s3: Add the "scannedonly" vfs virus scanner interface module

1 files changed, 995 insertions, 0 deletions

diff --git a/source3/modules/vfs_scannedonly.c b/source3/modules/vfs_scannedonly.c
new file mode 100644
index 0000000000..8699bff162
--- /dev/null
+++ b/source3/modules/vfs_scannedonly.c
@@ -0,0 +1,995 @@
+/*
+ * scannedonly VFS module for Samba 3.5
+ *
+ * Copyright 2007,2008,2009 (C) Olivier Sessink
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * ABOUT SCANNEDONLY
+ *
+ * scannedonly implements a 'filter' like vfs module that talks over a
+ * unix domain socket or over UDP to a anti-virus engine.
+ *
+ * files that are clean have a corresponding .scanned:{filename} file
+ * in the same directory. So why the .scanned: files? They take up
+ * only an inode, because they are 0 bytes. To test if the file is
+ * scanned only a stat() call on the filesystem is needed which is
+ * very quick compared to a database lookup. All modern filesystems
+ * use database technology such as balanced trees for lookups anyway.
+ * The number of inodes in modern filesystems is also not limiting
+ * anymore. The .scanned: files are also easy scriptable. You can
+ * remove them with a simple find command or create them with a
+ * simple touch command. Extended filesystem attributes have similar
+ * properties, but are not supported on all filesystems, so that
+ * would limit the usage of the module (and attributes are not as
+ * easily scriptable)
+ *
+ * files that are not clean are sent to the AV-engine. Only the
+ * filename is sent over the socket. The protocol is very simple:
+ * a newline separated list of filenames inside each datagram.
+ *
+ * a file AV-scan may be requested multiple times, the AV-engine
+ * should also check if the file has been scanned already. Requests
+ * can also be dropped by the AV-engine (and we thus don't need the
+ * reliability of TCP).
+ *
+ */
+
+#include "includes.h"
+
+#include "config.h"
+
+#define SENDBUFFERSIZE 1450
+
+struct Tscannedonly {
+	int socket;
+	int domain_socket;
+	int portnum;
+	int scanning_message_len;
+	int recheck_time_open;
+	int recheck_tries_open;
+	int recheck_size_open;
+	int recheck_time_readdir;
+	int recheck_tries_readdir;
+	bool show_special_files;
+	bool rm_hidden_files_on_rmdir;
+	bool hide_nonscanned_files;
+	bool allow_nonscanned_files;
+	char *socketname;
+	char *scanhost;
+	char *scanning_message;
+	char *p_scanned; /* prefix for scanned files */
+	char *p_virus; /* prefix for virus containing files */
+	char *p_failed; /* prefix for failed to scan files */
+	char gsendbuffer[SENDBUFFERSIZE + 1];
+};
+
+#define STRUCTSCANO(var) ((struct Tscannedonly *)var)
+
+struct scannedonly_DIR {
+	char *base;
+	int notify_loop_done;
+	SMB_STRUCT_DIR *DIR;
+};
+#define SCANNEDONLY_DEBUG 9
+/*********************/
+/* utility functions */
+/*********************/
+
+static char *real_path_from_notify_path(TALLOC_CTX *ctx,
+					struct Tscannedonly *so,
+					const char *path)
+{
+	char *name;
+	int len, pathlen;
+
+	name = strrchr(path, '/');
+	if (!name) {
+		return NULL;
+	}
+	pathlen = name - path;
+	name++;
+	len = strlen(name);
+	if (len <= so->scanning_message_len) {
+		return NULL;
+	}
+
+	if (strcmp(name + (len - so->scanning_message_len),
+		   so->scanning_message) != 0) {
+		return NULL;
+	}
+
+	return talloc_strndup(ctx,path,
+			      pathlen + len - so->scanning_message_len);
+}
+
+static char *cachefile_name(TALLOC_CTX *ctx,
+			    const char *shortname,
+			    const char *base,
+			    const char *p_scanned)
+{
+	return talloc_asprintf(ctx, "%s%s%s", base, p_scanned, shortname);
+}
+
+static char *name_w_ending_slash(TALLOC_CTX *ctx, const char *name)
+{
+	int len = strlen(name);
+	if (name[len - 1] == '/') {
+		return talloc_strdup(ctx,name);
+	} else {
+		return talloc_asprintf(ctx, "%s/", name);
+	}
+}
+
+static char *cachefile_name_f_fullpath(TALLOC_CTX *ctx,
+				       const char *fullpath,
+				       const char *p_scanned)
+{
+	const char *base;
+	char *tmp, *cachefile, *shortname;
+	tmp = strrchr(fullpath, '/');
+	if (tmp) {
+		base = talloc_strndup(ctx, fullpath, (tmp - fullpath) + 1);
+		shortname = tmp + 1;
+	} else {
+		base = "";
+		shortname = (char *)fullpath;
+	}
+	cachefile = cachefile_name(ctx, shortname, base, p_scanned);
+	DEBUG(SCANNEDONLY_DEBUG,
+	      ("cachefile_name_f_fullpath cachefile=%s\n", cachefile));
+	return cachefile;
+}
+
+static char *path_plus_name(TALLOC_CTX *ctx, const char *base,
+			    const char *filename)
+{
+	return talloc_asprintf(ctx, "%s%s", base,filename);
+}
+
+static char *construct_full_path(TALLOC_CTX *ctx, vfs_handle_struct * handle,
+				 const char *somepath, bool ending_slash)
+{
+	char *tmp;
+
+	if (!somepath) {
+		return NULL;
+	}
+	if (somepath[0] == '/') {
+		if (ending_slash) {
+			return name_w_ending_slash(ctx,somepath);
+		}
+		return talloc_strdup(ctx,somepath);
+	}
+	tmp=(char *)somepath;
+	if (tmp[0]=='.'&&tmp[1]=='/') {
+		tmp+=2;
+	}
+	/* vfs_GetWd() seems to return a path with a slash */
+	if (ending_slash) {
+		return talloc_asprintf(ctx, "%s%s/",
+				       vfs_GetWd(ctx, handle->conn),tmp);
+	}
+	return talloc_asprintf(ctx, "%s%s",
+			       vfs_GetWd(ctx, handle->conn),tmp);
+}
+
+static int connect_to_scanner(vfs_handle_struct * handle)
+{
+	struct Tscannedonly *so = (struct Tscannedonly *)handle->data;
+
+	if (so->domain_socket) {
+		struct sockaddr_un saun;
+		DEBUG(SCANNEDONLY_DEBUG, ("socket=%s\n", so->socketname));
+		if ((so->socket = socket(AF_UNIX, SOCK_DGRAM, 0)) < 0) {
+			DEBUG(2, ("failed to create socket %s\n",
+				  so->socketname));
+			return -1;
+		}
+		saun.sun_family = AF_UNIX;
+		strncpy(saun.sun_path, so->socketname,
+			strlen(so->socketname) + 1);
+		if (connect(so->socket, (struct sockaddr *)(void *)&saun,
+			    SUN_LEN(&saun)) < 0) {
+			DEBUG(2, ("failed to connect to socket %s\n",
+				  so->socketname));
+			return -1;
+		}
+		DEBUG(SCANNEDONLY_DEBUG,("bound %s to socket %d\n",
+					 saun.sun_path, so->socket));
+
+	} else {
+		so->socket = open_udp_socket(so->scanhost, so->portnum);
+		if (so->socket < 0) {
+			DEBUG(2,("failed to open UDP socket to %s:%d\n",
+				 so->scanhost,so->portnum));
+			return -1;
+		}
+	}
+
+	{/* increasing the socket buffer is done because we have large bursts
+	    of UDP packets or DGRAM's on a domain socket whenever we hit a
+	    large directory with lots of unscanned files. */
+		int sndsize;
+		socklen_t size = sizeof(int);
+		getsockopt(so->socket, SOL_SOCKET, SO_RCVBUF,
+			   (char *)&sndsize, &size);
+		DEBUG(SCANNEDONLY_DEBUG, ("current socket buffer size=%d\n",
+					  sndsize));
+		sndsize = 262144;
+		if (setsockopt(so->socket, SOL_SOCKET, SO_RCVBUF,
+			       (char *)&sndsize,
+			       (int)sizeof(sndsize)) != 0) {
+			DEBUG(SCANNEDONLY_DEBUG,
+			      ("error setting socket buffer %s (%d)\n",
+			       strerror(errno), errno));
+		}
+	}
+	set_blocking(so->socket, false);
+	return 0;
+}
+
+static void flush_sendbuffer(vfs_handle_struct * handle)
+{
+	struct Tscannedonly *so = (struct Tscannedonly *)handle->data;
+	int ret, len, loop = 10;
+	if (so->gsendbuffer[0] == '\0') {
+		return;
+	}
+
+	do {
+		loop--;
+		len = strlen(so->gsendbuffer);
+		ret = send(so->socket, so->gsendbuffer, len, MSG_DONTWAIT);
+		if (ret == len) {
+			so->gsendbuffer[0] = '\0';
+			break;
+		}
+		if (ret == -1) {
+			DEBUG(3,("scannedonly flush_sendbuffer: "
+				 "error sending on socket %d to scanner:"
+				 " %s (%d)\n",
+				 so->socket, strerror(errno), errno));
+			if (errno == ECONNREFUSED || errno == ENOTCONN
+			    || errno == ECONNRESET) {
+				if (connect_to_scanner(handle) == -1)
+					break;	/* connecting fails, abort */
+				/* try again */
+			} else if (errno != EINTR) {
+				/* on EINTR we just try again, all remaining
+				   other errors we log the error
+				   and try again ONCE */
+				loop = 1;
+				DEBUG(3,("scannedonly flush_sendbuffer: "
+					 "error sending data to scanner: %s "
+					 "(%d)\n", strerror(errno), errno));
+			}
+		} else {
+			/* --> partial write: Resend all filenames that were
+			   not or not completely written. a partial filename
+			   written means the filename will not arrive correctly,
+			   so resend it completely */
+			int pos = 0;
+			while (pos < len) {
+				char *tmp = strchr(so->gsendbuffer+pos, '\n');
+				if (tmp && tmp - so->gsendbuffer < ret)
+					pos = tmp - so->gsendbuffer + 1;
+				else
+					break;
+			}
+			memmove(so->gsendbuffer, so->gsendbuffer + pos,
+				SENDBUFFERSIZE - ret);
+			/* now try again */
+		}
+	} while (loop > 0);
+
+	if (so->gsendbuffer[0] != '\0') {
+		DEBUG(2,
+		      ("scannedonly flush_sendbuffer: "
+		       "failed to send files to AV scanner, "
+		       "discarding files."));
+		so->gsendbuffer[0] = '\0';
+	}
+}
+
+static void notify_scanner(vfs_handle_struct * handle, const char *scanfile)
+{
+	char *tmp;
+	int tmplen, gsendlen;
+	struct Tscannedonly *so = (struct Tscannedonly *)handle->data;
+	TALLOC_CTX *ctx=talloc_tos();
+	if (scanfile[0] != '/') {
+		tmp = construct_full_path(ctx,handle, scanfile, false);
+	} else {
+		tmp = (char *)scanfile;
+	}
+	tmplen = strlen(tmp);
+	gsendlen = strlen(so->gsendbuffer);
+	DEBUG(SCANNEDONLY_DEBUG,
+	      ("scannedonly notify_scanner: tmp=%s, tmplen=%d, gsendlen=%d\n",
+	       tmp, tmplen, gsendlen));
+	if (gsendlen + tmplen >= SENDBUFFERSIZE) {
+		flush_sendbuffer(handle);
+	}
+	strncat(so->gsendbuffer, tmp, tmplen);
+	strncat(so->gsendbuffer, "\n", 1);
+}
+
+static bool is_scannedonly_file(struct Tscannedonly *so, const char *shortname)
+{
+	if (shortname[0]!='.') {
+		return false;
+	}
+	if (strncmp(shortname, so->p_scanned, strlen(so->p_scanned)) == 0) {
+		return true;
+	}
+	if (strncmp(shortname, so->p_virus, strlen(so->p_virus)) == 0) {
+		return true;
+	}
+	if (strncmp(shortname, so->p_failed, strlen(so->p_failed)) == 0) {
+		return true;
+	}
+	return false;
+}
+
+static bool timespec_is_newer(struct timespec *base, struct timespec *test)
+{
+	return timespec_compare(base,test) < 0;
+}
+
+/*
+vfs_handle_struct *handle the scannedonly handle
+scannedonly_DIR * sDIR the scannedonly struct if called from _readdir()
+or NULL
+fullpath is a full path starting from / or a relative path to the
+current working directory
+shortname is the filename without directory components
+basename, is the directory without file name component
+allow_nonexistant return TRUE if stat() on the requested file fails
+recheck_time, the time in milliseconds to wait for the daemon to
+create a .scanned file
+recheck_tries, the number of tries to wait
+recheck_size, size in Kb of files that should not be waited for
+loop : boolean if we should try to loop over all files in the directory
+and send a notify to the scanner for all files that need scanning
+*/
+static bool scannedonly_allow_access(vfs_handle_struct * handle,
+				     struct scannedonly_DIR *sDIR,
+				     struct smb_filename *smb_fname,
+				     const char *shortname,
+				     const char *base_name,
+				     int allow_nonexistant,
+				     int recheck_time, int recheck_tries,
+				     int recheck_size, int loop)
+{
+	struct smb_filename *cache_smb_fname;
+	TALLOC_CTX *ctx=talloc_tos();
+	char *cachefile;
+	int retval;
+	int didloop;
+	DEBUG(SCANNEDONLY_DEBUG,
+	      ("smb_fname->base_name=%s, shortname=%s, base_name=%s\n"
+	       ,smb_fname->base_name,shortname,base_name));
+
+	if (ISDOT(shortname) || ISDOTDOT(shortname)) {
+		return true;
+	}
+	if (is_scannedonly_file(STRUCTSCANO(handle->data), shortname)) {
