text: /*
   * Copyright (c) 2016 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/vppcom.h>
  #include <vppinfra/time.h>
  #include <vppinfra/bitmap.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
  
  typedef struct
  {
    int init;
    char app_name[LDP_APP_NAME_MAX];
    u32 sid_bit_val;
    u32 sid_bit_mask;
    u32 debug;
    u8 *io_buffer;
    clib_time_t clib_time;
    clib_bitmap_t *rd_bitmap;
    clib_bitmap_t *wr_bitmap;
    clib_bitmap_t *ex_bitmap;
    clib_bitmap_t *sid_rd_bitmap;
    clib_bitmap_t *sid_wr_bitmap;
    clib_bitmap_t *sid_ex_bitmap;
    clib_bitmap_t *libc_rd_bitmap;
    clib_bitmap_t *libc_wr_bitmap;
    clib_bitmap_t *libc_ex_bitmap;
    vcl_poll_t *vcl_poll;
    u8 select_vcl;
    u8 epoll_wait_vcl;
    u8 vcl_needs_real_epoll;	/*< vcl needs next epoll_create to
  				   go to libc_epoll */
    int vcl_mq_epfd;
  
  } ldp_main_t;
  #define LDP_DEBUG ldp->debug
  
  #define LDBG(_lvl, _fmt, _args...) 					\
    if (ldp->debug > _lvl)						\
      clib_warning (_fmt, ##_args)
  
  static ldp_main_t ldp_main = {
    .sid_bit_val = (1 << LDP_SID_BIT_MIN),
    .sid_bit_mask = (1 << LDP_SID_BIT_MIN) - 1,
    .debug = LDP_DEBUG_INIT,
  };
  
  static ldp_main_t *ldp = &ldp_main;
  
  /*
   * RETURN:  0 on success or -1 on error.
   * */
  static inline void
  ldp_set_app_name (char *app_name)
  {
    int rv = snprintf (ldp->app_name, LDP_APP_NAME_MAX,
  		     "ldp-%d-%s", getpid (), app_name);
  
    if (rv >= LDP_APP_NAME_MAX)
      app_name[LDP_APP_NAME_MAX - 1] = 0;
  }
  
  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_fd_from_sid (u32 sid)
  {
    if (PREDICT_FALSE (sid >= ldp->sid_bit_val))
      return -EMFILE;
    else
      return (sid | ldp->sid_bit_val);
  }
  
  static inline int
  ldp_fd_is_sid (int fd)
  {
    return ((u32) fd & ldp->sid_bit_val) ? 1 : 0;
  }
  
  static inline u32
  ldp_sid_from_fd (int fd)
  {
    return (ldp_fd_is_sid (fd) ? ((u32) fd & ldp->sid_bit_mask) :
  	  INVALID_SESSION_ID);
  }
  
  static inline int
  ldp_init (void)
  {
    int rv;
  
    if (PREDICT_TRUE (ldp->init))
      return 0;
  
    ldp->init = 1;
    ldp->vcl_needs_real_epoll = 1;
    rv = vppcom_app_create (ldp_get_app_name ());
    if (rv != VPPCOM_OK)
      {
        fprintf (stderr, "\nLDP<%d>: ERROR: ldp_init: vppcom_app_create()"
  	       " failed!  rv = %d (%s)\n",
  	       getpid (), rv, vppcom_retval_str (rv));
        ldp->init = 0;
        return rv;
      }
    ldp->vcl_needs_real_epoll = 0;
  
    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, "LDP<%d>: configured LDP debug level (%u) from env var "
  		LDP_ENV_DEBUG "!", getpid (), ldp->debug);
  	}
      }
  
    env_var_str = getenv (LDP_ENV_APP_NAME);
    if (env_var_str)
      {
        ldp_set_app_name (env_var_str);
        LDBG (0, "LDP<%d>: configured LDP app name (%s) from the env var "
  	    LDP_ENV_APP_NAME "!", getpid (), 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)
  	{
  	  clib_warning ("LDP<%d>: WARNING: Invalid LDP sid bit specified in"
  			" the env var " LDP_ENV_SID_BIT " (%s)! sid bit "
  			"value %d (0x%x)", getpid (), env_var_str,
  			ldp->sid_bit_val, ldp->sid_bit_val);
  	}
        else if (sb < LDP_SID_BIT_MIN)
  	{
  	  ldp->sid_bit_val = (1 << LDP_SID_BIT_MIN);
  	  ldp->sid_bit_mask = ldp->sid_bit_val - 1;
  
  	  clib_warning ("LDP<%d>: 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)",
  			getpid (), sb, env_var_str, LDP_SID_BIT_MIN,
  			ldp->sid_bit_val, ldp->sid_bit_val);
  	}
        else if (sb > LDP_SID_BIT_MAX)
  	{
  	  ldp->sid_bit_val = (1 << LDP_SID_BIT_MAX);
  	  ldp->sid_bit_mask = ldp->sid_bit_val - 1;
  
  	  clib_warning ("LDP<%d>: 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)",
  			getpid (), sb, env_var_str, LDP_SID_BIT_MAX,
  			ldp->sid_bit_val, ldp->sid_bit_val);
  	}
        else
  	{
  	  ldp->sid_bit_val = (1 << sb);
  	  ldp->sid_bit_mask = ldp->sid_bit_val - 1;
  
  	  LDBG (0, "LDP<%d>: configured LDP sid bit (%u) from "
  		LDP_ENV_SID_BIT "!  sid bit value %d (0x%x)", getpid (), sb,
  		ldp->sid_bit_val, ldp->sid_bit_val);
  	}
      }
  
    clib_time_init (&ldp->clib_time);
    LDBG (0, "LDP<%d>: LDP initialization: done!", getpid ());
  
    return 0;
  }
  
  int
  close (int fd)
  {
    int rv;
    const char *func_str;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        int epfd;
  
        func_str = "vppcom_session_attr[GET_LIBC_EPFD]";
        epfd = vppcom_session_attr (sid, VPPCOM_ATTR_GET_LIBC_EPFD, 0, 0);
        if (epfd > 0)
  	{
  	  func_str = "libc_close";
  
  	  if (LDP_DEBUG > 0)
  	    clib_warning
  	      ("LDP<%d>: fd %d (0x%x): calling %s(): epfd %u (0x%x)",
  	       getpid (), fd, fd, func_str, epfd, epfd);
  
  	  rv = libc_close (epfd);
  	  if (rv < 0)
  	    {
  	      u32 size = sizeof (epfd);
  	      epfd = 0;
  
  	      (void) vppcom_session_attr (sid, VPPCOM_ATTR_SET_LIBC_EPFD,
  					  &epfd, &size);
  	    }
  	}
        else if (PREDICT_FALSE (epfd < 0))
  	{
  	  errno = -epfd;
  	  rv = -1;
  	  goto done;
  	}
  
        func_str = "vppcom_session_close";
  
        if (LDP_DEBUG > 0)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): sid %u (0x%x)",
  		      getpid (), fd, fd, func_str, sid, sid);
  
        rv = vppcom_session_close (sid);
        if (rv != VPPCOM_OK)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
        func_str = "libc_close";
  
        if (LDP_DEBUG > 0)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s()",
  		      getpid (), fd, fd, func_str);
  
        rv = libc_close (fd);
      }
  
  done:
    if (LDP_DEBUG > 0)
      {
        if (rv < 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, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: fd %d (0x%x): returning %d (0x%x)",
  		      getpid (), fd, fd, rv, rv);
      }
    return rv;
  }
  
  ssize_t
  read (int fd, void *buf, size_t nbytes)
  {
    ssize_t size;
    const char *func_str;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        func_str = "vppcom_session_read";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "sid %u (0x%x), buf %p, nbytes %u", getpid (),
  		      fd, fd, func_str, sid, sid, buf, nbytes);
  
        size = vppcom_session_read (sid, buf, nbytes);
        if (size < 0)
  	{
  	  errno = -size;
  	  size = -1;
  	}
      }
    else
      {
        func_str = "libc_read";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "buf %p, nbytes %u", getpid (),
  		      fd, fd, func_str, buf, nbytes);
  
        size = libc_read (fd, buf, nbytes);
      }
  
    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;
  }
  
  ssize_t
  readv (int fd, const struct iovec * iov, int iovcnt)
  {
    const char *func_str;
    ssize_t size = 0;
    u32 sid = ldp_sid_from_fd (fd);
    int rv = 0, i, total = 0;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        func_str = "vppcom_session_read";
        do
  	{
  	  for (i = 0; i < iovcnt; ++i)
  	    {
  	      if (LDP_DEBUG > 2)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s() [%d]: "
  			      "sid %u (0x%x), iov %p, iovcnt %d, total %d",
  			      getpid (), fd, fd, func_str, i, sid, sid,
  			      iov, iovcnt, total);
  
  	      rv = vppcom_session_read (sid, iov[i].iov_base, iov[i].iov_len);
  	      if (rv < 0)
  		break;
  	      else
  		{
  		  total += rv;
  		  if (rv < iov[i].iov_len)
  		    {
  		      if (LDP_DEBUG > 2)
  			clib_warning ("LDP<%d>: fd %d (0x%x): "
  				      "rv (%d) < iov[%d].iov_len (%d)",
  				      getpid (), fd, fd, rv, i,
  				      iov[i].iov_len);
  		      break;
  		    }
  		}
  	    }
  	}
        while ((rv >= 0) && (total == 0));
  
        if (rv < 0)
  	{
  	  errno = -rv;
  	  size = -1;
  	}
        else
  	size = total;
      }
    else
      {
        func_str = "libc_readv";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "iov %p, iovcnt %d", getpid (), fd, fd, iov, iovcnt);
  
        size = libc_readv (fd, iov, iovcnt);
      }
  
    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;
  }
  
  ssize_t
  write (int fd, const void *buf, size_t nbytes)
  {
    const char *func_str;
    ssize_t size = 0;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        func_str = "vppcom_session_write";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "sid %u (0x%x), buf %p, nbytes %u", getpid (),
  		      fd, fd, func_str, sid, sid, buf, nbytes);
  
        size = vppcom_session_write (sid, (void *) buf, nbytes);
        if (size < 0)
  	{
  	  errno = -size;
  	  size = -1;
  	}
      }
    else
      {
        func_str = "libc_write";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "buf %p, nbytes %u", getpid (),
  		      fd, fd, func_str, buf, nbytes);
  
        size = libc_write (fd, buf, nbytes);
      }
  
    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;
  }
  
  ssize_t
  writev (int fd, const struct iovec * iov, int iovcnt)
  {
    const char *func_str;
    ssize_t size = 0, total = 0;
    u32 sid = ldp_sid_from_fd (fd);
    int i, rv = 0;
  
