Made headercompression work on external buffer

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

View File

@ -28,7 +28,7 @@
*
* 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
* pointer to the compressed header is returned, and uip_len is
* pointer to the compressed header is returned, and len is
* adjusted.
*
* If the header could not be compressed, the function does nothing
@ -100,13 +100,13 @@ hc_init(void)
*/
/*---------------------------------------------------------------------------*/
int
hc_compress(void)
hc_compress(u8_t *buf, int len)
{
struct hc_hdr *hdr;
struct udpip_hdr *uhdr;
hdr = (struct hc_hdr *)&uip_buf[UIP_LLH_LEN];
uhdr = (struct udpip_hdr *)&uip_buf[UIP_LLH_LEN];
hdr = (struct hc_hdr *)buf;
uhdr = (struct udpip_hdr *)buf;
/* Check the original TCP/IP header to see if it matches our
pattern, and compress if it does. */
@ -139,20 +139,20 @@ hc_compress(void)
/* Move the packet data to the end of the compressed header. */
memcpy((char *)hdr + HC_HLEN,
&uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN],
uip_len - UIP_IPUDPH_LEN);
&buf[UIP_IPUDPH_LEN],
len - UIP_IPUDPH_LEN);
/* 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. */
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
* packet header just after a packet has been received from the
@ -162,37 +162,36 @@ hc_compress(void)
*/
/*---------------------------------------------------------------------------*/
int
hc_inflate(void)
hc_inflate(u8_t *buf, int len)
{
struct udpip_hdr *uhdr;
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 &&
(hdr->flagsport & HTONS(FLAGS_BROADCASTDATA)) != 0) {
/* Move packet data in memory to make room for the uncompressed header. */
memmove(&uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN - HC_HLEN],
&uip_buf[UIP_LLH_LEN], uip_len);
uhdr = (struct udpip_hdr *)&uip_buf[UIP_LLH_LEN];
hdr = (struct hc_hdr *)&uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN -
HC_HLEN];
memmove(&buf[UIP_IPUDPH_LEN - HC_HLEN],
buf, len);
uhdr = (struct udpip_hdr *)buf;
hdr = (struct hc_hdr *)&buf[UIP_IPUDPH_LEN - HC_HLEN];
uhdr->srcipaddr = hdr->srcipaddr;
uhdr->srcport = 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->tos = 0;
uhdr->len[0] = 0;
uhdr->len[1] = uip_len;
uhdr->len[1] = len;
uhdr->ipid[0] = uhdr->ipid[1] = 0xAD;
uhdr->ipoffset[0] = uhdr->ipoffset[1] = 0;
uhdr->ttl = 2;
@ -205,6 +204,6 @@ hc_inflate(void)
}
return uip_len;
return len;
}
/*---------------------------------------------------------------------------*/

View File

@ -28,7 +28,7 @@
*
* 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
@ -40,9 +40,11 @@
#ifndef __HC_H__
#define __HC_H__
#include "net/uip.h"
void hc_init(void);
int hc_compress(void);
int hc_inflate(void);
int hc_compress(u8_t *buf, int len);
int hc_inflate(u8_t *buf, int len);
#define HC_HLEN 6