/*
 * $Id: permissions.c 1808 2007-03-10 17:36:19Z bogdan_iancu $
 *
 * PERMISSIONS module
 *
 * Copyright (C) 2003 Miklós Tirpák (mtirpak@sztaki.hu)
 * Copyright (C) 2003 iptel.org
 * Copyright (C) 2003-2006 Juha Heinanen
 *
 * This file is part of openser, a free SIP server.
 *
 * openser 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
 *
 * openser 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */
 
#include <stdio.h>
#include "permissions.h"
#include "parse_config.h"
#include "trusted.h"
#include "address.h"
#include "hash.h"
#include "mi.h"
#include "../../mem/mem.h"
#include "../../parser/parse_from.h"
#include "../../parser/parse_uri.h"
#include "../../parser/parse_refer_to.h"
#include "../../parser/contact/parse_contact.h"
#include "../../str.h"
#include "../../dset.h"
#include "../../globals.h"
#include "../../items.h"
#include "../../ut.h"

MODULE_VERSION

static rule_file_t allow[MAX_RULE_FILES]; /* Parsed allow files */
static rule_file_t deny[MAX_RULE_FILES];  /* Parsed deny files */
static int rules_num;  /* Number of parsed allow/deny files */


/* Module parameter variables */
static char* default_allow_file = DEFAULT_ALLOW_FILE;
static char* default_deny_file = DEFAULT_DENY_FILE;
static char* allow_suffix = ".allow";
static char* deny_suffix = ".deny";


/* for allow_trusted and allow_address function */
char* db_url = 0;                  /* Don't connect to the database by default */

/* for allow_trusted function */
int db_mode = DISABLE_CACHE;	   /* Database usage mode: 0=no cache, 1=cache */
char* trusted_table = "trusted";   /* Name of trusted table */
char* source_col = "src_ip";       /* Name of source address column */
char* proto_col = "proto";         /* Name of protocol column */
char* from_col = "from_pattern";   /* Name of from pattern column */
char* tag_col = "tag";             /* Name of tag column */
char* tag_avp_param = 0;           /* Peer tag AVP spec */

/* for allow_address function */
char* address_table = "address";   /* Name of address table */
char* grp_col = "grp";             /* Name of address group column */
char* ip_addr_col = "ip_addr";     /* Name of ip address column */
char* mask_col = "mask";           /* Name of mask column */
char* port_col = "port";           /* Name of port column */


/*
 * By default we check all branches
 */
static int check_all_branches = 1;


/*  
 * Convert the name of the files into table index
 */
static int load_fixup(void** param, int param_no);

/*
 * Convert the name of the file into table index, this
 * function takes just one name, appends .allow and .deny
 * to and and the rest is same as in load_fixup
 */
static int single_fixup(void** param, int param_no);

/*
 * Fixes up allow_addess() parameters
 */
static int address_fixup(void** param, int param_no);

/*
 * Convert int or pvar parameter into int_or_pvar struct
 */
static int int_or_pvar_fixup(void** param, int param_no);


/*
 * Parse pseudo variable parameter
 */
static int double_fixup(void** param, int param_no);

static int allow_routing_0(struct sip_msg* msg, char* str1, char* str2);
static int allow_routing_1(struct sip_msg* msg, char* basename, char* str2);
static int allow_routing_2(struct sip_msg* msg, char* allow_file, char* deny_file);
static int allow_register_1(struct sip_msg* msg, char* basename, char* s);
static int allow_register_2(struct sip_msg* msg, char* allow_file, char* deny_file);
static int allow_uri(struct sip_msg* msg, char* basename, char* uri);

static int mod_init(void);
static void mod_exit(void);
static int child_init(int rank);
static int mi_trusted_child_init();
static int mi_addr_child_init();


