blob: 28c29d78338e3a84c259264182b6f5d322f71ac9 [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>
14#include <net/dsfield.h>
15#include <net/inet_ecn.h>
16#include <net/ip.h>
17#include <net/ipv6.h>
18#include <net/xfrm.h>
19
20static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
21{
22 struct ipv6hdr *outer_iph = skb->nh.ipv6h;
23 struct ipv6hdr *inner_iph = skb->h.ipv6h;
24
25 if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
26 IP6_ECN_set_ce(inner_iph);
27}
28
29int xfrm6_rcv_spi(struct sk_buff **pskb, unsigned int *nhoffp, u32 spi)
30{
31 struct sk_buff *skb = *pskb;
32 int err;
33 u32 seq;
34 struct sec_decap_state xfrm_vec[XFRM_MAX_DEPTH];
35 struct xfrm_state *x;
36 int xfrm_nr = 0;
37 int decaps = 0;
38 int nexthdr;
39 unsigned int nhoff;
40
41 nhoff = *nhoffp;
42 nexthdr = skb->nh.raw[nhoff];
43
44 seq = 0;
45 if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0)
46 goto drop;
47
48 do {
49 struct ipv6hdr *iph = skb->nh.ipv6h;
50
51 if (xfrm_nr == XFRM_MAX_DEPTH)
52 goto drop;
53
54 x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, nexthdr, AF_INET6);
55 if (x == NULL)
56 goto drop;
57 spin_lock(&x->lock);
58 if (unlikely(x->km.state != XFRM_STATE_VALID))
59 goto drop_unlock;
60
61 if (x->props.replay_window && xfrm_replay_check(x, seq))
62 goto drop_unlock;
63
64 if (xfrm_state_check_expire(x))
65 goto drop_unlock;
66
67 nexthdr = x->type->input(x, &(xfrm_vec[xfrm_nr].decap), skb);
68 if (nexthdr <= 0)
69 goto drop_unlock;
70
71 skb->nh.raw[nhoff] = nexthdr;
72
73 if (x->props.replay_window)
74 xfrm_replay_advance(x, seq);
75
76 x->curlft.bytes += skb->len;
77 x->curlft.packets++;
78
79 spin_unlock(&x->lock);
80
81 xfrm_vec[xfrm_nr++].xvec = x;
82
83 if (x->props.mode) { /* XXX */
84 if (nexthdr != IPPROTO_IPV6)
85 goto drop;
86 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
87 goto drop;
88 if (skb_cloned(skb) &&
89 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
90 goto drop;
91 if (x->props.flags & XFRM_STATE_DECAP_DSCP)
92 ipv6_copy_dscp(skb->nh.ipv6h, skb->h.ipv6h);
93 if (!(x->props.flags & XFRM_STATE_NOECN))
94 ipip6_ecn_decapsulate(skb);
95 skb->mac.raw = memmove(skb->data - skb->mac_len,
96 skb->mac.raw, skb->mac_len);
97 skb->nh.raw = skb->data;
98 decaps = 1;
99 break;
100 }
101
102 if ((err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) < 0)
103 goto drop;
104 } while (!err);
105
106 /* Allocate new secpath or COW existing one. */
107 if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
108 struct sec_path *sp;
109 sp = secpath_dup(skb->sp);
110 if (!sp)
111 goto drop;
112 if (skb->sp)
113 secpath_put(skb->sp);
114 skb->sp = sp;
115 }
116
117 if (xfrm_nr + skb->sp->len > XFRM_MAX_DEPTH)
118 goto drop;
119
120 memcpy(skb->sp->x+skb->sp->len, xfrm_vec, xfrm_nr*sizeof(struct sec_decap_state));
121 skb->sp->len += xfrm_nr;
122 skb->ip_summed = CHECKSUM_NONE;
123
124 if (decaps) {
125 if (!(skb->dev->flags&IFF_LOOPBACK)) {
126 dst_release(skb->dst);
127 skb->dst = NULL;
128 }
129 netif_rx(skb);
130 return -1;
131 } else {
132 return 1;
133 }
134
135drop_unlock:
136 spin_unlock(&x->lock);
137 xfrm_state_put(x);
138drop:
139 while (--xfrm_nr >= 0)
140 xfrm_state_put(xfrm_vec[xfrm_nr].xvec);
141 kfree_skb(skb);
142 return -1;
143}
144
145EXPORT_SYMBOL(xfrm6_rcv_spi);
146
147int xfrm6_rcv(struct sk_buff **pskb, unsigned int *nhoffp)
148{
149 return xfrm6_rcv_spi(pskb, nhoffp, 0);
150}