genetlink: make multicast groups const, prevent abuse
Register generic netlink multicast groups as an array with
the family and give them contiguous group IDs. Then instead
of passing the global group ID to the various functions that
send messages, pass the ID relative to the family - for most
families that's just 0 because the only have one group.
This avoids the list_head and ID in each group, adding a new
field for the mcast group ID offset to the family.
At the same time, this allows us to prevent abusing groups
again like the quota and dropmon code did, since we can now
check that a family only uses a group it owns.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/hsr/hsr_netlink.c b/net/hsr/hsr_netlink.c
index 0009416..5325af8 100644
--- a/net/hsr/hsr_netlink.c
+++ b/net/hsr/hsr_netlink.c
@@ -90,8 +90,8 @@
.maxattr = HSR_A_MAX,
};
-static struct genl_multicast_group hsr_network_genl_mcgrp = {
- .name = "hsr-network",
+static const struct genl_multicast_group hsr_mcgrps[] = {
+ { .name = "hsr-network", },
};
@@ -129,8 +129,7 @@
goto nla_put_failure;
genlmsg_end(skb, msg_head);
- genlmsg_multicast(&hsr_genl_family, skb, 0,
- hsr_network_genl_mcgrp.id, GFP_ATOMIC);
+ genlmsg_multicast(&hsr_genl_family, skb, 0, 0, GFP_ATOMIC);
return;
@@ -164,8 +163,7 @@
goto nla_put_failure;
genlmsg_end(skb, msg_head);
- genlmsg_multicast(&hsr_genl_family, skb, 0,
- hsr_network_genl_mcgrp.id, GFP_ATOMIC);
+ genlmsg_multicast(&hsr_genl_family, skb, 0, 0, GFP_ATOMIC);
return;
@@ -416,18 +414,13 @@
if (rc)
goto fail_rtnl_link_register;
- rc = genl_register_family_with_ops(&hsr_genl_family, hsr_ops);
+ rc = genl_register_family_with_ops_groups(&hsr_genl_family, hsr_ops,
+ hsr_mcgrps);
if (rc)
goto fail_genl_register_family;
- rc = genl_register_mc_group(&hsr_genl_family, &hsr_network_genl_mcgrp);
- if (rc)
- goto fail_genl_register_mc_group;
-
return 0;
-fail_genl_register_mc_group:
- genl_unregister_family(&hsr_genl_family);
fail_genl_register_family:
rtnl_link_unregister(&hsr_link_ops);
fail_rtnl_link_register:
