Commit graph

565 commits

Author SHA1 Message Date
John Newbery
f52d403b81 [net] split PushInventory()
PushInventory() is currently called with a CInv object, which can be a
MSG_TX or MSG_BLOCK. PushInventory() only uses the type to determine
whether to add the hash to setInventoryTxToSend or
vInventoryBlockToSend.

Since the caller always knows what type of inventory they're pushing,
the CInv is wastefully constructed and thrown away, and tx/block relay
is being split out, we split the function into PushTxInventory() and
PushBlockInventory().
2020-06-18 15:45:48 -04:00
glowang
ec4c6a17e8 scripted-diff: replace MAX_BLOCKS_ONLY_CONNECTIONS with MAX_BLOCK_RELAY_ONLY_CONNECTIONS
-BEGIN VERIFY SCRIPT-
sed -i 's/\<MAX_BLOCKS_ONLY_CONNECTIONS\>/MAX_BLOCK_RELAY_ONLY_CONNECTIONS/g' src/init.cpp
sed -i 's/\<MAX_BLOCKS_ONLY_CONNECTIONS\>/MAX_BLOCK_RELAY_ONLY_CONNECTIONS/g' src/net.h
-END VERIFY SCRIPT-
2020-06-09 08:05:05 -07:00
MarcoFalke
55b4c65bd1
Merge #16127: More thread safety annotation coverage
5478d6c099 logging: thread safety annotations (Anthony Towns)
e685ca1992 util/system.cpp: add thread safety annotations for dir_locks (Anthony Towns)
a788789948 test/checkqueue_tests: thread safety annotations (Anthony Towns)
479c5846f7 rpc/blockchain.cpp: thread safety annotations for latestblock (Anthony Towns)
8b5af3d4c1 net: fMsgProcWake use LOCK instead of lock_guard (Anthony Towns)
de7c5f41ab wallet/wallet.h: Remove mutexScanning which was only protecting a single atomic bool (Anthony Towns)
c3cf2f5501 rpc/blockchain.cpp: Remove g_utxosetscan mutex that is only protecting a single atomic variable (Anthony Towns)

Pull request description:

  In a few cases we need to use `std::mutex` rather than the sync.h primitives. But `std::lock_guard<std::mutex>` doesn't include the clang thread safety annotations unless you also use clang's C library, which means you can't indicate when variables should be guarded by `std::mutex` mutexes.

  This adds an annotated version of `std::lock_guard<std::mutex>` to threadsafety.h to fix that, and modifies places where `std::mutex` is used to take advantage of the annotations.

  It's based on top of #16112, and turns the thread safety comments included there into annotations.

  It also changes the RAII classes in wallet/wallet.h and rpc/blockchain.cpp to just use the atomic<bool> flag for synchronisation rather than having a mutex that doesn't actually guard anything as well.

ACKs for top commit:
  MarcoFalke:
    ACK 5478d6c099 🗾
  hebasto:
    re-ACK 5478d6c099, only renamed s/`MutexGuard`/`LockGuard`/, and dropped the commit "test/util_threadnames_tests: add thread safety annotations" since the [previous](https://github.com/bitcoin/bitcoin/pull/16127#pullrequestreview-414184113) review.
  ryanofsky:
    Code review ACK 5478d6c099. Thanks for taking suggestions! Only changes since last review are dropping thread rename test commit d53072ec730d8eec5a5b72f7e65a54b141e62b19 and renaming mutex guard to lock guard

Tree-SHA512: 7b00d31f6f2b5a222ec69431eb810a74abf0542db3a65d1bbad54e354c40df2857ec89c00b4a5e466c81ba223267ca95f3f98d5fbc1a1d052a2c3a7d2209790a
2020-05-27 19:31:33 -04:00
Anthony Towns
8b5af3d4c1 net: fMsgProcWake use LOCK instead of lock_guard 2020-05-19 16:33:10 +10:00
tryphe
25d8264c95
p2p: add MAX_FEELER_CONNECTIONS constant 2020-05-12 17:30:33 +08:00
Sebastian Falbesoner
51e9393c1f refactor: s/command/msg_type/ in CNetMsgMaker and CSerializedNetMsg 2020-05-11 00:20:57 +02:00
Hennadii Stepanov
917ca93553
Make ThreadSafe{MessageBox|Question} bilingual 2020-05-05 04:45:59 +03:00
John Newbery
b8580cacc7 [net processing] Move net processing consts to net_processing.cpp 2020-04-23 12:54:03 -04:00
MarcoFalke
da4cbb7927
Merge #18544: net: limit BIP37 filter lifespan (active between 'filterload'..'filterclear')
a9ecbdfcaa test: add more inactive filter tests to p2p_filter.py (Sebastian Falbesoner)
5eae034996 net: limit BIP37 filter lifespan (active between 'filterload' and 'filterclear') (Sebastian Falbesoner)

Pull request description:

  This PR fixes https://github.com/bitcoin/bitcoin/issues/18483. On the master branch, there is currently _always_ a BIP37 filter set for every peer: if not a specific filter is set through a `filterload` message, a default match-everything filter is instanciated and pointed to via the `CBloomFilter` default constructor; that happens both initially, when the containing structure `TxRelay` is constructed:

  c0b389b335/src/net.h (L812)

  and after a loaded filter is removed again through a `filterclear` message:

  c0b389b335/src/net_processing.cpp (L3201)

  The behaviour was introduced by commit 37c6389c5a (an intentional covert fix for [CVE-2013-5700](https://github.com/bitcoin/bitcoin/pull/18515), according to gmaxwell).

