Code

src/oping.c: Define thresholds for coloring green and yellow in a central place.
[liboping.git] / src / oping.c
index 4946bf74dd6028d87abb03e1ec1bb14d4b3f9ab7..1590bfe54773c2ec8ec5d60ee85467a38ebe9ec3 100644 (file)
@@ -1,6 +1,6 @@
 /**
  * Object oriented C module to send ICMP and ICMPv6 `echo's.
- * Copyright (C) 2006-2010  Florian octo Forster <octo at verplant.org>
+ * Copyright (C) 2006-2014  Florian octo Forster <ff at octo.it>
  *
  * 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
@@ -25,6 +25,8 @@
 # include <stdlib.h>
 # include <stdio.h>
 # include <string.h>
+# include <stdint.h>
+# include <inttypes.h>
 # include <errno.h>
 # include <assert.h>
 #else
 # endif
 #endif
 
+#if HAVE_SYS_SOCKET_H
+# include <sys/socket.h>
+#endif
+#if HAVE_NETINET_IN_H
+# include <netinet/in.h>
+#endif
+#if HAVE_NETINET_IP_H
+# include <netinet/ip.h>
+#endif
+
 #if HAVE_NETDB_H
 # include <netdb.h> /* NI_MAXHOST */
 #endif
 #include <sys/types.h>
 #endif
 
+#include <locale.h>
+#include <langinfo.h>
+
 #if USE_NCURSES
-# include <ncurses.h>
+# define NCURSES_OPAQUE 1
+/* http://newsgroups.derkeiler.com/Archive/Rec/rec.games.roguelike.development/2010-09/msg00050.html */
+# define _X_OPEN_SOURCE_EXTENDED
+
+# if HAVE_NCURSESW_NCURSES_H
+#  include <ncursesw/ncurses.h>
+# elif HAVE_NCURSES_H
+#  include <ncurses.h>
+# endif
+
+# define OPING_GREEN 1
+# define OPING_YELLOW 2
+# define OPING_RED 3
+# define OPING_GREEN_HIST 4
+# define OPING_YELLOW_HIST 5
+# define OPING_RED_HIST 6
+
+double const threshold_green = 0.8;
+double const threshold_yellow = 0.95;
+
+static char const * const hist_symbols_utf8[] = {
+       "▁", "▂", "▃", "▄", "▅", "▆", "▇", "█" };
+static size_t const hist_symbols_utf8_num = sizeof (hist_symbols_utf8)
+       / sizeof (hist_symbols_utf8[0]);
+
+/* scancodes for 6 levels of horizontal bars, ncurses-specific */
+/* those are not the usual constants because those are not constant */
+static int const hist_symbols_acs[] = {
+       115, /* ACS_S9 "⎽" */
+       114, /* ACS_S7 "⎼" */
+       113, /* ACS_S5 "─" */
+       112, /* ACS_S3 "⎻" */
+       111  /* ACS_S1 "⎺" */
+};
+static size_t const hist_symbols_acs_num = sizeof (hist_symbols_acs)
+       / sizeof (hist_symbols_acs[0]);
+
+/* use different colors without a background for scancodes */
+static int const hist_colors_utf8[] = {
+       OPING_GREEN_HIST, OPING_YELLOW_HIST, OPING_RED_HIST };
+static int const hist_colors_acs[] = {
+       OPING_GREEN, OPING_YELLOW, OPING_RED };
+/* assuming that both arrays are the same size */
+static size_t const hist_colors_num = sizeof (hist_colors_utf8)
+       / sizeof (hist_colors_utf8[0]);
 #endif
 
+/* "─" */
+#define BOXPLOT_WHISKER_BAR       (113 | A_ALTCHARSET)
+/* "├" */
+#define BOXPLOT_WHISKER_LEFT_END  (116 | A_ALTCHARSET)
+/* "┤" */
+#define BOXPLOT_WHISKER_RIGHT_END (117 | A_ALTCHARSET)
+/* Inverted */
+#define BOXPLOT_BOX               ' '
+/* "│", inverted */
+#define BOXPLOT_MEDIAN            (120 | A_ALTCHARSET)
+
 #include "oping.h"
 
 #ifndef _POSIX_SAVED_IDS
 # define _POSIX_SAVED_IDS 0
 #endif
 
+#ifndef IPTOS_MINCOST
+# define IPTOS_MINCOST 0x02
+#endif
+
+/* Remove GNU specific __attribute__ settings when using another compiler */
+#if !__GNUC__
+# define __attribute__(x) /**/
+#endif
+
 typedef struct ping_context
 {
        char host[NI_MAXHOST];
        char addr[NI_MAXHOST];
 
+       int index;
        int req_sent;
        int req_rcvd;
 
@@ -85,6 +165,13 @@ typedef struct ping_context
        double latency_total;
        double latency_total_square;
 
+/* 1000 + one "infinity" bucket. */
+#define OPING_HISTOGRAM_BUCKETS 1001
+       uint32_t *histogram_counters;
+       uint32_t *histogram_accumulated;
+       double *histogram_ratio;
+       size_t latency_histogram_size;
+
 #if USE_NCURSES
        WINDOW *window;
 #endif
@@ -97,20 +184,30 @@ static char   *opt_device     = NULL;
 static char   *opt_filename   = NULL;
 static int     opt_count      = -1;
 static int     opt_send_ttl   = 64;
+static uint8_t opt_send_qos   = 0;
+#define OPING_DEFAULT_PERCENTILE 95.0
+static double  opt_percentile = -1.0;
+static double  opt_exit_status_threshold = 1.0;
+#if USE_NCURSES
+static int     opt_show_graph = 1;
+static int     opt_utf8       = 0;
+#endif
+
+static int host_num = 0;
 
 #if USE_NCURSES
 static WINDOW *main_win = NULL;
 #endif
 
-static void sigint_handler (int signal)
+static void sigint_handler (int signal) /* {{{ */
 {
        /* Make compiler happy */
        signal = 0;
        /* Exit the loop */
        opt_count = 0;
-}
+} /* }}} void sigint_handler */
 
-static ping_context_t *context_create (void)
+static ping_context_t *context_create (void) /* {{{ */
 {
        ping_context_t *ret;
 
@@ -124,14 +221,22 @@ static ping_context_t *context_create (void)
        ret->latency_total = 0.0;
        ret->latency_total_square = 0.0;
 
+       ret->latency_histogram_size = (size_t) OPING_HISTOGRAM_BUCKETS;
+       ret->histogram_counters = calloc (ret->latency_histogram_size,
+                       sizeof (*ret->histogram_counters));
+       ret->histogram_accumulated = calloc (ret->latency_histogram_size,
+                       sizeof (*ret->histogram_accumulated));
+       ret->histogram_ratio = calloc (ret->latency_histogram_size,
+                       sizeof (*ret->histogram_ratio));
+
 #if USE_NCURSES
        ret->window = NULL;
 #endif
 
        return (ret);
-}
+} /* }}} ping_context_t *context_create */
 
-static void context_destroy (ping_context_t *context)
+static void context_destroy (ping_context_t *context) /* {{{ */
 {
        if (context == NULL)
                return;
@@ -144,8 +249,17 @@ static void context_destroy (ping_context_t *context)
        }
 #endif
 
