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/*
htop - Compat.c
(C) 2020 htop dev team
Released under the GNU GPLv2+, see the COPYING file
in the source distribution for its full text.
*/
#include "config.h" // IWYU pragma: keep
#include "Compat.h"
#include <errno.h>
#include <fcntl.h> // IWYU pragma: keep
#include <limits.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h> // IWYU pragma: keep
#include "XUtils.h" // IWYU pragma: keep
/* GNU/Hurd does not have PATH_MAX in limits.h */
#ifndef PATH_MAX
# define PATH_MAX 4096
#endif
int Compat_faccessat(int dirfd,
const char* pathname,
int mode,
int flags) {
int ret;
#ifdef HAVE_FACCESSAT
// Implementation note: AT_SYMLINK_NOFOLLOW unsupported on FreeBSD, fallback to lstat in that case
errno = 0;
ret = faccessat(dirfd, pathname, mode, flags);
if (!ret || errno != EINVAL)
return ret;
#endif
// Error out on unsupported configurations
if (dirfd != (int)AT_FDCWD || mode != F_OK) {
errno = EINVAL;
return -1;
}
// Fallback to stat(2)/lstat(2) depending on flags
struct stat sb;
if (flags) {
ret = lstat(pathname, &sb);
} else {
ret = stat(pathname, &sb);
}
return ret;
}
int Compat_fstatat(int dirfd,
const char* dirpath,
const char* pathname,
struct stat* statbuf,
int flags) {
#ifdef HAVE_FSTATAT
(void)dirpath;
return fstatat(dirfd, pathname, statbuf, flags);
#else
(void)dirfd;
char path[4096];
xSnprintf(path, sizeof(path), "%s/%s", dirpath, pathname);
if (flags & AT_SYMLINK_NOFOLLOW)
return lstat(path, statbuf);
return stat(path, statbuf);
#endif
}
#ifndef HAVE_OPENAT
int Compat_openat(const char* dirpath,
const char* pathname,
int flags) {
char path[4096];
xSnprintf(path, sizeof(path), "%s/%s", dirpath, pathname);
return open(path, flags);
}
#endif /* !HAVE_OPENAT */
ssize_t Compat_readlinkat(int dirfd,
const char* dirpath,
const char* pathname,
char* buf,
size_t bufsize) {
#ifdef HAVE_READLINKAT
(void)dirpath;
return readlinkat(dirfd, pathname, buf, bufsize);
#else
(void)dirfd;
char path[4096];
xSnprintf(path, sizeof(path), "%s/%s", dirpath, pathname);
return readlink(path, buf, bufsize);
#endif
}
ssize_t Compat_readlink(openat_arg_t dirfd,
const char* pathname,
char* buf,
size_t bufsize) {
#ifdef HAVE_OPENAT
char fdPath[32];
xSnprintf(fdPath, sizeof(fdPath), "/proc/self/fd/%d", dirfd);
char dirPath[PATH_MAX + 1];
ssize_t r = readlink(fdPath, dirPath, sizeof(dirPath) - 1);
if (r < 0)
return r;
dirPath[r] = '\0';
char linkPath[PATH_MAX + 1];
xSnprintf(linkPath, sizeof(linkPath), "%s/%s", dirPath, pathname);
#else
char linkPath[PATH_MAX + 1];
xSnprintf(linkPath, sizeof(linkPath), "%s/%s", dirfd, pathname);
#endif /* HAVE_OPENAT */
return readlink(linkPath, buf, bufsize);
}
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