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nuttx/net/sixlowpan/sixlowpan_input.c

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/****************************************************************************
* net/sixlowpan/sixlowpan_input.c
* 6loWPAN implementation (RFC4944 and draft-ietf-6loWPAN-hc-06)
*
* Copyright (C) 2017, Gregory Nutt, all rights reserved
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Derives in large part from Contiki:
*
* Copyright (c) 2008, Swedish Institute of Computer Science.
* All rights reserved.
* Authors: Adam Dunkels <adam@sics.se>
* Nicolas Tsiftes <nvt@sics.se>
* Niclas Finne <nfi@sics.se>
* Mathilde Durvy <mdurvy@cisco.com>
* Julien Abeille <jabeille@cisco.com>
* Joakim Eriksson <joakime@sics.se>
* Joel Hoglund <joel@sics.se>
*
* 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 <nuttx/config.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#ifdef CONFIG_NET_6LOWPAN_FRAG
# include "nuttx/clock.h"
#endif
#include "nuttx/net/netdev.h"
#include "nuttx/net/ip.h"
#include "nuttx/net/sixlowpan.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 */
/* Re-assembly timeout in clock ticks */
#define NET_6LOWPAN_TIMEOUT SEC2TICK(CONFIG_NET_6LOWPAN_MAXAGE)
/* 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 + TCP_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
****************************************************************************/
#ifdef CONFIG_NET_6LOWPAN_FRAG
/* This big buffer could be avoided with a little more effort */
static uint8_t g_bitbucket[UNCOMP_MAXHDR];
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: sixlowpan_recv_hdrlen
*
* Description:
* Get the length of the IEEE802.15.4 FCF header on the received frame.
*
* Input Parameters:
* ieee - The IEEE802.15.4 MAC network driver interface.
* iob - The IOB containing the frame.
*
* Returned Value:
* Ok is returned on success; Othewise a negated errno value is returned.
*
* Assumptions:
* Network is locked
*
****************************************************************************/
int sixlowpan_recv_hdrlen(FAR const uint8_t *fptr)
{
uint16_t hdrlen;
uint8_t addrmode;
/* Minimum header: 2 byte FCF + 1 byte sequence number */
hdrlen = 3;
/* Account for destination address size */
addrmode = (fptr[1] & FRAME802154_DSTADDR_MASK) >> FRAME802154_DSTADDR_SHIFT;
if (addrmode == FRAME802154_SHORTADDRMODE)
{
/* 2 byte dest PAN + 2 byte dest short address */
hdrlen += 4;
}
else if (addrmode == FRAME802154_LONGADDRMODE)
{
/* 2 byte dest PAN + 6 byte dest long address */
hdrlen += 10;
}
else if (addrmode != FRAME802154_NOADDR)
{
nwarn("WARNING: Unrecognized address mode\n");
return -ENOSYS;
}
else if ((fptr[0] & (1 << FRAME802154_PANIDCOMP_SHIFT)) != 0)
{
nwarn("WARNING: PAN compression, but no destination address\n");
return -EINVAL;
}
/* Account for source address size */
addrmode = (fptr[1] & FRAME802154_SRCADDR_MASK) >> FRAME802154_SRCADDR_SHIFT;
if (addrmode == FRAME802154_NOADDR)
{
return hdrlen;
}
else
{
if ((fptr[0] & (1 << FRAME802154_PANIDCOMP_SHIFT)) == 0)
{
hdrlen += 2;
}
/* Add the length of the source address */
if (addrmode == FRAME802154_SHORTADDRMODE)
{
return hdrlen + 2;
}
else if (addrmode == FRAME802154_LONGADDRMODE)
{
return hdrlen + 8;
}
}
return 0;
}
/****************************************************************************
* 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.
*
* 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;
uint16_t protosize;
/* 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;
/* Copy the following protocol header, */
switch (ipv6->proto)
{
#ifdef CONFIG_NET_TCP
case IP_PROTO_TCP:
{
FAR struct tcp_hdr_s *tcp = &((FAR struct ipv6tcp_hdr_s *)ipv6)->tcp;
/* 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;
}
/* 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;
}
/****************************************************************************
* 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:
* ieee - The IEEE802.15.4 MAC network driver interface.
