diff options
| -rw-r--r-- | pkg/tcpip/link/fdbased/BUILD | 4 | ||||
| -rw-r--r-- | pkg/tcpip/link/fdbased/mmap.go | 179 | ||||
| -rw-r--r-- | pkg/tcpip/link/fdbased/mmap_amd64.go | 194 | ||||
| -rw-r--r-- | pkg/tcpip/link/fdbased/mmap_stub.go | 23 | ||||
| -rw-r--r-- | pkg/tcpip/link/fdbased/mmap_unsafe.go (renamed from pkg/tcpip/link/fdbased/mmap_amd64_unsafe.go) | 2 | ||||
| -rw-r--r-- | pkg/tcpip/link/rawfile/BUILD | 4 | ||||
| -rw-r--r-- | pkg/tcpip/link/rawfile/blockingpoll_arm64.s | 42 | ||||
| -rw-r--r-- | pkg/tcpip/link/rawfile/blockingpoll_noyield_unsafe.go | 31 | ||||
| -rw-r--r-- | pkg/tcpip/link/rawfile/blockingpoll_yield_unsafe.go (renamed from pkg/tcpip/link/rawfile/blockingpoll_amd64_unsafe.go) | 8 |
9 files changed, 284 insertions, 203 deletions
diff --git a/pkg/tcpip/link/fdbased/BUILD b/pkg/tcpip/link/fdbased/BUILD index d786d8fdf..74fbbb896 100644 --- a/pkg/tcpip/link/fdbased/BUILD +++ b/pkg/tcpip/link/fdbased/BUILD @@ -8,8 +8,8 @@ go_library( "endpoint.go", "endpoint_unsafe.go", "mmap.go", - "mmap_amd64.go", - "mmap_amd64_unsafe.go", + "mmap_stub.go", + "mmap_unsafe.go", "packet_dispatchers.go", ], importpath = "gvisor.dev/gvisor/pkg/tcpip/link/fdbased", diff --git a/pkg/tcpip/link/fdbased/mmap.go b/pkg/tcpip/link/fdbased/mmap.go index 2dca173c2..8bfeb97e4 100644 --- a/pkg/tcpip/link/fdbased/mmap.go +++ b/pkg/tcpip/link/fdbased/mmap.go @@ -12,12 +12,183 @@ // See the License for the specific language governing permissions and // limitations under the License. -// +build !linux !amd64 +// +build linux,amd64 linux,arm64 package fdbased -// Stubbed out version for non-linux/non-amd64 platforms. +import ( + "encoding/binary" + "syscall" -func newPacketMMapDispatcher(fd int, e *endpoint) (linkDispatcher, error) { - return nil, nil + "golang.org/x/sys/unix" + "gvisor.dev/gvisor/pkg/tcpip" + "gvisor.dev/gvisor/pkg/tcpip/buffer" + "gvisor.dev/gvisor/pkg/tcpip/header" + "gvisor.dev/gvisor/pkg/tcpip/link/rawfile" +) + +const ( + tPacketAlignment = uintptr(16) + tpStatusKernel = 0 + tpStatusUser = 1 + tpStatusCopy = 2 + tpStatusLosing = 4 +) + +// We overallocate the frame size to accommodate space for the +// TPacketHdr+RawSockAddrLinkLayer+MAC header and any padding. +// +// Memory allocated for the ring buffer: tpBlockSize * tpBlockNR = 2 MiB +// +// NOTE: +// Frames need to be aligned at 16 byte boundaries. +// BlockSize needs to be page aligned. +// +// For details see PACKET_MMAP setting constraints in +// https://www.kernel.org/doc/Documentation/networking/packet_mmap.txt +const ( + tpFrameSize = 65536 + 128 + tpBlockSize = tpFrameSize * 32 + tpBlockNR = 1 + tpFrameNR = (tpBlockSize * tpBlockNR) / tpFrameSize +) + +// tPacketAlign aligns the pointer v at a tPacketAlignment boundary. Direct +// translation of the TPACKET_ALIGN macro in <linux/if_packet.h>. +func tPacketAlign(v uintptr) uintptr { + return (v + tPacketAlignment - 1) & uintptr(^(tPacketAlignment - 1)) +} + +// tPacketReq is the tpacket_req structure as described in +// https://www.kernel.org/doc/Documentation/networking/packet_mmap.txt +type tPacketReq struct { + tpBlockSize uint32 + tpBlockNR uint32 + tpFrameSize uint32 + tpFrameNR uint32 +} + +// tPacketHdr is tpacket_hdr structure as described in <linux/if_packet.h> +type tPacketHdr []byte + +const ( + tpStatusOffset = 0 + tpLenOffset = 8 + tpSnapLenOffset = 12 + tpMacOffset = 16 + tpNetOffset = 18 + tpSecOffset = 20 + tpUSecOffset = 24 +) + +func (t tPacketHdr) tpLen() uint32 { + return binary.LittleEndian.Uint32(t[tpLenOffset:]) +} + +func (t tPacketHdr) tpSnapLen() uint32 { + return binary.LittleEndian.Uint32(t[tpSnapLenOffset:]) +} + +func (t tPacketHdr) tpMac() uint16 { + return binary.LittleEndian.Uint16(t[tpMacOffset:]) +} + +func (t tPacketHdr) tpNet() uint16 { + return binary.LittleEndian.Uint16(t[tpNetOffset:]) +} + +func (t tPacketHdr) tpSec() uint32 { + return binary.LittleEndian.Uint32(t[tpSecOffset:]) +} + +func (t tPacketHdr) tpUSec() uint32 { + return binary.LittleEndian.Uint32(t[tpUSecOffset:]) +} + +func (t tPacketHdr) Payload() []byte { + return t[uint32(t.tpMac()) : uint32(t.tpMac())+t.tpSnapLen()] +} + +// packetMMapDispatcher uses PACKET_RX_RING's to read/dispatch inbound packets. +// See: mmap_amd64_unsafe.go for implementation details. +type packetMMapDispatcher struct { + // fd is the file descriptor used to send and receive packets. + fd int + + // e is the endpoint this dispatcher is attached to. + e *endpoint + + // ringBuffer is only used when PacketMMap dispatcher is used and points + // to the start of the mmapped PACKET_RX_RING buffer. + ringBuffer []byte + + // ringOffset is the current offset into the ring buffer where the next + // inbound packet will be placed by the kernel. + ringOffset int +} + +func (d *packetMMapDispatcher) readMMappedPacket() ([]byte, *tcpip.Error) { + hdr := tPacketHdr(d.ringBuffer[d.ringOffset*tpFrameSize:]) + for hdr.tpStatus()&tpStatusUser == 0 { + event := rawfile.PollEvent{ + FD: int32(d.fd), + Events: unix.POLLIN | unix.POLLERR, + } + if _, errno := rawfile.BlockingPoll(&event, 1, nil); errno != 0 { + if errno == syscall.EINTR { + continue + } + return nil, rawfile.TranslateErrno(errno) + } + if hdr.tpStatus()&tpStatusCopy != 0 { + // This frame is truncated so skip it after flipping the + // buffer to the kernel. + hdr.setTPStatus(tpStatusKernel) + d.ringOffset = (d.ringOffset + 1) % tpFrameNR + hdr = (tPacketHdr)(d.ringBuffer[d.ringOffset*tpFrameSize:]) + continue + } + } + + // Copy out the packet from the mmapped frame to a locally owned buffer. + pkt := make([]byte, hdr.tpSnapLen()) + copy(pkt, hdr.Payload()) + // Release packet to kernel. + hdr.setTPStatus(tpStatusKernel) + d.ringOffset = (d.ringOffset + 1) % tpFrameNR + return pkt, nil +} + +// dispatch reads packets from an mmaped ring buffer and dispatches them to the +// network stack. +func (d *packetMMapDispatcher) dispatch() (bool, *tcpip.Error) { + pkt, err := d.readMMappedPacket() + if err != nil { + return false, err + } + var ( + p tcpip.NetworkProtocolNumber + remote, local tcpip.LinkAddress + ) + if d.e.hdrSize > 0 { + eth := header.Ethernet(pkt) + p = eth.Type() + remote = eth.SourceAddress() + local = eth.DestinationAddress() + } else { + // We don't get any indication of what the packet is, so try to guess + // if it's an IPv4 or IPv6 packet. + switch header.IPVersion(pkt) { + case header.IPv4Version: + p = header.IPv4ProtocolNumber + case header.IPv6Version: + p = header.IPv6ProtocolNumber + default: + return true, nil + } + } + + pkt = pkt[d.e.hdrSize:] + d.e.dispatcher.DeliverNetworkPacket(d.e, remote, local, p, buffer.NewVectorisedView(len(pkt), []buffer.View{buffer.View(pkt)})) + return true, nil } diff --git a/pkg/tcpip/link/fdbased/mmap_amd64.go b/pkg/tcpip/link/fdbased/mmap_amd64.go deleted file mode 100644 index 029f86a18..000000000 --- a/pkg/tcpip/link/fdbased/mmap_amd64.go +++ /dev/null @@ -1,194 +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. - -// +build linux,amd64 - -package fdbased - -import ( - "encoding/binary" - "syscall" - - "golang.org/x/sys/unix" - "gvisor.dev/gvisor/pkg/tcpip" - "gvisor.dev/gvisor/pkg/tcpip/buffer" - "gvisor.dev/gvisor/pkg/tcpip/header" - "gvisor.dev/gvisor/pkg/tcpip/link/rawfile" -) - -const ( - tPacketAlignment = uintptr(16) - tpStatusKernel = 0 - tpStatusUser = 1 - tpStatusCopy = 2 - tpStatusLosing = 4 -) - -// We overallocate the frame size to accommodate space for the -// TPacketHdr+RawSockAddrLinkLayer+MAC header and any padding. -// -// Memory allocated for the ring buffer: tpBlockSize * tpBlockNR = 2 MiB -// -// NOTE: -// Frames need to be aligned at 16 byte boundaries. -// BlockSize needs to be page aligned. -// -// For details see PACKET_MMAP setting constraints in -// https://www.kernel.org/doc/Documentation/networking/packet_mmap.txt -const ( - tpFrameSize = 65536 + 128 - tpBlockSize = tpFrameSize * 32 - tpBlockNR = 1 - tpFrameNR = (tpBlockSize * tpBlockNR) / tpFrameSize -) - -// tPacketAlign aligns the pointer v at a tPacketAlignment boundary. Direct -// translation of the TPACKET_ALIGN macro in <linux/if_packet.h>. -func tPacketAlign(v uintptr) uintptr { - return (v + tPacketAlignment - 1) & uintptr(^(tPacketAlignment - 1)) -} - -// tPacketReq is the tpacket_req structure as described in -// https://www.kernel.org/doc/Documentation/networking/packet_mmap.txt -type tPacketReq struct { - tpBlockSize uint32 - tpBlockNR uint32 - tpFrameSize uint32 - tpFrameNR uint32 -} - -// tPacketHdr is tpacket_hdr structure as described in <linux/if_packet.h> -type tPacketHdr []byte - -const ( - tpStatusOffset = 0 - tpLenOffset = 8 - tpSnapLenOffset = 12 - tpMacOffset = 16 - tpNetOffset = 18 - tpSecOffset = 20 - tpUSecOffset = 24 -) - -func (t tPacketHdr) tpLen() uint32 { - return binary.LittleEndian.Uint32(t[tpLenOffset:]) -} - -func (t tPacketHdr) tpSnapLen() uint32 { - return binary.LittleEndian.Uint32(t[tpSnapLenOffset:]) -} - -func (t tPacketHdr) tpMac() uint16 { - return binary.LittleEndian.Uint16(t[tpMacOffset:]) -} - -func (t tPacketHdr) tpNet() uint16 { - return binary.LittleEndian.Uint16(t[tpNetOffset:]) -} - -func (t tPacketHdr) tpSec() uint32 { - return binary.LittleEndian.Uint32(t[tpSecOffset:]) -} - -func (t tPacketHdr) tpUSec() uint32 { - return binary.LittleEndian.Uint32(t[tpUSecOffset:]) -} - -func (t tPacketHdr) Payload() []byte { - return t[uint32(t.tpMac()) : uint32(t.tpMac())+t.tpSnapLen()] -} - -// packetMMapDispatcher uses PACKET_RX_RING's to read/dispatch inbound packets. -// See: mmap_amd64_unsafe.go for implementation details. -type packetMMapDispatcher struct { - // fd is the file descriptor used to send