sunrpc/clnt_udp.c

/* @(#)clnt_udp.c	2.2 88/08/01 4.0 RPCSRC */
/*
 * 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
 */
#if !defined(lint) && defined(SCCSIDS)
static char sccsid[] = "@(#)clnt_udp.c 1.39 87/08/11 Copyr 1984 Sun Micro";
#endif

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

#include <stdio.h>
#include <unistd.h>
#include <rpc/rpc.h>
#include <rpc/xdr.h>
#include <rpc/clnt.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netdb.h>
#include <errno.h>
#include <rpc/pmap_clnt.h>

extern bool_t xdr_opaque_auth (XDR *, struct opaque_auth *);

/*
 * UDP bases client side rpc operations
 */
static enum clnt_stat clntudp_call (CLIENT *, u_long, xdrproc_t, caddr_t,
				    xdrproc_t, caddr_t, struct timeval);
static void clntudp_abort (void);
static void clntudp_geterr (CLIENT *, struct rpc_err *);
static bool_t clntudp_freeres (CLIENT *, xdrproc_t, caddr_t);
static bool_t clntudp_control (CLIENT *, int, char *);
static void clntudp_destroy (CLIENT *);

static struct clnt_ops udp_ops =
{
  clntudp_call,
  clntudp_abort,
  clntudp_geterr,
  clntudp_freeres,
  clntudp_destroy,
  clntudp_control
};

/*
 * Private data kept per client handle
 */
struct cu_data
  {
    int cu_sock;
    bool_t cu_closeit;
    struct sockaddr_in cu_raddr;
    int cu_rlen;
    struct timeval cu_wait;
    struct timeval cu_total;
    struct rpc_err cu_error;
    XDR cu_outxdrs;
    u_int cu_xdrpos;
    u_int cu_sendsz;
    char *cu_outbuf;
    u_int cu_recvsz;
    char cu_inbuf[1];
  };

/*
 * Create a UDP based client handle.
 * If *sockp<0, *sockp is set to a newly created UPD socket.
 * If raddr->sin_port is 0 a binder on the remote machine
 * is consulted for the correct port number.
 * NB: It is the clients responsibility to close *sockp.
 * NB: The rpch->cl_auth is initialized to null authentication.
 *     Caller may wish to set this something more useful.
 *
 * wait is the amount of time used between retransmitting a call if
 * no response has been heard; retransmission occurs until the actual
 * rpc call times out.
 *
 * sendsz and recvsz are the maximum allowable packet sizes that can be
 * sent and received.
 */
CLIENT *
clntudp_bufcreate (raddr, program, version, wait, sockp, sendsz, recvsz)
     struct sockaddr_in *raddr;
     u_long program;
     u_long version;
     struct timeval wait;
     int *sockp;
     u_int sendsz;
     u_int recvsz;
{
  CLIENT *cl;
  struct cu_data *cu = NULL;
  struct timeval now;
  struct rpc_msg call_msg;

  cl = (CLIENT *) mem_alloc (sizeof (CLIENT));
  if (cl == NULL)
    {
      (void) fprintf (stderr, _("clntudp_create: out of memory\n"));
      rpc_createerr.cf_stat = RPC_SYSTEMERROR;
      rpc_createerr.cf_error.re_errno = errno;
      goto fooy;
    }
  sendsz = ((sendsz + 3) / 4) * 4;
  recvsz = ((recvsz + 3) / 4) * 4;
  cu = (struct cu_data *) mem_alloc (sizeof (*cu) + sendsz + recvsz);
  if (cu == NULL)
    {
      (void) fprintf (stderr, _("clntudp_create: out of memory\n"));
      rpc_createerr.cf_stat = RPC_SYSTEMERROR;
      rpc_createerr.cf_error.re_errno = errno;
      goto fooy;
    }
  cu->cu_outbuf = &cu->cu_inbuf[recvsz];

  (void) gettimeofday (&now, (struct timezone *) 0);
  if (raddr->sin_port == 0)
    {
      u_short port;
      if ((port =
	   pmap_getport (raddr, program, version, IPPROTO_UDP)) == 0)
	{
	  goto fooy;
	}
      raddr->sin_port = htons (port);
    }
  cl->cl_ops = &udp_ops;
  cl->cl_private = (caddr_t) cu;
  cu->cu_raddr = *raddr;
  cu->cu_rlen = sizeof (cu->cu_raddr);
  cu->cu_wait = wait;
  cu->cu_total.tv_sec = -1;
  cu->cu_total.tv_usec = -1;
  cu->cu_sendsz = sendsz;
  cu->cu_recvsz = recvsz;
  call_msg.rm_xid = getpid () ^ now.tv_sec ^ now.tv_usec;
  call_msg.rm_direction = CALL;
  call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
  call_msg.rm_call.cb_prog = program;
  call_msg.rm_call.cb_vers = version;
  xdrmem_create (&(cu->cu_outxdrs), cu->cu_outbuf,
		 sendsz, XDR_ENCODE);
  if (!xdr_callhdr (&(cu->cu_outxdrs), &call_msg))
    {
      goto fooy;
    }
  cu->cu_xdrpos = XDR_GETPOS (&(cu->cu_outxdrs));
  if (*sockp < 0)
    {
      int dontblock = 1;

