1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 39 * $Id: kern_descrip.c,v 1.39 1997/08/26 00:09:44 bde Exp $ 40 */ 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/sysproto.h> 45 #include <sys/conf.h> 46 #include <sys/filedesc.h> 47 #include <sys/kernel.h> 48 #include <sys/sysctl.h> 49 #include <sys/vnode.h> 50 #include <sys/proc.h> 51 #include <sys/file.h> 52 #include <sys/socketvar.h> 53 #include <sys/stat.h> 54 #include <sys/filio.h> 55 #include <sys/ttycom.h> 56 #include <sys/fcntl.h> 57 #include <sys/malloc.h> 58 #include <sys/unistd.h> 59 #include <sys/resourcevar.h> 60 #include <sys/pipe.h> 61 62 #include <vm/vm.h> 63 #include <vm/vm_extern.h> 64 65 #ifdef DEVFS 66 #include <sys/devfsext.h> 67 #endif /*DEVFS*/ 68 69 static d_open_t fdopen; 70 #define NUMFDESC 64 71 72 #define CDEV_MAJOR 22 73 static struct cdevsw fildesc_cdevsw = 74 { fdopen, noclose, noread, nowrite, 75 noioc, nostop, nullreset, nodevtotty, 76 seltrue, nommap, nostrat }; 77 78 static int finishdup __P((struct filedesc *fdp, int old, int new, int *retval)); 79 /* 80 * Descriptor management. 81 */ 82 struct filelist filehead; /* head of list of open files */ 83 int nfiles; /* actual number of open files */ 84 extern int cmask; 85 86 /* 87 * System calls on descriptors. 88 */ 89 #ifndef _SYS_SYSPROTO_H_ 90 struct getdtablesize_args { 91 int dummy; 92 }; 93 #endif 94 /* ARGSUSED */ 95 int 96 getdtablesize(p, uap, retval) 97 struct proc *p; 98 struct getdtablesize_args *uap; 99 int *retval; 100 { 101 102 *retval = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc); 103 return (0); 104 } 105 106 /* 107 * Duplicate a file descriptor to a particular value. 108 */ 109 #ifndef _SYS_SYSPROTO_H_ 110 struct dup2_args { 111 u_int from; 112 u_int to; 113 }; 114 #endif 115 /* ARGSUSED */ 116 int 117 dup2(p, uap, retval) 118 struct proc *p; 119 struct dup2_args *uap; 120 int *retval; 121 { 122 register struct filedesc *fdp = p->p_fd; 123 register u_int old = uap->from, new = uap->to; 124 int i, error; 125 126 if (old >= fdp->fd_nfiles || 127 fdp->fd_ofiles[old] == NULL || 128 new >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur || 129 new >= maxfilesperproc) 130 return (EBADF); 131 if (old == new) { 132 *retval = new; 133 return (0); 134 } 135 if (new >= fdp->fd_nfiles) { 136 if ((error = fdalloc(p, new, &i))) 137 return (error); 138 if (new != i) 139 panic("dup2: fdalloc"); 140 } else if (fdp->fd_ofiles[new]) { 141 if (fdp->fd_ofileflags[new] & UF_MAPPED) 142 (void) munmapfd(p, new); 143 /* 144 * dup2() must succeed even if the close has an error. 145 */ 146 (void) closef(fdp->fd_ofiles[new], p); 147 } 148 return (finishdup(fdp, (int)old, (int)new, retval)); 149 } 150 151 /* 152 * Duplicate a file descriptor. 153 */ 154 #ifndef _SYS_SYSPROTO_H_ 155 struct dup_args { 156 u_int fd; 157 }; 158 #endif 159 /* ARGSUSED */ 160 int 161 dup(p, uap, retval) 162 struct proc *p; 163 struct dup_args *uap; 164 int *retval; 165 { 166 register struct filedesc *fdp; 167 u_int old; 168 int new, error; 169 170 old = uap->fd; 171 172 #if 0 173 /* 174 * XXX Compatibility 175 */ 176 if (old &~ 077) { uap->fd &= 077; return (dup2(p, uap, retval)); } 177 #endif 178 179 fdp = p->p_fd; 180 if (old >= fdp->fd_nfiles || fdp->fd_ofiles[old] == NULL) 181 return (EBADF); 182 if ((error = fdalloc(p, 0, &new))) 183 return (error); 184 return (finishdup(fdp, (int)old, new, retval)); 185 } 186 187 /* 188 * The file control system call. 189 */ 190 #ifndef _SYS_SYSPROTO_H_ 191 struct fcntl_args { 192 int fd; 193 int cmd; 194 int arg; 195 }; 196 #endif 197 /* ARGSUSED */ 198 int 199 fcntl(p, uap, retval) 200 struct proc *p; 201 register struct fcntl_args *uap; 202 int *retval; 203 { 204 register struct filedesc *fdp = p->p_fd; 205 register struct file *fp; 206 register char *pop; 207 struct vnode *vp; 208 int i, tmp, error, flg = F_POSIX; 209 struct flock fl; 210 u_int newmin; 211 212 if ((unsigned)uap->fd >= fdp->fd_nfiles || 213 (fp = fdp->fd_ofiles[uap->fd]) == NULL) 214 return (EBADF); 215 pop = &fdp->fd_ofileflags[uap->fd]; 216 switch (uap->cmd) { 217 218 case F_DUPFD: 219 newmin = uap->arg; 220 if (newmin >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur || 221 newmin >= maxfilesperproc) 222 return (EINVAL); 223 if ((error = fdalloc(p, newmin, &i))) 224 return (error); 225 return (finishdup(fdp, uap->fd, i, retval)); 226 227 case F_GETFD: 228 *retval = *pop & 1; 229 return (0); 230 231 case F_SETFD: 232 *pop = (*pop &~ 1) | (uap->arg & 1); 233 return (0); 234 235 case F_GETFL: 236 *retval = OFLAGS(fp->f_flag); 237 return (0); 238 239 case F_SETFL: 240 fp->f_flag &= ~FCNTLFLAGS; 241 fp->f_flag |= FFLAGS(uap->arg) & FCNTLFLAGS; 242 tmp = fp->f_flag & FNONBLOCK; 243 error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p); 244 if (error) 245 return (error); 246 tmp = fp->f_flag & FASYNC; 247 error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, (caddr_t)&tmp, p); 248 if (!error) 249 return (0); 250 fp->f_flag &= ~FNONBLOCK; 251 tmp = 0; 252 (void) (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p); 253 return (error); 254 255 case F_GETOWN: 256 if (fp->f_type == DTYPE_SOCKET) { 257 *retval = ((struct socket *)fp->f_data)->so_pgid; 258 return (0); 259 } 260 error = (*fp->f_ops->fo_ioctl) 261 (fp, TIOCGPGRP, (caddr_t)retval, p); 262 *retval = -*retval; 263 return (error); 264 265 case F_SETOWN: 266 if (fp->f_type == DTYPE_SOCKET) { 267 ((struct socket *)fp->f_data)->so_pgid = uap->arg; 268 return (0); 269 } 270 if (uap->arg <= 0) { 271 uap->arg = -uap->arg; 272 } else { 273 struct proc *p1 = pfind(uap->arg); 274 if (p1 == 0) 275 return (ESRCH); 276 uap->arg = p1->p_pgrp->pg_id; 277 } 278 return ((*fp->f_ops->fo_ioctl) 279 (fp, TIOCSPGRP, (caddr_t)&uap->arg, p)); 280 281 case F_SETLKW: 282 flg |= F_WAIT; 283 /* Fall into F_SETLK */ 284 285 case F_SETLK: 286 if (fp->f_type != DTYPE_VNODE) 287 return (EBADF); 288 vp = (struct vnode *)fp->f_data; 289 /* Copy in the lock structure */ 290 error = copyin((caddr_t)uap->arg, (caddr_t)&fl, sizeof (fl)); 291 if (error) 292 return (error); 293 if (fl.l_whence == SEEK_CUR) 294 fl.l_start += fp->f_offset; 295 switch (fl.l_type) { 296 297 case F_RDLCK: 298 if ((fp->f_flag & FREAD) == 0) 299 return (EBADF); 300 p->p_flag |= P_ADVLOCK; 301 return (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &fl, flg)); 302 303 case F_WRLCK: 304 if ((fp->f_flag & FWRITE) == 0) 305 return (EBADF); 306 p->p_flag |= P_ADVLOCK; 307 return (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &fl, flg)); 308 309 case F_UNLCK: 310 return (VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &fl, 311 F_POSIX)); 312 313 default: 314 return (EINVAL); 315 } 316 317 case F_GETLK: 318 if (fp->f_type != DTYPE_VNODE) 319 return (EBADF); 320 vp = (struct vnode *)fp->f_data; 321 /* Copy in the lock structure */ 322 error = copyin((caddr_t)uap->arg, (caddr_t)&fl, sizeof (fl)); 323 if (error) 324 return (error); 325 if (fl.l_type != F_RDLCK && fl.l_type != F_WRLCK && 326 fl.l_type != F_UNLCK) 327 return (EINVAL); 328 if (fl.l_whence == SEEK_CUR) 329 fl.l_start += fp->f_offset; 330 if ((error = VOP_ADVLOCK(vp,(caddr_t)p,F_GETLK,&fl,F_POSIX))) 331 return (error); 332 return (copyout((caddr_t)&fl, (caddr_t)uap->arg, sizeof (fl))); 333 334 default: 335 return (EINVAL); 336 } 337 /* NOTREACHED */ 338 } 339 340 /* 341 * Common code for dup, dup2, and fcntl(F_DUPFD). 