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109 lines
2.1 KiB
109 lines
2.1 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Author: Aleksa Sarai <[email protected]> |
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* Copyright (C) 2018-2019 SUSE LLC. |
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*/ |
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#define _GNU_SOURCE |
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#include <errno.h> |
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#include <fcntl.h> |
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#include <stdbool.h> |
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#include <string.h> |
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#include <syscall.h> |
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#include <limits.h> |
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#include "helpers.h" |
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bool needs_openat2(const struct open_how *how) |
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{ |
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return how->resolve != 0; |
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} |
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int raw_openat2(int dfd, const char *path, void *how, size_t size) |
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{ |
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int ret = syscall(__NR_openat2, dfd, path, how, size); |
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return ret >= 0 ? ret : -errno; |
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} |
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int sys_openat2(int dfd, const char *path, struct open_how *how) |
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{ |
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return raw_openat2(dfd, path, how, sizeof(*how)); |
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} |
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int sys_openat(int dfd, const char *path, struct open_how *how) |
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{ |
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int ret = openat(dfd, path, how->flags, how->mode); |
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return ret >= 0 ? ret : -errno; |
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} |
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int sys_renameat2(int olddirfd, const char *oldpath, |
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int newdirfd, const char *newpath, unsigned int flags) |
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{ |
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int ret = syscall(__NR_renameat2, olddirfd, oldpath, |
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newdirfd, newpath, flags); |
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return ret >= 0 ? ret : -errno; |
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} |
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int touchat(int dfd, const char *path) |
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{ |
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int fd = openat(dfd, path, O_CREAT, 0700); |
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if (fd >= 0) |
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close(fd); |
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return fd; |
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} |
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char *fdreadlink(int fd) |
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{ |
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char *target, *tmp; |
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E_asprintf(&tmp, "/proc/self/fd/%d", fd); |
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target = malloc(PATH_MAX); |
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if (!target) |
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ksft_exit_fail_msg("fdreadlink: malloc failed\n"); |
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memset(target, 0, PATH_MAX); |
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E_readlink(tmp, target, PATH_MAX); |
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free(tmp); |
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return target; |
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} |
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bool fdequal(int fd, int dfd, const char *path) |
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{ |
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char *fdpath, *dfdpath, *other; |
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bool cmp; |
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fdpath = fdreadlink(fd); |
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dfdpath = fdreadlink(dfd); |
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if (!path) |
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E_asprintf(&other, "%s", dfdpath); |
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else if (*path == '/') |
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E_asprintf(&other, "%s", path); |
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else |
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E_asprintf(&other, "%s/%s", dfdpath, path); |
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cmp = !strcmp(fdpath, other); |
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free(fdpath); |
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free(dfdpath); |
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free(other); |
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return cmp; |
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} |
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bool openat2_supported = false; |
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void __attribute__((constructor)) init(void) |
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{ |
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struct open_how how = {}; |
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int fd; |
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BUILD_BUG_ON(sizeof(struct open_how) != OPEN_HOW_SIZE_VER0); |
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/* Check openat2(2) support. */ |
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fd = sys_openat2(AT_FDCWD, ".", &how); |
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openat2_supported = (fd >= 0); |
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if (fd >= 0) |
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close(fd); |
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}
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