check_icmp plugin from A Ericsson

git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@975 f882894a-f735-0410-b71e-b25c423dba1c

plugins/check_icmp.c

@@ -0,0 +1,1381 @@
+/*
+ * check_icmp - A hack of fping2 to work with nagios.
+ *              This way we don't have to use the output parser.
+ *
+ * VIEWING NOTES:
+ * This file was formatted with tab indents at a tab stop of 4.
+ *
+ * It is highly recommended that your editor is set to this
+ * tab stop setting for viewing and editing.
+ *
+ * COPYLEFT;
+ * This programs copyright status is currently undetermined. Much of
+ * the code in it comes from the fping2 program which used to be licensed
+ * under the Stanford General Software License (available at
+ * http://graphics.stanford.edu/software/license.html). It is presently
+ * unclear what license (if any) applies to the original code at the
+ * moment.
+ *
+ * The fping website can be found at http://www.fping.com
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <time.h>
+#include <signal.h>
+
+#include <unistd.h>
+
+#include <stdlib.h>
+
+#include <string.h>
+#include <stddef.h>
+
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/socket.h>
+
+#include <sys/file.h>
+
+#include <netinet/in_systm.h>
+#include <netinet/in.h>
+
+/* Linux has bizarre ip.h and ip_icmp.h */
+/* Taken from the fping distro. Thank you. */
+#if defined( __linux__ )
+#include "linux.h"
+#else
+#include <netinet/ip.h>
+#include <netinet/ip_icmp.h>
+#endif /* defined(__linux__) */
+
+#include <arpa/inet.h>
+#include <netdb.h>
+
+/* RS6000 has sys/select.h */
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif							/* HAVE_SYS_SELECT_H */
+
+/* rta threshold values can't be larger than MAXTTL seconds */
+#ifndef MAXTTL
+#  define MAXTTL	255
+#endif
+#ifndef IPDEFTTL
+#  define IPDEFTTL	64
+#endif
+
+/*** externals ***/
+extern char *optarg;
+extern int optind, opterr;
+
+/*** Constants ***/
+#define REV_DATE	"2004-09-06"
+#define EMAIL		"ae@op5.se"
+#define VERSION		"0.8"
+
+#ifndef INADDR_NONE
+# define INADDR_NONE 0xffffffU
+#endif
+
+/*** Ping packet defines ***/
+/* data added after ICMP header for our nefarious purposes */
+typedef struct ping_data {
+	unsigned int ping_count;	/* counts up to -[n|p] count or 1 */
+	struct timeval ping_ts;		/* time sent */
+} PING_DATA;
+
+#define MIN_PING_DATA	sizeof(PING_DATA)
+#define	MAX_IP_PACKET	65536	/* (theoretical) max IP packet size */
+#define SIZE_IP_HDR		20
+#define SIZE_ICMP_HDR	ICMP_MINLEN	/* from ip_icmp.h */
+#define MAX_PING_DATA	(MAX_IP_PACKET - SIZE_IP_HDR - SIZE_ICMP_HDR)
+
+/*
+ *  Interval is the minimum amount of time between sending a ping packet to
+ *  any host.
+ *
+ *  Perhost_interval is the minimum amount of time between sending a ping
+ *  packet to a particular responding host
+ *
+ *  Timeout  is the initial amount of time between sending a ping packet to
+ *  a particular non-responding host.
+ *
+ *  Retry is the number of ping packets to send to a non-responding host
+ *  before giving up (in is-it-alive mode).
+ *
+ *  Backoff factor is how much longer to wait on successive retries.
+ */
+#ifndef DEFAULT_INTERVAL
+#define DEFAULT_INTERVAL 25		/* default time between packets (msec) */
+#endif
+
+#ifndef DEFAULT_RETRY
+#define DEFAULT_RETRY	1			/* number of times to retry a host */
+#endif
+
+#ifndef DEFAULT_TIMEOUT
+# define DEFAULT_TIMEOUT 1000
+#endif
+
+#ifndef DEFAULT_BACKOFF_FACTOR
+#define DEFAULT_BACKOFF_FACTOR 1.5	/* exponential timeout factor */
+#endif
+#define MIN_BACKOFF_FACTOR     1.0	/* exponential timeout factor */
+#define MAX_BACKOFF_FACTOR     5.0	/* exponential timeout factor */
+
+#ifndef DNS_TIMEOUT
+#define DNS_TIMEOUT 1000		/* time in usec for dns retry */
+#endif
+
+#ifndef MAX_RTA_THRESHOLD_VALUE
+# define MAX_RTA_THRESHOLD_VALUE 120*1000000 /* 2 minutes should be enough */
+#endif
+#ifndef MIN_RTA_THRESHOLD_VALUE
+# define MIN_RTA_THRESHOLD_VALUE 10000	/* minimum RTA threshold value */
+#endif
+
+/* sized so as to be like traditional ping */
+#define DEFAULT_PING_DATA_SIZE	(MIN_PING_DATA + 44)
+
+/* maxima and minima */
+#define MAX_COUNT				50		/* max count even if we're root */
+#define MAX_RETRY				5
+#define MIN_INTERVAL			25	/* msecs */
+#define MIN_TIMEOUT				50	/* msecs */
+
+/* response time array flags */
+#define RESP_WAITING	-1
+#define RESP_UNUSED		-2
+
+#define	ICMP_UNREACH_MAXTYPE	15
+
+/* entry used to keep track of each host we are pinging */
+struct host_entry {
+	int i;						/* index into array */
+	char *name;					/* name as given by user */
+	char *host;					/* text description of host */
+	struct sockaddr_in saddr;	/* internet address */
+	unsigned short **pr;		/* TCP port range to check for connectivity */
+	struct timeval last_send_time;	/* time of last packet sent */
+	unsigned int num_sent;		/* number of ping packets sent */
+	unsigned int num_recv;		/* number of pings received */
+	unsigned int total_time;	/* sum of response times */
+	unsigned int status;		/* this hosts status */
+	unsigned int running;		/* unset when through sending */
+	unsigned int waiting;		/* waiting for response */
+	int *resp_times;	/* individual response times */
+	struct host_entry *prev, *next;	/* doubly linked list */
+};
+
+typedef struct host_entry HOST_ENTRY;
+
+struct host_name_list {
+	char *entry;
+	struct host_name_list *next;
+};
+
+/* threshold structure */
+struct threshold {
+	unsigned int pl;	/* packet loss */
+	unsigned int rta;	/* roundtrip time average */
+};
+typedef struct threshold threshold;
+
+/*****************************************************************************
+ *                             Global Variables                              *
+ *****************************************************************************/
+
+HOST_ENTRY *rrlist = NULL;		/* linked list of hosts be pinged */
+HOST_ENTRY **table = NULL;		/* array of pointers to items in the list */
+HOST_ENTRY *cursor;
+
+char *prog;						/* our name */
+int ident;						/* our pid, for marking icmp packets */
+int sock;						/* socket */
+u_int debug = 0;
+
+/* threshold value defaults;
+ * WARNING;  60% packetloss or 200 msecs round trip average
+ * CRITICAL; 80% packetloss or 500 msecs round trip average */
+threshold warn = {60, 200 * 1000};
+threshold crit = {80, 500 * 1000};
+
+/* times get *100 because all times are calculated in 10 usec units, not ms */
+unsigned int retry = DEFAULT_RETRY;
+u_int timeout = DEFAULT_TIMEOUT * 100;
+u_int interval = DEFAULT_INTERVAL * 100;
+float backoff = DEFAULT_BACKOFF_FACTOR;
+u_int select_time;	/* calculated using maximum threshold rta value */
+u_int ping_data_size = DEFAULT_PING_DATA_SIZE;
+u_int ping_pkt_size;
+unsigned int count = 5;
+unsigned int trials = 1;
+
+/* global stats */
+int total_replies = 0;
+int num_jobs = 0;				/* number of hosts still to do */
+int num_hosts = 0;				/* total number of hosts */
+int num_alive = 0;				/* total number alive */
+int num_unreachable = 0;		/* total number unreachable */
+int num_noaddress = 0;			/* total number of addresses not found */
+int num_timeout = 0;			/* number of timed out packets */
+int num_pingsent = 0;			/* total pings sent */
+int num_pingreceived = 0;		/* total pings received */
+int num_othericmprcvd = 0;		/* total non-echo-reply ICMP received */
+
+struct timeval current_time;	/* current time (pseudo) */
+struct timeval start_time;
+struct timeval end_time;
+struct timeval last_send_time;	/* time last ping was sent */
+struct timezone tz;
+
+/* switches */
+int generate_flag = 0;			/* flag for IP list generation */
+int stats_flag, unreachable_flag, alive_flag;
+int elapsed_flag, version_flag, count_flag;
+int name_flag, addr_flag, backoff_flag;
+int multif_flag;
+
+/*** prototypes ***/
+void add_name(char *);
+void add_addr(char *, char *, struct in_addr);
+char *na_cat(char *, struct in_addr);
+char *cpystr(char *);
+void crash(char *);
+char *get_host_by_address(struct in_addr);
+int in_cksum(u_short *, int);
+void u_sleep(int);
+int recvfrom_wto(int, char *, int, struct sockaddr *, int);
+void remove_job(HOST_ENTRY *);
+void send_ping(int, HOST_ENTRY *);
+long timeval_diff(struct timeval *, struct timeval *);
+void usage(void);
+int wait_for_reply(int);
+void finish(void);
+int handle_random_icmp(struct icmp *, struct sockaddr_in *);
+char *sprint_tm(int);
+int get_threshold(char *, threshold *);
+
+/*** the various exit-states */
+enum {
+	STATE_OK = 0,
+	STATE_WARNING,
+	STATE_CRITICAL,
+	STATE_UNKNOWN,
+	STATE_DEPENDANT,
+	STATE_OOB
+};
+/* the strings that correspond to them */
+char *status_string[STATE_OOB] = {
+	"OK",
+	"WARNING",
+	"CRITICAL",
+	"UNKNOWN",
+	"DEPENDANT"
+};
+
+int status = STATE_OK;
+int fin_stat = STATE_OK;
+
+/*****************************************************************************
+ *                           Code block start                                *
+ *****************************************************************************/
+int main(int argc, char **argv)
+{
+	int c;
+	u_int lt, ht;
+	int advance;
+	struct protoent *proto;
+	uid_t uid;
+	struct host_name_list *host_ptr, *host_base_ptr;
+
+	if(strchr(argv[0], '/')) prog = strrchr(argv[0], '/') + 1;
+	else prog = argv[0];
+
+	/* check if we are root */
+	if(geteuid()) {
+		printf("Root access needed (for raw sockets)\n");
+		exit(STATE_UNKNOWN);
+	}
+
+	/* confirm that ICMP is available on this machine */
+	if((proto = getprotobyname("icmp")) == NULL)
+		crash("icmp: unknown protocol");
+
+	/* create raw socket for ICMP calls (ping) */
+	sock = socket(AF_INET, SOCK_RAW, proto->p_proto);
+
+	if(sock < 0)
+		crash("can't create raw socket");
+
+	/* drop privileges now that we have the socket */
+	if((uid = getuid())) {
+		seteuid(uid);
+	}
+	
+	if(argc < 2) usage();
+
+	ident = getpid() & 0xFFFF;
+
+	if(!(host_base_ptr = malloc(sizeof(struct host_name_list)))) {
+		crash("Unable to allocate memory for host name list\n");
+	}
+	host_ptr = host_base_ptr;
+
+	backoff_flag = 0;
+	opterr = 1;
+
+	/* get command line options
+	 * -H denotes a host (actually ignored and picked up later)
+	 * -h for help
+	 * -V or -v for version
+	 * -d to display hostnames rather than addresses
+	 * -t sets timeout for packets and tcp connects
+	 * -r defines retries (persistence)
+	 * -p or -n sets packet count (5)
+	 * -b sets packet size (56)
+	 * -w sets warning threshhold (200,40%)
+	 * -c sets critical threshhold (500,80%)
+	 * -i sets interval for both packet transmissions and connect attempts
+	 */
+#define OPT_STR "amH:hvVDdAp:n:b:r:t:i:w:c:"
+	while((c = getopt(argc, argv, OPT_STR)) != EOF) {
+		switch (c) {
+			case 'H':
+				if(!(host_ptr->entry = malloc(strlen(optarg) + 1))) {
+					crash("Failed to allocate memory for hostname");
+				}
+				memset(host_ptr->entry, 0, strlen(optarg) + 1);
+				host_ptr->entry = memcpy(host_ptr->entry, optarg, strlen(optarg));
+				if(!(host_ptr->next = malloc(sizeof(struct host_name_list))))
+					crash("Failed to allocate memory for hostname");
+				host_ptr = host_ptr->next;
+				host_ptr->next = NULL;
+//				add_name(optarg);
+				break;
+				/* this is recognized, but silently ignored.
