[457] | 1 | /**
|
---|
| 2 | * @file
|
---|
| 3 | *
|
---|
| 4 | * Common 6LowPAN routines for IPv6. Uses ND tables for link-layer addressing. Fragments packets to 6LowPAN units.
|
---|
| 5 | *
|
---|
| 6 | * This implementation aims to conform to IEEE 802.15.4(-2015), RFC 4944 and RFC 6282.
|
---|
| 7 | * @todo: RFC 6775.
|
---|
| 8 | */
|
---|
| 9 |
|
---|
| 10 | /*
|
---|
| 11 | * Copyright (c) 2015 Inico Technologies Ltd.
|
---|
| 12 | * All rights reserved.
|
---|
| 13 | *
|
---|
| 14 | * Redistribution and use in source and binary forms, with or without modification,
|
---|
| 15 | * are permitted provided that the following conditions are met:
|
---|
| 16 | *
|
---|
| 17 | * 1. Redistributions of source code must retain the above copyright notice,
|
---|
| 18 | * this list of conditions and the following disclaimer.
|
---|
| 19 | * 2. Redistributions in binary form must reproduce the above copyright notice,
|
---|
| 20 | * this list of conditions and the following disclaimer in the documentation
|
---|
| 21 | * and/or other materials provided with the distribution.
|
---|
| 22 | * 3. The name of the author may not be used to endorse or promote products
|
---|
| 23 | * derived from this software without specific prior written permission.
|
---|
| 24 | *
|
---|
| 25 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
|
---|
| 26 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
---|
| 27 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
|
---|
| 28 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
---|
| 29 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
|
---|
| 30 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
---|
| 31 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
---|
| 32 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
|
---|
| 33 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
|
---|
| 34 | * OF SUCH DAMAGE.
|
---|
| 35 | *
|
---|
| 36 | * This file is part of the lwIP TCP/IP stack.
|
---|
| 37 | *
|
---|
| 38 | * Author: Ivan Delamer <delamer@inicotech.com>
|
---|
| 39 | *
|
---|
| 40 | *
|
---|
| 41 | * Please coordinate changes and requests with Ivan Delamer
|
---|
| 42 | * <delamer@inicotech.com>
|
---|
| 43 | */
|
---|
| 44 |
|
---|
| 45 | /**
|
---|
| 46 | * @defgroup sixlowpan 6LoWPAN (RFC4944)
|
---|
| 47 | * @ingroup netifs
|
---|
| 48 | * 6LowPAN netif implementation
|
---|
| 49 | */
|
---|
| 50 |
|
---|
| 51 | #include "netif/lowpan6_common.h"
|
---|
| 52 |
|
---|
| 53 | #if LWIP_IPV6
|
---|
| 54 |
|
---|
| 55 | #include "lwip/ip.h"
|
---|
| 56 | #include "lwip/pbuf.h"
|
---|
| 57 | #include "lwip/ip_addr.h"
|
---|
| 58 | #include "lwip/netif.h"
|
---|
| 59 | #include "lwip/udp.h"
|
---|
| 60 |
|
---|
| 61 | #include <string.h>
|
---|
| 62 |
|
---|
| 63 | /* Determine compression mode for unicast address. */
|
---|
| 64 | s8_t
|
---|
| 65 | lowpan6_get_address_mode(const ip6_addr_t *ip6addr, const struct lowpan6_link_addr *mac_addr)
|
---|
| 66 | {
|
---|
| 67 | if (mac_addr->addr_len == 2) {
|
---|
| 68 | if ((ip6addr->addr[2] == (u32_t)PP_HTONL(0x000000ff)) &&
|
---|
| 69 | ((ip6addr->addr[3] & PP_HTONL(0xffff0000)) == PP_NTOHL(0xfe000000))) {
|
---|
| 70 | if ((ip6addr->addr[3] & PP_HTONL(0x0000ffff)) == lwip_ntohl((mac_addr->addr[0] << 8) | mac_addr->addr[1])) {
|
---|
| 71 | return 3;
|
---|
| 72 | }
|
---|
| 73 | }
|
---|
| 74 | } else if (mac_addr->addr_len == 8) {
|
---|
| 75 | if ((ip6addr->addr[2] == lwip_ntohl(((mac_addr->addr[0] ^ 2) << 24) | (mac_addr->addr[1] << 16) | mac_addr->addr[2] << 8 | mac_addr->addr[3])) &&
|
---|
| 76 | (ip6addr->addr[3] == lwip_ntohl((mac_addr->addr[4] << 24) | (mac_addr->addr[5] << 16) | mac_addr->addr[6] << 8 | mac_addr->addr[7]))) {
|
---|
| 77 | return 3;
|
---|
| 78 | }
|
---|
| 79 | }
|
---|
| 80 |
|
---|
| 81 | if ((ip6addr->addr[2] == PP_HTONL(0x000000ffUL)) &&
|
---|
| 82 | ((ip6addr->addr[3] & PP_HTONL(0xffff0000)) == PP_NTOHL(0xfe000000UL))) {
|
---|
| 83 | return 2;
|
---|
| 84 | }
|
---|
| 85 |
|
---|
| 86 | return 1;
|
---|
| 87 | }
|
---|
| 88 |
|
---|
| 89 | #if LWIP_6LOWPAN_IPHC
|
---|
| 90 |
|
---|
| 91 | /* Determine compression mode for multicast address. */
|
---|
| 92 | static s8_t
|
---|
| 93 | lowpan6_get_address_mode_mc(const ip6_addr_t *ip6addr)
|
---|
| 94 | {
|
---|
| 95 | if ((ip6addr->addr[0] == PP_HTONL(0xff020000)) &&
|
---|
| 96 | (ip6addr->addr[1] == 0) &&
|
---|
| 97 | (ip6addr->addr[2] == 0) &&
|
---|
| 98 | ((ip6addr->addr[3] & PP_HTONL(0xffffff00)) == 0)) {
|
---|
| 99 | return 3;
|
---|
| 100 | } else if (((ip6addr->addr[0] & PP_HTONL(0xff00ffff)) == PP_HTONL(0xff000000)) &&
|
---|
| 101 | (ip6addr->addr[1] == 0)) {
|
---|
| 102 | if ((ip6addr->addr[2] == 0) &&
|
---|
| 103 | ((ip6addr->addr[3] & PP_HTONL(0xff000000)) == 0)) {
|
---|
| 104 | return 2;
|
---|
| 105 | } else if ((ip6addr->addr[2] & PP_HTONL(0xffffff00)) == 0) {
|
---|
| 106 | return 1;
|
---|
| 107 | }
|
---|
| 108 | }
|
---|
| 109 |
|
---|
| 110 | return 0;
|
---|
| 111 | }
|
---|
| 112 |
|
---|
| 113 | #if LWIP_6LOWPAN_NUM_CONTEXTS > 0
|
---|
| 114 | static s8_t
|
---|
| 115 | lowpan6_context_lookup(const ip6_addr_t *lowpan6_contexts, const ip6_addr_t *ip6addr)
|
---|
| 116 | {
|
---|
| 117 | s8_t i;
|
---|
| 118 |
|
---|
| 119 | for (i = 0; i < LWIP_6LOWPAN_NUM_CONTEXTS; i++) {
|
---|
| 120 | if (ip6_addr_netcmp(&lowpan6_contexts[i], ip6addr)) {
|
---|
| 121 | return i;
|
---|
| 122 | }
|
---|
| 123 | }
|
---|
| 124 | return -1;
|
---|
| 125 | }
|
---|
| 126 | #endif /* LWIP_6LOWPAN_NUM_CONTEXTS > 0 */
|
---|
| 127 |
|
---|
| 128 | /*
|
---|
| 129 | * Compress IPv6 and/or UDP headers.
