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: src/sys/kern/kern_descrip.c,v 1.81.2.17 2003/06/06 20:21:32 tegge Exp $ 40 * $DragonFly: src/sys/kern/kern_descrip.c,v 1.11 2003/07/30 00:19:14 dillon Exp $ 41 */ 42 43 #include "opt_compat.h" 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/malloc.h> 47 #include <sys/sysproto.h> 48 #include <sys/conf.h> 49 #include <sys/filedesc.h> 50 #include <sys/kernel.h> 51 #include <sys/sysctl.h> 52 #include <sys/vnode.h> 53 #include <sys/proc.h> 54 #include <sys/namei.h> 55 #include <sys/file.h> 56 #include <sys/stat.h> 57 #include <sys/filio.h> 58 #include <sys/fcntl.h> 59 #include <sys/unistd.h> 60 #include <sys/resourcevar.h> 61 #include <sys/event.h> 62 63 #include <vm/vm.h> 64 #include <vm/vm_extern.h> 65 66 #include <sys/file2.h> 67 68 static MALLOC_DEFINE(M_FILEDESC, "file desc", "Open file descriptor table"); 69 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "file desc to leader", 70 "file desc to leader structures"); 71 MALLOC_DEFINE(M_FILE, "file", "Open file structure"); 72 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 73 74 static d_open_t fdopen; 75 #define NUMFDESC 64 76 77 #define CDEV_MAJOR 22 78 static struct cdevsw fildesc_cdevsw = { 79 /* name */ "FD", 80 /* maj */ CDEV_MAJOR, 81 /* flags */ 0, 82 /* port */ NULL, 83 /* autoq */ 0, 84 85 /* open */ fdopen, 86 /* close */ noclose, 87 /* read */ noread, 88 /* write */ nowrite, 89 /* ioctl */ noioctl, 90 /* poll */ nopoll, 91 /* mmap */ nommap, 92 /* strategy */ nostrategy, 93 /* dump */ nodump, 94 /* psize */ nopsize 95 }; 96 97 static int do_dup __P((struct filedesc *fdp, int old, int new, register_t *retval, struct proc *p)); 98 static int badfo_readwrite __P((struct file *fp, struct uio *uio, 99 struct ucred *cred, int flags, struct thread *td)); 100 static int badfo_ioctl __P((struct file *fp, u_long com, caddr_t data, 101 struct thread *td)); 102 static int badfo_poll __P((struct file *fp, int events, 103 struct ucred *cred, struct thread *td)); 104 static int badfo_kqfilter __P((struct file *fp, struct knote *kn)); 105 static int badfo_stat __P((struct file *fp, struct stat *sb, struct thread *td)); 106 static int badfo_close __P((struct file *fp, struct thread *td)); 107 108 /* 109 * Descriptor management. 110 */ 111 struct filelist filehead; /* head of list of open files */ 112 int nfiles; /* actual number of open files */ 113 extern int cmask; 114 115 /* 116 * System calls on descriptors. 117 */ 118 /* ARGSUSED */ 119 int 120 getdtablesize(struct getdtablesize_args *uap) 121 { 122 struct proc *p = curproc; 123 124 uap->sysmsg_result = 125 min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc); 126 return (0); 127 } 128 129 /* 130 * Duplicate a file descriptor to a particular value. 131 * 132 * note: keep in mind that a potential race condition exists when closing 133 * descriptors from a shared descriptor table (via rfork). 134 */ 135 /* ARGSUSED */ 136 int 137 dup2(struct dup2_args *uap) 138 { 139 struct proc *p = curproc; 140 struct filedesc *fdp = p->p_fd; 141 u_int old = uap->from, new = uap->to; 142 int i, error; 143 144 retry: 145 if (old >= fdp->fd_nfiles || 146 fdp->fd_ofiles[old] == NULL || 147 new >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur || 148 new >= maxfilesperproc) { 149 return (EBADF); 150 } 151 if (old == new) { 152 uap->sysmsg_result = new; 153 return (0); 154 } 155 if (new >= fdp->fd_nfiles) { 156 if ((error = fdalloc(p, new, &i))) 157 return (error); 158 /* 159 * fdalloc() may block, retest everything. 160 */ 161 goto retry; 162 } 163 return (do_dup(fdp, (int)old, (int)new, uap->sysmsg_fds, p)); 164 } 165 166 /* 167 * Duplicate a file descriptor. 168 */ 169 /* ARGSUSED */ 170 int 171 dup(struct dup_args *uap) 172 { 173 struct proc *p = curproc; 174 struct filedesc *fdp; 175 u_int old; 176 int new, error; 177 178 old = uap->fd; 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 (do_dup(fdp, (int)old, new, uap->sysmsg_fds, p)); 185 } 186 187 /* 188 * The file control system call. 189 */ 190 /* ARGSUSED */ 191 int 192 fcntl(struct fcntl_args *uap) 193 { 194 struct thread *td = curthread; 195 struct proc *p = td->td_proc; 196 struct filedesc *fdp = p->p_fd; 197 struct file *fp; 198 char *pop; 199 struct vnode *vp; 200 int i, tmp, error, flg = F_POSIX; 201 struct flock fl; 202 u_int newmin; 203 204 KKASSERT(p); 205 206 if ((unsigned)uap->fd >= fdp->fd_nfiles || 207 (fp = fdp->fd_ofiles[uap->fd]) == NULL) 208 return (EBADF); 209 pop = &fdp->fd_ofileflags[uap->fd]; 210 211 switch (uap->cmd) { 212 case F_DUPFD: 213 newmin = uap->arg; 214 if (newmin >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur || 215 newmin >= maxfilesperproc) 216 return (EINVAL); 217 if ((error = fdalloc(p, newmin, &i))) 218 return (error); 219 return (do_dup(fdp, uap->fd, i, uap->sysmsg_fds, p)); 220 221 case F_GETFD: 222 uap->sysmsg_result = (*pop & UF_EXCLOSE) ? FD_CLOEXEC : 0; 223 return (0); 224 225 case F_SETFD: 226 *pop = (*pop &~ UF_EXCLOSE) | 227 (uap->arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 228 return (0); 229 230 case F_GETFL: 231 uap->sysmsg_result = OFLAGS(fp->f_flag); 232 return (0); 233 234 case F_SETFL: 235 fhold(fp); 236 fp->f_flag &= ~FCNTLFLAGS; 237 fp->f_flag |= FFLAGS(uap->arg & ~O_ACCMODE) & FCNTLFLAGS; 238 tmp = fp->f_flag & FNONBLOCK; 239 error = fo_ioctl(fp, FIONBIO, (caddr_t)&tmp, td); 240 if (error) { 241 fdrop(fp, td); 242 return (error); 243 } 244 tmp = fp->f_flag & FASYNC; 245 