* Revert "Remove commented-out code"
This reverts commit 9e69777925f103ee11e5940bba95b896c828839b.
* Implement deserialization for `addrv2` messages
* Limit addr and addrv2 messages to MAX_ADDRS_IN_MESSAGE
* Clarify address version comments
* Minor cleanups and fixes
* Add preallocation tests for AddrV2
* Add serialization tests for AddrV2
* Use prop_assert in AddrV2 proptests
* Use a generic utility method for deserializing IP addresses in `addrv2`
* Document the purpose of a conversion to MetaAddr
* Fix a comment typo, and clarify that comment
* Clarify the unsupported AddrV2 network ID error and enum variant names
```sh
fastmod AddrV2UnimplementedError UnsupportedAddrV2NetworkIdError zebra-network
fastmod Unimplemented Unsupported zebra-network
```
* Fix and clarify unsupported AddrV2 comments
* Replace `panic!` with `unreachable!`
* Clarify a comment about skipping a length check in a test
* Remove a redundant test
* Basic addr (v1) and addrv2 deserialization tests
* Test deserialized IPv4 and IPv6 values in addr messages
* Remove redundant io::Cursor
* Add comments with expected values of address test vectors
* Implement addr v1 serialization using a separate AddrV1 type
* Remove commented-out code
* Split the address serialization code into modules
* Reorder v1 and in_version fields in serialization order
* Fix a missed search-and-replace
* Explain conversion to MetaAddr
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Check return value of zcash_script_new_precomputed_tx
* Set the NU5 testnet activation height to 1_590_000
* Apply suggestions from code review
Co-authored-by: teor <teor@riseup.net>
* Update Nu5 constants to new values
* Update ZIP-244 test vectors for new branch ID
* Squashed commit of the following:
commit bdb120a249
Author: Deirdre Connolly <durumcrustulum@gmail.com>
Date: Tue Oct 5 11:54:01 2021 -0400
Use pallas::Base::from_str_vartime() in sinsemilla tests
commit e99fa49258
Author: Deirdre Connolly <durumcrustulum@gmail.com>
Date: Tue Oct 5 11:45:24 2021 -0400
Compiles
commit a520018114
Author: Deirdre Connolly <durumcrustulum@gmail.com>
Date: Tue Oct 5 10:15:17 2021 -0400
Incomplete upgrade of deps
* Squashed commit of the following:
commit 8d1b76ec5626517817c3a4d9f3950acc90a359df
Author: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Date: Tue Oct 5 04:02:26 2021 +0000
Update `zcash_script` to support V5 transactions
Use a newer version of `zcash_script` that has been updated to support
V5 transactions.
commit 371233628ae61e0c25d6ba8f31d9dba42823becb
Author: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Date: Tue Oct 5 03:06:20 2021 +0000
Update Zcash dependencies
Update some Zcash crates:
- `halo2`
- `incrementalmerkletree' (patch version)
- `orchard` (patch version)
- `zcash_history` (patch version)
- `zcash_note_encryption` (patch version)
- `zcash_primitives` (patch version)
And also update the `group` dependency so that the code remains
compatible.
commit de5cf1ec40c3fc08670fc971cdf3e65e13d9f4c7
Author: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Date: Tue Oct 5 03:04:13 2021 +0000
Update error message assertion
Use the updated message for the expected error variant.
* Update `zcash_script` to support V5 transactions
Use a newer version of `zcash_script` that has been updated to support
V5 transactions.
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
Co-authored-by: teor <teor@riseup.net>
* Add tracing and metrics for seed peer DNS resolution
* Add a grafana dashboard for seed peers
Currently this just shows the initial peer count from each seed.
* Add tracing and metrics for peer network protocol versions
* Update peers dashboard with network protocol versions
* Show peer network protocol versions for each seeder in dashboard
* Add per-seed filter to dashboard
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
* Use `MockService` in inbound test
Refactor the `mempool_requsets_for_transactions` test so that it uses a
`MockService` instead of the `mock_peer_set` function.
* Use `MockService` in the basic mempool test
Refactor the `mempool_service_basic` test so that it uses a
`MockService` instead of the `mock_peer_set` helper function.
* Remove the `mock_peer_set` helper function
It is not used anymore, since the usages were replaced with
`MockService`s.
* add tests for mempool inbound requests
* Use MockService for transaction verifier
* Refactor creation of mock `peer_set`
Use the same style as the mock transaction verifier.
