nagios-plugins/plugins-root/check_icmp.c

/*****************************************************************************
 *
 * Nagios check_icmp plugin
 *
 * License: GPL
 * Copyright (c) 2005-2008 Nagios Plugins Development Team
 * Original Author : Andreas Ericsson
 * Jitter, MOS and Score support added by Alessandro Ren
 * IPv6 / ICMPv6 support added by Troy Lea aka Box293
 *  Credit for IPv6 / ICMPv6 code is given to Lars Michelsen as per the GitHib
 *  commit ec656bf4b3747c0987815d2f3b4ef96bce5613b6.
 *
 * * Description:
 *
 * This file contains the check_icmp plugin
 *
 * Relevant RFC's: 792 (ICMP), 4443 (ICMPv6), 791 (IP), 2460 (IPv6)
 *
 * This program was modeled somewhat after the check_icmp program,
 * which was in turn a hack of fping (www.fping.org) but has been
 * completely rewritten since to generate higher precision rta values,
 * and support several different modes as well as setting ttl to control.
 * redundant routes. The only remainders of fping is currently a few
 * function names.
 *
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 *****************************************************************************/

char *progname;
const char *copyright = "2005-2018";
const char *email = "devel@nagios-plugins.org";

#ifdef __sun
#define _XPG4_2
#endif

/* nagios plugins basic includes */
#include "common.h"
#include "netutils.h"
#include "utils.h"

#if HAVE_SYS_SOCKIO_H
#include <sys/sockio.h>
#endif
#include <arpa/inet.h>
#include <ctype.h>
#include <errno.h>
#include <float.h>
#include <net/if.h>
#include <netdb.h>
#include <netinet/icmp6.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip6.h>
#include <netinet/ip_icmp.h>
#include <signal.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>

/* sometimes undefined system macros (quite a few, actually) */
#ifndef MAXTTL
#define MAXTTL 255
#endif
#ifndef INADDR_NONE
#define INADDR_NONE (in_addr_t)(-1)
#endif

#ifndef SOL_IP
#define SOL_IP 0
#endif

/* we bundle these in one #ifndef, since they're all from BSD */
/* Put individual #ifndef's around those that bother you */
#ifndef ICMP_UNREACH_NET_UNKNOWN
#define ICMP_UNREACH_NET_UNKNOWN 6
#define ICMP_UNREACH_HOST_UNKNOWN 7
#define ICMP_UNREACH_ISOLATED 8
#define ICMP_UNREACH_NET_PROHIB 9
#define ICMP_UNREACH_HOST_PROHIB 10
#define ICMP_UNREACH_TOSNET 11
#define ICMP_UNREACH_TOSHOST 12
#endif
/* tru64 has the ones above, but not these */
#ifndef ICMP_UNREACH_FILTER_PROHIB
#define ICMP_UNREACH_FILTER_PROHIB 13
#define ICMP_UNREACH_HOST_PRECEDENCE 14
#define ICMP_UNREACH_PRECEDENCE_CUTOFF 15
#endif

#ifndef DBL_MAX
#define DBL_MAX 9.9999999999e999
#endif

typedef unsigned short range_t; /* type for get_range() -- unimplemented */

typedef struct rta_host {
  unsigned short id;                  /* id in **table, and icmp pkts */
  char *name;                         /* arg used for adding this host */
  char *msg;                          /* icmp error message, if any */
  struct sockaddr_storage saddr_in;   /* the address of this host */
  struct sockaddr_storage error_addr; /* stores address of error replies */
  unsigned long long time_waited;     /* total time waited, in usecs */
  unsigned int icmp_sent, icmp_recv, icmp_lost; /* counters */
  unsigned char icmp_type, icmp_code;           /* type and code from errors */
  unsigned short flags;                         /* control/status flags */
  double rta;                                   /* measured RTA */
  int rta_status;
  double rtmax;  /* max rtt */
  double rtmin;  /* min rtt */
  double jitter; /* measured jitter */
  int jitter_status;
  double jitter_max; /* jitter rtt */
  double jitter_min; /* jitter rtt */
  double EffectiveLatency;
  double mos; /* Mean opinion score */
  int mos_status;
  double score; /* score */
  int score_status;
  u_int last_tdiff;
  u_int last_icmp_seq; /* Last ICMP_SEQ to check out of order pkts */
  unsigned char pl;    /* measured packet loss */
  int pl_status;
  struct rta_host *next; /* linked list */
  int order_status;
} rta_host;

#define FLAG_LOST_CAUSE 0x01 /* decidedly dead target. */

/* threshold structure. all values are maximum allowed, exclusive */
typedef struct threshold {
  unsigned char pl; /* max allowed packet loss in percent */
  unsigned int rta; /* roundtrip time average, microseconds */
  double jitter;    /* jitter time average, microseconds */
  double mos;       /* MOS */
  double score;     /* Score */
} threshold;

/* the data structure */
typedef struct icmp_ping_data {
  struct timeval stime; /* timestamp (saved in protocol struct as well) */
  unsigned short ping_id;
} icmp_ping_data;

typedef union ip_hdr {
  struct ip ip;
  struct ip6_hdr ip6;
} ip_hdr;

typedef union icmp_packet {
  void *buf;
  struct icmp *icp;
  struct icmp6_hdr *icp6;
  u_short *cksum_in;
} icmp_packet;

/* the different modes of this program are as follows:
 * MODE_RTA: send all packets no matter what (mimic check_icmp and check_ping)
 * MODE_HOSTCHECK: Return immediately upon any sign of life
 *                 In addition, sends packets to ALL addresses assigned
 *                 to this host (as returned by gethostbyname() or
 *                 gethostbyaddr() and expects one host only to be checked at
 *                 a time.  Therefore, any packet response what so ever will
 *                 count as a sign of life, even when received outside
 *                 crit.rta limit. Do not misspell any additional IP's.
 * MODE_ALL:  Requires packets from ALL requested IP to return OK (default).
 * MODE_ICMP: implement something similar to check_icmp (MODE_RTA without
 *            tcp and udp args does this)
 */
#define MODE_RTA 0
#define MODE_HOSTCHECK 1
#define MODE_ALL 2
#define MODE_ICMP 3

/* the different ping types we can do */
/* TODO: investigate ARP ping as well */
#define HAVE_ICMP 1
#define HAVE_UDP 2
#define HAVE_TCP 4
#define HAVE_ARP 8

#define MIN_PING_DATA_SIZE sizeof(struct icmp_ping_data)
#define MAX_IP_PKT_SIZE 65536 /* (theoretical) max IP packet size */
#define IP_HDR_SIZE 20
#define MAX_PING_DATA (MAX_IP_PKT_SIZE - IP_HDR_SIZE - ICMP_MINLEN)
#define DEFAULT_PING_DATA_SIZE (MIN_PING_DATA_SIZE + 44)

/* various target states */
#define TSTATE_INACTIVE 0x01 /* don't ping this host anymore */
#define TSTATE_WAITING 0x02  /* unanswered packets on the wire */
#define TSTATE_ALIVE 0x04    /* target is alive (has answered something) */
#define TSTATE_UNREACH 0x08

/* prototypes */
void print_help(void);
void print_usage(void);
static u_int get_timevar(const char *);
static u_int get_timevaldiff(struct timeval *, struct timeval *);
static in_addr_t get_ip_address(const char *);
static int wait_for_reply(int, u_int);
static int recvfrom_wto(int, void *, unsigned int, struct sockaddr *, u_int *,
                        struct timeval *);
static int send_icmp_ping(int, struct rta_host *);
static int get_threshold(char *str, threshold *th);
static int get_threshold2(char *str, threshold *, threshold *, int type);
static void run_checks(void);
static void set_source_ip(char *);
static int add_target(char *);
static int add_target_ip(char *, struct sockaddr_storage *);
static int handle_random_icmp(unsigned char *, struct sockaddr_storage *);
static unsigned short icmp_checksum(unsigned short *, int);
static void finish(int);
static void crash(const char *, ...);

/* external */
extern int optind, opterr, optopt;
extern char *optarg;
extern char **environ;

/* global variables */
static struct rta_host **table, *cursor, *list;
static threshold crit = {80, 500000}, warn = {40, 200000};
static int mode, protocols, sockets, debug = 0, timeout = 10;
static unsigned short icmp_data_size = DEFAULT_PING_DATA_SIZE;
static unsigned short icmp_pkt_size = DEFAULT_PING_DATA_SIZE + ICMP_MINLEN;

static unsigned int icmp_sent = 0, icmp_recv = 0, icmp_lost = 0;
#define icmp_pkts_en_route (icmp_sent - (icmp_recv + icmp_lost))
static unsigned short targets_down = 0, targets = 0, packets = 0;
#define targets_alive (targets - targets_down)
static unsigned int retry_interval, pkt_interval, target_interval;
static int icmp_sock, tcp_sock, udp_sock, status = STATE_OK;
static pid_t pid;
static struct timezone tz;
static struct timeval prog_start;
static unsigned long long max_completion_time = 0;
static unsigned char ttl = 0; /* outgoing ttl */
static unsigned int warn_down = 1,
                    crit_down = 1; /* host down threshold values */
static int min_hosts_alive = -1;
float pkt_backoff_factor = 1.5;
float target_backoff_factor = 1.5;
int rta_mode = 0;
int pl_mode = 0;
int jitter_mode = 0;
int score_mode = 0;
int mos_mode = 0;
int order_mode = 0;

