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 static int xfrm6_transport_finish2(struct net *net, struct sock *sk,
  36                                    struct sk_buff *skb)
  37 {
  38         if (xfrm_trans_queue(skb, ip6_rcv_finish))
  39                 __kfree_skb(skb);
  40         return -1;
  41 }
  42
  43 int xfrm6_transport_finish(struct sk_buff *skb, int async)
  44 {
  45         struct xfrm_offload *xo = xfrm_offload(skb);
  46         int nhlen = skb->data - skb_network_header(skb);
  47
  48         skb_network_header(skb)[IP6CB(skb)->nhoff] =
  49                 XFRM_MODE_SKB_CB(skb)->protocol;
  50
  51 #ifndef CONFIG_NETFILTER
  52         if (!async)
  53                 return 1;
  54 #endif
  55
  56         __skb_push(skb, nhlen);
  57         ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
  58         skb_postpush_rcsum(skb, skb_network_header(skb), nhlen);
  59
  60         if (xo && (xo->flags & XFRM_GRO)) {
  61                 skb_mac_header_rebuild(skb);
  62                 skb_reset_transport_header(skb);
  63                 return -1;
  64         }
  65
  66         NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
  67                 dev_net(skb->dev), NULL, skb, skb->dev, NULL,
  68                 xfrm6_transport_finish2);
  69         return -1;
  70 }
  71
  72 int xfrm6_rcv_tnl(struct sk_buff *skb, struct ip6_tnl *t)
  73 {
  74         return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
  75                              0, t);
  76 }
  77 EXPORT_SYMBOL(xfrm6_rcv_tnl);
  78
  79 int xfrm6_rcv(struct sk_buff *skb)
  80 {
  81         return xfrm6_rcv_tnl(skb, NULL);
  82 }
  83 EXPORT_SYMBOL(xfrm6_rcv);
  84 int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
  85                      xfrm_address_t *saddr, u8 proto)
  86 {
  87         struct net *net = dev_net(skb->dev);
  88         struct xfrm_state *x = NULL;
  89         struct sec_path *sp;
  90         int i = 0;
  91
  92         sp = secpath_set(skb);
  93         if (!sp) {
  94                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
  95                 goto drop;
  96         }
  97
  98         if (1 + sp->len == XFRM_MAX_DEPTH) {
  99                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
 100                 goto drop;
 101         }
 102
 103         for (i = 0; i < 3; i++) {
 104                 xfrm_address_t *dst, *src;
 105
 106                 switch (i) {
 107                 case 0:
 108                         dst = daddr;
 109                         src = saddr;
 110                         break;
 111                 case 1:
 112                         /* lookup state with wild-card source address */
 113                         dst = daddr;
 114                         src = (xfrm_address_t *)&in6addr_any;
 115                         break;
 116                 default:
 117                         /* lookup state with wild-card addresses */
 118                         dst = (xfrm_address_t *)&in6addr_any;
 119                         src = (xfrm_address_t *)&in6addr_any;
 120                         break;
 121                 }
 122
 123                 x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6);
 124                 if (!x)
 125                         continue;
 126
 127                 spin_lock(&x->lock);
 128
 129                 if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
 130                     likely(x->km.state == XFRM_STATE_VALID) &&
 131                     !xfrm_state_check_expire(x)) {
 132                         spin_unlock(&x->lock);
 133                         if (x->type->input(x, skb) > 0) {
 134                                 /* found a valid state */
 135                                 break;
 136                         }
 137                 } else
 138                         spin_unlock(&x->lock);
 139
 140                 xfrm_state_put(x);
 141                 x = NULL;
 142         }
 143
 144         if (!x) {
 145                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
 146                 xfrm_audit_state_notfound_simple(skb, AF_INET6);
 147                 goto drop;
 148         }
 149
 150         sp->xvec[sp->len++] = x;
 151
 152         spin_lock(&x->lock);
 153
 154         x->curlft.bytes += skb->len;
 155         x->curlft.packets++;
 156
 157         spin_unlock(&x->lock);
 158
 159         return 1;
 160
 161 drop:
 162         return -1;
 163 }
 164 EXPORT_SYMBOL(xfrm6_input_addr);