net/6lowpan/ndisc.c

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