Mac80211 drivers can now pass paged SKBs to mac80211 via
ieee80211_rx{_irqsafe}. The implementation currently use
skb_linearize() in a few places i.e. management frame
handling, software decryption, defragmentation and A-MSDU
process. We will optimize them one by one later.
Signed-off-by: Zhu Yi <[email protected]>
Cc: Kalle Valo <[email protected]>
Cc: Johannes Berg <[email protected]>
---
V2: add comments for paged skb support
fix pskb_may_pull size for ieee80211 and mesh header
use RX_DROP_UNUSABLE instead of RX_DROP_MONITOR
include/net/mac80211.h | 5 ++++-
net/mac80211/rx.c | 36 ++++++++++++++++++++++++++++++++----
net/wireless/util.c | 8 +++++++-
3 files changed, 43 insertions(+), 6 deletions(-)
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 1a8f50a..ecaae10 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1822,7 +1822,10 @@ void ieee80211_restart_hw(struct ieee80211_hw *hw);
* ieee80211_rx - receive frame
*
* Use this function to hand received frames to mac80211. The receive
- * buffer in @skb must start with an IEEE 802.11 header.
+ * buffer in @skb must start with an IEEE 802.11 header. In case of a
+ * paged @skb is used, the driver is recommended to put the ieee80211
+ * header of the frame on the linear part of the @skb to avoid memory
+ * allocation and/or memcpy by the stack.
*
* This function may not be called in IRQ context. Calls to this function
* for a single hardware must be synchronized against each other. Calls to
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 1da57c8..11ed5aa 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -38,7 +38,7 @@ static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
{
if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
if (likely(skb->len > FCS_LEN))
- skb_trim(skb, skb->len - FCS_LEN);
+ __pskb_trim(skb, skb->len - FCS_LEN);
else {
/* driver bug */
WARN_ON(1);
@@ -227,6 +227,12 @@ ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
present_fcs_len = FCS_LEN;
+ /* make sure hdr->frame_control is on the linear part */
+ if (!pskb_may_pull(origskb, 2)) {
+ dev_kfree_skb(origskb);
+ return NULL;
+ }
+
if (!local->monitors) {
if (should_drop_frame(origskb, present_fcs_len)) {
dev_kfree_skb(origskb);
@@ -931,6 +937,9 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
return RX_DROP_MONITOR;
}
+ if (skb_linearize(rx->skb))
+ return RX_DROP_UNUSABLE;
+
/* Check for weak IVs if possible */
if (rx->sta && rx->key->conf.alg == ALG_WEP &&
ieee80211_is_data(hdr->frame_control) &&
@@ -1231,6 +1240,9 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
}
I802_DEBUG_INC(rx->local->rx_handlers_fragments);
+ if (skb_linearize(rx->skb))
+ return RX_DROP_UNUSABLE;
+
seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
if (frag == 0) {
@@ -1588,6 +1600,9 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
skb->dev = dev;
__skb_queue_head_init(&frame_list);
+ if (skb_linearize(skb))
+ return RX_DROP_UNUSABLE;
+
ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
rx->sdata->vif.type,
rx->local->hw.extra_tx_headroom);
@@ -2357,29 +2372,42 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_sub_if_data *sdata;
struct ieee80211_hdr *hdr;
+ __le16 fc;
struct ieee80211_rx_data rx;
int prepares;
struct ieee80211_sub_if_data *prev = NULL;
struct sk_buff *skb_new;
struct sta_info *sta, *tmp;
bool found_sta = false;
+ int err = 0;
- hdr = (struct ieee80211_hdr *)skb->data;
+ fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
memset(&rx, 0, sizeof(rx));
rx.skb = skb;
rx.local = local;
- if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
+ if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
local->dot11ReceivedFragmentCount++;
if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
rx.flags |= IEEE80211_RX_IN_SCAN;
+ if (ieee80211_is_mgmt(fc))
+ err = skb_linearize(skb);
+ else
+ err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
+
+ if (err) {
+ dev_kfree_skb(skb);
+ return;
+ }
+
+ hdr = (struct ieee80211_hdr *)skb->data;
ieee80211_parse_qos(&rx);
ieee80211_verify_alignment(&rx);
- if (ieee80211_is_data(hdr->frame_control)) {
+ if (ieee80211_is_data(fc)) {
