1 /* vfs_syscalls.c 4.28 82/07/15 */ 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 #ifdef EFS 15 #include "../net/in.h" 16 #include "../h/efs.h" 17 #endif 18 19 chdir() 20 { 21 22 chdirec(&u.u_cdir); 23 } 24 25 chroot() 26 { 27 28 if (suser()) 29 chdirec(&u.u_rdir); 30 } 31 32 chdirec(ipp) 33 register struct inode **ipp; 34 { 35 register struct inode *ip; 36 struct a { 37 char *fname; 38 }; 39 40 ip = namei(uchar, 0, 1); 41 if(ip == NULL) 42 return; 43 if((ip->i_mode&IFMT) != IFDIR) { 44 u.u_error = ENOTDIR; 45 goto bad; 46 } 47 if(access(ip, IEXEC)) 48 goto bad; 49 iunlock(ip); 50 if (*ipp) 51 irele(*ipp); 52 *ipp = ip; 53 return; 54 55 bad: 56 iput(ip); 57 } 58 59 /* 60 * Open system call. 61 */ 62 open() 63 { 64 register struct inode *ip; 65 register struct a { 66 char *fname; 67 int rwmode; 68 } *uap; 69 70 uap = (struct a *)u.u_ap; 71 ip = namei(uchar, 0, 1); 72 if (ip == NULL) 73 return; 74 open1(ip, ++uap->rwmode, 0); 75 } 76 77 /* 78 * Creat system call. 79 */ 80 creat() 81 { 82 register struct inode *ip; 83 register struct a { 84 char *fname; 85 int fmode; 86 } *uap; 87 88 uap = (struct a *)u.u_ap; 89 ip = namei(uchar, 1, 1); 90 if (ip == NULL) { 91 if (u.u_error) 92 return; 93 ip = maknode(uap->fmode&07777&(~ISVTX)); 94 if (ip==NULL) 95 return; 96 open1(ip, FWRITE, 2); 97 } else 98 open1(ip, FWRITE, 1); 99 } 100 101 /* 102 * Common code for open and creat. 103 * Check permissions, allocate an open file structure, 104 * and call the device open routine if any. 105 */ 106 open1(ip, mode, trf) 107 register struct inode *ip; 108 register mode; 109 { 110 register struct file *fp; 111 int i; 112 113 if (trf != 2) { 114 if (mode&FREAD) 115 (void) access(ip, IREAD); 116 if (mode&FWRITE) { 117 (void) access(ip, IWRITE); 118 if ((ip->i_mode&IFMT) == IFDIR) 119 u.u_error = EISDIR; 120 } 121 } 122 if (u.u_error) { 123 iput(ip); 124 return; 125 } 126 if (trf == 1) 127 itrunc(ip); 128 iunlock(ip); 129 if ((fp = falloc()) == NULL) 130 goto out; 131 fp->f_flag = mode&(FREAD|FWRITE); 132 i = u.u_r.r_val1; 133 fp->f_inode = ip; 134 #ifdef EFS 135 openi(ip, mode&(FREAD|FWRITE), trf); 136 #else 137 openi(ip, mode&(FREAD|FWRITE)); 138 #endif 139 if (u.u_error == 0) 140 return; 141 u.u_ofile[i] = NULL; 142 fp->f_count--; 143 out: 144 irele(ip); 145 } 146 147 /* 148 * Mknod system call 149 */ 150 mknod() 151 { 152 register struct inode *ip; 153 register struct a { 154 char *fname; 155 int fmode; 156 int dev; 157 } *uap; 158 159 uap = (struct a *)u.u_ap; 160 if (suser()) { 161 ip = namei(uchar, 1, 0); 162 if (ip != NULL) { 163 u.u_error = EEXIST; 164 goto out; 165 } 166 } 167 if (u.u_error) 168 return; 169 ip = maknode(uap->fmode); 170 if (ip == NULL) 171 return; 172 if (uap->dev) { 173 /* 174 * Want to be able to use this to make badblock 175 * inodes, so don't truncate the dev number. 