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