From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by passt.top (Postfix) with ESMTP id 7A78A5A027F for ; Mon, 22 May 2023 17:30:06 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1684769405; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iMZ25R1ODpSaBqE1/gzheNoncB5zef0iUhMa78TLcU4=; b=UbzIxYZvjjtS87JTHscyZ/fXJgf1A59Pau7MljrOhUI7h6rK15wcqA6M9F3/XN4+/i0kTO QvjHR/TFkoBPkG0bFjDR5yNF2/tEu5Z4gBn1IZ6MQgji1xBaZrfeV9REygOjJsHA0M7JNZ SIQgDDNEZUqQCvjIT8jZoVFai9E5yH4= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-313-oWsVff6MPkqV_gOPAJ-N5Q-1; Mon, 22 May 2023 11:30:04 -0400 X-MC-Unique: oWsVff6MPkqV_gOPAJ-N5Q-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 46CAD3801BE9; Mon, 22 May 2023 15:30:03 +0000 (UTC) Received: from elisabeth (unknown [10.39.208.35]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D2503C1ED99; Mon, 22 May 2023 15:30:01 +0000 (UTC) Date: Mon, 22 May 2023 17:29:59 +0200 From: Stefano Brivio To: David Gibson Subject: Re: [PATCH v2 07/10] conf: Don't exit if sourced default route has no gateway Message-ID: <20230522172959.4703f517@elisabeth> In-Reply-To: References: <20230521234224.2770015-1-sbrivio@redhat.com> <20230521234224.2770015-8-sbrivio@redhat.com> Organization: Red Hat MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Message-ID-Hash: QPTWQLKU3KRVUQO63RNXLN6SMNXVAKET X-Message-ID-Hash: QPTWQLKU3KRVUQO63RNXLN6SMNXVAKET X-MailFrom: sbrivio@redhat.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: passt-dev@passt.top, Callum Parsey , me@yawnt.com, lemmi@nerd2nerd.org, Andrea Arcangeli X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On Mon, 22 May 2023 18:48:39 +1000 David Gibson wrote: > On Mon, May 22, 2023 at 01:42:21AM +0200, Stefano Brivio wrote: > > If we use a template interface without a gateway on the default > > route, we can still offer almost complete functionality, except that, > > of course, we can't map the gateway address to the outer namespace or > > host, and that we have no obvious server address or identifier for > > use in DHCP's siaddr and option 54 (Server identifier, mandatory). > > > > Continue, if we have a default route but no default gateway, and > > imply --no-map-gw and --no-dhcp in that case. NDP responder and > > DHCPv6 should be able to work as usual because we require a > > link-local address to be present, and we'll fall back to that. > > Implying (rather than requiring) --no-map-gw and --no-dhcp does worry > me a bit. I feel like it might violate the principle of least > surprise. Well, yes, but on the other hand it risks to be a lot of typing (and changes to the Podman integration) for a relatively common setup. And we might even figure out there's a way and a benefit to re-enable DHCP support in this case. I'm not fond of that either, but I still prefer it to the alternative. -- Stefano