Merge branch 'udp-pernetns-hash'

Kuniyuki Iwashima says:

====================
udp: Introduce optional per-netns hash table.

This series is the UDP version of the per-netns ehash series [0],
which were initially in the same patch set. [1]

The notable difference with TCP is the max table size is 64K and the min
size is 128.  This is because the possible hash range by udp_hashfn()
always fits in 64K within the same netns and because we want to keep a
bitmap in udp_lib_get_port() on the stack.  Also, the UDP per-netns table
isolates both 1-tuple and 2-tuple tables.

For details, please see the last patch.

  patch 1 - 4: prep for per-netns hash table
  patch     5: add per-netns hash table

[0]: https://lore.kernel.org/netdev/20220908011022.45342-1-kuniyu@amazon.com/
[1]: https://lore.kernel.org/netdev/20220826000445.46552-1-kuniyu@amazon.com/
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/ip-sysctl.rst

@@ -1177,6 +1177,33 @@ udp_rmem_min - INTEGER
 udp_wmem_min - INTEGER
 	UDP does not have tx memory accounting and this tunable has no effect.
 
+udp_hash_entries - INTEGER
+	Show the number of hash buckets for UDP sockets in the current
+	networking namespace.
+
+	A negative value means the networking namespace does not own its
+	hash buckets and shares the initial networking namespace's one.
+
+udp_child_ehash_entries - INTEGER
+	Control the number of hash buckets for UDP sockets in the child
+	networking namespace, which must be set before clone() or unshare().
+
+	If the value is not 0, the kernel uses a value rounded up to 2^n
+	as the actual hash bucket size.  0 is a special value, meaning
+	the child networking namespace will share the initial networking
+	namespace's hash buckets.
+
+	Note that the child will use the global one in case the kernel
+	fails to allocate enough memory.  In addition, the global hash
+	buckets are spread over available NUMA nodes, but the allocation
+	of the child hash table depends on the current process's NUMA
+	policy, which could result in performance differences.
+
+	Possible values: 0, 2^n (n: 7 (128) - 16 (64K))
+
+	Default: 0
+
+
 RAW variables
 =============
 

include/linux/udp.h

@@ -23,7 +23,9 @@ static inline struct udphdr *udp_hdr(const struct sk_buff *skb)
 	return (struct udphdr *)skb_transport_header(skb);
 }
 
+#define UDP_HTABLE_SIZE_MIN_PERNET	128
 #define UDP_HTABLE_SIZE_MIN		(CONFIG_BASE_SMALL ? 128 : 256)
+#define UDP_HTABLE_SIZE_MAX		65536
 
 static inline u32 udp_hashfn(const struct net *net, u32 num, u32 mask)
 {

include/net/netns/ipv4.h

@@ -43,6 +43,7 @@ struct tcp_fastopen_context;
 
 struct netns_ipv4 {
 	struct inet_timewait_death_row tcp_death_row;
+	struct udp_table *udp_table;
 
 #ifdef CONFIG_SYSCTL
 	struct ctl_table_header	*forw_hdr;
@@ -207,6 +208,8 @@ struct netns_ipv4 {
 
 	atomic_t dev_addr_genid;
 
+	unsigned int sysctl_udp_child_hash_entries;
+
 #ifdef CONFIG_SYSCTL
 	unsigned long *sysctl_local_reserved_ports;
 	int sysctl_ip_prot_sock;

net/core/filter.c

@@ -6432,7 +6432,7 @@ static struct sock *sk_lookup(struct net *net, struct bpf_sock_tuple *tuple,
 		else
 			sk = __udp4_lib_lookup(net, src4, tuple->ipv4.sport,
 					       dst4, tuple->ipv4.dport,
-					       dif, sdif, &udp_table, NULL);
+					       dif, sdif, net->ipv4.udp_table, NULL);
 #if IS_ENABLED(CONFIG_IPV6)
 	} else {
 		struct in6_addr *src6 = (struct in6_addr *)&tuple->ipv6.saddr;
@@ -6448,7 +6448,7 @@ static struct sock *sk_lookup(struct net *net, struct bpf_sock_tuple *tuple,
 							    src6, tuple->ipv6.sport,
 							    dst6, tuple->ipv6.dport,
 							    dif, sdif,
-							    &udp_table, NULL);
+							    net->ipv4.udp_table, NULL);
 #endif
 	}
 

net/ipv4/sysctl_net_ipv4.c

@@ -40,6 +40,7 @@ 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;
+static unsigned int udp_child_hash_entries_max = UDP_HTABLE_SIZE_MAX;
 static int tcp_plb_max_rounds = 31;
 static int tcp_plb_max_cong_thresh = 256;
 
