git: 4bd01d6ae016 - main - fts: refactor to use fd-relative operations internally
Date: Mon, 03 Aug 2026 19:13:08 UTC
The branch main has been updated by asomers:
URL: https://cgit.FreeBSD.org/src/commit/?id=4bd01d6ae01632501b63438b8d9a401db9744a78
commit 4bd01d6ae01632501b63438b8d9a401db9744a78
Author: Jitendra Bhati <bhatijitendra2022@gmail.com>
AuthorDate: 2026-06-12 17:07:55 +0000
Commit: Alan Somers <asomers@FreeBSD.org>
CommitDate: 2026-08-03 19:12:28 +0000
fts: refactor to use fd-relative operations internally
Replace all _open() calls with _openat() in __fts_open(), fts_read(),
and fts_children(). Replace statfs() with _fstatfs().
Add fts_dirfd to struct _ftsent, set to the file descriptor of the
parent directory. Callers can use openat(ent->fts_dirfd, ent->fts_name,
...) to access files safely without relying on fts_accpath, which
enables programs in capability mode to open the files described by
_ftsent.
This is a preparatory change for fts_openat() which will allow callers
to provide a pre-opened directory fd, enabling fts(3) traversal inside
Capsicum capability mode.
Mirror all fts_open() changes to fts_open_b().
As a result of expanding _ftsend, publish new ELF symbol versions for
fts_openat and related functions.
Sponsored by: Google LLC (GSoC 2026)
Reviewed by: asomers
Pull Request: https://github.com/freebsd/freebsd-src/pull/2303
---
include/fts.h | 2 +
lib/libc/gen/Makefile.inc | 1 +
lib/libc/gen/Symbol.map | 18 +-
lib/libc/gen/fts-compat15.c | 1355 +++++++++++++++++++++++++++++++++++++++++++
lib/libc/gen/fts-compat15.h | 97 ++++
lib/libc/gen/fts.3 | 18 +-
lib/libc/gen/fts.c | 49 +-
7 files changed, 1519 insertions(+), 21 deletions(-)
diff --git a/include/fts.h b/include/fts.h
index 479905bda463..0308b8ff880b 100644
--- a/include/fts.h
+++ b/include/fts.h
@@ -92,6 +92,8 @@ struct _ftsent {
char *fts_path; /* root path */
int fts_errno; /* errno for this node */
int fts_symfd; /* fd for symlink */
+ int fts_dirfd; /* fd for parent directory */
+ int __fts_reserved[3]; /* reserved for future use */
__size_t fts_pathlen; /* strlen(fts_path) */
__size_t fts_namelen; /* strlen(fts_name) */
diff --git a/lib/libc/gen/Makefile.inc b/lib/libc/gen/Makefile.inc
index 18a68902f50a..582e519df0e5 100644
--- a/lib/libc/gen/Makefile.inc
+++ b/lib/libc/gen/Makefile.inc
@@ -63,6 +63,7 @@ SRCS+= \
fts.c \
fts-compat.c \
fts-compat11.c \
+ fts-compat15.c \
ftw.c \
ftw-compat11.c \
getbootfile.c \
diff --git a/lib/libc/gen/Symbol.map b/lib/libc/gen/Symbol.map
index 4d22251f7ec5..8c4853737064 100644
--- a/lib/libc/gen/Symbol.map
+++ b/lib/libc/gen/Symbol.map
@@ -402,14 +402,6 @@ FBSD_1.5 {
devname;
devname_r;
dirname;
- fts_children;
- fts_close;
- fts_get_clientptr;
- fts_get_stream;
- fts_open;
- fts_read;
- fts_set;
- fts_set_clientptr;
ftw;
getentropy;
getmntinfo;
@@ -459,7 +451,6 @@ FBSD_1.8 {
execvpe;
fdscandir;
fdscandir_b;
- fts_open_b;
glob_b;
initgroups;
inotify_add_watch;
@@ -476,6 +467,15 @@ FBSD_1.8 {
FBSD_1.9 {
freadlink;
+ fts_children;
+ fts_close;
+ fts_get_clientptr;
+ fts_get_stream;
+ fts_open;
+ fts_open_b;
+ fts_read;
+ fts_set;
+ fts_set_clientptr;
posix_spawn_file_actions_addchdir;
posix_spawn_file_actions_addfchdir;
posix_spawnattr_getexecfd_np;
diff --git a/lib/libc/gen/fts-compat15.c b/lib/libc/gen/fts-compat15.c
new file mode 100644
index 000000000000..c041a2380f3c
--- /dev/null
+++ b/lib/libc/gen/fts-compat15.c
@@ -0,0 +1,1355 @@
+/*
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1990, 1993, 1994
+ * The Regents of the University of California. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+/*
+ * Compatibility shim for FBSD_1.5 fts(3) ABI.
+ * This file provides the old fts functions for binaries compiled
+ * against FreeBSD 15.x and earlier without fts_dirfd in FTSENT15.
+ */
+
+#include "namespace.h"
+#include <sys/param.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include "fts-compat15.h"
+#include <fts.h>
+#include <stdalign.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "un-namespace.h"
+
+#include "gen-private.h"
+
+#ifdef __BLOCKS__
+#include <Block.h>
+#else
+#include "block_abi.h"
+typedef DECLARE_BLOCK(int, fts_block,
+ const FTSENT15 * const *, const FTSENT15 * const *);
+void qsort_b(void *, size_t, size_t, fts_block);
+#endif /* __BLOCKS__ */
+/* only present if linked with blocks runtime */
+void *_Block_copy(const void *) __weak_symbol;
+void _Block_release(const void *) __weak_symbol;
+extern void *_NSConcreteGlobalBlock[] __weak_symbol;
+
+static FTSENT15 *fts_alloc(FTS15 *, char *, size_t);
+static FTSENT15 *fts_build(FTS15 *, int);
+static void fts_lfree(FTSENT15 *);
+static void fts_load(FTS15 *, FTSENT15 *);
+static size_t fts_maxarglen(char * const *);
+static void fts_padjust(FTS15 *, FTSENT15 *);
+static int fts_palloc(FTS15 *, size_t);
+static FTSENT15 *fts_sort(FTS15 *, FTSENT15 *, size_t);
+static int fts_stat(FTS15 *, FTSENT15 *, int, int);
+static int fts_safe_changedir(FTS15 *, FTSENT15 *, int, char *);
+static int fts_ufslinks(FTS15 *, const FTSENT15 *);
+
+#define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2])))
+
+#define CLR(opt) (sp->fts_options &= ~(opt))
+#define ISSET(opt) (sp->fts_options & (opt))
+#define SET(opt) (sp->fts_options |= (opt))
+
+#define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd))
+
+/* fts_build flags */
+#define BCHILD 1 /* freebsd15_fts_children */
+#define BNAMES 2 /* freebsd15_fts_children, names only */
+#define BREAD 3 /* freebsd15_fts_read */
+
+/*
+ * Internal representation of an FTS15, including extra implementation
+ * details. The FTS15 returned from freebsd15_fts_open points to this structure's
+ * ftsp_fts member (and can be cast to an _fts_private as required)
+ */
+struct _fts_private {
+ FTS15 ftsp_fts;
+ struct statfs ftsp_statfs;
+ dev_t ftsp_dev;
+ int ftsp_linksreliable;
+};
+
+/*
+ * The "FTS_NOSTAT" option can avoid a lot of calls to stat(2) if it
+ * knows that a directory could not possibly have subdirectories. This
+ * is decided by looking at the link count: a subdirectory would
+ * increment its parent's link count by virtue of its own ".." entry.
+ * This assumption only holds for UFS-like filesystems that implement
+ * links and directories this way, so we must punt for others.
+ */
+static const char *ufslike_filesystems[] = {
+ "ufs",
+ "zfs",
+ "nfs",
+ "ext2fs",
+ 0
+};
+
+/*
+ * POSIX provides nlink_t but unfortunately not NLINK_MAX.
+ */
+#define NLINK_MAX \
+ _Generic((nlink_t)0, \
+ int16_t: INT16_MAX, \
+ uint16_t: UINT16_MAX, \
+ int32_t: INT32_MAX, \
+ uint32_t: UINT32_MAX, \
+ int64_t: INT64_MAX, \
+ uint64_t: UINT64_MAX, \
+ default: 0)
+
+static FTS15 *
+__fts_open(FTS15 *sp, char * const *argv)
+{
+ FTSENT15 *p, *root;
+ FTSENT15 *parent, *tmp;
+ size_t len, nitems;
+
+ /* Logical walks turn on NOCHDIR; symbolic links are too hard. */
+ if (ISSET(FTS_LOGICAL))
+ SET(FTS_NOCHDIR);
+
+ /* NOSTAT_TYPE implies NOSTAT */
+ if (ISSET(FTS_NOSTAT_TYPE))
+ SET(FTS_NOSTAT);
+
+ /*
+ * Start out with 1K of path space, and enough, in any case,
+ * to hold the user's paths.
