diff options
Diffstat (limited to 'pkg/tcpip/network/ipv4/ipv4.go')
| -rw-r--r-- | pkg/tcpip/network/ipv4/ipv4.go | 44 |
1 files changed, 16 insertions, 28 deletions
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go index b7a06f525..b7b07a6c1 100644 --- a/pkg/tcpip/network/ipv4/ipv4.go +++ b/pkg/tcpip/network/ipv4/ipv4.go @@ -14,9 +14,9 @@ // Package ipv4 contains the implementation of the ipv4 network protocol. To use // it in the networking stack, this package must be added to the project, and -// activated on the stack by passing ipv4.ProtocolName (or "ipv4") as one of the -// network protocols when calling stack.New(). Then endpoints can be created -// by passing ipv4.ProtocolNumber as the network protocol number when calling +// activated on the stack by passing ipv4.NewProtocol() as one of the network +// protocols when calling stack.New(). Then endpoints can be created by passing +// ipv4.ProtocolNumber as the network protocol number when calling // Stack.NewEndpoint(). package ipv4 @@ -32,9 +32,6 @@ import ( ) const ( - // ProtocolName is the string representation of the ipv4 protocol name. - ProtocolName = "ipv4" - // ProtocolNumber is the ipv4 protocol number. ProtocolNumber = header.IPv4ProtocolNumber @@ -53,6 +50,7 @@ type endpoint struct { linkEP stack.LinkEndpoint dispatcher stack.TransportDispatcher fragmentation *fragmentation.Fragmentation + protocol *protocol } // NewEndpoint creates a new ipv4 endpoint. @@ -64,6 +62,7 @@ func (p *protocol) NewEndpoint(nicid tcpip.NICID, addrWithPrefix tcpip.AddressWi linkEP: linkEP, dispatcher: dispatcher, fragmentation: fragmentation.NewFragmentation(fragmentation.HighFragThreshold, fragmentation.LowFragThreshold, fragmentation.DefaultReassembleTimeout), + protocol: p, } return e, nil @@ -204,7 +203,7 @@ func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, hdr buffer.Prepen if length > header.IPv4MaximumHeaderSize+8 { // Packets of 68 bytes or less are required by RFC 791 to not be // fragmented, so we only assign ids to larger packets. - id = atomic.AddUint32(&ids[hashRoute(r, protocol)%buckets], 1) + id = atomic.AddUint32(&e.protocol.ids[hashRoute(r, protocol, e.protocol.hashIV)%buckets], 1) } ip.Encode(&header.IPv4Fields{ IHL: header.IPv4MinimumSize, @@ -267,7 +266,7 @@ func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, payload buffer.Vect if payload.Size() > header.IPv4MaximumHeaderSize+8 { // Packets of 68 bytes or less are required by RFC 791 to not be // fragmented, so we only assign ids to larger packets. - id = atomic.AddUint32(&ids[hashRoute(r, 0 /* protocol */)%buckets], 1) + id = atomic.AddUint32(&e.protocol.ids[hashRoute(r, 0 /* protocol */, e.protocol.hashIV)%buckets], 1) } ip.SetID(uint16(id)) } @@ -325,14 +324,9 @@ func (e *endpoint) HandlePacket(r *stack.Route, vv buffer.VectorisedView) { // Close cleans up resources associated with the endpoint. func (e *endpoint) Close() {} -type protocol struct{} - -// NewProtocol creates a new protocol ipv4 protocol descriptor. This is exported -// only for tests that short-circuit the stack. Regular use of the protocol is -// done via the stack, which gets a protocol descriptor from the init() function -// below. -func NewProtocol() stack.NetworkProtocol { - return &protocol{} +type protocol struct { + ids []uint32 + hashIV uint32 } // Number returns the ipv4 protocol number. @@ -378,7 +372,7 @@ func calculateMTU(mtu uint32) uint32 { // hashRoute calculates a hash value for the given route. It uses the source & // destination address, the transport protocol number, and a random initial // value (generated once on initialization) to generate the hash. -func hashRoute(r *stack.Route, protocol tcpip.TransportProtocolNumber) uint32 { +func hashRoute(r *stack.Route, protocol tcpip.TransportProtocolNumber, hashIV uint32) uint32 { t := r.LocalAddress a := uint32(t[0]) | uint32(t[1])<<8 | uint32(t[2])<<16 | uint32(t[3])<<24 t = r.RemoteAddress @@ -386,22 +380,16 @@ func hashRoute(r *stack.Route, protocol tcpip.TransportProtocolNumber) uint32 { return hash.Hash3Words(a, b, uint32(protocol), hashIV) } -var ( - ids []uint32 - hashIV uint32 -) - -func init() { - ids = make([]uint32, buckets) +// NewProtocol returns an IPv4 network protocol. +func NewProtocol() stack.NetworkProtocol { + ids := make([]uint32, buckets) // Randomly initialize hashIV and the ids. r := hash.RandN32(1 + buckets) for i := range ids { ids[i] = r[i] } - hashIV = r[buckets] + hashIV := r[buckets] - stack.RegisterNetworkProtocolFactory(ProtocolName, func() stack.NetworkProtocol { - return &protocol{} - }) + return &protocol{ids: ids, hashIV: hashIV} } |