Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2019-01-29

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Teach verifier dead code removal, this also allows for optimizing /
   removing conditional branches around dead code and to shrink the
   resulting image. Code store constrained architectures like nfp would
   have hard time doing this at JIT level, from Jakub.

2) Add JMP32 instructions to BPF ISA in order to allow for optimizing
   code generation for 32-bit sub-registers. Evaluation shows that this
   can result in code reduction of ~5-20% compared to 64 bit-only code
   generation. Also add implementation for most JITs, from Jiong.

3) Add support for __int128 types in BTF which is also needed for
   vmlinux's BTF conversion to work, from Yonghong.

4) Add a new command to bpftool in order to dump a list of BPF-related
   parameters from the system or for a specific network device e.g. in
   terms of available prog/map types or helper functions, from Quentin.

5) Add AF_XDP sock_diag interface for querying sockets from user
   space which provides information about the RX/TX/fill/completion
   rings, umem, memory usage etc, from Björn.

6) Add skb context access for skb_shared_info->gso_segs field, from Eric.

7) Add support for testing flow dissector BPF programs by extending
   existing BPF_PROG_TEST_RUN infrastructure, from Stanislav.

8) Split BPF kselftest's test_verifier into various subgroups of tests
   in order better deal with merge conflicts in this area, from Jakub.

9) Add support for queue/stack manipulations in bpftool, from Stanislav.

10) Document BTF, from Yonghong.

11) Dump supported ELF section names in libbpf on program load
    failure, from Taeung.

12) Silence a false positive compiler warning in verifier's BTF
    handling, from Peter.

13) Fix help string in bpftool's feature probing, from Prashant.

14) Remove duplicate includes in BPF kselftests, from Yue.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

9 files changed, 414 insertions, 43 deletions

diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index fa2644d276ef..2c5172b33209 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -240,3 +240,85 @@ out:
 	kfree(data);
 	return ret;
 }
+
+int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
+				     const union bpf_attr *kattr,
+				     union bpf_attr __user *uattr)
+{
+	u32 size = kattr->test.data_size_in;
+	u32 repeat = kattr->test.repeat;
+	struct bpf_flow_keys flow_keys;
+	u64 time_start, time_spent = 0;
+	struct bpf_skb_data_end *cb;
+	u32 retval, duration;
+	struct sk_buff *skb;
+	struct sock *sk;
+	void *data;
+	int ret;
+	u32 i;
+
+	if (prog->type != BPF_PROG_TYPE_FLOW_DISSECTOR)
+		return -EINVAL;
+
+	data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,
+			     SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	sk = kzalloc(sizeof(*sk), GFP_USER);
+	if (!sk) {
+		kfree(data);
+		return -ENOMEM;
+	}
+	sock_net_set(sk, current->nsproxy->net_ns);
+	sock_init_data(NULL, sk);
+
+	skb = build_skb(data, 0);
+	if (!skb) {
+		kfree(data);
+		kfree(sk);
+		return -ENOMEM;
+	}
+	skb->sk = sk;
+
+	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
+	__skb_put(skb, size);
+	skb->protocol = eth_type_trans(skb,
+				       current->nsproxy->net_ns->loopback_dev);
+	skb_reset_network_header(skb);
+
+	cb = (struct bpf_skb_data_end *)skb->cb;
+	cb->qdisc_cb.flow_keys = &flow_keys;
+
+	if (!repeat)
+		repeat = 1;
+
+	time_start = ktime_get_ns();
+	for (i = 0; i < repeat; i++) {
+		preempt_disable();
+		rcu_read_lock();
+		retval = __skb_flow_bpf_dissect(prog, skb,
+						&flow_keys_dissector,
+						&flow_keys);
+		rcu_read_unlock();
+		preempt_enable();
+
+		if (need_resched()) {
+			if (signal_pending(current))
+				break;
+			time_spent += ktime_get_ns() - time_start;
+			cond_resched();
+			time_start = ktime_get_ns();
+		}
+	}
+	time_spent += ktime_get_ns() - time_start;
+	do_div(time_spent, repeat);
+	duration = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
+
+	ret = bpf_test_finish(kattr, uattr, &flow_keys, sizeof(flow_keys),
+			      retval, duration);
+
+	kfree_skb(skb);
+	kfree(sk);
+	return ret;
+}
diff --git a/net/core/filter.c b/net/core/filter.c
index 7559d6835ecb..41984ad4b9b4 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -6708,6 +6708,27 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type,
 							     target_size));
 		break;
 
+	case offsetof(struct __sk_buff, gso_segs):
+		/* si->dst_reg = skb_shinfo(SKB); */
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, head),
+				      si->dst_reg, si->src_reg,
+				      offsetof(struct sk_buff, head));
+		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, end),
+				      BPF_REG_AX, si->src_reg,
+				      offsetof(struct sk_buff, end));
+		*insn++ = BPF_ALU64_REG(BPF_ADD, si->dst_reg, BPF_REG_AX);
+#else
+		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, end),
+				      si->dst_reg, si->src_reg,
+				      offsetof(struct sk_buff, end));
+#endif
+		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct skb_shared_info, gso_segs),
+				      si->dst_reg, si->dst_reg,
+				      bpf_target_off(struct skb_shared_info,
+						     gso_segs, 2,
+						     target_size));
+		break;
 	case offsetof(struct __sk_buff, wire_len):
 		BUILD_BUG_ON(FIELD_SIZEOF(struct qdisc_skb_cb, pkt_len) != 4);
 
@@ -7698,6 +7719,7 @@ const struct bpf_verifier_ops flow_dissector_verifier_ops = {
 };
 
 const struct bpf_prog_ops flow_dissector_prog_ops = {
+	.test_run		= bpf_prog_test_run_flow_dissector,
 };
 
 int sk_detach_filter(struct sock *sk)
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 9f2840510e63..bb1a54747d64 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -683,6 +683,46 @@ static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys,
 	}
 }
 
+bool __skb_flow_bpf_dissect(struct bpf_prog *prog,
+			    const struct sk_buff *skb,
+			    struct flow_dissector *flow_dissector,
+			    struct bpf_flow_keys *flow_keys)
+{
+	struct bpf_skb_data_end cb_saved;
+	struct bpf_skb_data_end *cb;
+	u32 result;
+
+	/* Note that even though the const qualifier is discarded
+	 * throughout the execution of the BPF program, all changes(the
+	 * control block) are reverted after the BPF program returns.
+	 * Therefore, __skb_flow_dissect does not alter the skb.
+	 */
+
+	cb = (struct bpf_skb_data_end *)skb->cb;
+
+	/* Save Control Block */
+	memcpy(&cb_saved, cb, sizeof(cb_saved));
+	memset(cb, 0, sizeof(*cb));
+
+	/* Pass parameters to the BPF program */
+	memset(flow_keys, 0, sizeof(*flow_keys));
+	cb->qdisc_cb.flow_keys = flow_keys;
+	flow_keys->nhoff = skb_network_offset(skb);
+	flow_keys->thoff = flow_keys->nhoff;
+
+	bpf_compute_data_pointers((struct sk_buff *)skb);
+	result = BPF_PROG_RUN(prog, skb);
+
+	/* Restore state */
+	memcpy(cb, &cb_saved, sizeof(cb_saved));
+
+	flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, 0, skb->len);
+	flow_keys->thoff = clamp_t(u16, flow_keys->thoff,
+				   flow_keys->nhoff, skb->len);
+
+	return result == BPF_OK;
+}
+
 /**
  * __skb_flow_dissect - extract the flow_keys struct and return it
  * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
@@ -714,7 +754,6 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
 	struct flow_dissector_key_vlan *key_vlan;
 	enum flow_dissect_ret fdret;
 	enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
-	struct bpf_prog *attached = NULL;
 	int num_hdrs = 0;
 	u8 ip_proto = 0;
 	bool ret;
@@ -754,53 +793,30 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
 					      FLOW_DISSECTOR_KEY_BASIC,
 					      target_container);
 
