01e283068b [net] Remove unnecessary default args on CNode constructor (Amiti Uttarwar)
bc5d65b3ca [refactor] Remove IsOutboundDisconnectionCandidate (Amiti Uttarwar)
2f2e13b6c2 [net/refactor] Simplify multiple-connection checks (Amiti Uttarwar)
7f7b83deb2 [net/refactor] Rework ThreadOpenConnections logic (Amiti Uttarwar)
35839e963b [net] Fix bug where AddrFetch connections would be counted as outbound full relay (Amiti Uttarwar)
4972c21b67 [net/refactor] Clarify logic for selecting connections in ThreadOpenConnections (Amiti Uttarwar)
60156f5fc4 [net/refactor] Remove fInbound flag from CNode (Amiti Uttarwar)
7b322df629 [net/refactor] Remove m_addr_fetch member var from CNode (Amiti Uttarwar)
14923422b0 [net/refactor] Remove fFeeler flag from CNode (Amiti Uttarwar)
49efac5cae [net/refactor] Remove m_manual_connection flag from CNode (Amiti Uttarwar)
d3698b5ee3 [net/refactor] Add connection type as a member var to CNode (Amiti Uttarwar)
46578c03e9 [doc] Describe different connection types (Amiti Uttarwar)
442abae2ba [net/refactor] Add AddrFetch connections to ConnectionType enum (Amiti Uttarwar)
af59feb052 [net/refactor] Extract m_addr_known logic from initializer list (Amiti Uttarwar)
e1bc29812d [net/refactor] Add block relay only connections to ConnectionType enum (Amiti Uttarwar)
0e52a659a2 [net/refactor] Add feeler connections to ConnectionType enum (Amiti Uttarwar)
1521c47438 [net/refactor] Add manual connections to ConnectionType enum (Amiti Uttarwar)
26304b4100 [net/refactor] Introduce an enum to distinguish type of connection (Amiti Uttarwar)
3f1b7140e9 scripted-diff: Rename OneShot to AddrFetch (Amiti Uttarwar)
Pull request description:
**This is part 1 of #19315, which enables the ability to test `outbound` and `block-relay-only` connections from the functional tests.** Please see that PR for more information of overall functionality.
**This PR simplifies how we manage different connection types.** It introduces an enum with the various types of connections so we can explicitly define the connection type. The existing system relies on a series of independent flags, then has asserts scattered around to ensure that conflicting flags are not enabled at the same time. I find this approach to be both brittle and confusing. While making these changes, I found a small bug due to the silent assumptions.
This PR also proposes a rename from `OneShot` to `AddrFetch`. I find the name `OneShot` to be very confusing, especially when we also have `onetry` manual connections. Everyone I've talked to offline has agreed that the name is confusing, so I propose a potential alternative. I think this is a good opportunity for a rename since I'm creating an enum to explicitly define the connection types.
(some context for the unfamiliar: `oneshot` or `addrfetch` connections are short-lived connections created on startup. They connect to the seed peers, send a `getaddr` to solicit addresses, then close the connection.)
Overview of this PR:
* rename `oneshot` to `addrfetch`
* introduce `ConnectionType` enum
* one by one, add different connection types to the enum
* expose the `conn_type` on CNode, and use this to reduce reliance on flags (& asserts)
* fix the bug in counting different type of connections
* some additional cleanup to simplify logic and make expectations explicit/inclusive rather than implicit/exclusive.
ACKs for top commit:
jnewbery:
utACK 01e283068b
laanwj:
Code review ACK 01e283068b, the commits are pretty straightforward to follow, and I think this is a move in the right direction overall
vasild:
ACK 01e283068
sdaftuar:
ACK 01e283068b.
fanquake:
ACK 01e283068b - I don't have as much experience with the networking code but these changes look fairly straight forward, the new code seems more robust/understandable and the additional documentation is great. I'm glad that a followup branch is already underway. There might be some more review comments here later today, so keep an eye on the discussion, however I'm going to merge this now.
jb55:
wow this code was messy before... ACK 01e283068b
Tree-SHA512: 7bb644a6ed5849913d777ebc2ff89133ca0fbef680355a9a344e07496a979e6f9ff21a958e8eea93dcd7d5c343682b0c7174b1a3de380a4247eaae73da436e15
4c0731f9c5 Deduplicate missing parents of orphan transactions (Suhas Daftuar)
8196176243 Rewrite parent txid loop of requested transactions (Suhas Daftuar)
Pull request description:
I noticed a couple of places recently where we loop over all inputs of a transaction in order to do some processing on the txids we find in those inputs. There may be thousands of inputs in a transaction, and the same txid may appear many times. In a couple of places in particular, we loop over those txids and add them to a rolling bloom filter; doing that multiple times for the same txid wastes entries in that filter.
