diff options
Diffstat (limited to 'pkg/tcpip/link')
21 files changed, 252 insertions, 109 deletions
diff --git a/pkg/tcpip/link/fdbased/BUILD b/pkg/tcpip/link/fdbased/BUILD index d971194e6..1d0163823 100644 --- a/pkg/tcpip/link/fdbased/BUILD +++ b/pkg/tcpip/link/fdbased/BUILD @@ -14,7 +14,6 @@ go_library( ], visibility = ["//visibility:public"], deps = [ - "//pkg/iovec", "//pkg/sync", "//pkg/tcpip", "//pkg/tcpip/buffer", diff --git a/pkg/tcpip/link/fdbased/endpoint.go b/pkg/tcpip/link/fdbased/endpoint.go index 735c28da1..e8e716db0 100644 --- a/pkg/tcpip/link/fdbased/endpoint.go +++ b/pkg/tcpip/link/fdbased/endpoint.go @@ -12,6 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. +//go:build linux // +build linux // Package fdbased provides the implemention of data-link layer endpoints @@ -44,7 +45,6 @@ import ( "sync/atomic" "golang.org/x/sys/unix" - "gvisor.dev/gvisor/pkg/iovec" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/buffer" @@ -138,6 +138,20 @@ type endpoint struct { // gsoKind is the supported kind of GSO. gsoKind stack.SupportedGSO + + // maxSyscallHeaderBytes has the same meaning as + // Options.MaxSyscallHeaderBytes. + maxSyscallHeaderBytes uintptr + + // writevMaxIovs is the maximum number of iovecs that may be passed to + // rawfile.NonBlockingWriteIovec, as possibly limited by + // maxSyscallHeaderBytes. (No analogous limit is defined for + // rawfile.NonBlockingSendMMsg, since in that case the maximum number of + // iovecs also depends on the number of mmsghdrs. Instead, if sendBatch + // encounters a packet whose iovec count is limited by + // maxSyscallHeaderBytes, it falls back to writing the packet using writev + // via WritePacket.) + writevMaxIovs int } // Options specify the details about the fd-based endpoint to be created. @@ -186,6 +200,11 @@ type Options struct { // RXChecksumOffload if true, indicates that this endpoints capability // set should include CapabilityRXChecksumOffload. RXChecksumOffload bool + + // If MaxSyscallHeaderBytes is non-zero, it is the maximum number of bytes + // of struct iovec, msghdr, and mmsghdr that may be passed by each host + // system call. + MaxSyscallHeaderBytes int } // fanoutID is used for AF_PACKET based endpoints to enable PACKET_FANOUT @@ -235,14 +254,25 @@ func New(opts *Options) (stack.LinkEndpoint, error) { return nil, fmt.Errorf("opts.FD is empty, at least one FD must be specified") } + if opts.MaxSyscallHeaderBytes < 0 { + return nil, fmt.Errorf("opts.MaxSyscallHeaderBytes is negative") + } + e := &endpoint{ - fds: opts.FDs, - mtu: opts.MTU, - caps: caps, - closed: opts.ClosedFunc, - addr: opts.Address, - hdrSize: hdrSize, - packetDispatchMode: opts.PacketDispatchMode, + fds: opts.FDs, + mtu: opts.MTU, + caps: caps, + closed: opts.ClosedFunc, + addr: opts.Address, + hdrSize: hdrSize, + packetDispatchMode: opts.PacketDispatchMode, + maxSyscallHeaderBytes: uintptr(opts.MaxSyscallHeaderBytes), + writevMaxIovs: rawfile.MaxIovs, + } + if e.maxSyscallHeaderBytes != 0 { + if max := int(e.maxSyscallHeaderBytes / rawfile.SizeofIovec); max < e.writevMaxIovs { + e.writevMaxIovs = max + } } // Increment fanoutID to ensure that we don't re-use the same fanoutID for @@ -470,9 +500,8 @@ func (e *endpoint) WritePacket(r stack.RouteInfo, protocol tcpip.NetworkProtocol e.AddHeader(r.LocalLinkAddress, r.RemoteLinkAddress, protocol, pkt) } - var