// https://syzkaller.appspot.com/bug?id=a74f2e95ca33a81cdf5783a3df43762ced5c83e9
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <arpa/inet.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <netinet/in.h>
#include <pthread.h>
#include <sched.h>
#include <setjmp.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

#include <linux/capability.h>
#include <linux/futex.h>
#include <linux/genetlink.h>
#include <linux/if_addr.h>
#include <linux/if_ether.h>
#include <linux/if_link.h>
#include <linux/if_tun.h>
#include <linux/in6.h>
#include <linux/ip.h>
#include <linux/neighbour.h>
#include <linux/net.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/tcp.h>
#include <linux/veth.h>

#ifndef __NR_bpf
#define __NR_bpf 280
#endif
#ifndef __NR_mmap
#define __NR_mmap 222
#endif
#ifndef __NR_mprotect
#define __NR_mprotect 226
#endif

static __thread int clone_ongoing;
static __thread int skip_segv;
static __thread jmp_buf segv_env;

static void segv_handler(int sig, siginfo_t* info, void* ctx)
{
  if (__atomic_load_n(&clone_ongoing, __ATOMIC_RELAXED) != 0) {
    exit(sig);
  }
  uintptr_t addr = (uintptr_t)info->si_addr;
  const uintptr_t prog_start = 1 << 20;
  const uintptr_t prog_end = 100 << 20;
  int skip = __atomic_load_n(&skip_segv, __ATOMIC_RELAXED) != 0;
  int valid = addr < prog_start || addr > prog_end;
  if (skip && valid) {
    _longjmp(segv_env, 1);
  }
  exit(sig);
}

static void install_segv_handler(void)
{
  struct sigaction sa;
  memset(&sa, 0, sizeof(sa));
  sa.sa_handler = SIG_IGN;
  syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8);
  syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8);
  memset(&sa, 0, sizeof(sa));
  sa.sa_sigaction = segv_handler;
  sa.sa_flags = SA_NODEFER | SA_SIGINFO;
  sigaction(SIGSEGV, &sa, NULL);
  sigaction(SIGBUS, &sa, NULL);
}

#define NONFAILING(...)                                                        \
  ({                                                                           \
    int ok = 1;                                                                \
    __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
    if (_setjmp(segv_env) == 0) {                                              \
      __VA_ARGS__;                                                             \
    } else                                                                     \
      ok = 0;                                                                  \
    __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
    ok;                                                                        \
  })

static void sleep_ms(uint64_t ms)
{
  usleep(ms * 1000);
}

static uint64_t current_time_ms(void)
{
  struct timespec ts;
  if (clock_gettime(CLOCK_MONOTONIC, &ts))
    exit(1);
  return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;
}

static void thread_start(void* (*fn)(void*), void* arg)
{
  pthread_t th;
  pthread_attr_t attr;
  pthread_attr_init(&attr);
  pthread_attr_setstacksize(&attr, 128 << 10);
  int i = 0;
  for (; i < 100; i++) {
    if (pthread_create(&th, &attr, fn, arg) == 0) {
      pthread_attr_destroy(&attr);
      return;
    }
    if (errno == EAGAIN) {
      usleep(50);
      continue;
    }
    break;
  }
  exit(1);
}

#define BITMASK(bf_off, bf_len) (((1ull << (bf_len)) - 1) << (bf_off))
#define STORE_BY_BITMASK(type, htobe, addr, val, bf_off, bf_len)               \
  *(type*)(addr) =                                                             \
      htobe((htobe(*(type*)(addr)) & ~BITMASK((bf_off), (bf_len))) |           \
            (((type)(val) << (bf_off)) & BITMASK((bf_off), (bf_len))))

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 = 0;
  for (; i < length - 1; i += 2)
    csum->acc += *(uint16_t*)&data[i];
  if (length & 1)
    csum->acc += le16toh((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;
}

typedef struct {
  int state;
} event_t;

static void event_init(event_t* ev)
{
  ev->state = 0;
}

static void event_reset(event_t* ev)
{
  ev->state = 0;
}

static void event_set(event_t* ev)
{
  if (ev->state)
    exit(1);
  __atomic_store_n(&ev->state, 1, __ATOMIC_RELEASE);
  syscall(SYS_futex, &ev->state, FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1000000);
}

static void event_wait(event_t* ev)
{
  while (!__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE))
    syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, 0);
}

static int event_isset(event_t* ev)
{
  return __atomic_load_n(&ev->state, __ATOMIC_ACQUIRE);
}

static int event_timedwait(event_t* ev, uint64_t timeout)
{
  uint64_t start = current_time_ms();
  uint64_t now = start;
  for (;;) {
    uint64_t remain = timeout - (now - start);
    struct timespec ts;
    ts.tv_sec = remain / 1000;
    ts.tv_nsec = (remain % 1000) * 1000 * 1000;
    syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, &ts);
    if (__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE))
      return 1;
    now = current_time_ms();
    if (now - start > timeout)
      return 0;
  }
}

