…n be shared and reused

(cherry picked from commit 5e10922)

To make it clear where DNS resolves are happening

(cherry picked from commit e9fc71e)

Note: Some seeds aren't actually returning an IP for their name entries, so
they're being added to addrman with a source of [::].

This commit shouldn't change that behavior, for better or worse.

(cherry picked from commit a98cd1f)

Rather than allowing CNetAddr/CService/CSubNet to launch DNS queries, require
that addresses are already resolved.

This greatly simplifies async resolve logic, and makes it harder to
accidentally leak DNS queries.

(cherry picked from commit 3675699)

CNetAddr/CService/CSubnet can no longer resolve DNS.

(cherry picked from commit d39f5b4)

(cherry picked from commit ee06e04)

…round use of nServices

(cherry picked from commit 31d6b1d)

(cherry picked from commit f96c7c4)

(cherry picked from commit b6c3ff3)

(cherry picked from commit 1017b8a)

(cherry picked from commit 21e5b96)

Net functionality is no longer needed for CAddress/CAddrman/etc. now that
CNetAddr/CService/CSubNet are dumb storage classes.

(cherry picked from commit 21ba407)

Also fix up a few small issues:
- Lookup with "badip:port" now sets the port to 0
- Don't allow assert to have side-effects

(cherry picked from commit 8945384)

(cherry picked from commit 9e9d644)

(cherry picked from commit ccef5d7)

-BEGIN VERIFY SCRIPT-

sed --in-place'' --expression='s/NET_TOR/NET_ONION/g' $(git grep -I --files-with-matches 'NET_TOR')

-END VERIFY SCRIPT-

The --in-place'' hack is required for sed on macOS to edit files in-place without passing a backup extension.

(cherry picked from commit 07c493f)

( cherry-plucked from: b691f2d )

In github context:

bitcoin/bitcoin@b691f2d#diff-9281caf81406a5c4e11f572f613a4cc9769f39c66579ed75a4c957f30b39d836

Do not access `CNetAddr::ip` directly from `CService` methods.

This improvement will help later when we change the type of
`CNetAddr::ip` (in the BIP155 implementation).

Co-authored-by: Carl Dong <contact@carldong.me>
(cherry picked from commit bc74a40)

(cherry picked from commit 100c64a)

We currently do two resolves for dns seeds: one for the results, and one to
serve in addrman as the source for those addresses.

There's no requirement that the source hostname resolves to the stored
identifier, only that the mapping is unique. So rather than incurring the
second lookup, combine a private subnet with a hash of the hostname.

The resulting v6 ip is guaranteed not to be publicy routable, and has only a
negligible chance of colliding with a user's internal network (which would be
of no consequence anyway).

(cherry picked from commit 7f31762)

(cherry picked from commit 100c64a)

(cherry picked from commit 2ac8bf9)

…_PRIORITY!

FastRandomContext now provides all functionality that the real Rand* functions
provide.

(cherry picked from commit 37e864e)

Note this doesn't build, missing identifier: SHA256D64
(cherry picked from commit e549bf8)

This is needed when we want to encode an arbitrary number as CompactSize
like node service flags, which is a bitmask and could be bigger than the
usual size of an object.

(cherry picked from commit 1d3ec2a)
(cherry picked from commit e86ce4e)

(cherry picked from commit 92beff1)

Change the serialization of `CAddrMan` to serialize its addresses
in ADDRv2/BIP155 format by default. Introduce a new `CAddrMan` format
version (3).

Add support for ADDRv2 format in `CAddress` (un)serialization.

Co-authored-by: Carl Dong <contact@carldong.me>
(cherry picked from commit 201a459)
(cherry picked from commit bd2c485)

(cherry picked from commit 857baca)

(cherry picked from commit 27d53eb)

(cherry picked from commit 5c34bff)

CVectorWriter is useful for overwriting or appending an existing byte vector.

CNetMsgMaker is a shortcut for creating messages on-the-fly which are suitable
for pushing to CConnman.

(cherry picked from commit 2ec935d)
(cherry picked from commit 878e63c)

minimally change net_processing by adding "addrv2" as a strCommand
minimally change net.h with addition of m_wants_addrv2

(cherry picked from commit 353a3fd)
(cherry picked from commit d2d5557)

 (cherry picked from commit 353a3fd)

(cherry picked from commit 19ee7cf)

  (cherry picked from commit dcf0cb4)

(cherry picked from commit 796c30a)