/**
 * \file udptabq.c
 *
 *  Extracts data in 'at' table from MIB II.
 *
 *  Makes query to MIB using SNMP protocol and types obtained
 *  data on standard output.
 *
 *  Run: > ./udptabq host
 *    where 'host' is name of SNMP agent (for example  ds02)
 *
 *  Extracts and prints  the same data as: > snmptable host public at.atTable
 *
 * \author Tomas Jirak, Vladimir Sochor
 * \date 2003 
 */

#include "snmp.h"
#include "snmp_api.h"
#include "mib.h"
#include "mibquery.h"

#include <arpa/inet.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

int val_count;
char *tab_values[2*MAX_ROW_COUNT];
char my_addr[16], agent_addr[16];
struct snmp_session session;
struct snmp_session *p_session;

int main(int argc, char *argv[]);

/**
 *  Main.
 */
int main(int argc, char *argv[])
{ 
  char mibTabID[]= "3.1.1.1";  // at table ID
  int i, res;

  char my_hname[20];
  struct hostent *h_ent;
  unsigned long int *h_address;
  struct in_addr h_ip_addr;
  char *h_ip;

  printf("**** Program for extracting data from 'at' table in MIB II ****\n");
  printf("****   authors:  Tomas Jirak & Vladimir Sochor, 2003       ****\n\n");
  
  if (argc < 2) {
    printf("Syntaxe: %s host\n", argv[0]); 
    printf("  One argument required - input host name or host IP address.\n");
    return(-1);
  }

  /* Get my host name */
  res = gethostname(my_hname, 20);
  if (res < 0) {
    error_msg(errno, "Cannot get my hostname");
    return(-1);
  }

  /* Get my IP address */
  h_ent = gethostbyname(my_hname);
  if (h_ent == NULL) {
    error_msg(errno, "Cannot get my IP address");
    return(-1);
  }

  h_address = (unsigned long int *) (h_ent->h_addr);
  h_ip_addr.s_addr = *h_address;
  h_ip = inet_ntoa(h_ip_addr);
  strcpy(my_addr, h_ip);

/*  Get SNMP agent by his IP address:
 *  if (gethostbyaddr(argv[1], 4, AF_INET) != NULL)
 *    strcpy(agent_addr, argv[1]);
 */

  /* Get SNMP agent by his name */
  h_ent = gethostbyname(argv[1]);
  if (h_ent == NULL) { 
    error_msg(errno, "Incorrect SNMP agent name.");
    return(-1);
  }
  h_address = (unsigned long int *) (h_ent->h_addr);
  h_ip_addr.s_addr = *h_address;
  h_ip = inet_ntoa(h_ip_addr);
  strcpy(agent_addr, h_ip);
 
  printf("SNMP Manager - input parameters for connection\n");
  printf("  SNMP manager (client):  %s %s\n", my_hname, my_addr);
  printf("  SNMP agent (server):  %s %s\n\n", h_ent->h_name, agent_addr);

  initmib("");

  bzero((char *) &session, sizeof(struct snmp_session));
  session.peername = h_ent->h_name;
  session.community = (u_char *) "public";
  session.community_len = strlen((char *) "public");
  session.retries = SNMP_DEFAULT_RETRIES;
  session.timeout = SNMP_DEFAULT_TIMEOUT;
  session.authenticator = NULL;

  printf("SNMP Manager:  Opening session ... \n");

  snmp_synch_setup(&session);
  p_session = snmp_open(&session);
  if (p_session == NULL) {
    error_msg(errno, "Opening of SNMP session failed");
    return(-1);
  }

  res = 1;
  i = 1;
  val_count = 0;
  /* obtain requested data from MIB */
  while (res && i < 4)
  {
    sprintf(mibTabID,"3.1.1.%d", i);
    res = mib_query(argv[1], mibTabID);
    i++;
  }
  
  printf("SNMP Manager:  Closing session ... \n\n");
  if (!snmp_close(p_session)) {
    error_msg(errno, "Closing of SNMP session failed.");
    return(-1);
  }

  printf("SNMP table: at.atTable\n\n");
  print_table(val_count);

  for (i = 0; i < val_count; i++)
    free((char *) tab_values[i]);

  printf("Bye ...\n\n");

  return(0);
}