net/6lowpan/ndisc.c

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