tools/testing/selftests/bpf/progs/test_sockmap_kern.h - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0 */
 /* Copyright (c) 2017-2018 Covalent IO, Inc. http://covalent.io */
 #include <stddef.h>
 #include <string.h>
 #include <linux/bpf.h>
 #include <linux/if_ether.h>
 #include <linux/if_packet.h>
 #include <linux/ip.h>
 #include <linux/ipv6.h>
 #include <linux/in.h>
 #include <linux/udp.h>
 #include <linux/tcp.h>
 #include <linux/pkt_cls.h>
 #include <sys/socket.h>
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_endian.h>
 #include "bpf_misc.h"

 /* Sockmap sample program connects a client and a backend together
  * using cgroups.
  *
  *    client:X <---> frontend:80 client:X <---> backend:80
  *
  * For simplicity we hard code values here and bind 1:1. The hard
  * coded values are part of the setup in sockmap.sh script that
  * is associated with this BPF program.
  *
  * The bpf_printk is verbose and prints information as connections
  * are established and verdicts are decided.
  */

 struct {
 	__uint(type, TEST_MAP_TYPE);
 	__uint(max_entries, 20);
 	__uint(key_size, sizeof(int));
 	__uint(value_size, sizeof(int));
 } sock_map SEC(".maps");

 struct {
 	__uint(type, TEST_MAP_TYPE);
 	__uint(max_entries, 20);
 	__uint(key_size, sizeof(int));
 	__uint(value_size, sizeof(int));
 } sock_map_txmsg SEC(".maps");

 struct {
 	__uint(type, TEST_MAP_TYPE);
 	__uint(max_entries, 20);
 	__uint(key_size, sizeof(int));
 	__uint(value_size, sizeof(int));
 } sock_map_redir SEC(".maps");

 struct {
 	__uint(type, BPF_MAP_TYPE_ARRAY);
 	__uint(max_entries, 1);
 	__type(key, int);
 	__type(value, int);
 } sock_apply_bytes SEC(".maps");

 struct {
 	__uint(type, BPF_MAP_TYPE_ARRAY);
 	__uint(max_entries, 1);
 	__type(key, int);
 	__type(value, int);
 } sock_cork_bytes SEC(".maps");

 struct {
 	__uint(type, BPF_MAP_TYPE_ARRAY);
 	__uint(max_entries, 6);
 	__type(key, int);
 	__type(value, int);
 } sock_bytes SEC(".maps");

 struct {
 	__uint(type, BPF_MAP_TYPE_ARRAY);
 	__uint(max_entries, 1);
 	__type(key, int);
 	__type(value, int);
 } sock_redir_flags SEC(".maps");

 struct {
 	__uint(type, BPF_MAP_TYPE_ARRAY);
 	__uint(max_entries, 3);
 	__type(key, int);
 	__type(value, int);
 } sock_skb_opts SEC(".maps");

 struct {
 	__uint(type, TEST_MAP_TYPE);
 	__uint(max_entries, 20);
 	__uint(key_size, sizeof(int));
 	__uint(value_size, sizeof(int));
 } tls_sock_map SEC(".maps");

 SEC("sk_skb1")
 int bpf_prog1(struct __sk_buff *skb)
 {
 	int *f, two = 2;

 	f = bpf_map_lookup_elem(&sock_skb_opts, &two);
 	if (f && *f) {
 		return *f;
 	}
 	return skb->len;
 }

 SEC("sk_skb2")
 int bpf_prog2(struct __sk_buff *skb)
 {
 	__u32 lport = skb->local_port;
 	__u32 rport = skb->remote_port;
 	int len, *f, ret, zero = 0;
 	__u64 flags = 0;

 	__sink(rport);
 	if (lport == 10000)
 		ret = 10;
 	else
 		ret = 1;

 	len = (__u32)skb->data_end - (__u32)skb->data;
 	__sink(len);

 	f = bpf_map_lookup_elem(&sock_skb_opts, &zero);
 	if (f && *f) {
 		ret = 3;
 		flags = *f;
 	}

