1 files changed, 41 insertions, 6 deletions

diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 5490c285668b..9b8a6db7a66b 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -39,6 +39,7 @@ static u32 u32_max_div_HZ = UINT_MAX / HZ;
 static int one_day_secs = 24 * 3600;
 static u32 fib_multipath_hash_fields_all_mask __maybe_unused =
 	FIB_MULTIPATH_HASH_FIELD_ALL_MASK;
+static unsigned int tcp_child_ehash_entries_max = 16 * 1024 * 1024;
 
 /* obsolete */
 static int sysctl_tcp_low_latency __read_mostly;
@@ -382,6 +383,29 @@ static int proc_tcp_available_ulp(struct ctl_table *ctl,
 	return ret;
 }
 
+static int proc_tcp_ehash_entries(struct ctl_table *table, int write,
+				  void *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct net *net = container_of(table->data, struct net,
+				       ipv4.sysctl_tcp_child_ehash_entries);
+	struct inet_hashinfo *hinfo = net->ipv4.tcp_death_row.hashinfo;
+	int tcp_ehash_entries;
+	struct ctl_table tbl;
+
+	tcp_ehash_entries = hinfo->ehash_mask + 1;
+
+	/* A negative number indicates that the child netns
+	 * shares the global ehash.
+	 */
+	if (!net_eq(net, &init_net) && !hinfo->pernet)
+		tcp_ehash_entries *= -1;
+
+	tbl.data = &tcp_ehash_entries;
+	tbl.maxlen = sizeof(int);
+
+	return proc_dointvec(&tbl, write, buffer, lenp, ppos);
+}
+
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 static int proc_fib_multipath_hash_policy(struct ctl_table *table, int write,
 					  void *buffer, size_t *lenp,
@@ -530,10 +554,9 @@ static struct ctl_table ipv4_table[] = {
 };
 
 static struct ctl_table ipv4_net_table[] = {
-	/* tcp_max_tw_buckets must be first in this table. */
 	{
 		.procname	= "tcp_max_tw_buckets",
-/*		.data		= &init_net.ipv4.tcp_death_row.sysctl_max_tw_buckets, */
+		.data		= &init_net.ipv4.tcp_death_row.sysctl_max_tw_buckets,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec
@@ -1322,6 +1345,21 @@ static struct ctl_table ipv4_net_table[] = {
 		.extra2         = SYSCTL_ONE,
 	},
 	{
+		.procname	= "tcp_ehash_entries",
+		.data		= &init_net.ipv4.sysctl_tcp_child_ehash_entries,
+		.mode		= 0444,
+		.proc_handler	= proc_tcp_ehash_entries,
+	},
+	{
+		.procname	= "tcp_child_ehash_entries",
+		.data		= &init_net.ipv4.sysctl_tcp_child_ehash_entries,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_douintvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= &tcp_child_ehash_entries_max,
+	},
+	{
 		.procname	= "udp_rmem_min",
 		.data		= &init_net.ipv4.sysctl_udp_rmem_min,
 		.maxlen		= sizeof(init_net.ipv4.sysctl_udp_rmem_min),
@@ -1361,8 +1399,7 @@ static __net_init int ipv4_sysctl_init_net(struct net *net)
 		if (!table)
 			goto err_alloc;
 
-		/* skip first entry (sysctl_max_tw_buckets) */
-		for (i = 1; i < ARRAY_SIZE(ipv4_net_table) - 1; i++) {
+		for (i = 0; i < ARRAY_SIZE(ipv4_net_table) - 1; i++) {
 			if (table[i].data) {
 				/* Update the variables to point into
 				 * the current struct net
@@ -1377,8 +1414,6 @@ static __net_init int ipv4_sysctl_init_net(struct net *net)
 		}
 	}
 
-	table[0].data = &net->ipv4.tcp_death_row->sysctl_max_tw_buckets;
-
 	net->ipv4.ipv4_hdr = register_net_sysctl(net, "net/ipv4", table);
 	if (!net->ipv4.ipv4_hdr)
 		goto err_reg;