path: root/src/lib/sockio-c.c

/*
    Copyright (c) 1991-2002, The Numerical Algorithms Group Ltd.
    All rights reserved.

    Copyright (C) 2007-2008, Gabriel Dos Reis.
    All rights reserved.

    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 Numerical ALgorithms Group Ltd. 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 OWNER
    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.
*/

/* socket i/o primitives */

#include <stdio.h>
#include <stdlib.h>

#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#include <sys/time.h>
#include <string.h>
#include <signal.h>

#include "sockio.h"
#include "com.h"
#include "bsdsignal.h"

#define TotalMaxPurposes 50
#define MaxServerNumbers 100
#define accept_if_needed(purpose) \
  ( purpose_table[purpose] == NULL ? sock_accept_connection(purpose) : 1 )

/* Note that the name AF_LOCAL is more portable than AF_UNIX, but MingW
   implementation and Windows documentation don't always agree.  */

#if HAVE_AF_LOCAL
#  define OPENAXIOM_AF_LOCAL AF_LOCAL
#elif HAVE_AF_UNIX
#  define OPENAXIOM_AF_LOCAL AF_UNIX
#else
#  error "needs one of AF_LOCAL or AF_UNIX"
#endif


/* socket description of spad clients */
OPENAXIOM_EXPORT openaxiom_sio clients[MaxClients];       

/* AF_LOCAL and AF_INET sockets for server */
OPENAXIOM_EXPORT openaxiom_sio server[2];                 

/* table of dedicated socket types */
OPENAXIOM_EXPORT openaxiom_sio *purpose_table[TotalMaxPurposes]; 

/* bit mask of active sockets */
OPENAXIOM_EXPORT fd_set socket_mask;             

/* bit mask of server sockets */
OPENAXIOM_EXPORT fd_set server_mask;             

/* used to identify closed socket on SIGPIPE */
int socket_closed;              

/* spad server number used in sman */
int spad_server_number = -1;    


#include "sockio.h"

/* The function sleep() is not available under Windows.  Instead, they
   have Sleep(); with capital S, please.  Furthermore, it does not
   take argument in second, but in milliseconds, three order
   of magnitude of difference when compared to the Unix world.
   We abstract over that difference here.  */

static inline void
openaxiom_sleep(int n)
{
#ifdef __WIN32__
   Sleep(n * 1000);
#else
   sleep(n);
#endif   
}

/* Windows require some handshaking with the WinSock DLL before
   we can even think about talking about sockets. */

static void
openaxiom_load_socket_module()
{
#ifdef __WIN32__
   WSADATA wsaData;

   /* Request version 2.0 of WinSock DLL. */
   if (WSAStartup(MAKEWORD(2, 0), &wsaData) != 0) {
      perror("could not find suitable WinSock DLL.");
      exit(WSAGetLastError());
   }
   
   if (LOBYTE(wsaData.wVersion) != 2 || HIBYTE(wsaData.wVersion) != 0) {
      perror("could not find suitable WinSock DLL.");
      WSACleanup();
      exit(WSAGetLastError());
   }
#endif   
}


/* Get a socket identifier to a local server.  We take whatever protocol
   is the default for the address family in the SOCK_STREAM type.  */
static inline openaxiom_socket
openaxiom_communication_link(int family)
{
   openaxiom_load_socket_module();
   return socket(family, SOCK_STREAM, 0);
}


/* Returns 1 if SOCKET is an invalid socket.  Otherwise return 0.  */

static inline int
is_invalid_socket(const openaxiom_sio* s)
{
#ifdef __WIN32__
   return s->socket == INVALID_SOCKET;
#else
   return s->socket < 0;
#endif   
}

/* Returns 1 if SOCKET is a valid socket.  Otherwise return 0.  */

static inline int
is_valid_socket(const openaxiom_sio* s)
{
#ifdef __WIN32__
   return s->socket != INVALID_SOCKET;
#else
   return s->socket > 0;
#endif   
}


/* Because a socket on Windows platform is a not just a simple file
   descriptor as it is in the Unix world, it is invalid to use
   a socket identifier as argument for read(), or close, or
   any other file descriptor function.  Furthermore, Windows
   requires cleanup.  */

void
openaxiom_close_socket(openaxiom_socket s)
{
#ifdef __WIN32__
   shutdown(s, SD_BOTH);
   closesocket(s);
   WSACleanup();
#else
   close(s);
#endif
}  

/* It is idiomatic in the Unix/POSIX world to use the standard
   read() and write() functions on sockets.  However, in the Windows
   world, that is invalid.  Consequently, portability suggests that
   we restrict ourselves to the POSIX standard functions recv() and
   send().  */

static inline int
openaxiom_write(openaxiom_sio* s, const openaxiom_byte* buf, size_t n)
{
   return send(s->socket, buf, n, 0);
}

static inline int
openaxiom_read(openaxiom_sio* s, openaxiom_byte* buf, size_t n)
{
   return recv(s->socket, buf, n, 0);
}


/* Return 1 is the last call was cancelled. */

static inline int
openaxiom_syscall_was_cancelled(void)
{
#ifdef __WIN32__
   return WSAGetLastError() == WSAEINTR;
#else
   return errno == EINTR;
#endif
}

/* Return 1 is last connect() was refused.  */

static inline int
openaxiom_connection_refused(void)
{
#ifdef __WIN32__
   return WSAGetLastError() == WSAECONNREFUSED;
#else
   return errno == ECONNREFUSED;
#endif   
}


OPENAXIOM_EXPORT void  
sigpipe_handler(int sig)
{
  socket_closed = 1;
}

OPENAXIOM_EXPORT int 
wait_for_client_read(openaxiom_sio *sock, openaxiom_byte* buf, int buf_size,
                     const char* msg)
{
  int ret_val;
  switch(sock->purpose) {
  case SessionManager:
  case ViewportServer:
    sock_accept_connection(sock->purpose);
    ret_val = sread(purpose_table[sock->purpose], buf, buf_size, msg);
    sock->socket = 0;
    return ret_val;
  default:
    sock->socket = 0;
    return -1;
  }
}

OPENAXIOM_EXPORT int 
wait_for_client_write(openaxiom_sio* sock, const openaxiom_byte* buf,
                      int buf_size, const char* msg)
{
  int ret_val;
  switch(sock->purpose) {
  case SessionManager:
  case ViewportServer:
    sock_accept_connection(sock->purpose);
    ret_val = swrite(purpose_table[sock->purpose], buf, buf_size, msg);
    sock->socket = 0;
    return ret_val;
  default:
    sock->socket = 0;
    return -1;
  }
}

OPENAXIOM_EXPORT int 
sread(openaxiom_sio* sock, openaxiom_byte* buf, int buf_size, const char *msg)
{
  int ret_val;
  char err_msg[256];
  errno = 0;
  do {
    ret_val = openaxiom_read(sock, buf, buf_size);
  } while (ret_val == -1 && openaxiom_syscall_was_cancelled());
  if (ret_val == 0) {
    FD_CLR(sock->socket, &socket_mask);
    purpose_table[sock->purpose] = NULL;
    openaxiom_close_socket(sock->socket);
    return wait_for_client_read(sock, buf, buf_size, msg);
  }
  if (ret_val == -1) {
    if (msg) {
      sprintf(err_msg, "reading: %s", msg);
      perror(err_msg);
    }
    return -1;
  }
  return ret_val;
}

OPENAXIOM_EXPORT int 
swrite(openaxiom_sio* sock, const openaxiom_byte* buf, int buf_size,
       const char* msg)
{
  int ret_val;
  char err_msg[256];
  errno = 0;
  socket_closed = 0;
  ret_val = openaxiom_write(sock, buf, buf_size);
  if (ret_val == -1) {
    if (socket_closed) {
      FD_CLR(sock->socket, &socket_mask);
      purpose_table[sock->purpose] = NULL;
      /*      printf("   closing socket %d\n", sock->socket); */
      openaxiom_close_socket(sock->socket);
      return wait_for_client_write(sock, buf, buf_size, msg);
    } else {
      if (msg) {
        sprintf(err_msg, "writing: %s", msg);
        perror(err_msg);
      }
      return -1;
    }
  }
  return ret_val;
}

