diff options
Diffstat (limited to 'pkg/tcpip/stack/registration.go')
| -rw-r--r-- | pkg/tcpip/stack/registration.go | 261 |
1 files changed, 258 insertions, 3 deletions
diff --git a/pkg/tcpip/stack/registration.go b/pkg/tcpip/stack/registration.go index 780a5ebde..ef42fd6e1 100644 --- a/pkg/tcpip/stack/registration.go +++ b/pkg/tcpip/stack/registration.go @@ -15,6 +15,8 @@ package stack import ( + "fmt" + "gvisor.dev/gvisor/pkg/sleep" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/buffer" @@ -259,9 +261,251 @@ type NetworkHeaderParams struct { TOS uint8 } +// GroupAddressableEndpoint is an endpoint that supports group addressing. +// +// An endpoint is considered to support group addressing when one or more +// endpoints may associate themselves with the same identifier (group address). +type GroupAddressableEndpoint interface { + // JoinGroup joins the spcified group. + // + // Returns true if the group was newly joined. + JoinGroup(group tcpip.Address) (bool, *tcpip.Error) + + // LeaveGroup attempts to leave the specified group. + // + // Returns tcpip.ErrBadLocalAddress if the endpoint has not joined the group. + LeaveGroup(group tcpip.Address) (bool, *tcpip.Error) + + // IsInGroup returns true if the endpoint is a member of the specified group. + IsInGroup(group tcpip.Address) bool +} + +// PrimaryEndpointBehavior is an enumeration of an AddressEndpoint's primary +// behavior. +type PrimaryEndpointBehavior int + +const ( + // CanBePrimaryEndpoint indicates the endpoint can be used as a primary + // endpoint for new connections with no local address. This is the + // default when calling NIC.AddAddress. + CanBePrimaryEndpoint PrimaryEndpointBehavior = iota + + // FirstPrimaryEndpoint indicates the endpoint should be the first + // primary endpoint considered. If there are multiple endpoints with + // this behavior, they are ordered by recency. + FirstPrimaryEndpoint + + // NeverPrimaryEndpoint indicates the endpoint should never be a + // primary endpoint. + NeverPrimaryEndpoint +) + +// AddressConfigType is the method used to add an address. +type AddressConfigType int + +const ( + // AddressConfigStatic is a statically configured address endpoint that was + // added by some user-specified action (adding an explicit address, joining a + // multicast group). + AddressConfigStatic AddressConfigType = iota + + // AddressConfigSlaac is an address endpoint added by SLAAC, as per RFC 4862 + // section 5.5.3. + AddressConfigSlaac + + // AddressConfigSlaacTemp is a temporary address endpoint added by SLAAC as + // per RFC 4941. Temporary SLAAC addresses are short-lived and are not + // to be valid (or preferred) forever; hence the term temporary. + AddressConfigSlaacTemp +) + +// AssignableAddressEndpoint is a reference counted address endpoint that may be +// assigned to a NetworkEndpoint. +type AssignableAddressEndpoint interface { + // NetworkEndpoint returns the NetworkEndpoint the receiver is associated + // with. + NetworkEndpoint() NetworkEndpoint + + // AddressWithPrefix returns the endpoint's address. + AddressWithPrefix() tcpip.AddressWithPrefix + + // IsAssigned returns whether or not the endpoint is considered bound + // to its NetworkEndpoint. + IsAssigned(allowExpired bool) bool + + // IncRef increments this endpoint's reference count. + // + // Returns true if it was successfully incremented. If it returns false, then + // the endpoint is considered expired and should no longer be used. + IncRef() bool + + // DecRef decrements this endpoint's reference count. + DecRef() +} + +// AddressEndpoint is an endpoint representing an address assigned to an +// AddressableEndpoint. +type AddressEndpoint interface { + AssignableAddressEndpoint + + // GetKind returns the address kind for this endpoint. + GetKind() AddressKind + + // SetKind sets the address kind for this endpoint. + SetKind(AddressKind) + + // ConfigType returns the method used to add the address. + ConfigType() AddressConfigType + + // Deprecated returns whether or not this endpoint is deprecated. + Deprecated() bool + + // SetDeprecated sets this endpoint's deprecated status. + SetDeprecated(bool) +} + +// AddressKind is the kind of of an address. +// +// See the values of AddressKind for more details. +type AddressKind int + +const ( + // PermanentTentative is a permanent address endpoint that is not yet + // considered to be fully bound to an interface in the traditional + // sense. That is, the address is associated with a NIC, but packets + // destined to the address MUST NOT be accepted and MUST be silently + // dropped, and the address MUST NOT be used as a source address for + // outgoing packets. For IPv6, addresses are of this kind until NDP's + // Duplicate Address Detection (DAD) resolves. If DAD fails, the address + // is removed. + PermanentTentative AddressKind = iota + + // Permanent is a permanent endpoint (vs. a temporary one) assigned to the + // NIC. Its reference count is biased by 1 to avoid removal when no route + // holds a reference to it. It is removed by explicitly removing the address + // from the NIC. + Permanent + + // PermanentExpired is a permanent endpoint that had its address removed from + // the NIC, and it is waiting to be removed once no references to it are held. + // + // If the address is re-added before the endpoint is removed, its type + // changes back to Permanent. + PermanentExpired + + // Temporary is an endpoint, created on a one-off basis to temporarily + // consider the NIC bound an an address that it is not explictiy bound to + // (such as a permanent