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Diffstat (limited to 'lwip/src/netif/lowpan6.c')
| -rw-r--r-- | lwip/src/netif/lowpan6.c | 920 |
1 files changed, 920 insertions, 0 deletions
diff --git a/lwip/src/netif/lowpan6.c b/lwip/src/netif/lowpan6.c new file mode 100644 index 0000000..7f0d276 --- /dev/null +++ b/lwip/src/netif/lowpan6.c @@ -0,0 +1,920 @@ +/** + * @file + * + * 6LowPAN output for IPv6. Uses ND tables for link-layer addressing. Fragments packets to 6LowPAN units. + * + * This implementation aims to conform to IEEE 802.15.4(-2015), RFC 4944 and RFC 6282. + * @todo: RFC 6775. + */ + +/* + * Copyright (c) 2015 Inico Technologies Ltd. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * This file is part of the lwIP TCP/IP stack. + * + * Author: Ivan Delamer <delamer@inicotech.com> + * + * + * Please coordinate changes and requests with Ivan Delamer + * <delamer@inicotech.com> + */ + +/** + * @defgroup sixlowpan 6LoWPAN (RFC4944) + * @ingroup netifs + * 6LowPAN netif implementation + */ + +#include "netif/lowpan6.h" + +#if LWIP_IPV6 + +#include "lwip/ip.h" +#include "lwip/pbuf.h" +#include "lwip/ip_addr.h" +#include "lwip/netif.h" +#include "lwip/nd6.h" +#include "lwip/mem.h" +#include "lwip/udp.h" +#include "lwip/tcpip.h" +#include "lwip/snmp.h" +#include "netif/ieee802154.h" + +#include <string.h> + +#if LWIP_6LOWPAN_802154_HW_CRC +#define LWIP_6LOWPAN_DO_CALC_CRC(buf, len) 0 +#else +#define LWIP_6LOWPAN_DO_CALC_CRC(buf, len) LWIP_6LOWPAN_CALC_CRC(buf, len) +#endif + +/** This is a helper struct for reassembly of fragments + * (IEEE 802.15.4 limits to 127 bytes) + */ +struct lowpan6_reass_helper { + struct lowpan6_reass_helper *next_packet; + struct pbuf *reass; + struct pbuf *frags; + u8_t timer; + struct lowpan6_link_addr sender_addr; + u16_t datagram_size; + u16_t datagram_tag; +}; + +/** This struct keeps track of per-netif state */ +struct lowpan6_ieee802154_data { + /** fragment reassembly list */ + struct lowpan6_reass_helper *reass_list; +#if LWIP_6LOWPAN_NUM_CONTEXTS > 0 + /** address context for compression */ + ip6_addr_t lowpan6_context[LWIP_6LOWPAN_NUM_CONTEXTS]; +#endif + /** Datagram Tag for fragmentation */ + u16_t tx_datagram_tag; + /** local PAN ID for IEEE 802.15.4 header */ + u16_t ieee_802154_pan_id; + /** Sequence Number for IEEE 802.15.4 transmission */ + u8_t tx_frame_seq_num; +}; + +/* Maximum frame size is 127 bytes minus CRC size */ +#define LOWPAN6_MAX_PAYLOAD (127 - 2) + +/** Currently, this state is global, since there's only one 6LoWPAN netif */ +static struct lowpan6_ieee802154_data lowpan6_data; + +#if LWIP_6LOWPAN_NUM_CONTEXTS > 0 +#define LWIP_6LOWPAN_CONTEXTS(netif) lowpan6_data.lowpan6_context +#else +#define LWIP_6LOWPAN_CONTEXTS(netif) NULL +#endif + +static const struct lowpan6_link_addr ieee_802154_broadcast = {2, {0xff, 0xff}}; + +#if LWIP_6LOWPAN_INFER_SHORT_ADDRESS +static struct lowpan6_link_addr short_mac_addr = {2, {0, 0}}; +#endif /* LWIP_6LOWPAN_INFER_SHORT_ADDRESS */ + +/* IEEE 802.15.4 specific functions: */ + +/** Write the IEEE 802.15.4 header that encapsulates the 6LoWPAN frame. + * Src and dst PAN IDs are filled with the ID set by @ref lowpan6_set_pan_id. + * + * Since the length is variable: + * @returns the header length + */ +static u8_t +lowpan6_write_iee802154_header(struct ieee_802154_hdr *hdr, const struct lowpan6_link_addr *src, + const struct