Commit c3968a85 authored by Daniel Walter's avatar Daniel Walter Committed by David S. Miller
Browse files

ipv6: RTA_PREFSRC support for ipv6 route source address selection 



[ipv6] Add support for RTA_PREFSRC

This patch allows a user to select the preferred source address
for a specific IPv6-Route. It can be set via a netlink message
setting RTA_PREFSRC to a valid IPv6 address which must be
up on the device the route will be bound to.

Signed-off-by: default avatarDaniel Walter <dwalter@barracuda.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent bd015928

include/net/ip6_fib.h

+2 −0
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ struct fib6_config { 


	struct in6_addr	fc_dst;

	struct in6_addr	fc_src;

	struct in6_addr	fc_prefsrc;

	struct in6_addr	fc_gateway;



	unsigned long	fc_expires;
@@ -107,6 +108,7 @@ struct rt6_info { 
	struct rt6key			rt6i_dst ____cacheline_aligned_in_smp;

	u32				rt6i_flags;

	struct rt6key			rt6i_src;

	struct rt6key			rt6i_prefsrc;

	u32				rt6i_metric;

	u32				rt6i_peer_genid;

include/net/ip6_route.h

+7 −0
Original line number Diff line number Diff line
@@ -84,6 +84,12 @@ extern int ip6_route_add(struct fib6_config *cfg); 
extern int			ip6_ins_rt(struct rt6_info *);

extern int			ip6_del_rt(struct rt6_info *);



extern int			ip6_route_get_saddr(struct net *net,

						    struct rt6_info *rt,

						    struct in6_addr *daddr,

						    unsigned int prefs,

						    struct in6_addr *saddr);



extern struct rt6_info		*rt6_lookup(struct net *net,

					    const struct in6_addr *daddr,

					    const struct in6_addr *saddr,
@@ -141,6 +147,7 @@ struct rt6_rtnl_dump_arg { 
extern int rt6_dump_route(struct rt6_info *rt, void *p_arg);

extern void rt6_ifdown(struct net *net, struct net_device *dev);

extern void rt6_mtu_change(struct net_device *dev, unsigned mtu);

extern void rt6_remove_prefsrc(struct inet6_ifaddr *ifp);





/*

net/ipv6/addrconf.c

+2 −0
Original line number Diff line number Diff line
@@ -825,6 +825,8 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp) 
		dst_release(&rt->dst);

	}



	/* clean up prefsrc entries */

	rt6_remove_prefsrc(ifp);

out:

	in6_ifa_put(ifp);

}

net/ipv6/ip6_output.c

+4 −4
Original line number Diff line number Diff line
@@ -930,8 +930,8 @@ static int ip6_dst_lookup_tail(struct sock *sk, 
		goto out_err_release;



	if (ipv6_addr_any(&fl6->saddr)) {

		err = ipv6_dev_get_saddr(net, ip6_dst_idev(*dst)->dev,

					 &fl6->daddr,

		struct rt6_info *rt = (struct rt6_info *) *dst;

		err = ip6_route_get_saddr(net, rt, &fl6->daddr,

					  sk ? inet6_sk(sk)->srcprefs : 0,

					  &fl6->saddr);

		if (err)

net/ipv6/route.c

+69 −3
Original line number Diff line number Diff line
@@ -1325,6 +1325,16 @@ int ip6_route_add(struct fib6_config *cfg) 
	if (dev == NULL)

		goto out;



	if (!ipv6_addr_any(&cfg->fc_prefsrc)) {

		if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {

			err = -EINVAL;

			goto out;

		}

		ipv6_addr_copy(&rt->rt6i_prefsrc.addr, &cfg->fc_prefsrc);

		rt->rt6i_prefsrc.plen = 128;

	} else

		rt->rt6i_prefsrc.plen = 0;



	if (cfg->fc_flags & (RTF_GATEWAY | RTF_NONEXTHOP)) {

		rt->rt6i_nexthop = __neigh_lookup_errno(&nd_tbl, &rt->rt6i_gateway, dev);

		if (IS_ERR(rt->rt6i_nexthop)) {
@@ -2037,6 +2047,55 @@ struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev, 
	return rt;

}



int ip6_route_get_saddr(struct net *net,

			struct rt6_info *rt,

			struct in6_addr *daddr,

			unsigned int prefs,

			struct in6_addr *saddr)

{

	struct inet6_dev *idev = ip6_dst_idev((struct dst_entry*)rt);

	int err = 0;

	if (rt->rt6i_prefsrc.plen)

		ipv6_addr_copy(saddr, &rt->rt6i_prefsrc.addr);

	else

		err = ipv6_dev_get_saddr(net, idev ? idev->dev : NULL,

					 daddr, prefs, saddr);

	return err;

}



/* remove deleted ip from prefsrc entries */

struct arg_dev_net_ip {

	struct net_device *dev;

	struct net *net;

	struct in6_addr *addr;

};



static int fib6_remove_prefsrc(struct rt6_info *rt, void *arg)

{

	struct net_device *dev = ((struct arg_dev_net_ip *)arg)->dev;

	struct net *net = ((struct arg_dev_net_ip *)arg)->net;

	struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;



	if (((void *)rt->rt6i_dev == dev || dev == NULL) &&

	    rt != net->ipv6.ip6_null_entry &&

	    ipv6_addr_equal(addr, &rt->rt6i_prefsrc.addr)) {

		/* remove prefsrc entry */

		rt->rt6i_prefsrc.plen = 0;

	}

	return 0;

}



void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)

{

	struct net *net = dev_net(ifp->idev->dev);

	struct arg_dev_net_ip adni = {

		.dev = ifp->idev->dev,

		.net = net,

		.addr = &ifp->addr,

	};

	fib6_clean_all(net, fib6_remove_prefsrc, 0, &adni);

}



struct arg_dev_net {

	struct net_device *dev;

	struct net *net;
@@ -2183,6 +2242,9 @@ static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh, 
		nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);

	}



	if (tb[RTA_PREFSRC])

		nla_memcpy(&cfg->fc_prefsrc, tb[RTA_PREFSRC], 16);



	if (tb[RTA_OIF])

		cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
@@ -2325,10 +2387,14 @@ static int rt6_fill_node(struct net *net, 
#endif

			NLA_PUT_U32(skb, RTA_IIF, iif);

	} else if (dst) {

		struct inet6_dev *idev = ip6_dst_idev(&rt->dst);

		struct in6_addr saddr_buf;

		if (ipv6_dev_get_saddr(net, idev ? idev->dev : NULL,

				       dst, 0, &saddr_buf) == 0)

		if (ip6_route_get_saddr(net, rt, dst, 0, &saddr_buf) == 0)

			NLA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf);

	}



	if (rt->rt6i_prefsrc.plen) {

		struct in6_addr saddr_buf;

		ipv6_addr_copy(&saddr_buf, &rt->rt6i_prefsrc.addr);

		NLA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf);

	}

CRA Git | Maintained and supported by SUSTech CRA and CCSE