builder iovec.Builder - fd := e.fds[pkt.Hash%uint32(len(e.fds))] + var vnetHdrBuf []byte if e.gsoKind == stack.HWGSOSupported { vnetHdr := virtioNetHdr{} if pkt.GSOOptions.Type != stack.GSONone { @@ -494,71 +523,123 @@ func (e *endpoint) WritePacket(r stack.RouteInfo, protocol tcpip.NetworkProtocol vnetHdr.gsoSize = pkt.GSOOptions.MSS } } + vnetHdrBuf = vnetHdr.marshal() + } - vnetHdrBuf := vnetHdr.marshal() - builder.Add(vnetHdrBuf) + views := pkt.Views() + numIovecs := len(views) + if len(vnetHdrBuf) != 0 { + numIovecs++ + } + if numIovecs > e.writevMaxIovs { + numIovecs = e.writevMaxIovs } - for _, v := range pkt.Views() { - builder.Add(v) + // Allocate small iovec arrays on the stack. + var iovecsArr [8]unix.Iovec + iovecs := iovecsArr[:0] + if numIovecs > len(iovecsArr) { + iovecs = make([]unix.Iovec, 0, numIovecs) + } + iovecs = rawfile.AppendIovecFromBytes(iovecs, vnetHdrBuf, numIovecs) + for _, v := range views { + iovecs = rawfile.AppendIovecFromBytes(iovecs, v, numIovecs) } - return rawfile.NonBlockingWriteIovec(fd, builder.Build()) + return rawfile.NonBlockingWriteIovec(fd, iovecs) } -func (e *endpoint) sendBatch(batchFD int, batch []*stack.PacketBuffer) (int, tcpip.Error) { +func (e *endpoint) sendBatch(batchFD int, pkts []*stack.PacketBuffer) (int, tcpip.Error) { // Send a batch of packets through batchFD. - mmsgHdrs := make([]rawfile.MMsgHdr, 0, len(batch)) - for _, pkt := range batch { - if e.hdrSize > 0 { - e.AddHeader(pkt.EgressRoute.LocalLinkAddress, pkt.EgressRoute.RemoteLinkAddress, pkt.NetworkProtocolNumber, pkt) - } + mmsgHdrsStorage := make([]rawfile.MMsgHdr, 0, len(pkts)) + packets := 0 + for packets < len(pkts) { + mmsgHdrs := mmsgHdrsStorage + batch := pkts[packets:] + syscallHeaderBytes := uintptr(0) + for _, pkt := range batch { + if e.hdrSize > 0 { + e.AddHeader(pkt.EgressRoute.LocalLinkAddress, pkt.EgressRoute.RemoteLinkAddress, pkt.NetworkProtocolNumber, pkt) + } - var vnetHdrBuf []byte - if e.gsoKind == stack.HWGSOSupported { - vnetHdr := virtioNetHdr{} - if pkt.GSOOptions.Type != stack.GSONone { - vnetHdr.hdrLen = uint16(pkt.HeaderSize()) - if pkt.GSOOptions.NeedsCsum { - vnetHdr.flags = _VIRTIO_NET_HDR_F_NEEDS_CSUM - vnetHdr.csumStart = header.EthernetMinimumSize + pkt.GSOOptions.L3HdrLen - vnetHdr.csumOffset = pkt.GSOOptions.CsumOffset - } - if pkt.GSOOptions.Type != stack.GSONone && uint16(pkt.Data().Size()) > pkt.GSOOptions.MSS { - switch pkt.GSOOptions.Type { - case stack.GSOTCPv4: - vnetHdr.gsoType = _VIRTIO_NET_HDR_GSO_TCPV4 - case stack.GSOTCPv6: - vnetHdr.gsoType = _VIRTIO_NET_HDR_GSO_TCPV6 - default: - panic(fmt.Sprintf("Unknown gso type: %v", pkt.GSOOptions.Type)) + var vnetHdrBuf []byte + if e.gsoKind == stack.HWGSOSupported { + vnetHdr := virtioNetHdr{} + if pkt.GSOOptions.Type != stack.GSONone { + vnetHdr.hdrLen = uint16(pkt.HeaderSize()) + if pkt.GSOOptions.NeedsCsum { + vnetHdr.flags = _VIRTIO_NET_HDR_F_NEEDS_CSUM + vnetHdr.csumStart = header.EthernetMinimumSize + pkt.GSOOptions.L3HdrLen + vnetHdr.csumOffset = pkt.GSOOptions.CsumOffset + } + if pkt.GSOOptions.Type != stack.GSONone && uint16(pkt.Data().Size()) > pkt.GSOOptions.MSS { + switch pkt.GSOOptions.Type { + case stack.GSOTCPv4: + vnetHdr.gsoType = _VIRTIO_NET_HDR_GSO_TCPV4 + case stack.GSOTCPv6: + vnetHdr.gsoType = _VIRTIO_NET_HDR_GSO_TCPV6 + default: + panic(fmt.Sprintf("Unknown