Because the code handles a bad header as "payload" right up to the last moment
we need to make sure payload handling does not remove the error information.
Fixes#4909
PiperOrigin-RevId: 344141690
The IGMPv2 core state machine can be shared with MLDv1 since they are
almost identical, ignoring specific addresses, constants and packets.
Bug #4682, #4861
PiperOrigin-RevId: 344102615
Added headers, stats, checksum parsing capabilities from RFC 2236 describing
IGMPv2.
IGMPv2 state machine is implemented for each condition, sending and receiving
IGMP Membership Reports and Leave Group messages with backwards compatibility
with IGMPv1 routers.
Test:
* Implemented igmp header parser and checksum calculator in header/igmp_test.go
* ipv4/igmp_test.go tests incoming and outgoing IGMP messages and pathways.
* Added unit test coverage for IGMPv2 RFC behavior + IGMPv1 backwards
compatibility in ipv4/igmp_test.go.
Fixes#4682
PiperOrigin-RevId: 343408809
Group addressable endpoints can simply check if it has joined the
multicast group without maintaining address endpoints. This also
helps remove the dependency on AddressableEndpoint from
GroupAddressableEndpoint.
Now that group addresses are not tracked with address endpoints, we can
avoid accidentally obtaining a route with a multicast local address.
PiperOrigin-RevId: 343336912
- Make AddressableEndpoint optional for NetworkEndpoint.
Not all NetworkEndpoints need to support addressing (e.g. ARP), so
AddressableEndpoint should only be implemented for protocols that
support addressing such as IPv4 and IPv6.
With this change, tcpip.ErrNotSupported will be returned by the stack
when attempting to modify addresses on a network endpoint that does
not support addressing.
Now that packets are fully handled at the network layer, and (with this
change) addresses are optional for network endpoints, we no longer need
the workaround for ARP where a fake ARP address was added to each NIC
that performs ARP so that packets would be delivered to the ARP layer.
PiperOrigin-RevId: 342722547
- Pass a PacketBuffer directly instead of releaseCB
- No longer pass a VectorisedView, which is included in the PacketBuffer
- Make it an error if data size is not equal to (last - first + 1)
- Set the callback for the reassembly timeout on NewFragmentation
PiperOrigin-RevId: 342702432
If the packet must no longer be forwarded because its TTL/Hop Limit
reaches 0, send an ICMP Time Exceeded error to the source.
Required as per relevant RFCs. See comments in code for RFC references.
Fixes#1085
Tests:
- ipv4_test.TestForwarding
- ipv6.TestForwarding
PiperOrigin-RevId: 342323610
The NIC should not hold network-layer state or logic - network packet
handling/forwarding should be performed at the network layer instead
of the NIC.
Fixes#4688
PiperOrigin-RevId: 342166985
Most packets don't have options but they are an integral part of the
standard. Teaching the ipv4 code how to handle them will simplify future
testing and use. Because Options are so rare it is worth making sure
that the extra work is kept out of the fast path as much as possible.
Prior to this change, all usages of the IHL field of the IPv4Fields/Encode
system set it to the same constant value except in a couple of tests
for bad values. From this change IHL will not be a constant as it will
depend on the size of any Options. Since ipv4.Encode() now handles the
options it becomes a possible source of errors to let the callers set
this value, so remove it entirely and calculate the value from the size
of the Options if present (or not) therefore guaranteeing a correct value.
Fixes#4709
RELNOTES: n/a
PiperOrigin-RevId: 341864765
This change adds a Subnet() method to AddressableEndpoint so that we
can avoid repeated calls to AddressableEndpoint.AddressWithPrefix().Subnet().
Updates #231
PiperOrigin-RevId: 340969877
* Remove stack.Route from incoming packet path.
There is no need to pass around a stack.Route during the incoming path
of a packet. Instead, pass around the packet's link/network layer
information in the packet buffer since all layers may need this
information.
* Support address bound and outgoing packet NIC in routes.
When forwarding is enabled, the source address of a packet may be bound
to a different interface than the outgoing interface. This change
updates stack.Route to hold both NICs so that one can be used to write
packets while the other is used to check if the route's bound address
is valid. Note, we need to hold the address's interface so we can check
if the address is a spoofed address.
* Introduce the concept of a local route.
Local routes are routes where the packet never needs to leave the stack;
the destination is stack-local. We can now route between interfaces
within a stack if the packet never needs to leave the stack, even when
forwarding is disabled.
* Always obtain a route from the stack before sending a packet.