lowpan6_link_addr *dst) +{ + u8_t ieee_header_len; + u8_t *buffer; + u8_t i; + u16_t fc; + + fc = IEEE_802154_FC_FT_DATA; /* send data packet (2003 frame version) */ + fc |= IEEE_802154_FC_PANID_COMPR; /* set PAN ID compression, for now src and dst PANs are equal */ + if (dst != &ieee_802154_broadcast) { + fc |= IEEE_802154_FC_ACK_REQ; /* data packet, no broadcast: ack required. */ + } + if (dst->addr_len == 2) { + fc |= IEEE_802154_FC_DST_ADDR_MODE_SHORT; + } else { + LWIP_ASSERT("invalid dst address length", dst->addr_len == 8); + fc |= IEEE_802154_FC_DST_ADDR_MODE_EXT; + } + if (src->addr_len == 2) { + fc |= IEEE_802154_FC_SRC_ADDR_MODE_SHORT; + } else { + LWIP_ASSERT("invalid src address length", src->addr_len == 8); + fc |= IEEE_802154_FC_SRC_ADDR_MODE_EXT; + } + hdr->frame_control = fc; + hdr->sequence_number = lowpan6_data.tx_frame_seq_num++; + hdr->destination_pan_id = lowpan6_data.ieee_802154_pan_id; /* pan id */ + + buffer = (u8_t *)hdr; + ieee_header_len = 5; + i = dst->addr_len; + /* reverse memcpy of dst addr */ + while (i-- > 0) { + buffer[ieee_header_len++] = dst->addr[i]; + } + /* Source PAN ID skipped due to PAN ID Compression */ + i = src->addr_len; + /* reverse memcpy of src addr */ + while (i-- > 0) { + buffer[ieee_header_len++] = src->addr[i]; + } + return ieee_header_len; +} + +/** Parse the IEEE 802.15.4 header from a pbuf. + * If successful, the header is hidden from the pbuf. + * + * PAN IDs and seuqence number are not checked + * + * @param p input pbuf, p->payload pointing at the IEEE 802.15.4 header + * @param src pointer to source address filled from the header + * @param dest pointer to destination address filled from the header + * @returns ERR_OK if successful + */ +static err_t +lowpan6_parse_iee802154_header(struct pbuf *p, struct lowpan6_link_addr *src, + struct lowpan6_link_addr *dest) +{ + u8_t *puc; + s8_t i; + u16_t frame_control, addr_mode; + u16_t datagram_offset; + + /* Parse IEEE 802.15.4 header */ + puc = (u8_t *)p->payload; + frame_control = puc[0] | (puc[1] << 8); + datagram_offset = 2; + if (frame_control & IEEE_802154_FC_SEQNO_SUPPR) { + if (IEEE_802154_FC_FRAME_VERSION_GET(frame_control) <= 1) { + /* sequence number suppressed, this is not valid for versions 0/1 */ + return ERR_VAL; + } + } else { + datagram_offset++; + } + datagram_offset += 2; /* Skip destination PAN ID */ + addr_mode = frame_control & IEEE_802154_FC_DST_ADDR_MODE_MASK; + if (addr_mode == IEEE_802154_FC_DST_ADDR_MODE_EXT) { + /* extended address (64 bit) */ + dest->addr_len = 8; + /* reverse memcpy: */ + for (i = 0; i < 8; i++) { + dest->addr[i] = puc[datagram_offset + 7 - i]; + } + datagram_offset += 8; + } else if (addr_mode == IEEE_802154_FC_DST_ADDR_MODE_SHORT) { + /* short address (16 bit) */ + dest->addr_len = 2; + /* reverse memcpy: */ + dest->addr[0] = puc[datagram_offset + 1]; + dest->addr[1] = puc[datagram_offset]; + datagram_offset += 2; + } else { + /* unsupported address mode (do we need "no address"?) */ + return ERR_VAL; + } + + if (!(frame_control & IEEE_802154_FC_PANID_COMPR)) { + /* No PAN ID compression, skip source PAN ID */ + datagram_offset += 2; + } + + addr_mode = frame_control & IEEE_802154_FC_SRC_ADDR_MODE_MASK; + if (addr_mode == IEEE_802154_FC_SRC_ADDR_MODE_EXT) { + /* extended address (64 bit) */ + src->addr_len = 8; + /* reverse memcpy: */ + for (i = 0; i < 8; i++) { + src->addr[i] = puc[datagram_offset + 7 - i]; + } + datagram_offset += 8; + } else if (addr_mode == IEEE_802154_FC_DST_ADDR_MODE_SHORT) { + /* short address (16 bit) */ + src->addr_len = 2; + src->addr[0] = puc[datagram_offset + 1]; + src->addr[1] = puc[datagram_offset]; + datagram_offset += 2; + } else { + /* unsupported address mode (do we need "no address"?) */ + return ERR_VAL; + } + + /* hide IEEE802.15.4 header. */ + if (pbuf_remove_header(p, datagram_offset)) { + return ERR_VAL; + } + return ERR_OK; +} + +/** Calculate the 16-bit CRC as required by IEEE 802.15.4 */ +u16_t +lowpan6_calc_crc(const void* buf, u16_t len) +{ +#define CCITT_POLY_16 0x8408U + u16_t i; + u8_t b; + u16_t crc = 0; + const u8_t* p = (const u8_t*)buf; + + for (i = 0; i < len; i++) { + u8_t data = *p; + for (b = 0U; b < 8U; b++) { + if (((data ^ crc) & 1) != 0) { + crc = (u16_t)((crc >> 1) ^ CCITT_POLY_16); + } else { + crc = (u16_t)(crc >> 1); + } + data = (u8_t)(data >> 1); + } + p++; + } + return crc; +} + +/* Fragmentation specific functions: */ + +static void +free_reass_datagram(struct lowpan6_reass_helper *lrh) +{ + if (lrh->reass) { + pbuf_free(lrh->reass); + } + if (lrh->frags) { + pbuf_free(lrh->frags); + } + mem_free(lrh); +} + +/** + * Removes a datagram from the reassembly queue. + **/ +static void +dequeue_datagram(struct lowpan6_reass_helper *lrh, struct lowpan6_reass_helper *prev) +{ + if (lowpan6_data.reass_list == lrh) { + lowpan6_data.reass_list = lowpan6_data.reass_list->next_packet; + } else { + /* it wasn't the first, so it must have a valid 'prev' */ + LWIP_ASSERT("sanity check linked list", prev != NULL); + prev->next_packet = lrh->next_packet; + } +} + +/** + * Periodic timer for 6LowPAN functions: + * + * - Remove incomplete/old packets + */ +void +lowpan6_tmr(void) +{ + struct lowpan6_reass_helper *lrh, *lrh_next, *lrh_prev = NULL; + + lrh = lowpan6_data.reass_list; + while (lrh != NULL) { + lrh_next = lrh->next_packet; + if ((--lrh->timer) == 0) { + dequeue_datagram(lrh, lrh_prev); + free_reass_datagram(lrh); + } else { + lrh_prev = lrh; + } + lrh = lrh_next; + } +} + +/* + * Encapsulates data into IEEE 802.15.4 frames. + * Fragments an IPv6 datagram into 6LowPAN units, which fit into IEEE 802.15.4 frames. + * If configured, will compress IPv6 and or UDP headers. + * */ +static err_t +lowpan6_frag(struct netif *netif, struct pbuf *p, const struct lowpan6_link_addr *src, const struct lowpan6_link_addr *dst) +{ + struct pbuf *p_frag; + u16_t frag_len, remaining_len, max_data_len; + u8_t *buffer; + u8_t ieee_header_len; + u8_t lowpan6_header_len; + u8_t hidden_header_len; + u16_t crc; + u16_t datagram_offset; + err_t err = ERR_IF; + + LWIP_ASSERT("lowpan6_frag: netif->linkoutput not set", netif->linkoutput != NULL); + + /* We'll use a dedicated pbuf for building 6LowPAN fragments. */ + p_frag = pbuf_alloc(PBUF_RAW, 127, PBUF_RAM); + if (p_frag == NULL) { + MIB2_STATS_NETIF_INC(netif, ifoutdiscards); + return ERR_MEM; + } + LWIP_ASSERT("this needs a pbuf in one piece", p_frag->len == p_frag->tot_len); + + /* Write IEEE 802.15.4 header. */ + buffer = (u8_t *)p_frag->payload; + ieee_header_len = lowpan6_write_iee802154_header((struct ieee_802154_hdr *)buffer, src, dst); + LWIP_ASSERT("ieee_header_len < p_frag->len", ieee_header_len < p_frag->len); + +#if LWIP_6LOWPAN_IPHC + /* Perform 6LowPAN IPv6 header compression according to RFC 6282 */ + /* do the header compression (this does NOT copy any non-compressed data) */ + err = lowpan6_compress_headers(netif, (u8_t *)p->payload, p->len, + &buffer[ieee_header_len], p_frag->len - ieee_header_len, &lowpan6_header_len, + &hidden_header_len, LWIP_6LOWPAN_CONTEXTS(netif), src, dst); + if (err != ERR_OK) { + MIB2_STATS_NETIF_INC(netif, ifoutdiscards); + pbuf_free(p_frag); + return err; + } + pbuf_remove_header(p, hidden_header_len); + +#else /* LWIP_6LOWPAN_IPHC */ + /* Send uncompressed IPv6 header with appropriate dispatch byte. */ + lowpan6_header_len = 1; + buffer[ieee_header_len] = 0x41; /* IPv6 dispatch */ +#endif /* LWIP_6LOWPAN_IPHC */ + + /* Calculate remaining packet length */ + remaining_len = p->tot_len; + + if (remaining_len > 0x7FF) { + MIB2_STATS_NETIF_INC(netif, ifoutdiscards); + /* datagram_size must fit into 11 bit */ + pbuf_free(p_frag); + return ERR_VAL; + } + + /* Fragment, or 1 packet? */ + max_data_len = LOWPAN6_MAX_PAYLOAD - ieee_header_len - lowpan6_header_len; + if (remaining_len > max_data_len) { + u16_t data_len; + /* We must move the 6LowPAN header to make room for the FRAG header. */ + memmove(&buffer[ieee_header_len + 4], &buffer[ieee_header_len], lowpan6_header_len); + + /* Now we need to fragment the packet. FRAG1 header first */ + buffer[ieee_header_len] = 0xc0 | (((p->tot_len + hidden_header_len) >> 8) & 0x7); + buffer[ieee_header_len + 1] = (p->tot_len + hidden_header_len) & 0xff; + + lowpan6_data.tx_datagram_tag++; + buffer[ieee_header_len + 2] = (lowpan6_data.tx_datagram_tag >> 8) & 0xff; + buffer[ieee_header_len + 3] = lowpan6_data.tx_datagram_tag & 0xff; + + /* Fragment follows. */ + data_len = (max_data_len - 4) & 0xf8; + frag_len = data_len + lowpan6_header_len; + + pbuf_copy_partial(p, buffer + ieee_header_len + lowpan6_header_len + 4, frag_len - lowpan6_header_len, 0); + remaining_len -= frag_len - lowpan6_header_len; + /* datagram offset holds the offset before compression */ + datagram_offset = frag_len - lowpan6_header_len + hidden_header_len; + LWIP_ASSERT("datagram offset must be a multiple of 8", (datagram_offset & 7) == 0); + + /* Calculate frame length */ + p_frag->len = p_frag->tot_len = ieee_header_len + 4 + frag_len + 2; /* add 2 bytes for crc*/ + + /* 2 bytes CRC */ + crc = LWIP_6LOWPAN_DO_CALC_CRC(p_frag->payload, p_frag->len - 2); + pbuf_take_at(p_frag, &crc, 2, p_frag->len - 2); + + /* send the packet */ + MIB2_STATS_NETIF_ADD(netif, ifoutoctets, p_frag->tot_len); + LWIP_DEBUGF(LWIP_LOWPAN6_DEBUG | LWIP_DBG_TRACE, ("lowpan6_send: sending packet %p\n", (void *)p)); + err = netif->linkoutput(netif, p_frag); + + while ((remaining_len > 0) && (err == ERR_OK)) { + struct ieee_802154_hdr *hdr = (struct ieee_802154_hdr *)buffer; + /* new frame, new seq num for ACK */ + hdr->sequence_number = lowpan6_data.tx_frame_seq_num++; + + buffer[ieee_header_len] |= 0x20; /* Change FRAG1 to FRAGN */ + + LWIP_ASSERT("datagram offset must be a multiple of 8", (datagram_offset & 7) == 0); + buffer[ieee_header_len + 4] = (u8_t)(datagram_offset >> 3); /* datagram offset in FRAGN header (datagram_offset is max. 11 bit) */ + + frag_len = (127 - ieee_header_len - 5 - 2) & 0xf8; + if (frag_len > remaining_len) { + frag_len = remaining_len; + } + + pbuf_copy_partial(p, buffer + ieee_header_len + 5, frag_len, p->tot_len - remaining_len); + remaining_len -= frag_len; + datagram_offset += frag_len; + + /* Calculate frame length */ + p_frag->len = p_frag->tot_len = frag_len + 5 + ieee_header_len + 2; + + /* 2 bytes CRC */ + crc = LWIP_6LOWPAN_DO_CALC_CRC(p_frag->payload, p_frag->len - 2); + pbuf_take_at(p_frag, &crc, 2, p_frag->len - 2); + + /* send the packet */ + MIB2_STATS_NETIF_ADD(netif, ifoutoctets, p_frag->tot_len); + LWIP_DEBUGF(LWIP_LOWPAN6_DEBUG | LWIP_DBG_TRACE, ("lowpan6_send: sending packet %p\n", (void *)p)); + err = netif->linkoutput(netif, p_frag); + } + } else { + /* It fits in one frame. */ + frag_len = remaining_len; + + /* Copy IPv6 packet */ + pbuf_copy_partial(p, buffer + ieee_header_len + lowpan6_header_len, frag_len, 0); + remaining_len = 0; + + /* Calculate frame length */ + p_frag->len = p_frag->tot_len = frag_len + lowpan6_header_len + ieee_header_len + 2; + LWIP_ASSERT("", p_frag->len <= 127); + + /* 2 bytes CRC */ + crc = LWIP_6LOWPAN_DO_CALC_CRC(p_frag->payload, p_frag->len - 2); + pbuf_take_at(p_frag, &crc, 2, p_frag->len - 2); + + /* send the packet */ + MIB2_STATS_NETIF_ADD(netif, ifoutoctets, p_frag->tot_len); + LWIP_DEBUGF(LWIP_LOWPAN6_DEBUG | LWIP_DBG_TRACE, ("lowpan6_send: sending packet %p\n", (void *)p)); + err = netif->linkoutput(netif, p_frag); + } + + pbuf_free(p_frag); + + return err; +} + +/** + * @ingroup sixlowpan + * Set context + */ +err_t +lowpan6_set_context(u8_t idx, const ip6_addr_t *context) +{ +#if LWIP_6LOWPAN_NUM_CONTEXTS > 0 + if (idx >= LWIP_6LOWPAN_NUM_CONTEXTS) { + return ERR_ARG; + } + + IP6_ADDR_ZONECHECK(context); + + ip6_addr_set(&lowpan6_data.lowpan6_context[idx], context); + + return ERR_OK; +#else + LWIP_UNUSED_ARG(idx); + LWIP_UNUSED_ARG(context); + return ERR_ARG; +#endif +} + +#if LWIP_6LOWPAN_INFER_SHORT_ADDRESS +/** + * @ingroup sixlowpan + * Set short address + */ +err_t +lowpan6_set_short_addr(u8_t addr_high, u8_t addr_low) +{ + short_mac_addr.addr[0] = addr_high; + short_mac_addr.addr[1] = addr_low; + + return ERR_OK; +} +#endif /* LWIP_6LOWPAN_INFER_SHORT_ADDRESS */ + +/* Create IEEE 802.15.4 address from netif address */ +static err_t +lowpan6_hwaddr_to_addr(struct netif *netif, struct lowpan6_link_addr *addr) +{ + addr->addr_len = 8; + if (netif->hwaddr_len == 8) { + LWIP_ERROR("NETIF_MAX_HWADDR_LEN >= 8 required", sizeof(netif->hwaddr) >= 8, return ERR_VAL;); + SMEMCPY(addr->addr, netif->hwaddr, 8); + } else if (netif->hwaddr_len == 6) { + /* Copy from MAC-48 */ + SMEMCPY(addr->addr, netif->hwaddr, 3); + addr->addr[3] = addr->addr[4] = 0xff; + SMEMCPY(&addr->addr[5], &netif->hwaddr[3], 3); + } else { + /* Invalid address length, don't know how to convert this */ + return ERR_VAL; + } + return ERR_OK; +} + +/** + * @ingroup sixlowpan + * Resolve and fill-in IEEE 802.15.4 address header for outgoing IPv6 packet. + * + * Perform Header Compression and fragment if necessary. + * + * @param netif The lwIP network interface which the IP packet will be sent on. + * @param q The pbuf(s) containing the IP packet to be sent. + * @param ip6addr The IP address of the packet destination. + * + * @return err_t + */ +err_t +lowpan6_output(struct netif *netif, struct pbuf *q, const ip6_addr_t *ip6addr) +{ + err_t result; + const u8_t *hwaddr; + struct lowpan6_link_addr src, dest; +#if LWIP_6LOWPAN_INFER_SHORT_ADDRESS + ip6_addr_t ip6_src; + struct ip6_hdr *ip6_hdr; +#endif /* LWIP_6LOWPAN_INFER_SHORT_ADDRESS */ + +#if LWIP_6LOWPAN_INFER_SHORT_ADDRESS + /* Check