fs: support openat/fchmodat/mkfifoat/fstatat/...at api

Refs to:
https://linux.die.net/man/2/openat

Signed-off-by: dongjiuzhu1 <dongjiuzhu1@xiaomi.com>

include/fcntl.h

@@ -112,6 +112,18 @@
 
 #define FD_CLOEXEC  1
 
+/* The flag for openat, faccessat, ... */
+
+#define AT_FDCWD              -100   /* Special value used to indicate openat should use the current
+                                      * working directory.
+                                      */
+#define AT_SYMLINK_NOFOLLOW   0x0100 /* Do not follow symbolic links. */
+#define AT_EACCESS            0x0200 /* Test access permitted for effective IDs, not real IDs. */
+#define AT_REMOVEDIR          0x0200 /* Remove directory instead of unlinking file. */
+#define AT_SYMLINK_FOLLOW     0x0400 /* Follow symbolic links. */
+#define AT_NO_AUTOMOUNT       0x0800 /* Suppress terminal automount traversal */
+#define AT_EMPTY_PATH         0x1000 /* Allow empty relative pathname */
+
 /* These are the notifications that can be received from F_NOTIFY (linux) */
 
 #define DN_ACCESS   0  /* A file was accessed */
@@ -185,6 +197,7 @@ extern "C"
 /* POSIX-like File System Interfaces */
 
 int open(FAR const char *path, int oflag, ...);
+int openat(int dirfd, FAR const char *path, int oflag, ...);
 int fcntl(int fd, int cmd, ...);
 
 int posix_fallocate(int fd, off_t offset, off_t len);

include/stdio.h

@@ -188,6 +188,8 @@ int    putc(int c, FAR FILE *stream);
 int    putchar(int c);
 int    puts(FAR const IPTR char *s);
 int    rename(FAR const char *oldpath, FAR const char *newpath);
+int    renameat(int olddirfd, FAR const char *oldpath,
+                int newdirfd, FAR const char *newpath);
 int    sprintf(FAR char *buf, FAR const IPTR char *fmt, ...)
        printf_like(2, 3);
 int    asprintf(FAR char **ptr, FAR const IPTR char *fmt, ...)

include/sys/stat.h

@@ -171,15 +171,23 @@ extern "C"
 #endif
 
 int mkdir(FAR const char *pathname, mode_t mode);
+int mkdirat(int dirfd, FAR const char *pathname, mode_t mode);
 int mkfifo(FAR const char *pathname, mode_t mode);
+int mkfifoat(int dirfd, FAR const char *pathname, mode_t mode);
 int mknod(FAR const char *path, mode_t mode, dev_t dev);
+int mknodat(int dirfd, FAR const char *path, mode_t mode, dev_t dev);
 int stat(FAR const char *path, FAR struct stat *buf);
 int lstat(FAR const char *path, FAR struct stat *buf);
 int fstat(int fd, FAR struct stat *buf);
+int fstatat(int dirfd, FAR const char *path, FAR struct stat *buf,
+            int flags);
 int chmod(FAR const char *path, mode_t mode);
 int lchmod(FAR const char *path, mode_t mode);
 int fchmod(int fd, mode_t mode);
+int fchmodat(int dirfd, FAR const char *path, mode_t mode, int flags);
 int utimens(FAR const char *path, const struct timespec times[2]);
+int utimensat(int dirfd, FAR const char *path,
+              const struct timespec times[2], int flags);
 int lutimens(FAR const char *path, const struct timespec times[2]);
 int futimens(int fd, const struct timespec times[2]);
 

include/sys/time.h

@@ -373,6 +373,8 @@ int setitimer(int which, FAR const struct itimerval *value,
 
 int utimes(FAR const char *path, const struct timeval times[2]);
 int lutimes(FAR const char *path, const struct timeval times[2]);
+int futimesat(int dirfd, FAR const char *path,
+              const struct timeval times[2]);
 
 /****************************************************************************
  * Name: futimes

include/unistd.h

@@ -368,14 +368,24 @@ FAR char *getcwd(FAR char *buf, size_t size);
 /* File path operations */
 
 int     access(FAR const char *path, int amode);
+int     faccessat(int dirfd, FAR const char *path, int mode, int flags);
 int     rmdir(FAR const char *pathname);
 int     unlink(FAR const char *pathname);
+int     unlinkat(int dirfd, FAR const char *pathname, int flags);
 int     truncate(FAR const char *path, off_t length);
 int     link(FAR const char *path1, FAR const char *path2);
+int     linkat(int olddirfd, FAR const char *path1,
+               int newdirfd, FAR const char *path2, int flags);
 int     symlink(FAR const char *path1, FAR const char *path2);
+int     symlinkat(FAR const char *path1, int dirfd,
+                  FAR const char *path2);
 ssize_t readlink(FAR const char *path, FAR char *buf, size_t bufsize);
+ssize_t readlinkat(int dirfd, FAR const char *path, FAR char *buf,
+                   size_t bufsize);
 int     chown(FAR const char *path, uid_t owner, gid_t group);
 int     lchown(FAR const char *path, uid_t owner, gid_t group);
+int     fchownat(int dirfd, FAR const char *path, uid_t owner,
+                 gid_t group, int flags);
 
 /* Execution of programs from files */