/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2002-2005 Networks Associates Technology, Inc.
 * All rights reserved.
 *
 * This software was developed for the FreeBSD Project by Network Associates
 * Laboratories, the Security Research Division of Network Associates, Inc.
 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
 * DARPA CHATS research program.
 *
 * 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.
 */
#include <sys/param.h>
#include <sys/errno.h>
#include <sys/jail.h>
#include <sys/time.h>
#include <sys/sysctl.h>
#include <sys/ucred.h>
#include <sys/uio.h>
#include <sys/mount.h>

#include <security/mac_bsdextended/mac_bsdextended.h>

#include <grp.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "ugidfw.h"

/*
 * Text format for rules: rules contain subject and object elements, mode.
 * The total form is "subject [s_element] object [o_element] mode [mode]".
 * At least * one of a uid or gid entry must be present; both may also be
 * present.
 */

#define MIB     "security.mac.bsdextended"

int
bsde_rule_to_string(struct mac_bsdextended_rule *rule, char *buf, size_t buflen)
{
        struct group *grp;
        struct passwd *pwd;
        struct statfs *mntbuf;
        char *cur, type[sizeof(rule->mbr_object.mbo_type) * CHAR_BIT + 1];
        size_t left, len;
        int anymode, unknownmode, numfs, i, notdone;

        cur = buf;
        left = buflen;

        len = snprintf(cur, left, "subject ");
        if (len < 0 || len > left)
                goto truncated;
        left -= len;
        cur += len;
        if (rule->mbr_subject.mbs_flags) {
                if (rule->mbr_subject.mbs_neg == MBS_ALL_FLAGS) {
                        len = snprintf(cur, left, "not ");
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                        notdone = 1;
                } else {
                        notdone = 0;
                }

                if (!notdone && (rule->mbr_subject.mbs_neg & MBO_UID_DEFINED)) {
                        len = snprintf(cur, left, "! ");
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
                if (rule->mbr_subject.mbs_flags & MBO_UID_DEFINED) {
                        pwd = getpwuid(rule->mbr_subject.mbs_uid_min);
                        if (pwd != NULL) {
                                len = snprintf(cur, left, "uid %s",
                                    pwd->pw_name);
                                if (len < 0 || len > left)
                                        goto truncated;
                                left -= len;
                                cur += len;
                        } else {
                                len = snprintf(cur, left, "uid %u",
                                    rule->mbr_subject.mbs_uid_min);
                                if (len < 0 || len > left)
                                        goto truncated;
                                left -= len;
                                cur += len;
                        }
                        if (rule->mbr_subject.mbs_uid_min !=
                            rule->mbr_subject.mbs_uid_max) {
                                pwd = getpwuid(rule->mbr_subject.mbs_uid_max);
                                if (pwd != NULL) {
                                        len = snprintf(cur, left, ":%s ",
                                            pwd->pw_name);
                                        if (len < 0 || len > left)
                                                goto truncated;
                                        left -= len;
                                        cur += len;
                                } else {
                                        len = snprintf(cur, left, ":%u ",
                                            rule->mbr_subject.mbs_uid_max);
                                        if (len < 0 || len > left)
                                                goto truncated;
                                        left -= len;
                                        cur += len;
                                }
                        } else {
                                len = snprintf(cur, left, " ");
                                if (len < 0 || len > left)
                                        goto truncated;
                                left -= len;
                                cur += len;
                        }
                }
                if (!notdone && (rule->mbr_subject.mbs_neg & MBO_GID_DEFINED)) {
                        len = snprintf(cur, left, "! ");
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
                if (rule->mbr_subject.mbs_flags & MBO_GID_DEFINED) {
                        grp = getgrgid(rule->mbr_subject.mbs_gid_min);
                        if (grp != NULL) {
                                len = snprintf(cur, left, "gid %s",
                                    grp->gr_name);
                                if (len < 0 || len > left)
                                        goto truncated;
                                left -= len;
                                cur += len;
                        } else {
                                len = snprintf(cur, left, "gid %u",
                                    rule->mbr_subject.mbs_gid_min);
                                if (len < 0 || len > left)
                                        goto truncated;
                                left -= len;
                                cur += len;
                        }
                        if (rule->mbr_subject.mbs_gid_min !=
                            rule->mbr_subject.mbs_gid_max) {
                                grp = getgrgid(rule->mbr_subject.mbs_gid_max);
                                if (grp != NULL) {
                                        len = snprintf(cur, left, ":%s ",
                                            grp->gr_name);
                                        if (len < 0 || len > left)
                                                goto truncated;
                                        left -= len;
                                        cur += len;
                                } else {
                                        len = snprintf(cur, left, ":%u ",
                                            rule->mbr_subject.mbs_gid_max);
                                        if (len < 0 || len > left)
                                                goto truncated;
                                        left -= len;
                                        cur += len;
                                }
                        } else {
                                len = snprintf(cur, left, " ");
                                if (len < 0 || len > left)
                                        goto truncated;
                                left -= len;
                                cur += len;
                        }
                }
                if (!notdone && (rule->mbr_subject.mbs_neg & MBS_PRISON_DEFINED)) {
                        len = snprintf(cur, left, "! ");
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
                if (rule->mbr_subject.mbs_flags & MBS_PRISON_DEFINED) {
                        len = snprintf(cur, left, "jailid %d ",
                            rule->mbr_subject.mbs_prison);
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
        }

        len = snprintf(cur, left, "object ");
        if (len < 0 || len > left)
                goto truncated;
        left -= len;
        cur += len;
        if (rule->mbr_object.mbo_flags) {
                if (rule->mbr_object.mbo_neg == MBO_ALL_FLAGS) {
                        len = snprintf(cur, left, "not ");
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                        notdone = 1;
                } else {
                        notdone = 0;
                }

                if (!notdone && (rule->mbr_object.mbo_neg & MBO_UID_DEFINED)) {
                        len = snprintf(cur, left, "! ");
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
                if (rule->mbr_object.mbo_flags & MBO_UID_DEFINED) {
                        pwd = getpwuid(rule->mbr_object.mbo_uid_min);
                        if (pwd != NULL) {
                                len = snprintf(cur, left, "uid %s",
                                    pwd->pw_name);
                                if (len < 0 || len > left)
                                        goto truncated;
                                left -= len;
                                cur += len;
                        } else {
                                len = snprintf(cur, left, "uid %u",
                                    rule->mbr_object.mbo_uid_min);
                                if (len < 0 || len > left)
                                        goto truncated;
                                left -= len;
                                cur += len;
                        }
                        if (rule->mbr_object.mbo_uid_min !=
                            rule->mbr_object.mbo_uid_max) {
                                pwd = getpwuid(rule->mbr_object.mbo_uid_max);
                                if (pwd != NULL) {
                                        len = snprintf(cur, left, ":%s ",
                                            pwd->pw_name);
                                        if (len < 0 || len > left)
                                                goto truncated;
                                        left -= len;
                                        cur += len;
                                } else {
                                        len = snprintf(cur, left, ":%u ",
                                            rule->mbr_object.mbo_uid_max);
                                        if (len < 0 || len > left)
                                                goto truncated;
                                        left -= len;
                                        cur += len;
                                }
                        } else {
                                len = snprintf(cur, left, " ");
                                if (len < 0 || len > left)
                                        goto truncated;
                                left -= len;
                                cur += len;
                        }
                }
                if (!notdone && (rule->mbr_object.mbo_neg & MBO_GID_DEFINED)) {
                        len = snprintf(cur, left, "! ");
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
                if (rule->mbr_object.mbo_flags & MBO_GID_DEFINED) {
                        grp = getgrgid(rule->mbr_object.mbo_gid_min);
                        if (grp != NULL) {
                                len = snprintf(cur, left, "gid %s",
                                    grp->gr_name);
                                if (len < 0 || len > left)
                                        goto truncated;
                                left -= len;
                                cur += len;
                        } else {
                                len = snprintf(cur, left, "gid %u",
                                    rule->mbr_object.mbo_gid_min);
                                if (len < 0 || len > left)
                                        goto truncated;
                                left -= len;
                                cur += len;
                        }
                        if (rule->mbr_object.mbo_gid_min !=
                            rule->mbr_object.mbo_gid_max) {
                                grp = getgrgid(rule->mbr_object.mbo_gid_max);
                                if (grp != NULL) {
                                        len = snprintf(cur, left, ":%s ",
                                            grp->gr_name);
                                        if (len < 0 || len > left)
                                                goto truncated;
                                        left -= len;
                                        cur += len;
                                } else {
                                        len = snprintf(cur, left, ":%u ",
                                            rule->mbr_object.mbo_gid_max);
                                        if (len < 0 || len > left)
                                                goto truncated;
                                        left -= len;
                                        cur += len;
                                }
                        } else {
                                len = snprintf(cur, left, " ");
                                if (len < 0 || len > left)
                                        goto truncated;
                                left -= len;
                                cur += len;
                        }
                }
                if (!notdone && (rule->mbr_object.mbo_neg & MBO_FSID_DEFINED)) {
                        len = snprintf(cur, left, "! ");
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
                if (rule->mbr_object.mbo_flags & MBO_FSID_DEFINED) {
                        numfs = getmntinfo(&mntbuf, MNT_NOWAIT);
                        for (i = 0; i < numfs; i++)
                                if (fsidcmp(&rule->mbr_object.mbo_fsid,
                                    &mntbuf[i].f_fsid) == 0)
                                        break;
                        len = snprintf(cur, left, "filesys %s ",
                            i == numfs ? "???" : mntbuf[i].f_mntonname);
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
                if (!notdone && (rule->mbr_object.mbo_neg & MBO_SUID)) {
                        len = snprintf(cur, left, "! ");
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
                if (rule->mbr_object.mbo_flags & MBO_SUID) {
                        len = snprintf(cur, left, "suid ");
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
                if (!notdone && (rule->mbr_object.mbo_neg & MBO_SGID)) {
                        len = snprintf(cur, left, "! ");
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
                if (rule->mbr_object.mbo_flags & MBO_SGID) {
                        len = snprintf(cur, left, "sgid ");
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
                if (!notdone && (rule->mbr_object.mbo_neg & MBO_UID_SUBJECT)) {
                        len = snprintf(cur, left, "! ");
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
                if (rule->mbr_object.mbo_flags & MBO_UID_SUBJECT) {
                        len = snprintf(cur, left, "uid_of_subject ");
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
                if (!notdone && (rule->mbr_object.mbo_neg & MBO_GID_SUBJECT)) {
                        len = snprintf(cur, left, "! ");
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
                if (rule->mbr_object.mbo_flags & MBO_GID_SUBJECT) {
                        len = snprintf(cur, left, "gid_of_subject ");
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
                if (!notdone && (rule->mbr_object.mbo_neg & MBO_TYPE_DEFINED)) {
                        len = snprintf(cur, left, "! ");
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
                if (rule->mbr_object.mbo_flags & MBO_TYPE_DEFINED) {
                        i = 0;
                        if (rule->mbr_object.mbo_type & MBO_TYPE_REG)
                                type[i++] = 'r';
                        if (rule->mbr_object.mbo_type & MBO_TYPE_DIR)
                                type[i++] = 'd';
                        if (rule->mbr_object.mbo_type & MBO_TYPE_BLK)
                                type[i++] = 'b';
                        if (rule->mbr_object.mbo_type & MBO_TYPE_CHR)
                                type[i++] = 'c';
                        if (rule->mbr_object.mbo_type & MBO_TYPE_LNK)
                                type[i++] = 'l';
                        if (rule->mbr_object.mbo_type & MBO_TYPE_SOCK)
                                type[i++] = 's';
                        if (rule->mbr_object.mbo_type & MBO_TYPE_FIFO)
                                type[i++] = 'p';
                        if (rule->mbr_object.mbo_type == MBO_ALL_TYPE) {
                                i = 0;
                                type[i++] = 'a';
                        }
                        type[i++] = '\0';
                        len = snprintf(cur, left, "type %s ", type);
                        if (len < 0 || len > left)
                                goto truncated;
                        left -= len;
                        cur += len;
                }
        }

