Remove the forest of special exceptions, and simply log a short
message to the NET logging category when an exception happens during
packet processing. It is not good to panick end users with errors
that any peer can generate (let alone writing to stderr).
Github-Pull: #17762
Rebased-From: 4d88c3dcb61e7c075ed3dd442044e0eff4e3c8de
0c62e3aa73 New regression testing for CVE-2018-17144, CVE-2012-2459, and CVE-2010-5137. (lucash-dev)
38bfca6bb2 Added comments referencing multiple CVEs in tests and production code. (lucash-dev)
Pull request description:
This functional test includes two scenarios that test for regressions of vulnerabilities, but they are only briefly described. There are freely available documents explaining in detail the issues, but without explicit mentions, the developer trying to maintain the code needs an additional step of digging in commit history and PR conversations to figure it out.
Added comments to explicitly mention CVE-2018-17144 and CVE-2012-2459, for more complete documentation.
This improves developer experience by making understanding the tests easier.
ACKs for top commit:
laanwj:
ACK 0c62e3aa73, checked the CVE numbers, thanks for adding documentation
Tree-SHA512: 3ee05351745193b8b959e4a25d50f25a693b2d24b0732ed53cf7d5882df40b5dd0f1877bd5c69cffb921d4a7acf9deb3cc1160b96dc730d9b5984151ad06b7c9
Recent questions have come up regarding dynamic service registration
(see https://github.com/bitcoin/bitcoin/pull/16442#discussion_r308702676
and the assumeutxo project, which needs to dynamically flip NODE_NETWORK).
While investigating how dynamic service registration might work, I was
confused about how we convey local services to peers. This adds some
documentation that hopefully clarifies this process.
0ba08020c9 Disconnect peers violating blocks-only mode (Suhas Daftuar)
937eba91e1 doc: improve comments relating to block-relay-only peers (Suhas Daftuar)
430f489027 Don't relay addr messages to block-relay-only peers (Suhas Daftuar)
3a5e885306 Add 2 outbound block-relay-only connections (Suhas Daftuar)
b83f51a4bb Add comment explaining intended use of m_tx_relay (Suhas Daftuar)
e75c39cd42 Check that tx_relay is initialized before access (Suhas Daftuar)
c4aa2ba822 [refactor] Change tx_relay structure to be unique_ptr (Suhas Daftuar)
4de0dbac9b [refactor] Move tx relay state to separate structure (Suhas Daftuar)
26a93bce29 Remove unused variable (Suhas Daftuar)
Pull request description:
Transaction relay is optimized for a combination of redundancy/robustness as well as bandwidth minimization -- as a result transaction relay leaks information that adversaries can use to infer the network topology.
Network topology is better kept private for (at least) two reasons:
(a) Knowledge of the network graph can make it easier to find the source IP of a given transaction.
(b) Knowledge of the network graph could be used to split a target node or nodes from the honest network (eg by knowing which peers to attack in order to achieve a network split).
We can eliminate the risks of (b) by separating block relay from transaction relay; inferring network connectivity from the relay of blocks/block headers is much more expensive for an adversary.
After this commit, bitcoind will make 2 additional outbound connections that are only used for block relay. (In the future, we might consider rotating our transaction-relay peers to help limit the effects of (a).)
ACKs for top commit:
sipa:
ACK 0ba08020c9
ajtowns:
ACK 0ba08020c9 -- code review, ran tests. ran it on mainnet for a couple of days with MAX_BLOCKS_ONLY_CONNECTIONS upped from 2 to 16 and didn't observe any unexpected behaviour: it disconnected a couple of peers that tried sending inv's, and it successfully did compact block relay with some block relay peers.
TheBlueMatt:
re-utACK 0ba08020c9. Pointed out that stats.fRelayTxes was sometimes uninitialized for blocksonly peers (though its not a big deal and only effects RPC), which has since been fixed here. Otherwise changes are pretty trivial so looks good.
jnewbery:
utACK 0ba08020c9
jamesob:
ACK 0ba08020c9
Tree-SHA512: 4c3629434472c7dd4125253417b1be41967a508c3cfec8af5a34cad685464fbebbb6558f0f8f5c0d4463e3ffa4fa3aabd58247692cb9ab8395f4993078b9bcdf
If we set fRelay=false in our VERSION message, and a peer sends an INV or TX
message anyway, disconnect. Since we use fRelay=false to minimize bandwidth,
we should not tolerate remaining connected to a peer violating the protocol.
Transaction relay is primarily optimized for balancing redundancy/robustness
with bandwidth minimization -- as a result transaction relay leaks information
that adversaries can use to infer the network topology.
Network topology is better kept private for (at least) two reasons:
(a) Knowledge of the network graph can make it easier to find the source IP of
a given transaction.
(b) Knowledge of the network graph could be used to split a target node or
nodes from the honest network (eg by knowing which peers to attack in order to
achieve a network split).
We can eliminate the risks of (b) by separating block relay from transaction
relay; inferring network connectivity from the relay of blocks/block headers is
much more expensive for an adversary.
After this commit, bitcoind will make 2 additional outbound connections that
are only used for block relay. (In the future, we might consider rotating our
transaction-relay peers to help limit the effects of (a).)
582d2cd747 Cover UTXO set access with lock annotations (James O'Beirne)
5693530685 refactor: have CCoins* data managed under CChainState (James O'Beirne)
fae6ab6aed refactor: pcoinsTip -> CChainState::CoinsTip() (James O'Beirne)
Pull request description:
This is part of the [assumeutxo project](https://github.com/bitcoin/bitcoin/projects/11):
Parent PR: #15606
Issue: #15605
Specification: https://github.com/jamesob/assumeutxo-docs/tree/2019-04-proposal/proposal
---
This change encapsulates UTXO set data within CChainState instances, removing global data `pcoinsTip` and `pcoinsviewdb`. This is necessary if we want to maintain multiple chainstates with their own rendering of the UTXO set.
We introduce a class CoinsViews which consolidates the construction of a CCoins* hierarchy.
This commit could be broken into smaller pieces, but it would require more ephemeral diffs to, e.g., temporarily change CCoinsViewDB's constructor invocations.
ACKs for top commit:
Sjors:
reACK 582d2cd747
MarcoFalke:
ACK 582d2cd747
Tree-SHA512: ec9d904fe5dca8cd2dc4b7916daa5d8bab30856dd4645987300f905e0a19f9919fce4f9d1ff03eda982943ca73e6e9a746be6cf53b46510de36e8c81a1eafba1
fab3658356 [qa] Test that getdata requests work as expected (Suhas Daftuar)
fa883ab35a net: Use mockable time for tx download (MarcoFalke)
Pull request description:
Two commits:
* First commit changes to mockable time for tx download (refactoring, should only have an effect on regtest)
* Second commit adds a test that uses mocktime to test tx download
ACKs for top commit:
laanwj:
code review ACK 16197/commits/fab365835639a3da03f8ad9a58a0db6c6c4c2314
jamesob:
ACK fab3658356
Tree-SHA512: 3a64a3e283ec4bab1f6e506404b11f0a564a5b61d2a7508ae738a61f035e57220484c66e0ae47d847fe9f7e3ff5cc834909d7b34a9bbcea6abe01f8742806908
dddd9270f8 net: Document what happens to getdata of unknonw type (MarcoFalke)
Pull request description:
Any getdata of unknown type will never be processed and blocks all future messages from a peer. This isn't obviously clear from reading the code, so document it.
Top commit has no ACKs.
Tree-SHA512: 4f8e43bbe6534242facfcfffae28b7a6aa2d228841fa2146a87d494e69f614b0da23cf7a5f3d4367358a7c1981fe2ec196a21c437ae1653f1c7e0351be22598a
0959d37e3e Don't use global (external) symbols for symbols that are used in only one translation unit (practicalswift)
Pull request description:
Don't use global (external) symbols for symbols that are used in only one translation unit.
