1 files changed, 38 insertions, 18 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 358edd2272ac..4c03c2843094 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2730,9 +2730,25 @@ static void addrconf_add_linklocal(struct inet6_dev *idev, const struct in6_addr
         }
 }
 
+static void addrconf_addr_gen(struct inet6_dev *idev, bool prefix_route)
+{
+        if (idev->addr_gen_mode == IN6_ADDR_GEN_MODE_EUI64) {
+                struct in6_addr addr;
+
+                ipv6_addr_set(&addr,  htonl(0xFE800000), 0, 0, 0);
+                /* addrconf_add_linklocal also adds a prefix_route and we
+                 * only need to care about prefix routes if ipv6_generate_eui64
+                 * couldn't generate one.
+                 */
+                if (ipv6_generate_eui64(addr.s6_addr + 8, idev->dev) == 0)
+                        addrconf_add_linklocal(idev, &addr);
+                else if (prefix_route)
+                        addrconf_prefix_route(&addr, 64, idev->dev, 0, 0);
+        }
+}
+
 static void addrconf_dev_config(struct net_device *dev)
 {
-        struct in6_addr addr;
         struct inet6_dev *idev;
 
         ASSERT_RTNL();
@@ -2753,11 +2769,7 @@ static void addrconf_dev_config(struct net_device *dev)
         if (IS_ERR(idev))
                 return;
 
-        memset(&addr, 0, sizeof(struct in6_addr));
-        addr.s6_addr32[0] = htonl(0xFE800000);
-
-        if (ipv6_generate_eui64(addr.s6_addr + 8, dev) == 0)
-                addrconf_add_linklocal(idev, &addr);
+        addrconf_addr_gen(idev, false);
 }
 
 #if IS_ENABLED(CONFIG_IPV6_SIT)
@@ -2779,11 +2791,7 @@ static void addrconf_sit_config(struct net_device *dev)
         }
 
         if (dev->priv_flags & IFF_ISATAP) {
-                struct in6_addr addr;
-
-                ipv6_addr_set(&addr,  htonl(0xFE800000), 0, 0, 0);
-                if (!ipv6_generate_eui64(addr.s6_addr + 8, dev))
-                        addrconf_add_linklocal(idev, &addr);
+                addrconf_addr_gen(idev, false);
                 return;
         }
 
@@ -2798,7 +2806,6 @@ static void addrconf_sit_config(struct net_device *dev)
 static void addrconf_gre_config(struct net_device *dev)
 {
         struct inet6_dev *idev;
-        struct in6_addr addr;
 
         ASSERT_RTNL();
 
@@ -2807,11 +2814,7 @@ static void addrconf_gre_config(struct net_device *dev)
                 return;
         }
 
-        ipv6_addr_set(&addr,  htonl(0xFE800000), 0, 0, 0);
-        if (!ipv6_generate_eui64(addr.s6_addr + 8, dev))
-                addrconf_add_linklocal(idev, &addr);
-        else
-                addrconf_prefix_route(&addr, 64, dev, 0, 0);
+        addrconf_addr_gen(idev, true);
 }
 #endif
 
@@ -4423,6 +4426,10 @@ static int inet6_fill_ifla6_attrs(struct sk_buff *skb, struct inet6_dev *idev)
         nla = nla_reserve(skb, IFLA_INET6_TOKEN, sizeof(struct in6_addr));
         if (nla == NULL)
                 goto nla_put_failure;
+
+        if (nla_put_u8(skb, IFLA_INET6_ADDR_GEN_MODE, idev->addr_gen_mode))
+                goto nla_put_failure;
+
         read_lock_bh(&idev->lock);
         memcpy(nla_data(nla), idev->token.s6_addr, nla_len(nla));
         read_unlock_bh(&idev->lock);
@@ -4527,8 +4534,21 @@ static int inet6_set_link_af(struct net_device *dev, const struct nlattr *nla)
         if (nla_parse_nested(tb, IFLA_INET6_MAX, nla, NULL) < 0)
                 BUG();
 
-        if (tb[IFLA_INET6_TOKEN])
+        if (tb[IFLA_INET6_TOKEN]) {
                 err = inet6_set_iftoken(idev, nla_data(tb[IFLA_INET6_TOKEN]));
+                if (err)
+                        return err;
+        }
+
+        if (tb[IFLA_INET6_ADDR_GEN_MODE]) {
+                u8 mode = nla_get_u8(tb[IFLA_INET6_ADDR_GEN_MODE]);
+
+                if (mode != IN6_ADDR_GEN_MODE_EUI64 &&
+                    mode != IN6_ADDR_GEN_MODE_NONE)
+                        return -EINVAL;
+                idev->addr_gen_mode = mode;
+                err = 0;
+        }
 
         return err;
 }