| 1 | /* lfs_vnops.c 4.27 82/06/25 */ |
| 2 | |
| 3 | #include "../h/param.h" |
| 4 | #include "../h/systm.h" |
| 5 | #include "../h/dir.h" |
| 6 | #include "../h/user.h" |
| 7 | #include "../h/file.h" |
| 8 | #include "../h/stat.h" |
| 9 | #include "../h/inode.h" |
| 10 | #include "../h/fs.h" |
| 11 | #include "../h/buf.h" |
| 12 | #include "../h/proc.h" |
| 13 | #include "../h/inline.h" |
| 14 | |
| 15 | chdir() |
| 16 | { |
| 17 | |
| 18 | chdirec(&u.u_cdir); |
| 19 | } |
| 20 | |
| 21 | chroot() |
| 22 | { |
| 23 | |
| 24 | if (suser()) |
| 25 | chdirec(&u.u_rdir); |
| 26 | } |
| 27 | |
| 28 | chdirec(ipp) |
| 29 | register struct inode **ipp; |
| 30 | { |
| 31 | register struct inode *ip; |
| 32 | struct a { |
| 33 | char *fname; |
| 34 | }; |
| 35 | |
| 36 | ip = namei(uchar, 0, 1); |
| 37 | if(ip == NULL) |
| 38 | return; |
| 39 | if((ip->i_mode&IFMT) != IFDIR) { |
| 40 | u.u_error = ENOTDIR; |
| 41 | goto bad; |
| 42 | } |
| 43 | if(access(ip, IEXEC)) |
| 44 | goto bad; |
| 45 | iunlock(ip); |
| 46 | if (*ipp) |
| 47 | irele(*ipp); |
| 48 | *ipp = ip; |
| 49 | return; |
| 50 | |
| 51 | bad: |
| 52 | iput(ip); |
| 53 | } |
| 54 | |
| 55 | /* |
| 56 | * Open system call. |
| 57 | */ |
| 58 | open() |
| 59 | { |
| 60 | register struct inode *ip; |
| 61 | register struct a { |
| 62 | char *fname; |
| 63 | int rwmode; |
| 64 | } *uap; |
| 65 | |
| 66 | uap = (struct a *)u.u_ap; |
| 67 | ip = namei(uchar, 0, 1); |
| 68 | if (ip == NULL) |
| 69 | return; |
| 70 | open1(ip, ++uap->rwmode, 0); |
| 71 | } |
| 72 | |
| 73 | /* |
| 74 | * Creat system call. |
| 75 | */ |
| 76 | creat() |
| 77 | { |
| 78 | register struct inode *ip; |
| 79 | register struct a { |
| 80 | char *fname; |
| 81 | int fmode; |
| 82 | } *uap; |
| 83 | |
| 84 | uap = (struct a *)u.u_ap; |
| 85 | ip = namei(uchar, 1, 1); |
| 86 | if (ip == NULL) { |
| 87 | if (u.u_error) |
| 88 | return; |
| 89 | ip = maknode(uap->fmode&07777&(~ISVTX)); |
| 90 | if (ip==NULL) |
| 91 | return; |
| 92 | open1(ip, FWRITE, 2); |
| 93 | } else |
| 94 | open1(ip, FWRITE, 1); |
| 95 | } |
| 96 | |
| 97 | /* |
| 98 | * Common code for open and creat. |
| 99 | * Check permissions, allocate an open file structure, |
| 100 | * and call the device open routine if any. |
| 101 | */ |
| 102 | open1(ip, mode, trf) |
| 103 | register struct inode *ip; |
| 104 | register mode; |
| 105 | { |
| 106 | register struct file *fp; |
| 107 | int i; |
| 108 | |
| 109 | if (trf != 2) { |
| 110 | if (mode&FREAD) |
| 111 | (void) access(ip, IREAD); |
| 112 | if (mode&FWRITE) { |
| 113 | (void) access(ip, IWRITE); |
| 114 | if ((ip->i_mode&IFMT) == IFDIR) |
| 115 | u.u_error = EISDIR; |
| 116 | } |
| 117 | } |
| 118 | if (u.u_error) { |
| 119 | iput(ip); |
| 120 | return; |
| 121 | } |
| 122 | if (trf == 1) |
| 123 | itrunc(ip); |
| 124 | iunlock(ip); |
| 125 | if ((fp = falloc()) == NULL) |
| 126 | goto out; |
| 127 | fp->f_flag = mode&(FREAD|FWRITE); |
| 128 | i = u.u_r.r_val1; |
| 129 | fp->f_inode = ip; |
| 130 | openi(ip, mode&(FREAD|FWRITE)); |
| 131 | if (u.u_error == 0) |
| 132 | return; |
| 133 | u.u_ofile[i] = NULL; |
| 134 | fp->f_count--; |
| 135 | out: |
| 136 | irele(ip); |
| 137 | } |
| 138 | |
| 139 | /* |
| 140 | * Mknod system call |
| 141 | */ |
| 142 | mknod() |
| 143 | { |
| 144 | register struct inode *ip; |
| 145 | register struct a { |
| 146 | char *fname; |
| 147 | int fmode; |
| 148 | int dev; |
| 149 | } *uap; |
| 150 | |
| 151 | uap = (struct a *)u.u_ap; |
| 152 | if (suser()) { |
| 153 | ip = namei(uchar, 1, 0); |
| 154 | if (ip != NULL) { |
| 155 | u.u_error = EEXIST; |
| 156 | goto out; |
| 157 | } |
| 158 | } |
| 159 | if (u.u_error) |
| 160 | return; |
| 161 | ip = maknode(uap->fmode); |
| 162 | if (ip == NULL) |
| 163 | return; |
| 164 | if (uap->dev) { |
| 165 | /* |
| 166 | * Want to be able to use this to make badblock |
| 167 | * inodes, so don't truncate the dev number. |
| 168 | */ |
| 169 | ip->i_rdev = uap->dev; |
| 170 | ip->i_flag |= IACC|IUPD|ICHG; |
| 171 | } |
| 172 | |
| 173 | out: |
| 174 | iput(ip); |
| 175 | } |
| 176 | |
| 177 | /* |
| 178 | * link system call |
| 179 | */ |
| 180 | link() |
| 181 | { |
| 182 | register struct inode *ip, *xp; |
| 183 | register struct a { |
| 184 | char *target; |
| 185 | char *linkname; |
| 186 | } *uap; |
| 187 | |
| 188 | uap = (struct a *)u.u_ap; |
| 189 | ip = namei(uchar, 0, 1); /* well, this routine is doomed anyhow */ |
| 190 | if (ip == NULL) |
| 191 | return; |
| 192 | if ((ip->i_mode&IFMT)==IFDIR && !suser()) |
| 193 | goto out1; |
| 194 | ip->i_nlink++; |
| 195 | ip->i_flag |= ICHG; |
| 196 | iupdat(ip, &time, &time, 1); |
| 197 | iunlock(ip); |
| 198 | u.u_dirp = (caddr_t)uap->linkname; |
| 199 | xp = namei(uchar, 1, 0); |
| 200 | if (xp != NULL) { |
| 201 | u.u_error = EEXIST; |
| 202 | iput(xp); |
| 203 | goto out; |
| 204 | } |
| 205 | if (u.u_error) |
| 206 | goto out; |
| 207 | if (u.u_pdir->i_dev != ip->i_dev) { |
| 208 | iput(u.u_pdir); |
| 209 | u.u_error = EXDEV; |
| 210 | goto out; |
| 211 | } |
| 212 | wdir(ip); |
| 213 | out: |
| 214 | if (u.u_error) { |
| 215 | ip->i_nlink--; |
| 216 | ip->i_flag |= ICHG; |
| 217 | } |
| 218 | out1: |
| 219 | irele(ip); |
| 220 | } |
| 221 | |
| 222 | /* |
| 223 | * symlink -- make a symbolic link |
| 224 | */ |
| 225 | symlink() |
| 226 | { |
| 227 | register struct a { |
| 228 | char *target; |
| 229 | char *linkname; |
| 230 | } *uap; |
| 231 | register struct inode *ip; |
| 232 | register char *tp; |
| 233 | register c, nc; |
| 234 | |
| 235 | uap = (struct a *)u.u_ap; |
| 236 | tp = uap->target; |
| 237 | nc = 0; |
| 238 | while (c = fubyte(tp)) { |
| 239 | if (c < 0) { |
| 240 | u.u_error = EFAULT; |
| 241 | return; |
| 242 | } |
| 243 | tp++; |
| 244 | nc++; |
| 245 | } |
| 246 | u.u_dirp = uap->linkname; |
| 247 | ip = namei(uchar, 1, 0); |
| 248 | if (ip) { |
| 249 | iput(ip); |
| 250 | u.u_error = EEXIST; |
| 251 | return; |
| 252 | } |
| 253 | if (u.u_error) |
| 254 | return; |
| 255 | ip = maknode(IFLNK | 0777); |
| 256 | if (ip == NULL) |
| 257 | return; |
| 258 | u.u_base = uap->target; |
| 259 | u.u_count = nc; |
| 260 | u.u_offset = 0; |
| 261 | u.u_segflg = 0; |
| 262 | writei(ip); |
| 263 | iput(ip); |
| 264 | } |
| 265 | |
| 266 | /* |
| 267 | * Unlink system call. |
| 268 | * Hard to avoid races here, especially |
| 269 | * in unlinking directories. |
| 270 | */ |
| 271 | unlink() |
| 272 | { |
| 273 | register struct inode *ip, *pp; |
| 274 | struct a { |
| 275 | char *fname; |
| 276 | }; |
| 277 | struct fs *fs; |
| 278 | struct buf *bp; |
| 279 | int lbn, bn, base; |
| 280 | int unlinkingdot = 0; |
| 281 | |
| 282 | pp = namei(uchar, 2, 0); |
| 283 | if(pp == NULL) |
| 284 | return; |
| 285 | /* |
| 286 | * Check for unlink(".") |
| 287 | * to avoid hanging on the iget |
| 288 | */ |
| 289 | if (pp->i_number == u.u_dent.d_ino) { |
| 290 | ip = pp; |
| 291 | ip->i_count++; |
| 292 | unlinkingdot++; |
| 293 | } else |
| 294 | ip = iget(pp->i_dev, pp->i_fs, u.u_dent.d_ino); |
| 295 | if(ip == NULL) |
| 296 | goto out1; |
| 297 | if((ip->i_mode&IFMT)==IFDIR && !suser()) |
| 298 | goto out; |
| 299 | /* |
| 300 | * Don't unlink a mounted file. |
| 301 | */ |
| 302 | if (ip->i_dev != pp->i_dev) { |
| 303 | u.u_error = EBUSY; |
| 304 | goto out; |
| 305 | } |
| 306 | if (ip->i_flag&ITEXT) |
| 307 | xrele(ip); /* try once to free text */ |
| 308 | /* |
| 309 | if ((ip->i_flag&ITEXT) && ip->i_nlink==1) { |
| 310 | u.u_error = ETXTBSY; |
| 311 | goto out; |
| 312 | } |
| 313 | */ |
| 314 | if (u.u_count == 0) { |
| 315 | /* |
| 316 | * first entry in block, so set d_ino to zero. |
| 317 | */ |
| 318 | u.u_base = (caddr_t)&u.u_dent; |
| 319 | u.u_count = DIRSIZ(&u.u_dent); |
| 320 | u.u_dent.d_ino = 0; |
| 321 | writei(pp); |
| 322 | } else { |
| 323 | /* |
| 324 | * updating preceeding entry to skip over current entry. |
| 325 | */ |
| 326 | fs = pp->i_fs; |
| 327 | lbn = lblkno(fs, u.u_offset); |
| 328 | base = blkoff(fs, u.u_offset); |
| 329 | bn = fsbtodb(fs, bmap(pp, lbn, B_WRITE, base + u.u_count)); |
| 330 | bp = bread(pp->i_dev, bn, blksize(fs, pp, lbn)); |
| 331 | if (bp->b_flags & B_ERROR) { |
| 332 | brelse(bp); |
| 333 | goto out; |
| 334 | } |
| 335 | ((struct direct *)(bp->b_un.b_addr + base))->d_reclen += |
| 336 | u.u_dent.d_reclen; |
| 337 | bwrite(bp); |
| 338 | pp->i_flag |= IUPD|ICHG; |
| 339 | } |
| 340 | ip->i_nlink--; |
| 341 | ip->i_flag |= ICHG; |
| 342 | |
| 343 | out: |
| 344 | if (unlinkingdot) |
| 345 | irele(ip); |
| 346 | else |
| 347 | iput(ip); |
| 348 | out1: |
| 349 | iput(pp); |
| 350 | } |
| 351 | |
| 352 | /* |
| 353 | * Seek system call |
| 354 | */ |
| 355 | seek() |
| 356 | { |
| 357 | register struct file *fp; |
| 358 | register struct a { |
| 359 | int fdes; |
| 360 | off_t off; |
| 361 | int sbase; |
| 362 | } *uap; |
| 363 | |
| 364 | uap = (struct a *)u.u_ap; |
| 365 | fp = getf(uap->fdes); |
| 366 | if (fp == NULL) |
| 367 | return; |
