// https://syzkaller.appspot.com/bug?id=5107d31a0b732a3ba93d5c5e08a6e349c29f3126
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <arpa/inet.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <linux/futex.h>
#include <linux/if.h>
#include <linux/if_ether.h>
#include <linux/if_tun.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <net/if_arp.h>
#include <pthread.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/uio.h>
#include <unistd.h>

__attribute__((noreturn)) static void doexit(int status)
{
  volatile unsigned i;
  syscall(__NR_exit_group, status);
  for (i = 0;; i++) {
  }
}
#include <stdint.h>
#include <string.h>

const int kFailStatus = 67;
const int kRetryStatus = 69;

static void fail(const char* msg, ...)
{
  int e = errno;
  va_list args;
  va_start(args, msg);
  vfprintf(stderr, msg, args);
  va_end(args);
  fprintf(stderr, " (errno %d)\n", e);
  doexit((e == ENOMEM || e == EAGAIN) ? kRetryStatus : kFailStatus);
}

static void vsnprintf_check(char* str, size_t size, const char* format,
                            va_list args)
{
  int rv;

  rv = vsnprintf(str, size, format, args);
  if (rv < 0)
    fail("tun: snprintf failed");
  if ((size_t)rv >= size)
    fail("tun: string '%s...' doesn't fit into buffer", str);
}

static void snprintf_check(char* str, size_t size, const char* format, ...)
{
  va_list args;

  va_start(args, format);
  vsnprintf_check(str, size, format, args);
  va_end(args);
}

#define COMMAND_MAX_LEN 128
#define PATH_PREFIX                                                            \
  "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin "
#define PATH_PREFIX_LEN (sizeof(PATH_PREFIX) - 1)

static void execute_command(bool panic, const char* format, ...)
{
  va_list args;
  char command[PATH_PREFIX_LEN + COMMAND_MAX_LEN];
  int rv;

  va_start(args, format);
  memcpy(command, PATH_PREFIX, PATH_PREFIX_LEN);
  vsnprintf_check(command + PATH_PREFIX_LEN, COMMAND_MAX_LEN, format, args);
  rv = system(command);
  if (panic && rv != 0)
    fail("tun: command \"%s\" failed with code %d", &command[0], rv);

  va_end(args);
}

static int tunfd = -1;
static int tun_frags_enabled;

#define SYZ_TUN_MAX_PACKET_SIZE 1000

#define MAX_PIDS 32
#define ADDR_MAX_LEN 32

#define LOCAL_MAC "aa:aa:aa:aa:%02hx:aa"
#define REMOTE_MAC "aa:aa:aa:aa:%02hx:bb"

#define LOCAL_IPV4 "172.20.%d.170"
#define REMOTE_IPV4 "172.20.%d.187"

#define LOCAL_IPV6 "fe80::%02hx:aa"
#define REMOTE_IPV6 "fe80::%02hx:bb"

#define IFF_NAPI 0x0010
#define IFF_NAPI_FRAGS 0x0020

static void initialize_tun(int id)
{
  if (id >= MAX_PIDS)
    fail("tun: no more than %d executors", MAX_PIDS);

  tunfd = open("/dev/net/tun", O_RDWR | O_NONBLOCK);
  if (tunfd == -1) {
    printf("tun: can't open /dev/net/tun: please enable CONFIG_TUN=y\n");
    printf("otherwise fuzzing or reproducing might not work as intended\n");
    return;
  }

  char iface[IFNAMSIZ];
  snprintf_check(iface, sizeof(iface), "syz%d", id);

  struct ifreq ifr;
  memset(&ifr, 0, sizeof(ifr));
  strncpy(ifr.ifr_name, iface, IFNAMSIZ);
  ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_NAPI | IFF_NAPI_FRAGS;
  if (ioctl(tunfd, TUNSETIFF, (void*)&ifr) < 0) {
    ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
    if (ioctl(tunfd, TUNSETIFF, (void*)&ifr) < 0)
      fail("tun: ioctl(TUNSETIFF) failed");
  }
  if (ioctl(tunfd, TUNGETIFF, (void*)&ifr) < 0)
    fail("tun: ioctl(TUNGETIFF) failed");
  tun_frags_enabled = (ifr.ifr_flags & IFF_NAPI_FRAGS) != 0;

  char local_mac[ADDR_MAX_LEN];
  snprintf_check(local_mac, sizeof(local_mac), LOCAL_MAC, id);
  char remote_mac[ADDR_MAX_LEN];
  snprintf_check(remote_mac, sizeof(remote_mac), REMOTE_MAC, id);

  char local_ipv4[ADDR_MAX_LEN];
  snprintf_check(local_ipv4, sizeof(local_ipv4), LOCAL_IPV4, id);
  char remote_ipv4[ADDR_MAX_LEN];
  snprintf_check(remote_ipv4, sizeof(remote_ipv4), REMOTE_IPV4, id);

