kern_descrip.c revision 1.27
1 /* $NetBSD: kern_descrip.c,v 1.27 1994/12/04 03:09:50 mycroft Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 41 */ 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/filedesc.h> 46 #include <sys/kernel.h> 47 #include <sys/vnode.h> 48 #include <sys/proc.h> 49 #include <sys/file.h> 50 #include <sys/socket.h> 51 #include <sys/socketvar.h> 52 #include <sys/stat.h> 53 #include <sys/ioctl.h> 54 #include <sys/fcntl.h> 55 #include <sys/malloc.h> 56 #include <sys/syslog.h> 57 #include <sys/unistd.h> 58 #include <sys/resourcevar.h> 59 60 #include <sys/mount.h> 61 #include <sys/syscallargs.h> 62 63 /* 64 * Descriptor management. 65 */ 66 struct filelist filehead; /* head of list of open files */ 67 int nfiles; /* actual number of open files */ 68 69 static __inline 70 fd_used(fdp, fd) 71 register struct filedesc *fdp; 72 register int fd; 73 { 74 75 if (fd > fdp->fd_lastfile) 76 fdp->fd_lastfile = fd; 77 } 78 79 static __inline 80 fd_unused(fdp, fd) 81 register struct filedesc *fdp; 82 register int fd; 83 { 84 85 if (fd < fdp->fd_freefile) 86 fdp->fd_freefile = fd; 87 #ifdef DIAGNOSTIC 88 if (fd > fdp->fd_lastfile) 89 panic("fd_unused: fd_lastfile inconsistent"); 90 #endif 91 if (fd == fdp->fd_lastfile) { 92 do { 93 fd--; 94 } while (fd >= 0 && fdp->fd_ofiles[fd] == NULL); 95 fdp->fd_lastfile = fd; 96 } 97 } 98 99 /* 100 * System calls on descriptors. 101 */ 102 103 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) || defined(COMPAT_ULTRIX) || defined(COMPAT_HPUX) 104 /* ARGSUSED */ 105 compat_43_getdtablesize(p, uap, retval) 106 struct proc *p; 107 void *uap; 108 register_t *retval; 109 { 110 111 *retval = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles); 112 return (0); 113 } 114 #endif 115 116 /* 117 * Duplicate a file descriptor. 118 */ 119 /* ARGSUSED */ 120 dup(p, uap, retval) 121 struct proc *p; 122 struct dup_args /* { 123 syscallarg(u_int) fd; 124 } */ *uap; 125 register_t *retval; 126 { 127 register struct filedesc *fdp = p->p_fd; 128 register int old = SCARG(uap, fd); 129 int new; 130 int error; 131 132 if ((u_int)old >= fdp->fd_nfiles || fdp->fd_ofiles[old] == NULL) 133 return (EBADF); 134 if (error = fdalloc(p, 0, &new)) 135 return (error); 136 return (finishdup(fdp, old, new, retval)); 137 } 138 139 /* 140 * Duplicate a file descriptor to a particular value. 141 */ 142 /* ARGSUSED */ 143 dup2(p, uap, retval) 144 struct proc *p; 145 struct dup2_args /* { 146 syscallarg(u_int) from; 147 syscallarg(u_int) to; 148 } */ *uap; 149 register_t *retval; 150 { 151 register struct filedesc *fdp = p->p_fd; 152 register int old = SCARG(uap, from), new = SCARG(uap, to); 153 int i, error; 154 155 if ((u_int)old >= fdp->fd_nfiles || fdp->fd_ofiles[old] == NULL || 156 (u_int)new >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur || 157 (u_int)new >= maxfiles) 158 return (EBADF); 159 if (old == new) { 160 *retval = new; 161 return (0); 162 } 163 if (new >= fdp->fd_nfiles) { 164 if (error = fdalloc(p, new, &i)) 165 return (error); 166 if (new != i) 167 panic("dup2: fdalloc"); 168 } else { 169 (void) fdclose(p, new); 170 } 171 return (finishdup(fdp, old, new, retval)); 172 } 173 174 /* 175 * The file control system call. 176 */ 177 /* ARGSUSED */ 178 fcntl(p, uap, retval) 179 struct proc *p; 180 register