gso type: %v", pkt.GSOOptions.Type)) + } + vnetHdr.gsoSize = pkt.GSOOptions.MSS } - vnetHdr.gsoSize = pkt.GSOOptions.MSS } + vnetHdrBuf = vnetHdr.marshal() } - vnetHdrBuf = vnetHdr.marshal() - } - var builder iovec.Builder - builder.Add(vnetHdrBuf) - for _, v := range pkt.Views() { - builder.Add(v) - } - iovecs := builder.Build() + views := pkt.Views() + numIovecs := len(views) + if len(vnetHdrBuf) != 0 { + numIovecs++ + } + if numIovecs > rawfile.MaxIovs { + numIovecs = rawfile.MaxIovs + } + if e.maxSyscallHeaderBytes != 0 { + syscallHeaderBytes += rawfile.SizeofMMsgHdr + uintptr(numIovecs)*rawfile.SizeofIovec + if syscallHeaderBytes > e.maxSyscallHeaderBytes { + // We can't fit this packet into this call to sendmmsg(). + // We could potentially do so if we reduced numIovecs + // further, but this might incur considerable extra + // copying. Leave it to the next batch instead. + break + } + } - var mmsgHdr rawfile.MMsgHdr - mmsgHdr.Msg.Iov = &iovecs[0] - mmsgHdr.Msg.SetIovlen((len(iovecs))) - mmsgHdrs = append(mmsgHdrs, mmsgHdr) - } + // We can't easily allocate iovec arrays on the stack here since + // they will escape this loop iteration via mmsgHdrs. + iovecs := make([]unix.Iovec, 0, numIovecs) + iovecs = rawfile.AppendIovecFromBytes(iovecs, vnetHdrBuf, numIovecs) + for _, v := range views { + iovecs = rawfile.AppendIovecFromBytes(iovecs, v, numIovecs) + } - packets := 0 - for len(mmsgHdrs) > 0 { - sent, err := rawfile.NonBlockingSendMMsg(batchFD, mmsgHdrs) - if err != nil { - return packets, err + var mmsgHdr rawfile.MMsgHdr + mmsgHdr.Msg.Iov = &iovecs[0] + mmsgHdr.Msg.SetIovlen(len(iovecs)) + mmsgHdrs = append(mmsgHdrs, mmsgHdr) + } + + if len(mmsgHdrs) == 0 { + // We can't fit batch[0] into a mmsghdr while staying under + // e.maxSyscallHeaderBytes. Use WritePacket, which will avoid the + // mmsghdr (by using writev) and re-buffer iovecs more aggressively + // if necessary (by using e.writevMaxIovs instead of + // rawfile.MaxIovs). + pkt := batch[0] + if err := e.WritePacket(pkt.EgressRoute, pkt.NetworkProtocolNumber, pkt); err != nil { + return packets, err + } + packets++ + } else { + for len(mmsgHdrs) > 0 { + sent, err := rawfile.NonBlockingSendMMsg(batchFD, mmsgHdrs) + if err != nil { + return packets, err + } + packets += sent + mmsgHdrs = mmsgHdrs[sent:] + } } - packets += sent - mmsgHdrs = mmsgHdrs[sent:] } return packets, nil @@ -676,8 +757,9 @@ func NewInjectable(fd int, mtu uint32, capabilities stack.LinkEndpointCapabiliti unix.SetNonblock(fd, true) return &InjectableEndpoint{endpoint: endpoint{ - fds: []int{fd}, - mtu: mtu, - caps: capabilities, + fds: []int{fd}, + mtu: mtu, + caps: capabilities, + writevMaxIovs: rawfile.MaxIovs, }} } diff --git a/pkg/tcpip/link/fdbased/endpoint_test.go b/pkg/tcpip/link/fdbased/endpoint_test.go index 8aad338b6..eccd21579 100644 --- a/pkg/tcpip/link/fdbased/endpoint_test.go +++ b/pkg/tcpip/link/fdbased/endpoint_test.go @@ -12,6 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. +//go:build linux // +build linux package fdbased diff --git a/pkg/tcpip/link/fdbased/endpoint_unsafe.go b/pkg/tcpip/link/fdbased/endpoint_unsafe.go index df14eaad1..904393faa 100644 --- a/pkg/tcpip/link/fdbased/endpoint_unsafe.go +++ b/pkg/tcpip/link/fdbased/endpoint_unsafe.go @@ -12,6 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. +//go:build linux // +build