+		DEBUG(SCANNEDONLY_DEBUG,
+		      ("scannedonly_allow_access, %s is a scannedonly file, "
+		       "return 0\n", shortname));
+		return false;
+	}
+
+	if (!VALID_STAT(smb_fname->st)) {
+		DEBUG(SCANNEDONLY_DEBUG,("stat %s\n",smb_fname->base_name));
+		retval = SMB_VFS_NEXT_STAT(handle, smb_fname);
+		if (retval != 0) {
+			/* failed to stat this file?!? --> hide it */
+			DEBUG(SCANNEDONLY_DEBUG,("no valid stat, return"
+						 " allow_nonexistant=%d\n",
+						 allow_nonexistant));
+			return allow_nonexistant;
+		}
+	}
+	if (!S_ISREG(smb_fname->st.st_ex_mode)) {
+		DEBUG(SCANNEDONLY_DEBUG,
+		      ("%s is not a regular file, ISDIR=%d\n",
+		       smb_fname->base_name,
+		       S_ISDIR(smb_fname->st.st_ex_mode)));
+		return (STRUCTSCANO(handle->data)->
+			show_special_files ||
+			S_ISDIR(smb_fname->st.st_ex_mode));
+	}
+	if (smb_fname->st.st_ex_size == 0) {
+		DEBUG(SCANNEDONLY_DEBUG,("empty file, return 1\n"));
+		return true;	/* empty files cannot contain viruses ! */
+	}
+	cachefile = cachefile_name(ctx,
+				   shortname,
+				   base_name,
+				   STRUCTSCANO(handle->data)->p_scanned);
+	create_synthetic_smb_fname(ctx, cachefile,NULL,NULL,&cache_smb_fname);
+	if (!VALID_STAT(cache_smb_fname->st)) {
+		retval = SMB_VFS_NEXT_STAT(handle, cache_smb_fname);
+	}
+	if (retval == 0 && VALID_STAT(cache_smb_fname->st)) {
+		if (timespec_is_newer(&smb_fname->st.st_ex_mtime,
+				      &cache_smb_fname->st.st_ex_mtime)) {
+			talloc_free(cache_smb_fname);
+			return true;
+		}
+		/* no cachefile or too old */
+		SMB_VFS_NEXT_UNLINK(handle, cache_smb_fname);
+		retval = -1;
+	}
+
+	notify_scanner(handle, smb_fname->base_name);
+
+	didloop = 0;
+	if (loop && sDIR && !sDIR->notify_loop_done) {
+		/* check the rest of the directory and notify the
+		   scanner if some file needs scanning */
+		long offset;
+		SMB_STRUCT_DIRENT *dire;
+
+		offset = SMB_VFS_NEXT_TELLDIR(handle, sDIR->DIR);
+		dire = SMB_VFS_NEXT_READDIR(handle, sDIR->DIR, NULL);
+		while (dire) {
+			char *fpath2;
+			struct smb_filename *smb_fname2;
+			fpath2 = path_plus_name(ctx,base_name, dire->d_name);
+			DEBUG(SCANNEDONLY_DEBUG,
+			      ("scannedonly_allow_access in loop, "
+			       "found %s\n", fpath2));
+			create_synthetic_smb_fname(ctx, fpath2,NULL,NULL,
+						   &smb_fname2);
+			scannedonly_allow_access(handle, NULL,
+						 smb_fname2,
+						 dire->d_name,
+						 base_name, 0, 0, 0, 0, 0);
+			talloc_free(fpath2);
+			talloc_free(smb_fname2);
+			dire = SMB_VFS_NEXT_READDIR(handle, sDIR->DIR,NULL);
+		}
+		sDIR->notify_loop_done = 1;
+		didloop = 1;
+		SMB_VFS_NEXT_SEEKDIR(handle, sDIR->DIR, offset);
+	}
+	if (recheck_time > 0
+	    && ((recheck_size > 0
+		 && smb_fname->st.st_ex_size < (1024 * recheck_size))
+		|| didloop)) {
+		int i = 0;
+		flush_sendbuffer(handle);
+		while (retval != 0	/*&& errno == ENOENT */
+		       && i < recheck_tries) {
+			struct timespec req = { 0, recheck_time * 10000 };
+			DEBUG(SCANNEDONLY_DEBUG,
+			      ("scannedonly_allow_access, wait (try=%d "
+			       "(max %d), %d ms) for %s\n",
+			       i, recheck_tries,
+			       recheck_time, cache_smb_fname->base_name));
+			nanosleep(&req, NULL);
+			retval = SMB_VFS_NEXT_STAT(handle, cache_smb_fname);
+			i++;
+		}
+	}
+	/* still no cachefile, or still too old, return 0 */
+	if (retval != 0
+	    || !timespec_is_newer(&smb_fname->st.st_ex_mtime,
+				  &cache_smb_fname->st.st_ex_mtime)) {
+		DEBUG(SCANNEDONLY_DEBUG,
+		      ("retval=%d, return 0\n",retval));
+		return false;
+	}
+	return true;
+}
+
+/*********************/
+/* VFS functions     */
+/*********************/
+
+static SMB_STRUCT_DIR *scannedonly_opendir(vfs_handle_struct * handle,
+					   const char *fname,
+					   const char *mask, uint32 attr)
+{
+	SMB_STRUCT_DIR *DIRp;
+	struct scannedonly_DIR *sDIR;
+
