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 1DE701B423B; Wed, 4 Jun 2025 00:58:06 +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=1748998687; cv=none; b=d6DmK37pCpyHOfWJpB5wSqAaq7PuA6R6lMMO+8bj8W76OrmffBRPBwBrl6Qx2UbFKFqz9/GQoCFTQWYSc/hmzwmaRcUe3Qg3fgvFo0wvQeCbbWbseNVrCmC1JjK37Zx/OnYZ5l6bq+CkoKeqtvAplrc4nTj3qpn9T1adjX7kY6g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748998687; c=relaxed/simple; bh=9pG1U9ANVSrNaTTsjQNPkP1eyDMGQN6LcHtLTBaC2LY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=SGrlmuaPslEpEaBS0ZgbfjzXSI325fI9AmJZEV0ILi5a6L7fCy3PPZCQkmdJT05tZzllO28mTh/oJXkawknajZhyFVb9PsMXY2oh4dJVoHMBQdelJCPa0NmbFbh6gEBfMHg8VZAB9jCM4w0uesVv8PfjRs1UFCIxcIj6QKBlqEY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CoAVV7fr; 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="CoAVV7fr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B96CFC4CEF2; Wed, 4 Jun 2025 00:58:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1748998686; bh=9pG1U9ANVSrNaTTsjQNPkP1eyDMGQN6LcHtLTBaC2LY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CoAVV7frN+HxfV1uLCYvSPhatexW+R5T0ZKLWgrJjyjUKMU1mevZz9cEtAPLYpoz7 Le308YUIttskqqW3oWvkeGO7mBqMU2oi8KYMVzbws8qf5dJmOabTzLhPuiK/V6/MTE RID+G/wVW4ZSb4lmQyZmy1G9RF9MmmmY9To/SpGR2aKvehFWz3jeXm3Cbrdsw83nJN 7XwACVCnT5o/LWH+AvQVgCf76mh07L5MSCspW+2qMqj+crWNTHTcO2xPOOzVDmPtOC JR2Uzdxf9i7vRpcjQaWH0mfuiwnCUTmLwkovUW2Ds+IwnPXwdgRTSLzx83/0HI7fTf PJ83M5mNlSY9w== 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 6.14 074/108] wifi: mac80211: VLAN traffic in multicast path Date: Tue, 3 Jun 2025 20:54:57 -0400 Message-Id: <20250604005531.4178547-74-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250604005531.4178547-1-sashal@kernel.org> References: <20250604005531.4178547-1-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 6.14.9 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 1289df373795e..caf4d8561a219 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -4525,8 +4525,10 @@ 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