src/vlibmemory/socket_client.c - fdio/vpp - Gitiles

 /*
  *------------------------------------------------------------------
  * socket_client.c - API message handling over sockets, client code.
  *
  * Copyright (c) 2017 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 <stdio.h>
 #define __USE_GNU
 #define _GNU_SOURCE
 #include <sys/socket.h>

 #include <svm/ssvm.h>
 #include <vlibmemory/socket_client.h>
 #include <vlibmemory/memory_client.h>

 #include <vlibmemory/vl_memory_msg_enum.h>

 #define vl_typedefs		/* define message structures */
 #include <vlibmemory/vl_memory_api_h.h>
 #undef vl_typedefs

 #define vl_endianfun		/* define message structures */
 #include <vlibmemory/vl_memory_api_h.h>
 #undef vl_endianfun

 #define vl_calcsizefun
 #include <vlibmemory/vl_memory_api_h.h>
 #undef vl_calcsizefun

 /* instantiate all the print functions we know about */
 #define vl_print(handle, ...) clib_warning (__VA_ARGS__)
 #define vl_printfun
 #include <vlibmemory/vl_memory_api_h.h>
 #undef vl_printfun

 socket_client_main_t socket_client_main;
 __thread socket_client_main_t *socket_client_ctx = &socket_client_main;

 /* Debug aid */
 u32 vl (void *p) __attribute__ ((weak));

 u32
 vl (void *p)
 {
   return vec_len (p);
 }

 static socket_client_main_t *
 vl_socket_client_ctx_push (socket_client_main_t * ctx)
 {
   socket_client_main_t *old = socket_client_ctx;
   socket_client_ctx = ctx;
   return old;
 }

 static void
 vl_socket_client_ctx_pop (socket_client_main_t * old_ctx)
 {
   socket_client_ctx = old_ctx;
 }

 static int
 vl_socket_client_read_internal (socket_client_main_t * scm, int wait)
 {
   u32 data_len = 0, msg_size;
   int n, current_rx_index;
   msgbuf_t *mbp = 0;
   f64 timeout;

   if (scm->socket_fd == 0)
     return -1;

   if (wait)
     timeout = clib_time_now (&scm->clib_time) + wait;

   while (1)
     {
       while (vec_len (scm->socket_rx_buffer) < sizeof (*mbp))
 	{
 	  current_rx_index = vec_len (scm->socket_rx_buffer);
 	  vec_validate (scm->socket_rx_buffer, current_rx_index
 			+ scm->socket_buffer_size - 1);
 	  _vec_len (scm->socket_rx_buffer) = current_rx_index;
 	  n = read (scm->socket_fd, scm->socket_rx_buffer + current_rx_index,
 		    scm->socket_buffer_size);
 	  if (n < 0)
 	    {
 	      if (errno == EAGAIN)
 		continue;

 	      clib_unix_warning ("socket_read");
 	      return -1;
 	    }
 	  _vec_len (scm->socket_rx_buffer) += n;
 	}

 #if CLIB_DEBUG > 1
       if (n > 0)
 	clib_warning ("read %d bytes", n);
 #endif

       mbp = (msgbuf_t *) (scm->socket_rx_buffer);
       data_len = ntohl (mbp->data_len);
       current_rx_index = vec_len (scm->socket_rx_buffer);
       vec_validate (scm->socket_rx_buffer, current_rx_index + data_len);
       _vec_len (scm->socket_rx_buffer) = current_rx_index;
       mbp = (msgbuf_t *) (scm->socket_rx_buffer);
       msg_size = data_len + sizeof (*mbp);

       while (vec_len (scm->socket_rx_buffer) < msg_size)
 	{
 	  n = read (scm->socket_fd,
 		    scm->socket_rx_buffer + vec_len (scm->socket_rx_buffer),
 		    msg_size - vec_len (scm->socket_rx_buffer));
 	  if (n < 0)
 	    {
 	      if (errno == EAGAIN)
 		continue;

 	      clib_unix_warning ("socket_read");
 	      return -1;
 	    }
 	  _vec_len (scm->socket_rx_buffer) += n;
 	}

       if (vec_len (scm->socket_rx_buffer) >= data_len + sizeof (*mbp))
 	{
 	  vl_msg_api_socket_handler ((void *) (mbp->data), data_len);

 	  if (vec_len (scm->socket_rx_buffer) == data_len + sizeof (*mbp))
 	    _vec_len (scm->socket_rx_buffer) = 0;
 	  else
 	    vec_delete (scm->socket_rx_buffer, data_len + sizeof (*mbp), 0);
 	  mbp = 0;

