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
853c4edb70 [net] Remove asmap argument from CNode::CopyStats() (John Newbery)
9fd5618610 [asmap] Make DecodeAsmap() a utility function (John Newbery)
bfdf4ef334 [asmap] Remove SanityCheckASMap() from netaddress (John Newbery)
07a9eccb60 [net] Remove CConnman::Options.m_asmap (John Newbery)
Pull request description:
These small cleanups to the asmap code are the first 4 commits from #22910. They're minor improvements that are independently useful whether or not 22910 is merged.
ACKs for top commit:
naumenkogs:
ACK 853c4edb70
theStack:
Concept and code-review ACK 853c4edb70🗺️
fanquake:
ACK 853c4edb70
Tree-SHA512: 64783743182592ac165df6ff8d18870b63861e9204ed722c207fca6938687aac43232a5ac4d8228cf8b92130ab0349de1b410a2467bb5a9d60dd9a7221b3b85b
The class only stores the file path, reading it from a global. Globals
are confusing and make testing harder.
The method reading from a stream does not even use any class members, so
putting it in a class is also confusing.
724c497562 [fuzz] Add ConsumeAsmap() function (John Newbery)
5840476714 [addrman] Make m_asmap private (John Newbery)
f9002cb5db [net] Rename the copyStats arg from m_asmap to asmap (John Newbery)
f572f2b204 [addrman] Set m_asmap in CAddrMan initializer list (John Newbery)
593247872d [net] Remove CConnMan::SetAsmap() (John Newbery)
50fd77045e [init] Read/decode asmap before constructing addrman (John Newbery)
Pull request description:
Commit 181a1207 introduced an initialization order bug: CAddrMan's m_asmap must be set before deserializing peers.dat.
The first commit restores the correct initialization order. The remaining commits make `CAddrMan::m_asmap` usage safer:
- don't reach into `CAddrMan`'s internal data from `CConnMan`
- set `m_asmap` in the initializer list and make it const
- make `m_asmap` private, and access it (as a reference to const) from a getter.
This ensures that peers.dat deserialization must happen after setting m_asmap, since m_asmap is set during CAddrMan construction.
ACKs for top commit:
mzumsande:
Tested ACK 724c497562
amitiuttarwar:
code review but utACK 724c497562
naumenkogs:
utACK 724c497562
vasild:
ACK 724c497562
MarcoFalke:
review ACK 724c497562👫
Tree-SHA512: 684a4cf9e3d4496c9997fb2bc4ec874809987055c157ec3fad1d2143b8223df52b5a0af787d028930b27388c8efeba0aeb2446cb35c337a5552ae76112ade726
Improve readability of code, simplify future scripted diff cleanup PRs, and be
more consistent with naming for GetBoolArg.
This will also be useful for replacing runtime settings type checking
with compile time checking.
-BEGIN VERIFY SCRIPT-
git grep -l GetArg | xargs sed -i 's/GetArg(\([^)]*\( [0-9]\+\|-1\|port\|BaseParams().RPCPort()\|Params().GetDefaultPort()\|_TIMEOUT\|Height\|_WORKQUEUE\|_THREADS\|_CONNECTIONS\|LIMIT\|SigOp\|Bytes\|_VERSION\|_AGE\|_CHECKS\|Checks() ? 1 : 0\|_BANTIME\|Cache\|BLOCKS\|LEVEL\|Weight\|Version\|BUFFER\|TARGET\|WEIGHT\|TXN\|TRANSACTIONS\|ADJUSTMENT\|i64\|Size\|nDefault\|_EXPIRY\|HEIGHT\|SIZE\|SNDHWM\|_TIME_MS\)\))/GetIntArg(\1)/g'
-END VERIFY SCRIPT-
Co-authored-by: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>
The m_ prefix indicates that a variable is a data member. Using it as
a parameter name is misleading.
Also update the name of the function from copyStats to CopyStats to
comply with our style guide.
This logic is a no-op since it was introduced in commit
f9f5cfc506.
m_addr_name is never initialized to the empty string, because
ToStringIPPort never returns an empty string.
5730a43703 test: Add functional test for AddrFetch connections (Martin Zumsande)
c34ad3309f net, rpc: Enable AddrFetch connections for functional testing (Martin Zumsande)
533500d907 p2p: Add timeout for AddrFetch peers (Martin Zumsande)
b6c5d1e450 p2p: AddrFetch - don't disconnect on self-announcements (Martin Zumsande)
Pull request description:
AddrFetch connections (old name: oneshots) are intended to be short-lived connections on which we ask a peer for addresses via `getaddr` and disconnect after receiving them.
This is done by disconnecting after receiving the first `addr`. However, it is no longer working as intended, because nowadays, the first `addr` a typical bitcoin core node sends is its self-announcement.
So we'll disconnect before the peer gets a chance to answer our `getaddr`.
I checked that this affects both `-seednode` peers specified manually, and DNS seeds when AddrFetch is used as a fallback if DNS doesn't work for us.
The current behavior of getting peers via AddrFetch when starting with an empty addrman would be to connect to the peer, receive its self-announcement and add it to addrman, disconnect, reconnect to the same peer again as a full outbound (no other addresses in addrman) and then receive more `addr`. This is silly and not in line with AddrFetch peer being intended to be short-lived peers.
Fix this by only disconnecting after receiving an `addr` message of size > 1.
[Edit] As per review discussion, this PR now also adds a timeout after which we disconnect if we haven't received any suitable `addr`, and a functional test.
ACKs for top commit:
amitiuttarwar:
reACK 5730a43703
naumenkogs:
ACK 5730a43703
jnewbery:
ACK 5730a43703
Tree-SHA512: 8a81234f37e827705138eb254223f7f3b3bf44a06cb02126fc7990b0d231b9bd8f07d38d185cc30d55bf35548a6fdc286b69602498d875b937e7c58332158bf9
b1d905c225 p2p: earlier continuation when no remaining eviction candidates (Vasil Dimov)
c9e8d8f9b1 p2p: process more candidates per protection iteration (Jon Atack)
02e411ec45 p2p: iterate eviction protection only on networks having candidates (Jon Atack)
5adb064574 bench: add peer eviction protection benchmarks (Jon Atack)
566357f8f7 refactor: move GetRandomNodeEvictionCandidates() to test utilities (Jon Atack)
Pull request description:
This follow-up to #21261 improves `ProtectEvictionCandidatesByRatio()` for better performance.
Benchmarks are added; the performance improvement is between 2x and 5x for the benchmarked cases (CPU 2.50GHz, Turbo off, performance mode, Debian Clang 11 non-debug build).
```
$ ./src/bench/bench_bitcoin -filter="EvictionProtection*.*"
```
The refactored code is well-covered by existing unit tests and also a fuzzer.
- `$ ./src/test/test_bitcoin -t net_peer_eviction_tests`
- `$ FUZZ=node_eviction ./src/test/fuzz/fuzz ../qa-assets/fuzz_seed_corpus/node_eviction`
ACKs for top commit:
klementtan:
Tested and code review ACK b1d905c2.
vasild:
ACK b1d905c225
jarolrod:
ACK b1d905c225
Tree-SHA512: a3a6607b9ea2fec138da9780c03f63e177b6712091c5a3ddc3804b896a7585216446310280791f5e20cc023d02d2f03a4139237e12b5c1d7f2a1fa1011610e96
4101ec9d2e doc: mention that we enforce port=0 in I2P (Vasil Dimov)
e0a2b390c1 addrman: reset I2P ports to 0 when loading from disk (Vasil Dimov)
41cda9d075 test: ensure I2P ports are handled as expected (Vasil Dimov)
4f432bd738 net: do not connect to I2P hosts on port!=0 (Vasil Dimov)
1f096f091e net: distinguish default port per network (Vasil Dimov)
aeac3bce3e net: change I2P seeds' ports to 0 (Vasil Dimov)
38f900290c net: change assumed I2P port to 0 (Vasil Dimov)
Pull request description:
_This is an alternative to https://github.com/bitcoin/bitcoin/pull/21514, inspired by https://github.com/bitcoin/bitcoin/pull/21514#issuecomment-815049933. They are mutually exclusive. Just one of them should be merged._
Change assumed ports for I2P to 0 (instead of the default 8333) as this is closer to what actually happens underneath with SAM 3.1 (https://github.com/bitcoin/bitcoin/pull/21514#issuecomment-812632520, https://github.com/bitcoin/bitcoin/pull/21514#issuecomment-816564719).
