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>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 843406f..af26cc10 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1325,6 +1325,16 @@
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 @@
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 @@
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 @@
#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;