[tcpdump] / print-llc.c

/*
 * Copyright (c) 1992, 1993, 1994, 1995, 1996, 1997
 *      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.
 *
 * Code by Matt Thomas, Digital Equipment Corporation
 *      with an awful lot of hacking by Jeffrey Mogul, DECWRL
 */

#ifndef lint
static const char rcsid[] _U_ =
    "@(#) $Header: /tcpdump/master/tcpdump/print-llc.c,v 1.64 2005-04-26 03:51:38 guy Exp $";
#endif

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <tcpdump-stdinc.h>

#include <stdio.h>
#include <string.h>

#include "interface.h"
#include "addrtoname.h"
#include "extract.h"                    /* must come after interface.h */

#include "llc.h"
#include "ethertype.h"
#include "oui.h"

static struct tok llc_values[] = {
        { LLCSAP_NULL,     "Null" },
        { LLCSAP_GLOBAL,   "Global" },
        { LLCSAP_8021B_I,  "802.1B I" },
        { LLCSAP_8021B_G,  "802.1B G" },
        { LLCSAP_IP,       "IP" },
        { LLCSAP_PROWAYNM, "ProWay NM" },
        { LLCSAP_8021D,    "STP" },
        { LLCSAP_RS511,    "RS511" },
        { LLCSAP_ISO8208,  "ISO8208" },
        { LLCSAP_PROWAY,   "ProWay" },
        { LLCSAP_SNAP,     "SNAP" },
        { LLCSAP_IPX,      "IPX" },
        { LLCSAP_NETBEUI,  "NetBeui" },
        { LLCSAP_ISONS,    "OSI" },
        { 0,               NULL },
};

static struct tok cmd2str[] = {
        { LLC_UI,       "ui" },
        { LLC_TEST,     "test" },
        { LLC_XID,      "xid" },
        { LLC_UA,       "ua" },
        { LLC_DISC,     "disc" },
        { LLC_DM,       "dm" },
        { LLC_SABME,    "sabme" },
        { LLC_FRMR,     "frmr" },
        { 0,            NULL }
};

static const struct tok cisco_values[] = { 
        { PID_CISCO_CDP, "CDP" },
        { 0,             NULL }
};

static const struct tok bridged_values[] = { 
        { PID_RFC2684_ETH_FCS,     "Ethernet + FCS" },
        { PID_RFC2684_ETH_NOFCS,   "Ethernet w/o FCS" },
        { PID_RFC2684_802_4_FCS,   "802.4 + FCS" },
        { PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" },
        { PID_RFC2684_802_5_FCS,   "Token Ring + FCS" },
        { PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" },
        { PID_RFC2684_FDDI_FCS,    "FDDI + FCS" },
        { PID_RFC2684_FDDI_NOFCS,  "FDDI w/o FCS" },
        { PID_RFC2684_802_6_FCS,   "802.6 + FCS" },
        { PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" },
        { PID_RFC2684_BPDU,        "BPDU" },
        { 0,                       NULL },
};

struct oui_tok {
        u_int32_t       oui;
        const struct tok *tok;
};

static const struct oui_tok oui_to_tok[] = {
        { OUI_ENCAP_ETHER, ethertype_values },
        { OUI_CISCO_90, ethertype_values },     /* uses some Ethertype values */
        { OUI_APPLETALK, ethertype_values },    /* uses some Ethertype values */
        { OUI_CISCO, cisco_values },
        { OUI_RFC2684, bridged_values },        /* bridged, RFC 2427 FR or RFC 2864 ATM */
        { 0, NULL }
};

/*
 * Returns non-zero IFF it succeeds in printing the header
 */
int
llc_print(const u_char *p, u_int length, u_int caplen,
          const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
{
        struct llc llc;
        register u_short et;
        u_int16_t control;
        register int ret;

        if (caplen < 3) {
                (void)printf("[|llc]");
                default_print((u_char *)p, caplen);
                return(0);
        }