 #ifdef SOCKMAP
 	return bpf_sk_redirect_map(skb, &sock_map, ret, flags);
 #else
 	return bpf_sk_redirect_hash(skb, &sock_map, &ret, flags);
 #endif

 }

 static inline void bpf_write_pass(struct __sk_buff *skb, int offset)
 {
 	int err = bpf_skb_pull_data(skb, 6 + offset);
 	void *data_end;
 	char *c;

 	if (err)
 		return;

 	c = (char *)(long)skb->data;
 	data_end = (void *)(long)skb->data_end;

 	if (c + 5 + offset < data_end)
 		memcpy(c + offset, "PASS", 4);
 }

 SEC("sk_skb3")
 int bpf_prog3(struct __sk_buff *skb)
 {
 	int err, *f, ret = SK_PASS;
 	const int one = 1;

 	f = bpf_map_lookup_elem(&sock_skb_opts, &one);
 	if (f && *f) {
 		__u64 flags = 0;

 		ret = 0;
 		flags = *f;

 		err = bpf_skb_adjust_room(skb, -13, 0, 0);
 		if (err)
 			return SK_DROP;
 		err = bpf_skb_adjust_room(skb, 4, 0, 0);
 		if (err)
 			return SK_DROP;
 		bpf_write_pass(skb, 0);
 #ifdef SOCKMAP
 		return bpf_sk_redirect_map(skb, &tls_sock_map, ret, flags);
 #else
 		return bpf_sk_redirect_hash(skb, &tls_sock_map, &ret, flags);
 #endif
 	}
 	f = bpf_map_lookup_elem(&sock_skb_opts, &one);
 	if (f && *f)
 		ret = SK_DROP;
 	err = bpf_skb_adjust_room(skb, 4, 0, 0);
 	if (err)
 		return SK_DROP;
 	bpf_write_pass(skb, 13);
 	return ret;
 }

 SEC("sockops")
 int bpf_sockmap(struct bpf_sock_ops *skops)
 {
 	__u32 lport, rport;
 	int op, ret;

 	op = (int) skops->op;

 	switch (op) {
 	case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
 		lport = skops->local_port;
 		rport = skops->remote_port;

 		if (lport == 10000) {
 			ret = 1;
 #ifdef SOCKMAP
 			bpf_sock_map_update(skops, &sock_map, &ret,
 						  BPF_NOEXIST);
 #else
 			bpf_sock_hash_update(skops, &sock_map, &ret,
 						   BPF_NOEXIST);
 #endif
 		}
 		break;
 	case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
 		lport = skops->local_port;
 		rport = skops->remote_port;

 		if (bpf_ntohl(rport) == 10001) {
 			ret = 10;
 #ifdef SOCKMAP
 			bpf_sock_map_update(skops, &sock_map, &ret,
 						  BPF_NOEXIST);
 #else
 			bpf_sock_hash_update(skops, &sock_map, &ret,
 						   BPF_NOEXIST);
 #endif
 		}
 		break;
 	default:
 		break;
 	}

 	return 0;
 }

 SEC("sk_msg1")
 int bpf_prog4(struct sk_msg_md *msg)
 {
 	int *bytes, zero = 0, one = 1, two = 2, three = 3, four = 4, five = 5;
 	int *start, *end, *start_push, *end_push, *start_pop, *pop, err = 0;

 	bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);
 	if (bytes)
 		bpf_msg_apply_bytes(msg, *bytes);
 	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);
 	if (bytes)
 		bpf_msg_cork_bytes(msg, *bytes);
 	start = bpf_map_lookup_elem(&sock_bytes, &zero);
 	end = bpf_map_lookup_elem(&sock_bytes, &one);
 	if (start && end)
 		bpf_msg_pull_data(msg, *start, *end, 0);
 	start_push = bpf_map_lookup_elem(&sock_bytes, &two);
 	end_push = bpf_map_lookup_elem(&sock_bytes, &three);
 	if (start_push && end_push) {
 		err = bpf_msg_push_data(msg, *start_push, *end_push, 0);
 		if (err)
 			return SK_DROP;
 	}
 	start_pop = bpf_map_lookup_elem(&sock_bytes, &four);
 	pop = bpf_map_lookup_elem(&sock_bytes, &five);
 	if (start_pop && pop)
 		bpf_msg_pop_data(msg, *start_pop, *pop, 0);
 	return SK_PASS;
 }

