axeld + bonefish:

Added parameters --start-offset and --end-offset to restrict the
access of the file system to only that part of the given file.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23970 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/tools/fs_shell/Jamfile

@@ -47,6 +47,7 @@ BuildPlatformStaticLibrary <build>fs_shell.a :
 	lock.cpp
 	module.cpp
 	node_monitor.cpp
+	partition_support.cpp
 	path_util.cpp
 	rootfs.cpp
 	sem.cpp

src/tools/fs_shell/fcntl.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2007, Ingo Weinhold, [email protected].de.
+ * Copyright 2007-2008, Ingo Weinhold, ingo_weinhold@gmx.de.
  * Distributed under the terms of the MIT License.
  */
 
@@ -9,6 +9,7 @@
 #include <stdarg.h>
 
 #include "fssh_errno.h"
+#include "partition_support.h"
 #include "stat_util.h"
 
 
@@ -37,19 +38,23 @@ fssh_open(const char *pathname, int oflags, ...)
 
 	// Use the _kern_open() defined in libroot on BeOS incompatible systems.
 	// Required for proper attribute emulation support.
+	int fd;
 	#if __BEOS__
-		return open(pathname, to_platform_open_mode(oflags),
+		fd = open(pathname, to_platform_open_mode(oflags),
 			to_platform_mode(mode));
 	#else
-		int fd = _kern_open(-1, pathname, to_platform_open_mode(oflags),
+		fd = _kern_open(-1, pathname, to_platform_open_mode(oflags),
 			to_platform_mode(mode));
 		if (fd < 0) {
 			fssh_set_errno(fd);
-			return -1;
+			fd = -1;
 		}
 
-		return fd;
 	#endif
+
+	restricted_file_opened(fd);
+
+	return fd;
 }
 
 

src/tools/fs_shell/fssh.cpp

@@ -27,6 +27,7 @@
 #include "fssh_string.h"
 #include "fssh_type_constants.h"
 #include "module.h"
+#include "partition_support.h"
 #include "path_util.h"
 #include "syscalls.h"
 #include "vfs.h"
@@ -1159,8 +1160,11 @@ static void
 print_usage(bool error)
 {
 	fprintf((error ? stderr : stdout),
-		"Usage: %s [-n] <device>\n"
+		"Usage: %s [ --start-offset <startOffset>]\n"
-		"       %s --initialize [-n] <device> <volume name> "
+		"          [ --end-offset <endOffset>] [-n] <device>\n"
+		"       %s [ --start-offset <startOffset>]\n"
+		"          [ --end-offset <endOffset>]\n"
+		"          --initialize [-n] <device> <volume name> "
 			"[ <init parameters> ]\n",
 		sArgv[0], sArgv[0]
 	);
@@ -1193,6 +1197,8 @@ main(int argc, const char* const* argv)
 	const char* device = NULL;
 	const char* volumeName = NULL;
 	const char* initParameters = NULL;
+	fssh_off_t startOffset = 0;
+	fssh_off_t endOffset = -1;
 
 	// eat options
 	int argi = 1;
@@ -1204,6 +1210,14 @@ main(int argc, const char* const* argv)
 			initialize = true;
 		} else if (strcmp(arg, "-n") == 0) {
 			interactive = false;
+		} else if (strcmp(arg, "--start-offset") == 0) {
+			if (argi >= argc)
+				print_usage_and_exit(true);
+			startOffset = atoll(argv[argi++]);
+		} else if (strcmp(arg, "--end-offset") == 0) {
+			if (argi >= argc)
+				print_usage_and_exit(true);
+			endOffset = atoll(argv[argi++]);
 		} else {
 			print_usage_and_exit(true);
 		}
@@ -1247,6 +1261,11 @@ main(int argc, const char* const* argv)
 		return error;
 	}
 
