redir.c revision 1.68
1 /* $NetBSD: redir.c,v 1.68 2021/09/15 18:29:45 kre Exp $ */ 2 3 /*- 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Kenneth Almquist. 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. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 #ifndef lint 37 #if 0 38 static char sccsid[] = "@(#)redir.c 8.2 (Berkeley) 5/4/95"; 39 #else 40 __RCSID("$NetBSD: redir.c,v 1.68 2021/09/15 18:29:45 kre Exp $"); 41 #endif 42 #endif /* not lint */ 43 44 #include <sys/types.h> 45 #include <sys/param.h> /* PIPE_BUF */ 46 #include <sys/stat.h> 47 #include <signal.h> 48 #include <string.h> 49 #include <fcntl.h> 50 #include <errno.h> 51 #include <unistd.h> 52 #include <stdlib.h> 53 54 /* 55 * Code for dealing with input/output redirection. 56 */ 57 58 #include "main.h" 59 #include "builtins.h" 60 #include "shell.h" 61 #include "nodes.h" 62 #include "jobs.h" 63 #include "options.h" 64 #include "expand.h" 65 #include "redir.h" 66 #include "output.h" 67 #include "memalloc.h" 68 #include "mystring.h" 69 #include "error.h" 70 #include "show.h" 71 72 73 #define EMPTY -2 /* marks an unused slot in redirtab */ 74 #define CLOSED -1 /* fd was not open before redir */ 75 #ifndef PIPE_BUF 76 # define PIPESIZE 4096 /* amount of buffering in a pipe */ 77 #else 78 # define PIPESIZE PIPE_BUF 79 #endif 80 81 #ifndef FD_CLOEXEC 82 # define FD_CLOEXEC 1 /* well known from before there was a name */ 83 #endif 84 85 #ifndef F_DUPFD_CLOEXEC 86 #define F_DUPFD_CLOEXEC F_DUPFD 87 #define CLOEXEC(fd) (fcntl((fd), F_SETFD, fcntl((fd),F_GETFD) | FD_CLOEXEC)) 88 #else 89 #define CLOEXEC(fd) 90 #endif 91 92 93 MKINIT 94 struct renamelist { 95 struct renamelist *next; 96 int orig; 97 int into; 98 }; 99 100 MKINIT 101 struct redirtab { 102 struct redirtab *next; 103 struct renamelist *renamed; 104 }; 105 106 107 MKINIT struct redirtab *redirlist; 108 109 /* 110 * We keep track of whether or not fd0 has been redirected. This is for 111 * background commands, where we want to redirect fd0 to /dev/null only 112 * if it hasn't already been redirected. 113 */ 114 STATIC int fd0_redirected = 0; 115 116 /* 117 * And also where to put internal use fds that should be out of the 118 * way of user defined fds (normally) 119 */ 120 STATIC int big_sh_fd = 0; 121 122 STATIC const struct renamelist *is_renamed(const struct renamelist *, int); 123 STATIC void fd_rename(struct redirtab *, int, int); 124 STATIC int * saved_redirected_fd(int); 125 STATIC void free_rl(struct redirtab *, int); 126 STATIC void openredirect(union node *, char[10], int); 127 STATIC int openhere(const union node *); 128 STATIC int copyfd(int, int, int); 129 STATIC void find_big_fd(void); 130 131 132 struct shell_fds { /* keep track of internal shell fds */ 133 struct shell_fds *nxt; 134 void (*cb)(int, int); 135 int fd; 136 }; 137 138 STATIC struct shell_fds *sh_fd_list; 139 140 STATIC int pick_new_fd(int); 141 STATIC void renumber_sh_fd(struct shell_fds *); 142 STATIC struct shell_fds *sh_fd(int); 143 144 STATIC const struct renamelist * 145 is_renamed(const struct renamelist *rl, int fd) 146 { 147 while (rl != NULL) { 148 if (rl->orig == fd) 149 return rl; 150 rl = rl->next; 151 } 152 return NULL; 153 } 154 155 STATIC int * 156 saved_redirected_fd(int