1/** 2 * @file 3 * 4 * 6LowPAN output 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.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/nd6.h" 60#include "lwip/mem.h" 61#include "lwip/udp.h" 62#include "lwip/tcpip.h" 63#include "lwip/snmp.h" 64#include "netif/ieee802154.h" 65 66#include <string.h> 67 68#if LWIP_6LOWPAN_802154_HW_CRC 69#define LWIP_6LOWPAN_DO_CALC_CRC(buf, len) 0 70#else 71#define LWIP_6LOWPAN_DO_CALC_CRC(buf, len) LWIP_6LOWPAN_CALC_CRC(buf, len) 72#endif 73 74/** This is a helper struct for reassembly of fragments 75 * (IEEE 802.15.4 limits to 127 bytes) 76 */ 77struct lowpan6_reass_helper { 78 struct lowpan6_reass_helper *next_packet; 79 struct pbuf *reass; 80 struct pbuf *frags; 81 u8_t timer; 82 struct lowpan6_link_addr sender_addr; 83 u16_t datagram_size; 84 u16_t datagram_tag; 85}; 86 87/** This struct keeps track of per-netif state */ 88struct lowpan6_ieee802154_data { 89 /** fragment reassembly list */ 90 struct lowpan6_reass_helper *reass_list; 91#if LWIP_6LOWPAN_NUM_CONTEXTS > 0 92 /** address context for compression */ 93 ip6_addr_t lowpan6_context[LWIP_6LOWPAN_NUM_CONTEXTS]; 94#endif 95 /** Datagram Tag for fragmentation */ 96 u16_t tx_datagram_tag; 97 /** local PAN ID for IEEE 802.15.4 header */ 98 u16_t ieee_802154_pan_id; 99 /** Sequence Number for IEEE 802.15.4 transmission */ 100 u8_t tx_frame_seq_num; 101}; 102 103/* Maximum frame size is 127 bytes minus CRC size */ 104#define LOWPAN6_MAX_PAYLOAD (127 - 2) 105 106/** Currently, this state is global, since there's only one 6LoWPAN netif */ 107static struct lowpan6_ieee802154_data lowpan6_data; 108 109#if LWIP_6LOWPAN_NUM_CONTEXTS > 0 110#define LWIP_6LOWPAN_CONTEXTS(netif) lowpan6_data.lowpan6_context 111#else 112#define LWIP_6LOWPAN_CONTEXTS(netif) NULL 113#endif 114 115static const struct lowpan6_link_addr ieee_802154_broadcast = {2, {0xff, 0xff}}; 116 117#if LWIP_6LOWPAN_INFER_SHORT_ADDRESS 118static struct lowpan6_link_addr short_mac_addr = {2, {0, 0}}; 119#endif /* LWIP_6LOWPAN_INFER_SHORT_ADDRESS */ 120 121/* IEEE 802.15.4 specific functions: */ 122 123/** Write the IEEE 802.15.4 header that encapsulates the 6LoWPAN frame. 124 * Src and dst PAN IDs are filled with the ID set by @ref lowpan6_set_pan_id. 125 * 126 * Since the length is variable: 127 * @returns the header length 128 */ 129static u8_t 130lowpan6_write_iee802154_header(struct ieee_802154_hdr *hdr, const struct lowpan6_link_addr *src, 131 const struct lowpan6_link_addr *dst) 132{ 133 u8_t ieee_header_len; 134 u8_t *buffer; 135 u8_t i; 136 u16_t fc; 137 138 fc = IEEE_802154_FC_FT_DATA; /* send data packet (2003 frame version) */ 139 fc |= IEEE_802154_FC_PANID_COMPR; /* set PAN ID compression, for now src and dst PANs are equal */ 140 if (dst != &ieee_802154_broadcast) { 141 fc |= IEEE_802154_FC_ACK_REQ; /* data packet, no broadcast: ack required. */ 142 } 143 if (dst->addr_len == 2) { 144 fc |= IEEE_802154_FC_DST_ADDR_MODE_SHORT; 145 } else { 146 LWIP_ASSERT("invalid dst address length", dst->addr_len == 8); 147 fc |= IEEE_802154_FC_DST_ADDR_MODE_EXT; 148 } 149 if (src->addr_len == 2) { 150 fc |= IEEE_802154_FC_SRC_ADDR_MODE_SHORT; 151 } else { 152 LWIP_ASSERT("invalid src address length", src->addr_len == 8); 153 fc |= IEEE_802154_FC_SRC_ADDR_MODE_EXT; 154 } 155 hdr->frame_control = fc; 156 hdr->sequence_number = lowpan6_data.tx_frame_seq_num++; 157 hdr->destination_pan_id = lowpan6_data.ieee_802154_pan_id; /* pan id */ 158 159 buffer = (u8_t *)hdr; 