ip: expose inet sockopts through inet_diag

Expose all exisiting inet sockopt bits through inet_diag for debug purpose.
Corresponding changes in iproute2 ss will be submitted to output all
these values.

Signed-off-by: Wei Wang <[e-mail]>
Signed-off-by: Eric Dumazet <[e-mail]>
Signed-off-by: Mahesh Bandewar <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/linux/inet_diag.h

···
 #ifdef CONFIG_SOCK_CGROUP_DATA
 		+ nla_total_size_64bit(sizeof(u64))  /* INET_DIAG_CGROUP_ID */
 #endif
+		+ nla_total_size(sizeof(struct inet_diag_sockopt))
+						     /* INET_DIAG_SOCKOPT */
 		;
 }
 int inet_diag_msg_attrs_fill(struct sock *sk, struct sk_buff *skb,

include/uapi/linux/inet_diag.h

···
 	INET_DIAG_ULP_INFO,
 	INET_DIAG_SK_BPF_STORAGES,
 	INET_DIAG_CGROUP_ID,
+	INET_DIAG_SOCKOPT,
 	__INET_DIAG_MAX,
 };
 
···
 	__u32	idiag_wmem;
 	__u32	idiag_fmem;
 	__u32	idiag_tmem;
+};
+
+/* INET_DIAG_SOCKOPT */
+
+struct inet_diag_sockopt {
+	__u8	recverr:1,
+		is_icsk:1,
+		freebind:1,
+		hdrincl:1,
+		mc_loop:1,
+		transparent:1,
+		mc_all:1,
+		nodefrag:1;
+	__u8	bind_address_no_port:1,
+		recverr_rfc4884:1,
+		defer_connect:1,
+		unused:5;
 };
 
 /* INET_DIAG_VEGASINFO */

net/ipv4/inet_diag.c

···
 			     bool net_admin)
 {
 	const struct inet_sock *inet = inet_sk(sk);
+	struct inet_diag_sockopt inet_sockopt;
 
 	if (nla_put_u8(skb, INET_DIAG_SHUTDOWN, sk->sk_shutdown))
 		goto errout;
···
 
 	r->idiag_uid = from_kuid_munged(user_ns, sock_i_uid(sk));
 	r->idiag_inode = sock_i_ino(sk);
+
+	memset(&inet_sockopt, 0, sizeof(inet_sockopt));
+	inet_sockopt.recverr	= inet->recverr;
+	inet_sockopt.is_icsk	= inet->is_icsk;
+	inet_sockopt.freebind	= inet->freebind;
+	inet_sockopt.hdrincl	= inet->hdrincl;
+	inet_sockopt.mc_loop	= inet->mc_loop;
+	inet_sockopt.transparent = inet->transparent;
+	inet_sockopt.mc_all	= inet->mc_all;
+	inet_sockopt.nodefrag	= inet->nodefrag;
+	inet_sockopt.bind_address_no_port = inet->bind_address_no_port;
+	inet_sockopt.recverr_rfc4884 = inet->recverr_rfc4884;
+	inet_sockopt.defer_connect = inet->defer_connect;
+	if (nla_put(skb, INET_DIAG_SOCKOPT, sizeof(inet_sockopt),
+		    &inet_sockopt))
+		goto errout;
 
 	return 0;
 errout: