1 /*
2  * Copyright 2011, Siemens AG
3  * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
4  */
5 
6 /*
7  * Based on patches from Jon Smirl <jonsmirl@gmail.com>
8  * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2
12  * as published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License along
20  * with this program; if not, write to the Free Software Foundation, Inc.,
21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22  */
23 
24 /* Jon's code is based on 6lowpan implementation for Contiki which is:
25  * Copyright (c) 2008, Swedish Institute of Computer Science.
26  * All rights reserved.
27  *
28  * Redistribution and use in source and binary forms, with or without
29  * modification, are permitted provided that the following conditions
30  * are met:
31  * 1. Redistributions of source code must retain the above copyright
32  *    notice, this list of conditions and the following disclaimer.
33  * 2. Redistributions in binary form must reproduce the above copyright
34  *    notice, this list of conditions and the following disclaimer in the
35  *    documentation and/or other materials provided with the distribution.
36  * 3. Neither the name of the Institute nor the names of its contributors
37  *    may be used to endorse or promote products derived from this software
38  *    without specific prior written permission.
39  *
40  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  */
52 
53 #ifndef __6LOWPAN_H__
54 #define __6LOWPAN_H__
55 
56 #include <linux/debugfs.h>
57 
58 #include <net/ipv6.h>
59 #include <net/net_namespace.h>
60 
61 /* special link-layer handling */
62 #include <net/mac802154.h>
63 
64 #define EUI64_ADDR_LEN		8
65 
66 #define LOWPAN_NHC_MAX_ID_LEN	1
67 /* Maximum next header compression length which we currently support inclusive
68  * possible inline data.
69  */
70 #define LOWPAN_NHC_MAX_HDR_LEN	(sizeof(struct udphdr))
71 /* Max IPHC Header len without IPv6 hdr specific inline data.
72  * Useful for getting the "extra" bytes we need at worst case compression.
73  *
74  * LOWPAN_IPHC + CID + LOWPAN_NHC_MAX_ID_LEN
75  */
76 #define LOWPAN_IPHC_MAX_HEADER_LEN	(2 + 1 + LOWPAN_NHC_MAX_ID_LEN)
77 /* Maximum worst case IPHC header buffer size */
78 #define LOWPAN_IPHC_MAX_HC_BUF_LEN	(sizeof(struct ipv6hdr) +	\
79 					 LOWPAN_IPHC_MAX_HEADER_LEN +	\
80 					 LOWPAN_NHC_MAX_HDR_LEN)
81 /* SCI/DCI is 4 bit width, so we have maximum 16 entries */
82 #define LOWPAN_IPHC_CTX_TABLE_SIZE	(1 << 4)
83 
84 #define LOWPAN_DISPATCH_IPV6		0x41 /* 01000001 = 65 */
85 #define LOWPAN_DISPATCH_IPHC		0x60 /* 011xxxxx = ... */
86 #define LOWPAN_DISPATCH_IPHC_MASK	0xe0
87 
lowpan_is_ipv6(u8 dispatch)88 static inline bool lowpan_is_ipv6(u8 dispatch)
89 {
90 	return dispatch == LOWPAN_DISPATCH_IPV6;
91 }
92 
lowpan_is_iphc(u8 dispatch)93 static inline bool lowpan_is_iphc(u8 dispatch)
94 {
95 	return (dispatch & LOWPAN_DISPATCH_IPHC_MASK) == LOWPAN_DISPATCH_IPHC;
96 }
97 
98 #define LOWPAN_PRIV_SIZE(llpriv_size)	\
99 	(sizeof(struct lowpan_dev) + llpriv_size)
100 
101 enum lowpan_lltypes {
102 	LOWPAN_LLTYPE_BTLE,
103 	LOWPAN_LLTYPE_IEEE802154,
104 };
105 
106 enum lowpan_iphc_ctx_flags {
107 	LOWPAN_IPHC_CTX_FLAG_ACTIVE,
108 	LOWPAN_IPHC_CTX_FLAG_COMPRESSION,
109 };
110 
111 struct lowpan_iphc_ctx {
112 	u8 id;
113 	struct in6_addr pfx;
114 	u8 plen;
115 	unsigned long flags;
116 };
117 
118 struct lowpan_iphc_ctx_table {
119 	spinlock_t lock;
120 	const struct lowpan_iphc_ctx_ops *ops;