 SEC("sk_msg2")
 int bpf_prog6(struct sk_msg_md *msg)
 {
 	int zero = 0, one = 1, two = 2, three = 3, four = 4, five = 5, key = 0;
 	int *bytes, *start, *end, *start_push, *end_push, *start_pop, *pop, *f;
 	int err = 0;
 	__u64 flags = 0;

 	bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);
 	if (bytes)
 		bpf_msg_apply_bytes(msg, *bytes);
 	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);
 	if (bytes)
 		bpf_msg_cork_bytes(msg, *bytes);

 	start = bpf_map_lookup_elem(&sock_bytes, &zero);
 	end = bpf_map_lookup_elem(&sock_bytes, &one);
 	if (start && end)
 		bpf_msg_pull_data(msg, *start, *end, 0);

 	start_push = bpf_map_lookup_elem(&sock_bytes, &two);
 	end_push = bpf_map_lookup_elem(&sock_bytes, &three);
 	if (start_push && end_push) {
 		err = bpf_msg_push_data(msg, *start_push, *end_push, 0);
 		if (err)
 			return SK_DROP;
 	}

 	start_pop = bpf_map_lookup_elem(&sock_bytes, &four);
 	pop = bpf_map_lookup_elem(&sock_bytes, &five);
 	if (start_pop && pop)
 		bpf_msg_pop_data(msg, *start_pop, *pop, 0);

 	f = bpf_map_lookup_elem(&sock_redir_flags, &zero);
 	if (f && *f) {
 		key = 2;
 		flags = *f;
 	}
 #ifdef SOCKMAP
 	return bpf_msg_redirect_map(msg, &sock_map_redir, key, flags);
 #else
 	return bpf_msg_redirect_hash(msg, &sock_map_redir, &key, flags);
 #endif
 }

 SEC("sk_msg3")
 int bpf_prog8(struct sk_msg_md *msg)
 {
 	void *data_end = (void *)(long) msg->data_end;
 	void *data = (void *)(long) msg->data;
 	int ret = 0, *bytes, zero = 0;

 	bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);
 	if (bytes) {
 		ret = bpf_msg_apply_bytes(msg, *bytes);
 		if (ret)
 			return SK_DROP;
 	} else {
 		return SK_DROP;
 	}

 	__sink(data_end);
 	__sink(data);

 	return SK_PASS;
 }
 SEC("sk_msg4")
 int bpf_prog9(struct sk_msg_md *msg)
 {
 	void *data_end = (void *)(long) msg->data_end;
 	void *data = (void *)(long) msg->data;
 	int ret = 0, *bytes, zero = 0;

 	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);
 	if (bytes) {
 		if (((__u64)data_end - (__u64)data) >= *bytes)
 			return SK_PASS;
 		ret = bpf_msg_cork_bytes(msg, *bytes);
 		if (ret)
 			return SK_DROP;
 	}
 	return SK_PASS;
 }

 SEC("sk_msg5")
 int bpf_prog10(struct sk_msg_md *msg)
 {
 	int *bytes, *start, *end, *start_push, *end_push, *start_pop, *pop;
 	int zero = 0, one = 1, two = 2, three = 3, four = 4, five = 5, err = 0;

 	bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);
 	if (bytes)
 		bpf_msg_apply_bytes(msg, *bytes);
 	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);
 	if (bytes)
 		bpf_msg_cork_bytes(msg, *bytes);
 	start = bpf_map_lookup_elem(&sock_bytes, &zero);
 	end = bpf_map_lookup_elem(&sock_bytes, &one);
 	if (start && end)
 		bpf_msg_pull_data(msg, *start, *end, 0);
 	start_push = bpf_map_lookup_elem(&sock_bytes, &two);
 	end_push = bpf_map_lookup_elem(&sock_bytes, &three);
 	if (start_push && end_push) {
 		err = bpf_msg_push_data(msg, *start_push, *end_push, 0);
 		if (err)
 			return SK_PASS;
 	}
 	start_pop = bpf_map_lookup_elem(&sock_bytes, &four);
 	pop = bpf_map_lookup_elem(&sock_bytes, &five);
 	if (start_pop && pop)
 		bpf_msg_pop_data(msg, *start_pop, *pop, 0);
 	return SK_DROP;
 }

 char _license[] SEC("license") = "GPL";
	/* SPDX-License-Identifier: GPL-2.0 */
	/* Copyright (c) 2017-2018 Covalent IO, Inc. http://covalent.io */
	#include <stddef.h>
	#include <string.h>
	#include <linux/bpf.h>
	#include <linux/if_ether.h>
	#include <linux/if_packet.h>
	#include <linux/ip.h>
	#include <linux/ipv6.h>
	#include <linux/in.h>
	#include <linux/udp.h>
	#include <linux/tcp.h>
	#include <linux/pkt_cls.h>
	#include <sys/socket.h>
	#include <bpf/bpf_helpers.h>
	#include <bpf/bpf_endian.h>
	#include "bpf_misc.h"

	/* Sockmap sample program connects a client and a backend together
	* using cgroups.
	*
	* client:X <---> frontend:80 client:X <---> backend:80
	*
	* For simplicity we hard code values here and bind 1:1. The hard
	* coded values are part of the setup in sockmap.sh script that
	* is associated with this BPF program.
	*
	* The bpf_printk is verbose and prints information as connections
	* are established and verdicts are decided.
	*/

	struct {
	__uint(type, TEST_MAP_TYPE);
	__uint(max_entries, 20);
	__uint(key_size, sizeof(int));
	__uint(value_size, sizeof(int));
	} sock_map SEC(".maps");

	struct {
	__uint(type, TEST_MAP_TYPE);
	__uint(max_entries, 20);
	__uint(key_size, sizeof(int));
	__uint(value_size, sizeof(int));
	} sock_map_txmsg SEC(".maps");

	struct {
	__uint(type, TEST_MAP_TYPE);
	__uint(max_entries, 20);
	__uint(key_size, sizeof(int));
	__uint(value_size, sizeof(int));
	} sock_map_redir SEC(".maps");

	struct {
	__uint(type, BPF_MAP_TYPE_ARRAY);
	__uint(max_entries, 1);
	__type(key, int);
	__type(value, int);
	} sock_apply_bytes SEC(".maps");

	struct {
	__uint(type, BPF_MAP_TYPE_ARRAY);
	__uint(max_entries, 1);
	__type(key, int);
	__type(value, int);
	} sock_cork_bytes SEC(".maps");

	struct {
	__uint(type, BPF_MAP_TYPE_ARRAY);
	__uint(max_entries, 6);
	__type(key, int);
	__type(value, int);
	} sock_bytes SEC(".maps");

	struct {
	__uint(type, BPF_MAP_TYPE_ARRAY);
	__uint(max_entries, 1);
	__type(key, int);
	__type(value, int);
	} sock_redir_flags SEC(".maps");

	struct {
	__uint(type, BPF_MAP_TYPE_ARRAY);
	__uint(max_entries, 3);
	__type(key, int);
	__type(value, int);
	} sock_skb_opts SEC(".maps");

	struct {
	__uint(type, TEST_MAP_TYPE);
	__uint(max_entries, 20);
	__uint(key_size, sizeof(int));
	__uint(value_size, sizeof(int));
	} tls_sock_map SEC(".maps");

	SEC("sk_skb1")
	int bpf_prog1(struct __sk_buff *skb)
	{
	int *f, two = 2;

	f = bpf_map_lookup_elem(&sock_skb_opts, &two);
	if (f && *f) {
	return *f;
	}
	return skb->len;
	}

	SEC("sk_skb2")
	int bpf_prog2(struct __sk_buff *skb)
	{
	__u32 lport = skb->local_port;
	__u32 rport = skb->remote_port;
	int len, *f, ret, zero = 0;
	__u64 flags = 0;

	__sink(rport);
	if (lport == 10000)
	ret = 10;
	else
	ret = 1;

	len = (__u32)skb->data_end - (__u32)skb->data;
	__sink(len);

	f = bpf_map_lookup_elem(&sock_skb_opts, &zero);
	if (f && *f) {
	ret = 3;
	flags = *f;
	}

	#ifdef SOCKMAP
	return bpf_sk_redirect_map(skb, &sock_map, ret, flags);
	#else
	return bpf_sk_redirect_hash(skb, &sock_map, &ret, flags);
	#endif

	}

	static inline void bpf_write_pass(struct __sk_buff *skb, int offset)
	{
	int err = bpf_skb_pull_data(skb, 6 + offset);
	void *data_end;
	char *c;

	if (err)
	return;

	c = (char *)(long)skb->data;
	data_end = (void *)(long)skb->data_end;

	if (c + 5 + offset < data_end)
	memcpy(c + offset, "PASS", 4);
	}

	SEC("sk_skb3")
	int bpf_prog3(struct __sk_buff *skb)
	{
	int err, *f, ret = SK_PASS;
	const int one = 1;

	f = bpf_map_lookup_elem(&sock_skb_opts, &one);
	if (f && *f) {
	__u64 flags = 0;

	ret = 0;
	flags = *f;

	err = bpf_skb_adjust_room(skb, -13, 0, 0);
	if (err)
	return SK_DROP;
	err = bpf_skb_adjust_room(skb, 4, 0, 0);
	if (err)
	return SK_DROP;
	bpf_write_pass(skb, 0);
	#ifdef SOCKMAP
	return bpf_sk_redirect_map(skb, &tls_sock_map, ret, flags);
	#else
	return bpf_sk_redirect_hash(skb, &tls_sock_map, &ret, flags);
	#endif
	}
	f = bpf_map_lookup_elem(&sock_skb_opts, &one);
	if (f && *f)
	ret = SK_DROP;
	err = bpf_skb_adjust_room(skb, 4, 0, 0);
	if (err)
	return SK_DROP;
	bpf_write_pass(skb, 13);
	return ret;
	}

	SEC("sockops")
	int bpf_sockmap(struct bpf_sock_ops *skops)
	{
	__u32 lport, rport;
	int op, ret;

	op = (int) skops->op;

	switch (op) {
	case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
	lport = skops->local_port;
	rport = skops->remote_port;

	if (lport == 10000) {
	ret = 1;
	#ifdef SOCKMAP
	bpf_sock_map_update(skops, &sock_map, &ret,
	BPF_NOEXIST);
	#else
	bpf_sock_hash_update(skops, &sock_map, &ret,
	BPF_NOEXIST);
	#endif
	}
	break;
	case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
	lport = skops->local_port;
	rport = skops->remote_port;

	if (bpf_ntohl(rport) == 10001) {
	ret = 10;
	#ifdef SOCKMAP
	bpf_sock_map_update(skops, &sock_map, &ret,
	BPF_NOEXIST);
	#else
	bpf_sock_hash_update(skops, &sock_map, &ret,
	BPF_NOEXIST);
	#endif
	}
	break;
	default:
	break;
	}

	return 0;
	}

	SEC("sk_msg1")
	int bpf_prog4(struct sk_msg_md *msg)
	{
	int *bytes, zero = 0, one = 1, two = 2, three = 3, four = 4, five = 5;
	int start, end, start_push, end_push, start_pop, pop, err = 0;

	bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);
	if (bytes)
	bpf_msg_apply_bytes(msg, *bytes);
	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);
	if (bytes)
	bpf_msg_cork_bytes(msg, *bytes);
	start = bpf_map_lookup_elem(&sock_bytes, &zero);
	end = bpf_map_lookup_elem(&sock_bytes, &one);
	if (start && end)
	bpf_msg_pull_data(msg, start, end, 0);
	start_push = bpf_map_lookup_elem(&sock_bytes, &two);
	end_push = bpf_map_lookup_elem(&sock_bytes, &three);
	if (start_push && end_push) {
	err = bpf_msg_push_data(msg, start_push, end_push, 0);
	if (err)
	return SK_DROP;
	}
	start_pop = bpf_map_lookup_elem(&sock_bytes, &four);
	pop = bpf_map_lookup_elem(&sock_bytes, &five);
	if (start_pop && pop)
	bpf_msg_pop_data(msg, start_pop, pop, 0);
	return SK_PASS;
	}

	SEC("sk_msg2")
	int bpf_prog6(struct sk_msg_md *msg)
	{
	int zero = 0, one = 1, two = 2, three = 3, four = 4, five = 5, key = 0;
	int bytes, start, end, start_push, end_push, start_pop, pop, f;
	int err = 0;
	__u64 flags = 0;

	bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);
	if (bytes)
	bpf_msg_apply_bytes(msg, *bytes);
	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);
	if (bytes)
	bpf_msg_cork_bytes(msg, *bytes);

	start = bpf_map_lookup_elem(&sock_bytes, &zero);
	end = bpf_map_lookup_elem(&sock_bytes, &one);
	if (start && end)
	bpf_msg_pull_data(msg, start, end, 0);

	start_push = bpf_map_lookup_elem(&sock_bytes, &two);
	end_push = bpf_map_lookup_elem(&sock_bytes, &three);
	if (start_push && end_push) {
	err = bpf_msg_push_data(msg, start_push, end_push, 0);
	if (err)
	return SK_DROP;
	}

	start_pop = bpf_map_lookup_elem(&sock_bytes, &four);
	pop = bpf_map_lookup_elem(&sock_bytes, &five);
	if (start_pop && pop)
	bpf_msg_pop_data(msg, start_pop, pop, 0);

	f = bpf_map_lookup_elem(&sock_redir_flags, &zero);
	if (f && *f) {
	key = 2;
	flags = *f;
	}
	#ifdef SOCKMAP
	return bpf_msg_redirect_map(msg, &sock_map_redir, key, flags);
	#else
	return bpf_msg_redirect_hash(msg, &sock_map_redir, &key, flags);
	#endif
	}

	SEC("sk_msg3")
	int bpf_prog8(struct sk_msg_md *msg)
	{
	void data_end = (void )(long) msg->data_end;
	void data = (void )(long) msg->data;
	int ret = 0, *bytes, zero = 0;

	bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);
	if (bytes) {
	ret = bpf_msg_apply_bytes(msg, *bytes);
	if (ret)
	return SK_DROP;
	} else {
	return SK_DROP;
	}

	__sink(data_end);
	__sink(data);

	return SK_PASS;
	}
	SEC("sk_msg4")
	int bpf_prog9(struct sk_msg_md *msg)
	{
	void data_end = (void )(long) msg->data_end;
	void data = (void )(long) msg->data;
	int ret = 0, *bytes, zero = 0;

	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);
	if (bytes) {
	if (((__u64)data_end - (__u64)data) >= *bytes)
	return SK_PASS;
	ret = bpf_msg_cork_bytes(msg, *bytes);
	if (ret)
	return SK_DROP;
	}
	return SK_PASS;
	}

	SEC("sk_msg5")
	int bpf_prog10(struct sk_msg_md *msg)
	{
	int bytes, start, end, start_push, end_push, start_pop, *pop;
	int zero = 0, one = 1, two = 2, three = 3, four = 4, five = 5, err = 0;

	bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);
	if (bytes)
	bpf_msg_apply_bytes(msg, *bytes);
	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);
	if (bytes)
	bpf_msg_cork_bytes(msg, *bytes);
	start = bpf_map_lookup_elem(&sock_bytes, &zero);
	end = bpf_map_lookup_elem(&sock_bytes, &one);
	if (start && end)
	bpf_msg_pull_data(msg, start, end, 0);
	start_push = bpf_map_lookup_elem(&sock_bytes, &two);
	end_push = bpf_map_lookup_elem(&sock_bytes, &three);
	if (start_push && end_push) {
	err = bpf_msg_push_data(msg, start_push, end_push, 0);
	if (err)
	return SK_PASS;
	}
	start_pop = bpf_map_lookup_elem(&sock_bytes, &four);
	pop = bpf_map_lookup_elem(&sock_bytes, &five);
	if (start_pop && pop)
	bpf_msg_pop_data(msg, start_pop, pop, 0);
	return SK_DROP;
	}

	char _license[] SEC("license") = "GPL";