      *sockp = socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP);
      if (*sockp < 0)
	{
	  rpc_createerr.cf_stat = RPC_SYSTEMERROR;
	  rpc_createerr.cf_error.re_errno = errno;
	  goto fooy;
	}
      /* attempt to bind to prov port */
      (void) bindresvport (*sockp, (struct sockaddr_in *) 0);
      /* the sockets rpc controls are non-blocking */
      (void) ioctl (*sockp, FIONBIO, (char *) &dontblock);
      cu->cu_closeit = TRUE;
    }
  else
    {
      cu->cu_closeit = FALSE;
    }
  cu->cu_sock = *sockp;
  cl->cl_auth = authnone_create ();
  return cl;
fooy:
  if (cu)
    mem_free ((caddr_t) cu, sizeof (*cu) + sendsz + recvsz);
  if (cl)
    mem_free ((caddr_t) cl, sizeof (CLIENT));
  return (CLIENT *) NULL;
}

CLIENT *
clntudp_create (raddr, program, version, wait, sockp)
     struct sockaddr_in *raddr;
     u_long program;
     u_long version;
     struct timeval wait;
     int *sockp;
{

  return clntudp_bufcreate (raddr, program, version, wait, sockp,
			    UDPMSGSIZE, UDPMSGSIZE);
}

static enum clnt_stat
clntudp_call (cl, proc, xargs, argsp, xresults, resultsp, utimeout)
     CLIENT *cl;	/* client handle */
     u_long proc;		/* procedure number */
     xdrproc_t xargs;		/* xdr routine for args */
     caddr_t argsp;		/* pointer to args */
     xdrproc_t xresults;	/* xdr routine for results */
     caddr_t resultsp;		/* pointer to results */
     struct timeval utimeout;	/* seconds to wait before giving up */
{
  struct cu_data *cu = (struct cu_data *) cl->cl_private;
  XDR *xdrs;
  int outlen;
  int inlen;
  size_t fromlen;
#ifdef FD_SETSIZE
  fd_set readfds;
  fd_set mask;
#else
  int readfds;
  int mask;
#endif /* def FD_SETSIZE */
  struct sockaddr_in from;
  struct rpc_msg reply_msg;
  XDR reply_xdrs;
  struct timeval time_waited;
  bool_t ok;
  int nrefreshes = 2;		/* number of times to refresh cred */
  struct timeval timeout;

  if (cu->cu_total.tv_usec == -1)
    {
      timeout = utimeout;	/* use supplied timeout */
    }
  else
    {
      timeout = cu->cu_total;	/* use default timeout */
    }

  time_waited.tv_sec = 0;
  time_waited.tv_usec = 0;
call_again:
  xdrs = &(cu->cu_outxdrs);
  xdrs->x_op = XDR_ENCODE;
  XDR_SETPOS (xdrs, cu->cu_xdrpos);
  /*
   * the transaction is the first thing in the out buffer
   */
  (*(u_short *) (cu->cu_outbuf))++;
  if ((!XDR_PUTLONG (xdrs, (long *) &proc)) ||
      (!AUTH_MARSHALL (cl->cl_auth, xdrs)) ||
      (!(*xargs) (xdrs, argsp)))
    return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
  outlen = (int) XDR_GETPOS (xdrs);

send_again:
  if (sendto (cu->cu_sock, cu->cu_outbuf, outlen, 0,
	      (struct sockaddr *) &(cu->cu_raddr), cu->cu_rlen)
      != outlen)
    {
      cu->cu_error.re_errno = errno;
      return (cu->cu_error.re_status = RPC_CANTSEND);
    }

  /*
   * Hack to provide rpc-based message passing
   */
  if (timeout.tv_sec == 0 && timeout.tv_usec == 0)
    {
      return (cu->cu_error.re_status = RPC_TIMEDOUT);
    }
  /*
   * sub-optimal code appears here because we have
   * some clock time to spare while the packets are in flight.
   * (We assume that this is actually only executed once.)
   */
  reply_msg.acpted_rply.ar_verf = _null_auth;
  reply_msg.acpted_rply.ar_results.where = resultsp;
  reply_msg.acpted_rply.ar_results.proc = xresults;
#ifdef FD_SETSIZE
  FD_ZERO (&mask);
  FD_SET (cu->cu_sock, &mask);
#else
  mask = 1 << cu->cu_sock;
#endif /* def FD_SETSIZE */
  for (;;)
    {
      struct timeval timeout = cu->cu_wait;
      readfds = mask;
      switch (select (_rpc_dtablesize (), &readfds, (fd_set*) NULL,
		      (fd_set*) NULL, &timeout))
	{

