This commit extends our inbound eviction protection to CJDNS peers to
favorise the diversity of peer connections, as peers connected
through the CJDNS network are otherwise disadvantaged by our eviction
criteria for their higher latency (higher min ping times) relative
to IPv4 and IPv6 peers.
The `networks` array is order-dependent in the case of a tie in
candidate counts between networks; earlier array members receive
priority in the case of a tie.
Therefore, we place CJDNS candidates before I2P, localhost, and onion
ones in terms of opportunity to recover unused remaining protected
slots from the previous iteration, estimating that most nodes allowing
several inbound privacy networks will have more onion, localhost or
I2P peers than CJDNS ones, as CJDNS support is only being added in the
upcoming v23.0 release.
dec787d8ac refactor: replace RecursiveMutex `m_addr_local_mutex` with Mutex (w0xlt)
93609c1dfa p2p: add assertions and negative TS annotations for m_addr_local_mutex (w0xlt)
c4a31ca267 scripted-diff: rename cs_addrLocal -> m_addr_local_mutex (w0xlt)
Pull request description:
This PR is related to #19303 and gets rid of the `RecursiveMutex cs_addrLocal`.
ACKs for top commit:
hebasto:
ACK dec787d8ac, I have reviewed the code and it looks OK, I agree it can be merged.
shaavan:
reACK dec787d8ac
Tree-SHA512: b7a043bfd4e2ccbe313bff21ad815169db6ad215ca96daf358ce960c496a548b4a9e90be9e4357430ca59652b96df87c097450118996c6d4703cbaabde2072d0
224d87855e net, refactor: Drop tautological local variables (Hennadii Stepanov)
3073a9917b scripted-diff: Rename CNetMessage::m_command with CNetMessage::m_type (Hennadii Stepanov)
Pull request description:
https://github.com/bitcoin/bitcoin/pull/18533#issue-594592488:
> a message is not a command, but simply a message of some type
Continuation of bitcoin/bitcoin#18533 and bitcoin/bitcoin#18937.
ACKs for top commit:
theStack:
Concept and code-review ACK 224d87855e
shaavan:
Code Review ACK 224d87855e
w0xlt:
crACK 224d878
Tree-SHA512: 898cafb44708dae1413fcc1533d809d75878891354f1b5edaaec1287f4921c31adc9330f4d42d82544a39689886bc17fee71ea587f9199fd5cc849d376f82176
9b8dcb25b5 [net processing] Rename PoissonNextSendInbound to NextInvToInbounds (John Newbery)
ea99f5d01e [net processing] Move PoissonNextSendInbound to PeerManager (John Newbery)
bb060746df scripted-diff: replace PoissonNextSend with GetExponentialRand (John Newbery)
03cfa1b603 [refactor] Use uint64_t and std namespace in PoissonNextSend (John Newbery)
9e64d69bf7 [move] Move PoissonNextSend to src/random and update comment (John Newbery)
Pull request description:
`PoissonNextSend` and `PoissonNextSendInbound` are used in the p2p code to obfuscate various regularly occurring processes, in order to make it harder for others to get timing-based information deterministically.
The naming of these functions has been confusing to several people (including myself, see also #23347) because the resulting random timestamps don't follow a Poisson distribution but an exponential distribution (related to events in a Poisson process, hence the name). This PR
- moves `PoissonNextSend()` out of `net` to `random` and renames it to `GetExponentialRand()`
- moves `PoissonNextSendInbound()` out of `CConnman` to `PeerManager` and renames it to `NextInvToInbounds()`
- adds documentation for these functions
This is work by jnewbery - due to him being less active currently, I opened the PR and will address feedback.