+				 * host(s) are added later on */
+
+				break;
+			case 'w':
+				if(get_threshold(optarg, &warn)) {
+					printf("Illegal threshold pair specified for -%c", c);
+					usage();
+				}
+				break;
+
+			case 'c':
+				if(get_threshold(optarg, &crit)) {
+					printf("Illegal threshold pair specified for -%c", c);
+					usage();
+				}
+				break;
+
+			case 't':
+				if(!(timeout = (u_int) strtoul(optarg, NULL, 0) * 100)) {
+					printf("option -%c requires integer argument\n", c);
+					usage();
+				}
+				break;
+
+			case 'r':
+				if(!(retry = (u_int) strtoul(optarg, NULL, 0))) {
+					printf("option -%c requires integer argument\n", c);
+					usage();
+				}
+				break;
+
+			case 'i':
+				if(!(interval = (u_int) strtoul(optarg, NULL, 0) * 100)) {
+					printf("option -%c requires positive non-zero integer argument\n", c);
+					usage();
+				}
+				break;
+
+			case 'p':
+			case 'n':
+				if(!(count = (u_int) strtoul(optarg, NULL, 0))) {
+					printf("option -%c requires positive non-zero integer argument\n", c);
+					usage();
+				}
+				break;
+
+			case 'b':
+				if(!(ping_data_size = (u_int) strtoul(optarg, NULL, 0))) {
+					printf("option -%c requires integer argument\n", c);
+					usage();
+				}
+				break;
+
+			case 'h':
+				usage();
+				break;
+
+			case 'e':
+				elapsed_flag = 1;
+				break;
+				
+			case 'm':
+				multif_flag = 1;
+				break;
+				
+			case 'd':
+				name_flag = 1;
+				break;
+
+			case 'A':
+				addr_flag = 1;
+				break;
+				
+			case 's':
+				stats_flag = 1;
+				break;
+
+			case 'u':
+				unreachable_flag = 1;
+				break;
+
+			case 'a':
+				alive_flag = 1;
+				break;
+
+			case 'v':
+				printf("%s: Version %s $Date$\n", prog, VERSION, REV_DATE);
+				printf("%s: comments to %s\n", prog, EMAIL);
+				exit(STATE_OK);
+
+			case 'g':
+				/* use IP list generation */
+				/* mutex with file input or command line targets */
+				generate_flag = 1;
+				break;
+
+			default:
+				printf("option flag -%c specified, but not recognized\n", c);
+				usage();
+				break;
+		}
+	}
+
+	/* arguments are parsed, so now we validate them */
+
+	if(count > 1) count_flag = 1;
+
+	/* set threshold values to 10usec units (inherited from fping.c) */
+	crit.rta = crit.rta / 10;
+	warn.rta = warn.rta / 10;
+	select_time = crit.rta;
+	/* this isn't critical, but will most likely not be what the user expects
+	 * so we tell him/her about it, but keep running anyways */
+	if(warn.pl > crit.pl || warn.rta > crit.rta) {
+		select_time = warn.rta;
+		printf("(WARNING threshold > CRITICAL threshold) :: ");
+		fflush(stdout);
+	}
+
+	/* A timeout smaller than maximum rta threshold makes no sense */
+	if(timeout < crit.rta) timeout = crit.rta;
+	else if(timeout < warn.rta) timeout = warn.rta;
+
+	if((interval < MIN_INTERVAL * 100 || retry > MAX_RETRY) && getuid()) {
+		printf("%s: these options are too risky for mere mortals.\n", prog);
+		printf("%s: You need i >= %u and r < %u\n",
+				prog, MIN_INTERVAL, MAX_RETRY);
+		printf("Current settings; i = %d, r = %d\n",
+			   interval / 100, retry);
+		usage();
+	}
+
+	if((ping_data_size > MAX_PING_DATA) || (ping_data_size < MIN_PING_DATA)) {
+		printf("%s: data size %u not valid, must be between %u and %u\n",
+				prog, ping_data_size, MIN_PING_DATA, MAX_PING_DATA);
+		usage();
+
+	}
+
+	if((backoff > MAX_BACKOFF_FACTOR) || (backoff < MIN_BACKOFF_FACTOR)) {
+		printf("%s: backoff factor %.1f not valid, must be between %.1f and %.1f\n",
+				prog, backoff, MIN_BACKOFF_FACTOR, MAX_BACKOFF_FACTOR);
+		usage();
+
+	}
+
+	if(count > MAX_COUNT) {
+		printf("%s: count %u not valid, must be less than %u\n",
+				prog, count, MAX_COUNT);
+		usage();
+	}
+
+	if(count_flag) {
+		alive_flag = unreachable_flag = 0;
+	}
+
+	trials = (count > retry + 1) ? count : retry + 1;
+
+	/* handle host names supplied on command line or in a file */
+	/* if the generate_flag is on, then generate the IP list */
+	argv = &argv[optind];
+
+	/* cover allowable conditions */
+
+	/* generate requires command line parameters beyond the switches */
+	if(generate_flag && !*argv) {
