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 * $FreeBSD$ 40 */ 41 42 #include "opt_compat.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/lock.h> 47 #include <sys/malloc.h> 48 #include <sys/mutex.h> 49 #include <sys/sysproto.h> 50 #include <sys/conf.h> 51 #include <sys/filedesc.h> 52 #include <sys/kernel.h> 53 #include <sys/sysctl.h> 54 #include <sys/vnode.h> 55 #include <sys/proc.h> 56 #include <sys/file.h> 57 #include <sys/stat.h> 58 #include <sys/filio.h> 59 #include <sys/fcntl.h> 60 #include <sys/unistd.h> 61 #include <sys/resourcevar.h> 62 #include <sys/event.h> 63 64 #include <machine/limits.h> 65 66 #include <vm/vm.h> 67 #include <vm/vm_extern.h> 68 69 static MALLOC_DEFINE(M_FILEDESC, "file desc", "Open file descriptor table"); 70 MALLOC_DEFINE(M_FILE, "file", "Open file structure"); 71 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 72 73 static d_open_t fdopen; 74 #define NUMFDESC 64 75 76 #define CDEV_MAJOR 22 77 static struct cdevsw fildesc_cdevsw = { 78 /* open */ fdopen, 79 /* close */ noclose, 80 /* read */ noread, 81 /* write */ nowrite, 82 /* ioctl */ noioctl, 83 /* poll */ nopoll, 84 /* mmap */ nommap, 85 /* strategy */ nostrategy, 86 /* name */ "FD", 87 /* maj */ CDEV_MAJOR, 88 /* dump */ nodump, 89 /* psize */ nopsize, 90 /* flags */ 0, 91 }; 92 93 static int do_dup __P((struct filedesc *fdp, int old, int new, register_t *retval, struct thread *td)); 94 static int badfo_readwrite __P((struct file *fp, struct uio *uio, 95 struct ucred *cred, int flags, struct thread *td)); 96 static int badfo_ioctl __P((struct file *fp, u_long com, caddr_t data, 97 struct thread *td)); 98 static int badfo_poll __P((struct file *fp, int events, 99 struct ucred *cred, struct thread *td)); 100 static int badfo_kqfilter __P((struct file *fp, struct knote *kn)); 101 static int badfo_stat __P((struct file *fp, struct stat *sb, struct thread *td)); 102 static int badfo_close __P((struct file *fp, struct thread *td)); 103 104 /* 105 * Descriptor management. 106 */ 107 struct filelist filehead; /* head of list of open files */ 108 int nfiles; /* actual number of open files */ 109 extern int cmask; 110 111 /* 112 * System calls on descriptors. 113 */ 114 #ifndef _SYS_SYSPROTO_H_ 115 struct getdtablesize_args { 116 int dummy; 117 }; 118 #endif 119 /* 120 * MPSAFE 121 */ 122 /* ARGSUSED */ 123 int 124 getdtablesize(td, uap) 125 struct thread *td; 126 struct getdtablesize_args *uap; 127 { 128 struct proc *p = td->td_proc; 129 130 mtx_lock(&Giant); 131 td->td_retval[0] = 132 min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc); 133 mtx_unlock(&Giant); 134 return (0); 135 } 136 137 /* 138 * Duplicate a file descriptor to a particular value. 139 * 140 * note: keep in mind that a potential race condition exists when closing 141 * descriptors from a shared descriptor table (via rfork). 142 */ 143 #ifndef _SYS_SYSPROTO_H_ 144 struct dup2_args { 145 u_int from; 146 u_int to; 147 }; 148 #endif 149 /* 150 * MPSAFE 151 */ 152 /* ARGSUSED */ 153 int 154 dup2(td, uap) 155 struct thread *td; 156 struct dup2_args *uap; 157 { 158 struct proc *p = td->td_proc; 159 register struct filedesc *fdp = td->td_proc->p_fd; 160 register u_int old = uap->from, new = uap->to; 161 int i, error; 162 163 mtx_lock(&Giant); 164 retry: 165 if (old >= fdp->fd_nfiles || 166 fdp->fd_ofiles[old] == NULL || 167 new >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur || 168 new >= maxfilesperproc) { 169 error = EBADF; 170 goto done2; 171 } 172 if (old == new) { 173 td->td_retval[0] = new; 174 error = 0; 175 goto done2; 176 } 177 if (new >= fdp->fd_nfiles) { 178 if ((error = fdalloc(td, new, &i))) 179 goto done2; 180 if (new != i) 181 panic("dup2: fdalloc"); 182 /* 183 * fdalloc() may block, retest everything. 184 */ 185 goto retry; 186 } 187 error = do_dup(fdp, (int)old, (int)new, td->td_retval, td); 188 done2: 189 mtx_unlock(&Giant); 190 return(error); 191 } 192 193 /* 194 * Duplicate a file descriptor. 195 */ 196 #ifndef _SYS_SYSPROTO_H_ 197 struct dup_args { 198 u_int fd; 199 }; 200 #endif 201 /* 202 * MPSAFE 203 */ 204 /* ARGSUSED */ 205 int 206 dup(td, uap) 207 struct thread *td; 208 struct dup_args *uap; 209 { 210 register struct filedesc *fdp; 211 u_int old; 212 int new, error; 213 214 mtx_lock(&Giant); 215 old = uap->fd; 216 fdp = td->td_proc->p_fd; 217 if (old >= fdp->fd_nfiles || fdp->fd_ofiles[old] == NULL) { 218 error = EBADF; 219 goto done2; 220 } 221 if ((error = fdalloc(td, 0, &new))) 222 goto done2; 223 error = do_dup(fdp, (int)old, new, td->td_retval, td); 224 done2: 225 mtx_unlock(&Giant); 226 return (error); 227 } 228 229 /* 230 * The file control system call. 231 */ 232 #ifndef _SYS_SYSPROTO_H_ 233 struct fcntl_args { 234 int fd; 235 int cmd; 236 long arg; 237 }; 238 #endif 239 /* 240 * MPSAFE 241 */ 242 /* ARGSUSED */ 243 int 244 fcntl(td, uap) 245 struct thread *td; 246 register struct fcntl_args *uap; 247 { 248 register struct proc *p = td->td_proc; 249 register struct filedesc *fdp; 250 register struct file *fp; 251 register char *pop; 252 struct vnode *vp; 253 int i, tmp, error = 0, flg = F_POSIX; 254 struct flock fl; 255 u_int newmin; 256 257 mtx_lock(&Giant); 258 259 fdp = p->p_fd; 260 if ((unsigned)uap->fd >= fdp->fd_nfiles || 261 (fp = fdp->fd_ofiles[uap->fd]) == NULL) { 262 error = EBADF; 263 goto done2; 264 } 265 pop = &fdp->fd_ofileflags[uap->fd]; 266 267 switch (uap->cmd) { 268 case F_DUPFD: 269 newmin = uap->arg; 270 if (newmin >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur || 271 newmin >= maxfilesperproc) { 272 error = EINVAL; 273 break; 274 } 275 if ((error = fdalloc(td, newmin, &i))) 276 break; 277 error = do_dup(fdp, uap->fd, i, td->td_retval, td); 278 break; 279 280 case F_GETFD: 281 td->td_retval[0] = *pop & 1; 282 break; 283 284 case F_SETFD: 285 *pop = (*pop &~ 1) | (uap->arg & 1); 286 break; 287 288 case F_GETFL: 289 td->td_retval[0] = OFLAGS(fp->f_flag); 290 break; 291 292 case F_SETFL: 293 fhold(fp); 294 fp->f_flag &= ~FCNTLFLAGS; 295 fp->f_flag |= FFLAGS(uap->arg & ~O_ACCMODE) & FCNTLFLAGS; 296 tmp = fp->f_flag & FNONBLOCK; 297 error = fo_ioctl(fp, FIONBIO, (caddr_t)&tmp, td); 298 if (error) { 299 fdrop(fp, td); 300 break; 301 } 302 tmp = fp->f_flag & FASYNC; 303 error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp, td); 304 if (!error) { 305 fdrop(fp, td); 306 break; 307 } 308 fp->f_flag &= ~FNONBLOCK; 309 tmp = 0; 310 (void)fo_ioctl(fp, FIONBIO, (caddr_t)&tmp, td); 311 fdrop(fp, td); 312 break; 313 314 case F_GETOWN: 315 fhold(fp); 316 error = fo_ioctl(fp, FIOGETOWN, (caddr_t)td->td_retval, td); 317 fdrop(fp, td); 318 break; 319 320 case F_SETOWN: 321 fhold(fp); 322 error = fo_ioctl(fp, FIOSETOWN, (caddr_t)&uap->arg, td); 323 fdrop(fp, td); 324 break; 325 326 case F_SETLKW: 327 flg |= F_WAIT; 328 /* Fall into F_SETLK */ 329 330 case F_SETLK: 331 if (fp->f_type != DTYPE_VNODE) { 332 error = EBADF; 333 break; 334 } 335 vp = (struct vnode *)fp->f_data; 336 337 /* 338 * copyin/lockop may block 339 */ 340 fhold(fp); 341 /* Copy in the lock structure */ 342 error = copyin((caddr_t)(intptr_t)uap->arg, (caddr_t)&fl, 343 sizeof(fl)); 344 if (error) { 345 fdrop(fp, td); 346 break; 347 } 348 if (fl.l_whence == SEEK_CUR) { 349 if (fp->f_offset < 0 || 350 (fl.l_start > 0 && 351 fp->f_offset > OFF_MAX - fl.l_start)) { 352 fdrop(fp, td); 353 error = EOVERFLOW; 354 break; 355 } 356 fl.l_start += fp->f_offset; 357 } 358 359 switch (fl.l_type) { 360 case F_RDLCK: 361 if ((fp->f_flag & FREAD) == 0) { 362 error = EBADF; 363 break; 364 } 365 p->p_flag |= P_ADVLOCK; 366 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 367 &fl, flg); 368 break; 369 case F_WRLCK: 370 if ((fp->f_flag & FWRITE) == 0) { 371 error = EBADF; 372 break; 373 } 374 p->p_flag |= P_ADVLOCK; 375 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 376 &fl, flg); 377 break; 378 case F_UNLCK: 379 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 380 &fl, F_POSIX); 381 break; 382 default: 383 error = EINVAL; 384 break; 385 } 386 fdrop(fp, td); 387 break; 388 389 case F_GETLK: 390 if (fp->f_type != DTYPE_VNODE) { 391 error = EBADF; 392 break; 393 } 394 vp = (struct vnode *)fp->f_data; 395 /* 396 * copyin/lockop may block 397 */ 398 fhold(fp); 399 /* Copy in the lock structure */ 400 error = copyin((caddr_t)(intptr_t)uap->arg, (caddr_t)&fl, 401 sizeof(fl)); 402 if (error) { 403 fdrop(fp, td); 404 break; 405 } 406 if (fl.l_type != F_RDLCK && fl.l_type != F_WRLCK && 407 fl.l_type != F_UNLCK) { 408 fdrop(fp, td); 409 error = EINVAL; 410 break; 411 } 412 if (fl.l_whence == SEEK_CUR) { 413 if ((fl.l_start > 0 && 414 fp->f_offset > OFF_MAX - fl.l_start) || 415 (fl.l_start < 0 && 416 fp->f_offset < OFF_MIN - fl.l_start)) { 417 fdrop(fp, td); 418 error = EOVERFLOW; 419 break; 420 } 421 fl.l_start += fp->f_offset; 422 } 423 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, 424 &fl, F_POSIX); 425 fdrop(fp, td); 426 if (error == 0) { 427 error = copyout((caddr_t)&fl, 428 (caddr_t)(intptr_t)uap->arg, sizeof(fl)); 429 } 430 break; 431 default: 432 error = EINVAL; 433 break; 434 } 435 done2: 436 mtx_unlock(&Giant); 437 return (error); 438 } 439 440 /* 441 * Common code for dup, dup2, and fcntl(F_DUPFD). 442 */ 443 static int 444 do_dup(fdp, old, new, retval, td) 445 register struct filedesc *fdp; 446 register int old, new; 447 register_t *retval; 448 struct thread *td; 449 { 450 struct file *fp; 451 struct file *delfp; 452 453 /* 454 * Save info on the descriptor being overwritten. We have 455 * to do the unmap now, but we cannot close it without 456 * introducing an ownership race for the slot. 457 */ 458 delfp = fdp->fd_ofiles[new]; 459 #if 0 460 if (delfp && (fdp->fd_ofileflags[new] & UF_MAPPED)) 461 (void) munmapfd(td, new); 462 #endif 463 464 /* 465 * Duplicate the source descriptor, update lastfile 466 */ 467 fp = fdp->fd_ofiles[old]; 468 fdp->fd_ofiles[new] = fp; 469 fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] &~ UF_EXCLOSE; 470 fhold(fp); 471 if (new > fdp->fd_lastfile) 472 fdp->fd_lastfile = new; 473 *retval = new; 474 475 /* 476 * If we dup'd over a valid file, we now own the reference to it 477 * and must dispose of it using closef() semantics (as if a 478 * close() were performed on it). 