+ */
+ if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN)))
+ goto mem1;
+
+ /* Allocate/initialize root's parent. */
+ if ((parent = fts_alloc(sp, "", 0)) == NULL)
+ goto mem2;
+ parent->fts_level = FTS_ROOTPARENTLEVEL;
+
+ /* Shush, GCC. */
+ tmp = NULL;
+
+ /* Allocate/initialize root(s). */
+ for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) {
+ len = strlen(*argv);
+
+ p = fts_alloc(sp, *argv, len);
+ p->fts_level = FTS_ROOTLEVEL;
+ p->fts_parent = parent;
+ p->fts_accpath = p->fts_name;
+ p->fts_info = fts_stat(sp, p,
+ ISSET(FTS_COMFOLLOWDIR) ? -1 : ISSET(FTS_COMFOLLOW),
+ -1);
+
+ /* Command-line "." and ".." are real directories. */
+ if (p->fts_info == FTS_DOT)
+ p->fts_info = FTS_D;
+
+ /*
+ * If comparison routine supplied, traverse in sorted
+ * order; otherwise traverse in the order specified.
+ */
+ if (sp->fts_compar) {
+ p->fts_link = root;
+ root = p;
+ } else {
+ p->fts_link = NULL;
+ if (root == NULL)
+ tmp = root = p;
+ else {
+ tmp->fts_link = p;
+ tmp = p;
+ }
+ }
+ }
+ if (sp->fts_compar && nitems > 1)
+ root = fts_sort(sp, root, nitems);
+
+ /*
+ * Allocate a dummy pointer and make freebsd15_fts_read think that we've just
+ * finished the node before the root(s); set p->fts_info to FTS_INIT
+ * so that everything about the "current" node is ignored.
+ */
+ if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL)
+ goto mem3;
+ sp->fts_cur->fts_link = root;
+ sp->fts_cur->fts_info = FTS_INIT;
+
+ /*
+ * If using chdir(2), grab a file descriptor pointing to dot to ensure
+ * that we can get back here; this could be avoided for some paths,
+ * but almost certainly not worth the effort. Slashes, symbolic links,
+ * and ".." are all fairly nasty problems. Note, if we can't get the
+ * descriptor we run anyway, just more slowly.
+ */
+ if (!ISSET(FTS_NOCHDIR) &&
+ (sp->fts_rfd = _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0)
+ SET(FTS_NOCHDIR);
+
+ return (sp);
+
+mem3: fts_lfree(root);
+ free(parent);
+mem2: free(sp->fts_path);
+mem1: free(sp);
+ return (NULL);
+}
+
+FTS15 *
+freebsd15_fts_open(char * const *argv, int options,
+ int (*compar)(const FTSENT15 * const *, const FTSENT15 * const *))
+{
+ struct _fts_private *priv;
+ FTS15 *sp;
+
+ /* Options check. */
+ if (options & ~FTS_OPTIONMASK) {
+ errno = EINVAL;
+ return (NULL);
+ }
+
+ /* freebsd15_fts_open() requires at least one path */
+ if (*argv == NULL) {
+ errno = EINVAL;
+ return (NULL);
+ }
+
+ /* Allocate/initialize the stream. */
+ if ((priv = calloc(1, sizeof(*priv))) == NULL)
+ return (NULL);
+ sp = &priv->ftsp_fts;
+ sp->fts_compar = (int (*)(const FTSENT15 * const *,
+ const FTSENT15 * const *))compar;
+ sp->fts_options = options;
+ return ((FTS15 *)__fts_open(sp, argv));
+}
+
+#ifdef __BLOCKS__
+FTS15 *
+freebsd15_fts_open_b(char * const *argv, int options,
+ int (^compar)(const FTSENT15 * const *, const FTSENT15 * const *))
+#else
+FTS15 *
+freebsd15_fts_open_b(char * const *argv, int options, fts_block compar)
+#endif /* __BLOCKS__ */
+{
+ struct _fts_private *priv;
+ FTS15 *sp;
+
+ /* No blocks, no problems. */
+ if (compar == NULL)
+ return (freebsd15_fts_open(argv, options, NULL));
+
