// https://syzkaller.appspot.com/bug?id=253324b496b749185232dff7c28a7ffb42c377aa
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <arpa/inet.h>
#include <endian.h>
#include <errno.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/net.h>
#include <linux/tcp.h>
#include <net/if_arp.h>
#include <netinet/in.h>
#include <pthread.h>
#include <signal.h>
#include <stdarg.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/prctl.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <sys/wait.h>
#include <time.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);
}

#define BITMASK_LEN(type, bf_len) (type)((1ull << (bf_len)) - 1)

#define BITMASK_LEN_OFF(type, bf_off, bf_len)                                  \
  (type)(BITMASK_LEN(type, (bf_len)) << (bf_off))

#define STORE_BY_BITMASK(type, addr, val, bf_off, bf_len)                      \
  if ((bf_off) == 0 && (bf_len) == 0) {                                        \
    *(type*)(addr) = (type)(val);                                              \
  } else {                                                                     \
    type new_val = *(type*)(addr);                                             \
    new_val &= ~BITMASK_LEN_OFF(type, (bf_off), (bf_len));                     \
    new_val |= ((type)(val)&BITMASK_LEN(type, (bf_len))) << (bf_off);          \
    *(type*)(addr) = new_val;                                                  \
  }

struct csum_inet {
  uint32_t acc;
};

static void csum_inet_init(struct csum_inet* csum)
{
  csum->acc = 0;
}

static void csum_inet_update(struct csum_inet* csum, const uint8_t* data,
                             size_t length)
{
  if (length == 0)
    return;

  size_t i;
  for (i = 0; i < length - 1; i += 2)
    csum->acc += *(uint16_t*)&data[i];

  if (length & 1)
    csum->acc += (uint16_t)data[length - 1];

  while (csum->acc > 0xffff)
    csum->acc = (csum->acc & 0xffff) + (csum->acc >> 16);
}

static uint16_t csum_inet_digest(struct csum_inet* csum)
{
  return ~csum->acc;
}

static uint64_t current_time_ms()
{
  struct timespec ts;

  if (clock_gettime(CLOCK_MONOTONIC, &ts))
    fail("clock_gettime failed");
  return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;
}

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 int read_tun(char* data, int size)
{
  if (tunfd < 0)
    return -1;

  int rv = read(tunfd, data, size);
  if (rv < 0) {
    if (errno == EAGAIN)
      return -1;
    if (errno == EBADFD)
      return -1;
    fail("tun: read failed with %d", rv);
  }
  return rv;
}

#define MAX_FRAGS 4
struct vnet_fragmentation {
  uint32_t full;
  uint32_t count;
  uint32_t frags[MAX_FRAGS];
};

static uintptr_t syz_emit_ethernet(uintptr_t a0, uintptr_t a1, uintptr_t a2)
{
  if (tunfd < 0)
    return (uintptr_t)-1;

  uint32_t length = a0;
  char* data = (char*)a1;

  struct vnet_fragmentation* frags = (struct vnet_fragmentation*)a2;
  struct iovec vecs[MAX_FRAGS + 1];
  uint32_t nfrags = 0;
  if (!tun_frags_enabled || frags == NULL) {
    vecs[nfrags].iov_base = data;
    vecs[nfrags].iov_len = length;
    nfrags++;
  } else {
    bool full = true;
    uint32_t i, count = 0;
    full = frags->full;
    count = frags->count;
    if (count > MAX_FRAGS)
      count = MAX_FRAGS;
    for (i = 0; i < count && length != 0; i++) {
      uint32_t size = 0;
      size = frags->frags[i];
      if (size > length)
        size = length;
      vecs[nfrags].iov_base = data;
      vecs[nfrags].iov_len = size;
      nfrags++;
      data += size;
      length -= size;
    }
    if (length != 0 && (full || nfrags == 0)) {
      vecs[nfrags].iov_base = data;
      vecs[nfrags].iov_len = length;
      nfrags++;
    }
  }
  return writev(tunfd, vecs, nfrags);
}

static void flush_tun()
{
  char data[SYZ_TUN_MAX_PACKET_SIZE];
  while (read_tun(&data[0], sizeof(data)) != -1)
    ;
}

