6lowWPAN: Add frame decompression logic to IEEE802.15.4 input
This commit is contained in:
Gregory Nutt
parent
52ead055fd
commit
7a4af75fcf
@ -53,6 +53,7 @@
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#include <stdint.h>
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#include <nuttx/clock.h>
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#include <nuttx/net/iob.h>
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#include <nuttx/net/netdev.h>
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@ -71,9 +72,13 @@
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#define SIXLOWPAN_DISPATCH_IPV6 0x41 /* 01000001 = 65 */
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#define SIXLOWPAN_DISPATCH_HC1 0x42 /* 01000010 = 66 */
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#define SIXLOWPAN_DISPATCH_IPHC 0x60 /* 011xxxxx = ... */
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#define SIXLOWPAN_DISPATCH_IPHC 0x60 /* 011xxxxx */
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#define SIXLOWPAN_DISPATCH_IPHC_MASK 0xe0 /* 11100000 */
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#define SIXLOWPAN_DISPATCH_FRAG1 0xc0 /* 11000xxx */
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#define SIXLOWPAN_DISPATCH_FRAGN 0xe0 /* 11100xxx */
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#define SIXLOWPAN_DISPATCH_FRAG_MASK 0xf1 /* 11111000 */
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/* HC1 encoding */
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@ -402,6 +407,7 @@ struct ieee802154_driver_s
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FAR struct iob_s *i_framelist;
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/* Driver Configuration ***************************************************/
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/* i_panid. The PAN ID is 16-bit number that identifies the network. It
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* must be unique to differentiate a network. All the nodes in the same
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* network should have the same PAN ID. This value must be provided to
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@ -433,6 +439,42 @@ struct ieee802154_driver_s
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*/
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uint16_t i_dgramtag;
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#if CONFIG_NET_6LOWPAN_FRAG
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/* Fragmentation Support *************************************************/
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/* Fragementation is handled frame by frame and requires that certain
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* state information be retained from frame to frame.
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*/
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/* i_pktlen. The total length of the IPv6 packet to be re-assembled in
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* d_buf.
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*/
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uint16_t i_pktlen;
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/* The current accumulated length of the packet being received in d_buf.
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* Included IPv6 and protocol headers.
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*/
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uint16_t i_accumlen;
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/* i_reasstag. Each frame in the reassembly has a tag. That tag must
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* match the reassembly tag in the fragments being merged.
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*/
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uint16_t i_reasstag;
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/* The source MAC address of the fragments being merged */
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struct rimeaddr_s i_fragsrc;
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/* That time at which reassembly was started. If the elapsed time
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* exceeds CONFIG_NET_6LOWPAN_MAXAGE, then the reassembly will
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* be cancelled.
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*/
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systime_t i_time;
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#endif /* CONFIG_NET_6LOWPAN_FRAG */
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};
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/* The structure of a next header compressor. This compressor is provided
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@ -132,7 +132,8 @@ config NET_6LOWPAN_MAXAGE
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int "Packet reassembly timeout"
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default 20
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---help---
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Timeout for packet reassembly at the 6lowpan layer (should be < 60s)
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Timeout for packet reassembly at the 6lowpan layer in units of
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seconds (should be < 60s)
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config NET_6LOWPAN_MAX_MACTRANSMITS
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int "Max MAC transmissions"
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@ -1,6 +1,6 @@
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/****************************************************************************
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* net/sixlowpan/sixlowpan_input.c
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* 6lowpan implementation (RFC4944 and draft-ietf-6lowpan-hc-06)
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* 6loWPAN implementation (RFC4944 and draft-ietf-6loWPAN-hc-06)
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*
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* Copyright (C) 2017, Gregory Nutt, all rights reserved
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* Author: Gregory Nutt <gnutt@nuttx.org>
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@ -49,10 +49,15 @@
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#include <nuttx/config.h>
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#include <string.h>
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#include <assert.h>
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#include <errno.h>
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#include <debug.h>
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#if CONFIG_NET_6LOWPAN_FRAG
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# include "nuttx/clock.h"
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#endif
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#include "nuttx/net/netdev.h"
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#include "nuttx/net/ip.h"
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#include "nuttx/net/sixlowpan.h"
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@ -74,6 +79,14 @@
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#define INPUT_PARTIAL 0 /* Frame processed successful, packet incomplete */
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#define INPUT_COMPLETE 1 /* Frame processed successful, packet complete */
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/* Re-assembly timeout in clock ticks */
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#define NET_6LOWPAN_TIMEOUT SEC2TICK(CONFIG_NET_6LOWPAN_MAXAGE)
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/* Buffer access helpers */
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#define IPv6BUF(dev) ((FAR struct ipv6_hdr_s *)((dev)->d_buf))
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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@ -185,13 +198,365 @@ static void sixlowpan_set_pktattrs(FAR struct ieee802154_driver_s *ieee,
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* Returned Value:
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* Ok is returned on success; Othewise a negated errno value is returned.