160 ieee_header_len = 5; 161 i = dst->addr_len; 162 /* reverse memcpy of dst addr */ 163 while (i-- > 0) { 164 buffer[ieee_header_len++] = dst->addr[i]; 165 } 166 /* Source PAN ID skipped due to PAN ID Compression */ 167 i = src->addr_len; 168 /* reverse memcpy of src addr */ 169 while (i-- > 0) { 170 buffer[ieee_header_len++] = src->addr[i]; 171 } 172 return ieee_header_len; 173} 174 175/** Parse the IEEE 802.15.4 header from a pbuf. 176 * If successful, the header is hidden from the pbuf. 177 * 178 * PAN IDs and seuqence number are not checked 179 * 180 * @param p input pbuf, p->payload pointing at the IEEE 802.15.4 header 181 * @param src pointer to source address filled from the header 182 * @param dest pointer to destination address filled from the header 183 * @returns ERR_OK if successful 184 */ 185static err_t 186lowpan6_parse_iee802154_header(struct pbuf *p, struct lowpan6_link_addr *src, 187 struct lowpan6_link_addr *dest) 188{ 189 u8_t *puc; 190 s8_t i; 191 u16_t frame_control, addr_mode; 192 u16_t datagram_offset; 193 194 /* Parse IEEE 802.15.4 header */ 195 puc = (u8_t *)p->payload; 196 frame_control = puc[0] | (puc[1] << 8); 197 datagram_offset = 2; 198 if (frame_control & IEEE_802154_FC_SEQNO_SUPPR) { 199 if (IEEE_802154_FC_FRAME_VERSION_GET(frame_control) <= 1) { 200 /* sequence number suppressed, this is not valid for versions 0/1 */ 201 return ERR_VAL; 202 } 203 } else { 204 datagram_offset++; 205 } 206 datagram_offset += 2; /* Skip destination PAN ID */ 207 addr_mode = frame_control & IEEE_802154_FC_DST_ADDR_MODE_MASK; 208 if (addr_mode == IEEE_802154_FC_DST_ADDR_MODE_EXT) { 209 /* extended address (64 bit) */ 210 dest->addr_len = 8; 211 /* reverse memcpy: */ 212 for (i = 0; i < 8; i++) { 213 dest->addr[i] = puc[datagram_offset + 7 - i]; 214 } 215 datagram_offset += 8; 216 } else if (addr_mode == IEEE_802154_FC_DST_ADDR_MODE_SHORT) { 217 /* short address (16 bit) */ 218 dest->addr_len = 2; 219 /* reverse memcpy: */ 220 dest->addr[0] = puc[datagram_offset + 1]; 221 dest->addr[1] = puc[datagram_offset]; 222 datagram_offset += 2; 223 } else { 224 /* unsupported address mode (do we need "no address"?) */ 225 return ERR_VAL; 226 } 227 228 if (!(frame_control & IEEE_802154_FC_PANID_COMPR)) { 229 /* No PAN ID compression, skip source PAN ID */ 230 datagram_offset += 2; 231 } 232 233 addr_mode = frame_control & IEEE_802154_FC_SRC_ADDR_MODE_MASK; 234 if (addr_mode == IEEE_802154_FC_SRC_ADDR_MODE_EXT) { 235 /* extended address (64 bit) */ 236 src->addr_len = 8; 237 /* reverse memcpy: */ 238 for (i = 0; i < 8; i++) { 239 src->addr[i] = puc[datagram_offset + 7 - i]; 240 } 241 datagram_offset += 8; 242 } else if (addr_mode == IEEE_802154_FC_DST_ADDR_MODE_SHORT) { 243 /* short address (16 bit) */ 244 src->addr_len = 2; 245 src->addr[0] = puc[datagram_offset + 1]; 246 src->addr[1] = puc[datagram_offset]; 247 datagram_offset += 2; 248 } else { 249 /* unsupported address mode (do we need "no address"?) */ 250 return ERR_VAL; 251 } 252 253 /* hide IEEE802.15.4 header. */ 254 if (pbuf_remove_header(p, datagram_offset)) { 255 return ERR_VAL; 256 } 257 return ERR_OK; 258} 259 260/** Calculate the 16-bit CRC as required by IEEE 802.15.4 */ 261u16_t 262lowpan6_calc_crc(const void* buf, u16_t len) 263{ 264#define CCITT_POLY_16 0x8408U 265 u16_t i; 266 u8_t b; 267 u16_t crc = 0; 268 const u8_t* p = (const u8_t*)buf; 269 270 for (i = 0; i < len; i++) { 271 u8_t data = *p; 272 for (b = 0U; b < 8U; b++) { 273 if (((data ^ crc) & 1) != 0) { 274 crc = (u16_t)((crc >> 1) ^ CCITT_POLY_16); 275 } else { 276 crc = (u16_t)(crc >> 1); 277 } 278 data = (u8_t)(data >> 1); 279 } 280 p++; 281 } 282 return crc; 283} 284 285/* Fragmentation specific functions: */ 286 287static void 288free_reass_datagram(struct lowpan6_reass_helper *lrh) 289{ 290 if (lrh->reass) { 291 pbuf_free(lrh->reass); 292 } 293 if (lrh->frags) { 294 pbuf_free(lrh->frags); 295 } 296 mem_free(lrh); 297} 298 299/** 300 * Removes a datagram from the reassembly queue. 