vfs/{b|btr|package|b}fs/ext2/exfat: common access check.

* Added VFS helper function check_access_permissions() that combines
  several partially correct versions to the one true version (tm).
* All but BFS (since recently) missed the S_IXOTH for root on directories,
  and all but packagefs missed proper group handling.

headers/os/drivers/fs_interface.h

@@ -1,10 +1,11 @@
 /*
- * Copyright 2004-2010, Haiku Inc. All Rights Reserved.
+ * Copyright 2004-2014, Haiku Inc. All Rights Reserved.
  * Distributed under the terms of the MIT License.
  */
 #ifndef _FS_INTERFACE_H
 #define _FS_INTERFACE_H
 
+
 /*! File System Interface Layer Definition */
 
 
@@ -330,6 +331,8 @@ extern status_t unremove_vnode(fs_volume* volume, ino_t vnodeID);
 extern status_t get_vnode_removed(fs_volume* volume, ino_t vnodeID,
 					bool* _removed);
 extern fs_volume* volume_for_vnode(fs_vnode* vnode);
+extern status_t check_access_permissions(int accessMode, mode_t mode,
+					gid_t nodeGroupID, uid_t nodeUserID);
 
 extern status_t read_pages(int fd, off_t pos, const struct iovec* vecs,
 					size_t count, size_t* _numBytes);

src/add-ons/kernel/file_systems/bfs/Inode.cpp

@@ -506,37 +506,8 @@ Inode::CheckPermissions(int accessMode) const
 	if ((accessMode & W_OK) != 0 && fVolume->IsReadOnly())
 		return B_READ_ONLY_DEVICE;
 
-	// get node permissions
+	return check_access_permissions(accessMode, Mode(), (gid_t)fNode.GroupID(),
-	mode_t mode = Mode();
+		(uid_t)fNode.UserID());
-	int userPermissions = (mode & S_IRWXU) >> 6;
-	int groupPermissions = (mode & S_IRWXG) >> 3;
-	int otherPermissions = mode & S_IRWXO;
-
-	// get the node permissions for this uid/gid
-	int permissions = 0;
-	uid_t uid = geteuid();
-	gid_t gid = getegid();
-
-	if (uid == 0) {
-		// user is root
-		// root has always read/write permission, but at least one of the
-		// X bits must be set for execute permission
-		permissions = userPermissions | groupPermissions | otherPermissions
-			| R_OK | W_OK;
-		if (IsDirectory())
-			permissions |= X_OK;
-	} else if (uid == (uid_t)fNode.UserID()) {
-		// user is node owner
-		permissions = userPermissions;
-	} else if (gid == (gid_t)fNode.GroupID()) {
-		// user is in owning group
-		permissions = groupPermissions;
-	} else {
-		// user is one of the others
-		permissions = otherPermissions;
-	}
-
-	return (accessMode & ~permissions) == 0 ? B_OK : B_NOT_ALLOWED;
 }
 
 

src/add-ons/kernel/file_systems/btrfs/Inode.cpp

@@ -1,6 +1,6 @@
 /*
  * Copyright 2011, Jérôme Duval, korli@users.berlios.de.
- * Copyright 2008, Axel Dörfler, axeld@pinc-software.de.
+ * Copyright 2008-2014, Axel Dörfler, axeld@pinc-software.de.
  * Copyright 2005-2007, Ingo Weinhold, bonefish@cs.tu-berlin.de.
  * This file may be used under the terms of the MIT License.
  */
@@ -104,35 +104,8 @@ Inode::CheckPermissions(int accessMode) const
 	if ((accessMode & W_OK) != 0 && fVolume->IsReadOnly())
 		return B_READ_ONLY_DEVICE;
 
-	// get node permissions
+	return check_access_permissions(accessMode, Mode(), (gid_t)fNode.GroupID(),
-	mode_t mode = Mode();
+		(uid_t)fNode.UserID());
-	int userPermissions = (mode & S_IRWXU) >> 6;
-	int groupPermissions = (mode & S_IRWXG) >> 3;
-	int otherPermissions = mode & S_IRWXO;
-
-	// get the node permissions for this uid/gid
-	int permissions = 0;
-	uid_t uid = geteuid();
-	gid_t gid = getegid();
-
-	if (uid == 0) {
-		// user is root
-		// root has always read/write permission, but at least one of the
-		// X bits must be set for execute permission
-		permissions = userPermissions | groupPermissions | otherPermissions
-			| R_OK | W_OK;
-	} else if (uid == (uid_t)fNode.UserID()) {
-		// user is node owner
-		permissions = userPermissions;
-	} else if (gid == (gid_t)fNode.GroupID()) {
-		// user is in owning group
-		permissions = groupPermissions;
-	} else {
-		// user is one of the others
-		permissions = otherPermissions;
-	}
-
-	return (accessMode & ~permissions) == 0 ? B_OK : B_NOT_ALLOWED;
 }
 
 
@@ -162,12 +135,12 @@ Inode::FindBlock(off_t pos, off_t& physical, off_t *_length)
 		logical = diff + extent_data->disk_offset;
 	else
 		panic("unknown extent type; %d\n", extent_data->Type());
-	status = fVolume->FindBlock(logical, physical);	
+	status = fVolume->FindBlock(logical, physical);
 	if (_length != NULL)
 		*_length = extent_data->Size() - diff;
 	TRACE("Inode::FindBlock(%" B_PRIdINO ") %" B_PRIdOFF " physical %"
 		B_PRIdOFF "\n", ID(), pos, physical);
-	
+
 	free(extent_data);
 	return status;
 }
@@ -180,7 +153,7 @@ Inode::ReadAt(off_t pos, uint8* buffer, size_t* _length)
 
 	// set/check boundaries for pos/length
 	if (pos < 0) {
-		ERROR("inode %" B_PRIdINO ": ReadAt failed(pos %" B_PRIdOFF 
+		ERROR("inode %" B_PRIdINO ": ReadAt failed(pos %" B_PRIdOFF
 			", length %lu)\n", ID(), pos, length);
 		return B_BAD_VALUE;
 	}
@@ -212,7 +185,7 @@ Inode::ReadAt(off_t pos, uint8* buffer, size_t* _length)
 	uint8 compression = extent_data->Compression();
 	if (FileCache() != NULL
 		&& extent_data->Type() == BTRFS_EXTENT_DATA_REGULAR) {
-		TRACE("inode %" B_PRIdINO ": ReadAt cache (pos %" B_PRIdOFF ", length %lu)\n", 
+		TRACE("inode %" B_PRIdINO ": ReadAt cache (pos %" B_PRIdOFF ", length %lu)\n",
 			ID(), pos, length);
 		free(extent_data);
 		if (compression == BTRFS_EXTENT_COMPRESS_NONE)
@@ -313,7 +286,7 @@ Inode::ReadAt(off_t pos, uint8* buffer, size_t* _length)
 		panic("unknown extent compression; %d\n", compression);
 	free(extent_data);
 	return B_OK;
-	
+
 }
 
 
@@ -336,7 +309,7 @@ Inode::FindParent(ino_t *id)
 	*id = search_key.Offset();
 	TRACE("Inode::FindParent() for %" B_PRIdINO ": %" B_PRIdINO "\n", fID,
 		*id);
-	
+
 	return B_OK;
 }
 

src/add-ons/kernel/file_systems/exfat/Inode.cpp

@@ -1,6 +1,6 @@
 /*
  * Copyright 2011, Jérôme Duval, korli@users.berlios.de.
- * Copyright 2008, Axel Dörfler, axeld@pinc-software.de.
+ * Copyright 2008-2014, Axel Dörfler, axeld@pinc-software.de.
  * This file may be used under the terms of the MIT License.
  */
 
@@ -157,36 +157,8 @@ Inode::CheckPermissions(int accessMode) const
 	if ((accessMode & W_OK) != 0 && fVolume->IsReadOnly())
 		return B_READ_ONLY_DEVICE;
 
-	// get node permissions
+	return check_access_permissions(accessMode, Mode(), (gid_t)GroupID(),
-	mode_t mode = Mode();
+		(uid_t)UserID());
-	int userPermissions = (mode & S_IRWXU) >> 6;
-	int groupPermissions = (mode & S_IRWXG) >> 3;
-	int otherPermissions = mode & S_IRWXO;
-
-	// get the node permissions for this uid/gid
-	int permissions = 0;
-	uid_t uid = geteuid();
-	gid_t gid = getegid();
-
-	if (uid == 0) {
-		// user is root
-		// root has always read/write permission, but at least one of the
-		// X bits must be set for execute permission
-		permissions = userPermissions | groupPermissions | otherPermissions
-			| R_OK | W_OK;
-	} else if (uid == (uid_t)UserID()) {
-		// user is node owner
-		permissions = userPermissions;
-	} else if (gid == (gid_t)GroupID()) {
-		// user is in owning group
-		permissions = groupPermissions;
-	} else {
-		// user is one of the others
-		permissions = otherPermissions;
-	}
-
-	return (accessMode & ~permissions) == 0 ? B_OK : B_NOT_ALLOWED;
-	return B_OK;
 }
 
 
@@ -217,7 +189,7 @@ Inode::ReadAt(off_t pos, uint8* buffer, size_t* _length)
 		return B_NO_ERROR;
 	}
 
-	return file_cache_read(FileCache(), NULL, pos, buffer, _length);	
+	return file_cache_read(FileCache(), NULL, pos, buffer, _length);
 }
 
