| User | Revision | Line number | New contents of line |
|---|
| mbed714 |
0:d616ece2d859
|
1
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/*
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| mbed714 |
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|
2
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* Routines to compress and uncompess tcp packets (for transmission
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| mbed714 |
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3
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* over low speed serial lines.
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| mbed714 |
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*
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| mbed714 |
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* Copyright (c) 1989 Regents of the University of California.
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| mbed714 |
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* All rights reserved.
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| mbed714 |
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|
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*
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* Redistribution and use in source and binary forms are permitted
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| mbed714 |
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|
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* provided that the above copyright notice and this paragraph are
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| mbed714 |
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|
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* duplicated in all such forms and that any documentation,
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| mbed714 |
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* advertising materials, and other materials related to such
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| mbed714 |
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* distribution and use acknowledge that the software was developed
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| mbed714 |
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* by the University of California, Berkeley. The name of the
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| mbed714 |
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* University may not be used to endorse or promote products derived
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| mbed714 |
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* from this software without specific prior written permission.
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| mbed714 |
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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| mbed714 |
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* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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| mbed714 |
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* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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| mbed714 |
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*
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| mbed714 |
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* Van Jacobson (van@helios.ee.lbl.gov), Dec 31, 1989:
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| mbed714 |
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* Initial distribution.
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| mbed714 |
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*
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| mbed714 |
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* Modified June 1993 by Paul Mackerras, paulus@cs.anu.edu.au,
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| mbed714 |
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* so that the entire packet being decompressed doesn't have
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| mbed714 |
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* to be in contiguous memory (just the compressed header).
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| mbed714 |
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*
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| mbed714 |
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|
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* Modified March 1998 by Guy Lancaster, glanca@gesn.com,
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| mbed714 |
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* for a 16 bit processor.
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*/
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| mbed714 |
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#include "lwip/opt.h"
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| mbed714 |
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32
|
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| mbed714 |
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#if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */
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| mbed714 |
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34
|
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| mbed714 |
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#include "ppp.h"
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| mbed714 |
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#include "pppdebug.h"
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| mbed714 |
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|
37
|
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| mbed714 |
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38
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#include "vj.h"
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| mbed714 |
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|
39
|
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| mbed714 |
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#include <string.h>
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|
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| mbed714 |
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#if VJ_SUPPORT
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| mbed714 |
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|
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|
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| mbed714 |
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|
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#if LINK_STATS
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| mbed714 |
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|
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#define INCR(counter) ++comp->stats.counter
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| mbed714 |
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|
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#else
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| mbed714 |
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#define INCR(counter)
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| mbed714 |
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|
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#endif
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| mbed714 |
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|
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|
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| mbed714 |
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void
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| mbed714 |
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vj_compress_init(struct vjcompress *comp)
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| mbed714 |
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{
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| mbed714 |
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|
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register u_char i;
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| mbed714 |
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|
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register struct cstate *tstate = comp->tstate;
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| mbed714 |
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|
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| mbed714 |
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#if MAX_SLOTS == 0
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| mbed714 |
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memset((char *)comp, 0, sizeof(*comp));
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| mbed714 |
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#endif
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| mbed714 |
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|
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comp->maxSlotIndex = MAX_SLOTS - 1;
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| mbed714 |
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comp->compressSlot = 0; /* Disable slot ID compression by default. */
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| mbed714 |
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for (i = MAX_SLOTS - 1; i > 0; --i) {
|
| mbed714 |
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|
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tstate[i].cs_id = i;
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| mbed714 |
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|
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tstate[i].cs_next = &tstate[i - 1];
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| mbed714 |
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|
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}
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| mbed714 |
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|
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tstate[0].cs_next = &tstate[MAX_SLOTS - 1];
|
| mbed714 |
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|
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|
tstate[0].cs_id = 0;
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| mbed714 |
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|
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comp->last_cs = &tstate[0];
|
| mbed714 |
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|
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comp->last_recv = 255;
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| mbed714 |
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|
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comp->last_xmit = 255;
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| mbed714 |
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|
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comp->flags = VJF_TOSS;
|
| mbed714 |
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|
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}
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| mbed714 |
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|
72
|
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| mbed714 |
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73
|
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| mbed714 |
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/* ENCODE encodes a number that is known to be non-zero. ENCODEZ
|
| mbed714 |
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|
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* checks for zero (since zero has to be encoded in the long, 3 byte
|
| mbed714 |
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|
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* form).
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| mbed714 |
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|
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*/
|
| mbed714 |
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|
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#define ENCODE(n) { \
|
| mbed714 |
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|
79
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if ((u_short)(n) >= 256) { \
|
| mbed714 |
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|
80
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*cp++ = 0; \
|
| mbed714 |
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|
81
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cp[1] = (u_char)(n); \
|
| mbed714 |
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|
82
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cp[0] = (u_char)((n) >> 8); \
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| mbed714 |
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|
83
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cp += 2; \
|
| mbed714 |
0:d616ece2d859
|
84
|
} else { \
|
| mbed714 |
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|
85
|
*cp++ = (u_char)(n); \
|
| mbed714 |
0:d616ece2d859
|
86
|
} \
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| mbed714 |
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|
87
|
}
|
| mbed714 |
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|
88
|
#define ENCODEZ(n) { \
|
| mbed714 |
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|
89
|
if ((u_short)(n) >= 256 || (u_short)(n) == 0) { \
|
| mbed714 |
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|
90
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*cp++ = 0; \
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| mbed714 |
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|
91
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cp[1] = (u_char)(n); \
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| mbed714 |
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92
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cp[0] = (u_char)((n) >> 8); \
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| mbed714 |
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|
93
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cp += 2; \
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| mbed714 |
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|
94
|
} else { \
|
| mbed714 |
0:d616ece2d859
|
95
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*cp++ = (u_char)(n); \
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| mbed714 |
0:d616ece2d859
|
96
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} \
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| mbed714 |
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|
97
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}
|
| mbed714 |
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|
98
|
|
| mbed714 |
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|
99
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#define DECODEL(f) { \
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| mbed714 |
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|
100
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if (*cp == 0) {\
|
| mbed714 |
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|
101
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u32_t tmp = ntohl(f) + ((cp[1] << 8) | cp[2]); \
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| mbed714 |
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|
102
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(f) = htonl(tmp); \
|
| mbed714 |
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|
103
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cp += 3; \
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| mbed714 |
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|
104
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} else { \
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| mbed714 |
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|
105
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u32_t tmp = ntohl(f) + (u32_t)*cp++; \
|
| mbed714 |
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|
106
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(f) = htonl(tmp); \
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| mbed714 |
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|
107
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} \
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| mbed714 |
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|
108
|
}
|
| mbed714 |
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|
109
|
|
| mbed714 |
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|
110
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#define DECODES(f) { \
|
| mbed714 |
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|
111
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if (*cp == 0) {\
|
| mbed714 |
0:d616ece2d859
|
112
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u_short tmp = ntohs(f) + (((u_short)cp[1] << 8) | cp[2]); \
|
| mbed714 |
0:d616ece2d859
|
113
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(f) = htons(tmp); \
|
| mbed714 |
0:d616ece2d859
|
114
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cp += 3; \
|
| mbed714 |
0:d616ece2d859
|
115
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} else { \
|
| mbed714 |
0:d616ece2d859
|
116
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u_short tmp = ntohs(f) + (u_short)*cp++; \
|
| mbed714 |
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|
117
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(f) = htons(tmp); \
|
| mbed714 |
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|
118
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} \
|
| mbed714 |
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|
119
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}
|
| mbed714 |
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|
120
|
|
| mbed714 |
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|
121
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#define DECODEU(f) { \
|
| mbed714 |
0:d616ece2d859
|
122
|
if (*cp == 0) {\
|
| mbed714 |
0:d616ece2d859
|
123
|
(f) = htons(((u_short)cp[1] << 8) | cp[2]); \
|
| mbed714 |
0:d616ece2d859
|
124
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cp += 3; \
|
| mbed714 |
0:d616ece2d859
|
125
|
} else { \
|
| mbed714 |
0:d616ece2d859
|
126
|
(f) = htons((u_short)*cp++); \
|
| mbed714 |
0:d616ece2d859
|
127
|
} \
|
| mbed714 |
0:d616ece2d859
|
128
|
}
|
| mbed714 |
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|
129
|
|
| mbed714 |
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|
130
|
/*
|
| mbed714 |
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|
131
|
* vj_compress_tcp - Attempt to do Van Jacobson header compression on a
|
| mbed714 |
0:d616ece2d859
|
132
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* packet. This assumes that nb and comp are not null and that the first
|
| mbed714 |
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|
133
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* buffer of the chain contains a valid IP header.
