blob: 78c8a495b57174565aaeda4e6a626b16bb82c240 [file] [log] [blame]
Jukka Rissanen8df8c562013-12-11 17:05:34 +02001/*
2 * Copyright 2011, Siemens AG
3 * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
4 */
5
Varka Bhadram4710d802014-07-02 09:01:09 +05306/* Based on patches from Jon Smirl <jonsmirl@gmail.com>
Jukka Rissanen8df8c562013-12-11 17:05:34 +02007 * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
Jukka Rissanen8df8c562013-12-11 17:05:34 +020018 */
19
20/* Jon's code is based on 6lowpan implementation for Contiki which is:
21 * Copyright (c) 2008, Swedish Institute of Computer Science.
22 * All rights reserved.
23 *
24 * Redistribution and use in source and binary forms, with or without
25 * modification, are permitted provided that the following conditions
26 * are met:
27 * 1. Redistributions of source code must retain the above copyright
28 * notice, this list of conditions and the following disclaimer.
29 * 2. Redistributions in binary form must reproduce the above copyright
30 * notice, this list of conditions and the following disclaimer in the
31 * documentation and/or other materials provided with the distribution.
32 * 3. Neither the name of the Institute nor the names of its contributors
33 * may be used to endorse or promote products derived from this software
34 * without specific prior written permission.
35 *
36 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
37 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
39 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
40 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
41 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
42 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
44 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
45 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
46 * SUCH DAMAGE.
47 */
48
49#include <linux/bitops.h>
50#include <linux/if_arp.h>
51#include <linux/netdevice.h>
Alexander Aringcefc8c82014-03-05 14:29:05 +010052#include <net/6lowpan.h>
Jukka Rissanen8df8c562013-12-11 17:05:34 +020053#include <net/ipv6.h>
54#include <net/af_ieee802154.h>
55
Alexander Aringcc6ed262015-01-09 16:42:58 +010056#include "nhc.h"
57
Varka Bhadram4710d802014-07-02 09:01:09 +053058/* Uncompress address function for source and
Jukka Rissanen8df8c562013-12-11 17:05:34 +020059 * destination address(non-multicast).
60 *
61 * address_mode is sam value or dam value.
62 */
63static int uncompress_addr(struct sk_buff *skb,
Varka Bhadram4710d802014-07-02 09:01:09 +053064 struct in6_addr *ipaddr, const u8 address_mode,
65 const u8 *lladdr, const u8 addr_type,
66 const u8 addr_len)
Jukka Rissanen8df8c562013-12-11 17:05:34 +020067{
68 bool fail;
69
70 switch (address_mode) {
71 case LOWPAN_IPHC_ADDR_00:
72 /* for global link addresses */
73 fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
74 break;
75 case LOWPAN_IPHC_ADDR_01:
76 /* fe:80::XXXX:XXXX:XXXX:XXXX */
77 ipaddr->s6_addr[0] = 0xFE;
78 ipaddr->s6_addr[1] = 0x80;
79 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[8], 8);
80 break;
81 case LOWPAN_IPHC_ADDR_02:
82 /* fe:80::ff:fe00:XXXX */
83 ipaddr->s6_addr[0] = 0xFE;
84 ipaddr->s6_addr[1] = 0x80;
85 ipaddr->s6_addr[11] = 0xFF;
86 ipaddr->s6_addr[12] = 0xFE;
87 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2);
88 break;
89 case LOWPAN_IPHC_ADDR_03:
90 fail = false;
91 switch (addr_type) {
92 case IEEE802154_ADDR_LONG:
93 /* fe:80::XXXX:XXXX:XXXX:XXXX
94 * \_________________/
95 * hwaddr
96 */
97 ipaddr->s6_addr[0] = 0xFE;
98 ipaddr->s6_addr[1] = 0x80;
99 memcpy(&ipaddr->s6_addr[8], lladdr, addr_len);
100 /* second bit-flip (Universe/Local)
101 * is done according RFC2464
102 */
103 ipaddr->s6_addr[8] ^= 0x02;
104 break;
105 case IEEE802154_ADDR_SHORT:
106 /* fe:80::ff:fe00:XXXX
107 * \__/
108 * short_addr
109 *
110 * Universe/Local bit is zero.