  char local_ipv6[ADDR_MAX_LEN];
  snprintf_check(local_ipv6, sizeof(local_ipv6), LOCAL_IPV6, id);
  char remote_ipv6[ADDR_MAX_LEN];
  snprintf_check(remote_ipv6, sizeof(remote_ipv6), REMOTE_IPV6, id);

  execute_command(1, "sysctl -w net.ipv6.conf.%s.accept_dad=0", iface);

  execute_command(1, "sysctl -w net.ipv6.conf.%s.router_solicitations=0",
                  iface);

  execute_command(1, "ip link set dev %s address %s", iface, local_mac);
  execute_command(1, "ip addr add %s/24 dev %s", local_ipv4, iface);
  execute_command(1, "ip -6 addr add %s/120 dev %s", local_ipv6, iface);
  execute_command(1, "ip neigh add %s lladdr %s dev %s nud permanent",
                  remote_ipv4, remote_mac, iface);
  execute_command(1, "ip -6 neigh add %s lladdr %s dev %s nud permanent",
                  remote_ipv6, remote_mac, iface);
  execute_command(1, "ip link set dev %s up", iface);
}

#define DEV_IPV4 "172.20.%d.%d"
#define DEV_IPV6 "fe80::%02hx:%02hx"
#define DEV_MAC "aa:aa:aa:aa:%02hx:%02hx"

static void initialize_netdevices(int id)
{
  unsigned i;
  const char* devtypes[] = {"ip6gretap", "bridge", "vcan"};
  const char* devnames[] = {"lo",       "sit0",    "bridge0", "vcan0",
                            "tunl0",    "gre0",    "gretap0", "ip_vti0",
                            "ip6_vti0", "ip6tnl0", "ip6gre0", "ip6gretap0",
                            "erspan0"};

  for (i = 0; i < sizeof(devtypes) / (sizeof(devtypes[0])); i++)
    execute_command(0, "ip link add dev %s0 type %s", devtypes[i], devtypes[i]);
  for (i = 0; i < sizeof(devnames) / (sizeof(devnames[0])); i++) {
    char addr[ADDR_MAX_LEN];
    snprintf_check(addr, sizeof(addr), DEV_IPV4, id, id + 10);
    execute_command(0, "ip -4 addr add %s/24 dev %s", addr, devnames[i]);
    snprintf_check(addr, sizeof(addr), DEV_IPV6, id, id + 10);
    execute_command(0, "ip -6 addr add %s/120 dev %s", addr, devnames[i]);
    snprintf_check(addr, sizeof(addr), DEV_MAC, id, id + 10);
    execute_command(0, "ip link set dev %s address %s", devnames[i], addr);
    execute_command(0, "ip link set dev %s up", devnames[i]);
  }
}

static void setup_tun(uint64_t pid, bool enable_tun)
{
  if (enable_tun) {
    initialize_tun(pid);
    initialize_netdevices(pid);
  }
}

static void test();

void loop()
{
  while (1) {
    test();
  }
}

struct thread_t {
  int created, running, call;
  pthread_t th;
};

static struct thread_t threads[16];
static void execute_call(int call);
static int running;

static void* thr(void* arg)
{
  struct thread_t* th = (struct thread_t*)arg;
  for (;;) {
    while (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE))
      syscall(SYS_futex, &th->running, FUTEX_WAIT, 0, 0);
    execute_call(th->call);
    __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED);
    __atomic_store_n(&th->running, 0, __ATOMIC_RELEASE);
    syscall(SYS_futex, &th->running, FUTEX_WAKE);
  }
  return 0;
}

static void execute(int num_calls)
{
  int call, thread;
  running = 0;
  for (call = 0; call < num_calls; call++) {
    for (thread = 0; thread < sizeof(threads) / sizeof(threads[0]); thread++) {
      struct thread_t* th = &threads[thread];
      if (!th->created) {
        th->created = 1;
        pthread_attr_t attr;
        pthread_attr_init(&attr);
        pthread_attr_setstacksize(&attr, 128 << 10);
        pthread_create(&th->th, &attr, thr, th);
      }
      if (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) {
        th->call = call;
        __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED);
        __atomic_store_n(&th->running, 1, __ATOMIC_RELEASE);
        syscall(SYS_futex, &th->running, FUTEX_WAKE);
        struct timespec ts;
        ts.tv_sec = 0;
        ts.tv_nsec = 20 * 1000 * 1000;
        syscall(SYS_futex, &th->running, FUTEX_WAIT, 1, &ts);
        if (running)
          usleep((call == num_calls - 1) ? 10000 : 1000);
        break;
      }
    }
  }
}