|
| mbed714 |
0:d616ece2d859
|
134
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* Return the VJ type code indicating whether or not the packet was
|
| mbed714 |
0:d616ece2d859
|
135
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* compressed.
|
| mbed714 |
0:d616ece2d859
|
136
|
*/
|
| mbed714 |
0:d616ece2d859
|
137
|
u_int
|
| mbed714 |
0:d616ece2d859
|
138
|
vj_compress_tcp(struct vjcompress *comp, struct pbuf *pb)
|
| mbed714 |
0:d616ece2d859
|
139
|
{
|
| mbed714 |
0:d616ece2d859
|
140
|
register struct ip_hdr *ip = (struct ip_hdr *)pb->payload;
|
| mbed714 |
0:d616ece2d859
|
141
|
register struct cstate *cs = comp->last_cs->cs_next;
|
| mbed714 |
0:d616ece2d859
|
142
|
register u_short hlen = IPH_HL(ip);
|
| mbed714 |
0:d616ece2d859
|
143
|
register struct tcp_hdr *oth;
|
| mbed714 |
0:d616ece2d859
|
144
|
register struct tcp_hdr *th;
|
| mbed714 |
0:d616ece2d859
|
145
|
register u_short deltaS, deltaA;
|
| mbed714 |
0:d616ece2d859
|
146
|
register u_long deltaL;
|
| mbed714 |
0:d616ece2d859
|
147
|
register u_int changes = 0;
|
| mbed714 |
0:d616ece2d859
|
148
|
u_char new_seq[16];
|
| mbed714 |
0:d616ece2d859
|
149
|
register u_char *cp = new_seq;
|
| mbed714 |
0:d616ece2d859
|
150
|
|
| mbed714 |
0:d616ece2d859
|
151
|
/*
|
| mbed714 |
0:d616ece2d859
|
152
|
* Check that the packet is IP proto TCP.
|
| mbed714 |
0:d616ece2d859
|
153
|
*/
|
| mbed714 |
0:d616ece2d859
|
154
|
if (IPH_PROTO(ip) != IP_PROTO_TCP) {
|
| mbed714 |
0:d616ece2d859
|
155
|
return (TYPE_IP);
|
| mbed714 |
0:d616ece2d859
|
156
|
}
|
| mbed714 |
0:d616ece2d859
|
157
|
|
| mbed714 |
0:d616ece2d859
|
158
|
/*
|
| mbed714 |
0:d616ece2d859
|
159
|
* Bail if this is an IP fragment or if the TCP packet isn't
|
| mbed714 |
0:d616ece2d859
|
160
|
* `compressible' (i.e., ACK isn't set or some other control bit is
|
| mbed714 |
0:d616ece2d859
|
161
|
* set).
|
| mbed714 |
0:d616ece2d859
|
162
|
*/
|
| mbed714 |
0:d616ece2d859
|
163
|
if ((IPH_OFFSET(ip) & PP_HTONS(0x3fff)) || pb->tot_len < 40) {
|
| mbed714 |
0:d616ece2d859
|
164
|
return (TYPE_IP);
|
| mbed714 |
0:d616ece2d859
|
165
|
}
|
| mbed714 |
0:d616ece2d859
|
166
|
th = (struct tcp_hdr *)&((long *)ip)[hlen];
|
| mbed714 |
0:d616ece2d859
|
167
|
if ((TCPH_FLAGS(th) & (TCP_SYN|TCP_FIN|TCP_RST|TCP_ACK)) != TCP_ACK) {
|
| mbed714 |
0:d616ece2d859
|
168
|
return (TYPE_IP);
|
| mbed714 |
0:d616ece2d859
|
169
|
}
|
| mbed714 |
0:d616ece2d859
|
170
|
/*
|
| mbed714 |
0:d616ece2d859
|
171
|
* Packet is compressible -- we're going to send either a
|
| mbed714 |
0:d616ece2d859
|
172
|
* COMPRESSED_TCP or UNCOMPRESSED_TCP packet. Either way we need
|
| mbed714 |
0:d616ece2d859
|
173
|
* to locate (or create) the connection state. Special case the
|
| mbed714 |
0:d616ece2d859
|
174
|
* most recently used connection since it's most likely to be used
|
| mbed714 |
0:d616ece2d859
|
175
|
* again & we don't have to do any reordering if it's used.
|
| mbed714 |
0:d616ece2d859
|
176
|
*/
|
| mbed714 |
0:d616ece2d859
|
177
|
INCR(vjs_packets);
|
| mbed714 |
0:d616ece2d859
|
178
|
if (!ip_addr_cmp(&ip->src, &cs->cs_ip.src)
|
| mbed714 |
0:d616ece2d859
|
179
|
|| !ip_addr_cmp(&ip->dest, &cs->cs_ip.dest)
|
| mbed714 |
0:d616ece2d859
|
180
|
|| *(long *)th != ((long *)&cs->cs_ip)[IPH_HL(&cs->cs_ip)]) {
|
| mbed714 |
0:d616ece2d859
|
181
|
/*
|
| mbed714 |
0:d616ece2d859
|
182
|
* Wasn't the first -- search for it.
|
| mbed714 |
0:d616ece2d859
|
183
|
*
|
| mbed714 |
0:d616ece2d859
|
184
|
* States are kept in a circularly linked list with
|
| mbed714 |
0:d616ece2d859
|
185
|
* last_cs pointing to the end of the list. The
|
| mbed714 |
0:d616ece2d859
|
186
|
* list is kept in lru order by moving a state to the
|
| mbed714 |
0:d616ece2d859
|
187
|
* head of the list whenever it is referenced. Since
|
| mbed714 |
0:d616ece2d859
|
188
|
* the list is short and, empirically, the connection
|
| mbed714 |
0:d616ece2d859
|
189
|
* we want is almost always near the front, we locate
|
| mbed714 |
0:d616ece2d859
|
190
|
* states via linear search. If we don't find a state
|
| mbed714 |
0:d616ece2d859
|
191
|
* for the datagram, the oldest state is (re-)used.