@@ -402,12 +403,36 @@ static int proc_tcp_ehash_entries(struct ctl_table *table, int write,
 	if (!net_eq(net, &init_net) && !hinfo->pernet)
 		tcp_ehash_entries *= -1;
 
+	memset(&tbl, 0, sizeof(tbl));
 	tbl.data = &tcp_ehash_entries;
 	tbl.maxlen = sizeof(int);
 
 	return proc_dointvec(&tbl, write, buffer, lenp, ppos);
 }
 
+static int proc_udp_hash_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_udp_child_hash_entries);
+	int udp_hash_entries;
+	struct ctl_table tbl;
+
+	udp_hash_entries = net->ipv4.udp_table->mask + 1;
+
+	/* A negative number indicates that the child netns
+	 * shares the global udp_table.
+	 */
+	if (!net_eq(net, &init_net) && net->ipv4.udp_table == &udp_table)
+		udp_hash_entries *= -1;
+
+	memset(&tbl, 0, sizeof(tbl));
+	tbl.data = &udp_hash_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,
@@ -1361,6 +1386,21 @@ static struct ctl_table ipv4_net_table[] = {
 		.extra1		= SYSCTL_ZERO,
 		.extra2		= &tcp_child_ehash_entries_max,
 	},
+	{
+		.procname	= "udp_hash_entries",
+		.data		= &init_net.ipv4.sysctl_udp_child_hash_entries,
+		.mode		= 0444,
+		.proc_handler	= proc_udp_hash_entries,
+	},
+	{
+		.procname	= "udp_child_hash_entries",
+		.data		= &init_net.ipv4.sysctl_udp_child_hash_entries,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_douintvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= &udp_child_hash_entries_max,
+	},
 	{
 		.procname	= "udp_rmem_min",
 		.data		= &init_net.ipv4.sysctl_udp_rmem_min,

net/ipv4/udp.c

@@ -129,7 +129,12 @@ DEFINE_PER_CPU(int, udp_memory_per_cpu_fw_alloc);
 EXPORT_PER_CPU_SYMBOL_GPL(udp_memory_per_cpu_fw_alloc);
 
 #define MAX_UDP_PORTS 65536
-#define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
+#define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN_PERNET)
+
+static struct udp_table *udp_get_table_prot(struct sock *sk)
+{
+	return sk->sk_prot->h.udp_table ? : sock_net(sk)->ipv4.udp_table;
+}
 
 static int udp_lib_lport_inuse(struct net *net, __u16 num,
 			       const struct udp_hslot *hslot,
@@ -232,16 +237,16 @@ static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot)
 int udp_lib_get_port(struct sock *sk, unsigned short snum,
 		     unsigned int hash2_nulladdr)
 {
+	struct udp_table *udptable = udp_get_table_prot(sk);
 	struct udp_hslot *hslot, *hslot2;
-	struct udp_table *udptable = sk->sk_prot->h.udp_table;
-	int    error = 1;
 	struct net *net = sock_net(sk);
+	int error = 1;
 
 	if (!snum) {
+		DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
+		unsigned short first, last;
 		int low, high, remaining;
 		unsigned int rand;
-		unsigned short first, last;
-		DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
 
 		inet_get_local_port_range(net, &low, &high);
 		remaining = (high - low) + 1;
@@ -467,7 +472,7 @@ static struct sock *udp4_lookup_run_bpf(struct net *net,
 	struct sock *sk, *reuse_sk;
 	bool no_reuseport;
 
