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         if (!lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154))
  51                 return 0;
  52
  53         switch (nd_opt->nd_opt_type) {
  54         case ND_OPT_SOURCE_LL_ADDR:
  55         case ND_OPT_TARGET_LL_ADDR:
  56                 return lowpan_ndisc_parse_802154_options(dev, nd_opt, ndopts);
  57         default:
  58                 return 0;
  59         }
  60 }
  61
  62 static void lowpan_ndisc_802154_update(struct neighbour *n, u32 flags,
  63                                        u8 icmp6_type,
  64                                        const struct ndisc_options *ndopts)
  65 {
  66         struct lowpan_802154_neigh *neigh = lowpan_802154_neigh(neighbour_priv(n));
  67         u8 *lladdr_short = NULL;
  68
  69         switch (icmp6_type) {
  70         case NDISC_ROUTER_SOLICITATION:
  71         case NDISC_ROUTER_ADVERTISEMENT:
  72         case NDISC_NEIGHBOUR_SOLICITATION:
  73                 if (ndopts->nd_802154_opts_src_lladdr) {
  74                         lladdr_short = __ndisc_opt_addr_data(ndopts->nd_802154_opts_src_lladdr,
  75                                                              IEEE802154_SHORT_ADDR_LEN, 0);
  76                         if (!lladdr_short) {
  77                                 ND_PRINTK(2, warn,
  78                                           "NA: invalid short link-layer address length\n");
  79                                 return;
  80                         }
  81                 }
  82                 break;
  83         case NDISC_REDIRECT:
  84         case NDISC_NEIGHBOUR_ADVERTISEMENT:
  85                 if (ndopts->nd_802154_opts_tgt_lladdr) {
  86                         lladdr_short = __ndisc_opt_addr_data(ndopts->nd_802154_opts_tgt_lladdr,
  87                                                              IEEE802154_SHORT_ADDR_LEN, 0);
  88                         if (!lladdr_short) {
  89                                 ND_PRINTK(2, warn,
  90                                           "NA: invalid short link-layer address length\n");
  91                                 return;
  92                         }
  93                 }
  94                 break;
  95         default:
  96                 break;
  97         }
  98
  99         write_lock_bh(&n->lock);
 100         if (lladdr_short) {
 101                 ieee802154_be16_to_le16(&neigh->short_addr, lladdr_short);
 102                 if (!lowpan_802154_is_valid_src_short_addr(neigh->short_addr))
 103                         neigh->short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
 104         }
 105         write_unlock_bh(&n->lock);
 106 }
 107
 108 static void lowpan_ndisc_update(const struct net_device *dev,
 109                                 struct neighbour *n, u32 flags, u8 icmp6_type,
 110                                 const struct ndisc_options *ndopts)
 111 {
 112         if (!lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154))
 113                 return;
 114
 115         /* react on overrides only. TODO check if this is really right. */
 116         if (flags & NEIGH_UPDATE_F_OVERRIDE)
 117                 lowpan_ndisc_802154_update(n, flags, icmp6_type, ndopts);
 118 }
 119
 120 static int lowpan_ndisc_opt_addr_space(const struct net_device *dev,
 121                                        u8 icmp6_type, struct neighbour *neigh,
 122                                        u8 *ha_buf, u8 **ha)
 123 {
 124         struct lowpan_802154_neigh *n;
 125         struct wpan_dev *wpan_dev;
 126         int addr_space = 0;
 127
 128         if (!lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154))
 129                 return 0;
 130
 131         switch (icmp6_type) {
 132         case NDISC_REDIRECT:
 133                 n = lowpan_802154_neigh(neighbour_priv(neigh));
 134
 135                 read_lock_bh(&neigh->lock);
 136                 if (lowpan_802154_is_valid_src_short_addr(n->short_addr)) {
 137                         memcpy(ha_buf, &n->short_addr,
 138                                IEEE802154_SHORT_ADDR_LEN);
 139                         read_unlock_bh(&neigh->lock);
 140                         addr_space += __ndisc_opt_addr_space(IEEE802154_SHORT_ADDR_LEN, 0);
 141                         *ha = ha_buf;
 142                 } else {
 143                         read_unlock_bh(&neigh->lock);
 144                 }
