cmd/chmod/chmod.c

	chmod.c revision da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T         */
/*    All Rights Reserved                       */
/*                                  */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * chmod option mode files
 * where
 *  mode is [ugoa][+-=][rwxXlstugo] or an octal number
 *  mode is [<+|->A[# <number] ]<aclspec>
 *  mode is S<attrspec>
 *  option is -R, -f, and -@
 */

/*
 *  Note that many convolutions are necessary
 *  due to the re-use of bits between locking
 *  and setgid
 */

#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <locale.h>
#include <string.h> /* strerror() */
#include <stdarg.h>
#include <limits.h>
#include <ctype.h>
#include <errno.h>
#include <sys/acl.h>
#include <aclutils.h>
#include <libnvpair.h>
#include <libcmdutils.h>
#include <libgen.h>
#include <attr.h>

static int  rflag;
static int  fflag;

extern int  optind;
extern int  errno;

static int  mac;        /* Alternate to argc (for parseargs) */
static char **mav;      /* Alternate to argv (for parseargs) */

static char *ms;        /* Points to the mode argument */

#define ACL_ADD         1
#define ACL_DELETE      2
#define ACL_SLOT_DELETE     3
#define ACL_REPLACE     4
#define ACL_STRIP       5

#define LEFTBRACE   '{'
#define RIGHTBRACE  '}'
#define A_SEP       ','
#define A_SEP_TOK   ","

#define A_COMPACT_TYPE  'c'
#define A_VERBOSE_TYPE  'v'
#define A_ALLATTRS_TYPE 'a'

#define A_SET_OP    '+'
#define A_INVERSE_OP    '-'
#define A_REPLACE_OP    '='
#define A_UNDEF_OP  '\0'

#define A_SET_TEXT  "set"
#define A_INVERSE_TEXT  "clear"

#define A_SET_VAL   B_TRUE
#define A_CLEAR_VAL B_FALSE

#define ATTR_OPTS   0
#define ATTR_NAMES  1

#define sec_acls    secptr.acls
#define sec_attrs   secptr.attrs

typedef struct acl_args {
    acl_t   *acl_aclp;
    int acl_slot;
    int acl_action;
} acl_args_t;

typedef enum {
    SEC_ACL,
    SEC_ATTR
} chmod_sec_t;

typedef struct {
    chmod_sec_t     sec_type;
    union {
        acl_args_t  *acls;
        nvlist_t    *attrs;
    } secptr;
} sec_args_t;

typedef struct attr_name {
    char            *name;
    struct attr_name    *next;
} attr_name_t;


extern mode_t newmode_common(char *ms, mode_t new_mode, mode_t umsk,
    char *file, char *path, o_mode_t *group_clear_bits,
    o_mode_t *group_set_bits);

static int chmodr(char *dir, char *path, mode_t mode, mode_t umsk,
    sec_args_t *secp, attr_name_t *attrname);
static int doacl(char *file, struct stat *st, acl_args_t *aclp);
static int dochmod(char *name, char *path, mode_t umsk, sec_args_t *secp,
    attr_name_t *attrnames);
static void handle_acl(char *name, o_mode_t group_clear_bits,
    o_mode_t group_set_bits);
void errmsg(int severity, int code, char *format, ...);
static void free_attr_names(attr_name_t *attrnames);
static void parseargs(int ac, char *av[]);
static int parse_acl_args(char *arg, sec_args_t **sec_args);
static int parse_attr_args(char *arg, sec_args_t **sec_args);
static void print_attrs(int flag);
static int set_attrs(char *file, attr_name_t *attrnames, nvlist_t *attr_nvlist);
static void usage(void);

int
main(int argc, char *argv[])
{
    int     i, c;
    int     status = 0;
    mode_t      umsk;
    sec_args_t  *sec_args = NULL;
    attr_name_t *attrnames = NULL;
    attr_name_t *attrend = NULL;
    attr_name_t *tattr;

    (void) setlocale(LC_ALL, "");
#if !defined(TEXT_DOMAIN)   /* Should be defined by cc -D */
#define TEXT_DOMAIN "SYS_TEST"  /* Use this only if it weren't */
#endif
    (void) textdomain(TEXT_DOMAIN);

    parseargs(argc, argv);

    while ((c = getopt(mac, mav, "Rf@:")) != EOF) {
        switch (c) {
        case 'R':
            rflag++;
            break;
        case 'f':
            fflag++;
            break;
        case '@':
            if (((tattr = malloc(sizeof (attr_name_t))) == NULL) ||
                ((tattr->name = strdup(optarg)) == NULL)) {
                perror("chmod");
                exit(2);
            }
            if (attrnames == NULL) {
                attrnames = tattr;
                attrnames->next = NULL;
            } else {
                attrend->next = tattr;
            }
            attrend = tattr;
            break;
        case '?':
            usage();
            exit(2);
        }
    }

    /*
     * Check for sufficient arguments
     * or a usage error.
     */

    mac -= optind;
    mav += optind;
    if ((mac >= 2) && (mav[0][0] == 'A')) {
        if (attrnames != NULL) {
            free_attr_names(attrnames);
            attrnames = NULL;
        }
        if (parse_acl_args(*mav, &sec_args)) {
            usage();
            exit(2);
        }
    } else if ((mac >= 2) && (mav[0][0] == 'S')) {
        if (parse_attr_args(*mav, &sec_args)) {
            usage();
            exit(2);

