net/ipv4/xfrm4_state.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * xfrm4_state.c
   4  *
   5  * Changes:
   6  *      YOSHIFUJI Hideaki @USAGI
   7  *              Split up af-specific portion
   8  *
   9  */
  10
  11 #include <net/ip.h>
  12 #include <net/xfrm.h>
  13 #include <linux/pfkeyv2.h>
  14 #include <linux/ipsec.h>
  15 #include <linux/netfilter_ipv4.h>
  16 #include <linux/export.h>
  17
  18 static int xfrm4_init_flags(struct xfrm_state *x)
  19 {
  20         if (xs_net(x)->ipv4.sysctl_ip_no_pmtu_disc)
  21                 x->props.flags |= XFRM_STATE_NOPMTUDISC;
  22         return 0;
  23 }
  24
  25 static void
  26 __xfrm4_init_tempsel(struct xfrm_selector *sel, const struct flowi *fl)
  27 {
  28         const struct flowi4 *fl4 = &fl->u.ip4;
  29
  30         sel->daddr.a4 = fl4->daddr;
  31         sel->saddr.a4 = fl4->saddr;
  32         sel->dport = xfrm_flowi_dport(fl, &fl4->uli);
  33         sel->dport_mask = htons(0xffff);
  34         sel->sport = xfrm_flowi_sport(fl, &fl4->uli);
  35         sel->sport_mask = htons(0xffff);
  36         sel->family = AF_INET;
  37         sel->prefixlen_d = 32;
  38         sel->prefixlen_s = 32;
  39         sel->proto = fl4->flowi4_proto;
  40         sel->ifindex = fl4->flowi4_oif;
  41 }
  42
  43 static void
  44 xfrm4_init_temprop(struct xfrm_state *x, const struct xfrm_tmpl *tmpl,
  45                    const xfrm_address_t *daddr, const xfrm_address_t *saddr)
  46 {
  47         x->id = tmpl->id;
  48         if (x->id.daddr.a4 == 0)
  49                 x->id.daddr.a4 = daddr->a4;
  50         x->props.saddr = tmpl->saddr;
  51         if (x->props.saddr.a4 == 0)
  52                 x->props.saddr.a4 = saddr->a4;
  53         x->props.mode = tmpl->mode;
  54         x->props.reqid = tmpl->reqid;
  55         x->props.family = AF_INET;
  56 }
  57
  58 int xfrm4_extract_header(struct sk_buff *skb)
  59 {
  60         const struct iphdr *iph = ip_hdr(skb);
  61
  62         XFRM_MODE_SKB_CB(skb)->ihl = sizeof(*iph);
  63         XFRM_MODE_SKB_CB(skb)->id = iph->id;
  64         XFRM_MODE_SKB_CB(skb)->frag_off = iph->frag_off;
  65         XFRM_MODE_SKB_CB(skb)->tos = iph->tos;
  66         XFRM_MODE_SKB_CB(skb)->ttl = iph->ttl;
  67         XFRM_MODE_SKB_CB(skb)->optlen = iph->ihl * 4 - sizeof(*iph);
  68         memset(XFRM_MODE_SKB_CB(skb)->flow_lbl, 0,
  69                sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
  70
  71         return 0;
  72 }
  73
  74 static struct xfrm_state_afinfo xfrm4_state_afinfo = {
  75         .family                 = AF_INET,
  76         .proto                  = IPPROTO_IPIP,
  77         .eth_proto              = htons(ETH_P_IP),
  78         .owner                  = THIS_MODULE,
  79         .init_flags             = xfrm4_init_flags,
  80         .init_tempsel           = __xfrm4_init_tempsel,
  81         .init_temprop           = xfrm4_init_temprop,
  82         .output                 = xfrm4_output,
  83         .output_finish          = xfrm4_output_finish,
  84         .extract_input          = xfrm4_extract_input,
  85         .extract_output         = xfrm4_extract_output,
  86         .transport_finish       = xfrm4_transport_finish,
  87         .local_error            = xfrm4_local_error,
  88 };
  89
  90 void __init xfrm4_state_init(void)
  91 {
  92         xfrm_state_register_afinfo(&xfrm4_state_afinfo);
  93 }