summaryrefslogtreecommitdiffhomepage
path: root/pkg/tcpip/network/ipv6
diff options
context:
space:
mode:
Diffstat (limited to 'pkg/tcpip/network/ipv6')
-rw-r--r--pkg/tcpip/network/ipv6/ipv6.go135
-rw-r--r--pkg/tcpip/network/ipv6/mld.go12
2 files changed, 140 insertions, 7 deletions
diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go
index a49b5ac77..f2018d073 100644
--- a/pkg/tcpip/network/ipv6/ipv6.go
+++ b/pkg/tcpip/network/ipv6/ipv6.go
@@ -61,6 +61,108 @@ const (
buckets = 2048
)
+// policyTable is the default policy table defined in RFC 6724 section 2.1.
+//
+// A more human-readable version:
+//
+// Prefix Precedence Label
+// ::1/128 50 0
+// ::/0 40 1
+// ::ffff:0:0/96 35 4
+// 2002::/16 30 2
+// 2001::/32 5 5
+// fc00::/7 3 13
+// ::/96 1 3
+// fec0::/10 1 11
+// 3ffe::/16 1 12
+//
+// The table is sorted by prefix length so longest-prefix match can be easily
+// achieved.
+//
+// We willingly left out ::/96, fec0::/10 and 3ffe::/16 since those prefix
+// assignments are deprecated.
+//
+// As per RFC 4291 section 2.5.5.1 (for ::/96),
+//
+// The "IPv4-Compatible IPv6 address" is now deprecated because the
+// current IPv6 transition mechanisms no longer use these addresses.
+// New or updated implementations are not required to support this
+// address type.
+//
+// As per RFC 3879 section 4 (for fec0::/10),
+//
+// This document formally deprecates the IPv6 site-local unicast prefix
+// defined in [RFC3513], i.e., 1111111011 binary or FEC0::/10.
+//
+// As per RFC 3701 section 1 (for 3ffe::/16),
+//
+// As clearly stated in [TEST-NEW], the addresses for the 6bone are
+// temporary and will be reclaimed in the future. It further states
+// that all users of these addresses (within the 3FFE::/16 prefix) will
+// be required to renumber at some time in the future.
+//
+// and section 2,
+//
+// Thus after the pTLA allocation cutoff date January 1, 2004, it is
+// REQUIRED that no new 6bone 3FFE pTLAs be allocated.
+//
+// MUST NOT BE MODIFIED.
+var policyTable = [...]struct {
+ subnet tcpip.Subnet
+
+ label uint8
+}{
+ // ::1/128
+ {
+ subnet: header.IPv6Loopback.WithPrefix().Subnet(),
+ label: 0,
+ },
+ // ::ffff:0:0/96
+ {
+ subnet: header.IPv4MappedIPv6Subnet,
+ label: 4,
+ },
+ // 2001::/32 (Teredo prefix as per RFC 4380 section 2.6).
+ {
+ subnet: tcpip.AddressWithPrefix{
+ Address: "\x20\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
+ PrefixLen: 32,
+ }.Subnet(),
+ label: 5,
+ },
+ // 2002::/16 (6to4 prefix as per RFC 3056 section 2).
+ {
+ subnet: tcpip.AddressWithPrefix{
+ Address: "\x20\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
+ PrefixLen: 16,
+ }.Subnet(),
+ label: 2,
+ },
+ // fc00::/7 (Unique local addresses as per RFC 4193 section 3.1).
+ {
+ subnet: tcpip.AddressWithPrefix{
+ Address: "\xfc\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
+ PrefixLen: 7,
+ }.Subnet(),
+ label: 13,
+ },
+ // ::/0
+ {
+ subnet: header.IPv6EmptySubnet,
+ label: 1,
+ },
+}
+
+func getLabel(addr tcpip.Address) uint8 {
+ for _, p := range policyTable {
+ if p.subnet.Contains(addr) {
+ return p.label
+ }
+ }
+
+ panic(fmt.Sprintf("should have a label for address = %s", addr))
+}
+
var _ stack.GroupAddressableEndpoint = (*endpoint)(nil)
var _ stack.AddressableEndpoint = (*endpoint)(nil)
var _ stack.NetworkEndpoint = (*endpoint)(nil)
@@ -1373,7 +1475,11 @@ func (e *endpoint) acquireOutgoingPrimaryAddressRLocked(remoteAddr tcpip.Address
// RFC 6724 section 5.