and receive packets. - fd int - - // e is the endpoint this dispatcher is attached to. - e *endpoint - - // ringBuffer is only used when PacketMMap dispatcher is used and points - // to the start of the mmapped PACKET_RX_RING buffer. - ringBuffer []byte - - // ringOffset is the current offset into the ring buffer where the next - // inbound packet will be placed by the kernel. - ringOffset int -} - -func (d *packetMMapDispatcher) readMMappedPacket() ([]byte, *tcpip.Error) { - hdr := tPacketHdr(d.ringBuffer[d.ringOffset*tpFrameSize:]) - for hdr.tpStatus()&tpStatusUser == 0 { - event := rawfile.PollEvent{ - FD: int32(d.fd), - Events: unix.POLLIN | unix.POLLERR, - } - if _, errno := rawfile.BlockingPoll(&event, 1, nil); errno != 0 { - if errno == syscall.EINTR { - continue - } - return nil, rawfile.TranslateErrno(errno) - } - if hdr.tpStatus()&tpStatusCopy != 0 { - // This frame is truncated so skip it after flipping the - // buffer to the kernel. - hdr.setTPStatus(tpStatusKernel) - d.ringOffset = (d.ringOffset + 1) % tpFrameNR - hdr = (tPacketHdr)(d.ringBuffer[d.ringOffset*tpFrameSize:]) - continue - } - } - - // Copy out the packet from the mmapped frame to a locally owned buffer. - pkt := make([]byte, hdr.tpSnapLen()) - copy(pkt, hdr.Payload()) - // Release packet to kernel. - hdr.setTPStatus(tpStatusKernel) - d.ringOffset = (d.ringOffset + 1) % tpFrameNR - return pkt, nil -} - -// dispatch reads packets from an mmaped ring buffer and dispatches them to the -// network stack. -func (d *packetMMapDispatcher) dispatch() (bool, *tcpip.Error) { - pkt, err := d.readMMappedPacket() - if err != nil { - return false, err - } - var ( - p tcpip.NetworkProtocolNumber - remote, local tcpip.LinkAddress - ) - if d.e.hdrSize > 0 { - eth := header.Ethernet(pkt) - p = eth.Type() - remote = eth.SourceAddress() - local = eth.DestinationAddress() - } else { - // We don't get any indication of what the packet is, so try to guess - // if it's an IPv4 or IPv6 packet. - switch header.IPVersion(pkt) { - case header.IPv4Version: - p = header.IPv4ProtocolNumber - case header.IPv6Version: - p = header.IPv6ProtocolNumber - default: - return true, nil - } - } - - pkt = pkt[d.e.hdrSize:] - d.e.dispatcher.DeliverNetworkPacket(d.e, remote, local, p, buffer.NewVectorisedView(len(pkt), []buffer.View{buffer.View(pkt)})) - return true, nil -} diff --git a/pkg/tcpip/link/fdbased/mmap_stub.go b/pkg/tcpip/link/fdbased/mmap_stub.go new file mode 100644 index 000000000..67be52d67 --- /dev/null +++ b/pkg/tcpip/link/fdbased/mmap_stub.go @@ -0,0 +1,23 @@ +// 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,!arm64 + +package fdbased + +// Stubbed out version for non-linux/non-amd64/non-arm64 platforms. + +func newPacketMMapDispatcher(fd int, e *endpoint) (linkDispatcher, error) { + return nil, nil +} diff --git a/pkg/tcpip/link/fdbased/mmap_amd64_unsafe.go b/pkg/tcpip/link/fdbased/mmap_unsafe.go index 47cb1d1cc..3894185ae 100644 --- a/pkg/tcpip/link/fdbased/mmap_amd64_unsafe.go +++ b/pkg/tcpip/link/fdbased/mmap_unsafe.go @@ -12,7 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. -// +build linux,amd64 +// +build linux,amd64 linux,arm64 package fdbased diff --git a/pkg/tcpip/link/rawfile/BUILD