4fec726c4d352daf2fb4a7e5ed463e44c8815ddb refactor: Simplify Interpret asmap function (Fabian Jahr)
79e97d45c16f043d23ba318a661cc39ec53cf760 doc: Add more extensive docs to asmap implementation (Fabian Jahr)
cf4943fdcdd167a56c278ba094cecb0fa241a8f8 refactor: Use span instead of vector for data in util/asmap (Fabian Jahr)
385c34a05261846dac2b42d47f69b317f534dd40 refactor: Unify asmap version calculation and naming (Fabian Jahr)
fa41fc6a1a7d492b894e206f83e0c9786b44a2f0 refactor: Operate on bytes instead of bits in Asmap code (Fabian Jahr)
Pull request description:
This is a second slice carved out of #28792. It contains the following changes that are crucial for the embedding of asmap data which is added the following PR in the series (probably this will remain in #28792).
The changes are:
- Modernizes and simplifies the asmap code by operating on `std::byte` instead of bits
- Unifies asmap version calculation and naming (previously it was called version and checksum interchangeably)
- Operate on a `span` rather than a vector in the asmap internal to prevent holding the asmap data in memory twice
- Add more extensive documentation to the asmap implementation
- Unify asmap casing in implemetation function names
The first three commits were already part of #28792, the others are new.
The documentation commit came out of feedback gathered at the latest CoreDev. The primary input for the documentation was the documentation that already existed in the Python implementation (`contrib/asmap/asmap.py`) but there are several other comments as well. Please note: I have also asked several LLMs to provide suggestions on how to explain pieces of the implementation and better demonstrate how the parts work together. I have copied bits and pieces that I liked but everything has been edited further by me and obviously all mistakes here are my own.
ACKs for top commit:
hodlinator:
re-ACK 4fec726c4d352daf2fb4a7e5ed463e44c8815ddb
sipa:
ACK 4fec726c4d352daf2fb4a7e5ed463e44c8815ddb
sedited:
Re-ACK 4fec726c4d352daf2fb4a7e5ed463e44c8815ddb
Tree-SHA512: 950a591c3fcc9ddb28fcfdc3164ad3fbd325fa5004533c4a8b670fbf8b956060a0daeedd1fc2fced1f761ac49cd992b79cabe12ef46bc60b2559a7a613d0e166
This prevents holding the asmap data in memory twice.
The version hash changes due to spans being serialized without their size-prefix (unlike vectors).
They are exactly the same, but the descriptor utils should not prescribe
to use the FuzzBufferType. Using a dedicated type for them clarifies
that the utils are not tied to FuzzBufferType.
Also, while touching the lines, use `const` only where it is meaningful.
17cf9ff7efdbab07644fc2f9017fcac1b0757c38 Use cluster size limit for -maxmempool bound, and allow -maxmempool=0 in general (Suhas Daftuar)
315e43e5d86c06b1e51b907f1942cab150205d24 Sanity check `GetFeerateDiagram()` in CTxMemPool::check() (Suhas Daftuar)
de2e9a24c40e1915827506250ed0bbda4009ce83 test: extend package rbf functional test to larger clusters (Suhas Daftuar)
4ef4ddb504e53cb148e8dd713695db37df0e1e4f doc: update policy/packages.md for new package acceptance logic (Suhas Daftuar)
79f73ad713a8d62a6172fbad228cbca848f9ff57 Add check that GetSortedScoreWithTopology() agrees with CompareMiningScoreWithTopology() (Suhas Daftuar)
a86ac117681727b6e72ab50ed751d0d3b0cdff34 Update comments for CTxMemPool class (Suhas Daftuar)
9567eaa66da88a79c54f7a77922d817862122af2 Invoke TxGraph::DoWork() at appropriate times (Suhas Daftuar)