        /* A no-op attribute operation was specified. */
        } else if (sec_args->sec_attrs == NULL) {
            exit(0);
        }
    } else {
        if (mac < 2) {
            usage();
            exit(2);
        }
        if (attrnames != NULL) {
            free_attr_names(attrnames);
            attrnames = NULL;
        }
    }

    ms = mav[0];

    umsk = umask(0);
    (void) umask(umsk);

    for (i = 1; i < mac; i++) {
        status += dochmod(mav[i], mav[i], umsk, sec_args, attrnames);
    }

    return (fflag ? 0 : status);
}

static void
free_attr_names(attr_name_t *attrnames)
{
    attr_name_t *attrnamesptr = attrnames;
    attr_name_t *tptr;

    while (attrnamesptr != NULL) {
        tptr = attrnamesptr->next;
        if (attrnamesptr->name != NULL) {
            free(attrnamesptr->name);
        }
        attrnamesptr = tptr;
    }
}

static int
dochmod(char *name, char *path, mode_t umsk, sec_args_t *secp,
    attr_name_t *attrnames)
{
    static struct stat st;
    int linkflg = 0;
    o_mode_t    group_clear_bits, group_set_bits;

    if (lstat(name, &st) < 0) {
        errmsg(2, 0, gettext("can't access %s\n"), path);
        return (1);
    }

    if ((st.st_mode & S_IFMT) == S_IFLNK) {
        linkflg = 1;
        if (stat(name, &st) < 0) {
            errmsg(2, 0, gettext("can't access %s\n"), path);
            return (1);
        }
    }

    /* Do not recurse if directory is object of symbolic link */
    if (rflag && ((st.st_mode & S_IFMT) == S_IFDIR) && !linkflg) {
        return (chmodr(name, path, st.st_mode, umsk, secp, attrnames));
    }

    if (secp != NULL) {
        if (secp->sec_type == SEC_ACL) {
            return (doacl(name, &st, secp->sec_acls));
        } else if (secp->sec_type == SEC_ATTR) {
            return (set_attrs(name, attrnames, secp->sec_attrs));
        } else {
            return (1);
        }
    } else {
        if (chmod(name, newmode_common(ms, st.st_mode, umsk, name, path,
            &group_clear_bits, &group_set_bits)) == -1) {
            errmsg(2, 0, gettext("can't change %s\n"), path);
            return (1);
        }
    }

    /*
     * If the group permissions of the file are being modified,
     * make sure that the file's ACL (if it has one) is
     * modified also, since chmod is supposed to apply group
     * permissions changes to both the acl mask and the
     * general group permissions.
     */
    if (group_clear_bits || group_set_bits)
        handle_acl(name, group_clear_bits, group_set_bits);

    return (0);
}

static int
chmodr(char *dir, char *path,  mode_t mode, mode_t umsk, sec_args_t *secp,
    attr_name_t *attrnames)
{

    DIR *dirp;
    struct dirent *dp;
    char savedir[PATH_MAX];         /* dir name to restore */
    char currdir[PATH_MAX+1];       /* current dir name + '/' */
    char parentdir[PATH_MAX+1];     /* parent dir name  + '/' */
    int ecode;
    struct stat st;
    o_mode_t    group_clear_bits, group_set_bits;

    if (getcwd(savedir, PATH_MAX) == 0)
        errmsg(2, 255, gettext("chmod: could not getcwd %s\n"),
            savedir);

    /*
     * Change what we are given before doing it's contents
     */
    if (secp != NULL) {
        if (lstat(dir, &st) < 0) {
            errmsg(2, 0, gettext("can't access %s\n"), path);
            return (1);
        }
        if (secp->sec_type == SEC_ACL) {
            if (doacl(dir, &st, secp->sec_acls) != 0)
                return (1);
        } else if (secp->sec_type == SEC_ATTR) {
            if (set_attrs(dir, attrnames, secp->sec_attrs) != 0) {
                return (1);
            }
        } else {
            return (1);
        }
    } else if (chmod(dir, newmode_common(ms, mode, umsk, dir, path,
        &group_clear_bits, &group_set_bits)) < 0) {
        errmsg(2, 0, gettext("can't change %s\n"), path);
        return (1);
    }

    /*
     * If the group permissions of the file are being modified,
     * make sure that the file's ACL (if it has one) is
     * modified also, since chmod is supposed to apply group
     * permissions changes to both the acl mask and the
     * general group permissions.
     */

    if (secp != NULL) {
        /* only necessary when not setting ACL or system attributes */
        if (group_clear_bits || group_set_bits)
            handle_acl(dir, group_clear_bits, group_set_bits);
    }

    if (chdir(dir) < 0) {
        errmsg(2, 0, "%s/%s: %s\n", savedir, dir, strerror(errno));
        return (1);
    }
    if ((dirp = opendir(".")) == NULL) {
        errmsg(2, 0, "%s\n", strerror(errno));
        return (1);
    }
    ecode = 0;

