Simplified version of #8278. Assumes that every OS that (a) is supported
by Bitcoin Core (b) supports daemonization has the `daemon()` function
in its C library.
- Removes the fallback path for operating systems that support
daemonization but not `daemon()`. This prevents never-exercised code from
ending up in the repository (see discussion here:
https://github.com/bitcoin/bitcoin/pull/8278#issuecomment-242704745).
- Removes the windows-specific path. Windows doesn't support `daemon()`,
so it don't support daemonization there, automatically.
Original code by Matthew King, adapted by Wladimir van der Laan.
After #8594 the addrFrom sent by a node is not used anymore at all,
so don't bother sending it.
Also mitigates the privacy issue in (#8616). It doesn't completely solve
the issue as GetLocalAddress is also called in AdvertiseLocal, but at
least when advertising addresses it stands out less as *our* address.
This was broken by 63cafa6329.
Note that while this fixes the settings, it doesn't fix the actual usage of
-maxuploadtarget completely, as there is currently a bug in the
nOptimisticBytesWritten accounting that causes a delayed response if the target
is reached. That bug will be addressed separately.
In the case of (for example) an already-running bitcoind, the shutdown sequence
begins before CConnman has been created, leading to a null-pointer dereference
when g_connman->Stop() is called.
Instead, Just let the CConnman dtor take care of stopping.
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.
Johnson Lau