text: /*
   * Copyright (c) 2016-2019 Cisco and/or its affiliates.
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at:
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  #include <unistd.h>
  #include <stdio.h>
  #include <signal.h>
  #include <dlfcn.h>
  #include <pthread.h>
  #include <time.h>
  #include <stdarg.h>
  #include <sys/resource.h>
  #include <netinet/tcp.h>
  
  #include <vcl/ldp_socket_wrapper.h>
  #include <vcl/ldp.h>
  #include <sys/time.h>
  
  #include <vcl/vcl_locked.h>
  #include <vppinfra/time.h>
  #include <vppinfra/bitmap.h>
  #include <vppinfra/lock.h>
  #include <vppinfra/pool.h>
  #include <vppinfra/hash.h>
  
  #define HAVE_CONSTRUCTOR_ATTRIBUTE
  #ifdef HAVE_CONSTRUCTOR_ATTRIBUTE
  #define CONSTRUCTOR_ATTRIBUTE                       \
      __attribute__ ((constructor))
  #else
  #define CONSTRUCTOR_ATTRIBUTE
  #endif /* HAVE_CONSTRUCTOR_ATTRIBUTE */
  
  #define HAVE_DESTRUCTOR_ATTRIBUTE
  #ifdef HAVE_DESTRUCTOR_ATTRIBUTE
  #define DESTRUCTOR_ATTRIBUTE                        \
      __attribute__ ((destructor))
  #else
  #define DESTRUCTOR_ATTRIBUTE
  #endif
  
  #define LDP_MAX_NWORKERS 32
  
  typedef struct ldp_worker_ctx_
  {
    u8 *io_buffer;
    clib_time_t clib_time;
  
    /*
     * Select state
     */
    clib_bitmap_t *rd_bitmap;
    clib_bitmap_t *wr_bitmap;
    clib_bitmap_t *ex_bitmap;
    clib_bitmap_t *si_rd_bitmap;
    clib_bitmap_t *si_wr_bitmap;
    clib_bitmap_t *si_ex_bitmap;
    clib_bitmap_t *libc_rd_bitmap;
    clib_bitmap_t *libc_wr_bitmap;
    clib_bitmap_t *libc_ex_bitmap;
  
    /*
     * Poll state
     */
    vcl_poll_t *vcl_poll;
    struct pollfd *libc_poll;
    u16 *libc_poll_idxs;
  
    /*
     * Epoll state
     */
    u8 epoll_wait_vcl;
    u8 mq_epfd_added;
    int vcl_mq_epfd;
  
  } ldp_worker_ctx_t;
  
  /* clib_bitmap_t, fd_mask and vcl_si_set are used interchangeably. Make sure
   * they are the same size */
  STATIC_ASSERT (sizeof (clib_bitmap_t) == sizeof (fd_mask),
  	       "ldp bitmap size mismatch");
  STATIC_ASSERT (sizeof (vcl_si_set) == sizeof (fd_mask),
  	       "ldp bitmap size mismatch");
  
  typedef struct
  {
    ldp_worker_ctx_t *workers;
    int init;
    char app_name[LDP_APP_NAME_MAX];
    u32 vlsh_bit_val;
    u32 vlsh_bit_mask;
    u32 debug;
    u8 transparent_tls;
  
    /** vcl needs next epoll_create to go to libc_epoll */
    u8 vcl_needs_real_epoll;
  } ldp_main_t;
  
  #define LDP_DEBUG ldp->debug
  
  #define LDBG(_lvl, _fmt, _args...) 					\
    if (ldp->debug > _lvl)						\
      {									\
        int errno_saved = errno;						\
        clib_warning ("ldp<%d>: " _fmt, getpid(), ##_args);		\
        errno = errno_saved;						\
      }
  
  static ldp_main_t ldp_main = {
    .vlsh_bit_val = (1 << LDP_SID_BIT_MIN),
    .vlsh_bit_mask = (1 << LDP_SID_BIT_MIN) - 1,
    .debug = LDP_DEBUG_INIT,
    .transparent_tls = 0,
  };
  
  static ldp_main_t *ldp = &ldp_main;
  
  static inline ldp_worker_ctx_t *
  ldp_worker_get_current (void)
  {
    return (ldp->workers + vppcom_worker_index ());
  }
  
  /*
   * RETURN:  0 on success or -1 on error.
   * */
  static inline void
  ldp_set_app_name (char *app_name)
  {
    snprintf (ldp->app_name, LDP_APP_NAME_MAX,
  	    "ldp-%d-%s", getpid (), app_name);
  }
  
  static inline char *
  ldp_get_app_name ()
  {
    if (ldp->app_name[0] == '\0')
      ldp_set_app_name ("app");
  
    return ldp->app_name;
  }
  
  static inline int
  ldp_vlsh_to_fd (vls_handle_t vlsh)
  {
    return (vlsh + ldp->vlsh_bit_val);
  }
  
  static inline vls_handle_t
  ldp_fd_to_vlsh (int fd)
  {
    if (fd < ldp->vlsh_bit_val)
      return VLS_INVALID_HANDLE;
  
    return (fd - ldp->vlsh_bit_val);
  }
  
  static void
  ldp_alloc_workers (void)
  {
    if (ldp->workers)
      return;
    pool_alloc (ldp->workers, LDP_MAX_NWORKERS);
  }
  
  static inline int
  ldp_init (void)
  {
    ldp_worker_ctx_t *ldpw;
    int rv;
  
    if (PREDICT_TRUE (ldp->init))
      return 0;
  
    ldp->init = 1;
    ldp->vcl_needs_real_epoll = 1;
    rv = vls_app_create (ldp_get_app_name ());
    if (rv != VPPCOM_OK)
      {
        ldp->vcl_needs_real_epoll = 0;
        if (rv == VPPCOM_EEXIST)
  	return 0;
        LDBG (2, "\nERROR: ldp_init: vppcom_app_create()"
  	    " failed!  rv = %d (%s)\n", rv, vppcom_retval_str (rv));
        ldp->init = 0;
        return rv;
      }
    ldp->vcl_needs_real_epoll = 0;
    ldp_alloc_workers ();
    ldpw = ldp_worker_get_current ();
  
    char *env_var_str = getenv (LDP_ENV_DEBUG);
    if (env_var_str)
      {
        u32 tmp;
        if (sscanf (env_var_str, "%u", &tmp) != 1)
  	clib_warning ("LDP<%d>: WARNING: Invalid LDP debug level specified in"
  		      " the env var " LDP_ENV_DEBUG " (%s)!", getpid (),
  		      env_var_str);
        else
  	{
  	  ldp->debug = tmp;
  	  LDBG (0, "configured LDP debug level (%u) from env var "
  		LDP_ENV_DEBUG "!", ldp->debug);
  	}
      }
  
    env_var_str = getenv (LDP_ENV_APP_NAME);
    if (env_var_str)
      {
        ldp_set_app_name (env_var_str);
        LDBG (0, "configured LDP app name (%s) from the env var "
  	    LDP_ENV_APP_NAME "!", ldp->app_name);
      }
  
    env_var_str = getenv (LDP_ENV_SID_BIT);
    if (env_var_str)
      {
        u32 sb;
        if (sscanf (env_var_str, "%u", &sb) != 1)
  	{
  	  LDBG (0, "WARNING: Invalid LDP sid bit specified in the env var "
  		LDP_ENV_SID_BIT " (%s)! sid bit value %d (0x%x)", env_var_str,
  		ldp->vlsh_bit_val, ldp->vlsh_bit_val);
  	}
        else if (sb < LDP_SID_BIT_MIN)
  	{
  	  ldp->vlsh_bit_val = (1 << LDP_SID_BIT_MIN);
  	  ldp->vlsh_bit_mask = ldp->vlsh_bit_val - 1;
  
  	  LDBG (0, "WARNING: LDP sid bit (%u) specified in the env var "
  		LDP_ENV_SID_BIT " (%s) is too small. Using LDP_SID_BIT_MIN"
  		" (%d)! sid bit value %d (0x%x)", sb, env_var_str,
  		LDP_SID_BIT_MIN, ldp->vlsh_bit_val, ldp->vlsh_bit_val);
  	}
        else if (sb > LDP_SID_BIT_MAX)
  	{
  	  ldp->vlsh_bit_val = (1 << LDP_SID_BIT_MAX);
  	  ldp->vlsh_bit_mask = ldp->vlsh_bit_val - 1;
  
  	  LDBG (0, "WARNING: LDP sid bit (%u) specified in the env var "
  		LDP_ENV_SID_BIT " (%s) is too big. Using LDP_SID_BIT_MAX"
  		" (%d)! sid bit value %d (0x%x)", sb, env_var_str,
  		LDP_SID_BIT_MAX, ldp->vlsh_bit_val, ldp->vlsh_bit_val);
  	}
        else
  	{
  	  ldp->vlsh_bit_val = (1 << sb);
  	  ldp->vlsh_bit_mask = ldp->vlsh_bit_val - 1;
  
  	  LDBG (0, "configured LDP sid bit (%u) from "
  		LDP_ENV_SID_BIT "!  sid bit value %d (0x%x)", sb,
  		ldp->vlsh_bit_val, ldp->vlsh_bit_val);
  	}
  
        /* Make sure there are enough bits in the fd set for vcl sessions */
        if (ldp->vlsh_bit_val > FD_SETSIZE / 2)
  	{
  	  LDBG (0, "ERROR: LDP vlsh bit value %d > FD_SETSIZE/2 %d!",
  		ldp->vlsh_bit_val, FD_SETSIZE / 2);
  	  ldp->init = 0;
  	  return -1;
  	}
      }
    env_var_str = getenv (LDP_ENV_TLS_TRANS);
    if (env_var_str)
      {
        ldp->transparent_tls = 1;
      }
  
    /* *INDENT-OFF* */
    pool_foreach (ldpw, ldp->workers, ({
      clib_memset (&ldpw->clib_time, 0, sizeof (ldpw->clib_time));
    }));
    /* *INDENT-ON* */
  
    LDBG (0, "LDP initialization: done!");
  
    return 0;
  }
  
  int
  close (int fd)
  {
    vls_handle_t vlsh;
    int rv, epfd;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        epfd = vls_attr (vlsh, VPPCOM_ATTR_GET_LIBC_EPFD, 0, 0);
        if (epfd > 0)
  	{
  	  LDBG (0, "fd %d: calling libc_close: epfd %u", fd, epfd);
  
  	  rv = libc_close (epfd);
  	  if (rv < 0)
  	    {
  	      u32 size = sizeof (epfd);
  	      epfd = 0;
  
  	      (void) vls_attr (vlsh, VPPCOM_ATTR_SET_LIBC_EPFD, &epfd, &size);
  	    }
  	}
        else if (PREDICT_FALSE (epfd < 0))
  	{
  	  errno = -epfd;
  	  rv = -1;
  	  goto done;
  	}
  
        LDBG (0, "fd %d: calling vls_close: vlsh %u", fd, vlsh);
  
        rv = vls_close (vlsh);
        if (rv != VPPCOM_OK)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
        LDBG (0, "fd %d: calling libc_close", fd);
        rv = libc_close (fd);
      }
  
  done:
    return rv;
  }
  
  ssize_t
  read (int fd, void *buf, size_t nbytes)
  {
    vls_handle_t vlsh;
    ssize_t size;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        size = vls_read (vlsh, buf, nbytes);
        if (size < 0)
  	{
  	  errno = -size;
  	  size = -1;
  	}
      }
    else
      {
        size = libc_read (fd, buf, nbytes);
      }
  
    return size;
  }
  
  ssize_t
  readv (int fd, const struct iovec * iov, int iovcnt)
  {
    int rv = 0, i, total = 0;
    vls_handle_t vlsh;
    ssize_t size = 0;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        for (i = 0; i < iovcnt; ++i)
  	{
  	  rv = vls_read (vlsh, iov[i].iov_base, iov[i].iov_len);
  	  if (rv <= 0)
  	    break;
  	  else
  	    {
  	      total += rv;
  	      if (rv < iov[i].iov_len)
  		break;
  	    }
  	}
        if (rv < 0 && total == 0)
  	{
  	  errno = -rv;
  	  size = -1;
  	}
        else
  	size = total;
      }
    else
      {
        size = libc_readv (fd, iov, iovcnt);
      }
  
    return size;
  }
  
  ssize_t
  write (int fd, const void *buf, size_t nbytes)
  {
    vls_handle_t vlsh;
    ssize_t size = 0;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        size = vls_write_msg (vlsh, (void *) buf, nbytes);
        if (size < 0)
  	{
  	  errno = -size;
  	  size = -1;
  	}
      }
    else
      {
        size = libc_write (fd, buf, nbytes);
      }
  
    return size;
  }
  
  ssize_t
  writev (int fd, const struct iovec * iov, int iovcnt)
  {
    ssize_t size = 0, total = 0;
    vls_handle_t vlsh;
    int i, rv = 0;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        for (i = 0; i < iovcnt; ++i)
  	{
  	  rv = vls_write_msg (vlsh, iov[i].iov_base, iov[i].iov_len);
  	  if (rv < 0)
  	    break;
  	  else
  	    {
  	      total += rv;
  	      if (rv < iov[i].iov_len)
  		break;
  	    }
  	}
  
        if (rv < 0 && total == 0)
  	{
  	  errno = -rv;
  	  size = -1;
  	}
        else
  	size = total;
      }
    else
      {
        size = libc_writev (fd, iov, iovcnt);
      }
  
    return size;
  }
  
  static int
  fcntl_internal (int fd, int cmd, va_list ap)
  {
    vls_handle_t vlsh;
    int rv = 0;
  
    vlsh = ldp_fd_to_vlsh (fd);
    LDBG (0, "fd %u vlsh %d, cmd %u", fd, vlsh, cmd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        int flags = va_arg (ap, int);
        u32 size;
  
        size = sizeof (flags);
        rv = -EOPNOTSUPP;
        switch (cmd)
  	{
  	case F_SETFL:
  	  rv = vls_attr (vlsh, VPPCOM_ATTR_SET_FLAGS, &flags, &size);
  	  break;
  
  	case F_GETFL:
  	  rv = vls_attr (vlsh, VPPCOM_ATTR_GET_FLAGS, &flags, &size);
  	  if (rv == VPPCOM_OK)
  	    rv = flags;
  	  break;
  	case F_SETFD:
  	  /* TODO handle this */
  	  LDBG (0, "F_SETFD ignored flags %u", flags);
  	  rv = 0;
  	  break;
  	default:
  	  rv = -EOPNOTSUPP;
  	  break;
  	}
        if (rv < 0)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
  #ifdef HAVE_FCNTL64
        rv = libc_vfcntl64 (fd, cmd, ap);
  #else
        rv = libc_vfcntl (fd, cmd, ap);
  #endif
      }
  
    return rv;
  }
  
  int
  fcntl (int fd, int cmd, ...)
  {
    va_list ap;
    int rv;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    va_start (ap, cmd);
    rv = fcntl_internal (fd, cmd, ap);
    va_end (ap);
  
    return rv;
  }
  
  int
  fcntl64 (int fd, int cmd, ...)
  {
    va_list ap;
    int rv;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    va_start (ap, cmd);
    rv = fcntl_internal (fd, cmd, ap);
    va_end (ap);
    return rv;
  }
  
  int
  ioctl (int fd, unsigned long int cmd, ...)
  {
    vls_handle_t vlsh;
    va_list ap;
    int rv;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    va_start (ap, cmd);
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        switch (cmd)
  	{
  	case FIONREAD:
  	  rv = vls_attr (vlsh, VPPCOM_ATTR_GET_NREAD, 0, 0);
  	  break;
  
  	case FIONBIO:
  	  {
  	    u32 flags = va_arg (ap, int) ? O_NONBLOCK : 0;
  	    u32 size = sizeof (flags);
  
  	    /* TBD: When VPPCOM_ATTR_[GS]ET_FLAGS supports flags other than
  	     *      non-blocking, the flags should be read here and merged
  	     *      with O_NONBLOCK.
  	     */
  	    rv = vls_attr (vlsh, VPPCOM_ATTR_SET_FLAGS, &flags, &size);
  	  }
  	  break;
  
  	default:
  	  rv = -EOPNOTSUPP;
  	  break;
  	}
        if (rv < 0)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
        rv = libc_vioctl (fd, cmd, ap);
      }
  
    va_end (ap);
    return rv;
  }
  
  always_inline void
  ldp_select_init_maps (fd_set * __restrict original,
  		      clib_bitmap_t ** resultb, clib_bitmap_t ** libcb,
  		      clib_bitmap_t ** vclb, int nfds, u32 minbits,
  		      u32 n_bytes, uword * si_bits, uword * libc_bits)
  {
    uword si_bits_set, libc_bits_set;
    vls_handle_t vlsh;
    int fd;
  
    clib_bitmap_validate (*vclb, minbits);
    clib_bitmap_validate (*libcb, minbits);
    clib_bitmap_validate (*resultb, minbits);
    clib_memcpy_fast (*resultb, original, n_bytes);
    memset (original, 0, n_bytes);
  
    /* *INDENT-OFF* */
    clib_bitmap_foreach (fd, *resultb, ({
      if (fd > nfds)
        break;
      vlsh = ldp_fd_to_vlsh (fd);
      if (vlsh == VLS_INVALID_HANDLE)
        clib_bitmap_set_no_check (*libcb, fd, 1);
      else
        *vclb = clib_bitmap_set (*vclb, vlsh_to_session_index (vlsh), 1);
    }));
    /* *INDENT-ON* */
  
    si_bits_set = clib_bitmap_last_set (*vclb) + 1;
    *si_bits = (si_bits_set > *si_bits) ? si_bits_set : *si_bits;
    clib_bitmap_validate (*resultb, *si_bits);
  
    libc_bits_set = clib_bitmap_last_set (*libcb) + 1;
    *libc_bits = (libc_bits_set > *libc_bits) ? libc_bits_set : *libc_bits;
  }
  
  always_inline int
  ldp_select_vcl_map_to_libc (clib_bitmap_t * vclb, fd_set * __restrict libcb)
  {
    vls_handle_t vlsh;
    uword si;
    int fd;
  
    if (!libcb)
      return 0;
  
    /* *INDENT-OFF* */
    clib_bitmap_foreach (si, vclb, ({
      vlsh = vls_session_index_to_vlsh (si);
      ASSERT (vlsh != VLS_INVALID_HANDLE);
      fd = ldp_vlsh_to_fd (vlsh);
      if (PREDICT_FALSE (fd < 0))
        {
          errno = EBADFD;
          return -1;
        }
      FD_SET (fd, libcb);
    }));
    /* *INDENT-ON* */
  
    return 0;
  }
  
  always_inline void
  ldp_select_libc_map_merge (clib_bitmap_t * result, fd_set * __restrict libcb)
  {
    uword fd;
  
    if (!libcb)
      return;
  
