5 files changed, 152 insertions, 70 deletions

diff --git a/lib/libc/net/getaddrinfo.c b/lib/libc/net/getaddrinfo.c
index 7847cd31d6c3..ed46d3f4bf57 100644
--- a/lib/libc/net/getaddrinfo.c
+++ b/lib/libc/net/getaddrinfo.c
@@ -182,11 +182,7 @@ static const struct explore explore[] = {
 #define	PTON_MAX	4
 #endif
 
-#if PACKETSZ > 1024
-#define MAXPACKET	PACKETSZ
-#else
-#define MAXPACKET	1024
-#endif
+#define MAXPACKET	(64*1024)
 
 typedef union {
 	HEADER hdr;
@@ -1407,7 +1403,7 @@ _dns_getaddrinfo(pai, hostname, res)
 	struct addrinfo **res;
 {
 	struct addrinfo *ai;
-	querybuf buf, buf2;
+	querybuf *buf, *buf2;
 	const char *name;
 	struct addrinfo sentinel, *cur;
 	struct res_target q, q2;
@@ -1417,47 +1413,66 @@ _dns_getaddrinfo(pai, hostname, res)
 	memset(&sentinel, 0, sizeof(sentinel));
 	cur = &sentinel;
 
+	buf = malloc(sizeof(*buf));
+	if (!buf) {
+		h_errno = NETDB_INTERNAL;
+		return EAI_MEMORY;
+	}
+	buf2 = malloc(sizeof(*buf2));
+	if (!buf2) {
+		free(buf);
+		h_errno = NETDB_INTERNAL;
+		return EAI_MEMORY;
+	}
+
 	switch (pai->ai_family) {
 	case AF_UNSPEC:
 		/* prefer IPv6 */
 		q.qclass = C_IN;
 		q.qtype = T_AAAA;
-		q.answer = buf.buf;
-		q.anslen = sizeof(buf);
+		q.answer = buf->buf;
+		q.anslen = sizeof(buf->buf);
 		q.next = &q2;
 		q2.qclass = C_IN;
 		q2.qtype = T_A;
-		q2.answer = buf2.buf;
-		q2.anslen = sizeof(buf2);
+		q2.answer = buf2->buf;
+		q2.anslen = sizeof(buf2->buf);
 		break;
 	case AF_INET:
 		q.qclass = C_IN;
 		q.qtype = T_A;
-		q.answer = buf.buf;
-		q.anslen = sizeof(buf);
+		q.answer = buf->buf;
+		q.anslen = sizeof(buf->buf);
 		break;
 	case AF_INET6:
 		q.qclass = C_IN;
 		q.qtype = T_AAAA;
-		q.answer = buf.buf;
-		q.anslen = sizeof(buf);
+		q.answer = buf->buf;
+		q.anslen = sizeof(buf->buf);
 		break;
 	default:
+		free(buf);
+		free(buf2);
 		return EAI_FAIL;
 	}
-	if (res_searchN(hostname, &q) < 0)
+	if (res_searchN(hostname, &q) < 0) {
+		free(buf);
+		free(buf2);
 		return EAI_NODATA;
-	ai = getanswer(&buf, q.n, q.name, q.qtype, pai);
+	}
+	ai = getanswer(buf, q.n, q.name, q.qtype, pai);
 	if (ai) {
 		cur->ai_next = ai;
 		while (cur && cur->ai_next)
 			cur = cur->ai_next;
 	}
 	if (q.next) {
-		ai = getanswer(&buf2, q2.n, q2.name, q2.qtype, pai);
+		ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai);
 		if (ai)
 			cur->ai_next = ai;
 	}
+	free(buf);
+	free(buf2);
 	if (sentinel.ai_next == NULL)
 		switch (h_errno) {
 		case HOST_NOT_FOUND:
@@ -1662,7 +1677,7 @@ res_queryN(name, target)
 	const char *name;	/* domain name */
 	struct res_target *target;
 {
-	u_char buf[MAXPACKET];
+	u_char *buf;
 	HEADER *hp;
 	int n;
 	struct res_target *t;
@@ -1677,6 +1692,12 @@ res_queryN(name, target)
 		return (-1);
 	}
 