176 */ 177 ip->i_rdev = uap->dev; 178 ip->i_flag |= IACC|IUPD|ICHG; 179 } 180 181 out: 182 iput(ip); 183 } 184 185 /* 186 * link system call 187 */ 188 link() 189 { 190 register struct inode *ip, *xp; 191 register struct a { 192 char *target; 193 char *linkname; 194 } *uap; 195 196 uap = (struct a *)u.u_ap; 197 ip = namei(uchar, 0, 1); /* well, this routine is doomed anyhow */ 198 if (ip == NULL) 199 return; 200 if ((ip->i_mode&IFMT)==IFDIR && !suser()) { 201 iput(ip); 202 return; 203 } 204 ip->i_nlink++; 205 ip->i_flag |= ICHG; 206 iupdat(ip, &time, &time, 1); 207 iunlock(ip); 208 u.u_dirp = (caddr_t)uap->linkname; 209 xp = namei(uchar, 1, 0); 210 if (xp != NULL) { 211 u.u_error = EEXIST; 212 iput(xp); 213 goto out; 214 } 215 if (u.u_error) 216 goto out; 217 if (u.u_pdir->i_dev != ip->i_dev) { 218 iput(u.u_pdir); 219 u.u_error = EXDEV; 220 goto out; 221 } 222 wdir(ip); 223 out: 224 if (u.u_error) { 225 ip->i_nlink--; 226 ip->i_flag |= ICHG; 227 } 228 out1: 229 irele(ip); 230 } 231 232 /* 233 * symlink -- make a symbolic link 234 */ 235 symlink() 236 { 237 register struct a { 238 char *target; 239 char *linkname; 240 } *uap; 241 register struct inode *ip; 242 register char *tp; 243 register c, nc; 244 245 uap = (struct a *)u.u_ap; 246 tp = uap->target; 247 nc = 0; 248 while (c = fubyte(tp)) { 249 if (c < 0) { 250 u.u_error = EFAULT; 251 return; 252 } 253 tp++; 254 nc++; 255 } 256 u.u_dirp = uap->linkname; 257 ip = namei(uchar, 1, 0); 258 if (ip) { 259 iput(ip); 260 u.u_error = EEXIST; 261 return; 262 } 263 if (u.u_error) 264 return; 265 ip = maknode(IFLNK | 0777); 266 if (ip == NULL) 267 return; 268 u.u_base = uap->target; 269 u.u_count = nc; 270 u.u_offset = 0; 271 u.u_segflg = 0; 272 writei(ip); 273 iput(ip); 274 } 275 276 /* 277 * Unlink system call. 278 * Hard to avoid races here, especially 279 * in unlinking directories. 280 */ 281 unlink() 282 { 283 register struct inode *ip, *pp; 284 struct a { 285 char *fname; 286 }; 287 struct fs *fs; 288 struct buf *bp; 289 int lbn, bn, base; 290 int unlinkingdot = 0; 291 292 pp = namei(uchar, 2, 0); 293 if(pp == NULL) 294 return; 295 #ifdef EFS 296 /* divert to extended file system if off machine. */ 297 if (efsinode(pp)) { 298 dev_t ndev = pp->i_rdev; 299 300 iput(pp); /* avoid recursive hang on inode */ 301 efsunlink(ndev); 302 if (u.u_error != EEXIST) 303 return; 304 305 /* 306 * If a null pathname remainder, then do 307 * the unlink locally after restoring state. 308 */ 309 u.u_error = 0; 310 u.u_dirp = (caddr_t)u.u_arg[0]; 311 pp = namei(uchar, 2, 0); 312 } 313 #endif 314 315 /* 316 * Check for unlink(".") 317 * to avoid hanging on the iget 318 */ 319 if (pp->i_number == u.u_dent.d_ino) { 320 ip = pp; 321 ip->i_count++; 322 unlinkingdot++; 323 } else 324 ip = iget(pp->i_dev, pp->i_fs, u.u_dent.d_ino); 325 if(ip == NULL) 326 goto out1; 327 if((ip->i_mode&IFMT)==IFDIR && !suser()) 328 goto out; 329 /* 330 * Don't unlink a mounted file. 331 */ 332 if (ip->i_dev != pp->i_dev) { 333 u.u_error = EBUSY; 334 goto out; 335 } 336 if (ip->i_flag&ITEXT) 337 xrele(ip); /* try once to free text */ 338 /* 339 if ((ip->i_flag&ITEXT) && ip->i_nlink==1) { 340 u.u_error = ETXTBSY; 341 goto out; 342 } 343 */ 344 if (u.u_count == 0) { 345 /* 346 * first entry in block, so set d_ino to zero. 347 */ 348 u.u_base = (caddr_t)&u.u_dent; 349 u.u_count = DIRSIZ(&u.u_dent); 350 u.u_dent.d_ino = 0; 351 writei(pp); 352 } else { 353 /* 354 * updating preceeding entry to skip over current entry. 355 */ 356 fs = pp->i_fs; 357 lbn = lblkno(fs, u.u_offset); 358 base = blkoff(fs, u.u_offset); 359 bn = fsbtodb(fs, bmap(pp, lbn, B_WRITE, base + u.u_count)); 360 bp = bread(pp->i_dev, bn, blksize(fs, pp, lbn)); 361 if (bp->b_flags & B_ERROR) { 362 brelse(bp); 363 goto out; 364 } 365 ((struct direct *)(bp->b_un.b_addr + base))->d_reclen += 366 u.u_dent.d_reclen; 367 bwrite(bp); 368 pp->i_flag |= IUPD|ICHG; 369 } 370 ip->i_nlink--; 371 ip->i_flag |= ICHG; 372 373 out: 374 if (unlinkingdot) 375 irele(ip); 376 else 377 iput(ip); 378 out1: 379 iput(pp); 380 } 381 382 /* 383 * Seek system call 384 */ 385 seek() 386 { 387 register struct file *fp; 388 register struct a { 389 int fdes; 390 off_t off; 391 int sbase; 392 } *uap; 393 394 uap = (struct a *)u.u_ap; 395 fp = getf(uap->fdes); 396 if (fp == NULL) 397 return; 398 if (fp->f_flag&FSOCKET) { 399 u.u_error = ESPIPE; 400 return; 401 } 402 if (uap->sbase == 1) 403 uap->off += fp->f_offset; 404 else if (uap->sbase == 2) { 405 #ifdef EFS 406 struct inode *ip = fp->f_inode; 407 uap->off += efsinode(ip) ? efsfilesize(fp) : ip->i_size; 408 #else 409 uap->off += fp->f_inode->i_size; 410 #endif 411 } 412 fp->f_offset = uap->off; 413 u.u_r.r_off = uap->off; 414 } 415 416 /* 417 * Access system call 418 */ 419 saccess() 420 { 421 register svuid, svgid; 422 register struct inode *ip; 423 register struct a { 424 char *fname; 425 int fmode; 426 } *uap; 427 428 uap = (struct a *)u.u_ap; 429 svuid = u.u_uid; 430 svgid = u.u_gid; 431 u.u_uid = u.u_ruid; 432 u.u_gid = u.u_rgid; 433 ip = namei(uchar, 0, 1); 434 #ifdef EFS 435 if (efsinode(ip)) { 436 dev_t ndev = ip->i_rdev; 437 438 iput(ip); 439 efssaccess(ndev); 440 if (u.u_error != EEXIST) 441 return; 442 u.u_error = 0; 443 u.u_dirp = (caddr_t)u.u_arg[0]; 444 ip = namei(uchar, 0, 1); 445 } 446 #endif 447 if (ip != NULL) { 448 if (uap->fmode&(IREAD>>6)) 449 (void) access(ip, IREAD); 450 if (uap->fmode&(IWRITE>>6)) 451 (void) access(ip, IWRITE); 452 if (uap->fmode&(IEXEC>>6)) 453 (void) access(ip, IEXEC); 454 iput(ip); 455 } 456 u.u_uid = svuid; 457 u.u_gid = svgid; 458 } 459 460 /* 461 * the fstat system call. 462 */ 463 fstat() 