tjh.dev
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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
88static inline bool lowpan_is_ipv6(u8 dispatch)
89{
90 return dispatch == LOWPAN_DISPATCH_IPV6;
91}
92
93static 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
101enum lowpan_lltypes {
102 LOWPAN_LLTYPE_BTLE,
103 LOWPAN_LLTYPE_IEEE802154,
104};
105
106enum lowpan_iphc_ctx_flags {
107 LOWPAN_IPHC_CTX_FLAG_ACTIVE,
108 LOWPAN_IPHC_CTX_FLAG_COMPRESSION,
109};
110
111struct lowpan_iphc_ctx {
112 u8 id;
113 struct in6_addr pfx;
114 u8 plen;
115 unsigned long flags;
116};
117
118struct 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
124static 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
129static inline bool
130lowpan_iphc_ctx_is_compression(const struct lowpan_iphc_ctx *ctx)
131{
132 return test_bit(LOWPAN_IPHC_CTX_FLAG_COMPRESSION, &ctx->flags);
133}
134
135struct 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[0] __aligned(sizeof(void *));
142};
143
144static inline
145struct lowpan_dev *lowpan_dev(const struct net_device *dev)
146{
147 return netdev_priv(dev);
148}
149
150/* private device info */
151struct lowpan_802154_dev {
152 struct net_device *wdev; /* wpan device ptr */
153 u16 fragment_tag;
154};
155
156static inline struct
157lowpan_802154_dev *lowpan_802154_dev(const struct net_device *dev)
158{
159 return (struct lowpan_802154_dev *)lowpan_dev(dev)->priv;
160}
161
162struct lowpan_802154_cb {
163 u16 d_tag;
164 unsigned int d_size;
165 u8 d_offset;
166};
167
168static inline
169struct lowpan_802154_cb *lowpan_802154_cb(const struct sk_buff *skb)
170{
171 BUILD_BUG_ON(sizeof(struct lowpan_802154_cb) > sizeof(skb->cb));
172 return (struct lowpan_802154_cb *)skb->cb;
173}
174
175static inline void lowpan_iphc_uncompress_eui64_lladdr(struct in6_addr *ipaddr,
176 const void *lladdr)
177{
178 /* fe:80::XXXX:XXXX:XXXX:XXXX
179 * \_________________/
180 * hwaddr
181 */
182 ipaddr->s6_addr[0] = 0xFE;
183 ipaddr->s6_addr[1] = 0x80;
184 memcpy(&ipaddr->s6_addr[8], lladdr, EUI64_ADDR_LEN);
185 /* second bit-flip (Universe/Local)
186 * is done according RFC2464
187 */
188 ipaddr->s6_addr[8] ^= 0x02;
189}
190
191#ifdef DEBUG
192/* print data in line */
193static inline void raw_dump_inline(const char *caller, char *msg,
194 const unsigned char *buf, int len)
195{
196 if (msg)
197 pr_debug("%s():%s: ", caller, msg);
198
199 print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
200}
201
202/* print data in a table format:
203 *
204 * addr: xx xx xx xx xx xx
205 * addr: xx xx xx xx xx xx
206 * ...
207 */
208static inline void raw_dump_table(const char *caller, char *msg,
209 const unsigned char *buf, int len)
210{
211 if (msg)
212 pr_debug("%s():%s:\n", caller, msg);
213
214 print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
215}
216#else
217static inline void raw_dump_table(const char *caller, char *msg,
218 const unsigned char *buf, int len) { }
219static inline void raw_dump_inline(const char *caller, char *msg,
220 const unsigned char *buf, int len) { }
221#endif
222
223/**
224 * lowpan_fetch_skb - getting inline data from 6LoWPAN header
225 *
226 * This function will pull data from sk buffer and put it into data to
227 * remove the 6LoWPAN inline data. This function returns true if the
228 * sk buffer is too small to pull the amount of data which is specified
229 * by len.
230 *
231 * @skb: the buffer where the inline data should be pulled from.
232 * @data: destination buffer for the inline data.
233 * @len: amount of data which should be pulled in bytes.
234 */
235static inline bool lowpan_fetch_skb(struct sk_buff *skb, void *data,
236 unsigned int len)
237{
238 if (unlikely(!pskb_may_pull(skb, len)))
239 return true;
240
241 skb_copy_from_linear_data(skb, data, len);
242 skb_pull(skb, len);
243
244 return false;
245}
246
247static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
248 const size_t len)
249{
250 memcpy(*hc_ptr, data, len);
251 *hc_ptr += len;
252}
253
254int lowpan_register_netdevice(struct net_device *dev,
255 enum lowpan_lltypes lltype);
256int lowpan_register_netdev(struct net_device *dev,
257 enum lowpan_lltypes lltype);
258void lowpan_unregister_netdevice(struct net_device *dev);
259void lowpan_unregister_netdev(struct net_device *dev);
260
261/**
262 * lowpan_header_decompress - replace 6LoWPAN header with IPv6 header
263 *
264 * This function replaces the IPHC 6LoWPAN header which should be pointed at
265 * skb->data and skb_network_header, with the IPv6 header.
266 * It would be nice that the caller have the necessary headroom of IPv6 header
267 * and greatest Transport layer header, this would reduce the overhead for
268 * reallocate headroom.
269 *
270 * @skb: the buffer which should be manipulate.
271 * @dev: the lowpan net device pointer.
272 * @daddr: destination lladdr of mac header which is used for compression
273 * methods.
274 * @saddr: source lladdr of mac header which is used for compression
275 * methods.
276 */
277int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
278 const void *daddr, const void *saddr);
279
280/**
281 * lowpan_header_compress - replace IPv6 header with 6LoWPAN header
282 *
283 * This function replaces the IPv6 header which should be pointed at
284 * skb->data and skb_network_header, with the IPHC 6LoWPAN header.
285 * The caller need to be sure that the sk buffer is not shared and at have
286 * at least a headroom which is smaller or equal LOWPAN_IPHC_MAX_HEADER_LEN,
287 * which is the IPHC "more bytes than IPv6 header" at worst case.
288 *
289 * @skb: the buffer which should be manipulate.
290 * @dev: the lowpan net device pointer.
291 * @daddr: destination lladdr of mac header which is used for compression
292 * methods.
293 * @saddr: source lladdr of mac header which is used for compression
294 * methods.
295 */
296int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
297 const void *daddr, const void *saddr);
298
299#endif /* __6LOWPAN_H__ */