/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1999, 2001, 2002 Robert N M Watson
 * All rights reserved.
 *
 * This software was developed by Robert Watson for the TrustedBSD Project.
 *
 * 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 THE AUTHOR 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 AUTHOR 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.
 */
/*
 * getfacl -- POSIX.1e utility to extract ACLs from files and directories
 * and send the results to stdout
 */

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

#include <err.h>
#include <errno.h>
#include <getopt.h>
#include <grp.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

static int more_than_one = 0;

static const struct option long_options[] =
{
        { "default",            no_argument,    NULL,   'd' },
        { "numeric",            no_argument,    NULL,   'n' },
        { "omit-header",        no_argument,    NULL,   'q' },
        { "skip-base",          no_argument,    NULL,   's' },
        { NULL,                 no_argument,    NULL,   0 },
};

static void
usage(void)
{

        fprintf(stderr, "getfacl [-dhnqv] [file ...]\n");
}

static char *
getuname(uid_t uid)
{
        struct passwd *pw;
        static char uids[10];

        if ((pw = getpwuid(uid)) == NULL) {
                (void)snprintf(uids, sizeof(uids), "%u", uid);
                return (uids);
        } else
                return (pw->pw_name);
}

static char *
getgname(gid_t gid)
{
        struct group *gr;
        static char gids[10];

        if ((gr = getgrgid(gid)) == NULL) {
                (void)snprintf(gids, sizeof(gids), "%u", gid);
                return (gids);
        } else
                return (gr->gr_name);
}

static int
print_acl(char *path, acl_type_t type, int hflag, int iflag, int nflag,
    int qflag, int vflag, int sflag)
{
        struct stat     sb;
        acl_t   acl;
        char    *acl_text;
        int     error, flags = 0, ret;

        if (hflag)
                error = lstat(path, &sb);
        else
                error = stat(path, &sb);
        if (error == -1) {
                warn("%s: stat() failed", path);
                return(-1);
        }

        if (hflag)
                ret = lpathconf(path, _PC_ACL_NFS4);
        else
                ret = pathconf(path, _PC_ACL_NFS4);
        if (ret > 0) {
                if (type == ACL_TYPE_DEFAULT) {
                        warnx("%s: there are no default entries in NFSv4 ACLs",
                            path);
                        return (-1);
                }
                type = ACL_TYPE_NFS4;
        } else if (ret < 0 && errno != EINVAL) {
                warn("%s: pathconf(..., _PC_ACL_NFS4) failed", path);
                return (-1);
        }

        if (hflag)
                acl = acl_get_link_np(path, type);
        else
                acl = acl_get_file(path, type);

        if (!acl && errno != EOPNOTSUPP) {
                warn("%s", path);
                return(-1);
        }

        if (sflag) {
                int trivial;

                /*
                 * With the -s flag, we shouldn't synthesize a trivial ACL if
                 * they aren't supported as we do below.
                 */
                if (!acl)
                        return(0);

                /*
                 * We also shouldn't render anything for this path if it's a
                 * trivial ACL.  If we error out, we'll issue a warning but
                 * proceed with this file to err on the side of caution.
                 */
                error = acl_is_trivial_np(acl, &trivial);
                if (error != 0) {
                        warn("%s: acl_is_trivial_np failed", path);
                } else if (trivial) {
                        (void)acl_free(acl);
                        return(0);
                }
        }

        if (more_than_one)
                printf("\n");
        else
                more_than_one++;
        if (!qflag)
                printf("# file: %s\n# owner: %s\n# group: %s\n", path,
                    getuname(sb.st_uid), getgname(sb.st_gid));

        if (!acl) {
                if (type == ACL_TYPE_DEFAULT)
                        return(0);
                acl = acl_from_mode_np(sb.st_mode);
                if (!acl) {
                        warn("%s: acl_from_mode() failed", path);
                        return(-1);
                }
        }

        if (iflag)
                flags |= ACL_TEXT_APPEND_ID;

        if (nflag)
                flags |= ACL_TEXT_NUMERIC_IDS;

        if (vflag)
                flags |= ACL_TEXT_VERBOSE;

        acl_text = acl_to_text_np(acl, 0, flags);
        if (!acl_text) {
                warn("%s: acl_to_text_np() failed", path);
                (void)acl_free(acl);
                return(-1);
        }

        printf("%s", acl_text);

        (void)acl_free(acl);
        (void)acl_free(acl_text);

        return(0);
}

static int
print_acl_from_stdin(acl_type_t type, int hflag, int iflag, int nflag,
    int qflag, int vflag, int sflag)
{
        char    *p, pathname[PATH_MAX];
        int     carried_error = 0;

        while (fgets(pathname, (int)sizeof(pathname), stdin)) {
                if ((p = strchr(pathname, '\n')) != NULL)
                        *p = '\0';
                if (print_acl(pathname, type, hflag, iflag, nflag,
                    qflag, vflag, sflag) == -1) {
                        carried_error = -1;
                }
        }

        return(carried_error);
}

int
main(int argc, char *argv[])
{
        acl_type_t      type = ACL_TYPE_ACCESS;
        int     carried_error = 0;
        int     ch, error, i;
        int     hflag, iflag, qflag, nflag, sflag, vflag;

        hflag = 0;
        iflag = 0;
        qflag = 0;
        nflag = 0;
        sflag = 0;
        vflag = 0;
        while ((ch = getopt_long(argc, argv, "+dhinqsv", long_options,
            NULL)) != -1)
                switch(ch) {
                case 'd':
                        type = ACL_TYPE_DEFAULT;
                        break;
                case 'h':
                        hflag = 1;
                        break;
                case 'i':
                        iflag = 1;
                        break;
                case 'n':
                        nflag = 1;
                        break;
                case 'q':
                        qflag = 1;
                        break;
                case 's':
                        sflag = 1;
                        break;
                case 'v':
                        vflag = 1;
                        break;
                default:
                        usage();
                        return(-1);
                }
        argc -= optind;
        argv += optind;

        if (argc == 0) {
                error = print_acl_from_stdin(type, hflag, iflag, nflag,
                    qflag, vflag, sflag);
                return(error ? 1 : 0);
        }

        for (i = 0; i < argc; i++) {
                if (!strcmp(argv[i], "-")) {
                        error = print_acl_from_stdin(type, hflag, iflag, nflag,
                            qflag, vflag, sflag);
                        if (error == -1)
                                carried_error = -1;
                } else {
                        error = print_acl(argv[i], type, hflag, iflag, nflag,
                            qflag, vflag, sflag);
                        if (error == -1)
                                carried_error = -1;
                }
        }

        return(carried_error ? 1 : 0);
}