    /* *INDENT-OFF* */
    clib_bitmap_foreach (fd, result, ({
      FD_SET ((int)fd, libcb);
    }));
    /* *INDENT-ON* */
  }
  
  int
  ldp_pselect (int nfds, fd_set * __restrict readfds,
  	     fd_set * __restrict writefds,
  	     fd_set * __restrict exceptfds,
  	     const struct timespec *__restrict timeout,
  	     const __sigset_t * __restrict sigmask)
  {
    u32 minbits = clib_max (nfds, BITS (uword)), n_bytes;
    ldp_worker_ctx_t *ldpw = ldp_worker_get_current ();
    struct timespec libc_tspec = { 0 };
    f64 time_out, vcl_timeout = 0;
    uword si_bits, libc_bits;
    int rv, bits_set = 0;
  
    if (nfds < 0)
      {
        errno = EINVAL;
        return -1;
      }
  
    if (PREDICT_FALSE (ldpw->clib_time.init_cpu_time == 0))
      clib_time_init (&ldpw->clib_time);
  
    if (timeout)
      {
        time_out = (timeout->tv_sec == 0 && timeout->tv_nsec == 0) ?
  	(f64) 0 : (f64) timeout->tv_sec + (f64) timeout->tv_nsec / (f64) 1e9;
  
        /* select as fine grained sleep */
        if (!nfds)
  	{
  	  time_out += clib_time_now (&ldpw->clib_time);
  	  while (clib_time_now (&ldpw->clib_time) < time_out)
  	    ;
  	  return 0;
  	}
      }
    else if (!nfds)
      {
        errno = EINVAL;
        return -1;
      }
    else
      time_out = -1;
  
    if (nfds <= ldp->vlsh_bit_val)
      {
        rv = libc_pselect (nfds, readfds, writefds, exceptfds,
  			 timeout, sigmask);
        goto done;
      }
  
    si_bits = libc_bits = 0;
    n_bytes = nfds / 8 + ((nfds % 8) ? 1 : 0);
  
    if (readfds)
      ldp_select_init_maps (readfds, &ldpw->rd_bitmap, &ldpw->libc_rd_bitmap,
  			  &ldpw->si_rd_bitmap, nfds, minbits, n_bytes,
  			  &si_bits, &libc_bits);
    if (writefds)
      ldp_select_init_maps (writefds, &ldpw->wr_bitmap,
  			  &ldpw->libc_wr_bitmap, &ldpw->si_wr_bitmap, nfds,
  			  minbits, n_bytes, &si_bits, &libc_bits);
    if (exceptfds)
      ldp_select_init_maps (exceptfds, &ldpw->ex_bitmap,
  			  &ldpw->libc_ex_bitmap, &ldpw->si_ex_bitmap, nfds,
  			  minbits, n_bytes, &si_bits, &libc_bits);
  
    if (PREDICT_FALSE (!si_bits && !libc_bits))
      {
        errno = EINVAL;
        rv = -1;
        goto done;
      }
  
    if (!si_bits)
      libc_tspec = timeout ? *timeout : libc_tspec;
  
    do
      {
        if (si_bits)
  	{
  	  if (readfds)
  	    clib_memcpy_fast (ldpw->rd_bitmap, ldpw->si_rd_bitmap,
  			      vec_len (ldpw->si_rd_bitmap) *
  			      sizeof (clib_bitmap_t));
  	  if (writefds)
  	    clib_memcpy_fast (ldpw->wr_bitmap, ldpw->si_wr_bitmap,
  			      vec_len (ldpw->si_wr_bitmap) *
  			      sizeof (clib_bitmap_t));
  	  if (exceptfds)
  	    clib_memcpy_fast (ldpw->ex_bitmap, ldpw->si_ex_bitmap,
  			      vec_len (ldpw->si_ex_bitmap) *
  			      sizeof (clib_bitmap_t));
  
  	  rv = vls_select (si_bits, readfds ? ldpw->rd_bitmap : NULL,
  			   writefds ? ldpw->wr_bitmap : NULL,
  			   exceptfds ? ldpw->ex_bitmap : NULL, vcl_timeout);
  	  if (rv < 0)
  	    {
  	      errno = -rv;
  	      rv = -1;
  	      goto done;
  	    }
  	  else if (rv > 0)
  	    {
  	      if (ldp_select_vcl_map_to_libc (ldpw->rd_bitmap, readfds))
  		{
  		  rv = -1;
  		  goto done;
  		}
  
  	      if (ldp_select_vcl_map_to_libc (ldpw->wr_bitmap, writefds))
  		{
  		  rv = -1;
  		  goto done;
  		}
  
  	      if (ldp_select_vcl_map_to_libc (ldpw->ex_bitmap, exceptfds))
  		{
  		  rv = -1;
  		  goto done;
  		}
  	      bits_set = rv;
  	    }
  	}
        if (libc_bits)
  	{
  	  if (readfds)
  	    clib_memcpy_fast (ldpw->rd_bitmap, ldpw->libc_rd_bitmap,
  			      vec_len (ldpw->libc_rd_bitmap) *
  			      sizeof (clib_bitmap_t));
  	  if (writefds)
  	    clib_memcpy_fast (ldpw->wr_bitmap, ldpw->libc_wr_bitmap,
  			      vec_len (ldpw->libc_wr_bitmap) *
  			      sizeof (clib_bitmap_t));
  	  if (exceptfds)
  	    clib_memcpy_fast (ldpw->ex_bitmap, ldpw->libc_ex_bitmap,
  			      vec_len (ldpw->libc_ex_bitmap) *
  			      sizeof (clib_bitmap_t));
  
  	  rv = libc_pselect (libc_bits,
  			     readfds ? (fd_set *) ldpw->rd_bitmap : NULL,
  			     writefds ? (fd_set *) ldpw->wr_bitmap : NULL,
  			     exceptfds ? (fd_set *) ldpw->ex_bitmap : NULL,
  			     &libc_tspec, sigmask);
  	  if (rv > 0)
  	    {
  	      ldp_select_libc_map_merge (ldpw->rd_bitmap, readfds);
  	      ldp_select_libc_map_merge (ldpw->wr_bitmap, writefds);
  	      ldp_select_libc_map_merge (ldpw->ex_bitmap, exceptfds);
  	      bits_set += rv;
  	    }
  	}
  
        if (bits_set)
  	{
  	  rv = bits_set;
  	  goto done;
  	}
      }
    while ((time_out == -1) || (clib_time_now (&ldpw->clib_time) < time_out));
    rv = 0;
  
  done:
    /* TBD: set timeout to amount of time left */
    clib_bitmap_zero (ldpw->rd_bitmap);
    clib_bitmap_zero (ldpw->si_rd_bitmap);
    clib_bitmap_zero (ldpw->libc_rd_bitmap);
    clib_bitmap_zero (ldpw->wr_bitmap);
    clib_bitmap_zero (ldpw->si_wr_bitmap);
    clib_bitmap_zero (ldpw->libc_wr_bitmap);
    clib_bitmap_zero (ldpw->ex_bitmap);
    clib_bitmap_zero (ldpw->si_ex_bitmap);
    clib_bitmap_zero (ldpw->libc_ex_bitmap);
  
    return rv;
  }
  
  int
  select (int nfds, fd_set * __restrict readfds,
  	fd_set * __restrict writefds,
  	fd_set * __restrict exceptfds, struct timeval *__restrict timeout)
  {
    struct timespec tspec;
  
    if (timeout)
      {
        tspec.tv_sec = timeout->tv_sec;
        tspec.tv_nsec = timeout->tv_usec * 1000;
      }
    return ldp_pselect (nfds, readfds, writefds, exceptfds,
  		      timeout ? &tspec : NULL, NULL);
  }
  
  #ifdef __USE_XOPEN2K
  int
  pselect (int nfds, fd_set * __restrict readfds,
  	 fd_set * __restrict writefds,
  	 fd_set * __restrict exceptfds,
  	 const struct timespec *__restrict timeout,
  	 const __sigset_t * __restrict sigmask)
  {
    return ldp_pselect (nfds, readfds, writefds, exceptfds, timeout, 0);
  }
  #endif
  
  /* If transparent TLS mode is turned on, then ldp will load key and cert.
   */
  static int
  load_tls_cert (vls_handle_t vlsh)
  {
    char *env_var_str = getenv (LDP_ENV_TLS_CERT);
    char inbuf[4096];
    char *tls_cert;
    int cert_size;
    FILE *fp;
  
    if (env_var_str)
      {
        fp = fopen (env_var_str, "r");
        if (fp == NULL)
  	{
  	  LDBG (0, "ERROR: failed to open cert file %s \n", env_var_str);
  	  return -1;
  	}
        cert_size = fread (inbuf, sizeof (char), sizeof (inbuf), fp);
        tls_cert = inbuf;
        vppcom_session_tls_add_cert (vlsh_to_session_index (vlsh), tls_cert,
  				   cert_size);
        fclose (fp);
      }
    else
      {
        LDBG (0, "ERROR: failed to read LDP environment %s\n",
  	    LDP_ENV_TLS_CERT);
        return -1;
      }
    return 0;
  }
  
  static int
  load_tls_key (vls_handle_t vlsh)
  {
    char *env_var_str = getenv (LDP_ENV_TLS_KEY);
    char inbuf[4096];
    char *tls_key;
    int key_size;
    FILE *fp;
  
    if (env_var_str)
      {
        fp = fopen (env_var_str, "r");
        if (fp == NULL)
  	{
  	  LDBG (0, "ERROR: failed to open key file %s \n", env_var_str);
  	  return -1;
  	}
        key_size = fread (inbuf, sizeof (char), sizeof (inbuf), fp);
        tls_key = inbuf;
        vppcom_session_tls_add_key (vlsh_to_session_index (vlsh), tls_key,
  				  key_size);
        fclose (fp);
      }
    else
      {
        LDBG (0, "ERROR: failed to read LDP environment %s\n", LDP_ENV_TLS_KEY);
        return -1;
      }
    return 0;
  }
  
  int
  socket (int domain, int type, int protocol)
  {
    int rv, sock_type = type & ~(SOCK_CLOEXEC | SOCK_NONBLOCK);
    u8 is_nonblocking = type & SOCK_NONBLOCK ? 1 : 0;
    vls_handle_t vlsh;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (((domain == AF_INET) || (domain == AF_INET6)) &&
        ((sock_type == SOCK_STREAM) || (sock_type == SOCK_DGRAM)))
      {
        u8 proto;
        if (ldp->transparent_tls)
  	{
  	  proto = VPPCOM_PROTO_TLS;
  	}
        else
  	proto = ((sock_type == SOCK_DGRAM) ?
  		 VPPCOM_PROTO_UDP : VPPCOM_PROTO_TCP);
  
