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Diffstat (limited to 'pkg/tcpip/stack/nic.go')
-rw-r--r--pkg/tcpip/stack/nic.go257
1 files changed, 171 insertions, 86 deletions
diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go
index 04b63d783..0e8a23f00 100644
--- a/pkg/tcpip/stack/nic.go
+++ b/pkg/tcpip/stack/nic.go
@@ -36,13 +36,13 @@ type NIC struct {
demux *transportDemuxer
- mu sync.RWMutex
- spoofing bool
- promiscuous bool
- primary map[tcpip.NetworkProtocolNumber]*ilist.List
- endpoints map[NetworkEndpointID]*referencedNetworkEndpoint
- subnets []tcpip.Subnet
- mcastJoins map[NetworkEndpointID]int32
+ mu sync.RWMutex
+ spoofing bool
+ promiscuous bool
+ primary map[tcpip.NetworkProtocolNumber]*ilist.List
+ endpoints map[NetworkEndpointID]*referencedNetworkEndpoint
+ addressRanges []tcpip.Subnet
+ mcastJoins map[NetworkEndpointID]int32
stats NICStats
}
@@ -102,6 +102,25 @@ func newNIC(stack *Stack, id tcpip.NICID, name string, ep LinkEndpoint, loopback
}
}
+// enable enables the NIC. enable will attach the link to its LinkEndpoint and
+// join the IPv6 All-Nodes Multicast address (ff02::1).
+func (n *NIC) enable() *tcpip.Error {
+ n.attachLinkEndpoint()
+
+ // Join the IPv6 All-Nodes Multicast group if the stack is configured to
+ // use IPv6. This is required to ensure that this node properly receives
+ // and responds to the various NDP messages that are destined to the
+ // all-nodes multicast address. An example is the Neighbor Advertisement
+ // when we perform Duplicate Address Detection, or Router Advertisement
+ // when we do Router Discovery. See RFC 4862, section 5.4.2 and RFC 4861
+ // section 4.2 for more information.
+ if _, ok := n.stack.networkProtocols[header.IPv6ProtocolNumber]; ok {
+ return n.joinGroup(header.IPv6ProtocolNumber, header.IPv6AllNodesMulticastAddress)
+ }
+
+ return nil
+}
+
// attachLinkEndpoint attaches the NIC to the endpoint, which will enable it
// to start delivering packets.
func (n *NIC) attachLinkEndpoint() {
@@ -129,37 +148,6 @@ func (n *NIC) setSpoofing(enable bool) {
n.mu.Unlock()
}
-func (n *NIC) getMainNICAddress(protocol tcpip.NetworkProtocolNumber) (tcpip.AddressWithPrefix, *tcpip.Error) {
- n.mu.RLock()
- defer n.mu.RUnlock()
-
- var r *referencedNetworkEndpoint
-
- // Check for a primary endpoint.
- if list, ok := n.primary[protocol]; ok {
- for e := list.Front(); e != nil; e = e.Next() {
- ref := e.(*referencedNetworkEndpoint)
- if ref.kind == permanent && ref.tryIncRef() {
- r = ref
- break
- }
- }
-
- }
-
- if r == nil {
- return tcpip.AddressWithPrefix{}, tcpip.ErrNoLinkAddress
- }
-
- addressWithPrefix := tcpip.AddressWithPrefix{
- Address: r.ep.ID().LocalAddress,
- PrefixLen: r.ep.PrefixLen(),
- }
- r.decRef()
-
- return addressWithPrefix, nil
-}
-
// primaryEndpoint returns the primary endpoint of n for the given network
// protocol.
func (n *NIC) primaryEndpoint(protocol tcpip.NetworkProtocolNumber) *referencedNetworkEndpoint {
@@ -205,7 +193,7 @@ func (n *NIC) getRefOrCreateTemp(protocol tcpip.NetworkProtocolNumber, address t
if ref, ok := n.endpoints[id]; ok {
// An endpoint with this id exists, check if it can be used and return it.