121 	struct lowpan_iphc_ctx table[LOWPAN_IPHC_CTX_TABLE_SIZE];
122 };
123 
lowpan_iphc_ctx_is_active(const struct lowpan_iphc_ctx * ctx)124 static inline bool lowpan_iphc_ctx_is_active(const struct lowpan_iphc_ctx *ctx)
125 {
126 	return test_bit(LOWPAN_IPHC_CTX_FLAG_ACTIVE, &ctx->flags);
127 }
128 
129 static inline bool
lowpan_iphc_ctx_is_compression(const struct lowpan_iphc_ctx * ctx)130 lowpan_iphc_ctx_is_compression(const struct lowpan_iphc_ctx *ctx)
131 {
132 	return test_bit(LOWPAN_IPHC_CTX_FLAG_COMPRESSION, &ctx->flags);
133 }
134 
135 struct lowpan_dev {
136 	enum lowpan_lltypes lltype;
137 	struct dentry *iface_debugfs;
138 	struct lowpan_iphc_ctx_table ctx;
139 
140 	/* must be last */
141 	u8 priv[] __aligned(sizeof(void *));
142 };
143 
144 struct lowpan_802154_neigh {
145 	__le16 short_addr;
146 };
147 
148 static inline
lowpan_802154_neigh(void * neigh_priv)149 struct lowpan_802154_neigh *lowpan_802154_neigh(void *neigh_priv)
150 {
151 	return neigh_priv;
152 }
153 
154 static inline
lowpan_dev(const struct net_device * dev)155 struct lowpan_dev *lowpan_dev(const struct net_device *dev)
156 {
157 	return netdev_priv(dev);
158 }
159 
160 /* private device info */
161 struct lowpan_802154_dev {
162 	struct net_device	*wdev; /* wpan device ptr */
163 	u16			fragment_tag;
164 };
165 
166 static inline struct
lowpan_802154_dev(const struct net_device * dev)167 lowpan_802154_dev *lowpan_802154_dev(const struct net_device *dev)
168 {
169 	return (struct lowpan_802154_dev *)lowpan_dev(dev)->priv;
170 }
171 
172 struct lowpan_802154_cb {
173 	u16 d_tag;
174 	unsigned int d_size;
175 	u8 d_offset;
176 };
177 
178 static inline
lowpan_802154_cb(const struct sk_buff * skb)179 struct lowpan_802154_cb *lowpan_802154_cb(const struct sk_buff *skb)
180 {
181 	BUILD_BUG_ON(sizeof(struct lowpan_802154_cb) > sizeof(skb->cb));
182 	return (struct lowpan_802154_cb *)skb->cb;
183 }
184 
lowpan_iphc_uncompress_eui64_lladdr(struct in6_addr * ipaddr,const void * lladdr)185 static inline void lowpan_iphc_uncompress_eui64_lladdr(struct in6_addr *ipaddr,
186 						       const void *lladdr)
187 {
188 	/* fe:80::XXXX:XXXX:XXXX:XXXX
189 	 *        \_________________/
190 	 *              hwaddr
191 	 */
192 	ipaddr->s6_addr[0] = 0xFE;
193 	ipaddr->s6_addr[1] = 0x80;
194 	memcpy(&ipaddr->s6_addr[8], lladdr, EUI64_ADDR_LEN);
195 	/* second bit-flip (Universe/Local)
196 	 * is done according RFC2464
197 	 */
198 	ipaddr->s6_addr[8] ^= 0x02;
199 }
200 
lowpan_iphc_uncompress_eui48_lladdr(struct in6_addr * ipaddr,const void * lladdr)201 static inline void lowpan_iphc_uncompress_eui48_lladdr(struct in6_addr *ipaddr,
202 						       const void *lladdr)
203 {
204 	/* fe:80::XXXX:XXff:feXX:XXXX
205 	 *        \_________________/
206 	 *              hwaddr
207 	 */
208 	ipaddr->s6_addr[0] = 0xFE;
209 	ipaddr->s6_addr[1] = 0x80;
210 	memcpy(&ipaddr->s6_addr[8], lladdr, 3);
211 	ipaddr->s6_addr[11] = 0xFF;
212 	ipaddr->s6_addr[12] = 0xFE;
213 	memcpy(&ipaddr->s6_addr[13], lladdr + 3, 3);
214 }
215 
216 #ifdef DEBUG
217 /* print data in line */
raw_dump_inline(const char * caller,char * msg,const unsigned char * buf,int len)218 static inline void raw_dump_inline(const char *caller, char *msg,
219 				   const unsigned char *buf, int len)
220 {
221 	if (msg)
222 		pr_debug("%s():%s: ", caller, msg);
223 
224 	print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
225 }
226 
227 /* print data in a table format:
228  *
229  * addr: xx xx xx xx xx xx
230  * addr: xx xx xx xx xx xx
231  * ...
