhashtable hmac_infos;
41 #endif
42 };
43 
44 static inline struct seg6_pernet_data *seg6_pernet(struct net *net)
45 {
46 #if IS_ENABLED(CONFIG_IPV6)
47 	return net->ipv6.seg6_data;
48 #else
49 	return NULL;
50 #endif
51 }
52 
53 extern int seg6_init(void);
54 extern void seg6_exit(void);
55 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL
56 extern int seg6_iptunnel_init(void);
57 extern void seg6_iptunnel_exit(void);
58 extern int seg6_local_init(void);
59 extern void seg6_local_exit(void);
60 #else
61 static inline int seg6_iptunnel_init(void) { return 0; }
62 static inline void seg6_iptunnel_exit(void) {}
63 static inline int seg6_local_init(void) { return 0; }
64 static inline void seg6_local_exit(void) {}
65 #endif
66 
67 extern bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len, bool reduced);
68 extern struct ipv6_sr_hdr *seg6_get_srh(struct sk_buff *skb, int flags);
69 extern void seg6_icmp_srh(struct sk_buff *skb, struct inet6_skb_parm *opt);
70 extern int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh,
71 			     int proto);
72 extern int seg6_do_srh_inline(struct sk_buff *skb, struct ipv6_sr_hdr *osrh);
73 extern int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,
74 			       u32 tbl_id);
75 
76 /* If the packet which invoked an ICMP error contains an SRH return
77  * the true destination address from within the SRH, otherwise use the
78  * destination address in the IP header.
79  */
80 static inline const struct in6_addr *seg6_get_daddr(struct sk_buff *skb,
81 						    struct inet6_skb_parm *opt)
82 {
83 	struct ipv6_sr_hdr *srh;
84 
85 	if (opt->flags & IP6SKB_SEG6) {
86 		srh = (struct ipv6_sr_hdr *)(skb->data + opt->srhoff);
87 		return  &srh->segments[0];
88 	}
89 
90 	return NULL;
91 }
92 
93 
94 #endif
95