Commit 28d35ad0 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge tag 'batadv-net-pullrequest-20201127' of git://git.open-mesh.org/linux-merge 

Simon Wunderlich says:

====================
Here are some batman-adv bugfixes:

 - Fix head/tailroom issues for fragments, by Sven Eckelmann (3 patches)

* tag 'batadv-net-pullrequest-20201127' of git://git.open-mesh.org/linux-merge:
  batman-adv: Don't always reallocate the fragmentation skb head
  batman-adv: Reserve needed_*room for fragments
  batman-adv: Consider fragmentation for needed_headroom
====================

Link: https://lore.kernel.org/r/20201127173849.19208-1-sw@simonwunderlich.de


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 44f64f23 992b03b8

net/batman-adv/fragmentation.c

+16 −10
Original line number Diff line number Diff line
@@ -391,6 +391,7 @@ bool batadv_frag_skb_fwd(struct sk_buff *skb, 


/**

 * batadv_frag_create() - create a fragment from skb

 * @net_dev: outgoing device for fragment

 * @skb: skb to create fragment from

 * @frag_head: header to use in new fragment

 * @fragment_size: size of new fragment
@@ -401,22 +402,25 @@ bool batadv_frag_skb_fwd(struct sk_buff *skb, 
 *

 * Return: the new fragment, NULL on error.

 */

static struct sk_buff *batadv_frag_create(struct sk_buff *skb,

static struct sk_buff *batadv_frag_create(struct net_device *net_dev,

					  struct sk_buff *skb,

					  struct batadv_frag_packet *frag_head,

					  unsigned int fragment_size)

{

	unsigned int ll_reserved = LL_RESERVED_SPACE(net_dev);

	unsigned int tailroom = net_dev->needed_tailroom;

	struct sk_buff *skb_fragment;

	unsigned int header_size = sizeof(*frag_head);

	unsigned int mtu = fragment_size + header_size;



	skb_fragment = netdev_alloc_skb(NULL, mtu + ETH_HLEN);

	skb_fragment = dev_alloc_skb(ll_reserved + mtu + tailroom);

	if (!skb_fragment)

		goto err;



	skb_fragment->priority = skb->priority;



	/* Eat the last mtu-bytes of the skb */

	skb_reserve(skb_fragment, header_size + ETH_HLEN);

	skb_reserve(skb_fragment, ll_reserved + header_size);

	skb_split(skb, skb_fragment, skb->len - fragment_size);



	/* Add the header */
@@ -439,11 +443,12 @@ int batadv_frag_send_packet(struct sk_buff *skb, 
			    struct batadv_orig_node *orig_node,

			    struct batadv_neigh_node *neigh_node)

{

	struct net_device *net_dev = neigh_node->if_incoming->net_dev;

	struct batadv_priv *bat_priv;

	struct batadv_hard_iface *primary_if = NULL;

	struct batadv_frag_packet frag_header;

	struct sk_buff *skb_fragment;

	unsigned int mtu = neigh_node->if_incoming->net_dev->mtu;

	unsigned int mtu = net_dev->mtu;

	unsigned int header_size = sizeof(frag_header);

	unsigned int max_fragment_size, num_fragments;

	int ret;
@@ -503,7 +508,7 @@ int batadv_frag_send_packet(struct sk_buff *skb, 
			goto put_primary_if;

		}



		skb_fragment = batadv_frag_create(skb, &frag_header,

		skb_fragment = batadv_frag_create(net_dev, skb, &frag_header,

						  max_fragment_size);

		if (!skb_fragment) {

			ret = -ENOMEM;
@@ -522,13 +527,14 @@ int batadv_frag_send_packet(struct sk_buff *skb, 
		frag_header.no++;

	}



	/* Make room for the fragment header. */

	if (batadv_skb_head_push(skb, header_size) < 0 ||

	    pskb_expand_head(skb, header_size + ETH_HLEN, 0, GFP_ATOMIC) < 0) {

		ret = -ENOMEM;

	/* make sure that there is at least enough head for the fragmentation

	 * and ethernet headers

	 */

	ret = skb_cow_head(skb, ETH_HLEN + header_size);

	if (ret < 0)

		goto put_primary_if;

	}



	skb_push(skb, header_size);

	memcpy(skb->data, &frag_header, header_size);



	/* Send the last fragment */

net/batman-adv/hard-interface.c

+3 −0
Original line number Diff line number Diff line
@@ -554,6 +554,9 @@ static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface) 
	needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);

	needed_headroom += batadv_max_header_len();



	/* fragmentation headers don't strip the unicast/... header */

	needed_headroom += sizeof(struct batadv_frag_packet);



	soft_iface->needed_headroom = needed_headroom;

	soft_iface->needed_tailroom = lower_tailroom;

}