1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 39 * $Id: kern_descrip.c,v 1.31 1996/08/15 16:33:32 smpatel Exp $ 40 */ 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/sysproto.h> 45 #include <sys/conf.h> 46 #include <sys/filedesc.h> 47 #include <sys/kernel.h> 48 #include <sys/sysctl.h> 49 #include <sys/vnode.h> 50 #include <sys/proc.h> 51 #include <sys/file.h> 52 #include <sys/socketvar.h> 53 #include <sys/stat.h> 54 #include <sys/filio.h> 55 #include <sys/ttycom.h> 56 #include <sys/fcntl.h> 57 #include <sys/malloc.h> 58 #include <sys/unistd.h> 59 #include <sys/resourcevar.h> 60 #include <sys/pipe.h> 61 62 #include <vm/vm.h> 63 #include <vm/vm_extern.h> 64 65 #ifdef DEVFS 66 #include <sys/devfsext.h> 67 #endif /*DEVFS*/ 68 69 static d_open_t fdopen; 70 #define NUMFDESC 64 71 72 #define CDEV_MAJOR 22 73 static struct cdevsw fildesc_cdevsw = 74 { fdopen, noclose, noread, nowrite, /*22*/ 75 noioc, nostop, nullreset, nodevtotty,/*fd(!=Fd)*/ 76 noselect, nommap, nostrat }; 77 78 static int finishdup(struct filedesc *fdp, int old, int new, int *retval); 79 /* 80 * Descriptor management. 81 */ 82 struct filelist filehead; /* head of list of open files */ 83 int nfiles; /* actual number of open files */ 84 extern int cmask; 85 86 /* 87 * System calls on descriptors. 88 */ 89 #ifndef _SYS_SYSPROTO_H_ 90 struct getdtablesize_args { 91 int dummy; 92 }; 93 #endif 94 /* ARGSUSED */ 95 int 96 getdtablesize(p, uap, retval) 97 struct proc *p; 98 struct getdtablesize_args *uap; 99 int *retval; 100 { 101 102 *retval = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc); 103 return (0); 104 } 105 106 /* 107 * Duplicate a file descriptor to a particular value. 108 */ 109 #ifndef _SYS_SYSPROTO_H_ 110 struct dup2_args { 111 u_int from; 112 u_int to; 113 }; 114 #endif 115 /* ARGSUSED */ 116 int 117 dup2(p, uap, retval) 118 struct proc *p; 119 struct dup2_args *uap; 120 int *retval; 121 { 122 register struct filedesc *fdp = p->p_fd; 123 register u_int old = uap->from, new = uap->to; 124 int i, error; 125 126 if (old >= fdp->fd_nfiles || 127 fdp->fd_ofiles[old] == NULL || 128 new >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur || 129 new >= maxfilesperproc) 130 return (EBADF); 131 if (old == new) { 132 *retval = new; 133 return (0); 134 } 135 if (new >= fdp->fd_nfiles) { 136 if ((error = fdalloc(p, new, &i))) 137 return (error); 138 if (new != i) 139 panic("dup2: fdalloc"); 140 } else if (fdp->fd_ofiles[new]) { 141 if (fdp->fd_ofileflags[new] & UF_MAPPED) 142 (void) munmapfd(p, new); 143 /* 144 * dup2() must succeed even if the close has an error. 145 */ 146 (void) closef(fdp->fd_ofiles[new], p); 147 } 148 return (finishdup(fdp, (int)old, (int)new, retval)); 149 } 150 151 /* 152 * Duplicate a file descriptor. 153 */ 154 #ifndef _SYS_SYSPROTO_H_ 155 struct dup_args { 156 u_int fd; 157 }; 158 #endif 159 /* ARGSUSED */ 160 int 161 dup(p, uap, retval) 162 struct proc *p; 163 struct dup_args *uap; 164 int *retval; 165 { 166 register struct filedesc *fdp; 167 u_int old; 168 int new, error; 169 170 old = uap->fd; 171 172 #if 0 173 /* 174 * XXX Compatibility 175 */ 176 if (old &~ 077) { uap->fd &= 077; return (dup2(p, uap, retval)); } 177 #endif 178 179 fdp = p->p_fd; 180 if (old >= fdp->fd_nfiles || fdp->fd_ofiles[old] == NULL) 181 return (EBADF); 182 if ((error = fdalloc(p, 0, &new))) 183 return (error); 184 return (finishdup(fdp, (int)old, new, retval)); 185 } 186 187 /* 188 * The file control system call. 189 */ 190 #ifndef _SYS_SYSPROTO_H_ 191 struct fcntl_args { 192 int fd; 193 int cmd; 194 int arg; 195 }; 196 #endif 197 /* ARGSUSED */ 198 int 199 fcntl(p, uap, retval) 200 struct proc *p; 201 register struct fcntl_args *uap; 202 int *retval; 203 { 204 register struct filedesc *fdp = p->p_fd; 205 register struct file *fp; 206 register char *pop; 207 struct vnode *vp; 208 int i, tmp, error, flg = F_POSIX; 209 struct flock fl; 210 u_int newmin; 211 212 if ((unsigned)uap->fd >= fdp->fd_nfiles || 213 (fp = fdp->fd_ofiles[uap->fd]) == NULL) 214 return (EBADF); 215 pop = &fdp->fd_ofileflags[uap->fd]; 216 switch (uap->cmd) { 217 218 case F_DUPFD: 219 newmin = uap->arg; 220 if (newmin >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur || 221 newmin >= maxfilesperproc) 222 return (EINVAL); 223 if ((error = fdalloc(p, newmin, &i))) 224 return (error); 225 return (finishdup(fdp, uap->fd, i, retval)); 226 227 case F_GETFD: 228 *retval = *pop & 1; 229 return (0); 230 231 case F_SETFD: 232 *pop = (*pop &~ 1) | (uap->arg & 1); 233 return (0); 234 235 case F_GETFL: 236 *retval = OFLAGS(fp->f_flag); 237 return (0); 238 239 case F_SETFL: 240 fp->f_flag &= ~FCNTLFLAGS; 241 fp->f_flag |= FFLAGS(uap->arg) & FCNTLFLAGS; 242 tmp = fp->f_flag & FNONBLOCK; 243 error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p); 244 if (error) 245 return (error); 246 tmp = fp->f_flag & FASYNC; 247 error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, (caddr_t)&tmp, p); 248 if (!error) 249 return (0); 250 fp->f_flag &= ~FNONBLOCK; 251 tmp = 0; 252 (void) (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p); 253 return (error); 254 255 case F_GETOWN: 256 if (fp->f_type == DTYPE_SOCKET) { 257 *retval = ((struct socket *)fp->f_data)->so_pgid; 258 return (0); 259 } 260 error = (*fp->f_ops->fo_ioctl) 261 (fp, TIOCGPGRP, (caddr_t)retval, p); 262 *retval = -*retval; 263 return (error); 264 265 case F_SETOWN: 266 if (fp->f_type == DTYPE_SOCKET) { 267 ((struct socket *)fp->f_data)->so_pgid = uap->arg; 268 return (0); 269 } 270 if (uap->arg <= 0) { 271 uap->arg = -uap->arg; 272 } else { 273 struct proc *p1 = pfind(uap->arg); 274 if (p1 == 0) 275 return (ESRCH); 276 uap->arg = p1->p_pgrp->pg_id; 277 } 278 return ((*fp->f_ops->fo_ioctl) 279 (fp, TIOCSPGRP, (caddr_t)&uap->arg, p)); 280 281 case F_SETLKW: 282 flg |= F_WAIT; 283 /* Fall into F_SETLK */ 284 285 case F_SETLK: 286 if (fp->f_type != DTYPE_VNODE) 287 return (EBADF); 288 vp = (struct vnode *)fp->f_data; 289 /* Copy in the lock structure */ 290 error = copyin((caddr_t)uap->arg, (caddr_t)&fl, sizeof (fl)); 291 if (error) 292 return (error); 293 if (fl.l_whence == SEEK_CUR) 294 fl.l_start += fp->f_offset; 295 switch (fl.l_type) { 296 297 case F_RDLCK: 298 if ((fp->f_flag & FREAD) == 0) 299 return (EBADF); 300 p->p_flag |= P_ADVLOCK; 301 return (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &fl, flg)); 302 303 case F_WRLCK: 304 if ((fp->f_flag & FWRITE) == 0) 305 return (EBADF); 306 p->p_flag |= P_ADVLOCK; 307 return (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &fl, flg)); 308 309 case F_UNLCK: 310 return (VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &fl, 311 F_POSIX)); 312 313 default: 314 return (EINVAL); 315 } 316 317 case F_GETLK: 318 if (fp->f_type != DTYPE_VNODE) 319 return (EBADF); 320 vp = (struct vnode *)fp->f_data; 321 /* Copy in the lock structure */ 322 error = copyin((caddr_t)uap->arg, (caddr_t)&fl, sizeof (fl)); 323 if (error) 324 return (error); 325 if (fl.l_whence == SEEK_CUR) 326 fl.l_start += fp->f_offset; 327 if ((error = VOP_ADVLOCK(vp,(caddr_t)p,F_GETLK,&fl,F_POSIX))) 328 return (error); 329 return (copyout((caddr_t)&fl, (caddr_t)uap->arg, sizeof (fl))); 330 331 default: 332 return (EINVAL); 333 } 334 /* NOTREACHED */ 335 } 336 337 /* 338 * Common code for dup, dup2, and fcntl(F_DUPFD). 