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tcpdump/print-fr.c

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/*
* Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that: (1) source code distributions
* retain the above copyright notice and this paragraph in its entirety, (2)
* distributions including binary code include the above copyright notice and
* this paragraph in its entirety in the documentation or other materials
* provided with the distribution, and (3) all advertising materials mentioning
* features or use of this software display the following acknowledgement:
* ``This product includes software developed by the University of California,
* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
* the University nor the names of its contributors may be used to endorse
* or promote products derived from this software without specific prior
* written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifndef lint
static const char rcsid[] _U_ =
"@(#)$Header: /tcpdump/master/tcpdump/print-fr.c,v 1.24 2004-10-07 16:16:02 hannes Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <tcpdump-stdinc.h>
#include <stdio.h>
#include <string.h>
#include <pcap.h>
#include "addrtoname.h"
#include "interface.h"
#include "ethertype.h"
#include "nlpid.h"
#include "extract.h"
static void lmi_print(const u_char *, u_int);
#define FR_EA_BIT 0x01
/* Finds out Q.922 address length, DLCI and flags. Returns 0 on success */
static int parse_q922_addr(const u_char *p, u_int *dlci, u_int *addr_len,
char **flags_ptr)
{
static char flags[32];
size_t len;
if ((p[0] & FR_EA_BIT))
return -1;
*flags_ptr = flags;
*addr_len = 2;
*dlci = ((p[0] & 0xFC) << 2) | ((p[1] & 0xF0) >> 4);
strcpy(flags, (p[0] & 0x02) ? "C!, " : "");
if (p[1] & 0x08)
strcat(flags, "FECN, ");
if (p[1] & 0x04)
strcat(flags, "BECN, ");
if (p[1] & 0x02)
strcat(flags, "DE, ");
len = strlen(flags);
if (len > 1)
flags[len - 2] = '\x0'; /* delete trailing comma and space */
if (p[1] & FR_EA_BIT)
return 0; /* 2-byte Q.922 address */
p += 2;
(*addr_len)++; /* 3- or 4-byte Q.922 address */
if ((p[0] & FR_EA_BIT) == 0) {
*dlci = (*dlci << 7) | (p[0] >> 1);
(*addr_len)++; /* 4-byte Q.922 address */
p++;
}
if ((p[0] & FR_EA_BIT) == 0)
return -1; /* more than 4 bytes of Q.922 address? */
if (p[0] & 0x02) {
len = strlen(flags);
snprintf(flags + len, sizeof(flags) - len,
"%sdlcore %x", len ? ", " : "", p[0] >> 2);
} else
*dlci = (*dlci << 6) | (p[0] >> 2);
return 0;
}
/* Frame Relay packet structure, with flags and CRC removed
+---------------------------+
| Q.922 Address* |
+-- --+
| |
+---------------------------+
| Control (UI = 0x03) |
+---------------------------+
| Optional Pad (0x00) |
+---------------------------+
| NLPID |
+---------------------------+
| . |
| . |
| . |
| Data |
| . |
| . |
+---------------------------+
* Q.922 addresses, as presently defined, are two octets and
contain a 10-bit DLCI. In some networks Q.922 addresses
may optionally be increased to three or four octets.
*/
static u_int
fr_hdrlen(const u_char *p, u_int addr_len, u_int caplen)
{
if ((caplen > addr_len + 1 /* UI */ + 1 /* pad */) &&
!p[addr_len + 1] /* pad exist */)
return addr_len + 1 /* UI */ + 1 /* pad */ + 1 /* NLPID */;
else
return addr_len + 1 /* UI */ + 1 /* NLPID */;
