Add support for ftw and nftw

2 files changed, 660 insertions, 0 deletions

diff --git a/libc/misc/ftw/Makefile b/libc/misc/ftw/Makefile
new file mode 100644
index 000000000..7af2caca2
--- /dev/null
+++ b/libc/misc/ftw/Makefile
@@ -0,0 +1,39 @@
+# Makefile for uClibc
+#
+# Copyright (C) 2000-2003 Erik Andersen <andersen@uclibc.org>
+#
+# This program 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.
+#
+# This program 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 this program; if not, write to the Free Software Foundation, Inc.,
+# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+TOPDIR=../../../
+include $(TOPDIR)Rules.mak
+
+CSRC=ftw.c
+COBJS=$(patsubst %.c,%.o, $(CSRC))
+OBJS=$(COBJS)
+
+all: $(OBJS) $(LIBC)
+
+$(LIBC): ar-target
+
+ar-target: $(OBJS)
+	$(AR) $(ARFLAGS) $(LIBC) $(OBJS)
+
+$(COBJS): %.o : %.c
+	$(CC) $(CFLAGS) -c $< -o $@
+	$(STRIPTOOL) -x -R .note -R .comment $*.o
+
+clean:
+	rm -f *.[oa] *~ core
+
diff --git a/libc/misc/ftw/ftw.c b/libc/misc/ftw/ftw.c
new file mode 100644
index 000000000..e756c41ab
--- /dev/null
+++ b/libc/misc/ftw/ftw.c
@@ -0,0 +1,621 @@
+/* File tree walker functions.
+   Copyright (C) 1996-2001, 2002, 2003 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.  */
+
+#define _GNU_SOURCE
+#include <features.h>
+
+/* If Large file support is enabled, transparently remap
+ * things to use the 64-bit interfaces */
+#ifdef __UCLIBC_HAS_LFS__
+#if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS != 64 
+#undef _FILE_OFFSET_BITS
+#define	_FILE_OFFSET_BITS   64
+#endif
+#ifndef __USE_LARGEFILE64
+# define __USE_LARGEFILE64  1
+#endif
+#ifndef __USE_FILE_OFFSET64
+# define __USE_FILE_OFFSET64  1
+#endif
+#endif
+
+#include <alloca.h>
+#include <errno.h>
+#include <ftw.h>
+#include <limits.h>
+#include <search.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <assert.h>
+#include <dirent.h>
+
+/* 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;
+    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) 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 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;
+    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 (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 = (char *) 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)
+    {
+	const char *name = ((data->flags & FTW_CHDIR)
+		? data->dirbuf + data->ftw.base: data->dirbuf);
+	assert (data->dirstreams[data->actdir] == NULL);
+
+	dirp->stream = opendir (name);
+	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 int
+internal_function
+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;
+    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';
+
+    if ((data->flags & FTW_CHDIR) == 0)
+	name = data->dirbuf;
+
+    if (((data->flags & FTW_PHYS)
+		? lstat (name, &st)
+		: stat (name, &st)) < 0)
+    {
+	if (errno != EACCES && errno != ENOENT)
+	    result = -1;
+	else if (!(data->flags & FTW_PHYS)
+		&& lstat (name, &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 the parent 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
+			    if (chdir ("..") < 0)
+				result = -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)
+	{
+	    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 -1;
+	}
+    }
+
+    /* 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 = 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;
+
+	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
+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 (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)
+    {
+	/* GNU extension ahead.  */
+	cwd =  getcwd (NULL, 0);
+	if (cwd == NULL)
+	    result = -1;
+	else 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 = ((data.flags & FTW_CHDIR)
+		? data.dirbuf + data.ftw.base
+		: data.dirbuf);
+
+	if (((flags & FTW_PHYS)
+		    ? lstat (name, &st)
+		    : stat (name, &st)) < 0)
+	{
+	    if (!(flags & FTW_PHYS)
+		    && errno == ENOENT
+		    && lstat (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);
+	    }
+	    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 (const char *path, __ftw_func_t func, int descriptors)
+{
+    return ftw_startup (path, 0, func, descriptors, 0);
+}
+
+int nftw (const char *path, __nftw_func_t func, int descriptors, int flags)
+{
+    return ftw_startup (path, 1, func, descriptors, flags);
+}