This commit modifies the base peer struct to ascertain when a peer is
able to understand the new witness encoding, and specify the peer’s
supported encoding explicitly before/after the version handshake.
This changes the nonce generated to detect self connections over to use
pseudo randoms instead of a cryptographically random nonce.
There is really not a good reason for it to be cryptographically strong,
using the prng is much faster, and the prng also doesn't burn entropy.
This removes the field that tracks whether the version has been sent
since it is no longer used after the version negotiation was separated
from the main read and write code.
Replace assignments to individual fields of wire.NetAddress with
creating the entire object at once, as one would do if the type was
immutable.
In some places this replaces the creation of a NetAddress with a
high-precision timestamp with a call to a 'constructor' that converts
the timestamp to single second precision. For consistency, the tests
have also been changed to use single-precision timestamps.
Lastly, the number of allocations in readNetAddress have been reduced by
reading the services directly into the NetAddress instead of first into
a temporary variable.
This modifies the error handling path in the peer read loop such that it
will no longer log an error when the error is io.ErrUnexpectedEOF. This
is being done because that error is almost always the result of a peer
being remotely disconnected and thus it isn't useful information to log.
However, since it might actually be due to a malformed message, a reject
message is still queued up to be sent back to the peer (which will
simply be discarded if the peer disconnected) before it is disconnected.
While it would be ideal to only log if it's not due to a disconnect, and
the code already attempts to handle that, it's not 100% possible to
detect upon the read returning an error without attempting to read again
which will not happen until the next loop iteration.
The inability for a peer to negotiate is not something that should be a
warning which implies something is wrong. On the contrary, it is quite
expected that various peers will connect (or be connected to) that are
unable to properly negotiate for a variety of reasons. One example would
be a peer that is too old.
Also, while here take care of a few style nits.
This adds a new field to the peer struct which stores the protocol
version advertised by the remote peer and updates the StatsSnapshot to
return the advertised version instead of the negotiated version.
Older nodes previously added the IP and port information to the address
manager which proved to be unreliable as an inbound connection from a
peer didn't necessarily mean the peer itself accepted inbound
connections.
This also fixes a bug where the peer package was incorrectly sending
the peer's services as its own.
This makes the enforcement of the bloom filter service bit much more
strict. In particular, it does the following:
- Moves the enforcement of the bloom filter service bit out of the peer
package and into the server so the server can ban as necessary
- Disconnect peers that send filter commands when the server is
configured to disable them regardless of the protocol version
- Bans peers that are a high enough protocol version that they are
supposed to observe the service bit is disabled, but ignore it and
send filter commands regardless.
As an added bonus, this fixes the old logic which had a bug in that it
was examining the *remote* peer's supported services in order to choose
whether or not to disconnect instead of the *local* server's supported
services.
This is mostly a backport of some of the same modifications made in
Decred along with a few additional things cleaned up. In particular,
this updates the code to make use of the new chainhash package.
Also, since this required API changes anyways and the hash algorithm is
no longer tied specifically to SHA, all other functions throughout the
code base which had "Sha" in their name have been changed to Hash so
they are not incorrectly implying the hash algorithm.
The following is an overview of the changes:
- Remove the wire.ShaHash type
- Update all references to wire.ShaHash to the new chainhash.Hash type
- Rename the following functions and update all references:
- wire.BlockHeader.BlockSha -> BlockHash
- wire.MsgBlock.BlockSha -> BlockHash
- wire.MsgBlock.TxShas -> TxHashes
- wire.MsgTx.TxSha -> TxHash
- blockchain.ShaHashToBig -> HashToBig
- peer.ShaFunc -> peer.HashFunc
- Rename all variables that included sha in their name to include hash
instead
- Update for function name changes in other dependent packages such as
btcutil
- Update copyright dates on all modified files
- Update glide.lock file to use the required version of btcutil
The --blocksonly configuration option disables accepting transactions
from remote peers. It will still accept, relay, and rebroadcast
valid transactions sent via RPC or websockets.
This modifies the peer package to add support for the sendheaders
protocol message introduced by BIP0030.
NOTE: This does not add support to btcd itself. That requires the server
and sync code to make use of the new functionality exposed by these
changes. As a result, btcd will still be using protocol version 70011.
This ensures the channel passed to QueueMessage is writable and that
QueueMessage will not read from the channel (write-only).
This change is merely a safety change. If a user of the API passes
a read-only channel to QueueMessage, it will now be caught at compile
time instead of panicking during runtime.
Also update internal functions.
This commit does not change functionality. It makes the creation of inbound and outbound peers more homogeneous. As a result the Start method of peer was removed as it was found not to be necessary. This is the first of several pull requests/commits designed to make the peer public API and internals less complex.
