/*
   +----------------------------------------------------------------------+
   | Copyright (c) The PHP Group                                          |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | http://www.php.net/license/3_01.txt                                  |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Author: Wez Furlong <wez@thebrainroom.com>                           |
   +----------------------------------------------------------------------+
 */

#include "php.h"
#include <stdio.h>
#include <ctype.h>
#include <signal.h>
#include "php_string.h"
#include "ext/standard/head.h"
#include "ext/standard/basic_functions.h"
#include "ext/standard/file.h"
#include "exec.h"
#include "php_globals.h"
#include "SAPI.h"
#include "main/php_network.h"
#include "zend_smart_string.h"

#if HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif

#if HAVE_FCNTL_H
#include <fcntl.h>
#endif

/* This symbol is defined in ext/standard/config.m4.
 * Essentially, it is set if you HAVE_FORK || PHP_WIN32
 * Other platforms may modify that configure check and add suitable #ifdefs
 * around the alternate code. */
#ifdef PHP_CAN_SUPPORT_PROC_OPEN

#if HAVE_OPENPTY
# if HAVE_PTY_H
#  include <pty.h>
# elif defined(__FreeBSD__)
/* FreeBSD defines `openpty` in <libutil.h> */
#  include <libutil.h>
# elif defined(__NetBSD__) || defined(__DragonFly__)
/* On recent NetBSD/DragonFlyBSD releases the emalloc, estrdup ... calls had been introduced in libutil */
#  if defined(__NetBSD__)
#    include <sys/termios.h>
#  else
#    include <termios.h>
#  endif
extern int openpty(int *, int *, char *, struct termios *, struct winsize *);
# elif defined(__sun)
#    include <termios.h>
# else
/* Mac OS X (and some BSDs) define `openpty` in <util.h> */
#  include <util.h>
# endif
#elif defined(__sun)
# include <fcntl.h>
# include <stropts.h>
# include <termios.h>
# define HAVE_OPENPTY 1

/* Solaris before version 11.4 and Illumos do not have any openpty implementation */
int openpty(int *master, int *slave, char *name, struct termios *termp, struct winsize *winp)
{
	int fd, sd;
	const char *slaveid;

	assert(master);
	assert(slave);

	sd = *master = *slave = -1;
	fd = open("/dev/ptmx", O_NOCTTY|O_RDWR);
	if (fd == -1) {
		return -1;
	}
	/* Checking if we can have to the pseudo terminal */
	if (grantpt(fd) != 0 || unlockpt(fd) != 0) {
		goto fail;
	}
	slaveid = ptsname(fd);
	if (!slaveid) {
		goto fail;
	}

	/* Getting the slave path and pushing pseudo terminal */
	sd = open(slaveid, O_NOCTTY|O_RDONLY);
	if (sd == -1 || ioctl(sd, I_PUSH, "ptem") == -1) {
		goto fail;
	}
	if (termp) {
		if (tcgetattr(sd, termp) < 0) {
			goto fail;
		}
	}
	if (winp) {
		if (ioctl(sd, TIOCSWINSZ, winp) == -1) {
			goto fail;
		}
	}

	*slave = sd;
	*master = fd;
	return 0;
fail:
	if (sd != -1) {
		close(sd);
	}
	if (fd != -1) {
		close(fd);
	}
	return -1;
}
#endif

#include "proc_open.h"

static int le_proc_open; /* Resource number for `proc` resources */

/* {{{ _php_array_to_envp
 * Process the `environment` argument to `proc_open`
 * Convert into data structures which can be passed to underlying OS APIs like `exec` on POSIX or
 * `CreateProcessW` on Win32 */
static php_process_env _php_array_to_envp(zval *environment)
{
	zval *element;
	php_process_env env;
	zend_string *key, *str;
#ifndef PHP_WIN32
	char **ep;
#endif
	char *p;
	size_t sizeenv = 0;
	HashTable *env_hash; /* temporary PHP array used as helper */

	memset(&env, 0, sizeof(env));

	if (!environment) {
		return env;
	}

	uint32_t cnt = zend_hash_num_elements(Z_ARRVAL_P(environment));

	if (cnt < 1) {
#ifndef PHP_WIN32
		env.envarray = (char **) ecalloc(1, sizeof(char *));
#endif
		env.envp = (char *) ecalloc(4, 1);
		return env;
	}

	ALLOC_HASHTABLE(env_hash);
	zend_hash_init(env_hash, cnt, NULL, NULL, 0);

	/* first, we have to get the size of all the elements in the hash */
	ZEND_HASH_FOREACH_STR_KEY_VAL(Z_ARRVAL_P(environment), key, element) {
		str = zval_get_string(element);

		if (ZSTR_LEN(str) == 0) {
			zend_string_release_ex(str, 0);
			continue;
		}

		sizeenv += ZSTR_LEN(str) + 1;

		if (key && ZSTR_LEN(key)) {
			sizeenv += ZSTR_LEN(key) + 1;
			zend_hash_add_ptr(env_hash, key, str);
		} else {
			zend_hash_next_index_insert_ptr(env_hash, str);
		}
	} ZEND_HASH_FOREACH_END();

#ifndef PHP_WIN32
	ep = env.envarray = (char **) ecalloc(cnt + 1, sizeof(char *));
#endif
	p = env.envp = (char *) ecalloc(sizeenv + 4, 1);