301 **/ 302static void 303dequeue_datagram(struct lowpan6_reass_helper *lrh, struct lowpan6_reass_helper *prev) 304{ 305 if (lowpan6_data.reass_list == lrh) { 306 lowpan6_data.reass_list = lowpan6_data.reass_list->next_packet; 307 } else { 308 /* it wasn't the first, so it must have a valid 'prev' */ 309 LWIP_ASSERT("sanity check linked list", prev != NULL); 310 prev->next_packet = lrh->next_packet; 311 } 312} 313 314/** 315 * Periodic timer for 6LowPAN functions: 316 * 317 * - Remove incomplete/old packets 318 */ 319void 320lowpan6_tmr(void) 321{ 322 struct lowpan6_reass_helper *lrh, *lrh_next, *lrh_prev = NULL; 323 324 lrh = lowpan6_data.reass_list; 325 while (lrh != NULL) { 326 lrh_next = lrh->next_packet; 327 if ((--lrh->timer) == 0) { 328 dequeue_datagram(lrh, lrh_prev); 329 free_reass_datagram(lrh); 330 } else { 331 lrh_prev = lrh; 332 } 333 lrh = lrh_next; 334 } 335} 336 337/* 338 * Encapsulates data into IEEE 802.15.4 frames. 339 * Fragments an IPv6 datagram into 6LowPAN units, which fit into IEEE 802.15.4 frames. 340 * If configured, will compress IPv6 and or UDP headers. 341 * */ 342static err_t 343lowpan6_frag(struct netif *netif, struct pbuf *p, const struct lowpan6_link_addr *src, const struct lowpan6_link_addr *dst) 344{ 345 struct pbuf *p_frag; 346 u16_t frag_len, remaining_len, max_data_len; 347 u8_t *buffer; 348 u8_t ieee_header_len; 349 u8_t lowpan6_header_len; 350 u8_t hidden_header_len; 351 u16_t crc; 352 u16_t datagram_offset; 353 err_t err = ERR_IF; 354 355 LWIP_ASSERT("lowpan6_frag: netif->linkoutput not set", netif->linkoutput != NULL); 356 357 /* We'll use a dedicated pbuf for building 6LowPAN fragments. */ 358 p_frag = pbuf_alloc(PBUF_RAW, 127, PBUF_RAM); 359 if (p_frag == NULL) { 360 MIB2_STATS_NETIF_INC(netif, ifoutdiscards); 361 return ERR_MEM; 362 } 363 LWIP_ASSERT("this needs a pbuf in one piece", p_frag->len == p_frag->tot_len); 364 365 /* Write IEEE 802.15.4 header. */ 366 buffer = (u8_t *)p_frag->payload; 367 ieee_header_len = lowpan6_write_iee802154_header((struct ieee_802154_hdr *)buffer, src, dst); 368 LWIP_ASSERT("ieee_header_len < p_frag->len", ieee_header_len < p_frag->len); 369 370#if LWIP_6LOWPAN_IPHC 371 /* Perform 6LowPAN IPv6 header compression according to RFC 6282 */ 372 /* do the header compression (this does NOT copy any non-compressed data) */ 373 err = lowpan6_compress_headers(netif, (u8_t *)p->payload, p->len, 374 &buffer[ieee_header_len], p_frag->len - ieee_header_len, &lowpan6_header_len, 375 &hidden_header_len, LWIP_6LOWPAN_CONTEXTS(netif), src, dst); 376 if (err != ERR_OK) { 377 MIB2_STATS_NETIF_INC(netif, ifoutdiscards); 378 pbuf_free(p_frag); 379 return err; 380 } 381 pbuf_remove_header(p, hidden_header_len); 382 383#else /* LWIP_6LOWPAN_IPHC */ 384 /* Send uncompressed IPv6 header with appropriate dispatch byte. */ 385 lowpan6_header_len = 1; 386 buffer[ieee_header_len] = 0x41; /* IPv6 dispatch */ 387#endif /* LWIP_6LOWPAN_IPHC */ 388 389 /* Calculate remaining packet length */ 390 remaining_len = p->tot_len; 391 392 if (remaining_len > 0x7FF) { 393 MIB2_STATS_NETIF_INC(netif, ifoutdiscards); 394 /* datagram_size must fit into 11 bit */ 395 pbuf_free(p_frag); 396 return ERR_VAL; 397 } 398 399 /* Fragment, or 1 packet? */ 400 max_data_len = LOWPAN6_MAX_PAYLOAD - ieee_header_len - lowpan6_header_len; 401 if (remaining_len > max_data_len) { 402 u16_t data_len; 403 /* We must move the 6LowPAN header to make room for the FRAG header. */ 404 memmove(&buffer[ieee_header_len + 4], &buffer[ieee_header_len], lowpan6_header_len); 405 406 /* Now we need to fragment the packet. FRAG1 header first */ 407 buffer[ieee_header_len] = 0xc0 | (((p->tot_len + hidden_header_len) >> 8) & 0x7); 408 buffer[ieee_header_len + 1] = (p->tot_len + hidden_header_len) & 0xff; 409 410 lowpan6_data.tx_datagram_tag++; 411 buffer[ieee_header_len + 2] = (lowpan6_data.tx_datagram_tag >> 8) & 0xff; 412 buffer[ieee_header_len + 3] = lowpan6_data.tx_datagram_tag & 0xff; 413 414 /* Fragment follows. */ 415 data_len = (max_data_len - 4) & 0xf8; 416 frag_len = data_len + lowpan6_header_len; 417 418 pbuf_copy_partial(p, buffer + ieee_header_len + lowpan6_header_len + 4, frag_len - lowpan6_header_len, 0); 419 remaining_len -= frag_len - lowpan6_header_len; 420 /* datagram offset holds the offset before compression */ 421 datagram_offset = frag_len - lowpan6_header_len + hidden_header_len; 422 LWIP_ASSERT("datagram offset must be a multiple of 8", (datagram_offset & 7) == 0); 423 424 /* Calculate frame length */ 425 p_frag->len = p_frag->tot_len = ieee_header_len + 4 + frag_len + 2; /* add 2 bytes for crc*/ 426 427 /* 2 bytes CRC */ 428 crc = LWIP_6LOWPAN_DO_CALC_CRC(p_frag->payload, p_frag->len - 2); 429 pbuf_take_at(p_frag, &crc, 2, p_frag->len - 2); 430 431 /* send the packet */ 432 MIB2_STATS_NETIF_ADD(netif, ifoutoctets, p_frag->tot_len); 433 LWIP_DEBUGF(LWIP_LOWPAN6_DEBUG | LWIP_DBG_TRACE, ("lowpan6_send: sending packet %p\n", (void *)p)); 434 err = netif->linkoutput(netif, p_frag); 435 436 while ((remaining_len > 0) && (err == ERR_OK)) { 437 struct ieee_802154_hdr *hdr = (struct ieee_802154_hdr *)buffer; 438 /* new frame, new seq num for ACK */ 439 hdr->sequence_number = lowpan6_data.tx_frame_seq_num++; 440 441 buffer[ieee_header_len] |= 0x20; /* Change FRAG1 to FRAGN */ 442 443 LWIP_ASSERT("datagram offset must be a multiple of 8", (datagram_offset & 7) == 0); 444 buffer[ieee_header_len + 4] = (u8_t)(datagram_offset >> 3); /* datagram offset in FRAGN header (datagram_offset is max. 11 bit) */ 445 446 frag_len = (127 - ieee_header_len - 5 - 2) & 0xf8; 447 if (frag_len > remaining_len) { 448 frag_len = remaining_len; 449 } 450 451 pbuf_copy_partial(p, buffer + ieee_header_len + 5, frag_len, p->tot_len - remaining_len); 452 remaining_len -= frag_len; 453 datagram_offset += frag_len; 454 455 /* Calculate frame length */ 456 p_frag->len = p_frag->tot_len = frag_len + 5 + ieee_header_len + 2; 457 458 /* 2 bytes CRC */ 459 crc = LWIP_6LOWPAN_DO_CALC_CRC(p_frag->payload, p_frag->len - 2); 460 pbuf_take_at(p_frag, &crc, 2, p_frag->len - 2); 461 462 /* send the packet */ 463 MIB2_STATS_NETIF_ADD(netif, ifoutoctets, p_frag->tot_len); 464 LWIP_DEBUGF(LWIP_LOWPAN6_DEBUG | LWIP_DBG_TRACE, ("lowpan6_send: sending packet %p\n", (void *)p)); 465 err = netif->linkoutput(netif, p_frag); 466 } 467 } else { 468 /* It fits in one frame. */ 469 frag_len = remaining_len; 470 471 /* Copy IPv6 packet */ 