wifi: mac80211: remove RX_DROP

Since it's hard to figure out what RX_DROP means when looking
at traces that drop packets in mac80211, add more specific drop
reasons and remove RX_DROP entirely.

Link: https://patch.msgid.link/20260116092025.79d995e87026.I7cde413988f7a382c551cd1c1e2b05a52ec71755@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/drop.h b/net/mac80211/drop.h
index eb9ab310f91caae59b8da9149eb6131b0d35c8c1..f06a8aa905c53c69dec0b9e6f93b624b9014d5aa 100644 (file)
--- a/net/mac80211/drop.h
+++ b/net/mac80211/drop.h
@@ -2,7 +2,7 @@
 /*
  * mac80211 drop reason list
  *
- * Copyright (C) 2023-2024 Intel Corporation
+ * Copyright (C) 2023-2024, 2026 Intel Corporation
  */
 
 #ifndef MAC80211_DROP_H
@@ -65,6 +65,49 @@ typedef unsigned int __bitwise ieee80211_rx_result;
        /* 0x30 */                              \
        R(RX_DROP_U_BAD_MGMT_KEYIDX)            \
        R(RX_DROP_U_UNKNOWN_ACTION_REJECTED)    \
+       R(RX_DROP_U_MESH_DS_BITS)               \
+       R(RX_DROP_U_MESH_A3_MISMATCH)           \
+       R(RX_DROP_U_MESH_NO_A4)                 \
+       R(RX_DROP_U_MESH_A4_MISMATCH)           \
+       R(RX_DROP_U_MESH_UNEXP_DATA)            \
+       R(RX_DROP_U_MESH_WRONG_ACTION)          \
+       R(RX_DROP_U_MESH_UNEXP_MGMT)            \
+       R(RX_DROP_U_SPURIOUS_NOTIF)             \
+       R(RX_DROP_U_RUNT_DATA)                  \
+       R(RX_DROP_U_KEY_TAINTED)                \
+       R(RX_DROP_U_UNPROTECTED)                \
+       R(RX_DROP_U_MCAST_FRAGMENT)             \
+       R(RX_DROP_U_DEFRAG_MISMATCH)            \
+       R(RX_DROP_U_RUNT_MESH_DATA)             \
+       /* 0x40 */                              \
+       R(RX_DROP_U_MESH_NO_TTL)                \
+       R(RX_DROP_U_MESH_RMC)                   \
+       R(RX_DROP_U_MESH_BAD_AE)                \
+       R(RX_DROP_U_MESH_TTL_EXPIRED)           \
+       R(RX_DROP_U_MESH_NOT_FORWARDING)        \
+       R(RX_DROP_U_AMSDU_WITHOUT_DATA)         \
+       R(RX_DROP_U_NULL_DATA)                  \
+       R(RX_DROP_U_UNEXPECTED_4ADDR)           \
+       R(RX_DROP_U_PORT_CONTROL)               \
+       R(RX_DROP_U_UNKNOWN_STA)                \
+       R(RX_DROP_U_RUNT_BAR)                   \
+       R(RX_DROP_U_BAR_OUTSIDE_SESSION)        \
+       R(RX_DROP_U_CTRL_FRAME)                 \
+       R(RX_DROP_U_RUNT_MGMT)                  \
+       R(RX_DROP_U_EXPECTED_MGMT)              \
+       R(RX_DROP_U_NONBCAST_BEACON)            \
+       /* 0x50 */                              \
+       R(RX_DROP_U_MALFORMED_ACTION)           \
+       R(RX_DROP_U_UNKNOWN_MCAST_ACTION)       \
+       R(RX_DROP_U_UNEXPECTED_EXT_FRAME)       \
+       R(RX_DROP_U_UNHANDLED_MGMT)             \
+       R(RX_DROP_U_MCAST_DEAUTH)               \
+       R(RX_DROP_U_UNHANDLED_DEAUTH)           \
+       R(RX_DROP_U_MCAST_DISASSOC)             \
+       R(RX_DROP_U_UNHANDLED_DISASSOC)         \
+       R(RX_DROP_U_UNHANDLED_PREQ)             \
+       R(RX_DROP_U_UNHANDLED_MGMT_STYPE)       \
+       R(RX_DROP_U_NO_LINK)                    \
 /* this line for the trailing \ - add before this */
 
