/**************************************************************************** * net/sixlowpan/sixlowpan_input.c * 6LoWPAN implementation (RFC 4944 and RFC 6282) * * Copyright (C) 2017, Gregory Nutt, all rights reserved * Author: Gregory Nutt * * Derives in large part from Contiki: * * Copyright (c) 2008, Swedish Institute of Computer Science. * All rights reserved. * Authors: Adam Dunkels * Nicolas Tsiftes * Niclas Finne * Mathilde Durvy * Julien Abeille * Joakim Eriksson * Joel Hoglund * * 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. Neither the name of the Institute nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE OR CONTRIBUTORS 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. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include "nuttx/mm/iob.h" #include "nuttx/net/netdev.h" #include "nuttx/net/radiodev.h" #include "nuttx/net/ip.h" #include "nuttx/net/icmpv6.h" #include "nuttx/net/sixlowpan.h" #include "nuttx/wireless/ieee802154/ieee802154_mac.h" #ifdef CONFIG_NET_PKT # include "pkt/pkt.h" #endif #include "sixlowpan/sixlowpan_internal.h" #ifdef CONFIG_NET_6LOWPAN /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* Success return values from sixlowpan_frame_process */ #define INPUT_PARTIAL 0 /* Frame processed successful, packet incomplete */ #define INPUT_COMPLETE 1 /* Frame processed successful, packet complete */ /* This is the size of a buffer large enough to hold the largest uncompressed * HC06 or HC1 headers. */ #ifdef CONFIG_NET_TCP /* The basic TCP header length is TCP_HDRLEN but could include up to 16 * additional 32-bit words of optional data. */ # define UNCOMP_MAXHDR (IPv6_HDRLEN + TCP_HDRLEN + 16*sizeof(uint32_t)) #elif defined(CONFIG_NET_UDP) /* The UDP header length is always 8 bytes */ # define UNCOMP_MAXHDR (IPv6_HDRLEN + UDP_HDRLEN) #elif defined(CONFIG_NET_ICMPv6) /* The ICMPv6 header length is a mere 4 bytes */ # define UNCOMP_MAXHDR (IPv6_HDRLEN + ICMPv6_HDRLEN) #else /* No other header type is handled. */ # define UNCOMP_MAXHDR IPv6_HDRLEN #endif /* Buffer access helpers */ #define IPv6BUF(dev) ((FAR struct ipv6_hdr_s *)((dev)->d_buf)) #define TCPBUF(dev) ((FAR struct tcp_hdr_s *)&(dev)->d_buf[IPv6_HDRLEN]) /**************************************************************************** * Private Data ****************************************************************************/ /* This big buffer could be avoided with a little more effort */ static uint8_t g_bitbucket[UNCOMP_MAXHDR]; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: sixlowpan_compress_ipv6hdr * * Description: * IPv6 dispatch "compression" function. Packets "Compression" when only * IPv6 dispatch is used * * There is no compression in this case, all fields are sent * inline. We just add the IPv6 dispatch byte before the packet. * * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | IPv6 Dsp | IPv6 header and payload ... * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * Input Parameters: * fptr - Pointer to the beginning of the frame under construction * bptr - Output goes here. Normally this is a known offset into d_buf, * may be redirected to g_bitbucket on the case of FRAGN frames. * proto - True: Copy the protocol header following the IPv6 header too. * * Returned Value: * None * ****************************************************************************/ static void sixlowpan_uncompress_ipv6hdr(FAR uint8_t *fptr, FAR uint8_t *bptr) { FAR struct ipv6_hdr_s *ipv6 = (FAR struct ipv6_hdr_s *)bptr; /* Put uncompressed IPv6 header in d_buf. */ g_frame_hdrlen += SIXLOWPAN_IPV6_HDR_LEN; memcpy(ipv6, fptr + g_frame_hdrlen, IPv6_HDRLEN); /* Update g_uncomp_hdrlen and g_frame_hdrlen. */ g_frame_hdrlen += IPv6_HDRLEN; g_uncomp_hdrlen += IPv6_HDRLEN; } /**************************************************************************** * Name: sixlowpan_uncompress_ipv6proto * * Description: * Copy the protocol header following the IPv4 header * * Input Parameters: * fptr - Pointer to the beginning of the frame under construction * bptr - Output goes here. Normally this is a known offset into d_buf, * may be redirected to g_bitbucket on the case of FRAGN frames. * proto - True: Copy the protocol header following the IPv6 header too. * * Returned Value: * The size of the protocol header that was copied. * ****************************************************************************/ static uint16_t sixlowpan_uncompress_ipv6proto(FAR uint8_t *fptr, FAR uint8_t *bptr) { FAR struct ipv6_hdr_s *ipv6 = (FAR struct ipv6_hdr_s *)bptr; uint16_t protosize = 0; /* Copy the following protocol header. */ switch (ipv6->proto) { #ifdef CONFIG_NET_TCP case IP_PROTO_TCP: { FAR struct tcp_hdr_s *tcp = (FAR struct tcp_hdr_s *)(fptr + g_frame_hdrlen); /* The TCP header length is encoded in the top 4 bits of the * tcpoffset field (in units of 32-bit words). */ protosize = ((uint16_t)tcp->tcpoffset >> 4) << 2; } break; #endif #ifdef CONFIG_NET_UDP case IP_PROTO_UDP: protosize = sizeof(struct udp_hdr_s); break; #endif #ifdef CONFIG_NET_ICMPv6 case IP_PROTO_ICMP6: protosize = sizeof(struct icmpv6_hdr_s); break; #endif default: nwarn("WARNING: Unrecognized proto: %u\n", ipv6->proto); return 0; } /* Copy the protocol header. */ memcpy((FAR uint8_t *)ipv6 + g_uncomp_hdrlen, fptr + g_frame_hdrlen, protosize); g_frame_hdrlen += protosize; g_uncomp_hdrlen += protosize; return protosize; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: sixlowpan_frame_process * * Description: * Process an incoming 6LoWPAN frame in 'iob'. * * If its a FRAG1 or a non-fragmented frame we first uncompress the IP * header. The 6LoWPAN payload and possibly the uncompressed IP header * are then copied into d_buf. An indication is returned if the packet * in d_buf is complete (i.e., non-fragmented frame or and the last * FRAGN frame). * * NOTE: We do not check for overlapping sixlowpan fragments (that is a * SHALL in the RFC 4944 and should never happen) * * Input Parameters: * radio - The radio network device driver interface. * metadata - Metadata characterizing the received frame. * iob - The IOB containing the frame. * * Returned Value: * On success, a value greater than equal to zero is returned, either: * * INPUT_PARTIAL Frame processed successful, packet incomplete * INPUT_COMPLETE Frame processed successful, packet complete * * Othewise a negated errno value is returned to indicate the nature of the * failure. * * Assumptions: * Network is locked * ****************************************************************************/ static int sixlowpan_frame_process(FAR struct radio_driver_s *radio, FAR const void *metadata, FAR struct iob_s *iob) { FAR struct sixlowpan_reassbuf_s *reass; struct netdev_varaddr_s fragsrc; FAR uint8_t *fptr; /* Convenience pointer to beginning of the frame */ FAR uint8_t *bptr; /* Used to redirect uncompressed header to the bitbucket */ FAR uint8_t *hc1; /* Convenience pointer to HC1 data */ FAR uint8_t *fragptr; /* Pointer to the fragmentation header */ uint16_t fragsize = 0; /* Size of the IP packet (read from fragment) */ uint16_t paysize; /* Size of the data payload */ uint16_t fragtag = 0; /* Tag of the fragment */ uint8_t fragoffset = 0; /* Offset of the fragment in the IP packet */ uint8_t protosize = 0; /* Length of the protocol header (treated like payload) */ bool isfrag = false; /* true: Frame is a fragment */ bool isfrag1 = false; /* true: Frame is the first fragement of the series */ int reqsize; /* Required buffer size */ int hdrsize; /* Size of the IEEE802.15.4 header */ int ret; /* Get a pointer to the payload following the IEEE802.15.4 frame header(s). * This size includes both fragmentation and FCF headers. */ fptr = iob->io_data; /* Frame data is in I/O buffer */ hdrsize = iob->io_offset; /* Offset past the MAC header */ DEBUGASSERT((unsigned)hdrsize < iob->io_len); /* Initialize global data. Locking the network guarantees that we have * exclusive use of the global values for intermediate calculations. */ g_uncomp_hdrlen = 0; g_frame_hdrlen = hdrsize; /* Since we don't support the mesh and broadcast header, the first header * we look for is the fragmentation header. NOTE that g_frame_hdrlen * already includes the fragementation header, if presetn. */ fragptr = fptr + hdrsize; switch ((GETUINT16(fragptr, SIXLOWPAN_FRAG_DISPATCH_SIZE) & 0xf800) >> 8) { /* First fragment of new reassembly */ case SIXLOWPAN_DISPATCH_FRAG1: { /* Set up for the reassembly */ fragsize = GETUINT16(fragptr, SIXLOWPAN_FRAG_DISPATCH_SIZE) & 0x07ff; fragtag = GETUINT16(fragptr, SIXLOWPAN_FRAG_TAG); g_frame_hdrlen += SIXLOWPAN_FRAG1_HDR_LEN; ninfo("FRAG1: fragsize=%d fragtag=%d fragoffset=%d\n", fragsize, fragtag, fragoffset); /* Drop any zero length fragments */ if (fragsize == 0) { nwarn("WARNING: Dropping zero-length 6LoWPAN fragment\n"); return INPUT_PARTIAL; } /* Drop the packet if it cannot fit into the d_buf */ if (fragsize > CONFIG_NET_6LOWPAN_PKTSIZE) { nwarn("WARNING: Reassembled packet size exeeds CONFIG_NET_6LOWPAN_PKTSIZE\n"); return -ENOSPC; } /* Extract the source address from the 'metadata'. */ ret = sixlowpan_extract_srcaddr(radio, metadata, &fragsrc); if (ret < 0) { nerr("ERROR: sixlowpan_extract_srcaddr failed: %d\n", ret); return ret; } /* Allocate a new reassembly buffer */ reass = sixlowpan_reass_allocate(fragtag, &fragsrc); if (reass == NULL) { nerr("ERROR: Failed to allocate a reassembly buffer\n"); return -ENOMEM; } radio->r_dev.d_buf = reass->rb_buf; radio->r_dev.d_len = 0; reass->rb_pktlen = fragsize; /* Indicate the first fragment of the reassembly */ bptr = reass->rb_buf; isfrag1 = true; isfrag = true; } break; case SIXLOWPAN_DISPATCH_FRAGN: { /* Get offset, tag, size. Offset is in units of 8 bytes. */ fragoffset = fragptr[SIXLOWPAN_FRAG_OFFSET]; fragtag = GETUINT16(fragptr, SIXLOWPAN_FRAG_TAG); fragsize = GETUINT16(fragptr, SIXLOWPAN_FRAG_DISPATCH_SIZE) & 0x07ff; g_frame_hdrlen += SIXLOWPAN_FRAGN_HDR_LEN; /* Extract the source address from the 'metadata'. */ ret = sixlowpan_extract_srcaddr(radio, metadata, &fragsrc); if (ret < 0) { nerr("ERROR: sixlowpan_extract_srcaddr failed: %d\n", ret); return ret; } /* Find the existing reassembly buffer with the same tag and source address */ reass = sixlowpan_reass_find(fragtag, &fragsrc); if (reass == NULL) { nerr("ERROR: Failed to find a reassembly buffer for tag=%04x\n", fragtag); return -ENOENT; } if (fragsize != reass->rb_pktlen) { /* The packet is a fragment but its size does not match. */ nwarn("WARNING: Dropping 6LoWPAN packet. Bad fragsize: %u vs &u\n", fragsize, reass->rb_pktlen); ret = -EPERM; goto errout_with_reass; } radio->r_dev.d_buf = reass->rb_buf; radio->r_dev.d_len = 0; ninfo("FRAGN: fragsize=%d fragtag=%d fragoffset=%d\n", fragsize, fragtag, fragoffset); ninfo("FRAGN: rb_accumlen=%d paysize=%u fragsize=%u\n", reass->rb_accumlen, iob->io_len - g_frame_hdrlen, fragsize); /* Indicate that this frame is a another fragment for reassembly */ bptr = g_bitbucket; isfrag = true; } break; /* Not a fragment */ default: /* We still need a packet buffer. But in this case, the driver should * have provided one. */ DEBUGASSERT(radio->r_dev.d_buf != NULL); reass = (FAR struct sixlowpan_reassbuf_s *)radio->r_dev.d_buf; reass->rb_pool = REASS_POOL_RADIO; bptr = reass->rb_buf; break; } /* Process next dispatch and headers */ hc1 = fptr + g_frame_hdrlen; #ifdef CONFIG_NET_6LOWPAN_COMPRESSION_HC06 if ((hc1[SIXLOWPAN_HC1_DISPATCH] & SIXLOWPAN_DISPATCH_IPHC_MASK) == SIXLOWPAN_DISPATCH_IPHC) { ninfo("IPHC Dispatch\n"); sixlowpan_uncompresshdr_hc06(radio, metadata, fragsize, iob, fptr, bptr); } else #endif /* CONFIG_NET_6LOWPAN_COMPRESSION_HC06 */ #ifdef CONFIG_NET_6LOWPAN_COMPRESSION_HC1 if (hc1[SIXLOWPAN_HC1_DISPATCH] == SIXLOWPAN_DISPATCH_HC1) { ninfo("HC1 Dispatch\n"); sixlowpan_uncompresshdr_hc1(radio, metadata, fragsize, iob, fptr, bptr); } else #endif /* CONFIG_NET_6LOWPAN_COMPRESSION_HC1 */ if (hc1[SIXLOWPAN_HC1_DISPATCH] == SIXLOWPAN_DISPATCH_IPV6) { ninfo("IPv6 Dispatch\n"); /* Uncompress the IPv6 header */ sixlowpan_uncompress_ipv6hdr(fptr, bptr); /* A protocol header will follow the IPv6 header only on a non- * fragmented packet or on the first fragment of a fragmented * packet. */ if (!isfrag || isfrag1) { protosize = sixlowpan_uncompress_ipv6proto(fptr, bptr); } } else { /* Unknown or unsupported header */ nwarn("WARNING: Unknown dispatch: %u\n", hc1[SIXLOWPAN_HC1_DISPATCH]); ret = -ENOSYS; goto errout_with_reass; } /* Is this the first fragment is a sequence? */ if (isfrag1) { /* Yes.. Remember the offset from the beginning of d_buf where we * begin placing the data payload. */ reass->rb_boffset = g_uncomp_hdrlen - protosize; } /* No.. is this a subsequent fragment in the same sequence? */ else if (isfrag) { /* Yes, recover the offset from the beginning of the d_buf where * we began placing payload data. */ g_uncomp_hdrlen = reass->rb_boffset; } /* Copy "payload" from the frame buffer to the IEEE802.15.4 MAC driver's * packet buffer, d_buf. If this frame is a first fragment or not part of * a fragmented packet, we have already copied the compressed headers, * g_uncomp_hdrlen and g_frame_hdrlen are non-zerio, fragoffset is. */ paysize = iob->io_len - g_frame_hdrlen; if (paysize > CONFIG_NET_6LOWPAN_PKTSIZE) { nwarn("WARNING: Packet dropped due to payload (%u) > packet buffer (%u)\n", paysize, CONFIG_NET_6LOWPAN_PKTSIZE); ret = -ENOSPC; goto errout_with_reass; } /* Sanity-check size of incoming packet to avoid buffer overflow */ reqsize = g_uncomp_hdrlen + (fragoffset << 3) + paysize; if (reqsize > CONFIG_NET_6LOWPAN_PKTSIZE) { nwarn("WARNING: Required buffer size: %u+%u+%u=%u Available=%u\n", g_uncomp_hdrlen, (fragoffset << 3), paysize, reqsize, CONFIG_NET_6LOWPAN_PKTSIZE); ret = -ENOMEM; goto errout_with_reass; } memcpy(radio->r_dev.d_buf + g_uncomp_hdrlen + (fragoffset << 3), fptr + g_frame_hdrlen, paysize); /* Update reass->rb_accumlen if the frame is a fragment, reass->rb_pktlen * otherwise. */ if (isfrag) { /* Check if it is the last fragment to be processed. * * If this is the last fragment, we may shave off any extrenous * bytes at the end. We must be liberal in what we accept. */ reass->rb_accumlen = g_uncomp_hdrlen + (fragoffset << 3) + paysize; } else { reass->rb_pktlen = paysize + g_uncomp_hdrlen; } /* If we have a full IP packet in sixlowpan_buf, deliver it to * the IP stack */ ninfo("rb_accumlen=%d rb_pktlen=%d paysize=%d\n", reass->rb_accumlen, reass->rb_pktlen, paysize); if (reass->rb_accumlen == 0 || reass->rb_accumlen >= reass->rb_pktlen) { ninfo("IP packet ready (length %d)\n", reass->rb_pktlen); radio->r_dev.d_buf = reass->rb_buf; radio->r_dev.d_len = reass->rb_pktlen; reass->rb_active = false; reass->rb_pktlen = 0; reass->rb_accumlen = 0; return INPUT_COMPLETE; } radio->r_dev.d_buf = NULL; radio->r_dev.d_len = 0; return INPUT_PARTIAL; errout_with_reass: sixlowpan_reass_free(reass); return ret; } /**************************************************************************** * Name: sixlowpan_dispatch * * Description: * Inject the packet in d_buf into the network for normal packet processing. * * Input Parameters: * radio - The IEEE802.15.4 MAC network driver interface. * * Returned Value: * None * ****************************************************************************/ static int sixlowpan_dispatch(FAR struct radio_driver_s *radio) { FAR struct sixlowpan_reassbuf_s *reass; int ret; sixlowpan_dumpbuffer("Incoming packet", (FAR const uint8_t *)IPv6BUF(&radio->r_dev), radio->r_dev.d_len); #ifdef CONFIG_NET_PKT /* When packet sockets are enabled, feed the frame into the packet tap */ ninfo("Packet tap\n"); pkt_input(&radio->r_dev); #endif /* We only accept IPv6 packets. */ ninfo("IPv6 packet dispatch\n"); NETDEV_RXIPV6(&radio->r_dev); /* Give the IPv6 packet to the network layer. NOTE: If there is a * problem with IPv6 header, it will be silently dropped and d_len will * be set to zero. Oddly, ipv6_input() will return OK in this case. */ ret = ipv6_input(&radio->r_dev); /* Free the reassemby buffer */ reass = (FAR struct sixlowpan_reassbuf_s *)radio->r_dev.d_buf; DEBUGASSERT(reass != NULL); sixlowpan_reass_free(reass); return ret; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: sixlowpan_input * * Description: * Process an incoming 6LoWPAN frame. * * This function is called when the radio device driver has received an * frame from the network. The frame from the device driver must be * provided in by the IOB frame argument of the function call: * * - The frame data is in the IOB io_data[] buffer, * - The length of the frame is in the IOB io_len field, and * - The offset past and radio MAC header is provided in the io_offset * field. * * The frame argument may refer to a single frame (a list of length one) * or may it be the head of a list of multiple frames. * * - The io_flink field points to the next frame in the list (if enable) * - The last frame in the list will have io_flink == NULL. * * An non-NULL d_buf of size CONFIG_NET_6LOWPAN_PKTSIZE + CONFIG_NET_GUARDSIZE * must also be provided. The frame will be decompressed and placed in * the d_buf. Fragmented packets will also be reassembled in the d_buf as * they are received (meaning for the driver, that two packet buffers are * required: One for reassembly of RX packets and one used for TX polling). * * After each frame is processed into d_buf, the IOB is deallocated. If * reassembly is incomplete, the partially reassembled packet must be * preserved by the radio network drvier and provided again when the next * frame is received. * * When the packet in the d_buf is fully reassembled, it will be provided * to the network as with any other received packet. d_len will be set * the length of the uncompressed, reassembled packet. * * After the network processes the packet, d_len will be set to zero. * Network logic may also decide to send a response to the packet. In * that case, the outgoing network packet will be placed in d_buf and * d_len will be set to a non-zero value. That case is handled by this * function. * * If that case occurs, the packet will be converted to a list of * compressed and possibly fragmented frames and provided to the MAC * network driver via the req_data() method as with other TX operations. * * Input Parameters: * radio The radio network