/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*
 * poold - dynamically adjust pool configuration according to load.
 */
#include <errno.h>
#include <jni.h>
#include <libintl.h>
#include <limits.h>
#include <link.h>
#include <locale.h>
#include <poll.h>
#include <pool.h>
#include <priv.h>
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>

#include <sys/stat.h>
#include <sys/types.h>
#include <sys/ucontext.h>
#include "utils.h"

#define	POOLD_DEF_CLASSPATH	"/usr/lib/pool/JPool.jar"
#define	POOLD_DEF_LIBPATH	"/usr/lib/pool"

#if defined(sparc)
#define	PLAT	"sparc"
#else
#if defined(i386)
#define	PLAT	"i386"
#else
#error Unrecognized platform.
#endif
#endif

#define	PID_PROPERTY_NAME	"system.poold.pid"

#define	CLASS_FIELD_DESC(class_desc)	"L" class_desc ";"

#define	LEVEL_CLASS_DESC	"java/util/logging/Level"
#define	POOLD_CLASS_DESC	"com/sun/solaris/domain/pools/Poold"
#define	SEVERITY_CLASS_DESC	"com/sun/solaris/service/logging/Severity"
#define	STRING_CLASS_DESC	"java/lang/String"
#define	SYSTEM_CLASS_DESC	"java/lang/System"
#define	LOGGER_CLASS_DESC	"java/util/logging/Logger"

extern char *optarg;

static const char *pname;

static enum {
	LD_TERMINAL = 1,
	LD_SYSLOG,
	LD_JAVA
} log_dest = LD_SYSLOG;

typedef enum {
	PGAS_GET_ONLY = 1,
	PGAS_GET_AND_SET
} pgas_mode_t;

static const char PNAME_FMT[] = "%s: ";
static const char ERRNO_FMT[] = ": %s";

static JavaVM *jvm;
static int lflag;

static jmethodID log_mid;
static jobject severity_err;
static jobject severity_notice;
static jobject base_log;
static jclass poold_class;
static jobject poold_instance;
static int instance_running;
static pthread_mutex_t instance_running_lock = PTHREAD_MUTEX_INITIALIZER;

static sigset_t hdl_set;

static void pu_die(const char *fmt, ...) __NORETURN;

static void
usage(void)
{
	(void) fprintf(stderr, gettext("Usage:\t%s [-l <level>]\n"), pname);

	exit(E_USAGE);
}

static void
pu_output(int severity, const char *fmt, va_list alist)
{
	int err = errno;
	char line[255] = "";
	jobject jseverity;
	jobject jline;
	JNIEnv *env;
	int detach_required = 0;
	if (pname != NULL && log_dest == LD_TERMINAL)
		(void) snprintf(line, sizeof (line), gettext(PNAME_FMT), pname);

	(void) vsnprintf(line + strlen(line), sizeof (line) - strlen(line),
	    fmt, alist);

	if (line[strlen(line) - 1] != '\n')
		(void) snprintf(line + strlen(line), sizeof (line) -
		    strlen(line), gettext(ERRNO_FMT), strerror(err));
	else
		line[strlen(line) - 1] = 0;

	switch (log_dest) {
	case LD_TERMINAL:
		(void) fprintf(stderr, "%s\n", line);
		(void) fflush(stderr);
		break;
	case LD_SYSLOG:
		syslog(LOG_ERR, "%s", line);
		break;
	case LD_JAVA:
		if (severity == LOG_ERR)
			jseverity = severity_err;
		else
			jseverity = severity_notice;

		if (jvm) {
			(*jvm)->GetEnv(jvm, (void **)&env, JNI_VERSION_1_2);
			if (env == NULL) {
				detach_required = 1;
				(*jvm)->AttachCurrentThread(jvm,
				    (void **)&env, NULL);
			}
			if ((jline = (*env)->NewStringUTF(env, line)) != NULL)
				(*env)->CallVoidMethod(env, base_log, log_mid,
				    jseverity, jline);
			if (detach_required)
				(*jvm)->DetachCurrentThread(jvm);
		}
	}
}

/*PRINTFLIKE1*/
static void
pu_notice(const char *fmt, ...)
{
	va_list alist;
	va_start(alist, fmt);
	pu_output(LOG_NOTICE, fmt, alist);
	va_end(alist);
}

