/*
 * check_remote_disk_space.c
 * 20/01/2006
 * Check the percent of avalaible partition space in a remote server using snmp
 * it works as a nagios plugin too , see the last part of main function
 * i compile in this way:
 * # gcc -lnetsnmp -lcrypto -Wall -pedantic thisfile.c -O3 -fomit-frame-pointer -funroll-loops -o check_remote_disk_space
 * by
 * Eduardo Ruiz Duarte
 * erduarte@telmex.com
 */
#include <net-snmp/net-snmp-config.h>

#if HAVE_STDLIB_H
#include <stdlib.h>
#endif
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_STRING_H
#include <string.h>
#else
#include <strings.h>
#endif
#include <sys/types.h>
#if HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#include <stdio.h>
#include <ctype.h>
#if TIME_WITH_SYS_TIME
#ifdef WIN32
#include <sys/timeb.h>
#else
#include <sys/time.h>
#endif
#include <time.h>
#else
#if HAVE_SYS_TIME_H
#include <sys/time.h>
#else
#include <time.h>
#endif
#endif
#if HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif
#if HAVE_WINSOCK_H
#include <winsock.h>
#endif
#if HAVE_NETDB_H
#include <netdb.h>
#endif
#if HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif

#include <net-snmp/utilities.h>

#include <net-snmp/net-snmp-includes.h>

int failures = 0;
#define HDESCR "hrStorageDescr.%d"
#define HSIZE "hrStorageSize.%d"
#define HUSED "hrStorageUsed.%d"
#define NETSNMP_DS_APP_DONT_FIX_PDUS 0
int
snmp_query_beck (char *community, int version, char *query,
		                 char *host, char *buf);
void
usage (void)
{
  fprintf (stderr,
	   "check_remote_disk_space 0.1 by Eduardo Ruiz Duarte\nerduarte@telmex.com\n");
  fprintf (stderr,
	   "-H host (ip or hostname)\n-c community (public,ro_public,etc..)\n-v version (usually 1,2c or 3)\n-p partition (/export/home,c:)\n");
  fprintf (stderr,
	   "Optional flags are:\n-l (to dump all the partition descriptions)\nthe order of the flags has no significance\n");
  fprintf (stderr,"Example:\n# check_remote_disk_space -v 2c -p /export/home -c public -H 10.108.132.13 -l\n");
}

int
main (int argc, char **argv)
{
  char id=0,buf[512], *tptr,*comm=0, *host=0, *partition=0, tmp[sizeof (HDESCR)],*tname;
  const char *str = "STRING: \0", *inte = "INTEGER: \0";
  unsigned int version=0, i, vflag, cflag, hflag, pflag, lflag, total_size=0,used_size=0;
  float percent;
  if (argc == 1)
    {
      usage ();
      exit (EXIT_FAILURE);
    }
  lflag = vflag = cflag = hflag = pflag = 0;
  for (i = 0; i < argc; i++)
    {
      if ((argv[i][0] == '-') && (argv[i][1] == 'v'))
	{
	  if (argv[i + 1] == NULL)
	    {
	      fprintf (stderr, "-v requires an argument e.g. (1,2c or 3)\n");
	      exit (EXIT_FAILURE);
	    }
	  if (strcmp (argv[i + 1], "1") == 0)
	    {
	      version = SNMP_VERSION_1;
	      vflag = 1;
	    }
	  if (strcmp (argv[i + 1], "2c") == 0)
	    {
	      version = SNMP_VERSION_2c;
	      vflag = 1;
	    }
	  if (strcmp (argv[i + 1], "3") == 0)
	    {
	      version = SNMP_VERSION_3;
	      vflag = 1;
	    }
	  else if (vflag != 1)
	    {
	      fprintf (stderr,
		       "Version \'%s\' unknown , it has to be \'1\',\'2c\' or \'3\'\n",
		       argv[i + 1]);
	      usage ();
	      exit (EXIT_FAILURE);
	    }
	}
      if ((argv[i][0] == '-') && (argv[i][1] == 'c'))
	{
	  if (argv[i + 1] == NULL)
	    {
	      fprintf (stderr,
		       "-c requires an argument e.g. \'public\'\n");
	      usage ();
	      exit (EXIT_FAILURE);
	    }
	  comm = argv[i + 1];
	  cflag = 1;
	}
      if ((argv[i][0] == '-') && (argv[i][1] == 'l'))
	lflag = 1;

