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)->nhoff = IP6CB(skb)->nhoff;
  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 #ifdef CONFIG_NETFILTER
  35         ipv6_hdr(skb)->payload_len = htons(skb->len);
  36         __skb_push(skb, skb->data - skb_network_header(skb));
  37
  38         NF_HOOK(PF_INET6, NF_IP6_PRE_ROUTING, skb, skb->dev, NULL,
  39                 ip6_rcv_finish);
  40         return -1;
  41 #else
  42         return 1;
  43 #endif
  44 }
  45
  46 int xfrm6_rcv(struct sk_buff *skb)
  47 {
  48         return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
  49                              0);
  50 }
  51
  52 EXPORT_SYMBOL(xfrm6_rcv);
  53
  54 int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
  55                      xfrm_address_t *saddr, u8 proto)
  56 {
  57         struct xfrm_state *x = NULL;
  58         int wildcard = 0;
  59         xfrm_address_t *xany;
  60         struct xfrm_state *xfrm_vec_one = NULL;
  61         int nh = 0;
  62         int i = 0;
  63
  64         xany = (xfrm_address_t *)&in6addr_any;
  65
  66         for (i = 0; i < 3; i++) {
  67                 xfrm_address_t *dst, *src;
  68                 switch (i) {
  69                 case 0:
  70                         dst = daddr;
  71                         src = saddr;
  72                         break;
  73                 case 1:
  74                         /* lookup state with wild-card source address */
  75                         wildcard = 1;
  76                         dst = daddr;
  77                         src = xany;
  78                         break;
  79                 case 2:
  80                 default:
  81                         /* lookup state with wild-card addresses */
  82                         wildcard = 1; /* XXX */
  83                         dst = xany;
  84                         src = xany;
  85                         break;
  86                 }
  87
  88                 x = xfrm_state_lookup_byaddr(dst, src, proto, AF_INET6);
  89                 if (!x)
  90                         continue;
  91
  92                 spin_lock(&x->lock);
  93
  94                 if (wildcard) {
  95                         if ((x->props.flags & XFRM_STATE_WILDRECV) == 0) {
  96                                 spin_unlock(&x->lock);
  97                                 xfrm_state_put(x);
  98                                 x = NULL;
  99                                 continue;
 100                         }
 101                 }
 102
 103                 if (unlikely(x->km.state != XFRM_STATE_VALID)) {
 104                         spin_unlock(&x->lock);
 105                         xfrm_state_put(x);
 106                         x = NULL;
 107                         continue;
 108                 }
 109                 if (xfrm_state_check_expire(x)) {
 110                         spin_unlock(&x->lock);
 111                         xfrm_state_put(x);
 112                         x = NULL;
 113                         continue;
 114                 }
 115
 116                 nh = x->type->input(x, skb);
 117                 if (nh <= 0) {
 118                         spin_unlock(&x->lock);
 119                         xfrm_state_put(x);
 120                         x = NULL;
 121                         continue;
 122                 }
 123
 124                 x->curlft.bytes += skb->len;
 125                 x->curlft.packets++;
 126
 127                 spin_unlock(&x->lock);
 128
 129                 xfrm_vec_one = x;
 130                 break;
 131         }
 132
 133         if (!xfrm_vec_one)
 134                 goto drop;
 135
 136         /* Allocate new secpath or COW existing one. */
 137         if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
 138                 struct sec_path *sp;
 139                 sp = secpath_dup(skb->sp);
 140                 if (!sp)
 141                         goto drop;
 142                 if (skb->sp)
 143                         secpath_put(skb->sp);
 144                 skb->sp = sp;
 145         }
 146
 147         if (1 + skb->sp->len > XFRM_MAX_DEPTH)
 148                 goto drop;
 149
 150         skb->sp->xvec[skb->sp->len] = xfrm_vec_one;
 151         skb->sp->len ++;
 152
 153         return 1;
 154 drop:
 155         if (xfrm_vec_one)
 156                 xfrm_state_put(xfrm_vec_one);
 157         return -1;
 158 }
 159
 160 EXPORT_SYMBOL(xfrm6_input_addr);