- switch ref.kind {
+ switch ref.getKind() {
case permanentExpired:
if !spoofingOrPromiscuous {
n.mu.RUnlock()
@@ -224,7 +212,17 @@ func (n *NIC) getRefOrCreateTemp(protocol tcpip.NetworkProtocolNumber, address t
// the caller or if the address is found in the NIC's subnets.
createTempEP := spoofingOrPromiscuous
if !createTempEP {
- for _, sn := range n.subnets {
+ for _, sn := range n.addressRanges {
+ // Skip the subnet address.
+ if address == sn.ID() {
+ continue
+ }
+ // For now just skip the broadcast address, until we support it.
+ // FIXME(b/137608825): Add support for sending/receiving directed
+ // (subnet) broadcast.
+ if address == sn.Broadcast() {
+ continue
+ }
if sn.Contains(address) {
createTempEP = true
break
@@ -276,14 +274,14 @@ func (n *NIC) getRefOrCreateTemp(protocol tcpip.NetworkProtocolNumber, address t
func (n *NIC) addPermanentAddressLocked(protocolAddress tcpip.ProtocolAddress, peb PrimaryEndpointBehavior) (*referencedNetworkEndpoint, *tcpip.Error) {
id := NetworkEndpointID{protocolAddress.AddressWithPrefix.Address}
if ref, ok := n.endpoints[id]; ok {
- switch ref.kind {
+ switch ref.getKind() {
case permanent:
// The NIC already have a permanent endpoint with that address.
return nil, tcpip.ErrDuplicateAddress
case permanentExpired, temporary:
// Promote the endpoint to become permanent.
if ref.tryIncRef() {
- ref.kind = permanent
+ ref.setKind(permanent)
return ref, nil
}
// tryIncRef failing means the endpoint is scheduled to be removed once
@@ -297,6 +295,8 @@ func (n *NIC) addPermanentAddressLocked(protocolAddress tcpip.ProtocolAddress, p
}
func (n *NIC) addAddressLocked(protocolAddress tcpip.ProtocolAddress, peb PrimaryEndpointBehavior, kind networkEndpointKind) (*referencedNetworkEndpoint, *tcpip.Error) {
+ // TODO(b/141022673): Validate IP address before adding them.
+
// Sanity check.
id := NetworkEndpointID{protocolAddress.AddressWithPrefix.Address}
if _, ok := n.endpoints[id]; ok {
@@ -329,6 +329,15 @@ func (n *NIC) addAddressLocked(protocolAddress tcpip.ProtocolAddress, peb Primar
}
}
+ // If we are adding an IPv6 unicast address, join the solicited-node
+ // multicast address.
+ if protocolAddress.Protocol == header.IPv6ProtocolNumber && header.IsV6UnicastAddress(protocolAddress.AddressWithPrefix.Address) {
+ snmc := header.SolicitedNodeAddr(protocolAddress.AddressWithPrefix.Address)
+ if err := n.joinGroupLocked(protocolAddress.Protocol, snmc); err != nil {
+ return nil, err
+ }
+ }
+
n.endpoints[id] = ref
l, ok := n.primary[protocolAddress.Protocol]
@@ -358,15 +367,17 @@ func (n *NIC) AddAddress(protocolAddress tcpip.ProtocolAddress, peb PrimaryEndpo
return err
}
-// Addresses returns the addresses associated with this NIC.
-func (n *NIC) Addresses() []tcpip.ProtocolAddress {
+// AllAddresses returns all addresses (primary and non-primary) associated with
+// this NIC.
+func (n *NIC) AllAddresses() []tcpip.ProtocolAddress {
n.mu.RLock()
defer n.mu.RUnlock()
+
addrs := make([]tcpip.ProtocolAddress, 0, len(n.endpoints))
for nid, ref := range n.endpoints {
// Don't include expired or tempory endpoints to avoid confusion and
// prevent the caller from using those.
- switch ref.kind {
+ switch ref.getKind() {
case permanentExpired, temporary:
continue
}
@@ -381,45 +392,66 @@ func (n *NIC) Addresses() []tcpip.ProtocolAddress {
return addrs
}
-// AddSubnet adds a new subnet to n, so that it starts accepting packets
-// targeted at the given address and network protocol.