472 pbuf_copy_partial(p, buffer + ieee_header_len + lowpan6_header_len, frag_len, 0); 473 remaining_len = 0; 474 475 /* Calculate frame length */ 476 p_frag->len = p_frag->tot_len = frag_len + lowpan6_header_len + ieee_header_len + 2; 477 LWIP_ASSERT("", p_frag->len <= 127); 478 479 /* 2 bytes CRC */ 480 crc = LWIP_6LOWPAN_DO_CALC_CRC(p_frag->payload, p_frag->len - 2); 481 pbuf_take_at(p_frag, &crc, 2, p_frag->len - 2); 482 483 /* send the packet */ 484 MIB2_STATS_NETIF_ADD(netif, ifoutoctets, p_frag->tot_len); 485 LWIP_DEBUGF(LWIP_LOWPAN6_DEBUG | LWIP_DBG_TRACE, ("lowpan6_send: sending packet %p\n", (void *)p)); 486 err = netif->linkoutput(netif, p_frag); 487 } 488 489 pbuf_free(p_frag); 490 491 return err; 492} 493 494/** 495 * @ingroup sixlowpan 496 * Set context 497 */ 498err_t 499lowpan6_set_context(u8_t idx, const ip6_addr_t *context) 500{ 501#if LWIP_6LOWPAN_NUM_CONTEXTS > 0 502 if (idx >= LWIP_6LOWPAN_NUM_CONTEXTS) { 503 return ERR_ARG; 504 } 505 506 IP6_ADDR_ZONECHECK(context); 507 508 ip6_addr_set(&lowpan6_data.lowpan6_context[idx], context); 509 510 return ERR_OK; 511#else 512 LWIP_UNUSED_ARG(idx); 513 LWIP_UNUSED_ARG(context); 514 return ERR_ARG; 515#endif 516} 517 518#if LWIP_6LOWPAN_INFER_SHORT_ADDRESS 519/** 520 * @ingroup sixlowpan 521 * Set short address 522 */ 523err_t 524lowpan6_set_short_addr(u8_t addr_high, u8_t addr_low) 525{ 526 short_mac_addr.addr[0] = addr_high; 527 short_mac_addr.addr[1] = addr_low; 528 529 return ERR_OK; 530} 531#endif /* LWIP_6LOWPAN_INFER_SHORT_ADDRESS */ 532 533/* Create IEEE 802.15.4 address from netif address */ 534static err_t 535lowpan6_hwaddr_to_addr(struct netif *netif, struct lowpan6_link_addr *addr) 536{ 537 addr->addr_len = 8; 538 if (netif->hwaddr_len == 8) { 539 LWIP_ERROR("NETIF_MAX_HWADDR_LEN >= 8 required", sizeof(netif->hwaddr) >= 8, return ERR_VAL;); 540 SMEMCPY(addr->addr, netif->hwaddr, 8); 541 } else if (netif->hwaddr_len == 6) { 542 /* Copy from MAC-48 */ 543 SMEMCPY(addr->addr, netif->hwaddr, 3); 544 addr->addr[3] = addr->addr[4] = 0xff; 545 SMEMCPY(&addr->addr[5], &netif->hwaddr[3], 3); 546 } else { 547 /* Invalid address length, don't know how to convert this */ 548 return ERR_VAL; 549 } 550 return ERR_OK; 551} 552 553/** 554 * @ingroup sixlowpan 555 * Resolve and fill-in IEEE 802.15.4 address header for outgoing IPv6 packet. 556 * 557 * Perform Header Compression and fragment if necessary. 558 * 559 * @param netif The lwIP network interface which the IP packet will be sent on. 560 * @param q The pbuf(s) containing the IP packet to be sent. 561 * @param ip6addr The IP address of the packet destination. 562 * 563 * @return err_t 564 */ 565err_t 566lowpan6_output(struct netif *netif, struct pbuf *q, const ip6_addr_t *ip6addr) 567{ 568 err_t result; 569 const u8_t *hwaddr; 570 struct lowpan6_link_addr src, dest; 571#if LWIP_6LOWPAN_INFER_SHORT_ADDRESS 572 ip6_addr_t ip6_src; 573 struct ip6_hdr *ip6_hdr; 574#endif /* LWIP_6LOWPAN_INFER_SHORT_ADDRESS */ 575 576#if LWIP_6LOWPAN_INFER_SHORT_ADDRESS 577 /* Check if we can compress source address (use aligned copy) */ 578 ip6_hdr = (struct ip6_hdr *)q->payload; 579 ip6_addr_copy_from_packed(ip6_src, ip6_hdr->src); 580 ip6_addr_assign_zone(&ip6_src, IP6_UNICAST, netif); 581 if (lowpan6_get_address_mode(&ip6_src, &short_mac_addr) == 3) { 582 src.addr_len = 2; 583 src.addr[0] = short_mac_addr.addr[0]; 584 src.addr[1] = short_mac_addr.addr[1]; 585 } else 586#endif /* LWIP_6LOWPAN_INFER_SHORT_ADDRESS */ 587 { 588 result = lowpan6_hwaddr_to_addr(netif, &src); 589 if (result != ERR_OK) { 590 MIB2_STATS_NETIF_INC(netif, ifoutdiscards); 591 return result; 592 } 593 } 594 595 /* multicast destination IP address? */ 596 if (ip6_addr_ismulticast(ip6addr)) { 597 MIB2_STATS_NETIF_INC(netif, ifoutnucastpkts); 598 /* We need to send to the broadcast address.*/ 599 return lowpan6_frag(netif, q, &src, &ieee_802154_broadcast); 600 } 601 602 /* We have a unicast destination IP address */ 603 /* @todo anycast? */ 604 605#if LWIP_6LOWPAN_INFER_SHORT_ADDRESS 606 if (src.addr_len == 2) { 607 /* If source address was compressable to short_mac_addr, and dest has same subnet and 608 * is also compressable to 2-bytes, assume we can infer dest as a short address too. */ 609 dest.addr_len = 2; 610 dest.addr[0] = ((u8_t *)q->payload)[38]; 611 dest.addr[1] = ((u8_t *)q->payload)[39]; 612 if ((src.addr_len == 2) && (ip6_addr_netcmp_zoneless(&ip6_hdr->src, &ip6_hdr->dest)) && 613 (lowpan6_get_address_mode(ip6addr, &dest) == 3)) { 614 MIB2_STATS_NETIF_INC(netif, ifoutucastpkts); 615 return lowpan6_frag(netif, q, &src, &dest); 616 } 617 } 618#endif /* LWIP_6LOWPAN_INFER_SHORT_ADDRESS */ 619 620 /* Ask ND6 what to do with the packet. */ 621 result = nd6_get_next_hop_addr_or_queue(netif, q, ip6addr, &hwaddr); 622 if (result != ERR_OK) { 623 MIB2_STATS_NETIF_INC(netif, ifoutdiscards); 624 return result; 625 } 626 627 /* If no hardware address is returned, nd6 has queued the packet for later. */ 628 if (hwaddr == NULL) { 629 return ERR_OK; 630 } 631 632 /* Send out the packet using the returned hardware address. */ 633 dest.addr_len = netif->hwaddr_len; 634 /* XXX: Inferring the length of the source address from the destination address 635 * is not correct for IEEE 802.15.4, but currently we don't get this information 636 * from the neighbor cache */ 637 SMEMCPY(dest.addr, hwaddr, netif->hwaddr_len); 638 MIB2_STATS_NETIF_INC(netif, ifoutucastpkts); 639 return lowpan6_frag(netif, q, &src, &dest); 640} 641/** 642 * @ingroup sixlowpan 643 * NETIF input function: don't free the input pbuf when returning != ERR_OK! 644 */ 645err_t 646lowpan6_input(struct pbuf *p, struct netif *netif) 647{ 648 u8_t *puc, b; 649 s8_t i; 650 struct lowpan6_link_addr src, dest; 651 u16_t datagram_size = 0; 652 u16_t datagram_offset, datagram_tag; 653 struct lowpan6_reass_helper *lrh, *lrh_next, *lrh_prev = NULL; 654 655 if (p == NULL) { 656 return ERR_OK; 657 } 658 659 MIB2_STATS_NETIF_ADD(netif, ifinoctets, p->tot_len); 660 661 if (p->len != p->tot_len) { 662 /* for now, this needs a pbuf in one piece */ 663 goto lowpan6_input_discard; 664 } 665 666 if (lowpan6_parse_iee802154_header(p, &src, &dest) != ERR_OK) { 667 goto lowpan6_input_discard; 668 } 669 670 /* Check dispatch. */ 671 puc = (u8_t *)p->payload; 672 673 b = *puc; 674 if ((b & 0xf8) == 0xc0) { 675 /* FRAG1 dispatch. add this packet to reassembly list. */ 676 datagram_size = ((u16_t)(puc[0] & 0x07) << 8) | (u16_t)puc[1]; 677 datagram_tag = ((u16_t)puc[2] << 8) | (u16_t)puc[3]; 678 679 /* check for duplicate */ 680 lrh = lowpan6_data.reass_list; 681 while (lrh != NULL) { 682 uint8_t discard = 0; 683 lrh_next = lrh->next_packet; 684 if ((lrh->sender_addr.addr_len == src.addr_len) && 685 (memcmp(lrh->sender_addr.addr, src.addr, src.addr_len) == 0)) { 686 /* address match with packet in reassembly. */ 687 if ((datagram_tag == lrh->datagram_tag) && (datagram_size == lrh->datagram_size)) { 688 /* duplicate