111 */
112 ipaddr->s6_addr[0] = 0xFE;
113 ipaddr->s6_addr[1] = 0x80;
114 ipaddr->s6_addr[11] = 0xFF;
115 ipaddr->s6_addr[12] = 0xFE;
116 ipaddr->s6_addr16[7] = htons(*((u16 *)lladdr));
117 break;
118 default:
119 pr_debug("Invalid addr_type set\n");
120 return -EINVAL;
121 }
122 break;
123 default:
124 pr_debug("Invalid address mode value: 0x%x\n", address_mode);
125 return -EINVAL;
126 }
127
128 if (fail) {
129 pr_debug("Failed to fetch skb data\n");
130 return -EIO;
131 }
132
133 raw_dump_inline(NULL, "Reconstructed ipv6 addr is",
134 ipaddr->s6_addr, 16);
135
136 return 0;
137}
138
Varka Bhadram4710d802014-07-02 09:01:09 +0530139/* Uncompress address function for source context
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200140 * based address(non-multicast).
141 */
142static int uncompress_context_based_src_addr(struct sk_buff *skb,
Varka Bhadram4710d802014-07-02 09:01:09 +0530143 struct in6_addr *ipaddr,
144 const u8 sam)
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200145{
146 switch (sam) {
147 case LOWPAN_IPHC_ADDR_00:
148 /* unspec address ::
149 * Do nothing, address is already ::
150 */
151 break;
152 case LOWPAN_IPHC_ADDR_01:
153 /* TODO */
154 case LOWPAN_IPHC_ADDR_02:
155 /* TODO */
156 case LOWPAN_IPHC_ADDR_03:
157 /* TODO */
158 netdev_warn(skb->dev, "SAM value 0x%x not supported\n", sam);
159 return -EINVAL;
160 default:
161 pr_debug("Invalid sam value: 0x%x\n", sam);
162 return -EINVAL;
163 }
164
165 raw_dump_inline(NULL,
166 "Reconstructed context based ipv6 src addr is",
167 ipaddr->s6_addr, 16);
168
169 return 0;
170}
171
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200172/* Uncompress function for multicast destination address,
173 * when M bit is set.
174 */
Marcel Holtmann7fc4cfd2014-07-30 03:48:41 +0200175static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb,
176 struct in6_addr *ipaddr,
177 const u8 dam)
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200178{
179 bool fail;
180
181 switch (dam) {
182 case LOWPAN_IPHC_DAM_00:
183 /* 00: 128 bits. The full address
184 * is carried in-line.
185 */
186 fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
187 break;
188 case LOWPAN_IPHC_DAM_01:
189 /* 01: 48 bits. The address takes
190 * the form ffXX::00XX:XXXX:XXXX.
191 */
192 ipaddr->s6_addr[0] = 0xFF;
193 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
194 fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[11], 5);
195 break;
196 case LOWPAN_IPHC_DAM_10:
197 /* 10: 32 bits. The address takes
198 * the form ffXX::00XX:XXXX.
199 */
200 ipaddr->s6_addr[0] = 0xFF;
201 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
202 fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[13], 3);
203 break;
204 case LOWPAN_IPHC_DAM_11:
205 /* 11: 8 bits. The address takes
206 * the form ff02::00XX.
207 */
208 ipaddr->s6_addr[0] = 0xFF;
209 ipaddr->s6_addr[1] = 0x02;
210 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[15], 1);
211 break;
212 default:
213 pr_debug("DAM value has a wrong value: 0x%x\n", dam);
214 return -EINVAL;
215 }
216
217 if (fail) {
218 pr_debug("Failed to fetch skb data\n");
219 return -EIO;
220 }
221
222 raw_dump_inline(NULL, "Reconstructed ipv6 multicast addr is",
Marcel Holtmann7fc4cfd2014-07-30 03:48:41 +0200223 ipaddr->s6_addr, 16);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200224
225 return 0;
226}
227
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200228/* TTL uncompression values */
229static const u8 lowpan_ttl_values[] = { 0, 1, 64, 255 };
230
Martin Townsend01141232014-10-23 15:40:56 +0100231int
232lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
233 const u8 *saddr, const u8 saddr_type,
234 const u8 saddr_len, const u8 *daddr,
235 const u8 daddr_type, const u8 daddr_len,
236 u8 iphc0, u8 iphc1)
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200237{
238 struct ipv6hdr hdr = {};
239 u8 tmp, num_context = 0;
240 int err;
241
242 raw_dump_table(__func__, "raw skb data dump uncompressed",
Varka Bhadram4710d802014-07-02 09:01:09 +0530243 skb->data, skb->len);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200244
245 /* another if the CID flag is set */
246 if (iphc1 & LOWPAN_IPHC_CID) {
247 pr_debug("CID flag is set, increase header with one\n");
Alexander Aring4ebc9602014-07-29 23:47:00 +0200248 if (lowpan_fetch_skb(skb, &num_context, sizeof(num_context)))
Martin Townsend56b2c3e2014-11-06 19:15:13 +0000249 return -EINVAL;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200250 }
251
252 hdr.version = 6;
253
254 /* Traffic Class and Flow Label */
255 switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
Varka Bhadram4710d802014-07-02 09:01:09 +0530256 /* Traffic Class and FLow Label carried in-line
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200257 * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
258 */
259 case 0: /* 00b */
Alexander Aring4ebc9602014-07-29 23:47:00 +0200260 if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
Martin Townsend56b2c3e2014-11-06 19:15:13 +0000261 return -EINVAL;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200262
263 memcpy(&hdr.flow_lbl, &skb->data[0], 3);
264 skb_pull(skb, 3);
265 hdr.priority = ((tmp >> 2) & 0x0f);
266 hdr.flow_lbl[0] = ((tmp >> 2) & 0x30) | (tmp << 6) |
267 (hdr.flow_lbl[0] & 0x0f);
268 break;
Varka Bhadram4710d802014-07-02 09:01:09 +0530269 /* Traffic class carried in-line
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200270 * ECN + DSCP (1 byte), Flow Label is elided
271 */
272 case 2: /* 10b */
Alexander Aring4ebc9602014-07-29 23:47:00 +0200273 if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
Martin Townsend56b2c3e2014-11-06 19:15:13 +0000274 return -EINVAL;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200275
276 hdr.priority = ((tmp >> 2) & 0x0f);
277 hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30);
278 break;
Varka Bhadram4710d802014-07-02 09:01:09 +0530279 /* Flow Label carried in-line
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200280 * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
281 */
282 case 1: /* 01b */
Alexander Aring4ebc9602014-07-29 23:47:00 +0200283 if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
Martin Townsend56b2c3e2014-11-06 19:15:13 +0000284 return -EINVAL;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200285
Lukasz Duda77e867b2015-08-10 21:15:52 +0200286 hdr.flow_lbl[0] = (tmp & 0x0F) | ((tmp >> 2) & 0x30);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200287 memcpy(&hdr.flow_lbl[1], &skb->data[0], 2);
288 skb_pull(skb, 2);
289 break;
290 /* Traffic Class and Flow Label are elided */
291 case 3: /* 11b */
292 break;
293 default:
294 break;
295 }
296
297 /* Next Header */
298 if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
299 /* Next header is carried inline */
Alexander Aring4ebc9602014-07-29 23:47:00 +0200300 if (lowpan_fetch_skb(skb, &hdr.nexthdr, sizeof(hdr.nexthdr)))
