null.c revision 1.31
1 /* $NetBSD: null.c,v 1.31 2011/11/24 01:55:33 manu 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 1.31 2011/11/24 01:55:33 manu 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/stat.h> 40 #include <sys/time.h> 41 42 #include <assert.h> 43 #include <dirent.h> 44 #include <errno.h> 45 #include <fcntl.h> 46 #include <puffs.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <time.h> 50 #include <unistd.h> 51 52 PUFFSOP_PROTOS(puffs_null) 53 54 /* 55 * set attributes to what is specified. XXX: no rollback in case of failure 56 */ 57 static int 58 processvattr(const char *path, const struct vattr *va, int regular) 59 { 60 struct timeval tv[2]; 61 62 /* XXX: -1 == PUFFS_VNOVAL, but shouldn't trust that */ 63 if (va->va_uid != (unsigned)-1 || va->va_gid != (unsigned)-1) 64 if (lchown(path, va->va_uid, va->va_gid) == -1) 65 return errno; 66 67 if (va->va_mode != (unsigned)PUFFS_VNOVAL) 68 if (lchmod(path, va->va_mode) == -1) 69 return errno; 70 71 /* sloppy */ 72 if (va->va_atime.tv_sec != (time_t)PUFFS_VNOVAL 73 || va->va_mtime.tv_sec != (time_t)PUFFS_VNOVAL) { 74 TIMESPEC_TO_TIMEVAL(&tv[0], &va->va_atime); 75 TIMESPEC_TO_TIMEVAL(&tv[1], &va->va_mtime); 76 77 if (lutimes(path, tv) == -1) 78 return errno; 79 } 80 81 if (regular && va->va_size != (u_quad_t)PUFFS_VNOVAL) 82 if (truncate(path, (off_t)va->va_size) == -1) 83 return errno; 84 85 return 0; 86 } 87 88 /* 89 * Kludge to open files which aren't writable *any longer*. This kinda 90 * works because the vfs layer does validation checks based on the file's 91 * permissions to allow writable opening before opening them. However, 92 * the problem arises if we want to create a file, write to it (cache), 93 * adjust permissions and then flush the file. 94 */ 95 static int 96 writeableopen(const char *path) 97 { 98 struct stat sb; 99 mode_t origmode; 100 int sverr = 0; 101 int fd; 102 103 fd = open(path, O_WRONLY); 104 if (fd == -1) { 105 if (errno == EACCES) { 106 if (stat(path, &sb) == -1) 107 return -1; 108 origmode = sb.st_mode & ALLPERMS; 109 110 if (chmod(path, 0200) == -1) 111 return -1; 112 113 fd = open(path, O_WRONLY); 114 if (fd == -1) 115 sverr = errno; 116 117 chmod(path, origmode); 118 if (sverr) 119 errno = sverr; 120 } else 121 return -1; 122 } 123 124 return fd; 125 } 126 127 /*ARGSUSED*/ 128 static void * 129 inodecmp(struct puffs_usermount *pu, struct puffs_node *pn, void *arg) 130 { 131 ino_t *cmpino = arg; 132 133 if (pn->pn_va.va_fileid == *cmpino) 134 return pn; 135 return NULL; 136 } 137 138 static int 139 makenode(struct puffs_usermount *pu, struct puffs_newinfo *pni, 140 const struct puffs_cn *pcn, const struct vattr *va, int regular) 141 { 142 struct puffs_node *pn; 143 struct stat sb; 144 int rv; 145 146 if ((rv = processvattr(PCNPATH(pcn), va, regular)) != 0) 147 return rv; 148 149 pn = puffs_pn_new(pu, NULL); 150 if (!pn) 151 return ENOMEM; 152 puffs_setvattr(&pn->pn_va, va); 153 154 if (lstat(PCNPATH(pcn), &sb) == -1) 155 return errno; 156 puffs_stat2vattr(&pn->pn_va, &sb); 157 158 puffs_newinfo_setcookie(pni, pn); 159 return 0; 160 } 161 162 /* This should be called first and overriden from the file system */ 163 void 164 puffs_null_setops(struct puffs_ops *pops) 165 { 166 167 PUFFSOP_SET(pops, puffs_null, fs, statvfs); 168 PUFFSOP_SETFSNOP(pops, unmount); 169 PUFFSOP_SETFSNOP(pops, sync); 170 PUFFSOP_SET(pops, puffs_null, fs, fhtonode); 171 PUFFSOP_SET(pops, puffs_null, fs, nodetofh); 172 173 PUFFSOP_SET(pops, puffs_null, node, lookup); 174 PUFFSOP_SET(pops, puffs_null, node, create); 175 PUFFSOP_SET(pops, puffs_null, node, mknod); 176 PUFFSOP_SET(pops, puffs_null, node, getattr); 177 PUFFSOP_SET(pops, puffs_null, node, setattr); 178 PUFFSOP_SET(pops, puffs_null, node, fsync); 179 PUFFSOP_SET(pops, puffs_null, node, remove); 180 PUFFSOP_SET(pops, puffs_null, node, link); 181 PUFFSOP_SET(pops, puffs_null, node, rename); 182 PUFFSOP_SET(pops, puffs_null, node, mkdir); 183 PUFFSOP_SET(pops, puffs_null, node, rmdir); 184 PUFFSOP_SET(pops, puffs_null, node, symlink); 185 PUFFSOP_SET(pops, puffs_null, node, readlink); 186 PUFFSOP_SET(pops, puffs_null, node, readdir); 187 PUFFSOP_SET(pops, puffs_null, node, read); 188 PUFFSOP_SET(pops, puffs_null, node, write); 189 PUFFSOP_SET(pops, puffs_genfs, node, reclaim); 190 } 191 192 /*ARGSUSED*/ 193 int 194 puffs_null_fs_statvfs(struct puffs_usermount *pu, struct statvfs *svfsb) 195 { 196 197 if (statvfs(PNPATH(puffs_getroot(pu)), svfsb) == -1) 198 return errno; 199 200 return 0; 201 } 202 203 /* 204 * XXX: this is the stupidest crap ever, but: 205 * getfh() returns the fhandle type, when we are expected to deliver 206 * the fid type. Just adjust it a bit and stop whining. 207 * 208 * Yes, this really really needs fixing. Yes, *REALLY*. 209 */ 210 #define FHANDLE_HEADERLEN 8 211 struct kernfid { 212 unsigned short fid_len; /* length of data in bytes */ 213 unsigned short fid_reserved; /* compat: historic align */ 214 char fid_data[0]; /* data (variable length) */ 215 }; 216 217 /*ARGSUSED*/ 218 static void * 219 fhcmp(struct puffs_usermount *pu, struct puffs_node *pn, void *arg) 220 { 221 struct kernfid *kf1, *kf2; 222 223 if ((kf1 = pn->pn_data) == NULL) 224 return NULL; 225 kf2 = arg; 226 227 if (kf1->fid_len != kf2->fid_len) 228 return NULL; 229 230 /*LINTED*/ 231 if (memcmp(kf1, kf2, kf1->fid_len) == 0) 232 return pn; 233 return NULL; 234 } 235 236 /* 237 * This routine only supports file handles which have been issued while 238 * the server was alive. Not really stable ones, that is. 239 */ 240 /*ARGSUSED*/ 241 int 242 puffs_null_fs_fhtonode(struct puffs_usermount *pu, void *fid, size_t fidsize, 243 struct puffs_newinfo *pni) 244 { 245 struct puffs_node *pn_res; 246 247 pn_res = puffs_pn_nodewalk(pu, fhcmp, fid); 248 if (pn_res == NULL) 249 return ENOENT; 250 251 puffs_newinfo_setcookie(pni, pn_res); 252 puffs_newinfo_setvtype(pni, pn_res->pn_va.va_type); 253 puffs_newinfo_setsize(pni, (voff_t)pn_res->pn_va.va_size); 254 puffs_newinfo_setrdev(pni, pn_res->pn_va.va_rdev); 255 return 0; 256 } 257 258 /*ARGSUSED*/ 259 int 260 puffs_null_fs_nodetofh(struct puffs_usermount *pu, puffs_cookie_t opc, 261 void *fid, size_t *fidsize) 262 { 263 struct puffs_node *pn = opc; 264 struct kernfid *kfid; 265 void *bounce; 266 int rv; 267 268 rv = 0; 269 bounce = NULL; 270 if (*fidsize) { 271 bounce = malloc(*fidsize + FHANDLE_HEADERLEN); 272 if (!bounce) 273 return ENOMEM; 274 *fidsize += FHANDLE_HEADERLEN; 275 } 276 if (getfh(PNPATH(pn), bounce, fidsize) == -1) 277 rv = errno; 278 else 279 memcpy(fid, (uint8_t *)bounce + FHANDLE_HEADERLEN, 280 *fidsize - FHANDLE_HEADERLEN); 281 kfid = fid; 282 if (rv == 0) { 283 *fidsize = kfid->fid_len; 284 pn->pn_data = malloc(*fidsize); 285 if (pn->pn_data == NULL) 286 abort(); /* lazy */ 287 memcpy(pn->pn_data, fid, *fidsize); 288 } else { 289 *fidsize -= FHANDLE_HEADERLEN; 290 } 291 free(bounce); 292 293 return rv; 294 } 295 296 int 297 puffs_null_node_lookup(struct puffs_usermount *pu, puffs_cookie_t opc, 298 struct puffs_newinfo *pni, const struct puffs_cn *pcn) 299 { 300 struct puffs_node *pn = opc, *pn_res; 301 struct stat sb; 302 int rv; 303 304 assert(pn->pn_va.va_type == VDIR); 305 306 /* 307 * Note to whoever is copypasting this: you must first check 308 * if the node is there and only then do nodewalk. Alternatively 309 * you could make sure that you don't return unlinked/rmdir'd 310 * nodes in some other fashion 311 */ 312 rv = lstat(PCNPATH(pcn), &sb); 313 if (rv) 314 return errno; 315 316 /* XXX2: nodewalk is a bit too slow here */ 317 pn_res = puffs_pn_nodewalk(pu, inodecmp, &sb.st_ino); 318 319 if (pn_res == NULL) { 320 pn_res = puffs_pn_new(pu, NULL); 321 if (pn_res == NULL) 322 return ENOMEM; 323 puffs_stat2vattr(&pn_res->pn_va, &sb); 324 } 325 326 puffs_newinfo_setcookie(pni, pn_res); 327 puffs_newinfo_setvtype(pni, pn_res->pn_va.va_type); 328 puffs_newinfo_setsize(pni, (voff_t)pn_res->pn_va.va_size); 329 puffs_newinfo_setrdev(pni, pn_res->pn_va.va_rdev); 330 331 return 0; 332 } 333 334 /*ARGSUSED*/ 335 int 336 puffs_null_node_create(struct puffs_usermount *pu, puffs_cookie_t opc, 337 struct puffs_newinfo *pni, const struct puffs_cn *pcn, 338 const struct vattr *va) 339 { 340 int fd, rv; 341 342 fd = open(PCNPATH(pcn), O_RDWR | O_CREAT | O_TRUNC); 343 if (fd == -1) 344 return errno; 345 close(fd); 346 347 rv = makenode(pu, pni, pcn, va, 1); 348 if (rv) 349 unlink(PCNPATH(pcn)); 350 return rv; 351 } 352 353 /*ARGSUSED*/ 354 int 355 puffs_null_node_mknod(struct puffs_usermount *pu, puffs_cookie_t opc, 356 struct puffs_newinfo *pni, const struct puffs_cn *pcn, 357 const struct vattr *va) 358 { 359 mode_t mode; 360 int rv; 361 362 mode = puffs_addvtype2mode(va->va_mode, va->va_type); 363 if (mknod(PCNPATH(pcn), mode, va->va_rdev) == -1) 364 return errno; 365 366 rv = makenode(pu, pni, pcn, va, 0); 367 if (rv) 368 unlink(PCNPATH(pcn)); 369 return rv; 370 } 371 372 /*ARGSUSED*/ 373 int 374 puffs_null_node_getattr(struct puffs_usermount *pu, puffs_cookie_t opc, 375 struct vattr *va, const struct puffs_cred *pcred) 376 { 377 struct puffs_node *pn = opc; 378 struct stat sb; 379 380 if (lstat(PNPATH(pn), &sb) == -1) 381 return errno; 382 puffs_stat2vattr(va, &sb); 383 384 return 0; 385 } 386 387 /*ARGSUSED*/ 388 int 389 puffs_null_node_setattr(struct puffs_usermount *pu, puffs_cookie_t opc, 390 const struct vattr *va, const struct puffs_cred *pcred) 391 { 392 struct puffs_node *pn = opc; 393 int rv; 394 395 rv = processvattr(PNPATH(pn), va, pn->pn_va.va_type == VREG); 396 if (rv) 397 return rv; 398 399 puffs_setvattr(&pn->pn_va, va); 400 401 return 0; 402 } 403 404 /*ARGSUSED*/ 405 int 406 puffs_null_node_fsync(struct puffs_usermount *pu, puffs_cookie_t opc, 407 const struct puffs_cred *pcred, int how, 408 off_t offlo, off_t offhi) 409 { 410 struct puffs_node *pn = opc; 411 int fd, rv; 412 int fflags; 413 struct stat sb; 414 415 rv = 0; 416 if (stat(PNPATH(pn), &sb) == -1) 417 return errno; 418 if (S_ISDIR(sb.st_mode)) { 419 DIR *dirp; 420 if ((dirp = opendir(PNPATH(pn))) == 0) 421 return errno; 422 fd = dirfd(dirp); 423 if (fd == -1) 424 return errno; 425 426 if (fsync(fd) == -1) 427 rv = errno; 428 } else { 429 fd = writeableopen(PNPATH(pn)); 430 if (fd == -1) 431 return errno; 432 433 if (how & PUFFS_FSYNC_DATAONLY) 434 fflags = FDATASYNC; 435 else 436 fflags = FFILESYNC; 437 if (how & PUFFS_FSYNC_CACHE) 438 fflags |= FDISKSYNC; 439 440 if (fsync_range(fd, fflags, offlo, offhi - offlo) == -1) 441 rv = errno; 442 } 443 444 close(fd); 445 446 return rv; 447 } 448 449 /*ARGSUSED*/ 450 int 451 puffs_null_node_remove(struct puffs_usermount *pu, puffs_cookie_t opc, 452 puffs_cookie_t targ, const struct puffs_cn *pcn) 453 { 454 struct puffs_node *pn_targ = targ; 455 456 if (unlink(PNPATH(pn_targ)) == -1) 457 return errno; 458 puffs_pn_remove(pn_targ); 459 460 return 0; 461 } 462 463 /*ARGSUSED*/ 464 int 465 puffs_null_node_link(struct puffs_usermount *pu, puffs_cookie_t opc, 466 puffs_cookie_t targ, const struct puffs_cn *pcn) 467 { 468 struct puffs_node *pn_targ = targ; 469 470 if (link(PNPATH(pn_targ), PCNPATH(pcn)) == -1) 471 return errno; 472 473 return 0; 474 } 475 476 /*ARGSUSED*/ 477 int 478 puffs_null_node_rename(struct puffs_usermount *pu, puffs_cookie_t opc, 479 puffs_cookie_t src, const struct puffs_cn *pcn_src, 480 puffs_cookie_t targ_dir, puffs_cookie_t targ, 481 const struct puffs_cn *pcn_targ) 482 { 483 struct puffs_node *pn_targ = targ; 484 485 if (rename(PCNPATH(pcn_src), PCNPATH(pcn_targ)) == -1) 486 return errno; 487 488 if (pn_targ) 489 puffs_pn_remove(pn_targ); 490 491 return 0; 492 } 493 494 /*ARGSUSED*/ 495 int 496 puffs_null_node_mkdir(struct puffs_usermount *pu, puffs_cookie_t opc, 497 struct puffs_newinfo *pni, const struct puffs_cn *pcn, 498 const struct vattr *va) 499 { 500 int rv; 501 502 if (mkdir(PCNPATH(pcn), va->va_mode) == -1) 503 return errno; 504 505 rv = makenode(pu, pni, pcn, va, 0); 506 if (rv) 507 rmdir(PCNPATH(pcn)); 508 return rv; 509 } 510 511 /*ARGSUSED*/ 512 int 513 puffs_null_node_rmdir(struct puffs_usermount *pu, puffs_cookie_t opc, 514 puffs_cookie_t targ, const struct puffs_cn *pcn) 515 { 516 struct puffs_node *pn_targ = targ; 517 518 if (rmdir(PNPATH(pn_targ)) == -1) 519 return errno; 520 puffs_pn_remove(pn_targ); 521 522 return 0; 523 } 524 525 /*ARGSUSED*/ 526 int 527 puffs_null_node_symlink(struct puffs_usermount *pu, puffs_cookie_t opc, 528 struct puffs_newinfo *pni, const struct puffs_cn *pcn, 529 const struct vattr *va, const char *linkname) 530 { 531 int rv; 532 533 if (symlink(linkname, PCNPATH(pcn)) == -1) 534 return errno; 535 536 rv = makenode(pu, pni, pcn, va, 0); 537 if (rv) 538 unlink(PCNPATH(pcn)); 539 return rv; 540 } 541 542 /*ARGSUSED*/ 543 int 544 puffs_null_node_readlink(struct puffs_usermount *pu, puffs_cookie_t opc, 545 const struct puffs_cred *pcred, char *linkname, size_t *linklen) 546 { 547 struct puffs_node *pn = opc; 548 ssize_t rv; 549 550 rv = readlink(PNPATH(pn), linkname, *linklen); 551 if (rv == -1) 552 return errno; 553 554 *linklen = rv; 555 return 0; 556 } 557 558 /*ARGSUSED*/ 559 int 560 puffs_null_node_readdir(struct puffs_usermount *pu, puffs_cookie_t opc, 561 struct dirent *de, off_t *off, size_t *reslen, 562 const struct puffs_cred *pcred, int *eofflag, off_t *cookies, 563 size_t *ncookies) 564 { 565 struct puffs_node *pn = opc; 566 struct dirent entry, *result; 567 DIR *dp; 568 off_t i; 569 int rv; 570 571 *ncookies = 0; 572 dp = opendir(PNPATH(pn)); 573 if (dp == NULL) 574 return errno; 575 576 rv = 0; 577 i = *off; 578 579 /* 580 * XXX: need to do trickery here, telldir/seekdir would be nice, but 581 * then we'd need to keep state, which I'm too lazy to keep 582 */ 583 while (i--) { 584 rv = readdir_r(dp, &entry, &result); 585 if (rv != 0) 586 goto out; 587 588 if (!result) { 589 *eofflag = 1; 590 goto out; 591 } 592 } 593 594 for (;;) { 595 rv = readdir_r(dp, &entry, &result); 596 if (rv != 0) 597 goto out; 598 599 if (!result) { 600 *eofflag = 1; 601 goto out; 602 } 603 604 if (_DIRENT_SIZE(result) > *reslen) 605 goto out; 606 607 *de = *result; 608 *reslen -= _DIRENT_SIZE(result); 609 de = _DIRENT_NEXT(de); 610 611 (*off)++; 612 PUFFS_STORE_DCOOKIE(cookies, ncookies, *off); 613 } 614 615 out: 616 closedir(dp); 617 return 0; 618 } 619 620 /*ARGSUSED*/ 621 int 622 puffs_null_node_read(struct puffs_usermount *pu, puffs_cookie_t opc, 623 uint8_t *buf, off_t offset, size_t *buflen, 624 const struct puffs_cred *pcred, int ioflag) 625 { 626 struct puffs_node *pn = opc; 627 ssize_t n; 628 off_t off; 629 int fd, rv; 630 631 rv = 0; 632 fd = open(PNPATH(pn), O_RDONLY); 633 if (fd == -1) 634 return errno; 635 off = lseek(fd, offset, SEEK_SET); 636 if (off == -1) { 637 rv = errno; 638 goto out; 639 } 640 641 n = read(fd, buf, *buflen); 642 if (n == -1) 643 rv = errno; 644 else 645 *buflen -= n; 646 647 out: 648 close(fd); 649 return rv; 650 } 651 652 /*ARGSUSED*/ 653 int 654 puffs_null_node_write(struct puffs_usermount *pu, puffs_cookie_t opc, 655 uint8_t *buf, off_t offset, size_t *buflen, 656 const struct puffs_cred *pcred, int ioflag) 657 { 658 struct puffs_node *pn = opc; 659 ssize_t n; 660 off_t off; 661 int fd, rv; 662 663 rv = 0; 664 fd = writeableopen(PNPATH(pn)); 665 if (fd == -1) 666 return errno; 667 668 off = lseek(fd, offset, SEEK_SET); 669 if (off == -1) { 670 rv = errno; 671 goto out; 672 } 673 674 n = write(fd, buf, *buflen); 675 if (n == -1) 676 rv = errno; 677 else 678 *buflen -= n; 679 680 out: 681 close(fd); 682 return rv; 683 } 684
Indexes created Tue Sep 23 23:09:58 GMT 2025