Some developers clearly don't get this and have been posting
"improvements" that create clear vulnerabilities. It should
have been better explained in the code, since the design
is somewhat subtle and getting it right is important.
DumpBanList currently does this:
- with lock: take a copy of the banmap
- perform I/O (write out the banmap)
- with lock: mark the banmap non-dirty
If a new ban is added during the I/O operation, it may never be persisted to
disk.
Reorder operations so that the data to be persisted cannot be older than the
time at which the banmap was marked non-dirty.
This will avoid sending more pointless INVs around updates, and
prevents using filter updates to timetag transactions.
Also adds locking for fRelayTxes.
By eliminating queued entries from the mempool response and responding only at
trickle time, this makes the mempool no longer leak transaction arrival order
information (as the mempool itself is also sorted)-- at least no more than
relay itself leaks it.
Note: Some seeds aren't actually returning an IP for their name entries, so
they're being added to addrman with a source of [::].
This commit shouldn't change that behavior, for better or worse.
Previously we used the CInv that would be sent to the peer announcing the
transaction as the key, but using the txid instead allows us to decouple the
p2p layer from the application logic (which relies on this map to avoid
duplicate tx requests).
The "feefilter" p2p message is used to inform other nodes of your mempool min fee which is the feerate that any new transaction must meet to be accepted to your mempool. This will allow them to filter invs to you according to this feerate.
027fdb8 When/if the copyright line does not mention Bitcoin Core developers, add a second line to copyrights in -version, About dialog, and splash screen (Luke Dashjr)
cc2095e Rewrite FormatParagraph to handle newlines within input strings correctly (Luke Dashjr)
cddffaf Bugfix: Include COPYRIGHT_HOLDERS_SUBSTITUTION in Makefile substitutions so it gets passed to extract-strings correctly (Luke Dashjr)
29598e4 Move PACKAGE_URL to configure.ac (Luke Dashjr)
78ec83d splashscreen: Resize text to fit exactly (Luke Dashjr)
3cae140 Bugfix: Actually use _COPYRIGHT_HOLDERS_SUBSTITUTION everywhere (Luke Dashjr)
4d5a3df Bugfix: gitian-descriptors: Add missing python-setuptools requirement for OS X (biplist module) (Luke Dashjr)
e4ab5e5 Bugfix: Correct copyright year in Mac DMG background image (Luke Dashjr)
917b1d0 Set copyright holders displayed in notices separately from the package name (Luke Dashjr)
c39a6ff Travis & gitian-osx: Use depends for ds_store and mac_alias modules (Luke Dashjr)
902ccde depends: Add mac_alias to depends (Luke Dashjr)
82a2d98 depends: Add ds_store to depends (Cory Fields)
de619a3 depends: Pass PYTHONPATH along to configure (Cory Fields)
e611b6e macdeploy: Use rsvg-convert rather than cairosvg (Luke Dashjr)
63bcdc5 More complicated package name substitution for Mac deployment (Luke Dashjr)
1a6c67c Parameterise 2009 in translatable copyright strings (Luke Dashjr)
d5f4683 Unify package name to as few places as possible without major changes (Luke Dashjr)
This corrects a bug the case of tying group size where the code may
fail to select the group with the newest member. Since newest time
is the final selection criteria, failing to break ties on it
on the step before can undermine the final selection.
Tied netgroups are very common.
(cherry picked from commit 8e09f914f8ec66301257358b250e9a61befadd95)
With automatic tor HS support in place we should probably not be providing
absolute protection for local peers, since HS inbound could be used to
attack pretty easily. Instead, this counts on the latency metric inside
AttemptToEvictConnection to privilege actually local peers.
(cherry picked from commit 46dbcd4833115401fecbb052365b4c7725874414)
e8600c9 banlist (bugfix): allow CNode::SweepBanned() to run on interval (Philip Kaufmann)
2977c24 banlist: add more banlist infos to log / add GUI signal (Philip Kaufmann)
ce479aa banlist: better handling of banlist in StartNode() (Philip Kaufmann)
57c77fe banlist: update set dirty to be more fine grained (Philip Kaufmann)
We used to have a trickle node, a node which was chosen in each iteration of
the send loop that was privileged and allowed to send out queued up non-time
critical messages. Since the removal of the fixed sleeps in the network code,
this resulted in fast and attackable treatment of such broadcasts.
This pull request changes the 3 remaining trickle use cases by random delays:
* Local address broadcast (while also removing the the wiping of the seen filter)
* Address relay
* Inv relay (for transactions; blocks are always relayed immediately)
The code is based on older commits by Patrick Strateman.
- Avoids string typos (by making the compiler check)
- Makes it easier to grep for handling/generation of a certain message type
- Refer directly to documentation by following the symbol in IDE
- Move list of valid message types to protocol.cpp:
protocol.cpp is a more appropriate place for this, and having
the array there makes it easier to keep things consistent.
aa4b0c2 When not filtering blocks, getdata sends more in one test (Pieter Wuille)
d41e44c Actually only use filterInventoryKnown with MSG_TX inventory messages. (Gregory Maxwell)
b6a0da4 Only use filterInventoryKnown with MSG_TX inventory messages. (Patick Strateman)
6b84935 Rename setInventoryKnown filterInventoryKnown (Patick Strateman)
e206724 Remove mruset as it is no longer used. (Gregory Maxwell)
ec73ef3 Replace setInventoryKnown with a rolling bloom filter. (Gregory Maxwell)
ebb25f4 Limit setAskFor and retire requested entries only when a getdata returns. (Gregory Maxwell)
5029698 prevent peer flooding request queue for an inv (kazcw)
Mruset setInventoryKnown was reduced to a remarkably small 1000
entries as a side effect of sendbuffer size reductions in 2012.
This removes setInventoryKnown filtering from merkleBlock responses
because false positives there are especially unattractive and
also because I'm not sure if there aren't race conditions around
the relay pool that would cause some transactions there to
be suppressed. (Also, ProcessGetData was accessing
setInventoryKnown without taking the required lock.)
The setAskFor duplicate elimination was too eager and removed entries
when we still had no getdata response, allowing the peer to keep
INVing and not responding.
mapAlreadyAskedFor does not keep track of which peer has a request queued for a
particular tx. As a result, a peer can blind a node to a tx indefinitely by
sending many invs for the same tx, and then never replying to getdatas for it.
Each inv received will be placed 2 minutes farther back in mapAlreadyAskedFor,
so a short message containing 10 invs would render that tx unavailable for 20
minutes.
This is fixed by disallowing a peer from having more than one entry for a
particular inv in mapAlreadyAskedFor at a time.
- Force AUTHCOOKIE size to be 32 bytes: This provides protection against
an attack where a process pretends to be Tor and uses the cookie
authentication method to nab arbitrary files such as the
wallet
- torcontrol logging
- fix cookie auth
- add HASHEDPASSWORD auth, fix fd leak when fwrite() fails
- better error reporting when cookie file is not ok
- better init/shutdown flow
- stop advertizing service when disconnected from tor control port
- COOKIE->SAFECOOKIE auth
Starting with Tor version 0.2.7.1 it is possible, through Tor's control socket
API, to create and destroy 'ephemeral' hidden services programmatically.
https://stem.torproject.org/api/control.html#stem.control.Controller.create_ephemeral_hidden_service
This means that if Tor is running (and proper authorization is available),
bitcoin automatically creates a hidden service to listen on, without user
manual configuration. This will positively affect the number of available
.onion nodes.
- When the node is started, connect to Tor through control socket
- Send `ADD_ONION` command
- First time:
- Make it create a hidden service key
- Save the key in the data directory for later usage
- Make it redirect port 8333 to the local port 8333 (or whatever port we're listening on).
- Keep control socket connection open for as long node is running. The hidden service will
(by default) automatically go away when the connection is closed.
* -maxuploadtarget can be set in MiB
* if <limit> - ( time-left-in-24h-cycle / 600 * MAX_BLOCK_SIZE ) has reach, stop serve blocks older than one week and filtered blocks
* no action if limit has reached, no guarantee that the target will not be surpassed
* add outbound limit informations to rpc getnettotals
Nagle appears to be a significant contributor to latency now that the static
sleeps are gone. Most of our messages are relatively large compared to
IP + TCP so I do not expect this to create enormous overhead.