 	  /* Quit if we're out of data, and not expecting a ping reply */
 	  if (vec_len (scm->socket_rx_buffer) == 0
 	      && scm->control_pings_outstanding == 0)
 	    break;
 	}
       if (wait && clib_time_now (&scm->clib_time) >= timeout)
 	return -1;
     }
   return 0;
 }

 int
 vl_socket_client_read (int wait)
 {
   return vl_socket_client_read_internal (socket_client_ctx, wait);
 }

 int
 vl_socket_client_read2 (socket_client_main_t * scm, int wait)
 {
   socket_client_main_t *old_ctx;
   int rv;

   old_ctx = vl_socket_client_ctx_push (scm);
   rv = vl_socket_client_read_internal (scm, wait);
   vl_socket_client_ctx_pop (old_ctx);
   return rv;
 }

 static int
 vl_socket_client_write_internal (socket_client_main_t * scm)
 {
   int n;

   msgbuf_t msgbuf = {
     .q = 0,
     .gc_mark_timestamp = 0,
     .data_len = htonl (scm->socket_tx_nbytes),
   };

   n = write (scm->socket_fd, &msgbuf, sizeof (msgbuf));
   if (n < sizeof (msgbuf))
     {
       clib_unix_warning ("socket write (msgbuf)");
       return -1;
     }

   n = write (scm->socket_fd, scm->socket_tx_buffer, scm->socket_tx_nbytes);
   if (n < scm->socket_tx_nbytes)
     {
       clib_unix_warning ("socket write (msg)");
       return -1;
     }

   return n;
 }

 int
 vl_socket_client_write (void)
 {
   return vl_socket_client_write_internal (socket_client_ctx);
 }

 int
 vl_socket_client_write2 (socket_client_main_t * scm)
 {
   socket_client_main_t *old_ctx;
   int rv;

   old_ctx = vl_socket_client_ctx_push (scm);
   rv = vl_socket_client_write_internal (scm);
   vl_socket_client_ctx_pop (old_ctx);
   return rv;
 }

 void *
 vl_socket_client_msg_alloc2 (socket_client_main_t * scm, int nbytes)
 {
   scm->socket_tx_nbytes = nbytes;
   return ((void *) scm->socket_tx_buffer);
 }

 void *
 vl_socket_client_msg_alloc (int nbytes)
 {
   return vl_socket_client_msg_alloc2 (socket_client_ctx, nbytes);
 }

 void
 vl_socket_client_disconnect2 (socket_client_main_t * scm)
 {
   if (vl_mem_client_is_connected ())
     {
       vl_client_disconnect_from_vlib_no_unmap ();
       ssvm_delete_memfd (&scm->memfd_segment);
     }
   if (scm->socket_fd && (close (scm->socket_fd) < 0))
     clib_unix_warning ("close");
   scm->socket_fd = 0;
 }

 void
 vl_socket_client_disconnect (void)
 {
   vl_socket_client_disconnect2 (socket_client_ctx);
 }

 void
 vl_socket_client_enable_disable2 (socket_client_main_t * scm, int enable)
 {
   scm->socket_enable = enable;
 }

 void
 vl_socket_client_enable_disable (int enable)
 {
   vl_socket_client_enable_disable2 (socket_client_ctx, enable);
 }

 static clib_error_t *
 vl_sock_api_recv_fd_msg_internal (socket_client_main_t * scm, int fds[],
 				  int n_fds, u32 wait)
 {
   char msgbuf[16];
   char ctl[CMSG_SPACE (sizeof (int) * n_fds)
 	   + CMSG_SPACE (sizeof (struct ucred))];
   struct msghdr mh = { 0 };
   struct iovec iov[1];
   ssize_t size = 0;
   struct ucred *cr = 0;
   struct cmsghdr *cmsg;
   pid_t pid __attribute__ ((unused));
   uid_t uid __attribute__ ((unused));
   gid_t gid __attribute__ ((unused));
   int socket_fd;
   f64 timeout;

   socket_fd = scm->client_socket.fd;

   iov[0].iov_base = msgbuf;
   iov[0].iov_len = 5;
   mh.msg_iov = iov;
   mh.msg_iovlen = 1;
   mh.msg_control = ctl;
   mh.msg_controllen = sizeof (ctl);

   clib_memset (ctl, 0, sizeof (ctl));

   if (wait != ~0)
     {
       timeout = clib_time_now (&scm->clib_time) + wait;
       while (size != 5 && clib_time_now (&scm->clib_time) < timeout)
 	size = recvmsg (socket_fd, &mh, MSG_DONTWAIT);
     }
   else
     size = recvmsg (socket_fd, &mh, 0);

   if (size != 5)
     {
       return (size == 0) ? clib_error_return (0, "disconnected") :
 	clib_error_return_unix (0, "recvmsg: malformed message (fd %d)",
 				socket_fd);
     }

   cmsg = CMSG_FIRSTHDR (&mh);
   while (cmsg)
     {
       if (cmsg->cmsg_level == SOL_SOCKET)
 	{
 	  if (cmsg->cmsg_type == SCM_CREDENTIALS)
 	    {
 	      cr = (struct ucred *) CMSG_DATA (cmsg);
 	      uid = cr->uid;
 	      gid = cr->gid;
 	      pid = cr->pid;
 	    }
 	  else if (cmsg->cmsg_type == SCM_RIGHTS)
 	    {
 	      clib_memcpy_fast (fds, CMSG_DATA (cmsg), sizeof (int) * n_fds);
 	    }
 	}
       cmsg = CMSG_NXTHDR (&mh, cmsg);
     }
   return 0;
 }

 clib_error_t *
 vl_sock_api_recv_fd_msg (int socket_fd, int fds[], int n_fds, u32 wait)
 {
   return vl_sock_api_recv_fd_msg_internal (socket_client_ctx, fds, n_fds,
 					   wait);
 }

 clib_error_t *
 vl_sock_api_recv_fd_msg2 (socket_client_main_t * scm, int socket_fd,
 			  int fds[], int n_fds, u32 wait)
 {
   socket_client_main_t *old_ctx;
   clib_error_t *error;

   old_ctx = vl_socket_client_ctx_push (scm);
   error = vl_sock_api_recv_fd_msg_internal (scm, fds, n_fds, wait);
   vl_socket_client_ctx_pop (old_ctx);
   return error;
 }

 static void vl_api_sock_init_shm_reply_t_handler
   (vl_api_sock_init_shm_reply_t * mp)
 {
   socket_client_main_t *scm = socket_client_ctx;
   ssvm_private_t *memfd = &scm->memfd_segment;
   i32 retval = ntohl (mp->retval);
   api_main_t *am = vlibapi_get_main ();
   clib_error_t *error;
   int my_fd = -1;
   u8 *new_name;

   if (retval)
     {
       clib_warning ("failed to init shmem");
       return;
     }

   /*
    * Check the socket for the magic fd
    */
   error = vl_sock_api_recv_fd_msg (scm->socket_fd, &my_fd, 1, 5);
   if (error)
     {
       clib_error_report (error);
       retval = -99;
       return;
     }

   clib_memset (memfd, 0, sizeof (*memfd));
   memfd->fd = my_fd;

   /* Note: this closes memfd.fd */
   retval = ssvm_client_init_memfd (memfd);
   if (retval)
     clib_warning ("WARNING: segment map returned %d", retval);

   /*
    * Pivot to the memory client segment that vpp just created
    */
   am->vlib_rp = (void *) (memfd->requested_va + MMAP_PAGESIZE);
   am->shmem_hdr = (void *) am->vlib_rp->user_ctx;

   new_name = format (0, "%v[shm]%c", scm->name, 0);
   vl_client_install_client_message_handlers ();
   if (scm->want_shm_pthread)
     {
       vl_client_connect_to_vlib_no_map ("pvt", (char *) new_name,
 					32 /* input_queue_length */ );
     }
   else
     {
       vl_client_connect_to_vlib_no_rx_pthread_no_map ("pvt",
 						      (char *) new_name, 32
 						      /* input_queue_length */
 	);
     }
   vl_socket_client_enable_disable (0);
   vec_free (new_name);
 }

 static void
 vl_api_sockclnt_create_reply_t_handler (vl_api_sockclnt_create_reply_t * mp)
 {
   socket_client_main_t *scm = socket_client_ctx;
   if (!mp->response)
     {
       scm->socket_enable = 1;
       scm->client_index = clib_net_to_host_u32 (mp->index);
     }
 }

 #define foreach_sock_client_api_msg             		\
 _(SOCKCLNT_CREATE_REPLY, sockclnt_create_reply)			\
 _(SOCK_INIT_SHM_REPLY, sock_init_shm_reply)     		\

 static void
 noop_handler (void *notused)
 {
 }

 void
 vl_sock_client_install_message_handlers (void)
 {

 #define _(N, n)                                                               \
   vl_msg_api_set_handlers (                                                   \
     VL_API_##N, #n, vl_api_##n##_t_handler, noop_handler,                     \
     vl_api_##n##_t_endian, vl_api_##n##_t_print, sizeof (vl_api_##n##_t), 0,  \
     vl_api_##n##_t_print_json, vl_api_##n##_t_tojson,                         \
     vl_api_##n##_t_fromjson, vl_api_##n##_t_calc_size);
   foreach_sock_client_api_msg;
 #undef _
 }

 int
 vl_socket_client_connect_internal (socket_client_main_t * scm,
 				   char *socket_path, char *client_name,
 				   u32 socket_buffer_size)
 {
   vl_api_sockclnt_create_t *mp;
   clib_socket_t *sock;
   clib_error_t *error;

   /* Already connected? */
   if (scm->socket_fd)
     return (-2);

   /* bogus call? */
   if (socket_path == 0 || client_name == 0)
     return (-3);

   sock = &scm->client_socket;
   sock->config = socket_path;
   sock->flags = CLIB_SOCKET_F_IS_CLIENT;

   if ((error = clib_socket_init (sock)))
     {
       clib_error_report (error);
       return (-1);
     }

   vl_sock_client_install_message_handlers ();

   scm->socket_fd = sock->fd;
   scm->socket_buffer_size = socket_buffer_size ? socket_buffer_size :
     SOCKET_CLIENT_DEFAULT_BUFFER_SIZE;
   vec_validate (scm->socket_tx_buffer, scm->socket_buffer_size - 1);
   vec_validate (scm->socket_rx_buffer, scm->socket_buffer_size - 1);
   _vec_len (scm->socket_rx_buffer) = 0;
   _vec_len (scm->socket_tx_buffer) = 0;
   scm->name = format (0, "%s", client_name);

   mp = vl_socket_client_msg_alloc2 (scm, sizeof (*mp));
   mp->_vl_msg_id = htons (VL_API_SOCKCLNT_CREATE);
   strncpy ((char *) mp->name, client_name, sizeof (mp->name) - 1);
   mp->name[sizeof (mp->name) - 1] = 0;
   mp->context = 0xfeedface;

   clib_time_init (&scm->clib_time);

   if (vl_socket_client_write_internal (scm) <= 0)
     return (-1);

   if (vl_socket_client_read_internal (scm, 5))
     return (-1);

   return (0);
 }

 int
 vl_socket_client_connect (char *socket_path, char *client_name,
 			  u32 socket_buffer_size)
 {
   return vl_socket_client_connect_internal (socket_client_ctx, socket_path,
 					    client_name, socket_buffer_size);
 }

 int
 vl_socket_client_connect2 (socket_client_main_t * scm, char *socket_path,
 			   char *client_name, u32 socket_buffer_size)
 {
   socket_client_main_t *old_ctx;
   int rv;

   old_ctx = vl_socket_client_ctx_push (scm);
   rv = vl_socket_client_connect_internal (socket_client_ctx, socket_path,
 					  client_name, socket_buffer_size);
   vl_socket_client_ctx_pop (old_ctx);
   return rv;
 }

 int
 vl_socket_client_init_shm_internal (socket_client_main_t * scm,
 				    vl_api_shm_elem_config_t * config,
 				    int want_pthread)
 {
   vl_api_sock_init_shm_t *mp;
   int rv, i;
   u64 *cfg;

   scm->want_shm_pthread = want_pthread;

   mp = vl_socket_client_msg_alloc2 (scm, sizeof (*mp) +
 				    vec_len (config) * sizeof (u64));
   clib_memset (mp, 0, sizeof (*mp));
   mp->_vl_msg_id = clib_host_to_net_u16 (VL_API_SOCK_INIT_SHM);
   mp->client_index = clib_host_to_net_u32 (scm->client_index);
   mp->requested_size = 64 << 20;

   if (config)
     {
       for (i = 0; i < vec_len (config); i++)
 	{
 	  cfg = (u64 *) & config[i];
 	  mp->configs[i] = *cfg;
 	}
       mp->nitems = vec_len (config);
     }
   rv = vl_socket_client_write_internal (scm);
   if (rv <= 0)
     return rv;

   if (vl_socket_client_read_internal (scm, 1))
     return -1;

   return 0;
 }

 int
 vl_socket_client_init_shm (vl_api_shm_elem_config_t * config,
 			   int want_pthread)
 {
   return vl_socket_client_init_shm_internal (socket_client_ctx, config,
 					     want_pthread);
 }

 int
 vl_socket_client_init_shm2 (socket_client_main_t * scm,
 			    vl_api_shm_elem_config_t * config,
 			    int want_pthread)
 {
   socket_client_main_t *old_ctx;
   int rv;

   old_ctx = vl_socket_client_ctx_push (scm);
   rv = vl_socket_client_init_shm_internal (socket_client_ctx, config,
 					   want_pthread);
   vl_socket_client_ctx_pop (old_ctx);
   return rv;
 }

 clib_error_t *
 vl_socket_client_recv_fd_msg2 (socket_client_main_t * scm, int fds[],
 			       int n_fds, u32 wait)
 {
   if (!scm->socket_fd)
     return clib_error_return (0, "no socket");
   return vl_sock_api_recv_fd_msg_internal (scm, fds, n_fds, wait);
 }

 clib_error_t *
 vl_socket_client_recv_fd_msg (int fds[], int n_fds, u32 wait)
 {
   return vl_socket_client_recv_fd_msg2 (socket_client_ctx, fds, n_fds, wait);
 }

 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	*------------------------------------------------------------------
	* socket_client.c - API message handling over sockets, client code.
	*
	* Copyright (c) 2017 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 <stdio.h>
	#define __USE_GNU
	#define _GNU_SOURCE
	#include <sys/socket.h>

	#include <svm/ssvm.h>
	#include <vlibmemory/socket_client.h>
	#include <vlibmemory/memory_client.h>

	#include <vlibmemory/vl_memory_msg_enum.h>

	#define vl_typedefs /* define message structures */
	#include <vlibmemory/vl_memory_api_h.h>
	#undef vl_typedefs

	#define vl_endianfun /* define message structures */
	#include <vlibmemory/vl_memory_api_h.h>
	#undef vl_endianfun

	#define vl_calcsizefun
	#include <vlibmemory/vl_memory_api_h.h>
	#undef vl_calcsizefun

	/* instantiate all the print functions we know about */
	#define vl_print(handle, ...) clib_warning (__VA_ARGS__)
	#define vl_printfun
	#include <vlibmemory/vl_memory_api_h.h>
	#undef vl_printfun

	socket_client_main_t socket_client_main;
	__thread socket_client_main_t *socket_client_ctx = &socket_client_main;

	/* Debug aid */
	u32 vl (void *p) __attribute__ ((weak));

	u32
	vl (void *p)
	{
	return vec_len (p);
	}

	static socket_client_main_t *
	vl_socket_client_ctx_push (socket_client_main_t * ctx)
	{
	socket_client_main_t *old = socket_client_ctx;
	socket_client_ctx = ctx;
	return old;
	}

	static void
	vl_socket_client_ctx_pop (socket_client_main_t * old_ctx)
	{
	socket_client_ctx = old_ctx;
	}

	static int
	vl_socket_client_read_internal (socket_client_main_t * scm, int wait)
	{
	u32 data_len = 0, msg_size;
	int n, current_rx_index;
	msgbuf_t *mbp = 0;
	f64 timeout;

	if (scm->socket_fd == 0)
	return -1;

	if (wait)
	timeout = clib_time_now (&scm->clib_time) + wait;

	while (1)
	{
	while (vec_len (scm->socket_rx_buffer) < sizeof (*mbp))
	{
	current_rx_index = vec_len (scm->socket_rx_buffer);
	vec_validate (scm->socket_rx_buffer, current_rx_index
	+ scm->socket_buffer_size - 1);
	_vec_len (scm->socket_rx_buffer) = current_rx_index;
	n = read (scm->socket_fd, scm->socket_rx_buffer + current_rx_index,
	scm->socket_buffer_size);
	if (n < 0)
	{
	if (errno == EAGAIN)
	continue;

	clib_unix_warning ("socket_read");
	return -1;
	}
	_vec_len (scm->socket_rx_buffer) += n;
	}

	#if CLIB_DEBUG > 1
	if (n > 0)
	clib_warning ("read %d bytes", n);
	#endif

	mbp = (msgbuf_t *) (scm->socket_rx_buffer);
	data_len = ntohl (mbp->data_len);
	current_rx_index = vec_len (scm->socket_rx_buffer);
	vec_validate (scm->socket_rx_buffer, current_rx_index + data_len);
	_vec_len (scm->socket_rx_buffer) = current_rx_index;
	mbp = (msgbuf_t *) (scm->socket_rx_buffer);
	msg_size = data_len + sizeof (*mbp);

	while (vec_len (scm->socket_rx_buffer) < msg_size)
	{
	n = read (scm->socket_fd,
	scm->socket_rx_buffer + vec_len (scm->socket_rx_buffer),
	msg_size - vec_len (scm->socket_rx_buffer));
	if (n < 0)
	{
	if (errno == EAGAIN)
	continue;

	clib_unix_warning ("socket_read");
	return -1;
	}
	_vec_len (scm->socket_rx_buffer) += n;
	}

	if (vec_len (scm->socket_rx_buffer) >= data_len + sizeof (*mbp))
	{
	vl_msg_api_socket_handler ((void *) (mbp->data), data_len);

	if (vec_len (scm->socket_rx_buffer) == data_len + sizeof (*mbp))
	_vec_len (scm->socket_rx_buffer) = 0;
	else
	vec_delete (scm->socket_rx_buffer, data_len + sizeof (*mbp), 0);
	mbp = 0;

