1 files changed, 120 insertions, 0 deletions
diff --git a/net/mptcp/diag.c b/net/mptcp/diag.c
new file mode 100644
index 000000000000..70cf9ebce833
--- /dev/null
+++ b/net/mptcp/diag.c
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0
+/* MPTCP socket monitoring support
+ *
+ * Copyright (c) 2019 Red Hat
+ *
+ * Author: Davide Caratti <dcaratti@redhat.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/net.h>
+#include <linux/inet_diag.h>
+#include <net/netlink.h>
+#include "protocol.h"
+
+static int subflow_get_info(struct sock *sk, struct sk_buff *skb, bool net_admin)
+{
+	struct mptcp_subflow_context *sf;
+	struct nlattr *start;
+	u32 flags = 0;
+	bool slow;
+	int err;
+
+	if (inet_sk_state_load(sk) == TCP_LISTEN)
+		return 0;
+
+	start = nla_nest_start_noflag(skb, INET_ULP_INFO_MPTCP);
+	if (!start)
+		return -EMSGSIZE;
+
+	slow = lock_sock_fast(sk);
+	rcu_read_lock();
+	sf = rcu_dereference(inet_csk(sk)->icsk_ulp_data);
+	if (!sf) {
+		err = 0;
+		goto nla_failure;
+	}
+
+	if (sf->mp_capable)
+		flags |= MPTCP_SUBFLOW_FLAG_MCAP_REM;
+	if (sf->request_mptcp)
+		flags |= MPTCP_SUBFLOW_FLAG_MCAP_LOC;
+	if (sf->mp_join)
+		flags |= MPTCP_SUBFLOW_FLAG_JOIN_REM;
+	if (sf->request_join)
+		flags |= MPTCP_SUBFLOW_FLAG_JOIN_LOC;
+	if (sf->backup)
+		flags |= MPTCP_SUBFLOW_FLAG_BKUP_REM;
+	if (sf->request_bkup)
+		flags |= MPTCP_SUBFLOW_FLAG_BKUP_LOC;
+	if (READ_ONCE(sf->fully_established))
+		flags |= MPTCP_SUBFLOW_FLAG_FULLY_ESTABLISHED;
+	if (sf->conn_finished)
+		flags |= MPTCP_SUBFLOW_FLAG_CONNECTED;
+	if (sf->map_valid)
+		flags |= MPTCP_SUBFLOW_FLAG_MAPVALID;
+
+	if (nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_TOKEN_REM, sf->remote_token) ||
+	    nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_TOKEN_LOC, sf->token) ||
+	    nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_FLAGS, flags) ||
+	    nla_put_u8(skb, MPTCP_SUBFLOW_ATTR_ID_REM, sf->remote_id) ||
+	    nla_put_u8(skb, MPTCP_SUBFLOW_ATTR_ID_LOC, subflow_get_local_id(sf))) {
+		err = -EMSGSIZE;
+		goto nla_failure;
+	}
+
+	/* Only export seq related counters to user with CAP_NET_ADMIN */
+	if (net_admin &&
+	    (nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_RELWRITE_SEQ,
+			 sf->rel_write_seq) ||
+	     nla_put_u64_64bit(skb, MPTCP_SUBFLOW_ATTR_MAP_SEQ, sf->map_seq,
+			       MPTCP_SUBFLOW_ATTR_PAD) ||
+	     nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_MAP_SFSEQ,
+			 sf->map_subflow_seq) ||
+	     nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_SSN_OFFSET, sf->ssn_offset) ||
+	     nla_put_u16(skb, MPTCP_SUBFLOW_ATTR_MAP_DATALEN,
+			 sf->map_data_len))) {
+		err = -EMSGSIZE;
+		goto nla_failure;
+	}
+
+	rcu_read_unlock();
+	unlock_sock_fast(sk, slow);
+	nla_nest_end(skb, start);
+	return 0;
+
+nla_failure:
+	rcu_read_unlock();
+	unlock_sock_fast(sk, slow);
+	nla_nest_cancel(skb, start);
+	return err;
+}
+
+static size_t subflow_get_info_size(const struct sock *sk, bool net_admin)
+{
+	size_t size = 0;
+
+	size += nla_total_size(0) +	/* INET_ULP_INFO_MPTCP */
+		nla_total_size(4) +	/* MPTCP_SUBFLOW_ATTR_TOKEN_REM */
+		nla_total_size(4) +	/* MPTCP_SUBFLOW_ATTR_TOKEN_LOC */
+		nla_total_size(4) +	/* MPTCP_SUBFLOW_ATTR_FLAGS */
+		nla_total_size(1) +	/* MPTCP_SUBFLOW_ATTR_ID_REM */
+		nla_total_size(1) +	/* MPTCP_SUBFLOW_ATTR_ID_LOC */
+		0;
+
+	if (net_admin)
+		size += nla_total_size(4) +	/* MPTCP_SUBFLOW_ATTR_RELWRITE_SEQ */
+			nla_total_size_64bit(8) +	/* MPTCP_SUBFLOW_ATTR_MAP_SEQ */
+			nla_total_size(4) +	/* MPTCP_SUBFLOW_ATTR_MAP_SFSEQ */
+			nla_total_size(4) +	/* MPTCP_SUBFLOW_ATTR_SSN_OFFSET */
+			nla_total_size(2) +	/* MPTCP_SUBFLOW_ATTR_MAP_DATALEN */
+			0;
+
+	return size;
+}
+
+void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops)
+{
+	ops->get_info = subflow_get_info;
+	ops->get_info_size = subflow_get_info_size;
+}