/* File tree walker functions. Copyright (C) 1996-2016 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 1996. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see . */ #ifdef HAVE_CONFIG_H # include #endif #if __GNUC__ # define alloca __builtin_alloca #else # if HAVE_ALLOCA_H # include # else # ifdef _AIX # pragma alloca # else char *alloca (); # endif # endif #endif #ifdef _LIBC # include # define NAMLEN(dirent) _D_EXACT_NAMLEN (dirent) #else # if HAVE_DIRENT_H # include # define NAMLEN(dirent) strlen ((dirent)->d_name) # else # define dirent direct # define NAMLEN(dirent) (dirent)->d_namlen # if HAVE_SYS_NDIR_H # include # endif # if HAVE_SYS_DIR_H # include # endif # if HAVE_NDIR_H # include # endif # endif #endif #include #include #include #include #include #include #include #include #include #include #ifdef _LIBC # include #else # include #endif #if ! _LIBC && !HAVE_DECL_STPCPY && !defined stpcpy char *stpcpy (); #endif #if ! _LIBC && ! defined HAVE_MEMPCPY && ! defined mempcpy /* Be CAREFUL that there are no side effects in N. */ # define mempcpy(D, S, N) ((void *) ((char *) memcpy (D, S, N) + (N))) #endif /* #define NDEBUG 1 */ #include #ifndef _LIBC # undef __chdir # define __chdir chdir # undef __closedir # define __closedir closedir # undef __fchdir # define __fchdir fchdir # undef __getcwd # define __getcwd(P, N) xgetcwd () extern char *xgetcwd (void); # undef __mempcpy # define __mempcpy mempcpy # undef __opendir # define __opendir opendir # undef __readdir64 # define __readdir64 readdir # undef __stpcpy # define __stpcpy stpcpy # undef __tdestroy # define __tdestroy tdestroy # undef __tfind # define __tfind tfind # undef __tsearch # define __tsearch tsearch # undef internal_function # define internal_function /* empty */ # undef dirent64 # define dirent64 dirent # undef MAX # define MAX(a, b) ((a) > (b) ? (a) : (b)) #endif /* Arrange to make lstat calls go through the wrapper function on systems with an lstat function that does not dereference symlinks that are specified with a trailing slash. */ #if ! _LIBC && ! LSTAT_FOLLOWS_SLASHED_SYMLINK int rpl_lstat (const char *, struct stat *); # undef lstat # define lstat(Name, Stat_buf) rpl_lstat(Name, Stat_buf) #endif #ifndef __set_errno # define __set_errno(Val) errno = (Val) #endif /* Support for the LFS API version. */ #ifndef FTW_NAME # define FTW_NAME ftw # define NFTW_NAME nftw # define NFTW_OLD_NAME __old_nftw # define NFTW_NEW_NAME __new_nftw # define INO_T ino_t # define STAT stat # ifdef _LIBC # define LXSTAT __lxstat # define XSTAT __xstat # define FXSTATAT __fxstatat # else # define LXSTAT(V,f,sb) lstat (f,sb) # define XSTAT(V,f,sb) stat (f,sb) # define FXSTATAT(V,d,f,sb,m) fstatat (d, f, sb, m) # endif # define FTW_FUNC_T __ftw_func_t # define NFTW_FUNC_T __nftw_func_t #endif /* We define PATH_MAX if the system does not provide a definition. This does not artificially limit any operation. PATH_MAX is simply used as a guesstimate for the expected maximal path length. Buffers will be enlarged if necessary. */ #ifndef PATH_MAX # define PATH_MAX 1024 #endif struct dir_data { DIR *stream; int streamfd; char *content; }; struct known_object { dev_t dev; INO_T ino; }; struct ftw_data { /* Array with pointers to open directory streams. */ struct dir_data **dirstreams; size_t actdir; size_t maxdir; /* Buffer containing name of currently processed object. */ char *dirbuf; size_t dirbufsize; /* Passed as fourth argument to `nftw' callback. The `base' member tracks the content of the `dirbuf'. */ struct FTW ftw; /* Flags passed to `nftw' function. 