	ZEND_HASH_FOREACH_STR_KEY_PTR(env_hash, key, str) {
#ifndef PHP_WIN32
		*ep = p;
		++ep;
#endif

		if (key) {
			memcpy(p, ZSTR_VAL(key), ZSTR_LEN(key));
			p += ZSTR_LEN(key);
			*p++ = '=';
		}

		memcpy(p, ZSTR_VAL(str), ZSTR_LEN(str));
		p += ZSTR_LEN(str);
		*p++ = '\0';
		zend_string_release_ex(str, 0);
	} ZEND_HASH_FOREACH_END();

	assert((uint32_t)(p - env.envp) <= sizeenv);

	zend_hash_destroy(env_hash);
	FREE_HASHTABLE(env_hash);

	return env;
}
/* }}} */

/* {{{ _php_free_envp
 * Free the structures allocated by `_php_array_to_envp` */
static void _php_free_envp(php_process_env env)
{
#ifndef PHP_WIN32
	if (env.envarray) {
		efree(env.envarray);
	}
#endif
	if (env.envp) {
		efree(env.envp);
	}
}
/* }}} */

/* {{{ proc_open_rsrc_dtor
 * Free `proc` resource, either because all references to it were dropped or because `pclose` or
 * `proc_close` were called */
static void proc_open_rsrc_dtor(zend_resource *rsrc)
{
	php_process_handle *proc = (php_process_handle*)rsrc->ptr;
#ifdef PHP_WIN32
	DWORD wstatus;
#elif HAVE_SYS_WAIT_H
	int wstatus;
	int waitpid_options = 0;
	pid_t wait_pid;
#endif

	/* Close all handles to avoid a deadlock */
	for (int i = 0; i < proc->npipes; i++) {
		if (proc->pipes[i] != NULL) {
			GC_DELREF(proc->pipes[i]);
			zend_list_close(proc->pipes[i]);
			proc->pipes[i] = NULL;
		}
	}

	/* `pclose_wait` tells us: Are we freeing this resource because `pclose` or `proc_close` were
	 * called? If so, we need to wait until the child process exits, because its exit code is
	 * needed as the return value of those functions.
	 * But if we're freeing the resource because of GC, don't wait. */
#ifdef PHP_WIN32
	if (FG(pclose_wait)) {
		WaitForSingleObject(proc->childHandle, INFINITE);
	}
	GetExitCodeProcess(proc->childHandle, &wstatus);
	if (wstatus == STILL_ACTIVE) {
		FG(pclose_ret) = -1;
	} else {
		FG(pclose_ret) = wstatus;
	}
	CloseHandle(proc->childHandle);

#elif HAVE_SYS_WAIT_H
	if (!FG(pclose_wait)) {
		waitpid_options = WNOHANG;
	}
	do {
		wait_pid = waitpid(proc->child, &wstatus, waitpid_options);
	} while (wait_pid == -1 && errno == EINTR);

	if (wait_pid <= 0) {
		FG(pclose_ret) = -1;
	} else {
		if (WIFEXITED(wstatus)) {
			wstatus = WEXITSTATUS(wstatus);
		}
		FG(pclose_ret) = wstatus;
	}

#else
	FG(pclose_ret) = -1;
#endif

	_php_free_envp(proc->env);
	efree(proc->pipes);
	efree(proc->command);
	efree(proc);
}
/* }}} */

/* {{{ PHP_MINIT_FUNCTION(proc_open) */
PHP_MINIT_FUNCTION(proc_open)
{
	le_proc_open = zend_register_list_destructors_ex(proc_open_rsrc_dtor, NULL, "process",
		module_number);
	return SUCCESS;
}
/* }}} */

/* {{{ Kill a process opened by `proc_open` */
PHP_FUNCTION(proc_terminate)
{
	zval *zproc;
	php_process_handle *proc;
	zend_long sig_no = SIGTERM;

	ZEND_PARSE_PARAMETERS_START(1, 2)
		Z_PARAM_RESOURCE(zproc)
		Z_PARAM_OPTIONAL
		Z_PARAM_LONG(sig_no)
	ZEND_PARSE_PARAMETERS_END();

	proc = (php_process_handle*)zend_fetch_resource(Z_RES_P(zproc), "process", le_proc_open);
	if (proc == NULL) {
		RETURN_THROWS();
	}

#ifdef PHP_WIN32
	RETURN_BOOL(TerminateProcess(proc->childHandle, 255));
#else
	RETURN_BOOL(kill(proc->child, sig_no) == 0);
#endif
}
/* }}} */

/* {{{ Close a process opened by `proc_open` */
PHP_FUNCTION(proc_close)
{
	zval *zproc;
	php_process_handle *proc;

	ZEND_PARSE_PARAMETERS_START(1, 1)
		Z_PARAM_RESOURCE(zproc)
	ZEND_PARSE_PARAMETERS_END();

	proc = (php_process_handle*)zend_fetch_resource(Z_RES_P(zproc), "process", le_proc_open);
	if (proc == NULL) {
		RETURN_THROWS();
	}

	FG(pclose_wait) = 1; /* See comment in `proc_open_rsrc_dtor` */
	zend_list_close(Z_RES_P(zproc));
	FG(pclose_wait) = 0;
	RETURN_LONG(FG(pclose_ret));
}
/* }}} */

/* {{{ Get information about a process opened by `proc_open` */
PHP_FUNCTION(proc_get_status)
{
	zval *zproc;
	php_process_handle *proc;
#ifdef PHP_WIN32
	DWORD wstatus;
#elif HAVE_SYS_WAIT_H
	int wstatus;
	pid_t wait_pid;
#endif
	int running = 1, signaled = 0, stopped = 0;
	int exitcode = -1, termsig = 0, stopsig = 0;

	ZEND_PARSE_PARAMETERS_START(1, 1)
		Z_PARAM_RESOURCE(zproc)
	ZEND_PARSE_PARAMETERS_END();

	proc = (php_process_handle*)zend_fetch_resource(Z_RES_P(zproc), "process", le_proc_open);
	if (proc == NULL) {
		RETURN_THROWS();
	}

	array_init(return_value);
	add_assoc_string(return_value, "command", proc->command);
	add_assoc_long(return_value, "pid", (zend_long)proc->child);