6c5c44f774058bf2a0dfaaadc78347dcb5815f52 test: add functional test for new cluster mempool RPCs (Suhas Daftuar)
72f60c877e001bb8cbcd3a7fb7addfdaba149693 doc: Update mempool_replacements.md to reflect feerate diagram checks (Suhas Daftuar)
21693f031a534193cc7f066a5c6e23db3937bf39 Expose cluster information via rpc (Suhas Daftuar)
72e74e0d42284c712529bf3c619b1b740c070f1b fuzz: try to add more code coverage for mempool fuzzing (Suhas Daftuar)
f107417490ab5b81d3ec139de777a19db87845b6 bench: add more mempool benchmarks (Suhas Daftuar)
7976eb1ae77af2c88e1e61e85d4a61390b34b986 Avoid violating mempool policy limits in tests (Suhas Daftuar)
84de685cf7ee3baf3ca73087e5222411a0504df8 Stop tracking parents/children outside of txgraph (Suhas Daftuar)
88672e205ba1570fc92449b557fd32d836618781 Rewrite GatherClusters to use the txgraph implementation (Suhas Daftuar)
1ca4f01090cfa968c789fafde42054da3263a0e2 Fix miniminer_tests to work with cluster limits (Suhas Daftuar)
1902111e0f20fe6b5c12be019d24691d6b0b8d3e Eliminate CheckPackageLimits, which no longer does anything (Suhas Daftuar)
3a646ec4626441c8c2946598f94199a65d9646d6 Rework RBF and TRUC validation (Suhas Daftuar)
19b8479868e5c854d9268e3647b9488f9b23af0f Make getting parents/children a function of the mempool, not a mempool entry (Suhas Daftuar)
5560913e51af036b5e6907e08cd07488617b12f7 Rework truc_policy to use descendants, not children (Suhas Daftuar)
a4458d6c406215dccb31fd35e0968a65a3269670 Use txgraph to calculate descendants (Suhas Daftuar)
c8b6f70d6492a153b59697d6303fc0515f316f89 Use txgraph to calculate ancestors (Suhas Daftuar)
241a3e666b59abb695c9d0a13d7458a763c2c5a0 Simplify ancestor calculation functions (Suhas Daftuar)
b9cec7f0a1e089cd77bb2fa1c2b54e93442e594c Make removeConflicts private (Suhas Daftuar)
0402e6c7808017bf5c04edb4b68128ede7d1c1e7 Remove unused limits from CalculateMemPoolAncestors (Suhas Daftuar)
08be765ac26a3ae721cb3574d4348602a9982e44 Remove mempool logic designed to maintain ancestor/descendant state (Suhas Daftuar)
fc4e3e6bc12284d3b328c1ad19502294accfe5ad Remove unused members from CTxMemPoolEntry (Suhas Daftuar)
ff3b398d124b9efa49b612dbbb715bbe5d53e727 mempool: eliminate accessors to mempool entry ancestor/descendant cached state (Suhas Daftuar)
b9a2039f51226dce2c4e38ce5f26eefee171744b Eliminate use of cached ancestor data in miniminer_tests and truc_policy (Suhas Daftuar)
ba09fc9774d5a0eaa58d93a2fa20bef1efc74f1e mempool: Remove unused function CalculateDescendantMaximum (Suhas Daftuar)
8e49477e86b3089ea70d1f2659b9fd3a8a1f7db4 wallet: Replace max descendant count with cluster_count (Suhas Daftuar)
e031085fd464b528c186948d3cbf1c08a5a8d624 Eliminate Single-Conflict RBF Carve Out (Suhas Daftuar)
cf3ab8e1d0a2f2bdf72e61e2c2dcb35987e5b9bd Stop enforcing descendant size/count limits (Suhas Daftuar)
89ae38f48965ec0d6c0600ce4269fdc797274161 test: remove rbf carveout test from mempool_limit.py (Suhas Daftuar)
c0bd04d18fdf77a2f20f3c32f8eee4f1d71afd79 Calculate descendant information for mempool RPC output on-the-fly (Suhas Daftuar)
bdcefb8a8b0667539744eae63e9eb5b7dc1c51da Use mempool/txgraph to determine if a tx has descendants (Suhas Daftuar)
69e1eaa6ed22f542ab48da755fa63f7694a15533 Add test case for cluster size limits to TRUC logic (Suhas Daftuar)
9cda64b86c593f0d6ff8f17e483e6566f436b200 Stop enforcing ancestor size/count limits (Suhas Daftuar)
