diff options
| -rw-r--r-- | libio/freopen.c | 4 | ||||
| -rw-r--r-- | libio/freopen64.c | 4 | ||||
| -rw-r--r-- | misc/Makefile | 6 | ||||
| -rw-r--r-- | misc/fd_to_filename.c | 38 | ||||
| -rw-r--r-- | misc/tst-fd_to_filename.c | 101 | ||||
| -rw-r--r-- | sysdeps/generic/arch-fd_to_filename.h | 19 | ||||
| -rw-r--r-- | sysdeps/generic/fd_to_filename.h | 26 | ||||
| -rw-r--r-- | sysdeps/mach/hurd/arch-fd_to_filename.h | 19 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/arch-fd_to_filename.h (renamed from sysdeps/unix/sysv/linux/fd_to_filename.h) | 22 |
9 files changed, 206 insertions, 33 deletions
diff --git a/libio/freopen.c b/libio/freopen.c index bab3ba204a..884cdb2961 100644 --- a/libio/freopen.c +++ b/libio/freopen.c @@ -37,7 +37,7 @@ FILE * freopen (const char *filename, const char *mode, FILE *fp) { FILE *result = NULL; - char fdfilename[FD_TO_FILENAME_SIZE]; + struct fd_to_filename fdfilename; CHECK_FILE (fp, NULL); @@ -50,7 +50,7 @@ freopen (const char *filename, const char *mode, FILE *fp) int fd = _IO_fileno (fp); const char *gfilename - = filename != NULL ? filename : fd_to_filename (fd, fdfilename); + = filename != NULL ? filename : __fd_to_filename (fd, &fdfilename); fp->_flags2 |= _IO_FLAGS2_NOCLOSE; #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) diff --git a/libio/freopen64.c b/libio/freopen64.c index c0ce604e6e..0d2c5264c7 100644 --- a/libio/freopen64.c +++ b/libio/freopen64.c @@ -36,7 +36,7 @@ FILE * freopen64 (const char *filename, const char *mode, FILE *fp) { FILE *result = NULL; - char fdfilename[FD_TO_FILENAME_SIZE]; + struct fd_to_filename fdfilename; CHECK_FILE (fp, NULL); @@ -49,7 +49,7 @@ freopen64 (const char *filename, const char *mode, FILE *fp) int fd = _IO_fileno (fp); const char *gfilename - = filename != NULL ? filename : fd_to_filename (fd, fdfilename); + = filename != NULL ? filename : __fd_to_filename (fd, &fdfilename); fp->_flags2 |= _IO_FLAGS2_NOCLOSE; _IO_file_close_it (fp); diff --git a/misc/Makefile b/misc/Makefile index e0465980c7..b8fed5783d 100644 --- a/misc/Makefile +++ b/misc/Makefile @@ -72,7 +72,7 @@ routines := brk sbrk sstk ioctl \ fgetxattr flistxattr fremovexattr fsetxattr getxattr \ listxattr lgetxattr llistxattr lremovexattr lsetxattr \ removexattr setxattr getauxval ifunc-impl-list makedev \ - allocate_once + allocate_once fd_to_filename generated += tst-error1.mtrace tst-error1-mem.out \ tst-allocate_once.mtrace tst-allocate_once-mem.out @@ -97,6 +97,10 @@ endif tests-internal := tst-atomic tst-atomic-long tst-allocate_once tests-static := tst-empty +# Test for the internal, non-exported __fd_to_filename function. +tests-internal += tst-fd_to_filename +tests-static += tst-fd_to_filename + ifeq ($(run-built-tests),yes) tests-special += $(objpfx)tst-error1-mem.out \ $(objpfx)tst-allocate_once-mem.out diff --git a/misc/fd_to_filename.c b/misc/fd_to_filename.c new file mode 100644 index 0000000000..03d19194c1 --- /dev/null +++ b/misc/fd_to_filename.c @@ -0,0 +1,38 @@ +/* Construct a pathname under /proc/self/fd (or /dev/fd for Hurd). + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <fd_to_filename.h> + +#include <assert.h> +#include <string.h> + +char * +__fd_to_filename (int descriptor, struct fd_to_filename *storage) +{ + assert (descriptor >= 0); + + char *p = mempcpy (storage->buffer, FD_TO_FILENAME_PREFIX, + strlen (FD_TO_FILENAME_PREFIX)); + + for (int d = descriptor; p++, (d /= 10) != 0; ) + continue; + *p = '\0'; + for (int d = descriptor; *--p = '0' + d % 10, (d /= 10) != 0; ) + continue; + return storage->buffer; +} diff --git a/misc/tst-fd_to_filename.c b/misc/tst-fd_to_filename.c new file mode 100644 index 0000000000..d16c869cd3 --- /dev/null +++ b/misc/tst-fd_to_filename.c @@ -0,0 +1,101 @@ +/* Test for /proc/self/fd (or /dev/fd) pathname construction. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <fcntl.h> +#include <fd_to_filename.h> +#include <stdio.h> +#include <support/check.h> +#include <support/xunistd.h> + +/* Run a check on one value. */ +static void +check (int value) +{ + if (value < 0) + /* Negative descriptor values violate the precondition. */ + return; + + struct fd_to_filename storage; + char *actual = __fd_to_filename (value, &storage); + char expected[100]; + snprintf (expected, sizeof (expected), FD_TO_FILENAME_PREFIX "%d", value); + TEST_COMPARE_STRING (actual, expected); +} + +/* Check various ranges constructed around powers. */ +static void +check_ranges (int base) +{ + unsigned int power = 1; + do + { + for (int factor = 1; factor < base; ++factor) + for (int shift = -1000; shift <= 1000; ++shift) + check (factor * power + shift); + } + while (!