OPENAXIOM_EXPORT int 
sselect(int n,fd_set  *rd, fd_set  *wr, fd_set *ex, void *timeout)
{
  int ret_val;
  do {
    ret_val = select(n, (void *)rd, (void *)wr, (void *)ex, (struct timeval *) timeout);
  } while (ret_val == -1 && openaxiom_syscall_was_cancelled());
  return ret_val;
}

OPENAXIOM_EXPORT int 
fill_buf(openaxiom_sio *sock, openaxiom_byte* buf, int len, const char* msg)
{
  int bytes =  0, ret_val;
  while(bytes < len) {
    ret_val = sread(sock, buf + bytes, len - bytes, msg);
    if (ret_val == -1) return -1;
    bytes += ret_val;
  }
  return bytes;
}

OPENAXIOM_EXPORT int 
get_int(openaxiom_sio *sock)
{
  int val = -1, len;
  len = fill_buf(sock, (openaxiom_byte*)&val, sizeof(int), "get_int");
  if (len != sizeof(int)) {
#ifdef DEBUG
  fprintf(stderr,"get_int: caught error\n",val);
#endif
    return -1;
  }
#ifdef DEBUG
  fprintf(stderr,"get_int: received %d\n",val);
#endif
  return val;
}

OPENAXIOM_EXPORT int 
sock_get_int(int purpose)
{
  if (accept_if_needed(purpose) != -1)
    return get_int(purpose_table[purpose]);
  else return -1;
}

OPENAXIOM_EXPORT int 
get_ints(openaxiom_sio *sock, int *vals, int num)
{
  int i;
  for(i=0; i<num; i++)
    *vals++ = get_int(sock);
  return 0;
}

OPENAXIOM_EXPORT int 
sock_get_ints(int purpose, int *vals, int num)
{
  if (accept_if_needed(purpose) != -1)
    return get_ints(purpose_table[purpose], vals, num);
  return -1;
}

OPENAXIOM_EXPORT int 
send_int(openaxiom_sio *sock,int val)
{
  int ret_val;
  ret_val = swrite(sock, (const openaxiom_byte*)&val, sizeof(int), "send_int");
  if (ret_val == -1) {
    return -1;
  }
  return 0;
}

OPENAXIOM_EXPORT int 
sock_send_int(int purpose,int  val)
{
  if (accept_if_needed(purpose) != -1)
    return send_int(purpose_table[purpose], val);
  return -1;
}

OPENAXIOM_EXPORT int 
send_ints(openaxiom_sio *sock, const int *vals, int num)
{
  int i;
  for(i=0; i<num; i++)
    if (send_int(sock, *vals++) == -1)
      return -1;
  return 0;
}

OPENAXIOM_EXPORT int 
sock_send_ints(int purpose, const int *vals, int num)
{
  if (accept_if_needed(purpose) != -1)
    return send_ints(purpose_table[purpose], vals, num);
  return -1;
}

OPENAXIOM_EXPORT int 
send_string_len(openaxiom_sio *sock, const char *str,int len)
{
  int val;
  if (len > 1023) {
    char *buf;
    buf = malloc(len+1);
    strncpy(buf,str,len);
    buf[len]='\0';
    send_int(sock,len+1);
    val = swrite(sock, (const openaxiom_byte*) buf, len+1, "send_string_len");
    free(buf);
  } else {
    static char buf[1024];
    strncpy(buf, str, len);
    buf[len] = '\0';
    send_int(sock, len+1);
    val = swrite(sock, (const openaxiom_byte*) buf, len+1, "send_string_len");
  }
  if (val == -1) {
    return -1;
  }
  return 0;
}

OPENAXIOM_EXPORT int 
send_string(openaxiom_sio* sock, const char* str)
{
  int val, len = strlen(str);
  send_int(sock, len+1);
  val = swrite(sock, (const openaxiom_byte*) str, len+1, "send_string");
  if (val == -1) {
    return -1;
  }
  return 0;
}


OPENAXIOM_EXPORT int 
sock_send_string(int purpose, const char *str)
{
  if (accept_if_needed(purpose) != -1)
    return send_string(purpose_table[purpose], str);
  return -1;
}

OPENAXIOM_EXPORT int 
sock_send_string_len(int purpose, const char* str, int len)
{
  if (accept_if_needed(purpose) != -1)
    return send_string_len(purpose_table[purpose], str, len);
  return -1;
}