* Derive `Eq` for `zebra_network::Request`
Make it easy to use the `MockService::expect_request` method.
* Return mocked peer set service from `setup`
Allow it to be used to respond to requests.
* Add bindings for the transaction used for testing
Allow them to be moved into futures later.
* Respond to transaction download request
Make sure that the test transaction appears to the mempool as if it had
been downloaded by the peer set service.
* Assert that no unexpected requests were received
Check that the mempool doesn't send unexpected requests to the peer set
service.
* add tests for mempool inbound requests
* Use MockService for transaction verifier
* add missing `expect_no_requests` to `mempool_advertise_transaction_ids` test
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
* Rename internal network requests for wide transaction IDs
fastmod TransactionsByHash TransactionsById zebra*
fastmod AdvertiseTransactions AdvertiseTransactionIds zebra*
fastmod MempoolTransactions MempoolTransactionIds zebra*
fastmod TransactionHashes TransactionIds zebra*
* Update network transaction request/response comments
* Rename a transaction hash method for wide transaction IDs
fastmod transaction_hashes transaction_ids zebra-network
* Add UnminedTxId methods and conversions for InventoryHash
* Map WtxIds to unmined transaction network messages
Also, use UnminedTxId and UnminedTx in:
* Zebra's internal request and response format, and
* external Zcash network protocol messages.
* Enable WtxId mempool inventory tracking for peers
* Further clarify transaction IDs
* Use Witnessed rather than Wide for transaction IDs
And rename narrow to legacy when it only applies to v1-v4 transactions.
Otherwise, rename it to mined ID.
* Rename a missed binding
* Remove an incorrectly named binding
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Make the `AuthDigest` display order match transaction IDs
And derive `Hash`, just like transaction IDs.
Don't derive `serde` for now, because it's not needed.
* Move transaction::Hash test to tests module
* Add a simple AuthDigest display order test
* Add a WtxId type for wide transaction IDs
* Add conversions between transaction IDs and bytes
* Use the WtxId type in external network protocol messages
* Simplify state service initialization in test
Use the test helper function to remove redundant code.
* Create `BestTipHeight` helper type
This type abstracts away the calculation of the best tip height based on
the finalized block height and the best non-finalized chain's tip.
* Add `best_tip_height` field to `StateService`
The receiver endpoint is currently ignored.
* Return receiver endpoint from service constructor
Make it available so that the best tip height can be watched.
* Update finalized height after finalizing blocks
After blocks from the queue are finalized and committed to disk, update
the finalized block height.
* Update best non-finalized height after validation
Update the value of the best non-finalized chain tip block height after
a new block is committed to the non-finalized state.
* Update finalized height after loading from disk
When `FinalizedState` is first created, it loads the state from
persistent storage, and the finalized tip height is updated. Therefore,
the `best_tip_height` must be notified of the initial value.
* Update the finalized height on checkpoint commit
When a checkpointed block is commited, it bypasses the non-finalized
state, so there's an extra place where the finalized height has to be
updated.
* Add `best_tip_height` to `Handshake` service
It can be configured using the `Builder::with_best_tip_height`. It's
currently not used, but it will be used to determine if a connection to
a remote peer should be rejected or not based on that peer's protocol
version.
* Require best tip height to init. `zebra_network`
Without it the handshake service can't properly enforce the minimum
network protocol version from peers. Zebrad obtains the best tip height
endpoint from `zebra_state`, and the test vectors simply use a dummy
endpoint that's fixed at the genesis height.
* Pass `best_tip_height` to proto. ver. negotiation
The protocol version negotiation code will reject connections to peers
if they are using an old protocol version. An old version is determined
based on the current known best chain tip height.
* Handle an optional height in `Version`
Fallback to the genesis height in `None` is specified.
* Reject connections to peers on old proto. versions
Avoid connecting to peers that are on protocol versions that don't
recognize a network update.
* Document why peers on old versions are rejected
Describe why it's a security issue above the check.
* Test if `BestTipHeight` starts with `None`
Check if initially there is no best tip height.
* Test if best tip height is max. of latest values
After applying a list of random updates where each one either sets the
finalized height or the non-finalized height, check that the best tip
height is the maximum of the most recently set finalized height and the
most recently set non-finalized height.
* Add `queue_and_commit_finalized` method
A small refactor to make testing easier. The handling of requests for
committing non-finalized and finalized blocks is now more consistent.
* Add `assert_block_can_be_validated` helper
Refactor to move into a separate method some assertions that are done
before a block is validated. This is to allow moving these assertions
more easily to simplify testing.
* Remove redundant PoW block assertion
It's also checked in
`zebra_state::service::check::block_is_contextually_valid`, and it was
getting in the way of tests that received a gossiped block before
finalizing enough blocks.
* Create a test strategy for test vector chain
Splits a chain loaded from the test vectors in two parts, containing the
blocks to finalize and the blocks to keep in the non-finalized state.
* Test committing blocks update best tip height
Create a mock blockchain state, with a chain of finalized blocks and a
chain of non-finalized blocks. Commit all the blocks appropriately, and
verify that the best tip height is updated.
Co-authored-by: teor <teor@riseup.net>
* Rename constant to `MIN_INVENTORY_HASH_SIZE`
Because the size is not constant anymore, since the `MSG_WTX` inventory
type is larger.
* Add `InventoryHash::smallest_types_strategy`
A method for a proptest strategy that generates the `InventoryHash`
variants that have the smallest serialized size.
* Update proptest to use only smallest inventories
In order to properly test the maximum allocation.
* Add intra-doc links in some method documentation
Make it easier to navigate from the documentation of the proptest
strategies to the variants they generate.
* Parse `MSG_WTX` inventory type
Avoid returning an error if a received `GetData` or `Inv` message
contains a `MSG_WTX` inventory type. This prevents Zebra from
disconnecting from peers that announce V5 transactions.
* Fix inventory hash size proptest
The serialized size now depends on what type of `InventoryHash` is being
tested.
* Implement serialization of `InventoryHash::Wtx`
For now it just copies the stored bytes, in order to allow the tests to
run correctly.
* Test if `MSG_WTX` inventory is parsed correctly
Create some mock input bytes representing a serialized `MSG_WTX`
inventory item, and check that it can be deserialized successfully.
* Generate arbitrary `InventoryHash::Wtx` for tests
Create a strategy that only generates `InventoryHash::Wtx` instances,
and also update the `Arbitrary` implementation for `InventoryHash` to
also generate `Wtx` variants.
* Test `InventoryHash` serialization roundtrip
Given an arbitrary `InventoryHash`, check that it does not change after
being serialized and deserialized.
Currently, `InventoryHash::Wtx` can't be serialized, so this test will
is expected to panic for now, but it will fail once the serialization
code is implemented, and then the `should_panic` should be removed.
* Test deserialize `InventoryHash` from random bytes
Create an random input vector of bytes, and try to deserialize an
`InventoryHash` from it. This should either succeed or fail in an
expected way.
* Remove redundant attribute
The attribute is redundant because the `arbitrary` module already has
that attribute.
* Implement `Message::inv_strategy()`
A method to return a proptest strategy that creates `Message::Inv`
instances.
* Implement `Message::get_data_strategy()`
A method that returns a proptest strategy that creates
`Message::GetData` instances.
* Test encode/decode roundtrip of some `Message`s
Create a `Message` instance, encode it and then decode it using a
`Codec` instance and check that the result is the same as the initial
`Message`.
For now, this only tests `Message::Inv` and `Message::GetData`, because
these are the variants that are related to the scope of the current set
of changes to support parsing the `MSG_WTX` inventory type.
Even so, the test relies on being able to serialize an
`InventoryHash::Wtx`, which is currently not implemented. Therefore the
test was marked as `should_panic` until the serialization code is
implemented.
* Support a min protocol version during initial block download
But don't actually use the state height yet.
Also rename some functions and constants.
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Security: Limit reconnection rate to individual peers
Reconnection Rate
Limit the reconnection rate to each individual peer by applying the
liveness cutoff to the attempt, responded, and failure time fields.
If any field is recent, the peer is skipped.
The new liveness cutoff skips any peers that have recently been attempted
or failed. (Previously, the liveness check was only applied if the peer
was in the `Responded` state, which could lead to repeated retries of
`Failed` peers, particularly in small address books.)
Reconnection Order
Zebra prefers more useful peer states, then the earliest attempted,
failed, and responded times, then the most recent gossiped last seen
times.
Before this change, Zebra took the most recent time in all the peer time
fields, and used that time for liveness and ordering. This led to
confusion between trusted and untrusted data, and success and failure
times.
