[PATCH v3 1/5] libcsupport: Added futimens() and utimensat()
Ryan Long
ryan.long at oarcorp.com
Wed May 12 13:33:38 UTC 2021
Created futimens.c and utimensat.c to add support for the POSIX
methods futimens() and utimensat().
utime() and utimes() are considered obsolote by POSIX, but RTEMS
will continue to support them.
Closes #4396
---
cpukit/Makefile.am | 2 +
cpukit/include/rtems/libio_.h | 64 ++++++++-
cpukit/include/rtems/score/timespec.h | 16 ++-
cpukit/libcsupport/src/futimens.c | 87 ++++++++++++
cpukit/libcsupport/src/utimensat.c | 224 +++++++++++++++++++++++++++++++
cpukit/score/src/timespecisnonnegative.c | 35 +++++
spec/build/cpukit/librtemscpu.yml | 3 +
7 files changed, 426 insertions(+), 5 deletions(-)
create mode 100644 cpukit/libcsupport/src/futimens.c
create mode 100644 cpukit/libcsupport/src/utimensat.c
create mode 100644 cpukit/score/src/timespecisnonnegative.c
diff --git a/cpukit/Makefile.am b/cpukit/Makefile.am
index b0df610..29b4207 100644
--- a/cpukit/Makefile.am
+++ b/cpukit/Makefile.am
@@ -262,6 +262,8 @@ librtemscpu_a_SOURCES += libcsupport/src/unmount.c
librtemscpu_a_SOURCES += libcsupport/src/__usrenv.c
librtemscpu_a_SOURCES += libcsupport/src/utime.c
librtemscpu_a_SOURCES += libcsupport/src/utimes.c
+librtemscpu_a_SOURCES += libcsupport/src/futimens.c
+librtemscpu_a_SOURCES += libcsupport/src/utimensat.c
librtemscpu_a_SOURCES += libcsupport/src/utsname.c
librtemscpu_a_SOURCES += libcsupport/src/vprintk.c
librtemscpu_a_SOURCES += libcsupport/src/write.c
diff --git a/cpukit/include/rtems/libio_.h b/cpukit/include/rtems/libio_.h
index e9eb462..b7455ef 100644
--- a/cpukit/include/rtems/libio_.h
+++ b/cpukit/include/rtems/libio_.h
@@ -2,13 +2,12 @@
* @file
*
* @brief LibIO Internal Interface
- *
+ *
* This file is the libio internal interface.
*/
/*
- * COPYRIGHT (c) 1989-2011.
- * On-Line Applications Research Corporation (OAR).
+ * COPYRIGHT (C) 1989, 2021 On-Line Applications Research Corporation (OAR).
*
* Modifications to support reference counting in the file system are
* Copyright (c) 2012 embedded brains GmbH.
@@ -30,6 +29,7 @@
#include <rtems/libio.h>
#include <rtems/seterr.h>
#include <rtems/score/assert.h>
+#include <rtems/score/timespec.h>
#ifdef __cplusplus
extern "C" {
@@ -357,6 +357,64 @@ static inline void rtems_filesystem_instance_unlock(
(*mt_entry->ops->unlock_h)( mt_entry );
}
+/**
+ * @brief Checks the tv_nsec member of a timespec struct
+ *
+ * This function is used with utimensat() and futimens() only. This ensures
+ * that the value in the tv_nsec member is equal to either UTIME_NOW,
+ * UTIME_OMIT, or a value greater-than or equal to zero and less than a
+ * billion.
+ *
+ * @param[in] time The timespec struct to be validated
+ *
+ * @retval Returns true if tv_nsec member is a valid value, otherwise false.
+ */
+bool rtems_filesystem_utime_tv_nsec_valid( struct timespec time );
+
+/**
+ * @brief Determines if the process has write permissions to a file
+ *
+ * The timespec at index 0 is the access time, the timespec at index 1 is the
+ * modification time.
+ *
+ * This function is only used with utimensat() and futimens(). This checks
+ * whether the process has write access to a file, and checks for EACCES
+ * and EPERM errors depending on what values are in @times and if the process
+ * has write permissions to the file.
