9ad6746ccd Use static_cast instead of C-style casts for non-fundamental types (practicalswift)
Pull request description:
A C-style cast is equivalent to try casting in the following order:
1. `const_cast(...)`
2. `static_cast(...)`
3. `const_cast(static_cast(...))`
4. `reinterpret_cast(...)`
5. `const_cast(reinterpret_cast(...))`
By using `static_cast<T>(...)` explicitly we avoid the possibility of an unintentional and dangerous `reinterpret_cast`. Furthermore `static_cast<T>(...)` allows for easier grepping of casts.
For a more thorough discussion, see ["ES.49: If you must use a cast, use a named cast"](https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#es49-if-you-must-use-a-cast-use-a-named-cast) in the C++ Core Guidelines (Stroustrup & Sutter).
Tree-SHA512: bd6349b7ea157da93a47b8cf238932af5dff84731374ccfd69b9f732fabdad1f9b1cdfca67497040f14eaa85346391404f4c0495e22c467f26ca883cd2de4d3c
2b839ab Update chainparams comment for more info on service bits per dnsseed (Matt Corallo)
62e7642 Fall back to oneshot for DNS Seeds which don't support filtering. (Matt Corallo)
51ae766 Use GetDesireableServiceFlags in static seeds, document this. (Matt Corallo)
fb6f6b1 bluematt's testnet-seed now supports x9 (and is just a static list) (Matt Corallo)
Pull request description:
4440710 broke inserting entries into addrman from dnsseeds which
did not support service bits, as well as static seeds. Static seeds
were already being filtered by UA for 0.13.1+ (ie NODE_WITNESS), so
simply changing the default service bits to include NODE_WITNESS
(and updating docs appropriately) is sufficient. For DNS Seeds, not
supporting NODE_WITNESS is no longer useful, so instead use
non-filtering seeds as oneshot hosts irrespective of named proxy.
I've set my testnet-seed to also support x9, though because it is simply a static host, it may be useful to leave the support off so that it is used as a oneshot to get addresses from a live node instead. I'm fine with either.
Tree-SHA512: 3f17d4d2b0b84d876981c962d2b44cb0c8f95f52c56a48c6b35fd882f6d7a40805f320ec452985a1c0b34aebddb1922709156c3ceccd1b9f8363fd7cb537d21d
44407100f broke inserting entries into addrman from static seeds
(as well as dnsseeds which did not support service bits). Static
seeds were already being filtered by UA for 0.13.1+ (ie
NODE_WITNESS), so simply changing the default service bits to
include NODE_WITNESS (and updating docs appropriately) is
sufficient.
For DNS Seeds, we will later fix by falling back to oneshot if a
seed does not support filtering.
Adds HasAllRelevantServices and GetRelevantServices, which check
for NETWORK|WITNESS.
This changes the following:
* Removes nRelevantServices from CConnman, disconnecting it a bit
more from protocol-level logic.
* Replaces our sometimes-connect-to-!WITNESS-nodes logic with
simply always requiring WITNESS|NETWORK for outbound non-feeler
connections (feelers still only require NETWORK).
* This has the added benefit of removing nServicesExpected from
CNode - instead letting net_processing's VERSION message
handling simply check HasAllRelevantServices.
* This implies we believe WITNESS nodes to continue to be a
significant majority of nodes on the network, but also because
we cannot sync properly from !WITNESS nodes, it is strange to
continue using our valuable outbound slots on them.
* In order to prevent this change from preventing connection to
-connect= nodes which have !WITNESS, -connect nodes are now
given the "addnode" flag. This also allows outbound connections
to !NODE_NETWORK nodes for -connect nodes (which was already true
of addnodes).
* Has the (somewhat unintended) consequence of changing one of the
eviction metrics from the same
sometimes-connect-to-!WITNESS-nodes metric to requiring
HasRelevantServices.
This should make NODE_NETWORK_LIMITED much simpler to implement.
A C-style cast is equivalent to try casting in the following order:
1. const_cast(...)
2. static_cast(...)
3. const_cast(static_cast(...))
4. reinterpret_cast(...)
5. const_cast(reinterpret_cast(...))
By using static_cast<T>(...) explicitly we avoid the possibility
of an unintentional and dangerous reinterpret_cast. Furthermore
static_cast<T>(...) allows for easier grepping of casts.
Remove the nType and nVersion as parameters to all serialization methods
and functions. There is only one place where it's read and has an impact
(in CAddress), and even there it does not impact any of the recursively
invoked serializers.
Instead, the few places that need nType or nVersion are changed to read
it directly from the stream object, through GetType() and GetVersion()
methods which are added to all stream classes.
This concretizes the numbers and adds a comment to make it clear that
these numbers are fixed by the protocol, and may avoid people forgetting
to claim numbers in the future (e.g. issue #8500).
Also gets rid of a weird unused `MSG_TYPE_MAX` in the middle of the
enumeration (thanks @paveljanik for noticing).
In principle, the checksums of P2P packets are simply 4-byte blobs which
are the first four bytes of SHA256(SHA256(payload)).
Currently they are handled as little-endian 32-bit integers half of the
time, as blobs the other half, sometimes copying the one to the other,
resulting in somewhat confused code.
This PR changes the handling to be consistent both at packet creation
and receiving, making it (I think) easier to understand.
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.
- 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.
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-70011 nodes.
Also adds an option to turn bloom filter support off for nodes which
advertise a version number >= 70011. 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.
Implements BIP 111
Thanks to Pieter Wuille for most of the work on this commit.
I did not fixup the overhaul commit, because a rebase conflicted
with "remove fields of ser_streamplaceholder".
I prefer not to risk making a mistake while resolving it.
The implementation of each class' serialization/deserialization is no longer
passed within a macro. The implementation now lies within a template of form:
template <typename T, typename Stream, typename Operation>
inline static size_t SerializationOp(T thisPtr, Stream& s, Operation ser_action, int nType, int nVersion) {
size_t nSerSize = 0;
/* CODE */
return nSerSize;
}
In cases when codepath should depend on whether or not we are just deserializing
(old fGetSize, fWrite, fRead flags) an additional clause can be used:
bool fRead = boost::is_same<Operation, CSerActionUnserialize>();
The IMPLEMENT_SERIALIZE macro will now be a freestanding clause added within
class' body (similiar to Qt's Q_OBJECT) to implement GetSerializeSize,
Serialize and Unserialize. These are now wrappers around
the "SerializationOp" template.
