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- /**
- * @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 && LWIP_6LOWPAN
- #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 */
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