1f93227a84a54397699ca40d889f98913e4d5868 Remove dependency on cached ancestor data in mini-miner (Suhas Daftuar)
9fbe0a4ac26c2fddaa3201cdfd8b69bf1f5ffa01 rpc: Calculate ancestor data from scratch for mempool rpc calls (Suhas Daftuar)
7961496dda2eb24a3f09d661005f06611558a20a Reimplement GetTransactionAncestry() to not rely on cached data (Suhas Daftuar)
feceaa42e8eb43344ced33d94187e93268d45187 Remove CTxMemPool::GetSortedDepthAndScore (Suhas Daftuar)
21b5cea588a7bfe758a8d14efe90046b111db428 Use cluster linearization for transaction relay sort order (Suhas Daftuar)
6445aa7d97551ec5d501d91f6829071c67169122 Remove the ancestor and descendant indices from the mempool (Suhas Daftuar)
216e6937290338950215795291dbf0a533e234cf Implement new RBF logic for cluster mempool (Suhas Daftuar)
ff8f115dec6eb41f739e6e6738dd60becfa168fd policy: Remove CPFP carveout rule (Suhas Daftuar)
c3f1afc934e69a9849625924f72a5886a85eb833 test: rewrite PopulateMempool to not violate mempool policy (cluster size) limits (Suhas Daftuar)
47ab32fdb158069d4422e0f92078603c6df070a6 Select transactions for blocks based on chunk feerate (Suhas Daftuar)
dec138d1ddc79cc3a06e53ed255f0931ce46e684 fuzz: remove comparison between mini_miner block construction and miner (Suhas Daftuar)
6c2bceb200aa7206d44b551d42ad3e70943f1425 bench: rewrite ComplexMemPool to not create oversized clusters (Suhas Daftuar)
1ad4590f63855e856d59616d41a87873315c3a2e Limit mempool size based on chunk feerate (Suhas Daftuar)
b11c89cab210c87ebaf34fbd2a73d28353e8c7bd Rework miner_tests to not require large cluster limit (Suhas Daftuar)
95a8297d481e96d65ac81e4dac72b2ebecb9c765 Check cluster limits when using -walletrejectlongchains (Suhas Daftuar)
95762e6759597d201d685ed6bf6df6eedccf9a00 Do not allow mempool clusters to exceed configured limits (Suhas Daftuar)
edb3e7cdf63688058ad2b90bea0d4933d9967be8 [test] rework/delete feature_rbf tests requiring large clusters (glozow)
435fd5671116b990cf3b875b99036606f921a71d test: update feature_rbf.py replacement test (Suhas Daftuar)
34e32985e811607e7566ae7a6caeacdf8bd8384f Add new (unused) limits for cluster size/count (Suhas Daftuar)
838d7e3553661cb6ba0be32dd872bafb444822d9 Add transactions to txgraph, but without cluster dependencies (Suhas Daftuar)
d5ed9cb3eb52c33c5ac36421bb2da00290be6087 Add accessor for sigops-adjusted weight (Suhas Daftuar)
1bf3b513966e34b45ea359cbe7576383437f5d93 Add sigops adjusted weight calculator (Suhas Daftuar)
c18c68a950d3a17e80ad0bc11ac7ee3de1a87f6c Create a txgraph inside CTxMemPool (Suhas Daftuar)
29a94d5b2f26a4a8b7464894e4db944ea67241b7 Make CTxMemPoolEntry derive from TxGraph::Ref (Suhas Daftuar)
92b0079fe3863b20b71282aa82341d4b6ee4b337 Allow moving CTxMemPoolEntry objects, disallow copying (Suhas Daftuar)
6c73e4744837a7dc138a9177df3a48f30a1ba6c1 mempool: Store iterators into mapTx in mapNextTx (Suhas Daftuar)
51430680ecb722e1d4ee4a26dac5724050f41c9e Allow moving an Epoch::Marker (Suhas Daftuar)
Pull request description:
[Reopening #28676 here as a new PR, because GitHub is slow to load the page making it hard to scroll through and see comments. Also, that PR was originally opened with a prototype implementation which has changed significantly with the introduction of `TxGraph`.]
This is an implementation of the [cluster mempool proposal](https://delvingbitcoin.org/t/an-overview-of-the-cluster-mempool-proposal/393).