+       free (context->histogram_counters);
+       context->histogram_counters = NULL;
+
+       free (context->histogram_accumulated);
+       context->histogram_accumulated = NULL;
+
+       free (context->histogram_ratio);
+       context->histogram_ratio = NULL;
+
        free (context);
-}
+} /* }}} void context_destroy */
 
 static double context_get_average (ping_context_t *ctx) /* {{{ */
 {
@@ -161,6 +275,39 @@ static double context_get_average (ping_context_t *ctx) /* {{{ */
        return (ctx->latency_total / num_total);
 } /* }}} double context_get_average */
 
+static double context_get_percentile (ping_context_t *ctx, /* {{{ */
+               double percentile)
+{
+       double threshold = percentile / 100.0;
+       double index_to_ms_factor;
+       size_t i;
+       double ret;
+
+       if (ctx->histogram_ratio == NULL)
+               return (NAN);
+
+       for (i = 0; i < ctx->latency_histogram_size; i++)
+               if (ctx->histogram_ratio[i] >= threshold)
+                       break;
+
+       if (i >= ctx->latency_histogram_size)
+               return (NAN);
+       else if (i == (ctx->latency_histogram_size - 1))
+               return (INFINITY);
+
+       index_to_ms_factor = (1000.0 * opt_interval) / (ctx->latency_histogram_size - 1);
+
+       /* Multiply with i+1, because we're interested in the _upper_ bound of
+        * each bucket. */
+       ret = (index_to_ms_factor * ((double) (i + 1)));
+
+       /* Avoid reporting a higher latency than latency_max. */
+       if (ret > ctx->latency_max)
+               ret = ctx->latency_max;
+
+       return (ret);
+} /* }}} double context_get_percentile */
+
 static double context_get_stddev (ping_context_t *ctx) /* {{{ */
 {
        double num_total;
@@ -179,12 +326,53 @@ static double context_get_stddev (ping_context_t *ctx) /* {{{ */
                                / (num_total * (num_total - 1.0))));
 } /* }}} double context_get_stddev */
 
-static void usage_exit (const char *name, int status)
+static double context_get_packet_loss (const ping_context_t *ctx) /* {{{ */
 {
-       int name_length;
+       if (ctx == NULL)
+               return (-1.0);
+
+       if (ctx->req_sent < 1)
+               return (0.0);
+
+       return (100.0 * (ctx->req_sent - ctx->req_rcvd)
+                       / ((double) ctx->req_sent));
+} /* }}} double context_get_packet_loss */
+
+static int ping_initialize_contexts (pingobj_t *ping) /* {{{ */
+{
+       pingobj_iter_t *iter;
+       int index;
 
-       name_length = (int) strlen (name);
+       if (ping == NULL)
+               return (EINVAL);
 
+       index = 0;
+       for (iter = ping_iterator_get (ping);
+                       iter != NULL;
+                       iter = ping_iterator_next (iter))
+       {
+               ping_context_t *context;
+               size_t buffer_size;
+
+               context = context_create ();
+               context->index = index;
+
+               buffer_size = sizeof (context->host);
+               ping_iterator_get_info (iter, PING_INFO_HOSTNAME, context->host, &buffer_size);
+
+               buffer_size = sizeof (context->addr);
+               ping_iterator_get_info (iter, PING_INFO_ADDRESS, context->addr, &buffer_size);
+
+               ping_iterator_set_context (iter, (void *) context);
+
+               index++;
+       }
+
+       return (0);
+} /* }}} int ping_initialize_contexts */
+
+static void usage_exit (const char *name, int status) /* {{{ */
+{
        fprintf (stderr, "Usage: %s [OPTIONS] "
                                "-f filename | host [host [host ...]]\n"
 
@@ -193,24 +381,225 @@ static void usage_exit (const char *name, int status)
                        "  -c count     number of ICMP packets to send\n"
                        "  -i interval  interval with which to send ICMP packets\n"
                        "  -t ttl       time to live for each ICMP packet\n"
+                       "  -Q qos       Quality of Service (QoS) of outgoing packets\n"
+                       "               Use \"-Q help\" for a list of valid options.\n"
                        "  -I srcaddr   source address\n"
                        "  -D device    outgoing interface name\n"
                        "  -f filename  filename to read hosts from\n"
+#if USE_NCURSES
+                       "  -u / -U      force / disable UTF-8 output\n"
+                       "  -g graph     graph type to draw\n"
+#endif
+                       "  -P percent   Report the n'th percentile of latency\n"
+                       "  -Z percent   Exit with non-zero exit status if more than this percentage of\n"
+                       "               probes timed out. (default: never)\n"
 
                        "\noping "PACKAGE_VERSION", http://verplant.org/liboping/\n"
                        "by Florian octo Forster <octo@verplant.org>\n"
                        "for contributions see `AUTHORS'\n",
                        name);
        exit (status);
-}
+} /* }}} void usage_exit */
+
+__attribute__((noreturn))
+static void usage_qos_exit (const char *arg, int status) /* {{{ */
+{
+       if (arg != 0)
+               fprintf (stderr, "Invalid QoS argument: \"%s\"\n\n", arg);
+
+       fprintf (stderr, "Valid QoS arguments (option \"-Q\") are:\n"
+                       "\n"
+                       "  Differentiated Services (IPv4 and IPv6, RFC 2474)\n"
+                       "\n"
+                       "    be                     Best Effort (BE, default PHB).\n"
+                       "    ef                     Expedited Forwarding (EF) PHB group (RFC 3246).\n"
+                       "                           (low delay, low loss, low jitter)\n"
+                       "    va                     Voice Admit (VA) DSCP (RFC 5865).\n"
+                       "                           (capacity-admitted traffic)\n"
+                       "    af[1-4][1-3]           Assured Forwarding (AF) PHB group (RFC 2597).\n"
+                       "                           For example: \"af12\" (class 1, precedence 2)\n"
+                       "    cs[0-7]                Class Selector (CS) PHB group (RFC 2474).\n"
+                       "                           For example: \"cs1\" (priority traffic)\n"
+                       "\n"
+                       "  Type of Service (IPv4, RFC 1349, obsolete)\n"
+                       "\n"
+                       "    lowdelay     (%#04x)    minimize delay\n"
+                       "    throughput   (%#04x)    maximize throughput\n"
+                       "    reliability  (%#04x)    maximize reliability\n"
+                       "    mincost      (%#04x)    minimize monetary cost\n"
+                       "\n"
+                       "  Specify manually\n"
+                       "\n"
+                       "    0x00 - 0xff            Hexadecimal numeric specification.\n"
+                       "       0 -  255            Decimal numeric specification.\n"
+                       "\n",
+                       (unsigned int) IPTOS_LOWDELAY,
+                       (unsigned int) IPTOS_THROUGHPUT,
+                       (unsigned int) IPTOS_RELIABILITY,
+                       (unsigned int) IPTOS_MINCOST);
+
+       exit (status);
+} /* }}} void usage_qos_exit */
 
-static int read_options (int argc, char **argv)
+static int set_opt_send_qos (const char *opt) /* {{{ */
+{
+       if (opt == NULL)
+               return (EINVAL);
+
+       if (strcasecmp ("help", opt) == 0)
+               usage_qos_exit (/* arg = */ NULL, /* status = */ EXIT_SUCCESS);
+       /* DiffServ (RFC 2474): */
+       /* - Best effort (BE) */
+       else if (strcasecmp ("be", opt) == 0)
+               opt_send_qos = 0;
+       /* - Expedited Forwarding (EF, RFC 3246) */
+       else if (strcasecmp ("ef", opt) == 0)
+               opt_send_qos = 0xB8; /* == 0x2E << 2 */
+       /* - Voice Admit (VA, RFC 5865) */
+       else if (strcasecmp ("va", opt) == 0)
+               opt_send_qos = 0xB0; /* == 0x2D << 2 */
+       /* - Assured Forwarding (AF, RFC 2597) */
+       else if ((strncasecmp ("af", opt, strlen ("af")) == 0)
+                       && (strlen (opt) == 4))
+       {
+               uint8_t dscp;
+               uint8_t class = 0;
+               uint8_t prec = 0;
+
+               /* There are four classes, AF1x, AF2x, AF3x, and AF4x. */
+               if (opt[2] == '1')
+                       class = 1;
+               else if (opt[2] == '2')
+                       class = 2;
+               else if (opt[2] == '3')
+                       class = 3;
+               else if (opt[2] == '4')
+                       class = 4;
+               else
+                       usage_qos_exit (/* arg = */ opt, /* status = */ EXIT_SUCCESS);
+
+               /* In each class, there are three precedences, AFx1, AFx2, and AFx3 */
+               if (opt[3] == '1')
+                       prec = 1;
+               else if (opt[3] == '2')
+                       prec = 2;
+               else if (opt[3] == '3')
+                       prec = 3;
+               else
+                       usage_qos_exit (/* arg = */ opt, /* status = */ EXIT_SUCCESS);
+
+               dscp = (8 * class) + (2 * prec);
+               /* The lower two bits are used for Explicit Congestion Notification (ECN) */
+               opt_send_qos = dscp << 2;
+       }
+       /* - Class Selector (CS) */
+       else if ((strncasecmp ("cs", opt, strlen ("cs")) == 0)
+                       && (strlen (opt) == 3))
+       {
+               uint8_t class;
+
+               if ((opt[2] < '0') || (opt[2] > '7'))
+                       usage_qos_exit (/* arg = */ opt, /* status = */ EXIT_FAILURE);
+
+               /* Not exactly legal by the C standard, but I don't know of any
+                * system not supporting this hack. */
+               class = ((uint8_t) opt[2]) - ((uint8_t) '0');
+               opt_send_qos = class << 5;
+       }
+       /* Type of Service (RFC 1349) */
+       else if (strcasecmp ("lowdelay", opt) == 0)
+               opt_send_qos = IPTOS_LOWDELAY;
+       else if (strcasecmp ("throughput", opt) == 0)
+               opt_send_qos = IPTOS_THROUGHPUT;
+       else if (strcasecmp ("reliability", opt) == 0)
+               opt_send_qos = IPTOS_RELIABILITY;
+       else if (strcasecmp ("mincost", opt) == 0)
+               opt_send_qos = IPTOS_MINCOST;
+       /* Numeric value */
+       else
+       {
+               unsigned long value;
+               char *endptr;
+
+               errno = 0;
+               endptr = NULL;
+               value = strtoul (opt, &endptr, /* base = */ 0);
+               if ((errno != 0) || (endptr == opt)
+                               || (endptr == NULL) || (*endptr != 0)
+                               || (value > 0xff))
+                       usage_qos_exit (/* arg = */ opt, /* status = */ EXIT_FAILURE);
+               
+               opt_send_qos = (uint8_t) value;
+       }
+
+       return (0);
+} /* }}} int set_opt_send_qos */
+
+static char *format_qos (uint8_t qos, char *buffer, size_t buffer_size) /* {{{ */
+{
+       uint8_t dscp;
+       uint8_t ecn;
+       char *dscp_str;
+       char *ecn_str;
+
+       dscp = qos >> 2;
+       ecn = qos & 0x03;
+
+       switch (dscp)
+       {
+               case 0x00: dscp_str = "be";  break;
+               case 0x2e: dscp_str = "ef";  break;
+               case 0x2d: dscp_str = "va";  break;
+               case 0x0a: dscp_str = "af11"; break;
+               case 0x0c: dscp_str = "af12"; break;
+               case 0x0e: dscp_str = "af13"; break;
+               case 0x12: dscp_str = "af21"; break;
+               case 0x14: dscp_str = "af22"; break;
+               case 0x16: dscp_str = "af23"; break;
+               case 0x1a: dscp_str = "af31"; break;
+               case 0x1c: dscp_str = "af32"; break;
+               case 0x1e: dscp_str = "af33"; break;
+               case 0x22: dscp_str = "af41"; break;
+               case 0x24: dscp_str = "af42"; break;
+               case 0x26: dscp_str = "af43"; break;
+               case 0x08: dscp_str = "cs1";  break;
+               case 0x10: dscp_str = "cs2";  break;
+               case 0x18: dscp_str = "cs3";  break;
+               case 0x20: dscp_str = "cs4";  break;
+               case 0x28: dscp_str = "cs5";  break;
+               case 0x30: dscp_str = "cs6";  break;
+               case 0x38: dscp_str = "cs7";  break;
+               default:   dscp_str = NULL;
+       }
+
+       switch (ecn)
+       {
+               case 0x01: ecn_str = ",ecn(1)"; break;
+               case 0x02: ecn_str = ",ecn(0)"; break;
+               case 0x03: ecn_str = ",ce"; break;
+               default:   ecn_str = "";
+       }
+
+       if (dscp_str == NULL)
+               snprintf (buffer, buffer_size, "0x%02x%s", dscp, ecn_str);
+       else
+               snprintf (buffer, buffer_size, "%s%s", dscp_str, ecn_str);
+       buffer[buffer_size - 1] = 0;
+
+       return (buffer);
+} /* }}} char *format_qos */
+
+static int read_options (int argc, char **argv) /* {{{ */
 {
        int optchar;
 
        while (1)
        {
-               optchar = getopt (argc, argv, "46c:hi:I:t:f:D:");
+               optchar = getopt (argc, argv, "46c:hi:I:t:Q:f:D:Z:P:"
+#if USE_NCURSES
+                               "uUg:"
+#endif
+                               );
 
                if (optchar == -1)
                        break;
@@ -227,7 +616,12 @@ static int read_options (int argc, char **argv)
                                        int new_count;
                                        new_count = atoi (optarg);
                                        if (new_count > 0)
+                                       {
                                                opt_count = new_count;
+
+                                               if ((opt_percentile < 0.0) && (opt_count < 20))
+                                                       opt_percentile = 100.0 * (opt_count - 1) / opt_count;
+                                       }
                                        else
                                                fprintf(stderr, "Ignoring invalid count: %s\n",
                                                                optarg);
@@ -253,6 +647,7 @@ static int read_options (int argc, char **argv)
                                                opt_interval = new_interval;
                                }
                                break;
+
                        case 'I':
                                {
                                        if (opt_srcaddr != NULL)
@@ -277,111 +672,80 @@ static int read_options (int argc, char **argv)
                                break;
                        }
 
-                       case 'h':
-                               usage_exit (argv[0], 0);
+                       case 'Q':
+                               set_opt_send_qos (optarg);
                                break;
-                       default:
-                               usage_exit (argv[0], 1);
-               }
-       }
-
-       return (optind);
-}
-
-static void print_host (pingobj_iter_t *iter)
-{
-       double          latency;
-       unsigned int    sequence;
-       int             recv_ttl;
-       size_t          buffer_len;
-       size_t          data_len;
-       ping_context_t *context;
 
