/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

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

#include <db.h>
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

static void      db_build(char **);
static void      dounlink(void);
static void      usage(void);

static DB       *capdbp;
static int       verbose;
static char     *capname, buf[8 * 1024];

static HASHINFO openinfo = {
        4096,           /* bsize */
        0,              /* ffactor */
        0,              /* nelem */
        0,              /* cachesize */
        NULL,           /* hash() */
        0               /* lorder */
};

/*
 * Mkcapdb creates a capability hash database for quick retrieval of capability
 * records.  The database contains 2 types of entries: records and references
 * marked by the first byte in the data.  A record entry contains the actual
 * capability record whereas a reference contains the name (key) under which
 * the correct record is stored.
 */
int
main(int argc, char *argv[])
{
        int byteorder, c;

        capname = NULL;
        byteorder = 0;
        while ((c = getopt(argc, argv, "bf:lv")) != -1) {
                switch(c) {
                case 'b':
                case 'l':
                        if (byteorder != 0)
                                usage();
                        byteorder = c == 'b' ? 4321 : 1234;
                        break;
                case 'f':
                        capname = optarg;
                        break;
                case 'v':
                        verbose = 1;
                        break;
                case '?':
                default:
                        usage();
                }
        }
        argc -= optind;
        argv += optind;

        if (*argv == NULL)
                usage();

        /* Set byte order. */
        openinfo.lorder = byteorder;

        /*
         * The database file is the first argument if no name is specified.
         * Make arrangements to unlink it if exit badly.
         */
        (void)snprintf(buf, sizeof(buf), "%s.db", capname ? capname : *argv);
        if ((capname = strdup(buf)) == NULL)
                errx(1, "strdup failed");
        if ((capdbp = dbopen(capname, O_CREAT | O_TRUNC | O_RDWR,
            DEFFILEMODE, DB_HASH, &openinfo)) == NULL)
                err(1, "%s", buf);

        if (atexit(dounlink))
                err(1, "atexit");

        db_build(argv);

        if (capdbp->close(capdbp) < 0)
                err(1, "%s", capname);
        capname = NULL;
        exit(0);
}

static void
dounlink(void)
{
        if (capname != NULL)
                (void)unlink(capname);
}

/*
 * Any changes to these definitions should be made also in the getcap(3)
 * library routines.
 */
#define RECOK   (char)0
#define TCERR   (char)1
#define SHADOW  (char)2

/*
 * Db_build() builds the name and capability databases according to the
 * details above.
 */
static void
db_build(char **ifiles)
{
        DBT key, data;
        recno_t reccnt;
        size_t len, bplen;
        int st;
        char *bp, *p, *t;

        data.data = NULL;
        key.data = NULL;
        for (reccnt = 0, bplen = 0; (st = cgetnext(&bp, ifiles)) > 0;) {

                /*
                 * Allocate enough memory to store record, terminating
                 * NULL and one extra byte.
                 */
                len = strlen(bp);
                if (bplen <= len + 2) {
                        bplen += MAX(256, len + 2);
                        if ((data.data = realloc(data.data, bplen)) == NULL)
                                errx(1, "malloc failed");
                }

                /* Find the end of the name field. */
                if ((p = strchr(bp, ':')) == NULL) {
                        warnx("no name field: %.*s", (int)MIN(len, 20), bp);
                        continue;
                }

                /* First byte of stored record indicates status. */
                switch(st) {
                case 1:
                        ((char *)(data.data))[0] = RECOK;
                        break;
                case 2:
                        ((char *)(data.data))[0] = TCERR;
                        warnx("record not tc expanded: %.*s", (int)(p - bp),
                            bp);
                        break;
                }

                /* Create the stored record. */
                memmove(&((u_char *)(data.data))[1], bp, len + 1);
                data.size = len + 2;

                /* Store the record under the name field. */
                key.data = bp;
                key.size = p - bp;

                switch(capdbp->put(capdbp, &key, &data, R_NOOVERWRITE)) {
                case -1:
                        err(1, "put");
                        /* NOTREACHED */
                case 1:
                        warnx("ignored duplicate: %.*s",
                            (int)key.size, (char *)key.data);
                        continue;
                }
                ++reccnt;

                /* If only one name, ignore the rest. */
                *p = '\0';
                if (strchr(bp, '|') == NULL)
                        continue;
                *p = ':';

                /* The rest of the names reference the entire name. */
                ((char *)(data.data))[0] = SHADOW;
                memmove(&((u_char *)(data.data))[1], key.data, key.size);
                data.size = key.size + 1;

                /* Store references for other names. */
                for (p = t = bp;; ++p) {
                        if (p > t && (*p == ':' || *p == '|')) {
                                key.size = p - t;
                                key.data = t;
                                switch(capdbp->put(capdbp,
                                    &key, &data, R_NOOVERWRITE)) {
                                case -1:
                                        err(1, "put");
                                        /* NOTREACHED */
                                case 1:
                                        warnx("ignored duplicate: %.*s",
                                            (int)key.size, (char *)key.data);
                                }
                                t = p + 1;
                        }
                        if (*p == ':')
                                break;
                }
        }

        switch(st) {
        case -1:
                err(1, "file argument");
                /* NOTREACHED */
        case -2:
                errx(1, "potential reference loop detected");
                /* NOTREACHED */
        }

        if (verbose)
                (void)printf("cap_mkdb: %d capability records\n", reccnt);
}

static void
usage(void)
{
        (void)fprintf(stderr,
            "usage: cap_mkdb [-b | -l] [-v] [-f outfile] file ...\n");
        exit(1);
}