/*      $NetBSD: chown.c,v 1.12 2023/05/04 18:34:55 christos Exp $      */

/*
 * Copyright (c) 1988, 1993, 1994, 2003
 *      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/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1988, 1993, 1994, 2003\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)chown.c     8.8 (Berkeley) 4/4/94";
#else
__RCSID("$NetBSD: chown.c,v 1.12 2023/05/04 18:34:55 christos Exp $");
#endif
#endif /* not lint */

#include <sys/types.h>
#include <sys/stat.h>

#include <ctype.h>
#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <locale.h>
#include <fts.h>
#include <grp.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <getopt.h>

static void     a_gid(const char *);
static void     a_uid(const char *);
static id_t     id(const char *, const char *);
__dead static void      usage(void);

static uid_t uid;
static gid_t gid;
static int ischown;
static const char *myname;

struct option chown_longopts[] = {
        { "reference",          required_argument,      0,
                                                1 },
        { NULL,                 0,                      0,
                                                0 },
};

int
main(int argc, char **argv)
{
        FTS *ftsp;
        FTSENT *p;
        int Hflag, Lflag, Rflag, ch, fflag, fts_options, hflag, rval, vflag, dflag;
        char *cp, *reference;
        int (*change_owner)(const char *, uid_t, gid_t);

        setprogname(*argv);

        (void)setlocale(LC_ALL, "");

        myname = getprogname();
        ischown = (myname[2] == 'o');
        reference = NULL;

        Hflag = Lflag = Rflag = fflag = hflag = vflag = dflag = 0;
        while ((ch = getopt_long(argc, argv, "HLPRdfhv",
            chown_longopts, NULL)) != -1)
                switch (ch) {
                case 1:
                        reference = optarg;
                        break;
                case 'd':
                        dflag = 1;
                        break;
                case 'H':
                        Hflag = 1;
                        Lflag = 0;
                        break;
                case 'L':
                        Lflag = 1;
                        Hflag = 0;
                        break;
                case 'P':
                        Hflag = Lflag = 0;
                        break;
                case 'R':
                        Rflag = 1;
                        break;
                case 'f':
                        fflag = 1;
                        break;
                case 'h':
                        /*
                         * In System V the -h option causes chown/chgrp to
                         * change the owner/group of the symbolic link.
                         * 4.4BSD's symbolic links didn't have owners/groups,
                         * so it was an undocumented noop.
                         * In NetBSD 1.3, lchown(2) is introduced.
                         */
                        hflag = 1;
                        break;
                case 'v':
                        vflag = 1;
                        break;
                case '?':
                default:
                        usage();
                }
        argv += optind;
        argc -= optind;

        if (argc == 0 || (argc == 1 && reference == NULL))
                usage();

        fts_options = FTS_PHYSICAL;
        if (Rflag) {
                if (Hflag)
                        fts_options |= FTS_COMFOLLOW;
                if (Lflag) {
                        if (hflag)
                                errx(EXIT_FAILURE,
                                    "the -L and -h options "
                                    "may not be specified together.");
                        fts_options &= ~FTS_PHYSICAL;
                        fts_options |= FTS_LOGICAL;
                }
        } else if (!hflag)
                fts_options |= FTS_COMFOLLOW;

        uid = (uid_t)-1;
        gid = (gid_t)-1;
        if (reference == NULL) {
                if (ischown) {
                        if ((cp = strchr(*argv, ':')) != NULL) {
                                *cp++ = '\0';
                                a_gid(cp);
                        }
#ifdef SUPPORT_DOT
                        else if ((cp = strrchr(*argv, '.')) != NULL) {
                                if (uid_from_user(*argv, &uid) == -1) {
                                        *cp++ = '\0';
                                        a_gid(cp);
                                }
                        }
#endif
                        a_uid(*argv);
                } else
                        a_gid(*argv);
                argv++;
        } else {
                struct stat st;

                if (stat(reference, &st) == -1)
                        err(EXIT_FAILURE, "Cannot stat `%s'", reference);
                if (ischown)
                        uid = st.st_uid;
                gid = st.st_gid;
        }

        if ((ftsp = fts_open(argv, fts_options, NULL)) == NULL)
                err(EXIT_FAILURE, "fts_open");

        for (rval = EXIT_SUCCESS; (p = fts_read(ftsp)) != NULL;) {
                change_owner = chown;
                switch (p->fts_info) {
                case FTS_D:
                        if (!Rflag)             /* Change it at FTS_DP. */
                                fts_set(ftsp, p, FTS_SKIP);
                        continue;
                case FTS_DNR:                   /* Warn, chown, continue. */
                        warnx("%s: %s", p->fts_path, strerror(p->fts_errno));
                        rval = EXIT_FAILURE;
                        break;
                case FTS_ERR:                   /* Warn, continue. */
                case FTS_NS:
                        warnx("%s: %s", p->fts_path, strerror(p->fts_errno));
                        rval = EXIT_FAILURE;
                        continue;
                case FTS_SL:                    /* Ignore unless -h. */
                        /*
                         * All symlinks we found while doing a physical
                         * walk end up here.
                         */
                        if (!hflag)
                                continue;
                        /*
                         * Note that if we follow a symlink, fts_info is
                         * not FTS_SL but FTS_F or whatever.  And we should
                         * use lchown only for FTS_SL and should use chown
                         * for others.
                         */
                        change_owner = lchown;
                        break;
                case FTS_SLNONE:                /* Ignore. */
                        /*
                         * The only symlinks that end up here are ones that
                         * don't point to anything.  Note that if we are
                         * doing a physical walk, we never reach here unless
                         * we asked to follow explicitly.
                         */
                        continue;
                default:
                        break;
                }

                /*
                 * If dflag was set, and the owner and group are already
                 * set to the right values and the set-user-id and
                 * set-group-id bits are both already clear, skip any
                 * attempt to update.
                 */
                if (dflag &&
                    (uid == (uid_t)-1 || p->fts_statp->st_uid == uid) &&
                    (gid == (gid_t)-1 || p->fts_statp->st_gid == gid) &&
                    (p->fts_statp->st_mode & 07000) == 0)
                        continue;

                if ((*change_owner)(p->fts_accpath, uid, gid) && !fflag) {
                        warn("%s", p->fts_path);
                        rval = EXIT_FAILURE;
                } else {
                        if (vflag)
                                printf("%s\n", p->fts_path);
                }
        }
        if (errno)
                err(EXIT_FAILURE, "fts_read");
        exit(rval);
        /* NOTREACHED */
}

static void
a_gid(const char *s)
{
        struct group *gr;

        if (*s == '\0')                 /* Argument was "uid[:.]". */
                return;
        gr = *s == '#' ? NULL : getgrnam(s);
        if (gr == NULL)
                gid = id(s, "group");
        else
                gid = gr->gr_gid;
        return;
}

static void
a_uid(const char *s)
{
        if (*s == '\0')                 /* Argument was "[:.]gid". */
                return;
        if (*s == '#' || uid_from_user(s, &uid) == -1) {
                uid = id(s, "user");
        }
        return;
}

static id_t
id(const char *name, const char *type)
{
        id_t val;
        char *ep;

        errno = 0;
        if (*name == '#')
                name++;
        val = (id_t)strtoul(name, &ep, 10);
        if (errno)
                err(EXIT_FAILURE, "%s", name);
        if (*ep != '\0')
                errx(EXIT_FAILURE, "%s: invalid %s name", name, type);
        return (val);
}

static void
usage(void)
{

        (void)fprintf(stderr,
            "Usage: %s [-R [-H | -L | -P]] [-dfhv] %s file ...\n"
            "\t%s [-R [-H | -L | -P]] [-dfhv] --reference=rfile file ...\n",
            myname, ischown ? "owner:group|owner|:group" : "group",
            myname);
        exit(EXIT_FAILURE);
}