-	if (udptable != &udp_table)
+	if (udptable != net->ipv4.udp_table)
 		return NULL; /* only UDP is supported */
 
 	no_reuseport = bpf_sk_lookup_run_v4(net, IPPROTO_UDP, saddr, sport,
@@ -548,10 +553,11 @@ struct sock *udp4_lib_lookup_skb(const struct sk_buff *skb,
 				 __be16 sport, __be16 dport)
 {
 	const struct iphdr *iph = ip_hdr(skb);
+	struct net *net = dev_net(skb->dev);
 
-	return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
+	return __udp4_lib_lookup(net, iph->saddr, sport,
 				 iph->daddr, dport, inet_iif(skb),
-				 inet_sdif(skb), &udp_table, NULL);
+				 inet_sdif(skb), net->ipv4.udp_table, NULL);
 }
 
 /* Must be called under rcu_read_lock().
@@ -564,7 +570,7 @@ struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
 	struct sock *sk;
 
 	sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport,
-			       dif, 0, &udp_table, NULL);
+			       dif, 0, net->ipv4.udp_table, NULL);
 	if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
 		sk = NULL;
 	return sk;
@@ -802,7 +808,7 @@ int __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
 
 int udp_err(struct sk_buff *skb, u32 info)
 {
-	return __udp4_lib_err(skb, info, &udp_table);
+	return __udp4_lib_err(skb, info, dev_net(skb->dev)->ipv4.udp_table);
 }
 
 /*
@@ -1999,7 +2005,7 @@ EXPORT_SYMBOL(udp_disconnect);
 void udp_lib_unhash(struct sock *sk)
 {
 	if (sk_hashed(sk)) {
-		struct udp_table *udptable = sk->sk_prot->h.udp_table;
+		struct udp_table *udptable = udp_get_table_prot(sk);
 		struct udp_hslot *hslot, *hslot2;
 
 		hslot  = udp_hashslot(udptable, sock_net(sk),
@@ -2030,7 +2036,7 @@ EXPORT_SYMBOL(udp_lib_unhash);
 void udp_lib_rehash(struct sock *sk, u16 newhash)
 {
 	if (sk_hashed(sk)) {
-		struct udp_table *udptable = sk->sk_prot->h.udp_table;
+		struct udp_table *udptable = udp_get_table_prot(sk);
 		struct udp_hslot *hslot, *hslot2, *nhslot2;
 
 		hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
@@ -2519,10 +2525,14 @@ static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
 						  __be16 rmt_port, __be32 rmt_addr,
 						  int dif, int sdif)
 {
-	struct sock *sk, *result;
+	struct udp_table *udptable = net->ipv4.udp_table;
 	unsigned short hnum = ntohs(loc_port);
-	unsigned int slot = udp_hashfn(net, hnum, udp_table.mask);
-	struct udp_hslot *hslot = &udp_table.hash[slot];
+	struct sock *sk, *result;
+	struct udp_hslot *hslot;
+	unsigned int slot;
+
+	slot = udp_hashfn(net, hnum, udptable->mask);
+	hslot = &udptable->hash[slot];
 
 	/* Do not bother scanning a too big list */
 	if (hslot->count > 10)
@@ -2550,14 +2560,19 @@ static struct sock *__udp4_lib_demux_lookup(struct net *net,
 					    __be16 rmt_port, __be32 rmt_addr,
 					    int dif, int sdif)
 {
-	unsigned short hnum = ntohs(loc_port);
-	unsigned int hash2 = ipv4_portaddr_hash(net, loc_addr, hnum);
-	unsigned int slot2 = hash2 & udp_table.mask;
-	struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
+	struct udp_table *udptable = net->ipv4.udp_table;
 	INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
-	const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
+	unsigned short hnum = ntohs(loc_port);
+	unsigned int hash2, slot2;
+	struct udp_hslot *hslot2;
+	__portpair ports;
 	struct sock *sk;
 
