From patchwork Wed Nov 20 18:11:31 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= X-Patchwork-Id: 1198447 X-Patchwork-Delegate: dedeckeh@gmail.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.openwrt.org (client-ip=2607:7c80:54:e::133; helo=bombadil.infradead.org; envelope-from=openwrt-devel-bounces+incoming=patchwork.ozlabs.org@lists.openwrt.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=kleine-koenig.org Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="AGxCJaf7"; dkim-atps=neutral Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 47J9kh1nScz9sPn for ; Thu, 21 Nov 2019 05:11:56 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Subject:MIME-Version:Message-Id:Date:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=81FnWpGnBCEFR69rmSf75HUzvS/QBZXSE4rISfOiuY0=; b=AGxCJaf7aUm8pA Ul5QdKGYDt38l7RSEh+t1/X677OkhyQBU76h33dYM7pc5hDzZ9BqqXrz6H1pCJSalkITHm+XDVvQq We5Wvnf6xcFrIRCgXHk57EUByxCg8PFIijT5tBhSULunj3TsQa03gJtuxRgf29fWnScrxbCsCqlY8 5S/XrBwGZ32h+eGLr08xYnumpM4fK3PIWbYXRC9j0wWL5X3CqEnFIZqqpfYzQ3CDSx3n5EGgfAGGb wC3TGlpWTvZGmQ7E9lnKdzdV4ny2nNNaJv+tNTWMOzaTw0b5vKEGNZhHut+90A+3lX6ukqJYc+IKw PtCDvG8l1F99vm8LdqMw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iXUSB-0003KM-97; Wed, 20 Nov 2019 18:11:47 +0000 Received: from antares.kleine-koenig.org ([94.130.110.236]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iXUS5-0003FO-GL for openwrt-devel@lists.openwrt.org; Wed, 20 Nov 2019 18:11:44 +0000 Received: by antares.kleine-koenig.org (Postfix, from userid 1000) id BD7EB843602; Wed, 20 Nov 2019 19:11:36 +0100 (CET) From: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= To: Felix Fietkau Date: Wed, 20 Nov 2019 19:11:31 +0100 Message-Id: <20191120181131.2622-1-uwe@kleine-koenig.org> X-Mailer: git-send-email 2.24.0 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191120_101141_699675_29737303 X-CRM114-Status: UNSURE ( 8.16 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -0.0 (/) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [94.130.110.236 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -0.0 SPF_HELO_PASS SPF: HELO matches SPF record Subject: [OpenWrt-Devel] [PATCH netifd] interface: warn if ip6hint is truncated X-BeenThere: openwrt-devel@lists.openwrt.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: openwrt-devel@lists.openwrt.org Sender: "openwrt-devel" Errors-To: openwrt-devel-bounces+incoming=patchwork.ozlabs.org@lists.openwrt.org When for example a /60 is assigned to a network the last 4 bits of the ip6hint are unused. Emit a warning if any of these unused bits is set as it indicates that someone didn't understand how the hint is used. (As I did earlier today resulting in spending some time understanding the code.) --- interface.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/interface.c b/interface.c index 028dc6ccd5e5..839de0bb88ad 100644 --- a/interface.c +++ b/interface.c @@ -863,9 +863,15 @@ interface_alloc(const char *name, struct blob_attr *config, bool dynamic) } iface->assignment_hint = -1; - if ((cur = tb[IFACE_ATTR_IP6HINT])) - iface->assignment_hint = strtol(blobmsg_get_string(cur), NULL, 16) & - ~((1 << (64 - iface->assignment_length)) - 1); + if ((cur = tb[IFACE_ATTR_IP6HINT])) { + int32_t assignment_hint = strtol(blobmsg_get_string(cur), NULL, 16); + + iface->assignment_hint = assignment_hint & ~((1 << (64 - iface->assignment_length)) - 1); + + if (iface->assignment_hint != assignment_hint) + netifd_log_message(L_WARNING, "Ignoring set bits of assignment hint for interface '%s'\n", + iface->name); + } if ((cur = tb[IFACE_ATTR_IP6CLASS])) interface_add_assignment_classes(iface, cur);