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Commit | Line | Data |
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8df8c56a JR |
1 | /* |
2 | * Copyright 2011, Siemens AG | |
3 | * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com> | |
4 | */ | |
5 | ||
4710d806 | 6 | /* Based on patches from Jon Smirl <jonsmirl@gmail.com> |
8df8c56a JR |
7 | * 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 | * | |
8df8c56a JR |
18 | */ |
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> | |
5ae5e991 | 51 | #include <linux/module.h> |
8df8c56a | 52 | #include <linux/netdevice.h> |
cefc8c8a | 53 | #include <net/6lowpan.h> |
8df8c56a JR |
54 | #include <net/ipv6.h> |
55 | #include <net/af_ieee802154.h> | |
56 | ||
cc6ed268 AA |
57 | #include "nhc.h" |
58 | ||
4710d806 | 59 | /* Uncompress address function for source and |
8df8c56a JR |
60 | * destination address(non-multicast). |
61 | * | |
62 | * address_mode is sam value or dam value. | |
63 | */ | |
64 | static int uncompress_addr(struct sk_buff *skb, | |
4710d806 VB |
65 | struct in6_addr *ipaddr, const u8 address_mode, |
66 | const u8 *lladdr, const u8 addr_type, | |
67 | const u8 addr_len) | |
8df8c56a JR |
68 | { |
69 | bool fail; | |
70 | ||
71 | switch (address_mode) { | |
72 | case LOWPAN_IPHC_ADDR_00: | |
73 | /* for global link addresses */ | |
74 | fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16); | |
75 | break; | |
76 | case LOWPAN_IPHC_ADDR_01: | |
77 | /* fe:80::XXXX:XXXX:XXXX:XXXX */ | |
78 | ipaddr->s6_addr[0] = 0xFE; | |
79 | ipaddr->s6_addr[1] = 0x80; | |
80 | fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[8], 8); | |
81 | break; | |
82 | case LOWPAN_IPHC_ADDR_02: | |
83 | /* fe:80::ff:fe00:XXXX */ | |
84 | ipaddr->s6_addr[0] = 0xFE; | |
85 | ipaddr->s6_addr[1] = 0x80; | |
86 | ipaddr->s6_addr[11] = 0xFF; | |
87 | ipaddr->s6_addr[12] = 0xFE; | |
88 | fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2); | |
89 | break; | |
90 | case LOWPAN_IPHC_ADDR_03: | |
91 | fail = false; | |
92 | switch (addr_type) { | |
93 | case IEEE802154_ADDR_LONG: | |
94 | /* fe:80::XXXX:XXXX:XXXX:XXXX | |
95 | * \_________________/ | |
96 | * hwaddr | |
97 | */ | |
98 | ipaddr->s6_addr[0] = 0xFE; | |
99 | ipaddr->s6_addr[1] = 0x80; | |
100 | memcpy(&ipaddr->s6_addr[8], lladdr, addr_len); | |
101 | /* second bit-flip (Universe/Local) | |
102 | * is done according RFC2464 | |
103 | */ | |
104 | ipaddr->s6_addr[8] ^= 0x02; | |
105 | break; | |
106 | case IEEE802154_ADDR_SHORT: | |
107 | /* fe:80::ff:fe00:XXXX | |
108 | * \__/ | |
109 | * short_addr | |
110 | * | |
111 | * Universe/Local bit is zero. | |
112 | */ | |
113 | ipaddr->s6_addr[0] = 0xFE; | |
114 | ipaddr->s6_addr[1] = 0x80; | |
115 | ipaddr->s6_addr[11] = 0xFF; | |
116 | ipaddr->s6_addr[12] = 0xFE; | |
117 | ipaddr->s6_addr16[7] = htons(*((u16 *)lladdr)); | |
118 | break; | |
119 | default: | |
120 | pr_debug("Invalid addr_type set\n"); | |
121 | return -EINVAL; | |
122 | } | |
123 | break; | |
124 | default: | |
125 | pr_debug("Invalid address mode value: 0x%x\n", address_mode); | |
126 | return -EINVAL; | |
127 | } | |
128 | ||
129 | if (fail) { | |
130 | pr_debug("Failed to fetch skb data\n"); | |
131 | return -EIO; | |
132 | } | |
133 | ||
134 | raw_dump_inline(NULL, "Reconstructed ipv6 addr is", | |
135 | ipaddr->s6_addr, 16); | |
136 | ||
137 | return 0; | |
138 | } | |
139 | ||
4710d806 | 140 | /* Uncompress address function for source context |
8df8c56a JR |
141 | * based address(non-multicast). |
142 | */ | |
143 | static int uncompress_context_based_src_addr(struct sk_buff *skb, | |
4710d806 VB |
144 | struct in6_addr *ipaddr, |
145 | const u8 sam) | |
8df8c56a JR |
146 | { |
147 | switch (sam) { | |
148 | case LOWPAN_IPHC_ADDR_00: | |
149 | /* unspec address :: | |
150 | * Do nothing, address is already :: | |
151 | */ | |
152 | break; | |
153 | case LOWPAN_IPHC_ADDR_01: | |
154 | /* TODO */ | |
155 | case LOWPAN_IPHC_ADDR_02: | |
156 | /* TODO */ | |
157 | case LOWPAN_IPHC_ADDR_03: | |
158 | /* TODO */ | |
159 | netdev_warn(skb->dev, "SAM value 0x%x not supported\n", sam); | |
160 | return -EINVAL; | |
161 | default: | |
162 | pr_debug("Invalid sam value: 0x%x\n", sam); | |
163 | return -EINVAL; | |
164 | } | |
165 | ||
166 | raw_dump_inline(NULL, | |
167 | "Reconstructed context based ipv6 src addr is", | |
168 | ipaddr->s6_addr, 16); | |
169 | ||
170 | return 0; | |
171 | } | |
172 | ||
8df8c56a JR |
173 | /* Uncompress function for multicast destination address, |
174 | * when M bit is set. | |
175 | */ | |
7fc4cfda MH |
176 | static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb, |
177 | struct in6_addr *ipaddr, | |
178 | const u8 dam) | |
8df8c56a JR |
179 | { |
180 | bool fail; | |
181 | ||
182 | switch (dam) { | |
183 | case LOWPAN_IPHC_DAM_00: | |
184 | /* 00: 128 bits. The full address | |
185 | * is carried in-line. | |
186 | */ | |
187 | fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16); | |
188 | break; | |
189 | case LOWPAN_IPHC_DAM_01: | |
190 | /* 01: 48 bits. The address takes | |
191 | * the form ffXX::00XX:XXXX:XXXX. | |
192 | */ | |
193 | ipaddr->s6_addr[0] = 0xFF; | |
194 | fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1); | |
195 | fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[11], 5); | |
196 | break; | |
197 | case LOWPAN_IPHC_DAM_10: | |
198 | /* 10: 32 bits. The address takes | |
199 | * the form ffXX::00XX:XXXX. | |
200 | */ | |
201 | ipaddr->s6_addr[0] = 0xFF; | |
202 | fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1); | |
203 | fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[13], 3); | |
204 | break; | |
205 | case LOWPAN_IPHC_DAM_11: | |
206 | /* 11: 8 bits. The address takes | |
207 | * the form ff02::00XX. | |
208 | */ | |
209 | ipaddr->s6_addr[0] = 0xFF; | |
210 | ipaddr->s6_addr[1] = 0x02; | |
211 | fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[15], 1); | |
212 | break; | |
213 | default: | |
214 | pr_debug("DAM value has a wrong value: 0x%x\n", dam); | |
215 | return -EINVAL; | |
216 | } | |
217 | ||
218 | if (fail) { | |
219 | pr_debug("Failed to fetch skb data\n"); | |
220 | return -EIO; | |
221 | } | |
222 | ||
223 | raw_dump_inline(NULL, "Reconstructed ipv6 multicast addr is", | |
7fc4cfda | 224 | ipaddr->s6_addr, 16); |
8df8c56a JR |
225 | |
226 | return 0; | |
227 | } | |
228 | ||
8df8c56a JR |
229 | /* TTL uncompression values */ |
230 | static const u8 lowpan_ttl_values[] = { 0, 1, 64, 255 }; | |
231 | ||
01141234 MT |
232 | int |
233 | lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev, | |
234 | const u8 *saddr, const u8 saddr_type, | |
235 | const u8 saddr_len, const u8 *daddr, | |
236 | const u8 daddr_type, const u8 daddr_len, | |
237 | u8 iphc0, u8 iphc1) | |
8df8c56a JR |
238 | { |
239 | struct ipv6hdr hdr = {}; | |
240 | u8 tmp, num_context = 0; | |
241 | int err; | |
242 | ||
243 | raw_dump_table(__func__, "raw skb data dump uncompressed", | |
4710d806 | 244 | skb->data, skb->len); |
8df8c56a JR |
245 | |
246 | /* another if the CID flag is set */ | |
247 | if (iphc1 & LOWPAN_IPHC_CID) { | |
248 | pr_debug("CID flag is set, increase header with one\n"); | |
4ebc960f | 249 | if (lowpan_fetch_skb(skb, &num_context, sizeof(num_context))) |
56b2c3ee | 250 | return -EINVAL; |
8df8c56a JR |
251 | } |
252 | ||
253 | hdr.version = 6; | |
254 | ||
255 | /* Traffic Class and Flow Label */ | |
256 | switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) { | |
4710d806 | 257 | /* Traffic Class and FLow Label carried in-line |
8df8c56a JR |
258 | * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes) |
259 | */ | |
260 | case 0: /* 00b */ | |
4ebc960f | 261 | if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp))) |
56b2c3ee | 262 | return -EINVAL; |
8df8c56a JR |
263 | |
264 | memcpy(&hdr.flow_lbl, &skb->data[0], 3); | |
265 | skb_pull(skb, 3); | |
266 | hdr.priority = ((tmp >> 2) & 0x0f); | |
267 | hdr.flow_lbl[0] = ((tmp >> 2) & 0x30) | (tmp << 6) | | |
268 | (hdr.flow_lbl[0] & 0x0f); | |
269 | break; | |
4710d806 | 270 | /* Traffic class carried in-line |
8df8c56a JR |
271 | * ECN + DSCP (1 byte), Flow Label is elided |
272 | */ | |
273 | case 2: /* 10b */ | |
4ebc960f | 274 | if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp))) |
56b2c3ee | 275 | return -EINVAL; |
8df8c56a JR |
276 | |
277 | hdr.priority = ((tmp >> 2) & 0x0f); | |
278 | hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30); | |
279 | break; | |
4710d806 | 280 | /* Flow Label carried in-line |
8df8c56a JR |
281 | * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided |
282 | */ | |
283 | case 1: /* 01b */ | |
4ebc960f | 284 | if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp))) |
56b2c3ee | 285 | return -EINVAL; |
8df8c56a JR |
286 | |
287 | hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30); | |
288 | memcpy(&hdr.flow_lbl[1], &skb->data[0], 2); | |
289 | skb_pull(skb, 2); | |
290 | break; | |
291 | /* Traffic Class and Flow Label are elided */ | |
292 | case 3: /* 11b */ | |
293 | break; | |
294 | default: | |
295 | break; | |
296 | } | |
297 | ||
298 | /* Next Header */ | |
299 | if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) { | |
300 | /* Next header is carried inline */ | |
4ebc960f | 301 | if (lowpan_fetch_skb(skb, &hdr.nexthdr, sizeof(hdr.nexthdr))) |
56b2c3ee | 302 | return -EINVAL; |
8df8c56a JR |
303 | |
304 | pr_debug("NH flag is set, next header carried inline: %02x\n", | |
305 | hdr.nexthdr); | |
306 | } | |
307 | ||
308 | /* Hop Limit */ | |
4710d806 | 309 | if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I) { |
8df8c56a | 310 | hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03]; |
4710d806 | 311 | } else { |
4ebc960f AA |
312 | if (lowpan_fetch_skb(skb, &hdr.hop_limit, |
