Commit 7b8a1304 authored by Stanislav Fomichev's avatar Stanislav Fomichev Committed by Daniel Borkmann
Browse files

bpf: when doing BPF_PROG_TEST_RUN for flow dissector use no-skb mode 



Now that we have bpf_flow_dissect which can work on raw data,
use it when doing BPF_PROG_TEST_RUN for flow dissector.

Simplifies bpf_prog_test_run_flow_dissector and allows us to
test no-skb mode.

Note, that previously, with bpf_flow_dissect_skb we used to call
eth_type_trans which pulled L2 (ETH_HLEN) header and we explicitly called
skb_reset_network_header. That means flow_keys->nhoff would be
initialized to 0 (skb_network_offset) in init_flow_keys.
Now we call bpf_flow_dissect with nhoff set to ETH_HLEN and need
to undo it once the dissection is done to preserve the existing behavior.

Signed-off-by: default avatarStanislav Fomichev <sdf@google.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 089b19a9

net/bpf/test_run.c

+17 −30
Original line number Original line Diff line number Diff line
@@ -379,12 +379,12 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog, 
				     union bpf_attr __user *uattr)

				     union bpf_attr __user *uattr)

{

{

	u32 size = kattr->test.data_size_in;

	u32 size = kattr->test.data_size_in;

	struct bpf_flow_dissector ctx = {};

	u32 repeat = kattr->test.repeat;

	u32 repeat = kattr->test.repeat;

	struct bpf_flow_keys flow_keys;

	struct bpf_flow_keys flow_keys;

	u64 time_start, time_spent = 0;

	u64 time_start, time_spent = 0;

	const struct ethhdr *eth;

	u32 retval, duration;

	u32 retval, duration;

	struct sk_buff *skb;

	struct sock *sk;

	void *data;

	void *data;

	int ret;

	int ret;

	u32 i;

	u32 i;
@@ -395,43 +395,31 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog, 
	if (kattr->test.ctx_in || kattr->test.ctx_out)

	if (kattr->test.ctx_in || kattr->test.ctx_out)

		return -EINVAL;

		return -EINVAL;





	data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,

	if (size < ETH_HLEN)

			     SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));

		return -EINVAL;



	data = bpf_test_init(kattr, size, 0, 0);

	if (IS_ERR(data))

	if (IS_ERR(data))

		return PTR_ERR(data);

		return PTR_ERR(data);





	sk = kzalloc(sizeof(*sk), GFP_USER);

	eth = (struct ethhdr *)data;

	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);





	if (!repeat)

	if (!repeat)

		repeat = 1;

		repeat = 1;





	ctx.flow_keys = &flow_keys;

	ctx.data = data;

	ctx.data_end = (__u8 *)data + size;



	rcu_read_lock();

	rcu_read_lock();

	preempt_disable();

	preempt_disable();

	time_start = ktime_get_ns();

	time_start = ktime_get_ns();

	for (i = 0; i < repeat; i++) {

	for (i = 0; i < repeat; i++) {

		retval = __skb_flow_bpf_dissect(prog, skb,

		retval = bpf_flow_dissect(prog, &ctx, eth->h_proto, ETH_HLEN,

						&flow_keys_dissector,

					  size);

						&flow_keys);



		flow_keys.nhoff -= ETH_HLEN;

		flow_keys.thoff -= ETH_HLEN;





		if (signal_pending(current)) {

		if (signal_pending(current)) {

			preempt_enable();

			preempt_enable();
@@ -464,7 +452,6 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog, 
			      retval, duration);

			      retval, duration);





out:

out:

	kfree_skb(skb);

	kfree(data);

	kfree(sk);

	return ret;

	return ret;

}
 
}

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