[PATCH net] vrf: Increment Icmp6InMsgs on the original netdev

[PATCH net] vrf: Increment Icmp6InMsgs on the original netdev

[Stephen Suryaputra]

Get the ingress interface and increment ICMP counters based on that
instead of skb->dev when the the dev is a VRF device.

This is a follow up on the following message:
https://www.spinics.net/lists/netdev/msg560268.html

Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
---
 net/ipv6/icmp.c       | 17 +++++++++++------
 net/ipv6/reassembly.c |  3 +++
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 802faa2fcc0e..f54191cd1d7b 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -398,23 +398,28 @@ static struct dst_entry *icmpv6_route_lookup(struct net *net,
 	return ERR_PTR(err);
 }
 
-static int icmp6_iif(const struct sk_buff *skb)
+static struct net_device *icmp6_dev(const struct sk_buff *skb)
 {
-	int iif = skb->dev->ifindex;
+	struct net_device *dev = skb->dev;
 
 	/* for local traffic to local address, skb dev is the loopback
 	 * device. Check if there is a dst attached to the skb and if so
 	 * get the real device index. Same is needed for replies to a link
 	 * local address on a device enslaved to an L3 master device
 	 */
-	if (unlikely(iif == LOOPBACK_IFINDEX || netif_is_l3_master(skb->dev))) {
+	if (unlikely(dev->ifindex == LOOPBACK_IFINDEX || netif_is_l3_master(skb->dev))) {
 		const struct rt6_info *rt6 = skb_rt6_info(skb);
 
 		if (rt6)
-			iif = rt6->rt6i_idev->dev->ifindex;
+			dev = rt6->rt6i_idev->dev;
 	}
 
-	return iif;
+	return dev;
+}
+
+static int icmp6_iif(const struct sk_buff *skb)
+{
+	return icmp6_dev(skb)->ifindex;
 }
 
 /*
@@ -801,7 +806,7 @@ void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
 static int icmpv6_rcv(struct sk_buff *skb)
 {
 	struct net *net = dev_net(skb->dev);
-	struct net_device *dev = skb->dev;
+	struct net_device *dev = icmp6_dev(skb);
 	struct inet6_dev *idev = __in6_dev_get(dev);
 	const struct in6_addr *saddr, *daddr;
 	struct icmp6hdr *hdr;
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 1a832f5e190b..9b365c345c34 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -260,6 +260,9 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *skb,
 	int payload_len;
 	u8 ecn;
 
+	if (netif_is_l3_master(dev))
+		dev = dev_get_by_index_rcu(net, inet6_iif(skb));
+
 	inet_frag_kill(&fq->q);
 
 	ecn = ip_frag_ecn_table[fq->ecn];
-- 
2.17.1

Re: [PATCH net] vrf: Increment Icmp6InMsgs on the original netdev

[David Miller]

From: Stephen Suryaputra <ssuryaextr@gmail.com>
Date: Thu, 30 May 2019 01:08:15 -0400

> Get the ingress interface and increment ICMP counters based on that
> instead of skb->dev when the the dev is a VRF device.
> 
> This is a follow up on the following message:
> https://www.spinics.net/lists/netdev/msg560268.html
> 
> Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>

David, please review.

Re: [PATCH net] vrf: Increment Icmp6InMsgs on the original netdev

[David Ahern]

On 5/29/19 11:08 PM, Stephen Suryaputra wrote:
> diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
> index 1a832f5e190b..9b365c345c34 100644
> --- a/net/ipv6/reassembly.c
> +++ b/net/ipv6/reassembly.c
> @@ -260,6 +260,9 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *skb,
>  	int payload_len;
>  	u8 ecn;
>  
> +	if (netif_is_l3_master(dev))
> +		dev = dev_get_by_index_rcu(net, inet6_iif(skb));
> +
>  	inet_frag_kill(&fq->q);
>  
>  	ecn = ip_frag_ecn_table[fq->ecn];
> 

this part changes skb->dev. Seems like it has an unintended effect if
the packet is delivered locally.

