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-rw-r--r--pkg/tcpip/header/ipv6.go38
-rw-r--r--pkg/tcpip/header/ipv6_test.go44
-rw-r--r--pkg/tcpip/network/ipv6/ipv6.go135
-rw-r--r--pkg/tcpip/stack/stack_test.go164
-rw-r--r--pkg/tcpip/tcpip.go38
-rw-r--r--pkg/tcpip/tcpip_test.go40
6 files changed, 340 insertions, 119 deletions
diff --git a/pkg/tcpip/header/ipv6.go b/pkg/tcpip/header/ipv6.go
index d522e5f10..5580d6a78 100644
--- a/pkg/tcpip/header/ipv6.go
+++ b/pkg/tcpip/header/ipv6.go
@@ -18,7 +18,6 @@ import (
"crypto/sha256"
"encoding/binary"
"fmt"
- "strings"
"gvisor.dev/gvisor/pkg/tcpip"
)
@@ -153,13 +152,17 @@ const (
// IPv6EmptySubnet is the empty IPv6 subnet. It may also be known as the
// catch-all or wildcard subnet. That is, all IPv6 addresses are considered to
// be contained within this subnet.
-var IPv6EmptySubnet = func() tcpip.Subnet {
- subnet, err := tcpip.NewSubnet(IPv6Any, tcpip.AddressMask(IPv6Any))
- if err != nil {
- panic(err)
- }
- return subnet
-}()
+var IPv6EmptySubnet = tcpip.AddressWithPrefix{
+ Address: IPv6Any,
+ PrefixLen: 0,
+}.Subnet()
+
+// IPv4MappedIPv6Subnet is the prefix for an IPv4 mapped IPv6 address as defined
+// by RFC 4291 section 2.5.5.
+var IPv4MappedIPv6Subnet = tcpip.AddressWithPrefix{
+ Address: "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\x00\x00\x00\x00",
+ PrefixLen: 96,
+}.Subnet()
// IPv6LinkLocalPrefix is the prefix for IPv6 link-local addresses, as defined
// by RFC 4291 section 2.5.6.
@@ -293,7 +296,7 @@ func IsV4MappedAddress(addr tcpip.Address) bool {
return false
}
- return strings.HasPrefix(string(addr), "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff")
+ return IPv4MappedIPv6Subnet.Contains(addr)
}
// IsV6MulticastAddress determines if the provided address is an IPv6
@@ -399,17 +402,6 @@ func IsV6LinkLocalMulticastAddress(addr tcpip.Address) bool {
return IsV6MulticastAddress(addr) && addr[ipv6MulticastAddressScopeByteIdx]&ipv6MulticastAddressScopeMask == ipv6LinkLocalMulticastScope
}
-// IsV6UniqueLocalAddress determines if the provided address is an IPv6
-// unique-local address (within the prefix FC00::/7).
-func IsV6UniqueLocalAddress(addr tcpip.Address) bool {
- if len(addr) != IPv6AddressSize {
- return false
- }
- // According to RFC 4193 section 3.1, a unique local address has the prefix
- // FC00::/7.
- return (addr[0] & 0xfe) == 0xfc
-}
-
// AppendOpaqueInterfaceIdentifier appends a 64 bit opaque interface identifier
// (IID) to buf as outlined by RFC 7217 and returns the extended buffer.
//
@@ -456,9 +448,6 @@ const (
// LinkLocalScope indicates a link-local address.
LinkLocalScope IPv6AddressScope = iota
- // UniqueLocalScope indicates a unique-local address.
- UniqueLocalScope
-
// GlobalScope indicates a global address.