/* code start */
static void crash(const char *fmt, ...) {
  va_list ap;

  printf("%s: ", progname);

  va_start(ap, fmt);
  vprintf(fmt, ap);
  va_end(ap);

  if (errno) {
    printf(": %s", strerror(errno));
  }

  puts("");

  exit(3);
}

static const char *get_icmp_error_msg(unsigned char icmp_type,
                                      unsigned char icmp_code) {
  const char *msg = "unreachable";

  if (debug > 1) {
    printf("get_icmp_error_msg(%u, %u)\n", icmp_type, icmp_code);
  }
  switch (icmp_type) {
  case ICMP_UNREACH:
    switch (icmp_code) {
    case ICMP_UNREACH_NET:
      msg = "Net unreachable";
      break;

    case ICMP_UNREACH_HOST:
      msg = "Host unreachable";
      break;

    case ICMP_UNREACH_PROTOCOL:
      msg = "Protocol unreachable (firewall?)";
      break;

    case ICMP_UNREACH_PORT:
      msg = "Port unreachable (firewall?)";
      break;

    case ICMP_UNREACH_NEEDFRAG:
      msg = "Fragmentation needed";
      break;

    case ICMP_UNREACH_SRCFAIL:
      msg = "Source route failed";
      break;

    case ICMP_UNREACH_ISOLATED:
      msg = "Source host isolated";
      break;

    case ICMP_UNREACH_NET_UNKNOWN:
      msg = "Unknown network";
      break;

    case ICMP_UNREACH_HOST_UNKNOWN:
      msg = "Unknown host";
      break;

    case ICMP_UNREACH_NET_PROHIB:
      msg = "Network denied (firewall?)";
      break;

    case ICMP_UNREACH_HOST_PROHIB:
      msg = "Host denied (firewall?)";
      break;

    case ICMP_UNREACH_TOSNET:
      msg = "Bad TOS for network (firewall?)";
      break;

    case ICMP_UNREACH_TOSHOST:
      msg = "Bad TOS for host (firewall?)";
      break;

    case ICMP_UNREACH_FILTER_PROHIB:
      msg = "Prohibited by filter (firewall)";
      break;

    case ICMP_UNREACH_HOST_PRECEDENCE:
      msg = "Host precedence violation";
      break;

    case ICMP_UNREACH_PRECEDENCE_CUTOFF:
      msg = "Precedence cutoff";
      break;

    default:
      msg = "Invalid code";
      break;
    }
    break;

  case ICMP_TIMXCEED:
    /* really 'out of reach', or non-existant host behind a router serving */
    /* two different subnets */
    switch (icmp_code) {
    case ICMP_TIMXCEED_INTRANS:
      msg = "Time to live exceeded in transit";
      break;

    case ICMP_TIMXCEED_REASS:
      msg = "Fragment reassembly time exceeded";
      break;

    default:
      msg = "Invalid code";
      break;
    }
    break;

  case ICMP_SOURCEQUENCH:
    msg = "Transmitting too fast";
    break;

  case ICMP_REDIRECT:
    msg = "Redirect (change route)";
    break;

  case ICMP_PARAMPROB:
    msg = "Bad IP header (required option absent)";
    break;

  /* the following aren't error messages, so ignore */
  case ICMP_TSTAMP:
  case ICMP_TSTAMPREPLY:
  case ICMP_IREQ:
  case ICMP_IREQREPLY:
  case ICMP_MASKREQ:
  case ICMP_MASKREPLY:
  default:
    msg = "";
    break;
  }

  return msg;
}

static int handle_random_icmp(unsigned char *packet,
                              struct sockaddr_storage *addr) {
  struct icmp p, sent_icmp;
  struct rta_host *host = NULL;

  memcpy(&p, packet, sizeof(p));
  if (p.icmp_type == ICMP_ECHO && ntohs(p.icmp_id) == pid) {
    /* echo request from us to us (pinging localhost) */
    return 0;
  }

  if (debug) {
    printf("handle_random_icmp(%p, %p)\n", (void *)&p, (void *)addr);
  }

  /* only handle a few types, since others can't possibly be replies to
   * us in a sane network (if it is anyway, it will be counted as lost
   * at summary time, but not as quickly as a proper response */
  /* TIMXCEED can be an unreach from a router with multiple IP's which
   * serves two different subnets on the same interface and a dead host
   * on one net is pinged from the other. The router will respond to
   * itself and thus set TTL=0 so as to not loop forever.  Even when
   * TIMXCEED actually sends a proper icmp response we will have passed
   * too many hops to have a hope of reaching it later, in which case it
   * indicates overconfidence in the network, poor routing or both. */
  if (p.icmp_type != ICMP_UNREACH && p.icmp_type != ICMP_TIMXCEED &&
      p.icmp_type != ICMP_SOURCEQUENCH && p.icmp_type != ICMP_PARAMPROB) {
    return 0;
  }

  /* might be for us. At least it holds the original package (according
   * to RFC 792). If it isn't, just ignore it */
  memcpy(&sent_icmp, packet + 28, sizeof(sent_icmp));
  if (sent_icmp.icmp_type != ICMP_ECHO || ntohs(sent_icmp.icmp_id) != pid ||
      ntohs(sent_icmp.icmp_seq) >= targets * packets) {
    if (debug) {
      printf("Packet is no response to a packet we sent\n");
    }
    return 0;
  }

  /* it is indeed a response for us */
  host = table[ntohs(sent_icmp.icmp_seq) / packets];
  if (debug) {
    char address[address_length(address_family)];
    parse_address_string(address_family, addr, address, sizeof(address));
    printf("Received \"%s\" from %s for ICMP ECHO sent to %s.\n",
           get_icmp_error_msg(p.icmp_type, p.icmp_code), address, host->name);
  }

  icmp_lost++;
  host->icmp_lost++;
  /* don't spend time on lost hosts any more */
  if (host->flags & FLAG_LOST_CAUSE) {
    return 0;
  }

  /* source quench means we're sending too fast, so increase the */
  /* interval and mark this packet lost */
  if (p.icmp_type == ICMP_SOURCEQUENCH) {
    pkt_interval *= pkt_backoff_factor;
    target_interval *= target_backoff_factor;
  } else {
    targets_down++;
    host->flags |= FLAG_LOST_CAUSE;
  }
  host->icmp_type = p.icmp_type;
  host->icmp_code = p.icmp_code;
  host->error_addr = *addr;

  return 0;
}

int main(int argc, char **argv) {
  int i;
  char *ptr;
  char *bind_address = NULL;
  long int arg;
  int icmp_sockerrno, udp_sockerrno, tcp_sockerrno;
  int result;
  struct rta_host *host;
#ifdef HAVE_SIGACTION
  struct sigaction sig_action;
#endif
#ifdef SO_TIMESTAMP
  int on = 1;
#endif

  setlocale(LC_ALL, "");
  bindtextdomain(PACKAGE, LOCALEDIR);
  textdomain(PACKAGE);

  /* print a helpful error message if geteuid != 0 */
  np_warn_if_not_root();

  /* Set default address_family to AF_INET (IPv4) */
  /* It will be changed to AF_INET6 later if required */
  address_family = AF_INET;

  /* Set default ip_protocol to IPPROTO_ICMP (IPv4) */
  /* It will be changed to IPPROTO_ICMPV6 later if required */
  int ip_protocol = IPPROTO_ICMP;

  /* we only need to be setsuid when we get the sockets, so do
   * that before pointer magic (esp. on network data) */
  icmp_sockerrno = udp_sockerrno = tcp_sockerrno = sockets = 0;

  /* get calling name the old-fashioned way for portability instead
   * of relying on the glibc-ism __progname */
  ptr = strrchr(argv[0], '/');
  if (ptr) {
    progname = &ptr[1];
  } else {
    progname = argv[0];
  }

  /* now set defaults. Use progname to set them initially (allows for
   * superfast check_host program when target host is up */
  cursor = list = NULL;
  table = NULL;

  mode = MODE_RTA;
  /* Default critical thresholds */
  crit.rta = 500000;
  crit.pl = 80;
  crit.jitter = 50;
  crit.mos = 3;
  crit.score = 70;
  /* Default warning thresholds */
  warn.rta = 200000;
  warn.pl = 40;
  warn.jitter = 40;
  warn.mos = 3.5;
  warn.score = 80;

  protocols = HAVE_ICMP | HAVE_UDP | HAVE_TCP;
  pkt_interval = 80000; /* 80 msec packet interval by default */
  packets = 5;

  if (!strcmp(progname, "check_icmp") || !strcmp(progname, "check_ping")) {
    mode = MODE_ICMP;
    protocols = HAVE_ICMP;
  } else if (!strcmp(progname, "check_host")) {
    mode = MODE_HOSTCHECK;
    pkt_interval = 1000000;
    packets = 5;
    crit.rta = warn.rta = 1000000;
    crit.pl = warn.pl = 100;
  } else if (!strcmp(progname, "check_rta_multi")) {
    mode = MODE_ALL;
    target_interval = 0;
    pkt_interval = 50000;
    packets = 5;
  }

  /* parse the arguments */
  for (i = 1; i < argc; i++) {
    while ((arg = getopt(argc, argv,
                         "vhVw:c:n:p:t:H:s:i:b:I:l:m:P:R:J:S:M:O:64")) != EOF) {
      long size;
      switch (arg) {
      case 'v':
        debug++;
        break;

      case 'b':
        size = strtol(optarg, NULL, 0);
        if (size >= (sizeof(struct icmp) + sizeof(struct icmp_ping_data)) &&
            size < MAX_PING_DATA) {
          icmp_data_size = size;
          icmp_pkt_size = size + ICMP_MINLEN;
        } else {
          usage_va("ICMP data length must be between: %d and %d",
                   sizeof(struct icmp) + sizeof(struct icmp_ping_data),
                   MAX_PING_DATA - 1);
        }
        break;

      case 'i':
        pkt_interval = get_timevar(optarg);
        break;

      case 'I':
        target_interval = get_timevar(optarg);
        break;

      case 'w':
        get_threshold(optarg, &warn);
        break;

      case 'c':
        get_threshold(optarg, &crit);
        break;

      case 'n':
      case 'p':
        packets = strtoul(optarg, NULL, 0);
        break;

      case 't':
        timeout = strtoul(optarg, NULL, 0);
        if (!timeout) {
          timeout = 10;
        }
        break;

      case '4':
        address_family = AF_INET;
        ip_protocol = IPPROTO_ICMP;
        break;

      case '6':
#ifdef USE_IPV6
        address_family = AF_INET6;
        ip_protocol = IPPROTO_ICMPV6;
#else
        usage(_("IPv6 support not available\n"));
#endif
        break;

      case 'H':
        add_target(optarg);
        break;

      case 'l':
        ttl = (unsigned char)strtoul(optarg, NULL, 0);
        break;

      case 'm':
        min_hosts_alive = (int)strtoul(optarg, NULL, 0);
        break;

      case 'd':
        /* implement later, for cluster checks */
        warn_down = (unsigned char)strtoul(optarg, &ptr, 0);
        if (ptr) {
          crit_down = (unsigned char)strtoul(ptr + 1, NULL, 0);
        }
        break;

      case 's':
        /* specify source IP address */
        bind_address = optarg;
        break;

      case 'V':
        /* version */
        print_revision(progname, NP_VERSION);
        exit(STATE_OK);

      case 'h':
        /* help */
        print_help();
        exit(STATE_OK);

      case 'R':
        /* RTA mode */
        get_threshold2(optarg, &warn, &crit, 1);
        rta_mode = 1;
        break;

      case 'P':
        /* packet loss mode */
        get_threshold2(optarg, &warn, &crit, 2);
        pl_mode = 1;
        break;

      case 'J':
        /* packet loss mode */
        get_threshold2(optarg, &warn, &crit, 3);
        jitter_mode = 1;
        break;

      case 'M':
        /* MOS mode */
        get_threshold2(optarg, &warn, &crit, 4);
        mos_mode = 1;
        break;

      case 'S':
        /* score mode */
        get_threshold2(optarg, &warn, &crit, 5);
        score_mode = 1;
        break;

      case 'O':
        /* out of order mode */
        order_mode = 1;
        break;
      }
    }
  }

  if ((icmp_sock = socket(address_family, SOCK_RAW, ip_protocol)) != -1) {
    sockets |= HAVE_ICMP;
  } else {
    icmp_sockerrno = errno;
  }

  if (bind_address != NULL) {
    set_source_ip(bind_address);
  }

  /* now drop privileges (no effect if not setsuid or geteuid() == 0) */
  setuid(getuid());

#ifdef SO_TIMESTAMP
  if (setsockopt(icmp_sock, SOL_SOCKET, SO_TIMESTAMP, &on, sizeof(on))) {
    if (debug) {
      printf("Warning: no SO_TIMESTAMP support\n");
    }
  }
#endif /* SO_TIMESTAMP */

  /* POSIXLY_CORRECT might break things, so unset it (the portable way) */
  environ = NULL;

  /* use the pid to mark packets as ours */
  /* Some systems have 32-bit pid_t so mask off only 16 bits */
  pid = getpid() & 0xffff;
  /* printf("pid = %u\n", pid); */

  /* Parse extra opts if any */
  argv = np_extra_opts(&argc, argv, progname);

  /* support "--help" and "--version" */
  if (argc == 2) {
    if (!strcmp(argv[1], "--help")) {
      strcpy(argv[1], "-h");
    }
    if (!strcmp(argv[1], "--version")) {
      strcpy(argv[1], "-V");
    }
  }

  if (debug) {
    printf("address_family: %i (IPv4 = 2; IPv6 = 10)\n", address_family);
  }

  argv = &argv[optind];
  while (*argv) {
    add_target(*argv);
    argv++;
  }
  if (!targets) {
    errno = 0;
    crash("No hosts to check");
    exit(3);
  }

  if (!sockets) {
    if (icmp_sock == -1) {
      errno = icmp_sockerrno;
      crash("Failed to obtain ICMP socket");
      return -1;
    }
    /* if(udp_sock == -1) { */
    /* 	errno = icmp_sockerrno; */
    /* 	crash("Failed to obtain UDP socket"); */
    /* 	return -1; */
    /* } */
    /* if(tcp_sock == -1) { */
    /* 	errno = icmp_sockerrno; */
    /* 	crash("Failed to obtain TCP socket"); */
    /* 	return -1; */
    /* } */
  }
  if (!ttl) {
    ttl = 64;
  }

  if (icmp_sock) {
    result = setsockopt(icmp_sock, SOL_IP, IP_TTL, &ttl, sizeof(ttl));
    if (debug) {
      if (result == -1) {
        printf("setsockopt failed\n");
      } else {
        printf("ttl set to %u\n", ttl);
      }
    }
  }

  /* Users should be able to give whatever thresholds they want */
  /* (nothing will break if they do), but some plugin maintainer */
  /* will probably add some printf() thing here later, so it might be */
  /* best to at least show them where to do it */
  if (warn.pl > crit.pl) {
    warn.pl = crit.pl;
  }
  if (warn.rta > crit.rta) {
    warn.rta = crit.rta;
  }
  if (warn_down > crit_down) {
    crit_down = warn_down;
  }
  if (warn.jitter > crit.jitter) {
    crit.jitter = warn.jitter;
  }
  if (warn.mos < crit.mos) {
    warn.mos = crit.mos;
  }
  if (warn.score < crit.score) {
    warn.score = crit.score;
  }

#ifdef HAVE_SIGACTION
  sig_action.sa_sigaction = NULL;
  sig_action.sa_handler = finish;
  sigfillset(&sig_action.sa_mask);
  sig_action.sa_flags = SA_NODEFER | SA_RESTART;
  sigaction(SIGINT, &sig_action, NULL);
  sigaction(SIGHUP, &sig_action, NULL);
  sigaction(SIGTERM, &sig_action, NULL);
  sigaction(SIGALRM, &sig_action, NULL);
#else  /* HAVE_SIGACTION */
  signal(SIGINT, finish);
  signal(SIGHUP, finish);
  signal(SIGTERM, finish);
  signal(SIGALRM, finish);
#endif /* HAVE_SIGACTION */
  if (debug) {
    printf("Setting alarm timeout to %u seconds\n", timeout);
  }
  alarm(timeout);

  /* make sure we don't wait any longer than necessary */
  gettimeofday(&prog_start, &tz);
  max_completion_time =
      ((targets * packets * pkt_interval) + (targets * target_interval)) +
      (targets * packets * crit.rta) + crit.rta;

  if (debug) {
    printf("packets: %u, targets: %u\n"
           "target_interval: %0.3f, pkt_interval %0.3f\n"
           "crit.rta: %0.3f\n"
           "max_completion_time: %0.3f\n",
           packets, targets, (float)target_interval / 1000,
           (float)pkt_interval / 1000, (float)crit.rta / 1000,
           (float)max_completion_time / 1000);
  }

  if (debug) {
    if (max_completion_time > (u_int)timeout * 1000000) {
      printf("max_completion_time: %llu  timeout: %u\n", max_completion_time,
             timeout);
      printf("Timout must be at least %llu\n",
             max_completion_time / 1000000 + 1);
    }
  }

  if (debug) {
    printf("crit = {%u, %u%%}, warn = {%u, %u%%}\n", crit.rta, crit.pl,
           warn.rta, warn.pl);
    printf("pkt_interval: %u  target_interval: %u  retry_interval: %u\n",
           pkt_interval, target_interval, retry_interval);
    printf("icmp_pkt_size: %u  timeout: %u\n", icmp_pkt_size, timeout);
  }

  if (packets > 20) {
    errno = 0;
    crash("packets is > 20 (%d)", packets);
  }

  if (min_hosts_alive < -1) {
    errno = 0;
    crash("minimum alive hosts is negative (%i)", min_hosts_alive);
  }

  host = list;

  table = (struct rta_host **)malloc(sizeof(struct rta_host **) * targets);

  i = 0;
  while (host) {
    host->id = i * packets;
    table[i] = host;
    host = host->next;
    i++;
  }

  run_checks();

  errno = 0;
  finish(0);

  return (0); 
}

static void run_checks() {
  u_int i, t, result;
  u_int final_wait, time_passed;

  /* this loop might actually violate the pkt_interval or target_interval
   * settings, but only if there aren't any packets on the wire which
   * indicates that the target can handle an increased packet rate */
  for (i = 0; i < packets; i++) {
    for (t = 0; t < targets; t++) {
      /* don't send useless packets */
      if (!targets_alive) {
        finish(0);
      }
      if (table[t]->flags & FLAG_LOST_CAUSE) {
        if (debug) {
          printf("%s is a lost cause. not sending any more\n", table[t]->name);
        }
        continue;
      }
      /* we're still in the game, so send next packet */
      (void)send_icmp_ping(icmp_sock, table[t]);
      result = wait_for_reply(icmp_sock, target_interval);
    }
    result = wait_for_reply(icmp_sock, pkt_interval * targets);
  }

  if (icmp_pkts_en_route && targets_alive) {
    time_passed = get_timevaldiff(NULL, NULL);
    final_wait = max_completion_time - time_passed;

    if (debug) {
      printf("time_passed: %u  final_wait: %u  max_completion_time: %llu\n",
             time_passed, final_wait, max_completion_time);
    }
    if (time_passed > max_completion_time) {
      if (debug) {
        printf("Time passed. Finishing up\n");
      }
      finish(0);
    }

    /* catch the packets that might come in within the timeframe, but
     * haven't yet */
    if (debug) {
      printf("Waiting for %u micro-seconds (%0.3f msecs)\n", final_wait,
             (float)final_wait / 1000);
    }
    result = wait_for_reply(icmp_sock, final_wait);
  }
}

/* Response Structure: */
/*	IPv4: */
/*		ip header (total length)   : 20 bytes */
/*	IPv6: */
/*		ip header (payload length) : 40 bytes */
/*	Both: */
/*		icmp header                : 28 bytes */
/*		icmp echo reply            : the rest */
static int wait_for_reply(int sock, u_int t) {
  int n, hlen;
  static unsigned char buf[4096];
  struct sockaddr_storage resp_addr;
  union ip_hdr *ip;
  union icmp_packet packet;
  struct rta_host *host;
  struct icmp_ping_data data;
  struct timeval wait_start, now;
  u_int tdiff, i, per_pkt_wait;
  double jitter_tmp;

  if (!(packet.buf = malloc(icmp_pkt_size))) {
    crash("send_icmp_ping(): failed to malloc %d bytes for send buffer",
          icmp_pkt_size);
    return -1; /* might be reached if we're in debug mode */
  }

  memset(packet.buf, 0, icmp_pkt_size);

  /* if we can't listen or don't have anything to listen to, just return */
  if (!t || !icmp_pkts_en_route) {
    free(packet.buf);
    return 0;
  }

  gettimeofday(&wait_start, &tz);

  i = t;
  per_pkt_wait = t / icmp_pkts_en_route;
  while (icmp_pkts_en_route && get_timevaldiff(&wait_start, NULL) < i) {
    t = per_pkt_wait;

    /* wrap up if all targets are declared dead */
    if (!targets_alive ||
        get_timevaldiff(&prog_start, NULL) >= max_completion_time ||
        (mode == MODE_HOSTCHECK && targets_down)) {
      finish(0);
    }

    /* reap responses until we hit a timeout */
    n = recvfrom_wto(sock, buf, sizeof(buf), (struct sockaddr *)&resp_addr, &t,
                     &now);
    if (!n) {
      if (debug > 1) {
        printf("recvfrom_wto() timed out during a %u usecs wait\n",
               per_pkt_wait);
      }
      continue; /* timeout for this one, so keep trying */
    }

    if (n < 0) {
      if (debug) {
        printf("recvfrom_wto() returned errors\n");
      }
      return n;
    }

    if (debug > 1) {
      ip = (union ip_hdr *)buf;
      char address[address_length(address_family)];
      parse_address_string(address_family, &resp_addr, address,
                           sizeof(address));
      if (address_family == AF_INET) {
        printf("received %u bytes from %s\n", ntohs(ip->ip.ip_len), address);
      } else if (address_family == AF_INET6) {
        printf("received %u bytes from %s\n", ntohs(ip->ip6.ip6_plen), address);
      }
    }

    /* IPv6 doesn't have a header length, it's a payload length */
    if (address_family == AF_INET) {
      hlen = ip->ip.ip_hl << 2;
    } else if (address_family == AF_INET6) {
      hlen = 0;
    }

    if (n < (hlen + ICMP_MINLEN)) {
      char address[address_length(address_family)];
      parse_address_string(address_family, &resp_addr, address,
                           sizeof(address));
      crash("received packet too short for ICMP (%d bytes, expected %d) from "
            "%s\n",
            n, hlen + icmp_pkt_size, address);
    }

    /* check the response */
    memcpy(packet.buf, buf + hlen, icmp_pkt_size);
    if ((address_family == AF_INET &&
         (ntohs(packet.icp->icmp_id) != pid ||
          packet.icp->icmp_type != ICMP_ECHOREPLY ||
          ntohs(packet.icp->icmp_seq) >= targets * packets)) ||
        (address_family == AF_INET6 &&
         (ntohs(packet.icp6->icmp6_id) != pid ||
          packet.icp6->icmp6_type != ICMP6_ECHO_REPLY ||
          ntohs(packet.icp6->icmp6_seq) >= targets * packets))) {
      if (debug > 2) {
        printf("not a proper ICMP_ECHOREPLY\n");
      }
      handle_random_icmp(buf + hlen, &resp_addr);
      continue;
    }

    /* this is indeed a valid response */
    if (address_family == AF_INET) {
      memcpy(&data, packet.icp->icmp_data, sizeof(data));
      if (debug > 2) {
        printf("ICMP echo-reply of len %lu, id %u, seq %u, cksum 0x%X\n",
               (unsigned long)sizeof(data), ntohs(packet.icp->icmp_id),
               ntohs(packet.icp->icmp_seq), packet.icp->icmp_cksum);
      }
      host = table[ntohs(packet.icp->icmp_seq) / packets];
    } else if (address_family == AF_INET6) {
      memcpy(&data, &packet.icp6->icmp6_dataun.icmp6_un_data8[4], sizeof(data));
      if (debug > 2) {
        printf("ICMP echo-reply of len %lu, id %u, seq %u, cksum 0x%X\n",
               (unsigned long)sizeof(data), ntohs(packet.icp6->icmp6_id),
               ntohs(packet.icp6->icmp6_seq), packet.icp6->icmp6_cksum);
      }
      host = table[ntohs(packet.icp6->icmp6_seq) / packets];
    }

    tdiff = get_timevaldiff(&data.stime, &now);

    if (host->last_tdiff > 0) {
      /* Calculate jitter */
      if (host->last_tdiff > tdiff) {
        jitter_tmp = host->last_tdiff - tdiff;
      } else {
        jitter_tmp = tdiff - host->last_tdiff;
      }
      if (host->jitter == 0) {
        host->jitter = jitter_tmp;
        host->jitter_max = jitter_tmp;
        host->jitter_min = jitter_tmp;
      } else {
        host->jitter += jitter_tmp;
        if (jitter_tmp < host->jitter_min) {
          host->jitter_min = jitter_tmp;
        }
        if (jitter_tmp > host->jitter_max) {
          host->jitter_max = jitter_tmp;
        }
      }

