Commit 838b83d6 authored by Alexander Aring's avatar Alexander Aring Committed by Marcel Holtmann
Browse files

ieee802154: introduce wpan_dev_header_ops 



The current header_ops callback structure of net device are used mostly
from 802.15.4 upper-layers. Because this callback structure is a very
generic one, which is also used by e.g. DGRAM AF_PACKET sockets, we
can't make this callback structure 802.15.4 specific which is currently
is.

I saw the smallest "constraint" for calling this callback with
dev_hard_header/dev_parse_header by AF_PACKET which assign a 8 byte
array for address void pointers. Currently 802.15.4 specific protocols
like af802154 and 6LoWPAN will assign the "struct ieee802154_addr" as
these parameters which is greater than 8 bytes. The current callback
implementation for header_ops.create assumes always a complete
"struct ieee802154_addr" which AF_PACKET can't never handled and is
greater than 8 bytes.

For that reason we introduce now a "generic" create/parse header_ops
callback which allows handling with intra-pan extended addresses only.
This allows a small use-case with AF_PACKET to send "somehow" a valid
dataframe over DGRAM.

To keeping the current dev_hard_header behaviour we introduce a similar
callback structure "wpan_dev_header_ops" which contains 802.15.4 specific
upper-layer header creation functionality, which can be called by
wpan_dev_hard_header.

Signed-off-by: default avatarAlexander Aring <alex.aring@gmail.com>
Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
parent a1da67b8

include/net/cfg802154.h

+33 −0
Original line number Diff line number Diff line
@@ -167,6 +167,26 @@ struct wpan_phy { 
	char priv[0] __aligned(NETDEV_ALIGN);

};



struct ieee802154_addr {

	u8 mode;

	__le16 pan_id;

	union {

		__le16 short_addr;

		__le64 extended_addr;

	};

};



struct wpan_dev_header_ops {

	/* TODO create callback currently assumes ieee802154_mac_cb inside

	 * skb->cb. This should be changed to give these information as

	 * parameter.

	 */

	int	(*create)(struct sk_buff *skb, struct net_device *dev,

			  const struct ieee802154_addr *daddr,

			  const struct ieee802154_addr *saddr,

			  unsigned int len);

};



struct wpan_dev {

	struct wpan_phy *wpan_phy;

	int iftype;
@@ -175,6 +195,8 @@ struct wpan_dev { 
	struct list_head list;

	struct net_device *netdev;



	const struct wpan_dev_header_ops *header_ops;



	/* lowpan interface, set when the wpan_dev belongs to one lowpan_dev */

	struct net_device *lowpan_dev;
@@ -205,6 +227,17 @@ struct wpan_dev { 


#define to_phy(_dev)	container_of(_dev, struct wpan_phy, dev)



static inline int

wpan_dev_hard_header(struct sk_buff *skb, struct net_device *dev,

		     const struct ieee802154_addr *daddr,

		     const struct ieee802154_addr *saddr,

		     unsigned int len)

{

	struct wpan_dev *wpan_dev = dev->ieee802154_ptr;



	return wpan_dev->header_ops->create(skb, dev, daddr, saddr, len);

}



struct wpan_phy *

wpan_phy_new(const struct cfg802154_ops *ops, size_t priv_size);

static inline void wpan_phy_set_dev(struct wpan_phy *phy, struct device *dev)

include/net/ieee802154_netdev.h

+0 −9
Original line number Diff line number Diff line
@@ -50,15 +50,6 @@ struct ieee802154_sechdr { 
	};

};



struct ieee802154_addr {

	u8 mode;

	__le16 pan_id;

	union {

		__le16 short_addr;

		__le64 extended_addr;

	};

};



struct ieee802154_hdr_fc {

#if defined(__LITTLE_ENDIAN_BITFIELD)

	u16 type:3,

net/ieee802154/6lowpan/tx.c

+4 −4
Original line number Diff line number Diff line
@@ -87,7 +87,7 @@ lowpan_alloc_frag(struct sk_buff *skb, int size, 
		skb_reset_network_header(frag);

		*mac_cb(frag) = *mac_cb(skb);



		rc = dev_hard_header(frag, wdev, 0, &master_hdr->dest,

		rc = wpan_dev_hard_header(frag, wdev, &master_hdr->dest,

					  &master_hdr->source, size);

		if (rc < 0) {

			kfree_skb(frag);
@@ -228,8 +228,8 @@ static int lowpan_header(struct sk_buff *skb, struct net_device *ldev, 
		cb->ackreq = wpan_dev->ackreq;

	}



	return dev_hard_header(skb, lowpan_dev_info(ldev)->wdev, ETH_P_IPV6,

			       (void *)&da, (void *)&sa, 0);

	return wpan_dev_hard_header(skb, lowpan_dev_info(ldev)->wdev, &da, &sa,

				    0);