    /*
     * Use [f]printf() instead of clib_warning() to prevent recursion SIGSEGV.
     */
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        func_str = "vppcom_session_write";
        do
  	{
  	  for (i = 0; i < iovcnt; ++i)
  	    {
  	      if (LDP_DEBUG > 4)
  		printf ("%s:%d: LDP<%d>: fd %d (0x%x): calling %s() [%d]: "
  			"sid %u (0x%x), buf %p, nbytes %ld, total %ld",
  			__func__, __LINE__, getpid (), fd, fd, func_str,
  			i, sid, sid, iov[i].iov_base, iov[i].iov_len, total);
  
  	      rv = vppcom_session_write (sid, iov[i].iov_base,
  					 iov[i].iov_len);
  	      if (rv < 0)
  		break;
  	      else
  		{
  		  total += rv;
  		  if (rv < iov[i].iov_len)
  		    {
  		      if (LDP_DEBUG > 4)
  			printf ("%s:%d: LDP<%d>: fd %d (0x%x): "
  				"rv (%d) < iov[%d].iov_len (%ld)",
  				__func__, __LINE__, getpid (), fd, fd,
  				rv, i, iov[i].iov_len);
  		      break;
  		    }
  		}
  	    }
  	}
        while ((rv >= 0) && (total == 0));
  
        if (rv < 0)
  	{
  	  errno = -rv;
  	  size = -1;
  	}
        else
  	size = total;
      }
    else
      {
        func_str = "libc_writev";
  
        if (LDP_DEBUG > 4)
  	printf ("%s:%d: LDP<%d>: fd %d (0x%x): calling %s(): "
  		"iov %p, iovcnt %d\n", __func__, __LINE__, getpid (),
  		fd, fd, func_str, iov, iovcnt);
  
        size = libc_writev (fd, iov, iovcnt);
      }
  
    if (LDP_DEBUG > 4)
      {
        if (size < 0)
  	{
  	  int errno_val = errno;
  	  perror (func_str);
  	  fprintf (stderr,
  		   "%s:%d: LDP<%d>: ERROR: fd %d (0x%x): %s() failed! "
  		   "rv %ld, errno = %d\n", __func__, __LINE__, getpid (), fd,
  		   fd, func_str, size, errno_val);
  	  errno = errno_val;
  	}
        else
  	printf ("%s:%d: LDP<%d>: fd %d (0x%x): returning %ld\n",
  		__func__, __LINE__, getpid (), fd, fd, size);
      }
    return size;
  }
  
  int
  fcntl (int fd, int cmd, ...)
  {
    const char *func_str = __func__;
    int rv = 0;
    va_list ap;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    va_start (ap, cmd);
    if (sid != INVALID_SESSION_ID)
      {
        int flags = va_arg (ap, int);
        u32 size;
  
        size = sizeof (flags);
        rv = -EOPNOTSUPP;
        switch (cmd)
  	{
  	case F_SETFL:
  	  func_str = "vppcom_session_attr[SET_FLAGS]";
  	  if (LDP_DEBUG > 2)
  	    clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			  "sid %u (0x%x) flags %d (0x%x), size %d",
  			  getpid (), fd, fd, func_str, sid, sid,
  			  flags, flags, size);
  
  	  rv =
  	    vppcom_session_attr (sid, VPPCOM_ATTR_SET_FLAGS, &flags, &size);
  	  break;
  
  	case F_GETFL:
  	  func_str = "vppcom_session_attr[GET_FLAGS]";
  	  if (LDP_DEBUG > 2)
  	    clib_warning
  	      ("LDP<%d>: fd %d (0x%x): calling %s(): sid %u (0x%x), "
  	       "flags %d (0x%x), size %d", getpid (), fd, fd, func_str, sid,
  	       sid, flags, flags, size);
  
  	  rv =
  	    vppcom_session_attr (sid, VPPCOM_ATTR_GET_FLAGS, &flags, &size);
  	  if (rv == VPPCOM_OK)
  	    {
  	      if (LDP_DEBUG > 2)
  		clib_warning ("LDP<%d>: fd %d (0x%x), cmd %d (F_GETFL): "
  			      "%s() returned flags %d (0x%x)",
  			      getpid (), fd, fd, cmd, func_str, flags, flags);
  	      rv = flags;
  	    }
  	  break;
  
  	default:
  	  rv = -EOPNOTSUPP;
  	  break;
  	}
        if (rv < 0)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
        func_str = "libc_vfcntl";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): cmd %d",
  		      getpid (), fd, fd, func_str, cmd);
  
        rv = libc_vfcntl (fd, cmd, ap);
      }
  
    va_end (ap);
  
    if (LDP_DEBUG > 2)
      {
        if (rv < 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, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: fd %d (0x%x): returning %d (0x%x)",
  		      getpid (), fd, fd, rv, rv);
      }
    return rv;
  }
  
  int
  ioctl (int fd, unsigned long int cmd, ...)
  {
    const char *func_str;
    int rv;
    va_list ap;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    va_start (ap, cmd);
    if (sid != INVALID_SESSION_ID)
      {
        func_str = "vppcom_session_attr[GET_NREAD]";
  
        switch (cmd)
  	{
  	case FIONREAD:
  	  if (LDP_DEBUG > 2)
  	    clib_warning
  	      ("LDP<%d>: fd %d (0x%x): calling  %s(): sid %u (0x%x)",
  	       getpid (), fd, fd, func_str, sid, sid);
  
  	  rv = vppcom_session_attr (sid, 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.
  	     */
  	    if (LDP_DEBUG > 2)
  	      clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			    "sid %u (0x%x), flags %d (0x%x), size %d",
  			    getpid (), fd, fd, func_str, sid, sid,
  			    flags, flags, size);
  
  	    rv = vppcom_session_attr (sid, VPPCOM_ATTR_SET_FLAGS, &flags,
  				      &size);
  	  }
  	  break;
  
  	default:
  	  rv = -EOPNOTSUPP;
  	  break;
  	}
        if (rv < 0)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
        func_str = "libc_vioctl";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): cmd %d",
  		      getpid (), fd, fd, func_str, cmd);
  
        rv = libc_vioctl (fd, cmd, ap);
      }
  
    if (LDP_DEBUG > 2)
      {
        if (rv < 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, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: fd %d (0x%x): returning %d (0x%x)",
  		      getpid (), fd, fd, rv, rv);
      }
    va_end (ap);
    return rv;
  }
  
  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)
  {
    int rv;
    char *func_str = "##";
    f64 time_out;
    int fd;
    uword sid_bits, sid_bits_set, libc_bits, libc_bits_set;
    u32 minbits = clib_max (nfds, BITS (uword));
    u32 sid;
  
    if (nfds < 0)
      {
        errno = EINVAL;
        return -1;
      }
  
    if (timeout)
      {
        time_out = (timeout->tv_sec == 0 && timeout->tv_nsec == 0) ?
  	(f64) 0 : (f64) timeout->tv_sec +
  	(f64) timeout->tv_nsec / (f64) 1000000000;
  
        /* select as fine grained sleep */
        if (!nfds)
  	{
  	  if (LDP_DEBUG > 3)
  	    clib_warning ("LDP<%d>: sleeping for %.02f seconds",
  			  getpid (), time_out);
  
  	  time_out += clib_time_now (&ldp->clib_time);
  	  while (clib_time_now (&ldp->clib_time) < time_out)
  	    ;
  	  return 0;
  	}
      }
    else if (!nfds)
      {
        errno = EINVAL;
        return -1;
      }
    else
      time_out = -1;
  
  
    if (nfds <= ldp->sid_bit_val)
      {
        func_str = "libc_pselect";
  
        if (LDP_DEBUG > 3)
  	clib_warning
  	  ("LDP<%d>: calling %s(): nfds %d, readfds %p, writefds %p, "
  	   "exceptfds %p, timeout %p, sigmask %p", getpid (), func_str, nfds,
  	   readfds, writefds, exceptfds, timeout, sigmask);
  
        rv = libc_pselect (nfds, readfds, writefds, exceptfds,
  			 timeout, sigmask);
        goto done;
      }
  
    if (PREDICT_FALSE (ldp->sid_bit_val > FD_SETSIZE / 2))
      {
        clib_warning ("LDP<%d>: ERROR: LDP sid bit value %d (0x%x) > "
  		    "FD_SETSIZE/2 %d (0x%x)!", getpid (),
  		    ldp->sid_bit_val, ldp->sid_bit_val,
  		    FD_SETSIZE / 2, FD_SETSIZE / 2);
        errno = EOVERFLOW;
        return -1;
      }
  
    sid_bits = libc_bits = 0;
    if (readfds)
      {
        clib_bitmap_validate (ldp->sid_rd_bitmap, minbits);
        clib_bitmap_validate (ldp->libc_rd_bitmap, minbits);
        clib_bitmap_validate (ldp->rd_bitmap, minbits);
        clib_memcpy (ldp->rd_bitmap, readfds,
  		   vec_len (ldp->rd_bitmap) * sizeof (clib_bitmap_t));
        FD_ZERO (readfds);
  
        /* *INDENT-OFF* */
        clib_bitmap_foreach (fd, ldp->rd_bitmap,
          ({
            sid = ldp_sid_from_fd (fd);
            if (LDP_DEBUG > 3)
              clib_warning ("LDP<%d>: readfds: fd %d (0x%x), sid %u (0x%x)",
                            getpid (), fd, fd, sid, sid);
            if (sid == INVALID_SESSION_ID)
              clib_bitmap_set_no_check (ldp->libc_rd_bitmap, fd, 1);
            else
              clib_bitmap_set_no_check (ldp->sid_rd_bitmap, sid, 1);
          }));
        /* *INDENT-ON* */
  
        sid_bits_set = clib_bitmap_last_set (ldp->sid_rd_bitmap) + 1;
        sid_bits = (sid_bits_set > sid_bits) ? sid_bits_set : sid_bits;
  
        libc_bits_set = clib_bitmap_last_set (ldp->libc_rd_bitmap) + 1;
        libc_bits = (libc_bits_set > libc_bits) ? libc_bits_set : libc_bits;
  
        if (LDP_DEBUG > 3)
  	clib_warning ("LDP<%d>: readfds: sid_bits_set %d, sid_bits %d, "
  		      "libc_bits_set %d, libc_bits %d", getpid (),
  		      sid_bits_set, sid_bits, libc_bits_set, libc_bits);
      }
    if (writefds)
      {
        clib_bitmap_validate (ldp->sid_wr_bitmap, minbits);
        clib_bitmap_validate (ldp->libc_wr_bitmap, minbits);
        clib_bitmap_validate (ldp->wr_bitmap, minbits);
        clib_memcpy (ldp->wr_bitmap, writefds,
  		   vec_len (ldp->wr_bitmap) * sizeof (clib_bitmap_t));
        FD_ZERO (writefds);
  
        /* *INDENT-OFF* */
        clib_bitmap_foreach (fd, ldp->wr_bitmap,
          ({
            sid = ldp_sid_from_fd (fd);
            if (LDP_DEBUG > 3)
              clib_warning ("LDP<%d>: writefds: fd %d (0x%x), sid %u (0x%x)",
                            getpid (), fd, fd, sid, sid);
            if (sid == INVALID_SESSION_ID)
              clib_bitmap_set_no_check (ldp->libc_wr_bitmap, fd, 1);
            else
              clib_bitmap_set_no_check (ldp->sid_wr_bitmap, sid, 1);
          }));
        /* *INDENT-ON* */
  
        sid_bits_set = clib_bitmap_last_set (ldp->sid_wr_bitmap) + 1;
        sid_bits = (sid_bits_set > sid_bits) ? sid_bits_set : sid_bits;
  
        libc_bits_set = clib_bitmap_last_set (ldp->libc_wr_bitmap) + 1;
        libc_bits = (libc_bits_set > libc_bits) ? libc_bits_set : libc_bits;
  
        if (LDP_DEBUG > 3)
  	clib_warning ("LDP<%d>: writefds: sid_bits_set %d, sid_bits %d, "
  		      "libc_bits_set %d, libc_bits %d", getpid (),
  		      sid_bits_set, sid_bits, libc_bits_set, libc_bits);
      }
    if (exceptfds)
      {
        clib_bitmap_validate (ldp->sid_ex_bitmap, minbits);
        clib_bitmap_validate (ldp->libc_ex_bitmap, minbits);
        clib_bitmap_validate (ldp->ex_bitmap, minbits);
        clib_memcpy (ldp->ex_bitmap, exceptfds,
  		   vec_len (ldp->ex_bitmap) * sizeof (clib_bitmap_t));
        FD_ZERO (exceptfds);
  
        /* *INDENT-OFF* */
        clib_bitmap_foreach (fd, ldp->ex_bitmap,
          ({
            sid = ldp_sid_from_fd (fd);
            if (LDP_DEBUG > 3)
              clib_warning ("LDP<%d>: exceptfds: fd %d (0x%x), sid %u (0x%x)",
                            getpid (), fd, fd, sid, sid);
            if (sid == INVALID_SESSION_ID)
              clib_bitmap_set_no_check (ldp->libc_ex_bitmap, fd, 1);
            else
              clib_bitmap_set_no_check (ldp->sid_ex_bitmap, sid, 1);
          }));
        /* *INDENT-ON* */
  
        sid_bits_set = clib_bitmap_last_set (ldp->sid_ex_bitmap) + 1;
        sid_bits = (sid_bits_set > sid_bits) ? sid_bits_set : sid_bits;
  
        libc_bits_set = clib_bitmap_last_set (ldp->libc_ex_bitmap) + 1;
        libc_bits = (libc_bits_set > libc_bits) ? libc_bits_set : libc_bits;
  
        if (LDP_DEBUG > 3)
  	clib_warning ("LDP<%d>: exceptfds: sid_bits_set %d, sid_bits %d, "
  		      "libc_bits_set %d, libc_bits %d", getpid (),
  		      sid_bits_set, sid_bits, libc_bits_set, libc_bits);
      }
  
    if (PREDICT_FALSE (!sid_bits && !libc_bits))
      {
        errno = EINVAL;
        rv = -1;
        goto done;
      }
  
    do
      {
        if (sid_bits)
  	{
  	  if (!ldp->select_vcl)
  	    {
  	      func_str = "vppcom_select";
  
  	      if (readfds)
  		clib_memcpy (ldp->rd_bitmap, ldp->sid_rd_bitmap,
  			     vec_len (ldp->rd_bitmap) *
  			     sizeof (clib_bitmap_t));
  	      if (writefds)
  		clib_memcpy (ldp->wr_bitmap, ldp->sid_wr_bitmap,
  			     vec_len (ldp->wr_bitmap) *
  			     sizeof (clib_bitmap_t));
  	      if (exceptfds)
  		clib_memcpy (ldp->ex_bitmap, ldp->sid_ex_bitmap,
  			     vec_len (ldp->ex_bitmap) *
  			     sizeof (clib_bitmap_t));
  
  	      rv = vppcom_select (sid_bits,
  				  readfds ? ldp->rd_bitmap : NULL,
  				  writefds ? ldp->wr_bitmap : NULL,
  				  exceptfds ? ldp->ex_bitmap : NULL, 0);
  	      if (rv < 0)
  		{
  		  errno = -rv;
  		  rv = -1;
  		}
  	      else if (rv > 0)
  		{
  		  if (readfds)
  		    {
                        /* *INDENT-OFF* */
                        clib_bitmap_foreach (sid, ldp->rd_bitmap,
                          ({
                            fd = ldp_fd_from_sid (sid);
                            if (PREDICT_FALSE (fd < 0))
                              {
                                errno = EBADFD;
                                rv = -1;
                                goto done;
                              }
                            FD_SET (fd, readfds);
                          }));
                        /* *INDENT-ON* */
  		    }
  		  if (writefds)
  		    {
                        /* *INDENT-OFF* */
                        clib_bitmap_foreach (sid, ldp->wr_bitmap,
                          ({
                            fd = ldp_fd_from_sid (sid);
                            if (PREDICT_FALSE (fd < 0))
                              {
                                errno = EBADFD;
                                rv = -1;
                                goto done;
                              }
                            FD_SET (fd, writefds);
                          }));
                        /* *INDENT-ON* */
  		    }
  		  if (exceptfds)
  		    {
                        /* *INDENT-OFF* */
                        clib_bitmap_foreach (sid, ldp->ex_bitmap,
                          ({
                            fd = ldp_fd_from_sid (sid);
                            if (PREDICT_FALSE (fd < 0))
                              {
                                errno = EBADFD;
                                rv = -1;
                                goto done;
                              }
                            FD_SET (fd, exceptfds);
                          }));
                        /* *INDENT-ON* */
  		    }
  		  ldp->select_vcl = 1;
  		  goto done;
  		}
  	    }
  	  else
  	    ldp->select_vcl = 0;
  	}
        if (libc_bits)
  	{
  	  struct timespec tspec;
  
  	  func_str = "libc_pselect";
  
  	  if (readfds)
  	    clib_memcpy (readfds, ldp->libc_rd_bitmap,
  			 vec_len (ldp->rd_bitmap) * sizeof (clib_bitmap_t));
  	  if (writefds)
  	    clib_memcpy (writefds, ldp->libc_wr_bitmap,
  			 vec_len (ldp->wr_bitmap) * sizeof (clib_bitmap_t));
  	  if (exceptfds)
  	    clib_memcpy (exceptfds, ldp->libc_ex_bitmap,
  			 vec_len (ldp->ex_bitmap) * sizeof (clib_bitmap_t));
  	  tspec.tv_sec = tspec.tv_nsec = 0;
  	  rv = libc_pselect (libc_bits,
  			     readfds ? readfds : NULL,
  			     writefds ? writefds : NULL,
  			     exceptfds ? exceptfds : NULL, &tspec, sigmask);
  	  if (rv != 0)
  	    goto done;
  	}
      }
    while ((time_out == -1) || (clib_time_now (&ldp->clib_time) < time_out));
    rv = 0;
  
  done:
    /* TBD: set timeout to amount of time left */
    vec_reset_length (ldp->rd_bitmap);
    vec_reset_length (ldp->sid_rd_bitmap);
    vec_reset_length (ldp->libc_rd_bitmap);
    vec_reset_length (ldp->wr_bitmap);
    vec_reset_length (ldp->sid_wr_bitmap);
    vec_reset_length (ldp->libc_wr_bitmap);
    vec_reset_length (ldp->ex_bitmap);
    vec_reset_length (ldp->sid_ex_bitmap);
    vec_reset_length (ldp->libc_ex_bitmap);
  
    if (LDP_DEBUG > 3)
      {
        if (rv < 0)
  	{
  	  int errno_val = errno;
  	  perror (func_str);
  	  clib_warning ("LDP<%d>: ERROR: %s() failed! "
  			"rv %d, errno = %d", getpid (),
  			func_str, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: returning %d (0x%x)", getpid (), rv, rv);
      }
    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
  
  int
  socket (int domain, int type, int protocol)
  {
    const char *func_str;
    int rv;
    u8 is_nonblocking = type & SOCK_NONBLOCK ? 1 : 0;
    int 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)))
      {
        int sid;
        u8 proto = ((sock_type == SOCK_DGRAM) ?
  		  VPPCOM_PROTO_UDP : VPPCOM_PROTO_TCP);
  
        func_str = "vppcom_session_create";
  
