Move compat out of src.

21 files changed, 1765 insertions, 0 deletions

diff --git a/compat/arc4random.c b/compat/arc4random.c
new file mode 100644
index 00000000..ab06df04
--- /dev/null
+++ b/compat/arc4random.c
@@ -0,0 +1,158 @@
+/*
+ * Arc4 random number generator for OpenBSD.
+ * Copyright 1996 David Mazieres <dm@lcs.mit.edu>.
+ *
+ * Modification and redistribution in source and binary forms is
+ * permitted provided that due credit is given to the author and the
+ * OpenBSD project by leaving this copyright notice intact.
+ */
+
+/*
+ * This code is derived from section 17.1 of Applied Cryptography,
+ * second edition, which describes a stream cipher allegedly
+ * compatible with RSA Labs "RC4" cipher (the actual description of
+ * which is a trade secret).  The same algorithm is used as a stream
+ * cipher called "arcfour" in Tatu Ylonen's ssh package.
+ *
+ * Here the stream cipher has been modified always to include the time
+ * when initializing the state.  That makes it impossible to
+ * regenerate the same random sequence twice, so this can't be used
+ * for encryption, but will generate good random numbers.
+ *
+ * RC4 is a registered trademark of RSA Laboratories.
+ */
+
+#include <sys/time.h>
+
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "arc4random.h"
+
+struct arc4_stream {
+	uint8_t i;
+	uint8_t j;
+	uint8_t s[256];
+	size_t count;
+	pid_t stir_pid;
+};
+
+#define S(n) (n)
+#define S4(n) S(n), S(n + 1), S(n + 2), S(n + 3)
+#define S16(n) S4(n), S4(n + 4), S4(n + 8), S4(n + 12)
+#define S64(n) S16(n), S16(n + 16), S16(n + 32), S16(n + 48)
+#define S256 S64(0), S64(64), S64(128), S64(192)
+
+static struct arc4_stream rs = { .i = 0xff, .j = 0, .s = { S256 },
+                    .count = 0, .stir_pid = 0 };
+
+#undef S
+#undef S4
+#undef S16
+#undef S64
+#undef S256
+
+static void
+arc4_addrandom(struct arc4_stream *as, unsigned char *dat, int datlen)
+{
+	int n;
+	uint8_t si;
+
+	as->i--;
+	for (n = 0; n < 256; n++) {
+		as->i = (uint8_t)(as->i + 1);
+		si = as->s[as->i];
+		as->j = (uint8_t)(as->j + si + dat[n % datlen]);
+		as->s[as->i] = as->s[as->j];
+		as->s[as->j] = si;
+	}
+	as->j = as->i;
+}
+
+static uint8_t
+arc4_getbyte(struct arc4_stream *as)
+{
+	uint8_t si, sj;
+
+	as->i = (uint8_t)(as->i + 1);
+	si = as->s[as->i];
+	as->j = (uint8_t)(as->j + si);
+	sj = as->s[as->j];
+	as->s[as->i] = sj;
+	as->s[as->j] = si;
+	return (as->s[(si + sj) & 0xff]);
+}
+
+static uint32_t
+arc4_getword(struct arc4_stream *as)
+{
+	int val;
+
+	val = arc4_getbyte(as) << 24;
+	val |= arc4_getbyte(as) << 16;
+	val |= arc4_getbyte(as) << 8;
+	val |= arc4_getbyte(as);
+	return (uint32_t)val;
+}
+
+/* We don't care about any error on read, just use what we have
+ * on the stack. So mask off this GCC warning. */
+#pragma GCC diagnostic ignored "-Wunused-result"
+static void
+arc4_stir(struct arc4_stream *as)
+{
+	int fd;
+	struct {
+		struct timeval tv;
+		unsigned int rnd[(128 - sizeof(struct timeval)) /
+			sizeof(unsigned int)];
+	}       rdat;
+	size_t n;
+
+	gettimeofday(&rdat.tv, NULL);
+	fd = open("/dev/urandom", O_RDONLY);
+	if (fd != -1) {
+		/* If there is an error reading, just use what is
+		 * on the stack. */
+		/* coverity[check_return] */
+		(void)read(fd, rdat.rnd, sizeof(rdat.rnd));
+		close(fd);
+	}
+
+	/* fd < 0?  Ah, what the heck. We'll just take
+	 * whatever was on the stack... */
+	/* coverity[uninit_use_in_call] */
+	arc4_addrandom(as, (void *) &rdat, sizeof(rdat));
+
+	/*
+	 * Throw away the first N words of output, as suggested in the
+	 * paper "Weaknesses in the Key Scheduling Algorithm of RC4"
+	 * by Fluher, Mantin, and Shamir.  (N = 256 in our case.)
+	 */
+	for (n = 0; n < 256 * sizeof(uint32_t); n++)
+		arc4_getbyte(as);
+	as->count = 1600000;
+}
+
+static void
+arc4_stir_if_needed(struct arc4_stream *as)
+{
+	pid_t pid;
+
+	pid = getpid();
+	if (as->count <= sizeof(uint32_t) || as->stir_pid != pid) {
+		as->stir_pid = pid;
+		arc4_stir(as);
+	} else
+		as->count -= sizeof(uint32_t);
+}
+
+uint32_t
+arc4random()
+{
+
+	arc4_stir_if_needed(&rs);
+	return arc4_getword(&rs);
+}
diff --git a/compat/arc4random.h b/compat/arc4random.h
new file mode 100644
index 00000000..d8ae3c78
--- /dev/null
+++ b/compat/arc4random.h
@@ -0,0 +1,34 @@
+/*
+ * dhcpcd - DHCP client daemon
+ * Copyright (c) 2006-2014 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#ifndef ARC4RANDOM_H
+#define ARC4RANDOM_H
+
+#include <stdint.h>
+
+uint32_t arc4random(void);
+#endif
diff --git a/compat/arc4random_uniform.c b/compat/arc4random_uniform.c
new file mode 100644
index 00000000..b5975512
--- /dev/null
+++ b/compat/arc4random_uniform.c
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2008, Damien Miller <djm@openbsd.org>
+ *
+ * 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 THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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 <stdint.h>
+#include <stdlib.h>
+
+/* We need to include config.h so we pickup either the system arc4random
+ * or our compat one. */
+#include "../config.h"
+
+/*
+ * Calculate a uniformly distributed random number less than upper_bound
+ * avoiding "modulo bias".
+ *
+ * Uniformity is achieved by generating new random numbers until the one
+ * returned is outside the range [0, 2**32 % upper_bound).  This
+ * guarantees the selected random number will be inside
+ * [2**32 % upper_bound, 2**32) which maps back to [0, upper_bound)
+ * after reduction modulo upper_bound.
+ */
+uint32_t
+arc4random_uniform(uint32_t upper_bound)
+{
+	uint32_t r, min;
+
+	if (upper_bound < 2)
+		return 0;
+
+	/* 2**32 % x == (2**32 - x) % x */
+	min = -upper_bound % upper_bound;
+
+	/*
+	 * This could theoretically loop forever but each retry has
+	 * p > 0.5 (worst case, usually far better) of selecting a
+	 * number inside the range we need, so it should rarely need
+	 * to re-roll.
+	 */
+	do
+		r = arc4random();
+	while (r < min);
+
+	return r % upper_bound;
+}
diff --git a/compat/arc4random_uniform.h b/compat/arc4random_uniform.h
new file mode 100644
index 00000000..e6a9b744
--- /dev/null
+++ b/compat/arc4random_uniform.h
@@ -0,0 +1,34 @@
+/*
+ * dhcpcd - DHCP client daemon
+ * Copyright (c) 2006-2014 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#ifndef ARC4RANDOM_UNIFORM_H
+#define ARC4RANDOM_UNIFORM_H
+
+#include <stdint.h>
+
+uint32_t arc4random_uniform(uint32_t);
+#endif
diff --git a/compat/bitops.h b/compat/bitops.h
new file mode 100644
index 00000000..d67fa848
--- /dev/null
+++ b/compat/bitops.h
@@ -0,0 +1,188 @@
+/*	$NetBSD: bitops.h,v 1.11 2012/12/07 02:27:58 christos Exp $	*/
+
+/*-
+ * Copyright (c) 2007, 2010 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Christos Zoulas and Joerg Sonnenberger.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
+ */
+
+#ifndef COMPAT_BITOPS_H
+#define COMPAT_BITOPS_H
+
+#include <stdint.h>
+#include "../common.h"
+
+/*
+ * Find First Set functions
+ */
+#ifndef ffs32
+static inline int __unused
+ffs32(uint32_t _n)
+{
+	int _v;
+
+	if (!_n)
+		return 0;
+
+	_v = 1;
+	if ((_n & 0x0000FFFFU) == 0) {
+		_n >>= 16;
+		_v += 16;
+	}
+	if ((_n & 0x000000FFU) == 0) {
+		_n >>= 8;
+		_v += 8;
+	}
+	if ((_n & 0x0000000FU) == 0) {
+		_n >>= 4;
+		_v += 4;
+	}
+	if ((_n & 0x00000003U) == 0) {
+		_n >>= 2;
+		_v += 2;
+	}
+	if ((_n & 0x00000001U) == 0) {
+		//_n >>= 1;
+		_v += 1;
+	}
+	return _v;
+}
+#endif
+
+#ifndef ffs64
+static inline int __unused
+ffs64(uint64_t _n)
+{
+	int _v;
+
+	if (!_n)
+		return 0;
+
+	_v = 1;
+	if ((_n & 0x00000000FFFFFFFFULL) == 0) {
+		_n >>= 32;
+		_v += 32;
+	}
+	if ((_n & 0x000000000000FFFFULL) == 0) {
+		_n >>= 16;
+		_v += 16;
+	}
+	if ((_n & 0x00000000000000FFULL) == 0) {
+		_n >>= 8;
+		_v += 8;
+	}
+	if ((_n & 0x000000000000000FULL) == 0) {
+		_n >>= 4;
+		_v += 4;
+	}
+	if ((_n & 0x0000000000000003ULL) == 0) {
+		_n >>= 2;
+		_v += 2;
+	}
+	if ((_n & 0x0000000000000001ULL) == 0) {
+		//_n >>= 1;
+		_v += 1;
+	}
+	return _v;
+}
+#endif
+
+/*
+ * Find Last Set functions
+ */
+#ifndef fls32
+static __inline int __unused
+fls32(uint32_t _n)
+{
+	int _v;
+
+	if (!_n)
+		return 0;
+
+	_v = 32;
+	if ((_n & 0xFFFF0000U) == 0) {
+		_n <<= 16;
+		_v -= 16;
+	}
+	if ((_n & 0xFF000000U) == 0) {
+		_n <<= 8;
+		_v -= 8;
+	}
+	if ((_n & 0xF0000000U) == 0) {
+		_n <<= 4;
+		_v -= 4;
+	}
+	if ((_n & 0xC0000000U) == 0) {
+		_n <<= 2;
+		_v -= 2;
+	}
+	if ((_n & 0x80000000U) == 0) {
+		//_n <<= 1;
+		_v -= 1;
+	}
+	return _v;
+}
+#endif
+
+#ifndef fls64
+static int __unused
+fls64(uint64_t _n)
+{
+	int _v;
+
+	if (!_n)
+		return 0;
+
+	_v = 64;
+	if ((_n & 0xFFFFFFFF00000000ULL) == 0) {
+		_n <<= 32;
+		_v -= 32;
+	}
+	if ((_n & 0xFFFF000000000000ULL) == 0) {
+		_n <<= 16;
+		_v -= 16;
+	}
+	if ((_n & 0xFF00000000000000ULL) == 0) {
+		_n <<= 8;
+		_v -= 8;
+	}
+	if ((_n & 0xF000000000000000ULL) == 0) {
+		_n <<= 4;
+		_v -= 4;
+	}
+	if ((_n & 0xC000000000000000ULL) == 0) {
+		_n <<= 2;
+		_v -= 2;
+	}
+	if ((_n & 0x8000000000000000ULL) == 0) {
