Attachment #8496 for bug #43679

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 Open a directory.
********************************************************************/

static struct smb_Dir *OpenDir_internal(TALLOC_CTX *mem_ctx,
			connection_struct *conn,
			const char *name,
			const char *mask,
			uint32_t attr)

	return NULL;
}

struct smb_Dir *OpenDir(TALLOC_CTX *mem_ctx, connection_struct *conn,
			const char *name,
			const char *mask,
			uint32_t attr)
{
	return OpenDir_internal(mem_ctx,
				conn,
				name,
				mask,
				attr);
}

/*******************************************************************
 Open a directory from an fsp.
********************************************************************/
- 
SMB_VFS_OPENDIR failed.
--
source3/smbd/dir.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)




		return NULL;
	}

	dirp->conn = conn;
	dirp->name_cache_size = lp_directory_name_cache_size(SNUM(conn));

	dirp->dir_path = talloc_strdup(dirp, name);
	if (!dirp->dir_path) {
		errno = ENOMEM;
		goto fail;
	}

	if (sconn && !sconn->using_smb2) {
		sconn->searches.dirhandles_open++;
	}
	talloc_set_destructor(dirp, smb_Dir_destructor);

	dirp->dir = SMB_VFS_OPENDIR(conn, dirp->dir_path, mask, attr);
	if (!dirp->dir) {
		DEBUG(5,("OpenDir: Can't open %s. %s\n", dirp->dir_path,

		goto fail;
	}

	dirp->conn = conn;
	dirp->name_cache_size = lp_directory_name_cache_size(SNUM(conn));

	if (sconn && !sconn->using_smb2) {
		sconn->searches.dirhandles_open++;
	}
	talloc_set_destructor(dirp, smb_Dir_destructor);

	return dirp;

  fail:
- 
OpenDir().
--
source3/smbd/dir.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 61 insertions(+), 9 deletions(-)




		return NULL;
	}

	dirp->dir = SMB_VFS_OPENDIR(conn, name, mask, attr);
	if (!dirp->dir_path) {
		errno = ENOMEM;
		goto fail;
	}

	dirp->dir = SMB_VFS_OPENDIR(conn, dirp->dir_path, mask, attr);
	if (!dirp->dir) {
		DEBUG(5,("OpenDir: Can't open %s. %s\n", name,
			 strerror(errno) ));
		goto fail;
	}

	return NULL;
}

/****************************************************************************
 Open a directory handle by pathname, ensuring it's under the share path.
****************************************************************************/

static struct smb_Dir *open_dir_safely(TALLOC_CTX *ctx,
					connection_struct *conn,
					const char *name,
					const char *wcard,
					uint32_t attr)
{
	struct smb_Dir *dir_hnd = NULL;
	char *saved_dir = vfs_GetWd(ctx, conn);
	NTSTATUS status;

	if (saved_dir == NULL) {
		return NULL;
	}

	if (vfs_ChDir(conn, name) == -1) {
		goto out;
	}

	/*
	 * Now the directory is pinned, use
	 * REALPATH to ensure we can access it.
	 */
	status = check_name(conn, ".");
	if (!NT_STATUS_IS_OK(status)) {
		goto out;
	}

	dir_hnd = OpenDir_internal(ctx,
				conn,
				".",
				wcard,
				attr);

	if (dir_hnd == NULL) {
		goto out;
	}

	/*
	 * OpenDir_internal only gets "." as the dir name.
	 * Store the real dir name here.
	 */

	dir_hnd->dir_path = talloc_strdup(dir_hnd, name);
	if (!dir_hnd->dir_path) {
		errno = ENOMEM;
	}

  out:

	vfs_ChDir(conn, saved_dir);
	TALLOC_FREE(saved_dir);
	return dir_hnd;
}

struct smb_Dir *OpenDir(TALLOC_CTX *mem_ctx, connection_struct *conn,
			const char *name,
			const char *mask,
			uint32_t attr)
{
	return open_dir_safely(mem_ctx,
				conn,
				name,
				mask,
- 
--
source3/smbd/dir.c | 34 +++++++++++++++++++++-------------
1 file changed, 21 insertions(+), 13 deletions(-)




	struct smbd_server_connection *sconn = conn->sconn;

	if (!dirp) {
		goto fail;
	}

	if (!fsp->is_directory) {
		errno = EBADF;
		goto fail;
	}

	if (fsp->fh->fd == -1) {
		errno = EBADF;
		goto fail;
	}

	dirp->conn = conn;

	}
	talloc_set_destructor(dirp, smb_Dir_destructor);

	dirp->dir = SMB_VFS_FDOPENDIR(fsp, mask, attr);
	if (dirp->dir != NULL) {
		dirp->fsp = fsp;
	} else {
		DEBUG(10,("OpenDir_fsp: SMB_VFS_FDOPENDIR on %s returned "
			"NULL (%s)\n",
			dirp->dir_path,
			strerror(errno)));
		if (errno != ENOSYS) {
			return NULL;
				return NULL;
			}
		}
	}

- 
--
source3/smbd/dir.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)




			dirp->dir_path,
			strerror(errno)));
		if (errno != ENOSYS) {
			goto fail;
		}
	}

- 
setup to just before retuning success.
--
source3/smbd/dir.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)




		goto fail;
	}

	if (sconn && !sconn->using_smb2) {
		sconn->searches.dirhandles_open++;
	}
	talloc_set_destructor(dirp, smb_Dir_destructor);

	dirp->dir = SMB_VFS_FDOPENDIR(fsp, mask, attr);
	if (dirp->dir != NULL) {
		dirp->fsp = fsp;

		goto fail;
	}

	if (sconn && !sconn->using_smb2) {
		sconn->searches.dirhandles_open++;
	}
	talloc_set_destructor(dirp, smb_Dir_destructor);

	return dirp;

  fail:
- 
FDOPENDIR not supported on system.
--
source3/smbd/dir.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)




	}

	if (dirp->dir == NULL) {
		/* FDOPENDIR is not supported. Use OPENDIR instead. */
		TALLOC_FREE(dirp);
		return open_dir_safely(mem_ctx,
					conn,
					fsp->fsp_name->base_name,
					mask,
					attr);
		goto fail;
	}

	if (sconn && !sconn->using_smb2) {
- 
O_NOFOLLOW existing.
--
source3/smbd/open.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)




	struct smb_filename *smb_fname = fsp->fsp_name;
	NTSTATUS status = NT_STATUS_OK;

	/*
	/* 
	 * Never follow symlinks on a POSIX client. The
	 * client should be doing this.
	 */

	if ((fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) || !lp_follow_symlinks(SNUM(conn))) {
		flags |= O_NOFOLLOW;
	}
#endif

	fsp->fh->fd = SMB_VFS_OPEN(conn, smb_fname, fsp, flags, mode);
	if (fsp->fh->fd == -1) {
		int posix_errno = errno;
#ifdef O_NOFOLLOW
#if defined(ENOTSUP) && defined(OSF1)
		/* handle special Tru64 errno */
		if (errno == ENOTSUP) {

		if (errno == EMLINK) {
			posix_errno = ELOOP;
		}
#endif /* O_NOFOLLOW */
		status = map_nt_error_from_unix(posix_errno);
		if (errno == EMFILE) {
			static time_t last_warned = 0L;
- 
a utility function.
--
source3/smbd/open.c | 43 ++++++++++++++++++++++++++-----------------
1 file changed, 26 insertions(+), 17 deletions(-)




}

/****************************************************************************
 Handle differing symlink errno's
****************************************************************************/

static int link_errno_convert(int err)
{
#if defined(ENOTSUP) && defined(OSF1)
	/* handle special Tru64 errno */
	if (err == ENOTSUP) {
		err = ELOOP;
	}
#endif /* ENOTSUP */
#ifdef EFTYPE
	/* fix broken NetBSD errno */
	if (err == EFTYPE) {
		err = ELOOP;
	}
#endif /* EFTYPE */
	/* fix broken FreeBSD errno */
	if (err == EMLINK) {
		err = ELOOP;
	}
	return err;
}