        len = snprintf(cur, left, "mode ");
        if (len < 0 || len > left)
                goto truncated;
        left -= len;
        cur += len;

        anymode = (rule->mbr_mode & MBI_ALLPERM);
        unknownmode = (rule->mbr_mode & ~MBI_ALLPERM);

        if (rule->mbr_mode & MBI_ADMIN) {
                len = snprintf(cur, left, "a");
                if (len < 0 || len > left)
                        goto truncated;

                left -= len;
                cur += len;
        }
        if (rule->mbr_mode & MBI_READ) {
                len = snprintf(cur, left, "r");
                if (len < 0 || len > left)
                        goto truncated;

                left -= len;
                cur += len;
        }
        if (rule->mbr_mode & MBI_STAT) {
                len = snprintf(cur, left, "s");
                if (len < 0 || len > left)
                        goto truncated;

                left -= len;
                cur += len;
        }
        if (rule->mbr_mode & MBI_WRITE) {
                len = snprintf(cur, left, "w");
                if (len < 0 || len > left)
                        goto truncated;

                left -= len;
                cur += len;
        }
        if (rule->mbr_mode & MBI_EXEC) {
                len = snprintf(cur, left, "x");
                if (len < 0 || len > left)
                        goto truncated;

                left -= len;
                cur += len;
        }
        if (!anymode) {
                len = snprintf(cur, left, "n");
                if (len < 0 || len > left)
                        goto truncated;

                left -= len;
                cur += len;
        }
        if (unknownmode) {
                len = snprintf(cur, left, "?");
                if (len < 0 || len > left)
                        goto truncated;

