/*
 * LDAP plugin. TODO: loops with and without opening the connection each
 * time? $Id$
 */

#define IN_PLUGIN
#include "../../echoping.h"
#ifdef HAVE_CONFIG_H
#include "../../config.h"
#include "config.h"
#endif
#include <ldap.h>

const char     *request = NULL;
const char     *base = NULL;
int             scope = LDAP_SCOPE_BASE;
const char     *hostname;
int             port = 0;
LDAP           *session;
poptContext     ldap_poptcon;
echoping_options global_options;

void
ldap_usage(const char *msg)
{
	if (msg) {
		printf("LDAP plugin error: %s\n", msg);
	}
	poptPrintUsage(ldap_poptcon, stdout, 0);
	exit(1);
}

char           *
init(const int argc, const char **argv,
     const echoping_options global_external_options)
{
	int             value;
	char           *msg = malloc(MAX_LINE);
	char           *rest, *port_text;
	char           *scope_string = NULL;
	/* popt variables */
	struct poptOption options[] = {
		{"request", 'r', POPT_ARG_STRING, &request, 0,
		 "Request (filter) to send to the LDAP server", "r"},
		{"base", 'b', POPT_ARG_STRING, &base, 0,
		 "Base of the LDAP tree", "b"},
		{"scope", 's', POPT_ARG_STRING, &scope_string, 0,
		 "Scope of the search in the LDAP tree (sub, one or base)", "s"},
		{"port", 'p', POPT_ARG_INT, &port, 0,
		 "TCP port to connect to the LDAP server", "p"},
		POPT_AUTOHELP POPT_TABLEEND
	};
	global_options = global_external_options;
	if (global_options.udp)
		err_quit("UDP makes no sense for a LDAP connection");
	ldap_poptcon = poptGetContext(NULL, argc,
				      argv, options, POPT_CONTEXT_KEEP_FIRST);
	while ((value = poptGetNextOpt(ldap_poptcon)) > 0) {
	}
	if (value < -1) {
		sprintf(msg, "%s: %s",
			poptBadOption(ldap_poptcon, POPT_BADOPTION_NOALIAS),
			poptStrerror(value));
		ldap_usage(msg);
	}
	if (port == 0)
		port = LDAP_PORT;
	hostname = poptGetArg(ldap_poptcon);
	rest = poptGetArg(ldap_poptcon);
	if (rest != NULL) {
		fprintf(stderr, "%s: ", rest);
		ldap_usage("Additional arguments");
	}
	if (base == NULL)
		base = "";
	if (request == NULL || !strcmp(request, ""))
		request = "(objectclass=*)";	/* Default mentioned in OpenLDAP
						 * documentation.  Joerg Roth fears
						 * that it may trigger "Size limit
						 * exceeded" if there are many
						 * objects at this node. RFC 4515
						 * seems silent here. */
	if (scope_string != NULL) {
		scope_string = (char *) to_upper(scope_string);
		if (!strcmp(scope_string, "BASE"))
			scope = LDAP_SCOPE_BASE;
		else if (!strcmp(scope_string, "SUB"))
			scope = LDAP_SCOPE_SUBTREE;
		else if (!strcmp(scope_string, "ONE"))
			scope = LDAP_SCOPE_ONELEVEL;
		else
			err_quit("Invalid scope \"%s\"", scope_string);
	}
	if (port == LDAP_PORT) {
		return "ldap";
	} else {
		port_text = malloc(99);
		sprintf(port_text, "%d", port);
		return port_text;
	}
}

void
start()
{
	int             result;
	LDAPMessage    *response;

	session = ldap_init(hostname, port);
	if (session == NULL)
		err_sys("Cannot initialize LDAP");
	/* TODO: allow non-anonymous connections, with ldap_bind_simple_s */
	/* 
	 * Unfortunately, ldap_init does not connect to the LDAP server. So
	 * connection errors (e.g. firewall), will not be detected here and
	 * loop will go on.
	 * 
	 * To quote the man page: ldap_init() acts just like ldap_open(), but
	 * does not open a connection to the LDAP server.  The actual
	 * connection open will occur when the first operation is attempted.
	 * At this time, ldap_init() is preferred.  ldap_open() will be
	 * depreciated in a later release.
	 * 
	 * So, we perform a dummy search immediately.
	 *  
	 * See #1879652 for why we use "dummystuff" and not "*"
	 *
	 */
	result = ldap_search_s(session, base, LDAP_SCOPE_ONELEVEL, "(objectClass=dummystuff)", NULL,	/* Return
													 * * all * 
													 * *
													 * attributes 
													 */
			       1, &response);
	if (result != 0) {
		err_quit
		    ("Cannot connect to %s (no LDAP server or wrong base, probably): %s",
		     hostname, ldap_err2string(result));
	}
}

int
execute()
{
	int             result;
	LDAPMessage    *response;
	result = ldap_search_s(session, base, scope, request, NULL,	/* Return
									 * all
									 * attributes 
									 */
			       0,	/* Return attribute types *and* values */
			       &response);
	if (result != 0) {
		err_ret("Cannot search \"%s\": %s", request,
			ldap_err2string(result));
		return -1;
	}
	if (global_options.verbose)
		printf("Retrieved: %d entries\n",
		       ldap_count_entries(session, response));
	return 0;
}

void
terminate()
{
	ldap_unbind_s(session);
}