#ifdef PHP_WIN32
	GetExitCodeProcess(proc->childHandle, &wstatus);
	running = wstatus == STILL_ACTIVE;
	exitcode = running ? -1 : wstatus;

#elif HAVE_SYS_WAIT_H
	wait_pid = waitpid(proc->child, &wstatus, WNOHANG|WUNTRACED);

	if (wait_pid == proc->child) {
		if (WIFEXITED(wstatus)) {
			running = 0;
			exitcode = WEXITSTATUS(wstatus);
		}
		if (WIFSIGNALED(wstatus)) {
			running = 0;
			signaled = 1;
			termsig = WTERMSIG(wstatus);
		}
		if (WIFSTOPPED(wstatus)) {
			stopped = 1;
			stopsig = WSTOPSIG(wstatus);
		}
	} else if (wait_pid == -1) {
		/* The only error which could occur here is ECHILD, which means that the PID we were
		 * looking for either does not exist or is not a child of this process */
		running = 0;
	}
#endif

	add_assoc_bool(return_value, "running", running);
	add_assoc_bool(return_value, "signaled", signaled);
	add_assoc_bool(return_value, "stopped", stopped);
	add_assoc_long(return_value, "exitcode", exitcode);
	add_assoc_long(return_value, "termsig", termsig);
	add_assoc_long(return_value, "stopsig", stopsig);
}
/* }}} */

#ifdef PHP_WIN32

/* We use this to allow child processes to inherit handles
 * One static instance can be shared and used for all calls to `proc_open`, since the values are
 * never changed */
SECURITY_ATTRIBUTES php_proc_open_security = {
	.nLength = sizeof(SECURITY_ATTRIBUTES),
	.lpSecurityDescriptor = NULL,
	.bInheritHandle = TRUE
};

# define pipe(pair)		(CreatePipe(&pair[0], &pair[1], &php_proc_open_security, 0) ? 0 : -1)

# define COMSPEC_NT	"cmd.exe"

static inline HANDLE dup_handle(HANDLE src, BOOL inherit, BOOL closeorig)
{
	HANDLE copy, self = GetCurrentProcess();

	if (!DuplicateHandle(self, src, self, &copy, 0, inherit, DUPLICATE_SAME_ACCESS |
				(closeorig ? DUPLICATE_CLOSE_SOURCE : 0)))
		return NULL;
	return copy;
}

static inline HANDLE dup_fd_as_handle(int fd)
{
	return dup_handle((HANDLE)_get_osfhandle(fd), TRUE, FALSE);
}

# define close_descriptor(fd)	CloseHandle(fd)
#else /* !PHP_WIN32 */
# define close_descriptor(fd)	close(fd)
#endif

/* Determines the type of a descriptor item. */
typedef enum _descriptor_type {
	DESCRIPTOR_TYPE_STD,
	DESCRIPTOR_TYPE_PIPE,
	DESCRIPTOR_TYPE_SOCKET
} descriptor_type;

/* One instance of this struct is created for each item in `$descriptorspec` argument to `proc_open`
 * They are used within `proc_open` and freed before it returns */
typedef struct _descriptorspec_item {
	int index;                       /* desired FD # in child process */
	descriptor_type type;
	php_file_descriptor_t childend;  /* FD # opened for use in child
	                                  * (will be copied to `index` in child) */
	php_file_descriptor_t parentend; /* FD # opened for use in parent
	                                  * (for pipes only; will be 0 otherwise) */
	int mode_flags;                  /* mode for opening FDs: r/o, r/w, binary (on Win32), etc */
} descriptorspec_item;

static zend_string *get_valid_arg_string(zval *zv, int elem_num) {
	zend_string *str = zval_get_string(zv);
	if (!str) {
		return NULL;
	}

	if (strlen(ZSTR_VAL(str)) != ZSTR_LEN(str)) {
		zend_value_error("Command array element %d contains a null byte", elem_num);
		zend_string_release(str);
		return NULL;
	}

	return str;
}

#ifdef PHP_WIN32
static void append_backslashes(smart_string *str, size_t num_bs)
{
	for (size_t i = 0; i < num_bs; i++) {
		smart_string_appendc(str, '\\');
	}
}

/* See https://docs.microsoft.com/en-us/cpp/cpp/parsing-cpp-command-line-arguments */
static void append_win_escaped_arg(smart_string *str, char *arg)
{
	char c;
	size_t num_bs = 0;
	smart_string_appendc(str, '"');
	while ((c = *arg)) {
		if (c == '\\') {
			num_bs++;
		} else {
			if (c == '"') {
				/* Backslashes before " need to be doubled. */
				num_bs = num_bs * 2 + 1;
			}
			append_backslashes(str, num_bs);
			smart_string_appendc(str, c);
			num_bs = 0;
		}
		arg++;
	}
	append_backslashes(str, num_bs * 2);
	smart_string_appendc(str, '"');
}

static char *create_win_command_from_args(HashTable *args)
{
	smart_string str = {0};
	zval *arg_zv;
	zend_bool is_prog_name = 1;
	int elem_num = 0;

	ZEND_HASH_FOREACH_VAL(args, arg_zv) {
		zend_string *arg_str = get_valid_arg_string(arg_zv, ++elem_num);
		if (!arg_str) {
			smart_string_free(&str);
			return NULL;
		}

		if (!is_prog_name) {
			smart_string_appendc(&str, ' ');
		}

		append_win_escaped_arg(&str, ZSTR_VAL(arg_str));

		is_prog_name = 0;
		zend_string_release(arg_str);
	} ZEND_HASH_FOREACH_END();
	smart_string_0(&str);
	return str.c;
}