                left -= len;
                cur += len;
        }

        return (0);

truncated:
        return (-1);
}

static int
bsde_parse_uidrange(char *spec, uid_t *min, uid_t *max,
    size_t buflen, char *errstr){
        struct passwd *pwd;
        uid_t uid1, uid2;
        char *spec1, *spec2, *endp;
        unsigned long value;

        spec2 = spec;
        spec1 = strsep(&spec2, ":");

        pwd = getpwnam(spec1);
        if (pwd != NULL)
                uid1 = pwd->pw_uid;
        else {
                value = strtoul(spec1, &endp, 10);
                if (*endp != '\0') {
                        snprintf(errstr, buflen, "invalid uid: '%s'", spec1);
                        return (-1);
                }
                uid1 = value;
        }

        if (spec2 == NULL) {
                *max = *min = uid1;
                return (0);
        }

        pwd = getpwnam(spec2);
        if (pwd != NULL)
                uid2 = pwd->pw_uid;
        else {
                value = strtoul(spec2, &endp, 10);
                if (*endp != '\0') {
                        snprintf(errstr, buflen, "invalid uid: '%s'", spec2);
                        return (-1);
                }
                uid2 = value;
        }

        *min = uid1;
        *max = uid2;

        return (0);
}

static int
bsde_parse_gidrange(char *spec, gid_t *min, gid_t *max,
    size_t buflen, char *errstr){
        struct group *grp;
        gid_t gid1, gid2;
        char *spec1, *spec2, *endp;
        unsigned long value;

        spec2 = spec;
        spec1 = strsep(&spec2, ":");

        grp = getgrnam(spec1);
        if (grp != NULL)
                gid1 = grp->gr_gid;
        else {
                value = strtoul(spec1, &endp, 10);
                if (*endp != '\0') {
                        snprintf(errstr, buflen, "invalid gid: '%s'", spec1);
                        return (-1);
                }
                gid1 = value;
        }

        if (spec2 == NULL) {
                *max = *min = gid1;
                return (0);
        }

        grp = getgrnam(spec2);
        if (grp != NULL)
                gid2 = grp->gr_gid;
        else {
                value = strtoul(spec2, &endp, 10);
                if (*endp != '\0') {
                        snprintf(errstr, buflen, "invalid gid: '%s'", spec2);
                        return (-1);
                }
                gid2 = value;
        }

        *min = gid1;
        *max = gid2;

        return (0);
}

static int
bsde_get_jailid(const char *name, size_t buflen, char *errstr)
{
        char *ep;
        int jid;
        struct iovec jiov[4];

        /* Copy jail_getid(3) instead of messing with library dependancies */
        jid = strtoul(name, &ep, 10);
        if (*name && !*ep)
                return jid;
        jiov[0].iov_base = __DECONST(char *, "name");
        jiov[0].iov_len = sizeof("name");
        jiov[1].iov_len = strlen(name) + 1;
        jiov[1].iov_base = alloca(jiov[1].iov_len);
        strcpy(jiov[1].iov_base, name);
        if (errstr && buflen) {
                jiov[2].iov_base = __DECONST(char *, "errmsg");
                jiov[2].iov_len = sizeof("errmsg");
                jiov[3].iov_base = errstr;
                jiov[3].iov_len = buflen;
                errstr[0] = 0;
                jid = jail_get(jiov, 4, 0);
                if (jid < 0 && !errstr[0])
                        snprintf(errstr, buflen, "jail_get: %s",
                            strerror(errno));
        } else
                jid = jail_get(jiov, 2, 0);
        return jid;
}

static int
bsde_parse_subject(int argc, char *argv[],
    struct mac_bsdextended_subject *subject, size_t buflen, char *errstr)
{
        int not_seen, flags;
        int current, neg, nextnot;
        uid_t uid_min, uid_max;
        gid_t gid_min, gid_max;
        int jid = 0;

        current = 0;
        flags = 0;
        neg = 0;
        nextnot = 0;

        if (strcmp("not", argv[current]) == 0) {
                not_seen = 1;
                current++;
        } else
                not_seen = 0;