struct fcntl_args /* { 181 syscallarg(int) fd; 182 syscallarg(int) cmd; 183 syscallarg(void *) arg; 184 } */ *uap; 185 register_t *retval; 186 { 187 int fd = SCARG(uap, fd); 188 register struct filedesc *fdp = p->p_fd; 189 register struct file *fp; 190 struct vnode *vp; 191 int i, tmp, error, flg = F_POSIX; 192 struct flock fl; 193 int newmin; 194 195 if ((u_int)fd >= fdp->fd_nfiles || 196 (fp = fdp->fd_ofiles[fd]) == NULL) 197 return (EBADF); 198 switch (SCARG(uap, cmd)) { 199 200 case F_DUPFD: 201 newmin = (int)SCARG(uap, arg); 202 if ((u_int)newmin >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur || 203 (u_int)newmin >= maxfiles) 204 return (EINVAL); 205 if (error = fdalloc(p, newmin, &i)) 206 return (error); 207 return (finishdup(fdp, fd, i, retval)); 208 209 case F_GETFD: 210 *retval = fdp->fd_ofileflags[fd] & UF_EXCLOSE ? 1 : 0; 211 return (0); 212 213 case F_SETFD: 214 if ((long)SCARG(uap, arg) & 1) 215 fdp->fd_ofileflags[fd] |= UF_EXCLOSE; 216 else 217 fdp->fd_ofileflags[fd] &= ~UF_EXCLOSE; 218 return (0); 219 220 case F_GETFL: 221 *retval = OFLAGS(fp->f_flag); 222 return (0); 223 224 case F_SETFL: 225 fp->f_flag &= ~FCNTLFLAGS; 226 fp->f_flag |= FFLAGS((long)SCARG(uap, arg)) & FCNTLFLAGS; 227 tmp = fp->f_flag & FNONBLOCK; 228 error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p); 229 if (error) 230 return (error); 231 tmp = fp->f_flag & FASYNC; 232 error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, (caddr_t)&tmp, p); 233 if (!error) 234 return (0); 235 fp->f_flag &= ~FNONBLOCK; 236 tmp = 0; 237 (void) (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p); 238 return (error); 239 240 case F_GETOWN: 241 if (fp->f_type == DTYPE_SOCKET) { 242 *retval = ((struct socket *)fp->f_data)->so_pgid; 243 return (0); 244 } 245 error = (*fp->f_ops->fo_ioctl) 246 (fp, (int)TIOCGPGRP, (caddr_t)retval, p); 247 *retval = -*retval; 248 return (error); 249 250 case F_SETOWN: 251 if (fp->f_type == DTYPE_SOCKET) { 252 ((struct socket *)fp->f_data)->so_pgid = 253 (long)SCARG(uap, arg); 254 return (0); 255 } 256 if ((long)SCARG(uap, arg) <= 0) { 257 SCARG(uap, arg) = (void *)(-(long)SCARG(uap, arg)); 258 } else { 259 struct proc *p1 = pfind((long)SCARG(uap, arg)); 260 if (p1 == 0) 261 return (ESRCH); 262 SCARG(uap, arg) = (void *)(long)p1->p_pgrp->pg_id; 263 } 264 return ((*fp->f_ops->fo_ioctl) 265 (fp, (int)TIOCSPGRP, (caddr_t)&SCARG(uap, arg), p)); 266 267 case F_SETLKW: 268 flg |= F_WAIT; 269 /* Fall into F_SETLK */ 270 271 case F_SETLK: 272 if (fp->f_type != DTYPE_VNODE) 273 return (EBADF); 274 vp = (struct vnode *)fp->f_data; 275 /* Copy in the lock structure */ 276 error = copyin((caddr_t)SCARG(uap, arg), (caddr_t)&fl, 277 sizeof (fl)); 278 if (error) 279 return (error); 280 if (fl.l_whence == SEEK_CUR) 281 fl.l_start += fp->f_offset; 282 switch (fl.l_type) { 283 284 case F_RDLCK: 285 if ((fp->f_flag & FREAD) == 0) 286 return (EBADF); 287 p->p_flag |= P_ADVLOCK; 288 return (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &fl, flg)); 289 290 case F_WRLCK: 291 if ((fp->f_flag & FWRITE) == 0) 292 return (EBADF); 293 p->p_flag |= P_ADVLOCK; 294 return (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &fl, flg)); 295 296 case F_UNLCK: 297 return (VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &fl, 298 F_POSIX)); 299 300 default: 301 return (EINVAL); 302 } 303 304 case F_GETLK: 305 if (fp->f_type != DTYPE_VNODE) 306 return (EBADF); 307 vp = (struct vnode *)fp->f_data; 308 /* Copy in the lock structure */ 309 error = copyin((caddr_t)SCARG(uap, arg), (caddr_t)&fl, 310 sizeof (fl)); 311 if (error) 312 return (error); 313 if (fl.l_whence == SEEK_CUR) 314 fl.l_start += fp->f_offset; 315 if (error = VOP_ADVLOCK(vp, (caddr_t)p, F_GETLK, &fl, F_POSIX)) 316 return (error); 317 return (copyout((caddr_t)&fl, (caddr_t)SCARG(uap, arg), 318 sizeof (fl))); 319 320 default: 321 return (EINVAL); 322 } 323 /* NOTREACHED */ 324 } 325 326 /* 327 * Common code for dup, dup2, and fcntl(F_DUPFD). 328 */ 329 int 330 finishdup(fdp, old, new, retval) 331 register struct filedesc *fdp; 332 register int old, new; 333 register_t *retval; 334 { 335 register struct file *fp; 336 337 fp = fdp->fd_ofiles[old]; 338 fdp->fd_ofiles[new] = fp; 339 fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] &~ UF_EXCLOSE; 340 fp->f_count++; 341 fd_used(fdp, new); 342 *retval = new; 343 return (0); 344 } 345 346 int 347 fdclose(p, fd) 348 struct proc *p; 349 int fd; 350 { 351 register struct filedesc *fdp = p->p_fd; 352 register struct file **fpp, *fp; 353 register char *pf; 354 355 fpp = &fdp->fd_ofiles[fd]; 356 fp = *fpp; 357 if (fp == NULL) 358 return (EBADF); 359 pf = &fdp->fd_ofileflags[fd]; 360 if (*pf & UF_MAPPED) 361 (void) munmapfd(p, fd); 362 *fpp = NULL; 363 *pf = 0; 364 fd_unused(fdp, fd); 365 return (closef(fp, p)); 366 } 367 368 /* 369 * Close a file descriptor. 370 */ 371 /* ARGSUSED */ 372 close(p, uap, retval) 373 struct proc *p; 374 struct close_args /* { 375 syscallarg(int) fd; 376 } */ *uap; 377 register_t *retval; 378 { 379 int fd = SCARG(uap, fd); 380 register struct filedesc *fdp = p->p_fd; 381 382 if ((u_int)fd >= fdp->fd_nfiles) 383 return (EBADF); 384 return (fdclose(p, fd)); 385 } 386 387 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) || defined(COMPAT_IBCS2) 388 /* 389 * Return status information about a file descriptor. 390 */ 391 /* ARGSUSED */ 392 compat_43_fstat(p, uap, retval) 393 struct proc *p; 394 register struct compat_43_fstat_args /* { 395 syscallarg(int) fd; 396 syscallarg(struct ostat *) sb; 397 } */ *uap; 398 register_t *retval; 399 { 400 int fd = SCARG(uap, fd); 401 register struct filedesc *fdp = p->p_fd; 402 register struct file *fp; 403 struct stat ub; 404 struct ostat oub; 405 int error; 406 407 if ((u_int)fd >= fdp->fd_nfiles || 408 (fp = fdp->fd_ofiles[fd]) == NULL) 409 return (EBADF); 410 switch (fp->f_type) { 411 412 case DTYPE_VNODE: 413 error = vn_stat((struct vnode *)fp->f_data, &ub, p); 414 break; 415 416 case DTYPE_SOCKET: 417 error = soo_stat((struct socket *)fp->f_data, &ub); 418 break; 419 420 default: 421 panic("ofstat"); 422 /*NOTREACHED*/ 423 } 424 cvtstat(&ub, &oub); 425 if (error == 0) 426 error = copyout((caddr_t)&oub, (caddr_t)SCARG(uap, sb), 427 sizeof (oub)); 428 return (error); 429 } 430 #endif /* COMPAT_43 || COMPAT_SUNOS || COMPAT_IBCS2 */ 431 432 /* 433 * Return status information about a file descriptor. 