-       latency = -1.0;
-       buffer_len = sizeof (latency);
-       ping_iterator_get_info (iter, PING_INFO_LATENCY,
-                       &latency, &buffer_len);
-
-       sequence = 0;
-       buffer_len = sizeof (sequence);
-       ping_iterator_get_info (iter, PING_INFO_SEQUENCE,
-                       &sequence, &buffer_len);
+                       case 'P':
+                               {
+                                       double new_percentile;
+                                       new_percentile = atof (optarg);
+                                       if (isnan (new_percentile)
+                                                       || (new_percentile < 0.1)
+                                                       || (new_percentile > 100.0))
+                                               fprintf (stderr, "Ignoring invalid percentile: %s\n",
+                                                               optarg);
+                                       else
+                                               opt_percentile = new_percentile;
+                               }
+                               break;
 
-       recv_ttl = -1;
-       buffer_len = sizeof (recv_ttl);
-       ping_iterator_get_info (iter, PING_INFO_RECV_TTL,
-                       &recv_ttl, &buffer_len);
+#if USE_NCURSES
+                       case 'g':
+                               if (strcasecmp ("none", optarg) == 0)
+                                       opt_show_graph = 0;
+                               else if (strcasecmp ("prettyping", optarg) == 0)
+                                       opt_show_graph = 1;
+                               else if (strcasecmp ("boxplot", optarg) == 0)
+                                       opt_show_graph = 2;
+                               else if (strcasecmp ("histogram", optarg) == 0)
+                                       opt_show_graph = 3;
+                               else
+                                       fprintf (stderr, "Unknown graph option: %s\n", optarg);
+                               break;
 
-       data_len = 0;
-       ping_iterator_get_info (iter, PING_INFO_DATA,
-                       NULL, &data_len);
+                       case 'u':
+                               opt_utf8 = 2;
+                               break;
+                       case 'U':
+                               opt_utf8 = 1;
+                               break;
+#endif
 
-       context = (ping_context_t *) ping_iterator_get_context (iter);
+                       case 'Z':
+                       {
+                               char *endptr = NULL;
+                               double tmp;
 
-#if USE_NCURSES
-# define HOST_PRINTF(...) wprintw(main_win, __VA_ARGS__)
-#else
-# define HOST_PRINTF(...) printf(__VA_ARGS__)
-#endif
+                               errno = 0;
+                               tmp = strtod (optarg, &endptr);
+                               if ((errno != 0) || (endptr == NULL) || (*endptr != 0) || (tmp < 0.0) || (tmp > 100.0))
+                               {
+                                       fprintf (stderr, "Ignoring invalid -Z argument: %s\n", optarg);
+                                       fprintf (stderr, "The \"-Z\" option requires a numeric argument between 0 and 100.\n");
+                               }
+                               else
+                                       opt_exit_status_threshold = tmp / 100.0;
 
-       context->req_sent++;
-       if (latency > 0.0)
-       {
-               context->req_rcvd++;
-               context->latency_total += latency;
-               context->latency_total_square += (latency * latency);
+                               break;
+                       }
 
-               if ((context->latency_max < 0.0) || (context->latency_max < latency))
-                       context->latency_max = latency;
-               if ((context->latency_min < 0.0) || (context->latency_min > latency))
-                       context->latency_min = latency;
+                       case 'h':
+                               usage_exit (argv[0], 0);
+                               break;
 
-               HOST_PRINTF ("%zu bytes from %s (%s): icmp_seq=%u ttl=%i "
-                               "time=%.2f ms\n",
-                               data_len,
-                               context->host, context->addr,
-                               sequence, recv_ttl, latency);
-       }
-       else
-       {
-               HOST_PRINTF ("echo reply from %s (%s): icmp_seq=%u timeout\n",
-                               context->host, context->addr,
-                               sequence);
+                       default:
+                               usage_exit (argv[0], 1);
+               }
        }
 
-#if USE_NCURSES
-       wrefresh (main_win);
-       werase (context->window);
-       box (context->window, 0, 0);
-       mvwprintw (context->window, /* y = */ 0, /* x = */ 5,
-                       " %s ping statistics ",
-                       context->host);
-       mvwprintw (context->window, /* y = */ 1, /* x = */ 2,
-                       "%i packets transmitted, %i received, %.2f%% packet "
-                       "loss, time %.1fms",
-                       context->req_sent, context->req_rcvd,
-                       100.0 * (context->req_sent - context->req_rcvd) / ((double) context->req_sent),
-                       context->latency_total);
-       if (context->req_rcvd != 0)
-       {
-               double average;
-               double deviation;
+       if (opt_percentile <= 0.0)
+               opt_percentile = OPING_DEFAULT_PERCENTILE;
 
-               average = context_get_average (context);
-               deviation = context_get_stddev (context);
-                       
-               mvwprintw (context->window, /* y = */ 2, /* x = */ 2,
-                               "rtt min/avg/max/sdev = %.3f/%.3f/%.3f/%.3f ms",
-                               context->latency_min,
-                               average,
-                               context->latency_max,
-                               deviation);
-       }
-       wrefresh (context->window);
-#endif
-}
+       return (optind);
+} /* }}} read_options */
 
-static void time_normalize (struct timespec *ts)
+static void time_normalize (struct timespec *ts) /* {{{ */
 {
        while (ts->tv_nsec < 0)
        {
@@ -400,7 +764,7 @@ static void time_normalize (struct timespec *ts)
                ts->tv_sec  += 1;
                ts->tv_nsec -= 1000000000;
        }
-}
+} /* }}} void time_normalize */
 
 static void time_calc (struct timespec *ts_dest, /* {{{ */
                const struct timespec *ts_int,
@@ -428,66 +792,714 @@ static void time_calc (struct timespec *ts_dest, /* {{{ */
        time_normalize (ts_dest);
 } /* }}} void time_calc */
 