error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp, td); 246 if (!error) { 247 fdrop(fp, td); 248 return (0); 249 } 250 fp->f_flag &= ~FNONBLOCK; 251 tmp = 0; 252 (void)fo_ioctl(fp, FIONBIO, (caddr_t)&tmp, td); 253 fdrop(fp, td); 254 return (error); 255 256 case F_GETOWN: 257 fhold(fp); 258 error = fo_ioctl(fp, FIOGETOWN, (caddr_t)uap->sysmsg_fds, td); 259 fdrop(fp, td); 260 return(error); 261 262 case F_SETOWN: 263 fhold(fp); 264 error = fo_ioctl(fp, FIOSETOWN, (caddr_t)&uap->arg, td); 265 fdrop(fp, td); 266 return(error); 267 268 case F_SETLKW: 269 flg |= F_WAIT; 270 /* Fall into F_SETLK */ 271 272 case F_SETLK: 273 if (fp->f_type != DTYPE_VNODE) 274 return (EBADF); 275 vp = (struct vnode *)fp->f_data; 276 277 /* 278 * copyin/lockop may block 279 */ 280 fhold(fp); 281 /* Copy in the lock structure */ 282 error = copyin((caddr_t)(intptr_t)uap->arg, (caddr_t)&fl, 283 sizeof(fl)); 284 if (error) { 285 fdrop(fp, td); 286 return (error); 287 } 288 if (fl.l_whence == SEEK_CUR) 289 fl.l_start += fp->f_offset; 290 291 switch (fl.l_type) { 292 case F_RDLCK: 293 if ((fp->f_flag & FREAD) == 0) { 294 error = EBADF; 295 break; 296 } 297 p->p_leader->p_flag |= P_ADVLOCK; 298 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 299 &fl, flg); 300 break; 301 case F_WRLCK: 302 if ((fp->f_flag & FWRITE) == 0) { 303 error = EBADF; 304 break; 305 } 306 p->p_leader->p_flag |= P_ADVLOCK; 307 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 308 &fl, flg); 309 break; 310 case F_UNLCK: 311 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 312 &fl, F_POSIX); 313 break; 314 default: 315 error = EINVAL; 316 break; 317 } 318 /* Check for race with close */ 319 if ((unsigned) uap->fd >= fdp->fd_nfiles || 320 fp != fdp->fd_ofiles[uap->fd]) { 321 fl.l_whence = SEEK_SET; 322 fl.l_start = 0; 323 fl.l_len = 0; 324 fl.l_type = F_UNLCK; 325 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 326 F_UNLCK, &fl, F_POSIX); 327 } 328 fdrop(fp, td); 329 return(error); 330 331 case F_GETLK: 332 if (fp->f_type != DTYPE_VNODE) 333 return (EBADF); 334 vp = (struct vnode *)fp->f_data; 335 /* 336 * copyin/lockop may block 337 */ 338 fhold(fp); 339 /* Copy in the lock structure */ 340 error = copyin((caddr_t)(intptr_t)uap->arg, (caddr_t)&fl, 341 sizeof(fl)); 342 if (error) { 343 fdrop(fp, td); 344 return (error); 345 } 346 if (fl.l_type != F_RDLCK && fl.l_type != F_WRLCK && 347 fl.l_type != F_UNLCK) { 348 fdrop(fp, td); 349 return (EINVAL); 350 } 351 if (fl.l_whence == SEEK_CUR) 352 fl.l_start += fp->f_offset; 353 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, 354 &fl, F_POSIX); 355 fdrop(fp, td); 356 if (error == 0) { 357 error = copyout((caddr_t)&fl, 358 (caddr_t)(intptr_t)uap->arg, sizeof(fl)); 359 } 360 return(error); 361 default: 362 return (EINVAL); 363 } 364 /* NOTREACHED */ 365 } 366 367 /* 368 * Common code for dup, dup2, and fcntl(F_DUPFD). 369 */ 370 static int 371 do_dup(fdp, old, new, retval, p) 372 struct filedesc *fdp; 373 int old, new; 374 register_t *retval; 375 struct proc *p; 376 { 377 struct thread *td = p->p_thread; 378 struct file *fp; 379 struct file *delfp; 380 int holdleaders; 381 382 /* 383 * Save info on the descriptor being overwritten. We have 384 * to do the unmap now, but we cannot close it without 385 * introducing an ownership race for the slot. 386 */ 387 delfp = fdp->fd_ofiles[new]; 388 if (delfp != NULL && p->p_fdtol != NULL) { 389 /* 390 * Ask fdfree() to sleep to ensure that all relevant 391 * process leaders can be traversed in closef(). 392 */ 393 fdp->fd_holdleaderscount++; 394 holdleaders = 1; 395 } else 396 holdleaders = 0; 397 #if 0 398 if (delfp && (fdp->fd_ofileflags[new] & UF_MAPPED)) 399 (void) munmapfd(p, new); 400 #endif 401 402 /* 403 * Duplicate the source descriptor, update lastfile 404 */ 405 fp = fdp->fd_ofiles[old]; 406 fdp->fd_ofiles[new] = fp; 407 fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] &~ UF_EXCLOSE; 408 fhold(fp); 409 if (new > fdp->fd_lastfile) 410 fdp->fd_lastfile = new; 411 *retval = new; 412 413 /* 414 * If we dup'd over a valid file, we now own the reference to it 415 * and must dispose of it using closef() semantics (as if a 416 * close() were performed on it). 417 */ 418 if (delfp) { 419 (void) closef(delfp, td); 420 if (holdleaders) { 421 fdp->fd_holdleaderscount--; 422 if (fdp->fd_holdleaderscount == 0 && 423 fdp->fd_holdleaderswakeup != 0) { 424 fdp->fd_holdleaderswakeup = 0; 425 wakeup(&fdp->fd_holdleaderscount); 426 } 427 } 428 } 429 return (0); 430 } 431 432 /* 433 * If sigio is on the list associated with a process or process group, 434 * disable signalling from the device, remove sigio from the list and 435 * free sigio. 436 */ 437 void 438 funsetown(sigio) 439 struct sigio *sigio; 440 { 441 int s; 442 443 if (sigio == NULL) 444 return; 445 s = splhigh(); 446 *(sigio->sio_myref) = NULL; 447 splx(s); 448 if (sigio->sio_pgid < 0) { 449 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 450 sigio, sio_pgsigio); 451 } else /* if ((*sigiop)->sio_pgid > 0) */ { 452 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 453 sigio, sio_pgsigio); 454 } 455 crfree(sigio->sio_ucred); 456 FREE(sigio, M_SIGIO); 457 } 458 459 /* Free a list of sigio structures. */ 460 void 461 funsetownlst(sigiolst) 462 struct sigiolst *sigiolst; 463 { 464 struct sigio *sigio; 465 466 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) 467 funsetown(sigio); 468 } 469 470 /* 471 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 472 * 473 * After permission checking, add a sigio structure to the sigio list for 474 * the process or process group. 