434 */ 435 /* ARGSUSED */ 436 fstat(p, uap, retval) 437 struct proc *p; 438 register struct fstat_args /* { 439 syscallarg(int) fd; 440 syscallarg(struct stat *) sb; 441 } */ *uap; 442 register_t *retval; 443 { 444 int fd = SCARG(uap, fd); 445 register struct filedesc *fdp = p->p_fd; 446 register struct file *fp; 447 struct stat ub; 448 int error; 449 450 if ((u_int)fd >= fdp->fd_nfiles || 451 (fp = fdp->fd_ofiles[fd]) == NULL) 452 return (EBADF); 453 switch (fp->f_type) { 454 455 case DTYPE_VNODE: 456 error = vn_stat((struct vnode *)fp->f_data, &ub, p); 457 break; 458 459 case DTYPE_SOCKET: 460 error = soo_stat((struct socket *)fp->f_data, &ub); 461 break; 462 463 default: 464 panic("fstat"); 465 /*NOTREACHED*/ 466 } 467 if (error == 0) 468 error = copyout((caddr_t)&ub, (caddr_t)SCARG(uap, sb), 469 sizeof (ub)); 470 return (error); 471 } 472 473 /* 474 * Return pathconf information about a file descriptor. 475 */ 476 /* ARGSUSED */ 477 fpathconf(p, uap, retval) 478 struct proc *p; 479 register struct fpathconf_args /* { 480 syscallarg(int) fd; 481 syscallarg(int) name; 482 } */ *uap; 483 register_t *retval; 484 { 485 int fd = SCARG(uap, fd); 486 struct filedesc *fdp = p->p_fd; 487 struct file *fp; 488 struct vnode *vp; 489 490 if ((u_int)fd >= fdp->fd_nfiles || 491 (fp = fdp->fd_ofiles[fd]) == NULL) 492 return (EBADF); 493 switch (fp->f_type) { 494 495 case DTYPE_SOCKET: 496 if (SCARG(uap, name) != _PC_PIPE_BUF) 497 return (EINVAL); 498 *retval = PIPE_BUF; 499 return (0); 500 501 case DTYPE_VNODE: 502 vp = (struct vnode *)fp->f_data; 503 #ifdef notyet 504 return (VOP_PATHCONF(vp, SCARG(uap, name), retval)); 505 #else 506 return (ENOSYS); 507 #endif 508 509 default: 510 panic("fpathconf"); 511 } 512 /*NOTREACHED*/ 513 } 514 515 /* 516 * Allocate a file descriptor for the process. 517 */ 518 int fdexpand; 519 520 fdalloc(p, want, result) 521 struct proc *p; 522 int want; 523 int *result; 524 { 525 register struct filedesc *fdp = p->p_fd; 526 register int i; 527 int lim, last, nfiles; 528 struct file **newofile; 529 char *newofileflags; 530 531 /* 532 * Search for a free descriptor starting at the higher 533 * of want or fd_freefile. If that fails, consider 534 * expanding the ofile array. 535 */ 536 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles); 537 for (;;) { 538 last = min(fdp->fd_nfiles, lim); 539 if ((i = want) < fdp->fd_freefile) 540 i = fdp->fd_freefile; 541 for (; i < last; i++) { 542 if (fdp->fd_ofiles[i] == NULL) { 543 fd_used(fdp, i); 544 if (want <= fdp->fd_freefile) 545 fdp->fd_freefile = i; 546 *result = i; 547 return (0); 548 } 549 } 550 551 /* 552 * No space in current array. Expand? 553 */ 554 if (fdp->fd_nfiles >= lim) 555 return (EMFILE); 556 if (fdp->fd_nfiles < NDEXTENT) 557 nfiles = NDEXTENT; 558 else 559 nfiles = 2 * fdp->fd_nfiles; 560 MALLOC(newofile, struct file **, nfiles * OFILESIZE, 561 M_FILEDESC, M_WAITOK); 562 newofileflags = (char *) &newofile[nfiles]; 563 /* 564 * Copy the existing ofile and ofileflags arrays 565 * and zero the new portion of each array. 