mirror of
https://https.git.savannah.gnu.org/git/bash.git
synced 2026-06-21 12:57:58 +02:00
Chet Ramey
121 lines
2.5 KiB
C
121 lines
2.5 KiB
C
/* anonfile.c - open and close temporary files (anonymous and memory-backed if possible). */
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/* Copyright (C) 2023-2024 Free Software Foundation, Inc.
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This file is part of GNU Bash, the Bourne Again SHell.
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Bash is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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Bash is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with Bash. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <config.h>
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#if defined (HAVE_UNISTD_H)
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# include <unistd.h>
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#endif
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#include <bashtypes.h>
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#if defined (HAVE_MEMFD_CREATE) || defined (HAVE_SHM_MKSTEMP)
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# include <sys/mman.h>
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#endif
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#include <filecntl.h>
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#include <errno.h>
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#include <shell.h>
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#include <bashansi.h>
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static int anonunlink (const char *);
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#if defined (HAVE_MEMFD_CREATE) && !defined (MFD_NOEXEC_SEAL)
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# define MFD_NOEXEC_SEAL 0
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#endif
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#if defined (HAVE_SHM_MKSTEMP)
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static int
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anonshmopen (const char *name, int flags, char **fn)
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{
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int fd;
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char *fname;
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fd = -1;
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if (fn)
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*fn = 0;
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fname = savestring ("/shm-XXXXXXXXXX");
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fd = shm_mkstemp (fname);
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if (fd < 0)
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{
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free (fname);
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return fd;
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}
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if (fn)
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*fn = fname;
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else
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free (fname);
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return fd;
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}
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#endif
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int
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anonopen (const char *name, int flags, char **fn)
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{
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int fd, flag;
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char *fname;
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#if defined (HAVE_MEMFD_CREATE)
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/* "Names do not affect the behavior of the file descriptor." */
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fd = memfd_create ("anonopen", MFD_NOEXEC_SEAL);
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if (fd >= 0)
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{
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if (fn)
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*fn = 0;
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return fd;
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}
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/* If memfd_create fails, we fall through to the unlinked-shm-or-regular-file
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implementation. */
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#endif
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/* Heuristic */
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flag = (name && *name == '/') ? MT_TEMPLATE : MT_USETMPDIR;
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#if defined (HAVE_SHM_MKSTEMP)
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fd = anonshmopen (name, flag, fn);
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if (fd >= 0)
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return fd; /* anonshmopen sets *FN appropriately */
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#endif
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fd = sh_mktmpfd (name, flag|MT_USERANDOM|MT_READWRITE|MT_UNLINK, fn);
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return fd;
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}
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int
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anonclose (int fd, const char *name)
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{
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int r;
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r = close (fd);
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return r;
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}
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static int
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anonunlink (const char *fn)
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{
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int r;
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r = unlink (fn);
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return r;
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}
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