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;
}

struct nlmsg {
  char* pos;
  int nesting;
  struct nlattr* nested[8];
  char buf[4096];
};

static void netlink_init(struct nlmsg* nlmsg, int typ, int flags,
                         const void* data, int size)
{
  memset(nlmsg, 0, sizeof(*nlmsg));
  struct nlmsghdr* hdr = (struct nlmsghdr*)nlmsg->buf;
  hdr->nlmsg_type = typ;
  hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags;
  memcpy(hdr + 1, data, size);
  nlmsg->pos = (char*)(hdr + 1) + NLMSG_ALIGN(size);
}

static void netlink_attr(struct nlmsg* nlmsg, int typ, const void* data,
                         int size)
{
  struct nlattr* attr = (struct nlattr*)nlmsg->pos;
  attr->nla_len = sizeof(*attr) + size;
  attr->nla_type = typ;
  if (size > 0)
    memcpy(attr + 1, data, size);
  nlmsg->pos += NLMSG_ALIGN(attr->nla_len);
}

static int netlink_send_ext(struct nlmsg* nlmsg, int sock, uint16_t reply_type,
                            int* reply_len, bool dofail)
{
  if (nlmsg->pos > nlmsg->buf + sizeof(nlmsg->buf) || nlmsg->nesting)
    exit(1);
  struct nlmsghdr* hdr = (struct nlmsghdr*)nlmsg->buf;
  hdr->nlmsg_len = nlmsg->pos - nlmsg->buf;
  struct sockaddr_nl addr;
  memset(&addr, 0, sizeof(addr));
  addr.nl_family = AF_NETLINK;
  ssize_t n = sendto(sock, nlmsg->buf, hdr->nlmsg_len, 0,
                     (struct sockaddr*)&addr, sizeof(addr));
  if (n != (ssize_t)hdr->nlmsg_len) {
    if (dofail)
      exit(1);
    return -1;
  }
  n = recv(sock, nlmsg->buf, sizeof(nlmsg->buf), 0);
  if (reply_len)
    *reply_len = 0;
  if (n < 0) {
    if (dofail)
      exit(1);
    return -1;
  }
  if (n < (ssize_t)sizeof(struct nlmsghdr)) {
    errno = EINVAL;
    if (dofail)
      exit(1);
    return -1;
  }
  if (hdr->nlmsg_type == NLMSG_DONE)
    return 0;
  if (reply_len && hdr->nlmsg_type == reply_type) {
    *reply_len = n;
    return 0;
  }
  if (n < (ssize_t)(sizeof(struct nlmsghdr) + sizeof(struct nlmsgerr))) {
    errno = EINVAL;
    if (dofail)
      exit(1);
    return -1;
  }
  if (hdr->nlmsg_type != NLMSG_ERROR) {
    errno = EINVAL;
    if (dofail)
      exit(1);
    return -1;
  }
  errno = -((struct nlmsgerr*)(hdr + 1))->error;
  return -errno;
}

static int netlink_send(struct nlmsg* nlmsg, int sock)
{
  return netlink_send_ext(nlmsg, sock, 0, NULL, true);
}

static int netlink_query_family_id(struct nlmsg* nlmsg, int sock,
                                   const char* family_name, bool dofail)
{
  struct genlmsghdr genlhdr;
  memset(&genlhdr, 0, sizeof(genlhdr));
  genlhdr.cmd = CTRL_CMD_GETFAMILY;
  netlink_init(nlmsg, GENL_ID_CTRL, 0, &genlhdr, sizeof(genlhdr));
  netlink_attr(nlmsg, CTRL_ATTR_FAMILY_NAME, family_name,
               strnlen(family_name, GENL_NAMSIZ - 1) + 1);
  int n = 0;
  int err = netlink_send_ext(nlmsg, sock, GENL_ID_CTRL, &n, dofail);
  if (err < 0) {
    return -1;
  }
  uint16_t id = 0;
  struct nlattr* attr = (struct nlattr*)(nlmsg->buf + NLMSG_HDRLEN +
                                         NLMSG_ALIGN(sizeof(genlhdr)));
  for (; (char*)attr < nlmsg->buf + n;
       attr = (struct nlattr*)((char*)attr + NLMSG_ALIGN(attr->nla_len))) {
    if (attr->nla_type == CTRL_ATTR_FAMILY_ID) {
      id = *(uint16_t*)(attr + 1);
      break;
    }
  }
  if (!id) {
    errno = EINVAL;
    return -1;
  }
  recv(sock, nlmsg->buf, sizeof(nlmsg->buf), 0);
  return id;
}

static void netlink_device_change(struct nlmsg* nlmsg, int sock,
                                  const char* name, bool up, const char* master,
                                  const void* mac, int macsize,
                                  const char* new_name)
{
  struct ifinfomsg hdr;
  memset(&hdr, 0, sizeof(hdr));
  if (up)
    hdr.ifi_flags = hdr.ifi_change = IFF_UP;
  hdr.ifi_index = if_nametoindex(name);
  netlink_init(nlmsg, RTM_NEWLINK, 0, &hdr, sizeof(hdr));
  if (new_name)
    netlink_attr(nlmsg, IFLA_IFNAME, new_name, strlen(new_name));
  if (master) {
    int ifindex = if_nametoindex(master);
    netlink_attr(nlmsg, IFLA_MASTER, &ifindex, sizeof(ifindex));
  }
  if (macsize)
    netlink_attr(nlmsg, IFLA_ADDRESS, mac, macsize);
  int err = netlink_send(nlmsg, sock);
  if (err < 0) {
  }
}

static int netlink_add_addr(struct nlmsg* nlmsg, int sock, const char* dev,
                            const void* addr, int addrsize)
{
  struct ifaddrmsg hdr;
  memset(&hdr, 0, sizeof(hdr));
  hdr.ifa_family = addrsize == 4 ? AF_INET : AF_INET6;
  hdr.ifa_prefixlen = addrsize == 4 ? 24 : 120;
  hdr.ifa_scope = RT_SCOPE_UNIVERSE;
  hdr.ifa_index = if_nametoindex(dev);
  netlink_init(nlmsg, RTM_NEWADDR, NLM_F_CREATE | NLM_F_REPLACE, &hdr,
               sizeof(hdr));
  netlink_attr(nlmsg, IFA_LOCAL, addr, addrsize);
  netlink_attr(nlmsg, IFA_ADDRESS, addr, addrsize);
  return netlink_send(nlmsg, sock);
}

static void netlink_add_addr4(struct nlmsg* nlmsg, int sock, const char* dev,
                              const char* addr)
{
  struct in_addr in_addr;
  inet_pton(AF_INET, addr, &in_addr);
  int err = netlink_add_addr(nlmsg, sock, dev, &in_addr, sizeof(in_addr));
  if (err < 0) {
  }
}

static void netlink_add_addr6(struct nlmsg* nlmsg, int sock, const char* dev,
                              const char* addr)
{
  struct in6_addr in6_addr;
  inet_pton(AF_INET6, addr, &in6_addr);
  int err = netlink_add_addr(nlmsg, sock, dev, &in6_addr, sizeof(in6_addr));
  if (err < 0) {
  }
}

static void netlink_add_neigh(struct nlmsg* nlmsg, int sock, const char* name,
                              const void* addr, int addrsize, const void* mac,
                              int macsize)
{
  struct ndmsg hdr;
  memset(&hdr, 0, sizeof(hdr));
  hdr.ndm_family = addrsize == 4 ? AF_INET : AF_INET6;
  hdr.ndm_ifindex = if_nametoindex(name);
  hdr.ndm_state = NUD_PERMANENT;
  netlink_init(nlmsg, RTM_NEWNEIGH, NLM_F_EXCL | NLM_F_CREATE, &hdr,
               sizeof(hdr));
  netlink_attr(nlmsg, NDA_DST, addr, addrsize);
  netlink_attr(nlmsg, NDA_LLADDR, mac, macsize);
  int err = netlink_send(nlmsg, sock);
  if (err < 0) {
  }
}

static struct nlmsg nlmsg;

static int tunfd = -1;

#define TUN_IFACE "syz_tun"
#define LOCAL_MAC 0xaaaaaaaaaaaa
#define REMOTE_MAC 0xaaaaaaaaaabb
#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

