/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1983, 1992, 1993
 *      The Regents of the University of California.  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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 <sys/types.h>
#include <sys/stat.h>

#include <err.h>
#include <errno.h>
#include <libgen.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>

static int      build(char *, mode_t);
static void     usage(void);

static int      vflag;

int
main(int argc, char *argv[])
{
        int ch, exitval, success, pflag;
        mode_t omode;
        void *set = NULL;
        char *mode;

        omode = pflag = 0;
        mode = NULL;
        while ((ch = getopt(argc, argv, "m:pv")) != -1)
                switch(ch) {
                case 'm':
                        mode = optarg;
                        break;
                case 'p':
                        pflag = 1;
                        break;
                case 'v':
                        vflag = 1;
                        break;
                case '?':
                default:
                        usage();
                }

        argc -= optind;
        argv += optind;
        if (argv[0] == NULL)
                usage();

        if (mode == NULL) {
                omode = S_IRWXU | S_IRWXG | S_IRWXO;
        } else {
                if ((set = setmode(mode)) == NULL)
                        errx(1, "invalid file mode: %s", mode);
                omode = getmode(set, S_IRWXU | S_IRWXG | S_IRWXO);
                free(set);
        }

        for (exitval = 0; *argv != NULL; ++argv) {
                if (pflag) {
                        success = build(*argv, omode);
                } else if (mkdir(*argv, omode) < 0) {
                        if (errno == ENOTDIR || errno == ENOENT)
                                warn("%s", dirname(*argv));
                        else
                                warn("%s", *argv);
                        success = 0;
                } else {
                        success = 1;
                        if (vflag)
                                (void)printf("%s\n", *argv);
                }
                if (!success)
                        exitval = 1;
                /*
                 * The mkdir() and umask() calls both honor only the low
                 * nine bits, so if you try to set a mode including the
                 * sticky, setuid, setgid bits you lose them.  Don't do
                 * this unless the user has specifically requested a mode,
                 * as chmod will (obviously) ignore the umask.  Do this
                 * on newly created directories only.
                 */
                if (success == 1 && mode != NULL && chmod(*argv, omode) == -1) {
                        warn("%s", *argv);
                        exitval = 1;
                }
        }
        exit(exitval);
}


/*
 * Returns 1 if a directory has been created,
 * 2 if it already existed, and 0 on failure.
 */
static int
build(char *path, mode_t omode)
{
        struct stat sb;
        mode_t numask, oumask;
        int first, last, retval;
        char *p;

        p = path;
        oumask = 0;
        retval = 1;
        if (p[0] == '/')                /* Skip leading '/'. */
                ++p;
        for (first = 1, last = 0; !last ; ++p) {
                if (p[0] == '\0')
                        last = 1;
                else if (p[0] != '/')
                        continue;
                *p = '\0';
                if (!last && p[1] == '\0')
                        last = 1;
                if (first) {
                        /*
                         * POSIX 1003.2:
                         * For each dir operand that does not name an existing
                         * directory, effects equivalent to those caused by the
                         * following command shall occur:
                         *
                         * mkdir -p -m $(umask -S),u+wx $(dirname dir) &&
                         *    mkdir [-m mode] dir
                         *
                         * We change the user's umask and then restore it,
                         * instead of doing chmod's.
                         */
                        oumask = umask(0);
                        numask = oumask & ~(S_IWUSR | S_IXUSR);
                        (void)umask(numask);
                        first = 0;
                }
                if (last)
                        (void)umask(oumask);
                if (mkdir(path, last ? omode : S_IRWXU | S_IRWXG | S_IRWXO) < 0) {
                        if (errno == EEXIST || errno == EISDIR) {
                                if (stat(path, &sb) < 0) {
                                        warn("%s", path);
                                        retval = 0;
                                        break;
                                } else if (!S_ISDIR(sb.st_mode)) {
                                        if (last)
                                                errno = EEXIST;
                                        else
                                                errno = ENOTDIR;
                                        warn("%s", path);
                                        retval = 0;
                                        break;
                                }
                                if (last)
                                        retval = 2;
                        } else {
                                warn("%s", path);
                                retval = 0;
                                break;
                        }
                } else if (vflag)
                        printf("%s\n", path);
                if (!last)
                    *p = '/';
        }
        if (!first && !last)
                (void)umask(oumask);
        return (retval);
}

static void
usage(void)
{

        (void)fprintf(stderr,
            "usage: mkdir [-pv] [-m mode] directory_name ...\n");
        exit (EX_USAGE);
}