linux package fdbased diff --git a/pkg/tcpip/link/fdbased/mmap.go b/pkg/tcpip/link/fdbased/mmap.go index 5d698a5e9..bfae34ab9 100644 --- a/pkg/tcpip/link/fdbased/mmap.go +++ b/pkg/tcpip/link/fdbased/mmap.go @@ -12,6 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. +//go:build (linux && amd64) || (linux && arm64) // +build linux,amd64 linux,arm64 package fdbased diff --git a/pkg/tcpip/link/fdbased/mmap_stub.go b/pkg/tcpip/link/fdbased/mmap_stub.go index 67be52d67..9d8679502 100644 --- a/pkg/tcpip/link/fdbased/mmap_stub.go +++ b/pkg/tcpip/link/fdbased/mmap_stub.go @@ -12,6 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. +//go:build !linux || (!amd64 && !arm64) // +build !linux !amd64,!arm64 package fdbased diff --git a/pkg/tcpip/link/fdbased/mmap_unsafe.go b/pkg/tcpip/link/fdbased/mmap_unsafe.go index 1293f68a2..58d5dfeef 100644 --- a/pkg/tcpip/link/fdbased/mmap_unsafe.go +++ b/pkg/tcpip/link/fdbased/mmap_unsafe.go @@ -12,6 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. +//go:build (linux && amd64) || (linux && arm64) // +build linux,amd64 linux,arm64 package fdbased diff --git a/pkg/tcpip/link/fdbased/packet_dispatchers.go b/pkg/tcpip/link/fdbased/packet_dispatchers.go index 4b7ef3aac..ab2855a63 100644 --- a/pkg/tcpip/link/fdbased/packet_dispatchers.go +++ b/pkg/tcpip/link/fdbased/packet_dispatchers.go @@ -12,6 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. +//go:build linux // +build linux package fdbased diff --git a/pkg/tcpip/link/rawfile/blockingpoll_noyield_unsafe.go b/pkg/tcpip/link/rawfile/blockingpoll_noyield_unsafe.go index 2206fe0e6..c1438da21 100644 --- a/pkg/tcpip/link/rawfile/blockingpoll_noyield_unsafe.go +++ b/pkg/tcpip/link/rawfile/blockingpoll_noyield_unsafe.go @@ -12,6 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. +//go:build linux && !amd64 && !arm64 // +build linux,!amd64,!arm64 package rawfile diff --git a/pkg/tcpip/link/rawfile/blockingpoll_yield_unsafe.go b/pkg/tcpip/link/rawfile/blockingpoll_yield_unsafe.go index 5002245a1..da900c24b 100644 --- a/pkg/tcpip/link/rawfile/blockingpoll_yield_unsafe.go +++ b/pkg/tcpip/link/rawfile/blockingpoll_yield_unsafe.go @@ -12,6 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. +//go:build ((linux && amd64) || (linux && arm64)) && go1.12 && !go1.18 // +build linux,amd64 linux,arm64 // +build go1.12 // +build !go1.18 diff --git a/pkg/tcpip/link/rawfile/errors.go b/pkg/tcpip/link/rawfile/errors.go index 9743e70ea..7e21a78d4 100644 --- a/pkg/tcpip/link/rawfile/errors.go +++ b/pkg/tcpip/link/rawfile/errors.go @@ -12,6 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. +//go:build linux // +build linux package rawfile diff --git a/pkg/tcpip/link/rawfile/errors_test.go b/pkg/tcpip/link/rawfile/errors_test.go index 8f4bd60da..1b88c309b 100644 --- a/pkg/tcpip/link/rawfile/errors_test.go +++ b/pkg/tcpip/link/rawfile/errors_test.go @@ -12,6 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. +//go:build linux // +build linux package rawfile diff --git a/pkg/tcpip/link/rawfile/rawfile_unsafe.go b/pkg/tcpip/link/rawfile/rawfile_unsafe.go index ba92aedbc..53448a641 100644 --- a/pkg/tcpip/link/rawfile/rawfile_unsafe.go +++ b/pkg/tcpip/link/rawfile/rawfile_unsafe.go @@ -12,6 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. +//go:build linux // +build linux // Package rawfile contains utilities for using