linux/net/ipv6/xfrm6_state.c
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   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
  24static 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
  44static void
  45xfrm6_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 */
  60static 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 */
  93static 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
 115static 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 */
 130static 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
 148static 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
 155int 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
 171static 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
 188int __init xfrm6_state_init(void)
 189{
 190        return xfrm_state_register_afinfo(&xfrm6_state_afinfo);
 191}
 192
 193void xfrm6_state_fini(void)
 194{
 195        xfrm_state_unregister_afinfo(&xfrm6_state_afinfo);
 196}
 197