+		printf("generate flag requires command line parameters beyond switches\n");
+		usage();
+	}
+
+	if(*argv && !generate_flag) {
+		while(*argv) {
+			if(!(host_ptr->entry = malloc(strlen(*argv) + 1))) {
+				crash("Failed to allocate memory for hostname");
+			}
+			memset(host_ptr->entry, 0, strlen(*argv) + 1);
+			host_ptr->entry = memcpy(host_ptr->entry, *argv, strlen(*argv));
+			if(!(host_ptr->next = malloc(sizeof(struct host_name_list))))
+				crash("Failed to allocate memory for hostname");
+			host_ptr = host_ptr->next;
+			host_ptr->next = NULL;
+
+//			add_name(*argv);
+			argv++;
+		}
+	}
+
+	// now add all the hosts
+	host_ptr = host_base_ptr;
+	while(host_ptr->next) {
+		add_name(host_ptr->entry);
+		host_ptr = host_ptr->next;
+	}
+
+	if(!num_hosts) {
+		printf("No hosts to work with!\n\n");
+		usage();
+	}
+
+	/* allocate array to hold outstanding ping requests */
+	table = (HOST_ENTRY **) malloc(sizeof(HOST_ENTRY *) * num_hosts);
+	if(!table) crash("Can't malloc array of hosts");
+
+	cursor = rrlist;
+
+	for(num_jobs = 0; num_jobs < num_hosts; num_jobs++) {
+		table[num_jobs] = cursor;
+		cursor->i = num_jobs;
+
+		cursor = cursor->next;
+	}							/* FOR */
+
+	ping_pkt_size = ping_data_size + SIZE_ICMP_HDR;
+
+	signal(SIGINT, (void *)finish);
+
+	gettimeofday(&start_time, &tz);
+	current_time = start_time;
+
+	last_send_time.tv_sec = current_time.tv_sec - 10000;
+
+	cursor = rrlist;
+	advance = 0;
+
+	/* main loop */
+	while(num_jobs) {
+		/* fetch all packets that receive within time boundaries */
+		while(num_pingsent &&
+			  cursor &&
+			  cursor->num_sent > cursor->num_recv &&
+			  wait_for_reply(sock)) ;
+
+		if(cursor && advance) {
+			cursor = cursor->next;
+		}
+
+		gettimeofday(&current_time, &tz);
+		lt = timeval_diff(&current_time, &last_send_time);
+		ht = timeval_diff(&current_time, &cursor->last_send_time);
+
+		advance = 1;
+
+		/* if it's OK to send while counting or looping or starting */
+		if(lt > interval) {
+			/* send if starting or looping */
+			if((cursor->num_sent == 0)) {
+				send_ping(sock, cursor);
+				continue;
+			}					/* IF */
+
+			/* send if counting and count not exceeded */
+			if(count_flag) {
+				if(cursor->num_sent < count) {
+					send_ping(sock, cursor);
+					continue;
+				}				/* IF */
+			}					/* IF */
+		}						/* IF */
+
+		/* is-it-alive mode, and timeout exceeded while waiting for a reply */
+		/*   and we haven't exceeded our retries                            */
+		if((lt > interval) && !count_flag && !cursor->num_recv &&
+		   (ht > timeout) && (cursor->waiting < retry + 1)) {
+			num_timeout++;
+
+			/* try again */
+			send_ping(sock, cursor);
+			continue;
+		}						/* IF */
+
+		/* didn't send, can we remove? */
+
+		/* remove if counting and count exceeded */
+		if(count_flag) {
+			if((cursor->num_sent >= count)) {
+				remove_job(cursor);
+				continue;
+			}					/* IF */
+		}						/* IF */
+		else {
+			/* normal mode, and we got one */
+			if(cursor->num_recv) {
+				remove_job(cursor);
+				continue;
+			}					/* IF */
+
+			/* normal mode, and timeout exceeded while waiting for a reply */
+			/* and we've run out of retries, so node is unreachable */
+			if((ht > timeout) && (cursor->waiting >= retry + 1)) {
+				num_timeout++;
+				remove_job(cursor);
+				continue;
+
+			}					/* IF */
+		}						/* ELSE */
+
+		/* could send to this host, so keep considering it */
+		if(ht > interval) {
+			advance = 0;
+		}
+	}							/* WHILE */
+
+	finish();
+	return 0;
+}								/* main() */
+
+/************************************************************
+ * Description:
+ *
+ * Main program clean up and exit point
+ ************************************************************/
+void finish()
+{
+	int i;
+	HOST_ENTRY *h;
+
+	gettimeofday(&end_time, &tz);
+
+	/* tot up unreachables */
+	for(i=0; i<num_hosts; i++) {
+		h = table[i];
+
+		if(!h->num_recv) {
+			num_unreachable++;
+			status = fin_stat = STATE_CRITICAL;
+			if(num_hosts == 1) {
+				printf("CRITICAL - %s is down (lost 100%%)|"
+					   "rta=;%d;%d;; pl=100%%;%d;%d;;\n",
+					   h->host,
+					   warn.rta / 100, crit.rta / 100,
+					   warn.pl, crit.pl);
+			}
+			else {
+				printf("%s is down (lost 100%%)", h->host);
+			}
+		}
+		else {
+			/* reset the status */
+			status = STATE_OK;
+
+			/* check for warning before critical, for debugging purposes */
+			if(warn.rta <= h->total_time / h->num_recv) {
+/*				printf("warn.rta exceeded\n");
+*/				status = STATE_WARNING;
+			}
+			if(warn.pl <= ((h->num_sent - h->num_recv) * 100) / h->num_sent) {
+/*				printf("warn.pl exceeded (pl=%d)\n",
+					   ((h->num_sent - h->num_recv) * 100) / h->num_sent);
+*/				status = STATE_WARNING;
+			}
+			if(crit.rta <= h->total_time / h->num_recv) {
+/*				printf("crit.rta exceeded\n");
+*/				status = STATE_CRITICAL;
+			}
+			if(crit.pl <= ((h->num_sent - h->num_recv) * 100) / h->num_sent) {
+/*				printf("crit.pl exceeded (pl=%d)\n",
+					   ((h->num_sent - h->num_recv) * 100) / h->num_sent);
+*/				status = STATE_CRITICAL;
+			}
+
+			if(num_hosts == 1 || status != STATE_OK) {
+				printf("%s - %s: rta %s ms, lost %d%%",
+					   status_string[status], h->host,
+					   sprint_tm(h->total_time / h->num_recv),
+					   h->num_sent > 0 ? ((h->num_sent - h->num_recv) * 100) / h->num_sent : 0
+					   );
+				/* perfdata only available for single-host stuff */
+				if(num_hosts == 1) {
+					printf("|rta=%sms;%d;%d;; pl=%d%%;%d;%d;;\n",
+						   sprint_tm(h->total_time / h->num_recv), warn.rta / 100, crit.rta / 100,
+						   h->num_sent > 0 ? ((h->num_sent - h->num_recv) * 100) / h->num_sent : 0, warn.pl, crit.pl
+						   );
+				}
+				else printf(" :: ");
+			}
+
+			/* fin_stat should always hold the WORST state */
+			if(fin_stat != STATE_CRITICAL && status != STATE_OK) {
+				fin_stat = status;
+			}
+		}
+	}
+
+	if(num_noaddress) {
+		printf("No hostaddress specified.\n");
+		usage();
+	}
+	else if(num_alive != num_hosts) {
+		/* for future multi-check support */
+		/*printf("num_alive != num_hosts (%d : %d)\n", num_alive, num_hosts);*/
+		fin_stat = STATE_CRITICAL;
+	}
+
+	if(num_hosts > 1) {
+		if(num_alive == num_hosts) {
+			printf("OK - All %d hosts are alive\n", num_hosts);
+		}
+		else {
+			printf("CRITICAL - %d of %d hosts are alive\n", num_alive, num_hosts);
+		}
+	}
+	exit(fin_stat);
+}
+
+
+void send_ping(int lsock, HOST_ENTRY *h)
+{
+	char *buffer;
+	struct icmp *icp;
+	PING_DATA *pdp;
+	int n;
+
+	buffer = (char *)malloc((size_t) ping_pkt_size);
+	if(!buffer)
+		crash("can't malloc ping packet");
+
+	memset(buffer, 0, ping_pkt_size * sizeof(char));
+	icp = (struct icmp *)buffer;
+
+	gettimeofday(&h->last_send_time, &tz);
+
+	icp->icmp_type = ICMP_ECHO;
+	icp->icmp_code = 0;
+	icp->icmp_cksum = 0;
+	icp->icmp_seq = h->i;
+	icp->icmp_id = ident;
+
+	pdp = (PING_DATA *) (buffer + SIZE_ICMP_HDR);
+	pdp->ping_ts = h->last_send_time;
+	pdp->ping_count = h->num_sent;
+
+	icp->icmp_cksum = in_cksum((u_short *) icp, ping_pkt_size);
+
+	n = sendto(lsock, buffer, ping_pkt_size, 0,
+			   (struct sockaddr *)&h->saddr, sizeof(struct sockaddr_in));
+
+	if(n < 0 || (unsigned int)n != ping_pkt_size) {
+		if(unreachable_flag) {
+			printf("%s error while sending ping: %s\n",
+				   h->host, strerror(errno));
+		}			/* IF */
+
+		num_unreachable++;
+		remove_job(h);
+	}				/* IF */
+	else {
+		/* mark this trial as outstanding */
+		h->resp_times[h->num_sent] = RESP_WAITING;
+
+		h->num_sent++;
+		h->waiting++;
+		num_pingsent++;
+		last_send_time = h->last_send_time;
+	}				/* ELSE */
+
+	free(buffer);
+}					/* send_ping() */
+
+int wait_for_reply(int lsock)
+{
+	int result;
+	static char buffer[4096];
+	struct sockaddr_in response_addr;
+	struct ip *ip;
+	int hlen;
+	struct icmp *icp;
+	int n;
+	HOST_ENTRY *h = NULL;
+	long this_reply;
+	int this_count;
+	struct timeval sent_time;
+
+	result = recvfrom_wto(lsock, buffer, sizeof(buffer),
+						  (struct sockaddr *)&response_addr, select_time);
+
+	if(result < 0) return 0;		/* timeout */
+
+	ip = (struct ip *)buffer;
+
+#if defined( __alpha__ ) && __STDC__ && !defined( __GLIBC__ )
+	/* The alpha headers are decidedly broken.
+	 * Using an ANSI compiler, it provides ip_vhl instead of ip_hl and
+	 * ip_v.  So, to get ip_hl, we mask off the bottom four bits.
