/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (C) 1996
 *	David L. Nugent.  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 DAVID L. NUGENT 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 DAVID L. NUGENT 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 <dirent.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>

#include "pw.h"

void
copymkdir(int rootfd, char const *dir, int skelfd, mode_t mode, uid_t uid,
    gid_t gid, int flags)
{
	char		*p, lnk[MAXPATHLEN];
	int		len, srcfd, destfd;
	ssize_t		sz;
	struct stat     st;
	struct dirent  *e;
	DIR		*d;
	mode_t		pumask;

	if (*dir == '/')
		dir++;

	pumask = umask(0);
	umask(pumask);

	if (mkdirat(rootfd, dir, mode) != 0) {

		if (errno != EEXIST) {
			warn("mkdir(%s)", dir);
			return;
		}

		if (fchmodat(rootfd, dir, mode & ~pumask,
		    AT_SYMLINK_NOFOLLOW) == -1)
			warn("chmod(%s)", dir);
	}
	if (fchownat(rootfd, dir, uid, gid, AT_SYMLINK_NOFOLLOW) == -1)
		warn("chown(%s)", dir);
	if (flags > 0 && chflagsat(rootfd, dir, flags,
	    AT_SYMLINK_NOFOLLOW) == -1)
		warn("chflags(%s)", dir);
	metalog_emit(dir, (mode | S_IFDIR) & ~pumask, uid, gid, flags);

	if (skelfd == -1)
		return;

	if ((d = fdopendir(skelfd)) == NULL) {
		close(skelfd);
		return;
	}

	while ((e = readdir(d)) != NULL) {
		char path[MAXPATHLEN];

		if (strcmp(e->d_name, ".") == 0 || strcmp(e->d_name, "..") == 0)
			continue;

		p = e->d_name;
		if (fstatat(skelfd, p, &st, AT_SYMLINK_NOFOLLOW) == -1)
			continue;

		if (strncmp(p, "dot.", 4) == 0)	/* Conversion */
			p += 3;
		(void)snprintf(path, sizeof(path), "%s/%s", dir, p);

		if (S_ISDIR(st.st_mode)) {
			int fd;

			fd = openat(skelfd, e->d_name, O_DIRECTORY);
			if (fd == -1) {
				warn("openat(%s)", e->d_name);
				continue;
			}
			copymkdir(rootfd, path, fd, st.st_mode & _DEF_DIRMODE,
			    uid, gid, st.st_flags);
			continue;
		}

		if (S_ISLNK(st.st_mode) &&
		    (len = readlinkat(skelfd, e->d_name, lnk, sizeof(lnk) - 1))
		    != -1) {
			lnk[len] = '\0';
			if (symlinkat(lnk, rootfd, path) != 0)
				warn("symlink(%s)", path);
			else if (fchownat(rootfd, path, uid, gid,
			    AT_SYMLINK_NOFOLLOW) != 0)
				warn("chown(%s)", path);
			metalog_emit_symlink(path, lnk, st.st_mode & ~pumask,
			    uid, gid);
			continue;
		}

		if (!S_ISREG(st.st_mode))
			continue;

		if ((srcfd = openat(skelfd, e->d_name, O_RDONLY)) == -1)
			continue;
		destfd = openat(rootfd, path, O_RDWR | O_CREAT | O_EXCL,
		    st.st_mode);
		if (destfd == -1) {
			close(srcfd);
			continue;
		}

		do {
			sz = copy_file_range(srcfd, NULL, destfd, NULL,
			    SSIZE_MAX, 0);
		} while (sz > 0);
		if (sz < 0)
			warn("copy_file_range");

		close(srcfd);
		/*
		 * Propagate special filesystem flags
		 */
		if (fchown(destfd, uid, gid) != 0)
			warn("chown(%s)", p);
		if (fchflags(destfd, st.st_flags) != 0)
			warn("chflags(%s)", p);
		metalog_emit(path, st.st_mode & ~pumask, uid, gid, st.st_flags);
		close(destfd);
	}
	closedir(d);
}