mirrors/tcpdump
0
0
Fork 0
mirror of https://github.com/the-tcpdump-group/tcpdump.git synced 2024-11-28 04:25:16 +08:00
Code Issues Packages Projects Releases Wiki Activity

from Darren Reed <darrenr@reed.wattle.id.au>:

Browse Source 
support for HDLC inside PPP
This commit is contained in:
hannes 2004-07-02 20:17:47 +00:00
parent dcf2763947
commit af73cfb14d
1 changed files with 74 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

75
print-ppp.c
View File

@ -31,7 +31,7 @@
#ifndef lint
static const char rcsid[] _U_ =
"@(#) $Header: /tcpdump/master/tcpdump/print-ppp.c,v 1.95 2004-07-02 06:32:47 hannes Exp $ (LBL)";
"@(#) $Header: /tcpdump/master/tcpdump/print-ppp.c,v 1.96 2004-07-02 20:17:47 hannes Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
@ -47,6 +47,7 @@ static const char rcsid[] _U_ =
#include <pcap.h>
#include <stdio.h>
#include <stdlib.h>
#include "interface.h"
#include "extract.h"
@ -370,6 +371,7 @@ static int print_ipcp_config_options (const u_char *p, int);
static int print_ccp_config_options (const u_char *p, int);
static int print_bacp_config_options (const u_char *p, int);
static void handle_ppp (u_int proto, const u_char *p, int length);
static void ppp_hdlc(const u_char *p, int length);
/* generic Control Protocol (e.g. LCP, IPCP, CCP, etc.) handler */
static void
@ -1052,10 +1054,81 @@ trunc:
}
static void
ppp_hdlc(const u_char *p, int length)
{
u_char *b, *s, *t, c;
int i, proto;
const void *se;
b = (u_int8_t *)malloc(length);
if (b == NULL)
return;
/*
* Unescape all the data into a temporary, private, buffer.
* Do this so that we dont overwrite the original packet
* contents.
*/
for (s = (u_char *)p, t = b, i = length; i > 0; i--) {
c = *s++;
if (c == 0x7d) {
if (i > 1) {
i--;
c = *s++ ^ 0x20;
} else
continue;
}
*t++ = c;
}
se = snapend;
snapend = t;
/* now lets guess about the payload codepoint format */
proto = *b; /* start with a one-octet codepoint guess */
switch (proto) {
case PPP_IP:
ip_print(b+1, t - b - 1);
goto cleanup;
#ifdef INET6
case PPP_IPV6:
ip6_print(b+1, t - b - 1);
goto cleanup;
#endif
default: /* no luck - try next guess */
break;
}
proto = EXTRACT_16BITS(b); /* next guess - load two octets */
switch (proto) {
case 0xff03: /* looks like a PPP frame */
proto = EXTRACT_16BITS(b+2); /* load the PPP proto-id */
handle_ppp(proto, b+4, t - b - 4);
break;
default: /* last guess - proto must be a PPP proto-id */
handle_ppp(proto, b+2, t - b - 2);
break;
}
cleanup:
snapend = se;
free(b);
return;
}
/* PPP */
static void
handle_ppp(u_int proto, const u_char *p, int length)
{
if ((proto & 0xff00) == 0x7e00) {/* is this an escape code ? */
ppp_hdlc(p-1, length);
return;
}
switch (proto) {
case PPP_LCP:
case PPP_IPCP: