net/ipv6/xfrm6_state.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * xfrm6_state.c: based on xfrm4_state.c
   4  *
   5  * Authors:
   6  *      Mitsuru KANDA @USAGI
   7  *      Kazunori MIYAZAWA @USAGI
   8  *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
   9  *              IPv6 support
  10  *      YOSHIFUJI Hideaki @USAGI
  11  *              Split up af-specific portion
  12  *
  13  */
  14
  15 #include <net/xfrm.h>
  16 #include <linux/pfkeyv2.h>
  17 #include <linux/ipsec.h>
  18 #include <linux/netfilter_ipv6.h>
  19 #include <linux/export.h>
  20 #include <net/dsfield.h>
  21 #include <net/ipv6.h>
  22 #include <net/addrconf.h>
  23
  24 static void
  25 __xfrm6_init_tempsel(struct xfrm_selector *sel, const struct flowi *fl)
  26 {
  27         const struct flowi6 *fl6 = &fl->u.ip6;
  28
  29         /* Initialize temporary selector matching only
  30          * to current session. */
  31         *(struct in6_addr *)&sel->daddr = fl6->daddr;
  32         *(struct in6_addr *)&sel->saddr = fl6->saddr;
  33         sel->dport = xfrm_flowi_dport(fl, &fl6->uli);
  34         sel->dport_mask = htons(0xffff);
  35         sel->sport = xfrm_flowi_sport(fl, &fl6->uli);
  36         sel->sport_mask = htons(0xffff);
  37         sel->family = AF_INET6;
  38         sel->prefixlen_d = 128;
  39         sel->prefixlen_s = 128;
  40         sel->proto = fl6->flowi6_proto;
  41         sel->ifindex = fl6->flowi6_oif;
  42 }
  43
  44 static void
  45 xfrm6_init_temprop(struct xfrm_state *x, const struct xfrm_tmpl *tmpl,
  46                    const xfrm_address_t *daddr, const xfrm_address_t *saddr)
  47 {
  48         x->id = tmpl->id;
  49         if (ipv6_addr_any((struct in6_addr *)&x->id.daddr))
  50                 memcpy(&x->id.daddr, daddr, sizeof(x->sel.daddr));
  51         memcpy(&x->props.saddr, &tmpl->saddr, sizeof(x->props.saddr));
  52         if (ipv6_addr_any((struct in6_addr *)&x->props.saddr))
  53                 memcpy(&x->props.saddr, saddr, sizeof(x->props.saddr));
  54         x->props.mode = tmpl->mode;
  55         x->props.reqid = tmpl->reqid;
  56         x->props.family = AF_INET6;
  57 }
  58
  59 /* distribution counting sort function for xfrm_state and xfrm_tmpl */
  60 static int
  61 __xfrm6_sort(void **dst, void **src, int n, int (*cmp)(void *p), int maxclass)
  62 {
  63         int count[XFRM_MAX_DEPTH] = { };
  64         int class[XFRM_MAX_DEPTH];
  65         int i;
  66
  67         for (i = 0; i < n; i++) {
  68                 int c;
  69                 class[i] = c = cmp(src[i]);
  70                 count[c]++;
  71         }
  72
  73         for (i = 2; i < maxclass; i++)
  74                 count[i] += count[i - 1];
  75
  76         for (i = 0; i < n; i++) {
  77                 dst[count[class[i] - 1]++] = src[i];
  78                 src[i] = NULL;
  79         }
  80
  81         return 0;
  82 }
  83
  84 /*
  85  * Rule for xfrm_state:
  86  *
  87  * rule 1: select IPsec transport except AH
  88  * rule 2: select MIPv6 RO or inbound trigger
  89  * rule 3: select IPsec transport AH
  90  * rule 4: select IPsec tunnel
  91  * rule 5: others
  92  */
  93 static int __xfrm6_state_sort_cmp(void *p)
  94 {
  95         struct xfrm_state *v = p;
  96
  97         switch (v->props.mode) {
  98         case XFRM_MODE_TRANSPORT:
  99                 if (v->id.proto != IPPROTO_AH)