566 */ 567 bcopy(fdp->fd_ofiles, newofile, 568 (i = sizeof(struct file *) * fdp->fd_nfiles)); 569 bzero((char *)newofile + i, nfiles * sizeof(struct file *) - i); 570 bcopy(fdp->fd_ofileflags, newofileflags, 571 (i = sizeof(char) * fdp->fd_nfiles)); 572 bzero(newofileflags + i, nfiles * sizeof(char) - i); 573 if (fdp->fd_nfiles > NDFILE) 574 FREE(fdp->fd_ofiles, M_FILEDESC); 575 fdp->fd_ofiles = newofile; 576 fdp->fd_ofileflags = newofileflags; 577 fdp->fd_nfiles = nfiles; 578 fdexpand++; 579 } 580 } 581 582 /* 583 * Check to see whether n user file descriptors 584 * are available to the process p. 585 */ 586 fdavail(p, n) 587 struct proc *p; 588 register int n; 589 { 590 register struct filedesc *fdp = p->p_fd; 591 register struct file **fpp; 592 register int i, lim; 593 594 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles); 595 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) 596 return (1); 597 fpp = &fdp->fd_ofiles[fdp->fd_freefile]; 598 for (i = fdp->fd_nfiles - fdp->fd_freefile; --i >= 0; fpp++) 599 if (*fpp == NULL && --n <= 0) 600 return (1); 601 return (0); 602 } 603 604 /* 605 * Create a new open file structure and allocate 606 * a file decriptor for the process that refers to it. 607 */ 608 falloc(p, resultfp, resultfd) 609 register struct proc *p; 610 struct file **resultfp; 611 int *resultfd; 612 { 613 register struct file *fp, *fq; 614 int error, i; 615 616 if (error = fdalloc(p, 0, &i)) 617 return (error); 618 if (nfiles >= maxfiles) { 619 tablefull("file"); 620 return (ENFILE); 621 } 622 /* 623 * Allocate a new file descriptor. 624 * If the process has file descriptor zero open, add to the list 625 * of open files at that point, otherwise put it at the front of 626 * the list of open files. 627 */ 628 nfiles++; 629 MALLOC(fp, struct file *, sizeof(struct file), M_FILE, M_WAITOK); 630 bzero(fp, sizeof(struct file)); 631 if (fq = p->p_fd->fd_ofiles[0]) { 632 LIST_INSERT_AFTER(fq, fp, f_list); 633 } else { 634 LIST_INSERT_HEAD(&filehead, fp, f_list); 635 } 636 p->p_fd->fd_ofiles[i] = fp; 637 fp->f_count = 1; 638 fp->f_cred = p->p_ucred; 639 crhold(fp->f_cred); 640 if (resultfp) 641 *resultfp = fp; 642 if (resultfd) 643 *resultfd = i; 644 return (0); 645 } 646 647 /* 648 * Free a file descriptor. 649 */ 650 ffree(fp) 651 register struct file *fp; 652 { 653 register struct file *fq; 654 655 LIST_REMOVE(fp, f_list); 656 crfree(fp->f_cred); 657 #ifdef DIAGNOSTIC 658 fp->f_count = 0; 659 #endif 660 nfiles--; 661 FREE(fp, M_FILE); 662 } 663 664 /* 665 * Copy a filedesc structure. 666 */ 667 struct filedesc * 668 fdcopy(p) 669 struct proc *p; 670 { 671 register struct filedesc *newfdp, *fdp = p->p_fd; 672 register struct file **fpp; 673 register int i; 674 675 MALLOC(newfdp, struct filedesc *, sizeof(struct filedesc0), 676 M_FILEDESC, M_WAITOK); 677 bcopy(fdp, newfdp, sizeof(struct filedesc)); 678 VREF(newfdp->fd_cdir); 679 if (newfdp->fd_rdir) 680 VREF(newfdp->fd_rdir); 681 newfdp->fd_refcnt = 1; 682 683 /* 684 * If the number of open files fits in the internal arrays 685 * of the open file structure, use them, otherwise allocate 686 * additional memory for the number of descriptors currently 687 * in use. 688 */ 689 if (newfdp->fd_lastfile < NDFILE) { 690 newfdp->fd_ofiles = ((struct filedesc0 *) newfdp)->fd_dfiles; 691 newfdp->fd_ofileflags = 692 ((struct filedesc0 *) newfdp)->fd_dfileflags; 693 i = NDFILE; 694 } else { 695 /* 696 * Compute the smallest multiple of NDEXTENT needed 697 * for the file descriptors currently in use, 698 * allowing the table to shrink. 