Re: [tipc-discussion] [PATCH net 1/2] ipv6: add ipv6_dev_find()

[Ying X. <yin...@wi...>]

On 8/3/20 11:34 PM, Xin Long wrote:
> This is to add an ip_dev_find like function for ipv6, used to find
> the dev by saddr.
> 
> It will be used by TIPC protocol. So also export it.
> 
> Signed-off-by: Xin Long <luc...@gm...>

Acked-by: Ying Xue <yin...@wi...>

> ---
>  include/net/addrconf.h |  2 ++
>  net/ipv6/addrconf.c    | 39 +++++++++++++++++++++++++++++++++++++++
>  2 files changed, 41 insertions(+)
> 
> diff --git a/include/net/addrconf.h b/include/net/addrconf.h
> index 8418b7d..ba3f6c15 100644
> --- a/include/net/addrconf.h
> +++ b/include/net/addrconf.h
> @@ -97,6 +97,8 @@ bool ipv6_chk_custom_prefix(const struct in6_addr *addr,
>  
>  int ipv6_chk_prefix(const struct in6_addr *addr, struct net_device *dev);
>  
> +struct net_device *ipv6_dev_find(struct net *net, const struct in6_addr *addr);
> +
>  struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net,
>  				     const struct in6_addr *addr,
>  				     struct net_device *dev, int strict);
> diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
> index 840bfdb..857d6f9 100644
> --- a/net/ipv6/addrconf.c
> +++ b/net/ipv6/addrconf.c
> @@ -1983,6 +1983,45 @@ int ipv6_chk_prefix(const struct in6_addr *addr, struct net_device *dev)
>  }
>  EXPORT_SYMBOL(ipv6_chk_prefix);
>  
> +/**
> + * ipv6_dev_find - find the first device with a given source address.
> + * @net: the net namespace
> + * @addr: the source address
> + *
> + * The caller should be protected by RCU, or RTNL.
> + */
> +struct net_device *ipv6_dev_find(struct net *net, const struct in6_addr *addr)
> +{
> +	unsigned int hash = inet6_addr_hash(net, addr);
> +	struct inet6_ifaddr *ifp, *result = NULL;
> +	struct net_device *dev = NULL;
> +
> +	rcu_read_lock();
> +	hlist_for_each_entry_rcu(ifp, &inet6_addr_lst[hash], addr_lst) {
> +		if (net_eq(dev_net(ifp->idev->dev), net) &&
> +		    ipv6_addr_equal(&ifp->addr, addr)) {
> +			result = ifp;
> +			break;
> +		}
> +	}
> +
> +	if (!result) {
> +		struct rt6_info *rt;
> +
> +		rt = rt6_lookup(net, addr, NULL, 0, NULL, 0);
> +		if (rt) {
> +			dev = rt->dst.dev;
> +			ip6_rt_put(rt);
> +		}
> +	} else {
> +		dev = result->idev->dev;
> +	}
> +	rcu_read_unlock();
> +
> +	return dev;
> +}
> +EXPORT_SYMBOL(ipv6_dev_find);
> +
>  struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net, const struct in6_addr *addr,
>  				     struct net_device *dev, int strict)
>  {
>