479 */ 480 if (delfp) 481 (void) closef(delfp, td); 482 return (0); 483 } 484 485 /* 486 * If sigio is on the list associated with a process or process group, 487 * disable signalling from the device, remove sigio from the list and 488 * free sigio. 489 */ 490 void 491 funsetown(sigio) 492 struct sigio *sigio; 493 { 494 int s; 495 496 if (sigio == NULL) 497 return; 498 s = splhigh(); 499 *(sigio->sio_myref) = NULL; 500 splx(s); 501 if (sigio->sio_pgid < 0) { 502 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 503 sigio, sio_pgsigio); 504 } else /* if ((*sigiop)->sio_pgid > 0) */ { 505 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 506 sigio, sio_pgsigio); 507 } 508 crfree(sigio->sio_ucred); 509 FREE(sigio, M_SIGIO); 510 } 511 512 /* Free a list of sigio structures. */ 513 void 514 funsetownlst(sigiolst) 515 struct sigiolst *sigiolst; 516 { 517 struct sigio *sigio; 518 519 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) 520 funsetown(sigio); 521 } 522 523 /* 524 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 525 * 526 * After permission checking, add a sigio structure to the sigio list for 527 * the process or process group. 528 */ 529 int 530 fsetown(pgid, sigiop) 531 pid_t pgid; 532 struct sigio **sigiop; 533 { 534 struct proc *proc; 535 struct pgrp *pgrp; 536 struct sigio *sigio; 537 int s; 538 539 if (pgid == 0) { 540 funsetown(*sigiop); 541 return (0); 542 } 543 if (pgid > 0) { 544 proc = pfind(pgid); 545 if (proc == NULL) 546 return (ESRCH); 547 548 /* 549 * Policy - Don't allow a process to FSETOWN a process 550 * in another session. 551 * 552 * Remove this test to allow maximum flexibility or 553 * restrict FSETOWN to the current process or process 554 * group for maximum safety. 555 */ 556 if (proc->p_session != curthread->td_proc->p_session) { 557 PROC_UNLOCK(proc); 558 return (EPERM); 559 } 560 PROC_UNLOCK(proc); 561 562 pgrp = NULL; 563 } else /* if (pgid < 0) */ { 564 pgrp = pgfind(-pgid); 565 if (pgrp == NULL) 566 return (ESRCH); 567 568 /* 569 * Policy - Don't allow a process to FSETOWN a process 570 * in another session. 571 * 572 * Remove this test to allow maximum flexibility or 573 * restrict FSETOWN to the current process or process 574 * group for maximum safety. 575 */ 576 if (pgrp->pg_session != curthread->td_proc->p_session) 577 return (EPERM); 578 579 proc = NULL; 580 } 581 funsetown(*sigiop); 582 MALLOC(sigio, struct sigio *, sizeof(struct sigio), M_SIGIO, M_WAITOK); 583 if (pgid > 0) { 584 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 585 sigio->sio_proc = proc; 586 } else { 587 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 588 sigio->sio_pgrp = pgrp; 589 } 590 sigio->sio_pgid = pgid; 591 sigio->sio_ucred = crhold(curthread->td_proc->p_ucred); 592 sigio->sio_myref = sigiop; 593 s = splhigh(); 594 *sigiop = sigio; 595 splx(s); 596 return (0); 597 } 598 599 /* 600 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 601 */ 602 pid_t 603 fgetown(sigio) 604 struct sigio *sigio; 605 { 606 return (sigio != NULL ? sigio->sio_pgid : 0); 607 } 608 609 /* 610 * Close a file descriptor. 611 */ 612 #ifndef _SYS_SYSPROTO_H_ 613 struct close_args { 614 int fd; 615 }; 616 #endif 617 /* 618 * MPSAFE 619 */ 620 /* ARGSUSED */ 621 int 622 close(td, uap) 623 struct thread *td; 624 struct close_args *uap; 625 { 626 register struct filedesc *fdp; 627 register struct file *fp; 628 register int fd = uap->fd; 629 int error = 0; 630 631 mtx_lock(&Giant); 632 fdp = td->td_proc->p_fd; 633 if ((unsigned)fd >= fdp->fd_nfiles || 634 (fp = fdp->fd_ofiles[fd]) == NULL) { 635 error = EBADF; 636 goto done2; 637 } 638 #if 0 639 if (fdp->fd_ofileflags[fd] & UF_MAPPED) 640 (void) munmapfd(td, fd); 641 #endif 642 fdp->fd_ofiles[fd] = NULL; 643 fdp->fd_ofileflags[fd] = 0; 644 645 /* 646 * we now hold the fp reference that used to be owned by the descriptor 647 * array. 648 */ 649 while (fdp->fd_lastfile > 0 && fdp->fd_ofiles[fdp->fd_lastfile] == NULL) 650 fdp->fd_lastfile--; 651 if (fd < fdp->fd_freefile) 652 fdp->fd_freefile = fd; 653 if (fd < fdp->fd_knlistsize) 654 knote_fdclose(td, fd); 655 error = closef(fp, td); 656 done2: 657 mtx_unlock(&Giant); 658 return(error); 659 } 660 661 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 662 /* 663 * Return status information about a file descriptor. 664 */ 665 #ifndef _SYS_SYSPROTO_H_ 666 struct ofstat_args { 667 int fd; 668 struct ostat *sb; 669 }; 670 #endif 671 /* 672 * MPSAFE 673 */ 674 /* ARGSUSED */ 675 int 676 ofstat(td, uap) 677 struct thread *td; 678 register struct ofstat_args *uap; 679 { 680 register struct filedesc *fdp = td->td_proc->p_fd; 681 register struct file *fp; 682 struct stat ub; 683 struct ostat oub; 684 int error; 685 686 mtx_lock(&Giant); 687 688 if ((unsigned)uap->fd >= fdp->fd_nfiles || 689 (fp = fdp->fd_ofiles[uap->fd]) == NULL) { 690 error = EBADF; 691 goto done2; 692 } 693 fhold(fp); 694 error = fo_stat(fp, &ub, td); 695 if (error == 0) { 696 cvtstat(&ub, &oub); 697 error = copyout((caddr_t)&oub, (caddr_t)uap->sb, sizeof (oub)); 698 } 699 fdrop(fp, td); 700 done2: 701 mtx_unlock(&Giant); 702 return (error); 703 } 704 #endif /* COMPAT_43 || COMPAT_SUNOS */ 705 706 /* 707 * Return status information about a file descriptor. 