diff options
Diffstat (limited to 'pkg/tcpip/stack/registration.go')
| -rw-r--r-- | pkg/tcpip/stack/registration.go | 93 |
1 files changed, 92 insertions, 1 deletions
diff --git a/pkg/tcpip/stack/registration.go b/pkg/tcpip/stack/registration.go index 2bc1c4270..43e9e4beb 100644 --- a/pkg/tcpip/stack/registration.go +++ b/pkg/tcpip/stack/registration.go @@ -16,6 +16,7 @@ package stack import ( "fmt" + "time" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/buffer" @@ -851,7 +852,97 @@ type InjectableLinkEndpoint interface { InjectOutbound(dest tcpip.Address, packet []byte) tcpip.Error } -// A LinkAddressResolver handles link address resolution for a network protocol. +// DADResult is the result of a duplicate address detection process. +type DADResult struct { + // Resolved is true when DAD completed without detecting a duplicate address + // on the link. + // + // Ignored when Err is non-nil. + Resolved bool + + // Err is an error encountered while performing DAD. + Err tcpip.Error +} + +// DADCompletionHandler is a handler for DAD completion. +type DADCompletionHandler func(DADResult) + +// DADCheckAddressDisposition enumerates the possible return values from +// DAD.CheckDuplicateAddress. +type DADCheckAddressDisposition int + +const ( + _ DADCheckAddressDisposition = iota + + // DADDisabled indicates that DAD is disabled. + DADDisabled + + // DADStarting indicates that DAD is starting for an address. + DADStarting + + // DADAlreadyRunning indicates that DAD was already started for an address. + DADAlreadyRunning +) + +const ( + // defaultDupAddrDetectTransmits is the default number of NDP Neighbor + // Solicitation messages to send when doing Duplicate Address Detection + // for a tentative address. + // + // Default = 1 (from RFC 4862 section 5.1) + defaultDupAddrDetectTransmits = 1 +) + +// DADConfigurations holds configurations for duplicate address detection. +type DADConfigurations struct { + // The number of Neighbor Solicitation messages to send when doing + // Duplicate Address Detection for a tentative address. + // + // Note, a value of zero effectively disables DAD. + DupAddrDetectTransmits uint8 + + // The amount of time to wait between sending Neighbor Solicitation + // messages. + // + // Must be greater than or equal to 1ms. + RetransmitTimer time.Duration +} + +// DefaultDADConfigurations returns the default DAD configurations. +func DefaultDADConfigurations() DADConfigurations { + return DADConfigurations{ + DupAddrDetectTransmits: defaultDupAddrDetectTransmits, + RetransmitTimer: defaultRetransmitTimer, + } +} + +// Validate modifies the configuration with valid values. If invalid values are +// present in the configurations, the corresponding default values are used +// instead. +func (c *DADConfigurations) Validate() { + if c.RetransmitTimer < minimumRetransmitTimer { + c.RetransmitTimer = defaultRetransmitTimer + } +} + +// DuplicateAddressDetector handles checking if an address is already assigned +// to some neighboring node on the link. +type DuplicateAddressDetector interface { + // CheckDuplicateAddress checks if an address is assigned to a neighbor. + // + // If DAD is already being performed for the address, the handler will be + // called with the result of the original DAD request. + CheckDuplicateAddress(tcpip.Address, DADCompletionHandler) DADCheckAddressDisposition + + // SetDADConfiguations sets the configurations for DAD. + SetDADConfigurations(c DADConfigurations) + + // DuplicateAddressProtocol returns the network protocol the receiver can + // perform duplicate address detection for. + DuplicateAddressProtocol() tcpip.NetworkProtocolNumber +} + +// LinkAddressResolver handles link address resolution for a network protocol. type LinkAddressResolver interface { // LinkAddressRequest sends a request for the link address of the target // address. The request is broadcasted on the local network if a remote link |