* iob - The IOB containing the frame.
*
* Returned Value:
* Ok is returned on success; Othewise a negated errno value is returned.
*
* Assumptions:
* Network is locked
*
****************************************************************************/
static int sixlowpan_frame_process(FAR struct ieee802154_driver_s *ieee,
FAR struct iob_s *iob)
{
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 */
uint16_t fragsize = 0; /* Size of the IP packet (read from fragment) */
uint16_t paysize; /* Size of the data payload */
uint8_t fragoffset = 0; /* Offset of the fragment in the IP packet */
int reqsize; /* Required buffer size */
int hdrsize; /* Size of the IEEE802.15.4 header */
#ifdef CONFIG_NET_6LOWPAN_FRAG
FAR uint8_t *fragptr; /* Pointer to the fragmentation header */
bool isfrag = false;
bool isfirstfrag = false;
uint16_t fragtag = 0; /* Tag of the fragment */
systime_t elapsed; /* Elapsed time */
#endif /* CONFIG_NET_6LOWPAN_FRAG */
/* 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;
hdrsize = sixlowpan_recv_hdrlen(fptr);
if (hdrsize < 0)
{
nwarn("Invalid IEEE802.15.2 header: %d\n", hdrsize);
return hdrsize;
}
/* 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;
#ifdef CONFIG_NET_6LOWPAN_FRAG
/* 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 ((GETINT16(fragptr, RIME_FRAG_DISPATCH_SIZE) & 0xf800) >> 8)
{
/* First fragment of new reassembly */
case SIXLOWPAN_DISPATCH_FRAG1:
{
/* Set up for the reassembly */
fragsize = GETINT16(fragptr, RIME_FRAG_DISPATCH_SIZE) & 0x07ff;
fragtag = GETINT16(fragptr, RIME_FRAG_TAG);
g_frame_hdrlen += SIXLOWPAN_FRAG1_HDR_LEN;
ninfo("FRAG1: fragsize=%d fragtag=%d fragoffset=%d\n",
fragsize, fragtag, fragoffset);
/* Indicate the first fragment of the reassembly */
isfirstfrag = true;
isfrag = true;
}
break;
case SIXLOWPAN_DISPATCH_FRAGN:
{
/* Set offset, tag, size. Offset is in units of 8 bytes. */
fragoffset = fragptr[RIME_FRAG_OFFSET];
fragtag = GETINT16(fragptr, RIME_FRAG_TAG);
fragsize = GETINT16(fragptr, RIME_FRAG_DISPATCH_SIZE) & 0x07ff;
g_frame_hdrlen += SIXLOWPAN_FRAGN_HDR_LEN;
ninfo("FRAGN: fragsize=%d fragtag=%d fragoffset=%d\n",
fragsize, fragtag, fragoffset);
ninfo("FRAGN: i_accumlen=%d paysize=%u fragsize=%u\n",
ieee->i_accumlen, iob->io_len - g_frame_hdrlen, fragsize);
/* Indicate that this frame is a another fragment for reassembly */
isfrag = true;
}
break;
/* Not a fragment */
default:
break;
}
/* Check if we are currently reassembling a packet */
bptr = ieee->i_dev.d_buf;
if (ieee->i_accumlen > 0)
{
/* If reassembly timed out, cancel it */
elapsed = clock_systimer() - ieee->i_time;
if (elapsed > NET_6LOWPAN_TIMEOUT)
{
nwarn("WARNING: Reassembly timed out\n");
ieee->i_pktlen = 0;
ieee->i_accumlen = 0;
}
/* In this case what we expect is that the next frame will hold the
* next FRAGN of the sequence. We have to handle a few exeptional
* cases that we need to handle:
*
* 1. If we are currently reassembling a packet, but have just received
* the first fragment of another packet. We can either ignore it and
* hope to receive the rest of the under-reassembly packet fragments,
* or we can discard the previous packet altogether, and start
* reassembling the new packet. Here we discard the previous packet,
* and start reassembling the new packet.