/* Get a boolean option from the `other_options` array which can be passed to `proc_open`.
 * (Currently, all options apply on Windows only.) */
static int get_option(zval *other_options, char *opt_name)
{
	HashTable *opt_ary = Z_ARRVAL_P(other_options);
	zval *item = zend_hash_str_find_deref(opt_ary, opt_name, strlen(opt_name));
	return item != NULL &&
		(Z_TYPE_P(item) == IS_TRUE ||
		((Z_TYPE_P(item) == IS_LONG) && Z_LVAL_P(item)));
}

/* Initialize STARTUPINFOW struct, used on Windows when spawning a process.
 * Ref: https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/ns-processthreadsapi-startupinfow */
static void init_startup_info(STARTUPINFOW *si, descriptorspec_item *descriptors, int ndesc)
{
	memset(si, 0, sizeof(STARTUPINFOW));
	si->cb = sizeof(STARTUPINFOW);
	si->dwFlags = STARTF_USESTDHANDLES;

	si->hStdInput  = GetStdHandle(STD_INPUT_HANDLE);
	si->hStdOutput = GetStdHandle(STD_OUTPUT_HANDLE);
	si->hStdError  = GetStdHandle(STD_ERROR_HANDLE);

	/* redirect stdin/stdout/stderr if requested */
	for (int i = 0; i < ndesc; i++) {
		switch (descriptors[i].index) {
			case 0:
				si->hStdInput = descriptors[i].childend;
				break;
			case 1:
				si->hStdOutput = descriptors[i].childend;
				break;
			case 2:
				si->hStdError = descriptors[i].childend;
				break;
		}
	}
}

static void init_process_info(PROCESS_INFORMATION *pi)
{
	memset(&pi, 0, sizeof(pi));
}

static int convert_command_to_use_shell(wchar_t **cmdw, size_t cmdw_len)
{
	size_t len = sizeof(COMSPEC_NT) + sizeof(" /s /c ") + cmdw_len + 3;
	wchar_t *cmdw_shell = (wchar_t *)malloc(len * sizeof(wchar_t));

	if (cmdw_shell == NULL) {
		php_error_docref(NULL, E_WARNING, "Command conversion failed");
		return FAILURE;
	}

	if (_snwprintf(cmdw_shell, len, L"%hs /s /c \"%s\"", COMSPEC_NT, *cmdw) == -1) {
		free(cmdw_shell);
		php_error_docref(NULL, E_WARNING, "Command conversion failed");
		return FAILURE;
	}

	free(*cmdw);
	*cmdw = cmdw_shell;

	return SUCCESS;
}
#endif

/* Convert command parameter array passed as first argument to `proc_open` into command string */
static char* get_command_from_array(HashTable *array, char ***argv, int num_elems)
{
	zval *arg_zv;
	char *command = NULL;
	int i = 0;

	*argv = safe_emalloc(sizeof(char *), num_elems + 1, 0);

	ZEND_HASH_FOREACH_VAL(array, arg_zv) {
		zend_string *arg_str = get_valid_arg_string(arg_zv, i + 1);
		if (!arg_str) {
			/* Terminate with NULL so exit_fail code knows how many entries to free */
			(*argv)[i] = NULL;
			if (command != NULL) {
				efree(command);
			}
			return NULL;
		}

		if (i == 0) {
			command = estrdup(ZSTR_VAL(arg_str));
		}

		(*argv)[i++] = estrdup(ZSTR_VAL(arg_str));
		zend_string_release(arg_str);
	} ZEND_HASH_FOREACH_END();

	(*argv)[i] = NULL;
	return command;
}

static descriptorspec_item* alloc_descriptor_array(zval *descriptorspec)
{
	int ndescriptors = zend_hash_num_elements(Z_ARRVAL_P(descriptorspec));
	return ecalloc(sizeof(descriptorspec_item), ndescriptors);
}

static zend_string* get_string_parameter(zval *array, int index, char *param_name)
{
	zval *array_item;
	if ((array_item = zend_hash_index_find(Z_ARRVAL_P(array), index)) == NULL) {
		zend_value_error("Missing %s", param_name);
		return NULL;
	}
	return zval_try_get_string(array_item);
}

static int set_proc_descriptor_to_blackhole(descriptorspec_item *desc)
{
#ifdef PHP_WIN32
	desc->childend = CreateFileA("nul", GENERIC_READ | GENERIC_WRITE,
		FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);
	if (desc->childend == NULL) {
		php_error_docref(NULL, E_WARNING, "Failed to open nul");
		return FAILURE;
	}
#else
	desc->childend = open("/dev/null", O_RDWR);
	if (desc->childend < 0) {
		php_error_docref(NULL, E_WARNING, "Failed to open /dev/null: %s", strerror(errno));
		return FAILURE;
	}
#endif
	return SUCCESS;
}

static int set_proc_descriptor_to_pty(descriptorspec_item *desc, int *master_fd, int *slave_fd)
{
#if HAVE_OPENPTY
	/* All FDs set to PTY in the child process will go to the slave end of the same PTY.
	 * Likewise, all the corresponding entries in `$pipes` in the parent will all go to the master
	 * end of the same PTY.
	 * If this is the first descriptorspec set to 'pty', find an available PTY and get master and
	 * slave FDs. */
	if (*master_fd == -1) {
		if (openpty(master_fd, slave_fd, NULL, NULL, NULL)) {
			php_error_docref(NULL, E_WARNING, "Could not open PTY (pseudoterminal): %s", strerror(errno));
			return FAILURE;
		}
	}

	desc->type       = DESCRIPTOR_TYPE_PIPE;
	desc->childend   = dup(*slave_fd);
	desc->parentend  = dup(*master_fd);
	desc->mode_flags = O_RDWR;
	return SUCCESS;
#else
	php_error_docref(NULL, E_WARNING, "PTY (pseudoterminal) not supported on this system");
	return FAILURE;
#endif
}