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 = 200;
  if (dup2(tunfd, kTunFd) < 0)
    exit(1);
  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;
  if (ioctl(tunfd, TUNSETIFF, (void*)&ifr) < 0) {
    exit(1);
  }
  char sysctl[64];
  sprintf(sysctl, "/proc/sys/net/ipv6/conf/%s/accept_dad", TUN_IFACE);
  write_file(sysctl, "0");
  sprintf(sysctl, "/proc/sys/net/ipv6/conf/%s/router_solicitations", TUN_IFACE);
  write_file(sysctl, "0");
  int sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
  if (sock == -1)
    exit(1);
  netlink_add_addr4(&nlmsg, sock, TUN_IFACE, LOCAL_IPV4);
  netlink_add_addr6(&nlmsg, sock, TUN_IFACE, LOCAL_IPV6);
  uint64_t macaddr = REMOTE_MAC;
  struct in_addr in_addr;
  inet_pton(AF_INET, REMOTE_IPV4, &in_addr);
  netlink_add_neigh(&nlmsg, sock, TUN_IFACE, &in_addr, sizeof(in_addr),
                    &macaddr, ETH_ALEN);
  struct in6_addr in6_addr;
  inet_pton(AF_INET6, REMOTE_IPV6, &in6_addr);
  netlink_add_neigh(&nlmsg, sock, TUN_IFACE, &in6_addr, sizeof(in6_addr),
                    &macaddr, ETH_ALEN);
  macaddr = LOCAL_MAC;
  netlink_device_change(&nlmsg, sock, TUN_IFACE, true, 0, &macaddr, ETH_ALEN,
                        NULL);
  close(sock);
}

static long syz_emit_ethernet(volatile long a0, volatile long a1,
                              volatile long a2)
{
  if (tunfd < 0)
    return (uintptr_t)-1;
  uint32_t length = a0;
  char* data = (char*)a1;
  return write(tunfd, data, length);
}

static void setup_gadgetfs();
static void setup_binderfs();
static void setup_fusectl();
static void sandbox_common_mount_tmpfs(void)
{
  write_file("/proc/sys/fs/mount-max", "100000");
  if (mkdir("./syz-tmp", 0777))
    exit(1);
  if (mount("", "./syz-tmp", "tmpfs", 0, NULL))
    exit(1);
  if (mkdir("./syz-tmp/newroot", 0777))
    exit(1);
  if (mkdir("./syz-tmp/newroot/dev", 0700))
    exit(1);
  unsigned bind_mount_flags = MS_BIND | MS_REC | MS_PRIVATE;
  if (mount("/dev", "./syz-tmp/newroot/dev", NULL, bind_mount_flags, NULL))
    exit(1);
  if (mkdir("./syz-tmp/newroot/proc", 0700))
    exit(1);
  if (mount("syz-proc", "./syz-tmp/newroot/proc", "proc", 0, NULL))
    exit(1);
  if (mkdir("./syz-tmp/newroot/selinux", 0700))
    exit(1);
  const char* selinux_path = "./syz-tmp/newroot/selinux";
  if (mount("/selinux", selinux_path, NULL, bind_mount_flags, NULL)) {
    if (errno != ENOENT)
      exit(1);
    if (mount("/sys/fs/selinux", selinux_path, NULL, bind_mount_flags, NULL) &&
        errno != ENOENT)
      exit(1);
  }
  if (mkdir("./syz-tmp/newroot/sys", 0700))
    exit(1);
  if (mount("/sys", "./syz-tmp/newroot/sys", 0, bind_mount_flags, NULL))
    exit(1);
  if (mount("/sys/kernel/debug", "./syz-tmp/newroot/sys/kernel/debug", NULL,
            bind_mount_flags, NULL) &&
      errno != ENOENT)
    exit(1);
  if (mount("/sys/fs/smackfs", "./syz-tmp/newroot/sys/fs/smackfs", NULL,
            bind_mount_flags, NULL) &&
      errno != ENOENT)
    exit(1);
  if (mount("/proc/sys/fs/binfmt_misc",
            "./syz-tmp/newroot/proc/sys/fs/binfmt_misc", NULL, bind_mount_flags,
            NULL) &&
      errno != ENOENT)
    exit(1);
  if (mkdir("./syz-tmp/newroot/syz-inputs", 0700))
    exit(1);
  if (mount("/syz-inputs", "./syz-tmp/newroot/syz-inputs", NULL,
            bind_mount_flags | MS_RDONLY, NULL) &&
      errno != ENOENT)
    exit(1);
  if (mkdir("./syz-tmp/pivot", 0777))
    exit(1);
  if (syscall(SYS_pivot_root, "./syz-tmp", "./syz-tmp/pivot")) {
    if (chdir("./syz-tmp"))
      exit(1);
  } else {
    if (chdir("/"))
      exit(1);
    if (umount2("./pivot", MNT_DETACH))
      exit(1);
  }
  if (chroot("./newroot"))
    exit(1);
  if (chdir("/"))
    exit(1);
  setup_gadgetfs();
  setup_binderfs();
  setup_fusectl();
}

static void setup_gadgetfs()
{
  if (mkdir("/dev/gadgetfs", 0777)) {
  }
  if (mount("gadgetfs", "/dev/gadgetfs", "gadgetfs", 0, NULL)) {
  }
}

static void setup_fusectl()
{
  if (mount(0, "/sys/fs/fuse/connections", "fusectl", 0, 0)) {
  }
}

static void setup_binderfs()
{
  if (mkdir("/dev/binderfs", 0777)) {
  }
  if (mount("binder", "/dev/binderfs", "binder", 0, NULL)) {
  }
  if (symlink("/dev/binderfs", "./binderfs")) {
  }
}

static void loop();

static void sandbox_common()
{
  prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
  if (getppid() == 1)
    exit(1);
  struct rlimit rlim;
  rlim.rlim_cur = rlim.rlim_max = (200 << 20);
  setrlimit(RLIMIT_AS, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 32 << 20;
  setrlimit(RLIMIT_MEMLOCK, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 136 << 20;
  setrlimit(RLIMIT_FSIZE, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 1 << 20;
  setrlimit(RLIMIT_STACK, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 128 << 20;
  setrlimit(RLIMIT_CORE, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 256;
  setrlimit(RLIMIT_NOFILE, &rlim);
  if (unshare(CLONE_NEWNS)) {
  }
  if (mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, NULL)) {
  }
  if (unshare(CLONE_NEWIPC)) {
  }
  if (unshare(0x02000000)) {
  }
  if (unshare(CLONE_NEWUTS)) {
  }
  if (unshare(CLONE_SYSVSEM)) {
  }
  typedef struct {
    const char* name;
    const char* value;
  } sysctl_t;
  static const sysctl_t sysctls[] = {
      {"/proc/sys/kernel/shmmax", "16777216"},
      {"/proc/sys/kernel/shmall", "536870912"},
      {"/proc/sys/kernel/shmmni", "1024"},
      {"/proc/sys/kernel/msgmax", "8192"},
      {"/proc/sys/kernel/msgmni", "1024"},
      {"/proc/sys/kernel/msgmnb", "1024"},
      {"/proc/sys/kernel/sem", "1024 1048576 500 1024"},
  };
  unsigned i;
  for (i = 0; i < sizeof(sysctls) / sizeof(sysctls[0]); i++)
    write_file(sysctls[i].name, sysctls[i].value);
}

static int wait_for_loop(int pid)
{
  if (pid < 0)
    exit(1);
  int status = 0;
  while (waitpid(-1, &status, __WALL) != pid) {
  }
  return WEXITSTATUS(status);
}

static void drop_caps(void)
{
  struct __user_cap_header_struct cap_hdr = {};
  struct __user_cap_data_struct cap_data[2] = {};
  cap_hdr.version = _LINUX_CAPABILITY_VERSION_3;
  cap_hdr.pid = getpid();
  if (syscall(SYS_capget, &cap_hdr, &cap_data))
    exit(1);
  const int drop = (1 << CAP_SYS_PTRACE) | (1 << CAP_SYS_NICE);
  cap_data[0].effective &= ~drop;
  cap_data[0].permitted &= ~drop;
  cap_data[0].inheritable &= ~drop;
  if (syscall(SYS_capset, &cap_hdr, &cap_data))
    exit(1);
}

static int do_sandbox_none(void)
{
  if (unshare(CLONE_NEWPID)) {
  }
  int pid = fork();
  if (pid != 0)
    return wait_for_loop(pid);
  sandbox_common();
  drop_caps();
  if (unshare(CLONE_NEWNET)) {
  }
  write_file("/proc/sys/net/ipv4/ping_group_range", "0 65535");
  initialize_tun();
  sandbox_common_mount_tmpfs();
  loop();
  exit(1);
}

struct thread_t {
  int created, call;
  event_t ready, done;
};

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 (;;) {
    event_wait(&th->ready);
    event_reset(&th->ready);
    execute_call(th->call);
    __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED);
    event_set(&th->done);
  }
  return 0;
}

static void loop(void)
{
  if (write(1, "executing program\n", sizeof("executing program\n") - 1)) {
  }
  int i, call, thread;
  for (call = 0; call < 5; call++) {
    for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0]));
         thread++) {
      struct thread_t* th = &threads[thread];
      if (!th->created) {
        th->created = 1;
        event_init(&th->ready);
        event_init(&th->done);
        event_set(&th->done);
        thread_start(thr, th);
      }
      if (!event_isset(&th->done))
        continue;
      event_reset(&th->done);
      th->call = call;
      __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED);
      event_set(&th->ready);
      event_timedwait(&th->done, 50);
      break;
    }
  }
  for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++)
    sleep_ms(1);
}

uint64_t r[1] = {0xffffffffffffffff};

