/* * mbus.c - general purpose libmbus functions * * Copyright (c) 2003, Victor Antonovich (avmlink@vlink.ru) *  * 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. *  * 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 REGENTS 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. * * $Id: mbus.c,v 1.3 2003/09/13 16:48:03 avm Exp $ */#include "mbus.h" extern int mbus_sock_create_client(const char *server_addr,             mbus_uword server_port, int blkmode);#define MBUS_CHECK_INIT(p) \   do { if ((p)->is_initialized != MBUS_FL_IS_INITIALIZED) \        return -1; } while (0);/* * Get library version info * * Returns: pointer to library version internal string. */char *mbus_version(  mbus_struct *mbus /* pointer to MODBUS structure */){  mbus = mbus; /* prevent compiler warning */  return ("\n libmbus version " LIBMBUS_VERSION "\n"          " Copyright (c) 2003 Victor Antonovich\n");}/* * Initialization of MBUS structure * * Returns: Pointer to structure (NULL in case of error). * * Note: This function must be called before any call to *       the library just once for each MBUS stucture */mbus_struct *mbus_init(  mbus_struct *mbus /* Pointer to structure to be initialized                       (if NULL - the memory will be allocated                       for the structure before initializing) */){  if (mbus == NULL)  { /* mbus structure yet isn't exist, create it */    if ((mbus =           (mbus_struct *)malloc(sizeof(mbus_struct))) != NULL)    { /* initialize created structure */      memset((void *)mbus, 0, sizeof(mbus_struct));      mbus->flags |= MBUS_FL_FREE_ON_EXIT;    }    else return NULL;  }  else    mbus->flags = 0; /* zero all flags */  mbus->sd = -1;  mbus->timeout = MBUS_SOCK_TIMEOUT;  mbus->is_initialized = MBUS_FL_IS_INITIALIZED;  /* initialized successfully */  return mbus;}/* * Connect to mbusd server * * Returns: 0 if successfully connected; *         -1 in case of error. */intmbus_connect(  mbus_struct *mbus,     /* Pointer to MBUS structure */  const char *host_addr, /* mbusd server host address (DNS or canonical form) */  mbus_uword host_port,  /* mbusd IP port (1-65535) */  mbus_uword flags       /* Additional flags (isn't used in this version) */){  MBUS_CHECK_INIT(mbus);  if (mbus->sd >= 0)    return mbus_reconnect(mbus);  (void)strncpy(mbus->host_addr, host_addr, MBUS_HOSTNAME_LENGTH);  mbus->host_port = host_port;  mbus->flags = flags;  mbus->sd =    mbus_sock_create_client(mbus->host_addr, mbus->host_port, 0);  return (mbus->sd == -1) ? -1 : 0;}/* * Reconnect to mbusd server *  * Returns: 0 if successfully reconnected; *         -1 in case of error. */intmbus_reconnect(  mbus_struct *mbus /* Pointer to MBUS structure */){  MBUS_CHECK_INIT(mbus);  if (mbus->sd < 0)    return -1; /* not connected yet */  close(mbus->sd);  mbus->sd =    mbus_sock_create_client(mbus->host_addr, mbus->host_port, 0);  return (mbus->sd == -1) ? -1 : 0;}/* * Disconnect from mbusd server *  * Returns: 0 if connection successfully closed; *         -1 in case of error. */intmbus_close(  mbus_struct *mbus /* Pointer to MBUS structure */){  MBUS_CHECK_INIT(mbus);  if (mbus->sd >= 0)    close(mbus->sd);  mbus->sd = -1;  if (mbus->flags & MBUS_FL_FREE_ON_EXIT)    free((void *)mbus);  return 0;}/* * Get last request exception code * * Returns: Exception code (0-255). */mbus_ubytembus_excode(  mbus_struct *mbus /* Pointer to MBUS structure */){  MBUS_CHECK_INIT(mbus);  return mbus->ex_code;}/* * Get connection status code * * Returns: -1 if structure is not initialized; *           0 if connection is not established; *           1 if successfully connected. */intmbus_connected(  mbus_struct *mbus /* Pointer to MBUS structure */){  MBUS_CHECK_INIT(mbus);  return (mbus->sd >= 0) ? 1 : 0;}