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-rw-r--r--pkg/tcpip/network/internal/ip/generic_multicast_protocol.go696
-rw-r--r--pkg/tcpip/network/internal/ip/stats.go100
2 files changed, 796 insertions, 0 deletions
diff --git a/pkg/tcpip/network/internal/ip/generic_multicast_protocol.go b/pkg/tcpip/network/internal/ip/generic_multicast_protocol.go
new file mode 100644
index 000000000..b9f129728
--- /dev/null
+++ b/pkg/tcpip/network/internal/ip/generic_multicast_protocol.go
@@ -0,0 +1,696 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package ip holds IPv4/IPv6 common utilities.
+package ip
+
+import (
+ "fmt"
+ "math/rand"
+ "time"
+
+ "gvisor.dev/gvisor/pkg/sync"
+ "gvisor.dev/gvisor/pkg/tcpip"
+)
+
+// hostState is the state a host may be in for a multicast group.
+type hostState int
+
+// The states below are generic across IGMPv2 (RFC 2236 section 6) and MLDv1
+// (RFC 2710 section 5). Even though the states are generic across both IGMPv2
+// and MLDv1, IGMPv2 terminology will be used.
+//
+// ______________receive query______________
+// | |
+// | _____send or receive report_____ |
+// | | | |
+// V | V |
+// +-------+ +-----------+ +------------+ +-------------------+ +--------+ |
+// | Non-M | | Pending-M | | Delaying-M | | Queued Delaying-M | | Idle-M | -
+// +-------+ +-----------+ +------------+ +-------------------+ +--------+
+// | ^ | ^ | ^ | ^
+// | | | | | | | |
+// ---------- ------- ---------- -------------
+// initialize new send inital fail to send send or receive
+// group membership report delayed report report
+//
+// Not shown in the diagram above, but any state may transition into the non
+// member state when a group is left.
+const (
+ // nonMember is the "'Non-Member' state, when the host does not belong to the
+ // group on the interface. This is the initial state for all memberships on
+ // all network interfaces; it requires no storage in the host."
+ //
+ // 'Non-Listener' is the MLDv1 term used to describe this state.
+ //
+ // This state is used to keep track of groups that have been joined locally,
+ // but without advertising the membership to the network.
+ nonMember hostState = iota
+
+ // pendingMember is a newly joined member that is waiting to successfully send
+ // the initial set of reports.
+ //
+ // This is not an RFC defined state; it is an implementation specific state to
+ // track that the initial report needs to be sent.
+ //
+ // MAY NOT transition to the idle member state from this state.
+ pendingMember
+
+ // delayingMember is the "'Delaying Member' state, when the host belongs to
+ // the group on the interface and has a report delay timer running for that
+ // membership."
+ //
+ // 'Delaying Listener' is the MLDv1 term used to describe this state.
+ delayingMember
+
+ // queuedDelayingMember is a delayingMember that failed to send a report after
+ // its delayed report timer fired. Hosts in this state are waiting to attempt
+ // retransmission of the delayed report.
+ //
+ // This is not an RFC defined state; it is an implementation specific state to
+ // track that the delayed report needs to be sent.
+ //
+ // May transition to idle member if a report is received for a group.
+ queuedDelayingMember
+
+ // idleMember is the "Idle Member" state, when the host belongs to the group
+ // on the interface and does not have a report delay timer running for that
+ // membership.
+ //
+ // 'Idle Listener' is the MLDv1 term used to describe this state.
+ idleMember
+)
+
+func (s hostState) isDelayingMember() bool {
+ switch s {
+ case nonMember, pendingMember, idleMember:
+ return false
+ case delayingMember, queuedDelayingMember:
+ return true
+ default:
+ panic(fmt.Sprintf("unrecognized host state = %d", s))
+ }
+}
+
+// multicastGroupState holds the Generic Multicast Protocol state for a
+// multicast group.
+type multicastGroupState struct {
+ // joins is the number of times the group has been joined.
+ joins uint64
+
+ // state holds the host's state for the group.
+ state hostState
+
+ // lastToSendReport is true if we sent the last report for the group. It is
+ // used to track whether there are other hosts on the subnet that are also
+ // members of the group.
+ //
+ // Defined in RFC 2236 section 6 page 9 for IGMPv2 and RFC 2710 section 5 page
+ // 8 for MLDv1.
+ lastToSendReport bool
+
+ // delayedReportJob is used to delay sending responses to membership report
+ // messages in order to reduce duplicate reports from multiple hosts on the
+ // interface.
+ //
+ // Must not be nil.
+ delayedReportJob *tcpip.Job
+
+ // delyedReportJobFiresAt is the time when the delayed report job will fire.
+ //
+ // A zero value indicates that the job is not scheduled.
+ delayedReportJobFiresAt time.Time
+}
+
+func (m *multicastGroupState) cancelDelayedReportJob() {
+ m.delayedReportJob.Cancel()
+ m.delayedReportJobFiresAt = time.Time{}
+}
+
+// GenericMulticastProtocolOptions holds options for the generic multicast
+// protocol.
+type GenericMulticastProtocolOptions struct {
+ // Rand is the source of random numbers.
+ Rand *rand.Rand
+
+ // Clock is the clock used to create timers.
+ Clock tcpip.Clock
+
+ // Protocol is the implementation of the variant of multicast group protocol
+ // in use.
+ Protocol MulticastGroupProtocol
+
+ // MaxUnsolicitedReportDelay is the maximum amount of time to wait between
+ // transmitting unsolicited reports.
+ //
+ // Unsolicited reports are transmitted when a group is newly joined.
+ MaxUnsolicitedReportDelay time.Duration
+
+ // AllNodesAddress is a multicast address that all nodes on a network should
+ // be a member of.
+ //
+ // This address will not have the generic multicast protocol performed on it;
+ // it will be left in the non member/listener state, and packets will never
+ // be sent for it.
+ AllNodesAddress tcpip.Address
+}
+
+// MulticastGroupProtocol is a multicast group protocol whose core state machine
+// can be represented by GenericMulticastProtocolState.
+type MulticastGroupProtocol interface {
+ // Enabled indicates whether the generic multicast protocol will be
+ // performed.
+ //
+ // When enabled, the protocol may transmit report and leave messages when
+ // joining and leaving multicast groups respectively, and handle incoming
+ // packets.
+ //
+ // When disabled, the protocol will still keep track of locally joined groups,
+ // it just won't transmit and handle packets, or update groups' state.
+ Enabled() bool
+
+ // SendReport sends a multicast report for the specified group address.
+ //
+ // Returns false if the caller should queue the report to be sent later. Note,
+ // returning false does not mean that the receiver hit an error.
+ SendReport(groupAddress tcpip.Address) (sent bool, err tcpip.Error)
+
+ // SendLeave sends a multicast leave for the specified group address.
+ SendLeave(groupAddress tcpip.Address) tcpip.Error
+}
+
+// GenericMulticastProtocolState is the per interface generic multicast protocol
+// state.
+//
+// There is actually no protocol named "Generic Multicast Protocol". Instead,
+// the term used to refer to a generic multicast protocol that applies to both
+// IPv4 and IPv6. Specifically, Generic Multicast Protocol is the core state
+// machine of IGMPv2 as defined by RFC 2236 and MLDv1 as defined by RFC 2710.
+//
+// Callers must synchronize accesses to the generic multicast protocol state;
+// GenericMulticastProtocolState obtains no locks in any of its methods. The
+// only exception to this is GenericMulticastProtocolState's timer/job callbacks
+// which will obtain the lock provided to the GenericMulticastProtocolState when
+// it is initialized.
+//
+// GenericMulticastProtocolState.Init MUST be called before calling any of
+// the methods on GenericMulticastProtocolState.
+//
+// GenericMulticastProtocolState.MakeAllNonMemberLocked MUST be called when the
+// multicast group protocol is disabled so that leave messages may be sent.
+type GenericMulticastProtocolState struct {
+ // Do not allow overwriting this state.
