nbp_lkup_async.c

/*
 * Asnychrounous NBP lookup
 *
 * Original work (c) 1997 Stefan Bethke. All rights reserved.
 * Modified work (c) 2015 Jason King. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice unmodified, this list of conditions, and the following
 *    disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * Copyright (c) 1990,1996 Regents of The University of Michigan.
 * All Rights Reserved.
 * 
 *     Permission to use, copy, modify, and distribute this software and
 *     its documentation for any purpose and without fee is hereby granted,
 *     provided that the above copyright notice appears in all copies and
 *     that both that copyright notice and this permission notice appear
 *     in supporting documentation, and that the name of The University
 *     of Michigan not be used in advertising or publicity pertaining to
 *     distribution of the software without specific, written prior
 *     permission. This software is supplied as is without expressed or
 *     implied warranties of any kind.
 */


#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/signal.h>
#include <sys/time.h>
#include <string.h>
#include <netatalk/endian.h>
#include <netatalk/at.h>
#include <atalk/ddp.h>
#include <netdb.h>

#include "nbp_lkup_async.h"

extern int nbp_parse (char *, struct nbpnve *, int);

static char *nbp_addstring (char *p, char *s) {
	int i;
	if (s) {
		if ((i = strlen (s)) > NBPSTRLEN )
			i=31;
		*p++ = i;
		bcopy (s, p, i);
		p += i;
	} else {
		*p++ = 0;
	}
	return p;
}

static char *nbp_addtuple (char *p, struct sockaddr_at addr, 
	char *name, char *type, char *zone) {
	struct nbptuple		nt;
	
	nt.nt_net = addr.sat_addr.s_net;
	nt.nt_node = addr.sat_addr.s_node;
	nt.nt_port = addr.sat_port;
	bcopy( &nt, p, SZ_NBPTUPLE);
	p += SZ_NBPTUPLE;
	p = nbp_addstring (p, name);
	p = nbp_addstring (p, type);
	p = nbp_addstring (p, zone);
	return p;
}

int nbp_lookup_req (int s, char *name, char *type, char *zone) {
	static int		rqid = 1;
	static int		nbp_port = 0;
	struct sockaddr_at	addr;
	unsigned int		i;
	char			buffer[500];
	char			*p = buffer;
	struct nbphdr		nh;
	struct servent		*se;

	i = sizeof (struct sockaddr_at);
	if (getsockname (s, (struct sockaddr *)&addr, &i) < 0 ) {
		return( -1 );
	}

	*p++ = DDPTYPE_NBP;
	nh.nh_op = NBPOP_BRRQ;
	nh.nh_cnt = 1;
	nh.nh_id = rqid++;
	bcopy( &nh, p, SZ_NBPHDR );
	p += SZ_NBPHDR;
	p = nbp_addtuple (p, addr, name, type, zone);

	bzero( &addr, sizeof( struct sockaddr_at ));
	addr.sat_family = AF_APPLETALK;
	addr.sat_addr.s_net = ATADDR_ANYNET;
	addr.sat_addr.s_node = ATADDR_ANYNODE;
	if ( nbp_port == 0 ) {
		if (( se = getservbyname( "nbp", "ddp" )) == NULL ) {
			nbp_port = 2;
		} else {
			nbp_port = ntohs( se->s_port );
		}
	}
	addr.sat_port = nbp_port;

#ifdef EBUG
	printf ("looking up '%s:%s@%s'\n", name, type, zone);
#endif
	if ( sendto( s, buffer, p-buffer, 0, (struct sockaddr *)&addr,
			sizeof( struct sockaddr_at )) < 0 ) {
		return( -1 );
	}
	return 0;
}

struct nbpnve *nbp_parse_lkup_repl (char *buffer, int len) {
	static char				*lastbuffer = 0;
	static char				*nexttuple  = 0;
	static struct nbpnve	nve;
	struct nbphdr			*nh;
	int						i;

	if (lastbuffer != buffer) {		/* new packet */
		lastbuffer = buffer;
		nexttuple = 0;
		if ( *buffer++ != DDPTYPE_NBP ) {
			return 0;
		}
		len--;

		nh = (struct nbphdr*)buffer;
		buffer += SZ_NBPHDR;
		if ( nh->nh_op != NBPOP_LKUPREPLY ) {
			return 0;
		}
		len -= SZ_NBPHDR;
		nexttuple = buffer;
	} else {
		len -= nexttuple - buffer;
	}
	i = nbp_parse (nexttuple, &nve, len);
	if (i >= 0) {
		nexttuple += len - i;
#ifdef EBUG
	printf ("received nbp entry '%0.*s:%0.*s@%0.*s'\n", 
		nve.nn_objlen, nve.nn_obj,
		nve.nn_typelen, nve.nn_type,
		nve.nn_zonelen, nve.nn_zone);
#endif
		return &nve;
	}
	lastbuffer = 0;
	nexttuple = 0;
	return 0;
}