From e6c69537b2c73920ec7cbf28cffbdedee1651792 Mon Sep 17 00:00:00 2001 From: Boyuan He Date: Tue, 18 Aug 2020 21:51:06 +0000 Subject: Implement FUSE_MKNOD Fixes #3492 --- pkg/abi/linux/fuse.go | 43 ++++++++++++++++ pkg/sentry/fsimpl/fuse/fusefs.go | 13 +++++ test/fuse/BUILD | 5 ++ test/fuse/linux/BUILD | 14 +++++ test/fuse/linux/mknod_test.cc | 107 +++++++++++++++++++++++++++++++++++++++ 5 files changed, 182 insertions(+) create mode 100644 test/fuse/linux/mknod_test.cc diff --git a/pkg/abi/linux/fuse.go b/pkg/abi/linux/fuse.go index a1b2a2abf..97d960096 100644 --- a/pkg/abi/linux/fuse.go +++ b/pkg/abi/linux/fuse.go @@ -413,3 +413,46 @@ type FUSEReleaseIn struct { // LockOwner is the id of the lock owner if there is one. LockOwner uint64 } + +// FUSEMknodMeta contains all the static fields of FUSEMknodIn, +// which is used for FUSE_MKNOD. +// +// +marshal +type FUSEMknodMeta struct { + // Mode of the inode to create. + Mode uint32 + + // Rdev encodes device major and minor information. + Rdev uint32 + + // Umask is the current file mode creation mask. + Umask uint32 + + _ uint32 +} + +// FUSEMknodIn contains all the arguments sent by the kernel +// to the daemon, to create a new file node. +// +// Dynamically-sized objects cannot be marshalled. +type FUSEMknodIn struct { + marshal.StubMarshallable + + // MknodMeta contains mode, rdev and umash field for FUSE_MKNODS. + MknodMeta FUSEMknodMeta + + // Name is the name of the node to create. + Name string +} + +// MarshalUnsafe serializes r.MknodMeta and r.Name to the dst buffer. +func (r *FUSEMknodIn) MarshalUnsafe(buf []byte) { + r.MknodMeta.MarshalUnsafe(buf[:r.MknodMeta.SizeBytes()]) + copy(buf[r.MknodMeta.SizeBytes():], r.Name) +} + +// SizeBytes is the size of the memory representation of FUSEMknodIn. +// 1 extra byte for null-terminated string. +func (r *FUSEMknodIn) SizeBytes() int { + return r.MknodMeta.SizeBytes() + len(r.Name) + 1 +} diff --git a/pkg/sentry/fsimpl/fuse/fusefs.go b/pkg/sentry/fsimpl/fuse/fusefs.go index b5f05b80b..5cef0b94f 100644 --- a/pkg/sentry/fsimpl/fuse/fusefs.go +++ b/pkg/sentry/fsimpl/fuse/fusefs.go @@ -349,6 +349,19 @@ func (inode) Valid(ctx context.Context) bool { return true } +// NewNode implements kernfs.Inode.NewNode. +func (i *inode) NewNode(ctx context.Context, name string, opts vfs.MknodOptions) (*vfs.Dentry, error) { + in := linux.FUSEMknodIn{ + MknodMeta: linux.FUSEMknodMeta{ + Mode: uint32(opts.Mode), + Rdev: linux.MakeDeviceID(uint16(opts.DevMajor), opts.DevMinor), + Umask: uint32(kernel.TaskFromContext(ctx).FSContext().Umask()), + }, + Name: name, + } + return i.newEntry(ctx, name, opts.Mode.FileType(), linux.FUSE_MKNOD, &in) +} + // newEntry calls FUSE server for entry creation and allocates corresponding entry according to response. // Shared by FUSE_MKNOD, FUSE_MKDIR, FUSE_SYMLINK, FUSE_LINK and FUSE_LOOKUP. func (i *inode) newEntry(ctx context.Context, name string, fileType linux.FileMode, opcode linux.FUSEOpcode, payload marshal.Marshallable) (*vfs.Dentry, error) { diff --git a/test/fuse/BUILD b/test/fuse/BUILD index 53cbadb3c..ff2948eb3 100644 --- a/test/fuse/BUILD +++ b/test/fuse/BUILD @@ -16,3 +16,8 @@ syscall_test( fuse = "True", test = "//test/fuse/linux:release_test", ) + +syscall_test( + fuse = "True", + test = "//test/fuse/linux:mknod_test", +) diff --git a/test/fuse/linux/BUILD b/test/fuse/linux/BUILD index abee1a33c..c0f917606 100644 --- a/test/fuse/linux/BUILD +++ b/test/fuse/linux/BUILD @@ -44,6 +44,20 @@ cc_binary( ], ) +cc_binary( + name = "mknod_test", + testonly = 1, + srcs = ["mknod_test.cc"], + deps = [ + gtest, + ":fuse_base", + "//test/util:fuse_util", + "//test/util:temp_umask", + "//test/util:test_main", + "//test/util:test_util", + ], +) + cc_library( name = "fuse_base", testonly = 1, diff --git a/test/fuse/linux/mknod_test.cc b/test/fuse/linux/mknod_test.cc new file mode 100644 index 000000000..74c74d76b --- /dev/null +++ b/test/fuse/linux/mknod_test.cc @@ -0,0 +1,107 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include "gtest/gtest.h" +#include "test/fuse/linux/fuse_base.h" +#include "test/util/fuse_util.h" +#include "test/util/temp_umask.h" +#include "test/util/test_util.h" + +namespace gvisor { +namespace testing { + +namespace { + +class MknodTest : public FuseTest { + protected: + const std::string test_file_ = "test_file"; + const mode_t perms_ = S_IRWXU | S_IRWXG | S_IRWXO; +}; + +TEST_F(MknodTest, RegularFile) { + const std::string test_file_path = + JoinPath(mount_point_.path().c_str(), test_file_); + const mode_t new_umask = 0077; + + struct fuse_out_header out_header = { + .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_entry_out), + }; + struct fuse_entry_out out_payload = DefaultEntryOut(S_IFREG | perms_, 5); + auto iov_out = FuseGenerateIovecs(out_header, out_payload); + SetServerResponse(FUSE_MKNOD, iov_out); + TempUmask mask(new_umask); + ASSERT_THAT(mknod(test_file_path.c_str(), perms_, 0), SyscallSucceeds()); + + struct fuse_in_header in_header; + struct fuse_mknod_in in_payload; + std::vector actual_file(test_file_.length() + 1); + auto iov_in = FuseGenerateIovecs(in_header, in_payload, actual_file); + GetServerActualRequest(iov_in); + + EXPECT_EQ(in_header.len, + sizeof(in_header) + sizeof(in_payload) + test_file_.length() + 1); + EXPECT_EQ(in_header.opcode, FUSE_MKNOD); + EXPECT_EQ(in_payload.mode & 0777, perms_ & ~new_umask); + EXPECT_EQ(in_payload.umask, new_umask); + EXPECT_EQ(in_payload.rdev, 0); + EXPECT_EQ(std::string(actual_file.data()), test_file_); +} + +TEST_F(MknodTest, FileTypeError) { + const std::string test_file_path = + JoinPath(mount_point_.path().c_str(), test_file_); + + struct fuse_out_header out_header = { + .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_entry_out), + }; + // server return directory instead of regular file should cause an error. + struct fuse_entry_out out_payload = DefaultEntryOut(S_IFDIR | perms_, 5); + auto iov_out = FuseGenerateIovecs(out_header, out_payload); + SetServerResponse(FUSE_MKNOD, iov_out); + ASSERT_THAT(mknod(test_file_path.c_str(), perms_, 0), + SyscallFailsWithErrno(EIO)); + SkipServerActualRequest(); +} + +TEST_F(MknodTest, NodeIDError) { + const std::string test_file_path = + JoinPath(mount_point_.path().c_str(), test_file_); + + struct fuse_out_header out_header = { + .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_entry_out), + }; + struct fuse_entry_out out_payload = + DefaultEntryOut(S_IFREG | perms_, FUSE_ROOT_ID); + auto iov_out = FuseGenerateIovecs(out_header, out_payload); + SetServerResponse(FUSE_MKNOD, iov_out); + ASSERT_THAT(mknod(test_file_path.c_str(), perms_, 0), + SyscallFailsWithErrno(EIO)); + SkipServerActualRequest(); +} + +} // namespace + +} // namespace testing +} // namespace gvisor -- cgit v1.2.3