  This default match-everything filter leads to some unintended side-effects:
  1. `getdata` request for filtered blocks (i.e. type `MSG_FILTERED_BLOCK`) are always responded to with `merkleblock`s, even if no filter was set by the peer, see issue #18483 (strictly speaking, this is a violation of BIP37) c0b389b335/src/net_processing.cpp (L1504-L1507)
  2. if a peer sends a `filteradd` message without having loaded a filter via `filterload` before, the intended increasing of the banscore never happens (triggered if `bad` is set to true, a few lines below) c0b389b335/src/net_processing.cpp (L3182-L3186)

  This PR basically activates the `else`-branch code paths for all checks of `pfilter` again (on the master branch, they are dead code) by limiting the pointer's lifespan: instead of always having a filter set, the `pfilter` is only pointing to a `CBloomFilter`-instance after receiving a `filterload` message and the instance is destroyed again (and the pointer nullified) after receiving a `filterclear` message.

  Here is a before/after comparison in behaviour:
  | code part / scenario                          |    master branch                   |   PR branch                                          |
  | --------------------------------------------- | ---------------------------------- | ---------------------------------------------------- |
  | `getdata` processing for `MSG_FILTERED_BLOCK` | always responds with `merkleblock` | only responds if filter was set via `filterload`     |
  | `filteradd` processing, no filter was loaded  | nothing                            | peer's banscore increases by 100 (i.e. disconnect)   |

  On the other code parts where `pfilter` is checked there is no change in the logic behaviour (except that `CBloomFilter::IsRelevantAndUpdate()` is unnecessarily called and immediately returned in the master branch).
  Note that the default constructor of `CBloomFilter` is only used for deserializing the received `filterload` message and nowhere else. The PR also contains a functional test checking that sending `getdata` for filtered blocks is ignored by the node if no bloom filter is set.

ACKs for top commit:
  MarcoFalke:
    re-ACK a9ecbdfcaa, only change is in test code 🕙

Tree-SHA512: 1a656a6d74ccaf628e7fdca063ba63fbab2089e0b6d0a11be9bbd387c2ee6d3230706ff8ffc1a55711481df3d4547137dd7c9d9184d89eaa43ade4927792d0b6
2020-04-20 06:59:53 -04:00
MarcoFalke
29893ec875
Merge #18454: net: Make addr relay mockable, add test
fa1da3d4bf test: Add basic addr relay test (MarcoFalke)
fa1793c1c4 net: Pass connman const when relaying address (MarcoFalke)
fa47a0b003 net: Make addr relay mockable (MarcoFalke)

Pull request description:

  As usual:

  * Switch to std::chrono time to be type-safe and mockable
  * Add basic test that relies on mocktime to add code coverage

ACKs for top commit:
  naumenkogs:
    utACK  fa1da3d
  promag:
    ACK fa1da3d4bf (fabe56e44b6f683e24e37246a7a8851190947cb3 before https://github.com/bitcoin/bitcoin/pull/18454#issuecomment-607866453), fa5bf23d527a450e72c2bf13d013e5393b664ca3 was dropped since last review.

Tree-SHA512: 0552bf8fcbe375baa3cab62acd8c23b2994efa47daff818ad1116d0ffaa0b9e520dc1bca2bbc68369b25584e85e54861fe6fd0968de4f503b95439c099df9bd7
2020-04-10 10:12:46 -04:00
Sebastian Falbesoner
5eae034996 net: limit BIP37 filter lifespan (active between 'filterload' and 'filterclear')
Previously, a default match-everything bloom filter was set for every peer,
i.e. even before receiving a 'filterload' message and after receiving a
'filterclear' message code branches checking for the existence of the filter
by testing the pointer "pfilter" were _always_ executed.
2020-04-09 11:26:24 +02:00
MarcoFalke
3410fe6887
Merge #18521: fuzz: Add process_messages harness
fa6a008434 fuzz: Add process_messages harness (MarcoFalke)

Pull request description:

ACKs for top commit:
  practicalswift:
    Tested ACK fa6a008434

Tree-SHA512: 2d8788308c7f45c97ca003378f58a9d51f51265958557a65e5e505b1666b4cb928f0d010622870175090a0ad25e2d10b41f26f4eef14b6ff334a024baa250f8c
2020-04-09 00:14:31 +08:00
MarcoFalke
fa6a008434
fuzz: Add process_messages harness 2020-04-05 10:46:24 +08:00
MarcoFalke
fa369651c5
net: Add missing cs_vNodes lock 2020-03-29 11:45:46 -04:00
MarcoFalke
fa47a0b003
net: Make addr relay mockable 2020-03-27 17:58:51 -04:00
Ben Woosley
7a810b1d7a
refactor: Convert ping wait time from double to int64_t 2020-03-04 13:45:29 -05:00
Ben Woosley
e6fc63ec7e
refactor: Convert min ping time from double to int64_t 2020-03-04 13:44:57 -05:00
Ben Woosley
b054c46977
refactor: Convert ping time from double to int64_t 2020-03-04 13:44:25 -05:00
MarcoFalke
eca4d8ef6a
Merge #16562: Refactor message transport packaging
16d6113f4f Refactor message transport packaging (Jonas Schnelli)

Pull request description:

  This PR factors out transport packaging logic from `CConnman::PushMessage()`.
  It's similar to #16202 (where we refactor deserialization).

  This allows implementing a new message transport protocol like BIP324.

ACKs for top commit:
  dongcarl:
    ACK 16d6113f4f FWIW
  ariard:
    Code review ACK 16d6113
  elichai:
    semiACK 16d6113f4f ran functional+unit tests.
  MarcoFalke:
    ACK 16d6113f4f 🙎

Tree-SHA512: 8c2f8ab9f52e9b94327973ae15019a08109d5d9f9247492703a842827c5b5d634fc0411759e0bb316d824c586614b0220c2006410851933613bc143e58f7e6c1
2020-02-28 17:01:58 -05:00
Pieter Wuille
6f8c937312 Mark asmap const in statistics code 2020-01-31 14:51:37 -08:00
Pieter Wuille
d58bcdc4b5 Avoid asmap copies in initialization 2020-01-31 14:51:37 -08:00
Wladimir J. van der Laan
01fc5891fb
Merge #16702: p2p: supplying and using asmap to improve IP bucketing in addrman
3c1bc40205 Add extra logging of asmap use and bucketing (Gleb Naumenko)
e4658aa8ea Return mapped AS in RPC call getpeerinfo (Gleb Naumenko)
ec45646de9 Integrate ASN bucketing in Addrman and add tests (Gleb Naumenko)
8feb4e4b66  Add asmap utility which queries a mapping (Gleb Naumenko)

Pull request description:

  This PR attempts to solve the problem explained in #16599.
  A particular attack which encouraged us to work on this issue is explained here  [[Erebus Attack against Bitcoin Peer-to-Peer Network](https://erebus-attack.comp.nus.edu.sg/)] (by @muoitranduc)

  Instead of relying on /16 prefix to diversify the connections every node creates, we would instead rely on the (ip -> ASN) mapping, if this mapping is provided.