+ _ sync.NoCopy
+
+ opts GenericMulticastProtocolOptions
+
+ // memberships holds group addresses and their associated state.
+ memberships map[tcpip.Address]multicastGroupState
+
+ // protocolMU is the mutex used to protect the protocol.
+ protocolMU *sync.RWMutex
+}
+
+// Init initializes the Generic Multicast Protocol state.
+//
+// Must only be called once for the lifetime of g; Init will panic if it is
+// called twice.
+//
+// The GenericMulticastProtocolState will only grab the lock when timers/jobs
+// fire.
+//
+// Note: the methods on opts.Protocol will always be called while protocolMU is
+// held.
+func (g *GenericMulticastProtocolState) Init(protocolMU *sync.RWMutex, opts GenericMulticastProtocolOptions) {
+ if g.memberships != nil {
+ panic("attempted to initialize generic membership protocol state twice")
+ }
+
+ *g = GenericMulticastProtocolState{
+ opts: opts,
+ memberships: make(map[tcpip.Address]multicastGroupState),
+ protocolMU: protocolMU,
+ }
+}
+
+// MakeAllNonMemberLocked transitions all groups to the non-member state.
+//
+// The groups will still be considered joined locally.
+//
+// MUST be called when the multicast group protocol is disabled.
+//
+// Precondition: g.protocolMU must be locked.
+func (g *GenericMulticastProtocolState) MakeAllNonMemberLocked() {
+ if !g.opts.Protocol.Enabled() {
+ return
+ }
+
+ for groupAddress, info := range g.memberships {
+ g.transitionToNonMemberLocked(groupAddress, &info)
+ g.memberships[groupAddress] = info
+ }
+}
+
+// InitializeGroupsLocked initializes each group, as if they were newly joined
+// but without affecting the groups' join count.
+//
+// Must only be called after calling MakeAllNonMember as a group should not be
+// initialized while it is not in the non-member state.
+//
+// Precondition: g.protocolMU must be locked.
+func (g *GenericMulticastProtocolState) InitializeGroupsLocked() {
+ if !g.opts.Protocol.Enabled() {
+ return
+ }
+
+ for groupAddress, info := range g.memberships {
+ g.initializeNewMemberLocked(groupAddress, &info)
+ g.memberships[groupAddress] = info
+ }
+}
+
+// SendQueuedReportsLocked attempts to send reports for groups that failed to
+// send reports during their last attempt.
+//
+// Precondition: g.protocolMU must be locked.
+func (g *GenericMulticastProtocolState) SendQueuedReportsLocked() {
+ for groupAddress, info := range g.memberships {
+ switch info.state {
+ case nonMember, delayingMember, idleMember:
+ case pendingMember:
+ // pendingMembers failed to send their initial unsolicited report so try
+ // to send the report and queue the extra unsolicited reports.
+ g.maybeSendInitialReportLocked(groupAddress, &info)
+ case queuedDelayingMember:
+ // queuedDelayingMembers failed to send their delayed reports so try to
+ // send the report and transition them to the idle state.
+ g.maybeSendDelayedReportLocked(groupAddress, &info)
+ default:
+ panic(fmt.Sprintf("unrecognized host state = %d", info.state))
+ }
+ g.memberships[groupAddress] = info
+ }
+}
+
+// JoinGroupLocked handles joining a new group.
+//
+// Precondition: g.protocolMU must be locked.
+func (g *GenericMulticastProtocolState) JoinGroupLocked(groupAddress tcpip.Address) {
+ if info, ok := g.memberships[groupAddress]; ok {
+ // The group has already been joined.
+ info.joins++
+ g.memberships[groupAddress] = info
+ return
+ }
+
+ info := multicastGroupState{
+ // Since we just joined the group, its count is 1.
+ joins: 1,
+ // The state will be updated below, if required.