-func (n *NIC) AddSubnet(protocol tcpip.NetworkProtocolNumber, subnet tcpip.Subnet) {
+// PrimaryAddresses returns the primary addresses associated with this NIC.
+func (n *NIC) PrimaryAddresses() []tcpip.ProtocolAddress {
+ n.mu.RLock()
+ defer n.mu.RUnlock()
+
+ var addrs []tcpip.ProtocolAddress
+ for proto, list := range n.primary {
+ for e := list.Front(); e != nil; e = e.Next() {
+ ref := e.(*referencedNetworkEndpoint)
+ // Don't include expired or tempory endpoints to avoid confusion and
+ // prevent the caller from using those.
+ switch ref.getKind() {
+ case permanentExpired, temporary:
+ continue
+ }
+
+ addrs = append(addrs, tcpip.ProtocolAddress{
+ Protocol: proto,
+ AddressWithPrefix: tcpip.AddressWithPrefix{
+ Address: ref.ep.ID().LocalAddress,
+ PrefixLen: ref.ep.PrefixLen(),
+ },
+ })
+ }
+ }
+ return addrs
+}
+
+// AddAddressRange adds a range of addresses to n, so that it starts accepting
+// packets targeted at the given addresses and network protocol. The range is
+// given by a subnet address, and all addresses contained in the subnet are
+// used except for the subnet address itself and the subnet's broadcast
+// address.
+func (n *NIC) AddAddressRange(protocol tcpip.NetworkProtocolNumber, subnet tcpip.Subnet) {
n.mu.Lock()
- n.subnets = append(n.subnets, subnet)
+ n.addressRanges = append(n.addressRanges, subnet)
n.mu.Unlock()
}
-// RemoveSubnet removes the given subnet from n.
-func (n *NIC) RemoveSubnet(subnet tcpip.Subnet) {
+// RemoveAddressRange removes the given address range from n.
+func (n *NIC) RemoveAddressRange(subnet tcpip.Subnet) {
n.mu.Lock()
// Use the same underlying array.
- tmp := n.subnets[:0]
- for _, sub := range n.subnets {
+ tmp := n.addressRanges[:0]
+ for _, sub := range n.addressRanges {
if sub != subnet {
tmp = append(tmp, sub)
}
}
- n.subnets = tmp
+ n.addressRanges = tmp
n.mu.Unlock()
}
-// ContainsSubnet reports whether this NIC contains the given subnet.
-func (n *NIC) ContainsSubnet(subnet tcpip.Subnet) bool {
- for _, s := range n.Subnets() {
- if s == subnet {
- return true
- }
- }
- return false
-}
-
// Subnets returns the Subnets associated with this NIC.
-func (n *NIC) Subnets() []tcpip.Subnet {
+func (n *NIC) AddressRanges() []tcpip.Subnet {
n.mu.RLock()
defer n.mu.RUnlock()
- sns := make([]tcpip.Subnet, 0, len(n.subnets)+len(n.endpoints))
+ sns := make([]tcpip.Subnet, 0, len(n.addressRanges)+len(n.endpoints))
for nid := range n.endpoints {
sn, err := tcpip.NewSubnet(nid.LocalAddress, tcpip.AddressMask(strings.Repeat("\xff", len(nid.LocalAddress))))
if err != nil {
@@ -429,7 +461,7 @@ func (n *NIC) Subnets() []tcpip.Subnet {
}
sns = append(sns, sn)
}
- return append(sns, n.subnets...)
+ return append(sns, n.addressRanges...)
}
func (n *NIC) removeEndpointLocked(r *referencedNetworkEndpoint) {
@@ -444,7 +476,7 @@ func (n *NIC) removeEndpointLocked(r *referencedNetworkEndpoint) {
return
}
- if r.kind == permanent {
+ if r.getKind() == permanent {
panic("Reference count dropped to zero before being removed")
}
@@ -464,13 +496,27 @@ func (n *NIC) removeEndpoint(r *referencedNetworkEndpoint) {
}
func (n *NIC) removePermanentAddressLocked(addr tcpip.Address) *tcpip.Error {
- r := n.endpoints[NetworkEndpointID{addr}]
- if r == nil || r.kind != permanent {
+ r, ok := n.endpoints[NetworkEndpointID{addr}]
+ if !ok || r.getKind() != permanent {
return tcpip.ErrBadLocalAddress
}
- r.kind = permanentExpired
- r.decRefLocked()
+ r.setKind(permanentExpired)
+ if !r.decRefLocked() {
+ // The endpoint still has references to it.
+ return nil
+ }
+
+ // At this point the endpoint is deleted.
+
+ // If we are removing an IPv6 unicast address, leave the solicited-node
+ // multicast address.
+ if r.protocol == header.IPv6ProtocolNumber && header.IsV6UnicastAddress(addr) {
+ snmc := header.SolicitedNodeAddr(addr)
+ if err := n.leaveGroupLocked(snmc); err != nil {
+ return err
+ }
+ }
return nil
}
@@ -488,6 +534,13 @@ func (n *NIC) joinGroup(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address
n.mu.Lock()
defer n.mu.Unlock()
+ return n.joinGroupLocked(protocol, addr)
+}
+
+// joinGroupLocked adds a new endpoint for the given multicast address, if none
+// exists yet. Otherwise it just increments its count. n MUST be locked before
+// joinGroupLocked is called.
+func (n *NIC) joinGroupLocked(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address) *tcpip.Error {
id := NetworkEndpointID{addr}
joins := n.mcastJoins[id]
if joins == 0 {
@@ -515,6 +568,13 @@ func (n *NIC) leaveGroup(addr tcpip.Address) *tcpip.Error {
n.mu.Lock()
defer n.mu.Unlock()
+ return n.leaveGroupLocked(addr)
+}
+
+// leaveGroupLocked decrements the count for the given multicast address, and
+// when it reaches zero removes the endpoint for this address. n MUST be locked
+// before leaveGroupLocked is called.
+func (n *NIC) leaveGroupLocked(addr tcpip.Address) *tcpip.Error {
id := NetworkEndpointID{addr}
joins := n.mcastJoins[id]
switch joins {
@@ -531,6 +591,13 @@ func (n *NIC) leaveGroup(addr tcpip.Address) *tcpip.Error {
return nil
}
+func handlePacket(protocol tcpip.NetworkProtocolNumber, dst, src tcpip.Address, localLinkAddr, remotelinkAddr tcpip.LinkAddress, ref *referencedNetworkEndpoint, vv buffer.VectorisedView) {
+ r := makeRoute(protocol, dst, src, localLinkAddr, ref, false /* handleLocal */, false /* multicastLoop */)
+ r.RemoteLinkAddress = remotelinkAddr
+ ref.ep.HandlePacket(&r, vv)
+ ref.decRef()
+}
+
// DeliverNetworkPacket finds the appropriate network protocol endpoint and
// hands the packet over for further processing. This function is called when
// the NIC receives a packet from the physical interface.
@@ -558,6 +625,8 @@ func (n *NIC) DeliverNetworkPacket(linkEP LinkEndpoint, remote, _ tcpip.LinkAddr
src, dst := netProto.ParseAddresses(vv.First())
+ n.stack.AddLinkAddress(n.id, src, remote)
+
// If the packet is destined to the IPv4 Broadcast address, then make a
// route to each IPv4 network endpoint and let each endpoint handle the
// packet.