339 */ 340 static int 341 finishdup(fdp, old, new, retval) 342 register struct filedesc *fdp; 343 register int old, new, *retval; 344 { 345 register struct file *fp; 346 347 fp = fdp->fd_ofiles[old]; 348 fdp->fd_ofiles[new] = fp; 349 fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] &~ UF_EXCLOSE; 350 fp->f_count++; 351 if (new > fdp->fd_lastfile) 352 fdp->fd_lastfile = new; 353 *retval = new; 354 return (0); 355 } 356 357 /* 358 * Close a file descriptor. 359 */ 360 #ifndef _SYS_SYSPROTO_H_ 361 struct close_args { 362 int fd; 363 }; 364 #endif 365 /* ARGSUSED */ 366 int 367 close(p, uap, retval) 368 struct proc *p; 369 struct close_args *uap; 370 int *retval; 371 { 372 register struct filedesc *fdp = p->p_fd; 373 register struct file *fp; 374 register int fd = uap->fd; 375 register u_char *pf; 376 377 if ((unsigned)fd >= fdp->fd_nfiles || 378 (fp = fdp->fd_ofiles[fd]) == NULL) 379 return (EBADF); 380 pf = (u_char *)&fdp->fd_ofileflags[fd]; 381 if (*pf & UF_MAPPED) 382 (void) munmapfd(p, fd); 383 fdp->fd_ofiles[fd] = NULL; 384 while (fdp->fd_lastfile > 0 && fdp->fd_ofiles[fdp->fd_lastfile] == NULL) 385 fdp->fd_lastfile--; 386 if (fd < fdp->fd_freefile) 387 fdp->fd_freefile = fd; 388 *pf = 0; 389 return (closef(fp, p)); 390 } 391 392 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 393 /* 394 * Return status information about a file descriptor. 395 */ 396 #ifndef _SYS_SYSPROTO_H_ 397 struct ofstat_args { 398 int fd; 399 struct ostat *sb; 400 }; 401 #endif 402 /* ARGSUSED */ 403 int 404 ofstat(p, uap, retval) 405 struct proc *p; 406 register struct ofstat_args *uap; 407 int *retval; 408 { 409 register struct filedesc *fdp = p->p_fd; 410 register struct file *fp; 411 struct stat ub; 412 struct ostat oub; 413 int error; 414 415 if ((unsigned)uap->fd >= fdp->fd_nfiles || 416 (fp = fdp->fd_ofiles[uap->fd]) == NULL) 417 return (EBADF); 418 switch (fp->f_type) { 419 420 case DTYPE_VNODE: 421 error = vn_stat((struct vnode *)fp->f_data, &ub, p); 422 break; 423 424 case DTYPE_SOCKET: 425 error = soo_stat((struct socket *)fp->f_data, &ub); 426 break; 427 428 #ifndef OLD_PIPE 429 case DTYPE_PIPE: 430 error = pipe_stat((struct pipe *)fp->f_data, &ub); 431 break; 432 #endif 433 434 default: 435 panic("ofstat"); 436 /*NOTREACHED*/ 437 } 438 cvtstat(&ub, &oub); 439 if (error == 0) 440 error = copyout((caddr_t)&oub, (caddr_t)uap->sb, sizeof (oub)); 441 return (error); 442 } 443 #endif /* COMPAT_43 || COMPAT_SUNOS */ 444 445 /* 446 * Return status information about a file descriptor. 447 */ 448 #ifndef _SYS_SYSPROTO_H_ 449 struct fstat_args { 450 int fd; 451 struct stat *sb; 452 }; 453 #endif 454 /* ARGSUSED */ 455 int 456 fstat(p, uap, retval) 457 struct proc *p; 458 register struct fstat_args *uap; 459 int *retval; 460 { 461 register struct filedesc *fdp = p->p_fd; 462 register struct file *fp; 463 struct stat ub; 464 int error; 465 466 if ((unsigned)uap->fd >= fdp->fd_nfiles || 467 (fp = fdp->fd_ofiles[uap->fd]) == NULL) 468 return (EBADF); 469 switch (fp->f_type) { 470 471 case DTYPE_VNODE: 472 error = vn_stat((struct vnode *)fp->f_data, &ub, p); 473 break; 474 475 case DTYPE_SOCKET: 476 error = soo_stat((struct socket *)fp->f_data, &ub); 477 break; 478 479 #ifndef OLD_PIPE 480 case DTYPE_PIPE: 481 error = pipe_stat((struct pipe *)fp->f_data, &ub); 482 break; 483 #endif 484 485 default: 486 panic("fstat"); 487 /*NOTREACHED*/ 488 } 489 if (error == 0) 490 error = copyout((caddr_t)&ub, (caddr_t)uap->sb, sizeof (ub)); 491 return (error); 492 } 493 494 /* 495 * Return pathconf information about a file descriptor. 