+	 */
+	hlen = (ip->ip_vhl & 0x0F) << 2;
+#else
+	hlen = ip->ip_hl << 2;
+#endif /* defined(__alpha__) && __STDC__ */
+
+	if(result < hlen + ICMP_MINLEN) {
+		printf("received packet too short for ICMP (%d bytes from %s)\n", result,
+			   inet_ntoa(response_addr.sin_addr));
+
+		return (1);				/* too short */
+	}							/* IF */
+
+	icp = (struct icmp *)(buffer + hlen);
+	if(icp->icmp_type != ICMP_ECHOREPLY) {
+		/* handle some problem */
+		if(handle_random_icmp(icp, &response_addr))
+			num_othericmprcvd++;
+
+		return 1;
+	}							/* IF */
+
+	if(icp->icmp_id != ident)
+		return 1;				/* packet received, but not the one we are looking for! */
+
+	num_pingreceived++;
+
+	if(icp->icmp_seq >= (n_short) num_hosts)
+		return(1);				/* packet received, don't worry about it anymore */
+
+	n = icp->icmp_seq;
+	h = table[n];
+	
+	/* received ping is cool, so process it */
+
+	gettimeofday(&current_time, &tz);
+	h->waiting = 0;
+	h->num_recv++;
+
+	memcpy(&sent_time, icp->icmp_data + offsetof(PING_DATA, ping_ts),
+		   sizeof(sent_time));
+	memcpy(&this_count, icp->icmp_data, sizeof(this_count));
+
+	this_reply = timeval_diff(&current_time, &sent_time);
+	h->total_time += this_reply;
+	total_replies++;
+
+	/* note reply time in array, probably */
+	if((this_count >= 0) && ((unsigned int)this_count < trials)) {
+		if(h->resp_times[this_count] != RESP_WAITING) {
+			printf("%s : duplicate for [%d], %d bytes, %s ms",
+				   h->host, this_count, result, sprint_tm(this_reply));
+
+			if(response_addr.sin_addr.s_addr != h->saddr.sin_addr.s_addr)
+				printf(" [<- %s]\n", inet_ntoa(response_addr.sin_addr));
+		}					/* IF */
+		else h->resp_times[this_count] = this_reply;
+	}						/* IF */
+	else {
+		/* count is out of bounds?? */
+		printf("%s : duplicate for [%d], %d bytes, %s ms\n",
+			   h->host, this_count, result, sprint_tm(this_reply));
+		}						/* ELSE */
+	
+	if(h->num_recv == 1) {
+		num_alive++;
+	}							/* IF */
+
+	return num_jobs;
+}								/* wait_for_reply() */
+
+int handle_random_icmp(struct icmp *p, struct sockaddr_in *addr)
+{
+	struct icmp *sent_icmp;
+	u_char *c;
+	HOST_ENTRY *h;
+
+	c = (u_char *) p;
+	switch (p->icmp_type) {
+	case ICMP_UNREACH:
+		sent_icmp = (struct icmp *)(c + 28);
+
+		if((sent_icmp->icmp_type == ICMP_ECHO) &&
+		   (sent_icmp->icmp_id == ident) &&
+		   (sent_icmp->icmp_seq < (n_short) num_hosts)) {
+			/* this is a response to a ping we sent */
+			h = table[sent_icmp->icmp_seq];
+
+			if(p->icmp_code > ICMP_UNREACH_MAXTYPE) {
+				printf("ICMP Unreachable (Invalid Code) from %s for ICMP Echo sent to %s",
+						inet_ntoa(addr->sin_addr), h->host);
+
+			}					/* IF */
+			else {
+				printf("ICMP Unreachable from %s for ICMP Echo sent to %s",
+					   inet_ntoa(addr->sin_addr), h->host);
+
+			}					/* ELSE */
+
+			if(inet_addr(h->host) == INADDR_NONE)
+				printf(" (%s)", inet_ntoa(h->saddr.sin_addr));
+
+			printf("\n");
+
+		}						/* IF */
+
+		return 1;
+
+	case ICMP_SOURCEQUENCH:
+	case ICMP_REDIRECT:
+	case ICMP_TIMXCEED:
+	case ICMP_PARAMPROB:
+		sent_icmp = (struct icmp *)(c + 28);
+		if((sent_icmp->icmp_type = ICMP_ECHO) &&
+		   (sent_icmp->icmp_id = ident) &&
+		   (sent_icmp->icmp_seq < (n_short) num_hosts)) {
+			/* this is a response to a ping we sent */
+			h = table[sent_icmp->icmp_seq];
+			printf("ICMP Unreachable from %s for ICMP Echo sent to %s",
+					inet_ntoa(addr->sin_addr), h->host);
+
+			if(inet_addr(h->host) == INADDR_NONE)
+				printf(" (%s)", inet_ntoa(h->saddr.sin_addr));
+
+			printf("\n");
+		}						/* IF */
+
+		return 2;
+
+		/* no way to tell whether any of these are sent due to our ping */
+		/* or not (shouldn't be, of course), so just discard            */
+	case ICMP_TSTAMP:
+	case ICMP_TSTAMPREPLY:
+	case ICMP_IREQ:
+	case ICMP_IREQREPLY:
+	case ICMP_MASKREQ:
+	case ICMP_MASKREPLY:
+	default:
+		return 0;
+
+	}							/* SWITCH */
+
+}								/* handle_random_icmp() */
+
+int in_cksum(u_short * p, int n)
+{
+	register u_short answer;
+	register long sum = 0;
+	u_short odd_byte = 0;
+
+	while(n > 1) {
+		sum += *p++;
+		n -= 2;
+	}							/* WHILE */
+
+	/* mop up an odd byte, if necessary */
+	if(n == 1) {
+		*(u_char *) (&odd_byte) = *(u_char *) p;
+		sum += odd_byte;
+	}							/* IF */
+
+	sum = (sum >> 16) + (sum & 0xffff);	/* add hi 16 to low 16 */
+	sum += (sum >> 16);			/* add carry */
+	answer = ~sum;				/* ones-complement, truncate */
+
+	return (answer);
+
+}								/* in_cksum() */
+
+void add_name(char *name)
+{
+	struct hostent *host_ent;
+	int ipaddress;
+	struct in_addr *ipa = (struct in_addr *)&ipaddress;