475 */ 476 int 477 fsetown(pgid, sigiop) 478 pid_t pgid; 479 struct sigio **sigiop; 480 { 481 struct proc *proc; 482 struct pgrp *pgrp; 483 struct sigio *sigio; 484 int s; 485 486 if (pgid == 0) { 487 funsetown(*sigiop); 488 return (0); 489 } 490 if (pgid > 0) { 491 proc = pfind(pgid); 492 if (proc == NULL) 493 return (ESRCH); 494 495 /* 496 * Policy - Don't allow a process to FSETOWN a process 497 * in another session. 498 * 499 * Remove this test to allow maximum flexibility or 500 * restrict FSETOWN to the current process or process 501 * group for maximum safety. 502 */ 503 if (proc->p_session != curproc->p_session) 504 return (EPERM); 505 506 pgrp = NULL; 507 } else /* if (pgid < 0) */ { 508 pgrp = pgfind(-pgid); 509 if (pgrp == NULL) 510 return (ESRCH); 511 512 /* 513 * Policy - Don't allow a process to FSETOWN a process 514 * in another session. 515 * 516 * Remove this test to allow maximum flexibility or 517 * restrict FSETOWN to the current process or process 518 * group for maximum safety. 519 */ 520 if (pgrp->pg_session != curproc->p_session) 521 return (EPERM); 522 523 proc = NULL; 524 } 525 funsetown(*sigiop); 526 MALLOC(sigio, struct sigio *, sizeof(struct sigio), M_SIGIO, M_WAITOK); 527 if (pgid > 0) { 528 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 529 sigio->sio_proc = proc; 530 } else { 531 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 532 sigio->sio_pgrp = pgrp; 533 } 534 sigio->sio_pgid = pgid; 535 sigio->sio_ucred = crhold(curproc->p_ucred); 536 /* It would be convenient if p_ruid was in ucred. */ 537 sigio->sio_ruid = curproc->p_ucred->cr_ruid; 538 sigio->sio_myref = sigiop; 539 s = splhigh(); 540 *sigiop = sigio; 541 splx(s); 542 return (0); 543 } 544 545 /* 546 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 547 */ 548 pid_t 549 fgetown(sigio) 550 struct sigio *sigio; 551 { 552 return (sigio != NULL ? sigio->sio_pgid : 0); 553 } 554 555 /* 556 * Close a file descriptor. 557 */ 558 /* ARGSUSED */ 559 int 560 close(struct close_args *uap) 561 { 562 struct thread *td = curthread; 563 struct proc *p = td->td_proc; 564 struct filedesc *fdp; 565 struct file *fp; 566 int fd = uap->fd; 567 int error; 568 int holdleaders; 569 570 KKASSERT(p); 571 fdp = p->p_fd; 572 573 if ((unsigned)fd >= fdp->fd_nfiles || 574 (fp = fdp->fd_ofiles[fd]) == NULL) 575 return (EBADF); 576 #if 0 577 if (fdp->fd_ofileflags[fd] & UF_MAPPED) 578 (void) munmapfd(p, fd); 579 #endif 580 fdp->fd_ofiles[fd] = NULL; 581 fdp->fd_ofileflags[fd] = 0; 582 holdleaders = 0; 583 if (p->p_fdtol != NULL) { 584 /* 585 * Ask fdfree() to sleep to ensure that all relevant 586 * process leaders can be traversed in closef(). 587 */ 588 fdp->fd_holdleaderscount++; 589 holdleaders = 1; 590 } 591 592 /* 593 * we now hold the fp reference that used to be owned by the descriptor 594 * array. 595 */ 596 while (fdp->fd_lastfile > 0 && fdp->fd_ofiles[fdp->fd_lastfile] == NULL) 597 fdp->fd_lastfile--; 598 if (fd < fdp->fd_freefile) 599 fdp->fd_freefile = fd; 600 if (fd < fdp->fd_knlistsize) 601 knote_fdclose(p, fd); 602 error = closef(fp, td); 603 if (holdleaders) { 604 fdp->fd_holdleaderscount--; 605 if (fdp->fd_holdleaderscount == 0 && 606 fdp->fd_holdleaderswakeup != 0) { 607 fdp->fd_holdleaderswakeup = 0; 608 wakeup(&fdp->fd_holdleaderscount); 609 } 610 } 611 return (error); 612 } 613 614 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 615 /* 616 * Return status information about a file descriptor. 617 */ 618 /* ARGSUSED */ 619 int 620 ofstat(struct ofstat_args *uap) 621 { 622 struct thread *td = curthread; 623 struct proc *p = td->td_proc; 624 struct filedesc *fdp; 625 struct file *fp; 626 struct stat ub; 627 struct ostat oub; 628 int error; 629 630 KKASSERT(p); 631 fdp = p->p_fd; 632 if ((unsigned)uap->fd >= fdp->fd_nfiles || 633 (fp = fdp->fd_ofiles[uap->fd]) == NULL) 634 return (EBADF); 635 fhold(fp); 636 error = fo_stat(fp, &ub, td); 637 if (error == 0) { 638 cvtstat(&ub, &oub); 639 error = copyout((caddr_t)&oub, (caddr_t)uap->sb, sizeof (oub)); 640 } 641 fdrop(fp, td); 642 return (error); 643 } 644 #endif /* COMPAT_43 || COMPAT_SUNOS */ 645 646 /* 647 * Return status information about a file descriptor. 648 */ 649 /* ARGSUSED */ 650 int 651 fstat(struct fstat_args *uap) 652 { 653 struct thread *td = curthread; 654 struct proc *p = td->td_proc; 655 struct filedesc *fdp = p->p_fd; 656 struct file *fp; 657 struct stat ub; 658 int error; 659 660 KKASSERT(p); 661 fdp = p->p_fd; 662 if ((unsigned)uap->fd >= fdp->fd_nfiles || 663 (fp = fdp->fd_ofiles[uap->fd]) == NULL) 664 return (EBADF); 665 fhold(fp); 666 error = fo_stat(fp, &ub, td); 667 if (error == 0) 668 error = copyout((caddr_t)&ub, (caddr_t)uap->sb, sizeof (ub)); 669 fdrop(fp, td); 670 return (error); 671 } 672 673 /* 674 * Return status information about a file descriptor. 675 */ 676 /* ARGSUSED */ 677 int 678 nfstat(struct nfstat_args *uap) 679 { 680 struct thread *td = curthread; 681 struct proc *p = td->td_proc; 682 struct filedesc *fdp; 683 struct file *fp; 684 struct stat ub; 685 struct nstat nub; 686 int error; 687 688 KKASSERT(p); 689 fdp = p->p_fd; 690 if ((unsigned)uap->fd >= fdp->fd_nfiles || 691 (fp = fdp->fd_ofiles[uap->fd]) == NULL) 692 return (EBADF); 693 fhold(fp); 694 error = fo_stat(fp, &ub, td); 695 if (error == 0) { 696 cvtnstat(&ub, &nub); 697 error = copyout((caddr_t)&nub, (caddr_t)uap->sb, sizeof (nub)); 698 } 699 fdrop(fp, td); 700 return (error); 701 } 702 703 /* 704 * Return pathconf information about a file descriptor. 