the netstack with raw host @@ -19,12 +20,66 @@ package rawfile import ( + "reflect" "unsafe" "golang.org/x/sys/unix" "gvisor.dev/gvisor/pkg/tcpip" ) +// SizeofIovec is the size of a unix.Iovec in bytes. +const SizeofIovec = unsafe.Sizeof(unix.Iovec{}) + +// MaxIovs is UIO_MAXIOV, the maximum number of iovecs that may be passed to a +// host system call in a single array. +const MaxIovs = 1024 + +// IovecFromBytes returns a unix.Iovec representing bs. +// +// Preconditions: len(bs) > 0. +func IovecFromBytes(bs []byte) unix.Iovec { + iov := unix.Iovec{ + Base: &bs[0], + } + iov.SetLen(len(bs)) + return iov +} + +func bytesFromIovec(iov unix.Iovec) (bs []byte) { + sh := (*reflect.SliceHeader)(unsafe.Pointer(&bs)) + sh.Data = uintptr(unsafe.Pointer(iov.Base)) + sh.Len = int(iov.Len) + sh.Cap = int(iov.Len) + return +} + +// AppendIovecFromBytes returns append(iovs, IovecFromBytes(bs)). If len(bs) == +// 0, AppendIovecFromBytes returns iovs without modification. If len(iovs) >= +// max, AppendIovecFromBytes replaces the final iovec in iovs with one that +// also includes the contents of bs. Note that this implies that +// AppendIovecFromBytes is only usable when the returned iovec slice is used as +// the source of a write. +func AppendIovecFromBytes(iovs []unix.Iovec, bs []byte, max int) []unix.Iovec { + if len(bs) == 0 { + return iovs + } + if len(iovs) < max { + return append(iovs, IovecFromBytes(bs)) + } + iovs[len(iovs)-1] = IovecFromBytes(append(bytesFromIovec(iovs[len(iovs)-1]), bs...)) + return iovs +} + +// MMsgHdr represents the mmsg_hdr structure required by recvmmsg() on linux. +type MMsgHdr struct { + Msg unix.Msghdr + Len uint32 + _ [4]byte +} + +// SizeofMMsgHdr is the size of a MMsgHdr in bytes. +const SizeofMMsgHdr = unsafe.Sizeof(MMsgHdr{}) + // GetMTU determines the MTU of a network interface device. func GetMTU(name string) (uint32, error) { fd, err := unix.Socket(unix.AF_UNIX, unix.SOCK_DGRAM, 0) @@ -137,13 +192,6 @@ func BlockingReadv(fd int, iovecs []unix.Iovec) (int, tcpip.Error) { } } -// MMsgHdr represents the mmsg_hdr structure required by recvmmsg() on linux. -type MMsgHdr struct { - Msg unix.Msghdr - Len uint32 - _ [4]byte -} - // BlockingRecvMMsg reads from a file descriptor that is set up as non-blocking // and stores the received messages in a slice of MMsgHdr structures. If no data // is available, it will block in a poll() syscall until the file descriptor diff --git a/pkg/tcpip/link/sharedmem/rx.go b/pkg/tcpip/link/sharedmem/rx.go index 8e6f3e5e3..e882a128c 100644 --- a/pkg/tcpip/link/sharedmem/rx.go +++ b/pkg/tcpip/link/sharedmem/rx.go @@ -12,6 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. +//go:build linux // +build linux package sharedmem diff --git a/pkg/tcpip/link/sharedmem/sharedmem.go b/pkg/tcpip/link/sharedmem/sharedmem.go index df9a0b90a..30cf659b8 100644 --- a/pkg/tcpip/link/sharedmem/sharedmem.go +++ b/pkg/tcpip/link/sharedmem/sharedmem.go @@ -12,6 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. +//go:build linux // +build linux // Package sharedmem provides the implemention of data-link layer endpoints diff --git a/pkg/tcpip/link/sharedmem/sharedmem_test.go b/pkg/tcpip/link/sharedmem/sharedmem_test.go index 0f72d4e95..d6d953085 100644 --- a/pkg/tcpip/link/sharedmem/sharedmem_test.go +++ b/pkg/tcpip/link/sharedmem/sharedmem_test.go @@ -12,6 