null.c revision 1.19
1 /* $NetBSD: null.c,v 1.19 2007/06/25 07:52:01 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 1.19 2007/06/25 07:52:01 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, void **newnode, 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 *newnode = 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_null, node, reclaim); 186 } 187 188 /*ARGSUSED*/ 189 int 190 puffs_null_fs_statvfs(struct puffs_cc *pcc, struct statvfs *svfsb, pid_t pid) 191 { 192 struct puffs_usermount *pu = puffs_cc_getusermount(pcc); 193 194 if (statvfs(PNPATH(puffs_getroot(pu)), svfsb) == -1) 195 return errno; 196 197 return 0; 198 } 199 200 int 201 puffs_null_node_lookup(struct puffs_cc *pcc, void *opc, void **newnode, 202 enum vtype *newtype, voff_t *newsize, dev_t *newrdev, 203 const struct puffs_cn *pcn) 204 { 205 struct puffs_usermount *pu = puffs_cc_getusermount(pcc); 206 struct puffs_node *pn = opc, *pn_res; 207 struct stat sb; 208 int rv; 209 210 assert(pn->pn_va.va_type == VDIR); 211 212 /* 213 * Note to whoever is copypasting this: you must first check 214 * if the node is there and only then do nodewalk. Alternatively 215 * you could make sure that you don't return unlinked/rmdir'd 216 * nodes in some other fashion 217 */ 218 rv = lstat(PCNPATH(pcn), &sb); 219 if (rv) 220 return errno; 221 222 /* XXX2: nodewalk is a bit too slow here */ 223 pn_res = puffs_pn_nodewalk(pu, inodecmp, &sb.st_ino); 224 225 if (pn_res == NULL) { 226 pn_res = puffs_pn_new(pu, NULL); 227 if (pn_res == NULL) 228 return ENOMEM; 229 puffs_stat2vattr(&pn_res->pn_va, &sb); 230 } 231 232 *newnode = pn_res; 233 *newtype = pn_res->pn_va.va_type; 234 *newsize = pn_res->pn_va.va_size; 235 *newrdev = pn_res->pn_va.va_rdev; 236 237 return 0; 238 } 239 240 /*ARGSUSED*/ 241 int 242 puffs_null_node_create(struct puffs_cc *pcc, void *opc, void **newnode, 243 const struct puffs_cn *pcn, const struct vattr *va) 244 { 245 struct puffs_usermount *pu = puffs_cc_getusermount(pcc); 246 int fd, rv; 247 248 fd = open(PCNPATH(pcn), O_RDWR | O_CREAT | O_TRUNC); 249 if (fd == -1) 250 return errno; 251 close(fd); 252 253 rv = makenode(pu, newnode, pcn, va, 1); 254 if (rv) 255 unlink(PCNPATH(pcn)); 256 return rv; 257 } 258 259 /*ARGSUSED*/ 260 int 261 puffs_null_node_mknod(struct puffs_cc *pcc, void *opc, void **newnode, 262 const struct puffs_cn *pcn, const struct vattr *va) 263 { 264 struct puffs_usermount *pu = puffs_cc_getusermount(pcc); 265 mode_t mode; 266 int rv; 267 268 mode = puffs_addvtype2mode(va->va_mode, va->va_type); 269 if (mknod(PCNPATH(pcn), mode, va->va_rdev) == -1) 270 return errno; 271 272 rv = makenode(pu, newnode, pcn, va, 0); 273 if (rv) 274 unlink(PCNPATH(pcn)); 275 return rv; 276 } 277 278 /*ARGSUSED*/ 279 int 280 puffs_null_node_getattr(struct puffs_cc *pcc, void *opc, struct vattr *va, 281 const struct puffs_cred *pcred, pid_t pid) 282 { 283 struct puffs_node *pn = opc; 284 struct stat sb; 285 286 if (lstat(PNPATH(pn), &sb) == -1) 287 return errno; 288 puffs_stat2vattr(va, &sb); 289 290 return 0; 291 } 292 293 /*ARGSUSED*/ 294 int 295 puffs_null_node_setattr(struct puffs_cc *pcc, void *opc, 296 const struct vattr *va, const struct puffs_cred *pcred, pid_t pid) 297 { 298 struct puffs_node *pn = opc; 299 int rv; 300 301 rv = processvattr(PNPATH(pn), va, pn->pn_va.va_type == VREG); 302 if (rv) 303 return rv; 304 305 puffs_setvattr(&pn->pn_va, va); 306 307 return 0; 308 } 309 310 /*ARGSUSED*/ 311 int 312 puffs_null_node_fsync(struct puffs_cc *pcc, void *opc, 313 const struct puffs_cred *pcred, int how, 314 off_t offlo, off_t offhi, pid_t pid) 315 { 316 struct puffs_node *pn = opc; 317 int fd, rv; 318 int fflags; 319 320 rv = 0; 321 fd = writeableopen(PNPATH(pn)); 322 if (fd == -1) 323 return errno; 324 325 if (how & PUFFS_FSYNC_DATAONLY) 326 fflags = FDATASYNC; 327 else 328 fflags = FFILESYNC; 329 if (how & PUFFS_FSYNC_CACHE) 330 fflags |= FDISKSYNC; 331 332 if (fsync_range(fd, fflags, offlo, offhi - offlo) == -1) 333 rv = errno; 334 335 close(fd); 336 337 return rv; 338 } 339 340 /*ARGSUSED*/ 341 int 342 puffs_null_node_remove(struct puffs_cc *pcc, void *opc, void *targ, 343 const struct puffs_cn *pcn) 344 { 345 struct puffs_node *pn_targ = targ; 346 347 if (unlink(PNPATH(pn_targ)) == -1) 348 return errno; 349 puffs_pn_remove(pn_targ); 350 351 return 0; 352 } 353 354 /*ARGSUSED*/ 355 int 356 puffs_null_node_link(struct puffs_cc *pcc, void *opc, void *targ, 357 const struct puffs_cn *pcn) 358 { 359 struct puffs_node *pn_targ = targ; 360 361 if (link(PNPATH(pn_targ), PCNPATH(pcn)) == -1) 362 return errno; 363 364 return 0; 365 } 366 367 /*ARGSUSED*/ 368 int 369 puffs_null_node_rename(struct puffs_cc *pcc, void *opc, void *src, 370 const struct puffs_cn *pcn_src, void *targ_dir, void *targ, 371 const struct puffs_cn *pcn_targ) 372 { 373 374 if (rename(PCNPATH(pcn_src), PCNPATH(pcn_targ)) == -1) 375 return errno; 376 377 return 0; 378 } 379 380 /*ARGSUSED*/ 381 int 382 puffs_null_node_mkdir(struct puffs_cc *pcc, void *opc, void **newnode, 383 const struct puffs_cn *pcn, const struct vattr *va) 384 { 385 struct puffs_usermount *pu = puffs_cc_getusermount(pcc); 386 int rv; 387 388 if (mkdir(PCNPATH(pcn), va->va_mode) == -1) 389 return errno; 390 391 rv = makenode(pu, newnode, pcn, va, 0); 392 if (rv) 393 rmdir(PCNPATH(pcn)); 394 return rv; 395 } 396 397 /*ARGSUSED*/ 398 int 399 puffs_null_node_rmdir(struct puffs_cc *pcc, void *opc, void *targ, 400 const struct puffs_cn *pcn) 401 { 402 struct puffs_node *pn_targ = targ; 403 404 if (rmdir(PNPATH(pn_targ)) == -1) 405 return errno; 406 puffs_pn_remove(pn_targ); 407 408 return 0; 409 } 410 411 /*ARGSUSED*/ 412 int 413 puffs_null_node_symlink(struct puffs_cc *pcc, void *opc, void **newnode, 414 const struct puffs_cn *pcn, const struct vattr *va, 415 const char *linkname) 416 { 417 struct puffs_usermount *pu = puffs_cc_getusermount(pcc); 418 int rv; 419 420 if (symlink(linkname, PCNPATH(pcn)) == -1) 421 return errno; 422 423 rv = makenode(pu, newnode, pcn, va, 0); 424 if (rv) 425 unlink(PCNPATH(pcn)); 426 return rv; 427 } 428 429 /*ARGSUSED*/ 430 int 431 puffs_null_node_readlink(struct puffs_cc *pcc, void *opc, 432 const struct puffs_cred *pcred, char *linkname, size_t *linklen) 433 { 434 struct puffs_node *pn = opc; 435 ssize_t rv; 436 437 rv = readlink(PNPATH(pn), linkname, *linklen); 438 if (rv == -1) 439 return errno; 440 441 *linklen = rv; 442 return 0; 443 } 444 445 /*ARGSUSED*/ 446 int 447 puffs_null_node_readdir(struct puffs_cc *pcc, void *opc, struct dirent *de, 448 off_t *off, size_t *reslen, const struct puffs_cred *pcred, 449 int *eofflag, off_t *cookies, size_t *ncookies) 450 { 451 struct puffs_node *pn = opc; 452 struct dirent entry, *result; 453 DIR *dp; 454 off_t i; 455 int rv; 456 457 dp = opendir(PNPATH(pn)); 458 if (dp == NULL) 459 return errno; 460 461 rv = 0; 462 i = *off; 463 464 /* 465 * XXX: need to do trickery here, telldir/seekdir would be nice, but 466 * then we'd need to keep state, which I'm too lazy to keep 467 */ 468 while (i--) { 469 rv = readdir_r(dp, &entry, &result); 470 if (rv || !result) 471 goto out; 472 } 473 474 for (;;) { 475 rv = readdir_r(dp, &entry, &result); 476 if (rv != 0) 477 goto out; 478 479 if (!result) 480 goto out; 481 482 if (_DIRENT_SIZE(result) > *reslen) 483 goto out; 484 485 *de = *result; 486 *reslen -= _DIRENT_SIZE(result); 487 de = _DIRENT_NEXT(de); 488 489 (*off)++; 490 } 491 492 out: 493 closedir(dp); 494 return 0; 495 } 496 497 /*ARGSUSED*/ 498 int 499 puffs_null_node_read(struct puffs_cc *pcc, void *opc, uint8_t *buf, 500 off_t offset, size_t *buflen, const struct puffs_cred *pcred, 501 int ioflag) 502 { 503 struct puffs_node *pn = opc; 504 ssize_t n; 505 off_t off; 506 int fd, rv; 507 508 rv = 0; 509 fd = open(PNPATH(pn), O_RDONLY); 510 if (fd == -1) 511 return errno; 512 off = lseek(fd, offset, SEEK_SET); 513 if (off == -1) { 514 rv = errno; 515 goto out; 516 } 517 518 n = read(fd, buf, *buflen); 519 if (n == -1) 520 rv = errno; 521 else 522 *buflen -= n; 523 524 out: 525 close(fd); 526 return rv; 527 } 528 529 /*ARGSUSED*/ 530 int 531 puffs_null_node_write(struct puffs_cc *pcc, void *opc, uint8_t *buf, 532 off_t offset, size_t *buflen, const struct puffs_cred *pcred, 533 int ioflag) 534 { 535 struct puffs_node *pn = opc; 536 ssize_t n; 537 off_t off; 538 int fd, rv; 539 540 rv = 0; 541 fd = writeableopen(PNPATH(pn)); 542 if (fd == -1) 543 return errno; 544 545 off = lseek(fd, offset, SEEK_SET); 546 if (off == -1) { 547 rv = errno; 548 goto out; 549 } 550 551 n = write(fd, buf, *buflen); 552 if (n == -1) 553 rv = errno; 554 else 555 *buflen -= n; 556 557 out: 558 close(fd); 559 return rv; 560 } 561 562 /*ARGSUSED*/ 563 int 564 puffs_null_node_reclaim(struct puffs_cc *pcc, void *opc, pid_t pid) 565 { 566 567 return puffs_genfs_node_reclaim(pcc, opc, pid); 568 } 569
Indexes created Fri Sep 26 20:09:58 GMT 2025