      if ((argv[i][0] == '-') && (argv[i][1] == 'H'))
	{
	  if (argv[i + 1] == NULL)
	    {
	      fprintf (stderr,
		       "-H requires an argument e.g. \'192.168.1.2\'\n");
	      usage ();
	      exit (EXIT_FAILURE);
	    }
	  host = argv[i + 1];
	  hflag = 1;
	}
      if ((argv[i][0] == '-') && (argv[i][1] == 'p'))
	{
	  if (argv[i + 1] == NULL)
	    {
	      fprintf (stderr,
		       "-p requires an argument e.g. \'/export/home or C:\'\n");
	      usage ();
	      exit (EXIT_FAILURE);
	    }
	  partition = argv[i + 1];
	  pflag = 1;
	}
      if ((argv[i][0] == '-') && (argv[i][1] == 'h'))
	{
	  usage ();
	  exit (EXIT_FAILURE);
	}

    }
  if (cflag == 0)
    {
      fprintf (stderr,
	       "You need to specify a community with option -c\n");
      exit (EXIT_FAILURE);
    }
  if (vflag == 0)
    {
      fprintf (stderr, "You need to specify the version of th snmp protocol tu use with -v\n");
      exit (EXIT_FAILURE);
    }
  if (pflag == 0)
    {
      fprintf (stderr,
	       "You need to specify a partition to check avalaible space with -p\n");
      exit (EXIT_FAILURE);
    }
  if (hflag == 0)
    {
	    usage();
      exit (EXIT_FAILURE);
    }
  memset (&tmp, 0x0, sizeof (HDESCR));
  if ((partition[strlen (partition) - 1] == '/') && (strlen(partition) > 1))
    partition[strlen (partition) - 1] = 0;
  if((tptr = strchr(partition,':')) != NULL) 
	  partition[0] = tolower(partition[0]);
#define MAX_PART 32
  for (i = 1; i < MAX_PART; i++)
    {
      sprintf ((char *) &tmp, HDESCR, i);
      memset (&buf, 0x0, sizeof (buf));
      if (snmp_query_beck (comm, version, tmp, host,(char *) &buf) != 0)
	fprintf (stderr, "Error getting %s.. procedding\n", tmp);
      tname = strstr ((char *) &buf, str);
      if (tname != NULL)
	{
	  tname = tname + strlen (str);
	  if((tptr=strchr(tname,':')) != NULL)
	  {
		  tptr[1] = 0;
		  tname[0] = tolower(tname[0]);
	  }
	  if (lflag)
	    printf ("Partition[%d] = %s\n", i, tname);
	  if (strcmp (tname, partition) == 0)
	    {
	      id = i;
	      i = MAX_PART;
	    }
	}
    }
  if (id == 0)
    {
      fprintf (stderr, "Partition %s not found in server %s\n", partition,
	       host);
      exit (EXIT_FAILURE);
    }

