/*      $OpenBSD: cap_mkdb.c,v 1.26 2022/12/04 23:50:47 cheloha Exp $   */
/*      $NetBSD: cap_mkdb.c,v 1.5 1995/09/02 05:47:12 jtc 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.
 */

#include <sys/stat.h>

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

#define MINIMUM(a, b)   (((a) < (b)) ? (a) : (b))
#define MAXIMUM(a, b)   (((a) > (b)) ? (a) : (b))

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

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

HASHINFO openinfo = {
        4096,           /* bsize */
        16,             /* ffactor */
        256,            /* nelem */
        2048 * 1024,    /* cachesize */
        NULL,           /* hash() */
        0               /* lorder */
};

/*
 * cap_mkdb 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;

        if (pledge("stdio rpath wpath cpath", NULL) == -1)
                err(1, "pledge");

        capname = NULL;
        while ((c = getopt(argc, argv, "f:iv")) != -1) {
                switch(c) {
                case 'f':
                        capname = optarg;
                        break;
                case 'v':
                        verbose = 1;
                        break;
                default:
                        usage();
                }
        }
        argc -= optind;
        argv += optind;

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

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

        if (atexit(dounlink) != 0)
                err(1, "atexit");

        db_build(argv);

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

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.
 */
void
db_build(char **ifiles)
{
        DBT key, data;
        recno_t reccnt;
        size_t len, bplen;
        int st;
        char *bp, *p, *t, *capbeg, *capend;

        cgetusedb(0);           /* disable reading of .db files in getcap(3) */

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

                /*
                 * Allocate enough memory to store the size of the record plus
                 * a terminating NULL and one extra byte.
                 */
                len = strlen(bp);
                if (bplen <= len + 2) {
                        int newbplen = bplen + MAXIMUM(256, len + 2);
                        void *newdata;

                        if ((newdata = realloc(data.data, newbplen)) == NULL)
                                err(1, NULL);
                        data.data = newdata;
                        bplen = newbplen;
                }

                /* Find the end of the name field. */
                if ((p = strchr(bp, ':')) == NULL) {
                        warnx("no name field: %.*s", (int)MINIMUM(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. */
                t = (char *)data.data + 1;
                /* Copy the cap name and trailing ':' */
                len = p - bp + 1;
                memcpy(t, bp, len);
                t += len;

                /* Copy entry, collapsing empty fields. */
                capbeg = p + 1;
                while (*capbeg) {
                        /* Skip empty fields. */
                        if ((len = strspn(capbeg, ": \t\n\r")))
                                capbeg += len;

                        /* Find the end of this cap and copy it w/ : */
                        capend = strchr(capbeg, ':');
                        if (capend)
                                len = capend - capbeg + 1;
                        else
                                len = strlen(capbeg);
                        memcpy(t, capbeg, len);
                        t += len;
                        capbeg += len;
                }
                *t = '\0';
                data.size = t - (char *)data.data + 1;

                /* 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;

                                /*
                                 * If this is the last entry and contains any
                                 * spaces, it is a description rather than an
                                 * alias, so skip it and break.
                                 */
                                if (*p != '|' &&
                                    memchr(key.data, ' ', key.size) != NULL)
                                        break;

                                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;
                }
                free(bp);
        }

        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);
}

void
usage(void)
{
        (void)fprintf(stderr,
            "usage: cap_mkdb [-v] [-f outfile] file1 [file2 ...]\n");
        exit(1);
}