fd) 157 { 158 struct redirtab *rt; 159 struct renamelist *rl; 160 161 for (rt = redirlist; rt != NULL; rt = rt->next) { 162 for (rl = rt->renamed; rl != NULL; rl = rl->next) { 163 if (rl->into == fd) 164 return &rl->into; 165 } 166 } 167 return NULL; 168 } 169 170 STATIC void 171 free_rl(struct redirtab *rt, int reset) 172 { 173 struct renamelist *rl, *rn = rt->renamed; 174 175 while ((rl = rn) != NULL) { 176 rn = rl->next; 177 if (rl->orig == 0) 178 fd0_redirected--; 179 VTRACE(DBG_REDIR, ("popredir %d%s: %s", 180 rl->orig, rl->orig==0 ? " (STDIN)" : "", 181 reset ? "" : "no reset\n")); 182 if (reset) { 183 if (rl->into < 0) { 184 VTRACE(DBG_REDIR, ("closed\n")); 185 close(rl->orig); 186 } else { 187 VTRACE(DBG_REDIR, ("from %d\n", rl->into)); 188 movefd(rl->into, rl->orig); 189 } 190 } 191 ckfree(rl); 192 } 193 rt->renamed = NULL; 194 } 195 196 STATIC void 197 fd_rename(struct redirtab *rt, int from, int to) 198 { 199 /* XXX someday keep a short list (8..10) of freed renamelists XXX */ 200 struct renamelist *rl = ckmalloc(sizeof(struct renamelist)); 201 202 rl->next = rt->renamed; 203 rt->renamed = rl; 204 205 rl->orig = from; 206 rl->into = to; 207 } 208 209 /* 210 * Process a list of redirection commands. If the REDIR_PUSH flag is set, 211 * old file descriptors are stashed away so that the redirection can be 212 * undone by calling popredir. If the REDIR_BACKQ flag is set, then the 213 * standard output, and the standard error if it becomes a duplicate of 214 * stdout, is saved in memory. 215 */ 216 217 void 218 redirect(union node *redir, int flags) 219 { 220 union node *n; 221 struct redirtab *sv = NULL; 222 int i; 223 int fd; 224 char memory[10]; /* file descriptors to write to memory */ 225 226 CTRACE(DBG_REDIR, ("redirect(F=0x%x):%s\n", flags, redir?"":" NONE")); 227 for (i = 10 ; --i >= 0 ; ) 228 memory[i] = 0; 229 memory[1] = flags & REDIR_BACKQ; 230 if (flags & REDIR_PUSH) { 231 /* 232 * We don't have to worry about REDIR_VFORK here, as 233 * flags & REDIR_PUSH is never true if REDIR_VFORK is set. 234 */ 235 sv = ckmalloc(sizeof (struct redirtab)); 236 sv->renamed = NULL; 237 sv->next = redirlist; 238 redirlist = sv; 239 } 240 for (n = redir ; n ; n = n->nfile.next) { 241 int *renamed; 242 243 fd = n->nfile.fd; 244 VTRACE(DBG_REDIR, ("redir %d (max=%d limit=%ld) ", 245 fd, max_user_fd, user_fd_limit)); 246 if (fd < user_fd_limit && fd > max_user_fd) 247 max_user_fd = fd; 248 if ((renamed = saved_redirected_fd(fd)) != NULL) { 249 int to = pick_new_fd(fd); 250 251 VTRACE(DBG_REDIR, 252 ("redirect: moved holding fd %d to %d\n", fd, to)); 253 *renamed = to; 254 if (to != fd) /* always... */ 255 (void)close(fd); 256 } 257 renumber_sh_fd(sh_fd(fd)); 258 if ((n->nfile.type == NTOFD || n->nfile.type == NFROMFD) && 259 n->ndup.dupfd == fd) { 260 /* redirect from/to same file descriptor */ 261 /* make sure it stays open */ 262 if (fcntl(fd, F_SETFD, 0) < 0) 263 error("fd %d: %s", fd, strerror(errno)); 264 VTRACE(DBG_REDIR, ("!cloexec\n")); 265 continue; 266 } 267 268 if ((flags & REDIR_PUSH) && !is_renamed(sv->renamed, fd)) { 269 int bigfd; 270 271 INTOFF; 272 if (big_sh_fd < 10) 273 find_big_fd(); 274 if ((bigfd = big_sh_fd) < max_user_fd) 275 bigfd = max_user_fd; 276 if ((i = fcntl(fd, F_DUPFD, bigfd + 1)) == -1) { 277 switch (errno) { 278 case EBADF: 279 i = CLOSED; 280 break; 281 case EMFILE: 282 case EINVAL: 283 find_big_fd(); 284 i = fcntl(fd, F_DUPFD, big_sh_fd); 285 if (i >= 0) 286 break; 287 if (errno == EMFILE || errno == EINVAL) 288 i = fcntl(fd, F_DUPFD, 3); 289 if (i >= 0) 290 break; 291 /* FALLTHRU */ 292 default: 293 error("%d: %s", fd, strerror(errno)); 294 /* NOTREACHED */ 295 } 296 } 297 if (i >= 0) 298 (void)fcntl(i, F_SETFD, FD_CLOEXEC); 299 fd_rename(sv, fd, i); 300 VTRACE(DBG_REDIR, ("fd %d saved as %d ", fd, i)); 301 INTON; 302 } 303 VTRACE(DBG_REDIR, ("%s\n", fd == 0 ? "STDIN" : "")); 304 if (fd == 0) 305 fd0_redirected++; 306 openredirect(n, memory, flags); 307 } 308 if (memory[1]) 309 out1 = &memout; 310 if (memory[2]) 311 out2 = &memout; 312 } 313 314 315 STATIC void 316 openredirect(union node *redir, char memory[10], int flags) 317 { 318 struct stat sb; 319 int fd = redir->nfile.fd; 320 char *fname; 321 int f; 322 int eflags, cloexec; 323 324 /* 325 * We suppress interrupts so that we won't leave open file 326 * descriptors around. This may not be such a good idea because 327 * an open of a device or a fifo can block indefinitely. 328 */ 329 INTOFF; 330 if (fd < 10) 331 memory[fd] = 0; 332 switch (redir->nfile.type) { 333 case NFROM: 334 fname = redir->nfile.expfname; 335 if (flags & REDIR_VFORK) 336 eflags = O_NONBLOCK; 337 else 338 eflags = 0; 339 if ((f = open(fname, O_RDONLY|eflags)) < 0) 340 goto eopen; 341 VTRACE(DBG_REDIR, ("openredirect(< '%s') -> %d [%#x]", 342 fname, f, eflags)); 343 if (eflags) 344 (void)fcntl(f, F_SETFL, fcntl(f, F_GETFL, 0) & ~eflags); 345 break; 346 case NFROMTO: 347 fname = redir->nfile.expfname; 348 if ((f = open(fname, O_RDWR|O_CREAT, 0666)) < 0) 349 goto ecreate; 350 VTRACE(DBG_REDIR, ("openredirect(<> '%s') -> %d", fname, f)); 351 break; 352 case NTO: 353 if (Cflag) { 354 fname = redir->nfile.expfname; 355 if ((f = open(fname, O_WRONLY)) == -1) { 356 if ((f = open(fname, O_WRONLY|O_CREAT|O_EXCL, 357 0666)) < 0) 358 goto ecreate; 359 } else if (fstat(f, &sb) == -1) { 360 int serrno = errno; 361 close(f); 362 errno = serrno; 363 goto ecreate; 364 } else if (S_ISREG(sb.st_mode)) { 365 close(f); 366 errno = EEXIST; 367 goto ecreate; 368 } 369 VTRACE(DBG_REDIR, ("openredirect(>| '%s') -> %d", 370 fname, f)); 371 break; 372 } 373 /* FALLTHROUGH */ 374 case NCLOBBER: 375 fname = redir->nfile.expfname; 376 if ((f = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666)) < 0) 377 goto ecreate; 378 VTRACE(DBG_REDIR, ("openredirect(> '%s') -> %d", fname, f)); 379 break; 380 case NAPPEND: 381 fname = redir->nfile.expfname; 382 if ((f = open(fname, O_WRONLY|O_CREAT|O_APPEND, 0666)) < 0) 383 goto ecreate; 384 VTRACE(DBG_REDIR, ("openredirect(>> '%s') -> %d", fname, f)); 385 break; 386 case NTOFD: 387 case NFROMFD: 388 if (redir->ndup.dupfd >= 0) { /* if not ">&-" */ 389 if (sh_fd(redir->ndup.dupfd) != NULL || 390 saved_redirected_fd(redir->ndup.dupfd) != NULL) 391 error("Redirect (from %d to %d) failed: %s", 392 redir->ndup.dupfd, fd, strerror(EBADF)); 393 if (fd < 10 && redir->ndup.dupfd < 10 && 394 memory[redir->ndup.dupfd]) 395 memory[fd] = 1; 396 else if (copyfd(redir->ndup.dupfd, fd, 397 (flags & REDIR_KEEP) == 