source: roaraudio/libroar/vio.c @ 5381:430b1d26e12d

//vio.c:

/*
 *      Copyright (C) Philipp 'ph3-der-loewe' Schafft - 2008-2012
 *
 *  This file is part of libroar a part of RoarAudio,
 *  a cross-platform sound system for both, home and professional use.
 *  See README for details.
 *
 *  This file is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 3
 *  as published by the Free Software Foundation.
 *
 *  libroar is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this software; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 51 Franklin Street, Fifth Floor,
 *  Boston, MA 02110-1301, USA.
 *
 *  NOTE for everyone want's to change something and send patches:
 *  read README and HACKING! There a addition information on
 *  the license of this document you need to read before you send
 *  any patches.
 *
 *  NOTE for uses of non-GPL (LGPL,...) software using libesd, libartsc
 *  or libpulse*:
 *  The libs libroaresd, libroararts and libroarpulse link this lib
 *  and are therefore GPL. Because of this it may be illigal to use
 *  them with any software that uses libesd, libartsc or libpulse*.
 */

#define _LIBROAR_NOATTR_TO_STATIC /* ignore warnings for TO_STATIC functions */
#include "libroar.h"

#ifdef ROAR_HAVE_H_SYS_IOCTL
#include <sys/ioctl.h>
#endif

#ifdef ROAR_HAVE_IO_POSIX
#define _CAN_OPERATE
#endif

int roar_vio_clear_calls (struct roar_vio_calls * calls) {
 if ( calls == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 memset((void*)calls, 0, sizeof(struct roar_vio_calls));
 calls->flags = ROAR_VIO_FLAGS_NONE;
 calls->refc  = 0;

 return 0;
}

static int roar_vio_get_fh   (struct roar_vio_calls * vio) {
 if ( vio == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 return ((int)(ROAR_INSTINT)vio->inst) - 1;
}


ssize_t roar_vio_read (struct roar_vio_calls * vio, void *buf, size_t count) {
 ssize_t ret;

 ROAR_DBG("roar_vio_read(vio=%p, buf=%p, count=%u) = ?", vio, buf, (unsigned int)count);

 if ( vio == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 if ( vio->read == NULL ) {
  roar_err_set(ROAR_ERROR_NOSYS);
  return -1;
 }

 roar_err_clear_all();
 ret = vio->read(vio, buf, count);
 roar_err_update();

 return ret;
}

ssize_t roar_vio_write(struct roar_vio_calls * vio, void *buf, size_t count) {
 ssize_t ret;

 ROAR_DBG("roar_vio_write(vio=%p, buf=%p, count=%u) = ?", vio, buf, (unsigned int)count);

 if ( vio == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 if ( vio->write == NULL ) {
  roar_err_set(ROAR_ERROR_NOSYS);
  return -1;
 }

 roar_err_clear_all();
 ret = vio->write(vio, buf, count);
 roar_err_update();

 return ret;
}

roar_off_t   roar_vio_lseek(struct roar_vio_calls * vio, roar_off_t offset, int whence) {
 roar_off_t ret;

 ROAR_DBG("roar_vio_lseek(vio=%p, offset=%li, whence=%i) = ?", vio, (long int)offset, whence);

 if ( vio == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 if ( vio->lseek == NULL ) {
  roar_err_set(ROAR_ERROR_NOSYS);
  return -1;
 }

 roar_err_clear_all();
 ret = vio->lseek(vio, offset, whence);
 roar_err_update();

 return ret;
}

int     roar_vio_nonblock(struct roar_vio_calls * vio, int state) {
 ROAR_DBG("roar_vio_nonblock(vio=%p, state=%i) = ?", vio, state);

 if ( vio == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 return roar_vio_ctl(vio, ROAR_VIO_CTL_NONBLOCK, &state);
}

int     roar_vio_sync    (struct roar_vio_calls * vio) {
 int ret;

 ROAR_DBG("roar_vio_sync(vio=%p) = ?", vio);

 if ( vio == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 if ( vio->sync == NULL ) {
  roar_err_set(ROAR_ERROR_NOSYS);
  return -1;
 }

 roar_err_clear_all();
 ret = vio->sync(vio);
 roar_err_update();

 return ret;
}

int     roar_vio_ctl     (struct roar_vio_calls * vio, roar_vio_ctl_t cmd, void * data) {
 int ret;

 ROAR_DBG("roar_vio_ctl(vio=%p, cmd=%i, data=%p) = ?", vio, cmd, data);

 if ( vio == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 ROAR_DBG("roar_vio_ctl(vio=%p, cmd=0x%.8x, data=%p): vio->ctl=%p", vio, cmd, data, vio->ctl);

 switch (cmd) {
  case ROAR_VIO_CTL_CONFLICTING_ID_0:
  case ROAR_VIO_CTL_CONFLICTING_ID_1:
    ROAR_ERR("roar_vio_ctl(vio=%p, cmd=0x%.8x, data=%p): Your progam uses a VIO ctl call with a conflicting ID.", vio, cmd, data);
    ROAR_ERR("roar_vio_ctl(vio=%p, cmd=0x%.8x, data=%p): Please recompile your program to fix this. (No additional steps are required beside that.)", vio, cmd, data);
    ROAR_DBG("roar_vio_ctl(vio=%p, cmd=0x%.8x, data=%p) = -1", vio, cmd, data);
    roar_err_set(ROAR_ERROR_BADRQC);
    return -1;
   break;
 }

 if ( vio->ctl == NULL ) {
  roar_err_set(ROAR_ERROR_NOSYS);
  return -1;
 }

 roar_err_clear_all();
 ret = vio->ctl(vio, cmd, data);
 roar_err_update();

 return ret;
}

int     roar_vio_close    (struct roar_vio_calls * vio) {
 int ret;

 ROAR_DBG("roar_vio_close(vio=%p) = ?", vio);

 if ( vio == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 if ( vio->close == NULL ) {
  roar_err_set(ROAR_ERROR_NOSYS);
  return -1;
 }

 roar_err_clear_all();
 ret = vio->close(vio);
 roar_err_update();

 return ret;
}

// specal commands:
int     roar_vio_accept  (struct roar_vio_calls * calls, struct roar_vio_calls * dst) {
 if (dst == NULL || calls == NULL) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 return roar_vio_ctl(dst, ROAR_VIO_CTL_ACCEPT, calls);
}

int     roar_vio_shutdown(struct roar_vio_calls * vio,   int how) {
 if (vio == NULL) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 if ( ( (how | ROAR_VIO_SHUTDOWN_READ|ROAR_VIO_SHUTDOWN_WRITE|ROAR_VIO_SHUTDOWN_LISTEN) -
        (ROAR_VIO_SHUTDOWN_READ|ROAR_VIO_SHUTDOWN_WRITE|ROAR_VIO_SHUTDOWN_LISTEN) ) != 0 ) {
  roar_err_set(ROAR_ERROR_INVAL);
  return -1;
 }

 return roar_vio_ctl(vio, ROAR_VIO_CTL_SHUTDOWN, &how);
}

// converters:
int     roar_vio_open_fh       (struct roar_vio_calls * calls, int fh) {
 if ( calls == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 memset((void*)calls, 0, sizeof(struct roar_vio_calls));

 calls->read     = roar_vio_basic_read;
 calls->write    = roar_vio_basic_write;
 calls->lseek    = roar_vio_basic_lseek;
 calls->sync     = roar_vio_basic_sync;
 calls->ctl      = roar_vio_basic_ctl;
 calls->close    = roar_vio_basic_close;

 calls->inst     = (void*)(ROAR_INSTINT)(fh + 1);

 return 0;
}

int     roar_vio_open_fh_socket(struct roar_vio_calls * calls, int fh) {
 if ( calls == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 if ( roar_vio_open_fh(calls, fh) == -1 )
  return -1;

#ifdef ROAR_TARGET_WIN32
 calls->read     = roar_vio_winsock_read;
 calls->write    = roar_vio_winsock_write;
 calls->sync     = roar_vio_winsock_sync;
 calls->ctl      = roar_vio_winsock_ctl;
 calls->close    = roar_vio_winsock_close;
#else
 calls->sync     = roar_vio_null_sync;
#endif

 return 0;
}

int     roar_vio_open_socket   (struct roar_vio_calls * calls, const char * host, int port) {
 int fh;

 if ( calls == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 if ( (fh = roar_socket_connect(ROAR_SOCKET_TYPE_UNKNOWN, host, port)) == -1 )
  return -1;

 return roar_vio_open_fh_socket(calls, fh);
}

int     roar_vio_open_socket_listen(struct roar_vio_calls * calls, int type, const char * host, int port) {
 int fh;

 if ( calls == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 if ( (fh = roar_socket_listen(type, host, port)) == -1 )
  return -1;

 return roar_vio_open_fh_socket(calls, fh);
}


// VIOs:

// basic
ssize_t roar_vio_basic_read (struct roar_vio_calls * vio, void *buf, size_t count) {
#ifdef _CAN_OPERATE
 return read(roar_vio_get_fh(vio), buf, count);
#else
 roar_err_set(ROAR_ERROR_NOSYS);
 return -1;
#endif
}

ssize_t roar_vio_basic_write(struct roar_vio_calls * vio, void *buf, size_t count) {
#ifdef _CAN_OPERATE
 return write(roar_vio_get_fh(vio), buf, count);
#else
 roar_err_set(ROAR_ERROR_NOSYS);
 return -1;
#endif
}

roar_off_t   roar_vio_basic_lseek(struct roar_vio_calls * vio, roar_off_t offset, int whence) {
#ifdef _CAN_OPERATE
 return lseek(roar_vio_get_fh(vio), offset, whence);
#else
 roar_err_set(ROAR_ERROR_NOSYS);
 return -1;
#endif
}

int     roar_vio_basic_sync    (struct roar_vio_calls * vio) {
#ifdef ROAR_FDATASYNC
 return ROAR_FDATASYNC(roar_vio_get_fh(vio));
#else
 return 0;
#endif
}

int     roar_vio_basic_ctl     (struct roar_vio_calls * vio, roar_vio_ctl_t cmd, void * data) {
#ifdef ROAR_HAVE_H_SYS_IOCTL
 struct roar_vio_sysio_ioctl * sysioctl;
#endif
#if defined(ROAR_HAVE_GETSOCKOPT) || defined(ROAR_HAVE_SETSOCKOPT)
 struct roar_vio_sysio_sockopt  * syssockopt;
#endif
 int tmp;
 int s_r = 0, s_w = 0;
#if defined(ROAR_HAVE_GETSOCKNAME) || defined(ROAR_HAVE_GETPEERNAME)
 union {
  struct sockaddr     sa;
#if defined(ROAR_HAVE_IPV4) || defined(ROAR_HAVE_IPV6)
  struct sockaddr_in  in;
#endif
#ifdef ROAR_HAVE_UNIX
  struct sockaddr_un  un;
#endif
#ifdef ROAR_HAVE_LIBDNET
  struct sockaddr_dn  dn;
#endif
#ifdef ROAR_HAVE_IPV6
  struct sockaddr_in6 in6;
#endif
#ifdef ROAR_HAVE_IPX
  struct sockaddr_ipx ipx;
#endif
 } sockaddr;
 socklen_t socklen;
 struct roar_sockname * rsockname;
#endif

 if ( vio == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 if ( cmd == -1 ) {
  roar_err_set(ROAR_ERROR_INVAL);
  return -1;
 }

 ROAR_DBG("roar_vio_basic_ctl(vio=%p, cmd=0x%.8x, data=%p) = ?", vio, cmd, data);

 switch (cmd) {
  case ROAR_VIO_CTL_GET_NAME:
    if ( data == NULL ) {
     roar_err_set(ROAR_ERROR_FAULT);
     return -1;
    }