if we can compress source address (use aligned copy) */ + ip6_hdr = (struct ip6_hdr *)q->payload; + ip6_addr_copy_from_packed(ip6_src, ip6_hdr->src); + ip6_addr_assign_zone(&ip6_src, IP6_UNICAST, netif); + if (lowpan6_get_address_mode(&ip6_src, &short_mac_addr) == 3) { + src.addr_len = 2; + src.addr[0] = short_mac_addr.addr[0]; + src.addr[1] = short_mac_addr.addr[1]; + } else +#endif /* LWIP_6LOWPAN_INFER_SHORT_ADDRESS */ + { + result = lowpan6_hwaddr_to_addr(netif, &src); + if (result != ERR_OK) { + MIB2_STATS_NETIF_INC(netif, ifoutdiscards); + return result; + } + } + + /* multicast destination IP address? */ + if (ip6_addr_ismulticast(ip6addr)) { + MIB2_STATS_NETIF_INC(netif, ifoutnucastpkts); + /* We need to send to the broadcast address.*/ + return lowpan6_frag(netif, q, &src, &ieee_802154_broadcast); + } + + /* We have a unicast destination IP address */ + /* @todo anycast? */ + +#if LWIP_6LOWPAN_INFER_SHORT_ADDRESS + if (src.addr_len == 2) { + /* If source address was compressable to short_mac_addr, and dest has same subnet and + * is also compressable to 2-bytes, assume we can infer dest as a short address too. */ + dest.addr_len = 2; + dest.addr[0] = ((u8_t *)q->payload)[38]; + dest.addr[1] = ((u8_t *)q->payload)[39]; + if ((src.addr_len == 2) && (ip6_addr_netcmp_zoneless(&ip6_hdr->src, &ip6_hdr->dest)) && + (lowpan6_get_address_mode(ip6addr, &dest) == 3)) { + MIB2_STATS_NETIF_INC(netif, ifoutucastpkts); + return lowpan6_frag(netif, q, &src, &dest); + } + } +#endif /* LWIP_6LOWPAN_INFER_SHORT_ADDRESS */ + + /* Ask ND6 what to do with the packet. */ + result = nd6_get_next_hop_addr_or_queue(netif, q, ip6addr, &hwaddr); + if (result != ERR_OK) { + MIB2_STATS_NETIF_INC(netif, ifoutdiscards); + return result; + } + + /* If no hardware address is returned, nd6 has queued the packet for later. */ + if (hwaddr == NULL) { + return ERR_OK; + } + + /* Send out the packet using the returned hardware address. */ + dest.addr_len = netif->hwaddr_len; + /* XXX: Inferring the length of the source address from the destination address + * is not correct for IEEE 802.15.4, but currently we don't get this information + * from the neighbor cache */ + SMEMCPY(dest.addr, hwaddr, netif->hwaddr_len); + MIB2_STATS_NETIF_INC(netif, ifoutucastpkts); + return lowpan6_frag(netif, q, &src, &dest); +} +/** + * @ingroup sixlowpan + * NETIF input function: don't free the input pbuf when returning != ERR_OK! + */ +err_t +lowpan6_input(struct pbuf *p, struct netif *netif) +{ + u8_t *puc, b; + s8_t i; + struct lowpan6_link_addr src, dest; + u16_t datagram_size = 0; + u16_t datagram_offset, datagram_tag; + struct lowpan6_reass_helper *lrh, *lrh_next, *lrh_prev = NULL; + + if (p == NULL) { + return ERR_OK; + } + + MIB2_STATS_NETIF_ADD(netif, ifinoctets, p->tot_len); + + if (p->len != p->tot_len) { + /* for now, this needs a pbuf in one piece */ + goto lowpan6_input_discard; + } + + if (lowpan6_parse_iee802154_header(p, &src, &dest) != ERR_OK) { + goto lowpan6_input_discard; + } + + /* Check dispatch. */ + puc = (u8_t *)p->payload; + + b = *puc; + if ((b & 0xf8) == 0xc0) { + /* FRAG1 dispatch. add this packet to reassembly list. */ + datagram_size = ((u16_t)(puc[0] & 0x07) << 8) | (u16_t)puc[1]; + datagram_tag = ((u16_t)puc[2] << 8) | (u16_t)puc[3]; + + /* check for duplicate */ + lrh = lowpan6_data.reass_list; + while (lrh != NULL) { + uint8_t discard = 0; + lrh_next = lrh->next_packet; + if ((lrh->sender_addr.addr_len == src.addr_len) && + (memcmp(lrh->sender_addr.addr, src.addr, src.addr_len) == 0)) { + /* address match with packet in reassembly. */ + if ((datagram_tag == lrh->datagram_tag) && (datagram_size == lrh->datagram_size)) { + /* duplicate fragment. */ + goto lowpan6_input_discard; + } else { + /* We are receiving the start of a new datagram. Discard old one (incomplete). */ + discard = 1; + } + } + if (discard) { + dequeue_datagram(lrh, lrh_prev); + free_reass_datagram(lrh); + } else { + lrh_prev = lrh; + } + /* Check next datagram in queue. */ + lrh = lrh_next; + } + + pbuf_remove_header(p, 4); /* hide frag1 dispatch */ + + lrh = (struct lowpan6_reass_helper *) mem_malloc(sizeof(struct lowpan6_reass_helper)); + if (lrh == NULL) { + goto lowpan6_input_discard; + } + + lrh->sender_addr.addr_len = src.addr_len; + for (i = 0; i < src.addr_len; i++) { + lrh->sender_addr.addr[i] = src.addr[i]; + } + lrh->datagram_size = datagram_size; + lrh->datagram_tag = datagram_tag; + lrh->frags = NULL; + if (*(u8_t *)p->payload == 0x41) { + /* This is a complete IPv6 packet, just skip dispatch byte. */ + pbuf_remove_header(p, 1); /* hide dispatch byte. */ + lrh->reass = p; + } else if ((*(u8_t *)p->payload & 0xe0 ) == 0x60) { + lrh->reass = lowpan6_decompress(p, datagram_size, LWIP_6LOWPAN_CONTEXTS(netif), &src, &dest); + if (lrh->reass == NULL) { + /* decompression failed */ + mem_free(lrh); + goto lowpan6_input_discard; + } + } + /* TODO: handle the case where we already have FRAGN received */ + lrh->next_packet = lowpan6_data.reass_list; + lrh->timer = 2; + lowpan6_data.reass_list = lrh; + + return ERR_OK; + } else if ((b & 0xf8) == 0xe0) { + /* FRAGN dispatch, find packet being reassembled. */ + datagram_size = ((u16_t)(puc[0] & 0x07) << 8) | (u16_t)puc[1]; + datagram_tag = ((u16_t)puc[2] << 8) | (u16_t)puc[3]; + datagram_offset = (u16_t)puc[4] << 3; + pbuf_remove_header(p, 4); /* hide frag1 dispatch but keep datagram offset for reassembly */ + + for (lrh = lowpan6_data.reass_list; lrh != NULL; lrh_prev = lrh, lrh = lrh->next_packet) { + if ((lrh->sender_addr.addr_len == src.addr_len) && + (memcmp(lrh->sender_addr.addr, src.addr, src.addr_len) == 0) && + (datagram_tag == lrh->datagram_tag) && + (datagram_size == lrh->datagram_size)) { + break; + } + } + if (lrh == NULL) { + /* rogue fragment */ + goto lowpan6_input_discard; + } + /* Insert new pbuf into list of fragments. Each fragment is a pbuf, + this only works for unchained pbufs. */ + LWIP_ASSERT("p->next == NULL", p->next == NULL); + if (lrh->reass != NULL) { + /* FRAG1 already received, check this offset against first len */ + if (datagram_offset < lrh->reass->len) { + /* fragment overlap, discard old fragments */ + dequeue_datagram(lrh, lrh_prev); + free_reass_datagram(lrh); + goto lowpan6_input_discard; + } + } + if (lrh->frags == NULL) { + /* first FRAGN */ + lrh->frags = p; + } else { + /* find the correct place to insert */ + struct pbuf *q, *last; + u16_t new_frag_len = p->len - 1; /* p->len includes datagram_offset byte */ + for (q = lrh->frags, last = NULL; q != NULL; last = q, q = q->next) { + u16_t q_datagram_offset = ((u8_t *)q->payload)[0] << 3; + u16_t q_frag_len = q->len - 1; + if (datagram_offset < q_datagram_offset) { + if (datagram_offset + new_frag_len > q_datagram_offset) { + /* overlap, discard old