|
---|
| 130 | * */
|
---|
| 131 | err_t
|
---|
| 132 | lowpan6_compress_headers(struct netif *netif, u8_t *inbuf, size_t inbuf_size, u8_t *outbuf, size_t outbuf_size,
|
---|
| 133 | u8_t *lowpan6_header_len_out, u8_t *hidden_header_len_out, ip6_addr_t *lowpan6_contexts,
|
---|
| 134 | const struct lowpan6_link_addr *src, const struct lowpan6_link_addr *dst)
|
---|
| 135 | {
|
---|
| 136 | u8_t *buffer, *inptr;
|
---|
| 137 | u8_t lowpan6_header_len;
|
---|
| 138 | u8_t hidden_header_len = 0;
|
---|
| 139 | s8_t i;
|
---|
| 140 | struct ip6_hdr *ip6hdr;
|
---|
| 141 | ip_addr_t ip6src, ip6dst;
|
---|
| 142 |
|
---|
| 143 | LWIP_ASSERT("netif != NULL", netif != NULL);
|
---|
| 144 | LWIP_ASSERT("inbuf != NULL", inbuf != NULL);
|
---|
| 145 | LWIP_ASSERT("outbuf != NULL", outbuf != NULL);
|
---|
| 146 | LWIP_ASSERT("lowpan6_header_len_out != NULL", lowpan6_header_len_out != NULL);
|
---|
| 147 | LWIP_ASSERT("hidden_header_len_out != NULL", hidden_header_len_out != NULL);
|
---|
| 148 |
|
---|
| 149 | /* Perform 6LowPAN IPv6 header compression according to RFC 6282 */
|
---|
| 150 | buffer = outbuf;
|
---|
| 151 | inptr = inbuf;
|
---|
| 152 |
|
---|
| 153 | if (inbuf_size < IP6_HLEN) {
|
---|
| 154 | /* input buffer too short */
|
---|
| 155 | return ERR_VAL;
|
---|
| 156 | }
|
---|
| 157 | if (outbuf_size < IP6_HLEN) {
|
---|
| 158 | /* output buffer too short for worst case */
|
---|
| 159 | return ERR_MEM;
|
---|
| 160 | }
|
---|
| 161 |
|
---|
| 162 | /* Point to ip6 header and align copies of src/dest addresses. */
|
---|
| 163 | ip6hdr = (struct ip6_hdr *)inptr;
|
---|
| 164 | ip_addr_copy_from_ip6_packed(ip6dst, ip6hdr->dest);
|
---|
| 165 | ip6_addr_assign_zone(ip_2_ip6(&ip6dst), IP6_UNKNOWN, netif);
|
---|
| 166 | ip_addr_copy_from_ip6_packed(ip6src, ip6hdr->src);
|
---|
| 167 | ip6_addr_assign_zone(ip_2_ip6(&ip6src), IP6_UNKNOWN, netif);
|
---|
| 168 |
|
---|
| 169 | /* Basic length of 6LowPAN header, set dispatch and clear fields. */
|
---|
| 170 | lowpan6_header_len = 2;
|
---|
| 171 | buffer[0] = 0x60;
|
---|
| 172 | buffer[1] = 0;
|
---|
| 173 |
|
---|
| 174 | /* Determine whether there will be a Context Identifier Extension byte or not.
|
---|
| 175 | * If so, set it already. */
|
---|
| 176 | #if LWIP_6LOWPAN_NUM_CONTEXTS > 0
|
---|
| 177 | buffer[2] = 0;
|
---|
| 178 |
|
---|
| 179 | i = lowpan6_context_lookup(lowpan6_contexts, ip_2_ip6(&ip6src));
|
---|
| 180 | if (i >= 0) {
|
---|
| 181 | /* Stateful source address compression. */
|
---|
| 182 | buffer[1] |= 0x40;
|
---|
| 183 | buffer[2] |= (i & 0x0f) << 4;
|
---|
| 184 | }
|
---|
| 185 |
|
---|
| 186 | i = lowpan6_context_lookup(lowpan6_contexts, ip_2_ip6(&ip6dst));
|
---|
| 187 | if (i >= 0) {
|
---|
| 188 | /* Stateful destination address compression. */
|
---|
| 189 | buffer[1] |= 0x04;
|
---|
| 190 | buffer[2] |= i & 0x0f;
|
---|
| 191 | }
|
---|
| 192 |
|
---|
| 193 | if (buffer[2] != 0x00) {
|
---|
| 194 | /* Context identifier extension byte is appended. */
|
---|
| 195 | buffer[1] |= 0x80;
|
---|
| 196 | lowpan6_header_len++;
|
---|
| 197 | }
|
---|
| 198 | #else /* LWIP_6LOWPAN_NUM_CONTEXTS > 0 */
|
---|
| 199 | LWIP_UNUSED_ARG(lowpan6_contexts);
|
---|
| 200 | #endif /* LWIP_6LOWPAN_NUM_CONTEXTS > 0 */
|
---|
| 201 |
|
---|
| 202 | /* Determine TF field: Traffic Class, Flow Label */
|
---|
| 203 | if (IP6H_FL(ip6hdr) == 0) {
|
---|
| 204 | /* Flow label is elided. */
|
---|
| 205 | buffer[0] |= 0x10;
|
---|
| 206 | if (IP6H_TC(ip6hdr) == 0) {
|
---|
| 207 | /* Traffic class (ECN+DSCP) elided too. */
|
---|
| 208 | buffer[0] |= 0x08;
|
---|
| 209 | } else {
|
---|
| 210 | /* Traffic class (ECN+DSCP) appended. */
|
---|
| 211 | buffer[lowpan6_header_len++] = IP6H_TC(ip6hdr);
|
---|
| 212 | }
|
---|
| 213 | } else {
|
---|
| 214 | if (((IP6H_TC(ip6hdr) & 0x3f) == 0)) {
|
---|
| 215 | /* DSCP portion of Traffic Class is elided, ECN and FL are appended (3 bytes) */
|
---|
| 216 | buffer[0] |= 0x08;
|
---|
| 217 |
|
---|
| 218 | buffer[lowpan6_header_len] = IP6H_TC(ip6hdr) & 0xc0;
|
---|
| 219 | buffer[lowpan6_header_len++] |= (IP6H_FL(ip6hdr) >> 16) & 0x0f;
|
---|
| 220 | buffer[lowpan6_header_len++] = (IP6H_FL(ip6hdr) >> 8) & 0xff;
|
---|
| 221 | buffer[lowpan6_header_len++] = IP6H_FL(ip6hdr) & 0xff;
|
---|
| 222 | } else {
|
---|
| 223 | /* Traffic class and flow label are appended (4 bytes) */
|
---|
| 224 | buffer[lowpan6_header_len++] = IP6H_TC(ip6hdr);
|
---|
| 225 | buffer[lowpan6_header_len++] = (IP6H_FL(ip6hdr) >> 16) & 0x0f;
|
---|
| 226 | buffer[lowpan6_header_len++] = (IP6H_FL(ip6hdr) >> 8) & 0xff;
|
---|
| 227 | buffer[lowpan6_header_len++] = IP6H_FL(ip6hdr) & 0xff;
|
---|
| 228 | }
|
---|
| 229 | }
|
---|
| 230 |
|
---|
| 231 | /* Compress NH?