/* Mark the descriptor close-on-exec, so it won't be inherited by children */
static php_file_descriptor_t make_descriptor_cloexec(php_file_descriptor_t fd)
{
#ifdef PHP_WIN32
	return dup_handle(fd, FALSE, TRUE);
#else
#if defined(F_SETFD) && defined(FD_CLOEXEC)
	fcntl(fd, F_SETFD, FD_CLOEXEC);
#endif
	return fd;
#endif
}

static int set_proc_descriptor_to_pipe(descriptorspec_item *desc, zend_string *zmode)
{
	php_file_descriptor_t newpipe[2];

	if (pipe(newpipe)) {
		php_error_docref(NULL, E_WARNING, "Unable to create pipe %s", strerror(errno));
		return FAILURE;
	}

	desc->type = DESCRIPTOR_TYPE_PIPE;

	if (strncmp(ZSTR_VAL(zmode), "w", 1) != 0) {
		desc->parentend = newpipe[1];
		desc->childend = newpipe[0];
		desc->mode_flags = O_WRONLY;
	} else {
		desc->parentend = newpipe[0];
		desc->childend = newpipe[1];
		desc->mode_flags = O_RDONLY;
	}

	desc->parentend = make_descriptor_cloexec(desc->parentend);

#ifdef PHP_WIN32
	if (ZSTR_LEN(zmode) >= 2 && ZSTR_VAL(zmode)[1] == 'b')
		desc->mode_flags |= O_BINARY;
#endif

	return SUCCESS;
}

#ifdef PHP_WIN32
#define create_socketpair(socks) socketpair_win32(AF_INET, SOCK_STREAM, 0, (socks), 0)
#else
#define create_socketpair(socks) socketpair(AF_UNIX, SOCK_STREAM, 0, (socks))
#endif

static int set_proc_descriptor_to_socket(descriptorspec_item *desc)
{
	php_socket_t sock[2];

	if (create_socketpair(sock)) {
		zend_string *err = php_socket_error_str(php_socket_errno());
		php_error_docref(NULL, E_WARNING, "Unable to create socket pair: %s", ZSTR_VAL(err));
		zend_string_release(err);
		return FAILURE;
	}

	desc->type = DESCRIPTOR_TYPE_SOCKET;
	desc->parentend = make_descriptor_cloexec((php_file_descriptor_t) sock[0]);

	/* Pass sock[1] to child because it will never use overlapped IO on Windows. */
	desc->childend = (php_file_descriptor_t) sock[1];

	return SUCCESS;
}

static int set_proc_descriptor_to_file(descriptorspec_item *desc, zend_string *file_path,
	zend_string *file_mode)
{
	php_socket_t fd;

	/* try a wrapper */
	php_stream *stream = php_stream_open_wrapper(ZSTR_VAL(file_path), ZSTR_VAL(file_mode),
		REPORT_ERRORS|STREAM_WILL_CAST, NULL);
	if (stream == NULL) {
		return FAILURE;
	}

	/* force into an fd */
	if (php_stream_cast(stream, PHP_STREAM_CAST_RELEASE|PHP_STREAM_AS_FD, (void **)&fd,
		REPORT_ERRORS) == FAILURE) {
		return FAILURE;
	}

#ifdef PHP_WIN32
	desc->childend = dup_fd_as_handle((int)fd);
	_close((int)fd);

	/* Simulate the append mode by fseeking to the end of the file
	 * This introduces a potential race condition, but it is the best we can do */
	if (strchr(ZSTR_VAL(file_mode), 'a')) {
		SetFilePointer(desc->childend, 0, NULL, FILE_END);
	}
#else
	desc->childend = fd;
#endif
	return SUCCESS;
}

static int dup_proc_descriptor(php_file_descriptor_t from, php_file_descriptor_t *to,
	zend_ulong nindex)
{
#ifdef PHP_WIN32
	*to = dup_handle(from, TRUE, FALSE);
	if (*to == NULL) {
		php_error_docref(NULL, E_WARNING, "Failed to dup() for descriptor " ZEND_LONG_FMT, nindex);
		return FAILURE;
	}
#else
	*to = dup(from);
	if (*to < 0) {
		php_error_docref(NULL, E_WARNING, "Failed to dup() for descriptor " ZEND_LONG_FMT ": %s",
			nindex, strerror(errno));
		return FAILURE;
	}
#endif
	return SUCCESS;
}

static int redirect_proc_descriptor(descriptorspec_item *desc, int target,
	descriptorspec_item *descriptors, int ndesc, int nindex)
{
	php_file_descriptor_t redirect_to = PHP_INVALID_FD;

	for (int i = 0; i < ndesc; i++) {
		if (descriptors[i].index == target) {
			redirect_to = descriptors[i].childend;
			break;
		}
	}

	if (redirect_to == PHP_INVALID_FD) { /* Didn't find the index we wanted */
		if (target < 0 || target > 2) {
			php_error_docref(NULL, E_WARNING, "Redirection target %d not found", target);
			return FAILURE;
		}