|
| mbed714 |
0:d616ece2d859
|
192
|
*/
|
| mbed714 |
0:d616ece2d859
|
193
|
register struct cstate *lcs;
|
| mbed714 |
0:d616ece2d859
|
194
|
register struct cstate *lastcs = comp->last_cs;
|
| mbed714 |
0:d616ece2d859
|
195
|
|
| mbed714 |
0:d616ece2d859
|
196
|
do {
|
| mbed714 |
0:d616ece2d859
|
197
|
lcs = cs; cs = cs->cs_next;
|
| mbed714 |
0:d616ece2d859
|
198
|
INCR(vjs_searches);
|
| mbed714 |
0:d616ece2d859
|
199
|
if (ip_addr_cmp(&ip->src, &cs->cs_ip.src)
|
| mbed714 |
0:d616ece2d859
|
200
|
&& ip_addr_cmp(&ip->dest, &cs->cs_ip.dest)
|
| mbed714 |
0:d616ece2d859
|
201
|
&& *(long *)th == ((long *)&cs->cs_ip)[IPH_HL(&cs->cs_ip)]) {
|
| mbed714 |
0:d616ece2d859
|
202
|
goto found;
|
| mbed714 |
0:d616ece2d859
|
203
|
}
|
| mbed714 |
0:d616ece2d859
|
204
|
} while (cs != lastcs);
|
| mbed714 |
0:d616ece2d859
|
205
|
|
| mbed714 |
0:d616ece2d859
|
206
|
/*
|
| mbed714 |
0:d616ece2d859
|
207
|
* Didn't find it -- re-use oldest cstate. Send an
|
| mbed714 |
0:d616ece2d859
|
208
|
* uncompressed packet that tells the other side what
|
| mbed714 |
0:d616ece2d859
|
209
|
* connection number we're using for this conversation.
|
| mbed714 |
0:d616ece2d859
|
210
|
* Note that since the state list is circular, the oldest
|
| mbed714 |
0:d616ece2d859
|
211
|
* state points to the newest and we only need to set
|
| mbed714 |
0:d616ece2d859
|
212
|
* last_cs to update the lru linkage.
|
| mbed714 |
0:d616ece2d859
|
213
|
*/
|
| mbed714 |
0:d616ece2d859
|
214
|
INCR(vjs_misses);
|
| mbed714 |
0:d616ece2d859
|
215
|
comp->last_cs = lcs;
|
| mbed714 |
0:d616ece2d859
|
216
|
hlen += TCPH_OFFSET(th);
|
| mbed714 |
0:d616ece2d859
|
217
|
hlen <<= 2;
|
| mbed714 |
0:d616ece2d859
|
218
|
/* Check that the IP/TCP headers are contained in the first buffer. */
|
| mbed714 |
0:d616ece2d859
|
219
|
if (hlen > pb->len) {
|
| mbed714 |
0:d616ece2d859
|
220
|
return (TYPE_IP);
|
| mbed714 |
0:d616ece2d859
|
221
|
}
|
| mbed714 |
0:d616ece2d859
|
222
|
goto uncompressed;
|
| mbed714 |
0:d616ece2d859
|
223
|
|
| mbed714 |
0:d616ece2d859
|
224
|
found:
|
| mbed714 |
0:d616ece2d859
|
225
|
/*
|
| mbed714 |
0:d616ece2d859
|
226
|
* Found it -- move to the front on the connection list.
|
| mbed714 |
0:d616ece2d859
|
227
|
*/
|
| mbed714 |
0:d616ece2d859
|
228
|
if (cs == lastcs) {
|
| mbed714 |
0:d616ece2d859
|
229
|
comp->last_cs = lcs;
|
| mbed714 |
0:d616ece2d859
|
230
|
} else {
|
| mbed714 |
0:d616ece2d859
|
231
|
lcs->cs_next = cs->cs_next;
|
| mbed714 |
0:d616ece2d859
|
232
|
cs->cs_next = lastcs->cs_next;
|
| mbed714 |
0:d616ece2d859
|
233
|
lastcs->cs_next = cs;
|
| mbed714 |
0:d616ece2d859
|
234
|
}
|
| mbed714 |
0:d616ece2d859
|
235
|
}
|
| mbed714 |
0:d616ece2d859
|
236
|
|
| mbed714 |
0:d616ece2d859
|
237
|
oth = (struct tcp_hdr *)&((long *)&cs->cs_ip)[hlen];
|
| mbed714 |
0:d616ece2d859
|
238
|
deltaS = hlen;
|
| mbed714 |
0:d616ece2d859
|
239
|
hlen += TCPH_OFFSET(th);
|
| mbed714 |
0:d616ece2d859
|
240
|
hlen <<= 2;
|
| mbed714 |
0:d616ece2d859
|
241
|
/* Check that the IP/TCP headers are contained in the first buffer. */
|
| mbed714 |
0:d616ece2d859
|
242
|
if (hlen > pb->len) {
|
| mbed714 |
0:d616ece2d859
|
243
|
PPPDEBUG(LOG_INFO, ("vj_compress_tcp: header len %d spans buffers\n", hlen));
|
| mbed714 |
0:d616ece2d859
|
244
|
return (TYPE_IP);
|
| mbed714 |
0:d616ece2d859
|
245
|
}
|
| mbed714 |
0:d616ece2d859
|
246
|
|
| mbed714 |
0:d616ece2d859
|
247
|
/*
|
| mbed714 |
0:d616ece2d859
|
248
|
* Make sure that only what we expect to change changed. The first
|
| mbed714 |
0:d616ece2d859
|
249
|
* line of the `if' checks the IP protocol version, header length &
|
| mbed714 |
0:d616ece2d859
|
250
|
* type of service. The 2nd line checks the "Don't fragment" bit.
|
| mbed714 |
0:d616ece2d859
|
251
|
* The 3rd line checks the time-to-live and protocol (the protocol
|
| mbed714 |
0:d616ece2d859
|
252
|
* check is unnecessary but costless). The 4th line checks the TCP
|
| mbed714 |
0:d616ece2d859
|
253
|
* header length. The 5th line checks IP options, if any. The 6th
|
| mbed714 |
0:d616ece2d859
|
254
|
* line checks TCP options, if any. If any of these things are
|
| mbed714 |
0:d616ece2d859
|
255
|
* different between the previous & current datagram, we send the
|
| mbed714 |
0:d616ece2d859
|
256
|
* current datagram `uncompressed'.
|
| mbed714 |
0:d616ece2d859
|
257
|
*/
|
| mbed714 |
0:d616ece2d859
|
258
|
if (((u_short *)ip)[0] != ((u_short *)&cs->cs_ip)[0]
|
| mbed714 |
0:d616ece2d859
|
259
|
|| ((u_short *)ip)[3] != ((u_short *)&cs->cs_ip)[3]
|
| mbed714 |
0:d616ece2d859
|
260
|
|| ((u_short *)ip)[4] != ((u_short *)&cs->cs_ip)[4]
|
| mbed714 |
0:d616ece2d859
|
261
|
|| TCPH_OFFSET(th) != TCPH_OFFSET(oth)
|
| mbed714 |
0:d616ece2d859
|
262
|
|| (deltaS > 5 && BCMP(ip + 1, &cs->cs_ip + 1, (deltaS - 5) << 2))
|
| mbed714 |
0:d616ece2d859
|
263
|
|| (TCPH_OFFSET(th) > 5 && BCMP(th + 1, oth + 1, (TCPH_OFFSET(th) - 5) << 2))) {
|
| mbed714 |
0:d616ece2d859
|
264
|
goto uncompressed;
|
| mbed714 |
0:d616ece2d859
|
265
|
}
|
| mbed714 |
0:d616ece2d859
|
266
|
|
| mbed714 |
0:d616ece2d859
|
267
|
/*
|
| mbed714 |
0:d616ece2d859
|
268
|
* Figure out which of the changing fields changed. The
|
| mbed714 |
0:d616ece2d859
|
269
|
* receiver expects changes in the order: urgent, window,
|
| mbed714 |
0:d616ece2d859
|
270
|
* ack, seq (the order minimizes the number of temporaries
|
| mbed714 |
0:d616ece2d859
|
271
|
* needed in this section of code).