+		//_n <<= 1;
+		_v -= 1;
+	}
+	return _v;
+}
+#endif
+
+#endif /* COMPAT_BITOPS_H_ */
diff --git a/compat/dprintf.c b/compat/dprintf.c
new file mode 100644
index 00000000..610a8f0b
--- /dev/null
+++ b/compat/dprintf.c
@@ -0,0 +1,65 @@
+/*
+ * dhcpcd - DHCP client daemon
+ * Copyright (c) 2006-2014 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <unistd.h>
+
+#include "dprintf.h"
+
+int
+vdprintf(int fd, const char * __restrict fmt, va_list va)
+{
+	int e;
+	FILE *fp;
+
+	if ((e = dup(fd)) == -1)
+		return -1;
+
+	if ((fp = fdopen(e, "w")) == NULL) {
+		close(e);
+		return -1;
+	}
+
+	e = vfprintf(fp, fmt, va);
+	fclose(fp);
+	return e;
+}
+
+int
+dprintf(int fd, const char * __restrict fmt, ...)
+{
+	int e;
+	va_list va;
+
+	va_start(va, fmt);
+	e = vdprintf(fd, fmt, va);
+	va_end(va);
+	return e;
+}
+
diff --git a/compat/dprintf.h b/compat/dprintf.h
new file mode 100644
index 00000000..b8cd4971
--- /dev/null
+++ b/compat/dprintf.h
@@ -0,0 +1,43 @@
+/*
+ * dhcpcd - DHCP client daemon
+ * Copyright (c) 2006-2014 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#ifndef DPRINTF_H
+#define DPRINTF_H
+
+#include <stdarg.h>
+
+#ifndef __printflike
+# if __GNUC__ > 2 || defined(__INTEL_COMPILER)
+#  define __printflike(a, b) __attribute__((format(printf, a, b)))
+# else
+#  define __printflike(a, b)
+# endif
+#endif
+
+__printflike(2, 0) int vdprintf(int, const char * __restrict, va_list);
+__printflike(2, 3) int dprintf(int, const char * __restrict, ...);
+#endif
diff --git a/compat/endian.h b/compat/endian.h
new file mode 100644
index 00000000..8d01738b
--- /dev/null
+++ b/compat/endian.h
@@ -0,0 +1,71 @@
+/*
+ * dhcpcd - DHCP client daemon
+ * Copyright (c) 2006-2014 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#ifndef ENDIAN_H
+#define ENDIAN_H
+
+#include <stdint.h>
+
+inline static void
+be32enc(uint8_t *buf, uint32_t u)
+{
+
+	buf[0] = (uint8_t)((u >> 24) & 0xff);
+	buf[1] = (uint8_t)((u >> 16) & 0xff);
+	buf[2] = (uint8_t)((u >> 8) & 0xff);
+	buf[3] = (uint8_t)(u & 0xff);
+}
+
+inline static void
+be64enc(uint8_t *buf, uint64_t u)
+{
+
+	be32enc(buf, (uint32_t)(u >> 32));
+	be32enc(buf + sizeof(uint32_t), (uint32_t)(u & 0xffffffffULL));
+}
+
+inline static uint16_t
+be16dec(const uint8_t *buf)
+{
+
+	return (uint16_t)(buf[0] << 8 | buf[1]);
+}
+
+inline static uint32_t
+be32dec(const uint8_t *buf)
+{
+
+	return (uint32_t)((uint32_t)be16dec(buf) << 16 | be16dec(buf + 2));
+}
+
+inline static uint64_t
+be64dec(const uint8_t *buf)
+{
+
+	return (uint64_t)((uint64_t)be32dec(buf) << 32 | be32dec(buf + 4));
+}
+#endif
diff --git a/compat/getline.c b/compat/getline.c
new file mode 100644
index 00000000..8c0cbdff
--- /dev/null
+++ b/compat/getline.c
@@ -0,0 +1,75 @@
+/*
+ * dhcpcd - DHCP client daemon
+ * Copyright (c) 2006-2009 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "getline.h"
+
+/* Redefine a small buffer for our simple text config files */
+#undef BUFSIZ
+#define BUFSIZ 128
+
+ssize_t
+getline(char ** __restrict buf, size_t * __restrict buflen,
+    FILE * __restrict fp)
+{
+	size_t bytes, newlen;
+	char *newbuf, *p;
+
+	if (buf == NULL || buflen == NULL) {
+		errno = EINVAL;
+		return -1;
+	}
+	if (*buf == NULL)
+		*buflen = 0;
+
+	bytes = 0;
+	do {
+		if (feof(fp))
+			break;
+		if (*buf == NULL || bytes != 0 || *buflen < BUFSIZ) {
+			newlen = *buflen + BUFSIZ;
+			newbuf = realloc(*buf, newlen);
+			if (newbuf == NULL)
+				return -1;
+			*buf = newbuf;
+			*buflen = newlen;
+		}
+		p = *buf + bytes;
+		memset(p, 0, BUFSIZ);
+		if (fgets(p, BUFSIZ, fp) == NULL)
+			break;
+		bytes += strlen(p);
+	} while (bytes == 0 || *(*buf + (bytes - 1)) != '\n');
+	if (bytes == 0)
+		return -1;
+	return bytes;
+}
diff --git a/compat/getline.h b/compat/getline.h
new file mode 100644
index 00000000..3db807a8