Unlike the previous order, the new order:
- tries all peers in each state, before re-trying any peer in that state,
and
- only checks the the gossiped untrusted last seen time
if all other times are equal.
* Preserve the later time if changes arrive out of order
* Update CandidateSet::next documentation
* Update CandidateSet state diagram
* Fix variant names in comments
* Explain why timestamps can be left out of MetaAddrChanges
* Add a simple test for the individual peer retry limit
* Only generate valid Arbitrary PeerServices values
* Add an individual peer retry limit AddressBook and CandidateSet test
* Stop deleting recently live addresses from the address book
If we delete recently live addresses from the address book, we can get a
new entry for them, and reconnect too rapidly.
* Rename functions to match similar tokio API
* Fix docs for service sorting
* Clarify a comment
* Cleanup a variable and comments
* Remove blank lines in the CandidateSet state diagram
* Add a multi-peer proptest that checks outbound attempt fairness
* Fix a comment typo
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Simplify time maths in MetaAddr
* Create a Duration32 type to simplify calculations and comparisons
* Rename variables for clarity
* Split a string constant into multiple lines
* Make constants match rustdoc order
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
- stop putting inbound addresses in the address book
- drop address book entries that can't be used for outbound connections
- distinguish between temporary inbound and permanent outbound peer
addresses
- also create variants to handle proxy connections
(but don't use them yet)
- avoid tracking connection state for isolated connections
- document security constraints for the address book and peer set
* Security: stop panicking on out-of-range version timestamps
Instead, return a deserialization error, and close the connection.
This issue was reported by Equilibrium.
* Add functions for serializing and deserializing split arrays
In Transaction::V5, Zcash splits some types into multiple arrays, with a
single prefix count before the first array.
Add utility functions for serializing and deserializing the subsequent
arrays, with a paramater for the original array's length.
* Use zcash_deserialize_bytes_external_count in zebra-network
* Move some preallocate proptests to their own file
And fix the test module structure so it is consistent with the rest of
zebra-chain.
* Add a convenience alias zcash_serialize_external_count
* Explain why u64::MAX items will never be reached
* Make proptest dependencies consistent between chain and network
* Implement Arbitrary for InventoryHash and use it in tests
* Impl Arbitrary for MetaAddr and use it in tests
Also test some extreme times in MetaAddr sanitization.
* Move the preallocate tests into their own files
And move the MetaAddr proptest into its own file.
Also do some minor formatting and cleanups.
Co-authored-by: Deirdre Connolly <durumcrustulum@gmail.com>
* Implement SafePreallocate. Resolves#1880
* Add proptests for SafePreallocate
* Apply suggestions from code review
Comments which did not include replacement code will be addressed in a follow-up commit.
Co-authored-by: teor <teor@riseup.net>
* Rename [Safe-> Trusted]Allocate. Add doc and tests
Add tests to show that the largest allowed vec under TrustedPreallocate
is small enough to fit in a Zcash block/message (depending on type).
Add doc comments to all TrustedPreallocate test cases.
Tighten bounds on max_trusted_alloc for some types.
Note - this commit does NOT include TrustedPreallocate
impls for JoinSplitData, String, and Script.
These impls will be added in a follow up commit
* Implement SafePreallocate. Resolves#1880
* Add proptests for SafePreallocate
* Apply suggestions from code review
Comments which did not include replacement code will be addressed in a follow-up commit.
Co-authored-by: teor <teor@riseup.net>
* Rename [Safe-> Trusted]Allocate. Add doc and tests
Add tests to show that the largest allowed vec under TrustedPreallocate
is small enough to fit in a Zcash block/message (depending on type).
Add doc comments to all TrustedPreallocate test cases.
Tighten bounds on max_trusted_alloc for some types.
Note - this commit does NOT include TrustedPreallocate
impls for JoinSplitData, String, and Script.
These impls will be added in a follow up commit
* Impl TrustedPreallocate for Joinsplit
* Impl ZcashDeserialize for Vec<u8>
* Arbitrary, TrustedPreallocate, Serialize, and tests for Spend<SharedAnchor>
Co-authored-by: teor <teor@riseup.net>
Zebra already uses `Read::take` to enforce message, body, and block
maximum sizes.
So using `Read::take` on untrusted sizes can result in short reads,
without a corresponding `UnexpectedEof` error. (The old code was
correct, but copying it elsewhere would have been risky.)
