From 29a26a56803855a79dbd028cd61abee56237d6e5 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 15 Sep 2015 20:04:16 -0500 Subject: netfilter: Pass struct net into the netfilter hooks 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" Signed-off-by: David S. Miller --- net/ipv4/arp.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'net/ipv4/arp.c') diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c index 3632e98eb0f9..ae71e9ade5f9 100644 --- a/net/ipv4/arp.c +++ b/net/ipv4/arp.c @@ -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); -- cgit v1.2.3