type addrCandidate struct {
addressEndpoint stack.AddressEndpoint
+ addr tcpip.Address
scope header.IPv6AddressScope
+
+ label uint8
+ matchingPrefix uint8
}
if len(remoteAddr) == 0 {
@@ -1400,7 +1506,10 @@ func (e *endpoint) acquireOutgoingPrimaryAddressRLocked(remoteAddr tcpip.Address
cs = append(cs, addrCandidate{
addressEndpoint: addressEndpoint,
+ addr: addr,
scope: scope,
+ label: getLabel(addr),
+ matchingPrefix: remoteAddr.MatchingPrefix(addr),
})
return true
@@ -1412,18 +1521,20 @@ func (e *endpoint) acquireOutgoingPrimaryAddressRLocked(remoteAddr tcpip.Address
panic(fmt.Sprintf("header.ScopeForIPv6Address(%s): %s", remoteAddr, err))
}
+ remoteLabel := getLabel(remoteAddr)
+
// Sort the addresses as per RFC 6724 section 5 rules 1-3.
//
- // TODO(b/146021396): Implement rules 4-8 of RFC 6724 section 5.
+ // TODO(b/146021396): Implement rules 4, 5 of RFC 6724 section 5.
sort.Slice(cs, func(i, j int) bool {
sa := cs[i]
sb := cs[j]
// Prefer same address as per RFC 6724 section 5 rule 1.
- if sa.addressEndpoint.AddressWithPrefix().Address == remoteAddr {
+ if sa.addr == remoteAddr {
return true
}
- if sb.addressEndpoint.AddressWithPrefix().Address == remoteAddr {
+ if sb.addr == remoteAddr {
return false
}
@@ -1440,11 +1551,29 @@ func (e *endpoint) acquireOutgoingPrimaryAddressRLocked(remoteAddr tcpip.Address
return sbDep
}
+ // Prefer matching label as per RFC 6724 section 5 rule 6.
+ if sa, sb := sa.label == remoteLabel, sb.label == remoteLabel; sa != sb {
+ if sa {
+ return true
+ }
+ if sb {
+ return false
+ }
+ }
+
// Prefer temporary addresses as per RFC 6724 section 5 rule 7.
if saTemp, sbTemp := sa.addressEndpoint.ConfigType() == stack.AddressConfigSlaacTemp, sb.addressEndpoint.ConfigType() == stack.AddressConfigSlaacTemp; saTemp != sbTemp {
return saTemp
}
+ // Use longest matching prefix as per RFC 6724 section 5 rule 8.
+ if sa.matchingPrefix > sb.matchingPrefix {
+ return true
+ }
+ if sb.matchingPrefix > sa.matchingPrefix {
+ return false
+ }
+
// sa and sb are equal, return the endpoint that is closest to the front of
// the primary endpoint list.
return i < j
diff --git a/pkg/tcpip/network/ipv6/mld.go b/pkg/tcpip/network/ipv6/mld.go
index 6f64b8462..e8d1e7a79 100644
--- a/pkg/tcpip/network/ipv6/mld.go
+++ b/pkg/tcpip/network/ipv6/mld.go
@@ -58,6 +58,13 @@ type mldState struct {
genericMulticastProtocol ip.GenericMulticastProtocolState
}
+// Enabled implements ip.MulticastGroupProtocol.
+func (mld *mldState) Enabled() bool {
+ // No need to perform MLD on loopback interfaces since they don't have
+ // neighbouring nodes.
+ return mld.ep.protocol.options.MLD.Enabled && !mld.ep.nic.IsLoopback() && mld.ep.Enabled()
+}
+
// SendReport implements ip.MulticastGroupProtocol.
//
// Precondition: mld.ep.mu must be read locked.
@@ -80,9 +87,6 @@ func (mld *mldState) SendLeave(groupAddress tcpip.Address) *tcpip.Error {
func (mld *mldState) init(ep *endpoint) {
mld.ep = ep
mld.genericMulticastProtocol.Init(&ep.mu.RWMutex, ip.GenericMulticastProtocolOptions{
- // No need to perform MLD on loopback interfaces since they don't have
- // neighbouring nodes.
- Enabled: ep.protocol.options.MLD.Enabled && !mld.ep.nic.IsLoopback(),
Rand: ep.protocol.stack.Rand(),
Clock: ep.protocol.stack.Clock(),
Protocol: mld,
@@ -112,7 +116,7 @@ func (mld *mldState) handleMulticastListenerReport(mldHdr header.MLD) {
//
// Precondition: mld.ep.mu must be locked.
func (mld *mldState) joinGroup(groupAddress tcpip.Address) {
- mld.genericMulticastProtocol.JoinGroupLocked(groupAddress, !mld.ep.Enabled() /* dontInitialize */)
+ mld.genericMulticastProtocol.JoinGroupLocked(groupAddress)
}
// isInGroup returns true if the specified group has been joined locally.
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-07 20:47:15 +0000