tcpdump/print-fr.c
guy fead98c71d Make "snap_print()" handle fetching and printing the OUI.
Don't copy the LLC header to a "struct llc", just construct the
individual fields.

Fetch the control field early in the dissection process, and check to
make sure we have at least 4 bytes of LLC header if it's not a U frame.
Fetch both bytes of the control field for I and S frames, and display
all 4 hex digits of it.

Only dissect UI frames as BPDUs, and pass the BPDU dissector a pointer
to the beginning of the BPDU, not the beginning of the LLC header - not
all BPDUs are encapsulated in LLC headers.

Only dissect UI frames as IP packets.

Do bounds checking in "snap_print()".
2005-04-26 07:26:33 +00:00

632 lines
19 KiB
C

/*
* 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 1.35 2005-04-26 07:26:34 guy 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"
#include "oui.h"
static void frf15_print(const u_char *, u_int);
/*
* the frame relay header has a variable length
*
* the EA bit determines if there is another byte
* in the header
*
* minimum header length is 2 bytes
* maximum header length is 4 bytes
*
* 7 6 5 4 3 2 1 0
* +----+----+----+----+----+----+----+----+
* | DLCI (6 bits) | CR | EA |
* +----+----+----+----+----+----+----+----+
* | DLCI (4 bits) |FECN|BECN| DE | EA |
* +----+----+----+----+----+----+----+----+
* | DLCI (7 bits) | EA |
* +----+----+----+----+----+----+----+----+
* | DLCI (6 bits) |SDLC| EA |
* +----+----+----+----+----+----+----+----+
*/
#define FR_EA_BIT 0x01
#define FR_CR_BIT 0x02000000
#define FR_DE_BIT 0x00020000
#define FR_BECN_BIT 0x00040000
#define FR_FECN_BIT 0x00080000
#define FR_SDLC_BIT 0x00000002
struct tok fr_header_flag_values[] = {
{ FR_CR_BIT, "C!" },
{ FR_DE_BIT, "DE" },
{ FR_BECN_BIT, "BECN" },
{ FR_FECN_BIT, "FECN" },
{ FR_SDLC_BIT, "sdlcore" },
{ 0, NULL }
};
/* Finds out Q.922 address length, DLCI and flags. Returns 0 on success
* save the flags dep. on address length
*/
static int parse_q922_addr(const u_char *p, u_int *dlci, u_int *sdlcore,
u_int *addr_len, u_int8_t *flags)
{
if ((p[0] & FR_EA_BIT))
return -1;
*addr_len = 2;
*dlci = ((p[0] & 0xFC) << 2) | ((p[1] & 0xF0) >> 4);
flags[0] = p[0] & 0x02; /* populate the first flag fields */
flags[1] = p[1] & 0x0c;
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? */
flags[3] = p[0] & 0x02;
if (p[0] & 0x02)
*sdlcore = 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 addr_len, u_int dlci, u_int8_t *flags, u_int16_t nlpid)
{
if (qflag) {
(void)printf("Q.922, DLCI %u, length %u: ",
dlci,
length);
} else {
if (nlpid <= 0xff) /* if its smaller than 256 then its a NLPID */
(void)printf("Q.922, hdr-len %u, DLCI %u, Flags [%s], NLPID %s (0x%02x), length %u: ",
addr_len,
dlci,
bittok2str(fr_header_flag_values, "none", EXTRACT_32BITS(flags)),
tok2str(nlpid_values,"unknown", nlpid),
nlpid,
length);
else /* must be an ethertype */