driver interface. * framelist - The head of an incoming list of frames. Normally this * would be a single frame. A list may be provided if * appropriate, however. * metadata - Meta data characterizing the received packet. The specific * type of this metadata is obfuscated and depends on the * type of the radio driver. This could be be either * (1) struct ieee802154_data_ind_s for an IEEE 802.15.4 * radio, or (2) struct pktradio_metadata_s for a non-standard * packet radio. * * If there are multilple frames in the list, this metadata * must apply to all of the frames in the list. * * Returned Value: * Ok is returned on success; Othewise a negated errno value is returned. * ****************************************************************************/ int sixlowpan_input(FAR struct radio_driver_s *radio, FAR struct iob_s *framelist, FAR const void *metadata) { int ret = -EINVAL; DEBUGASSERT(radio != NULL && framelist != NULL); /* Verify that an frame has been provided. */ while (framelist != NULL) { FAR struct iob_s *iob; /* Remove the IOB containing the frame from the device structure */ iob = framelist; framelist = iob->io_flink; sixlowpan_dumpbuffer("Incoming frame", iob->io_data, iob->io_len); /* Process the frame, decompressing it into the packet buffer */ ret = sixlowpan_frame_process(radio, metadata, iob); /* If the frame was a valid 6LoWPAN frame, free the IOB the held the * consumed frame. Otherwise, the frame must stay allocated since the * MAC layer will try and pass it to another receiver to see if that * receiver wants it. */ if (ret >= 0) { iob_free(iob); } /* Was the frame successfully processed? Is the packet in d_buf fully * reassembled? */ if (ret == INPUT_COMPLETE) { /* Inject the uncompressed, reassembled packet into the network */ ret = sixlowpan_dispatch(radio); if (ret >= 0) { /* Check if this resulted in a request to send an outgoing * packet. */ if (radio->r_dev.d_len > 0) { FAR struct ipv6_hdr_s *ipv6hdr; FAR uint8_t *buffer; struct netdev_varaddr_s destmac; size_t hdrlen; size_t buflen; /* The IPv6 header followed by TCP or UDP headers should * lie at the beginning of d_buf since there is no link * layer protocol header. */ ipv6hdr = IPv6BUF(&radio->r_dev); /* Get the IEEE 802.15.4 MAC address of the destination. * This assumes an encoding of the MAC address in the IPv6 * address. */ ret = sixlowpan_nexthopaddr(radio, ipv6hdr->destipaddr, &destmac); if (ret < 0) { nerr("ERROR: Failed to get dest MAC address: %d\n", ret); goto drop; } /* The data payload should follow the IPv6 header plus * the protocol header. */ switch (ipv6hdr->proto) { #ifdef CONFIG_NET_TCP case IP_PROTO_TCP: { FAR struct tcp_hdr_s *tcp = TCPBUF(&radio->r_dev); uint16_t tcplen; /* The TCP header length is encoded in the top 4 bits * of the tcpoffset field (in units of 32-bit words). */ tcplen = ((uint16_t)tcp->tcpoffset >> 4) << 2; hdrlen = IPv6_HDRLEN + tcplen; } break; #endif #ifdef CONFIG_NET_UDP case IP_PROTO_UDP: { hdrlen = IPv6_HDRLEN + UDP_HDRLEN; } break; #endif #ifdef CONFIG_NET_ICMPv6 case IP_PROTO_ICMP6: { hdrlen = IPv6_HDRLEN + ICMPv6_HDRLEN; } break; #endif default: { nwarn("WARNING: Unsupported protoype: %u\n", ipv6hdr->proto); ret = -EPROTO; goto drop; } } if (hdrlen > radio->r_dev.d_len) { nwarn("WARNING: Packet too small: Have %u need >%u\n", radio->r_dev.d_len, hdrlen); ret = -ENOBUFS; goto drop; } /* Convert the outgoing packet into a frame list. */ buffer = radio->r_dev.d_buf + hdrlen; buflen = radio->r_dev.d_len - hdrlen; ret = sixlowpan_queue_frames(radio, ipv6hdr, buffer, buflen, &destmac); drop: radio->r_dev.d_len = 0; } } } } return ret; } #endif /* CONFIG_NET_6LOWPAN */