This allows the link layer endpoints to consistenly hash a TCP
segment to a single underlying queue in case a link layer endpoint
does support multiple underlying queues.
Updates #231
PiperOrigin-RevId: 302760664
This is a precursor to be being able to build an intrusive list
of PacketBuffers for use in queuing disciplines being implemented.
Updates #2214
PiperOrigin-RevId: 302677662
workMu is removed and e.mu is now a mutex that supports TryLock. The packet
processing path tries to lock the mutex and if its locked it will just queue the
packet and move on. The endpoint.UnlockUser() will process any backlog of
packets before unlocking the socket.
This simplifies the locking inside tcp endpoints a lot. Further the
endpoint.LockUser() implements spinning as long as the lock is not held by
another syscall goroutine. This ensures low latency as not spinning leads to the
task thread being put to sleep if the lock is held by the packet dispatch
path. This is suboptimal as the lower layer rarely holds the lock for long so
implementing spinning here helps.
If the lock is held by another task goroutine then we just proceed to call
LockUser() and the task could be put to sleep.
The protocol goroutines themselves just call e.mu.Lock() and block if the
lock is currently not available.
Updates #231, #357
PiperOrigin-RevId: 301808349
Previously, SLAAC related state was stored on a per-address basis. This was
sufficient for the simple case of a single SLAAC address per prefix, but
future CLs will introduce temporary addresses which will result in multiple
SLAAC addresses for a prefix. This refactor allows storing multiple addresses
for a prefix in a single SLAAC prefix state.
No behaviour changes - existing tests continue to pass.
PiperOrigin-RevId: 300832812
When a NIC is removed, attempt to disable the NIC first to cleanup
dynamic state and stop ongoing periodic tasks (e.g. IPv6 router
solicitations, DAD) so that a removed NIC does not attempt to send
packets.
Tests:
- stack_test.TestRemoveUnknownNIC
- stack_test.TestRemoveNIC
- stack_test.TestDADStop
- stack_test.TestCleanupNDPState
- stack_test.TestRouteWithDownNIC
- stack_test.TestStopStartSolicitingRouters
PiperOrigin-RevId: 300805857
- Don't allocate []*endpointsByNic in transportDemuxer.deliverPacket() unless
actually needed for UDP broadcast/multicast.
- Don't allocate []*endpointsByNic via transportDemuxer.findEndpointLocked()
=> transportDemuxer.findAllEndpointsLocked().
- Skip unnecessary map lookups in transportDemuxer.findEndpointLocked() =>
transportDemuxer.findAllEndpointsLocked() (now iterEndpointsLocked).
For most deliverable packets other than UDP broadcast/multicast packets, this
saves two slice allocations and three map lookups per packet.
PiperOrigin-RevId: 300804135
LinkEndpoints may expect/assume that the a tcpip.PacketBuffer's Header
has enough capacity for its own headers, as per documentation for
LinkEndpoint.MaxHeaderLength.
Test: stack_test.TestNICForwarding
PiperOrigin-RevId: 300784192
Endpoints which were being terminated in an ERROR state or were moved to CLOSED
by the worker goroutine do not run cleanupLocked() as that should already be run
by the worker termination. But when making that change we made the mistake of
not removing the endpoint from the danglingEndpoints which is normally done in
cleanupLocked().
As a result these endpoints are leaked since a reference is held to them in the
danglingEndpoints array forever till Stack is torn down.
PiperOrigin-RevId: 300438426
This change also updates where the IP packet buffer is held in an
outbound tcpip.PacketBuffer from Header to Data. This change removes
unncessary copying of the IP packet buffer when forwarding.
Test: stack_test.TestNICForwarding
PiperOrigin-RevId: 300217972
When list elements are removed from a list but not discarded, it becomes
important to invalidate the references they hold to their former
neighbors to prevent memory leaks.
PiperOrigin-RevId: 299412421
If the NIC has a valid IPv6 address assigned, use it as the
source address for outgoing NDP Router Solicitation packets.
Test: stack_test.TestRouterSolicitation
PiperOrigin-RevId: 299398763
By putting slices into the pool, the slice header escapes. This can be avoided
by not putting the slice header into the pool.
This removes an allocation from the TCP segment send path.
PiperOrigin-RevId: 299215480
Ensures that all access to TransportEndpointInfo.ID is either:
* In a function ending in a Locked suffix.
* While holding the appropriate mutex.
This primary affects the checkV4Mapped method on affected endpoints, which has
been renamed to checkV4MappedLocked. Also document the method and change its
argument to be a value instead of a pointer which had caused some awkwardness.
This race was possible in the udp and icmp endpoints between Connect and uses
of TransportEndpointInfo.ID including in both itself and Bind.
The tcp endpoint did not suffer from this bug, but benefited from better
documentation.
Updates #357
PiperOrigin-RevId: 298682913
A deadlock may occur if a write lock on a RWMutex is blocked between
nested read lock attempts as the inner read lock attempt will be
blocked in this scenario.
Example (T1 and T2 are differnt goroutines):
T1: obtain read-lock
T2: attempt write-lock (blocks)
T1: attempt inner/nested read-lock (blocks)
Here we can see that T1 and T2 are deadlocked.
Tests: Existing tests pass.
PiperOrigin-RevId: 298426678
Call stack.Close on stacks when we are done with them in tcp_test. This avoids
leaking resources and reduces the test's flakiness when race/gotsan is enabled.
It also provides test coverage for the race also fixed in this change, which
can be reliably triggered with the stack.Close change (and without the other
changes) when race/gotsan is enabled.
The race was possible when calling Abort (via stack.Close) on an endpoint
processing a SYN segment as part of a passive connect.
Updates #1564
PiperOrigin-RevId: 297685432
Enables commands such as:
$ iptables -A INPUT -d 127.0.0.1 -j ACCEPT
$ iptables -t nat -A PREROUTING ! -d 127.0.0.1 -j REDIRECT
Also adds a bunch of REDIRECT+destination tests.
TestCurrentConnectedIncrement fails consistently under gotsan due to the sleep
to check metrics is exactly the same as the TIME-WAIT duration. Under gotsan
things can be slow enough that the increment test is done before the protocol
goroutine is run after the TIME-WAIT timer expires and does its cleanup.
Increasing the sleep from 1s to 1.2s makes the test pass consistently.
PiperOrigin-RevId: 297160181
Protocol dispatchers were previously leaked. Bypassing TIME_WAIT is required to
test this change.
Also fix a race when a socket in SYN-RCVD is closed. This is also required to
test this change.
PiperOrigin-RevId: 296922548