summaryrefslogtreecommitdiffhomepage
path: root/pkg/tcpip/network/ipv4
diff options
context:
space:
mode:
Diffstat (limited to 'pkg/tcpip/network/ipv4')
-rw-r--r--pkg/tcpip/network/ipv4/igmp.go57
-rw-r--r--pkg/tcpip/network/ipv4/ipv4.go85
2 files changed, 101 insertions, 41 deletions
diff --git a/pkg/tcpip/network/ipv4/igmp.go b/pkg/tcpip/network/ipv4/igmp.go
index c9bf117de..37f1822ca 100644
--- a/pkg/tcpip/network/ipv4/igmp.go
+++ b/pkg/tcpip/network/ipv4/igmp.go
@@ -51,6 +51,16 @@ const (
UnsolicitedReportIntervalMax = 10 * time.Second
)
+// IGMPOptions holds options for IGMP.
+type IGMPOptions struct {
+ // Enabled indicates whether IGMP will be performed.
+ //
+ // When enabled, IGMP may transmit IGMP report and leave messages when
+ // joining and leaving multicast groups respectively, and handle incoming
+ // IGMP packets.
+ Enabled bool
+}
+
var _ ip.MulticastGroupProtocol = (*igmpState)(nil)
// igmpState is the per-interface IGMP state.
@@ -58,7 +68,8 @@ var _ ip.MulticastGroupProtocol = (*igmpState)(nil)
// igmpState.init() MUST be called after creating an IGMP state.
type igmpState struct {
// The IPv4 endpoint this igmpState is for.
- ep *endpoint
+ ep *endpoint
+ opts IGMPOptions
// igmpV1Present is for maintaining compatibility with IGMPv1 Routers, from
// RFC 2236 Section 4 Page 6: "The IGMPv1 router expects Version 1
@@ -108,10 +119,11 @@ func (igmp *igmpState) SendLeave(groupAddress tcpip.Address) *tcpip.Error {
// init sets up an igmpState struct, and is required to be called before using
// a new igmpState.
-func (igmp *igmpState) init(ep *endpoint) {
+func (igmp *igmpState) init(ep *endpoint, opts IGMPOptions) {
igmp.mu.Lock()
defer igmp.mu.Unlock()
igmp.ep = ep
+ igmp.opts = opts
igmp.mu.genericMulticastProtocol.Init(ep.protocol.stack.Rand(), ep.protocol.stack.Clock(), igmp, UnsolicitedReportIntervalMax)
igmp.igmpV1Present = igmpV1PresentDefault
igmp.mu.igmpV1Job = igmp.ep.protocol.stack.NewJob(&igmp.mu, func() {
@@ -189,6 +201,10 @@ func (igmp *igmpState) setV1Present(v bool) {
}
func (igmp *igmpState) handleMembershipQuery(groupAddress tcpip.Address, maxRespTime time.Duration) {
+ if !igmp.opts.Enabled {
+ return
+ }
+
igmp.mu.Lock()
defer igmp.mu.Unlock()
@@ -206,6 +222,10 @@ func (igmp *igmpState) handleMembershipQuery(groupAddress tcpip.Address, maxResp
}
func (igmp *igmpState) handleMembershipReport(groupAddress tcpip.Address) {
+ if !igmp.opts.Enabled {
+ return
+ }
+
igmp.mu.Lock()
defer igmp.mu.Unlock()
igmp.mu.genericMulticastProtocol.HandleReport(groupAddress)
@@ -226,11 +246,8 @@ func (igmp *igmpState) writePacket(destAddress tcpip.Address, groupAddress tcpip
// TODO(gvisor.dev/issue/4888): We should not use the unspecified address,
// rather we should select an appropriate local address.
- r := stack.Route{
- LocalAddress: header.IPv4Any,
- RemoteAddress: destAddress,
- }
- igmp.ep.addIPHeader(&r, pkt, stack.NetworkHeaderParams{
+ localAddr := header.IPv4Any
+ igmp.ep.addIPHeader(localAddr, destAddress, pkt, stack.NetworkHeaderParams{
Protocol: header.IGMPProtocolNumber,
TTL: header.IGMPTTL,
TOS: stack.DefaultTOS,
@@ -239,7 +256,7 @@ func (igmp *igmpState) writePacket(destAddress tcpip.Address, groupAddress tcpip
// TODO(b/162198658): set the ROUTER_ALERT option when sending Host
// Membership Reports.
sent := igmp.ep.protocol.stack.Stats().IGMP.PacketsSent
- if err := igmp.ep.nic.WritePacketToRemote(header.EthernetAddressFromMulticastIPv4Address(destAddress), nil /* gso */, header.IPv4ProtocolNumber, pkt); err != nil {
+ if err := igmp.ep.nic.WritePacketToRemote(header.EthernetAddressFromMulticastIPv4Address(destAddress), nil /* gso */, ProtocolNumber, pkt); err != nil {
sent.Dropped.Increment()
return err
}
@@ -263,6 +280,26 @@ func (igmp *igmpState) writePacket(destAddress tcpip.Address, groupAddress tcpip
// If the group already exists in the membership map, returns
// tcpip.ErrDuplicateAddress.
func (igmp *igmpState) joinGroup(groupAddress tcpip.Address) *tcpip.Error {
+ if !igmp.opts.Enabled {
+ return nil
+ }
+
+ // As per RFC 2236 section 6 page 10,
+ //
+ // 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.
+ //
+ // This is equivalent to not performing IGMP for the all-systems multicast
+ // address. Simply not performing IGMP when the group is added will prevent
+ // any work from being done on the all-systems multicast group when leaving
+ // the group or when query or report messages are received for it since the
+ // MGP state will not know about it.
+ if groupAddress == header.IPv4AllSystems {
+ return nil
+ }
+
igmp.mu.Lock()
defer igmp.mu.Unlock()
@@ -280,6 +317,10 @@ func (igmp *igmpState) joinGroup(groupAddress tcpip.Address) *tcpip.Error {
// If the group does not exist in the membership map, this function will
// silently return.
func (igmp *igmpState) leaveGroup(groupAddress tcpip.Address) {
+ if !igmp.opts.Enabled {
+ return
+ }
+
igmp.mu.Lock()
defer igmp.mu.Unlock()
igmp.mu.genericMulticastProtocol.LeaveGroup(groupAddress)
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go
index 7c759be9a..be9c8e2f9 100644
--- a/pkg/tcpip/network/ipv4/ipv4.go
+++ b/pkg/tcpip/network/ipv4/ipv4.go
@@ -95,7 +95,7 @@ func (p *protocol) NewEndpoint(nic stack.NetworkInterface, _ stack.LinkAddressCa
protocol: p,
}
e.mu.addressableEndpointState.Init(e)
- e.igmp.init(e)
+ e.igmp.init(e, p.options.IGMP)
return e
}
@@ -126,7 +126,7 @@ func (e *endpoint) Enable() *tcpip.Error {
// As per RFC 1122 section 3.3.7, all hosts should join the all-hosts
// multicast group. Note, the IANA calls the all-hosts multicast group the
// all-systems multicast group.
- _, err = e.mu.addressableEndpointState.JoinGroup(header.IPv4AllSystems)
+ _, err = e.joinGroupLocked(header.IPv4AllSystems)
return err
}
@@ -164,7 +164,7 @@ func (e *endpoint) disableLocked() {
}
// The endpoint may have already left the multicast group.