This PR fixes that in two places relating to transaction relay: one on the server side, where we look for parent transactions of a tx that we are delivering to a peer to ensure that getdata requests for those parents will succeed; and the other on the client side, where when we process an orphan tx we want to loop over the parent txids and ensure that all are eventually requested from the peer who provided the orphan.
This addresses a couple of [related](https://github.com/bitcoin/bitcoin/pull/19109#discussion_r455197217) [comments](https://github.com/bitcoin/bitcoin/pull/19109#discussion_r456820373) left in #19109.
ACKs for top commit:
laanwj:
Code review ACK 4c0731f9c5
jonatack:
ACK 4c0731f9c5
ajtowns:
ACK 4c0731f9c5
Tree-SHA512: 8af9df7f56c6e54b5915519d7d5465e081473ceb1bcc89bbebf83e78722cf51ff58145e588cf57126bce17071a8053273f4bcef0ad8166bec83ba14352e40f5d
Extract logic that check multiple connection types into interface functions &
structure as switch statements. This makes it very clear what touch points are
for accessing `m_conn_type` & using the switch statements enables the compiler
to warn if a new connection type is introduced but not handled for these cases.
9f88ded82b test addition of unknown segwit spends to txid reject filter (Gregory Sanders)
7989901c7e Add txids with non-standard inputs to reject filter (Suhas Daftuar)
Pull request description:
Our policy checks for non-standard inputs depend only on the non-witness
portion of a transaction: we look up the scriptPubKey of the input being
spent from our UTXO set (which is covered by the input txid), and the p2sh
checks only rely on the scriptSig portion of the input.
Consequently it's safe to add txids of transactions that fail these checks to
the reject filter, as the witness is irrelevant to the failure. This is helpful
for any situation where we might request the transaction again via txid (either
from txid-relay peers, or if we might fetch the transaction via txid due to
parent-fetching of orphans).
Further, in preparation for future witness versions being deployed on the
network, ensure that WITNESS_UNKNOWN transactions are rejected in
AreInputsStandard(), so that transactions spending v1 (or greater) witness
outputs will fall into this category of having their txid added to the reject
filter.
ACKs for top commit:
ajtowns:
ACK 9f88ded82b - code review
jnewbery:
Code review ACK 9f88ded82b
ariard:
Code Review/Tested ACK 9f88ded
naumenkogs:
utACK 9f88ded82b
jonatack:
ACK 9f88ded82b
Tree-SHA512: 1e93c0a5b68cb432524780ffc0093db893911fdfed9e2ed17f888e59114cc75d2a07062aefad4e5ce2e87c9270886117a8abb3c78fb889c9b9f31967f1777148
In the logic for requesting missing parents of orphan transactions, parent
transactions with multiple outputs being spent by the given orphan were being
processed multiple times. Fix this by deduplicating the set of missing parent
txids first.
Co-authored-by: Anthony Towns <aj@erisian.com.au>
Previously, we would potentially add the same txid many times to the rolling
bloom filter of recently announced transactions to a peer, if many outputs of
the same txid appeared as inputs in a transaction. Eliminate this problem and
avoid redundant lookups by asking the mempool for the unique parents of a
requested transaction.
Our policy checks for non-standard inputs depend only on the non-witness
portion of a transaction: we look up the scriptPubKey of the input being
spent from our UTXO set (which is covered by the input txid), and the p2sh
checks only rely on the scriptSig portion of the input.