for_each_sta_info(local, hdr->addr2, sta, tmp) {
rx.sta = sta;
found_sta = true;
diff --git a/net/wireless/util.c b/net/wireless/util.c
index be2ab8c..63c60b9 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -330,6 +330,9 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
if (iftype == NL80211_IFTYPE_MESH_POINT) {
struct ieee80211s_hdr *meshdr =
(struct ieee80211s_hdr *) (skb->data + hdrlen);
+ /* make sure meshdr->flags is on the linear part */
+ if (!pskb_may_pull(skb, hdrlen + 1))
+ return -1;
hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
memcpy(dst, meshdr->eaddr1, ETH_ALEN);
@@ -346,6 +349,9 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
if (iftype == NL80211_IFTYPE_MESH_POINT) {
struct ieee80211s_hdr *meshdr =
(struct ieee80211s_hdr *) (skb->data + hdrlen);
+ /* make sure meshdr->flags is on the linear part */
+ if (!pskb_may_pull(skb, hdrlen + 1))
+ return -1;
hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
if (meshdr->flags & MESH_FLAGS_AE_A4)
memcpy(src, meshdr->eaddr1, ETH_ALEN);
@@ -357,7 +363,7 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
break;
}
- if (unlikely(skb->len - hdrlen < 8))
+ if (!pskb_may_pull(skb, hdrlen + 8))
return -1;
payload = skb->data + hdrlen;
--
1.6.3.3
Zhu Yi <[email protected]> writes:
> Mac80211 drivers can now pass paged SKBs to mac80211 via
> ieee80211_rx{_irqsafe}. The implementation currently use
> skb_linearize() in a few places i.e. management frame
> handling, software decryption, defragmentation and A-MSDU
> process. We will optimize them one by one later.
[...]
> --- a/include/net/mac80211.h
> +++ b/include/net/mac80211.h
> @@ -1822,7 +1822,10 @@ void ieee80211_restart_hw(struct ieee80211_hw *hw);
> * ieee80211_rx - receive frame
> *
> * Use this function to hand received frames to mac80211. The receive
> - * buffer in @skb must start with an IEEE 802.11 header.
> + * buffer in @skb must start with an IEEE 802.11 header. In case of a
> + * paged @skb is used, the driver is recommended to put the ieee80211
> + * header of the frame on the linear part of the @skb to avoid memory
> + * allocation and/or memcpy by the stack.
This is much better now. Thank you.
--
Kalle Valo
Remove skb_linearize() in the iwlwifi drivers since
mac80211 supports paged rx SKBs now.
Signed-off-by: Zhu Yi <[email protected]>
---
V2: add iwl3945 driver support
drivers/net/wireless/iwlwifi/iwl-3945.c | 29 +--------------------------
drivers/net/wireless/iwlwifi/iwl-dev.h | 7 ------
drivers/net/wireless/iwlwifi/iwl-rx.c | 32 +-----------------------------
3 files changed, 4 insertions(+), 64 deletions(-)
diff --git a/drivers/net/wireless/iwlwifi/iwl-3945.c b/drivers/net/wireless/iwlwifi/iwl-3945.c
index 3b5889d..55b0599 100644
--- a/drivers/net/wireless/iwlwifi/iwl-3945.c
+++ b/drivers/net/wireless/iwlwifi/iwl-3945.c
@@ -548,7 +548,6 @@ static void iwl3945_pass_packet_to_mac80211(struct iwl_priv *priv,
struct iwl3945_rx_frame_end *rx_end = IWL_RX_END(pkt);
u16 len = le16_to_cpu(rx_hdr->len);
struct sk_buff *skb;
- int ret;
__le16 fc = hdr->frame_control;
/* We received data from the HW, so stop the watchdog */
@@ -565,9 +564,9 @@ static void iwl3945_pass_packet_to_mac80211(struct iwl_priv *priv,
return;
}
- skb = alloc_skb(IWL_LINK_HDR_MAX * 2, GFP_ATOMIC);
+ skb = dev_alloc_skb(128);
if (!skb) {
- IWL_ERR(priv, "alloc_skb failed\n");
+ IWL_ERR(priv, "dev_alloc_skb failed\n");
return;
}
@@ -576,37 +575,13 @@ static void iwl3945_pass_packet_to_mac80211(struct iwl_priv *priv,
(struct ieee80211_hdr *)rxb_addr(rxb),
le32_to_cpu(rx_end->status), stats);
- skb_reserve(skb, IWL_LINK_HDR_MAX);
skb_add_rx_frag(skb, 0, rxb->page,
(void *)rx_hdr->payload - (void *)pkt, len);
- /* mac80211 currently doesn't support paged SKB. Convert it to
- * linear SKB for management frame and data frame requires
- * software decryption or software defragementation. */
- if (ieee80211_is_mgmt(fc) ||
- ieee80211_has_protected(fc) ||
- ieee80211_has_morefrags(fc) ||
- le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG)
- ret = skb_linearize(skb);
- else
- ret = __pskb_pull_tail(skb, min_t(u16, IWL_LINK_HDR_MAX, len)) ?