        LDBG (0, "LDP<%d>: : calling %s(): proto %u (%s), is_nonblocking %u",
  	    getpid (), func_str, proto, vppcom_proto_str (proto),
  	    is_nonblocking);
  
        sid = vppcom_session_create (proto, is_nonblocking);
        if (sid < 0)
  	{
  	  errno = -sid;
  	  rv = -1;
  	}
        else
  	{
  	  func_str = "ldp_fd_from_sid";
  	  rv = ldp_fd_from_sid (sid);
  	  if (rv < 0)
  	    {
  	      (void) vppcom_session_close (sid);
  	      errno = -rv;
  	      rv = -1;
  	    }
  	}
      }
    else
      {
        func_str = "libc_socket";
  
        LDBG (0, "LDP<%d>: : calling %s()", getpid (), func_str);
  
        rv = libc_socket (domain, type, protocol);
      }
  
    if (LDP_DEBUG > 0)
      {
        if (rv < 0)
  	{
  	  int errno_val = errno;
  	  perror (func_str);
  	  clib_warning ("LDP<%d>: ERROR: %s() failed! "
  			"rv %d, errno = %d",
  			getpid (), func_str, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: : returning fd %d (0x%x)", getpid (), rv, rv);
      }
    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])
  {
    const char *func_str;
    int rv;
    int 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)))
      {
        func_str = __func__;
  
        clib_warning ("LDP<%d>: LDP-TBD", getpid ());
        errno = ENOSYS;
        rv = -1;
      }
    else
      {
        func_str = "libc_socket";
  
        if (LDP_DEBUG > 1)
  	clib_warning ("LDP<%d>: : calling %s()", getpid (), func_str);
  
        rv = libc_socket (domain, type, protocol);
      }
  
    if (LDP_DEBUG > 1)
      {
        if (rv < 0)
  	{
  	  int errno_val = errno;
  	  perror (func_str);
  	  clib_warning ("LDP<%d>: ERROR: %s() failed! "
  			"rv %d, errno = %d",
  			getpid (), func_str, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: : returning fd %d (0x%x)", getpid (), rv, rv);
      }
    return rv;
  }
  
  int
  bind (int fd, __CONST_SOCKADDR_ARG addr, socklen_t len)
  {
    int rv;
    const char *func_str;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        vppcom_endpt_t ep;
  
        func_str = "vppcom_session_bind";
  
        switch (addr->sa_family)
  	{
  	case AF_INET:
  	  if (len != sizeof (struct sockaddr_in))
  	    {
  	      clib_warning
  		("LDP<%d>: ERROR: fd %d (0x%x): sid %u (0x%x): Invalid "
  		 "AF_INET addr len %u!", getpid (), fd, fd, sid, sid, 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))
  	    {
  	      clib_warning
  		("LDP<%d>: ERROR: fd %d (0x%x): sid %u (0x%x): Invalid "
  		 "AF_INET6 addr len %u!", getpid (), fd, fd, sid, sid, 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:
  	  clib_warning ("LDP<%d>: ERROR: fd %d (0x%x): sid %u (0x%x): "
  			"Unsupported address family %u!",
  			getpid (), fd, fd, sid, sid, addr->sa_family);
  	  errno = EAFNOSUPPORT;
  	  rv = -1;
  	  goto done;
  	}
        if (LDP_DEBUG > 0)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): sid %u (0x%x), "
  		      "addr %p, len %u",
  		      getpid (), fd, fd, func_str, sid, sid, addr, len);
  
        rv = vppcom_session_bind (sid, &ep);
        if (rv != VPPCOM_OK)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
        func_str = "libc_bind";
  
        if (LDP_DEBUG > 0)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "addr %p, len %u",
  		      getpid (), fd, fd, func_str, addr, len);
  
        rv = libc_bind (fd, addr, len);
      }
  
  done:
    if (LDP_DEBUG > 0)
      {
        if (rv < 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, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: fd %d (0x%x): returning %d (0x%x)",
  		      getpid (), fd, fd, rv, 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)
  {
    int rv;
    const char *func_str;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        vppcom_endpt_t ep;
        u8 addr_buf[sizeof (struct in6_addr)];
        u32 size = sizeof (ep);
  
        ep.ip = addr_buf;
        func_str = "vppcom_session_attr[GET_LCL_ADDR]";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): sid %u (0x%x), "
  		      "addr %p, len %u",
  		      getpid (), fd, fd, func_str, sid, sid, addr, len);
  
        rv = vppcom_session_attr (sid, 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
      {
        func_str = "libc_getsockname";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "addr %p, len %u",
  		      getpid (), fd, fd, func_str, addr, len);
  
        rv = libc_getsockname (fd, addr, len);
      }
  
    if (LDP_DEBUG > 2)
      {
        if (rv < 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, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: fd %d (0x%x): returning %d (0x%x)",
  		      getpid (), fd, fd, rv, rv);
      }
    return rv;
  }
  
  int
  connect (int fd, __CONST_SOCKADDR_ARG addr, socklen_t len)
  {
    int rv;
    const char *func_str = __func__;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (!addr)
      {
        clib_warning ("LDP<%d>: ERROR: fd %d (0x%x): NULL addr, len %u",
  		    getpid (), fd, fd, len);
        errno = EINVAL;
        rv = -1;
        goto done;
      }
  
    if (sid != INVALID_SESSION_ID)
      {
        vppcom_endpt_t ep;
  
        func_str = "vppcom_session_connect";
  
        switch (addr->sa_family)
  	{
  	case AF_INET:
  	  if (len != sizeof (struct sockaddr_in))
  	    {
  	      clib_warning
  		("LDP<%d>: fd %d (0x%x): ERROR sid %u (0x%x): Invalid "
  		 "AF_INET addr len %u!", getpid (), fd, fd, sid, sid, 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))
  	    {
  	      clib_warning
  		("LDP<%d>: fd %d (0x%x): ERROR sid %u (0x%x): Invalid "
  		 "AF_INET6 addr len %u!", getpid (), fd, fd, sid, sid, 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:
  	  clib_warning ("LDP<%d>: fd %d (0x%x): ERROR sid %u (0x%x): "
  			"Unsupported address family %u!",
  			getpid (), fd, fd, sid, sid, addr->sa_family);
  	  errno = EAFNOSUPPORT;
  	  rv = -1;
  	  goto done;
  	}
        if (LDP_DEBUG > 0)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): sid %u (0x%x) "
  		      "addr %p len %u",
  		      getpid (), fd, fd, func_str, sid, sid, addr, len);
  
        rv = vppcom_session_connect (sid, &ep);
        if (rv != VPPCOM_OK)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
        func_str = "libc_connect";
  
        if (LDP_DEBUG > 0)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "addr %p, len %u",
  		      getpid (), fd, fd, func_str, addr, len);
  
        rv = libc_connect (fd, addr, len);
      }
  
  done:
    if (LDP_DEBUG > 0)
      {
        if (rv < 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, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: fd %d (0x%x): returning %d (0x%x)",
  		      getpid (), fd, fd, rv, rv);
      }
    return rv;
  }
  
  int
  getpeername (int fd, __SOCKADDR_ARG addr, socklen_t * __restrict len)
  {
    int rv;
    const char *func_str;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        vppcom_endpt_t ep;
        u8 addr_buf[sizeof (struct in6_addr)];
        u32 size = sizeof (ep);
  
        ep.ip = addr_buf;
        func_str = "vppcom_session_attr[GET_PEER_ADDR]";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): sid %u (0x%x), "
  		      "addr %p, len %u",
  		      getpid (), fd, fd, func_str, sid, sid, addr, len);
  
        rv = vppcom_session_attr (sid, 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
      {
        func_str = "libc_getpeername";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "addr %p, len %u",
  		      getpid (), fd, fd, func_str, addr, len);
  
        rv = libc_getpeername (fd, addr, len);
      }
  
    if (LDP_DEBUG > 2)
      {
        if (rv < 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, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: fd %d (0x%x): returning %d (0x%x)",
  		      getpid (), fd, fd, rv, rv);
      }
    return rv;
  }
  
  ssize_t
  send (int fd, const void *buf, size_t n, int flags)
  {
    ssize_t size;
    const char *func_str;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
  
        func_str = "vppcom_session_sendto";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): sid %u (0x%x), "
  		      "buf %p, n %u, flags 0x%x",
  		      getpid (), fd, fd, func_str, sid, sid, buf, n, flags);
  
        size = vppcom_session_sendto (sid, (void *) buf, n, flags, NULL);
        if (size < VPPCOM_OK)
  	{
  	  errno = -size;
  	  size = -1;
  	}
      }
    else
      {
        func_str = "libc_send";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "buf %p, n %u, flags 0x%x",
  		      getpid (), fd, fd, func_str, buf, n, flags);
  
        size = libc_send (fd, buf, n, 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;
  }
  
  ssize_t
  sendfile (int out_fd, int in_fd, off_t * offset, size_t len)
  {
    ssize_t size = 0;
    const char *func_str;
    u32 sid = ldp_sid_from_fd (out_fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        int rv;
        ssize_t results = 0;
        size_t n_bytes_left = len;
        size_t bytes_to_read;
        int nbytes;
        int errno_val;
        u8 eagain = 0;
        u32 flags, flags_len = sizeof (flags);
  
        func_str = "vppcom_session_attr[GET_FLAGS]";
        rv = vppcom_session_attr (sid, VPPCOM_ATTR_GET_FLAGS, &flags,
  				&flags_len);
        if (PREDICT_FALSE (rv != VPPCOM_OK))
  	{
  	  clib_warning ("LDP<%d>: ERROR: out fd %d (0x%x): %s(): "
  			"sid %u (0x%x), returned %d (%s)!", getpid (),
  			out_fd, out_fd, func_str, sid, sid, rv,
  			vppcom_retval_str (rv));
  
  	  vec_reset_length (ldp->io_buffer);
  	  errno = -rv;
  	  size = -1;
  	  goto done;
  	}
  
        if (offset)
  	{
  	  off_t off = lseek (in_fd, *offset, SEEK_SET);
  	  if (PREDICT_FALSE (off == -1))
  	    {
  	      func_str = "lseek";
  	      errno_val = errno;
  	      clib_warning ("LDP<%d>: ERROR: out fd %d (0x%x): %s(): "
  			    "SEEK_SET failed: in_fd %d, offset %p, "
  			    "*offset %ld, rv %ld, errno %d", getpid (),
  			    out_fd, out_fd, in_fd, offset, *offset, off,
  			    errno_val);
  	      errno = errno_val;
  	      size = -1;
  	      goto done;
  	    }
  