This may also reduce traffic burstyness somewhat.
- to match the peers.dat handling also supply a debug.log entry for how
many entries were loaded from banlist.dat and how long it took
- add a GUI init message for loading the banlist (same as with peers.dat)
- move the same message for peers.dat upwards in the code, to be able to
reuse the timing variable nStart and also just log, if our read from
peers.dat didn't fail
- only start working on/with banlist data, if reading in the banlist from
disk didn't fail
- as CNode::setBannedIsDirty is false (default) when reading fails, we
don't need to explicitly set it to false to prevent writing
banlist.dat in that case either
`nMinPingUsecTime` was left uninitialized in CNode.
The correct initialization for a minimum-until-now is int64_t's max value, so initialize it to that.
Thanks @MarcoFalke for noticing.
027de94 Use network group instead of CNetAddr in final pass to select node to disconnect (Patrick Strateman)
000c18a Fix comment (Patrick Strateman)
fed3094 Acquire cs_vNodes before changing refrence counts (Patrick Strateman)
69ee1aa CNodeRef copy constructor and assignment operator (Patrick Strateman)
dc81dd0 Return false early if vEvictionCandidates is empty (Patrick Strateman)
17f3533 Better support for nodes with non-standard nMaxConnections (Patrick Strateman)
1317cd1 RAII wrapper for CNode* (Patrick Strateman)
df23937 Add comments to AttemptToEvictConnection (Patrick Strateman)
a8f6e45 Remove redundant whiteconnections option (Patrick Strateman)
b105ba3 Prefer to disconnect peers in favor of whitelisted peers (Patrick Strateman)
2c70153 AttemptToEvictConnection (Patrick Strateman)
4bac601 Record nMinPingUsecTime (Patrick Strateman)
ae037b7 Refactor: Move failure conditions to the top of AcceptConnection (Patrick Strateman)
1ef4817 Refactor: Bail early in AcceptConnection (Patrick Strateman)
541a1dd Refactor: AcceptConnection (Patrick Strateman)
When running the rpc tests in Wine, nodes often fail to listen on localhost
due to a stale socket from a previous run. This aligns the behavior with other
platforms.
7b79cbd limit total length of user agent comments (Pavol Rusnak)
557f8ea implement uacomment config parameter which can add comments to user agent as per BIP-0014 (Pavol Rusnak)
While CBloomFilter is usually used with an explicitly set nTweak,
CRollingBloomFilter is only used internally. Requiring every caller to
set nTweak is error-prone and redundant; better to have the class handle
that for you with a high-quality randomness source.
Additionally when clearing the filter it makes sense to change nTweak as
well to recover from a bad setting, e.g. due to insufficient randomness
at initialization, so the clear() method is replaced by a reset() method
that sets a new, random, nTweak value.
a794284 locking: add a quick example of GUARDED_BY (Cory Fields)
2b890dd locking: fix a few small issues uncovered by -Wthread-safety (Cory Fields)
cd27bba locking: teach Clang's -Wthread-safety to cope with our scoped lock macros (Cory Fields)
- rpcwallet: No need to lock twice here
- openssl: Clang doesn't understand selective lock/unlock here. Ignore it.
- CNode: Fix a legitimate (though very unlikely) locking bug.
This sets aside a number of connection slots for whitelisted peers,
useful for ensuring your local users and miners can always get in,
even if your limit on inbound connections has already been reached.
Use a probabilistic bloom filter to keep track of which addresses
we think we have given our peers, instead of a list.
This uses much less memory, at the cost of sometimes failing to
relay an address to a peer-- worst case if the bloom filter happens
to be as full as it gets, 1-in-1,000.
Measured memory usage of a full mruset setAddrKnown: 650Kbytes
Constant memory usage of CRollingBloomFilter addrKnown: 37Kbytes.
