diff options
| -rw-r--r-- | pkg/tcpip/link/fdbased/endpoint.go | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/pkg/tcpip/link/fdbased/endpoint.go b/pkg/tcpip/link/fdbased/endpoint.go index bddb1d0a2..735c28da1 100644 --- a/pkg/tcpip/link/fdbased/endpoint.go +++ b/pkg/tcpip/link/fdbased/endpoint.go @@ -41,7 +41,6 @@ package fdbased import ( "fmt" - "math" "sync/atomic" "golang.org/x/sys/unix" @@ -196,8 +195,12 @@ type Options struct { // option for an FD with a fanoutID already in use by another FD for a different // NIC will return an EINVAL. // +// Since fanoutID must be unique within the network namespace, we start with +// the PID to avoid collisions. The only way to be sure of avoiding collisions +// is to run in a new network namespace. +// // Must be accessed using atomic operations. -var fanoutID int32 = 0 +var fanoutID int32 = int32(unix.Getpid()) // New creates a new fd-based endpoint. // @@ -292,11 +295,6 @@ func createInboundDispatcher(e *endpoint, fd int, isSocket bool, fID int32) (lin } switch sa.(type) { case *unix.SockaddrLinklayer: - // See: PACKET_FANOUT_MAX in net/packet/internal.h - const packetFanoutMax = 1 << 16 - if fID > packetFanoutMax { - return nil, fmt.Errorf("host fanoutID limit exceeded, fanoutID must be <= %d", math.MaxUint16) - } // Enable PACKET_FANOUT mode if the underlying socket is of type // AF_PACKET. We do not enable PACKET_FANOUT_FLAG_DEFRAG as that will // prevent gvisor from receiving fragmented packets and the host does the @@ -317,7 +315,7 @@ func createInboundDispatcher(e *endpoint, fd int, isSocket bool, fID int32) (lin // // See: https://github.com/torvalds/linux/blob/7acac4b3196caee5e21fb5ea53f8bc124e6a16fc/net/packet/af_packet.c#L3881 const fanoutType = unix.PACKET_FANOUT_HASH - fanoutArg := int(fID) | fanoutType<<16 + fanoutArg := (int(fID) & 0xffff) | fanoutType<<16 if err := unix.SetsockoptInt(fd, unix.SOL_PACKET, unix.PACKET_FANOUT, fanoutArg); err != nil { return nil, fmt.Errorf("failed to enable PACKET_FANOUT option: %v", err) } |