From c4daf5eae5207fd6831b760cc004be1e46ca5339 Mon Sep 17 00:00:00 2001
From: christos <christos@NetBSD.org>
Date: Tue, 9 Jan 2018 01:53:55 +0000
Subject: [PATCH] add strndup and an alias to strdup.

---
 sys/kern/subr_kmem.c | 21 +++++++++++++++++++--
 sys/sys/kmem.h       |  4 +++-
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/sys/kern/subr_kmem.c b/sys/kern/subr_kmem.c
index 17b351402612..a1b35d719624 100644
--- a/sys/kern/subr_kmem.c
+++ b/sys/kern/subr_kmem.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: subr_kmem.c,v 1.65 2017/11/09 23:20:12 riastradh Exp $	*/
+/*	$NetBSD: subr_kmem.c,v 1.66 2018/01/09 01:53:55 christos Exp $	*/
 
 /*-
  * Copyright (c) 2009-2015 The NetBSD Foundation, Inc.
@@ -100,7 +100,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.65 2017/11/09 23:20:12 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.66 2018/01/09 01:53:55 christos Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_kmem.h"
@@ -544,6 +544,23 @@ kmem_strdupsize(const char *str, size_t *lenp, km_flag_t flags)
 	return ptr;
 }
 
+char *
+kmem_strndup(const char *str, size_t maxlen, km_flag_t flags)
+{
+	KASSERT(str != NULL);
+	KASSERT(maxlen != 0);
+
+	size_t len = strnlen(str, maxlen);
+	char *ptr = kmem_alloc(len + 1, flags);
+	if (ptr == NULL)
+		return NULL;
+
+	memcpy(ptr, str, len);
+	ptr[len] = '\0';
+
+	return ptr;
+}
+
 void
 kmem_strfree(char *str)
 {
diff --git a/sys/sys/kmem.h b/sys/sys/kmem.h
index 54b617f7c8ea..bf2efb4dc63a 100644
--- a/sys/sys/kmem.h
+++ b/sys/sys/kmem.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: kmem.h,v 1.10 2017/11/07 18:35:57 christos Exp $	*/
+/*	$NetBSD: kmem.h,v 1.11 2018/01/09 01:53:55 christos Exp $	*/
 
 /*-
  * Copyright (c)2006 YAMAMOTO Takashi,
@@ -47,6 +47,8 @@ void	kmem_intr_free(void *, size_t);
 char *	kmem_asprintf(const char *, ...) __printflike(1, 2);
 
 char *	kmem_strdupsize(const char *, size_t *, km_flag_t);
+#define kmem_strdup(s, f)	kmem_strdupsize((s), NULL, (f))
+char *	kmem_strndup(const char *, size_t, km_flag_t);
 void	kmem_strfree(char *);
 
 /*