+ /* Avoid segfault if blocks runtime is missing. */
+ if (_Block_copy == NULL) {
+ errno = ENOSYS;
+ return (NULL);
+ }
+
+ /* Options check. */
+ if (options & ~FTS_OPTIONMASK) {
+ errno = EINVAL;
+ return (NULL);
+ }
+
+ /* freebsd15_fts_open() requires at least one path */
+ if (*argv == NULL) {
+ errno = EINVAL;
+ return (NULL);
+ }
+
+ /* Allocate/initialize the stream. */
+ if ((priv = calloc(1, sizeof(*priv))) == NULL)
+ return (NULL);
+ sp = &priv->ftsp_fts;
+#ifdef __BLOCKS__
+ compar = Block_copy(compar);
+#else
+ if (compar->isa != &_NSConcreteGlobalBlock)
+ compar = _Block_copy(compar);
+#endif /* __BLOCKS__ */
+ if (compar == NULL) {
+ free(priv);
+ return (NULL);
+ }
+ sp->fts_compar_b = compar;
+ sp->fts_options = options | FTS_COMPAR_B;
+
+ if ((sp = __fts_open(sp, argv)) == NULL) {
+#ifdef __BLOCKS__
+ Block_release(compar);
+#else
+ if (compar->isa != &_NSConcreteGlobalBlock)
+ _Block_release(compar);
+#endif /* __BLOCKS__ */
+ }
+ return (sp);
+}
+
+static void
+fts_load(FTS15 *sp, FTSENT15 *p)
+{
+ size_t len;
+ char *cp;
+
+ /*
+ * Load the stream structure for the next traversal. Since we don't
+ * actually enter the directory until after the preorder visit, set
+ * the fts_accpath field specially so the chdir gets done to the right
+ * place and the user can access the first node. From freebsd15_fts_open it's
+ * known that the path will fit.
+ */
+ len = p->fts_pathlen = p->fts_namelen;
+ memmove(sp->fts_path, p->fts_name, len + 1);
+ if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) {
+ len = strlen(++cp);
+ memmove(p->fts_name, cp, len + 1);
+ p->fts_namelen = len;
+ }
+ p->fts_accpath = p->fts_path = sp->fts_path;
+ sp->fts_dev = p->fts_dev;
+}
+
+int
+freebsd15_fts_close(FTS15 *sp)
+{
+ FTSENT15 *freep, *p;
+ int saved_errno;
+
+ /*
+ * This still works if we haven't read anything -- the dummy structure
+ * points to the root list, so we step through to the end of the root
+ * list which has a valid parent pointer.
+ */
+ if (sp->fts_cur) {
+ for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) {
+ freep = p;
+ p = p->fts_link != NULL ? p->fts_link : p->fts_parent;
+ free(freep);
+ }
+ free(p);
+ }
+
+ /* Free up child linked list, sort array, path buffer. */
+ if (sp->fts_child)
+ fts_lfree(sp->fts_child);
+ if (sp->fts_array)
+ free(sp->fts_array);
+ free(sp->fts_path);
+
+ /* Free up any block pointer. */
+ if (ISSET(FTS_COMPAR_B) && sp->fts_compar_b != NULL) {
+#ifdef __BLOCKS__
+ Block_release(sp->fts_compar_b);
+#else
+ if (((fts_block)(sp->fts_compar_b))->isa !=
+ &_NSConcreteGlobalBlock)
+ _Block_release(sp->fts_compar_b);
+#endif /* __BLOCKS__ */
+ }
+
+ /* Return to original directory, save errno if necessary. */
+ if (!ISSET(FTS_NOCHDIR)) {
+ saved_errno = fchdir(sp->fts_rfd) ? errno : 0;
+ (void)_close(sp->fts_rfd);
+
+ /* Set errno and return. */
+ if (saved_errno != 0) {
+ /* Free up the stream pointer. */
+ free(sp);
+ errno = saved_errno;
+ return (-1);
+ }
+ }
+
+ /* Free up the stream pointer. */
+ free(sp);
+ return (0);
+}
+
+/*
+ * Special case of "/" at the end of the path so that slashes aren't
+ * appended which would cause paths to be written as "....//foo".
+ */
+#define NAPPEND(p) \
+ (p->fts_path[p->fts_pathlen - 1] == '/' \
+ ? p->fts_pathlen - 1 : p->fts_pathlen)
+
+FTSENT15 *
+freebsd15_fts_read(FTS15 *sp)
+{
+ FTSENT15 *p, *tmp;
+ int instr;
+ char *t;
+ int saved_errno;
+
+ /* If finished or unrecoverable error, return NULL. */
+ if (sp->fts_cur == NULL || ISSET(FTS_STOP))
+ return (NULL);
+
+ /* Set current node pointer. */
+ p = sp->fts_cur;
+
+ /* Save and zero out user instructions. */
+ instr = p->fts_instr;
+ p->fts_instr = FTS_NOINSTR;
+
+ /* Any type of file may be re-visited; re-stat and re-turn. */
+ if (instr == FTS_AGAIN) {
+ p->fts_info = fts_stat(sp, p, 0, -1);
+ return (p);
+ }
+
+ /*
+ * Following a symlink -- SLNONE test allows application to see
+ * SLNONE and recover. If indirecting through a symlink, have
+ * keep a pointer to current location. If unable to get that
+ * pointer, follow fails.
+ */
+ if (instr == FTS_FOLLOW &&
+ (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) {
+ p->fts_info = fts_stat(sp, p, 1, -1);
+ if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
+ if ((p->fts_symfd = _open(".", O_RDONLY | O_CLOEXEC,
+ 0)) < 0) {
+ p->fts_errno = errno;
+ p->fts_info = FTS_ERR;
+ } else
+ p->fts_flags |= FTS_SYMFOLLOW;
+ }
+ return (p);
+ }
+
+ /* Directory in pre-order. */
+ if (p->fts_info == FTS_D) {
+ /* If skipped or crossed mount point, do post-order visit. */
+ if (instr == FTS_SKIP ||
+ (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) {
+ if (p->fts_flags & FTS_SYMFOLLOW)
+ (void)_close(p->fts_symfd);
+ if (sp->fts_child) {
+ fts_lfree(sp->fts_child);
+ sp->fts_child = NULL;
+ }
+ p->fts_info = FTS_DP;
+ return (p);
+ }
+
+ /* Rebuild if only read the names and now traversing. */
+ if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) {
+ CLR(FTS_NAMEONLY);
+ fts_lfree(sp->fts_child);
+ sp->fts_child = NULL;
+ }
+
+ /*
+ * Cd to the subdirectory.
+ *
+ * If have already read and now fail to chdir, whack the list
+ * to make the names come out right, and set the parent errno
+ * so the application will eventually get an error condition.
+ * Set the FTS_DONTCHDIR flag so that when we logically change
+ * directories back to the parent we don't do a chdir.
+ *
+ * If haven't read do so. If the read fails, fts_build sets
+ * FTS_STOP or the fts_info field of the node.
+ */
+ if (sp->fts_child != NULL) {
+ if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) {
+ p->fts_errno = errno;
+ p->fts_flags |= FTS_DONTCHDIR;
+ for (p = sp->fts_child; p != NULL;
+ p = p->fts_link)
+ p->fts_accpath =
+ p->fts_parent->fts_accpath;
+ }
+ } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) {
+ if (ISSET(FTS_STOP))
+ return (NULL);
+ return (p);
+ }
+ p = sp->fts_child;
+ sp->fts_child = NULL;
+ goto name;
+ }
+
+ /* Move to the next node on this level. */
+next: tmp = p;
+ if ((p = p->fts_link) != NULL) {
+ /*
+ * If reached the top, return to the original directory (or
+ * the root of the tree), and load the paths for the next root.
+ */
+ if (p->fts_level == FTS_ROOTLEVEL) {
+ if (FCHDIR(sp, sp->fts_rfd)) {
+ SET(FTS_STOP);
+ return (NULL);
+ }
+ free(tmp);
+ fts_load(sp, p);
+ return (sp->fts_cur = p);
+ }
+
+ /*
+ * User may have called freebsd15_fts_set on the node. If skipped,
+ * ignore. If followed, get a file descriptor so we can
+ * get back if necessary.