+	struct in_addr *host_add;
+	char *nm;
+	int i = 0;
+	
+	if((ipaddress = inet_addr(name)) != -1) {
+		/* input name is an IP addr, go with it */
+		if(name_flag) {
+			if(addr_flag)
+				add_addr(name, na_cat(get_host_by_address(*ipa), *ipa), *ipa);
+			else {
+				nm = cpystr(get_host_by_address(*ipa));
+				add_addr(name, nm, *ipa);
+
+			}					/* ELSE */
+		}						/* IF */
+		else add_addr(name, name, *ipa);
+
+		return;
+	}							/* IF */
+
+	/* input name is not an IP addr, maybe it's a host name */
+	host_ent = gethostbyname(name);
+	if(host_ent == NULL) {
+		if(h_errno == TRY_AGAIN) {
+			u_sleep(DNS_TIMEOUT);
+			host_ent = gethostbyname(name);
+		}						/* IF */
+
+		if(host_ent == NULL) {
+			printf("%s address not found\n", name);
+			num_noaddress++;
+			return;
+		}						/* IF */
+	}							/* IF */
+
+	host_add = (struct in_addr *)*(host_ent->h_addr_list);
+	if(host_add == NULL) {
+		printf("%s has no address data\n", name);
+		num_noaddress++;
+		return;
+	}							/* IF */
+	else {
+		/* it is indeed a hostname with a real address */
+		while(host_add) {
+			if(name_flag && addr_flag)
+				add_addr(name, na_cat(name, *host_add), *host_add);
+			else if(addr_flag) {
+				nm = cpystr(inet_ntoa(*host_add));
+				add_addr(name, nm, *host_add);
+			}					/* ELSE IF */
+			else {
+				add_addr(name, name, *host_add);
+			}
+
+			if(!multif_flag) break;
+
+			host_add = (struct in_addr *)(host_ent->h_addr_list[++i]);
+		}						/* WHILE */
+	}							/* ELSE */
+}								/* add_name() */
+
+
+char *na_cat(char *name, struct in_addr ipaddr)
+{
+	char *nm, *as;
+
+	as = inet_ntoa(ipaddr);
+	nm = (char *)malloc(strlen(name) + strlen(as) + 4);
+
+	if(!nm)
+		crash("can't allocate some space for a string");
+
+	strcpy(nm, name);
+	strcat(nm, " (");
+	strcat(nm, as);
+	strcat(nm, ")");
+
+	return (nm);
+
+}								/* na_cat() */
+
+
+void add_addr(char *name, char *host, struct in_addr ipaddr)
+{
+	HOST_ENTRY *p;
+	unsigned int n;
+	int *i;
+
+	if(!(p = (HOST_ENTRY *) malloc(sizeof(HOST_ENTRY)))) {
+		crash("can't allocate HOST_ENTRY");
+	}
+
+	memset((char *)p, 0, sizeof(HOST_ENTRY));
+
+	p->name = name;
+	p->host = host;
+	p->saddr.sin_family = AF_INET;
+	p->saddr.sin_addr = ipaddr;
+	p->running = 1;
+
+	/* array for response time results */
+	if(!(i = (int *)malloc(trials * sizeof(int)))) {
+		crash("can't allocate resp_times array");
+	}
+
+	for(n = 1; n < trials; n++)
+		i[n] = RESP_UNUSED;
+
+		p->resp_times = i;
+
+	if(!rrlist) {
+		rrlist = p;
+		p->next = p;
+		p->prev = p;
+	}							/* IF */
+	else {
+		p->next = rrlist;
+		p->prev = rrlist->prev;
+		p->prev->next = p;
+		p->next->prev = p;
+	}							/* ELSE */
+
+	num_hosts++;
+}								/* add_addr() */
+
+
+void remove_job(HOST_ENTRY * h)
+{
+	h->running = 0;
+	h->waiting = 0;
+	num_jobs--;
+
+	
+	if(num_jobs) {
+		/* remove us from list of active jobs */
+		h->prev->next = h->next;
+		h->next->prev = h->prev;
+		if(h == cursor) cursor = h->next;
+	}							/* IF */
+	else {
+		cursor = NULL;
+		rrlist = NULL;
+	}							/* ELSE */
+
+}								/* remove_job() */
+
+
+char *get_host_by_address(struct in_addr in)
+{
+	struct hostent *h;
+	h = gethostbyaddr((char *)&in, sizeof(struct in_addr), AF_INET);
+
+	if(h == NULL || h->h_name == NULL)
+		return inet_ntoa(in);
+	else
+		return (char *)h->h_name;
+
+}								/* get_host_by_address() */
+
+
+char *cpystr(char *string)
+{
+	char *dst;
+
+	if(string) {
+		dst = (char *)malloc(1 + strlen(string));
+		if(!dst) crash("malloc() failed!");
+
+		strcpy(dst, string);
+		return dst;
+
+	}							/* IF */
+	else return NULL;
+
+}								/* cpystr() */
+
+
+void crash(char *msg)
+{
+	if(errno || h_errno) {
+		if(errno)
+			printf("%s: %s : %s\n", prog, msg, strerror(errno));
+		if(h_errno)
+			printf("%s: %s : A network error occurred\n", prog, msg);
+	}
+	else printf("%s: %s\n", prog, msg);
+
+	exit(STATE_UNKNOWN);
+}								/* crash() */
+
+
+long timeval_diff(struct timeval *a, struct timeval *b)
+{
+	double temp;
+
+	temp = (((a->tv_sec * 1000000) + a->tv_usec) -
+			((b->tv_sec * 1000000) + b->tv_usec)) / 10;
+
+	return (long)temp;
+
+}								/* timeval_diff() */
+
+
+char *sprint_tm(int t)
+{
+	static char buf[10];
+
+	/* <= 0.99 ms */
+	if(t < 100) {
+		sprintf(buf, "0.%02d", t);
+		return (buf);
+	}							/* IF */
+
+	/* 1.00 - 9.99 ms */
+	if(t < 1000) {
+		sprintf(buf, "%d.%02d", t / 100, t % 100);
+		return (buf);
+	}							/* IF */
+
+	/* 10.0 - 99.9 ms */
+	if(t < 10000) {
+		sprintf(buf, "%d.%d", t / 100, (t % 100) / 10);
+		return (buf);
