Commit 17266ee9 authored by Edward Cree's avatar Edward Cree Committed by David S. Miller
Browse files

net: ipv4: listified version of ip_rcv 



Also involved adding a way to run a netfilter hook over a list of packets.
 Rather than attempting to make netfilter know about lists (which would be
 a major project in itself) we just let it call the regular okfn (in this
 case ip_rcv_finish()) for any packets it steals, and have it give us back
 a list of packets it's synchronously accepted (which normally NF_HOOK
 would automatically call okfn() on, but we want to be able to potentially
 pass the list to a listified version of okfn().)
The netfilter hooks themselves are indirect calls that still happen per-
 packet (see nf_hook_entry_hookfn()), but again, changing that can be left
 for future work.

There is potential for out-of-order receives if the netfilter hook ends up
 synchronously stealing packets, as they will be processed before any
 accepts earlier in the list.  However, it was already possible for an
 asynchronous accept to cause out-of-order receives, so presumably this is
 considered OK.

Signed-off-by: default avatarEdward Cree <ecree@solarflare.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 88eb1944

include/linux/netdevice.h

+3 −0
Original line number Diff line number Diff line
@@ -2297,6 +2297,9 @@ struct packet_type { 
					 struct net_device *,

					 struct packet_type *,

					 struct net_device *);

	void			(*list_func) (struct list_head *,

					      struct packet_type *,

					      struct net_device *);

	bool			(*id_match)(struct packet_type *ptype,

					    struct sock *sk);

	void			*af_packet_priv;

include/linux/netfilter.h

+22 −0
Original line number Diff line number Diff line
@@ -288,6 +288,20 @@ NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, struct 
	return ret;

}



static inline void

NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,

	     struct list_head *head, struct net_device *in, struct net_device *out,

	     int (*okfn)(struct net *, struct sock *, struct sk_buff *))

{

	struct sk_buff *skb, *next;



	list_for_each_entry_safe(skb, next, head, list) {

		int ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn);

		if (ret != 1)

			list_del(&skb->list);

	}

}



/* Call setsockopt() */

int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,

		  unsigned int len);
@@ -369,6 +383,14 @@ NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, 
	return okfn(net, sk, skb);

}



static inline void

NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,

	     struct list_head *head, struct net_device *in, struct net_device *out,

	     int (*okfn)(struct net *, struct sock *, struct sk_buff *))

{

	/* nothing to do */

}



static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,

			  struct sock *sk, struct sk_buff *skb,

			  struct net_device *indev, struct net_device *outdev,

include/net/ip.h

+2 −0
Original line number Diff line number Diff line
@@ -138,6 +138,8 @@ int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk, 
			  struct ip_options_rcu *opt);

int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,

	   struct net_device *orig_dev);

void ip_list_rcv(struct list_head *head, struct packet_type *pt,

		 struct net_device *orig_dev);

int ip_local_deliver(struct sk_buff *skb);

int ip_mr_input(struct sk_buff *skb);

int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);

net/core/dev.c

+5 −3
Original line number Diff line number Diff line
@@ -4806,7 +4806,9 @@ static inline void __netif_receive_skb_list_ptype(struct list_head *head, 
		return;

	if (list_empty(head))

		return;



	if (pt_prev->list_func != NULL)

		pt_prev->list_func(head, pt_prev, orig_dev);

	else

		list_for_each_entry_safe(skb, next, head, list)

			pt_prev->func(skb, skb->dev, pt_prev, orig_dev);

}

net/ipv4/af_inet.c

+1 −0
Original line number Diff line number Diff line
@@ -1882,6 +1882,7 @@ fs_initcall(ipv4_offload_init); 
static struct packet_type ip_packet_type __read_mostly = {

	.type = cpu_to_be16(ETH_P_IP),

	.func = ip_rcv,

	.list_func = ip_list_rcv,

};



static int __init inet_init(void)

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