genetlink: pass multicast bind/unbind to families
authorJohannes Berg <johannes.berg@intel.com>
Tue, 23 Dec 2014 19:54:40 +0000 (20:54 +0100)
committerDavid S. Miller <davem@davemloft.net>
Sat, 27 Dec 2014 07:20:23 +0000 (02:20 -0500)
In order to make the newly fixed multicast bind/unbind
functionality in generic netlink, pass them down to the
appropriate family.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/net/genetlink.h
net/netlink/genetlink.c

index 38620da..3ed31e5 100644 (file)
@@ -31,6 +31,9 @@ struct genl_info;
  *     do additional, common, filtering and return an error
  * @post_doit: called after an operation's doit callback, it may
  *     undo operations done by pre_doit, for example release locks
+ * @mcast_bind: a socket bound to the given multicast group (which
+ *     is given as the offset into the groups array)
+ * @mcast_unbind: a socket was unbound from the given multicast group
  * @attrbuf: buffer to store parsed attributes
  * @family_list: family list
  * @mcgrps: multicast groups used by this family (private)
@@ -53,6 +56,8 @@ struct genl_family {
        void                    (*post_doit)(const struct genl_ops *ops,
                                             struct sk_buff *skb,
                                             struct genl_info *info);
+       int                     (*mcast_bind)(int group);
+       void                    (*mcast_unbind)(int group);
        struct nlattr **        attrbuf;        /* private */
        const struct genl_ops * ops;            /* private */
        const struct genl_multicast_group *mcgrps; /* private */
index 76393f2..05bf40b 100644 (file)
@@ -983,11 +983,70 @@ static struct genl_multicast_group genl_ctrl_groups[] = {
        { .name = "notify", },
 };
 
+static int genl_bind(int group)
+{
+       int i, err;
+       bool found = false;
+
+       down_read(&cb_lock);
+       for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
+               struct genl_family *f;
+
+               list_for_each_entry(f, genl_family_chain(i), family_list) {
+                       if (group >= f->mcgrp_offset &&
+                           group < f->mcgrp_offset + f->n_mcgrps) {
+                               int fam_grp = group - f->mcgrp_offset;
+
+                               if (f->mcast_bind)
+                                       err = f->mcast_bind(fam_grp);
+                               else
+                                       err = 0;
+                               found = true;
+                               break;
+                       }
+               }
+       }
+       up_read(&cb_lock);
+
+       if (WARN_ON(!found))
+               err = 0;
+
+       return err;
+}
+
+static void genl_unbind(int group)
+{
+       int i;
+       bool found = false;
+
+       down_read(&cb_lock);
+       for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
+               struct genl_family *f;
+
+               list_for_each_entry(f, genl_family_chain(i), family_list) {
+                       if (group >= f->mcgrp_offset &&
+                           group < f->mcgrp_offset + f->n_mcgrps) {
+                               int fam_grp = group - f->mcgrp_offset;
+
+                               if (f->mcast_unbind)
+                                       f->mcast_unbind(fam_grp);
+                               found = true;
+                               break;
+                       }
+               }
+       }
+       up_read(&cb_lock);
+
+       WARN_ON(!found);
+}
+
 static int __net_init genl_pernet_init(struct net *net)
 {
        struct netlink_kernel_cfg cfg = {
                .input          = genl_rcv,
                .flags          = NL_CFG_F_NONROOT_RECV,
+               .bind           = genl_bind,
+               .unbind         = genl_unbind,
        };
 
        /* we'll bump the group number right afterwards */