- if _, err := e.mu.addressableEndpointState.LeaveGroup(header.IPv4AllSystems); err != nil && err != tcpip.ErrBadLocalAddress {
+ if _, err := e.leaveGroupLocked(header.IPv4AllSystems); err != nil && err != tcpip.ErrBadLocalAddress {
panic(fmt.Sprintf("unexpected error when leaving group = %s: %s", header.IPv4AllSystems, err))
}
@@ -200,7 +200,7 @@ func (e *endpoint) NetworkProtocolNumber() tcpip.NetworkProtocolNumber {
return e.protocol.Number()
}
-func (e *endpoint) addIPHeader(r *stack.Route, pkt *stack.PacketBuffer, params stack.NetworkHeaderParams) {
+func (e *endpoint) addIPHeader(srcAddr, dstAddr tcpip.Address, pkt *stack.PacketBuffer, params stack.NetworkHeaderParams) {
hdrLen := header.IPv4MinimumSize
var opts header.IPv4Options
if params.Options != nil {
@@ -221,15 +221,15 @@ func (e *endpoint) addIPHeader(r *stack.Route, pkt *stack.PacketBuffer, params s
// RFC 6864 section 4.3 mandates uniqueness of ID values for non-atomic
// datagrams. Since the DF bit is never being set here, all datagrams
// are non-atomic and need an ID.
- id := atomic.AddUint32(&e.protocol.ids[hashRoute(r, params.Protocol, e.protocol.hashIV)%buckets], 1)
+ id := atomic.AddUint32(&e.protocol.ids[hashRoute(srcAddr, dstAddr, params.Protocol, e.protocol.hashIV)%buckets], 1)
ip.Encode(&header.IPv4Fields{
TotalLength: length,
ID: uint16(id),
TTL: params.TTL,
TOS: params.TOS,
Protocol: uint8(params.Protocol),
- SrcAddr: r.LocalAddress,
- DstAddr: r.RemoteAddress,
+ SrcAddr: srcAddr,
+ DstAddr: dstAddr,
Options: opts,
})
ip.SetChecksum(^ip.CalculateChecksum())
@@ -261,7 +261,7 @@ func (e *endpoint) handleFragments(r *stack.Route, gso *stack.GSO, networkMTU ui
// WritePacket writes a packet to the given destination address and protocol.
func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, params stack.NetworkHeaderParams, pkt *stack.PacketBuffer) *tcpip.Error {
- e.addIPHeader(r, pkt, params)
+ e.addIPHeader(r.LocalAddress, r.RemoteAddress, pkt, params)
// iptables filtering. All packets that reach here are locally
// generated.
@@ -349,7 +349,7 @@ func (e *endpoint) WritePackets(r *stack.Route, gso *stack.GSO, pkts stack.Packe
}
for pkt := pkts.Front(); pkt != nil; pkt = pkt.Next() {
- e.addIPHeader(r, pkt, params)
+ e.addIPHeader(r.LocalAddress, r.RemoteAddress, pkt, params)
networkMTU, err := calculateNetworkMTU(e.nic.MTU(), uint32(pkt.NetworkHeader().View().Size()))
if err != nil {
r.Stats().IP.OutgoingPacketErrors.IncrementBy(uint64(pkts.Len()))
@@ -463,7 +463,7 @@ func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, pkt *stack.PacketBu
// non-atomic datagrams, so assign an ID to all such datagrams
// according to the definition given in RFC 6864 section 4.
if ip.Flags()&header.IPv4FlagDontFragment == 0 || ip.Flags()&header.IPv4FlagMoreFragments != 0 || ip.FragmentOffset() > 0 {
- ip.SetID(uint16(atomic.AddUint32(&e.protocol.ids[hashRoute(r, 0 /* protocol */, e.protocol.hashIV)%buckets], 1)))
+ ip.SetID(uint16(atomic.AddUint32(&e.protocol.ids[hashRoute(r.LocalAddress, r.RemoteAddress, 0 /* protocol */, e.protocol.hashIV)%buckets], 1)))
}
}
@@ -706,10 +706,7 @@ func (e *endpoint) handlePacket(pkt *stack.PacketBuffer) {
return
}
if p == header.IGMPProtocolNumber {
- if e.protocol.options.IGMPEnabled {
- e.igmp.handleIGMP(pkt)
- }
- // Nothing further to do with an IGMP packet, even if IGMP is not enabled.
