nfs4: Forbid accessing multiple NFS4 filesystems from one local mount

Haiku assumes that a pair dev_t:ino_t uniquely identifies a file. That may not be the case if we allow multiple filesystems share one dev_t.

src/add-ons/kernel/file_systems/nfs4/Filehandle.h

@@ -44,6 +44,14 @@ struct FileInfo {
 	inline	FileInfo&	operator=(const FileInfo& fi);
 };
 
+struct FilesystemId {
+			uint64		fMajor;
+			uint64		fMinor;
+
+	inline	bool		operator==(const FilesystemId& fsid) const;
+	inline	bool		operator!=(const FilesystemId& fsid) const;
+};
+
 
 inline
 Filehandle::Filehandle()
@@ -118,5 +126,19 @@ FileInfo::operator=(const FileInfo& fi)
 }
 
 
+inline bool
+FilesystemId::operator==(const FilesystemId& fsid) const
+{
+	return fMajor == fsid.fMajor && fMinor == fsid.fMinor;
+}
+
+
+inline bool
+FilesystemId::operator!=(const FilesystemId& fsid) const
+{
+	return !operator==(fsid);
+}
+
+
 #endif	// FILEHANDLE_H
 

src/add-ons/kernel/file_systems/nfs4/Filesystem.cpp

@@ -63,6 +63,9 @@ Filesystem::Mount(Filesystem** pfs, RPC::Server* serv, const char* fsPath,
 	req.GetFH();
 	req.Access();
 
+	Attribute attr[] = { FATTR4_FSID };
+	req.GetAttr(attr, sizeof(attr) / sizeof(Attribute));
+
 	status_t result = request.Send();
 	if (result != B_OK)
 		return result;
@@ -92,11 +95,22 @@ Filesystem::Mount(Filesystem** pfs, RPC::Server* serv, const char* fsPath,
 				!= (ACCESS4_READ | ACCESS4_LOOKUP))
 		return B_PERMISSION_DENIED;
 
+	AttrValue* values;
+	uint32 count;
+	result = reply.GetAttr(&values, &count);
+	if (result != B_OK || count < 1)
+		return result;
+
+	// FATTR4_FSID is mandatory
+	FilesystemId* fsid =
+		reinterpret_cast<FilesystemId*>(values[0].fData.fPointer);
+
 	Filesystem* fs = new(std::nothrow) Filesystem;
 	fs->fPath = strdup(fsPath);
 	memcpy(&fs->fRootFH, &fh, sizeof(Filehandle));
 	fs->fServer = serv;
 	fs->fDevId = id;
+	fs->fFsId = *fsid;
 
 	*pfs = fs;
 

src/add-ons/kernel/file_systems/nfs4/Filesystem.h

@@ -33,6 +33,8 @@ public:
 	inline	RPC::Server*		Server();
 	inline	NFS4Server*			NFSServer();
 
+	inline	const FilesystemId&	FsId() const;
+
 	inline	uint64				AllocFileId();
 
 	inline	dev_t				DevId() const;
@@ -41,6 +43,7 @@ private:
 								Filesystem();
 
 			const char*			fPath;
+			FilesystemId		fFsId;
 
 			Filehandle			fRootFH;
 
@@ -67,6 +70,13 @@ Filesystem::NFSServer()
 }
 
 
+inline const FilesystemId&
+Filesystem::FsId() const
+{
+	return fFsId;
+}
+
+
 inline uint64
 Filesystem::AllocFileId()
 {

src/add-ons/kernel/file_systems/nfs4/Inode.cpp

@@ -42,7 +42,7 @@ Inode::CreateInode(Filesystem* fs, const FileInfo &fi, Inode** _inode)
 
 		req.PutFH(inode->fHandle);
 
-		Attribute attr[] = { FATTR4_TYPE, FATTR4_FILEID };
+		Attribute attr[] = { FATTR4_TYPE, FATTR4_FSID, FATTR4_FILEID };
 		req.GetAttr(attr, sizeof(attr) / sizeof(Attribute));
 
 		status_t result = request.Send();
@@ -64,20 +64,28 @@ Inode::CreateInode(Filesystem* fs, const FileInfo &fi, Inode** _inode)
 		AttrValue* values;
 		uint32 count;
 		result = reply.GetAttr(&values, &count);
-		if (result != B_OK || count < 1)
+		if (result != B_OK || count < 2)
 			return result;
 
 		if (fi.fFileId == 0) {
-			if (count < 2 || values[1].fAttribute != FATTR4_FILEID)
+			if (count < 3 || values[2].fAttribute != FATTR4_FILEID)
 				inode->fFileId = fs->AllocFileId();
 			else
-				inode->fFileId = values[1].fData.fValue64;
+				inode->fFileId = values[2].fData.fValue64;
 		} else
 			inode->fFileId = fi.fFileId;
 
 		// FATTR4_TYPE is mandatory
 		inode->fType = values[0].fData.fValue32;
 
+		// FATTR4_FSID is mandatory
+		FilesystemId* fsid =
+			reinterpret_cast<FilesystemId*>(values[1].fData.fPointer);
+		if (*fsid != fs->FsId()) {
+			delete[] values;
+			return B_ENTRY_NOT_FOUND;
+		}
+
 		delete[] values;
 
 		*_inode = inode;
@@ -117,7 +125,7 @@ Inode::LookUp(const char* name, ino_t* id)
 
 		req.GetFH();
 
-		Attribute attr[] = { FATTR4_FILEID };
+		Attribute attr[] = { FATTR4_FSID, FATTR4_FILEID };
 		req.GetAttr(attr, sizeof(attr) / sizeof(Attribute));
 
 		status_t result = request.Send();
@@ -154,11 +162,19 @@ Inode::LookUp(const char* name, ino_t* id)
 		if (result != B_OK)
 			return result;
 
+		// FATTR4_FSID is mandatory
+		FilesystemId* fsid =
+			reinterpret_cast<FilesystemId*>(values[0].fData.fPointer);
+		if (*fsid != fFilesystem->FsId()) {
+			delete[] values;
+			return B_ENTRY_NOT_FOUND;
+		}
+
 		uint64 fileId;
-		if (count < 1 || values[0].fAttribute != FATTR4_FILEID)
+		if (count < 2 || values[1].fAttribute != FATTR4_FILEID)
 			fileId = fFilesystem->AllocFileId();
 		else
-			fileId = values[0].fData.fValue64;
+			fileId = values[1].fData.fValue64;
 		delete[] values;
 
 		*id = _FileIdToInoT(fileId);
@@ -646,7 +662,7 @@ Inode::_ReadDirOnce(DirEntry** dirents, uint32* count, uint64* cookie,
 
 		req.PutFH(fHandle);
 
-		Attribute attr[] = { FATTR4_FILEID };
+		Attribute attr[] = { FATTR4_FSID, FATTR4_FILEID };
 		req.ReadDir(*count, cookie, attr, sizeof(attr) / sizeof(Attribute));
 
 		status_t result = request.Send();
@@ -797,9 +813,15 @@ Inode::ReadDir(void* _buffer, uint32 size, uint32* _count, uint64* cookie)
 		for (i = 0; i < min_c(this_count, *_count - count); i++) {
 			struct dirent* de = reinterpret_cast<dirent*>(buffer + pos);
 
+			// FATTR4_FSID is mandatory
+			void* data = dirents[i].fAttrs[0].fData.fPointer;
+			FilesystemId* fsid = reinterpret_cast<FilesystemId*>(data);
+			if (*fsid != fFilesystem->FsId())
+				continue;
+
 			ino_t id;
-			if (dirents[i].fAttrCount == 1)
+			if (dirents[i].fAttrCount == 2)
-				id = _FileIdToInoT(dirents[i].fAttrs[0].fData.fValue64);
+				id = _FileIdToInoT(dirents[i].fAttrs[1].fData.fValue64);
 			else
 				id = _FileIdToInoT(fFilesystem->AllocFileId());
 

src/add-ons/kernel/file_systems/nfs4/ReplyInterpreter.cpp

@@ -337,6 +337,18 @@ ReplyInterpreter::_DecodeAttrs(XDR::ReadStream& str, AttrValue** attrs,
 		current++;
 	}
 
+	if (sIsAttrSet(FATTR4_FSID, bitmap, bcount)) {
+		values[current].fAttribute = FATTR4_FSID;
+		values[current].fFreePointer = true;
+
+		FilesystemId fsid;
+		fsid.fMajor = stream.GetUHyper();
+		fsid.fMinor = stream.GetUHyper();
+		
+		values[current].fData.fPointer = new FilesystemId(fsid);
+		current++;
+	}
+
 	if (sIsAttrSet(FATTR4_LEASE_TIME, bitmap, bcount)) {
 		values[current].fAttribute = FATTR4_LEASE_TIME;
 		values[current].fData.fValue32 = stream.GetUInt();