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Commit aedbffc7 authored by Sven Eckelmann's avatar Sven Eckelmann Committed by Greg Kroah-Hartman
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Staging: batman-adv: Create copy of skb with pre-allocated headroom 



We can use skb_cow instead of a handwritten function to test and create
a writable skb buffer. This also allows us to pre-allocate headroom to
be able to send the data without re-allocating the buffer again to add
the ethernet header.

Signed-off-by: default avatarSven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent b411d498

drivers/staging/batman-adv/routing.c

+24 −53
Original line number Diff line number Diff line
@@ -742,7 +742,6 @@ int recv_bat_packet(struct sk_buff *skb, 
{

	struct ethhdr *ethhdr;

	unsigned long flags;

	struct sk_buff *skb_old;



	/* drop packet if it has not necessary minimum size */

	if (skb_headlen(skb) < sizeof(struct batman_packet))
@@ -758,18 +757,11 @@ int recv_bat_packet(struct sk_buff *skb, 
	if (is_bcast(ethhdr->h_source))

		return NET_RX_DROP;



	/* TODO: we use headlen instead of "length", because

	 * only this data is paged in. */



	/* create a copy of the skb, if needed, to modify it. */

	if (!skb_clone_writable(skb, skb_headlen(skb))) {

		skb_old = skb;

		skb = skb_copy(skb, GFP_ATOMIC);

		if (!skb)

	if (skb_cow(skb, 0) < 0)

		return NET_RX_DROP;



	ethhdr = (struct ethhdr *)skb_mac_header(skb);

		kfree_skb(skb_old);

	}



	spin_lock_irqsave(&orig_hash_lock, flags);

	receive_aggr_bat_packet(ethhdr,
@@ -789,7 +781,6 @@ static int recv_my_icmp_packet(struct sk_buff *skb, size_t icmp_len) 
	struct orig_node *orig_node;

	struct icmp_packet_rr *icmp_packet;

	struct ethhdr *ethhdr;

	struct sk_buff *skb_old;

	struct batman_if *batman_if;

	int ret;

	unsigned long flags;
@@ -824,16 +815,11 @@ static int recv_my_icmp_packet(struct sk_buff *skb, size_t icmp_len) 
		spin_unlock_irqrestore(&orig_hash_lock, flags);



		/* create a copy of the skb, if needed, to modify it. */

		skb_old = NULL;

		if (!skb_clone_writable(skb, icmp_len)) {

			skb_old = skb;

			skb = skb_copy(skb, GFP_ATOMIC);

			if (!skb)

		if (skb_cow(skb, sizeof(struct ethhdr)) < 0)

			return NET_RX_DROP;



		icmp_packet = (struct icmp_packet_rr *)skb->data;

		ethhdr = (struct ethhdr *)skb_mac_header(skb);

			kfree_skb(skb_old);

		}



		memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);

		memcpy(icmp_packet->orig,
@@ -857,7 +843,6 @@ static int recv_icmp_ttl_exceeded(struct sk_buff *skb, size_t icmp_len) 
	struct orig_node *orig_node;

	struct icmp_packet *icmp_packet;

	struct ethhdr *ethhdr;

	struct sk_buff *skb_old;

	struct batman_if *batman_if;

	int ret;

	unsigned long flags;
@@ -893,15 +878,11 @@ static int recv_icmp_ttl_exceeded(struct sk_buff *skb, size_t icmp_len) 
		spin_unlock_irqrestore(&orig_hash_lock, flags);



		/* create a copy of the skb, if needed, to modify it. */

		if (!skb_clone_writable(skb, icmp_len)) {

			skb_old = skb;

			skb = skb_copy(skb, GFP_ATOMIC);

			if (!skb)

		if (skb_cow(skb, sizeof(struct ethhdr)) < 0)

			return NET_RX_DROP;



		icmp_packet = (struct icmp_packet *) skb->data;

		ethhdr = (struct ethhdr *)skb_mac_header(skb);

			kfree_skb(skb_old);

		}



		memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);

		memcpy(icmp_packet->orig,
@@ -924,7 +905,6 @@ int recv_icmp_packet(struct sk_buff *skb) 
	struct icmp_packet_rr *icmp_packet;

	struct ethhdr *ethhdr;

	struct orig_node *orig_node;

	struct sk_buff *skb_old;

	struct batman_if *batman_if;

	int hdr_size = sizeof(struct icmp_packet);

	int ret;
@@ -990,15 +970,11 @@ int recv_icmp_packet(struct sk_buff *skb) 
		spin_unlock_irqrestore(&orig_hash_lock, flags);



		/* create a copy of the skb, if needed, to modify it. */

		if (!skb_clone_writable(skb, hdr_size)) {

			skb_old = skb;

			skb = skb_copy(skb, GFP_ATOMIC);

			if (!skb)

		if (skb_cow(skb, sizeof(struct ethhdr)) < 0)

			return NET_RX_DROP;



		icmp_packet = (struct icmp_packet_rr *)skb->data;

		ethhdr = (struct ethhdr *)skb_mac_header(skb);

			kfree_skb(skb_old);

		}



		/* decrement ttl */

		icmp_packet->ttl--;
@@ -1137,7 +1113,6 @@ static int route_unicast_packet(struct sk_buff *skb, struct batman_if *recv_if, 
	struct orig_node *orig_node;

	struct neigh_node *router;

	struct batman_if *batman_if;

	struct sk_buff *skb_old;

	uint8_t dstaddr[ETH_ALEN];

	unsigned long flags;

	struct unicast_packet *unicast_packet =
@@ -1173,15 +1148,11 @@ static int route_unicast_packet(struct sk_buff *skb, struct batman_if *recv_if, 
	spin_unlock_irqrestore(&orig_hash_lock, flags);



	/* create a copy of the skb, if needed, to modify it. */

	if (!skb_clone_writable(skb, hdr_size)) {

		skb_old = skb;

		skb = skb_copy(skb, GFP_ATOMIC);

		if (!skb)

	if (skb_cow(skb, sizeof(struct ethhdr)) < 0)

		return NET_RX_DROP;



	unicast_packet = (struct unicast_packet *) skb->data;

	ethhdr = (struct ethhdr *)skb_mac_header(skb);

		kfree_skb(skb_old);

	}



	/* decrement ttl */

	unicast_packet->ttl--;