Martin Townsend56b2c3e2014-11-06 19:15:13 +0000301 return -EINVAL;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200302
303 pr_debug("NH flag is set, next header carried inline: %02x\n",
304 hdr.nexthdr);
305 }
306
307 /* Hop Limit */
Varka Bhadram4710d802014-07-02 09:01:09 +0530308 if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I) {
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200309 hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03];
Varka Bhadram4710d802014-07-02 09:01:09 +0530310 } else {
Alexander Aring4ebc9602014-07-29 23:47:00 +0200311 if (lowpan_fetch_skb(skb, &hdr.hop_limit,
312 sizeof(hdr.hop_limit)))
Martin Townsend56b2c3e2014-11-06 19:15:13 +0000313 return -EINVAL;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200314 }
315
316 /* Extract SAM to the tmp variable */
317 tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03;
318
319 if (iphc1 & LOWPAN_IPHC_SAC) {
320 /* Source address context based uncompression */
321 pr_debug("SAC bit is set. Handle context based source address.\n");
Marcel Holtmann7fc4cfd2014-07-30 03:48:41 +0200322 err = uncompress_context_based_src_addr(skb, &hdr.saddr, tmp);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200323 } else {
324 /* Source address uncompression */
325 pr_debug("source address stateless compression\n");
326 err = uncompress_addr(skb, &hdr.saddr, tmp, saddr,
Varka Bhadram4710d802014-07-02 09:01:09 +0530327 saddr_type, saddr_len);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200328 }
329
330 /* Check on error of previous branch */
331 if (err)
Martin Townsend56b2c3e2014-11-06 19:15:13 +0000332 return -EINVAL;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200333
334 /* Extract DAM to the tmp variable */
335 tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03;
336
337 /* check for Multicast Compression */
338 if (iphc1 & LOWPAN_IPHC_M) {
339 if (iphc1 & LOWPAN_IPHC_DAC) {
340 pr_debug("dest: context-based mcast compression\n");
341 /* TODO: implement this */
342 } else {
Marcel Holtmann7fc4cfd2014-07-30 03:48:41 +0200343 err = lowpan_uncompress_multicast_daddr(skb, &hdr.daddr,
344 tmp);
345
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200346 if (err)
Martin Townsend56b2c3e2014-11-06 19:15:13 +0000347 return -EINVAL;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200348 }
349 } else {
350 err = uncompress_addr(skb, &hdr.daddr, tmp, daddr,
Varka Bhadram4710d802014-07-02 09:01:09 +0530351 daddr_type, daddr_len);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200352 pr_debug("dest: stateless compression mode %d dest %pI6c\n",
Varka Bhadram4710d802014-07-02 09:01:09 +0530353 tmp, &hdr.daddr);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200354 if (err)
Martin Townsend56b2c3e2014-11-06 19:15:13 +0000355 return -EINVAL;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200356 }
357
Alexander Aringcc6ed262015-01-09 16:42:58 +0100358 /* Next header data uncompression */
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200359 if (iphc0 & LOWPAN_IPHC_NH_C) {
Alexander Aringcc6ed262015-01-09 16:42:58 +0100360 err = lowpan_nhc_do_uncompression(skb, dev, &hdr);
361 if (err < 0)
Martin Townsend11e3ff72014-10-13 11:00:56 +0100362 return err;
Martin Townsend11e3ff72014-10-13 11:00:56 +0100363 } else {
364 err = skb_cow(skb, sizeof(hdr));
Martin Townsend56b2c3e2014-11-06 19:15:13 +0000365 if (unlikely(err))
Martin Townsend11e3ff72014-10-13 11:00:56 +0100366 return err;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200367 }
368
Alexander Aring72a5e6b2015-09-02 14:21:25 +0200369 switch (lowpan_priv(dev)->lltype) {
370 case LOWPAN_LLTYPE_IEEE802154:
371 if (lowpan_802154_cb(skb)->d_size)
372 hdr.payload_len = htons(lowpan_802154_cb(skb)->d_size -
373 sizeof(struct ipv6hdr));
374 else
375 hdr.payload_len = htons(skb->len);
376 break;
377 default:
378 hdr.payload_len = htons(skb->len);
379 break;
380 }
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200381
382 pr_debug("skb headroom size = %d, data length = %d\n",
383 skb_headroom(skb), skb->len);
384
385 pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t"
386 "nexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n",
387 hdr.version, ntohs(hdr.payload_len), hdr.nexthdr,
388 hdr.hop_limit, &hdr.daddr);
389
Martin Townsendf8b36172014-10-23 15:40:53 +0100390 skb_push(skb, sizeof(hdr));
391 skb_reset_network_header(skb);
392 skb_copy_to_linear_data(skb, &hdr, sizeof(hdr));
393
Marcel Holtmann7fc4cfd2014-07-30 03:48:41 +0200394 raw_dump_table(__func__, "raw header dump", (u8 *)&hdr, sizeof(hdr));
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200395
Martin Townsendf8b36172014-10-23 15:40:53 +0100396 return 0;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200397}
Martin Townsend01141232014-10-23 15:40:56 +0100398EXPORT_SYMBOL_GPL(lowpan_header_decompress);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200399
Alexander Aring84ca5e02014-07-29 23:46:58 +0200400static u8 lowpan_compress_addr_64(u8 **hc_ptr, u8 shift,
Varka Bhadram4710d802014-07-02 09:01:09 +0530401 const struct in6_addr *ipaddr,
402 const unsigned char *lladdr)
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200403{
404 u8 val = 0;
405
406 if (is_addr_mac_addr_based(ipaddr, lladdr)) {
407 val = 3; /* 0-bits */
408 pr_debug("address compression 0 bits\n");
409 } else if (lowpan_is_iid_16_bit_compressable(ipaddr)) {
410 /* compress IID to 16 bits xxxx::XXXX */
Alexander Aring85c71242014-07-29 23:47:01 +0200411 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[7], 2);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200412 val = 2; /* 16-bits */
413 raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)",
Alexander Aring84ca5e02014-07-29 23:46:58 +0200414 *hc_ptr - 2, 2);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200415 } else {
416 /* do not compress IID => xxxx::IID */
Alexander Aring85c71242014-07-29 23:47:01 +0200417 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[4], 8);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200418 val = 1; /* 64-bits */
419 raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)",
Alexander Aring84ca5e02014-07-29 23:46:58 +0200420 *hc_ptr - 8, 8);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200421 }
422
423 return rol8(val, shift);
424}
425
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200426int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
Varka Bhadram4710d802014-07-02 09:01:09 +0530427 unsigned short type, const void *_daddr,
428 const void *_saddr, unsigned int len)
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200429{
Alexander Aring84ca5e02014-07-29 23:46:58 +0200430 u8 tmp, iphc0, iphc1, *hc_ptr;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200431 struct ipv6hdr *hdr;
432 u8 head[100] = {};
Alexander Aringcc6ed262015-01-09 16:42:58 +0100433 int ret, addr_type;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200434
435 if (type != ETH_P_IPV6)
436 return -EINVAL;
437
438 hdr = ipv6_hdr(skb);
Alexander Aring84ca5e02014-07-29 23:46:58 +0200439 hc_ptr = head + 2;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200440
441 pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n"
442 "\tnexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n",
Varka Bhadram4710d802014-07-02 09:01:09 +0530443 hdr->version, ntohs(hdr->payload_len), hdr->nexthdr,
444 hdr->hop_limit, &hdr->daddr);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200445
446 raw_dump_table(__func__, "raw skb network header dump",
Varka Bhadram4710d802014-07-02 09:01:09 +0530447 skb_network_header(skb), sizeof(struct ipv6hdr));
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200448
Varka Bhadram4710d802014-07-02 09:01:09 +0530449 /* As we copy some bit-length fields, in the IPHC encoding bytes,
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200450 * we sometimes use |=
451 * If the field is 0, and the current bit value in memory is 1,
452 * this does not work. We therefore reset the IPHC encoding here
453 */
454 iphc0 = LOWPAN_DISPATCH_IPHC;
455 iphc1 = 0;
456
457 /* TODO: context lookup */
458
459 raw_dump_inline(__func__, "saddr",
460 (unsigned char *)_saddr, IEEE802154_ADDR_LEN);
461 raw_dump_inline(__func__, "daddr",
462 (unsigned char *)_daddr, IEEE802154_ADDR_LEN);
463
Marcel Holtmann7fc4cfd2014-07-30 03:48:41 +0200464 raw_dump_table(__func__, "sending raw skb network uncompressed packet",
Varka Bhadram4710d802014-07-02 09:01:09 +0530465 skb->data, skb->len);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200466
Varka Bhadram4710d802014-07-02 09:01:09 +0530467 /* Traffic class, flow label
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200468 * If flow label is 0, compress it. If traffic class is 0, compress it
469 * We have to process both in the same time as the offset of traffic
470 * class depends on the presence of version and flow label
471 */
472
Alexander Aring84ca5e02014-07-29 23:46:58 +0200473 /* hc format of TC is ECN | DSCP , original one is DSCP | ECN */
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200474 tmp = (hdr->priority << 4) | (hdr->flow_lbl[0] >> 4);
475 tmp = ((tmp & 0x03) << 6) | (tmp >> 2);
476
477 if (((hdr->flow_lbl[0] & 0x0F) == 0) &&
Varka Bhadram4710d802014-07-02 09:01:09 +0530478 (hdr->flow_lbl[1] == 0) && (hdr->flow_lbl[2] == 0)) {
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200479 /* flow label can be compressed */
480 iphc0 |= LOWPAN_IPHC_FL_C;
481 if ((hdr->priority == 0) &&
Varka Bhadram4710d802014-07-02 09:01:09 +0530482 ((hdr->flow_lbl[0] & 0xF0) == 0)) {
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200483 /* compress (elide) all */
484 iphc0 |= LOWPAN_IPHC_TC_C;
485 } else {
486 /* compress only the flow label */
Alexander Aring84ca5e02014-07-29 23:46:58 +0200487 *hc_ptr = tmp;
488 hc_ptr += 1;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200489 }
490 } else {
491 /* Flow label cannot be compressed */
492 if ((hdr->priority == 0) &&
Varka Bhadram4710d802014-07-02 09:01:09 +0530493 ((hdr->flow_lbl[0] & 0xF0) == 0)) {
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200494 /* compress only traffic class */
495 iphc0 |= LOWPAN_IPHC_TC_C;
Alexander Aring84ca5e02014-07-29 23:46:58 +0200496 *hc_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F);
497 memcpy(hc_ptr + 1, &hdr->flow_lbl[1], 2);
498 hc_ptr += 3;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200499 } else {
500 /* compress nothing */
Alexander Aring84ca5e02014-07-29 23:46:58 +0200501 memcpy(hc_ptr, hdr, 4);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200502 /* replace the top byte with new ECN | DSCP format */
Alexander Aring84ca5e02014-07-29 23:46:58 +0200503 *hc_ptr = tmp;
504 hc_ptr += 4;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200505 }
506 }
507
508 /* NOTE: payload length is always compressed */
509
Alexander Aringcc6ed262015-01-09 16:42:58 +0100510 /* Check if we provide the nhc format for nexthdr and compression
511 * functionality. If not nexthdr is handled inline and not compressed.
512 */
513 ret = lowpan_nhc_check_compression(skb, hdr, &hc_ptr, &iphc0);
514 if (ret < 0)
515 return ret;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200516
Varka Bhadram4710d802014-07-02 09:01:09 +0530517 /* Hop limit
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200518 * if 1: compress, encoding is 01
519 * if 64: compress, encoding is 10
520 * if 255: compress, encoding is 11
521 * else do not compress
522 */
523 switch (hdr->hop_limit) {
524 case 1:
525 iphc0 |= LOWPAN_IPHC_TTL_1;
526 break;
527 case 64:
528 iphc0 |= LOWPAN_IPHC_TTL_64;
529 break;
530 case 255:
531 iphc0 |= LOWPAN_IPHC_TTL_255;
532 break;
533 default:
Alexander Aring85c71242014-07-29 23:47:01 +0200534 lowpan_push_hc_data(&hc_ptr, &hdr->hop_limit,
535 sizeof(hdr->hop_limit));
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200536 }
537
Alexander Aring556a5bf2014-07-29 23:47:02 +0200538 addr_type = ipv6_addr_type(&hdr->saddr);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200539 /* source address compression */
Alexander Aring556a5bf2014-07-29 23:47:02 +0200540 if (addr_type == IPV6_ADDR_ANY) {
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200541 pr_debug("source address is unspecified, setting SAC\n");
542 iphc1 |= LOWPAN_IPHC_SAC;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200543 } else {
