/* File tree walker functions. Copyright (C) 1996, 1997 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 Library General Public License as published by the Free Software Foundation; either version 2 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 Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include #include #include #include #include #include #include #include #include /* #define NDEBUG 1 */ #include /* Support for the LFS API version. */ #ifndef FTW_NAME # define FTW_NAME ftw # define NFTW_NAME nftw # define INO_T ino_t # define STAT stat # define DIRENT dirent # define READDIR readdir # define LXSTAT __lxstat # define XSTAT __xstat # define FTW_FUNC_T __ftw_func_t # define NFTW_FUNC_T __nftw_func_t #endif struct dir_data { DIR *stream; 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 know by `ftw'. */ 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 the process called `ftw' we must reduce the flag to the known flags for `ftw'. */ static int nftw_arr[] = { FTW_F, FTW_D, FTW_DNR, FTW_NS, FTW_SL, FTW_DP, FTW_SLN }; static 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) 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->dev > kp2->dev) - (kp1->dev < kp2->dev); if (cmp1 != 0) return cmp1; return (kp1->ino > kp2->ino) - (kp1->ino < kp2->ino); } static inline 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 = { dev: st->st_dev, ino: st->st_ino }; return __tfind (&obj, &data->known_objects, object_compare) != NULL; } static inline int open_dir_stream (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 DIRENT *d; size_t actsize = 0; while ((d = READDIR (st)) != NULL) { size_t this_len = _D_EXACT_NAMLEN (d); if (actsize + this_len + 2 >= bufsize) { char *newp; bufsize += MAX (1024, 2 * this_len); newp = realloc (buf, bufsize); if (newp == NULL) { /* No more memory. */ int save_err = errno; free (buf); __set_errno (save_err); result = -1; break; } 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] = NULL; } } } /* Open the new stream. */ if (result == 0) { assert (data->dirstreams[data->actdir] == NULL); dirp->stream = opendir (data->dirbuf); if (dirp->stream == NULL) result = -1; else { dirp->content = NULL; data->dirstreams[data->actdir] = dirp; if (++data->actdir == data->maxdir) data->actdir = 0; } } return result; } static inline int process_entry (struct ftw_data *data, struct dir_data *dir, const char *name, size_t namlen) { struct STAT st; int result = 0; int flag; if (name[0] == '.' && (name[1] == '\0' || (name[1] == '.' && name[2] == '\0'))) /* Don't process the "." and ".." entries. */ return 0; if (data->dirbufsize < data->ftw.base + namlen + 2) { /* Enlarge the buffer. */ char *newp; data->dirbufsize *= 2; newp = realloc (data->dirbuf, data->dirbufsize); if (newp == NULL) return -1; data->dirbuf = newp; } *((char *) __mempcpy (data->dirbuf + data->ftw.base, name, namlen)) = '\0'; if (((data->flags & FTW_PHYS) ? LXSTAT (_STAT_VER, data->dirbuf, &st) : XSTAT (_STAT_VER, data->dirbuf, &st)) < 0) { if (errno != EACCES && errno != ENOENT) result = -1; else if (!(data->flags & FTW_PHYS) && LXSTAT (_STAT_VER, data->dirbuf, &st) == 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 ((data->flags & FTW_PHYS) || flag == FTW_NS || (!find_object (data, &st) /* Remember the object. */ && (result = add_object (data, &st)) == 0)) { if (flag == FTW_D) { result = ftw_dir (data, &st); if (result == 0 && (data->flags & FTW_CHDIR)) { /* Change back to current directory. */ int done = 0; if (dir->stream != NULL) if (__fchdir (dirfd (dir->stream)) == 0) done = 1; if (!done) { if (data->ftw.base == 1) { if (chdir ("/") < 0) result = -1; } else { /* Please note that we overwrite a slash. */ data->dirbuf[data->ftw.base - 1] = '\0'; if (chdir (data->dirbuf) < 0) result = -1; data->dirbuf[data->ftw.base - 1] = '/'; } } } } else result = (*data->func) (data->dirbuf, &st, data->cvt_arr[flag], &data->ftw); } } return result; } static int internal_function ftw_dir (struct ftw_data *data, struct STAT *st) { struct dir_data dir; struct DIRENT *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 (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) return result; } /* If necessary, change to this directory. */ if (data->flags & FTW_CHDIR) { if (__fchdir (dirfd (dir.stream)) < 0) { if (errno == ENOSYS) { if (chdir (data->dirbuf) < 0) result = -1; } else result = -1; } if (result != 0) { int save_err = errno; closedir (dir.stream); __set_errno (save_err); if (data->actdir-- == 0) data->actdir = data->maxdir - 1; data->dirstreams[data->actdir] = NULL; return result; } } /* Next, update the `struct FTW' information. */ ++data->ftw.level; startp = strchr (data->dirbuf, '\0'); *startp++ = '/'; data->ftw.base = startp - data->dirbuf; while (dir.stream != NULL && (d = READDIR (dir.stream)) != NULL) { result = process_entry (data, &dir, d->d_name, _D_EXACT_NAMLEN (d)); 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); __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; assert (result == 0); while (*runp != '\0') { char *endp = strchr (runp, '\0'); result = process_entry (data, &dir, runp, endp - runp); if (result != 0) break; runp = endp + 1; } save_err = errno; free (dir.content); __set_errno (save_err); } /* 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); return result; } static int 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; char *cwd = NULL; char *cp; /* First make sure the parameters are reasonable. */ if (dir[0] == '\0') { __set_errno (ENOTDIR); 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 *)); #ifdef PATH_MAX data.dirbufsize = MAX (2 * strlen (dir), PATH_MAX); #else data.dirbufsize = 2 * strlen (dir); #endif 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) && data.ftw.base > 0) { /* GNU extension ahead. */ cwd = getcwd (NULL, 0); if (cwd == NULL) result = -1; else { /* 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) if (((flags & FTW_PHYS) ? LXSTAT (_STAT_VER, data.dirbuf, &st) : XSTAT (_STAT_VER, data.dirbuf, &st)) < 0) { if (errno == EACCES) result = (*data.func) (data.dirbuf, &st, FTW_NS, &data.ftw); else if (!(flags & FTW_PHYS) && errno == ENOENT && LXSTAT (_STAT_VER, dir, &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); } else { int flag = S_ISLNK (st.st_mode) ? FTW_SL : FTW_F; result = (*data.func) (data.dirbuf, &st, data.cvt_arr[flag], &data.ftw); } } /* Return to the start directory (if necessary). */ if (cwd != NULL) { int save_err = errno; chdir (cwd); free (cwd); __set_errno (save_err); } /* Free all memory. */ save_err = errno; __tdestroy (data.known_objects, free); free (data.dirbuf); __set_errno (save_err); return result; } /* Entry points. */ int FTW_NAME (path, func, descriptors) const char *path; FTW_FUNC_T func; int descriptors; { return ftw_startup (path, 0, func, descriptors, 0); } int NFTW_NAME (path, func, descriptors, flags) const char *path; NFTW_FUNC_T func; int descriptors; int flags; { return ftw_startup (path, 1, func, descriptors, flags); }