Now external tables are checked against directories list

builds/posix/make.shared.variables

@@ -212,7 +212,7 @@ FBCLASSES_Objects = $(addprefix $(OBJ)/, $(addsuffix .o, $(basename $(FBCLASSES_
 #
 # common/config
 
-FBCONFIG_ClientFiles=config.cpp config_file.cpp
+FBCONFIG_ClientFiles=config.cpp config_file.cpp dir_list.cpp
 FBCONFIG_ServerFiles=
 
 FBCONFIG_Files= $(FBCONFIG_ClientFiles) $(FBCONFIG_ServerFiles)

builds/win32/msvc6/common.dsp

@@ -115,6 +115,10 @@ SOURCE=..\..\..\src\common\config\config_file.cpp
 
 SOURCE=..\..\..\src\jrd\os\win32\config_root.cpp
 # End Source File
+# Begin Source File
+
+SOURCE=..\..\..\src\common\config\dir_list.cpp
+# End Source File
 # End Group
 # Begin Group "OTHER files"
 
@@ -151,6 +155,10 @@ SOURCE=..\..\..\src\common\config\config_impl.h
 
 SOURCE=..\..\..\src\jrd\os\config_root.h
 # End Source File
+# Begin Source File
+
+SOURCE=..\..\..\src\common\config\dir_list.h
+# End Source File
 # End Group
 # End Target
 # End Project

builds/win32/msvc6/common_classic.dsp

@@ -115,6 +115,10 @@ SOURCE=..\..\..\src\common\config\config_file.cpp
 
 SOURCE=..\..\..\src\jrd\os\win32\config_root.cpp
 # End Source File
+# Begin Source File
+
+SOURCE=..\..\..\src\common\config\dir_list.cpp
+# End Source File
 # End Group
 # Begin Group "OTHER files"
 
@@ -151,6 +155,10 @@ SOURCE=..\..\..\src\common\config\config_impl.h
 
 SOURCE=..\..\..\src\jrd\os\config_root.h
 # End Source File
+# Begin Source File
+
+SOURCE=..\..\..\src\common\config\dir_list.h
+# End Source File
 # End Group
 # End Target
 # End Project