__builtin_mul_overflow (power, base, &power)); +} + +/* Check that it is actually possible to use a the constructed + name. */ +static void +check_open (void) +{ + int pipes[2]; + xpipe (pipes); + + struct fd_to_filename storage; + int read_alias = xopen (__fd_to_filename (pipes[0], &storage), O_RDONLY, 0); + int write_alias = xopen (__fd_to_filename (pipes[1], &storage), O_WRONLY, 0); + + /* Ensure that all the descriptor numbers are different. */ + TEST_VERIFY (pipes[0] < pipes[1]); + TEST_VERIFY (pipes[1] < read_alias); + TEST_VERIFY (read_alias < write_alias); + + xwrite (write_alias, "1", 1); + char buf[16]; + TEST_COMPARE_BLOB ("1", 1, buf, read (pipes[0], buf, sizeof (buf))); + + xwrite (pipes[1], "2", 1); + TEST_COMPARE_BLOB ("2", 1, buf, read (read_alias, buf, sizeof (buf))); + + xwrite (write_alias, "3", 1); + TEST_COMPARE_BLOB ("3", 1, buf, read (read_alias, buf, sizeof (buf))); + + xwrite (pipes[1], "4", 1); + TEST_COMPARE_BLOB ("4", 1, buf, read (pipes[0], buf, sizeof (buf))); + + xclose (write_alias); + xclose (read_alias); + xclose (pipes[1]); + xclose (pipes[0]); +} + +static int +do_test (void) +{ + check_ranges (2); + check_ranges (10); + + check_open (); + + return 0; +} + +#include <support/test-driver.c> diff --git a/sysdeps/generic/arch-fd_to_filename.h b/sysdeps/generic/arch-fd_to_filename.h new file mode 100644 index 0000000000..ecaaa14dba --- /dev/null +++ b/sysdeps/generic/arch-fd_to_filename.h @@ -0,0 +1,19 @@ +/* Query filename corresponding to an open FD. Generic stub. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#error "<arch-fd_to_filename.h> must be ported to this architecture" diff --git a/sysdeps/generic/fd_to_filename.h b/sysdeps/generic/fd_to_filename.h index eff6ca211b..5ca22f02bc 100644 --- a/sysdeps/generic/fd_to_filename.h +++ b/sysdeps/generic/fd_to_filename.h @@ -1,4 +1,4 @@ -/* Query filename corresponding to an open FD. Generic version. +/* Query filename corresponding to an open FD. Copyright (C) 2001-2020 Free Software Foundation, Inc. This file is part of the GNU C Library. @@ -16,12 +16,22 @@ License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ -#define FD_TO_FILENAME_SIZE 0 +#ifndef _FD_TO_FILENAME_H +#define _FD_TO_FILENAME_H -/* In general there is no generic way to query filename for an open - file descriptor. */ -static inline const char * -fd_to_filename (int fd, char *buf) +#include <arch-fd_to_filename.h> +#include <intprops.h> + +struct fd_to_filename { - return NULL; -} + /* A positive int value has at most 10 decimal digits. */ + char buffer[sizeof (FD_TO_FILENAME_PREFIX) + INT_STRLEN_BOUND (int)]; +}; + +/* Writes a /proc/self/fd-style path for DESCRIPTOR to *STORAGE and + returns a pointer to the start of the string. DESCRIPTOR must be + non-negative. */ +char *__fd_to_filename (int descriptor, struct fd_to_filename *storage) + attribute_hidden; + +#endif /* _FD_TO_FILENAME_H */ diff --git a/sysdeps/mach/hurd/arch-fd_to_filename.h b/sysdeps/mach/hurd/arch-fd_to_filename.h new file mode 100644 index 0000000000..b45cd8d836 --- /dev/null +++ b/sysdeps/mach/hurd/arch-fd_to_filename.h @@ -0,0 +1,19 @@ +/* Query filename corresponding to an open FD. Hurd version. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#define FD_TO_FILENAME_PREFIX "/dev/fd/" diff --git a/sysdeps/unix/sysv/linux/fd_to_filename.h b/sysdeps/unix/sysv/linux/arch-fd_to_filename.h index 92a5e02976..b6017214c7 100644 --- a/sysdeps/unix/sysv/linux/fd_to_filename.h +++ b/sysdeps/unix/sysv/linux/arch-fd_to_filename.h @@ -1,5 +1,5 @@ /* Query filename corresponding to an open FD. Linux version. - Copyright (C) 2001-2020 Free Software Foundation, Inc. + Copyright (C) 2020 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -16,22 +16,4 @@ License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ -#include <sys/stat.h> -#include <string.h> -#include <_itoa.h> - -#define FD_TO_FILENAME_SIZE ((sizeof ("/proc/self/fd/") - 1) \ - + (sizeof ("4294967295") - 1) + 1) - -static inline const char * -fd_to_filename (unsigned int fd, char *buf) -{ - *_fitoa_word (fd, __stpcpy (buf, "/proc/self/fd/"), 10, 0) = '\0'; - - /* We must make sure the file exists. */ - struct stat64 st; - if (__lxstat64 (_STAT_VER, buf, &st) < 0) - /* /proc is not mounted or something else happened. */ - return NULL; - return buf; -} +#define FD_TO_FILENAME_PREFIX "/proc/self/fd/" |