 /* having two enums allows for checking ieee80211_rx_result use with sparse */
@@ -85,7 +128,6 @@ enum ___mac80211_drop_reason {
 enum mac80211_drop_reason {
        RX_CONTINUE     = (__force ieee80211_rx_result)___RX_CONTINUE,
        RX_QUEUED       = (__force ieee80211_rx_result)___RX_QUEUED,
-       RX_DROP         = (__force ieee80211_rx_result)___RX_DROP_UNUSABLE,
 #define DEF(x) x = (__force ieee80211_rx_result)___ ## x,
        MAC80211_DROP_REASONS_UNUSABLE(DEF)
 #undef DEF

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 9a2b0ef2f21a8da5c8a469301a29cdfd9b2740d4..ac437256f5d5c4b34601fd4c8a6f6f80469b2522 100644 (file)
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -6,7 +6,7 @@
  * Copyright 2007-2010 Johannes Berg <johannes@sipsolutions.net>
  * Copyright 2013-2014  Intel Mobile Communications GmbH
  * Copyright(c) 2015 - 2017 Intel Deutschland GmbH
- * Copyright (C) 2018-2025 Intel Corporation
+ * Copyright (C) 2018-2026 Intel Corporation
  */
 
 #include <linux/jiffies.h>
@@ -1137,14 +1137,14 @@ static ieee80211_rx_result ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
                if (is_multicast_ether_addr(hdr->addr1)) {
                        if (ieee80211_has_tods(hdr->frame_control) ||
                            !ieee80211_has_fromds(hdr->frame_control))
-                               return RX_DROP;
+                               return RX_DROP_U_MESH_DS_BITS;
                        if (ether_addr_equal(hdr->addr3, dev_addr))
-                               return RX_DROP;
+                               return RX_DROP_U_MESH_A3_MISMATCH;
                } else {
                        if (!ieee80211_has_a4(hdr->frame_control))
-                               return RX_DROP;
+                               return RX_DROP_U_MESH_NO_A4;
                        if (ether_addr_equal(hdr->addr4, dev_addr))
-                               return RX_DROP;
+                               return RX_DROP_U_MESH_A4_MISMATCH;
                }
        }
 
@@ -1156,20 +1156,20 @@ static ieee80211_rx_result ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
                struct ieee80211_mgmt *mgmt;
 
                if (!ieee80211_is_mgmt(hdr->frame_control))
-                       return RX_DROP;
+                       return RX_DROP_U_MESH_UNEXP_DATA;
 
                if (ieee80211_is_action(hdr->frame_control)) {
                        u8 category;
 
                        /* make sure category field is present */
                        if (rx->skb->len < IEEE80211_MIN_ACTION_SIZE)
-                               return RX_DROP;
+                               return RX_DROP_U_RUNT_ACTION;
 
                        mgmt = (struct ieee80211_mgmt *)hdr;
                        category = mgmt->u.action.category;
                        if (category != WLAN_CATEGORY_MESH_ACTION &&
                            category != WLAN_CATEGORY_SELF_PROTECTED)
-                               return RX_DROP;
+                               return RX_DROP_U_MESH_WRONG_ACTION;
                        return RX_CONTINUE;
                }
 
@@ -1179,7 +1179,7 @@ static ieee80211_rx_result ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
                    ieee80211_is_auth(hdr->frame_control))
                        return RX_CONTINUE;
 
-               return RX_DROP;
+               return RX_DROP_U_MESH_UNEXP_MGMT;
        }
 
        return RX_CONTINUE;
@@ -1605,7 +1605,7 @@ ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
                        hdrlen = ieee80211_hdrlen(hdr->frame_control);
 
                        if (rx->skb->len < hdrlen + 8)
-                               return RX_DROP;
+                               return RX_DROP_U_RUNT_DATA;
 
                        skb_copy_bits(rx->skb, hdrlen + 6, &ethertype, 2);
                        if (ethertype == rx->sdata->control_port_protocol)
@@ -1615,9 +1615,9 @@ ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
                if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
                    cfg80211_rx_spurious_frame(rx->sdata->dev, hdr->addr2,
                                               rx->link_id, GFP_ATOMIC))
-                       return RX_DROP_U_SPURIOUS;
+                       return RX_DROP_U_SPURIOUS_NOTIF;
 
-               return RX_DROP;
+               return RX_DROP_U_SPURIOUS;
        }
 
        return RX_CONTINUE;
@@ -2106,7 +2106,7 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
                if (rx->link_sta) {
                        if (ieee80211_is_group_privacy_action(skb) &&
                            test_sta_flag(rx->sta, WLAN_STA_MFP))
-                               return RX_DROP;
+                               return RX_DROP_U_UNPROTECTED;
 
                        rx->key = rcu_dereference(rx->link_sta->gtk[mmie_keyidx]);
                }
@@ -2191,11 +2191,11 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 
        if (rx->key) {
                if (unlikely(rx->key->flags & KEY_FLAG_TAINTED))
-                       return RX_DROP;
+                       return RX_DROP_U_KEY_TAINTED;
 
                /* TODO: add threshold stuff again */
        } else {
-               return RX_DROP;
+               return RX_DROP_U_UNPROTECTED;
        }
 
        switch (rx->key->conf.cipher) {
@@ -2371,7 +2371,7 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
                goto out;
 
        if (is_multicast_ether_addr(hdr->addr1))
-               return RX_DROP;
+               return RX_DROP_U_MCAST_FRAGMENT;
 
        I802_DEBUG_INC(rx->local->rx_handlers_fragments);
 
@@ -2426,7 +2426,7 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
                                          rx->seqno_idx, hdr);
        if (!entry) {
                I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
-               return RX_DROP;
+               return RX_DROP_U_DEFRAG_MISMATCH;
        }
 
        /* "The receiver shall discard MSDUs and MMPDUs whose constituent
@@ -2956,25 +2956,25 @@ ieee80211_rx_mesh_data(struct ieee80211_sub_if_data *sdata, struct sta_info *sta
                return RX_CONTINUE;
 
        if (!pskb_may_pull(skb, sizeof(*eth) + 6))
-               return RX_DROP;
+               return RX_DROP_U_RUNT_MESH_DATA;
 
        mesh_hdr = (struct ieee80211s_hdr *)(skb->data + sizeof(*eth));
        mesh_hdrlen = ieee80211_get_mesh_hdrlen(mesh_hdr);
 
        if (!pskb_may_pull(skb, sizeof(*eth) + mesh_hdrlen))
-               return RX_DROP;
+               return RX_DROP_U_RUNT_MESH_DATA;
 
        eth = (struct ethhdr *)skb->data;
        multicast = is_multicast_ether_addr(eth->h_dest);
 
        mesh_hdr = (struct ieee80211s_hdr *)(eth + 1);
        if (!mesh_hdr->ttl)
-               return RX_DROP;
+               return RX_DROP_U_MESH_NO_TTL;
 
        /* frame is in RMC, don't forward */
        if (is_multicast_ether_addr(eth->h_dest) &&
            mesh_rmc_check(sdata, eth->h_source, mesh_hdr))
-               return RX_DROP;
+               return RX_DROP_U_MESH_RMC;
 
        /* forward packet */
        if (sdata->crypto_tx_tailroom_needed_cnt)
@@ -2991,7 +2991,7 @@ ieee80211_rx_mesh_data(struct ieee80211_sub_if_data *sdata, struct sta_info *sta
                        /* has_a4 already checked in ieee80211_rx_mesh_check */
                        proxied_addr = mesh_hdr->eaddr2;
                else
-                       return RX_DROP;
+                       return RX_DROP_U_MESH_BAD_AE;
 
                rcu_read_lock();
                mppath = mpp_path_lookup(sdata, proxied_addr);
@@ -3023,14 +3023,14 @@ ieee80211_rx_mesh_data(struct ieee80211_sub_if_data *sdata, struct sta_info *sta
                        goto rx_accept;
 
                IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_ttl);
-               return RX_DROP;
+               return RX_DROP_U_MESH_TTL_EXPIRED;
        }
 
        if (!ifmsh->mshcfg.dot11MeshForwarding) {
                if (is_multicast_ether_addr(eth->h_dest))
                        goto rx_accept;
 
-               return RX_DROP;
+               return RX_DROP_U_MESH_NOT_FORWARDING;
        }
 
        skb_set_queue_mapping(skb, ieee802_1d_to_ac[skb->priority]);
@@ -3216,7 +3216,7 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
                return RX_CONTINUE;
 
        if (unlikely(!ieee80211_is_data_present(fc)))
-               return RX_DROP;
+               return RX_DROP_U_AMSDU_WITHOUT_DATA;
 
        if (unlikely(ieee80211_has_a4(hdr->frame_control))) {
                switch (rx->sdata->vif.type) {
@@ -3273,7 +3273,7 @@ ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
                return RX_CONTINUE;
 
        if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
-               return RX_DROP;
+               return RX_DROP_U_NULL_DATA;
 
        /* Send unexpected-4addr-frame event to hostapd */
        if (ieee80211_has_a4(hdr->frame_control) &&
@@ -3283,7 +3283,7 @@ ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
                        cfg80211_rx_unexpected_4addr_frame(
                                rx->sdata->dev, rx->sta->sta.addr, rx->link_id,
                                GFP_ATOMIC);
-               return RX_DROP;
+               return RX_DROP_U_UNEXPECTED_4ADDR;
        }
 
        res = __ieee80211_data_to_8023(rx, &port_control);
@@ -3295,7 +3295,7 @@ ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
                return res;
 
        if (!ieee80211_frame_allowed(rx, fc))
-               return RX_DROP;
+               return RX_DROP_U_PORT_CONTROL;
 
        /* directly handle TDLS channel switch requests/responses */
        if (unlikely(((struct ethhdr *)rx->skb->data)->h_proto ==
@@ -3360,11 +3360,11 @@ ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
                };
 
                if (!rx->sta)
-                       return RX_DROP;
+                       return RX_DROP_U_UNKNOWN_STA;
 
                if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
                                  &bar_data, sizeof(bar_data)))
-                       return RX_DROP;
+                       return RX_DROP_U_RUNT_BAR;
 
                tid = le16_to_cpu(bar_data.control) >> 12;
 
@@ -3376,7 +3376,7 @@ ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
 
                tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
                if (!tid_agg_rx)
-                       return RX_DROP;
+                       return RX_DROP_U_BAR_OUTSIDE_SESSION;
 
                start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
                event.u.ba.tid = tid;
@@ -3400,7 +3400,7 @@ ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
                return RX_QUEUED;
        }
 
-       return RX_DROP;
+       return RX_DROP_U_CTRL_FRAME;
 }
 
 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
@@ -3509,10 +3509,10 @@ ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
         * and unknown (reserved) frames are useless.
         */
        if (rx->skb->len < 24)
-               return RX_DROP;
+               return RX_DROP_U_RUNT_MGMT;
 
        if (!ieee80211_is_mgmt(mgmt->frame_control))
-               return RX_DROP;
+               return RX_DROP_U_EXPECTED_MGMT;
 
        /* drop too small action frames */
        if (ieee80211_is_action(mgmt->frame_control) &&
@@ -3522,7 +3522,7 @@ ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
        /* Drop non-broadcast Beacon frames */
        if (ieee80211_is_beacon(mgmt->frame_control) &&
            !is_broadcast_ether_addr(mgmt->da))
-               return RX_DROP;
+               return RX_DROP_U_NONBCAST_BEACON;
 
        if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
            ieee80211_is_beacon(mgmt->frame_control) &&
@@ -4054,10 +4054,10 @@ ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
        if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
            (sdata->vif.type == NL80211_IFTYPE_AP ||
             sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
-               return RX_DROP;
+               return RX_DROP_U_MALFORMED_ACTION;
 
        if (is_multicast_ether_addr(mgmt->da))
-               return RX_DROP;
+               return RX_DROP_U_UNKNOWN_MCAST_ACTION;
 