0) < 0) 398 error("Redirect (from %d to %d) failed: %s", 399 redir->ndup.dupfd, fd, strerror(errno)); 400 VTRACE(DBG_REDIR, ("openredirect: %d%c&%d\n", fd, 401 "<>"[redir->nfile.type==NTOFD], redir->ndup.dupfd)); 402 } else { 403 (void) close(fd); 404 VTRACE(DBG_REDIR, ("openredirect: %d%c&-\n", fd, 405 "<>"[redir->nfile.type==NTOFD])); 406 } 407 INTON; 408 return; 409 case NHERE: 410 case NXHERE: 411 VTRACE(DBG_REDIR, ("openredirect: %d<<...", fd)); 412 f = openhere(redir); 413 break; 414 default: 415 abort(); 416 } 417 418 cloexec = fd > 2 && (flags & REDIR_KEEP) == 0 && !posix; 419 if (f != fd) { 420 VTRACE(DBG_REDIR, (" -> %d", fd)); 421 if (copyfd(f, fd, cloexec) < 0) { 422 int e = errno; 423 424 close(f); 425 error("redirect reassignment (fd %d) failed: %s", fd, 426 strerror(e)); 427 } 428 close(f); 429 } else if (cloexec) 430 (void)fcntl(f, F_SETFD, FD_CLOEXEC); 431 VTRACE(DBG_REDIR, ("%s\n", cloexec ? " cloexec" : "")); 432 433 INTON; 434 return; 435 ecreate: 436 exerrno = 1; 437 error("cannot create %s: %s", fname, errmsg(errno, E_CREAT)); 438 eopen: 439 exerrno = 1; 440 error("cannot open %s: %s", fname, errmsg(errno, E_OPEN)); 441 } 442 443 444 /* 445 * Handle here documents. Normally we fork off a process to write the 446 * data to a pipe. If the document is short, we can stuff the data in 447 * the pipe without forking. 448 */ 449 450 STATIC int 451 openhere(const union node *redir) 452 { 453 int pip[2]; 454 int len = 0; 455 456 if (pipe(pip) < 0) 457 error("Pipe call failed"); 458 if (redir->type == NHERE) { 459 len = strlen(redir->nhere.doc->narg.text); 460 if (len <= PIPESIZE) { 461 xwrite(pip[1], redir->nhere.doc->narg.text, len); 462 goto out; 463 } 464 } 465 VTRACE(DBG_REDIR, (" forking [%d,%d]\n", pip[0], pip[1])); 466 if (forkshell(NULL, NULL, FORK_NOJOB) == 0) { 467 close(pip[0]); 468 signal(SIGINT, SIG_IGN); 469 signal(SIGQUIT, SIG_IGN); 470 signal(SIGHUP, SIG_IGN); 471 #ifdef SIGTSTP 472 signal(SIGTSTP, SIG_IGN); 473 #endif 474 signal(SIGPIPE, SIG_DFL); 475 if (redir->type == NHERE) 476 xwrite(pip[1], redir->nhere.doc->narg.text, len); 477 else 478 expandhere(redir->nhere.doc, pip[1]); 479 VTRACE(DBG_PROCS|DBG_REDIR, ("wrote here doc. exiting\n")); 480 _exit(0); 481 } 482 VTRACE(DBG_REDIR, ("openhere (closing %d)", pip[1])); 483 out: 484 close(pip[1]); 485 VTRACE(DBG_REDIR, (" (pipe fd=%d)", pip[0])); 486 return pip[0]; 487 } 488 489 490 491 /* 492 * Undo the effects of the last redirection. 493 */ 494 495 void 496 popredir(void) 497 { 498 struct redirtab *rp = redirlist; 499 500 INTOFF; 501 free_rl(rp, 1); 502 redirlist = rp->next; 503 ckfree(rp); 504 INTON; 505 } 506 507 /* 508 * Undo all redirections. Called on error or interrupt. 509 */ 510 511 #ifdef mkinit 512 513 INCLUDE "redir.h" 514 515 RESET { 516 while (redirlist) 517 popredir(); 518 } 519 520 SHELLPROC { 521 clearredir(0); 522 } 523 524 #endif 525 526 /* Return true if fd 0 has already been redirected at least once. */ 527 int 528 fd0_redirected_p(void) 529 { 530 return fd0_redirected != 0; 531 } 532 533 /* 534 * Discard all saved file descriptors. 