260ba0bff1
Mainly focus on files that use BSD 2-Clause license, however the tool I was using mis-identified many licenses so this was mostly a manual - error prone - task. The Software Package Data Exchange (SPDX) group provides a specification to make it easier for automated tools to detect and summarize well known opensource licenses. We are gradually adopting the specification, noting that the tags are considered only advisory and do not, in any way, superceed or replace the license texts.
148 lines
3.7 KiB
C
148 lines
3.7 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright (c) 2007-2009 Dag-Erling Coïdan Smørgrav
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer
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* in this position and unchanged.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/file.h>
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#include <sys/stat.h>
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#include <errno.h>
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#include <stdarg.h>
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#include <unistd.h>
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#include <libutil.h>
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/*
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* Reliably open and lock a file.
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*
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* Please do not modify this code without first reading the revision history
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* and discussing your changes with <des@freebsd.org>. Don't be fooled by the
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* code's apparent simplicity; there would be no need for this function if it
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* was easy to get right.
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*/
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static int
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vflopenat(int dirfd, const char *path, int flags, va_list ap)
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{
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int fd, operation, serrno, trunc;
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struct stat sb, fsb;
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mode_t mode;
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#ifdef O_EXLOCK
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flags &= ~O_EXLOCK;
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#endif
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mode = 0;
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if (flags & O_CREAT) {
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mode = (mode_t)va_arg(ap, int); /* mode_t promoted to int */
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}
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operation = LOCK_EX;
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if (flags & O_NONBLOCK)
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operation |= LOCK_NB;
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trunc = (flags & O_TRUNC);
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flags &= ~O_TRUNC;
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for (;;) {
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if ((fd = openat(dirfd, path, flags, mode)) == -1)
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/* non-existent or no access */
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return (-1);
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if (flock(fd, operation) == -1) {
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/* unsupported or interrupted */
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serrno = errno;
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(void)close(fd);
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errno = serrno;
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return (-1);
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}
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if (fstatat(dirfd, path, &sb, 0) == -1) {
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/* disappeared from under our feet */
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(void)close(fd);
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continue;
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}
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if (fstat(fd, &fsb) == -1) {
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/* can't happen [tm] */
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serrno = errno;
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(void)close(fd);
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errno = serrno;
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return (-1);
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}
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if (sb.st_dev != fsb.st_dev ||
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sb.st_ino != fsb.st_ino) {
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/* changed under our feet */
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(void)close(fd);
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continue;
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}
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if (trunc && ftruncate(fd, 0) != 0) {
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/* can't happen [tm] */
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serrno = errno;
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(void)close(fd);
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errno = serrno;
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return (-1);
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}
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/*
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* The following change is provided as a specific example to
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* avoid.
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*/
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#if 0
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if (fcntl(fd, F_SETFD, FD_CLOEXEC) != 0) {
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serrno = errno;
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(void)close(fd);
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errno = serrno;
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return (-1);
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}
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#endif
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return (fd);
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}
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}
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int
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flopen(const char *path, int flags, ...)
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{
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va_list ap;
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int ret;
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va_start(ap, flags);
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ret = vflopenat(AT_FDCWD, path, flags, ap);
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va_end(ap);
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return (ret);
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}
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int
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flopenat(int dirfd, const char *path, int flags, ...)
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{
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va_list ap;
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int ret;
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va_start(ap, flags);
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ret = vflopenat(dirfd, path, flags, ap);
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va_end(ap);
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return (ret);
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}
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