/*
  * $Id$
  *
  * Copyright (C) 2007 1&1 Internet AG
  *

  * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 

 /*!
  * \file
  * \brief USERBLACKLIST :: module definitions
  * \ingroup userblacklist
  * - Module: \ref userblacklist
  */
 
 /*!
  * \defgroup userblacklist USERBLACKLIST :: The Kamailio userblacklist Module
  *
  * The userblacklist module allows Kamailio to handle blacklists on a per user basis.
  * This information is stored in a database table, which is queried to decide if the
  * number (more exactly, the request URI user) is blacklisted or not.
  * An additional functionality that this module provides is the ability to handle
  * global blacklists. This lists are loaded on startup into memory, thus providing a
  * better performance then in the userblacklist case.
  */

 
 #include <string.h>
 
 #include "../../parser/parse_uri.h"
 #include "../../mem/shm_mem.h"
 #include "../../sr_module.h"

 #include "../../lib/kmi/mi.h"

 #include "../../mem/mem.h"
 #include "../../usr_avp.h"
 #include "../../locking.h"
 #include "../../error.h"
 #include "../../ut.h"
 #include "../../mod_fix.h"
 

 #include "../../lib/trie/dtrie.h"

 #include "db.h"

 #include "db_userblacklist.h"

 
 MODULE_VERSION
 
 
 #define MAXNUMBERLEN 31
 
 
 typedef struct _avp_check
 {
 	int avp_flags;
 	int_str avp_name;
 } avp_check_t;
 
 
 struct check_blacklist_fs_t {

   struct dtrie_node_t *dtrie_root;

 };
 

 str userblacklist_db_url = str_init(DEFAULT_RODB_URL);

 static int use_domain   = 0;
 
 /* ---- fixup functions: */
 static int check_blacklist_fixup(void** param, int param_no);
 static int check_user_blacklist_fixup(void** param, int param_no);
 
 /* ---- exported commands: */

 static int check_user_blacklist(struct sip_msg *msg, char* str1, char* str2, char* str3, char* str4);

 static int check_user_whitelist(struct sip_msg *msg, char* str1, char* str2, char* str3, char* str4);

 static int check_blacklist(struct sip_msg *msg, struct check_blacklist_fs_t *arg1);

 
 /* ---- module init functions: */
 static int mod_init(void);
 static int child_init(int rank);
 static int mi_child_init(void);
 static void mod_destroy(void);
 
 /* --- fifo functions */

 struct mi_root * mi_reload_blacklist(struct mi_root* cmd, void* param);  /* usage: kamctl fifo reload_blacklist */

 
 
 static cmd_export_t cmds[]={
 	{ "check_user_blacklist", (cmd_function)check_user_blacklist, 2, check_user_blacklist_fixup, 0, REQUEST_ROUTE | FAILURE_ROUTE },

 	{ "check_user_whitelist", (cmd_function)check_user_whitelist, 2, check_user_blacklist_fixup, 0, REQUEST_ROUTE | FAILURE_ROUTE },

 	{ "check_user_blacklist", (cmd_function)check_user_blacklist, 3, check_user_blacklist_fixup, 0, REQUEST_ROUTE | FAILURE_ROUTE },

 	{ "check_user_whitelist", (cmd_function)check_user_whitelist, 3, check_user_blacklist_fixup, 0, REQUEST_ROUTE | FAILURE_ROUTE },

 	{ "check_user_blacklist", (cmd_function)check_user_blacklist, 4, check_user_blacklist_fixup, 0, REQUEST_ROUTE | FAILURE_ROUTE },

 	{ "check_user_whitelist", (cmd_function)check_user_whitelist, 4, check_user_blacklist_fixup, 0, REQUEST_ROUTE | FAILURE_ROUTE },

