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authorRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
committerRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
commit28f540f45bbacd939bfd07f213bcad2bf730b1bf (patch)
tree15f07c4c43d635959c6afee96bde71fb1b3614ee /resolv/getnetnamadr.c
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initial import
Diffstat (limited to 'resolv/getnetnamadr.c')
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diff --git a/resolv/getnetnamadr.c b/resolv/getnetnamadr.c
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+/* Copyright (c) 1993 Carlos Leandro and Rui Salgueiro
+ *	Dep. Matematica Universidade de Coimbra, Portugal, Europe
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ */
+/*
+ * Copyright (c) 1983, 1993
+ *	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 the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, 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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. 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 BY THE REGENTS 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 REGENTS 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.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)getnetbyaddr.c	8.1 (Berkeley) 6/4/93";
+static char sccsid_[] = "from getnetnamadr.c	1.4 (Coimbra) 93/06/03";
+static char rcsid[] = "$Id$";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/param.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <arpa/nameser.h>
+
+#include <stdio.h>
+#include <netdb.h>
+#include <resolv.h>
+#include <ctype.h>
+#include <errno.h>
+#include <string.h>
+#include "conf/portability.h"
+
+extern int h_errno;
+
+#if defined(mips) && defined(SYSTYPE_BSD43)
+extern int errno;
+#endif
+
+struct netent *_getnetbyaddr __P((long net, int type));
+#if defined(sun)
+struct netent *_getnetbyname __P((char *name));
+#else
+struct netent *_getnetbyname __P((const char *name));
+#endif
+
+#define BYADDR 0
+#define BYNAME 1
+#define	MAXALIASES	35
+
+#if PACKETSZ > 1024
+#define	MAXPACKET	PACKETSZ
+#else
+#define	MAXPACKET	1024
+#endif
+
+typedef union {
+	HEADER	hdr;
+	u_char	buf[MAXPACKET];
+} querybuf;
+
+typedef union {
+	long	al;
+	char	ac;
+} align;
+
+static struct netent *
+getnetanswer(answer, anslen, net_i)
+	querybuf *answer;
+	int anslen;
+	int net_i;
+{
+
+	register HEADER *hp;
+	register u_char *cp;
+	register int n;
+	u_char *eom;
+	int type, class, buflen, ancount, qdcount, haveanswer, i, nchar,
+		getclass = C_ANY, net_length = 0;
+	char aux1[30], aux2[30], ans[30], *in, *st, *pauxt, *bp, **ap,
+		*paux1 = &aux1[0], *paux2 = &aux2[0], flag = 0;
+static	struct netent net_entry;
+static	char *net_aliases[MAXALIASES], netbuf[BUFSIZ+1];
+
+	/*
+	 * find first satisfactory answer
+	 *
+	 *      answer --> +------------+  ( MESSAGE )
+	 *		   |   Header   |
+	 *		   +------------+
+	 *		   |  Question  | the question for the name server
+	 *		   +------------+
+	 *		   |   Answer   | RRs answering the question
+	 *		   +------------+
+	 *		   | Authority  | RRs pointing toward an authority
+	 *		   | Additional | RRs holding additional information
+	 *		   +------------+
+	 */
+	eom = answer->buf + anslen;
+	hp = &answer->hdr;
+	ancount = ntohs(hp->ancount); /* #/records in the answer section */
+	qdcount = ntohs(hp->qdcount); /* #/entries in the question section */
+	bp = netbuf;
+	buflen = sizeof(netbuf);
+	cp = answer->buf + HFIXEDSZ;
+	if (!qdcount) {
+		if (hp->aa)
+			h_errno = HOST_NOT_FOUND;
+		else
+			h_errno = TRY_AGAIN;
+		return (NULL);
+	}
+	while (qdcount-- > 0)
+		cp += __dn_skipname(cp, eom) + QFIXEDSZ;