Re: [PATCH net] vrf: Increment Icmp6InMsgs on the original netdev

[Stephen Suryaputra]

On Fri, May 31, 2019 at 05:06:16PM -0600, David Ahern wrote:
> On 5/29/19 11:08 PM, Stephen Suryaputra wrote:
> > diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
> > index 1a832f5e190b..9b365c345c34 100644
> > --- a/net/ipv6/reassembly.c
> > +++ b/net/ipv6/reassembly.c
> > @@ -260,6 +260,9 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *skb,
> >  	int payload_len;
> >  	u8 ecn;
> >  
> > +	if (netif_is_l3_master(dev))
> > +		dev = dev_get_by_index_rcu(net, inet6_iif(skb));
> > +
> >  	inet_frag_kill(&fq->q);
> >  
> >  	ecn = ip_frag_ecn_table[fq->ecn];
> > 
> 
> this part changes skb->dev. Seems like it has an unintended effect if
> the packet is delivered locally.

Ah, right. How about this then?

+/**
+ * __in6_dev_stats_get - get inet6_dev pointer for stats
+ * @dev: network device
+ * @skb: skb for original incoming interface if neeeded
+ *
+ * Caller must hold rcu_read_lock or RTNL, because this function
+ * does not take a reference on the inet6_dev.
+ */
+static inline struct inet6_dev *__in6_dev_stats_get(const struct net_device *dev,
+						    const struct sk_buff *skb)
+{
+	if (netif_is_l3_master(dev))
+		dev = dev_get_by_index_rcu(dev_net(dev), inet6_iif(skb));
+	return __in6_dev_get(dev);
+}

@@ -260,9 +260,6 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *skb,
 	int payload_len;
 	u8 ecn;
 
-	if (netif_is_l3_master(dev))
-		dev = dev_get_by_index_rcu(net, inet6_iif(skb));
-
 	inet_frag_kill(&fq->q);
 
 	ecn = ip_frag_ecn_table[fq->ecn];
@@ -305,7 +302,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *skb,
 			   skb_network_header_len(skb));
 
 	rcu_read_lock();
-	__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
+	__IP6_INC_STATS(net, __in6_dev_stats_get(dev, skb), IPSTATS_MIB_REASMOKS);
 	rcu_read_unlock();
 	fq->q.rb_fragments = RB_ROOT;
 	fq->q.fragments_tail = NULL;
@@ -319,7 +316,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *skb,
 	net_dbg_ratelimited("ip6_frag_reasm: no memory for reassembly\n");
 out_fail:
 	rcu_read_lock();
-	__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
+	__IP6_INC_STATS(net, __in6_dev_stats_get(dev, skb), IPSTATS_MIB_REASMFAILS);
 	rcu_read_unlock();
 	inet_frag_kill(&fq->q);
 	return -1;

Thanks.

Re: [PATCH net] vrf: Increment Icmp6InMsgs on the original netdev

[David Ahern]

On 6/1/19 12:14 PM, Stephen Suryaputra wrote:
> On Fri, May 31, 2019 at 05:06:16PM -0600, David Ahern wrote:
>> On 5/29/19 11:08 PM, Stephen Suryaputra wrote:
>>> diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
>>> index 1a832f5e190b..9b365c345c34 100644
>>> --- a/net/ipv6/reassembly.c
>>> +++ b/net/ipv6/reassembly.c
>>> @@ -260,6 +260,9 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *skb,
>>>  	int payload_len;
>>>  	u8 ecn;
>>>  
>>> +	if (netif_is_l3_master(dev))
>>> +		dev = dev_get_by_index_rcu(net, inet6_iif(skb));
>>> +
>>>  	inet_frag_kill(&fq->q);
>>>  
>>>  	ecn = ip_frag_ecn_table[fq->ecn];
>>>
>>
>> this part changes skb->dev. Seems like it has an unintended effect if
>> the packet is delivered locally.
> 
> Ah, right. How about this then?
> 

looks ok to me.