--- /dev/null
+++ b/compat/getline.h
@@ -0,0 +1,36 @@
+/*
+ * dhcpcd - DHCP client daemon
+ * Copyright (c) 2006-2009 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#ifndef GETLINE_H
+#define GETLINE_H
+
+#include <sys/types.h>
+#include <stdio.h>
+
+ssize_t getline(char ** __restrict buf, size_t * __restrict buflen,
+    FILE * __restrict fp);
+#endif
diff --git a/compat/pidfile.c b/compat/pidfile.c
new file mode 100644
index 00000000..20302c29
--- /dev/null
+++ b/compat/pidfile.c
@@ -0,0 +1,269 @@
+/*	$NetBSD: pidfile.c,v 1.14 2016/04/12 20:40:43 roy Exp $	*/
+
+/*-
+ * Copyright (c) 1999, 2016 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Jason R. Thorpe, Matthias Scheler, Julio Merino and Roy Marples.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
+ */
+
+#include <sys/param.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <paths.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sys/file.h>	/* for flock(2) */
+#include "../config.h"
+#include "../defs.h"
+
+static pid_t pidfile_pid;
+static char pidfile_path[PATH_MAX];
+static int pidfile_fd = -1;
+
+/* Closes pidfile resources.
+ *
+ * Returns 0 on success, otherwise -1. */
+static int
+pidfile_close(void)
+{
+	int error;
+
+	pidfile_pid = 0;
+	error = close(pidfile_fd);
+	pidfile_fd = -1;
+	pidfile_path[0] = '\0';
+	return error;
+}
+
+/* Truncate, close and unlink an existent pidfile,
+ * if and only if it was created by this process.
+ * The pidfile is truncated because we may have dropped permissions
+ * or entered a chroot and thus unable to unlink it.
+ *
+ * Returns 0 on truncation success, otherwise -1. */
+int
+pidfile_clean(void)
+{
+	int error;
+
+	if (pidfile_fd == -1) {
+		errno = EBADF;
+		return -1;
+	}
+
+	if (pidfile_pid != getpid())
+		error = EPERM;
+	else if (ftruncate(pidfile_fd, 0) == -1)
+		error = errno;
+	else {
+		(void) unlink(pidfile_path);
+		error = 0;
+	}
+
+	(void) pidfile_close();
+
+	if (error != 0) {
+		errno = error;
+		return -1;
+	}
+	return 0;
+}
+
+/* atexit shim for pidfile_clean */
+static void
+pidfile_cleanup(void)
+{
+
+	pidfile_clean();
+}
+
+/* Constructs a name for a pidfile in the default location (/var/run).
+ * If 'bname' is NULL, uses the name of the current program for the name of
+ * the pidfile.
+ *
+ * Returns 0 on success, otherwise -1. */
+static int
+pidfile_varrun_path(char *path, size_t len, const char *bname)
+{
+
+	if (bname == NULL)
+		bname = PACKAGE;
+
+	/* _PATH_VARRUN includes trailing / */
+	if ((size_t)snprintf(path, len, "%s%s.pid", _PATH_VARRUN, bname) >= len)
+	{
+		errno = ENAMETOOLONG;
+		return -1;
+	}
+	return 0;
+}
+
+/* Returns the process ID inside path on success, otherwise -1.
+ * If no path is given, use the last pidfile path, othewise the default one. */
+pid_t
+pidfile_read(const char *path)
+{
+	char dpath[PATH_MAX], buf[16], *eptr;
+	int fd, error;
+	ssize_t n;
+	pid_t pid;
+
+	if (path == NULL && pidfile_path[0] != '\0')
+		path = pidfile_path;
+	if (path == NULL || strchr(path, '/') == NULL) {
+		if (pidfile_varrun_path(dpath, sizeof(dpath), path) == -1)
+			return -1;
+		path = dpath;
+	}
+
+	if ((fd = open(path, O_RDONLY | O_NONBLOCK)) == -1)
+		return  -1;
+	n = read(fd, buf, sizeof(buf) - 1);
+	error = errno;
+	(void) close(fd);
+	if (n == -1) {
+		errno = error;
+		return -1;
+	}
+	buf[n] = '\0';
+	pid = (pid_t)strtoi(buf, &eptr, 10, 1, INT_MAX, &error);
+	if (error && !(error == ENOTSUP && *eptr == '\n')) {
+		errno = error;
+		return -1;
+	}
+	return pid;
+}
+
+/* Locks the pidfile specified by path and writes the process pid to it.
+ * The new pidfile is "registered" in the global variables pidfile_fd,
+ * pidfile_path and pidfile_pid so that any further call to pidfile_lock(3)
+ * can check if we are recreating the same file or a new one.
