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Made headercompression work on external buffer

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This commit is contained in:
adamdunkels 2006-10-09 11:53:43 +00:00
parent 17c32fa33e
commit a2befb9dd0
2 changed files with 28 additions and 27 deletions
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47
core/net/hc.c
View File

@ -28,7 +28,7 @@
* *
* This file is part of the Contiki operating system. * This file is part of the Contiki operating system.
* *
* @(#)$Id: hc.c,v 1.2 2006/08/09 16:13:39 bg- Exp $ * @(#)$Id: hc.c,v 1.3 2006/10/09 11:53:43 adamdunkels Exp $
*/ */
/** /**
@ -85,11 +85,11 @@ hc_init(void)
} }
/*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/
/** /**
* Compress the header found in the uip_buf. * Compress a header
* *
* This function compresses the TCP/IP headers in the uip_buf and * This function compresses the TCP/IP headers in a buffer and
* should be called just before sending out data on the network. A * should be called just before sending out data on the network. A
* pointer to the compressed header is returned, and uip_len is * pointer to the compressed header is returned, and len is
* adjusted. * adjusted.
* *
* If the header could not be compressed, the function does nothing * If the header could not be compressed, the function does nothing
@ -100,13 +100,13 @@ hc_init(void)
*/ */
/*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/
int int
hc_compress(void) hc_compress(u8_t *buf, int len)
{ {
struct hc_hdr *hdr; struct hc_hdr *hdr;
struct udpip_hdr *uhdr; struct udpip_hdr *uhdr;
hdr = (struct hc_hdr *)&uip_buf[UIP_LLH_LEN]; hdr = (struct hc_hdr *)buf;
uhdr = (struct udpip_hdr *)&uip_buf[UIP_LLH_LEN]; uhdr = (struct udpip_hdr *)buf;
/* Check the original TCP/IP header to see if it matches our /* Check the original TCP/IP header to see if it matches our
pattern, and compress if it does. */ pattern, and compress if it does. */
@ -139,20 +139,20 @@ hc_compress(void)
/* Move the packet data to the end of the compressed header. */ /* Move the packet data to the end of the compressed header. */
memcpy((char *)hdr + HC_HLEN, memcpy((char *)hdr + HC_HLEN,
&uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN], &buf[UIP_IPUDPH_LEN],
uip_len - UIP_IPUDPH_LEN); len - UIP_IPUDPH_LEN);
/* Return the new packet length. */ /* Return the new packet length. */
return uip_len - (UIP_IPUDPH_LEN - HC_HLEN); return len - (UIP_IPUDPH_LEN - HC_HLEN);
} }
/* No compression possible, return NULL pointer. */ /* No compression possible, return NULL pointer. */
return uip_len; return len;
} }
/*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/
/** /**
* Inflate (decompress) a header in the uip_buf buffer. * Inflate (decompress) a header
* *
* This function should be called to inflate a possibly compressed * This function should be called to inflate a possibly compressed
* packet header just after a packet has been received from the * packet header just after a packet has been received from the
@ -162,37 +162,36 @@ hc_compress(void)
*/ */
/*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/
int int
hc_inflate(void) hc_inflate(u8_t *buf, int len)
{ {
struct udpip_hdr *uhdr; struct udpip_hdr *uhdr;
struct hc_hdr *hdr; struct hc_hdr *hdr;
hdr = (struct hc_hdr *)&uip_buf[UIP_LLH_LEN]; hdr = (struct hc_hdr *)buf;
/* First, check if the header in uip_buf is compressed or not. */ /* First, check if the header in buf is compressed or not. */
if((hdr->flagsport & HTONS(FLAGS_COMPRESSED)) != 0 && if((hdr->flagsport & HTONS(FLAGS_COMPRESSED)) != 0 &&
(hdr->flagsport & HTONS(FLAGS_BROADCASTDATA)) != 0) { (hdr->flagsport & HTONS(FLAGS_BROADCASTDATA)) != 0) {
/* Move packet data in memory to make room for the uncompressed header. */ /* Move packet data in memory to make room for the uncompressed header. */
memmove(&uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN - HC_HLEN], memmove(&buf[UIP_IPUDPH_LEN - HC_HLEN],
&uip_buf[UIP_LLH_LEN], uip_len); buf, len);
uhdr = (struct udpip_hdr *)&uip_buf[UIP_LLH_LEN]; uhdr = (struct udpip_hdr *)buf;
hdr = (struct hc_hdr *)&uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN - hdr = (struct hc_hdr *)&buf[UIP_IPUDPH_LEN - HC_HLEN];
HC_HLEN];
uhdr->srcipaddr = hdr->srcipaddr; uhdr->srcipaddr = hdr->srcipaddr;
uhdr->srcport = hdr->flagsport & HTONS(0x3fff); uhdr->srcport = hdr->flagsport & HTONS(0x3fff);
uhdr->destport = hdr->flagsport & HTONS(0x3fff); uhdr->destport = hdr->flagsport & HTONS(0x3fff);
uhdr->udplen = uip_len; uhdr->udplen = len;
uip_len += UIP_IPUDPH_LEN - HC_HLEN; len += UIP_IPUDPH_LEN - HC_HLEN;
uhdr->vhl = 0x45; uhdr->vhl = 0x45;
uhdr->tos = 0; uhdr->tos = 0;
uhdr->len[0] = 0; uhdr->len[0] = 0;
uhdr->len[1] = uip_len; uhdr->len[1] = len;
uhdr->ipid[0] = uhdr->ipid[1] = 0xAD; uhdr->ipid[0] = uhdr->ipid[1] = 0xAD;
uhdr->ipoffset[0] = uhdr->ipoffset[1] = 0; uhdr->ipoffset[0] = uhdr->ipoffset[1] = 0;
uhdr->ttl = 2; uhdr->ttl = 2;
@ -205,6 +204,6 @@ hc_inflate(void)
} }
return uip_len; return len;
} }
/*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/

8
core/net/hc.h
View File

@ -28,7 +28,7 @@
* *
* This file is part of the Contiki operating system. * This file is part of the Contiki operating system.
* *
* @(#)$Id: hc.h,v 1.1 2006/06/17 22:41:18 adamdunkels Exp $ * @(#)$Id: hc.h,v 1.2 2006/10/09 11:53:43 adamdunkels Exp $
*/ */
/** /**
* \file * \file
@ -40,9 +40,11 @@
#ifndef __HC_H__ #ifndef __HC_H__
#define __HC_H__ #define __HC_H__
#include "net/uip.h"
void hc_init(void); void hc_init(void);
int hc_compress(void); int hc_compress(u8_t *buf, int len);
int hc_inflate(void); int hc_inflate(u8_t *buf, int len);
#define HC_HLEN 6 #define HC_HLEN 6