- 0 : -ENOMEM;
-
- if (ret) {
- kfree_skb(skb);
- goto out;
- }
-
- /*
- * XXX: We cannot touch the page and its virtual memory (pkt) after
- * here. It might have already been freed by the above skb change.
- */
-
iwl_update_stats(priv, false, fc, len);
memcpy(IEEE80211_SKB_RXCB(skb), stats, sizeof(*stats));
ieee80211_rx(priv->hw, skb);
- out:
priv->alloc_rxb_page--;
rxb->page = NULL;
}
diff --git a/drivers/net/wireless/iwlwifi/iwl-dev.h b/drivers/net/wireless/iwlwifi/iwl-dev.h
index e847e61..c2b907d 100644
--- a/drivers/net/wireless/iwlwifi/iwl-dev.h
+++ b/drivers/net/wireless/iwlwifi/iwl-dev.h
@@ -363,13 +363,6 @@ enum {
#define DEF_CMD_PAYLOAD_SIZE 320
-/*
- * IWL_LINK_HDR_MAX should include ieee80211_hdr, radiotap header,
- * SNAP header and alignment. It should also be big enough for 802.11
- * control frames.
- */
-#define IWL_LINK_HDR_MAX 64
-
/**
* struct iwl_device_cmd
*
diff --git a/drivers/net/wireless/iwlwifi/iwl-rx.c b/drivers/net/wireless/iwlwifi/iwl-rx.c
index 2fa30df..062f6fc 100644
--- a/drivers/net/wireless/iwlwifi/iwl-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-rx.c
@@ -1077,7 +1077,6 @@ static void iwl_pass_packet_to_mac80211(struct iwl_priv *priv,
struct ieee80211_rx_status *stats)
{
struct sk_buff *skb;
- int ret = 0;
__le16 fc = hdr->frame_control;
/* We only process data packets if the interface is open */
@@ -1092,45 +1091,18 @@ static void iwl_pass_packet_to_mac80211(struct iwl_priv *priv,
iwl_set_decrypted_flag(priv, hdr, ampdu_status, stats))
return;
- skb = alloc_skb(IWL_LINK_HDR_MAX * 2, GFP_ATOMIC);
+ skb = dev_alloc_skb(128);
if (!skb) {
- IWL_ERR(priv, "alloc_skb failed\n");
+ IWL_ERR(priv, "dev_alloc_skb failed\n");
return;
}
- skb_reserve(skb, IWL_LINK_HDR_MAX);
skb_add_rx_frag(skb, 0, rxb->page, (void *)hdr - rxb_addr(rxb), len);
- /* mac80211 currently doesn't support paged SKB. Convert it to
- * linear SKB for management frame and data frame requires
- * software decryption or software defragementation. */
- if (ieee80211_is_mgmt(fc) ||
- ieee80211_has_protected(fc) ||
- ieee80211_has_morefrags(fc) ||
- le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG ||
- (ieee80211_is_data_qos(fc) &&
- *ieee80211_get_qos_ctl(hdr) &
- IEEE80211_QOS_CONTROL_A_MSDU_PRESENT))
- ret = skb_linearize(skb);
- else
- ret = __pskb_pull_tail(skb, min_t(u16, IWL_LINK_HDR_MAX, len)) ?
- 0 : -ENOMEM;
-
- if (ret) {
- kfree_skb(skb);
- goto out;
- }
-
- /*
- * XXX: We cannot touch the page and its virtual memory (hdr) after
- * here. It might have already been freed by the above skb change.
- */
-
iwl_update_stats(priv, false, fc, len);
memcpy(IEEE80211_SKB_RXCB(skb), stats, sizeof(*stats));
ieee80211_rx(priv->hw, skb);
- out:
priv->alloc_rxb_page--;
rxb->page = NULL;
}
--
1.6.3.3