igmp: Namespaceify igmp_max_memberships sysctl knob

Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/igmp.h

@@ -38,7 +38,6 @@ static inline struct igmpv3_query *
 }
 
 extern int sysctl_igmp_llm_reports;
-extern int sysctl_igmp_max_memberships;
 extern int sysctl_igmp_max_msf;
 extern int sysctl_igmp_qrv;
 

include/net/netns/ipv4.h

@@ -108,6 +108,8 @@ struct netns_ipv4 {
 	int sysctl_tcp_fin_timeout;
 	unsigned int sysctl_tcp_notsent_lowat;
 
+	int sysctl_igmp_max_memberships;
+
 	struct ping_group_range ping_group_range;
 
 	atomic_t dev_addr_genid;

net/ipv4/igmp.c

@@ -107,7 +107,6 @@
 #include <linux/seq_file.h>
 #endif
 
-#define IP_MAX_MEMBERSHIPS	20
 #define IP_MAX_MSF		10
 
 /* IGMP reports for link-local multicast groups are enabled by default */
@@ -1727,7 +1726,6 @@ static struct in_device *ip_mc_find_dev(struct net *net, struct ip_mreqn *imr)
 /*
  *	Join a socket to a group
  */
-int sysctl_igmp_max_memberships __read_mostly = IP_MAX_MEMBERSHIPS;
 int sysctl_igmp_max_msf __read_mostly = IP_MAX_MSF;
 #ifdef CONFIG_IP_MULTICAST
 int sysctl_igmp_qrv __read_mostly = IGMP_QUERY_ROBUSTNESS_VARIABLE;
@@ -2074,7 +2072,7 @@ int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr)
 		count++;
 	}
 	err = -ENOBUFS;
-	if (count >= sysctl_igmp_max_memberships)
+	if (count >= net->ipv4.sysctl_igmp_max_memberships)
 		goto done;
 	iml = sock_kmalloc(sk, sizeof(*iml), GFP_KERNEL);
 	if (!iml)

net/ipv4/sysctl_net_ipv4.c

@@ -367,13 +367,6 @@ static struct ctl_table ipv4_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec
 	},
-	{
-		.procname	= "igmp_max_memberships",
-		.data		= &sysctl_igmp_max_memberships,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec
-	},
 	{
 		.procname	= "igmp_max_msf",
 		.data		= &sysctl_igmp_max_msf,
@@ -871,6 +864,13 @@ static struct ctl_table ipv4_net_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec
 	},
+	{
+		.procname	= "igmp_max_memberships",
+		.data		= &init_net.ipv4.sysctl_igmp_max_memberships,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec
+	},
 	{
 		.procname	= "tcp_keepalive_time",
 		.data		= &init_net.ipv4.sysctl_tcp_keepalive_time,

net/ipv4/tcp_ipv4.c

@@ -2399,6 +2399,8 @@ static int __net_init tcp_sk_init(struct net *net)
 	net->ipv4.sysctl_tcp_fin_timeout = TCP_FIN_TIMEOUT;
 	net->ipv4.sysctl_tcp_notsent_lowat = UINT_MAX;
 
+	net->ipv4.sysctl_igmp_max_memberships = 20;
+
 	return 0;
 fail:
 	tcp_sk_exit(net);