232  */
raw_dump_table(const char * caller,char * msg,const unsigned char * buf,int len)233 static inline void raw_dump_table(const char *caller, char *msg,
234 				  const unsigned char *buf, int len)
235 {
236 	if (msg)
237 		pr_debug("%s():%s:\n", caller, msg);
238 
239 	print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
240 }
241 #else
raw_dump_table(const char * caller,char * msg,const unsigned char * buf,int len)242 static inline void raw_dump_table(const char *caller, char *msg,
243 				  const unsigned char *buf, int len) { }
raw_dump_inline(const char * caller,char * msg,const unsigned char * buf,int len)244 static inline void raw_dump_inline(const char *caller, char *msg,
245 				   const unsigned char *buf, int len) { }
246 #endif
247 
248 /**
249  * lowpan_fetch_skb - getting inline data from 6LoWPAN header
250  *
251  * This function will pull data from sk buffer and put it into data to
252  * remove the 6LoWPAN inline data. This function returns true if the
253  * sk buffer is too small to pull the amount of data which is specified
254  * by len.
255  *
256  * @skb: the buffer where the inline data should be pulled from.
257  * @data: destination buffer for the inline data.
258  * @len: amount of data which should be pulled in bytes.
259  */
lowpan_fetch_skb(struct sk_buff * skb,void * data,unsigned int len)260 static inline bool lowpan_fetch_skb(struct sk_buff *skb, void *data,
261 				    unsigned int len)
262 {
263 	if (unlikely(!pskb_may_pull(skb, len)))
264 		return true;
265 
266 	skb_copy_from_linear_data(skb, data, len);
267 	skb_pull(skb, len);
268 
269 	return false;
270 }
271 
lowpan_802154_is_valid_src_short_addr(__le16 addr)272 static inline bool lowpan_802154_is_valid_src_short_addr(__le16 addr)
273 {
274 	/* First bit of addr is multicast, reserved or 802.15.4 specific */
275 	return !(addr & cpu_to_le16(0x8000));
276 }
277 
lowpan_push_hc_data(u8 ** hc_ptr,const void * data,const size_t len)278 static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
279 				       const size_t len)
280 {
281 	memcpy(*hc_ptr, data, len);
282 	*hc_ptr += len;
283 }
284 
285 int lowpan_register_netdevice(struct net_device *dev,
286 			      enum lowpan_lltypes lltype);
287 int lowpan_register_netdev(struct net_device *dev,
288 			   enum lowpan_lltypes lltype);
289 void lowpan_unregister_netdevice(struct net_device *dev);
290 void lowpan_unregister_netdev(struct net_device *dev);
291 
292 /**
293  * lowpan_header_decompress - replace 6LoWPAN header with IPv6 header
294  *
295  * This function replaces the IPHC 6LoWPAN header which should be pointed at
296  * skb->data and skb_network_header, with the IPv6 header.
297  * It would be nice that the caller have the necessary headroom of IPv6 header
298  * and greatest Transport layer header, this would reduce the overhead for
299  * reallocate headroom.
300  *
301  * @skb: the buffer which should be manipulate.
302  * @dev: the lowpan net device pointer.
303  * @daddr: destination lladdr of mac header which is used for compression
304  *	methods.
305  * @saddr: source lladdr of mac header which is used for compression
306  *	methods.
307  */
308 int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
309 			     const void *daddr, const void *saddr);
310 
311 /**
312  * lowpan_header_compress - replace IPv6 header with 6LoWPAN header
313  *
314  * This function replaces the IPv6 header which should be pointed at
315  * skb->data and skb_network_header, with the IPHC 6LoWPAN header.
316  * The caller need to be sure that the sk buffer is not shared and at have
317  * at least a headroom which is smaller or equal LOWPAN_IPHC_MAX_HEADER_LEN,
318  * which is the IPHC "more bytes than IPv6 header" at worst case.
319  *
320  * @skb: the buffer which should be manipulate.
321  * @dev: the lowpan net device pointer.
322  * @daddr: destination lladdr of mac header which is used for compression
323  *	methods.
324  * @saddr: source lladdr of mac header which is used for compression
325  *	methods.
326  */
327 int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
328 			   const void *daddr, const void *saddr);
329 
330 #endif /* __6LOWPAN_H__ */
331