-static int print_header (pingobj_t *ping) /* {{{ */
+#if USE_NCURSES
+static _Bool has_utf8() /* {{{ */
+{
+# if HAVE_NCURSESW_NCURSES_H
+       if (!opt_utf8)
+       {
+               /* Automatically determine */
+               if (strcasecmp ("UTF-8", nl_langinfo (CODESET)) == 0)
+                       opt_utf8 = 2;
+               else
+                       opt_utf8 = 1;
+       }
+       return ((_Bool) (opt_utf8 - 1));
+# else
+       return (0);
+# endif
+} /* }}} _Bool has_utf8 */
+
+static int update_graph_boxplot (ping_context_t *ctx) /* {{{ */
+{
+       double *ratios;
+       size_t i;
+       size_t x_max;
+       size_t x;
+
+       x_max = (size_t) getmaxx (ctx->window);
+       if (x_max <= 8)
+               return (EINVAL);
+       x_max -= 4;
+
+       ratios = calloc (x_max, sizeof (*ratios));
+
+       /* Downsample */
+       for (i = 0; i < ctx->latency_histogram_size; i++)
+       {
+               x = i * x_max / ctx->latency_histogram_size;
+               ratios[x] = ctx->histogram_ratio[i];
+       }
+
+       for (x = 0; x < x_max; x++)
+       {
+               int symbol = ' ';
+               _Bool reverse = 0;
+
+               if (x == 0)
+               {
+                       if (ratios[x] >= 0.5)
+                       {
+                               symbol = BOXPLOT_MEDIAN;
+                               reverse = 1;
+                       }
+                       else if (ratios[x] > 0.25)
+                       {
+                               symbol = BOXPLOT_BOX;
+                               reverse = 1;
+                       }
+                       else if (ratios[x] > 0.025)
+                               symbol = BOXPLOT_WHISKER_BAR;
+                       else
+                               symbol = ' '; /* NOP */
+               }
+               else /* (x != 0) */
+               {
+                       if ((ratios[x - 1] < 0.5) && (ratios[x] >= 0.5))
+                       {
+                               symbol = BOXPLOT_MEDIAN;
+                               reverse = 1;
+                       }
+                       else if (((ratios[x] >= 0.25) && (ratios[x] <= 0.75))
+                                       || ((ratios[x - 1] < 0.75) && (ratios[x] > 0.75)))
+                       {
+                               symbol = BOXPLOT_BOX;
+                               reverse = 1;
+                       }
+                       else if ((ratios[x] < 0.5) && (ratios[x] >= 0.025))
+                       {
+                               if (ratios[x - 1] < 0.025)
+                                       symbol = BOXPLOT_WHISKER_LEFT_END;
+                               else
+                                       symbol = BOXPLOT_WHISKER_BAR;
+                       }
+                       else if ((ratios[x] > .5) && (ratios[x] < 0.975))
+                       {
+                               symbol = BOXPLOT_WHISKER_BAR;
+                       }
+                       else if ((ratios[x] >= 0.975) && (ratios[x - 1] < 0.975))
+                               symbol = BOXPLOT_WHISKER_RIGHT_END;
+               }
+
+               if (reverse)
+                       wattron (ctx->window, A_REVERSE);
+               mvwaddch (ctx->window, /* y = */ 3, /* x = */ (int) (x + 2), symbol);
+               // mvwprintw (ctx->window, /* y = */ 3, /* x = */ (int) (x + 2), symbol);
+               if (reverse)
+                       wattroff (ctx->window, A_REVERSE);
+       }
+
+       free (ratios);
+       return (0);
+} /* }}} int update_graph_boxplot */
+
+static int update_graph_prettyping (ping_context_t *ctx, /* {{{ */
+               double latency, unsigned int sequence)
+{
+       int color = OPING_RED;
+       char const *symbol = "!";
+       int symbolc = '!';
+
+       int x_max;
+       int x_pos;
+
+       x_max = getmaxx (ctx->window);
+       x_pos = ((sequence - 1) % (x_max - 4)) + 2;
+
+       if (latency >= 0.0)
+       {
+               double ratio;
+
+               size_t symbols_num = hist_symbols_acs_num;
+               size_t colors_num = 1;
+
+               size_t index_symbols;
+               size_t index_colors;
+               size_t intensity;
+
+               /* latency is in milliseconds, opt_interval is in seconds. */
+               ratio = (latency * 0.001) / opt_interval;
+               if (ratio > 1) {
+                       ratio = 1.0;
+               }
+
+               if (has_utf8 ())
+                       symbols_num = hist_symbols_utf8_num;
+
+               if (has_colors () == TRUE)
+                       colors_num = hist_colors_num;
+
+               intensity = (size_t) (ratio * ((double) (symbols_num * colors_num)));
+               if (intensity >= (symbols_num * colors_num))
+                       intensity = (symbols_num * colors_num) - 1;
+
+               index_symbols = intensity % symbols_num;
+               assert (index_symbols < symbols_num);
+
+               index_colors = intensity / symbols_num;
+               assert (index_colors < colors_num);
+
+               if (has_utf8())
+               {
+                       color = hist_colors_utf8[index_colors];
+                       symbol = hist_symbols_utf8[index_symbols];
+               }
+               else
+               {
+                       color = hist_colors_acs[index_colors];
+                       symbolc = hist_symbols_acs[index_symbols] | A_ALTCHARSET;
+               }
+       }
+       else /* if (!(latency >= 0.0)) */
+               wattron (ctx->window, A_BOLD);
+
+       if (has_colors () == TRUE)
+               wattron (ctx->window, COLOR_PAIR(color));
+
+       if (has_utf8())
+               mvwprintw (ctx->window, /* y = */ 3, /* x = */ x_pos, symbol);
+       else
+               mvwaddch (ctx->window, /* y = */ 3, /* x = */ x_pos, symbolc);
+
+       if (has_colors () == TRUE)
+               wattroff (ctx->window, COLOR_PAIR(color));
+
+       /* Use negation here to handle NaN correctly. */
+       if (!(latency >= 0.0))
+               wattroff (ctx->window, A_BOLD);
+
+       wprintw (ctx->window, " ");
+       return (0);
+} /* }}} int update_graph_prettyping */
+
+static int update_graph_histogram (ping_context_t *ctx) /* {{{ */
+{
+       uint32_t *counters;
+       uint32_t *accumulated;
+       uint32_t num;
+       uint32_t max;
+       size_t i;
+       size_t x_max;
+       size_t x;
+
+       size_t symbols_num = hist_symbols_acs_num;
+
+       if (has_utf8 ())
+               symbols_num = hist_symbols_utf8_num;
+
+       x_max = (size_t) getmaxx (ctx->window);
+       if (x_max <= 4)
+               return (EINVAL);
+       x_max -= 4;
+
+       counters = calloc (x_max, sizeof (*counters));
+       accumulated = calloc (x_max, sizeof (*accumulated));
+
+       /* Downsample */
+       max = 0;
+       for (i = 0; i < ctx->latency_histogram_size; i++)
+       {
+               x = i * x_max / ctx->latency_histogram_size;
+               counters[x] += ctx->histogram_counters[i];
+               accumulated[x] = counters[x];
+
+               if (max < counters[x])
+                       max = counters[x];
+       }
+
+       /* Sum */
+       for (x = 1; x < x_max; x++)
+               accumulated[x] += accumulated[x - 1];
+       num = accumulated[x_max - 1];
+
+       /* Calculate ratios */
+       for (x = 0; x < x_max; x++)
+       {
+               double height = ((double) counters[x]) / ((double) max);
+               double ratio_this = ((double) accumulated[x]) / ((double) num);
+               double ratio_prev = 0.0;
+               size_t index;
+               int color = 0;
+
+               index = (size_t) (height * ((double) symbols_num));
+               if (index >= symbols_num)
+                       index = symbols_num - 1;
+
+               if (x > 0)
+                       ratio_prev = ((double) accumulated[x - 1]) / ((double) num);
+
+               if (has_colors () == TRUE)
+               {
+                       if ((ratio_this <= threshold_green)
+                                       || ((ratio_prev < threshold_green)
+                                               && (ratio_this > threshold_green)))
+                               color = OPING_GREEN;
+                       else if ((ratio_this <= threshold_yellow)
+                                       || ((ratio_prev < threshold_yellow)
+                                               && (ratio_this > threshold_yellow)))
+                               color = OPING_YELLOW;
+                       else
+                               color = OPING_RED;
+
+                       wattron (ctx->window, COLOR_PAIR(color));
+               }
+
+               if (counters[x] == 0)
+                       mvwaddch (ctx->window, /* y = */ 3, /* x = */ x + 2, ' ');
+               else if (has_utf8 ())
+                       mvwprintw (ctx->window, /* y = */ 3, /* x = */ x + 2,
+                                       hist_symbols_utf8[index]);
+               else
+                       mvwaddch (ctx->window, /* y = */ 3, /* x = */ x + 2,
+                                       hist_symbols_acs[index] | A_ALTCHARSET);
+
+               if (has_colors () == TRUE)
+                       wattroff (ctx->window, COLOR_PAIR(color));
+
+       }
+
+       free (accumulated);
+       return (0);
+} /* }}} int update_graph_histogram */
+
+static int update_stats_from_context (ping_context_t *ctx, pingobj_iter_t *iter) /* {{{ */
+{
+       double latency = -1.0;
+       size_t buffer_len = sizeof (latency);
+
+       ping_iterator_get_info (iter, PING_INFO_LATENCY,
+                       &latency, &buffer_len);
+
+       unsigned int sequence = 0;
+       buffer_len = sizeof (sequence);
+       ping_iterator_get_info (iter, PING_INFO_SEQUENCE,
+                       &sequence, &buffer_len);
+
+
+       if ((ctx == NULL) || (ctx->window == NULL))
+               return (EINVAL);
+
+       /* werase (ctx->window); */
+
+       box (ctx->window, 0, 0);
+       wattron (ctx->window, A_BOLD);
+       mvwprintw (ctx->window, /* y = */ 0, /* x = */ 5,
+                       " %s ", ctx->host);
+       wattroff (ctx->window, A_BOLD);
+       wprintw (ctx->window, "ping statistics ");
+       mvwprintw (ctx->window, /* y = */ 1, /* x = */ 2,
+                       "%i packets transmitted, %i received, %.2f%% packet "
+                       "loss, time %.1fms",
+                       ctx->req_sent, ctx->req_rcvd,
+                       context_get_packet_loss (ctx),
+                       ctx->latency_total);
+       if (ctx->req_rcvd != 0)
+       {
+               double average;
+               double deviation;
+               double percentile;
+
+               average = context_get_average (ctx);
+               deviation = context_get_stddev (ctx);
+               percentile = context_get_percentile (ctx, opt_percentile);
+
+               mvwprintw (ctx->window, /* y = */ 2, /* x = */ 2,
+                               "rtt min/avg/%.0f%%/max/sdev = "
+                               "%.3f/%.3f/%.0f/%.3f/%.3f ms\n",
+                               opt_percentile,
+                               ctx->latency_min,
+                               average,
+                               percentile,
+                               ctx->latency_max,
+                               deviation);
+       }
+
+       if (opt_show_graph == 1)
+               update_graph_prettyping (ctx, latency, sequence);
+       else if (opt_show_graph == 2)
+               update_graph_boxplot (ctx);
+       else if (opt_show_graph == 3)
+               update_graph_histogram (ctx);
+
+       wrefresh (ctx->window);
+
+       return (0);
+} /* }}} int update_stats_from_context */
+
+static int on_resize (pingobj_t *ping) /* {{{ */
 {
        pingobj_iter_t *iter;
-       int i;
+       int width = 0;
+       int height = 0;
+       int main_win_height;
+       int box_height = (opt_show_graph == 0) ? 4 : 5;
+
+       getmaxyx (stdscr, height, width);
+       if ((height < 1) || (width < 1))
+               return (EINVAL);
+
+       main_win_height = height - (box_height * host_num);
+       wresize (main_win, main_win_height, /* width = */ width);
+       /* Allow scrolling */
+       scrollok (main_win, TRUE);
+       /* wsetscrreg (main_win, 0, main_win_height - 1); */
+       /* Allow hardware accelerated scrolling. */
+       idlok (main_win, TRUE);
+       wrefresh (main_win);
+
+       for (iter = ping_iterator_get (ping);
+                       iter != NULL;
+                       iter = ping_iterator_next (iter))
+       {
+               ping_context_t *context;
+
+               context = ping_iterator_get_context (iter);
+               if (context == NULL)
+                       continue;
+
+               if (context->window != NULL)
+               {
+                       delwin (context->window);
+                       context->window = NULL;
+               }
+               context->window = newwin (/* height = */ box_height,
+                               /* width = */ width,
+                               /* y = */ main_win_height + (box_height * context->index),
+                               /* x = */ 0);
+       }
+
+       return (0);
+} /* }}} */
+
+static int check_resize (pingobj_t *ping) /* {{{ */
+{
+       int need_resize = 0;
+
+       while (42)
+       {
+               int key = wgetch (stdscr);
+               if (key == ERR)
+                       break;
+               else if (key == KEY_RESIZE)
+                       need_resize = 1;
+       }
+
+       if (need_resize)
+               return (on_resize (ping));
+       else
+               return (0);
+} /* }}} int check_resize */
+
+static int pre_loop_hook (pingobj_t *ping) /* {{{ */
+{
+       pingobj_iter_t *iter;
+       int width = 0;
+       int height = 0;
+       int main_win_height;
+       int box_height = (opt_show_graph == 0) ? 4 : 5;
 