699 */ 700 i = newfdp->fd_nfiles; 701 while (i >= 2 * NDEXTENT && i > newfdp->fd_lastfile * 2) 702 i /= 2; 703 MALLOC(newfdp->fd_ofiles, struct file **, i * OFILESIZE, 704 M_FILEDESC, M_WAITOK); 705 newfdp->fd_ofileflags = (char *) &newfdp->fd_ofiles[i]; 706 } 707 newfdp->fd_nfiles = i; 708 bcopy(fdp->fd_ofiles, newfdp->fd_ofiles, i * sizeof(struct file **)); 709 bcopy(fdp->fd_ofileflags, newfdp->fd_ofileflags, i * sizeof(char)); 710 fpp = newfdp->fd_ofiles; 711 for (i = newfdp->fd_lastfile; i >= 0; i--, fpp++) 712 if (*fpp != NULL) 713 (*fpp)->f_count++; 714 return (newfdp); 715 } 716 717 /* 718 * Release a filedesc structure. 719 */ 720 void 721 fdfree(p) 722 struct proc *p; 723 { 724 register struct filedesc *fdp = p->p_fd; 725 struct file **fpp; 726 register int i; 727 728 if (--fdp->fd_refcnt > 0) 729 return; 730 fpp = fdp->fd_ofiles; 731 for (i = fdp->fd_lastfile; i >= 0; i--, fpp++) 732 if (*fpp != NULL) 733 (void) closef(*fpp, p); 734 if (fdp->fd_nfiles > NDFILE) 735 FREE(fdp->fd_ofiles, M_FILEDESC); 736 vrele(fdp->fd_cdir); 737 if (fdp->fd_rdir) 738 vrele(fdp->fd_rdir); 739 FREE(fdp, M_FILEDESC); 740 } 741 742 /* 743 * Internal form of close. 744 * Decrement reference count on file structure. 745 * Note: p may be NULL when closing a file 746 * that was being passed in a message. 747 */ 748 closef(fp, p) 749 register struct file *fp; 750 register struct proc *p; 751 { 752 struct vnode *vp; 753 struct flock lf; 754 int error; 755 756 if (fp == NULL) 757 return (0); 758 /* 759 * POSIX record locking dictates that any close releases ALL 760 * locks owned by this process. This is handled by setting 761 * a flag in the unlock to free ONLY locks obeying POSIX 762 * semantics, and not to free BSD-style file locks. 763 * If the descriptor was in a message, POSIX-style locks 764 * aren't passed with the descriptor. 765 */ 766 if (p && (p->p_flag & P_ADVLOCK) && fp->f_type == DTYPE_VNODE) { 767 lf.l_whence = SEEK_SET; 768 lf.l_start = 0; 769 lf.l_len = 0; 770 lf.l_type = F_UNLCK; 771 vp = (struct vnode *)fp->f_data; 772 (void) VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_POSIX); 773 } 774 if (--fp->f_count > 0) 775 return (0); 776 if (fp->f_count < 0) 777 panic("closef: count < 0"); 778 if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE) { 779 lf.l_whence = SEEK_SET; 780 lf.l_start = 0; 781 lf.l_len = 0; 782 lf.l_type = F_UNLCK; 783 vp = (struct vnode *)fp->f_data; 784 (void) VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 785 } 786 if (fp->f_ops) 787 error = (*fp->f_ops->fo_close)(fp, p); 788 else 789 error = 0; 790 ffree(fp); 791 return (error); 792 } 793 794 /* 795 * Apply an advisory lock on a file descriptor. 796 * 797 * Just attempt to get a record lock of the requested type on 798 * the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0). 799 */ 800 /* ARGSUSED */ 801 flock(p, uap, retval) 802 struct proc *p; 803 register struct flock_args /* { 804 syscallarg(int) fd; 805 syscallarg(int) how; 806 } */ *uap; 807 register_t *retval; 808 { 809 int fd = SCARG(uap, fd); 810 int how = SCARG(uap, how); 811 register struct filedesc *fdp = p->p_fd; 812 register struct file *fp; 813 struct vnode *vp; 814 struct flock lf; 815 816 if ((u_int)fd >= fdp->fd_nfiles || 817 (fp = fdp->fd_ofiles[fd]) == NULL) 818 return (EBADF); 819 if (fp->f_type != DTYPE_VNODE) 820 return (EOPNOTSUPP); 821 vp = (struct vnode *)fp->f_data; 822 lf.l_whence = SEEK_SET; 823 lf.l_start = 0; 824 lf.l_len = 0; 825 if (how & LOCK_UN) { 826 lf.l_type = F_UNLCK; 827 