diff options
| author | Ghanan Gowripalan <ghanan@google.com> | 2020-12-09 10:50:42 -0800 |
|---|---|---|
| committer | Shentubot <shentubot@google.com> | 2020-12-09 15:54:18 -0800 |
| commit | 50189b0d6f2401f842f63ae149de13b89b4c30f9 (patch) | |
| tree | c5402d8fb9d4589364b3449ed6a027f1b24833e6 /pkg/tcpip/network/ipv4 | |
| parent | a855a814d601a4c30f26743ef1bf016df956e042 (diff) | |
Do not perform IGMP/MLD on loopback interfaces
The loopback interface will never have any neighbouring nodes so
advertising its interest in multicast groups is unnecessary.
Bug #4682, #4861
Startblock:
has LGTM from asfez
and then
add reviewer tamird
PiperOrigin-RevId: 346587604
Diffstat (limited to 'pkg/tcpip/network/ipv4')
| -rw-r--r-- | pkg/tcpip/network/ipv4/igmp.go | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/pkg/tcpip/network/ipv4/igmp.go b/pkg/tcpip/network/ipv4/igmp.go index 2ee4c6445..a3a7176a0 100644 --- a/pkg/tcpip/network/ipv4/igmp.go +++ b/pkg/tcpip/network/ipv4/igmp.go @@ -57,6 +57,9 @@ type IGMPOptions struct { // When enabled, IGMP may transmit IGMP report and leave messages when // joining and leaving multicast groups respectively, and handle incoming // IGMP packets. + // + // This field is ignored and is always assumed to be false for interfaces + // without neighbouring nodes (e.g. loopback). Enabled bool } @@ -69,6 +72,8 @@ type igmpState struct { // The IPv4 endpoint this igmpState is for. ep *endpoint + enabled bool + genericMulticastProtocol ip.GenericMulticastProtocolState // igmpV1Present is for maintaining compatibility with IGMPv1 Routers, from @@ -117,8 +122,11 @@ func (igmp *igmpState) SendLeave(groupAddress tcpip.Address) *tcpip.Error { // Must only be called once for the lifetime of igmp. func (igmp *igmpState) init(ep *endpoint) { igmp.ep = ep + // No need to perform IGMP on loopback interfaces since they don't have + // neighbouring nodes. + igmp.enabled = ep.protocol.options.IGMP.Enabled && !igmp.ep.nic.IsLoopback() igmp.genericMulticastProtocol.Init(&ep.mu.RWMutex, ip.GenericMulticastProtocolOptions{ - Enabled: ep.protocol.options.IGMP.Enabled, + Enabled: igmp.enabled, Rand: ep.protocol.stack.Rand(), Clock: ep.protocol.stack.Clock(), Protocol: igmp, @@ -210,7 +218,7 @@ func (igmp *igmpState) handleMembershipQuery(groupAddress tcpip.Address, maxResp // As per RFC 2236 Section 6, Page 10: If the maximum response time is zero // then change the state to note that an IGMPv1 router is present and // schedule the query received Job. - if maxRespTime == 0 && igmp.ep.protocol.options.IGMP.Enabled { + if igmp.enabled && maxRespTime == 0 { igmp.igmpV1Job.Cancel() igmp.igmpV1Job.Schedule(v1RouterPresentTimeout) igmp.setV1Present(true) |