src/common/config/dir_list.cpp

@@ -0,0 +1,182 @@
+/*
+ *	PROGRAM:	Client/Server Common Code
+ *	MODULE:		dir_list.cpp
+ *	DESCRIPTION:	Directory listing config file operation
+ *
+ * The contents of this file are subject to the Interbase Public
+ * License Version 1.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy
+ * of the License at http://www.Inprise.com/IPL.html
+ *
+ * Software distributed under the License is distributed on an
+ * "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express
+ * or implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * Created by: Alex Peshkov <AlexPeshkov@users.sourceforge.net>
+ *
+ * All Rights Reserved.
+ * Contributor(s): ______________________________________.
+ */
+
+#include "Firebird.h"
+#include "../common/config/config.h"
+#include "../common/config/dir_list.h"
+#include "../jrd/os/path_utils.h"
+
+#define New FB_NEW(*getDefaultMemoryPool())
+
+ParsedPath::ParsedPath(void) {
+	PathElem = 0;
+	nElem = 0;
+}
+
+ParsedPath::ParsedPath(const Firebird::string & path) {
+	PathElem = 0;
+	Parse(path);
+}
+
+ParsedPath::~ParsedPath() {
+	delete[] PathElem;
+}
+
+void ParsedPath::Parse(const Firebird::string &path) {
+	delete PathElem;
+	nElem = 0;
+	Firebird::string oldpath = path;
+	do {
+		Firebird::string newpath, elem;
+		PathUtils::splitLastComponent(newpath, elem, oldpath);
+		oldpath = newpath;
+		nElem++;
+	} while (oldpath.length() > 0);
+
+	PathElem = New Firebird::string[nElem];
+	oldpath = path;
+	for (int i=nElem; i--; ) {
+		Firebird::string newpath;
+		PathUtils::splitLastComponent(newpath, PathElem[i], oldpath);
+		oldpath = newpath;
+	}
+}
+
+bool ParsedPath::operator==(const char * path) {
+	return (Firebird::string(*this) == Firebird::string(path));
+}
+
+Firebird::string ParsedPath::SubPath(int n) const {
+	Firebird::string rc = "/" + PathElem[0];
+	for (int i=1; i<n; i++) {
+		Firebird::string newpath;
+		PathUtils::concatPath(newpath, rc, PathElem[i]);
+		rc = newpath;
+	}
+	return rc;
+}
+
+ParsedPath::operator Firebird::string() {
+	if (! PathElem)
+		return "";
+	return SubPath(nElem);
+}
+
+bool ParsedPath::Contains(const ParsedPath & pPath) {
+	if (pPath.nElem < nElem) {
+		return false;
+	}
+	int i;
+	for (i=0; i<nElem; i++) {
+		if (! PathUtils::comparePaths(pPath.PathElem[i], PathElem[i])) {
+			return false;
+		}
+	}
+	for (i = nElem + 1; i<=pPath.nElem; i++) {
+		Firebird::string x = pPath.SubPath(i);
+		if (PathUtils::isSymLink(x)) {
+			return false;
+		}
+	}
+	return true;
+}
+
+DirectoryList::DirectoryList() {
+	ConfigDirs = 0;
+	nDirs = 0;
+}
+
+DirectoryList::~DirectoryList() {
+	delete[] ConfigDirs;
+}
+
+void DirectoryList::Initialize(void) {
+	const Firebird::string val = GetConfigString();
+	nDirs = 1;
+	int i;
+	for (i=0; i<val.length(); i++) {
+		if (val[i] == ';') {
+			nDirs++;
+		}
+	}
+	ConfigDirs = New ParsedPath[nDirs];
+	int Last = 0;
+	nDirs = 0;
+	Firebird::string Root = Config::getRootDirectory();
+	for (i=0; i<val.length(); i++) {
+		if (val[i] == ';') {
+			Firebird::string dir = "";
+			if (i > Last) {
+				dir = val.substr(Last, i-Last);
+			}
+			if (PathUtils::isRelative(dir)) {
+				Firebird::string newdir;
+				PathUtils::concatPath(newdir, Root, dir);
+				dir = newdir;
+			}
+			ConfigDirs[nDirs++].Parse(dir);
+			Last = i + 1;
+		}
+	}
+	Firebird::string dir = "";
+	if (i > Last) {
+		dir = val.substr(Last, i-Last);
+	}
+	if (PathUtils::isRelative(dir)) {
+		Firebird::string newdir;
+		PathUtils::concatPath(newdir, Root, dir);
+		dir = newdir;
+	}
+	ConfigDirs[nDirs++].Parse(dir);
+}
+
+bool DirectoryList::IsPathInList(const Firebird::string &path) {
+	if (! ConfigDirs)
+		Initialize();
+
+	// Disable any up-dir(..) references - in case our path_utils
+	// and OS handle paths in slightly different ways,
+	// this is "wonderful" potential hole for hacks
+	// Example of IIS attack attempt:
+	// "GET /scripts/..%252f../winnt/system32/cmd.exe?/c+dir HTTP/1.0"
+	//								(live from apache access log :)
+	if (path.find(PathUtils::up_dir_link) != Firebird::string::npos)
+		return false;
+
+	if (nDirs == 1 && ConfigDirs[0] == "/") // Handle special case - all open
+		return true;
+
+	Firebird::string varpath = path;
+	if (PathUtils::isRelative(path)) {
+		PathUtils::concatPath(varpath, 
+			Firebird::string(Config::getRootDirectory()), path);
+	}
+
+	ParsedPath pPath = path;
+    bool rc = 0;
+    for (int i=0; i<nDirs; i++) {
+		if (ConfigDirs[i].Contains(pPath)) {
+			rc = true;
+			break;
+		}
+	}
+	return rc;
+}