342 */ 343 static int 344 finishdup(fdp, old, new, retval) 345 register struct filedesc *fdp; 346 register int old, new, *retval; 347 { 348 register struct file *fp; 349 350 fp = fdp->fd_ofiles[old]; 351 fdp->fd_ofiles[new] = fp; 352 fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] &~ UF_EXCLOSE; 353 fp->f_count++; 354 if (new > fdp->fd_lastfile) 355 fdp->fd_lastfile = new; 356 *retval = new; 357 return (0); 358 } 359 360 /* 361 * Close a file descriptor. 362 */ 363 #ifndef _SYS_SYSPROTO_H_ 364 struct close_args { 365 int fd; 366 }; 367 #endif 368 /* ARGSUSED */ 369 int 370 close(p, uap, retval) 371 struct proc *p; 372 struct close_args *uap; 373 int *retval; 374 { 375 register struct filedesc *fdp = p->p_fd; 376 register struct file *fp; 377 register int fd = uap->fd; 378 register u_char *pf; 379 380 if ((unsigned)fd >= fdp->fd_nfiles || 381 (fp = fdp->fd_ofiles[fd]) == NULL) 382 return (EBADF); 383 pf = (u_char *)&fdp->fd_ofileflags[fd]; 384 if (*pf & UF_MAPPED) 385 (void) munmapfd(p, fd); 386 fdp->fd_ofiles[fd] = NULL; 387 while (fdp->fd_lastfile > 0 && fdp->fd_ofiles[fdp->fd_lastfile] == NULL) 388 fdp->fd_lastfile--; 389 if (fd < fdp->fd_freefile) 390 fdp->fd_freefile = fd; 391 *pf = 0; 392 return (closef(fp, p)); 393 } 394 395 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 396 /* 397 * Return status information about a file descriptor. 398 */ 399 #ifndef _SYS_SYSPROTO_H_ 400 struct ofstat_args { 401 int fd; 402 struct ostat *sb; 403 }; 404 #endif 405 /* ARGSUSED */ 406 int 407 ofstat(p, uap, retval) 408 struct proc *p; 409 register struct ofstat_args *uap; 410 int *retval; 411 { 412 register struct filedesc *fdp = p->p_fd; 413 register struct file *fp; 414 struct stat ub; 415 struct ostat oub; 416 int error; 417 418 if ((unsigned)uap->fd >= fdp->fd_nfiles || 419 (fp = fdp->fd_ofiles[uap->fd]) == NULL) 420 return (EBADF); 421 switch (fp->f_type) { 422 423 case DTYPE_FIFO: 424 case DTYPE_VNODE: 425 error = vn_stat((struct vnode *)fp->f_data, &ub, p); 426 break; 427 428 case DTYPE_SOCKET: 429 error = soo_stat((struct socket *)fp->f_data, &ub); 430 break; 431 432 case DTYPE_PIPE: 433 error = pipe_stat((struct pipe *)fp->f_data, &ub); 434 break; 435 436 default: 437 panic("ofstat"); 438 /*NOTREACHED*/ 439 } 440 cvtstat(&ub, &oub); 441 if (error == 0) 442 error = copyout((caddr_t)&oub, (caddr_t)uap->sb, sizeof (oub)); 443 return (error); 444 } 445 #endif /* COMPAT_43 || COMPAT_SUNOS */ 446 447 /* 448 * Return status information about a file descriptor. 449 */ 450 #ifndef _SYS_SYSPROTO_H_ 451 struct fstat_args { 452 int fd; 453 struct stat *sb; 454 }; 455 #endif 456 /* ARGSUSED */ 457 int 458 fstat(p, uap, retval) 459 struct proc *p; 460 register struct fstat_args *uap; 461 int *retval; 462 { 463 register struct filedesc *fdp = p->p_fd; 464 register struct file *fp; 465 struct stat ub; 466 int error; 467 468 if ((unsigned)uap->fd >= fdp->fd_nfiles || 469 (fp = fdp->fd_ofiles[uap->fd]) == NULL) 470 return (EBADF); 471 switch (fp->f_type) { 472 473 case DTYPE_FIFO: 474 case DTYPE_VNODE: 475 error = vn_stat((struct vnode *)fp->f_data, &ub, p); 476 break; 477 478 case DTYPE_SOCKET: 479 error = soo_stat((struct socket *)fp->f_data, &ub); 480 break; 481 482 case DTYPE_PIPE: 483 error = pipe_stat((struct pipe *)fp->f_data, &ub); 484 break; 485 486 default: 487 panic("fstat"); 488 /*NOTREACHED*/ 489 } 490 if (error == 0) 491 error = copyout((caddr_t)&ub, (caddr_t)uap->sb, sizeof (ub)); 492 return (error); 493 } 494 495 /* 496 * Return pathconf information about a file descriptor. 497 */ 498 #ifndef _SYS_SYSPROTO_H_ 499 struct fpathconf_args { 500 int fd; 501 int name; 502 }; 503 #endif 504 /* ARGSUSED */ 505 int 506 fpathconf(p, uap, retval) 507 struct proc *p; 508 register struct fpathconf_args *uap; 509 int *retval; 510 { 511 struct filedesc *fdp = p->p_fd; 512 struct file *fp; 513 struct vnode *vp; 514 515 if ((unsigned)uap->fd >= fdp->fd_nfiles || 516 (fp = fdp->fd_ofiles[uap->fd]) == NULL) 517 return (EBADF); 518 switch (fp->f_type) { 519 520 case DTYPE_PIPE: 521 case DTYPE_SOCKET: 522 if (uap->name != _PC_PIPE_BUF) 523 return (EINVAL); 524 *retval = PIPE_BUF; 525 return (0); 526 527 case DTYPE_FIFO: 528 case DTYPE_VNODE: 529 vp = (struct vnode *)fp->f_data; 530 return (VOP_PATHCONF(vp, uap->name, retval)); 531 532 default: 533 panic("fpathconf"); 534 } 535 /*NOTREACHED*/ 536 } 537 538 /* 539 * Allocate a file descriptor for the process. 540 */ 541 static int fdexpand; 542 SYSCTL_INT(_debug, OID_AUTO, fdexpand, CTLFLAG_RD, &fdexpand, 0, ""); 543 544 int 545 fdalloc(p, want, result) 546 struct proc *p; 547 int want; 548 int *result; 549 { 550 register struct filedesc *fdp = p->p_fd; 551 register int i; 552 int lim, last, nfiles; 553 struct file **newofile; 554 char *newofileflags; 555 556 /* 557 * Search for a free descriptor starting at the higher 558 * of want or fd_freefile. If that fails, consider 559 * expanding the ofile array. 560 */ 561 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc); 562 for (;;) { 563 last = min(fdp->fd_nfiles, lim); 564 if ((i = want) < fdp->fd_freefile) 565 i = fdp->fd_freefile; 566 for (; i < last; i++) { 567 if (fdp->fd_ofiles[i] == NULL) { 568 fdp->fd_ofileflags[i] = 0; 569 if (i > fdp->fd_lastfile) 570 fdp->fd_lastfile = i; 571 if (want <= fdp->fd_freefile) 572 fdp->fd_freefile = i; 573 *result = i; 574 return (0); 575 } 576 } 577 578 /* 579 * No space in current array. Expand? 580 */ 581 if (fdp->fd_nfiles >= lim) 582 return (EMFILE); 583 if (fdp->fd_nfiles < NDEXTENT) 584 nfiles = NDEXTENT; 585 else 586 nfiles = 2 * fdp->fd_nfiles; 587 MALLOC(newofile, struct file **, nfiles * OFILESIZE, 588 M_FILEDESC, M_WAITOK); 589 newofileflags = (char *) &newofile[nfiles]; 590 /* 591 * Copy the existing ofile and ofileflags arrays 592 * and zero the new portion of each array. 593 */ 594 bcopy(fdp->fd_ofiles, newofile, 595 (i = sizeof(struct file *) * fdp->fd_nfiles)); 596 bzero((char *)newofile + i, nfiles * sizeof(struct file *) - i); 597 bcopy(fdp->fd_ofileflags, newofileflags, 598 (i = sizeof(char) * fdp->fd_nfiles)); 599 bzero(newofileflags + i, nfiles * sizeof(char) - i); 600 if (fdp->fd_nfiles > NDFILE) 601 FREE(fdp->fd_ofiles, M_FILEDESC); 602 fdp->fd_ofiles = newofile; 603 fdp->fd_ofileflags = newofileflags; 604 fdp->fd_nfiles = nfiles; 605 fdexpand++; 606 } 607 return (0); 608 } 609 610 /* 611 * Check to see whether n user file descriptors 612 * are available to the process p. 613 */ 614 int 615 fdavail(p, n) 616 struct proc *p; 617 register int n; 618 { 619 register struct filedesc *fdp = p->p_fd; 620 register struct file **fpp; 621 register