        /* do not return rejected action frames */
        if (mgmt->u.action.category & 0x80)
@@ -4102,7 +4102,7 @@ ieee80211_rx_h_ext(struct ieee80211_rx_data *rx)
                return RX_CONTINUE;
 
        if (sdata->vif.type != NL80211_IFTYPE_STATION)
-               return RX_DROP;
+               return RX_DROP_U_UNEXPECTED_EXT_FRAME;
 
        /* for now only beacons are ext, so queue them */
        ieee80211_queue_skb_to_iface(sdata, rx->link_id, rx->sta, rx->skb);
@@ -4123,7 +4123,7 @@ ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
            sdata->vif.type != NL80211_IFTYPE_ADHOC &&
            sdata->vif.type != NL80211_IFTYPE_OCB &&
            sdata->vif.type != NL80211_IFTYPE_STATION)
-               return RX_DROP;
+               return RX_DROP_U_UNHANDLED_MGMT;
 
        switch (stype) {
        case cpu_to_le16(IEEE80211_STYPE_AUTH):
@@ -4134,32 +4134,32 @@ ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
        case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
                if (is_multicast_ether_addr(mgmt->da) &&
                    !is_broadcast_ether_addr(mgmt->da))
-                       return RX_DROP;
+                       return RX_DROP_U_MCAST_DEAUTH;
 
                /* process only for station/IBSS */
                if (sdata->vif.type != NL80211_IFTYPE_STATION &&
                    sdata->vif.type != NL80211_IFTYPE_ADHOC)
-                       return RX_DROP;
+                       return RX_DROP_U_UNHANDLED_DEAUTH;
                break;
        case cpu_to_le16(IEEE80211_STYPE_ASSOC_RESP):
        case cpu_to_le16(IEEE80211_STYPE_REASSOC_RESP):
        case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
                if (is_multicast_ether_addr(mgmt->da) &&
                    !is_broadcast_ether_addr(mgmt->da))
-                       return RX_DROP;
+                       return RX_DROP_U_MCAST_DISASSOC;
 
                /* process only for station */
                if (sdata->vif.type != NL80211_IFTYPE_STATION)
-                       return RX_DROP;
+                       return RX_DROP_U_UNHANDLED_DISASSOC;
                break;
        case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
                /* process only for ibss and mesh */
                if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
                    sdata->vif.type != NL80211_IFTYPE_MESH_POINT)
-                       return RX_DROP;
+                       return RX_DROP_U_UNHANDLED_PREQ;
                break;
        default:
-               return RX_DROP;
+               return RX_DROP_U_UNHANDLED_MGMT_STYPE;
        }
 
        ieee80211_queue_skb_to_iface(sdata, rx->link_id, rx->sta, rx->skb);
@@ -4187,7 +4187,7 @@ static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx,
                                  struct sk_buff_head *frames)
 {
-       ieee80211_rx_result res = RX_DROP;
+       ieee80211_rx_result res;
        struct sk_buff *skb;
 
 #define CALL_RXH(rxh)                  \
@@ -4213,8 +4213,10 @@ static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx,
                 */
                rx->skb = skb;
 
-               if (WARN_ON_ONCE(!rx->link))
+               if (WARN_ON_ONCE(!rx->link)) {
+                       res = RX_DROP_U_NO_LINK;
                        goto rxh_next;
+               }
 
                CALL_RXH(ieee80211_rx_h_check_more_data);
                CALL_RXH(ieee80211_rx_h_uapsd_and_pspoll);
@@ -4251,7 +4253,7 @@ static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx,
 static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
 {
        struct sk_buff_head reorder_release;
-       ieee80211_rx_result res = RX_DROP;
+       ieee80211_rx_result res;
 
        __skb_queue_head_init(&reorder_release);