#define XT_TABLE_SIZE 1536
#define XT_MAX_ENTRIES 10

struct xt_counters {
  uint64_t pcnt, bcnt;
};

struct ipt_getinfo {
  char name[32];
  unsigned int valid_hooks;
  unsigned int hook_entry[5];
  unsigned int underflow[5];
  unsigned int num_entries;
  unsigned int size;
};

struct ipt_get_entries {
  char name[32];
  unsigned int size;
  void* entrytable[XT_TABLE_SIZE / sizeof(void*)];
};

struct ipt_replace {
  char name[32];
  unsigned int valid_hooks;
  unsigned int num_entries;
  unsigned int size;
  unsigned int hook_entry[5];
  unsigned int underflow[5];
  unsigned int num_counters;
  struct xt_counters* counters;
  char entrytable[XT_TABLE_SIZE];
};

struct ipt_table_desc {
  const char* name;
  struct ipt_getinfo info;
  struct ipt_replace replace;
};

static struct ipt_table_desc ipv4_tables[] = {
    {.name = "filter"}, {.name = "nat"},      {.name = "mangle"},
    {.name = "raw"},    {.name = "security"},
};

static struct ipt_table_desc ipv6_tables[] = {
    {.name = "filter"}, {.name = "nat"},      {.name = "mangle"},
    {.name = "raw"},    {.name = "security"},
};

#define IPT_BASE_CTL 64
#define IPT_SO_SET_REPLACE (IPT_BASE_CTL)
#define IPT_SO_GET_INFO (IPT_BASE_CTL)
#define IPT_SO_GET_ENTRIES (IPT_BASE_CTL + 1)

struct arpt_getinfo {
  char name[32];
  unsigned int valid_hooks;
  unsigned int hook_entry[3];
  unsigned int underflow[3];
  unsigned int num_entries;
  unsigned int size;
};

struct arpt_get_entries {
  char name[32];
  unsigned int size;
  void* entrytable[XT_TABLE_SIZE / sizeof(void*)];
};

struct arpt_replace {
  char name[32];
  unsigned int valid_hooks;
  unsigned int num_entries;
  unsigned int size;
  unsigned int hook_entry[3];
  unsigned int underflow[3];
  unsigned int num_counters;
  struct xt_counters* counters;
  char entrytable[XT_TABLE_SIZE];
};

struct arpt_table_desc {
  const char* name;
  struct arpt_getinfo info;
  struct arpt_replace replace;
};

static struct arpt_table_desc arpt_tables[] = {
    {.name = "filter"},
};

#define ARPT_BASE_CTL 96
#define ARPT_SO_SET_REPLACE (ARPT_BASE_CTL)
#define ARPT_SO_GET_INFO (ARPT_BASE_CTL)
#define ARPT_SO_GET_ENTRIES (ARPT_BASE_CTL + 1)

static void checkpoint_iptables(struct ipt_table_desc* tables, int num_tables,
                                int family, int level)
{
  struct ipt_get_entries entries;
  socklen_t optlen;
  int fd, i;

