net-timestamp: namespacify the sysctl_tstamp_allow_data

Let it be tuned in per netns by admins.

Signed-off-by: Jason Xing <[e-mail]>
Reviewed-by: Kuniyuki Iwashima <[e-mail]>
Reviewed-by: Eric Dumazet <[e-mail]>
Reviewed-by: Willem de Bruijn <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

include/net/netns/core.h

···
 	int	sysctl_somaxconn;
 	int	sysctl_optmem_max;
 	u8	sysctl_txrehash;
+	u8	sysctl_tstamp_allow_data;
 
 #ifdef CONFIG_PROC_FS
 	struct prot_inuse __percpu *prot_inuse;

include/net/sock.h

···
 extern __u32 sysctl_wmem_max;
 extern __u32 sysctl_rmem_max;
 
-extern int sysctl_tstamp_allow_data;
-
 extern __u32 sysctl_wmem_default;
 extern __u32 sysctl_rmem_default;
 

net/core/net_namespace.c

···
 	 */
 	net->core.sysctl_optmem_max = 128 * 1024;
 	net->core.sysctl_txrehash = SOCK_TXREHASH_ENABLED;
+	net->core.sysctl_tstamp_allow_data = 1;
 }
 
 /* init code that must occur even if setup_net() is not called. */

net/core/skbuff.c

···
 {
 	bool ret;
 
-	if (likely(READ_ONCE(sysctl_tstamp_allow_data) || tsonly))
+	if (likely(tsonly || READ_ONCE(sock_net(sk)->core.sysctl_tstamp_allow_data)))
 		return true;
 
 	read_lock_bh(&sk->sk_callback_lock);

net/core/sock.c

···
 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
 
-int sysctl_tstamp_allow_data __read_mostly = 1;
-
 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
 EXPORT_SYMBOL_GPL(memalloc_socks_key);
 

net/core/sysctl_net_core.c

···
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
-	{
-		.procname	= "tstamp_allow_data",
-		.data		= &sysctl_tstamp_allow_data,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
-		.extra1		= SYSCTL_ZERO,
-		.extra2		= SYSCTL_ONE
-	},
 #ifdef CONFIG_RPS
 	{
 		.procname	= "rps_sock_flow_entries",
···
 		.extra1		= SYSCTL_ZERO,
 		.extra2		= SYSCTL_ONE,
 		.proc_handler	= proc_dou8vec_minmax,
+	},
+	{
+		.procname	= "tstamp_allow_data",
+		.data		= &init_net.core.sysctl_tstamp_allow_data,
+		.maxlen		= sizeof(u8),
+		.mode		= 0644,
+		.proc_handler	= proc_dou8vec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE
 	},
 	/* sysctl_core_net_init() will set the values after this
 	 * to readonly in network namespaces