  A .map file can be created by every user independently based on a router dump, or provided along with the Bitcoin release. Currently we use the python scripts written by @sipa to create a .map file, which is no larger than 2MB (awesome!).

  Here I suggest adding a field to peers.dat which would represent a hash of asmap file used while serializing addrman (or 0 for /16 prefix legacy approach).
  In this case, every time the file is updated (or grouping method changed), all buckets will be re-computed.
  I believe that alternative selective re-bucketing for only updated ranges would require substantial changes.

  TODO:
  - ~~more unit tests~~
  - ~~find a way to test the code without including >1 MB mapping file in the repo.~~
  - find a way to check that mapping file is not corrupted (checksum?)
  - comments and separate tests for asmap.cpp
  - make python code for .map generation public
  - figure out asmap distribution (?)

  ~Interesting corner case: I’m using std::hash to compute a fingerprint of asmap, and std::hash returns size_t. I guess  if a user updates the OS to 64-bit, then the hash of asap will change? Does it even matter?~

ACKs for top commit:
  laanwj:
    re-ACK 3c1bc40205
  jamesob:
    ACK 3c1bc40205 ([`jamesob/ackr/16702.3.naumenkogs.p2p_supplying_and_using`](https://github.com/jamesob/bitcoin/tree/ackr/16702.3.naumenkogs.p2p_supplying_and_using))
  jonatack:
    ACK 3c1bc40205

Tree-SHA512: e2dc6171188d5cdc2ab2c022fa49ed73a14a0acb8ae4c5ffa970172a0365942a249ad3d57e5fb134bc156a3492662c983f74bd21e78d316629dcadf71576800c
2020-01-29 13:55:43 +01:00
Gleb Naumenko
e4658aa8ea Return mapped AS in RPC call getpeerinfo
If ASN bucketing is used, return a corresponding AS
used in bucketing for a given peer.
2020-01-23 14:22:56 -05:00
Jonas Schnelli
16d6113f4f
Refactor message transport packaging 2020-01-22 14:55:24 -05:00
MarcoFalke
e09c701e01 scripted-diff: Bump copyright of files changed in 2020
-BEGIN VERIFY SCRIPT-
./contrib/devtools/copyright_header.py update ./
-END VERIFY SCRIPT-
2020-01-15 02:18:00 +07:00
MarcoFalke
6cbe620964 scripted-diff: Replace CCriticalSection with RecursiveMutex
-BEGIN VERIFY SCRIPT-
 # Delete outdated alias for RecursiveMutex
 sed -i -e '/CCriticalSection/d'                 ./src/sync.h
 # Replace use of outdated alias with RecursiveMutex
 sed -i -e 's/CCriticalSection/RecursiveMutex/g' $(git grep -l CCriticalSection)
-END VERIFY SCRIPT-
2020-01-15 01:43:46 +07:00
Russell Yanofsky
8313fa8e81 gui: Set CConnman byte counters earlier to avoid uninitialized reads
Initialize CConnman byte counters during construction, so GetTotalBytesRecv()
and GetTotalBytesSent() methods don't return garbage before Start() is called.

Change shouldn't have any effect outside of the GUI. It just fixes a race
condition during a qt test that was observed on travis:
https://travis-ci.org/bitcoin/bitcoin/jobs/634989685
2020-01-10 14:55:10 -05:00
Gleb Naumenko
ec45646de9 Integrate ASN bucketing in Addrman and add tests
Instead of using /16 netgroups to bucket nodes in Addrman for connection
diversification, ASN, which better represents an actor in terms
of network-layer infrastructure, is used.
For testing, asmap.raw is used. It represents a minimal
asmap needed for testing purposes.
2019-12-25 08:59:08 -05:00
MarcoFalke
c7e6b3b343
Merge #17243: p2p: add PoissonNextSend method that returns mockable time
1a8f0d5a74 [tools] update nNextInvSend to use mockable time (Amiti Uttarwar)
4de630354f [tools] add PoissonNextSend method that returns mockable time (Amiti Uttarwar)

Pull request description:

  Introduce a Poisson helper method that wraps the existing method to return `std::chrono::duration` type, which is mockable.

  Needed for https://github.com/bitcoin/bitcoin/pull/16698.

ACKs for top commit:
  ajtowns:
    ACK 1a8f0d5a74
  MarcoFalke:
    re-ACK 1a8f0d5a74
  naumenkogs:
    ACK 1a8f0d5, and let's merge it and come back to it later.

Tree-SHA512: 7e2325d7c55fc0b4357cb86b83e0c218ba269f678c1786342d8bc380bfd9696373bc24ff124b9ff17a6e761c62b2b44ff5247c3911e2afdc7cc5c20417e8290b
2019-11-05 12:38:28 -05:00
Amiti Uttarwar
1a8f0d5a74 [tools] update nNextInvSend to use mockable time 2019-11-05 11:12:10 +01:00
Amiti Uttarwar
4de630354f [tools] add PoissonNextSend method that returns mockable time 2019-11-05 11:06:53 +01:00
MarcoFalke
8f9df2ed88
Merge #17164: p2p: Avoid allocating memory for addrKnown where we don't need it
b6d2183858 Minor refactoring to remove implied m_addr_relay_peer. (User)
a552e8477c added asserts to check m_addr_known when it's used (User)
090b75c14b p2p: Avoid allocating memory for addrKnown where we don't need it (User)

Pull request description:

  We should allocate memory for addrKnown filter only for those peers which are expected to participate in address relay.

  Currently, we do it for all peers (including SPV and block-relay-only),  which results in extra RAM where it's not needed.

  Upd:
  In future, we would still allow SPVs to ask for addrs, so allocation still will be done by default.
  However, they will be able to opt-out via [this proposal](https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-October/017428.html) and then we could save some more memory.
  This PR still saves memory for block-relay-only peers immediately after merging.

Top commit has no ACKs.

Tree-SHA512: e84d93b2615556d466f5ca0e543580fde763911a3bfea3127c493ddfaba8f05c8605cb94ff795d165af542b594400995a2c51338185c298581408687e7812463
2019-11-04 11:17:20 -05:00
User
b6d2183858 Minor refactoring to remove implied m_addr_relay_peer.
Co-authored-by: MarcoFalke <falke.marco@gmail.com>
2019-10-31 13:42:02 -04:00
Russell Yanofsky
8922d7f6b7 scripted-diff: Remove g_connman, g_banman globals
-BEGIN VERIFY SCRIPT-
sed -i 's:#include <interfaces/chain.h>:#include <banman.h>\n#include <interfaces/chain.h>\n#include <net.h>\n#include <net_processing.h>:' src/node/context.cpp
sed -i 's/namespace interfaces {/class BanMan;\nclass CConnman;\nclass PeerLogicValidation;\n&/' src/node/context.h
sed -i 's/std::unique_ptr<interfaces::Chain> chain/std::unique_ptr<CConnman> connman;\n    std::unique_ptr<PeerLogicValidation> peer_logic;\n    std::unique_ptr<BanMan> banman;\n    &/' src/node/context.h
sed -i '/std::unique_ptr<[^>]\+> \(g_connman\|g_banman\|peerLogic\);/d' src/banman.h src/net.h src/init.cpp
sed -i 's/g_connman/m_context.connman/g' src/interfaces/node.cpp
sed -i 's/g_banman/m_context.banman/g' src/interfaces/node.cpp
sed -i 's/g_connman/m_node.connman/g' src/interfaces/chain.cpp src/test/setup_common.cpp
sed -i 's/g_banman/m_node.banman/g' src/test/setup_common.cpp
sed -i 's/g_connman/node.connman/g' src/init.cpp src/node/transaction.cpp
sed -i 's/g_banman/node.banman/g' src/init.cpp
sed -i 's/peerLogic/node.peer_logic/g' src/init.cpp
sed -i 's/g_connman/g_rpc_node->connman/g' src/rpc/mining.cpp src/rpc/net.cpp src/rpc/rawtransaction.cpp
sed -i 's/g_banman/g_rpc_node->banman/g' src/rpc/net.cpp
sed -i 's/std::shared_ptr<CWallet> wallet =/node.context()->connman = std::move(test.m_node.connman);\n    &/' src/qt/test/wallettests.cpp
-END VERIFY SCRIPT-
2019-10-28 10:30:51 -04:00
User
a552e8477c added asserts to check m_addr_known when it's used 2019-10-25 16:28:14 -04:00
Pieter Wuille
ed2dc5e48a
Add override/final modifiers to V1TransportDeserializer 2019-10-23 09:27:35 +02:00
Pieter Wuille
f342a5e61a
Make resetting implicit in TransportDeserializer::Read() 2019-10-23 09:27:32 +02:00
Pieter Wuille
6a91499496
Remove oversized message detection from log and interface 2019-10-23 09:27:25 +02:00
Jonas Schnelli
b0e10ff4df
Force CNetMessage::m_recv to use std::move 2019-10-22 15:28:32 +02:00
Jonas Schnelli
efecb74677
Use adapter pattern for the network deserializer 2019-10-18 08:56:08 +02:00
Jonas Schnelli
1a5c656c31
Remove transport protocol knowhow from CNetMessage / net processing 2019-10-18 08:56:08 +02:00
Jonas Schnelli
6294ecdb8b
Refactor: split network transport deserializing from message container 2019-10-18 08:56:06 +02:00
User
090b75c14b p2p: Avoid allocating memory for addrKnown where we don't need it 2019-10-16 17:06:20 -04:00
MarcoFalke
faec689bed
txmempool: Make entry time type-safe (std::chrono) 2019-09-23 08:00:14 -04:00
James O'Beirne
82e53f37e1 doc: add comments clarifying how local services are advertised
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.
2019-09-11 10:24:44 -04:00
fanquake
189c19e012
Merge #15759: p2p: Add 2 outbound block-relay-only connections
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
2019-09-07 17:45:03 +08:00
Suhas Daftuar
430f489027 Don't relay addr messages to block-relay-only peers
We don't want relay of addr messages to leak information about
these network links.
2019-09-04 14:58:36 -04:00
Suhas Daftuar
3a5e885306 Add 2 outbound block-relay-only connections
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).)
2019-09-04 14:58:36 -04:00
Suhas Daftuar
b83f51a4bb Add comment explaining intended use of m_tx_relay 2019-09-04 14:58:36 -04:00
Suhas Daftuar
e75c39cd42 Check that tx_relay is initialized before access 2019-09-04 14:58:34 -04:00
Suhas Daftuar
c4aa2ba822 [refactor] Change tx_relay structure to be unique_ptr 2019-08-28 13:41:58 -04:00
Suhas Daftuar
4de0dbac9b [refactor] Move tx relay state to separate structure 2019-08-28 13:41:58 -04:00
nicolas.dorier
ce7eac3cb0
[Fix] The default whitelistrelay should be true 2019-08-17 00:43:22 +09:00
Suhas Daftuar
26a93bce29 Remove unused variable 2019-08-14 13:40:49 -04:00
nicolas.dorier
d541fa3918
Replace the use of fWhitelisted by permission checks 2019-08-11 11:33:28 +09:00
nicolas.dorier
e5b26deaaa
Make whitebind/whitelist permissions more flexible 2019-08-11 11:33:27 +09:00
MarcoFalke
fa1dce7329
net: Rename ::fRelayTxes to ::g_relay_txes
This helps to distinguish it from CNode::fRelayTxes and avoid bugs like
425278d17b
2019-05-09 09:10:53 -04:00
MarcoFalke
c83442e174
Merge #15654: net: Remove unused unsanitized user agent string CNode::strSubVer
fa8548c5d1 net: Remove unused unsanitized user agent string CNode::strSubVer (MarcoFalke)

Pull request description:

  I fail to see a use case for this unsanitized byte array. In fact this can easily be confused with `cleanSubVer` and be displayed to the user (or logged) by a simple typo that is hard to find in review.

  Further reading: https://btcinformation.org/en/developer-reference#version

ACKs for commit fa8548:
  promag:
    utACK fa8548c, good catch.
  practicalswift:
    utACK fa8548c5d1
  sipa:
    utACK fa8548c5d1

Tree-SHA512: 3c3ff1504d1583ad099df9a6aa761458a82ec48a58ef7aaa9b5679a5281dd1b59036ba2932ed708488951a565b669a3083ef70be5a58472ff8677b971162ae2f
2019-04-04 16:45:23 -04:00
MarcoFalke
fa8548c5d1
net: Remove unused unsanitized user agent string CNode::strSubVer 2019-03-23 11:32:40 -04:00
Pieter Wuille
866c8058a7 Interrupt orphan processing after every transaction
This makes orphan processing work like handling getdata messages:
After every actual transaction validation attempt, interrupt
processing to deal with messages arriving from other peers.
2019-03-22 19:25:50 -07:00
MarcoFalke
30495d1e75
Merge #15201: net: Add missing locking annotation for vNodes. vNodes is guarded by cs_vNodes.
eea02be70e Add locking annotation for vNodes. vNodes is guarded by cs_vNodes. (practicalswift)

Pull request description:

  Add locking annotation for `vNodes`. `vNodes` is guarded by `cs_vNodes`.

Tree-SHA512: b1e18be22ba5b9dd153536380321b09b30a75a20575f975af9af94164f51982b32267ba0994e77c801513b59da05d923a974a9d2dfebdac48024c4bda98b53af
2019-02-08 08:58:29 -05:00
Gleb Naumenko
1cff3d6cb0 Change in transaction pull scheduling to prevent InvBlock-related attacks
Co-authored-by: Suhas Daftuar <sdaftuar@gmail.com>
2019-02-06 20:25:27 -08:00
Jonas Schnelli
2d790e82c8
Merge #14929: net: Allow connections from misbehavior banned peers
0297be61a Allow connections from misbehavior banned peers. (Gregory Maxwell)

Pull request description:

  This allows incoming connections from peers which are only banned
   due to an automatic misbehavior ban if doing so won't fill inbound.

  These peers are preferred for eviction when inbound fills, but may
   still be kept if they fall into the protected classes.  This
   eviction preference lasts the entire life of the connection even
   if the ban expires.

  If they misbehave again they'll still get disconnected.

  The main purpose of banning on misbehavior is to prevent our
   connections from being wasted on unhelpful peers such as ones
   running incompatible consensus rules.  For inbound peers this
   can be better accomplished with eviction preferences.

  A secondary purpose was to reduce resource waste from repeated
   abuse but virtually any attacker can get a nearly unlimited
   supply of addresses, so disconnection is about the best we can
   do.

  This can reduce the potential from negative impact due to incorrect misbehaviour bans.

Tree-SHA512: 03bc8ec8bae365cc437daf70000c8f2edc512e37db821bc4e0fafa6cf56cc185e9ab40453aa02445f48d6a2e3e7268767ca2017655aca5383108416f1e2cf20f
2019-01-29 13:41:04 -10:00
Ben Woosley
9431e1b915
Trivial: fixup a few doxygen comments
These were not declared properly, so their results are not properly
processed. E.g.:
https://dev.visucore.com/bitcoin/doxygen/rpcdump_8cpp.html#a994c8748aaa60fbb78009ff8a0638dea
https://dev.visucore.com/bitcoin/doxygen/coins_8cpp.html#aa03af24ef3570144b045f4fca7a0d603
https://dev.visucore.com/bitcoin/doxygen/wallet_2wallet_8cpp.html#a5c2a7725ff8796f03471f844ecded3d9
2019-01-24 19:47:07 -08:00
Gregory Maxwell
0297be61ac Allow connections from misbehavior banned peers.
This allows incoming connections from peers which are only banned
 due to an automatic misbehavior ban if doing so won't fill inbound.

These peers are preferred for eviction when inbound fills, but may
 still be kept if they fall into the protected classes.  This
 eviction preference lasts the entire life of the connection even
 if the ban expires.

If they misbehave again they'll still get disconnected.

The main purpose of banning on misbehavior is to prevent our
 connections from being wasted on unhelpful peers such as ones
 running incompatible consensus rules.  For inbound peers this
 can be better accomplished with eviction preferences.

