*/
-#ifndef lint
-static const char rcsid[] =
- "@(#) $Header: /tcpdump/master/tcpdump/print-l2tp.c,v 1.12 2002-06-11 17:08:51 itojun Exp $";
-#endif
-
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
+#include <tcpdump-stdinc.h>
+
#include <stdio.h>
-#include <sys/types.h>
-#include <sys/param.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-#include "l2tp.h"
#include "interface.h"
#include "extract.h"
-static char tstr[] = " [|l2tp]";
+#define L2TP_FLAG_TYPE 0x8000 /* Type (0=Data, 1=Control) */
+#define L2TP_FLAG_LENGTH 0x4000 /* Length */
+#define L2TP_FLAG_SEQUENCE 0x0800 /* Sequence */
+#define L2TP_FLAG_OFFSET 0x0200 /* Offset */
+#define L2TP_FLAG_PRIORITY 0x0100 /* Priority */
-#ifndef TRUE
-#define TRUE 1
-#endif
+#define L2TP_VERSION_MASK 0x000f /* Version Mask */
+#define L2TP_VERSION_L2F 0x0001 /* L2F */
+#define L2TP_VERSION_L2TP 0x0002 /* L2TP */
-#ifndef FALSE
-#define FALSE 0
-#endif
+#define L2TP_AVP_HDR_FLAG_MANDATORY 0x8000 /* Mandatory Flag */
+#define L2TP_AVP_HDR_FLAG_HIDDEN 0x4000 /* Hidden Flag */
+#define L2TP_AVP_HDR_LEN_MASK 0x03ff /* Length Mask */
+
+#define L2TP_FRAMING_CAP_SYNC_MASK 0x00000001 /* Synchronous */
+#define L2TP_FRAMING_CAP_ASYNC_MASK 0x00000002 /* Asynchronous */
+
+#define L2TP_FRAMING_TYPE_SYNC_MASK 0x00000001 /* Synchronous */
+#define L2TP_FRAMING_TYPE_ASYNC_MASK 0x00000002 /* Asynchronous */
+
+#define L2TP_BEARER_CAP_DIGITAL_MASK 0x00000001 /* Digital */
+#define L2TP_BEARER_CAP_ANALOG_MASK 0x00000002 /* Analog */
+
+#define L2TP_BEARER_TYPE_DIGITAL_MASK 0x00000001 /* Digital */
+#define L2TP_BEARER_TYPE_ANALOG_MASK 0x00000002 /* Analog */
+
+/* Authen Type */
+#define L2TP_AUTHEN_TYPE_RESERVED 0x0000 /* Reserved */
+#define L2TP_AUTHEN_TYPE_TEXTUAL 0x0001 /* Textual username/password exchange */
+#define L2TP_AUTHEN_TYPE_CHAP 0x0002 /* PPP CHAP */
+#define L2TP_AUTHEN_TYPE_PAP 0x0003 /* PPP PAP */
+#define L2TP_AUTHEN_TYPE_NO_AUTH 0x0004 /* No Authentication */
+#define L2TP_AUTHEN_TYPE_MSCHAPv1 0x0005 /* MSCHAPv1 */
+
+#define L2TP_PROXY_AUTH_ID_MASK 0x00ff
+
+static const char tstr[] = " [|l2tp]";
#define L2TP_MSGTYPE_SCCRQ 1 /* Start-Control-Connection-Request */
#define L2TP_MSGTYPE_SCCRP 2 /* Start-Control-Connection-Reply */
#define L2TP_MSGTYPE_WEN 15 /* WAN-Error-Notify */
#define L2TP_MSGTYPE_SLI 16 /* Set-Link-Info */
-static struct tok l2tp_msgtype2str[] = {
+static const struct tok l2tp_msgtype2str[] = {
{ L2TP_MSGTYPE_SCCRQ, "SCCRQ" },
{ L2TP_MSGTYPE_SCCRP, "SCCRP" },
{ L2TP_MSGTYPE_SCCCN, "SCCCN" },
#define L2TP_AVP_SEQ_REQUIRED 39 /* Sequencing Required */
#define L2TP_AVP_PPP_DISCON_CC 46 /* PPP Disconnect Cause Code */
-static struct tok l2tp_avp2str[] = {
+static const struct tok l2tp_avp2str[] = {
{ L2TP_AVP_MSGTYPE, "MSGTYPE" },
{ L2TP_AVP_RESULT_CODE, "RESULT_CODE" },
{ L2TP_AVP_PROTO_VER, "PROTO_VER" },
{ 0, NULL }
};
-static struct tok l2tp_authentype2str[] = {
+static const struct tok l2tp_authentype2str[] = {
{ L2TP_AUTHEN_TYPE_RESERVED, "Reserved" },
{ L2TP_AUTHEN_TYPE_TEXTUAL, "Textual" },
{ L2TP_AUTHEN_TYPE_CHAP, "CHAP" },
#define L2TP_PPP_DISCON_CC_DIRECTION_AT_PEER 1
#define L2TP_PPP_DISCON_CC_DIRECTION_AT_LOCAL 2
-static struct tok l2tp_cc_direction2str[] = {
+static const struct tok l2tp_cc_direction2str[] = {
{ L2TP_PPP_DISCON_CC_DIRECTION_GLOBAL, "global error" },
{ L2TP_PPP_DISCON_CC_DIRECTION_AT_PEER, "at peer" },
