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/*
* hbeat.c --
*
* Simple heartbeating.
*
*/
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <time.h>
#include <stdio.h>
#include "btime.h"
#include "hbeat.h"
struct hbeat_s {
char *host;
int max_timeout;
hbeat_state_t rhost_state;
unsigned int last_rhost_btime;
time_t start_quiet_time;
};
/*
* hbeat_init --
*
* Init a heartbeat to host, with max_timeout as supplied.
*
* Returns:
* A hbeat handle, or NULL on error;
*/
hbeat_t
hbeat_init(const char *host, int max_timeout)
{
struct hbeat_s *hbeatp;
hbeatp = malloc(sizeof *hbeatp);
if (!hbeatp) {
return NULL;
}
hbeatp->host = strdup(host);
hbeatp->max_timeout = max_timeout;
hbeatp->rhost_state = HOST_ALIVE;
hbeatp->last_rhost_btime = 0;
hbeatp->start_quiet_time = 0;
return hbeatp;
}
/*
* hbeat_free --
*
* Free a hbeat handle.
*/
void
hbeat_free(hbeat_t hbh)
{
struct hbeat_s *hbeatp = hbh;
free(hbeatp->host);
free(hbeatp);
}
/*
* hbeat --
*
* Attempt to contact host in the hbeat handle, run the hbeat
* "state machine" to decide if we the host is still "alive."
*
* Returns:
* 1 if host has been active or responded withing max_timeout secs.
* 0 if host is dead, no response for > max_timeout secs.
*/
unsigned int
hbeat(hbeat_t hbh)
{
struct hbeat_s *hbeatp = hbh;
unsigned int hbeat;
time_t current_time;
int retval;
/* User disabled heart beating */
if (!hbeatp->max_timeout) {
hbeatp->rhost_state = HOST_HBEAT_DISABLED;
return 1;
}
hbeat = btime(hbeatp->host);
current_time = time(NULL);
if (hbeat) { switch(hbeatp->rhost_state) {
/* Remote Host is Responding */
case HOST_REBOOT:
case HOST_TIMEOUT:
retval = 0;
break;
case HOST_QUIET:
hbeatp->rhost_state = HOST_ALIVE;
hbeatp->start_quiet_time = 0;
case HOST_ALIVE:
if (hbeatp->last_rhost_btime == 0) {
hbeatp->last_rhost_btime = hbeat;
retval = 1;
} else if (abs(hbeat - hbeatp->last_rhost_btime) > 5) {
fprintf(stderr, "Host rebooted (%d, %d)\n",
hbeat, hbeatp->last_rhost_btime);
hbeatp->rhost_state = HOST_REBOOT;
retval = 0;
} else {
hbeatp->last_rhost_btime = hbeat;
retval = 1;
}
break;
case HOST_HBEAT_DISABLED:
retval = 1;
break;
}} else { switch (hbeatp->rhost_state) {
/* Remote Host is NOT Responding */
case HOST_ALIVE:
hbeatp->rhost_state = HOST_QUIET;
hbeatp->start_quiet_time = time(NULL);
retval = 1;
break;
case HOST_QUIET:
if (current_time - hbeatp->start_quiet_time
> hbeatp->max_timeout) {
hbeatp->rhost_state = HOST_TIMEOUT;
retval = 0;
} else {
retval = 1;
}
break;
case HOST_TIMEOUT:
case HOST_REBOOT:
retval = 0;
break;
case HOST_HBEAT_DISABLED:
retval = 1;
break;
}}
return retval;
}
hbeat_state_t
hbeat_getstate(hbeat_t hbh)
{
return ((struct hbeat_s *)hbh)->rhost_state;
}
void
hbeat_setstate(hbeat_t hbh, hbeat_state_t state)
{
((struct hbeat_s *)hbh)->rhost_state = state;
return;
}
int
hbeat_getmaxtimeout(hbeat_t hbh)
{
return ((struct hbeat_s *)hbh)->max_timeout;
}
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