    /*
     * Save parent directory path before recursive chmod.
     * We'll need this for error printing purposes. Add
     * a trailing '/' to the path except in the case where
     * the path is just '/'
     */

    if (strlcpy(parentdir, path, PATH_MAX + 1) >= PATH_MAX + 1) {
        errmsg(2, 0, gettext("directory path name too long: %s\n"),
            path);
        return (1);
    }
    if (strcmp(path, "/") != 0)
        if (strlcat(parentdir, "/", PATH_MAX + 1) >= PATH_MAX + 1) {
            errmsg(2, 0,
                gettext("directory path name too long: %s/\n"),
                parentdir);
            return (1);
        }


    for (dp = readdir(dirp); dp != NULL; dp = readdir(dirp))  {

        if (strcmp(dp->d_name, ".") == 0 || /* skip . and .. */
            strcmp(dp->d_name, "..") == 0) {
            continue;
        }
        if (strlcpy(currdir, parentdir, PATH_MAX + 1) >= PATH_MAX + 1) {
            errmsg(2, 0,
                gettext("directory path name too long: %s\n"),
                parentdir);
            return (1);
        }
        if (strlcat(currdir, dp->d_name, PATH_MAX + 1)
            >= PATH_MAX + 1) {
            errmsg(2, 0,
                gettext("directory path name too long: %s%s\n"),
                currdir, dp->d_name);
            return (1);
        }
        ecode += dochmod(dp->d_name, currdir, umsk, secp, attrnames);
    }
    (void) closedir(dirp);
    if (chdir(savedir) < 0) {
        errmsg(2, 255, gettext("can't change back to %s\n"), savedir);
    }
    return (ecode ? 1 : 0);
}

/* PRINTFLIKE3 */
void
errmsg(int severity, int code, char *format, ...)
{
    va_list ap;
    static char *msg[] = {
    "",
    "ERROR",
    "WARNING",
    ""
    };

    va_start(ap, format);

    /*
     * Always print error message if this is a fatal error (code == 0);
     * otherwise, print message if fflag == 0 (no -f option specified)
     */
    if (!fflag || (code != 0)) {
        (void) fprintf(stderr,
            "chmod: %s: ", gettext(msg[severity]));
        (void) vfprintf(stderr, format, ap);
    }

    va_end(ap);

    if (code != 0)
        exit(fflag ? 0 : code);
}

static void
usage(void)
{
    (void) fprintf(stderr, gettext(
        "usage:\tchmod [-fR] <absolute-mode> file ...\n"));

    (void) fprintf(stderr, gettext(
        "\tchmod [-fR] [-@ attribute] ... "
        "S<attribute-operation> file ...\n"));

    (void) fprintf(stderr, gettext(
        "\tchmod [-fR] <ACL-operation> file ...\n"));

    (void) fprintf(stderr, gettext(
        "\tchmod [-fR] <symbolic-mode-list> file ...\n\n"));

    (void) fprintf(stderr, gettext(
        "where \t<symbolic-mode-list> is a comma-separated list of\n"));
    (void) fprintf(stderr, gettext(
        "\t[ugoa]{+|-|=}[rwxXlstugo]\n\n"));

    (void) fprintf(stderr, gettext(
        "where \t<attribute-operation> is a comma-separated list of\n"
        "\tone or more of the following\n"));
    (void) fprintf(stderr, gettext(
        "\t[+|-|=]c[<compact-attribute-list>|{<compact-attribute-list>}]\n"
        "\t[+|-|=]v[<verbose-attribute-setting>|"
        "\'{\'<verbose-attribute-setting-list>\'}\']\n"
        "\t[+|-|=]a\n"));
    (void) fprintf(stderr, gettext(
        "where \t<compact-attribute-list> is a list of zero or more of\n"));
    print_attrs(ATTR_OPTS);
    (void) fprintf(stderr, gettext(
        "where \t<verbose-attribute-setting> is one of\n"));
    print_attrs(ATTR_NAMES);
    (void) fprintf(stderr, gettext(
        "\tand can be, optionally, immediately preceded by \"no\"\n\n"));

    (void) fprintf(stderr, gettext(
        "where \t<ACL-operation> is one of the following\n"));
    (void) fprintf(stderr, gettext("\tA-<acl_specification>\n"));
    (void) fprintf(stderr, gettext("\tA[number]-\n"));
    (void) fprintf(stderr, gettext(
        "\tA[number]{+|=}<acl_specification>\n"));
    (void) fprintf(stderr, gettext(
        "where \t<acl-specification> is a comma-separated list of ACEs\n"));
}

/*
 *  parseargs - generate getopt-friendly argument list for backwards
 *      compatibility with earlier Solaris usage (eg, chmod -w
 *      foo).
 *
 *  assumes the existence of a static set of alternates to argc and argv,
 *  (namely, mac, and mav[]).
 *
 */

static void
parseargs(int ac, char *av[])
{
    int i;          /* current argument         */
    int fflag;      /* arg list contains "--"       */
    size_t mav_num;     /* number of entries in mav[]       */

    /*
     * We add an extra argument slot, in case we need to jam a "--"
     * argument into the list.
     */

    mav_num = (size_t)ac+2;

    if ((mav = calloc(mav_num, sizeof (char *))) == NULL) {
        perror("chmod");
        exit(2);
    }

    /* scan for the use of "--" in the argument list */

    for (fflag = i = 0; i < ac; i ++) {
        if (strcmp(av[i], "--") == 0)
            fflag = 1;
    }