|
---|
| 232 | * Only if UDP for now. @todo support other NH compression. */
|
---|
| 233 | if (IP6H_NEXTH(ip6hdr) == IP6_NEXTH_UDP) {
|
---|
| 234 | buffer[0] |= 0x04;
|
---|
| 235 | } else {
|
---|
| 236 | /* append nexth. */
|
---|
| 237 | buffer[lowpan6_header_len++] = IP6H_NEXTH(ip6hdr);
|
---|
| 238 | }
|
---|
| 239 |
|
---|
| 240 | /* Compress hop limit? */
|
---|
| 241 | if (IP6H_HOPLIM(ip6hdr) == 255) {
|
---|
| 242 | buffer[0] |= 0x03;
|
---|
| 243 | } else if (IP6H_HOPLIM(ip6hdr) == 64) {
|
---|
| 244 | buffer[0] |= 0x02;
|
---|
| 245 | } else if (IP6H_HOPLIM(ip6hdr) == 1) {
|
---|
| 246 | buffer[0] |= 0x01;
|
---|
| 247 | } else {
|
---|
| 248 | /* append hop limit */
|
---|
| 249 | buffer[lowpan6_header_len++] = IP6H_HOPLIM(ip6hdr);
|
---|
| 250 | }
|
---|
| 251 |
|
---|
| 252 | /* Compress source address */
|
---|
| 253 | if (((buffer[1] & 0x40) != 0) ||
|
---|
| 254 | (ip6_addr_islinklocal(ip_2_ip6(&ip6src)))) {
|
---|
| 255 | /* Context-based or link-local source address compression. */
|
---|
| 256 | i = lowpan6_get_address_mode(ip_2_ip6(&ip6src), src);
|
---|
| 257 | buffer[1] |= (i & 0x03) << 4;
|
---|
| 258 | if (i == 1) {
|
---|
| 259 | MEMCPY(buffer + lowpan6_header_len, inptr + 16, 8);
|
---|
| 260 | lowpan6_header_len += 8;
|
---|
| 261 | } else if (i == 2) {
|
---|
| 262 | MEMCPY(buffer + lowpan6_header_len, inptr + 22, 2);
|
---|
| 263 | lowpan6_header_len += 2;
|
---|
| 264 | }
|
---|
| 265 | } else if (ip6_addr_isany(ip_2_ip6(&ip6src))) {
|
---|
| 266 | /* Special case: mark SAC and leave SAM=0 */
|
---|
| 267 | buffer[1] |= 0x40;
|
---|
| 268 | } else {
|
---|
| 269 | /* Append full address. */
|
---|
| 270 | MEMCPY(buffer + lowpan6_header_len, inptr + 8, 16);
|
---|
| 271 | lowpan6_header_len += 16;
|
---|
| 272 | }
|
---|
| 273 |
|
---|
| 274 | /* Compress destination address */
|
---|
| 275 | if (ip6_addr_ismulticast(ip_2_ip6(&ip6dst))) {
|
---|
| 276 | /* @todo support stateful multicast address compression */
|
---|
| 277 |
|
---|
| 278 | buffer[1] |= 0x08;
|
---|
| 279 |
|
---|
| 280 | i = lowpan6_get_address_mode_mc(ip_2_ip6(&ip6dst));
|
---|
| 281 | buffer[1] |= i & 0x03;
|
---|
| 282 | if (i == 0) {
|
---|
| 283 | MEMCPY(buffer + lowpan6_header_len, inptr + 24, 16);
|
---|
| 284 | lowpan6_header_len += 16;
|
---|
| 285 | } else if (i == 1) {
|
---|
| 286 | buffer[lowpan6_header_len++] = inptr[25];
|
---|
| 287 | MEMCPY(buffer + lowpan6_header_len, inptr + 35, 5);
|
---|
| 288 | lowpan6_header_len += 5;
|
---|
| 289 | } else if (i == 2) {
|
---|
| 290 | buffer[lowpan6_header_len++] = inptr[25];
|
---|
| 291 | MEMCPY(buffer + lowpan6_header_len, inptr + 37, 3);
|
---|
| 292 | lowpan6_header_len += 3;
|
---|
| 293 | } else if (i == 3) {
|
---|
| 294 | buffer[lowpan6_header_len++] = (inptr)[39];
|
---|
| 295 | }
|
---|
| 296 | } else if (((buffer[1] & 0x04) != 0) ||
|
---|
| 297 | (ip6_addr_islinklocal(ip_2_ip6(&ip6dst)))) {
|
---|
| 298 | /* Context-based or link-local destination address compression. */
|
---|
| 299 | i = lowpan6_get_address_mode(ip_2_ip6(&ip6dst), dst);
|
---|
| 300 | buffer[1] |= i & 0x03;
|
---|
| 301 | if (i == 1) {
|
---|
| 302 | MEMCPY(buffer + lowpan6_header_len, inptr + 32, 8);
|
---|
| 303 | lowpan6_header_len += 8;
|
---|
| 304 | } else if (i == 2) {
|
---|
| 305 | MEMCPY(buffer + lowpan6_header_len, inptr + 38, 2);
|
---|
| 306 | lowpan6_header_len += 2;
|
---|
| 307 | }
|
---|
| 308 | } else {
|
---|
| 309 | /* Append full address. */
|
---|
| 310 | MEMCPY(buffer + lowpan6_header_len, inptr + 24, 16);
|
---|
| 311 | lowpan6_header_len += 16;
|
---|
| 312 | }
|
---|
| 313 |
|
---|
| 314 | /* Move to payload. */
|
---|
| 315 | inptr += IP6_HLEN;
|
---|
| 316 | hidden_header_len += IP6_HLEN;
|
---|
| 317 |
|
---|
| 318 | #if LWIP_UDP
|
---|
| 319 | /* Compress UDP header? */
|
---|
| 320 | if (IP6H_NEXTH(ip6hdr) == IP6_NEXTH_UDP) {
|
---|
| 321 | /* @todo support optional checksum compression */
|
---|
| 322 |
|
---|
| 323 | if (inbuf_size < IP6_HLEN + UDP_HLEN) {
|
---|
| 324 | /* input buffer too short */
|
---|
| 325 | return ERR_VAL;
|
---|
| 326 | }
|
---|
| 327 | if (outbuf_size < (size_t)(hidden_header_len + 7)) {
|
---|
| 328 | /* output buffer too short for worst case */
|
---|
| 329 | return ERR_MEM;
|
---|
| 330 | }
|
---|
| 331 |
|
---|
| 332 | buffer[lowpan6_header_len] = 0xf0;
|
---|
| 333 |
|
---|
| 334 | /* determine port compression mode. */
|
---|
| 335 | if ((inptr[0] == 0xf0) && ((inptr[1] & 0xf0) == 0xb0) &&
|
---|
| 336 | (inptr[2] == 0xf0) && ((inptr[3] & 0xf0) == 0xb0)) {
|
---|
| 337 | /* Compress source and dest ports. */
|
---|
| 338 | buffer[lowpan6_header_len++] |= 0x03;
|
---|
| 339 | buffer[lowpan6_header_len++] = ((inptr[1] & 0x0f) << 4) | (inptr[3] & 0x0f);
|
---|
| 340 | } else if (inptr[0] == 0xf0) {
|
---|
| 341 | /* Compress source port. */
|
---|
| 342 | buffer[lowpan6_header_len++] |= 0x02;
|
---|
| 343 | buffer[lowpan6_header_len++] = inptr[1];
|
---|
| 344 | buffer[lowpan6_header_len++] = inptr[2];
|
---|
| 345 | buffer[lowpan6_header_len++] = inptr[3];
|
---|
| 346 | } else if (inptr[2] == 0xf0) {
|
---|
| 347 | /* Compress dest port. */
|
---|
| 348 | buffer[lowpan6_header_len++] |= 0x01;
|
---|
| 349 | buffer[lowpan6_header_len++] = inptr[0];
|
---|
| 350 | buffer[lowpan6_header_len++] = inptr[1];
|
---|
| 351 | buffer[lowpan6_header_len++] = inptr[3];
|
---|
| 352 | } else {
|
---|
| 353 | /* append full ports. */
|
---|
| 354 | lowpan6_header_len++;
|
---|
| 355 | buffer[lowpan6_header_len++] = inptr[0];
|
---|
| 356 | buffer[lowpan6_header_len++] = inptr[1];
|
---|
| 357 | buffer[lowpan6_header_len++] = inptr[2];
|
---|
| 358 | buffer[lowpan6_header_len++] = inptr[3];
|
---|
| 359 | }
|
---|
| 360 |
|
---|
| 361 | /* elide length and copy checksum */
|
---|
| 362 | buffer[lowpan6_header_len++] = inptr[6];
|
---|
| 363 | buffer[lowpan6_header_len++] = inptr[7];
|
---|
| 364 |
|
---|
| 365 | hidden_header_len += UDP_HLEN;
|
---|
| 366 | }
|
---|
| 367 | #endif /* LWIP_UDP */
|
---|
| 368 |
|
---|
| 369 | *lowpan6_header_len_out = lowpan6_header_len;
|
---|
| 370 | *hidden_header_len_out = hidden_header_len;
|
---|
| 371 |
|
---|
| 372 | return ERR_OK;
|
---|
| 373 | }
|
---|
| 374 |
|
---|
| 375 | /** Decompress IPv6 and UDP headers compressed according to RFC 6282
|
---|
| 376 | *
|
---|
| 377 | * @param lowpan6_buffer compressed headers, first byte is the dispatch byte
|
---|
| 378 | * @param lowpan6_bufsize size of lowpan6_buffer (may include data after headers)
|
---|
| 379 | * @param decomp_buffer buffer where the decompressed headers are stored
|
---|
| 380 | * @param decomp_bufsize size of decomp_buffer
|
---|
| 381 | * @param hdr_size_comp returns the size of the compressed headers (skip to get to data)
|
---|
| 382 | * @param hdr_size_decomp returns the size of the decompressed headers (IPv6 + UDP)
|
---|
| 383 | * @param datagram_size datagram size from fragments or 0 if unfragmented
|
---|
| 384 | * @param compressed_size compressed datagram size (for unfragmented rx)
|
---|
| 385 | * @param lowpan6_contexts context addresses
|
---|
| 386 | * @param src source address of the outer layer, used for address compression
|
---|
| 387 | * @param dest destination address of the outer layer, used for address compression
|
---|
| 388 | * @return ERR_OK if decompression succeeded, an error otherwise
|
---|
| 389 | */
|
---|
| 390 | static err_t
|
---|
| 391 | lowpan6_decompress_hdr(u8_t *lowpan6_buffer, size_t lowpan6_bufsize,
|
---|
| 392 | u8_t *decomp_buffer, size_t decomp_bufsize,
|
---|
| 393 | u16_t *hdr_size_comp, u16_t *hdr_size_decomp,
|
---|
| 394 | u16_t datagram_size, u16_t compressed_size,
|
---|
| 395 | ip6_addr_t *lowpan6_contexts,
|
---|
| 396 | struct lowpan6_link_addr *src, struct lowpan6_link_addr *dest)
|
---|
| 397 | {
|
---|
| 398 | u16_t lowpan6_offset;
|
---|
| 399 | struct ip6_hdr *ip6hdr;
|
---|
| 400 | s8_t i;
|
---|
| 401 | u32_t header_temp;
|
---|
| 402 | u16_t ip6_offset = IP6_HLEN;
|
---|
| 403 |
|
---|
| 404 | LWIP_ASSERT("lowpan6_buffer != NULL", lowpan6_buffer != NULL);
|
---|
| 405 | LWIP_ASSERT("decomp_buffer != NULL", decomp_buffer != NULL);
|
---|
| 406 | LWIP_ASSERT("src != NULL", src != NULL);
|
---|
| 407 | LWIP_ASSERT("dest != NULL", dest != NULL);
|
---|
| 408 | LWIP_ASSERT("hdr_size_comp != NULL", hdr_size_comp != NULL);
|
---|
| 409 | LWIP_ASSERT("dehdr_size_decompst != NULL", hdr_size_decomp != NULL);
|
---|
| 410 |
|
---|
| 411 | ip6hdr = (struct ip6_hdr *)decomp_buffer;
|
---|
| 412 | if (decomp_bufsize < IP6_HLEN) {
|
---|
| 413 | return ERR_MEM;
|
---|
| 414 | }
|
---|
| 415 |
|
---|
| 416 | /* output the full compressed packet, if set in @see lowpan6_opts.h */
|
---|
| 417 | #if LWIP_LOWPAN6_IP_COMPRESSED_DEBUG
|
---|
| 418 | {
|
---|
| 419 | u16_t j;
|
---|
| 420 | LWIP_DEBUGF(LWIP_LOWPAN6_IP_COMPRESSED_DEBUG, ("lowpan6_decompress_hdr: IP6 payload (compressed): \n"));
|
---|
| 421 | for (j = 0; j < lowpan6_bufsize; j++) {
|
---|
| 422 | if ((j % 4) == 0) {
|
---|
| 423 | LWIP_DEBUGF(LWIP_LOWPAN6_IP_COMPRESSED_DEBUG, ("\n"));
|
---|
| 424 | }
|
---|
| 425 | LWIP_DEBUGF(LWIP_LOWPAN6_IP_COMPRESSED_DEBUG, ("%2X ", lowpan6_buffer[j]));
|
---|
| 426 | }
|
---|
| 427 | LWIP_DEBUGF(LWIP_LOWPAN6_IP_COMPRESSED_DEBUG, ("\np->len: %d", lowpan6_bufsize));
|
---|
| 428 | }
|
---|
| 429 | #endif
|
---|
| 430 |
|
---|
| 431 | /* offset for inline IP headers (RFC 6282 ch3)*/
|
---|
| 432 | lowpan6_offset = 2;
|
---|
| 433 | /* if CID is set (context identifier), the context byte
|
---|
| 434 | * follows immediately after the header, so other IPHC fields are @+3 */
|
---|
| 435 | if (lowpan6_buffer[1] & 0x80) {
|
---|
| 436 | lowpan6_offset++;
|
---|
| 437 | }
|
---|
| 438 |
|
---|
| 439 | /* Set IPv6 version, traffic class and flow label. (RFC6282, ch 3.1.1.)*/
|
---|
| 440 | if ((lowpan6_buffer[0] & 0x18) == 0x00) {
|
---|
| 441 | header_temp = ((lowpan6_buffer[lowpan6_offset+1] & 0x0f) << 16) | \
|
---|
| 442 | (lowpan6_buffer[lowpan6_offset + 2] << 8) | lowpan6_buffer[lowpan6_offset+3];
|
---|
| 443 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("TF: 00, ECN: 0x%2x, Flowlabel+DSCP: 0x%8X\n", \
|
---|
| 444 | lowpan6_buffer[lowpan6_offset],header_temp));
|
---|
| 445 | IP6H_VTCFL_SET(ip6hdr, 6, lowpan6_buffer[lowpan6_offset], header_temp);
|
---|
| 446 | /* increase offset, processed 4 bytes here:
|
---|
| 447 | * TF=00: ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)*/
|
---|
| 448 | lowpan6_offset += 4;
|
---|
| 449 | } else if ((lowpan6_buffer[0] & 0x18) == 0x08) {
|
---|
| 450 | header_temp = ((lowpan6_buffer[lowpan6_offset] & 0x0f) << 16) | (lowpan6_buffer[lowpan6_offset + 1] << 8) | lowpan6_buffer[lowpan6_offset+2];
|
---|
| 451 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("TF: 01, ECN: 0x%2x, Flowlabel: 0x%2X, DSCP ignored\n", \
|
---|
| 452 | lowpan6_buffer[lowpan6_offset] & 0xc0,header_temp));
|
---|
| 453 | IP6H_VTCFL_SET(ip6hdr, 6, lowpan6_buffer[lowpan6_offset] & 0xc0, header_temp);
|
---|
| 454 | /* increase offset, processed 3 bytes here:
|
---|
| 455 | * TF=01: ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided.*/
|
---|
| 456 | lowpan6_offset += 3;
|
---|
| 457 | } else if ((lowpan6_buffer[0] & 0x18) == 0x10) {
|
---|
| 458 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("TF: 10, DCSP+ECN: 0x%2x, Flowlabel ignored\n", lowpan6_buffer[lowpan6_offset]));
|
---|
| 459 | IP6H_VTCFL_SET(ip6hdr, 6, lowpan6_buffer[lowpan6_offset],0);
|
---|
| 460 | /* increase offset, processed 1 byte here:
|
---|
| 461 | * ECN + DSCP (1 byte), Flow Label is elided.*/
|
---|
| 462 | lowpan6_offset += 1;
|
---|
| 463 | } else if ((lowpan6_buffer[0] & 0x18) == 0x18) {
|
---|
| 464 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("TF: 11, DCSP/ECN & Flowlabel ignored\n"));
|
---|
| 465 | /* don't increase offset, no bytes processed here */
|
---|
| 466 | IP6H_VTCFL_SET(ip6hdr, 6, 0, 0);
|
---|
| 467 | }
|
---|
| 468 |
|
---|
| 469 | /* Set Next Header (NH) */
|
---|
| 470 | if ((lowpan6_buffer[0] & 0x04) == 0x00) {
|
---|
| 471 | /* 0: full next header byte carried inline (increase offset)*/
|
---|
| 472 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("NH: 0x%2X\n", lowpan6_buffer[lowpan6_offset+1]));
|
---|
| 473 | IP6H_NEXTH_SET(ip6hdr, lowpan6_buffer[lowpan6_offset++]);
|
---|
| 474 | } else {
|
---|
| 475 | /* 1: NH compression, LOWPAN_NHC (RFC6282, ch 4.1) */
|
---|
| 476 | /* We should fill this later with NHC decoding */
|
---|
| 477 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("NH: skipped, later done with NHC\n"));
|
---|
| 478 | IP6H_NEXTH_SET(ip6hdr, 0);
|
---|
| 479 | }
|
---|
| 480 |
|
---|
| 481 | /* Set Hop Limit, either carried inline or 3 different hops (1,64,255) */
|
---|
| 482 | if ((lowpan6_buffer[0] & 0x03) == 0x00) {
|
---|
| 483 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("Hops: full value: %d\n", lowpan6_buffer[lowpan6_offset+1]));
|
---|
| 484 | IP6H_HOPLIM_SET(ip6hdr, lowpan6_buffer[lowpan6_offset++]);
|
---|
| 485 | } else if ((lowpan6_buffer[0] & 0x03) == 0x01) {
|
---|
| 486 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("Hops: compressed: 1\n"));
|
---|
| 487 | IP6H_HOPLIM_SET(ip6hdr, 1);
|
---|
| 488 | } else if ((lowpan6_buffer[0] & 0x03) == 0x02) {
|
---|
| 489 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("Hops: compressed: 64\n"));
|
---|
| 490 | IP6H_HOPLIM_SET(ip6hdr, 64);
|
---|
| 491 | } else if ((lowpan6_buffer[0] & 0x03) == 0x03) {
|
---|
| 492 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("Hops: compressed: 255\n"));
|
---|
| 493 | IP6H_HOPLIM_SET(ip6hdr, 255);
|
---|
| 494 | }
|
---|
| 495 |
|
---|
| 496 | /* Source address decoding. */
|
---|
| 497 | if ((lowpan6_buffer[1] & 0x40) == 0x00) {
|
---|
| 498 | /* Source address compression (SAC) = 0 -> stateless compression */
|
---|
| 499 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("SAC == 0, no context byte\n"));
|
---|
| 500 | /* Stateless compression */
|
---|
| 501 | if ((lowpan6_buffer[1] & 0x30) == 0x00) {
|
---|
| 502 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("SAM == 00, no src compression, fetching 128bits inline\n"));
|
---|
| 503 | /* copy full address, increase offset by 16 Bytes */
|
---|
| 504 | MEMCPY(&ip6hdr->src.addr[0], lowpan6_buffer + lowpan6_offset, 16);
|
---|
| 505 | lowpan6_offset += 16;
|
---|
| 506 | } else if ((lowpan6_buffer[1] & 0x30) == 0x10) {
|
---|
| 507 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("SAM == 01, src compression, 64bits inline\n"));
|
---|
| 508 | /* set 64 bits to link local */
|
---|
| 509 | ip6hdr->src.addr[0] = PP_HTONL(0xfe800000UL);
|
---|
| 510 | ip6hdr->src.addr[1] = 0;
|
---|
| 511 | /* copy 8 Bytes, increase offset */
|
---|
| 512 | MEMCPY(&ip6hdr->src.addr[2], lowpan6_buffer + lowpan6_offset, 8);
|
---|
| 513 | lowpan6_offset += 8;
|
---|
| 514 | } else if ((lowpan6_buffer[1] & 0x30) == 0x20) {
|
---|
| 515 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("SAM == 10, src compression, 16bits inline\n"));
|
---|
| 516 | /* set 96 bits to link local */
|
---|
| 517 | ip6hdr->src.addr[0] = PP_HTONL(0xfe800000UL);
|
---|
| 518 | ip6hdr->src.addr[1] = 0;
|
---|
| 519 | ip6hdr->src.addr[2] = PP_HTONL(0x000000ffUL);
|
---|
| 520 | /* extract remaining 16bits from inline bytes, increase offset */
|
---|
| 521 | ip6hdr->src.addr[3] = lwip_htonl(0xfe000000UL | (lowpan6_buffer[lowpan6_offset] << 8) |
|
---|
| 522 | lowpan6_buffer[lowpan6_offset + 1]);
|
---|
| 523 | lowpan6_offset += 2;
|
---|
| 524 | } else if ((lowpan6_buffer[1] & 0x30) == 0x30) {
|
---|
| 525 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("SAM == 11, src compression, 0bits inline, using other headers\n"));
|
---|
| 526 | /* no information avalaible, using other layers, see RFC6282 ch 3.2.2 */
|
---|
| 527 | ip6hdr->src.addr[0] = PP_HTONL(0xfe800000UL);
|
---|
| 528 | ip6hdr->src.addr[1] = 0;
|
---|
| 529 | if (src->addr_len == 2) {
|
---|
| 530 | ip6hdr->src.addr[2] = PP_HTONL(0x000000ffUL);
|
---|
| 531 | ip6hdr->src.addr[3] = lwip_htonl(0xfe000000UL | (src->addr[0] << 8) | src->addr[1]);
|
---|
| 532 | } else if (src->addr_len == 8) {
|
---|
| 533 | ip6hdr->src.addr[2] = lwip_htonl(((src->addr[0] ^ 2) << 24) | (src->addr[1] << 16) |
|
---|
| 534 | (src->addr[2] << 8) | src->addr[3]);
|
---|
| 535 | ip6hdr->src.addr[3] = lwip_htonl((src->addr[4] << 24) | (src->addr[5] << 16) |
