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 | |
41 | * filled in by x->type->output and skb->nh will be set to the nextheader field | |
42 | * of the extension header directly preceding the encapsulation header, or in | |
43 | * its absence, that of the top IP header. The value of skb->data will always | |
44 | * point to the top IP header. | |
45 | */ | |
eb878e84 | 46 | static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) |
b59f45d0 HX |
47 | { |
48 | struct dst_entry *dst = skb->dst; | |
43372262 | 49 | struct xfrm_dst *xdst = (struct xfrm_dst*)dst; |
b59f45d0 HX |
50 | struct ipv6hdr *iph, *top_iph; |
51 | int dsfield; | |
52 | ||
53 | skb_push(skb, x->props.header_len); | |
0660e03f | 54 | iph = ipv6_hdr(skb); |
b59f45d0 | 55 | |
c1d2bbe1 | 56 | skb_reset_network_header(skb); |
0660e03f | 57 | top_iph = ipv6_hdr(skb); |
b0e380b1 ACM |
58 | skb->transport_header = skb->network_header + sizeof(struct ipv6hdr); |
59 | skb->network_header += offsetof(struct ipv6hdr, nexthdr); | |
b59f45d0 HX |
60 | |
61 | top_iph->version = 6; | |
43372262 MK |
62 | if (xdst->route->ops->family == AF_INET6) { |
63 | top_iph->priority = iph->priority; | |
64 | top_iph->flow_lbl[0] = iph->flow_lbl[0]; | |
65 | top_iph->flow_lbl[1] = iph->flow_lbl[1]; | |
66 | top_iph->flow_lbl[2] = iph->flow_lbl[2]; | |
67 | top_iph->nexthdr = IPPROTO_IPV6; | |
68 | } else { | |
69 | top_iph->priority = 0; | |
70 | top_iph->flow_lbl[0] = 0; | |
71 | top_iph->flow_lbl[1] = 0; | |
72 | top_iph->flow_lbl[2] = 0; | |
73 | top_iph->nexthdr = IPPROTO_IPIP; | |
74 | } | |
b59f45d0 HX |
75 | dsfield = ipv6_get_dsfield(top_iph); |
76 | dsfield = INET_ECN_encapsulate(dsfield, dsfield); | |
77 | if (x->props.flags & XFRM_STATE_NOECN) | |
78 | dsfield &= ~INET_ECN_MASK; | |
79 | ipv6_change_dsfield(top_iph, 0, dsfield); | |
b59f45d0 HX |
80 | top_iph->hop_limit = dst_metric(dst->child, RTAX_HOPLIMIT); |
81 | ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr); | |
82 | ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr); | |
f282d45c | 83 | skb->protocol = htons(ETH_P_IPV6); |
b59f45d0 HX |
84 | return 0; |
85 | } | |
86 | ||
87 | static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) | |
88 | { | |
89 | int err = -EINVAL; | |
39f69c6f | 90 | const unsigned char *old_mac; |
d56f90a7 | 91 | const unsigned char *nh = skb_network_header(skb); |
b59f45d0 | 92 | |
d56f90a7 ACM |
93 | if (nh[IP6CB(skb)->nhoff] != IPPROTO_IPV6 && |
94 | nh[IP6CB(skb)->nhoff] != IPPROTO_IPIP) | |
b59f45d0 HX |
95 | goto out; |
96 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
97 | goto out; | |
98 | ||
99 | if (skb_cloned(skb) && | |
100 | (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC))) | |
101 | goto out; | |
102 | ||
d56f90a7 ACM |
103 | nh = skb_network_header(skb); |
104 | if (nh[IP6CB(skb)->nhoff] == IPPROTO_IPV6) { | |
43372262 | 105 | if (x->props.flags & XFRM_STATE_DECAP_DSCP) |
39b89160 | 106 | ipv6_copy_dscp(ipv6_hdr(skb), ipipv6_hdr(skb)); |
43372262 MK |
107 | if (!(x->props.flags & XFRM_STATE_NOECN)) |
108 | ipip6_ecn_decapsulate(skb); | |
109 | } else { | |
110 | if (!(x->props.flags & XFRM_STATE_NOECN)) | |
111 | ip6ip_ecn_decapsulate(skb); | |
112 | skb->protocol = htons(ETH_P_IP); | |
113 | } | |
98e399f8 | 114 | old_mac = skb_mac_header(skb); |
39f69c6f | 115 | skb_set_mac_header(skb, -skb->mac_len); |
98e399f8 | 116 | memmove(skb_mac_header(skb), old_mac, skb->mac_len); |
c1d2bbe1 | 117 | skb_reset_network_header(skb); |
b59f45d0 HX |
118 | err = 0; |
119 | ||
120 | out: | |
121 | return err; | |
122 | } | |
123 | ||
124 | static struct xfrm_mode xfrm6_tunnel_mode = { | |
125 | .input = xfrm6_tunnel_input, | |
126 | .output = xfrm6_tunnel_output, | |
127 | .owner = THIS_MODULE, | |
128 | .encap = XFRM_MODE_TUNNEL, | |
129 | }; | |
130 | ||
131 | static int __init xfrm6_tunnel_init(void) | |
132 | { | |
133 | return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6); | |
134 | } | |
135 | ||
136 | static void __exit xfrm6_tunnel_exit(void) | |
137 | { | |
138 | int err; | |
139 | ||
140 | err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6); | |
141 | BUG_ON(err); | |
142 | } | |
143 | ||
144 | module_init(xfrm6_tunnel_init); | |
145 | module_exit(xfrm6_tunnel_exit); | |
146 | MODULE_LICENSE("GPL"); | |
147 | MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL); |