      /* Check if packets in order */
      if (host->last_icmp_seq >= packet.icp->icmp_seq) {
        host->order_status = STATE_CRITICAL;
      }
    }

    host->last_tdiff = tdiff;
    host->last_icmp_seq = packet.icp->icmp_seq;
    host->time_waited += tdiff;
    host->icmp_recv++;
    icmp_recv++;
    if (tdiff > (int)host->rtmax) {
      host->rtmax = tdiff;
    }
    if (tdiff < (int)host->rtmin) {
      host->rtmin = tdiff;
    }

    if (debug) {
      char address[address_length(address_family)];
      parse_address_string(address_family, &resp_addr, address,
                           sizeof(address));
      printf("%0.3f ms rtt from %s, outgoing ttl: %u, incoming ttl: %u, max: "
             "%0.3f, min: %0.3f\n",
             (float)tdiff / 1000, address, ttl, ip->ip.ip_ttl,
             (float)host->rtmax / 1000, (float)host->rtmin / 1000);
    }

    /* if we're in hostcheck mode, exit with limited printouts */
    if (mode == MODE_HOSTCHECK) {
      printf("OK - %s responds to ICMP. Packet %u, rta %0.3fms|"
             "pkt=%u;;0;%u rta=%0.3f;%0.3f;%0.3f;;\n",
             host->name, icmp_recv, (float)tdiff / 1000, icmp_recv, packets,
             (float)tdiff / 1000, (float)warn.rta / 1000,
             (float)crit.rta / 1000);
      exit(STATE_OK);
    }
  }
  return 0;
}

/* the ping functions */
static int send_icmp_ping(int sock, struct rta_host *host) {
  long int len;
  struct icmp_ping_data data;
  struct msghdr hdr;
  struct iovec iov;
  struct timeval tv;
  void *buf = NULL;

  if (sock == -1) {
    errno = 0;
    crash("Attempt to send on bogus socket");
    return -1;
  }

  if (!buf) {
    if (!(buf = malloc(icmp_pkt_size))) {
      crash("send_icmp_ping(): failed to malloc %d bytes for send buffer",
            icmp_pkt_size);
      return -1; /* might be reached if we're in debug mode */
    }
  }

  memset(buf, 0, icmp_pkt_size);

  if ((gettimeofday(&tv, &tz)) == -1) {
    free(buf);
    return -1;
  }

  data.ping_id = 10; /* host->icmp.icmp_sent; */

  memcpy(&data.stime, &tv, sizeof(tv));

  if (address_family == AF_INET) {
    struct icmp *icp = (struct icmp *)buf;
    memcpy(&icp->icmp_data, &data, sizeof(data));
    icp->icmp_type = ICMP_ECHO;
    icp->icmp_code = 0;
    icp->icmp_cksum = 0;
    icp->icmp_id = htons(pid);
    icp->icmp_seq = htons(host->id++);
    icp->icmp_cksum = icmp_checksum((unsigned short *)buf, icmp_pkt_size);
    if (debug > 2) {
      printf("Sending ICMPv4 echo-request of len %lu, id %u, seq %u, cksum "
             "0x%X to host %s\n",
             (unsigned long)sizeof(data), ntohs(icp->icmp_id),
             ntohs(icp->icmp_seq), icp->icmp_cksum, host->name);
    }
  } else if (address_family == AF_INET6) {
    struct icmp6_hdr *icp6 = (struct icmp6_hdr *)buf;
    memcpy(&icp6->icmp6_dataun.icmp6_un_data8[4], &data, sizeof(data));
    icp6->icmp6_type = ICMP6_ECHO_REQUEST;
    icp6->icmp6_code = 0;
    icp6->icmp6_cksum = 0;
    icp6->icmp6_id = htons(pid);
    icp6->icmp6_seq = htons(host->id++);
    /* checksum is calculated automatically */
    if (debug > 2) {
      printf("Sending ICMPv6 echo-request of len %lu, id %u, seq %u, cksum "
             "0x%X to host %s\n",
             (unsigned long)sizeof(data), ntohs(icp6->icmp6_id),
             ntohs(icp6->icmp6_seq), icp6->icmp6_cksum, host->name);
    }
  }

  memset(&iov, 0, sizeof(iov));
  iov.iov_base = buf;
  iov.iov_len = icmp_pkt_size;
  memset(&hdr, 0, sizeof(hdr));
  hdr.msg_name = (struct sockaddr *)&host->saddr_in;
  hdr.msg_namelen = sizeof(struct sockaddr_storage);
  hdr.msg_iov = &iov;
  hdr.msg_iovlen = 1;

  errno = 0;

/* MSG_CONFIRM is a linux thing and only available on linux kernels >= 2.3.15,
 * see send(2) */
#ifdef MSG_CONFIRM
  len = sendmsg(sock, &hdr, MSG_CONFIRM);
#else
  len = sendmsg(sock, &hdr, 0);
#endif

  free(buf);

  if (len < 0 || (unsigned int)len != icmp_pkt_size) {
    if (debug) {
      char address[address_length(address_family)];
      parse_address_string(address_family,
                           (struct sockaddr_storage *)&host->saddr_in, address,
                           sizeof(address));
      printf("Failed to send ping to %s = %s\n", address, strerror(errno));
    }
    errno = 0;
    return -1;
  }

  icmp_sent++;
  host->icmp_sent++;

  return 0;
}

static int recvfrom_wto(int sock, void *buf, unsigned int len,
                        struct sockaddr *saddr, u_int *timo,
                        struct timeval *tv) {
  u_int slen;
  int n, ret;
  struct timeval to, then, now;
  fd_set rd, wr;
  char ans_data[4096];
  struct msghdr hdr;
  struct iovec iov;
#ifdef SO_TIMESTAMP
  struct cmsghdr *chdr;
#endif

  if (!*timo) {
    if (debug)
      printf("*timo is not\n");
    return 0;
  }

  to.tv_sec = *timo / 1000000;
  to.tv_usec = (*timo - (to.tv_sec * 1000000));

  FD_ZERO(&rd);
  FD_ZERO(&wr);
  FD_SET(sock, &rd);
  errno = 0;
  gettimeofday(&then, &tz);
  n = select(sock + 1, &rd, &wr, NULL, &to);
  if (n < 0) {
    crash("select() in recvfrom_wto");
  }
  gettimeofday(&now, &tz);
  *timo = get_timevaldiff(&then, &now);

  if (!n) {
    /* timeout */
    return 0;
  }

  slen = sizeof(struct sockaddr_storage);

  memset(&iov, 0, sizeof(iov));
  iov.iov_base = buf;
  iov.iov_len = len;

  memset(&hdr, 0, sizeof(hdr));
  hdr.msg_name = saddr;
  hdr.msg_namelen = slen;
  hdr.msg_iov = &iov;
  hdr.msg_iovlen = 1;
#ifdef HAVE_MSGHDR_MSG_CONTROL
  hdr.msg_control = ans_data;
  hdr.msg_controllen = sizeof(ans_data);
#endif

  ret = recvmsg(sock, &hdr, 0);
#ifdef SO_TIMESTAMP
  for (chdr = CMSG_FIRSTHDR(&hdr); chdr; chdr = CMSG_NXTHDR(&hdr, chdr)) {
    if (chdr->cmsg_level == SOL_SOCKET && chdr->cmsg_type == SO_TIMESTAMP &&
        chdr->cmsg_len >= CMSG_LEN(sizeof(struct timeval))) {
      memcpy(tv, CMSG_DATA(chdr), sizeof(*tv));
      break;
    }
  }
#endif /* SO_TIMESTAMP */

  if (!chdr) {
    gettimeofday(tv, &tz);
  }
  return (ret);
}

static void finish(int sig) {
  u_int i = 0;
  unsigned char pl;
  double rta;
  struct rta_host *host;
  const char *status_string[] = {"OK", "WARNING", "CRITICAL", "UNKNOWN",
                                 "DEPENDENT"};
  int hosts_ok = 0;
  int hosts_warn = 0;
  int this_status;
  double R;

  alarm(0);
  if (debug > 1) {
    printf("finish(%d) called\n", sig);
  }

  if (icmp_sock != -1) {
    close(icmp_sock);
  }
  if (udp_sock != -1) {
    close(udp_sock);
  }
  if (tcp_sock != -1) {
    close(tcp_sock);
  }

  if (debug) {
    printf("icmp_sent: %u  icmp_recv: %u  icmp_lost: %u\n", icmp_sent,
           icmp_recv, icmp_lost);
    printf("targets: %u  targets_alive: %u\n", targets, targets_alive);
  }