+ e.igmp.handleIGMP(pkt)
return
}
if opts := h.Options(); len(opts) != 0 {
@@ -837,32 +834,55 @@ func (e *endpoint) PermanentAddresses() []tcpip.AddressWithPrefix {
// JoinGroup implements stack.GroupAddressableEndpoint.
func (e *endpoint) JoinGroup(addr tcpip.Address) (bool, *tcpip.Error) {
+ e.mu.Lock()
+ defer e.mu.Unlock()
+ return e.joinGroupLocked(addr)
+}
+
+// joinGroupLocked is like JoinGroup, but with locking requirements.
+//
+// Precondition: e.mu must be locked.
+func (e *endpoint) joinGroupLocked(addr tcpip.Address) (bool, *tcpip.Error) {
if !header.IsV4MulticastAddress(addr) {
return false, tcpip.ErrBadAddress
}
+ // TODO(gvisor.dev/issue/4916): Keep track of join count and IGMP state in a
+ // single type.
+ joined, err := e.mu.addressableEndpointState.JoinGroup(addr)
+ if err != nil || !joined {
+ return joined, err
+ }
- e.mu.Lock()
- defer e.mu.Unlock()
-
- joinedGroup, err := e.mu.addressableEndpointState.JoinGroup(addr)
- if err == nil && joinedGroup && e.protocol.options.IGMPEnabled {
- _ = e.igmp.joinGroup(addr)
+ // joinGroup only returns an error if we try to join a group twice, but we
+ // checked above to make sure that the group was newly joined.
+ if err := e.igmp.joinGroup(addr); err != nil {
+ panic(fmt.Sprintf("e.igmp.joinGroup(%s): %s", addr, err))
}
- return joinedGroup, err
+ return true, nil
}
// LeaveGroup implements stack.GroupAddressableEndpoint.
func (e *endpoint) LeaveGroup(addr tcpip.Address) (bool, *tcpip.Error) {
e.mu.Lock()
defer e.mu.Unlock()
+ return e.leaveGroupLocked(addr)
+}
+
+// leaveGroupLocked is like LeaveGroup, but with locking requirements.
+//
+// Precondition: e.mu must be locked.
+func (e *endpoint) leaveGroupLocked(addr tcpip.Address) (bool, *tcpip.Error) {
+ left, err := e.mu.addressableEndpointState.LeaveGroup(addr)
+ if err != nil {
+ return left, err
+ }
- leftGroup, err := e.mu.addressableEndpointState.LeaveGroup(addr)
- if err == nil && leftGroup && e.protocol.options.IGMPEnabled {
+ if left {
e.igmp.leaveGroup(addr)
}
- return leftGroup, err
+ return left, nil
}
// IsInGroup implements stack.GroupAddressableEndpoint.
@@ -1021,20 +1041,19 @@ func addressToUint32(addr tcpip.Address) uint32 {
return uint32(addr[0]) | uint32(addr[1])<<8 | uint32(addr[2])<<16 | uint32(addr[3])<<24
}
-// hashRoute calculates a hash value for the given route. It uses the source &
-// destination address, the transport protocol number and a 32-bit number to
-// generate the hash.
-func hashRoute(r *stack.Route, protocol tcpip.TransportProtocolNumber, hashIV uint32) uint32 {
- a := addressToUint32(r.LocalAddress)
- b := addressToUint32(r.RemoteAddress)
+// hashRoute calculates a hash value for the given source/destination pair using
+// the addresses, transport protocol number and a 32-bit number to generate the
+// hash.
+func hashRoute(srcAddr, dstAddr tcpip.Address, protocol tcpip.TransportProtocolNumber, hashIV uint32) uint32 {
+ a := addressToUint32(srcAddr)
+ b := addressToUint32(dstAddr)
return hash.Hash3Words(a, b, uint32(protocol), hashIV)
}
// Options holds options to configure a new protocol.
type Options struct {
- // IGMPEnabled indicates whether incoming IGMP packets will be handled and if
- // this endpoint will transmit IGMP packets on IGMP related events.
- IGMPEnabled bool
+ // IGMP holds options for IGMP.
+ IGMP IGMPOptions
}
// NewProtocolWithOptions returns an IPv4 network protocol.
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-20 17:32:39 +0000