/* $Id: rpc.c,v 1.3 2001/12/24 01:09:06 sybalsky Exp $ (C) Copyright Venue, All Rights Reserved  */

/************************************************************************/
/*									*/
/*	(C) Copyright 1989-99 Venue. All Rights Reserved.		*/
/*	Manufactured in the United States of America.			*/
/*									*/
/************************************************************************/

#include "version.h"

/************************************************************************/
/************************************************************************/
/*									*/
/*									*/
/*									*/
/*									*/
/*									*/
/************************************************************************/

#ifndef DOS
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/select.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <netdb.h>
#include <errno.h>
#include <string.h> /* for memset/memcpy */
#endif              /* DOS */
#include "lispemul.h"
#include "lispmap.h"
#include "lsptypes.h"
#include "lspglob.h"
#include "emlglob.h"
#include "adr68k.h"
#include "arith.h"
#include "locfile.h"

#include "rpcdefs.h"
#include "commondefs.h"

#define MAX_HOSTNAME_LENGTH 100
#define UDP_DATA_BLOCK_SIZE 1000

LispPTR rpc(LispPTR *args)
{
#ifndef DOS
  /* Arguments are:
     args[0]:Destination Address; hostname or internet address are both supported.
     args[1]:Remote port for this program.
     args[2]:Argument block pointer.
     args[3]:Result Block pointer.
     args[4]:Milliseconds before timeout
     args[5]:Milliseconds between tries
     args[6]:Argument block length
     */
  char hostname[MAX_HOSTNAME_LENGTH];
  struct hostent *hp;
  struct sockaddr_in sin, sin1, from;
  char *outbuf, *inbuf, *destaddr;
  int s, msec_until_timeout, msec_between_tries, out_length;
  int received;
  int port;
  int dest;
  unsigned fromlen;
  fd_set read_descriptors;
  struct timeval pertry_timeout, total_timeout, time_waited;

  /* Set timeout */
  /* CONVERT FROM LISP TO C TYPES */
  dest = GetTypeNumber(args[0]);

  if ((dest == TYPE_FIXP) || (dest == TYPE_SMALLP)) {
    N_GETNUMBER(args[0], dest, handle_error);
    destaddr = (char *)&dest;
    hp = gethostbyaddr(destaddr, sizeof(struct in_addr), AF_INET);
  } else {
    /* Convert Hostname */
    LispStringToCString(args[0], hostname, MAX_HOSTNAME_LENGTH);
    hp = gethostbyname(hostname);
  }

  N_GETNUMBER(args[1], port, handle_error);

  /* Translate the buffer pointer into C pointers */
  outbuf = (char *)(NativeAligned2FromLAddr(args[2]));
  inbuf = (char *)(NativeAligned2FromLAddr(args[3]));

  N_GETNUMBER(args[4], msec_until_timeout, handle_error);

  N_GETNUMBER(args[5], msec_between_tries, handle_error);

  N_GETNUMBER(args[6], out_length, handle_error);

  /* Convert to micro seconds */
  msec_until_timeout = msec_until_timeout * 1000;
  msec_between_tries = msec_between_tries * 1000;

  /* Set up the timeouts */
  total_timeout.tv_sec = msec_until_timeout / 1000000;
  total_timeout.tv_usec = msec_until_timeout % 1000000;
  pertry_timeout.tv_sec = msec_between_tries / 1000000;
  pertry_timeout.tv_usec = msec_between_tries % 1000000;

  /* SET UP THE SOCKET */

  /* Open the socket; Might want to make this non-blocking */
  if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) goto handle_error;

  /* The sockets that rpc controls don't block */
  fcntl(s, F_SETFL, fcntl(s, F_GETFL, 0) | O_NONBLOCK);

  memset((char *)&sin, 0, sizeof(sin));
  sin.sin_family = AF_INET;
  bind(s, (struct sockaddr *)&sin, sizeof(sin));

  /* Resolve the host address. */
  if (hp) {
    sin1.sin_family = hp->h_addrtype;
    memcpy(&sin1.sin_addr, hp->h_addr, hp->h_length);
  } else
    goto handle_error;

  /* Convert to network byte order */
  sin1.sin_port = htons((u_short)port);

  /* Send buffer out on the socket */
  if (sendto(s, outbuf, out_length, 0, (struct sockaddr *)&sin1, sizeof(sin1)) != out_length)
    goto handle_error;

  /* Set up the timers */
  time_waited.tv_sec = 0;
  time_waited.tv_usec = 0;

/* Start the waiting loop */
receive:

  /* Set the select mask */
  FD_SET(s, &read_descriptors);

  switch (
      select(32, &read_descriptors, NULL, NULL, &pertry_timeout)) {
    /* Per try timeout expired, Check the total timeout */
    case 0:
      time_waited.tv_sec += pertry_timeout.tv_sec;
      time_waited.tv_usec += pertry_timeout.tv_usec;
      while (time_waited.tv_usec >= 1000000) {
        time_waited.tv_sec++;
        time_waited.tv_usec -= 1000000;
      }
      /* If the time waited is greater than the total
       * timeout then there's an error
       */
      if ((time_waited.tv_sec > total_timeout.tv_sec) ||
          ((time_waited.tv_sec == total_timeout.tv_sec) &&
           (time_waited.tv_usec >= total_timeout.tv_usec)))
        goto handle_error;
      else
        break;

    /* An error was generated, Unless it was a system error stop */
    case -1:
      if (errno == EINTR)
        goto receive;
      else
        goto handle_error;
  }
  /* Nothing arrived for this socket, try again */
  if (!FD_ISSET(s, &read_descriptors)) goto receive;

/* Something arrived; try to get it */

getbuf:
  fromlen = sizeof(struct sockaddr);
  received = recvfrom(s, inbuf, UDP_DATA_BLOCK_SIZE, 0, (struct sockaddr *)&from, &fromlen);
  if (received < 0) switch (errno) {
      case EINTR: goto getbuf;
      case EWOULDBLOCK: goto receive;
      default: goto handle_error;
    }

  /* close the socket */
  close(s);

  /* Return TRUE */
  return (ATOM_T);

/* Return NIL; Eventually we will need to return something more informative, perhaps errno
 * would be sufficient.
 */
handle_error:
  return (NIL_PTR);
#endif /* DOS */
}