  fd = socket(family, SOCK_STREAM, IPPROTO_TCP);
  if (fd == -1)
    fail("socket(%d, SOCK_STREAM, IPPROTO_TCP)", family);
  for (i = 0; i < num_tables; i++) {
    struct ipt_table_desc* table = &tables[i];
    strcpy(table->info.name, table->name);
    strcpy(table->replace.name, table->name);
    optlen = sizeof(table->info);
    if (getsockopt(fd, level, IPT_SO_GET_INFO, &table->info, &optlen)) {
      switch (errno) {
      case EPERM:
      case ENOENT:
      case ENOPROTOOPT:
        continue;
      }
      fail("getsockopt(IPT_SO_GET_INFO)");
    }
    if (table->info.size > sizeof(table->replace.entrytable))
      fail("table size is too large: %u", table->info.size);
    if (table->info.num_entries > XT_MAX_ENTRIES)
      fail("too many counters: %u", table->info.num_entries);
    memset(&entries, 0, sizeof(entries));
    strcpy(entries.name, table->name);
    entries.size = table->info.size;
    optlen = sizeof(entries) - sizeof(entries.entrytable) + table->info.size;
    if (getsockopt(fd, level, IPT_SO_GET_ENTRIES, &entries, &optlen))
      fail("getsockopt(IPT_SO_GET_ENTRIES)");
    table->replace.valid_hooks = table->info.valid_hooks;
    table->replace.num_entries = table->info.num_entries;
    table->replace.size = table->info.size;
    memcpy(table->replace.hook_entry, table->info.hook_entry,
           sizeof(table->replace.hook_entry));
    memcpy(table->replace.underflow, table->info.underflow,
           sizeof(table->replace.underflow));
    memcpy(table->replace.entrytable, entries.entrytable, table->info.size);
  }
  close(fd);
}

static void reset_iptables(struct ipt_table_desc* tables, int num_tables,
                           int family, int level)
{
  struct xt_counters counters[XT_MAX_ENTRIES];
  struct ipt_get_entries entries;
  struct ipt_getinfo info;
  socklen_t optlen;
  int fd, i;

  fd = socket(family, SOCK_STREAM, IPPROTO_TCP);
  if (fd == -1)
    fail("socket(%d, SOCK_STREAM, IPPROTO_TCP)", family);
  for (i = 0; i < num_tables; i++) {
    struct ipt_table_desc* table = &tables[i];
    if (table->info.valid_hooks == 0)
      continue;
    memset(&info, 0, sizeof(info));
    strcpy(info.name, table->name);
    optlen = sizeof(info);
    if (getsockopt(fd, level, IPT_SO_GET_INFO, &info, &optlen))
      fail("getsockopt(IPT_SO_GET_INFO)");
    if (memcmp(&table->info, &info, sizeof(table->info)) == 0) {
      memset(&entries, 0, sizeof(entries));
      strcpy(entries.name, table->name);
      entries.size = table->info.size;
      optlen = sizeof(entries) - sizeof(entries.entrytable) + entries.size;
      if (getsockopt(fd, level, IPT_SO_GET_ENTRIES, &entries, &optlen))
        fail("getsockopt(IPT_SO_GET_ENTRIES)");
      if (memcmp(table->replace.entrytable, entries.entrytable,
                 table->info.size) == 0)
        continue;
    }
    table->replace.num_counters = info.num_entries;
    table->replace.counters = counters;
    optlen = sizeof(table->replace) - sizeof(table->replace.entrytable) +
             table->replace.size;
    if (setsockopt(fd, level, IPT_SO_SET_REPLACE, &table->replace, optlen))
      fail("setsockopt(IPT_SO_SET_REPLACE)");
  }
  close(fd);
}

static void checkpoint_arptables(void)
{
  struct arpt_get_entries entries;
  socklen_t optlen;
  unsigned i;
  int fd;

  fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  if (fd == -1)
    fail("socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)");
  for (i = 0; i < sizeof(arpt_tables) / sizeof(arpt_tables[0]); i++) {
    struct arpt_table_desc* table = &arpt_tables[i];
    strcpy(table->info.name, table->name);
    strcpy(table->replace.name, table->name);
    optlen = sizeof(table->info);
    if (getsockopt(fd, SOL_IP, ARPT_SO_GET_INFO, &table->info, &optlen)) {
      switch (errno) {
      case EPERM:
      case ENOENT:
      case ENOPROTOOPT:
        continue;
      }
      fail("getsockopt(ARPT_SO_GET_INFO)");
    }
    if (table->info.size > sizeof(table->replace.entrytable))
      fail("table size is too large: %u", table->info.size);
    if (table->info.num_entries > XT_MAX_ENTRIES)
      fail("too many counters: %u", table->info.num_entries);
    memset(&entries, 0, sizeof(entries));
    strcpy(entries.name, table->name);
    entries.size = table->info.size;
    optlen = sizeof(entries) - sizeof(entries.entrytable) + table->info.size;
    if (getsockopt(fd, SOL_IP, ARPT_SO_GET_ENTRIES, &entries, &optlen))
      fail("getsockopt(ARPT_SO_GET_ENTRIES)");
    table->replace.valid_hooks = table->info.valid_hooks;
    table->replace.num_entries = table->info.num_entries;
    table->replace.size = table->info.size;
    memcpy(table->replace.hook_entry, table->info.hook_entry,
           sizeof(table->replace.hook_entry));
    memcpy(table->replace.underflow, table->info.underflow,
           sizeof(table->replace.underflow));
    memcpy(table->replace.entrytable, entries.entrytable, table->info.size);
  }
  close(fd);
}

