The changes here are dense and subtle, but hopefully all is more explicit
than before.
- CConnman is now in charge of sending data rather than the nodes themselves.
This is necessary because many decisions need to be made with all nodes in
mind, and a model that requires the nodes calling up to their manager quickly
turns to spaghetti.
- The per-node-serializer (ssSend) has been replaced with a (quasi-)const
send-version. Since the send version for serialization can only change once
per connection, we now explicitly tag messages with INIT_PROTO_VERSION if
they are sent before the handshake. With this done, there's no need to lock
for access to nSendVersion.
Also, a new stream is used for each message, so there's no need to lock
during the serialization process.
- This takes care of accounting for optimistic sends, so the
nOptimisticBytesWritten hack can be removed.
- -dropmessagestest and -fuzzmessagestest have not been preserved, as I suspect
they haven't been used in years.
f5b960b Move nTimeBestReceived updating into net processing code (Matt Corallo)
d8670fb Move all calls to CheckBlockIndex out of net-processing logic (Matt Corallo)
d6ea737 Remove network state wipe from UnloadBlockIndex. (Matt Corallo)
fc0c24f Move MarkBlockAsReceived out of ProcessNewMessage (Matt Corallo)
65f35eb Move FlushStateToDisk call out of ProcessMessages::TX into ATMP (Matt Corallo)
This introduces a 'minimum chain work' chainparam which is intended
to be the known amount of work in the chain for the network at the
time of software release. If you don't have this much work, you're
not yet caught up.
This is used instead of the count of blocks test from checkpoints.
This criteria is trivial to keep updated as there is no element of
subjectivity, trust, or position dependence to it. It is also a more
reliable metric of sync status than a block count.
This will result in many more calls to CheckBlockIndex when
connecting a list of headers (eg in ::HEADERS messages processing)
but its only enabled in debug mode, and that should mostly just be
during IBD, so it should be OK.
UnloadBlockIndex is only used during init if we end up reindexing
to clear our block state so that we can start over. However, at
that time no connections have been brought up as CConnman hasn't
been started yet, so all of the network processing state logic is
empty when its called.
Additionally, the initialization of the recentRejects set is moved
to InitPeerLogic.
This change is needed to prevent sync_blocks timeouts in the mempool_reorg
test after the sync_blocks update in the upcoming commit
"[qa] Change sync_blocks to pick smarter maxheight".
This change was initially suggested by Suhas Daftuar <sdaftuar@chaincode.com>
in https://github.com/bitcoin/bitcoin/pull/8680#r78209060
0334430 Add some missing includes (Pieter Wuille)
4100499 Return shared_ptr<CTransaction> from mempool removes (Pieter Wuille)
51f2783 Make removed and conflicted arguments optional to remove (Pieter Wuille)
f48211b Bypass removeRecursive in removeForReorg (Pieter Wuille)
Note that this is not a major issue as, in order for the missing
lock to cause issues, you have to receive a GETBLOCKTXN message
while reindexing, adding a block header via RPC, etc, which results
in either a table rehash or an insert into the bucket which you are
currently looking at.
a9aec5c Use BlockChecked signal to send reject messages from mapBlockSource (Matt Corallo)
7565e03 Remove SyncWithWallets wrapper function (Matt Corallo)
12ee1fe Always call UpdatedBlockTip, even if blocks were only disconnected (Matt Corallo)
f5efa28 Remove CConnman parameter from ProcessNewBlock/ActivateBestChain (Matt Corallo)
fef1010 Use CValidationInterface from chain logic to notify peer logic (Matt Corallo)
aefcb7b Move net-processing logic definitions together in main.h (Matt Corallo)
0278fb5 Remove duplicate nBlocksEstimate cmp (we already checked IsIBD()) (Matt Corallo)
87e7d72 Make validationinterface.UpdatedBlockTip more verbose (Matt Corallo)
3ac6de0 Align constant names for maximum compact block / blocktxn depth (Pieter Wuille)
b2e93a3 Add cmpctblock to debug help list (instagibbs)
fe998e9 More agressively filter compact block requests (Matt Corallo)
02a337d Dont remove a "preferred" cmpctblock peer if they provide a block (Matt Corallo)
67d6ee1 remove redundant tests in p2p-segwit.py (Johnson Lau)
9260085 test segwit uncompressed key fixes (Johnson Lau)
248f3a7 Fix ismine and addwitnessaddress: no uncompressed keys in segwit (Pieter Wuille)
b811124 [qa] Add tests for uncompressed pubkeys in segwit (Suhas Daftuar)
9f0397a Make test framework produce lowS signatures (Johnson Lau)
4c0c25a Require compressed keys in segwit as policy and disable signing with uncompressed keys for segwit scripts (Johnson Lau)
3ade2f6 Add standard limits for P2WSH with tests (Johnson Lau)
There are only a few uses of `insecure_random` outside the tests.
