null.c revision 1.34
1 /* $NetBSD: null.c,v 1.34 2019/09/23 12:00:57 christos 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 1.34 2019/09/23 12:00:57 christos 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 puffs_statvfs *svfsb) 195 { 196 struct statvfs sb; 197 if (statvfs(PNPATH(puffs_getroot(pu)), &sb) == -1) 198 return errno; 199 statvfs_to_puffs_statvfs(&sb, svfsb); 200 201 return 0; 202 } 203 204 /* 205 * XXX: this is the stupidest crap ever, but: 206 * getfh() returns the fhandle type, when we are expected to deliver 207 * the fid type. Just adjust it a bit and stop whining. 208 * 209 * Yes, this really really needs fixing. Yes, *REALLY*. 210 */ 211 #define FHANDLE_HEADERLEN 8 212 struct kernfid { 213 unsigned short fid_len; /* length of data in bytes */ 214 unsigned short fid_reserved; /* compat: historic align */ 215 char fid_data[0]; /* data (variable length) */ 216 }; 217 218 /*ARGSUSED*/ 219 static void * 220 fhcmp(struct puffs_usermount *pu, struct puffs_node *pn, void *arg) 221 { 222 struct kernfid *kf1, *kf2; 223 224 if ((kf1 = pn->pn_data) == NULL) 225 return NULL; 226 kf2 = arg; 227 228 if (kf1->fid_len != kf2->fid_len) 229 return NULL; 230 231 /*LINTED*/ 232 if (memcmp(kf1, kf2, kf1->fid_len) == 0) 233 return pn; 234 return NULL; 235 } 236 237 /* 238 * This routine only supports file handles which have been issued while 239 * the server was alive. Not really stable ones, that is. 240 */ 241 /*ARGSUSED*/ 242 int 243 puffs_null_fs_fhtonode(struct puffs_usermount *pu, void *fid, size_t fidsize, 244 struct puffs_newinfo *pni) 245 { 246 struct puffs_node *pn_res; 247 248 pn_res = puffs_pn_nodewalk(pu, fhcmp, fid); 249 if (pn_res == NULL) 250 return ENOENT; 251 252 puffs_newinfo_setcookie(pni, pn_res); 253 puffs_newinfo_setvtype(pni, pn_res->pn_va.va_type); 254 puffs_newinfo_setsize(pni, (voff_t)pn_res->pn_va.va_size); 255 puffs_newinfo_setrdev(pni, pn_res->pn_va.va_rdev); 256 return 0; 257 } 258 259 /*ARGSUSED*/ 260 int 261 puffs_null_fs_nodetofh(struct puffs_usermount *pu, puffs_cookie_t opc, 262 void *fid, size_t *fidsize) 263 { 264 struct puffs_node *pn = opc; 265 struct kernfid *kfid; 266 void *bounce; 267 int rv; 268 269 rv = 0; 270 bounce = NULL; 271 if (*fidsize) { 272 bounce = malloc(*fidsize + FHANDLE_HEADERLEN); 273 if (!bounce) 274 return ENOMEM; 275 *fidsize += FHANDLE_HEADERLEN; 276 } 277 if (getfh(PNPATH(pn), bounce, fidsize) == -1) 278 rv = errno; 279 else 280 memcpy(fid, (uint8_t *)bounce + FHANDLE_HEADERLEN, 281 *fidsize - FHANDLE_HEADERLEN); 282 kfid = fid; 283 if (rv == 0) { 284 *fidsize = kfid->fid_len; 285 pn->pn_data = malloc(*fidsize); 286 if (pn->pn_data == NULL) 287 abort(); /* lazy */ 288 memcpy(pn->pn_data, fid, *fidsize); 289 } else { 290 *fidsize -= FHANDLE_HEADERLEN; 291 } 292 free(bounce); 293 294 return rv; 295 } 296 297 int 298 puffs_null_node_lookup(struct