705 */ 706 /* ARGSUSED */ 707 int 708 fpathconf(struct fpathconf_args *uap) 709 { 710 struct thread *td = curthread; 711 struct proc *p = td->td_proc; 712 struct filedesc *fdp; 713 struct file *fp; 714 struct vnode *vp; 715 int error = 0; 716 717 KKASSERT(p); 718 fdp = p->p_fd; 719 if ((unsigned)uap->fd >= fdp->fd_nfiles || 720 (fp = fdp->fd_ofiles[uap->fd]) == NULL) 721 return (EBADF); 722 723 fhold(fp); 724 725 switch (fp->f_type) { 726 case DTYPE_PIPE: 727 case DTYPE_SOCKET: 728 if (uap->name != _PC_PIPE_BUF) { 729 error = EINVAL; 730 } else { 731 uap->sysmsg_result = PIPE_BUF; 732 error = 0; 733 } 734 break; 735 case DTYPE_FIFO: 736 case DTYPE_VNODE: 737 vp = (struct vnode *)fp->f_data; 738 error = VOP_PATHCONF(vp, uap->name, uap->sysmsg_fds); 739 break; 740 default: 741 error = EOPNOTSUPP; 742 break; 743 } 744 fdrop(fp, td); 745 return(error); 746 } 747 748 /* 749 * Allocate a file descriptor for the process. 750 */ 751 static int fdexpand; 752 SYSCTL_INT(_debug, OID_AUTO, fdexpand, CTLFLAG_RD, &fdexpand, 0, ""); 753 754 int 755 fdalloc(p, want, result) 756 struct proc *p; 757 int want; 758 int *result; 759 { 760 struct filedesc *fdp = p->p_fd; 761 int i; 762 int lim, last, nfiles; 763 struct file **newofile; 764 char *newofileflags; 765 766 /* 767 * Search for a free descriptor starting at the higher 768 * of want or fd_freefile. If that fails, consider 769 * expanding the ofile array. 770 */ 771 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc); 772 for (;;) { 773 last = min(fdp->fd_nfiles, lim); 774 if ((i = want) < fdp->fd_freefile) 775 i = fdp->fd_freefile; 776 for (; i < last; i++) { 777 if (fdp->fd_ofiles[i] == NULL) { 778 fdp->fd_ofileflags[i] = 0; 779 if (i > fdp->fd_lastfile) 780 fdp->fd_lastfile = i; 781 if (want <= fdp->fd_freefile) 782 fdp->fd_freefile = i; 783 *result = i; 784 return (0); 785 } 786 } 787 788 /* 789 * No space in current array. Expand? 790 */ 791 if (fdp->fd_nfiles >= lim) 792 return (EMFILE); 793 if (fdp->fd_nfiles < NDEXTENT) 794 nfiles = NDEXTENT; 795 else 796 nfiles = 2 * fdp->fd_nfiles; 797 MALLOC(newofile, struct file **, nfiles * OFILESIZE, 798 M_FILEDESC, M_WAITOK); 799 800 /* 801 * deal with file-table extend race that might have occured 802 * when malloc was blocked. 803 */ 804 if (fdp->fd_nfiles >= nfiles) { 805 FREE(newofile, M_FILEDESC); 806 continue; 807 } 808 newofileflags = (char *) &newofile[nfiles]; 809 /* 810 * Copy the existing ofile and ofileflags arrays 811 * and zero the new portion of each array. 812 */ 813 bcopy(fdp->fd_ofiles, newofile, 814 (i = sizeof(struct file *) * fdp->fd_nfiles)); 815 bzero((char *)newofile + i, nfiles * sizeof(struct file *) - i); 816 bcopy(fdp->fd_ofileflags, newofileflags, 817 (i = sizeof(char) * fdp->fd_nfiles)); 818 bzero(newofileflags + i, nfiles * sizeof(char) - i); 819 if (fdp->fd_nfiles > NDFILE) 820 FREE(fdp->fd_ofiles, M_FILEDESC); 821 fdp->fd_ofiles = newofile; 822 fdp->fd_ofileflags = newofileflags; 823 fdp->fd_nfiles = nfiles; 824 fdexpand++; 825 } 826 return (0); 827 } 828 829 /* 830 * Check to see whether n user file descriptors 831 * are available to the process p. 832 */ 833 int 834 fdavail(p, n) 835 struct proc *p; 836 int n; 837 { 838 struct filedesc *fdp = p->p_fd; 839 struct file **fpp; 840 int i, lim, last; 841 842 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc); 843 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) 844 return (1); 845 846 last = min(fdp->fd_nfiles, lim); 847 fpp = &fdp->fd_ofiles[fdp->fd_freefile]; 848 for (i = last - fdp->fd_freefile; --i >= 0; fpp++) { 849 if (*fpp == NULL && --n <= 0) 850 return (1); 851 } 852 return (0); 853 } 854 855 /* 856 * Create a new open file structure and allocate 857 * a file decriptor for the process that refers to it. 858 */ 859 int 860 falloc(p, resultfp, resultfd) 861 struct proc *p; 862 struct file **resultfp; 863 int *resultfd; 864 { 865 struct file *fp, *fq; 866 int error, i; 867 868 if (nfiles >= maxfiles) { 869 tablefull("file"); 870 return (ENFILE); 871 } 872 /* 873 * Allocate a new file descriptor. 874 * If the process has file descriptor zero open, add to the list 875 * of open files at that point, otherwise put it at the front of 876 * the list of open files. 877 */ 878 nfiles++; 879 MALLOC(fp, struct file *, sizeof(struct file), M_FILE, M_WAITOK); 880 bzero(fp, sizeof(struct file)); 881 882 /* 883 * wait until after malloc (which may have blocked) returns before 884 * allocating the slot, else a race might have shrunk it if we had 885 * allocated it before the malloc. 886 */ 887 if ((error = fdalloc(p, 0, &i))) { 888 nfiles--; 889 FREE(fp, M_FILE); 890 return (error); 891 } 892 fp->f_count = 1; 893 fp->f_cred = crhold(p->p_ucred); 894 fp->f_ops = &badfileops; 895 fp->f_seqcount = 1; 896 if ((fq = p->p_fd->fd_ofiles[0])) { 897 LIST_INSERT_AFTER(fq, fp, f_list); 898 } else { 899 LIST_INSERT_HEAD(&filehead, fp, f_list); 900 } 901 p->p_fd->fd_ofiles[i] = fp; 902 if (resultfp) 903 *resultfp = fp; 904 if (resultfd) 905 *resultfd = i; 906 return (0); 907 } 908 909 /* 910 * Free a file descriptor. 911 */ 912 void 913 ffree(fp) 914 struct file *fp; 915 { 916 KASSERT((fp->f_count == 0), ("ffree: fp_fcount not 0!")); 917 LIST_REMOVE(fp, f_list); 918 crfree(fp->f_cred); 919 nfiles--; 920 FREE(fp, M_FILE); 921 } 922 923 /* 924 * Build a new filedesc structure. 