int openat(int dirfd,const char * pathname, int flags, mode_t mode)
{
_openat = (int (*)(int dirfd,const char * pathname, int flags, ...)) dlsym(RTLD_NEXT, "openat");
if(flags & O_CREAT)
{
return _openat(dirfd,pathname, flags | O_NOATIME, mode);
}
else
{
return _openat(dirfd,pathname, flags | O_NOATIME, 0);
}
}
/*
* For a directory at the top of a unionfs stack, the entire directory's
* contents are read and cached locally until the next call to rewinddir().
* For the fdopendir() case, the initial seek position must be preserved.
* For rewinddir(), the full directory should always be re-read from the
* beginning.
*
* If an error occurs, the existing buffer and state of 'dirp' is left
* unchanged.
*/
bool
_filldir(DIR *dirp, bool use_current_pos)
{
struct dirent **dpv;
char *buf, *ddptr, *ddeptr;
off_t pos;
int fd2, incr, len, n, saved_errno, space;
len = 0;
space = 0;
buf = NULL;
ddptr = NULL;
/*
* Use the system page size if that is a multiple of DIRBLKSIZ.
* Hopefully this can be a big win someday by allowing page
* trades to user space to be done by _getdirentries().
*/
incr = getpagesize();
if ((incr % DIRBLKSIZ) != 0)
incr = DIRBLKSIZ;
/*
* The strategy here is to read all the directory
* entries into a buffer, sort the buffer, and
* remove duplicate entries by setting the inode
* number to zero.
*
* We reopen the directory because _getdirentries()
* on a MNT_UNION mount modifies the open directory,
* making it refer to the lower directory after the
* upper directory's entries are exhausted.
* This would otherwise break software that uses
* the directory descriptor for fchdir or *at
* functions, such as fts.c.
*/
if ((fd2 = _openat(dirp->dd_fd, ".", O_RDONLY | O_CLOEXEC)) == -1)
return (false);
if (use_current_pos) {
pos = lseek(dirp->dd_fd, 0, SEEK_CUR);
if (pos == -1 || lseek(fd2, pos, SEEK_SET) == -1) {
saved_errno = errno;
_close(fd2);
errno = saved_errno;
return (false);
}
}
do {
/*
* Always make at least DIRBLKSIZ bytes
* available to _getdirentries
*/
if (space < DIRBLKSIZ) {
space += incr;
len += incr;
buf = reallocf(buf, len);
if (buf == NULL) {
saved_errno = errno;
_close(fd2);
errno = saved_errno;
return (false);
}
ddptr = buf + (len - space);
}
n = _getdirentries(fd2, ddptr, space, &dirp->dd_seek);
if (n > 0) {
ddptr += n;
space -= n;
}
if (n < 0) {
saved_errno = errno;
_close(fd2);
errno = saved_errno;
return (false);
}
} while (n > 0);
_close(fd2);
ddeptr = ddptr;
/*
* There is now a buffer full of (possibly) duplicate
* names.
*/
dirp->dd_buf = buf;
/*
* Go round this loop twice...
*
* Scan through the buffer, counting entries.
* On the second pass, save pointers to each one.
* Then sort the pointers and remove duplicate names.
*/
for (dpv = 0;;) {
n = 0;
ddptr = buf;
while (ddptr < ddeptr) {
struct dirent *dp;
dp = (struct dirent *) ddptr;
if ((long)dp & 03L)
break;
if ((dp->d_reclen <= 0) ||
(dp->d_reclen > (ddeptr + 1 - ddptr)))
break;
ddptr += dp->d_reclen;
if (dp->d_fileno) {
if (dpv)
dpv[n] = dp;
n++;
}
}
if (dpv) {
struct dirent *xp;
/*
* This sort must be stable.
*/
mergesort(dpv, n, sizeof(*dpv), opendir_compar);
dpv[n] = NULL;
xp = NULL;
/*
* Scan through the buffer in sort order,
* zapping the inode number of any
* duplicate names.
