blob: 1ca2da68ef69c35e420c1badf3c84e079bb88aec [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Patrick McHardyb05e1062006-01-06 23:03:34 -080014#include <linux/netfilter.h>
15#include <linux/netfilter_ipv6.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#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
22static 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
Patrick McHardy951dbc82006-01-06 23:02:34 -080031int xfrm6_rcv_spi(struct sk_buff **pskb, u32 spi)
Linus Torvalds1da177e2005-04-16 15:20:36 -070032{
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
Patrick McHardy951dbc82006-01-06 23:02:34 -080043 nhoff = IP6CB(skb)->nhoff;
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 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
Patrick McHardyb05e1062006-01-06 23:03:34 -0800126 nf_reset(skb);
127
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 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 {
Patrick McHardyb05e1062006-01-06 23:03:34 -0800136#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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 return 1;
Patrick McHardyb05e1062006-01-06 23:03:34 -0800145#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 }
147
148drop_unlock:
149 spin_unlock(&x->lock);
150 xfrm_state_put(x);
151drop:
152 while (--xfrm_nr >= 0)
153 xfrm_state_put(xfrm_vec[xfrm_nr].xvec);
154 kfree_skb(skb);
155 return -1;
156}
157
158EXPORT_SYMBOL(xfrm6_rcv_spi);
159
Patrick McHardy951dbc82006-01-06 23:02:34 -0800160int xfrm6_rcv(struct sk_buff **pskb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161{
Patrick McHardy951dbc82006-01-06 23:02:34 -0800162 return xfrm6_rcv_spi(pskb, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163}