mount_tmpfs.c revision 1.11
1 /* $NetBSD: mount_tmpfs.c,v 1.11 2006/02/11 05:49:48 christos Exp $ */ 2 3 /* 4 * Copyright (c) 2005 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Julio M. Merino Vidal, developed as part of Google's Summer of Code 9 * 2005 program. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 #include <sys/cdefs.h> 41 #ifndef lint 42 __RCSID("$NetBSD: mount_tmpfs.c,v 1.11 2006/02/11 05:49:48 christos Exp $"); 43 #endif /* not lint */ 44 45 #define __POOL_EXPOSE 46 #include <sys/param.h> 47 #include <sys/mount.h> 48 #include <sys/stat.h> 49 50 #include <fs/tmpfs/tmpfs.h> 51 52 #include <ctype.h> 53 #include <err.h> 54 #include <errno.h> 55 #include <grp.h> 56 #include <mntopts.h> 57 #include <pwd.h> 58 #include <stdio.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include <unistd.h> 62 63 /* --------------------------------------------------------------------- */ 64 65 static const struct mntopt mopts[] = { 66 MOPT_STDOPTS, 67 MOPT_GETARGS, 68 { NULL } 69 }; 70 71 /* --------------------------------------------------------------------- */ 72 73 static int mount_tmpfs(int argc, char **argv); 74 static void usage(void); 75 static int dehumanize_group(const char *str, gid_t *gid); 76 static int dehumanize_mode(const char *str, mode_t *mode); 77 static int dehumanize_off(const char *str, off_t *size); 78 static int dehumanize_user(const char *str, uid_t *uid); 79 80 /* --------------------------------------------------------------------- */ 81 82 int 83 mount_tmpfs(int argc, char *argv[]) 84 { 85 char canon_dir[MAXPATHLEN]; 86 int gidset, modeset, uidset; /* Ought to be 'bool'. */ 87 int ch, mntflags; 88 gid_t gid; 89 uid_t uid; 90 mode_t mode; 91 off_t offtmp; 92 mntoptparse_t mo; 93 struct tmpfs_args args; 94 struct stat sb; 95 96 setprogname(argv[0]); 97 98 /* Set default values for mount point arguments. */ 99 args.ta_version = TMPFS_ARGS_VERSION; 100 args.ta_size_max = 0; 101 args.ta_nodes_max = 0; 102 mntflags = 0; 103 104 gidset = 0; gid = 0; 105 uidset = 0; uid = 0; 106 modeset = 0; mode = 0; 107 108 optind = optreset = 1; 109 while ((ch = getopt(argc, argv, "g:m:n:o:s:u:")) != -1 ) { 110 switch (ch) { 111 case 'g': 112 if (!dehumanize_group(optarg, &gid)) { 113 errx(EXIT_FAILURE, "failed to parse group " 114 "'%s'", optarg); 115 /* NOTREACHED */ 116 } 117 gidset = 1; 118 break; 119 120 case 'm': 121 if (!dehumanize_mode(optarg, &mode)) { 122 errx(EXIT_FAILURE, "failed to parse mode " 123 "'%s'", optarg); 124 /* NOTREACHED */ 125 } 126 modeset = 1; 127 break; 128 129 case 'n': 130 if (!dehumanize_off(optarg, &offtmp)) { 131 errx(EXIT_FAILURE, "failed to parse size " 132 "'%s'", optarg); 133 /* NOTREACHED */ 134 } 135 args.ta_nodes_max = offtmp; 136 break; 137 138 case 'o': 139 mo = getmntopts(optarg, mopts, &mntflags, 0); 140 freemntopts(mo); 141 break; 142 143 case 's': 144 if (!dehumanize_off(optarg, &offtmp)) { 145 errx(EXIT_FAILURE, "failed to parse size " 146 "'%s'", optarg); 147 /* NOTREACHED */ 148 } 149 args.ta_size_max = offtmp; 150 break; 151 152 case 'u': 153 if (!dehumanize_user(optarg, &uid)) { 154 errx(EXIT_FAILURE, "failed to parse user " 155 "'%s'", optarg); 156 /* NOTREACHED */ 157 } 158 uidset = 1; 159 break; 160 161 case '?': 162 default: 163 