  /* iterate thrice to calculate values, give output, and print perfparse */
  status = STATE_OK;
  host = list;
  while (host) {
    if (!host->icmp_recv) {
      /* rta 0 is ofcourse not entirely correct, but will still show up
       * conspicuosly as missing entries in perfparse and cacti */
      pl = 100;
      rta = 0;
      status = STATE_CRITICAL;
      /* up the down counter if not already counted */
      if (!(host->flags & FLAG_LOST_CAUSE) && targets_alive) {
        targets_down++;
      }
    } else {
      pl = ((host->icmp_sent - host->icmp_recv) * 100) / host->icmp_sent;
      rta = (double)host->time_waited / host->icmp_recv;
    }
    if (host->icmp_recv > 1) {
      host->jitter = (host->jitter / (host->icmp_recv - 1) / 1000);
      host->EffectiveLatency = (rta / 1000) + host->jitter * 2 + 10;
      if (host->EffectiveLatency < 160) {
        R = 93.2 - (host->EffectiveLatency / 40);
      } else {
        R = 93.2 - ((host->EffectiveLatency - 120) / 10);
      }
      R = R - (pl * 2.5);
      if (R < 0) {
        R = 0;
      }
      host->score = R;
      host->mos = 1 + ((0.035) * R) + ((.000007) * R * (R - 60) * (100 - R));
    } else {
      host->jitter = 0;
      host->jitter_min = 0;
      host->jitter_max = 0;
      host->mos = 0;
    }
    host->pl = pl;
    host->rta = rta;

    /* if no new mode selected, use old schema */
    if (!rta_mode && !pl_mode && !jitter_mode && !score_mode && !mos_mode &&
        !order_mode) {
      rta_mode = 1;
      pl_mode = 1;
    }

    /* Check which mode is on and do the warn / Crit stuff */
    if (rta_mode) {
      if (rta >= crit.rta) {
        this_status = STATE_CRITICAL;
        status = STATE_CRITICAL;
        host->rta_status = STATE_CRITICAL;
      } else if (status != STATE_CRITICAL && (rta >= warn.rta)) {
        this_status = (this_status <= STATE_WARNING ? STATE_WARNING : this_status);
        status = STATE_WARNING;
        host->rta_status = STATE_WARNING;
      }
    }
    if (pl_mode) {
      if (pl >= crit.pl) {
        this_status = STATE_CRITICAL;
        status = STATE_CRITICAL;
        host->pl_status = STATE_CRITICAL;
      } else if (status != STATE_CRITICAL && (pl >= warn.pl)) {
        this_status = (this_status <= STATE_WARNING ? STATE_WARNING : this_status);
        status = STATE_WARNING;
        host->pl_status = STATE_WARNING;
      }
    }
    if (jitter_mode) {
      if (host->jitter >= crit.jitter) {
        this_status = STATE_CRITICAL;
        status = STATE_CRITICAL;
        host->jitter_status = STATE_CRITICAL;
      } else if (status != STATE_CRITICAL && (host->jitter >= warn.jitter)) {
        this_status = (this_status <= STATE_WARNING ? STATE_WARNING : this_status);
        status = STATE_WARNING;
        host->jitter_status = STATE_WARNING;
      }
    }
    if (mos_mode) {
      if (host->mos <= crit.mos) {
        this_status = STATE_CRITICAL;
        status = STATE_CRITICAL;
        host->mos_status = STATE_CRITICAL;
      } else if (status != STATE_CRITICAL && (host->mos <= warn.mos)) {
        this_status = (this_status <= STATE_WARNING ? STATE_WARNING : this_status);
        status = STATE_WARNING;
        host->mos_status = STATE_WARNING;
      }
    }
    if (score_mode) {
      if (host->score <= crit.score) {
        this_status = STATE_CRITICAL;
        status = STATE_CRITICAL;
        host->score_status = STATE_CRITICAL;
      } else if (status != STATE_CRITICAL && (host->score <= warn.score)) {
        this_status = (this_status <= STATE_WARNING ? STATE_WARNING : this_status);
        status = STATE_WARNING;
        host->score_status = STATE_WARNING;
      }
    }

    if (this_status == STATE_WARNING) {
      hosts_warn++;
    }
    else if (this_status == STATE_OK) {
      hosts_ok++;
    }

    host = host->next;
  }

  /* this is inevitable */
  if (!targets_alive) {
    status = STATE_CRITICAL;
  }
  if (min_hosts_alive > -1) {
    if (hosts_ok >= min_hosts_alive) {
      status = STATE_OK;
    } else if ((hosts_ok + hosts_warn) >= min_hosts_alive) {
      status = STATE_WARNING;
    }
  }
  printf("%s - ", status_string[status]);

  host = list;
  while (host) {

    if (debug) {
      puts("");
    }
    if (i) {
      if (i < targets) {
        printf(" :: ");
      } else {
        printf("\n");
      }
    }
    i++;
    if (!host->icmp_recv) {
      status = STATE_CRITICAL;
      host->rtmin = 0;
      host->jitter_min = 0;
      if (host->flags & FLAG_LOST_CAUSE) {
        char address[address_length(address_family)];
        parse_address_string(address_family, &host->error_addr, address,
                             sizeof(address));
        printf("%s: %s @ %s. rta nan, lost %d%%", host->name,
               get_icmp_error_msg(host->icmp_type, host->icmp_code), address,
               100);
      } else {
        /* not marked as lost cause, so we have no flags for it */
        printf("%s: rta nan, lost 100%%", host->name);
      }
    } else {
      /* !icmp_recv */
      printf("%s", host->name);
      /* rta text output */
      if (rta_mode) {
        if (status == STATE_OK) {
          printf(" rta %0.3fms", host->rta / 1000);
        } else if (status == STATE_WARNING && host->rta_status == status) {
          printf(" rta %0.3fms >= %0.3fms", (float)host->rta / 1000,
                 (float)warn.rta / 1000);
        } else if (status == STATE_CRITICAL && host->rta_status == status) {
          printf(" rta %0.3fms >= %0.3fms", (float)host->rta / 1000,
                 (float)crit.rta / 1000);
        }
      }
      /* pl text output */
      if (pl_mode) {
        if (status == STATE_OK) {
          printf(" lost %u%%", host->pl);
        } else if (status == STATE_WARNING && host->pl_status == status) {
          printf(" lost %u%% >= %u%%", host->pl, warn.pl);
        } else if (status == STATE_CRITICAL && host->pl_status == status) {
          printf(" lost %u%% >= %u%%", host->pl, crit.pl);
        }
      }
      /* jitter text output */
      if (jitter_mode) {
        if (status == STATE_OK) {
          printf(" jitter %0.3fms", (float)host->jitter);
        } else if (status == STATE_WARNING && host->jitter_status == status) {
          printf(" jitter %0.3fms >= %0.3fms", (float)host->jitter, warn.jitter);
        } else if (status == STATE_CRITICAL && host->jitter_status == status) {
          printf(" jitter %0.3fms >= %0.3fms", (float)host->jitter, crit.jitter);
        }
      }
      /* mos text output */
      if (mos_mode) {
        if (status == STATE_OK) {
          printf(" MOS %0.1f", (float)host->mos);
        } else if (status == STATE_WARNING && host->mos_status == status) {
          printf(" MOS %0.1f <= %0.1f", (float)host->mos, (float)warn.mos);
        } else if (status == STATE_CRITICAL && host->mos_status == status) {
          printf(" MOS %0.1f <= %0.1f", (float)host->mos, (float)crit.mos);
        }
      }
      /* score text output */
      if (score_mode) {
        if (status == STATE_OK) {
          printf(" Score %u", (int)host->score);
        } else if (status == STATE_WARNING && host->score_status == status) {
          printf(" Score %u <= %u", (int)host->score, (int)warn.score);
        } else if (status == STATE_CRITICAL && host->score_status == status) {
          printf(" Score %u <= %u", (int)host->score, (int)crit.score);
        }
      }
      /* order statis text output */
      if (order_mode) {
        if (status == STATE_OK) {
          printf(" Packets in order");
        } else if (status == STATE_CRITICAL && host->order_status == status) {
          printf(" Packets out of order");
        }
      }
    }
    host = host->next;
  }