ACKs for top commit:
jnewbery:
ACK 9b8dcb25b5
hebasto:
ACK 9b8dcb25b5, I have reviewed the code and it looks OK, I agree it can be merged.
theStack:
ACK 9b8dcb25b5📊
Tree-SHA512: 85c366c994e7147f9981fe863fb9838502643fa61ffd32d55a43feef96a38b79a5daa2c4d38ce01074897cc95fa40c76779816edad53f5265b81b05c3a1f4f50
-BEGIN VERIFY SCRIPT-
s() { sed -i 's/cs_mapLocalHost/g_maplocalhost_mutex/g' $1; }
s src/net.cpp
s src/net.h
s src/rpc/net.cpp
s src/test/net_tests.cpp
-END VERIFY SCRIPT-
-BEGIN VERIFY SCRIPT-
sed -i 's/std::string m_command;/std::string m_type;/g' ./src/net.h
sed -i 's/* command and size./* type and size./g' ./src/net.h
sed -i 's/msg.m_command/msg.m_type/g' ./src/net.cpp ./src/net_processing.cpp ./src/test/fuzz/p2p_transport_serialization.cpp
-END VERIFY SCRIPT-
This distribution is used for more than just the next inv send, so make
the name more generic.
Also rename to "exponential" to avoid the confusion that this is a
poisson distribution.
-BEGIN VERIFY SCRIPT-
ren() { sed -i "s/\<$1\>/$2/g" $(git grep -l "$1" ./src) ; }
ren PoissonNextSend GetExponentialRand
ren "a poisson timer" "an exponential timer"
-END VERIFY SCRIPT-
6bf6e9fd9d net: change CreateNodeFromAcceptedSocket() to take Sock (Vasil Dimov)
9e3cbfca7c net: use Sock in CConnman::ListenSocket (Vasil Dimov)
f8bd13f85a net: add new method Sock::Accept() that wraps accept() (Vasil Dimov)
Pull request description:
_This is a piece of https://github.com/bitcoin/bitcoin/pull/21878, chopped off to ease review._
Introduce an `accept(2)` wrapper `Sock::Accept()` and extend the usage of `Sock` in `CConnman::ListenSocket` and `CreateNodeFromAcceptedSocket()`.
ACKs for top commit:
laanwj:
Code review ACK 6bf6e9fd9d
jamesob:
ACK 6bf6e9fd9d ([`jamesob/ackr/21879.2.vasild.wrap_accept_and_extend_u`](https://github.com/jamesob/bitcoin/tree/ackr/21879.2.vasild.wrap_accept_and_extend_u))
jonatack:
ACK 6bf6e9fd9d per `git range-diff ea989de 976f6e8 6bf6e9f` -- only change since my last review was `s/listen_socket.socket/listen_socket.sock->Get()/` in `src/net.cpp: CConnman::SocketHandlerListening()` -- re-read the code changes, rebase/debug build/ran units following my previous full review (https://github.com/bitcoin/bitcoin/pull/21879#pullrequestreview-761251278)
w0xlt:
tACK 6bf6e9f
Tree-SHA512: dc6d1acc4f255f1f7e8cf6dd74e97975cf3d5959e9fc2e689f74812ac3526d5ee8b6a32eca605925d10a4f7b6ff1ce5e900344311e587d19786b48c54d021b64
fad943821e scripted-diff: Rename touched member variables (MarcoFalke)
fa663a4c0d Use mockable time for peer connection time (MarcoFalke)
fad7ead146 refactor: Use type-safe std::chrono in net (MarcoFalke)
Pull request description:
Benefits:
* Type-safe
* Mockable
* Allows to revert a temporary test workaround
ACKs for top commit:
naumenkogs:
ACK fad943821e
shaavan:
ACK fad943821e
Tree-SHA512: af9bdfc695ab727b100c6810a7289d29b02b0ea9fa4fee9cc1f3eeefb52c8c465ea2734bae0c1c63b3b0d6264ba2c493268bc970ef6916570eb166de77829d82
eaf6be0114 [net processing] Do not request transaction relay from feeler connections (John Newbery)
0220b834b1 [test] Add testing for outbound feeler connections (John Newbery)
Pull request description:
Feelers are short-lived connections used to test the viability of peers. The bitcoind node will periodically open feeler connections to addresses in its addrman, wait for a `version` message from the peer, and then close the connection.