usage(); 164 /* NOTREACHED */ 165 } 166 } 167 argc -= optind; 168 argv += optind; 169 170 if (argc != 2) { 171 usage(); 172 /* NOTREACHED */ 173 } 174 175 if (realpath(argv[1], canon_dir) == NULL) { 176 err(EXIT_FAILURE, "realpath %s", argv[0]); 177 /* NOTREACHED */ 178 } 179 180 if (strncmp(argv[1], canon_dir, MAXPATHLEN) != 0) { 181 warnx("\"%s\" is a relative path", argv[0]); 182 warnx("using \"%s\" instead", canon_dir); 183 } 184 185 if (stat(canon_dir, &sb) == -1) { 186 err(EXIT_FAILURE, "cannot stat"); 187 /* NOTREACHED */ 188 } 189 args.ta_root_uid = uidset ? uid : sb.st_uid; 190 args.ta_root_gid = gidset ? gid : sb.st_gid; 191 args.ta_root_mode = modeset ? mode : sb.st_mode; 192 193 if (mount(MOUNT_TMPFS, canon_dir, mntflags, &args)) { 194 err(EXIT_FAILURE, "tmpfs on %s", canon_dir); 195 /* NOTREACHED */ 196 } 197 if (mntflags & MNT_GETARGS) { 198 struct passwd *pw; 199 struct group *gr; 200 201 (void)printf("version=%d\n", args.ta_version); 202 (void)printf("size_max=%" PRIuMAX "\n", 203 (uintmax_t)args.ta_size_max); 204 (void)printf("nodes_max=%" PRIuMAX "\n", 205 (uintmax_t)args.ta_nodes_max); 206 207 pw = getpwuid(args.ta_root_uid); 208 if (pw == NULL) 209 (void)printf("root_uid=%" PRIuMAX "\n", 210 (uintmax_t)args.ta_root_uid); 211 else 212 (void)printf("root_uid=%s\n", pw->pw_name); 213 214 gr = getgrgid(args.ta_root_gid); 215 if (gr == NULL) 216 (void)printf("root_gid=%" PRIuMAX "\n", 217 (uintmax_t)args.ta_root_gid); 218 else 219 (void)printf("root_gid=%s\n", gr->gr_name); 220 221 (void)printf("root_mode=%o\n", args.ta_root_mode); 222 } 223 224 return EXIT_SUCCESS; 225 } 226 227 /* --------------------------------------------------------------------- */ 228 229 static void 230 usage(void) 231 { 232 (void)fprintf(stderr, 233 "Usage: %s [-g group] [-m mode] [-n nodes] [-o options] [-s size]\n" 234 " [-u user] tmpfs mountpoint\n", getprogname()); 235 exit(1); 236 } 237 238 /* --------------------------------------------------------------------- */ 239 240 /* 241 * Obtains a GID number based on the contents of 'str'. If it is a string 242 * and is found in group(5), its corresponding ID is used. Otherwise, an 243 * attempt is made to convert the string to a number and use that as a GID. 244 * In case of success, true is returned and *gid holds the GID value. 245 * Otherwise, false is returned and *gid is untouched. 246 */ 247 static int 248 dehumanize_group(const char *str, gid_t *gid) 249 { 250 int error; 251 struct group *gr; 252 253 gr = getgrnam(str); 254 if (gr != NULL) { 255 *gid = gr->gr_gid; 256 error = 1; 257 } else { 258 char *ep; 259 unsigned long tmp; 260 261 errno = 0; 262 tmp = strtoul(str, &ep, 0); 263 if (str[0] == '\0' || *ep != '\0') 264 error = 0; /* Not a number. */ 265 else if (errno == ERANGE && 266 (tmp == LONG_MAX || tmp == LONG_MIN)) 267 error = 0; /* Out of range. */ 268 else { 269 *gid = (gid_t)tmp; 270 error = 1; 271 } 272 } 273 274 return error; 275 } 276 277 /* --------------------------------------------------------------------- */ 278 279 /* 280 * Obtains a mode number based on the contents of 'str'. 281 * In case of success, true is returned and *mode holds the mode value. 282 * Otherwise, false is returned and *mode is untouched. 283 */ 284 static int 285 dehumanize_mode(const char *str, mode_t *mode) 286 { 287 char *ep; 288 int error; 289 long tmp; 290 291 errno = 0; 292 tmp = strtol(str, &ep, 8); 293 if (str[0] == '\0' || *ep != '\0') 294 error = 0; /* Not a number. */ 295 else if (errno == ERANGE && 296 (tmp == LONG_MAX || tmp == LONG_MIN)) 297 error = 0; /* Out of range. */ 298 else { 299 *mode = (mode_t)tmp; 300 error = 1; 301 } 302 303 return error; 304 } 305 306 /* --------------------------------------------------------------------- */ 307 308 /* 309 * Converts the number given in 'str', which may be given in a humanized 310 * form (as described in humanize_number(3), but with some limitations), 311 * to a file size (off_t) without units. 312 * In case of success, true is returned and *size holds the value. 313 * Otherwise, false is returned and *size is untouched. 314 */ 315 static int 316 dehumanize_off(const char *str, off_t *size) 317 { 318 char *ep, unit; 319 const char *delimit; 320 long multiplier; 321 long long tmp, tmp2; 322 size_t len; 323 324 len = strlen(str); 325 if (len < 1) 326 return 0; 327 328 multiplier = 1; 329 330 unit = str[len - 1]; 331 if (isalpha((int)unit)) { 332 switch (tolower((int)unit)) { 333 case 'b': 334 multiplier = 1; 335 break; 336 337 case 'k': 338 multiplier = 1024; 339 break; 340 341 case 'm': 342 multiplier = 1024 * 1024; 343 break; 344 345 case 'g': 346 multiplier = 1024 * 1024 * 1024; 347 break; 348 349 default: 350 return 0; /* Invalid suffix. */ 351 } 352 353 delimit = &str[len - 1]; 354 } else 355 delimit = NULL; 356 357 errno = 0; 358 tmp = strtoll(str, &ep, 10); 359 if (str[0] == '\0' || (ep != delimit && *ep != '\0')) 360 return 0; /* Not a number. */ 361 else if (errno == ERANGE && (tmp == LONG_MAX || tmp == LONG_MIN)) 362 return 0; /* Out of range. */ 363 364 tmp2 = tmp * multiplier; 365 tmp2 = tmp2 / multiplier; 366 if (tmp != tmp2) 367 return 0; /* Out of range. */ 368 *size = tmp * multiplier; 369 370 return 1; 371 } 372 373 /* --------------------------------------------------------------------- */ 374 375 /* 376 * Obtains a UID number based on the contents of 'str'. If it is a string 377 * and is found in passwd(5), its corresponding ID is used. Otherwise, an 378 * attempt is made to convert the string to a number and use that as a UID. 379 * In case of success, true is returned and *uid holds the UID value. 380 * Otherwise, false is returned and *uid is untouched. 381 */ 382 static int 383 dehumanize_user(const char *str, uid_t *uid) 384 { 385 int error; 386 struct passwd *pw; 387 388 pw = getpwnam(str); 389 if (pw != NULL) { 390 *uid = pw->pw_uid; 391 error = 1; 392 } else { 393 char *ep; 394 unsigned long tmp; 395 396 errno = 0; 397 tmp = strtoul(str, &ep, 0); 398 if (str[0] == '\0' || *ep != '\0') 399 error = 0; /* Not a number. */ 400 else if (errno == ERANGE && 401 (tmp == LONG_MAX || tmp == LONG_MIN)) 402 error = 0; /* Out of range. */ 403 else { 404 *uid = (uid_t)tmp; 405 error = 1; 406 } 407 } 408 409 return error; 410 } 411 412 /* --------------------------------------------------------------------- */ 413 414 #ifndef MOUNT_NOMAIN 415 int 416 main(int argc, char *argv[]) 417 { 418 419 return mount_tmpfs(argc, argv); 420 } 421 #endif 422
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