{ L2TP_PPP_DISCON_CC_DIRECTION_AT_LOCAL,"at local" },
static void
print_string(const u_char *dat, u_int length)
{
- int i;
+ u_int i;
for (i=0; i<length; i++) {
printf("%c", *dat++);
}
static void
print_octets(const u_char *dat, u_int length)
{
- int i;
+ u_int i;
for (i=0; i<length; i++) {
printf("%02x", *dat++);
}
TCHECK(*ptr); /* Flags & Length */
len = EXTRACT_16BITS(ptr) & L2TP_AVP_HDR_LEN_MASK;
- /* If it is not long enough to decode the entire AVP, we'll
- abandon. */
+ /* If it is not long enough to contain the header, we'll give up. */
+ if (len < 6)
+ goto trunc;
+
+ /* If it goes past the end of the remaining length of the packet,
+ we'll give up. */
+ if (len > (u_int)length)
+ goto trunc;
+
+ /* If it goes past the end of the remaining length of the captured
+ data, we'll give up. */
TCHECK2(*ptr, len);
/* After this point, no need to worry about truncation */
void
l2tp_print(const u_char *dat, u_int length)
{
- const u_int16_t *ptr = (u_int16_t *)dat;
+ const u_char *ptr = dat;
u_int cnt = 0; /* total octets consumed */
u_int16_t pad;
- int flag_t, flag_l, flag_s, flag_o, flag_p;
+ int flag_t, flag_l, flag_s, flag_o;
u_int16_t l2tp_len;
- flag_t = flag_l = flag_s = flag_o = flag_p = FALSE;
+ flag_t = flag_l = flag_s = flag_o = FALSE;
- TCHECK(*ptr); /* Flags & Version */
+ TCHECK2(*ptr, 2); /* Flags & Version */
if ((EXTRACT_16BITS(ptr) & L2TP_VERSION_MASK) == L2TP_VERSION_L2TP) {
printf(" l2tp:");
} else if ((EXTRACT_16BITS(ptr) & L2TP_VERSION_MASK) == L2TP_VERSION_L2F) {
flag_o = TRUE;
printf("O");
}
- if (EXTRACT_16BITS(ptr) & L2TP_FLAG_PRIORITY) {
- flag_p = TRUE;
+ if (EXTRACT_16BITS(ptr) & L2TP_FLAG_PRIORITY)
printf("P");
- }
printf("]");
- ptr++;
+ ptr += 2;
cnt += 2;
if (flag_l) {
- TCHECK(*ptr); /* Length */
- l2tp_len = EXTRACT_16BITS(ptr); ptr++;
+ TCHECK2(*ptr, 2); /* Length */
+ l2tp_len = EXTRACT_16BITS(ptr);
+ ptr += 2;
cnt += 2;
} else {
l2tp_len = 0;
}
- TCHECK(*ptr); /* Tunnel ID */
- printf("(%u/", EXTRACT_16BITS(ptr)); ptr++;
+ TCHECK2(*ptr, 2); /* Tunnel ID */
+ printf("(%u/", EXTRACT_16BITS(ptr));
+ ptr += 2;
cnt += 2;
- TCHECK(*ptr); /* Session ID */
- printf("%u)", EXTRACT_16BITS(ptr)); ptr++;
+ TCHECK2(*ptr, 2); /* Session ID */
+ printf("%u)", EXTRACT_16BITS(ptr));
+ ptr += 2;
cnt += 2;
if (flag_s) {
- TCHECK(*ptr); /* Ns */
- printf("Ns=%u,", EXTRACT_16BITS(ptr)); ptr++;
+ TCHECK2(*ptr, 2); /* Ns */
+ printf("Ns=%u,", EXTRACT_16BITS(ptr));
+ ptr += 2;
cnt += 2;
- TCHECK(*ptr); /* Nr */
- printf("Nr=%u", EXTRACT_16BITS(ptr)); ptr++;
+ TCHECK2(*ptr, 2); /* Nr */
+ printf("Nr=%u", EXTRACT_16BITS(ptr));
+ ptr += 2;
cnt += 2;
}
if (flag_o) {
- TCHECK(*ptr); /* Offset Size */
- pad = EXTRACT_16BITS(ptr); ptr++;
- ptr += pad / sizeof(*ptr);
+ TCHECK2(*ptr, 2); /* Offset Size */
+ pad = EXTRACT_16BITS(ptr);
+ ptr += (2 + pad);
cnt += (2 + pad);
}
+ if (flag_l) {
+ if (length < l2tp_len) {
+ printf(" Length %u larger than packet", l2tp_len);
+ return;
+ }
+ length = l2tp_len;
+ }
+ if (length < cnt) {
+ printf(" Length %u smaller than header length", length);
+ return;
+ }
if (flag_t) {
+ if (!flag_l) {
+ printf(" No length");
+ return;
+ }
if (length - cnt == 0) {
printf(" ZLB");
} else {
- l2tp_avp_print((u_char *)ptr, length - cnt);
+ l2tp_avp_print(ptr, length - cnt);
}
} else {
printf(" {");
- ppp_print((u_char *)ptr, length - cnt);
+ ppp_print(ptr, length - cnt);
printf("}");
}
projects / tcpdump / blobdiff