#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <errno.h>
+#include <assert.h>
#include "iniparser/iniparser.h"
#define ICMP_ECHO_DATA_BYTES sizeof(struct timeval)
#define ICMP_ECHO_PACKET_BYTES ICMP_ECHO_HEADER_BYTES + ICMP_ECHO_DATA_BYTES
+/* Minimum time in seconds between pings. If this value is increased above the */
+/* `ping_interval` for a given host, some pings to that host may not be sent. */
+#define TIMER_RESOLUTION 1
+
/* Must be larger than the length of the longest configuration key (currently 'start_condition'). */
#define MAXCONFKEYLEN 20
/* Globals */
/* Since the program is based around signals, a linked list of hosts is maintained here. */
static struct monitor_host * hosts = NULL;
- static int send_delay = 1;
/* Set by command line flags. */
static bool verbose = false;
static bool retry_down_cmd = false;
}
/*
- * Subtracts two timeval structs.
- * Ensure out >= in.
- * Modifies out = out - in.
+ * Calculate difference between two timeval structs to within one second.
*/
-static void
-tv_sub(register struct timeval * out, register struct timeval * in)
+void
+timeval_diff(struct timeval * a, const struct timeval * b)
{
- if ((out->tv_usec -= in->tv_usec) < 0) {
- --out->tv_sec;
- out->tv_usec += 1000000;
- }
- out->tv_sec -= in->tv_sec;
+ assert(a->tv_sec >= b->tv_sec);
+ a->tv_sec -= b->tv_sec;
}
/*
struct timeval now;
gettimeofday(&now, (struct timezone *) NULL);
- tv_sub(&now, &p->last_ping_received);
+ timeval_diff(&now, &p->last_ping_received);
if (now.tv_sec > (p->max_delay + p->ping_interval)) {
if ((p->host_up) || retry_down_cmd) {
}
gettimeofday(&now, (struct timezone *) NULL);
- tv_sub(&now, &p->last_ping_sent);
+ timeval_diff(&now, &p->last_ping_sent);
if (now.tv_sec > p->ping_interval) { /* Time to send ping */
icp = (struct icmp *) outpack;
}
signal(SIGALRM, pinger); /* restore handler */
- alarm(send_delay);
+ alarm(TIMER_RESOLUTION);
}
static void
memcpy(&p->last_ping_received, &tv, sizeof(tv));
- tv_sub(&tv, (struct timeval *) &icmp->icmp_data[0]);
+ timeval_diff(&tv, (struct timeval *) &icmp->icmp_data[0]);
delay = tv.tv_sec * 1000 + (tv.tv_usec / 1000);
- if (verbose) printf("INFO: Got ICMP reply from %s in %d ms.\n", p->name, delay);
+ if (verbose) printf("INFO: Got ICMP reply from %s.\n", p->name);
if (!p->host_up) {
if (verbose) printf("INFO: Host %s started responding. Executing UP command.\n", p->name);
p->host_up = true;
fprintf(stderr, "WARN: Can't create socket. Skipping client %s.\n", p->name);
p->socket=-1;
} else {
- if (ok == 0) send_delay = p->ping_interval;
- else send_delay = gcd(send_delay, p->ping_interval);
+ //if (ok == 0) send_delay = p->ping_interval;
+ //else send_delay = gcd(send_delay, p->ping_interval);
ok++;
}
}
init_hosts();
signal(SIGALRM, pinger);
- alarm(send_delay);
+ alarm(TIMER_RESOLUTION);
get_response();