This branch implements the following observable behavior changes:
- Maintains a partitioning of the mempool into connected clusters (via the `txgraph` class), which are limited in vsize to 101 kvB by default, and limited in count to 64 by default.
- Each cluster is sorted ("linearized") to try to optimize for selecting highest-feerate-subsets of a cluster first
- Transaction selection for mining is updated to use the cluster linearizations, selecting highest feerate "chunks" first for inclusion in a block template.
- Mempool eviction is updated to use the cluster linearizations, selecting lowest feerate "chunks" first for removal.
- The RBF rules are updated to: (a) drop the requirement that no new inputs are introduced; (b) change the feerate requirement to instead check that the feerate diagram of the mempool will strictly improve; (c) replace the direct conflicts limit with a directly-conflicting-clusters limit.
- The CPFP carveout rule is eliminated (it doesn't make sense in a cluster-limited mempool)
- The ancestor and descendant limits are no longer enforced.
- New cluster count/cluster vsize limits are now enforced instead.
- Transaction relay now uses chunk feerate comparisons to determine the order that newly received transactions are announced to peers.
Additionally, the cached ancestor and descendant data are dropped from the mempool, along with the multi_index indices that were maintained to sort the mempool by ancestor and descendant feerates. For compatibility (eg with wallet behavior or RPCs exposing this), this information is now calculated dynamically instead.
ACKs for top commit:
instagibbs:
reACK 17cf9ff7efdbab07644fc2f9017fcac1b0757c38
glozow:
reACK 17cf9ff7efdbab07644fc2f9017fcac1b0757c38
sipa:
ACK 17cf9ff7efdbab07644fc2f9017fcac1b0757c38
Tree-SHA512: bbde46d913d56f8d9c0426cb0a6c4fa80b01b0a4c2299500769921f886082fb4f51f1694e0ee1bc318c52e1976d7ebed8134a64eda0b8044f3a708c04938eee7
Using std::ranges::copy from the C++ standard library has a few benefits
here:
* It has the additional benefit of being a bit more type safe and
document the byte cast explicitly.
* The compiler will likely optimize it to the same asm, but performance
doesn't really matter here anyway.
* It works around an UB-Sanitizer bug, when the source range is empty.
Fixes https://github.com/bitcoin/bitcoin/issues/33643
0f7d4ee4e8281ed141a6ebb7e0edee7b864e4dcf p2p: Use different inbound inv timer per network (Martin Zumsande)
94db966a3bb52a3677eb5f762447202ed3889f0f net: use generic network key for addrcache (Martin Zumsande)
Pull request description:
Currently, `NextInvToInbounds` schedules each round of `inv` at the same time for all inbound peers. It's being done this way because with a separate timer per peer (like it's done for outbounds), an attacker could do multiple connections to learn about the time a transaction arrived. (#13298).
However, having a single timer for inbounds of all networks is also an obvious fingerprinting vector: Connecting to a suspected pair of privacy-network and clearnet addresses and observing the `inv` pattern makes it trivial to confirm or refute that they are the same node.
This PR changes it such that a separate timer is used for each network.
It uses the existing method from `getaddr` caching and generalizes it to be saved in a new field `m_network_key` in `CNode` which will be used for both `getaddr` caching and `inv` scheduling, and can also be used for any future anti-fingerprinting measures.
ACKs for top commit:
sipa:
utACK 0f7d4ee4e8281ed141a6ebb7e0edee7b864e4dcf
stratospher:
reACK 0f7d4ee.
