diff --git a/libc/upstream-netbsd/lib/libc/include/resolv_mt.h b/libc/upstream-netbsd/lib/libc/include/resolv_mt.h
new file mode 100644
index 0000000..73a8dcc
--- /dev/null
+++ b/libc/upstream-netbsd/lib/libc/include/resolv_mt.h
@@ -0,0 +1,49 @@
+/*	$NetBSD: resolv_mt.h,v 1.1.1.3 2009/04/12 16:35:44 christos Exp $	*/
+
+#ifndef _RESOLV_MT_H
+#define _RESOLV_MT_H
+
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+#include <resolv.h>
+
+/* Access functions for the libresolv private interface */
+
+int	__res_enable_mt(void);
+int	__res_disable_mt(void);
+
+/* Per-thread context */
+
+typedef struct {
+int	no_hosts_fallback_private;
+int	retry_save;
+int	retry_private;
+char	inet_nsap_ntoa_tmpbuf[255*3];
+char	sym_ntos_unname[20];
+char	sym_ntop_unname[20];
+char	p_option_nbuf[40];
+char	p_time_nbuf[40];
+char	precsize_ntoa_retbuf[sizeof "90000000.00"];
+char	loc_ntoa_tmpbuf[sizeof
+"1000 60 60.000 N 1000 60 60.000 W -12345678.00m 90000000.00m 90000000.00m 90000000.00m"];
+char	p_secstodate_output[15];
+} mtctxres_t;
+
+/* Thread-specific data (TSD) */
+
+mtctxres_t	*___mtctxres(void);
+#define mtctxres	(___mtctxres())
+
+/* Various static data that should be TSD */
+
+#define sym_ntos_unname		(mtctxres->sym_ntos_unname)
+#define sym_ntop_unname		(mtctxres->sym_ntop_unname)
+#define inet_nsap_ntoa_tmpbuf	(mtctxres->inet_nsap_ntoa_tmpbuf)
+#define p_option_nbuf		(mtctxres->p_option_nbuf)
+#define p_time_nbuf		(mtctxres->p_time_nbuf)
+#define precsize_ntoa_retbuf	(mtctxres->precsize_ntoa_retbuf)
+#define loc_ntoa_tmpbuf		(mtctxres->loc_ntoa_tmpbuf)
+#define p_secstodate_output	(mtctxres->p_secstodate_output)
+
+#endif /* _RESOLV_MT_H */
diff --git a/libc/upstream-netbsd/lib/libc/inet/nsap_addr.c b/libc/upstream-netbsd/lib/libc/inet/nsap_addr.c
new file mode 100644
index 0000000..8633205
--- /dev/null
+++ b/libc/upstream-netbsd/lib/libc/inet/nsap_addr.c
@@ -0,0 +1,130 @@
+/*	$NetBSD: nsap_addr.c,v 1.6 2009/04/12 17:07:17 christos Exp $	*/
+
+/*
+ * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (c) 1996-1999 by Internet Software Consortium.
+ *
+ * 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.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+ * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/cdefs.h>
+#if defined(LIBC_SCCS) && !defined(lint)
+#if 0
+static const char rcsid[] = "Id: nsap_addr.c,v 1.5 2005/07/28 06:51:48 marka Exp";
+#else
+__RCSID("$NetBSD: nsap_addr.c,v 1.6 2009/04/12 17:07:17 christos Exp $");
+#endif
+#endif /* LIBC_SCCS and not lint */
+
+#include "port_before.h"
+
+#include "namespace.h"
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/socket.h>
+
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <arpa/nameser.h>
+
+#include <assert.h>
+#include <ctype.h>
+#include <resolv.h>
+#include <resolv_mt.h>
+
+#include "port_after.h"
+
+#ifdef __weak_alias
+__weak_alias(inet_nsap_addr,_inet_nsap_addr)
+__weak_alias(inet_nsap_ntoa,_inet_nsap_ntoa)
+#endif
+
+static char
+xtob(int c) {
+	return (c - (((c >= '0') && (c <= '9')) ? '0' : '7'));
+}
+
+u_int
+inet_nsap_addr(const char *ascii, u_char *binary, int maxlen) {
+	u_char c, nib;
+	u_int len = 0;
+
+	_DIAGASSERT(ascii != NULL);
+	_DIAGASSERT(binary != NULL);
+
+	if (ascii[0] != '0' || (ascii[1] != 'x' && ascii[1] != 'X'))
+		return (0);
+	ascii += 2;
+
+	while ((c = *ascii++) != '\0' && len < (u_int)maxlen) {
+		if (c == '.' || c == '+' || c == '/')
+			continue;
+		if (!isascii(c))
+			return (0);
+		if (islower(c))
+			c = toupper(c);
+		if (isxdigit(c)) {
+			nib = xtob(c);
+			c = *ascii++;
+			if (c != '\0') {
+				c = toupper(c);
+				if (isxdigit(c)) {
+					*binary++ = (nib << 4) | xtob(c);
+					len++;
+				} else
+					return (0);
+			}
+			else
+				return (0);
+		}
+		else
+			return (0);
+	}
+	return (len);
+}
+
+char *
+inet_nsap_ntoa(int binlen, const u_char *binary, char *ascii) {
+	int nib;
+	int i;
+	char *tmpbuf = inet_nsap_ntoa_tmpbuf;
+	char *start;
+
+	_DIAGASSERT(binary != NULL);
+
+	if (ascii)
+		start = ascii;
+	else {
+		ascii = tmpbuf;
+		start = tmpbuf;
+	}
+
+	*ascii++ = '0';
+	*ascii++ = 'x';
+
+	if (binlen > 255)
+		binlen = 255;
+
+	for (i = 0; i < binlen; i++) {
+		nib = (u_int32_t)*binary >> 4;
+		*ascii++ = nib + (nib < 10 ? '0' : '7');
+		nib = *binary++ & 0x0f;
+		*ascii++ = nib + (nib < 10 ? '0' : '7');
+		if (((i % 2) == 0 && (i + 1) < binlen))
+			*ascii++ = '.';
+	}
+	*ascii = '\0';
+	return (start);
+}
+
+/*! \file */
diff --git a/libc/upstream-netbsd/lib/libc/resolv/mtctxres.c b/libc/upstream-netbsd/lib/libc/resolv/mtctxres.c
new file mode 100644
index 0000000..6e3281a
--- /dev/null
+++ b/libc/upstream-netbsd/lib/libc/resolv/mtctxres.c
@@ -0,0 +1,130 @@
+/*	$NetBSD: mtctxres.c,v 1.4 2007/03/30 20:40:52 ghen Exp $	*/
+
+#include <port_before.h>
+#ifdef DO_PTHREADS
+#include <pthread.h>
+#endif
+#include <errno.h>
+#include <netdb.h>
+#include <stdlib.h>
+#include <string.h>
+#include <resolv_mt.h>
+#include <port_after.h>
+
+#ifdef DO_PTHREADS
+static pthread_key_t	key;
+static int		mt_key_initialized = 0;
+
+static int		__res_init_ctx(void);
+static void		__res_destroy_ctx(void *);
+
+#if defined(sun) && !defined(__GNUC__)
+#pragma init	(_mtctxres_init)
+#endif
+#endif
+
+static mtctxres_t	sharedctx;
+
+#ifdef DO_PTHREADS
+/*
+ * Initialize the TSD key. By doing this at library load time, we're
+ * implicitly running without interference from other threads, so there's
+ * no need for locking.
+ */
+static void
+_mtctxres_init(void) {
+	int pthread_keycreate_ret;
+
+	pthread_keycreate_ret = pthread_key_create(&key, __res_destroy_ctx);
+	if (pthread_keycreate_ret == 0)
+		mt_key_initialized = 1;
+}
+#endif
+
+/*
+ * To support binaries that used the private MT-safe interface in
+ * Solaris 8, we still need to provide the __res_enable_mt()
+ * and __res_disable_mt() entry points. They're do-nothing routines.
+ */
+int
+__res_enable_mt(void) {
+	return (-1);
+}
+
+int
+__res_disable_mt(void) {
+	return (0);
+}
+
+#ifdef DO_PTHREADS
+static int
+__res_init_ctx(void) {
+
+	mtctxres_t	*mt;
+	int		ret;
+
+
+	if (pthread_getspecific(key) != 0) {
+		/* Already exists */
+		return (0);
+	}
+
+	if ((mt = malloc(sizeof (mtctxres_t))) == 0) {
+		errno = ENOMEM;
+		return (-1);
+	}
+
+	memset(mt, 0, sizeof (mtctxres_t));
+
+	if ((ret = pthread_setspecific(key, mt)) != 0) {
+		free(mt);
+		errno = ret;
+		return (-1);
+	}
+
+	return (0);
+}
+
+static void
+__res_destroy_ctx(void *value) {
+
+	mtctxres_t	*mt = (mtctxres_t *)value;
+
+	if (mt != 0)
+		free(mt);
+}
+#endif
+
+mtctxres_t *
+___mtctxres(void) {
+#ifdef DO_PTHREADS
+	mtctxres_t	*mt;
+
+	/*
+	 * This if clause should only be executed if we are linking
+	 * statically.  When linked dynamically _mtctxres_init() should
+	 * be called at binding time due the #pragma above.
+	 */
+	if (!mt_key_initialized) {
+		static pthread_mutex_t keylock = PTHREAD_MUTEX_INITIALIZER;
+                if (pthread_mutex_lock(&keylock) == 0) {
+			_mtctxres_init();
+			(void) pthread_mutex_unlock(&keylock);
+		}
+	}
+
+	/*
+	 * If we have already been called in this thread return the existing
+	 * context.  Otherwise recreat a new context and return it.  If
+	 * that fails return a global context.
+	 */
+	if (mt_key_initialized) {
+		if (((mt = pthread_getspecific(key)) != 0) ||
+		    (__res_init_ctx() == 0 &&
+		     (mt = pthread_getspecific(key)) != 0)) {
+			return (mt);
+		}
+	}
+#endif
+	return (&sharedctx);
+}