static void reset_arptables()
{
  struct xt_counters counters[XT_MAX_ENTRIES];
  struct arpt_get_entries entries;
  struct arpt_getinfo info;
  socklen_t optlen;
  unsigned i;
  int fd;

  fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  if (fd == -1)
    fail("socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)");
  for (i = 0; i < sizeof(arpt_tables) / sizeof(arpt_tables[0]); i++) {
    struct arpt_table_desc* table = &arpt_tables[i];
    if (table->info.valid_hooks == 0)
      continue;
    memset(&info, 0, sizeof(info));
    strcpy(info.name, table->name);
    optlen = sizeof(info);
    if (getsockopt(fd, SOL_IP, ARPT_SO_GET_INFO, &info, &optlen))
      fail("getsockopt(ARPT_SO_GET_INFO)");
    if (memcmp(&table->info, &info, sizeof(table->info)) == 0) {
      memset(&entries, 0, sizeof(entries));
      strcpy(entries.name, table->name);
      entries.size = table->info.size;
      optlen = sizeof(entries) - sizeof(entries.entrytable) + entries.size;
      if (getsockopt(fd, SOL_IP, ARPT_SO_GET_ENTRIES, &entries, &optlen))
        fail("getsockopt(ARPT_SO_GET_ENTRIES)");
      if (memcmp(table->replace.entrytable, entries.entrytable,
                 table->info.size) == 0)
        continue;
    }
    table->replace.num_counters = info.num_entries;
    table->replace.counters = counters;
    optlen = sizeof(table->replace) - sizeof(table->replace.entrytable) +
             table->replace.size;
    if (setsockopt(fd, SOL_IP, ARPT_SO_SET_REPLACE, &table->replace, optlen))
      fail("setsockopt(ARPT_SO_SET_REPLACE)");
  }
  close(fd);
}

static void checkpoint_net_namespace(void)
{
  checkpoint_arptables();
  checkpoint_iptables(ipv4_tables, sizeof(ipv4_tables) / sizeof(ipv4_tables[0]),
                      AF_INET, SOL_IP);
  checkpoint_iptables(ipv6_tables, sizeof(ipv6_tables) / sizeof(ipv6_tables[0]),
                      AF_INET6, SOL_IPV6);
}

static void reset_net_namespace(void)
{
  reset_arptables();
  reset_iptables(ipv4_tables, sizeof(ipv4_tables) / sizeof(ipv4_tables[0]),
                 AF_INET, SOL_IP);
  reset_iptables(ipv6_tables, sizeof(ipv6_tables) / sizeof(ipv6_tables[0]),
                 AF_INET6, SOL_IPV6);
}

static void test();

void loop()
{
  int iter;
  checkpoint_net_namespace();
  for (iter = 0;; iter++) {
    int pid = fork();
    if (pid < 0)
      fail("loop fork failed");
    if (pid == 0) {
      prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
      setpgrp();
      flush_tun();
      test();
      doexit(0);
    }
    int status = 0;
    uint64_t start = current_time_ms();
    for (;;) {
      int res = waitpid(-1, &status, __WALL | WNOHANG);
      if (res == pid)
        break;
      usleep(1000);
      if (current_time_ms() - start > 5 * 1000) {
        kill(-pid, SIGKILL);
        kill(pid, SIGKILL);
        while (waitpid(-1, &status, __WALL) != pid) {
        }
        break;
      }
    }
    reset_net_namespace();
  }
}

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 int collide;

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);
        if (collide && call % 2)
          break;
        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;
      }
    }
  }
}

#ifndef __NR_bpf
#define __NR_bpf 321
#endif

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:
    *(uint32_t*)0x20000000 = 0xe8;
    if (syscall(__NR_getsockopt, -1, 0, 0x11, 0x20000f18, 0x20000000) != -1)
      r[0] = *(uint32_t*)0x20000f48;
    break;
  case 2:
    *(uint16_t*)0x20002000 = 0x1d;
    *(uint32_t*)0x20002004 = r[0];
    *(uint32_t*)0x20002008 = 0;
    *(uint32_t*)0x2000200c = 0;
    syscall(__NR_connect, -1, 0x20002000, 0xfffffffffffffdec);
    break;
  case 3:
    r[1] = syscall(__NR_socket, 2, 1, 0);
    break;
  case 4:
    *(uint16_t*)0x20c6fff0 = 2;
    *(uint16_t*)0x20c6fff2 = htobe16(0x4e23 + procid * 4);
    *(uint8_t*)0x20c6fff4 = 0xac;
    *(uint8_t*)0x20c6fff5 = 0x14;
    *(uint8_t*)0x20c6fff6 = 0 + procid * 1;
    *(uint8_t*)0x20c6fff7 = 0x15;
    *(uint8_t*)0x20c6fff8 = 0;
    *(uint8_t*)0x20c6fff9 = 0;
    *(uint8_t*)0x20c6fffa = 0;
    *(uint8_t*)0x20c6fffb = 0;
    *(uint8_t*)0x20c6fffc = 0;
    *(uint8_t*)0x20c6fffd = 0;
    *(uint8_t*)0x20c6fffe = 0;
    *(uint8_t*)0x20c6ffff = 0;
    syscall(__NR_connect, r[1], 0x20c6fff0, 0x10);
    break;
  case 5:
    *(uint16_t*)0x20e5b000 = 2;
    *(uint16_t*)0x20e5b002 = htobe16(0x4e20 + procid * 4);
    *(uint32_t*)0x20e5b004 = htobe32(0xe0000001);
    *(uint8_t*)0x20e5b008 = 0;
    *(uint8_t*)0x20e5b009 = 0;
    *(uint8_t*)0x20e5b00a = 0;
    *(uint8_t*)0x20e5b00b = 0;
    *(uint8_t*)0x20e5b00c = 0;
    *(uint8_t*)0x20e5b00d = 0;
    *(uint8_t*)0x20e5b00e = 0;
    *(uint8_t*)0x20e5b00f = 0;
    syscall(__NR_bind, r[1], 0x20e5b000, 0x10);
    break;
  case 6:
    *(uint16_t*)0x20ccb000 = 2;
    *(uint16_t*)0x20ccb002 = htobe16(0x4e20 + procid * 4);
    *(uint32_t*)0x20ccb004 = htobe32(0);
    *(uint8_t*)0x20ccb008 = 0;
    *(uint8_t*)0x20ccb009 = 0;
    *(uint8_t*)0x20ccb00a = 0;
    *(uint8_t*)0x20ccb00b = 0;
    *(uint8_t*)0x20ccb00c = 0;
    *(uint8_t*)0x20ccb00d = 0;
    *(uint8_t*)0x20ccb00e = 0;
    *(uint8_t*)0x20ccb00f = 0;
    syscall(__NR_connect, r[1], 0x20ccb000, 0x10);
    break;
  case 7:
    *(uint32_t*)0x20eb0fb8 = 1;
    *(uint32_t*)0x20eb0fbc = 3;
    *(uint64_t*)0x20eb0fc0 = 0x209ff000;