OPENAXIOM_EXPORT int 
send_strings(openaxiom_sio *sock, const char** vals, int num)
{
  int i;
  for(i=0; i<num; i++)
    if (send_string(sock, *vals++) == -1)
      return -1;
  return 0;
}

OPENAXIOM_EXPORT int 
sock_send_strings(int purpose, const char**vals, int num)
{
  if (accept_if_needed(purpose) != -1)
    return send_strings(purpose_table[purpose], vals, num);
  return -1;
}

OPENAXIOM_EXPORT char *
get_string(openaxiom_sio *sock)
{
  int val, len;
  char *buf;
  len = get_int(sock);
  if (len <0) return NULL;
  buf = malloc(len*sizeof(char));
  val = fill_buf(sock, (openaxiom_byte*) buf, len, "get_string");
  if (val == -1){
        free(buf);
        return NULL;
        }
#ifdef DEBUG
  fprintf(stderr,"get_string: received \"%s\" \n",buf);
#endif
  return buf;
}

OPENAXIOM_EXPORT char *
sock_get_string(int purpose)
{
  if (accept_if_needed(purpose) != -1)
    return get_string(purpose_table[purpose]);
  else return NULL;
}


OPENAXIOM_EXPORT char *
get_string_buf(openaxiom_sio *sock, char *buf, int buf_len)
{
   int nbytes_read;
   int nbytes_to_read;
   if(sock->nbytes_pending == 0)
      sock->nbytes_pending = get_int(sock);
   nbytes_to_read = sock->nbytes_pending > buf_len
      ? buf_len
      : sock->nbytes_pending;
   nbytes_read = fill_buf(sock, (openaxiom_byte*)buf, nbytes_to_read,
                          "get_string_buf");
   if (nbytes_read == -1) {
      sock->nbytes_pending = 0;
      return NULL;
   }
   sock->nbytes_pending -= nbytes_read;
   return sock->nbytes_pending == 0 ? NULL : buf;
}

OPENAXIOM_EXPORT char *
sock_get_string_buf(int purpose, char* buf, int buf_len)
{
  if (accept_if_needed(purpose) != -1)
    return get_string_buf(purpose_table[purpose], buf, buf_len);
  return NULL;
}

OPENAXIOM_EXPORT int 
get_strings(openaxiom_sio *sock, char** vals,int num)
{
  int i;
  for(i=0; i<num; i++)
    *vals++ = get_string(sock);
  return 0;
}

OPENAXIOM_EXPORT int 
sock_get_strings(int purpose, char** vals, int num)
{
  if (accept_if_needed(purpose) != -1)
    return get_strings(purpose_table[purpose], vals, num);
  return -1;
}

OPENAXIOM_EXPORT int 
send_float(openaxiom_sio *sock, double num)
{
  int val;
  val = swrite(sock, (const openaxiom_byte*)&num, sizeof(double),"send_float");
  if (val == -1) {
    return -1;
  }
  return 0;
}

OPENAXIOM_EXPORT int 
sock_send_float(int purpose, double num)
{
  if (accept_if_needed(purpose) != -1)
    return send_float(purpose_table[purpose], num);
  return -1;
}

OPENAXIOM_EXPORT int 
send_sfloats(openaxiom_sio *sock, const float *vals,int  num)
{
  int i;
  for(i=0; i<num; i++)
    if (send_float(sock, (double) *vals++) == -1)
      return -1;
  return 0;
}

OPENAXIOM_EXPORT int 
sock_send_sfloats(int purpose, const float* vals, int num)
{
  if (accept_if_needed(purpose) != -1)
    return send_sfloats(purpose_table[purpose], vals, num);
  return -1;
}

OPENAXIOM_EXPORT int 
send_floats(openaxiom_sio *sock, const double *vals, int num)
{
  int i;
  for(i=0; i<num; i++)
    if (send_float(sock, *vals++) == -1)
      return -1;
  return 0;
}

OPENAXIOM_EXPORT int 
sock_send_floats(int purpose, const double  *vals, int num)
{
  if (accept_if_needed(purpose) != -1)
    return send_floats(purpose_table[purpose], vals, num);
  return -1;
}

