When using WPA security, the station and thus the required key is identified by its mac address when packets are received. So a station usually cannot spoof its source mac address.
But when a station sends an A-MSDU frame, port control and crypto is done using the outer mac address, while the packets delivered and forwarded use the inner mac address. This might affect ARP/IP filtering on the AccessPoint. IEEE 802.11-2012 mandates that the outer source mac address should match the inner source address (section 8.3.2.2). For the destination mac address, matching is not required, as a wifi client may send all its traffic to the AP in order to have it forwarded. Signed-off-by: Michael Braun <[email protected]> To: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] v4: check for IBSS, STATION, TDLS data frame --- drivers/net/wireless/intel/iwlwifi/mvm/d3.c | 3 +- .../net/wireless/marvell/mwifiex/11n_rxreorder.c | 3 +- drivers/staging/rtl8723au/core/rtw_recv.c | 2 +- include/net/cfg80211.h | 16 ++++--- net/mac80211/rx.c | 25 ++++++++--- net/wireless/util.c | 52 +++++++++++++++------- 6 files changed, 70 insertions(+), 31 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/d3.c b/drivers/net/wireless/intel/iwlwifi/mvm/d3.c index 4fdc3da..05dcaef 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/d3.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/d3.c @@ -1436,7 +1436,8 @@ static void iwl_mvm_report_wakeup_reasons(struct iwl_mvm *mvm, memcpy(skb_put(pkt, pktsize), pktdata, pktsize); - if (ieee80211_data_to_8023(pkt, vif->addr, vif->type)) + if (ieee80211_data_to_8023(pkt, NULL, vif->addr, + vif->type)) goto report; wakeup.packet = pkt->data; wakeup.packet_present_len = pkt->len; diff --git a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c index a74cc43..298e447 100644 --- a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c +++ b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c @@ -45,7 +45,8 @@ static int mwifiex_11n_dispatch_amsdu_pkt(struct mwifiex_private *priv, skb_trim(skb, le16_to_cpu(local_rx_pd->rx_pkt_length)); ieee80211_amsdu_to_8023s(skb, &list, priv->curr_addr, - priv->wdev.iftype, 0, false); + priv->wdev.iftype, 0, NULL, NULL, 0, + 0); while (!skb_queue_empty(&list)) { struct rx_packet_hdr *rx_hdr; diff --git a/drivers/staging/rtl8723au/core/rtw_recv.c b/drivers/staging/rtl8723au/core/rtw_recv.c index 150dabc..8f39a8b 100644 --- a/drivers/staging/rtl8723au/core/rtw_recv.c +++ b/drivers/staging/rtl8723au/core/rtw_recv.c @@ -1687,7 +1687,7 @@ int amsdu_to_msdu(struct rtw_adapter *padapter, struct recv_frame *prframe) skb_pull(skb, prframe->attrib.hdrlen); __skb_queue_head_init(&skb_list); - ieee80211_amsdu_to_8023s(skb, &skb_list, NULL, 0, 0, false); + ieee80211_amsdu_to_8023s(skb, &skb_list, NULL, 0, 0, NULL, NULL, 0, 0); while (!skb_queue_empty(&skb_list)) { sub_skb = __skb_dequeue(&skb_list); diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index beb7610..b550314 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -3905,12 +3905,13 @@ unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr); /** * ieee80211_data_to_8023 - convert an 802.11 data frame to 802.3 * @skb: the 802.11 data frame + * @ehdr: (out) buffer for source/destination address (optional) * @addr: the device MAC address * @iftype: the virtual interface type * Return: 0 on success. Non-zero on error. */ -int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr, - enum nl80211_iftype iftype); +int ieee80211_data_to_8023(struct sk_buff *skb, struct ethhdr *ehdr, + const u8 *addr, enum nl80211_iftype iftype); /** * ieee80211_data_from_8023 - convert an 802.3 frame to 802.11 @@ -3938,12 +3939,17 @@ int ieee80211_data_from_8023(struct sk_buff *skb, const u8 *addr, * @addr: The device MAC address. * @iftype: The device interface type. * @extra_headroom: The hardware extra headroom for SKBs in the @list. - * @has_80211_header: Set it true if SKB is with IEEE 802.11 header. + * @ta: transmitter address (or NULL) + * @ra: receiver address (or NULL) + * @is_4addr: indicates that interface is in 4addr mode + * @is_tlds_data: indicates that frame as been received from TLDS peer */ void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list, - const u8 *addr, enum nl80211_iftype iftype, + const u8 *addr, + enum nl80211_iftype iftype, const unsigned int extra_headroom, - bool has_80211_header); + const u8 *ta, const u8 *ra, bool is_4addr, + bool is_tdls_data); /** * cfg80211_classify8021d - determine the 802.1p/1d tag for a data frame diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 9dce3b1..3d8d889 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -2090,7 +2090,8 @@ __ieee80211_data_to_8023(struct ieee80211_rx_data *rx, bool *port_control) sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta) return -1; - ret = ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type); + ret = ieee80211_data_to_8023(rx->skb, NULL, sdata->vif.addr, + sdata->vif.type); if (ret < 0) return ret; @@ -2243,6 +2244,9 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx) __le16 fc = hdr->frame_control; struct sk_buff_head frame_list; struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb); + struct ethhdr eth_80211; + bool is_4addr; + bool is_tdls_data; if (unlikely(!ieee80211_is_data(fc))) return RX_CONTINUE; @@ -2258,19 +2262,26 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx) !rx->sdata->u.vlan.sta) return RX_DROP_UNUSABLE; - if (is_multicast_ether_addr(hdr->addr1) && - ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN && - rx->sdata->u.vlan.sta) || - (rx->sdata->vif.type == NL80211_IFTYPE_STATION && - rx->sdata->u.mgd.use_4addr))) + is_4addr = ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN && + rx->sdata->u.vlan.sta) || + (rx->sdata->vif.type == NL80211_IFTYPE_STATION && + rx->sdata->u.mgd.use_4addr)); + if (is_multicast_ether_addr(hdr->addr1) && is_4addr) return RX_DROP_UNUSABLE; skb->dev = dev; __skb_queue_head_init(&frame_list); + if (ieee80211_data_to_8023(skb, ð_80211, dev->dev_addr, + rx->sdata->vif.type) < 0) + return RX_DROP_UNUSABLE; + + is_tdls_data = !ieee80211_has_tods(fc) && !ieee80211_has_fromds(fc); ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr, rx->sdata->vif.type, - rx->local->hw.extra_tx_headroom, true); + rx->local->hw.extra_tx_headroom, + eth_80211.h_source, + eth_80211.h_dest, is_4addr, is_tdls_data); while (!skb_queue_empty(&frame_list)) { rx->skb = __skb_dequeue(&frame_list); diff --git a/net/wireless/util.c b/net/wireless/util.c index b7d1592..84da5c2 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -414,8 +414,8 @@ unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr) } EXPORT_SYMBOL(ieee80211_get_mesh_hdrlen); -static int __ieee80211_data_to_8023(struct sk_buff *skb, struct ethhdr *ehdr, - const u8 *addr, enum nl80211_iftype iftype) +int ieee80211_data_to_8023(struct sk_buff *skb, struct ethhdr *ehdr, + const u8 *addr, enum nl80211_iftype iftype) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; struct { @@ -519,12 +519,6 @@ static int __ieee80211_data_to_8023(struct sk_buff *skb, struct ethhdr *ehdr, return 0; } - -int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr, - enum nl80211_iftype iftype) -{ - return __ieee80211_data_to_8023(skb, NULL, addr, iftype); -} EXPORT_SYMBOL(ieee80211_data_to_8023); int ieee80211_data_from_8023(struct sk_buff *skb, const u8 *addr, @@ -738,24 +732,41 @@ __ieee80211_amsdu_copy(struct sk_buff *skb, unsigned int hlen, } void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list, - const u8 *addr, enum nl80211_iftype iftype, + const u8 *addr, + enum nl80211_iftype iftype, const unsigned int extra_headroom, - bool has_80211_header) + const u8 *ta, const u8 *ra, bool is_4addr, + bool is_tdls_data) { unsigned int hlen = ALIGN(extra_headroom, 4); struct sk_buff *frame = NULL; u16 ethertype; u8 *payload; - int offset = 0, remaining, err; + int offset = 0, remaining; struct ethhdr eth; bool reuse_frag = skb->head_frag && !skb_has_frag_list(skb); bool reuse_skb = false; bool last = false; - if (has_80211_header) { - err = __ieee80211_data_to_8023(skb, ð, addr, iftype); - if (err) - goto out; + /* limit inner src/dst checks depending on iftype */ + switch (iftype) { + case NL80211_IFTYPE_AP: + case NL80211_IFTYPE_AP_VLAN: + if (is_4addr) + ta = NULL; + ra = NULL; + break; + case NL80211_IFTYPE_ADHOC: + break; + case NL80211_IFTYPE_STATION: + if (is_4addr || !is_tdls_data) + ta = NULL; + if (is_4addr) + ra = NULL; + break; + default: + ta = NULL; + ra = NULL; } while (!last) { @@ -768,6 +779,16 @@ void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list, subframe_len = sizeof(struct ethhdr) + len; padding = (4 - subframe_len) & 0x3; + if (unlikely(ta && !ether_addr_equal(ta, eth.h_source))) + goto purge; + /* for unicast frames, we accept multicast inner MSDUs + * to enable multicast to unicast conversion + */ + if (unlikely(ra && !ether_addr_equal(ra, eth.h_dest) && + (is_multicast_ether_addr(ra) || + !is_multicast_ether_addr(eth.h_dest)))) + goto purge; + /* the last MSDU has no padding */ remaining = skb->len - offset; if (subframe_len > remaining) @@ -813,7 +834,6 @@ void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list, purge: __skb_queue_purge(list); - out: dev_kfree_skb(skb); } EXPORT_SYMBOL(ieee80211_amsdu_to_8023s); -- 2.1.4