+ *
+ * @param[in] currentloc The current location to a file
+ * @param[in] times The timespec instance that will update the timestamps
+ *
+ * @retval Returns 0 if the process has write permissions, otherwise -1.
+ */
+int rtems_filesystem_utime_check_permissions(
+ const rtems_filesystem_location_info_t *currentloc,
+ const struct timespec times[2]
+);
+
+/**
+ * @brief Checks @times and fills @new_times with the time to be written
+ *
+ * For each of the arguments, the timespec at index 0 is the access time, and
+ * the timespec at index 1 is the modification time.
+ *
+ * This function is only used with utimensat() and futimens(). @times contains
+ * the constant values passed into utimensat/futimens. @new_times contains the
+ * values that will be written to the file. These values depend on @times. If
+ * @times is NULL, or either of its elements' tv_nsec members are UTIME_NOW,
+ * the current elapsed time in nanoseconds will be saved in the corresponding
+ * location in @new_times.
+ *
+ * @param[in] times The timespecs to be checked
+ * @param[in,out] new_times The timespecs containing the time to be written
+ *
+ * @retval Returns 0 if @times is valid, otherwise -1.
+ */
+int rtems_filesystem_utime_check_times(
+ const struct timespec times[2],
+ struct timespec new_times[2]
+);
+
/*
* File Descriptor Routine Prototypes
*/
diff --git a/cpukit/include/rtems/score/timespec.h b/cpukit/include/rtems/score/timespec.h
index 314d804..3671067 100644
--- a/cpukit/include/rtems/score/timespec.h
+++ b/cpukit/include/rtems/score/timespec.h
@@ -8,8 +8,7 @@
*/
/*
- * COPYRIGHT (c) 1989-2009.
- * On-Line Applications Research Corporation (OAR).
+ * COPYRIGHT (C) 1989, 2021 On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
@@ -106,6 +105,19 @@ uint64_t _Timespec_Get_as_nanoseconds(
);
/**
+ * @brief Checks the tv_sec member of a timespec struct
+ *
+ * @param[in] time is the timespec instance to validate.
+ *
+ * Ensures that the values in @a time are non-negative.
+ *
+ * @retval Returns true if the tv_sec member is a valid value, otherwise false.
+ */
+bool _Timespec_Is_non_negative(
+ const struct timespec *time
+);
+
+/**
* @brief Checks if timespec is valid.
*
* This method determines the validity of a timespec.
diff --git a/cpukit/libcsupport/src/futimens.c b/cpukit/libcsupport/src/futimens.c
new file mode 100644
index 0000000..44ec03d
--- /dev/null
+++ b/cpukit/libcsupport/src/futimens.c
@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup libcsupport
+ *
+ * @brief Set file access and modification times based on file descriptor in
+ * nanoseconds.
+ */
+
+/*
+ * COPYRIGHT (C) 2021 On-Line Applications Research Corporation (OAR).
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <sys/stat.h>
+#include <rtems/libio_.h>
+
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+
+/**
+ * https://pubs.opengroup.org/onlinepubs/9699919799.2008edition/functions/futimens.html
+ *
+ * Set file access and modification times
+ */
+int futimens(
+ int fd,
+ const struct timespec times[2]
+)
+{
+ int rv;
+ rtems_libio_t *iop;
+ struct timespec new_times[2];
+ const rtems_filesystem_location_info_t *currentloc = NULL;
+
+ LIBIO_GET_IOP_WITH_ACCESS( fd, iop, LIBIO_FLAGS_READ, EBADF );
+
+ currentloc = &iop->pathinfo;
+
+ rv = rtems_filesystem_utime_check_times( times, new_times );
+ if ( rv != 0 ) {
+ rtems_libio_iop_drop( iop );
+ return rv;
+ }
+
+ rv = rtems_filesystem_utime_check_permissions( currentloc, times );
+ if ( rv != 0 ) {
+ rtems_libio_iop_drop( iop );
+ return rv;
+ }
+
+ rv = (*currentloc->mt_entry->ops->utimens_h)(
+ currentloc,
+ new_times
+ );
+
+ rtems_libio_iop_drop( iop );
+
+ return rv;
+}
diff --git a/cpukit/libcsupport/src/utimensat.c b/cpukit/libcsupport/src/utimensat.c
new file mode 100644
index 0000000..59ba369
--- /dev/null
+++ b/cpukit/libcsupport/src/utimensat.c
@@ -0,0 +1,224 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup libcsupport
+ *
+ * @brief Set file access and modification times in nanoseconds.
