From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FROM,HTML_MESSAGE,MAILING_LIST_MULTI, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 13744 invoked from network); 28 Jun 2022 12:38:11 -0000 Received: from minnie.tuhs.org (50.116.15.146) by inbox.vuxu.org with ESMTPUTF8; 28 Jun 2022 12:38:11 -0000 Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id F30FD40C93; Tue, 28 Jun 2022 22:37:47 +1000 (AEST) Received: from mail-vk1-f170.google.com (mail-vk1-f170.google.com [209.85.221.170]) by minnie.tuhs.org (Postfix) with ESMTPS id 0739440C92 for ; Tue, 28 Jun 2022 22:37:44 +1000 (AEST) Received: by mail-vk1-f170.google.com with SMTP id b5so5883021vkp.4 for ; Tue, 28 Jun 2022 05:37:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Iasvcu0x51F0UsieKmvMpmHRTktjZX3sKO/Tz/9Wcf8=; b=oUVEf5dlYKdcZDYVzqgMjITKFMQhsjSK+1bWQ5Fbc4b9hVUI+ABji2X6hjrFEnKDxX AWVCoWWRI3/FG0Lg3GOP3C1n8bqPM4A+h8cNb4cX6feloSv84aanWlw7B1El17Vogh2P 3JTZWH0rPtBJx7xkfbnDHPl2wL/kx61jmkasQdokgm9ZqD9IsUua8RLd3FBrkGgbw1PQ S77ZHdnbQbQt5NBKAsGuH9IbcVir17TPyznLBPp89ShpjYTDfWRLD6mLKWQpQRM5GUOS SM3s802ybnKvViaztP/HKF440P5OLtx7vz416T1HN8UrbH1tkRogQ4fJH4srrhlp9Vpc CJlA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Iasvcu0x51F0UsieKmvMpmHRTktjZX3sKO/Tz/9Wcf8=; b=5cwXNZopkVtRKA9gtdfQubKP9OL87MCQit3iGqn+2ic215O8HNeAnSnbfx3gCBwNQo v2ZXWJobUR/j9JSx9XMiUu1oVlJkkaZOokZwMk0DBeF6hKMcy4X91PS+tewwkYCbaI5y +0Wm3L/0p2UM3Ag5hCje11sJsbm2C81u2vCZpmy0TQuO8UNn/yvJ1UV4yS9O6SI+ZjRi XS75E+zm7LvGGerxLCzzxCN9DIjvget5PEqQiBnWqFqaZCPUTxvrASoeYPxbnQ0scIuP 4zclb5Qin5UgvYO+XTEGdAt5nI4j+fwM9nHW0fwpX+iDFDwwIgw1fdM3oj6G92606xZ3 FtnA== X-Gm-Message-State: AJIora8YB8TbC6fod7LI/Ge/jDdgKAOlNtIdaBfLHVokrbGTdGqxkJ/O xHcZFUVc6KbNb/deiNHBvnl+rqEzC0N/Ikip5qGZ50nA X-Google-Smtp-Source: AGRyM1u6NiJtRfJu46siHGVz+lpvt5YUB/np6f0FBqzXpcccnPQQHHEKKnI8vadfndWwls/Nezif6pTXqBgq40osZsI= X-Received: by 2002:a1f:aac7:0:b0:35e:1c45:def with SMTP id t190-20020a1faac7000000b0035e1c450defmr1256576vke.35.1656419802838; Tue, 28 Jun 2022 05:36:42 -0700 (PDT) MIME-Version: 1.0 References: <2803DC51-6CBC-4257-B40C-8A559C27CAE3@planet.nl> <20220625230939.GG19404@mcvoy.com> In-Reply-To: From: Rob Pike Date: Tue, 28 Jun 2022 22:36:31 +1000 Message-ID: To: Derek Fawcus Content-Type: multipart/alternative; boundary="000000000000f27abe05e281498b" Message-ID-Hash: NO65WJX462UNS2UFRVFCJFCMXPE3MPP7 X-Message-ID-Hash: NO65WJX462UNS2UFRVFCJFCMXPE3MPP7 X-MailFrom: robpike@gmail.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-tuhs.tuhs.org-0; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: The Eunuchs Hysterical Society X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: Research Datakit notes List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: --000000000000f27abe05e281498b Content-Type: text/plain; charset="UTF-8" I am not a networking expert. I said that already. The issue could well be a property more of sockets than TCP/IP itself, but having the switch do some of the call validation and even maybe authentication (I'm not sure...) sounds like it takes load off the host. -rob On Tue, Jun 28, 2022 at 8:39 PM Derek Fawcus < dfawcus+lists-tuhs@employees.org> wrote: > On Sun, Jun 26, 2022 at 09:57:17AM +1000, Rob Pike wrote: > > One of the things we liked about Datakit was that the computer didn't > have > > to establish the connection before it could reject the call, unlike > TCP/IP > > where all validation happens after the connection is made. > > Nor does TCP, one can send a RST to a SYN, and reject the call before it is > established. That would then look to the caller just like a non listening > endpoint, unless one added data with the RST. > > So this is really just a consequence of the sockets API, and the current > implementations. > I've a vague recall of folks suggesting ways to expose that facility via > the sockets > layer, possibly using setsockopt(), but don't know if anyone ever did it. > > As I recall that TCP capability was actually exposed via the TLI/XTI API, > and (for some STREAMS based TCP stacks) it did function. Although I may be > thinking of embedded STREAMS TCP stacks, not unix based stacks. > > Or by 'connection' are you referring to an end-to-end packet delivery, > and that Datakit allowed a closer switch to reject a call before the packet > got to the far end? > > DF > --000000000000f27abe05e281498b Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
I am not a networking expert. I said that already. The iss= ue could well be a property more of sockets than TCP/IP itself, but having = the switch do some of the call validation and even maybe authentication (I&= #39;m not sure...) sounds like it takes load off the host.

-rob


On Tue, Jun 28, 2022 at 8:39 PM Derek Fawcus = <dfawcus+lists-tuh= s@employees.org> wrote:
On Sun, Jun 26, 2022 at 09:57:17AM +1000, Rob Pike wrote: > One of the things we liked about Datakit was that the computer didn= 9;t have
> to establish the connection before it could reject the call, unlike TC= P/IP
> where all validation happens after the connection is made.

Nor does TCP, one can send a RST to a SYN, and reject the call before it is=
established.=C2=A0 That would then look to the caller just like a non liste= ning
endpoint, unless one added data with the RST.

So this is really just a consequence of the sockets API, and the current im= plementations.
I've a vague recall of folks suggesting ways to expose that facility vi= a the sockets
layer, possibly using setsockopt(), but don't know if anyone ever did i= t.

As I recall that TCP capability was actually exposed via the TLI/XTI API, and (for some STREAMS based TCP stacks) it did function. Although I may be<= br> thinking of embedded STREAMS TCP stacks, not unix based stacks.

Or by 'connection' are you referring to an end-to-end packet delive= ry,
and that Datakit allowed a closer switch to reject a call before the packet=
got to the far end?

DF
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