puffs_usermount *pu, puffs_cookie_t opc, 299 struct puffs_newinfo *pni, const struct puffs_cn *pcn) 300 { 301 struct puffs_node *pn = opc, *pn_res; 302 struct stat sb; 303 int rv; 304 305 assert(pn->pn_va.va_type == VDIR); 306 307 /* 308 * Note to whoever is copypasting this: you must first check 309 * if the node is there and only then do nodewalk. Alternatively 310 * you could make sure that you don't return unlinked/rmdir'd 311 * nodes in some other fashion 312 */ 313 rv = lstat(PCNPATH(pcn), &sb); 314 if (rv) 315 return errno; 316 317 /* XXX2: nodewalk is a bit too slow here */ 318 pn_res = puffs_pn_nodewalk(pu, inodecmp, &sb.st_ino); 319 320 if (pn_res == NULL) { 321 pn_res = puffs_pn_new(pu, NULL); 322 if (pn_res == NULL) 323 return ENOMEM; 324 puffs_stat2vattr(&pn_res->pn_va, &sb); 325 } 326 327 puffs_newinfo_setcookie(pni, pn_res); 328 puffs_newinfo_setvtype(pni, pn_res->pn_va.va_type); 329 puffs_newinfo_setsize(pni, (voff_t)pn_res->pn_va.va_size); 330 puffs_newinfo_setrdev(pni, pn_res->pn_va.va_rdev); 331 332 return 0; 333 } 334 335 /*ARGSUSED*/ 336 int 337 puffs_null_node_create(struct puffs_usermount *pu, puffs_cookie_t opc, 338 struct puffs_newinfo *pni, const struct puffs_cn *pcn, 339 const struct vattr *va) 340 { 341 int fd, rv; 342 343 fd = open(PCNPATH(pcn), O_RDWR | O_CREAT | O_TRUNC); 344 if (fd == -1) 345 return errno; 346 close(fd); 347 348 rv = makenode(pu, pni, pcn, va, 1); 349 if (rv) 350 unlink(PCNPATH(pcn)); 351 return rv; 352 } 353 354 /*ARGSUSED*/ 355 int 356 puffs_null_node_mknod(struct puffs_usermount *pu, puffs_cookie_t opc, 357 struct puffs_newinfo *pni, const struct puffs_cn *pcn, 358 const struct vattr *va) 359 { 360 mode_t mode; 361 int rv; 362 363 mode = puffs_addvtype2mode(va->va_mode, va->va_type); 364 if (mknod(PCNPATH(pcn), mode, va->va_rdev) == -1) 365 return errno; 366 367 rv = makenode(pu, pni, pcn, va, 0); 368 if (rv) 369 unlink(PCNPATH(pcn)); 370 return rv; 371 } 372 373 /*ARGSUSED*/ 374 int 375 puffs_null_node_getattr(struct puffs_usermount *pu, puffs_cookie_t opc, 376 struct vattr *va, const struct puffs_cred *pcred) 377 { 378 struct puffs_node *pn = opc; 379 struct stat sb; 380 381 if (lstat(PNPATH(pn), &sb) == -1) 382 return errno; 383 puffs_stat2vattr(va, &sb); 384 385 return 0; 386 } 387 388 /*ARGSUSED*/ 389 int 390 puffs_null_node_setattr(struct puffs_usermount *pu, puffs_cookie_t opc, 391 const struct vattr *va, const struct puffs_cred *pcred) 392 { 393 struct puffs_node *pn = opc; 394 int rv; 395 396 rv = processvattr(PNPATH(pn), va, pn->pn_va.va_type == VREG); 397 if (rv) 398 return rv; 399 400 puffs_setvattr(&pn->pn_va, va); 401 402 return 0; 403 } 404 405 /*ARGSUSED*/ 406 int 407 puffs_null_node_fsync(struct puffs_usermount *pu, puffs_cookie_t opc, 408 const struct puffs_cred *pcred, int how, 409 off_t offlo, off_t offhi) 410 { 411 struct puffs_node *pn = opc; 412 int fd, rv; 413 int fflags; 414 struct stat sb; 415 416 rv = 0; 417 if (stat(PNPATH(pn), &sb) == -1) 418 return errno; 419 if (S_ISDIR(sb.st_mode)) { 420 DIR *dirp; 421 if ((dirp = opendir(PNPATH(pn))) == 0) 422 return errno; 423 fd = dirfd(dirp); 424 if (fd == -1) 425 return errno; 426 427 if (fsync(fd) == -1) 428 rv = errno; 429 } else { 430 fd = writeableopen(PNPATH(pn)); 431 if (fd == -1) 432 return errno; 433 434 if (how & PUFFS_FSYNC_DATAONLY) 435 fflags = FDATASYNC; 436 else 437 fflags = FFILESYNC; 438 if (how & PUFFS_FSYNC_CACHE) 439 fflags |= FDISKSYNC; 440 441 if (fsync_range(fd, fflags, offlo, offhi - offlo) == -1) 442 rv = errno; 443 } 444 445 close(fd); 446 447 return rv; 448 } 449 450 /*ARGSUSED*/ 451 int 452 puffs_null_node_remove(struct puffs_usermount *pu, puffs_cookie_t opc, 453 puffs_cookie_t targ, const struct puffs_cn *pcn) 454 { 455 struct puffs_node *pn_targ = targ; 456 457 if (unlink(PNPATH(pn_targ)) == -1) 458 return errno; 459 puffs_pn_remove(pn_targ); 460 461 return 0; 462 } 463 464 /*ARGSUSED*/ 465 int 466 puffs_null_node_link(struct puffs_usermount *pu, puffs_cookie_t opc, 467 puffs_cookie_t targ, const struct puffs_cn *pcn) 468 { 469 struct puffs_node *pn_targ = targ; 470 471 if (link(PNPATH(pn_targ), PCNPATH(pcn)) == -1) 472 return errno; 473 474 return 0; 475 } 476 477 /*ARGSUSED*/ 478 int 479 puffs_null_node_rename(struct puffs_usermount *pu, puffs_cookie_t opc, 480 puffs_cookie_t src, const struct puffs_cn *pcn_src, 481 puffs_cookie_t targ_dir, puffs_cookie_t targ, 482 const struct puffs_cn *pcn_targ) 483 { 484 struct puffs_node *pn_targ = targ; 485 486 if (rename(PCNPATH(pcn_src), PCNPATH(pcn_targ)) == -1) 487 return errno; 488 489 if (pn_targ) 490 puffs_pn_remove(pn_targ); 491 492 return 0; 493 } 494 495 /*ARGSUSED*/ 496 int 497 puffs_null_node_mkdir(struct puffs_usermount *pu, puffs_cookie_t opc, 498 struct puffs_newinfo *pni, const struct puffs_cn *pcn, 499 const struct vattr *va) 500 { 501 int rv; 502 503 if (mkdir(PCNPATH(pcn), va->va_mode) == -1) 504 return errno; 505 506 rv = makenode(pu, pni, pcn, va, 0); 507 if (rv) 508 rmdir(PCNPATH(pcn)); 509 return rv; 510 } 511 512 /*ARGSUSED*/ 513 int 514 puffs_null_node_rmdir(struct puffs_usermount *pu, puffs_cookie_t opc, 515 puffs_cookie_t targ, const struct puffs_cn *pcn) 516 { 517 struct puffs_node *pn_targ = targ; 518 519 if (rmdir(PNPATH(pn_targ)) == -1) 520 return errno; 521 puffs_pn_remove(pn_targ); 522 523 return 0; 524 } 525 526 /*ARGSUSED*/ 527 int 528 puffs_null_node_symlink(struct puffs_usermount *pu, puffs_cookie_t opc, 529 struct puffs_newinfo *pni, const struct puffs_cn *pcn, 530 const struct vattr *va, const char *linkname) 531 { 532 int rv; 533 534 if (symlink(linkname, PCNPATH(pcn)) == -1) 535 return errno; 536 537 rv = makenode(pu, pni, pcn, va, 0); 538 if (rv) 539 unlink(PCNPATH(pcn)); 540 return rv; 541 } 542 543 /*ARGSUSED*/ 544 int 545 puffs_null_node_readlink(struct puffs_usermount *pu, puffs_cookie_t opc, 546 const struct puffs_cred *pcred, char *linkname, size_t *linklen) 547 { 548 struct puffs_node *pn = opc; 549 ssize_t rv; 550 551 rv = readlink(PNPATH(pn), linkname, *linklen); 552 if (rv == -1) 553 return errno; 554 555 *linklen = rv; 556 return 0; 557 } 558 559 /*ARGSUSED*/ 560 int 561 puffs_null_node_readdir(struct puffs_usermount *pu, puffs_cookie_t opc, 562 struct dirent *de, off_t *off, size_t *reslen, 563 const struct puffs_cred *pcred, int *eofflag, off_t *cookies, 564 size_t *ncookies) 565 { 566 struct puffs_node *pn = opc; 567 struct dirent entry, *result; 568 DIR *dp; 569 off_t i; 570 int rv; 571 572 *ncookies = 0; 573 dp = opendir(PNPATH(pn)); 574 if (dp == NULL) 575 return errno; 576 577 rv = 0; 578 i = *off; 579 580 /* 581 * XXX: need to do trickery here, telldir/seekdir would be nice, but 582 * then we'd need to keep state, which I'm too lazy to keep 583 */ 584 while (i--) { 585 rv = readdir_r(dp, &entry, &result); 586 if (rv != 0) 587 goto out; 588 589 if (!result) { 590 *eofflag = 1; 591 goto out; 592 } 593 } 594 595 for (;;) { 596 rv = readdir_r(dp, &entry, &result); 597 if (rv != 0) 598 goto out; 599 600 if (!result) { 601 *eofflag = 1; 602 goto out; 603 } 604 605 if (_DIRENT_SIZE(result) > *reslen) 606 goto out; 607 608 *de = *result; 609 *reslen -= _DIRENT_SIZE(result); 610 de = _DIRENT_NEXT(de); 611 612 (*off)++; 613 PUFFS_STORE_DCOOKIE(cookies, ncookies, *off); 614 } 615 616 out: 617 closedir(dp); 618 return 0; 619 } 620 621 /*ARGSUSED*/ 622 int 623 puffs_null_node_read(struct puffs_usermount *pu, puffs_cookie_t opc, 624 uint8_t *buf, off_t offset, size_t *buflen, 625 const struct puffs_cred *pcred, int ioflag) 626 { 627 struct puffs_node *pn = opc; 628 ssize_t n; 629 off_t off; 630 int fd, rv; 631 632 rv = 0; 633 fd = open(PNPATH(pn), O_RDONLY); 634 if (fd == -1) 635 return errno; 636 off = lseek(fd, offset, SEEK_SET); 637 if (off == -1) { 638 rv = errno; 639 goto out; 640 } 641 642 n = read(fd, buf, *buflen); 643 if (n == -1) 644 rv = errno; 645 else 646 *buflen -= n; 647 648 out: 649 close(fd); 650 return rv; 651 } 652 653 /*ARGSUSED*/ 654 int 655 puffs_null_node_write(struct puffs_usermount *pu, puffs_cookie_t opc, 656 uint8_t *buf, off_t offset, size_t *buflen, 657 const struct puffs_cred *pcred, int ioflag) 658 { 659 struct puffs_node *pn = opc; 660 ssize_t n; 661 off_t off; 662 int fd, rv; 663 664 rv = 0; 665 fd = writeableopen(PNPATH(pn)); 666 if (fd == -1) 667 return errno; 668 669 off = lseek(fd, offset, SEEK_SET); 670 if (off == -1) { 671 rv = errno; 672 goto out; 673 } 674 675 n = write(fd, buf, *buflen); 676 if (n == -1) 677 rv = errno; 678 else 679 *buflen -= n; 680 681 out: 682 close(fd); 683 return rv; 684 } 685
Indexes created Sun Oct 12 09:09:55 GMT 2025