    *(uint64_t*)0x20eb0fc8 = 0x202bf000;
    *(uint32_t*)0x20eb0fd0 = 4;
    *(uint32_t*)0x20eb0fd4 = 0x38b;
    *(uint64_t*)0x20eb0fd8 = 0x206ab000;
    *(uint32_t*)0x20eb0fe0 = 0;
    *(uint32_t*)0x20eb0fe4 = 0;
    *(uint8_t*)0x20eb0fe8 = 0;
    *(uint8_t*)0x20eb0fe9 = 0;
    *(uint8_t*)0x20eb0fea = 0;
    *(uint8_t*)0x20eb0feb = 0;
    *(uint8_t*)0x20eb0fec = 0;
    *(uint8_t*)0x20eb0fed = 0;
    *(uint8_t*)0x20eb0fee = 0;
    *(uint8_t*)0x20eb0fef = 0;
    *(uint8_t*)0x20eb0ff0 = 0;
    *(uint8_t*)0x20eb0ff1 = 0;
    *(uint8_t*)0x20eb0ff2 = 0;
    *(uint8_t*)0x20eb0ff3 = 0;
    *(uint8_t*)0x20eb0ff4 = 0;
    *(uint8_t*)0x20eb0ff5 = 0;
    *(uint8_t*)0x20eb0ff6 = 0;
    *(uint8_t*)0x20eb0ff7 = 0;
    *(uint32_t*)0x20eb0ff8 = 0;
    *(uint8_t*)0x209ff000 = 0x18;
    STORE_BY_BITMASK(uint8_t, 0x209ff001, 0, 0, 4);
    STORE_BY_BITMASK(uint8_t, 0x209ff001, 0, 4, 4);
    *(uint16_t*)0x209ff002 = 0;
    *(uint32_t*)0x209ff004 = 0x80000001;
    *(uint8_t*)0x209ff008 = 0;
    *(uint8_t*)0x209ff009 = 0;
    *(uint16_t*)0x209ff00a = 0;
    *(uint32_t*)0x209ff00c = 0;
    *(uint8_t*)0x209ff010 = 0x95;
    *(uint8_t*)0x209ff011 = 0;
    *(uint16_t*)0x209ff012 = 0;
    *(uint32_t*)0x209ff014 = 0;
    memcpy((void*)0x202bf000, "syzkaller", 10);
    r[2] = syscall(__NR_bpf, 5, 0x20eb0fb8, 0x48);
    break;
  case 8:
    r[3] = syscall(__NR_socket, 0x29, 2, 0);
    break;
  case 9:
    *(uint32_t*)0x2031aff8 = r[1];
    *(uint32_t*)0x2031affc = r[2];
    syscall(__NR_ioctl, r[3], 0x89e0, 0x2031aff8);
    break;
  case 10:
    *(uint64_t*)0x207ae000 = 0x20cab000;
    *(uint32_t*)0x207ae008 = 0x3a;
    *(uint64_t*)0x207ae010 = 0x20294000;
    *(uint64_t*)0x207ae018 = 1;
    *(uint64_t*)0x207ae020 = 0x20c16fe0;
    *(uint64_t*)0x207ae028 = 0;
    *(uint32_t*)0x207ae030 = 0;
    *(uint16_t*)0x20cab000 = 0x18;
    *(uint32_t*)0x20cab002 = 1;
    *(uint32_t*)0x20cab006 = 0;
    *(uint32_t*)0x20cab00a = -1;
    *(uint32_t*)0x20cab00e = 0;
    *(uint32_t*)0x20cab012 = 0;
    *(uint32_t*)0x20cab016 = 0;
    *(uint32_t*)0x20cab01a = 0;
    *(uint16_t*)0x20cab01e = 0xa;
    *(uint16_t*)0x20cab020 = 0;
    *(uint32_t*)0x20cab022 = 0;
    *(uint8_t*)0x20cab026 = -1;
    *(uint8_t*)0x20cab027 = 1;
    *(uint8_t*)0x20cab028 = 0;
    *(uint8_t*)0x20cab029 = 0;
    *(uint8_t*)0x20cab02a = 0;
    *(uint8_t*)0x20cab02b = 0;
    *(uint8_t*)0x20cab02c = 0;
