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.
- the call to CloseSocket() is placed after the WSAGetLastError(), because
a CloseSocket() can trigger an error also, which we don't want for the
logging in this two cases
Simpler alternative to #4348.
The current setup with closesocket() is strange. It poses
as a compatibility wrapper but adds functionality.
Rename it and make it a documented utility function in netbase.
Code movement only, zero effect on the functionality.
This adds a -whitelist option to specify subnet ranges from which peers
that connect are whitelisted. In addition, there is a -whitebind option
which works like -bind, except peers connecting to it are also
whitelisted (allowing a separate listen port for trusted connections).
Being whitelisted has two effects (for now):
* They are immune to DoS disconnection/banning.
* Transactions they broadcast (which are valid) are always relayed,
even if they were already in the mempool. This means that a node
can function as a gateway for a local network, and that rebroadcasts
from the local network will work as expected.
Whitelisting replaces the magic exemption localhost had for DoS
disconnection (local addresses are still never banned, though), which
implied hidden service connects (from a localhost Tor node) were
incorrectly immune to DoS disconnection as well. This old
behaviour is removed for that reason, but can be restored using
-whitelist=127.0.0.1 or -whitelist=::1 can be specified. -whitebind
is safer to use in case non-trusted localhost connections are expected
(like hidden services).
- add a small wrapper in util around RAND_bytes() and replace with
GetRandBytes() in the code to log errors from calling RAND_bytes()
- remove OpenSSL header rand.h where no longer needed
- SO_NOSIGPIPE isn't available on WIN32 so merge the 2 non-WIN32 blocks
- use predefined names from header for IPV6_PROTECTION_LEVEL and
PROTECTION_LEVEL_UNRESTRICTED
bitcoin-config.h moved, but the old file is likely to still exist when
reconfiguring or switching branches. This would've caused files to not rebuild
correctly, and other strange problems.
Make the path explicit so that the old one cannot be found.
Core libs use config/bitcoin-config.h.
Libs (like crypto) which don't want access to bitcoin's headers continue
to use -Iconfig and #include bitcoin-config.h.
- remove an unneded else in ConnectNode()
- make 0 a double and change to 0.0 in ConnectNode()
- rename strDest to pszDest in OpenNetworkConnection()
- remove an unneded call to our REF() macro in BindListenPort()
- small style cleanups and removal of unneeded new-lines
... instead of after 30 minutes of no sending, for latency measurement
and keep-alive. Also, disconnect if no reply arrives within 20 minutes,
instead of 90 of inactivity (for peers supporting the 'pong' message).
NodeSyncScore() should find the node which we recv data most recently, so put a negative sign to pnode->nLastRecv is indeed wrong.
Also change the return value type to int64_t.
Signed-off-by: Huang Le <4tarhl@gmail.com>
Log the name of the error as well as the error code if a network problem
happens. This makes network troubleshooting more convenient.
Use thread-safe strerror_r and the WIN32 equivalent FormatMessage.
Adds two new info query commands that take over information from
hodge-podge `getinfo`.
Also some new information is added:
- `getblockchaininfo`
- `chain`: (string) current chain (main, testnet3, regtest)
- `verificationprogress: (numeric) estimated verification progress
- `chainwork`
- `getnetworkinfo`
- `localaddresses`: (array) local addresses, from mapLocalHost (fixes#1734)
The year is 2014. All supported operating systems have IPv6 support,
most certainly at build time (this doesn't mean that IPv6 is configured,
of course).
If noone is exercising the functionality to disable it, that means it
doesn't get tested, and IMO it's better to get rid of it.
(it's also not used consistently in RPC/boost and Net code...)
When we are over our outbound limit ThreadSocketHandler would try to
keep the connection if the peer was addnoded.
This didn't actually work for two reasons: It didn't actually run
the accept code due to mistaken code flow, and because we have a
limited number of outbound semaphores it couldn't actually use the
connection.
Instead it leaked the socket, which might have caused issue #4034.
This patch just takes out the non-functioning white-listing for now.
Gregory Maxwell