/*PRINTFLIKE1*/
static void
pu_die(const char *fmt, ...)
{
	va_list alist;
	va_start(alist, fmt);
	pu_output(LOG_ERR, fmt, alist);
	va_end(alist);
	exit(E_ERROR);
}

/*
 * Update the "system.poold.pid" to reflect this instance of poold only
 * if the property hasn't been set already to reflect an existing
 * process, and mode is not set to PGAS_GET_ONLY.  Returns the
 * property's pre-existing value, or -1 otherwise.
 */
static pid_t
poold_get_and_set_pid(pgas_mode_t mode)
{
	pool_conf_t *conf;
	pool_elem_t *pe;
	pool_value_t *val;
	int64_t ival;

	if (!(conf = pool_conf_alloc()))
		return ((pid_t)-1);

	if (pool_conf_open(conf, pool_dynamic_location(), PO_RDWR) != 0) {
		(void) pool_conf_free(conf);
		return ((pid_t)-1);
	}

	pe = pool_conf_to_elem(conf);
	if (!(val = pool_value_alloc())) {
		(void) pool_conf_close(conf);
		return ((pid_t)-1);
	}

	if (pool_get_property(conf, pe, PID_PROPERTY_NAME, val) == POC_INT) {
		if (pool_value_get_int64(val, &ival) != 0) {
			(void) pool_value_free(val);
			(void) pool_conf_close(conf);
			return ((pid_t)-1);
		}
	} else {
		ival = (pid_t)-1;
	}

	if (mode == PGAS_GET_AND_SET) {
		ival = getpid();
		pool_value_set_int64(val, ival);
		(void) pool_put_property(conf, pe, PID_PROPERTY_NAME, val);
		(void) pool_conf_commit(conf, 0);
	}

	(void) pool_value_free(val);
	(void) pool_conf_close(conf);
	pool_conf_free(conf);

	return ((pid_t)ival);
}

/*
 * Reconfigure the JVM by simply updating a dummy property on the
 * system element to force pool_conf_update() to detect a change.
 */
static void
reconfigure()
{
	JNIEnv *env;
	pool_conf_t *conf;
	pool_elem_t *pe;
	pool_value_t *val;
	const char *err_desc;
	int detach_required = 0;

	if ((conf = pool_conf_alloc()) == NULL) {
		err_desc = pool_strerror(pool_error());
		goto destroy;
	}
	if (pool_conf_open(conf, pool_dynamic_location(), PO_RDWR) != 0) {
		err_desc = pool_strerror(pool_error());
		pool_conf_free(conf);
		goto destroy;
	}

	if ((val = pool_value_alloc()) == NULL) {
		err_desc = pool_strerror(pool_error());
		(void) pool_conf_close(conf);
		pool_conf_free(conf);
		goto destroy;
	}
	pe = pool_conf_to_elem(conf);
	pool_value_set_bool(val, 1);
	if (pool_put_property(conf, pe, "system.poold.sighup", val) !=
	    PO_SUCCESS) {
		err_desc = pool_strerror(pool_error());
		pool_value_free(val);
		(void) pool_conf_close(conf);
		pool_conf_free(conf);
		goto destroy;
	}
	pool_value_free(val);
	(void) pool_rm_property(conf, pe, "system.poold.sighup");
	if (pool_conf_commit(conf, 0) != PO_SUCCESS) {
		err_desc = pool_strerror(pool_error());
		(void) pool_conf_close(conf);
		pool_conf_free(conf);
		goto destroy;
	}
	(void) pool_conf_close(conf);
	pool_conf_free(conf);
	return;
destroy:
	if (jvm) {
		(*jvm)->GetEnv(jvm, (void **)&env, JNI_VERSION_1_2);
		if (env == NULL) {
			detach_required = 1;
			(*jvm)->AttachCurrentThread(jvm, (void **)&env, NULL);
		}
		if (lflag && (*env)->ExceptionOccurred(env))
			(*env)->ExceptionDescribe(env);
		if (detach_required)
			(*jvm)->DetachCurrentThread(jvm);
		(*jvm)->DestroyJavaVM(jvm);
	}
	pu_die(err_desc);
}

/*
 * If SIGHUP is invoked, we should just re-initialize poold. Since
 * there is no easy way to determine when it's safe to re-initialzie
 * poold, simply update a dummy property on the system element to
 * force pool_conf_update() to detect a change.
 *
 * Both SIGTERM and SIGINT are interpreted as instructions to
 * shutdown.
 */
/*ARGSUSED*/
static void *
handle_sig(void *arg)
{
	for (;;) {
		JNIEnv *env;
		jmethodID poold_shutdown_mid;
		int sig;
		char buf[SIG2STR_MAX];
		int detach_required = 0;

		if ((sig = sigwait(&hdl_set)) < 0)
			pu_die("unexpected error: %d\n", errno);
		(void) sig2str(sig, buf);
		switch (sig) {
		case SIGHUP:
			reconfigure();
			break;
		case SIGINT:
		case SIGTERM:
			(void) pthread_mutex_lock(&instance_running_lock);
			if (instance_running) {
				(void) pthread_mutex_unlock(
				    &instance_running_lock);
				(*jvm)->GetEnv(jvm, (void **)&env,
				    JNI_VERSION_1_2);
				if (env == NULL) {
					detach_required = 1;
					(*jvm)->AttachCurrentThread(jvm,
					    (void **)&env, NULL);
				}
				pu_notice("terminating due to signal: SIG%s\n",
				    buf);
				if ((poold_shutdown_mid = (*env)->GetMethodID(
				    env, poold_class, "shutdown", "()V")) !=
				    NULL) {
					(*env)->CallVoidMethod(env,
					    poold_instance,
					    poold_shutdown_mid);
				} else {
					(*env)->ExceptionDescribe(env);
					pu_die("could not invoke"
					    " proper shutdown\n");
				}
				if (detach_required)
					(*jvm)->DetachCurrentThread(jvm);
			} else {
				(void) pthread_mutex_unlock(
				    &instance_running_lock);
				pu_die("terminated with signal: SIG%s\n", buf);
				/*NOTREACHED*/
			}
			break;
		default:
			pu_die("unexpected signal: SIG%s\n", buf);
		}
	}
	/*NOTREACHED*/
	return (NULL);
}

static const char *
pu_getpname(const char *arg0)
{
	char *p;

	/*
	 * Guard against '/' at end of command invocation.
	 */
	for (;;) {
		p = strrchr(arg0, '/');
		if (p == NULL) {
			pname = arg0;
			break;
		} else {
			if (*(p + 1) == '\0') {
				*p = '\0';
				continue;
			}

			pname = p + 1;
			break;
		}
	}

	return (pname);
}

int
main(int argc, char *argv[])
{
	char c;
	char log_severity[16] = "";
	pid_t pid;
	JavaVMInitArgs vm_args;
	JavaVMOption vm_opts[5];
	int nopts = 0;
	const char *classpath;
	const char *libpath;
	size_t len;
	const char *err_desc;
	JNIEnv *env;
	jmethodID poold_getinstancewcl_mid;
	jmethodID poold_run_mid;
	jobject log_severity_string = NULL;
	jobject log_severity_obj = NULL;
	jclass severity_class;
	jmethodID severity_cons_mid;
	jfieldID base_log_fid;
	int explain_ex = 1;
	JavaVM *jvm_tmp;
	pthread_t hdl_thread;

	pname = pu_getpname(argv[0]);
	openlog(pname, 0, LOG_DAEMON);
	(void) chdir("/");

	(void) setlocale(LC_ALL, "");
#if !defined(TEXT_DOMAIN)		/* Should be defined with cc -D. */
#define	TEXT_DOMAIN	"SYS_TEST"	/* Use this only if it wasn't. */
#endif
	(void) textdomain(TEXT_DOMAIN);

	opterr = 0;
	while ((c = getopt(argc, argv, "l:P")) != EOF) {
		switch (c) {
		case 'l':	/* -l option */
			lflag++;
			(void) strlcpy(log_severity, optarg,
			    sizeof (log_severity));
			log_dest = LD_TERMINAL;
			break;
		default:
			usage();
			/*NOTREACHED*/
		}
	}

	/*
	 * Verify no other poold is running.  This condition is checked
	 * again later, but should be checked now since it is more
	 * serious (i.e.  should be reported before) than a lack of
	 * privileges.
	 */
	if (((pid = poold_get_and_set_pid(PGAS_GET_ONLY)) != (pid_t)-1) &&
	    pid != getpid() && kill(pid, 0) == 0)
		pu_die(gettext("poold is already active (process %ld)\n"), pid);

	/*
	 * Check permission
	 */
	if (!priv_ineffect(PRIV_SYS_RES_CONFIG))
		pu_die(gettext(ERR_PRIVILEGE), PRIV_SYS_RES_CONFIG);