Don't connect to I2P peers with advertised port != 0 (we don't specify a port to our SAM 3.1 proxy and it always connects to port = 0).
Note, this change:
* Keeps I2P addresses with port != 0 in addrman and relays them to others via P2P gossip. There may be non-bitcoin-core-22.0 peers using SAM 3.2 and for them such addresses may be useful.
* Silently refuses to connect to I2P hosts with port != 0. This is ok for automatically chosen peers from addrman. Not so ok for peers provided via `-addnode` or `-connect` - a user who specifies `foo.b32.i2p:1234` (non zero port) may wonder why "nothing is happening".
Fixes#21389
ACKs for top commit:
laanwj:
Code review ACK 4101ec9d2e
jonatack:
re-ACK 4101ec9d2e per `git range-diff efff9c3 0b0ee03 4101ec9`, built with DDEBUG_ADDRMAN, did fairly extensive testing on mainnet both with and without a peers.dat / -dnsseeds=0 to test boostrapping.
Tree-SHA512: 0e3c019e1dc05e54f559275859d3450e0c735596d179e30b66811aad9d5b5fabe3dcc44571e8f7b99f9fe16453eee393d6e153454dd873b9ff14907d4e6354fe
2feec3ce31 net: don't bind on 0.0.0.0 if binds are restricted to Tor (Vasil Dimov)
Pull request description:
The semantic of `-bind` is to restrict the binding only to some address.
If not specified, then the user does not care and we bind to `0.0.0.0`.
If specified then we should honor the restriction and bind only to the
specified address.
Before this change, if no `-bind` is given then we would bind to
`0.0.0.0:8333` and to `127.0.0.1:8334` (incoming Tor) which is ok -
the user does not care to restrict the binding.
However, if only `-bind=addr:port=onion` is given (without ordinary
`-bind=`) then we would bind to `addr:port` _and_ to `0.0.0.0:8333` in
addition.
Change the above to not do the additional bind: if only
`-bind=addr:port=onion` is given (without ordinary `-bind=`) then bind
to `addr:port` (only) and consider incoming connections to that as Tor
and do not advertise it. I.e. a Tor-only node.
ACKs for top commit:
laanwj:
Code review ACK 2feec3ce31
jonatack:
utACK 2feec3ce31 per `git diff a004833 2feec3c`
hebasto:
ACK 2feec3ce31, tested on Linux Mint 20.1 (x86_64):
Tree-SHA512: a04483af601706da928958b92dc560f9cfcc78ab0bb9d74414636eed1c6f29ed538ce1fb5a17d41ed82c9c9a45ca94899d0966e7ef93da809c9bcdcdb1d1f040
in ProtectEvictionCandidatesByRatio().
With this change, `if (n.count == 0) continue;` will be true
if a network had candidates protected in the first iterations
and has no candidates remaining to be protected in later iterations.
Co-authored-by: Jon Atack <jon@atack.com>
for the usual case when some of the protected networks
don't have eviction candidates, to reduce the number
of iterations in ProtectEvictionCandidatesByRatio().
Picks up an idea in ef411cd2 that I had dropped.
in ProtectEvictionCandidatesByRatio().
Thank you to Vasil Dimov, whose suggestions during a post-merge
discussion about PR 21261 reminded me that I had done this in
earlier versions of the PR, e.g. commits like ef411cd2.
Co-authored-by: Vasil Dimov <vd@FreeBSD.org>
The semantic of `-bind` is to restrict the binding only to some address.
