Add NODE_BLOOM service bit
Cherry-picked from the following upstream PRs:
- bitcoin/bitcoin#6579
- Zcash equivalent of BIP 111
- bitcoin/bitcoin#6652
- Docs for BIP 111
- bitcoin/bitcoin#7087
- bitcoin/bitcoin#7174
- bitcoin/bitcoin#8709
Part of #2074. Closes#2738.
An example of where this might be useful is allowing a node to connect blocksonly during IBD but then becoming a full-node once caught up with the latest block. This might also even want to be the default behaviour since during IBD most TXs appear to be orphans, and are routinely dropped (for example when a node disconnects). Therefore, this can waste a lot of bandwidth.
Additionally, another pull could be written to stop relaying of TXs to nodes that are clearly far behind the latest block and are running a node that doesn't store many orphan TXs, such as recent versions of Bitcoin Core.
Previously peers which implement a protocol version less than NO_BLOOM_VERSION
would not be disconnected for sending a filter command, regardless of the
peerbloomfilter option.
Many node operators do not wish to provide expensive bloom filtering for SPV
clients, previously they had to cherry pick the commit which enabled the
disconnect logic.
The default should remain false until a sufficient percent of SPV clients
have updated.
Lets nodes advertise that they offer bloom filter support explicitly.
The protocol version bump allows SPV nodes to assume that NODE_BLOOM is
set if NODE_NETWORK is set for pre-170004 nodes.
Also adds an option to turn bloom filter support off for nodes which
advertise a version number >= 170004. Nodes attempting to use bloom
filters on such protocol versions are banned, and a later upgade
should drop nodes of an older version which attempt to use bloom
filters.
Much code stolen from Peter Todd.
Zcash: Implements Zcash equivalent of BIP 111; deploys with Overwinter
Instead of iterating over 0 .. 1 and then deciding on an actual desired
value, use a range based for loop for the desired value.
Adapted from d0413c670b4e5dc79d5cc1bc35571fca745c9a24
Authored-by: René Nyffenegger <mail@renenyffenegger.ch>
Use of `sprintf` is seen as a red flag as many of its uses are insecure.
OpenBSD warns about it while compiling, and some modern platforms, e.g.
[cloudlibc from cloudabi](https://github.com/NuxiNL/cloudlibc) don't
even provide it anymore.
Although our uses of these functions are secure, it can't hurt to
replace them anyway. There are only 3 occurences left, all in the
tests.
I made a silly mistake in a database wrapper where keys
were sorted by char instead of uint8_t. As x86 char is signed
the sorting for the block index database was messed up, resulting
in a segfault due to missing records.
Add a test to catch:
- Wrong sorting
- Seeking errors
- Iteration result not complete
Zcash: Makes future extensions easier.
Original description (when this was introduced upstream):
Pass parent wrapper directly instead of obfuscation key. This
makes it possible for other databases which re-use this code
to use other properties from the database.
Add a namespace dbwrapper_private for private functions to be used
only in dbwrapper.h/cpp and dbwrapper_tests.
When rewinding, remove insufficiently-validated blocks
If a block is insufficiently-validated against a particular branch ID, then we
cannot guarantee that even the block header will be valid under the actual
consensus rules the node will want to apply. Instead require that the blocks are
completely re-validated, by removing them from the block index (which is
equivalent to reducing their validity to BLOCK_VALID_UNKNOWN).
Closes#3100.