void execute_call(int call)
{
  intptr_t res = 0;
  switch (call) {
  case 0:
    //  syz_emit_ethernet arguments: [
    //    len: len = 0x4a (8 bytes)
    //    packet: ptr[in, eth_packet] {
    //      eth_packet {
    //        dst_mac: union mac_addr {
    //          link_local: mac_addr_link_local {
    //            a0: const = 0x1 (1 bytes)
    //            a1: const = 0x80 (1 bytes)
    //            a2: const = 0xc2 (1 bytes)
    //            a3: const = 0x0 (1 bytes)
    //            a4: const = 0x0 (1 bytes)
    //            a5: mac_addr_link_local_values = 0x1 (1 bytes)
    //          }
    //        }
    //        src_mac: union mac_addr {
    //          dev: mac_addr_t[netdev_addr_id] {
    //            a0: buffer: {aa aa aa aa aa} (length 0x5)
    //            a1: int8 = 0xd (1 bytes)
    //          }
    //        }
    //        vtag: union optional[vlan_tag] {
    //          void: buffer: {} (length 0x0)
    //        }
    //        payload: eth_payload {
    //          eth2: union eth2_packet {
    //            ipv6: eth2_packet_t[ETH_P_IPV6, ipv6_packet] {
    //              etype: const = 0x86dd (2 bytes)
    //              payload: union ipv6_packet {
    //                icmpv6: ipv6_packet_t[const[IPPROTO_ICMPV6, int8],
    //                icmpv6_packet] {
    //                  priority: int8 = 0xa (0 bytes)
    //                  version: const = 0x6 (1 bytes)
    //                  flow_label: buffer: {4f 3f 8a} (length 0x3)
    //                  length: len = 0x14 (2 bytes)
    //                  next_header: const = 0x3a (1 bytes)
    //                  hop_limit: hop_limits = 0x0 (1 bytes)
    //                  src_ip: union ipv6_addr {
    //                    private2: ipv6_addr_private[2] {
    //                      a0: const = 0xfc (1 bytes)
    //                      a1: const = 0x2 (1 bytes)
    //                      a2: buffer: {00 00 00 00 00 00 00 00 00 00 00 00 00}
    //                      (length 0xd) a3: int8 = 0x0 (1 bytes)
    //                    }
    //                  }
    //                  dst_ip: union ipv6_addr {
    //                    private2: ipv6_addr_private[2] {
    //                      a0: const = 0xfc (1 bytes)
    //                      a1: const = 0x2 (1 bytes)
    //                      a2: buffer: {00 00 00 00 00 00 00 00 00 00 00 00 00}
    //                      (length 0xd) a3: int8 = 0x0 (1 bytes)
    //                    }
    //                  }
    //                  payload: ipv6_packet_payload[icmpv6_packet] {
    //                    ext_headers: array[ipv6_ext_header] {
    //                    }
    //                    payload: union icmpv6_packet {
    //                      ndisc_ns: icmpv6_ndisc_neigh_solicit_packet {
    //                        type: const = 0x87 (1 bytes)
    //                        code: const = 0x0 (1 bytes)
    //                        csum: csum = 0x0 (2 bytes)
    //                        target_addr: union ipv6_addr {
    //                          private0: ipv6_addr_private[0] {
    //                            a0: const = 0xfc (1 bytes)
    //                            a1: const = 0x0 (1 bytes)
    //                            a2: buffer: {00 00 00 00 00 00 00 00 00 00 00
    //                            00 00} (length 0xd) a3: int8 = 0x1 (1 bytes)
    //                          }
    //                        }
    //                        options: array[icmpv6_ndisc_option] {
    //                        }
    //                      }
    //                    }
    //                  }
    //                }
    //              }
    //            }
    //          }
    //        }
    //      }
    //    }
    //    frags: nil
    //  ]
    NONFAILING(*(uint8_t*)0x200010c0 = 1);
