From: Eric Voskuil <eric@voskuil•org>
To: Matt Corallo <lf-lists@mattcorallo•com>,
Bitcoin Protocol Discussion
<bitcoin-dev@lists•linuxfoundation.org>,
Pieter Wuille <pieter.wuille@gmail•com>
Cc: libbitcoin@lists•dyne.org
Subject: Re: [bitcoin-dev] BIP151 protocol incompatibility
Date: Mon, 13 Feb 2017 03:17:11 -0800 [thread overview]
Message-ID: <0983c823-e517-2821-1398-24bc7467b364@voskuil.org> (raw)
In-Reply-To: <9ECDD902-1D2C-4500-8FC2-4DADF46E4318@mattcorallo.com>
[-- Attachment #1: Type: text/plain, Size: 2224 bytes --]
On 02/13/2017 03:11 AM, Matt Corallo wrote:
> I believe many, if not all, of those messages are sent irrespective of version number.
In the interest of perfect clarity, see your code:
https://github.com/bitcoin/bitcoin/blob/master/src/net_processing.cpp#L1372-L1403
Inside of the VERACK handler (i.e. after the handshake) there is a peer
version test before sending SENDCMPCT (and SENDHEADERS).
I have no idea where the fee filter message is sent, if it is sent at
all. But I have *never* seen any control messages arrive before the
handshake is complete.
> In any case, I fail to see how adding any additional messages which
are ignored by old peers amounts to a lack of backward compatibility.
See preceding messages in this thread, I think it's pretty clearly
spelled out.
e
> On February 13, 2017 11:54:23 AM GMT+01:00, Eric Voskuil <eric@voskuil•org> wrote:
>> On 02/13/2017 02:16 AM, Matt Corallo wrote:
>>> For the reasons Pieter listed, an explicit part of our version
>> handshake and protocol negotiation is the exchange of otherwise-ignored
>> messages to set up optional features.
>>
>> Only if the peer is at the protocol level that allows the message:
>>
>> compact blocks:
>>
>> https://github.com/bitcoin/bitcoin/blob/master/src/protocol.h#L217-L242
>>
>> fee filter:
>>
>> https://github.com/bitcoin/bitcoin/blob/master/src/protocol.h#L211-L216
>>
>> send headers:
>>
>> https://github.com/bitcoin/bitcoin/blob/master/src/protocol.h#L204-L210
>>
>> filters:
>>
>> https://github.com/bitcoin/bitcoin/blob/master/src/protocol.h#L170-L196
>>
>>> Peers that do not support this ignore such messages, just as if they
>> had indicated they wouldn't support it, see, eg BIP 152's handshake.
>> Not
>> sure why you consider this backwards incompatible, as I would say it's
>> pretty clearly allowing old nodes to communicate just fine.
>>
>> No, it is not the same as BIP152. Control messages apart from BIP151
>> are
>> not sent until *after* the version is negotiated.
>>
>> I assume that BIP151 is different in this manner because it has a
>> desire
>> to negotiate encryption before any other communications, including
>> version.
>>
>> e
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 490 bytes --]
next prev parent reply other threads:[~2017-02-13 11:17 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-13 5:18 Eric Voskuil
2017-02-13 8:47 ` Pieter Wuille
2017-02-13 9:36 ` Eric Voskuil
2017-02-13 10:07 ` Jonas Schnelli
2017-02-13 10:30 ` Eric Voskuil
2017-02-13 11:14 ` Jonas Schnelli
2017-02-14 19:54 ` Eric Voskuil
2017-02-14 20:58 ` Jonas Schnelli
2017-02-13 10:16 ` Matt Corallo
2017-02-13 10:54 ` Eric Voskuil
2017-02-13 11:11 ` Matt Corallo
2017-02-13 11:17 ` Eric Voskuil [this message]
2017-02-13 13:04 ` Matt Corallo
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=0983c823-e517-2821-1398-24bc7467b364@voskuil.org \
--to=eric@voskuil$(echo .)org \
--cc=bitcoin-dev@lists$(echo .)linuxfoundation.org \
--cc=lf-lists@mattcorallo$(echo .)com \
--cc=libbitcoin@lists$(echo .)dyne.org \
--cc=pieter.wuille@gmail$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox