/* eBPF mini library */
#include <stdlib.h>
#include <stdio.h>
#include <linux/unistd.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <linux/if_packet.h>
#include <arpa/inet.h>
#include "libbpf.h"

int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type)
{
	union bpf_attr attr = {
		.target_fd = target_fd,
		.attach_bpf_fd = prog_fd,
		.attach_type = type,
	};

	return syscall(__NR_bpf, BPF_PROG_ATTACH, &attr, sizeof(attr));
}

int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
{
	union bpf_attr attr = {
		.target_fd = target_fd,
		.attach_type = type,
	};

	return syscall(__NR_bpf, BPF_PROG_DETACH, &attr, sizeof(attr));
}

int open_raw_sock(const char *name)
{
	struct sockaddr_ll sll;
	int sock;

	sock = socket(PF_PACKET, SOCK_RAW | SOCK_NONBLOCK | SOCK_CLOEXEC, htons(ETH_P_ALL));
	if (sock < 0) {
		printf("cannot create raw socket\n");
		return -1;
	}

	memset(&sll, 0, sizeof(sll));
	sll.sll_family = AF_PACKET;
	sll.sll_ifindex = if_nametoindex(name);
	sll.sll_protocol = htons(ETH_P_ALL);
	if (bind(sock, (struct sockaddr *)&sll, sizeof(sll)) < 0) {
		printf("bind to %s: %s\n", name, strerror(errno));
		close(sock);
		return -1;
	}

	return sock;
}

int perf_event_open(struct perf_event_attr *attr, int pid, int cpu,
		    int group_fd, unsigned long flags)
{
	return syscall(__NR_perf_event_open, attr, pid, cpu,
		       group_fd, flags);
}