We should learn about new peers via address messages.
An inbound peer connecting to us tells us nothing about
its ability to accept incoming connections from us, so
we shouldn't assume that we can connect to it based on
this.
The vast majority of nodes on the network do not accept
incoming connections, adding them will only slow down
the process of making a successful connection in the
future.
Nodes which have configured themselves to not announce would prefer we
not violate their privacy by announcing them in GETADDR responses.
- Ignore GETBLOCKTXN requests for unknown blocks
Don't disconnect peers, or else we leak information that could be
used for fingerprinting.
- Ignore CMPCTBLOCK messages for pruned blocks
Also ignores CMPCTBLOCK announcements that have too little work. This is to
prevent disk-exhaustion DoS.
Github-Pull: #8408
Rebased-From: 1de2a46632946990a7863020b61172232f8c5796 1d06e49834814eed45e07393dcffd7b6683311b2
We send a newly-accepted peer a 1000-entry addr message, and then only use
vAddrToSend for small messages. Deallocate vAddrToSend after it's been used for
the big message to save about 40 kB per connected inbound peer.
Optimistically test the latch bool before taking the lock.
For all IsInitialBlockDownload calls after the first to return false,
this avoids the need to lock cs_main.
An orphan whos parents were rejected is never going to connect, so there
is little utility in keeping it.
Orphans also helpfully tell us what we're missing, so go ahead and treat
it as INVed.
This prevents higher order orphans and other junk from
holding positions in the orphan map. Parents delayed
twenty minutes are more are unlikely to ever arrive.
The freed space will improve the orphan matching success rate for
other transactions.
This reverts commit caf6150e97.
getaddrinfo_a has a nasty tendency to segfault internally in its
background thread, on every version of glibc I tested, especially
under helgrind.
See https://sourceware.org/bugzilla/show_bug.cgi?id=20874
Github-Pull: #9229
Rebased-From: 10ae7a7b2316f8052ec58ef237ce6dd987300900
