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2020-10-23Rewrite reference leak checker without finalizers.Dean Deng
Our current reference leak checker uses finalizers to verify whether an object has reached zero references before it is garbage collected. There are multiple problems with this mechanism, so a rewrite is in order. With finalizers, there is no way to guarantee that a finalizer will run before the program exits. When an unreachable object with a finalizer is garbage collected, its finalizer will be added to a queue and run asynchronously. The best we can do is run garbage collection upon sandbox exit to make sure that all finalizers are enqueued. Furthermore, if there is a chain of finalized objects, e.g. A points to B points to C, garbage collection needs to run multiple times before all of the finalizers are enqueued. The first GC run will register the finalizer for A but not free it. It takes another GC run to free A, at which point B's finalizer can be registered. As a result, we need to run GC as many times as the length of the longest such chain to have a somewhat reliable leak checker. Finally, a cyclical chain of structs pointing to one another will never be garbage collected if a finalizer is set. This is a well-known issue with Go finalizers (https://github.com/golang/go/issues/7358). Using leak checking on filesystem objects that produce cycles will not work and even result in memory leaks. The new leak checker stores reference counted objects in a global map when leak check is enabled and removes them once they are destroyed. At sandbox exit, any remaining objects in the map are considered as leaked. This provides a deterministic way of detecting leaks without relying on the complexities of finalizers and garbage collection. This approach has several benefits over the former, including: - Always detects leaks of objects that should be destroyed very close to sandbox exit. The old checker very rarely detected these leaks, because it relied on garbage collection to be run in a short window of time. - Panics if we forgot to enable leak check on a ref-counted object (we will try to remove it from the map when it is destroyed, but it will never have been added). - Can store extra logging information in the map values without adding to the size of the ref count struct itself. With the size of just an int64, the ref count object remains compact, meaning frequent operations like IncRef/DecRef are more cache-efficient. - Can aggregate leak results in a single report after the sandbox exits. Instead of having warnings littered in the log, which were non-deterministically triggered by garbage collection, we can print all warning messages at once. Note that this could also be a limitation--the sandbox must exit properly for leaks to be detected. Some basic benchmarking indicates that this change does not significantly affect performance when leak checking is enabled, which is understandable since registering/unregistering is only done once for each filesystem object. Updates #1486. PiperOrigin-RevId: 338685972
2020-10-20Fix nogo test in //pkg/tcpip/...Ting-Yu Wang
PiperOrigin-RevId: 338168977
2020-10-16Don't include link header when forwarding packetsGhanan Gowripalan
Before this change, if a link header was included in an incoming packet that is forwarded, the packet that gets sent out will take the original packet and add a link header to it while keeping the old link header. This would make the sent packet look like: OUTGOING LINK HDR | INCOMING LINK HDR | NETWORK HDR | ... Obviously this is incorrect as we should drop the incoming link header and only include the outgoing link header. This change fixes this bug. Test: integration_test.TestForwarding PiperOrigin-RevId: 337571447
2020-10-09Automated rollback of changelist 336304024Ghanan Gowripalan
PiperOrigin-RevId: 336339194
2020-10-09Automated rollback of changelist 336185457Bhasker Hariharan
PiperOrigin-RevId: 336304024
2020-10-08Do not resolve routes immediatelyGhanan Gowripalan
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
2020-09-18Use common parsing utilities when sniffingGhanan Gowripalan
Extract parsing utilities so they can be used by the sniffer. Fixes #3930 PiperOrigin-RevId: 332401880
2020-09-16Gracefully translate unknown errno.Ting-Yu Wang
Neither POSIX.1 nor Linux defines an upperbound for errno. PiperOrigin-RevId: 332085017
2020-08-25Use new reference count utility throughout gvisor.Dean Deng
This uses the refs_vfs2 template in vfs2 as well as objects common to vfs1 and vfs2. Note that vfs1-only refcounts are not replaced, since vfs1 will be deleted soon anyway. The following structs now use the new tool, with leak check enabled: devpts:rootInode fuse:inode kernfs:Dentry kernfs:dir kernfs:readonlyDir kernfs:StaticDirectory proc:fdDirInode proc:fdInfoDirInode proc:subtasksInode proc:taskInode proc:tasksInode vfs:FileDescription vfs:MountNamespace vfs:Filesystem sys:dir kernel:FSContext kernel:ProcessGroup kernel:Session shm:Shm mm:aioMappable mm:SpecialMappable transport:queue And the following use the template, but because they currently are not leak checked, a TODO is left instead of enabling leak check in this patch: kernel:FDTable tun:tunEndpoint Updates #1486. PiperOrigin-RevId: 328460377
2020-08-24Bump build constraints to 1.17Michael Pratt
This enables pre-release testing with 1.16. The intention is to replace these with a nogo check before the next release. PiperOrigin-RevId: 328193911
2020-08-13Migrate to PacketHeader API for PacketBuffer.Ting-Yu Wang
Formerly, when a packet is constructed or parsed, all headers are set by the client code. This almost always involved prepending to pk.Header buffer or trimming pk.Data portion. This is known to prone to bugs, due to the complexity and number of the invariants assumed across netstack to maintain. In the new PacketHeader API, client will call Push()/Consume() method to construct/parse an outgoing/incoming packet. All invariants, such as slicing and trimming, are maintained by the API itself. NewPacketBuffer() is introduced to create new PacketBuffer. Zero value is no longer valid. PacketBuffer now assumes the packet is a concatenation of following portions: * LinkHeader * NetworkHeader * TransportHeader * Data Any of them could be empty, or zero-length. PiperOrigin-RevId: 326507688
2020-08-11Fix-up issue comment.Adin Scannell
PiperOrigin-RevId: 326129258
2020-08-03Plumbing context.Context to DecRef() and Release().Nayana Bidari
context is passed to DecRef() and Release() which is needed for SO_LINGER implementation. PiperOrigin-RevId: 324672584
2020-07-22Support for receiving outbound packets in AF_PACKET.Bhasker Hariharan
Updates #173 PiperOrigin-RevId: 322665518
2020-07-15fdbased: Vectorized write for packet; relax writev syscall filter.Ting-Yu Wang
Now it calls pkt.Data.ToView() when writing the packet. This may require copying when the packet is large, which puts the worse case in an even worse situation. This sent out in a separate preparation change as it requires syscall filter changes. This change will be followed by the change for the adoption of the new PacketHeader API. PiperOrigin-RevId: 321447003
2020-07-15Fix minor bugs in a couple of interface IOCTLs.Bhasker Hariharan
gVisor incorrectly returns the wrong ARP type for SIOGIFHWADDR. This breaks tcpdump as it tries to interpret the packets incorrectly. Similarly, SIOCETHTOOL is used by tcpdump to query interface properties which fails with an EINVAL since we don't implement it. For now change it to return EOPNOTSUPP to indicate that we don't support the query rather than return EINVAL. NOTE: ARPHRD types for link endpoints are distinct from NIC capabilities and NIC flags. In Linux all 3 exist eg. ARPHRD types are stored in dev->type field while NIC capabilities are more like the device features which can be queried using SIOCETHTOOL but not modified and NIC Flags are fields that can be modified from user space. eg. NIC status (UP/DOWN/MULTICAST/BROADCAST) etc. Updates #2746 PiperOrigin-RevId: 321436525
2020-07-13Fix recvMMsgDispatcher not slicing link header correctly.Ting-Yu Wang
PiperOrigin-RevId: 321035635
2020-07-06Fix NonBlockingWrite3 not writing b3 if b2 is zero-length.Ting-Yu Wang
PiperOrigin-RevId: 319882171
2020-06-22Extract common nested LinkEndpoint patternBruno Dal Bo
... and unify logic for detached netsted endpoints. sniffer.go caused crashes if a packet delivery is attempted when the dispatcher is nil. Extracted the endpoint nesting logic into a common composable type so it can be used by the Fuchsia Netstack (the pattern is widespread there). PiperOrigin-RevId: 317682842
2020-06-10Remove duplicate and incorrect size checkTamir Duberstein
Minimum header sizes are already checked in each `case` arm below. Worse, the ICMP entries in transportProtocolMinSizes are incorrect, and produce false "raw packet" logs. PiperOrigin-RevId: 315730073
2020-06-10Replace use of %v in snifferTamir Duberstein
PiperOrigin-RevId: 315711208
2020-06-03Pass PacketBuffer as pointer.Ting-Yu Wang
Historically we've been passing PacketBuffer by shallow copying through out the stack. Right now, this is only correct as the caller would not use PacketBuffer after passing into the next layer in netstack. With new buffer management effort in gVisor/netstack, PacketBuffer will own a Buffer (to be added). Internally, both PacketBuffer and Buffer may have pointers and shallow copying shouldn't be used. Updates #2404. PiperOrigin-RevId: 314610879
2020-05-29Update Go version build tagsMichael Pratt
None of the dependencies have changed in 1.15. It may be possible to simplify some of the wrappers in rawfile following 1.13, but that can come in a later change. PiperOrigin-RevId: 313863264
2020-05-27Remove linkEP from DeliverNetworkPacketSam Balana
The specified LinkEndpoint is not being used in a significant way. No behavior change, existing tests pass. This change is a breaking change. PiperOrigin-RevId: 313496602
