clnt_unix.c

一个嵌入式C库

/*
 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
 * unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify Sun RPC without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user.
 *
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 *
 * Sun RPC is provided with no support and without any obligation on the
 * part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 *
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
 * OR ANY PART THEREOF.
 *
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 *
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */

/*
 * clnt_unix.c, Implements a TCP/IP based, client side RPC.
 *
 * Copyright (C) 1984, Sun Microsystems, Inc.
 *
 * 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.
 */

#define __FORCE_GLIBC
#include <features.h>

#include <netdb.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <rpc/rpc.h>
#include <sys/uio.h>
#include <sys/poll.h>
#include <sys/socket.h>
#include <rpc/pmap_clnt.h>
#ifdef USE_IN_LIBIO
# include <wchar.h>
#endif

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_un 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 readunix (char *, char *, int);
static int writeunix (char *, char *, int);

static enum clnt_stat clntunix_call (CLIENT *, u_long, xdrproc_t, caddr_t,
				    xdrproc_t, caddr_t, struct timeval);
static void clntunix_abort (void);
static void clntunix_geterr (CLIENT *, struct rpc_err *);
static bool_t clntunix_freeres (CLIENT *, xdrproc_t, caddr_t);
static bool_t clntunix_control (CLIENT *, int, char *);
static void clntunix_destroy (CLIENT *);

static struct clnt_ops unix_ops =
{
  clntunix_call,
  clntunix_abort,
  clntunix_geterr,
  clntunix_freeres,
  clntunix_destroy,
  clntunix_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 *
clntunix_create (struct sockaddr_un *raddr, u_long prog, u_long vers,
		 int *sockp, u_int sendsz, u_int recvsz)
{
  CLIENT *h;
  struct ct_data *ct = (struct ct_data *) mem_alloc (sizeof (*ct));
  struct rpc_msg call_msg;
  int len;

  h = (CLIENT *) mem_alloc (sizeof (*h));
  if (h == NULL || ct == NULL)
    {
      struct rpc_createerr *ce = &get_rpc_createerr ();
#ifdef USE_IN_LIBIO
      if (_IO_fwide (stderr, 0) > 0)
	(void) __fwprintf (stderr, L"%s",
			   _("clntunix_create: out of memory\n"));
      else
#endif
	(void) fputs (_("clntunix_create: out of memory\n"), stderr);
      ce->cf_stat = RPC_SYSTEMERROR;
      ce->cf_error.re_errno = ENOMEM;
      goto fooy;
    }

  /*
   * If no socket given, open one
   */
  if (*sockp < 0)
    {
      *sockp = socket (AF_UNIX, SOCK_STREAM, 0);
      len = strlen (raddr->sun_path) + sizeof (raddr->sun_family) + 1;
      if (*sockp < 0
	  || connect (*sockp, (struct sockaddr *) raddr, len) < 0)
	{
	  struct rpc_createerr *ce = &get_rpc_createerr ();
	  ce->cf_stat = RPC_SYSTEMERROR;
	  ce->cf_error.re_errno = errno;
	  if (*sockp != -1)
	    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)
	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, readunix, writeunix);
  h->cl_ops = &unix_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;
}

static enum clnt_stat
clntunix_call (h, proc, xdr_args, args_ptr, xdr_results, results_ptr, timeout)
     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;
  u_int32_t *msg_x_id = (u_int32_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 (reply_msg.rm_xid == 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;