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 <net/dsfield.h>
  19 #include <net/ipv6.h>
  20 #include <net/addrconf.h>
  21
  22 static struct xfrm_state_afinfo xfrm6_state_afinfo;
  23
  24 static void
  25 __xfrm6_init_tempsel(struct xfrm_state *x, struct flowi *fl,
  26                      struct xfrm_tmpl *tmpl,
  27                      xfrm_address_t *daddr, xfrm_address_t *saddr)
  28 {
  29         /* Initialize temporary selector matching only
  30          * to current session. */
  31         ipv6_addr_copy((struct in6_addr *)&x->sel.daddr, &fl->fl6_dst);
  32         ipv6_addr_copy((struct in6_addr *)&x->sel.saddr, &fl->fl6_src);
  33         x->sel.dport = xfrm_flowi_dport(fl);
  34         x->sel.dport_mask = htons(0xffff);
  35         x->sel.sport = xfrm_flowi_sport(fl);
  36         x->sel.sport_mask = htons(0xffff);
  37         x->sel.prefixlen_d = 128;
  38         x->sel.prefixlen_s = 128;
  39         x->sel.proto = fl->proto;
  40         x->sel.ifindex = fl->oif;
  41         x->id = tmpl->id;
  42         if (ipv6_addr_any((struct in6_addr*)&x->id.daddr))
  43                 memcpy(&x->id.daddr, daddr, sizeof(x->sel.daddr));
  44         memcpy(&x->props.saddr, &tmpl->saddr, sizeof(x->props.saddr));
  45         if (ipv6_addr_any((struct in6_addr*)&x->props.saddr))
  46                 memcpy(&x->props.saddr, saddr, sizeof(x->props.saddr));
  47         x->props.mode = tmpl->mode;
  48         x->props.reqid = tmpl->reqid;
  49         x->props.family = AF_INET6;
  50 }
  51
  52 static int
  53 __xfrm6_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n)
  54 {
  55         int i;
  56         int j = 0;
  57
  58         /* Rule 1: select IPsec transport except AH */
  59         for (i = 0; i < n; i++) {
  60                 if (src[i]->props.mode == XFRM_MODE_TRANSPORT &&
  61                     src[i]->id.proto != IPPROTO_AH) {
  62                         dst[j++] = src[i];
  63                         src[i] = NULL;
  64                 }
  65         }
  66         if (j == n)
  67                 goto end;
  68
  69         /* Rule 2: select MIPv6 RO or inbound trigger */
  70 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
  71         for (i = 0; i < n; i++) {
  72                 if (src[i] &&
  73                     (src[i]->props.mode == XFRM_MODE_ROUTEOPTIMIZATION ||
  74                      src[i]->props.mode == XFRM_MODE_IN_TRIGGER)) {
  75                         dst[j++] = src[i];
  76                         src[i] = NULL;
  77                 }
  78         }
  79         if (j == n)
  80                 goto end;
  81 #endif
  82
  83         /* Rule 3: select IPsec transport AH */
  84         for (i = 0; i < n; i++) {
  85                 if (src[i] &&
  86                     src[i]->props.mode == XFRM_MODE_TRANSPORT &&
  87                     src[i]->id.proto == IPPROTO_AH) {
  88                         dst[j++] = src[i];
  89                         src[i] = NULL;
  90                 }
  91         }
  92         if (j == n)
  93                 goto end;
  94
  95         /* Rule 4: select IPsec tunnel */
  96         for (i = 0; i < n; i++) {
  97                 if (src[i] &&
  98                     (src[i]->props.mode == XFRM_MODE_TUNNEL ||
  99                      src[i]->props.mode == XFRM_MODE_BEET)) {
 100                         dst[j++] = src[i];
 101                         src[i] = NULL;
 102                 }
 103         }
 104         if (likely(j == n))
 105                 goto end;
 106
 107         /* Final rule */
 108         for (i = 0; i < n; i++) {
 109                 if (src[i]) {
 110                         dst[j++] = src[i];
 111                         src[i] = NULL;
 112                 }
 113         }
 114
 115  end:
 116         return 0;
 117 }
 118
 119 static int
 120 __xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)
 121 {
 122         int i;
 123         int j = 0;
 124
 125         /* Rule 1: select IPsec transport */
 126         for (i = 0; i < n; i++) {
 127                 if (src[i]->mode == XFRM_MODE_TRANSPORT) {
 128                         dst[j++] = src[i];
 129                         src[i] = NULL;
 130                 }
 131         }
 132         if (j == n)
 133                 goto end;
 134
 135         /* Rule 2: select MIPv6 RO or inbound trigger */
 136 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 137         for (i = 0; i < n; i++) {
 138                 if (src[i] &&
 139                     (src[i]->mode == XFRM_MODE_ROUTEOPTIMIZATION ||
 140                      src[i]->mode == XFRM_MODE_IN_TRIGGER)) {
 141                         dst[j++] = src[i];
 142                         src[i] = NULL;
 143                 }
 144         }
 145         if (j == n)
 146                 goto end;
 147 #endif
 148
 149         /* Rule 3: select IPsec tunnel */
 150         for (i = 0; i < n; i++) {
 151                 if (src[i] &&
 152                     (src[i]->mode == XFRM_MODE_TUNNEL ||
 153                      src[i]->mode == XFRM_MODE_BEET)) {
 154                         dst[j++] = src[i];
 155                         src[i] = NULL;
 156                 }
 157         }
 158         if (likely(j == n))
 159                 goto end;
 160
 161         /* Final rule */
 162         for (i = 0; i < n; i++) {
 163                 if (src[i]) {
 164                         dst[j++] = src[i];
 165                         src[i] = NULL;
 166                 }
 167         }
 168
 169  end:
 170         return 0;
 171 }
 172
 173 int xfrm6_extract_header(struct sk_buff *skb)
 174 {
 175         struct ipv6hdr *iph = ipv6_hdr(skb);
 176
 177         XFRM_MODE_SKB_CB(skb)->id = 0;
 178         XFRM_MODE_SKB_CB(skb)->frag_off = htons(IP_DF);
 179         XFRM_MODE_SKB_CB(skb)->tos = ipv6_get_dsfield(iph);
 180         XFRM_MODE_SKB_CB(skb)->ttl = iph->hop_limit;
 181         memcpy(XFRM_MODE_SKB_CB(skb)->flow_lbl, iph->flow_lbl,
 182                sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
 183
 184         return 0;
 185 }
 186
 187 static struct xfrm_state_afinfo xfrm6_state_afinfo = {
 188         .family                 = AF_INET6,
 189         .proto                  = IPPROTO_IPV6,
 190         .eth_proto              = htons(ETH_P_IPV6),
 191         .owner                  = THIS_MODULE,
 192         .init_tempsel           = __xfrm6_init_tempsel,
 193         .tmpl_sort              = __xfrm6_tmpl_sort,
 194         .state_sort             = __xfrm6_state_sort,
 195         .output                 = xfrm6_output,
 196         .extract_input          = xfrm6_extract_input,
 197         .extract_output         = xfrm6_extract_output,
 198         .transport_finish       = xfrm6_transport_finish,
 199 };
 200
 201 int __init xfrm6_state_init(void)
 202 {
 203         return xfrm_state_register_afinfo(&xfrm6_state_afinfo);
 204 }
 205
 206 void xfrm6_state_fini(void)
 207 {
 208         xfrm_state_unregister_afinfo(&xfrm6_state_afinfo);
 209 }
 210