496 */ 497 #ifndef _SYS_SYSPROTO_H_ 498 struct fpathconf_args { 499 int fd; 500 int name; 501 }; 502 #endif 503 /* ARGSUSED */ 504 int 505 fpathconf(p, uap, retval) 506 struct proc *p; 507 register struct fpathconf_args *uap; 508 int *retval; 509 { 510 struct filedesc *fdp = p->p_fd; 511 struct file *fp; 512 struct vnode *vp; 513 514 if ((unsigned)uap->fd >= fdp->fd_nfiles || 515 (fp = fdp->fd_ofiles[uap->fd]) == NULL) 516 return (EBADF); 517 switch (fp->f_type) { 518 519 #ifndef OLD_PIPE 520 case DTYPE_PIPE: 521 #endif 522 case DTYPE_SOCKET: 523 if (uap->name != _PC_PIPE_BUF) 524 return (EINVAL); 525 *retval = PIPE_BUF; 526 return (0); 527 528 case DTYPE_VNODE: 529 vp = (struct vnode *)fp->f_data; 530 return (VOP_PATHCONF(vp, uap->name, retval)); 531 532 default: 533 panic("fpathconf"); 534 } 535 /*NOTREACHED*/ 536 } 537 538 /* 539 * Allocate a file descriptor for the process. 540 */ 541 static int fdexpand; 542 SYSCTL_INT(_debug, OID_AUTO, fdexpand, CTLFLAG_RD, &fdexpand, 0, ""); 543 544 int 545 fdalloc(p, want, result) 546 struct proc *p; 547 int want; 548 int *result; 549 { 550 register struct filedesc *fdp = p->p_fd; 551 register int i; 552 int lim, last, nfiles; 553 struct file **newofile; 554 char *newofileflags; 555 556 /* 557 * Search for a free descriptor starting at the higher 558 * of want or fd_freefile. If that fails, consider 559 * expanding the ofile array. 560 */ 561 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc); 562 for (;;) { 563 last = min(fdp->fd_nfiles, lim); 564 if ((i = want) < fdp->fd_freefile) 565 i = fdp->fd_freefile; 566 for (; i < last; i++) { 567 if (fdp->fd_ofiles[i] == NULL) { 568 fdp->fd_ofileflags[i] = 0; 569 if (i > fdp->fd_lastfile) 570 fdp->fd_lastfile = i; 571 if (want <= fdp->fd_freefile) 572 fdp->fd_freefile = i; 573 *result = i; 574 return (0); 575 } 576 } 577 578 /* 579 * No space in current array. Expand? 580 */ 581 if (fdp->fd_nfiles >= lim) 582 return (EMFILE); 583 if (fdp->fd_nfiles < NDEXTENT) 584 nfiles = NDEXTENT; 585 else 586 nfiles = 2 * fdp->fd_nfiles; 587 MALLOC(newofile, struct file **, nfiles * OFILESIZE, 588 M_FILEDESC, M_WAITOK); 589 newofileflags = (char *) &newofile[nfiles]; 590 /* 591 * Copy the existing ofile and ofileflags arrays 592 * and zero the new portion of each array. 593 */ 594 bcopy(fdp->fd_ofiles, newofile, 595 (i = sizeof(struct file *) * fdp->fd_nfiles)); 596 bzero((char *)newofile + i, nfiles * sizeof(struct file *) - i); 597 bcopy(fdp->fd_ofileflags, newofileflags, 598 (i = sizeof(char) * fdp->fd_nfiles)); 599 bzero(newofileflags + i, nfiles * sizeof(char) - i); 600 if (fdp->fd_nfiles > NDFILE) 601 FREE(fdp->fd_ofiles, M_FILEDESC); 602 fdp->fd_ofiles = newofile; 603 fdp->fd_ofileflags = newofileflags; 604 fdp->fd_nfiles = nfiles; 605 fdexpand++; 606 } 607 return (0); 608 } 609 610 /* 611 * Check to see whether n user file descriptors 612 * are available to the process p. 613 */ 614 int 615 fdavail(p, n) 616 struct proc *p; 617 register int n; 618 { 619 register struct filedesc *fdp = p->p_fd; 620 register struct file **fpp; 621 register int i, lim, last; 622 623 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc); 624 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) 625 return (1); 626 627 last = min(fdp->fd_nfiles, lim); 628 fpp = &fdp->fd_ofiles[fdp->fd_freefile]; 629 for (i = last - fdp->fd_freefile; --i >= 0; fpp++) 630 if (*fpp == NULL && --n <= 0) 631 return (1); 632 return (0); 633 } 634 635 /* 636 * Create a new open file structure and allocate 637 * a file decriptor for the process that refers to it. 638 */ 639 int 640 falloc(p, resultfp, resultfd) 641 register struct proc *p; 642 struct file **resultfp; 643 int *resultfd; 644 { 645 register struct file *fp, *fq; 646 int error, i; 647 648 if ((error = fdalloc(p, 0, &i))) 649 return (error); 650 if (nfiles >= maxfiles) { 651 tablefull("file"); 652 return (ENFILE); 653 } 654 /* 655 * Allocate a new file descriptor. 656 * If the process has file descriptor zero open, add to the list 657 * of open files at that point, otherwise put it at the front of 658 * the list of open files. 659 */ 660 nfiles++; 661 MALLOC(fp, struct file *, sizeof(struct file), M_FILE, M_WAITOK); 662 bzero(fp, sizeof(struct file)); 663 if ((fq = p->p_fd->fd_ofiles[0])) { 664 LIST_INSERT_AFTER(fq, fp, f_list); 665 } else { 666 LIST_INSERT_HEAD(&filehead, fp, f_list); 667 } 668 p->p_fd->fd_ofiles[i] = fp; 669 fp->f_count = 1; 670 fp->f_cred = p->p_ucred; 671 crhold(fp->f_cred); 672 if (resultfp) 673 *resultfp = fp; 674 if (resultfd) 675 *resultfd = i; 676 return (0); 677 } 678 679 /* 680 * Free a file descriptor. 681 */ 682 void 683 ffree(fp) 684 register struct file *fp; 685 { 686 LIST_REMOVE(fp, f_list); 687 crfree(fp->f_cred); 688 #ifdef DIAGNOSTIC 689 fp->f_count = 0; 690 #endif 691 nfiles--; 692 FREE(fp, M_FILE); 693 } 694 695 /* 696 * Build a new filedesc structure. 697 */ 698 struct filedesc * 699 fdinit(p) 700 struct proc *p; 701 { 702 register struct filedesc0 *newfdp; 703 register struct filedesc *fdp = p->p_fd; 704 705 MALLOC(newfdp, struct filedesc0 *, sizeof(struct filedesc0), 706 M_FILEDESC, M_WAITOK); 707 bzero(newfdp, sizeof(struct filedesc0)); 708 newfdp->fd_fd.fd_cdir = fdp->fd_cdir; 709 VREF(newfdp->fd_fd.fd_cdir); 710 newfdp->fd_fd.fd_rdir = fdp->fd_rdir; 711 if (newfdp->fd_fd.fd_rdir) 712 VREF(newfdp->fd_fd.fd_rdir); 713 714 /* Create the file descriptor table. */ 715 newfdp->fd_fd.fd_refcnt = 1; 716 newfdp->fd_fd.fd_cmask = cmask; 717 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles; 718 newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags; 719 newfdp->fd_fd.fd_nfiles = NDFILE; 720 721 newfdp->fd_fd.fd_freefile = 0; 722 newfdp->fd_fd.fd_lastfile = 0; 723 724 return (&newfdp->fd_fd); 725 } 726 727 /* 728 * Share a filedesc structure. 729 */ 730 struct filedesc * 731 fdshare(p) 732 struct proc *p; 733 { 734 p->p_fd->fd_refcnt++; 735 return (p->p_fd); 736 } 737 738 /* 739 * Copy a filedesc structure. 740 */ 741 struct filedesc * 742 fdcopy(p) 743 struct proc *p; 744 { 745 register struct filedesc *newfdp, *fdp = p->p_fd; 746 register struct file **fpp; 747 register int i; 748 749 MALLOC(newfdp, struct filedesc *, sizeof(struct filedesc0), 750 M_FILEDESC, M_WAITOK); 751 bcopy(fdp, newfdp, sizeof(struct filedesc)); 752 VREF(newfdp->fd_cdir); 753 if (newfdp->fd_rdir) 754 VREF(newfdp->fd_rdir); 755 newfdp->fd_refcnt = 1; 756 757 /* 758 * If the number of open files fits in the internal arrays 759 * of the open file structure, use them, otherwise allocate 760 * additional memory for the number of descriptors currently 761 * in use. 762 */ 763 if (newfdp->fd_lastfile < NDFILE) { 764 newfdp->fd_ofiles = ((struct filedesc0 *) newfdp)->fd_dfiles; 765 newfdp->fd_ofileflags = 766 ((struct filedesc0 *) newfdp)->fd_dfileflags; 767 i = NDFILE; 768 } else { 769 /* 770 * Compute the smallest multiple of NDEXTENT needed 771 * for the file descriptors currently in use, 772 * allowing the table to shrink. 