+	buf = malloc(MAXPACKET);
+	if (!buf) {
+		h_errno = NETDB_INTERNAL;
+		return (-1);
+	}
+
 	for (t = target; t; t = t->next) {
 		int class, type;
 		u_char *answer;
@@ -1696,14 +1717,15 @@ res_queryN(name, target)
 #endif
 
 		n = res_mkquery(QUERY, name, class, type, NULL, 0, NULL,
-		    buf, sizeof(buf));
+		    buf, MAXPACKET);
 		if (n > 0 && (_res.options & RES_USE_EDNS0) != 0)
-			n = res_opt(n, buf, sizeof(buf), anslen);
+			n = res_opt(n, buf, MAXPACKET, anslen);
 		if (n <= 0) {
 #ifdef DEBUG
 			if (_res.options & RES_DEBUG)
 				printf(";; res_query: mkquery failed\n");
 #endif
+			free(buf);
 			h_errno = NO_RECOVERY;
 			return (n);
 		}
@@ -1714,12 +1736,15 @@ res_queryN(name, target)
 			if (_res.options & RES_DEBUG)
 				printf(";; res_query: send error\n");
 #endif
+			free(buf);
 			h_errno = TRY_AGAIN;
 			return (n);
 		}
 #endif
 
-		if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) {
+		if (n < 0 || n > anslen)
+			hp->rcode = FORMERR; /* XXX not very informative */
+		if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) {
 			rcode = hp->rcode;	/* record most recent error */
 #ifdef DEBUG
 			if (_res.options & RES_DEBUG)
@@ -1734,6 +1759,8 @@ res_queryN(name, target)
 		t->n = n;
 	}
 
+	free(buf);
+
 	if (ancount == 0) {
 		switch (rcode) {
 		case NXDOMAIN:
diff --git a/lib/libc/net/gethostbydns.c b/lib/libc/net/gethostbydns.c
index 52ac91a041be..5df45eb7e747 100644
--- a/lib/libc/net/gethostbydns.c
+++ b/lib/libc/net/gethostbydns.c
@@ -67,6 +67,7 @@ static char rcsid[] = "$FreeBSD$";
 #include <arpa/nameser.h>
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
 #include <netdb.h>
@@ -96,11 +97,7 @@ static u_char host_addr[16];	/* IPv4 or IPv6 */
 static void addrsort __P((char **, int));
 #endif
 
-#if PACKETSZ > 1024
-#define	MAXPACKET	PACKETSZ
-#else
-#define	MAXPACKET	1024
-#endif
+#define MAXPACKET	(64*1024)
 
 typedef union {
     HEADER hdr;
@@ -480,10 +477,11 @@ _gethostbydnsname(name, af)
 	const char *name;
 	int af;
 {
-	querybuf buf;
+	querybuf *buf;
 	register const char *cp;
 	char *bp;
 	int n, size, type, len;
+	struct hostent *hp;
 
 	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 		h_errno = NETDB_INTERNAL;
@@ -584,11 +582,19 @@ _gethostbydnsname(name, af)
 				break;
 		}
 
-	if ((n = res_search(name, C_IN, type, buf.buf, sizeof(buf))) < 0) {
+	if ((buf = malloc(sizeof(*buf))) == NULL) {
+		h_errno = NETDB_INTERNAL;
+		return (NULL);
+	}
+	n = res_search(name, C_IN, type, buf->buf, sizeof(buf->buf));
+  	if (n < 0) {
+		free(buf);
 		dprintf("res_search failed (%d)\n", n);
 		return (NULL);
 	}
-	return (gethostanswer(&buf, n, name, type));
+	hp = gethostanswer(buf, n, name, type);
+	free(buf);
+	return (hp);
 }
 
