/* * Copyright (c) 1985, 1988 Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms are permitted * provided that: (1) source distributions retain this entire copyright * notice and comment, and (2) distributions including binaries display * the following acknowledgement:  ``This product includes software * developed by the University of California, Berkeley and its contributors'' * in the documentation or other materials provided with the distribution * and in all advertising materials mentioning features or use of this * software. 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. */#if defined(LIBC_SCCS) && !defined(lint)static char sccsid[] = "@(#)gethostnamadr.c	6.41 (Berkeley) 6/1/90";#endif /* LIBC_SCCS and not lint */#ifdef _MINIX#include <sys/types.h>#include <ctype.h>#include <errno.h>#include <stdio.h>#include <string.h>#include <net/hton.h>#include <net/gen/nameser.h>#include <net/gen/netdb.h>#include <net/gen/in.h>#include <net/gen/inet.h>#include <net/gen/resolv.h>#include <net/gen/socket.h>#else#include <sys/param.h>#include <sys/socket.h>#include <netinet/in.h>#include <ctype.h>#include <netdb.h>#include <stdio.h>#include <errno.h>#include <arpa/inet.h>#include <arpa/nameser.h>#include <resolv.h>#endif /* AMOEABA */#define	MAXALIASES	35#define	MAXADDRS	35static char *h_addr_ptrs[MAXADDRS + 1];#ifdef _MINIXstruct in_addr{	ipaddr_t s_addr;};union querybuf;extern int dn_skipname _ARGS(( const u_char *comp_dn, const u_char *eom ));#define getshort _getshortstatic struct hostent *getanswer _ARGS(( union querybuf *answer, int anslen, 	int iquery ));#define bcmp memcmp#define bcopy(s, d, l) memcpy(d, s, l)#endif /* _MINIX */static struct hostent host;static char *host_aliases[MAXALIASES];static char hostbuf[BUFSIZ+1];static struct in_addr host_addr;#ifndef _MINIXchar *strpbrk();#endif /* !_MINIX */#if PACKETSZ > 1024#define	MAXPACKET	PACKETSZ#else#define	MAXPACKET	1024#endiftypedef union querybuf{	dns_hdr_t hdr;	u_char buf[MAXPACKET];} querybuf_t;typedef union align {    long al;    char ac;} align_t;static struct hostent *getanswer(answer, anslen, iquery)	querybuf_t *answer;	int anslen;	int iquery;{	register dns_hdr_t *hp;	register u_char *cp;	register int n;	u_char *eom;	char *bp, **ap;	int type, class, buflen, ancount, qdcount;	int haveanswer, getclass = C_ANY;	char **hap;	eom = answer->buf + anslen;	/*	 * find first satisfactory answer	 */	hp = &answer->hdr;	ancount = ntohs(hp->dh_ancount);	qdcount = ntohs(hp->dh_qdcount);	bp = hostbuf;	buflen = sizeof(hostbuf);	cp = answer->buf + sizeof(dns_hdr_t);	if (qdcount) {		if (iquery) {			if ((n = dn_expand((u_char *)answer->buf, eom,			     cp, (u_char *)bp, buflen)) < 0) {				h_errno = NO_RECOVERY;				return ((struct hostent *) NULL);			}			cp += n + QFIXEDSZ;			host.h_name = bp;			n = strlen(bp) + 1;			bp += n;			buflen -= n;		} else			cp += dn_skipname(cp, eom) + QFIXEDSZ;		while (--qdcount > 0)			cp += dn_skipname(cp, eom) + QFIXEDSZ;	} else if (iquery) {		if (hp->dh_flag1 & DHF_AA)			h_errno = HOST_NOT_FOUND;		else			h_errno = TRY_AGAIN;		return ((struct hostent *) NULL);	}	ap = host_aliases;	*ap = NULL;	host.h_aliases = host_aliases;	hap = h_addr_ptrs;	*hap = NULL;#if BSD >= 43 || defined(h_addr)	/* new-style hostent structure */	host.h_addr_list = h_addr_ptrs;#endif	haveanswer = 0;	while (--ancount >= 0 && cp < eom) {		if ((n = dn_expand((u_char *)answer->buf, eom, cp, (u_char *)bp,			buflen)) < 0)			break;		cp += n;		type = getshort(cp); 		cp += sizeof(u_short);		class = getshort(cp); 		cp += sizeof(u_short) + sizeof(u_long);		n = getshort(cp);		cp += sizeof(u_short);		if (type == T_CNAME) {			cp += n;			if (ap >= &host_aliases[MAXALIASES-1])				continue;			*ap++ = bp;			n = strlen(bp) + 1;			bp += n;			buflen -= n;			continue;		}		if (iquery && type == T_PTR) {			if ((n = dn_expand((u8_t *)answer->buf, eom,			    cp, (u8_t *)bp, buflen)) < 0) {				cp += n;				continue;			}			cp += n;			host.h_name = bp;			return(&host);		}		if (iquery || type != T_A)  {#ifdef DEBUG			if (_res.options & RES_DEBUG)				printf("unexpected answer type %d, size %d\n",					type, n);#endif			cp += n;			continue;		}		if (haveanswer) {			if (n != host.h_length) {				cp += n;				continue;			}			if (class != getclass) {				cp += n;				continue;			}		} else {			host.h_length = n;			getclass = class;			host.h_addrtype = (class == C_IN) ? AF_INET : AF_UNSPEC;			if (!iquery) {				host.h_name = bp;				bp += strlen(bp) + 1;			}		}		bp += (size_t)(sizeof(align_t) - 						((u_long)bp % sizeof(align_t)));		if (bp + n >= &hostbuf[sizeof(hostbuf)]) {#ifdef DEBUG			if (_res.options & RES_DEBUG)				printf("size (%d) too big\n", n);#endif			break;		}		bcopy(cp, *hap++ = bp, n);		bp +=n;		cp += n;		haveanswer++;	}	if (haveanswer) {		*ap = NULL;#if BSD >= 43 || defined(h_addr)	/* new-style hostent structure */		*hap = NULL;#else		host.h_addr = h_addr_ptrs[0];#endif		return (&host);	} else {		h_errno = TRY_AGAIN;		return ((struct hostent *) NULL);	}}struct hostent *gethostbyname(name)	_CONST char *name;{	querybuf_t buf;	register _CONST char *cp;	int n;	/*	 * disallow names consisting only of digits/dots, unless	 * they end in a dot.	 */	if (isdigit(name[0]))		for (cp = name;; ++cp) {			if (!*cp) {				if (*--cp == '.')					break;				/*				 * All-numeric, no dot at the end.				 * Fake up a hostent as if we'd actually				 * done a lookup.  What if someone types				 * 255.255.255.255?  The test below will				 * succeed spuriously... ???				 */				if ((host_addr.s_addr = inet_addr(name)) == -1) {					h_errno = HOST_NOT_FOUND;					return((struct hostent *) NULL);				}				host.h_name = (char *) name;				host.h_aliases = host_aliases;				host_aliases[0] = NULL;				host.h_addrtype = AF_INET;				host.h_length = sizeof(u_long);				h_addr_ptrs[0] = (char *)&host_addr;				h_addr_ptrs[1] = (char *)0;#if BSD >= 43 || defined(h_addr)	/* new-style hostent structure */				host.h_addr_list = h_addr_ptrs;#else				host.h_addr = h_addr_ptrs[0];#endif				return (&host);			}			if (!isdigit(*cp) && *cp != '.') 				break;		}	if ((n = res_search((char*)name, C_IN, T_A, buf.buf, sizeof(buf))) < 0) {#ifdef DEBUG		if (_res.options & RES_DEBUG)			printf("res_search failed\n");#endif		return ((struct hostent *) NULL);	}	return (getanswer(&buf, n, 0));}struct hostent *gethostbyaddr(addr, len, type)	const char *addr;	int len, type;{	int n;	querybuf_t buf;	register struct hostent *hp;	char qbuf[MAXDNAME];		if (type != AF_INET)		return ((struct hostent *) NULL);	(void)sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa",		((unsigned)addr[3] & 0xff),		((unsigned)addr[2] & 0xff),		((unsigned)addr[1] & 0xff),		((unsigned)addr[0] & 0xff));	n = res_query(qbuf, C_IN, T_PTR, (u8_t *)&buf, sizeof(buf));	if (n < 0) {#ifdef DEBUG		if (_res.options & RES_DEBUG)			printf("res_query failed\n");#endif		return ((struct hostent *) NULL);	}	hp = getanswer(&buf, n, 1);	if (hp == NULL)		return ((struct hostent *) NULL);	hp->h_addrtype = type;	hp->h_length = len;	h_addr_ptrs[0] = (char *)&host_addr;	h_addr_ptrs[1] = (char *)0;	host_addr = *(struct in_addr *)addr;#if BSD < 43 && !defined(h_addr)	/* new-style hostent structure */	hp->h_addr = h_addr_ptrs[0];#endif	return(hp);}