freebsd-dev/sbin/mount_umap/mount_umap.c
Garrett Wollman f73b709a01 Use the correct file pointer when reading the group id map file. The old
code tried to read the group id map from the user id file, and thus would
never actually allow a umapfs to be mounted.  (!)
1995-06-13 17:42:07 +00:00

245 lines
7.1 KiB
C

/*
* Copyright (c) 1992, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*/
#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1992, 1993, 1994\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)mount_umap.c 8.3 (Berkeley) 3/27/94";
#endif /* not lint */
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <miscfs/umapfs/umap.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "mntopts.h"
#define ROOTUSER 0
/*
* This define controls whether any user but the superuser can own and
* write mapfiles. If other users can, system security can be gravely
* compromised. If this is not a concern, undefine SECURITY.
*/
#define MAPSECURITY 1
/*
* This routine provides the user interface to mounting a umap layer.
* It takes 4 mandatory parameters. The mandatory arguments are the place
* where the next lower level is mounted, the place where the umap layer is to
* be mounted, the name of the user mapfile, and the name of the group
* mapfile. The routine checks the ownerships and permissions on the
* mapfiles, then opens and reads them. Then it calls mount(), which
* will, in turn, call the umap version of mount.
*/
struct mntopt mopts[] = {
MOPT_STDOPTS,
{ NULL }
};
void usage __P((void));
int
main(argc, argv)
int argc;
char *argv[];
{
static char not[] = "; not mounted.";
struct stat statbuf;
struct umap_args args;
FILE *fp, *gfp;
u_long gmapdata[GMAPFILEENTRIES][2], mapdata[MAPFILEENTRIES][2];
int ch, count, gnentries, mntflags, nentries;
char *gmapfile, *mapfile, *source, *target, buf[20];
struct vfsconf *vfc;
mntflags = 0;
mapfile = gmapfile = NULL;
while ((ch = getopt(argc, argv, "g:o:u:")) != EOF)
switch (ch) {
case 'g':
gmapfile = optarg;
break;
case 'o':
getmntopts(optarg, mopts, &mntflags, 0);
break;
case 'u':
mapfile = optarg;
break;
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
if (argc != 2 || mapfile == NULL || gmapfile == NULL)
usage();
source = argv[0];
target = argv[1];
/* Read in uid mapping data. */
if ((fp = fopen(mapfile, "r")) == NULL)
err(1, "%s%s", mapfile, not);
#ifdef MAPSECURITY
/*
* Check that group and other don't have write permissions on
* this mapfile, and that the mapfile belongs to root.
*/
if (fstat(fileno(fp), &statbuf))
err(1, "%s%s", mapfile, not);
if (statbuf.st_mode & S_IWGRP || statbuf.st_mode & S_IWOTH) {
strmode(statbuf.st_mode, buf);
err(1, "%s: improper write permissions (%s)%s",
mapfile, buf, not);
}
if (statbuf.st_uid != ROOTUSER)
errx(1, "%s does not belong to root%s", mapfile, not);
#endif /* MAPSECURITY */
if ((fscanf(fp, "%d\n", &nentries)) != 1)
errx(1, "%s: nentries not found%s", mapfile, not);
if (nentries > MAPFILEENTRIES)
errx(1,
"maximum number of entries is %d%s", MAPFILEENTRIES, not);
#if 0
(void)printf("reading %d entries\n", nentries);
#endif
for (count = 0; count < nentries; ++count) {
if ((fscanf(fp, "%lu %lu\n",
&(mapdata[count][0]), &(mapdata[count][1]))) != 2) {
if (ferror(fp))
err(1, "%s%s", mapfile, not);
if (feof(fp))
errx(1, "%s: unexpected end-of-file%s",
mapfile, not);
errx(1, "%s: illegal format (line %d)%s",
mapfile, count + 2, not);
}
#if 0
/* Fix a security hole. */
if (mapdata[count][1] == 0)
errx(1, "mapping id 0 not permitted (line %d)%s",
count + 2, not);
#endif
}
/* Read in gid mapping data. */
if ((gfp = fopen(gmapfile, "r")) == NULL)
err(1, "%s%s", gmapfile, not);
#ifdef MAPSECURITY
/*
* Check that group and other don't have write permissions on
* this group mapfile, and that the file belongs to root.
*/
if (fstat(fileno(gfp), &statbuf))
err(1, "%s%s", gmapfile, not);
if (statbuf.st_mode & S_IWGRP || statbuf.st_mode & S_IWOTH) {
strmode(statbuf.st_mode, buf);
err(1, "%s: improper write permissions (%s)%s",
gmapfile, buf, not);
}
if (statbuf.st_uid != ROOTUSER)
errx(1, "%s does not belong to root%s", gmapfile, not);
#endif /* MAPSECURITY */
if ((fscanf(gfp, "%d\n", &gnentries)) != 1)
errx(1, "nentries not found%s", gmapfile, not);
if (gnentries > MAPFILEENTRIES)
errx(1,
"maximum number of entries is %d%s", GMAPFILEENTRIES, not);
#if 0
(void)printf("reading %d group entries\n", gnentries);
#endif
for (count = 0; count < gnentries; ++count)
if ((fscanf(gfp, "%lu %lu\n",
&(gmapdata[count][0]), &(gmapdata[count][1]))) != 2) {
if (ferror(gfp))
err(1, "%s%s", gmapfile, not);
if (feof(gfp))
errx(1, "%s: unexpected end-of-file%s",
gmapfile, not);
errx(1, "%s: illegal format (line %d)%s",
gmapfile, count + 2, not);
}
/* Setup mount call args. */
args.target = source;
args.nentries = nentries;
args.mapdata = mapdata;
args.gnentries = gnentries;
args.gmapdata = gmapdata;
vfc = getvfsbyname("umap");
if(!vfc && vfsisloadable("umap")) {
if(vfsload("umap"))
err(1, "vfsload(umap)");
endvfsent(); /* flush cache */
vfc = getvfsbyname("umap");
}
if (!vfc) {
errx(1, "umap filesystem not available");
}
if (mount(vfc->vfc_index, argv[1], mntflags, &args))
err(1, NULL);
exit(0);
}
void
usage()
{
(void)fprintf(stderr,
"usage: mount_umap [-o options] -u usermap -g groupmap target_fs mount_point\n");
exit(1);
}