From 1b1e39d7a1846e9afa9b794c5780a703f4b05211 Mon Sep 17 00:00:00 2001 From: Haibo Xu Date: Thu, 15 Aug 2019 03:11:15 +0000 Subject: Enabling pkg/tcpip/link support on arm64. Signed-off-by: Haibo Xu haibo.xu@arm.com Change-Id: Ib6b4aa2db19032e58bf0395f714e6883caee460a --- pkg/tcpip/link/fdbased/mmap_unsafe.go | 84 +++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 pkg/tcpip/link/fdbased/mmap_unsafe.go (limited to 'pkg/tcpip/link/fdbased/mmap_unsafe.go') diff --git a/pkg/tcpip/link/fdbased/mmap_unsafe.go b/pkg/tcpip/link/fdbased/mmap_unsafe.go new file mode 100644 index 000000000..3894185ae --- /dev/null +++ b/pkg/tcpip/link/fdbased/mmap_unsafe.go @@ -0,0 +1,84 @@ +// 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. + +// +build linux,amd64 linux,arm64 + +package fdbased + +import ( + "fmt" + "sync/atomic" + "syscall" + "unsafe" + + "golang.org/x/sys/unix" +) + +// tPacketHdrlen is the TPACKET_HDRLEN variable defined in . +var tPacketHdrlen = tPacketAlign(unsafe.Sizeof(tPacketHdr{}) + unsafe.Sizeof(syscall.RawSockaddrLinklayer{})) + +// tpStatus returns the frame status field. +// The status is concurrently updated by the kernel as a result we must +// use atomic operations to prevent races. +func (t tPacketHdr) tpStatus() uint32 { + hdr := unsafe.Pointer(&t[0]) + statusPtr := unsafe.Pointer(uintptr(hdr) + uintptr(tpStatusOffset)) + return atomic.LoadUint32((*uint32)(statusPtr)) +} + +// setTPStatus set's the frame status to the provided status. +// The status is concurrently updated by the kernel as a result we must +// use atomic operations to prevent races. +func (t tPacketHdr) setTPStatus(status uint32) { + hdr := unsafe.Pointer(&t[0]) + statusPtr := unsafe.Pointer(uintptr(hdr) + uintptr(tpStatusOffset)) + atomic.StoreUint32((*uint32)(statusPtr), status) +} + +func newPacketMMapDispatcher(fd int, e *endpoint) (linkDispatcher, error) { + d := &packetMMapDispatcher{ + fd: fd, + e: e, + } + pageSize := unix.Getpagesize() + if tpBlockSize%pageSize != 0 { + return nil, fmt.Errorf("tpBlockSize: %d is not page aligned, pagesize: %d", tpBlockSize, pageSize) + } + tReq := tPacketReq{ + tpBlockSize: uint32(tpBlockSize), + tpBlockNR: uint32(tpBlockNR), + tpFrameSize: uint32(tpFrameSize), + tpFrameNR: uint32(tpFrameNR), + } + // Setup PACKET_RX_RING. + if err := setsockopt(d.fd, syscall.SOL_PACKET, syscall.PACKET_RX_RING, unsafe.Pointer(&tReq), unsafe.Sizeof(tReq)); err != nil { + return nil, fmt.Errorf("failed to enable PACKET_RX_RING: %v", err) + } + // Let's mmap the blocks. + sz := tpBlockSize * tpBlockNR + buf, err := syscall.Mmap(d.fd, 0, sz, syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_SHARED) + if err != nil { + return nil, fmt.Errorf("syscall.Mmap(...,0, %v, ...) failed = %v", sz, err) + } + d.ringBuffer = buf + return d, nil +} + +func setsockopt(fd, level, name int, val unsafe.Pointer, vallen uintptr) error { + if _, _, errno := syscall.Syscall6(syscall.SYS_SETSOCKOPT, uintptr(fd), uintptr(level), uintptr(name), uintptr(val), vallen, 0); errno != 0 { + return error(errno) + } + + return nil +} -- cgit v1.2.3