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