Alexander Aring556a5bf2014-07-29 23:47:02 +0200544 if (addr_type & IPV6_ADDR_LINKLOCAL) {
545 iphc1 |= lowpan_compress_addr_64(&hc_ptr,
546 LOWPAN_IPHC_SAM_BIT,
547 &hdr->saddr, _saddr);
548 pr_debug("source address unicast link-local %pI6c iphc1 0x%02x\n",
549 &hdr->saddr, iphc1);
550 } else {
551 pr_debug("send the full source address\n");
552 lowpan_push_hc_data(&hc_ptr, hdr->saddr.s6_addr, 16);
553 }
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200554 }
555
Alexander Aring556a5bf2014-07-29 23:47:02 +0200556 addr_type = ipv6_addr_type(&hdr->daddr);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200557 /* destination address compression */
Alexander Aring556a5bf2014-07-29 23:47:02 +0200558 if (addr_type & IPV6_ADDR_MULTICAST) {
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200559 pr_debug("destination address is multicast: ");
560 iphc1 |= LOWPAN_IPHC_M;
561 if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) {
562 pr_debug("compressed to 1 octet\n");
563 iphc1 |= LOWPAN_IPHC_DAM_11;
564 /* use last byte */
Alexander Aring85c71242014-07-29 23:47:01 +0200565 lowpan_push_hc_data(&hc_ptr,
566 &hdr->daddr.s6_addr[15], 1);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200567 } else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) {
568 pr_debug("compressed to 4 octets\n");
569 iphc1 |= LOWPAN_IPHC_DAM_10;
570 /* second byte + the last three */
Alexander Aring85c71242014-07-29 23:47:01 +0200571 lowpan_push_hc_data(&hc_ptr,
572 &hdr->daddr.s6_addr[1], 1);
573 lowpan_push_hc_data(&hc_ptr,
574 &hdr->daddr.s6_addr[13], 3);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200575 } else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) {
576 pr_debug("compressed to 6 octets\n");
577 iphc1 |= LOWPAN_IPHC_DAM_01;
578 /* second byte + the last five */
Alexander Aring85c71242014-07-29 23:47:01 +0200579 lowpan_push_hc_data(&hc_ptr,
580 &hdr->daddr.s6_addr[1], 1);
581 lowpan_push_hc_data(&hc_ptr,
582 &hdr->daddr.s6_addr[11], 5);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200583 } else {
584 pr_debug("using full address\n");
585 iphc1 |= LOWPAN_IPHC_DAM_00;
Alexander Aring85c71242014-07-29 23:47:01 +0200586 lowpan_push_hc_data(&hc_ptr, hdr->daddr.s6_addr, 16);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200587 }
588 } else {
Alexander Aring556a5bf2014-07-29 23:47:02 +0200589 if (addr_type & IPV6_ADDR_LINKLOCAL) {
590 /* TODO: context lookup */
Alexander Aring84ca5e02014-07-29 23:46:58 +0200591 iphc1 |= lowpan_compress_addr_64(&hc_ptr,
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200592 LOWPAN_IPHC_DAM_BIT, &hdr->daddr, _daddr);
593 pr_debug("dest address unicast link-local %pI6c "
Marcel Holtmann7fc4cfd2014-07-30 03:48:41 +0200594 "iphc1 0x%02x\n", &hdr->daddr, iphc1);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200595 } else {
596 pr_debug("dest address unicast %pI6c\n", &hdr->daddr);
Alexander Aring85c71242014-07-29 23:47:01 +0200597 lowpan_push_hc_data(&hc_ptr, hdr->daddr.s6_addr, 16);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200598 }
599 }
600
Alexander Aringcc6ed262015-01-09 16:42:58 +0100601 /* next header compression */
602 if (iphc0 & LOWPAN_IPHC_NH_C) {
603 ret = lowpan_nhc_do_compression(skb, hdr, &hc_ptr);
604 if (ret < 0)
605 return ret;
606 }
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200607
608 head[0] = iphc0;
609 head[1] = iphc1;
610
611 skb_pull(skb, sizeof(struct ipv6hdr));
612 skb_reset_transport_header(skb);
Alexander Aring84ca5e02014-07-29 23:46:58 +0200613 memcpy(skb_push(skb, hc_ptr - head), head, hc_ptr - head);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200614 skb_reset_network_header(skb);
615
Alexander Aring84ca5e02014-07-29 23:46:58 +0200616 pr_debug("header len %d skb %u\n", (int)(hc_ptr - head), skb->len);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200617
618 raw_dump_table(__func__, "raw skb data dump compressed",
Varka Bhadram4710d802014-07-02 09:01:09 +0530619 skb->data, skb->len);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200620 return 0;
621}
622EXPORT_SYMBOL_GPL(lowpan_header_compress);