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mac80211: support A-MSDU in fast-rx
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Only works if the IV was stripped from packets. Create a smaller
variant of ieee80211_rx_h_amsdu, which bypasses checks already done
within the fast-rx context.

In order to do so, update cfg80211's ieee80211_data_to_8023_exthdr()
to take the offset between header and snap.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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Felix Fietkau authored and Johannes Berg committed Feb 27, 2018
1 parent 21b7022 commit 24bba07
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Showing 3 changed files with 80 additions and 55 deletions.
6 changes: 4 additions & 2 deletions include/net/cfg80211.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -4410,10 +4410,12 @@ unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr);
* of it being pushed into the SKB
* @addr: the device MAC address
* @iftype: the virtual interface type
* @data_offset: offset of payload after the 802.11 header
* Return: 0 on success. Non-zero on error.
*/
int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
const u8 *addr, enum nl80211_iftype iftype);
const u8 *addr, enum nl80211_iftype iftype,
u8 data_offset);

/**
* ieee80211_data_to_8023 - convert an 802.11 data frame to 802.3
Expand All @@ -4425,7 +4427,7 @@ int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
static inline int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
enum nl80211_iftype iftype)
{
return ieee80211_data_to_8023_exthdr(skb, NULL, addr, iftype);
return ieee80211_data_to_8023_exthdr(skb, NULL, addr, iftype, 0);
}

/**
Expand Down
124 changes: 73 additions & 51 deletions net/mac80211/rx.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2353,39 +2353,17 @@ ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
}

static ieee80211_rx_result debug_noinline
ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
__ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx, u8 data_offset)
{
struct net_device *dev = rx->sdata->dev;
struct sk_buff *skb = rx->skb;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
__le16 fc = hdr->frame_control;
struct sk_buff_head frame_list;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
struct ethhdr ethhdr;
const u8 *check_da = ethhdr.h_dest, *check_sa = ethhdr.h_source;

if (unlikely(!ieee80211_is_data(fc)))
return RX_CONTINUE;

if (unlikely(!ieee80211_is_data_present(fc)))
return RX_DROP_MONITOR;

if (!(status->rx_flags & IEEE80211_RX_AMSDU))
return RX_CONTINUE;

if (unlikely(ieee80211_has_a4(hdr->frame_control))) {
switch (rx->sdata->vif.type) {
case NL80211_IFTYPE_AP_VLAN:
if (!rx->sdata->u.vlan.sta)
return RX_DROP_UNUSABLE;
break;
case NL80211_IFTYPE_STATION:
if (!rx->sdata->u.mgd.use_4addr)
return RX_DROP_UNUSABLE;
break;
default:
return RX_DROP_UNUSABLE;
}
check_da = NULL;
check_sa = NULL;
} else switch (rx->sdata->vif.type) {
Expand All @@ -2405,15 +2383,13 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
break;
}

if (is_multicast_ether_addr(hdr->addr1))
return RX_DROP_UNUSABLE;

skb->dev = dev;
__skb_queue_head_init(&frame_list);

if (ieee80211_data_to_8023_exthdr(skb, &ethhdr,
rx->sdata->vif.addr,
rx->sdata->vif.type))
rx->sdata->vif.type,
data_offset))
return RX_DROP_UNUSABLE;

ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
Expand All @@ -2435,6 +2411,44 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
return RX_QUEUED;
}

static ieee80211_rx_result debug_noinline
ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
{
struct sk_buff *skb = rx->skb;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
__le16 fc = hdr->frame_control;

if (!(status->rx_flags & IEEE80211_RX_AMSDU))
return RX_CONTINUE;

if (unlikely(!ieee80211_is_data(fc)))
return RX_CONTINUE;

if (unlikely(!ieee80211_is_data_present(fc)))
return RX_DROP_MONITOR;

if (unlikely(ieee80211_has_a4(hdr->frame_control))) {
switch (rx->sdata->vif.type) {
case NL80211_IFTYPE_AP_VLAN:
if (!rx->sdata->u.vlan.sta)
return RX_DROP_UNUSABLE;
break;
case NL80211_IFTYPE_STATION:
if (!rx->sdata->u.mgd.use_4addr)
return RX_DROP_UNUSABLE;
break;
default:
return RX_DROP_UNUSABLE;
}
}

if (is_multicast_ether_addr(hdr->addr1))
return RX_DROP_UNUSABLE;

return __ieee80211_rx_h_amsdu(rx, 0);
}

#ifdef CONFIG_MAC80211_MESH
static ieee80211_rx_result
ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
Expand Down Expand Up @@ -3898,7 +3912,8 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
struct sta_info *sta = rx->sta;
int orig_len = skb->len;
int snap_offs = ieee80211_hdrlen(hdr->frame_control);
int hdrlen = ieee80211_hdrlen(hdr->frame_control);
int snap_offs = hdrlen;
struct {
u8 snap[sizeof(rfc1042_header)];
__be16 proto;
Expand Down Expand Up @@ -3929,10 +3944,6 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
(status->flag & FAST_RX_CRYPT_FLAGS) != FAST_RX_CRYPT_FLAGS)
return false;

/* we don't deal with A-MSDU deaggregation here */
if (status->rx_flags & IEEE80211_RX_AMSDU)
return false;

if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
return false;

Expand Down Expand Up @@ -3964,21 +3975,24 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
snap_offs += IEEE80211_CCMP_HDR_LEN;
}

if (!pskb_may_pull(skb, snap_offs + sizeof(*payload)))
goto drop;
payload = (void *)(skb->data + snap_offs);
if (!(status->rx_flags & IEEE80211_RX_AMSDU)) {
if (!pskb_may_pull(skb, snap_offs + sizeof(*payload)))
goto drop;

if (!ether_addr_equal(payload->snap, fast_rx->rfc1042_hdr))
return false;
payload = (void *)(skb->data + snap_offs);

/* Don't handle these here since they require special code.
* Accept AARP and IPX even though they should come with a
* bridge-tunnel header - but if we get them this way then
* there's little point in discarding them.
*/
if (unlikely(payload->proto == cpu_to_be16(ETH_P_TDLS) ||
payload->proto == fast_rx->control_port_protocol))
return false;
if (!ether_addr_equal(payload->snap, fast_rx->rfc1042_hdr))
return false;

/* Don't handle these here since they require special code.
* Accept AARP and IPX even though they should come with a
* bridge-tunnel header - but if we get them this way then
* there's little point in discarding them.
*/
if (unlikely(payload->proto == cpu_to_be16(ETH_P_TDLS) ||
payload->proto == fast_rx->control_port_protocol))
return false;
}

/* after this point, don't punt to the slowpath! */

Expand All @@ -3992,12 +4006,6 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
}

/* statistics part of ieee80211_rx_h_sta_process() */
stats->last_rx = jiffies;
stats->last_rate = sta_stats_encode_rate(status);

stats->fragments++;
stats->packets++;

if (!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
stats->last_signal = status->signal;
if (!fast_rx->uses_rss)
Expand Down Expand Up @@ -4026,6 +4034,20 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
if (rx->key && !ieee80211_has_protected(hdr->frame_control))
goto drop;

if (status->rx_flags & IEEE80211_RX_AMSDU) {
if (__ieee80211_rx_h_amsdu(rx, snap_offs - hdrlen) !=
RX_QUEUED)
goto drop;

return true;
}

stats->last_rx = jiffies;
stats->last_rate = sta_stats_encode_rate(status);

stats->fragments++;
stats->packets++;

/* do the header conversion - first grab the addresses */
ether_addr_copy(addrs.da, skb->data + fast_rx->da_offs);
ether_addr_copy(addrs.sa, skb->data + fast_rx->sa_offs);
Expand Down
5 changes: 3 additions & 2 deletions net/wireless/util.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -420,7 +420,8 @@ unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
EXPORT_SYMBOL(ieee80211_get_mesh_hdrlen);

int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
const u8 *addr, enum nl80211_iftype iftype)
const u8 *addr, enum nl80211_iftype iftype,
u8 data_offset)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct {
Expand All @@ -434,7 +435,7 @@ int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
return -1;

hdrlen = ieee80211_hdrlen(hdr->frame_control);
hdrlen = ieee80211_hdrlen(hdr->frame_control) + data_offset;
if (skb->len < hdrlen + 8)
return -1;

Expand Down

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