+	// restrict access if requested
+	if (startOffset != 0 || endOffset != -1)
+		add_file_restriction(device, startOffset, endOffset);
+
+
 	// start the action
 	int result;
 	if (initialize) {

src/tools/fs_shell/partition_support.cpp

@@ -0,0 +1,215 @@
+/*
+ * Copyright 2008, Ingo Weinhold, [email protected].
+ * Distributed under the terms of the MIT License.
+ */
+
+#include "compatibility.h"
+
+#include "partition_support.h"
+
+#include <errno.h>
+#include <unistd.h>
+
+#include <list>
+
+#include "fssh_errno.h"
+#include "fssh_stat.h"
+#include "fssh_unistd.h"
+#include "stat_priv.h"
+
+
+namespace FSShell {
+
+
+struct FileRestriction {
+	FileRestriction(fssh_dev_t device, fssh_ino_t node, fssh_off_t startOffset,
+		fssh_off_t endOffset)
+		: device(device),
+		  node(node),
+		  startOffset(startOffset),
+		  endOffset(endOffset)
+	{
+	}
+
+	fssh_dev_t	device;
+	fssh_ino_t	node;
+	fssh_off_t	startOffset;
+	fssh_off_t	endOffset;
+};
+
+
+typedef std::list<FileRestriction*> FileRestrictionList;
+
+static FileRestrictionList sFileRestrictions;
+
+
+static FileRestriction*
+find_file_restriction(fssh_dev_t device, fssh_ino_t node)
+{
+	for (FileRestrictionList::iterator it = sFileRestrictions.begin();
+		it != sFileRestrictions.end();
+		++it) {
+		FileRestriction* restriction = *it;
+		if (restriction->device == device && restriction->node == node)
+			return restriction;
+	}
+
+	return NULL;
+}
+
+
+static FileRestriction*
+find_file_restriction(int fd)
+{
+	struct fssh_stat st;
+	if (unrestricted_fstat(fd, &st) < 0)
+		return NULL;
+
+	return find_file_restriction(st.fssh_st_dev, st.fssh_st_ino);
+}
+
+
+void
+add_file_restriction(const char* fileName, fssh_off_t startOffset,
+	fssh_off_t endOffset)
+{
+	struct fssh_stat st;
+	if (unrestricted_stat(fileName, &st) < 0)
+		return;
+
+	fssh_dev_t device = st.fssh_st_dev;
+	fssh_ino_t node = st.fssh_st_ino;
+
+	FileRestriction* restriction = find_file_restriction(device, node);
+	if (restriction)
+		return;
+
+	if (endOffset < 0)
+		endOffset = st.fssh_st_size;
+
+	restriction = new FileRestriction(device, node, startOffset, endOffset);
+	sFileRestrictions.push_back(restriction);
+}
+
+
+void
+restricted_file_opened(int fd)
+{
+	FileRestriction* restriction = find_file_restriction(fd);
+	if (!restriction)
+		return;
+
+	lseek(fd, restriction->startOffset, SEEK_SET);
+}
+
+
+void
+restricted_file_duped(int oldFD, int newFD)
+{
+}
+
+
+void
+restricted_file_closed(int fd)
+{
+}
+
+
+int
+restricted_file_restrict_io(int fd, fssh_off_t& pos, fssh_off_t size)
+{
+	FileRestriction* restriction = find_file_restriction(fd);
+	if (!restriction)
+		return 0;
+
+	if (pos < 0) {
+		pos = lseek(fd, 0, SEEK_CUR);
+		if (pos < 0)
+			return -1;
+	} else
+		pos += restriction->startOffset;
+
+	if (pos < restriction->startOffset || pos > restriction->endOffset) {
+		fssh_set_errno(B_BAD_VALUE);
+		return -1;
+	}
+
+	fssh_off_t maxSize = restriction->endOffset - pos;
+	if (size > maxSize)
+		size = maxSize;
+
+	return 0;
+}
+
+
+#include <stdio.h>
+void
+restricted_file_restrict_stat(struct fssh_stat* st)
+{
+	FileRestriction* restriction = find_file_restriction(st->fssh_st_dev,
+		st->fssh_st_ino);
+	if (!restriction)
+		return;
+
+printf("restricted_file_restrict_stat(): startOffset: %lld, endOffset: %lld\n",
+restriction->startOffset, restriction->endOffset);
+	st->fssh_st_size = restriction->endOffset - restriction->startOffset;
+}
+
+
+static int
+to_platform_seek_mode(int fsshWhence)
+{
+	switch (fsshWhence) {
+		case FSSH_SEEK_CUR:
+			return SEEK_CUR;
+		case FSSH_SEEK_END:
+			return SEEK_END;
+		case FSSH_SEEK_SET:
+		default:
+			return SEEK_SET;
+	}
+}
+
+
+fssh_off_t
+fssh_lseek(int fd, fssh_off_t offset, int whence)
+{
+	FileRestriction* restriction = find_file_restriction(fd);
+	if (!restriction)
+		return lseek(fd, offset, to_platform_seek_mode(whence));
+
+	fssh_off_t pos;
+
+	switch (whence) {
+		case FSSH_SEEK_CUR:
+		{
+			pos = lseek(fd, 0, SEEK_CUR);
+			if (pos < 0)
+				return pos;
+			pos += offset;
+			break;
+		}
+		case FSSH_SEEK_END:
+			pos = restriction->endOffset + offset;
+			break;
+		case FSSH_SEEK_SET:
+		default:
+			pos = restriction->startOffset + offset;
+			break;
+	}
+
+	if (pos < restriction->startOffset) {
+		fssh_set_errno(B_BAD_VALUE);
+		return -1;
+	}
+
+	pos = lseek(fd, pos, SEEK_SET);
+	if (pos >= 0)
+		pos -= restriction->startOffset;
+
+	return pos;
+}
+
+
+}	// namespace FSShell