535 */ 536 537 void 538 clearredir(int vforked) 539 { 540 struct redirtab *rp; 541 struct renamelist *rl; 542 543 for (rp = redirlist ; rp ; rp = rp->next) { 544 if (!vforked) 545 free_rl(rp, 0); 546 else for (rl = rp->renamed; rl; rl = rl->next) 547 if (rl->into >= 0) 548 close(rl->into); 549 } 550 } 551 552 553 554 /* 555 * Copy a file descriptor to be == to. 556 * cloexec indicates if we want close-on-exec or not. 557 * Returns -1 if any error occurs. 558 */ 559 560 STATIC int 561 copyfd(int from, int to, int cloexec) 562 { 563 int newfd; 564 565 if (cloexec && to > 2) { 566 #ifdef O_CLOEXEC 567 newfd = dup3(from, to, O_CLOEXEC); 568 #else 569 newfd = dup2(from, to); 570 fcntl(newfd, F_SETFD, fcntl(newfd,F_GETFD) | FD_CLOEXEC); 571 #endif 572 } else 573 newfd = dup2(from, to); 574 575 return newfd; 576 } 577 578 /* 579 * rename fd from to be fd to (closing from). 580 * close-on-exec is never set on 'to' (unless 581 * from==to and it was set on from) - ie: a no-op 582 * returns to (or errors() if an error occurs). 583 * 584 * This is mostly used for rearranging the 585 * results from pipe(). 586 */ 587 int 588 movefd(int from, int to) 589 { 590 if (from == to) 591 return to; 592 593 (void) close(to); 594 if (copyfd(from, to, 0) != to) { 595 int e = errno; 596 597 (void) close(from); 598 error("Unable to make fd %d: %s", to, strerror(e)); 599 } 600 (void) close(from); 601 602 return to; 603 } 604 605 STATIC void 606 find_big_fd(void) 607 { 608 int i, fd; 609 static int last_start = 3; /* aim to keep sh fd's under 20 */ 610 611 if (last_start < 10) 612 last_start++; 613 614 for (i = (1 << last_start); i >= 10; i >>= 1) { 615 if ((fd = fcntl(0, F_DUPFD, i - 1)) >= 0) { 616 close(fd); 617 break; 618 } 619 } 620 621 fd = (i / 5) * 4; 622 if (fd < 10) 623 fd = 10; 624 625 big_sh_fd = fd; 626 } 627 628 /* 629 * If possible, move file descriptor fd out of the way 630 * of expected user fd values. Returns the new fd 631 * (which may be the input fd if things do not go well.) 632 * Always set close-on-exec on the result, and close 633 * the input fd unless it is to be our result. 634 */ 635 int 636 to_upper_fd(int fd) 637 { 638 int i; 639 640 VTRACE(DBG_REDIR|DBG_OUTPUT, ("to_upper_fd(%d)", fd)); 641 if (big_sh_fd < 10 || big_sh_fd >= user_fd_limit) 642 find_big_fd(); 643 do { 644 i = fcntl(fd, F_DUPFD_CLOEXEC, big_sh_fd); 645 if (i >= 0) { 646 if (fd != i) 647 close(fd); 648 VTRACE(DBG_REDIR|DBG_OUTPUT, ("-> %d\n", i)); 649 return i; 650 } 651 if (errno != EMFILE && errno != EINVAL) 652 break; 653 find_big_fd(); 654 } while (big_sh_fd > 10); 655 656 /* 657 * If we wanted to move this fd to some random high number 658 * we certainly do not intend to pass it through exec, even 659 * if the reassignment failed. 660 */ 661 (void)fcntl(fd, F_SETFD, FD_CLOEXEC); 662 VTRACE(DBG_REDIR|DBG_OUTPUT, (" fails ->%d\n", fd)); 663 return fd; 664 } 665 666 void 667 register_sh_fd(int fd, void (*cb)(int, int)) 668 { 669 struct shell_fds *fp; 670 671 fp = ckmalloc(sizeof (struct shell_fds)); 672 if (fp != NULL) { 673 fp->nxt = sh_fd_list; 674 sh_fd_list = fp; 675 676 fp->fd = fd; 677 fp->cb = cb; 678 } 679 } 680 681 void 682 sh_close(int fd) 683 { 684 struct shell_fds **fpp, *fp; 685 686 fpp = &sh_fd_list; 687 while ((fp = *fpp) != NULL) { 688 if (fp->fd == fd) { 689 *fpp = fp->nxt; 690 ckfree(fp); 691 break; 692 } 693 fpp = &fp->nxt; 694 } 695 (void)close(fd); 