        LDBG (0, "calling vls_create: proto %u (%s), is_nonblocking %u",
  	    proto, vppcom_proto_str (proto), is_nonblocking);
  
        vlsh = vls_create (proto, is_nonblocking);
        if (vlsh < 0)
  	{
  	  errno = -vlsh;
  	  rv = -1;
  	}
        else
  	{
  	  if (ldp->transparent_tls)
  	    {
  	      if (load_tls_cert (vlsh) < 0 || load_tls_key (vlsh) < 0)
  		{
  		  return -1;
  		}
  	    }
  	  rv = ldp_vlsh_to_fd (vlsh);
  	}
      }
    else
      {
        LDBG (0, "calling libc_socket");
        rv = libc_socket (domain, type, protocol);
      }
  
    return rv;
  }
  
  /*
   * Create two new sockets, of type TYPE in domain DOMAIN and using
   * protocol PROTOCOL, which are connected to each other, and put file
   * descriptors for them in FDS[0] and FDS[1].  If PROTOCOL is zero,
   * one will be chosen automatically.
   * Returns 0 on success, -1 for errors.
   * */
  int
  socketpair (int domain, int type, int protocol, int fds[2])
  {
    int rv, sock_type = type & ~(SOCK_CLOEXEC | SOCK_NONBLOCK);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (((domain == AF_INET) || (domain == AF_INET6)) &&
        ((sock_type == SOCK_STREAM) || (sock_type == SOCK_DGRAM)))
      {
        LDBG (0, "LDP-TBD");
        errno = ENOSYS;
        rv = -1;
      }
    else
      {
        LDBG (1, "calling libc_socketpair");
        rv = libc_socketpair (domain, type, protocol, fds);
      }
  
    return rv;
  }
  
  int
  bind (int fd, __CONST_SOCKADDR_ARG addr, socklen_t len)
  {
    vls_handle_t vlsh;
    int rv;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        vppcom_endpt_t ep;
  
        switch (addr->sa_family)
  	{
  	case AF_INET:
  	  if (len != sizeof (struct sockaddr_in))
  	    {
  	      LDBG (0, "ERROR: fd %d: vlsh %u: Invalid AF_INET addr len %u!",
  		    fd, vlsh, len);
  	      errno = EINVAL;
  	      rv = -1;
  	      goto done;
  	    }
  	  ep.is_ip4 = VPPCOM_IS_IP4;
  	  ep.ip = (u8 *) & ((const struct sockaddr_in *) addr)->sin_addr;
  	  ep.port = (u16) ((const struct sockaddr_in *) addr)->sin_port;
  	  break;
  
  	case AF_INET6:
  	  if (len != sizeof (struct sockaddr_in6))
  	    {
  	      LDBG (0, "ERROR: fd %d: vlsh %u: Invalid AF_INET6 addr len %u!",
  		    fd, vlsh, len);
  	      errno = EINVAL;
  	      rv = -1;
  	      goto done;
  	    }
  	  ep.is_ip4 = VPPCOM_IS_IP6;
  	  ep.ip = (u8 *) & ((const struct sockaddr_in6 *) addr)->sin6_addr;
  	  ep.port = (u16) ((const struct sockaddr_in6 *) addr)->sin6_port;
  	  break;
  
  	default:
  	  LDBG (0, "ERROR: fd %d: vlsh %u: Unsupported address family %u!",
  		fd, vlsh, addr->sa_family);
  	  errno = EAFNOSUPPORT;
  	  rv = -1;
  	  goto done;
  	}
        LDBG (0, "fd %d: calling vls_bind: vlsh %u, addr %p, len %u", fd, vlsh,
  	    addr, len);
  
        rv = vls_bind (vlsh, &ep);
        if (rv != VPPCOM_OK)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
        LDBG (0, "fd %d: calling libc_bind: addr %p, len %u", fd, addr, len);
        rv = libc_bind (fd, addr, len);
      }
  
  done:
    LDBG (1, "fd %d: returning %d", fd, rv);
  
    return rv;
  }
  
  static inline int
  ldp_copy_ep_to_sockaddr (__SOCKADDR_ARG addr, socklen_t * __restrict len,
  			 vppcom_endpt_t * ep)
  {
    int rv = 0;
    int sa_len, copy_len;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (addr && len && ep)
      {
        addr->sa_family = (ep->is_ip4 == VPPCOM_IS_IP4) ? AF_INET : AF_INET6;
        switch (addr->sa_family)
  	{
  	case AF_INET:
  	  ((struct sockaddr_in *) addr)->sin_port = ep->port;
  	  if (*len > sizeof (struct sockaddr_in))
  	    *len = sizeof (struct sockaddr_in);
  	  sa_len = sizeof (struct sockaddr_in) - sizeof (struct in_addr);
  	  copy_len = *len - sa_len;
  	  if (copy_len > 0)
  	    memcpy (&((struct sockaddr_in *) addr)->sin_addr, ep->ip,
  		    copy_len);
  	  break;
  
  	case AF_INET6:
  	  ((struct sockaddr_in6 *) addr)->sin6_port = ep->port;
  	  if (*len > sizeof (struct sockaddr_in6))
  	    *len = sizeof (struct sockaddr_in6);
  	  sa_len = sizeof (struct sockaddr_in6) - sizeof (struct in6_addr);
  	  copy_len = *len - sa_len;
  	  if (copy_len > 0)
  	    memcpy (((struct sockaddr_in6 *) addr)->sin6_addr.
  		    __in6_u.__u6_addr8, ep->ip, copy_len);
  	  break;
  
  	default:
  	  /* Not possible */
  	  rv = -EAFNOSUPPORT;
  	  break;
  	}
      }
    return rv;
  }
  
  int
  getsockname (int fd, __SOCKADDR_ARG addr, socklen_t * __restrict len)
  {
    vls_handle_t vlsh;
    int rv;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        vppcom_endpt_t ep;
        u8 addr_buf[sizeof (struct in6_addr)];
        u32 size = sizeof (ep);
  
        ep.ip = addr_buf;
  
        rv = vls_attr (vlsh, VPPCOM_ATTR_GET_LCL_ADDR, &ep, &size);
        if (rv != VPPCOM_OK)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
        else
  	{
  	  rv = ldp_copy_ep_to_sockaddr (addr, len, &ep);
  	  if (rv != VPPCOM_OK)
  	    {
  	      errno = -rv;
  	      rv = -1;
  	    }
  	}
      }
    else
      {
        rv = libc_getsockname (fd, addr, len);
      }
  
    return rv;
  }
  
  int
  connect (int fd, __CONST_SOCKADDR_ARG addr, socklen_t len)
  {
    vls_handle_t vlsh;
    int rv;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (!addr)
      {
        LDBG (0, "ERROR: fd %d: NULL addr, len %u", fd, len);
        errno = EINVAL;
        rv = -1;
        goto done;
      }
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        vppcom_endpt_t ep;
  
        switch (addr->sa_family)
  	{
  	case AF_INET:
  	  if (len != sizeof (struct sockaddr_in))
  	    {
  	      LDBG (0, "fd %d: ERROR vlsh %u: Invalid AF_INET addr len %u!",
  		    fd, vlsh, len);
  	      errno = EINVAL;
  	      rv = -1;
  	      goto done;
  	    }
  	  ep.is_ip4 = VPPCOM_IS_IP4;
  	  ep.ip = (u8 *) & ((const struct sockaddr_in *) addr)->sin_addr;
  	  ep.port = (u16) ((const struct sockaddr_in *) addr)->sin_port;
  	  break;
  
  	case AF_INET6:
  	  if (len != sizeof (struct sockaddr_in6))
  	    {
  	      LDBG (0, "fd %d: ERROR vlsh %u: Invalid AF_INET6 addr len %u!",
  		    fd, vlsh, len);
  	      errno = EINVAL;
  	      rv = -1;
  	      goto done;
  	    }
  	  ep.is_ip4 = VPPCOM_IS_IP6;
  	  ep.ip = (u8 *) & ((const struct sockaddr_in6 *) addr)->sin6_addr;
  	  ep.port = (u16) ((const struct sockaddr_in6 *) addr)->sin6_port;
  	  break;
  
  	default:
  	  LDBG (0, "fd %d: ERROR vlsh %u: Unsupported address family %u!",
  		fd, vlsh, addr->sa_family);
  	  errno = EAFNOSUPPORT;
  	  rv = -1;
  	  goto done;
  	}
        LDBG (0, "fd %d: calling vls_connect(): vlsh %u addr %p len %u", fd,
  	    vlsh, addr, len);
  
        rv = vls_connect (vlsh, &ep);
        if (rv != VPPCOM_OK)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
        LDBG (0, "fd %d: calling libc_connect(): addr %p, len %u",
  	    fd, addr, len);
  
        rv = libc_connect (fd, addr, len);
      }
  
  done:
    LDBG (1, "fd %d: returning %d (0x%x)", fd, rv, rv);
    return rv;
  }
  
  int
  getpeername (int fd, __SOCKADDR_ARG addr, socklen_t * __restrict len)
  {
    vls_handle_t vlsh;
    int rv;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        vppcom_endpt_t ep;
        u8 addr_buf[sizeof (struct in6_addr)];
        u32 size = sizeof (ep);
  