|
| mbed714 |
0:d616ece2d859
|
272
|
*/
|
| mbed714 |
0:d616ece2d859
|
273
|
if (TCPH_FLAGS(th) & TCP_URG) {
|
| mbed714 |
0:d616ece2d859
|
274
|
deltaS = ntohs(th->urgp);
|
| mbed714 |
0:d616ece2d859
|
275
|
ENCODEZ(deltaS);
|
| mbed714 |
0:d616ece2d859
|
276
|
changes |= NEW_U;
|
| mbed714 |
0:d616ece2d859
|
277
|
} else if (th->urgp != oth->urgp) {
|
| mbed714 |
0:d616ece2d859
|
278
|
/* argh! URG not set but urp changed -- a sensible
|
| mbed714 |
0:d616ece2d859
|
279
|
* implementation should never do this but RFC793
|
| mbed714 |
0:d616ece2d859
|
280
|
* doesn't prohibit the change so we have to deal
|
| mbed714 |
0:d616ece2d859
|
281
|
* with it. */
|
| mbed714 |
0:d616ece2d859
|
282
|
goto uncompressed;
|
| mbed714 |
0:d616ece2d859
|
283
|
}
|
| mbed714 |
0:d616ece2d859
|
284
|
|
| mbed714 |
0:d616ece2d859
|
285
|
if ((deltaS = (u_short)(ntohs(th->wnd) - ntohs(oth->wnd))) != 0) {
|
| mbed714 |
0:d616ece2d859
|
286
|
ENCODE(deltaS);
|
| mbed714 |
0:d616ece2d859
|
287
|
changes |= NEW_W;
|
| mbed714 |
0:d616ece2d859
|
288
|
}
|
| mbed714 |
0:d616ece2d859
|
289
|
|
| mbed714 |
0:d616ece2d859
|
290
|
if ((deltaL = ntohl(th->ackno) - ntohl(oth->ackno)) != 0) {
|
| mbed714 |
0:d616ece2d859
|
291
|
if (deltaL > 0xffff) {
|
| mbed714 |
0:d616ece2d859
|
292
|
goto uncompressed;
|
| mbed714 |
0:d616ece2d859
|
293
|
}
|
| mbed714 |
0:d616ece2d859
|
294
|
deltaA = (u_short)deltaL;
|
| mbed714 |
0:d616ece2d859
|
295
|
ENCODE(deltaA);
|
| mbed714 |
0:d616ece2d859
|
296
|
changes |= NEW_A;
|
| mbed714 |
0:d616ece2d859
|
297
|
}
|
| mbed714 |
0:d616ece2d859
|
298
|
|
| mbed714 |
0:d616ece2d859
|
299
|
if ((deltaL = ntohl(th->seqno) - ntohl(oth->seqno)) != 0) {
|
| mbed714 |
0:d616ece2d859
|
300
|
if (deltaL > 0xffff) {
|
| mbed714 |
0:d616ece2d859
|
301
|
goto uncompressed;
|
| mbed714 |
0:d616ece2d859
|
302
|
}
|
| mbed714 |
0:d616ece2d859
|
303
|
deltaS = (u_short)deltaL;
|
| mbed714 |
0:d616ece2d859
|
304
|
ENCODE(deltaS);
|
| mbed714 |
0:d616ece2d859
|
305
|
changes |= NEW_S;
|
| mbed714 |
0:d616ece2d859
|
306
|
}
|
| mbed714 |
0:d616ece2d859
|
307
|
|
| mbed714 |
0:d616ece2d859
|
308
|
switch(changes) {
|
| mbed714 |
0:d616ece2d859
|
309
|
case 0:
|
| mbed714 |
0:d616ece2d859
|
310
|
/*
|
| mbed714 |
0:d616ece2d859
|
311
|
* Nothing changed. If this packet contains data and the
|
| mbed714 |
0:d616ece2d859
|
312
|
* last one didn't, this is probably a data packet following
|
| mbed714 |
0:d616ece2d859
|
313
|
* an ack (normal on an interactive connection) and we send
|
| mbed714 |
0:d616ece2d859
|
314
|
* it compressed. Otherwise it's probably a retransmit,
|
| mbed714 |
0:d616ece2d859
|
315
|
* retransmitted ack or window probe. Send it uncompressed
|
| mbed714 |
0:d616ece2d859
|
316
|
* in case the other side missed the compressed version.
|
| mbed714 |
0:d616ece2d859
|
317
|
*/
|
| mbed714 |
0:d616ece2d859
|
318
|
if (IPH_LEN(ip) != IPH_LEN(&cs->cs_ip) &&
|
| mbed714 |
0:d616ece2d859
|
319
|
ntohs(IPH_LEN(&cs->cs_ip)) == hlen) {
|
| mbed714 |
0:d616ece2d859
|
320
|
break;
|
| mbed714 |
0:d616ece2d859
|
321
|
}
|
| mbed714 |
0:d616ece2d859
|
322
|
|
| mbed714 |
0:d616ece2d859
|
323
|
/* (fall through) */
|
| mbed714 |
0:d616ece2d859
|
324
|
|
| mbed714 |
0:d616ece2d859
|
325
|
case SPECIAL_I:
|
| mbed714 |
0:d616ece2d859
|
326
|
case SPECIAL_D:
|
| mbed714 |
0:d616ece2d859
|
327
|
/*
|
| mbed714 |
0:d616ece2d859
|
328
|
* actual changes match one of our special case encodings --
|
| mbed714 |
0:d616ece2d859
|
329
|
* send packet uncompressed.
|
| mbed714 |
0:d616ece2d859
|
330
|
*/
|
| mbed714 |
0:d616ece2d859
|
331
|
goto uncompressed;
|
| mbed714 |
0:d616ece2d859
|
332
|
|
| mbed714 |
0:d616ece2d859
|
333
|
case NEW_S|NEW_A:
|
| mbed714 |
0:d616ece2d859
|
334
|
if (deltaS == deltaA && deltaS == ntohs(IPH_LEN(&cs->cs_ip)) - hlen) {
|
| mbed714 |
0:d616ece2d859
|
335
|
/* special case for echoed terminal traffic */
|
| mbed714 |
0:d616ece2d859
|
336
|
changes = SPECIAL_I;
|
| mbed714 |
0:d616ece2d859
|
337
|
cp = new_seq;
|
| mbed714 |
0:d616ece2d859
|
338
|
}
|
| mbed714 |
0:d616ece2d859
|
339
|
break;
|
| mbed714 |
0:d616ece2d859
|
340
|
|
| mbed714 |
0:d616ece2d859
|
341
|
case NEW_S:
|
| mbed714 |
0:d616ece2d859
|
342
|
if (deltaS == ntohs(IPH_LEN(&cs->cs_ip)) - hlen) {
|
| mbed714 |
0:d616ece2d859
|
343
|
/* special case for data xfer */
|
| mbed714 |
0:d616ece2d859
|
344
|
changes = SPECIAL_D;
|
| mbed714 |
0:d616ece2d859
|
345
|
cp = new_seq;
|
| mbed714 |
0:d616ece2d859
|
346
|
}
|
| mbed714 |
0:d616ece2d859
|
347
|
break;
|
| mbed714 |
0:d616ece2d859
|
348
|
}
|
| mbed714 |
0:d616ece2d859
|
349
|
|
| mbed714 |
0:d616ece2d859
|
350
|
deltaS = (u_short)(ntohs(IPH_ID(ip)) - ntohs(IPH_ID(&cs->cs_ip)));
|
| mbed714 |
0:d616ece2d859
|
351
|
if (deltaS != 1) {
|
| mbed714 |
0:d616ece2d859
|
352
|
ENCODEZ(deltaS);
|
| mbed714 |
0:d616ece2d859
|
353
|
changes |= NEW_I;
|
| mbed714 |
0:d616ece2d859
|
354
|
}
|
| mbed714 |
0:d616ece2d859
|
355
|
if (TCPH_FLAGS(th) & TCP_PSH) {
|
| mbed714 |
0:d616ece2d859
|
356
|
changes |= TCP_PUSH_BIT;
|
| mbed714 |
0:d616ece2d859
|
357
|
}
|
| mbed714 |
0:d616ece2d859
|
358
|
/*
|
| mbed714 |
0:d616ece2d859
|
359
|
* Grab the cksum before we overwrite it below. Then update our
|
| mbed714 |
0:d616ece2d859
|
360
|
* state with this packet's header.