A secondary purpose was to reduce resource waste from repeated
 abuse but virtually any attacker can get a nearly unlimited
 supply of addresses, so disconnection is about the best we can
 do.
2019-01-22 21:10:48 +00:00
Wladimir J. van der Laan
5baa9092c4
Merge #14605: Return of the Banman
18185b57c3 scripted-diff: batch-recase BanMan variables (Carl Dong)
c2e04d37f3 banman: Add, use CBanEntry ctor that takes ban reason (Carl Dong)
1ffa4ce27d banman: reformulate nBanUtil calculation (Carl Dong)
daae598feb banman: add thread annotations and mark members const where possible (Cory Fields)
84fc3fbd03 scripted-diff: batch-rename BanMan members (Cory Fields)
af3503d903 net: move BanMan to its own files (Cory Fields)
d0469b2e93 banman: pass in default ban time as a parameter (Cory Fields)
2e56702ece banman: pass the banfile path in (Cory Fields)
4c0d961eb0 banman: create and split out banman (Cory Fields)
83c1ea2e5e net: split up addresses/ban dumps in preparation for moving them (Cory Fields)
136bd7926c tests: remove member connman/peerLogic in TestingSetup (Cory Fields)
7cc2b9f678 net: Break disconnecting out of Ban() (Cory Fields)

Pull request description:

  **Old English à la Beowulf**
  ```
  Banman wæs bréme    --blaéd wíde sprang--
  Connmanes eafera    Coreum in.
  aéglaéca            léodum forstandan
  Swá bealdode        bearn Connmanes
  guma gúðum cúð      gódum daédum·
  dréah æfter dóme·   nealles druncne slóg
  ```

  **Modern English Translation**
  ```
  Banman was famed              --his renown spread wide--
  Conman's hier,                in Core-land.
  against the evil creature     defend the people
  Thus he was bold,             the son of Connman
  man famed in war,             for good deeds;
  he led his life for glory,    never, having drunk, slew
  ```

  --

  With @theuni's blessing, here is Banman, rebased. Original PR: https://github.com/bitcoin/bitcoin/pull/11457

  --

  Followup PRs:
  1. Give `CNode` a `Disconnect` method ([source](https://github.com/bitcoin/bitcoin/pull/14605#discussion_r248065847))
  2. Add a comment to `std::atomic_bool fDisconnect` in `net.h` that setting this to true will cause the node to be disconnected the next time `DisconnectNodes()` runs ([source](https://github.com/bitcoin/bitcoin/pull/14605#discussion_r248384309))

Tree-SHA512: 9c207edbf577415c22c9811113e393322d936a843d4ff265186728152a67c057779ac4d4f27b895de9729f7a53e870f828b9ebc8bcdab757520c2aebe1e9be35
2019-01-21 18:58:52 +01:00
practicalswift
eea02be70e Add locking annotation for vNodes. vNodes is guarded by cs_vNodes. 2019-01-19 18:23:53 +01:00
Carl Dong
5b4283cb81 Add comment describing fDisconnect behavior 2019-01-17 18:27:13 -05:00
Cory Fields
af3503d903 net: move BanMan to its own files 2019-01-16 13:54:18 -05:00
Cory Fields
d0469b2e93 banman: pass in default ban time as a parameter
Removes the dependency on arg parsing.
2019-01-16 13:54:18 -05:00
Cory Fields
2e56702ece banman: pass the banfile path in
There's no need to hard-code the path here. Passing it in means that there are
no ordering concerns wrt establishing the datadir.
2019-01-16 13:54:18 -05:00
Cory Fields
4c0d961eb0 banman: create and split out banman
Some say he has always been.
2019-01-16 13:54:18 -05:00
Cory Fields
7cc2b9f678 net: Break disconnecting out of Ban()
These are separate events which need to be carried out by separate subsystems.

This also cleans up some whitespace and tabs in qt to avoid getting flagged by
the linter.

Current behavior is preserved.
2019-01-16 11:04:05 -05:00
Wladimir J. van der Laan
070eaf7fe5
Merge #15144: [refactor] CNode: Use C++11 default member initializers
fac2f5ecae Use C++11 default member initializers (MarcoFalke)

Pull request description:

  The second and last change on this topic (c.f. #15109). Split up because the diff would otherwise interleave, making review harder than necessary.

  This is not a stylistic change, but a change that avoids bugs such as:

  *  fix uninitialized read when stringifying an addrLocal #14728
  *  qt: Initialize members in WalletModel #12426
  *  net: correctly initialize nMinPingUsecTime #6636
  * ...

Tree-SHA512: 547ae72b87aeaed5890eb5fdcff612bfc93354632b238d89e1e1c0487187f39609bcdc537ef21345e0aea8cfcf1ea48da432d672c5386dd87cf58742446a86b1
2019-01-14 14:48:51 +01:00
Ben Woosley
d6b076c17b
Drop IsLimited in favor of IsReachable
These two methods have had the same meaning, but inverted, since
110b62f069. Having one name for a single
concept simplifies the code.
2019-01-13 22:50:36 -08:00
MarcoFalke
fac2f5ecae
Use C++11 default member initializers 2019-01-10 14:55:45 -05:00
Wladimir J. van der Laan
3f12515199
Merge #15109: refactor: Use C++11 default member initializers
fa2510d5c1 Use C++11 default member initializers (MarcoFalke)

Pull request description:

  Changes:
  * Remove unused constructors that leave some members uninitialized
  * Remove manual initialization in each constructor and prefer C++11 default member initializers

  This is not a stylistic change, but a change that avoids bugs such as:

  *  fix uninitialized read when stringifying an addrLocal #14728
  *  qt: Initialize members in WalletModel #12426
  *  net: correctly initialize nMinPingUsecTime #6636
  * ...

Tree-SHA512: 0f896f3b9fcc464d5fc7525f7c86343ef9ce9fb13425fbc68e9a9728fd8710c2b4e2fd039ee08279ea41ff20fd92b7185cf5cca95a0bcb6a5340a1e6f03cae6b
2019-01-09 15:04:36 +01:00
MarcoFalke
fa2510d5c1
Use C++11 default member initializers 2019-01-05 16:16:37 +01:00
MarcoFalke
fab3f14678
rpc: Document bytessent_per_msg and bytesrecv_per_msg 2019-01-03 15:49:24 +01:00
Wladimir J. van der Laan
62cf608e93
Merge #14336: net: implement poll
4927bf2f25 Increase maxconnections limit when using poll. (Patrick Strateman)
11cc491a28 Implement poll() on systems which support it properly. (Patrick Strateman)
28211a4bc9 Move SocketEvents logic to private method. (Patrick Strateman)
7e403c0ae7 Move GenerateSelectSet logic to private method. (Patrick Strateman)
1e6afd0dbc Introduce and use constant SELECT_TIMEOUT_MILLISECONDS. (Patrick Strateman)

Pull request description:

  Implement poll() on systems which support it properly.