src/common/config/dir_list.h

@@ -0,0 +1,55 @@
+/*
+ *	PROGRAM:	Client/Server Common Code
+ *	MODULE:		dir_list.h
+ *	DESCRIPTION:	Directory listing config file operation
+ *
+ * The contents of this file are subject to the Interbase Public
+ * License Version 1.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy
+ * of the License at http://www.Inprise.com/IPL.html
+ *
+ * Software distributed under the License is distributed on an
+ * "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express
+ * or implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * Created by: Alex Peshkov <AlexPeshkov@users.sourceforge.net>
+ *
+ * All Rights Reserved.
+ * Contributor(s): ______________________________________.
+ */
+
+#ifndef _DIR_LIST_H_
+#define _DIR_LIST_H_
+
+class ParsedPath {
+	Firebird::string * PathElem;
+	int nElem;
+	Firebird::string SubPath(int n) const;
+public:
+	ParsedPath(void);
+	ParsedPath(const Firebird::string & path);
+	~ParsedPath();
+	void Parse(const Firebird::string & path);
+	Firebird::string operator[](int n);
+	operator Firebird::string();
+	bool operator==(const char * path);
+	bool Contains(const ParsedPath & pPath);
+};
+
+class DirectoryList {
+private:
+	ParsedPath * ConfigDirs;
+	int nDirs;
+	void Initialize(void);
+protected:
+	// for various configuration parameters
+	// returns parameter value
+	virtual const Firebird::string GetConfigString(void) = 0;
+public:
+	DirectoryList();
+	~DirectoryList();
+	// Check, whether Path inside this DirectoryList
+	bool IsPathInList(const Firebird::string & Path);
+};
+#endif //	_DIR_LIST_H_	

src/jrd/ext.cpp

@@ -54,7 +54,10 @@
 #include "../jrd/thd_proto.h"
 #include "../jrd/vio_proto.h"
 #include "../jrd/dls_proto.h"
+#include "../common/config/config.h"
+#include "../common/config/dir_list.h"
 
+static IB_FILE *ext_fopen(const char *filename, const char *mode);
 
 extern "C" {
 
@@ -80,7 +83,6 @@ extern "C" {
 
 //static void io_error(EXT, TEXT *, STATUS, SLONG);
 
-
 void EXT_close(RSB rsb)
 {
 /**************************************
@@ -199,10 +201,10 @@ EXT EXT_file(JRD_REL relation, TEXT * file_name, SLONG * description)
 #ifdef WIN_NT
 	if (found_dir)
 	{
-		if (!(file->ext_ifi = (int*) ib_fopen(ib_file_path, FOPEN_TYPE)))
+		if (!(file->ext_ifi = (int*) ext_fopen(ib_file_path, FOPEN_TYPE)))
 		{
 			/* could not open the file as read write attempt as read only */
-    		if (!(file->ext_ifi = (int*) ib_fopen(ib_file_path, FOPEN_READ_ONLY)))
+    		if (!(file->ext_ifi = (int*) ext_fopen(ib_file_path, FOPEN_READ_ONLY)))
 				ERR_post(isc_io_error, 
     					 gds_arg_string, "ib_fopen", 
     					 gds_arg_string,
@@ -215,10 +217,10 @@ EXT EXT_file(JRD_REL relation, TEXT * file_name, SLONG * description)
 	}
 	else
 	{
-		if (!(file->ext_ifi = (int*) ib_fopen(file_name, FOPEN_TYPE)))
+		if (!(file->ext_ifi = (int*) ext_fopen(file_name, FOPEN_TYPE)))
 		{
 			/* could not open the file as read write attempt as read only */
-			if (!(file->ext_ifi = (int*) ib_fopen(file_name, FOPEN_READ_ONLY)))
+			if (!(file->ext_ifi = (int*) ext_fopen(file_name, FOPEN_READ_ONLY)))
 				ERR_post(isc_io_error, 
     					 gds_arg_string, "ib_fopen", 
     					 gds_arg_string,
@@ -231,11 +233,11 @@ EXT EXT_file(JRD_REL relation, TEXT * file_name, SLONG * description)
 	}
 #else
 	if (!(dbb->dbb_flags & DBB_read_only))
-		file->ext_ifi = (int *) ib_fopen(file_name, FOPEN_TYPE);
+		file->ext_ifi = (int *) ext_fopen(file_name, FOPEN_TYPE);
 	if (!(file->ext_ifi))
 	{
 		/* could not open the file as read write attempt as read only */
-		if (!(file->ext_ifi = (int *) ib_fopen(file_name, FOPEN_READ_ONLY)))
+		if (!(file->ext_ifi = (int *) ext_fopen(file_name, FOPEN_READ_ONLY)))
 			ERR_post(isc_io_error,
 					 gds_arg_string, "ib_fopen",
 					 gds_arg_string,
@@ -653,3 +655,16 @@ void EXT_trans_start(JRD_TRA transaction)
 
 
 } // extern "C"
+
+class ExternalFilesDirectoryList : public DirectoryList {
+	virtual const Firebird::string GetConfigString(void) {
+		return Firebird::string(Config::getExternalTablesDirectory());
+	}
+};
+static ExternalFilesDirectoryList iExternalFilesDirectoryList;
+
+static IB_FILE *ext_fopen(const char *filename, const char *mode) {
+	if (! iExternalFilesDirectoryList.IsPathInList(filename))
+		return 0;
+	return ib_fopen(filename, mode);
+}

src/jrd/os/path_utils.h

@@ -17,6 +17,9 @@ public:
 	/// The directory separator for the platform.
 	static const char dir_sep;
 
+	/// String used to point to parent directory
+	static const Firebird::string up_dir_link;
+	
 	/** An abstract base class for iterating through the contents of a directory.
 		Instances of this class are created using the newDirItr method of
 		the PathUtils class.  Each platform implementation is expected to
@@ -69,6 +72,19 @@ public:
 	**/
 	static bool isRelative(const Firebird::string& path);
 	
+	/** isSymLink returns true if the given path is symbolic link, and false if not.
+		Use of this links may provide way to override system security.
+		Example: ln -s /usr/firebird/ExternalTables/mytable /etc/xinet.d/remoteshell
+		and insert desired rows into mytable.
+	**/
+	static bool isSymLink(const Firebird::string& path);
+	
+	/** comparePaths returns true if two given paths
+		point to the same place in FileSystem.
+	**/
+	static bool comparePaths(const Firebird::string& path1, 
+									const Firebird::string& path2);
+	
 	/** Concatinates the two paths given in the second and third parameters,
 		and writes the resulting path into the first parameter.  The
 		two path input arguments (arg 2 and 3) are concatinated in the order

src/jrd/os/posix/path_utils.cpp

@@ -1,10 +1,12 @@
 #include "../jrd/os/path_utils.h"
 #include <sys/types.h>
+#include <sys/stat.h>
 #include <dirent.h>
 
 /// The POSIX implementation of the path_utils abstraction.
 
 const char PathUtils::dir_sep = '/';
+const Firebird::string PathUtils::up_dir_link = "..";
 
 class PosixDirItr : public PathUtils::dir_iterator
 {
@@ -117,3 +119,18 @@ bool PathUtils::isRelative(const Firebird::string& path)
 		return path[0] != dir_sep;
 	return false;
 }
+
+bool PathUtils::isSymLink(const Firebird::string& path)
+{
+	struct stat st, lst;
+	if (stat(path.c_str(), &st) != 0)
+		return false;
+	if (lstat(path.c_str(), &lst) != 0)
+		return false;
+	return st.st_ino != lst.st_ino;
+}
+
+bool PathUtils::comparePaths(const Firebird::string& path1, 
+ 							 const Firebird::string& path2) {
+ 	return path1 == path2;
+}

src/jrd/os/win32/path_utils.cpp

@@ -4,6 +4,7 @@
 /// The Win32 implementation of the path_utils abstraction.
 
 const char PathUtils::dir_sep = '\\';
+const Firebird::string PathUtils::up_dir_link = "..";
 
 class Win32DirItr : public PathUtils::dir_iterator
 {
@@ -117,7 +118,26 @@ void PathUtils::concatPath(Firebird::string& result,
 
 bool PathUtils::isRelative(const Firebird::string& path)
 {
-	if (path.length() > 0)
-		return path[0] != PathUtils::dir_sep;
+	if (path.length() > 0) {
+		char ds = path[0];
+		if (path.length() > 2) {
+			if (path[1] == ':' && 
+				(('A' <= path[0] && path[0] <= 'Z') || 
+				 ('a' <= path[0] && path[0] <= 'z'))) {
+						ds = path[2];
+			}
+		}
+		return ds != PathUtils::dir_sep;
+	}
+	return true;
+}
+
+bool PathUtils::isSymLink(const Firebird::string& path)
+{
 	return false;
 }
+
+bool PathUtils::comparePaths(const Firebird::string& path1, 
+							 const Firebird::string& path2) {
+	return stricmp(path1.c_str(), path2.c_str()) == 0;
+}