null.c revision 1.25
1 /* $NetBSD: null.c,v 1.25 2008/08/12 19:44:39 pooka Exp $ */ 2 3 /* 4 * Copyright (c) 2007 Antti Kantee. All Rights Reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 #if !defined(lint) 30 __RCSID("$NetBSD: null.c,v 1.25 2008/08/12 19:44:39 pooka Exp $"); 31 #endif /* !lint */ 32 33 /* 34 * A "nullfs" using puffs, i.e. maps one location in the hierarchy 35 * to another using standard system calls. 36 */ 37 38 #include <sys/types.h> 39 #include <sys/time.h> 40 41 #include <assert.h> 42 #include <dirent.h> 43 #include <errno.h> 44 #include <fcntl.h> 45 #include <puffs.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <unistd.h> 49 50 PUFFSOP_PROTOS(puffs_null) 51 52 /* 53 * set attributes to what is specified. XXX: no rollback in case of failure 54 */ 55 static int 56 processvattr(const char *path, const struct vattr *va, int regular) 57 { 58 struct timeval tv[2]; 59 60 /* XXX: -1 == PUFFS_VNOVAL, but shouldn't trust that */ 61 if (va->va_uid != (unsigned)-1 || va->va_gid != (unsigned)-1) 62 if (lchown(path, va->va_uid, va->va_gid) == -1) 63 return errno; 64 65 if (va->va_mode != (unsigned)PUFFS_VNOVAL) 66 if (lchmod(path, va->va_mode) == -1) 67 return errno; 68 69 /* sloppy */ 70 if (va->va_atime.tv_sec != (unsigned)PUFFS_VNOVAL 71 || va->va_mtime.tv_sec != (unsigned)PUFFS_VNOVAL) { 72 TIMESPEC_TO_TIMEVAL(&tv[0], &va->va_atime); 73 TIMESPEC_TO_TIMEVAL(&tv[1], &va->va_mtime); 74 75 if (lutimes(path, tv) == -1) 76 return errno; 77 } 78 79 if (regular && va->va_size != (u_quad_t)PUFFS_VNOVAL) 80 if (truncate(path, (off_t)va->va_size) == -1) 81 return errno; 82 83 return 0; 84 } 85 86 /* 87 * Kludge to open files which aren't writable *any longer*. This kinda 88 * works because the vfs layer does validation checks based on the file's 89 * permissions to allow writable opening before opening them. However, 90 * the problem arises if we want to create a file, write to it (cache), 91 * adjust permissions and then flush the file. 92 */ 93 static int 94 writeableopen(const char *path) 95 { 96 struct stat sb; 97 mode_t origmode; 98 int sverr = 0; 99 int fd; 100 101 fd = open(path, O_WRONLY); 102 if (fd == -1) { 103 if (errno == EACCES) { 104 if (stat(path, &sb) == -1) 105 return -1; 106 origmode = sb.st_mode & ALLPERMS; 107 108 if (chmod(path, 0200) == -1) 109 return -1; 110 111 fd = open(path, O_WRONLY); 112 if (fd == -1) 113 sverr = errno; 114 115 chmod(path, origmode); 116 if (sverr) 117 errno = sverr; 118 } else 119 return -1; 120 } 121 122 return fd; 123 } 124 125 /*ARGSUSED*/ 126 static void * 127 inodecmp(struct puffs_usermount *pu, struct puffs_node *pn, void *arg) 128 { 129 ino_t *cmpino = arg; 130 131 if (pn->pn_va.va_fileid == *cmpino) 132 return pn; 133 return NULL; 134 } 135 136 static int 137 makenode(struct puffs_usermount *pu, struct puffs_newinfo *pni, 138 const struct puffs_cn *pcn, const struct vattr *va, int regular) 139 { 140 struct puffs_node *pn; 141 struct stat sb; 142 int rv; 143 144 if ((rv = processvattr(PCNPATH(pcn), va, regular)) != 0) 145 return rv; 146 147 pn = puffs_pn_new(pu, NULL); 148 if (!pn) 149 return ENOMEM; 150 puffs_setvattr(&pn->pn_va, va); 151 152 if (lstat(PCNPATH(pcn), &sb) == -1) 153 return errno; 154 puffs_stat2vattr(&pn->pn_va, &sb); 155 156 puffs_newinfo_setcookie(pni, pn); 157 return 0; 158 } 159 160 /* This should be called first and overriden from the file system */ 161 void 162 puffs_null_setops(struct puffs_ops *pops) 163 { 164 165 PUFFSOP_SET(pops, puffs_null, fs, statvfs); 166 PUFFSOP_SETFSNOP(pops, unmount); 167 PUFFSOP_SETFSNOP(pops, sync); 168 169 PUFFSOP_SET(pops, puffs_null, node, lookup); 170 PUFFSOP_SET(pops, puffs_null, node, create); 171 PUFFSOP_SET(pops, puffs_null, node, mknod); 172 PUFFSOP_SET(pops, puffs_null, node, getattr); 173 PUFFSOP_SET(pops, puffs_null, node, setattr); 174 PUFFSOP_SET(pops, puffs_null, node, fsync); 175 PUFFSOP_SET(pops, puffs_null, node, remove); 176 PUFFSOP_SET(pops, puffs_null, node, link); 177 PUFFSOP_SET(pops, puffs_null, node, rename); 178 PUFFSOP_SET(pops, puffs_null, node, mkdir); 179 PUFFSOP_SET(pops, puffs_null, node, rmdir); 180 PUFFSOP_SET(pops, puffs_null, node, symlink); 181 PUFFSOP_SET(pops, puffs_null, node, readlink); 182 PUFFSOP_SET(pops, puffs_null, node, readdir); 183 PUFFSOP_SET(pops, puffs_null, node, read); 184 PUFFSOP_SET(pops, puffs_null, node, write); 185 PUFFSOP_SET(pops, puffs_genfs, node, reclaim); 186 } 187 188 /*ARGSUSED*/ 189 int 190 puffs_null_fs_statvfs(struct puffs_usermount *pu, struct statvfs *svfsb) 191 { 192 193 if (statvfs(PNPATH(puffs_getroot(pu)), svfsb) == -1) 194 return errno; 195 196 return 0; 197 } 198 199 int 200 puffs_null_node_lookup(struct puffs_usermount *pu, puffs_cookie_t opc, 201 struct puffs_newinfo *pni, const struct puffs_cn *pcn) 202 { 203 struct puffs_node *pn = opc, *pn_res; 204 struct stat sb; 205 int rv; 206 207 assert(pn->pn_va.va_type == VDIR); 208 209 /* 210 * Note to whoever is copypasting this: you must first check 211 * if the node is there and only then do nodewalk. Alternatively 212 * you could make sure that you don't return unlinked/rmdir'd 213 * nodes in some other fashion 214 */ 215 rv = lstat(PCNPATH(pcn), &sb); 216 if (rv) 217 return errno; 218 219 /* XXX2: nodewalk is a bit too slow here */ 220 pn_res = puffs_pn_nodewalk(pu, inodecmp, &sb.st_ino); 221 222 if (pn_res == NULL) { 223 pn_res = puffs_pn_new(pu, NULL); 224 if (pn_res == NULL) 225 return ENOMEM; 226 puffs_stat2vattr(&pn_res->pn_va, &sb); 227 } 228 229 puffs_newinfo_setcookie(pni, pn_res); 230 puffs_newinfo_setvtype(pni, pn_res->pn_va.va_type); 231 puffs_newinfo_setsize(pni, (voff_t)pn_res->pn_va.va_size); 232 puffs_newinfo_setrdev(pni, pn_res->pn_va.va_rdev); 233 234 return 0; 235 } 236 237 /*ARGSUSED*/ 238 int 239 puffs_null_node_create(struct puffs_usermount *pu, puffs_cookie_t opc, 240 struct puffs_newinfo *pni, const struct puffs_cn *pcn, 241 const struct vattr *va) 242 { 243 int fd, rv; 244 245 fd = open(PCNPATH(pcn), O_RDWR | O_CREAT | O_TRUNC); 246 if (fd == -1) 247 return errno; 248 close(fd); 249 250 rv = makenode(pu, pni, pcn, va, 1); 251 if (rv) 252 unlink(PCNPATH(pcn)); 253 return rv; 254 } 255 256 /*ARGSUSED*/ 257 int 258 puffs_null_node_mknod(struct puffs_usermount *pu, puffs_cookie_t opc, 259 struct puffs_newinfo *pni, const struct puffs_cn *pcn, 260 const struct vattr *va) 261 { 262 