fragments */ + dequeue_datagram(lrh, lrh_prev); + free_reass_datagram(lrh); + goto lowpan6_input_discard; + } + /* insert here */ + break; + } else if (datagram_offset == q_datagram_offset) { + if (q_frag_len != new_frag_len) { + /* fragment mismatch, discard old fragments */ + dequeue_datagram(lrh, lrh_prev); + free_reass_datagram(lrh); + goto lowpan6_input_discard; + } + /* duplicate, ignore */ + pbuf_free(p); + return ERR_OK; + } + } + /* insert fragment */ + if (last == NULL) { + lrh->frags = p; + } else { + last->next = p; + p->next = q; + } + } + /* check if all fragments were received */ + if (lrh->reass) { + u16_t offset = lrh->reass->len; + struct pbuf *q; + for (q = lrh->frags; q != NULL; q = q->next) { + u16_t q_datagram_offset = ((u8_t *)q->payload)[0] << 3; + if (q_datagram_offset != offset) { + /* not complete, wait for more fragments */ + return ERR_OK; + } + offset += q->len - 1; + } + if (offset == datagram_size) { + /* all fragments received, combine pbufs */ + u16_t datagram_left = datagram_size - lrh->reass->len; + for (q = lrh->frags; q != NULL; q = q->next) { + /* hide datagram_offset byte now */ + pbuf_remove_header(q, 1); + q->tot_len = datagram_left; + datagram_left -= q->len; + } + LWIP_ASSERT("datagram_left == 0", datagram_left == 0); + q = lrh->reass; + q->tot_len = datagram_size; + q->next = lrh->frags; + lrh->frags = NULL; + lrh->reass = NULL; + dequeue_datagram(lrh, lrh_prev); + mem_free(lrh); + + /* @todo: distinguish unicast/multicast */ + MIB2_STATS_NETIF_INC(netif, ifinucastpkts); + return ip6_input(q, netif); + } + } + /* pbuf enqueued, waiting for more fragments */ + return ERR_OK; + } else { + if (b == 0x41) { + /* This is a complete IPv6 packet, just skip dispatch byte. */ + pbuf_remove_header(p, 1); /* hide dispatch byte. */ + } else if ((b & 0xe0 ) == 0x60) { + /* IPv6 headers are compressed using IPHC. */ + p = lowpan6_decompress(p, datagram_size, LWIP_6LOWPAN_CONTEXTS(netif), &src, &dest); + if (p == NULL) { + MIB2_STATS_NETIF_INC(netif, ifindiscards); + return ERR_OK; + } + } else { + goto lowpan6_input_discard; + } + + /* @todo: distinguish unicast/multicast */ + MIB2_STATS_NETIF_INC(netif, ifinucastpkts); + + return ip6_input(p, netif); + } +lowpan6_input_discard: + MIB2_STATS_NETIF_INC(netif, ifindiscards); + pbuf_free(p); + /* always return ERR_OK here to prevent the caller freeing the pbuf */ + return ERR_OK; +} + +/** + * @ingroup sixlowpan + */ +err_t +lowpan6_if_init(struct netif *netif) +{ + netif->name[0] = 'L'; + netif->name[1] = '6'; + netif->output_ip6 = lowpan6_output; + + MIB2_INIT_NETIF(netif, snmp_ifType_other, 0); + + /* maximum transfer unit */ + netif->mtu = 1280; + + /* broadcast capability */ + netif->flags = NETIF_FLAG_BROADCAST /* | NETIF_FLAG_LOWPAN6 */; + + return ERR_OK; +} + +/** + * @ingroup sixlowpan + * Set PAN ID + */ +err_t +lowpan6_set_pan_id(u16_t pan_id) +{ + lowpan6_data.ieee_802154_pan_id = pan_id; + + return ERR_OK; +} + +#if !NO_SYS +/** + * @ingroup sixlowpan + * Pass a received packet to tcpip_thread for input processing + * + * @param p the received packet, p->payload pointing to the + * IEEE 802.15.4 header. + * @param inp the network interface on which the packet was received + */ +err_t +tcpip_6lowpan_input(struct pbuf *p, struct netif *inp) +{ + return tcpip_inpkt(p, inp, lowpan6_input); +} +#endif /* !NO_SYS */ + +#endif /* LWIP_IPV6 */ |