-	rcu_read_lock();
 	if (skb) {
+		struct bpf_flow_keys flow_keys;
+		struct bpf_prog *attached = NULL;
+
+		rcu_read_lock();
+
 		if (skb->dev)
 			attached = rcu_dereference(dev_net(skb->dev)->flow_dissector_prog);
 		else if (skb->sk)
 			attached = rcu_dereference(sock_net(skb->sk)->flow_dissector_prog);
 		else
 			WARN_ON_ONCE(1);
-	}
-	if (attached) {
-		/* Note that even though the const qualifier is discarded
-		 * throughout the execution of the BPF program, all changes(the
-		 * control block) are reverted after the BPF program returns.
-		 * Therefore, __skb_flow_dissect does not alter the skb.
-		 */
-		struct bpf_flow_keys flow_keys = {};
-		struct bpf_skb_data_end cb_saved;
-		struct bpf_skb_data_end *cb;
-		u32 result;
-
-		cb = (struct bpf_skb_data_end *)skb->cb;
-
-		/* Save Control Block */
-		memcpy(&cb_saved, cb, sizeof(cb_saved));
-		memset(cb, 0, sizeof(cb_saved));
 
-		/* Pass parameters to the BPF program */
-		cb->qdisc_cb.flow_keys = &flow_keys;
-		flow_keys.nhoff = nhoff;
-		flow_keys.thoff = nhoff;
-
-		bpf_compute_data_pointers((struct sk_buff *)skb);
-		result = BPF_PROG_RUN(attached, skb);
-
-		/* Restore state */
-		memcpy(cb, &cb_saved, sizeof(cb_saved));
-
-		flow_keys.nhoff = clamp_t(u16, flow_keys.nhoff, 0, skb->len);
-		flow_keys.thoff = clamp_t(u16, flow_keys.thoff,
-					  flow_keys.nhoff, skb->len);
-
-		__skb_flow_bpf_to_target(&flow_keys, flow_dissector,
-					 target_container);
+		if (attached) {
+			ret = __skb_flow_bpf_dissect(attached, skb,
+						     flow_dissector,
+						     &flow_keys);
+			__skb_flow_bpf_to_target(&flow_keys, flow_dissector,
+						 target_container);
+			rcu_read_unlock();
+			return ret;
+		}
 		rcu_read_unlock();
-		return result == BPF_OK;
 	}
-	rcu_read_unlock();
 
 	if (dissector_uses_key(flow_dissector,
 			       FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
diff --git a/net/xdp/Kconfig b/net/xdp/Kconfig
index 90e4a7152854..0255b33cff4b 100644
--- a/net/xdp/Kconfig
+++ b/net/xdp/Kconfig
@@ -5,3 +5,11 @@ config XDP_SOCKETS
 	help
 	  XDP sockets allows a channel between XDP programs and
 	  userspace applications.
+
+config XDP_SOCKETS_DIAG
+	tristate "XDP sockets: monitoring interface"
+	depends on XDP_SOCKETS
+	default n
+	help
+	  Support for PF_XDP sockets monitoring interface used by the ss tool.
+	  If unsure, say Y.
diff --git a/net/xdp/Makefile b/net/xdp/Makefile
index 04f073146256..59dbfdf93dca 100644
--- a/net/xdp/Makefile
+++ b/net/xdp/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_XDP_SOCKETS) += xsk.o xdp_umem.o xsk_queue.o
+obj-$(CONFIG_XDP_SOCKETS_DIAG) += xsk_diag.o
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
index d74dfdc106b5..5ab236c5c9a5 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -13,12 +13,15 @@
 #include <linux/mm.h>
 #include <linux/netdevice.h>
 #include <linux/rtnetlink.h>
+#include <linux/idr.h>
 
 #include "xdp_umem.h"
 #include "xsk_queue.h"
 
 #define XDP_UMEM_MIN_CHUNK_SIZE 2048
 
+static DEFINE_IDA(umem_ida);
+
 void xdp_add_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs)
 {
 	unsigned long flags;
@@ -194,6 +197,8 @@ static void xdp_umem_release(struct xdp_umem *umem)
 
 	xdp_umem_clear_dev(umem);
 
+	ida_simple_remove(&umem_ida, umem->id);
+
 	if (umem->fq) {
 		xskq_destroy(umem->fq);
 		umem->fq = NULL;
@@ -400,8 +405,16 @@ struct xdp_umem *xdp_umem_create(struct xdp_umem_reg *mr)
 	if (!umem)
 		return ERR_PTR(-ENOMEM);
 
+	err = ida_simple_get(&umem_ida, 0, 0, GFP_KERNEL);
+	if (err < 0) {
+		kfree(umem);
+		return ERR_PTR(err);
+	}
+	umem->id = err;
+
 	err = xdp_umem_reg(umem, mr);
 	if (err) {
+		ida_simple_remove(&umem_ida, umem->id);
 		kfree(umem);
 		return ERR_PTR(err);
 	}
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index a03268454a27..949d3bbccb2f 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -27,14 +27,10 @@
 
 #include "xsk_queue.h"
 #include "xdp_umem.h"
+#include "xsk.h"
 
 #define TX_BATCH_SIZE 16
 
-static struct xdp_sock *xdp_sk(struct sock *sk)
-{
-	return (struct xdp_sock *)sk;
-}
-
 bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs)
 {
 	return READ_ONCE(xs->rx) &&  READ_ONCE(xs->umem) &&
@@ -350,6 +346,10 @@ static int xsk_release(struct socket *sock)
 
 	net = sock_net(sk);
 
+	mutex_lock(&net->xdp.lock);
+	sk_del_node_init_rcu(sk);
+	mutex_unlock(&net->xdp.lock);
+
 	local_bh_disable();
 	sock_prot_inuse_add(net, sk->sk_prot, -1);
 	local_bh_enable();
@@ -746,6 +746,10 @@ static int xsk_create(struct net *net, struct socket *sock, int protocol,
 	mutex_init(&xs->mutex);
 	spin_lock_init(&xs->tx_completion_lock);
 
+	mutex_lock(&net->xdp.lock);
+	sk_add_node_rcu(sk, &net->xdp.list);
+	mutex_unlock(&net->xdp.lock);
+
 	local_bh_disable();
 	sock_prot_inuse_add(net, &xsk_proto, 1);
 	local_bh_enable();
@@ -759,6 +763,23 @@ static const struct net_proto_family xsk_family_ops = {
 	.owner	= THIS_MODULE,
 };
 
+static int __net_init xsk_net_init(struct net *net)
+{
+	mutex_init(&net->xdp.lock);
+	INIT_HLIST_HEAD(&net->xdp.list);
+	return 0;
+}
+
+static void __net_exit xsk_net_exit(struct net *net)
+{
+	WARN_ON_ONCE(!hlist_empty(&net->xdp.list));
+}
+
+static struct pernet_operations xsk_net_ops = {
+	.init = xsk_net_init,
+	.exit = xsk_net_exit,
+};
+
 static int __init xsk_init(void)
 {
 	int err;
@@ -771,8 +792,13 @@ static int __init xsk_init(void)
 	if (err)
 		goto out_proto;
 
+	err = register_pernet_subsys(&xsk_net_ops);
+	if (err)
+		goto out_sk;
 	return 0;
 