b/pkg/tcpip/link/rawfile/BUILD index 6e3a7a9d7..088eb8a21 100644 --- a/pkg/tcpip/link/rawfile/BUILD +++ b/pkg/tcpip/link/rawfile/BUILD @@ -6,8 +6,10 @@ go_library( name = "rawfile", srcs = [ "blockingpoll_amd64.s", - "blockingpoll_amd64_unsafe.go", + "blockingpoll_arm64.s", + "blockingpoll_noyield_unsafe.go", "blockingpoll_unsafe.go", + "blockingpoll_yield_unsafe.go", "errors.go", "rawfile_unsafe.go", ], diff --git a/pkg/tcpip/link/rawfile/blockingpoll_arm64.s b/pkg/tcpip/link/rawfile/blockingpoll_arm64.s new file mode 100644 index 000000000..b62888b93 --- /dev/null +++ b/pkg/tcpip/link/rawfile/blockingpoll_arm64.s @@ -0,0 +1,42 @@ +// Copyright 2018 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 "textflag.h" + +// BlockingPoll makes the ppoll() syscall while calling the version of +// entersyscall that relinquishes the P so that other Gs can run. This is meant +// to be called in cases when the syscall is expected to block. +// +// func BlockingPoll(fds *PollEvent, nfds int, timeout *syscall.Timespec) (n int, err syscall.Errno) +TEXT ·BlockingPoll(SB),NOSPLIT,$0-40 + BL ·callEntersyscallblock(SB) + MOVD fds+0(FP), R0 + MOVD nfds+8(FP), R1 + MOVD timeout+16(FP), R2 + MOVD $0x0, R3 // sigmask parameter which isn't used here + MOVD $0x49, R8 // SYS_PPOLL + SVC + CMP $0xfffffffffffff001, R0 + BLS ok + MOVD $-1, R1 + MOVD R1, n+24(FP) + NEG R0, R0 + MOVD R0, err+32(FP) + BL ·callExitsyscall(SB) + RET +ok: + MOVD R0, n+24(FP) + MOVD $0, err+32(FP) + BL ·callExitsyscall(SB) + RET diff --git a/pkg/tcpip/link/rawfile/blockingpoll_noyield_unsafe.go b/pkg/tcpip/link/rawfile/blockingpoll_noyield_unsafe.go new file mode 100644 index 000000000..621ab8d29 --- /dev/null +++ b/pkg/tcpip/link/rawfile/blockingpoll_noyield_unsafe.go @@ -0,0 +1,31 @@ +// Copyright 2018 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,!arm64 + +package rawfile + +import ( + "syscall" + "unsafe" +) + +// BlockingPoll is just a stub function that forwards to the ppoll() system call +// on non-amd64 and non-arm64 platforms. +func BlockingPoll(fds *PollEvent, nfds int, timeout *syscall.Timespec) (int, syscall.Errno) { + n, _, e := syscall.Syscall6(syscall.SYS_PPOLL, uintptr(unsafe.Pointer(fds)), + uintptr(nfds), uintptr(unsafe.Pointer(timeout)), 0, 0, 0) + + return int(n), e +} diff --git a/pkg/tcpip/link/rawfile/blockingpoll_amd64_unsafe.go b/pkg/tcpip/link/rawfile/blockingpoll_yield_unsafe.go index 47039a446..dda3b10a6 100644 --- a/pkg/tcpip/link/rawfile/blockingpoll_amd64_unsafe.go +++ b/pkg/tcpip/link/rawfile/blockingpoll_yield_unsafe.go @@ -12,7 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. -// +build linux,amd64 +// +build linux,amd64 linux,arm64 // +build go1.12 // +build !go1.14 @@ -25,6 +25,12 @@ import ( _ "unsafe" // for go:linkname ) +// BlockingPoll on amd64/arm64 makes the ppoll() syscall while calling the +// version of entersyscall that relinquishes the P so that other Gs can +// run. This is meant to be called in cases when the syscall is expected to +// block. On non amd64/arm64 platforms it just forwards to the ppoll() system +// call. +// //go:noescape func BlockingPoll(fds *PollEvent, nfds int, timeout *syscall.Timespec) (int, syscall.Errno) |