+ state: nonMember,
+ lastToSendReport: false,
+ delayedReportJob: tcpip.NewJob(g.opts.Clock, g.protocolMU, func() {
+ if !g.opts.Protocol.Enabled() {
+ panic(fmt.Sprintf("delayed report job fired for group %s while the multicast group protocol is disabled", groupAddress))
+ }
+
+ info, ok := g.memberships[groupAddress]
+ if !ok {
+ panic(fmt.Sprintf("expected to find group state for group = %s", groupAddress))
+ }
+
+ g.maybeSendDelayedReportLocked(groupAddress, &info)
+ g.memberships[groupAddress] = info
+ }),
+ }
+
+ if g.opts.Protocol.Enabled() {
+ g.initializeNewMemberLocked(groupAddress, &info)
+ }
+
+ g.memberships[groupAddress] = info
+}
+
+// IsLocallyJoinedRLocked returns true if the group is locally joined.
+//
+// Precondition: g.protocolMU must be read locked.
+func (g *GenericMulticastProtocolState) IsLocallyJoinedRLocked(groupAddress tcpip.Address) bool {
+ _, ok := g.memberships[groupAddress]
+ return ok
+}
+
+// LeaveGroupLocked handles leaving the group.
+//
+// Returns false if the group is not currently joined.
+//
+// Precondition: g.protocolMU must be locked.
+func (g *GenericMulticastProtocolState) LeaveGroupLocked(groupAddress tcpip.Address) bool {
+ info, ok := g.memberships[groupAddress]
+ if !ok {
+ return false
+ }
+
+ if info.joins == 0 {
+ panic(fmt.Sprintf("tried to leave group %s with a join count of 0", groupAddress))
+ }
+ info.joins--
+ if info.joins != 0 {
+ // If we still have outstanding joins, then do nothing further.
+ g.memberships[groupAddress] = info
+ return true
+ }
+
+ g.transitionToNonMemberLocked(groupAddress, &info)
+ delete(g.memberships, groupAddress)
+ return true
+}
+
+// HandleQueryLocked handles a query message with the specified maximum response
+// time.
+//
+// If the group address is unspecified, then reports will be scheduled for all
+// joined groups.
+//
+// Report(s) will be scheduled to be sent after a random duration between 0 and
+// the maximum response time.
+//
+// Precondition: g.protocolMU must be locked.
+func (g *GenericMulticastProtocolState) HandleQueryLocked(groupAddress tcpip.Address, maxResponseTime time.Duration) {
+ if !g.opts.Protocol.Enabled() {
+ return
+ }
+
+ // As per RFC 2236 section 2.4 (for IGMPv2),
+ //
+ // In a Membership Query message, the group address field is set to zero
+ // when sending a General Query, and set to the group address being
+ // queried when sending a Group-Specific Query.
+ //
+ // As per RFC 2710 section 3.6 (for MLDv1),
+ //
+ // In a Query message, the Multicast Address field is set to zero when
+ // sending a General Query, and set to a specific IPv6 multicast address
+ // when sending a Multicast-Address-Specific Query.
+ if groupAddress.Unspecified() {
+ // This is a general query as the group address is unspecified.
+ for groupAddress, info := range g.memberships {
+ g.setDelayTimerForAddressRLocked(groupAddress, &info, maxResponseTime)
+ g.memberships[groupAddress] = info
+ }
+ } else if info, ok := g.memberships[groupAddress]; ok {
+ g.setDelayTimerForAddressRLocked(groupAddress, &info, maxResponseTime)
+ g.memberships[groupAddress] = info
+ }
+}
+
+// HandleReportLocked handles a report message.
+//
+// If the report is for a joined group, any active delayed report will be
+// cancelled and the host state for the group transitions to idle.
+//
+// Precondition: g.protocolMU must be locked.
+func (g *GenericMulticastProtocolState) HandleReportLocked(groupAddress tcpip.Address) {
+ if !g.opts.Protocol.Enabled() {
+ return
+ }
+
+ // As per RFC 2236 section 3 pages 3-4 (for IGMPv2),
+ //
+ // If the host receives another host's Report (version 1 or 2) while it has
+ // a timer running, it stops its timer for the specified group and does not
+ // send a Report
+ //
+ // As per RFC 2710 section 4 page 6 (for MLDv1),
+ //
+ // If a node receives another node's Report from an interface for a
+ // multicast address while it has a timer running for that same address
+ // on that interface, it stops its timer and does not send a Report for
+ // that address, thus suppressing duplicate reports on the link.
