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.
We're using GetRandomBytes in several contexts where it's either
unwieldy to return an error, or an error would mean a fatal exception
anyhow.
@gmaxwell checked OpenSSL a while ago and discovered that it never
actually fails, but it can't hurt to be a bit paranoid here.
This is less surprising.
Avoids the overload-the-CPU default of using N threads for script
verification as well as N threads for generation where N is number of cores.
Start the RPC server before doing all the (expensive) startup
initialisations like loading the block index. Until the node is ready,
return all calls immediately with a new error signalling "in warmup"
with an appropriate status message (similar to the init message).
This is useful for RPC clients to know that the server is there (e. g.,
they don't have to start it) but not yet available. It is used in
Namecoin and Huntercoin already for some time, and there exists a UI
hooked onto the RPC interface that actively uses this to its advantage.
- guard 4 connect calls by an #ifdef when no wallet is loaded to fix "No
such slot" warnings
- also add comments when #ifdef ENABLE_WALLET end
- fixes#5175
Move transaction new/update notification to TransactionTableModel.
This moves the concerns to where they're actually handled.
No need to bounce this through wallet model.
- Do wallet transaction preprocessing on signal handler side;
avoids locking cs_main/cs_wallet on notification in GUI thread
(except for new transactions)