  /* iterate once more for pretty perfparse output */
  if (!(!rta_mode && !pl_mode && !jitter_mode && !score_mode && !mos_mode &&
        order_mode)) {
    printf("|");
  }
  i = 0;
  host = list;
  while (host) {
    if (debug) {
      puts("");
    }
    if (rta_mode) {
      printf("%srta=%0.3fms;%0.3f;%0.3f;0; ",
             (targets > 1) ? host->name : "", (float)host->rta / 1000,
             (float)warn.rta / 1000, (float)crit.rta / 1000);
    }
    if (pl_mode) {
      printf("%spl=%u%%;%u;%u;0;100 ", (targets > 1) ? host->name : "",
             host->pl, warn.pl, crit.pl);
    }
    if (rta_mode) {
      printf("%srtmax=%0.3fms;;;; %srtmin=%0.3fms;;;; ",
             (targets > 1) ? host->name : "", (float)host->rtmax / 1000,
             (targets > 1) ? host->name : "", (float)host->rtmin / 1000);
    }
    if (jitter_mode) {
      printf("%sjitter_avg=%0.3fms;%0.3f;%0.3f;0; %sjitter_max=%0.3fms;;;; "
             "%sjitter_min=%0.3fms;;;; ",
             (targets > 1) ? host->name : "", (float)host->jitter,
             (float)warn.jitter, (float)crit.jitter,
             (targets > 1) ? host->name : "", (float)host->jitter_max / 1000,
             (targets > 1) ? host->name : "", (float)host->jitter_min / 1000);
    }
    if (mos_mode) {
      printf("%smos=%0.1f;%0.1f;%0.1f;0;5 ", (targets > 1) ? host->name : "",
             (float)host->mos, (float)warn.mos, (float)crit.mos);
    }
    if (score_mode) {
      printf("%sscore=%u;%u;%u;0;100 ", (targets > 1) ? host->name : "",
             (int)host->score, (int)warn.score, (int)crit.score);
    }
    host = host->next;
  }

  if (min_hosts_alive > -1) {
    if (hosts_ok >= min_hosts_alive) {
      status = STATE_OK;
    } else if ((hosts_ok + hosts_warn) >= min_hosts_alive) {
      status = STATE_WARNING;
    }
  }

  /* finish with an empty line */
  puts("");
  if (debug) {
    printf("targets: %u, targets_alive: %u, hosts_ok: %u, hosts_warn: %u, "
           "min_hosts_alive: %i\n",
           targets, targets_alive, hosts_ok, hosts_warn, min_hosts_alive);
  }

  exit(status);
}

static u_int get_timevaldiff(struct timeval *early, struct timeval *later) {
  u_int ret;
  struct timeval now;

  if (!later) {
    gettimeofday(&now, &tz);
    later = &now;
  }
  if (!early)
    early = &prog_start;

  /* if early > later we return 0 so as to indicate a timeout */
  if (early->tv_sec > later->tv_sec ||
      (early->tv_sec == later->tv_sec && early->tv_usec > later->tv_usec)) {
    return 0;
  }

  ret = (later->tv_sec - early->tv_sec) * 1000000;
  ret += later->tv_usec - early->tv_usec;

  return ret;
}

static int add_target_ip(char *arg, struct sockaddr_storage *in) {
  struct rta_host *host;
  struct sockaddr_in *sin, *host_sin;
  struct sockaddr_in6 *sin6, *host_sin6;

  if (address_family == AF_INET) {
    sin = (struct sockaddr_in *)in;
  } else {
    sin6 = (struct sockaddr_in6 *)in;
  }

  /* disregard some addresses */
  if (((address_family == AF_INET && (sin->sin_addr.s_addr == INADDR_NONE ||
                                      sin->sin_addr.s_addr == INADDR_ANY))) ||
      (address_family == AF_INET6 &&
       sin6->sin6_addr.s6_addr == in6addr_any.s6_addr)) {
    return -1;
  }

  /* no point in adding two identical IP's, so don't. ;) */
  host = list;
  while (host) {
    host_sin = (struct sockaddr_in *)&host->saddr_in;
    host_sin6 = (struct sockaddr_in6 *)&host->saddr_in;
    if ((address_family == AF_INET &&
         host_sin->sin_addr.s_addr == sin->sin_addr.s_addr) ||
        (address_family == AF_INET6 &&
         host_sin6->sin6_addr.s6_addr == sin6->sin6_addr.s6_addr)) {
      if (debug) {
        printf("Identical IP already exists. Not adding %s\n", arg);
      }
      return -1;
    }
    host = host->next;
  }

  /* add the fresh ip */
  host = (struct rta_host *)malloc(sizeof(struct rta_host));
  if (!host) {
    char address[address_length(address_family)];
    parse_address_string(address_family, (struct sockaddr_storage *)&in,
                         address, sizeof(address));
    crash("add_target_ip(%s, %s): malloc(%d) failed", arg, address,
          sizeof(struct rta_host));
  }

  memset(host, 0, sizeof(struct rta_host));

  /* set the values. use calling name for output */
  host->name = strdup(arg);

  /* fill out the sockaddr_storage struct */
  if (address_family == AF_INET) {
    host_sin = (struct sockaddr_in *)&host->saddr_in;
    host_sin->sin_family = AF_INET;
    host_sin->sin_addr.s_addr = sin->sin_addr.s_addr;
  } else if (address_family == AF_INET6) {
    host_sin6 = (struct sockaddr_in6 *)&host->saddr_in;
    host_sin6->sin6_family = AF_INET6;
    memcpy(host_sin6->sin6_addr.s6_addr, sin6->sin6_addr.s6_addr,
           sizeof host_sin6->sin6_addr.s6_addr);
  }

  host->rtmin = DBL_MAX;
  host->rtmax = 0;
  host->jitter = 0;
  host->jitter_max = 0;
  host->jitter_min = DBL_MAX;
  host->last_tdiff = 0;
  host->order_status = STATE_OK;
  host->last_icmp_seq = 0;
  host->rta_status = 0;
  host->pl_status = 0;
  host->jitter_status = 0;
  host->mos_status = 0;
  host->score_status = 0;
  host->pl_status = 0;

  if (!list) {
    list = cursor = host;
  } else {
    cursor->next = host;
  }

  cursor = host;
  targets++;

  return 0;
}

/* wrapper for add_target_ip */
static int add_target(char *arg) {
  int error, result;
  struct sockaddr_storage ip;
  struct addrinfo hints, *res, *p;
  struct sockaddr_in *sin;
  struct sockaddr_in6 *sin6;

  switch (address_family) {
  case AF_INET:
    sin = (struct sockaddr_in *)&ip;
    result = inet_pton(address_family, arg, &sin->sin_addr);
    break;

  case AF_INET6:
    sin6 = (struct sockaddr_in6 *)&ip;
    result = inet_pton(address_family, arg, &sin6->sin6_addr);
    break;

  default:
    crash("Address family not supported");
  }

  /* don't resolve if we don't have to */
  if (result == 1) {
    /* don't add all ip's if we were given a specific one */
    return add_target_ip(arg, &ip);
  } else {
    errno = 0;
    memset(&hints, 0, sizeof(hints));
    hints.ai_family = address_family == AF_INET ? PF_INET : PF_INET6;
    hints.ai_socktype = SOCK_RAW;
    if ((error = getaddrinfo(arg, NULL, &hints, &res)) != 0) {
      errno = 0;
      crash("Failed to resolve %s: %s", arg, gai_strerror(error));
      return -1;
    }
  }

  /* possibly add all the IP's as targets */
  for (p = res; p != NULL; p = p->ai_next) {
    memcpy(&ip, p->ai_addr, p->ai_addrlen);
    add_target_ip(arg, &ip);

    /* this is silly, but it works */
    if (mode == MODE_HOSTCHECK || mode == MODE_ALL) {
      if (debug > 2) {
        printf("mode: %d\n", mode);
      }
      continue;
    }
    break;
  }
  freeaddrinfo(res);

  return 0;
}

static void set_source_ip(char *arg) {
  struct sockaddr_in src;

  memset(&src, 0, sizeof(src));
  src.sin_family = address_family;
  if ((src.sin_addr.s_addr = inet_addr(arg)) == INADDR_NONE) {
    src.sin_addr.s_addr = get_ip_address(arg);
  }
  if (bind(icmp_sock, (struct sockaddr *)&src, sizeof(src)) == -1) {
    crash("Cannot bind to IP address %s", arg);
  }
}

/* TODO: Move this to netutils.c and also change check_dhcp to use that. */
static in_addr_t get_ip_address(const char *ifname) {
#if defined(SIOCGIFADDR)
  struct ifreq ifr;
  struct sockaddr_in ip;

  strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name) - 1);
  ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = '\0';
  if (ioctl(icmp_sock, SIOCGIFADDR, &ifr) == -1) {
    crash("Cannot determine IP address of interface %s", ifname);
  }
  memcpy(&ip, &ifr.ifr_addr, sizeof(ip));
  return ip.sin_addr.s_addr;
#else
  errno = 0;
  crash("Cannot get interface IP address on this platform.");
#endif
}

/*
 * u = micro
 * m = milli
 * s = seconds
 * return value is in microseconds
 */
static u_int get_timevar(const char *str) {
  char p, u, *ptr;
  size_t len;
  u_int i, d;          /* integer and decimal, respectively */
  u_int factor = 1000; /* default to milliseconds */

  if (!str) {
    return 0;
  }
  len = strlen(str);
  if (!len) {
    return 0;
  }

