From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1C51913A265; Wed, 4 Jun 2025 00:54:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748998447; cv=none; b=e+xcXO7KCYDOAG5nJ61CrCOgT3fnZlNLiF6OYz09al8dnBkFRgtAiwtuoitqJfvDmgC/hiMF34TRDu/k8/JkFFnsLJEzf2l96HOgPmbvXnZ+dPP5bv2yZ2JnNXc35VQFkgqLYB0+EWj5QAD7oiGApqhn+hEOA9oyyhrczpiNEng= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748998447; c=relaxed/simple; bh=0KjZ6jbg/cTqOlL4jaiirb3ZZ16p0OrxMSCm0JPDxw8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=Qvdn6N+yp8+UZE6M2UMlRDNgQgt34G9wOqEzGw++Enoxp665iC6XiAib8YmrtQiOFTCs2ZLG1QOjFOv4gBm4NS/vZIKLdpEDAc8niXNo0aKNWKJv7KaOnzV6rij0j0BzoH+3rACFNy/94HRmVrdCZfDJRSMWHc2H1WnhMQWQ7E0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IepF5P48; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IepF5P48" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28B9DC4CEEF; Wed, 4 Jun 2025 00:54:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1748998447; bh=0KjZ6jbg/cTqOlL4jaiirb3ZZ16p0OrxMSCm0JPDxw8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IepF5P48jUVROn2Wg/BwxInRKXHRqRzZlZ3qG18WVq8uVh9m9TSDmvT3EI3sKBUG7 w4MPBzpZ3GXBUAsairTkZdHdTfn+8hnsgG2jjFE0AyBdF71MpRsmavVh9fisIQ4NP2 bbS7cNwus7taYHriikYj87IKxWMuchjUK/xRUFZqH7+FUmRSCCRa0rv9xwBNcNx4vC CrhFgn3ZA2HVaZq1lWA1b56eI04dJFdH4WhA3zK+aztOyL4e3V3q9EBZVnbLZ0ydeQ tuslvTWcnoEP2PwBxU13SzMWYWPOwOL3DsmUJp4YCkK2v4wmuidZDknTvLiPz0lKI8 R3WnNKYfR/SnQ== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Muna Sinada , Johannes Berg , Sasha Levin , johannes@sipsolutions.net, linux-wireless@vger.kernel.org Subject: [PATCH AUTOSEL 6.15 082/118] wifi: mac80211: VLAN traffic in multicast path Date: Tue, 3 Jun 2025 20:50:13 -0400 Message-Id: <20250604005049.4147522-82-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250604005049.4147522-1-sashal@kernel.org> References: <20250604005049.4147522-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.15 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Muna Sinada [ Upstream commit 1a4a6a22552ca9d723f28a1fe35eab1b9b3d8b33 ] Currently for MLO, sending out multicast frames on each link is handled by mac80211 only when IEEE80211_HW_MLO_MCAST_MULTI_LINK_TX flag is not set. Dynamic VLAN multicast traffic utilizes software encryption. Due to this, mac80211 should handle transmitting multicast frames on all links for multicast VLAN traffic. Signed-off-by: Muna Sinada Link: https://patch.msgid.link/20250325213125.1509362-4-muna.sinada@oss.qualcomm.com [remove unnecessary parentheses] Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- **YES** This commit should be backported to stable kernel trees. Here's my detailed analysis: ## Backporting Analysis: YES ### Nature of the Change This is a **targeted bug fix** that addresses a functional gap in MLO (Multi-Link Operation) multicast handling for AP_VLAN interfaces. The commit extends existing logic rather than introducing new features. ### Technical Assessment **The Problem Fixed:** The original code in `ieee80211_subif_start_xmit()` only handled `NL80211_IFTYPE_AP` interfaces for MLO multicast transmission, but completely missed `NL80211_IFTYPE_AP_VLAN` interfaces. This created a behavioral inconsistency where: - AP interfaces: Properly handled MLO multicast transmission via `ieee80211_mlo_multicast_tx()` - AP_VLAN interfaces: Fell through to normal transmission path, bypassing MLO multicast coordination **The Fix Applied:** ```c } else if (ieee80211_vif_is_mld(&sdata->vif) && - sdata->vif.type == NL80211_IFTYPE_AP && - !ieee80211_hw_check(&sdata->local->hw, MLO_MCAST_MULTI_LINK_TX)) { + ((sdata->vif.type == NL80211_IFTYPE_AP && + !ieee80211_hw_check(&sdata->local->hw, MLO_MCAST_MULTI_LINK_TX)) || + (sdata->vif.type == NL80211_IFTYPE_AP_VLAN && + !sdata->wdev.use_4addr))) { ``` This change: 1. **Extends existing conditional logic** to include AP_VLAN interfaces 2. **Uses existing infrastructure** (`ieee80211_mlo_multicast_tx()`) 3. **Adds proper validation** (excludes 4-address/WDS mode via `!use_4addr`) ### Risk Analysis: LOW RISK **Minimal Change Scope:** - Single conditional modification in well-established code path - No new functions, data structures, or APIs introduced - Uses existing MLO multicast transmission infrastructure **Well-Contained Impact:** - Only affects MLO multicast transmission for AP_VLAN interfaces - Preserved existing behavior for all other interface types - Added validation ensures appropriate application scope **Backward Compatibility:** - No changes to external interfaces or user-visible behavior - No impact on non-MLO or non-VLAN configurations - Maintains existing AP interface behavior unchanged ### Comparison with Similar Commits This commit aligns with **Similar Commit #4** (MLD address translation fix - Status: YES): - Both are targeted bug fixes for MLO functionality - Both address specific functional gaps rather than adding new features - Both use existing infrastructure to correct behavioral issues - Both have minimal risk profiles suitable for stable backporting **Contrasts with rejected commits:** - Unlike Similar Commits #1, #2: This is not implementing new MLO features - Unlike Similar Commit #3: This is not changing encapsulation behavior - Unlike Similar Commit #5: This is not removing functionality ### Production Impact **Functional Benefits:** - **Fixes MLO+VLAN deployments**: Enables proper multicast operation in combined MLO/VLAN environments - **Consistency**: Ensures uniform multicast handling across AP and AP_VLAN interface types - **Reliability**: Prevents potential multicast delivery issues in enterprise VLAN configurations **Real-World Relevance:** - AP_VLAN interfaces are commonly used in enterprise environments for traffic segmentation - MLO is increasingly deployed in Wi-Fi 7 scenarios - The combination creates practical deployment scenarios where this fix is needed ### Stable Tree Criteria Compliance ✅ **Important bug fix**: Addresses functional gap affecting MLO+VLAN deployments ✅ **Minimal risk**: Single conditional extension with clear validation ✅ **No architectural changes**: Uses existing MLO multicast infrastructure ✅ **Well-contained**: Affects only specific interface type in specific scenario ✅ **Production relevant**: Impacts real-world enterprise VLAN configurations This commit represents a clear bug fix that resolves a functional inconsistency in MLO multicast handling, making it well-suited for stable kernel backporting according to established criteria. net/mac80211/tx.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 20179db88c4a6..d6af02a524af3 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -4526,8 +4526,10 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb, IEEE80211_TX_CTRL_MLO_LINK_UNSPEC, NULL); } else if (ieee80211_vif_is_mld(&sdata->vif) && - sdata->vif.type == NL80211_IFTYPE_AP && - !ieee80211_hw_check(&sdata->local->hw, MLO_MCAST_MULTI_LINK_TX)) { + ((sdata->vif.type == NL80211_IFTYPE_AP && + !ieee80211_hw_check(&sdata->local->hw, MLO_MCAST_MULTI_LINK_TX)) || + (sdata->vif.type == NL80211_IFTYPE_AP_VLAN && + !sdata->wdev.use_4addr))) { ieee80211_mlo_multicast_tx(dev, skb); } else { normal: -- 2.39.5