	/* Quit if we're out of data, and not expecting a ping reply */
	if (vec_len (scm->socket_rx_buffer) == 0
	&& scm->control_pings_outstanding == 0)
	break;
	}
	if (wait && clib_time_now (&scm->clib_time) >= timeout)
	return -1;
	}
	return 0;
	}

	int
	vl_socket_client_read (int wait)
	{
	return vl_socket_client_read_internal (socket_client_ctx, wait);
	}

	int
	vl_socket_client_read2 (socket_client_main_t * scm, int wait)
	{
	socket_client_main_t *old_ctx;
	int rv;

	old_ctx = vl_socket_client_ctx_push (scm);
	rv = vl_socket_client_read_internal (scm, wait);
	vl_socket_client_ctx_pop (old_ctx);
	return rv;
	}

	static int
	vl_socket_client_write_internal (socket_client_main_t * scm)
	{
	int n;

	msgbuf_t msgbuf = {
	.q = 0,
	.gc_mark_timestamp = 0,
	.data_len = htonl (scm->socket_tx_nbytes),
	};

	n = write (scm->socket_fd, &msgbuf, sizeof (msgbuf));
	if (n < sizeof (msgbuf))
	{
	clib_unix_warning ("socket write (msgbuf)");
	return -1;
	}

	n = write (scm->socket_fd, scm->socket_tx_buffer, scm->socket_tx_nbytes);
	if (n < scm->socket_tx_nbytes)
	{
	clib_unix_warning ("socket write (msg)");
	return -1;
	}

	return n;
	}

	int
	vl_socket_client_write (void)
	{
	return vl_socket_client_write_internal (socket_client_ctx);
	}

	int
	vl_socket_client_write2 (socket_client_main_t * scm)
	{
	socket_client_main_t *old_ctx;
	int rv;

	old_ctx = vl_socket_client_ctx_push (scm);
	rv = vl_socket_client_write_internal (scm);
	vl_socket_client_ctx_pop (old_ctx);
	return rv;
	}

	void *
	vl_socket_client_msg_alloc2 (socket_client_main_t * scm, int nbytes)
	{
	scm->socket_tx_nbytes = nbytes;
	return ((void *) scm->socket_tx_buffer);
	}

	void *
	vl_socket_client_msg_alloc (int nbytes)
	{
	return vl_socket_client_msg_alloc2 (socket_client_ctx, nbytes);
	}

	void
	vl_socket_client_disconnect2 (socket_client_main_t * scm)
	{
	if (vl_mem_client_is_connected ())
	{
	vl_client_disconnect_from_vlib_no_unmap ();
	ssvm_delete_memfd (&scm->memfd_segment);
	}
	if (scm->socket_fd && (close (scm->socket_fd) < 0))
	clib_unix_warning ("close");
	scm->socket_fd = 0;
	}

	void
	vl_socket_client_disconnect (void)
	{
	vl_socket_client_disconnect2 (socket_client_ctx);
	}

	void
	vl_socket_client_enable_disable2 (socket_client_main_t * scm, int enable)
	{
	scm->socket_enable = enable;
	}

	void
	vl_socket_client_enable_disable (int enable)
	{
	vl_socket_client_enable_disable2 (socket_client_ctx, enable);
	}

	static clib_error_t *
	vl_sock_api_recv_fd_msg_internal (socket_client_main_t * scm, int fds[],
	int n_fds, u32 wait)
	{
	char msgbuf[16];
	char ctl[CMSG_SPACE (sizeof (int) * n_fds)
	+ CMSG_SPACE (sizeof (struct ucred))];
	struct msghdr mh = { 0 };
	struct iovec iov[1];
	ssize_t size = 0;
	struct ucred *cr = 0;
	struct cmsghdr *cmsg;
	pid_t pid __attribute__ ((unused));
	uid_t uid __attribute__ ((unused));
	gid_t gid __attribute__ ((unused));
	int socket_fd;
	f64 timeout;

	socket_fd = scm->client_socket.fd;

	iov[0].iov_base = msgbuf;
	iov[0].iov_len = 5;
	mh.msg_iov = iov;
	mh.msg_iovlen = 1;
	mh.msg_control = ctl;
	mh.msg_controllen = sizeof (ctl);

	clib_memset (ctl, 0, sizeof (ctl));

	if (wait != ~0)
	{
	timeout = clib_time_now (&scm->clib_time) + wait;
	while (size != 5 && clib_time_now (&scm->clib_time) < timeout)
	size = recvmsg (socket_fd, &mh, MSG_DONTWAIT);
	}
	else
	size = recvmsg (socket_fd, &mh, 0);

	if (size != 5)
	{
	return (size == 0) ? clib_error_return (0, "disconnected") :
	clib_error_return_unix (0, "recvmsg: malformed message (fd %d)",
	socket_fd);
	}

