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diff --git a/src/posix_spawn.c b/src/posix_spawn.c
new file mode 100644
index 0000000..18ceb06
--- /dev/null
+++ b/src/posix_spawn.c
@@ -0,0 +1,156 @@
+/*
+ * 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 "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;
+}