  /* unit might be given as ms|m (millisec),
   * us|u (microsec) or just plain s, for seconds */
  p = '\0';
  u = str[len - 1];
  if (len >= 2 && !isdigit((int)str[len - 2])) {
    p = str[len - 2];
  }
  if (p && u == 's') {
    u = p;
  } else if (!p) {
    p = u;
  }
  if (debug > 2) {
    printf("evaluating %s, u: %c, p: %c\n", str, u, p);
  }

  if (u == 'u') {
    /* microseconds */
    factor = 1;
  } else if (u == 'm') {
    /* milliseconds */
    factor = 1000;
  } else if (u == 's') {
    /* seconds */
    factor = 1000000;
  }
  if (debug > 2) {
    printf("factor is %u\n", factor);
  }

  i = strtoul(str, &ptr, 0);
  if (!ptr || *ptr != '.' || strlen(ptr) < 2 || factor == 1) {
    return i * factor;
  }

  /* time specified in usecs can't have decimal points, so ignore them */
  if (factor == 1) {
    return i;
  }

  d = strtoul(ptr + 1, NULL, 0);

  /* d is decimal, so get rid of excess digits */
  while (d >= factor)
    d /= 10;

  /* the last parenthesis avoids floating point exceptions. */
  return ((i * factor) + (d * (factor / 10)));
}

/* not too good at checking errors, but it'll do (main() should barfe on -1) */
static int get_threshold(char *str, threshold *th) {
  char *p = NULL, i = 0;

  if (!str || !strlen(str) || !th) {
    return -1;
  }

  /* pointer magic slims code by 10 lines. i is bof-stop on stupid libc's */
  p = &str[strlen(str) - 1];
  while (p != &str[1]) {
    if (*p == '%') {
      *p = '\0';
    } else if (*p == ',' && i) {
      *p = '\0'; /* reset it so get_timevar(str) works nicely later */
      th->pl = (unsigned char)strtoul(p + 1, NULL, 0);
      break;
    }
    i = 1;
    p--;
  }
  th->rta = get_timevar(str);

  if (!th->rta) {
    return -1;
  }

  if (th->rta > MAXTTL * 1000000) {
    th->rta = MAXTTL * 1000000;
  }

  if (th->pl > 100) {
    th->pl = 100;
  }

  return 0;
}

/* not too good at checking errors, but it'll do (main() should barfe on -1) */
static int get_threshold2(char *str, threshold *warn, threshold *crit,
                          int type) {
  char *p = NULL, i = 0;

  if (!str || !strlen(str) || !warn || !crit) {
    return -1;
  }
  /* pointer magic slims code by 10 lines. i is bof-stop on stupid libc's */
  p = &str[strlen(str) - 1];
  while (p != &str[0]) {
    if ((*p == 'm') || (*p == '%')) {
      *p = '\0';
    } else if (*p == ',' && i) {
      *p = '\0'; /* reset it so get_timevar(str) works nicely later */
      if (type == 1) {
        crit->rta = atof(p + 1) * 1000;
      } else if (type == 2) {
        crit->pl = (unsigned char)strtoul(p + 1, NULL, 0);
      } else if (type == 3) {
        crit->jitter = atof(p + 1);
      } else if (type == 4) {
        crit->mos = atof(p + 1);
      } else if (type == 5) {
        crit->score = atof(p + 1);
      }
    }
    i = 1;
    p--;
  }
  if (type == 1) {
    warn->rta = atof(p) * 1000;
  } else if (type == 2) {
    warn->pl = (unsigned char)strtoul(p, NULL, 0);
  }
  if (type == 3) {
    warn->jitter = atof(p);
  } else if (type == 4) {
    warn->mos = atof(p);
  } else if (type == 5) {
    warn->score = atof(p);
  }
  return 0;
}

unsigned short icmp_checksum(unsigned short *p, int n) {
  unsigned short cksum;
  long sum = 0;

  while (n > 2) {
    sum += *p++;
    n -= sizeof(unsigned short);
  }

  /* mop up the occasional odd byte */
  if (n == 1) {
    sum += (unsigned char)*p;
  }

  sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
  sum += (sum >> 16);                 /* add carry */
  cksum = ~sum;                       /* ones-complement, trunc to 16 bits */

  return cksum;
}

void print_help(void) {
  print_revision(progname, NP_VERSION);
  printf(COPYRIGHT, copyright, email);

  print_usage();

  printf(UT_HELP_VRSN);
  printf(UT_EXTRA_OPTS);
  printf(" %s\n", "-w");
  printf("    %s", _("warning threshold (currently "));
  printf("%0.3fms,%u%%)\n", (float)warn.rta / 1000, warn.pl);
  printf(" %s\n", "-c");
  printf("    %s", _("critical threshold (currently "));
  printf("%0.3fms,%u%%)\n", (float)crit.rta / 1000, crit.pl);
  printf(" %s\n", "-R");
  printf("    %s\n", _("RTA, round trip average,  mode  warning,critical, ex. "
                       "100ms,200ms unit in ms"));
  printf(" %s\n", "-P");
  printf("    %s\n", _("packet loss mode, ex. 40%,50% , unit in %"));
  printf(" %s\n", "-J");
  printf(
      "    %s\n",
      _("jitter mode  warning,critical, ex. 40.000ms,50.000ms , unit in ms "));
  printf(" %s\n", "-M");
  printf("    %s\n",
         _("MOS mode, between 0 and 4.4  warning,critical, ex. 3.5,3.0"));
  printf(" %s\n", "-S");
  printf("    %s\n",
         _("score  mode, max value 100  warning,critical, ex. 80,70 "));
  printf(" %s\n", "-O");
  printf("    %s\n", _("detect out of order ICMP packts "));
  printf(" %s\n", "-4");
  printf("    %s\n", _("target address(es) are IPv4 and packets are ICMPv4"));
  printf(" %s\n", "-6");
  printf("    %s\n", _("target address(es) are IPv6 and packets are ICMPv6"));
  printf(" %s\n", "-H");
  printf("    %s\n", _("specify a target"));
  printf(" %s\n", "-s");
  printf("    %s\n", _("specify a source IP address or device name"));
  printf(" %s\n", "-n");
  printf("    %s", _("number of packets to send (currently "));
  printf("%u)\n", packets);
  printf(" %s\n", "-p");
  printf("    %s", _("number of packets to send (currently "));
  printf("%u)\n", packets);
  printf(" %s\n", "-i");
  printf("    %s", _("max packet interval (currently "));
  printf("%0.3fms)\n", (float)pkt_interval / 1000);
  printf(" %s\n", "-I");
  printf("    %s", _("max target interval (currently "));
  printf("%0.3fms)\n", (float)target_interval / 1000);
  printf(" %s\n", "-m");
  printf("    %s", _("number of alive hosts required for success"));
  printf("\n");
  printf(" %s\n", "-l");
  printf("    %s", _("TTL on outgoing packets (currently "));
  printf("%u)\n", ttl);
  printf(" %s\n", "-t");
  printf("    %s", _("timeout value (seconds, currently  "));
  printf("%u)\n", timeout);
  printf(" %s\n", "-b");
  printf("    %s\n", _("Number of icmp data bytes to send"));
  printf("    %s %u + %d)\n",
         _("Packet size will be data bytes + icmp header (currently"),
         icmp_data_size, ICMP_MINLEN);
  printf(" %s\n", "-v");
  printf("    %s\n", _("verbose"));
  printf("\n");
  printf("%s\n", _("Notes:"));
  printf(" %s\n", _("If not mode R,P,J,M,S or O is informed, default icmp "
                    "behavior, RTA and packet loss"));
  printf("\n");
  printf(" %s\n", _("The -H switch is optional. Naming a host (or several) to "
                    "check is not."));
  printf("\n");
  printf(" %s\n", _("When defining multiple addresses they must be provided as "
                    "the last argument."));
  printf("\n");
  printf(" %s\n", _("Threshold format for -w and -c is 200.25,60% for 200.25 "
                    "msec RTA and 60%"));
  printf(
      " %s\n",
      _("packet loss.  The default values should work well for most users."));
  printf(" %s\n", _("You can specify different RTA factors using the "
                    "standardized abbreviations"));
  printf(" %s\n", _("us (microseconds), ms (milliseconds, default) or just "
                    "plain s for seconds."));
  /* -d not yet implemented */
  /*  printf ("%s\n", _("Threshold format for -d is warn,crit.  12,14 means
    WARNING if >= 12 hops")); printf ("%s\n", _("are spent and CRITICAL if >= 14
    hops are spent.")); printf ("%s\n\n", _("NOTE: Some systems decrease TTL
    when forming ICMP_ECHOREPLY, others do not."));*/
  printf("\n");
  printf(" %s\n", _("The -v switch can be specified several times for "
                    "increased verbosity."));
  /*  printf ("%s\n", _("Long options are currently unsupported."));*/
  /*  printf ("%s\n", _("Options marked with * require an argument"));*/

  printf(UT_SUPPORT);
}

void print_usage(void) {
  printf("%s\n", _("Usage:"));
  printf(" %s [options] [-H] host1 host2 hostN\n", progname);
}