708 */ 709 #ifndef _SYS_SYSPROTO_H_ 710 struct fstat_args { 711 int fd; 712 struct stat *sb; 713 }; 714 #endif 715 /* 716 * MPSAFE 717 */ 718 /* ARGSUSED */ 719 int 720 fstat(td, uap) 721 struct thread *td; 722 register struct fstat_args *uap; 723 { 724 register struct filedesc *fdp; 725 register struct file *fp; 726 struct stat ub; 727 int error; 728 729 mtx_lock(&Giant); 730 fdp = td->td_proc->p_fd; 731 732 if ((unsigned)uap->fd >= fdp->fd_nfiles || 733 (fp = fdp->fd_ofiles[uap->fd]) == NULL) { 734 error = EBADF; 735 goto done2; 736 } 737 fhold(fp); 738 error = fo_stat(fp, &ub, td); 739 if (error == 0) 740 error = copyout((caddr_t)&ub, (caddr_t)uap->sb, sizeof (ub)); 741 fdrop(fp, td); 742 done2: 743 mtx_unlock(&Giant); 744 return (error); 745 } 746 747 /* 748 * Return status information about a file descriptor. 749 */ 750 #ifndef _SYS_SYSPROTO_H_ 751 struct nfstat_args { 752 int fd; 753 struct nstat *sb; 754 }; 755 #endif 756 /* 757 * MPSAFE 758 */ 759 /* ARGSUSED */ 760 int 761 nfstat(td, uap) 762 struct thread *td; 763 register struct nfstat_args *uap; 764 { 765 register struct filedesc *fdp; 766 register struct file *fp; 767 struct stat ub; 768 struct nstat nub; 769 int error; 770 771 mtx_lock(&Giant); 772 773 fdp = td->td_proc->p_fd; 774 if ((unsigned)uap->fd >= fdp->fd_nfiles || 775 (fp = fdp->fd_ofiles[uap->fd]) == NULL) { 776 error = EBADF; 777 goto done2; 778 } 779 fhold(fp); 780 error = fo_stat(fp, &ub, td); 781 if (error == 0) { 782 cvtnstat(&ub, &nub); 783 error = copyout((caddr_t)&nub, (caddr_t)uap->sb, sizeof (nub)); 784 } 785 fdrop(fp, td); 786 done2: 787 mtx_unlock(&Giant); 788 return (error); 789 } 790 791 /* 792 * Return pathconf information about a file descriptor. 793 */ 794 #ifndef _SYS_SYSPROTO_H_ 795 struct fpathconf_args { 796 int fd; 797 int name; 798 }; 799 #endif 800 /* 801 * MPSAFE 802 */ 803 /* ARGSUSED */ 804 int 805 fpathconf(td, uap) 806 struct thread *td; 807 register struct fpathconf_args *uap; 808 { 809 struct filedesc *fdp; 810 struct file *fp; 811 struct vnode *vp; 812 int error = 0; 813 814 mtx_lock(&Giant); 815 fdp = td->td_proc->p_fd; 816 817 if ((unsigned)uap->fd >= fdp->fd_nfiles || 818 (fp = fdp->fd_ofiles[uap->fd]) == NULL) { 819 error = EBADF; 820 goto done2; 821 } 822 823 fhold(fp); 824 825 switch (fp->f_type) { 826 case DTYPE_PIPE: 827 case DTYPE_SOCKET: 828 if (uap->name != _PC_PIPE_BUF) { 829 error = EINVAL; 830 goto done2; 831 } 832 td->td_retval[0] = PIPE_BUF; 833 error = 0; 834 break; 835 case DTYPE_FIFO: 836 case DTYPE_VNODE: 837 vp = (struct vnode *)fp->f_data; 838 error = VOP_PATHCONF(vp, uap->name, td->td_retval); 839 break; 840 default: 841 error = EOPNOTSUPP; 842 break; 843 } 844 fdrop(fp, td); 845 done2: 846 mtx_unlock(&Giant); 847 return(error); 848 } 849 850 /* 851 * Allocate a file descriptor for the process. 852 */ 853 static int fdexpand; 854 SYSCTL_INT(_debug, OID_AUTO, fdexpand, CTLFLAG_RD, &fdexpand, 0, ""); 855 856 int 857 fdalloc(td, want, result) 858 struct thread *td; 859 int want; 860 int *result; 861 { 862 struct proc *p = td->td_proc; 863 register struct filedesc *fdp = td->td_proc->p_fd; 864 register int i; 865 int lim, last, nfiles; 866 struct file **newofile; 867 char *newofileflags; 868 869 /* 870 * Search for a free descriptor starting at the higher 871 * of want or fd_freefile. If that fails, consider 872 * expanding the ofile array. 873 */ 874 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc); 875 for (;;) { 876 last = min(fdp->fd_nfiles, lim); 877 if ((i = want) < fdp->fd_freefile) 878 i = fdp->fd_freefile; 879 for (; i < last; i++) { 880 if (fdp->fd_ofiles[i] == NULL) { 881 fdp->fd_ofileflags[i] = 0; 882 if (i > fdp->fd_lastfile) 883 fdp->fd_lastfile = i; 884 if (want <= fdp->fd_freefile) 885 fdp->fd_freefile = i; 886 *result = i; 887 return (0); 888 } 889 } 890 891 /* 892 * No space in current array. Expand? 893 */ 894 if (fdp->fd_nfiles >= lim) 895 return (EMFILE); 896 if (fdp->fd_nfiles < NDEXTENT) 897 nfiles = NDEXTENT; 898 else 899 nfiles = 2 * fdp->fd_nfiles; 900 MALLOC(newofile, struct file **, nfiles * OFILESIZE, 901 M_FILEDESC, M_WAITOK); 902 903 /* 904 * deal with file-table extend race that might have occured 905 * when malloc was blocked. 906 */ 907 if (fdp->fd_nfiles >= nfiles) { 908 FREE(newofile, M_FILEDESC); 909 continue; 910 } 911 newofileflags = (char *) &newofile[nfiles]; 912 /* 913 * Copy the existing ofile and ofileflags arrays 914 * and zero the new portion of each array. 915 */ 916 bcopy(fdp->fd_ofiles, newofile, 917 (i = sizeof(struct file *) * fdp->fd_nfiles)); 918 bzero((char *)newofile + i, nfiles * sizeof(struct file *) - i); 919 bcopy(fdp->fd_ofileflags, newofileflags, 920 (i = sizeof(char) * fdp->fd_nfiles)); 921 bzero(newofileflags + i, nfiles * sizeof(char) - i); 922 if (fdp->fd_nfiles > NDFILE) 923 FREE(fdp->fd_ofiles, M_FILEDESC); 924 fdp->fd_ofiles = newofile; 925 fdp->fd_ofileflags = newofileflags; 926 fdp->fd_nfiles = nfiles; 927 fdexpand++; 928 } 929 return (0); 930 } 931 932 /* 933 * Check to see whether n user file descriptors 934 * are available to the process p. 935 */ 936 int 937 fdavail(td, n) 938 struct thread *td; 939 register int n; 940 { 941 struct proc *p = td->td_proc; 942 register struct filedesc *fdp = td->td_proc->p_fd; 943 register struct file **fpp; 944 register int i, lim, last; 945 946 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc); 947 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) 948 return (1); 949 950 last = min(fdp->fd_nfiles, lim); 951 fpp = &fdp->fd_ofiles[fdp->fd_freefile]; 952 for (i = last - fdp->fd_freefile; --i >= 0; fpp++) { 953 if (*fpp == NULL && --n <= 0) 954 return (1); 955 } 956 return (0); 957 } 958 959 /* 960 * Create a new open file structure and allocate 961 * a file decriptor for the process that refers to it. 962 */ 963 int 964 falloc(td, resultfp, resultfd) 965 register struct thread *td; 966 struct file **resultfp; 967 int *resultfd; 968 { 969 struct proc *p = td->td_proc; 970 register struct file *fp, *fq; 971 int error, i; 972 973 if (nfiles >= maxfiles) { 974 tablefull("file"); 975 return (ENFILE); 976 } 977 /* 978 * Allocate a new file descriptor. 979 * If the process has file descriptor zero open, add to the list 980 * of open files at that point, otherwise put it at the front of 981 * the list of open files. 982 */ 983 nfiles++; 984 MALLOC(fp, struct file *, sizeof(struct file), M_FILE, M_WAITOK | M_ZERO); 985 986 /* 987 * wait until after malloc (which may have blocked) returns before 988 * allocating the slot, else a race might have shrunk it if we had 989 * allocated it before the malloc. 990 */ 991 if ((error = fdalloc(td, 0, &i))) { 992 nfiles--; 993 FREE(fp, M_FILE); 994 return (error); 995 } 996 fp->f_count = 1; 997 fp->f_cred = crhold(p->p_ucred); 998 fp->f_ops = &badfileops; 999 fp->f_seqcount = 1; 1000 if ((fq = p->p_fd->fd_ofiles[0])) { 1001 LIST_INSERT_AFTER(fq, fp, f_list); 1002 } else { 1003 LIST_INSERT_HEAD(&filehead, fp, f_list); 1004 } 1005 p->p_fd->fd_ofiles[i] = fp; 1006 if (resultfp) 1007 *resultfp = fp; 1008 if (resultfd) 1009 *resultfd = i; 1010 return (0); 1011 } 1012 1013 /* 1014 * Free a file descriptor. 1015 */ 1016 void 1017 ffree(fp) 1018 register struct file *fp; 1019 { 1020 KASSERT((fp->f_count == 0), ("ffree: fp_fcount not 0!")); 1021 LIST_REMOVE(fp, f_list); 1022 crfree(fp->f_cred); 1023 nfiles--; 1024 FREE(fp, M_FILE); 1025 } 1026 1027 /* 1028 * Build a new filedesc structure. 1029 */ 1030 struct filedesc * 1031 fdinit(td) 1032 struct thread *td; 1033 { 1034 register struct filedesc0 *newfdp; 1035 register struct filedesc *fdp = td->td_proc->p_fd; 1036 1037 MALLOC(newfdp, struct filedesc0 *, sizeof(struct filedesc0), 1038 M_FILEDESC, M_WAITOK | M_ZERO); 1039 newfdp->fd_fd.fd_cdir = fdp->fd_cdir; 1040 if (newfdp->fd_fd.fd_cdir) 1041 VREF(newfdp->fd_fd.fd_cdir); 1042 newfdp->fd_fd.fd_rdir = fdp->fd_rdir; 1043 if (newfdp->fd_fd.fd_rdir) 1044 VREF(newfdp->fd_fd.fd_rdir); 1045 newfdp->fd_fd.fd_jdir = fdp->fd_jdir; 1046 if (newfdp->fd_fd.fd_jdir) 1047 VREF(newfdp->fd_fd.fd_jdir); 1048 1049 /* Create the file descriptor table. */ 1050 newfdp->fd_fd.fd_refcnt = 1; 1051 newfdp->fd_fd.fd_cmask = cmask; 1052 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles; 1053 newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags; 1054 newfdp->fd_fd.fd_nfiles = NDFILE; 1055 newfdp->fd_fd.fd_knlistsize = -1; 1056 1057 return (&newfdp->fd_fd); 1058 } 1059 1060 /* 1061 * Share a filedesc structure. 1062 */ 1063 struct filedesc * 1064 fdshare(p) 1065 struct proc *p; 1066 { 1067 p->p_fd->fd_refcnt++; 1068 return (p->p_fd); 1069 } 1070 1071 /* 1072 * Copy a filedesc structure. 1073 */ 1074 struct filedesc * 1075 fdcopy(td) 1076 struct thread *td; 1077 { 1078 register struct filedesc *newfdp, *fdp = td->td_proc->p_fd; 1079 register struct file **fpp; 1080 register int i; 1081 1082 /* Certain daemons might not have file descriptors. */ 1083 if (fdp == NULL) 1084 return (NULL); 1085 1086 MALLOC(newfdp, struct filedesc *, sizeof(struct filedesc0), 1087 M_FILEDESC, M_WAITOK); 1088 bcopy(fdp, newfdp, sizeof(struct filedesc)); 1089 if (newfdp->fd_cdir) 1090 VREF(newfdp->fd_cdir); 1091 if (newfdp->fd_rdir) 1092 VREF(newfdp->fd_rdir); 1093 if (newfdp->fd_jdir) 1094 VREF(newfdp->fd_jdir); 1095 newfdp->fd_refcnt = 1; 1096 1097 /* 1098 * If the number of open files fits in the internal arrays 1099 * of the open file structure, use them, otherwise allocate 1100 * additional memory for the number of descriptors currently 1101 * in use. 1102 */ 1103 if (newfdp->fd_lastfile < NDFILE) { 1104 newfdp->fd_ofiles = ((struct filedesc0 *) newfdp)->fd_dfiles; 1105 newfdp->fd_ofileflags = 1106 ((struct filedesc0 *) newfdp)->fd_dfileflags; 1107 i = NDFILE; 1108 } else { 1109 /* 1110 * Compute the smallest multiple of NDEXTENT needed 1111 * for the file descriptors currently in use, 1112 * allowing the table to shrink. 1113 */ 1114 i = newfdp->fd_nfiles; 1115 while (i > 2 * NDEXTENT && i > newfdp->fd_lastfile * 2) 1116 i /= 2; 1117 MALLOC(newfdp->fd_ofiles, struct file **, i * OFILESIZE, 1118 M_FILEDESC, M_WAITOK); 1119 newfdp->fd_ofileflags = (char *) &newfdp->fd_ofiles[i]; 1120 } 1121 newfdp->fd_nfiles = i; 1122 bcopy(fdp->fd_ofiles, newfdp->fd_ofiles, i * sizeof(struct file **)); 1123 bcopy(fdp->fd_ofileflags, newfdp->fd_ofileflags, i * sizeof(char)); 1124 1125 /* 1126 * kq descriptors cannot be copied. 1127 */ 1128 if (newfdp->fd_knlistsize != -1) { 1129 fpp = newfdp->fd_ofiles; 1130 for (i = newfdp->fd_lastfile; i-- >= 0; fpp++) { 1131 if (*fpp != NULL && (*fpp)->f_type == DTYPE_KQUEUE) 1132 *fpp = NULL; 1133 } 1134 newfdp->fd_knlist = NULL; 1135 newfdp->fd_knlistsize = -1; 1136 newfdp->fd_knhash = NULL; 1137 newfdp->fd_knhashmask = 0; 1138 } 1139 1140 fpp = newfdp->fd_ofiles; 1141 for (i = newfdp->fd_lastfile; i-- >= 0; fpp++) { 1142 if (*fpp != NULL) 1143 fhold(*fpp); 1144 } 1145 return (newfdp); 1146 } 1147 1148 /* 1149 * Release a filedesc structure. 1150 */ 1151 void 1152 fdfree(td) 1153 struct thread *td; 1154 { 1155 register struct filedesc *fdp = td->td_proc->p_fd; 1156 struct file **fpp; 1157 register int i; 1158 1159 /* Certain daemons might not have file descriptors. */ 1160 if (fdp == NULL) 1161 return; 1162 1163 if (--fdp->fd_refcnt > 0) 1164 return; 1165 /* 1166 * we are the last reference to the structure, we can 1167 * safely assume it will not change out from under us. 1168 */ 1169 fpp = fdp->fd_ofiles; 1170 for (i = fdp->fd_lastfile; i-- >= 0; fpp++) { 1171 if (*fpp) 1172 (void) closef(*fpp, td); 1173 } 1174 if (fdp->fd_nfiles > NDFILE) 1175 FREE(fdp->fd_ofiles, M_FILEDESC); 1176 if (fdp->fd_cdir) 1177 vrele(fdp->fd_cdir); 1178 if (fdp->fd_rdir) 1179 vrele(fdp->fd_rdir); 1180 if (fdp->fd_jdir) 1181 vrele(fdp->fd_jdir); 1182 if (fdp->fd_knlist) 1183 FREE(fdp->fd_knlist, M_KQUEUE); 1184 if (fdp->fd_knhash) 1185 FREE(fdp->fd_knhash, M_KQUEUE); 1186 FREE(fdp, M_FILEDESC); 1187 } 1188 1189 /* 1190 * For setugid programs, we don't want to people to use that setugidness 1191 * to generate error messages which write to a file which otherwise would 1192 * otherwise be off-limits to the process. 1193 * 1194 * This is a gross hack to plug the hole. A better solution would involve 1195 * a special vop or other form of generalized access control mechanism. We 1196 * go ahead and just reject all procfs file systems accesses as dangerous. 1197 * 1198 * Since setugidsafety calls this only for fd 0, 1 and 2, this check is 1199 * sufficient. We also don't for check setugidness since we know we are. 1200 */ 1201 static int 1202 is_unsafe(struct file *fp) 1203 { 1204 if (fp->f_type == DTYPE_VNODE && 1205 ((struct vnode *)(fp->f_data))->v_tag == VT_PROCFS) 1206 return (1); 1207 return (0); 1208 } 1209 1210 /* 1211 * Make this setguid thing safe, if at all possible. 1212 */ 1213 void 1214 setugidsafety(td) 1215 struct thread *td; 1216 { 1217 struct filedesc *fdp = td->td_proc->p_fd; 1218 register int i; 1219 1220 /* Certain daemons might not have file descriptors. */ 1221 if (fdp == NULL) 1222 return; 1223 1224 /* 1225 * note: fdp->fd_ofiles may be reallocated out from under us while 1226 * we are blocked in a close. Be careful! 1227 */ 1228 for (i = 0; i <= fdp->fd_lastfile; i++) { 1229 if (i > 2) 1230 break; 1231 if (fdp->fd_ofiles[i] && is_unsafe(fdp->fd_ofiles[i])) { 1232 struct file *fp; 1233 1234 #if 0 1235 if ((fdp->fd_ofileflags[i] & UF_MAPPED) != 0) 1236 (void) munmapfd(td, i); 1237 #endif 1238 if (i < fdp->fd_knlistsize) 1239 knote_fdclose(td, i); 1240 /* 1241 * NULL-out descriptor prior to close to avoid 1242 * a race while close blocks. 1243 */ 1244 fp = fdp->fd_ofiles[i]; 1245 fdp->fd_ofiles[i] = NULL; 1246 fdp->fd_ofileflags[i] = 0; 1247 if (i < fdp->fd_freefile) 1248 fdp->fd_freefile = i; 1249 (void) closef(fp, td); 1250 } 1251 } 1252 while (fdp->fd_lastfile > 0 && fdp->fd_ofiles[fdp->fd_lastfile] == NULL) 1253 fdp->fd_lastfile--; 1254 } 1255 1256 /* 1257 * Close any files on exec? 1258 */ 1259 void 1260 fdcloseexec(td) 1261 struct thread *td; 1262 { 1263 struct filedesc *fdp = td->td_proc->p_fd; 1264 register int i; 1265 1266 /* Certain daemons might not have file descriptors. */ 1267 if (fdp == NULL) 1268 return; 1269 1270 /* 1271 * We cannot cache fd_ofiles or fd_ofileflags since operations 1272 * may block and rip them out from under us. 1273 */ 1274 for (i = 0; i <= fdp->fd_lastfile; i++) { 1275 if (fdp->fd_ofiles[i] != NULL && 1276 (fdp->fd_ofileflags[i] & UF_EXCLOSE)) { 1277 struct file *fp; 1278 1279 #if 0 1280 if (fdp->fd_ofileflags[i] & UF_MAPPED) 1281 (void) munmapfd(td, i); 1282 #endif 1283 if (i < fdp->fd_knlistsize) 1284 knote_fdclose(td, i); 1285 /* 1286 * NULL-out descriptor prior to close to avoid 1287 * a race while close blocks. 1288 */ 1289 fp = fdp->fd_ofiles[i]; 1290 fdp->fd_ofiles[i] = NULL; 1291 fdp->fd_ofileflags[i] = 0; 1292 if (i < fdp->fd_freefile) 1293 fdp->fd_freefile = i; 1294 (void) closef(fp, td); 1295 } 1296 } 1297 while (fdp->fd_lastfile > 0 && fdp->fd_ofiles[fdp->fd_lastfile] == NULL) 1298 fdp->fd_lastfile--; 1299 } 1300 1301 /* 1302 * Internal form of close. 1303 * Decrement reference count on file structure. 1304 * Note: td may be NULL when closing a file 1305 * that was being passed in a message. 1306 */ 1307 int 1308 closef(fp, td) 1309 register struct file *fp; 1310 register struct thread *td; 1311 { 1312 struct vnode *vp; 1313 struct flock lf; 1314 1315 if (fp == NULL) 1316 return (0); 1317 /* 1318 * POSIX record locking dictates that any close releases ALL 1319 * locks owned by this process. This is handled by setting 1320 * a flag in the unlock to free ONLY locks obeying POSIX 1321 * semantics, and not to free BSD-style file locks. 1322 * If the descriptor was in a message, POSIX-style locks 1323 * aren't passed with the descriptor. 1324 */ 1325 if (td && (td->td_proc->p_flag & P_ADVLOCK) && 1326 fp->f_type == DTYPE_VNODE) { 1327 lf.l_whence = SEEK_SET; 1328 lf.l_start = 0; 1329 lf.l_len = 0; 1330 lf.l_type = F_UNLCK; 1331 vp = (struct vnode *)fp->f_data; 1332 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 1333 F_UNLCK, &lf, F_POSIX); 1334 } 1335 return (fdrop(fp, td)); 1336 } 1337 1338 int 1339 fdrop(fp, td) 1340 struct file *fp; 1341 struct thread *td; 1342 { 1343 struct flock lf; 1344 struct vnode *vp; 1345 int error; 1346 1347 if (--fp->f_count > 0) 1348 return (0); 1349 if (fp->f_count < 0) 1350 panic("fdrop: count < 0"); 1351 if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE) { 1352 lf.l_whence = SEEK_SET; 1353 lf.l_start = 0; 1354 lf.l_len = 0; 1355 lf.l_type = F_UNLCK; 1356 vp = (struct vnode *)fp->f_data; 1357 (void) VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 1358 } 1359 if (fp->f_ops != &badfileops) 1360 error = fo_close(fp, td); 1361 else 1362 error = 0; 1363 ffree(fp); 1364 return (error); 1365 } 1366 1367 /* 1368 * Apply an advisory lock on a file descriptor. 1369 * 1370 * Just attempt to get a record lock of the requested type on 1371 * the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0). 1372 */ 1373 #ifndef _SYS_SYSPROTO_H_ 1374 struct flock_args { 1375 int fd; 1376 int how; 1377 }; 1378 #endif 1379 /* 1380 * MPSAFE 1381 */ 1382 /* ARGSUSED */ 1383 int 1384 flock(td, uap) 1385 struct thread *td; 1386 register struct flock_args *uap; 1387 { 1388 register struct filedesc *fdp = td->td_proc->p_fd; 1389 register struct file *fp; 1390 struct vnode *vp; 1391 struct flock lf; 1392 int error; 1393 1394 mtx_lock(&Giant); 1395 1396 if ((unsigned)uap->fd >= fdp->fd_nfiles || 1397 (fp = fdp->fd_ofiles[uap->fd]) == NULL) { 1398 error = EBADF; 1399 goto done2; 1400 } 1401 if (fp->f_type != DTYPE_VNODE) { 1402 error = EOPNOTSUPP; 1403 goto done2; 1404 } 1405 vp = (struct vnode *)fp->f_data; 1406 lf.l_whence = SEEK_SET; 1407 lf.l_start = 0; 1408 lf.l_len = 0; 1409 if (uap->how & LOCK_UN) { 1410 lf.l_type = F_UNLCK; 1411 fp->f_flag &= ~FHASLOCK; 1412 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 1413 goto done2; 1414 } 1415 if (uap->how & LOCK_EX) 1416 lf.l_type = F_WRLCK; 1417 else if (uap->how & LOCK_SH) 1418 lf.l_type = F_RDLCK; 1419 else { 1420 error = EBADF; 1421 goto done2; 1422 } 1423 fp->f_flag |= FHASLOCK; 1424 if (uap->how & LOCK_NB) 1425 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK); 1426 else 1427 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK|F_WAIT); 1428 done2: 1429 mtx_unlock(&Giant); 1430 return (error); 1431 } 1432 1433 /* 1434 * File Descriptor pseudo-device driver (/dev/fd/). 1435 * 1436 * Opening minor device N dup()s the file (if any) connected to file 1437 * descriptor N belonging to the calling process. Note that this driver 1438 * consists of only the ``open()'' routine, because all subsequent 1439 * references to this file will be direct to the other driver. 1440 */ 1441 /* ARGSUSED */ 1442 static int 1443 fdopen(dev, mode, type, td) 1444 dev_t dev; 1445 int mode, type; 1446 struct thread *td; 1447 { 1448 1449 /* 1450 * XXX Kludge: set curthread->td_dupfd to contain the value of the 1451 * the file descriptor being sought for duplication. The error 1452 * return ensures that the vnode for this device will be released 1453 * by vn_open. Open will detect this special error and take the 1454 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 1455 * will simply report the error. 1456 */ 1457 td->td_dupfd = dev2unit(dev); 1458 return (ENODEV); 1459 } 1460 1461 /* 1462 * Duplicate the specified descriptor to a free descriptor. 1463 */ 1464 int 1465 dupfdopen(td, fdp, indx, dfd, mode, error) 1466 struct thread *td; 1467 struct filedesc *fdp; 1468 int indx, dfd; 1469 int mode; 1470 int error; 1471 { 1472 register struct file *wfp; 1473 struct file *fp; 1474 1475 /* 1476 * If the to-be-dup'd fd number is greater than the allowed number 1477 * of file descriptors, or the fd to be dup'd has already been 1478 * closed, then reject. 1479 */ 1480 if ((u_int)dfd >= fdp->fd_nfiles || 1481 (wfp = fdp->fd_ofiles[dfd]) == NULL) { 1482 return (EBADF); 1483 } 1484 1485 /* 1486 * There are two cases of interest here. 1487 * 1488 * For ENODEV simply dup (dfd) to file descriptor 1489 * (indx) and return. 