* Add NU5 variant to NetworkUpgrade
* Add consensus branch ID for NU5
* Add network protocol versions for NU5
* Add NU5 to the protocol::version_consistent test
* Make unimplemented panic messages more specific
* Block target spacing doesn't change in NU5
* add comments for future updates for NU5
Co-authored-by: teor <teor@riseup.net>
* Rewrite GetData handling to match the zcashd implementation
`zcashd` silently ignores missing blocks, but sends found transactions
followed by a `NotFound` message:
e7b425298f/src/main.cpp (L5497)
This is significantly different to the behaviour expected by the old
Zebra connection state machine, which expected `NotFound` for blocks.
Also change Zebra's GetData responses to peer request so they ignore
missing blocks.
* Stop hanging on incomplete transaction or block responses
Instead, if the peer sends an unexpected block, unexpected transaction,
or NotFound message:
1. end the request, and return a partial response containing any items
that were successfully received
2. if none of the expected blocks or transactions were received, return
an error, and close the connection
We modeled a Bitcoin `headers` message as being a list of block headers.
However, the actual data structure is slightly different: it's a list of (block
header, transaction count) pairs. This caused zcashd to reject our headers
messages.
To fix this, introduce a new `CountedHeader` struct with a `block::Header` and
transaction count `usize`, then thread it through the inbound service and the
state.
I tested this locally by running Zebra with these changes and inspecting a
trace-level log of the span of a peer connection that requested a nontrivial
headers packet from us, and verified that it did not reject our message.
Not all reject messages include a data field. This change partially addresses
a problem that could lead to a depleted peer set:
1. We send a response to a `getheaders` message;
2. The remote peer `reject`s our `headers` message for some reason;
3. We fail to parse their `reject` message and close the connection;
4. Repeating this process, we have no more peers.
This commit fixes (3) but does not address (2).
This makes the span data more compact (e.g., `msg_as_req{msg=block}`) and
restores the Debug impl for Message to show all of the data contained in the
message. The full message is added as a single event at trace level in the
span to preserve the previous full-inspectability.
* implement inbound `FindBlocks`
* Handle inbound peer FindHeaders requests
* handle request before having any chain tip
* Split `find_chain_hashes` into smaller functions
Add a `max_len` argument to support `FindHeaders` requests.
Rewrite the hash collection code to use heights, so we can handle the
`stop` hash and "no intersection" cases correctly.
* Split state height functions into "any chain" and "best chain"
* Rename the best chain block method to `best_block`
* Move fmt utilities to zebra_chain::fmt
* Summarise Debug for some Message variants
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: Jane Lusby <jlusby42@gmail.com>
This change is mostly mechanical, with the exception of the changes to the
`tower-batch` middleware. This middleware was adapted from `tower::buffer`,
and the `tower::buffer` code was changed to implement its own bounded queue,
because Tokio 0.3 removed the `mpsc::Sender::poll_send` method. See
ddc64e8d4d
for more context on the Tower changes. To match Tower as closely as possible
in order to be able to upstream `tower-batch`, those changes are copied from
`tower::Buffer` to `tower-batch`.
This change explicitly documents cancellation contracts for our Tower services,
and tries to correct a bug in the implementation of the CheckpointVerifier,
which duplicates information from the state service but did not ensure that it
would be kept in sync.
This commit makes several related changes to the network code:
- adds a `TransactionsByHash(HashSet<transaction::Hash>)` request and
`Transactions(Vec<Arc<Transaction>>)` response pair that allows
fetching transactions from a remote peer;
- adds a `PushTransaction(Arc<Transaction>)` request that pushes an
unsolicited transaction to a remote peer;
- adds an `AdvertiseTransactions(HashSet<transaction::Hash>)` request
that advertises transactions by hash to a remote peer;
- adds an `AdvertiseBlock(block::Hash)` request that advertises a block
by hash to a remote peer;
Then, it modifies the connection state machine so that outbound
requests to remote peers are handled properly:
- `TransactionsByHash` generates a `getdata` message and collects the
results, like the existing `BlocksByHash` request.
- `PushTransaction` generates a `tx` message, and returns `Nil` immediately.
- `AdvertiseTransactions` and `AdvertiseBlock` generate an `inv`
message, and return `Nil` immediately.