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. +//go:build linux // +build linux package sharedmem diff --git a/pkg/tcpip/link/sniffer/pcap.go b/pkg/tcpip/link/sniffer/pcap.go index c16c19647..3bb864ed2 100644 --- a/pkg/tcpip/link/sniffer/pcap.go +++ b/pkg/tcpip/link/sniffer/pcap.go @@ -39,8 +39,6 @@ type pcapHeader struct { Network uint32 } -const pcapPacketHeaderLen = 16 - type pcapPacketHeader struct { // Seconds is the timestamp seconds. Seconds uint32 @@ -55,8 +53,7 @@ type pcapPacketHeader struct { OriginalLength uint32 } -func newPCAPPacketHeader(incLen, orgLen uint32) pcapPacketHeader { - now := time.Now() +func newPCAPPacketHeader(now time.Time, incLen, orgLen uint32) pcapPacketHeader { return pcapPacketHeader{ Seconds: uint32(now.Unix()), Microseconds: uint32(now.Nanosecond() / 1000), diff --git a/pkg/tcpip/link/sniffer/sniffer.go b/pkg/tcpip/link/sniffer/sniffer.go index 2d6a3a833..3df826f3c 100644 --- a/pkg/tcpip/link/sniffer/sniffer.go +++ b/pkg/tcpip/link/sniffer/sniffer.go @@ -87,11 +87,7 @@ func NewWithPrefix(lower stack.LinkEndpoint, logPrefix string) stack.LinkEndpoin } func zoneOffset() (int32, error) { - loc, err := time.LoadLocation("Local") - if err != nil { - return 0, err - } - date := time.Date(0, 0, 0, 0, 0, 0, 0, loc) + date := time.Date(0, 0, 0, 0, 0, 0, 0, time.Local) _, offset := date.Zone() return int32(offset), nil } @@ -117,8 +113,9 @@ func writePCAPHeader(w io.Writer, maxLen uint32) error { // NewWithWriter creates a new sniffer link-layer endpoint. It wraps around // another endpoint and logs packets as they traverse the endpoint. // -// Packets are logged to writer in the pcap format. A sniffer created with this -// function will not emit packets using the standard log package. +// Each packet is written to writer in the pcap format in a single Write call +// without synchronization. A sniffer created with this function will not emit +// packets using the standard log package. // // snapLen is the maximum amount of a packet to be saved. Packets with a length // less than or equal to snapLen will be saved in their entirety. Longer @@ -159,27 +156,29 @@ func (e *endpoint) dumpPacket(dir direction, protocol tcpip.NetworkProtocolNumbe if max := int(e.maxPCAPLen); length > max { length = max } - if err := binary.Write(writer, binary.BigEndian, newPCAPPacketHeader(uint32(length), uint32(totalLength))); err != nil { - panic(err) - } - write := func(b []byte) { - if len(b) > length { - b = b[:length] + packetHeader := newPCAPPacketHeader(time.Now(), uint32(length), uint32(totalLength)) + packet := make([]byte, binary.Size(packetHeader)+length) + { + writer := tcpip.SliceWriter(packet) + if err := binary.Write(&writer, binary.BigEndian, packetHeader); err != nil { + panic(err) } - for len(b) != 0 { + for _, b := range pkt.Views() { + if length == 0 { + break + } + if len(b) > length { + b = b[:length] + } n, err := writer.Write(b) if err != nil { panic(err) } - b = b[n:] length -= n } } - for _, v := range pkt.Views() { - if length == 0 { - break - } - write(v) + if _, err := writer.Write(packet); err != nil { + panic(err) } } } diff --git a/pkg/tcpip/link/tun/BUILD b/pkg/tcpip/link/tun/BUILD index 7656cca6a..4758a99ad 100644 --- a/pkg/tcpip/link/tun/BUILD +++ b/pkg/tcpip/link/tun/BUILD @@ -26,6 +26,7 @@ go_library( deps = [ "//pkg/abi/linux", "//pkg/context", + "//pkg/errors/linuxerr", "//pkg/log", "//pkg/refs", "//pkg/refsvfs2", diff --git a/pkg/tcpip/link/tun/device.go b/pkg/tcpip/link/tun/device.go index 36af2a029..d23210503 100644 --- a/pkg/tcpip/link/tun/device.go +++ b/pkg/tcpip/link/tun/device.go @@ -18,6 +18,7 @@ import ( "fmt" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/errors/linuxerr" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/tcpip" @@ -88,12 +89,12 @@ func (d *Device) SetIff(s *stack.Stack, name string, flags Flags) error { defer d.mu.Unlock() if d.endpoint != nil { - return syserror.EINVAL + return linuxerr.EINVAL } // Input validation. if flags.TAP && flags.TUN || !flags.TAP && !flags.TUN { - return syserror.EINVAL + return linuxerr.EINVAL } prefix := "tun" @@ -108,7 +109,7 @@ func (d *Device) SetIff(s *stack.Stack, name string, flags Flags) error { endpoint, err := attachOrCreateNIC(s, name, prefix, linkCaps) if err != nil { - return syserror.EINVAL + return linuxerr.EINVAL } d.endpoint = endpoint @@ -125,7 +126,7 @@ func attachOrCreateNIC(s *stack.Stack, name, prefix string, linkCaps stack.LinkE endpoint, ok := linkEP.(*tunEndpoint) if !ok { // Not a NIC created by tun device. - return nil, syserror.EOPNOTSUPP + return nil, linuxerr.EOPNOTSUPP } if !endpoint.TryIncRef() { // Race detected: NIC got deleted in between. @@ -159,7 +160,7 @@ func attachOrCreateNIC(s *stack.Stack, name, prefix string, linkCaps stack.LinkE // Race detected: A NIC has been created in between. continue default: - return nil, syserror.EINVAL + return nil, linuxerr.EINVAL } } } @@ -170,7 +171,7 @@ func (d *Device) Write(data []byte) (int64, error) { endpoint := d.endpoint d.mu.RUnlock() if endpoint == nil { - return 0, syserror.EBADFD + return 0, linuxerr.EBADFD } if !endpoint.IsAttached() { return 0, syserror.EIO @@ -207,6 +208,15 @@ func (d *Device) Write(data []byte) (int64, error) { protocol = pktInfoHdr.Protocol() case ethHdr != nil: protocol = ethHdr.Type() + case d.flags.TUN: + // TUN interface with IFF_NO_PI enabled, thus + // we need to determine protocol from version field + version := data[0] >> 4 + if version == 4 { + protocol = header.IPv4ProtocolNumber + } else if version == 6 { + protocol = header.IPv6ProtocolNumber + } } // Try to determine remote link address, default zero. @@ -233,7 +243,7 @@ func (d *Device) Read() ([]byte, error) { endpoint := d.endpoint d.mu.RUnlock() if endpoint == nil { - return nil, syserror.EBADFD + return nil, linuxerr.EBADFD } for { @@ -264,13 +274,6 @@ func (d *Device) encodePkt(info *channel.PacketInfo) (buffer.View, bool) { vv.AppendView(buffer.View(hdr)) } - // If the packet does not already have link layer header, and the route - // does not exist, we can't compute it. This is possibly a raw packet, tun - // device doesn't support this at the moment. - if info.Pkt.LinkHeader().View().IsEmpty() && len(info.Route.RemoteLinkAddress) == 0 { - return nil, false - } - // Ethernet header (TAP only). if d.flags.TAP { // Add ethernet header if not provided. diff --git a/pkg/tcpip/link/tun/tun_unsafe.go b/pkg/tcpip/link/tun/tun_unsafe.go index 0591fbd63..db4338e79 100644 --- a/pkg/tcpip/link/tun/tun_unsafe.go +++ b/pkg/tcpip/link/tun/tun_unsafe.go @@ -12,6 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. +//go:build linux // +build linux // Package tun contains methods to open TAP and TUN devices. |