    NONFAILING(*(uint8_t*)0x200010c1 = 0x80);
    NONFAILING(*(uint8_t*)0x200010c2 = 0xc2);
    NONFAILING(*(uint8_t*)0x200010c3 = 0);
    NONFAILING(*(uint8_t*)0x200010c4 = 0);
    NONFAILING(*(uint8_t*)0x200010c5 = 1);
    NONFAILING(memset((void*)0x200010c6, 170, 5));
    NONFAILING(*(uint8_t*)0x200010cb = 0xd);
    NONFAILING(*(uint16_t*)0x200010cc = htobe16(0x86dd));
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x200010ce, 0xa, 0, 4));
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x200010ce, 6, 4, 4));
    NONFAILING(memcpy((void*)0x200010cf, "\x4f\x3f\x8a", 3));
    NONFAILING(*(uint16_t*)0x200010d2 = htobe16(0x14));
    NONFAILING(*(uint8_t*)0x200010d4 = 0x3a);
    NONFAILING(*(uint8_t*)0x200010d5 = 0);
    NONFAILING(*(uint8_t*)0x200010d6 = 0xfc);
    NONFAILING(*(uint8_t*)0x200010d7 = 2);
    NONFAILING(memset((void*)0x200010d8, 0, 13));
    NONFAILING(*(uint8_t*)0x200010e5 = 0);
    NONFAILING(*(uint8_t*)0x200010e6 = 0xfc);
    NONFAILING(*(uint8_t*)0x200010e7 = 2);
    NONFAILING(memset((void*)0x200010e8, 0, 13));
    NONFAILING(*(uint8_t*)0x200010f5 = 0);
    NONFAILING(*(uint8_t*)0x200010f6 = 0x87);
    NONFAILING(*(uint8_t*)0x200010f7 = 0);
    NONFAILING(*(uint16_t*)0x200010f8 = htobe16(0));
    NONFAILING(*(uint8_t*)0x200010fa = 0xfc);
    NONFAILING(*(uint8_t*)0x200010fb = 0);
    NONFAILING(memset((void*)0x200010fc, 0, 13));
    NONFAILING(*(uint8_t*)0x20001109 = 1);
    struct csum_inet csum_1;
    csum_inet_init(&csum_1);
    NONFAILING(csum_inet_update(&csum_1, (const uint8_t*)0x200010d6, 16));
    NONFAILING(csum_inet_update(&csum_1, (const uint8_t*)0x200010e6, 16));
    uint32_t csum_1_chunk_2 = 0x14000000;
    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);
    NONFAILING(csum_inet_update(&csum_1, (const uint8_t*)0x200010f6, 20));
    NONFAILING(*(uint16_t*)0x200010f8 = csum_inet_digest(&csum_1));
    NONFAILING(
        syz_emit_ethernet(/*len=*/0x4a, /*packet=*/0x200010c0, /*frags=*/0));
    break;
  case 1:
    //  bpf$MAP_CREATE arguments: [
    //    cmd: const = 0x0 (8 bytes)
    //    arg: ptr[in, bpf_map_create_arg] {
    //      union bpf_map_create_arg {
    //        base: bpf_map_create_arg_t[flags[bpf_map_type, int32], int32,
    //        int32, int32, flags[map_flags, int32], const[0, int64]] {
    //          type: bpf_map_type = 0x5 (4 bytes)
    //          ksize: int32 = 0xb (4 bytes)
    //          vsize: int32 = 0xa (4 bytes)
    //          max: int32 = 0x9 (4 bytes)
    //          flags: map_flags = 0x0 (4 bytes)
    //          inner: fd_bpf_map (resource)
    //          node: int32 = 0x0 (4 bytes)
    //          map_name: buffer: {00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    //          00} (length 0x10) map_ifindex: ifindex (resource) btf_fd: fd_btf
    //          (resource) btf_key_type_id: int32 = 0x0 (4 bytes)
    //          btf_value_type_id: int32 = 0x0 (4 bytes)
    //          btf_vmlinux_type_id: int32 = 0x0 (4 bytes)
    //          map_extra: const = 0x0 (8 bytes)
    //          value_type_btf_obj_fd: union
    //          _bpf_map_create_arg_t[flags[bpf_map_type, int32], int32, int32,
    //          int32, flags[map_flags, int32], const[0,
    //          int64]]_value_type_btf_obj_fd_wrapper {
    //            void: buffer: {} (length 0x0)
    //          }
    //          pad1: union _bpf_map_create_arg_t[flags[bpf_map_type, int32],
    //          int32, int32, int32, flags[map_flags, int32], const[0,
    //          int64]]_pad1_wrapper {
    //            value: const = 0x0 (4 bytes)
    //          }
    //          map_token_fd: union _bpf_map_create_arg_t[flags[bpf_map_type,
    //          int32], int32, int32, int32, flags[map_flags, int32], const[0,
    //          int64]]_map_token_fd_wrapper {
    //            void: buffer: {} (length 0x0)
    //          }