long r[5];
uint64_t procid;
void execute_call(int call)
{
  switch (call) {
  case 0:
    syscall(__NR_mmap, 0x20000000, 0xfff000, 3, 0x32, -1, 0);
    break;
  case 1:
    r[0] = syscall(__NR_socket, 2, 0x80a, 0);
    break;
  case 2:
    memcpy((void*)0x208a3fe0,
           "\x6c\x6f\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
           16);
    *(uint16_t*)0x208a3ff0 = 0xfffd;
    syscall(__NR_ioctl, r[0], 0x8914, 0x208a3fe0);
    break;
  case 3:
    r[1] = syscall(__NR_socket, 0x10, 3, 0);
    break;
  case 4:
    memcpy((void*)0x208a3fe0,
           "\x6c\x6f\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
           16);
    *(uint16_t*)0x208a3ff0 = 2;
    *(uint16_t*)0x208a3ff2 = 0;
    *(uint32_t*)0x208a3ff4 = htobe32(0);
    *(uint8_t*)0x208a3ff8 = 0;
    *(uint8_t*)0x208a3ff9 = 0;
    *(uint8_t*)0x208a3ffa = 0;
    *(uint8_t*)0x208a3ffb = 0;
    *(uint8_t*)0x208a3ffc = 0;
    *(uint8_t*)0x208a3ffd = 0;
    *(uint8_t*)0x208a3ffe = 0;
    *(uint8_t*)0x208a3fff = 0;
    syscall(__NR_ioctl, r[1], 0x8914, 0x208a3fe0);
    break;
  case 5:
    r[2] = syscall(__NR_socket, 0xa, 0x1000000000003, 4);
    break;
  case 6:
    memcpy((void*)0x202bf000,
           "\x73\x69\x74\x30\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
           16);
    *(uint32_t*)0x202bf010 = 0;
    *(uint8_t*)0x202bf014 = 0;
    *(uint8_t*)0x202bf015 = 0;
    *(uint8_t*)0x202bf016 = 0;
    *(uint8_t*)0x202bf017 = 0;
    *(uint8_t*)0x202bf018 = 0;
    *(uint8_t*)0x202bf019 = 0;
    *(uint8_t*)0x202bf01a = 0;
    *(uint8_t*)0x202bf01b = 0;
    *(uint8_t*)0x202bf01c = 0;
    *(uint8_t*)0x202bf01d = 0;
    *(uint8_t*)0x202bf01e = 0;
    *(uint8_t*)0x202bf01f = 0;
    *(uint8_t*)0x202bf020 = 0;
    *(uint8_t*)0x202bf021 = 0;
    *(uint8_t*)0x202bf022 = 0;
    *(uint8_t*)0x202bf023 = 0;
    *(uint8_t*)0x202bf024 = 0;
    *(uint8_t*)0x202bf025 = 0;
    *(uint8_t*)0x202bf026 = 0;
    *(uint8_t*)0x202bf027 = 0;
    if (syscall(__NR_ioctl, r[2], 0x8933, 0x202bf000) != -1)
      r[3] = *(uint32_t*)0x202bf010;
    break;
  case 7:
    *(uint8_t*)0x20d03fb0 = 0;
    *(uint8_t*)0x20d03fb1 = 0;
    *(uint8_t*)0x20d03fb2 = 0;
    *(uint8_t*)0x20d03fb3 = 0;
    *(uint8_t*)0x20d03fb4 = 0;
    *(uint8_t*)0x20d03fb5 = 0;
    *(uint8_t*)0x20d03fb6 = 0;
    *(uint8_t*)0x20d03fb7 = 0;
    *(uint8_t*)0x20d03fb8 = 0;
    *(uint8_t*)0x20d03fb9 = 0;
    *(uint8_t*)0x20d03fba = 0;
    *(uint8_t*)0x20d03fbb = 0;
    *(uint8_t*)0x20d03fbc = 0;
    *(uint8_t*)0x20d03fbd = 0;
    *(uint8_t*)0x20d03fbe = 0;
    *(uint8_t*)0x20d03fbf = 0;
    *(uint8_t*)0x20d03fc0 = 0;
    *(uint8_t*)0x20d03fc1 = 0;
    *(uint8_t*)0x20d03fc2 = 0;
    *(uint8_t*)0x20d03fc3 = 0;
    *(uint8_t*)0x20d03fc4 = 0;
    *(uint8_t*)0x20d03fc5 = 0;
    *(uint8_t*)0x20d03fc6 = 0;