mode_t mode; 263 int rv; 264 265 mode = puffs_addvtype2mode(va->va_mode, va->va_type); 266 if (mknod(PCNPATH(pcn), mode, va->va_rdev) == -1) 267 return errno; 268 269 rv = makenode(pu, pni, pcn, va, 0); 270 if (rv) 271 unlink(PCNPATH(pcn)); 272 return rv; 273 } 274 275 /*ARGSUSED*/ 276 int 277 puffs_null_node_getattr(struct puffs_usermount *pu, puffs_cookie_t opc, 278 struct vattr *va, const struct puffs_cred *pcred) 279 { 280 struct puffs_node *pn = opc; 281 struct stat sb; 282 283 if (lstat(PNPATH(pn), &sb) == -1) 284 return errno; 285 puffs_stat2vattr(va, &sb); 286 287 return 0; 288 } 289 290 /*ARGSUSED*/ 291 int 292 puffs_null_node_setattr(struct puffs_usermount *pu, puffs_cookie_t opc, 293 const struct vattr *va, const struct puffs_cred *pcred) 294 { 295 struct puffs_node *pn = opc; 296 int rv; 297 298 rv = processvattr(PNPATH(pn), va, pn->pn_va.va_type == VREG); 299 if (rv) 300 return rv; 301 302 puffs_setvattr(&pn->pn_va, va); 303 304 return 0; 305 } 306 307 /*ARGSUSED*/ 308 int 309 puffs_null_node_fsync(struct puffs_usermount *pu, puffs_cookie_t opc, 310 const struct puffs_cred *pcred, int how, 311 off_t offlo, off_t offhi) 312 { 313 struct puffs_node *pn = opc; 314 int fd, rv; 315 int fflags; 316 317 rv = 0; 318 fd = writeableopen(PNPATH(pn)); 319 if (fd == -1) 320 return errno; 321 322 if (how & PUFFS_FSYNC_DATAONLY) 323 fflags = FDATASYNC; 324 else 325 fflags = FFILESYNC; 326 if (how & PUFFS_FSYNC_CACHE) 327 fflags |= FDISKSYNC; 328 329 if (fsync_range(fd, fflags, offlo, offhi - offlo) == -1) 330 rv = errno; 331 332 close(fd); 333 334 return rv; 335 } 336 337 /*ARGSUSED*/ 338 int 339 puffs_null_node_remove(struct puffs_usermount *pu, puffs_cookie_t opc, 340 puffs_cookie_t targ, const struct puffs_cn *pcn) 341 { 342 struct puffs_node *pn_targ = targ; 343 344 if (unlink(PNPATH(pn_targ)) == -1) 345 return errno; 346 puffs_pn_remove(pn_targ); 347 348 return 0; 349 } 350 351 /*ARGSUSED*/ 352 int 353 puffs_null_node_link(struct puffs_usermount *pu, puffs_cookie_t opc, 354 puffs_cookie_t targ, const struct puffs_cn *pcn) 355 { 356 struct puffs_node *pn_targ = targ; 357 358 if (link(PNPATH(pn_targ), PCNPATH(pcn)) == -1) 359 return errno; 360 361 return 0; 362 } 363 364 /*ARGSUSED*/ 365 int 366 puffs_null_node_rename(struct puffs_usermount *pu, puffs_cookie_t opc, 367 puffs_cookie_t src, const struct puffs_cn *pcn_src, 368 puffs_cookie_t targ_dir, puffs_cookie_t targ, 369 const struct puffs_cn *pcn_targ) 370 { 371 372 if (rename(PCNPATH(pcn_src), PCNPATH(pcn_targ)) == -1) 373 return errno; 374 375 return 0; 376 } 377 378 /*ARGSUSED*/ 379 int 380 puffs_null_node_mkdir(struct puffs_usermount *pu, puffs_cookie_t opc, 381 struct puffs_newinfo *pni, const struct puffs_cn *pcn, 382 const struct vattr *va) 383 { 384 int rv; 385 386 if (mkdir(PCNPATH(pcn), va->va_mode) == -1) 387 return errno; 388 389 rv = makenode(pu, pni, pcn, va, 0); 390 if (rv) 391 rmdir(PCNPATH(pcn)); 392 return rv; 393 } 394 395 /*ARGSUSED*/ 396 int 397 puffs_null_node_rmdir(struct puffs_usermount *pu, puffs_cookie_t opc, 398 puffs_cookie_t targ, const struct puffs_cn *pcn) 399 { 400 struct puffs_node *pn_targ = targ; 401 402 if (rmdir(PNPATH(pn_targ)) == -1) 