* 2. The new frame is not a fragment. We should be able to handle this
* case, but we cannot because that would require two packet buffers.
* It could be handled with a more extensive design.
* 3. The fragment came from a different sender. What would this mean?
*
*/
else if (!isfrag)
{
/* Discard the partially assembled packet */
nwarn("WARNING: Non-fragment frame received during reassembly\n");
ieee->i_pktlen = 0;
ieee->i_accumlen = 0;
}
/* It is a fragment of some kind. Drop any zero length fragments */
else if (fragsize == 0)
{
nwarn("WARNING: Dropping zero-length 6loWPAN fragment\n");
return INPUT_PARTIAL;
}
/* A non-zero, first fragement received while we are in the middle of
* rassembly. Discard the partially assembled packet and start over.
*/
else if (isfirstfrag)
{
nwarn("WARNING: First fragment frame received during reassembly\n");
ieee->i_pktlen = 0;
ieee->i_accumlen = 0;
}
/* Verify that this fragment is part of that reassembly sequence */
else if (fragsize != ieee->i_pktlen || ieee->i_reasstag != fragtag ||
!rimeaddr_cmp(&ieee->i_fragsrc, &g_pktaddrs[PACKETBUF_ADDR_SENDER]))
{
/* The packet is a fragment that does not belong to the packet
* being reassembled or the packet is not a fragment.
*/
nwarn("WARNING: Dropping 6loWPAN packet that is not a fragment of "
"the packet currently being reassembled\n");
return INPUT_PARTIAL;
}
else
{
/* Looks good. We are currently processing a reassembling sequence
* and we recieved a valid FRAGN fragment. Redirect the header
* uncompression to our bitbucket.
*/
bptr = g_bitbucket;
}
}
/* There is no reassembly in progress. Check if we received a fragment */
else if (isfrag)
{
/* Another case that we have to handle is if a FRAGN fragment of a
* reassembly is received, but we are not currently reassembling a
* packet. I think we have no choice but to drop the packet in this
* case.
*/
if (!isfirstfrag)
{
nwarn("WARNING: FRAGN 6loWPAN fragment while not reassembling\n");
return OK;
}
/* Drop the packet if it cannot fit into the d_buf */
if (fragsize > CONFIG_NET_6LOWPAN_MTU)
{
nwarn("WARNING: Reassembled packet size exeeds CONFIG_NET_6LOWPAN_MTU\n");
return OK;
}
ieee->i_pktlen = fragsize;
ieee->i_reasstag = fragtag;
ieee->i_time = clock_systimer();
ninfo("Starting reassembly: i_pktlen %u, i_reasstag %d\n",
ieee->i_pktlen, ieee->i_reasstag);
rimeaddr_copy(&ieee->i_fragsrc, &g_pktaddrs[PACKETBUF_ADDR_SENDER]);
}
#endif /* CONFIG_NET_6LOWPAN_FRAG */
/* Process next dispatch and headers */
hc1 = fptr + g_frame_hdrlen;
#ifdef CONFIG_NET_6LOWPAN_COMPRESSION_HC06
if ((hc1[RIME_HC1_DISPATCH] & SIXLOWPAN_DISPATCH_IPHC_MASK) == SIXLOWPAN_DISPATCH_IPHC)
{
ninfo("IPHC Dispatch\n");
sixlowpan_uncompresshdr_hc06(fragsize, iob, fptr, bptr);
}
else
#endif /* CONFIG_NET_6LOWPAN_COMPRESSION_HC06 */
#ifdef CONFIG_NET_6LOWPAN_COMPRESSION_HC1
if (hc1[RIME_HC1_DISPATCH] == SIXLOWPAN_DISPATCH_HC1)
{
ninfo("HC1 Dispatch\n");
sixlowpan_uncompresshdr_hc1(fragsize, iob, fptr, bptr);
}
else
#endif /* CONFIG_NET_6LOWPAN_COMPRESSION_HC1 */
if (hc1[RIME_HC1_DISPATCH] == SIXLOWPAN_DISPATCH_IPV6)
{
ninfo("IPv6 Dispatch\n");
sixlowpan_uncompress_ipv6hdr(fptr, bptr);
}
else
{
/* Unknown or unsupported header */
nwarn("WARNING: Unknown dispatch: %u\n", hc1[RIME_HC1_DISPATCH]);
return OK;
}
#ifdef CONFIG_NET_6LOWPAN_FRAG
/* Is this the first fragment is a sequence? */
if (isfirstfrag)
{
/* Yes.. Remember the offset from the beginning of d_buf where we
* begin placing the data payload.