773 */ 774 i = newfdp->fd_nfiles; 775 while (i > 2 * NDEXTENT && i > newfdp->fd_lastfile * 2) 776 i /= 2; 777 MALLOC(newfdp->fd_ofiles, struct file **, i * OFILESIZE, 778 M_FILEDESC, M_WAITOK); 779 newfdp->fd_ofileflags = (char *) &newfdp->fd_ofiles[i]; 780 } 781 newfdp->fd_nfiles = i; 782 bcopy(fdp->fd_ofiles, newfdp->fd_ofiles, i * sizeof(struct file **)); 783 bcopy(fdp->fd_ofileflags, newfdp->fd_ofileflags, i * sizeof(char)); 784 fpp = newfdp->fd_ofiles; 785 for (i = newfdp->fd_lastfile; i-- >= 0; fpp++) 786 if (*fpp != NULL) 787 (*fpp)->f_count++; 788 return (newfdp); 789 } 790 791 /* 792 * Release a filedesc structure. 793 */ 794 void 795 fdfree(p) 796 struct proc *p; 797 { 798 register struct filedesc *fdp = p->p_fd; 799 struct file **fpp; 800 register int i; 801 802 if (--fdp->fd_refcnt > 0) 803 return; 804 fpp = fdp->fd_ofiles; 805 for (i = fdp->fd_lastfile; i-- >= 0; fpp++) 806 if (*fpp) 807 (void) closef(*fpp, p); 808 if (fdp->fd_nfiles > NDFILE) 809 FREE(fdp->fd_ofiles, M_FILEDESC); 810 vrele(fdp->fd_cdir); 811 if (fdp->fd_rdir) 812 vrele(fdp->fd_rdir); 813 FREE(fdp, M_FILEDESC); 814 } 815 816 /* 817 * Close any files on exec? 818 */ 819 void 820 fdcloseexec(p) 821 struct proc *p; 822 { 823 struct filedesc *fdp = p->p_fd; 824 struct file **fpp; 825 char *fdfp; 826 register int i; 827 828 fpp = fdp->fd_ofiles; 829 fdfp = fdp->fd_ofileflags; 830 for (i = 0; i <= fdp->fd_lastfile; i++, fpp++, fdfp++) 831 if (*fpp != NULL && (*fdfp & UF_EXCLOSE)) { 832 if (*fdfp & UF_MAPPED) 833 (void) munmapfd(p, i); 834 (void) closef(*fpp, p); 835 *fpp = NULL; 836 *fdfp = 0; 837 if (i < fdp->fd_freefile) 838 fdp->fd_freefile = i; 839 } 840 while (fdp->fd_lastfile > 0 && fdp->fd_ofiles[fdp->fd_lastfile] == NULL) 841 fdp->fd_lastfile--; 842 } 843 844 /* 845 * Internal form of close. 846 * Decrement reference count on file structure. 847 * Note: p may be NULL when closing a file 848 * that was being passed in a message. 849 */ 850 int 851 closef(fp, p) 852 register struct file *fp; 853 register struct proc *p; 854 { 855 struct vnode *vp; 856 struct flock lf; 857 int error; 858 859 if (fp == NULL) 860 return (0); 861 /* 862 * POSIX record locking dictates that any close releases ALL 863 * locks owned by this process. This is handled by setting 864 * a flag in the unlock to free ONLY locks obeying POSIX 865 * semantics, and not to free BSD-style file locks. 866 * If the descriptor was in a message, POSIX-style locks 867 * aren't passed with the descriptor. 868 */ 869 if (p && (p->p_flag & P_ADVLOCK) && fp->f_type == DTYPE_VNODE) { 870 lf.l_whence = SEEK_SET; 871 lf.l_start = 0; 872 lf.l_len = 0; 873 lf.l_type = F_UNLCK; 874 vp = (struct vnode *)fp->f_data; 875 (void) VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_POSIX); 876 } 877 if (--fp->f_count > 0) 878 return (0); 879 if (fp->f_count < 0) 880 panic("closef: count < 0"); 881 if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE) { 882 lf.l_whence = SEEK_SET; 883 lf.l_start = 0; 884 lf.l_len = 0; 885 lf.l_type = F_UNLCK; 886 vp = (struct vnode *)fp->f_data; 887 (void) VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 888 } 889 if (fp->f_ops) 890 error = (*fp->f_ops->fo_close)(fp, p); 891 else 892 error = 0; 893 ffree(fp); 894 return (error); 895 } 896 897 /* 898 * Apply an advisory lock on a file descriptor. 899 * 900 * Just attempt to get a record lock of the requested type on 901 * the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0). 902 */ 903 #ifndef _SYS_SYSPROTO_H_ 904 struct flock_args { 905 int fd; 906 int how; 907 }; 908 #endif 909 /* ARGSUSED */ 910 int 911 flock(p, uap, retval) 912 struct proc *p; 913 register struct flock_args *uap; 914 int *retval; 915 { 916 register struct filedesc *fdp = p->p_fd; 917 register struct file *fp; 918 struct vnode *vp; 919 struct flock lf; 920 921 if ((unsigned)uap->fd >= fdp->fd_nfiles || 922 (fp = fdp->fd_ofiles[uap->fd]) == NULL) 923 return (EBADF); 924 if (fp->f_type != DTYPE_VNODE) 925 return (EOPNOTSUPP); 926 vp = (struct vnode *)fp->f_data; 927 lf.l_whence = SEEK_SET; 928 lf.l_start = 0; 929 lf.l_len = 0; 930 if (uap->how & LOCK_UN) { 931 lf.l_type = F_UNLCK; 932 fp->f_flag &= ~FHASLOCK; 933 return (VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK)); 934 } 935 if (uap->how & LOCK_EX) 936 lf.l_type = F_WRLCK; 937 else if (uap->how & LOCK_SH) 938 lf.l_type = F_RDLCK; 939 else 940 return (EBADF); 941 fp->f_flag |= FHASLOCK; 942 if (uap->how & LOCK_NB) 943 return (VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK)); 944 return (VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK|F_WAIT)); 945 } 946 947 /* 948 * File Descriptor pseudo-device driver (/dev/fd/). 949 * 950 * Opening minor device N dup()s the file (if any) connected to file 951 * descriptor N belonging to the calling process. Note that this driver 952 * consists of only the ``open()'' routine, because all subsequent 953 * references to this file will be direct to the other driver. 954 */ 955 /* ARGSUSED */ 956 static int 957 fdopen(dev, mode, type, p) 958 dev_t dev; 959 int mode, type; 960 struct proc *p; 961 { 962 963 /* 964 * XXX Kludge: set curproc->p_dupfd to contain the value of the 965 * the file descriptor being sought for duplication. The error 966 * return ensures that the vnode for this device will be released 967 * by vn_open. Open will detect this special error and take the 968 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 969 * will simply report the error. 970 */ 971 p->p_dupfd = minor(dev); 972 return (ENODEV); 973 } 974 975 /* 976 * Duplicate the specified descriptor to a free descriptor. 977 */ 978 int 979 dupfdopen(fdp, indx, dfd, mode, error) 980 register struct filedesc *fdp; 981 register int indx, dfd; 982 int mode; 983 int error; 984 { 985 register struct file *wfp; 986 struct file *fp; 987 988 /* 989 * If the to-be-dup'd fd number is greater than the allowed number 990 * of file descriptors, or the fd to be dup'd has already been 991 * closed, reject. Note, check for new == old is necessary as 992 * falloc could allocate an already closed to-be-dup'd descriptor 993 * as the new descriptor. 994 */ 995 fp = fdp->fd_ofiles[indx]; 996 if ((u_int)dfd >= fdp->fd_nfiles || 997 (wfp = fdp->fd_ofiles[dfd]) == NULL || fp == wfp) 998 return (EBADF); 999 1000 /* 1001 * There are two cases of interest here. 1002 * 1003 * For ENODEV simply dup (dfd) to file descriptor 1004 * (indx) and return. 1005 * 1006 * For ENXIO steal away the file structure from (dfd) and 1007 * store it in (indx). (dfd) is effectively closed by 1008 * this operation. 