|
---|
| 536 | (src->addr[6] << 8) | src->addr[7]);
|
---|
| 537 | } else {
|
---|
| 538 | /* invalid source address length */
|
---|
| 539 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("Invalid source address length\n"));
|
---|
| 540 | return ERR_VAL;
|
---|
| 541 | }
|
---|
| 542 | }
|
---|
| 543 | } else {
|
---|
| 544 | /* Source address compression (SAC) = 1 -> stateful/context-based compression */
|
---|
| 545 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("SAC == 1, additional context byte\n"));
|
---|
| 546 | if ((lowpan6_buffer[1] & 0x30) == 0x00) {
|
---|
| 547 | /* SAM=00, address=> :: (ANY) */
|
---|
| 548 | ip6hdr->src.addr[0] = 0;
|
---|
| 549 | ip6hdr->src.addr[1] = 0;
|
---|
| 550 | ip6hdr->src.addr[2] = 0;
|
---|
| 551 | ip6hdr->src.addr[3] = 0;
|
---|
| 552 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("SAM == 00, context compression, ANY (::)\n"));
|
---|
| 553 | } else {
|
---|
| 554 | /* Set prefix from context info */
|
---|
| 555 | if (lowpan6_buffer[1] & 0x80) {
|
---|
| 556 | i = (lowpan6_buffer[2] >> 4) & 0x0f;
|
---|
| 557 | } else {
|
---|
| 558 | i = 0;
|
---|
| 559 | }
|
---|
| 560 | if (i >= LWIP_6LOWPAN_NUM_CONTEXTS) {
|
---|
| 561 | /* Error */
|
---|
| 562 | return ERR_VAL;
|
---|
| 563 | }
|
---|
| 564 | #if LWIP_6LOWPAN_NUM_CONTEXTS > 0
|
---|
| 565 | ip6hdr->src.addr[0] = lowpan6_contexts[i].addr[0];
|
---|
| 566 | ip6hdr->src.addr[1] = lowpan6_contexts[i].addr[1];
|
---|
| 567 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("SAM == xx, context compression found @%d: %8X, %8X\n", (int)i, ip6hdr->src.addr[0], ip6hdr->src.addr[1]));
|
---|
| 568 | #else
|
---|
| 569 | LWIP_UNUSED_ARG(lowpan6_contexts);
|
---|
| 570 | #endif
|
---|
| 571 | }
|
---|
| 572 |
|
---|
| 573 | /* determine further address bits */
|
---|
| 574 | if ((lowpan6_buffer[1] & 0x30) == 0x10) {
|
---|
| 575 | /* SAM=01, load additional 64bits */
|
---|
| 576 | MEMCPY(&ip6hdr->src.addr[2], lowpan6_buffer + lowpan6_offset, 8);
|
---|
| 577 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("SAM == 01, context compression, 64bits inline\n"));
|
---|
| 578 | lowpan6_offset += 8;
|
---|
| 579 | } else if ((lowpan6_buffer[1] & 0x30) == 0x20) {
|
---|
| 580 | /* SAM=01, load additional 16bits */
|
---|
| 581 | ip6hdr->src.addr[2] = PP_HTONL(0x000000ffUL);
|
---|
| 582 | ip6hdr->src.addr[3] = lwip_htonl(0xfe000000UL | (lowpan6_buffer[lowpan6_offset] << 8) | lowpan6_buffer[lowpan6_offset + 1]);
|
---|
| 583 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("SAM == 10, context compression, 16bits inline\n"));
|
---|
| 584 | lowpan6_offset += 2;
|
---|
| 585 | } else if ((lowpan6_buffer[1] & 0x30) == 0x30) {
|
---|
| 586 | /* SAM=11, address is fully elided, load from other layers */
|
---|
| 587 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("SAM == 11, context compression, 0bits inline, using other headers\n"));
|
---|
| 588 | if (src->addr_len == 2) {
|
---|
| 589 | ip6hdr->src.addr[2] = PP_HTONL(0x000000ffUL);
|
---|
| 590 | ip6hdr->src.addr[3] = lwip_htonl(0xfe000000UL | (src->addr[0] << 8) | src->addr[1]);
|
---|
| 591 | } else if (src->addr_len == 8) {
|
---|
| 592 | ip6hdr->src.addr[2] = lwip_htonl(((src->addr[0] ^ 2) << 24) | (src->addr[1] << 16) | (src->addr[2] << 8) | src->addr[3]);
|
---|
| 593 | ip6hdr->src.addr[3] = lwip_htonl((src->addr[4] << 24) | (src->addr[5] << 16) | (src->addr[6] << 8) | src->addr[7]);
|
---|
| 594 | } else {
|
---|
| 595 | /* invalid source address length */
|
---|
| 596 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("Invalid source address length\n"));
|
---|
| 597 | return ERR_VAL;
|
---|
| 598 | }
|
---|
| 599 | }
|
---|
| 600 | }
|
---|
| 601 |
|
---|
| 602 | /* Destination address decoding. */
|
---|
| 603 | if (lowpan6_buffer[1] & 0x08) {
|
---|
| 604 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("M=1: multicast\n"));
|
---|
| 605 | /* Multicast destination */
|
---|
| 606 | if (lowpan6_buffer[1] & 0x04) {
|
---|
| 607 | LWIP_DEBUGF(LWIP_DBG_ON,("DAC == 1, context multicast: unsupported!!!\n"));
|
---|
| 608 | /* @todo support stateful multicast addressing */
|
---|
| 609 | return ERR_VAL;
|
---|
| 610 | }
|
---|
| 611 |
|
---|
| 612 | if ((lowpan6_buffer[1] & 0x03) == 0x00) {
|
---|
| 613 | /* DAM = 00, copy full address (128bits) */
|
---|
| 614 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("DAM == 00, no dst compression, fetching 128bits inline\n"));
|
---|
| 615 | MEMCPY(&ip6hdr->dest.addr[0], lowpan6_buffer + lowpan6_offset, 16);
|
---|
| 616 | lowpan6_offset += 16;
|
---|
| 617 | } else if ((lowpan6_buffer[1] & 0x03) == 0x01) {
|
---|
| 618 | /* DAM = 01, copy 4 bytes (32bits) */
|
---|
| 619 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("DAM == 01, dst address form (48bits): ffXX::00XX:XXXX:XXXX\n"));
|
---|
| 620 | ip6hdr->dest.addr[0] = lwip_htonl(0xff000000UL | (lowpan6_buffer[lowpan6_offset++] << 16));
|
---|
| 621 | ip6hdr->dest.addr[1] = 0;
|
---|
| 622 | ip6hdr->dest.addr[2] = lwip_htonl(lowpan6_buffer[lowpan6_offset++]);
|
---|
| 623 | ip6hdr->dest.addr[3] = lwip_htonl((lowpan6_buffer[lowpan6_offset] << 24) | (lowpan6_buffer[lowpan6_offset + 1] << 16) | (lowpan6_buffer[lowpan6_offset + 2] << 8) | lowpan6_buffer[lowpan6_offset + 3]);
|
---|
| 624 | lowpan6_offset += 4;
|
---|
| 625 | } else if ((lowpan6_buffer[1] & 0x03) == 0x02) {
|
---|
| 626 | /* DAM = 10, copy 3 bytes (24bits) */
|
