net/ipv6/xfrm6_state.c

   1 /*
   2  * xfrm6_state.c: based on xfrm4_state.c
   3  *
   4  * Authors:
   5  *      Mitsuru KANDA @USAGI
   6  *      Kazunori MIYAZAWA @USAGI
   7  *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
   8  *              IPv6 support
   9  *      YOSHIFUJI Hideaki @USAGI
  10  *              Split up af-specific portion
  11  *
  12  */
  13
  14 #include <net/xfrm.h>
  15 #include <linux/pfkeyv2.h>
  16 #include <linux/ipsec.h>
  17 #include <linux/netfilter_ipv6.h>
  18 #include <linux/export.h>
  19 #include <net/dsfield.h>
  20 #include <net/ipv6.h>
  21 #include <net/addrconf.h>
  22
  23 static void
  24 __xfrm6_init_tempsel(struct xfrm_selector *sel, const struct flowi *fl)
  25 {
  26         const struct flowi6 *fl6 = &fl->u.ip6;
  27
  28         /* Initialize temporary selector matching only
  29          * to current session. */
  30         *(struct in6_addr *)&sel->daddr = fl6->daddr;
  31         *(struct in6_addr *)&sel->saddr = fl6->saddr;
  32         sel->dport = xfrm_flowi_dport(fl, &fl6->uli);
  33         sel->dport_mask = htons(0xffff);
  34         sel->sport = xfrm_flowi_sport(fl, &fl6->uli);
  35         sel->sport_mask = htons(0xffff);
  36         sel->family = AF_INET6;
  37         sel->prefixlen_d = 128;
  38         sel->prefixlen_s = 128;
  39         sel->proto = fl6->flowi6_proto;
  40         sel->ifindex = fl6->flowi6_oif;
  41 }
  42
  43 static void
  44 xfrm6_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 (ipv6_addr_any((struct in6_addr*)&x->id.daddr))
  49                 memcpy(&x->id.daddr, daddr, sizeof(x->sel.daddr));
  50         memcpy(&x->props.saddr, &tmpl->saddr, sizeof(x->props.saddr));
  51         if (ipv6_addr_any((struct in6_addr*)&x->props.saddr))
  52                 memcpy(&x->props.saddr, saddr, sizeof(x->props.saddr));
  53         x->props.mode = tmpl->mode;
  54         x->props.reqid = tmpl->reqid;
  55         x->props.family = AF_INET6;
  56 }
  57
  58 /* distribution counting sort function for xfrm_state and xfrm_tmpl */
  59 static int
  60 __xfrm6_sort(void **dst, void **src, int n, int (*cmp)(void *p), int maxclass)
  61 {
  62         int i;
  63         int class[XFRM_MAX_DEPTH];
  64         int count[maxclass];
  65
  66         memset(count, 0, sizeof(count));
  67
  68         for (i = 0; i < n; i++) {
  69                 int c;
  70                 class[i] = c = cmp(src[i]);
  71                 count[c]++;
  72         }
  73
  74         for (i = 2; i < maxclass; i++)
  75                 count[i] += count[i - 1];
  76
  77         for (i = 0; i < n; i++) {
  78                 dst[count[class[i] - 1]++] = src[i];
  79                 src[i] = NULL;
  80         }
  81
  82         return 0;
  83 }
  84
  85 /*
  86  * Rule for xfrm_state:
  87  *
  88  * rule 1: select IPsec transport except AH
  89  * rule 2: select MIPv6 RO or inbound trigger
  90  * rule 3: select IPsec transport AH
  91  * rule 4: select IPsec tunnel
  92  * rule 5: others
  93  */
  94 static int __xfrm6_state_sort_cmp(void *p)
  95 {
  96         struct xfrm_state *v = p;
  97
  98         switch (v->props.mode) {
  99         case XFRM_MODE_TRANSPORT:
 100                 if (v->id.proto != IPPROTO_AH)
 101                         return 1;
 102                 else
 103                         return 3;
 104 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 105         case XFRM_MODE_ROUTEOPTIMIZATION:
 106         case XFRM_MODE_IN_TRIGGER:
 107                 return 2;
 108 #endif
 109         case XFRM_MODE_TUNNEL:
 110         case XFRM_MODE_BEET:
 111                 return 4;
 112         }
 113         return 5;
 114 }
 115
 116 static int
 117 __xfrm6_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n)
 118 {
 119         return __xfrm6_sort((void **)dst, (void **)src, n,
 120                             __xfrm6_state_sort_cmp, 6);
 121 }
 122
 123 /*
 124  * Rule for xfrm_tmpl:
 125  *
 126  * rule 1: select IPsec transport
 127  * rule 2: select MIPv6 RO or inbound trigger
 128  * rule 3: select IPsec tunnel
 129  * rule 4: others
 130  */
 131 static int __xfrm6_tmpl_sort_cmp(void *p)
 132 {
 133         struct xfrm_tmpl *v = p;
 134         switch (v->mode) {
 135         case XFRM_MODE_TRANSPORT:
 136                 return 1;
 137 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 138         case XFRM_MODE_ROUTEOPTIMIZATION:
 139         case XFRM_MODE_IN_TRIGGER:
 140                 return 2;
 141 #endif
 142         case XFRM_MODE_TUNNEL:
 143         case XFRM_MODE_BEET:
 144                 return 3;
 145         }
 146         return 4;
 147 }
 148
 149 static int
 150 __xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)
 151 {
 152         return __xfrm6_sort((void **)dst, (void **)src, n,
 153                             __xfrm6_tmpl_sort_cmp, 5);
 154 }
 155
 156 int xfrm6_extract_header(struct sk_buff *skb)
 157 {
 158         struct ipv6hdr *iph = ipv6_hdr(skb);
 159
 160         XFRM_MODE_SKB_CB(skb)->ihl = sizeof(*iph);
 161         XFRM_MODE_SKB_CB(skb)->id = 0;
 162         XFRM_MODE_SKB_CB(skb)->frag_off = htons(IP_DF);
 163         XFRM_MODE_SKB_CB(skb)->tos = ipv6_get_dsfield(iph);
 164         XFRM_MODE_SKB_CB(skb)->ttl = iph->hop_limit;
 165         XFRM_MODE_SKB_CB(skb)->optlen = 0;
 166         memcpy(XFRM_MODE_SKB_CB(skb)->flow_lbl, iph->flow_lbl,
 167                sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
 168
 169         return 0;
 170 }
 171
 172 static struct xfrm_state_afinfo xfrm6_state_afinfo = {
 173         .family                 = AF_INET6,
 174         .proto                  = IPPROTO_IPV6,
 175         .eth_proto              = htons(ETH_P_IPV6),
 176         .owner                  = THIS_MODULE,
 177         .init_tempsel           = __xfrm6_init_tempsel,
 178         .init_temprop           = xfrm6_init_temprop,
 179         .tmpl_sort              = __xfrm6_tmpl_sort,
 180         .state_sort             = __xfrm6_state_sort,
 181         .output                 = xfrm6_output,
 182         .output_finish          = xfrm6_output_finish,
 183         .extract_input          = xfrm6_extract_input,
 184         .extract_output         = xfrm6_extract_output,
 185         .transport_finish       = xfrm6_transport_finish,
 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 }
 197