    /* process the arguments */

    for (i = mac = 0;
        (av[i] != (char *)NULL) && (av[i][0] != (char)NULL);
        i++) {
        if (!fflag && av[i][0] == '-') {
            /*
             *  If there is not already a "--" argument specified,
             *  and the argument starts with '-' but does not
             *  contain any of the official option letters, then it
             *  is probably a mode argument beginning with '-'.
             *  Force a "--" into the argument stream in front of
             *  it.
             */

            if ((strchr(av[i], 'R') == NULL &&
                strchr(av[i], 'f') == NULL) &&
                strchr(av[i], '@') == NULL) {
                if ((mav[mac++] = strdup("--")) == NULL) {
                    perror("chmod");
                    exit(2);
                }
            }
        }

        if ((mav[mac++] = strdup(av[i])) == NULL) {
            perror("chmod");
            exit(2);
        }
    }

    mav[mac] = (char *)NULL;
}

static int
parse_acl_args(char *arg, sec_args_t **sec_args)
{
    acl_t *new_acl = NULL;
    int slot;
    int len;
    int action;
    acl_args_t *new_acl_args;
    char *acl_spec = NULL;
    char *end;

    if (arg[0] != 'A')
        return (1);

    slot = strtol(&arg[1], &end, 10);

    len = strlen(arg);
    switch (*end) {
    case '+':
        action = ACL_ADD;
        acl_spec = ++end;
        break;
    case '-':
        if (len == 2 && arg[0] == 'A' && arg[1] == '-')
            action = ACL_STRIP;
        else
            action = ACL_DELETE;
        if (action != ACL_STRIP) {
            acl_spec = ++end;
            if (acl_spec[0] == '\0') {
                action = ACL_SLOT_DELETE;
                acl_spec = NULL;
            } else if (arg[1] != '-')
                return (1);
        }
        break;
    case '=':
        /*
         * Was slot specified?
         */
        if (arg[1] == '=')
            slot = -1;
        action = ACL_REPLACE;
        acl_spec = ++end;
        break;
    default:
        return (1);
    }

    if ((action == ACL_REPLACE || action == ACL_ADD) && acl_spec[0] == '\0')
        return (1);

    if (acl_spec) {
        if (acl_parse(acl_spec, &new_acl)) {
            exit(1);
        }
    }

    new_acl_args = malloc(sizeof (acl_args_t));
    if (new_acl_args == NULL)
        return (1);

    new_acl_args->acl_aclp = new_acl;
    new_acl_args->acl_slot = slot;
    new_acl_args->acl_action = action;

    if ((*sec_args = malloc(sizeof (sec_args_t))) == NULL) {
        perror("chmod");
        exit(2);
    }
    (*sec_args)->sec_type = SEC_ACL;
    (*sec_args)->sec_acls = new_acl_args;

    return (0);
}

/*
 * This function is called whenever the group permissions of a file
 * is being modified.  According to the chmod(1) manpage, any
 * change made to the group permissions must be applied to both
 * the acl mask and the acl's GROUP_OBJ.  The chmod(2) already
 * set the mask, so this routine needs to make the same change
 * to the GROUP_OBJ.
 */
static void
handle_acl(char *name, o_mode_t group_clear_bits, o_mode_t group_set_bits)
{
    int aclcnt, n;
    aclent_t *aclp, *tp;
    o_mode_t newperm;
    /*
     * if this file system support ace_t acl's
     * then simply return since we don't have an
     * acl mask to deal with
     */
    if (pathconf(name, _PC_ACL_ENABLED) == _ACL_ACE_ENABLED)
        return;
    if ((aclcnt = acl(name, GETACLCNT, 0, NULL)) <= MIN_ACL_ENTRIES)
        return; /* it's just a trivial acl; no need to change it */
    if ((aclp = (aclent_t *)malloc((sizeof (aclent_t)) * aclcnt))
        == NULL) {
        perror("chmod");
        exit(2);
    }

    if (acl(name, GETACL, aclcnt, aclp) < 0) {
        free(aclp);
        (void) fprintf(stderr, "chmod: ");
        perror(name);
        return;
    }
    for (tp = aclp, n = aclcnt; n--; tp++) {
        if (tp->a_type == GROUP_OBJ) {
            newperm = tp->a_perm;
            if (group_clear_bits != 0)
                newperm &= ~group_clear_bits;
            if (group_set_bits != 0)
                newperm |= group_set_bits;
            if (newperm != tp->a_perm) {
                tp->a_perm = newperm;
                if (acl(name, SETACL, aclcnt, aclp)
                    < 0) {
                    (void) fprintf(stderr, "chmod: ");
                    perror(name);
                }
            }
            break;
        }
    }
    free(aclp);
}

static int
doacl(char *file, struct stat *st, acl_args_t *acl_args)
{
    acl_t *aclp;
    acl_t *set_aclp;
    int error = 0;
    void *to, *from;
    int len;
    int isdir;
    isdir = S_ISDIR(st->st_mode);

    error = acl_get(file, 0, &aclp);

    if (error != 0) {
        errmsg(1, 1, "%s\n", acl_strerror(error));
        return (1);
    }
    switch (acl_args->acl_action) {
    case ACL_ADD:
        if ((error = acl_addentries(aclp,
            acl_args->acl_aclp, acl_args->acl_slot)) != 0) {
            errmsg(1, 1, "%s\n", acl_strerror(error));
            acl_free(aclp);
            return (1);
        }
        set_aclp = aclp;
        break;
    case ACL_SLOT_DELETE:
        if (acl_args->acl_slot + 1 > aclp->acl_cnt) {
            errmsg(1, 1,
                gettext("Invalid slot specified for removal\n"));
            acl_free(aclp);
            return (1);
        }

        if (acl_args->acl_slot == 0 && aclp->acl_cnt == 1) {
            errmsg(1, 1,
                gettext("Can't remove all ACL "
                "entries from a file\n"));
            acl_free(aclp);
            return (1);
        }