	case 0:
	  time_waited.tv_sec += cu->cu_wait.tv_sec;
	  time_waited.tv_usec += cu->cu_wait.tv_usec;
	  while (time_waited.tv_usec >= 1000000)
	    {
	      time_waited.tv_sec++;
	      time_waited.tv_usec -= 1000000;
	    }
	  if ((time_waited.tv_sec < timeout.tv_sec) ||
	      ((time_waited.tv_sec == timeout.tv_sec) &&
	       (time_waited.tv_usec < timeout.tv_usec)))
	    goto send_again;
	  return (cu->cu_error.re_status = RPC_TIMEDOUT);

	  /*
	   * buggy in other cases because time_waited is not being
	   * updated.
	   */
	case -1:
	  if (errno == EINTR)
	    continue;
	  cu->cu_error.re_errno = errno;
	  return (cu->cu_error.re_status = RPC_CANTRECV);
	}
      do
	{
	  fromlen = sizeof (struct sockaddr);
	  inlen = recvfrom (cu->cu_sock, cu->cu_inbuf,
			    (int) cu->cu_recvsz, 0,
			    (struct sockaddr *) &from, &fromlen);
	}
      while (inlen < 0 && errno == EINTR);
      if (inlen < 0)
	{
	  if (errno == EWOULDBLOCK)
	    continue;
	  cu->cu_error.re_errno = errno;
	  return (cu->cu_error.re_status = RPC_CANTRECV);
	}
      if (inlen < 4)
	continue;
      /* see if reply transaction id matches sent id */
      if (*((u_int32_t *) (cu->cu_inbuf)) != *((u_int32_t *) (cu->cu_outbuf)))
	continue;
      /* we now assume we have the proper reply */
      break;
    }

  /*
   * now decode and validate the response
   */
  xdrmem_create (&reply_xdrs, cu->cu_inbuf, (u_int) inlen, XDR_DECODE);
  ok = xdr_replymsg (&reply_xdrs, &reply_msg);
  /* XDR_DESTROY(&reply_xdrs);  save a few cycles on noop destroy */
  if (ok)
    {
      _seterr_reply (&reply_msg, &(cu->cu_error));
      if (cu->cu_error.re_status == RPC_SUCCESS)
	{
	  if (!AUTH_VALIDATE (cl->cl_auth,
			      &reply_msg.acpted_rply.ar_verf))
	    {
	      cu->cu_error.re_status = RPC_AUTHERROR;
	      cu->cu_error.re_why = AUTH_INVALIDRESP;
	    }
	  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 (nrefreshes > 0 && AUTH_REFRESH (cl->cl_auth))
	    {
	      nrefreshes--;
	      goto call_again;
	    }
	}			/* end of unsuccessful completion */
    }				/* end of valid reply message */
  else
    {
      cu->cu_error.re_status = RPC_CANTDECODERES;
    }
  return cu->cu_error.re_status;
}

static void
clntudp_geterr (CLIENT *cl, struct rpc_err *errp)
{
  struct cu_data *cu = (struct cu_data *) cl->cl_private;

  *errp = cu->cu_error;
}


static bool_t
clntudp_freeres (CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr)
{
  struct cu_data *cu = (struct cu_data *) cl->cl_private;
  XDR *xdrs = &(cu->cu_outxdrs);

  xdrs->x_op = XDR_FREE;
  return (*xdr_res) (xdrs, res_ptr);
}

static void
clntudp_abort (void)
{
}

static bool_t
clntudp_control (CLIENT *cl, int request, char *info)
{
  struct cu_data *cu = (struct cu_data *) cl->cl_private;

  switch (request)
    {
    case CLSET_TIMEOUT:
      cu->cu_total = *(struct timeval *) info;
      break;
    case CLGET_TIMEOUT:
      *(struct timeval *) info = cu->cu_total;
      break;
    case CLSET_RETRY_TIMEOUT:
      cu->cu_wait = *(struct timeval *) info;
      break;
    case CLGET_RETRY_TIMEOUT:
      *(struct timeval *) info = cu->cu_wait;
      break;
    case CLGET_SERVER_ADDR:
      *(struct sockaddr_in *) info = cu->cu_raddr;
      break;
    default:
      return FALSE;
    }
  return TRUE;
}

static void
clntudp_destroy (CLIENT *cl)
{
  struct cu_data *cu = (struct cu_data *) cl->cl_private;

  if (cu->cu_closeit)
    {
      (void) close (cu->cu_sock);
    }
  XDR_DESTROY (&(cu->cu_outxdrs));
  mem_free ((caddr_t) cu, (sizeof (*cu) + cu->cu_sendsz + cu->cu_recvsz));
  mem_free ((caddr_t) cl, sizeof (CLIENT));
}