    //          pad2: union _bpf_map_create_arg_t[flags[bpf_map_type, int32],
    //          int32, int32, int32, flags[map_flags, int32], const[0,
    //          int64]]_pad2_wrapper {
    //            value: const = 0x0 (4 bytes)
    //          }
    //        }
    //      }
    //    }
    //    size: len = 0x50 (8 bytes)
    //  ]
    //  returns fd_bpf_map
    NONFAILING(*(uint32_t*)0x200000c0 = 5);
    NONFAILING(*(uint32_t*)0x200000c4 = 0xb);
    NONFAILING(*(uint32_t*)0x200000c8 = 0xa);
    NONFAILING(*(uint32_t*)0x200000cc = 9);
    NONFAILING(*(uint32_t*)0x200000d0 = 0);
    NONFAILING(*(uint32_t*)0x200000d4 = 1);
    NONFAILING(*(uint32_t*)0x200000d8 = 0);
    NONFAILING(memset((void*)0x200000dc, 0, 16));
    NONFAILING(*(uint32_t*)0x200000ec = 0);
    NONFAILING(*(uint32_t*)0x200000f0 = -1);
    NONFAILING(*(uint32_t*)0x200000f4 = 0);
    NONFAILING(*(uint32_t*)0x200000f8 = 0);
    NONFAILING(*(uint32_t*)0x200000fc = 0);
    NONFAILING(*(uint64_t*)0x20000100 = 0);
    NONFAILING(*(uint32_t*)0x20000108 = 0);
    NONFAILING(*(uint32_t*)0x2000010c = 0);
    res = syscall(__NR_bpf, /*cmd=*/0ul, /*arg=*/0x200000c0ul, /*size=*/0x50ul);
    if (res != -1)
      r[0] = res;
    break;
  case 2:
    //  bpf$MAP_UPDATE_BATCH arguments: [
    //    cmd: const = 0x1a (8 bytes)
    //    arg: ptr[in, bpf_map_batch_arg] {
    //      bpf_map_batch_arg {
    //        in_batch: nil
    //        out_batch: nil
    //        key: ptr[in, buffer] {
    //          buffer: {} (length 0x0)
    //        }
    //        val: ptr[in, buffer] {
    //          buffer: {} (length 0x0)
    //        }
    //        count: int32 = 0x8000 (4 bytes)
    //        map_fd: fd_bpf_map (resource)
    //        elem_flags: bpf_batch_flags = 0x0 (8 bytes)
    //        flags: const = 0x0 (8 bytes)
    //      }
    //    }
    //    size: len = 0x38 (8 bytes)
    //  ]
    NONFAILING(*(uint64_t*)0x20001600 = 0);
    NONFAILING(*(uint64_t*)0x20001608 = 0);
    NONFAILING(*(uint64_t*)0x20001610 = 0x20000000);
    NONFAILING(*(uint64_t*)0x20001618 = 0x20001680);
    NONFAILING(*(uint32_t*)0x20001620 = 0x8000);
    NONFAILING(*(uint32_t*)0x20001624 = r[0]);
    NONFAILING(*(uint64_t*)0x20001628 = 0);
    NONFAILING(*(uint64_t*)0x20001630 = 0);
    syscall(__NR_bpf, /*cmd=*/0x1aul, /*arg=*/0x20001600ul, /*size=*/0x38ul);
    break;
  case 3:
    //  mprotect arguments: [
    //    addr: VMA[0x4000]
    //    len: len = 0x4000 (8 bytes)
    //    prot: mmap_prot = 0x1 (8 bytes)
    //  ]
    syscall(__NR_mprotect, /*addr=*/0x20000000ul, /*len=*/0x4000ul,
            /*prot=PROT_READ*/ 1ul);
    break;
  case 4:
    //  bpf$MAP_UPDATE_BATCH arguments: [
    //    cmd: const = 0x19 (8 bytes)
    //    arg: ptr[in, bpf_map_batch_arg] {
    //      bpf_map_batch_arg {
    //        in_batch: nil
    //        out_batch: nil
    //        key: nil
    //        val: nil
    //        count: int32 = 0x1 (4 bytes)
    //        map_fd: fd_bpf_map (resource)
    //        elem_flags: bpf_batch_flags = 0x0 (8 bytes)
    //        flags: const = 0x0 (8 bytes)
    //      }
    //    }
    //    size: len = 0x38 (8 bytes)
    //  ]
    NONFAILING(*(uint64_t*)0x20001600 = 0);
    NONFAILING(*(uint64_t*)0x20001608 = 0);
    NONFAILING(*(uint64_t*)0x20001610 = 0);
    NONFAILING(*(uint64_t*)0x20001618 = 0);
    NONFAILING(*(uint32_t*)0x20001620 = 1);
    NONFAILING(*(uint32_t*)0x20001624 = -1);
    NONFAILING(*(uint64_t*)0x20001628 = 0);
    NONFAILING(*(uint64_t*)0x20001630 = 0);
    syscall(__NR_bpf, /*cmd=*/0x19ul, /*arg=*/0x20001600ul, /*size=*/0x38ul);
    break;
  }
}
int main(void)
{
  syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul,
          /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  const char* reason;
  (void)reason;
  install_segv_handler();
  do_sandbox_none();
  return 0;
}