925 */ 926 struct filedesc * 927 fdinit(p) 928 struct proc *p; 929 { 930 struct filedesc0 *newfdp; 931 struct filedesc *fdp = p->p_fd; 932 933 MALLOC(newfdp, struct filedesc0 *, sizeof(struct filedesc0), 934 M_FILEDESC, M_WAITOK); 935 bzero(newfdp, sizeof(struct filedesc0)); 936 newfdp->fd_fd.fd_cdir = fdp->fd_cdir; 937 if (newfdp->fd_fd.fd_cdir) 938 VREF(newfdp->fd_fd.fd_cdir); 939 newfdp->fd_fd.fd_rdir = fdp->fd_rdir; 940 if (newfdp->fd_fd.fd_rdir) 941 VREF(newfdp->fd_fd.fd_rdir); 942 newfdp->fd_fd.fd_jdir = fdp->fd_jdir; 943 if (newfdp->fd_fd.fd_jdir) 944 VREF(newfdp->fd_fd.fd_jdir); 945 946 /* Create the file descriptor table. */ 947 newfdp->fd_fd.fd_refcnt = 1; 948 newfdp->fd_fd.fd_cmask = cmask; 949 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles; 950 newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags; 951 newfdp->fd_fd.fd_nfiles = NDFILE; 952 newfdp->fd_fd.fd_knlistsize = -1; 953 954 return (&newfdp->fd_fd); 955 } 956 957 /* 958 * Share a filedesc structure. 959 */ 960 struct filedesc * 961 fdshare(p) 962 struct proc *p; 963 { 964 p->p_fd->fd_refcnt++; 965 return (p->p_fd); 966 } 967 968 /* 969 * Copy a filedesc structure. 970 */ 971 struct filedesc * 972 fdcopy(p) 973 struct proc *p; 974 { 975 struct filedesc *newfdp, *fdp = p->p_fd; 976 struct file **fpp; 977 int i; 978 979 /* Certain daemons might not have file descriptors. */ 980 if (fdp == NULL) 981 return (NULL); 982 983 MALLOC(newfdp, struct filedesc *, sizeof(struct filedesc0), 984 M_FILEDESC, M_WAITOK); 985 bcopy(fdp, newfdp, sizeof(struct filedesc)); 986 if (newfdp->fd_cdir) 987 VREF(newfdp->fd_cdir); 988 if (newfdp->fd_rdir) 989 VREF(newfdp->fd_rdir); 990 if (newfdp->fd_jdir) 991 VREF(newfdp->fd_jdir); 992 newfdp->fd_refcnt = 1; 993 994 /* 995 * If the number of open files fits in the internal arrays 996 * of the open file structure, use them, otherwise allocate 997 * additional memory for the number of descriptors currently 998 * in use. 999 */ 1000 if (newfdp->fd_lastfile < NDFILE) { 1001 newfdp->fd_ofiles = ((struct filedesc0 *) newfdp)->fd_dfiles; 1002 newfdp->fd_ofileflags = 1003 ((struct filedesc0 *) newfdp)->fd_dfileflags; 1004 i = NDFILE; 1005 } else { 1006 /* 1007 * Compute the smallest multiple of NDEXTENT needed 1008 * for the file descriptors currently in use, 1009 * allowing the table to shrink. 1010 */ 1011 i = newfdp->fd_nfiles; 1012 while (i > 2 * NDEXTENT && i > newfdp->fd_lastfile * 2) 1013 i /= 2; 1014 MALLOC(newfdp->fd_ofiles, struct file **, i * OFILESIZE, 1015 M_FILEDESC, M_WAITOK); 1016 newfdp->fd_ofileflags = (char *) &newfdp->fd_ofiles[i]; 1017 } 1018 newfdp->fd_nfiles = i; 1019 bcopy(fdp->fd_ofiles, newfdp->fd_ofiles, i * sizeof(struct file **)); 1020 bcopy(fdp->fd_ofileflags, newfdp->fd_ofileflags, i * sizeof(char)); 1021 1022 /* 1023 * kq descriptors cannot be copied. 1024 */ 1025 if (newfdp->fd_knlistsize != -1) { 1026 fpp = &newfdp->fd_ofiles[newfdp->fd_lastfile]; 1027 for (i = newfdp->fd_lastfile; i >= 0; i--, fpp--) { 1028 if (*fpp != NULL && (*fpp)->f_type == DTYPE_KQUEUE) { 1029 *fpp = NULL; 1030 if (i < newfdp->fd_freefile) 1031 newfdp->fd_freefile = i; 1032 } 1033 if (*fpp == NULL && i == newfdp->fd_lastfile && i > 0) 1034 newfdp->fd_lastfile--; 1035 } 1036 newfdp->fd_knlist = NULL; 1037 newfdp->fd_knlistsize = -1; 1038 newfdp->fd_knhash = NULL; 1039 newfdp->fd_knhashmask = 0; 1040 } 1041 1042 fpp = newfdp->fd_ofiles; 1043 for (i = newfdp->fd_lastfile; i-- >= 0; fpp++) { 1044 if (*fpp != NULL) 1045 fhold(*fpp); 1046 } 1047 return (newfdp); 1048 } 1049 1050 /* 1051 * Release a filedesc structure. 1052 */ 1053 void 1054 fdfree(struct proc *p) 1055 { 1056 struct thread *td = p->p_thread; 1057 struct filedesc *fdp = p->p_fd; 1058 struct file **fpp; 1059 int i; 1060 struct filedesc_to_leader *fdtol; 1061 struct file *fp; 1062 struct vnode *vp; 1063 struct flock lf; 1064 1065 /* Certain daemons might not have file descriptors. */ 1066 if (fdp == NULL) 1067 return; 1068 1069 /* Check for special need to clear POSIX style locks */ 1070 fdtol = p->p_fdtol; 1071 if (fdtol != NULL) { 1072 KASSERT(fdtol->fdl_refcount > 0, 1073 ("filedesc_to_refcount botch: fdl_refcount=%d", 1074 fdtol->fdl_refcount)); 1075 if (fdtol->fdl_refcount == 1 && 1076 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 1077 i = 0; 1078 fpp = fdp->fd_ofiles; 1079 for (i = 0, fpp = fdp->fd_ofiles; 1080 i < fdp->fd_lastfile; 1081 i++, fpp++) { 1082 if (*fpp == NULL || 1083 (*fpp)->f_type != DTYPE_VNODE) 1084 continue; 1085 fp = *fpp; 1086 fhold(fp); 1087 lf.l_whence = SEEK_SET; 1088 lf.l_start = 0; 1089 lf.l_len = 0; 1090 lf.l_type = F_UNLCK; 1091 vp = (struct vnode *)fp->f_data; 1092 (void) VOP_ADVLOCK(vp, 1093 (caddr_t)p->p_leader, 1094 F_UNLCK, 1095 &lf, 1096 F_POSIX); 1097 fdrop(fp, p->p_thread); 1098 fpp = fdp->fd_ofiles + i; 1099 } 1100 } 1101 retry: 1102 if (fdtol->fdl_refcount == 1) { 1103 if (fdp->fd_holdleaderscount > 0 && 1104 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 1105 /* 1106 * close() or do_dup() has cleared a reference 1107 * in a shared file descriptor table. 1108 */ 1109 fdp->fd_holdleaderswakeup = 1; 1110 tsleep(&fdp->fd_holdleaderscount, 1111 0, "fdlhold", 0); 1112 goto retry; 1113 } 1114 if (fdtol->fdl_holdcount > 0) { 1115 /* 1116 * Ensure that fdtol->fdl_leader 1117 * remains valid in closef(). 1118 */ 1119 fdtol->fdl_wakeup = 1; 1120 tsleep(fdtol, 0, "fdlhold", 0); 1121 goto retry; 1122 } 1123 } 1124 fdtol->fdl_refcount--; 1125 if (fdtol->fdl_refcount == 0 && 1126 fdtol->fdl_holdcount == 0) { 1127 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 1128 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 1129 } else 1130 fdtol = NULL; 1131 p->p_fdtol = NULL; 1132 if (fdtol != NULL) 1133 FREE(fdtol, M_FILEDESC_TO_LEADER); 1134 } 1135 if (--fdp->fd_refcnt > 0) 1136 return; 1137 /* 1138 * we are the last reference to the structure, we can 1139 * safely assume it will not change out from under us. 1140 */ 1141 fpp = fdp->fd_ofiles; 1142 for (i = fdp->fd_lastfile; i-- >= 0; fpp++) { 1143 if (*fpp) 1144 (void) closef(*fpp, td); 1145 } 1146 if (fdp->fd_nfiles > NDFILE) 1147 FREE(fdp->fd_ofiles, M_FILEDESC); 1148 if (fdp->fd_cdir) 1149 vrele(fdp->fd_cdir); 1150 if (fdp->fd_rdir) 1151 vrele(fdp->fd_rdir); 1152 if (fdp->fd_jdir) 1153 vrele(fdp->fd_jdir); 1154 if (fdp->fd_knlist) 1155 FREE(fdp->fd_knlist, M_KQUEUE); 1156 if (fdp->fd_knhash) 1157 FREE(fdp->fd_knhash, M_KQUEUE); 1158 FREE(fdp, M_FILEDESC); 1159 } 1160 1161 /* 1162 * For setugid programs, we don't want to people to use that setugidness 1163 * to generate error messages which write to a file which otherwise would 1164 * otherwise be off-limits to the process. 1165 * 1166 * This is a gross hack to plug the hole. A better solution would involve 1167 * a special vop or other form of generalized access control mechanism. We 1168 * go ahead and just reject all procfs file systems accesses as dangerous. 1169 * 1170 * Since setugidsafety calls this only for fd 0, 1 and 2, this check is 1171 * sufficient. We also don't for check setugidness since we know we are. 1172 */ 1173 static int 1174 is_unsafe(struct file *fp) 1175 { 1176 if (fp->f_type == DTYPE_VNODE && 1177 ((struct vnode *)(fp->f_data))->v_tag == VT_PROCFS) 1178 return (1); 1179 return (0); 1180 } 1181 1182 /* 1183 * Make this setguid thing safe, if at all possible. 1184 */ 1185 void 1186 setugidsafety(struct proc *p) 1187 { 1188 struct thread *td = p->p_thread; 1189 struct filedesc *fdp = p->p_fd; 1190 int i; 1191 1192 /* Certain daemons might not have file descriptors. */ 1193 if (fdp == NULL) 1194 return; 1195 1196 /* 1197 * note: fdp->fd_ofiles may be reallocated out from under us while 1198 * we are blocked in a close. Be careful! 1199 */ 1200 for (i = 0; i <= fdp->fd_lastfile; i++) { 1201 if (i > 2) 1202 break; 1203 if (fdp->fd_ofiles[i] && is_unsafe(fdp->fd_ofiles[i])) { 1204 struct file *fp; 1205 1206 #if 0 1207 if ((fdp->fd_ofileflags[i] & UF_MAPPED) != 0) 1208 (void) munmapfd(p, i); 1209 #endif 1210 if (i < fdp->fd_knlistsize) 1211 knote_fdclose(p, i); 1212 /* 1213 * NULL-out descriptor prior to close to avoid 1214 * a race while close blocks. 1215 */ 1216 fp = fdp->fd_ofiles[i]; 1217 fdp->fd_ofiles[i] = NULL; 1218 fdp->fd_ofileflags[i] = 0; 1219 if (i < fdp->fd_freefile) 1220 fdp->fd_freefile = i; 1221 (void) closef(fp, td); 1222 } 1223 } 1224 while (fdp->fd_lastfile > 0 && fdp->fd_ofiles[fdp->fd_lastfile] == NULL) 1225 fdp->fd_lastfile--; 1226 } 1227 1228 /* 1229 * Close any files on exec? 1230 */ 1231 void 1232 fdcloseexec(struct proc *p) 1233 { 1234 struct thread *td = p->p_thread; 1235 struct filedesc *fdp = p->p_fd; 1236 int i; 1237 1238 /* Certain daemons might not have file descriptors. */ 1239 if (fdp == NULL) 1240 return; 1241 1242 /* 1243 * We cannot cache fd_ofiles or fd_ofileflags since operations 1244 * may block and rip them out from under us. 1245 */ 1246 for (i = 0; i <= fdp->fd_lastfile; i++) { 1247 if (fdp->fd_ofiles[i] != NULL && 1248 (fdp->fd_ofileflags[i] & UF_EXCLOSE)) { 1249 struct file *fp; 1250 1251 #if 0 1252 if (fdp->fd_ofileflags[i] & UF_MAPPED) 1253 (void) munmapfd(p, i); 1254 #endif 1255 if (i < fdp->fd_knlistsize) 1256 knote_fdclose(p, i); 1257 /* 1258 * NULL-out descriptor prior to close to avoid 1259 * a race while close blocks. 1260 */ 1261 fp = fdp->fd_ofiles[i]; 1262 fdp->fd_ofiles[i] = NULL; 1263 fdp->fd_ofileflags[i] = 0; 1264 if (i < fdp->fd_freefile) 1265 fdp->fd_freefile = i; 1266 (void) closef(fp, td); 1267 } 1268 } 1269 while (fdp->fd_lastfile > 0 && fdp->fd_ofiles[fdp->fd_lastfile] == NULL) 1270 fdp->fd_lastfile--; 1271 } 1272 1273 /* 1274 * It is unsafe for set[ug]id processes to be started with file 1275 * descriptors 0..2 closed, as these descriptors are given implicit 1276 * significance in the Standard C library. fdcheckstd() will create a 1277 * descriptor referencing /dev/null for each of stdin, stdout, and 1278 * stderr that is not already open. 1279 */ 1280 int 1281 fdcheckstd(struct proc *p) 1282 { 1283 struct thread *td = p->p_thread; 1284 struct nameidata nd; 1285 struct filedesc *fdp; 1286 struct file *fp; 1287 register_t retval; 1288 int fd, i, error, flags, devnull; 1289 1290 fdp = p->p_fd; 1291 if (fdp == NULL) 1292 return (0); 1293 devnull = -1; 1294 error = 0; 1295 for (i = 0; i < 3; i++) { 1296 if (fdp->fd_ofiles[i] != NULL) 1297 continue; 1298 if (devnull < 0) { 1299 error = falloc(p, &fp, &fd); 1300 if (error != 0) 1301 break; 1302 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, 1303 "/dev/null", td); 1304 flags = FREAD | FWRITE; 1305 error = vn_open(&nd, flags, 0); 1306 if (error != 0) { 1307 fdp->fd_ofiles[i] = NULL; 1308 fdrop(fp, td); 1309 break; 1310 } 1311 NDFREE(&nd, NDF_ONLY_PNBUF); 1312 fp->f_data = (caddr_t)nd.ni_vp; 1313 fp->f_flag = flags; 1314 fp->f_ops = &vnops; 1315 fp->f_type = DTYPE_VNODE; 1316 VOP_UNLOCK(nd.ni_vp, 0, td); 1317 devnull = fd; 1318 } else { 1319 error = fdalloc(p, 0, &fd); 1320 if (error != 0) 1321 break; 1322 error = do_dup(fdp, devnull, fd, &retval, p); 1323 if (error != 0) 1324 break; 1325 } 1326 } 1327 return (error); 1328 } 1329 1330 /* 1331 * Internal form of close. 