 100                         return 1;
 101                 else
 102                         return 3;
 103 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 104         case XFRM_MODE_ROUTEOPTIMIZATION:
 105         case XFRM_MODE_IN_TRIGGER:
 106                 return 2;
 107 #endif
 108         case XFRM_MODE_TUNNEL:
 109         case XFRM_MODE_BEET:
 110                 return 4;
 111         }
 112         return 5;
 113 }
 114
 115 static int
 116 __xfrm6_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n)
 117 {
 118         return __xfrm6_sort((void **)dst, (void **)src, n,
 119                             __xfrm6_state_sort_cmp, 6);
 120 }
 121
 122 /*
 123  * Rule for xfrm_tmpl:
 124  *
 125  * rule 1: select IPsec transport
 126  * rule 2: select MIPv6 RO or inbound trigger
 127  * rule 3: select IPsec tunnel
 128  * rule 4: others
 129  */
 130 static int __xfrm6_tmpl_sort_cmp(void *p)
 131 {
 132         struct xfrm_tmpl *v = p;
 133         switch (v->mode) {
 134         case XFRM_MODE_TRANSPORT:
 135                 return 1;
 136 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 137         case XFRM_MODE_ROUTEOPTIMIZATION:
 138         case XFRM_MODE_IN_TRIGGER:
 139                 return 2;
 140 #endif
 141         case XFRM_MODE_TUNNEL:
 142         case XFRM_MODE_BEET:
 143                 return 3;
 144         }
 145         return 4;
 146 }
 147
 148 static int
 149 __xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)
 150 {
 151         return __xfrm6_sort((void **)dst, (void **)src, n,
 152                             __xfrm6_tmpl_sort_cmp, 5);
 153 }
 154
 155 int xfrm6_extract_header(struct sk_buff *skb)
 156 {
 157         struct ipv6hdr *iph = ipv6_hdr(skb);
 158
 159         XFRM_MODE_SKB_CB(skb)->ihl = sizeof(*iph);
 160         XFRM_MODE_SKB_CB(skb)->id = 0;
 161         XFRM_MODE_SKB_CB(skb)->frag_off = htons(IP_DF);
 162         XFRM_MODE_SKB_CB(skb)->tos = ipv6_get_dsfield(iph);
 163         XFRM_MODE_SKB_CB(skb)->ttl = iph->hop_limit;
 164         XFRM_MODE_SKB_CB(skb)->optlen = 0;
 165         memcpy(XFRM_MODE_SKB_CB(skb)->flow_lbl, iph->flow_lbl,
 166                sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
 167
 168         return 0;
 169 }
 170
 171 static struct xfrm_state_afinfo xfrm6_state_afinfo = {
 172         .family                 = AF_INET6,
 173         .proto                  = IPPROTO_IPV6,
 174         .eth_proto              = htons(ETH_P_IPV6),
 175         .owner                  = THIS_MODULE,
 176         .init_tempsel           = __xfrm6_init_tempsel,
 177         .init_temprop           = xfrm6_init_temprop,
 178         .tmpl_sort              = __xfrm6_tmpl_sort,
 179         .state_sort             = __xfrm6_state_sort,
 180         .output                 = xfrm6_output,
 181         .output_finish          = xfrm6_output_finish,
 182         .extract_input          = xfrm6_extract_input,
 183         .extract_output         = xfrm6_extract_output,
 184         .transport_finish       = xfrm6_transport_finish,
 185         .local_error            = xfrm6_local_error,
 186 };
 187
 188 int __init xfrm6_state_init(void)
 189 {
 190         return xfrm_state_register_afinfo(&xfrm6_state_afinfo);
 191 }
 192
 193 void xfrm6_state_fini(void)
 194 {
 195         xfrm_state_unregister_afinfo(&xfrm6_state_afinfo);
 196 }