/*      $OpenBSD: print-llc.c,v 1.23 2023/02/28 10:04:50 claudio Exp $  */

/*
 * 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
 */

#include <sys/time.h>

#include <netinet/in.h>

#include <ctype.h>
#include <netdb.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>

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

#include "llc.h"

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 }
};

/*
 * 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)
{
        struct llc llc;
        u_short et;
#if 0
        u_short control;
#endif
        int ret;

        if (caplen < 3) {
                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) {
                ipx_print(p, length);
                return (1);
        }
#ifdef notyet
        else if (p[0] == 0xf0 && p[1] == 0xf0)
                netbios_print(p, length);
#endif
        if (llc.ssap == LLCSAP_ISONS && llc.dsap == LLCSAP_ISONS
            && llc.llcui == LLC_UI) {
                isoclns_print(p + 3, length - 3, caplen - 3, esrc, edst);
                return (1);
        }

        if (llc.ssap == LLCSAP_SNAP && llc.dsap == LLCSAP_SNAP
            && llc.llcui == LLC_UI) {
                if (caplen < sizeof(llc)) {
                    printf("[|llc-snap]");
                    default_print((u_char *)p, caplen);
                    return (0);
                }

                /* Cisco Discovery Protocol  - SNAP & ether type 0x2000 */
                if (llc.ethertype[0] == 0x20 && llc.ethertype[1] == 0x00) {
                        cdp_print(p, length, caplen, 8);
                        return (1);
                }
                /* Shared Spanning Tree Protocol - SNAP & ether type 0x010b */
                if (llc.ethertype[0] == 0x01 && llc.ethertype[1] == 0x0b) {
                        stp_print(p, length);
                        return (1);
                }

                if (vflag)
                        printf("snap %s ", protoid_string(llc.llcpi));

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

                /* This is an encapsulated Ethernet packet */
                et = EXTRACT_16BITS(&llc.ethertype[0]);

                /*
                 * Some protocols have special handling if they are 802.3
                 * SNAP encapsulated vs vers II encapsulated. Handle
                 * those special protocols here, and hand the rest to
                 * print-ether.c so we don't have to duplicate
                 * all that code here.
                 */
                switch (et) {
                case ETHERTYPE_ATALK:
                        atalk_print(p, length);
                        ret = 1;
                        break;
                default:
                        ret = ether_encap_print(et, p, length, caplen);
                        break;
                }

                if (ret)
                        return (ret);
        }

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

#if 0
        if (llc.ssap == 0xf0 && llc.dsap == 0xf0) {
                /*
                 * 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
                 */

                /*
                 * 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 - S or I
                 * frames have a two-byte control field, and U frames
                 * have a one-byte control field.
                 */
                if ((llc.llcu & LLC_U_FMT) == LLC_U_FMT) {
                        control = llc.llcu;
                        p += 1;
                        length -= 1;
                        caplen -= 1;
                } else {
                        control = llc.llcis;
                        p += 2;
                        length -= 2;
                        caplen -= 2;
                }

                netbeui_print(control, p, p + min(caplen, length));
                return (1);
        }
#endif

        if ((llc.ssap & ~LLC_GSAP) == llc.dsap) {
                if (eflag)
                        printf("%s ", llcsap_string(llc.dsap));
                else
                        printf("%s > %s %s ",
                            etheraddr_string(esrc),
                            etheraddr_string(edst),
                            llcsap_string(llc.dsap));
        } else {
                if (eflag)
                        printf("%s > %s ",
                            llcsap_string(llc.ssap & ~LLC_GSAP),
                            llcsap_string(llc.dsap));
                else
                        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) {
                const char *m;
                char f;
                m = tok2str(cmd2str, "%02x", LLC_U_CMD(llc.llcu));
                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);

                if (caplen < 6) {
                        default_print(p, caplen);
                        return (0);
                }
                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;
                    }
                }

#if 0
                if (!strcmp(m,"ui") && f=='C') {
                        /*
                         * we don't have a proper ipx decoder yet, but there
                         * is a partial one in the smb code
                         */
                        ipx_netbios_print(p,p+min(caplen,length));
                }
#endif

        } else {
                char f;
                if (caplen < 4) {
                        default_print(p, caplen);
                        return (0);
                }
                llc.llcis = ntohs(llc.llcis);
                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;
                }

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