/*

 * clnt_tcp.c, Implements a TCP/IP based, client side RPC.

 *

 * Copyright (c) 2010, Oracle America, Inc.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are

 * met:

 *

 *     * Redistributions of source code must retain the above copyright

 *       notice, this list of conditions and the following disclaimer.

 *     * Redistributions in binary form must reproduce the above

 *       copyright notice, this list of conditions and the following

 *       disclaimer in the documentation and/or other materials

 *       provided with the distribution.

 *     * Neither the name of the "Oracle America, Inc." nor the names of its

 *       contributors may be used to endorse or promote products derived

 *       from this software without specific prior written permission.

 *

 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS

 *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE

 *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,

 *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE

 *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,

 *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

 *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 *

 * TCP based RPC supports 'batched calls'.

 * A sequence of calls may be batched-up in a send buffer.  The rpc call

 * return immediately to the client even though the call was not necessarily

 * sent.  The batching occurs if the results' xdr routine is NULL (0) AND

 * the rpc timeout value is zero (see clnt.h, rpc).

 *

 * Clients should NOT casually batch calls that in fact return results; that is,

 * the server side should be aware that a call is batched and not produce any

 * return message.  Batched calls that produce many result messages can

 * deadlock (netlock) the client and the server....

 *

 * Now go hang yourself.

 */

#include <netdb.h>

#include <errno.h>

#include <stdio.h>

#include <unistd.h>

#include <libintl.h>

#include <rpc/rpc.h>

#include <sys/poll.h>

#include <sys/socket.h>

#include <rpc/pmap_clnt.h>

#include <wchar.h>

#include <shlib-compat.h>

extern u_long _create_xid (void);

#define MCALL_MSG_SIZE 24

struct ct_data

  {

    int ct_sock;

    bool_t ct_closeit;

    struct timeval ct_wait;

    bool_t ct_waitset;		/* wait set by clnt_control? */

    struct sockaddr_in ct_addr;

    struct rpc_err ct_error;

    char ct_mcall[MCALL_MSG_SIZE];	/* marshalled callmsg */

    u_int ct_mpos;		/* pos after marshal */

    XDR ct_xdrs;

  };

static int readtcp (char *, char *, int);

static int writetcp (char *, char *, int);

static enum clnt_stat clnttcp_call (CLIENT *, u_long, xdrproc_t, caddr_t,

				    xdrproc_t, caddr_t, struct timeval);

static void clnttcp_abort (void);

static void clnttcp_geterr (CLIENT *, struct rpc_err *);

static bool_t clnttcp_freeres (CLIENT *, xdrproc_t, caddr_t);

static bool_t clnttcp_control (CLIENT *, int, char *);

static void clnttcp_destroy (CLIENT *);

static const struct clnt_ops tcp_ops =

{

  clnttcp_call,

  clnttcp_abort,

  clnttcp_geterr,

  clnttcp_freeres,

  clnttcp_destroy,

  clnttcp_control

};

/*

 * Create a client handle for a tcp/ip connection.

 * If *sockp<0, *sockp is set to a newly created TCP socket and it is

 * connected to raddr.  If *sockp non-negative then

 * raddr is ignored.  The rpc/tcp package does buffering

 * similar to stdio, so the client must pick send and receive buffer sizes,];

 * 0 => use the default.

 * If raddr->sin_port is 0, then a binder on the remote machine is

 * consulted for the right port number.

 * NB: *sockp is copied into a private area.

 * NB: It is the clients responsibility to close *sockp.

 * NB: The rpch->cl_auth is set null authentication.  Caller may wish to set this

 * something more useful.

 */

CLIENT *

clnttcp_create (struct sockaddr_in *raddr, u_long prog, u_long vers,

		int *sockp, u_int sendsz, u_int recvsz)

{

  CLIENT *h;

  struct ct_data *ct;

  struct rpc_msg call_msg;

  h = (CLIENT *) mem_alloc (sizeof (*h));

  ct = (struct ct_data *) mem_alloc (sizeof (*ct));

  if (h == NULL || ct == NULL)

    {

      struct rpc_createerr *ce = &get_rpc_createerr ();

      (void) __fxprintf (NULL, "%s: %s", __func__, _("out of memory\n"));

      ce->cf_stat = RPC_SYSTEMERROR;

      ce->cf_error.re_errno = ENOMEM;

      goto fooy;

    }

  /*

   * If no port number given ask the pmap for one

   */

  if (raddr->sin_port == 0)

