The branch main has been updated by asomers: URL: https://cgit.FreeBSD.org/src/commit/?id=4bd01d6ae01632501b63438b8d9a401db9744a78
commit 4bd01d6ae01632501b63438b8d9a401db9744a78 Author: Jitendra Bhati <[email protected]> AuthorDate: 2026-06-12 17:07:55 +0000 Commit: Alan Somers <[email protected]> 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; *** 790 LINES SKIPPED ***