+	DIRp = SMB_VFS_NEXT_OPENDIR(handle, fname, mask, attr);
+	if (!DIRp) {
+		return NULL;
+	}
+
+	sDIR = TALLOC_P(NULL, struct scannedonly_DIR);
+	if (fname[0] != '/') {
+		sDIR->base = construct_full_path(sDIR,handle, fname, true);
+	} else {
+		sDIR->base = name_w_ending_slash(sDIR, fname);
+	}
+	sDIR->DIR = DIRp;
+	sDIR->notify_loop_done = 0;
+	return (SMB_STRUCT_DIR *) sDIR;
+}
+
+static SMB_STRUCT_DIRENT *scannedonly_readdir(vfs_handle_struct *handle,
+					      SMB_STRUCT_DIR * dirp,
+					      SMB_STRUCT_STAT *sbuf)
+{
+	SMB_STRUCT_DIRENT *result;
+	int allowed = 0;
+	char *tmp;
+	struct smb_filename *smb_fname;
+	char *notify_name;
+	int namelen;
+	SMB_STRUCT_DIRENT *newdirent;
+	TALLOC_CTX *ctx=talloc_tos();
+
+	struct scannedonly_DIR *sDIR = (struct scannedonly_DIR *)dirp;
+	if (!dirp) {
+		return NULL;
+	}
+
+	result = SMB_VFS_NEXT_READDIR(handle, sDIR->DIR, sbuf);
+
+	if (!result)
+		return NULL;
+
+	if (is_scannedonly_file(STRUCTSCANO(handle->data), result->d_name)) {
+		DEBUG(SCANNEDONLY_DEBUG,
+		      ("scannedonly_readdir, %s is a scannedonly file, "
+		       "skip to next entry\n", result->d_name));
+		return scannedonly_readdir(handle, dirp, NULL);
+	}
+
+	tmp = path_plus_name(ctx,sDIR->base, result->d_name);
+	DEBUG(SCANNEDONLY_DEBUG,
+	      ("scannedonly_readdir, check access to %s (sbuf=%p)\n",
+	       tmp,sbuf));
+
+	/* even if we don't hide nonscanned files or we allow non scanned
+	   files we call allow_access because it will notify the daemon to
+	   scan these files */
+	create_synthetic_smb_fname(ctx, tmp,NULL,
+				   sbuf?VALID_STAT(*sbuf)?sbuf:NULL:NULL,
+				   &smb_fname);
+	allowed = scannedonly_allow_access(
+		handle, sDIR, smb_fname,
+		result->d_name,
+		sDIR->base, 0,
+		STRUCTSCANO(handle->data)->hide_nonscanned_files
+		? STRUCTSCANO(handle->data)->recheck_time_readdir
+		: 0,
+		STRUCTSCANO(handle->data)->recheck_tries_readdir,
+		-1,
+		1);
+	DEBUG(SCANNEDONLY_DEBUG,
+	      ("scannedonly_readdir access to %s (%s) = %d\n", tmp,
+	       result->d_name, allowed));
+	if (allowed) {
+		return result;
+	}
+	DEBUG(SCANNEDONLY_DEBUG,
+	      ("hide_nonscanned_files=%d, allow_nonscanned_files=%d\n",
+	       STRUCTSCANO(handle->data)->hide_nonscanned_files,
+	       STRUCTSCANO(handle->data)->allow_nonscanned_files
+		      ));
+
+	if (!STRUCTSCANO(handle->data)->hide_nonscanned_files
+	    || STRUCTSCANO(handle->data)->allow_nonscanned_files) {
+		return result;
+	}
+
+	DEBUG(SCANNEDONLY_DEBUG,
+	      ("scannedonly_readdir, readdir listing for %s not "
+	       "allowed, notify user\n", result->d_name));
+	notify_name = talloc_asprintf(
+		ctx,"%s %s",result->d_name,
+		STRUCTSCANO(handle->data)->scanning_message);
+	namelen = strlen(notify_name);
+	newdirent = (SMB_STRUCT_DIRENT *)TALLOC_ARRAY(
+		ctx, char, sizeof(SMB_STRUCT_DIRENT) + namelen + 1);
+	if (!newdirent) {
+		return NULL;
+	}
+	memcpy(newdirent, result, sizeof(SMB_STRUCT_DIRENT));
+	memcpy(&newdirent->d_name, notify_name, namelen + 1);
+	DEBUG(SCANNEDONLY_DEBUG,
+	      ("scannedonly_readdir, return newdirent at %p with "
+	       "notification %s\n", newdirent, newdirent->d_name));
+	return newdirent;
+}
+
+static void scannedonly_seekdir(struct vfs_handle_struct *handle,
+				SMB_STRUCT_DIR * dirp, long offset)
+{
+	struct scannedonly_DIR *sDIR = (struct scannedonly_DIR *)dirp;
+	SMB_VFS_NEXT_SEEKDIR(handle, sDIR->DIR, offset);
+}
+
+static long scannedonly_telldir(struct vfs_handle_struct *handle,
+				SMB_STRUCT_DIR * dirp)
+{
+	struct scannedonly_DIR *sDIR = (struct scannedonly_DIR *)dirp;
+	return SMB_VFS_NEXT_TELLDIR(handle, sDIR->DIR);
+}
+
+static void scannedonly_rewinddir(struct vfs_handle_struct *handle,
+				  SMB_STRUCT_DIR * dirp)
+{
+	struct scannedonly_DIR *sDIR = (struct scannedonly_DIR *)dirp;
+	SMB_VFS_NEXT_REWINDDIR(handle, sDIR->DIR);
+}
+
+static int scannedonly_closedir(vfs_handle_struct * handle,
+				SMB_STRUCT_DIR * dirp)
+{
+	int retval;
+	struct scannedonly_DIR *sDIR = (struct scannedonly_DIR *)dirp;
+	flush_sendbuffer(handle);
+	retval = SMB_VFS_NEXT_CLOSEDIR(handle, sDIR->DIR);
+	TALLOC_FREE(sDIR);
+	return retval;
+}
+
+static int scannedonly_stat(vfs_handle_struct * handle,
+			    struct smb_filename *smb_fname)
+{
+	int ret;
+	ret = SMB_VFS_NEXT_STAT(handle, smb_fname);
+	DEBUG(SCANNEDONLY_DEBUG, ("scannedonly_stat: %s returned %d\n",
+				  smb_fname->base_name, ret));
+	if (ret != 0 && errno == ENOENT) {
+		TALLOC_CTX *ctx=talloc_tos();
+		char *test_base_name, *tmp_base_name = smb_fname->base_name;
+		/* possibly this was a fake name (file is being scanned for
+		   viruses.txt): check for that and create the real name and
+		   stat the real name */
+		test_base_name = real_path_from_notify_path(
+			ctx,
+			STRUCTSCANO(handle->data),
+			smb_fname->base_name);
+		if (test_base_name) {
+			smb_fname->base_name = test_base_name;
+			ret = SMB_VFS_NEXT_STAT(handle, smb_fname);
+			DEBUG(5, ("_stat: %s returned %d\n",
+				  test_base_name, ret));
+			smb_fname->base_name = tmp_base_name;
+		}
+	}
+	return ret;
+}
+
+static int scannedonly_lstat(vfs_handle_struct * handle,
+			     struct smb_filename *smb_fname)
+{
+	int ret;
+	ret = SMB_VFS_NEXT_LSTAT(handle, smb_fname);
+	DEBUG(SCANNEDONLY_DEBUG, ("scannedonly_lstat: %s returned %d\n",
+				  smb_fname->base_name, ret));
+	if (ret != 0 && errno == ENOENT) {
+		TALLOC_CTX *ctx=talloc_tos();
+		char *test_base_name, *tmp_base_name = smb_fname->base_name;
+		/* possibly this was a fake name (file is being scanned for
+		   viruses.txt): check for that and create the real name and
+		   stat the real name */
+		test_base_name = real_path_from_notify_path(
+			ctx, STRUCTSCANO(handle->data), smb_fname->base_name);
+		if (test_base_name) {
+			smb_fname->base_name = test_base_name;
+			ret = SMB_VFS_NEXT_LSTAT(handle, smb_fname);
+			DEBUG(5, ("_lstat: %s returned %d\n",
+				  test_base_name, ret));
+			smb_fname->base_name = tmp_base_name;
+		}
+	}
+	return ret;
+}
+
+static int scannedonly_open(vfs_handle_struct * handle,
+			    struct smb_filename *smb_fname,
+			    files_struct * fsp, int flags, mode_t mode)
+{
+	const char *base;
+	char *tmp, *shortname;
+	int allowed, write_access = 0;
+	TALLOC_CTX *ctx=talloc_tos();
+	/* if open for writing ignore it */
+	if ((flags & O_ACCMODE) == O_WRONLY) {
+		return SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
+	}
+	if ((flags & O_ACCMODE) == O_RDWR) {
+		write_access = 1;
+	}
+	/* check if this file is scanned already */
+	tmp = strrchr(smb_fname->base_name, '/');
+	if (tmp) {
+		base = talloc_strndup(ctx,smb_fname->base_name,
+				      (tmp - smb_fname->base_name) + 1);
+		shortname = tmp + 1;
+	} else {
+		base = "";
+		shortname = (char *)smb_fname->base_name;
+	}
+	allowed = scannedonly_allow_access(
+		handle, NULL, smb_fname, shortname,
+		base,
+		write_access,
+		STRUCTSCANO(handle->data)->recheck_time_open,
+		STRUCTSCANO(handle->data)->recheck_tries_open,
+		STRUCTSCANO(handle->data)->recheck_size_open,
+		0);
+	flush_sendbuffer(handle);
+	DEBUG(SCANNEDONLY_DEBUG, ("scannedonly_open: allow=%d for %s\n",
+				  allowed, smb_fname->base_name));
+	if (allowed
+	    || STRUCTSCANO(handle->data)->allow_nonscanned_files) {
+		return SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
+	}
+	errno = EACCES;
+	return -1;
+}
+
+static int scannedonly_close(vfs_handle_struct * handle, files_struct * fsp)
+{
+	/* we only have to notify the scanner
+	   for files that were open readwrite or writable. */
+	if (fsp->can_write) {
+		TALLOC_CTX *ctx = talloc_tos();
+		notify_scanner(handle, construct_full_path(
+				       ctx,handle,
+				       fsp->fsp_name->base_name,false));
+		flush_sendbuffer(handle);
+	}
+	return SMB_VFS_NEXT_CLOSE(handle, fsp);
+}
+
+static int scannedonly_rename(vfs_handle_struct * handle,
+			      const struct smb_filename *smb_fname_src,
+			      const struct smb_filename *smb_fname_dst)
+{
+	/* rename the cache file before we pass the actual rename on */
+	struct smb_filename *smb_fname_src_tmp = NULL;
+	struct smb_filename *smb_fname_dst_tmp = NULL;
+	char *cachefile_src, *cachefile_dst;
+	TALLOC_CTX *ctx = talloc_tos();
+
+	/* Setup temporary smb_filename structs. */
+	cachefile_src = cachefile_name_f_fullpath(
+		ctx,
+		smb_fname_src->base_name,
+		STRUCTSCANO(handle->data)->p_scanned);
+	cachefile_dst =	cachefile_name_f_fullpath(
+		ctx,
+		smb_fname_dst->base_name,
+		STRUCTSCANO(handle->data)->p_scanned);
+
+	create_synthetic_smb_fname(ctx, cachefile_src,NULL,NULL,
+				   &smb_fname_src_tmp);
+	create_synthetic_smb_fname(ctx, cachefile_dst,NULL,NULL,
+				   &smb_fname_dst_tmp);
+
+	if (SMB_VFS_NEXT_RENAME(handle, smb_fname_src_tmp, smb_fname_dst_tmp)
+	    != 0) {
+		DEBUG(SCANNEDONLY_DEBUG,
+		      ("failed to rename %s into %s\n", cachefile_src,
+		       cachefile_dst));
+	}
+	return SMB_VFS_NEXT_RENAME(handle, smb_fname_src, smb_fname_dst);
+}
+
+static int scannedonly_unlink(vfs_handle_struct * handle,
+			      const struct smb_filename *smb_fname)
+{
+	/* unlink the 'scanned' file too */
+	struct smb_filename *smb_fname_cache = NULL;
+	char * cachefile;
+	TALLOC_CTX *ctx = talloc_tos();
+
+	cachefile = cachefile_name_f_fullpath(
+		ctx,
+		smb_fname->base_name,
+		STRUCTSCANO(handle->data)->p_scanned);
+	create_synthetic_smb_fname(ctx, cachefile,NULL,NULL,
+				   &smb_fname_cache);
+	if (SMB_VFS_NEXT_UNLINK(handle, smb_fname_cache) != 0) {
+		DEBUG(SCANNEDONLY_DEBUG, ("_unlink: failed to unlink %s\n",
+					  smb_fname_cache->base_name));
+	}
+	return SMB_VFS_NEXT_UNLINK(handle, smb_fname);
+}
+
+static int scannedonly_rmdir(vfs_handle_struct * handle, const char *path)
+{
+	/* if there are only .scanned: .virus: or .failed: files, we delete
+	   those, because the client cannot see them */
+	DIR *dirp;
+	SMB_STRUCT_DIRENT *dire;
+	TALLOC_CTX *ctx = talloc_tos();
+	bool only_deletable_files = true, have_files = false;
+	char *path_w_slash;
+
+	if (!STRUCTSCANO(handle->data)->rm_hidden_files_on_rmdir)
+		return SMB_VFS_NEXT_RMDIR(handle, path);
+
+	path_w_slash = name_w_ending_slash(ctx,path);
+	dirp = SMB_VFS_NEXT_OPENDIR(handle, path, NULL, 0);
+	while ((dire = SMB_VFS_NEXT_READDIR(handle, dirp, NULL)) != NULL) {
+		if (ISDOT(dire->d_name) || ISDOTDOT(dire->d_name)) {
+			continue;
+		}
+		have_files = true;
+		if (!is_scannedonly_file(STRUCTSCANO(handle->data),
+					 dire->d_name)) {
+			struct smb_filename *smb_fname = NULL;
+			char *fullpath;
+			int retval;
+
+			if (STRUCTSCANO(handle->data)->show_special_files) {
+				only_deletable_files = false;
+				break;
+			}
+			/* stat the file and see if it is a
+			   special file */
+			fullpath = path_plus_name(ctx,path_w_slash,
+						  dire->d_name);
+			create_synthetic_smb_fname(ctx, fullpath,NULL,NULL,
+						   &smb_fname);
+			retval = SMB_VFS_NEXT_STAT(handle, smb_fname);
+			if (retval == 0
+			    && S_ISREG(smb_fname->st.st_ex_mode)) {
+				only_deletable_files = false;
+			}
+			TALLOC_FREE(fullpath);
+			TALLOC_FREE(smb_fname);
+			break;
+		}
+	}
+	DEBUG(SCANNEDONLY_DEBUG,
+	      ("path=%s, have_files=%d, only_deletable_files=%d\n",
+	       path, have_files, only_deletable_files));
+	if (have_files && only_deletable_files) {
+		DEBUG(SCANNEDONLY_DEBUG,
+		      ("scannedonly_rmdir, remove leftover scannedonly "
+		       "files from %s\n", path_w_slash));
+		SMB_VFS_NEXT_REWINDDIR(handle, dirp);
+		while ((dire = SMB_VFS_NEXT_READDIR(handle, dirp, NULL))
+		       != NULL) {
+			char *fullpath;
+			struct smb_filename *smb_fname = NULL;
