Closes [nimbus-eth1#767](https://github.com/status-im/nimbus-eth1/issues/767).
Crashes occur when certain invalid RLPx messages are received from a peer.
Specifically, `msgId` out of range. Because any peer can easily trigger this
crash, we'd consider it a DOS vulnerability if Nimbus-eth1 was in general use.
We noticed when syncing to Goerli, there were some rare crashes with this
exception. It turned out one peer with custom code, perhaps malfunctioning,
was sending these messages if we were unlucky enough to connect to it.
`invokeThunk` is called from `dispatchMessages` and checks the range of
`msgId`. It correctly recognise that it's out of range, raises and exception
and produces a message. Job done.
Except the code in `dispatchMessage` treats all that as a warning instead of
error, and continues to process the message. A bit lower down, `msgId` is used
again without a range check.
The trivial fix is to check array bounds before access.
--
ps. Here's the stack trace ("reraised" sections hidden):
```
WRN 2021-11-08 21:29:33.238+00:00 Error while handling RLPx message topics="rlpx" tid=2003472 file=rlpx.nim:607 peer=Node[<IP>:45456] msg=45 err="RLPx message with an invalid id 45 on a connection supporting eth,snap"
/home/jamie/Status/nimbus-eth1/nimbus/p2p/chain/chain_desc.nim(437) main
/home/jamie/Status/nimbus-eth1/nimbus/p2p/chain/chain_desc.nim(430) NimMain
/home/jamie/Status/nimbus-eth1/nimbus/nimbus.nim(258) process
/home/jamie/Status/nimbus-eth1/vendor/nim-chronos/chronos/asyncloop.nim(279) poll
/home/jamie/Status/nimbus-eth1/vendor/nim-chronos/chronos/asyncmacro2.nim(74) colonanonymous
/home/jamie/Status/nimbus-eth1/vendor/nim-eth/eth/p2p/rlpx.nim(1218) rlpxAccept
/home/jamie/Status/nimbus-eth1/vendor/nim-chronos/chronos/asyncmacro2.nim(101) postHelloSteps
/home/jamie/Status/nimbus-eth1/vendor/nim-chronos/chronos/asyncmacro2.nim(74) colonanonymous
/home/jamie/Status/nimbus-eth1/vendor/nim-eth/eth/p2p/rlpx.nim(985) postHelloSteps
/home/jamie/Status/nimbus-eth1/vendor/nim-chronos/chronos/asyncmacro2.nim(101) dispatchMessages
/home/jamie/Status/nimbus-eth1/vendor/nim-chronos/chronos/asyncmacro2.nim(77) colonanonymous
/home/jamie/Status/nimbus-eth1/vendor/nim-eth/eth/p2p/rlpx.nim(614) dispatchMessages
/home/jamie/Status/nimbus-eth1/vendor/nimbus-build-system/vendor/Nim/lib/system/chcks.nim(23) raiseIndexError2
/home/jamie/Status/nimbus-eth1/vendor/nimbus-build-system/vendor/Nim/lib/system/fatal.nim(49) sysFatal
[[reraised from: ... ]]
[[reraised from: ... ]]
[[reraised from: ... ]]
[[reraised from: ... ]]
Error: unhandled exception: index 45 not in 0 .. 40 [IndexError]
```
Signed-off-by: Jamie Lokier <jamie@shareable.org>
Separate the logging when the node is not reachable and
enrAutoUpdate is on or off to avoid confusion whether or not the
node might still become reachable.
queryRandom was currently only async for the `enrField` version.
However the basic queryRandom is also exported and thus gets
changed so it can be properly used as async proc.
Also added exports for the modules of which objects are used in
the discovery public API.
toBytes for NodeId wasn't selected by compiler byt if it does
get selected, it will fail on the test cases due to the
countdown that is done in logDistance.
Set to toBytesBE properly now and do countup, that should make
it correct also for BE architecture.
Removed toBytes to avoid confusion and avoid this one being
selected ever. The only place toBytes for NodeId was used is in
sessions.nim makeKey func and there also the stint one
(thus native endianness) was selected in Nim 1.2.x.
Native endianness is fine there as it is only an internal
representation.
* Don't fail ENR decoding when value is an RLP list
* Store RLP raw list in the ENR field pair instead
* Add ENR kList FieldKind so lists can be treated differently
Treated differently now when printing out the ENR, mentioning
that it is a raw RLP list
* Allow for tcp/udp ports to always be configured
- Allow for an ENR to be build with tcp and udp ports also when
no IP address is provided
- In the address set-up always provide best efforttcp and udp ports
also when configuration of external ip (and/or ports) fails.
* Modify nodes verification
* Move nodes verification to separate module
By moving verification to separate module it can be re-used
in different contexts not only in discoveryv5.
Don't treat 3 characters as special in `cmp`. `cmp` for `ProtocolInfo` was
wrong because it ignored all characters after the first 3.
In the wild we have seen protocol names longer than 3 characters. `snap`,
`hive`, `istanbul`, `bzzeth`, `bzz-stream`, `bzz-retrieve`, `dbix`, `opera`,
`pchain`, `pchain_child_0`, `sero`, `smilobft`, `spock`.
There was never a 3 character limit in the [specification]
(https://github.com/ethereum/devp2p/blob/master/rlpx.md).
It always said "short ASCII name", until recently on 2021-02-25 it was changed
to an 8 characters limit.
Also `pi.nameStr` can be removed. Nothing uses it, and it has the same actual
effect as just copying the string `pi.name`.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
For a long time this caused invalid RLP parsing of `NewBlock` messages in the
`eth` protocol.
The `rlpInline` pragma was accepted but had no effect. We could implemented
it, but it doesn't seem worth doing, with tests etc, as there's only one user
which has been fixed another way.
With `NewBlock`, whenever a peer sent us `NewBlock`, we'd get an RLP decoding
error, and disconnected the peer thinking it was the peer's error.
These messages are sent often by good peers, so whenever we connected to a
really good peer, we'd end up disconnecting within a minute due to this. This
went unnoticed for years, as we stayed connected to old peers which have no new
blocks, and we weren't looking at peer quality, disconnect reasons or real-time
blockchain updates anyway.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
* Fix raw Exceptions in hexary caused by forward declarations
* Fix raw Exceptions in trie/db caused by forward declarations
* And now we can remove those db Proc CatchableError raises
`les_protocol.nim` failed to build, due to very silly Nim bugs
nim-lang/Nim#8792 and nim-lang/Nim#17102.
import
../../[rlp, keys], ../../common/eth_types,
../[rlpx, kademlia, blockchain_utils], ../private/p2p_types,
The silly part is `../` has to be quoted if it's before a group of files, but
not before a single file. Most places in PR #344 / 7624153 use the workaround
`".."/` but it was missed in `les_protocol.nim`:
nimbus-eth1/vendor/nim-eth/eth/p2p/rlpx_protocols/les_protocol.nim(14, 3)
Error: cannot open file: ../../[rlp,keys]
Signed-off-by: Jamie Lokier <jamie@shareable.org>
* Add build_dcli target and add it to CI
* Fix local imports for dcli
* And use local imports for all other files too
* Use local imports in tests and rlpx protocols
Fixesstatus-im/nim-eth#341, status-im/nimbus-eth1#489.
When using discv4 (Kademlia) to find peers, there is a crash after a few
minutes. It occurs for most of us on Eth1 mainnet, and everyone on Ropsten.
The cause is `findNodes` being called twice in succession to the same peer,
within about 5 seconds of each other. ("About" 5 seconds, because Chronos does
not guarantee to run the timeout branch at a particular time, due to queuing
and clock reading delays.)
Then `findNodes` sends a duplicate message to the peer and calls
`waitNeighbours` to listen for the reply. There's already a `waitNeighbours`
callback in a shared table, so that function hits an assert failure.
Ignoring the assert would be wrong as it would break timeout logic, and sending
`FindNodes` twice in rapid succession also makes us a bad peer.
As a simple workaround, just skip `findNodes` in this state and return a fake
empty `Neighbours` reply. This is a bit of a hack as `findNodes` should not be
called like this; there's a logic error at a higher level. But it works.
Tested for about 4 days constant operation on Ropsten. The crash which occured
every few minutes no longer occurs, and discv4 keeps working.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