(void)printf("Q.922, hdr-len %u, DLCI %u, Flags [%s], cisco-ethertype %s (0x%04x), length %u: ",
addr_len,
dlci,
bittok2str(fr_header_flag_values, "none", EXTRACT_32BITS(flags)),
tok2str(ethertype_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_int16_t extracted_ethertype;
u_int dlci;
u_int sdlcore;
u_int addr_len;
u_int16_t nlpid;
u_int hdr_len;
u_int8_t flags[4];
if (caplen < 4) { /* minimum frame header length */
printf("[|fr]");
return caplen;
}
if (parse_q922_addr(p, &dlci, &sdlcore, &addr_len, flags)) {
printf("Q.922, invalid address");
return caplen;
}
hdr_len = fr_hdrlen(p, addr_len, caplen);
if (caplen < hdr_len) {
printf("[|fr]");
return caplen;
}
if (p[addr_len] != 0x03 && dlci != 0) {
/* lets figure out if we have cisco style encapsulation: */
extracted_ethertype = EXTRACT_16BITS(p+addr_len);
if (eflag)
fr_hdr_print(length, addr_len, dlci, flags, extracted_ethertype);
if (ether_encap_print(extracted_ethertype,
p+addr_len+ETHERTYPE_LEN,
length-addr_len-ETHERTYPE_LEN,
caplen-addr_len-ETHERTYPE_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];
if (eflag)
fr_hdr_print(length, addr_len, dlci, flags, nlpid);
p += hdr_len;
length -= hdr_len;
caplen -= hdr_len;
switch (nlpid) {
case NLPID_IP:
ip_print(gndo, 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-1, length+1, caplen+1); /* OSI printers need the NLPID field */
break;
case NLPID_SNAP:
if (snap_print(p, length, caplen, &extracted_ethertype, 0) == 0) {
/* ether_type not known, print raw packet */
if (!eflag)
fr_hdr_print(length + hdr_len, hdr_len,
dlci, flags, nlpid);
if (!xflag && !qflag)
default_print(p - hdr_len, caplen + hdr_len);
}
break;
case NLPID_Q933:
q933_print(p, length);
break;
case NLPID_MFR:
frf15_print(p, length);
break;
default:
if (!eflag)
fr_hdr_print(length + hdr_len, addr_len,
dlci, flags, nlpid);
if (!xflag)
default_print(p, caplen);
}
return hdr_len;
}
/* an NLPID of 0xb1 indicates a 2-byte
* FRF.15 header
*
* 7 6 5 4 3 2 1 0
* +----+----+----+----+----+----+----+----+
* ~ Q.922 header ~
* +----+----+----+----+----+----+----+----+
* | NLPID (8 bits) | NLPID=0xb1
* +----+----+----+----+----+----+----+----+
* | B | E | C |seq. (high 4 bits) | R |
* +----+----+----+----+----+----+----+----+
* | sequence (low 8 bits) |
* +----+----+----+----+----+----+----+----+
*/
struct tok frf15_flag_values[] = {
{ 0x80, "Begin" },
{ 0x40, "End" },
{ 0x20, "Control" },
{ 0, NULL }
};
#define FR_FRF15_FRAGTYPE 0x01
static void
frf15_print (const u_char *p, u_int length) {
u_int16_t sequence_num, flags;
flags = p[0]&0xe0;
sequence_num = (p[0]&0x1e)<<7 | p[1];
printf("FRF.15, seq 0x%03x, Flags [%s],%s Fragmentation, length %u",
sequence_num,
bittok2str(frf15_flag_values,"none",flags),
flags&FR_FRF15_FRAGTYPE ? "Interface" : "End-to-End",
length);
/* TODO:
* depending on all permutations of the B, E and C bit
* dig as deep as we can - e.g. on the first (B) fragment
* there is enough payload to print the IP header