If a packet needs to be sent in response to an incoming packet, a route
must be obtained from the stack to ensure the stack is configured to
send packets to the packet's source from the packet's destination.
* Enable spoofing if a stack may send packets from unowned addresses.
This change required changes to some netgophers since previously,
promiscuous mode was enough to let the netstack respond to all
incoming packets regardless of the packet's destination address. Now
that a stack.Route is not held for each incoming packet, finding a route
may fail with local addresses we don't own but accepted packets for
while in promiscuous mode. Since we also want to be able to send from
any address (in response the received promiscuous mode packets), we need
to enable spoofing.
* Skip transport layer checksum checks for locally generated packets.
If a packet is locally generated, the stack can safely assume that no
errors were introduced while being locally routed since the packet is
never sent out the wire.
Some bugs fixed:
- transport layer checksum was never calculated after NAT.
- handleLocal didn't handle routing across interfaces.
- stack didn't support forwarding across interfaces.
- always consult the routing table before creating an endpoint.
Updates #4688Fixes#3906
PiperOrigin-RevId: 340943442
IPv4 options extend the size of the IP header and have a basic known
format. The framework can process that format without needing to know
about every possible option. We can add more code to handle additional
option types as we need them. Bad options or mangled option entries
can result in ICMP Parameter Problem packets. The first types we
support are the Timestamp option and the Record Route option, included
in this change.
The options are processed at several points in the packet flow within
the Network stack, with slightly different requirements. The framework
includes a mechanism to control this at each point. Support has been
added for such points which are only present in upcoming CLs such as
during packet forwarding and fragmentation.
With this change, 'ping -R' and 'ping -T' work against gVisor and Fuchsia.
$ ping -R 192.168.1.2
PING 192.168.1.2 (192.168.1.2) 56(124) bytes of data.
64 bytes from 192.168.1.2: icmp_seq=1 ttl=64 time=0.990 ms
NOP
RR: 192.168.1.1
192.168.1.2
192.168.1.1
$ ping -T tsprespec 192.168.1.2 192.168.1.1 192.168.1.2
PING 192.168.1.2 (192.168.1.2) 56(124) bytes of data.
64 bytes from 192.168.1.2: icmp_seq=1 ttl=64 time=1.20 ms
TS: 192.168.1.2 71486821 absolute
192.168.1.1 746
Unit tests included for generic options, Timestamp options
and Record Route options.
PiperOrigin-RevId: 339379076
Previously, the NIC local address used when completing link resolution
was held in the neighbor entry. A neighbor is not identified by any
NIC local address so remove it.
PiperOrigin-RevId: 338699695
Previously a link endpoint was passed to
stack.LinkAddressResolver.LinkAddressRequest. With this change,
implementations that want a route for the link address request may
find one through the stack. Other implementations that want to send
a packet without a route may continue to do so using the network
interface directly.
Test: - arp_test.TestLinkAddressRequest
- ipv6.TestLinkAddressRequest
PiperOrigin-RevId: 338577474
The IPv4 header checksum has not been checked, at least in recent times,
so add code to do so. Fix all the tests that fail because they never
needed to set the checksum.
Fixes#4484
PiperOrigin-RevId: 337556243
Currently, fragmentation can only occur during WritePacket(). This enables
it for WritePackets() and WriteIncludedHeaderPacket() as well.
IPv4 unit tests were refactored to be consistent with the IPv6 unit tests.
This removes the extraHeaderReserveLength field and the related
"prependable bytes" unit tests (for both IPv4 and IPv6) because it was only
testing a panic condition when the value was too low.
Fixes#3796
PiperOrigin-RevId: 337550061
Allow writing an IPv6 packet where the IPv6 header is a provided by
the user.
* Introduce an error to let callers know a header is malformed.
We previously useed tcpip.ErrInvalidOptionValue but that did not seem
appropriate for generic malformed header errors.
* Populate network header in WriteHeaderIncludedPacket
IPv4's implementation of WriteHeaderIncludedPacket did not previously
populate the packet buffer's network header. This change fixes that.
Fixes#4527
Test: ip_test.TestWriteHeaderIncludedPacket
PiperOrigin-RevId: 337534548
RFC 4861 section 4.4 comments the Target link-layer address option is sometimes
optional in a Neighbor Advertisement packet:
"When responding to a unicast Neighbor Solicitation this option SHOULD be
included."