        /*
         * remove a single entry
         *
         * if last entry just adjust acl_cnt
         */

        if ((acl_args->acl_slot + 1) == aclp->acl_cnt)
            aclp->acl_cnt--;
        else {
            to = (char *)aclp->acl_aclp +
                (acl_args->acl_slot * aclp->acl_entry_size);
            from = (char *)to + aclp->acl_entry_size;
            len = (aclp->acl_cnt - acl_args->acl_slot - 1) *
                aclp->acl_entry_size;
            (void) memmove(to, from, len);
            aclp->acl_cnt--;
        }
        set_aclp = aclp;
        break;

    case ACL_DELETE:
        if ((error = acl_removeentries(aclp, acl_args->acl_aclp,
            acl_args->acl_slot, ACL_REMOVE_ALL)) != 0) {
            errmsg(1, 1, "%s\n", acl_strerror(error));
            acl_free(aclp);
            return (1);
        }

        if (aclp->acl_cnt == 0) {
            errmsg(1, 1,
                gettext("Can't remove all ACL "
                "entries from a file\n"));
            acl_free(aclp);
            return (1);
        }

        set_aclp = aclp;
        break;
    case ACL_REPLACE:
        if (acl_args->acl_slot >= 0)  {
            error = acl_modifyentries(aclp, acl_args->acl_aclp,
                acl_args->acl_slot);
            if (error) {
                errmsg(1, 1, "%s\n", acl_strerror(error));
                acl_free(aclp);
                return (1);
            }
            set_aclp = aclp;
        } else {
            set_aclp = acl_args->acl_aclp;
        }
        break;
    case ACL_STRIP:
        error = acl_strip(file, st->st_uid, st->st_gid, st->st_mode);
        if (error) {
            errmsg(1, 1, "%s\n", acl_strerror(error));
            return (1);
        }
        acl_free(aclp);
        return (0);
        /*NOTREACHED*/
    default:
        errmsg(1, 0, gettext("Unknown ACL action requested\n"));
        return (1);
        break;
    }
    error = acl_check(set_aclp, isdir);

    if (error) {
        errmsg(1, 0, "%s\n%s", acl_strerror(error),
            gettext("See chmod(1) for more information on "
            "valid ACL syntax\n"));
        return (1);
    }
    if ((error = acl_set(file, set_aclp)) != 0) {
            errmsg(1, 0, gettext("Failed to set ACL: %s\n"),
                acl_strerror(error));
            acl_free(aclp);
            return (1);
    }
    acl_free(aclp);
    return (0);
}

/*
 * Prints out the attributes in their verbose form:
 *  '{'[["no"]<attribute-name>][,["no"]<attribute-name>]...'}'
 * similar to output of ls -/v.
 */
static void
print_nvlist(nvlist_t *attr_nvlist)
{
    int     firsttime = 1;
    boolean_t   value;
    nvlist_t    *lptr = attr_nvlist;
    nvpair_t    *pair = NULL;

    (void) fprintf(stderr, "\t%c", LEFTBRACE);
    while (pair = nvlist_next_nvpair(lptr, pair)) {
        if (nvpair_value_boolean_value(pair, &value) == 0) {
            (void) fprintf(stderr, "%s%s%s",
                firsttime ? "" : A_SEP_TOK,
                (value == A_SET_VAL) ? "" : "no",
                nvpair_name(pair));
            firsttime = 0;
        } else {
            (void) fprintf(stderr, gettext(
                "<error retrieving attributes: %s>"),
                strerror(errno));
            break;
        }
    }
    (void) fprintf(stderr, "%c\n", RIGHTBRACE);
}

/*
 * Add an attribute name and boolean value to an nvlist if an action is to be
 * performed for that attribute.  The nvlist will be used later to set all the
 * attributes in the nvlist in one operation through a call to setattrat().
 *
 * If a set operation ('+') was specified, then a boolean representation of the
 * attribute's value will be added to the nvlist for that attribute name.  If an
 * inverse operation ('-') was specified, then a boolean representation of the
 * inverse of the attribute's value will be added to the nvlist for that
 * attribute name.
 *
 * Returns an nvlist of attribute name and boolean value pairs if there are
 * attribute actions to be performed, otherwise returns NULL.
 */
static nvlist_t *
set_attrs_nvlist(char *attractptr, int numofattrs)
{
    int     attribute_set = 0;
    f_attr_t    i;
    nvlist_t    *attr_nvlist;

    if (nvlist_alloc(&attr_nvlist, NV_UNIQUE_NAME, 0) != 0) {
        perror("chmod");
        exit(2);
    }

    for (i = 0; i < numofattrs; i++) {
        if (attractptr[i] != '\0') {
            if ((nvlist_add_boolean_value(attr_nvlist,
                attr_to_name(i),
                (attractptr[i] == A_SET_OP))) != 0) {
                errmsg(1, 2, gettext(
                    "unable to propagate attribute names and"
                    "values: %s\n"), strerror(errno));
            } else {
                attribute_set = 1;
            }
        }
    }
    return (attribute_set ? attr_nvlist : NULL);
}