 	{ "check_blacklist", (cmd_function)check_blacklist, 1, check_blacklist_fixup, 0, REQUEST_ROUTE | FAILURE_ROUTE },
 	{ 0, 0, 0, 0, 0, 0}
 };
 
 
 static param_export_t params[] = {

 	userblacklist_DB_URL
 	userblacklist_DB_TABLE
 	globalblacklist_DB_TABLE
 	userblacklist_DB_COLS
 	globalblacklist_DB_COLS

 	{ "use_domain",      INT_PARAM, &use_domain },
 	{ 0, 0, 0}
 };
 
 
 /* Exported MI functions */
 static mi_export_t mi_cmds[] = {
 	{ "reload_blacklist", mi_reload_blacklist, MI_NO_INPUT_FLAG, 0, mi_child_init },
 	{ 0, 0, 0, 0, 0}
 };
 
 
 struct module_exports exports= {
 	"userblacklist",

 	DEFAULT_DLFLAGS,

 	cmds,
 	params,
 	0,
 	mi_cmds,
 	0,

 	0,
 	mod_init,

 	0,
 	mod_destroy,
 	child_init
 };
 
 
 struct source_t {
 	struct source_t *next;
 	/** prefixes to be used are stored in this table */
 	char *table;
 	/** d-tree structure: will be built from data in database */

 	struct dtrie_node_t *dtrie_root;

 };
 
 
 struct source_list_t {
   struct source_t *head;
 };
 
 
 static gen_lock_t *lock = NULL;
 static struct source_list_t *sources = NULL;

 static struct dtrie_node_t *dtrie_root;

 
 
 static int check_user_blacklist_fixup(void** param, int param_no)
 {
 	pv_elem_t *model=NULL;
 	str s;
 
 	/* convert to str */
 	s.s = (char*)*param;
 	s.len = strlen(s.s);
 

 	if (param_no > 0 && param_no <= 4) {
 		if(s.len == 0 && param_no != 4) {
 			LM_ERR("no parameter %d\n", param_no);

 			return E_UNSPEC;
 		}
 
 		if(pv_parse_format(&s, &model) < 0 || !model) {

 			LM_ERR("wrong format [%.*s] for parameter %d\n", s.len, s.s, param_no);

 			return E_UNSPEC;
 		}

 		if(!model->spec.getf) {
 			if(param_no == 1) {

 				if(str2int(&s, (unsigned int*)&model->spec.pvp.pvn.u.isname.name.n) != 0) {
 					LM_ERR("wrong value [%.*s] for parameter %d\n", s.len, s.s, param_no);

 					return E_UNSPEC;

 				}
 			} else {
 				if(param_no == 2 || param_no == 3) {
 					LM_ERR("wrong value [%.*s] for parameter %d\n", s.len, s.s, param_no);
 					return E_UNSPEC;
 				} else {
 					// only a string
 					return 0;
 				}

 			}
 		}
 		*param = (void*)model;

 	} else {
 		LM_ERR("wrong number of parameters\n");

 	}
 
 	return 0;
 }
 
 

 static int check_user_list(struct sip_msg *msg, char* str1, char* str2, char* str3, char* str4, int listtype)

 {
 	str user = { .len = 0, .s = NULL };
 	str domain = { .len = 0, .s = NULL};

 	str table = { .len = 0, .s = NULL};
 	str number = { .len = 0, .s = NULL};
 

 	void **nodeflags;

 	char *ptr;

 	char req_number[MAXNUMBERLEN+1];
 

 	/* user */

 	if(((pv_elem_p)str1)->spec.getf) {
 		if(pv_printf_s(msg, (pv_elem_p)str1, &user) != 0) {
 			LM_ERR("cannot print user pseudo-variable\n");
 			return -1;
 		}
 	}

 	/* domain */
 	if(((pv_elem_p)str2)->spec.getf) {

 		if(pv_printf_s(msg, (pv_elem_p)str2, &domain) != 0) {
 			LM_ERR("cannot print domain pseudo-variable\n");
 			return -1;
 		}
 	}

