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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * xfrm4_input.c | |
3 | * | |
4 | * Changes: | |
5 | * YOSHIFUJI Hideaki @USAGI | |
6 | * Split up af-specific portion | |
7 | * Derek Atkins <derek@ihtfp.com> | |
8 | * Add Encapsulation support | |
e905a9ed | 9 | * |
1da177e4 LT |
10 | */ |
11 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/string.h> | |
b05e1066 PM |
14 | #include <linux/netfilter.h> |
15 | #include <linux/netfilter_ipv4.h> | |
1da177e4 LT |
16 | #include <net/ip.h> |
17 | #include <net/xfrm.h> | |
18 | ||
19 | int xfrm4_rcv(struct sk_buff *skb) | |
20 | { | |
21 | return xfrm4_rcv_encap(skb, 0); | |
22 | } | |
23 | ||
24 | EXPORT_SYMBOL(xfrm4_rcv); | |
25 | ||
6067b2ba | 26 | static int xfrm4_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq) |
1da177e4 LT |
27 | { |
28 | switch (nexthdr) { | |
29 | case IPPROTO_IPIP: | |
c0d56408 | 30 | case IPPROTO_IPV6: |
eddc9ec5 | 31 | *spi = ip_hdr(skb)->saddr; |
1da177e4 LT |
32 | *seq = 0; |
33 | return 0; | |
34 | } | |
35 | ||
36 | return xfrm_parse_spi(skb, nexthdr, spi, seq); | |
37 | } | |
38 | ||
b05e1066 PM |
39 | #ifdef CONFIG_NETFILTER |
40 | static inline int xfrm4_rcv_encap_finish(struct sk_buff *skb) | |
41 | { | |
b05e1066 | 42 | if (skb->dst == NULL) { |
eddc9ec5 ACM |
43 | const struct iphdr *iph = ip_hdr(skb); |
44 | ||
b05e1066 | 45 | if (ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, |
e905a9ed | 46 | skb->dev)) |
b05e1066 PM |
47 | goto drop; |
48 | } | |
49 | return dst_input(skb); | |
50 | drop: | |
51 | kfree_skb(skb); | |
52 | return NET_RX_DROP; | |
53 | } | |
54 | #endif | |
55 | ||
1da177e4 LT |
56 | int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type) |
57 | { | |
6067b2ba | 58 | __be32 spi, seq; |
dbe5b4aa | 59 | struct xfrm_state *xfrm_vec[XFRM_MAX_DEPTH]; |
1da177e4 LT |
60 | struct xfrm_state *x; |
61 | int xfrm_nr = 0; | |
62 | int decaps = 0; | |
eddc9ec5 | 63 | int err = xfrm4_parse_spi(skb, ip_hdr(skb)->protocol, &spi, &seq); |
1da177e4 | 64 | |
eddc9ec5 | 65 | if (err != 0) |
1da177e4 LT |
66 | goto drop; |
67 | ||
68 | do { | |
eddc9ec5 | 69 | const struct iphdr *iph = ip_hdr(skb); |
1da177e4 LT |
70 | |
71 | if (xfrm_nr == XFRM_MAX_DEPTH) | |
72 | goto drop; | |
73 | ||
c0d56408 KM |
74 | x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, |
75 | iph->protocol != IPPROTO_IPV6 ? iph->protocol : IPPROTO_IPIP, AF_INET); | |
1da177e4 LT |
76 | if (x == NULL) |
77 | goto drop; | |
78 | ||
79 | spin_lock(&x->lock); | |
80 | if (unlikely(x->km.state != XFRM_STATE_VALID)) | |
81 | goto drop_unlock; | |
82 | ||
8bf4b8a1 | 83 | if ((x->encap ? x->encap->encap_type : 0) != encap_type) |
e695633e HX |
84 | goto drop_unlock; |
85 | ||
1da177e4 LT |
86 | if (x->props.replay_window && xfrm_replay_check(x, seq)) |
87 | goto drop_unlock; | |
88 | ||
89 | if (xfrm_state_check_expire(x)) | |
90 | goto drop_unlock; | |
91 | ||
e695633e | 92 | if (x->type->input(x, skb)) |
1da177e4 LT |
93 | goto drop_unlock; |
94 | ||
95 | /* only the first xfrm gets the encap type */ | |
96 | encap_type = 0; | |
97 | ||
98 | if (x->props.replay_window) | |
99 | xfrm_replay_advance(x, seq); | |
100 | ||
101 | x->curlft.bytes += skb->len; | |
102 | x->curlft.packets++; | |
103 | ||
104 | spin_unlock(&x->lock); | |
105 | ||
dbe5b4aa | 106 | xfrm_vec[xfrm_nr++] = x; |
1da177e4 | 107 | |
b59f45d0 HX |
108 | if (x->mode->input(x, skb)) |
109 | goto drop; | |
1da177e4 | 110 | |
7e49e6de | 111 | if (x->props.mode == XFRM_MODE_TUNNEL) { |
1da177e4 LT |
112 | decaps = 1; |
113 | break; | |
114 | } | |
115 | ||
eddc9ec5 ACM |
116 | err = xfrm_parse_spi(skb, ip_hdr(skb)->protocol, &spi, &seq); |
117 | if (err < 0) | |
1da177e4 LT |
118 | goto drop; |
119 | } while (!err); | |
120 | ||
121 | /* Allocate new secpath or COW existing one. */ | |
122 | ||
123 | if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) { | |
124 | struct sec_path *sp; | |
125 | sp = secpath_dup(skb->sp); | |
126 | if (!sp) | |
127 | goto drop; | |
128 | if (skb->sp) | |
129 | secpath_put(skb->sp); | |
130 | skb->sp = sp; | |
131 | } | |
132 | if (xfrm_nr + skb->sp->len > XFRM_MAX_DEPTH) | |
133 | goto drop; | |
134 | ||
dbe5b4aa HX |
135 | memcpy(skb->sp->xvec + skb->sp->len, xfrm_vec, |
136 | xfrm_nr * sizeof(xfrm_vec[0])); | |
1da177e4 LT |
137 | skb->sp->len += xfrm_nr; |
138 | ||
b05e1066 PM |
139 | nf_reset(skb); |
140 | ||
1da177e4 | 141 | if (decaps) { |
f282d45c KM |
142 | dst_release(skb->dst); |
143 | skb->dst = NULL; | |
1da177e4 LT |
144 | netif_rx(skb); |
145 | return 0; | |
146 | } else { | |
b05e1066 | 147 | #ifdef CONFIG_NETFILTER |
d56f90a7 | 148 | __skb_push(skb, skb->data - skb_network_header(skb)); |
eddc9ec5 ACM |
149 | ip_hdr(skb)->tot_len = htons(skb->len); |
150 | ip_send_check(ip_hdr(skb)); | |
b05e1066 PM |
151 | |
152 | NF_HOOK(PF_INET, NF_IP_PRE_ROUTING, skb, skb->dev, NULL, | |
e905a9ed | 153 | xfrm4_rcv_encap_finish); |
b05e1066 PM |
154 | return 0; |
155 | #else | |
eddc9ec5 | 156 | return -ip_hdr(skb)->protocol; |
b05e1066 | 157 | #endif |
1da177e4 LT |
158 | } |
159 | ||
160 | drop_unlock: | |
161 | spin_unlock(&x->lock); | |
162 | xfrm_state_put(x); | |
163 | drop: | |
164 | while (--xfrm_nr >= 0) | |
dbe5b4aa | 165 | xfrm_state_put(xfrm_vec[xfrm_nr]); |
1da177e4 LT |
166 | |
167 | kfree_skb(skb); | |
168 | return 0; | |
169 | } |