#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <sched.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/mman.h>

static void execute_one(void)
{
	int idx = 0;
	const int ONE = 1;
	//  socket$can_j1939 arguments: [
	//    domain: const = 0x1d (8 bytes)
	//    type: const = 0x2 (8 bytes)
	//    proto: const = 0x7 (4 bytes)
	//  ]
	//  returns sock_can_j1939
	const int fd = socket(0x1d, 2, 7);
	//  ioctl$ifreq_SIOCGIFINDEX_vcan arguments: [
	//    fd: sock (resource)
	//    cmd: const = 0x8933 (4 bytes)
	//    arg: ptr[out, ifreq_dev_t[vcan_device_names, ifindex_vcan]] {
	//      ifreq_dev_t[vcan_device_names, ifindex_vcan] {
	//        ifr_ifrn: buffer: {76 63 61 6e 30 00 00 00 00 00 00 00 00 00 00 00}
	//        (length 0x10) elem: ifindex_vcan (resource) pad = 0x0 (20 bytes)
	//      }
	//    }
	//  ]
	memcpy((void*)0x200000001440,
	       "vcan0\000\000\000\000\000\000\000\000\000\000\000", 16);
	if (ioctl(fd, 0x8933, 0x200000001440ul) != -1)
		idx = *(uint32_t*)0x200000001450;
	//  bind$can_j1939 arguments: [
	//    fd: sock_can_j1939 (resource)
	//    addr: ptr[in, sockaddr_can_j1939] {
	//      sockaddr_can_j1939 {
	//        can_family: const = 0x1d (2 bytes)
	//        pad = 0x0 (2 bytes)
	//        can_ifindex: ifindex_vcan (resource)
	//        name: int64 = 0x0 (8 bytes)
	//        pgn: can_j1939_pgn {
	//          pgn_ps: can_j1939_pgn_ps = 0x1 (1 bytes)
	//          pgn_pf: can_j1939_pgn_pf = 0xf0 (1 bytes)
	//          pgn_flags: can_j1939_pgn_flags = 0x4 (1 bytes)
	//          pgn_unused: const = 0x0 (1 bytes)
	//        }
	//        addr: can_j1939_addrs = 0xfe (1 bytes)
	//        pad = 0x0 (3 bytes)
	//      }
	//    }
	//    len: bytesize = 0x18 (8 bytes)
	//  ]
	*(uint16_t*)0x200000000100 = 0x1d;
	*(uint32_t*)0x200000000104 = idx;
	*(uint64_t*)0x200000000108 = 0;
	*(uint8_t*)0x200000000110 = 1;
	*(uint8_t*)0x200000000111 = 0xf0;
	*(uint8_t*)0x200000000112 = 4;
	*(uint8_t*)0x200000000113 = 0;
	*(uint8_t*)0x200000000114 = 0xfe;
	bind(fd, (struct sockaddr *) 0x200000000100ul, 0x18ul);
	setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &ONE, sizeof(ONE));
	send(fd, "\x81\xb6\x41\xf1\xf3\x84\x37\x04\xb6", 9, 0);
	send(fd, "\x81\xb6\x41\xf1\xf3\x84\x37\x04\xb6", 9, 0);
}

int main(int argc, char *argv[])
{
	mmap((void *) 0x200000000000ul, 0x1000000ul,
	     PROT_WRITE|PROT_READ|PROT_EXEC,
	     MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
	if (unshare(CLONE_NEWNET))
		return 1;
	system("ip link add name vcan0 up type vcan");
	system("ip addr add 172.20.20.0/24 dev vcan0");
	execute_one();
	return 0;
}