Currently, we set `fRelay` to `1` in the `version` message for feeler connections, indicating that we want the peer to relay transactions to us. However, we close the connection immediately on receipt of the `version` message, and so never process any incoming transaction announcements. This PR changes that behaviour to instead set `fRelay` to `0` indicating that we do not wish to receive transaction announcements from the peer.
This PR also extends the `addconnection` RPC to allow creating outbound feeler connections from the node to the test framework, and a test to verify that the node sets `fRelay` to `0` in the `version` message to feeler connections.
ACKs for top commit:
naumenkogs:
ACK eaf6be0114
MarcoFalke:
review ACK eaf6be0114🏃
Tree-SHA512: 1c56837dbd0a396fe404a5e39f7459864d15f666664d6b35ad109628b13158e077e417e586bf48946a23bd5cbe63716cb4bf22cdf8781b74dfce6047b87b465a
fadc0c80ae p2p: Make timeout mockable and type safe, speed up test (MarcoFalke)
fa6d5a238d scripted-diff: Rename m_last_send and m_last_recv (MarcoFalke)
Pull request description:
Use type-safe time for better code readability/maintainability and mockable time for better testability. This speeds up the p2p_timeout test.
This is also a bugfix for intermittent test issues like: https://cirrus-ci.com/task/4769904156999680?command=ci#L2836Fixes#20654
ACKs for top commit:
laanwj:
Code review ACK fadc0c80ae
naumenkogs:
ACK fadc0c80ae
Tree-SHA512: 28c6544c97f188c8a0fbc80411c74ab74ffd055885322c325aa3d1c404b29c3fd70a737e86083eecae58ef394db1cb56bc122d06cff63742aa89a8e868730c64
11daf6ceb1 More Span simplifications (Pieter Wuille)
568dd2f839 Replace MakeSpan helper with Span deduction guide (Pieter Wuille)
Pull request description:
C++17 supports [user-defined deduction guides](https://en.cppreference.com/w/cpp/language/class_template_argument_deduction), allowing class constructors to be invoked without specifying class template arguments. Instead, the code can contain rules to infer the template arguments from the constructor argument types.
This alleviates the need for the `MakeSpan` helper. Convert the existing MakeSpan rules into deduction rules for `Span` itself, and replace all invocations of `MakeSpan` with just `Span` ones.
ACKs for top commit:
MarcoFalke:
re-ACK 11daf6ceb1 Only change is removing a hunk in the tests 🌕
Tree-SHA512: 10f3e82e4338f39d9b7b407cd11aac7ebe1e9191b58e3d7f4e5e338a4636c0e126b4a1d912127c7446f57ba356c8d6544482e47f97901efea6a54fffbfd7895f
fa551b3bdd Remove GetAdjustedTime from init.cpp (MarcoFalke)
fa815f8473 Replace addrman.h include with forward decl in net.h (MarcoFalke)
Pull request description:
It seems confusing to call `GetAdjustedTime` there, because no offset could have been retrieved from the network at this point. Even if connman was started, `timedata` needs at least 5 peer connections to calculate an offset.
Fix the confusion by replacing `GetAdjustedTime` with `GetTime`, which does not change behavior.
Also:
* Replace magic number with `MAX_FUTURE_BLOCK_TIME` to clarify the context
* Add test, which passes both on current master and this pull request
* An unrelated refactoring commit, happy to drop
ACKs for top commit:
dongcarl:
Code Review ACK fa551b3bdd, noticed the exact same thing here: e073634c37
mzumsande:
Code Review ACK fa551b3bdd
jnewbery:
Code review ACK fa551b3bdd
shaavan:
ACK fa551b3bdd
theStack:
Code-review ACK fa551b3bdd
Tree-SHA512: 15807a0e943e3e8d8c5250c8f6d7b56afb26002b1e290bf93636a2c747f27e78f01f1de04ce1a83d6339e27284c69c43e077a8467545c4078746f4c1ecb1164d
Change `CConnman::CreateNodeFromAcceptedSocket()` to take a `Sock`
argument instead of `SOCKET`.
This makes the method mockable and also a little bit shorter as some
`CloseSocket()` calls are removed (the socket will be closed
automatically by the `Sock` destructor on early return).
