Commit 57e1ab6e authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

igmp: refine skb allocations 



IGMP allocates MTU sized skbs. This may fail for large MTU (order-2
allocations), so add a fallback to try lower sizes.

Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4c3710af

net/ipv4/igmp.c

+13 −4
Original line number Diff line number Diff line
@@ -300,6 +300,8 @@ igmp_scount(struct ip_mc_list *pmc, int type, int gdeleted, int sdeleted) 
	return scount;

}



#define igmp_skb_size(skb) (*(unsigned int *)((skb)->cb))



static struct sk_buff *igmpv3_newpack(struct net_device *dev, int size)

{

	struct sk_buff *skb;
@@ -308,9 +310,16 @@ static struct sk_buff *igmpv3_newpack(struct net_device *dev, int size) 
	struct igmpv3_report *pig;

	struct net *net = dev_net(dev);



	skb = alloc_skb(size + LL_ALLOCATED_SPACE(dev), GFP_ATOMIC);

	if (skb == NULL)

	while (1) {

		skb = alloc_skb(size + LL_ALLOCATED_SPACE(dev),

				GFP_ATOMIC | __GFP_NOWARN);

		if (skb)

			break;

		size >>= 1;

		if (size < 256)

			return NULL;

	}

	igmp_skb_size(skb) = size;



	{

		struct flowi fl = { .oif = dev->ifindex,
@@ -399,7 +408,7 @@ static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc, 
	return skb;

}



#define AVAILABLE(skb) ((skb) ? ((skb)->dev ? (skb)->dev->mtu - (skb)->len : \

#define AVAILABLE(skb) ((skb) ? ((skb)->dev ? igmp_skb_size(skb) - (skb)->len : \

	skb_tailroom(skb)) : 0)



static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc,