mount_umap.c revision 1.14
1 /* $NetBSD: mount_umap.c,v 1.14 2003/08/07 10:04:32 agc Exp $ */ 2 3 /* 4 * Copyright (c) 1992, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software donated to Berkeley by 8 * Jan-Simon Pendry. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 #ifndef lint 37 __COPYRIGHT("@(#) Copyright (c) 1992, 1993, 1994\n\ 38 The Regents of the University of California. All rights reserved.\n"); 39 #endif /* not lint */ 40 41 #ifndef lint 42 #if 0 43 static char sccsid[] = "@(#)mount_umap.c 8.5 (Berkeley) 4/26/95"; 44 #else 45 __RCSID("$NetBSD: mount_umap.c,v 1.14 2003/08/07 10:04:32 agc Exp $"); 46 #endif 47 #endif /* not lint */ 48 49 #include <sys/param.h> 50 #include <sys/mount.h> 51 #include <sys/stat.h> 52 53 #include <miscfs/umapfs/umap.h> 54 55 #include <err.h> 56 #include <stdio.h> 57 #include <stdlib.h> 58 #include <string.h> 59 #include <unistd.h> 60 61 #include <mntopts.h> 62 63 #define ROOTUSER 0 64 /* 65 * This define controls whether any user but the superuser can own and 66 * write mapfiles. If other users can, system security can be gravely 67 * compromised. If this is not a concern, undefine SECURITY. 68 */ 69 #define MAPSECURITY 1 70 71 /* 72 * This routine provides the user interface to mounting a umap layer. 73 * It takes 4 mandatory parameters. The mandatory arguments are the place 74 * where the next lower level is mounted, the place where the umap layer is to 75 * be mounted, the name of the user mapfile, and the name of the group 76 * mapfile. The routine checks the ownerships and permissions on the 77 * mapfiles, then opens and reads them. Then it calls mount(), which 78 * will, in turn, call the umap version of mount. 79 */ 80 81 static const struct mntopt mopts[] = { 82 MOPT_STDOPTS, 83 { NULL } 84 }; 85 86 int main __P((int, char *[])); 87 int mount_umap __P((int argc, char **argv)); 88 static void usage __P((void)); 89 90 #ifndef MOUNT_NOMAIN 91 int 92 main(argc, argv) 93 int argc; 94 char **argv; 95 { 96 return mount_umap(argc, argv); 97 } 98 #endif 99 100 int 101 mount_umap(argc, argv) 102 int argc; 103 char *argv[]; 104 { 105 static char not[] = "; not mounted."; 106 struct stat statbuf; 107 struct umap_args args; 108 FILE *fp, *gfp; 109 long d1, d2; 110 u_long mapdata[MAPFILEENTRIES][2]; 111 u_long gmapdata[GMAPFILEENTRIES][2]; 112 int ch, count, gnentries, mntflags, nentries; 113 char *gmapfile, *mapfile, *source, *target, buf[20]; 114 115 mntflags = 0; 116 mapfile = gmapfile = NULL; 117 while ((ch = getopt(argc, argv, "g:o:u:")) != -1) 118 switch (ch) { 119 case 'g': 120 gmapfile = optarg; 121 break; 122 case 'o': 123 getmntopts(optarg, mopts, &mntflags, 0); 124 break; 125 case 'u': 126 mapfile = optarg; 127 break; 128 case '?': 129 default: 130 usage(); 131 } 132 argc -= optind; 133 argv += optind; 134 135 if (argc != 2 || mapfile == NULL || gmapfile == NULL) 136 usage(); 137 138 source = argv[0]; 139 target = argv[1]; 140 141 /* Read in uid mapping data. */ 142 if ((fp = fopen(mapfile, "r")) == NULL) 143 err(1, "%s%s", mapfile, not); 144 145 #ifdef MAPSECURITY 146 /* 147 * Check that group and other don't have write permissions on 148 * this mapfile, and that the mapfile belongs