-#if USE_NCURSES
        initscr ();
        cbreak ();
        noecho ();
-#endif
+       nodelay (stdscr, TRUE);
+
+       getmaxyx (stdscr, height, width);
+       if ((height < 1) || (width < 1))
+               return (EINVAL);
+
+       if (has_colors () == TRUE)
+       {
+               start_color ();
+               init_pair (OPING_GREEN,  COLOR_GREEN,  /* default = */ 0);
+               init_pair (OPING_YELLOW, COLOR_YELLOW, /* default = */ 0);
+               init_pair (OPING_RED,    COLOR_RED,    /* default = */ 0);
+               init_pair (OPING_GREEN_HIST,  COLOR_GREEN,  COLOR_BLACK);
+               init_pair (OPING_YELLOW_HIST, COLOR_YELLOW, COLOR_GREEN);
+               init_pair (OPING_RED_HIST,    COLOR_RED,    COLOR_YELLOW);
+       }
+
+       main_win_height = height - (box_height * host_num);
+       main_win = newwin (/* height = */ main_win_height,
+                       /* width = */ width,
+                       /* y = */ 0, /* x = */ 0);
+       /* Allow scrolling */
+       scrollok (main_win, TRUE);
+       /* wsetscrreg (main_win, 0, main_win_height - 1); */
+       /* Allow hardware accelerated scrolling. */
+       idlok (main_win, TRUE);
+       wmove (main_win, /* y = */ main_win_height - 1, /* x = */ 0);
+       wrefresh (main_win);
 
-       i = 0;
        for (iter = ping_iterator_get (ping);
                        iter != NULL;
                        iter = ping_iterator_next (iter))
        {
                ping_context_t *context;
-               size_t buffer_size;
 
-               context = context_create ();
+               context = ping_iterator_get_context (iter);
+               if (context == NULL)
+                       continue;
 
-               buffer_size = sizeof (context->host);
-               ping_iterator_get_info (iter, PING_INFO_HOSTNAME, context->host, &buffer_size);
+               if (context->window != NULL)
+               {
+                       delwin (context->window);
+                       context->window = NULL;
+               }
+               context->window = newwin (/* height = */ box_height,
+                               /* width = */ width,
+                               /* y = */ main_win_height + (box_height * context->index),
+                               /* x = */ 0);
+       }
 