OPENAXIOM_EXPORT double 
get_float(openaxiom_sio *sock)
{
  int val;
  double num = -1.0;
  val = fill_buf(sock, (openaxiom_byte*)&num, sizeof(double), "get_float");
#ifdef DEBUG
  fprintf(stderr,"get_float: received %f\n",num);
#endif
  return num;
}

OPENAXIOM_EXPORT double 
sock_get_float(int purpose)
{
  if (accept_if_needed(purpose) != -1)
    return get_float(purpose_table[purpose]);
  else return 0.0;
}

OPENAXIOM_EXPORT int 
get_sfloats(openaxiom_sio *sock, float *vals, int num)
{
  int i;
  for(i=0; i<num; i++)
    *vals++ = (float) get_float(sock);
  return 0;
}


OPENAXIOM_EXPORT int 
sock_get_sfloats(int purpose,float * vals, int num)
{
  if (accept_if_needed(purpose) != -1)
    return get_sfloats(purpose_table[purpose], vals, num);
  return -1;
}

OPENAXIOM_EXPORT int 
get_floats(openaxiom_sio *sock,double *vals,int num)
{
  int i;
  for(i=0; i<num; i++)
    *vals++ = get_float(sock);
  return 0;
}


OPENAXIOM_EXPORT int 
sock_get_floats(int purpose, double *vals, int num)
{
  if (accept_if_needed(purpose) != -1)
    return get_floats(purpose_table[purpose], vals, num);
  return -1;
}

OPENAXIOM_EXPORT int 
wait_for_client_kill(openaxiom_sio *sock, int sig)
{
  int ret_val;
  switch(sock->purpose) {
  case SessionManager:
  case ViewportServer:
    sock_accept_connection(sock->purpose);
    ret_val = send_signal(purpose_table[sock->purpose], sig);
    sock->socket = 0;
    return ret_val;
  default:
    sock->socket = 0;
    return -1;
  }
}


OPENAXIOM_EXPORT int 
sock_get_remote_fd(int purpose)
{
  if (accept_if_needed(purpose) != -1)
    return purpose_table[purpose]->remote;
  return -1;
}

OPENAXIOM_EXPORT int 
send_signal(openaxiom_sio *sock, int sig)
{
  int ret_val;
#if HAVE_DECL_KILL
  ret_val = kill(sock->pid, sig);
#else
  ret_val = raise(sig);
#endif  
  if (ret_val == -1 && errno == ESRCH) {
    FD_CLR(sock->socket, &socket_mask);
    purpose_table[sock->purpose] = NULL;
/*    printf("   closing socket %d\n", sock->socket); */
    openaxiom_close_socket(sock->socket);
    return wait_for_client_kill(sock, sig);
  }
  return ret_val;
}

OPENAXIOM_EXPORT int 
sock_send_signal(int purpose,int  sig)
{
  if (accept_if_needed(purpose) != -1)
    return send_signal(purpose_table[purpose], sig);
  return -1;
}

OPENAXIOM_EXPORT int 
send_wakeup(openaxiom_sio *sock)
{
#ifdef SIGUSR1   
  return send_signal(sock, SIGUSR1);
#else
  return -1;
#endif  
}

OPENAXIOM_EXPORT int 
sock_send_wakeup(int purpose)
{
  if (accept_if_needed(purpose) != -1)
    return send_wakeup(purpose_table[purpose]);
  return -1;
}

OPENAXIOM_EXPORT openaxiom_sio *
connect_to_local_server_new(char *server_name, int purpose, int time_out)
{
  int max_con=(time_out == 0 ? 1000000 : time_out), i, code=-1;
  openaxiom_sio *sock;
  char name[256];

  make_server_name(name, server_name);
  sock = (openaxiom_sio *) calloc(sizeof(openaxiom_sio), 1);
  if (sock == NULL) {
    perror("allocating socket space");
    return NULL;
  }

  sock->socket = openaxiom_communication_link(OPENAXIOM_AF_LOCAL);
  if (is_invalid_socket(sock)) {
    perror("opening client socket");
    free(sock);
    return NULL;
  }

  memset(server[1].addr.u_addr.sa_data, 0,
         sizeof(server[1].addr.u_addr.sa_data));
  sock->addr.u_addr.sa_family = OPENAXIOM_AF_LOCAL;
  strcpy(sock->addr.u_addr.sa_data, name);
  for(i=0; i<max_con; i++) {
    code = connect(sock->socket, &sock->addr.u_addr,
                   sizeof(sock->addr.u_addr));
    if (code == -1) {
      if (errno != ENOENT && !openaxiom_connection_refused()) {
        perror("connecting server stream socket");
        return NULL;
      } else {
        if (i != max_con - 1)
           openaxiom_sleep(1);
        continue;
      }
    } else break;
  }

  if (code == -1) {
    return NULL;
  }

  send_int(sock, getpid());
  send_int(sock, purpose);
  send_int(sock, sock->socket);
  sock->pid = get_int(sock);
  sock->remote = get_int(sock);
  return sock;
}

OPENAXIOM_EXPORT openaxiom_sio *
connect_to_local_server(char *server_name, int purpose, int time_out)
{
  int max_con=(time_out == 0 ? 1000000 : time_out), i, code=-1;
  openaxiom_sio *sock;
  char name[256];

  make_server_name(name, server_name);
  sock = (openaxiom_sio *) calloc(sizeof(openaxiom_sio), 1);
  if (sock == NULL) {
    perror("allocating socket space");
    return NULL;
  }

  sock->purpose = purpose;
  /* create the socket */
  sock->socket = openaxiom_communication_link(OPENAXIOM_AF_LOCAL);
  if (is_invalid_socket(sock)) {
    perror("opening client socket");
    free(sock);
    return NULL;
  }
  /* connect socket using name specified in command line */
  memset(server[1].addr.u_addr.sa_data, 0,
         sizeof(server[1].addr.u_addr.sa_data));
  sock->addr.u_addr.sa_family = OPENAXIOM_AF_LOCAL;
  strcpy(sock->addr.u_addr.sa_data, name);
  for(i=0; i<max_con; i++) {
    code = connect(sock->socket, &sock->addr.u_addr,
                   sizeof(sock->addr.u_addr));
    if (code == -1) {
      if (errno != ENOENT && !openaxiom_connection_refused()) {
        perror("connecting server stream socket");
        return NULL;
      } else {
        if (i != max_con - 1)
           openaxiom_sleep(1);
        continue;
      }
    } else break;
  }
  if (code == -1) {
    return NULL;
  }
  send_int(sock, getpid());
  send_int(sock, sock->purpose);
  send_int(sock, sock->socket);
  sock->pid = get_int(sock);
/*  fprintf(stderr, "Got int form socket\n"); */
  sock->remote = get_int(sock);
  return sock;
}

/* act as terminal session for sock connected to stdin and stdout of another
   process */
OPENAXIOM_EXPORT void 
remote_stdio(openaxiom_sio *sock)
{
  char buf[1024];
  fd_set rd;
  int len;
  while (1) {
    FD_ZERO(&rd);
    FD_SET(sock->socket,&rd);
    FD_SET(0, &rd);
    len = sselect(FD_SETSIZE, (fd_set *)&rd, (fd_set *)0, (fd_set *)0, NULL);
    if (len == -1) {
      perror("stdio select");
      return;
    }
    if (FD_ISSET(0, &rd)) {
      fgets(buf,1024,stdin);
      len = strlen(buf);
      swrite(sock, (const openaxiom_byte*)buf, len, "remote_stdio::write");
    }
    if (FD_ISSET(sock->socket, &rd)) {
      len = sread(sock, (openaxiom_byte*)buf, 1024, "remote_stdio::read");
      if (len == -1)
        return;
      else {
        *(buf + len) = '\0';
        fputs(buf, stdout);
        fflush(stdout);
      }
    }
  }
}

/* initialize the table of dedicated sockets */
OPENAXIOM_EXPORT void 
init_purpose_table(void)
{
  int i;
  for(i=0; i<TotalMaxPurposes; i++) {
    purpose_table[i] = NULL;
  }
}


OPENAXIOM_EXPORT int 
make_server_number(void)
{
  spad_server_number = getpid();
  return spad_server_number;
}

OPENAXIOM_EXPORT void 
close_socket(openaxiom_socket socket_num, const char *name)
{
  openaxiom_close_socket(socket_num);
#ifndef RTplatform
  unlink(name);
#endif
}

OPENAXIOM_EXPORT int 
make_server_name(char *name, const char* base)
{
  char *num;
  if (spad_server_number != -1) {
    sprintf(name, "%s%d", base, spad_server_number);
    return 0;
  }
  num = getenv("SPADNUM");
  if (num == NULL) {
/*    fprintf(stderr,
      "\n(AXIOM Sockets) The AXIOM server number is undefined.\n");
*/
    return -1;
  }
  sprintf(name, "%s%s", base, num);
  return 0;
}

/* client Spad server sockets.  Two sockets are created: server[0]
   is the internet server socket, and server[1] is a local domain socket. */
OPENAXIOM_EXPORT int 
open_server(const char* server_name)
{
  char *s, name[256];

  init_socks();
#ifdef SIGPIPE
  bsdSignal(SIGPIPE, sigpipe_handler,RestartSystemCalls);
#endif  
  if (make_server_name(name, server_name) == -1)
    return -2;
  /* create the socket internet socket */
  server[0].socket = 0;
/*  server[0].socket = openaxiom_communication_link(AF_INET);
  if (is_invalid_socket(&server[0])) {
    server[0].socket = 0;
  } else {
    server[0].addr.i_addr.sin_family = AF_INET;
    server[0].addr.i_addr.sin_addr.s_addr = INADDR_ANY;
    server[0].addr.i_addr.sin_port = 0;
    if (bind(server[0].socket, &server[0].addr.i_addr,
             sizeof(server[0].addr.i_addr))) {
      perror("binding INET stream socket");
      server[0].socket = 0;
      return -1;
    }
    length = sizeof(server[0].addr.i_addr);
    if (getsockname(server[0].socket, &server[0].addr.i_addr, &length)) {
      perror("getting INET server socket name");
      server[0].socket = 0;
      return -1;
    }
    server_port = ntohs(server[0].addr.i_addr.sin_port);
    FD_SET(server[0].socket, &socket_mask);
    FD_SET(server[0].socket, &server_mask);
    listen(server[0].socket,5);
  } */
  /* Next create the local domain socket */
  server[1].socket = openaxiom_communication_link(OPENAXIOM_AF_LOCAL);
  if (is_invalid_socket(&server[1])) {
    perror("opening local server socket");
    server[1].socket = 0;
    return -2;
  } else {
    server[1].addr.u_addr.sa_family = OPENAXIOM_AF_LOCAL;
    memset(server[1].addr.u_addr.sa_data, 0,
           sizeof(server[1].addr.u_addr.sa_data));
    strcpy(server[1].addr.u_addr.sa_data, name);
    if (bind(server[1].socket, &server[1].addr.u_addr,
             sizeof(server[1].addr.u_addr))) {
      perror("binding local server socket");
      server[1].socket = 0;
      return -2;
    }
    FD_SET(server[1].socket, &socket_mask);
    FD_SET(server[1].socket, &server_mask);
    listen(server[1].socket, 5);
  }
  s = getenv("SPADSERVER");
  if (s == NULL) {
/*    fprintf(stderr, "Not a spad server system\n"); */
    return -1;
  }
  return 0;
}

OPENAXIOM_EXPORT int 
accept_connection(openaxiom_sio *sock)
{
  int client;
  for(client=0; client<MaxClients && clients[client].socket != 0; client++);
  if (client == MaxClients) {
    printf("Ran out of client openaxiom_sio structures\n");
    return -1;
  }
  clients[client].socket = accept(sock->socket, 0, 0);
  if (is_invalid_socket(&clients[client])) {
    perror("accept_connection");
    clients[client].socket = 0;
    return -1;
  }
  FD_SET(clients[client].socket, &socket_mask);
  get_socket_type(clients+client);
  return clients[client].purpose;
}