696 } 697 698 STATIC struct shell_fds * 699 sh_fd(int fd) 700 { 701 struct shell_fds *fp; 702 703 for (fp = sh_fd_list; fp != NULL; fp = fp->nxt) 704 if (fp->fd == fd) 705 return fp; 706 return NULL; 707 } 708 709 STATIC int 710 pick_new_fd(int fd) 711 { 712 int to; 713 714 to = fcntl(fd, F_DUPFD_CLOEXEC, big_sh_fd); 715 if (to == -1 && big_sh_fd >= 22) 716 to = fcntl(fd, F_DUPFD_CLOEXEC, big_sh_fd/2); 717 if (to == -1) 718 to = fcntl(fd, F_DUPFD_CLOEXEC, fd + 1); 719 if (to == -1) 720 to = fcntl(fd, F_DUPFD_CLOEXEC, 10); 721 if (to == -1) 722 to = fcntl(fd, F_DUPFD_CLOEXEC, 3); 723 if (to == -1) 724 error("insufficient file descriptors available"); 725 CLOEXEC(to); 726 return to; 727 } 728 729 STATIC void 730 renumber_sh_fd(struct shell_fds *fp) 731 { 732 int to; 733 734 if (fp == NULL) 735 return; 736 737 /* 738 * if we have had a collision, and the sh fd was a "big" one 739 * try moving the sh fd base to a higher number (if possible) 740 * so future sh fds are less likely to be in the user's sights 741 * (incl this one when moved) 742 */ 743 if (fp->fd >= big_sh_fd) 744 find_big_fd(); 745 746 to = pick_new_fd(fp->fd); 747 748 if (fp->fd == to) /* impossible? */ 749 return; 750 751 VTRACE(DBG_REDIR, ("renumber_sh_fd: moved shell fd %d to %d\n", 752 fp->fd, to)); 753 754 (*fp->cb)(fp->fd, to); 755 (void)close(fp->fd); 756 fp->fd = to; 757 } 758 759 static const struct flgnames { 760 const char *name; 761 uint16_t minch; 762 uint32_t value; 763 } nv[] = { 764 #ifdef O_APPEND 765 { "append", 2, O_APPEND }, 766 #else 767 # define O_APPEND 0 768 #endif 769 #ifdef O_ASYNC 770 { "async", 2, O_ASYNC }, 771 #else 772 # define O_ASYNC 0 773 #endif 774 #ifdef O_SYNC 775 { "sync", 2, O_SYNC }, 776 #else 777 # define O_SYNC 0 778 #endif 779 #ifdef O_NONBLOCK 780 { "nonblock", 3, O_NONBLOCK }, 781 #else 782 # define O_NONBLOCK 0 783 #endif 784 #ifdef O_FSYNC 785 { "fsync", 2, O_FSYNC }, 786 #else 787 # define O_FSYNC 0 788 #endif 789 #ifdef O_DSYNC 790 { "dsync", 2, O_DSYNC }, 791 #else 792 # define O_DSYNC 0 793 #endif 794 #ifdef O_RSYNC 795 { "rsync", 2, O_RSYNC }, 796 #else 797 # define O_RSYNC 0 798 #endif 799 #ifdef O_ALT_IO 800 { "altio", 2, O_ALT_IO }, 801 #else 802 # define O_ALT_IO 0 803 #endif 804 #ifdef O_DIRECT 805 { "direct", 2, O_DIRECT }, 806 #else 807 # define O_DIRECT 0 808 #endif 809 #ifdef O_NOSIGPIPE 810 { "nosigpipe", 3, O_NOSIGPIPE }, 811 #else 812 # define O_NOSIGPIPE 0 813 #endif 814 815 #define ALLFLAGS (O_APPEND|O_ASYNC|O_SYNC|O_NONBLOCK|O_DSYNC|O_RSYNC|\ 816 O_ALT_IO|O_DIRECT|O_NOSIGPIPE) 817 818 #ifndef O_CLOEXEC 819 # define O_CLOEXEC ((~ALLFLAGS) ^ ((~ALLFLAGS) & ((~ALLFLAGS) - 1))) 820 #endif 821 822 /* for any system we support, close on exec is always defined */ 823 { "cloexec", 2, O_CLOEXEC }, 824 { 0, 0, 0 } 825 }; 826 827 #ifndef O_ACCMODE 828 # define O_ACCMODE 0 829 #endif 830 #ifndef O_RDONLY 831 # define O_RDONLY 0 832 #endif 833 #ifndef O_WRONLY 834 # define O_WRONLY 0 835 #endif 836 #ifndef O_RWDR 837 # define O_RWDR 0 838 #endif 839 #ifndef O_SHLOCK 840 # define O_SHLOCK 0 841 #endif 842 #ifndef O_EXLOCK 843 # define O_EXLOCK 0 844 #endif 845 #ifndef O_NOFOLLOW 846 # define O_NOFOLLOW 0 847 #endif 848 #ifndef O_CREAT 849 # define O_CREAT 0 850 #endif 851 #ifndef O_TRUNC 852 # define O_TRUNC 0 853 #endif 854 #ifndef O_EXCL 855 # define O_EXCL 0 856 #endif 857 #ifndef O_NOCTTY 858 # define O_NOCTTY 0 859 #endif 860 #ifndef O_DIRECTORY 861 # define O_DIRECTORY 0 862 #endif 863 #ifndef O_REGULAR 864 # define O_REGULAR 0 865 #endif 866 /* 867 * flags that F_GETFL might return that we want to ignore 868 * 869 * F_GETFL should not actually return these, they're all just open() 870 * modifiers, rather than state, but just in case... 871 */ 872 #define IGNFLAGS (O_ACCMODE|O_RDONLY|O_WRONLY|O_RDWR|O_SHLOCK|O_EXLOCK| \ 873 O_NOFOLLOW|O_CREAT|O_TRUNC|O_EXCL|O_NOCTTY|O_DIRECTORY|O_REGULAR) 874 875 static int 876 getflags(int fd, int p) 877 { 878 int c, f; 879 880 if (sh_fd(fd) != NULL || saved_redirected_fd(fd) != NULL) { 881 if (!p) 882 return -1; 883 error("Can't get status for fd=%d (%s)", fd, strerror(EBADF)); 884 } 885 886 if ((c = fcntl(fd, F_GETFD)) == -1) { 887 if (!p) 888 return -1; 889 error("Can't get status for fd=%d (%s)", fd, strerror(errno)); 890 } 891 if ((f = fcntl(fd, F_GETFL)) == -1) { 892 if (!p) 893 return -1; 894 error("Can't get flags for fd=%d (%s)", fd, strerror(errno)); 895 } 896 f &= ~IGNFLAGS; /* clear anything we know about, but ignore */ 897 if (c & FD_CLOEXEC) 898 f |= O_CLOEXEC; 899 return f; 900 } 901 902 static void 903 printone(int fd, int p, int verbose, int pfd) 904 { 905 int f = getflags(fd, p); 906 const struct flgnames *fn; 907 908 if (f == -1) 909 return; 910 911 if (pfd) 912 outfmt(out1, "%d: ", fd); 913 for (fn = nv; fn->name; fn++) { 914 if (f & fn->value) { 915 outfmt(out1, "%s%s", verbose ? "+" : "", fn->name); 916 f &= ~fn->value; 917 } else if (verbose) 918 outfmt(out1, "-%s", fn->name); 919 else 920 continue; 921 if (f || (verbose && fn[1].name)) 922 outfmt(out1, ","); 923 } 924 if (verbose && f) /* f should be normally be 0 */ 925 outfmt(out1, " +%#x", f); 926 outfmt(out1, "\n"); 927 } 928 929 static void 930 parseflags(char *s, int *p, int *n) 931 { 932 int *v, *w; 933 const struct flgnames *fn; 934 size_t len; 935 936 *p = 0; 937 *n = 0; 938 for (s = strtok(s, ","); s; s = strtok(NULL, ",")) { 939 switch (*s++) { 940 case '+': 941 v = p; 942 w = n; 943 break; 944 case '-': 945 v = n; 946 w = p; 947 break; 948 default: 949 error("Missing +/- indicator before flag %s", s-1); 950 } 951 952 len = strlen(s); 953 for (fn = nv; fn->name; fn++) 954 if (len >= fn->minch && strncmp(s,fn->name,len) == 0) { 955 *v |= fn->value; 956 *w &=~ fn->value; 957 break; 958 } 959 if (fn->name == 0) 960 error("Bad flag `%s'", s); 961 } 962 } 963 964 static void 965 setone(int fd, int pos, int neg, int verbose) 966 { 967 int f = getflags(fd, 1); 968 int n, cloexec; 969 970 if (f == -1) 971 return; 972 973 cloexec = -1; 974 if ((pos & O_CLOEXEC) && !