+ */
+
+/*
+ * COPYRIGHT (C) 2021 On-Line Applications Research Corporation (OAR).
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/libio_.h>
+
+#include <fcntl.h>
+#include <string.h>
+
+/*
+ * Make sure that tv_nsec is either UTIME_NOW, UTIME_OMIT, a value
+ * greater than zero, or a value less-than a billion.
+ *
+ * These guidelines come from the description of the EINVAL errors on
+ * https://pubs.opengroup.org/onlinepubs/9699919799/functions/futimens.html
+ */
+bool rtems_filesystem_utime_tv_nsec_valid(struct timespec time)
+{
+ if ( time.tv_nsec == UTIME_NOW ) {
+ return true;
+ }
+
+ if ( time.tv_nsec == UTIME_OMIT ) {
+ return true;
+ }
+
+ if ( time.tv_nsec < 0 ) {
+ return false;
+ }
+
+ if ( time.tv_nsec > 999999999 ) {
+ return false;
+ }
+
+ return true;
+}
+
+/* Determine whether the access and modified timestamps can be updated */
+int rtems_filesystem_utime_check_permissions(
+ const rtems_filesystem_location_info_t * currentloc,
+ const struct timespec times[2]
+)
+{
+ struct stat st = {};
+ int rv;
+ bool write_access;
+
+ rv = (*currentloc->handlers->fstat_h)( currentloc, &st );
+ if ( rv != 0 ) {
+ rtems_set_errno_and_return_minus_one( ENOENT );
+ }
+
+ write_access = rtems_filesystem_check_access(
+ RTEMS_FS_PERMS_WRITE,
+ st.st_mode,
+ st.st_uid,
+ st.st_gid
+ );
+
+ /*
+ * The logic for the EACCES error is an inverted subset of the EPERM
+ * conditional according to the POSIX standard.
+ */
+ if ( (times == NULL) ||
+ ( (times[0].tv_nsec == UTIME_NOW) && (times[1].tv_nsec == UTIME_NOW) )) {
+ if ( !write_access ) {
+ rtems_set_errno_and_return_minus_one( EACCES );
+ }
+ } else {
+ if ( times[0].tv_nsec != UTIME_OMIT || times[1].tv_nsec != UTIME_OMIT ) {
+ if ( !write_access ) {
+ rtems_set_errno_and_return_minus_one( EPERM );
+ }
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Determine if the current time needs to be gotten, and then check
+ * whether the values in times are valid.
+ */
+int rtems_filesystem_utime_check_times(
+ const struct timespec times[2],
+ struct timespec new_times[2]
+)
+{
+ bool got_time = false;
+ struct timespec now;
+
+ /*
+ * If times is NULL, it's equivalent to adding UTIME_NOW in both time
+ * elements
+ */
+ if ( times == NULL ) {
+ _Timespec_Set( &new_times[0], 0, UTIME_NOW );
+ _Timespec_Set( &new_times[1], 0, UTIME_NOW );
+ } else {
+ new_times[0] = times[0];
+ new_times[1] = times[1];
+ }
+
+ if ( new_times[0].tv_nsec == UTIME_NOW ) {
+ clock_gettime( CLOCK_REALTIME, &now );
+ new_times[0] = now;
+ got_time = true;
+ }
+
+ if ( new_times[1].tv_nsec == UTIME_NOW ) {
+ if ( !got_time ) {
+ clock_gettime( CLOCK_REALTIME, &now );
+ }
+ new_times[1] = now;
+ }
+
+ if ( !_Timespec_Is_non_negative( &new_times[0] ) ) {
+ rtems_set_errno_and_return_minus_one( EINVAL );
+ }
+
+ if ( !_Timespec_Is_non_negative( &new_times[1] ) ) {
+ rtems_set_errno_and_return_minus_one( EINVAL );
+ }
+
+ if ( !rtems_filesystem_utime_tv_nsec_valid( new_times[0] ) ) {
