Commit 2d1c304c authored by Felix Fietkau's avatar Felix Fietkau Committed by Johannes Berg
Browse files

cfg80211: add function for 802.3 conversion with separate output buffer 



Use skb_copy_bits in preparation for allowing fragmented skbs

Signed-off-by: default avatarFelix Fietkau <nbd@openwrt.org>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 88665f5a

net/wireless/util.c

+53 −53
Original line number Diff line number Diff line
@@ -393,9 +393,9 @@ unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb) 
}

EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);



unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)

static unsigned int __ieee80211_get_mesh_hdrlen(u8 flags)

{

	int ae = meshhdr->flags & MESH_FLAGS_AE;

	int ae = flags & MESH_FLAGS_AE;

	/* 802.11-2012, 8.2.4.7.3 */

	switch (ae) {

	default:
@@ -407,21 +407,31 @@ unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr) 
		return 18;

	}

}



unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)

{

	return __ieee80211_get_mesh_hdrlen(meshhdr->flags);

}

EXPORT_SYMBOL(ieee80211_get_mesh_hdrlen);



int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,

			   enum nl80211_iftype iftype)

static int __ieee80211_data_to_8023(struct sk_buff *skb, struct ethhdr *ehdr,

				    const u8 *addr, enum nl80211_iftype iftype)

{

	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;

	u16 hdrlen, ethertype;

	u8 *payload;

	u8 dst[ETH_ALEN];

	u8 src[ETH_ALEN] __aligned(2);

	struct {

		u8 hdr[ETH_ALEN] __aligned(2);

		__be16 proto;

	} payload;

	struct ethhdr tmp;

	u16 hdrlen;

	u8 mesh_flags = 0;



	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))

		return -1;



	hdrlen = ieee80211_hdrlen(hdr->frame_control);

	if (skb->len < hdrlen + 8)

		return -1;



	/* convert IEEE 802.11 header + possible LLC headers into Ethernet

	 * header
@@ -432,8 +442,11 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr, 
	 *   1     0   BSSID SA    DA    n/a

	 *   1     1   RA    TA    DA    SA

	 */

	memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);

	memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);

	memcpy(tmp.h_dest, ieee80211_get_DA(hdr), ETH_ALEN);

	memcpy(tmp.h_source, ieee80211_get_SA(hdr), ETH_ALEN);



	if (iftype == NL80211_IFTYPE_MESH_POINT)

		skb_copy_bits(skb, hdrlen, &mesh_flags, 1);



	switch (hdr->frame_control &

		cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
@@ -450,44 +463,31 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr, 
			     iftype != NL80211_IFTYPE_STATION))

			return -1;

		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;

			if (meshdr->flags & MESH_FLAGS_AE_A4)

			if (mesh_flags & MESH_FLAGS_AE_A4)

				return -1;

			if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {

			if (mesh_flags & MESH_FLAGS_AE_A5_A6) {

				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);

					tmp.h_dest, 2 * ETH_ALEN);

			}

			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);

			hdrlen += __ieee80211_get_mesh_hdrlen(mesh_flags);

		}

		break;

	case cpu_to_le16(IEEE80211_FCTL_FROMDS):

		if ((iftype != NL80211_IFTYPE_STATION &&

		     iftype != NL80211_IFTYPE_P2P_CLIENT &&

		     iftype != NL80211_IFTYPE_MESH_POINT) ||

		    (is_multicast_ether_addr(dst) &&

		     ether_addr_equal(src, addr)))

		    (is_multicast_ether_addr(tmp.h_dest) &&

		     ether_addr_equal(tmp.h_source, addr)))

			return -1;

		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;

			if (meshdr->flags & MESH_FLAGS_AE_A5_A6)

			if (mesh_flags & MESH_FLAGS_AE_A5_A6)

				return -1;

			if (meshdr->flags & MESH_FLAGS_AE_A4)

			if (mesh_flags & MESH_FLAGS_AE_A4)

				skb_copy_bits(skb, hdrlen +

					offsetof(struct ieee80211s_hdr, eaddr1),

					src, ETH_ALEN);

			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);

					tmp.h_source, ETH_ALEN);

			hdrlen += __ieee80211_get_mesh_hdrlen(mesh_flags);

		}

		break;

	case cpu_to_le16(0):
@@ -498,33 +498,33 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr, 
		break;

	}



	if (!pskb_may_pull(skb, hdrlen + 8))

		return -1;



	payload = skb->data + hdrlen;

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

	skb_copy_bits(skb, hdrlen, &payload, sizeof(payload));

	tmp.h_proto = payload.proto;



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

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

		   ether_addr_equal(payload, bridge_tunnel_header))) {

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

		    tmp.h_proto != htons(ETH_P_AARP) &&

		    tmp.h_proto != htons(ETH_P_IPX)) ||

		   ether_addr_equal(payload.hdr, bridge_tunnel_header)))

		/* remove RFC1042 or Bridge-Tunnel encapsulation and

		 * replace EtherType */

		skb_pull(skb, hdrlen + 6);

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

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

	} else {

		struct ethhdr *ehdr;

		__be16 len;

		hdrlen += ETH_ALEN + 2;

	else

		tmp.h_proto = htons(skb->len);



	pskb_pull(skb, hdrlen);



		skb_pull(skb, hdrlen);

		len = htons(skb->len);

	if (!ehdr)

		ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));

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

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

		ehdr->h_proto = len;

	}

	memcpy(ehdr, &tmp, sizeof(tmp));



	return 0;

}



int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,

			   enum nl80211_iftype iftype)

{

	return __ieee80211_data_to_8023(skb, NULL, addr, iftype);

}

EXPORT_SYMBOL(ieee80211_data_to_8023);



int ieee80211_data_from_8023(struct sk_buff *skb, const u8 *addr,