  	  ASSERT (off == *offset);
  	}
  
        do
  	{
  	  func_str = "vppcom_session_attr[GET_NWRITE]";
  	  size = vppcom_session_attr (sid, VPPCOM_ATTR_GET_NWRITE, 0, 0);
  	  if (size < 0)
  	    {
  	      clib_warning
  		("LDP<%d>: ERROR: fd %d (0x%x): %s(): sid %u (0x%x), "
  		 "returned %d (%s)!", getpid (), out_fd, out_fd, func_str,
  		 sid, sid, size, vppcom_retval_str (size));
  	      vec_reset_length (ldp->io_buffer);
  	      errno = -size;
  	      size = -1;
  	      goto done;
  	    }
  
  	  bytes_to_read = size;
  	  if (LDP_DEBUG > 2)
  	    clib_warning
  	      ("LDP<%d>: fd %d (0x%x): called %s(): sid %u (0x%x), "
  	       "results %ld, n_bytes_left %lu, bytes_to_read %lu", getpid (),
  	       out_fd, out_fd, func_str, sid, sid, results, n_bytes_left,
  	       bytes_to_read);
  
  	  if (bytes_to_read == 0)
  	    {
  	      if (flags & O_NONBLOCK)
  		{
  		  if (!results)
  		    {
  		      if (LDP_DEBUG > 2)
  			clib_warning ("LDP<%d>: fd %d (0x%x): sid %u (0x%x): "
  				      "EAGAIN",
  				      getpid (), out_fd, out_fd, sid, sid);
  		      eagain = 1;
  		    }
  		  goto update_offset;
  		}
  	      else
  		continue;
  	    }
  	  bytes_to_read = clib_min (n_bytes_left, bytes_to_read);
  	  vec_validate (ldp->io_buffer, bytes_to_read);
  	  nbytes = libc_read (in_fd, ldp->io_buffer, bytes_to_read);
  	  if (nbytes < 0)
  	    {
  	      func_str = "libc_read";
  	      errno_val = errno;
  	      clib_warning ("LDP<%d>: ERROR: fd %d (0x%x): %s(): in_fd (%d), "
  			    "io_buffer %p, bytes_to_read %lu, rv %d, "
  			    "errno %d", getpid (), out_fd, out_fd, func_str,
  			    in_fd, ldp->io_buffer, bytes_to_read, nbytes,
  			    errno_val);
  	      errno = errno_val;
  
  	      if (results == 0)
  		{
  		  vec_reset_length (ldp->io_buffer);
  		  size = -1;
  		  goto done;
  		}
  	      goto update_offset;
  	    }
  	  func_str = "vppcom_session_write";
  	  if (LDP_DEBUG > 2)
  	    clib_warning
  	      ("LDP<%d>: fd %d (0x%x): calling %s(): sid %u (0x%x), "
  	       "buf %p, nbytes %u: results %d, n_bytes_left %d", getpid (),
  	       out_fd, out_fd, func_str, sid, sid, ldp->io_buffer, nbytes,
  	       results, n_bytes_left);
  
  	  size = vppcom_session_write (sid, ldp->io_buffer, nbytes);
  	  if (size < 0)
  	    {
  	      if (size == VPPCOM_EAGAIN)
  		{
  		  if (flags & O_NONBLOCK)
  		    {
  		      if (!results)
  			{
  			  if (LDP_DEBUG > 2)
  			    clib_warning
  			      ("LDP<%d>: fd %d (0x%x): sid %u (0x%x): "
  			       "EAGAIN", getpid (), out_fd, out_fd, sid, sid);
  			  eagain = 1;
  			}
  		      goto update_offset;
  		    }
  		  else
  		    continue;
  		}
  	      else
  		{
  		  clib_warning ("LDP<%d>: ERROR: fd %d (0x%x): %s():"
  				"sid %u, io_buffer %p, nbytes %u "
  				"returned %d (%s)",
  				getpid (), out_fd, out_fd, func_str,
  				sid, ldp->io_buffer, nbytes,
  				size, vppcom_retval_str (size));
  		}
  	      if (results == 0)
  		{
  		  vec_reset_length (ldp->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 (ldp->io_buffer);
        if (offset)
  	{
  	  off_t off = lseek (in_fd, *offset, SEEK_SET);
  	  if (PREDICT_FALSE (off == -1))
  	    {
  	      func_str = "lseek";
  	      errno_val = errno;
  	      clib_warning ("LDP<%d>: ERROR: %s(): SEEK_SET failed: "
  			    "in_fd %d, offset %p, *offset %ld, "
  			    "rv %ld, errno %d", getpid (), in_fd,
  			    offset, *offset, off, errno_val);
  	      errno = errno_val;
  	      size = -1;
  	      goto done;
  	    }
  
  	  ASSERT (off == *offset);
  	  *offset += results + 1;
  	}
        if (eagain)
  	{
  	  errno = EAGAIN;
  	  size = -1;
  	}
        else
  	size = results;
      }
    else
      {
        func_str = "libc_send";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "in_fd %d, offset %p, len %u",
  		      getpid (), out_fd, out_fd, func_str,
  		      in_fd, offset, len);
  
        size = libc_sendfile (out_fd, in_fd, offset, len);
      }
  
  done:
    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 (), out_fd, out_fd,
  			func_str, size, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: fd %d (0x%x): returning %d (0x%x)",
  		      getpid (), out_fd, out_fd, size, size);
      }
    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)
  {
    ssize_t size;
    const char *func_str;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        func_str = "vppcom_session_recvfrom";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "sid %u (0x%x), buf %p, n %u, flags 0x%x", getpid (),
  		      fd, fd, func_str, sid, sid, buf, n, flags);
  
        size = vppcom_session_recvfrom (sid, buf, n, flags, NULL);
        if (size < 0)
  	{
  	  errno = -size;
  	  size = -1;
  	}
      }
    else
      {
        func_str = "libc_recv";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "buf %p, n %u, flags 0x%x", getpid (),
  		      fd, fd, func_str, buf, n, flags);
  
        size = libc_recv (fd, buf, n, 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;
  }
  
  ssize_t
  sendto (int fd, const void *buf, size_t n, int flags,
  	__CONST_SOCKADDR_ARG addr, socklen_t addr_len)
  {
    ssize_t size;
    const char *func_str = __func__;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        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:
  	      errno = EAFNOSUPPORT;
  	      size = -1;
  	      goto done;
  	    }
  	}
  
        func_str = "vppcom_session_sendto";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "sid %u (0x%x), buf %p, n %u, flags 0x%x, ep %p",
  		      getpid (), fd, fd, func_str, sid, sid, buf, n,
  		      flags, ep);
  
        size = vppcom_session_sendto (sid, (void *) buf, n, flags, ep);
        if (size < 0)
  	{
  	  errno = -size;
  	  size = -1;
  	}
      }
    else
      {
        func_str = "libc_sendto";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "buf %p, n %u, flags 0x%x, addr %p, addr_len %d",
  		      getpid (), fd, fd, func_str, buf, n, flags,
  		      addr, addr_len);
  
        size = libc_sendto (fd, buf, n, flags, addr, addr_len);
      }
  
  done:
    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;
  }
  
  ssize_t
  recvfrom (int fd, void *__restrict buf, size_t n, int flags,
  	  __SOCKADDR_ARG addr, socklen_t * __restrict addr_len)
  {
    ssize_t size;
    const char *func_str;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        vppcom_endpt_t ep;
        u8 src_addr[sizeof (struct sockaddr_in6)];
  
        func_str = "vppcom_session_recvfrom";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "sid %u (0x%x), buf %p, n %u, flags 0x%x, ep %p",
  		      getpid (), fd, fd, func_str, sid, sid, buf, n,
  		      flags, &ep);
        if (addr)
  	{
  	  ep.ip = src_addr;
  	  size = vppcom_session_recvfrom (sid, buf, n, flags, &ep);
  
  	  if (size > 0)
  	    size = ldp_copy_ep_to_sockaddr (addr, addr_len, &ep);
  	}
        else
  	size = vppcom_session_recvfrom (sid, buf, n, flags, NULL);
  
        if (size < 0)
  	{
  	  errno = -size;
  	  size = -1;
  	}
      }
    else
      {
        func_str = "libc_recvfrom";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "buf %p, n %u, flags 0x%x, addr %p, addr_len %d",
  		      getpid (), fd, fd, func_str, buf, n, flags,
  		      addr, addr_len);
  
        size = libc_recvfrom (fd, buf, n, flags, addr, addr_len);
      }
  
    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;
  }
  
  ssize_t
  sendmsg (int fd, const struct msghdr * message, int flags)
  {
    ssize_t size;
    const char *func_str;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        func_str = __func__;
  
        clib_warning ("LDP<%d>: LDP-TBD", getpid ());
        errno = ENOSYS;
        size = -1;
      }
    else
      {
        func_str = "libc_sendmsg";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "message %p, flags 0x%x",
  		      getpid (), fd, fd, func_str, message, flags);
  
        size = libc_sendmsg (fd, message, 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;
  }
  
  #ifdef USE_GNU
  int
  sendmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags)
  {
    ssize_t size;
    const char *func_str;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != 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 * message, int flags)
  {
    ssize_t size;
    const char *func_str;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        func_str = __func__;
  
        clib_warning ("LDP<%d>: LDP-TBD", getpid ());
        errno = ENOSYS;
        size = -1;
      }
    else
      {
        func_str = "libc_recvmsg";
  
        if (LDP_DEBUG > 2)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  		      "message %p, flags 0x%x",
  		      getpid (), fd, fd, func_str, message, flags);
  
        size = libc_recvmsg (fd, message, 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;
  }
  
  #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 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != 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)
  {
    int rv;
    const char *func_str = __func__;
    u32 sid = ldp_sid_from_fd (fd);
    u32 buflen = optlen ? (u32) * optlen : 0;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        rv = -EOPNOTSUPP;
  
        switch (level)
  	{
  	case SOL_TCP:
  	  switch (optname)
  	    {
  	    case TCP_NODELAY:
  	      func_str = "vppcom_session_attr[SOL_TCP,GET_TCP_NODELAY]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x)",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_GET_TCP_NODELAY,
  					optval, optlen);
  	      break;
  	    case TCP_MAXSEG:
  	      func_str = "vppcom_session_attr[SOL_TCP,GET_TCP_USER_MSS]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x)",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_GET_TCP_USER_MSS,
  					optval, optlen);
  	      break;
  	    case TCP_KEEPIDLE:
  	      func_str = "vppcom_session_attr[SOL_TCP,GET_TCP_KEEPIDLE]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x)",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_GET_TCP_KEEPIDLE,
  					optval, optlen);
  	      break;
  	    case TCP_KEEPINTVL:
  	      func_str = "vppcom_session_attr[SOL_TCP,GET_TCP_KEEPINTVL]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x), SOL_TCP",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_GET_TCP_KEEPINTVL,
  					optval, optlen);
  	      break;
  	    case TCP_INFO:
  	      if (optval && optlen && (*optlen == sizeof (struct tcp_info)))
  		{
  		  if (LDP_DEBUG > 1)
  		    clib_warning ("LDP<%d>: fd %d (0x%x): sid %u (0x%x), "
  				  "SOL_TCP, TCP_INFO, optval %p, "
  				  "optlen %d: #LDP-NOP#",
  				  getpid (), fd, fd, sid, sid,
  				  optval, *optlen);
  		  memset (optval, 0, *optlen);
  		  rv = VPPCOM_OK;
  		}
  	      else
  		rv = -EFAULT;
  	      break;
  	    default:
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: ERROR: fd %d (0x%x): %s(): "
  			      "sid %u (0x%x), SOL_TCP, "
  			      "optname %d unsupported!",
  			      getpid (), fd, fd, func_str, sid, sid, optname);
  	      break;
  	    }
  	  break;
  	case SOL_IPV6:
  	  switch (optname)
  	    {
  	    case IPV6_V6ONLY:
  	      func_str = "vppcom_session_attr[SOL_IPV6,GET_V6ONLY]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x)",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_GET_V6ONLY,
  					optval, optlen);
  	      break;
  	    default:
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: ERROR: fd %d (0x%x): %s(): "
  			      "sid %u (0x%x), SOL_IPV6, "
  			      "optname %d unsupported!",
  			      getpid (), fd, fd, func_str, sid, sid, optname);
  	      break;
  	    }
  	  break;
  	case SOL_SOCKET:
  	  switch (optname)
  	    {
  	    case SO_ACCEPTCONN:
  	      func_str = "vppcom_session_attr[SOL_SOCKET,GET_ACCEPTCONN]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x)",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_GET_LISTEN,
  					optval, optlen);
  	      break;
  	    case SO_KEEPALIVE:
  	      func_str = "vppcom_session_attr[SOL_SOCKET,GET_KEEPALIVE]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x)",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_GET_KEEPALIVE,
  					optval, optlen);
  	      break;
  	    case SO_PROTOCOL:
  	      func_str = "vppcom_session_attr[SOL_SOCKET,GET_PROTOCOL]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x)",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_GET_PROTOCOL,
  					optval, optlen);
  	      *(int *) optval = *(int *) optval ? SOCK_DGRAM : SOCK_STREAM;
  	      break;
  	    case SO_SNDBUF:
  	      func_str = "vppcom_session_attr[SOL_SOCKET,GET_TX_FIFO_LEN]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x), optlen %d",
  			      getpid (), fd, fd, func_str, sid, sid, buflen);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_GET_TX_FIFO_LEN,
  					optval, optlen);
  	      break;
  	    case SO_RCVBUF:
  	      func_str = "vppcom_session_attr[SOL_SOCKET,GET_RX_FIFO_LEN]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x), optlen %d",
  			      getpid (), fd, fd, func_str, sid, sid, buflen);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_GET_RX_FIFO_LEN,
  					optval, optlen);
  	      break;
  	    case SO_REUSEADDR:
  	      func_str = "vppcom_session_attr[SOL_SOCKET,GET_REUSEADDR]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x)",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_GET_REUSEADDR,
  					optval, optlen);
  	      break;
  	    case SO_BROADCAST:
  	      func_str = "vppcom_session_attr[SOL_SOCKET,GET_BROADCAST]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x)",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_GET_BROADCAST,
  					optval, optlen);
  	      break;
  	    case SO_ERROR:
  	      func_str = "vppcom_session_attr[SOL_SOCKET,GET_ERROR]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x)",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_GET_ERROR,
  					optval, optlen);
  	      break;
  	    default:
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: ERROR: fd %d (0x%x): %s(): "
  			      "sid %u (0x%x), SOL_SOCKET, "
  			      "optname %d unsupported!",
  			      getpid (), fd, fd, func_str, sid, sid, optname);
  	      break;
  	    }
  	  break;
  	default:
  	  break;
  	}
  
        if (rv != VPPCOM_OK)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
        func_str = "libc_getsockopt";
  
        if (LDP_DEBUG > 1)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): level %d, "
  		      "optname %d, optval %p, optlen %d",
  		      getpid (), fd, fd, func_str, level, optname,
  		      optval, optlen);
  
        rv = libc_getsockopt (fd, level, optname, optval, optlen);
      }
  
    if (LDP_DEBUG > 1)
      {
        if (rv < 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, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: fd %d (0x%x): returning %d (0x%x)",
  		      getpid (), fd, fd, rv, rv);
      }
    return rv;
  }
  
  int
  setsockopt (int fd, int level, int optname,
  	    const void *optval, socklen_t optlen)
  {
    int rv;
    const char *func_str = __func__;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        rv = -EOPNOTSUPP;
  
        switch (level)
  	{
  	case SOL_TCP:
  	  switch (optname)
  	    {
  	    case TCP_NODELAY:
  	      func_str = "vppcom_session_attr[SOL_TCP,SET_TCP_NODELAY]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x)",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_SET_TCP_NODELAY,
  					(void *) optval, &optlen);
  	      break;
  	    case TCP_MAXSEG:
  	      func_str = "vppcom_session_attr[SOL_TCP,SET_TCP_USER_MSS]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x)",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_SET_TCP_USER_MSS,
  					(void *) optval, &optlen);
  	      break;
  	    case TCP_KEEPIDLE:
  	      func_str = "vppcom_session_attr[SOL_TCP,SET_TCP_KEEPIDLE]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x)",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_SET_TCP_KEEPIDLE,
  					(void *) optval, &optlen);
  	      break;
  	    case TCP_KEEPINTVL:
  	      func_str = "vppcom_session_attr[SOL_TCP,SET_TCP_KEEPINTVL]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x), SOL_TCP",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_SET_TCP_KEEPINTVL,
  					(void *) optval, &optlen);
  	      break;
  	    default:
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: ERROR: fd %d (0x%x): %s(): "
  			      "sid %u (0x%x), SOL_TCP, "
  			      "optname %d unsupported!",
  			      getpid (), fd, fd, func_str, sid, sid, optname);
  	      break;
  	    }
  	  break;
  	case SOL_IPV6:
  	  switch (optname)
  	    {
  	    case IPV6_V6ONLY:
  	      func_str = "vppcom_session_attr[SOL_IPV6,SET_V6ONLY]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x)",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_SET_V6ONLY,
  					(void *) optval, &optlen);
  	      break;
  	    default:
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: ERROR: fd %d (0x%x): %s(): "
  			      "sid %u (0x%x), SOL_IPV6, "
  			      "optname %d unsupported!",
  			      getpid (), fd, fd, func_str, sid, sid, optname);
  	      break;
  	    }
  	  break;
  	case SOL_SOCKET:
  	  switch (optname)
  	    {
  	    case SO_KEEPALIVE:
  	      func_str = "vppcom_session_attr[SOL_SOCKET,SET_KEEPALIVE]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x)",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_SET_KEEPALIVE,
  					(void *) optval, &optlen);
  	      break;
  	    case SO_REUSEADDR:
  	      func_str = "vppcom_session_attr[SOL_SOCKET,SET_REUSEADDR]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x)",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_SET_REUSEADDR,
  					(void *) optval, &optlen);
  	      break;
  	    case SO_BROADCAST:
  	      func_str = "vppcom_session_attr[SOL_SOCKET,SET_BROADCAST]";
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
  			      "sid %u (0x%x)",
  			      getpid (), fd, fd, func_str, sid, sid);
  	      rv = vppcom_session_attr (sid, VPPCOM_ATTR_SET_BROADCAST,
  					(void *) optval, &optlen);
  	      break;
  	    default:
  	      if (LDP_DEBUG > 1)
  		clib_warning ("LDP<%d>: ERROR: fd %d (0x%x): %s(): "
  			      "sid %u (0x%x), SOL_SOCKET, "
  			      "optname %d unsupported!",
  			      getpid (), fd, fd, func_str, sid, sid, optname);
  	      break;
  	    }
  	  break;
  	default:
  	  break;
  	}
  
        if (rv != VPPCOM_OK)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
        func_str = "libc_setsockopt";
  
        if (LDP_DEBUG > 1)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): level %d, "
  		      "optname %d, optval %p, optlen %d",
  		      getpid (), fd, fd, func_str, level, optname,
  		      optval, optlen);
  
        rv = libc_setsockopt (fd, level, optname, optval, optlen);
      }
  
    if (LDP_DEBUG > 1)
      {
        if (rv < 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, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: fd %d (0x%x): returning %d (0x%x)",
  		      getpid (), fd, fd, rv, rv);
      }
    return rv;
  }
  
  int
  listen (int fd, int n)
  {
    int rv;
    const char *func_str;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        func_str = "vppcom_session_listen";
  
        LDBG (0, "LDP<%d>: fd %d (0x%x): calling %s(): sid %u (0x%x), n %d",
  	    getpid (), fd, fd, func_str, sid, sid, n);
  
        rv = vppcom_session_listen (sid, n);
        if (rv != VPPCOM_OK)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
        func_str = "libc_listen";
  
        LDBG (0, "LDP<%d>: fd %d (0x%x): calling %s(): n %d", getpid (), fd,
  	    fd, func_str, n);
  
        rv = libc_listen (fd, n);
      }
  
    if (LDP_DEBUG > 0)
      {
        if (rv < 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, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: fd %d (0x%x): returning %d (0x%x)",
  		      getpid (), fd, fd, rv, rv);
      }
    return rv;
  }
  
  static inline int
  ldp_accept4 (int listen_fd, __SOCKADDR_ARG addr,
  	     socklen_t * __restrict addr_len, int flags)
  {
    int rv;
    const char *func_str;
    u32 listen_sid = ldp_sid_from_fd (listen_fd);
    int accept_sid;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (listen_sid != INVALID_SESSION_ID)
      {
        vppcom_endpt_t ep;
        u8 src_addr[sizeof (struct sockaddr_in6)];
        memset (&ep, 0, sizeof (ep));
        ep.ip = src_addr;
  
        func_str = "vppcom_session_accept";
  
        if (LDP_DEBUG > 0)
  	clib_warning ("LDP<%d>: listen fd %d (0x%x): calling %s(): "
  		      "listen sid %u (0x%x), ep %p, flags 0x%x",
  		      getpid (), listen_fd, listen_fd, func_str,
  		      listen_sid, listen_sid, ep, flags);
  
        accept_sid = vppcom_session_accept (listen_sid, &ep, flags);
        if (accept_sid < 0)
  	{
  	  errno = -accept_sid;
  	  rv = -1;
  	}
        else
  	{
  	  rv = ldp_copy_ep_to_sockaddr (addr, addr_len, &ep);
  	  if (rv != VPPCOM_OK)
  	    {
  	      (void) vppcom_session_close ((u32) accept_sid);
  	      errno = -rv;
  	      rv = -1;
  	    }
  	  else
  	    {
  	      func_str = "ldp_fd_from_sid";
  	      if (LDP_DEBUG > 0)
  		clib_warning ("LDP<%d>: listen fd %d (0x%x): calling %s(): "
  			      "accept sid %u (0x%x), ep %p, flags 0x%x",
  			      getpid (), listen_fd, listen_fd,
  			      func_str, accept_sid, accept_sid, ep, flags);
  	      rv = ldp_fd_from_sid ((u32) accept_sid);
  	      if (rv < 0)
  		{
  		  (void) vppcom_session_close ((u32) accept_sid);
  		  errno = -rv;
  		  rv = -1;
  		}
  	    }
  	}
      }
    else
      {
        func_str = "libc_accept4";
  
        if (LDP_DEBUG > 0)
  	clib_warning ("LDP<%d>: listen fd %d (0x%x): calling %s(): "
  		      "addr %p, addr_len %p, flags 0x%x",
  		      getpid (), listen_fd, listen_fd, func_str,
  		      addr, addr_len, flags);
  
        rv = libc_accept4 (listen_fd, addr, addr_len, flags);
      }
  
    if (LDP_DEBUG > 0)
      {
        if (rv < 0)
  	{
  	  int errno_val = errno;
  	  perror (func_str);
  	  clib_warning ("LDP<%d>: ERROR: listen fd %d (0x%x): %s() failed! "
  			"rv %d, errno = %d", getpid (), listen_fd,
  			listen_fd, func_str, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: listen fd %d (0x%x): returning %d (0x%x)",
  		      getpid (), listen_fd, listen_fd, rv, 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)
  {
    int rv;
    const char *func_str;
    u32 sid = ldp_sid_from_fd (fd);
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (sid != INVALID_SESSION_ID)
      {
        func_str = __func__;
  
        clib_warning ("LDP<%d>: LDP-TBD", getpid ());
        errno = ENOSYS;
        rv = -1;
      }
    else
      {
        func_str = "libc_shutdown";
  
        if (LDP_DEBUG > 1)
  	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): how %d",
  		      getpid (), fd, fd, func_str, how);
  
        rv = libc_shutdown (fd, how);
      }
  
    if (LDP_DEBUG > 1)
      {
        if (rv < 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, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: fd %d (0x%x): returning %d (0x%x)",
  		      getpid (), fd, fd, rv, rv);
      }
    return rv;
  }
  
  int
  epoll_create1 (int flags)
  {
    const char *func_str;
    int rv;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (ldp->vcl_needs_real_epoll)
      {
        rv = libc_epoll_create1 (flags);
        ldp->vcl_needs_real_epoll = 0;
        ldp->vcl_mq_epfd = rv;
        LDBG (0, "LDP<%d>: created vcl epfd %u", getpid (), rv);
        return rv;
      }
    func_str = "vppcom_epoll_create";
  
    LDBG (1, "LDP<%d>: calling %s()", getpid (), func_str);
  
    rv = vppcom_epoll_create ();
  
    if (PREDICT_FALSE (rv < 0))
      {
        errno = -rv;
        rv = -1;
      }
    else
      rv = ldp_fd_from_sid ((u32) rv);
  
    if (LDP_DEBUG > 1)
      {
        if (rv < 0)
  	{
  	  int errno_val = errno;
  	  perror (func_str);
  	  clib_warning ("LDP<%d>: ERROR: %s() failed! "
  			"rv %d, errno = %d",
  			getpid (), func_str, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: returning epfd %d (0x%x)", getpid (), rv, rv);
      }
    return rv;
  }
  
  int
  epoll_create (int size)
  {
    return epoll_create1 (0);
  }
  
  int
  epoll_ctl (int epfd, int op, int fd, struct epoll_event *event)
  {
    u32 vep_idx = ldp_sid_from_fd (epfd), sid;
    const char *func_str;
    int rv;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (PREDICT_FALSE (vep_idx == INVALID_SESSION_ID))
      {
        /* 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.
         */
        func_str = "libc_epoll_ctl";
  
        LDBG (1, "LDP<%d>: epfd %d (0x%x): calling %s(): op %d, fd %d (0x%x),"
  	    " event %p", getpid (), epfd, epfd, func_str, op, fd, fd, event);
  
        rv = libc_epoll_ctl (epfd, op, fd, event);
        goto done;
      }
  
    sid = ldp_sid_from_fd (fd);
  
    LDBG (0, "LDP<%d>: epfd %d (0x%x), vep_idx %d (0x%x), sid %d (0x%x)",
  	getpid (), epfd, epfd, vep_idx, vep_idx, sid, sid);
  
    if (sid != INVALID_SESSION_ID)
      {
        func_str = "vppcom_epoll_ctl";
  
        LDBG (1, "LDP<%d>: epfd %d (0x%x): calling %s(): vep_idx %d (0x%x),"
  	    " op %d, sid %u (0x%x), event %p", getpid (), epfd, epfd,
  	    func_str, vep_idx, vep_idx, sid, sid, event);
  
        rv = vppcom_epoll_ctl (vep_idx, op, sid, event);
        if (rv != VPPCOM_OK)
  	{
  	  errno = -rv;
  	  rv = -1;
  	}
      }
    else
      {
        int libc_epfd;
        u32 size = sizeof (epfd);
  
        func_str = "vppcom_session_attr[GET_LIBC_EPFD]";
        libc_epfd = vppcom_session_attr (vep_idx, VPPCOM_ATTR_GET_LIBC_EPFD, 0,
  				       0);
        LDBG (1, "LDP<%d>: epfd %d (0x%x), vep_idx %d (0x%x): %s() "
  	    "returned libc_epfd %d (0x%x)", getpid (), epfd, epfd,
  	    vep_idx, vep_idx, func_str, libc_epfd, libc_epfd);
  
        if (!libc_epfd)
  	{
  	  func_str = "libc_epoll_create1";
  
  	  LDBG (1, "LDP<%d>: epfd %d (0x%x), vep_idx %d (0x%x): "
  		"calling %s(): EPOLL_CLOEXEC", getpid (), epfd, epfd,
  		vep_idx, vep_idx, func_str);
  
  	  libc_epfd = libc_epoll_create1 (EPOLL_CLOEXEC);
  	  if (libc_epfd < 0)
  	    {
  	      rv = libc_epfd;
  	      goto done;
  	    }
  
  	  func_str = "vppcom_session_attr[SET_LIBC_EPFD]";
  	  LDBG (1, "LDP<%d>: epfd %d (0x%x): calling %s(): vep_idx %d (0x%x),"
  		" VPPCOM_ATTR_SET_LIBC_EPFD, libc_epfd %d (0x%x), size %d",
  		getpid (), epfd, epfd, func_str, vep_idx, vep_idx, libc_epfd,
  		libc_epfd, size);
  
  	  rv = vppcom_session_attr (vep_idx, 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;
  	}
  
        func_str = "libc_epoll_ctl";
  