+ *
+ * Returns 0 on success, otherwise the pid of the process who owns the
+ * lock if it can be read, otherwise -1. */
+pid_t
+pidfile_lock(const char *path)
+{
+	char dpath[PATH_MAX];
+	static bool registered_atexit = false;
+
+	/* Register for cleanup with atexit. */
+	if (!registered_atexit) {
+		if (atexit(pidfile_cleanup) == -1)
+			return -1;
+		registered_atexit = true;
+	}
+
+	if (path == NULL || strchr(path, '/') == NULL) {
+		if (pidfile_varrun_path(dpath, sizeof(dpath), path) == -1)
+			return -1;
+		path = dpath;
+	}
+
+	/* If path has changed (no good reason), clean up the old pidfile. */
+	if (pidfile_fd != -1 && strcmp(pidfile_path, path) != 0)
+		pidfile_clean();
+
+	if (pidfile_fd == -1) {
+		int fd, opts;
+
+		opts = O_WRONLY | O_CREAT | O_NONBLOCK;
+#ifdef O_CLOEXEC
+		opts |= O_CLOEXEC;
+#endif
+#ifdef O_EXLOCK
+		opts |=	O_EXLOCK;
+#endif
+		if ((fd = open(path, opts, 0644)) == -1)
+			goto return_pid;
+#ifndef O_CLOEXEC
+		if ((opts = fcntl(fd, F_GETFD)) == -1 ||
+		    fctnl(fd, F_SETFL, opts | FD_CLOEXEC) == -1)
+		{
+			int error = errno;
+
+			(void) close(fd);
+			errno = error;
+			return -1;
+		}
+#endif
+#ifndef O_EXLOCK
+		if (flock(fd, LOCK_EX | LOCK_NB) == -1) {
+			int error = errno;
+
+			(void) close(fd);
+			if (error != EAGAIN) {
+				errno = error;
+				return -1;
+			}
+			fd = -1;
+		}
+#endif
+
+return_pid:
+		if (fd == -1) {
+			pid_t pid;
+
+			if (errno == EAGAIN) {
+				/* The pidfile is locked, return the process ID
+				 * it contains.
+				 * If sucessful, set errno to EEXIST. */
+				if ((pid = pidfile_read(path)) != -1)
+					errno = EEXIST;
+			} else
+				pid = -1;
+
+			return pid;
+		}
+		pidfile_fd = fd;
+		strlcpy(pidfile_path, path, sizeof(pidfile_path));
+	}
+
+	pidfile_pid = getpid();
+
+	/* Truncate the file, as we could be re-writing it.
+	 * Then write the process ID. */
+	if (ftruncate(pidfile_fd, 0) == -1 ||
+	    lseek(pidfile_fd, 0, SEEK_SET) == -1 ||
+	    dprintf(pidfile_fd, "%d\n", pidfile_pid) == -1)
+	{
+		int error = errno;
+
+		pidfile_cleanup();
+		errno = error;
+		return -1;
+	}
+
+	/* Hold the fd open to persist the lock. */
+	return 0;
+}
diff --git a/compat/pidfile.h b/compat/pidfile.h
new file mode 100644
index 00000000..89ebad81
--- /dev/null
+++ b/compat/pidfile.h
@@ -0,0 +1,37 @@
+/*
+ * pidfile_lock and pidfile_read
+ * Copyright (c) 2016 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#ifndef PIDFILE_H
+#define PIDFILE_H
+
+#include <unistd.h>
+
+int		pidfile_clean(void);
+pid_t		pidfile_lock(const char *);
+pid_t		pidfile_read(const char *);
+
+#endif
diff --git a/compat/posix_spawn.c b/compat/posix_spawn.c
new file mode 100644
index 00000000..0cb142e5
--- /dev/null
+++ b/compat/posix_spawn.c
@@ -0,0 +1,157 @@
+/*
+ * dhcpcd - DHCP client daemon
+ * Copyright (c) 2006-2012 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+/* This implementation of posix_spawn is only suitable for the needs of dhcpcd
+ * but it could easily be extended to other applications. */
+
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include <errno.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "../common.h"
+#include "posix_spawn.h"
+
+#ifndef _NSIG
+#ifdef _SIG_MAXSIG
+#define _NSIG _SIG_MAXSIG + 1
+#else
+/* Guess */
+#define _NSIG SIGPWR + 1
+#endif
+#endif
+
+extern char **environ;
+
+static int
+posix_spawnattr_handle(const posix_spawnattr_t *attrp)
+{
+	struct sigaction sa;
+	int i;
+
+	if (attrp->posix_attr_flags & POSIX_SPAWN_SETSIGMASK)
+		sigprocmask(SIG_SETMASK, &attrp->posix_attr_sigmask, NULL);
+
+	if (attrp->posix_attr_flags & POSIX_SPAWN_SETSIGDEF) {
+		memset(&sa, 0, sizeof(sa));
+		sa.sa_handler = SIG_DFL;
+		for (i = 1; i < _NSIG; i++) {
+			if (sigismember(&attrp->posix_attr_sigdefault, i)) {
+				if (sigaction(i, &sa, NULL) == -1)
+					return -1;
+			}
+		}
+	}
+
+	return 0;
+}
+
+inline static int
+is_vfork_safe(short int flags)
+{
+	return !(flags & (POSIX_SPAWN_SETSIGDEF | POSIX_SPAWN_SETSIGMASK));
+}
+
+int
+posix_spawn(pid_t *pid, const char *path,
+	const posix_spawn_file_actions_t *file_actions,
+	const posix_spawnattr_t *attrp,
+	char *const argv[], char *const envp[])
+{
+	short int flags;
+	pid_t p;
+	volatile int error;
+
+	error = 0;
+	flags = attrp ? attrp->posix_attr_flags : 0;
+	if (file_actions == NULL && is_vfork_safe(flags))
+		p = vfork();
+	else
+#ifdef THERE_IS_NO_FORK
+		return ENOSYS;
+#else
+		p = fork();
+#endif
+	switch (p) {
+	case -1:
+		return errno;
+	case 0:
+		if (attrp) {
+			error = posix_spawnattr_handle(attrp);
+			if (error)
+				_exit(127);
+		}
+		execve(path, argv, envp);
+		error = errno;
+		_exit(127);
+	default:
+		if (error != 0)
+			waitpid(p, NULL, WNOHANG);
+		else if (pid != NULL)
+			*pid = p;
+		return error;
+	}
+}
+
+int
+posix_spawnattr_init(posix_spawnattr_t *attr)
+{
+
+	memset(attr, 0, sizeof(*attr));
+	attr->posix_attr_flags = 0;
+	sigprocmask(0, NULL, &attr->posix_attr_sigmask);
+	sigemptyset(&attr->posix_attr_sigdefault);
+	return 0;
+}
+
+int
+posix_spawnattr_setflags(posix_spawnattr_t *attr, short flags)
+{
+
+	attr->posix_attr_flags = flags;
+	return 0;
+}
+
+int
+posix_spawnattr_setsigmask(posix_spawnattr_t *attr, const sigset_t *sigmask)
+{
+
+	attr->posix_attr_sigmask = *sigmask;
+	return 0;
+}
+
+int
+posix_spawnattr_setsigdefault(posix_spawnattr_t *attr, const sigset_t *sigmask)
+{
+
+	attr->posix_attr_sigdefault = *sigmask;
+	return 0;
+}
diff --git a/compat/posix_spawn.h b/compat/posix_spawn.h
new file mode 100644
index 00000000..ccfb0f0c
--- /dev/null
+++ b/compat/posix_spawn.h
@@ -0,0 +1,53 @@
+/*
+ * dhcpcd - DHCP client daemon
+ * Copyright (c) 2006-2012 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#ifndef POSIX_SPAWN_H
+#define POSIX_SPAWN_H
+
+#include <signal.h>
+
+typedef struct {
+	short posix_attr_flags;
+#define POSIX_SPAWN_SETSIGDEF		0x10
+#define POSIX_SPAWN_SETSIGMASK		0x20
+	sigset_t posix_attr_sigmask;
+	sigset_t posix_attr_sigdefault;
+} posix_spawnattr_t;
+
+typedef struct {
+//	int unused;
+} posix_spawn_file_actions_t;
+
+int posix_spawn(pid_t *, const char *,
+    const posix_spawn_file_actions_t *, const posix_spawnattr_t *,
+    char *const [], char *const []);
+int posix_spawnattr_init(posix_spawnattr_t *);
+int posix_spawnattr_setflags(posix_spawnattr_t *, short);
+int posix_spawnattr_setsigmask(posix_spawnattr_t *, const sigset_t *);
+int posix_spawnattr_setsigdefault(posix_spawnattr_t *, const sigset_t *);
+
+#endif
diff --git a/compat/queue.h b/compat/queue.h
new file mode 100644
index 00000000..99ac6b94
--- /dev/null
+++ b/compat/queue.h
@@ -0,0 +1,175 @@
+/*	$NetBSD: queue.h,v 1.65 2013/12/25 17:19:34 christos Exp $	*/
+
+/*
+ * Copyright (c) 1991, 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. 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.
+ *
+ *	@(#)queue.h	8.5 (Berkeley) 8/20/94
+ */
+
+#ifndef COMPAT_QUEUE_H
+#define COMPAT_QUEUE_H
+
+/*
+ * Tail queue definitions.
+ */
+#ifndef TAILQ_END
+#define	TAILQ_END(head)			(NULL)
+#endif
+
+#ifndef TAILQ_HEAD
+#define	_TAILQ_HEAD(name, type, qual)					\
+struct name {								\
+	qual type *tqh_first;		/* first element */		\
+	qual type *qual *tqh_last;	/* addr of last next element */	\
+}
+#define TAILQ_HEAD(name, type)	_TAILQ_HEAD(name, struct type,)
+
+#define	TAILQ_HEAD_INITIALIZER(head)					\
+	{ TAILQ_END(head), &(head).tqh_first }
+
+#define	_TAILQ_ENTRY(type, qual)					\
+struct {								\
+	qual type *tqe_next;		/* next element */		\
+	qual type *qual *tqe_prev;	/* address of previous next element */\
+}
+#define TAILQ_ENTRY(type)	_TAILQ_ENTRY(struct type,)
+#endif /* !TAILQ_HEAD */
+
+/*
+ * Tail queue access methods.