src/tools/fs_shell/partition_support.h

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2008, Ingo Weinhold, ingo_weinhold@gmx.de.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _FSSH_PARTITION_SUPPORT_H
+#define _FSSH_PARTITION_SUPPORT_H
+
+#include "fssh_defs.h"
+#include "fssh_stat.h"
+
+
+namespace FSShell {
+
+
+void	add_file_restriction(const char* fileName, fssh_off_t startOffset,
+			fssh_off_t endOffset);
+
+void	restricted_file_opened(int fd);
+void	restricted_file_duped(int oldFD, int newFD);
+void	restricted_file_closed(int fd);
+
+int		restricted_file_restrict_io(int fd, fssh_off_t& pos, fssh_off_t size);
+void	restricted_file_restrict_stat(struct fssh_stat* st);
+
+
+}	// namespace FSShell
+
+
+#endif	// _FSSH_PARTITION_SUPPORT_H

src/tools/fs_shell/stat.cpp

@@ -12,6 +12,8 @@
 #include <sys/stat.h>
 
 #include "fssh_errno.h"
+#include "partition_support.h"
+#include "stat_priv.h"
 #include "stat_util.h"
 
 
@@ -27,14 +29,7 @@ using FSShell::to_platform_mode;
 
 
 int
-fssh_mkdir(const char *path, fssh_mode_t mode)
+FSShell::unrestricted_stat(const char *path, struct fssh_stat *fsshStat)
-{
-	return mkdir(path, to_platform_mode(mode));
-}
-
-
-int
-fssh_stat(const char *path, struct fssh_stat *fsshStat)
 {
 	struct stat st;
 
@@ -58,7 +53,7 @@ fssh_stat(const char *path, struct fssh_stat *fsshStat)
 
 
 int
-fssh_fstat(int fd, struct fssh_stat *fsshStat)
+FSShell::unrestricted_fstat(int fd, struct fssh_stat *fsshStat)
 {
 	struct stat st;
 
@@ -82,7 +77,7 @@ fssh_fstat(int fd, struct fssh_stat *fsshStat)
 
 
 int
-fssh_lstat(const char *path, struct fssh_stat *fsshStat)
+FSShell::unrestricted_lstat(const char *path, struct fssh_stat *fsshStat)
 {
 	struct stat st;
 