+out_sk:
+	sock_unregister(PF_XDP);
 out_proto:
 	proto_unregister(&xsk_proto);
 out:
diff --git a/net/xdp/xsk.h b/net/xdp/xsk.h
new file mode 100644
index 000000000000..ba8120610426
--- /dev/null
+++ b/net/xdp/xsk.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright(c) 2019 Intel Corporation. */
+
+#ifndef XSK_H_
+#define XSK_H_
+
+static inline struct xdp_sock *xdp_sk(struct sock *sk)
+{
+	return (struct xdp_sock *)sk;
+}
+
+#endif /* XSK_H_ */
diff --git a/net/xdp/xsk_diag.c b/net/xdp/xsk_diag.c
new file mode 100644
index 000000000000..661d007c3b28
--- /dev/null
+++ b/net/xdp/xsk_diag.c
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: GPL-2.0
+/* XDP sockets monitoring support
+ *
+ * Copyright(c) 2019 Intel Corporation.
+ *
+ * Author: Björn Töpel <bjorn.topel@intel.com>
+ */
+
+#include <linux/module.h>
+#include <net/xdp_sock.h>
+#include <linux/xdp_diag.h>
+#include <linux/sock_diag.h>
+
+#include "xsk_queue.h"
+#include "xsk.h"
+
+static int xsk_diag_put_info(const struct xdp_sock *xs, struct sk_buff *nlskb)
+{
+	struct xdp_diag_info di = {};
+
+	di.ifindex = xs->dev ? xs->dev->ifindex : 0;
+	di.queue_id = xs->queue_id;
+	return nla_put(nlskb, XDP_DIAG_INFO, sizeof(di), &di);
+}
+
+static int xsk_diag_put_ring(const struct xsk_queue *queue, int nl_type,
+			     struct sk_buff *nlskb)
+{
+	struct xdp_diag_ring dr = {};
+
+	dr.entries = queue->nentries;
+	return nla_put(nlskb, nl_type, sizeof(dr), &dr);
+}
+
+static int xsk_diag_put_rings_cfg(const struct xdp_sock *xs,
+				  struct sk_buff *nlskb)
+{
+	int err = 0;
+
+	if (xs->rx)
+		err = xsk_diag_put_ring(xs->rx, XDP_DIAG_RX_RING, nlskb);
+	if (!err && xs->tx)
+		err = xsk_diag_put_ring(xs->tx, XDP_DIAG_TX_RING, nlskb);
+	return err;
+}
+
+static int xsk_diag_put_umem(const struct xdp_sock *xs, struct sk_buff *nlskb)
+{
+	struct xdp_umem *umem = xs->umem;
+	struct xdp_diag_umem du = {};
+	int err;
+
+	if (!umem)
+		return 0;
+
+	du.id = umem->id;
+	du.size = umem->size;
+	du.num_pages = umem->npgs;
+	du.chunk_size = (__u32)(~umem->chunk_mask + 1);
+	du.headroom = umem->headroom;
+	du.ifindex = umem->dev ? umem->dev->ifindex : 0;
+	du.queue_id = umem->queue_id;
+	du.flags = 0;
+	if (umem->zc)
+		du.flags |= XDP_DU_F_ZEROCOPY;
+	du.refs = refcount_read(&umem->users);
+
+	err = nla_put(nlskb, XDP_DIAG_UMEM, sizeof(du), &du);
+
+	if (!err && umem->fq)
+		err = xsk_diag_put_ring(xs->tx, XDP_DIAG_UMEM_FILL_RING, nlskb);
+	if (!err && umem->cq) {
+		err = xsk_diag_put_ring(xs->tx, XDP_DIAG_UMEM_COMPLETION_RING,
+					nlskb);
+	}
+	return err;
+}
+
+static int xsk_diag_fill(struct sock *sk, struct sk_buff *nlskb,
+			 struct xdp_diag_req *req,
+			 struct user_namespace *user_ns,
