2020-12-18 20:46:25

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH v2 6/6] mac80211: add rx decapsulation offload support

This allows drivers to pass 802.3 frames to mac80211, with some restrictions:

- the skb must be passed with a valid sta
- fast-rx needs to be active for the sta
- monitor mode needs to be disabled

mac80211 will tell the driver when it is safe to enable rx decap offload for
a particular station.

In order to implement support, a driver must:

- call ieee80211_hw_set(hw, SUPPORTS_RX_DECAP_OFFLOAD)
- implement ops->sta_set_decap_offload
- mark 802.3 frames with RX_FLAG_8023

If it doesn't want to enable offload for some vif types, it can mask out
IEEE80211_OFFLOAD_DECAP_ENABLED in vif->offload_flags from within the
.add_interface or .update_vif_offload driver ops

Signed-off-by: Felix Fietkau <[email protected]>
---
v2: rename ieee80211_iftype_supports_encap_offload to
ieee80211_iftype_supports_hdr_offload

include/net/mac80211.h | 16 +++
net/mac80211/debugfs.c | 1 +
net/mac80211/debugfs_sta.c | 1 +
net/mac80211/driver-ops.h | 16 +++
net/mac80211/iface.c | 17 ++-
net/mac80211/rx.c | 243 ++++++++++++++++++++++++-------------
net/mac80211/sta_info.h | 2 +
net/mac80211/trace.h | 18 ++-
8 files changed, 225 insertions(+), 89 deletions(-)

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index d315740581f1..296d39e93a13 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1296,6 +1296,8 @@ ieee80211_tx_info_clear_status(struct ieee80211_tx_info *info)
* the "0-length PSDU" field included there. The value for it is
* in &struct ieee80211_rx_status. Note that if this value isn't
* known the frame shouldn't be reported.
+ * @RX_FLAG_8023: the frame has an 802.3 header (decap offload performed by
+ * hardware or driver)
*/
enum mac80211_rx_flags {
RX_FLAG_MMIC_ERROR = BIT(0),
@@ -1328,6 +1330,7 @@ enum mac80211_rx_flags {
RX_FLAG_RADIOTAP_HE_MU = BIT(27),
RX_FLAG_RADIOTAP_LSIG = BIT(28),
RX_FLAG_NO_PSDU = BIT(29),
+ RX_FLAG_8023 = BIT(30),
};

/**
@@ -1649,11 +1652,15 @@ enum ieee80211_vif_flags {
* The driver supports sending frames passed as 802.3 frames by mac80211.
* It must also support sending 802.11 packets for the same interface.
* @IEEE80211_OFFLOAD_ENCAP_4ADDR: support 4-address mode encapsulation offload
+ * @IEEE80211_OFFLOAD_DECAP_ENABLED: rx encapsulation offload is enabled
+ * The driver supports passing received 802.11 frames as 802.3 frames to
+ * mac80211.
*/

enum ieee80211_offload_flags {
IEEE80211_OFFLOAD_ENCAP_ENABLED = BIT(0),
IEEE80211_OFFLOAD_ENCAP_4ADDR = BIT(1),
+ IEEE80211_OFFLOAD_DECAP_ENABLED = BIT(2),
};

/**
@@ -2389,6 +2396,9 @@ struct ieee80211_txq {
* @IEEE80211_HW_SUPPORTS_TX_ENCAP_OFFLOAD: Hardware supports tx encapsulation
* offload
*
+ * @IEEE80211_HW_SUPPORTS_RX_DECAP_OFFLOAD: Hardware supports rx decapsulation
+ * offload
+ *
* @NUM_IEEE80211_HW_FLAGS: number of hardware flags, used for sizing arrays
*/
enum ieee80211_hw_flags {
@@ -2442,6 +2452,7 @@ enum ieee80211_hw_flags {
IEEE80211_HW_SUPPORTS_ONLY_HE_MULTI_BSSID,
IEEE80211_HW_AMPDU_KEYBORDER_SUPPORT,
IEEE80211_HW_SUPPORTS_TX_ENCAP_OFFLOAD,
+ IEEE80211_HW_SUPPORTS_RX_DECAP_OFFLOAD,

/* keep last, obviously */
NUM_IEEE80211_HW_FLAGS
@@ -3880,6 +3891,8 @@ enum ieee80211_reconfig_type {
* This callback may sleep.
* @sta_set_4addr: Called to notify the driver when a station starts/stops using
* 4-address mode
+ * @sta_set_decap_offload: Called to notify the driver when a station is allowed
+ * to use rx decapsulation offload
*/
struct ieee80211_ops {
void (*tx)(struct ieee80211_hw *hw,
@@ -4197,6 +4210,9 @@ struct ieee80211_ops {
struct ieee80211_sta *sta, bool enabled);
int (*set_sar_specs)(struct ieee80211_hw *hw,
const struct cfg80211_sar_specs *sar);
+ void (*sta_set_decap_offload)(struct ieee80211_hw *hw,
+ struct ieee80211_vif *vif,
+ struct ieee80211_sta *sta, bool enabled);
};

/**
diff --git a/net/mac80211/debugfs.c b/net/mac80211/debugfs.c
index 48f144f107d5..60e5994e3ea3 100644
--- a/net/mac80211/debugfs.c
+++ b/net/mac80211/debugfs.c
@@ -409,6 +409,7 @@ static const char *hw_flag_names[] = {
FLAG(SUPPORTS_ONLY_HE_MULTI_BSSID),
FLAG(AMPDU_KEYBORDER_SUPPORT),
FLAG(SUPPORTS_TX_ENCAP_OFFLOAD),
+ FLAG(SUPPORTS_RX_DECAP_OFFLOAD),
#undef FLAG
};

diff --git a/net/mac80211/debugfs_sta.c b/net/mac80211/debugfs_sta.c
index eb4bb79d936a..5a27c61a7b38 100644
--- a/net/mac80211/debugfs_sta.c
+++ b/net/mac80211/debugfs_sta.c
@@ -79,6 +79,7 @@ static const char * const sta_flag_names[] = {
FLAG(MPSP_RECIPIENT),
FLAG(PS_DELIVER),
FLAG(USES_ENCRYPTION),
+ FLAG(DECAP_OFFLOAD),
#undef FLAG
};

diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index bcdfd19a596b..604ca59937f0 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -1413,4 +1413,20 @@ static inline void drv_sta_set_4addr(struct ieee80211_local *local,
trace_drv_return_void(local);
}

+static inline void drv_sta_set_decap_offload(struct ieee80211_local *local,
+ struct ieee80211_sub_if_data *sdata,
+ struct ieee80211_sta *sta,
+ bool enabled)
+{
+ sdata = get_bss_sdata(sdata);
+ if (!check_sdata_in_driver(sdata))
+ return;
+
+ trace_drv_sta_set_decap_offload(local, sdata, sta, enabled);
+ if (local->ops->sta_set_decap_offload)
+ local->ops->sta_set_decap_offload(&local->hw, &sdata->vif, sta,
+ enabled);
+ trace_drv_return_void(local);
+}
+
#endif /* __MAC80211_DRIVER_OPS */
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 3b9ec4ef81c3..1b44690823aa 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -765,7 +765,7 @@ static const struct net_device_ops ieee80211_dataif_8023_ops = {
.ndo_get_stats64 = ieee80211_get_stats64,
};

-static bool ieee80211_iftype_supports_encap_offload(enum nl80211_iftype iftype)
+static bool ieee80211_iftype_supports_hdr_offload(enum nl80211_iftype iftype)
{
switch (iftype) {
/* P2P GO and client are mapped to AP/STATION types */
@@ -785,7 +785,7 @@ static bool ieee80211_set_sdata_offload_flags(struct ieee80211_sub_if_data *sdat
flags = sdata->vif.offload_flags;

if (ieee80211_hw_check(&local->hw, SUPPORTS_TX_ENCAP_OFFLOAD) &&
- ieee80211_iftype_supports_encap_offload(sdata->vif.type)) {
+ ieee80211_iftype_supports_hdr_offload(sdata->vif.type)) {
flags |= IEEE80211_OFFLOAD_ENCAP_ENABLED;

if (!ieee80211_hw_check(&local->hw, SUPPORTS_TX_FRAG) &&
@@ -798,10 +798,21 @@ static bool ieee80211_set_sdata_offload_flags(struct ieee80211_sub_if_data *sdat
flags &= ~IEEE80211_OFFLOAD_ENCAP_ENABLED;
}

+ if (ieee80211_hw_check(&local->hw, SUPPORTS_RX_DECAP_OFFLOAD) &&
+ ieee80211_iftype_supports_hdr_offload(sdata->vif.type)) {
+ flags |= IEEE80211_OFFLOAD_DECAP_ENABLED;
+
+ if (local->monitors)
+ flags &= ~IEEE80211_OFFLOAD_DECAP_ENABLED;
+ } else {
+ flags &= ~IEEE80211_OFFLOAD_DECAP_ENABLED;
+ }
+
if (sdata->vif.offload_flags == flags)
return false;

sdata->vif.offload_flags = flags;
+ ieee80211_check_fast_rx_iface(sdata);
return true;
}