naiyoma:
Tested ACK 0f7d4ee4e8281ed141a6ebb7e0edee7b864e4dcf
danielabrozzoni:
reACK 0f7d4ee4e8
Tree-SHA512: e197c3005b2522051db432948874320b74c23e01e66988ee1ee11917dac0923f58c1252fa47da24e68b08d7a355d8e5e0a3ccdfa6e4324cb901f21dfa880cd9c
0802398e749c5e16fa7085cd87c91a31bbe043bd fuzz: make it possible to mock (fuzz) CThreadInterrupt (Vasil Dimov)
6d9e5d130d2e1d052044e9a72d44cfffb5d3c771 fuzz: add CConnman::SocketHandler() to the tests (Vasil Dimov)
3265df63a48db187e0d240ce801ee573787fed80 fuzz: add CConnman::InitBinds() to the tests (Vasil Dimov)
91cbf4dbd864b65ba6b107957f087d1d305914b2 fuzz: add CConnman::CreateNodeFromAcceptedSocket() to the tests (Vasil Dimov)
50da7432ec1e5431b243aa30f8a9339f8e8ed97d fuzz: add CConnman::OpenNetworkConnection() to the tests (Vasil Dimov)
e6a917c8f8e0f1a0fa71dc9bbb6e1074f81edea3 fuzz: add Fuzzed NetEventsInterface and use it in connman tests (Vasil Dimov)
e883b37768812d96feec207a37202c7d1b603c1f fuzz: set the output argument of FuzzedSock::Accept() (Vasil Dimov)
Pull request description:
Extend `CConnman` fuzz tests to also exercise the methods `OpenNetworkConnection()`, `CreateNodeFromAcceptedSocket()`, `InitBinds()` and `SocketHandler()`.
Previously fuzzing those methods would have resulted in real socket functions being called in the operating system which is undesirable during fuzzing. Now that https://github.com/bitcoin/bitcoin/pull/21878 is complete all those are mocked to a fuzzed socket and a fuzzed DNS resolver (see how `CreateSock` and `g_dns_lookup` are replaced in the first commit).
ACKs for top commit:
achow101:
ACK 0802398e749c5e16fa7085cd87c91a31bbe043bd
jonatack:
Review re-ACK 0802398e749c5e16fa7085cd87c91a31bbe043bd
dergoegge:
Code review ACK 0802398e749c5e16fa7085cd87c91a31bbe043bd
Tree-SHA512: a717d4e79f42bacf2b029c821fdc265e10e4e5c41af77cd4cb452cc5720ec83c62789d5b3dfafd39a22cc8c0500b18169aa7864d497dded729a32ab863dd6c4d
The generic key can also be used in other places
where behavior between different network identities should
be uncorrelated to avoid fingerprinting.
This also changes RANDOMIZER_ID - since it is not
being persisted to disk, there are no compatibility issues.
* Make the methods of `CThreadInterrupt` virtual and store a pointer to
it in `CConnman`, thus making it possible to override with a mocked
instance.
* Initialize `CConnman::m_interrupt_net` from the constructor, making it
possible for callers to supply mocked version.
* Introduce `FuzzedThreadInterrupt` and `ConsumeThreadInterrupt()` and
use them in `src/test/fuzz/connman.cpp` and `src/test/fuzz/i2p.cpp`.
This improves the CPU utilization of the `connman` fuzz test.
As a nice side effect, the `std::shared_ptr` used for
`CConnman::m_interrupt_net` resolves the possible lifetime issues with
it (see the removed comment for that variable).
`FuzzedSock::Accept()` properly returns a new socket, but it forgot to
set the output argument `addr`, like `accept(2)` is expected to.
This could lead to reading uninitialized data during testing when we
read it, e.g. from `CService::SetSockAddr()` which reads the `sa_family`
member.
Set `addr` to a fuzzed IPv4 or IPv6 address.
32023 changed AddWalletDescriptor to return util::Error, but did not
change all of the failure cases to do so. This may result in some
callers continuing when there was actually an error. Unify all of the
failure cases to use util::Error so that all callers handle
AddWalletDescriptor errors in the same way.
The encapsulated return type is changed from ScriptPubKeyMan* to
std::reference_wrapper<DescriptorScriptPubKeyMan>. This avoids having a
value that can be interpreted as a bool, and also removes the need to
constantly dynamic_cast the returned value. The only kind of
ScriptPubKeyMan that can come out of AddWalletDescriptor is a
DescriptorScriptPubKeyMan anyways.
55b931934a34bab11446e8eed7bdaef92bb056de removed duplicate calling of GetDescriptorScriptPubKeyMan (Saikiran)
Pull request description:
Removed duplicate call to GetDescriptorScriptPubKeyMan and
Instead of checking linearly I have used find method so time complexity reduced significantly for GetDescriptorScriptPubKeyMan
after this fix improved performance of importdescriptor part refs https://github.com/bitcoin/bitcoin/issues/32013.
**Steps to reproduce in testnet environment**
**Input size:** 2 million address in the wallet
**Step1:** call importaddresdescriptor rpc method
observe the time it has taken.