Before:
```
$ for SYMBOL in $(nm src/bitcoind | grep -E ' [BD] ' | c++filt | cut -f3- -d' ' | grep -v @ | grep -v : | sort | grep '[a-z]' | sort -u | grep -vE '(^_|typeinfo|vtable)'); do
REFERENCES=$(git grep -lE "([^a-zA-Z]|^)${SYMBOL}([^a-zA-Z]|\$)" -- "*.cpp" "*.h")
N_REFERENCES=$(wc -l <<< "${REFERENCES}")
if [[ ${N_REFERENCES} > 1 ]]; then
continue
fi
echo "Global symbol ${SYMBOL} is used in only one translation unit: ${REFERENCES}"
done
Global symbol g_chainstate is used in only one translation unit: src/validation.cpp
Global symbol g_ui_signals is used in only one translation unit: src/ui_interface.cpp
Global symbol instance_of_cmaincleanup is used in only one translation unit: src/validation.cpp
Global symbol instance_of_cnetcleanup is used in only one translation unit: src/net.cpp
Global symbol instance_of_cnetprocessingcleanup is used in only one translation unit: src/net_processing.cpp
Global symbol pindexBestForkBase is used in only one translation unit: src/validation.cpp
Global symbol pindexBestForkTip is used in only one translation unit: src/validation.cpp
$
```
After:
```
$ for SYMBOL in $(nm src/bitcoind | grep -E ' [BD] ' | c++filt | cut -f3- -d' ' | grep -v @ | grep -v : | sort | grep '[a-z]' | sort -u | grep -vE '(^_|typeinfo|vtable)'); do
REFERENCES=$(git grep -lE "([^a-zA-Z]|^)${SYMBOL}([^a-zA-Z]|\$)" -- "*.cpp" "*.h")
N_REFERENCES=$(wc -l <<< "${REFERENCES}")
if [[ ${N_REFERENCES} > 1 ]]; then
continue
fi
echo "Global symbol ${SYMBOL} is used in only one translation unit: ${REFERENCES}"
done
$
```
♻️ Think about future generations: save the global namespace from unnecessary pollution! ♻️
ACKs for commit 0959d3:
Empact:
ACK 0959d37e3e
MarcoFalke:
ACK 0959d37e3e
hebasto:
ACK 0959d37e3e
promag:
ACK 0959d37.
Tree-SHA512: 722f66bb50450f19b57e8a8fbe949f30cd651eb8564e5787cbb772a539bf3a288c048dc49e655fd73ece6a46f6dafade515ec4004729bf2b3ab83117b7c5d153
308b76732f Fix bug around transaction requests (Suhas Daftuar)
f635a3ba11 Expire old entries from the in-flight tx map (Suhas Daftuar)
e32e08407e Remove NOTFOUND transactions from in-flight data structures (Suhas Daftuar)
23163b7593 Add an explicit memory bound to m_tx_process_time (Suhas Daftuar)
218697b645 Improve NOTFOUND comment (Suhas Daftuar)
Pull request description:
#14897 introduced several bugs that could lead to a node no longer requesting transactions from one or more of its peers. Credit to ajtowns for originally reporting many of these bugs along with an originally proposed fix in #15776.
This PR does a few things:
- Fix a bug in NOTFOUND processing, where the in-flight map for a peer was keeping transactions it shouldn't
- Eliminate the possibility of a memory attack on the CNodeState `m_tx_process_time` data structure by explicitly bounding its size
- Remove entries from a peer's in-flight map after 10 minutes, so that we should always eventually resume transaction requests even if there are other bugs like the NOTFOUND one
- Fix a bug relating to the coordination of request times when multiple peers announce the same transaction
The expiry mechanism added here is something we'll likely want to remove in the future, but is belt-and-suspenders for now to try to ensure we don't have other bugs that could lead to transaction relay failing due to some unforeseen conditions.
