xref: /linux/include/net/6lowpan.h (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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 #define EUI64_ADDR_LEN		8
62 
63 #define LOWPAN_NHC_MAX_ID_LEN	1
64 /* Maximum next header compression length which we currently support inclusive
65  * possible inline data.
66  */
67 #define LOWPAN_NHC_MAX_HDR_LEN	(sizeof(struct udphdr))
68 /* Max IPHC Header len without IPv6 hdr specific inline data.
69  * Useful for getting the "extra" bytes we need at worst case compression.
70  *
71  * LOWPAN_IPHC + CID + LOWPAN_NHC_MAX_ID_LEN
72  */
73 #define LOWPAN_IPHC_MAX_HEADER_LEN	(2 + 1 + LOWPAN_NHC_MAX_ID_LEN)
74 /* Maximum worst case IPHC header buffer size */
75 #define LOWPAN_IPHC_MAX_HC_BUF_LEN	(sizeof(struct ipv6hdr) +	\
76 					 LOWPAN_IPHC_MAX_HEADER_LEN +	\
77 					 LOWPAN_NHC_MAX_HDR_LEN)
78 
79 #define LOWPAN_DISPATCH_IPV6		0x41 /* 01000001 = 65 */
80 #define LOWPAN_DISPATCH_IPHC		0x60 /* 011xxxxx = ... */
81 #define LOWPAN_DISPATCH_IPHC_MASK	0xe0
82 
83 static inline bool lowpan_is_ipv6(u8 dispatch)
84 {
85 	return dispatch == LOWPAN_DISPATCH_IPV6;
86 }
87 
88 static inline bool lowpan_is_iphc(u8 dispatch)
89 {
90 	return (dispatch & LOWPAN_DISPATCH_IPHC_MASK) == LOWPAN_DISPATCH_IPHC;
91 }
92 
93 #define LOWPAN_PRIV_SIZE(llpriv_size)	\
94 	(sizeof(struct lowpan_priv) + llpriv_size)
95 
96 enum lowpan_lltypes {
97 	LOWPAN_LLTYPE_BTLE,
98 	LOWPAN_LLTYPE_IEEE802154,
99 };
100 
101 struct lowpan_priv {
102 	enum lowpan_lltypes lltype;
103 	struct dentry *iface_debugfs;
104 
105 	/* must be last */
106 	u8 priv[0] __aligned(sizeof(void *));
107 };
108 
109 static inline
110 struct lowpan_priv *lowpan_priv(const struct net_device *dev)
111 {
112 	return netdev_priv(dev);
113 }
114 
115 struct lowpan_802154_cb {
116 	u16 d_tag;
117 	unsigned int d_size;
118 	u8 d_offset;
119 };
120 
121 static inline
122 struct lowpan_802154_cb *lowpan_802154_cb(const struct sk_buff *skb)
123 {
124 	BUILD_BUG_ON(sizeof(struct lowpan_802154_cb) > sizeof(skb->cb));
125 	return (struct lowpan_802154_cb *)skb->cb;
126 }
127 
128 #ifdef DEBUG
129 /* print data in line */
130 static inline void raw_dump_inline(const char *caller, char *msg,
131 				   const unsigned char *buf, int len)
132 {
133 	if (msg)
134 		pr_debug("%s():%s: ", caller, msg);
135 
136 	print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
137 }
138 
139 /* print data in a table format:
140  *
141  * addr: xx xx xx xx xx xx
142  * addr: xx xx xx xx xx xx
143  * ...
144  */
145 static inline void raw_dump_table(const char *caller, char *msg,
146 				  const unsigned char *buf, int len)
147 {
148 	if (msg)
149 		pr_debug("%s():%s:\n", caller, msg);
150 
151 	print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
152 }
153 #else
154 static inline void raw_dump_table(const char *caller, char *msg,
155 				  const unsigned char *buf, int len) { }
156 static inline void raw_dump_inline(const char *caller, char *msg,
157 				   const unsigned char *buf, int len) { }
158 #endif
159 
160 /**
161  * lowpan_fetch_skb - getting inline data from 6LoWPAN header
162  *
163  * This function will pull data from sk buffer and put it into data to
164  * remove the 6LoWPAN inline data. This function returns true if the
165  * sk buffer is too small to pull the amount of data which is specified
166  * by len.
167  *
168  * @skb: the buffer where the inline data should be pulled from.
169  * @data: destination buffer for the inline data.
170  * @len: amount of data which should be pulled in bytes.
171  */
172 static inline bool lowpan_fetch_skb(struct sk_buff *skb, void *data,
173 				    unsigned int len)
174 {
175 	if (unlikely(!pskb_may_pull(skb, len)))
176 		return true;
177 
178 	skb_copy_from_linear_data(skb, data, len);
179 	skb_pull(skb, len);
180 
181 	return false;
182 }
183 
184 static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
185 				       const size_t len)
186 {
187 	memcpy(*hc_ptr, data, len);
188 	*hc_ptr += len;
189 }
190 
191 int lowpan_register_netdevice(struct net_device *dev,
192 			      enum lowpan_lltypes lltype);
193 int lowpan_register_netdev(struct net_device *dev,
194 			   enum lowpan_lltypes lltype);
195 void lowpan_unregister_netdevice(struct net_device *dev);
196 void lowpan_unregister_netdev(struct net_device *dev);
197 
198 /**
199  * lowpan_header_decompress - replace 6LoWPAN header with IPv6 header
200  *
201  * This function replaces the IPHC 6LoWPAN header which should be pointed at
202  * skb->data and skb_network_header, with the IPv6 header.
203  * It would be nice that the caller have the necessary headroom of IPv6 header
204  * and greatest Transport layer header, this would reduce the overhead for
205  * reallocate headroom.
206  *
207  * @skb: the buffer which should be manipulate.
208  * @dev: the lowpan net device pointer.
209  * @daddr: destination lladdr of mac header which is used for compression
210  *	methods.
211  * @saddr: source lladdr of mac header which is used for compression
212  *	methods.
213  */
214 int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
215 			     const void *daddr, const void *saddr);
216 
217 /**
218  * lowpan_header_compress - replace IPv6 header with 6LoWPAN header
219  *
220  * This function replaces the IPv6 header which should be pointed at
221  * skb->data and skb_network_header, with the IPHC 6LoWPAN header.
222  * The caller need to be sure that the sk buffer is not shared and at have
223  * at least a headroom which is smaller or equal LOWPAN_IPHC_MAX_HEADER_LEN,
224  * which is the IPHC "more bytes than IPv6 header" at worst case.
225  *
226  * @skb: the buffer which should be manipulate.
227  * @dev: the lowpan net device pointer.
228  * @daddr: destination lladdr of mac header which is used for compression
229  *	methods.
230  * @saddr: source lladdr of mac header which is used for compression
231  *	methods.
232  */
233 int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
234 			   const void *daddr, const void *saddr);
235 
236 #endif /* __6LOWPAN_H__ */
237