Merge branch 'pass_net_through_output_path'

Eric W. Biederman says:

====================
net: Pass net through the output path v2

This is the next installment of my work to pass struct net through the
output path so the code does not need to guess how to figure out which
network namespace it is in, and ultimately routes can have output
devices in another network namespace.

The first patch in this series is a fix for a bug that came in when sk
was passed through the functions in the output path, and as such is
probably a candidate for net.  At the same time my later patches depend
on it so sending the fix separately would be confusing.

The second patch in this series is another fix that for an issue that
came in when sk was passed through the output path.  I don't think it
needs a backport as I don't think anyone uses the path where the code
was incorrect.

The rest of the patchset focuses on the path from xxx_local_out to
dst_output and in the end succeeds in passing sock_net(sk) from the
socket a packet locally originates on to the dst->output function.

Given the size reduction in the code I think this counts as a cleanup as
much as feature work.

There remain a number of helper functions (like ip option processing) to
take care of before the network stack can support destination devices in
other network namespaces but with this set of changes the backbone of
the work is done.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 14 insertions, 12 deletions

diff --git a/drivers/net/ipvlan/ipvlan_core.c b/drivers/net/ipvlan/ipvlan_core.c
index 207f62e8de9a..24f8dbcf854f 100644
--- a/drivers/net/ipvlan/ipvlan_core.c
+++ b/drivers/net/ipvlan/ipvlan_core.c
@@ -344,6 +344,7 @@ static int ipvlan_process_v4_outbound(struct sk_buff *skb)
 {
 	const struct iphdr *ip4h = ip_hdr(skb);
 	struct net_device *dev = skb->dev;
+	struct net *net = dev_net(dev);
 	struct rtable *rt;
 	int err, ret = NET_XMIT_DROP;
 	struct flowi4 fl4 = {
@@ -354,7 +355,7 @@ static int ipvlan_process_v4_outbound(struct sk_buff *skb)
 		.saddr = ip4h->saddr,
 	};
 
-	rt = ip_route_output_flow(dev_net(dev), &fl4, NULL);
+	rt = ip_route_output_flow(net, &fl4, NULL);
 	if (IS_ERR(rt))
 		goto err;
 
@@ -364,7 +365,7 @@ static int ipvlan_process_v4_outbound(struct sk_buff *skb)
 	}
 	skb_dst_drop(skb);
 	skb_dst_set(skb, &rt->dst);
-	err = ip_local_out(skb);
+	err = ip_local_out(net, skb->sk, skb);
 	if (unlikely(net_xmit_eval(err)))
 		dev->stats.tx_errors++;
 	else
@@ -381,6 +382,7 @@ static int ipvlan_process_v6_outbound(struct sk_buff *skb)
 {
 	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 	struct net_device *dev = skb->dev;
+	struct net *net = dev_net(dev);
 	struct dst_entry *dst;
 	int err, ret = NET_XMIT_DROP;
 	struct flowi6 fl6 = {
@@ -393,7 +395,7 @@ static int ipvlan_process_v6_outbound(struct sk_buff *skb)
 		.flowi6_proto = ip6h->nexthdr,
 	};
 
-	dst = ip6_route_output(dev_net(dev), NULL, &fl6);
+	dst = ip6_route_output(net, NULL, &fl6);
 	if (dst->error) {
 		ret = dst->error;
 		dst_release(dst);
@@ -401,7 +403,7 @@ static int ipvlan_process_v6_outbound(struct sk_buff *skb)
 	}
 	skb_dst_drop(skb);
 	skb_dst_set(skb, dst);
-	err = ip6_local_out(skb);
+	err = ip6_local_out(net, skb->sk, skb);
 	if (unlikely(net_xmit_eval(err)))
 		dev->stats.tx_errors++;
 	else
diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c
index 686f37daa262..fc69e41d0950 100644
--- a/drivers/net/ppp/pptp.c
+++ b/drivers/net/ppp/pptp.c
@@ -169,6 +169,7 @@ static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 {
 	struct sock *sk = (struct sock *) chan->private;
 	struct pppox_sock *po = pppox_sk(sk);
+	struct net *net = sock_net(sk);
 	struct pptp_opt *opt = &po->proto.pptp;
 	struct pptp_gre_header *hdr;
 	unsigned int header_len = sizeof(*hdr);
@@ -187,7 +188,7 @@ static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 	if (sk_pppox(po)->sk_state & PPPOX_DEAD)
 		goto tx_error;
 
-	rt = ip_route_output_ports(sock_net(sk), &fl4, NULL,
+	rt = ip_route_output_ports(net, &fl4, NULL,
 				   opt->dst_addr.sin_addr.s_addr,
 				   opt->src_addr.sin_addr.s_addr,
 				   0, 0, IPPROTO_GRE,
@@ -279,10 +280,10 @@ static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 	nf_reset(skb);
 
 	skb->ip_summed = CHECKSUM_NONE;
-	ip_select_ident(sock_net(sk), skb, NULL);
+	ip_select_ident(net, skb, NULL);
 	ip_send_check(iph);
 
-	ip_local_out(skb);
+	ip_local_out(net, skb->sk, skb);
 	return 1;
 
 tx_error:
diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index 64499766e00f..191579aeab16 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -74,9 +74,9 @@ static struct dst_entry *vrf_ip_check(struct dst_entry *dst, u32 cookie)
 	return dst;
 }
 
-static int vrf_ip_local_out(struct sk_buff *skb)
+static int vrf_ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
-	return ip_local_out(skb);
+	return ip_local_out(net, sk, skb);
 }
 
 static unsigned int vrf_v4_mtu(const struct dst_entry *dst)
@@ -222,7 +222,7 @@ static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
 					       RT_SCOPE_LINK);
 	}
 
-	ret = ip_local_out(skb);
+	ret = ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
 	if (unlikely(net_xmit_eval(ret)))
 		vrf_dev->stats.tx_errors++;
 	else
@@ -312,10 +312,9 @@ err:
 	return ret;
 }
 
-static int vrf_output(struct sock *sk, struct sk_buff *skb)
+static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
 	struct net_device *dev = skb_dst(skb)->dev;
-	struct net *net = dev_net(dev);
 
 	IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);