@@ -819,7 +830,7 @@ static void ieee80211_set_vif_encap_ops(struct ieee80211_sub_if_data *sdata)
}

if (!ieee80211_hw_check(&local->hw, SUPPORTS_TX_ENCAP_OFFLOAD) ||
- !ieee80211_iftype_supports_encap_offload(bss->vif.type))
+ !ieee80211_iftype_supports_hdr_offload(bss->vif.type))
return;

enabled = bss->vif.offload_flags & IEEE80211_OFFLOAD_ENCAP_ENABLED;
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 972895e9f22d..c1343c028b76 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -4095,7 +4095,9 @@ void ieee80211_check_fast_rx(struct sta_info *sta)
.vif_type = sdata->vif.type,
.control_port_protocol = sdata->control_port_protocol,
}, *old, *new = NULL;
+ bool set_offload = false;
bool assign = false;
+ bool offload;

/* use sparse to check that we don't return without updating */
__acquire(check_fast_rx);
@@ -4208,6 +4210,17 @@ void ieee80211_check_fast_rx(struct sta_info *sta)
if (assign)
new = kmemdup(&fastrx, sizeof(fastrx), GFP_KERNEL);

+ offload = assign &&
+ (sdata->vif.offload_flags & IEEE80211_OFFLOAD_DECAP_ENABLED);
+
+ if (offload)
+ set_offload = !test_and_set_sta_flag(sta, WLAN_STA_DECAP_OFFLOAD);
+ else
+ set_offload = test_and_clear_sta_flag(sta, WLAN_STA_DECAP_OFFLOAD);
+
+ if (set_offload)
+ drv_sta_set_decap_offload(local, sdata, &sta->sta, assign);
+
spin_lock_bh(&sta->lock);
old = rcu_dereference_protected(sta->fast_rx, true);
rcu_assign_pointer(sta->fast_rx, new);
@@ -4254,6 +4267,104 @@ void ieee80211_check_fast_rx_iface(struct ieee80211_sub_if_data *sdata)
mutex_unlock(&local->sta_mtx);
}

+static void ieee80211_rx_8023(struct ieee80211_rx_data *rx,
+ struct ieee80211_fast_rx *fast_rx,
+ int orig_len)
+{
+ struct ieee80211_sta_rx_stats *stats;
+ struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
+ struct sta_info *sta = rx->sta;
+ struct sk_buff *skb = rx->skb;
+ void *sa = skb->data + ETH_ALEN;
+ void *da = skb->data;
+
+ stats = &sta->rx_stats;
+ if (fast_rx->uses_rss)
+ stats = this_cpu_ptr(sta->pcpu_rx_stats);
+
+ /* statistics part of ieee80211_rx_h_sta_process() */
+ if (!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
+ stats->last_signal = status->signal;
+ if (!fast_rx->uses_rss)
+ ewma_signal_add(&sta->rx_stats_avg.signal,
+ -status->signal);
+ }
+
+ if (status->chains) {
+ int i;
+
+ stats->chains = status->chains;
+ for (i = 0; i < ARRAY_SIZE(status->chain_signal); i++) {
+ int signal = status->chain_signal[i];
+
+ if (!(status->chains & BIT(i)))
+ continue;
+
+ stats->chain_signal_last[i] = signal;
+ if (!fast_rx->uses_rss)
+ ewma_signal_add(&sta->rx_stats_avg.chain_signal[i],
+ -signal);
+ }
+ }
+ /* end of statistics */
+
+ stats->last_rx = jiffies;
+ stats->last_rate = sta_stats_encode_rate(status);
+
+ stats->fragments++;
+ stats->packets++;
+
+ skb->dev = fast_rx->dev;
+
+ dev_sw_netstats_rx_add(fast_rx->dev, skb->len);
+
+ /* The seqno index has the same property as needed
+ * for the rx_msdu field, i.e. it is IEEE80211_NUM_TIDS
+ * for non-QoS-data frames. Here we know it's a data
+ * frame, so count MSDUs.
+ */
+ u64_stats_update_begin(&stats->syncp);
+ stats->msdu[rx->seqno_idx]++;
+ stats->bytes += orig_len;
+ u64_stats_update_end(&stats->syncp);
+
+ if (fast_rx->internal_forward) {
+ struct sk_buff *xmit_skb = NULL;
+ if (is_multicast_ether_addr(da)) {
+ xmit_skb = skb_copy(skb, GFP_ATOMIC);
+ } else if (!ether_addr_equal(da, sa) &&
+ sta_info_get(rx->sdata, da)) {
+ xmit_skb = skb;
+ skb = NULL;
+ }
+
+ if (xmit_skb) {
+ /*
+ * Send to wireless media and increase priority by 256
+ * to keep the received priority instead of
+ * reclassifying the frame (see cfg80211_classify8021d).
+ */
+ xmit_skb->priority += 256;
+ xmit_skb->protocol = htons(ETH_P_802_3);
+ skb_reset_network_header(xmit_skb);
+ skb_reset_mac_header(xmit_skb);
+ dev_queue_xmit(xmit_skb);
+ }
+
+ if (!skb)
+ return;
+ }
+
+ /* deliver to local stack */
+ skb->protocol = eth_type_trans(skb, fast_rx->dev);
+ memset(skb->cb, 0, sizeof(skb->cb));
+ if (rx->list)
+ list_add_tail(&skb->list, rx->list);
+ else
+ netif_receive_skb(skb);
+
+}
+
static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
struct ieee80211_fast_rx *fast_rx)
{
@@ -4274,9 +4385,6 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
} addrs __aligned(2);
struct ieee80211_sta_rx_stats *stats = &sta->rx_stats;