* on non (B) fragments it depends if the fragmentation
* model is end-to-end or interface based wether we want to print
* another Q.922 header
*/
}
/*
* 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
struct tok fr_q933_msg_values[] = {
{ MSG_TYPE_ESC_TO_NATIONAL, "ESC to National" },
{ MSG_TYPE_ALERT, "Alert" },
{ MSG_TYPE_CALL_PROCEEDING, "Call proceeding" },
{ MSG_TYPE_CONNECT, "Connect" },
{ MSG_TYPE_CONNECT_ACK, "Connect ACK" },
{ MSG_TYPE_PROGRESS, "Progress" },
{ MSG_TYPE_SETUP, "Setup" },
{ MSG_TYPE_DISCONNECT, "Disconnect" },
{ MSG_TYPE_RELEASE, "Release" },
{ MSG_TYPE_RELEASE_COMPLETE, "Release Complete" },
{ MSG_TYPE_RESTART, "Restart" },
{ MSG_TYPE_RESTART_ACK, "Restart ACK" },
{ MSG_TYPE_STATUS, "Status Reply" },
{ MSG_TYPE_STATUS_ENQ, "Status Enquiry" },
{ 0, NULL }
};
#define MSG_ANSI_LOCKING_SHIFT 0x95
#define FR_LMI_ANSI_REPORT_TYPE_IE 0x01
#define FR_LMI_ANSI_LINK_VERIFY_IE_91 0x19 /* details? */
#define FR_LMI_ANSI_LINK_VERIFY_IE 0x03
#define FR_LMI_ANSI_PVC_STATUS_IE 0x07
#define FR_LMI_CCITT_REPORT_TYPE_IE 0x51
#define FR_LMI_CCITT_LINK_VERIFY_IE 0x53
#define FR_LMI_CCITT_PVC_STATUS_IE 0x57
struct tok fr_q933_ie_values_codeset5[] = {
{ FR_LMI_ANSI_REPORT_TYPE_IE, "ANSI Report Type" },
{ FR_LMI_ANSI_LINK_VERIFY_IE_91, "ANSI Link Verify" },
{ FR_LMI_ANSI_LINK_VERIFY_IE, "ANSI Link Verify" },
{ FR_LMI_ANSI_PVC_STATUS_IE, "ANSI PVC Status" },
{ FR_LMI_CCITT_REPORT_TYPE_IE, "CCITT Report Type" },
{ FR_LMI_CCITT_LINK_VERIFY_IE, "CCITT Link Verify" },
{ FR_LMI_CCITT_PVC_STATUS_IE, "CCITT PVC Status" },
{ 0, NULL }
};
#define FR_LMI_REPORT_TYPE_IE_FULL_STATUS 0
#define FR_LMI_REPORT_TYPE_IE_LINK_VERIFY 1
#define FR_LMI_REPORT_TYPE_IE_ASYNC_PVC 2
struct tok fr_lmi_report_type_ie_values[] = {
{ FR_LMI_REPORT_TYPE_IE_FULL_STATUS, "Full Status" },
{ FR_LMI_REPORT_TYPE_IE_LINK_VERIFY, "Link verify" },
{ FR_LMI_REPORT_TYPE_IE_ASYNC_PVC, "Async PVC Status" },
{ 0, NULL }
};
/* array of 16 codepages - currently we only support codepage 5 */
static struct tok *fr_q933_ie_codesets[] = {
NULL,
NULL,
NULL,
NULL,
NULL,
fr_q933_ie_values_codeset5,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL
};
struct common_ie_header {
u_int8_t ie_id;
u_int8_t ie_len;
};
static int fr_q933_print_ie_codeset5(const struct common_ie_header *ie_p,
const u_char *p);
typedef int (*codeset_pr_func_t)(const struct common_ie_header *ie_p,
const u_char *p);
/* array of 16 codepages - currently we only support codepage 5 */
static codeset_pr_func_t fr_q933_print_ie_codeset[] = {
NULL,
NULL,
NULL,
NULL,
NULL,
fr_q933_print_ie_codeset5,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL
};
void
q933_print(const u_char *p, u_int length)
{
const u_char *ptemp = p;
struct common_ie_header *ie_p;
int olen;
int is_ansi = 0;
u_int codeset;
if (length < 9) { /* shortest: Q.933a LINK VERIFY */
printf("[|q.933]");
return;
}
codeset = p[2]&0x0f; /* extract the codeset */
if (p[2] == MSG_ANSI_LOCKING_SHIFT)