        while (current < argc) {
                if (strcmp(argv[current], "uid") == 0) {
                        if (current + 2 > argc) {
                                snprintf(errstr, buflen, "uid short");
                                return (-1);
                        }
                        if (flags & MBS_UID_DEFINED) {
                                snprintf(errstr, buflen, "one uid only");
                                return (-1);
                        }
                        if (bsde_parse_uidrange(argv[current+1],
                            &uid_min, &uid_max, buflen, errstr) < 0)
                                return (-1);
                        flags |= MBS_UID_DEFINED;
                        if (nextnot) {
                                neg ^= MBS_UID_DEFINED;
                                nextnot = 0;
                        }
                        current += 2;
                } else if (strcmp(argv[current], "gid") == 0) {
                        if (current + 2 > argc) {
                                snprintf(errstr, buflen, "gid short");
                                return (-1);
                        }
                        if (flags & MBS_GID_DEFINED) {
                                snprintf(errstr, buflen, "one gid only");
                                return (-1);
                        }
                        if (bsde_parse_gidrange(argv[current+1],
                            &gid_min, &gid_max, buflen, errstr) < 0)
                                return (-1);
                        flags |= MBS_GID_DEFINED;
                        if (nextnot) {
                                neg ^= MBS_GID_DEFINED;
                                nextnot = 0;
                        }
                        current += 2;
                } else if (strcmp(argv[current], "jailid") == 0) {
                        if (current + 2 > argc) {
                                snprintf(errstr, buflen, "prison short");
                                return (-1);
                        }
                        if (flags & MBS_PRISON_DEFINED) {
                                snprintf(errstr, buflen, "one jail only");
                                return (-1);
                        }
                        jid = bsde_get_jailid(argv[current+1], buflen, errstr);
                        if (jid < 0)
                                return (-1);
                        flags |= MBS_PRISON_DEFINED;
                        if (nextnot) {
                                neg ^= MBS_PRISON_DEFINED;
                                nextnot = 0;
                        }
                        current += 2;
                } else if (strcmp(argv[current], "!") == 0) {
                        if (nextnot) {
                                snprintf(errstr, buflen, "double negative");
                                return (-1);
                        }
                        nextnot = 1;
                        current += 1;
                } else {
                        snprintf(errstr, buflen, "'%s' not expected",
                            argv[current]);
                        return (-1);
                }
        }

        subject->mbs_flags = flags;
        if (not_seen)
                subject->mbs_neg = MBS_ALL_FLAGS ^ neg;
        else
                subject->mbs_neg = neg;
        if (flags & MBS_UID_DEFINED) {
                subject->mbs_uid_min = uid_min;
                subject->mbs_uid_max = uid_max;
        }
        if (flags & MBS_GID_DEFINED) {
                subject->mbs_gid_min = gid_min;
                subject->mbs_gid_max = gid_max;
        }
        if (flags & MBS_PRISON_DEFINED)
                subject->mbs_prison = jid;

        return (0);
}

static int
bsde_parse_type(char *spec, int *type, size_t buflen, char *errstr)
{
        int i;

        *type = 0;
        for (i = 0; i < strlen(spec); i++) {
                switch (spec[i]) {
                case 'r':
                case '-':
                        *type |= MBO_TYPE_REG;
                        break;
                case 'd':
                        *type |= MBO_TYPE_DIR;
                        break;
                case 'b':
                        *type |= MBO_TYPE_BLK;
                        break;
                case 'c':
                        *type |= MBO_TYPE_CHR;
                        break;
                case 'l':
                        *type |= MBO_TYPE_LNK;
                        break;
                case 's':
                        *type |= MBO_TYPE_SOCK;
                        break;
                case 'p':
                        *type |= MBO_TYPE_FIFO;
                        break;
                case 'a':
                        *type |= MBO_ALL_TYPE;
                        break;
                default:
                        snprintf(errstr, buflen, "Unknown type code: %c",
                            spec[i]);
                        return (-1);
                }
        }

        return (0);
}

static int
bsde_parse_fsid(char *spec, struct fsid *fsid, size_t buflen, char *errstr)
{
        struct statfs buf;

        if (statfs(spec, &buf) < 0) {
                snprintf(errstr, buflen, "Unable to get id for %s: %s",
                    spec, strerror(errno));
                return (-1);
        }

        *fsid = buf.f_fsid;

        return (0);
}

static int
bsde_parse_object(int argc, char *argv[],
    struct mac_bsdextended_object *object, size_t buflen, char *errstr)
{
        int not_seen, flags;
        int current, neg, nextnot;
        int type;
        uid_t uid_min, uid_max;
        gid_t gid_min, gid_max;
        struct fsid fsid;

        current = 0;
        flags = 0;
        neg = 0;
        nextnot = 0;
        type = 0;

        if (strcmp("not", argv[current]) == 0) {
                not_seen = 1;
                current++;
        } else
                not_seen = 0;