  This eliminates the restriction on maximum socket descriptor number.

Tree-SHA512: b945cd9294afdafcce96d547f67679d5cdd684cf257904a239cd1248de3b5e093b8d6d28d8d1b7cc923dc0b2b5723faef9bc9bf118a9ce1bdcf357c2323f5573
2019-01-02 13:14:45 +01:00
Wladimir J. van der Laan
88445889f1
Merge #14733: P2P: Make peer timeout configurable, speed up very slow test and ensure correct code path tested.
48b37db50 make peertimeout a debug argument, remove error message translation (Zain Iqbal Allarakhia)
8042bbfbf p2p: allow p2ptimeout to be configurable, speed up slow test (Zain Iqbal Allarakhia)

Pull request description:

  **Summary:**

  1. _Primary_: Adds a `debug_only=true` flag for peertimeout, defaults to 60 sec., the current hard-coded setting.
  2. _Secondary_: Drastically speeds up `p2p_timeout.py` test.
  3. _Secondary_: Tests that the correct code path is being tested by adding log assertions to the test.

  **Rationale:**

  - P2P timeout was hard-coded: make it explicitly specified and configurable, instead of a magic number.
  - Addresses #13518; `p2p_timeout.py` takes 4 sec. to run instead of 61 sec.
  - Makes `p2p_timeout.py` more explicit. Previously, we relied on a comment to inform us of the timeout amount being tested. Now it is specified directly in the test via passing in the new arg; `-peertimeout=3`.
  - Opens us up to testing more P2P scenarios; oftentimes slow tests are the reason we don't test.

  **Locally verified changes:**

  _With Proposed Change (4.7 sec.):_
  ```
  $ time ./test/functional/p2p_timeouts.py
  2018-11-19T00:04:19.077000Z TestFramework (INFO): Initializing test directory /tmp/testhja7g2n7
  2018-11-19T00:04:23.479000Z TestFramework (INFO): Stopping nodes
  2018-11-19T00:04:23.683000Z TestFramework (INFO): Cleaning up /tmp/testhja7g2n7 on exit
  2018-11-19T00:04:23.683000Z TestFramework (INFO): Tests successful

  real    0m4.743s
  ```

  _Currently  on master (62.8 sec.):_
  ```
  $ time ./test/functional/p2p_timeouts.py
  2018-11-19T00:06:10.948000Z TestFramework (INFO): Initializing test directory /tmp/test6mo6k21h
  2018-11-19T00:07:13.376000Z TestFramework (INFO): Stopping nodes
  2018-11-19T00:07:13.631000Z TestFramework (INFO): Cleaning up /tmp/test6mo6k21h on exit
  2018-11-19T00:07:13.631000Z TestFramework (INFO): Tests successful

  real    1m2.836s
  ```

  _Error message demonstrated for new argument `-peertimeout`:_
  ```
  $ ./bitcoind -peertimeout=-5
  ...
  Error: peertimeout cannot be configured with a negative value.
  ```

Tree-SHA512: ff7a244ebea54c4059407bf4fb86465714e6a79cef5d2bcaa22cfe831a81761aaf597ba4d5172fc2ec12266f54712216fc41b5d24849e5d9dab39ba6f09e3a2a
2018-12-04 12:58:02 +01:00
Patrick Strateman
28211a4bc9 Move SocketEvents logic to private method.
This separates the select() logic from the socket handling logic, setting up
for a switch to poll().
2018-11-30 18:02:51 -05:00
Patrick Strateman
7e403c0ae7 Move GenerateSelectSet logic to private method.
This separates the socket event collection logic from the logic
deciding which events we're interested in at all.
2018-11-30 18:02:51 -05:00
Zain Iqbal Allarakhia
8042bbfbf0 p2p: allow p2ptimeout to be configurable, speed up slow test 2018-11-28 16:41:15 -08:00
practicalswift
b312cd7707 Add missing locking annotations 2018-11-28 09:36:25 +01:00
MarcoFalke
fa71eb5196
Convert comments to thread safety annotations 2018-11-20 20:29:16 -05:00
Jim Posen
4fb789e9b2 Extract CSipHasher to it's own file in crypto/ directory.
This is a move-only commit with the exception of changes to includes.
2018-11-05 09:25:15 -08:00
Wladimir J. van der Laan
23419e4c49
Merge #14335: net: refactor: cleanup ThreadSocketHandler
032488e6e7 Move SocketHandler logic to private method. (Patrick Strateman)
2af9cff11a Move InactivityCheck logic to private method. (Patrick Strateman)
7479b63d91 Move DisconnectNodes logic to private method. (Patrick Strateman)
edb5350c32 Move NotifyNumConnectionsChanged logic to private method. (Patrick Strateman)

Pull request description:

  Working towards using poll() on unix like systems.

  A number of small changes designed to separate the actual socket handling from the rest of the logic in ThreadSocketHandler.

  This is a simpler version of #14147

Tree-SHA512: 72f35c8ef7649019dcbfe19537d8c9f7e3d0fc5854dc691a70c5573352230fc31c3f55565820c632e9b8cb3c55b878bed19e0ad9423100762197ac35967d8067
2018-10-16 17:20:34 +02:00
MarcoFalke
423cb37658
Merge #14027: Skip stale tip checking if outbound connections are off or if reindexing.
66b3fc5437 Skip stale tip checking if outbound connections are off or if reindexing. (Gregory Maxwell)

Pull request description:

  I got tired of the pointless stale tip notices in reindex and on nodes with connections disabled.