*/
ieee->i_boffset = g_uncomp_hdrlen;
}
/* 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 = ieee->i_boffset;
}
#endif /* CONFIG_NET_6LOWPAN_FRAG */
/* Copy "payload" from the rime buffer to the IEEE802.15.4 MAC driver's
* 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_MTU)
{
nwarn("WARNING: Packet dropped due to payload (%u) > packet buffer (%u)\n",
paysize, CONFIG_NET_6LOWPAN_MTU);
return OK;
}
/* Sanity-check size of incoming packet to avoid buffer overflow */
reqsize = g_uncomp_hdrlen + (fragoffset << 3) + paysize;
if (reqsize > CONFIG_NET_6LOWPAN_MTU)
{
nwarn("WARNING: Required buffer size: %u+%u+%u=%u Available=%u\n",
g_uncomp_hdrlen, (fragoffset << 3), paysize,
reqsize, CONFIG_NET_6LOWPAN_MTU);
return -ENOMEM;
}
memcpy(ieee->i_dev.d_buf + g_uncomp_hdrlen + (fragoffset << 3),
fptr + g_frame_hdrlen, paysize);
#ifdef CONFIG_NET_6LOWPAN_FRAG
/* Update ieee->i_accumlen if the frame is a fragment, ieee->i_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.
*/
ieee->i_accumlen = g_uncomp_hdrlen + (fragoffset << 3) + paysize;
}
else
{
ieee->i_pktlen = paysize + g_uncomp_hdrlen;
}
/* If we have a full IP packet in sixlowpan_buf, deliver it to
* the IP stack
*/
ninfo("i_accumlen=%d i_pktlen=%d paysize=%d\n",
ieee->i_accumlen, ieee->i_pktlen, paysize);
if (ieee->i_accumlen == 0 || ieee->i_accumlen >= ieee->i_pktlen)
{
ninfo("IP packet ready (length %d)\n", ieee->i_pktlen);
ieee->i_dev.d_len = ieee->i_pktlen;
ieee->i_pktlen = 0;
ieee->i_accumlen = 0;
return INPUT_COMPLETE;
}
return INPUT_PARTIAL;
#else
/* Deliver the packet to the IP stack */
ieee->i_dev.d_len = paysize + g_uncomp_hdrlen;
return INPUT_COMPLETE;
#endif /* CONFIG_NET_6LOWPAN_FRAG */
}
/****************************************************************************
* Function: sixlowpan_dispatch
*
* Description:
* Inject the packet in d_buf into the network for normal packet processing.
*
* Parameters:
* ieee - The IEEE802.15.4 MAC network driver interface.
*
* Returned Value:
* None
*
****************************************************************************/
static int sixlowpan_dispatch(FAR struct ieee802154_driver_s *ieee)
{
sixlowpan_dumpbuffer("Incoming packet",
(FAR const uint8_t *)IPv6BUF(&ieee->i_dev),
ieee->i_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(&ieee->i_dev);
#endif
/* We only accept IPv6 packets. */
ninfo("Iv6 packet dispatch\n");
NETDEV_RXIPV6(&ieee->i_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.
