syzkaller-repros/linux/0b533a58216b026ac76333a0b2a91e65a98bdc81.c

// KMSAN: uninit-value in tcp_parse_options
// https://syzkaller.appspot.com/bug?id=0b533a58216b026ac76333a0b2a91e65a98bdc81
// status:fixed
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <arpa/inet.h>
#include <dirent.h>
#include <endian.h>
#include <errno.h>
#include <errno.h>
#include <errno.h>
#include <errno.h>
#include <fcntl.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 <sched.h>
#include <signal.h>
#include <signal.h>
#include <stdarg.h>
#include <stdarg.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdio.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/mount.h>
#include <sys/prctl.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <sys/wait.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 <errno.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.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 exitf(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(kRetryStatus);
}

#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 use_temporary_dir()
{
  char tmpdir_template[] = "./syzkaller.XXXXXX";
  char* tmpdir = mkdtemp(tmpdir_template);
  if (!tmpdir)
    fail("failed to mkdtemp");
  if (chmod(tmpdir, 0777))
    fail("failed to chmod");
  if (chdir(tmpdir))
    fail("failed to chdir");
}

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);
  va_end(args);
  rv = system(command);
  if (rv) {
    if (panic)
      fail("command '%s' failed: %d", &command[0], rv);
  }
}

static int tunfd = -1;
static int tun_frags_enabled;

#define SYZ_TUN_MAX_PACKET_SIZE 1000

#define TUN_IFACE "syz_tun"

#define LOCAL_MAC "aa:aa:aa:aa:aa:aa"
#define REMOTE_MAC "aa:aa:aa:aa:aa:bb"

#define LOCAL_IPV4 "172.20.20.170"
#define REMOTE_IPV4 "172.20.20.187"

#define LOCAL_IPV6 "fe80::aa"
#define REMOTE_IPV6 "fe80::bb"

#define IFF_NAPI 0x0010
#define IFF_NAPI_FRAGS 0x0020

static void initialize_tun(void)
{
  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;
  }
  const int kTunFd = 252;
  if (dup2(tunfd, kTunFd) < 0)
    fail("dup2(tunfd, kTunFd) failed");
  close(tunfd);
  tunfd = kTunFd;

  struct ifreq ifr;
  memset(&ifr, 0, sizeof(ifr));
  strncpy(ifr.ifr_name, TUN_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;

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

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

  execute_command(1, "ip link set dev %s address %s", TUN_IFACE, LOCAL_MAC);
  execute_command(1, "ip addr add %s/24 dev %s", LOCAL_IPV4, TUN_IFACE);
  execute_command(1, "ip -6 addr add %s/120 dev %s", LOCAL_IPV6, TUN_IFACE);
  execute_command(1, "ip neigh add %s lladdr %s dev %s nud permanent",
                  REMOTE_IPV4, REMOTE_MAC, TUN_IFACE);
  execute_command(1, "ip -6 neigh add %s lladdr %s dev %s nud permanent",
                  REMOTE_IPV6, REMOTE_MAC, TUN_IFACE);
  execute_command(1, "ip link set dev %s up", TUN_IFACE);
}

#define DEV_IPV4 "172.20.20.%d"
#define DEV_IPV6 "fe80::%02hx"
#define DEV_MAC "aa:aa:aa:aa:aa:%02hx"

static void initialize_netdevices(void)
{
  unsigned i;
  const char* devtypes[] = {"ip6gretap", "bridge", "vcan",
                            "bond",      "veth",   "team"};
  const char* devnames[] = {
      "lo",      "sit0",    "bridge0",  "vcan0",   "tunl0",   "gre0",
      "gretap0", "ip_vti0", "ip6_vti0", "ip6tnl0", "ip6gre0", "ip6gretap0",
      "erspan0", "bond0",   "veth0",    "veth1",   "team0"};

  for (i = 0; i < sizeof(devtypes) / (sizeof(devtypes[0])); i++)
    execute_command(0, "ip link add dev %s0 type %s", devtypes[i], devtypes[i]);
  execute_command(0, "ip link add dev veth1 type veth");
  for (i = 0; i < sizeof(devnames) / (sizeof(devnames[0])); i++) {
    char addr[32];
    snprintf_check(addr, sizeof(addr), DEV_IPV4, i + 10);
    execute_command(0, "ip -4 addr add %s/24 dev %s", addr, devnames[i]);
    snprintf_check(addr, sizeof(addr), DEV_IPV6, i + 10);
    execute_command(0, "ip -6 addr add %s/120 dev %s", addr, devnames[i]);
    snprintf_check(addr, sizeof(addr), DEV_MAC, i + 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 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)
    ;
}

static bool write_file(const char* file, const char* what, ...)
{
  char buf[1024];
  va_list args;
  va_start(args, what);
  vsnprintf(buf, sizeof(buf), what, args);
  va_end(args);
  buf[sizeof(buf) - 1] = 0;
  int len = strlen(buf);

  int fd = open(file, O_WRONLY | O_CLOEXEC);
  if (fd == -1)
    return false;
  if (write(fd, buf, len) != len) {
    int err = errno;
    close(fd);
    errno = err;
    return false;
  }
  close(fd);
  return true;
}

static void setup_cgroups()
{
  if (mkdir("/syzcgroup", 0777)) {
  }
  if (mkdir("/syzcgroup/unified", 0777)) {
  }
  if (mount("none", "/syzcgroup/unified", "cgroup2", 0, NULL)) {
  }
  if (chmod("/syzcgroup/unified", 0777)) {
  }
  if (!write_file("/syzcgroup/unified/cgroup.subtree_control",
                  "+cpu +memory +io +pids +rdma")) {
  }
  if (mkdir("/syzcgroup/cpu", 0777)) {
  }
  if (mount("none", "/syzcgroup/cpu", "cgroup", 0,
            "cpuset,cpuacct,perf_event,hugetlb")) {
  }
  if (!write_file("/syzcgroup/cpu/cgroup.clone_children", "1")) {
  }
  if (chmod("/syzcgroup/cpu", 0777)) {
  }
  if (mkdir("/syzcgroup/net", 0777)) {
  }
  if (mount("none", "/syzcgroup/net", "cgroup", 0,
            "net_cls,net_prio,devices,freezer")) {
  }
  if (chmod("/syzcgroup/net", 0777)) {
  }
}

static void setup_binfmt_misc()
{
  if (!write_file("/proc/sys/fs/binfmt_misc/register",
                  ":syz0:M:0:syz0::./file0:")) {
  }
  if (!write_file("/proc/sys/fs/binfmt_misc/register",
                  ":syz1:M:1:yz1::./file0:POC")) {
  }
}

static void loop();

static void sandbox_common()
{
  prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
  setpgrp();
  setsid();

  struct rlimit rlim;
  rlim.rlim_cur = rlim.rlim_max = 128 << 20;
  setrlimit(RLIMIT_AS, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 8 << 20;
  setrlimit(RLIMIT_MEMLOCK, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 32 << 20;
  setrlimit(RLIMIT_FSIZE, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 1 << 20;
  setrlimit(RLIMIT_STACK, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 0;
  setrlimit(RLIMIT_CORE, &rlim);

  if (unshare(CLONE_NEWNS)) {
  }
  if (unshare(CLONE_NEWIPC)) {
  }
  if (unshare(0x02000000)) {
  }
  if (unshare(CLONE_NEWUTS)) {
  }
  if (unshare(CLONE_SYSVSEM)) {
  }
}

static int do_sandbox_none(void)
{
  if (unshare(CLONE_NEWPID)) {
  }
  int pid = fork();
  if (pid < 0)
    fail("sandbox fork failed");
  if (pid)
    return pid;

  setup_cgroups();
  setup_binfmt_misc();
  sandbox_common();
  if (unshare(CLONE_NEWNET)) {
  }
  initialize_tun();
  initialize_netdevices();

  loop();
  doexit(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);
}
#include <linux/if.h>
#include <linux/netfilter_bridge/ebtables.h>

struct ebt_table_desc {
  const char* name;
  struct ebt_replace replace;
  char entrytable[XT_TABLE_SIZE];
};

static struct ebt_table_desc ebt_tables[] = {
    {.name = "filter"}, {.name = "nat"}, {.name = "broute"},
};

static void checkpoint_ebtables(void)
{
  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(ebt_tables) / sizeof(ebt_tables[0]); i++) {
    struct ebt_table_desc* table = &ebt_tables[i];
    strcpy(table->replace.name, table->name);
    optlen = sizeof(table->replace);
    if (getsockopt(fd, SOL_IP, EBT_SO_GET_INIT_INFO, &table->replace,
                   &optlen)) {
      switch (errno) {
      case EPERM:
      case ENOENT:
      case ENOPROTOOPT:
        continue;
      }
      fail("getsockopt(EBT_SO_GET_INIT_INFO)");
    }
    if (table->replace.entries_size > sizeof(table->entrytable))
      fail("table size is too large: %u", table->replace.entries_size);
    table->replace.num_counters = 0;
    table->replace.entries = table->entrytable;
    optlen = sizeof(table->replace) + table->replace.entries_size;
    if (getsockopt(fd, SOL_IP, EBT_SO_GET_INIT_ENTRIES, &table->replace,
                   &optlen))
      fail("getsockopt(EBT_SO_GET_INIT_ENTRIES)");
  }
  close(fd);
}

static void reset_ebtables()
{
  struct ebt_replace replace;
  char entrytable[XT_TABLE_SIZE];
  socklen_t optlen;
  unsigned i, j, h;
  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(ebt_tables) / sizeof(ebt_tables[0]); i++) {
    struct ebt_table_desc* table = &ebt_tables[i];
    if (table->replace.valid_hooks == 0)
      continue;
    memset(&replace, 0, sizeof(replace));
    strcpy(replace.name, table->name);
    optlen = sizeof(replace);
    if (getsockopt(fd, SOL_IP, EBT_SO_GET_INFO, &replace, &optlen))
      fail("getsockopt(EBT_SO_GET_INFO)");
    replace.num_counters = 0;
    table->replace.entries = 0;
    for (h = 0; h < NF_BR_NUMHOOKS; h++)
      table->replace.hook_entry[h] = 0;
    if (memcmp(&table->replace, &replace, sizeof(table->replace)) == 0) {
      memset(&entrytable, 0, sizeof(entrytable));
      replace.entries = entrytable;
      optlen = sizeof(replace) + replace.entries_size;
      if (getsockopt(fd, SOL_IP, EBT_SO_GET_ENTRIES, &replace, &optlen))
        fail("getsockopt(EBT_SO_GET_ENTRIES)");
      if (memcmp(table->entrytable, entrytable, replace.entries_size) == 0)
        continue;
    }
    for (j = 0, h = 0; h < NF_BR_NUMHOOKS; h++) {
      if (table->replace.valid_hooks & (1 << h)) {
        table->replace.hook_entry[h] =
            (struct ebt_entries*)table->entrytable + j;
        j++;
      }
    }
    table->replace.entries = table->entrytable;
    optlen = sizeof(table->replace) + table->replace.entries_size;
    if (setsockopt(fd, SOL_IP, EBT_SO_SET_ENTRIES, &table->replace, optlen))
      fail("setsockopt(EBT_SO_SET_ENTRIES)");
  }
  close(fd);
}

static void checkpoint_net_namespace(void)
{
  checkpoint_ebtables();
  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_ebtables();
  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 remove_dir(const char* dir)
{
  DIR* dp;
  struct dirent* ep;
  int iter = 0;
retry:
  while (umount2(dir, MNT_DETACH) == 0) {
  }
  dp = opendir(dir);
  if (dp == NULL) {
    if (errno == EMFILE) {
      exitf("opendir(%s) failed due to NOFILE, exiting", dir);
    }
    exitf("opendir(%s) failed", dir);
  }
  while ((ep = readdir(dp))) {
    if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0)
      continue;
    char filename[FILENAME_MAX];
    snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name);
    struct stat st;
    if (lstat(filename, &st))
      exitf("lstat(%s) failed", filename);
    if (S_ISDIR(st.st_mode)) {
      remove_dir(filename);
      continue;
    }
    int i;
    for (i = 0;; i++) {
      if (unlink(filename) == 0)
        break;
      if (errno == EROFS) {
        break;
      }
      if (errno != EBUSY || i > 100)
        exitf("unlink(%s) failed", filename);
      if (umount2(filename, MNT_DETACH))
        exitf("umount(%s) failed", filename);
    }
  }
  closedir(dp);
  int i;
  for (i = 0;; i++) {
    if (rmdir(dir) == 0)
      break;
    if (i < 100) {
      if (errno == EROFS) {
        break;
      }
      if (errno == EBUSY) {
        if (umount2(dir, MNT_DETACH))
          exitf("umount(%s) failed", dir);
        continue;
      }
      if (errno == ENOTEMPTY) {
        if (iter < 100) {
          iter++;
          goto retry;
        }
      }
    }
    exitf("rmdir(%s) failed", dir);
  }
}

static void execute_one();
extern unsigned long long procid;

static void loop()
{
  checkpoint_net_namespace();
  char cgroupdir[64];
  snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/unified/syz%llu", procid);
  char cgroupdir_cpu[64];
  snprintf(cgroupdir_cpu, sizeof(cgroupdir_cpu), "/syzcgroup/cpu/syz%llu",
           procid);
  char cgroupdir_net[64];
  snprintf(cgroupdir_net, sizeof(cgroupdir_net), "/syzcgroup/net/syz%llu",
           procid);
  if (mkdir(cgroupdir, 0777)) {
  }
  if (mkdir(cgroupdir_cpu, 0777)) {
  }
  if (mkdir(cgroupdir_net, 0777)) {
  }
  int pid = getpid();
  char procs_file[128];
  snprintf(procs_file, sizeof(procs_file), "%s/cgroup.procs", cgroupdir);
  if (!write_file(procs_file, "%d", pid)) {
  }
  snprintf(procs_file, sizeof(procs_file), "%s/cgroup.procs", cgroupdir_cpu);
  if (!write_file(procs_file, "%d", pid)) {
  }
  snprintf(procs_file, sizeof(procs_file), "%s/cgroup.procs", cgroupdir_net);
  if (!write_file(procs_file, "%d", pid)) {
  }
  int iter;
  for (iter = 0;; iter++) {
    char cwdbuf[32];
    sprintf(cwdbuf, "./%d", iter);
    if (mkdir(cwdbuf, 0777))
      fail("failed to mkdir");
    int pid = fork();
    if (pid < 0)
      fail("clone failed");
    if (pid == 0) {
      prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
      setpgrp();
      if (chdir(cwdbuf))
        fail("failed to chdir");
      if (symlink(cgroupdir, "./cgroup")) {
      }
      if (symlink(cgroupdir_cpu, "./cgroup.cpu")) {
      }
      if (symlink(cgroupdir_net, "./cgroup.net")) {
      }
      flush_tun();
      execute_one();
      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 < 3 * 1000)
        continue;
      kill(-pid, SIGKILL);
      kill(pid, SIGKILL);
      while (waitpid(-1, &status, __WALL) != pid) {
      }
      break;
    }
    remove_dir(cwdbuf);
    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;
      }
    }
  }
}

uint64_t r[1] = {0xffffffffffffffff};
unsigned long long procid;
void execute_call(int call)
{
  long res;
  switch (call) {
  case 0:
    syscall(__NR_socket, 0xa, 1, 0);
    break;
  case 1:
    res = syscall(__NR_socket, 2, 0x4000000000000001, 0);
    if (res != -1)
      r[0] = res;
    break;
  case 2:
    *(uint16_t*)0x20000300 = 2;
    *(uint16_t*)0x20000302 = htobe16(0x4e23);
    *(uint32_t*)0x20000304 = htobe32(0xe0000001);
    *(uint8_t*)0x20000308 = 0;
    *(uint8_t*)0x20000309 = 0;
    *(uint8_t*)0x2000030a = 0;
    *(uint8_t*)0x2000030b = 0;
    *(uint8_t*)0x2000030c = 0;
    *(uint8_t*)0x2000030d = 0;
    *(uint8_t*)0x2000030e = 0;
    *(uint8_t*)0x2000030f = 0;
    syscall(__NR_bind, r[0], 0x20000300, 0x10);
    break;
  case 3:
    *(uint16_t*)0x20b86000 = 1;
    *(uint64_t*)0x20b86008 = 0x20f40ff8;
    *(uint16_t*)0x20f40ff8 = 6;
    *(uint8_t*)0x20f40ffa = 0;
    *(uint8_t*)0x20f40ffb = 0;
    *(uint32_t*)0x20f40ffc = 0xe8;
    syscall(__NR_setsockopt, r[0], 1, 0x1a, 0x20b86000, 0x10);
    break;
  case 4:
    *(uint16_t*)0x20e68000 = 2;
    *(uint16_t*)0x20e68002 = htobe16(0x4e23);
    *(uint32_t*)0x20e68004 = htobe32(0x7f000001);
    *(uint8_t*)0x20e68008 = 0;
    *(uint8_t*)0x20e68009 = 0;
    *(uint8_t*)0x20e6800a = 0;
    *(uint8_t*)0x20e6800b = 0;
    *(uint8_t*)0x20e6800c = 0;
    *(uint8_t*)0x20e6800d = 0;
    *(uint8_t*)0x20e6800e = 0;
    *(uint8_t*)0x20e6800f = 0;
    syscall(__NR_sendto, r[0], 0x20a88f88, 0x29f, 0x200007fd, 0x20e68000, 0x10);
    break;
  case 5:
    *(uint64_t*)0x20003ec0 = 0;
    *(uint32_t*)0x20003ec8 = 0;
    *(uint64_t*)0x20003ed0 = 0x20000980;
    *(uint64_t*)0x20000980 = 0x20002640;
    memcpy((void*)0x20002640,
           "\x5b\x53\x31\xd2\x5a\x71\xc6\xa6\x4f\x00\xd9\x07\x20\xf7\x85\xf8"
           "\x8f\x9e\x63\xf9\x0f\x76\xc4\x8f\xee\xe3\x14\x08\x3a\x18\x1e\xef"
           "\xab\x2a\xf8\xa6\x56\x43\xeb\xc8\xc2\xb9\x07\xfd\xeb\xdd\x7b\x6a"
           "\xab\xd0\x4e\xbe\x5b\x31\x33\xae\x10\xd2\x5c\x89\x92\xf9\x69\xf3"
           "\x46\x2f\x98\x56\x49\xa0\xd1\xae\xb7\xd5\x35\x53\x5f\xe9\xce\x30"
           "\xe2\x1d\xc1\x48\x11\xcd\xff\x61\x45\x6d\x71\x41\xcc\x19\xa8\xc8"
           "\x6d\x8c\x80\xcc\xc6\x63\x9c\xbb\x39\x6c\x53\x07\x93\x3f\x3d\x1c"
           "\x5a\x34\x6d\x2d\x3a\x47\x31\x19\x74\xa4\x97\x0a\xba\xcc\xab\x9b"
           "\x06\xaf\xbd\xf0\x03\xeb\x24\xb1\x6c\x82\xaf\x83\x15\x5e\x9b\x55"
           "\x33\xdb\x3e\xeb\x4e\x9c\x07\x22\x10\x5f\xdc\x75\x85\xc7\x7f\x52"
           "\x38\xae\x3d\x12\xf0\x8c\x8a\xb6\xdc\xf0\xed\xb2\x49\x0a\x54\xac"
           "\x46\x93\x22\x50\xeb\x85\x3d\x86\xd1\x0c\xff\x49\xf4\x07\x97\x06"
           "\x2f\xee\x0a\xff\xd7\x47\x73\xc6\x34",
           201);
    *(uint64_t*)0x20000988 = 0xc9;
    *(uint64_t*)0x20003ed8 = 1;
    *(uint64_t*)0x20003ee0 = 0x20003640;
    *(uint64_t*)0x20003ee8 = 0;
    *(uint32_t*)0x20003ef0 = 0;
    *(uint32_t*)0x20003ef8 = 0;
    syscall(__NR_sendmmsg, r[0], 0x20003ec0, 1, 0);
    break;
  case 6:
    *(uint16_t*)0x20000000 = 2;
    *(uint16_t*)0x20000002 = htobe16(0);
    *(uint32_t*)0x20000004 = htobe32(0x7f000001);
    *(uint8_t*)0x20000008 = 0;
    *(uint8_t*)0x20000009 = 0;
    *(uint8_t*)0x2000000a = 0;
    *(uint8_t*)0x2000000b = 0;
    *(uint8_t*)0x2000000c = 0;
    *(uint8_t*)0x2000000d = 0;
    *(uint8_t*)0x2000000e = 0;
    *(uint8_t*)0x2000000f = 0;
    *(uint16_t*)0x20000080 = 0;
    *(uint16_t*)0x20000082 = 0x40;
    *(uint32_t*)0x20000084 = 0;
    memcpy((void*)0x20000088,
           "\xbb\x7d\x97\x9a\x5e\xe0\x32\x05\x6d\xff\x2f\xc6\x39\xba\x63\x68"
           "\xd0\xd7\x1d\x89\x8a\x4e\x12\x4c\xf2\x1c\xd3\x0c\xb7\x09\x65\xe6"
           "\x51\x7b\x9c\xd9\x0b\xda\x98\x21\x88\x6e\x8c\xd3\x63\x7d\xef\x26"
           "\xf9\x25\xad\x25\xed\xc2\xa4\x8d\x53\x20\x74\x8f\x09\x57\xc3\x24"
           "\xfe\x23\xba\xa6\x08\x57\x47\x57\x67\x70\xb4\xaa\xa4\xb7\xba\xb6",
           80);
    syscall(__NR_setsockopt, r[0], 6, 0xe, 0x20000000, 0xd8);
    break;
  case 7:
    *(uint64_t*)0x20004b00 = 0x20002500;
    *(uint32_t*)0x20004b08 = 0x80;
    *(uint64_t*)0x20004b10 = 0x20004340;
    *(uint64_t*)0x20004340 = 0x200041c0;
    *(uint64_t*)0x20004348 = 0xd7;
    *(uint64_t*)0x20004b18 = 1;
    *(uint64_t*)0x20004b20 = 0x20000180;
    *(uint64_t*)0x20004b28 = 0xba;
    *(uint32_t*)0x20004b30 = 0;
    *(uint32_t*)0x20004b38 = 0;
    *(uint64_t*)0x20004b40 = 0x20004600;
    *(uint32_t*)0x20004b48 = 0x80;
    *(uint64_t*)0x20004b50 = 0x20004a40;
    *(uint64_t*)0x20004b58 = 0;
    *(uint64_t*)0x20004b60 = 0x20004ac0;
    *(uint64_t*)0x20004b68 = 0;
    *(uint32_t*)0x20004b70 = 0;
    *(uint32_t*)0x20004b78 = 0;
    *(uint64_t*)0x20000140 = 0;
    *(uint64_t*)0x20000148 = 0;
    syscall(__NR_recvmmsg, r[0], 0x20004b00, 2, 0, 0x20000140);
    break;
  case 8:
    memcpy((void*)0x20000000, "\xcd\x39\x0b\x08\x1b\xf2", 6);
    *(uint8_t*)0x20000006 = -1;
    *(uint8_t*)0x20000007 = -1;
    *(uint8_t*)0x20000008 = -1;
    *(uint8_t*)0x20000009 = -1;
    *(uint8_t*)0x2000000a = -1;
    *(uint8_t*)0x2000000b = -1;
    *(uint16_t*)0x2000000c = htobe16(0x86dd);
    STORE_BY_BITMASK(uint8_t, 0x2000000e, 0, 0, 4);
    STORE_BY_BITMASK(uint8_t, 0x2000000e, 6, 4, 4);
    memcpy((void*)0x2000000f, "\x02\x29\x0f", 3);
    *(uint16_t*)0x20000012 = htobe16(0x30);
    *(uint8_t*)0x20000014 = 0x3a;
    *(uint8_t*)0x20000015 = 0;
    *(uint8_t*)0x20000016 = 0;
    *(uint8_t*)0x20000017 = 0;
    *(uint8_t*)0x20000018 = 0;
    *(uint8_t*)0x20000019 = 0;
    *(uint8_t*)0x2000001a = 0;
    *(uint8_t*)0x2000001b = 0;
    *(uint8_t*)0x2000001c = 0;
    *(uint8_t*)0x2000001d = 0;
    *(uint8_t*)0x2000001e = 0;
    *(uint8_t*)0x2000001f = 0;
    *(uint8_t*)0x20000020 = -1;
    *(uint8_t*)0x20000021 = -1;
    *(uint32_t*)0x20000022 = htobe32(0);
    *(uint8_t*)0x20000026 = -1;
    *(uint8_t*)0x20000027 = 2;
    *(uint8_t*)0x20000028 = 0;
    *(uint8_t*)0x20000029 = 0;
    *(uint8_t*)0x2000002a = 0;
    *(uint8_t*)0x2000002b = 0;
    *(uint8_t*)0x2000002c = 0;
    *(uint8_t*)0x2000002d = 0;
    *(uint8_t*)0x2000002e = 0;
    *(uint8_t*)0x2000002f = 0;
    *(uint8_t*)0x20000030 = 0;
    *(uint8_t*)0x20000031 = 0;
    *(uint8_t*)0x20000032 = 0;
    *(uint8_t*)0x20000033 = 0;
    *(uint8_t*)0x20000034 = 0;
    *(uint8_t*)0x20000035 = 1;
    *(uint8_t*)0x20000036 = 2;
    *(uint8_t*)0x20000037 = 0;
    *(uint16_t*)0x20000038 = 0;
    *(uint32_t*)0x2000003a = htobe32(0);
    STORE_BY_BITMASK(uint8_t, 0x2000003e, 0, 0, 4);
    STORE_BY_BITMASK(uint8_t, 0x2000003e, 6, 4, 4);
    memcpy((void*)0x2000003f, "\x94\x33\xdf", 3);
    *(uint16_t*)0x20000042 = htobe16(0);
    *(uint8_t*)0x20000044 = 4;
    *(uint8_t*)0x20000045 = 0;
    *(uint64_t*)0x20000046 = htobe64(4);
    *(uint64_t*)0x2000004e = htobe64(1);
    *(uint8_t*)0x20000056 = 0xfe;
    *(uint8_t*)0x20000057 = 0x80;
    *(uint8_t*)0x20000058 = 0;
    *(uint8_t*)0x20000059 = 0;
    *(uint8_t*)0x2000005a = 0;
    *(uint8_t*)0x2000005b = 0;
    *(uint8_t*)0x2000005c = 0;
    *(uint8_t*)0x2000005d = 0;
    *(uint8_t*)0x2000005e = 0xb;
    *(uint8_t*)0x2000005f = 0;
    *(uint8_t*)0x20000060 = 0;
    *(uint8_t*)0x20000061 = 0;
    *(uint8_t*)0x20000062 = 0;
    *(uint8_t*)0x20000063 = 0;
    *(uint8_t*)0x20000064 = 0;
    *(uint8_t*)0x20000065 = 0;
    struct csum_inet csum_1;
    csum_inet_init(&csum_1);
    csum_inet_update(&csum_1, (const uint8_t*)0x20000016, 16);
    csum_inet_update(&csum_1, (const uint8_t*)0x20000026, 16);
    uint32_t csum_1_chunk_2 = 0x30000000;
    csum_inet_update(&csum_1, (const uint8_t*)&csum_1_chunk_2, 4);
    uint32_t csum_1_chunk_3 = 0x3a000000;
    csum_inet_update(&csum_1, (const uint8_t*)&csum_1_chunk_3, 4);
    csum_inet_update(&csum_1, (const uint8_t*)0x20000036, 48);
    *(uint16_t*)0x20000038 = csum_inet_digest(&csum_1);
    syz_emit_ethernet(0x66, 0x20000000, 0);
    break;
  }
}

void execute_one()
{
  execute(9);
  collide = 1;
  execute(9);
}

int main()
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  char* cwd = get_current_dir_name();
  for (procid = 0; procid < 8; procid++) {
    if (fork() == 0) {
      for (;;) {
        if (chdir(cwd))
          fail("failed to chdir");
        use_temporary_dir();
        int pid = do_sandbox_none();
        int status = 0;
        while (waitpid(pid, &status, __WALL) != pid) {
        }
      }
    }
  }
  sleep(1000000);
  return 0;
}