From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01418C433EF for ; Thu, 9 Sep 2021 13:43:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DF4BB60555 for ; Thu, 9 Sep 2021 13:43:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344322AbhIINoH (ORCPT ); Thu, 9 Sep 2021 09:44:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:42302 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351834AbhIIMrd (ORCPT ); Thu, 9 Sep 2021 08:47:33 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 817D363220; Thu, 9 Sep 2021 11:56:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631188589; bh=Jqb7XaWOx11p37FMvH/ReA+WJNCzFGBf3lqGQwH79gI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=movnjE+IYV+9GnWIiFM5ZIMa66cHmb9QnNzBrSNvar5/oYJUFS+tdsjoalWd8/810 LnIY4LlEGe1fjJHUc18mSUH6iCNUBhw7V2oMGMBHxFj+NQFBALxt9SwvNjGG5faY6C 3wBfSDt3t+fu05F3tnG4czWNRRIQsuYKrbIP8GXTyv0VfgAdpVkT6XOAWeGDSZziXA Eku1KLX0ubgpOd1m2723DiFkCAlS8TdZ6667Vr8M/YVTfJ+ARlPsFvnFBe+d93Fbvd QEPKCSGFEr0RSnKH2yLRUdhM96aAIU2S/v4aCXiteAz9FIkqPWiZacnHYX7x0bSl+X W9/i+WPKjWUrw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Johan Almbladh , Johannes Berg , Sasha Levin , linux-wireless@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 064/109] mac80211: Fix monitor MTU limit so that A-MSDUs get through Date: Thu, 9 Sep 2021 07:54:21 -0400 Message-Id: <20210909115507.147917-64-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210909115507.147917-1-sashal@kernel.org> References: <20210909115507.147917-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Johan Almbladh [ Upstream commit 79f5962baea74ce1cd4e5949598944bff854b166 ] The maximum MTU was set to 2304, which is the maximum MSDU size. While this is valid for normal WLAN interfaces, it is too low for monitor interfaces. A monitor interface may receive and inject MPDU frames, and the maximum MPDU frame size is larger than 2304. The MPDU may also contain an A-MSDU frame, in which case the size may be much larger than the MTU limit. Since the maximum size of an A-MSDU depends on the PHY mode of the transmitting STA, it is not possible to set an exact MTU limit for a monitor interface. Now the maximum MTU for a monitor interface is unrestricted. Signed-off-by: Johan Almbladh Link: https://lore.kernel.org/r/20210628123246.2070558-1-johan.almbladh@anyfinetworks.com Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- net/mac80211/iface.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 6f576306a4d7..ddc001ad9055 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -1875,9 +1875,16 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name, netdev_set_default_ethtool_ops(ndev, &ieee80211_ethtool_ops); - /* MTU range: 256 - 2304 */ + /* MTU range is normally 256 - 2304, where the upper limit is + * the maximum MSDU size. Monitor interfaces send and receive + * MPDU and A-MSDU frames which may be much larger so we do + * not impose an upper limit in that case. + */ ndev->min_mtu = 256; - ndev->max_mtu = local->hw.max_mtu; + if (type == NL80211_IFTYPE_MONITOR) + ndev->max_mtu = 0; + else + ndev->max_mtu = local->hw.max_mtu; ret = register_netdevice(ndev); if (ret) { -- 2.30.2