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

Commit 230fd28a authored by Felix Fietkau's avatar Felix Fietkau Committed by Johannes Berg
Browse files

cfg80211: add support for non-linear skbs in ieee80211_amsdu_to_8023s 



Signed-off-by: default avatarFelix Fietkau <nbd@openwrt.org>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 2d1c304c

net/wireless/util.c

+49 −51
Original line number Diff line number Diff line
@@ -644,73 +644,75 @@ int ieee80211_data_from_8023(struct sk_buff *skb, const u8 *addr, 
}

EXPORT_SYMBOL(ieee80211_data_from_8023);



static struct sk_buff *

__ieee80211_amsdu_copy(struct sk_buff *skb, unsigned int hlen,

		       int offset, int len)

{

	struct sk_buff *frame;



	if (skb->len - offset < len)

		return NULL;



	/*

	 * Allocate and reserve two bytes more for payload

	 * alignment since sizeof(struct ethhdr) is 14.

	 */

	frame = dev_alloc_skb(hlen + sizeof(struct ethhdr) + 2 + len);



	skb_reserve(frame, hlen + sizeof(struct ethhdr) + 2);

	skb_copy_bits(skb, offset, skb_put(frame, len), len);



	return frame;

}



void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list,

			      const u8 *addr, enum nl80211_iftype iftype,

			      const unsigned int extra_headroom,

			      bool has_80211_header)

{

	unsigned int hlen = ALIGN(extra_headroom, 4);

	struct sk_buff *frame = NULL;

	u16 ethertype;

	u8 *payload;

	const struct ethhdr *eth;

	int remaining, err;

	u8 dst[ETH_ALEN], src[ETH_ALEN];



	if (skb_linearize(skb))

		goto out;

	int offset = 0, remaining, err;

	struct ethhdr eth;

	bool reuse_skb = true;

	bool last = false;



	if (has_80211_header) {

		err = ieee80211_data_to_8023(skb, addr, iftype);

		err = __ieee80211_data_to_8023(skb, &eth, addr, iftype);

		if (err)

			goto out;



		/* skip the wrapping header */

		eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));

		if (!eth)

			goto out;

	} else {

		eth = (struct ethhdr *) skb->data;

	}



	while (skb != frame) {

	while (!last) {

		unsigned int subframe_len;

		int len;

		u8 padding;

		__be16 len = eth->h_proto;

		unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);



		remaining = skb->len;

		memcpy(dst, eth->h_dest, ETH_ALEN);

		memcpy(src, eth->h_source, ETH_ALEN);



		skb_copy_bits(skb, offset, &eth, sizeof(eth));

		len = ntohs(eth.h_proto);

		subframe_len = sizeof(struct ethhdr) + len;

		padding = (4 - subframe_len) & 0x3;



		/* the last MSDU has no padding */

		remaining = skb->len - offset;

		if (subframe_len > remaining)

			goto purge;



		skb_pull(skb, sizeof(struct ethhdr));

		offset += sizeof(struct ethhdr);

		/* reuse skb for the last subframe */

		if (remaining <= subframe_len + padding)

		last = remaining <= subframe_len + padding;

		if (!skb_is_nonlinear(skb) && last) {

			skb_pull(skb, offset);

			frame = skb;

		else {

			unsigned int hlen = ALIGN(extra_headroom, 4);

			/*

			 * Allocate and reserve two bytes more for payload

			 * alignment since sizeof(struct ethhdr) is 14.

			 */

			frame = dev_alloc_skb(hlen + subframe_len + 2);

			reuse_skb = true;

		} else {

			frame = __ieee80211_amsdu_copy(skb, hlen, offset, len);

			if (!frame)

				goto purge;



			skb_reserve(frame, hlen + sizeof(struct ethhdr) + 2);

			memcpy(skb_put(frame, ntohs(len)), skb->data,

				ntohs(len));



			eth = (struct ethhdr *)skb_pull(skb, ntohs(len) +

							padding);

			if (!eth) {

				dev_kfree_skb(frame);

				goto purge;

			}

			offset += len + padding;

		}



		skb_reset_network_header(frame);
@@ -719,24 +721,20 @@ void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list, 


		payload = frame->data;

		ethertype = (payload[6] << 8) | payload[7];



		if (likely((ether_addr_equal(payload, rfc1042_header) &&

			    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||

			   ether_addr_equal(payload, bridge_tunnel_header))) {

			/* remove RFC1042 or Bridge-Tunnel

			 * encapsulation and replace EtherType */

			skb_pull(frame, 6);

			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);

			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);

		} else {

			memcpy(skb_push(frame, sizeof(__be16)), &len,

				sizeof(__be16));

			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);

			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);

			eth.h_proto = htons(ethertype);

			skb_pull(frame, ETH_ALEN + 2);

		}



		memcpy(skb_push(frame, sizeof(eth)), &eth, sizeof(eth));

		__skb_queue_tail(list, frame);

	}



	if (!reuse_skb)

		dev_kfree_skb(skb);



	return;



 purge: