| developer | 88605f7 | 2023-02-15 16:38:49 +0800 | [diff] [blame] | 1 | From: Felix Fietkau <nbd@nbd.name> |
| 2 | Date: Thu, 1 Dec 2022 14:57:30 +0100 |
| 3 | Subject: [PATCH] wifi: mac80211: fix and simplify unencrypted drop check for |
| 4 | mesh |
| 5 | |
| 6 | ieee80211_drop_unencrypted is called from ieee80211_rx_h_mesh_fwding and |
| 7 | ieee80211_frame_allowed. |
| 8 | |
| 9 | Since ieee80211_rx_h_mesh_fwding can forward packets for other mesh nodes |
| 10 | and is called earlier, it needs to check the decryptions status and if the |
| 11 | packet is using the control protocol on its own, instead of deferring to |
| 12 | the later call from ieee80211_frame_allowed. |
| 13 | |
| 14 | Because of that, ieee80211_drop_unencrypted has a mesh specific check |
| 15 | that skips over the mesh header in order to check the payload protocol. |
| 16 | This code is invalid when called from ieee80211_frame_allowed, since that |
| 17 | happens after the 802.11->802.3 conversion. |
| 18 | |
| 19 | Fix this by moving the mesh specific check directly into |
| 20 | ieee80211_rx_h_mesh_fwding. |
| 21 | |
| 22 | Signed-off-by: Felix Fietkau <nbd@nbd.name> |
| 23 | Link: https://lore.kernel.org/r/20221201135730.19723-1-nbd@nbd.name |
| 24 | Signed-off-by: Johannes Berg <johannes.berg@intel.com> |
| 25 | --- |
| 26 | |
| 27 | --- a/net/mac80211/rx.c |
| 28 | +++ b/net/mac80211/rx.c |
| 29 | @@ -2403,7 +2403,6 @@ static int ieee80211_802_1x_port_control |
| 30 | |
| 31 | static int ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc) |
| 32 | { |
| 33 | - struct ieee80211_hdr *hdr = (void *)rx->skb->data; |
| 34 | struct sk_buff *skb = rx->skb; |
| 35 | struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); |
| 36 | |
| 37 | @@ -2414,31 +2413,6 @@ static int ieee80211_drop_unencrypted(st |
| 38 | if (status->flag & RX_FLAG_DECRYPTED) |
| 39 | return 0; |
| 40 | |
| 41 | - /* check mesh EAPOL frames first */ |
| 42 | - if (unlikely(rx->sta && ieee80211_vif_is_mesh(&rx->sdata->vif) && |
| 43 | - ieee80211_is_data(fc))) { |
| 44 | - struct ieee80211s_hdr *mesh_hdr; |
| 45 | - u16 hdr_len = ieee80211_hdrlen(fc); |
| 46 | - u16 ethertype_offset; |
| 47 | - __be16 ethertype; |
| 48 | - |
| 49 | - if (!ether_addr_equal(hdr->addr1, rx->sdata->vif.addr)) |
| 50 | - goto drop_check; |
| 51 | - |
| 52 | - /* make sure fixed part of mesh header is there, also checks skb len */ |
| 53 | - if (!pskb_may_pull(rx->skb, hdr_len + 6)) |
| 54 | - goto drop_check; |
| 55 | - |
| 56 | - mesh_hdr = (struct ieee80211s_hdr *)(skb->data + hdr_len); |
| 57 | - ethertype_offset = hdr_len + ieee80211_get_mesh_hdrlen(mesh_hdr) + |
| 58 | - sizeof(rfc1042_header); |
| 59 | - |
| 60 | - if (skb_copy_bits(rx->skb, ethertype_offset, ðertype, 2) == 0 && |
| 61 | - ethertype == rx->sdata->control_port_protocol) |
| 62 | - return 0; |
| 63 | - } |
| 64 | - |
| 65 | -drop_check: |
| 66 | /* Drop unencrypted frames if key is set. */ |
| 67 | if (unlikely(!ieee80211_has_protected(fc) && |
| 68 | !ieee80211_is_any_nullfunc(fc) && |
| 69 | @@ -2892,8 +2866,16 @@ ieee80211_rx_h_mesh_fwding(struct ieee80 |
| 70 | hdr = (struct ieee80211_hdr *) skb->data; |
| 71 | mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen); |
| 72 | |
| 73 | - if (ieee80211_drop_unencrypted(rx, hdr->frame_control)) |
| 74 | - return RX_DROP_MONITOR; |
| 75 | + if (ieee80211_drop_unencrypted(rx, hdr->frame_control)) { |
| 76 | + int offset = hdrlen + ieee80211_get_mesh_hdrlen(mesh_hdr) + |
| 77 | + sizeof(rfc1042_header); |
| 78 | + __be16 ethertype; |
| 79 | + |
| 80 | + if (!ether_addr_equal(hdr->addr1, rx->sdata->vif.addr) || |
| 81 | + skb_copy_bits(rx->skb, offset, ðertype, 2) != 0 || |
| 82 | + ethertype != rx->sdata->control_port_protocol) |
| 83 | + return RX_DROP_MONITOR; |
| 84 | + } |
| 85 | |
| 86 | /* frame is in RMC, don't forward */ |
| 87 | if (ieee80211_is_data(hdr->frame_control) && |