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/syscallsubr.h> 47 #include <sys/sysproto.h> 48 #include <sys/conf.h> 49 #include <sys/filedesc.h> 50 #include <sys/lock.h> 51 #include <sys/kernel.h> 52 #include <sys/limits.h> 53 #include <sys/malloc.h> 54 #include <sys/mutex.h> 55 #include <sys/sysctl.h> 56 #include <sys/vnode.h> 57 #include <sys/mount.h> 58 #include <sys/proc.h> 59 #include <sys/namei.h> 60 #include <sys/file.h> 61 #include <sys/stat.h> 62 #include <sys/filio.h> 63 #include <sys/fcntl.h> 64 #include <sys/unistd.h> 65 #include <sys/resourcevar.h> 66 #include <sys/event.h> 67 #include <sys/sx.h> 68 #include <sys/socketvar.h> 69 #include <sys/signalvar.h> 70 71 #include <vm/vm.h> 72 #include <vm/vm_extern.h> 73 #include <vm/uma.h> 74 75 static MALLOC_DEFINE(M_FILEDESC, "file desc", "Open file descriptor table"); 76 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "file desc to leader", 77 "file desc to leader structures"); 78 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 79 80 static uma_zone_t file_zone; 81 82 static d_open_t fdopen; 83 #define NUMFDESC 64 84 85 #define CDEV_MAJOR 22 86 static struct cdevsw fildesc_cdevsw = { 87 .d_open = fdopen, 88 .d_name = "FD", 89 .d_maj = CDEV_MAJOR, 90 }; 91 92 /* How to treat 'new' parameter when allocating a fd for do_dup(). */ 93 enum dup_type { DUP_VARIABLE, DUP_FIXED }; 94 95 static int do_dup(struct thread *td, enum dup_type type, int old, int new, 96 register_t *retval); 97 98 /* 99 * Descriptor management. 100 */ 101 struct filelist filehead; /* head of list of open files */ 102 int nfiles; /* actual number of open files */ 103 extern int cmask; 104 struct sx filelist_lock; /* sx to protect filelist */ 105 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 106 107 /* 108 * System calls on descriptors. 109 */ 110 #ifndef _SYS_SYSPROTO_H_ 111 struct getdtablesize_args { 112 int dummy; 113 }; 114 #endif 115 /* 116 * MPSAFE 117 */ 118 /* ARGSUSED */ 119 int 120 getdtablesize(td, uap) 121 struct thread *td; 122 struct getdtablesize_args *uap; 123 { 124 struct proc *p = td->td_proc; 125 126 mtx_lock(&Giant); 127 td->td_retval[0] = 128 min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc); 129 mtx_unlock(&Giant); 130 return (0); 131 } 132 133 /* 134 * Duplicate a file descriptor to a particular value. 135 * 136 * note: keep in mind that a potential race condition exists when closing 137 * descriptors from a shared descriptor table (via rfork). 138 */ 139 #ifndef _SYS_SYSPROTO_H_ 140 struct dup2_args { 141 u_int from; 142 u_int to; 143 }; 144 #endif 145 /* 146 * MPSAFE 147 */ 148 /* ARGSUSED */ 149 int 150 dup2(td, uap) 151 struct thread *td; 152 struct dup2_args *uap; 153 { 154 155 return (do_dup(td, DUP_FIXED, (int)uap->from, (int)uap->to, 156 td->td_retval)); 157 } 158 159 /* 160 * Duplicate a file descriptor. 161 */ 162 #ifndef _SYS_SYSPROTO_H_ 163 struct dup_args { 164 u_int fd; 165 }; 166 #endif 167 /* 168 * MPSAFE 169 */ 170 /* ARGSUSED */ 171 int 172 dup(td, uap) 173 struct thread *td; 174 struct dup_args *uap; 175 { 176 177 return (do_dup(td, DUP_VARIABLE, (int)uap->fd, 0, td->td_retval)); 178 } 179 180 /* 181 * The file control system call. 182 */ 183 #ifndef _SYS_SYSPROTO_H_ 184 struct fcntl_args { 185 int fd; 186 int cmd; 187 long arg; 188 }; 189 #endif 190 /* 191 * MPSAFE 192 */ 193 /* ARGSUSED */ 194 int 195 fcntl(td, uap) 196 struct thread *td; 197 struct fcntl_args *uap; 198 { 199 struct flock fl; 200 intptr_t arg; 201 int error; 202 203 error = 0; 204 switch (uap->cmd) { 205 case F_GETLK: 206 case F_SETLK: 207 case F_SETLKW: 208 error = copyin((void *)(intptr_t)uap->arg, &fl, sizeof(fl)); 209 arg = (intptr_t)&fl; 210 break; 211 default: 212 arg = uap->arg; 213 break; 214 } 215 if (error) 216 return (error); 217 error = kern_fcntl(td, uap->fd, uap->cmd, arg); 218 if (error) 219 return (error); 220 if (uap->cmd == F_GETLK) 221 error = copyout(&fl, (void *)(intptr_t)uap->arg, sizeof(fl)); 222 return (error); 223 } 224 225 int 226 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 227 { 228 struct filedesc *fdp; 229 struct flock *flp; 230 struct file *fp; 231 struct proc *p; 232 char *pop; 233 struct vnode *vp; 234 u_int newmin; 235 int error, flg, tmp; 236 237 error = 0; 238 flg = F_POSIX; 239 p = td->td_proc; 240 fdp = p->p_fd; 241 mtx_lock(&Giant); 242 FILEDESC_LOCK(fdp); 243 if ((unsigned)fd >= fdp->fd_nfiles || 244 (fp = fdp->fd_ofiles[fd]) == NULL) { 245 FILEDESC_UNLOCK(fdp); 246 error = EBADF; 247 goto done2; 248 } 249 pop = &fdp->fd_ofileflags[fd]; 250 251 switch (cmd) { 252 case F_DUPFD: 253 FILEDESC_UNLOCK(fdp); 254 newmin = arg; 255 if (newmin >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur || 256 newmin >= maxfilesperproc) { 257 error = EINVAL; 258 break; 259 } 260 error = do_dup(td, DUP_VARIABLE, fd, newmin, td->td_retval); 261 break; 262 263 case F_GETFD: 264 td->td_retval[0] = (*pop & UF_EXCLOSE) ? FD_CLOEXEC : 0; 265 FILEDESC_UNLOCK(fdp); 266 break; 267 268 case F_SETFD: 269 *pop = (*pop &~ UF_EXCLOSE) | 270 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 271 FILEDESC_UNLOCK(fdp); 272 break; 273 274 case F_GETFL: 275 FILE_LOCK(fp); 276 FILEDESC_UNLOCK(fdp); 277 td->td_retval[0] = OFLAGS(fp->f_flag); 278 FILE_UNLOCK(fp); 279 break; 280 281 case F_SETFL: 282 FILE_LOCK(fp); 283 FILEDESC_UNLOCK(fdp); 284 fhold_locked(fp); 285 fp->f_flag &= ~FCNTLFLAGS; 286 fp->f_flag |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 287 FILE_UNLOCK(fp); 288 tmp = fp->f_flag & FNONBLOCK; 289 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 290 if (error) { 291 fdrop(fp, td); 292 break; 293 } 294 tmp = fp->f_flag & FASYNC; 295 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 296 if (error == 0) { 297 fdrop(fp, td); 298 break; 299 } 300 FILE_LOCK(fp); 301 fp->f_flag &= ~FNONBLOCK; 302 FILE_UNLOCK(fp); 303 tmp = 0; 304 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 305 fdrop(fp, td); 306 break; 307 308 case F_GETOWN: 309 fhold(fp); 310 FILEDESC_UNLOCK(fdp); 311 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 312 if (error == 0) 313 td->td_retval[0] = tmp; 314 fdrop(fp, td); 315 break; 316 317 case F_SETOWN: 318 fhold(fp); 319 FILEDESC_UNLOCK(fdp); 320 tmp = arg; 321 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 322 fdrop(fp, td); 323 break; 324 325 case F_SETLKW: 326 flg |= F_WAIT; 327 /* FALLTHROUGH F_SETLK */ 328 329 case F_SETLK: 330 if (fp->f_type != DTYPE_VNODE) { 331 FILEDESC_UNLOCK(fdp); 332 error = EBADF; 333 break; 334 } 335 336 flp = (struct flock *)arg; 337 if (flp->l_whence == SEEK_CUR) { 338 if (fp->f_offset < 0 || 339 (flp->l_start > 0 && 340 fp->f_offset > OFF_MAX - flp->l_start)) { 341 FILEDESC_UNLOCK(fdp); 342 error = EOVERFLOW; 343 break; 344 } 345 flp->l_start += fp->f_offset; 346 } 347 348 /* 349 * VOP_ADVLOCK() may block. 