1 files changed, 0 insertions, 166 deletions
diff --git a/pkg/flipcall/packet_window_allocator.go b/pkg/flipcall/packet_window_allocator.go
deleted file mode 100644
index ccb918fab..000000000
--- a/pkg/flipcall/packet_window_allocator.go
+++ /dev/null
@@ -1,166 +0,0 @@
-// Copyright 2019 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.
-
-package flipcall
-
-import (
-	"fmt"
-	"math/bits"
-	"os"
-	"syscall"
-
-	"gvisor.dev/gvisor/pkg/abi/linux"
-	"gvisor.dev/gvisor/pkg/memutil"
-)
-
-var (
-	pageSize = os.Getpagesize()
-	pageMask = pageSize - 1
-)
-
-func init() {
-	if bits.OnesCount(uint(pageSize)) != 1 {
-		// This is depended on by roundUpToPage().
-		panic(fmt.Sprintf("system page size (%d) is not a power of 2", pageSize))
-	}
-	if uintptr(pageSize) < PacketHeaderBytes {
-		// This is required since Endpoint.Init() imposes a minimum packet
-		// window size of 1 page.
-		panic(fmt.Sprintf("system page size (%d) is less than packet header size (%d)", pageSize, PacketHeaderBytes))
-	}
-}
-
-// PacketWindowDescriptor represents a packet window, a range of pages in a
-// shared memory file that is used to exchange packets between partner
-// Endpoints.
-type PacketWindowDescriptor struct {
-	// FD is the file descriptor representing the shared memory file.
-	FD int
-
-	// Offset is the offset into the shared memory file at which the packet
-	// window begins.
-	Offset int64
-
-	// Length is the size of the packet window in bytes.
-	Length int
-}
-
-// PacketWindowLengthForDataCap returns the minimum packet window size required
-// to accommodate datagrams of the given size in bytes.
-func PacketWindowLengthForDataCap(dataCap uint32) int {
-	return roundUpToPage(int(dataCap) + int(PacketHeaderBytes))
-}
-
-func roundUpToPage(x int) int {
-	return (x + pageMask) &^ pageMask
-}
-
-// A PacketWindowAllocator owns a shared memory file, and allocates packet
-// windows from it.
-type PacketWindowAllocator struct {
-	fd        int
-	nextAlloc int64
-	fileSize  int64
-}
-
-// Init must be called on zero-value PacketWindowAllocators before first use.
-// If it succeeds, Destroy() must be called once the PacketWindowAllocator is
-// no longer in use.
-func (pwa *PacketWindowAllocator) Init() error {
-	fd, err := memutil.CreateMemFD("flipcall_packet_windows", linux.MFD_CLOEXEC|linux.MFD_ALLOW_SEALING)
-	if err != nil {
-		return fmt.Errorf("failed to create memfd: %v", err)
-	}
-	// Apply F_SEAL_SHRINK to prevent either party from causing SIGBUS in the
-	// other by truncating the file, and F_SEAL_SEAL to prevent either party
-	// from applying F_SEAL_GROW or F_SEAL_WRITE.
-	if _, _, e := syscall.RawSyscall(syscall.SYS_FCNTL, uintptr(fd), linux.F_ADD_SEALS, linux.F_SEAL_SHRINK|linux.F_SEAL_SEAL); e != 0 {
-		syscall.Close(fd)
-		return fmt.Errorf("failed to apply memfd seals: %v", e)
-	}
-	pwa.fd = fd
-	return nil
-}
-
-// NewPacketWindowAllocator is a convenience function that returns an
-// initialized PacketWindowAllocator allocated on the heap.
-func NewPacketWindowAllocator() (*PacketWindowAllocator, error) {
-	var pwa PacketWindowAllocator
-	if err := pwa.Init(); err != nil {
-		return nil, err
-	}
-	return &pwa, nil
-}
-
-// Destroy releases resources owned by pwa. This invalidates file descriptors
-// previously returned by pwa.FD() and pwd.Allocate().
-func (pwa *PacketWindowAllocator) Destroy() {
-	syscall.Close(pwa.fd)
-}
-
-// FD represents the file descriptor of the shared memory file backing pwa.
-func (pwa *PacketWindowAllocator) FD() int {
-	return pwa.fd
-}
-
-// Allocate allocates a new packet window of at least the given size and
-// returns a PacketWindowDescriptor representing it.
-//
-// Preconditions: size > 0.
-func (pwa *PacketWindowAllocator) Allocate(size int) (PacketWindowDescriptor, error) {
-	if size <= 0 {
-		return PacketWindowDescriptor{}, fmt.Errorf("invalid size: %d", size)
-	}
-	// Page-align size to ensure that pwa.nextAlloc remains page-aligned.
-	size = roundUpToPage(size)
-	if size <= 0 {
-		return PacketWindowDescriptor{}, fmt.Errorf("size %d overflows after rounding up to page size", size)
-	}
-	end := pwa.nextAlloc + int64(size) // overflow checked by ensureFileSize
-	if err := pwa.ensureFileSize(end); err != nil {
-		return PacketWindowDescriptor{}, err
-	}
-	start := pwa.nextAlloc
-	pwa.nextAlloc = end
-	return PacketWindowDescriptor{
-		FD:     pwa.fd,
-		Offset: start,
-		Length: size,
-	}, nil
-}
-
-func (pwa *PacketWindowAllocator) ensureFileSize(min int64) error {
-	if min <= 0 {
-		return fmt.Errorf("file size would overflow")
-	}
-	if pwa.fileSize >= min {
-		return nil
-	}
-	newSize := 2 * pwa.fileSize
-	if newSize == 0 {
-		newSize = int64(pageSize)
-	}
-	for newSize < min {
-		newNewSize := newSize * 2
-		if newNewSize <= 0 {
-			return fmt.Errorf("file size would overflow")
-		}
-		newSize = newNewSize
-	}
-	if err := syscall.Ftruncate(pwa.fd, newSize); err != nil {
-		return fmt.Errorf("ftruncate failed: %v", err)
-	}
-	pwa.fileSize = newSize
-	return nil
-}