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*
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* Assumptions:
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* Network is locked
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*
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****************************************************************************/
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static int sixlowpan_frame_process(FAR struct ieee802154_driver_s *ieee,
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FAR struct iob_s *iob)
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{
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/* REVISIT: To be provided */
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return -ENOSYS;
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FAR uint8_t *hc1 = RIME_HC1_PTR;
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uint16_t fragsize = 0; /* Size of the IP packet (read from fragment) */
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uint8_t fragoffset = 0; /* Offset of the fragment in the IP packet */
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bool isfrag = false;
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int reqsize; /* Required buffer size */
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#if CONFIG_NET_6LOWPAN_FRAG
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bool isfirstfrag = false;
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bool islastfrag = false;
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uint16_t fragtag = 0; /* Tag of the fragment */
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systime_t elapsed; /* Elapsed time */
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#endif /* CONFIG_NET_6LOWPAN_FRAG */
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/* Initialize global data. Locking the network guarantees that we have
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* exclusive use of the global values for intermediate calculations.
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*/
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g_uncomp_hdrlen = 0;
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g_rime_hdrlen = 0;
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/* The MAC puts the 15.4 payload inside the RIME data buffer */
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g_rimeptr = &iob->io_data[PACKETBUF_HDR_SIZE];
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#if CONFIG_NET_6LOWPAN_FRAG
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/* If reassembly timed out, cancel it */
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elapsed = clock_systimer() - ieee->i_time;
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if (elapsed > NET_6LOWPAN_TIMEOUT)
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{
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nwarn("WARNING: Reassembly timed out\n");
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ieee->i_pktlen = 0;
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ieee->i_accumlen = 0;
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}
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/* Since we don't support the mesh and broadcast header, the first header
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* we look for is the fragmentation header
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*/
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switch ((GETINT16(RIME_FRAG_PTR, RIME_FRAG_DISPATCH_SIZE) & 0xf800) >> 8)
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{
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/* First fragment of new reassembly */
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case SIXLOWPAN_DISPATCH_FRAG1:
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{
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/* Set up for the reassembly */
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fragoffset = 0;
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fragsize = GETINT16(RIME_FRAG_PTR, RIME_FRAG_DISPATCH_SIZE) & 0x07ff;
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fragtag = GETINT16(RIME_FRAG_PTR, RIME_FRAG_TAG);
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ninfo("FRAG1: size %d, tag %d, offset %d\n",
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fragsize, fragtag, fragoffset);
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g_rime_hdrlen += SIXLOWPAN_FRAG1_HDR_LEN;
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/* Indicate the first fragment of the reassembly */
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isfirstfrag = true;
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isfrag = true;
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}
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break;
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case SIXLOWPAN_DISPATCH_FRAGN:
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{
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/* Set offset, tag, size. Offset is in units of 8 bytes. */
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fragoffset = RIME_FRAG_PTR[RIME_FRAG_OFFSET];
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fragtag = GETINT16(RIME_FRAG_PTR, RIME_FRAG_TAG);
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fragsize = GETINT16(RIME_FRAG_PTR, RIME_FRAG_DISPATCH_SIZE) & 0x07ff;
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ninfo("FRAGN: size %d, tag %d, offset %d\n",
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fragsize, fragtag, fragoffset);
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g_rime_hdrlen += SIXLOWPAN_FRAGN_HDR_LEN;
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ninfo("islastfrag?: i_accumlen %d g_rime_payloadlen %d fragsize %d\n",
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ieee->i_accumlen, iob->io_len - g_rime_hdrlen, fragsize);
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/* Indicate that this frame is a another fragment for reassembly */
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isfrag = true;
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/* Check if it is the last fragement to be processed.