This implementation ensures that all addresses have an equal chance of
being included in the addr message. It also moves the pseudorandom number
generator seeding to package level so that it can be overridden for
testing if required.
The getaddr msg is usually replied to with an addr msg, but if
the other peer does not have any addresses to share it will not
reply at all (instead of replying with an addr msg with 0 addresses).
Therefore, the getaddr msg is not guaranteed a reply, so this commit
removes it from stall detection to avoid incorrectly kicking
such peers.
In case of an error during protocol negotiation in handleVersionMsg,
immediately break out and prevent further processing of OnVersion
listener which generally depends upon peer attributes like NA to be set
during the negotiation. Fixes#579.
This defines the peer stat fields directly in the Peer struct instead of
defining them in a separate struct and embedding them. It is slightly
more efficient this way and there is really no reason to have them
defined separately anyways since they are not passed around or otherwise
used independently.
This commit modifies the peer logging so that it will not log an error
when it's due to the remote peer disconnecting or the peer being
forcibly disconnected or shutdown.
This commit implements stall detection logic at the peer level to detect
and disconnect peers that are either not following the protocol in
regards to expected response messages or have otherwise stalled. This
is accomplished by setting deadlines for each message type which expects
a response and periodically checking them while properly taking into
account processing time.
There are an increasing number of nodes on the network which claim to be
full nodes, but don't actually properly implement the entire p2p
protocol even though they implement it enough to cause properly
implemented nodes to make data requests to which they never respond.
Since btcd currently only syncs new blocks via single sync peer and,
prior to this commit only had very basic stall detection, this could
lead to a situation where the block download became stalled indefinitely
due to one of these misbehaving peers. This commit fixes that issue
since the stalled peer will now be detected and disconnected which leads
to a new sync peer being selected.
This logic will also fit nicely with the future multi-peer sync model
which is on the roadmap and for which infrastructure work is underway.
Fixes#486 and fixes#229.
This commit modifies the ping logic in the peer to ping on an interval
regardless of what other messages are being sent versus the previous
method of delaying the ping each time a message that is expected to
receive data is sent.
This helps improve the ping statistics and simplifies its logic.
This fleshes out the doc.go documentation which is shown on godoc, the
README.md shown on github, and improves a couple of comments for the
fields in the Config struct.
This commit introduces package peer which contains peer related features
refactored from peer.go.
The following is an overview of the features the package provides:
- Provides a basic concurrent safe bitcoin peer for handling bitcoin
communications via the peer-to-peer protocol
- Full duplex reading and writing of bitcoin protocol messages
- Automatic handling of the initial handshake process including protocol
version negotiation
- Automatic periodic keep-alive pinging and pong responses
- Asynchronous message queueing of outbound messages with optional
channel for notification when the message is actually sent
- Inventory message batching and send trickling with known inventory
detection and avoidance
- Ability to wait for shutdown/disconnect
- Flexible peer configuration
- Caller is responsible for creating outgoing connections and listening
for incoming connections so they have flexibility to establish
connections as they see fit (proxies, etc.)
- User agent name and version
- Bitcoin network
- Service support signalling (full nodes, bloom filters, etc.)
- Maximum supported protocol version
- Ability to register callbacks for handling bitcoin protocol messages
- Proper handling of bloom filter related commands when the caller does
not specify the related flag to signal support
- Disconnects the peer when the protocol version is high enough
- Does not invoke the related callbacks for older protocol versions
- Snapshottable peer statistics such as the total number of bytes read
and written, the remote address, user agent, and negotiated protocol
version
- Helper functions for pushing addresses, getblocks, getheaders, and
reject messages
- These could all be sent manually via the standard message output
function, but the helpers provide additional nice functionality such
as duplicate filtering and address randomization
- Full documentation with example usage
- Test coverage
In addition to the addition of the new package, btcd has been refactored
to make use of the new package by extending the basic peer it provides to
work with the blockmanager and server to act as a full node. The
following is a broad overview of the changes to integrate the package:
- The server is responsible for all connection management including
persistent peers and banning
- Callbacks for all messages that are required to implement a full node
are registered
- Logic necessary to serve data and behave as a full node is now in the
callback registered with the peer
Finally, the following peer-related things have been improved as a part
of this refactor:
- Don't log or send reject message due to peer disconnects
- Remove trace logs that aren't particularly helpful
- Finish an old TODO to switch the queue WaitGroup over to a channel
- Improve various comments and fix some code consistency cases
- Improve a few logging bits
- Implement a most-recently-used nonce tracking for detecting self
connections and generate a unique nonce for each peer