ACKs for commit 308b76:
ajtowns:
utACK 308b76732f
morcos:
light ACK 308b767
laanwj:
Code review ACK 308b76732f
jonatack:
Light ACK 308b76732f.
jamesob:
ACK 308b76732f
MarcoFalke:
ACK 308b76732f (Tested two of the three bugs this pull fixes, see comment above)
jamesob:
Concept ACK 308b76732f
MarcoFalke:
ACK 308b76732f
Tree-SHA512: 8865dca5294447859d95655e8699085643db60c22f0719e76e961651a1398251bc932494b68932e33f68d4f6084579ab3bed7d0e7dd4ac6c362590eaf9414eda
67f4e9c522 Include core_io.h from core_read.cpp (practicalswift)
eca9767673 Make reasoning about dependencies easier by not including unused dependencies (practicalswift)
Pull request description:
Make reasoning about dependencies easier by not including unused dependencies.
Please note that the removed headers are _not_ "transitively included" by other still included headers. Thus the removals are real.
As an added bonus this change means less work for the preprocessor/compiler. At least 51 393 lines of code no longer needs to be processed:
```
$ git diff -u HEAD~1 | grep -E '^\-#include ' | cut -f2 -d"<" | cut -f1 -d">" | \
sed 's%^%src/%g' | xargs cat | wc -l
51393
```
Note that 51 393 is the lower bound: the real number is likely much higher when taking into account transitively included headers :-)
ACKs for commit 67f4e9:
Tree-SHA512: 0c8868aac59813f099ce53d5307eed7962dd6f2ff3546768ef9e5c4508b87f8210f1a22c7e826c3c06bebbf28bdbfcf1628ed354c2d0fdb9a31a42cefb8fdf13
403e677c9 refactoring: IsInitialBlockDownload -> CChainState (James O'Beirne)
3ccbc376d refactoring: FlushStateToDisk -> CChainState (James O'Beirne)
4d6688603 refactoring: introduce ChainstateActive() (James O'Beirne)
d7c97edee move-only: make the CChainState interface public (James O'Beirne)
Pull request description:
This is part of the [assumeutxo project](https://github.com/bitcoin/bitcoin/projects/11):
Parent PR: #15606
Issue: #15605
Specification: https://github.com/jamesob/assumeutxo-docs/tree/2019-04-proposal/proposal
---
This changeset starts moving functionality intimately related to CChainState into methods. Parameterizing these functions by a particular CChainState is necessary for the use of multiple chainstates simultaneously (e.g. for asynchronous background validation).
In this change, we
- make the CChainState interface public - since other units will start to invoke its methods directly,
- introduce `::ChainstateActive()`, the CChainState equivalent for `::ChainActive()`,
- and move `IsInitialBlockDownload()` and `FlushStateToDisk()` into methods on CChainState.
Independent of assumeutxo, these changes better encapsulate chainstate behavior and allow easier use from a testing context.
There are more methods that we'll move in the future, but they require other substantial changes (i.e. moving ownership of the `CCoinsView*` hierarchy into CChainState) so we'll save them for future PRs.
---
The first move-only commit is most easily reviewed with `git diff ... --color-moved=dimmed_zebra`.
ACKs for commit 403e67:
Empact:
utACK 403e677c9e no need to address my nits herein
Sjors:
utACK 403e677
ryanofsky:
utACK 403e677c9e. Only change since previous review is removing global state comment as suggested.
MarcoFalke:
utACK 403e677c9e, though the diff still seems a bit bloated with some unnecessary changes in the second commit.
promag:
utACK 403e677 and rebased with current [master](c7cfd20a7).
Tree-SHA512: 6fcf260bb2dc201361170c0b4547405366f5f331fcc3a2bac29b24442814b7b244ca1b58aac5af716885f9a130c343b544590dff780da0bf835c7c5b3ccb2257
This commit adds comments referencing multiple CVEs both in production and test code.
CVEs covered in this commit:
CVE-2010-5137
CVE-2010-5139
CVE-2010-5141
CVE-2012-1909
CVE-2012-2459
CVE-2012-3789
CVE-2018-17144
If a transaction is already in-flight when a peer announces a new tx to us, we
schedule a time in the future to reconsider whether to download. At that future
time, there was a bug that would prevent transactions from being rescheduled
for potential download again (ie if the transaction was still in-flight at the
time of reconsideration, such as from some other peer). Fix this.