 struct hostent *
@@ -600,7 +606,7 @@ _gethostbydnsaddr(addr, len, af)
 	static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff };
 	static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 };
 	int n, size;
-	querybuf buf;
+	querybuf *buf;
 	register struct hostent *hp;
 	char qbuf[MAXDNAME+1], *qp;
 #ifdef SUNSECURITY
@@ -660,17 +666,26 @@ _gethostbydnsaddr(addr, len, af)
 	default:
 		abort();
 	}
-	n = res_query(qbuf, C_IN, T_PTR, (u_char *)buf.buf, sizeof buf.buf);
+	if ((buf = malloc(sizeof(*buf))) == NULL) {
+		h_errno = NETDB_INTERNAL;
+		return (NULL);
+	}
+	n = res_query(qbuf, C_IN, T_PTR, (u_char *)buf->buf, sizeof buf->buf);
 	if (n < 0) {
+		free(buf);
 		dprintf("res_query failed (%d)\n", n);
 		return (NULL);
 	}
-	if (n > sizeof buf.buf) {
+	if (n > sizeof buf->buf) {
+		free(buf);
 		dprintf("static buffer is too small (%d)\n", n);
 		return (NULL);
 	}
-	if (!(hp = gethostanswer(&buf, n, qbuf, T_PTR)))
+	if (!(hp = gethostanswer(buf, n, qbuf, T_PTR))) {
+		free(buf);
 		return (NULL);	/* h_errno was set by gethostanswer() */
+	}
+	free(buf);
 #ifdef SUNSECURITY
 	if (af == AF_INET) {
 	    /*
diff --git a/lib/libc/net/getnetbydns.c b/lib/libc/net/getnetbydns.c
index e1a11d2e5d3a..5de46df9169f 100644
--- a/lib/libc/net/getnetbydns.c
+++ b/lib/libc/net/getnetbydns.c
@@ -70,6 +70,7 @@ static char rcsid[] = "$FreeBSD$";
 #include <arpa/nameser.h>
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <netdb.h>
 #include <resolv.h>
 #include <ctype.h>
@@ -85,11 +86,7 @@ extern int h_errno;
 #define BYNAME 1
 #define	MAXALIASES	35
 
-#if PACKETSZ > 1024
-#define	MAXPACKET	PACKETSZ
-#else
-#define	MAXPACKET	1024
-#endif
+#define MAXPACKET	(64*1024)
 
 typedef union {
 	HEADER	hdr;
@@ -226,7 +223,7 @@ _getnetbydnsaddr(net, net_type)
 {
 	unsigned int netbr[4];
 	int nn, anslen;
-	querybuf buf;
+	querybuf *buf;
 	char qbuf[MAXDNAME];
 	unsigned long net2;
 	struct netent *net_entry;
@@ -252,15 +249,21 @@ _getnetbydnsaddr(net, net_type)
 		    netbr[1], netbr[0]);
 		break;
 	}
-	anslen = res_query(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf));
+	if ((buf = malloc(sizeof(*buf))) == NULL) {
+		h_errno = NETDB_INTERNAL;
+		return (NULL);
+	}
+	anslen = res_query(qbuf, C_IN, T_PTR, (u_char *)buf, sizeof(*buf));
 	if (anslen < 0) {
+		free(buf);
 #ifdef DEBUG
 		if (_res.options & RES_DEBUG)
 			printf("res_query failed\n");
 #endif
 		return (NULL);
 	}
-	net_entry = getnetanswer(&buf, anslen, BYADDR);
+	net_entry = getnetanswer(buf, anslen, BYADDR);
+	free(buf);
 	if (net_entry) {
 		unsigned u_net = net;	/* maybe net should be unsigned ? */
 
@@ -278,24 +281,32 @@ _getnetbydnsname(net)
 	register const char *net;
 {
 	int anslen;
-	querybuf buf;
+	querybuf *buf;
 	char qbuf[MAXDNAME];
+	struct netent *net_entry;
 
 	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 		h_errno = NETDB_INTERNAL;
 		return (NULL);
 	}
+	if ((buf = malloc(sizeof(*buf))) == NULL) {
+		h_errno = NETDB_INTERNAL;
+		return (NULL);
+	}
 	strncpy(qbuf, net, sizeof(qbuf) - 1);
 	qbuf[sizeof(qbuf) - 1] = '\0';
-	anslen = res_search(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf));
+	anslen = res_search(qbuf, C_IN, T_PTR, (u_char *)buf, sizeof(*buf));
 	if (anslen < 0) {
+		free(buf);
 #ifdef DEBUG
 		if (_res.options & RES_DEBUG)
 			printf("res_query failed\n");
 #endif
 		return (NULL);
 	}
-	return getnetanswer(&buf, anslen, BYNAME);
+	net_entry = getnetanswer(buf, anslen, BYNAME);
+	free(buf);
+	return net_entry;
 }
 
 void
diff --git a/lib/libc/net/name6.c b/lib/libc/net/name6.c
index 401786811b50..070280a6c166 100644
--- a/lib/libc/net/name6.c
+++ b/lib/libc/net/name6.c
@@ -994,11 +994,7 @@ struct __res_type_list {
         int     rtl_type;
 };
 