Tree-SHA512: eb07d9c5c787ae6dea02cdd1d67a48a36a30adc5ccc74d6f1c0c7364d404dc8848b35d2b8daf5283f7c8f36f1a3c463aacb190d70a22d1fe796a301bb1f03228
2018-09-27 11:18:47 -04:00
Patrick Strateman
032488e6e7 Move SocketHandler logic to private method. 2018-09-24 17:08:10 -04:00
Patrick Strateman
2af9cff11a Move InactivityCheck logic to private method. 2018-09-24 17:08:04 -04:00
Patrick Strateman
7479b63d91 Move DisconnectNodes logic to private method. 2018-09-24 16:53:52 -04:00
Patrick Strateman
edb5350c32 Move NotifyNumConnectionsChanged logic to private method. 2018-09-24 16:30:53 -04:00
Russell Yanofsky
190bf62be1 scripted-diff: Small locking rename
Call sync.h primitives "locks" and "mutexes" instead of "blocks" and "waitable
critical sections" to match current coding conventions and c++11 standard
names.

This PR does not rename the "CCriticalSection" class (though this could be done
as a followup) because it is used everywhere and would swamp the other changes
in this PR. Plain mutexes should mostly be preferred instead of recursive
mutexes in new code anyway.

-BEGIN VERIFY SCRIPT-
set -x
set -e
ren() { git grep -l $1 | xargs sed -i s/$1/$2/; }
ren CCriticalBlock           UniqueLock
ren CWaitableCriticalSection Mutex
ren CConditionVariable       std::condition_variable
ren cs_GenesisWait           g_genesis_wait_mutex
ren condvar_GenesisWait      g_genesis_wait_cv
perl -0777 -pi -e 's/.*typedef.*condition_variable.*\n\n?//g' src/sync.h
-END VERIFY SCRIPT-
2018-08-31 10:00:38 -04:00
Wladimir J. van der Laan
385ad11040
Merge #11640: Make LOCK, LOCK2, TRY_LOCK work with CWaitableCriticalSection
9c4dc597dd Use LOCK macros for non-recursive locks (Russell Yanofsky)
1382913e61 Make LOCK, LOCK2, TRY_LOCK work with CWaitableCriticalSection (Russell Yanofsky)
ba1f095aad MOVEONLY Move AnnotatedMixin declaration (Russell Yanofsky)
41b88e9337 Add unit test for DEBUG_LOCKORDER code (Russell Yanofsky)

Pull request description:

  Make LOCK macros work with non-recursive mutexes, and use wherever possible for better deadlock detection.

  Also add unit test for DEBUG_LOCKORDER code.

Tree-SHA512: 64ef209307f28ecd0813a283f15c6406138c6ffe7f6cbbd084161044db60e2c099a7d0d2edcd1c5e7770a115e9b931b486e86c9a777bdc96d2e8a9f4dc192942
2018-08-31 16:00:38 +02:00
Anthony Towns
5778bf95d9 Report minfeefilter value in getpeerinfo rpc
Lowering the minimum relay fee is only useful when many nodes in the
p2p network also lower the fee, so to make it easier to understand
progress on that front, this includes the value of the minfeefilter in
getpeerinfo, so you at least have visibility to what fees your neighbours
are currently accepting.
2018-08-27 21:13:15 +10:00
Gregory Maxwell
66b3fc5437 Skip stale tip checking if outbound connections are off or if reindexing. 2018-08-23 10:10:12 +00:00
Wladimir J. van der Laan
48bf8ff5b1
Merge #13907: Introduce a maximum size for locators.
e254ff5d53 Introduce a maximum size for locators. (Gregory Maxwell)

Pull request description:

  The largest sensible size for a locator is log in the number of blocks.
   But, as noted by Coinr8d on BCT a maximum size message could encode a
   hundred thousand locators.  If height were used to limit the messages
   that could open new attacks where peers on long low diff forks would
   get disconnected and end up stuck.

  Ideally, nodes first first learn to limit the size of locators they
   send before limiting what would be processed, but common implementations
   back off with an exponent of 2 and have an implicit limit of 2^32
   blocks, so they already cannot produce locators over some size.

  Locators are cheap to process so allowing a few more is harmless,
   so this sets the maximum to 64-- which is enough for blockchains
   with 2^64 blocks before the get overhead starts increasing.

Tree-SHA512: da28df9c46c988980da861046c62e6e7f93d0eaab3083d32e408d1062f45c00316d5e1754127e808c1feb424fa8e00e5a91aea2cc3b80326b71c148696f7cdb3
2018-08-10 19:52:13 +02:00
Gregory Maxwell
e254ff5d53 Introduce a maximum size for locators.
The largest sensible size for a locator is log in the number of blocks.
 But, as noted by Coinr8d on BCT a maximum size message could encode a
 hundred thousand locators.  If height were used to limit the messages
 that could open new attacks where peers on long low diff forks would
 get disconnected and end up stuck.

Ideally, nodes first first learn to limit the size of locators they
 send before limiting what would be processed, but common implementations
 back off with an exponent of 2 and have an implicit limit of 2^32
 blocks, so they already cannot produce locators over some size.

This sets the limit to an absurdly high amount of 101 in order to
 maximize compatibility with existing software.
2018-08-09 20:54:01 +00:00
Wladimir J. van der Laan
78dae8cacc
Merge #13780: 0.17: Pre-branch maintenance
3fc20632a3 qt: Set BLOCK_CHAIN_SIZE = 220 (DrahtBot)
2b6a2f4a28 Regenerate manpages (DrahtBot)
eb7daf4d60 Update copyright headers to 2018 (DrahtBot)

Pull request description:

  Some trivial maintenance to avoid having to do it again after the 0.17 branch off.

  (The scripts to do this are in `./contrib/`)

Tree-SHA512: 16b2af45e0351b1c691c5311d48025dc6828079e98c2aa2e600dc5910ee8aa01858ca6c356538150dc46fe14c8819ed8ec8e4ec9a0f682b9950dd41bc50518fa
2018-08-08 13:55:27 +02:00