If not specified, then the user does not care and we bind to `0.0.0.0`.
If specified then we should honor the restriction and bind only to the
specified address.
Before this change, if no `-bind` is given then we would bind to
`0.0.0.0:8333` and to `127.0.0.1:8334` (incoming Tor) which is ok -
the user does not care to restrict the binding.
However, if only `-bind=addr:port=onion` is given (without ordinary
`-bind=`) then we would bind to `addr:port` _and_ to `0.0.0.0:8333` in
addition.
Change the above to not do the additional bind: if only
`-bind=addr:port=onion` is given (without ordinary `-bind=`) then bind
to `addr:port` (only) and consider incoming connections to that as Tor
and do not advertise it. I.e. a Tor-only node.
79c02c88b3 Randomize message processing peer order (Pieter Wuille)
Pull request description:
Right now, the message handling loop iterates the list of nodes always in the same order: the order they were connected in (see the `vNodes` vector). For some parts of the net processing logic, this order matters. Transaction requests are assigned explicitly to peers since #19988, but many other parts of processing work on a "first-served-by-loop-first" basis, such as block downloading. If peers can predict this ordering, it may be exploited to cause delays.
As there isn't anything particularly optimal about the current ordering, just make it unpredictable by randomizing.
Reported by Crypt-iQ.
ACKs for top commit:
jnewbery:
ACK 79c02c88b3
Crypt-iQ:
ACK 79c02c88b3
sdaftuar:
utACK 79c02c88b3
achow101:
Code Review ACK 79c02c88b3
jamesob:
crACK 79c02c88b3
jonatack:
ACK 79c02c88b3
vasild:
ACK 79c02c88b3
theStack:
ACK 79c02c88b3
Tree-SHA512: 9a87c4dcad47c2d61b76c4f37f59674876b78f33f45943089bf159902a23e12de7a5feae1a73b17cbc3f2e37c980ecf0f7fd86af9e6fa3a68099537a3c82c106
This commit extends our inbound eviction protection to I2P peers to
favorise the diversity of peer connections, as peers connected
through the I2P network are otherwise disadvantaged by our eviction
criteria for their higher latency (higher min ping times) relative
to IPv4 and IPv6 peers, as well as relative to Tor onion 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 I2P candidates before localhost and onion ones
in terms of opportunity to recover unused remaining protected slots
from the previous iteration, guesstimating that most nodes allowing
both onion and I2P inbounds will have more onion peers, followed by
localhost, then I2P, as I2P support is only being added in the
upcoming v22.0 release.
with a more abstract framework to allow easily extending inbound
eviction protection to peers connected through new higher-latency
networks that are disadvantaged by our inbound eviction criteria,
such as I2P and perhaps other BIP155 networks in the future like
CJDNS. This is a change in behavior.
The algorithm is a basically a multi-pass knapsack:
- Count the number of eviction candidates in each of the disadvantaged
privacy networks.
- Sort the networks from lower to higher candidate counts, so that
a network with fewer candidates will have the first opportunity
for any unused slots remaining from the previous iteration. In
the case of a tie in candidate counts, priority is given by array
member order from first to last, guesstimated to favor more unusual
networks.
- Iterate through the networks in this order. On each iteration,
allocate each network an equal number of protected slots targeting
a total number of candidates to protect, provided any slots remain
in the knapsack.
- Protect the candidates in that network having the longest uptime,
if any in that network are present.
- Continue iterating as long as we have non-allocated slots
remaining and candidates available to protect.
Localhost peers are treated as a network like Tor or I2P by aliasing
them to an unused Network enumerator: Network::NET_MAX.
The goal is to favorise diversity of our inbound connections.
Credit to Vasil Dimov for improving the algorithm from single-pass
to multi-pass to better allocate unused protection slots.
Co-authored-by: Vasil Dimov <vd@FreeBSD.org>
as EraseLastKElements() called in the next line performs the same operation.
Thanks to Martin Zumsande (lightlike) for seeing this while reviewing.
Co-authored-by: Martin Zumsande <mzumsande@gmail.com>
