/*
 * Kamailio LDAP Module
 *
 * Copyright (C) 2007 University of North Carolina
 *
 * Original author: Christian Schlatter, cs@unc.edu
 *
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version
 *
 * Kamailio is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */


#include <stdio.h>
#include <string.h>
#include <sys/time.h>

#include "../../core/ut.h"
#include "../../core/parser/hf.h"
#include "../../core/sr_module.h"
#include "../../core/pvar.h"
#include "../../core/mod_fix.h"
#include "../../core/mem/mem.h"

#include "ld_session.h"
#include "ldap_exp_fn.h"
#include "api.h"
#include "ldap_connect.h"
#include "ldap_api_fn.h"
#include "iniparser.h"

MODULE_VERSION

/*
* Module management function prototypes
*/
static int mod_init(void);
static void destroy(void);
static int child_init(int rank);

/*
* fixup functions
*/
static int ldap_result_fixup(void **param, int param_no);
static int ldap_filter_url_encode_fixup(void **param, int param_no);
static int ldap_result_check_fixup(void **param, int param_no);

/*
* exported functions
*/

static int w_ldap_search(struct sip_msg *msg, char *ldap_url, char *param);
static int w_ldap_result1(struct sip_msg *msg, char *src, char *param);
static int w_ldap_result2(struct sip_msg *msg, char *src, char *subst);
static int w_ldap_result_next(struct sip_msg *msg, char *foo, char *bar);
static int w_ldap_filter_url_encode(
		struct sip_msg *msg, char *filter_component, char *dst_avp_name);
static int w_ldap_result_check_1(
		struct sip_msg *msg, char *attr_name_check_str, char *param);
static int w_ldap_result_check_2(
		struct sip_msg *msg, char *attr_name_check_str, char *attr_val_re);


/*
* Default module parameter values
*/
#define DEF_LDAP_CONFIG "/usr/local/etc/kamailio/ldap.cfg"

/*
* Module parameter variables
*/
str ldap_config = str_init(DEF_LDAP_CONFIG);
static dictionary *config_vals = NULL;

/*
 * Exported functions
 */
/* clang-format off */
static cmd_export_t cmds[] = {
	{"ldap_search",            (cmd_function)w_ldap_search,            1,
		fixup_spve_null, 0,
		REQUEST_ROUTE|FAILURE_ROUTE|BRANCH_ROUTE|ONREPLY_ROUTE|LOCAL_ROUTE},
	{"ldap_result",            (cmd_function)w_ldap_result1,           1,
		ldap_result_fixup, 0,
		REQUEST_ROUTE|FAILURE_ROUTE|BRANCH_ROUTE|ONREPLY_ROUTE|LOCAL_ROUTE},
	{"ldap_result",            (cmd_function)w_ldap_result2,           2,
		ldap_result_fixup, 0,
		REQUEST_ROUTE|FAILURE_ROUTE|BRANCH_ROUTE|ONREPLY_ROUTE|LOCAL_ROUTE},
	{"ldap_result_next",       (cmd_function)w_ldap_result_next,       0,
		0, 0,
		REQUEST_ROUTE|FAILURE_ROUTE|BRANCH_ROUTE|ONREPLY_ROUTE|LOCAL_ROUTE},
	{"ldap_result_check",      (cmd_function)w_ldap_result_check_1,    1,
		ldap_result_check_fixup, 0,
		REQUEST_ROUTE|FAILURE_ROUTE|BRANCH_ROUTE|ONREPLY_ROUTE|LOCAL_ROUTE},
	{"ldap_result_check",      (cmd_function)w_ldap_result_check_2,    2,
		ldap_result_check_fixup, 0,
		REQUEST_ROUTE|FAILURE_ROUTE|BRANCH_ROUTE|ONREPLY_ROUTE|LOCAL_ROUTE},
	{"ldap_filter_url_encode", (cmd_function)w_ldap_filter_url_encode, 2,
		ldap_filter_url_encode_fixup, 0,
		REQUEST_ROUTE|FAILURE_ROUTE|BRANCH_ROUTE|ONREPLY_ROUTE|LOCAL_ROUTE},
	{"load_ldap",              (cmd_function)load_ldap,  0,
		0, 0, 0},
	{0, 0, 0, 0, 0, 0}
};


/*
* Exported parameters
*/
static param_export_t params[] = {

	{"config_file",          PARAM_STR, &ldap_config},
	{0, 0, 0}
};


/*
* Module interface
*/
struct module_exports exports = {
	"ldap",          /* module name */
	DEFAULT_DLFLAGS, /* dlopen flags */
	cmds,            /* cmd (cfg function) exports */
	params,          /* param exports */
	0,               /* RPC method exports */
	0,               /* pseudo-variables exports */
	0,               /* response handling function */
	mod_init,        /* module init function */
	child_init,      /* per-child init function */
	destroy          /* module destroy function */
};
/* clang-format on */


static int child_init(int rank)
{
	int i = 0, ld_count = 0;
	char *ld_name;