 

src/add-ons/kernel/file_systems/ext2/Inode.cpp

@@ -1,6 +1,6 @@
 /*
  * Copyright 2011, Jérôme Duval, korli@users.berlios.de.
- * Copyright 2008, Axel Dörfler, axeld@pinc-software.de.
+ * Copyright 2008-2014, Axel Dörfler, axeld@pinc-software.de.
  * This file may be used under the terms of the MIT License.
  */
 
@@ -186,35 +186,8 @@ Inode::CheckPermissions(int accessMode) const
 	if ((accessMode & W_OK) != 0 && fVolume->IsReadOnly())
 		return B_READ_ONLY_DEVICE;
 
-	// get node permissions
+	return check_access_permissions(accessMode, Mode(), (gid_t)fNode.GroupID(),
-	mode_t mode = Mode();
+		(uid_t)fNode.UserID());
-	int userPermissions = (mode & S_IRWXU) >> 6;
-	int groupPermissions = (mode & S_IRWXG) >> 3;
-	int otherPermissions = mode & S_IRWXO;
-
-	// get the node permissions for this uid/gid
-	int permissions = 0;
-	uid_t uid = geteuid();
-	gid_t gid = getegid();
-
-	if (uid == 0) {
-		// user is root
-		// root has always read/write permission, but at least one of the
-		// X bits must be set for execute permission
-		permissions = userPermissions | groupPermissions | otherPermissions
-			| R_OK | W_OK;
-	} else if (uid == (uid_t)fNode.UserID()) {
-		// user is node owner
-		permissions = userPermissions;
-	} else if (gid == (gid_t)fNode.GroupID()) {
-		// user is in owning group
-		permissions = groupPermissions;
-	} else {
-		// user is one of the others
-		permissions = otherPermissions;
-	}
-
-	return (accessMode & ~permissions) == 0 ? B_OK : B_NOT_ALLOWED;
 }
 
 

src/add-ons/kernel/file_systems/packagefs/kernel_interface.cpp

@@ -36,20 +36,6 @@ static const uint32 kOptimalIOSize = 64 * 1024;
 // #pragma mark - helper functions
 
 
-static bool
-is_user_in_group(gid_t gid)
-{
-	gid_t groups[NGROUPS_MAX];
-	int groupCount = getgroups(NGROUPS_MAX, groups);
-	for (int i = 0; i < groupCount; i++) {
-		if (gid == groups[i])
-			return true;
-	}
-
-	return (gid == getegid());
-}
-
-
 static status_t
 check_access(Node* node, int mode)
 {
@@ -57,33 +43,8 @@ check_access(Node* node, int mode)
 	if (mode & W_OK)
 		return B_READ_ONLY_DEVICE;
 
-	// get node permissions
+	return check_access_permissions(mode, node->Mode(), node->GroupID(),
-	int userPermissions = (node->Mode() & S_IRWXU) >> 6;
+		node->UserID());
-	int groupPermissions = (node->Mode() & S_IRWXG) >> 3;
-	int otherPermissions = node->Mode() & S_IRWXO;
-
-	// get the permissions for this uid/gid
-	int permissions = 0;
-	uid_t uid = geteuid();
-
-	if (uid == 0) {
-		// user is root
-		// root has always read/write permission, but at least one of the
-		// X bits must be set for execute permission
-		permissions = userPermissions | groupPermissions | otherPermissions
-			| S_IROTH | S_IWOTH;
-	} else if (uid == node->UserID()) {
-		// user is node owner
-		permissions = userPermissions;
-	} else if (is_user_in_group(node->GroupID())) {
-		// user is in owning group
-		permissions = groupPermissions;
-	} else {
-		// user is one of the others
-		permissions = otherPermissions;
-	}
-
-	return (mode & ~permissions) == 0 ? B_OK : B_NOT_ALLOWED;
 }
 
 

src/add-ons/kernel/file_systems/reiserfs/kernel_interface.cpp

@@ -54,9 +54,6 @@ extern fs_volume_ops gReiserFSVolumeOps;
 extern fs_vnode_ops gReiserFSVnodeOps;
 
 
-inline static bool is_user_in_group(gid_t gid);
-
-
 // #pragma mark - FS
 
 
@@ -307,41 +304,19 @@ static status_t
 reiserfs_access(fs_volume *fs, fs_vnode *_node, int mode)
 {
 	TOUCH(fs);
-//	FUNCTION_START();
-//	Volume *volume = (Volume*)fs->private_volume;
 	VNode *node = (VNode*)_node->private_node;
-FUNCTION(("node: (%Ld: %lu, %lu)\n", node->GetID(), node->GetDirID(),
+	FUNCTION(("node: (%Ld: %lu, %lu)\n", node->GetID(), node->GetDirID(),
 		  node->GetObjectID()));
+
 	// write access requested?
 	if (mode & W_OK)
 		return B_READ_ONLY_DEVICE;
+
 	// get node permissions
 	StatData *statData = node->GetStatData();
-	int userPermissions = (statData->GetMode() & S_IRWXU) >> 6;
+
-	int groupPermissions = (statData->GetMode() & S_IRWXG) >> 3;
+	return check_access_permissions(mode, statData->GetMode(),
-	int otherPermissions = statData->GetMode() & S_IRWXO;
+		statData->GetGID(), statData->GetUID());
-	// get the permissions for this uid/gid
-	int permissions = 0;
-	uid_t uid = geteuid();
-	// user is root
-	if (uid == 0) {
-		// root has always read/write permission, but at least one of the
-		// X bits must be set for execute permission
-		permissions = userPermissions | groupPermissions | otherPermissions
-			| S_IROTH | S_IWOTH;
-	// user is node owner
-	} else if (uid == statData->GetUID())
-		permissions = userPermissions;
-	// user is in owning group
-	else if (is_user_in_group(statData->GetGID()))
-		permissions = groupPermissions;
-	// user is one of the others
-	else
-		permissions = otherPermissions;
-	// do the check
-	if (mode & ~permissions)
-		return B_NOT_ALLOWED;
-	return B_OK;
 }
 
 // reiserfs_read_stat
@@ -465,23 +440,7 @@ reiserfs_read(fs_volume *fs, fs_vnode *_node, void *cookie, off_t pos,
 	RETURN_ERROR(error);
 }
 
-// is_user_in_group
-inline static bool
-is_user_in_group(gid_t gid)
-{
-// Either I miss something, or we don't have getgroups() in the kernel. :-(
-/*
-	gid_t groups[NGROUPS_MAX];
-	int groupCount = getgroups(NGROUPS_MAX, groups);
-	for (int i = 0; i < groupCount; i++) {
-		if (gid == groups[i])
-			return true;
-	}
-*/
-	return (gid == getegid());
-}
 
-// DirectoryCookie
 class DirectoryCookie : public DirEntryIterator {
 public:
 	DirectoryCookie(Tree *tree, uint32 dirID, uint32 objectID,

src/system/kernel/fs/vfs.cpp

@@ -1,6 +1,6 @@
 /*
  * Copyright 2005-2013, Ingo Weinhold, ingo_weinhold@gmx.de.
- * Copyright 2002-2011, Axel Dörfler, axeld@pinc-software.de.
+ * Copyright 2002-2014, Axel Dörfler, axeld@pinc-software.de.
  * Distributed under the terms of the MIT License.
  *
  * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
@@ -3591,6 +3591,23 @@ common_file_io_vec_pages(struct vnode* vnode, void* cookie,
 }
 
 
+static bool
+is_user_in_group(gid_t gid)
+{
+	if (gid == getegid())
+		return true;
+
+	gid_t groups[NGROUPS_MAX];
+	int groupCount = getgroups(NGROUPS_MAX, groups);
+	for (int i = 0; i < groupCount; i++) {
+		if (gid == groups[i])
+			return true;
+	}
+
+	return false;
+}
+
+
 //	#pragma mark - public API for file systems
 
 
@@ -3876,6 +3893,42 @@ volume_for_vnode(fs_vnode* _vnode)
 }
 
 
+extern "C" status_t
+check_access_permissions(int accessMode, mode_t mode, gid_t nodeGroupID,
+	uid_t nodeUserID)
+{
+	// get node permissions
+	int userPermissions = (mode & S_IRWXU) >> 6;
+	int groupPermissions = (mode & S_IRWXG) >> 3;
+	int otherPermissions = mode & S_IRWXO;
+
+	// get the node permissions for this uid/gid
+	int permissions = 0;
+	uid_t uid = geteuid();
+
+	if (uid == 0) {
+		// user is root
+		// root has always read/write permission, but at least one of the
+		// X bits must be set for execute permission
+		permissions = userPermissions | groupPermissions | otherPermissions
+			| S_IROTH | S_IWOTH;
+		if (S_ISDIR(mode))
+			permissions |= S_IXOTH;
+	} else if (uid == nodeUserID) {
+		// user is node owner
+		permissions = userPermissions;
+	} else if (is_user_in_group(nodeGroupID)) {
+		// user is in owning group
+		permissions = groupPermissions;
+	} else {
+		// user is one of the others
+		permissions = otherPermissions;
+	}
+
+	return (accessMode & ~permissions) == 0 ? B_OK : B_NOT_ALLOWED;
+}
+
+
 #if 0
 extern "C" status_t
 read_pages(int fd, off_t pos, const iovec* vecs, size_t count,