+	}							/* IF */
+
+	/* >= 100 ms */
+	sprintf(buf, "%d", t / 100);
+	return (buf);
+}								/* sprint_tm() */
+
+
+/*
+ * select() is posix, so we expect it to be around
+ */
+void u_sleep(int u_sec)
+{
+	int nfound;
+	struct timeval to;
+	fd_set readset, writeset;
+	
+	to.tv_sec = u_sec / 1000000;
+	to.tv_usec = u_sec - (to.tv_sec * 1000000);
+/*	printf("u_sleep :: to.tv_sec: %d, to_tv_usec: %d\n",
+		   (int)to.tv_sec, (int)to.tv_usec);
+*/	
+	FD_ZERO(&writeset);
+	FD_ZERO(&readset);
+	nfound = select(0, &readset, &writeset, NULL, &to);
+	if(nfound < 0)
+		crash("select() in u_sleep:");
+
+	return;
+}								/* u_sleep() */
+
+
+/************************************************************
+ * Description:
+ *
+ * receive with timeout
+ * returns length of data read or -1 if timeout
+ * crash on any other errrors
+ ************************************************************/
+/* TODO: add MSG_DONTWAIT to recvfrom flags (currently 0) */
+int recvfrom_wto(int sock, char *buf, int len, struct sockaddr *saddr, int timo)
+{
+	int nfound = 0, slen, n;
+	struct timeval to;
+	fd_set readset, writeset;
+
+	to.tv_sec = timo / 1000000;
+	to.tv_usec = (timo - (to.tv_sec * 1000000)) * 10;
+
+/*	printf("to.tv_sec: %d, to.tv_usec: %d\n", (int)to.tv_sec, (int)to.tv_usec);
+*/
+
+	FD_ZERO(&readset);
+	FD_ZERO(&writeset);
+	FD_SET(sock, &readset);
+	nfound = select(sock + 1, &readset, &writeset, NULL, &to);
+	if(nfound < 0) crash("select() in recvfrom_wto");
+
+	if(nfound == 0) return -1;				/* timeout */
+
+	if(nfound) {
+		slen = sizeof(struct sockaddr);
+		n = recvfrom(sock, buf, len, 0, saddr, &slen);
+		if(n < 0) crash("recvfrom");
+		return(n);
+	}
+
+	return(0);	/* 0 bytes read, so return it */
+}								/* recvfrom_wto() */
+
+
+/*
+ * u = micro
+ * m = milli
+ * s = seconds
+ */
+int get_threshold(char *str, threshold *th)
+{
+	unsigned int i, factor = 0;
+	char *p = NULL;
+
+	if(!str || !strlen(str) || !th) return -1;
+
+	for(i=0; i<strlen(str); i++) {
+		/* we happily accept decimal points in round trip time thresholds,
+		 * but we ignore them quite blandly. The new way of specifying higher
+		 * precision is to specify 'u' (for microseconds),
+		 * 'm' (for millisecs - default) or 's' for seconds. */
+		if(!p && !factor) {
+			if(str[i] == 's') factor = 1000000;		/* seconds */
+			else if(str[i] == 'm') factor = 1000;	/* milliseconds */
+			else if(str[i] == 'u') factor = 1;		/* microseconds */
+		}
+
+		if(str[i] == '%') str[i] = '\0';
+		else if(str[i] == ',' && !p && i != (strlen(str) - 1)) {
+			p = &str[i+1];
+			str[i] = '\0';
+		}
+	}
+
+	/* default to milliseconds */
+	if(!factor) factor = 1000;
+
+	if(!p || !strlen(p)) return -1;
+	th->rta = (unsigned int)strtoul(str, NULL, 0) * factor;
+	th->pl = (unsigned int)strtoul(p, NULL, 0);
+	return 0;
+}
+
+/* make a blahblah */
+void usage(void)
+{
+	printf("\nUsage: %s [options] [targets]\n", prog);
+	printf("  -H host  target host\n");
+	printf("  -b n     ping packet size in bytes (default %d)\n", ping_data_size);
+	printf("  -n|p n   number of pings to send to each target (default %d)\n", count);
+	printf("  -r n     number of retries (default %d)\n", retry);
+	printf("  -t n     timeout value (in msec) (default %d)\n", timeout / 100);
+	printf("  -i n     packet interval (in msec) (default %d)\n", DEFAULT_INTERVAL);
+/* XXX - possibly on todo-list
+	printf("  -m       ping multiple interfaces on target host\n");
+	printf("  -a       show targets that are alive\n");
+	printf("  -d       show dead targets\n");
+*/	printf("  -v       show version\n");
+	printf("  -D       increase debug output level\n");
+	printf("  -w       warning threshold pair, given as RTA[ums],PL[%%]\n");
+	printf("  -c       critical threshold pair, given as RTA[ums],PL[%%]\n");
+	printf("\n");
+	printf("Note:\n");
+	printf("* This program requires root privileges to run properly.\n");
+	printf("  If it is run as setuid root it will halt with an error if;\n");
+	printf("    interval < 25 || retries > 5\n\n");
+	printf("* Threshold pairs are given as such;\n");
+	printf("    100,40%%\n");
+	printf("  to set a threshold value pair of 100 milliseconds and 40%% packetloss\n");
+	printf("  The '%%' sign is optional, and if rta value is suffixed by;\n");
+	printf("    s, rta time is set in seconds\n");
+	printf("    m, rta time will be set in milliseconds (this is default)\n");
+	printf("    u, rta time will be set in microseconds\n");
+	printf("  Decimal points are silently ignored for sideways compatibility.\n");
+	printf("\n");
+	exit(3);
+}								/* usage() */