 145                 break;
 146         case NDISC_NEIGHBOUR_ADVERTISEMENT:
 147         case NDISC_NEIGHBOUR_SOLICITATION:
 148         case NDISC_ROUTER_SOLICITATION:
 149                 wpan_dev = lowpan_802154_dev(dev)->wdev->ieee802154_ptr;
 150
 151                 if (lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr))
 152                         addr_space = __ndisc_opt_addr_space(IEEE802154_SHORT_ADDR_LEN, 0);
 153                 break;
 154         default:
 155                 break;
 156         }
 157
 158         return addr_space;
 159 }
 160
 161 static void lowpan_ndisc_fill_addr_option(const struct net_device *dev,
 162                                           struct sk_buff *skb, u8 icmp6_type,
 163                                           const u8 *ha)
 164 {
 165         struct wpan_dev *wpan_dev;
 166         __be16 short_addr;
 167         u8 opt_type;
 168
 169         if (!lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154))
 170                 return;
 171
 172         switch (icmp6_type) {
 173         case NDISC_REDIRECT:
 174                 if (ha) {
 175                         ieee802154_le16_to_be16(&short_addr, ha);
 176                         __ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
 177                                                  &short_addr,
 178                                                  IEEE802154_SHORT_ADDR_LEN, 0);
 179                 }
 180                 return;
 181         case NDISC_NEIGHBOUR_ADVERTISEMENT:
 182                 opt_type = ND_OPT_TARGET_LL_ADDR;
 183                 break;
 184         case NDISC_ROUTER_SOLICITATION:
 185         case NDISC_NEIGHBOUR_SOLICITATION:
 186                 opt_type = ND_OPT_SOURCE_LL_ADDR;
 187                 break;
 188         default:
 189                 return;
 190         }
 191
 192         wpan_dev = lowpan_802154_dev(dev)->wdev->ieee802154_ptr;
 193
 194         if (lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr)) {
 195                 ieee802154_le16_to_be16(&short_addr,
 196                                         &wpan_dev->short_addr);
 197                 __ndisc_fill_addr_option(skb, opt_type, &short_addr,
 198                                          IEEE802154_SHORT_ADDR_LEN, 0);
 199         }
 200 }
 201
 202 static void lowpan_ndisc_prefix_rcv_add_addr(struct net *net,
 203                                              struct net_device *dev,
 204                                              const struct prefix_info *pinfo,
 205                                              struct inet6_dev *in6_dev,
 206                                              struct in6_addr *addr,
 207                                              int addr_type, u32 addr_flags,
 208                                              bool sllao, bool tokenized,
 209                                              __u32 valid_lft,
 210                                              u32 prefered_lft,
 211                                              bool dev_addr_generated)
 212 {
 213         int err;
 214
 215         /* generates short based address for RA PIO's */
 216         if (lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154) && dev_addr_generated &&
 217             !addrconf_ifid_802154_6lowpan(addr->s6_addr + 8, dev)) {
 218                 err = addrconf_prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
 219                                                    addr, addr_type, addr_flags,
 220                                                    sllao, tokenized, valid_lft,
 221                                                    prefered_lft);
 222                 if (err)
 223                         ND_PRINTK(2, warn,
 224                                   "RA: could not add a short address based address for prefix: %pI6c\n",
 225                                   &pinfo->prefix);
 226         }
 227 }
 228 #endif
 229
 230 const struct ndisc_ops lowpan_ndisc_ops = {
 231         .is_useropt             = lowpan_ndisc_is_useropt,
 232 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 233         .parse_options          = lowpan_ndisc_parse_options,
 234         .update                 = lowpan_ndisc_update,
 235         .opt_addr_space         = lowpan_ndisc_opt_addr_space,
 236         .fill_addr_option       = lowpan_ndisc_fill_addr_option,
 237         .prefix_rcv_add_addr    = lowpan_ndisc_prefix_rcv_add_addr,
 238 #endif
 239 };