| From: Felix Fietkau <nbd@nbd.name> |
| Date: Thu, 1 Dec 2022 14:57:30 +0100 |
| Subject: [PATCH] wifi: mac80211: fix and simplify unencrypted drop check for |
| mesh |
| |
| ieee80211_drop_unencrypted is called from ieee80211_rx_h_mesh_fwding and |
| ieee80211_frame_allowed. |
| |
| Since ieee80211_rx_h_mesh_fwding can forward packets for other mesh nodes |
| and is called earlier, it needs to check the decryptions status and if the |
| packet is using the control protocol on its own, instead of deferring to |
| the later call from ieee80211_frame_allowed. |
| |
| Because of that, ieee80211_drop_unencrypted has a mesh specific check |
| that skips over the mesh header in order to check the payload protocol. |
| This code is invalid when called from ieee80211_frame_allowed, since that |
| happens after the 802.11->802.3 conversion. |
| |
| Fix this by moving the mesh specific check directly into |
| ieee80211_rx_h_mesh_fwding. |
| |
| Signed-off-by: Felix Fietkau <nbd@nbd.name> |
| Link: https://lore.kernel.org/r/20221201135730.19723-1-nbd@nbd.name |
| Signed-off-by: Johannes Berg <johannes.berg@intel.com> |
| --- |
| |
| --- a/net/mac80211/rx.c |
| +++ b/net/mac80211/rx.c |
| @@ -2403,7 +2403,6 @@ static int ieee80211_802_1x_port_control |
| |
| static int ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc) |
| { |
| - struct ieee80211_hdr *hdr = (void *)rx->skb->data; |
| struct sk_buff *skb = rx->skb; |
| struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); |
| |
| @@ -2414,31 +2413,6 @@ static int ieee80211_drop_unencrypted(st |
| if (status->flag & RX_FLAG_DECRYPTED) |
| return 0; |
| |
| - /* check mesh EAPOL frames first */ |
| - if (unlikely(rx->sta && ieee80211_vif_is_mesh(&rx->sdata->vif) && |
| - ieee80211_is_data(fc))) { |
| - struct ieee80211s_hdr *mesh_hdr; |
| - u16 hdr_len = ieee80211_hdrlen(fc); |
| - u16 ethertype_offset; |
| - __be16 ethertype; |
| - |
| - if (!ether_addr_equal(hdr->addr1, rx->sdata->vif.addr)) |
| - goto drop_check; |
| - |
| - /* make sure fixed part of mesh header is there, also checks skb len */ |
| - if (!pskb_may_pull(rx->skb, hdr_len + 6)) |
| - goto drop_check; |
| - |
| - mesh_hdr = (struct ieee80211s_hdr *)(skb->data + hdr_len); |
| - ethertype_offset = hdr_len + ieee80211_get_mesh_hdrlen(mesh_hdr) + |
| - sizeof(rfc1042_header); |
| - |
| - if (skb_copy_bits(rx->skb, ethertype_offset, ðertype, 2) == 0 && |
| - ethertype == rx->sdata->control_port_protocol) |
| - return 0; |
| - } |
| - |
| -drop_check: |
| /* Drop unencrypted frames if key is set. */ |
| if (unlikely(!ieee80211_has_protected(fc) && |
| !ieee80211_is_any_nullfunc(fc) && |
| @@ -2892,8 +2866,16 @@ ieee80211_rx_h_mesh_fwding(struct ieee80 |
| hdr = (struct ieee80211_hdr *) skb->data; |
| mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen); |
| |
| - if (ieee80211_drop_unencrypted(rx, hdr->frame_control)) |
| - return RX_DROP_MONITOR; |
| + if (ieee80211_drop_unencrypted(rx, hdr->frame_control)) { |
| + int offset = hdrlen + ieee80211_get_mesh_hdrlen(mesh_hdr) + |
| + sizeof(rfc1042_header); |
| + __be16 ethertype; |
| + |
| + if (!ether_addr_equal(hdr->addr1, rx->sdata->vif.addr) || |
| + skb_copy_bits(rx->skb, offset, ðertype, 2) != 0 || |
| + ethertype != rx->sdata->control_port_protocol) |
| + return RX_DROP_MONITOR; |
| + } |
| |
| /* frame is in RMC, don't forward */ |
| if (ieee80211_is_data(hdr->frame_control) && |