    *(uint8_t*)0x20cab02d = 0;
    *(uint8_t*)0x20cab02e = 0;
    *(uint8_t*)0x20cab02f = 0;
    *(uint8_t*)0x20cab030 = 0;
    *(uint8_t*)0x20cab031 = 0;
    *(uint8_t*)0x20cab032 = 0;
    *(uint8_t*)0x20cab033 = 0;
    *(uint8_t*)0x20cab034 = 0;
    *(uint8_t*)0x20cab035 = 1;
    *(uint32_t*)0x20cab036 = 0;
    *(uint64_t*)0x20294000 = 0x20831000;
    *(uint64_t*)0x20294008 = 0;
    syscall(__NR_sendmsg, r[3], 0x207ae000, 0);
    break;
  case 11:
    *(uint32_t*)0x20000000 = 0;
    *(uint16_t*)0x20000008 = 2;
    *(uint16_t*)0x2000000a = htobe16(0x4e20 + procid * 4);
    *(uint32_t*)0x2000000c = htobe32(0x7f000001);
    *(uint8_t*)0x20000010 = 0;
    *(uint8_t*)0x20000011 = 0;
    *(uint8_t*)0x20000012 = 0;
    *(uint8_t*)0x20000013 = 0;
    *(uint8_t*)0x20000014 = 0;
    *(uint8_t*)0x20000015 = 0;
    *(uint8_t*)0x20000016 = 0;
    *(uint8_t*)0x20000017 = 0;
    *(uint64_t*)0x20000018 = 0;
    *(uint64_t*)0x20000020 = 0;
    *(uint64_t*)0x20000028 = 0;
    *(uint64_t*)0x20000030 = 0;
    *(uint64_t*)0x20000038 = 0;
    *(uint64_t*)0x20000040 = 0;
    *(uint64_t*)0x20000048 = 0;
    *(uint64_t*)0x20000050 = 0;
    *(uint64_t*)0x20000058 = 0;
    *(uint64_t*)0x20000060 = 0;
    *(uint64_t*)0x20000068 = 0;
    *(uint64_t*)0x20000070 = 0;
    *(uint64_t*)0x20000078 = 0;
    *(uint64_t*)0x20000080 = 0;
    *(uint64_t*)0x20000088 = 0;
    *(uint16_t*)0x20000090 = 0x100;
    *(uint16_t*)0x20000092 = 0x90a0;
    *(uint32_t*)0x20000ffc = 0x98;
    if (syscall(__NR_getsockopt, 0xffffff9c, 0x84, 0x1f, 0x20000000,
                0x20000ffc) != -1)
      r[4] = *(uint32_t*)0x20000000;
    break;
  case 12:
    *(uint32_t*)0x20000fdf = r[4];
    *(uint32_t*)0x20000fe3 = 0;
    *(uint32_t*)0x2043dffc = 8;
    syscall(__NR_getsockopt, -1, 0x84, 0x1a, 0x20000fdf, 0x2043dffc);
    break;
  case 13:
    *(uint64_t*)0x20008000 = 0x2000eff4;
    *(uint32_t*)0x20008008 = 0xc;
    *(uint64_t*)0x20008010 = 0x20007ff0;
    *(uint64_t*)0x20008018 = 1;
    *(uint64_t*)0x20008020 = 0;
    *(uint64_t*)0x20008028 = 0;
    *(uint32_t*)0x20008030 = 0;
    *(uint16_t*)0x2000eff4 = 0x10;
    *(uint16_t*)0x2000eff6 = 0x4050;
    *(uint32_t*)0x2000eff8 = 0;
    *(uint32_t*)0x2000effc = 0;
    *(uint64_t*)0x20007ff0 = 0x20014000;
    *(uint64_t*)0x20007ff8 = 0x18;
    *(uint32_t*)0x20014000 = 0x18;
    *(uint16_t*)0x20014004 = 0x27;
    *(uint16_t*)0x20014006 = 0x829;