0 for `ftw'. */ int flags; /* Conversion array for flag values. It is the identity mapping for `nftw' calls, otherwise it maps the values to those known by `ftw'. */ const int *cvt_arr; /* Callback function. We always use the `nftw' form. */ NFTW_FUNC_T func; /* Device of starting point. Needed for FTW_MOUNT. */ dev_t dev; /* Data structure for keeping fingerprints of already processed object. This is needed when not using FTW_PHYS. */ void *known_objects; }; /* Internally we use the FTW_* constants used for `nftw'. When invoked as `ftw', map each flag to the subset of values used by `ftw'. */ static const int nftw_arr[] = { FTW_F, FTW_D, FTW_DNR, FTW_NS, FTW_SL, FTW_DP, FTW_SLN }; static const int ftw_arr[] = { FTW_F, FTW_D, FTW_DNR, FTW_NS, FTW_F, FTW_D, FTW_NS }; /* Forward declarations of local functions. */ static int ftw_dir (struct ftw_data *data, struct STAT *st, struct dir_data *old_dir) internal_function; static int object_compare (const void *p1, const void *p2) { /* We don't need a sophisticated and useful comparison. We are only interested in equality. However, we must be careful not to accidentally compare `holes' in the structure. */ const struct known_object *kp1 = p1, *kp2 = p2; int cmp1; cmp1 = (kp1->ino > kp2->ino) - (kp1->ino < kp2->ino); if (cmp1 != 0) return cmp1; return (kp1->dev > kp2->dev) - (kp1->dev < kp2->dev); } static int add_object (struct ftw_data *data, struct STAT *st) { struct known_object *newp = malloc (sizeof (struct known_object)); if (newp == NULL) return -1; newp->dev = st->st_dev; newp->ino = st->st_ino; return __tsearch (newp, &data->known_objects, object_compare) ? 0 : -1; } static inline int find_object (struct ftw_data *data, struct STAT *st) { struct known_object obj; obj.dev = st->st_dev; obj.ino = st->st_ino; return __tfind (&obj, &data->known_objects, object_compare) != NULL; } static inline int __attribute ((always_inline)) open_dir_stream (int *dfdp, struct ftw_data *data, struct dir_data *dirp) { int result = 0; if (data->dirstreams[data->actdir] != NULL) { /* Oh, oh. We must close this stream. Get all remaining entries and store them as a list in the `content' member of the `struct dir_data' variable. */ size_t bufsize = 1024; char *buf = malloc (bufsize); if (buf == NULL) result = -1; else { DIR *st = data->dirstreams[data->actdir]->stream; struct dirent64 *d; size_t actsize = 0; while ((d = __readdir64 (st)) != NULL) { size_t this_len = NAMLEN (d); if (actsize + this_len + 2 >= bufsize) { char *newp; bufsize += MAX (1024, 2 * this_len); newp = (char *) realloc (buf, bufsize); if (newp == NULL) { /* No more memory. */ int save_err = errno; free (buf); __set_errno (save_err); return -1; } buf = newp; } *((char *) __mempcpy (buf + actsize, d->d_name, this_len)) = '\0'; actsize += this_len + 1; } /* Terminate the list with an additional NUL byte. */ buf[actsize++] = '\0'; /* Shrink the buffer to what we actually need. */ data->dirstreams[data->actdir]->content = realloc (buf, actsize); if (data->dirstreams[data->actdir]->content == NULL) { int save_err = errno; free (buf); __set_errno (save_err); result = -1; } else { __closedir (st); data->dirstreams[data->actdir]->stream = NULL; data->dirstreams[data->actdir]->streamfd = -1; data->dirstreams[data->actdir] = NULL; } } } /* Open the new stream. */ if (result == 0) { assert (data->dirstreams[data->actdir] == NULL); if (dfdp != NULL && *dfdp != -1) { int fd = openat64_not_cancel_3 (*dfdp, data->dirbuf + data->ftw.base, O_RDONLY | O_DIRECTORY | O_NDELAY); dirp->stream = NULL; if (fd != -1 && (dirp->stream = __fdopendir (fd)) == NULL) close_not_cancel_no_status (fd); } else { const char *name; if (data->flags & FTW_CHDIR) { name = data->dirbuf + data->ftw.base; if (name[0] == '\0') name = "."; } else name = data->dirbuf; dirp->stream = __opendir (name); } if (dirp->stream == NULL) result = -1; else { dirp->streamfd = dirfd (dirp->stream); dirp->content = NULL; data->dirstreams[data->actdir] = dirp; if (++data->actdir == data->maxdir) data->actdir = 0; } } return result; } static int internal_function process_entry (struct ftw_data *data, struct dir_data *dir, const char *name, size_t namlen, int d_type) { struct STAT st; int result = 0; int flag = 0; size_t new_buflen; if (name[0] == '.' && (name[1] == '\0' || (name[1] == '.' && name[2] == '\0'))) /* Don't process the "." and ".." entries. */ return 0; new_buflen = data->ftw.base + namlen + 2; if (data->dirbufsize < new_buflen) { /* Enlarge the buffer. */ char *newp; data->dirbufsize = 2 * new_buflen; newp = (char *) realloc (data->dirbuf, data->dirbufsize); if (newp == NULL) return -1; data->dirbuf = newp; } *((char *) __mempcpy (data->dirbuf + data->ftw.base, name, namlen)) = '\0'; int statres; if (dir->streamfd != -1) statres = FXSTATAT (_STAT_VER, dir->streamfd, name, &st, (data->flags & FTW_PHYS) ? AT_SYMLINK_NOFOLLOW : 0); else { if ((data->flags & FTW_CHDIR) == 0) name = data->dirbuf; statres = ((data->flags & FTW_PHYS) ? LXSTAT (_STAT_VER, name, &st) : XSTAT (_STAT_VER, name, &st)); } if (statres < 0) { if (errno != EACCES && errno != ENOENT) result = -1; else if (data->flags & FTW_PHYS) flag = FTW_NS; else if (d_type == DT_LNK) flag = FTW_SLN; else { if (dir->streamfd != -1) statres = FXSTATAT (_STAT_VER, dir->streamfd, name, &st, AT_SYMLINK_NOFOLLOW); else statres = LXSTAT (_STAT_VER, name, &st); if (statres == 0 && S_ISLNK (st.st_mode)) flag = FTW_SLN; else flag = FTW_NS; } } else { if (S_ISDIR (st.st_mode)) flag = FTW_D; else if (S_ISLNK (st.st_mode)) flag = FTW_SL; else flag = FTW_F; } if (result == 0 && (flag == FTW_NS || !(data->flags & FTW_MOUNT) || st.st_dev == data->dev)) { if (flag == FTW_D) { if ((data->flags & FTW_PHYS) || (!find_object (data, &st) /* Remember the object. */ && (result = add_object (data, &st)) == 0)) result = ftw_dir (data, &st, dir); } else result = (*data->func) (data->dirbuf, &st, data->cvt_arr[flag], &data->ftw); } if ((data->flags & FTW_ACTIONRETVAL) && result == FTW_SKIP_SUBTREE) result = 0; return result; } static int __attribute ((noinline)) internal_function ftw_dir (struct ftw_data *data, struct STAT *st, struct dir_data *old_dir) { struct dir_data dir; struct dirent64 *d; int previous_base = data->ftw.base; int result; char *startp; /* Open the stream for this directory. This might require that another stream has to be closed. */ result = open_dir_stream (old_dir == NULL ? NULL : &old_dir->streamfd, data, &dir); if (result != 0) { if (errno == EACCES) /* We cannot read the directory. Signal this with a special flag. */ result = (*data->func) (data->dirbuf, st, FTW_DNR, &data->ftw); return result; } /* First, report the directory (if not depth-first). */ if (!(data->flags & FTW_DEPTH)) { result = (*data->func) (data->dirbuf, st, FTW_D, &data->ftw); if (result != 0) { int save_err; fail: save_err = errno; __closedir (dir.stream); dir.streamfd = -1; __set_errno (save_err); if (data->actdir-- == 0) data->actdir = data->maxdir - 1; data->dirstreams[data->actdir] = NULL; return result; } } /* If necessary, change to this directory. */ if (data->flags & FTW_CHDIR) { if (__fchdir (dirfd (dir.stream)) < 0) { result = -1; goto fail; } } /* Next, update the `struct FTW' information. */ ++data->ftw.level; startp = __rawmemchr (data->dirbuf, '\0'); /* There always must be a directory name. */ assert (startp != data->dirbuf); if (startp[-1] != '/') *startp++ = '/'; data->ftw.base = startp - data->dirbuf; while (dir.stream != NULL && (d = __readdir64 (dir.stream)) != NULL) { int d_type = DT_UNKNOWN; #ifdef _DIRENT_HAVE_D_TYPE d_type = d->d_type; #endif result = process_entry (data, &dir, d->d_name, NAMLEN (d), d_type); if (result != 0) break; } if (dir.stream != NULL) { /* The stream is still open. I.e., we did not need more descriptors. Simply close the stream now. */ int save_err = errno; assert (dir.content == NULL); __closedir (dir.stream); dir.streamfd = -1; __set_errno (save_err); if (data->actdir-- == 0) data->actdir = data->maxdir - 1; data->dirstreams[data->actdir] = NULL; } else { int save_err; char *runp = dir.content; while (result == 0 && *runp != '\0') { char *endp = strchr (runp, '\0'); // XXX Should store the d_type values as well?! result = process_entry (data, &dir, runp, endp - runp, DT_UNKNOWN); runp = endp + 1; } save_err = errno; free (dir.content); __set_errno (save_err); } if ((data->flags & FTW_ACTIONRETVAL) && result == FTW_SKIP_SIBLINGS) result = 0; /* Prepare the return, revert the `struct FTW' information. */ data->dirbuf[data->ftw.base - 1] = '\0'; --data->ftw.level; data->ftw.base = previous_base; /* Finally, if we process depth-first report the directory. */ if (result == 0 && (data->flags & FTW_DEPTH)) result = (*data->func) (data->dirbuf, st, FTW_DP, &data->ftw); if (old_dir && (data->flags & FTW_CHDIR) && (result == 0 || ((data->flags & FTW_ACTIONRETVAL) && (result != -1 && result != FTW_STOP)))) { /* Change back to the parent directory. */ int done = 0; if (old_dir->stream != NULL) if (__fchdir (dirfd (old_dir->stream)) == 0) done = 1; if (!done) { if (data->ftw.base == 1) { if (__chdir ("/") < 0) result = -1; } else if (__chdir ("..") < 0) result = -1; } } return result; } static int __attribute ((noinline)) internal_function ftw_startup (const char *dir, int is_nftw, void *func, int descriptors, int flags) { struct ftw_data data; struct STAT st; int result = 0; int save_err; int cwdfd = -1; char *cwd = NULL; char *cp; /* First make sure the parameters are reasonable. */ if (dir[0] == '\0') { __set_errno (ENOENT); return -1; } data.maxdir = descriptors < 1 ? 1 : descriptors; data.actdir = 0; data.dirstreams = (struct dir_data **) alloca (data.maxdir * sizeof (struct dir_data *)); memset (data.dirstreams, '\0', data.maxdir * sizeof (struct dir_data *)); /* PATH_MAX is always defined when we get here. */ data.dirbufsize = MAX (2 * strlen (dir), PATH_MAX); data.dirbuf = (char *) malloc (data.dirbufsize); if (data.dirbuf == NULL) return -1; cp = __stpcpy (data.dirbuf, dir); /* Strip trailing slashes. */ while (cp > data.dirbuf + 1 && cp[-1] == '/') --cp; *cp = '\0'; data.ftw.level = 0; /* Find basename. */ while (cp > data.dirbuf && cp[-1] != '/') --cp; data.ftw.base = cp - data.dirbuf; data.flags = flags; /* This assignment might seem to be strange but it is what we want. The trick is that the first three arguments to the `ftw' and `nftw' callback functions are equal. Therefore we can call in every case the callback using the format of the `nftw' version and get the correct result since the stack layout for a function call in C allows this. */ data.func = (NFTW_FUNC_T) func; /* Since we internally use the complete set of FTW_* values we need to reduce the value range before calling a `ftw' callback. */ data.cvt_arr = is_nftw ? nftw_arr : ftw_arr; /* No object known so far. */ data.known_objects = NULL; /* Now go to the directory containing the initial file/directory. */ if (flags & FTW_CHDIR) { /* We have to be able to go back to the current working directory. The best way to do this is to use a file descriptor. */ cwdfd = __open (".", O_RDONLY | O_DIRECTORY); if (cwdfd == -1) { /* Try getting the directory name. This can be needed if the current directory is executable but not readable. */ if (errno == EACCES) /* GNU extension ahead. */ cwd = __getcwd (NULL, 0); if (cwd == NULL) goto out_fail; } else if (data.maxdir > 1) /* Account for the file descriptor we use here. */ --data.maxdir; if (data.ftw.base > 0) { /* Change to the directory the file is in. In data.dirbuf we have a writable copy of the file name. Just NUL terminate it for now and change the directory. */ if (data.ftw.base == 1) /* I.e., the file is in the root directory. */ result = __chdir ("/"); else { char ch = data.dirbuf[data.ftw.base - 1]; data.dirbuf[data.ftw.base - 1] = '\0'; result = __chdir (data.dirbuf); data.dirbuf[data.ftw.base - 1] = ch; } } } /* Get stat info for start directory. */ if (result == 0) { const char *name; if (data.flags & FTW_CHDIR) { name = data.dirbuf + data.ftw.base; if (name[0] == '\0') name = "."; } else name = data.dirbuf; if (((flags & FTW_PHYS) ? LXSTAT (_STAT_VER, name, &st) : XSTAT (_STAT_VER, name, &st)) < 0) { if (!(flags & FTW_PHYS) && errno == ENOENT && LXSTAT (_STAT_VER, name, &st) == 0 && S_ISLNK (st.st_mode)) result = (*data.func) (data.dirbuf, &st, data.cvt_arr[FTW_SLN], &data.ftw); else /* No need to call the callback since we cannot say anything about the object. */ result = -1; } else { if (S_ISDIR (st.st_mode)) { /* Remember the device of the initial directory in case FTW_MOUNT is given. */ data.dev = st.st_dev; /* We know this directory now. */ if (!(flags & FTW_PHYS)) result = add_object (&data, &st); if (result == 0) result = ftw_dir (&data, &st, NULL); } else { int flag = S_ISLNK (st.st_mode) ? FTW_SL : FTW_F; result = (*data.func) (data.dirbuf, &st, data.cvt_arr[flag], &data.ftw); } } if ((flags & FTW_ACTIONRETVAL) && (result == FTW_SKIP_SUBTREE || result == FTW_SKIP_SIBLINGS)) result = 0; } /* Return to the start directory (if necessary). */ if (cwdfd != -1) { int save_err = errno; __fchdir (cwdfd); close_not_cancel_no_status (cwdfd); __set_errno (save_err); } else if (cwd != NULL) { int save_err = errno; __chdir (cwd); free (cwd); __set_errno (save_err); } /* Free all memory. */ out_fail: save_err = errno; __tdestroy (data.known_objects, free); free (data.dirbuf); __set_errno (save_err); return result; } /* Entry points. */ int FTW_NAME (const char *path, FTW_FUNC_T func, int descriptors) { return ftw_startup (path, 0, func, descriptors, 0); } #ifndef _LIBC int NFTW_NAME (const char *path, NFTW_FUNC_T func, int descriptors, int flags) { return ftw_startup (path, 1, func, descriptors, flags); } #else # include int NFTW_NEW_NAME (const char *, NFTW_FUNC_T, int, int); int NFTW_NEW_NAME (const char *path, NFTW_FUNC_T func, int descriptors, int flags) { if (flags & ~(FTW_PHYS | FTW_MOUNT | FTW_CHDIR | FTW_DEPTH | FTW_ACTIONRETVAL)) { __set_errno (EINVAL); return -1; } return ftw_startup (path, 1, func, descriptors, flags); } versioned_symbol (libc, NFTW_NEW_NAME, NFTW_NAME, GLIBC_2_3_3); # if SHLIB_COMPAT(libc, GLIBC_2_1, GLIBC_2_3_3) /* Older nftw* version just ignored all unknown flags. */ int NFTW_OLD_NAME (const char *, NFTW_FUNC_T, int, int); int attribute_compat_text_section NFTW_OLD_NAME (const char *path, NFTW_FUNC_T func, int descriptors, int flags) { flags &= (FTW_PHYS | FTW_MOUNT | FTW_CHDIR | FTW_DEPTH); return ftw_startup (path, 1, func, descriptors, flags); } compat_symbol (libc, NFTW_OLD_NAME, NFTW_NAME, GLIBC_2_1); # endif #endif