@@ -103,3 +98,47 @@ fssh_lstat(const char *path, struct fssh_stat *fsshStat)
 	
 	return 0;
 }
+
+// #pragma mark -
+
+int
+fssh_mkdir(const char *path, fssh_mode_t mode)
+{
+	return mkdir(path, to_platform_mode(mode));
+}
+
+
+int
+fssh_stat(const char *path, struct fssh_stat *fsshStat)
+{
+	if (FSShell::unrestricted_stat(path, fsshStat) < 0)
+		return -1;
+
+	FSShell::restricted_file_restrict_stat(fsshStat);
+
+	return 0;
+}
+
+
+int
+fssh_fstat(int fd, struct fssh_stat *fsshStat)
+{
+	if (FSShell::unrestricted_fstat(fd, fsshStat) < 0)
+		return -1;
+	
+	FSShell::restricted_file_restrict_stat(fsshStat);
+
+	return 0;
+}
+
+
+int
+fssh_lstat(const char *path, struct fssh_stat *fsshStat)
+{
+	if (FSShell::unrestricted_lstat(path, fsshStat) < 0)
+		return -1;
+	
+	FSShell::restricted_file_restrict_stat(fsshStat);
+
+	return 0;
+}

src/tools/fs_shell/stat_priv.h

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2008, Ingo Weinhold, ingo_weinhold@gmx.de.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _FSSH_STAT_PRIV_H
+#define _FSSH_STAT_PRIV_H
+
+#include "fssh_defs.h"
+
+
+namespace FSShell {
+
+int unrestricted_stat(const char *path, struct fssh_stat *fsshStat);
+int unrestricted_fstat(int fd, struct fssh_stat *fsshStat);
+int unrestricted_lstat(const char *path, struct fssh_stat *fsshStat);
+
+}	// namespace FSShell
+
+
+#endif	// _FSSH_STAT_PRIV_H

src/tools/fs_shell/uio.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2007, Ingo Weinhold, bonefish@cs.tu-berlin.de.
+ * Copyright 2007-2008, Ingo Weinhold, bonefish@cs.tu-berlin.de.
  * Distributed under the terms of the MIT License.
  */
 
@@ -12,6 +12,8 @@
 #include <errno.h>
 #include <sys/uio.h>
 
+#include "partition_support.h"
+
 
 static const fssh_size_t kMaxIOVecs = 1024;
 
@@ -41,6 +43,11 @@ fssh_readv(int fd, const struct fssh_iovec *vector, fssh_size_t count)
 	if (!prepare_iovecs(vector, count, systemVecs))
 		return -1;
 
+	fssh_off_t pos = -1;
+	fssh_size_t length = 0;
+	if (FSShell::restricted_file_restrict_io(fd, pos, length) < 0)
+		return -1;
+
 	#if !defined(HAIKU_HOST_PLATFORM_FREEBSD)
 		return readv(fd, systemVecs, count);
 	#else
@@ -57,6 +64,10 @@ fssh_readv_pos(int fd, fssh_off_t pos, const struct fssh_iovec *vec,
 	if (!prepare_iovecs(vec, count, systemVecs))
 		return -1;
 
+	fssh_size_t length = 0;
+	if (FSShell::restricted_file_restrict_io(fd, pos, length) < 0)
+		return -1;
+
 	return readv_pos(fd, pos, systemVecs, count);
 }
 
@@ -68,6 +79,11 @@ fssh_writev(int fd, const struct fssh_iovec *vector, fssh_size_t count)
 	if (!prepare_iovecs(vector, count, systemVecs))
 		return -1;
 
+	fssh_off_t pos = -1;
+	fssh_size_t length = 0;
+	if (FSShell::restricted_file_restrict_io(fd, pos, length) < 0)
+		return -1;
+
 	#if !defined(HAIKU_HOST_PLATFORM_FREEBSD)
 		return writev(fd, systemVecs, count);
 	#else
@@ -84,5 +100,9 @@ fssh_writev_pos(int fd, fssh_off_t pos, const struct fssh_iovec *vec,
 	if (!prepare_iovecs(vec, count, systemVecs))
 		return -1;
 