This will also help heap fragmentation, because the 37K of storage
is allocated when a CNode is created (when a connection to a peer
is established) and then there is no per-item-remembered memory
allocation.
I plan on testing by restarting a full node with an empty peers.dat,
running a while with -debug=addrman and -debug=net, and making sure
that the 'addr' message traffic out is reasonable.
(suggestions for better tests welcome)
1d21ba2 Scale up addrman (Pieter Wuille)
c6a63ce Always use a 50% chance to choose between tried and new entries (Pieter Wuille)
f68ba3f Do not bias outgoing connections towards fresh addresses (Pieter Wuille)
a8ff7c6 Simplify hashing code (Pieter Wuille)
e6b343d Make addrman's bucket placement deterministic. (Pieter Wuille)
b23add5 Switch addrman key from vector to uint256 (Pieter Wuille)
This change was suggested as Countermeasure 2 in
Eclipse Attacks on Bitcoin’s Peer-to-Peer Network, Ethan Heilman,
Alison Kendler, Aviv Zohar, Sharon Goldberg. ePrint Archive Report
2015/263. March 2015.
Normally bitcoin core does not display any network originated strings without
sanitizing or hex encoding. This wasn't done for strcommand in many places.
This could be used to play havoc with a terminal displaying the logs,
especially with printtoconsole in use.
Thanks to Evil-Knievel for reporting this issue.
856e862 namespace: drop most boost namespaces and a few header cleanups (Cory Fields)
9b1ab86 namespace: drop boost::assign altogether here (Cory Fields)
a324199 namespace: remove boost namespace pollution (Cory Fields)
This avoids connecting to them again too soon in ThreadOpenConnections.
Make an exception for connection failures to the proxy as these
shouldn't affect the status of specific nodes.
This is a simplified re-do of closed pull #3088.
This patch eliminates the privacy and reliability problematic use
of centralized web services for discovering the node's addresses
for advertisement.
The Bitcoin protocol already allows your peers to tell you what
IP they think you have, but this data isn't trustworthy since
they could lie. So the challenge is using it without creating a
DOS vector.
To accomplish this we adopt an approach similar to the one used
by P2Pool: If we're announcing and don't have a better address
discovered (e.g. via UPNP) or configured we just announce to
each peer the address that peer told us. Since peers could
already replace, forge, or drop our address messages this cannot
create a new vulnerability... but if even one of our peers is
giving us a good address we'll eventually make a useful
advertisement.
We also may randomly use the peer-provided address for the
daily rebroadcast even if we otherwise have a seemingly routable
address, just in case we've been misconfigured (e.g. by UPNP).
To avoid privacy problems, we only do these things if discovery
is enabled.
Many changes:
* Do not use 'getblocks', but 'getheaders', and use it to build a headers tree.
* Blocks are fetched in parallel from all available outbound peers, using a
limited moving window. When one peer stalls the movement of the window, it is
disconnected.
* No more orphan blocks. At all. We only ever request a block for which we have
verified the headers, and store it to disk immediately. This means that a
disk-fill attack would require PoW.
* Require protocol version 31800 for every peer (released in december 2010).
* No more syncnode (we sync from everyone we can, though limited to 1 during
initial *headers* sync).
* Introduce some extra named constants, comments and asserts.
Avoids that SOCKS5 negotiation will hold up the shutdown process.
- Sockets can stay in non-blocking mode, no need to switch it on/off
anymore
- Adds a timeout (20 seconds) on SOCK5 negotiation. This should be
enough for even Tor to get a connection to a hidden service, and
avoids blocking the opencon thread indefinitely on a hanging proxy.
Fixes#2954.
Split up util.cpp/h into:
- string utilities (hex, base32, base64): no internal dependencies, no dependency on boost (apart from foreach)
- money utilities (parsesmoney, formatmoney)
- time utilities (gettime*, sleep, format date):
- and the rest (logging, argument parsing, config file parsing)
The latter is basically the environment and OS handling,
and is stripped of all utility functions, so we may want to
rename it to something else than util.cpp/h for clarity (Matt suggested
osinterface).
Breaks dependency of sha256.cpp on all the things pulled in by util.