+ */
+#ifndef TAILQ_FIRST
+#define	TAILQ_FIRST(head)		((head)->tqh_first)
+#define	TAILQ_NEXT(elm, field)		((elm)->field.tqe_next)
+#define	TAILQ_LAST(head, headname) \
+	(*(((struct headname *)((head)->tqh_last))->tqh_last))
+#define	TAILQ_PREV(elm, headname, field) \
+	(*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
+#define	TAILQ_EMPTY(head)		(TAILQ_FIRST(head) == TAILQ_END(head))
+#endif /* !TAILQ_FIRST */
+
+#ifndef TAILQ_FOREACH
+#define	TAILQ_FOREACH(var, head, field)					\
+	for ((var) = ((head)->tqh_first);				\
+	    (var) != TAILQ_END(head);					\
+	    (var) = ((var)->field.tqe_next))
+
+#define	TAILQ_FOREACH_REVERSE(var, head, headname, field)		\
+	for ((var) = (*(((struct headname *)((head)->tqh_last))->tqh_last));\
+	    (var) != TAILQ_END(head);					\
+	    (var) = (*(((struct headname *)((var)->field.tqe_prev))->tqh_last)))
+#endif /* !TAILQ_FOREACH */
+
+#ifndef TAILQ_INIT
+#define	TAILQ_INIT(head) do {						\
+	(head)->tqh_first = TAILQ_END(head);				\
+	(head)->tqh_last = &(head)->tqh_first;				\
+} while (/*CONSTCOND*/0)
+
+#define	TAILQ_INSERT_HEAD(head, elm, field) do {			\
+	if (((elm)->field.tqe_next = (head)->tqh_first) != TAILQ_END(head))\
+		(head)->tqh_first->field.tqe_prev =			\
+		    &(elm)->field.tqe_next;				\
+	else								\
+		(head)->tqh_last = &(elm)->field.tqe_next;		\
+	(head)->tqh_first = (elm);					\
+	(elm)->field.tqe_prev = &(head)->tqh_first;			\
+} while (/*CONSTCOND*/0)
+
+#define	TAILQ_INSERT_TAIL(head, elm, field) do {			\
+	(elm)->field.tqe_next = TAILQ_END(head);			\
+	(elm)->field.tqe_prev = (head)->tqh_last;			\
+	*(head)->tqh_last = (elm);					\
+	(head)->tqh_last = &(elm)->field.tqe_next;			\
+} while (/*CONSTCOND*/0)
+
+#define	TAILQ_INSERT_AFTER(head, listelm, elm, field) do {		\
+	if (((elm)->field.tqe_next = (listelm)->field.tqe_next) !=	\
+	    TAILQ_END(head))						\
+		(elm)->field.tqe_next->field.tqe_prev =			\
+		    &(elm)->field.tqe_next;				\
+	else								\
+		(head)->tqh_last = &(elm)->field.tqe_next;		\
+	(listelm)->field.tqe_next = (elm);				\
+	(elm)->field.tqe_prev = &(listelm)->field.tqe_next;		\
+} while (/*CONSTCOND*/0)
+
+#define	TAILQ_INSERT_BEFORE(listelm, elm, field) do {			\
+	(elm)->field.tqe_prev = (listelm)->field.tqe_prev;		\
+	(elm)->field.tqe_next = (listelm);				\
+	*(listelm)->field.tqe_prev = (elm);				\
+	(listelm)->field.tqe_prev = &(elm)->field.tqe_next;		\
+} while (/*CONSTCOND*/0)
+
+#define	TAILQ_REMOVE(head, elm, field) do {				\
+	if (((elm)->field.tqe_next) != TAILQ_END(head))			\
+		(elm)->field.tqe_next->field.tqe_prev =			\
+		    (elm)->field.tqe_prev;				\
+	else								\
+		(head)->tqh_last = (elm)->field.tqe_prev;		\
+	*(elm)->field.tqe_prev = (elm)->field.tqe_next;			\
+} while (/*CONSTCOND*/0)
+#endif /* !TAILQ_INIT */
+
+#ifndef TAILQ_REPLACE
+#define TAILQ_REPLACE(head, elm, elm2, field) do {                      \
+        if (((elm2)->field.tqe_next = (elm)->field.tqe_next) !=		\
+	    TAILQ_END(head))						\
+                (elm2)->field.tqe_next->field.tqe_prev =                \
+                    &(elm2)->field.tqe_next;                            \
+        else                                                            \
+                (head)->tqh_last = &(elm2)->field.tqe_next;             \
+        (elm2)->field.tqe_prev = (elm)->field.tqe_prev;                 \
+        *(elm2)->field.tqe_prev = (elm2);                               \
+} while (/*CONSTCOND*/0)
+#endif /* !TAILQ_REPLACE */
+
+#ifndef TAILQ_FOREACH_SAFE
+#define	TAILQ_FOREACH_SAFE(var, head, field, next)			\
+	for ((var) = TAILQ_FIRST(head);					\
+	    (var) != TAILQ_END(head) &&					\
+	    ((next) = TAILQ_NEXT(var, field), 1); (var) = (next))
+
+#define	TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, prev)	\
+	for ((var) = TAILQ_LAST((head), headname);			\
+	    (var) != TAILQ_END(head) &&					\
+	    ((prev) = TAILQ_PREV((var), headname, field), 1); (var) = (prev))
+#endif /* !TAILQ_FOREACH_SAFE */
+
+#ifndef TAILQ_CONCAT
+#define	TAILQ_CONCAT(head1, head2, field) do {				\
+	if (!TAILQ_EMPTY(head2)) {					\
+		*(head1)->tqh_last = (head2)->tqh_first;		\
+		(head2)->tqh_first->field.tqe_prev = (head1)->tqh_last;	\
+		(head1)->tqh_last = (head2)->tqh_last;			\
+		TAILQ_INIT((head2));					\
+	}								\
+} while (/*CONSTCOND*/0)
+#endif /* !TAILQ_CONCAT */
+