+	hash2 = ipv4_portaddr_hash(net, loc_addr, hnum);
+	slot2 = hash2 & udptable->mask;
+	hslot2 = &udptable->hash2[slot2];
+	ports = INET_COMBINED_PORTS(rmt_port, hnum);
+
 	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
 		if (inet_match(net, sk, acookie, ports, dif, sdif))
 			return sk;
@@ -2637,7 +2652,7 @@ int udp_v4_early_demux(struct sk_buff *skb)
 
 int udp_rcv(struct sk_buff *skb)
 {
-	return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
+	return __udp4_lib_rcv(skb, dev_net(skb->dev)->ipv4.udp_table, IPPROTO_UDP);
 }
 
 void udp_destroy_sock(struct sock *sk)
@@ -2960,7 +2975,7 @@ struct proto udp_prot = {
 	.sysctl_wmem_offset	= offsetof(struct net, ipv4.sysctl_udp_wmem_min),
 	.sysctl_rmem_offset	= offsetof(struct net, ipv4.sysctl_udp_rmem_min),
 	.obj_size		= sizeof(struct udp_sock),
-	.h.udp_table		= &udp_table,
+	.h.udp_table		= NULL,
 	.diag_destroy		= udp_abort,
 };
 EXPORT_SYMBOL(udp_prot);
@@ -2968,21 +2983,30 @@ EXPORT_SYMBOL(udp_prot);
 /* ------------------------------------------------------------------------ */
 #ifdef CONFIG_PROC_FS
 
+static struct udp_table *udp_get_table_afinfo(struct udp_seq_afinfo *afinfo,
+					      struct net *net)
+{
+	return afinfo->udp_table ? : net->ipv4.udp_table;
+}
+
 static struct sock *udp_get_first(struct seq_file *seq, int start)
 {
-	struct sock *sk;
-	struct udp_seq_afinfo *afinfo;
 	struct udp_iter_state *state = seq->private;
 	struct net *net = seq_file_net(seq);
+	struct udp_seq_afinfo *afinfo;
+	struct udp_table *udptable;
+	struct sock *sk;
 
 	if (state->bpf_seq_afinfo)
 		afinfo = state->bpf_seq_afinfo;
 	else
 		afinfo = pde_data(file_inode(seq->file));
 
-	for (state->bucket = start; state->bucket <= afinfo->udp_table->mask;
+	udptable = udp_get_table_afinfo(afinfo, net);
+
+	for (state->bucket = start; state->bucket <= udptable->mask;
 	     ++state->bucket) {
-		struct udp_hslot *hslot = &afinfo->udp_table->hash[state->bucket];
+		struct udp_hslot *hslot = &udptable->hash[state->bucket];
 
 		if (hlist_empty(&hslot->head))
 			continue;
@@ -3004,9 +3028,10 @@ static struct sock *udp_get_first(struct seq_file *seq, int start)
 
 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
 {
-	struct udp_seq_afinfo *afinfo;
 	struct udp_iter_state *state = seq->private;
 	struct net *net = seq_file_net(seq);
+	struct udp_seq_afinfo *afinfo;
+	struct udp_table *udptable;
 
 	if (state->bpf_seq_afinfo)
 		afinfo = state->bpf_seq_afinfo;
@@ -3020,8 +3045,11 @@ static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
 			 sk->sk_family != afinfo->family)));
 
 	if (!sk) {
-		if (state->bucket <= afinfo->udp_table->mask)
-			spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock);
+		udptable = udp_get_table_afinfo(afinfo, net);
+
+		if (state->bucket <= udptable->mask)
+			spin_unlock_bh(&udptable->hash[state->bucket].lock);
+
 		return udp_get_first(seq, state->bucket + 1);
 	}
 	return sk;
@@ -3062,16 +3090,19 @@ EXPORT_SYMBOL(udp_seq_next);
 
 void udp_seq_stop(struct seq_file *seq, void *v)
 {
-	struct udp_seq_afinfo *afinfo;
 	struct udp_iter_state *state = seq->private;
+	struct udp_seq_afinfo *afinfo;
+	struct udp_table *udptable;
 
 	if (state->bpf_seq_afinfo)
 		afinfo = state->bpf_seq_afinfo;
 	else
 		afinfo = pde_data(file_inode(seq->file));
 