+ */
+ if (p->fts_instr == FTS_SKIP) {
+ free(tmp);
+ goto next;
+ }
+ if (p->fts_instr == FTS_FOLLOW) {
+ p->fts_info = fts_stat(sp, p, 1, -1);
+ if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
+ if ((p->fts_symfd =
+ _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) {
+ p->fts_errno = errno;
+ p->fts_info = FTS_ERR;
+ } else
+ p->fts_flags |= FTS_SYMFOLLOW;
+ }
+ p->fts_instr = FTS_NOINSTR;
+ }
+
+ free(tmp);
+
+name: t = sp->fts_path + NAPPEND(p->fts_parent);
+ *t++ = '/';
+ memmove(t, p->fts_name, p->fts_namelen + 1);
+ return (sp->fts_cur = p);
+ }
+
+ /* Move up to the parent node. */
+ p = tmp->fts_parent;
+
+ if (p->fts_level == FTS_ROOTPARENTLEVEL) {
+ /*
+ * Done; free everything up and set errno to 0 so the user
+ * can distinguish between error and EOF.
+ */
+ free(tmp);
+ free(p);
+ errno = 0;
+ return (sp->fts_cur = NULL);
+ }
+
+ /* NUL terminate the pathname. */
+ sp->fts_path[p->fts_pathlen] = '\0';
+
+ /*
+ * Return to the parent directory. If at a root node or came through
+ * a symlink, go back through the file descriptor. Otherwise, cd up
+ * one directory.
+ */
+ if (p->fts_level == FTS_ROOTLEVEL) {
+ if (FCHDIR(sp, sp->fts_rfd)) {
+ SET(FTS_STOP);
+ return (NULL);
+ }
+ } else if (p->fts_flags & FTS_SYMFOLLOW) {
+ if (FCHDIR(sp, p->fts_symfd)) {
+ saved_errno = errno;
+ (void)_close(p->fts_symfd);
+ errno = saved_errno;
+ SET(FTS_STOP);
+ return (NULL);
+ }
+ (void)_close(p->fts_symfd);
+ } else if (!(p->fts_flags & FTS_DONTCHDIR) &&
+ fts_safe_changedir(sp, p->fts_parent, -1, "..")) {
+ SET(FTS_STOP);
+ return (NULL);
+ }
+ free(tmp);
+ p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
+ return (sp->fts_cur = p);
+}
+
+/*
+ * Fts_set takes the stream as an argument although it's not used in this
+ * implementation; it would be necessary if anyone wanted to add global
+ * semantics to fts using freebsd15_fts_set. An error return is allowed for similar
+ * reasons.
+ */
+/* ARGSUSED */
+int
+freebsd15_fts_set(FTS15 *sp, FTSENT15 *p, int instr)
+{
+ if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW &&
+ instr != FTS_NOINSTR && instr != FTS_SKIP) {
+ errno = EINVAL;
+ return (1);
+ }
+ p->fts_instr = instr;
+ return (0);
+}
+
+FTSENT15 *
+freebsd15_fts_children(FTS15 *sp, int instr)
+{
+ FTSENT15 *p;
+ int fd, rc, serrno;
+
+ if (instr != 0 && instr != FTS_NAMEONLY) {
+ errno = EINVAL;
+ return (NULL);
+ }
+
+ /* Set current node pointer. */
+ p = sp->fts_cur;
+
+ /*
+ * Errno set to 0 so user can distinguish empty directory from
+ * an error.
+ */
+ errno = 0;
+
+ /* Fatal errors stop here. */
+ if (ISSET(FTS_STOP))
+ return (NULL);
+
+ /* Return logical hierarchy of user's arguments. */
+ if (p->fts_info == FTS_INIT)
+ return (p->fts_link);
+
+ /*
+ * If not a directory being visited in pre-order, stop here. Could
+ * allow FTS_DNR, assuming the user has fixed the problem, but the
+ * same effect is available with FTS_AGAIN.
+ */
+ if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */)
+ return (NULL);
+
+ /* Free up any previous child list. */
+ if (sp->fts_child != NULL)
+ fts_lfree(sp->fts_child);
+
+ if (instr == FTS_NAMEONLY) {
+ SET(FTS_NAMEONLY);
+ instr = BNAMES;
+ } else
+ instr = BCHILD;
+
+ /*
+ * If using chdir on a relative path and called BEFORE freebsd15_fts_read does
+ * its chdir to the root of a traversal, we can lose -- we need to
+ * chdir into the subdirectory, and we don't know where the current
+ * directory is, so we can't get back so that the upcoming chdir by
+ * freebsd15_fts_read will work.