	/* don't do anything for non-worker processes */
	if(rank == PROC_INIT || rank == PROC_MAIN || rank == PROC_TCP_MAIN)
		return 0;

	/*
	* build ld_sessions and connect all sessions
	*/
	ld_count = iniparser_getnsec(config_vals);
	for(i = 0; i < ld_count; i++) {
		ld_name = iniparser_getsecname(config_vals, i);
		if(add_ld_session(ld_name, NULL, config_vals) != 0) {
			LM_ERR("[%s]: add_ld_session failed\n", ld_name);
			return -1;
		}

		if(ldap_connect(ld_name) != 0) {
			LM_ERR("[%s]: failed to connect to LDAP host(s)\n", ld_name);
			ldap_disconnect(ld_name);
			return -1;
		}
	}

	return 0;
}


static int mod_init(void)
{
	int ld_count = 0, i = 0;
	char *section_name;
	char *ldap_version;

	/*
	* read config file
	*/
	if(ldap_config.len <= 0) {
		LM_ERR("config_file is empty - this module param is mandatory\n");
		return -2;
	}
	if((config_vals = iniparser_new(ldap_config.s)) == NULL) {
		LM_ERR("failed to read config_file [%s]\n", ldap_config.s);
		return -2;
	}
	if((ld_count = iniparser_getnsec(config_vals)) < 1) {
		LM_ERR("no section found in config_file [%s]\n", ldap_config.s);
		return -2;
	}
	/* check if mandatory settings are present */
	for(i = 0; i < ld_count; i++) {
		section_name = iniparser_getsecname(config_vals, i);
		if(strlen(section_name) > 255) {
			LM_ERR("config_file section name [%s]"
				   " longer than allowed 255 characters",
					section_name);
			return -2;
		}
		if(!iniparser_find_entry(config_vals,
				   get_ini_key_name(section_name, CFG_N_LDAP_HOST))) {
			LM_ERR("mandatory %s not defined in [%s]\n", CFG_N_LDAP_HOST,
					section_name);
			return -2;
		}
	}

	/*
	* print ldap version string
	*/
	if(ldap_get_vendor_version(&ldap_version) != 0) {
		LM_ERR("ldap_get_vendor_version failed\n");
		return -2;
	}
	LM_INFO("%s\n", ldap_version);

	return 0;
}


static void destroy(void)
{
	/* ldap_unbind */
	free_ld_sessions();

	/* free config file memory */
	iniparser_free(config_vals);
}


/*
* EXPORTED functions
*/

static int w_ldap_search(struct sip_msg *msg, char *ldap_url, char *param)
{
	str ldap_url_val = STR_NULL;

	if(fixup_get_svalue(msg, (gparam_t*)ldap_url, &ldap_url_val)<0) {
		LM_ERR("failed to get ldap url parameter\n");
		return -1;
	}
	return ldap_search_impl(msg, &ldap_url_val);
}

static int w_ldap_result1(struct sip_msg *msg, char *src, char *param)
{
	return ldap_write_result(msg, (struct ldap_result_params *)src, NULL);
}

static int w_ldap_result2(struct sip_msg *msg, char *src, char *subst)
{
	return ldap_write_result(
			msg, (struct ldap_result_params *)src, (struct subst_expr *)subst);
}

static int w_ldap_result_next(struct sip_msg *msg, char *foo, char *bar)
{
	return ldap_result_next();
}

static int w_ldap_filter_url_encode(
		struct sip_msg *msg, char *filter_component, char *dst_avp_name)
{
	return ldap_filter_url_encode(
			msg, (pv_elem_t *)filter_component, (pv_spec_t *)dst_avp_name);
}

static int w_ldap_result_check_1(
		struct sip_msg *msg, char *attr_name_check_str, char *param)
{
	return ldap_result_check(
			msg, (struct ldap_result_check_params *)attr_name_check_str, NULL);
}

static int w_ldap_result_check_2(
		struct sip_msg *msg, char *attr_name_check_str, char *attr_val_re)
{
	return ldap_result_check(msg,
			(struct ldap_result_check_params *)attr_name_check_str,
			(struct subst_expr *)attr_val_re);
}