403 return errno; 404 puffs_pn_remove(pn_targ); 405 406 return 0; 407 } 408 409 /*ARGSUSED*/ 410 int 411 puffs_null_node_symlink(struct puffs_usermount *pu, puffs_cookie_t opc, 412 struct puffs_newinfo *pni, const struct puffs_cn *pcn, 413 const struct vattr *va, const char *linkname) 414 { 415 int rv; 416 417 if (symlink(linkname, PCNPATH(pcn)) == -1) 418 return errno; 419 420 rv = makenode(pu, pni, pcn, va, 0); 421 if (rv) 422 unlink(PCNPATH(pcn)); 423 return rv; 424 } 425 426 /*ARGSUSED*/ 427 int 428 puffs_null_node_readlink(struct puffs_usermount *pu, puffs_cookie_t opc, 429 const struct puffs_cred *pcred, char *linkname, size_t *linklen) 430 { 431 struct puffs_node *pn = opc; 432 ssize_t rv; 433 434 rv = readlink(PNPATH(pn), linkname, *linklen); 435 if (rv == -1) 436 return errno; 437 438 *linklen = rv; 439 return 0; 440 } 441 442 /*ARGSUSED*/ 443 int 444 puffs_null_node_readdir(struct puffs_usermount *pu, puffs_cookie_t opc, 445 struct dirent *de, off_t *off, size_t *reslen, 446 const struct puffs_cred *pcred, int *eofflag, off_t *cookies, 447 size_t *ncookies) 448 { 449 struct puffs_node *pn = opc; 450 struct dirent entry, *result; 451 DIR *dp; 452 off_t i; 453 int rv; 454 455 dp = opendir(PNPATH(pn)); 456 if (dp == NULL) 457 return errno; 458 459 rv = 0; 460 i = *off; 461 462 /* 463 * XXX: need to do trickery here, telldir/seekdir would be nice, but 464 * then we'd need to keep state, which I'm too lazy to keep 465 */ 466 while (i--) { 467 rv = readdir_r(dp, &entry, &result); 468 if (rv || !result) 469 goto out; 470 } 471 472 for (;;) { 473 rv = readdir_r(dp, &entry, &result); 474 if (rv != 0) 475 goto out; 476 477 if (!result) 478 goto out; 479 480 if (_DIRENT_SIZE(result) > *reslen) 481 goto out; 482 483 *de = *result; 484 *reslen -= _DIRENT_SIZE(result); 485 de = _DIRENT_NEXT(de); 486 487 (*off)++; 488 } 489 490 out: 491 closedir(dp); 492 return 0; 493 } 494 495 /*ARGSUSED*/ 496 int 497 puffs_null_node_read(struct puffs_usermount *pu, puffs_cookie_t opc, 498 uint8_t *buf, off_t offset, size_t *buflen, 499 const struct puffs_cred *pcred, int ioflag) 500 { 501 struct puffs_node *pn = opc; 502 ssize_t n; 503 off_t off; 504 int fd, rv; 505 506 rv = 0; 507 fd = open(PNPATH(pn), O_RDONLY); 508 if (fd == -1) 509 return errno; 510 off = lseek(fd, offset, SEEK_SET); 511 if (off == -1) { 512 rv = errno; 513 goto out; 514 } 515 516 n = read(fd, buf, *buflen); 517 if (n == -1) 518 rv = errno; 519 else 520 *buflen -= n; 521 522 out: 523 close(fd); 524 return rv; 525 } 526 527 /*ARGSUSED*/ 528 int 529 puffs_null_node_write(struct puffs_usermount *pu, puffs_cookie_t opc, 530 uint8_t *buf, off_t offset, size_t *buflen, 531 const struct puffs_cred *pcred, int ioflag) 532 { 533 struct puffs_node *pn = opc; 534 ssize_t n; 535 off_t off; 536 int fd, rv; 537 538 rv = 0; 539 fd = writeableopen(PNPATH(pn)); 540 if (fd == -1) 541 return errno; 542 543 off = lseek(fd, offset, SEEK_SET); 544 if (off == -1) { 545 rv = errno; 546 goto out; 547 } 548 549 n = write(fd, buf, *buflen); 550 if (n == -1) 551 rv = errno; 552 else 553 *buflen -= n; 554 555 out: 556 close(fd); 557 return rv; 558 } 559
Indexes created Thu Sep 25 16:09:42 GMT 2025