---|
| 627 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("DAM == 10, dst address form (32bits): ffXX::00XX:XXXX\n"));
|
---|
| 628 | ip6hdr->dest.addr[0] = lwip_htonl(0xff000000UL | (lowpan6_buffer[lowpan6_offset++] << 16));
|
---|
| 629 | ip6hdr->dest.addr[1] = 0;
|
---|
| 630 | ip6hdr->dest.addr[2] = 0;
|
---|
| 631 | ip6hdr->dest.addr[3] = lwip_htonl((lowpan6_buffer[lowpan6_offset] << 16) | (lowpan6_buffer[lowpan6_offset + 1] << 8) | lowpan6_buffer[lowpan6_offset + 2]);
|
---|
| 632 | lowpan6_offset += 3;
|
---|
| 633 | } else if ((lowpan6_buffer[1] & 0x03) == 0x03) {
|
---|
| 634 | /* DAM = 11, copy 1 byte (8bits) */
|
---|
| 635 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("DAM == 11, dst address form (8bits): ff02::00XX\n"));
|
---|
| 636 | ip6hdr->dest.addr[0] = PP_HTONL(0xff020000UL);
|
---|
| 637 | ip6hdr->dest.addr[1] = 0;
|
---|
| 638 | ip6hdr->dest.addr[2] = 0;
|
---|
| 639 | ip6hdr->dest.addr[3] = lwip_htonl(lowpan6_buffer[lowpan6_offset++]);
|
---|
| 640 | }
|
---|
| 641 |
|
---|
| 642 | } else {
|
---|
| 643 | /* no Multicast (M=0) */
|
---|
| 644 | if (lowpan6_buffer[1] & 0x04) {
|
---|
| 645 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("DAC == 1, stateful compression\n"));
|
---|
| 646 | /* Stateful destination compression */
|
---|
| 647 | /* Set prefix from context info */
|
---|
| 648 | if (lowpan6_buffer[1] & 0x80) {
|
---|
| 649 | i = lowpan6_buffer[2] & 0x0f;
|
---|
| 650 | } else {
|
---|
| 651 | i = 0;
|
---|
| 652 | }
|
---|
| 653 | if (i >= LWIP_6LOWPAN_NUM_CONTEXTS) {
|
---|
| 654 | /* Error */
|
---|
| 655 | return ERR_VAL;
|
---|
| 656 | }
|
---|
| 657 | #if LWIP_6LOWPAN_NUM_CONTEXTS > 0
|
---|
| 658 | ip6hdr->dest.addr[0] = lowpan6_contexts[i].addr[0];
|
---|
| 659 | ip6hdr->dest.addr[1] = lowpan6_contexts[i].addr[1];
|
---|
| 660 | #endif
|
---|
| 661 | } else {
|
---|
| 662 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("DAC == 0, stateless compression, setting link local prefix\n"));
|
---|
| 663 | /* Link local address compression */
|
---|
| 664 | ip6hdr->dest.addr[0] = PP_HTONL(0xfe800000UL);
|
---|
| 665 | ip6hdr->dest.addr[1] = 0;
|
---|
| 666 | }
|
---|
| 667 |
|
---|
| 668 | /* M=0, DAC=0, determining destination address length via DAM=xx */
|
---|
| 669 | if ((lowpan6_buffer[1] & 0x03) == 0x00) {
|
---|
| 670 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("DAM == 00, no dst compression, fetching 128bits inline"));
|
---|
| 671 | /* DAM=00, copy full address */
|
---|
| 672 | MEMCPY(&ip6hdr->dest.addr[0], lowpan6_buffer + lowpan6_offset, 16);
|
---|
| 673 | lowpan6_offset += 16;
|
---|
| 674 | } else if ((lowpan6_buffer[1] & 0x03) == 0x01) {
|
---|
| 675 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("DAM == 01, dst compression, 64bits inline\n"));
|
---|
| 676 | /* DAM=01, copy 64 inline bits, increase offset */
|
---|
| 677 | MEMCPY(&ip6hdr->dest.addr[2], lowpan6_buffer + lowpan6_offset, 8);
|
---|
| 678 | lowpan6_offset += 8;
|
---|
| 679 | } else if ((lowpan6_buffer[1] & 0x03) == 0x02) {
|
---|
| 680 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("DAM == 01, dst compression, 16bits inline\n"));
|
---|
| 681 | /* DAM=10, copy 16 inline bits, increase offset */
|
---|
| 682 | ip6hdr->dest.addr[2] = PP_HTONL(0x000000ffUL);
|
---|
| 683 | ip6hdr->dest.addr[3] = lwip_htonl(0xfe000000UL | (lowpan6_buffer[lowpan6_offset] << 8) | lowpan6_buffer[lowpan6_offset + 1]);
|
---|
| 684 | lowpan6_offset += 2;
|
---|
| 685 | } else if ((lowpan6_buffer[1] & 0x03) == 0x03) {
|
---|
| 686 | /* DAM=11, no bits available, use other headers (not done here) */
|
---|
| 687 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG,("DAM == 01, dst compression, 0bits inline, using other headers\n"));
|
---|
| 688 | if (dest->addr_len == 2) {
|
---|
| 689 | ip6hdr->dest.addr[2] = PP_HTONL(0x000000ffUL);
|
---|
| 690 | ip6hdr->dest.addr[3] = lwip_htonl(0xfe000000UL | (dest->addr[0] << 8) | dest->addr[1]);
|
---|
| 691 | } else if (dest->addr_len == 8) {
|
---|
| 692 | ip6hdr->dest.addr[2] = lwip_htonl(((dest->addr[0] ^ 2) << 24) | (dest->addr[1] << 16) | dest->addr[2] << 8 | dest->addr[3]);
|
---|
| 693 | ip6hdr->dest.addr[3] = lwip_htonl((dest->addr[4] << 24) | (dest->addr[5] << 16) | dest->addr[6] << 8 | dest->addr[7]);
|
---|
| 694 | } else {
|
---|
| 695 | /* invalid destination address length */
|
---|
| 696 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("Invalid destination address length\n"));
|
---|
| 697 | return ERR_VAL;
|
---|
| 698 | }
|
---|
| 699 | }
|
---|
| 700 | }
|
---|
| 701 |
|
---|
| 702 |
|
---|
| 703 | /* Next Header Compression (NHC) decoding? */
|
---|
| 704 | if (lowpan6_buffer[0] & 0x04) {
|
---|
| 705 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("NHC decoding\n"));
|
---|
| 706 | #if LWIP_UDP
|
---|
| 707 | if ((lowpan6_buffer[lowpan6_offset] & 0xf8) == 0xf0) {
|
---|
| 708 | /* NHC: UDP */
|
---|
| 709 | struct udp_hdr *udphdr;
|
---|
| 710 | LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("NHC: UDP\n"));
|
---|
| 711 |
|
---|
| 712 | /* UDP compression */
|
---|
| 713 | IP6H_NEXTH_SET(ip6hdr, IP6_NEXTH_UDP);
|
---|
| 714 | udphdr = (struct udp_hdr *)((u8_t *)decomp_buffer + ip6_offset);
|
---|
| 715 | if (decomp_bufsize < IP6_HLEN + UDP_HLEN) {
|
---|
| 716 | return ERR_MEM;
|
---|
| 717 | }
|
---|
| 718 |
|
---|
| 719 | /* Checksum decompression */
|
---|
| 720 | if (lowpan6_buffer[lowpan6_offset] & 0x04) {
|
---|
| 721 | /* @todo support checksum decompress */
|
---|
| 722 | LWIP_DEBUGF(LWIP_DBG_ON, ("NHC: UDP chechsum decompression UNSUPPORTED\n"));
|
---|
| 723 | return ERR_VAL;
|
---|
| 724 | }
|
---|
| 725 |
|
---|
| 726 | /* Decompress ports, according to RFC4944 */
|
---|
| 727 | i = lowpan6_buffer[lowpan6_offset++] & 0x03;
|
---|
| 728 | if (i == 0) {
|
---|
| 729 | udphdr->src = lwip_htons(lowpan6_buffer[lowpan6_offset] << 8 | lowpan6_buffer[lowpan6_offset + 1]);
|
---|
| 730 | udphdr->dest = lwip_htons(lowpan6_buffer[lowpan6_offset + 2] << 8 | lowpan6_buffer[lowpan6_offset + 3]);
|
---|
| 731 | lowpan6_offset += 4;
|
---|
| 732 | } else if (i == 0x01) {
|
---|
| 733 | udphdr->src = lwip_htons(lowpan6_buffer[lowpan6_offset] << 8 | lowpan6_buffer[lowpan6_offset + 1]);
|
---|
| 734 | udphdr->dest = lwip_htons(0xf000 | lowpan6_buffer[lowpan6_offset + 2]);
|
---|
| 735 | lowpan6_offset += 3;
|
---|
| 736 | } else if (i == 0x02) {
|
---|
| 737 | udphdr->src = lwip_htons(0xf000 | lowpan6_buffer[lowpan6_offset]);
|
---|
| 738 | udphdr->dest = lwip_htons(lowpan6_buffer[lowpan6_offset + 1] << 8 | lowpan6_buffer[lowpan6_offset + 2]);
|
---|
| 739 | lowpan6_offset += 3;
|
---|
| 740 | } else if (i == 0x03) {
|
---|
| 741 | udphdr->src = lwip_htons(0xf0b0 | ((lowpan6_buffer[lowpan6_offset] >> 4) & 0x0f));
|
---|
| 742 | udphdr->dest = lwip_htons(0xf0b0 | (lowpan6_buffer[lowpan6_offset] & 0x0f));
|
---|
| 743 | lowpan6_offset += 1;
|
---|
| 744 | }
|
---|
| 745 |
|
---|
| 746 | udphdr->chksum = lwip_htons(lowpan6_buffer[lowpan6_offset] << 8 | lowpan6_buffer[lowpan6_offset + 1]);
|
---|
| 747 | lowpan6_offset += 2;
|
---|
| 748 | ip6_offset += UDP_HLEN;
|
---|
| 749 | if (datagram_size == 0) {
|
---|
| 750 | datagram_size = compressed_size - lowpan6_offset + ip6_offset;
|
---|
| 751 | }
|
---|
| 752 | udphdr->len = lwip_htons(datagram_size - IP6_HLEN);
|
---|
| 753 |
|
---|
| 754 | } else
|
---|
| 755 | #endif /* LWIP_UDP */
|
---|
| 756 | {
|
---|
| 757 | LWIP_DEBUGF(LWIP_DBG_ON,("NHC: unsupported protocol!\n"));
|
---|
| 758 | /* @todo support NHC other than UDP */
|
---|
| 759 | return ERR_VAL;
|
---|
| 760 | }
|
---|
| 761 | }
|
---|
| 762 | if (datagram_size == 0) {
|
---|
| 763 | datagram_size = compressed_size - lowpan6_offset + ip6_offset;
|
---|
| 764 | }
|
---|
| 765 | /* Infer IPv6 payload length for header */
|
---|
| 766 | IP6H_PLEN_SET(ip6hdr, datagram_size - IP6_HLEN);
|
---|
| 767 |
|
---|
| 768 | if (lowpan6_offset > lowpan6_bufsize) {
|
---|
| 769 | /* input buffer overflow */
|
---|
| 770 | return ERR_VAL;
|
---|
| 771 | }
|
---|
| 772 | *hdr_size_comp = lowpan6_offset;
|
---|
| 773 | *hdr_size_decomp = ip6_offset;
|
---|
| 774 |
|
---|
| 775 | return ERR_OK;
|
---|
| 776 | }
|
---|
| 777 |
|
---|
| 778 | struct pbuf *
|
---|
| 779 | lowpan6_decompress(struct pbuf *p, u16_t datagram_size, ip6_addr_t *lowpan6_contexts,
|
---|
| 780 | struct lowpan6_link_addr *src, struct lowpan6_link_addr *dest)
|
---|
| 781 | {
|
---|
| 782 | struct pbuf *q;
|
---|
| 783 | u16_t lowpan6_offset, ip6_offset;
|
---|
| 784 | err_t err;
|
---|
| 785 |
|
---|
| 786 | #if LWIP_UDP
|
---|
| 787 | #define UDP_HLEN_ALLOC UDP_HLEN
|
---|
| 788 | #else
|
---|
| 789 | #define UDP_HLEN_ALLOC 0
|
---|
| 790 | #endif
|
---|
| 791 |
|
---|
| 792 | /* Allocate a buffer for decompression. This buffer will be too big and will be
|
---|
| 793 | trimmed once the final size is known. */
|
---|
| 794 | q = pbuf_alloc(PBUF_IP, p->len + IP6_HLEN + UDP_HLEN_ALLOC, PBUF_POOL);
|
---|
| 795 | if (q == NULL) {
|
---|
| 796 | pbuf_free(p);
|
---|
| 797 | return NULL;
|
---|
| 798 | }
|
---|
| 799 | if (q->len < IP6_HLEN + UDP_HLEN_ALLOC) {
|
---|
| 800 | /* The headers need to fit into the first pbuf */
|
---|
| 801 | pbuf_free(p);
|
---|
| 802 | pbuf_free(q);
|
---|
| 803 | return NULL;
|
---|
| 804 | }
|
---|
| 805 |
|
---|
| 806 | /* Decompress the IPv6 (and possibly UDP) header(s) into the new pbuf */
|
---|
| 807 | err = lowpan6_decompress_hdr((u8_t *)p->payload, p->len, (u8_t *)q->payload, q->len,
|
---|
| 808 | &lowpan6_offset, &ip6_offset, datagram_size, p->tot_len, lowpan6_contexts, src, dest);
|
---|
| 809 | if (err != ERR_OK) {
|
---|
| 810 | pbuf_free(p);
|
---|
| 811 | pbuf_free(q);
|
---|
| 812 | return NULL;
|
---|
| 813 | }
|
---|
| 814 |
|
---|
| 815 | /* Now we copy leftover contents from p to q, so we have all L2 and L3 headers
|
---|
| 816 | (and L4?) in a single pbuf: */
|
---|
| 817 |
|
---|
| 818 | /* Hide the compressed headers in p */
|
---|
| 819 | pbuf_remove_header(p, lowpan6_offset);
|
---|
| 820 | /* Temporarily hide the headers in q... */
|
---|
| 821 | pbuf_remove_header(q, ip6_offset);
|
---|
| 822 | /* ... copy the rest of p into q... */
|
---|
| 823 | pbuf_copy(q, p);
|
---|
| 824 | /* ... and reveal the headers again... */
|
---|
| 825 | pbuf_add_header_force(q, ip6_offset);
|
---|
| 826 | /* ... trim the pbuf to its correct size... */
|
---|
| 827 | pbuf_realloc(q, ip6_offset + p->len);
|
---|
| 828 | /* ... and cat possibly remaining (data-only) pbufs */
|
---|
| 829 | if (p->next != NULL) {
|
---|
| 830 | pbuf_cat(q, p->next);
|
---|
| 831 | }
|
---|
| 832 | /* the original (first) pbuf can now be freed */
|
---|
| 833 | p->next = NULL;
|
---|
| 834 | pbuf_free(p);
|
---|
| 835 |
|
---|
| 836 | /* all done */
|
---|
| 837 | return q;
|
---|
| 838 | }
|
---|
| 839 |
|
---|
| 840 | #endif /* LWIP_6LOWPAN_IPHC */
|
---|
| 841 | #endif /* LWIP_IPV6 */
|
---|