is_ansi = 1;
printf("%s", eflag ? "" : "Q.933, ");
/* printing out header part */
printf(is_ansi ? "ANSI" : "CCITT");
if (p[0])
printf(", Call Ref: 0x%02x", p[0]);
if (vflag)
printf(", %s (0x%02x), length %u",
tok2str(fr_q933_msg_values,"unknown message",p[1]),
p[1],
length);
else
printf(", %s",
tok2str(fr_q933_msg_values,"unknown message 0x%02x",p[1]));
olen = length; /* preserve the original length for non verbose mode */
if (length < (u_int)(2 - is_ansi)) {
printf("[|q.933]");
return;
}
length -= 2 - is_ansi;
ptemp += 2 + is_ansi;
/* Loop through the rest of IE */
while (length > sizeof(struct common_ie_header)) {
ie_p = (struct common_ie_header *)ptemp;
if (length < sizeof(struct common_ie_header) ||
length < sizeof(struct common_ie_header) + ie_p->ie_len) {
if (vflag) /* not bark if there is just a trailer */
printf("\n[|q.933]");
else
printf(", length %u",olen);
return;
}
/* lets do the full IE parsing only in verbose mode
* however some IEs (DLCI Status, Link Verify)
* are also intereststing in non-verbose mode */
if (vflag)
printf("\n\t%s IE (%u), length %u: ",
tok2str(fr_q933_ie_codesets[codeset],"unknown",ie_p->ie_id),
ie_p->ie_id,
ie_p->ie_len);
if (!fr_q933_print_ie_codeset[codeset] ||
(*fr_q933_print_ie_codeset[codeset])(ie_p, ptemp)) {
if (vflag <= 1)
print_unknown_data(ptemp+2,"\n\t",ie_p->ie_len);
}
/* do we want to see a hexdump of the IE ? */
if (vflag> 1)
print_unknown_data(ptemp+2,"\n\t ",ie_p->ie_len);
length = length - ie_p->ie_len - 2;
ptemp = ptemp + ie_p->ie_len + 2;
}
if (!vflag)
printf(", length %u",olen);
}
static int
fr_q933_print_ie_codeset5(const struct common_ie_header *ie_p, const u_char *p)
{
u_int dlci;
switch (ie_p->ie_id) {
case FR_LMI_ANSI_REPORT_TYPE_IE: /* fall through */
case FR_LMI_CCITT_REPORT_TYPE_IE:
if (vflag)
printf("%s (%u)",
tok2str(fr_lmi_report_type_ie_values,"unknown",p[2]),
p[2]);
return 1;
case FR_LMI_ANSI_LINK_VERIFY_IE: /* fall through */
case FR_LMI_CCITT_LINK_VERIFY_IE:
case FR_LMI_ANSI_LINK_VERIFY_IE_91:
if (!vflag)
printf(", ");
printf("TX Seq: %3d, RX Seq: %3d", p[2], p[3]);
return 1;
case FR_LMI_ANSI_PVC_STATUS_IE: /* fall through */
case FR_LMI_CCITT_PVC_STATUS_IE:
if (!vflag)
printf(", ");
/* now parse the DLCI information element. */
if ((ie_p->ie_len < 3) ||
(p[2] & 0x80) ||
((ie_p->ie_len == 3) && !(p[3] & 0x80)) ||
((ie_p->ie_len == 4) && ((p[3] & 0x80) || !(p[4] & 0x80))) ||
((ie_p->ie_len == 5) && ((p[3] & 0x80) || (p[4] & 0x80) ||
!(p[5] & 0x80))) ||
(ie_p->ie_len > 5) ||
!(p[ie_p->ie_len + 1] & 0x80))
printf("Invalid DLCI IE");
dlci = ((p[2] & 0x3F) << 4) | ((p[3] & 0x78) >> 3);
if (ie_p->ie_len == 4)
dlci = (dlci << 6) | ((p[4] & 0x7E) >> 1);
else if (ie_p->ie_len == 5)
dlci = (dlci << 13) | (p[4] & 0x7F) | ((p[5] & 0x7E) >> 1);
printf("DLCI %u: status %s%s", dlci,
p[ie_p->ie_len + 1] & 0x8 ? "New, " : "",
p[ie_p->ie_len + 1] & 0x2 ? "Active" : "Inactive");
return 1;
}
return 0;
}