+	fssh_size_t length = 0;
+	if (FSShell::restricted_file_restrict_io(fd, pos, length) < 0)
+		return -1;
+
 	return writev_pos(fd, pos, systemVecs, count);
 }

src/tools/fs_shell/unistd.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2007, Ingo Weinhold, bonefish@cs.tu-berlin.de.
+ * Copyright 2007-2008, Ingo Weinhold, ingo_weinhold@gmx.de.
  * Distributed under the terms of the MIT License.
  */
 
@@ -15,6 +15,7 @@
 
 #include "fssh_drivers.h"
 #include "fssh_errno.h"
+#include "partition_support.h"
 
 #ifdef __BEOS__
 #	include <Drivers.h>
@@ -86,22 +87,28 @@ fssh_dup(int fd)
 {
 	// Use the _kern_dup() defined in libroot on BeOS incompatible systems.
 	// Required for proper attribute emulation support.
+	int newFD;
 	#if __BEOS__
-		return dup(fd);
+		newFD = dup(fd);
 	#else
-		int result = _kern_dup(fd);
+		newFD = _kern_dup(fd);
-		if (result < 0) {
+		if (newFD < 0) {
-			fssh_set_errno(result);
+			fssh_set_errno(newFD);
-			return -1;
+			newFD = -1;
 		}
-		return result;
 	#endif
+
+	FSShell::restricted_file_duped(fd, newFD);
+
+	return newFD;
 }
 
 
 int
 fssh_close(int fd)
 {
+	FSShell::restricted_file_closed(fd);
+
 	// Use the _kern_close() defined in libroot on BeOS incompatible systems.
 	// Required for proper attribute emulation support.
 	#if __BEOS__
@@ -296,9 +303,16 @@ fssh_ssize_t
 fssh_read(int fd, void *buffer, fssh_size_t count)
 {
 	#if !defined(HAIKU_HOST_PLATFORM_FREEBSD)
+		fssh_off_t pos = -1;
+		if (FSShell::restricted_file_restrict_io(fd, pos, count) < 0)
+			return -1;
 		return read(fd, buffer, count);
 	#else
-		return read_pos(fd, lseek(fd, 0, SEEK_CUR), buffer, count);
+		fssh_ssize_t bytesRead = read_pos(fd, fssh_lseek(fd, 0, FSSH_SEEK_CUR),
+			buffer, count);
+		if (bytesRead > 0)
+			fssh_lseek(fd, bytesRead, FSSH_SEEK_CUR);
+		return bytesRead;
 	#endif
 }
 
@@ -306,6 +320,8 @@ fssh_read(int fd, void *buffer, fssh_size_t count)
 fssh_ssize_t
 fssh_read_pos(int fd, fssh_off_t pos, void *buffer, fssh_size_t count)
 {
+	if (FSShell::restricted_file_restrict_io(fd, pos, count) < 0)
+		return -1;
 	return read_pos(fd, pos, buffer, count);
 }
 
@@ -314,20 +330,33 @@ fssh_ssize_t
 fssh_write(int fd, const void *buffer, fssh_size_t count)
 {
 	#if !defined(HAIKU_HOST_PLATFORM_FREEBSD)
+		fssh_off_t pos = -1;
+		if (FSShell::restricted_file_restrict_io(fd, pos, count) < 0)
+			return -1;
 		return write(fd, buffer, count);
 	#else
-		return write_pos(fd, lseek(fd, 0, SEEK_CUR), buffer, count);
+		fssh_ssize_t written = write_pos(fd, fssh_lseek(fd, 0, FSSH_SEEK_CUR),
+			buffer, count);
+		if (written > 0)
+			fssh_lseek(fd, written, FSSH_SEEK_CUR);
+		return written;
 	#endif
 }
 
 
+#include <stdio.h>
 fssh_ssize_t
 fssh_write_pos(int fd, fssh_off_t pos, const void *buffer, fssh_size_t count)
 {
+	if (FSShell::restricted_file_restrict_io(fd, pos, count) < 0)
+		return -1;
 	return write_pos(fd, pos, buffer, count);
 }
 
 
+// fssh_lseek() -- implemented in partition_support.cpp
+
+
 fssh_gid_t
 fssh_getegid(void)
 {