/****************************************************************************
 fd support routines - attempt to do a dos_open.
****************************************************************************/



	fsp->fh->fd = SMB_VFS_OPEN(conn, smb_fname, fsp, flags, mode);
	if (fsp->fh->fd == -1) {
		int posix_errno = link_errno_convert(errno);
#if defined(ENOTSUP) && defined(OSF1)
		/* handle special Tru64 errno */
		if (errno == ENOTSUP) {
			posix_errno = ELOOP;
		}
#endif /* ENOTSUP */
#ifdef EFTYPE
		/* fix broken NetBSD errno */
		if (errno == EFTYPE) {
			posix_errno = ELOOP;
		}
#endif /* EFTYPE */
		/* fix broken FreeBSD errno */
		if (errno == EMLINK) {
			posix_errno = ELOOP;
		}
		status = map_nt_error_from_unix(posix_errno);
		if (errno == EMFILE) {
			static time_t last_warned = 0L;
- 
open races.
--
source3/smbd/open.c | 237 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 237 insertions(+)




	return err;
}

static int non_widelink_open(struct connection_struct *conn,
			const char *conn_rootdir,
			files_struct *fsp,
			struct smb_filename *smb_fname,
			int flags,
			mode_t mode,
			unsigned int link_depth);

/****************************************************************************
 Follow a symlink in userspace.
****************************************************************************/

static int process_symlink_open(struct connection_struct *conn,
			const char *conn_rootdir,
			files_struct *fsp,
			struct smb_filename *smb_fname,
			int flags,
			mode_t mode,
			unsigned int link_depth)
{
	int fd = -1;
	char *link_target = NULL;
	int link_len = -1;
	char *oldwd = NULL;
	size_t rootdir_len = 0;
	char *resolved_name = NULL;
	bool matched = false;
	int saved_errno = 0;

	/*
	 * Ensure we don't get stuck in a symlink loop.
	 */
	link_depth++;
	if (link_depth >= 20) {
		errno = ELOOP;
		goto out;
	}

	/* Allocate space for the link target. */
	link_target = talloc_array(talloc_tos(), char, PATH_MAX);
	if (link_target == NULL) {
		errno = ENOMEM;
		goto out;
	}

	/* Read the link target. */
	link_len = SMB_VFS_READLINK(conn,
				smb_fname->base_name,
				link_target,
				PATH_MAX - 1);
	if (link_len == -1) {
		goto out;
	}

	/* Ensure it's at least null terminated. */
	link_target[link_len] = '\0';

	/* Convert to an absolute path. */
	resolved_name = SMB_VFS_REALPATH(conn, link_target);
	if (resolved_name == NULL) {
		goto out;
	}

	/*
	 * We know conn_rootdir starts with '/' and
	 * does not end in '/'. FIXME ! Should we
	 * smb_assert this ?
	 */
	rootdir_len = strlen(conn_rootdir);

	matched = (strncmp(conn_rootdir, resolved_name, rootdir_len) == 0);
	if (!matched) {
		errno = EACCES;
		goto out;
	}

	/*
	 * Turn into a path relative to the share root.
	 */
	if (resolved_name[rootdir_len] == '\0') {
		/* Link to the root of the share. */
		smb_fname->base_name = talloc_strdup(talloc_tos(), ".");
		if (smb_fname->base_name == NULL) {
			errno = ENOMEM;
			goto out;
		}
	} else if (resolved_name[rootdir_len] == '/') {
		smb_fname->base_name = &resolved_name[rootdir_len+1];
	} else {
		errno = EACCES;
		goto out;
	}

	oldwd = vfs_GetWd(talloc_tos(), conn);
	if (oldwd == NULL) {
		goto out;
	}

	/* Ensure we operate from the root of the share. */
	if (vfs_ChDir(conn, conn_rootdir) == -1) {
		goto out;
	}

	/* And do it all again.. */
	fd = non_widelink_open(conn,
				conn_rootdir,
				fsp,
				smb_fname,
				flags,
				mode,
				link_depth);
	if (fd == -1) {
		saved_errno = errno;
	}

  out:

	SAFE_FREE(resolved_name);
	TALLOC_FREE(link_target);
	if (oldwd != NULL) {
		int ret = vfs_ChDir(conn, oldwd);
		if (ret == -1) {
			smb_panic("unable to get back to old directory\n");
		}
		TALLOC_FREE(oldwd);
	}
	if (saved_errno != 0) {
		errno = saved_errno;
	}
	return fd;
}

/****************************************************************************
 Non-widelink open.
****************************************************************************/

static int non_widelink_open(struct connection_struct *conn,
			const char *conn_rootdir,
			files_struct *fsp,
			struct smb_filename *smb_fname,
			int flags,
			mode_t mode,
			unsigned int link_depth)
{
	NTSTATUS status;
	int fd = -1;
	struct smb_filename *smb_fname_rel = NULL;
	int saved_errno = 0;
	char *oldwd = NULL;
	char *parent_dir = NULL;
	const char *final_component = NULL;

	if (!parent_dirname(talloc_tos(),
			smb_fname->base_name,
			&parent_dir,
			&final_component)) {
		goto out;
	}

	oldwd = vfs_GetWd(talloc_tos(), conn);
	if (oldwd == NULL) {
		goto out;
	}

	/* Pin parent directory in place. */
	if (vfs_ChDir(conn, parent_dir) == -1) {
		goto out;
	}

	/* Ensure the relative path is below the share. */
	status = check_reduced_name(conn, final_component);
	if (!NT_STATUS_IS_OK(status)) {
		saved_errno = map_errno_from_nt_status(status);
		goto out;
	}

	smb_fname_rel = synthetic_smb_fname(talloc_tos(),
				final_component,
				smb_fname->stream_name,
				&smb_fname->st);

	flags |= O_NOFOLLOW;

	{
		struct smb_filename *tmp_name = fsp->fsp_name;
		fsp->fsp_name = smb_fname_rel;
		fd = SMB_VFS_OPEN(conn, smb_fname_rel, fsp, flags, mode);
		fsp->fsp_name = tmp_name;
	}

	if (fd == -1) {
		saved_errno = link_errno_convert(errno);
		if (saved_errno == ELOOP) {
			if (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) {
				/* Never follow symlinks on posix open. */
				goto out;
			}
			if (!lp_follow_symlinks(SNUM(conn))) {
				/* Explicitly no symlinks. */
				goto out;
			}
			/*
			 * We have a symlink. Follow in userspace
			 * to ensure it's under the share definition.
			 */
			fd = process_symlink_open(conn,
					conn_rootdir,
					fsp,
					smb_fname_rel,
					flags,
					mode,
					link_depth);
			if (fd == -1) {
				saved_errno =
					link_errno_convert(errno);
			}
		}
	}

  out:

	TALLOC_FREE(parent_dir);
	TALLOC_FREE(smb_fname_rel);

	if (oldwd != NULL) {
		int ret = vfs_ChDir(conn, oldwd);
		if (ret == -1) {
			smb_panic("unable to get back to old directory\n");
		}
		TALLOC_FREE(oldwd);
	}
	if (saved_errno != 0) {
		errno = saved_errno;
	}
	return fd;
}

/****************************************************************************
 fd support routines - attempt to do a dos_open.
****************************************************************************/
- 
--
source3/smbd/open.c | 23 ++++++++++++++++++++++-
1 file changed, 22 insertions(+), 1 deletion(-)




		flags |= O_NOFOLLOW;
	}

	/* Ensure path is below share definition. */
	if (!lp_widelinks(SNUM(conn))) {
		const char *conn_rootdir = SMB_VFS_CONNECTPATH(conn,
						smb_fname->base_name);
		if (conn_rootdir == NULL) {
			return NT_STATUS_NO_MEMORY;
		}
		/*
		 * Only follow symlinks within a share
		 * definition.
		 */
		fsp->fh->fd = non_widelink_open(conn,
					conn_rootdir,
					fsp,
					smb_fname,
					flags,
					mode,
					0);
	} else {
		fsp->fh->fd = SMB_VFS_OPEN(conn, smb_fname, fsp, flags, mode);
	}

	if (fsp->fh->fd == -1) {
		int posix_errno = link_errno_convert(errno);
		status = map_nt_error_from_unix(posix_errno);
- 

Return to bug 43679