-#if PACKETSZ > 1024
-#define	MAXPACKET	PACKETSZ
-#else
-#define	MAXPACKET	1024
-#endif
+#define	MAXPACKET	(64*1024)
 
 typedef union {
 	HEADER hdr;
@@ -1305,7 +1301,7 @@ _res_search_multi(name, rtl, errp)
 	int trailing_dot, ret, saved_herrno;
 	int got_nodata = 0, got_servfail = 0, tried_as_is = 0;
 	struct __res_type_list *rtl0 = rtl;
-	querybuf buf;
+	querybuf *buf;
 
 	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 		*errp = NETDB_INTERNAL;
@@ -1318,17 +1314,23 @@ _res_search_multi(name, rtl, errp)
 	if (cp > name && *--cp == '.')
 		trailing_dot++;
 
+	buf = malloc(sizeof(*buf));
+	if (buf == NULL) {
+		*errp = NETDB_INTERNAL;
+		return NULL;
+	}
+
 	/* If there aren't any dots, it could be a user-level alias */
 	if (!dots && (cp = hostalias(name)) != NULL) {
 		for(rtl = rtl0; rtl != NULL;
 		    rtl = SLIST_NEXT(rtl, rtl_entry)) {
-			ret = res_query(cp, C_IN, rtl->rtl_type, buf.buf,
-					     sizeof(buf.buf));
-			if (ret > 0) {
+			ret = res_query(cp, C_IN, rtl->rtl_type, buf->buf,
+					     sizeof(buf->buf));
+			if (ret > 0 && ret < sizeof(buf->buf)) {
 				hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA)
 				    ? AF_INET6 : AF_INET;
 				hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype);
-				hp = getanswer(&buf, ret, name, rtl->rtl_type,
+				hp = getanswer(buf, ret, name, rtl->rtl_type,
 						    &hpbuf, errp);
 				if (!hp)
 					continue;
@@ -1336,6 +1338,7 @@ _res_search_multi(name, rtl, errp)
 				hp0 = _hpmerge(hp0, hp, errp);
 			}
 		}
+		free(buf);
 		return (hp0);
 	}
 
@@ -1348,12 +1351,12 @@ _res_search_multi(name, rtl, errp)
 		for(rtl = rtl0; rtl != NULL;
 		    rtl = SLIST_NEXT(rtl, rtl_entry)) {
 			ret = res_querydomain(name, NULL, C_IN, rtl->rtl_type,
-					      buf.buf, sizeof(buf.buf));
-			if (ret > 0) {
+					      buf->buf, sizeof(buf->buf));
+			if (ret > 0 && ret < sizeof(buf->buf)) {
 				hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA)
 				    ? AF_INET6 : AF_INET;
 				hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype);
-				hp = getanswer(&buf, ret, name, rtl->rtl_type,
+				hp = getanswer(buf, ret, name, rtl->rtl_type,
 						    &hpbuf, errp);
 				if (!hp)
 					continue;
@@ -1361,8 +1364,10 @@ _res_search_multi(name, rtl, errp)
 				hp0 = _hpmerge(hp0, hp, errp);
 			}
 		}
-		if (hp0 != NULL)
+		if (hp0 != NULL) {
+			free(buf);
 			return (hp0);
+		}
 		saved_herrno = *errp;
 		tried_as_is++;
 	}
@@ -1385,12 +1390,12 @@ _res_search_multi(name, rtl, errp)
 			    rtl = SLIST_NEXT(rtl, rtl_entry)) {
 				ret = res_querydomain(name, *domain, C_IN,
 						      rtl->rtl_type,
-						      buf.buf, sizeof(buf.buf));
-				if (ret > 0) {
+						      buf->buf, sizeof(buf->buf));
+				if (ret > 0 && ret < sizeof(buf->buf)) {
 					hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA)
 					    ? AF_INET6 : AF_INET;
 					hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype);
-					hp = getanswer(&buf, ret, name,
+					hp = getanswer(buf, ret, name,
 					    rtl->rtl_type, &hpbuf, errp);
 					if (!hp)
 						continue;
@@ -1398,8 +1403,10 @@ _res_search_multi(name, rtl, errp)
 					hp0 = _hpmerge(hp0, hp, errp);
 				}
 			}
-			if (hp0 != NULL)
+			if (hp0 != NULL) {
+				free(buf);
 				return (hp0);
+			}
 