1490 * 1491 * For ENXIO steal away the file structure from (dfd) and 1492 * store it in (indx). (dfd) is effectively closed by 1493 * this operation. 1494 * 1495 * Any other error code is just returned. 1496 */ 1497 switch (error) { 1498 case ENODEV: 1499 /* 1500 * Check that the mode the file is being opened for is a 1501 * subset of the mode of the existing descriptor. 1502 */ 1503 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) 1504 return (EACCES); 1505 fp = fdp->fd_ofiles[indx]; 1506 #if 0 1507 if (fp && fdp->fd_ofileflags[indx] & UF_MAPPED) 1508 (void) munmapfd(td, indx); 1509 #endif 1510 fdp->fd_ofiles[indx] = wfp; 1511 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 1512 fhold(wfp); 1513 if (indx > fdp->fd_lastfile) 1514 fdp->fd_lastfile = indx; 1515 /* 1516 * we now own the reference to fp that the ofiles[] array 1517 * used to own. Release it. 1518 */ 1519 if (fp) 1520 fdrop(fp, td); 1521 return (0); 1522 1523 case ENXIO: 1524 /* 1525 * Steal away the file pointer from dfd, and stuff it into indx. 1526 */ 1527 fp = fdp->fd_ofiles[indx]; 1528 #if 0 1529 if (fp && fdp->fd_ofileflags[indx] & UF_MAPPED) 1530 (void) munmapfd(td, indx); 1531 #endif 1532 fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd]; 1533 fdp->fd_ofiles[dfd] = NULL; 1534 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 1535 fdp->fd_ofileflags[dfd] = 0; 1536 1537 /* 1538 * we now own the reference to fp that the ofiles[] array 1539 * used to own. Release it. 1540 */ 1541 if (fp) 1542 fdrop(fp, td); 1543 /* 1544 * Complete the clean up of the filedesc structure by 1545 * recomputing the various hints. 1546 */ 1547 if (indx > fdp->fd_lastfile) { 1548 fdp->fd_lastfile = indx; 1549 } else { 1550 while (fdp->fd_lastfile > 0 && 1551 fdp->fd_ofiles[fdp->fd_lastfile] == NULL) { 1552 fdp->fd_lastfile--; 1553 } 1554 if (dfd < fdp->fd_freefile) 1555 fdp->fd_freefile = dfd; 1556 } 1557 return (0); 1558 1559 default: 1560 return (error); 1561 } 1562 /* NOTREACHED */ 1563 } 1564 1565 /* 1566 * Get file structures. 1567 */ 1568 static int 1569 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 1570 { 1571 int error; 1572 struct file *fp; 1573 1574 if (!req->oldptr) { 1575 /* 1576 * overestimate by 10 files 1577 */ 1578 return (SYSCTL_OUT(req, 0, sizeof(filehead) + 1579 (nfiles + 10) * sizeof(struct file))); 1580 } 1581 1582 error = SYSCTL_OUT(req, (caddr_t)&filehead, sizeof(filehead)); 1583 if (error) 1584 return (error); 1585 1586 /* 1587 * followed by an array of file structures 1588 */ 1589 LIST_FOREACH(fp, &filehead, f_list) { 1590 error = SYSCTL_OUT(req, (caddr_t)fp, sizeof (struct file)); 1591 if (error) 1592 return (error); 1593 } 1594 return (0); 1595 } 1596 1597 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD, 1598 0, 0, sysctl_kern_file, "S,file", "Entire file table"); 1599 1600 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 1601 &maxfilesperproc, 0, "Maximum files allowed open per process"); 1602 1603 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 1604 &maxfiles, 0, "Maximum number of files"); 1605 1606 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 1607 &nfiles, 0, "System-wide number of open files"); 1608 1609 static void 1610 fildesc_drvinit(void *unused) 1611 { 1612 dev_t dev; 1613 1614 dev = make_dev(&fildesc_cdevsw, 0, UID_BIN, GID_BIN, 0666, "fd/0"); 1615 make_dev_alias(dev, "stdin"); 1616 dev = make_dev(&fildesc_cdevsw, 1, UID_BIN, GID_BIN, 0666, "fd/1"); 1617 make_dev_alias(dev, "stdout"); 1618 dev = make_dev(&fildesc_cdevsw, 2, UID_BIN, GID_BIN, 0666, "fd/2"); 1619 make_dev_alias(dev, "stderr"); 1620 if (!devfs_present) { 1621 int fd; 1622 1623 for (fd = 3; fd < NUMFDESC; fd++) 1624 make_dev(&fildesc_cdevsw, fd, UID_BIN, GID_BIN, 0666, 1625 "fd/%d", fd); 1626 } 1627 } 1628 1629 struct fileops badfileops = { 1630 badfo_readwrite, 1631 badfo_readwrite, 1632 badfo_ioctl, 1633 badfo_poll, 1634 badfo_kqfilter, 1635 badfo_stat, 1636 badfo_close 1637 }; 1638 1639 static int 1640 badfo_readwrite(fp, uio, cred, flags, td) 1641 struct file *fp; 1642 struct uio *uio; 1643 struct ucred *cred; 1644 struct thread *td; 1645 int flags; 1646 { 1647 1648 return (EBADF); 1649 } 1650 1651 static int 1652 badfo_ioctl(fp, com, data, td) 1653 struct file *fp; 1654 u_long com; 1655 caddr_t data; 1656 struct thread *td; 1657 { 1658 1659 return (EBADF); 1660 } 1661 1662 static int 1663 badfo_poll(fp, events, cred, td) 1664 struct file *fp; 1665 int events; 1666 struct ucred *cred; 1667 struct thread *td; 1668 { 1669 1670 return (0); 1671 } 1672 1673 static int 1674 badfo_kqfilter(fp, kn) 1675 struct file *fp; 1676 struct knote *kn; 1677 { 1678 1679 return (0); 1680 } 1681 1682 static int 1683 badfo_stat(fp, sb, td) 1684 struct file *fp; 1685 struct stat *sb; 1686 struct thread *td; 1687 { 1688 1689 return (EBADF); 1690 } 1691 1692 static int 1693 badfo_close(fp, td) 1694 struct file *fp; 1695 struct thread *td; 1696 { 1697 1698 return (EBADF); 1699 } 1700 1701 SYSINIT(fildescdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR, 1702 fildesc_drvinit,NULL) 1703