xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

netfilter: Pass struct net into the netfilter hooks

Browse Source 
Pass a network namespace parameter into the netfilter hooks.  At the
call site of the netfilter hooks the path a packet is taking through
the network stack is well known which allows the network namespace to
be easily and reliabily.

This allows the replacement of magic code like
"dev_net(state->in?:state->out)" that appears at the start of most
netfilter hooks with "state->net".

In almost all cases the network namespace passed in is derived
from the first network device passed in, guaranteeing those
paths will not see any changes in practice.

The exceptions are:
xfrm/xfrm_output.c:xfrm_output_resume()         xs_net(skb_dst(skb)->xfrm)
ipvs/ip_vs_xmit.c:ip_vs_nat_send_or_cont()      ip_vs_conn_net(cp)
ipvs/ip_vs_xmit.c:ip_vs_send_or_cont()          ip_vs_conn_net(cp)
ipv4/raw.c:raw_send_hdrinc()                    sock_net(sk)
ipv6/ip6_output.c:ip6_xmit()			sock_net(sk)
ipv6/ndisc.c:ndisc_send_skb()                   dev_net(skb->dev) not dev_net(dst->dev)
ipv6/raw.c:raw6_send_hdrinc()                   sock_net(sk)
br_netfilter_hooks.c:br_nf_pre_routing_finish() dev_net(skb->dev) before skb->dev is set to nf_bridge->physindev

In all cases these exceptions seem to be a better expression for the
network namespace the packet is being processed in then the historic
"dev_net(in?in:out)".  I am documenting them in case something odd
pops up and someone starts trying to track down what happened.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric W. Biederman
2015-09-15 20:04:16 -05:00
committed by David S. Miller
parent 04eb44890e
commit 29a26a5680
31 changed files with 142 additions and 120 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
net/ipv4/arp.c
View File

@@ -632,8 +632,9 @@ static int arp_xmit_finish(struct sock *sk, struct sk_buff *skb)
void arp_xmit(struct sk_buff *skb)
{
/* Send it off, maybe filter it using firewalling first. */
NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, NULL, skb,
NULL, skb->dev, arp_xmit_finish);
NF_HOOK(NFPROTO_ARP, NF_ARP_OUT,
dev_net(skb->dev), NULL, skb, NULL, skb->dev,
arp_xmit_finish);
}
EXPORT_SYMBOL(arp_xmit);
@@ -897,8 +898,9 @@ static int arp_rcv(struct sk_buff *skb, struct net_device *dev,
memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, NULL, skb,
dev, NULL, arp_process);
return NF_HOOK(NFPROTO_ARP, NF_ARP_IN,
dev_net(dev), NULL, skb, dev, NULL,
arp_process);
consumeskb:
consume_skb(skb);