        ep.ip = addr_buf;
        rv = vls_attr (vlsh, VPPCOM_ATTR_GET_PEER_ADDR, &ep, &size);
        if (rv != VPPCOM_OK)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
        else
  	{
  	  rv = ldp_copy_ep_to_sockaddr (addr, len, &ep);
  	  if (rv != VPPCOM_OK)
  	    {
  	      errno = -rv;
  	      rv = -1;
  	    }
  	}
      }
    else
      {
        rv = libc_getpeername (fd, addr, len);
      }
  
    return rv;
  }
  
  ssize_t
  send (int fd, const void *buf, size_t n, int flags)
  {
    vls_handle_t vlsh = ldp_fd_to_vlsh (fd);
    ssize_t size;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (vlsh != VLS_INVALID_HANDLE)
      {
        size = vls_sendto (vlsh, (void *) buf, n, flags, NULL);
        if (size < VPPCOM_OK)
  	{
  	  errno = -size;
  	  size = -1;
  	}
      }
    else
      {
        size = libc_send (fd, buf, n, flags);
      }
  
    return size;
  }
  
  ssize_t
  sendfile (int out_fd, int in_fd, off_t * offset, size_t len)
  {
    ldp_worker_ctx_t *ldpw = ldp_worker_get_current ();
    vls_handle_t vlsh;
    ssize_t size = 0;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (out_fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        int rv;
        ssize_t results = 0;
        size_t n_bytes_left = len;
        size_t bytes_to_read;
        int nbytes;
        u8 eagain = 0;
        u32 flags, flags_len = sizeof (flags);
  
        rv = vls_attr (vlsh, VPPCOM_ATTR_GET_FLAGS, &flags, &flags_len);
        if (PREDICT_FALSE (rv != VPPCOM_OK))
  	{
  	  LDBG (0, "ERROR: out fd %d: vls_attr: vlsh %u, returned %d (%s)!",
  		out_fd, vlsh, rv, vppcom_retval_str (rv));
  
  	  vec_reset_length (ldpw->io_buffer);
  	  errno = -rv;
  	  size = -1;
  	  goto done;
  	}
  
        if (offset)
  	{
  	  off_t off = lseek (in_fd, *offset, SEEK_SET);
  	  if (PREDICT_FALSE (off == -1))
  	    {
  	      size = -1;
  	      goto done;
  	    }
  
  	  ASSERT (off == *offset);
  	}
  
        do
  	{
  	  size = vls_attr (vlsh, VPPCOM_ATTR_GET_NWRITE, 0, 0);
  	  if (size < 0)
  	    {
  	      LDBG (0, "ERROR: fd %d: vls_attr: vlsh %u returned %d (%s)!",
  		    out_fd, vlsh, size, vppcom_retval_str (size));
  	      vec_reset_length (ldpw->io_buffer);
  	      errno = -size;
  	      size = -1;
  	      goto done;
  	    }
  
  	  bytes_to_read = size;
  	  if (bytes_to_read == 0)
  	    {
  	      if (flags & O_NONBLOCK)
  		{
  		  if (!results)
  		    eagain = 1;
  		  goto update_offset;
  		}
  	      else
  		continue;
  	    }
  	  bytes_to_read = clib_min (n_bytes_left, bytes_to_read);
  	  vec_validate (ldpw->io_buffer, bytes_to_read);
  	  nbytes = libc_read (in_fd, ldpw->io_buffer, bytes_to_read);
  	  if (nbytes < 0)
  	    {
  	      if (results == 0)
  		{
  		  vec_reset_length (ldpw->io_buffer);
  		  size = -1;
  		  goto done;
  		}
  	      goto update_offset;
  	    }
  
  	  size = vls_write (vlsh, ldpw->io_buffer, nbytes);
  	  if (size < 0)
  	    {
  	      if (size == VPPCOM_EAGAIN)
  		{
  		  if (flags & O_NONBLOCK)
  		    {
  		      if (!results)
  			eagain = 1;
  		      goto update_offset;
  		    }
  		  else
  		    continue;
  		}
  	      if (results == 0)
  		{
  		  vec_reset_length (ldpw->io_buffer);
  		  errno = -size;
  		  size = -1;
  		  goto done;
  		}
  	      goto update_offset;
  	    }
  
  	  results += nbytes;
  	  ASSERT (n_bytes_left >= nbytes);
  	  n_bytes_left = n_bytes_left - nbytes;
  	}
        while (n_bytes_left > 0);
  
      update_offset:
        vec_reset_length (ldpw->io_buffer);
        if (offset)
  	{
  	  off_t off = lseek (in_fd, *offset, SEEK_SET);
  	  if (PREDICT_FALSE (off == -1))
  	    {
  	      size = -1;
  	      goto done;
  	    }
  
  	  ASSERT (off == *offset);
  	  *offset += results + 1;
  	}
        if (eagain)
  	{
  	  errno = EAGAIN;
  	  size = -1;
  	}
        else
  	size = results;
      }
    else
      {
        size = libc_sendfile (out_fd, in_fd, offset, len);
      }
  
  done:
    return size;
  }
  
  ssize_t
  sendfile64 (int out_fd, int in_fd, off_t * offset, size_t len)
  {
    return sendfile (out_fd, in_fd, offset, len);
  }
  
  ssize_t
  recv (int fd, void *buf, size_t n, int flags)
  {
    vls_handle_t vlsh;
    ssize_t size;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        size = vls_recvfrom (vlsh, buf, n, flags, NULL);
        if (size < 0)
  	{
  	  errno = -size;
  	  size = -1;
  	}
      }
    else
      {
        size = libc_recv (fd, buf, n, flags);
      }
  
    return size;
  }
  
  static int
  ldp_vls_sendo (vls_handle_t vlsh, const void *buf, size_t n, int flags,
  	       __CONST_SOCKADDR_ARG addr, socklen_t addr_len)
  {
    vppcom_endpt_t *ep = 0;
    vppcom_endpt_t _ep;
  
    if (addr)
      {
        ep = &_ep;
        switch (addr->sa_family)
  	{
  	case AF_INET:
  	  ep->is_ip4 = VPPCOM_IS_IP4;
  	  ep->ip =
  	    (uint8_t *) & ((const struct sockaddr_in *) addr)->sin_addr;
  	  ep->port = (uint16_t) ((const struct sockaddr_in *) addr)->sin_port;
  	  break;
  
  	case AF_INET6:
  	  ep->is_ip4 = VPPCOM_IS_IP6;
  	  ep->ip =
  	    (uint8_t *) & ((const struct sockaddr_in6 *) addr)->sin6_addr;
  	  ep->port =
  	    (uint16_t) ((const struct sockaddr_in6 *) addr)->sin6_port;
  	  break;
  
  	default:
  	  return EAFNOSUPPORT;
  	}
      }
  
    return vls_sendto (vlsh, (void *) buf, n, flags, ep);
  }
  
  static int
  ldp_vls_recvfrom (vls_handle_t vlsh, void *__restrict buf, size_t n,
  		  int flags, __SOCKADDR_ARG addr,
  		  socklen_t * __restrict addr_len)
  {
    u8 src_addr[sizeof (struct sockaddr_in6)];
    vppcom_endpt_t ep;
    ssize_t size;
    int rv;
  
    if (addr)
      {
        ep.ip = src_addr;
        size = vls_recvfrom (vlsh, buf, n, flags, &ep);
  
        if (size > 0)
  	{
  	  rv = ldp_copy_ep_to_sockaddr (addr, addr_len, &ep);
  	  if (rv < 0)
  	    size = rv;
  	}
      }
    else
      size = vls_recvfrom (vlsh, buf, n, flags, NULL);
  
    return size;
  }
  
  ssize_t
  sendto (int fd, const void *buf, size_t n, int flags,
  	__CONST_SOCKADDR_ARG addr, socklen_t addr_len)
  {
    vls_handle_t vlsh;
    ssize_t size;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != INVALID_SESSION_ID)
      {
        size = ldp_vls_sendo (vlsh, buf, n, flags, addr, addr_len);
        if (size < 0)
  	{
  	  errno = -size;
  	  size = -1;
  	}
      }
    else
      {
        size = libc_sendto (fd, buf, n, flags, addr, addr_len);
      }
  
    return size;
  }
  
  ssize_t
  recvfrom (int fd, void *__restrict buf, size_t n, int flags,
  	  __SOCKADDR_ARG addr, socklen_t * __restrict addr_len)
  {
    vls_handle_t vlsh;
    ssize_t size;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        size = ldp_vls_recvfrom (vlsh, buf, n, flags, addr, addr_len);
        if (size < 0)
  	{
  	  errno = -size;
  	  size = -1;
  	}
      }
    else
      {
        size = libc_recvfrom (fd, buf, n, flags, addr, addr_len);
      }
  
    return size;
  }
  
  ssize_t
  sendmsg (int fd, const struct msghdr * msg, int flags)
  {
    vls_handle_t vlsh;
    ssize_t size;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        struct iovec *iov = msg->msg_iov;
        ssize_t total = 0;
        int i, rv;
  
        for (i = 0; i < msg->msg_iovlen; ++i)
  	{
  	  rv = ldp_vls_sendo (vlsh, iov[i].iov_base, iov[i].iov_len, flags,
  			      msg->msg_name, msg->msg_namelen);
  	  if (rv < 0)
  	    break;
  	  else
  	    {
  	      total += rv;
  	      if (rv < iov[i].iov_len)
  		break;
  	    }
  	}
  
        if (rv < 0 && total == 0)
  	{
  	  errno = -rv;
  	  size = -1;
  	}
        else
  	size = total;
      }
    else
      {
        size = libc_sendmsg (fd, msg, flags);
      }
  
    return size;
  }
  
  #ifdef USE_GNU
  int
  sendmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags)
  {
    ssize_t size;
    const char *func_str;
    u32 sh = ldp_fd_to_vlsh (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sh != INVALID_SESSION_ID)
      {
        clib_warning ("LDP<%d>: LDP-TBD", getpid ());
        errno = ENOSYS;
        size = -1;
      }
    else
      {
        func_str = "libc_sendmmsg";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "vmessages %p, vlen %u, flags 0x%x",
  		      getpid (), fd, fd, func_str, vmessages, vlen, flags);
  
