net/ipv6/xfrm6_input.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * xfrm6_input.c: based on net/ipv4/xfrm4_input.c
   4  *
   5  * Authors:
   6  *      Mitsuru KANDA @USAGI
   7  *      Kazunori MIYAZAWA @USAGI
   8  *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
   9  *      YOSHIFUJI Hideaki @USAGI
  10  *              IPv6 support
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/string.h>
  15 #include <linux/netfilter.h>
  16 #include <linux/netfilter_ipv6.h>
  17 #include <net/ipv6.h>
  18 #include <net/xfrm.h>
  19
  20 int xfrm6_extract_input(struct xfrm_state *x, struct sk_buff *skb)
  21 {
  22         return xfrm6_extract_header(skb);
  23 }
  24
  25 int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi,
  26                   struct ip6_tnl *t)
  27 {
  28         XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
  29         XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
  30         XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
  31         return xfrm_input(skb, nexthdr, spi, 0);
  32 }
  33 EXPORT_SYMBOL(xfrm6_rcv_spi);
  34
  35 int xfrm6_transport_finish(struct sk_buff *skb, int async)
  36 {
  37         struct xfrm_offload *xo = xfrm_offload(skb);
  38         int nhlen = skb->data - skb_network_header(skb);
  39
  40         skb_network_header(skb)[IP6CB(skb)->nhoff] =
  41                 XFRM_MODE_SKB_CB(skb)->protocol;
  42
  43 #ifndef CONFIG_NETFILTER
  44         if (!async)
  45                 return 1;
  46 #endif
  47
  48         __skb_push(skb, nhlen);
  49         ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
  50         skb_postpush_rcsum(skb, skb_network_header(skb), nhlen);
  51
  52         if (xo && (xo->flags & XFRM_GRO)) {
  53                 skb_mac_header_rebuild(skb);
  54                 return -1;
  55         }
  56
  57         NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
  58                 dev_net(skb->dev), NULL, skb, skb->dev, NULL,
  59                 ip6_rcv_finish);
  60         return -1;
  61 }
  62
  63 int xfrm6_rcv_tnl(struct sk_buff *skb, struct ip6_tnl *t)
  64 {
  65         return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
  66                              0, t);
  67 }
  68 EXPORT_SYMBOL(xfrm6_rcv_tnl);
  69
  70 int xfrm6_rcv(struct sk_buff *skb)
  71 {
  72         return xfrm6_rcv_tnl(skb, NULL);
  73 }
  74 EXPORT_SYMBOL(xfrm6_rcv);
  75 int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
  76                      xfrm_address_t *saddr, u8 proto)
  77 {
  78         struct net *net = dev_net(skb->dev);
  79         struct xfrm_state *x = NULL;
  80         int i = 0;
  81
  82         if (secpath_set(skb)) {
  83                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
  84                 goto drop;
  85         }
  86
  87         if (1 + skb->sp->len == XFRM_MAX_DEPTH) {
  88                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
  89                 goto drop;
  90         }
  91
  92         for (i = 0; i < 3; i++) {
  93                 xfrm_address_t *dst, *src;
  94
  95                 switch (i) {
  96                 case 0:
  97                         dst = daddr;
  98                         src = saddr;
  99                         break;
 100                 case 1:
 101                         /* lookup state with wild-card source address */
 102                         dst = daddr;
 103                         src = (xfrm_address_t *)&in6addr_any;
 104                         break;
 105                 default:
 106                         /* lookup state with wild-card addresses */
 107                         dst = (xfrm_address_t *)&in6addr_any;
 108                         src = (xfrm_address_t *)&in6addr_any;
 109                         break;
 110                 }
 111
 112                 x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6);
 113                 if (!x)
 114                         continue;
 115
 116                 spin_lock(&x->lock);
 117
 118                 if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
 119                     likely(x->km.state == XFRM_STATE_VALID) &&
 120                     !xfrm_state_check_expire(x)) {
 121                         spin_unlock(&x->lock);
 122                         if (x->type->input(x, skb) > 0) {
 123                                 /* found a valid state */
 124                                 break;
 125                         }
 126                 } else
 127                         spin_unlock(&x->lock);
 128
 129                 xfrm_state_put(x);
 130                 x = NULL;
 131         }
 132
 133         if (!x) {
 134                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
 135                 xfrm_audit_state_notfound_simple(skb, AF_INET6);
 136                 goto drop;
 137         }
 138
 139         skb->sp->xvec[skb->sp->len++] = x;
 140
 141         spin_lock(&x->lock);
 142
 143         x->curlft.bytes += skb->len;
 144         x->curlft.packets++;
 145
 146         spin_unlock(&x->lock);
 147
 148         return 1;
 149
 150 drop:
 151         return -1;
 152 }
 153 EXPORT_SYMBOL(xfrm6_input_addr);