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Commit 9f0f7272 authored by Thomas Graf's avatar Thomas Graf Committed by David S. Miller
Browse files

ipv4: AF_INET link address family 

Implements the AF_INET link address family exposing the per
device configuration settings via netlink using the attribute
IFLA_INET_CONF.

The format of IFLA_INET_CONF differs depending on the direction
the attribute is sent. The attribute sent by the kernel consists
of a u32 array, basically a 1:1 copy of in_device->cnf.data[].
The attribute expected by the kernel must consist of a sequence
of nested u32 attributes, each representing a change request,
e.g.
	[IFLA_INET_CONF] = {
		[IPV4_DEVCONF_FORWARDING] = 1,
		[IPV4_DEVCONF_NOXFRM] = 0,
	}

libnl userspace API documentation and example available from:
http://www.infradead.org/~tgr/libnl/doc-git/group__link__inet.html



Signed-off-by: default avatarThomas Graf <tgraf@infradead.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ca7479eb

include/linux/if_link.h

+8 −0
Original line number Diff line number Diff line
@@ -147,6 +147,14 @@ enum { 
#define IFLA_PAYLOAD(n) NLMSG_PAYLOAD(n,sizeof(struct ifinfomsg))

#endif



enum {

	IFLA_INET_UNSPEC,

	IFLA_INET_CONF,

	__IFLA_INET_MAX,

};



#define IFLA_INET_MAX (__IFLA_INET_MAX - 1)



/* ifi_flags.



   IFF_* flags.

net/ipv4/devinet.c

+75 −0
Original line number Diff line number Diff line
@@ -1256,6 +1256,72 @@ static void rtmsg_ifa(int event, struct in_ifaddr *ifa, struct nlmsghdr *nlh, 
		rtnl_set_sk_err(net, RTNLGRP_IPV4_IFADDR, err);

}



static size_t inet_get_link_af_size(const struct net_device *dev)

{

	struct in_device *in_dev = __in_dev_get_rcu(dev);



	if (!in_dev)

		return 0;



	return nla_total_size(IPV4_DEVCONF_MAX * 4); /* IFLA_INET_CONF */

}



static int inet_fill_link_af(struct sk_buff *skb, const struct net_device *dev)

{

	struct in_device *in_dev = __in_dev_get_rcu(dev);

	struct nlattr *nla;

	int i;



	if (!in_dev)

		return -ENODATA;



	nla = nla_reserve(skb, IFLA_INET_CONF, IPV4_DEVCONF_MAX * 4);

	if (nla == NULL)

		return -EMSGSIZE;



	for (i = 0; i < IPV4_DEVCONF_MAX; i++)

		((u32 *) nla_data(nla))[i] = in_dev->cnf.data[i];



	return 0;

}



static const struct nla_policy inet_af_policy[IFLA_INET_MAX+1] = {

	[IFLA_INET_CONF]	= { .type = NLA_NESTED },

};



static int inet_parse_link_af(struct net_device *dev, const struct nlattr *nla)

{

	struct in_device *in_dev = __in_dev_get_rcu(dev);

	struct nlattr *a, *tb[IFLA_INET_MAX+1];

	int err, rem;



	if (!in_dev)

		return -EOPNOTSUPP;



	err = nla_parse_nested(tb, IFLA_INET_MAX, nla, inet_af_policy);

	if (err < 0)

		return err;



	if (tb[IFLA_INET_CONF]) {

		nla_for_each_nested(a, tb[IFLA_INET_CONF], rem) {

			int cfgid = nla_type(a);



			if (nla_len(a) < 4)

				return -EINVAL;



			if (cfgid <= 0 || cfgid > IPV4_DEVCONF_MAX)

				return -EINVAL;

		}

	}



	if (tb[IFLA_INET_CONF]) {

		nla_for_each_nested(a, tb[IFLA_INET_CONF], rem)

			ipv4_devconf_set(in_dev, nla_type(a), nla_get_u32(a));

	}



	return 0;

}



#ifdef CONFIG_SYSCTL



static void devinet_copy_dflt_conf(struct net *net, int i)
@@ -1619,6 +1685,13 @@ static __net_initdata struct pernet_operations devinet_ops = { 
	.exit = devinet_exit_net,

};



static struct rtnl_af_ops inet_af_ops = {

	.family		  = AF_INET,

	.fill_link_af	  = inet_fill_link_af,

	.get_link_af_size = inet_get_link_af_size,

	.parse_link_af	  = inet_parse_link_af,

};



void __init devinet_init(void)

{

	register_pernet_subsys(&devinet_ops);
@@ -1626,6 +1699,8 @@ void __init devinet_init(void) 
	register_gifconf(PF_INET, inet_gifconf);

	register_netdevice_notifier(&ip_netdev_notifier);



	rtnl_af_register(&inet_af_ops);



	rtnl_register(PF_INET, RTM_NEWADDR, inet_rtm_newaddr, NULL);

	rtnl_register(PF_INET, RTM_DELADDR, inet_rtm_deladdr, NULL);

	rtnl_register(PF_INET, RTM_GETADDR, NULL, inet_dump_ifaddr);