    {

      u_short port;

      if ((port = pmap_getport (raddr, prog, vers, IPPROTO_TCP)) == 0)

	{

	  mem_free ((caddr_t) ct, sizeof (struct ct_data));

	  mem_free ((caddr_t) h, sizeof (CLIENT));

	  return ((CLIENT *) NULL);

	}

      raddr->sin_port = htons (port);

    }

  /*

   * If no socket given, open one

   */

  if (*sockp < 0)

    {

      *sockp = __socket (AF_INET, SOCK_STREAM, IPPROTO_TCP);

      (void) bindresvport (*sockp, (struct sockaddr_in *) 0);

      if ((*sockp < 0)

	  || (__connect (*sockp, (struct sockaddr *) raddr,

			 sizeof (*raddr)) < 0))

	{

	  struct rpc_createerr *ce = &get_rpc_createerr ();

	  ce->cf_stat = RPC_SYSTEMERROR;

	  ce->cf_error.re_errno = errno;

	  if (*sockp >= 0)

	    (void) __close (*sockp);

	  goto fooy;

	}

      ct->ct_closeit = TRUE;

    }

  else

    {

      ct->ct_closeit = FALSE;

    }

  /*

   * Set up private data struct

   */

  ct->ct_sock = *sockp;

  ct->ct_wait.tv_usec = 0;

  ct->ct_waitset = FALSE;

  ct->ct_addr = *raddr;

  /*

   * Initialize call message

   */

  call_msg.rm_xid = _create_xid ();

  call_msg.rm_direction = CALL;

  call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;

  call_msg.rm_call.cb_prog = prog;

  call_msg.rm_call.cb_vers = vers;

  /*

   * pre-serialize the static part of the call msg and stash it away

   */

  xdrmem_create (&(ct->ct_xdrs), ct->ct_mcall, MCALL_MSG_SIZE, XDR_ENCODE);

  if (!xdr_callhdr (&(ct->ct_xdrs), &call_msg))

    {

      if (ct->ct_closeit)

	{

	  (void) __close (*sockp);

	}

      goto fooy;

    }

  ct->ct_mpos = XDR_GETPOS (&(ct->ct_xdrs));

  XDR_DESTROY (&(ct->ct_xdrs));

  /*

   * Create a client handle which uses xdrrec for serialization

   * and authnone for authentication.

   */

  xdrrec_create (&(ct->ct_xdrs), sendsz, recvsz,

		 (caddr_t) ct, readtcp, writetcp);

  h->cl_ops = (struct clnt_ops *) &tcp_ops;

  h->cl_private = (caddr_t) ct;

  h->cl_auth = authnone_create ();

  return h;

fooy:

  /*

   * Something goofed, free stuff and barf

   */

  mem_free ((caddr_t) ct, sizeof (struct ct_data));

  mem_free ((caddr_t) h, sizeof (CLIENT));

  return ((CLIENT *) NULL);

}

#ifdef EXPORT_RPC_SYMBOLS

libc_hidden_def (clnttcp_create)

#else

libc_hidden_nolink_sunrpc (clnttcp_create, GLIBC_2_0)

#endif

static enum clnt_stat

clnttcp_call (CLIENT *h, u_long proc, xdrproc_t xdr_args, caddr_t args_ptr,

	      xdrproc_t xdr_results, caddr_t results_ptr,

	      struct timeval timeout)

{

  struct ct_data *ct = (struct ct_data *) h->cl_private;

  XDR *xdrs = &(ct->ct_xdrs);

  struct rpc_msg reply_msg;

  u_long x_id;

  uint32_t *msg_x_id = (uint32_t *) (ct->ct_mcall);	/* yuk */

  bool_t shipnow;

  int refreshes = 2;

  if (!ct->ct_waitset)

    {

      ct->ct_wait = timeout;

    }

  shipnow =

    (xdr_results == (xdrproc_t) 0 && ct->ct_wait.tv_sec == 0

     && ct->ct_wait.tv_usec == 0) ? FALSE : TRUE;

call_again:

  xdrs->x_op = XDR_ENCODE;

  ct->ct_error.re_status = RPC_SUCCESS;

  x_id = ntohl (--(*msg_x_id));

  if ((!XDR_PUTBYTES (xdrs, ct->ct_mcall, ct->ct_mpos)) ||

      (!XDR_PUTLONG (xdrs, (long *) &proc)) ||

      (!AUTH_MARSHALL (h->cl_auth, xdrs)) ||

      (!(*xdr_args) (xdrs, args_ptr)))

    {

      if (ct->ct_error.re_status == RPC_SUCCESS)

	ct->ct_error.re_status = RPC_CANTENCODEARGS;

      (void) xdrrec_endofrecord (xdrs, TRUE);

      return (ct->ct_error.re_status);

    }

  if (!xdrrec_endofrecord (xdrs, shipnow))

    return ct->ct_error.re_status = RPC_CANTSEND;

  if (!shipnow)

    return RPC_SUCCESS;

  /*

   * Hack to provide rpc-based message passing

   */

  if (ct->ct_wait.tv_sec == 0 && ct->ct_wait.tv_usec == 0)

    {

      return ct->ct_error.re_status = RPC_TIMEDOUT;

    }

  /*

   * Keep receiving until we get a valid transaction id

   */

  xdrs->x_op = XDR_DECODE;

  while (TRUE)

    {

      reply_msg.acpted_rply.ar_verf = _null_auth;

      reply_msg.acpted_rply.ar_results.where = NULL;

      reply_msg.acpted_rply.ar_results.proc = (xdrproc_t)xdr_void;

      if (!xdrrec_skiprecord (xdrs))

	return (ct->ct_error.re_status);

      /* now decode and validate the response header */

      if (!xdr_replymsg (xdrs, &reply_msg))

	{

	  if (ct->ct_error.re_status == RPC_SUCCESS)

	    continue;

	  return ct->ct_error.re_status;

	}

      if ((uint32_t) reply_msg.rm_xid == (uint32_t) x_id)

	break;

    }

  /*

   * process header

   */

  _seterr_reply (&reply_msg, &(ct->ct_error));

  if (ct->ct_error.re_status == RPC_SUCCESS)

    {

      if (!AUTH_VALIDATE (h->cl_auth, &reply_msg.acpted_rply.ar_verf))

	{

	  ct->ct_error.re_status = RPC_AUTHERROR;

	  ct->ct_error.re_why = AUTH_INVALIDRESP;

	}

      else if (!(*xdr_results) (xdrs, results_ptr))

	{

	  if (ct->ct_error.re_status == RPC_SUCCESS)

	    ct->ct_error.re_status = RPC_CANTDECODERES;

	}

      /* free verifier ... */

      if (reply_msg.acpted_rply.ar_verf.oa_base != NULL)

	{

	  xdrs->x_op = XDR_FREE;

	  (void) xdr_opaque_auth (xdrs, &(reply_msg.acpted_rply.ar_verf));

	}

    }				/* end successful completion */

  else

    {

      /* maybe our credentials need to be refreshed ... */

      if (refreshes-- && AUTH_REFRESH (h->cl_auth))

	goto call_again;

    }				/* end of unsuccessful completion */

  return ct->ct_error.re_status;

}

static void

clnttcp_geterr (CLIENT *h, struct rpc_err *errp)

{

  struct ct_data *ct =

  (struct ct_data *) h->cl_private;

  *errp = ct->ct_error;

}

static bool_t

clnttcp_freeres (CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr)

{

  struct ct_data *ct = (struct ct_data *) cl->cl_private;

  XDR *xdrs = &(ct->ct_xdrs);

  xdrs->x_op = XDR_FREE;

  return (*xdr_res) (xdrs, res_ptr);

}

static void

clnttcp_abort (void)

{

}

static bool_t

clnttcp_control (CLIENT *cl, int request, char *info)

{

  struct ct_data *ct = (struct ct_data *) cl->cl_private;

  u_long ul;

  uint32_t ui32;

  switch (request)

    {

    case CLSET_FD_CLOSE:

      ct->ct_closeit = TRUE;

      break;

    case CLSET_FD_NCLOSE:

      ct->ct_closeit = FALSE;

      break;

    case CLSET_TIMEOUT:

      ct->ct_wait = *(struct timeval *) info;

      ct->ct_waitset = TRUE;

      break;

    case CLGET_TIMEOUT:

      *(struct timeval *) info = ct->ct_wait;

      break;

    case CLGET_SERVER_ADDR:

      *(struct sockaddr_in *) info = ct->ct_addr;

      break;

    case CLGET_FD:

      *(int *)info = ct->ct_sock;

      break;

    case CLGET_XID:

      /*

       * use the knowledge that xid is the

       * first element in the call structure *.