        size = libc_sendmmsg (fd, vmessages, vlen, flags);
      }
  
    if (LDP_DEBUG > 2)
      {
        if (size < 0)
  	{
  	  int errno_val = errno;
  	  perror (func_str);
  	  clib_warning ("LDP<%d>: ERROR: fd %d (0x%x): %s() failed! "
  			"rv %d, errno = %d", getpid (), fd, fd,
  			func_str, size, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: fd %d (0x%x): returning %d (0x%x)",
  		      getpid (), fd, fd, size, size);
      }
    return size;
  }
  #endif
  
  ssize_t
  recvmsg (int fd, struct msghdr * msg, int flags)
  {
    vls_handle_t vlsh;
    ssize_t size;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        struct iovec *iov = msg->msg_iov;
        ssize_t max_deq, total = 0;
        int i, rv;
  
        max_deq = vls_attr (vlsh, VPPCOM_ATTR_GET_NREAD, 0, 0);
        if (!max_deq)
  	return 0;
  
        for (i = 0; i < msg->msg_iovlen; i++)
  	{
  	  rv = ldp_vls_recvfrom (vlsh, iov[i].iov_base, iov[i].iov_len, flags,
  				 (i == 0 ? msg->msg_name : NULL),
  				 (i == 0 ? &msg->msg_namelen : NULL));
  	  if (rv <= 0)
  	    break;
  	  else
  	    {
  	      total += rv;
  	      if (rv < iov[i].iov_len)
  		break;
  	    }
  	  if (total >= max_deq)
  	    break;
  	}
  
        if (rv < 0 && total == 0)
  	{
  	  errno = -rv;
  	  size = -1;
  	}
        else
  	size = total;
      }
    else
      {
        size = libc_recvmsg (fd, msg, flags);
      }
  
    return size;
  }
  
  #ifdef USE_GNU
  int
  recvmmsg (int fd, struct mmsghdr *vmessages,
  	  unsigned int vlen, int flags, struct timespec *tmo)
  {
    ssize_t size;
    const char *func_str;
    u32 sh = ldp_fd_to_vlsh (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sh != INVALID_SESSION_ID)
      {
        clib_warning ("LDP<%d>: LDP-TBD", getpid ());
        errno = ENOSYS;
        size = -1;
      }
    else
      {
        func_str = "libc_recvmmsg";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "vmessages %p, vlen %u, flags 0x%x, tmo %p",
  		      getpid (), fd, fd, func_str, vmessages, vlen,
  		      flags, tmo);
  
        size = libc_recvmmsg (fd, vmessages, vlen, flags, tmo);
      }
  
    if (LDP_DEBUG > 2)
      {
        if (size < 0)
  	{
  	  int errno_val = errno;
  	  perror (func_str);
  	  clib_warning ("LDP<%d>: ERROR: fd %d (0x%x): %s() failed! "
  			"rv %d, errno = %d", getpid (), fd, fd,
  			func_str, size, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: fd %d (0x%x): returning %d (0x%x)",
  		      getpid (), fd, fd, size, size);
      }
    return size;
  }
  #endif
  
  int
  getsockopt (int fd, int level, int optname,
  	    void *__restrict optval, socklen_t * __restrict optlen)
  {
    vls_handle_t vlsh;
    int rv;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        rv = -EOPNOTSUPP;
  
        switch (level)
  	{
  	case SOL_TCP:
  	  switch (optname)
  	    {
  	    case TCP_NODELAY:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_GET_TCP_NODELAY,
  			     optval, optlen);
  	      break;
  	    case TCP_MAXSEG:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_GET_TCP_USER_MSS,
  			     optval, optlen);
  	      break;
  	    case TCP_KEEPIDLE:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_GET_TCP_KEEPIDLE,
  			     optval, optlen);
  	      break;
  	    case TCP_KEEPINTVL:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_GET_TCP_KEEPINTVL,
  			     optval, optlen);
  	      break;
  	    case TCP_INFO:
  	      if (optval && optlen && (*optlen == sizeof (struct tcp_info)))
  		{
  		  LDBG (1, "fd %d: vlsh %u SOL_TCP, TCP_INFO, optval %p, "
  			"optlen %d: #LDP-NOP#", fd, vlsh, optval, *optlen);
  		  memset (optval, 0, *optlen);
  		  rv = VPPCOM_OK;
  		}
  	      else
  		rv = -EFAULT;
  	      break;
  	    case TCP_CONGESTION:
  	      *optlen = strlen ("cubic");
  	      strncpy (optval, "cubic", *optlen + 1);
  	      rv = 0;
  	      break;
  	    default:
  	      LDBG (0, "ERROR: fd %d: getsockopt SOL_TCP: sid %u, "
  		    "optname %d unsupported!", fd, vlsh, optname);
  	      break;
  	    }
  	  break;
  	case SOL_IPV6:
  	  switch (optname)
  	    {
  	    case IPV6_V6ONLY:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_GET_V6ONLY, optval, optlen);
  	      break;
  	    default:
  	      LDBG (0, "ERROR: fd %d: getsockopt SOL_IPV6: vlsh %u "
  		    "optname %d unsupported!", fd, vlsh, optname);
  	      break;
  	    }
  	  break;
  	case SOL_SOCKET:
  	  switch (optname)
  	    {
  	    case SO_ACCEPTCONN:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_GET_LISTEN, optval, optlen);
  	      break;
  	    case SO_KEEPALIVE:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_GET_KEEPALIVE, optval, optlen);
  	      break;
  	    case SO_PROTOCOL:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_GET_PROTOCOL, optval, optlen);
  	      *(int *) optval = *(int *) optval ? SOCK_DGRAM : SOCK_STREAM;
  	      break;
  	    case SO_SNDBUF:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_GET_TX_FIFO_LEN,
  			     optval, optlen);
  	      break;
  	    case SO_RCVBUF:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_GET_RX_FIFO_LEN,
  			     optval, optlen);
  	      break;
  	    case SO_REUSEADDR:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_GET_REUSEADDR, optval, optlen);
  	      break;
  	    case SO_BROADCAST:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_GET_BROADCAST, optval, optlen);
  	      break;
  	    case SO_ERROR:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_GET_ERROR, optval, optlen);
  	      break;
  	    default:
  	      LDBG (0, "ERROR: fd %d: getsockopt SOL_SOCKET: vlsh %u "
  		    "optname %d unsupported!", fd, vlsh, optname);
  	      break;
  	    }
  	  break;
  	default:
  	  break;
  	}
  
        if (rv != VPPCOM_OK)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
        rv = libc_getsockopt (fd, level, optname, optval, optlen);
      }
  
    return rv;
  }
  
  int
  setsockopt (int fd, int level, int optname,
  	    const void *optval, socklen_t optlen)
  {
    vls_handle_t vlsh;
    int rv;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        rv = -EOPNOTSUPP;
  
        switch (level)
  	{
  	case SOL_TCP:
  	  switch (optname)
  	    {
  	    case TCP_NODELAY:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_SET_TCP_NODELAY,
  			     (void *) optval, &optlen);
  	      break;
  	    case TCP_MAXSEG:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_SET_TCP_USER_MSS,
  			     (void *) optval, &optlen);
  	      break;
  	    case TCP_KEEPIDLE:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_SET_TCP_KEEPIDLE,
  			     (void *) optval, &optlen);
  	      break;
  	    case TCP_KEEPINTVL:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_SET_TCP_KEEPINTVL,
  			     (void *) optval, &optlen);
  	      break;
  	    case TCP_CONGESTION:
  	    case TCP_CORK:
  	      /* Ignore */
  	      rv = 0;
  	      break;
  	    default:
  	      LDBG (0, "ERROR: fd %d: setsockopt() SOL_TCP: vlsh %u"
  		    "optname %d unsupported!", fd, vlsh, optname);
  	      break;
  	    }
  	  break;
  	case SOL_IPV6:
  	  switch (optname)
  	    {
  	    case IPV6_V6ONLY:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_SET_V6ONLY,
  			     (void *) optval, &optlen);
  	      break;
  	    default:
  	      LDBG (0, "ERROR: fd %d: setsockopt SOL_IPV6: vlsh %u"
  		    "optname %d unsupported!", fd, vlsh, optname);
  	      break;
  	    }
  	  break;
  	case SOL_SOCKET:
  	  switch (optname)
  	    {
  	    case SO_KEEPALIVE:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_SET_KEEPALIVE,
  			     (void *) optval, &optlen);
  	      break;
  	    case SO_REUSEADDR:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_SET_REUSEADDR,
  			     (void *) optval, &optlen);
  	      break;
  	    case SO_BROADCAST:
  	      rv = vls_attr (vlsh, VPPCOM_ATTR_SET_BROADCAST,
  			     (void *) optval, &optlen);
  	      break;
  	    default:
  	      LDBG (0, "ERROR: fd %d: setsockopt SOL_SOCKET: vlsh %u "
  		    "optname %d unsupported!", fd, vlsh, optname);
  	      break;
  	    }
  	  break;
  	default:
  	  break;
  	}
  
        if (rv != VPPCOM_OK)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
        rv = libc_setsockopt (fd, level, optname, optval, optlen);
      }
  
    return rv;
  }
  
  int
  listen (int fd, int n)
  {
    vls_handle_t vlsh;
    int rv;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        LDBG (0, "fd %d: calling vls_listen: vlsh %u, n %d", fd, vlsh, n);
  
        rv = vls_listen (vlsh, n);
        if (rv != VPPCOM_OK)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
        LDBG (0, "fd %d: calling libc_listen(): n %d", fd, n);
        rv = libc_listen (fd, n);
      }
  