(f & O_CLOEXEC)) 975 cloexec = FD_CLOEXEC; 976 if ((neg & O_CLOEXEC) && (f & O_CLOEXEC)) 977 cloexec = 0; 978 979 if (cloexec != -1 && fcntl(fd, F_SETFD, cloexec) == -1) 980 error("Can't set status for fd=%d (%s)", fd, strerror(errno)); 981 982 pos &= ~O_CLOEXEC; 983 neg &= ~O_CLOEXEC; 984 f &= ~O_CLOEXEC; 985 n = f; 986 n |= pos; 987 n &= ~neg; 988 if (n != f && fcntl(fd, F_SETFL, n) == -1) 989 error("Can't set flags for fd=%d (%s)", fd, strerror(errno)); 990 if (verbose) 991 printone(fd, 1, verbose, 1); 992 } 993 994 int 995 fdflagscmd(int argc, char *argv[]) 996 { 997 char *num; 998 int verbose = 0, ch, pos = 0, neg = 0; 999 char *setflags = NULL; 1000 1001 optreset = 1; optind = 1; /* initialize getopt */ 1002 while ((ch = getopt(argc, argv, ":vs:")) != -1) 1003 switch ((char)ch) { 1004 case 'v': 1005 verbose = 1; 1006 break; 1007 case 's': 1008 if (setflags) 1009 goto msg; 1010 setflags = optarg; 1011 break; 1012 case '?': 1013 default: 1014 msg: 1015 error("Usage: fdflags [-v] [-s <flags> fd] [fd...]"); 1016 /* NOTREACHED */ 1017 } 1018 1019 argc -= optind, argv += optind; 1020 1021 if (setflags) 1022 parseflags(setflags, &pos, &neg); 1023 1024 if (argc == 0) { 1025 int i; 1026 1027 if (setflags) 1028 goto msg; 1029 1030 for (i = 0; i <= max_user_fd; i++) 1031 printone(i, 0, verbose, 1); 1032 return 0; 1033 } 1034 1035 while ((num = *argv++) != NULL) { 1036 int fd = number(num); 1037 1038 while (num[0] == '0' && num[1] != '\0') /* skip 0's */ 1039 num++; 1040 if (strlen(num) > 5 || 1041 (fd >= user_fd_limit && fd > max_user_fd)) 1042 error("%s: too big to be a file descriptor", num); 1043 1044 if (setflags) 1045 setone(fd, pos, neg, verbose); 1046 else 1047 printone(fd, 1, verbose, argc > 1); 1048 } 1049 return 0; 1050 } 1051 1052 #undef MAX /* in case we inherited them from somewhere */ 1053 #undef MIN 1054 1055 #define MIN(a,b) (/*CONSTCOND*/((a)<=(b)) ? (a) : (b)) 1056 #define MAX(a,b) (/*CONSTCOND*/((a)>=(b)) ? (a) : (b)) 1057 1058 /* now make the compiler work for us... */ 1059 #define MIN_REDIR MIN(MIN(MIN(MIN(NTO,NFROM), MIN(NTOFD,NFROMFD)), \ 1060 MIN(MIN(NCLOBBER,NAPPEND), MIN(NHERE,NXHERE))), NFROMTO) 1061 #define MAX_REDIR MAX(MAX(MAX(MAX(NTO,NFROM), MAX(NTOFD,NFROMFD)), \ 1062 MAX(MAX(NCLOBBER,NAPPEND), MAX(NHERE,NXHERE))), NFROMTO) 1063 1064 static const char *redir_sym[MAX_REDIR - MIN_REDIR + 1] = { 1065 [NTO - MIN_REDIR]= ">", 1066 [NFROM - MIN_REDIR]= "<", 1067 [NTOFD - MIN_REDIR]= ">&", 1068 [NFROMFD - MIN_REDIR]= "<&", 1069 [NCLOBBER - MIN_REDIR]= ">|", 1070 [NAPPEND - MIN_REDIR]= ">>", 1071 [NHERE - MIN_REDIR]= "<<", 1072 [NXHERE - MIN_REDIR]= "<<", 1073 [NFROMTO - MIN_REDIR]= "<>", 1074 }; 1075 1076 int 1077 outredir(struct output *out, union node *n, int sep) 1078 { 1079 if (n == NULL) 1080 return 0; 1081 if (n->type < MIN_REDIR || n->type > MAX_REDIR || 1082 redir_sym[n->type - MIN_REDIR] == NULL) 1083 return 0; 1084 1085 if (sep) 1086 outc(sep, out); 1087 1088 /* 1089 * ugly, but all redir node types have "fd" in same slot... 1090 * (and code other places assumes it as well) 1091 */ 1092 if ((redir_sym[n->type - MIN_REDIR][0] == '<' && n->nfile.fd != 0) || 1093 (redir_sym[n->type - MIN_REDIR][0] == '>' && n->nfile.fd != 1)) 1094 outfmt(out, "%d", n->nfile.fd); 1095 1096 outstr(redir_sym[n->type - MIN_REDIR], out); 1097 1098 switch (n->type) { 1099 case NHERE: 1100 outstr("'...'", out); 1101 break; 1102 case NXHERE: 1103 outstr("...", out); 1104 break; 1105 case NTOFD: 1106 case NFROMFD: 1107 if (n->ndup.dupfd < 0) 1108 outc('-', out); 1109 else 1110 outfmt(out, "%d", n->ndup.dupfd); 1111 break; 1112 default: 1113 outstr(n->nfile.expfname, out); 1114 break; 1115 } 1116 return 1; 1117 } 1118
Indexes created Fri Sep 26 20:09:58 GMT 2025