int i, lim, last; 622 623 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc); 624 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) 625 return (1); 626 627 last = min(fdp->fd_nfiles, lim); 628 fpp = &fdp->fd_ofiles[fdp->fd_freefile]; 629 for (i = last - fdp->fd_freefile; --i >= 0; fpp++) 630 if (*fpp == NULL && --n <= 0) 631 return (1); 632 return (0); 633 } 634 635 /* 636 * Create a new open file structure and allocate 637 * a file decriptor for the process that refers to it. 638 */ 639 int 640 falloc(p, resultfp, resultfd) 641 register struct proc *p; 642 struct file **resultfp; 643 int *resultfd; 644 { 645 register struct file *fp, *fq; 646 int error, i; 647 648 if ((error = fdalloc(p, 0, &i))) 649 return (error); 650 if (nfiles >= maxfiles) { 651 tablefull("file"); 652 return (ENFILE); 653 } 654 /* 655 * Allocate a new file descriptor. 656 * If the process has file descriptor zero open, add to the list 657 * of open files at that point, otherwise put it at the front of 658 * the list of open files. 659 */ 660 nfiles++; 661 MALLOC(fp, struct file *, sizeof(struct file), M_FILE, M_WAITOK); 662 bzero(fp, sizeof(struct file)); 663 if ((fq = p->p_fd->fd_ofiles[0])) { 664 LIST_INSERT_AFTER(fq, fp, f_list); 665 } else { 666 LIST_INSERT_HEAD(&filehead, fp, f_list); 667 } 668 p->p_fd->fd_ofiles[i] = fp; 669 fp->f_count = 1; 670 fp->f_cred = p->p_ucred; 671 fp->f_seqcount = 1; 672 crhold(fp->f_cred); 673 if (resultfp) 674 *resultfp = fp; 675 if (resultfd) 676 *resultfd = i; 677 return (0); 678 } 679 680 /* 681 * Free a file descriptor. 682 */ 683 void 684 ffree(fp) 685 register struct file *fp; 686 { 687 LIST_REMOVE(fp, f_list); 688 crfree(fp->f_cred); 689 #ifdef DIAGNOSTIC 690 fp->f_count = 0; 691 #endif 692 nfiles--; 693 FREE(fp, M_FILE); 694 } 695 696 /* 697 * Build a new filedesc structure. 698 */ 699 struct filedesc * 700 fdinit(p) 701 struct proc *p; 702 { 703 register struct filedesc0 *newfdp; 704 register struct filedesc *fdp = p->p_fd; 705 706 MALLOC(newfdp, struct filedesc0 *, sizeof(struct filedesc0), 707 M_FILEDESC, M_WAITOK); 708 bzero(newfdp, sizeof(struct filedesc0)); 709 newfdp->fd_fd.fd_cdir = fdp->fd_cdir; 710 VREF(newfdp->fd_fd.fd_cdir); 711 newfdp->fd_fd.fd_rdir = fdp->fd_rdir; 712 if (newfdp->fd_fd.fd_rdir) 713 VREF(newfdp->fd_fd.fd_rdir); 714 715 /* Create the file descriptor table. */ 716 newfdp->fd_fd.fd_refcnt = 1; 717 newfdp->fd_fd.fd_cmask = cmask; 718 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles; 719 newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags; 720 newfdp->fd_fd.fd_nfiles = NDFILE; 721 722 newfdp->fd_fd.fd_freefile = 0; 723 newfdp->fd_fd.fd_lastfile = 0; 724 725 return (&newfdp->fd_fd); 726 } 727 728 /* 729 * Share a filedesc structure. 730 */ 731 struct filedesc * 732 fdshare(p) 733 struct proc *p; 734 { 735 p->p_fd->fd_refcnt++; 736 return (p->p_fd); 737 } 738 739 /* 740 * Copy a filedesc structure. 741 */ 742 struct filedesc * 743 fdcopy(p) 744 struct proc *p; 745 { 746 register struct filedesc *newfdp, *fdp = p->p_fd; 747 register struct file **fpp; 748 register int i; 749 750 MALLOC(newfdp, struct filedesc *, sizeof(struct filedesc0), 751 M_FILEDESC, M_WAITOK); 752 bcopy(fdp, newfdp, sizeof(struct filedesc)); 753 VREF(newfdp->fd_cdir); 754 if (newfdp->fd_rdir) 755 VREF(newfdp->fd_rdir); 756 newfdp->fd_refcnt = 1; 757 758 /* 759 * If the number of open files fits in the internal arrays 760 * of the open file structure, use them, otherwise allocate 761 * additional memory for the number of descriptors currently 762 * in use. 763 */ 764 if (newfdp->fd_lastfile < NDFILE) { 765 newfdp->fd_ofiles = ((struct filedesc0 *) newfdp)->fd_dfiles; 766 newfdp->fd_ofileflags = 767 ((struct filedesc0 *) newfdp)->fd_dfileflags; 768 i = NDFILE; 769 } else { 770 /* 771 * Compute the smallest multiple of NDEXTENT needed 772 * for the file descriptors currently in use, 773 * allowing the table to shrink. 774 */ 775 i = newfdp->fd_nfiles; 776 while (i > 2 * NDEXTENT && i > newfdp->fd_lastfile * 2) 777 i /= 2; 778 MALLOC(newfdp->fd_ofiles, struct file **, i * OFILESIZE, 779 M_FILEDESC, M_WAITOK); 780 newfdp->fd_ofileflags = (char *) &newfdp->fd_ofiles[i]; 781 } 782 newfdp->fd_nfiles = i; 783 bcopy(fdp->fd_ofiles, newfdp->fd_ofiles, i * sizeof(struct file **)); 784 bcopy(fdp->fd_ofileflags, newfdp->fd_ofileflags, i * sizeof(char)); 785 fpp = newfdp->fd_ofiles; 786 for (i = newfdp->fd_lastfile; i-- >= 0; fpp++) 787 if (*fpp != NULL) 788 (*fpp)->f_count++; 789 return (newfdp); 790 } 791 792 /* 793 * Release a filedesc structure. 794 */ 795 void 796 fdfree(p) 797 struct proc *p; 798 { 799 register struct filedesc *fdp = p->p_fd; 800 struct file **fpp; 801 register int i; 802 803 if (--fdp->fd_refcnt > 0) 804 return; 805 fpp = fdp->fd_ofiles; 806 for (i = fdp->fd_lastfile; i-- >= 0; fpp++) 807 if (*fpp) 808 (void) closef(*fpp, p); 809 if (fdp->fd_nfiles > NDFILE) 810 FREE(fdp->fd_ofiles, M_FILEDESC); 811 vrele(fdp->fd_cdir); 812 if (fdp->fd_rdir) 813 vrele(fdp->fd_rdir); 814 FREE(fdp, M_FILEDESC); 815 } 816 817 /* 818 * Close any files on exec? 819 */ 820 void 821 fdcloseexec(p) 822 struct proc *p; 823 { 824 struct filedesc *fdp = p->p_fd; 825 struct file **fpp; 826 char *fdfp; 827 register int i; 828 829 fpp = fdp->fd_ofiles; 830 fdfp = fdp->fd_ofileflags; 831 for (i = 0; i <= fdp->fd_lastfile; i++, fpp++, fdfp++) 832 if (*fpp != NULL && (*fdfp & UF_EXCLOSE)) { 833 if (*fdfp & UF_MAPPED) 834 (void) munmapfd(p, i); 835 (void) closef(*fpp, p); 836 *fpp = NULL; 837 *fdfp = 0; 838 if (i < fdp->fd_freefile) 839 fdp->fd_freefile = i; 840 } 841 while (fdp->fd_lastfile > 0 && fdp->fd_ofiles[fdp->fd_lastfile] == NULL) 842 fdp->fd_lastfile--; 843 } 844 845 /* 846 * Internal form of close. 847 * Decrement reference count on file structure. 848 * Note: p may be NULL when closing a file 849 * that was being passed in a message. 850 */ 851 int 852 closef(fp, p) 853 register struct file *fp; 854 register struct proc *p; 855 { 856 struct vnode *vp; 857 struct flock lf; 858 int error; 859 860 if (fp == NULL) 861 return (0); 862 /* 863 * POSIX record locking dictates that any close releases ALL 864 * locks owned by this process. This is handled by setting 865 * a flag in the unlock to free ONLY locks obeying POSIX 866 * semantics, and not to free BSD-style file locks. 867 * If the descriptor was in a message, POSIX-style locks 868 * aren't passed with the descriptor. 869 */ 870 if (p && (p->p_flag & P_ADVLOCK) && fp->f_type == DTYPE_VNODE) { 871 lf.l_whence = SEEK_SET; 872 lf.l_start = 0; 873 lf.l_len = 0; 874 lf.l_type = F_UNLCK; 875 vp = (struct vnode *)fp->f_data; 876 (void) VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_POSIX); 877 } 878 if (--fp->f_count > 0) 879 return (0); 880 if (fp->f_count < 0) 881 panic("closef: count < 0"); 882 if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE) { 883 lf.l_whence = SEEK_SET; 884 lf.l_start = 0; 885 lf.l_len = 0; 886 lf.l_type = F_UNLCK; 887 vp = (struct vnode *)fp->f_data; 888 (void) VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 889 } 890 if (fp->f_ops) 891 error = (*fp->f_ops->fo_close)(fp, p); 892 else 893 error = 0; 894 ffree(fp); 895 return (error); 896 } 897 898 /* 899 * Apply an advisory lock on a file descriptor. 900 * 901 * Just attempt to get a record lock of the requested type on 902 * the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0). 903 */ 904 #ifndef _SYS_SYSPROTO_H_ 905 struct flock_args { 906 int fd; 907 int how; 908 }; 909 #endif 910 /* ARGSUSED */ 911 int 912 flock(p, uap, retval) 913 struct proc *p; 914 register struct flock_args *uap; 915 int *retval; 916 { 917 register struct filedesc *fdp = p->p_fd; 918 register struct file *fp; 919 struct vnode *vp; 920 struct flock lf; 921 922 if ((unsigned)uap->fd >= fdp->fd_nfiles || 923 (fp = fdp->fd_ofiles[uap->fd]) == NULL) 924 return (EBADF); 925 if (fp->f_type != DTYPE_VNODE) 926 return (EOPNOTSUPP); 927 vp = (struct vnode *)fp->f_data; 928 lf.l_whence = SEEK_SET; 929 lf.l_start = 0; 930 lf.l_len = 0; 931 if (uap->how & LOCK_UN) { 932 lf.l_type = F_UNLCK; 933 fp->f_flag &= ~FHASLOCK; 934 return (VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK)); 935 } 936 if (uap->how & LOCK_EX) 937 lf.l_type = F_WRLCK; 938 else if (uap->how & LOCK_SH) 939 lf.l_type = F_RDLCK; 940 else 941 return (EBADF); 942 fp->f_flag |= FHASLOCK; 943 if (uap->how & LOCK_NB) 944 return (VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK)); 945 return (VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK|F_WAIT)); 946 } 947 948 /* 949 * File Descriptor pseudo-device driver (/dev/fd/). 950 * 951 * Opening minor device N dup()s the file (if any) connected to file 952 * descriptor N belonging to the calling process. Note that this driver 953 * consists of only the ``open()'' routine, because all subsequent 954 * references to this file will be direct to the other driver. 955 */ 956 /* ARGSUSED */ 957 static int 958 fdopen(dev, mode, type, p) 959 dev_t dev; 960 int mode, type; 961 struct proc *p; 962 { 963 964 /* 965 * XXX Kludge: set curproc->p_dupfd to contain the value of the 966 * the file descriptor being sought for duplication. The error 967 * return ensures that the vnode for this device will be released 968 * by vn_open. Open will detect this special error and take the 969 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 970 * will simply report the error. 971 */ 972 p->p_dupfd = minor(dev); 973 return (ENODEV); 974 } 975 976 /* 977 * Duplicate the specified descriptor to a free descriptor. 978 */ 979 int 980 dupfdopen(fdp, indx, dfd, mode, error) 981 register struct filedesc *fdp; 982 register int indx, dfd; 983 int mode; 984 int error; 985 { 986 register struct file *wfp; 987 struct file *fp; 988 989 /* 990 * If the to-be-dup'd fd number is greater than the allowed number 991 * of file descriptors, or the fd to be dup'd has already been 992 * closed, reject. Note, check for new == old is necessary as 993 * falloc could allocate an already closed to-be-dup'd descriptor 994 * as the new descriptor. 995 */ 996 fp = fdp->fd_ofiles[indx]; 997 if ((u_int)dfd >= fdp->fd_nfiles || 998 (wfp = fdp->fd_ofiles[dfd]) == NULL || fp == wfp) 999 return (EBADF); 1000 1001 /* 1002 * There are two cases of interest here. 1003 * 1004 * For ENODEV simply dup (dfd) to file descriptor 1005 * (indx) and return. 1006 * 1007 * For ENXIO steal away the file structure from (dfd) and 1008 * store it in (indx). (dfd) is effectively closed by 1009 * this operation. 1010 * 1011 * Any other error code is just returned. 1012 */ 1013 switch (error) { 1014 case ENODEV: 1015 /* 1016 * Check that the mode the file is being opened for is a 1017 * subset of the mode of the existing descriptor. 1018 */ 1019 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) 1020 return (EACCES); 1021 fdp->fd_ofiles[indx] = wfp; 1022 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 1023 wfp->f_count++; 1024 if (indx > fdp->fd_lastfile) 1025 fdp->fd_lastfile = indx; 1026 return (0); 1027 1028 case ENXIO: 1029 /* 1030 * Steal away the file pointer from dfd, and stuff it into indx. 1031 */ 1032 fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd]; 1033 fdp->fd_ofiles[dfd] = NULL; 1034 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 1035 fdp->fd_ofileflags[dfd] = 0; 1036 /* 1037 * Complete the clean up of the filedesc structure by 1038 * recomputing the various hints. 1039 */ 1040 if (indx > fdp->fd_lastfile) 1041 fdp->fd_lastfile = indx; 1042 else 1043 while (fdp->fd_lastfile > 0 && 1044 fdp->fd_ofiles[fdp->fd_lastfile] == NULL) 1045 fdp->fd_lastfile--; 1046 if (dfd < fdp->fd_freefile) 1047 fdp->fd_freefile = dfd; 1048 return (0); 1049 1050 default: 1051 return (error); 1052 } 1053 /* NOTREACHED */ 1054 } 1055 1056 /* 1057 * Get file structures. 1058 */ 1059 static int 1060 sysctl_kern_file SYSCTL_HANDLER_ARGS 1061 { 1062 int error; 1063 struct file *fp; 1064 1065 if (!req->oldptr) { 1066 /* 1067 * overestimate by 10 files 1068 */ 1069 return (SYSCTL_OUT(req, 0, sizeof(filehead) + 1070 (nfiles + 10) * sizeof(struct file))); 1071 } 1072 1073 error = SYSCTL_OUT(req, (caddr_t)&filehead, sizeof(filehead)); 1074 if (error) 1075 return (error); 1076 1077 /* 1078 * followed by an array of file structures 1079 */ 1080 for (fp = filehead.lh_first; fp != NULL; fp = fp->f_list.le_next) { 1081 error = SYSCTL_OUT(req, (caddr_t)fp, sizeof (struct file)); 1082 if (error) 1083 return (error); 1084 } 1085 return (0); 1086 } 1087 1088 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD, 1089 0, 0, sysctl_kern_file, "S,file", ""); 1090 1091 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, 1092 CTLFLAG_RW, &maxfilesperproc, 0, ""); 1093 1094 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, &maxfiles, 0, ""); 1095 1096 static fildesc_devsw_installed = 0; 1097 #ifdef DEVFS 1098 static void *devfs_token_stdin; 1099 static void *devfs_token_stdout; 1100 static void *devfs_token_stderr; 1101 static void *devfs_token_fildesc[NUMFDESC]; 1102 #endif 1103 1104 static void fildesc_drvinit(void *unused) 1105 { 1106 dev_t dev; 1107 #ifdef DEVFS 1108 int fd; 1109 #endif 1110 1111 if( ! fildesc_devsw_installed ) { 1112 dev = makedev(CDEV_MAJOR,0); 1113 cdevsw_add(&dev,&fildesc_cdevsw,NULL); 1114 fildesc_devsw_installed = 1; 1115 #ifdef DEVFS 1116 for (fd = 0; fd < NUMFDESC; fd++) 1117 devfs_token_fildesc[fd] = 1118 devfs_add_devswf(&fildesc_cdevsw, fd, DV_CHR, 1119 UID_BIN, GID_BIN, 0666, 1120 "fd/%d", fd); 1121 devfs_token_stdin = 1122 devfs_add_devswf(&fildesc_cdevsw, 0, DV_CHR, 1123 UID_ROOT, GID_WHEEL, 0666, 1124 "stdin", fd); 1125 devfs_token_stdout = 1126 devfs_add_devswf(&fildesc_cdevsw, 1, DV_CHR, 1127 UID_ROOT, GID_WHEEL, 0666, 1128 "stdout", fd); 1129 devfs_token_stderr = 1130 devfs_add_devswf(&fildesc_cdevsw, 2, DV_CHR, 1131 UID_ROOT, GID_WHEEL, 0666, 1132 "stderr", fd); 1133 #endif 1134 } 1135 } 1136 1137 SYSINIT(fildescdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR, 1138 fildesc_drvinit,NULL) 1139 1140 1141