| 368 | if (fp->f_flag&FSOCKET) { |
| 369 | u.u_error = ESPIPE; |
| 370 | return; |
| 371 | } |
| 372 | if (uap->sbase == 1) |
| 373 | uap->off += fp->f_offset; |
| 374 | else if (uap->sbase == 2) |
| 375 | uap->off += fp->f_inode->i_size; |
| 376 | fp->f_offset = uap->off; |
| 377 | u.u_r.r_off = uap->off; |
| 378 | } |
| 379 | |
| 380 | /* |
| 381 | * Access system call |
| 382 | */ |
| 383 | saccess() |
| 384 | { |
| 385 | register svuid, svgid; |
| 386 | register struct inode *ip; |
| 387 | register struct a { |
| 388 | char *fname; |
| 389 | int fmode; |
| 390 | } *uap; |
| 391 | |
| 392 | uap = (struct a *)u.u_ap; |
| 393 | svuid = u.u_uid; |
| 394 | svgid = u.u_gid; |
| 395 | u.u_uid = u.u_ruid; |
| 396 | u.u_gid = u.u_rgid; |
| 397 | ip = namei(uchar, 0, 1); |
| 398 | if (ip != NULL) { |
| 399 | if (uap->fmode&(IREAD>>6)) |
| 400 | (void) access(ip, IREAD); |
| 401 | if (uap->fmode&(IWRITE>>6)) |
| 402 | (void) access(ip, IWRITE); |
| 403 | if (uap->fmode&(IEXEC>>6)) |
| 404 | (void) access(ip, IEXEC); |
| 405 | iput(ip); |
| 406 | } |
| 407 | u.u_uid = svuid; |
| 408 | u.u_gid = svgid; |
| 409 | } |
| 410 | |
| 411 | /* |
| 412 | * the fstat system call. |
| 413 | */ |
| 414 | fstat() |
| 415 | { |
| 416 | register struct file *fp; |
| 417 | register struct a { |
| 418 | int fdes; |
| 419 | struct stat *sb; |
| 420 | } *uap; |
| 421 | |
| 422 | uap = (struct a *)u.u_ap; |
| 423 | fp = getf(uap->fdes); |
| 424 | if (fp == NULL) |
| 425 | return; |
| 426 | if (fp->f_flag & FSOCKET) |
| 427 | u.u_error = sostat(fp->f_socket, uap->sb); |
| 428 | else |
| 429 | stat1(fp->f_inode, uap->sb); |
| 430 | } |
| 431 | |
| 432 | /* |
| 433 | * Stat system call. This version follows links. |
| 434 | */ |
| 435 | stat() |
| 436 | { |
| 437 | register struct inode *ip; |
| 438 | register struct a { |
| 439 | char *fname; |
| 440 | struct stat *sb; |
| 441 | } *uap; |
| 442 | |
| 443 | uap = (struct a *)u.u_ap; |
| 444 | ip = namei(uchar, 0, 1); |
| 445 | if (ip == NULL) |
| 446 | return; |
| 447 | stat1(ip, uap->sb); |
| 448 | iput(ip); |
| 449 | } |
| 450 | |
| 451 | /* |
| 452 | * Lstat system call. This version does not follow links. |
| 453 | */ |
| 454 | lstat() |
| 455 | { |
| 456 | register struct inode *ip; |
| 457 | register struct a { |
| 458 | char *fname; |
| 459 | struct stat *sb; |
| 460 | } *uap; |
| 461 | |
| 462 | uap = (struct a *)u.u_ap; |
| 463 | ip = namei(uchar, 0, 0); |
| 464 | if (ip == NULL) |
| 465 | return; |
| 466 | stat1(ip, uap->sb); |
| 467 | iput(ip); |
| 468 | } |
| 469 | |
| 470 | /* |
| 471 | * The basic routine for fstat and stat: |
| 472 | * get the inode and pass appropriate parts back. |
| 473 | */ |
| 474 | stat1(ip, ub) |
| 475 | register struct inode *ip; |
| 476 | struct stat *ub; |
| 477 | { |
| 478 | struct stat ds; |
| 479 | |
| 480 | IUPDAT(ip, &time, &time, 0); |
| 481 | /* |
| 482 | * Copy from inode table |
| 483 | */ |
| 484 | ds.st_dev = ip->i_dev; |
| 485 | ds.st_ino = ip->i_number; |