/* reads a the socket purpose declaration for classification */
OPENAXIOM_EXPORT void 
get_socket_type(openaxiom_sio *sock)
{
  sock->pid = get_int(sock);
  sock->purpose = get_int(sock);
  sock->remote = get_int(sock);
  send_int(sock, getpid());
  send_int(sock, sock->socket);
  purpose_table[sock->purpose] = sock;
  switch (sock->purpose) {
  case SessionManager:
    break;
  case ViewportServer:
    break;
  case MenuServer:
    break;
  case SessionIO:
/*    redirect_stdio(sock); */
    break;
  }
}

OPENAXIOM_EXPORT int 
sock_accept_connection(int purpose)
{
  fd_set rd;
  int ret_val, i, p;
  if (getenv("SPADNUM") == NULL) return -1;
  while (1) {
    rd = server_mask;
    ret_val = sselect(FD_SETSIZE, (fd_set *)&rd, (fd_set *)0, (fd_set *)0, NULL);
    if (ret_val == -1) {
      /* perror ("Select"); */
      return -1;
    }
    for(i=0; i<2; i++) {
      if (is_valid_socket(&server[i])
          && FD_ISSET(server[i].socket, &rd)) {
        p = accept_connection(server+i);
        if (p == purpose) return 1;
      }
    }
  }
}

/* direct stdin and stdout from the given socket */
OPENAXIOM_EXPORT void 
redirect_stdio(openaxiom_sio *sock)
{
  int fd;
/*  setbuf(stdout, NULL);  */
  fd = dup2(sock->socket, 1);
  if (fd != 1) {
    fprintf(stderr, "Error connecting stdout to socket\n");
    return;
  }
  fd = dup2(sock->socket, 0);
  if (fd != 0) {
    fprintf(stderr, "Error connecting stdin to socket\n");
    return;
  }
  fprintf(stderr, "Redirected standard IO\n");
  FD_CLR(sock->socket, &socket_mask);
}

OPENAXIOM_EXPORT void
init_socks(void)
{
  int i;
  FD_ZERO(&socket_mask);
  FD_ZERO(&server_mask);
  init_purpose_table();
  for(i=0; i<2; i++) server[i].socket = 0;
  for(i=0; i<MaxClients; i++) clients[i].socket = 0;
}

/* Socket I/O selection called from the BOOT serverLoop function */

OPENAXIOM_EXPORT int 
server_switch(void)
{
  int ret_val, i, cmd = 0;
  fd_set rd, wr, ex, fds_mask;
  FD_ZERO(&rd);
  FD_ZERO(&wr);
  FD_ZERO(&ex);
  fds_mask = server_mask;
  cmd = 0;
  if (purpose_table[SessionManager] != NULL) {
    FD_SET(0, &fds_mask);
    FD_SET(purpose_table[SessionManager]->socket, &fds_mask);
  }
  while (1) {
    do {
      if (purpose_table[MenuServer] != NULL) {
        FD_SET(purpose_table[MenuServer]->socket, &fds_mask);
      }
      rd = fds_mask;
      ret_val = select(FD_SETSIZE, (void *) &rd, (void *) 0, (void *) 0, (void *) 0);
      if (ret_val == -1) {
        /* perror ("Select in switch"); */
        return -1;
      }
      for(i=0; i<2; i++) {
        if (is_valid_socket(&server[i])
            && (FD_ISSET(server[i].socket, &rd)))
          accept_connection(server+i);
      }
    } while (purpose_table[SessionManager] == NULL);
    FD_SET(purpose_table[SessionManager]->socket, &fds_mask);
    if (FD_ISSET(purpose_table[SessionManager]->socket, &rd)) {
      cmd = get_int(purpose_table[SessionManager]);
      return cmd;
    }
    if (FD_ISSET(0, &rd)) {
      return CallInterp;
    }
    if (purpose_table[MenuServer] != NULL &&
        (FD_ISSET(purpose_table[MenuServer]->socket, &rd))) {
      cmd = get_int(purpose_table[MenuServer]);
      return cmd;
    }
  }
}

OPENAXIOM_EXPORT void 
flush_stdout(void)
{
  static FILE *fp = NULL;
  if (fp == NULL) {
    fp = fdopen(purpose_table[SessionIO]->socket, "w");
    if (fp == NULL) {
      perror("fdopen");
      return;
    }
  }
  fflush(fp);
}

OPENAXIOM_EXPORT void 
print_line(const char* s)
{
  printf("%s\n", s);
}