**With the provided fix:**
Do the same steps again
observe the time it has taken.
There is a huge improvement in the performance. (previously it may take 5 to 6 seconds now it will take 1 seconds or less)
main changes i've made during this pr:
1. remove duplicate call to GetDescriptorScriptPubKeyMan method
2. And inside GetDescriptorScriptPubKeyMan method previously we checking **each address linearly** so each time it is calling HasWallet method which has aquired lock.
3. Now i've modified this logic call **find method on the map (O(logn)**) time it is taking, so only once we calling HasWallet method.
**Note:** Smaller inputs in the wallet you may not see the issue but huge wallet size it will definitely impact the performance.
ACKs for top commit:
achow101:
ACK 55b931934a34bab11446e8eed7bdaef92bb056de
w0xlt:
ACK 55b931934a
Tree-SHA512: 4a7fdbcbb4e55bd034e9cf28ab4e7ee3fb1745fc8847adb388c98a19c952a1fb66d7b54f0f28b4c2a75a42473923742b4a99fb26771577183a98e0bcbf87a8ca
Removed duplicate call to GetDescriptorScriptPubKeyMan and
Instead of checking linearly I have used find method so time complexity reduced significantly for GetDescriptorScriptPubKeyMan
after this fix improved performance of importdescriptor part refs #32013.
ConsumeData() will always try to return a name as long as the requested size. It is more useful, and
closer to how `getsockname` would actually behave in reality, to return a random length name
instead.
This was hindering coverage in the PCP fuzz target as the addr len was set to the size of the
sockaddr_in struct and would exhaust all the provided data from the fuzzer.
Thanks to Marco Fleon for suggesting this.
Co-Authored-by: marcofleon <marleo23@proton.me>
The fuzz provider's `ConsumeData` may return less data than necessary
to fill the sockaddr struct and still return success. Fix this to avoid
the caller using uninitialized memory.
This brings the format types closer to the standard library types:
* FormatStringCheck corresponds to std::basic_format_string, with
compile-time checks done via ConstevalFormatString
* RuntimeFormat corresponds to std::runtime_format, with no compile-time
checks done.
Also, it documents where no compile-time checks are done.
552cae243a1bf26bfec03eccd1458f3bf33e01dc fuzz: cover `ASMapHealthCheck` in connman target (brunoerg)
33b0f3ae966ffa50b55489eb867c4d93c0ed3489 fuzz: use `ConsumeNetGroupManager` in connman target (brunoerg)
18c8a0945bda554e121c2a684105dffd55505cd7 fuzz: move `ConsumeNetGroupManager` to util (brunoerg)
fe624631aeb4b5fbad732ad6476c5cd986674b4f fuzz: fuzz `connman` with a non-empty addrman (brunoerg)
0a12cff2a8e54453de1f17e9c0e87e54bbe25a34 fuzz: move `AddrManDeterministic` to util (brunoerg)
Pull request description:
### Motivation
Currently, we fuzz connman with an addrman from `NodeContext`. However,
fuzzing connman with only empty addrman might not be effective, especially
for functions like `GetAddresses` and other ones that plays with addrman. Also,
we do not fuzz connman with ASMap, what would be good for functions that need
`GetGroup`, or even for addrman. Without it, I do not see how effective would be
fuzzing `ASMapHealthCheck`, for example.
### Changes
- Move `AddrManDeterministic` and `ConsumeNetGroupManager` to util.
- Use `ConsumeNetGroupManager` in connman target to construct a netgroupmanager
and use it for `ConnmanTestMsg`.
- Use `AddrManDeterministic` in connman target to create an addrman. It does
not slow down as "filling" the addrman (e.g. with `FillAddrman`).
- Add coverage for `ASMapHealthCheck`.
ACKs for top commit:
maflcko:
review ACK 552cae243a1bf26bfec03eccd1458f3bf33e01dc 🏀
dergoegge:
Code review ACK 552cae243a1bf26bfec03eccd1458f3bf33e01dc
marcofleon:
Code review ACK 552cae243a1bf26bfec03eccd1458f3bf33e01dc. Changes match the PR description.
Tree-SHA512: ba861c839602054077e4bf3649763eeb48357cda83ca3ddd32b02a1b61f4e44a0c5070182f001f9bf531d0d64717876279a7de3ddb9de028b343533b89233851
01960c53c7d71c70792abe19413315768dc2275a fuzz: make FuzzedDataProvider usage deterministic (Martin Leitner-Ankerl)
Pull request description:
There exist many usages of `fuzzed_data_provider` where it is evaluated directly in the function call.
Unfortunately, [the order of evaluation of function arguments is unspecified](https://en.cppreference.com/w/cpp/language/eval_order), and a simple example shows that it can differ e.g. between clang++ and g++: https://godbolt.org/z/jooMezWWY
When the evaluation order is not consistent, the same fuzzing/random input will produce different output, which is bad for coverage/reproducibility. This PR fixes all these cases I have found where unspecified evaluation order could be a problem.
Finding these has been manual work; I grepped the sourcecode for these patterns, and looked at each usage individually. So there is a chance I missed some.
* `fuzzed_data_provider`
* `.Consume`
* `>Consume`
* `.rand`
I first discovered this in https://github.com/bitcoin/bitcoin/pull/29013#discussion_r1420236394. Note that there is a possibility that due to this fix the evaluation order is now different in many cases than when the fuzzing corpus has been created. If that is the case, the fuzzing corpus will have worse coverage than before.
Update: In list-initialization the order of evaluation is well defined, so e.g. usages in `initializer_list` or constructors that use `{...}` is ok.
ACKs for top commit:
achow101:
ACK 01960c53c7d71c70792abe19413315768dc2275a
vasild:
ACK 01960c53c7d71c70792abe19413315768dc2275a
ismaelsadeeq:
ACK 01960c53c7d71c70792abe19413315768dc2275a
Tree-SHA512: e56d087f6f4bf79c90b972a5f0c6908d1784b3cfbb8130b6b450d5ca7d116c5a791df506b869a23bce930b2a6977558e1fb5115bb4e061969cc40f568077a1ad
The script building logic performs a quadratic number of copies in the
number of nested wrappers in the miniscript. Limit the number of nested
wrappers to avoid fuzz timeouts.
Thanks to Marco Falke for reporting the fuzz timeouts and providing a
minimal input to reproduce.
This target may call into logic quadratic over the number of
sub-fragments. Limit the number of sub-fragments to keep the runtime
reasonable.
Thanks to Marco Falke for reporting the fuzz timeouts with a minimized
input.
Problem:
If `FuzzedSock::Recv(N, MSG_PEEK)` is called then `N` bytes would be
retrieved from the fuzz provider, saved in `m_peek_data` and returned
to the caller (ok).
If after this `FuzzedSock::Recv(M, 0)` is called where `M < N`
then the first `M` bytes from `m_peek_data` would be returned
to the caller (ok), but the remaining `N - M` bytes in `m_peek_data`
would be discarded/lost (not ok). They must be returned by a subsequent
`Recv()`.
To resolve this, only remove the head `N` bytes from `m_peek_data`.
Currently, when the FuzzedDataProvider of a FuzzedSock runs out of data,
FuzzedSock::Wait and WaitMany will simulate endless waiting as the
requested events are never simulated as occured.
Fix this by simulating event occurence when ConsumeBool() returns false
(e.g. when the data provider runs out).
Co-authored-by: dergoegge <n.goeggi@gmail.com>
FuzzedSock only supports peeking at one byte at a time, which is not
fuzzer friendly when trying to receive long data.
Fix this by supporting peek data of arbitrary length instead of only one
byte.
In the process of doing so, refactor `ConsumeNetAddr()` to generate the
addresses from IPv4, IPv6, Tor, I2P and CJDNS networks in the same way -
by preparing some random stream and deserializing from it. Similar code
was already found in `RandAddr()`.
There exist many usages of `fuzzed_data_provider` where it is evaluated directly in the function call.
Unfortunately, the order of evaluation of function arguments is unspecified. This means it can differ
between compilers/version/optimization levels etc. But when the evaluation order changes, the same
fuzzing input will produce different output, which is bad for coverage/reproducibility.
This PR fixes all these cases where by moving multiple calls to `fuzzed_data_provider` out of the
function arguments.
