OpenSolaris Launch

1 files changed, 472 insertions, 0 deletions

diff --git a/usr/src/lib/libresolv/res_gethost.c b/usr/src/lib/libresolv/res_gethost.c
new file mode 100644
index 0000000000..9e20672a14
--- /dev/null
+++ b/usr/src/lib/libresolv/res_gethost.c
@@ -0,0 +1,472 @@
+/*
+ * 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 this notice is preserved and that due credit is given
+ * to the University of California at Berkeley. The name of the University
+ * may not be used to endorse or promote products derived from this
+ * software without specific prior written permission. This software
+ * is provided ``as is'' without express or implied warranty.
+ *
+ */
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI" /* SunOS 1.11; UCB 6.32 */
+
+#include "synonyms.h"
+
+#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>
+#include <syslog.h>
+
+/*
+ * When the name service switch calls libresolv, it doesn't want fallback
+ * to /etc/hosts, so we provide a method to turn it off.
+ */
+static int	no_hosts_fallback = 0;
+
+void
+__res_set_no_hosts_fallback(void) {
+	no_hosts_fallback = 1;
+}
+
+static int
+__res_no_hosts_fallback(void) {
+	return(no_hosts_fallback);
+}
+
+static char *h_addr_ptrs[MAXADDRS + 1];
+
+static struct hostent host;
+static char *host_aliases[MAXALIASES];
+static char hostbuf[BUFSIZ+1];
+static struct in_addr host_addr;
+static char HOSTDB[] = "/etc/hosts";
+static FILE *hostf = NULL;
+static char hostaddr[MAXADDRS];
+static char *host_addrs[2];
+static int stayopen = 0;
+static char *any();
+
+#if PACKETSZ > 1024
+#define	MAXPACKET	PACKETSZ
+#else
+#define	MAXPACKET	1024
+#endif
+
+typedef union {
+	HEADER hdr;
+	u_char buf[MAXPACKET];
+} querybuf;
+
+static union {
+	long al;
+	char ac;
+} align;
+
+
+int h_errno;
+
+static struct hostent *
+getanswer(answer, anslen, iquery)
+	querybuf *answer;
+	int anslen;
+	int iquery;
+{
+	register HEADER *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->ancount);
+	qdcount = ntohs(hp->qdcount);
+	bp = hostbuf;
+	buflen = sizeof (hostbuf);
+	cp = answer->buf + sizeof (HEADER);
+	if (qdcount) {
+		if (iquery) {
+			if ((n = dn_expand((char *)answer->buf, eom,
+						cp, 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->aa)
+			h_errno = HOST_NOT_FOUND;
+		else
+			h_errno = TRY_AGAIN;
+		return ((struct hostent *) NULL);
+	}
+	ap = host_aliases;
+	host.h_aliases = host_aliases;
+	hap = h_addr_ptrs;
+#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 && haveanswer < MAXADDRS) {
+		if ((n = dn_expand((char *)answer->buf, eom,
+						cp, 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((char *)answer->buf, eom,
+					cp, 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 += sizeof (align) - ((u_long)bp % sizeof (align));
+
+		if (bp + n >= &hostbuf[sizeof (hostbuf)]) {
+#ifdef DEBUG
+			if (_res.options & RES_DEBUG)
+				printf("size (%d) too big\n", n);
+#endif
+			break;
+		}
+#ifdef SYSV
+		memcpy((void *)(*hap++ = bp), (void *)cp, n);
+#else
+		bcopy(cp, *hap++ = bp, n);
+#endif
+		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 *
+res_gethostbyname(name)
+	char *name;
+{
+	querybuf buf;
+	register char *cp;
+	int n;
+	struct hostent *hp, *gethostdomain();
+	static struct hostent *_gethtbyname();
+
+	/*
+	 * disallow names consisting only of digits/dots, unless
+	 * they end in a dot.
+	 */
+	if (isdigit(name[0]))
+		for (cp = name; /*EMPTY*/; ++cp) {
+			if (!*cp) {
+				if (*--cp == '.')
+					break;
+				h_errno = HOST_NOT_FOUND;
+				return ((struct hostent *) NULL);
+			}
+			if (!isdigit(*cp) && *cp != '.')
+				break;
+		}
+
+	if ((n = res_search(name, C_IN, T_A, buf.buf, sizeof (buf))) < 0) {
+#ifdef DEBUG
+		if (_res.options & RES_DEBUG)
+			printf("res_search failed\n");
+#endif
+		if (errno == ECONNREFUSED)
+			return (_gethtbyname(name));
+		else
+			return ((struct hostent *) NULL);
+	}
+	return (getanswer(&buf, n, 0));
+}
+
+static struct hostent *
+_getrhbyaddr(addr, len, type)
+	char *addr;
+	int len, type;
+{
+	int n;
+	querybuf buf;
+	register struct hostent *hp;
+	char qbuf[MAXDNAME];
+	static struct hostent *_gethtbyaddr();
+
+	if (type != AF_INET)
+		return ((struct hostent *) NULL);
+	(void) sprintf(qbuf, "%d.%d.%d.%d.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, (char *)&buf, sizeof (buf));
+	if (n < 0) {
+#ifdef DEBUG
+		if (_res.options & RES_DEBUG)
+			printf("res_query failed\n");
+#endif
+		if (errno == ECONNREFUSED)
+			return (_gethtbyaddr(addr, len, type));
+		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;
+	return (hp);
+}
+
+/*
+ * First we get what the PTR record says, but do an extra call
+ * to gethostbyname() to make sure that someone is not trying to
+ * spoof us.  Hopefully this is not done that often, so good
+ * performance is not really an issue.
