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fix the cksum routine and parse ESH packets.

This commit is contained in:
chopps 1999-04-05 00:58:29 +00:00
parent 0f2eecb8c3
commit 1b017ba3a8
1 changed files with 44 additions and 26 deletions
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70
usr.sbin/tcpdump/print-isoclns.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: print-isoclns.c,v 1.4 1997/10/03 19:55:21 christos Exp $ */
/* $NetBSD: print-isoclns.c,v 1.5 1999/04/05 00:58:29 chopps Exp $ */
/*
* Copyright (c) 1992, 1993, 1994, 1995, 1996
@ -29,7 +29,7 @@
static const char rcsid[] =
"@(#) Header: print-isoclns.c,v 1.15 96/12/31 21:27:41 leres Exp (LBL)";
#else
__RCSID("$NetBSD: print-isoclns.c,v 1.4 1997/10/03 19:55:21 christos Exp $");
__RCSID("$NetBSD: print-isoclns.c,v 1.5 1999/04/05 00:58:29 chopps Exp $");
#endif
#endif
@ -231,11 +231,27 @@ esis_print(const u_char *p, u_int length)
li = ep - p;
break;
}
#if 0
case ESIS_ESH:
printf(" esh");
case ESIS_ESH: {
const u_char *nsap;
int i, nnsaps;
nnsaps = *p++;
/* print NSAPs */
for (i = 0; i < nnsaps; i++) {
nsap = p;
p += *p + 1;
if (p > ep) {
printf(" [bad li]");
return;
}
if (p > snapend)
return;
printf(" nsap %s", isonsap_string(nsap));
}
li = ep - p;
break;
#endif
}
case ESIS_ISH: {
const u_char *is;
@ -246,7 +262,7 @@ esis_print(const u_char *p, u_int length)
}
if (p > snapend)
return;
printf(" %s", isonsap_string(is));
printf(" net %s", isonsap_string(is));
li = ep - p;
break;
}
@ -297,32 +313,34 @@ static int
osi_cksum(register const u_char *p, register u_int len,
const u_char *toff, u_char *cksum, u_char *off)
{
int x, y, f = (len - ((toff - p) + 1));
int32_t c0 = 0, c1 = 0;
const u_char *ep;
int c0, c1;
int n;
if ((cksum[0] = off[0]) == 0 && (cksum[1] = off[1]) == 0)
return 0;
off[0] = off[1] = 0;
while ((int)--len >= 0) {
c0 += *p++;
n = toff - p + 1;
c0 = c1 = 0;
ep = p + len;
for (; p < toff; p++) {
c0 = (c0 + *p);
c1 += c0;
c0 %= 255;
c1 %= 255;
}
x = (c0 * f - c1);
if (x < 0)
x = 255 - (-x % 255);
else
x %= 255;
y = -1 * (x + c0);
if (y < 0)
y = 255 - (-y % 255);
else
y %= 255;
off[0] = x;
off[1] = y;
/* skip cksum bytes */
p += 2;
c1 += c0; c1 += c0;
for (; p < ep; p++) {
c0 = (c0 + *p);
c1 += c0;
}
c1 = (((c0 * (len - n)) - c1) % 255);
cksum[0] = (u_char) ((c1 < 0) ? c1 + 255 : c1);
c1 = (-(int) (c1 + c0)) % 255;
cksum[1] = (u_char) (c1 < 0 ? c1 + 255 : c1);
return (off[0] != cksum[0] || off[1] != cksum[1]);
}