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*
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* If this is the last fragment, we may shave off any extrenous
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* bytes at the end. We must be liberal in what we accept.
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*/
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if (ieee->i_accumlen + iob->io_len - g_rime_hdrlen >= fragsize)
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{
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islastfrag = true;
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}
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}
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break;
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/* Not a fragment */
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default:
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break;
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}
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/* Check if we are currently reassembling a packet */
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if (ieee->i_accumlen > 0)
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{
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/* In this case what we expect is that the next frame will hold the
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* next FRAGN of the sequence. We have to handle a few exeptional
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* cases that we need to handle:
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*
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* 1. If we are currently reassembling a packet, but have just received
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* the first fragment of another packet. We can either ignore it and
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* hope to receive the rest of the under-reassembly packet fragments,
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* or we can discard the previous packet altogether, and start
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* reassembling the new packet. Here we discard the previous packet,
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* and start reassembling the new packet.
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* 2. The new frame is not a fragment. We should be able to handle this
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* case, but we cannot because that would require two packet buffers.
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* It could be handled with a more extensive design.
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* 3. The fragment came from a different sender. What would this mean?
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*
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*/
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if (!isfrag)
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{
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/* Discard the partially assembled packet */
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nwarn("WARNING: Non-fragment frame received during reassembly\n");
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ieee->i_pktlen = 0;
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ieee->i_accumlen = 0;
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}
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/* It is a fragment of some kind. Drop any zero length fragments */
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else if (fragsize == 0)
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{
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nwarn("WARNING: Dropping zero-length 6loWPAN fragment\n");
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return OK;
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}
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/* A non-zero, first fragement received while we are in the middle of
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* rassembly. Discard the partially assembled packet and start over.
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*/
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else if (isfirstfrag)
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{
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nwarn("WARNING: First fragment frame received during reassembly\n");
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ieee->i_pktlen = 0;
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ieee->i_accumlen = 0;
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}
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/* Verify that this fragment is part of that reassembly sequence */
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else if (fragsize != ieee->i_pktlen || ieee->i_reasstag != fragtag ||
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!rimeaddr_cmp(&ieee->i_fragsrc, &g_pktaddrs[PACKETBUF_ADDR_SENDER]))
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{
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/* The packet is a fragment that does not belong to the packet
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* being reassembled or the packet is not a fragment.
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*/
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nwarn("WARNING: Dropping 6loWPAN packet that is not a fragment of "
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"the packet currently being reassembled\n");
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return OK;
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}
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/* Looks good. We are currently processing a reassembling sequence and
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* we recieved a valid FRAGN fragment. Skip the header compression
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* dispatch logic.
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*/
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goto copypayload;
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}
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/* There is no reassembly in progress. Check if we received a fragment */
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else if (isfrag)
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{
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/* Another case that we have to handle is if a FRAGN fragment of a
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* reassembly is received, but we are not currently reassembling a
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* packet. I think we have no choice but to drop the packet in this
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* case.