- if (fast_rx->uses_rss)
- stats = this_cpu_ptr(sta->pcpu_rx_stats);
-
/* for parallel-rx, we need to have DUP_VALIDATED, otherwise we write
* to a common data structure; drivers can implement that per queue
* but we don't have that information in mac80211
@@ -4350,32 +4458,6 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
pskb_trim(skb, skb->len - fast_rx->icv_len))
goto drop;

- /* statistics part of ieee80211_rx_h_sta_process() */
- if (!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
- stats->last_signal = status->signal;
- if (!fast_rx->uses_rss)
- ewma_signal_add(&sta->rx_stats_avg.signal,
- -status->signal);
- }
-
- if (status->chains) {
- int i;
-
- stats->chains = status->chains;
- for (i = 0; i < ARRAY_SIZE(status->chain_signal); i++) {
- int signal = status->chain_signal[i];
-
- if (!(status->chains & BIT(i)))
- continue;
-
- stats->chain_signal_last[i] = signal;
- if (!fast_rx->uses_rss)
- ewma_signal_add(&sta->rx_stats_avg.chain_signal[i],
- -signal);
- }
- }
- /* end of statistics */
-
if (rx->key && !ieee80211_has_protected(hdr->frame_control))
goto drop;

@@ -4387,12 +4469,6 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
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);
@@ -4401,58 +4477,14 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
/* push the addresses in front */
memcpy(skb_push(skb, sizeof(addrs)), &addrs, sizeof(addrs));

- skb->dev = fast_rx->dev;
-
- dev_sw_netstats_rx_add(fast_rx->dev, skb->len);
-
- /* The seqno index has the same property as needed
- * for the rx_msdu field, i.e. it is IEEE80211_NUM_TIDS
- * for non-QoS-data frames. Here we know it's a data
- * frame, so count MSDUs.
- */
- u64_stats_update_begin(&stats->syncp);
- stats->msdu[rx->seqno_idx]++;
- stats->bytes += orig_len;
- u64_stats_update_end(&stats->syncp);
-
- if (fast_rx->internal_forward) {
- struct sk_buff *xmit_skb = NULL;
- if (is_multicast_ether_addr(addrs.da)) {
- xmit_skb = skb_copy(skb, GFP_ATOMIC);
- } else if (!ether_addr_equal(addrs.da, addrs.sa) &&
- sta_info_get(rx->sdata, addrs.da)) {
- xmit_skb = skb;
- skb = NULL;
- }
-
- if (xmit_skb) {
- /*
- * Send to wireless media and increase priority by 256
- * to keep the received priority instead of
- * reclassifying the frame (see cfg80211_classify8021d).
- */
- xmit_skb->priority += 256;
- xmit_skb->protocol = htons(ETH_P_802_3);
- skb_reset_network_header(xmit_skb);
- skb_reset_mac_header(xmit_skb);
- dev_queue_xmit(xmit_skb);
- }
-
- if (!skb)
- return true;
- }
-
- /* deliver to local stack */
- skb->protocol = eth_type_trans(skb, fast_rx->dev);
- memset(skb->cb, 0, sizeof(skb->cb));
- if (rx->list)
- list_add_tail(&skb->list, rx->list);
- else
- netif_receive_skb(skb);
+ ieee80211_rx_8023(rx, fast_rx, orig_len);

return true;
drop:
dev_kfree_skb(skb);
+ if (fast_rx->uses_rss)
+ stats = this_cpu_ptr(sta->pcpu_rx_stats);
+
stats->dropped++;
return true;
}
@@ -4506,6 +4538,43 @@ static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
return true;
}