-	if (state->bucket <= afinfo->udp_table->mask)
-		spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock);
+	udptable = udp_get_table_afinfo(afinfo, seq_file_net(seq));
+
+	if (state->bucket <= udptable->mask)
+		spin_unlock_bh(&udptable->hash[state->bucket].lock);
 }
 EXPORT_SYMBOL(udp_seq_stop);
 
@@ -3184,7 +3215,7 @@ EXPORT_SYMBOL(udp_seq_ops);
 
 static struct udp_seq_afinfo udp4_seq_afinfo = {
 	.family		= AF_INET,
-	.udp_table	= &udp_table,
+	.udp_table	= NULL,
 };
 
 static int __net_init udp4_proc_init_net(struct net *net)
@@ -3246,7 +3277,7 @@ void __init udp_table_init(struct udp_table *table, const char *name)
 					      &table->log,
 					      &table->mask,
 					      UDP_HTABLE_SIZE_MIN,
-					      64 * 1024);
+					      UDP_HTABLE_SIZE_MAX);
 
 	table->hash2 = table->hash + (table->mask + 1);
 	for (i = 0; i <= table->mask; i++) {
@@ -3271,7 +3302,7 @@ u32 udp_flow_hashrnd(void)
 }
 EXPORT_SYMBOL(udp_flow_hashrnd);
 
-static int __net_init udp_sysctl_init(struct net *net)
+static void __net_init udp_sysctl_init(struct net *net)
 {
 	net->ipv4.sysctl_udp_rmem_min = PAGE_SIZE;
 	net->ipv4.sysctl_udp_wmem_min = PAGE_SIZE;
@@ -3279,12 +3310,103 @@ static int __net_init udp_sysctl_init(struct net *net)
 #ifdef CONFIG_NET_L3_MASTER_DEV
 	net->ipv4.sysctl_udp_l3mdev_accept = 0;
 #endif
+}
+
+static struct udp_table __net_init *udp_pernet_table_alloc(unsigned int hash_entries)
+{
+	struct udp_table *udptable;
+	int i;
+
+	udptable = kmalloc(sizeof(*udptable), GFP_KERNEL);
+	if (!udptable)
+		goto out;
+
+	udptable->hash = vmalloc_huge(hash_entries * 2 * sizeof(struct udp_hslot),
+				      GFP_KERNEL_ACCOUNT);
+	if (!udptable->hash)
+		goto free_table;
+
+	udptable->hash2 = udptable->hash + hash_entries;
+	udptable->mask = hash_entries - 1;
+	udptable->log = ilog2(hash_entries);
+
+	for (i = 0; i < hash_entries; i++) {
+		INIT_HLIST_HEAD(&udptable->hash[i].head);
+		udptable->hash[i].count = 0;
+		spin_lock_init(&udptable->hash[i].lock);
+
+		INIT_HLIST_HEAD(&udptable->hash2[i].head);
+		udptable->hash2[i].count = 0;
+		spin_lock_init(&udptable->hash2[i].lock);
+	}
+
+	return udptable;
+
+free_table:
+	kfree(udptable);
+out:
+	return NULL;
+}
+
+static void __net_exit udp_pernet_table_free(struct net *net)
+{
+	struct udp_table *udptable = net->ipv4.udp_table;
+
+	if (udptable == &udp_table)
+		return;
+
+	kvfree(udptable->hash);
+	kfree(udptable);
+}
+
+static void __net_init udp_set_table(struct net *net)
+{
+	struct udp_table *udptable;
+	unsigned int hash_entries;
+	struct net *old_net;
+
+	if (net_eq(net, &init_net))
+		goto fallback;
+
+	old_net = current->nsproxy->net_ns;
+	hash_entries = READ_ONCE(old_net->ipv4.sysctl_udp_child_hash_entries);
+	if (!hash_entries)
+		goto fallback;
+
+	/* Set min to keep the bitmap on stack in udp_lib_get_port() */
+	if (hash_entries < UDP_HTABLE_SIZE_MIN_PERNET)
+		hash_entries = UDP_HTABLE_SIZE_MIN_PERNET;
+	else
+		hash_entries = roundup_pow_of_two(hash_entries);
+
+	udptable = udp_pernet_table_alloc(hash_entries);
+	if (udptable) {
+		net->ipv4.udp_table = udptable;
+	} else {
+		pr_warn("Failed to allocate UDP hash table (entries: %u) "
+			"for a netns, fallback to the global one\n",
+			hash_entries);
+fallback:
+		net->ipv4.udp_table = &udp_table;
+	}
+}
+
+static int __net_init udp_pernet_init(struct net *net)
+{
+	udp_sysctl_init(net);
+	udp_set_table(net);
 
