/*      $NetBSD: cap_mkdb.c,v 1.30 2021/12/03 13:27:39 andvar Exp $     */

/*-
 * 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.
 */

#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif

#include <sys/cdefs.h>
#if !defined(lint)
__COPYRIGHT("@(#) Copyright (c) 1992, 1993\
 The Regents of the University of California.  All rights reserved.");
#if 0
static char sccsid[] = "@(#)cap_mkdb.c  8.2 (Berkeley) 4/27/95";
#endif
__RCSID("$NetBSD: cap_mkdb.c,v 1.30 2021/12/03 13:27:39 andvar Exp $");
#endif /* not lint */

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

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

static void     db_build(const char **);
static void     dounlink(void);
static void     usage(void) __dead;
static int      count_records(char **);

static DB *capdbp;
static int verbose;
static char *capname, outfile[MAXPATHLEN];

static HASHINFO openinfo = {
        4096,           /* bsize */
        16,             /* ffactor */
        2048,           /* nelem */
        2048 * 1024,    /* 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 c, byteorder;
        char *p;

        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;

        /*
         * Set nelem to twice the value returned by count_record().
         */
        openinfo.nelem = count_records(argv) << 1;

        /*
         * The database file is the first argument if no name is specified.
         * Make arrangements to unlink it if exit badly.
         */
        (void)snprintf(outfile, sizeof(outfile), "%s.db.tmp",
            capname ? capname : *argv);
        if ((capname = strdup(outfile)) == NULL)
                err(1, "strdup");
        p = strrchr(outfile, '.');
        assert(p != NULL);
        *p = '\0';
        (void)unlink(outfile);
        if ((capdbp = dbopen(capname, O_CREAT | O_TRUNC | O_RDWR,
            DEFFILEMODE, DB_HASH, &openinfo)) == NULL)
                err(1, "%s", outfile);

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

        db_build((void *)argv);

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

static void
dounlink(void)
{
        if (capname != NULL)
                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(const char **ifiles)
{
        DBT key, data;
        recno_t reccnt;
        size_t len, bplen;
        int st;
        char *bp, *p, *t, *n;

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

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

                /* 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. */
                (void)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. */
                if ((p = strchr(bp, '|')) == NULL)
                        continue;

                /* The rest of the names reference the entire name. */
                ((char *)(data.data))[0] = SHADOW;
                (void)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: %s [-b|-l] [-v] [-f outfile] file1 [file2 ...]\n",
            getprogname());
        exit(1);
}

/*
 * Count number of records in input files. This does not need
 * to be really accurate (the result is used only as a hint).
 * It seems to match number of records should a cgetnext() be used, though.
 */
static int
count_records(char **list)
{
        FILE *fp;
        char *line;
        size_t len;
        int nelem, slash;

        /* scan input files and count individual records */
        for(nelem = 0, slash = 0; *list && (fp = fopen(*list++, "r")); ) {
                while((line = fgetln(fp, &len)) != NULL) {
                        if (len < 2)
                                continue;
                        if (!isspace((unsigned char) *line) && *line != ':'
                                && *line != '#' && !slash)
                                nelem++;

                        slash = (line[len - 2] == '\\');
                }
                (void)fclose(fp);
        } 

        if (nelem == 0) {
                /* no records found; pass default size hint */
                nelem = 1;
        } else if (!powerof2(nelem)) {
                /* set nelem to nearest bigger power-of-two number */
                int bt = 1;
                while(bt < nelem) bt <<= 1;
                nelem = bt;
        }

        return nelem;
}