Change `CConnman::ListenSocket` to use a pointer to `Sock` instead of a
bare `SOCKET` and use `Sock::Accept()` instead of bare `accept()`. This
will help mocking / testing / fuzzing more code.
The RecursiveMutex cs_totalBytesRecv is only used at two places: in
CConnman::RecordBytesRecv() to increment the nTotalBytesRecv member, and in
CConnman::GetTotalBytesRecv() to read it. For this simple use-case, we can
make the member std::atomic instead to achieve the same result.
f52b6b2d9f net: split CConnman::SocketHandler() (Vasil Dimov)
c7eb19ec83 style: remove unnecessary braces (Vasil Dimov)
664ac22c53 net: keep reference to each node during socket wait (Vasil Dimov)
75e8bf55f5 net: dedup and RAII-fy the creation of a copy of CConnman::vNodes (Vasil Dimov)
Pull request description:
_This is a piece of https://github.com/bitcoin/bitcoin/pull/21878, chopped off to ease review._
The following pattern was duplicated in CConnman:
```cpp
lock
create a copy of vNodes, add a reference to each one
unlock
... use the copy ...
lock
release each node from the copy
unlock
```
Put that code in a RAII helper that reduces it to:
```cpp
create snapshot "snap"
... use the copy ...
// release happens when "snap" goes out of scope
ACKs for top commit:
jonatack:
ACK f52b6b2d9f changes since last review are reordered commits, removing an unneeded local variable, and code formatting and documentation improvements
LarryRuane:
code review ACK f52b6b2d9f
promag:
Code review ACK f52b6b2d9f, only format changes and comment tweaks since last review.
Tree-SHA512: 5ead7b4c641ebe5b215e7baeb7bc0cdab2a588b2871d9a343a1d518535c55c0353d4e46de663f41513cdcc79262938ccea3232f6d5166570fc2230286c985f68
`CConnman::SocketHandler()` does 3 things:
1. Check sockets for readiness
2. Process ready listening sockets
3. Process ready connected sockets
Split the processing (2. and 3.) into separate methods to make the code
easier to grasp.
Also, move the processing of listening sockets after the processing of
connected sockets to make it obvious that there is no dependency and
also explicitly release the snapshot before dealing with listening
sockets - it is only necessary for the connected sockets part.
They were needed to define the scope of `LOCK(cs_vNodes)` which was
removed in the previous commit. Re-indent in a separate commit to ease
review (use `--ignore-space-change`).
Create the snapshot of `CConnman::vNodes` to operate on earlier in
`CConnman::SocketHandler()`, before calling `CConnman::SocketEvents()`
and pass the `vNodes` copy from the snapshot to `SocketEvents()`.
This will keep the refcount of each node incremented during
`SocketEvents()` so that the `CNode` object is not destroyed before
`SocketEvents()` has finished.
Currently in `SocketEvents()` we only remember file descriptor numbers
(when not holding `CConnman::cs_vNodes`) which is safe, but we will
change this to remember pointers to `CNode::m_sock`.
The following pattern was duplicated in CConnman:
```cpp
lock
create a copy of vNodes, add a reference to each one
unlock
... use the copy ...
lock
release each node from the copy
unlock
```
Put that code in a RAII helper that reduces it to:
```cpp
create snapshot "snap"
... use the copy ...
// release happens when "snap" goes out of scope
```
In some cases addresses come from an external source as a string or as a
`struct sockaddr_in6`, without a tag to tell whether it is a private
IPv6 or a CJDNS address. In those cases interpret the address as a CJDNS
address instead of an IPv6 address if `-cjdnsreachable` is set and the
seemingly-IPv6-address belongs to `fc00::/8`. Those external sources are:
* `-externalip=`
* `-bind=`
* UPnP
* `getifaddrs(3)` (called through `-discover`)
* `addnode`
* `connect`
* incoming connections (returned by `accept(2)`)
f3e451bebf [net] Replace GetID() with id in TransportDeserializer constructor (Troy Giorshev)
8c96008ab1 [net] Don't return an optional from TransportDeserializer::GetMessage() (Troy Giorshev)
Pull request description:
Also, access mapRecvBytesPerMsgCmd with `at()` not `find()`. This
throws an error if COMMAND_OTHER doesn't exist, which should never
happen. `find()` instead just accessed the last element, which could make
debugging more difficult.