to root. 149 */ 150 if (fstat(fileno(fp), &statbuf)) 151 err(1, "%s%s", mapfile, not); 152 if (statbuf.st_mode & S_IWGRP || statbuf.st_mode & S_IWOTH) { 153 strmode(statbuf.st_mode, buf); 154 err(1, "%s: improper write permissions (%s)%s", 155 mapfile, buf, not); 156 } 157 if (statbuf.st_uid != ROOTUSER) 158 errx(1, "%s does not belong to root%s", mapfile, not); 159 #endif /* MAPSECURITY */ 160 161 if ((fscanf(fp, "%d\n", &nentries)) != 1) 162 errx(1, "%s: nentries not found%s", mapfile, not); 163 if (nentries > MAPFILEENTRIES) 164 errx(1, 165 "maximum number of entries is %d%s", MAPFILEENTRIES, not); 166 #if 0 167 (void)printf("reading %d entries\n", nentries); 168 #endif 169 for (count = 0; count < nentries; ++count) { 170 if ((fscanf(fp, "%lu %lu\n", &d1, &d2)) != 2) { 171 if (ferror(fp)) 172 err(1, "%s%s", mapfile, not); 173 if (feof(fp)) 174 errx(1, "%s: unexpected end-of-file%s", 175 mapfile, not); 176 errx(1, "%s: illegal format (line %d)%s", 177 mapfile, count + 2, not); 178 } 179 mapdata[count][0] = d1; 180 mapdata[count][1] = d2; 181 #if 0 182 /* Fix a security hole. */ 183 if (mapdata[count][1] == 0) 184 errx(1, "mapping id 0 not permitted (line %d)%s", 185 count + 2, not); 186 #endif 187 } 188 189 /* Read in gid mapping data. */ 190 if ((gfp = fopen(gmapfile, "r")) == NULL) 191 err(1, "%s%s", gmapfile, not); 192 193 #ifdef MAPSECURITY 194 /* 195 * Check that group and other don't have write permissions on 196 * this group mapfile, and that the file belongs to root. 197 */ 198 if (fstat(fileno(gfp), &statbuf)) 199 err(1, "%s%s", gmapfile, not); 200 if (statbuf.st_mode & S_IWGRP || statbuf.st_mode & S_IWOTH) { 201 strmode(statbuf.st_mode, buf); 202 err(1, "%s: improper write permissions (%s)%s", 203 gmapfile, buf, not); 204 } 205 if (statbuf.st_uid != ROOTUSER) 206 errx(1, "%s does not belong to root%s", gmapfile, not); 207 #endif /* MAPSECURITY */ 208 209 if ((fscanf(gfp, "%d\n", &gnentries)) != 1) 210 errx(1, "nentries not found%s", not); 211 if (gnentries > MAPFILEENTRIES) 212 errx(1, 213 "maximum number of entries is %d%s", GMAPFILEENTRIES, not); 214 #if 0 215 (void)printf("reading %d group entries\n", gnentries); 216 #endif 217 218 for (count = 0; count < gnentries; ++count) { 219 if ((fscanf(gfp, "%lu %lu\n", 220 &(gmapdata[count][0]), &(gmapdata[count][1]))) != 2) { 221 if (ferror(gfp)) 222 err(1, "%s%s", gmapfile, not); 223 if (feof(gfp)) 224 errx(1, "%s: unexpected end-of-file%s", 225 gmapfile, not); 226 errx(1, "%s: illegal format (line %d)%s", 227 gmapfile, count + 2, not); 228 } 229 } 230 231 232 /* Setup mount call args. */ 233 args.la.target = source; 234 args.nentries = nentries; 235 args.mapdata = mapdata; 236 args.gnentries = gnentries; 237 args.gmapdata = gmapdata; 238 239 if (mount(MOUNT_UMAP, argv[1], mntflags, &args)) 240 err(1, "%s on %s", source, argv[1]); 241 if (mntflags & MNT_GETARGS) { 242 printf("nentries=%d, gnentries=%d\n", args.nentries, 243 args.gnentries); 244 } 245 exit(0); 246 } 247 248 static void 249 usage() 250 { 251 (void)fprintf(stderr, 252 "usage: mount_umap [-o options] -u usermap -g groupmap target_fs mount_point\n"); 253 exit(1); 254 } 255
Indexes created Tue Oct 14 15:09:51 GMT 2025