ipv6: enable anycast addresses as source addresses for datagrams

This change allows to consider an anycast address valid as source address
when given via an IPV6_PKTINFO or IPV6_2292PKTINFO ancillary data item.
So, when sending a datagram with ancillary data, the unicast and anycast
addresses are handled in the same way.

- Adds ipv6_chk_acast_addr_src() to check if an anycast address is link-local
  on given interface or is global.
- Uses it in ip6_datagram_send_ctl().

Signed-off-by: Francois-Xavier Le Bail <fx.lebail@yahoo.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/addrconf.h b/include/net/addrconf.h
index 66c4a44..50e39a8 100644 (file)
--- a/include/net/addrconf.h
+++ b/include/net/addrconf.h
@@ -205,8 +205,9 @@ void ipv6_sock_ac_close(struct sock *sk);
 int ipv6_dev_ac_inc(struct net_device *dev, const struct in6_addr *addr);
 int __ipv6_dev_ac_dec(struct inet6_dev *idev, const struct in6_addr *addr);
 bool ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
-                               const struct in6_addr *addr);
-
+                        const struct in6_addr *addr);
+bool ipv6_chk_acast_addr_src(struct net *net, struct net_device *dev,
+                            const struct in6_addr *addr);
 
 /* Device notifier */
 int register_inet6addr_notifier(struct notifier_block *nb);

diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index 5a80f15..2101832 100644 (file)
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -383,6 +383,17 @@ bool ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
        return found;
 }
 
+/*     check if this anycast address is link-local on given interface or
+ *     is global
+ */
+bool ipv6_chk_acast_addr_src(struct net *net, struct net_device *dev,
+                            const struct in6_addr *addr)
+{
+       return ipv6_chk_acast_addr(net,
+                                  (ipv6_addr_type(addr) & IPV6_ADDR_LINKLOCAL ?
+                                   dev : NULL),
+                                  addr);
+}
 
 #ifdef CONFIG_PROC_FS
 struct ac6_iter_state {

diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
index 2f5e2f1..c3bf2d2 100644 (file)
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -699,7 +699,9 @@ int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
                                int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
                                if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
                                    !ipv6_chk_addr(net, &src_info->ipi6_addr,
-                                                  strict ? dev : NULL, 0))
+                                                  strict ? dev : NULL, 0) &&
+                                   !ipv6_chk_acast_addr_src(net, dev,
+                                                            &src_info->ipi6_addr))
                                        err = -EINVAL;
                                else
                                        fl6->saddr = src_info->ipi6_addr;