350 */ 351 fhold(fp); 352 FILEDESC_UNLOCK(fdp); 353 vp = fp->f_data; 354 355 switch (flp->l_type) { 356 case F_RDLCK: 357 if ((fp->f_flag & FREAD) == 0) { 358 error = EBADF; 359 break; 360 } 361 PROC_LOCK(p->p_leader); 362 p->p_leader->p_flag |= P_ADVLOCK; 363 PROC_UNLOCK(p->p_leader); 364 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 365 flp, flg); 366 break; 367 case F_WRLCK: 368 if ((fp->f_flag & FWRITE) == 0) { 369 error = EBADF; 370 break; 371 } 372 PROC_LOCK(p->p_leader); 373 p->p_leader->p_flag |= P_ADVLOCK; 374 PROC_UNLOCK(p->p_leader); 375 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 376 flp, flg); 377 break; 378 case F_UNLCK: 379 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 380 flp, F_POSIX); 381 break; 382 default: 383 error = EINVAL; 384 break; 385 } 386 /* Check for race with close */ 387 FILEDESC_LOCK(fdp); 388 if ((unsigned) fd >= fdp->fd_nfiles || 389 fp != fdp->fd_ofiles[fd]) { 390 FILEDESC_UNLOCK(fdp); 391 flp->l_whence = SEEK_SET; 392 flp->l_start = 0; 393 flp->l_len = 0; 394 flp->l_type = F_UNLCK; 395 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 396 F_UNLCK, flp, F_POSIX); 397 } else 398 FILEDESC_UNLOCK(fdp); 399 fdrop(fp, td); 400 break; 401 402 case F_GETLK: 403 if (fp->f_type != DTYPE_VNODE) { 404 FILEDESC_UNLOCK(fdp); 405 error = EBADF; 406 break; 407 } 408 flp = (struct flock *)arg; 409 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 410 flp->l_type != F_UNLCK) { 411 FILEDESC_UNLOCK(fdp); 412 error = EINVAL; 413 break; 414 } 415 if (flp->l_whence == SEEK_CUR) { 416 if ((flp->l_start > 0 && 417 fp->f_offset > OFF_MAX - flp->l_start) || 418 (flp->l_start < 0 && 419 fp->f_offset < OFF_MIN - flp->l_start)) { 420 FILEDESC_UNLOCK(fdp); 421 error = EOVERFLOW; 422 break; 423 } 424 flp->l_start += fp->f_offset; 425 } 426 /* 427 * VOP_ADVLOCK() may block. 428 */ 429 fhold(fp); 430 FILEDESC_UNLOCK(fdp); 431 vp = fp->f_data; 432 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 433 F_POSIX); 434 fdrop(fp, td); 435 break; 436 default: 437 FILEDESC_UNLOCK(fdp); 438 error = EINVAL; 439 break; 440 } 441 done2: 442 mtx_unlock(&Giant); 443 return (error); 444 } 445 446 /* 447 * Common code for dup, dup2, and fcntl(F_DUPFD). 448 */ 449 static int 450 do_dup(td, type, old, new, retval) 451 enum dup_type type; 452 int old, new; 453 register_t *retval; 454 struct thread *td; 455 { 456 struct filedesc *fdp; 457 struct proc *p; 458 struct file *fp; 459 struct file *delfp; 460 int error, newfd; 461 int holdleaders; 462 463 p = td->td_proc; 464 fdp = p->p_fd; 465 466 /* 467 * Verify we have a valid descriptor to dup from and possibly to 468 * dup to. 469 */ 470 if (old < 0 || new < 0 || new >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur || 471 new >= maxfilesperproc) 472 return (EBADF); 473 FILEDESC_LOCK(fdp); 474 if (old >= fdp->fd_nfiles || fdp->fd_ofiles[old] == NULL) { 475 FILEDESC_UNLOCK(fdp); 476 return (EBADF); 477 } 478 if (type == DUP_FIXED && old == new) { 479 *retval = new; 480 FILEDESC_UNLOCK(fdp); 481 return (0); 482 } 483 fp = fdp->fd_ofiles[old]; 484 fhold(fp); 485 486 /* 487 * Expand the table for the new descriptor if needed. This may 488 * block and drop and reacquire the filedesc lock. 489 */ 490 if (type == DUP_VARIABLE || new >= fdp->fd_nfiles) { 491 error = fdalloc(td, new, &newfd); 492 if (error) { 493 FILEDESC_UNLOCK(fdp); 494 fdrop(fp, td); 495 return (error); 496 } 497 } 498 if (type == DUP_VARIABLE) 499 new = newfd; 500 501 /* 502 * If the old file changed out from under us then treat it as a 503 * bad file descriptor. Userland should do its own locking to 504 * avoid this case. 505 */ 506 if (fdp->fd_ofiles[old] != fp) { 507 if (fdp->fd_ofiles[new] == NULL) { 508 if (new < fdp->fd_freefile) 509 fdp->fd_freefile = new; 510 while (fdp->fd_lastfile > 0 && 511 fdp->fd_ofiles[fdp->fd_lastfile] == NULL) 512 fdp->fd_lastfile--; 513 } 514 FILEDESC_UNLOCK(fdp); 515 fdrop(fp, td); 516 return (EBADF); 517 } 518 KASSERT(old != new, ("new fd is same as old")); 519 520 /* 521 * Save info on the descriptor being overwritten. We have 522 * to do the unmap now, but we cannot close it without 523 * introducing an ownership race for the slot. 524 */ 525 delfp = fdp->fd_ofiles[new]; 526 if (delfp != NULL && p->p_fdtol != NULL) { 527 /* 528 * Ask fdfree() to sleep to ensure that all relevant 529 * process leaders can be traversed in closef(). 530 */ 531 fdp->fd_holdleaderscount++; 532 holdleaders = 1; 533 } else 534 holdleaders = 0; 535 KASSERT(delfp == NULL || type == DUP_FIXED, 536 ("dup() picked an open file")); 537 #if 0 538 if (delfp && (fdp->fd_ofileflags[new] & UF_MAPPED)) 539 (void) munmapfd(td, new); 540 #endif 541 542 /* 543 * Duplicate the source descriptor, update lastfile 544 */ 545 fdp->fd_ofiles[new] = fp; 546 fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] &~ UF_EXCLOSE; 547 if (new > fdp->fd_lastfile) 548 fdp->fd_lastfile = new; 549 FILEDESC_UNLOCK(fdp); 550 *retval = new; 551 552 /* 553 * If we dup'd over a valid file, we now own the reference to it 554 * and must dispose of it using closef() semantics (as if a 555 * close() were performed on it). 556 */ 557 if (delfp) { 558 mtx_lock(&Giant); 559 (void) closef(delfp, td); 560 mtx_unlock(&Giant); 561 if (holdleaders) { 562 FILEDESC_LOCK(fdp); 563 fdp->fd_holdleaderscount--; 564 if (fdp->fd_holdleaderscount == 0 && 565 fdp->fd_holdleaderswakeup != 0) { 566 fdp->fd_holdleaderswakeup = 0; 567 wakeup(&fdp->fd_holdleaderscount); 568 } 569 FILEDESC_UNLOCK(fdp); 570 } 571 } 572 return (0); 573 } 574 575 /* 576 * If sigio is on the list associated with a process or process group, 577 * disable signalling from the device, remove sigio from the list and 578 * free sigio. 579 */ 580 void 581 funsetown(sigiop) 582 struct sigio **sigiop; 583 { 584 struct sigio *sigio; 585 586 SIGIO_LOCK(); 587 sigio = *sigiop; 588 if (sigio == NULL) { 589 SIGIO_UNLOCK(); 590 return; 591 } 592 *(sigio->sio_myref) = NULL; 593 if ((sigio)->sio_pgid < 0) { 594 struct pgrp *pg = (sigio)->sio_pgrp; 595 PGRP_LOCK(pg); 596 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 597 sigio, sio_pgsigio); 598 PGRP_UNLOCK(pg); 599 } else { 600 struct proc *p = (sigio)->sio_proc; 601 PROC_LOCK(p); 602 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 603 sigio, sio_pgsigio); 604 PROC_UNLOCK(p); 605 } 606 SIGIO_UNLOCK(); 607 crfree(sigio->sio_ucred); 608 FREE(sigio, M_SIGIO); 609 } 610 611 /* 612 * Free a list of sigio structures. 613 * We only need to lock the SIGIO_LOCK because we have made ourselves 614 * inaccessable to callers of fsetown and therefore do not need to lock 615 * the proc or pgrp struct for the list manipulation. 616 */ 617 void 618 funsetownlst(sigiolst) 619 struct sigiolst *sigiolst; 620 { 621 struct proc *p; 622 struct pgrp *pg; 623 struct sigio *sigio; 624 625 sigio = SLIST_FIRST(sigiolst); 626 if (sigio == NULL) 627 return; 628 p = NULL; 629 pg = NULL; 630 631 /* 632 * Every entry of the list should belong 633 * to a single proc or pgrp. 634 */ 635 if (sigio->sio_pgid < 0) { 636 pg = sigio->sio_pgrp; 637 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 638 } else /* if (sigio->sio_pgid > 0) */ { 639 p = sigio->sio_proc; 640 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 641 } 642 643 SIGIO_LOCK(); 644 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 645 *(sigio->sio_myref) = NULL; 646 if (pg != NULL) { 647 KASSERT(sigio->sio_pgid < 0, 648 ("Proc sigio in pgrp sigio list")); 649 KASSERT(sigio->sio_pgrp == pg, 650 ("Bogus pgrp in sigio list")); 651 PGRP_LOCK(pg); 652 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 653 sio_pgsigio); 654 PGRP_UNLOCK(pg); 655 } else /* if (p != NULL) */ { 656 KASSERT(sigio->sio_pgid > 0, 657 ("Pgrp sigio in proc sigio list")); 658 KASSERT(sigio->sio_proc == p, 659 ("Bogus proc in sigio list")); 660 PROC_LOCK(p); 661 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 662 sio_pgsigio); 663 PROC_UNLOCK(p); 664 } 665 SIGIO_UNLOCK(); 666 crfree(sigio->sio_ucred); 667 FREE(sigio, M_SIGIO); 668 SIGIO_LOCK(); 669 } 670 SIGIO_UNLOCK(); 671 } 672 673 /* 674 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 675 * 676 * After permission checking, add a sigio structure to the sigio list for 677 * the process or process group. 