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Reply-To: nicolas.dichtel@6wind.com
Subject: Re: [PATCH v2 4/5] net: ipv4: allow setting address on interface
 outside current namespace
To:     Jonas Bonn <jonas@norrbonn.se>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     davem@davemloft.net
References: <20191106053923.10414-1-jonas@norrbonn.se>
 <20191106053923.10414-5-jonas@norrbonn.se>
From:   Nicolas Dichtel <nicolas.dichtel@6wind.com>
Organization: 6WIND
Message-ID: <1f8a0f3e-e4ac-40c9-26e6-f14498ccdbe9@6wind.com>
Date:   Wed, 6 Nov 2019 22:06:33 +0100
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Le 06/11/2019 à 06:39, Jonas Bonn a écrit :
> This patch allows an interface outside of the current namespace to be
> selected when setting a new IPv4 address for a device.  This uses the
> IFA_TARGET_NETNSID attribute to select the namespace in which to search
> for the interface to act upon.
> 
> Signed-off-by: Jonas Bonn <jonas@norrbonn.se>
> ---
[snip]
> @@ -922,16 +917,37 @@ static int inet_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh,
>  			    struct netlink_ext_ack *extack)
>  {
>  	struct net *net = sock_net(skb->sk);
> +	struct net *tgt_net = NULL;
>  	struct in_ifaddr *ifa;
>  	struct in_ifaddr *ifa_existing;
>  	__u32 valid_lft = INFINITY_LIFE_TIME;
>  	__u32 prefered_lft = INFINITY_LIFE_TIME;
> +	struct nlattr *tb[IFA_MAX+1];
> +	int err;
>  
>  	ASSERT_RTNL();
>  
> -	ifa = rtm_to_ifaddr(net, nlh, &valid_lft, &prefered_lft, extack);
> -	if (IS_ERR(ifa))
> -		return PTR_ERR(ifa);
> +	err = nlmsg_parse_deprecated(nlh, sizeof(struct ifaddrmsg), tb, IFA_MAX,
> +				     ifa_ipv4_policy, extack);
> +	if (err < 0)
> +		return err;
> +
> +	if (tb[IFA_TARGET_NETNSID]) {
> +		int32_t netnsid = nla_get_s32(tb[IFA_TARGET_NETNSID]);
> +
> +		tgt_net = rtnl_get_net_ns_capable(NETLINK_CB(skb).sk, netnsid);
> +		if (IS_ERR(net)) {
if (IS_ERR(tgt_net)) ?

Nicolas