464 { 465 register struct file *fp; 466 register struct a { 467 int fdes; 468 struct stat *sb; 469 } *uap; 470 471 uap = (struct a *)u.u_ap; 472 fp = getf(uap->fdes); 473 if (fp == NULL) 474 return; 475 #ifdef EFS 476 if (efsinode(fp->f_inode)) { 477 efsfstat(fp->f_inode->i_rdev, fp); 478 return; 479 } 480 #endif 481 if (fp->f_flag & FSOCKET) 482 u.u_error = sostat(fp->f_socket, uap->sb); 483 else 484 stat1(fp->f_inode, uap->sb); 485 } 486 487 /* 488 * Stat system call. This version follows links. 489 */ 490 stat() 491 { 492 register struct inode *ip; 493 register struct a { 494 char *fname; 495 struct stat *sb; 496 } *uap; 497 498 uap = (struct a *)u.u_ap; 499 ip = namei(uchar, 0, 1); 500 if (ip == NULL) 501 return; 502 #ifdef EFS 503 if (efsinode(ip)) { 504 dev_t ndev = ip->i_rdev; 505 506 iput(ip); 507 efsstat(ndev); 508 if (u.u_error != EEXIST) 509 return; 510 u.u_error = 0; 511 u.u_dirp = (caddr_t)u.u_arg[0]; 512 ip = namei(uchar, 0, 1); 513 } 514 #endif 515 stat1(ip, uap->sb); 516 iput(ip); 517 } 518 519 /* 520 * Lstat system call. This version does not follow links. 521 */ 522 lstat() 523 { 524 register struct inode *ip; 525 register struct a { 526 char *fname; 527 struct stat *sb; 528 } *uap; 529 530 uap = (struct a *)u.u_ap; 531 ip = namei(uchar, 0, 0); 532 if (ip == NULL) 533 return; 534 #ifdef EFS 535 if (efsinode(ip)) { 536 dev_t ndev = ip->i_rdev; 537 538 iput(ip); 539 efslstat(ndev); 540 if (u.u_error != EEXIST) 541 return; 542 u.u_error = 0; 543 u.u_dirp = (caddr_t)u.u_arg[0]; 544 ip = namei(uchar, 0, 0); 545 } 546 #endif 547 stat1(ip, uap->sb); 548 iput(ip); 549 } 550 551 /* 552 * The basic routine for fstat and stat: 553 * get the inode and pass appropriate parts back. 554 */ 555 stat1(ip, ub) 556 register struct inode *ip; 557 struct stat *ub; 558 { 559 struct stat ds; 560 561 IUPDAT(ip, &time, &time, 0); 562 /* 563 * Copy from inode table 564 */ 565 ds.st_dev = ip->i_dev; 566 ds.st_ino = ip->i_number; 567 ds.st_mode = ip->i_mode; 568 ds.st_nlink = ip->i_nlink; 569 ds.st_uid = ip->i_uid; 570 ds.st_gid = ip->i_gid; 571 ds.st_rdev = (dev_t)ip->i_rdev; 572 ds.st_size = ip->i_size; 573 ds.st_atime = ip->i_atime; 574 ds.st_mtime = ip->i_mtime; 575 ds.st_ctime = ip->i_ctime; 576 ds.st_blksize = ip->i_fs->fs_bsize; 577 if (copyout((caddr_t)&ds, (caddr_t)ub, sizeof(ds)) < 0) 578 u.u_error = EFAULT; 579 } 580 581 /* 582 * Return target name of a symbolic link 583 */ 584 readlink() 585 { 586 register struct inode *ip; 587 register struct a { 588 char *name; 589 char *buf; 590 int count; 591 } *uap; 592 593 ip = namei(uchar, 0, 0); 594 if (ip == NULL) 595 return; 596 #ifdef EFS 597 if (efsinode(ip)) { 598 dev_t ndev = ip->i_rdev; 599 600 iput(ip); 601 efsreadlink(ndev); 602 if (u.u_error != EEXIST) 603 return; 604 u.u_error = 0; 605 u.u_dirp = (caddr_t)u.u_arg[0]; 