xref: /linux/include/net/dst_metadata.h (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 #ifndef __NET_DST_METADATA_H
2 #define __NET_DST_METADATA_H 1
3 
4 #include <linux/skbuff.h>
5 #include <net/ip_tunnels.h>
6 #include <net/dst.h>
7 
8 struct metadata_dst {
9 	struct dst_entry		dst;
10 	union {
11 		struct ip_tunnel_info	tun_info;
12 	} u;
13 };
14 
15 static inline struct metadata_dst *skb_metadata_dst(struct sk_buff *skb)
16 {
17 	struct metadata_dst *md_dst = (struct metadata_dst *) skb_dst(skb);
18 
19 	if (md_dst && md_dst->dst.flags & DST_METADATA)
20 		return md_dst;
21 
22 	return NULL;
23 }
24 
25 static inline struct ip_tunnel_info *skb_tunnel_info(struct sk_buff *skb)
26 {
27 	struct metadata_dst *md_dst = skb_metadata_dst(skb);
28 	struct dst_entry *dst;
29 
30 	if (md_dst)
31 		return &md_dst->u.tun_info;
32 
33 	dst = skb_dst(skb);
34 	if (dst && dst->lwtstate)
35 		return lwt_tun_info(dst->lwtstate);
36 
37 	return NULL;
38 }
39 
40 static inline bool skb_valid_dst(const struct sk_buff *skb)
41 {
42 	struct dst_entry *dst = skb_dst(skb);
43 
44 	return dst && !(dst->flags & DST_METADATA);
45 }
46 
47 struct metadata_dst *metadata_dst_alloc(u8 optslen, gfp_t flags);
48 struct metadata_dst __percpu *metadata_dst_alloc_percpu(u8 optslen, gfp_t flags);
49 
50 static inline struct metadata_dst *tun_rx_dst(int md_size)
51 {
52 	struct metadata_dst *tun_dst;
53 
54 	tun_dst = metadata_dst_alloc(md_size, GFP_ATOMIC);
55 	if (!tun_dst)
56 		return NULL;
57 
58 	tun_dst->u.tun_info.options_len = 0;
59 	tun_dst->u.tun_info.mode = 0;
60 	return tun_dst;
61 }
62 
63 static inline struct metadata_dst *tun_dst_unclone(struct sk_buff *skb)
64 {
65 	struct metadata_dst *md_dst = skb_metadata_dst(skb);
66 	int md_size = md_dst->u.tun_info.options_len;
67 	struct metadata_dst *new_md;
68 
69 	if (!md_dst)
70 		return ERR_PTR(-EINVAL);
71 
72 	new_md = metadata_dst_alloc(md_size, GFP_ATOMIC);
73 	if (!new_md)
74 		return ERR_PTR(-ENOMEM);
75 
76 	memcpy(&new_md->u.tun_info, &md_dst->u.tun_info,
77 	       sizeof(struct ip_tunnel_info) + md_size);
78 	skb_dst_drop(skb);
79 	dst_hold(&new_md->dst);
80 	skb_dst_set(skb, &new_md->dst);
81 	return new_md;
82 }
83 
84 static inline struct ip_tunnel_info *skb_tunnel_info_unclone(struct sk_buff *skb)
85 {
86 	struct metadata_dst *dst;
87 
88 	dst = tun_dst_unclone(skb);
89 	if (IS_ERR(dst))
90 		return NULL;
91 
92 	return &dst->u.tun_info;
93 }
94 
95 static inline struct metadata_dst *ip_tun_rx_dst(struct sk_buff *skb,
96 						 __be16 flags,
97 						 __be64 tunnel_id,
98 						 int md_size)
99 {
100 	const struct iphdr *iph = ip_hdr(skb);
101 	struct metadata_dst *tun_dst;
102 
103 	tun_dst = tun_rx_dst(md_size);
104 	if (!tun_dst)
105 		return NULL;
106 
107 	ip_tunnel_key_init(&tun_dst->u.tun_info.key,
108 			   iph->saddr, iph->daddr, iph->tos, iph->ttl,
109 			   0, 0, tunnel_id, flags);
110 	return tun_dst;
111 }
112 
113 static inline struct metadata_dst *ipv6_tun_rx_dst(struct sk_buff *skb,
114 						 __be16 flags,
115 						 __be64 tunnel_id,
116 						 int md_size)
117 {
118 	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
119 	struct metadata_dst *tun_dst;
120 	struct ip_tunnel_info *info;
121 
122 	tun_dst = tun_rx_dst(md_size);
123 	if (!tun_dst)
124 		return NULL;
125 
126 	info = &tun_dst->u.tun_info;
127 	info->mode = IP_TUNNEL_INFO_IPV6;
128 	info->key.tun_flags = flags;
129 	info->key.tun_id = tunnel_id;
130 	info->key.tp_src = 0;
131 	info->key.tp_dst = 0;
132 
133 	info->key.u.ipv6.src = ip6h->saddr;
134 	info->key.u.ipv6.dst = ip6h->daddr;
135 	info->key.tos = ipv6_get_dsfield(ip6h);
136 	info->key.ttl = ip6h->hop_limit;
137 	return tun_dst;
138 }
139 
140 #endif /* __NET_DST_METADATA_H */
141