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;
+}