/*-
 * 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);
}