fragment. */ 689 goto lowpan6_input_discard; 690 } else { 691 /* We are receiving the start of a new datagram. Discard old one (incomplete). */ 692 discard = 1; 693 } 694 } 695 if (discard) { 696 dequeue_datagram(lrh, lrh_prev); 697 free_reass_datagram(lrh); 698 } else { 699 lrh_prev = lrh; 700 } 701 /* Check next datagram in queue. */ 702 lrh = lrh_next; 703 } 704 705 pbuf_remove_header(p, 4); /* hide frag1 dispatch */ 706 707 lrh = (struct lowpan6_reass_helper *) mem_malloc(sizeof(struct lowpan6_reass_helper)); 708 if (lrh == NULL) { 709 goto lowpan6_input_discard; 710 } 711 712 lrh->sender_addr.addr_len = src.addr_len; 713 for (i = 0; i < src.addr_len; i++) { 714 lrh->sender_addr.addr[i] = src.addr[i]; 715 } 716 lrh->datagram_size = datagram_size; 717 lrh->datagram_tag = datagram_tag; 718 lrh->frags = NULL; 719 if (*(u8_t *)p->payload == 0x41) { 720 /* This is a complete IPv6 packet, just skip dispatch byte. */ 721 pbuf_remove_header(p, 1); /* hide dispatch byte. */ 722 lrh->reass = p; 723 } else if ((*(u8_t *)p->payload & 0xe0 ) == 0x60) { 724 lrh->reass = lowpan6_decompress(p, datagram_size, LWIP_6LOWPAN_CONTEXTS(netif), &src, &dest); 725 if (lrh->reass == NULL) { 726 /* decompression failed */ 727 mem_free(lrh); 728 goto lowpan6_input_discard; 729 } 730 } 731 /* TODO: handle the case where we already have FRAGN received */ 732 lrh->next_packet = lowpan6_data.reass_list; 733 lrh->timer = 2; 734 lowpan6_data.reass_list = lrh; 735 736 return ERR_OK; 737 } else if ((b & 0xf8) == 0xe0) { 738 /* FRAGN dispatch, find packet being reassembled. */ 739 datagram_size = ((u16_t)(puc[0] & 0x07) << 8) | (u16_t)puc[1]; 740 datagram_tag = ((u16_t)puc[2] << 8) | (u16_t)puc[3]; 741 datagram_offset = (u16_t)puc[4] << 3; 742 pbuf_remove_header(p, 4); /* hide frag1 dispatch but keep datagram offset for reassembly */ 743 744 for (lrh = lowpan6_data.reass_list; lrh != NULL; lrh_prev = lrh, lrh = lrh->next_packet) { 745 if ((lrh->sender_addr.addr_len == src.addr_len) && 746 (memcmp(lrh->sender_addr.addr, src.addr, src.addr_len) == 0) && 747 (datagram_tag == lrh->datagram_tag) && 748 (datagram_size == lrh->datagram_size)) { 749 break; 750 } 751 } 752 if (lrh == NULL) { 753 /* rogue fragment */ 754 goto lowpan6_input_discard; 755 } 756 /* Insert new pbuf into list of fragments. Each fragment is a pbuf, 757 this only works for unchained pbufs. */ 758 LWIP_ASSERT("p->next == NULL", p->next == NULL); 759 if (lrh->reass != NULL) { 760 /* FRAG1 already received, check this offset against first len */ 761 if (datagram_offset < lrh->reass->len) { 762 /* fragment overlap, discard old fragments */ 763 dequeue_datagram(lrh, lrh_prev); 764 free_reass_datagram(lrh); 765 goto lowpan6_input_discard; 766 } 767 } 768 if (lrh->frags == NULL) { 769 /* first FRAGN */ 770 lrh->frags = p; 771 } else { 772 /* find the correct place to insert */ 773 struct pbuf *q, *last; 774 u16_t new_frag_len = p->len - 1; /* p->len includes datagram_offset byte */ 775 for (q = lrh->frags, last = NULL; q != NULL; last = q, q = q->next) { 776 u16_t q_datagram_offset = ((u8_t *)q->payload)[0] << 3; 777 u16_t q_frag_len = q->len - 1; 778 if (datagram_offset < q_datagram_offset) { 779 if (datagram_offset + new_frag_len > q_datagram_offset) { 780 /* overlap, discard old fragments */ 781 dequeue_datagram(lrh, lrh_prev); 782 free_reass_datagram(lrh); 783 goto lowpan6_input_discard; 784 } 785 /* insert here */ 786 break; 787 } else if (datagram_offset == q_datagram_offset) { 