path: root/usr.bin/cap_mkdb/cap_mkdb.c

/*	$OpenBSD: cap_mkdb.c,v 1.22 2015/12/04 19:15:54 jmc 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);
int	 igetnext(char **, char **);
int	 main(int, char *[]);

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;
		case '?':
		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))
		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);
}