		/* Support referring to a stdin/stdout/stderr pipe adopted from the parent,
		 * which happens whenever an explicit override is not provided. */
#ifndef PHP_WIN32
		redirect_to = target;
#else
		switch (target) {
			case 0: redirect_to = GetStdHandle(STD_INPUT_HANDLE); break;
			case 1: redirect_to = GetStdHandle(STD_OUTPUT_HANDLE); break;
			case 2: redirect_to = GetStdHandle(STD_ERROR_HANDLE); break;
			EMPTY_SWITCH_DEFAULT_CASE()
		}
#endif
	}

	return dup_proc_descriptor(redirect_to, &desc->childend, nindex);
}

/* Process one item from `$descriptorspec` argument to `proc_open` */
static int set_proc_descriptor_from_array(zval *descitem, descriptorspec_item *descriptors,
	int ndesc, int nindex, int *pty_master_fd, int *pty_slave_fd) {
	zend_string *ztype = get_string_parameter(descitem, 0, "handle qualifier");
	if (!ztype) {
		return FAILURE;
	}

	zend_string *zmode = NULL, *zfile = NULL;
	int retval = FAILURE;
	if (zend_string_equals_literal(ztype, "pipe")) {
		/* Set descriptor to pipe */
		zmode = get_string_parameter(descitem, 1, "mode parameter for 'pipe'");
		if (zmode == NULL) {
			goto finish;
		}
		retval = set_proc_descriptor_to_pipe(&descriptors[ndesc], zmode);
	} else if (zend_string_equals_literal(ztype, "socket")) {
		/* Set descriptor to socketpair */
		retval = set_proc_descriptor_to_socket(&descriptors[ndesc]);
	} else if (zend_string_equals_literal(ztype, "file")) {
		/* Set descriptor to file */
		if ((zfile = get_string_parameter(descitem, 1, "file name parameter for 'file'")) == NULL) {
			goto finish;
		}
		if ((zmode = get_string_parameter(descitem, 2, "mode parameter for 'file'")) == NULL) {
			goto finish;
		}
		retval = set_proc_descriptor_to_file(&descriptors[ndesc], zfile, zmode);
	} else if (zend_string_equals_literal(ztype, "redirect")) {
		/* Redirect descriptor to whatever another descriptor is set to */
		zval *ztarget = zend_hash_index_find_deref(Z_ARRVAL_P(descitem), 1);
		if (!ztarget) {
			zend_value_error("Missing redirection target");
			goto finish;
		}
		if (Z_TYPE_P(ztarget) != IS_LONG) {
			zend_value_error("Redirection target must be of type int, %s given", zend_zval_type_name(ztarget));
			goto finish;
		}

		retval = redirect_proc_descriptor(
			&descriptors[ndesc], (int)Z_LVAL_P(ztarget), descriptors, ndesc, nindex);
	} else if (zend_string_equals_literal(ztype, "null")) {
		/* Set descriptor to blackhole (discard all data written) */
		retval = set_proc_descriptor_to_blackhole(&descriptors[ndesc]);
	} else if (zend_string_equals_literal(ztype, "pty")) {
		/* Set descriptor to slave end of PTY */
		retval = set_proc_descriptor_to_pty(&descriptors[ndesc], pty_master_fd, pty_slave_fd);
	} else {
		php_error_docref(NULL, E_WARNING, "%s is not a valid descriptor spec/mode", ZSTR_VAL(ztype));
		goto finish;
	}

finish:
	if (zmode) zend_string_release(zmode);
	if (zfile) zend_string_release(zfile);
	zend_string_release(ztype);
	return retval;
}

static int set_proc_descriptor_from_resource(zval *resource, descriptorspec_item *desc, int nindex)
{
	/* Should be a stream - try and dup the descriptor */
	php_stream *stream = (php_stream*)zend_fetch_resource(Z_RES_P(resource), "stream",
		php_file_le_stream());
	if (stream == NULL) {
		return FAILURE;
	}

	php_socket_t fd;
	int status = php_stream_cast(stream, PHP_STREAM_AS_FD, (void **)&fd, REPORT_ERRORS);
	if (status == FAILURE) {
		return FAILURE;
	}

#ifdef PHP_WIN32
	php_file_descriptor_t fd_t = (php_file_descriptor_t)_get_osfhandle(fd);
#else
	php_file_descriptor_t fd_t = fd;
#endif
	if (dup_proc_descriptor(fd_t, &desc->childend, nindex) == FAILURE) {
		return FAILURE;
	}

	return SUCCESS;
}

#ifndef PHP_WIN32
static int close_parentends_of_pipes(descriptorspec_item *descriptors, int ndesc)
{
	/* We are running in child process
	 * Close the 'parent end' of pipes which were opened before forking/spawning
	 * Also, dup() the child end of all pipes as necessary so they will use the FD
	 * number which the user requested */
	for (int i = 0; i < ndesc; i++) {
		if (descriptors[i].type != DESCRIPTOR_TYPE_STD) {
			close(descriptors[i].parentend);
		}
		if (descriptors[i].childend != descriptors[i].index) {
			if (dup2(descriptors[i].childend, descriptors[i].index) < 0) {
				php_error_docref(NULL, E_WARNING, "Unable to copy file descriptor %d (for pipe) into " \
					"file descriptor %d: %s", descriptors[i].childend, descriptors[i].index, strerror(errno));
				return FAILURE;
			}
			close(descriptors[i].childend);
		}
	}

	return SUCCESS;
}
#endif

static void close_all_descriptors(descriptorspec_item *descriptors, int ndesc)
{
	for (int i = 0; i < ndesc; i++) {
		close_descriptor(descriptors[i].childend);
		if (descriptors[i].parentend)
			close_descriptor(descriptors[i].parentend);
	}
}

static void efree_argv(char **argv)
{
	if (argv) {
		char **arg = argv;
		while (*arg != NULL) {
			efree(*arg);
			arg++;
		}
		efree(argv);
	}
}