*/
for (n = 0; dpv[n]; n++) {
struct dirent *dp = dpv[n];
if ((xp == NULL) ||
strcmp(dp->d_name, xp->d_name)) {
xp = dp;
} else {
dp->d_fileno = 0;
}
if (dp->d_type == DT_WHT &&
(dirp->dd_flags & DTF_HIDEW))
dp->d_fileno = 0;
}
free(dpv);
break;
} else {
dpv = malloc((n+1) * sizeof(struct dirent *));
if (dpv == NULL)
break;
}
}
dirp->dd_len = len;
dirp->dd_size = ddptr - dirp->dd_buf;
return (true);
}
char *
getcwd(char *pt, size_t size)
{
struct dirent *dp;
DIR *dir = NULL;
dev_t dev;
ino_t ino;
int first;
char *bpt;
struct stat s;
dev_t root_dev;
ino_t root_ino;
size_t ptsize;
int save_errno;
char *ept, c;
int fd;
/*
* If no buffer specified by the user, allocate one as necessary.
* If a buffer is specified, the size has to be non-zero. The path
* is built from the end of the buffer backwards.
*/
if (pt) {
ptsize = 0;
if (!size) {
errno = EINVAL;
return (NULL);
}
if (size == 1) {
errno = ERANGE;
return (NULL);
}
ept = pt + size;
} else {
if ((pt = malloc(ptsize = PATH_MAX)) == NULL)
return (NULL);
ept = pt + ptsize;
}
if (__getcwd(pt, ept - pt) == 0) {
if (*pt != '/') {
bpt = pt;
ept = pt + strlen(pt) - 1;
while (bpt < ept) {
c = *bpt;
*bpt++ = *ept;
*ept-- = c;
}
}
return (pt);
}
bpt = ept - 1;
*bpt = '\0';
/* Save root values, so know when to stop. */
if (stat("/", &s))
goto err;
root_dev = s.st_dev;
root_ino = s.st_ino;
errno = 0; /* XXX readdir has no error return. */
for (first = 1;; first = 0) {
/* Stat the current level. */
if (dir != NULL ? _fstat(_dirfd(dir), &s) : lstat(".", &s))
goto err;
/* Save current node values. */
ino = s.st_ino;
dev = s.st_dev;
/* Check for reaching root. */
if (root_dev == dev && root_ino == ino) {
*--bpt = '/';
/*
* It's unclear that it's a requirement to copy the
* path to the beginning of the buffer, but it's always
* been that way and stuff would probably break.
*/
bcopy(bpt, pt, ept - bpt);
if (dir)
(void) closedir(dir);
return (pt);
}
/* Open and stat parent directory. */
fd = _openat(dir != NULL ? _dirfd(dir) : AT_FDCWD,
"..", O_RDONLY | O_CLOEXEC);
if (fd == -1)
goto err;
if (dir)
(void) closedir(dir);
if (!(dir = fdopendir(fd)) || _fstat(_dirfd(dir), &s)) {
_close(fd);
goto err;
}
/*
* If it's a mount point, have to stat each element because
* the inode number in the directory is for the entry in the
* parent directory, not the inode number of the mounted file.
*/
save_errno = 0;
if (s.st_dev == dev) {
for (;;) {
if (!(dp = readdir(dir)))
goto notfound;
if (dp->d_fileno == ino)
break;
}
} else
for (;;) {
if (!(dp = readdir(dir)))
goto notfound;
if (ISDOT(dp))
continue;
/* Save the first error for later. */
if (fstatat(_dirfd(dir), dp->d_name, &s,
AT_SYMLINK_NOFOLLOW)) {
if (!save_errno)
save_errno = errno;
errno = 0;
continue;
}
if (s.st_dev == dev && s.st_ino == ino)
break;
}
/*
* Check for length of the current name, preceding slash,
* leading slash.
*/
while (bpt - pt < dp->d_namlen + (first ? 1 : 2)) {
size_t len, off;
if (!ptsize) {
errno = ERANGE;
goto err;
}
off = bpt - pt;
len = ept - bpt;
if ((pt = reallocf(pt, ptsize *= 2)) == NULL)
goto err;
bpt = pt + off;
ept = pt + ptsize;
bcopy(bpt, ept - len, len);
bpt = ept - len;
}
if (!first)
*--bpt = '/';
bpt -= dp->d_namlen;
bcopy(dp->d_name, bpt, dp->d_namlen);
}
notfound:
/*
* If readdir set errno, use it, not any saved error; otherwise,
* didn't find the current directory in its parent directory, set
* errno to ENOENT.
*/
if (!errno)
errno = save_errno ? save_errno : ENOENT;
/* FALLTHROUGH */
err:
save_errno = errno;
if (ptsize)
free(pt);
if (dir)
(void) closedir(dir);
errno = save_errno;
return (NULL);
}
