Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * xfrm6_input.c: based on net/ipv4/xfrm4_input.c | |
3 | * | |
4 | * Authors: | |
5 | * Mitsuru KANDA @USAGI | |
6 | * Kazunori MIYAZAWA @USAGI | |
7 | * Kunihiro Ishiguro <kunihiro@ipinfusion.com> | |
8 | * YOSHIFUJI Hideaki @USAGI | |
9 | * IPv6 support | |
10 | */ | |
11 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/string.h> | |
b05e1066 PM |
14 | #include <linux/netfilter.h> |
15 | #include <linux/netfilter_ipv6.h> | |
1da177e4 LT |
16 | #include <net/dsfield.h> |
17 | #include <net/inet_ecn.h> | |
18 | #include <net/ip.h> | |
19 | #include <net/ipv6.h> | |
20 | #include <net/xfrm.h> | |
21 | ||
22 | static inline void ipip6_ecn_decapsulate(struct sk_buff *skb) | |
23 | { | |
24 | struct ipv6hdr *outer_iph = skb->nh.ipv6h; | |
25 | struct ipv6hdr *inner_iph = skb->h.ipv6h; | |
26 | ||
27 | if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph))) | |
28 | IP6_ECN_set_ce(inner_iph); | |
29 | } | |
30 | ||
951dbc8a | 31 | int xfrm6_rcv_spi(struct sk_buff **pskb, u32 spi) |
1da177e4 LT |
32 | { |
33 | struct sk_buff *skb = *pskb; | |
34 | int err; | |
35 | u32 seq; | |
36 | struct sec_decap_state xfrm_vec[XFRM_MAX_DEPTH]; | |
37 | struct xfrm_state *x; | |
38 | int xfrm_nr = 0; | |
39 | int decaps = 0; | |
40 | int nexthdr; | |
41 | unsigned int nhoff; | |
42 | ||
951dbc8a | 43 | nhoff = IP6CB(skb)->nhoff; |
1da177e4 LT |
44 | nexthdr = skb->nh.raw[nhoff]; |
45 | ||
46 | seq = 0; | |
47 | if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0) | |
48 | goto drop; | |
49 | ||
50 | do { | |
51 | struct ipv6hdr *iph = skb->nh.ipv6h; | |
52 | ||
53 | if (xfrm_nr == XFRM_MAX_DEPTH) | |
54 | goto drop; | |
55 | ||
56 | x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, nexthdr, AF_INET6); | |
57 | if (x == NULL) | |
58 | goto drop; | |
59 | spin_lock(&x->lock); | |
60 | if (unlikely(x->km.state != XFRM_STATE_VALID)) | |
61 | goto drop_unlock; | |
62 | ||
63 | if (x->props.replay_window && xfrm_replay_check(x, seq)) | |
64 | goto drop_unlock; | |
65 | ||
66 | if (xfrm_state_check_expire(x)) | |
67 | goto drop_unlock; | |
68 | ||
69 | nexthdr = x->type->input(x, &(xfrm_vec[xfrm_nr].decap), skb); | |
70 | if (nexthdr <= 0) | |
71 | goto drop_unlock; | |
72 | ||
73 | skb->nh.raw[nhoff] = nexthdr; | |
74 | ||
75 | if (x->props.replay_window) | |
76 | xfrm_replay_advance(x, seq); | |
77 | ||
78 | x->curlft.bytes += skb->len; | |
79 | x->curlft.packets++; | |
80 | ||
81 | spin_unlock(&x->lock); | |
82 | ||
83 | xfrm_vec[xfrm_nr++].xvec = x; | |
84 | ||
85 | if (x->props.mode) { /* XXX */ | |
86 | if (nexthdr != IPPROTO_IPV6) | |
87 | goto drop; | |
88 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
89 | goto drop; | |
90 | if (skb_cloned(skb) && | |
91 | pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) | |
92 | goto drop; | |
93 | if (x->props.flags & XFRM_STATE_DECAP_DSCP) | |
94 | ipv6_copy_dscp(skb->nh.ipv6h, skb->h.ipv6h); | |
95 | if (!(x->props.flags & XFRM_STATE_NOECN)) | |
96 | ipip6_ecn_decapsulate(skb); | |
97 | skb->mac.raw = memmove(skb->data - skb->mac_len, | |
98 | skb->mac.raw, skb->mac_len); | |
99 | skb->nh.raw = skb->data; | |
100 | decaps = 1; | |
101 | break; | |
102 | } | |
103 | ||
104 | if ((err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) < 0) | |
105 | goto drop; | |
106 | } while (!err); | |
107 | ||
108 | /* Allocate new secpath or COW existing one. */ | |
109 | if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) { | |
110 | struct sec_path *sp; | |
111 | sp = secpath_dup(skb->sp); | |
112 | if (!sp) | |
113 | goto drop; | |
114 | if (skb->sp) | |
115 | secpath_put(skb->sp); | |
116 | skb->sp = sp; | |
117 | } | |
118 | ||
119 | if (xfrm_nr + skb->sp->len > XFRM_MAX_DEPTH) | |
120 | goto drop; | |
121 | ||
122 | memcpy(skb->sp->x+skb->sp->len, xfrm_vec, xfrm_nr*sizeof(struct sec_decap_state)); | |
123 | skb->sp->len += xfrm_nr; | |
124 | skb->ip_summed = CHECKSUM_NONE; | |
125 | ||
b05e1066 PM |
126 | nf_reset(skb); |
127 | ||
1da177e4 LT |
128 | if (decaps) { |
129 | if (!(skb->dev->flags&IFF_LOOPBACK)) { | |
130 | dst_release(skb->dst); | |
131 | skb->dst = NULL; | |
132 | } | |
133 | netif_rx(skb); | |
134 | return -1; | |
135 | } else { | |
b05e1066 PM |
136 | #ifdef CONFIG_NETFILTER |
137 | skb->nh.ipv6h->payload_len = htons(skb->len); | |
138 | __skb_push(skb, skb->data - skb->nh.raw); | |
139 | ||
140 | NF_HOOK(PF_INET6, NF_IP6_PRE_ROUTING, skb, skb->dev, NULL, | |
141 | ip6_rcv_finish); | |
142 | return -1; | |
143 | #else | |
1da177e4 | 144 | return 1; |
b05e1066 | 145 | #endif |
1da177e4 LT |
146 | } |
147 | ||
148 | drop_unlock: | |
149 | spin_unlock(&x->lock); | |
150 | xfrm_state_put(x); | |
151 | drop: | |
152 | while (--xfrm_nr >= 0) | |
153 | xfrm_state_put(xfrm_vec[xfrm_nr].xvec); | |
154 | kfree_skb(skb); | |
155 | return -1; | |
156 | } | |
157 | ||
158 | EXPORT_SYMBOL(xfrm6_rcv_spi); | |
159 | ||
951dbc8a | 160 | int xfrm6_rcv(struct sk_buff **pskb) |
1da177e4 | 161 | { |
951dbc8a | 162 | return xfrm6_rcv_spi(pskb, 0); |
1da177e4 | 163 | } |