+ rtems_set_errno_and_return_minus_one( EINVAL );
+ }
+
+ if ( !rtems_filesystem_utime_tv_nsec_valid( new_times[1] ) ) {
+ rtems_set_errno_and_return_minus_one( EINVAL );
+ }
+
+ return 0;
+}
+
+/**
+ * https://pubs.opengroup.org/onlinepubs/9699919799.2008edition/functions/futimens.html
+ *
+ * Set file access and modification times
+ */
+int utimensat(
+ int fd,
+ const char *path,
+ const struct timespec times[2],
+ int flag
+)
+{
+ int rv = 0;
+ rtems_filesystem_eval_path_context_t ctx;
+ int eval_flags = RTEMS_FS_FOLLOW_LINK;
+ const rtems_filesystem_location_info_t *currentloc = NULL;
+ struct timespec new_times[2];
+
+ /*
+ * RTEMS does not currently support operating on a real file descriptor
+ */
+ if ( fd != AT_FDCWD ) {
+ rtems_set_errno_and_return_minus_one( ENOSYS );
+ }
+
+ /*
+ * RTEMS does not currently support AT_SYMLINK_NOFOLLOW
+ */
+ if ( flag != 0 ) {
+ rtems_set_errno_and_return_minus_one( ENOSYS );
+ }
+
+ rv = rtems_filesystem_utime_check_times( times, new_times );
+ if ( rv != 0 ) {
+ return rv;
+ }
+
+ currentloc = rtems_filesystem_eval_path_start( &ctx, path, eval_flags );
+
+ rv = rtems_filesystem_utime_check_permissions( currentloc, times );
+ if ( rv != 0 ) {
+ rtems_filesystem_eval_path_cleanup( &ctx );
+ return rv;
+ }
+
+ rv = (*currentloc->mt_entry->ops->utimens_h)(
+ currentloc,
+ new_times
+ );
+
+ rtems_filesystem_eval_path_cleanup( &ctx );
+
+ return rv;
+}
diff --git a/cpukit/score/src/timespecisnonnegative.c b/cpukit/score/src/timespecisnonnegative.c
new file mode 100644
index 0000000..080e961
--- /dev/null
+++ b/cpukit/score/src/timespecisnonnegative.c
@@ -0,0 +1,35 @@
+/**
+ * @file
+ *
+ * @ingroup RTEMSScoreTimespec
+ *
+ * @brief This source file contains the implementation of
+ * _Timespec_Is_non_negative().
+ */
+
+/*
+ * COPYRIGHT (C) 2021 On-Line Applications Research Corporation (OAR).
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/score/timespec.h>
+
+bool _Timespec_Is_non_negative(
+ const struct timespec *time
+)
+{
+ if ( time->tv_sec < 0 )
+ return false;
+
+ if ( time->tv_nsec < 0 )
+ return false;
+
+ return true;
+}
diff --git a/spec/build/cpukit/librtemscpu.yml b/spec/build/cpukit/librtemscpu.yml
index a3a9ee4..7f36ef7 100644
--- a/spec/build/cpukit/librtemscpu.yml
+++ b/spec/build/cpukit/librtemscpu.yml
@@ -761,6 +761,8 @@ source:
- cpukit/libcsupport/src/unmount.c
- cpukit/libcsupport/src/utime.c
- cpukit/libcsupport/src/utimes.c
+- cpukit/libcsupport/src/futimens.c
+- cpukit/libcsupport/src/utimensat.c
- cpukit/libcsupport/src/utsname.c
- cpukit/libcsupport/src/vprintk.c
- cpukit/libcsupport/src/write.c
@@ -1558,6 +1560,7 @@ source:
- cpukit/score/src/threadyield.c
- cpukit/score/src/timespecaddto.c
- cpukit/score/src/timespecdivide.c
+- cpukit/score/src/timespecisnonnegative.c
- cpukit/score/src/timespecdividebyinteger.c
- cpukit/score/src/timespecfromticks.c
- cpukit/score/src/timespecgetasnanoseconds.c
--
1.8.3.1
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