+	ap = net_aliases;
+	*ap = NULL;
+	net_entry.n_aliases = net_aliases;
+	haveanswer = 0;
+	while (--ancount >= 0 && cp < eom) {
+		n = dn_expand(answer->buf, eom, cp, bp, buflen);
+		if (n < 0)
+			break;
+		cp += n;
+		ans[0] = '\0';
+		(void)strcpy(&ans[0], bp);
+		GETSHORT(type, cp);
+		GETSHORT(class, cp);
+		cp += INT32SZ;		/* TTL */
+		GETSHORT(n, cp);
+		if (class == C_IN && type == T_PTR) {
+			n = dn_expand(answer->buf, eom, cp, bp, buflen);
+			if (n < 0) {
+				cp += n;
+				return (NULL);
+			}
+			cp += n; 
+			*ap++ = bp;
+			bp += strlen(bp) + 1;
+			net_entry.n_addrtype =
+				(class == C_IN) ? AF_INET : AF_UNSPEC;
+			haveanswer++;
+		}
+	}
+	if (haveanswer) {
+		*ap = NULL;
+		switch (net_i) {
+		case BYADDR:
+			net_entry.n_name = *net_entry.n_aliases;
+			net_entry.n_net = 0L;
+			break;
+		case BYNAME:
+			in = *net_entry.n_aliases;
+			net_entry.n_name = &ans[0];
+			aux2[0] = '\0';
+			for (i = 0; i < 4; i++) {
+				for (st = in, nchar = 0;
+				     *st != '.';
+				     st++, nchar++)
+					;
+				if (nchar != 1 || *in != '0' || flag) {
+					flag = 1;
+					(void)strncpy(paux1,
+						      (i==0) ? in : in-1,
+						      (i==0) ?nchar : nchar+1);
+					paux1[(i==0) ? nchar : nchar+1] = '\0';
+					pauxt = paux2;
+					paux2 = strcat(paux1, paux2);
+					paux1 = pauxt;
+				}
+				in = ++st;
+			}		  
+			net_entry.n_net = inet_network(paux2);
+			break;
+		}
+		net_entry.n_aliases++;
+		return (&net_entry);
+	}
+	h_errno = TRY_AGAIN;
+	return (NULL);
+}
+
+struct netent *
+getnetbyaddr(net, net_type)
+	register long net;
+	register int net_type;
+{
+	unsigned int netbr[4];
+	int nn, anslen;
+	querybuf buf;
+	char qbuf[MAXDNAME];
+	unsigned long net2;
+	struct netent *net_entry;
+
+	if (net_type != AF_INET)
+		return (_getnetbyaddr(net, net_type));
+
+	for (nn = 4, net2 = net; net2; net2 >>= 8)
+		netbr[--nn] = net2 & 0xff;
+	switch (nn) {
+	case 3: 	/* Class A */
+		sprintf(qbuf, "0.0.0.%u.in-addr.arpa", netbr[3]);
+		break;
+	case 2: 	/* Class B */
+		sprintf(qbuf, "0.0.%u.%u.in-addr.arpa", netbr[3], netbr[2]);
+		break;
+	case 1: 	/* Class C */
+		sprintf(qbuf, "0.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2],
+		    netbr[1]);
+		break;
+	case 0: 	/* Class D - E */
+		sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2],
+		    netbr[1], netbr[0]);
+		break;
+	}
+	anslen = res_query(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf));
+	if (anslen < 0) {
+#ifdef DEBUG
+		if (_res.options & RES_DEBUG)
+			printf("res_query failed\n");
+#endif
+		if (errno == ECONNREFUSED)
+			return (_getnetbyaddr(net, net_type));
+		return (NULL);
+	}
+	net_entry = getnetanswer(&buf, anslen, BYADDR);
+	if (net_entry) {
+		unsigned u_net = net;	/* maybe net should be unsigned ? */
+
+		/* Strip trailing zeros */
+		while ((u_net & 0xff) == 0 && u_net != 0)
+			u_net >>= 8;
+		net_entry->n_net = u_net;
+		return (net_entry);
+	}
+	return (_getnetbyaddr(net, net_type));
+}
+
+struct netent *
+getnetbyname(net)
+#if defined(sun)
+	register char *net;
+#else
+	register const char *net;
+#endif
+{
+	unsigned int netbr[4];
+	int anslen;
+	querybuf buf;
+	char qbuf[MAXDNAME];
+	struct netent *net_entry;
+
+	strcpy(&qbuf[0],net);
+	anslen = res_search(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf));
+	if (anslen < 0) {
+#ifdef DEBUG
+		if (_res.options & RES_DEBUG)
+			printf("res_query failed\n");
+#endif
+		if (errno == ECONNREFUSED)
+			return (_getnetbyname(net));
+		return (_getnetbyname(net));
+	}
+	net_entry = getnetanswer(&buf, anslen, BYNAME);
+	if (net_entry)
+		return (net_entry);
+	return (_getnetbyname(net));
+}