+ if info, ok := g.memberships[groupAddress]; ok && info.state.isDelayingMember() {
+ info.cancelDelayedReportJob()
+ info.lastToSendReport = false
+ info.state = idleMember
+ g.memberships[groupAddress] = info
+ }
+}
+
+// initializeNewMemberLocked initializes a new group membership.
+//
+// Precondition: g.protocolMU must be locked.
+func (g *GenericMulticastProtocolState) initializeNewMemberLocked(groupAddress tcpip.Address, info *multicastGroupState) {
+ if info.state != nonMember {
+ panic(fmt.Sprintf("host must be in non-member state to be initialized; group = %s, state = %d", groupAddress, info.state))
+ }
+
+ info.lastToSendReport = false
+
+ if groupAddress == g.opts.AllNodesAddress {
+ // As per RFC 2236 section 6 page 10 (for IGMPv2),
+ //
+ // The all-systems group (address 224.0.0.1) is handled as a special
+ // case. The host starts in Idle Member state for that group on every
+ // interface, never transitions to another state, and never sends a
+ // report for that group.
+ //
+ // As per RFC 2710 section 5 page 10 (for MLDv1),
+ //
+ // The link-scope all-nodes address (FF02::1) is handled as a special
+ // case. The node starts in Idle Listener state for that address on
+ // every interface, never transitions to another state, and never sends
+ // a Report or Done for that address.
+ info.state = idleMember
+ return
+ }
+
+ info.state = pendingMember
+ g.maybeSendInitialReportLocked(groupAddress, info)
+}
+
+// maybeSendInitialReportLocked attempts to start transmission of the initial
+// set of reports after newly joining a group.
+//
+// Host must be in pending member state.
+//
+// Precondition: g.protocolMU must be locked.
+func (g *GenericMulticastProtocolState) maybeSendInitialReportLocked(groupAddress tcpip.Address, info *multicastGroupState) {
+ if info.state != pendingMember {
+ panic(fmt.Sprintf("host must be in pending member state to send initial reports; group = %s, state = %d", groupAddress, info.state))
+ }
+
+ // As per RFC 2236 section 3 page 5 (for IGMPv2),
+ //
+ // When a host joins a multicast group, it should immediately transmit an
+ // unsolicited Version 2 Membership Report for that group" ... "it is
+ // recommended that it be repeated".
+ //
+ // As per RFC 2710 section 4 page 6 (for MLDv1),
+ //
+ // When a node starts listening to a multicast address on an interface,
+ // it should immediately transmit an unsolicited Report for that address
+ // on that interface, in case it is the first listener on the link. To
+ // cover the possibility of the initial Report being lost or damaged, it
+ // is recommended that it be repeated once or twice after short delays
+ // [Unsolicited Report Interval].
+ //
+ // TODO(gvisor.dev/issue/4901): Support a configurable number of initial
+ // unsolicited reports.
+ sent, err := g.opts.Protocol.SendReport(groupAddress)
+ if err == nil && sent {
+ info.lastToSendReport = true
+ g.setDelayTimerForAddressRLocked(groupAddress, info, g.opts.MaxUnsolicitedReportDelay)
+ }
+}
+
+// maybeSendDelayedReportLocked attempts to send the delayed report.
+//
+// Host must be in pending, delaying or queued delaying member state.
+//
+// Precondition: g.protocolMU must be locked.
+func (g *GenericMulticastProtocolState) maybeSendDelayedReportLocked(groupAddress tcpip.Address, info *multicastGroupState) {
+ if !info.state.isDelayingMember() {
+ panic(fmt.Sprintf("host must be in delaying or queued delaying member state to send delayed reports; group = %s, state = %d", groupAddress, info.state))
+ }
+
+ sent, err := g.opts.Protocol.SendReport(groupAddress)
+ if err == nil && sent {
+ info.lastToSendReport = true
+ info.state = idleMember
+ } else {
+ info.state = queuedDelayingMember
+ }
+}
+
+// maybeSendLeave attempts to send a leave message.