Resolves review comments from PR19107:
- https://github.com/bitcoin/bitcoin/pull/19107#discussion_r478718436
- https://github.com/bitcoin/bitcoin/pull/19107#discussion_r478714497
ACKs for top commit:
theStack:
Code-review ACK f3e451bebf
ryanofsky:
Code review ACK f3e451bebf. Changes since last review in https://github.com/bitcoin/bitcoin/pull/20364#pullrequestreview-534369904 were simplifying by dropping the third commit, rebasing, and cleaning up some style & comments in the first commit.
Tree-SHA512: 37de4b25646116e45eba50206e82ed215b0d9942d4847a172c104da4ed76ea4cee29a6fb119f3c34106a9b384263c576cb8671d452965a468f358d4a3fa3c003
021f86953e [style] Run changed files through clang formatter. (Amiti Uttarwar)
375750387e scripted-diff: Rename CAddrInfo to AddrInfo (Amiti Uttarwar)
dd8f7f2500 scripted-diff: Rename CAddrMan to AddrMan (Amiti Uttarwar)
3c263d3f63 [includes] Fix up included files (Amiti Uttarwar)
29727c2aa1 [doc] Update comments (Amiti Uttarwar)
14f9e000d0 [refactor] Update GetAddr_() function signature (Amiti Uttarwar)
40acd6fc9a [move-only] Move constants to test-only header (Amiti Uttarwar)
7cf41bbb38 [addrman] Change CAddrInfo access (Amiti Uttarwar)
e3f1ea659c [move-only] Move CAddrInfo to test-only header file (Amiti Uttarwar)
7cba9d5618 [net, addrman] Remove external dependencies on CAddrInfo objects (Amiti Uttarwar)
8af5b54f97 [addrman] Introduce CAddrMan::Impl to encapsulate addrman implementation. (Amiti Uttarwar)
f2e5f38f09 [move-only] Match ordering of CAddrMan declarations and definitions (Amiti Uttarwar)
5faa7dd6d8 [move-only] Move CAddrMan function definitions to cpp (Amiti Uttarwar)
Pull request description:
Introduce the pimpl pattern for AddrMan to separate the implementation details from the externally used object representation. This reduces compile-time dependencies and conceptually clarifies AddrMan's interface from the implementation specifics.
Since the unit & fuzz tests currently rely on accessing AddrMan internals, this PR introduces addrman_impl.h, which is exclusively imported by addrman.cpp and test files.
ACKs for top commit:
jnewbery:
ACK 021f86953e
GeneFerneau:
utACK [021f869](021f86953e)
mzumsande:
ACK 021f86953e
rajarshimaitra:
Concept + Code Review ACK 021f86953e
theuni:
ACK 021f86953e
Tree-SHA512: aa70cb77927a35c85230163c0cf6d3872382d79048b0fb79341493caa46f8e91498cb787d8b06aba4da17b2f921f2230e73f3d66385519794fff86a831b3a71d
4747da3a5b Add syscall sandboxing (seccomp-bpf) (practicalswift)
Pull request description:
Add experimental syscall sandboxing using seccomp-bpf (Linux secure computing mode).
Enable filtering of system calls using seccomp-bpf: allow only explicitly allowlisted (expected) syscalls to be called.
The syscall sandboxing implemented in this PR is an experimental feature currently available only under Linux x86-64.
To enable the experimental syscall sandbox the `-sandbox=<mode>` option must be passed to `bitcoind`:
```
-sandbox=<mode>
Use the experimental syscall sandbox in the specified mode
(-sandbox=log-and-abort or -sandbox=abort). Allow only expected
syscalls to be used by bitcoind. Note that this is an
experimental new feature that may cause bitcoind to exit or crash
unexpectedly: use with caution. In the "log-and-abort" mode the
invocation of an unexpected syscall results in a debug handler
being invoked which will log the incident and terminate the
program (without executing the unexpected syscall). In the
"abort" mode the invocation of an unexpected syscall results in
the entire process being killed immediately by the kernel without
executing the unexpected syscall.
