linux/net/6lowpan/ndisc.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *
   4 * Authors:
   5 * (C) 2016 Pengutronix, Alexander Aring <aar@pengutronix.de>
   6 */
   7
   8#include <net/6lowpan.h>
   9#include <net/addrconf.h>
  10#include <net/ndisc.h>
  11
  12#include "6lowpan_i.h"
  13
  14static int lowpan_ndisc_is_useropt(u8 nd_opt_type)
  15{
  16        return nd_opt_type == ND_OPT_6CO;
  17}
  18
  19#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
  20#define NDISC_802154_SHORT_ADDR_LENGTH  1
  21static int lowpan_ndisc_parse_802154_options(const struct net_device *dev,
  22                                             struct nd_opt_hdr *nd_opt,
  23                                             struct ndisc_options *ndopts)
  24{
  25        switch (nd_opt->nd_opt_len) {
  26        case NDISC_802154_SHORT_ADDR_LENGTH:
  27                if (ndopts->nd_802154_opt_array[nd_opt->nd_opt_type])
  28                        ND_PRINTK(2, warn,
  29                                  "%s: duplicated short addr ND6 option found: type=%d\n",
  30                                  __func__, nd_opt->nd_opt_type);
  31                else
  32                        ndopts->nd_802154_opt_array[nd_opt->nd_opt_type] = nd_opt;
  33                return 1;
  34        default:
  35                /* all others will be handled by ndisc IPv6 option parsing */
  36                return 0;
  37        }
  38}
  39
  40static int lowpan_ndisc_parse_options(const struct net_device *dev,
  41                                      struct nd_opt_hdr *nd_opt,
  42                                      struct ndisc_options *ndopts)
  43{
  44        if (!lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154))
  45                return 0;
  46
  47        switch (nd_opt->nd_opt_type) {
  48        case ND_OPT_SOURCE_LL_ADDR:
  49        case ND_OPT_TARGET_LL_ADDR:
  50                return lowpan_ndisc_parse_802154_options(dev, nd_opt, ndopts);
  51        default:
  52                return 0;
  53        }
  54}
  55
  56static void lowpan_ndisc_802154_update(struct neighbour *n, u32 flags,
  57                                       u8 icmp6_type,
  58                                       const struct ndisc_options *ndopts)
  59{
  60        struct lowpan_802154_neigh *neigh = lowpan_802154_neigh(neighbour_priv(n));
  61        u8 *lladdr_short = NULL;
  62
  63        switch (icmp6_type) {
  64        case NDISC_ROUTER_SOLICITATION:
  65        case NDISC_ROUTER_ADVERTISEMENT:
  66        case NDISC_NEIGHBOUR_SOLICITATION:
  67                if (ndopts->nd_802154_opts_src_lladdr) {
  68                        lladdr_short = __ndisc_opt_addr_data(ndopts->nd_802154_opts_src_lladdr,
  69                                                             IEEE802154_SHORT_ADDR_LEN, 0);
  70                        if (!lladdr_short) {
  71                                ND_PRINTK(2, warn,
  72                                          "NA: invalid short link-layer address length\n");
  73                                return;
  74                        }
  75                }
  76                break;
  77        case NDISC_REDIRECT:
  78        case NDISC_NEIGHBOUR_ADVERTISEMENT:
  79                if (ndopts->nd_802154_opts_tgt_lladdr) {
  80                        lladdr_short = __ndisc_opt_addr_data(ndopts->nd_802154_opts_tgt_lladdr,
  81                                                             IEEE802154_SHORT_ADDR_LEN, 0);
  82                        if (!lladdr_short) {
  83                                ND_PRINTK(2, warn,
  84                                          "NA: invalid short link-layer address length\n");
  85                                return;
  86                        }
  87                }
  88                break;
  89        default:
  90                break;
  91        }
  92
  93        write_lock_bh(&n->lock);
  94        if (lladdr_short) {
  95                ieee802154_be16_to_le16(&neigh->short_addr, lladdr_short);
  96                if (!lowpan_802154_is_valid_src_short_addr(neigh->short_addr))
  97                        neigh->short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
  98        }
  99        write_unlock_bh(&n->lock);
 100}
 101
 102static void lowpan_ndisc_update(const struct net_device *dev,
 103                                struct neighbour *n, u32 flags, u8 icmp6_type,
 104                                const struct ndisc_options *ndopts)
 105{
 106        if (!lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154))
 107                return;
 108
 109        /* react on overrides only. TODO check if this is really right. */
 110        if (flags & NEIGH_UPDATE_F_OVERRIDE)
 111                lowpan_ndisc_802154_update(n, flags, icmp6_type, ndopts);
 112}
 113
 114static int lowpan_ndisc_opt_addr_space(const struct net_device *dev,
 115                                       u8 icmp6_type, struct neighbour *neigh,
 116                                       u8 *ha_buf, u8 **ha)
 117{
 118        struct lowpan_802154_neigh *n;
 119        struct wpan_dev *wpan_dev;
 120        int addr_space = 0;
 121