313 | sizeof(hdr.hop_limit))) | |
56b2c3ee | 314 | return -EINVAL; |
8df8c56a JR |
315 | } |
316 | ||
317 | /* Extract SAM to the tmp variable */ | |
318 | tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03; | |
319 | ||
320 | if (iphc1 & LOWPAN_IPHC_SAC) { | |
321 | /* Source address context based uncompression */ | |
322 | pr_debug("SAC bit is set. Handle context based source address.\n"); | |
7fc4cfda | 323 | err = uncompress_context_based_src_addr(skb, &hdr.saddr, tmp); |
8df8c56a JR |
324 | } else { |
325 | /* Source address uncompression */ | |
326 | pr_debug("source address stateless compression\n"); | |
327 | err = uncompress_addr(skb, &hdr.saddr, tmp, saddr, | |
4710d806 | 328 | saddr_type, saddr_len); |
8df8c56a JR |
329 | } |
330 | ||
331 | /* Check on error of previous branch */ | |
332 | if (err) | |
56b2c3ee | 333 | return -EINVAL; |
8df8c56a JR |
334 | |
335 | /* Extract DAM to the tmp variable */ | |
336 | tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03; | |
337 | ||
338 | /* check for Multicast Compression */ | |
339 | if (iphc1 & LOWPAN_IPHC_M) { | |
340 | if (iphc1 & LOWPAN_IPHC_DAC) { | |
341 | pr_debug("dest: context-based mcast compression\n"); | |
342 | /* TODO: implement this */ | |
343 | } else { | |
7fc4cfda MH |
344 | err = lowpan_uncompress_multicast_daddr(skb, &hdr.daddr, |
345 | tmp); | |
346 | ||
8df8c56a | 347 | if (err) |
56b2c3ee | 348 | return -EINVAL; |
8df8c56a JR |
349 | } |
350 | } else { | |
351 | err = uncompress_addr(skb, &hdr.daddr, tmp, daddr, | |
4710d806 | 352 | daddr_type, daddr_len); |
8df8c56a | 353 | pr_debug("dest: stateless compression mode %d dest %pI6c\n", |
4710d806 | 354 | tmp, &hdr.daddr); |
8df8c56a | 355 | if (err) |
56b2c3ee | 356 | return -EINVAL; |
8df8c56a JR |
357 | } |
358 | ||
cc6ed268 | 359 | /* Next header data uncompression */ |
8df8c56a | 360 | if (iphc0 & LOWPAN_IPHC_NH_C) { |
cc6ed268 AA |
361 | err = lowpan_nhc_do_uncompression(skb, dev, &hdr); |
362 | if (err < 0) | |
11e3ff70 | 363 | return err; |
11e3ff70 MT |
364 | } else { |
365 | err = skb_cow(skb, sizeof(hdr)); | |
56b2c3ee | 366 | if (unlikely(err)) |
11e3ff70 | 367 | return err; |
8df8c56a JR |
368 | } |
369 | ||
370 | hdr.payload_len = htons(skb->len); | |
371 | ||
372 | pr_debug("skb headroom size = %d, data length = %d\n", | |
373 | skb_headroom(skb), skb->len); | |
374 | ||
375 | pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t" | |
376 | "nexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n", | |
377 | hdr.version, ntohs(hdr.payload_len), hdr.nexthdr, | |
378 | hdr.hop_limit, &hdr.daddr); | |
379 | ||
f8b36176 MT |
380 | skb_push(skb, sizeof(hdr)); |
381 | skb_reset_network_header(skb); | |
382 | skb_copy_to_linear_data(skb, &hdr, sizeof(hdr)); | |
8df8c56a | 383 | |
f8b36176 | 384 | raw_dump_table(__func__, "raw header dump", (u8 *)&hdr, sizeof(hdr)); |
8df8c56a | 385 | |
f8b36176 | 386 | return 0; |
8df8c56a | 387 | } |
01141234 | 388 | EXPORT_SYMBOL_GPL(lowpan_header_decompress); |
8df8c56a | 389 | |
84ca5e03 | 390 | static u8 lowpan_compress_addr_64(u8 **hc_ptr, u8 shift, |
4710d806 VB |
391 | const struct in6_addr *ipaddr, |
392 | const unsigned char *lladdr) | |
8df8c56a JR |
393 | { |
394 | u8 val = 0; | |
