/*
 * Decode and print Zephyr packets.
 *
 *	http://web.mit.edu/zephyr/doc/protocol
 *
 * Copyright (c) 2001 Nickolai Zeldovich <kolya@MIT.EDU>
 * 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, and (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.
 * The name of the author(s) may not 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.
 */

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

#include <netdissect-stdinc.h>

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

#include "netdissect.h"

struct z_packet {
    const char *version;
    int numfields;
    int kind;
    const char *uid;
    int port;
    int auth;
    int authlen;
    const char *authdata;
    const char *class;
    const char *inst;
    const char *opcode;
    const char *sender;
    const char *recipient;
    const char *format;
    int cksum;
    int multi;
    const char *multi_uid;
    /* Other fields follow here.. */
};

enum z_packet_type {
    Z_PACKET_UNSAFE = 0,
    Z_PACKET_UNACKED,
    Z_PACKET_ACKED,
    Z_PACKET_HMACK,
    Z_PACKET_HMCTL,
    Z_PACKET_SERVACK,
    Z_PACKET_SERVNAK,
    Z_PACKET_CLIENTACK,
    Z_PACKET_STAT
};

static const struct tok z_types[] = {
    { Z_PACKET_UNSAFE,		"unsafe" },
    { Z_PACKET_UNACKED,		"unacked" },
    { Z_PACKET_ACKED,		"acked" },
    { Z_PACKET_HMACK,		"hm-ack" },
    { Z_PACKET_HMCTL,		"hm-ctl" },
    { Z_PACKET_SERVACK,		"serv-ack" },
    { Z_PACKET_SERVNAK,		"serv-nak" },
    { Z_PACKET_CLIENTACK,	"client-ack" },
    { Z_PACKET_STAT,		"stat" }
};

static char z_buf[256];

static const char *
parse_field(netdissect_options *ndo, const char **pptr, int *len)
{
    const char *s;

    if (*len <= 0 || !pptr || !*pptr)
	return NULL;
    if (*pptr > (const char *) ndo->ndo_snapend)
	return NULL;

    s = *pptr;
    while (*pptr <= (const char *) ndo->ndo_snapend && *len >= 0 && **pptr) {
	(*pptr)++;
	(*len)--;
    }
    (*pptr)++;
    (*len)--;
    if (*len < 0 || *pptr > (const char *) ndo->ndo_snapend)
	return NULL;
    return s;
}

static const char *
z_triple(const char *class, const char *inst, const char *recipient)
{
    if (!*recipient)
	recipient = "*";
    snprintf(z_buf, sizeof(z_buf), "<%s,%s,%s>", class, inst, recipient);
    z_buf[sizeof(z_buf)-1] = '\0';
    return z_buf;
}

static const char *
str_to_lower(const char *string)
{
    char *zb_string;

    strncpy(z_buf, string, sizeof(z_buf));
    z_buf[sizeof(z_buf)-1] = '\0';

    zb_string = z_buf;
    while (*zb_string) {
	*zb_string = tolower((unsigned char)(*zb_string));
	zb_string++;
    }

    return z_buf;
}

void
zephyr_print(netdissect_options *ndo, const u_char *cp, int length)
{
    struct z_packet z;
    const char *parse = (const char *) cp;
    int parselen = length;
    const char *s;
    int lose = 0;

    /* squelch compiler warnings */

    z.kind = 0;
    z.class = 0;
    z.inst = 0;
    z.opcode = 0;
    z.sender = 0;
    z.recipient = 0;

#define PARSE_STRING				\
	s = parse_field(ndo, &parse, &parselen);	\
	if (!s) lose = 1;

#define PARSE_FIELD_INT(field)			\
	PARSE_STRING				\
	if (!lose) field = strtol(s, 0, 16);

#define PARSE_FIELD_STR(field)			\
	PARSE_STRING				\
	if (!lose) field = s;

    PARSE_FIELD_STR(z.version);
    if (lose) return;
    if (strncmp(z.version, "ZEPH", 4))
	return;

    PARSE_FIELD_INT(z.numfields);
    PARSE_FIELD_INT(z.kind);
    PARSE_FIELD_STR(z.uid);
    PARSE_FIELD_INT(z.port);
    PARSE_FIELD_INT(z.auth);
    PARSE_FIELD_INT(z.authlen