+func (g *GenericMulticastProtocolState) maybeSendLeave(groupAddress tcpip.Address, lastToSendReport bool) {
+ if !g.opts.Protocol.Enabled() || !lastToSendReport {
+ return
+ }
+
+ if groupAddress == g.opts.AllNodesAddress {
+ // As per RFC 2236 section 6 page 10 (for IGMPv2),
+ //
+ // The all-systems group (address 224.0.0.1) is handled as a special
+ // case. The host starts in Idle Member state for that group on every
+ // interface, never transitions to another state, and never sends a
+ // report for that group.
+ //
+ // As per RFC 2710 section 5 page 10 (for MLDv1),
+ //
+ // The link-scope all-nodes address (FF02::1) is handled as a special
+ // case. The node starts in Idle Listener state for that address on
+ // every interface, never transitions to another state, and never sends
+ // a Report or Done for that address.
+ return
+ }
+
+ // Okay to ignore the error here as if packet write failed, the multicast
+ // routers will eventually drop our membership anyways. If the interface is
+ // being disabled or removed, the generic multicast protocol's should be
+ // cleared eventually.
+ //
+ // As per RFC 2236 section 3 page 5 (for IGMPv2),
+ //
+ // When a router receives a Report, it adds the group being reported to
+ // the list of multicast group memberships on the network on which it
+ // received the Report and sets the timer for the membership to the
+ // [Group Membership Interval]. Repeated Reports refresh the timer. If
+ // no Reports are received for a particular group before this timer has
+ // expired, the router assumes that the group has no local members and
+ // that it need not forward remotely-originated multicasts for that
+ // group onto the attached network.
+ //
+ // As per RFC 2710 section 4 page 5 (for MLDv1),
+ //
+ // When a router receives a Report from a link, if the reported address
+ // is not already present in the router's list of multicast address
+ // having listeners on that link, the reported address is added to the
+ // list, its timer is set to [Multicast Listener Interval], and its
+ // appearance is made known to the router's multicast routing component.
+ // If a Report is received for a multicast address that is already
+ // present in the router's list, the timer for that address is reset to
+ // [Multicast Listener Interval]. If an address's timer expires, it is
+ // assumed that there are no longer any listeners for that address
+ // present on the link, so it is deleted from the list and its
+ // disappearance is made known to the multicast routing component.
+ //
+ // The requirement to send a leave message is also optional (it MAY be
+ // skipped):
+ //
+ // As per RFC 2236 section 6 page 8 (for IGMPv2),
+ //
+ // "send leave" for the group on the interface. If the interface
+ // state says the Querier is running IGMPv1, this action SHOULD be
+ // skipped. If the flag saying we were the last host to report is
+ // cleared, this action MAY be skipped. The Leave Message is sent to
+ // the ALL-ROUTERS group (224.0.0.2).
+ //
+ // As per RFC 2710 section 5 page 8 (for MLDv1),
+ //
+ // "send done" for the address on the interface. If the flag saying
+ // we were the last node to report is cleared, this action MAY be
+ // skipped. The Done message is sent to the link-scope all-routers
+ // address (FF02::2).
+ _ = g.opts.Protocol.SendLeave(groupAddress)
+}
+
+// transitionToNonMemberLocked transitions the given multicast group the the
+// non-member/listener state.
+//
+// Precondition: g.protocolMU must be locked.
+func (g *GenericMulticastProtocolState) transitionToNonMemberLocked(groupAddress tcpip.Address, info *multicastGroupState) {
+ if info.state == nonMember {
+ return
+ }
+
+ info.cancelDelayedReportJob()
+ g.maybeSendLeave(groupAddress, info.lastToSendReport)
+ info.lastToSendReport = false
+ info.state = nonMember
+}
+
+// setDelayTimerForAddressRLocked sets timer to send a delay report.
+//
+// Precondition: g.protocolMU MUST be read locked.