*/
return ipv6_input(&ieee->i_dev);
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: sixlowpan_input
*
* Description:
* Process an incoming 6loWPAN frame.
*
* This function is called when the device driver has received a 6loWPAN
* frame from the network. The frame from the device driver must be
* provided in a IOB present in the i_framelist: The frame data is in the
* IOB io_data[] buffer and the length of the frame is in the IOB io_len
* field. Only a single IOB is expected in the i_framelist. This incoming
* data will be processed one frame at a time.
*
* An non-NULL d_buf of size CONFIG_NET_6LOWPAN_MTU 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 removed and
* deallocated. i_framelist will be nullified. If reassembly is
* incomplete, this function will return to called with i_framelist
* equal to NULL. The partially reassembled packet must be preserved by
* the IEEE802.15.4 MAC 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 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 the
* 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 in i_framelist as with other
* TX operations.
*
* So from the standpoint of the IEEE802.15.4 MAC driver, there are two
* possible results: (1) i_framelist is NULL meaning that the frame
* was fully processed and freed, or (2) i_framelist is non-NULL meaning
* that there are outgoing frame(s) to be sent.
*
* Input Parameters:
* ieee - The IEEE802.15.4 MAC network driver interface.
*
* Returned Value:
* Ok is returned on success; Othewise a negated errno value is returned.
*
****************************************************************************/
int sixlowpan_input(FAR struct ieee802154_driver_s *ieee)
{
int ret = -EINVAL;
DEBUGASSERT(ieee != NULL && !FRAME_IOB_EMPTY(ieee));
/* Verify that an IOB is provided in the device structure */
while (!FRAME_IOB_EMPTY(ieee))
{
FAR struct iob_s *iob;
/* Remove the IOB containing the frame from the device structure */
FRAME_IOB_REMOVE(ieee, iob);
DEBUGASSERT(iob != NULL);
sixlowpan_dumpbuffer("Incoming frame", iob->io_data, iob->io_len);
/* Process the frame, decompressing it into the packet buffer */
ret = sixlowpan_frame_process(ieee, iob);
/* Free the IOB the held the consumed frame */
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(ieee);
if (ret >= 0)
{
/* Check if this resulted in a request to send an outgoing
* packet.
*/
if (ieee->i_dev.d_len > 0)
{
FAR struct ipv6_hdr_s *ipv6hdr;
FAR uint8_t *buffer;
struct rimeaddr_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(&ieee->i_dev);
/* Get the Rime MAC address of the destination. This
* assumes an encoding of the MAC address in the IPv6
* address.
*/
sixlowpan_rimefromip(ipv6hdr->destipaddr, &destmac);
/* The data payload should follow the IPv6 header plus
* the protocol header.
*/
if (ipv6hdr->proto != IP_PROTO_TCP)
{
FAR struct tcp_hdr_s *tcp = TCPBUF(&ieee->i_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;
}
else if (ipv6hdr->proto != IP_PROTO_UDP)
{
hdrlen = IPv6_HDRLEN + UDP_HDRLEN;
}
else if (ipv6hdr->proto != IP_PROTO_ICMP6)
{
hdrlen = IPv6_HDRLEN + ICMPv6_HDRLEN;
}
else
{
nwarn("WARNING: Unsupported protoype: %u\n",
ipv6hdr->proto);
ret = -EPROTO;
goto drop;
}
if (hdrlen < ieee->i_dev.d_len)
{
nwarn("WARNING: Packet to small: Have %u need >%u\n",
ieee->i_dev.d_len, hdrlen);
ret = -ENOBUFS;
goto drop;
}
/* Convert the outgoing packet into a frame list. */
buffer = ieee->i_dev.d_buf + hdrlen;
buflen = ieee->i_dev.d_len - hdrlen;
ret = sixlowpan_queue_frames(ieee, ipv6hdr, buffer, buflen,
&destmac);
drop:
ieee->i_dev.d_len = 0;
}
}
}
}
return ret;
}
#endif /* CONFIG_NET_6LOWPAN */
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