    LDBG (1, "fd %d: returning %d", fd, rv);
    return rv;
  }
  
  static inline int
  ldp_accept4 (int listen_fd, __SOCKADDR_ARG addr,
  	     socklen_t * __restrict addr_len, int flags)
  {
    vls_handle_t listen_vlsh, accept_vlsh;
    int rv;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    listen_vlsh = ldp_fd_to_vlsh (listen_fd);
    if (listen_vlsh != VLS_INVALID_HANDLE)
      {
        vppcom_endpt_t ep;
        u8 src_addr[sizeof (struct sockaddr_in6)];
        memset (&ep, 0, sizeof (ep));
        ep.ip = src_addr;
  
        LDBG (0, "listen fd %d: calling vppcom_session_accept: listen sid %u,"
  	    " ep %p, flags 0x%x", listen_fd, listen_vlsh, ep, flags);
  
        accept_vlsh = vls_accept (listen_vlsh, &ep, flags);
        if (accept_vlsh < 0)
  	{
  	  errno = -accept_vlsh;
  	  rv = -1;
  	}
        else
  	{
  	  rv = ldp_copy_ep_to_sockaddr (addr, addr_len, &ep);
  	  if (rv != VPPCOM_OK)
  	    {
  	      (void) vls_close (accept_vlsh);
  	      errno = -rv;
  	      rv = -1;
  	    }
  	  else
  	    {
  	      rv = ldp_vlsh_to_fd (accept_vlsh);
  	    }
  	}
      }
    else
      {
        LDBG (0, "listen fd %d: calling libc_accept4(): addr %p, addr_len %p,"
  	    " flags 0x%x", listen_fd, addr, addr_len, flags);
  
        rv = libc_accept4 (listen_fd, addr, addr_len, flags);
      }
  
    LDBG (1, "listen fd %d: accept returning %d", listen_fd, rv);
  
    return rv;
  }
  
  int
  accept4 (int fd, __SOCKADDR_ARG addr, socklen_t * __restrict addr_len,
  	 int flags)
  {
    return ldp_accept4 (fd, addr, addr_len, flags);
  }
  
  int
  accept (int fd, __SOCKADDR_ARG addr, socklen_t * __restrict addr_len)
  {
    return ldp_accept4 (fd, addr, addr_len, 0);
  }
  
  int
  shutdown (int fd, int how)
  {
    vls_handle_t vlsh;
    int rv = 0, flags;
    u32 flags_len = sizeof (flags);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vlsh = ldp_fd_to_vlsh (fd);
    if (vlsh != VLS_INVALID_HANDLE)
      {
        LDBG (0, "called shutdown: fd %u vlsh %u how %d", fd, vlsh, how);
  
        if (vls_attr (vlsh, VPPCOM_ATTR_SET_SHUT, &how, &flags_len))
  	{
  	  close (fd);
  	  return -1;
  	}
  
        if (vls_attr (vlsh, VPPCOM_ATTR_GET_SHUT, &flags, &flags_len))
  	{
  	  close (fd);
  	  return -1;
  	}
  
        if (flags == SHUT_RDWR)
  	rv = close (fd);
      }
    else
      {
        LDBG (0, "fd %d: calling libc_shutdown: how %d", fd, how);
        rv = libc_shutdown (fd, how);
      }
  
    return rv;
  }
  
  int
  epoll_create1 (int flags)
  {
    ldp_worker_ctx_t *ldpw = ldp_worker_get_current ();
    vls_handle_t vlsh;
    int rv;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (ldp->vcl_needs_real_epoll)
      {
        /* Make sure workers have been allocated */
        if (!ldp->workers)
  	{
  	  ldp_alloc_workers ();
  	  ldpw = ldp_worker_get_current ();
  	}
        rv = libc_epoll_create1 (flags);
        ldp->vcl_needs_real_epoll = 0;
        ldpw->vcl_mq_epfd = rv;
        LDBG (0, "created vcl epfd %u", rv);
        return rv;
      }
  
    vlsh = vls_epoll_create ();
    if (PREDICT_FALSE (vlsh == VLS_INVALID_HANDLE))
      {
        errno = -vlsh;
        rv = -1;
      }
    else
      {
        rv = ldp_vlsh_to_fd (vlsh);
      }
    LDBG (0, "epoll_create epfd %u vlsh %u", rv, vlsh);
    return rv;
  }
  
  int
  epoll_create (int size)
  {
    return epoll_create1 (0);
  }
  
  int
  epoll_ctl (int epfd, int op, int fd, struct epoll_event *event)
  {
    vls_handle_t vep_vlsh, vlsh;
    int rv;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    vep_vlsh = ldp_fd_to_vlsh (epfd);
    if (PREDICT_FALSE (vep_vlsh == VLS_INVALID_HANDLE))
      {
        /* The LDP epoll_create1 always creates VCL epfd's.
         * The app should never have a kernel base epoll fd unless it
         * was acquired outside of the LD_PRELOAD process context.
         * In any case, if we get one, punt it to libc_epoll_ctl.
         */
        LDBG (1, "epfd %d: calling libc_epoll_ctl: op %d, fd %d"
  	    " event %p", epfd, op, fd, event);
  
        rv = libc_epoll_ctl (epfd, op, fd, event);
        goto done;
      }
  
    vlsh = ldp_fd_to_vlsh (fd);
  
    LDBG (0, "epfd %d ep_vlsh %d, fd %u vlsh %d, op %u", epfd, vep_vlsh, fd,
  	vlsh, op);
  
    if (vlsh != VLS_INVALID_HANDLE)
      {
        LDBG (1, "epfd %d: calling vls_epoll_ctl: ep_vlsh %d op %d, vlsh %u,"
  	    " event %p", epfd, vep_vlsh, vlsh, event);
  
        rv = vls_epoll_ctl (vep_vlsh, op, vlsh, event);
        if (rv != VPPCOM_OK)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
        int libc_epfd;
        u32 size = sizeof (epfd);
  
        libc_epfd = vls_attr (vep_vlsh, VPPCOM_ATTR_GET_LIBC_EPFD, 0, 0);
        if (!libc_epfd)
  	{
  	  LDBG (1, "epfd %d, vep_vlsh %d calling libc_epoll_create1: "
  		"EPOLL_CLOEXEC", epfd, vep_vlsh);
  
  	  libc_epfd = libc_epoll_create1 (EPOLL_CLOEXEC);
  	  if (libc_epfd < 0)
  	    {
  	      rv = libc_epfd;
  	      goto done;
  	    }
  
  	  rv = vls_attr (vep_vlsh, VPPCOM_ATTR_SET_LIBC_EPFD, &libc_epfd,
  			 &size);
  	  if (rv < 0)
  	    {
  	      errno = -rv;
  	      rv = -1;
  	      goto done;
  	    }
  	}
        else if (PREDICT_FALSE (libc_epfd < 0))
  	{
  	  errno = -epfd;
  	  rv = -1;
  	  goto done;
  	}
  
        LDBG (1, "epfd %d: calling libc_epoll_ctl: libc_epfd %d, op %d, fd %d,"
  	    " event %p", epfd, libc_epfd, op, fd, event);
  
        rv = libc_epoll_ctl (libc_epfd, op, fd, event);
      }
  
  done:
    return rv;
  }
  
  static inline int
  ldp_epoll_pwait (int epfd, struct epoll_event *events, int maxevents,
  		 int timeout, const sigset_t * sigmask)
  {
    ldp_worker_ctx_t *ldpw = ldp_worker_get_current ();
    double time_to_wait = (double) 0, max_time;
    int libc_epfd, rv = 0;
    vls_handle_t ep_vlsh;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (PREDICT_FALSE (!events || (timeout < -1)))
      {
        errno = EFAULT;
        return -1;
      }
  
    if (epfd == ldpw->vcl_mq_epfd)
      return libc_epoll_pwait (epfd, events, maxevents, timeout, sigmask);
  
    ep_vlsh = ldp_fd_to_vlsh (epfd);
    if (PREDICT_FALSE (ep_vlsh == VLS_INVALID_HANDLE))
      {
        LDBG (0, "epfd %d: bad ep_vlsh %d!", epfd, ep_vlsh);
        errno = EBADFD;
        return -1;
      }
  
    if (PREDICT_FALSE (ldpw->clib_time.init_cpu_time == 0))
      clib_time_init (&ldpw->clib_time);
    time_to_wait = ((timeout >= 0) ? (double) timeout / 1000 : 0);
    max_time = clib_time_now (&ldpw->clib_time) + time_to_wait;
  
    libc_epfd = vls_attr (ep_vlsh, VPPCOM_ATTR_GET_LIBC_EPFD, 0, 0);
    if (PREDICT_FALSE (libc_epfd < 0))
      {
        errno = -libc_epfd;
        rv = -1;
        goto done;
      }
  