 	return 0;
 }
 
+static void __net_exit udp_pernet_exit(struct net *net)
+{
+	udp_pernet_table_free(net);
+}
+
 static struct pernet_operations __net_initdata udp_sysctl_ops = {
-	.init	= udp_sysctl_init,
+	.init	= udp_pernet_init,
+	.exit	= udp_pernet_exit,
 };
 
 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
@@ -3302,7 +3424,7 @@ static int bpf_iter_init_udp(void *priv_data, struct bpf_iter_aux_info *aux)
 		return -ENOMEM;
 
 	afinfo->family = AF_UNSPEC;
-	afinfo->udp_table = &udp_table;
+	afinfo->udp_table = NULL;
 	st->bpf_seq_afinfo = afinfo;
 	ret = bpf_iter_init_seq_net(priv_data, aux);
 	if (ret)

net/ipv4/udp_diag.c

@@ -147,13 +147,13 @@ static void udp_dump(struct udp_table *table, struct sk_buff *skb,
 static void udp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 			  const struct inet_diag_req_v2 *r)
 {
-	udp_dump(&udp_table, skb, cb, r);
+	udp_dump(sock_net(cb->skb->sk)->ipv4.udp_table, skb, cb, r);
 }
 
 static int udp_diag_dump_one(struct netlink_callback *cb,
 			     const struct inet_diag_req_v2 *req)
 {
-	return udp_dump_one(&udp_table, cb, req);
+	return udp_dump_one(sock_net(cb->skb->sk)->ipv4.udp_table, cb, req);
 }
 
 static void udp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
@@ -225,7 +225,7 @@ static int __udp_diag_destroy(struct sk_buff *in_skb,
 static int udp_diag_destroy(struct sk_buff *in_skb,
 			    const struct inet_diag_req_v2 *req)
 {
-	return __udp_diag_destroy(in_skb, req, &udp_table);
+	return __udp_diag_destroy(in_skb, req, sock_net(in_skb->sk)->ipv4.udp_table);
 }
 
 static int udplite_diag_destroy(struct sk_buff *in_skb,

net/ipv4/udp_offload.c

@@ -600,10 +600,11 @@ static struct sock *udp4_gro_lookup_skb(struct sk_buff *skb, __be16 sport,
 					__be16 dport)
 {
 	const struct iphdr *iph = skb_gro_network_header(skb);
+	struct net *net = dev_net(skb->dev);
 
-	return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
+	return __udp4_lib_lookup(net, iph->saddr, sport,
 				 iph->daddr, dport, inet_iif(skb),
-				 inet_sdif(skb), &udp_table, NULL);
+				 inet_sdif(skb), net->ipv4.udp_table, NULL);
 }
 
 INDIRECT_CALLABLE_SCOPE

net/ipv6/udp.c

@@ -217,7 +217,7 @@ static inline struct sock *udp6_lookup_run_bpf(struct net *net,
 	struct sock *sk, *reuse_sk;
 	bool no_reuseport;
 
-	if (udptable != &udp_table)
+	if (udptable != net->ipv4.udp_table)
 		return NULL; /* only UDP is supported */
 
 	no_reuseport = bpf_sk_lookup_run_v6(net, IPPROTO_UDP, saddr, sport,
@@ -298,10 +298,11 @@ struct sock *udp6_lib_lookup_skb(const struct sk_buff *skb,
 				 __be16 sport, __be16 dport)
 {
 	const struct ipv6hdr *iph = ipv6_hdr(skb);
+	struct net *net = dev_net(skb->dev);
 