       * This will get the xid of the PREVIOUS call

       */

      memcpy (&ui32, ct->ct_mcall, sizeof (ui32));

      ul = ntohl (ui32);

      memcpy (info, &ul, sizeof (ul));

      break;

    case CLSET_XID:

      /* This will set the xid of the NEXT call */

      memcpy (&ul, info, sizeof (ul));

      ui32 = htonl (ul - 1);

      memcpy (ct->ct_mcall, &ui32, sizeof (ui32));

      /* decrement by 1 as clnttcp_call() increments once */

      break;

    case CLGET_VERS:

      /*

       * This RELIES on the information that, in the call body,

       * the version number field is the fifth field from the

       * beginning of the RPC header. MUST be changed if the

       * call_struct is changed

       */

      memcpy (&ui32, ct->ct_mcall + 4 * BYTES_PER_XDR_UNIT, sizeof (ui32));

      ul = ntohl (ui32);

      memcpy (info, &ul, sizeof (ul));

      break;

    case CLSET_VERS:

      memcpy (&ul, info, sizeof (ul));

      ui32 = htonl (ul);

      memcpy (ct->ct_mcall + 4 * BYTES_PER_XDR_UNIT, &ui32, sizeof (ui32));

      break;

    case CLGET_PROG:

      /*

       * This RELIES on the information that, in the call body,

       * the program number field is the  field from the

       * beginning of the RPC header. MUST be changed if the

       * call_struct is changed

       */

      memcpy (&ui32, ct->ct_mcall + 3 * BYTES_PER_XDR_UNIT, sizeof (ui32));

      ul = ntohl (ui32);

      memcpy (info, &ul, sizeof (ul));

      break;

    case CLSET_PROG:

      memcpy (&ul, info, sizeof (ul));

      ui32 = htonl (ul);

      memcpy (ct->ct_mcall + 3 * BYTES_PER_XDR_UNIT, &ui32, sizeof (ui32));

      break;

    /* The following are only possible with TI-RPC */

    case CLGET_RETRY_TIMEOUT:

    case CLSET_RETRY_TIMEOUT:

    case CLGET_SVC_ADDR:

    case CLSET_SVC_ADDR:

    case CLSET_PUSH_TIMOD:

    case CLSET_POP_TIMOD:

    default:

      return FALSE;

    }

  return TRUE;

}

static void

clnttcp_destroy (CLIENT *h)

{

  struct ct_data *ct =

  (struct ct_data *) h->cl_private;

  if (ct->ct_closeit)

    {

      (void) __close (ct->ct_sock);

    }

  XDR_DESTROY (&(ct->ct_xdrs));

  mem_free ((caddr_t) ct, sizeof (struct ct_data));

  mem_free ((caddr_t) h, sizeof (CLIENT));

}

/*

 * Interface between xdr serializer and tcp connection.

 * Behaves like the system calls, read & write, but keeps some error state

 * around for the rpc level.

 */

static int

readtcp (char *ctptr, char *buf, int len)

{

  struct ct_data *ct = (struct ct_data *)ctptr;

  struct pollfd fd;

  int milliseconds = (ct->ct_wait.tv_sec * 1000) +

    (ct->ct_wait.tv_usec / 1000);

  if (len == 0)

    return 0;

  fd.fd = ct->ct_sock;

  fd.events = POLLIN;

  while (TRUE)

    {

      switch (__poll(&fd, 1, milliseconds))

	{

	case 0:

	  ct->ct_error.re_status = RPC_TIMEDOUT;

	  return -1;

	case -1:

	  if (errno == EINTR)

	    continue;

	  ct->ct_error.re_status = RPC_CANTRECV;

	  ct->ct_error.re_errno = errno;

	  return -1;

	}

      break;

    }

  switch (len = __read (ct->ct_sock, buf, len))

    {

    case 0:

      /* premature eof */

      ct->ct_error.re_errno = ECONNRESET;

      ct->ct_error.re_status = RPC_CANTRECV;

      len = -1;			/* it's really an error */

      break;

    case -1:

      ct->ct_error.re_errno = errno;

      ct->ct_error.re_status = RPC_CANTRECV;

      break;

    }

  return len;

}

static int

writetcp (char *ctptr, char *buf, int len)

{

  int i, cnt;

  struct ct_data *ct = (struct ct_data*)ctptr;

  for (cnt = len; cnt > 0; cnt -= i, buf += i)

    {

      if ((i = __write (ct->ct_sock, buf, cnt)) == -1)

	{

	  ct->ct_error.re_errno = errno;

	  ct->ct_error.re_status = RPC_CANTSEND;

	  return -1;

	}

    }

  return len;

}