678 */ 679 int 680 fsetown(pgid, sigiop) 681 pid_t pgid; 682 struct sigio **sigiop; 683 { 684 struct proc *proc; 685 struct pgrp *pgrp; 686 struct sigio *sigio; 687 int ret; 688 689 if (pgid == 0) { 690 funsetown(sigiop); 691 return (0); 692 } 693 694 ret = 0; 695 696 /* Allocate and fill in the new sigio out of locks. */ 697 MALLOC(sigio, struct sigio *, sizeof(struct sigio), M_SIGIO, M_WAITOK); 698 sigio->sio_pgid = pgid; 699 sigio->sio_ucred = crhold(curthread->td_ucred); 700 sigio->sio_myref = sigiop; 701 702 sx_slock(&proctree_lock); 703 if (pgid > 0) { 704 proc = pfind(pgid); 705 if (proc == NULL) { 706 ret = ESRCH; 707 goto fail; 708 } 709 710 /* 711 * Policy - Don't allow a process to FSETOWN a process 712 * in another session. 713 * 714 * Remove this test to allow maximum flexibility or 715 * restrict FSETOWN to the current process or process 716 * group for maximum safety. 717 */ 718 PROC_UNLOCK(proc); 719 if (proc->p_session != curthread->td_proc->p_session) { 720 ret = EPERM; 721 goto fail; 722 } 723 724 pgrp = NULL; 725 } else /* if (pgid < 0) */ { 726 pgrp = pgfind(-pgid); 727 if (pgrp == NULL) { 728 ret = ESRCH; 729 goto fail; 730 } 731 PGRP_UNLOCK(pgrp); 732 733 /* 734 * Policy - Don't allow a process to FSETOWN a process 735 * in another session. 736 * 737 * Remove this test to allow maximum flexibility or 738 * restrict FSETOWN to the current process or process 739 * group for maximum safety. 740 */ 741 if (pgrp->pg_session != curthread->td_proc->p_session) { 742 ret = EPERM; 743 goto fail; 744 } 745 746 proc = NULL; 747 } 748 funsetown(sigiop); 749 if (pgid > 0) { 750 PROC_LOCK(proc); 751 /* 752 * Since funsetownlst() is called without the proctree 753 * locked, we need to check for P_WEXIT. 754 * XXX: is ESRCH correct? 755 */ 756 if ((proc->p_flag & P_WEXIT) != 0) { 757 PROC_UNLOCK(proc); 758 ret = ESRCH; 759 goto fail; 760 } 761 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 762 sigio->sio_proc = proc; 763 PROC_UNLOCK(proc); 764 } else { 765 PGRP_LOCK(pgrp); 766 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 767 sigio->sio_pgrp = pgrp; 768 PGRP_UNLOCK(pgrp); 769 } 770 sx_sunlock(&proctree_lock); 771 SIGIO_LOCK(); 772 *sigiop = sigio; 773 SIGIO_UNLOCK(); 774 return (0); 775 776 fail: 777 sx_sunlock(&proctree_lock); 778 crfree(sigio->sio_ucred); 779 FREE(sigio, M_SIGIO); 780 return (ret); 781 } 782 783 /* 784 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 785 */ 786 pid_t 787 fgetown(sigiop) 788 struct sigio **sigiop; 789 { 790 pid_t pgid; 791 792 SIGIO_LOCK(); 793 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 794 SIGIO_UNLOCK(); 795 return (pgid); 796 } 797 798 /* 799 * Close a file descriptor. 800 */ 801 #ifndef _SYS_SYSPROTO_H_ 802 struct close_args { 803 int fd; 804 }; 805 #endif 806 /* 807 * MPSAFE 808 */ 809 /* ARGSUSED */ 810 int 811 close(td, uap) 812 struct thread *td; 813 struct close_args *uap; 814 { 815 struct filedesc *fdp; 816 struct file *fp; 817 int fd, error; 818 int holdleaders; 819 820 fd = uap->fd; 821 error = 0; 822 holdleaders = 0; 823 fdp = td->td_proc->p_fd; 824 mtx_lock(&Giant); 825 FILEDESC_LOCK(fdp); 826 if ((unsigned)fd >= fdp->fd_nfiles || 827 (fp = fdp->fd_ofiles[fd]) == NULL) { 828 FILEDESC_UNLOCK(fdp); 829 error = EBADF; 830 goto done2; 831 } 832 #if 0 833 if (fdp->fd_ofileflags[fd] & UF_MAPPED) 834 (void) munmapfd(td, fd); 835 #endif 836 fdp->fd_ofiles[fd] = NULL; 837 fdp->fd_ofileflags[fd] = 0; 838 if (td->td_proc->p_fdtol != NULL) { 839 /* 840 * Ask fdfree() to sleep to ensure that all relevant 841 * process leaders can be traversed in closef(). 842 */ 843 fdp->fd_holdleaderscount++; 844 holdleaders = 1; 845 } 846 847 /* 848 * we now hold the fp reference that used to be owned by the descriptor 849 * array. 850 */ 851 while (fdp->fd_lastfile > 0 && fdp->fd_ofiles[fdp->fd_lastfile] == NULL) 852 fdp->fd_lastfile--; 853 if (fd < fdp->fd_freefile) 854 fdp->fd_freefile = fd; 855 if (fd < fdp->fd_knlistsize) { 856 FILEDESC_UNLOCK(fdp); 857 knote_fdclose(td, fd); 858 } else 859 FILEDESC_UNLOCK(fdp); 860 861 error = closef(fp, td); 862 done2: 863 mtx_unlock(&Giant); 864 if (holdleaders) { 865 FILEDESC_LOCK(fdp); 866 fdp->fd_holdleaderscount--; 867 if (fdp->fd_holdleaderscount == 0 && 868 fdp->fd_holdleaderswakeup != 0) { 869 fdp->fd_holdleaderswakeup = 0; 870 wakeup(&fdp->fd_holdleaderscount); 871 } 872 FILEDESC_UNLOCK(fdp); 873 } 874 return (error); 875 } 876 877 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 878 /* 879 * Return status information about a file descriptor. 880 */ 881 #ifndef _SYS_SYSPROTO_H_ 882 struct ofstat_args { 883 int fd; 884 struct ostat *sb; 885 }; 886 #endif 887 /* 888 * MPSAFE 889 */ 890 /* ARGSUSED */ 891 int 892 ofstat(td, uap) 893 struct thread *td; 894 struct ofstat_args *uap; 895 { 896 struct file *fp; 897 struct stat ub; 898 struct ostat oub; 899 int error; 900 901 mtx_lock(&Giant); 902 if ((error = fget(td, uap->fd, &fp)) != 0) 903 goto done2; 904 error = fo_stat(fp, &ub, td->td_ucred, td); 905 if (error == 0) { 906 cvtstat(&ub, &oub); 907 error = copyout(&oub, uap->sb, sizeof(oub)); 908 } 909 fdrop(fp, td); 910 done2: 911 mtx_unlock(&Giant); 912 return (error); 913 } 914 #endif /* COMPAT_43 || COMPAT_SUNOS */ 915 916 /* 917 * Return status information about a file descriptor. 918 */ 919 #ifndef _SYS_SYSPROTO_H_ 920 struct fstat_args { 921 int fd; 922 struct stat *sb; 923 }; 924 #endif 925 /* 926 * MPSAFE 927 */ 928 /* ARGSUSED */ 929 int 930 fstat(td, uap) 931 struct thread *td; 932 struct fstat_args *uap; 933 { 934 struct file *fp; 935 struct stat ub; 936 int error; 937 938 mtx_lock(&Giant); 939 if ((error = fget(td, uap->fd, &fp)) != 0) 940 goto done2; 941 error = fo_stat(fp, &ub, td->td_ucred, td); 942 if (error == 0) 943 error = copyout(&ub, uap->sb, sizeof(ub)); 944 fdrop(fp, td); 945 done2: 946 mtx_unlock(&Giant); 947 return (error); 948 } 949 950 /* 951 * Return status information about a file descriptor. 952 */ 953 #ifndef _SYS_SYSPROTO_H_ 954 struct nfstat_args { 955 int fd; 956 struct nstat *sb; 957 }; 958 #endif 959 /* 960 * MPSAFE 961 */ 962 /* ARGSUSED */ 963 int 964 nfstat(td, uap) 965 struct thread *td; 966 struct nfstat_args *uap; 967 { 968 struct file *fp; 969 struct stat ub; 970 struct nstat nub; 971 int error; 972 973 mtx_lock(&Giant); 974 if ((error = fget(td, uap->fd, &fp)) != 0) 975 goto done2; 976 error = fo_stat(fp, &ub, td->td_ucred, td); 977 if (error == 0) { 978 cvtnstat(&ub, &nub); 979 error = copyout(&nub, uap->sb, sizeof(nub)); 980 } 981 fdrop(fp, td); 982 done2: 983 mtx_unlock(&Giant); 984 return (error); 985 } 986 987 /* 988 * Return pathconf information about a file descriptor. 989 */ 990 #ifndef _SYS_SYSPROTO_H_ 991 struct fpathconf_args { 992 int fd; 993 int name; 994 }; 995 #endif 996 /* 997 * MPSAFE 998 */ 999 /* ARGSUSED */ 1000 int 1001 fpathconf(td, uap) 1002 struct thread *td; 1003 struct fpathconf_args *uap; 1004 { 1005 struct file *fp; 1006 struct vnode *vp; 1007 int error; 1008 1009 if ((error = fget(td, uap->fd, &fp)) != 0) 1010 return (error); 1011 1012 /* If asynchronous I/O is available, it works for all descriptors. */ 1013 if (uap->name == _PC_ASYNC_IO) { 1014 td->td_retval[0] = async_io_version; 1015 goto out; 1016 } 1017 switch (fp->f_type) { 1018 case DTYPE_PIPE: 1019 case DTYPE_SOCKET: 1020 if (uap->name != _PC_PIPE_BUF) { 1021 error = EINVAL; 1022 } else { 1023 td->td_retval[0] = PIPE_BUF; 1024 error = 0; 1025 } 1026 break; 1027 case DTYPE_FIFO: 1028 case DTYPE_VNODE: 1029 vp = fp->f_data; 1030 mtx_lock(&Giant); 1031 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1032 error = VOP_PATHCONF(vp, uap->name, td->td_retval); 1033 VOP_UNLOCK(vp, 0, td); 1034 mtx_unlock(&Giant); 1035 break; 1036 default: 1037 error = EOPNOTSUPP; 1038 break; 1039 } 1040 out: 1041 fdrop(fp, td); 1042 return (error); 1043 } 1044 1045 /* 1046 * Allocate a file descriptor for the process. 1047 */ 1048 static int fdexpand; 1049 SYSCTL_INT(_debug, OID_AUTO, fdexpand, CTLFLAG_RD, &fdexpand, 0, ""); 1050 1051 int 1052 fdalloc(td, want, result) 1053 struct thread *td; 1054 int want; 1055 int *result; 1056 { 1057 struct proc *p = td->td_proc; 1058 struct filedesc *fdp = td->td_proc->p_fd; 1059 int i; 1060 int lim, last, nfiles; 1061 struct file **newofile, **oldofile; 1062 char *newofileflags; 1063 1064 FILEDESC_LOCK_ASSERT(fdp, MA_OWNED); 1065 1066 /* 1067 * Search for a free descriptor starting at the higher 1068 * of want or fd_freefile. If that fails, consider 1069 * expanding the ofile array. 1070 */ 1071 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc); 1072 for (;;) { 1073 last = min(fdp->fd_nfiles, lim); 1074 i = max(want, fdp->fd_freefile); 1075 for (; i < last; i++) { 1076 if (fdp->fd_ofiles[i] == NULL) { 1077 fdp->fd_ofileflags[i] = 0; 1078 if (i > fdp->fd_lastfile) 1079 fdp->fd_lastfile = i; 1080 if (want <= fdp->fd_freefile) 1081 fdp->fd_freefile = i; 1082 *result = i; 1083 return (0); 1084 } 1085 } 1086 1087 /* 1088 * No space in current array. Expand? 1089 */ 1090 if (i >= lim) 1091 return (EMFILE); 1092 if (fdp->fd_nfiles < NDEXTENT) 1093 nfiles = NDEXTENT; 1094 else 1095 nfiles = 2 * fdp->fd_nfiles; 1096 while (nfiles < want) 1097 nfiles <<= 1; 1098 FILEDESC_UNLOCK(fdp); 1099 /* 1100 * XXX malloc() calls uma_large_malloc() for sizes larger 1101 * than KMEM_ZMAX bytes. uma_large_malloc() requires Giant. 1102 */ 1103 mtx_lock(&Giant); 1104 newofile = malloc(nfiles * OFILESIZE, M_FILEDESC, M_WAITOK); 1105 mtx_unlock(&Giant); 1106 1107 /* 1108 * Deal with file-table extend race that might have 1109 * occurred while filedesc was unlocked. 1110 */ 1111 FILEDESC_LOCK(fdp); 1112 if (fdp->fd_nfiles >= nfiles) { 1113 /* XXX uma_large_free() needs Giant. */ 1114 FILEDESC_UNLOCK(fdp); 1115 mtx_lock(&Giant); 1116 free(newofile, M_FILEDESC); 1117 mtx_unlock(&Giant); 1118 FILEDESC_LOCK(fdp); 1119 continue; 1120 } 1121 newofileflags = (char *) &newofile[nfiles]; 1122 /* 1123 * Copy the existing ofile and ofileflags arrays 1124 * and zero the new portion of each array. 1125 */ 1126 i = fdp->fd_nfiles * sizeof(struct file *); 1127 bcopy(fdp->fd_ofiles, newofile, i); 1128 bzero((char *)newofile + i, 1129 nfiles * sizeof(struct file *) - i); 1130 i = fdp->fd_nfiles * sizeof(char); 1131 bcopy(fdp->fd_ofileflags, newofileflags, i); 1132 bzero(newofileflags + i, nfiles * sizeof(char) - i); 1133 if (fdp->fd_nfiles > NDFILE) 1134 oldofile = fdp->fd_ofiles; 1135 else 1136 oldofile = NULL; 1137 fdp->fd_ofiles = newofile; 1138 fdp->fd_ofileflags = newofileflags; 1139 fdp->fd_nfiles = nfiles; 1140 fdexpand++; 1141 if (oldofile != NULL) { 1142 /* XXX uma_large_free() needs Giant. */ 1143 FILEDESC_UNLOCK(fdp); 1144 mtx_lock(&Giant); 1145 free(oldofile, M_FILEDESC); 1146 mtx_unlock(&Giant); 1147 FILEDESC_LOCK(fdp); 1148 } 1149 } 1150 } 1151 1152 /* 1153 * Check to see whether n user file descriptors 1154 * are available to the process p. 1155 */ 1156 int 1157 fdavail(td, n) 1158 struct thread *td; 1159 int n; 1160 { 1161 struct proc *p = td->td_proc; 1162 struct filedesc *fdp = td->td_proc->p_fd; 1163 struct file **fpp; 1164 int i, lim, last; 1165 1166 FILEDESC_LOCK_ASSERT(fdp, MA_OWNED); 1167 1168 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc); 1169 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) 1170 return (1); 1171 last = min(fdp->fd_nfiles, lim); 1172 fpp = &fdp->fd_ofiles[fdp->fd_freefile]; 1173 for (i = last - fdp->fd_freefile; --i >= 0; fpp++) { 1174 if (*fpp == NULL && --n <= 0) 1175 return (1); 1176 } 1177 return (0); 1178 } 1179 1180 /* 1181 * Create a new open file structure and allocate 1182 * a file decriptor for the process that refers to it. 1183 */ 1184 int 1185 falloc(td, resultfp, resultfd) 1186 struct thread *td; 1187 struct file **resultfp; 1188 int *resultfd; 1189 { 1190 struct proc *p = td->td_proc; 1191 struct file *fp, *fq; 1192 int error, i; 1193 1194 fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO); 1195 sx_xlock(&filelist_lock); 1196 if (nfiles >= maxfiles) { 1197 sx_xunlock(&filelist_lock); 1198 uma_zfree(file_zone, fp); 1199 tablefull("file"); 1200 return (ENFILE); 1201 } 1202 nfiles++; 1203 1204 /* 1205 * If the process has file descriptor zero open, add the new file 1206 * descriptor to the list of open files at that point, otherwise 1207 * put it at the front of the list of open files. 1208 */ 1209 fp->f_mtxp = mtx_pool_alloc(); 1210 fp->f_gcflag = 0; 1211 fp->f_count = 1; 1212 fp->f_cred = crhold(td->td_ucred); 1213 fp->f_ops = &badfileops; 1214 fp->f_seqcount = 1; 1215 FILEDESC_LOCK(p->p_fd); 1216 if ((fq = p->p_fd->fd_ofiles[0])) { 1217 LIST_INSERT_AFTER(fq, fp, f_list); 1218 } else { 1219 LIST_INSERT_HEAD(&filehead, fp, f_list); 1220 } 1221 sx_xunlock(&filelist_lock); 1222 if ((error = fdalloc(td, 0, &i))) { 1223 FILEDESC_UNLOCK(p->p_fd); 1224 fdrop(fp, td); 1225 return (error); 1226 } 1227 p->p_fd->fd_ofiles[i] = fp; 1228 FILEDESC_UNLOCK(p->p_fd); 1229 if (resultfp) 1230 *resultfp = fp; 1231 if (resultfd) 1232 *resultfd = i; 1233 return (0); 1234 } 1235 1236 /* 1237 * Free a file descriptor. 1238 */ 1239 void 1240 ffree(fp) 1241 struct file *fp; 1242 { 1243 1244 KASSERT(fp->f_count == 0, ("ffree: fp_fcount not 0!")); 1245 sx_xlock(&filelist_lock); 1246 LIST_REMOVE(fp, f_list); 1247 nfiles--; 1248 sx_xunlock(&filelist_lock); 1249 crfree(fp->f_cred); 1250 uma_zfree(file_zone, fp); 1251 } 1252 1253 /* 1254 * Build a new filedesc structure from another. 1255 * Copy the current, root, and jail root vnode references. 1256 */ 1257 struct filedesc * 1258 fdinit(fdp) 1259 struct filedesc *fdp; 1260 { 1261 struct filedesc0 *newfdp; 1262 1263 MALLOC(newfdp, struct filedesc0 *, sizeof(struct filedesc0), 1264 M_FILEDESC, M_WAITOK | M_ZERO); 1265 mtx_init(&newfdp->fd_fd.fd_mtx, FILEDESC_LOCK_DESC, NULL, MTX_DEF); 1266 newfdp->fd_fd.fd_cdir = fdp->fd_cdir; 1267 if (newfdp->fd_fd.fd_cdir) 1268 VREF(newfdp->fd_fd.fd_cdir); 1269 newfdp->fd_fd.fd_rdir = fdp->fd_rdir; 1270 if (newfdp->fd_fd.fd_rdir) 1271 VREF(newfdp->fd_fd.fd_rdir); 1272 newfdp->fd_fd.fd_jdir = fdp->fd_jdir; 1273 if (newfdp->fd_fd.fd_jdir) 1274 VREF(newfdp->fd_fd.fd_jdir); 1275 1276 /* Create the file descriptor table. */ 1277 newfdp->fd_fd.fd_refcnt = 1; 1278 newfdp->fd_fd.fd_cmask = cmask; 1279 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles; 1280 newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags; 1281 newfdp->fd_fd.fd_nfiles = NDFILE; 1282 newfdp->fd_fd.fd_knlistsize = -1; 1283 return (&newfdp->fd_fd); 1284 } 1285 1286 /* 1287 * Share a filedesc structure. 1288 */ 1289 struct filedesc * 1290 fdshare(fdp) 1291 struct filedesc *fdp; 1292 { 1293 FILEDESC_LOCK(fdp); 1294 fdp->fd_refcnt++; 1295 FILEDESC_UNLOCK(fdp); 1296 return (fdp); 1297 } 1298 1299 /* 1300 * Copy a filedesc structure. 1301 * A NULL pointer in returns a NULL reference, this is to ease callers, 1302 * not catch errors. 1303 */ 1304 struct filedesc * 1305 fdcopy(fdp) 1306 struct filedesc *fdp; 1307 { 1308 struct filedesc *newfdp; 1309 struct file **fpp; 1310 int i, j; 1311 1312 /* Certain daemons might not have file descriptors. */ 1313 if (fdp == NULL) 1314 return (NULL); 1315 1316 FILEDESC_LOCK_ASSERT(fdp, MA_OWNED); 1317 1318 FILEDESC_UNLOCK(fdp); 1319 MALLOC(newfdp, struct filedesc *, sizeof(struct filedesc0), 1320 M_FILEDESC, M_WAITOK); 1321 FILEDESC_LOCK(fdp); 1322 bcopy(fdp, newfdp, sizeof(struct filedesc)); 1323 FILEDESC_UNLOCK(fdp); 1324 bzero(&newfdp->fd_mtx, sizeof(newfdp->fd_mtx)); 1325 mtx_init(&newfdp->fd_mtx, FILEDESC_LOCK_DESC, NULL, MTX_DEF); 1326 if (newfdp->fd_cdir) 1327 VREF(newfdp->fd_cdir); 1328 if (newfdp->fd_rdir) 1329 VREF(newfdp->fd_rdir); 1330 if (newfdp->fd_jdir) 1331 VREF(newfdp->fd_jdir); 1332 newfdp->fd_refcnt = 1; 1333 1334 /* 1335 * If the number of open files fits in the internal arrays 1336 * of the open file structure, use them, otherwise allocate 1337 * additional memory for the number of descriptors currently 1338 * in use. 1339 */ 1340 FILEDESC_LOCK(fdp); 1341 newfdp->fd_lastfile = fdp->fd_lastfile; 1342 newfdp->fd_nfiles = fdp->fd_nfiles; 1343 if (newfdp->fd_lastfile < NDFILE) { 1344 newfdp->fd_ofiles = ((struct filedesc0 *) newfdp)->fd_dfiles; 1345 newfdp->fd_ofileflags = 1346 ((struct filedesc0 *) newfdp)->fd_dfileflags; 1347 i = NDFILE; 1348 } else { 1349 /* 1350 * Compute the smallest multiple of NDEXTENT needed 1351 * for the file descriptors currently in use, 1352 * allowing the table to shrink. 1353 */ 1354 retry: 1355 i = newfdp->fd_nfiles; 1356 while (i > 2 * NDEXTENT && i > newfdp->fd_lastfile * 2) 1357 i /= 2; 1358 FILEDESC_UNLOCK(fdp); 1359 MALLOC(newfdp->fd_ofiles, struct file **, i * OFILESIZE, 1360 M_FILEDESC, M_WAITOK); 1361 FILEDESC_LOCK(fdp); 1362 newfdp->fd_lastfile = fdp->fd_lastfile; 1363 newfdp->fd_nfiles = fdp->fd_nfiles; 1364 j = newfdp->fd_nfiles; 1365 while (j > 2 * NDEXTENT && j > newfdp->fd_lastfile * 2) 1366 j /= 2; 1367 if (i != j) { 1368 /* 1369 * The size of the original table has changed. 1370 * Go over once again. 1371 */ 1372 FILEDESC_UNLOCK(fdp); 1373 FREE(newfdp->fd_ofiles, M_FILEDESC); 1374 FILEDESC_LOCK(fdp); 1375 newfdp->fd_lastfile = fdp->fd_lastfile; 1376 newfdp->fd_nfiles = fdp->fd_nfiles; 1377 goto retry; 1378 } 1379 newfdp->fd_ofileflags = (char *) &newfdp->fd_ofiles[i]; 1380 } 1381 newfdp->fd_nfiles = i; 1382 bcopy(fdp->fd_ofiles, newfdp->fd_ofiles, i * sizeof(struct file **)); 1383 bcopy(fdp->fd_ofileflags, newfdp->fd_ofileflags, i * sizeof(char)); 1384 1385 /* 1386 * kq descriptors cannot be copied. 1387 */ 1388 if (newfdp->fd_knlistsize != -1) { 1389 fpp = &newfdp->fd_ofiles[newfdp->fd_lastfile]; 1390 for (i = newfdp->fd_lastfile; i >= 0; i--, fpp--) { 1391 if (*fpp != NULL && (*fpp)->f_type == DTYPE_KQUEUE) { 1392 *fpp = NULL; 1393 if (i < newfdp->fd_freefile) 1394 newfdp->fd_freefile = i; 1395 } 1396 if (*fpp == NULL && i == newfdp->fd_lastfile && i > 0) 1397 newfdp->fd_lastfile--; 1398 } 1399 newfdp->fd_knlist = NULL; 1400 newfdp->fd_knlistsize = -1; 1401 newfdp->fd_knhash = NULL; 1402 newfdp->fd_knhashmask = 0; 1403 } 1404 1405 fpp = newfdp->fd_ofiles; 1406 for (i = newfdp->fd_lastfile; i-- >= 0; fpp++) { 1407 if (*fpp != NULL) 1408 fhold(*fpp); 1409 } 1410 return (newfdp); 1411 } 1412 1413 /* A mutex to protect the association between a proc and filedesc. */ 1414 struct mtx fdesc_mtx; 1415 MTX_SYSINIT(fdesc, &fdesc_mtx, "fdesc", MTX_DEF); 1416 1417 /* 1418 * Release a filedesc structure. 1419 */ 1420 void 1421 fdfree(td) 1422 struct thread *td; 1423 { 1424 struct filedesc *fdp; 1425 struct file **fpp; 1426 int i; 1427 struct filedesc_to_leader *fdtol; 1428 struct file *fp; 1429 struct vnode *vp; 1430 struct flock lf; 1431 1432 /* Certain daemons might not have file descriptors. */ 1433 fdp = td->td_proc->p_fd; 1434 if (fdp == NULL) 1435 return; 1436 1437 /* Check for special need to clear POSIX style locks */ 1438 fdtol = td->td_proc->p_fdtol; 1439 if (fdtol != NULL) { 1440 FILEDESC_LOCK(fdp); 1441 KASSERT(fdtol->fdl_refcount > 0, 1442 ("filedesc_to_refcount botch: fdl_refcount=%d", 1443 fdtol->fdl_refcount)); 1444 if (fdtol->fdl_refcount == 1 && 1445 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 1446 i = 0; 1447 fpp = fdp->fd_ofiles; 1448 for (i = 0, fpp = fdp->fd_ofiles; 1449 i < fdp->fd_lastfile; 1450 i++, fpp++) { 1451 if (*fpp == NULL || 1452 (*fpp)->f_type != DTYPE_VNODE) 1453 continue; 1454 fp = *fpp; 1455 fhold(fp); 1456 FILEDESC_UNLOCK(fdp); 1457 lf.l_whence = SEEK_SET; 1458 lf.l_start = 0; 1459 lf.l_len = 0; 1460 lf.l_type = F_UNLCK; 1461 vp = fp->f_data; 1462 (void) VOP_ADVLOCK(vp, 1463 (caddr_t)td->td_proc-> 1464 p_leader, 1465 F_UNLCK, 1466 &lf, 1467 F_POSIX); 1468 FILEDESC_LOCK(fdp); 1469 fdrop(fp, td); 1470 fpp = fdp->fd_ofiles + i; 1471 } 1472 } 1473 retry: 1474 if (fdtol->fdl_refcount == 1) { 1475 if (fdp->fd_holdleaderscount > 0 && 1476 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 1477 /* 1478 * close() or do_dup() has cleared a reference 1479 * in a shared file descriptor table. 1480 */ 1481 fdp->fd_holdleaderswakeup = 1; 1482 msleep(&fdp->fd_holdleaderscount, &fdp->fd_mtx, 1483 PLOCK, "fdlhold", 0); 1484 goto retry; 1485 } 1486 if (fdtol->fdl_holdcount > 0) { 1487 /* 1488 * Ensure that fdtol->fdl_leader 1489 * remains valid in closef(). 1490 */ 1491 fdtol->fdl_wakeup = 1; 1492 msleep(fdtol, &fdp->fd_mtx, 1493 PLOCK, "fdlhold", 0); 1494 goto retry; 1495 } 1496 } 1497 fdtol->fdl_refcount--; 1498 if (fdtol->fdl_refcount == 0 && 1499 fdtol->fdl_holdcount == 0) { 1500 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 1501 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 1502 } else 1503 fdtol = NULL; 1504 td->td_proc->p_fdtol = NULL; 1505 FILEDESC_UNLOCK(fdp); 1506 if (fdtol != NULL) 1507 FREE(fdtol, M_FILEDESC_TO_LEADER); 1508 } 1509 FILEDESC_LOCK(fdp); 1510 if (--fdp->fd_refcnt > 0) { 1511 FILEDESC_UNLOCK(fdp); 1512 return; 1513 } 1514 1515 /* 1516 * We are the last reference to the structure, so we can 1517 * safely assume it will not change out from under us. 1518 */ 1519 FILEDESC_UNLOCK(fdp); 1520 fpp = fdp->fd_ofiles; 1521 for (i = fdp->fd_lastfile; i-- >= 0; fpp++) { 1522 if (*fpp) 1523 (void) closef(*fpp, td); 1524 } 1525 1526 /* XXX This should happen earlier. */ 1527 mtx_lock(&fdesc_mtx); 1528 td->td_proc->p_fd = NULL; 1529 mtx_unlock(&fdesc_mtx); 1530 1531 if (fdp->fd_nfiles > NDFILE) 1532 FREE(fdp->fd_ofiles, M_FILEDESC); 1533 if (fdp->fd_cdir) 1534 vrele(fdp->fd_cdir); 1535 if (fdp->fd_rdir) 1536 vrele(fdp->fd_rdir); 1537 if (fdp->fd_jdir) 1538 vrele(fdp->fd_jdir); 1539 if (fdp->fd_knlist) 1540 FREE(fdp->fd_knlist, M_KQUEUE); 1541 if (fdp->fd_knhash) 1542 FREE(fdp->fd_knhash, M_KQUEUE); 1543 mtx_destroy(&fdp->fd_mtx); 1544 FREE(fdp, M_FILEDESC); 1545 } 1546 1547 /* 1548 * For setugid programs, we don't want to people to use that setugidness 1549 * to generate error messages which write to a file which otherwise would 1550 * otherwise be off-limits to the process. We check for filesystems where 1551 * the vnode can change out from under us after execve (like [lin]procfs). 1552 * 1553 * Since setugidsafety calls this only for fd 0, 1 and 2, this check is 1554 * sufficient. We also don't for check setugidness since we know we are. 1555 */ 1556 static int 1557 is_unsafe(struct file *fp) 1558 { 1559 if (fp->f_type == DTYPE_VNODE) { 1560 struct vnode *vp = fp->f_data; 1561 1562 if ((vp->v_vflag & VV_PROCDEP) != 0) 1563 return (1); 1564 } 1565 return (0); 1566 } 1567 1568 /* 1569 * Make this setguid thing safe, if at all possible. 