+static void __ieee80211_rx_handle_8023(struct ieee80211_hw *hw,
+ struct ieee80211_sta *pubsta,
+ struct sk_buff *skb,
+ struct list_head *list)
+{
+ struct ieee80211_local *local = hw_to_local(hw);
+ struct ieee80211_fast_rx *fast_rx;
+ struct ieee80211_rx_data rx;
+
+ memset(&rx, 0, sizeof(rx));
+ rx.skb = skb;
+ rx.local = local;
+ rx.list = list;
+
+ I802_DEBUG_INC(local->dot11ReceivedFragmentCount);
+
+ /* drop frame if too short for header */
+ if (skb->len < sizeof(struct ethhdr))
+ goto drop;
+
+ if (!pubsta)
+ goto drop;
+
+ rx.sta = container_of(pubsta, struct sta_info, sta);
+ rx.sdata = rx.sta->sdata;
+
+ fast_rx = rcu_dereference(rx.sta->fast_rx);
+ if (!fast_rx)
+ goto drop;
+
+ ieee80211_rx_8023(&rx, fast_rx, skb->len);
+ return;
+
+drop:
+ dev_kfree_skb(skb);
+}
+
/*
* This is the actual Rx frames handler. as it belongs to Rx path it must
* be called with rcu_read_lock protection.
@@ -4737,13 +4806,17 @@ void ieee80211_rx_list(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta,
* if it was previously present.
* Also, frames with less than 16 bytes are dropped.
*/
- skb = ieee80211_rx_monitor(local, skb, rate);
+ if (!(status->flag & RX_FLAG_8023))
+ skb = ieee80211_rx_monitor(local, skb, rate);
if (skb) {
ieee80211_tpt_led_trig_rx(local,
((struct ieee80211_hdr *)skb->data)->frame_control,
skb->len);

- __ieee80211_rx_handle_packet(hw, pubsta, skb, list);
+ if (status->flag & RX_FLAG_8023)
+ __ieee80211_rx_handle_8023(hw, pubsta, skb, list);
+ else
+ __ieee80211_rx_handle_packet(hw, pubsta, skb, list);
}

kcov_remote_stop();
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 7afd07636b81..78b9d0c7cc58 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -71,6 +71,7 @@
* until pending frames are delivered
* @WLAN_STA_USES_ENCRYPTION: This station was configured for encryption,
* so drop all packets without a key later.
+ * @WLAN_STA_DECAP_OFFLOAD: This station uses rx decap offload
*
* @NUM_WLAN_STA_FLAGS: number of defined flags
*/
@@ -102,6 +103,7 @@ enum ieee80211_sta_info_flags {
WLAN_STA_MPSP_RECIPIENT,
WLAN_STA_PS_DELIVER,
WLAN_STA_USES_ENCRYPTION,
+ WLAN_STA_DECAP_OFFLOAD,

NUM_WLAN_STA_FLAGS,
};
diff --git a/net/mac80211/trace.h b/net/mac80211/trace.h
index 601322e16957..8fcc39056402 100644
--- a/net/mac80211/trace.h
+++ b/net/mac80211/trace.h
@@ -2761,7 +2761,7 @@ DEFINE_EVENT(local_sdata_addr_evt, drv_update_vif_offload,
TP_ARGS(local, sdata)
);

-TRACE_EVENT(drv_sta_set_4addr,
+DECLARE_EVENT_CLASS(sta_flag_evt,
TP_PROTO(struct ieee80211_local *local,
struct ieee80211_sub_if_data *sdata,
struct ieee80211_sta *sta, bool enabled),
@@ -2788,6 +2788,22 @@ TRACE_EVENT(drv_sta_set_4addr,
)
);

+DEFINE_EVENT(sta_flag_evt, drv_sta_set_4addr,
+ TP_PROTO(struct ieee80211_local *local,
+ struct ieee80211_sub_if_data *sdata,
+ struct ieee80211_sta *sta, bool enabled),
+
+ TP_ARGS(local, sdata, sta, enabled)
+);
+
+DEFINE_EVENT(sta_flag_evt, drv_sta_set_decap_offload,
+ TP_PROTO(struct ieee80211_local *local,
+ struct ieee80211_sub_if_data *sdata,
+ struct ieee80211_sta *sta, bool enabled),
+
+ TP_ARGS(local, sdata, sta, enabled)
+);
+
#endif /* !__MAC80211_DRIVER_TRACE || TRACE_HEADER_MULTI_READ */

#undef TRACE_INCLUDE_PATH
--
2.28.0