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[] __aligned(sizeof(void *));
142};
143
144struct lowpan_802154_neigh {
145 __le16 short_addr;
146};
147
148static inline
149struct lowpan_802154_neigh *lowpan_802154_neigh(void *neigh_priv)
150{
151 return neigh_priv;
152}
153
154static inline
155struct lowpan_dev *lowpan_dev(const struct net_device *dev)
156{
157 return netdev_priv(dev);
158}
159
160/* private device info */
161struct lowpan_802154_dev {
162 struct net_device *wdev; /* wpan device ptr */
163 u16 fragment_tag;
164};
165
166static inline struct
167lowpan_802154_dev *lowpan_802154_dev(const struct net_device *dev)
168{
169 return (struct lowpan_802154_dev *)lowpan_dev(dev)->priv;
170}
171
172struct lowpan_802154_cb {
173 u16 d_tag;
174 unsigned int d_size;
175 u8 d_offset;
176};
177
178static inline
179struct 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
185static 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(to: &ipaddr->s6_addr[8], from: lladdr, EUI64_ADDR_LEN);
195 /* second bit-flip (Universe/Local)
196 * is done according RFC2464
197 */
198 ipaddr->s6_addr[8] ^= 0x02;
199}
200
201static 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(to: &ipaddr->s6_addr[8], from: lladdr, len: 3);
211 ipaddr->s6_addr[11] = 0xFF;
212 ipaddr->s6_addr[12] = 0xFE;
213 memcpy(to: &ipaddr->s6_addr[13], from: lladdr + 3, len: 3);
214}
215
216#ifdef DEBUG
217/* print data in line */
218static 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 */
233static 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
242static inline void raw_dump_table(const char *caller, char *msg,
243 const unsigned char *buf, int len) { }
244static 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 */
260static 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, to: data, len);
267 skb_pull(skb, len);
268
269 return false;
270}
271
272static 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
278static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
279 const size_t len)
280{
281 memcpy(to: *hc_ptr, from: data, len);
282 *hc_ptr += len;
283}
284
285int lowpan_register_netdevice(struct net_device *dev,
286 enum lowpan_lltypes lltype);
287int lowpan_register_netdev(struct net_device *dev,
288 enum lowpan_lltypes lltype);
289void lowpan_unregister_netdevice(struct net_device *dev);
290void 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 */
308int 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 */
327int 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