Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit a8286911 authored by Johannes Berg's avatar Johannes Berg Committed by John W. Linville
Browse files

mac80211: linearize SKBs as needed for crypto 



Not linearizing every SKB will help actually pass
non-linear SKBs all the way up when on an encrypted
connection. For now, linearize TKIP completely as
it is lower performance and I don't quite grok all
the details.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 617bbde8

net/mac80211/rx.c

+2 −4
Original line number Diff line number Diff line
@@ -1063,10 +1063,6 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx) 
		return RX_DROP_MONITOR;

	}



	if (skb_linearize(rx->skb))

		return RX_DROP_UNUSABLE;

	/* the hdr variable is invalid now! */



	switch (rx->key->conf.cipher) {

	case WLAN_CIPHER_SUITE_WEP40:

	case WLAN_CIPHER_SUITE_WEP104:
@@ -1089,6 +1085,8 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx) 
		return RX_DROP_UNUSABLE;

	}



	/* the hdr variable is invalid after the decrypt handlers */



	/* either the frame has been decrypted or will be dropped */

	status->flag |= RX_FLAG_DECRYPTED;

net/mac80211/wep.c

+8 −3
Original line number Diff line number Diff line
@@ -284,22 +284,27 @@ ieee80211_crypto_wep_decrypt(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 (!ieee80211_is_data(hdr->frame_control) &&

	    !ieee80211_is_auth(hdr->frame_control))

	if (!ieee80211_is_data(fc) && !ieee80211_is_auth(fc))

		return RX_CONTINUE;



	if (!(status->flag & RX_FLAG_DECRYPTED)) {

		if (skb_linearize(rx->skb))

			return RX_DROP_UNUSABLE;

		if (rx->sta && ieee80211_wep_is_weak_iv(rx->skb, rx->key))

			rx->sta->wep_weak_iv_count++;

		if (ieee80211_wep_decrypt(rx->local, rx->skb, rx->key))

			return RX_DROP_UNUSABLE;

	} else if (!(status->flag & RX_FLAG_IV_STRIPPED)) {

		if (!pskb_may_pull(rx->skb, ieee80211_hdrlen(fc) + WEP_IV_LEN))

			return RX_DROP_UNUSABLE;

		if (rx->sta && ieee80211_wep_is_weak_iv(rx->skb, rx->key))

			rx->sta->wep_weak_iv_count++;

		ieee80211_wep_remove_iv(rx->local, rx->skb, rx->key);

		/* remove ICV */

		skb_trim(rx->skb, rx->skb->len - WEP_ICV_LEN);

		if (pskb_trim(rx->skb, rx->skb->len - WEP_ICV_LEN))

			return RX_DROP_UNUSABLE;

	}



	return RX_CONTINUE;

net/mac80211/wpa.c

+21 −1
Original line number Diff line number Diff line
@@ -138,6 +138,10 @@ ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx) 
	if (skb->len < hdrlen + MICHAEL_MIC_LEN)

		return RX_DROP_UNUSABLE;



	if (skb_linearize(rx->skb))

		return RX_DROP_UNUSABLE;

	hdr = (void *)skb->data;



	data = skb->data + hdrlen;

	data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;

	key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY];
@@ -253,6 +257,11 @@ ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx) 
	if (!rx->sta || skb->len - hdrlen < 12)

		return RX_DROP_UNUSABLE;



	/* it may be possible to optimize this a bit more */

	if (skb_linearize(rx->skb))

		return RX_DROP_UNUSABLE;

	hdr = (void *)skb->data;



	/*

	 * Let TKIP code verify IV, but skip decryption.

	 * In the case where hardware checks the IV as well,
@@ -484,6 +493,14 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx) 
	if (!rx->sta || data_len < 0)

		return RX_DROP_UNUSABLE;



	if (status->flag & RX_FLAG_DECRYPTED) {

		if (!pskb_may_pull(rx->skb, hdrlen + CCMP_HDR_LEN))

			return RX_DROP_UNUSABLE;

	} else {

		if (skb_linearize(rx->skb))

			return RX_DROP_UNUSABLE;

	}



	ccmp_hdr2pn(pn, skb->data + hdrlen);



	queue = rx->security_idx;
@@ -509,7 +526,8 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx) 
	memcpy(key->u.ccmp.rx_pn[queue], pn, CCMP_PN_LEN);



	/* Remove CCMP header and MIC */

	skb_trim(skb, skb->len - CCMP_MIC_LEN);

	if (pskb_trim(skb, skb->len - CCMP_MIC_LEN))

		return RX_DROP_UNUSABLE;

	memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);

	skb_pull(skb, CCMP_HDR_LEN);
@@ -609,6 +627,8 @@ ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx) 
	if (!ieee80211_is_mgmt(hdr->frame_control))

		return RX_CONTINUE;



	/* management frames are already linear */



	if (skb->len < 24 + sizeof(*mmie))

		return RX_DROP_UNUSABLE;