GlobalScope
)
@@ -476,9 +465,6 @@ func ScopeForIPv6Address(addr tcpip.Address) (IPv6AddressScope, *tcpip.Error) {
case IsV6LinkLocalAddress(addr):
return LinkLocalScope, nil
- case IsV6UniqueLocalAddress(addr):
- return UniqueLocalScope, nil
-
default:
return GlobalScope, nil
}
diff --git a/pkg/tcpip/header/ipv6_test.go b/pkg/tcpip/header/ipv6_test.go
index 426a873b1..e3fbd64f3 100644
--- a/pkg/tcpip/header/ipv6_test.go
+++ b/pkg/tcpip/header/ipv6_test.go
@@ -215,48 +215,6 @@ func TestLinkLocalAddrWithOpaqueIID(t *testing.T) {
}
}
-func TestIsV6UniqueLocalAddress(t *testing.T) {
- tests := []struct {
- name string
- addr tcpip.Address
- expected bool
- }{
- {
- name: "Valid Unique 1",
- addr: uniqueLocalAddr1,
- expected: true,
- },
- {
- name: "Valid Unique 2",
- addr: uniqueLocalAddr1,
- expected: true,
- },
- {
- name: "Link Local",
- addr: linkLocalAddr,
- expected: false,
- },
- {
- name: "Global",
- addr: globalAddr,
- expected: false,
- },
- {
- name: "IPv4",
- addr: "\x01\x02\x03\x04",
- expected: false,
- },
- }
-
- for _, test := range tests {
- t.Run(test.name, func(t *testing.T) {
- if got := header.IsV6UniqueLocalAddress(test.addr); got != test.expected {
- t.Errorf("got header.IsV6UniqueLocalAddress(%s) = %t, want = %t", test.addr, got, test.expected)
- }
- })
- }
-}
-
func TestIsV6LinkLocalMulticastAddress(t *testing.T) {
tests := []struct {
name string
@@ -346,7 +304,7 @@ func TestScopeForIPv6Address(t *testing.T) {
{
name: "Unique Local",
addr: uniqueLocalAddr1,
- scope: header.UniqueLocalScope,
+ scope: header.GlobalScope,
err: nil,
},
{
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/stack/stack_test.go b/pkg/tcpip/stack/stack_test.go
index 457990945..68dcd9e61 100644
--- a/pkg/tcpip/stack/stack_test.go
+++ b/pkg/tcpip/stack/stack_test.go
@@ -2726,8 +2726,16 @@ func TestIPv6SourceAddressSelectionScopeAndSameAddress(t *testing.T) {
uniqueLocalAddr2 = tcpip.Address("\xfd\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02")
globalAddr1 = tcpip.Address("\xa0\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01")
globalAddr2 = tcpip.Address("\xa0\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02")
- nicID = 1
- lifetimeSeconds = 9999
+ globalAddr3 = tcpip.Address("\xa0\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x03")
+ ipv4MappedIPv6Addr1 = tcpip.Address("\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\x00\x00\x00\x01")
+ ipv4MappedIPv6Addr2 = tcpip.Address("\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\x00\x00\x00\x02")
+ toredoAddr1 = tcpip.Address("\x20\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01")
+ toredoAddr2 = tcpip.Address("\x20\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02")
+ ipv6ToIPv4Addr1 = tcpip.Address("\x20\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01")
+ ipv6ToIPv4Addr2 = tcpip.Address("\x20\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02")
+
+ nicID = 1
+ lifetimeSeconds = 9999
)
prefix1, _, stableGlobalAddr1 := prefixSubnetAddr(0, linkAddr1)
@@ -2744,139 +2752,191 @@ func TestIPv6SourceAddressSelectionScopeAndSameAddress(t *testing.T) {
slaacPrefixForTempAddrBeforeNICAddrAdd tcpip.AddressWithPrefix
nicAddrs []tcpip.Address
slaacPrefixForTempAddrAfterNICAddrAdd tcpip.AddressWithPrefix
- connectAddr tcpip.Address
+ remoteAddr tcpip.Address
expectedLocalAddr tcpip.Address
}{
- // Test Rule 1 of RFC 6724 section 5.
+ // Test Rule 1 of RFC 6724 section 5 (prefer same address).
{
name: "Same Global most preferred (last address)",
- nicAddrs: []tcpip.Address{linkLocalAddr1, uniqueLocalAddr1, globalAddr1},
- connectAddr: globalAddr1,
+ nicAddrs: []tcpip.Address{linkLocalAddr1, globalAddr1},
+ remoteAddr: globalAddr1,
expectedLocalAddr: globalAddr1,
},
{
name: "Same Global most preferred (first address)",
- nicAddrs: []tcpip.Address{globalAddr1, linkLocalAddr1, uniqueLocalAddr1},
- connectAddr: globalAddr1,
+ nicAddrs: []tcpip.Address{globalAddr1, uniqueLocalAddr1},
+ remoteAddr: globalAddr1,
expectedLocalAddr: globalAddr1,
},
{
name: "Same Link Local most preferred (last address)",
- nicAddrs: []tcpip.Address{globalAddr1, uniqueLocalAddr1, linkLocalAddr1},
- connectAddr: linkLocalAddr1,
+ nicAddrs: []tcpip.Address{globalAddr1, linkLocalAddr1},
+ remoteAddr: linkLocalAddr1,
expectedLocalAddr: linkLocalAddr1,
},
{
name: "Same Link Local most preferred (first address)",
- nicAddrs: []tcpip.Address{linkLocalAddr1, uniqueLocalAddr1, globalAddr1},
- connectAddr: linkLocalAddr1,
+ nicAddrs: []tcpip.Address{linkLocalAddr1, globalAddr1},
+ remoteAddr: linkLocalAddr1,
expectedLocalAddr: linkLocalAddr1,
},
{
name: "Same Unique Local most preferred (last address)",
- nicAddrs: []tcpip.Address{uniqueLocalAddr1, globalAddr1, linkLocalAddr1},
- connectAddr: uniqueLocalAddr1,
+ nicAddrs: []tcpip.Address{uniqueLocalAddr1, globalAddr1},
+ remoteAddr: uniqueLocalAddr1,
expectedLocalAddr: uniqueLocalAddr1,
},
{
name: "Same Unique Local most preferred (first address)",
- nicAddrs: []tcpip.Address{globalAddr1, linkLocalAddr1, uniqueLocalAddr1},
- connectAddr: uniqueLocalAddr1,
+ nicAddrs: []tcpip.Address{globalAddr1, uniqueLocalAddr1},
+ remoteAddr: uniqueLocalAddr1,
expectedLocalAddr: uniqueLocalAddr1,
},
- // Test Rule 2 of RFC 6724 section 5.
+ // Test Rule 2 of RFC 6724 section 5 (prefer appropriate scope).
{
name: "Global most preferred (last address)",
- nicAddrs: []tcpip.Address{linkLocalAddr1, uniqueLocalAddr1, globalAddr1},
- connectAddr: globalAddr2,
+ nicAddrs: []tcpip.Address{linkLocalAddr1, globalAddr1},
+ remoteAddr: globalAddr2,
expectedLocalAddr: globalAddr1,
},
{
name: "Global most preferred (first address)",
- nicAddrs: []tcpip.Address{globalAddr1, linkLocalAddr1, uniqueLocalAddr1},
- connectAddr: globalAddr2,
+ nicAddrs: []tcpip.Address{globalAddr1, linkLocalAddr1},
+ remoteAddr: globalAddr2,
expectedLocalAddr: globalAddr1,
},
{
name: "Link Local most preferred (last address)",
- nicAddrs: []tcpip.Address{globalAddr1, uniqueLocalAddr1, linkLocalAddr1},
- connectAddr: linkLocalAddr2,
+ nicAddrs: []tcpip.Address{globalAddr1, linkLocalAddr1},
+ remoteAddr: linkLocalAddr2,
expectedLocalAddr: linkLocalAddr1,
},
{
name: "Link Local most preferred (first address)",
- nicAddrs: []tcpip.Address{linkLocalAddr1, uniqueLocalAddr1, globalAddr1},
- connectAddr: linkLocalAddr2,
+ nicAddrs: []tcpip.Address{linkLocalAddr1, globalAddr1},
+ remoteAddr: linkLocalAddr2,
expectedLocalAddr: linkLocalAddr1,
},
{
name: "Link Local most preferred for link local multicast (last address)",
- nicAddrs: []tcpip.Address{globalAddr1, uniqueLocalAddr1, linkLocalAddr1},
- connectAddr: linkLocalMulticastAddr,
+ nicAddrs: []tcpip.Address{globalAddr1, linkLocalAddr1},
+ remoteAddr: linkLocalMulticastAddr,
expectedLocalAddr: linkLocalAddr1,
},
{
name: "Link Local most preferred for link local multicast (first address)",
- nicAddrs: []tcpip.Address{linkLocalAddr1, uniqueLocalAddr1, globalAddr1},
- connectAddr: linkLocalMulticastAddr,
+ nicAddrs: []tcpip.Address{linkLocalAddr1, globalAddr1},
+ remoteAddr: linkLocalMulticastAddr,
expectedLocalAddr: linkLocalAddr1,
},
+
+ // Test Rule 6 of 6724 section 5 (prefer matching label).