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*/
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if (!isfirstfrag)
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{
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nwarn("WARNING: FRAGN 6loWPAN fragment while not reassembling\n");
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return OK;
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}
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/* Start reassembly if we received a non-zero length, first fragment */
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if (fragsize > 0)
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{
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/* Drop the packet if it cannot fit into the d_buf */
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if (fragsize > CONFIG_NET_6LOWPAN_MTU)
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{
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nwarn("WARNING: Reassembled packet size exeeds CONFIG_NET_6LOWPAN_MTU\n");
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return OK;
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}
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/* Set up for the reassembly */
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ieee->i_pktlen = fragsize;
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ieee->i_reasstag = fragtag;
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ieee->i_time = clock_systimer();
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ninfo("Starting reassembly: i_pktlen %d, i_pktlen %d\n",
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ieee->i_pktlen, ieee->i_reasstag);
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rimeaddr_copy(&ieee->i_fragsrc, &g_pktaddrs[PACKETBUF_ADDR_SENDER]);
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}
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}
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#endif /* CONFIG_NET_6LOWPAN_FRAG */
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/* Process next dispatch and headers */
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#ifdef CONFIG_NET_6LOWPAN_COMPRESSION_HC06
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if ((hc1[RIME_HC1_DISPATCH] & SIXLOWPAN_DISPATCH_IPHC_MASK) == SIXLOWPAN_DISPATCH_IPHC)
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{
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ninfo("IPHC Dispatch\n");
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sixlowpan_uncompresshdr_hc06(ieee, fragsize);
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}
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else
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#endif /* CONFIG_NET_6LOWPAN_COMPRESSION_HC06 */
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#ifdef CONFIG_NET_6LOWPAN_COMPRESSION_HC1
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if (hc1[RIME_HC1_DISPATCH] == SIXLOWPAN_DISPATCH_HC1)
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{
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ninfo("HC1 Dispatch\n");
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sixlowpan_uncompresshdr_hc1(ieee, fragsize);
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}
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else
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#endif /* CONFIG_NET_6LOWPAN_COMPRESSION_HC1 */
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if (hc1[RIME_HC1_DISPATCH] == SIXLOWPAN_DISPATCH_IPV6)
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{
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ninfo("IPV6 Dispatch\n");
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g_rime_hdrlen += SIXLOWPAN_IPV6_HDR_LEN;
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/* Put uncompressed IP header in d_buf. */
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memcpy(ieee->i_dev.d_buf, g_rimeptr + g_rime_hdrlen, IPv6_HDRLEN);
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/* Update g_uncomp_hdrlen and g_rime_hdrlen. */
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g_rime_hdrlen += IPv6_HDRLEN;
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g_uncomp_hdrlen += IPv6_HDRLEN;
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}
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else
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{
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/* Unknown or unsupported header */
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nwarn("WARNING unknown dispatch: %u\n", hc1[RIME_HC1_DISPATCH]);
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return OK;
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}
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#if CONFIG_NET_6LOWPAN_FRAG
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copypayload:
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#endif /* CONFIG_NET_6LOWPAN_FRAG */
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/* Copy "payload" from the rime buffer to the d_buf. If this frame is a
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* first fragment or not part of a fragmented packet, we have already
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* copied the compressed headers, g_uncomp_hdrlen and g_rime_hdrlen are
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* non-zerio, fragoffset is.
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*/
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if (ieee->i_dev.d_len < g_rime_hdrlen)
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{
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ninfo("SIXLOWPAN: packet dropped due to header > total packet\n");
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return OK;
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}
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g_rime_payloadlen = ieee->i_dev.d_len - g_rime_hdrlen;
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/* Sanity-check size of incoming packet to avoid buffer overflow */
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reqsize = g_uncomp_hdrlen + (uint16_t) (fragoffset << 3) + g_rime_payloadlen;
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if (reqsize > CONFIG_NET_6LOWPAN_MTU)
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{
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ninfo("Required buffer size: %d+%d+%d=%d Available: %d\n",
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g_uncomp_hdrlen, (int)(fragoffset << 3), g_rime_payloadlen,
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reqsize, CONFIG_NET_6LOWPAN_MTU);
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return OK;
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}
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memcpy((FAR uint8_t *)ieee->i_dev.d_buf + g_uncomp_hdrlen +
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(int)(fragoffset << 3), g_rimeptr + g_rime_hdrlen,
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g_rime_payloadlen);
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#if CONFIG_NET_6LOWPAN_FRAG
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/* Update ieee->i_accumlen if the frame is a fragment, ieee->i_pktlen
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* otherwise.
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*/
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if (isfrag)
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{
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/* Add the size of the header only for the first fragment. */
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if (isfirstfrag)
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{
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ieee->i_accumlen += g_uncomp_hdrlen;
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}
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/* For the last fragment, we are OK if there is extraneous bytes at the
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* end of the packet.
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*/
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if (islastfrag)
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{
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ieee->i_accumlen = fragsize;
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}
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else
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{
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ieee->i_accumlen += g_rime_payloadlen;
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}
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ninfo("i_accumlen %d, g_rime_payloadlen %d\n",
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ieee->i_accumlen, g_rime_payloadlen);
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}
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else
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#endif /* CONFIG_NET_6LOWPAN_FRAG */
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{
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ieee->i_pktlen = g_rime_payloadlen + g_uncomp_hdrlen;
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}
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#if CONFIG_NET_6LOWPAN_FRAG
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/* If we have a full IP packet in sixlowpan_buf, deliver it to
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* the IP stack
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*/
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ninfo("sixlowpan_init i_accumlen %d, ieee->i_pktlen %d\n",
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ieee->i_accumlen, ieee->i_pktlen);
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if (ieee->i_accumlen == 0 || ieee->i_accumlen == ieee->i_pktlen)
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{
|
||||
FAR struct ipv6_hdr_s *ipv6 = IPv6BUF(&ieee->i_dev);
|
||||
|
||||
ninfo("IP packet ready (length %d)\n", ieee->i_pktlen);
|
||||
|
||||
/* REVISIT -- clearly wrong. */
|
||||
memcpy((FAR uint8_t *)ipv6, (FAR uint8_t *)ipv6, ieee->i_pktlen);
|
||||
|
||||
ieee->i_pktlen = 0;
|
||||
ieee->i_accumlen = 0;
|
||||
|
||||
}
|
||||
#endif /* CONFIG_NET_6LOWPAN_FRAG */
|
||||
|
||||
ninfodumpbuffer("IPv6 header", IPv6BUF(ieee->i_dev), IPv6_HDRLEN)
|
||||
return OK;
|
||||
}
|
||||
|
||||
/****************************************************************************
|
||||
|
||||
@ -54,6 +54,17 @@
|
||||
|
||||
#ifdef CONFIG_NET_6LOWPAN
|
||||
|
||||
/****************************************************************************
|
||||
* Pre-processor Definitions
|
||||
****************************************************************************/
|
||||
|
||||
/* These are temporary stubs. Something like this would be needed to
|
||||
* monitor the health of a IPv6 neighbor.
|
||||
*/
|
||||
|
||||
#define neighbor_reachable(dev)
|
||||
#define neighbor_notreachable(dev)
|
||||
|
||||
/****************************************************************************
|
||||
* Private Types
|
||||
****************************************************************************/
|
||||
@ -172,6 +183,7 @@ static uint16_t send_interrupt(FAR struct net_driver_s *dev,
|
||||
sinfo->s_destmac);
|
||||
|
||||
flags &= ~WPAN_POLL;
|
||||
neighbor_reachable(dev);
|
||||
goto end_wait;
|
||||
}
|
||||
|
||||
@ -183,6 +195,7 @@ static uint16_t send_interrupt(FAR struct net_driver_s *dev,
|
||||
|
||||
nwarn("WARNING: SEND timeout\n");
|
||||
sinfo->s_result = -ETIMEDOUT;
|
||||
neighbor_notreachable(dev);
|
||||
goto end_wait;
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user