address). Its reference count must not be biased by 1 + // so that the address is removed immediately when references to it are no + // longer held. + // + // A temporary endpoint may be promoted to permanent if the address is added + // permanently. + Temporary +) + +// IsPermanent returns true if the AddressKind represents a permanent address. +func (k AddressKind) IsPermanent() bool { + switch k { + case Permanent, PermanentTentative: + return true + case Temporary, PermanentExpired: + return false + default: + panic(fmt.Sprintf("unrecognized address kind = %d", k)) + } +} + +// AddressableEndpoint is an endpoint that supports addressing. +// +// An endpoint is considered to support addressing when the endpoint may +// associate itself with an identifier (address). +type AddressableEndpoint interface { + // AddAndAcquirePermanentAddress adds the passed permanent address. + // + // Returns tcpip.ErrDuplicateAddress if the address exists. + // + // Acquires and returns the AddressEndpoint for the added address. + AddAndAcquirePermanentAddress(addr tcpip.AddressWithPrefix, peb PrimaryEndpointBehavior, configType AddressConfigType, deprecated bool) (AddressEndpoint, *tcpip.Error) + + // RemovePermanentAddress removes the passed address if it is a permanent + // address. + // + // Returns tcpip.ErrBadLocalAddress if the endpoint does not have the passed + // permanent address. + RemovePermanentAddress(addr tcpip.Address) *tcpip.Error + + // AcquireAssignedAddress returns an AddressEndpoint for the passed address + // that is considered bound to the endpoint, optionally creating a temporary + // endpoint if requested and no existing address exists. + // + // The returned endpoint's reference count is incremented. + // + // Returns nil if the specified address is not local to this endpoint. + AcquireAssignedAddress(localAddr tcpip.Address, allowTemp bool, tempPEB PrimaryEndpointBehavior) AddressEndpoint + + // AcquirePrimaryAddress returns a primary endpoint to use when communicating + // with the passed remote address. + // + // If allowExpired is true, expired addresses may be returned. + // + // The returned endpoint's reference count is incremented. + // + // Returns nil if a primary endpoint is not available. + AcquirePrimaryAddress(remoteAddr tcpip.Address, allowExpired bool) AddressEndpoint + + // PrimaryAddresses returns the primary addresses. + PrimaryAddresses() []tcpip.AddressWithPrefix + + // PermanentAddresses returns all the permanent addresses. + PermanentAddresses() []tcpip.AddressWithPrefix +} + +// NDPEndpoint is a network endpoint that supports NDP. +type NDPEndpoint interface { + NetworkEndpoint + + // InvalidateDefaultRouter invalidates a default router discovered through + // NDP. + InvalidateDefaultRouter(tcpip.Address) +} + +// NetworkInterface is a network interface. +type NetworkInterface interface { + // ID returns the interface's ID. + ID() tcpip.NICID + + // IsLoopback returns true if the interface is a loopback interface. + IsLoopback() bool + + // Name returns the name of the interface. + // + // May return an empty string if the interface is not configured with a name. + Name() string + + // Enabled returns true if the interface is enabled. + Enabled() bool +} + // NetworkEndpoint is the interface that needs to be implemented by endpoints // of network layer protocols (e.g., ipv4, ipv6). type NetworkEndpoint interface { + AddressableEndpoint + + // Enable enables the endpoint. + // + // Must only be called when the stack is in a state that allows the endpoint + // to send and receive packets. + // + // Returns tcpip.ErrNotPermitted if the endpoint cannot be enabled. + Enable() *tcpip.Error + + // Enabled returns true if the endpoint is enabled. + Enabled() bool + + // Disable disables the endpoint. + Disable() + // DefaultTTL is the default time-to-live value (or hop limit, in ipv6) // for this endpoint. DefaultTTL() uint8 @@ -312,6 +556,17 @@ type NetworkEndpoint interface { NetworkProtocolNumber() tcpip.NetworkProtocolNumber } +// ForwardingNetworkProtocol is a NetworkProtocol that may forward packets. +type ForwardingNetworkProtocol interface { + NetworkProtocol + + // Forwarding returns the forwarding configuration. + Forwarding() bool + + // SetForwarding sets the forwarding configuration. + SetForwarding(bool) +} + // NetworkProtocol is the interface that needs to be implemented by network // protocols (e.g., ipv4, ipv6) that want to be part of the networking stack. type NetworkProtocol interface { @@ -331,7 +586,7 @@ type NetworkProtocol interface { ParseAddresses(v buffer.View) (src, dst tcpip.Address) // NewEndpoint creates a new endpoint of this protocol. - NewEndpoint(nicID tcpip.NICID, linkAddrCache LinkAddressCache, nud NUDHandler, dispatcher TransportDispatcher, sender LinkEndpoint, st *Stack) NetworkEndpoint + NewEndpoint(nic NetworkInterface, linkAddrCache LinkAddressCache, nud NUDHandler, dispatcher TransportDispatcher, sender LinkEndpoint, st *Stack) NetworkEndpoint // SetOption allows enabling/disabling protocol specific features. // SetOption returns an error if the option is not supported or the @@ -460,8 +715,8 @@ type LinkEndpoint interface { // Attach attaches the data link layer endpoint to the network-layer // dispatcher of the stack. // - // Attach will be called with a nil dispatcher if the receiver's associated - // NIC is being removed. + // Attach is called with a nil dispatcher when the endpoint's NIC is being + // removed. Attach(dispatcher NetworkDispatcher) // IsAttached returns whether a NetworkDispatcher is attached to the |