{
name: "Unique Local most preferred (last address)",
- nicAddrs: []tcpip.Address{uniqueLocalAddr1, globalAddr1, linkLocalAddr1},
- connectAddr: uniqueLocalAddr2,
+ nicAddrs: []tcpip.Address{uniqueLocalAddr1, globalAddr1, ipv4MappedIPv6Addr1, toredoAddr1, ipv6ToIPv4Addr1},
+ remoteAddr: uniqueLocalAddr2,
expectedLocalAddr: uniqueLocalAddr1,
},
{
name: "Unique Local most preferred (first address)",
- nicAddrs: []tcpip.Address{globalAddr1, linkLocalAddr1, uniqueLocalAddr1},
- connectAddr: uniqueLocalAddr2,
+ nicAddrs: []tcpip.Address{globalAddr1, ipv4MappedIPv6Addr1, toredoAddr1, ipv6ToIPv4Addr1, uniqueLocalAddr1},
+ remoteAddr: uniqueLocalAddr2,
expectedLocalAddr: uniqueLocalAddr1,
},
+ {
+ name: "Toredo most preferred (first address)",
+ nicAddrs: []tcpip.Address{toredoAddr1, uniqueLocalAddr1, globalAddr1, ipv4MappedIPv6Addr1, ipv6ToIPv4Addr1},
+ remoteAddr: toredoAddr2,
+ expectedLocalAddr: toredoAddr1,
+ },
+ {
+ name: "Toredo most preferred (last address)",
+ nicAddrs: []tcpip.Address{globalAddr1, ipv4MappedIPv6Addr1, ipv6ToIPv4Addr1, uniqueLocalAddr1, toredoAddr1},
+ remoteAddr: toredoAddr2,
+ expectedLocalAddr: toredoAddr1,
+ },
+ {
+ name: "6To4 most preferred (first address)",
+ nicAddrs: []tcpip.Address{ipv6ToIPv4Addr1, toredoAddr1, uniqueLocalAddr1, globalAddr1, ipv4MappedIPv6Addr1},
+ remoteAddr: ipv6ToIPv4Addr2,
+ expectedLocalAddr: ipv6ToIPv4Addr1,
+ },
+ {
+ name: "6To4 most preferred (last address)",
+ nicAddrs: []tcpip.Address{globalAddr1, ipv4MappedIPv6Addr1, uniqueLocalAddr1, toredoAddr1, ipv6ToIPv4Addr1},
+ remoteAddr: ipv6ToIPv4Addr2,
+ expectedLocalAddr: ipv6ToIPv4Addr1,
+ },
+ {
+ name: "IPv4 mapped IPv6 most preferred (first address)",
+ nicAddrs: []tcpip.Address{ipv4MappedIPv6Addr1, ipv6ToIPv4Addr1, toredoAddr1, uniqueLocalAddr1, globalAddr1},
+ remoteAddr: ipv4MappedIPv6Addr2,
+ expectedLocalAddr: ipv4MappedIPv6Addr1,
+ },
+ {
+ name: "IPv4 mapped IPv6 most preferred (last address)",
+ nicAddrs: []tcpip.Address{globalAddr1, ipv6ToIPv4Addr1, uniqueLocalAddr1, toredoAddr1, ipv4MappedIPv6Addr1},
+ remoteAddr: ipv4MappedIPv6Addr2,
+ expectedLocalAddr: ipv4MappedIPv6Addr1,
+ },
- // Test Rule 7 of RFC 6724 section 5.