    LDBG (2, "epfd %d: vep_idx %d, libc_epfd %d, events %p, maxevents %d, "
  	"timeout %d, sigmask %p: time_to_wait %.02f", epfd, ep_vlsh,
  	libc_epfd, events, maxevents, timeout, sigmask, time_to_wait);
    do
      {
        if (!ldpw->epoll_wait_vcl)
  	{
  	  rv = vls_epoll_wait (ep_vlsh, events, maxevents, 0);
  	  if (rv > 0)
  	    {
  	      ldpw->epoll_wait_vcl = 1;
  	      goto done;
  	    }
  	  else if (rv < 0)
  	    {
  	      errno = -rv;
  	      rv = -1;
  	      goto done;
  	    }
  	}
        else
  	ldpw->epoll_wait_vcl = 0;
  
        if (libc_epfd > 0)
  	{
  	  rv = libc_epoll_pwait (libc_epfd, events, maxevents, 0, sigmask);
  	  if (rv != 0)
  	    goto done;
  	}
      }
    while ((timeout == -1) || (clib_time_now (&ldpw->clib_time) < max_time));
  
  done:
    return rv;
  }
  
  static inline int
  ldp_epoll_pwait_eventfd (int epfd, struct epoll_event *events,
  			 int maxevents, int timeout, const sigset_t * sigmask)
  {
    ldp_worker_ctx_t *ldpw = ldp_worker_get_current ();
    int libc_epfd, rv = 0, num_ev;
    vls_handle_t ep_vlsh;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (PREDICT_FALSE (!events || (timeout < -1)))
      {
        errno = EFAULT;
        return -1;
      }
  
    if (epfd == ldpw->vcl_mq_epfd)
      return libc_epoll_pwait (epfd, events, maxevents, timeout, sigmask);
  
    ep_vlsh = ldp_fd_to_vlsh (epfd);
    if (PREDICT_FALSE (ep_vlsh == VLS_INVALID_HANDLE))
      {
        LDBG (0, "epfd %d: bad ep_vlsh %d!", epfd, ep_vlsh);
        errno = EBADFD;
        return -1;
      }
  
    libc_epfd = vls_attr (ep_vlsh, VPPCOM_ATTR_GET_LIBC_EPFD, 0, 0);
    if (PREDICT_FALSE (!libc_epfd))
      {
        u32 size = sizeof (epfd);
  
        LDBG (1, "epfd %d, vep_vlsh %d calling libc_epoll_create1: "
  	    "EPOLL_CLOEXEC", epfd, ep_vlsh);
        libc_epfd = libc_epoll_create1 (EPOLL_CLOEXEC);
        if (libc_epfd < 0)
  	{
  	  rv = libc_epfd;
  	  goto done;
  	}
  
        rv = vls_attr (ep_vlsh, VPPCOM_ATTR_SET_LIBC_EPFD, &libc_epfd, &size);
        if (rv < 0)
  	{
  	  errno = -rv;
  	  rv = -1;
  	  goto done;
  	}
      }
    if (PREDICT_FALSE (libc_epfd <= 0))
      {
        errno = -libc_epfd;
        rv = -1;
        goto done;
      }
  
    if (PREDICT_FALSE (!ldpw->mq_epfd_added))
      {
        struct epoll_event e = { 0 };
        e.events = EPOLLIN;
        e.data.fd = ldpw->vcl_mq_epfd;
        if (libc_epoll_ctl (libc_epfd, EPOLL_CTL_ADD, ldpw->vcl_mq_epfd, &e) <
  	  0)
  	{
  	  LDBG (0, "epfd %d, add libc mq epoll fd %d to libc epoll fd %d",
  		epfd, ldpw->vcl_mq_epfd, libc_epfd);
  	  rv = -1;
  	  goto done;
  	}
        ldpw->mq_epfd_added = 1;
      }
  
    rv = vls_epoll_wait (ep_vlsh, events, maxevents, 0);
    if (rv > 0)
      goto done;
    else if (rv < 0)
      {
        errno = -rv;
        rv = -1;
        goto done;
      }
  
    rv = libc_epoll_pwait (libc_epfd, events, maxevents, timeout, sigmask);
    if (rv <= 0)
      goto done;
    for (int i = 0; i < rv; i++)
      {
        if (events[i].data.fd == ldpw->vcl_mq_epfd)
  	{
  	  /* We should remove mq epoll fd from events. */
  	  rv--;
  	  if (i != rv)
  	    {
  	      events[i].events = events[rv].events;
  	      events[i].data.u64 = events[rv].data.u64;
  	    }
  	  num_ev = vls_epoll_wait (ep_vlsh, &events[rv], maxevents - rv, 0);
  	  if (PREDICT_TRUE (num_ev > 0))
  	    rv += num_ev;
  	  break;
  	}
      }
  
  done:
    return rv;
  }
  
  int
  epoll_pwait (int epfd, struct epoll_event *events,
  	     int maxevents, int timeout, const sigset_t * sigmask)
  {
    if (vls_use_eventfd ())
      return ldp_epoll_pwait_eventfd (epfd, events, maxevents, timeout,
  				    sigmask);
    else
      return ldp_epoll_pwait (epfd, events, maxevents, timeout, sigmask);
  }
  
  int
  epoll_wait (int epfd, struct epoll_event *events, int maxevents, int timeout)
  {
    if (vls_use_eventfd ())
      return ldp_epoll_pwait_eventfd (epfd, events, maxevents, timeout, NULL);
    else
      return ldp_epoll_pwait (epfd, events, maxevents, timeout, NULL);
  }
  
  int
  poll (struct pollfd *fds, nfds_t nfds, int timeout)
  {
    ldp_worker_ctx_t *ldpw = ldp_worker_get_current ();
    int rv, i, n_revents = 0;
    vls_handle_t vlsh;
    vcl_poll_t *vp;
    double max_time;
  
    LDBG (3, "fds %p, nfds %d, timeout %d", fds, nfds, timeout);
  
    if (PREDICT_FALSE (ldpw->clib_time.init_cpu_time == 0))
      clib_time_init (&ldpw->clib_time);
  
    max_time = (timeout >= 0) ? (f64) timeout / 1000 : 0;
    max_time += clib_time_now (&ldpw->clib_time);
  
    for (i = 0; i < nfds; i++)
      {
        if (fds[i].fd < 0)
  	continue;
  
        vlsh = ldp_fd_to_vlsh (fds[i].fd);
        if (vlsh != VLS_INVALID_HANDLE)
  	{
  	  fds[i].fd = -fds[i].fd;
  	  vec_add2 (ldpw->vcl_poll, vp, 1);
  	  vp->fds_ndx = i;
  	  vp->sh = vlsh_to_sh (vlsh);
  	  vp->events = fds[i].events;
  #ifdef __USE_XOPEN2K
  	  if (fds[i].events & POLLRDNORM)
  	    vp->events |= POLLIN;
  	  if (fds[i].events & POLLWRNORM)
  	    vp->events |= POLLOUT;
  #endif
  	  vp->revents = fds[i].revents;
  	}
        else
  	{
  	  vec_add1 (ldpw->libc_poll, fds[i]);
  	  vec_add1 (ldpw->libc_poll_idxs, i);
  	}
      }
  
    do
      {
        if (vec_len (ldpw->vcl_poll))
  	{
  	  rv = vppcom_poll (ldpw->vcl_poll, vec_len (ldpw->vcl_poll), 0);
  	  if (rv < 0)
  	    {
  	      errno = -rv;
  	      rv = -1;
  	      goto done;
  	    }
  	  else
  	    n_revents += rv;
  	}
  
        if (vec_len (ldpw->libc_poll))
  	{
  	  rv = libc_poll (ldpw->libc_poll, vec_len (ldpw->libc_poll), 0);
  	  if (rv < 0)
  	    goto done;
  	  else
  	    n_revents += rv;
  	}
  
        if (n_revents)
  	{
  	  rv = n_revents;
  	  goto done;
  	}
      }
    while ((timeout < 0) || (clib_time_now (&ldpw->clib_time) < max_time));
    rv = 0;
  
  done:
    vec_foreach (vp, ldpw->vcl_poll)
    {
      fds[vp->fds_ndx].fd = -fds[vp->fds_ndx].fd;
      fds[vp->fds_ndx].revents = vp->revents;
  #ifdef __USE_XOPEN2K
      if ((fds[vp->fds_ndx].revents & POLLIN) &&
  	(fds[vp->fds_ndx].events & POLLRDNORM))
        fds[vp->fds_ndx].revents |= POLLRDNORM;
      if ((fds[vp->fds_ndx].revents & POLLOUT) &&
  	(fds[vp->fds_ndx].events & POLLWRNORM))
        fds[vp->fds_ndx].revents |= POLLWRNORM;
  #endif
    }
    vec_reset_length (ldpw->vcl_poll);
  
    for (i = 0; i < vec_len (ldpw->libc_poll); i++)
      {
        fds[ldpw->libc_poll_idxs[i]].revents = ldpw->libc_poll[i].revents;
      }
    vec_reset_length (ldpw->libc_poll_idxs);
    vec_reset_length (ldpw->libc_poll);
  
    return rv;
  }
  
  #ifdef USE_GNU
  int
  ppoll (struct pollfd *fds, nfds_t nfds,
         const struct timespec *timeout, const sigset_t * sigmask)
  {
    if ((errno = -ldp_init ()))
      return -1;
  
    clib_warning ("LDP<%d>: LDP-TBD", getpid ());
    errno = ENOSYS;
  
  
    return -1;
  }
  #endif
  
  void CONSTRUCTOR_ATTRIBUTE ldp_constructor (void);
  
  void DESTRUCTOR_ATTRIBUTE ldp_destructor (void);
  
  /*
   * This function is called when the library is loaded
   */
  void
  ldp_constructor (void)
  {
    swrap_constructor ();
    if (ldp_init () != 0)
      {
        fprintf (stderr, "\nLDP<%d>: ERROR: ldp_constructor: failed!\n",
  	       getpid ());
        _exit (1);
      }
    else if (LDP_DEBUG > 0)
      clib_warning ("LDP<%d>: LDP constructor: done!\n", getpid ());
  }
  
  /*
   * This function is called when the library is unloaded
   */
  void
  ldp_destructor (void)
  {
    /*
       swrap_destructor ();
       if (ldp->init)
       ldp->init = 0;
     */
  
    /* Don't use clib_warning() here because that calls writev()
     * which will call ldp_init().
     */
    if (LDP_DEBUG > 0)
      fprintf (stderr, "%s:%d: LDP<%d>: LDP destructor: done!\n",
  	     __func__, __LINE__, getpid ());
  }
  
  
  /*
   * fd.io coding-style-patch-verification: ON
   *
   * Local Variables:
   * eval: (c-set-style "gnu")
   * End:
   */
  