+			if (ISDOT(dire->d_name) || ISDOTDOT(dire->d_name)) {
+				continue;
+			}
+			fullpath = path_plus_name(ctx,path_w_slash,
+						  dire->d_name);
+			create_synthetic_smb_fname(ctx, fullpath,NULL,NULL,
+						   &smb_fname);
+			DEBUG(SCANNEDONLY_DEBUG, ("unlink %s\n", fullpath));
+			SMB_VFS_NEXT_UNLINK(handle, smb_fname);
+			TALLOC_FREE(fullpath);
+			TALLOC_FREE(smb_fname);
+		}
+	}
+	return SMB_VFS_NEXT_CLOSEDIR(handle, dirp);
+}
+
+static void free_scannedonly_data(void **data)
+{
+	SAFE_FREE(*data);
+}
+
+static int scannedonly_connect(struct vfs_handle_struct *handle,
+			       const char *service, const char *user)
+{
+
+	struct Tscannedonly *so;
+
+	so = SMB_MALLOC_P(struct Tscannedonly);
+	handle->data = (void *)so;
+	handle->free_data = free_scannedonly_data;
+	so->gsendbuffer[0]='\0';
+	so->domain_socket =
+		lp_parm_bool(SNUM(handle->conn), "scannedonly",
+			     "domain_socket", True);
+	so->socketname =
+		(char *)lp_parm_const_string(SNUM(handle->conn),
+					     "scannedonly", "socketname",
+					     "/var/lib/scannedonly/scan");
+	so->portnum =
+		lp_parm_int(SNUM(handle->conn), "scannedonly", "portnum",
+			    2020);
+	so->scanhost =
+		(char *)lp_parm_const_string(SNUM(handle->conn),
+					     "scannedonly", "scanhost",
+					     "localhost");
+
+	so->show_special_files =
+		lp_parm_bool(SNUM(handle->conn), "scannedonly",
+			     "show_special_files", True);
+	so->rm_hidden_files_on_rmdir =
+		lp_parm_bool(SNUM(handle->conn), "scannedonly",
+			     "rm_hidden_files_on_rmdir", True);
+	so->hide_nonscanned_files =
+		lp_parm_bool(SNUM(handle->conn), "scannedonly",
+			     "hide_nonscanned_files", False);
+	so->allow_nonscanned_files =
+		lp_parm_bool(SNUM(handle->conn), "scannedonly",
+			     "allow_nonscanned_files", False);
+	so->scanning_message =
+		(char *)lp_parm_const_string(SNUM(handle->conn),
+					     "scannedonly",
+					     "scanning_message",
+					     "is being scanned for viruses");
+	so->scanning_message_len = strlen(so->scanning_message);
+	so->recheck_time_open =
+		lp_parm_int(SNUM(handle->conn), "scannedonly",
+			    "recheck_time_open", 50);
+	so->recheck_tries_open =
+		lp_parm_int(SNUM(handle->conn), "scannedonly",
+			    "recheck_tries_open", 100);
+	so->recheck_size_open =
+		lp_parm_int(SNUM(handle->conn), "scannedonly",
+			    "recheck_size_open", 100);
+	so->recheck_time_readdir =
+		lp_parm_int(SNUM(handle->conn), "scannedonly",
+			    "recheck_time_readdir", 50);
+	so->recheck_tries_readdir =
+		lp_parm_int(SNUM(handle->conn), "scannedonly",
+			    "recheck_tries_readdir", 20);
+
+	so->p_scanned =
+		(char *)lp_parm_const_string(SNUM(handle->conn),
+					     "scannedonly",
+					     "pref_scanned",
+					     ".scanned:");
+	so->p_virus =
+		(char *)lp_parm_const_string(SNUM(handle->conn),
+					     "scannedonly",
+					     "pref_virus",
+					     ".virus:");
+	so->p_failed =
+		(char *)lp_parm_const_string(SNUM(handle->conn),
+					     "scannedonly",
+					     "pref_failed",
+					     ".failed:");
+	connect_to_scanner(handle);
+
+	return SMB_VFS_NEXT_CONNECT(handle, service, user);
+}
+
+/* VFS operations structure */
+static struct vfs_fn_pointers vfs_scannedonly_fns = {
+	.opendir = scannedonly_opendir,
+	.readdir = scannedonly_readdir,
+	.seekdir = scannedonly_seekdir,
+	.telldir = scannedonly_telldir,
+	.rewind_dir = scannedonly_rewinddir,
+	.closedir = scannedonly_closedir,
+	.rmdir = scannedonly_rmdir,
+	.stat = scannedonly_stat,
+	.lstat = scannedonly_lstat,
+	.open = scannedonly_open,
+	.close_fn = scannedonly_close,
+	.rename = scannedonly_rename,
+	.unlink = scannedonly_unlink,
+	.connect_fn = scannedonly_connect
+};
+
+NTSTATUS vfs_scannedonly_init(void)
+{
+	return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "scannedonly",
+				&vfs_scannedonly_fns);
+}