From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: passt.top; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=YLBn+BiG; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by passt.top (Postfix) with ESMTPS id 0748F5A0262 for ; Mon, 09 Mar 2026 23:11:29 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1773094288; 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=zu1tF+2jc3acKCaSSD/upgkkoSxKCD2QLVTYGQzftCE=; b=YLBn+BiGSvhKgyW7Ir8c/msM75qEsegFLsrjt9BgveOU9c97Ym6ECTKInCaw88hWO4ntsG Y8fby4zaMlC57MXOQ1Gko6Nxi2ZglOgMIv80w68iMp4fLBDCHvPcEqz6T5DqzN/MmDQviS nz8wx0TGa7VSegprjPvdXuULlJ4UzZc= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-80-61QJfIf-O4iAGRGNVmMy1A-1; Mon, 09 Mar 2026 18:11:27 -0400 X-MC-Unique: 61QJfIf-O4iAGRGNVmMy1A-1 X-Mimecast-MFC-AGG-ID: 61QJfIf-O4iAGRGNVmMy1A_1773094286 Received: by mail-wm1-f72.google.com with SMTP id 5b1f17b1804b1-48378df3469so84095905e9.1 for ; Mon, 09 Mar 2026 15:11:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1773094286; x=1773699086; h=date:content-transfer-encoding:mime-version:organization:references :in-reply-to:message-id:subject:cc:to:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=zu1tF+2jc3acKCaSSD/upgkkoSxKCD2QLVTYGQzftCE=; b=Ngnkdlxn0AzivCcMezRgPGQF0OP/mSaAqh410HypMDeIVP/2peaz7ETz1kk7hC2U1Z k674SS4mQ5NEcl9kZDLsTNeVFRw1k4NBgxkvTEONAMuWtaHACO8gY4McjLQcxatg8vCN Gtleo7iw68NZxltF9O3cMu3cVUVJp19QTP3unmuekeVV4IfCI/lwVogEo1XN8a9ybDXw q7B3+urr6M6Nc8k0AFklz1vgD32z0lXUxW22UQrf6F+Kd4rFu8jkZHaXoM20Y8nItAkv A8BBwOxFvY6LAqPsA8Gln4h9oX2huAi1RZWB8AOBGjz8QYUmQBbrnY3oHcdb1Arzy5ux 6K5g== X-Forwarded-Encrypted: i=1; AJvYcCUXFlq1yE9bFhoV4Z4IKCg2ePmPzpV/aW1sHtzCnl75q720QKmR7eU404X6PWmhyQyMKgLawn6HT/c=@passt.top X-Gm-Message-State: AOJu0YzmBWvAaetMGIqoij9HnxDxxlzeR70RLVZhcTBIgroU4EaAe8bX LTwqr+SMLk33yDJO6f6xL2T0DlmoIOoigH6IVzxYLxz0f/O44v8QPrgaWzRAteM45M7VIfuWHMN p+gzh2oT1+k/QipGBOH8AIv7dEXznQ4Gn5LWehDgnzYfiPdtmQl3V4A== X-Gm-Gg: ATEYQzy2diofz6hRSpnC0rK5QeVG4YG9ssV2Tl3KM+6aJu/abN+G48R1jqy627Q9XC1 wdA7zDdy4Hc99PrCXZUJSZqmib2JSIMtvvjf8gaP+3myC1U4r+UXcHNdZ933Z66xHcgZoDJi5RD EOZKaawmI2V/HCqDROtZLQp3gU0AaZo/YMz4DDmZrYzbZzITmJz2pLJ+OyGVdIW4iK8HEmb9VIh Scqb3oV5MUWqYzREUww6aMkzJVhysE5345mwxrU/RJy+lg6pL+1ya+NnrV+MSXn0aC64YkBDjIE bKDB+CLavJDFtCMDPgSc/+ji2OjWPsZsNaEiwbiPL8lwAckBgtKqGk0Xsoz1aHqzlZzTlYHEDbf Tx8UdVA3r67bkxaneCvNVLKX76oJn0Ekp X-Received: by 2002:a05:600c:4509:b0:485:3b4a:f707 with SMTP id 5b1f17b1804b1-485419de2fdmr21387725e9.10.1773094286115; Mon, 09 Mar 2026 15:11:26 -0700 (PDT) X-Received: by 2002:a05:600c:4509:b0:485:3b4a:f707 with SMTP id 5b1f17b1804b1-485419de2fdmr21387325e9.10.1773094285603; Mon, 09 Mar 2026 15:11:25 -0700 (PDT) Received: from maya.myfinge.rs (ifcgrfdd.trafficplex.cloud. [2a10:fc81:a806:d6a9::1]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-48541ac17f2sm20049995e9.6.2026.03.09.15.11.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Mar 2026 15:11:25 -0700 (PDT) From: Stefano Brivio To: Jon Maloy Subject: Re: [PATCH v3] netlink: Return prefix length for IPv6 addresses in nl_addr_get() Message-ID: <20260309231123.0ef586b2@elisabeth> In-Reply-To: <20260309105606.20a31e16@elisabeth> References: <20260307184157.1675234-1-jmaloy@redhat.com> <20260309105606.20a31e16@elisabeth> Organization: Red Hat X-Mailer: Claws Mail 4.2.0 (GTK 3.24.49; x86_64-pc-linux-gnu) MIME-Version: 1.0 Date: Mon, 09 Mar 2026 23:11:24 +0100 (CET) X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: f59uL6zlk9u-wJJylLsAMW0flURWP21VqovROaohmMc_1773094286 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Message-ID-Hash: MZ7UVTAFGJG6T5UJKHHSXFKAVZDIE7BP X-Message-ID-Hash: MZ7UVTAFGJG6T5UJKHHSXFKAVZDIE7BP 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: dgibson@redhat.com, david@gibson.dropbear.id.au, passt-dev@passt.top, Paul Holzinger 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, 9 Mar 2026 10:56:06 +0100 Stefano Brivio wrote: > [...] > > The reason why the original code skipped IPv6 link-local addresses and > not IPv4 link-local ones is that copying a IPv6 link-local address > clearly makes no sense and breaks things. > > For IPv4 I wasn't quite sure, and it seemed to work just like other > addresses, so I never took care of excluding them. > > I tend to think it's correct to exclude them, also for consistency with > IPv6, but I'm not quite sure if we risk breaking something. I have some > vague recollection of link-local addresses being used in some cloud > (probably Google Computing Platform), at least for some Podman tests. > I'll try to find some pointers to it. Paul found this, from a GCE environment used in Podman's CI: https://api.cirrus-ci.com/v1/task/5902961064280064/logs/journal.log (look for "Route IPv4 info"): Mar 09 16:58:37 cirrus-task-5902961064280064 cloud-init[573]: ci-info: +++++++++++++++++++++++++++++++Route IPv4 info++++++++++++++++++++++++++++++++ Mar 09 16:58:37 cirrus-task-5902961064280064 cloud-init[573]: ci-info: +-------+-----------------+------------+-----------------+-----------+-------+ Mar 09 16:58:37 cirrus-task-5902961064280064 cloud-init[573]: ci-info: | Route | Destination | Gateway | Genmask | Interface | Flags | Mar 09 16:58:37 cirrus-task-5902961064280064 cloud-init[573]: ci-info: +-------+-----------------+------------+-----------------+-----------+-------+ Mar 09 16:58:37 cirrus-task-5902961064280064 cloud-init[573]: ci-info: | 0 | 0.0.0.0 | 10.128.0.1 | 0.0.0.0 | ens4 | UG | Mar 09 16:58:37 cirrus-task-5902961064280064 cloud-init[573]: ci-info: | 1 | 10.128.0.1 | 0.0.0.0 | 255.255.255.255 | ens4 | UH | Mar 09 16:58:37 cirrus-task-5902961064280064 cloud-init[573]: ci-info: | 2 | 169.254.169.254 | 10.128.0.1 | 255.255.255.255 | ens4 | UGH | Mar 09 16:58:37 cirrus-task-5902961064280064 cloud-init[573]: ci-info: +-------+-----------------+------------+-----------------+-----------+-------+ ...so there's a route to a link-local address, because that happens to be the DNS server. The host doesn't have a link-local IPv4 address though, so nothing we would risk missing with this kind of change. In any case, as agreed, better to leave that out as you did in v4, because it's not a trivial task to exclude that we're going to break something at this point. -- Stefano