|
| mbed714 |
0:d616ece2d859
|
361
|
*/
|
| mbed714 |
0:d616ece2d859
|
362
|
deltaA = ntohs(th->chksum);
|
| mbed714 |
0:d616ece2d859
|
363
|
BCOPY(ip, &cs->cs_ip, hlen);
|
| mbed714 |
0:d616ece2d859
|
364
|
|
| mbed714 |
0:d616ece2d859
|
365
|
/*
|
| mbed714 |
0:d616ece2d859
|
366
|
* We want to use the original packet as our compressed packet.
|
| mbed714 |
0:d616ece2d859
|
367
|
* (cp - new_seq) is the number of bytes we need for compressed
|
| mbed714 |
0:d616ece2d859
|
368
|
* sequence numbers. In addition we need one byte for the change
|
| mbed714 |
0:d616ece2d859
|
369
|
* mask, one for the connection id and two for the tcp checksum.
|
| mbed714 |
0:d616ece2d859
|
370
|
* So, (cp - new_seq) + 4 bytes of header are needed. hlen is how
|
| mbed714 |
0:d616ece2d859
|
371
|
* many bytes of the original packet to toss so subtract the two to
|
| mbed714 |
0:d616ece2d859
|
372
|
* get the new packet size.
|
| mbed714 |
0:d616ece2d859
|
373
|
*/
|
| mbed714 |
0:d616ece2d859
|
374
|
deltaS = (u_short)(cp - new_seq);
|
| mbed714 |
0:d616ece2d859
|
375
|
if (!comp->compressSlot || comp->last_xmit != cs->cs_id) {
|
| mbed714 |
0:d616ece2d859
|
376
|
comp->last_xmit = cs->cs_id;
|
| mbed714 |
0:d616ece2d859
|
377
|
hlen -= deltaS + 4;
|
| mbed714 |
0:d616ece2d859
|
378
|
if(pbuf_header(pb, -hlen)){
|
| mbed714 |
0:d616ece2d859
|
379
|
/* Can we cope with this failing? Just assert for now */
|
| mbed714 |
0:d616ece2d859
|
380
|
LWIP_ASSERT("pbuf_header failed\n", 0);
|
| mbed714 |
0:d616ece2d859
|
381
|
}
|
| mbed714 |
0:d616ece2d859
|
382
|
cp = (u_char *)pb->payload;
|
| mbed714 |
0:d616ece2d859
|
383
|
*cp++ = (u_char)(changes | NEW_C);
|
| mbed714 |
0:d616ece2d859
|
384
|
*cp++ = cs->cs_id;
|
| mbed714 |
0:d616ece2d859
|
385
|
} else {
|
| mbed714 |
0:d616ece2d859
|
386
|
hlen -= deltaS + 3;
|
| mbed714 |
0:d616ece2d859
|
387
|
if(pbuf_header(pb, -hlen)) {
|
| mbed714 |
0:d616ece2d859
|
388
|
/* Can we cope with this failing? Just assert for now */
|
| mbed714 |
0:d616ece2d859
|
389
|
LWIP_ASSERT("pbuf_header failed\n", 0);
|
| mbed714 |
0:d616ece2d859
|
390
|
}
|
| mbed714 |
0:d616ece2d859
|
391
|
cp = (u_char *)pb->payload;
|
| mbed714 |
0:d616ece2d859
|
392
|
*cp++ = (u_char)changes;
|
| mbed714 |
0:d616ece2d859
|
393
|
}
|
| mbed714 |
0:d616ece2d859
|
394
|
*cp++ = (u_char)(deltaA >> 8);
|
| mbed714 |
0:d616ece2d859
|
395
|
*cp++ = (u_char)deltaA;
|
| mbed714 |
0:d616ece2d859
|
396
|
BCOPY(new_seq, cp, deltaS);
|
| mbed714 |
0:d616ece2d859
|
397
|
INCR(vjs_compressed);
|
| mbed714 |
0:d616ece2d859
|
398
|
return (TYPE_COMPRESSED_TCP);
|
| mbed714 |
0:d616ece2d859
|
399
|
|
| mbed714 |
0:d616ece2d859
|
400
|
/*
|
| mbed714 |
0:d616ece2d859
|
401
|
* Update connection state cs & send uncompressed packet (that is,
|
| mbed714 |
0:d616ece2d859
|
402
|
* a regular ip/tcp packet but with the 'conversation id' we hope
|
| mbed714 |
0:d616ece2d859
|
403
|
* to use on future compressed packets in the protocol field).
|
| mbed714 |
0:d616ece2d859
|
404
|
*/
|
| mbed714 |
0:d616ece2d859
|
405
|
uncompressed:
|
| mbed714 |
0:d616ece2d859
|
406
|
BCOPY(ip, &cs->cs_ip, hlen);
|
| mbed714 |
0:d616ece2d859
|
407
|
IPH_PROTO_SET(ip, cs->cs_id);
|
| mbed714 |
0:d616ece2d859
|
408
|
comp->last_xmit = cs->cs_id;
|
| mbed714 |
0:d616ece2d859
|
409
|
return (TYPE_UNCOMPRESSED_TCP);
|
| mbed714 |
0:d616ece2d859
|
410
|
}
|
| mbed714 |
0:d616ece2d859
|
411
|
|
| mbed714 |
0:d616ece2d859
|
412
|
/*
|
| mbed714 |
0:d616ece2d859
|
413
|
* Called when we may have missed a packet.
|
| mbed714 |
0:d616ece2d859
|
414
|
*/
|
| mbed714 |
0:d616ece2d859
|
415
|
void
|
| mbed714 |
0:d616ece2d859
|
416
|
vj_uncompress_err(struct vjcompress *comp)
|
| mbed714 |
0:d616ece2d859
|
417
|
{
|
| mbed714 |
0:d616ece2d859
|
418
|
comp->flags |= VJF_TOSS;
|
| mbed714 |
0:d616ece2d859
|
419
|
INCR(vjs_errorin);
|
| mbed714 |
0:d616ece2d859
|
420
|
}
|
| mbed714 |
0:d616ece2d859
|
421
|
|
| mbed714 |
0:d616ece2d859
|
422
|
/*
|
| mbed714 |
0:d616ece2d859
|
423
|
* "Uncompress" a packet of type TYPE_UNCOMPRESSED_TCP.
|
| mbed714 |
0:d616ece2d859
|
424
|
* Return 0 on success, -1 on failure.
|
| mbed714 |
0:d616ece2d859
|
425
|
*/
|
| mbed714 |
0:d616ece2d859
|
426
|
int
|
| mbed714 |
0:d616ece2d859
|
427
|
vj_uncompress_uncomp(struct pbuf *nb, struct vjcompress *comp)
|
| mbed714 |
0:d616ece2d859
|
428
|
{
|
| mbed714 |
0:d616ece2d859
|
429
|
register u_int hlen;
|
| mbed714 |
0:d616ece2d859
|
430
|
register struct cstate *cs;
|
| mbed714 |
0:d616ece2d859
|
431
|
register struct ip_hdr *ip;
|
| mbed714 |
0:d616ece2d859
|
432
|
|
| mbed714 |
0:d616ece2d859
|
433
|
ip = (struct ip_hdr *)nb->payload;
|
| mbed714 |
0:d616ece2d859
|
434
|
hlen = IPH_HL(ip) << 2;
|
| mbed714 |
0:d616ece2d859
|
435
|
if (IPH_PROTO(ip) >= MAX_SLOTS
|
| mbed714 |
0:d616ece2d859
|
436
|
|| hlen + sizeof(struct tcp_hdr) > nb->len
|
| mbed714 |
0:d616ece2d859
|
437
|
|| (hlen += TCPH_OFFSET(((struct tcp_hdr *)&((char *)ip)[hlen])) << 2)
|
| mbed714 |
0:d616ece2d859
|
438
|
> nb->len
|
| mbed714 |
0:d616ece2d859
|
439
|
|| hlen > MAX_HDR) {
|
| mbed714 |
0:d616ece2d859
|
440
|
PPPDEBUG(LOG_INFO, ("vj_uncompress_uncomp: bad cid=%d, hlen=%d buflen=%d\n",
|
| mbed714 |
0:d616ece2d859
|
441
|
IPH_PROTO(ip), hlen, nb->len));
|
| mbed714 |
0:d616ece2d859
|
442
|
comp->flags |= VJF_TOSS;
|
| mbed714 |
0:d616ece2d859
|
443
|
INCR(vjs_errorin);
|
| mbed714 |
0:d616ece2d859
|
444
|
return -1;
|
| mbed714 |
0:d616ece2d859
|
445
|
}
|
| mbed714 |
0:d616ece2d859
|
446
|
cs = &comp->rstate[comp->last_recv = IPH_PROTO(ip)];
|
| mbed714 |
0:d616ece2d859
|
447
|
comp->flags &=~ VJF_TOSS;
|
| mbed714 |
0:d616ece2d859
|
448
|
IPH_PROTO_SET(ip, IP_PROTO_TCP);
|
| mbed714 |
0:d616ece2d859
|
449
|
BCOPY(ip, &cs->cs_ip, hlen);
|
| mbed714 |
0:d616ece2d859
|
450
|
cs->cs_hlen = (u_short)hlen;
|
| mbed714 |
0:d616ece2d859
|
451
|
INCR(vjs_uncompressedin);
|
| mbed714 |
0:d616ece2d859
|
452
|
return 0;
|
| mbed714 |
0:d616ece2d859
|
453
|
}
|
| mbed714 |
0:d616ece2d859
|
454
|
|
| mbed714 |
0:d616ece2d859
|
455
|
/*
|
| mbed714 |
0:d616ece2d859
|
456
|
* Uncompress a packet of type TYPE_COMPRESSED_TCP.
|
| mbed714 |
0:d616ece2d859
|
457
|
* The packet is composed of a buffer chain and the first buffer
|
| mbed714 |
0:d616ece2d859
|
458
|
* must contain an accurate chain length.
|
| mbed714 |
0:d616ece2d859
|
459
|
* The first buffer must include the entire compressed TCP/IP header.
|
| mbed714 |
0:d616ece2d859
|
460
|
* This procedure replaces the compressed header with the uncompressed
|
| mbed714 |
0:d616ece2d859
|
461
|
* header and returns the length of the VJ header.
|
| mbed714 |
0:d616ece2d859
|
462
|
*/
|
| mbed714 |
0:d616ece2d859
|
463
|
int
|
| mbed714 |
0:d616ece2d859
|
464
|
vj_uncompress_tcp(struct pbuf **nb, struct vjcompress *comp)
|
| mbed714 |
0:d616ece2d859
|
465
|
{
|
| mbed714 |
0:d616ece2d859
|
466
|
u_char *cp;
|
| mbed714 |
0:d616ece2d859
|
467
|
struct tcp_hdr *th;
|
| mbed714 |
0:d616ece2d859
|
468
|
struct cstate *cs;
|
| mbed714 |
0:d616ece2d859
|
469
|
u_short *bp;
|
| mbed714 |
0:d616ece2d859
|
470
|
struct pbuf *n0 = *nb;
|
| mbed714 |
0:d616ece2d859
|
471
|
u32_t tmp;
|
| mbed714 |
0:d616ece2d859
|
472
|
u_int vjlen, hlen, changes;
|
| mbed714 |
0:d616ece2d859
|
473
|
|
| mbed714 |
0:d616ece2d859
|
474
|
INCR(vjs_compressedin);
|
| mbed714 |
0:d616ece2d859
|
475
|
cp = (u_char *)n0->payload;
|
| mbed714 |
0:d616ece2d859
|
476
|
changes = *cp++;
|
| mbed714 |
0:d616ece2d859
|
477
|
if (changes & NEW_C) {
|
| mbed714 |
0:d616ece2d859
|
478
|
/*
|
| mbed714 |
0:d616ece2d859
|
479
|
* Make sure the state index is in range, then grab the state.
|
| mbed714 |
0:d616ece2d859
|
480
|
* If we have a good state index, clear the 'discard' flag.
|
| mbed714 |
0:d616ece2d859
|
481
|
*/
|
| mbed714 |
0:d616ece2d859
|
482
|
if (*cp >= MAX_SLOTS) {
|
| mbed714 |
0:d616ece2d859
|
483
|
PPPDEBUG(LOG_INFO, ("vj_uncompress_tcp: bad cid=%d\n", *cp));
|
| mbed714 |
0:d616ece2d859
|
484
|
goto bad;
|
| mbed714 |
0:d616ece2d859
|
485
|
}
|
| mbed714 |
0:d616ece2d859
|
486
|
|
| mbed714 |
0:d616ece2d859
|
487
|
comp->flags &=~ VJF_TOSS;
|
| mbed714 |
0:d616ece2d859
|
488
|
comp->last_recv = *cp++;
|
| mbed714 |
0:d616ece2d859
|
489
|
} else {
|
| mbed714 |
0:d616ece2d859
|
490
|
/*
|
| mbed714 |
0:d616ece2d859
|
491
|
* this packet has an implicit state index. If we've
|
| mbed714 |
0:d616ece2d859
|
492
|
* had a line error since the last time we got an
|
| mbed714 |
0:d616ece2d859
|
493
|
* explicit state index, we have to toss the packet.