    *(uint32_t*)0x20014008 = 0;
    *(uint32_t*)0x2001400c = 0;
    *(uint8_t*)0x20014010 = 2;
    *(uint8_t*)0x20014011 = 0;
    *(uint16_t*)0x20014012 = 0;
    *(uint16_t*)0x20014014 = 4;
    *(uint16_t*)0x20014016 = 0;
    syscall(__NR_sendmsg, -1, 0x20008000, 0);
    break;
  case 14:
    *(uint8_t*)0x20004fb1 = 1;
    *(uint8_t*)0x20004fb2 = 0x80;
    *(uint8_t*)0x20004fb3 = 0xc2;
    *(uint8_t*)0x20004fb4 = 0;
    *(uint8_t*)0x20004fb5 = 0;
    *(uint8_t*)0x20004fb6 = 0;
    *(uint8_t*)0x20004fb7 = 0xaa;
    *(uint8_t*)0x20004fb8 = 0xaa;
    *(uint8_t*)0x20004fb9 = 0xaa;
    *(uint8_t*)0x20004fba = 0xaa;
    *(uint8_t*)0x20004fbb = 0;
    *(uint8_t*)0x20004fbc = 0;
    *(uint16_t*)0x20004fbd = htobe16(0x800);
    STORE_BY_BITMASK(uint8_t, 0x20004fbf, 5, 0, 4);
    STORE_BY_BITMASK(uint8_t, 0x20004fbf, 4, 4, 4);
    STORE_BY_BITMASK(uint8_t, 0x20004fc0, 0, 0, 2);
    STORE_BY_BITMASK(uint8_t, 0x20004fc0, 0, 2, 6);
    *(uint16_t*)0x20004fc1 = htobe16(0x1c);
    *(uint16_t*)0x20004fc3 = 0;
    *(uint16_t*)0x20004fc5 = htobe16(0);
    *(uint8_t*)0x20004fc7 = 0;
    *(uint8_t*)0x20004fc8 = 0x11;
    *(uint16_t*)0x20004fc9 = 0;
    *(uint8_t*)0x20004fcb = 0xac;
    *(uint8_t*)0x20004fcc = 0x14;
    *(uint8_t*)0x20004fcd = 0;
    *(uint8_t*)0x20004fce = 0xaa;
    *(uint32_t*)0x20004fcf = htobe32(0xe0000001);
    *(uint16_t*)0x20004fd3 = 0;
    *(uint16_t*)0x20004fd5 = htobe16(0x4e23 + procid * 4);
    *(uint16_t*)0x20004fd7 = htobe16(8);
    *(uint16_t*)0x20004fd9 = 0;
    struct csum_inet csum_1;
    csum_inet_init(&csum_1);
    csum_inet_update(&csum_1, (const uint8_t*)0x20004fcb, 4);
    csum_inet_update(&csum_1, (const uint8_t*)0x20004fcf, 4);
    uint16_t csum_1_chunk_2 = 0x1100;
    csum_inet_update(&csum_1, (const uint8_t*)&csum_1_chunk_2, 2);
    uint16_t csum_1_chunk_3 = 0x800;
    csum_inet_update(&csum_1, (const uint8_t*)&csum_1_chunk_3, 2);
    csum_inet_update(&csum_1, (const uint8_t*)0x20004fd3, 8);
    *(uint16_t*)0x20004fd9 = csum_inet_digest(&csum_1);
    struct csum_inet csum_2;
    csum_inet_init(&csum_2);
    csum_inet_update(&csum_2, (const uint8_t*)0x20004fbf, 20);
    *(uint16_t*)0x20004fc9 = csum_inet_digest(&csum_2);
    syz_emit_ethernet(0x2a, 0x20004fb1, 0x20000000);
    break;
  }
}

void test()
{
  memset(r, -1, sizeof(r));
  execute(15);
  collide = 1;
  execute(15);
}

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