Date: Wed, 5 Oct 2022 16:55:39 +1000
From: Anthony Towns <aj@erisian.com.au>
To: eric@voskuil.org,
 Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Message-ID: <Yz0qa9q/DrvbuOb0@erisian.com.au>
References: <005e01d87b89$3d99df60$b8cd9e20$@voskuil.org>
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 <02fc01d8d84d$90a7b120$b1f71360$@voskuil.org>
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In-Reply-To: <02fc01d8d84d$90a7b120$b1f71360$@voskuil.org>
Subject: Re: [bitcoin-dev] Packaged Transaction Relay
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On Tue, Oct 04, 2022 at 05:01:04PM -0700, Eric Voskuil via bitcoin-dev wrote:
> [Regarding bandwidth waste: I've pointed out in years past that
> breaking the Bitcoin versioning scheme creates a requirement that any
> unknown message type be considered valid. Up until a recently-deployed
> protocol change, it had always been possible to validate messages by
> type. I noticed recently that validating nodes have been dropping peers
> at an increasing rate (a consequence of that deployment). Despite being
> an undocumented compatibility break, it is now unfortunately a matter
> of protocol that a peer must allow its peers to waste its bandwidth to
> remain compatible - something which we should eliminate.]

The only message listed as not being preceded by a bumped version number
in:

https://github.com/libbitcoin/libbitcoin-network/wiki/Protocol-Versioning

is addrv2 (though addrv2 is gated on mutual exchange of sendaddrv2, so
it's presumably the sendaddrv2 message at issue), however since [0]
sendaddrv2 messages are only sent to nodes advertising version 70016 or
later (same as wtxidrelay). ADDRV2 was introduced May 20 2020 after the
0.20 branch, and SENDADDRV2 gating was merged Dec 9 2020 and included
from 0.21.0rc3 onwards.

[0] https://github.com/bitcoin/bitcoin/pull/20564

I'm only seeing "bytesrecv_per_msg.*other*" entries for nodes advertising
a version of 0.17 and 0.18, which I presume is due to REJECT messages (for
taproot txs, perhaps?). Otherwise, I don't think there are any unexpected
messages you should be receiving when advertising version 70015 or lower.

Cheers,
aj