summaryrefslogtreecommitdiffhomepage
path: root/pkg/tcpip/link/fdbased
diff options
context:
space:
mode:
Diffstat (limited to 'pkg/tcpip/link/fdbased')
-rw-r--r--pkg/tcpip/link/fdbased/endpoint.go168
1 files changed, 122 insertions, 46 deletions
diff --git a/pkg/tcpip/link/fdbased/endpoint.go b/pkg/tcpip/link/fdbased/endpoint.go
index 1f889c2a0..b88e2e7bf 100644
--- a/pkg/tcpip/link/fdbased/endpoint.go
+++ b/pkg/tcpip/link/fdbased/endpoint.go
@@ -21,12 +21,29 @@
// FD based endpoints can be used in the networking stack by calling New() to
// create a new endpoint, and then passing it as an argument to
// Stack.CreateNIC().
+//
+// FD based endpoints can use more than one file descriptor to read incoming
+// packets. If there are more than one FDs specified and the underlying FD is an
+// AF_PACKET then the endpoint will enable FANOUT mode on the socket so that the
+// host kernel will consistently hash the packets to the sockets. This ensures
+// that packets for the same TCP streams are not reordered.
+//
+// Similarly if more than one FD's are specified where the underlying FD is not
+// AF_PACKET then it's the caller's responsibility to ensure that all inbound
+// packets on the descriptors are consistently 5 tuple hashed to one of the
+// descriptors to prevent TCP reordering.
+//
+// Since netstack today does not compute 5 tuple hashes for outgoing packets we
+// only use the first FD to write outbound packets. Once 5 tuple hashes for
+// all outbound packets are available we will make use of all underlying FD's to
+// write outbound packets.
package fdbased
import (
"fmt"
"syscall"
+ "golang.org/x/sys/unix"
"gvisor.googlesource.com/gvisor/pkg/tcpip"
"gvisor.googlesource.com/gvisor/pkg/tcpip/buffer"
"gvisor.googlesource.com/gvisor/pkg/tcpip/header"
@@ -65,8 +82,10 @@ const (
)
type endpoint struct {
- // fd is the file descriptor used to send and receive packets.
- fd int
+ // fds is the set of file descriptors each identifying one inbound/outbound
+ // channel. The endpoint will dispatch from all inbound channels as well as
+ // hash outbound packets to specific channels based on the packet hash.
+ fds []int
// mtu (maximum transmission unit) is the maximum size of a packet.
mtu uint32
@@ -85,8 +104,8 @@ type endpoint struct {
// its end of the communication pipe.
closed func(*tcpip.Error)
- inboundDispatcher linkDispatcher
- dispatcher stack.NetworkDispatcher
+ inboundDispatchers []linkDispatcher
+ dispatcher stack.NetworkDispatcher
// packetDispatchMode controls the packet dispatcher used by this
// endpoint.
@@ -99,17 +118,47 @@ type endpoint struct {
// Options specify the details about the fd-based endpoint to be created.
type Options struct {
- FD int
- MTU uint32
- EthernetHeader bool
- ClosedFunc func(*tcpip.Error)
- Address tcpip.LinkAddress
- SaveRestore bool
- DisconnectOk bool
- GSOMaxSize uint32
+ // FDs is a set of FDs used to read/write packets.
+ FDs []int
+
+ // MTU is the mtu to use for this endpoint.
+ MTU uint32
+
+ // EthernetHeader if true, indicates that the endpoint should read/write
+ // ethernet frames instead of IP packets.
+ EthernetHeader bool
+
+ // ClosedFunc is a function to be called when an endpoint's peer (if
+ // any) closes its end of the communication pipe.
+ ClosedFunc func(*tcpip.Error)
+
+ // Address is the link address for this endpoint. Only used if
+ // EthernetHeader is true.
+ Address tcpip.LinkAddress
+
+ // SaveRestore if true, indicates that this NIC capability set should
+ // include CapabilitySaveRestore
+ SaveRestore bool
+
+ // DisconnectOk if true, indicates that this NIC capability set should
+ // include CapabilityDisconnectOk.
+ DisconnectOk bool
+
+ // GSOMaxSize is the maximum GSO packet size. It is zero if GSO is
+ // disabled.
+ GSOMaxSize uint32
+
+ // PacketDispatchMode specifies the type of inbound dispatcher to be
+ // used for this endpoint.
PacketDispatchMode PacketDispatchMode
- TXChecksumOffload bool
- RXChecksumOffload bool
+
+ // TXChecksumOffload if true, indicates that this endpoints capability
+ // set should include CapabilityTXChecksumOffload.
+ TXChecksumOffload bool
+
+ // RXChecksumOffload if true, indicates that this endpoints capability
+ // set should include CapabilityRXChecksumOffload.
+ RXChecksumOffload bool
}
// New creates a new fd-based endpoint.
@@ -117,10 +166,6 @@ type Options struct {
// Makes fd non-blocking, but does not take ownership of fd, which must remain
// open for the lifetime of the returned endpoint.
func New(opts *Options) (tcpip.LinkEndpointID, error) {
- if err := syscall.SetNonblock(opts.FD, true); err != nil {
- return 0, fmt.Errorf("syscall.SetNonblock(%v) failed: %v", opts.FD, err)
- }
-
caps := stack.LinkEndpointCapabilities(0)
if opts.RXChecksumOffload {
caps |= stack.CapabilityRXChecksumOffload
@@ -144,8 +189,12 @@ func New(opts *Options) (tcpip.LinkEndpointID, error) {
caps |= stack.CapabilityDisconnectOk
}
+ if len(opts.FDs) == 0 {
+ return 0, fmt.Errorf("opts.FD is empty, at least one FD must be specified")
+ }
+
e := &endpoint{
- fd: opts.FD,
+ fds: opts.FDs,
mtu: opts.MTU,
caps: caps,
closed: opts.ClosedFunc,
@@ -154,46 +203,71 @@ func New(opts *Options) (tcpip.LinkEndpointID, error) {
packetDispatchMode: opts.PacketDispatchMode,
}
- isSocket, err := isSocketFD(e.fd)
- if err != nil {
- return 0, err
- }
- if isSocket {
- if opts.GSOMaxSize != 0 {
- e.caps |= stack.CapabilityGSO
- e.gsoMaxSize = opts.GSOMaxSize
+ // Create per channel dispatchers.
+ for i := 0; i < len(e.fds); i++ {
+ fd := e.fds[i]
+ if err := syscall.SetNonblock(fd, true); err != nil {
+ return 0, fmt.Errorf("syscall.SetNonblock(%v) failed: %v", fd, err)
}
- }
- e.inboundDispatcher, err = createInboundDispatcher(e, isSocket)
- if err != nil {
- return 0, fmt.Errorf("createInboundDispatcher(...) = %v", err)
+
+ isSocket, err := isSocketFD(fd)
+ if err != nil {
+ return 0, err
+ }
+ if isSocket {
+ if opts.GSOMaxSize != 0 {
+ e.caps |= stack.CapabilityGSO
+ e.gsoMaxSize = opts.GSOMaxSize
+ }
+ }
+ inboundDispatcher, err := createInboundDispatcher(e, fd, isSocket)
+ if err != nil {
+ return 0, fmt.Errorf("createInboundDispatcher(...) = %v", err)
+ }
+ e.inboundDispatchers = append(e.inboundDispatchers, inboundDispatcher)
}
return stack.RegisterLinkEndpoint(e), nil
}
-func createInboundDispatcher(e *endpoint, isSocket bool) (linkDispatcher, error) {
+func createInboundDispatcher(e *endpoint, fd int, isSocket bool) (linkDispatcher, error) {
// By default use the readv() dispatcher as it works with all kinds of
// FDs (tap/tun/unix domain sockets and af_packet).
- inboundDispatcher, err := newReadVDispatcher(e.fd, e)
+ inboundDispatcher, err := newReadVDispatcher(fd, e)
if err != nil {
- return nil, fmt.Errorf("newReadVDispatcher(%d, %+v) = %v", e.fd, e, err)
+ return nil, fmt.Errorf("newReadVDispatcher(%d, %+v) = %v", fd, e, err)
}
if isSocket {
+ sa, err := unix.Getsockname(fd)
+ if err != nil {
+ return nil, fmt.Errorf("unix.Getsockname(%d) = %v", fd, err)
+ }
+ switch sa.(type) {
+ case *unix.SockaddrLinklayer:
+ // enable PACKET_FANOUT mode is the underlying socket is
+ // of type AF_PACKET.