606 ip = namei(uchar, 0, 0); 607 return (0); 608 } 609 #endif 610 if ((ip->i_mode&IFMT) != IFLNK) { 611 u.u_error = ENXIO; 612 goto out; 613 } 614 uap = (struct a *)u.u_ap; 615 u.u_offset = 0; 616 u.u_base = uap->buf; 617 u.u_count = uap->count; 618 u.u_segflg = 0; 619 readi(ip); 620 out: 621 iput(ip); 622 u.u_r.r_val1 = uap->count - u.u_count; 623 } 624 625 chmod() 626 { 627 register struct inode *ip; 628 register struct a { 629 char *fname; 630 int fmode; 631 } *uap; 632 633 uap = (struct a *)u.u_ap; 634 if ((ip = owner(1)) == NULL) 635 return; 636 #ifdef EFS 637 if (efsinode(ip)) { 638 dev_t ndev = ip->i_rdev; 639 640 iput(ip); 641 efschmod(ndev); 642 if (u.u_error != EEXIST) 643 return; 644 u.u_error = 0; 645 u.u_dirp = (caddr_t)u.u_arg[0]; 646 ip = owner(1); 647 } 648 #endif 649 ip->i_mode &= ~07777; 650 if (u.u_uid) { 651 uap->fmode &= ~ISVTX; 652 if (ip->i_gid >= NGRPS || 653 (u.u_grps[ip->i_gid/(sizeof(int)*8)] & 654 (1 << ip->i_gid%(sizeof(int)*8))) == 0) 655 uap->fmode &= ~ISGID; 656 } 657 ip->i_mode |= uap->fmode&07777; 658 ip->i_flag |= ICHG; 659 if (ip->i_flag&ITEXT && (ip->i_mode&ISVTX)==0) 660 xrele(ip); 661 iput(ip); 662 } 663 664 chown() 665 { 666 register struct inode *ip; 667 register struct a { 668 char *fname; 669 int uid; 670 int gid; 671 } *uap; 672 673 uap = (struct a *)u.u_ap; 674 if (!suser() || (ip = owner(0)) == NULL) 675 return; 676 #ifdef EFS 677 if (efsinode(ip)) { 678 dev_t ndev = ip->i_rdev; 679 680 iput(ip); 681 efschown(ndev); 682 if (u.u_error != EEXIST) 683 return; 684 u.u_error = 0; 685 u.u_dirp = (caddr_t)u.u_arg[0]; 686 ip = owner(0); 687 } 688 #endif 689 /* 690 * keep uid/gid's in sane range - no err, so chown(file, uid, -1) 691 * will do something useful 692 */ 693 if (uap->uid >= 0 && uap->uid <= 32767) /* should have a const */ 694 ip->i_uid = uap->uid; 695 if (uap->gid >= 0 && uap->gid <= 32767) /* same here */ 696 ip->i_gid = uap->gid; 697 ip->i_flag |= ICHG; 698 if (u.u_ruid != 0) 699 ip->i_mode &= ~(ISUID|ISGID); 700 iput(ip); 701 } 702 703 /* 704 * Set IUPD and IACC times on file. 705 * Can't set ICHG. 706 */ 707 utime() 708 { 709 register struct a { 710 char *fname; 711 time_t *tptr; 712 } *uap; 713 register struct inode *ip; 714 time_t tv[2]; 715 716 uap = (struct a *)u.u_ap; 717 if ((ip = owner(1)) == NULL) 718 return; 719 if (copyin((caddr_t)uap->tptr, (caddr_t)tv, sizeof(tv))) { 720 u.u_error = EFAULT; 721 } else { 722 #ifdef EFS 723 if (efsinode(ip)) { 724 dev_t ndev = ip->i_rdev; 725 726 iput(ip); 727 efsutime(ndev, uap->fname, tv); 728 if (u.u_error != EEXIST) 729 return; 730 u.u_error = 0; 731 u.u_dirp = (caddr_t)u.u_arg[0]; 732 ip = owner(1); 733 } 734 #endif 735 ip->i_flag |= IACC|IUPD|ICHG; 736 iupdat(ip, &tv[0], &tv[1], 0); 737 } 738 iput(ip); 739 } 740 741 sync() 742 { 743 744 update(0); 745 } 746