/* Exported functions */
static cmd_export_t cmds[] = {
	{"allow_routing",  allow_routing_0,  0, 0,
		REQUEST_ROUTE | FAILURE_ROUTE},
	{"allow_routing",  allow_routing_1,  1, single_fixup,
		REQUEST_ROUTE | FAILURE_ROUTE},
	{"allow_routing",  allow_routing_2,  2, load_fixup,
		REQUEST_ROUTE | FAILURE_ROUTE},
	{"allow_register", allow_register_1, 1, single_fixup,
		REQUEST_ROUTE | FAILURE_ROUTE},
	{"allow_register", allow_register_2, 2, load_fixup,
		REQUEST_ROUTE | FAILURE_ROUTE},
	{"allow_trusted",  allow_trusted,    0, 0,
		REQUEST_ROUTE | FAILURE_ROUTE},
	{"allow_uri", allow_uri, 2, double_fixup,
		REQUEST_ROUTE | FAILURE_ROUTE},
	{"set_address_group", set_address_group, 1, int_or_pvar_fixup,
		REQUEST_ROUTE | FAILURE_ROUTE},
	{"allow_address", allow_address, 2, address_fixup,
		REQUEST_ROUTE | FAILURE_ROUTE},
	{"allow_source_address", allow_source_address, 1, int_or_pvar_fixup,
		REQUEST_ROUTE | FAILURE_ROUTE},
	{0, 0, 0, 0, 0}
};

/* Exported parameters */
static param_export_t params[] = {
	{"default_allow_file", STR_PARAM, &default_allow_file},
	{"default_deny_file",  STR_PARAM, &default_deny_file },
	{"check_all_branches", INT_PARAM, &check_all_branches},
	{"allow_suffix",       STR_PARAM, &allow_suffix      },
	{"deny_suffix",        STR_PARAM, &deny_suffix       },
	{"db_url",             STR_PARAM, &db_url            },
	{"db_mode",            INT_PARAM, &db_mode           },
	{"trusted_table",      STR_PARAM, &trusted_table     },
	{"source_col",         STR_PARAM, &source_col        },
	{"proto_col",          STR_PARAM, &proto_col         },
	{"from_col",           STR_PARAM, &from_col          },
	{"tag_col",            STR_PARAM, &tag_col           },
	{"peer_tag_avp",       STR_PARAM, &tag_avp_param     },
	{"address_table",      STR_PARAM, &address_table     },
	{"grp_col",            STR_PARAM, &grp_col           },
	{"ip_addr_col",        STR_PARAM, &ip_addr_col       },
	{"mask_col",           STR_PARAM, &mask_col          },
	{"port_col",           STR_PARAM, &port_col          },
	{0, 0, 0}
};

/*
 * Exported MI functions
 */
static mi_export_t mi_cmds[] = {
	{ MI_TRUSTED_RELOAD,  mi_trusted_reload,  MI_NO_INPUT_FLAG,  0,
													mi_trusted_child_init },
	{ MI_TRUSTED_DUMP,    mi_trusted_dump,    MI_NO_INPUT_FLAG,  0,  0 },
	{ MI_ADDRESS_RELOAD,  mi_address_reload,  MI_NO_INPUT_FLAG,  0,
													mi_addr_child_init },
	{ MI_ADDRESS_DUMP,    mi_address_dump,    MI_NO_INPUT_FLAG,  0,  0 },
	{ MI_SUBNET_DUMP,     mi_subnet_dump,     MI_NO_INPUT_FLAG,  0,  0 },
	{ 0, 0, 0, 0, 0 }
};

/* Module interface */
struct module_exports exports = {
	"permissions",
	DEFAULT_DLFLAGS, /* dlopen flags */
	cmds,      /* Exported functions */
	params,    /* Exported parameters */
	0,         /* exported statistics */
	mi_cmds,   /* exported MI functions */
	0,         /* exported pseudo-variables */
	mod_init,  /* module initialization function */
	0,         /* response function */
	mod_exit,  /* destroy function */
	child_init /* child initialization function */
};


/*
 * Extract path (the beginning of the string
 * up to the last / character
 * Returns length of the path
 */
static int get_path(char* pathname)
{
	char* c;
	if (!pathname) return 0;
	
	c = strrchr(pathname, '/');
	if (!c) return 0;

	return c - pathname + 1;
}


/*
 * Prepend path if necessary
 */
static char* get_pathname(char* name)
{
	char* buffer;
	int path_len, name_len;

	if (!name) return 0;
	
	name_len = strlen(name);
	if (strchr(name, '/')) {
		buffer = (char*)pkg_malloc(name_len + 1);
		if (!buffer) goto err;
		strcpy(buffer, name);
		return buffer;
	} else {
		path_len = get_path(cfg_file);
		buffer = (char*)pkg_malloc(path_len + name_len + 1);
		if (!buffer) goto err;
		memcpy(buffer, cfg_file, path_len);
		memcpy(buffer + path_len, name, name_len);
		buffer[path_len + name_len] = '\0';
		return buffer;
	}

 err:
	LOG(L_ERR, "get_pathname(): No memory left\n");
	return 0;
}


/*
 * If the file pathname has been parsed already then the
 * function returns its index in the tables, otherwise it
 * returns -1 to indicate that the file needs to be read
 * and parsed yet
 */
static int find_index(rule_file_t* array, char* pathname)
{
	int i;

	for(i = 0; i < rules_num; i++) {
		if (!strcmp(pathname, array[i].filename)) return i;
	}

	return -1;
}


/*
 * Return URI without all the bells and whistles, that means only
 * sip:username@domain, resulting buffer is statically allocated and
 * zero terminated
 */
static char* get_plain_uri(const str* uri)
{
	static char buffer[EXPRESSION_LENGTH + 1];
	struct sip_uri puri;
	int len;

	if (!uri) return 0;

	if (parse_uri(uri->s, uri->len, &puri) < 0) {
		LOG(L_ERR, "get_plain_uri(): Error while parsing URI\n");
		return 0;
	}
	
	if (puri.user.len) {
		len = puri.user.len + puri.host.len + 5;
	} else {
		len = puri.host.len + 4;
	}

	if (len > EXPRESSION_LENGTH) {
		LOG(L_ERR, "allow_register(): (module permissions) Request-URI is too long: %d chars\n", len);
		return 0;
	}
	
	strcpy(buffer, "sip:");
	if (puri.user.len) {
		memcpy(buffer + 4, puri.user.s, puri.user.len);
	        buffer[puri.user.len + 4] = '@';
		memcpy(buffer + puri.user.len + 5, puri.host.s, puri.host.len);
	} else {
		memcpy(buffer + 4, puri.host.s, puri.host.len);
	}

	buffer[len] = '\0';
	return buffer;
}


/*
 * determines the permission of the call
 * return values:
 * -1:	deny
 * 1:	allow
 */
static int check_routing(struct sip_msg* msg, int idx) 
{
	struct hdr_field *from;
	int len, q;
	static char from_str[EXPRESSION_LENGTH+1];
	static char ruri_str[EXPRESSION_LENGTH+1];
	char* uri_str;
	str branch;
	int br_idx;

	/* turn off control, allow any routing */
	if ((!allow[idx].rules) && (!deny[idx].rules)) {
		DBG("check_routing(): No rules => allow any routing\n");
		return 1;
	}
	
	/* looking for FROM HF */
        if ((!msg->from) && (parse_headers(msg, HDR_FROM_F, 0) == -1)) {
                LOG(L_ERR, "check_routing(): Error while parsing message\n");
                return -1;
        }
	
	if (!msg->from) {
		LOG(L_ERR, "check_routing(): FROM header field not found\n");
		return -1;
	}
	
	/* we must call parse_from_header explicitly */
        if ((!(msg->from)->parsed) && (parse_from_header(msg) < 0)) {
                LOG(L_ERR, "check_routing(): Error while parsing From body\n");
                return -1;
        }
	
	from = msg->from;
	len = ((struct to_body*)from->parsed)->uri.len;
	if (len > EXPRESSION_LENGTH) {
                LOG(L_ERR, "check_routing(): From header field is too long: %d chars\n", len);
                return -1;
	}
	strncpy(from_str, ((struct to_body*)from->parsed)->uri.s, len);
	from_str[len] = '\0';
	
	/* looking for request URI */
	if (parse_sip_msg_uri(msg) < 0) {
	        LOG(L_ERR, "check_routing(): uri parsing failed\n");
	        return -1;
	}
	
	len = msg->parsed_uri.user.len + msg->parsed_uri.host.len + 5;
	if (len > EXPRESSION_LENGTH) {
                LOG(L_ERR, "check_routing(): Request URI is too long: %d chars\n", len);
                return -1;
	}
	
	strcpy(ruri_str, "sip:");
	memcpy(ruri_str + 4, msg->parsed_uri.user.s, msg->parsed_uri.user.len);
	ruri_str[msg->parsed_uri.user.len + 4] = '@';
	memcpy(ruri_str + msg->parsed_uri.user.len + 5, msg->parsed_uri.host.s, msg->parsed_uri.host.len);
	ruri_str[len] = '\0';
	
        DBG("check_routing(): looking for From: %s Request-URI: %s\n", from_str, ruri_str);
	     /* rule exists in allow file */
	if (search_rule(allow[idx].rules, from_str, ruri_str)) {
		if (check_all_branches) goto check_branches;
    		DBG("check_routing(): allow rule found => routing is allowed\n");
		return 1;
	}
	
	/* rule exists in deny file */
	if (search_rule(deny[idx].rules, from_str, ruri_str)) {
		DBG("check_routing(): deny rule found => routing is denied\n");
		return -1;
	}

	if (!check_all_branches) {
		DBG("check_routing(): Neither allow nor deny rule found => routing is allowed\n");
		return 1;
	}

 check_branches:
	for( br_idx=0 ; (branch.s=get_branch(br_idx,&branch.len,&q,0,0,0,0))!=0 ;
	br_idx++ ) {
		uri_str = get_plain_uri(&branch);
		if (!uri_str) {
			LOG(L_ERR, "check_uri(): Error while extracting plain URI\n");
			return -1;
		}
		DBG("check_routing: Looking for From: %s Branch: %s\n", from_str, uri_str);
		
		if (search_rule(allow[idx].rules, from_str, uri_str)) {
			continue;
		}
		
		if (search_rule(deny[idx].rules, from_str, uri_str)) {
			LOG(LOG_INFO, "check_routing(): Deny rule found for one of branches => routing is denied\n");
			return -1;
		}
	}
	
	LOG(LOG_INFO, "check_routing(): Check of branches passed => routing is allowed\n");
	return 1;
}


/*  
 * Convert the name of the files into table index
 */
static int load_fixup(void** param, int param_no)
{
	char* pathname;
	int idx;
	rule_file_t* table;

	if (param_no == 1) {
		table = allow;
	} else {
		table = deny;
	}

	pathname = get_pathname(*param);
	idx = find_index(table, pathname);

	if (idx == -1) {
		     /* Not opened yet, open the file and parse it */
		table[rules_num].filename = pathname;
		table[rules_num].rules = parse_config_file(pathname);
		if (table[rules_num].rules) {
			LOG(L_INFO, "load_fixup(): File (%s) parsed\n", pathname);
		} else {
			LOG(L_WARN, "load_fixup(): File (%s) not found => empty rule set\n", pathname);
		}
		*param = (void*)(long)rules_num;
		if (param_no == 2) rules_num++;
	} else {
		     /* File already parsed, re-use it */
		LOG(L_INFO, "load_fixup(): File (%s) already loaded, re-using\n", pathname);
		pkg_free(pathname);
		*param = (void*)(long)idx;
	}

	return 0;
}


/*
 * Convert the name of the file into table index
 */
static int single_fixup(void** param, int param_no)
{
	char* buffer;
	void* tmp;
	int param_len, ret, suffix_len;

	if (param_no != 1) return 0;

	param_len = strlen((char*)*param);
	if (strlen(allow_suffix) > strlen(deny_suffix)) {
		suffix_len = strlen(allow_suffix);
	} else {
		suffix_len = strlen(deny_suffix);
	}

	buffer = pkg_malloc(param_len + suffix_len + 1);
	if (!buffer) {
		LOG(L_ERR, "single_fixup(): No memory left\n");
		return -1;
	}

	strcpy(buffer, (char*)*param);
	strcat(buffer, allow_suffix);
	tmp = buffer; 
	ret = load_fixup(&tmp, 1);

	strcpy(buffer + param_len, deny_suffix);
	tmp = buffer;
	ret |= load_fixup(&tmp, 2);

	*param = tmp;

	pkg_free(buffer);
	return ret;
}


/*
 * Convert the name of the file into table index and pvar into parsed pseudo
 * variable specification
 */
static int double_fixup(void** param, int param_no)
{
	char* buffer;
	void* tmp;
	int param_len, ret, suffix_len;
	xl_spec_t *sp;

	if (param_no == 1) { /* basename */
	    param_len = strlen((char*)*param);
	    if (strlen(allow_suffix) > strlen(deny_suffix)) {
		suffix_len = strlen(allow_suffix);
	    } else {
		suffix_len = strlen(deny_suffix);
	    }

	    buffer = pkg_malloc(param_len + suffix_len + 1);
	    if (!buffer) {
		LOG(L_ERR, "permissions:double_fixup(): No memory left\n");
		return -1;
	    }
	    
	    strcpy(buffer, (char*)*param);
	    strcat(buffer, allow_suffix);
	    tmp = buffer; 
	    ret = load_fixup(&tmp, 1);
	    
	    strcpy(buffer + param_len, deny_suffix);
	    tmp = buffer;
	    ret |= load_fixup(&tmp, 2);
	    
	    *param = tmp;
	    
	    pkg_free(buffer);

	    return 0;

	} else if (param_no == 2) { /* pseudo variable */

	    sp = (xl_spec_t*)pkg_malloc(sizeof(xl_spec_t));
	    if (sp == 0) {
		LOG(L_ERR,"permissions:double_fixup(): no pkg memory left\n");
		return -1;
	    }

	    if (xl_parse_spec((char*)*param, sp, XL_THROW_ERROR|XL_DISABLE_MULTI|XL_DISABLE_COLORS) == 0) {
		LOG(L_ERR,"permissions:double_fixup(): parsing of "
		    "pseudo variable %s failed!\n", (char*)*param);
		pkg_free(sp);
		return -1;
	    }

	    if (sp->type == XL_NULL) {
		LOG(L_ERR,"permissions:double_fixup(): bad pseudo "
		    "variable\n");
		pkg_free(sp);
		return -1;
	    }

	    *param = (void*)sp;

	    return 0;
	}

	*param = (void *)0;

	return 0;
}


/*
 * Convert pvars into parsed pseudo variable specifications
 */
static int address_fixup(void** param, int param_no)
{
    xl_spec_t *sp;

    if ((param_no == 1) || (param_no == 2)) { /* pseudo variables */
	
	sp = (xl_spec_t*)pkg_malloc(sizeof(xl_spec_t));
	if (sp == 0) {
	    LOG(L_ERR,"permissions:single_pvar_fixup(): no pkg memory left\n");
	    return -1;
	}

	if (xl_parse_spec((char*)*param, sp, XL_THROW_ERROR|XL_DISABLE_MULTI|XL_DISABLE_COLORS) == 0) {
	    LOG(L_ERR,"permissions:single_pvar_fixup(): parsing of "
		"pseudo variable %s failed!\n", (char*)*param);
	    pkg_free(sp);
	    return -1;
	}

	if (sp->type == XL_NULL) {
	    LOG(L_ERR,"permissions:single_pvap_fixup(): bad pseudo "
		"variable\n");
	    pkg_free(sp);
	    return -1;
	}

	*param = (void*)sp;

	return 0;
    }

    *param = (void *)0;

    return 0;
}


/*
 * Convert int or pvar parameter into int_or_pvar struct
 */
static int int_or_pvar_fixup(void** param, int param_no)
{
    char *s;
    str str_param;
    int_or_pvar_t *res;

    if (param_no != 1) return 0;

    res = (int_or_pvar_t *)pkg_malloc(sizeof(int_or_pvar_t));
    if (res == 0) {
	LOG(L_ERR,"permissions:int_or_pvar_fixup(): "
	    "no pkg memory left for int_or_pvar_t\n");
	return -1;
    }
    
    s = (char *)*param;

    if (*s == '$') {  /* pvar */
	res->pvar = (xl_spec_t*)pkg_malloc(sizeof(xl_spec_t));
	if (res->pvar == 0) {
	    LOG(L_ERR,"permissions:int_or_pvar_fixup(): "
		"no pkg memory left for xl_spec_t\n");
	    pkg_free(res);
	    return -1;
	}

	if (xl_parse_spec(s, res->pvar,
			  XL_THROW_ERROR|XL_DISABLE_MULTI|XL_DISABLE_COLORS)
	    == 0) {
	    LOG(L_ERR,"permissions:int_or_pvar_fixup(): parsing of "
		"pseudo variable %s failed!\n", (char*)*param);
	    pkg_free(res->pvar);
	    pkg_free(res);
	    return -1;
	}

	if (res->pvar->type == XL_NULL) {
	    LOG(L_ERR,"permissions:int_or_pvap_fixup(): bad pseudo "
		"variable\n");
	    pkg_free(res->pvar);
	    pkg_free(res);
	    return -1;
	}

	*param = (void*)res;

	return 0;
    }

    /* int */
    str_param.s = s;
    str_param.len = strlen(s);
    if (str2int(&str_param, &(res->i)) == 1) {
	LOG(L_ERR, "permissions:int_or_pvar_fixup: bad integer <%s>\n", s);
	pkg_free(res);
	return -1;
    } else {
	res->pvar = (xl_spec_t *)0;
	*param = (void *)res;
	return 0;
    }
}


/*
 * module initialization function 
 */
static int mod_init(void)
{
	LOG(L_INFO, "permissions - initializing\n");

	allow[0].filename = get_pathname(DEFAULT_ALLOW_FILE);
	allow[0].rules = parse_config_file(allow[0].filename);
	if (allow[0].rules) {
		LOG(L_INFO, "Default allow file (%s) parsed\n", allow[0].filename);
	} else {
		LOG(L_WARN, "Default allow file (%s) not found => empty rule set\n",
			allow[0].filename);
	}

	deny[0].filename = get_pathname(DEFAULT_DENY_FILE);
	deny[0].rules = parse_config_file(deny[0].filename);
	if (deny[0].rules) {
		LOG(L_INFO, "Default deny file (%s) parsed\n", deny[0].filename);
	} else {
		LOG(L_WARN, "Default deny file (%s) not found => empty rule set\n",
			deny[0].filename);
	}

	if (init_trusted() != 0) {
		LOG(L_ERR, "Error while initializing allow_trusted function\n");
		return -1;
	}

	if (init_tag_avp( tag_avp_param) < 0) {
		LOG(L_ERR,"ERROR:permissions:mod_init: failed to process tag AVP\n");
		return -1;
	}

	if (init_addresses() != 0) {
		LOG(L_ERR, "Error while initializing allow_address function\n");
		return -1;
	}

	rules_num = 1;
	return 0;
}


static int child_init(int rank)
{
	if (init_child_trusted(rank) == -1)
		return -1;
	return 0;
}


static int mi_trusted_child_init()
{
    return mi_init_trusted();
}


static int mi_addr_child_init()
{
    return mi_init_addresses();
}


/* 
 * destroy function 
 */
static void mod_exit(void) 
{
	int i;

	for(i = 0; i < rules_num; i++) {
		free_rule(allow[i].rules);
		pkg_free(allow[i].filename);

		free_rule(deny[i].rules);
		pkg_free(deny[i].filename);
	}

	clean_trusted();

	clean_addresses();
}


/*
 * Uses default rule files from the module parameters
 */
int allow_routing_0(struct sip_msg* msg, char* str1, char* str2)
{
	return check_routing(msg, 0);
}


int allow_routing_1(struct sip_msg* msg, char* basename, char* s)
{
	return check_routing(msg, (int)(long)basename);
}


/*
 * Accepts allow and deny files as parameters
 */
int allow_routing_2(struct sip_msg* msg, char* allow_file, char* deny_file)
{
	     /* Index converted by load_lookup */
	return check_routing(msg, (int)(long)allow_file);
}


/*
 * Test of REGISTER messages. Creates To-Contact pairs and compares them
 * against rules in allow and deny files passed as parameters. The function
 * iterates over all Contacts and creates a pair with To for each contact 
 * found. That allows to restrict what IPs may be used in registrations, for
 * example
 */
static int check_register(struct sip_msg* msg, int idx)
{
	int len;
	static char to_str[EXPRESSION_LENGTH + 1];
	char* contact_str;
	contact_t* c;

	     /* turn off control, allow any routing */
	if ((!allow[idx].rules) && (!deny[idx].rules)) {
		DBG("check_register(): No rules => allow any registration\n");
		return 1;
	}

	     /*
	      * Note: We do not parse the whole header field here although the message can
	      * contain multiple Contact header fields. We try contacts one by one and if one
	      * of them causes reject then we don't look at others, this could improve performance
	      * a little bit in some situations
	      */
	if (parse_headers(msg, HDR_TO_F | HDR_CONTACT_F, 0) == -1) {
		LOG(L_ERR, "check_register(): Error while parsing headers\n");
		return -1;
	}

	if (!msg->to) {
		LOG(L_ERR, "check_register(): To or Contact not found\n");
		return -1;
	}
	
	if (!msg->contact) {
		     /* REGISTER messages that contain no Contact header field
		      * are allowed. Such messages do not modify the contents of
		      * the user location database anyway and thus are not harmful
		      */
		DBG("check_register(): No Contact found, allowing\n");
		return 1;
	}

	     /* Check if the REGISTER message contains start Contact and if
	      * so then allow it
	      */
	if (parse_contact(msg->contact) < 0) {
		LOG(L_ERR, "check_register(): Error while parsing Contact HF\n");
		return -1;
	}

	if (((contact_body_t*)msg->contact->parsed)->star) {
		DBG("check_register(): * Contact found, allowing\n");
		return 1;
	}

	len = ((struct to_body*)msg->to->parsed)->uri.len;
	if (len > EXPRESSION_LENGTH) {
                LOG(L_ERR, "check_register(): To header field is too long: %d chars\n", len);
                return -1;
	}
	strncpy(to_str, ((struct to_body*)msg->to->parsed)->uri.s, len);
	to_str[len] = '\0';

	if (contact_iterator(&c, msg, 0) < 0) {
		return -1;
	}

	while(c) {
		contact_str = get_plain_uri(&c->uri);
		if (!contact_str) {
			LOG(L_ERR, "check_register(): Can't extract plain Contact URI\n");
			return -1;
		}

		DBG("check_register(): Looking for To: %s Contact: %s\n", to_str, contact_str);