-               buffer_size = sizeof (context->addr);
-               ping_iterator_get_info (iter, PING_INFO_ADDRESS, context->addr, &buffer_size);
+
+       /* Don't know what good this does exactly, but without this code
+        * "check_resize" will be called right after startup and *somehow*
+        * this leads to display errors. If we purge all initial characters
+        * here, the problem goes away. "wgetch" is non-blocking due to
+        * "nodelay" (see above). */
+       while (wgetch (stdscr) != ERR)
+       {
+               /* eat up characters */;
+       }
+
+       return (0);
+} /* }}} int pre_loop_hook */
+
+static int pre_sleep_hook (pingobj_t *ping) /* {{{ */
+{
+       return (check_resize (ping));
+} /* }}} int pre_sleep_hook */
+
+static int post_sleep_hook (pingobj_t *ping) /* {{{ */
+{
+       return (check_resize (ping));
+} /* }}} int pre_sleep_hook */
+#else /* if !USE_NCURSES */
+static int pre_loop_hook (pingobj_t *ping) /* {{{ */
+{
+       pingobj_iter_t *iter;
+
+       for (iter = ping_iterator_get (ping);
+                       iter != NULL;
+                       iter = ping_iterator_next (iter))
+       {
+               ping_context_t *ctx;
+               size_t buffer_size;
+
+               ctx = ping_iterator_get_context (iter);
+               if (ctx == NULL)
+                       continue;
 
                buffer_size = 0;
                ping_iterator_get_info (iter, PING_INFO_DATA, NULL, &buffer_size);
 
-#if USE_NCURSES
-               context->window = newwin (/* height = */ 4, COLS,
-                               /* start y = */ 4*i, /* start x = */ 0);
-               box (context->window, 0, 0);
-               mvwprintw (context->window, /* y = */ 0, /* x = */ 5,
-                               " %s ping statistics ",
-                               context->host);
-               wrefresh (context->window);
-#else /* !USE_NCURSES */
                printf ("PING %s (%s) %zu bytes of data.\n",
-                               context->host, context->addr, buffer_size);
+                               ctx->host, ctx->addr, buffer_size);
+       }
+
+       return (0);
+} /* }}} int pre_loop_hook */
+
+static int pre_sleep_hook (__attribute__((unused)) pingobj_t *ping) /* {{{ */
+{
+       fflush (stdout);
+
+       return (0);
+} /* }}} int pre_sleep_hook */
+
+static int post_sleep_hook (__attribute__((unused)) pingobj_t *ping) /* {{{ */
+{
+       return (0);
+} /* }}} int post_sleep_hook */
 #endif
 
-               ping_iterator_set_context (iter, (void *) context);
+static size_t latency_to_bucket (ping_context_t *ctx, double latency) /* {{{ */
+{
+       size_t bucket;
+
+       /* latency is in ms, opt_interval is in s. */
+       bucket = (size_t) ((latency * (ctx->latency_histogram_size - 1))
+                       / (1000.0 * opt_interval));
+       if (bucket >= ctx->latency_histogram_size)
+               bucket = ctx->latency_histogram_size - 1;
 
-               i++;
+       return (bucket);
+} /* }}} size_t latency_to_bucket */
+
+static void update_context (ping_context_t *context, double latency) /* {{{ */
+{
+       size_t bucket;
+       size_t i;
+       double num;
+
+       context->req_rcvd++;
+       context->latency_total += latency;
+       context->latency_total_square += (latency * latency);
+
+       if ((context->latency_max < 0.0) || (context->latency_max < latency))
+               context->latency_max = latency;
+       if ((context->latency_min < 0.0) || (context->latency_min > latency))
+               context->latency_min = latency;
+
+       bucket = latency_to_bucket (context, latency);
+       num = (double) context->req_rcvd;
+
+       context->histogram_counters[bucket]++;
+
+       context->histogram_accumulated[0] = context->histogram_counters[0];
+       context->histogram_ratio[0] = ((double) context->histogram_accumulated[0]) / num;
+       for (i = 1; i < context->latency_histogram_size; i++)
+       {
+               context->histogram_accumulated[i] = context->histogram_accumulated[i - 1]
+                       + context->histogram_counters[i];
+               context->histogram_ratio[i] = ((double) context->histogram_accumulated[i]) / num;
        }
+} /* }}} void update_context */
+
+static void update_host_hook (pingobj_iter_t *iter, /* {{{ */
+               __attribute__((unused)) int index)
+{
+       double          latency;
+       unsigned int    sequence;
+       int             recv_ttl;
+       uint8_t         recv_qos;
+       char            recv_qos_str[16];
+       size_t          buffer_len;
+       size_t          data_len;
+       ping_context_t *context;
+
+       latency = -1.0;
+       buffer_len = sizeof (latency);
+       ping_iterator_get_info (iter, PING_INFO_LATENCY,
+                       &latency, &buffer_len);
+
+       sequence = 0;
+       buffer_len = sizeof (sequence);
+       ping_iterator_get_info (iter, PING_INFO_SEQUENCE,
+                       &sequence, &buffer_len);
+
+       recv_ttl = -1;
+       buffer_len = sizeof (recv_ttl);
+       ping_iterator_get_info (iter, PING_INFO_RECV_TTL,
+                       &recv_ttl, &buffer_len);
+
+       recv_qos = 0;
+       buffer_len = sizeof (recv_qos);
+       ping_iterator_get_info (iter, PING_INFO_RECV_QOS,
+                       &recv_qos, &buffer_len);
+
+       data_len = 0;
+       ping_iterator_get_info (iter, PING_INFO_DATA,
+                       NULL, &data_len);
+
+       context = (ping_context_t *) ping_iterator_get_context (iter);
 
 #if USE_NCURSES
-       delwin (main_win);
-       main_win = newwin (LINES - 4*i, COLS, 4*i, 0);
-       scrollok (main_win, TRUE);
+# define HOST_PRINTF(...) wprintw(main_win, __VA_ARGS__)
+#else
+# define HOST_PRINTF(...) printf(__VA_ARGS__)
 #endif
 
-       return (0);
-} /* }}} int print_header */
+       context->req_sent++;
+       if (latency > 0.0)
+       {
+               update_context (context, latency);
+
+#if USE_NCURSES
+               if (has_colors () == TRUE)
+               {
+                       size_t bucket;
+                       double ratio_this;
+                       double ratio_prev;
+                       int color = OPING_GREEN;
+
+                       bucket = latency_to_bucket (context, latency);
+                       ratio_this = context->histogram_ratio[bucket];
+                       if (bucket > 0)
+                               ratio_prev = context->histogram_ratio[bucket - 1];
+                       else
+                               ratio_prev = 0.0;
+
+                       if ((ratio_this <= threshold_green)
+                                       || ((ratio_prev < threshold_green)
+                                               && (ratio_this > threshold_green)))
+                               color = OPING_GREEN;
+                       else if ((ratio_this <= threshold_yellow)
+                                       || ((ratio_prev < threshold_yellow)
+                                               && (ratio_this > threshold_yellow)))
+                               color = OPING_YELLOW;
+                       else
+                               color = OPING_RED;
+
+                       HOST_PRINTF ("%zu bytes from %s (%s): icmp_seq=%u ttl=%i ",
+                                       data_len, context->host, context->addr,
+                                       sequence, recv_ttl,
+                                       format_qos (recv_qos, recv_qos_str, sizeof (recv_qos_str)));
+                       if ((recv_qos != 0) || (opt_send_qos != 0))
+                       {
+                               HOST_PRINTF ("qos=%s ",
+                                               format_qos (recv_qos, recv_qos_str, sizeof (recv_qos_str)));
+                       }
+                       HOST_PRINTF ("time=");
+                       wattron (main_win, COLOR_PAIR(color));
+                       HOST_PRINTF ("%.2f", latency);
+                       wattroff (main_win, COLOR_PAIR(color));
+                       HOST_PRINTF (" ms\n");
+               }
+               else
+               {
+#endif
+               HOST_PRINTF ("%zu bytes from %s (%s): icmp_seq=%u ttl=%i ",
+                               data_len,
+                               context->host, context->addr,
+                               sequence, recv_ttl);
+               if ((recv_qos != 0) || (opt_send_qos != 0))
+               {
+                       HOST_PRINTF ("qos=%s ",
+                                       format_qos (recv_qos, recv_qos_str, sizeof (recv_qos_str)));
+               }
+               HOST_PRINTF ("time=%.2f ms\n", latency);
+#if USE_NCURSES
+               }
+#endif
+       }
+       else
+       {
+#if USE_NCURSES
+               if (has_colors () == TRUE)
+               {
+                       HOST_PRINTF ("echo reply from %s (%s): icmp_seq=%u ",
+                                       context->host, context->addr,
+                                       sequence);
+                       wattron (main_win, COLOR_PAIR(OPING_RED) | A_BOLD);
+                       HOST_PRINTF ("timeout");
+                       wattroff (main_win, COLOR_PAIR(OPING_RED) | A_BOLD);
+                       HOST_PRINTF ("\n");
+               }
+               else
+               {
+#endif
+               HOST_PRINTF ("echo reply from %s (%s): icmp_seq=%u timeout\n",
+                               context->host, context->addr,
+                               sequence);
+#if USE_NCURSES
+               }
+#endif
+       }
 