-	return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
+	return __udp6_lib_lookup(net, &iph->saddr, sport,
 				 &iph->daddr, dport, inet6_iif(skb),
-				 inet6_sdif(skb), &udp_table, NULL);
+				 inet6_sdif(skb), net->ipv4.udp_table, NULL);
 }
 
 /* Must be called under rcu_read_lock().
@@ -314,7 +315,7 @@ struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be
 	struct sock *sk;
 
 	sk =  __udp6_lib_lookup(net, saddr, sport, daddr, dport,
-				dif, 0, &udp_table, NULL);
+				dif, 0, net->ipv4.udp_table, NULL);
 	if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
 		sk = NULL;
 	return sk;
@@ -689,7 +690,8 @@ static __inline__ int udpv6_err(struct sk_buff *skb,
 				struct inet6_skb_parm *opt, u8 type,
 				u8 code, int offset, __be32 info)
 {
-	return __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
+	return __udp6_lib_err(skb, opt, type, code, offset, info,
+			      dev_net(skb->dev)->ipv4.udp_table);
 }
 
 static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
@@ -1063,13 +1065,18 @@ static struct sock *__udp6_lib_demux_lookup(struct net *net,
 			__be16 rmt_port, const struct in6_addr *rmt_addr,
 			int dif, int sdif)
 {
+	struct udp_table *udptable = net->ipv4.udp_table;
 	unsigned short hnum = ntohs(loc_port);
-	unsigned int hash2 = ipv6_portaddr_hash(net, loc_addr, hnum);
-	unsigned int slot2 = hash2 & udp_table.mask;
-	struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
-	const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
+	unsigned int hash2, slot2;
+	struct udp_hslot *hslot2;
+	__portpair ports;
 	struct sock *sk;
 
+	hash2 = ipv6_portaddr_hash(net, loc_addr, hnum);
+	slot2 = hash2 & udptable->mask;
+	hslot2 = &udptable->hash2[slot2];
+	ports = INET_COMBINED_PORTS(rmt_port, hnum);
+
 	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
 		if (sk->sk_state == TCP_ESTABLISHED &&
 		    inet6_match(net, sk, rmt_addr, loc_addr, ports, dif, sdif))
@@ -1123,7 +1130,7 @@ void udp_v6_early_demux(struct sk_buff *skb)
 
 INDIRECT_CALLABLE_SCOPE int udpv6_rcv(struct sk_buff *skb)
 {
-	return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
+	return __udp6_lib_rcv(skb, dev_net(skb->dev)->ipv4.udp_table, IPPROTO_UDP);
 }
 
 /*
@@ -1720,7 +1727,7 @@ EXPORT_SYMBOL(udp6_seq_ops);
 
 static struct udp_seq_afinfo udp6_seq_afinfo = {
 	.family		= AF_INET6,
-	.udp_table	= &udp_table,
+	.udp_table	= NULL,
 };
 
 int __net_init udp6_proc_init(struct net *net)
@@ -1770,7 +1777,7 @@ struct proto udpv6_prot = {
 	.sysctl_wmem_offset     = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
 	.sysctl_rmem_offset     = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
 	.obj_size		= sizeof(struct udp6_sock),
-	.h.udp_table		= &udp_table,
+	.h.udp_table		= NULL,
 	.diag_destroy		= udp_abort,
 };
 

net/ipv6/udp_offload.c

@@ -116,10 +116,11 @@ static struct sock *udp6_gro_lookup_skb(struct sk_buff *skb, __be16 sport,
 					__be16 dport)
 {
 	const struct ipv6hdr *iph = skb_gro_network_header(skb);
+	struct net *net = dev_net(skb->dev);
 
-	return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
+	return __udp6_lib_lookup(net, &iph->saddr, sport,
 				 &iph->daddr, dport, inet6_iif(skb),
-				 inet6_sdif(skb), &udp_table, NULL);
+				 inet6_sdif(skb), net->ipv4.udp_table, NULL);
 }
 
 INDIRECT_CALLABLE_SCOPE