+ // Test Rule 7 of RFC 6724 section 5 (prefer temporary addresses).
{
name: "Temp Global most preferred (last address)",
slaacPrefixForTempAddrBeforeNICAddrAdd: prefix1,
nicAddrs: []tcpip.Address{linkLocalAddr1, uniqueLocalAddr1, globalAddr1},
- connectAddr: globalAddr2,
+ remoteAddr: globalAddr2,
expectedLocalAddr: tempGlobalAddr1,
},
{
name: "Temp Global most preferred (first address)",
nicAddrs: []tcpip.Address{linkLocalAddr1, uniqueLocalAddr1, globalAddr1},
slaacPrefixForTempAddrAfterNICAddrAdd: prefix1,
- connectAddr: globalAddr2,
+ remoteAddr: globalAddr2,
expectedLocalAddr: tempGlobalAddr1,
},
+ // Test Rule 8 of RFC 6724 section 5 (use longest matching prefix).
+ {
+ name: "Longest prefix matched most preferred (first address)",
+ nicAddrs: []tcpip.Address{globalAddr2, globalAddr1},
+ remoteAddr: globalAddr3,
+ expectedLocalAddr: globalAddr2,
+ },
+ {
+ name: "Longest prefix matched most preferred (last address)",
+ nicAddrs: []tcpip.Address{globalAddr1, globalAddr2},
+ remoteAddr: globalAddr3,
+ expectedLocalAddr: globalAddr2,
+ },
+
// Test returning the endpoint that is closest to the front when
// candidate addresses are "equal" from the perspective of RFC 6724
// section 5.
{
name: "Unique Local for Global",
nicAddrs: []tcpip.Address{linkLocalAddr1, uniqueLocalAddr1, uniqueLocalAddr2},
- connectAddr: globalAddr2,
+ remoteAddr: globalAddr2,
expectedLocalAddr: uniqueLocalAddr1,
},
{
name: "Link Local for Global",
nicAddrs: []tcpip.Address{linkLocalAddr1, linkLocalAddr2},
- connectAddr: globalAddr2,
+ remoteAddr: globalAddr2,
expectedLocalAddr: linkLocalAddr1,
},
{
name: "Link Local for Unique Local",
nicAddrs: []tcpip.Address{linkLocalAddr1, linkLocalAddr2},
- connectAddr: uniqueLocalAddr2,
+ remoteAddr: uniqueLocalAddr2,
expectedLocalAddr: linkLocalAddr1,
},
{
name: "Temp Global for Global",
slaacPrefixForTempAddrBeforeNICAddrAdd: prefix1,
slaacPrefixForTempAddrAfterNICAddrAdd: prefix2,
- connectAddr: globalAddr1,
+ remoteAddr: globalAddr1,
expectedLocalAddr: tempGlobalAddr2,
},
}
@@ -2898,12 +2958,6 @@ func TestIPv6SourceAddressSelectionScopeAndSameAddress(t *testing.T) {
if err := s.CreateNIC(nicID, e); err != nil {
t.Fatalf("CreateNIC(%d, _) = %s", nicID, err)
}
- s.SetRouteTable([]tcpip.Route{{
- Destination: header.IPv6EmptySubnet,
- Gateway: llAddr3,
- NIC: nicID,
- }})
- s.AddLinkAddress(nicID, llAddr3, linkAddr3)
if test.slaacPrefixForTempAddrBeforeNICAddrAdd != (tcpip.AddressWithPrefix{}) {
e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr3, 0, test.slaacPrefixForTempAddrBeforeNICAddrAdd, true, true, lifetimeSeconds, lifetimeSeconds))
@@ -2923,7 +2977,23 @@ func TestIPv6SourceAddressSelectionScopeAndSameAddress(t *testing.T) {
t.FailNow()
}
- if got := addrForNewConnectionTo(t, s, tcpip.FullAddress{Addr: test.connectAddr, NIC: nicID, Port: 1234}); got != test.expectedLocalAddr {
+ netEP, err := s.GetNetworkEndpoint(nicID, header.IPv6ProtocolNumber)
+ if err != nil {
+ t.Fatalf("s.GetNetworkEndpoint(%d, %d): %s", nicID, header.IPv6ProtocolNumber, err)
+ }
+
+ addressableEndpoint, ok := netEP.(stack.AddressableEndpoint)
+ if !ok {
+ t.Fatal("network endpoint is not addressable")
+ }
+
+ addressEP := addressableEndpoint.AcquireOutgoingPrimaryAddress(test.remoteAddr, false /* allowExpired */)
+ if addressEP == nil {
+ t.Fatal("expected a non-nil address endpoint")
+ }
+ defer addressEP.DecRef()
+
+ if got := addressEP.AddressWithPrefix().Address; got != test.expectedLocalAddr {
t.Errorf("got local address = %s, want = %s", got, test.expectedLocalAddr)
}
})
diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go
index a488cc108..d195304be 100644
--- a/pkg/tcpip/tcpip.go
+++ b/pkg/tcpip/tcpip.go
@@ -258,6 +258,44 @@ func (a Address) Unspecified() bool {
return true
}
+// MatchingPrefix returns the matching prefix length in bits.
+//
+// Panics if b and a have different lengths.
+func (a Address) MatchingPrefix(b Address) uint8 {
+ const bitsInAByte = 8
+
+ if len(a) != len(b) {
+ panic(fmt.Sprintf("addresses %s and %s do not have the same length", a, b))
+ }
+
+ var prefix uint8
+ for i := range a {
+ aByte := a[i]
+ bByte := b[i]
+
+ if aByte == bByte {
+ prefix += bitsInAByte
+ continue
+ }
+
+ // Count the remaining matching bits in the byte from MSbit to LSBbit.
+ mask := uint8(1) << (bitsInAByte - 1)
+ for {
+ if aByte&mask == bByte&mask {
+ prefix++
+ mask >>= 1
+ continue
+ }
+
+ break
+ }
+
+ break
+ }
+
+ return prefix
+}
+
// AddressMask is a bitmask for an address.
type AddressMask string
diff --git a/pkg/tcpip/tcpip_test.go b/pkg/tcpip/tcpip_test.go
index c461da137..9bd563c46 100644
--- a/pkg/tcpip/tcpip_test.go
+++ b/pkg/tcpip/tcpip_test.go
@@ -270,3 +270,43 @@ func TestAddressUnspecified(t *testing.T) {
})
}
}
+
+func TestAddressMatchingPrefix(t *testing.T) {
+ tests := []struct {
+ addrA Address
+ addrB Address
+ prefix uint8
+ }{
+ {
+ addrA: "\x01\x01",
+ addrB: "\x01\x01",
+ prefix: 16,
+ },
+ {
+ addrA: "\x01\x01",
+ addrB: "\x01\x00",
+ prefix: 15,
+ },
+ {
+ addrA: "\x01\x01",
+ addrB: "\x81\x00",
+ prefix: 0,
+ },
+ {
+ addrA: "\x01\x01",
+ addrB: "\x01\x80",
+ prefix: 8,
+ },
+ {
+ addrA: "\x01\x01",
+ addrB: "\x02\x80",
+ prefix: 6,
+ },
+ }
+
+ for _, test := range tests {
+ if got := test.addrA.MatchingPrefix(test.addrB); got != test.prefix {
+ t.Errorf("got (%s).MatchingPrefix(%s) = %d, want = %d", test.addrA, test.addrB, got, test.prefix)
+ }
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-05 12:32:44 +0000