/*****************************************************************
 *
 * Program: check_pgsql.c
 * License: GPL
 *
 * Written by J. Javier Sianes - skyo@rotxa.org
 * Based on MySQL check program written by Tim Weippert
 *
 * Command line: check_pgsql <host> user passwd [db] [port]
 *      <host> can be the FQDN or the IP-Adress
 *	[db] and [port] are optional
 *	
 * Description:
 * 
 * This plugin attempts to connect to an PostgreSQL Server
 * with the optional specified parameters db and port.
 *
 * The plugin returns 
 * STATE_OK and the Version Number of the Server when all is fine
 * STATE_CRITICAL if the Connection can't be esablished
 * STATE_WARNING if the connection was established but the 
 * program can't get the Versoin Number
 * STATE_UNKNOWN if to many parameters are given
 *
 * Copyright (c) 2006 by J. Javier Sianes
 *
 *******************************************************************/

/*****************************************************************
 *
 * Note that all includes are related to Nagios and PostgreSQL default installation.
 * If you have installed them on a different location, you may change
 * the following include lines in order to make it works. 
 * 
 * To compile the agent, in a shell use the following command, for example:
 *
 * gcc -lpq -o check_pgsql check_pgsql.c
 *
 *******************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include "/usr/include/nagios/config.h"
#include "/usr/include/nagios/common.h"
#include "/usr/include/nagios/nagios.h"
#include "/usr/include/libpq-fe.h"
#define TAM_BLK 1024

PGconn *ConexionPG=NULL;

char *PGVersion(int version) {
  int i=0,j=0,k=0,len,par=1,cont=0;
  char *cad=NULL,*res=NULL,num[3];

  cad=(char *)malloc(TAM_BLK*sizeof(char));
  res=(char *)malloc(TAM_BLK*sizeof(char));
  if ((cad==NULL)||(res==NULL)){
    free(cad);
    free(res);
    return NULL;
  } 

  for (k=0;k<TAM_BLK;k++) { cad[k]='\0'; res[k]='\0'; } 
  for (k=0;k<3;k++) { num[k]='\0'; }

  sprintf(cad,"%d",version);
  len=strlen(cad);
  if (len%2!=0) { par=0; }

  for (i=0;i<len;i++) {
    if (cont==2) {
      cont=0;
      if (num[1]=='0') {
        res[j++]=num[0];
        res[j++]='.';
      } else {
        res[j++]=num[0];
        res[j++]=num[1];
        res[j++]='.';
      }
      for (k=0;k<3;k++) { num[k]='\0'; }
    }

    num[cont]=cad[i];
    
    if (i==(len-1)) {
      if (par) {
        res[j++]=num[0];
        res[j++]=num[1];
      } else {
        res[j++]=num[0];
      }
    }

    cont++; 
  }

  free(cad);
  return res;
}

int main(int argc, char **argv)
{
  uint i = 0;
  int version,mport;
  char *host;
  char *user;
  char *passwd;
  char *db;
  char *PgConnectChain=NULL;
  char *cversion=NULL;
  
  PgConnectChain=(char *)malloc(TAM_BLK*sizeof(char));

  if (PgConnectChain==NULL) {
    printf("PGSQL UNKNOWN - Not enough memory to allocate data !");
    return STATE_UNKNOWN;
  }

  if ( ( argc > 6 ) || ( argc < 4 ) ) {
    printf("Incorrect number of arguments supplied - %i .\n", argc);
    printf("Usage: %s <host> user passwd [db] [port]\n", argv[0]);
    free(PgConnectChain);
    return STATE_UNKNOWN;
  }

  host = argv[1];
  user = argv[2];
  passwd = argv[3];
  (db = argv[4]) || (db = "postgres");
  if (argc==6) { mport = atoi(argv[5]); } else { mport = 5432; }
 
  sprintf(PgConnectChain, "host=%s port=%d dbname=%s user=%s password=%s",host,mport,db,user,passwd);
  ConexionPG=PQconnectdb(PgConnectChain);

  if (PQstatus(ConexionPG) != CONNECTION_OK)
  {
    printf("PGSQL ERROR - Connection to database '%s' failed: %s",db,PQerrorMessage(ConexionPG));
    free(PgConnectChain);
    PQfinish(ConexionPG);
    return STATE_CRITICAL;
  }
  
  version=PQserverVersion(ConexionPG);
  if (version > 0 ) {
    cversion=PGVersion(version);
    if (cversion==NULL) {
      printf("PGSQL UNKNOWN - Not enough memory to allocate data !");
      free(PgConnectChain);
      PQfinish(ConexionPG);
      return STATE_UNKNOWN;
    }
    printf("PGSQL OK - Running Version: postmaster (PostgreSQL) %s\n",cversion);
  } else {
    printf("Connect OK, but can't get Serverinfo ... something wrong !\n");
    free(PgConnectChain);
    PQfinish(ConexionPG);
    return STATE_WARNING;
  }

  free(PgConnectChain);
  PQfinish(ConexionPG);
  return STATE_OK;
}