		     /* rule exists in allow file */
		if (search_rule(allow[idx].rules, to_str, contact_str)) {
			if (check_all_branches) goto skip_deny;
		}
	
		     /* rule exists in deny file */
		if (search_rule(deny[idx].rules, to_str, contact_str)) {
			DBG("check_register(): Deny rule found => Register denied\n");
			return -1;
		}

	skip_deny:
		if (contact_iterator(&c, msg, c) < 0) {
			return -1;
		}
	}

	DBG("check_register(): No contact denied => Allowed\n");
	return 1;
}


int allow_register_1(struct sip_msg* msg, char* basename, char* s)
{
	return check_register(msg, (int)(long)basename);
}


int allow_register_2(struct sip_msg* msg, char* allow_file, char* deny_file)
{
	return check_register(msg, (int)(long)allow_file);
}


/*
 * determines the permission to an uri
 * return values:
 * -1:	deny
 * 1:	allow
 */
static int allow_uri(struct sip_msg* msg, char* _idx, char* _sp) 
{
	struct hdr_field *from;
	int idx, len;
	static char from_str[EXPRESSION_LENGTH+1];
	static char uri_str[EXPRESSION_LENGTH+1];
	xl_spec_t *sp;
	xl_value_t xl_val;

	idx = (int)(long)_idx;
	sp = (xl_spec_t *)_sp;
	
	/* turn off control, allow any uri */
	if ((!allow[idx].rules) && (!deny[idx].rules)) {
		DBG("allow_uri(): No rules => allow any uri\n");
		return 1;
	}
	
	/* looking for FROM HF */
        if ((!msg->from) && (parse_headers(msg, HDR_FROM_F, 0) == -1)) {
                LOG(L_ERR, "allow_uri(): Error while parsing message\n");
                return -1;
        }
	
	if (!msg->from) {
		LOG(L_ERR, "allow_uri(): FROM header field not found\n");
		return -1;
	}
	
	/* we must call parse_from_header explicitly */
        if ((!(msg->from)->parsed) && (parse_from_header(msg) < 0)) {
                LOG(L_ERR, "allow_uri(): Error while parsing From body\n");
                return -1;
        }
	
	from = msg->from;
	len = ((struct to_body*)from->parsed)->uri.len;
	if (len > EXPRESSION_LENGTH) {
                LOG(L_ERR, "allow_uri(): From header field is too long: "
		    "%d chars\n", len);
                return -1;
	}
	strncpy(from_str, ((struct to_body*)from->parsed)->uri.s, len);
	from_str[len] = '\0';

	if (sp && (xl_get_spec_value(msg, sp, &xl_val, 0) == 0)) {
	    if (xl_val.flags & XL_VAL_STR) {
		if (xl_val.rs.len > EXPRESSION_LENGTH) {
		    LOG(L_ERR, "allow_uri(): pseudo variable value is too "
			"long: %d chars\n", xl_val.rs.len);
		    return -1;
		}
		strncpy(uri_str, xl_val.rs.s, xl_val.rs.len);
		uri_str[xl_val.rs.len] = '\0';
	    } else {
		LOG(L_ERR, "allow_uri(): pseudo variable value is not "
		    "string\n");
		return -1;
	    }
	} else {
	    LOG(L_ERR, "allow_uri(): cannot get pseudo variable value\n");
	    return -1;
	}

        DBG("allow_uri(): looking for From: %s URI: %s\n", from_str, uri_str);
	     /* rule exists in allow file */
	if (search_rule(allow[idx].rules, from_str, uri_str)) {
    		DBG("allow_uri(): allow rule found => URI is allowed\n");
		return 1;
	}
	
	/* rule exists in deny file */
	if (search_rule(deny[idx].rules, from_str, uri_str)) {
	    DBG("allow_uri(): deny rule found => URI is denied\n");
	    return -1;
	}

	DBG("allow_uri(): Neither allow nor deny rule found => URI is allowed\n");

	return 1;
}