Commit e3cf8b3f authored by Zhu Yi's avatar Zhu Yi Committed by John W. Linville
Browse files

mac80211: support paged rx SKBs 



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: default avatarZhu Yi <yi.zhu@intel.com>
Cc: Kalle Valo <kalle.valo@iki.fi>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent e58b1253

include/net/mac80211.h

+4 −1
Original line number Diff line number Diff line
@@ -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

net/mac80211/rx.c

+32 −4
Original line number Diff line number Diff line
@@ -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;

net/wireless/util.c

+18 −6
Original line number Diff line number Diff line
@@ -330,11 +330,18 @@ 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);

			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);

			/* make sure meshdr->flags is on the linear part */

			if (!pskb_may_pull(skb, hdrlen + 1))

				return -1;

			if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {

				memcpy(dst, meshdr->eaddr1, ETH_ALEN);

				memcpy(src, meshdr->eaddr2, ETH_ALEN);

				skb_copy_bits(skb, hdrlen +

					offsetof(struct ieee80211s_hdr, eaddr1),

				       	dst, ETH_ALEN);

				skb_copy_bits(skb, hdrlen +

					offsetof(struct ieee80211s_hdr, eaddr2),

				        src, ETH_ALEN);

			}

			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);

		}

		break;

	case cpu_to_le16(IEEE80211_FCTL_FROMDS):
@@ -346,9 +353,14 @@ 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);

			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);

			/* make sure meshdr->flags is on the linear part */

			if (!pskb_may_pull(skb, hdrlen + 1))

				return -1;

			if (meshdr->flags & MESH_FLAGS_AE_A4)

				memcpy(src, meshdr->eaddr1, ETH_ALEN);

				skb_copy_bits(skb, hdrlen +

					offsetof(struct ieee80211s_hdr, eaddr1),

					src, ETH_ALEN);

			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);

		}

		break;

	case cpu_to_le16(0):
@@ -357,7 +369,7 @@ 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;

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