-static int print_footer (pingobj_t *ping)
+#if USE_NCURSES
+       update_stats_from_context (context, iter);
+       wrefresh (main_win);
+#endif
+} /* }}} void update_host_hook */
+
+/* Prints statistics for each host, cleans up the contexts and returns the
+ * number of hosts which failed to return more than the fraction
+ * opt_exit_status_threshold of pings. */
+static int post_loop_hook (pingobj_t *ping) /* {{{ */
 {
        pingobj_iter_t *iter;
+       int failure_count = 0;
 
 #if USE_NCURSES
        endwin ();
@@ -504,20 +1516,32 @@ static int print_footer (pingobj_t *ping)
                printf ("\n--- %s ping statistics ---\n"
                                "%i packets transmitted, %i received, %.2f%% packet loss, time %.1fms\n",
                                context->host, context->req_sent, context->req_rcvd,
-                               100.0 * (context->req_sent - context->req_rcvd) / ((double) context->req_sent),
+                               context_get_packet_loss (context),
                                context->latency_total);
 
+               {
+                       double pct_failed = 1.0 - (((double) context->req_rcvd)
+                                       / ((double) context->req_sent));
+                       if (pct_failed > opt_exit_status_threshold)
+                               failure_count++;
+               }
+
                if (context->req_rcvd != 0)
                {
                        double average;
                        double deviation;
+                       double percentile;
 
                        average = context_get_average (context);
                        deviation = context_get_stddev (context);
+                       percentile = context_get_percentile (context, opt_percentile);
 
-                       printf ("rtt min/avg/max/sdev = %.3f/%.3f/%.3f/%.3f ms\n",
+                       printf ("rtt min/avg/%.0f%%/max/sdev = "
+                                       "%.3f/%.3f/%.0f/%.3f/%.3f ms\n",
+                                       opt_percentile,
                                        context->latency_min,
                                        average,
+                                       percentile,
                                        context->latency_max,
                                        deviation);
                }
@@ -526,8 +1550,8 @@ static int print_footer (pingobj_t *ping)
                context_destroy (context);
        }
 
-       return (0);
-} /* }}} int print_footer */
+       return (failure_count);
+} /* }}} int post_loop_hook */
 
 int main (int argc, char **argv) /* {{{ */
 {
@@ -560,6 +1584,7 @@ int main (int argc, char **argv) /* {{{ */
        }
 #endif
 
+        setlocale(LC_ALL, "");
        optind = read_options (argc, argv);
 
 #if !_POSIX_SAVED_IDS
@@ -593,6 +1618,12 @@ int main (int argc, char **argv) /* {{{ */
                                opt_send_ttl, ping_get_error (ping));
        }
 
+       if (ping_setopt (ping, PING_OPT_QOS, &opt_send_qos) != 0)
+       {
+               fprintf (stderr, "Setting TOS to %i failed: %s\n",
+                               opt_send_qos, ping_get_error (ping));
+       }
+
        {
                double temp_sec;
                double temp_nsec;
@@ -673,6 +1704,10 @@ int main (int argc, char **argv) /* {{{ */
                                fprintf (stderr, "Adding host `%s' failed: %s\n", host, errmsg);
                                continue;
                        }
+                       else
+                       {
+                               host_num++;
+                       }
                }
 
 #if _POSIX_SAVED_IDS
@@ -709,6 +1744,10 @@ int main (int argc, char **argv) /* {{{ */
                        fprintf (stderr, "Adding host `%s' failed: %s\n", argv[i], errmsg);
                        continue;
                }
+               else
+               {
+                       host_num++;
+               }
        }
 
        /* Permanently drop root privileges if we're setuid-root. */
@@ -724,7 +1763,7 @@ int main (int argc, char **argv) /* {{{ */
        saved_set_uid = (uid_t) -1;
 #endif
 
-       print_header (ping);
+       ping_initialize_contexts (ping);
 
        if (i == 0)
                return (1);
@@ -737,8 +1776,11 @@ int main (int argc, char **argv) /* {{{ */
                return (1);
        }
 
+       pre_loop_hook (ping);
+
        while (opt_count != 0)
        {
+               int index;
                int status;
 
                if (gettimeofday (&tv_begin, NULL) < 0)
@@ -747,20 +1789,28 @@ int main (int argc, char **argv) /* {{{ */
                        return (1);
                }
 
-               if (ping_send (ping) < 0)
+               status = ping_send (ping);
+               if (status == -EINTR)
+               {
+                       continue;
+               }
+               else if (status < 0)
                {
                        fprintf (stderr, "ping_send failed: %s\n",
                                        ping_get_error (ping));
                        return (1);
                }
 
+               index = 0;
                for (iter = ping_iterator_get (ping);
                                iter != NULL;
                                iter = ping_iterator_next (iter))
                {
-                       print_host (iter);
+                       update_host_hook (iter, index);
+                       index++;
                }
-               fflush (stdout);
+
+               pre_sleep_hook (ping);
 
                /* Don't sleep in the last iteration */
                if (opt_count == 1)
@@ -777,27 +1827,36 @@ int main (int argc, char **argv) /* {{{ */
                /* printf ("Sleeping for %i.%09li seconds\n", (int) ts_wait.tv_sec, ts_wait.tv_nsec); */
                while ((status = nanosleep (&ts_wait, &ts_wait)) != 0)
                {
-                       if (errno != EINTR)
+                       if (errno == EINTR)
                        {
-                               perror ("nanosleep");
-                               break;
+                               continue;
                        }
-                       else if (opt_count == 0)
+                       else
                        {
-                               /* sigint */
+                               perror ("nanosleep");
                                break;
                        }
                }
 
+               post_sleep_hook (ping);
+
                if (opt_count > 0)
                        opt_count--;
        } /* while (opt_count != 0) */
 
-       print_footer (ping);
+       /* Returns the number of failed hosts according to -Z. */
+       status = post_loop_hook (ping);
 
        ping_destroy (ping);
 
-       return (0);
+       if (status == 0)
+               exit (EXIT_SUCCESS);
+       else
+       {
+               if (status > 255)
+                       status = 255;
+               exit (status);
+       }
 } /* }}} int main */
 
 /* vim: set fdm=marker : */