 	/* source number */
 	if(str3 != NULL && ((pv_elem_p)str3)->spec.getf) {
 		if(pv_printf_s(msg, (pv_elem_p)str3, &number) != 0) {
 			LM_ERR("cannot print number pseudo-variable\n");
 			return -1;
 		}
 	}
 	/* table name */
 	if(str4 != NULL && strlen(str4) > 0) {
 		/* string */
 		table.s=str4;
 		table.len=strlen(str4);
 	} else {
 		/* use default table name */

 		table.len=userblacklist_table.len;
 		table.s=userblacklist_table.s;

 	}
 

 	if (msg->first_line.type != SIP_REQUEST) {
 		LM_ERR("SIP msg is not a request\n");
 		return -1;
 	}

 
 	if(number.s == NULL) {
 		/* use R-URI */
 		if ((parse_sip_msg_uri(msg) < 0) || (!msg->parsed_uri.user.s) || (msg->parsed_uri.user.len > MAXNUMBERLEN)) {
 			LM_ERR("cannot parse msg URI\n");
 			return -1;
 		}
 		strncpy(req_number, msg->parsed_uri.user.s, msg->parsed_uri.user.len);
 		req_number[msg->parsed_uri.user.len] = '\0';
 	} else {
 		if (number.len > MAXNUMBERLEN) {
 			LM_ERR("number to long\n");
 			return -1;
 		}
 		strncpy(req_number, number.s, number.len);
 		req_number[number.len] = '\0';

 	}
 

 	LM_DBG("check entry %s for user %.*s on domain %.*s in table %.*s\n", req_number,
 		user.len, user.s, domain.len, domain.s, table.len, table.s);

 	if (db_build_userbl_tree(&user, &domain, &table, dtrie_root, use_domain) < 0) {

 		LM_ERR("cannot build d-tree\n");
 		return -1;
 	}
 

 	ptr = req_number;
 	/* Skip over non-digits.  */
 	while (strlen(ptr) > 0 && !isdigit(*ptr)) {
 		ptr = ptr + 1;
 	}
 

 	nodeflags = dtrie_longest_match(dtrie_root, ptr, strlen(ptr), NULL, 10);

 	if (nodeflags) {
 		if (*nodeflags == (void *)MARK_WHITELIST) {

 			/* LM_ERR("whitelisted"); */
 			return 1; /* found, but is whitelisted */
 		}

 	} else {

 		if(!listtype) {
 			/* LM_ERR("not found return 1"); */
 			return 1; /* not found is ok */
 		} else {
 			/* LM_ERR("not found return -1"); */
 			return -1; /* not found is not ok */
 		}

 	}
 	LM_DBG("entry %s is blacklisted\n", req_number);
 	return -1;
 }
 
 

 static int check_user_whitelist(struct sip_msg *msg, char* str1, char* str2, char* str3, char* str4)
 {
 	return check_user_list(msg, str1, str2, str3, str4, 1);
 }
 
 
 static int check_user_blacklist(struct sip_msg *msg, char* str1, char* str2, char* str3, char* str4)
 {
 	return check_user_list(msg, str1, str2, str3, str4, 0);
 }
 
 
 

 /**
  * Finds d-tree root for given table.
  * \return pointer to d-tree root on success, NULL otherwise
  */

 static struct dtrie_node_t *table2dt(const char *table)

 {
 	struct source_t *src = sources->head;
 	while (src) {

 		if (strcmp(table, src->table) == 0) return src->dtrie_root;

 		src = src->next;
 	}
 
 	LM_ERR("invalid table '%s'.\n", table);
 	return NULL;
 }
 
 
 /**
  * Adds a new table to the list, if the table is
  * already present, nothing will be done.
  * \return zero on success, negative on errors
  */
 static int add_source(const char *table)
 {
 	/* check if the table is already present */
 	struct source_t *src = sources->head;
 	while (src) {
 		if (strcmp(table, src->table) == 0) return 0;
 		src = src->next;
 	}
 
