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                   struct ip6_tnl *t)
  26 {
  27         XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
  28         XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
  29         XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
  30         return xfrm_input(skb, nexthdr, spi, 0);
  31 }
  32 EXPORT_SYMBOL(xfrm6_rcv_spi);
  33
  34 int xfrm6_transport_finish(struct sk_buff *skb, int async)
  35 {
  36         skb_network_header(skb)[IP6CB(skb)->nhoff] =
  37                 XFRM_MODE_SKB_CB(skb)->protocol;
  38
  39 #ifndef CONFIG_NETFILTER
  40         if (!async)
  41                 return 1;
  42 #endif
  43
  44         ipv6_hdr(skb)->payload_len = htons(skb->len);
  45         __skb_push(skb, skb->data - skb_network_header(skb));
  46
  47         NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
  48                 dev_net(skb->dev), NULL, skb, skb->dev, NULL,
  49                 ip6_rcv_finish);
  50         return -1;
  51 }
  52
  53 int xfrm6_rcv_tnl(struct sk_buff *skb, struct ip6_tnl *t)
  54 {
  55         return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
  56                              0, t);
  57 }
  58 EXPORT_SYMBOL(xfrm6_rcv_tnl);
  59
  60 int xfrm6_rcv(struct sk_buff *skb)
  61 {
  62         return xfrm6_rcv_tnl(skb, NULL);
  63 }
  64 EXPORT_SYMBOL(xfrm6_rcv);
  65 int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
  66                      xfrm_address_t *saddr, u8 proto)
  67 {
  68         struct net *net = dev_net(skb->dev);
  69         struct xfrm_state *x = NULL;
  70         int i = 0;
  71
  72         /* Allocate new secpath or COW existing one. */
  73         if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
  74                 struct sec_path *sp;
  75
  76                 sp = secpath_dup(skb->sp);
  77                 if (!sp) {
  78                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
  79                         goto drop;
  80                 }
  81                 if (skb->sp)
  82                         secpath_put(skb->sp);
  83                 skb->sp = sp;
  84         }
  85
  86         if (1 + skb->sp->len == XFRM_MAX_DEPTH) {
  87                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
  88                 goto drop;
  89         }
  90
  91         for (i = 0; i < 3; i++) {
  92                 xfrm_address_t *dst, *src;
  93
  94                 switch (i) {
  95                 case 0:
  96                         dst = daddr;
  97                         src = saddr;
  98                         break;
  99                 case 1:
 100                         /* lookup state with wild-card source address */
 101                         dst = daddr;
 102                         src = (xfrm_address_t *)&in6addr_any;
 103                         break;
 104                 default:
 105                         /* lookup state with wild-card addresses */
 106                         dst = (xfrm_address_t *)&in6addr_any;
 107                         src = (xfrm_address_t *)&in6addr_any;
 108                         break;
 109                 }
 110
 111                 x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6);
 112                 if (!x)
 113                         continue;
 114
 115                 spin_lock(&x->lock);
 116
 117                 if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
 118                     likely(x->km.state == XFRM_STATE_VALID) &&
 119                     !xfrm_state_check_expire(x)) {
 120                         spin_unlock(&x->lock);
 121                         if (x->type->input(x, skb) > 0) {
 122                                 /* found a valid state */
 123                                 break;
 124                         }
 125                 } else
 126                         spin_unlock(&x->lock);
 127
 128                 xfrm_state_put(x);
 129                 x = NULL;
 130         }
 131
 132         if (!x) {
 133                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
 134                 xfrm_audit_state_notfound_simple(skb, AF_INET6);
 135                 goto drop;
 136         }
 137
 138         skb->sp->xvec[skb->sp->len++] = x;
 139
 140         spin_lock(&x->lock);
 141
 142         x->curlft.bytes += skb->len;
 143         x->curlft.packets++;
 144
 145         spin_unlock(&x->lock);
 146
 147         return 1;
 148
 149 drop:
 150         return -1;
 151 }
 152 EXPORT_SYMBOL(xfrm6_input_addr);