/*
* This is the tricky part -- do not casually change *anything* in here. The
* idea is to build the linked list of entries that are used by fts_children
* and fts_read. There are lots of special cases.
*
* The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is
* set and it's a physical walk (so that symbolic links can't be directories),
* we can do things quickly. First, if it's a 4.4BSD file system, the type
* of the file is in the directory entry. Otherwise, we assume that the number
* of subdirectories in a node is equal to the number of links to the parent.
* The former skips all stat calls. The latter skips stat calls in any leaf
* directories and for any files after the subdirectories in the directory have
* been found, cutting the stat calls by about 2/3.
*/
static FTSENT *
fts_build(FTS *sp, int type)
{
struct dirent *dp;
FTSENT *p, *head;
FTSENT *cur, *tail;
DIR *dirp;
void *oldaddr;
char *cp;
int cderrno, descend, oflag, saved_errno, nostat, doadjust;
long level;
long nlinks; /* has to be signed because -1 is a magic value */
size_t dnamlen, len, maxlen, nitems;
/* Set current node pointer. */
cur = sp->fts_cur;
/*
* Open the directory for reading. If this fails, we're done.
* If being called from fts_read, set the fts_info field.
*/
#ifdef FTS_WHITEOUT
if (ISSET(FTS_WHITEOUT))
oflag = DTF_NODUP | DTF_REWIND;
else
oflag = DTF_HIDEW | DTF_NODUP | DTF_REWIND;
#else
#define __opendir2(path, flag) opendir(path)
#endif
if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) {
if (type == BREAD) {
cur->fts_info = FTS_DNR;
cur->fts_errno = errno;
}
return (NULL);
}
/*
* Nlinks is the number of possible entries of type directory in the
* directory if we're cheating on stat calls, 0 if we're not doing
* any stat calls at all, -1 if we're doing stats on everything.
*/
if (type == BNAMES) {
nlinks = 0;
/* Be quiet about nostat, GCC. */
nostat = 0;
} else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) {
if (fts_ufslinks(sp, cur))
nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2);
else
nlinks = -1;
nostat = 1;
} else {
nlinks = -1;
nostat = 0;
}
#ifdef notdef
(void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink);
(void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n",
ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT));
#endif
/*
* If we're going to need to stat anything or we want to descend
* and stay in the directory, chdir. If this fails we keep going,
* but set a flag so we don't chdir after the post-order visit.
* We won't be able to stat anything, but we can still return the
* names themselves. Note, that since fts_read won't be able to
* chdir into the directory, it will have to return different path
* names than before, i.e. "a/b" instead of "b". Since the node
* has already been visited in pre-order, have to wait until the
* post-order visit to return the error. There is a special case
* here, if there was nothing to stat then it's not an error to
* not be able to stat. This is all fairly nasty. If a program
* needed sorted entries or stat information, they had better be
* checking FTS_NS on the returned nodes.
*/
cderrno = 0;
if (nlinks || type == BREAD) {
if (fts_safe_changedir(sp, cur, _dirfd(dirp), NULL)) {
if (nlinks && type == BREAD)
cur->fts_errno = errno;
cur->fts_flags |= FTS_DONTCHDIR;
descend = 0;
cderrno = errno;
} else
descend = 1;
} else
descend = 0;
/*
* Figure out the max file name length that can be stored in the
* current path -- the inner loop allocates more path as necessary.
* We really wouldn't have to do the maxlen calculations here, we
* could do them in fts_read before returning the path, but it's a
* lot easier here since the length is part of the dirent structure.
*
* If not changing directories set a pointer so that can just append
* each new name into the path.
*/
len = NAPPEND(cur);
if (ISSET(FTS_NOCHDIR)) {
cp = sp->fts_path + len;
*cp++ = '/';
} else {
/* GCC, you're too verbose. */
cp = NULL;
}
len++;
maxlen = sp->fts_pathlen - len;
level = cur->fts_level + 1;
/* Read the directory, attaching each entry to the `link' pointer. */
doadjust = 0;
for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) {
dnamlen = dp->d_namlen;
if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name))
continue;
if ((p = fts_alloc(sp, dp->d_name, dnamlen)) == NULL)
goto mem1;
if (dnamlen >= maxlen) { /* include space for NUL */
oldaddr = sp->fts_path;
if (fts_palloc(sp, dnamlen + len + 1)) {
/*
* No more memory for path or structures. Save
* errno, free up the current structure and the
* structures already allocated.
*/
mem1: saved_errno = errno;
if (p)
free(p);
fts_lfree(head);
(void)closedir(dirp);
cur->fts_info = FTS_ERR;
SET(FTS_STOP);
errno = saved_errno;
return (NULL);
}
/* Did realloc() change the pointer? */
if (oldaddr != sp->fts_path) {
doadjust = 1;
if (ISSET(FTS_NOCHDIR))
cp = sp->fts_path + len;
}
maxlen = sp->fts_pathlen - len;
}
p->fts_level = level;
p->fts_parent = sp->fts_cur;
p->fts_pathlen = len + dnamlen;
#ifdef FTS_WHITEOUT
if (dp->d_type == DT_WHT)
p->fts_flags |= FTS_ISW;
#endif
if (cderrno) {
if (nlinks) {
p->fts_info = FTS_NS;
p->fts_errno = cderrno;
} else
p->fts_info = FTS_NSOK;
p->fts_accpath = cur->fts_accpath;
} else if (nlinks == 0
#ifdef DT_DIR
|| (nostat &&
dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN)
#endif
) {
p->fts_accpath =
ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name;
p->fts_info = FTS_NSOK;
} else {
/* Build a file name for fts_stat to stat. */
if (ISSET(FTS_NOCHDIR)) {
p->fts_accpath = p->fts_path;
memmove(cp, p->fts_name, p->fts_namelen + 1);
p->fts_info = fts_stat(sp, p, 0, _dirfd(dirp));
} else {
p->fts_accpath = p->fts_name;
p->fts_info = fts_stat(sp, p, 0, -1);
}
/* Decrement link count if applicable. */
if (nlinks > 0 && (p->fts_info == FTS_D ||
p->fts_info == FTS_DC || p->fts_info == FTS_DOT))
--nlinks;
}
/* We walk in directory order so "ls -f" doesn't get upset. */
p->fts_link = NULL;
if (head == NULL)
head = tail = p;
else {
tail->fts_link = p;
tail = p;
}
++nitems;
}
if (dirp)
(void)closedir(dirp);
/*
* If realloc() changed the address of the path, adjust the
* addresses for the rest of the tree and the dir list.
*/
if (doadjust)
fts_padjust(sp, head);
/*
* If not changing directories, reset the path back to original
* state.
*/
if (ISSET(FTS_NOCHDIR))
sp->fts_path[cur->fts_pathlen] = '\0';
/*
* If descended after called from fts_children or after called from
* fts_read and nothing found, get back. At the root level we use
* the saved fd; if one of fts_open()'s arguments is a relative path
* to an empty directory, we wind up here with no other way back. If
* can't get back, we're done.
*/
if (descend && (type == BCHILD || !nitems) &&
(cur->fts_level == FTS_ROOTLEVEL ?
FCHDIR(sp, sp->fts_rfd) :
fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {
cur->fts_info = FTS_ERR;
SET(FTS_STOP);
return (NULL);
}
/* If didn't find anything, return NULL. */
if (!nitems) {
if (type == BREAD)
cur->fts_info = FTS_DP;
return (NULL);
}
/* Sort the entries. */
if (sp->fts_compar && nitems > 1)
head = fts_sort(sp, head, nitems);
return (head);
}
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);
}