/* {{{ Execute a command, with specified files used for input/output */
PHP_FUNCTION(proc_open)
{
	zend_string *command_str;
	HashTable *command_ht;
	zval *descriptorspec, *pipes;       /* Mandatory arguments */
	char *cwd = NULL;                                /* Optional argument */
	size_t cwd_len = 0;                              /* Optional argument */
	zval *environment = NULL, *other_options = NULL; /* Optional arguments */

	char *command = NULL;
	php_process_env env;
	int ndesc = 0;
	int i;
	zval *descitem = NULL;
	zend_string *str_index;
	zend_ulong nindex;
	descriptorspec_item *descriptors = NULL;
#ifdef PHP_WIN32
	PROCESS_INFORMATION pi;
	HANDLE childHandle;
	STARTUPINFOW si;
	BOOL newprocok;
	DWORD dwCreateFlags = 0;
	UINT old_error_mode;
	char cur_cwd[MAXPATHLEN];
	wchar_t *cmdw = NULL, *cwdw = NULL, *envpw = NULL;
	size_t cmdw_len;
	int suppress_errors = 0;
	int bypass_shell = 0;
	int blocking_pipes = 0;
	int create_process_group = 0;
	int create_new_console = 0;
#else
	char **argv = NULL;
#endif
	int pty_master_fd = -1, pty_slave_fd = -1;
	php_process_id_t child;
	php_process_handle *proc;

	ZEND_PARSE_PARAMETERS_START(3, 6)
		Z_PARAM_ARRAY_HT_OR_STR(command_ht, command_str)
		Z_PARAM_ARRAY(descriptorspec)
		Z_PARAM_ZVAL(pipes)
		Z_PARAM_OPTIONAL
		Z_PARAM_STRING_OR_NULL(cwd, cwd_len)
		Z_PARAM_ARRAY_OR_NULL(environment)
		Z_PARAM_ARRAY_OR_NULL(other_options)
	ZEND_PARSE_PARAMETERS_END();

	memset(&env, 0, sizeof(env));

	if (command_ht) {
		uint32_t num_elems = zend_hash_num_elements(command_ht);
		if (num_elems == 0) {
			zend_argument_value_error(1, "must have at least one element");
			RETURN_THROWS();
		}

#ifdef PHP_WIN32
		/* Automatically bypass shell if command is given as an array */
		bypass_shell = 1;
		command = create_win_command_from_args(command_ht);
		if (!command) {
			RETURN_FALSE;
		}
#else
		command = get_command_from_array(command_ht, &argv, num_elems);
		if (command == NULL) {
			goto exit_fail;
		}
#endif
	} else {
		command = estrdup(ZSTR_VAL(command_str));
	}

#ifdef PHP_WIN32
	if (other_options) {
		suppress_errors      = get_option(other_options, "suppress_errors");
		/* TODO: Deprecate in favor of array command? */
		bypass_shell         = bypass_shell || get_option(other_options, "bypass_shell");
		blocking_pipes       = get_option(other_options, "blocking_pipes");
		create_process_group = get_option(other_options, "create_process_group");
		create_new_console   = get_option(other_options, "create_new_console");
	}
#endif

	if (environment) {
		env = _php_array_to_envp(environment);
	}

	descriptors = alloc_descriptor_array(descriptorspec);

	/* Walk the descriptor spec and set up files/pipes */
	ZEND_HASH_FOREACH_KEY_VAL(Z_ARRVAL_P(descriptorspec), nindex, str_index, descitem) {
		if (str_index) {
			zend_argument_value_error(2, "must be an integer indexed array");
			goto exit_fail;
		}

		descriptors[ndesc].index = (int)nindex;

		if (Z_TYPE_P(descitem) == IS_RESOURCE) {
			if (set_proc_descriptor_from_resource(descitem, &descriptors[ndesc], ndesc) == FAILURE) {
				goto exit_fail;
			}
		} else if (Z_TYPE_P(descitem) == IS_ARRAY) {
			if (set_proc_descriptor_from_array(descitem, descriptors, ndesc, (int)nindex,
				&pty_master_fd, &pty_slave_fd) == FAILURE) {
				goto exit_fail;
			}
		} else {
			zend_argument_value_error(2, "must only contain arrays and streams");
			goto exit_fail;
		}
		ndesc++;
	} ZEND_HASH_FOREACH_END();

#ifdef PHP_WIN32
	if (cwd == NULL) {
		char *getcwd_result = VCWD_GETCWD(cur_cwd, MAXPATHLEN);
		if (!getcwd_result) {
			php_error_docref(NULL, E_WARNING, "Cannot get current directory");
			goto exit_fail;
		}
		cwd = cur_cwd;
	}
	cwdw = php_win32_cp_any_to_w(cwd);
	if (!cwdw) {
		php_error_docref(NULL, E_WARNING, "CWD conversion failed");
		goto exit_fail;
	}

	init_startup_info(&si, descriptors, ndesc);
	init_process_info(&pi);

	if (suppress_errors) {
		old_error_mode = SetErrorMode(SEM_FAILCRITICALERRORS|SEM_NOGPFAULTERRORBOX);
	}

	dwCreateFlags = NORMAL_PRIORITY_CLASS;
	if(strcmp(sapi_module.name, "cli") != 0) {
		dwCreateFlags |= CREATE_NO_WINDOW;
	}
	if (create_process_group) {
		dwCreateFlags |= CREATE_NEW_PROCESS_GROUP;
	}
	if (create_new_console) {
		dwCreateFlags |= CREATE_NEW_CONSOLE;
	}
	envpw = php_win32_cp_env_any_to_w(env.envp);
	if (envpw) {
		dwCreateFlags |= CREATE_UNICODE_ENVIRONMENT;
	} else  {
		if (env.envp) {
			php_error_docref(NULL, E_WARNING, "ENV conversion failed");
			goto exit_fail;
		}
	}

