ipv6: When we droped a packet, we should return NET_RX_DROP instead of 0
[linux-2.6.git] / net / ipv6 / xfrm6_input.c
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>
14 #include <linux/netfilter.h>
15 #include <linux/netfilter_ipv6.h>
16 #include <net/ipv6.h>
17 #include <net/xfrm.h>
18
19 int xfrm6_extract_input(struct xfrm_state *x, struct sk_buff *skb)
20 {
21         return xfrm6_extract_header(skb);
22 }
23
24 int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi)
25 {
26         XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
27         XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
28         return xfrm_input(skb, nexthdr, spi, 0);
29 }
30 EXPORT_SYMBOL(xfrm6_rcv_spi);
31
32 int xfrm6_transport_finish(struct sk_buff *skb, int async)
33 {
34         skb_network_header(skb)[IP6CB(skb)->nhoff] =
35                 XFRM_MODE_SKB_CB(skb)->protocol;
36
37 #ifndef CONFIG_NETFILTER
38         if (!async)
39                 return 1;
40 #endif
41
42         ipv6_hdr(skb)->payload_len = htons(skb->len);
43         __skb_push(skb, skb->data - skb_network_header(skb));
44
45         NF_HOOK(PF_INET6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
46                 ip6_rcv_finish);
47         return -1;
48 }
49
50 int xfrm6_rcv(struct sk_buff *skb)
51 {
52         return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
53                              0);
54 }
55
56 EXPORT_SYMBOL(xfrm6_rcv);
57
58 int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
59                      xfrm_address_t *saddr, u8 proto)
60 {
61         struct xfrm_state *x = NULL;
62         int i = 0;
63
64         /* Allocate new secpath or COW existing one. */
65         if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
66                 struct sec_path *sp;
67
68                 sp = secpath_dup(skb->sp);
69                 if (!sp) {
70                         XFRM_INC_STATS(LINUX_MIB_XFRMINERROR);
71                         goto drop;
72                 }
73                 if (skb->sp)
74                         secpath_put(skb->sp);
75                 skb->sp = sp;
76         }
77
78         if (1 + skb->sp->len == XFRM_MAX_DEPTH) {
79                 XFRM_INC_STATS(LINUX_MIB_XFRMINBUFFERERROR);
80                 goto drop;
81         }
82
83         for (i = 0; i < 3; i++) {
84                 xfrm_address_t *dst, *src;
85
86                 switch (i) {
87                 case 0:
88                         dst = daddr;
89                         src = saddr;
90                         break;
91                 case 1:
92                         /* lookup state with wild-card source address */
93                         dst = daddr;
94                         src = (xfrm_address_t *)&in6addr_any;
95                         break;
96                 default:
97                         /* lookup state with wild-card addresses */
98                         dst = (xfrm_address_t *)&in6addr_any;
99                         src = (xfrm_address_t *)&in6addr_any;
100                         break;
101                 }
102
103                 x = xfrm_state_lookup_byaddr(dst, src, proto, AF_INET6);
104                 if (!x)
105                         continue;
106
107                 spin_lock(&x->lock);
108
109                 if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
110                     likely(x->km.state == XFRM_STATE_VALID) &&
111                     !xfrm_state_check_expire(x)) {
112                         spin_unlock(&x->lock);
113                         if (x->type->input(x, skb) > 0) {
114                                 /* found a valid state */
115                                 break;
116                         }
117                 } else
118                         spin_unlock(&x->lock);
119
120                 xfrm_state_put(x);
121                 x = NULL;
122         }
123
124         if (!x) {
125                 XFRM_INC_STATS(LINUX_MIB_XFRMINNOSTATES);
126                 xfrm_audit_state_notfound_simple(skb, AF_INET6);
127                 goto drop;
128         }
129
130         skb->sp->xvec[skb->sp->len++] = x;
131
132         spin_lock(&x->lock);
133
134         x->curlft.bytes += skb->len;
135         x->curlft.packets++;
136
137         spin_unlock(&x->lock);
138
139         return 1;
140
141 drop:
142         return -1;
143 }
144
145 EXPORT_SYMBOL(xfrm6_input_addr);