@@ -566,10 +635,7 @@ func (n *NIC) DeliverNetworkPacket(linkEP LinkEndpoint, remote, _ tcpip.LinkAddr
n.mu.RLock()
for _, ref := range n.endpoints {
if ref.isValidForIncoming() && ref.protocol == header.IPv4ProtocolNumber && ref.tryIncRef() {
- r := makeRoute(protocol, dst, src, linkEP.LinkAddress(), ref, false /* handleLocal */, false /* multicastLoop */)
- r.RemoteLinkAddress = remote
- ref.ep.HandlePacket(&r, vv)
- ref.decRef()
+ handlePacket(protocol, dst, src, linkEP.LinkAddress(), remote, ref, vv)
}
}
n.mu.RUnlock()
@@ -577,10 +643,7 @@ func (n *NIC) DeliverNetworkPacket(linkEP LinkEndpoint, remote, _ tcpip.LinkAddr
}
if ref := n.getRef(protocol, dst); ref != nil {
- r := makeRoute(protocol, dst, src, linkEP.LinkAddress(), ref, false /* handleLocal */, false /* multicastLoop */)
- r.RemoteLinkAddress = remote
- ref.ep.HandlePacket(&r, vv)
- ref.decRef()
+ handlePacket(protocol, dst, src, linkEP.LinkAddress(), remote, ref, vv)
return
}
@@ -676,7 +739,7 @@ func (n *NIC) DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolN
// We could not find an appropriate destination for this packet, so
// deliver it to the global handler.
- if !transProto.HandleUnknownDestinationPacket(r, id, vv) {
+ if !transProto.HandleUnknownDestinationPacket(r, id, netHeader, vv) {
n.stack.stats.MalformedRcvdPackets.Increment()
}
}
@@ -717,7 +780,12 @@ func (n *NIC) ID() tcpip.NICID {
return n.id
}
-type networkEndpointKind int
+// Stack returns the instance of the Stack that owns this NIC.
+func (n *NIC) Stack() *Stack {
+ return n.stack
+}
+
+type networkEndpointKind int32
const (
// A permanent endpoint is created by adding a permanent address (vs. a
@@ -756,21 +824,30 @@ type referencedNetworkEndpoint struct {
// triggers the automatic removal of the endpoint from the NIC.
refs int32
+ // networkEndpointKind must only be accessed using {get,set}Kind().
kind networkEndpointKind
}
+func (r *referencedNetworkEndpoint) getKind() networkEndpointKind {
+ return networkEndpointKind(atomic.LoadInt32((*int32)(&r.kind)))
+}
+
+func (r *referencedNetworkEndpoint) setKind(kind networkEndpointKind) {
+ atomic.StoreInt32((*int32)(&r.kind), int32(kind))
+}
+
// isValidForOutgoing returns true if the endpoint can be used to send out a
// packet. It requires the endpoint to not be marked expired (i.e., its address
// has been removed), or the NIC to be in spoofing mode.
func (r *referencedNetworkEndpoint) isValidForOutgoing() bool {
- return r.kind != permanentExpired || r.nic.spoofing
+ return r.getKind() != permanentExpired || r.nic.spoofing
}
// isValidForIncoming returns true if the endpoint can accept an incoming
// packet. It requires the endpoint to not be marked expired (i.e., its address
// has been removed), or the NIC to be in promiscuous mode.
func (r *referencedNetworkEndpoint) isValidForIncoming() bool {
- return r.kind != permanentExpired || r.nic.promiscuous
+ return r.getKind() != permanentExpired || r.nic.promiscuous
}
// decRef decrements the ref count and cleans up the endpoint once it reaches
@@ -782,11 +859,14 @@ func (r *referencedNetworkEndpoint) decRef() {
}
// decRefLocked is the same as decRef but assumes that the NIC.mu mutex is
-// locked.
-func (r *referencedNetworkEndpoint) decRefLocked() {
+// locked. Returns true if the endpoint was removed.
+func (r *referencedNetworkEndpoint) decRefLocked() bool {
if atomic.AddInt32(&r.refs, -1) == 0 {
r.nic.removeEndpointLocked(r)
+ return true
}
+
+ return false
}
// incRef increments the ref count. It must only be called when the caller is
@@ -811,3 +891,8 @@ func (r *referencedNetworkEndpoint) tryIncRef() bool {
}
}
}
+
+// stack returns the Stack instance that owns the underlying endpoint.
+func (r *referencedNetworkEndpoint) stack() *Stack {
+ return r.nic.stack
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-19 03:29:47 +0000