	/*
	 * Establish the classpath and LD_LIBRARY_PATH for native
	 * methods, and get the interpreter going.
	 */
	if ((classpath = getenv("POOLD_CLASSPATH")) == NULL) {
		classpath = POOLD_DEF_CLASSPATH;
	} else {
		const char *cur = classpath;

		/*
		 * Check the components to make sure they're absolute
		 * paths.
		 */
		while (cur != NULL && *cur) {
			if (*cur != '/')
				pu_die(gettext(
				    "POOLD_CLASSPATH must contain absolute "
				    "components\n"));
			cur = strchr(cur + 1, ':');
		}
	}
	vm_opts[nopts].optionString = malloc(len = strlen(classpath) +
	    strlen("-Djava.class.path=") + 1);
	(void) strlcpy(vm_opts[nopts].optionString, "-Djava.class.path=", len);
	(void) strlcat(vm_opts[nopts++].optionString, classpath, len);

	if ((libpath = getenv("POOLD_LD_LIBRARY_PATH")) == NULL)
		libpath = POOLD_DEF_LIBPATH;
	vm_opts[nopts].optionString = malloc(len = strlen(libpath) +
	    strlen("-Djava.library.path=") + 1);
	(void) strlcpy(vm_opts[nopts].optionString, "-Djava.library.path=",
	    len);
	(void) strlcat(vm_opts[nopts++].optionString, libpath, len);

	vm_opts[nopts++].optionString = "-Xrs";
	vm_opts[nopts++].optionString = "-enableassertions";

	vm_args.options = vm_opts;
	vm_args.nOptions = nopts;
	vm_args.ignoreUnrecognized = JNI_FALSE;
	vm_args.version = 0x00010002;

	/*
	 * XXX - Forking after the VM is created is desirable to
	 * guarantee reporting of errors, but cannot be done (see
	 * 4919246).
	 *
	 * If invoked by libpool(3LIB), it's set the system.poold.pid
	 * property and forked already.  If invoked directly and -l is
	 * specified, forking is not desired.
	 */
	if (!lflag && pid != getpid())
		switch (fork()) {
		case 0:
			(void) setsid();
			(void) fclose(stdin);
			(void) fclose(stdout);
			(void) fclose(stderr);
			break;
		case -1:
			pu_die(gettext("cannot fork"));
			/*NOTREACHED*/
		default:
			return (E_PO_SUCCESS);
		}

	/*
	 * In order to avoid problems with arbitrary thread selection
	 * when handling asynchronous signals, dedicate a thread to
	 * look after these signals.
	 */
	if (sigemptyset(&hdl_set) < 0 ||
	    sigaddset(&hdl_set, SIGHUP) < 0 ||
	    sigaddset(&hdl_set, SIGTERM) < 0 ||
	    sigaddset(&hdl_set, SIGINT) < 0 ||
	    pthread_sigmask(SIG_BLOCK, &hdl_set, NULL) ||
	    pthread_create(&hdl_thread, NULL, handle_sig, NULL))
		pu_die(gettext("can't install signal handler"));

	/*
	 * Use jvm_tmp when creating the jvm to prevent race
	 * conditions with signal handlers. As soon as the call
	 * returns, assign the global jvm to jvm_tmp.
	 */
	if (JNI_CreateJavaVM(&jvm_tmp, (void **)&env, &vm_args) < 0)
		pu_die(gettext("can't create Java VM"));
	jvm = jvm_tmp;

	/*
	 * Locate the Poold class and construct an instance.  A side
	 * effect of this is that the poold instance's logHelper will be
	 * initialized, establishing loggers for logging errors from
	 * this point on.  (Note, in the event of an unanticipated
	 * exception, poold will invoke die() itself.)
	 */
	err_desc = gettext("JVM-related error initializing poold\n");
	if ((poold_class = (*env)->FindClass(env, POOLD_CLASS_DESC)) == NULL)
		goto destroy;
	if ((poold_getinstancewcl_mid = (*env)->GetStaticMethodID(env,
	    poold_class, "getInstanceWithConsoleLogging", "("
	    CLASS_FIELD_DESC(SEVERITY_CLASS_DESC) ")"
	    CLASS_FIELD_DESC(POOLD_CLASS_DESC))) == NULL)
		goto destroy;
	if ((poold_run_mid = (*env)->GetMethodID(env, poold_class, "run",
	    "()V")) == NULL)
		goto destroy;
	if ((severity_class = (*env)->FindClass(env, SEVERITY_CLASS_DESC))
	    == NULL)
		goto destroy;
	if ((severity_cons_mid = (*env)->GetStaticMethodID(env, severity_class,
	    "getSeverityWithName", "(" CLASS_FIELD_DESC(STRING_CLASS_DESC) ")"
	    CLASS_FIELD_DESC(SEVERITY_CLASS_DESC))) == NULL)
		goto destroy;

