/**
* This routine is used with etr_open to find an ET system's tcp host & port.
* Tries only twice to send broad/multicast packets. Waits 0.1 second for the
* first response and 1.1 second for the second.
*
* @param etname ET system file name
* @param ethost returns name of ET system's host
* @param port returns ET system's TCP port
* @param inetaddr returns host address as network-byte-ordered, 32-bit unsigned int
* @param config configuration passed to et_open
* @param allETinfo returns a pointer to single structure with all of the ET system's
* response information;
* may be null if all relevant info given in ethost, port, and inetaddr args
*
* @return ET_OK if successful
* @return ET_ERROR failure in select statement
* @return ET_ERROR_BADARG NULL arg for ethost, port, or inetaddr
* @return ET_ERROR_NOMEM cannot allocate memory
* @return ET_ERROR_NETWORK error find IP addresses or resolving host name;
* error converting dotted-decimal IP addr to binary;
* error create socket; failure reading socket
* @return ET_ERROR_SOCKET error setting socket option
* @return ET_ERROR_TOOMANY if multiple ET systems responded when policy is to return an error when
* more than one responds.
* @return ET_ERROR_TIMEOUT if no responses received in allotted time
*/
int et_findserver(const char *etname, char *ethost, int *port,
uint32_t *inetaddr, et_open_config *config, et_response **allETinfo)
{
struct timeval waittime;
/* wait 0.1 seconds before calling select the first time */
waittime.tv_sec = 0;
waittime.tv_usec = 100000;
return et_findserver2(etname, ethost, port, inetaddr, allETinfo, config, 2, &waittime);
}
/**
* This routine is used to quickly see if an ET system
* is alive by trying to get a response from its UDP
* broad/multicast thread. This is used only when the
* ET system is local.
*
* @param etname name of ET system to test
* @return 1 if a response was received, else 0
*/
int et_responds(const char *etname)
{
int port;
char ethost[ET_MAXHOSTNAMELEN];
uint32_t inetaddr;
et_openconfig openconfig; /* opaque structure */
et_open_config *config; /* real structure */
/* by default we'll broadcast to uname subnet */
et_open_config_init(&openconfig);
config = (et_open_config *) openconfig;
/* make sure we contact a LOCAL et system of this name! */
strcpy(config->host, ET_HOST_LOCAL);
/* send only 1 broadcast with a default maximum .01 sec wait */
if (et_findserver2(etname, ethost, &port, &inetaddr, NULL, config, 1, NULL) == ET_OK) {
/* got a response */
return 1;
}
/* no response */
return 0;
}
/**
* This routine determines whether we are looking for the ET system locally,
* locally on some non-pthread-mutex-sharing operating system, or remotely.
*
* @param filename name of ET system file.
* @param openconfig ET system open configuration.
*
* @returns @ref ET_REMOTE if looking for a remote ET system.
* @returns @ref ET_LOCAL if looking for a local ET system.
* @returns @ref ET_LOCAL_NOSHARE if looking for a local ET system without pthread mutex sharing.
*/
int et_findlocality(const char *filename, et_openconfig openconfig) {
char ethost[ET_IPADDRSTRLEN];
et_open_config *config = (et_open_config *) openconfig;
/* if local client opens ET system as remote (thru server) ...
* This option is for those applications (such as system
* monitoring) that only want to communication through
* an ET system's server and not map its shared mem.
*/
if (config->mode == ET_HOST_AS_REMOTE) {
return ET_REMOTE;
}
/* else if ET system host name is unknown and remote ... */
else if (strcmp(config->host, ET_HOST_REMOTE) == 0) {
return ET_REMOTE;
}
/* else if ET system is on local host */
else if ((strcmp(config->host, ET_HOST_LOCAL) == 0) ||
(strcmp(config->host, "localhost") == 0)) {
/* if local operating system can share pthread mutexes ... */
if (et_sharedmutex() == ET_MUTEX_SHARE) {
return ET_LOCAL;
}
else {
return ET_LOCAL_NOSHARE;
}
}
/* else if ET system host name is unknown and maybe anywhere ... */
else if (strcmp(config->host, ET_HOST_ANYWHERE) == 0) {
int err, port, isLocal;
uint32_t inetaddr;
struct timeval waittime;
waittime.tv_sec = 0;
waittime.tv_usec = 10000; /* 0.1 sec */
/* send only 1 broad/multicast with a 0.1 sec wait */
err = et_findserver2(filename, ethost, &port, &inetaddr, NULL, config, 1, &waittime, ET_DEBUG_NONE);
if ((err == ET_ERROR) || (err == ET_ERROR_TIMEOUT)) {
et_logmsg("ERROR", "et_findlocality, cannot find ET system\n");
return err;
}
else if (err == ET_ERROR_TOOMANY) {
/* many systems responded */
et_logmsg("ERROR", "et_findlocality, multiple ET systems responded\n");
return err;
}
etNetNodeIsLocal(ethost, &isLocal);
if (isLocal) {
if (et_sharedmutex() == ET_MUTEX_SHARE) {
return ET_LOCAL;
}
else {
return ET_LOCAL_NOSHARE;
}
}
return ET_REMOTE;
}
/* else ET system host name is given ... */
else {
int isLocal;
etNetNodeIsLocal(config->host, &isLocal);
if (isLocal) {
if (et_sharedmutex() == ET_MUTEX_SHARE) {
return ET_LOCAL;
}
else {
return ET_LOCAL_NOSHARE;
}
}
return ET_REMOTE;
}
return ET_REMOTE;
}