        /* Watch out for possible alignment problems */
        memcpy((char *)&llc, (char *)p, min(caplen, sizeof(llc)));

        if (llc.ssap == LLCSAP_GLOBAL && llc.dsap == LLCSAP_GLOBAL) {
                /*
                 * This is an Ethernet_802.3 IPX frame; it has an
                 * 802.3 header (i.e., an Ethernet header where the
                 * type/length field is <= ETHERMTU, i.e. it's a length
                 * field, not a type field), but has no 802.2 header -
                 * the IPX packet starts right after the Ethernet header,
                 * with a signature of two bytes of 0xFF (which is
                 * LLCSAP_GLOBAL).
                 *
                 * (It might also have been an Ethernet_802.3 IPX at
                 * one time, but got bridged onto another network,
                 * such as an 802.11 network; this has appeared in at
                 * least one capture file.)
                 */

            if (eflag)
                printf("IPX-802.3: ");

            ipx_print(p, length);
            return (1);
        }

        if (eflag)
          printf("LLC, dsap %s (0x%02x), ssap %s (0x%02x), cmd 0x%02x: ",
                 tok2str(llc_values,"Unknown",llc.dsap),
                 llc.dsap,
                 tok2str(llc_values,"Unknown",llc.ssap),
                 llc.ssap,
                 llc.llcu);

        if (llc.ssap == LLCSAP_8021D && llc.dsap == LLCSAP_8021D) {
                stp_print(p, length);
                return (1);
        }

        if (llc.ssap == LLCSAP_IP && llc.dsap == LLCSAP_IP) {
                ip_print(gndo, p+4, length-4);
                return (1);
        }

        if (llc.ssap == LLCSAP_IPX && llc.dsap == LLCSAP_IPX &&
            llc.llcui == LLC_UI) {
                /*
                 * This is an Ethernet_802.2 IPX frame, with an 802.3
                 * header and an 802.2 LLC header with the source and
                 * destination SAPs being the IPX SAP.
                 *
                 * Skip DSAP, LSAP, and control field.
                 */
                printf("(NOV-802.2) ");
                p += 3;
                length -= 3;
                caplen -= 3;
                ipx_print(p, length);
                return (1);
        }

#ifdef TCPDUMP_DO_SMB
        if (llc.ssap == LLCSAP_NETBEUI && llc.dsap == LLCSAP_NETBEUI
            && (!(llc.llcu & LLC_S_FMT) || llc.llcu == LLC_U_FMT)) {
                /*
                 * we don't actually have a full netbeui parser yet, but the
                 * smb parser can handle many smb-in-netbeui packets, which
                 * is very useful, so we call that
                 *
                 * We don't call it for S frames, however, just I frames
                 * (which are frames that don't have the low-order bit,
                 * LLC_S_FMT, set in the first byte of the control field)
                 * and UI frames (whose control field is just 3, LLC_U_FMT).
                 */

                /*
                 * Skip the DSAP and LSAP.
                 */
                p += 2;
                length -= 2;
                caplen -= 2;

                /*
                 * OK, what type of LLC frame is this?  The length
                 * of the control field depends on that - I frames
                 * have a two-byte control field, and U frames have
                 * a one-byte control field.
                 */
                if (llc.llcu == LLC_U_FMT) {
                        control = llc.llcu;
                        p += 1;
                        length -= 1;
                        caplen -= 1;
                } else {
                        /*
                         * The control field in I and S frames is
                         * little-endian.
                         */
                        control = EXTRACT_LE_16BITS(&llc.llcu);
                        p += 2;
                        length -= 2;
                        caplen -= 2;
                }
                netbeui_print(control, p, length);
                return (1);
        }
#endif
        if (llc.ssap == LLCSAP_ISONS && llc.dsap == LLCSAP_ISONS
            && llc.llcui == LLC_UI) {
                isoclns_print(p + 3, length - 3, caplen - 3);
                return (1);
        }

        if (llc.ssap == LLCSAP_SNAP && llc.dsap == LLCSAP_SNAP
            && llc.llcui == LLC_UI) {
                u_int32_t orgcode;

                if (caplen < sizeof(llc)) {
                        (void)printf("[|llc-snap]");
                        default_print((u_char *)p, caplen);
                        return (0);
                }

                caplen -= sizeof(llc);
                length -= sizeof(llc);
                p += sizeof(llc);

                orgcode = EXTRACT_24BITS(&llc.llc_orgcode[0]);
                et = EXTRACT_16BITS(&llc.llc_ethertype[0]);

                if (eflag) {
                        const struct tok *tok = NULL;
                        const struct oui_tok *otp;

                        for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
                                if (otp->oui == orgcode) {
                                        tok = otp->tok;
                                        break;
                                }
                        }
                        (void)printf("oui %s (0x%06x), %s %s (0x%04x): ",
                             tok2str(oui_values, "Unknown", orgcode),
                             orgcode,
                             (orgcode == 0x000000 ? "ethertype" : "pid"),
                             tok2str(tok, "Unknown", et),
                             et);
                }

                /*
                 * XXX - what *is* the right bridge pad value here?
                 * Does anybody ever bridge one form of LAN traffic
                 * over a networking type that uses 802.2 LLC?
                 */
                ret = snap_print(p, length, caplen, extracted_ethertype,
                    orgcode, et, 2);
                if (ret)
                        return (ret);
        }

        if (!eflag) {
                if ((llc.ssap & ~LLC_GSAP) == llc.dsap) {
                        if (esrc == NULL || edst == NULL)
                                (void)printf("%s ", llcsap_string(llc.dsap));
                        else
                                (void)printf("%s > %s %s ",
                                                etheraddr_string(esrc),
                                                etheraddr_string(edst),
                                                llcsap_string(llc.dsap));
                } else {
                        if (esrc == NULL || edst == NULL)
                                (void)printf("%s > %s ",
                                        llcsap_string(llc.ssap & ~LLC_GSAP),
                                        llcsap_string(llc.dsap));
                        else
                                (void)printf("%s %s > %s %s ",
                                        etheraddr_string(esrc),
                                        llcsap_string(llc.ssap & ~LLC_GSAP),
                                        etheraddr_string(edst),
                                        llcsap_string(llc.dsap));
                }
        }

        if ((llc.llcu & LLC_U_FMT) == LLC_U_FMT) {
                u_int16_t cmd;
                const char *m;
                char f;

                cmd = LLC_U_CMD(llc.llcu);
                m = tok2str(cmd2str, "%02x", cmd);
                switch ((llc.ssap & LLC_GSAP) | (llc.llcu & LLC_U_POLL)) {
                        case 0:                 f = 'C'; break;
                        case LLC_GSAP:          f = 'R'; break;
                        case LLC_U_POLL:        f = 'P'; break;
                        case LLC_GSAP|LLC_U_POLL: f = 'F'; break;
                        default:                f = '?'; break;
                }

                printf("%s/%c", m, f);

                p += 3;
                length -= 3;
                caplen -= 3;

                if ((llc.llcu & ~LLC_U_POLL) == LLC_XID) {
                        if (*p == LLC_XID_FI) {
                                printf(": %02x %02x", p[1], p[2]);
                                p += 3;
                                length -= 3;
                                caplen -= 3;
                        }
                }
        } else {
                char f;