    *(uint8_t*)0x20d03fc7 = 0;
    *(uint8_t*)0x20d03fc8 = 0;
    *(uint8_t*)0x20d03fc9 = 0;
    *(uint8_t*)0x20d03fca = 0;
    *(uint8_t*)0x20d03fcb = 0;
    *(uint8_t*)0x20d03fcc = 0;
    *(uint8_t*)0x20d03fcd = 0;
    *(uint8_t*)0x20d03fce = 0;
    *(uint8_t*)0x20d03fcf = 0;
    *(uint8_t*)0x20d03fd0 = 0xfe;
    *(uint8_t*)0x20d03fd1 = 0x80;
    *(uint8_t*)0x20d03fd2 = 0;
    *(uint8_t*)0x20d03fd3 = 0;
    *(uint8_t*)0x20d03fd4 = 0;
    *(uint8_t*)0x20d03fd5 = 0;
    *(uint8_t*)0x20d03fd6 = 0;
    *(uint8_t*)0x20d03fd7 = 0;
    *(uint8_t*)0x20d03fd8 = 0;
    *(uint8_t*)0x20d03fd9 = 0;
    *(uint8_t*)0x20d03fda = 0;
    *(uint8_t*)0x20d03fdb = 0;
    *(uint8_t*)0x20d03fdc = 0;
    *(uint8_t*)0x20d03fdd = 0;
    *(uint8_t*)0x20d03fde = 0;
    *(uint8_t*)0x20d03fdf = 0xaa;
    *(uint32_t*)0x20d03fe0 = 0;
    *(uint16_t*)0x20d03fe4 = 0;
    *(uint16_t*)0x20d03fe6 = 0;
    *(uint32_t*)0x20d03fe8 = 0;
    *(uint64_t*)0x20d03ff0 = 4;
    *(uint32_t*)0x20d03ff8 = 0xc100bf;
    *(uint32_t*)0x20d03ffc = r[3];
    syscall(__NR_ioctl, r[2], 0x890b, 0x20d03fb0);
    break;
  case 8:
    r[4] = syscall(__NR_socket, 0xa, 1, 0);
    break;
  case 9:
    *(uint64_t*)0x20fd7000 = htobe64(0);
    *(uint64_t*)0x20fd7008 = htobe64(1);
    *(uint8_t*)0x20fd7010 = 0xfe;
    *(uint8_t*)0x20fd7011 = 0x80;
    *(uint8_t*)0x20fd7012 = 0;
    *(uint8_t*)0x20fd7013 = 0;
    *(uint8_t*)0x20fd7014 = 0;
    *(uint8_t*)0x20fd7015 = 0;
    *(uint8_t*)0x20fd7016 = 0;
    *(uint8_t*)0x20fd7017 = 0;
    *(uint8_t*)0x20fd7018 = 0;
    *(uint8_t*)0x20fd7019 = 0;
    *(uint8_t*)0x20fd701a = 0;
    *(uint8_t*)0x20fd701b = 0;
    *(uint8_t*)0x20fd701c = 0;
    *(uint8_t*)0x20fd701d = 0;
    *(uint8_t*)0x20fd701e = 0;
    *(uint8_t*)0x20fd701f = 0xbb;
    *(uint8_t*)0x20fd7020 = -1;
    *(uint8_t*)0x20fd7021 = 1;
    *(uint8_t*)0x20fd7022 = 0;
    *(uint8_t*)0x20fd7023 = 0;
    *(uint8_t*)0x20fd7024 = 0;
    *(uint8_t*)0x20fd7025 = 0;
    *(uint8_t*)0x20fd7026 = 0;
    *(uint8_t*)0x20fd7027 = 0;
    *(uint8_t*)0x20fd7028 = 0;
    *(uint8_t*)0x20fd7029 = 0;
    *(uint8_t*)0x20fd702a = 0;
    *(uint8_t*)0x20fd702b = 0;
    *(uint8_t*)0x20fd702c = 0;
    *(uint8_t*)0x20fd702d = 0;
    *(uint8_t*)0x20fd702e = 0;
    *(uint8_t*)0x20fd702f = 1;
    *(uint32_t*)0x20fd7030 = 0;
    *(uint16_t*)0x20fd7034 = 0;
    *(uint16_t*)0x20fd7036 = 0x40;
    *(uint32_t*)0x20fd7038 = 0;
    *(uint64_t*)0x20fd7040 = 0;
    *(uint32_t*)0x20fd7048 = 0;
    *(uint32_t*)0x20fd704c = 1;
    syscall(__NR_ioctl, r[4], 0x890b, 0x20fd7000);
    break;
  }
}

void test()
{
  memset(r, -1, sizeof(r));
  execute(10);
}

int main()
{
  for (procid = 0; procid < 8; procid++) {
    if (fork() == 0) {
      for (;;) {
        setup_tun(procid, true);
        loop();
      }
    }
  }
  sleep(1000000);
  return 0;
}