}



netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *ldev)

net/ieee802154/socket.c

+2 −2
Original line number Diff line number Diff line
@@ -676,7 +676,7 @@ static int dgram_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) 
	cb->seclevel = ro->seclevel;

	cb->seclevel_override = ro->seclevel_override;



	err = dev_hard_header(skb, dev, ETH_P_IEEE802154, &dst_addr,

	err = wpan_dev_hard_header(skb, dev, &dst_addr,

				   ro->bound ? &ro->src_addr : NULL, size);

	if (err < 0)

		goto out_skb;

net/mac802154/iface.c

+79 −12
Original line number Diff line number Diff line
@@ -367,11 +367,10 @@ static int mac802154_set_header_security(struct ieee802154_sub_if_data *sdata, 
	return 0;

}



static int mac802154_header_create(struct sk_buff *skb,

static int ieee802154_header_create(struct sk_buff *skb,

				    struct net_device *dev,

				   unsigned short type,

				   const void *daddr,

				   const void *saddr,

				    const struct ieee802154_addr *daddr,

				    const struct ieee802154_addr *saddr,

				    unsigned len)

{

	struct ieee802154_hdr hdr;
@@ -423,22 +422,89 @@ static int mac802154_header_create(struct sk_buff *skb, 
	return hlen;

}



static const struct wpan_dev_header_ops ieee802154_header_ops = {

	.create		= ieee802154_header_create,

};



/* This header create functionality assumes a 8 byte array for

 * source and destination pointer at maximum. To adapt this for

 * the 802.15.4 dataframe header we use extended address handling

 * here only and intra pan connection. fc fields are mostly fallback

 * handling. For provide dev_hard_header for dgram sockets.

 */

static int mac802154_header_create(struct sk_buff *skb,

				   struct net_device *dev,

				   unsigned short type,

				   const void *daddr,

				   const void *saddr,

				   unsigned len)

{

	struct ieee802154_hdr hdr;

	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);

	struct wpan_dev *wpan_dev = &sdata->wpan_dev;

	struct ieee802154_mac_cb cb = { };

	int hlen;



	if (!daddr)

		return -EINVAL;



	memset(&hdr.fc, 0, sizeof(hdr.fc));

	hdr.fc.type = IEEE802154_FC_TYPE_DATA;

	hdr.fc.ack_request = wpan_dev->ackreq;

	hdr.seq = atomic_inc_return(&dev->ieee802154_ptr->dsn) & 0xFF;



	/* TODO currently a workaround to give zero cb block to set

	 * security parameters defaults according MIB.

	 */

	if (mac802154_set_header_security(sdata, &hdr, &cb) < 0)

		return -EINVAL;



	hdr.dest.pan_id = wpan_dev->pan_id;

	hdr.dest.mode = IEEE802154_ADDR_LONG;

	memcpy(&hdr.dest.extended_addr, daddr, IEEE802154_EXTENDED_ADDR_LEN);



	hdr.source.pan_id = hdr.dest.pan_id;

	hdr.source.mode = IEEE802154_ADDR_LONG;



	if (!saddr)

		hdr.source.extended_addr = wpan_dev->extended_addr;

	else

		memcpy(&hdr.source.extended_addr, saddr,

		       IEEE802154_EXTENDED_ADDR_LEN);



	hlen = ieee802154_hdr_push(skb, &hdr);

	if (hlen < 0)

		return -EINVAL;



	skb_reset_mac_header(skb);

	skb->mac_len = hlen;



	if (len > ieee802154_max_payload(&hdr))

		return -EMSGSIZE;



	return hlen;

}



static int

mac802154_header_parse(const struct sk_buff *skb, unsigned char *haddr)

{

	struct ieee802154_hdr hdr;

	struct ieee802154_addr *addr = (struct ieee802154_addr *)haddr;



	if (ieee802154_hdr_peek_addrs(skb, &hdr) < 0) {

		pr_debug("malformed packet\n");

		return 0;

	}



	*addr = hdr.source;

	return sizeof(*addr);

	if (hdr.source.mode == IEEE802154_ADDR_LONG) {

		memcpy(haddr, &hdr.source.extended_addr,

		       IEEE802154_EXTENDED_ADDR_LEN);

		return IEEE802154_EXTENDED_ADDR_LEN;

	}



	return 0;

}



static struct header_ops mac802154_header_ops = {

static const struct header_ops mac802154_header_ops = {

	.create         = mac802154_header_create,

	.parse          = mac802154_header_parse,

};
@@ -513,6 +579,7 @@ ieee802154_setup_sdata(struct ieee802154_sub_if_data *sdata, 
		sdata->dev->netdev_ops = &mac802154_wpan_ops;

		sdata->dev->ml_priv = &mac802154_mlme_wpan;

		wpan_dev->promiscuous_mode = false;

		wpan_dev->header_ops = &ieee802154_header_ops;



		mutex_init(&sdata->sec_mtx);

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