        while (current < argc) {
                if (strcmp(argv[current], "uid") == 0) {
                        if (current + 2 > argc) {
                                snprintf(errstr, buflen, "uid short");
                                return (-1);
                        }
                        if (flags & MBO_UID_DEFINED) {
                                snprintf(errstr, buflen, "one uid only");
                                return (-1);
                        }
                        if (bsde_parse_uidrange(argv[current+1],
                            &uid_min, &uid_max, buflen, errstr) < 0)
                                return (-1);
                        flags |= MBO_UID_DEFINED;
                        if (nextnot) {
                                neg ^= MBO_UID_DEFINED;
                                nextnot = 0;
                        }
                        current += 2;
                } else if (strcmp(argv[current], "gid") == 0) {
                        if (current + 2 > argc) {
                                snprintf(errstr, buflen, "gid short");
                                return (-1);
                        }
                        if (flags & MBO_GID_DEFINED) {
                                snprintf(errstr, buflen, "one gid only");
                                return (-1);
                        }
                        if (bsde_parse_gidrange(argv[current+1],
                            &gid_min, &gid_max, buflen, errstr) < 0)
                                return (-1);
                        flags |= MBO_GID_DEFINED;
                        if (nextnot) {
                                neg ^= MBO_GID_DEFINED;
                                nextnot = 0;
                        }
                        current += 2;
                } else if (strcmp(argv[current], "filesys") == 0) {
                        if (current + 2 > argc) {
                                snprintf(errstr, buflen, "filesys short");
                                return (-1);
                        }
                        if (flags & MBO_FSID_DEFINED) {
                                snprintf(errstr, buflen, "one fsid only");
                                return (-1);
                        }
                        if (bsde_parse_fsid(argv[current+1], &fsid,
                            buflen, errstr) < 0)
                                return (-1);
                        flags |= MBO_FSID_DEFINED;
                        if (nextnot) {
                                neg ^= MBO_FSID_DEFINED;
                                nextnot = 0;
                        }
                        current += 2;
                } else if (strcmp(argv[current], "suid") == 0) {
                        flags |= MBO_SUID;
                        if (nextnot) {
                                neg ^= MBO_SUID;
                                nextnot = 0;
                        }
                        current += 1;
                } else if (strcmp(argv[current], "sgid") == 0) {
                        flags |= MBO_SGID;
                        if (nextnot) {
                                neg ^= MBO_SGID;
                                nextnot = 0;
                        }
                        current += 1;
                } else if (strcmp(argv[current], "uid_of_subject") == 0) {
                        flags |= MBO_UID_SUBJECT;
                        if (nextnot) {
                                neg ^= MBO_UID_SUBJECT;
                                nextnot = 0;
                        }
                        current += 1;
                } else if (strcmp(argv[current], "gid_of_subject") == 0) {
                        flags |= MBO_GID_SUBJECT;
                        if (nextnot) {
                                neg ^= MBO_GID_SUBJECT;
                                nextnot = 0;
                        }
                        current += 1;
                } else if (strcmp(argv[current], "type") == 0) {
                        if (current + 2 > argc) {
                                snprintf(errstr, buflen, "type short");
                                return (-1);
                        }
                        if (flags & MBO_TYPE_DEFINED) {
                                snprintf(errstr, buflen, "one type only");
                                return (-1);
                        }
                        if (bsde_parse_type(argv[current+1], &type,
                            buflen, errstr) < 0)
                                return (-1);
                        flags |= MBO_TYPE_DEFINED;
                        if (nextnot) {
                                neg ^= MBO_TYPE_DEFINED;
                                nextnot = 0;
                        }
                        current += 2;
                } else if (strcmp(argv[current], "!") == 0) {
                        if (nextnot) {
                                snprintf(errstr, buflen,
                                    "double negative'");
                                return (-1);
                        }
                        nextnot = 1;
                        current += 1;
                } else {
                        snprintf(errstr, buflen, "'%s' not expected",
                            argv[current]);
                        return (-1);
                }
        }

        object->mbo_flags = flags;
        if (not_seen)
                object->mbo_neg = MBO_ALL_FLAGS ^ neg;
        else
                object->mbo_neg = neg;
        if (flags & MBO_UID_DEFINED) {
                object->mbo_uid_min = uid_min;
                object->mbo_uid_max = uid_max;
        }
        if (flags & MBO_GID_DEFINED) {
                object->mbo_gid_min = gid_min;
                object->mbo_gid_max = gid_max;
        }
        if (flags & MBO_FSID_DEFINED)
                object->mbo_fsid = fsid;
        if (flags & MBO_TYPE_DEFINED)
                object->mbo_type = type;

        return (0);
}

int
bsde_parse_mode(int argc, char *argv[], mode_t *mode, size_t buflen,
    char *errstr)
{
        int i;

        if (argc == 0) {
                snprintf(errstr, buflen, "mode expects mode value");
                return (-1);
        }

        if (argc != 1) {
                snprintf(errstr, buflen, "'%s' unexpected", argv[1]);
                return (-1);
        }