+func (g *GenericMulticastProtocolState) setDelayTimerForAddressRLocked(groupAddress tcpip.Address, info *multicastGroupState, maxResponseTime time.Duration) {
+ if info.state == nonMember {
+ return
+ }
+
+ if groupAddress == g.opts.AllNodesAddress {
+ // As per RFC 2236 section 6 page 10 (for IGMPv2),
+ //
+ // The all-systems group (address 224.0.0.1) is handled as a special
+ // case. The host starts in Idle Member state for that group on every
+ // interface, never transitions to another state, and never sends a
+ // report for that group.
+ //
+ // As per RFC 2710 section 5 page 10 (for MLDv1),
+ //
+ // The link-scope all-nodes address (FF02::1) is handled as a special
+ // case. The node starts in Idle Listener state for that address on
+ // every interface, never transitions to another state, and never sends
+ // a Report or Done for that address.
+ return
+ }
+
+ // As per RFC 2236 section 3 page 3 (for IGMPv2),
+ //
+ // If a timer for the group is already unning, it is reset to the random
+ // value only if the requested Max Response Time is less than the remaining
+ // value of the running timer.
+ //
+ // As per RFC 2710 section 4 page 5 (for MLDv1),
+ //
+ // If a timer for any address is already running, it is reset to the new
+ // random value only if the requested Maximum Response Delay is less than
+ // the remaining value of the running timer.
+ now := time.Unix(0 /* seconds */, g.opts.Clock.NowNanoseconds())
+ if info.state == delayingMember {
+ if info.delayedReportJobFiresAt.IsZero() {
+ panic(fmt.Sprintf("delayed report unscheduled while in the delaying member state; group = %s", groupAddress))
+ }
+
+ if info.delayedReportJobFiresAt.Sub(now) <= maxResponseTime {
+ // The timer is scheduled to fire before the maximum response time so we
+ // leave our timer as is.
+ return
+ }
+ }
+
+ info.state = delayingMember
+ info.cancelDelayedReportJob()
+ maxResponseTime = g.calculateDelayTimerDuration(maxResponseTime)
+ info.delayedReportJob.Schedule(maxResponseTime)
+ info.delayedReportJobFiresAt = now.Add(maxResponseTime)
+}
+
+// calculateDelayTimerDuration returns a random time between (0, maxRespTime].
+func (g *GenericMulticastProtocolState) calculateDelayTimerDuration(maxRespTime time.Duration) time.Duration {
+ // As per RFC 2236 section 3 page 3 (for IGMPv2),
+ //
+ // When a host receives a Group-Specific Query, it sets a delay timer to a
+ // random value selected from the range (0, Max Response Time]...
+ //
+ // As per RFC 2710 section 4 page 6 (for MLDv1),
+ //
+ // When a node receives a Multicast-Address-Specific Query, if it is
+ // listening to the queried Multicast Address on the interface from
+ // which the Query was received, it sets a delay timer for that address
+ // to a random value selected from the range [0, Maximum Response Delay],
+ // as above.
+ if maxRespTime == 0 {
+ return 0
+ }
+ return time.Duration(g.opts.Rand.Int63n(int64(maxRespTime)))
+}
diff --git a/pkg/tcpip/network/internal/ip/stats.go b/pkg/tcpip/network/internal/ip/stats.go
new file mode 100644
index 000000000..898f8b356
--- /dev/null
+++ b/pkg/tcpip/network/internal/ip/stats.go
@@ -0,0 +1,100 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ip
+
+import "gvisor.dev/gvisor/pkg/tcpip"
+
+// LINT.IfChange(MultiCounterIPStats)
+
+// MultiCounterIPStats holds IP statistics, each counter may have several
+// versions.
+type MultiCounterIPStats struct {
+ // PacketsReceived is the total number of IP packets received from the link
+ // layer.
+ PacketsReceived tcpip.MultiCounterStat
+
+ // DisabledPacketsReceived is the total number of IP packets received from the
+ // link layer when the IP layer is disabled.
+ DisabledPacketsReceived tcpip.MultiCounterStat
+
+ // InvalidDestinationAddressesReceived is the total number of IP packets
+ // received with an unknown or invalid destination address.
+ InvalidDestinationAddressesReceived tcpip.MultiCounterStat
+
+ // InvalidSourceAddressesReceived is the total number of IP packets received
+ // with a source address that should never have been received on the wire.
+ InvalidSourceAddressesReceived tcpip.MultiCounterStat
+
+ // PacketsDelivered is the total number of incoming IP packets that are
+ // successfully delivered to the transport layer.
+ PacketsDelivered tcpip.MultiCounterStat
+
+ // PacketsSent is the total number of IP packets sent via WritePacket.
+ PacketsSent tcpip.MultiCounterStat
+
+ // OutgoingPacketErrors is the total number of IP packets which failed to
+ // write to a link-layer endpoint.
+ OutgoingPacketErrors tcpip.MultiCounterStat
+
+ // MalformedPacketsReceived is the total number of IP Packets that were
+ // dropped due to the IP packet header failing validation checks.
+ MalformedPacketsReceived tcpip.MultiCounterStat
+
+ // MalformedFragmentsReceived is the total number of IP Fragments that were
+ // dropped due to the fragment failing validation checks.
+ MalformedFragmentsReceived tcpip.MultiCounterStat
+
+ // IPTablesPreroutingDropped is the total number of IP packets dropped in the
+ // Prerouting chain.
+ IPTablesPreroutingDropped tcpip.MultiCounterStat
+
+ // IPTablesInputDropped is the total number of IP packets dropped in the Input
+ // chain.
+ IPTablesInputDropped tcpip.MultiCounterStat
+
+ // IPTablesOutputDropped is the total number of IP packets dropped in the
+ // Output chain.
+ IPTablesOutputDropped tcpip.MultiCounterStat
+
+ // OptionTSReceived is the number of Timestamp options seen.
+ OptionTSReceived tcpip.MultiCounterStat
+
+ // OptionRRReceived is the number of Record Route options seen.
+ OptionRRReceived tcpip.MultiCounterStat
+
+ // OptionUnknownReceived is the number of unknown IP options seen.
+ OptionUnknownReceived tcpip.MultiCounterStat
+}
+
+// Init sets internal counters to track a and b counters.
+func (m *MultiCounterIPStats) Init(a, b *tcpip.IPStats) {
+ m.PacketsReceived.Init(a.PacketsReceived, b.PacketsReceived)
+ m.DisabledPacketsReceived.Init(a.DisabledPacketsReceived, b.DisabledPacketsReceived)
+ m.InvalidDestinationAddressesReceived.Init(a.InvalidDestinationAddressesReceived, b.InvalidDestinationAddressesReceived)
+ m.InvalidSourceAddressesReceived.Init(a.InvalidSourceAddressesReceived, b.InvalidSourceAddressesReceived)
+ m.PacketsDelivered.Init(a.PacketsDelivered, b.PacketsDelivered)
+ m.PacketsSent.Init(a.PacketsSent, b.PacketsSent)
+ m.OutgoingPacketErrors.Init(a.OutgoingPacketErrors, b.OutgoingPacketErrors)
+ m.MalformedPacketsReceived.Init(a.MalformedPacketsReceived, b.MalformedPacketsReceived)
+ m.MalformedFragmentsReceived.Init(a.MalformedFragmentsReceived, b.MalformedFragmentsReceived)
+ m.IPTablesPreroutingDropped.Init(a.IPTablesPreroutingDropped, b.IPTablesPreroutingDropped)
+ m.IPTablesInputDropped.Init(a.IPTablesInputDropped, b.IPTablesInputDropped)
+ m.IPTablesOutputDropped.Init(a.IPTablesOutputDropped, b.IPTablesOutputDropped)
+ m.OptionTSReceived.Init(a.OptionTSReceived, b.OptionTSReceived)
+ m.OptionRRReceived.Init(a.OptionRRReceived, b.OptionRRReceived)
+ m.OptionUnknownReceived.Init(a.OptionUnknownReceived, b.OptionUnknownReceived)
+}
+
+// LINT.ThenChange(:MultiCounterIPStats, ../../tcpip.go:IPStats)