tipc: set sysctl_tipc_rmem and named_timeout right range

We find that sysctl_tipc_rmem and named_timeout do not have the right minimum
setting. sysctl_tipc_rmem should be larger than zero, like sysctl_tcp_rmem.
And named_timeout as a timeout setting should be not less than zero.

Fixes: cc79dd1b ("tipc: change socket buffer overflow control to respect sk_rcvbuf")
Fixes: a5325ae5 ("tipc: add name distributor resiliency queue")
Signed-off-by: Jie Liu <liujie165@huawei.com>
Reported-by: Qiang Ning <ningqiang1@huawei.com>
Reviewed-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/sysctl.c

@@ -38,6 +38,8 @@
 
 #include <linux/sysctl.h>
 
+static int zero;
+static int one = 1;
 static struct ctl_table_header *tipc_ctl_hdr;
 
 static struct ctl_table tipc_table[] = {
@@ -46,14 +48,16 @@ static struct ctl_table tipc_table[] = {
 		.data		= &sysctl_tipc_rmem,
 		.maxlen		= sizeof(sysctl_tipc_rmem),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1         = &one,
 	},
 	{
 		.procname	= "named_timeout",
 		.data		= &sysctl_tipc_named_timeout,
 		.maxlen		= sizeof(sysctl_tipc_named_timeout),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1         = &zero,
 	},
 	{
 		.procname       = "sk_filter",