|
| mbed714 |
0:d616ece2d859
|
494
|
*/
|
| mbed714 |
0:d616ece2d859
|
495
|
if (comp->flags & VJF_TOSS) {
|
| mbed714 |
0:d616ece2d859
|
496
|
PPPDEBUG(LOG_INFO, ("vj_uncompress_tcp: tossing\n"));
|
| mbed714 |
0:d616ece2d859
|
497
|
INCR(vjs_tossed);
|
| mbed714 |
0:d616ece2d859
|
498
|
return (-1);
|
| mbed714 |
0:d616ece2d859
|
499
|
}
|
| mbed714 |
0:d616ece2d859
|
500
|
}
|
| mbed714 |
0:d616ece2d859
|
501
|
cs = &comp->rstate[comp->last_recv];
|
| mbed714 |
0:d616ece2d859
|
502
|
hlen = IPH_HL(&cs->cs_ip) << 2;
|
| mbed714 |
0:d616ece2d859
|
503
|
th = (struct tcp_hdr *)&((u_char *)&cs->cs_ip)[hlen];
|
| mbed714 |
0:d616ece2d859
|
504
|
th->chksum = htons((*cp << 8) | cp[1]);
|
| mbed714 |
0:d616ece2d859
|
505
|
cp += 2;
|
| mbed714 |
0:d616ece2d859
|
506
|
if (changes & TCP_PUSH_BIT) {
|
| mbed714 |
0:d616ece2d859
|
507
|
TCPH_SET_FLAG(th, TCP_PSH);
|
| mbed714 |
0:d616ece2d859
|
508
|
} else {
|
| mbed714 |
0:d616ece2d859
|
509
|
TCPH_UNSET_FLAG(th, TCP_PSH);
|
| mbed714 |
0:d616ece2d859
|
510
|
}
|
| mbed714 |
0:d616ece2d859
|
511
|
|
| mbed714 |
0:d616ece2d859
|
512
|
switch (changes & SPECIALS_MASK) {
|
| mbed714 |
0:d616ece2d859
|
513
|
case SPECIAL_I:
|
| mbed714 |
0:d616ece2d859
|
514
|
{
|
| mbed714 |
0:d616ece2d859
|
515
|
register u32_t i = ntohs(IPH_LEN(&cs->cs_ip)) - cs->cs_hlen;
|
| mbed714 |
0:d616ece2d859
|
516
|
/* some compilers can't nest inline assembler.. */
|
| mbed714 |
0:d616ece2d859
|
517
|
tmp = ntohl(th->ackno) + i;
|
| mbed714 |
0:d616ece2d859
|
518
|
th->ackno = htonl(tmp);
|
| mbed714 |
0:d616ece2d859
|
519
|
tmp = ntohl(th->seqno) + i;
|
| mbed714 |
0:d616ece2d859
|
520
|
th->seqno = htonl(tmp);
|
| mbed714 |
0:d616ece2d859
|
521
|
}
|
| mbed714 |
0:d616ece2d859
|
522
|
break;
|
| mbed714 |
0:d616ece2d859
|
523
|
|
| mbed714 |
0:d616ece2d859
|
524
|
case SPECIAL_D:
|
| mbed714 |
0:d616ece2d859
|
525
|
/* some compilers can't nest inline assembler.. */
|
| mbed714 |
0:d616ece2d859
|
526
|
tmp = ntohl(th->seqno) + ntohs(IPH_LEN(&cs->cs_ip)) - cs->cs_hlen;
|
| mbed714 |
0:d616ece2d859
|
527
|
th->seqno = htonl(tmp);
|
| mbed714 |
0:d616ece2d859
|
528
|
break;
|
| mbed714 |
0:d616ece2d859
|
529
|
|
| mbed714 |
0:d616ece2d859
|
530
|
default:
|
| mbed714 |
0:d616ece2d859
|
531
|
if (changes & NEW_U) {
|
| mbed714 |
0:d616ece2d859
|
532
|
TCPH_SET_FLAG(th, TCP_URG);
|
| mbed714 |
0:d616ece2d859
|
533
|
DECODEU(th->urgp);
|
| mbed714 |
0:d616ece2d859
|
534
|
} else {
|
| mbed714 |
0:d616ece2d859
|
535
|
TCPH_UNSET_FLAG(th, TCP_URG);
|
| mbed714 |
0:d616ece2d859
|
536
|
}
|
| mbed714 |
0:d616ece2d859
|
537
|
if (changes & NEW_W) {
|
| mbed714 |
0:d616ece2d859
|
538
|
DECODES(th->wnd);
|
| mbed714 |
0:d616ece2d859
|
539
|
}
|
| mbed714 |
0:d616ece2d859
|
540
|
if (changes & NEW_A) {
|
| mbed714 |
0:d616ece2d859
|
541
|
DECODEL(th->ackno);
|
| mbed714 |
0:d616ece2d859
|
542
|
}
|
| mbed714 |
0:d616ece2d859
|
543
|
if (changes & NEW_S) {
|
| mbed714 |
0:d616ece2d859
|
544
|
DECODEL(th->seqno);
|
| mbed714 |
0:d616ece2d859
|
545
|
}
|
| mbed714 |
0:d616ece2d859
|
546
|
break;
|
| mbed714 |
0:d616ece2d859
|
547
|
}
|
| mbed714 |
0:d616ece2d859
|
548
|
if (changes & NEW_I) {
|
| mbed714 |
0:d616ece2d859
|
549
|
DECODES(cs->cs_ip._id);
|
| mbed714 |
0:d616ece2d859
|
550
|
} else {
|
| mbed714 |
0:d616ece2d859
|
551
|
IPH_ID_SET(&cs->cs_ip, ntohs(IPH_ID(&cs->cs_ip)) + 1);
|
| mbed714 |
0:d616ece2d859
|
552
|
IPH_ID_SET(&cs->cs_ip, htons(IPH_ID(&cs->cs_ip)));
|
| mbed714 |
0:d616ece2d859
|
553
|
}
|
| mbed714 |
0:d616ece2d859
|
554
|
|
| mbed714 |
0:d616ece2d859
|
555
|
/*
|
| mbed714 |
0:d616ece2d859
|
556
|
* At this point, cp points to the first byte of data in the
|
| mbed714 |
0:d616ece2d859
|
557
|
* packet. Fill in the IP total length and update the IP
|
| mbed714 |
0:d616ece2d859
|
558
|
* header checksum.
|
| mbed714 |
0:d616ece2d859
|
559
|
*/
|
| mbed714 |
0:d616ece2d859
|
560
|
vjlen = (u_short)(cp - (u_char*)n0->payload);
|
| mbed714 |
0:d616ece2d859
|
561
|
if (n0->len < vjlen) {
|
| mbed714 |
0:d616ece2d859
|
562
|
/*
|
| mbed714 |
0:d616ece2d859
|
563
|
* We must have dropped some characters (crc should detect
|
| mbed714 |
0:d616ece2d859
|
564
|
* this but the old slip framing won't)
|
| mbed714 |
0:d616ece2d859
|
565
|
*/
|
| mbed714 |
0:d616ece2d859
|
566
|
PPPDEBUG(LOG_INFO, ("vj_uncompress_tcp: head buffer %d too short %d\n",
|
| mbed714 |
0:d616ece2d859
|
567
|
n0->len, vjlen));
|
| mbed714 |
0:d616ece2d859
|
568
|
goto bad;
|
| mbed714 |
0:d616ece2d859
|
569
|
}
|
| mbed714 |
0:d616ece2d859
|
570
|
|
| mbed714 |
0:d616ece2d859
|
571
|
#if BYTE_ORDER == LITTLE_ENDIAN
|
| mbed714 |
0:d616ece2d859
|
572
|
tmp = n0->tot_len - vjlen + cs->cs_hlen;
|
| mbed714 |
0:d616ece2d859
|
573
|
IPH_LEN_SET(&cs->cs_ip, htons((u_short)tmp));
|
| mbed714 |
0:d616ece2d859
|
574
|
#else
|
| mbed714 |
0:d616ece2d859
|
575
|
IPH_LEN_SET(&cs->cs_ip, htons(n0->tot_len - vjlen + cs->cs_hlen));
|
| mbed714 |
0:d616ece2d859
|
576
|
#endif
|
| mbed714 |
0:d616ece2d859
|
577
|
|
| mbed714 |
0:d616ece2d859
|
578
|
/* recompute the ip header checksum */
|
| mbed714 |
0:d616ece2d859
|
579
|
bp = (u_short *) &cs->cs_ip;
|
| mbed714 |
0:d616ece2d859
|
580
|
IPH_CHKSUM_SET(&cs->cs_ip, 0);
|
| mbed714 |
0:d616ece2d859
|
581
|
for (tmp = 0; hlen > 0; hlen -= 2) {
|
| mbed714 |
0:d616ece2d859
|
582
|
tmp += *bp++;
|
| mbed714 |
0:d616ece2d859
|
583
|
}
|
| mbed714 |
0:d616ece2d859
|
584
|
tmp = (tmp & 0xffff) + (tmp >> 16);
|
| mbed714 |
0:d616ece2d859
|
585
|
tmp = (tmp & 0xffff) + (tmp >> 16);
|
| mbed714 |
0:d616ece2d859
|
586
|
IPH_CHKSUM_SET(&cs->cs_ip, (u_short)(~tmp));
|
| mbed714 |
0:d616ece2d859
|
587
|
|
| mbed714 |
0:d616ece2d859
|
588
|
/* Remove the compressed header and prepend the uncompressed header. */
|
| mbed714 |
0:d616ece2d859
|
589
|
if(pbuf_header(n0, -((s16_t)(vjlen)))) {
|
| mbed714 |
0:d616ece2d859
|
590
|
/* Can we cope with this failing? Just assert for now */
|
| mbed714 |
0:d616ece2d859
|
591
|
LWIP_ASSERT("pbuf_header failed\n", 0);
|
| mbed714 |
0:d616ece2d859
|
592
|
goto bad;
|
| mbed714 |
0:d616ece2d859
|
593
|
}
|
| mbed714 |
0:d616ece2d859
|
594
|
|
| mbed714 |
0:d616ece2d859
|
595
|
if(LWIP_MEM_ALIGN(n0->payload) != n0->payload) {
|
| mbed714 |
0:d616ece2d859
|
596
|
struct pbuf *np, *q;
|
| mbed714 |
0:d616ece2d859
|
597
|
u8_t *bufptr;
|
| mbed714 |
0:d616ece2d859
|
598
|
|
| mbed714 |
0:d616ece2d859
|
599
|
np = pbuf_alloc(PBUF_RAW, n0->len + cs->cs_hlen, PBUF_POOL);
|
| mbed714 |
0:d616ece2d859
|
600
|
if(!np) {
|
| mbed714 |
0:d616ece2d859
|
601
|
PPPDEBUG(LOG_WARNING, ("vj_uncompress_tcp: realign failed\n"));
|
| mbed714 |
0:d616ece2d859
|
602
|
goto bad;
|
| mbed714 |
0:d616ece2d859
|
603
|
}
|
| mbed714 |
0:d616ece2d859
|
604
|
|
| mbed714 |
0:d616ece2d859
|
605
|
if(pbuf_header(np, -cs->cs_hlen)) {
|
| mbed714 |
0:d616ece2d859
|
606
|
/* Can we cope with this failing? Just assert for now */
|
| mbed714 |
0:d616ece2d859
|
607
|
LWIP_ASSERT("pbuf_header failed\n", 0);
|
| mbed714 |
0:d616ece2d859
|
608
|
goto bad;
|
| mbed714 |
0:d616ece2d859
|
609
|
}
|
| mbed714 |
0:d616ece2d859
|
610
|
|
| mbed714 |
0:d616ece2d859
|
611
|
bufptr = (u8_t *)n0->payload;
|
| mbed714 |
0:d616ece2d859
|
612
|
for(q = np; q != NULL; q = q->next) {
|
| mbed714 |
0:d616ece2d859
|
613
|
MEMCPY(q->payload, bufptr, q->len);
|
| mbed714 |
0:d616ece2d859
|
614
|
bufptr += q->len;
|
| mbed714 |
0:d616ece2d859
|
615
|
}
|
| mbed714 |
0:d616ece2d859
|
616
|
|
| mbed714 |
0:d616ece2d859
|
617
|
if(n0->next) {
|
| mbed714 |
0:d616ece2d859
|
618
|
pbuf_chain(np, n0->next);
|
| mbed714 |
0:d616ece2d859
|
619
|
pbuf_dechain(n0);
|
| mbed714 |
0:d616ece2d859
|
620
|
}
|
| mbed714 |
0:d616ece2d859
|
621
|
pbuf_free(n0);
|
| mbed714 |
0:d616ece2d859
|
622
|
n0 = np;
|
| mbed714 |
0:d616ece2d859
|
623
|
}
|
| mbed714 |
0:d616ece2d859
|
624
|
|
| mbed714 |
0:d616ece2d859
|
625
|
if(pbuf_header(n0, cs->cs_hlen)) {
|
| mbed714 |
0:d616ece2d859
|
626
|
struct pbuf *np;
|
| mbed714 |
0:d616ece2d859
|
627
|
|
| mbed714 |
0:d616ece2d859
|
628
|
LWIP_ASSERT("vj_uncompress_tcp: cs->cs_hlen <= PBUF_POOL_BUFSIZE", cs->cs_hlen <= PBUF_POOL_BUFSIZE);
|
| mbed714 |
0:d616ece2d859
|
629
|
np = pbuf_alloc(PBUF_RAW, cs->cs_hlen, PBUF_POOL);
|
| mbed714 |
0:d616ece2d859
|
630
|
if(!np) {
|
| mbed714 |
0:d616ece2d859
|
631
|
PPPDEBUG(LOG_WARNING, ("vj_uncompress_tcp: prepend failed\n"));
|
| mbed714 |
0:d616ece2d859
|
632
|
goto bad;
|
| mbed714 |
0:d616ece2d859
|
633
|
}
|
| mbed714 |
0:d616ece2d859
|
634
|
pbuf_cat(np, n0);
|
| mbed714 |
0:d616ece2d859
|
635
|
n0 = np;
|
| mbed714 |
0:d616ece2d859
|
636
|
}
|
| mbed714 |
0:d616ece2d859
|
637
|
LWIP_ASSERT("n0->len >= cs->cs_hlen", n0->len >= cs->cs_hlen);
|
| mbed714 |
0:d616ece2d859
|
638
|
MEMCPY(n0->payload, &cs->cs_ip, cs->cs_hlen);
|
| mbed714 |
0:d616ece2d859
|
639
|
|
| mbed714 |
0:d616ece2d859
|
640
|
*nb = n0;
|
| mbed714 |
0:d616ece2d859
|
641
|
|
| mbed714 |
0:d616ece2d859
|
642
|
return vjlen;
|
| mbed714 |
0:d616ece2d859
|
643
|
|
| mbed714 |
0:d616ece2d859
|
644
|
bad:
|
| mbed714 |
0:d616ece2d859
|
645
|
comp->flags |= VJF_TOSS;
|
| mbed714 |
0:d616ece2d859
|
646
|
INCR(vjs_errorin);
|
| mbed714 |
0:d616ece2d859
|
647
|
return (-1);
|
| mbed714 |
0:d616ece2d859
|
648
|
}
|
| mbed714 |
0:d616ece2d859
|
649
|
|
| mbed714 |
0:d616ece2d859
|
650
|
#endif /* VJ_SUPPORT */
|
| mbed714 |
0:d616ece2d859
|
651
|
|
| mbed714 |
0:d616ece2d859
|
652
|
#endif /* PPP_SUPPORT */
|
Daniel Peter