s3:modules: Implement dummy virus scanner that uses filename matching

Bug: https://bugzilla.samba.org/show_bug.cgi?id=14971

Signed-off-by: Pavel Filipenský <pfilipen@redhat.com>
Reviewed-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>

source3/modules/vfs_virusfilter.c

@@ -35,12 +35,14 @@
 
 enum virusfilter_scanner_enum {
 	VIRUSFILTER_SCANNER_CLAMAV,
+	VIRUSFILTER_SCANNER_DUMMY,
 	VIRUSFILTER_SCANNER_FSAV,
 	VIRUSFILTER_SCANNER_SOPHOS
 };
 
 static const struct enum_list scanner_list[] = {
 	{ VIRUSFILTER_SCANNER_CLAMAV,	"clamav" },
+	{ VIRUSFILTER_SCANNER_DUMMY,	"dummy" },
 	{ VIRUSFILTER_SCANNER_FSAV,	"fsav" },
 	{ VIRUSFILTER_SCANNER_SOPHOS,	"sophos" },
 	{ -1,				NULL }
@@ -199,6 +201,7 @@ static int virusfilter_vfs_connect(
 	int snum = SNUM(handle->conn);
 	struct virusfilter_config *config = NULL;
 	const char *exclude_files = NULL;
+	const char *infected_files = NULL;
 	const char *temp_quarantine_dir_mode = NULL;
 	const char *infected_file_command = NULL;
 	const char *scan_error_command = NULL;
@@ -255,6 +258,12 @@ static int virusfilter_vfs_connect(
 		set_namearray(&config->exclude_files, exclude_files);
 	}
 
+	infected_files = lp_parm_const_string(
+		snum, "virusfilter", "infected files", NULL);
+	if (infected_files != NULL) {
+		set_namearray(&config->infected_files, infected_files);
+	}
+
 	config->cache_entry_limit = lp_parm_int(
 		snum, "virusfilter", "cache entry limit", 100);
 
@@ -537,6 +546,9 @@ static int virusfilter_vfs_connect(
 	case VIRUSFILTER_SCANNER_CLAMAV:
 		ret = virusfilter_clamav_init(config);
 		break;
+	case VIRUSFILTER_SCANNER_DUMMY:
+		ret = virusfilter_dummy_init(config);
+		break;
 	default:
 		DBG_ERR("Unhandled scanner %d\n", backend);
 		return -1;

source3/modules/vfs_virusfilter_common.h

@@ -83,6 +83,9 @@ struct virusfilter_config {
 	/* Exclude files */
 	name_compare_entry		*exclude_files;
 
+	/* Infected files */
+	name_compare_entry		*infected_files;
+
 	/* Scan result cache */
 	struct virusfilter_cache	*cache;
 	int				cache_entry_limit;
@@ -149,5 +152,6 @@ struct virusfilter_backend {
 int virusfilter_sophos_init(struct virusfilter_config *config);
 int virusfilter_fsav_init(struct virusfilter_config *config);
 int virusfilter_clamav_init(struct virusfilter_config *config);
+int virusfilter_dummy_init(struct virusfilter_config *config);
 
 #endif /* _VIRUSFILTER_COMMON_H */

source3/modules/vfs_virusfilter_dummy.c

@@ -0,0 +1,58 @@
+/*
+   Samba-VirusFilter VFS modules
+   Dummy scanner with infected files support.
+   Copyright (C) 2022 Pavel Filipenský <pfilipen@redhat.com>
+
+   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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "modules/vfs_virusfilter_utils.h"
+
+static virusfilter_result virusfilter_dummy_scan(
+	struct vfs_handle_struct *handle,
+	struct virusfilter_config *config,
+	const struct files_struct *fsp,
+	char **reportp)
+{
+	bool ok;
+
+	DBG_INFO("Scanning file: %s\n", fsp_str_dbg(fsp));
+	ok = is_in_path(fsp->fsp_name->base_name,
+			config->infected_files,
+			false);
+	return ok ? VIRUSFILTER_RESULT_INFECTED : VIRUSFILTER_RESULT_CLEAN;
+}
+
+static struct virusfilter_backend_fns virusfilter_backend_dummy = {
+	.connect = NULL,
+	.disconnect = NULL,
+	.scan_init = NULL,
+	.scan = virusfilter_dummy_scan,
+	.scan_end = NULL,
+};
+
+int virusfilter_dummy_init(struct virusfilter_config *config)
+{
+	struct virusfilter_backend *backend = NULL;
+
+	backend = talloc_zero(config, struct virusfilter_backend);
+	if (backend == NULL) {
+		return -1;
+	}
+
+	backend->fns = &virusfilter_backend_dummy;
+	backend->name = "dummy";
+	config->backend = backend;
+	return 0;
+}

source3/modules/wscript_build

@@ -591,6 +591,7 @@ bld.SAMBA3_MODULE('vfs_virusfilter',
                  vfs_virusfilter_sophos.c
                  vfs_virusfilter_fsav.c
                  vfs_virusfilter_clamav.c
+                 vfs_virusfilter_dummy.c
                  ''',
                  deps='samba-util VFS_VIRUSFILTER_UTILS',
                  init_function='',