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From:   Felix Fietkau <nbd@nbd.name>
To:     linux-wireless@vger.kernel.org
Cc:     johannes@sipsolutions.net,
        =?UTF-8?q?Thomas=20H=C3=BChn?= <thomas.huehn@hs-nordhausen.de>,
        Nick Hainke <vincent@systemli.org>
Subject: [PATCH] wifi: mac80211: fix receiving mesh packets in forwarding=0 networks
Date:   Sun, 26 Mar 2023 17:17:09 +0200
Message-Id: <20230326151709.17743-1-nbd@nbd.name>
MIME-Version: 1.0
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Precedence: bulk

When forwarding is set to 0, frames are typically sent with ttl=1.
Move the ttl decrement check below the check for local receive in order to
fix packet drops.

Reported-by: Thomas Hühn <thomas.huehn@hs-nordhausen.de>
Reported-by: Nick Hainke <vincent@systemli.org>
Fixes: 986e43b19ae9 ("wifi: mac80211: fix receiving A-MSDU frames on mesh interfaces")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 net/mac80211/rx.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index bab839a0f59a..7e270eaeef72 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2769,14 +2769,6 @@ ieee80211_rx_mesh_data(struct ieee80211_sub_if_data *sdata, struct sta_info *sta
 	if (sdata->crypto_tx_tailroom_needed_cnt)
 		tailroom = IEEE80211_ENCRYPT_TAILROOM;
 
-	if (!--mesh_hdr->ttl) {
-		if (multicast)
-			goto rx_accept;
-
-		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_ttl);
-		return RX_DROP_MONITOR;
-	}
-
 	if (mesh_hdr->flags & MESH_FLAGS_AE) {
 		struct mesh_path *mppath;
 		char *proxied_addr;
@@ -2807,6 +2799,14 @@ ieee80211_rx_mesh_data(struct ieee80211_sub_if_data *sdata, struct sta_info *sta
 	if (ether_addr_equal(sdata->vif.addr, eth->h_dest))
 		goto rx_accept;
 
+	if (!--mesh_hdr->ttl) {
+		if (multicast)
+			goto rx_accept;
+
+		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_ttl);
+		return RX_DROP_MONITOR;
+	}
+
 	if (!ifmsh->mshcfg.dot11MeshForwarding) {
 		if (is_multicast_ether_addr(eth->h_dest))
 			goto rx_accept;
-- 
2.39.0