net: ipv4: listify ip_rcv_finish

ip_rcv_finish_core(), if it does not drop, sets skb->dst by either early
 demux or route lookup.  The last step, calling dst_input(skb), is left to
 the caller; in the listified case, we split to form sublists with a common
 dst, but then ip_sublist_rcv_finish() just calls dst_input(skb) in a loop.
The next step in listification would thus be to add a list_input() method
 to struct dst_entry.

Early demux is an indirect call based on iph->protocol; this is another
 opportunity for listification which is not taken here (it would require
 slicing up ip_rcv_finish_core() to allow splitting on protocol changes).

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Edward Cree 2018-07-02 16:14:34 +01:00 committed by David S. Miller
parent 17266ee939
commit 5fa12739a5
1 changed files with 48 additions and 6 deletions

View File

@ -307,7 +307,8 @@ static inline bool ip_rcv_options(struct sk_buff *skb)
return true;
}
static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
static int ip_rcv_finish_core(struct net *net, struct sock *sk,
struct sk_buff *skb)
{
const struct iphdr *iph = ip_hdr(skb);
int (*edemux)(struct sk_buff *skb);
@ -393,7 +394,7 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
goto drop;
}
return dst_input(skb);
return NET_RX_SUCCESS;
drop:
kfree_skb(skb);
@ -405,6 +406,15 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
goto drop;
}
static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
{
int ret = ip_rcv_finish_core(net, sk, skb);
if (ret != NET_RX_DROP)
ret = dst_input(skb);
return ret;
}
/*
* Main IP Receive routine.
*/
@ -515,15 +525,47 @@ int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
ip_rcv_finish);
}
static void ip_sublist_rcv(struct list_head *head, struct net_device *dev,
struct net *net)
static void ip_sublist_rcv_finish(struct list_head *head)
{
struct sk_buff *skb, *next;
list_for_each_entry_safe(skb, next, head, list)
dst_input(skb);
}
static void ip_list_rcv_finish(struct net *net, struct sock *sk,
struct list_head *head)
{
struct dst_entry *curr_dst = NULL;
struct sk_buff *skb, *next;
struct list_head sublist;
list_for_each_entry_safe(skb, next, head, list) {
struct dst_entry *dst;
if (ip_rcv_finish_core(net, sk, skb) == NET_RX_DROP)
continue;
dst = skb_dst(skb);
if (curr_dst != dst) {
/* dispatch old sublist */
list_cut_before(&sublist, head, &skb->list);
if (!list_empty(&sublist))
ip_sublist_rcv_finish(&sublist);
/* start new sublist */
curr_dst = dst;
}
}
/* dispatch final sublist */
ip_sublist_rcv_finish(head);
}
static void ip_sublist_rcv(struct list_head *head, struct net_device *dev,
struct net *net)
{
NF_HOOK_LIST(NFPROTO_IPV4, NF_INET_PRE_ROUTING, net, NULL,
head, dev, NULL, ip_rcv_finish);
list_for_each_entry_safe(skb, next, head, list)
ip_rcv_finish(net, NULL, skb);
ip_list_rcv_finish(net, NULL, head);
}
/* Receive a list of IP packets */