1332 * Decrement reference count on file structure. 1333 * Note: td and/or p may be NULL when closing a file 1334 * that was being passed in a message. 1335 */ 1336 int 1337 closef(struct file *fp, struct thread *td) 1338 { 1339 struct vnode *vp; 1340 struct flock lf; 1341 struct filedesc_to_leader *fdtol; 1342 struct proc *p; 1343 1344 if (fp == NULL) 1345 return (0); 1346 if (td == NULL) { 1347 td = curthread; 1348 p = NULL; /* allow no proc association */ 1349 } else { 1350 p = td->td_proc; /* can also be NULL */ 1351 } 1352 /* 1353 * POSIX record locking dictates that any close releases ALL 1354 * locks owned by this process. This is handled by setting 1355 * a flag in the unlock to free ONLY locks obeying POSIX 1356 * semantics, and not to free BSD-style file locks. 1357 * If the descriptor was in a message, POSIX-style locks 1358 * aren't passed with the descriptor. 1359 */ 1360 if (p != NULL && 1361 fp->f_type == DTYPE_VNODE) { 1362 if ((p->p_leader->p_flag & P_ADVLOCK) != 0) { 1363 lf.l_whence = SEEK_SET; 1364 lf.l_start = 0; 1365 lf.l_len = 0; 1366 lf.l_type = F_UNLCK; 1367 vp = (struct vnode *)fp->f_data; 1368 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 1369 &lf, F_POSIX); 1370 } 1371 fdtol = p->p_fdtol; 1372 if (fdtol != NULL) { 1373 /* 1374 * Handle special case where file descriptor table 1375 * is shared between multiple process leaders. 1376 */ 1377 for (fdtol = fdtol->fdl_next; 1378 fdtol != p->p_fdtol; 1379 fdtol = fdtol->fdl_next) { 1380 if ((fdtol->fdl_leader->p_flag & 1381 P_ADVLOCK) == 0) 1382 continue; 1383 fdtol->fdl_holdcount++; 1384 lf.l_whence = SEEK_SET; 1385 lf.l_start = 0; 1386 lf.l_len = 0; 1387 lf.l_type = F_UNLCK; 1388 vp = (struct vnode *)fp->f_data; 1389 (void) VOP_ADVLOCK(vp, 1390 (caddr_t)p->p_leader, 1391 F_UNLCK, &lf, F_POSIX); 1392 fdtol->fdl_holdcount--; 1393 if (fdtol->fdl_holdcount == 0 && 1394 fdtol->fdl_wakeup != 0) { 1395 fdtol->fdl_wakeup = 0; 1396 wakeup(fdtol); 1397 } 1398 } 1399 } 1400 } 1401 return (fdrop(fp, td)); 1402 } 1403 1404 int 1405 fdrop(struct file *fp, struct thread *td) 1406 { 1407 struct flock lf; 1408 struct vnode *vp; 1409 int error; 1410 1411 if (--fp->f_count > 0) 1412 return (0); 1413 if (fp->f_count < 0) 1414 panic("fdrop: count < 0"); 1415 if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE) { 1416 lf.l_whence = SEEK_SET; 1417 lf.l_start = 0; 1418 lf.l_len = 0; 1419 lf.l_type = F_UNLCK; 1420 vp = (struct vnode *)fp->f_data; 1421 (void) VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 1422 } 1423 if (fp->f_ops != &badfileops) 1424 error = fo_close(fp, td); 1425 else 1426 error = 0; 1427 ffree(fp); 1428 return (error); 1429 } 1430 1431 /* 1432 * Apply an advisory lock on a file descriptor. 1433 * 1434 * Just attempt to get a record lock of the requested type on 1435 * the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0). 1436 */ 1437 /* ARGSUSED */ 1438 int 1439 flock(struct flock_args *uap) 1440 { 1441 struct proc *p = curproc; 1442 struct filedesc *fdp = p->p_fd; 1443 struct file *fp; 1444 struct vnode *vp; 1445 struct flock lf; 1446 1447 if ((unsigned)uap->fd >= fdp->fd_nfiles || 1448 (fp = fdp->fd_ofiles[uap->fd]) == NULL) 1449 return (EBADF); 1450 if (fp->f_type != DTYPE_VNODE) 1451 return (EOPNOTSUPP); 1452 vp = (struct vnode *)fp->f_data; 1453 lf.l_whence = SEEK_SET; 1454 lf.l_start = 0; 1455 lf.l_len = 0; 1456 if (uap->how & LOCK_UN) { 1457 lf.l_type = F_UNLCK; 1458 fp->f_flag &= ~FHASLOCK; 1459 return (VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK)); 1460 } 1461 if (uap->how & LOCK_EX) 1462 lf.l_type = F_WRLCK; 1463 else if (uap->how & LOCK_SH) 1464 lf.l_type = F_RDLCK; 1465 else 1466 return (EBADF); 1467 fp->f_flag |= FHASLOCK; 1468 if (uap->how & LOCK_NB) 1469 return (VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK)); 1470 return (VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK|F_WAIT)); 1471 } 1472 1473 /* 1474 * File Descriptor pseudo-device driver (/dev/fd/). 1475 * 1476 * Opening minor device N dup()s the file (if any) connected to file 1477 * descriptor N belonging to the calling process. Note that this driver 1478 * consists of only the ``open()'' routine, because all subsequent 1479 * references to this file will be direct to the other driver. 1480 */ 1481 /* ARGSUSED */ 1482 static int 1483 fdopen(dev_t dev, int mode, int type, struct thread *td) 1484 { 1485 KKASSERT(td->td_proc != NULL); 1486 1487 /* 1488 * XXX Kludge: set curproc->p_dupfd to contain the value of the 1489 * the file descriptor being sought for duplication. The error 1490 * return ensures that the vnode for this device will be released 1491 * by vn_open. Open will detect this special error and take the 1492 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 1493 * will simply report the error. 1494 */ 1495 td->td_proc->p_dupfd = minor(dev); 1496 return (ENODEV); 1497 } 1498 1499 /* 1500 * Duplicate the specified descriptor to a free descriptor. 1501 */ 1502 int 1503 dupfdopen(struct filedesc *fdp, int indx, int dfd, int mode, int error) 1504 { 1505 struct file *wfp; 1506 struct file *fp; 1507 1508 /* 1509 * If the to-be-dup'd fd number is greater than the allowed number 1510 * of file descriptors, or the fd to be dup'd has already been 1511 * closed, then reject. 1512 */ 1513 if ((u_int)dfd >= fdp->fd_nfiles || 1514 (wfp = fdp->fd_ofiles[dfd]) == NULL) { 1515 return (EBADF); 1516 } 1517 1518 /* 1519 * There are two cases of interest here. 1520 * 1521 * For ENODEV simply dup (dfd) to file descriptor 1522 * (indx) and return. 1523 * 1524 * For ENXIO steal away the file structure from (dfd) and 1525 * store it in (indx). (dfd) is effectively closed by 1526 * this operation. 1527 * 1528 * Any other error code is just returned. 1529 */ 1530 switch (error) { 1531 case ENODEV: 1532 /* 1533 * Check that the mode the file is being opened for is a 1534 * subset of the mode of the existing descriptor. 1535 */ 1536 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) 1537 return (EACCES); 1538 fp = fdp->fd_ofiles[indx]; 1539 #if 0 1540 if (fp && fdp->fd_ofileflags[indx] & UF_MAPPED) 1541 (void) munmapfd(p, indx); 1542 #endif 1543 fdp->fd_ofiles[indx] = wfp; 1544 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 1545 fhold(wfp); 1546 if (indx > fdp->fd_lastfile) 1547 fdp->fd_lastfile = indx; 1548 /* 1549 * we now own the reference to fp that the ofiles[] array 1550 * used to own. Release it. 1551 */ 1552 if (fp) 1553 fdrop(fp, curthread); 1554 return (0); 1555 1556 case ENXIO: 1557 /* 1558 * Steal away the file pointer from dfd, and stuff it into indx. 1559 */ 1560 fp = fdp->fd_ofiles[indx]; 1561 #if 0 1562 if (fp && fdp->fd_ofileflags[indx] & UF_MAPPED) 1563 (void) munmapfd(p, indx); 1564 #endif 1565 fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd]; 1566 fdp->fd_ofiles[dfd] = NULL; 1567 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 1568 fdp->fd_ofileflags[dfd] = 0; 1569 1570 /* 1571 * we now own the reference to fp that the ofiles[] array 1572 * used to own. Release it. 1573 */ 1574 if (fp) 1575 fdrop(fp, curthread); 1576 /* 1577 * Complete the clean up of the filedesc structure by 1578 * recomputing the various hints. 1579 */ 1580 if (indx > fdp->fd_lastfile) { 1581 fdp->fd_lastfile = indx; 1582 } else { 1583 while (fdp->fd_lastfile > 0 && 1584 fdp->fd_ofiles[fdp->fd_lastfile] == NULL) { 1585 fdp->fd_lastfile--; 1586 } 1587 if (dfd < fdp->fd_freefile) 1588 fdp->fd_freefile = dfd; 1589 } 1590 return (0); 1591 1592 default: 1593 return (error); 1594 } 1595 /* NOTREACHED */ 1596 } 1597 1598 1599 struct filedesc_to_leader * 1600 filedesc_to_leader_alloc(struct filedesc_to_leader *old, 1601 struct proc *leader) 1602 { 1603 struct filedesc_to_leader *fdtol; 1604 1605 MALLOC(fdtol, struct filedesc_to_leader *, 1606 sizeof(struct filedesc_to_leader), 1607 M_FILEDESC_TO_LEADER, 1608 M_WAITOK); 1609 fdtol->fdl_refcount = 1; 1610 fdtol->fdl_holdcount = 0; 1611 fdtol->fdl_wakeup = 0; 1612 fdtol->fdl_leader = leader; 1613 if (old != NULL) { 1614 fdtol->fdl_next = old->fdl_next; 1615 fdtol->fdl_prev = old; 1616 old->fdl_next = fdtol; 1617 fdtol->fdl_next->fdl_prev = fdtol; 1618 } else { 1619 fdtol->fdl_next = fdtol; 1620 fdtol->fdl_prev = fdtol; 1621 } 1622 return fdtol; 1623 } 1624 1625 /* 1626 * Get file structures. 1627 */ 1628 static int 1629 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 1630 { 1631 int error; 1632 struct file *fp; 1633 1634 if (!req->oldptr) { 1635 /* 1636 * overestimate by 10 files 1637 */ 1638 return (SYSCTL_OUT(req, 0, sizeof(filehead) + 1639 (nfiles + 10) * sizeof(struct file))); 1640 } 1641 1642 error = SYSCTL_OUT(req, (caddr_t)&filehead, sizeof(filehead)); 1643 if (error) 1644 return (error); 1645 1646 /* 1647 * followed by an array of file structures 1648 */ 1649 LIST_FOREACH(fp, &filehead, f_list) { 1650 error = SYSCTL_OUT(req, (caddr_t)fp, sizeof (struct file)); 1651 if (error) 1652 return (error); 1653 } 1654 return (0); 1655 } 1656 1657 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD, 1658 0, 0, sysctl_kern_file, "S,file", "Entire file table"); 1659 1660 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 1661 &maxfilesperproc, 0, "Maximum files allowed open per process"); 1662 1663 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 1664 &maxfiles, 0, "Maximum number of files"); 1665 1666 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 1667 &nfiles, 0, "System-wide number of open files"); 1668 1669 static void 1670 fildesc_drvinit(void *unused) 1671 { 1672 int fd; 1673 1674 for (fd = 0; fd < NUMFDESC; fd++) 1675 make_dev(&fildesc_cdevsw, fd, 1676 UID_BIN, GID_BIN, 0666, "fd/%d", fd); 1677 make_dev(&fildesc_cdevsw, 0, UID_ROOT, GID_WHEEL, 0666, "stdin"); 1678 make_dev(&fildesc_cdevsw, 1, UID_ROOT, GID_WHEEL, 0666, "stdout"); 1679 make_dev(&fildesc_cdevsw, 2, UID_ROOT, GID_WHEEL, 0666, "stderr"); 1680 } 1681 1682 struct fileops badfileops = { 1683 NULL, /* port */ 1684 0, /* autoq */ 1685 badfo_readwrite, 1686 badfo_readwrite, 1687 badfo_ioctl, 1688 badfo_poll, 1689 badfo_kqfilter, 1690 badfo_stat, 1691 badfo_close 1692 }; 1693 1694 static int 1695 badfo_readwrite( 1696 struct file *fp, 1697 struct uio *uio, 1698 struct ucred *cred, 1699 int flags, 1700 struct thread *td 1701 ) { 1702 return (EBADF); 1703 } 1704 1705 static int 1706 badfo_ioctl(struct file *fp, u_long com, caddr_t data, struct thread *td) 1707 { 1708 return (EBADF); 1709 } 1710 1711 static int 1712 badfo_poll(struct file *fp, int events, struct ucred *cred, struct thread *td) 1713 { 1714 return (0); 1715 } 1716 1717 static int 1718 badfo_kqfilter(struct file *fp, struct knote *kn) 1719 { 1720 return (0); 1721 } 1722 1723 static int 1724 badfo_stat(struct file *fp, struct stat *sb, struct thread *td) 1725 { 1726 return (EBADF); 1727 } 1728 1729 static int 1730 badfo_close(struct file *fp, struct thread *td) 1731 { 1732 return (EBADF); 1733 } 1734 1735 SYSINIT(fildescdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR, 1736 fildesc_drvinit,NULL) 1737