Consequently it's safe to add txids of transactions that fail these checks to
the reject filter, as the witness is irrelevant to the failure. This is helpful
for any situation where we might request the transaction again via txid (either
from txid-relay peers, or if we might fetch the transaction via txid due to
parent-fetching of orphans).
Further, in preparation for future witness versions being deployed on the
network, ensure that WITNESS_UNKNOWN transactions are rejected in
AreInputsStandard(), so that transactions spending v1 (or greater) witness
outputs will fall into this category of having their txid added to the reject
filter.
3bd67ba5a4 Test addr response caching (Gleb Naumenko)
cf1569e074 Add addr permission flag enabling non-cached addr sharing (Gleb Naumenko)
acd6135b43 Cache responses to addr requests (Gleb Naumenko)
7cc0e8101f Remove useless 2500 limit on AddrMan queries (Gleb Naumenko)
ded742bc5b Move filtering banned addrs inside GetAddresses() (Gleb Naumenko)
Pull request description:
This is a very simple code change with a big p2p privacy benefit.
It’s currently trivial to scrape any reachable node’s AddrMan (a database of all nodes known to them along with the timestamps).
We do have a limit of one GETADDR per connection, but a spy can disconnect and reconnect even from the same IP, and send GETADDR again and again.
Since we respond with 1,000 random records at most, depending on the AddrMan size it takes probably up to 100 requests for an spy to make sure they scraped (almost) everything.
I even have a script for that. It is totally doable within couple minutes.
Then, with some extra protocol knowledge a spy can infer the direct peers of the victim, and other topological stuff.
I suggest to cache responses to GETADDR on a daily basis, so that an attacker gets at most 1,000 records per day, and can’t track the changes in real time. I will be following up with more improvements to addr relay privacy, but this one alone is a very effective. And simple!
I doubt any of the real software does *reconnect to get new addrs from a given peer*, so we shouldn’t be cutting anyone.
I also believe it doesn’t have any negative implications on the overall topology quality. And the records being “outdated” for at most a day doesn’t break any honest assumptions either.
ACKs for top commit:
jnewbery:
reACK 3bd67ba5a4
promag:
Code review ACK 3bd67ba5a4.
ariard:
Code Review ACK 3bd67ba
Tree-SHA512: dfa5d03205c2424e40a3f8a41af9306227e1ca18beead3b3dda44aa2a082175bb1c6d929dbc7ea8e48e01aed0d50f0d54491caa1147471a2b72a46c3ca06b66f
c251d710a4 p2p, refactoring: use CInv helpers in net_processing.cpp (Jon Atack)
4254cd9f8f p2p: add CInv transaction message helper methods (Jon Atack)
Pull request description:
Following the merge of wtxid relay in #18044, this is the first of three refactoring PRs (this one, #19610, and #19611) with no change in behavior, tightly scoped to ease review, to simplify the net processing code and improve encapsulation:
- add `CInv` transaction message helper methods, defined in the class
- use the new helpers in `net_processing.cpp` to simplify the code and improve encapsulation
Test coverage is provided by the functional p2p tests, notably (from seeing which tests failed when breaking things to test coverage) `p2p_segwit`, `p2p_tx_download`, `p2p_feefilter`, and `p2p_permissions`.
ACKs for top commit:
fjahr:
Code review ACK c251d710a4
laanwj:
Code review ACK c251d710a4
vasild:
ACK c251d71
theStack:
Code-Review ACK c251d710a4
hebasto:
ACK c251d710a4, I have reviewed the code and it looks OK, I agree it can be merged.
Tree-SHA512: ead034b3c9e438909b4c5010c570d7930e69063c114290b051b7cebfd9bd5b19f573218bebe8a521256d32e830797f997adad3d85b4539c64ac5762b698e656d
- Make const things const.
- Replace conditional return with assert.
- Don't log the peer's IP address.
- Log the name Misbehaving directly instead of relying on __func__.
Misbehaving() could optionally take a debug string for printing to the
log file. Make this mandatory and always provide the string.
A couple of additional minor changes:
- remove the unnecessary forward declaration of Misbehaving()
- don't include the nodeid or newline in the passed debug message.
Misbehaving() adds these itself.
655b195747 [net processing] Continue SendMessages processing if not disconnecting peer (John Newbery)
a49781e56d [net processing] Only call MaybeDiscourageAndDisconnect from SendMessages (John Newbery)
a1d5a428a2 [net processing] Fix bad indentation in SendMessages() (John Newbery)
1a1c23f8d4 [net processing] Change cs_main TRY_LOCK to LOCK in SendMessages() (John Newbery)
Pull request description:
The motivation for this PR is to reduce the scope of cs_main locking in misbehavior logic. It is the first set of commits from a larger branch to move the misbehavior data out of CNodeState and into a new struct that doesn't take cs_main.
There are some very minor behavior changes in this branch, such as:
- Not checking for discouragement/disconnect in `ProcessMessages()` (and instead relying on the following check in `SendMessages()`)
- Checking for discouragement/disconnect as the first action in `SendMessages()` (and not doing ping message sending first)
- Continuing through `SendMessages()` if `MaybeDiscourageAndDisconnect()` doesn't disconnect the peer (rather than dropping out of `SendMessages()`
ACKs for top commit:
jonatack:
re-ACK 655b195 per `git range-diff 505b4ed f54af5e 655b195`, code/commit messages review, a bit of code history, and debug build.
MarcoFalke:
ACK 655b195747 only some style-nits 🚁
promag:
Code review ACK 655b195747.
ariard:
Code Review ACK 655b195
Tree-SHA512: fd6d7bc6bb789f5fb7771fb6a45f61a8faba32af93b766554f562144f9631d15c9cc849a383e71743ef73e610b4ee14853666f6fbf08a3ae35176d48c76c65d3
Previously, TX_WITNESS_MUTATED could be returned during transaction validation
for either transactions that had a witness that was non-standard, or for
transactions that had no witness but were invalid due to segwit validation
rules.
However, for txid/wtxid-relay considerations, net_processing distinguishes the
witness stripped case separately, because it affects whether a wtxid should be
able to be added to the reject filter. It is safe to add the wtxid of a
witness-mutated transaction to the filter (as that wtxid shouldn't collide with
the txid, and hence it wouldn't interfere with transaction relay from
txid-relay peers), but it is not safe to add the wtxid (== txid) of a
witness-stripped transaction to the filter, because that would interfere with
relay of another transaction with the same txid (but different wtxid) when
relaying from txid-relay peers.
Also updates the comment explaining this logic, and explaining that we can get
rid of this complexity once there's a sufficient deployment of wtxid-relaying
peers on the network.
Using both txid and wtxid-based relay with peers means that we could sometimes
download the same transaction twice, if announced via two different hashes from
different peers.
Use a heuristic of delaying txid-peer-getdata requests by 2 seconds, if we have
at least one wtxid-based peer.
This adds a field to CNodeState that tracks whether to relay transactions with
that peer via wtxid, instead of txid. As of this commit the field will always
be false, but in a later commit we will add a way to negotiate turning this on
via p2p messages exchanged with the peer.
Previously, we only added txids to recentRejects if we were sure that the
transaction couldn't have had the wrong witness (either because the witness was
malleated or stripped).
In preparation for wtxid-based relay, we can observe that txid == wtxid for
transactions that have no witness, and add the wtxid of rejected transactions,
provided the transaction wasn't a witness-stripped one. This means that we now
add more data to the filter (as prior to this commit, any transaction with a
witness that failed to be accepted was being skipped for inclusion in the
filter) but witness malleation should still not interfere with relay of a valid
segwit transaction, because the txid of a segwit transaction would not be added
to the filter after failing validation.
In the future, having wtxids in the recent rejects filter will allow us to
skip downloading the same wtxid multiple times, once our peers use wtxids for
transaction relay.
This is in preparation for wtxid-based invs (we need to be able to tell whether
we AlreadyHave() a transaction based on either txid or wtxid).
This also double the size of the bloom filter, which is overkill, but still
uses a manageable amount of memory.
0c8461a88e refactor: replace CConnman pointers by references in net_processing.cpp (Sebastian Falbesoner)
Pull request description:
This is a follow-up to the recently merged PR https://github.com/bitcoin/bitcoin/pull/19053, replacing ~~two more types of~~ one more type of pointer (CConnman) by references to increase the code quality -- pointers should either check for `nullptr` or be replaced by references, and the latter strategy seems to be more reasonable.
Again, to keep the review burden managable, the changes are kept simple,
* only tackling `CConnman*` ~~and `BanMan*`~~ pointers
* only within the net_processing module, i.e. no changes that would need adaption in other modules
* keeping the names of the variables as they are
ACKs for top commit:
jnewbery:
utACK 0c8461a88e
MarcoFalke:
ACK 0c8461a88e🕧
Tree-SHA512: 79dc05144bcfb5e0bbc62180285aadcc6199f044fa3016c0f54f7b7f45037415260970037bd63b18fafefb8aef448549dae14b780bafb540fa2373f493a17f71
fa9f20b647 log: Properly log txs rejected from mempool (MarcoFalke)
Pull request description:
Currently `CheckTxInputs` rejections from the mempool are the only rejections that log directly and unconditionally to debug.log instead of leaving it to the caller. This has multiple issues:
* A rejected RPC transaction will log a redundant failure reason to debug log. All other failures are merely reported to the RPC user.
* A rejected p2p transaction will log the failure twice. Once with the `MEMPOOLREJ` flag, and once unconditionally.
* A rejected orphan transaction will log no failure.
Fix all issues by simply returning the state to the caller, like it is done for all other rejections.
The patch includes whitespace fixups to highlight relevant parts of the codebase and simplify review.
ACKs for top commit:
naumenkogs:
utACK fa9f20b647
rajarshimaitra:
Concept ACK. Compiled and ran tests. `fa9f20b`
jnewbery:
code review ACK fa9f20b647
Tree-SHA512: 86cc17b2a9239c01c4fc3f254ad48ee1d3883266966b9811030176338b9ac3deaea7ea5babfb8bbf739d7440154e30011fede8f9313175f199d4a062af6494f7
Although we currently don't do this, it should be possible to create a
CConnman or PeerLogicValidation without a Banman instance. Therefore
always check that banman exists before dereferencing the pointer.
Also add comments to the m_banman members of CConnman and
PeerLogicValidation to document that these may be nullptr.
f32c408f3a Make sure unconfirmed parents are requestable (Pieter Wuille)
c4626bcd21 Drop setInventoryTxToSend based filtering (Pieter Wuille)
43f02ccbff Only respond to requests for recently announced transactions (Pieter Wuille)
b24a17f039 Introduce constant for mempool-based relay separate from mapRelay caching (Pieter Wuille)
a9bc563803 Swap relay pool and mempool lookup (Pieter Wuille)
Pull request description:
This implements the follow-up suggested here: https://github.com/bitcoin/bitcoin/pull/18861#issuecomment-627630111 . Instead of checking `setInventoryTxToSend`, maintain an explicit bloom filter with the 3500 most recently announced invs, and permit fetching any of these as long as they're in the relay pool or the mempool. In addition, permit relay from the mempool after just 2 minutes instead of 15.
This:
* Fixes the brief opportunity an attacker has to request unannounced invs just after the connection is established (pointed out by naumenkogs, see https://github.com/bitcoin/bitcoin/pull/18861#issuecomment-627627010).
* Guarantees that locally resubmitted invs after `filterInventoryKnown` rolls over can still be requested (pointed out by luke-jr, see https://github.com/bitcoin/bitcoin/pull/18861#discussion_r419695831).
It adds 37 KiB of filter per peer.
This is also a step towards dropping the relay pool entirely and always relaying from the mempool directly (see #17303), but that is still blocked by dealing properly with NOTFOUNDs (see #18238).
ACKs for top commit:
jnewbery:
reACK f32c408f3
jonatack:
re-ACK f32c408 per `git range-diff f7c19e8 2da7ee3 f32c408` and redid the following: code review, thought about motivation, DoS and privacy aspects, debug build to check for warnings after updating Clang from 6 to 11 since last review.
ajtowns:
re-ACK f32c408f3a
Tree-SHA512: aa05b9fd01bad59581c4ec91836a52d7415dc933fa49d4c4adced79aa25aaad51e11166357e8c8b29fbf6021a7401b98c21b850b5d8e8ad773fdb5d6608e1e85
