Commit | Line | Data |
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b59f45d0 HX |
1 | /* |
2 | * xfrm6_mode_tunnel.c - Tunnel mode encapsulation for IPv6. | |
3 | * | |
4 | * Copyright (C) 2002 USAGI/WIDE Project | |
5 | * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au> | |
6 | */ | |
7 | ||
8 | #include <linux/init.h> | |
9 | #include <linux/kernel.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/skbuff.h> | |
12 | #include <linux/stringify.h> | |
13 | #include <net/dsfield.h> | |
14 | #include <net/dst.h> | |
15 | #include <net/inet_ecn.h> | |
16 | #include <net/ipv6.h> | |
17 | #include <net/xfrm.h> | |
18 | ||
19 | static inline void ipip6_ecn_decapsulate(struct sk_buff *skb) | |
20 | { | |
0660e03f | 21 | struct ipv6hdr *outer_iph = ipv6_hdr(skb); |
39b89160 | 22 | struct ipv6hdr *inner_iph = ipipv6_hdr(skb); |
b59f45d0 HX |
23 | |
24 | if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph))) | |
25 | IP6_ECN_set_ce(inner_iph); | |
26 | } | |
27 | ||
43372262 MK |
28 | static inline void ip6ip_ecn_decapsulate(struct sk_buff *skb) |
29 | { | |
0660e03f | 30 | if (INET_ECN_is_ce(ipv6_get_dsfield(ipv6_hdr(skb)))) |
b0061ce4 | 31 | IP_ECN_set_ce(ipip_hdr(skb)); |
43372262 MK |
32 | } |
33 | ||
b59f45d0 HX |
34 | /* Add encapsulation header. |
35 | * | |
36 | * The top IP header will be constructed per RFC 2401. The following fields | |
37 | * in it shall be filled in by x->type->output: | |
38 | * payload_len | |
39 | * | |
40 | * On exit, skb->h will be set to the start of the encapsulation header to be | |
007f0211 HX |
41 | * filled in by x->type->output and the mac header will be set to the |
42 | * nextheader field of the extension header directly preceding the | |
43 | * encapsulation header, or in its absence, that of the top IP header. | |
7b277b1a HX |
44 | * The value of the network header will always point to the top IP header |
45 | * while skb->data will point to the payload. | |
b59f45d0 | 46 | */ |
eb878e84 | 47 | static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) |
b59f45d0 HX |
48 | { |
49 | struct dst_entry *dst = skb->dst; | |
43372262 | 50 | struct xfrm_dst *xdst = (struct xfrm_dst*)dst; |
b59f45d0 HX |
51 | struct ipv6hdr *iph, *top_iph; |
52 | int dsfield; | |
53 | ||
0660e03f | 54 | iph = ipv6_hdr(skb); |
b59f45d0 | 55 | |
7b277b1a HX |
56 | skb_set_mac_header(skb, offsetof(struct ipv6hdr, nexthdr) - |
57 | x->props.header_len); | |
58 | skb_set_network_header(skb, -x->props.header_len); | |
59 | skb_set_transport_header(skb, sizeof(struct ipv6hdr) - | |
60 | x->props.header_len); | |
0660e03f | 61 | top_iph = ipv6_hdr(skb); |
b59f45d0 HX |
62 | |
63 | top_iph->version = 6; | |
43372262 MK |
64 | if (xdst->route->ops->family == AF_INET6) { |
65 | top_iph->priority = iph->priority; | |
66 | top_iph->flow_lbl[0] = iph->flow_lbl[0]; | |
67 | top_iph->flow_lbl[1] = iph->flow_lbl[1]; | |
68 | top_iph->flow_lbl[2] = iph->flow_lbl[2]; | |
69 | top_iph->nexthdr = IPPROTO_IPV6; | |
70 | } else { | |
71 | top_iph->priority = 0; | |
72 | top_iph->flow_lbl[0] = 0; | |
73 | top_iph->flow_lbl[1] = 0; | |
74 | top_iph->flow_lbl[2] = 0; | |
75 | top_iph->nexthdr = IPPROTO_IPIP; | |
76 | } | |
b59f45d0 HX |
77 | dsfield = ipv6_get_dsfield(top_iph); |
78 | dsfield = INET_ECN_encapsulate(dsfield, dsfield); | |
79 | if (x->props.flags & XFRM_STATE_NOECN) | |
80 | dsfield &= ~INET_ECN_MASK; | |
81 | ipv6_change_dsfield(top_iph, 0, dsfield); | |
b59f45d0 HX |
82 | top_iph->hop_limit = dst_metric(dst->child, RTAX_HOPLIMIT); |
83 | ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr); | |
84 | ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr); | |
f282d45c | 85 | skb->protocol = htons(ETH_P_IPV6); |
b59f45d0 HX |
86 | return 0; |
87 | } | |
88 | ||
89 | static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) | |
90 | { | |
91 | int err = -EINVAL; | |
39f69c6f | 92 | const unsigned char *old_mac; |
d56f90a7 | 93 | const unsigned char *nh = skb_network_header(skb); |
b59f45d0 | 94 | |
d56f90a7 ACM |
95 | if (nh[IP6CB(skb)->nhoff] != IPPROTO_IPV6 && |
96 | nh[IP6CB(skb)->nhoff] != IPPROTO_IPIP) | |
b59f45d0 HX |
97 | goto out; |
98 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
99 | goto out; | |
100 | ||
101 | if (skb_cloned(skb) && | |
102 | (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC))) | |
103 | goto out; | |
104 | ||
d56f90a7 ACM |
105 | nh = skb_network_header(skb); |
106 | if (nh[IP6CB(skb)->nhoff] == IPPROTO_IPV6) { | |
43372262 | 107 | if (x->props.flags & XFRM_STATE_DECAP_DSCP) |
39b89160 | 108 | ipv6_copy_dscp(ipv6_hdr(skb), ipipv6_hdr(skb)); |
43372262 MK |
109 | if (!(x->props.flags & XFRM_STATE_NOECN)) |
110 | ipip6_ecn_decapsulate(skb); | |
111 | } else { | |
112 | if (!(x->props.flags & XFRM_STATE_NOECN)) | |
113 | ip6ip_ecn_decapsulate(skb); | |
114 | skb->protocol = htons(ETH_P_IP); | |
115 | } | |
98e399f8 | 116 | old_mac = skb_mac_header(skb); |
39f69c6f | 117 | skb_set_mac_header(skb, -skb->mac_len); |
98e399f8 | 118 | memmove(skb_mac_header(skb), old_mac, skb->mac_len); |
c1d2bbe1 | 119 | skb_reset_network_header(skb); |
b59f45d0 HX |
120 | err = 0; |
121 | ||
122 | out: | |
123 | return err; | |
124 | } | |
125 | ||
126 | static struct xfrm_mode xfrm6_tunnel_mode = { | |
127 | .input = xfrm6_tunnel_input, | |
128 | .output = xfrm6_tunnel_output, | |
129 | .owner = THIS_MODULE, | |
130 | .encap = XFRM_MODE_TUNNEL, | |
131 | }; | |
132 | ||
133 | static int __init xfrm6_tunnel_init(void) | |
134 | { | |
135 | return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6); | |
136 | } | |
137 | ||
138 | static void __exit xfrm6_tunnel_exit(void) | |
139 | { | |
140 | int err; | |
141 | ||
142 | err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6); | |
143 | BUG_ON(err); | |
144 | } | |
145 | ||
146 | module_init(xfrm6_tunnel_init); | |
147 | module_exit(xfrm6_tunnel_exit); | |
148 | MODULE_LICENSE("GPL"); | |
149 | MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL); |