/*
 * Set the attributes of file, or if specified, of the named attribute file,
 * attrname.  Build an nvlist of attribute names and values and call setattrat()
 * to set the attributes in one operation.
 *
 * Returns 0 if successful, otherwise returns 1.
 */
static int
set_file_attrs(char *file, char *attrname, nvlist_t *attr_nvlist)
{
    int rc;
    char    *filename;

    if (attrname != NULL) {
        filename = attrname;
    } else {
        filename = basename(file);
    }

    if ((rc = setattrat(AT_FDCWD, XATTR_VIEW_READWRITE, filename,
        attr_nvlist)) != 0) {
        char *emsg;
        switch (errno) {
        case EINVAL:
            emsg = gettext("not supported");
            break;
        case EPERM:
            emsg = gettext("not privileged");
            break;
        default:
            emsg = strerror(rc);
        }
        errmsg(1, 0, gettext(
            "cannot set the following attributes on "
            "%s%s%s%s: %s\n"),
            (attrname == NULL) ? "" : gettext("attribute "),
            (attrname == NULL) ? "" : attrname,
            (attrname == NULL) ? "" : gettext(" of "),
            file, emsg);
        print_nvlist(attr_nvlist);
    }

    return (rc);
}

static int
save_cwd(void)
{
    return (open(".", O_RDONLY));
}

static void
rest_cwd(int cwd)
{
    if (cwd != -1) {
        if (fchdir(cwd) != 0) {
            errmsg(1, 1, gettext(
                "can't change to current working directory\n"));
        }
        (void) close(cwd);
    }
}

/*
 * Returns 1 if filename is a system attribute file, otherwise
 * returns 0.
 */
static int
is_sattr(char *filename)
{
    return (sysattr_type(filename) != _NOT_SATTR);
}

/*
 * Perform the action on the specified named attribute file for the file
 * associated with the input file descriptor.  If the named attribute file
 * is "*", then the action is to be performed on all the named attribute files
 * of the file associated with the input file descriptor.
 */
static int
set_named_attrs(char *file, int parentfd, char *attrname, nvlist_t *attr_nvlist)
{
    int     dirfd;
    int     error = 0;
    DIR     *dirp = NULL;
    struct dirent   *dp;
    struct stat st;

    if ((attrname == NULL) || (strcmp(attrname, "*") != 0)) {
        /*
         * Make sure the named attribute exists and extended system
         * attributes are supported on the underlying file system.
         */
        if (attrname != NULL) {
            if (fstatat(parentfd, attrname, &st,
                AT_SYMLINK_NOFOLLOW) < 0) {
                errmsg(2, 0, gettext(
                    "can't access attribute %s of %s\n"),
                    attrname, file);
                return (1);
            }
            if (sysattr_support(attrname, _PC_SATTR_ENABLED) != 1) {
                errmsg(1, 0, gettext(
                    "extended system attributes not supported "
                    "for attribute %s of %s\n"),
                    attrname, file);
                return (1);
            }
        }

        error = set_file_attrs(file, attrname, attr_nvlist);

    } else {
        if (((dirfd = dup(parentfd)) == -1) ||
            ((dirp = fdopendir(dirfd)) == NULL)) {
            errmsg(1, 0, gettext(
                "cannot open dir pointer of file %s\n"), file);
            if (dirfd > 0) {
                (void) close(dirfd);
            }
            return (1);
        }

        while (dp = readdir(dirp)) {
            /*
             * Process all extended attribute files except
             * ".", "..", and extended system attribute files.
             */
            if ((strcmp(dp->d_name, ".") == 0) ||
                (strcmp(dp->d_name, "..") == 0) ||
                is_sattr(dp->d_name)) {
                continue;
            }

            if (set_named_attrs(file, parentfd, dp->d_name,
                attr_nvlist) != 0) {
                error++;
            }
        }
        if (dirp != NULL) {
            (void) closedir(dirp);
        }
    }

    return ((error == 0) ? 0 : 1);
}

/*
 * Set the attributes of the specified file, or if specified with -@ on the
 * command line, the specified named attributes of the specified file.
 *
 * Returns 0 if successful, otherwise returns 1.
 */
static int
set_attrs(char *file, attr_name_t *attrnames, nvlist_t *attr_nvlist)
{
    char        *parentd;
    char        *tpath = NULL;
    int     cwd;
    int     error = 0;
    int     parentfd;
    attr_name_t *tattr = attrnames;

    if (attr_nvlist == NULL) {
        return (0);
    }

    if (sysattr_support(file, _PC_SATTR_ENABLED) != 1) {
        errmsg(1, 0, gettext(
            "extended system attributes not supported for %s\n"), file);
        return (1);
    }

    /*
     * Open the parent directory and change into it before attempting
     * to set the attributes of the file.
     */
    if (attrnames == NULL) {
        tpath = strdup(file);
        parentd = dirname(tpath);
        parentfd = open(parentd, O_RDONLY);
    } else {
        parentfd = attropen(file, ".", O_RDONLY);
    }
    if (parentfd == -1) {
        errmsg(1, 0, gettext(
            "cannot open attribute directory of %s\n"), file);
        if (tpath != NULL) {
            free(tpath);
        }
        return (1);
    }

    if ((cwd = save_cwd()) < 0) {
        errmsg(1, 1, gettext(
            "can't get current working directory\n"));
    }
    if (fchdir(parentfd) != 0) {
        errmsg(1, 0, gettext(
            "can't change to parent %sdirectory of %s\n"),
            (attrnames == NULL) ? "" : gettext("attribute "), file);
        (void) close(cwd);
        (void) close(parentfd);
        if (tpath != NULL) {
            free(tpath);
        }
        return (1);
    }

    /*
     * If no named attribute file names were provided on the command line
     * then set the attributes of the base file, otherwise, set the
     * attributes for each of the named attribute files specified.
     */
    if (attrnames == NULL) {
        error = set_named_attrs(file, parentfd, NULL, attr_nvlist);
        free(tpath);
    } else {
        while (tattr != NULL) {
            if (set_named_attrs(file, parentfd, tattr->name,
                attr_nvlist) != 0) {
                error++;
            }
            tattr = tattr->next;
        }
    }
    (void) close(parentfd);
    rest_cwd(cwd);

    return ((error == 0) ? 0 : 1);
}

/*
 * Prints the attributes in either the compact or verbose form indicated
 * by flag.
 */
static void
print_attrs(int flag)
{
    f_attr_t    i;
    static int  numofattrs;
    int     firsttime = 1;

    numofattrs = attr_count();

    (void) fprintf(stderr, gettext("\t["));
    for (i = 0; i < numofattrs; i++) {
        if ((attr_to_xattr_view(i) != XATTR_VIEW_READWRITE) ||
            (attr_to_data_type(i) != DATA_TYPE_BOOLEAN_VALUE)) {
            continue;
        }
        (void) fprintf(stderr, "%s%s",
            (firsttime == 1) ? "" : gettext("|"),
            (flag == ATTR_OPTS) ? attr_to_option(i) : attr_to_name(i));
        firsttime = 0;
    }
    (void) fprintf(stderr, gettext("]\n"));
}

/*
 * Record what action should be taken on the specified attribute. Only boolean
 * read-write attributes can be manipulated.
 *
 * Returns 0 if successful, otherwise returns 1.
 */
static int
set_attr_args(f_attr_t attr, char action, char *attractptr)
{
    if ((attr_to_xattr_view(attr) == XATTR_VIEW_READWRITE) &&
        (attr_to_data_type(attr) == DATA_TYPE_BOOLEAN_VALUE)) {
        attractptr[attr] = action;
        return (0);
    }
    return (1);
}

/*
 * Parses the entry and assigns the appropriate action (either '+' or '-' in
 * attribute's position in the character array pointed to by attractptr, where
 * upon exit, attractptr is positional and the value of each character specifies
 * whether to set (a '+'), clear (a '-'), or leave untouched (a '\0') the
 * attribute value.
 *
 * If the entry is an attribute name, then the A_SET_OP action is to be
 * performed for this attribute.  If the entry is an attribute name proceeded
 * with "no", then the A_INVERSE_OP action is to be performed for this
 * attribute.  If the entry is one or more attribute option letters, then step
 * through each of the option letters marking the action to be performed for
 * each of the attributes associated with the letter as A_SET_OP.
 *
 * Returns 0 if the entry was a valid attribute(s) and the action to be
 * performed on that attribute(s) has been recorded, otherwise returns 1.
 */
static int
parse_entry(char *entry, char action, char atype, int len, char *attractptr)
{
    char        aopt[2] = {'\0', '\0'};
    char        *aptr;
    f_attr_t    attr;

    if (atype == A_VERBOSE_TYPE) {
        if ((attr = name_to_attr(entry)) != F_ATTR_INVAL) {
            return (set_attr_args(attr,
                (action == A_REPLACE_OP) ? A_SET_OP : action,
                attractptr));
        } else if ((len > 2) && (strncmp(entry, "no", 2) == 0) &&
            ((attr = name_to_attr(entry + 2)) != F_ATTR_INVAL)) {
            return (set_attr_args(attr, ((action == A_REPLACE_OP) ||
                (action == A_SET_OP)) ? A_INVERSE_OP : A_SET_OP,
                attractptr));
        } else {
            return (1);
        }
    } else if (atype == A_COMPACT_TYPE) {
        for (aptr = entry; *aptr != '\0'; aptr++) {
            *aopt = *aptr;
            /*
             * The output of 'ls' can be used as the attribute mode
             * specification for chmod.  This output can contain a
             * hypen ('-') for each attribute that is not set.  If
             * so, ignore them.  If a replace action is being
             * performed, then all attributes that don't have an
             * action set here, will be cleared down the line.
             */
            if (*aptr == '-') {
                continue;
            }
            if (set_attr_args(option_to_attr(aopt),
                (action == A_REPLACE_OP) ? A_SET_OP : action,
                attractptr) != 0) {
                return (1);
            }
        }
        return (0);
    }
    return (1);
}

/*
 * Parse the attribute specification, aoptsstr.  Upon completion, attr_nvlist
 * will point to an nvlist which contains pairs of attribute names and values
 * to be set; attr_nvlist will be NULL if it is a no-op.
 *
 * The attribute specification format is
 *  S[oper]attr_type[attribute_list]
 * where oper is
 *  +   set operation of specified attributes in attribute list.
 *      This is the default operation.
 *  -   inverse operation of specified attributes in attribute list
 *  =   replace operation of all attributes.  All attribute operations
 *      depend on those specified in the attribute list.  Attributes
 *      not specified in the attribute list will be cleared.
 * where attr_type is
 *  c   compact type.  Each entry in the attribute list is a character
 *      option representing an associated attribute name.
 *  v   verbose type.  Each entry in the attribute list is an
 *      an attribute name which can optionally be preceeded with "no"
 *      (to imply the attribute should be cleared).
 *  a   all attributes type.  The oper should be applied to all
 *      read-write boolean system attributes.  No attribute list should
 *      be specified after an 'a' attribute type.
 *
 * Returns 0 if aoptsstr contained a valid attribute specification,
 * otherwise, returns 1.
 */
static int
parse_attr_args(char *aoptsstr, sec_args_t **sec_args)
{
    char        action;
    char        *attractptr;
    char        atype;
    char        *entry;
    char        *eptr;
    char        *nextattr;
    char        *nextentry;
    char        *subentry;
    char        *teptr;
    char        tok[] = {'\0', '\0'};
    int     len;
    f_attr_t    i;
    int     numofattrs;

    if ((*aoptsstr != 'S') || (*(aoptsstr + 1) == '\0')) {
        return (1);
    }

    if ((eptr = strdup(aoptsstr + 1)) == NULL) {
        perror("chmod");
        exit(2);
    }
    entry = eptr;

    /*
     * Create a positional character array to determine a single attribute
     * operation to be performed, where each index represents the system
     * attribute affected, and it's value in the array represents the action
     * to be performed, i.e., a value of '+' means to set the attribute, a
     * value of '-' means to clear the attribute, and a value of '\0' means
     * to leave the attribute untouched.  Initially, this positional
     * character array is all '\0's, representing a no-op.
     */
    if ((numofattrs = attr_count()) < 1) {
        errmsg(1, 1, gettext("system attributes not supported\n"));
    }

    if ((attractptr = calloc(numofattrs, sizeof (char))) == NULL) {
        perror("chmod");
        exit(2);
    }

    if ((*sec_args = malloc(sizeof (sec_args_t))) == NULL) {
        perror("chmod");
        exit(2);
    }
    (*sec_args)->sec_type = SEC_ATTR;
    (*sec_args)->sec_attrs = NULL;

    /* Parse each attribute operation within the attribute specification. */
    while ((entry != NULL) && (*entry != '\0')) {
        action = A_SET_OP;
        atype = '\0';

        /* Get the operator. */
        switch (*entry) {
        case A_SET_OP:
        case A_INVERSE_OP:
        case A_REPLACE_OP:
            action = *entry++;
            break;
        case A_COMPACT_TYPE:
        case A_VERBOSE_TYPE:
        case A_ALLATTRS_TYPE:
            atype = *entry++;
            action = A_SET_OP;
            break;
        default:
            break;
        }

        /* An attribute type must be specified. */
        if (atype == '\0') {
            if ((*entry == A_COMPACT_TYPE) ||
                (*entry == A_VERBOSE_TYPE) ||
                (*entry == A_ALLATTRS_TYPE)) {
                atype = *entry++;
            } else {
                return (1);
            }
        }

        /* Get the attribute specification separator. */
        if (*entry == LEFTBRACE) {
            *tok = RIGHTBRACE;
            entry++;
        } else {
            *tok = A_SEP;
        }

        /* Get the attribute operation */
        if ((nextentry = strpbrk(entry, tok)) != NULL) {
            *nextentry = '\0';
            nextentry++;
        }

        /* Check for a no-op */
        if ((*entry == '\0') && (atype != A_ALLATTRS_TYPE) &&
            (action != A_REPLACE_OP)) {
            entry = nextentry;
            continue;
        }

        /*
         * Step through the attribute operation, setting the
         * appropriate values for the specified attributes in the
         * character array, attractptr. A value of '+' will mean the
         * attribute is to be set, and a value of '-' will mean the
         * attribute is to be cleared.  If the value of an attribute
         * remains '\0', then no action is to be taken on that
         * attribute.  As multiple operations specified are
         * accumulated, a single attribute setting operation is
         * represented in attractptr.
         */
        len = strlen(entry);
        if ((*tok == RIGHTBRACE) || (action == A_REPLACE_OP) ||
            (atype == A_ALLATTRS_TYPE)) {

            if ((action == A_REPLACE_OP) ||
                (atype == A_ALLATTRS_TYPE)) {
                (void) memset(attractptr, '\0', numofattrs);
            }

            if (len > 0) {
                if ((teptr = strdup(entry)) == NULL) {
                    perror("chmod");
                    exit(2);
                }
                subentry = teptr;
                while (subentry != NULL) {
                    if ((nextattr = strpbrk(subentry,
                        A_SEP_TOK)) != NULL) {
                        *nextattr = '\0';
                        nextattr++;
                    }
                    if (parse_entry(subentry, action,
                        atype, len, attractptr) != 0) {
                        return (1);
                    }
                    subentry = nextattr;
                }
                free(teptr);
            }

            /*
             * If performing the replace action, record the
             * attributes and values for the rest of the
             * attributes that have not already been recorded,
             * otherwise record the specified action for all
             * attributes.  Note: set_attr_args() will only record
             * the attribute and action if it is a boolean
             * read-write attribute so we don't need to worry
             * about checking it here.
             */
            if ((action == A_REPLACE_OP) ||
                (atype == A_ALLATTRS_TYPE)) {
                for (i = 0; i < numofattrs; i++) {
                    if (attractptr[i] == A_UNDEF_OP) {
                        (void) set_attr_args(i,
                            (action == A_SET_OP) ?
                            A_SET_OP : A_INVERSE_OP,
                            attractptr);
                    }
                }
            }

        } else {
            if (parse_entry(entry, action, atype, len,
                attractptr) != 0) {
                return (1);
            }
        }
        entry = nextentry;
    }

    /*
     * Populate an nvlist with attribute name and boolean value pairs
     * using the single attribute operation.
     */
    (*sec_args)->sec_attrs = set_attrs_nvlist(attractptr, numofattrs);
    free(attractptr);
    free(eptr);

    return (0);
}