mount_tmpfs.c revision 1.3
1 /* $NetBSD: mount_tmpfs.c,v 1.3 2005/09/23 15:36:16 jmmv 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 1.3 2005/09/23 15:36:16 jmmv Exp $"); 43 #endif /* not lint */ 44 45 #include <sys/param.h> 46 #include <sys/mount.h> 47 48 #include <fs/tmpfs/tmpfs.h> 49 50 #include <ctype.h> 51 #include <err.h> 52 #include <errno.h> 53 #include <grp.h> 54 #include <mntopts.h> 55 #include <pwd.h> 56 #include <stdio.h> 57 #include <stdlib.h> 58 #include <string.h> 59 #include <unistd.h> 60 61 /* --------------------------------------------------------------------- */ 62 63 static const struct mntopt mopts[] = { 64 MOPT_STDOPTS, 65 { NULL } 66 }; 67 68 /* --------------------------------------------------------------------- */ 69 70 static int mount_tmpfs(int argc, char **argv); 71 static void usage(void); 72 static int dehumanize_group(const char *str, gid_t *gid); 73 static int dehumanize_mode(const char *str, mode_t *mode); 74 static int dehumanize_off(const char *str, off_t *size); 75 static int dehumanize_user(const char *str, uid_t *uid); 76 77 /* --------------------------------------------------------------------- */ 78 79 int 80 mount_tmpfs(int argc, char *argv[]) 81 { 82 char canon_dir[MAXPATHLEN]; 83 int ch, mntflags; 84 off_t offtmp; 85 mntoptparse_t mo; 86 struct tmpfs_args args; 87 88 setprogname(argv[0]); 89 90 /* Set default values for mount point arguments. */ 91 args.ta_version = TMPFS_ARGS_VERSION; 92 args.ta_size_max = 0; 93 args.ta_nodes_max = 0; 94 args.ta_root_uid = getuid(); 95 args.ta_root_gid = getgid(); 96 args.ta_root_mode = 0755; 97 mntflags = 0; 98 99 optind = optreset = 1; 100 while ((ch = getopt(argc, argv, "g:m:n:o:s:u:")) != -1 ) { 101 switch (ch) { 102 case 'g': 103 if (!dehumanize_group(optarg, &args.ta_root_gid)) { 104 errx(EXIT_FAILURE, "failed to parse group " 105 "'%s'", optarg); 106 /* NOTREACHED */ 107 } 108 break; 109 110 case 'm': 111 if (!dehumanize_mode(optarg, &args.ta_root_mode)) { 112 errx(EXIT_FAILURE, "failed to parse mode " 113 "'%s'", optarg); 114 /* NOTREACHED */ 115 } 116 break; 117 118 case 'n': 119 if (!dehumanize_off(optarg, &offtmp)) { 120 errx(EXIT_FAILURE, "failed to parse size " 121 "'%s'", optarg); 122 /* NOTREACHED */ 123 } 124 args.ta_nodes_max = offtmp; 125 break; 126 127 case 'o': 128 mo = getmntopts(optarg, mopts, &mntflags, 0); 129 freemntopts(mo); 130 break; 131 132 case 's': 133 if (!dehumanize_off(optarg, &offtmp)) { 134 errx(EXIT_FAILURE, "failed to parse size " 135 "'%s'", optarg); 136 /* NOTREACHED */ 137 } 138 args.ta_size_max = offtmp; 139 break; 140 141 case 'u': 142 if (!dehumanize_user(optarg, &args.ta_root_uid)) { 143 errx(EXIT_FAILURE, "failed to parse user " 144 "'%s'", optarg); 145 /* NOTREACHED */ 146 } 147 break; 148 149 case '?': 150 default: 151 usage(); 152 /* NOTREACHED */ 153 } 154 } 155 argc -= optind; 156 argv += optind; 157 158 if (argc != 2) { 159 usage(); 160 /* NOTREACHED */ 161 } 162 163 if (realpath(argv[1], canon_dir) == NULL) { 164 err(EXIT_FAILURE, "realpath %s", argv[0]); 165 /* NOTREACHED */ 166 } 167 168 if (strncmp(argv[1], canon_dir, MAXPATHLEN) != 0) { 169 warnx("\"%s\" is a relative path", argv[0]); 170 warnx("using \"%s\" instead", canon_dir); 171 } 172 173 if (mount(MOUNT_TMPFS, canon_dir, mntflags, &args)) { 174 err(EXIT_FAILURE, "tmpfs on %s", canon_dir); 175 /* NOTREACHED */ 176 } 177 178 return EXIT_SUCCESS; 179 } 180 181 /* --------------------------------------------------------------------- */ 182 183 static void 184 usage(void) 185 { 186 (void)fprintf(stderr, 187 "Usage: %s [-g group] [-m mode] [-n nodes] [-o options] [-s size]\n" 188 " [-u user] tmpfs mountpoint\n", getprogname()); 189 exit(1); 190 } 191 192 /* --------------------------------------------------------------------- */ 193 194 /* 195 * Obtains a GID number based on the contents of 'str'. If it is a string 196 * and is found in group(5), its corresponding ID is used. Otherwise, an 197 * attempt is made to convert the string to a number and use that as a GID. 198 * In case of success, true is returned and *gid holds the GID value. 199 * Otherwise, false is returned and *gid is untouched. 200 */ 201 static int 202 dehumanize_group(const char *str, gid_t *gid) 203 { 204 int error; 205 struct group *gr; 206 207 gr = getgrnam(str); 208 if (gr != NULL) { 209 *gid = gr->gr_gid; 210 error = 1; 211 } else { 212 char *ep; 213 long tmp; 214 215 errno = 0; 216 tmp = strtol(str, &ep, 10); 217 if (str[0] == '\0' || *ep != '\0') 218 error = 0; /* Not a number. */ 219 else if (errno == ERANGE && 220 (tmp == LONG_MAX || tmp == LONG_MIN)) 221 error = 0; /* Out of range. */ 222 else { 223 *gid = (gid_t)tmp; 224 error = 1; 225 } 226 } 227 228 return error; 229 } 230 231 /* --------------------------------------------------------------------- */ 232 233 /* 234 * Obtains a mode number based on the contents of 'str'. 235 * In case of success, true is returned and *mode holds the mode value. 236 * Otherwise, false is returned and *mode is untouched. 237 */ 238 static int 239 dehumanize_mode(const char *str, mode_t *mode) 240 { 241 char *ep; 242 int error; 243 long tmp; 244 245 errno = 0; 246 tmp = strtol(str, &ep, 8); 247 if (str[0] == '\0' || *ep != '\0') 248 error = 0; /* Not a number. */ 249 else if (errno == ERANGE && 250 (tmp == LONG_MAX || tmp == LONG_MIN)) 251 error = 0; /* Out of range. */ 252 else { 253 *mode = (mode_t)tmp; 254 error = 1; 255 } 256 257 return error; 258 } 259 260 /* --------------------------------------------------------------------- */ 261 262 /* 263 * Converts the number given in 'str', which may be given in a humanized 264 * form (as described in humanize_number(3), but with some limitations), 265 * to a file size (off_t) without units. 266 * In case of success, true is returned and *size holds the value. 267 * Otherwise, false is returned and *size is untouched. 268 */ 269 static int 270 dehumanize_off(const char *str, off_t *size) 271 { 272 char *ep, unit; 273 const char *delimit; 274 size_t len, multiplier, tmp; 275 276 len = strlen(str); 277 if (len < 1) 278 return 0; 279 280 multiplier = 1; 281 282 unit = str[len - 1]; 283 if (isalpha((int)unit)) { 284 switch (unit) { 285 case 'b': 286 multiplier = 1; 287 break; 288 289 case 'k': 290 multiplier = 1024; 291 break; 292 293 case 'M': 294 multiplier = 1024 * 1024; 295 break; 296 297 case 'G': 298 multiplier = 1024 * 1024 * 1024; 299 break; 300 301 default: 302 return 0; /* Invalid suffix. */ 303 } 304 305 delimit = &str[len - 1]; 306 } else 307 delimit = NULL; 308 309 errno = 0; 310 tmp = strtol(str, &ep, 10); 311 if (str[0] == '\0' || (ep != delimit && *ep != '\0')) 312 return 0; /* Not a number. */ 313 else if (errno == ERANGE && 314 (tmp == LONG_MAX || tmp == LONG_MIN)) 315 return 0; /* Out of range. */ 316 317 *size = tmp * multiplier; 318 319 return 1; 320 } 321 322 /* --------------------------------------------------------------------- */ 323 324 /* 325 * Obtains a UID number based on the contents of 'str'. If it is a string 326 * and is found in passwd(5), its corresponding ID is used. Otherwise, an 327 * attempt is made to convert the string to a number and use that as a UID. 328 * In case of success, true is returned and *uid holds the UID value. 329 * Otherwise, false is returned and *uid is untouched. 330 */ 331 static int 332 dehumanize_user(const char *str, uid_t *uid) 333 { 334 int error; 335 struct passwd *pw; 336 337 pw = getpwnam(str); 338 if (pw != NULL) { 339 *uid = pw->pw_uid; 340 error = 1; 341 } else { 342 char *ep; 343 long tmp; 344 345 errno = 0; 346 tmp = strtol(str, &ep, 10); 347 if (str[0] == '\0' || *ep != '\0') 348 error = 0; /* Not a number. */ 349 else if (errno == ERANGE && 350 (tmp == LONG_MAX || tmp == LONG_MIN)) 351 error = 0; /* Out of range. */ 352 else { 353 *uid = (uid_t)tmp; 354 error = 1; 355 } 356 } 357 358 return error; 359 } 360 361 /* --------------------------------------------------------------------- */ 362 363 #ifndef MOUNT_NOMAIN 364 int 365 main(int argc, char *argv[]) 366 { 367 368 return mount_tmpfs(argc, argv); 369 } 370 #endif 371
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