	cmdw = php_win32_cp_conv_any_to_w(command, strlen(command), &cmdw_len);
	if (!cmdw) {
		php_error_docref(NULL, E_WARNING, "Command conversion failed");
		goto exit_fail;
	}

	if (!bypass_shell) {
		if (convert_command_to_use_shell(&cmdw, cmdw_len) == FAILURE) {
			goto exit_fail;
		}
	}
	newprocok = CreateProcessW(NULL, cmdw, &php_proc_open_security,
		&php_proc_open_security, TRUE, dwCreateFlags, envpw, cwdw, &si, &pi);

	if (suppress_errors) {
		SetErrorMode(old_error_mode);
	}

	if (newprocok == FALSE) {
		DWORD dw = GetLastError();
		close_all_descriptors(descriptors, ndesc);
		php_error_docref(NULL, E_WARNING, "CreateProcess failed, error code: %u", dw);
		goto exit_fail;
	}

	childHandle = pi.hProcess;
	child       = pi.dwProcessId;
	CloseHandle(pi.hThread);
#elif HAVE_FORK
	/* the Unix way */
	child = fork();

	if (child == 0) {
		/* This is the child process */

		if (close_parentends_of_pipes(descriptors, ndesc) == FAILURE) {
			/* We are already in child process and can't do anything to make
			 * `proc_open` return an error in the parent
			 * All we can do is exit with a non-zero (error) exit code */
			_exit(127);
		}

		if (cwd) {
			php_ignore_value(chdir(cwd));
		}

		if (argv) {
			/* execvpe() is non-portable, use environ instead. */
			if (env.envarray) {
				environ = env.envarray;
			}
			execvp(command, argv);
		} else {
			if (env.envarray) {
				execle("/bin/sh", "sh", "-c", command, NULL, env.envarray);
			} else {
				execl("/bin/sh", "sh", "-c", command, NULL);
			}
		}

		/* If execvp/execle/execl are successful, we will never reach here
		 * Display error and exit with non-zero (error) status code */
		php_error_docref(NULL, E_WARNING, "Exec failed: %s", strerror(errno));
		_exit(127);
	} else if (child < 0) {
		/* Failed to fork() */
		close_all_descriptors(descriptors, ndesc);
		php_error_docref(NULL, E_WARNING, "Fork failed: %s", strerror(errno));
		goto exit_fail;
	}
#else
# error You lose (configure should not have let you get here)
#endif

	/* We forked/spawned and this is the parent */

	pipes = zend_try_array_init(pipes);
	if (!pipes) {
		goto exit_fail;
	}

	proc = (php_process_handle*) emalloc(sizeof(php_process_handle));
	proc->command = command;
	proc->pipes = emalloc(sizeof(zend_resource *) * ndesc);
	proc->npipes = ndesc;
	proc->child = child;
#ifdef PHP_WIN32
	proc->childHandle = childHandle;
#endif
	proc->env = env;

	/* Clean up all the child ends and then open streams on the parent
	 *   ends, where appropriate */
	for (i = 0; i < ndesc; i++) {
		php_stream *stream = NULL;

		close_descriptor(descriptors[i].childend);

		if (descriptors[i].type == DESCRIPTOR_TYPE_PIPE) {
			char *mode_string = NULL;

			switch (descriptors[i].mode_flags) {
#ifdef PHP_WIN32
				case O_WRONLY|O_BINARY:
					mode_string = "wb";
					break;
				case O_RDONLY|O_BINARY:
					mode_string = "rb";
					break;
#endif
				case O_WRONLY:
					mode_string = "w";
					break;
				case O_RDONLY:
					mode_string = "r";
					break;
				case O_RDWR:
					mode_string = "r+";
					break;
			}

#ifdef PHP_WIN32
			stream = php_stream_fopen_from_fd(_open_osfhandle((zend_intptr_t)descriptors[i].parentend,
						descriptors[i].mode_flags), mode_string, NULL);
			php_stream_set_option(stream, PHP_STREAM_OPTION_PIPE_BLOCKING, blocking_pipes, NULL);
#else
			stream = php_stream_fopen_from_fd(descriptors[i].parentend, mode_string, NULL);
#endif
		} else if (descriptors[i].type == DESCRIPTOR_TYPE_SOCKET) {
			stream = php_stream_sock_open_from_socket((php_socket_t) descriptors[i].parentend, NULL);
		} else {
			proc->pipes[i] = NULL;
		}

		if (stream) {
			zval retfp;

			/* nasty hack; don't copy it */
			stream->flags |= PHP_STREAM_FLAG_NO_SEEK;

			php_stream_to_zval(stream, &retfp);
			add_index_zval(pipes, descriptors[i].index, &retfp);

			proc->pipes[i] = Z_RES(retfp);
			Z_ADDREF(retfp);
		}
	}

	if (1) {
		RETVAL_RES(zend_register_resource(proc, le_proc_open));
	} else {
exit_fail:
		_php_free_envp(env);
		if (command) {
			efree(command);
		}
		RETVAL_FALSE;
	}

#ifdef PHP_WIN32
	free(cwdw);
	free(cmdw);
	free(envpw);
#else
	efree_argv(argv);
#endif
#if HAVE_OPENPTY
	if (pty_master_fd != -1) {
		close(pty_master_fd);
	}
	if (pty_slave_fd != -1) {
		close(pty_slave_fd);
	}
#endif
	if (descriptors) {
		efree(descriptors);
	}
}
/* }}} */

#endif /* PHP_CAN_SUPPORT_PROC_OPEN */
