/* SPDX-License-Identifier: GPL-2.0 */

#include <stdio.h>
#include <unistd.h>
#include <assert.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/stat.h>
#include <fcntl.h>

#include "gcc-compat.h"
#include "err.h"
#include "str.h"
#include "file.h"

/*
 * Call a function for each subdirectory of the current working directory.
 *
 * For each top-level directory under dirname, the supplied callback function
 * is called, passing the full path to the subdirectory and the private_data
 * pointer.
 *
 * If the callback returns a negative error value, the loop is terminated and
 * that negative value is returned to the caller. If the iteration completes
 * with no errors, the function returns non-negative.
 */
int for_each_subdir(int (*func)(const char *, void *), void *private_data)
{
	struct dirent *entry;
	int ret;
	DIR *dir = opendir(".");

	if (!dir)
		return -ERRNO_TO_DSS_ERROR(errno);
	while ((entry = readdir(dir))) {
		mode_t m;
		struct stat s;

		if (!strcmp(entry->d_name, "."))
			continue;
		if (!strcmp(entry->d_name, ".."))
			continue;
		ret = lstat(entry->d_name, &s) == -1;
		if (ret == -1) {
			ret = -ERRNO_TO_DSS_ERROR(errno);
			goto out;
		}
		m = s.st_mode;
		if (!S_ISDIR(m))
			continue;
		ret = func(entry->d_name, private_data);
		if (ret < 0)
			goto out;
	}
	ret = 1;
out:
	closedir(dir);
	return ret;
}

/* Set a file descriptor to non-blocking mode. */
__must_check int mark_fd_nonblocking(int fd)
{
	int flags = fcntl(fd, F_GETFL);
	if (flags < 0)
		return -ERRNO_TO_DSS_ERROR(errno);
	flags = fcntl(fd, F_SETFL, ((long)flags) | O_NONBLOCK);
	if (flags < 0)
		return -ERRNO_TO_DSS_ERROR(errno);
	return 1;
}

/*
 * Call select(2) with no exceptfds and start over if the call was interrupted
 * by a signal. All arguments are passed verbatim to select(2). Returns the
 * return value of the underlying select call on success, a negative error code
 * on error.
 */
int dss_select(int n, fd_set *readfds, fd_set *writefds,
		struct timeval *timeout_tv)
{
	int ret, err;
	do {
		ret = select(n, readfds, writefds, NULL, timeout_tv);
		err = errno;
	} while (ret < 0 && err == EINTR);
	if (ret < 0)
		return -ERRNO_TO_DSS_ERROR(errno);
	return ret;
}