395 | ||
396 | if (is_addr_mac_addr_based(ipaddr, lladdr)) { | |
397 | val = 3; /* 0-bits */ | |
398 | pr_debug("address compression 0 bits\n"); | |
399 | } else if (lowpan_is_iid_16_bit_compressable(ipaddr)) { | |
400 | /* compress IID to 16 bits xxxx::XXXX */ | |
85c71240 | 401 | lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[7], 2); |
8df8c56a JR |
402 | val = 2; /* 16-bits */ |
403 | raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)", | |
84ca5e03 | 404 | *hc_ptr - 2, 2); |
8df8c56a JR |
405 | } else { |
406 | /* do not compress IID => xxxx::IID */ | |
85c71240 | 407 | lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[4], 8); |
8df8c56a JR |
408 | val = 1; /* 64-bits */ |
409 | raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)", | |
84ca5e03 | 410 | *hc_ptr - 8, 8); |
8df8c56a JR |
411 | } |
412 | ||
413 | return rol8(val, shift); | |
414 | } | |
415 | ||
8df8c56a | 416 | int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev, |
4710d806 VB |
417 | unsigned short type, const void *_daddr, |
418 | const void *_saddr, unsigned int len) | |
8df8c56a | 419 | { |
84ca5e03 | 420 | u8 tmp, iphc0, iphc1, *hc_ptr; |
8df8c56a JR |
421 | struct ipv6hdr *hdr; |
422 | u8 head[100] = {}; | |
cc6ed268 | 423 | int ret, addr_type; |
8df8c56a JR |
424 | |
425 | if (type != ETH_P_IPV6) | |
426 | return -EINVAL; | |
427 | ||
428 | hdr = ipv6_hdr(skb); | |
84ca5e03 | 429 | hc_ptr = head + 2; |
8df8c56a JR |
430 | |
431 | pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n" | |
432 | "\tnexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n", | |
4710d806 VB |
433 | hdr->version, ntohs(hdr->payload_len), hdr->nexthdr, |
434 | hdr->hop_limit, &hdr->daddr); | |
8df8c56a JR |
435 | |
436 | raw_dump_table(__func__, "raw skb network header dump", | |
4710d806 | 437 | skb_network_header(skb), sizeof(struct ipv6hdr)); |
8df8c56a | 438 | |
4710d806 | 439 | /* As we copy some bit-length fields, in the IPHC encoding bytes, |
8df8c56a JR |
440 | * we sometimes use |= |
441 | * If the field is 0, and the current bit value in memory is 1, | |
442 | * this does not work. We therefore reset the IPHC encoding here | |
443 | */ | |
444 | iphc0 = LOWPAN_DISPATCH_IPHC; | |
445 | iphc1 = 0; | |
446 | ||
447 | /* TODO: context lookup */ | |
448 | ||
449 | raw_dump_inline(__func__, "saddr", | |
450 | (unsigned char *)_saddr, IEEE802154_ADDR_LEN); | |
451 | raw_dump_inline(__func__, "daddr", | |
452 | (unsigned char *)_daddr, IEEE802154_ADDR_LEN); | |
453 | ||
7fc4cfda | 454 | raw_dump_table(__func__, "sending raw skb network uncompressed packet", |
4710d806 | 455 | skb->data, skb->len); |
8df8c56a | 456 | |
4710d806 | 457 | /* Traffic class, flow label |
8df8c56a JR |
458 | * If flow label is 0, compress it. If traffic class is 0, compress it |
459 | * We have to process both in the same time as the offset of traffic | |
460 | * class depends on the presence of version and flow label | |
461 | */ | |
462 | ||
84ca5e03 | 463 | /* hc format of TC is ECN | DSCP , original one is DSCP | ECN */ |
8df8c56a JR |
464 | tmp = (hdr->priority << 4) | (hdr->flow_lbl[0] >> 4); |
465 | tmp = ((tmp & 0x03) << 6) | (tmp >> 2); | |
466 | ||
467 | if (((hdr->flow_lbl[0] & 0x0F) == 0) && | |
4710d806 | 468 | (hdr->flow_lbl[1] == 0) && (hdr->flow_lbl[2] == 0)) { |
8df8c56a JR |
469 | /* flow label can be compressed */ |
470 | iphc0 |= LOWPAN_IPHC_FL_C; | |
471 | if ((hdr->priority == 0) && | |
4710d806 | 472 | ((hdr->flow_lbl[0] & 0xF0) == 0)) { |
8df8c56a JR |
473 | /* compress (elide) all */ |
474 | iphc0 |= LOWPAN_IPHC_TC_C; | |
475 | } else { | |
476 | /* compress only the flow label */ | |
84ca5e03 AA |
477 | *hc_ptr = tmp; |
478 | hc_ptr += 1; | |
8df8c56a JR |
479 | } |
480 | } else { | |
481 | /* Flow label cannot be compressed */ | |
482 | if ((hdr->priority == 0) && | |
4710d806 | 483 | ((hdr->flow_lbl[0] & 0xF0) == 0)) { |
8df8c56a JR |
484 | /* compress only traffic class */ |
485 | iphc0 |= LOWPAN_IPHC_TC_C; | |
84ca5e03 AA |
486 | *hc_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F); |
487 | memcpy(hc_ptr + 1, &hdr->flow_lbl[1], 2); | |
488 | hc_ptr += 3; | |
8df8c56a JR |
489 | } else { |
490 | /* compress nothing */ | |
84ca5e03 | 491 | memcpy(hc_ptr, hdr, 4); |
8df8c56a | 492 | /* replace the top byte with new ECN | DSCP format */ |
84ca5e03 AA |
493 | *hc_ptr = tmp; |
494 | hc_ptr += 4; | |
8df8c56a JR |
495 | } |
496 | } | |
497 | ||
498 | /* NOTE: payload length is always compressed */ | |
499 | ||
cc6ed268 AA |
500 | /* Check if we provide the nhc format for nexthdr and compression |
501 | * functionality. If not nexthdr is handled inline and not compressed. | |
502 | */ | |
503 | ret = lowpan_nhc_check_compression(skb, hdr, &hc_ptr, &iphc0); | |
504 | if (ret < 0) | |
505 | return ret; | |
8df8c56a | 506 | |
4710d806 | 507 | /* Hop limit |
8df8c56a JR |
508 | * if 1: compress, encoding is 01 |
509 | * if 64: compress, encoding is 10 | |
510 | * if 255: compress, encoding is 11 | |
511 | * else do not compress | |
512 | */ | |
513 | switch (hdr->hop_limit) { | |
514 | case 1: | |
515 | iphc0 |= LOWPAN_IPHC_TTL_1; | |
516 | break; | |
517 | case 64: | |
518 | iphc0 |= LOWPAN_IPHC_TTL_64; | |
519 | break; | |
520 | case 255: | |
521 | iphc0 |= LOWPAN_IPHC_TTL_255; | |
522 | break; | |
523 | default: | |
85c71240 AA |
524 | lowpan_push_hc_data(&hc_ptr, &hdr->hop_limit, |
525 | sizeof(hdr->hop_limit)); | |
8df8c56a JR |
526 | } |
527 | ||
556a5bfc | 528 | addr_type = ipv6_addr_type(&hdr->saddr); |
8df8c56a | 529 | /* source address compression */ |
556a5bfc | 530 | if (addr_type == IPV6_ADDR_ANY) { |
8df8c56a JR |
531 | pr_debug("source address is unspecified, setting SAC\n"); |
532 | iphc1 |= LOWPAN_IPHC_SAC; | |
8df8c56a | 533 | } else { |
556a5bfc AA |
534 | if (addr_type & IPV6_ADDR_LINKLOCAL) { |
535 | iphc1 |= lowpan_compress_addr_64(&hc_ptr, | |
536 | LOWPAN_IPHC_SAM_BIT, | |
537 | &hdr->saddr, _saddr); | |
538 | pr_debug("source address unicast link-local %pI6c iphc1 0x%02x\n", | |
539 | &hdr->saddr, iphc1); | |
540 | } else { | |
541 | pr_debug("send the full source address\n"); | |
542 | lowpan_push_hc_data(&hc_ptr, hdr->saddr.s6_addr, 16); | |
543 | } | |
8df8c56a JR |
544 | } |
545 | ||
556a5bfc | 546 | addr_type = ipv6_addr_type(&hdr->daddr); |
8df8c56a | 547 | /* destination address compression */ |
556a5bfc | 548 | if (addr_type & IPV6_ADDR_MULTICAST) { |
8df8c56a JR |
549 | pr_debug("destination address is multicast: "); |
550 | iphc1 |= LOWPAN_IPHC_M; | |
551 | if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) { | |
552 | pr_debug("compressed to 1 octet\n"); | |
553 | iphc1 |= LOWPAN_IPHC_DAM_11; | |
554 | /* use last byte */ | |
85c71240 AA |
555 | lowpan_push_hc_data(&hc_ptr, |
556 | &hdr->daddr.s6_addr[15], 1); | |
8df8c56a JR |
557 | } else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) { |
558 | pr_debug("compressed to 4 octets\n"); | |
559 | iphc1 |= LOWPAN_IPHC_DAM_10; | |
560 | /* second byte + the last three */ | |
85c71240 AA |
561 | lowpan_push_hc_data(&hc_ptr, |
562 | &hdr->daddr.s6_addr[1], 1); | |
563 | lowpan_push_hc_data(&hc_ptr, | |
564 | &hdr->daddr.s6_addr[13], 3); | |
8df8c56a JR |
565 | } else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) { |
566 | pr_debug("compressed to 6 octets\n"); | |
567 | iphc1 |= LOWPAN_IPHC_DAM_01; | |
568 | /* second byte + the last five */ | |
85c71240 AA |
569 | lowpan_push_hc_data(&hc_ptr, |
570 | &hdr->daddr.s6_addr[1], 1); | |
571 | lowpan_push_hc_data(&hc_ptr, | |
572 | &hdr->daddr.s6_addr[11], 5); | |
8df8c56a JR |
573 | } else { |
574 | pr_debug("using full address\n"); | |
575 | iphc1 |= LOWPAN_IPHC_DAM_00; | |
85c71240 | 576 | lowpan_push_hc_data(&hc_ptr, hdr->daddr.s6_addr, 16); |
8df8c56a JR |
577 | } |
578 | } else { | |
556a5bfc AA |
579 | if (addr_type & IPV6_ADDR_LINKLOCAL) { |
580 | /* TODO: context lookup */ | |
84ca5e03 | 581 | iphc1 |= lowpan_compress_addr_64(&hc_ptr, |
8df8c56a JR |
582 | LOWPAN_IPHC_DAM_BIT, &hdr->daddr, _daddr); |
583 | pr_debug("dest address unicast link-local %pI6c " | |
7fc4cfda | 584 | "iphc1 0x%02x\n", &hdr->daddr, iphc1); |
8df8c56a JR |
585 | } else { |
586 | pr_debug("dest address unicast %pI6c\n", &hdr->daddr); | |
85c71240 | 587 | lowpan_push_hc_data(&hc_ptr, hdr->daddr.s6_addr, 16); |
8df8c56a JR |
588 | } |
589 | } | |
590 | ||
cc6ed268 AA |
591 | /* next header compression */ |
592 | if (iphc0 & LOWPAN_IPHC_NH_C) { | |
593 | ret = lowpan_nhc_do_compression(skb, hdr, &hc_ptr); | |
594 | if (ret < 0) | |
595 | return ret; | |
596 | } | |
8df8c56a JR |
597 | |
598 | head[0] = iphc0; | |
599 | head[1] = iphc1; | |
600 | ||
601 | skb_pull(skb, sizeof(struct ipv6hdr)); | |
602 | skb_reset_transport_header(skb); | |
84ca5e03 | 603 | memcpy(skb_push(skb, hc_ptr - head), head, hc_ptr - head); |
8df8c56a JR |
604 | skb_reset_network_header(skb); |
605 | ||
84ca5e03 | 606 | pr_debug("header len %d skb %u\n", (int)(hc_ptr - head), skb->len); |
8df8c56a JR |
607 | |
608 | raw_dump_table(__func__, "raw skb data dump compressed", | |
4710d806 | 609 | skb->data, skb->len); |
8df8c56a JR |
610 | return 0; |
611 | } | |
612 | EXPORT_SYMBOL_GPL(lowpan_header_compress); | |
5ae5e991 | 613 | |
cc6ed268 AA |
614 | static int __init lowpan_module_init(void) |
615 | { | |
ff0fcc29 AA |
616 | request_module_nowait("nhc_dest"); |
617 | request_module_nowait("nhc_fragment"); | |
618 | request_module_nowait("nhc_hop"); | |
619 | request_module_nowait("nhc_ipv6"); | |
620 | request_module_nowait("nhc_mobility"); | |
621 | request_module_nowait("nhc_routing"); | |
cc6ed268 AA |
622 | request_module_nowait("nhc_udp"); |
623 | ||
624 | return 0; | |
625 | } | |
626 | module_init(lowpan_module_init); | |
627 | ||
5ae5e991 | 628 | MODULE_LICENSE("GPL"); |