  memset (&buf, 0x0, sizeof (buf));
  sprintf ((char *) &tmp, HSIZE, id);
  if (snmp_query_beck (comm, version, tmp, host, (char *)&buf) != 0)
    fprintf (stderr, "Error getting %s.. proceeding\n", tmp);
  tname = strstr ((char *) &buf, inte);
  if (tname != NULL)
    {
      tname = tname + strlen (inte);
      total_size = atoi (tname);
    }
  memset (&buf, 0x0, sizeof (buf));
  sprintf ((char *) &tmp, HUSED, id);
  if (snmp_query_beck (comm, version, tmp, host,(char *) &buf) != 0)
    fprintf (stderr, "Error getting %s.. proceeding\n", tmp);
  tname = strstr ((char *) &buf, inte);
  if (tname != NULL)
    {
      tname = tname + strlen (inte);
      used_size = atoi (tname);
    }
  if (total_size == 0)
    percent = 0;
  else
    percent = (float) ((float) (used_size * 100) / (float) total_size);
#define OK 0
#define WARN 1
#define CRIT 2
#define UNK 3
  if (percent < 50)
    {
      fprintf (stderr,"OK: ");
      printf ("Mount point: %s avalaible: %.2f%%\n", partition, 100-percent);
      return OK;
    }
  if (percent < 75)
    {
      fprintf (stderr,"WARNING: ");
      printf ("Mount point: %s avalaible: %.2f%%\n", partition, 100-percent);
      return WARN;
    }
  if (percent <= 100)
    {
      fprintf (stderr,"CRITICAL: ");
      printf ("Mount point: %s avalaible: %.2f%%\n", partition, 100-percent);
      return CRIT;
    }
  if(percent < 0 || percent > 100)
    {
      fprintf (stderr,"?????: ");
      printf ("Mount point: %s avalaible: %.2f%%\n", partition, 100-percent);
      return UNK;
    }

  return UNK;

}

int
snmp_query_beck (char *community, int version, char  *query,
		 char *host, char *buf)
{
  netsnmp_session session, *ss;
  netsnmp_pdu *pdu,*response;
  netsnmp_variable_list *valores;
  int debug, ret = 0, i;
  oid name[MAX_OID_LEN];
  size_t namelen;
  snmp_sess_init (&session);
  session.version = version;
  session.community = (unsigned char *) community;
  session.community_len = strlen ((char *) community);
  init_snmp ("snmpapp");
  session.peername = host;
  SOCK_STARTUP;

  ss = snmp_open (&session);
  if (ss == NULL)
    {
      snmp_sess_perror ("snmpget", &session);
      SOCK_CLEANUP;
      exit (1);
    }
  pdu = snmp_pdu_create (SNMP_MSG_GET);


  namelen = MAX_OID_LEN;
  if (!snmp_parse_oid ((char *) query, name, &namelen))
    {
      snmp_perror ((char *) query);
      failures++;
    }
  else
    snmp_add_null_var (pdu, name, namelen);
  if (failures)
    {
      SOCK_CLEANUP;
      exit (1);
    }
retry:
  debug = snmp_synch_response (ss, pdu, &response);
  if (debug == STAT_SUCCESS)
    {
      if (response->errstat == SNMP_ERR_NOERROR)
	{
	  valores = response->variables;
	  snprint_variable (buf, 512, valores->name, valores->name_length, valores);
	}
      else
	{
	  fprintf (stderr, "Error in packet\nReason: %s\n",
		   snmp_errstring (response->errstat));
	  exit(EXIT_FAILURE);
	   
	  if (response->errindex != 0)
	    {
	      fprintf (stderr, "MIB object failed..  exists ?: ");
	      for (i = 1, valores = response->variables;
		   valores && i != response->errindex;
		   valores = valores->next_variable, i++)
		if (valores)
		    fprint_objid (stderr, valores->name, valores->name_length);
	      fprintf (stderr, "\n");
	    }
	  ret = 2;

	  if (!netsnmp_ds_get_boolean (NETSNMP_DS_APPLICATION_ID,
				       NETSNMP_DS_APP_DONT_FIX_PDUS))
	    {
	      pdu = snmp_fix_pdu (response, SNMP_MSG_GET);
	      snmp_free_pdu (response);
	      response = NULL;
	      if (pdu != NULL)
		goto retry;
	    }
	}

    }
  else if (debug == STAT_TIMEOUT)
    {
      fprintf (stderr, "Timeout: from %s.\n", session.peername);
      ret = 1;

    }
  else
    {
      snmp_sess_perror ("snmpget", ss);
      ret = 1;

    }


  if (response)
    snmp_free_pdu (response);
  snmp_close (ss);
  SOCK_CLEANUP;
  return ret;

}