Next, it modifies the connection state machine so that messages
from remote peers generate requests to the inbound service:
- `getdata` messages generate `BlocksByHash` or `TransactionsByHash`
requests, depending on the content of the message;
- `tx` messages generate `PushTransaction` requests;
- `inv` messages generate `AdvertiseBlock` or `AdvertiseTransactions`
requests.
Finally, it refactors the request routing logic for the peer set to
handle advertisement messages, providing three routing methods:
- `route_p2c`, which uses p2c as normal (default);
- `route_inv`, which uses the inventory registry and falls back to p2c
(used for `BlocksByHash` or `TransactionsByHash`);
- `route_all`, which broadcasts a request to all ready peers (used for
`AdvertiseBlock` and `AdvertiseTransactions`).
This is the first in a sequence of changes that change the block:: items
to not include Block as a prefix in their name, in accordance with the
Rust API guidelines.
This extracts the SHA256d code from being split across two modules and puts it
in one module, under serialization.
The code is unchanged except for three deleted tests:
* `sha256d_flush` in `sha256d_writer` (not a meaningful test);
* `transactionhash_debug` (constructs an invalid transaction hash, and the
behavior is tested in the next test);
* `decode_state_debug` (we do not need to test the Debug output of
DecodeState);
* add bytes read and written metrics
* Apply suggestions from code review
Co-authored-by: Jane Lusby <jlusby42@gmail.com>
* store address as string
* Apply suggestions from code review
Co-authored-by: Henry de Valence <hdevalence@hdevalence.ca>
* change addr to label
Co-authored-by: Henry de Valence <hdevalence@hdevalence.ca>
* remove newline
Co-authored-by: Jane Lusby <jlusby42@gmail.com>
Co-authored-by: Henry de Valence <hdevalence@hdevalence.ca>
We can use this network upgrade to implement different consensus rules
and chain context handling for genesis blocks.
Part of the chain state design in #682.
Bitcoin does this either with `getblocks` (returns up to 500 following block
hashes) or `getheaders` (returns up to 2000 following block headers, not
just hashes). However, Bitcoin headers are much smaller than Zcash
headers, which contain a giant Equihash solution block, and many Zcash
blocks don't have many transactions in them, so the block header is
often similarly sized to the block itself. Because we're
aiming to have a highly parallel network layer, it seems better to use
`getblocks` to implement `FindBlocks` (which is necessarily sequential)
and parallelize the processing of the block downloads.
This doesn't clean the warnings about unused items in the builder, since
those are unused for a reason (the implementation that should use them
is missing).
PushPeers is more complicated to thread into the rest of our
architecture (we would need to establish a data path connecting our
service handling inbound requests to the network layer's auto-crawler),
and since we crawl the network automatically anyways, we don't actually
need to accept them in order to get updated address information.
The only possible problem with this approach is that zcashd refuses to
answer multiple address requests from the same connection, ostensibly
for fingerprinting prevention (although it's totally happy to give
exactly the same information, as long as you hang up and reconnect
first, lol). It's unclear how this will interact with our design -- on
the one hand, it could mean that we don't get new addr information when
we ask, but on the other hand, we may have enough churn in our
connection pool that this isn't a problem anyways.
Attempting to implement requests for block data revealed a problem with
the previous connection logic. Block data is requested by sending a
`getdata` message with hashes of the requested blocks; the peer responds
with a sequence of `block` messages with the blocks themselves.
However, this wasn't possible to handle with the previous connection
logic, which could only convert a single Bitcoin message into a
Response. Instead, we factor out the message handling logic into a
Handler, which can statefully accumulate arbitrary data into a Response
and signal completion. This is still pretty ugly but it does work.
As a side effect, the HeartbeatNonceMismatch error is removed; because
the Handler now tries to process messages until it comes to a Response,
it just ignores mismatched nonces (and will eventually time out).
The previous Mempool and Transaction requests were removed but could be
re-added in a different form later. Also, the `Get` prefixes are
removed from `Request` to tidy the name.
Closes#158.
As discussed on the issue, this makes it possible to safely serialize
data into hashes, and encourages serializable data to make illegal
states unrepresentable.
These are included in the Block, Transaction objects themselves, so the
previous code ended up trying to deserialize two version fields per
object.
Closes#226.
Dimitris Apostolou
teor
Alfredo Garcia
Janito Vaqueiro Ferreira Filho
Preston Evans
Deirdre Connolly
Jack Grigg
Jane Lusby
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Henry de Valence
Jane Lusby
George Tankersley