+			 u32 portid, u32 seq, u32 flags, int sk_ino)
+{
+	struct xdp_sock *xs = xdp_sk(sk);
+	struct xdp_diag_msg *msg;
+	struct nlmsghdr *nlh;
+
+	nlh = nlmsg_put(nlskb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*msg),
+			flags);
+	if (!nlh)
+		return -EMSGSIZE;
+
+	msg = nlmsg_data(nlh);
+	memset(msg, 0, sizeof(*msg));
+	msg->xdiag_family = AF_XDP;
+	msg->xdiag_type = sk->sk_type;
+	msg->xdiag_ino = sk_ino;
+	sock_diag_save_cookie(sk, msg->xdiag_cookie);
+
+	if ((req->xdiag_show & XDP_SHOW_INFO) && xsk_diag_put_info(xs, nlskb))
+		goto out_nlmsg_trim;
+
+	if ((req->xdiag_show & XDP_SHOW_INFO) &&
+	    nla_put_u32(nlskb, XDP_DIAG_UID,
+			from_kuid_munged(user_ns, sock_i_uid(sk))))
+		goto out_nlmsg_trim;
+
+	if ((req->xdiag_show & XDP_SHOW_RING_CFG) &&
+	    xsk_diag_put_rings_cfg(xs, nlskb))
+		goto out_nlmsg_trim;
+
+	if ((req->xdiag_show & XDP_SHOW_UMEM) &&
+	    xsk_diag_put_umem(xs, nlskb))
+		goto out_nlmsg_trim;
+
+	if ((req->xdiag_show & XDP_SHOW_MEMINFO) &&
+	    sock_diag_put_meminfo(sk, nlskb, XDP_DIAG_MEMINFO))
+		goto out_nlmsg_trim;
+
+	nlmsg_end(nlskb, nlh);
+	return 0;
+
+out_nlmsg_trim:
+	nlmsg_cancel(nlskb, nlh);
+	return -EMSGSIZE;
+}
+
+static int xsk_diag_dump(struct sk_buff *nlskb, struct netlink_callback *cb)
+{
+	struct xdp_diag_req *req = nlmsg_data(cb->nlh);
+	struct net *net = sock_net(nlskb->sk);
+	int num = 0, s_num = cb->args[0];
+	struct sock *sk;
+
+	mutex_lock(&net->xdp.lock);
+
+	sk_for_each(sk, &net->xdp.list) {
+		if (!net_eq(sock_net(sk), net))
+			continue;
+		if (num++ < s_num)
+			continue;
+
+		if (xsk_diag_fill(sk, nlskb, req,
+				  sk_user_ns(NETLINK_CB(cb->skb).sk),
+				  NETLINK_CB(cb->skb).portid,
+				  cb->nlh->nlmsg_seq, NLM_F_MULTI,
+				  sock_i_ino(sk)) < 0) {
+			num--;
+			break;
+		}
+	}
+
+	mutex_unlock(&net->xdp.lock);
+	cb->args[0] = num;
+	return nlskb->len;
+}
+
+static int xsk_diag_handler_dump(struct sk_buff *nlskb, struct nlmsghdr *hdr)
+{
+	struct netlink_dump_control c = { .dump = xsk_diag_dump };
+	int hdrlen = sizeof(struct xdp_diag_req);
+	struct net *net = sock_net(nlskb->sk);
+
+	if (nlmsg_len(hdr) < hdrlen)
+		return -EINVAL;
+
+	if (!(hdr->nlmsg_flags & NLM_F_DUMP))
+		return -EOPNOTSUPP;
+
+	return netlink_dump_start(net->diag_nlsk, nlskb, hdr, &c);
+}
+
+static const struct sock_diag_handler xsk_diag_handler = {
+	.family = AF_XDP,
+	.dump = xsk_diag_handler_dump,
+};
+
+static int __init xsk_diag_init(void)
+{
+	return sock_diag_register(&xsk_diag_handler);
+}
+
+static void __exit xsk_diag_exit(void)
+{
+	sock_diag_unregister(&xsk_diag_handler);
+}
+
+module_init(xsk_diag_init);
+module_exit(xsk_diag_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, AF_XDP);