xref: /linux/net/6lowpan/ndisc.c (revision a36e9f5cfe9eb3a1dce8769c7058251c42705357)
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 };
228