1009 * 1010 * Any other error code is just returned. 1011 */ 1012 switch (error) { 1013 case ENODEV: 1014 /* 1015 * Check that the mode the file is being opened for is a 1016 * subset of the mode of the existing descriptor. 1017 */ 1018 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) 1019 return (EACCES); 1020 fdp->fd_ofiles[indx] = wfp; 1021 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 1022 wfp->f_count++; 1023 if (indx > fdp->fd_lastfile) 1024 fdp->fd_lastfile = indx; 1025 return (0); 1026 1027 case ENXIO: 1028 /* 1029 * Steal away the file pointer from dfd, and stuff it into indx. 1030 */ 1031 fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd]; 1032 fdp->fd_ofiles[dfd] = NULL; 1033 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 1034 fdp->fd_ofileflags[dfd] = 0; 1035 /* 1036 * Complete the clean up of the filedesc structure by 1037 * recomputing the various hints. 1038 */ 1039 if (indx > fdp->fd_lastfile) 1040 fdp->fd_lastfile = indx; 1041 else 1042 while (fdp->fd_lastfile > 0 && 1043 fdp->fd_ofiles[fdp->fd_lastfile] == NULL) 1044 fdp->fd_lastfile--; 1045 if (dfd < fdp->fd_freefile) 1046 fdp->fd_freefile = dfd; 1047 return (0); 1048 1049 default: 1050 return (error); 1051 } 1052 /* NOTREACHED */ 1053 } 1054 1055 /* 1056 * Get file structures. 1057 */ 1058 static int 1059 sysctl_kern_file SYSCTL_HANDLER_ARGS 1060 { 1061 int error; 1062 struct file *fp; 1063 1064 if (!req->oldptr) { 1065 /* 1066 * overestimate by 10 files 1067 */ 1068 return (SYSCTL_OUT(req, 0, sizeof(filehead) + 1069 (nfiles + 10) * sizeof(struct file))); 1070 } 1071 1072 error = SYSCTL_OUT(req, (caddr_t)&filehead, sizeof(filehead)); 1073 if (error) 1074 return (error); 1075 1076 /* 1077 * followed by an array of file structures 1078 */ 1079 for (fp = filehead.lh_first; fp != NULL; fp = fp->f_list.le_next) { 1080 error = SYSCTL_OUT(req, (caddr_t)fp, sizeof (struct file)); 1081 if (error) 1082 return (error); 1083 } 1084 return (0); 1085 } 1086 1087 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD, 1088 0, 0, sysctl_kern_file, "S,file", ""); 1089 1090 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, 1091 CTLFLAG_RW, &maxfilesperproc, 0, ""); 1092 1093 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, &maxfiles, 0, ""); 1094 1095 static fildesc_devsw_installed = 0; 1096 #ifdef DEVFS 1097 static void *devfs_token_stdin; 1098 static void *devfs_token_stdout; 1099 static void *devfs_token_stderr; 1100 static void *devfs_token_fildesc[NUMFDESC]; 1101 #endif 1102 1103 static void fildesc_drvinit(void *unused) 1104 { 1105 dev_t dev; 1106 #ifdef DEVFS 1107 int fd; 1108 #endif 1109 1110 if( ! fildesc_devsw_installed ) { 1111 dev = makedev(CDEV_MAJOR,0); 1112 cdevsw_add(&dev,&fildesc_cdevsw,NULL); 1113 fildesc_devsw_installed = 1; 1114 #ifdef DEVFS 1115 for (fd = 0; fd < NUMFDESC; fd++) 1116 devfs_token_fildesc[fd] = 1117 devfs_add_devswf(&fildesc_cdevsw, fd, DV_CHR, 1118 UID_BIN, GID_BIN, 0666, 1119 "fd/%d", fd); 1120 devfs_token_stdin = 1121 devfs_add_devswf(&fildesc_cdevsw, 0, DV_CHR, 1122 UID_ROOT, GID_WHEEL, 0666, 1123 "stdin", fd); 1124 devfs_token_stdout = 1125 devfs_add_devswf(&fildesc_cdevsw, 1, DV_CHR, 1126 UID_ROOT, GID_WHEEL, 0666, 1127 "stdout", fd); 1128 devfs_token_stderr = 1129 devfs_add_devswf(&fildesc_cdevsw, 2, DV_CHR, 1130 UID_ROOT, GID_WHEEL, 0666, 1131 "stderr", fd); 1132 #endif 1133 } 1134 } 1135 1136 SYSINIT(fildescdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR, 1137 fildesc_drvinit,NULL) 1138 1139 1140