+#endif	/* !COMAPT_QUEUE_H */
diff --git a/compat/reallocarray.c b/compat/reallocarray.c
new file mode 100644
index 00000000..2c77f084
--- /dev/null
+++ b/compat/reallocarray.c
@@ -0,0 +1,46 @@
+/*
+ * reallocarray(3)
+ * Copyright (c) 2016 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#include <errno.h>
+#include <limits.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "reallocarray.h"
+
+#define SQRT_SIZE_MAX (((size_t)1) << (sizeof(size_t) * CHAR_BIT / 2))
+void *
+reallocarray(void *ptr, size_t n, size_t size)
+{
+
+	if ((n | size) >= SQRT_SIZE_MAX && n > SIZE_MAX / size) {
+		errno = EOVERFLOW;
+		return NULL;
+	}
+	return realloc(ptr, n * size);
+}
diff --git a/compat/reallocarray.h b/compat/reallocarray.h
new file mode 100644
index 00000000..7d27fe25
--- /dev/null
+++ b/compat/reallocarray.h
@@ -0,0 +1,33 @@
+/*
+ * reallocarray(3)
+ * Copyright (c) 2016 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#ifndef REALLOCARRAY_H
+#define REALLOCARRAY_H
+
+void *reallocarray(void *, size_t, size_t);
+
+#endif
diff --git a/compat/strlcpy.c b/compat/strlcpy.c
new file mode 100644
index 00000000..47776a05
--- /dev/null
+++ b/compat/strlcpy.c
@@ -0,0 +1,52 @@
+/*
+ * dhcpcd - DHCP client daemon
+ * Copyright (c) 2006-2009 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#include <sys/types.h>
+
+#include "strlcpy.h"
+
+size_t
+strlcpy(char *dst, const char *src, size_t size)
+{
+	const char *s = src;
+	size_t n = size;
+
+	if (n && --n)
+		do {
+			if (!(*dst++ = *src++))
+				break;
+		} while (--n);
+
+	if (!n) {
+		if (size)
+			*dst = '\0';
+		while (*src++);
+	}
+
+
+	return (size_t)(src - s - 1);
+}
diff --git a/compat/strlcpy.h b/compat/strlcpy.h
new file mode 100644
index 00000000..951390a9
--- /dev/null
+++ b/compat/strlcpy.h
@@ -0,0 +1,34 @@
+/*
+ * dhcpcd - DHCP client daemon
+ * Copyright (c) 2006-2009 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#ifndef STRLCPY_H
+#define STRLCPY_H
+
+#include <sys/types.h>
+
+size_t strlcpy(char *, const char *, size_t);
+#endif
diff --git a/compat/strtoi.c b/compat/strtoi.c
new file mode 100644
index 00000000..701d57b3
--- /dev/null
+++ b/compat/strtoi.c
@@ -0,0 +1,112 @@
+/*
+ * dhcpcd - DHCP client daemon
+ * Copyright (c) 2006-2015 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#include <errno.h>
+#include <inttypes.h>
+#include <stdlib.h>
+
+#include "strtoi.h"
+
+intmax_t
+strtoi(const char * __restrict nptr, char ** __restrict endptr, int base,
+    intmax_t lo, intmax_t hi, int *rstatus)
+{
+	int serrno;
+	intmax_t r;
+	char *ep;
+	int rep;
+
+	if (endptr == NULL)
+		endptr = &ep;
+	if (rstatus == NULL)
+		rstatus = &rep;
+
+	serrno = errno;
+	errno = 0;
+	r = strtoimax(nptr, endptr, base);
+	*rstatus = errno;
+	errno = serrno;
+
+	if (*rstatus == 0) {
+		if (nptr == *endptr)
+			*rstatus = ECANCELED;
+		else if (**endptr != '\0')
+			*rstatus = ENOTSUP;
+	}
+
+	if (r < lo) {
+		if (*rstatus == 0)
+			*rstatus = ERANGE;
+		return lo;
+	}
+	if (r > hi) {
+		if (*rstatus == 0)
+			*rstatus = ERANGE;
+		return hi;
+	}
+	return r;
+}
+
+uintmax_t
+strtou(const char * __restrict nptr, char ** __restrict endptr, int base,
+    uintmax_t lo, uintmax_t hi, int *rstatus)
+{
+	int serrno;
+	uintmax_t r;
+	char *ep;
+	int rep;
+
+	if (endptr == NULL)
+		endptr = &ep;
+	if (rstatus == NULL)
+		rstatus = &rep;
+
+	serrno = errno;
+	errno = 0;
+	r = strtoumax(nptr, endptr, base);
+	*rstatus = errno;
+	errno = serrno;
+
+	if (*rstatus == 0) {
+		if (nptr == *endptr)
+			*rstatus = ECANCELED;
+		else if (**endptr != '\0')
+			*rstatus = ENOTSUP;
+	}
+
+	if (r < lo) {
+		if (*rstatus == 0)
+			*rstatus = ERANGE;
+		return lo;
+	}
+	if (r > hi) {
+		if (*rstatus == 0)
+			*rstatus = ERANGE;
+		return hi;
+	}
+	return r;
+}
diff --git a/compat/strtoi.h b/compat/strtoi.h
new file mode 100644
index 00000000..4b0c878c
--- /dev/null
+++ b/compat/strtoi.h
@@ -0,0 +1,37 @@
+/*
+ * dhcpcd - DHCP client daemon
+ * Copyright (c) 2006-2015 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#ifndef STRTOI_H
+#define STRTOI_H
+
+#include <inttypes.h>
+
+intmax_t strtoi(const char * __restrict nptr, char ** __restrict endptr,
+    int base, intmax_t lo, intmax_t hi, int *rstatus);
+uintmax_t strtou(const char * __restrict nptr, char ** __restrict endptr,
+    int base, uintmax_t lo, uintmax_t hi, int *rstatus);
+#endif