[net,v2] vrf: Increment Icmp6InMsgs on the original netdev

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

v2: Avoid changing skb->dev since it has unintended effect for local
    delivery (David Ahern).
Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
---
 include/net/addrconf.h | 16 ++++++++++++++++
 net/ipv6/icmp.c        | 17 +++++++++++------
 net/ipv6/reassembly.c  |  4 ++--
 3 files changed, 29 insertions(+), 8 deletions(-)

From: Stephen Suryaputra <ssuryaextr@gmail.com>
Date: Mon, 10 Jun 2019 10:32:50 -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
> 
> v2: Avoid changing skb->dev since it has unintended effect for local
>     delivery (David Ahern).
> Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>

David, please review.

Thanks.

> ---
>  include/net/addrconf.h | 16 ++++++++++++++++
>  net/ipv6/icmp.c        | 17 +++++++++++------
>  net/ipv6/reassembly.c  |  4 ++--
>  3 files changed, 29 insertions(+), 8 deletions(-)
> 
> diff --git a/include/net/addrconf.h b/include/net/addrconf.h
> index 269ec27385e9..2e36e29f9f54 100644
> --- a/include/net/addrconf.h
> +++ b/include/net/addrconf.h
> @@ -356,6 +356,22 @@ static inline struct inet6_dev *__in6_dev_get(const struct net_device *dev)
>  	return rcu_dereference_rtnl(dev->ip6_ptr);
>  }
>  
> +/**
> + * __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);
> +}
> +
>  /**
>   * __in6_dev_get_safely - get inet6_dev pointer from netdevice
>   * @dev: network device
> 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..e219e669ac11 100644
> --- a/net/ipv6/reassembly.c
> +++ b/net/ipv6/reassembly.c
> @@ -302,7 +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;
> @@ -316,7 +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;
> -- 
> 2.17.1
>

On 6/10/19 8:32 AM, Stephen Suryaputra wrote:
> 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
> 
> v2: Avoid changing skb->dev since it has unintended effect for local
>     delivery (David Ahern).
> Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
> ---
>  include/net/addrconf.h | 16 ++++++++++++++++
>  net/ipv6/icmp.c        | 17 +++++++++++------
>  net/ipv6/reassembly.c  |  4 ++--
>  3 files changed, 29 insertions(+), 8 deletions(-)

Reviewed-by: David Ahern <dsahern@gmail.com>

From: Stephen Suryaputra <ssuryaextr@gmail.com>
Date: Mon, 10 Jun 2019 10:32:50 -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
> 
> v2: Avoid changing skb->dev since it has unintended effect for local
>     delivery (David Ahern).
> Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>

Applied.