2020-05-27Fix tiny typo.Kevin Krakauer
PiperOrigin-RevId: 313414690
2020-05-11Automated rollback of changelist 310417191Bhasker Hariharan
PiperOrigin-RevId: 310963404
2020-05-07Automated rollback of changelist 309339316Bhasker Hariharan
PiperOrigin-RevId: 310417191
2020-05-06sniffer: fix accidental logging of good packets as badKevin Krakauer
We need to check vv.Size() instead of len(tcp), as tcp will always be 20 bytes long. PiperOrigin-RevId: 310218351
2020-05-01Automated rollback of changelist 308674219Kevin Krakauer
PiperOrigin-RevId: 309491861
2020-04-30Enable FIFO QDisc by default in runsc.Bhasker Hariharan
Updates #231 PiperOrigin-RevId: 309339316
2020-04-30FIFO QDisc implementationBhasker Hariharan
Updates #231 PiperOrigin-RevId: 309323808
2020-04-27Automated rollback of changelist 308163542gVisor bot
PiperOrigin-RevId: 308674219
2020-04-23Remove View.First() and View.RemoveFirst()Kevin Krakauer
These methods let users eaily break the VectorisedView abstraction, and allowed netstack to slip into pseudo-enforcement of the "all headers are in the first View" invariant. Removing them and replacing with PullUp(n) breaks this reliance and will make it easier to add iptables support and rework network buffer management. The new View.PullUp(n) method is low cost in the common case, when when all the headers fit in the first View. PiperOrigin-RevId: 308163542
2020-04-21Automated rollback of changelist 307477185gVisor bot
PiperOrigin-RevId: 307598974
2020-04-17Remove View.First() and View.RemoveFirst()Kevin Krakauer
These methods let users eaily break the VectorisedView abstraction, and allowed netstack to slip into pseudo-enforcement of the "all headers are in the first View" invariant. Removing them and replacing with PullUp(n) breaks this reliance and will make it easier to add iptables support and rework network buffer management. The new View.PullUp(n) method is low cost in the common case, when when all the headers fit in the first View.
2020-04-17Allow caller-defined sinks for packet sniffing.Tamir Duberstein
PiperOrigin-RevId: 307053624
2020-04-16Properly delegate WaitTamir Duberstein
PiperOrigin-RevId: 306959393
2020-04-15Deduplicate packet loggingTamir Duberstein
PiperOrigin-RevId: 306677789
2020-04-14Reduce flakiness in tcp_test.Bhasker Hariharan
Tests now use a MinRTO of 3s instead of default 200ms. This reduced flakiness in a lot of the congestion control/recovery tests which were flaky due to retransmit timer firing too early in case the test executors were overloaded. This change also bumps some of the timeouts in tests which were too sensitive to timer variations and reduces the number of slow start iterations which can make the tests run for too long and also trigger retansmit timeouts etc if the executor is overloaded. PiperOrigin-RevId: 306562645
2020-04-08Fix all printf formatting errors.Adin Scannell
Updates #2243
2020-04-03Refactor software GSO code.Bhasker Hariharan
Software GSO implementation currently has a complicated code path with implicit assumptions that all packets to WritePackets carry same Data and it does this to avoid allocations on the path etc. But this makes it hard to reuse the WritePackets API. This change breaks all such assumptions by introducing a new Vectorised View API ReadToVV which can be used to cleanly split a VV into multiple independent VVs. Further this change also makes packet buffers linkable to form an intrusive list. This allows us to get rid of the array of packet buffers that are passed in the WritePackets API call and replace it with a list of packet buffers. While this code does introduce some more allocations in the benchmarks it doesn't cause any degradation. Updates #231 PiperOrigin-RevId: 304731742
2020-03-24Add support for setting TCP segment hash.Bhasker Hariharan
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
2020-03-24Move tcpip.PacketBuffer and IPTables to stack package.Bhasker Hariharan
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
2020-03-16Enable ARP resolution in TAP devices.Ting-Yu Wang
PiperOrigin-RevId: 301208471
2020-03-16Prevent vnetHdr from escaping in WritePacket.Bhasker Hariharan
PiperOrigin-RevId: 301157950
2020-03-13Fix typoMichael Pratt
PiperOrigin-RevId: 300832988
2020-02-21Implement tap/tun device in vfs.Ting-Yu Wang
PiperOrigin-RevId: 296526279
2020-01-31Use multicast Ethernet address for multicast NDPGhanan Gowripalan
As per RFC 2464 section 7, an IPv6 packet with a multicast destination address is transmitted to the mapped Ethernet multicast address. Test: - ipv6.TestLinkResolution - stack_test.TestDADResolve - stack_test.TestRouterSolicitation PiperOrigin-RevId: 292610529
2020-01-27Refactor to hide C from channel.Endpoint.Ting-Yu Wang
This is to aid later implementation for /dev/net/tun device. PiperOrigin-RevId: 291746025
2020-01-27Standardize on tools directory.Adin Scannell
PiperOrigin-RevId: 291745021
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