+ */
+struct hostent *
+res_gethostbyaddr(addr, len, type)
+	char	*addr;
+	int	len;
+	int	type;
+{
+	char		**a, hbuf[MAXHOSTNAMELEN];
+	struct hostent	*hp, *hp2;
+
+	if ((hp = _getrhbyaddr(addr, len, type)) == (struct hostent *)NULL)
+		return ((struct hostent *)NULL);
+
+	/* hang on to what we got as an answer */
+	(void) strcpy(hbuf, hp->h_name);
+
+	/* check to make sure by doing a forward query */
+	if ((hp2 = res_gethostbyname(hbuf)) != (struct hostent *)NULL)
+		for (a = hp2->h_addr_list; *a; a++)
+#ifdef SYSV
+			if (memcmp(*a, addr, hp2->h_length) == 0)
+#else
+			if (bcmp(*a, addr, hp2->h_length) == 0)
+#endif
+				return (hp2);
+
+	/*
+	 * we've been spoofed, make sure to log it.
+	 * XXX - syslog needs a security priority level.
+	 */
+	syslog(LOG_NOTICE, "gethostbyaddr: %s != %s", hbuf,
+		inet_ntoa(*(struct in_addr *)addr));
+	return ((struct hostent *)NULL);
+}
+
+static
+_sethtent(f)
+	int f;
+{
+	if (__res_no_hosts_fallback()) return(0);
+
+	if (hostf == NULL)
+		hostf = fopen(HOSTDB, "r");
+	else
+		rewind(hostf);
+	stayopen |= f;
+}
+
+static
+_endhtent()
+{
+	if (__res_no_hosts_fallback()) return(0);
+
+	if (hostf && !stayopen) {
+		(void) fclose(hostf);
+		hostf = NULL;
+	}
+}
+
+static struct hostent *
+_gethtent()
+{
+	char *p;
+	register char *cp, **q;
+
+	if (__res_no_hosts_fallback()) return(NULL);
+
+	if (hostf == NULL && (hostf = fopen(HOSTDB, "r")) == NULL)
+		return (NULL);
+again:
+	if ((p = fgets(hostbuf, BUFSIZ, hostf)) == NULL)
+		return (NULL);
+	if (*p == '#')
+		goto again;
+	cp = any(p, "#\n");
+	if (cp == NULL)
+		goto again;
+	*cp = '\0';
+	cp = any(p, " \t");
+	if (cp == NULL)
+		goto again;
+	*cp++ = '\0';
+	/* THIS STUFF IS INTERNET SPECIFIC */
+#if BSD >= 43 || defined(h_addr)	/* new-style hostent structure */
+	host.h_addr_list = host_addrs;
+#endif
+	host.h_addr = hostaddr;
+	*((u_long *)host.h_addr) = inet_addr(p);
+	host.h_length = sizeof (u_long);
+	host.h_addrtype = AF_INET;
+	while (*cp == ' ' || *cp == '\t')
+		cp++;
+	host.h_name = cp;
+	q = host.h_aliases = host_aliases;
+	cp = any(cp, " \t");
+	if (cp != NULL)
+		*cp++ = '\0';
+	while (cp && *cp) {
+		if (*cp == ' ' || *cp == '\t') {
+			cp++;
+			continue;
+		}
+		if (q < &host_aliases[MAXALIASES - 1])
+			*q++ = cp;
+		cp = any(cp, " \t");
+		if (cp != NULL)
+			*cp++ = '\0';
+	}
+	*q = NULL;
+	return (&host);
+}
+
+static char *
+any(cp, match)
+	register char *cp;
+	char *match;
+{
+	register char *mp, c;
+
+	while (c = *cp) {
+		for (mp = match; *mp; mp++)
+			if (*mp == c)
+				return (cp);
+		cp++;
+	}
+	return ((char *)0);
+}
+
+static struct hostent *
+_gethtbyname(name)
+	char *name;
+{
+	register struct hostent *p;
+	register char **cp;
+
+	_sethtent(0);
+	while (p = _gethtent()) {
+		if (strcasecmp(p->h_name, name) == 0)
+			break;
+		for (cp = p->h_aliases; *cp != 0; cp++)
+			if (strcasecmp(*cp, name) == 0)
+				goto found;
+	}
+found:
+	_endhtent();
+	return (p);
+}
+
+static struct hostent *
+_gethtbyaddr(addr, len, type)
+	char *addr;
+	int len, type;
+{
+	register struct hostent *p;
+
+	_sethtent(0);
+	while (p = _gethtent())
+#ifdef SYSV
+		if (p->h_addrtype == type && !memcmp(p->h_addr, addr, len))
+#else
+		if (p->h_addrtype == type && !bcmp(p->h_addr, addr, len))
+#endif
+			break;
+	_endhtent();
+	return (p);
+}