+ */
+ if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' ||
+ ISSET(FTS_NOCHDIR))
+ return (sp->fts_child = fts_build(sp, instr));
+
+ if ((fd = _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0)
+ return (NULL);
+ sp->fts_child = fts_build(sp, instr);
+ serrno = (sp->fts_child == NULL) ? errno : 0;
+ rc = fchdir(fd);
+ if (rc < 0 && serrno == 0)
+ serrno = errno;
+ (void)_close(fd);
+ errno = serrno;
+ if (rc < 0)
+ return (NULL);
+ return (sp->fts_child);
+}
+
+#ifndef freebsd15_fts_get_clientptr
+#error "freebsd15_fts_get_clientptr not defined"
+#endif
+
+void *
+(freebsd15_fts_get_clientptr)(FTS15 *sp)
+{
+ return (freebsd15_fts_get_clientptr(sp));
+}
+
+#ifndef freebsd15_fts_get_stream
+#error "freebsd15_fts_get_stream not defined"
+#endif
+
+FTS15 *
+(freebsd15_fts_get_stream)(FTSENT15 *p)
+{
+ return (freebsd15_fts_get_stream(p));
+}
+
+void
+freebsd15_fts_set_clientptr(FTS15 *sp, void *clientptr)
+{
+ sp->fts_clientptr = clientptr;
+}
+
+static struct dirent *
+fts_safe_readdir(DIR *dirp, int *readdir_errno)
+{
+ struct dirent *ret;
+
+ errno = 0;
+ if (!dirp)
+ return (NULL);
+ ret = readdir(dirp);
+ *readdir_errno = errno;
+ return (ret);
+}
+
+/*
+ * 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 freebsd15_fts_children
+ * and freebsd15_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 FTSENT15 *
+fts_build(FTS15 *sp, int type)
+{
+ struct dirent *dp;
+ FTSENT15 *p, *head;
+ FTSENT15 *cur, *tail;
+ DIR *dirp;
+ void *oldaddr;
+ char *cp;
+ int cderrno, descend, oflag, saved_errno, nostat, doadjust,
+ readdir_errno;
+ long level;
+ int64_t 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 freebsd15_fts_read, set the fts_info field.
+ */
+ if (ISSET(FTS_WHITEOUT))
+ oflag = DTF_NODUP;
+ else
+ oflag = DTF_HIDEW | DTF_NODUP;
+ if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) {
+ if (type == BREAD) {
+ cur->fts_info = FTS_DNR;
+ cur->fts_errno = errno;
+ }
+ return (NULL);
+ }
+
+ /*
+ * In the FTS_PHYSICAL | FTS_NOSTAT case, we want to avoid calling
+ * fstat() unnecessarily, but we still need to call it for
+ * subdirectories. The current directory's link count provides an
+ * upper bound on the number of subdirectories we may encounter
+ * (including . and .. in the FTS_SEEDOT case). We initialize
+ * nlinks to the current directory's link count, then decrement it
+ * every time we encounter a directory, so when we hit zero we can
+ * save some time by not calling fstat() on subsequent entries.
+ *
+ * If FTS_NOSTAT is not set, or the link count is less than two
+ * (which should not be possible) or equal to NLINK_MAX (which
+ * suggests that the actual value could be higher), or the current
+ * filesystem is not known to provide reliable link counts, we
+ * initialize nlinks to -1 and fstat() everything.
+ *
+ * In the rare case where we don't need to stat anything, even
+ * subdirectories, we initialize nlinks to 0 regardless of the
+ * actual link count.
+ *
+ * Note that we ignore the FTS_NOSTAT flag in the FTS_LOGICAL
+ * case, although we could choose to only stat symbolic links.
+ * Implementing this is left as an exercise for the reader.
+ */
+ if (type == BNAMES) {
+ nlinks = 0;
+ /* Be quiet about nostat, GCC. */
+ nostat = 0;
+ } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) {
+ if (cur->fts_nlink >= 2 && cur->fts_nlink < NLINK_MAX &&
+ cur->fts_nlink <= INT64_MAX && 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 freebsd15_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 freebsd15_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;
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