 122        if (!lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154))
 123                return 0;
 124
 125        switch (icmp6_type) {
 126        case NDISC_REDIRECT:
 127                n = lowpan_802154_neigh(neighbour_priv(neigh));
 128
 129                read_lock_bh(&neigh->lock);
 130                if (lowpan_802154_is_valid_src_short_addr(n->short_addr)) {
 131                        memcpy(ha_buf, &n->short_addr,
 132                               IEEE802154_SHORT_ADDR_LEN);
 133                        read_unlock_bh(&neigh->lock);
 134                        addr_space += __ndisc_opt_addr_space(IEEE802154_SHORT_ADDR_LEN, 0);
 135                        *ha = ha_buf;
 136                } else {
 137                        read_unlock_bh(&neigh->lock);
 138                }
 139                break;
 140        case NDISC_NEIGHBOUR_ADVERTISEMENT:
 141        case NDISC_NEIGHBOUR_SOLICITATION:
 142        case NDISC_ROUTER_SOLICITATION:
 143                wpan_dev = lowpan_802154_dev(dev)->wdev->ieee802154_ptr;
 144
 145                if (lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr))
 146                        addr_space = __ndisc_opt_addr_space(IEEE802154_SHORT_ADDR_LEN, 0);
 147                break;
 148        default:
 149                break;
 150        }
 151
 152        return addr_space;
 153}
 154
 155static void lowpan_ndisc_fill_addr_option(const struct net_device *dev,
 156                                          struct sk_buff *skb, u8 icmp6_type,
 157                                          const u8 *ha)
 158{
 159        struct wpan_dev *wpan_dev;
 160        __be16 short_addr;
 161        u8 opt_type;
 162
 163        if (!lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154))
 164                return;
 165
 166        switch (icmp6_type) {
 167        case NDISC_REDIRECT:
 168                if (ha) {
 169                        ieee802154_le16_to_be16(&short_addr, ha);
 170                        __ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
 171                                                 &short_addr,
 172                                                 IEEE802154_SHORT_ADDR_LEN, 0);
 173                }
 174                return;
 175        case NDISC_NEIGHBOUR_ADVERTISEMENT:
 176                opt_type = ND_OPT_TARGET_LL_ADDR;
 177                break;
 178        case NDISC_ROUTER_SOLICITATION:
 179        case NDISC_NEIGHBOUR_SOLICITATION:
 180                opt_type = ND_OPT_SOURCE_LL_ADDR;
 181                break;
 182        default:
 183                return;
 184        }
 185
 186        wpan_dev = lowpan_802154_dev(dev)->wdev->ieee802154_ptr;
 187
 188        if (lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr)) {
 189                ieee802154_le16_to_be16(&short_addr,
 190                                        &wpan_dev->short_addr);
 191                __ndisc_fill_addr_option(skb, opt_type, &short_addr,
 192                                         IEEE802154_SHORT_ADDR_LEN, 0);
 193        }
 194}
 195
 196static void lowpan_ndisc_prefix_rcv_add_addr(struct net *net,
 197                                             struct net_device *dev,
 198                                             const struct prefix_info *pinfo,
 199                                             struct inet6_dev *in6_dev,
 200                                             struct in6_addr *addr,
 201                                             int addr_type, u32 addr_flags,
 202                                             bool sllao, bool tokenized,
 203                                             __u32 valid_lft,
 204                                             u32 prefered_lft,
 205                                             bool dev_addr_generated)
 206{
 207        int err;
 208
 209        /* generates short based address for RA PIO's */
 210        if (lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154) && dev_addr_generated &&
 211            !addrconf_ifid_802154_6lowpan(addr->s6_addr + 8, dev)) {
 212                err = addrconf_prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
 213                                                   addr, addr_type, addr_flags,
 214                                                   sllao, tokenized, valid_lft,
 215                                                   prefered_lft);
 216                if (err)
 217                        ND_PRINTK(2, warn,
 218                                  "RA: could not add a short address based address for prefix: %pI6c\n",
 219                                  &pinfo->prefix);
 220        }
 221}
 222#endif
 223
 224const struct ndisc_ops lowpan_ndisc_ops = {
 225        .is_useropt             = lowpan_ndisc_is_useropt,
 226#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 227        .parse_options          = lowpan_ndisc_parse_options,
 228        .update                 = lowpan_ndisc_update,
 229        .opt_addr_space         = lowpan_ndisc_opt_addr_space,
 230        .fill_addr_option       = lowpan_ndisc_fill_addr_option,
 231        .prefix_rcv_add_addr    = lowpan_ndisc_prefix_rcv_add_addr,
 232#endif
 233};
 234