788 if (q_frag_len != new_frag_len) { 789 /* fragment mismatch, discard old fragments */ 790 dequeue_datagram(lrh, lrh_prev); 791 free_reass_datagram(lrh); 792 goto lowpan6_input_discard; 793 } 794 /* duplicate, ignore */ 795 pbuf_free(p); 796 return ERR_OK; 797 } 798 } 799 /* insert fragment */ 800 if (last == NULL) { 801 lrh->frags = p; 802 } else { 803 last->next = p; 804 p->next = q; 805 } 806 } 807 /* check if all fragments were received */ 808 if (lrh->reass) { 809 u16_t offset = lrh->reass->len; 810 struct pbuf *q; 811 for (q = lrh->frags; q != NULL; q = q->next) { 812 u16_t q_datagram_offset = ((u8_t *)q->payload)[0] << 3; 813 if (q_datagram_offset != offset) { 814 /* not complete, wait for more fragments */ 815 return ERR_OK; 816 } 817 offset += q->len - 1; 818 } 819 if (offset == datagram_size) { 820 /* all fragments received, combine pbufs */ 821 u16_t datagram_left = datagram_size - lrh->reass->len; 822 for (q = lrh->frags; q != NULL; q = q->next) { 823 /* hide datagram_offset byte now */ 824 pbuf_remove_header(q, 1); 825 q->tot_len = datagram_left; 826 datagram_left -= q->len; 827 } 828 LWIP_ASSERT("datagram_left == 0", datagram_left == 0); 829 q = lrh->reass; 830 q->tot_len = datagram_size; 831 q->next = lrh->frags; 832 lrh->frags = NULL; 833 lrh->reass = NULL; 834 dequeue_datagram(lrh, lrh_prev); 835 mem_free(lrh); 836 837 /* @todo: distinguish unicast/multicast */ 838 MIB2_STATS_NETIF_INC(netif, ifinucastpkts); 839 return ip6_input(q, netif); 840 } 841 } 842 /* pbuf enqueued, waiting for more fragments */ 843 return ERR_OK; 844 } else { 845 if (b == 0x41) { 846 /* This is a complete IPv6 packet, just skip dispatch byte. */ 847 pbuf_remove_header(p, 1); /* hide dispatch byte. */ 848 } else if ((b & 0xe0 ) == 0x60) { 849 /* IPv6 headers are compressed using IPHC. */ 850 p = lowpan6_decompress(p, datagram_size, LWIP_6LOWPAN_CONTEXTS(netif), &src, &dest); 851 if (p == NULL) { 852 MIB2_STATS_NETIF_INC(netif, ifindiscards); 853 return ERR_OK; 854 } 855 } else { 856 goto lowpan6_input_discard; 857 } 858 859 /* @todo: distinguish unicast/multicast */ 860 MIB2_STATS_NETIF_INC(netif, ifinucastpkts); 861 862 return ip6_input(p, netif); 863 } 864lowpan6_input_discard: 865 MIB2_STATS_NETIF_INC(netif, ifindiscards); 866 pbuf_free(p); 867 /* always return ERR_OK here to prevent the caller freeing the pbuf */ 868 return ERR_OK; 869} 870 871/** 872 * @ingroup sixlowpan 873 */ 874err_t 875lowpan6_if_init(struct netif *netif) 876{ 877 netif->name[0] = 'L'; 878 netif->name[1] = '6'; 879 netif->output_ip6 = lowpan6_output; 880 881 MIB2_INIT_NETIF(netif, snmp_ifType_other, 0); 882 883 /* maximum transfer unit */ 884 netif->mtu = 1280; 885 886 /* broadcast capability */ 887 netif->flags = NETIF_FLAG_BROADCAST /* | NETIF_FLAG_LOWPAN6 */; 888 889 return ERR_OK; 890} 891 892/** 893 * @ingroup sixlowpan 894 * Set PAN ID 895 */ 896err_t 897lowpan6_set_pan_id(u16_t pan_id) 898{ 899 lowpan6_data.ieee_802154_pan_id = pan_id; 900 901 return ERR_OK; 902} 903 904#if !NO_SYS 905/** 906 * @ingroup sixlowpan 907 * Pass a received packet to tcpip_thread for input processing 908 * 909 * @param p the received packet, p->payload pointing to the 910 * IEEE 802.15.4 header. 911 * @param inp the network interface on which the packet was received 912 */ 913err_t 914tcpip_6lowpan_input(struct pbuf *p, struct netif *inp) 915{ 916 return tcpip_inpkt(p, inp, lowpan6_input); 917} 918#endif /* !NO_SYS */ 919 920#endif /* LWIP_IPV6 */ 921