	cmsg = CMSG_FIRSTHDR (&mh);
	while (cmsg)
	{
	if (cmsg->cmsg_level == SOL_SOCKET)
	{
	if (cmsg->cmsg_type == SCM_CREDENTIALS)
	{
	cr = (struct ucred *) CMSG_DATA (cmsg);
	uid = cr->uid;
	gid = cr->gid;
	pid = cr->pid;
	}
	else if (cmsg->cmsg_type == SCM_RIGHTS)
	{
	clib_memcpy_fast (fds, CMSG_DATA (cmsg), sizeof (int) * n_fds);
	}
	}
	cmsg = CMSG_NXTHDR (&mh, cmsg);
	}
	return 0;
	}

	clib_error_t *
	vl_sock_api_recv_fd_msg (int socket_fd, int fds[], int n_fds, u32 wait)
	{
	return vl_sock_api_recv_fd_msg_internal (socket_client_ctx, fds, n_fds,
	wait);
	}

	clib_error_t *
	vl_sock_api_recv_fd_msg2 (socket_client_main_t * scm, int socket_fd,
	int fds[], int n_fds, u32 wait)
	{
	socket_client_main_t *old_ctx;
	clib_error_t *error;

	old_ctx = vl_socket_client_ctx_push (scm);
	error = vl_sock_api_recv_fd_msg_internal (scm, fds, n_fds, wait);
	vl_socket_client_ctx_pop (old_ctx);
	return error;
	}

	static void vl_api_sock_init_shm_reply_t_handler
	(vl_api_sock_init_shm_reply_t * mp)
	{
	socket_client_main_t *scm = socket_client_ctx;
	ssvm_private_t *memfd = &scm->memfd_segment;
	i32 retval = ntohl (mp->retval);
	api_main_t *am = vlibapi_get_main ();
	clib_error_t *error;
	int my_fd = -1;
	u8 *new_name;

	if (retval)
	{
	clib_warning ("failed to init shmem");
	return;
	}

	/*
	* Check the socket for the magic fd
	*/
	error = vl_sock_api_recv_fd_msg (scm->socket_fd, &my_fd, 1, 5);
	if (error)
	{
	clib_error_report (error);
	retval = -99;
	return;
	}

	clib_memset (memfd, 0, sizeof (*memfd));
	memfd->fd = my_fd;

	/* Note: this closes memfd.fd */
	retval = ssvm_client_init_memfd (memfd);
	if (retval)
	clib_warning ("WARNING: segment map returned %d", retval);

	/*
	* Pivot to the memory client segment that vpp just created
	*/
	am->vlib_rp = (void *) (memfd->requested_va + MMAP_PAGESIZE);
	am->shmem_hdr = (void *) am->vlib_rp->user_ctx;

	new_name = format (0, "%v[shm]%c", scm->name, 0);
	vl_client_install_client_message_handlers ();
	if (scm->want_shm_pthread)
	{
	vl_client_connect_to_vlib_no_map ("pvt", (char *) new_name,
	32 /* input_queue_length */ );
	}
	else
	{
	vl_client_connect_to_vlib_no_rx_pthread_no_map ("pvt",
	(char *) new_name, 32
	/* input_queue_length */
	);
	}
	vl_socket_client_enable_disable (0);
	vec_free (new_name);
	}

	static void
	vl_api_sockclnt_create_reply_t_handler (vl_api_sockclnt_create_reply_t * mp)
	{
	socket_client_main_t *scm = socket_client_ctx;
	if (!mp->response)
	{
	scm->socket_enable = 1;
	scm->client_index = clib_net_to_host_u32 (mp->index);
	}
	}

	#define foreach_sock_client_api_msg \
	_(SOCKCLNT_CREATE_REPLY, sockclnt_create_reply) \
	_(SOCK_INIT_SHM_REPLY, sock_init_shm_reply) \

	static void
	noop_handler (void *notused)
	{
	}

	void
	vl_sock_client_install_message_handlers (void)
	{

	#define _(N, n) \
	vl_msg_api_set_handlers ( \
	VL_API_##N, #n, vl_api_##n##_t_handler, noop_handler, \
	vl_api_##n##_t_endian, vl_api_##n##_t_print, sizeof (vl_api_##n##_t), 0, \
	vl_api_##n##_t_print_json, vl_api_##n##_t_tojson, \
	vl_api_##n##_t_fromjson, vl_api_##n##_t_calc_size);
	foreach_sock_client_api_msg;
	#undef _
	}

	int
	vl_socket_client_connect_internal (socket_client_main_t * scm,
	char socket_path, char client_name,
	u32 socket_buffer_size)
	{
	vl_api_sockclnt_create_t *mp;
	clib_socket_t *sock;
	clib_error_t *error;

	/* Already connected? */
	if (scm->socket_fd)
	return (-2);

	/* bogus call? */
	if (socket_path == 0 \|\| client_name == 0)
	return (-3);

	sock = &scm->client_socket;
	sock->config = socket_path;
	sock->flags = CLIB_SOCKET_F_IS_CLIENT;

	if ((error = clib_socket_init (sock)))
	{
	clib_error_report (error);
	return (-1);
	}

	vl_sock_client_install_message_handlers ();

	scm->socket_fd = sock->fd;
	scm->socket_buffer_size = socket_buffer_size ? socket_buffer_size :
	SOCKET_CLIENT_DEFAULT_BUFFER_SIZE;
	vec_validate (scm->socket_tx_buffer, scm->socket_buffer_size - 1);
	vec_validate (scm->socket_rx_buffer, scm->socket_buffer_size - 1);
	_vec_len (scm->socket_rx_buffer) = 0;
	_vec_len (scm->socket_tx_buffer) = 0;
	scm->name = format (0, "%s", client_name);

	mp = vl_socket_client_msg_alloc2 (scm, sizeof (*mp));
	mp->_vl_msg_id = htons (VL_API_SOCKCLNT_CREATE);
	strncpy ((char *) mp->name, client_name, sizeof (mp->name) - 1);
	mp->name[sizeof (mp->name) - 1] = 0;
	mp->context = 0xfeedface;

	clib_time_init (&scm->clib_time);

	if (vl_socket_client_write_internal (scm) <= 0)
	return (-1);

	if (vl_socket_client_read_internal (scm, 5))
	return (-1);

	return (0);
	}

	int
	vl_socket_client_connect (char socket_path, char client_name,
	u32 socket_buffer_size)
	{
	return vl_socket_client_connect_internal (socket_client_ctx, socket_path,
	client_name, socket_buffer_size);
	}

	int
	vl_socket_client_connect2 (socket_client_main_t * scm, char *socket_path,
	char *client_name, u32 socket_buffer_size)
	{
	socket_client_main_t *old_ctx;
	int rv;

	old_ctx = vl_socket_client_ctx_push (scm);
	rv = vl_socket_client_connect_internal (socket_client_ctx, socket_path,
	client_name, socket_buffer_size);
	vl_socket_client_ctx_pop (old_ctx);
	return rv;
	}

	int
	vl_socket_client_init_shm_internal (socket_client_main_t * scm,
	vl_api_shm_elem_config_t * config,
	int want_pthread)
	{
	vl_api_sock_init_shm_t *mp;
	int rv, i;
	u64 *cfg;

	scm->want_shm_pthread = want_pthread;

	mp = vl_socket_client_msg_alloc2 (scm, sizeof (*mp) +
	vec_len (config) * sizeof (u64));
	clib_memset (mp, 0, sizeof (*mp));
	mp->_vl_msg_id = clib_host_to_net_u16 (VL_API_SOCK_INIT_SHM);
	mp->client_index = clib_host_to_net_u32 (scm->client_index);
	mp->requested_size = 64 << 20;

	if (config)
	{
	for (i = 0; i < vec_len (config); i++)
	{
	cfg = (u64 *) & config[i];
	mp->configs[i] = *cfg;
	}
	mp->nitems = vec_len (config);
	}
	rv = vl_socket_client_write_internal (scm);
	if (rv <= 0)
	return rv;

	if (vl_socket_client_read_internal (scm, 1))
	return -1;

	return 0;
	}

	int
	vl_socket_client_init_shm (vl_api_shm_elem_config_t * config,
	int want_pthread)
	{
	return vl_socket_client_init_shm_internal (socket_client_ctx, config,
	want_pthread);
	}

	int
	vl_socket_client_init_shm2 (socket_client_main_t * scm,
	vl_api_shm_elem_config_t * config,
	int want_pthread)
	{
	socket_client_main_t *old_ctx;
	int rv;

	old_ctx = vl_socket_client_ctx_push (scm);
	rv = vl_socket_client_init_shm_internal (socket_client_ctx, config,
	want_pthread);
	vl_socket_client_ctx_pop (old_ctx);
	return rv;
	}

	clib_error_t *
	vl_socket_client_recv_fd_msg2 (socket_client_main_t * scm, int fds[],
	int n_fds, u32 wait)
	{
	if (!scm->socket_fd)
	return clib_error_return (0, "no socket");
	return vl_sock_api_recv_fd_msg_internal (scm, fds, n_fds, wait);
	}

	clib_error_t *
	vl_socket_client_recv_fd_msg (int fds[], int n_fds, u32 wait)
	{
	return vl_socket_client_recv_fd_msg2 (socket_client_ctx, fds, n_fds, wait);
	}

	/*
	* fd.io coding-style-patch-verification: ON
	*
	* Local Variables:
	* eval: (c-set-style "gnu")
	* End:
	*/