        LDBG (1, "LDP<%d>: epfd %d (0x%x): calling %s(): libc_epfd %d (0x%x), "
  	    "op %d, fd %d (0x%x), event %p", getpid (), epfd, epfd, func_str,
  	    libc_epfd, libc_epfd, op, fd, fd, event);
  
        rv = libc_epoll_ctl (libc_epfd, op, fd, event);
      }
  
  done:
    if (LDP_DEBUG > 1)
      {
        if (rv < 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, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: fd %d (0x%x): returning %d (0x%x)",
  		      getpid (), fd, fd, rv, rv);
      }
    return rv;
  }
  
  static inline int
  ldp_epoll_pwait (int epfd, struct epoll_event *events, int maxevents,
  		 int timeout, const sigset_t * sigmask)
  {
    double time_to_wait = (double) 0, time_out, now = 0;
    u32 vep_idx = ldp_sid_from_fd (epfd);
    int libc_epfd, rv = 0;
    const char *func_str;
  
    if ((errno = -ldp_init ()))
      return -1;
  
    if (PREDICT_FALSE (!events || (timeout < -1)))
      {
        errno = EFAULT;
        return -1;
      }
  
    if (epfd == ldp->vcl_mq_epfd)
      return libc_epoll_pwait (epfd, events, maxevents, timeout, sigmask);
  
    if (PREDICT_FALSE (vep_idx == INVALID_SESSION_ID))
      {
        clib_warning ("LDP<%d>: ERROR: epfd %d (0x%x): bad vep_idx %d (0x%x)!",
  		    getpid (), epfd, epfd, vep_idx, vep_idx);
        errno = EBADFD;
        return -1;
      }
  
    time_to_wait = ((timeout >= 0) ? (double) timeout : 0);
    time_out = clib_time_now (&ldp->clib_time) + time_to_wait;
  
    func_str = "vppcom_session_attr[GET_LIBC_EPFD]";
    libc_epfd = vppcom_session_attr (vep_idx, VPPCOM_ATTR_GET_LIBC_EPFD, 0, 0);
    if (PREDICT_FALSE (libc_epfd < 0))
      {
        errno = -libc_epfd;
        rv = -1;
        goto done;
      }
  
    LDBG (2, "LDP<%d>: epfd %d (0x%x): vep_idx %d (0x%x), libc_epfd %d (0x%x), "
  	"events %p, maxevents %d, timeout %d, sigmask %p: time_to_wait %.02f",
  	getpid (), epfd, epfd, vep_idx, vep_idx, libc_epfd, libc_epfd, events,
  	maxevents, timeout, sigmask, time_to_wait, time_out);
    do
      {
        if (!ldp->epoll_wait_vcl)
  	{
  	  func_str = "vppcom_epoll_wait";
  
  	  LDBG (3, "LDP<%d>: epfd %d (0x%x): calling %s(): vep_idx %d (0x%x),"
  		" events %p, maxevents %d", getpid (), epfd, epfd, func_str,
  		vep_idx, vep_idx, events, maxevents);
  
  	  rv = vppcom_epoll_wait (vep_idx, events, maxevents, 0);
  	  if (rv > 0)
  	    {
  	      ldp->epoll_wait_vcl = 1;
  	      goto done;
  	    }
  	  else if (rv < 0)
  	    {
  	      errno = -rv;
  	      rv = -1;
  	      goto done;
  	    }
  	}
        else
  	ldp->epoll_wait_vcl = 0;
  
        if (libc_epfd > 0)
  	{
  	  func_str = "libc_epoll_pwait";
  
  	  LDBG (3, "LDP<%d>: epfd %d (0x%x): calling %s(): libc_epfd %d "
  		"(0x%x), events %p, maxevents %d, sigmask %p", getpid (),
  		epfd, epfd, func_str, libc_epfd, libc_epfd, events,
  		maxevents, sigmask);
  
  	  rv = libc_epoll_pwait (libc_epfd, events, maxevents, 1, sigmask);
  	  if (rv != 0)
  	    goto done;
  	}
  
        if (timeout != -1)
  	now = clib_time_now (&ldp->clib_time);
      }
    while (now < time_out);
  
  done:
    if (LDP_DEBUG > 3)
      {
        if (libc_epfd > 0)
  	epfd = libc_epfd;
        if (rv < 0)
  	{
  	  int errno_val = errno;
  	  perror (func_str);
  	  clib_warning ("LDP<%d>: ERROR: epfd %d (0x%x): %s() failed! "
  			"rv %d, errno = %d", getpid (), epfd, epfd,
  			func_str, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	clib_warning ("LDP<%d>: epfd %d (0x%x): returning %d (0x%x)",
  		      getpid (), epfd, epfd, rv, rv);
      }
    return rv;
  }
  
  int
  epoll_pwait (int epfd, struct epoll_event *events,
  	     int maxevents, int timeout, const sigset_t * sigmask)
  {
    return ldp_epoll_pwait (epfd, events, maxevents, timeout, sigmask);
  }
  
  int
  epoll_wait (int epfd, struct epoll_event *events, int maxevents, int timeout)
  {
    return ldp_epoll_pwait (epfd, events, maxevents, timeout, NULL);
  }
  
  int
  poll (struct pollfd *fds, nfds_t nfds, int timeout)
  {
    const char *func_str = __func__;
    int rv, i, n_libc_fds, n_revents;
    u32 sid;
    vcl_poll_t *vp;
    double wait_for_time;
  
    if (LDP_DEBUG > 3)
      clib_warning ("LDP<%d>: fds %p, nfds %d, timeout %d",
  		  getpid (), fds, nfds, timeout);
  
    if (timeout >= 0)
      wait_for_time = (f64) timeout / 1000;
    else
      wait_for_time = -1;
  
    n_libc_fds = 0;
    for (i = 0; i < nfds; i++)
      {
        if (fds[i].fd >= 0)
  	{
  	  if (LDP_DEBUG > 3)
  	    clib_warning ("LDP<%d>: fds[%d].fd %d (0x%0x), .events = 0x%x, "
  			  ".revents = 0x%x", getpid (), i, fds[i].fd,
  			  fds[i].fd, fds[i].events, fds[i].revents);
  
  	  sid = ldp_sid_from_fd (fds[i].fd);
  	  if (sid != INVALID_SESSION_ID)
  	    {
  	      fds[i].fd = -fds[i].fd;
  	      vec_add2 (ldp->vcl_poll, vp, 1);
  	      vp->fds_ndx = i;
  	      vp->sid = sid;
  	      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
  	    n_libc_fds++;
  	}
      }
  
    n_revents = 0;
    do
      {
        if (vec_len (ldp->vcl_poll))
  	{
  	  func_str = "vppcom_poll";
  
  	  if (LDP_DEBUG > 3)
  	    clib_warning ("LDP<%d>: calling %s(): "
  			  "vcl_poll %p, n_sids %u (0x%x): "
  			  "n_libc_fds %u",
  			  getpid (), func_str, ldp->vcl_poll,
  			  vec_len (ldp->vcl_poll), vec_len (ldp->vcl_poll),
  			  n_libc_fds);
  
  	  rv = vppcom_poll (ldp->vcl_poll, vec_len (ldp->vcl_poll), 0);
  	  if (rv < 0)
  	    {
  	      errno = -rv;
  	      rv = -1;
  	      goto done;
  	    }
  	  else
  	    n_revents += rv;
  	}
  
        if (n_libc_fds)
  	{
  	  func_str = "libc_poll";
  
  	  if (LDP_DEBUG > 3)
  	    clib_warning ("LDP<%d>: calling %s(): fds %p, nfds %u: n_sids %u",
  			  getpid (), fds, nfds, vec_len (ldp->vcl_poll));
  
  	  rv = libc_poll (fds, nfds, 0);
  	  if (rv < 0)
  	    goto done;
  	  else
  	    n_revents += rv;
  	}
  
        if (n_revents)
  	{
  	  rv = n_revents;
  	  goto done;
  	}
      }
    while ((wait_for_time == -1) ||
  	 (clib_time_now (&ldp->clib_time) < wait_for_time));
    rv = 0;
  
  done:
    vec_foreach (vp, ldp->vcl_poll)
    {
      fds[vp->fds_ndx].fd = -fds[vp->fds_ndx].fd;
  #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 (ldp->vcl_poll);
  
    if (LDP_DEBUG > 3)
      {
        if (rv < 0)
  	{
  	  int errno_val = errno;
  	  perror (func_str);
  	  clib_warning ("LDP<%d>: ERROR: %s() failed! "
  			"rv %d, errno = %d", getpid (),
  			func_str, rv, errno_val);
  	  errno = errno_val;
  	}
        else
  	{
  	  clib_warning ("LDP<%d>: returning %d (0x%x): n_sids %u, "
  			"n_libc_fds %d", getpid (), rv, rv,
  			vec_len (ldp->vcl_poll), n_libc_fds);
  
  	  for (i = 0; i < nfds; i++)
  	    {
  	      if (fds[i].fd >= 0)
  		{
  		  if (LDP_DEBUG > 3)
  		    clib_warning ("LDP<%d>: fds[%d].fd %d (0x%0x), "
  				  ".events = 0x%x, .revents = 0x%x",
  				  getpid (), i, fds[i].fd, fds[i].fd,
  				  fds[i].events, fds[i].revents);
  		}
  	    }
  	}
      }
  
    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 ());
    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)
      {
        vppcom_app_destroy ();
        ldp->init = 0;
      }
  
    /* Don't use clib_warning() here because that calls writev()
     * which will call ldp_init().
     */
    if (LDP_DEBUG > 0)
      printf ("%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:
   */
  