    *(char**)data = "basic";
    return 0;
   break;
  case ROAR_VIO_CTL_GET_FH:
  case ROAR_VIO_CTL_GET_READ_FH:
  case ROAR_VIO_CTL_GET_WRITE_FH:
  case ROAR_VIO_CTL_GET_SELECT_FH:
  case ROAR_VIO_CTL_GET_SELECT_READ_FH:
  case ROAR_VIO_CTL_GET_SELECT_WRITE_FH:
    ROAR_DBG("roar_vio_basic_ctl(vio=%p, cmd=ROAR_VIO_CTL_GET_*FH(0x%.8x), data=%p) = 0 // fh=%i", vio, cmd, data, roar_vio_get_fh(vio));
    *(int*)data = roar_vio_get_fh(vio);
    return 0;
   break;
  case ROAR_VIO_CTL_SET_NOSYNC:
    vio->sync = NULL;
    return 0;
   break;
  case ROAR_VIO_CTL_ACCEPT:
    tmp = ROAR_ACCEPT(roar_vio_get_fh(vio), NULL, 0);
    if ( tmp == -1 )
     return -1;

    // most proably a socket.
    if ( roar_vio_open_fh_socket(data, tmp) == -1 ) {
#ifdef ROAR_TARGET_WIN32
     closesocket(tmp);
#else
     close(tmp);
#endif
     return -1;
    }

    return 0;
   break;
  case ROAR_VIO_CTL_SHUTDOWN:
    tmp = *(int*)data;

    if ( tmp & ROAR_VIO_SHUTDOWN_READ ) {
     s_r = 1;
     tmp -= ROAR_VIO_SHUTDOWN_READ;
    }

    if ( tmp & ROAR_VIO_SHUTDOWN_WRITE ) {
     s_w = 1;
     tmp -= ROAR_VIO_SHUTDOWN_WRITE;
    }

    if ( tmp != 0 ) { /* we currently only support R and W shutdowns */
     roar_err_set(ROAR_ERROR_NOTSUP);
     return -1;
    }

    if ( s_r && s_w ) {
     tmp = SHUT_RDWR;
    } else if ( s_r ) {
     tmp = SHUT_RD;
    } else if ( s_w ) {
     tmp = SHUT_WR;
    } else {
     return 0; // nothing to do.
    }

    return ROAR_SHUTDOWN(roar_vio_get_fh(vio), tmp);
   break;
#if defined(ROAR_HAVE_GETSOCKNAME) || defined(ROAR_HAVE_GETPEERNAME)
  case ROAR_VIO_CTL_GET_SOCKNAME:
  case ROAR_VIO_CTL_GET_PEERNAME:
    if ( data == NULL ) {
     roar_err_set(ROAR_ERROR_FAULT);
     return -1;
    }

    rsockname = data;

    socklen = sizeof(sockaddr);

    if ( cmd == ROAR_VIO_CTL_GET_SOCKNAME ) {
#ifdef ROAR_HAVE_GETSOCKNAME
     tmp = getsockname(roar_vio_get_fh(vio), &(sockaddr.sa), &socklen);
#else
     roar_err_set(ROAR_ERROR_NOSYS);
     return -1;
#endif
    } else if ( cmd == ROAR_VIO_CTL_GET_PEERNAME ) {
#ifdef ROAR_HAVE_GETPEERNAME
     tmp = getpeername(roar_vio_get_fh(vio), &(sockaddr.sa), &socklen);
#else
     roar_err_set(ROAR_ERROR_NOSYS);
     return -1;
#endif
    } else {
     // memory corruption:
     roar_panic(ROAR_FATAL_ERROR_MEMORY_CORRUPTION, NULL);
     roar_err_set(ROAR_ERROR_CHERNOBYL);
     return -1;
    }

    if ( tmp == -1 )
     return -1;

    memset(rsockname, 0, sizeof(struct roar_sockname));

    switch (sockaddr.sa.sa_family) {
#if defined(AF_UNIX) && defined(ROAR_HAVE_UNIX)
     case AF_UNIX:
       rsockname->type = ROAR_SOCKET_TYPE_UNIX;
       if ( sockaddr.un.sun_path[0] == 0 ) {
        rsockname->addr = roar_mm_malloc(sizeof(sockaddr.un.sun_path));
        if ( rsockname->addr == NULL )
         return -1;
        memcpy(rsockname->addr, sockaddr.un.sun_path, sizeof(sockaddr.un.sun_path));
       } else {
        rsockname->addr = roar_mm_strdup(sockaddr.un.sun_path);
       }
      break;
#endif
#if defined(AF_DECnet) && defined(ROAR_HAVE_LIBDNET)
     case AF_DECnet:
       rsockname->type = ROAR_SOCKET_TYPE_DECNET;

       if ( sockaddr.dn.sdn_add.a_len != 2 ) {
        roar_err_set(ROAR_ERROR_NOTSUP);
        return -1;
       }

       rsockname->addr = roar_mm_malloc(28);
       if ( rsockname->addr == NULL )
        return -1;

       snprintf(rsockname->addr, 28, "%i.%i::",
                 sockaddr.dn.sdn_add.a_addr[1] >> 2,
                 sockaddr.dn.sdn_add.a_addr[0] + ((sockaddr.dn.sdn_add.a_addr[1] & 0x03) << 8));

       rsockname->port = sockaddr.dn.sdn_objnum;
       if ( sockaddr.dn.sdn_objnum == 0 ) {
        tmp = strlen(rsockname->addr);
        memcpy(rsockname->addr + tmp, sockaddr.dn.sdn_objname, sockaddr.dn.sdn_objnamel);
        rsockname->addr[tmp + sockaddr.dn.sdn_objnamel] = 0;
       }
      break;
#endif
#if defined(AF_INET) && (defined(ROAR_HAVE_IPV4) || defined(ROAR_HAVE_IPV6))
     case AF_INET:
       rsockname->type = ROAR_SOCKET_TYPE_INET;
       rsockname->port = ntohs(sockaddr.in.sin_port);
       rsockname->addr = roar_mm_strdup(inet_ntoa(sockaddr.in.sin_addr));
      break;
#endif
#if defined(AF_INET6) && defined(ROAR_HAVE_IPV6)
     case AF_INET6:
       rsockname->type = ROAR_SOCKET_TYPE_INET6;
       rsockname->port = ntohs(sockaddr.in6.sin6_port);
      break;
#endif
     default:
       roar_err_set(ROAR_ERROR_NOTSUP);
       return -1;
    }
    return 0;
#endif
   break;
#ifdef ROAR_HAVE_H_SYS_IOCTL
  case ROAR_VIO_CTL_SYSIO_IOCTL:
    sysioctl = data;
    return ioctl(roar_vio_get_fh(vio), sysioctl->cmd, sysioctl->argp);
   break;
#endif
#ifdef ROAR_HAVE_GETSOCKOPT
  case ROAR_VIO_CTL_GET_SYSIO_SOCKOPT:
    syssockopt = data;
    return getsockopt(roar_vio_get_fh(vio), syssockopt->level, syssockopt->optname, syssockopt->optval, &(syssockopt->optlen));
   break;
#endif
#ifdef ROAR_HAVE_SETSOCKOPT
  case ROAR_VIO_CTL_SET_SYSIO_SOCKOPT:
    syssockopt = data;
    return setsockopt(roar_vio_get_fh(vio), syssockopt->level, syssockopt->optname, syssockopt->optval, syssockopt->optlen);
   break;
#endif
  case ROAR_VIO_CTL_NONBLOCK:
    if ( roar_socket_nonblock(roar_vio_get_fh(vio), *(int*)data) == -1 )
     return -1;

    if ( *(int*)data == ROAR_SOCKET_NONBLOCK )
     return 0;

    roar_vio_sync(vio);
    return 0;
   break;
 }

 roar_err_set(ROAR_ERROR_BADRQC);
 return -1;
}

int     roar_vio_basic_close    (struct roar_vio_calls * vio) {
#ifdef _CAN_OPERATE
 if ( roar_vio_get_fh(vio) != -1 )
  return close(roar_vio_get_fh(vio));

 return 0;
#else
 roar_err_set(ROAR_ERROR_NOSYS);
 return -1;
#endif
}

// null
ssize_t roar_vio_null_rw    (struct roar_vio_calls * vio, void *buf, size_t count) {
 (void)count;

 if ( vio == NULL || buf == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 return 0;
}

int     roar_vio_null_sync    (struct roar_vio_calls * vio) {
 (void)vio;
 return 0;
}

// pass
int     roar_vio_open_pass    (struct roar_vio_calls * calls, struct roar_vio_calls * dst) {
 if ( calls == NULL || dst == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 memset((void*)calls, 0, sizeof(struct roar_vio_calls));

 calls->read     = roar_vio_pass_read;
 calls->write    = roar_vio_pass_write;
 calls->lseek    = roar_vio_pass_lseek;
 calls->sync     = roar_vio_pass_sync;
 calls->ctl      = roar_vio_pass_ctl;
 calls->close    = roar_vio_pass_close;

 calls->inst     = dst;

 return 0;
}

ssize_t roar_vio_pass_read (struct roar_vio_calls * vio, void *buf, size_t count) {
 return roar_vio_read((struct roar_vio_calls *) vio->inst, buf, count);
}

ssize_t roar_vio_pass_write(struct roar_vio_calls * vio, void *buf, size_t count) {
 return roar_vio_write((struct roar_vio_calls *) vio->inst, buf, count);
}

roar_off_t   roar_vio_pass_lseek(struct roar_vio_calls * vio, roar_off_t offset, int whence) {
 return roar_vio_lseek((struct roar_vio_calls *) vio->inst, offset, whence);
}

int     roar_vio_pass_sync    (struct roar_vio_calls * vio) {
 return roar_vio_sync((struct roar_vio_calls *) vio->inst);
}

int     roar_vio_pass_ctl     (struct roar_vio_calls * vio, roar_vio_ctl_t cmd, void * data) {
 if (vio == NULL) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 if (cmd == -1) {
  roar_err_set(ROAR_ERROR_INVAL);
  return -1;
 }

 ROAR_DBG("roar_vio_pass_ctl(vio=%p, cmd=0x%.8x, data=%p) = ?", vio, cmd, data);

 switch (cmd) {
  case ROAR_VIO_CTL_GET_NAME:
    if ( data == NULL ) {
     roar_err_set(ROAR_ERROR_FAULT);
     return -1;
    }

    // dirty trick to get real name...
    if ( vio->read == roar_vio_re_read ) {
     *(char**)data = "re";
    } else {
     *(char**)data = "pass";
    }
    return 0;
   break;
  case ROAR_VIO_CTL_GET_NEXT:
    *(struct roar_vio_calls **)data = vio->inst;
    return 0;
   break;
  case ROAR_VIO_CTL_SET_NEXT:
    vio->inst = *(struct roar_vio_calls **)data;
    return 0;
   break;
 }

 return roar_vio_ctl((struct roar_vio_calls *) vio->inst, cmd, data);
}

int     roar_vio_pass_close   (struct roar_vio_calls * vio) {
 return roar_vio_close((struct roar_vio_calls *) vio->inst);
}


// re
int     roar_vio_open_re (struct roar_vio_calls * calls, struct roar_vio_calls * dst) {
 if ( roar_vio_open_pass(calls, dst) == -1 )
  return -1;

 calls->read  = roar_vio_re_read;
 calls->write = roar_vio_re_write;
 calls->lseek = roar_vio_re_lseek;

 return 0;
}
ssize_t roar_vio_re_read (struct roar_vio_calls * vio, void *buf, size_t count) {
  size_t len =  0;
 ssize_t r   = -1;

 if ( vio == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 if ( vio->inst == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 roar_err_clear_all();

 while ( (r = roar_vio_read((struct roar_vio_calls *) vio->inst, buf, count)) > 0 ) {
  len   += r;
  buf   += r;
  count -= r;
  if ( count == 0 )
   break;
 }

 if ( len == 0 && r == -1 )
  return -1;

 return len;
}

ssize_t roar_vio_re_write(struct roar_vio_calls * vio, void *buf, size_t count) {
  size_t len =  0;
 ssize_t r   = -1;

 if ( vio == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 if ( vio->inst == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 roar_err_clear_all();

 while ( (r = roar_vio_write((struct roar_vio_calls *) vio->inst, buf, count)) > 0 ) {
  len   += r;
  buf   += r;
  count -= r;
  if ( count == 0 )
   break;
 }

 if ( len == 0 && r == -1 )
  return -1;

 return len;
}

// TODO: we should do a some more intelgent thing here.
roar_off_t   roar_vio_re_lseek(struct roar_vio_calls * vio, roar_off_t offset, int whence) {
 return roar_vio_lseek((struct roar_vio_calls *) vio->inst, offset, whence);
}

//ll