 			/*
 			 * If no server present, give up.
@@ -1415,6 +1422,7 @@ _res_search_multi(name, rtl, errp)
 			 * fully-qualified.
 			 */
 			if (errno == ECONNREFUSED) {
+				free(buf);
 				*errp = TRY_AGAIN;
 				return (NULL);
 			}
@@ -1427,7 +1435,7 @@ _res_search_multi(name, rtl, errp)
 				/* keep trying */
 				break;
 			case TRY_AGAIN:
-				if (buf.hdr.rcode == SERVFAIL) {
+				if (buf->hdr.rcode == SERVFAIL) {
 					/* try next search element, if any */
 					got_servfail++;
 					break;
@@ -1455,12 +1463,12 @@ _res_search_multi(name, rtl, errp)
 		for(rtl = rtl0; rtl != NULL;
 		    rtl = SLIST_NEXT(rtl, rtl_entry)) {
 			ret = res_querydomain(name, NULL, C_IN, rtl->rtl_type,
-					      buf.buf, sizeof(buf.buf));
-			if (ret > 0) {
+					      buf->buf, sizeof(buf->buf));
+			if (ret > 0 && ret < sizeof(buf->buf)) {
 				hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA)
 				    ? AF_INET6 : AF_INET;
 				hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype);
-				hp = getanswer(&buf, ret, name, rtl->rtl_type,
+				hp = getanswer(buf, ret, name, rtl->rtl_type,
 				    &hpbuf, errp);
 				if (!hp)
 					continue;
@@ -1468,10 +1476,14 @@ _res_search_multi(name, rtl, errp)
 				hp0 = _hpmerge(hp0, hp, errp);
 			}
 		}
-		if (hp0 != NULL)
+		if (hp0 != NULL) {
+			free(buf);
 			return (hp0);
+		}
 	}
 
+	free(buf);
+
 	/* if we got here, we didn't satisfy the search.
 	 * if we did an initial full query, return that query's h_errno
 	 * (note that we wouldn't be here if that query had succeeded).
@@ -1531,7 +1543,7 @@ _dns_ghbyaddr(const void *addr, int addrlen, int af, int *errp)
 #ifdef INET6
 	static const char hex[] = "0123456789abcdef";
 #endif
-	querybuf buf;
+	querybuf *buf;
 	char qbuf[MAXDNAME+1];
 	char *hlist[2];
 
@@ -1584,12 +1596,27 @@ _dns_ghbyaddr(const void *addr, int addrlen, int af, int *errp)
 		break;
 	}
 
-	n = res_query(qbuf, C_IN, T_PTR, buf.buf, sizeof buf.buf);
+	buf = malloc(sizeof(*buf));
+	if (buf == NULL) {
+		*errp = NETDB_INTERNAL;
+		return NULL;
+	}
+
+	n = res_query(qbuf, C_IN, T_PTR, buf->buf, sizeof buf->buf);
 	if (n < 0) {
+		free(buf);
 		*errp = h_errno;
 		return NULL;
+	} else if (n > sizeof(buf->buf)) {
+		free(buf);
+		*errp = NETDB_INTERNAL;
+#if 0
+		errno = ERANGE; /* XXX is it OK to set errno here? */
+#endif
+		return NULL;
 	}
-	hp = getanswer(&buf, n, qbuf, T_PTR, &hbuf, errp);
+	hp = getanswer(buf, n, qbuf, T_PTR, &hbuf, errp);
+	free(buf);
 	if (!hp)
 		return NULL;
 	hbuf.h_addrtype = af;
diff --git a/lib/libc/net/res_mkquery.c b/lib/libc/net/res_mkquery.c
index 6cbd37394b92..bacc4d58fe6b 100644
--- a/lib/libc/net/res_mkquery.c
+++ b/lib/libc/net/res_mkquery.c
@@ -228,6 +228,8 @@ res_opt(n0, buf, buflen, anslen)
 
 	__putshort(T_OPT, cp);	/* TYPE */
 	cp += INT16SZ;
+	if (anslen > 0xffff)
+		anslen = 0xffff;		/* limit to 16bit value */
 	__putshort(anslen & 0xffff, cp);	/* CLASS = UDP payload size */
 	cp += INT16SZ;
 	*cp++ = NOERROR;	/* extended RCODE */