/*
* FIXUP functions
*/

static int ldap_result_fixup(void **param, int param_no)
{
	struct ldap_result_params *lp;
	struct subst_expr *se;
	str subst;
	char *arg_str, *dst_avp_str, *dst_avp_val_type_str;
	char *p;
	str s;
	int dst_avp_val_type = 0;

	if(param_no == 1) {
		arg_str = (char *)*param;
		if((dst_avp_str = strchr(arg_str, '/')) == 0) {
			/* no / found in arg_str */
			LM_ERR("invalid first argument [%s]\n", arg_str);
			return E_UNSPEC;
		}
		*(dst_avp_str++) = 0;

		if((dst_avp_val_type_str = strchr(dst_avp_str, '/'))) {
			*(dst_avp_val_type_str++) = 0;
			if(!strcmp(dst_avp_val_type_str, "int")) {
				dst_avp_val_type = 1;
			} else if(strcmp(dst_avp_val_type_str, "str")) {
				LM_ERR("invalid avp_type [%s]\n", dst_avp_val_type_str);
				return E_UNSPEC;
			}
		}

		lp = (struct ldap_result_params *)pkg_malloc(
				sizeof(struct ldap_result_params));
		if(lp == NULL) {
			LM_ERR("no memory\n");
			return E_OUT_OF_MEM;
		}
		memset(lp, 0, sizeof(struct ldap_result_params));

		lp->ldap_attr_name.s = arg_str;
		lp->ldap_attr_name.len = strlen(arg_str);

		lp->dst_avp_val_type = dst_avp_val_type;
		s.s = dst_avp_str;
		s.len = strlen(s.s);
		p = pv_parse_spec(&s, &lp->dst_avp_spec);
		if(p == 0) {
			pkg_free(lp);
			LM_ERR("parse error for [%s]\n", dst_avp_str);
			return E_UNSPEC;
		}
		if(lp->dst_avp_spec.type != PVT_AVP) {
			pkg_free(lp);
			LM_ERR("bad attribute name [%s]\n", dst_avp_str);
			return E_UNSPEC;
		}
		*param = (void *)lp;

	} else if(param_no == 2) {
		subst.s = *param;
		subst.len = strlen(*param);
		se = subst_parser(&subst);
		if(se == 0) {
			LM_ERR("bad subst re [%s]\n", (char *)*param);
			return E_BAD_RE;
		}
		*param = (void *)se;
	}

	return 0;
}

static int ldap_result_check_fixup(void **param, int param_no)
{
	struct ldap_result_check_params *lp;
	struct subst_expr *se;
	str subst;
	str s;
	char *arg_str, *check_str;
	int arg_str_len;

	if(param_no == 1) {
		arg_str = (char *)*param;
		arg_str_len = strlen(arg_str);
		if((check_str = strchr(arg_str, '/')) == 0) {
			/* no / found in arg_str */
			LM_ERR("invalid first argument [%s] (no '/' found)\n", arg_str);
			return E_UNSPEC;
		}
		*(check_str++) = 0;

		lp = (struct ldap_result_check_params *)pkg_malloc(
				sizeof(struct ldap_result_check_params));
		if(lp == NULL) {
			LM_ERR("no memory\n");
			return E_OUT_OF_MEM;
		}
		memset(lp, 0, sizeof(struct ldap_result_check_params));

		lp->ldap_attr_name.s = arg_str;
		lp->ldap_attr_name.len = strlen(arg_str);

		if(lp->ldap_attr_name.len + 1 == arg_str_len) {
			/* empty check_str */
			lp->check_str_elem_p = 0;
		} else {
			s.s = check_str;
			s.len = strlen(s.s);
			if(pv_parse_format(&s, &(lp->check_str_elem_p)) < 0) {
				LM_ERR("pv_parse_format failed\n");
				pkg_free(lp);
				return E_OUT_OF_MEM;
			}
		}
		*param = (void *)lp;
	} else if(param_no == 2) {
		subst.s = *param;
		subst.len = strlen(*param);
		se = subst_parser(&subst);
		if(se == 0) {
			LM_ERR("bad subst re [%s]\n", (char *)*param);
			return E_BAD_RE;
		}
		*param = (void *)se;
	}

	return 0;
}

static int ldap_filter_url_encode_fixup(void **param, int param_no)
{
	pv_elem_t *elem_p;
	pv_spec_t *spec_p;
	str s;

	if(param_no == 1) {
		s.s = (char *)*param;
		if(s.s == 0 || s.s[0] == 0) {
			elem_p = 0;
		} else {
			s.len = strlen(s.s);
			if(pv_parse_format(&s, &elem_p) < 0) {
				LM_ERR("pv_parse_format failed\n");
				return E_OUT_OF_MEM;
			}
		}
		*param = (void *)elem_p;
	} else if(param_no == 2) {
		spec_p = (pv_spec_t *)pkg_malloc(sizeof(pv_spec_t));
		if(spec_p == NULL) {
			LM_ERR("no memory\n");
			return E_OUT_OF_MEM;
		}
		s.s = (char *)*param;
		s.len = strlen(s.s);
		if(pv_parse_spec(&s, spec_p) == 0) {
			pkg_free(spec_p);
			LM_ERR("parse error for [%s]\n", (char *)*param);
			return E_UNSPEC;
		}
		if(spec_p->type != PVT_AVP) {
			pkg_free(spec_p);
			LM_ERR("bad attribute name"
				   " [%s]\n",
					(char *)*param);
			return E_UNSPEC;
		}
		*param = (void *)spec_p;
	}

	return 0;
}