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Diffstat (limited to 'newlib/libc/sys/linux/ftw.c')
| -rw-r--r-- | newlib/libc/sys/linux/ftw.c | 640 |
1 files changed, 640 insertions, 0 deletions
diff --git a/newlib/libc/sys/linux/ftw.c b/newlib/libc/sys/linux/ftw.c new file mode 100644 index 000000000..a7f7259bc --- /dev/null +++ b/newlib/libc/sys/linux/ftw.c @@ -0,0 +1,640 @@ +/* File tree walker functions. + Copyright (C) 1996,1997,1998,1999,2000,2001 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +/* Modified for newlib by Jeff Johnston, July 26, 2002 */ + +#define _GNU_SOURCE 1 + +#include <dirent.h> +#include <errno.h> +#include <ftw.h> +#include <search.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <sys/param.h> +#include <sys/stat.h> + +extern struct dirent64 *__readdir64 (DIR *); + +/* #define NDEBUG 1 */ +#include <assert.h> + +/* 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 LXSTAT lstat +# define XSTAT stat +# define FTW_FUNC_T __ftw_func_t +# define NFTW_FUNC_T __nftw_func_t +#endif + +#define dirfd(x) ((x)->dd_fd) + +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'. */ + 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 the + process called `ftw' we must reduce the flag to the known flags + for `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); + + +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 dirent64 *d; + size_t actsize = 0; + + while ((d = __readdir64 (st)) != NULL) + { + size_t this_len = strlen (d->d_name); + 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 = 0; + + 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 (data->dirbuf, &st) + : XSTAT (data->dirbuf, &st)) < 0) + { + if (errno != EACCES && errno != ENOENT) + result = -1; + else if (!(data->flags & FTW_PHYS) + && LXSTAT (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 (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); + + 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 +ftw_dir (struct ftw_data *data, struct STAT *st) +{ + 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 (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'); + /* 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) + { + result = process_entry (data, &dir, d->d_name, strlen (d->d_name)); + 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; + + while (result == 0 && *runp != '\0') + { + char *endp = strchr (runp, '\0'); + + result = process_entry (data, &dir, runp, endp - runp); + + 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 +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 len; + char *cwd = NULL; + char *cp; + + /* First make sure the parameters are reasonable. */ + if (dir[0] == '\0') + { + __set_errno (ENOENT); + return -1; + } + + if (access (dir, R_OK) != 0) + 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; + len = strlen (dir); + cp = mempcpy (data.dirbuf, dir, len); + /* 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 (data.dirbuf, &st) + : XSTAT (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 (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); +} |