If a peer hasn't responded to a getdata request, eventually time out the request
and remove it from the in-flight data structures. This is to prevent any bugs in
our handling of those in-flight data structures from filling up the in-flight
map and preventing us from requesting more transactions (such as the NOTFOUND
bug, fixed in a previous commit).
Co-authored-by: Anthony Towns <aj@erisian.com.au>
fa2b52af32 Disallow extended encoding for non-witness transactions (take 3) (MarcoFalke)
Pull request description:
(previous title "p2p: Disallow extended encoding for non-witness transactions (take 3)")
Remote peers can send us illegally encoded txs and thus have us write to stderr. Fix that by not writing to stderr.
This is a follow up to the previous (incomplete) attempts at this:
* Disallow extended encoding for non-witness transactions #14039
* Add test for superfluous witness record in deserialization #15893
ACKs for commit fa2b52:
laanwj:
utACK fa2b52af32
ryanofsky:
utACK fa2b52af32. Would change title to something like "Avoid logging transaction decode errors to stderr" instead of "Disallow extended encoding for non-witness transactions." The current title is confusing because this PR isn't really allowing or disallowing anything, just logging the condition differently. "Disallow" also seems to contradict the "Allow exceptions from..." comments in the actual code.
Tree-SHA512: c66990e69b432d00dc1c5510bf976a1188664d0890a32d1e5c6459094e7e27da82a5d227627afcbc203676f5540eec74b7d9b1d71d2c62d3b2069e1781824b4d
486c1eea86 refactoring: remove unused chainActive (James O'Beirne)
631940aab2 scripted-diff: replace chainActive -> ::ChainActive() (James O'Beirne)
a3a609079c refactoring: introduce unused ChainActive() (James O'Beirne)
1b6e6fcfd2 rename: CChainState.chainActive -> m_chain (James O'Beirne)
Pull request description:
This is part of the assumeutxo project:
Parent PR: #15606
Issue: #15605
Specification: https://github.com/jamesob/assumeutxo-docs/tree/2019-04-proposal/proposal
---
This change refactors the `chainActive` reference into a `::ChainActive()` call. It also distinguishes `CChainState`'s `CChain` data member as `m_chain` instead of the current `chainActive`, which makes it easily confused with the global data.
The active chain must be obtained via function because its reference will be swapped at some point during runtime after loading a UTXO snapshot.
This change, though lengthy, should be pretty easy to review since most of it is contained within a scripted-diff. Once merged, the parent PR should be easier to review.
ACKs for commit 486c1e:
Sjors:
utACK 486c1ee
promag:
utACK 486c1ee.
practicalswift:
utACK 486c1eea86
Tree-SHA512: 06ed8f9e77f2d25fc9bea0ba86436d80dbbce90a1e8be23e37ec4eeb26060483e60b4a5c4fba679cb1867f61e3921c24abeb9cabdfb4d0a9b1c4ddd77b17456a
Though at the moment ChainActive() simply references `g_chainstate.m_chain`,
doing this change now clears the way for multiple chainstate usage and allows
us to script the diff.
-BEGIN VERIFY SCRIPT-
git grep -l "chainActive" | grep -E '(h|cpp)$' | xargs sed -i '/chainActive =/b; /extern CChain& chainActive/b; s/\(::\)\{0,1\}chainActive/::ChainActive()/g'
-END VERIFY SCRIPT-
This is a first step towards cleaning up our DoS interface - make
validation return *why* something is invalid, and let net_processing
figure out what that implies in terms of banning/disconnection/etc.
Behavior change: peers will now be banned for providing blocks
with premature coinbase spends.
Co-authored-by: Anthony Towns <aj@erisian.com.au>
Suhas Daftuar <sdaftuar@gmail.com>
Isolate the decision of whether to ban a peer to one place in the
code, rather than having it sprinkled throughout net_processing.
Co-authored-by: Anthony Towns <aj@erisian.com.au>
Suhas Daftuar <sdaftuar@gmail.com>
John Newbery <john@johnnewbery.com>
This prevents a bug where the in-flight queue for our peers will not be
drained, resulting in not downloading any new transactions from our peers.
Thanks to ajtowns for reporting this bug.