        *mode = 0;
        for (i = 0; i < strlen(argv[0]); i++) {
                switch (argv[0][i]) {
                case 'a':
                        *mode |= MBI_ADMIN;
                        break;
                case 'r':
                        *mode |= MBI_READ;
                        break;
                case 's':
                        *mode |= MBI_STAT;
                        break;
                case 'w':
                        *mode |= MBI_WRITE;
                        break;
                case 'x':
                        *mode |= MBI_EXEC;
                        break;
                case 'n':
                        /* ignore */
                        break;
                default:
                        snprintf(errstr, buflen, "Unknown mode letter: %c",
                            argv[0][i]);
                        return (-1);
                }
        }

        return (0);
}

int
bsde_parse_rule(int argc, char *argv[], struct mac_bsdextended_rule *rule,
    size_t buflen, char *errstr)
{
        int subject, subject_elements, subject_elements_length;
        int object, object_elements, object_elements_length;
        int mode, mode_elements, mode_elements_length;
        int error, i;

        bzero(rule, sizeof(*rule));

        if (argc < 1) {
                snprintf(errstr, buflen, "Rule must begin with subject");
                return (-1);
        }

        if (strcmp(argv[0], "subject") != 0) {
                snprintf(errstr, buflen, "Rule must begin with subject");
                return (-1);
        }
        subject = 0;
        subject_elements = 1;

        /* Search forward for object. */

        object = -1;
        for (i = 1; i < argc; i++)
                if (strcmp(argv[i], "object") == 0)
                        object = i;

        if (object == -1) {
                snprintf(errstr, buflen, "Rule must contain an object");
                return (-1);
        }

        /* Search forward for mode. */
        mode = -1;
        for (i = object; i < argc; i++)
                if (strcmp(argv[i], "mode") == 0)
                        mode = i;

        if (mode == -1) {
                snprintf(errstr, buflen, "Rule must contain mode");
                return (-1);
        }

        subject_elements_length = object - subject - 1;
        object_elements = object + 1;
        object_elements_length = mode - object_elements;
        mode_elements = mode + 1;
        mode_elements_length = argc - mode_elements;

        error = bsde_parse_subject(subject_elements_length,
            argv + subject_elements, &rule->mbr_subject, buflen, errstr);
        if (error)
                return (-1);

        error = bsde_parse_object(object_elements_length,
            argv + object_elements, &rule->mbr_object, buflen, errstr);
        if (error)
                return (-1);

        error = bsde_parse_mode(mode_elements_length, argv + mode_elements,
            &rule->mbr_mode, buflen, errstr);
        if (error)
                return (-1);

        return (0);
}

int
bsde_parse_rule_string(const char *string, struct mac_bsdextended_rule *rule,
    size_t buflen, char *errstr)
{
        char *stringdup, *stringp, *argv[100], **ap;
        int argc, error;

        stringp = stringdup = strdup(string);
        while (*stringp == ' ' || *stringp == '\t')
                stringp++;

        argc = 0;
        for (ap = argv; (*ap = strsep(&stringp, " \t")) != NULL;) {
                argc++;
                if (**ap != '\0')
                        if (++ap >= &argv[100])
                                break;
        }

        error = bsde_parse_rule(argc, argv, rule, buflen, errstr);

        free(stringdup);

        return (error);
}

int
bsde_get_mib(const char *string, int *name, size_t *namelen)
{
        size_t len;
        int error;

        len = *namelen;
        error = sysctlnametomib(string, name, &len);
        if (error)
                return (error);

        *namelen = len;
        return (0);
}

static int
bsde_check_version(size_t buflen, char *errstr)
{
        size_t len;
        int error;
        int version;

        len = sizeof(version);
        error = sysctlbyname(MIB ".rule_version", &version, &len, NULL, 0);
        if (error) {
                snprintf(errstr, buflen, "version check failed: %s",
                    strerror(errno));
                return (-1);
        }
        if (version != MB_VERSION) {
                snprintf(errstr, buflen, "module v%d != library v%d",
                    version, MB_VERSION);
                return (-1);
        }
        return (0);
}

int
bsde_get_rule_count(size_t buflen, char *errstr)
{
        size_t len;
        int error;
        int rule_count;

        len = sizeof(rule_count);
        error = sysctlbyname(MIB ".rule_count", &rule_count, &len, NULL, 0);
        if (error) {
                snprintf(errstr, buflen, "%s", strerror(errno));
                return (-1);
        }
        if (len != sizeof(rule_count)) {
                snprintf(errstr, buflen, "Data error in %s.rule_count",
                    MIB);
                return (-1);
        }

        return (rule_count);
}

int
bsde_get_rule_slots(size_t buflen, char *errstr)
{
        size_t len;
        int error;
        int rule_slots;

        len = sizeof(rule_slots);
        error = sysctlbyname(MIB ".rule_slots", &rule_slots, &len, NULL, 0);
        if (error) {
                snprintf(errstr, buflen, "%s", strerror(errno));
                return (-1);
        }
        if (len != sizeof(rule_slots)) {
                snprintf(errstr, buflen, "Data error in %s.rule_slots", MIB);
                return (-1);
        }

        return (rule_slots);
}

/*
 * Returns 0 for success;
 * Returns -1 for failure;
 * Returns -2 for not present
 */
int
bsde_get_rule(int rulenum, struct mac_bsdextended_rule *rule, size_t errlen,
    char *errstr)
{
        int name[10];
        size_t len, size;
        int error;

        if (bsde_check_version(errlen, errstr) != 0)
                return (-1);

        len = 10;
        error = bsde_get_mib(MIB ".rules", name, &len);
        if (error) {
                snprintf(errstr, errlen, "%s: %s", MIB ".rules",
                    strerror(errno));
                return (-1);
        }

        size = sizeof(*rule);
        name[len] = rulenum;
        len++;
        error = sysctl(name, len, rule, &size, NULL, 0);
        if (error  == -1 && errno == ENOENT)
                return (-2);
        if (error) {
                snprintf(errstr, errlen, "%s.%d: %s", MIB ".rules",
                    rulenum, strerror(errno));
                return (-1);
        } else if (size != sizeof(*rule)) {
                snprintf(errstr, errlen, "Data error in %s.%d: %s",
                    MIB ".rules", rulenum, strerror(errno));
                return (-1);
        }

        return (0);
}

int
bsde_delete_rule(int rulenum, size_t buflen, char *errstr)
{
        struct mac_bsdextended_rule rule;
        int name[10];
        size_t len;
        int error;

        if (bsde_check_version(buflen, errstr) != 0)
                return (-1);

        len = 10;
        error = bsde_get_mib(MIB ".rules", name, &len);
        if (error) {
                snprintf(errstr, buflen, "%s: %s", MIB ".rules",
                    strerror(errno));
                return (-1);
        }

        name[len] = rulenum;
        len++;

        error = sysctl(name, len, NULL, NULL, &rule, 0);
        if (error) {
                snprintf(errstr, buflen, "%s.%d: %s", MIB ".rules",
                    rulenum, strerror(errno));
                return (-1);
        }

        return (0);
}

int
bsde_set_rule(int rulenum, struct mac_bsdextended_rule *rule, size_t buflen,
    char *errstr)
{
        int name[10];
        size_t len;
        int error;

        if (bsde_check_version(buflen, errstr) != 0)
                return (-1);

        len = 10;
        error = bsde_get_mib(MIB ".rules", name, &len);
        if (error) {
                snprintf(errstr, buflen, "%s: %s", MIB ".rules",
                    strerror(errno));
                return (-1);
        }

        name[len] = rulenum;
        len++;

        error = sysctl(name, len, NULL, NULL, rule, sizeof(*rule));
        if (error) {
                snprintf(errstr, buflen, "%s.%d: %s", MIB ".rules",
                    rulenum, strerror(errno));
                return (-1);
        }

        return (0);
}

int
bsde_add_rule(int *rulenum, struct mac_bsdextended_rule *rule, size_t buflen,
    char *errstr)
{
        char charstr[BUFSIZ];
        int name[10];
        size_t len;
        int error, rule_slots;

        if (bsde_check_version(buflen, errstr) != 0)
                return (-1);

        len = 10;
        error = bsde_get_mib(MIB ".rules", name, &len);
        if (error) {
                snprintf(errstr, buflen, "%s: %s", MIB ".rules",
                    strerror(errno));
                return (-1);
        }

        rule_slots = bsde_get_rule_slots(BUFSIZ, charstr);
        if (rule_slots == -1) {
                snprintf(errstr, buflen, "unable to get rule slots: %s",
                    strerror(errno));
                return (-1);
        }

        name[len] = rule_slots;
        len++;

        error = sysctl(name, len, NULL, NULL, rule, sizeof(*rule));
        if (error) {
                snprintf(errstr, buflen, "%s.%d: %s", MIB ".rules",
                    rule_slots, strerror(errno));
                return (-1);
        }

        if (rulenum != NULL)
                *rulenum = rule_slots;

        return (0);
}