tipc: add peer removal functionality

Add TIPC_NL_PEER_REMOVE netlink command. This command can remove
an offline peer node from the internal data structures.

This will be supported by the tipc user space tool in iproute2.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 71 insertions, 0 deletions

diff --git a/net/tipc/net.h b/net/tipc/net.h
index 77a7a118911d..c7c254902873 100644
--- a/net/tipc/net.h
+++ b/net/tipc/net.h
@@ -39,6 +39,8 @@
 
 #include <net/genetlink.h>
 
+extern const struct nla_policy tipc_nl_net_policy[];
+
 int tipc_net_start(struct net *net, u32 addr);
 
 void tipc_net_stop(struct net *net);
diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c
index a84daec0afe9..2718de667828 100644
--- a/net/tipc/netlink.c
+++ b/net/tipc/netlink.c
@@ -238,6 +238,11 @@ static const struct genl_ops tipc_genl_v2_ops[] = {
                 .dumpit = tipc_nl_node_dump_monitor_peer,
                 .policy = tipc_nl_policy,
         },
+        {
+                .cmd    = TIPC_NL_PEER_REMOVE,
+                .doit   = tipc_nl_peer_rm,
+                .policy = tipc_nl_policy,
+        }
 };
 
 int tipc_nlmsg_parse(const struct nlmsghdr *nlh, struct nlattr ***attr)
diff --git a/net/tipc/node.c b/net/tipc/node.c
index 21974191e425..7e8b75fd1a02 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -1553,6 +1553,69 @@ discard:
         kfree_skb(skb);
 }
 
+int tipc_nl_peer_rm(struct sk_buff *skb, struct genl_info *info)
+{
+        struct net *net = sock_net(skb->sk);
+        struct tipc_net *tn = net_generic(net, tipc_net_id);
+        struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
+        struct tipc_node *peer;
+        u32 addr;
+        int err;
+        int i;
+
+        /* We identify the peer by its net */
+        if (!info->attrs[TIPC_NLA_NET])
+                return -EINVAL;
+
+        err = nla_parse_nested(attrs, TIPC_NLA_NET_MAX,
+                               info->attrs[TIPC_NLA_NET],
+                               tipc_nl_net_policy);
+        if (err)
+                return err;
+
+        if (!attrs[TIPC_NLA_NET_ADDR])
+                return -EINVAL;
+
+        addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
+
+        if (in_own_node(net, addr))
+                return -ENOTSUPP;
+
+        spin_lock_bh(&tn->node_list_lock);
+        peer = tipc_node_find(net, addr);
+        if (!peer) {
+                spin_unlock_bh(&tn->node_list_lock);
+                return -ENXIO;
+        }
+
+        tipc_node_write_lock(peer);
+        if (peer->state != SELF_DOWN_PEER_DOWN &&
+            peer->state != SELF_DOWN_PEER_LEAVING) {
+                tipc_node_write_unlock(peer);
+                err = -EBUSY;
+                goto err_out;
+        }
+
+        for (i = 0; i < MAX_BEARERS; i++) {
+                struct tipc_link_entry *le = &peer->links[i];
+
+                if (le->link) {
+                        kfree(le->link);
+                        le->link = NULL;
+                        peer->link_cnt--;
+                }
+        }
+        tipc_node_write_unlock(peer);
+        tipc_node_delete(peer);
+
+        err = 0;
+err_out:
+        tipc_node_put(peer);
+        spin_unlock_bh(&tn->node_list_lock);
+
+        return err;
+}
+
 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
 {
         int err;
diff --git a/net/tipc/node.h b/net/tipc/node.h
index d69fdfcc0ec9..4578b34c7dca 100644
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -77,6 +77,7 @@ int tipc_nl_node_dump_link(struct sk_buff *skb, struct netlink_callback *cb);
 int tipc_nl_node_reset_link_stats(struct sk_buff *skb, struct genl_info *info);
 int tipc_nl_node_get_link(struct sk_buff *skb, struct genl_info *info);
 int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info);
+int tipc_nl_peer_rm(struct sk_buff *skb, struct genl_info *info);
 
 int tipc_nl_node_set_monitor(struct sk_buff *skb, struct genl_info *info);
 int tipc_nl_node_get_monitor(struct sk_buff *skb, struct genl_info *info);