Commit bc416d97 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

macvlan: handle fragmented multicast frames 



Fragmented multicast frames are delivered to a single macvlan port,
because ip defrag logic considers other samples are redundant.

Implement a defrag step before trying to send the multicast frame.

Reported-by: default avatarBen Greear <greearb@candelatech.com>
Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f7ba35da

drivers/net/macvlan.c

+3 −0
Original line number Diff line number Diff line
@@ -169,6 +169,9 @@ static rx_handler_result_t macvlan_handle_frame(struct sk_buff **pskb) 


	port = macvlan_port_get_rcu(skb->dev);

	if (is_multicast_ether_addr(eth->h_dest)) {

		skb = ip_check_defrag(skb, IP_DEFRAG_MACVLAN);

		if (!skb)

			return RX_HANDLER_CONSUMED;

		src = macvlan_hash_lookup(port, eth->h_source);

		if (!src)

			/* frame comes from an external address */

include/net/ip.h

+9 −0
Original line number Diff line number Diff line
@@ -406,9 +406,18 @@ enum ip_defrag_users { 
	IP_DEFRAG_VS_OUT,

	IP_DEFRAG_VS_FWD,

	IP_DEFRAG_AF_PACKET,

	IP_DEFRAG_MACVLAN,

};



int ip_defrag(struct sk_buff *skb, u32 user);

#ifdef CONFIG_INET

struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user);

#else

static inline struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user)

{

	return skb;

}

#endif

int ip_frag_mem(struct net *net);

int ip_frag_nqueues(struct net *net);

net/ipv4/ip_fragment.c

+36 −0
Original line number Diff line number Diff line
@@ -682,6 +682,42 @@ int ip_defrag(struct sk_buff *skb, u32 user) 
}

EXPORT_SYMBOL(ip_defrag);



struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user)

{

	const struct iphdr *iph;

	u32 len;



	if (skb->protocol != htons(ETH_P_IP))

		return skb;



	if (!pskb_may_pull(skb, sizeof(struct iphdr)))

		return skb;



	iph = ip_hdr(skb);

	if (iph->ihl < 5 || iph->version != 4)

		return skb;

	if (!pskb_may_pull(skb, iph->ihl*4))

		return skb;

	iph = ip_hdr(skb);

	len = ntohs(iph->tot_len);

	if (skb->len < len || len < (iph->ihl * 4))

		return skb;



	if (ip_is_fragment(ip_hdr(skb))) {

		skb = skb_share_check(skb, GFP_ATOMIC);

		if (skb) {

			if (pskb_trim_rcsum(skb, len))

				return skb;

			memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));

			if (ip_defrag(skb, user))

				return NULL;

			skb->rxhash = 0;

		}

	}

	return skb;

}

EXPORT_SYMBOL(ip_check_defrag);



#ifdef CONFIG_SYSCTL

static int zero;

net/packet/af_packet.c

+1 −38
Original line number Diff line number Diff line
@@ -1213,43 +1213,6 @@ static struct sock *fanout_demux_cpu(struct packet_fanout *f, struct sk_buff *sk 
	return f->arr[cpu % num];

}



static struct sk_buff *fanout_check_defrag(struct sk_buff *skb)

{

#ifdef CONFIG_INET

	const struct iphdr *iph;

	u32 len;



	if (skb->protocol != htons(ETH_P_IP))

		return skb;



	if (!pskb_may_pull(skb, sizeof(struct iphdr)))

		return skb;



	iph = ip_hdr(skb);

	if (iph->ihl < 5 || iph->version != 4)

		return skb;

	if (!pskb_may_pull(skb, iph->ihl*4))

		return skb;

	iph = ip_hdr(skb);

	len = ntohs(iph->tot_len);

	if (skb->len < len || len < (iph->ihl * 4))

		return skb;



	if (ip_is_fragment(ip_hdr(skb))) {

		skb = skb_share_check(skb, GFP_ATOMIC);

		if (skb) {

			if (pskb_trim_rcsum(skb, len))

				return skb;

			memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));

			if (ip_defrag(skb, IP_DEFRAG_AF_PACKET))

				return NULL;

			skb->rxhash = 0;

		}

	}

#endif

	return skb;

}



static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,

			     struct packet_type *pt, struct net_device *orig_dev)

{
@@ -1268,7 +1231,7 @@ static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 
	case PACKET_FANOUT_HASH:

	default:

		if (f->defrag) {

			skb = fanout_check_defrag(skb);

			skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET);

			if (!skb)

				return 0;

		}