fp->f_flag &= ~FHASLOCK; 828 return (VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK)); 829 } 830 if (how & LOCK_EX) 831 lf.l_type = F_WRLCK; 832 else if (how & LOCK_SH) 833 lf.l_type = F_RDLCK; 834 else 835 return (EBADF); 836 fp->f_flag |= FHASLOCK; 837 if (how & LOCK_NB) 838 return (VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK)); 839 return (VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK|F_WAIT)); 840 } 841 842 /* 843 * File Descriptor pseudo-device driver (/dev/fd/). 844 * 845 * Opening minor device N dup()s the file (if any) connected to file 846 * descriptor N belonging to the calling process. Note that this driver 847 * consists of only the ``open()'' routine, because all subsequent 848 * references to this file will be direct to the other driver. 849 */ 850 /* ARGSUSED */ 851 fdopen(dev, mode, type, p, fp) 852 dev_t dev; 853 int mode, type; 854 struct proc *p; 855 struct file *fp; 856 { 857 858 return (fddupopen(minor(dev), mode, p, fp)); 859 } 860 861 int 862 fddupopen(fd, mode, p, fp) 863 int fd; 864 int mode; 865 struct proc *p; 866 struct file *fp; 867 { 868 struct filedesc *fdp = p->p_fd; 869 struct file *ofp; 870 871 /* 872 * If we're not being called from open(), abort. 873 */ 874 if (p->p_dupfd >= 0) 875 return (ENODEV); 876 877 /* 878 * If the to-be-dup'd fd number is greater than the allowed number 879 * of file descriptors, or the fd to be dup'd has already been 880 * closed, reject. Note, check for new == old is necessary as 881 * falloc could allocate an already closed to-be-dup'd descriptor 882 * as the new descriptor. 883 */ 884 if ((u_int)fd >= fdp->fd_nfiles || 885 (ofp = fdp->fd_ofiles[fd]) == NULL || ofp == fp) 886 return (EBADF); 887 888 /* 889 * Check that the mode the file is being opened for is a subset of 890 * the mode of the existing descriptor. 891 */ 892 if (((mode & (FREAD|FWRITE)) | ofp->f_flag) != ofp->f_flag) 893 return (EACCES); 894 895 /* 896 * XXX Kludge: set curproc->p_dupfd to contain the value of the 897 * the file descriptor being sought for duplication. The error 898 * return ensures that the vnode for this device will be released 899 * by vn_open(). open() will detect this special error and call 900 * finishdup(). 901 */ 902 p->p_dupfd = fd; 903 return (ENODEV); 904 } 905 906 /* 907 * Duplicate the specified descriptor to a free descriptor. 908 */ 909 int 910 finishmove(fdp, old, new, retval) 911 register struct filedesc *fdp; 912 register int old, new; 913 register_t *retval; 914 { 915 916 /* 917 * Steal away the file pointer from old, and stuff it into new. 918 */ 919 fdp->fd_ofiles[new] = fdp->fd_ofiles[old]; 920 fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old]; 921 fdp->fd_ofiles[old] = NULL; 922 fdp->fd_ofileflags[old] = 0; 923 /* 924 * Complete the clean up of the filedesc structure by 925 * recomputing the various hints. 926 */ 927 fd_used(fdp, new); 928 fd_unused(fdp, old); 929 *retval = new; 930 return (0); 931 } 932 933 /* 934 * Close any files on exec? 935 */ 936 void 937 fdcloseexec(p) 938 struct proc *p; 939 { 940 register struct filedesc *fdp = p->p_fd; 941 register int fd; 942 943 for (fd = 0; fd <= fdp->fd_lastfile; fd++) 944 if (fdp->fd_ofileflags[fd] & UF_EXCLOSE) 945 (void) fdclose(p, fd); 946 } 947
Indexes created Sun Sep 21 14:09:52 GMT 2025