1570 */ 1571 void 1572 setugidsafety(td) 1573 struct thread *td; 1574 { 1575 struct filedesc *fdp; 1576 int i; 1577 1578 /* Certain daemons might not have file descriptors. */ 1579 fdp = td->td_proc->p_fd; 1580 if (fdp == NULL) 1581 return; 1582 1583 /* 1584 * Note: fdp->fd_ofiles may be reallocated out from under us while 1585 * we are blocked in a close. Be careful! 1586 */ 1587 FILEDESC_LOCK(fdp); 1588 for (i = 0; i <= fdp->fd_lastfile; i++) { 1589 if (i > 2) 1590 break; 1591 if (fdp->fd_ofiles[i] && is_unsafe(fdp->fd_ofiles[i])) { 1592 struct file *fp; 1593 1594 #if 0 1595 if ((fdp->fd_ofileflags[i] & UF_MAPPED) != 0) 1596 (void) munmapfd(td, i); 1597 #endif 1598 if (i < fdp->fd_knlistsize) { 1599 FILEDESC_UNLOCK(fdp); 1600 knote_fdclose(td, i); 1601 FILEDESC_LOCK(fdp); 1602 } 1603 /* 1604 * NULL-out descriptor prior to close to avoid 1605 * a race while close blocks. 1606 */ 1607 fp = fdp->fd_ofiles[i]; 1608 fdp->fd_ofiles[i] = NULL; 1609 fdp->fd_ofileflags[i] = 0; 1610 if (i < fdp->fd_freefile) 1611 fdp->fd_freefile = i; 1612 FILEDESC_UNLOCK(fdp); 1613 (void) closef(fp, td); 1614 FILEDESC_LOCK(fdp); 1615 } 1616 } 1617 while (fdp->fd_lastfile > 0 && fdp->fd_ofiles[fdp->fd_lastfile] == NULL) 1618 fdp->fd_lastfile--; 1619 FILEDESC_UNLOCK(fdp); 1620 } 1621 1622 /* 1623 * Close any files on exec? 1624 */ 1625 void 1626 fdcloseexec(td) 1627 struct thread *td; 1628 { 1629 struct filedesc *fdp; 1630 int i; 1631 1632 /* Certain daemons might not have file descriptors. */ 1633 fdp = td->td_proc->p_fd; 1634 if (fdp == NULL) 1635 return; 1636 1637 FILEDESC_LOCK(fdp); 1638 1639 /* 1640 * We cannot cache fd_ofiles or fd_ofileflags since operations 1641 * may block and rip them out from under us. 1642 */ 1643 for (i = 0; i <= fdp->fd_lastfile; i++) { 1644 if (fdp->fd_ofiles[i] != NULL && 1645 (fdp->fd_ofileflags[i] & UF_EXCLOSE)) { 1646 struct file *fp; 1647 1648 #if 0 1649 if (fdp->fd_ofileflags[i] & UF_MAPPED) 1650 (void) munmapfd(td, i); 1651 #endif 1652 if (i < fdp->fd_knlistsize) { 1653 FILEDESC_UNLOCK(fdp); 1654 knote_fdclose(td, i); 1655 FILEDESC_LOCK(fdp); 1656 } 1657 /* 1658 * NULL-out descriptor prior to close to avoid 1659 * a race while close blocks. 1660 */ 1661 fp = fdp->fd_ofiles[i]; 1662 fdp->fd_ofiles[i] = NULL; 1663 fdp->fd_ofileflags[i] = 0; 1664 if (i < fdp->fd_freefile) 1665 fdp->fd_freefile = i; 1666 FILEDESC_UNLOCK(fdp); 1667 (void) closef(fp, td); 1668 FILEDESC_LOCK(fdp); 1669 } 1670 } 1671 while (fdp->fd_lastfile > 0 && fdp->fd_ofiles[fdp->fd_lastfile] == NULL) 1672 fdp->fd_lastfile--; 1673 FILEDESC_UNLOCK(fdp); 1674 } 1675 1676 /* 1677 * It is unsafe for set[ug]id processes to be started with file 1678 * descriptors 0..2 closed, as these descriptors are given implicit 1679 * significance in the Standard C library. fdcheckstd() will create a 1680 * descriptor referencing /dev/null for each of stdin, stdout, and 1681 * stderr that is not already open. 1682 */ 1683 int 1684 fdcheckstd(td) 1685 struct thread *td; 1686 { 1687 struct nameidata nd; 1688 struct filedesc *fdp; 1689 struct file *fp; 1690 register_t retval; 1691 int fd, i, error, flags, devnull; 1692 1693 fdp = td->td_proc->p_fd; 1694 if (fdp == NULL) 1695 return (0); 1696 devnull = -1; 1697 error = 0; 1698 for (i = 0; i < 3; i++) { 1699 if (fdp->fd_ofiles[i] != NULL) 1700 continue; 1701 if (devnull < 0) { 1702 error = falloc(td, &fp, &fd); 1703 if (error != 0) 1704 break; 1705 KASSERT(fd == i, ("oof, we didn't get our fd")); 1706 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/dev/null", 1707 td); 1708 flags = FREAD | FWRITE; 1709 error = vn_open(&nd, &flags, 0); 1710 if (error != 0) { 1711 FILEDESC_LOCK(fdp); 1712 fdp->fd_ofiles[fd] = NULL; 1713 FILEDESC_UNLOCK(fdp); 1714 fdrop(fp, td); 1715 break; 1716 } 1717 NDFREE(&nd, NDF_ONLY_PNBUF); 1718 fp->f_data = nd.ni_vp; 1719 fp->f_flag = flags; 1720 fp->f_ops = &vnops; 1721 fp->f_type = DTYPE_VNODE; 1722 VOP_UNLOCK(nd.ni_vp, 0, td); 1723 devnull = fd; 1724 } else { 1725 error = do_dup(td, DUP_FIXED, devnull, i, &retval); 1726 if (error != 0) 1727 break; 1728 } 1729 } 1730 return (error); 1731 } 1732 1733 /* 1734 * Internal form of close. 1735 * Decrement reference count on file structure. 1736 * Note: td may be NULL when closing a file 1737 * that was being passed in a message. 1738 */ 1739 int 1740 closef(fp, td) 1741 struct file *fp; 1742 struct thread *td; 1743 { 1744 struct vnode *vp; 1745 struct flock lf; 1746 struct filedesc_to_leader *fdtol; 1747 struct filedesc *fdp; 1748 1749 if (fp == NULL) 1750 return (0); 1751 /* 1752 * POSIX record locking dictates that any close releases ALL 1753 * locks owned by this process. This is handled by setting 1754 * a flag in the unlock to free ONLY locks obeying POSIX 1755 * semantics, and not to free BSD-style file locks. 1756 * If the descriptor was in a message, POSIX-style locks 1757 * aren't passed with the descriptor. 1758 */ 1759 if (td != NULL && 1760 fp->f_type == DTYPE_VNODE) { 1761 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 1762 lf.l_whence = SEEK_SET; 1763 lf.l_start = 0; 1764 lf.l_len = 0; 1765 lf.l_type = F_UNLCK; 1766 vp = fp->f_data; 1767 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 1768 F_UNLCK, &lf, F_POSIX); 1769 } 1770 fdtol = td->td_proc->p_fdtol; 1771 if (fdtol != NULL) { 1772 /* 1773 * Handle special case where file descriptor table 1774 * is shared between multiple process leaders. 1775 */ 1776 fdp = td->td_proc->p_fd; 1777 FILEDESC_LOCK(fdp); 1778 for (fdtol = fdtol->fdl_next; 1779 fdtol != td->td_proc->p_fdtol; 1780 fdtol = fdtol->fdl_next) { 1781 if ((fdtol->fdl_leader->p_flag & 1782 P_ADVLOCK) == 0) 1783 continue; 1784 fdtol->fdl_holdcount++; 1785 FILEDESC_UNLOCK(fdp); 1786 lf.l_whence = SEEK_SET; 1787 lf.l_start = 0; 1788 lf.l_len = 0; 1789 lf.l_type = F_UNLCK; 1790 vp = fp->f_data; 1791 (void) VOP_ADVLOCK(vp, 1792 (caddr_t)fdtol->fdl_leader, 1793 F_UNLCK, &lf, F_POSIX); 1794 FILEDESC_LOCK(fdp); 1795 fdtol->fdl_holdcount--; 1796 if (fdtol->fdl_holdcount == 0 && 1797 fdtol->fdl_wakeup != 0) { 1798 fdtol->fdl_wakeup = 0; 1799 wakeup(fdtol); 1800 } 1801 } 1802 FILEDESC_UNLOCK(fdp); 1803 } 1804 } 1805 return (fdrop(fp, td)); 1806 } 1807 1808 /* 1809 * Drop reference on struct file passed in, may call closef if the 1810 * reference hits zero. 1811 */ 1812 int 1813 fdrop(fp, td) 1814 struct file *fp; 1815 struct thread *td; 1816 { 1817 1818 FILE_LOCK(fp); 1819 return (fdrop_locked(fp, td)); 1820 } 1821 1822 /* 1823 * Extract the file pointer associated with the specified descriptor for 1824 * the current user process. 1825 * 1826 * If the descriptor doesn't exist, EBADF is returned. 1827 * 1828 * If the descriptor exists but doesn't match 'flags' then 1829 * return EBADF for read attempts and EINVAL for write attempts. 1830 * 1831 * If 'hold' is set (non-zero) the file's refcount will be bumped on return. 1832 * It should be droped with fdrop(). 1833 * If it is not set, then the refcount will not be bumped however the 1834 * thread's filedesc struct will be returned locked (for fgetsock). 1835 * 1836 * If an error occured the non-zero error is returned and *fpp is set to NULL. 1837 * Otherwise *fpp is set and zero is returned. 1838 */ 1839 static __inline int 1840 _fget(struct thread *td, int fd, struct file **fpp, int flags, int hold) 1841 { 1842 struct filedesc *fdp; 1843 struct file *fp; 1844 1845 *fpp = NULL; 1846 if (td == NULL || (fdp = td->td_proc->p_fd) == NULL) 1847 return (EBADF); 1848 FILEDESC_LOCK(fdp); 1849 if ((fp = fget_locked(fdp, fd)) == NULL || fp->f_ops == &badfileops) { 1850 FILEDESC_UNLOCK(fdp); 1851 return (EBADF); 1852 } 1853 1854 /* 1855 * Note: FREAD failures returns EBADF to maintain backwards 1856 * compatibility with what routines returned before. 1857 * 1858 * Only one flag, or 0, may be specified. 1859 */ 1860 if (flags == FREAD && (fp->f_flag & FREAD) == 0) { 1861 FILEDESC_UNLOCK(fdp); 1862 return (EBADF); 1863 } 1864 if (flags == FWRITE && (fp->f_flag & FWRITE) == 0) { 1865 FILEDESC_UNLOCK(fdp); 1866 return (EINVAL); 1867 } 1868 if (hold) { 1869 fhold(fp); 1870 FILEDESC_UNLOCK(fdp); 1871 } 1872 *fpp = fp; 1873 return (0); 1874 } 1875 1876 int 1877 fget(struct thread *td, int fd, struct file **fpp) 1878 { 1879 1880 return(_fget(td, fd, fpp, 0, 1)); 1881 } 1882 1883 int 1884 fget_read(struct thread *td, int fd, struct file **fpp) 1885 { 1886 1887 return(_fget(td, fd, fpp, FREAD, 1)); 1888 } 1889 1890 int 1891 fget_write(struct thread *td, int fd, struct file **fpp) 1892 { 1893 1894 return(_fget(td, fd, fpp, FWRITE, 1)); 1895 } 1896 1897 /* 1898 * Like fget() but loads the underlying vnode, or returns an error if 1899 * the descriptor does not represent a vnode. Note that pipes use vnodes 1900 * but never have VM objects (so VOP_GETVOBJECT() calls will return an 1901 * error). The returned vnode will be vref()d. 1902 */ 1903 static __inline int 1904 _fgetvp(struct thread *td, int fd, struct vnode **vpp, int flags) 1905 { 1906 struct file *fp; 1907 int error; 1908 1909 *vpp = NULL; 1910 if ((error = _fget(td, fd, &fp, 0, 0)) != 0) 1911 return (error); 1912 if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) { 1913 error = EINVAL; 1914 } else { 1915 *vpp = fp->f_data; 1916 vref(*vpp); 1917 } 1918 FILEDESC_UNLOCK(td->td_proc->p_fd); 1919 return (error); 1920 } 1921 1922 int 1923 fgetvp(struct thread *td, int fd, struct vnode **vpp) 1924 { 1925 1926 return (_fgetvp(td, fd, vpp, 0)); 1927 } 1928 1929 int 1930 fgetvp_read(struct thread *td, int fd, struct vnode **vpp) 1931 { 1932 1933 return (_fgetvp(td, fd, vpp, FREAD)); 1934 } 1935 1936 int 1937 fgetvp_write(struct thread *td, int fd, struct vnode **vpp) 1938 { 1939 1940 return (_fgetvp(td, fd, vpp, FWRITE)); 1941 } 1942 1943 /* 1944 * Like fget() but loads the underlying socket, or returns an error if 1945 * the descriptor does not represent a socket. 1946 * 1947 * We bump the ref count on the returned socket. XXX Also obtain the SX 1948 * lock in the future. 1949 */ 1950 int 1951 fgetsock(struct thread *td, int fd, struct socket **spp, u_int *fflagp) 1952 { 1953 struct file *fp; 1954 int error; 1955 1956 *spp = NULL; 1957 if (fflagp != NULL) 1958 *fflagp = 0; 1959 if ((error = _fget(td, fd, &fp, 0, 0)) != 0) 1960 return (error); 1961 if (fp->f_type != DTYPE_SOCKET) { 1962 error = ENOTSOCK; 1963 } else { 1964 *spp = fp->f_data; 1965 if (fflagp) 1966 *fflagp = fp->f_flag; 1967 soref(*spp); 1968 } 1969 FILEDESC_UNLOCK(td->td_proc->p_fd); 1970 return (error); 1971 } 1972 1973 /* 1974 * Drop the reference count on the the socket and XXX release the SX lock in 1975 * the future. The last reference closes the socket. 1976 */ 1977 void 1978 fputsock(struct socket *so) 1979 { 1980 1981 sorele(so); 1982 } 1983 1984 /* 1985 * Drop reference on struct file passed in, may call closef if the 1986 * reference hits zero. 1987 * Expects struct file locked, and will unlock it. 1988 */ 1989 int 1990 fdrop_locked(fp, td) 1991 struct file *fp; 1992 struct thread *td; 1993 { 1994 struct flock lf; 1995 struct vnode *vp; 1996 int error; 1997 1998 FILE_LOCK_ASSERT(fp, MA_OWNED); 1999 2000 if (--fp->f_count > 0) { 2001 FILE_UNLOCK(fp); 2002 return (0); 2003 } 2004 mtx_lock(&Giant); 2005 if (fp->f_count < 0) 2006 panic("fdrop: count < 0"); 2007 if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE) { 2008 lf.l_whence = SEEK_SET; 2009 lf.l_start = 0; 2010 lf.l_len = 0; 2011 lf.l_type = F_UNLCK; 2012 vp = fp->f_data; 2013 FILE_UNLOCK(fp); 2014 (void) VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 2015 } else 2016 FILE_UNLOCK(fp); 2017 if (fp->f_ops != &badfileops) 2018 error = fo_close(fp, td); 2019 else 2020 error = 0; 2021 ffree(fp); 2022 mtx_unlock(&Giant); 2023 return (error); 2024 } 2025 2026 /* 2027 * Apply an advisory lock on a file descriptor. 2028 * 2029 * Just attempt to get a record lock of the requested type on 2030 * the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2031 */ 2032 #ifndef _SYS_SYSPROTO_H_ 2033 struct flock_args { 2034 int fd; 2035 int how; 2036 }; 2037 #endif 2038 /* 2039 * MPSAFE 2040 */ 2041 /* ARGSUSED */ 2042 int 2043 flock(td, uap) 2044 struct thread *td; 2045 struct flock_args *uap; 2046 { 2047 struct file *fp; 2048 struct vnode *vp; 2049 struct flock lf; 2050 int error; 2051 2052 if ((error = fget(td, uap->fd, &fp)) != 0) 2053 return (error); 2054 if (fp->f_type != DTYPE_VNODE) { 2055 fdrop(fp, td); 2056 return (EOPNOTSUPP); 2057 } 2058 2059 mtx_lock(&Giant); 2060 vp = fp->f_data; 2061 lf.l_whence = SEEK_SET; 2062 lf.l_start = 0; 2063 lf.l_len = 0; 2064 if (uap->how & LOCK_UN) { 2065 lf.l_type = F_UNLCK; 2066 FILE_LOCK(fp); 2067 fp->f_flag &= ~FHASLOCK; 2068 FILE_UNLOCK(fp); 2069 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 2070 goto done2; 2071 } 2072 if (uap->how & LOCK_EX) 2073 lf.l_type = F_WRLCK; 2074 else if (uap->how & LOCK_SH) 2075 lf.l_type = F_RDLCK; 2076 else { 2077 error = EBADF; 2078 goto done2; 2079 } 2080 FILE_LOCK(fp); 2081 fp->f_flag |= FHASLOCK; 2082 FILE_UNLOCK(fp); 2083 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 2084 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 2085 done2: 2086 fdrop(fp, td); 2087 mtx_unlock(&Giant); 2088 return (error); 2089 } 2090 2091 /* 2092 * File Descriptor pseudo-device driver (/dev/fd/). 2093 * 2094 * Opening minor device N dup()s the file (if any) connected to file 2095 * descriptor N belonging to the calling process. Note that this driver 2096 * consists of only the ``open()'' routine, because all subsequent 2097 * references to this file will be direct to the other driver. 2098 */ 2099 /* ARGSUSED */ 2100 static int 2101 fdopen(dev, mode, type, td) 2102 dev_t dev; 2103 int mode, type; 2104 struct thread *td; 2105 { 2106 2107 /* 2108 * XXX Kludge: set curthread->td_dupfd to contain the value of the 2109 * the file descriptor being sought for duplication. The error 2110 * return ensures that the vnode for this device will be released 2111 * by vn_open. Open will detect this special error and take the 2112 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 2113 * will simply report the error. 2114 */ 2115 td->td_dupfd = dev2unit(dev); 2116 return (ENODEV); 2117 } 2118 2119 /* 2120 * Duplicate the specified descriptor to a free descriptor. 2121 */ 2122 int 2123 dupfdopen(td, fdp, indx, dfd, mode, error) 2124 struct thread *td; 2125 struct filedesc *fdp; 2126 int indx, dfd; 2127 int mode; 2128 int error; 2129 { 2130 struct file *wfp; 2131 struct file *fp; 2132 2133 /* 2134 * If the to-be-dup'd fd number is greater than the allowed number 2135 * of file descriptors, or the fd to be dup'd has already been 2136 * closed, then reject. 2137 */ 2138 FILEDESC_LOCK(fdp); 2139 if (dfd < 0 || dfd >= fdp->fd_nfiles || 2140 (wfp = fdp->fd_ofiles[dfd]) == NULL) { 2141 FILEDESC_UNLOCK(fdp); 2142 return (EBADF); 2143 } 2144 2145 /* 2146 * There are two cases of interest here. 2147 * 2148 * For ENODEV simply dup (dfd) to file descriptor 2149 * (indx) and return. 2150 * 2151 * For ENXIO steal away the file structure from (dfd) and 2152 * store it in (indx). (dfd) is effectively closed by 2153 * this operation. 2154 * 2155 * Any other error code is just returned. 2156 */ 2157 switch (error) { 2158 case ENODEV: 2159 /* 2160 * Check that the mode the file is being opened for is a 2161 * subset of the mode of the existing descriptor. 2162 */ 2163 FILE_LOCK(wfp); 2164 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) { 2165 FILE_UNLOCK(wfp); 2166 FILEDESC_UNLOCK(fdp); 2167 return (EACCES); 2168 } 2169 fp = fdp->fd_ofiles[indx]; 2170 #if 0 2171 if (fp && fdp->fd_ofileflags[indx] & UF_MAPPED) 2172 (void) munmapfd(td, indx); 2173 #endif 2174 fdp->fd_ofiles[indx] = wfp; 2175 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 2176 fhold_locked(wfp); 2177 FILE_UNLOCK(wfp); 2178 if (indx > fdp->fd_lastfile) 2179 fdp->fd_lastfile = indx; 2180 if (fp != NULL) 2181 FILE_LOCK(fp); 2182 FILEDESC_UNLOCK(fdp); 2183 /* 2184 * We now own the reference to fp that the ofiles[] array 2185 * used to own. Release it. 2186 */ 2187 if (fp != NULL) 2188 fdrop_locked(fp, td); 2189 return (0); 2190 2191 case ENXIO: 2192 /* 2193 * Steal away the file pointer from dfd and stuff it into indx. 2194 */ 2195 fp = fdp->fd_ofiles[indx]; 2196 #if 0 2197 if (fp && fdp->fd_ofileflags[indx] & UF_MAPPED) 2198 (void) munmapfd(td, indx); 2199 #endif 2200 fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd]; 2201 fdp->fd_ofiles[dfd] = NULL; 2202 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 2203 fdp->fd_ofileflags[dfd] = 0; 2204 2205 /* 2206 * Complete the clean up of the filedesc structure by 2207 * recomputing the various hints. 2208 */ 2209 if (indx > fdp->fd_lastfile) { 2210 fdp->fd_lastfile = indx; 2211 } else { 2212 while (fdp->fd_lastfile > 0 && 2213 fdp->fd_ofiles[fdp->fd_lastfile] == NULL) { 2214 fdp->fd_lastfile--; 2215 } 2216 if (dfd < fdp->fd_freefile) 2217 fdp->fd_freefile = dfd; 2218 } 2219 if (fp != NULL) 2220 FILE_LOCK(fp); 2221 FILEDESC_UNLOCK(fdp); 2222 2223 /* 2224 * we now own the reference to fp that the ofiles[] array 2225 * used to own. Release it. 2226 */ 2227 if (fp != NULL) 2228 fdrop_locked(fp, td); 2229 return (0); 2230 2231 default: 2232 FILEDESC_UNLOCK(fdp); 2233 return (error); 2234 } 2235 /* NOTREACHED */ 2236 } 2237 2238 2239 struct filedesc_to_leader * 2240 filedesc_to_leader_alloc(struct filedesc_to_leader *old, 2241 struct filedesc *fdp, 2242 struct proc *leader) 2243 { 2244 struct filedesc_to_leader *fdtol; 2245 2246 MALLOC(fdtol, struct filedesc_to_leader *, 2247 sizeof(struct filedesc_to_leader), 2248 M_FILEDESC_TO_LEADER, 2249 M_WAITOK); 2250 fdtol->fdl_refcount = 1; 2251 fdtol->fdl_holdcount = 0; 2252 fdtol->fdl_wakeup = 0; 2253 fdtol->fdl_leader = leader; 2254 if (old != NULL) { 2255 FILEDESC_LOCK(fdp); 2256 fdtol->fdl_next = old->fdl_next; 2257 fdtol->fdl_prev = old; 2258 old->fdl_next = fdtol; 2259 fdtol->fdl_next->fdl_prev = fdtol; 2260 FILEDESC_UNLOCK(fdp); 2261 } else { 2262 fdtol->fdl_next = fdtol; 2263 fdtol->fdl_prev = fdtol; 2264 } 2265 return fdtol; 2266 } 2267 2268 /* 2269 * Get file structures. 2270 */ 2271 static int 2272 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 2273 { 2274 struct xfile xf; 2275 struct filedesc *fdp; 2276 struct file *fp; 2277 struct proc *p; 2278 int error, n; 2279 2280 sysctl_wire_old_buffer(req, 0); 2281 if (req->oldptr == NULL) { 2282 n = 16; /* A slight overestimate. */ 2283 sx_slock(&filelist_lock); 2284 LIST_FOREACH(fp, &filehead, f_list) { 2285 /* 2286 * We should grab the lock, but this is an 2287 * estimate, so does it really matter? 2288 */ 2289 /* mtx_lock(fp->f_mtxp); */ 2290 n += fp->f_count; 2291 /* mtx_unlock(f->f_mtxp); */ 2292 } 2293 sx_sunlock(&filelist_lock); 2294 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 2295 } 2296 error = 0; 2297 bzero(&xf, sizeof(xf)); 2298 xf.xf_size = sizeof(xf); 2299 sx_slock(&allproc_lock); 2300 LIST_FOREACH(p, &allproc, p_list) { 2301 PROC_LOCK(p); 2302 xf.xf_pid = p->p_pid; 2303 xf.xf_uid = p->p_ucred->cr_uid; 2304 PROC_UNLOCK(p); 2305 mtx_lock(&fdesc_mtx); 2306 if ((fdp = p->p_fd) == NULL) { 2307 mtx_unlock(&fdesc_mtx); 2308 continue; 2309 } 2310 FILEDESC_LOCK(fdp); 2311 for (n = 0; n < fdp->fd_nfiles; ++n) { 2312 if ((fp = fdp->fd_ofiles[n]) == NULL) 2313 continue; 2314 xf.xf_fd = n; 2315 xf.xf_file = fp; 2316 xf.xf_data = fp->f_data; 2317 xf.xf_type = fp->f_type; 2318 xf.xf_count = fp->f_count; 2319 xf.xf_msgcount = fp->f_msgcount; 2320 xf.xf_offset = fp->f_offset; 2321 xf.xf_flag = fp->f_flag; 2322 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 2323 if (error) 2324 break; 2325 } 2326 FILEDESC_UNLOCK(fdp); 2327 mtx_unlock(&fdesc_mtx); 2328 if (error) 2329 break; 2330 } 2331 sx_sunlock(&allproc_lock); 2332 return (error); 2333 } 2334 2335 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD, 2336 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 2337 2338 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 2339 &maxfilesperproc, 0, "Maximum files allowed open per process"); 2340 2341 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 2342 &maxfiles, 0, "Maximum number of files"); 2343 2344 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 2345 &nfiles, 0, "System-wide number of open files"); 2346 2347 static void 2348 fildesc_drvinit(void *unused) 2349 { 2350 dev_t dev; 2351 2352 dev = make_dev(&fildesc_cdevsw, 0, UID_ROOT, GID_WHEEL, 0666, "fd/0"); 2353 make_dev_alias(dev, "stdin"); 2354 dev = make_dev(&fildesc_cdevsw, 1, UID_ROOT, GID_WHEEL, 0666, "fd/1"); 2355 make_dev_alias(dev, "stdout"); 2356 dev = make_dev(&fildesc_cdevsw, 2, UID_ROOT, GID_WHEEL, 0666, "fd/2"); 2357 make_dev_alias(dev, "stderr"); 2358 } 2359 2360 static fo_rdwr_t badfo_readwrite; 2361 static fo_ioctl_t badfo_ioctl; 2362 static fo_poll_t badfo_poll; 2363 static fo_kqfilter_t badfo_kqfilter; 2364 static fo_stat_t badfo_stat; 2365 static fo_close_t badfo_close; 2366 2367 struct fileops badfileops = { 2368 badfo_readwrite, 2369 badfo_readwrite, 2370 badfo_ioctl, 2371 badfo_poll, 2372 badfo_kqfilter, 2373 badfo_stat, 2374 badfo_close, 2375 0 2376 }; 2377 2378 static int 2379 badfo_readwrite(fp, uio, active_cred, flags, td) 2380 struct file *fp; 2381 struct uio *uio; 2382 struct ucred *active_cred; 2383 struct thread *td; 2384 int flags; 2385 { 2386 2387 return (EBADF); 2388 } 2389 2390 static int 2391 badfo_ioctl(fp, com, data, active_cred, td) 2392 struct file *fp; 2393 u_long com; 2394 void *data; 2395 struct ucred *active_cred; 2396 struct thread *td; 2397 { 2398 2399 return (EBADF); 2400 } 2401 2402 static int 2403 badfo_poll(fp, events, active_cred, td) 2404 struct file *fp; 2405 int events; 2406 struct ucred *active_cred; 2407 struct thread *td; 2408 { 2409 2410 return (0); 2411 } 2412 2413 static int 2414 badfo_kqfilter(fp, kn) 2415 struct file *fp; 2416 struct knote *kn; 2417 { 2418 2419 return (0); 2420 } 2421 2422 static int 2423 badfo_stat(fp, sb, active_cred, td) 2424 struct file *fp; 2425 struct stat *sb; 2426 struct ucred *active_cred; 2427 struct thread *td; 2428 { 2429 2430 return (EBADF); 2431 } 2432 2433 static int 2434 badfo_close(fp, td) 2435 struct file *fp; 2436 struct thread *td; 2437 { 2438 2439 return (EBADF); 2440 } 2441 2442 SYSINIT(fildescdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR, 2443 fildesc_drvinit,NULL) 2444 2445 static void filelistinit(void *); 2446 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL) 2447 2448 /* ARGSUSED*/ 2449 static void 2450 filelistinit(dummy) 2451 void *dummy; 2452 { 2453 2454 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 2455 NULL, NULL, UMA_ALIGN_PTR, 0); 2456 sx_init(&filelist_lock, "filelist lock"); 2457 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 2458 } 2459