                /*
                 * The control field in I and S frames is little-endian.
                 */
                control = EXTRACT_LE_16BITS(&llc.llcu);
                switch ((llc.ssap & LLC_GSAP) | (control & LLC_IS_POLL)) {
                        case 0:                 f = 'C'; break;
                        case LLC_GSAP:          f = 'R'; break;
                        case LLC_IS_POLL:       f = 'P'; break;
                        case LLC_GSAP|LLC_IS_POLL: f = 'F'; break;
                        default:                f = '?'; break;
                }

                if ((control & LLC_S_FMT) == LLC_S_FMT) {
                        static const char *llc_s[] = { "rr", "rej", "rnr", "03" };
                        (void)printf("%s (r=%d,%c)",
                                llc_s[LLC_S_CMD(control)],
                                LLC_IS_NR(control),
                                f);
                } else {
                        (void)printf("I (s=%d,r=%d,%c)",
                                LLC_I_NS(control),
                                LLC_IS_NR(control),
                                f);
                }
                p += 4;
                length -= 4;
                caplen -= 4;
        }
        return(1);
}

int
snap_print(const u_char *p, u_int length, u_int caplen,
    u_short *extracted_ethertype, u_int32_t orgcode, u_short et,
    u_int bridge_pad)
{
        register int ret;

        switch (orgcode) {
        case OUI_ENCAP_ETHER:
        case OUI_CISCO_90:
                /*
                 * This is an encapsulated Ethernet packet,
                 * or a packet bridged by some piece of
                 * Cisco hardware; the protocol ID is
                 * an Ethernet protocol type.
                 */
                ret = ether_encap_print(et, p, length, caplen,
                    extracted_ethertype);
                if (ret)
                        return (ret);
                break;

        case OUI_APPLETALK:
                if (et == ETHERTYPE_ATALK) {
                        /*
                         * No, I have no idea why Apple used one
                         * of their own OUIs, rather than
                         * 0x000000, and an Ethernet packet
                         * type, for Appletalk data packets,
                         * but used 0x000000 and an Ethernet
                         * packet type for AARP packets.
                         */
                        ret = ether_encap_print(et, p, length, caplen,
                            extracted_ethertype);
                        if (ret)
                                return (ret);
                }
                break;

        case OUI_CISCO:
                if (et == PID_CISCO_CDP) {
                        cdp_print(p, length, caplen);
                        return (1);
                }
                break;

        case OUI_RFC2684:
                switch (et) {

                case PID_RFC2684_ETH_FCS:
                case PID_RFC2684_ETH_NOFCS:
                        /*
                         * XXX - remove the last two bytes for
                         * PID_RFC2684_ETH_FCS?
                         */
                        /*
                         * Skip the padding.
                         */
                        caplen -= bridge_pad;
                        length -= bridge_pad;
                        p += bridge_pad;

                        /*
                         * What remains is an Ethernet packet.
                         */
                        ether_print(p, length, caplen);
                        return (1);

                case PID_RFC2684_802_5_FCS:
                case PID_RFC2684_802_5_NOFCS:
                        /*
                         * XXX - remove the last two bytes for
                         * PID_RFC2684_ETH_FCS?
                         */
                        /*
                         * Skip the padding, but not the Access
                         * Control field.
                         */
                        caplen -= bridge_pad;
                        length -= bridge_pad;
                        p += bridge_pad;

                        /*
                         * What remains is an 802.5 Token Ring
                         * packet.
                         */
                        token_print(p, length, caplen);
                        return (1);

                case PID_RFC2684_FDDI_FCS:
                case PID_RFC2684_FDDI_NOFCS:
                        /*
                         * XXX - remove the last two bytes for
                         * PID_RFC2684_ETH_FCS?
                         */
                        /*
                         * Skip the padding.
                         */
                        caplen -= bridge_pad + 1;
                        length -= bridge_pad + 1;
                        p += bridge_pad + 1;

                        /*
                         * What remains is an FDDI packet.
                         */
                        fddi_print(p, length, caplen);
                        return (1);

                case PID_RFC2684_BPDU:
                        stp_print(p, length);
                        return (1);
                }
        }
        return (0);
}


/*
 * Local Variables:
 * c-style: whitesmith
 * c-basic-offset: 8
 * End:
 */