 	src = shm_malloc(sizeof(struct source_t));
 	if (!src) {

 		SHM_MEM_ERROR;

 		return -1;
 	}
 	memset(src, 0, sizeof(struct source_t));
 
 	src->next = sources->head;
 	sources->head = src;
 
 	src->table = shm_malloc(strlen(table)+1);
 	if (!src->table) {

 		SHM_MEM_ERROR;

 		shm_free(src);
 		return -1;
 	}
 	strcpy(src->table, table);
 	LM_DBG("add table %s", table);
 

 	src->dtrie_root = dtrie_init(10);
 

 	if (src->dtrie_root == NULL) {
 		LM_ERR("could not initialize data");
 		return -1;
 	}
 
 	return 0;

 }
 
 
 static int check_blacklist_fixup(void **arg, int arg_no)
 {
 	char *table = (char *)(*arg);

 	struct dtrie_node_t *node = NULL;

 	struct check_blacklist_fs_t *new_arg;
 	

 	if (arg_no != 1) {

 		LM_ERR("wrong number of parameters\n");

 		return -1;
 	}
 
 	if (!table) {

 		LM_ERR("no table name\n");

 		return -1;
 	}
 	/* try to add the table */
 	if (add_source(table) != 0) {
 		LM_ERR("could not add table");
 		return -1;
 	}	
 
 	/* get the node that belongs to the table */
 	node = table2dt(table);
 	if (!node) {

 		LM_ERR("invalid table '%s'\n", table);

 		return -1;
 	}
 

 	new_arg = pkg_malloc(sizeof(struct check_blacklist_fs_t));

 	if (!new_arg) {

 		PKG_MEM_ERROR;

 		return -1;
 	}
 	memset(new_arg, 0, sizeof(struct check_blacklist_fs_t));

 	new_arg->dtrie_root = node;

 	*arg=(void*)new_arg;
 
 	return 0;
 }
 
 

 static int check_blacklist(struct sip_msg *msg, struct check_blacklist_fs_t *arg1)

 {

 	void **nodeflags;

 	char *ptr;

 	char req_number[MAXNUMBERLEN+1];

 	int ret = -1;

 
 	if (msg->first_line.type != SIP_REQUEST) {
 		LM_ERR("SIP msg is not a request\n");
 		return -1;
 	}
 
 	if (parse_sip_msg_uri(msg) < 0) {
 		LM_ERR("cannot parse msg URI\n");
 		return -1;
 	}
 
 	if ((parse_sip_msg_uri(msg) < 0) || (!msg->parsed_uri.user.s) || (msg->parsed_uri.user.len > MAXNUMBERLEN)) {
 		LM_ERR("cannot parse msg URI\n");
 		return -1;
 	}
 	strncpy(req_number, msg->parsed_uri.user.s, msg->parsed_uri.user.len);
 	req_number[msg->parsed_uri.user.len] = '\0';
 

 	ptr = req_number;
 	/* Skip over non-digits.  */
 	while (strlen(ptr) > 0 && !isdigit(*ptr)) {
 		ptr = ptr + 1;
 	}
 

 	LM_DBG("check entry %s\n", req_number);

 
 	/* avoids dirty reads when updating d-tree */
 	lock_get(lock);

 	nodeflags = dtrie_longest_match(arg1->dtrie_root, ptr, strlen(ptr), NULL, 10);

 	if (nodeflags) {
 		if (*nodeflags == (void *)MARK_WHITELIST) {

 			/* LM_DBG("whitelisted"); */

 			ret = 1; /* found, but is whitelisted */

 		}
 	}
 	else {
 		/* LM_ERR("not found"); */

 		ret = 1; /* not found is ok */

 	}

 	lock_release(lock);

 
 	LM_DBG("entry %s is blacklisted\n", req_number);

 	return ret;

 }
 
 
 /**
  * Fills the d-tree for all configured and prepared sources.
  * \return 0 on success, -1 otherwise
  */
 static int reload_sources(void)
 {
 	int result = 0;
 	str tmp;

 	struct source_t *src;
 	int n;

 
 	/* critical section start: avoids dirty reads when updating d-tree */
 	lock_get(lock);
 

 	src = sources->head;

 	while (src) {
 		tmp.s = src->table;
 		tmp.len = strlen(src->table);

 		n = db_reload_source(&tmp, src->dtrie_root);

 		if (n < 0) {

 			LM_ERR("cannot reload source from '%.*s'\n", tmp.len, tmp.s);

 			result = -1;
 			break;
 		}

 		LM_INFO("got %d entries from '%.*s'\n", n, tmp.len, tmp.s);

 		src = src->next;
 	}
 
 	/* critical section end */
 	lock_release(lock);
 
 	return result;
 }
 
 
 static int init_source_list(void)
 {
 	sources = shm_malloc(sizeof(struct source_list_t));
 	if (!sources) {

 		SHM_MEM_ERROR;

 		return -1;
 	}
 	sources->head = NULL;
 	return 0;
 }
 
 
 static void destroy_source_list(void)
 {
 	if (sources) {
 		while (sources->head) {
 			struct source_t *src = sources->head;
 			sources->head = src->next;
 
 			if (src->table) shm_free(src->table);

 			dtrie_destroy(&(src->dtrie_root), NULL, 10);

 			shm_free(src);
 		}
 
 		shm_free(sources);
 		sources = NULL;
 	}
 }
 
 
 static int init_shmlock(void)
 {
 	lock = lock_alloc();
 	if (!lock) {
 		LM_CRIT("cannot allocate memory for lock.\n");
 		return -1;
 	}
 	if (lock_init(lock) == 0) {
 		LM_CRIT("cannot initialize lock.\n");
 		return -1;
 	}
 
 	return 0;
 }
 
 
 static void destroy_shmlock(void)
 {
 	if (lock) {
 		lock_destroy(lock);
 		lock_dealloc((void *)lock);
 		lock = NULL;
 	}
 }
 
 
 struct mi_root * mi_reload_blacklist(struct mi_root* cmd, void* param)
 {
 	struct mi_root * tmp = NULL;
 	if(reload_sources() == 0) {

 		tmp = init_mi_tree( 200, MI_OK_S, MI_OK_LEN);

 	} else {
 		tmp = init_mi_tree( 500, "cannot reload blacklist", 21);
 	}
 
 	return tmp;
 }
 
 
 static int mod_init(void)
 {

 	if(register_mi_mod(exports.name, mi_cmds)!=0)
 	{
 		LM_ERR("failed to register MI commands\n");
 		return -1;
 	}
 

 	userblacklist_db_vars();

 	if (userblacklist_db_init() != 0) return -1;

 	if (init_shmlock() != 0) return -1;
 	if (init_source_list() != 0) return -1;
 	return 0;
 }
 
 
 static int child_init(int rank)
 {

 	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
 		return 0; /* do nothing for the main process */
 

 	if (userblacklist_db_open() != 0) return -1;

 	dtrie_root=dtrie_init(10);

 	if (dtrie_root == NULL) {
 		LM_ERR("could not initialize data");
 		return -1;
 	}

 	/* because we've added new sources during the fixup */
 	if (reload_sources() != 0) return -1;
 
 	return 0;
 }
 
 
 static int mi_child_init(void)
 {

 	if (userblacklist_db_open() != 0) return -1;

 	dtrie_root=dtrie_init(10);

 	if (dtrie_root == NULL) {
 		LM_ERR("could not initialize data");
 		return -1;
 	}

 	/* because we've added new sources during the fixup */
 	if (reload_sources() != 0) return -1;
 
 	return 0;
 }
 
 
 static void mod_destroy(void)
 {
 	destroy_source_list();
 	destroy_shmlock();

 	userblacklist_db_close();

 	dtrie_destroy(&dtrie_root, NULL, 10);

 }