Merge #18808: [net processing] Drop unknown types in getdata

9847e205bf [docs] Improve commenting in ProcessGetData() (John Newbery)
2f032556e0 [test] test that an invalid GETDATA doesn't prevent processing of future messages (Amiti Uttarwar)
e257cf71c8 [net processing] ignore unknown INV types in GETDATA messages (Amiti Uttarwar)
047ceac142 [net processing] ignore tx GETDATA from blocks-only peers (Amiti Uttarwar)

Pull request description:

  Currently we'll stall peers that send us an unknown INV type in a GETDATA message. Be a bit more friendly and just drop the invalid request.

  Ditto for blocks-relay-only peers that send us a GETDATA for a transaction.

  There's a test for the first part. The second is difficult to test in the functional test framework since we aren't able to make blocks-relay-only connections.

ACKs for top commit:
  sipa:
    utACK 9847e205bf
  brakmic:
    ACK https://github.com/bitcoin/bitcoin/commit/9847e205bf7edcac4c30ce4b6d62f482aa7bc1b7
  luke-jr:
    utACK 9847e205bf
  naumenkogs:
    utACK 9847e20
  ajtowns:
    utACK 9847e205bf

Tree-SHA512: 6007f2fd839ffe737727f6fb8e8f083b2d9e05a510748f1d40b8f9be8fdf7b5419a36d8f1039923eec1ba2983e8f6f0436ec5fc196d9f6dcb0657f2ff8ff8e4c

test/functional/test_runner.py

@@ -157,6 +157,7 @@ BASE_SCRIPTS = [
     'rpc_deprecated.py',
     'wallet_disable.py',
     'p2p_addr_relay.py',
+    'p2p_getdata.py',
     'rpc_net.py',
     'wallet_keypool.py',
     'wallet_keypool.py --descriptors',