	/*
	 * -l <level> was specified, indicating that messages are to be
	 * logged to the console only.
	 */
	if (strlen(log_severity) > 0) {
		if ((log_severity_string = (*env)->NewStringUTF(env,
		    log_severity)) == NULL)
			goto destroy;
		if ((log_severity_obj = (*env)->CallStaticObjectMethod(env,
		    severity_class, severity_cons_mid, log_severity_string)) ==
		    NULL) {
			err_desc = gettext("invalid level specified\n");
			explain_ex = 0;
			goto destroy;
		}
	} else
		log_severity_obj = NULL;

	if ((poold_instance = (*env)->CallStaticObjectMethod(env, poold_class,
	    poold_getinstancewcl_mid, log_severity_obj)) == NULL)
		goto destroy;

	/*
	 * Grab a global reference to poold for use in our signal
	 * handlers.
	 */
	poold_instance = (*env)->NewGlobalRef(env, poold_instance);

	/*
	 * Ready LD_JAVA logging.
	 */
	err_desc = gettext("cannot initialize logging\n");
	if ((log_severity_string = (*env)->NewStringUTF(env, "err")) == NULL)
		goto destroy;
	if (!(severity_err = (*env)->CallStaticObjectMethod(env, severity_class,
	    severity_cons_mid, log_severity_string)))
		goto destroy;
	if (!(severity_err = (*env)->NewGlobalRef(env, severity_err)))
		goto destroy;

	if ((log_severity_string = (*env)->NewStringUTF(env, "notice")) == NULL)
		goto destroy;
	if (!(severity_notice = (*env)->CallStaticObjectMethod(env,
	    severity_class, severity_cons_mid, log_severity_string)))
		goto destroy;
	if (!(severity_notice = (*env)->NewGlobalRef(env, severity_notice)))
		goto destroy;

	if (!(base_log_fid = (*env)->GetStaticFieldID(env, poold_class,
	    "BASE_LOG", CLASS_FIELD_DESC(LOGGER_CLASS_DESC))))
		goto destroy;
	if (!(base_log = (*env)->GetStaticObjectField(env, poold_class,
	    base_log_fid)))
		goto destroy;
	if (!(base_log = (*env)->NewGlobalRef(env, base_log)))
		goto destroy;
	if (!(log_mid = (*env)->GetMethodID(env, (*env)->GetObjectClass(env,
	    base_log), "log", "(" CLASS_FIELD_DESC(LEVEL_CLASS_DESC)
	    CLASS_FIELD_DESC(STRING_CLASS_DESC) ")V")))
		goto destroy;
	log_dest = LD_JAVA;

	/*
	 * Now we're ready to start poold.  Store our pid in the pools
	 * configuration to mark that an instance of poold is active,
	 * then invoke Poold.run(), which does not normally return.
	 *
	 * Note that the ignoreUpdates variable in Poold is used to
	 * allow Poold to ignore the pools configuration update that
	 * this change triggers. If this code is ever modified to
	 * remove or modify this logic, then the Poold class must also
	 * be modified to keep the actions synchronized.
	 */

	if (((pid = poold_get_and_set_pid(PGAS_GET_AND_SET)) != (pid_t)-1) &&
	    pid != getpid() && kill(pid, 0) == 0)
		pu_die(gettext("poold is already active (process %ld)\n"), pid);

	(void) pthread_mutex_lock(&instance_running_lock);
	instance_running = 1;
	(void) pthread_mutex_unlock(&instance_running_lock);
	(*env)->CallVoidMethod(env, poold_instance, poold_run_mid);

	if ((*env)->ExceptionOccurred(env))
		goto destroy;

	(*jvm)->DestroyJavaVM(jvm);
	return (E_PO_SUCCESS);

destroy:
	if (lflag && explain_ex && (*env)->ExceptionOccurred(env))
		(*env)->ExceptionDescribe(env);
	(*jvm)->DestroyJavaVM(jvm);
	pu_die(err_desc);
}