Tests:
pkg/tcpip/stack:stack_test
- TestEntryStaleToReachableWhenSolicitedConfirmationWithoutAddress
- TestEntryDelayToReachableWhenSolicitedConfirmationWithoutAddress
- TestEntryProbeToReachableWhenSolicitedConfirmationWithoutAddress
pkg/tcpip/network/ipv6:ipv6_test
- TestCallsToNeighborCache
PiperOrigin-RevId: 337396493
Test helpers should be used for test setup/teardown, not actual
testing. Use cmp.Diff instead of bytes.Equal to improve readability.
PiperOrigin-RevId: 337323242
This change also brings back the stack.Route.ResolveWith method so that
we can immediately resolve a route when sending an NA in response to a
a NS with a source link layer address option.
Test: ipv6_test.TestNeighorSolicitationResponse
PiperOrigin-RevId: 337185461
When a response needs to be sent to an incoming packet, the stack should
consult its neighbour table to determine the remote address's link
address.
When an entry does not exist in the stack's neighbor table, the stack
should queue the packet while link resolution completes. See comments.
PiperOrigin-RevId: 336185457
When the neighbor table already has link address for a neighbor but is
trying to confirm reachability, it may send unicast probes to the
neighbor.
PiperOrigin-RevId: 336166711
It was originally set to 30s for IPv6 (same as IPv4) but this is not
what RFC 8200 prescibes. Linux also defaults to 60s [1].
[1] 47ec5303d7/include/net/ipv6.h (L456)
PiperOrigin-RevId: 336034636
Most of the IPv4 fragmentation code was moved in the fragmentation
package and it is reused by IPv6 fragmentation.
Test:
- pkg/tcpip/network/ipv4:ipv4_test
- pkg/tcpip/network/ipv6:ipv6_test
- pkg/tcpip/network/fragmentation:fragmentation_test
Fixes#4389
PiperOrigin-RevId: 335714280
The IPv4 RFCs are specific (though obtuse) that an echo response
packet needs to contain all the options from the echo request,
much as if it been routed back to the sender, though apparently
with a new TTL. They suggest copying the incoming packet header
to achieve this so that is what this patch does.
PiperOrigin-RevId: 335559176
Before this change, OutgoingPacketErrors was incremented in the
stack.Route methods. This was going to be a problem once
IPv4/IPv6 WritePackets support fragmentation because Route.WritePackets
might now know how many packets are left after an error occurs.
Test:
- pkg/tcpip/network/ipv4:ipv4_test
- pkg/tcpip/network/ipv6:ipv6_test
PiperOrigin-RevId: 334687983
Add code in IPv6 to send ICMP packets while processing extension headers.
Add some accounting in processing IPV6 Extension headers which
allows us to report meaningful information back in ICMP parameter
problem packets.
IPv4 also needs to send a message when an unsupported protocol
is requested.
Add some tests to generate both ipv4 and ipv6 packets with
various errors and check the responses.
Add some new checkers and cleanup some inconsistencies in
the messages in that file.
Add new error types for the ICMPv4/6 generators.
Fix a bug in the ICMPv4 generator that stopped it from generating
"Unknown protocol" messages.
Updates #2211
PiperOrigin-RevId: 334661716
As per relevant IP RFCS (see code comments), broadcast (for IPv4) and
multicast addresses are not allowed. Currently checks for these are
done at the transport layer, but since it is explicitly forbidden at
the IP layers, check for them there.
This change also removes the UDP.InvalidSourceAddress stat since there
is no longer a need for it.
Test: ip_test.TestSourceAddressValidation
PiperOrigin-RevId: 334490971
Like matchers, targets should use a module-like register/lookup system. This
replaces the brittle switch statements we had before.
The only behavior change is supporing IPT_GET_REVISION_TARGET. This makes it
much easier to add IPv6 redirect in the next change.
Updates #3549.
PiperOrigin-RevId: 334469418
Linux doesn't generate a link-local address for the loopback interface.
Test: integration_test.TestInitialLoopbackAddresses
PiperOrigin-RevId: 334453182
Currently expired IP fragments are discarded only if another fragment for the
same IP datagram is received after timeout or the total size of the fragment
queue exceeded a predefined value.
Test: fragmentation.TestReassemblingTimeout
Fixes#3960
PiperOrigin-RevId: 334423710
Julian Elischer
Ghanan Gowripalan
Ryan Heacock
Ting-Yu Wang
Bruno Dal Bo
Toshi Kikuchi
Bhasker Hariharan
Kevin Krakauer
Tamir Duberstein
Arthur Sfez
Sam Balana
Peter Johnston