tipc: add net dump to new netlink api

Add TIPC_NL_NET_GET command to the new tipc netlink API.

This command dumps the network id of the node.

Netlink logical layout of returned network data:
-> net
    -> id

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@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>

1 files changed, 59 insertions, 0 deletions

diff --git a/net/tipc/net.c b/net/tipc/net.c
index 93b9944a6a8b..d9e666a1be9d 100644
--- a/net/tipc/net.c
+++ b/net/tipc/net.c
@@ -42,6 +42,11 @@
 #include "node.h"
 #include "config.h"
 
+static const struct nla_policy tipc_nl_net_policy[TIPC_NLA_NET_MAX + 1] = {
+	[TIPC_NLA_NET_UNSPEC]	= { .type = NLA_UNSPEC },
+	[TIPC_NLA_NET_ID]	= { .type = NLA_U32 }
+};
+
 /*
  * The TIPC locking policy is designed to ensure a very fine locking
  * granularity, permitting complete parallel access to individual
@@ -138,3 +143,57 @@ void tipc_net_stop(void)
 
 	pr_info("Left network mode\n");
 }
+
+static int __tipc_nl_add_net(struct tipc_nl_msg *msg)
+{
+	void *hdr;
+	struct nlattr *attrs;
+
+	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_v2_family,
+			  NLM_F_MULTI, TIPC_NL_NET_GET);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	attrs = nla_nest_start(msg->skb, TIPC_NLA_NET);
+	if (!attrs)
+		goto msg_full;
+
+	if (nla_put_u32(msg->skb, TIPC_NLA_NET_ID, tipc_net_id))
+		goto attr_msg_full;
+
+	nla_nest_end(msg->skb, attrs);
+	genlmsg_end(msg->skb, hdr);
+
+	return 0;
+
+attr_msg_full:
+	nla_nest_cancel(msg->skb, attrs);
+msg_full:
+	genlmsg_cancel(msg->skb, hdr);
+
+	return -EMSGSIZE;
+}
+
+int tipc_nl_net_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	int err;
+	int done = cb->args[0];
+	struct tipc_nl_msg msg;
+
+	if (done)
+		return 0;
+
+	msg.skb = skb;
+	msg.portid = NETLINK_CB(cb->skb).portid;
+	msg.seq = cb->nlh->nlmsg_seq;
+
+	err = __tipc_nl_add_net(&msg);
+	if (err)
+		goto out;
+
+	done = 1;
+out:
+	cb->args[0] = done;
+
+	return skb->len;
+}