| 486 | ds.st_mode = ip->i_mode; |
| 487 | ds.st_nlink = ip->i_nlink; |
| 488 | ds.st_uid = ip->i_uid; |
| 489 | ds.st_gid = ip->i_gid; |
| 490 | ds.st_rdev = (dev_t)ip->i_rdev; |
| 491 | ds.st_size = ip->i_size; |
| 492 | ds.st_atime = ip->i_atime; |
| 493 | ds.st_mtime = ip->i_mtime; |
| 494 | ds.st_ctime = ip->i_ctime; |
| 495 | ds.st_blksize = ip->i_fs->fs_bsize; |
| 496 | if (copyout((caddr_t)&ds, (caddr_t)ub, sizeof(ds)) < 0) |
| 497 | u.u_error = EFAULT; |
| 498 | } |
| 499 | |
| 500 | /* |
| 501 | * Return target name of a symbolic link |
| 502 | */ |
| 503 | readlink() |
| 504 | { |
| 505 | register struct inode *ip; |
| 506 | register struct a { |
| 507 | char *name; |
| 508 | char *buf; |
| 509 | int count; |
| 510 | } *uap; |
| 511 | |
| 512 | ip = namei(uchar, 0, 0); |
| 513 | if (ip == NULL) |
| 514 | return; |
| 515 | if ((ip->i_mode&IFMT) != IFLNK) { |
| 516 | u.u_error = ENXIO; |
| 517 | goto out; |
| 518 | } |
| 519 | uap = (struct a *)u.u_ap; |
| 520 | u.u_offset = 0; |
| 521 | u.u_base = uap->buf; |
| 522 | u.u_count = uap->count; |
| 523 | u.u_segflg = 0; |
| 524 | readi(ip); |
| 525 | out: |
| 526 | iput(ip); |
| 527 | u.u_r.r_val1 = uap->count - u.u_count; |
| 528 | } |
| 529 | |
| 530 | chmod() |
| 531 | { |
| 532 | register struct inode *ip; |
| 533 | register struct a { |
| 534 | char *fname; |
| 535 | int fmode; |
| 536 | } *uap; |
| 537 | |
| 538 | uap = (struct a *)u.u_ap; |
| 539 | if ((ip = owner(1)) == NULL) |
| 540 | return; |
| 541 | ip->i_mode &= ~07777; |
| 542 | if (u.u_uid) |
| 543 | uap->fmode &= ~ISVTX; |
| 544 | ip->i_mode |= uap->fmode&07777; |
| 545 | ip->i_flag |= ICHG; |
| 546 | if (ip->i_flag&ITEXT && (ip->i_mode&ISVTX)==0) |
| 547 | xrele(ip); |
| 548 | iput(ip); |
| 549 | } |
| 550 | |
| 551 | chown() |
| 552 | { |
| 553 | register struct inode *ip; |
| 554 | register struct a { |
| 555 | char *fname; |
| 556 | int uid; |
| 557 | int gid; |
| 558 | } *uap; |
| 559 | |
| 560 | uap = (struct a *)u.u_ap; |
| 561 | if (!suser() || (ip = owner(0)) == NULL) |
| 562 | return; |
| 563 | ip->i_uid = uap->uid; |
| 564 | ip->i_gid = uap->gid; |
| 565 | ip->i_flag |= ICHG; |
| 566 | if (u.u_ruid != 0) |
| 567 | ip->i_mode &= ~(ISUID|ISGID); |
| 568 | iput(ip); |
| 569 | } |
| 570 | |
| 571 | /* |
| 572 | * Set IUPD and IACC times on file. |
| 573 | * Can't set ICHG. |
| 574 | */ |
| 575 | utime() |
| 576 | { |
| 577 | register struct a { |
| 578 | char *fname; |
| 579 | time_t *tptr; |
| 580 | } *uap; |
| 581 | register struct inode *ip; |
| 582 | time_t tv[2]; |
| 583 | |
| 584 | uap = (struct a *)u.u_ap; |
| 585 | if ((ip = owner(1)) == NULL) |
| 586 | return; |
| 587 | if (copyin((caddr_t)uap->tptr, (caddr_t)tv, sizeof(tv))) { |
| 588 | u.u_error = EFAULT; |
| 589 | } else { |
| 590 | ip->i_flag |= IACC|IUPD|ICHG; |
| 591 | iupdat(ip, &tv[0], &tv[1], 0); |
| 592 | } |
| 593 | iput(ip); |
| 594 | } |
| 595 | |
| 596 | sync() |
| 597 | { |
| 598 | |
| 599 | update(0); |
| 600 | } |