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: Daniel Walter <dwalter@barracuda.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Daniel Walter 2011-04-13 21:10:57 +00:00 committed by David S. Miller
parent bd015928bb
commit c3968a857a
5 changed files with 84 additions and 7 deletions

View File

@ -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;

View File

@ -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);
/*

View File

@ -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);
}

View File

@ -930,10 +930,10 @@ 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,
sk ? inet6_sk(sk)->srcprefs : 0,
&fl6->saddr);
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)
goto out_err_release;
}

View File

@ -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]);
@ -2325,13 +2387,17 @@ 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);
}
if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
goto nla_put_failure;