+ const fanoutID = 1
+ const fanoutType = 0x8000 // PACKET_FANOUT_HASH | PACKET_FANOUT_FLAG_DEFRAG
+ fanoutArg := fanoutID | fanoutType<<16
+ if err := syscall.SetsockoptInt(fd, syscall.SOL_PACKET, unix.PACKET_FANOUT, fanoutArg); err != nil {
+ return nil, fmt.Errorf("failed to enable PACKET_FANOUT option: %v", err)
+ }
+ }
+
switch e.packetDispatchMode {
case PacketMMap:
- inboundDispatcher, err = newPacketMMapDispatcher(e.fd, e)
+ inboundDispatcher, err = newPacketMMapDispatcher(fd, e)
if err != nil {
- return nil, fmt.Errorf("newPacketMMapDispatcher(%d, %+v) = %v", e.fd, e, err)
+ return nil, fmt.Errorf("newPacketMMapDispatcher(%d, %+v) = %v", fd, e, err)
}
case RecvMMsg:
// If the provided FD is a socket then we optimize
// packet reads by using recvmmsg() instead of read() to
// read packets in a batch.
- inboundDispatcher, err = newRecvMMsgDispatcher(e.fd, e)
+ inboundDispatcher, err = newRecvMMsgDispatcher(fd, e)
if err != nil {
- return nil, fmt.Errorf("newRecvMMsgDispatcher(%d, %+v) = %v", e.fd, e, err)
+ return nil, fmt.Errorf("newRecvMMsgDispatcher(%d, %+v) = %v", fd, e, err)
}
}
}
@@ -215,7 +289,9 @@ func (e *endpoint) Attach(dispatcher stack.NetworkDispatcher) {
// Link endpoints are not savable. When transportation endpoints are
// saved, they stop sending outgoing packets and all incoming packets
// are rejected.
- go e.dispatchLoop() // S/R-SAFE: See above.
+ for i := range e.inboundDispatchers {
+ go e.dispatchLoop(e.inboundDispatchers[i]) // S/R-SAFE: See above.
+ }
}
// IsAttached implements stack.LinkEndpoint.IsAttached.
@@ -305,26 +381,26 @@ func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, hdr buffer.Prepen
}
}
- return rawfile.NonBlockingWrite3(e.fd, vnetHdrBuf, hdr.View(), payload.ToView())
+ return rawfile.NonBlockingWrite3(e.fds[0], vnetHdrBuf, hdr.View(), payload.ToView())
}
if payload.Size() == 0 {
- return rawfile.NonBlockingWrite(e.fd, hdr.View())
+ return rawfile.NonBlockingWrite(e.fds[0], hdr.View())
}
- return rawfile.NonBlockingWrite3(e.fd, hdr.View(), payload.ToView(), nil)
+ return rawfile.NonBlockingWrite3(e.fds[0], hdr.View(), payload.ToView(), nil)
}
// WriteRawPacket writes a raw packet directly to the file descriptor.
func (e *endpoint) WriteRawPacket(dest tcpip.Address, packet []byte) *tcpip.Error {
- return rawfile.NonBlockingWrite(e.fd, packet)
+ return rawfile.NonBlockingWrite(e.fds[0], packet)
}
// dispatchLoop reads packets from the file descriptor in a loop and dispatches
// them to the network stack.
-func (e *endpoint) dispatchLoop() *tcpip.Error {
+func (e *endpoint) dispatchLoop(inboundDispatcher linkDispatcher) *tcpip.Error {
for {
- cont, err := e.inboundDispatcher.dispatch()
+ cont, err := inboundDispatcher.dispatch()
if err != nil || !cont {
if e.closed != nil {
e.closed(err)
@@ -363,7 +439,7 @@ func NewInjectable(fd int, mtu uint32, capabilities stack.LinkEndpointCapabiliti
syscall.SetNonblock(fd, true)
e := &InjectableEndpoint{endpoint: endpoint{
- fd: fd,
+ fds: []int{fd},
mtu: mtu,
caps: capabilities,
}}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-09 01:22:16 +0000