}
static void
fr_hdr_print(int length, u_int dlci, char *flags, u_char nlpid)
{
if (qflag)
(void)printf("DLCI %u, %s%slength %u: ",
dlci, flags, *flags ? ", " : "", length);
else
(void)printf("DLCI %u, %s%sNLPID %s (0x%02x), length %u: ",
dlci, flags, *flags ? ", " : "",
tok2str(nlpid_values,"unknown", nlpid),
nlpid,
length);
}
u_int
fr_if_print(const struct pcap_pkthdr *h, register const u_char *p)
{
register u_int length = h->len;
register u_int caplen = h->caplen;
u_short extracted_ethertype;
u_int32_t orgcode;
register u_short et;
u_int dlci;
u_int addr_len;
u_char nlpid;
u_int hdr_len;
char *flags;
if (caplen < 4) { /* minimum frame header length */
printf("[|fr]");
return caplen;
}
if (parse_q922_addr(p, &dlci, &addr_len, &flags)) {
printf("Invalid Q.922 address");
return caplen;
}
hdr_len = fr_hdrlen(p, addr_len, caplen);
if (caplen < hdr_len) {
printf("[|fr]");
return caplen;
}
if (p[addr_len] != 0x03) {
/* lets figure out if we have cisco style encapsulation: */
extracted_ethertype = EXTRACT_16BITS(p+addr_len);
if (eflag)
printf("DLCI %u, %s%scisco-ethertype %s (0x%04x), length %u: ",
dlci,
flags,
*flags ? ", " : "",
tok2str(ethertype_values, "unknown", extracted_ethertype),
extracted_ethertype,
length);
if (ether_encap_print(extracted_ethertype,
p+addr_len+ETHERTYPE_LEN,
length-(addr_len),
caplen-(addr_len),
&extracted_ethertype) == 0)
/* ether_type not known, probably it wasn't one */
printf("UI %02x! ", p[addr_len]);
else
return hdr_len;
}
if (!p[addr_len + 1]) { /* pad byte should be used with 3-byte Q.922 */
if (addr_len != 3)
printf("Pad! ");
} else if (addr_len == 3)
printf("No pad! ");
nlpid = p[hdr_len - 1];
p += hdr_len;
length -= hdr_len;
caplen -= hdr_len;
if (eflag)
fr_hdr_print(length, dlci, flags, nlpid);
switch (nlpid) {
case NLPID_IP:
ip_print(p, length);
break;
#ifdef INET6
case NLPID_IP6:
ip6_print(p, length);
break;
#endif
case NLPID_CLNP:
case NLPID_ESIS:
case NLPID_ISIS:
isoclns_print(p, length, caplen);
break;
case NLPID_SNAP:
orgcode = EXTRACT_24BITS(p);
et = EXTRACT_16BITS(p + 3);
if (snap_print((const u_char *)(p + 5), length - 5,
caplen - 5, &extracted_ethertype, orgcode, et,
0) == 0) {
/* ether_type not known, print raw packet */
if (!eflag)
fr_hdr_print(length + hdr_len,
dlci, flags, nlpid);
if (extracted_ethertype) {
printf("(SNAP %s) ",
etherproto_string(htons(extracted_ethertype)));
}
if (!xflag && !qflag)
default_print(p - hdr_len, caplen + hdr_len);
}
break;
case NLPID_LMI:
lmi_print(p, length);
break;
default:
if (!eflag)
fr_hdr_print(length + hdr_len,
dlci, flags, nlpid);
if (!xflag)
default_print(p, caplen);
}
return hdr_len;
}
/*
* Q.933 decoding portion for framerelay specific.
*/
/* Q.933 packet format
Format of Other Protocols
using Q.933 NLPID
+-------------------------------+
| Q.922 Address |
+---------------+---------------+
|Control 0x03 | NLPID 0x08 |
+---------------+---------------+
| L2 Protocol ID |
| octet 1 | octet 2 |
+-------------------------------+
| L3 Protocol ID |
| octet 2 | octet 2 |
+-------------------------------+
| Protocol Data |
+-------------------------------+
| FCS |
+-------------------------------+
*/
/* L2 (Octet 1)- Call Reference Usually is 0x0 */
/*
* L2 (Octet 2)- Message Types definition 1 byte long.
*/
/* Call Establish */
#define MSG_TYPE_ESC_TO_NATIONAL 0x00
#define MSG_TYPE_ALERT 0x01
#define MSG_TYPE_CALL_PROCEEDING 0x02
#define MSG_TYPE_CONNECT 0x07
#define MSG_TYPE_CONNECT_ACK 0x0F
#define MSG_TYPE_PROGRESS 0x03
#define MSG_TYPE_SETUP 0x05
/* Call Clear */
#define MSG_TYPE_DISCONNECT 0x45
#define MSG_TYPE_RELEASE 0x4D
#define MSG_TYPE_RELEASE_COMPLETE 0x5A
#define MSG_TYPE_RESTART 0x46
#define MSG_TYPE_RESTART_ACK 0x4E
/* Status */
#define MSG_TYPE_STATUS 0x7D
#define MSG_TYPE_STATUS_ENQ 0x75
#define MSG_ANSI_LOCKING_SHIFT 0x95
#define ONE_BYTE_IE_MASK 0xF0 /* details? */
#define ANSI_REPORT_TYPE_IE 0x01
#define ANSI_LINK_VERIFY_IE_91 0x19 /* details? */
#define ANSI_LINK_VERIFY_IE 0x03
#define ANSI_PVC_STATUS_IE 0x07
#define CCITT_REPORT_TYPE_IE 0x51
#define CCITT_LINK_VERIFY_IE 0x53
#define CCITT_PVC_STATUS_IE 0x57
struct common_ie_header {
u_int8_t ie_id;
u_int8_t ie_len;
};
#define FULL_STATUS 0
#define LINK_VERIFY 1
#define ASYNC_PVC 2
/* Parses DLCI information element. */
static const char * parse_dlci_ie(const u_char *p, u_int ie_len, char *buffer,
size_t buffer_len)
{
u_int dlci;
if ((ie_len < 3) ||
(p[0] & 0x80) ||
((ie_len == 3) && !(p[1] & 0x80)) ||
((ie_len == 4) && ((p[1] & 0x80) || !(p[2] & 0x80))) ||
((ie_len == 5) && ((p[1] & 0x80) || (p[2] & 0x80) ||
!(p[3] & 0x80))) ||
(ie_len > 5) ||
!(p[ie_len - 1] & 0x80))
return "Invalid DLCI IE";
dlci = ((p[0] & 0x3F) << 4) | ((p[1] & 0x78) >> 3);
if (ie_len == 4)
dlci = (dlci << 6) | ((p[2] & 0x7E) >> 1);
else if (ie_len == 5)
dlci = (dlci << 13) | (p[2] & 0x7F) | ((p[3] & 0x7E) >> 1);
snprintf(buffer, buffer_len, "DLCI %d: status %s%s", dlci,
p[ie_len - 1] & 0x8 ? "New, " : "",
p[ie_len - 1] & 0x2 ? "Active" : "Inactive");
return buffer;
}
static void
lmi_print(const u_char *p, u_int length)
{
const u_char *ptemp = p;
const char *decode_str;
char temp_str[255];
struct common_ie_header *ie_p;
int is_ansi = 0;
if (length < 9) { /* shortest: Q.933a LINK VERIFY */
printf("[|lmi]");
return;
}
if (p[2] == MSG_ANSI_LOCKING_SHIFT)
is_ansi = 1;
/* printing out header part */
printf(is_ansi ? "ANSI" : "CCITT");
if (p[0])
printf(" Call Ref: %02x!", p[0]);
switch(p[1]) {
case MSG_TYPE_STATUS:
printf(" STATUS REPLY\n");
break;
case MSG_TYPE_STATUS_ENQ:
printf(" STATUS ENQUIRY\n");
break;
default:
printf(" UNKNOWN MSG Type %02x\n", p[1]);
break;
}
if (length < (u_int)(2 - is_ansi)) {
printf("[|lmi]");
return;
}
length -= 2 - is_ansi;
ptemp += 2 + is_ansi;
/* Loop through the rest of IE */
while (length > 0) {
ie_p = (struct common_ie_header *)ptemp;
if (length < sizeof(struct common_ie_header) ||
length < sizeof(struct common_ie_header) + ie_p->ie_len) {
printf("[|lmi]");
return;
}
if ((is_ansi && ie_p->ie_id == ANSI_REPORT_TYPE_IE) ||
(!is_ansi && ie_p->ie_id == CCITT_REPORT_TYPE_IE)) {
switch(ptemp[2]) {
case FULL_STATUS:
decode_str = "FULL STATUS";
break;
case LINK_VERIFY:
decode_str = "LINK VERIFY";
break;
case ASYNC_PVC:
decode_str = "Async PVC Status";
break;
default:
decode_str = "Reserved Value";
break;
}
} else if ((is_ansi && (ie_p->ie_id == ANSI_LINK_VERIFY_IE_91 ||
ie_p->ie_id == ANSI_LINK_VERIFY_IE)) ||
(!is_ansi && ie_p->ie_id == CCITT_LINK_VERIFY_IE)) {
snprintf(temp_str, sizeof(temp_str),
"TX Seq: %3d, RX Seq: %3d",
ptemp[2], ptemp[3]);
decode_str = temp_str;
} else if ((is_ansi && ie_p->ie_id == ANSI_PVC_STATUS_IE) ||
(!is_ansi && ie_p->ie_id == CCITT_PVC_STATUS_IE)) {
decode_str = parse_dlci_ie(ptemp + 2, ie_p->ie_len,
temp_str, sizeof(temp_str));
} else
decode_str = "Non-decoded Value";
printf("\t\tIE: %02X Len: %d, %s\n",
ie_p->ie_id, ie_p->ie_len, decode_str);
length = length - ie_p->ie_len - 2;
ptemp = ptemp + ie_p->ie_len + 2;
}
}
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