This PR replaces uses of insecure_random (and its accompanying global
state) in the core code with an FastRandomContext that is automatically
seeded on creation.
This is meant to be used for inner loops. The FastRandomContext
can be in the outer scope, or the class itself, then rand32() is used
inside the loop. Useful e.g. for pushing addresses in CNode or the fee
rounding, or randomization for coin selection.
As a context is created per purpose, thus it gets rid of
cross-thread unprotected shared usage of a single set of globals, this
should also get rid of the potential race conditions.
- I'd say TxMempool::check is not called enough to warrant using a special
fast random context, this is switched to GetRand() (open for
discussion...)
- The use of `insecure_rand` in ConnectThroughProxy has been replaced by
an atomic integer counter. The only goal here is to have a different
credentials pair for each connection to go on a different Tor circuit,
it does not need to be random nor unpredictable.
- To avoid having a FastRandomContext on every CNode, the context is
passed into PushAddress as appropriate.
There remains an insecure_random for test usage in `test_random.h`.
1df3111 protocol.h: Make enums in GetDataMsg concrete values (Wladimir J. van der Laan)
2c09a52 protocol.h: Move MESSAGE_START_SIZE into CMessageHeader (Wladimir J. van der Laan)
f9bd92d version.h: s/shord/short/ in comment (Wladimir J. van der Laan)
This adds a new CValidationInterface subclass, defined in main.h,
to receive notifications of UpdatedBlockTip and use that to push
blocks to peers, instead of doing it directly from
ActivateBestChain.
In anticipation of making all the callbacks out of block processing
flow through it. Note that vHashes will always have something in it
since pindexFork != pindexNewTip.
This fixes a bug where we might (in exceedingly rare circumstances)
accidentally ban a node for sending us the first (potentially few)
segwit blocks in non-segwit mode.
75ead758 turned these into crashes in the event of a handshake failure, most
notably when a peer does not offer the expected services.
There are likely other cases that these assertions will find as well.
In principle, the checksums of P2P packets are simply 4-byte blobs which
are the first four bytes of SHA256(SHA256(payload)).
Currently they are handled as little-endian 32-bit integers half of the
time, as blobs the other half, sometimes copying the one to the other,
resulting in somewhat confused code.
This PR changes the handling to be consistent both at packet creation
and receiving, making it (I think) easier to understand.
An example of where this might be useful is allowing a node to connect blocksonly during IBD but then becoming a full-node once caught up with the latest block. This might also even want to be the default behaviour since during IBD most TXs appear to be orphans, and are routinely dropped (for example when a node disconnects). Therefore, this can waste a lot of bandwidth.
Additionally, another pull could be written to stop relaying of TXs to nodes that are clearly far behind the latest block and are running a node that doesn't store many orphan TXs, such as recent versions of Bitcoin Core.
CConnman then passes the current best height into CNode at creation time.
This way CConnman/CNode have no dependency on main for height, and the signals
only move in one direction.
This also helps to prevent identity leakage a tiny bit. Before this change, an
attacker could theoretically make 2 connections on different interfaces. They
would connect fully on one, and only establish the initial connection on the
other. Once they receive a new block, they would relay it to your first
connection, and immediately commence the version handshake on the second. Since
the new block height is reflected immediately, they could attempt to learn
whether the two connections were correlated.
This is, of course, incredibly unlikely to work due to the small timings
involved and receipt from other senders. But it doesn't hurt to lock-in
nBestHeight at the time of connection, rather than letting the remote choose
the time.
This behavior seems to have been quite racy and broken.
Move nLocalHostNonce into CNode, and check received nonces against all
non-fully-connected nodes. If there's a match, assume we've connected
to ourself.
35fe039 Rename to PrecomputedTransactionData (Pieter Wuille)
ab48c5e Unit test for sighash caching (Nicolas DORIER)
d2c5d04 Precompute sighashes (Pieter Wuille)
We should learn about new peers via address messages.
An inbound peer connecting to us tells us nothing about
its ability to accept incoming connections from us, so
we shouldn't assume that we can connect to it based on
this.
The vast majority of nodes on the network do not accept
incoming connections, adding them will only slow down
the process of making a successful connection in the
future.
Nodes which have configured themselves to not announce would prefer we
not violate their privacy by announcing them in GETADDR responses.
Tests if addresses are online or offline by briefly connecting to them. These short lived connections are referred to as feeler connections. Feeler connections are designed to increase the number of fresh online addresses in tried by selecting and connecting to addresses in new. One feeler connection is attempted on average once every two minutes.
This change was suggested as Countermeasure 4 in
Eclipse Attacks on Bitcoin’s Peer-to-Peer Network, Ethan Heilman,
Alison Kendler, Aviv Zohar, Sharon Goldberg. ePrint Archive Report
2015/263. March 2015.