```
The allowed syscalls are defined on a per thread basis.
I've used this feature since summer 2020 and I find it to be a helpful testing/debugging addition which makes it much easier to reason about the actual capabilities required of each type of thread in Bitcoin Core.
---
Quick start guide:
```
$ ./configure
$ src/bitcoind -regtest -debug=util -sandbox=log-and-abort
…
2021-06-09T12:34:56Z Experimental syscall sandbox enabled (-sandbox=log-and-abort): bitcoind will terminate if an unexpected (not allowlisted) syscall is invoked.
…
2021-06-09T12:34:56Z Syscall filter installed for thread "addcon"
2021-06-09T12:34:56Z Syscall filter installed for thread "dnsseed"
2021-06-09T12:34:56Z Syscall filter installed for thread "net"
2021-06-09T12:34:56Z Syscall filter installed for thread "msghand"
2021-06-09T12:34:56Z Syscall filter installed for thread "opencon"
2021-06-09T12:34:56Z Syscall filter installed for thread "init"
…
# A simulated execve call to show the sandbox in action:
2021-06-09T12:34:56Z ERROR: The syscall "execve" (syscall number 59) is not allowed by the syscall sandbox in thread "msghand". Please report.
…
Aborted (core dumped)
$
```
---
[About seccomp and seccomp-bpf](https://en.wikipedia.org/wiki/Seccomp):
> In computer security, seccomp (short for secure computing mode) is a facility in the Linux kernel. seccomp allows a process to make a one-way transition into a "secure" state where it cannot make any system calls except exit(), sigreturn(), and read() and write() to already-open file descriptors. Should it attempt any other system calls, the kernel will terminate the process with SIGKILL or SIGSYS. In this sense, it does not virtualize the system's resources but isolates the process from them entirely.
>
> […]
>
> seccomp-bpf is an extension to seccomp that allows filtering of system calls using a configurable policy implemented using Berkeley Packet Filter rules. It is used by OpenSSH and vsftpd as well as the Google Chrome/Chromium web browsers on Chrome OS and Linux. (In this regard seccomp-bpf achieves similar functionality, but with more flexibility and higher performance, to the older systrace—which seems to be no longer supported for Linux.)
ACKs for top commit:
laanwj:
Code review and lightly tested ACK 4747da3a5b
Tree-SHA512: e1c28e323eb4409a46157b7cc0fc29a057ba58d1ee2de268962e2ade28ebd4421b5c2536c64a3af6e9bd3f54016600fec88d016adb49864b63edea51ad838e17
CAddrInfo objects are an implementation detail of how AddrMan manages and adds
metadata to different records. Encapsulate this logic by updating Select &
SelectTriedCollision to return the additional info that the callers need.
330d3aa1a2 refactor: net: avoid duplicate map lookups to `mapLocalHost` (Sebastian Falbesoner)
Pull request description:
This simple refactoring PR aims to avoid duplicate lookups to `mapLocalHost`: instead of calling `count()` (to first find out whether a key is in the map) and then `operator[]` (to get the value to the passed key, or default-construct one if not found), use either
* `find()` and dereference the returned iterator (for simple lookups), see https://www.cplusplus.com/reference/map/map/find/
* `emplace()` and use the returned <iterator, inserted> pair (for lookups where a new element should be inserted if the key isn't found), see https://www.cplusplus.com/reference/map/map/emplace/
ACKs for top commit:
naumenkogs:
ACK 330d3aa1a2
jonatack:
Code review ACK 330d3aa1a2 plus rebase to master + debug build
Tree-SHA512: d13da6a927ff561eee8ac6b093bf3586dfe31d6c94173a5a6d8f3698e0ee224fb394d3635155d5141c165da59d2c2c37260122eb4f2e8bcda3e8a29b901d213e
