tipc: add sock dump to new netlink api

Add TIPC_NL_SOCK_GET command to the new tipc netlink API.

This command supports dumping of all available sockets with their
associated connection or publication(s). It could be extended to reply
with a single socket if the NLM_F_DUMP isn't set.

The information about a socket includes reference, address, connection
information / publication information.

Netlink logical layout of response message:
-> socket
    -> reference
    -> address
    [
    -> connection
        -> node
        -> socket
        [
        -> connected flag
        -> type
        -> instance
        ]
    ]
    [
    -> publication flag
    ]

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, 101 insertions, 0 deletions

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 591bbfa082a0..9e95c1ea5564 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -2801,3 +2801,104 @@ void tipc_socket_stop(void)
         sock_unregister(tipc_family_ops.family);
         proto_unregister(&tipc_proto);
 }
+
+/* Caller should hold socket lock for the passed tipc socket. */
+int __tipc_nl_add_sk_con(struct sk_buff *skb, struct tipc_sock *tsk)
+{
+        u32 peer_node;
+        u32 peer_port;
+        struct nlattr *nest;
+
+        peer_node = tsk_peer_node(tsk);
+        peer_port = tsk_peer_port(tsk);
+
+        nest = nla_nest_start(skb, TIPC_NLA_SOCK_CON);
+
+        if (nla_put_u32(skb, TIPC_NLA_CON_NODE, peer_node))
+                goto msg_full;
+        if (nla_put_u32(skb, TIPC_NLA_CON_SOCK, peer_port))
+                goto msg_full;
+
+        if (tsk->conn_type != 0) {
+                if (nla_put_flag(skb, TIPC_NLA_CON_FLAG))
+                        goto msg_full;
+                if (nla_put_u32(skb, TIPC_NLA_CON_TYPE, tsk->conn_type))
+                        goto msg_full;
+                if (nla_put_u32(skb, TIPC_NLA_CON_INST, tsk->conn_instance))
+                        goto msg_full;
+        }
+        nla_nest_end(skb, nest);
+
+        return 0;
+
+msg_full:
+        nla_nest_cancel(skb, nest);
+
+        return -EMSGSIZE;
+}
+
+/* Caller should hold socket lock for the passed tipc socket. */
+int __tipc_nl_add_sk(struct sk_buff *skb, struct netlink_callback *cb,
+                     struct tipc_sock *tsk)
+{
+        int err;
+        void *hdr;
+        struct nlattr *attrs;
+
+        hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
+                          &tipc_genl_v2_family, NLM_F_MULTI, TIPC_NL_SOCK_GET);
+        if (!hdr)
+                goto msg_cancel;
+
+        attrs = nla_nest_start(skb, TIPC_NLA_SOCK);
+        if (!attrs)
+                goto genlmsg_cancel;
+        if (nla_put_u32(skb, TIPC_NLA_SOCK_REF, tsk->ref))
+                goto attr_msg_cancel;
+        if (nla_put_u32(skb, TIPC_NLA_SOCK_ADDR, tipc_own_addr))
+                goto attr_msg_cancel;
+
+        if (tsk->connected) {
+                err = __tipc_nl_add_sk_con(skb, tsk);
+                if (err)
+                        goto attr_msg_cancel;
+        } else if (!list_empty(&tsk->publications)) {
+                if (nla_put_flag(skb, TIPC_NLA_SOCK_HAS_PUBL))
+                        goto attr_msg_cancel;
+        }
+        nla_nest_end(skb, attrs);
+        genlmsg_end(skb, hdr);
+
+        return 0;
+
+attr_msg_cancel:
+        nla_nest_cancel(skb, attrs);
+genlmsg_cancel:
+        genlmsg_cancel(skb, hdr);
+msg_cancel:
+        return -EMSGSIZE;
+}
+
+int tipc_nl_sk_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+        int err;
+        struct tipc_sock *tsk;
+        u32 prev_ref = cb->args[0];
+        u32 ref = prev_ref;
+
+        tsk = tipc_sk_get_next(&ref);
+        for (; tsk; tsk = tipc_sk_get_next(&ref)) {
+                lock_sock(&tsk->sk);
+                err = __tipc_nl_add_sk(skb, cb, tsk);
+                release_sock(&tsk->sk);
+                tipc_sk_put(tsk);
+                if (err)
+                        break;
+
+                prev_ref = ref;
+        }
+
+        cb->args[0] = prev_ref;
+
+        return skb->len;
+}