kamailio/sr_module.h

/* $Id$
 *
 * modules/plug-in structures declarations
 *
 *
 * Copyright (C) 2001-2003 FhG Fokus
 *
 * This file is part of ser, a free SIP server.
 *
 * ser 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
 *
 * For a license to use the ser software under conditions
 * other than those described here, or to purchase support for this
 * software, please contact iptel.org by e-mail at the following addresses:
 *    [email protected]
 *
 * ser 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
 */
/*
 * History:
 * --------
 *  2003-03-10  changed module exports interface: added struct cmd_export
 *               and param_export (andrei)
 *  2003-03-16  Added flags field to cmd_export_ (janakj)
 *  2003-04-05  s/reply_route/failure_route, onreply_route introduced (jiri)
 *  2004-03-12  extra flag USE_FUNC_PARAM added to modparam type -
 *              instead of copying the param value, a func is called (bogdan)
 *  2004-09-19  switched to version.h for the module versions checks (andrei)
 *  2004-12-03  changed param_func_t to (modparam_t, void*), killed
 *               param_func_param_t   (andrei)
 *  2007-06-07  added PROC_INIT, called in the main process context
 *               (same as PROC_MAIN), buf guaranteed to be called before
 *               any other process is forked (andrei)
 */


#ifndef sr_module_h
#define sr_module_h

#include "parser/msg_parser.h" /* for sip_msg */
#include "version.h"
#include "rpc.h"
#include "route_struct.h"
#include "str.h"

typedef  struct module_exports* (*module_register)();
typedef  int (*cmd_function)(struct sip_msg*, char*, char*);
typedef  int (*fixup_function)(void** param, int param_no);
typedef  int (*response_function)(struct sip_msg*);
typedef  void (*onbreak_function)(struct sip_msg*);
typedef void (*destroy_function)();
typedef int (*init_function)(void);
typedef int (*child_init_function)(int rank);


#define PARAM_STRING     (1U<<0)  /* String (char *) parameter type */
#define PARAM_INT        (1U<<1)  /* Integer parameter type */
#define PARAM_STR        (1U<<2)  /* struct str parameter type */
#define PARAM_USE_FUNC   (1U<<(8*sizeof(int)-1))
#define PARAM_TYPE_MASK(_x)   ((_x)&(~PARAM_USE_FUNC))

/* temporary, for backward compatibility only until all modules adjust it */
#define STR_PARAM PARAM_STRING
#define INT_PARAM PARAM_INT
#define USE_FUNC_PARAM PARAM_USE_FUNC

typedef unsigned int modparam_t;

typedef int (*param_func_t)( modparam_t type, void* val);

#define REQUEST_ROUTE 1  /* Function can be used in request route blocks */
#define FAILURE_ROUTE 2  /* Function can be used in reply route blocks */
#define ONREPLY_ROUTE 4  /* Function can be used in on_reply */
#define BRANCH_ROUTE  8  /* Function can be used in branch_route blocks */
#define ONSEND_ROUTE   16  /* Function can be used in onsend_route blocks */

/* Macros - used as rank in child_init function */
#define PROC_MAIN      0  /* Main ser process */
#define PROC_TIMER    -1  /* Timer attendant process */
#define PROC_RPC      -2  /* RPC type process */
#define PROC_FIFO      PROC_RPC  /* FIFO attendant process */
#define PROC_TCP_MAIN -4  /* TCP main process */
#define PROC_UNIXSOCK -5  /* Unix socket server */
#define PROC_ATTENDANT -10  /* main "attendant process */
#define PROC_INIT     -127 /* special rank, the context is the main ser
							  process, but this is guaranteed to be executed
							  before any process is forked, so it can be used
							  to setup shared variables that depend on some
							  after mod_init available information (e.g.
							  total number of processes).
							 WARNING: child_init(PROC_MAIN) is again called
							 in the same process (main), but latter 
							 (before tcp), so make sure you don't init things 
							 twice, bot in PROC_MAIN and PROC_INT */
#define PROC_NOCHLDINIT -128 /* no child init functions will be called
                                if this rank is used in fork_process() */

#define PROC_MIN PROC_NOCHLDINIT /* Minimum process rank */

#define MODULE_VERSION \
	char *module_version=SER_FULL_VERSION; \
	char *module_flags=SER_COMPILE_FLAGS;

struct cmd_export_ {
	char* name;             /* null terminated command name */
	cmd_function function;  /* pointer to the corresponding function */
	int param_no;           /* number of parameters used by the function */
	fixup_function fixup;   /* pointer to the function called to "fix" the
							   parameters */
	int flags;              /* Function flags */
};


struct param_export_ {
	char* name;             /* null terminated param. name */
	modparam_t type;        /* param. type */
	void* param_pointer;    /* pointer to the param. memory location */
};


enum {
	FPARAM_UNSPEC = 0,
	FPARAM_STRING = (1 << 0),
	FPARAM_STR    = (1 << 1),
	FPARAM_INT    = (1 << 2),
	FPARAM_REGEX  = (1 << 3),
	FPARAM_AVP    = (1 << 5),
	FPARAM_SELECT = (1 << 6),
	FPARAM_SUBST  = (1 << 7)
};

/*
 * Function parameter
 */
typedef struct fparam {
        char* orig;                       /* The original value */
        int type;                         /* Type of parameter */
        union {
		char* asciiz;             /* Zero terminated ASCII string */
		struct _str str;          /* pointer/len string */
		int i;                    /* Integer value */
		regex_t* regex;           /* Compiled regular expression */
		avp_ident_t avp;          /* AVP identifier */
	        select_t* select;         /* select structure */ 
	        struct subst_expr* subst; /* Regex substitution */
	} v;
} fparam_t;


typedef struct cmd_export_ cmd_export_t;
typedef struct param_export_ param_export_t;

struct module_exports {
	char* name;                     /* null terminated module name */

	cmd_export_t* cmds;             /* null terminated array of the exported
									   commands */
	rpc_export_t* rpc_methods;      /* null terminated array of exported rpc methods */
	param_export_t* params;         /* null terminated array of the exported
									   module parameters */

	init_function init_f;           /* Initialization function */
	response_function response_f;   /* function used for responses,
									   returns yes or no; can be null */
	destroy_function destroy_f;     /* function called when the module should
									   be "destroyed", e.g: on ser exit;
									   can be null */
	onbreak_function onbreak_f;
	child_init_function init_child_f;  /* function called by all processes
										  after the fork */
};


struct sr_module{
	char* path;
	void* handle;
	struct module_exports* exports;
	struct sr_module* next;
};


extern struct sr_module* modules; /* global module list*/
extern response_function* mod_response_cbks;/* response callback array */
extern int mod_response_cbk_no;    /* size of reponse callbacks array */

int register_builtin_modules();
int register_module(struct module_exports*, char*,  void*);
int load_module(char* path);
cmd_export_t* find_export_record(char* name, int param_no, int flags);
cmd_function find_export(char* name, int param_no, int flags);
cmd_function find_mod_export(char* mod, char* name, int param_no, int flags);
rpc_export_t* find_rpc_export(char* name, int flags);
void destroy_modules();
int init_child(int rank);
int init_modules(void);
struct sr_module* find_module_by_name(char* mod);

/*
 * Find a parameter with given type and return it's
 * address in memory
 * If there is no such parameter, NULL is returned
 */
void* find_param_export(struct sr_module* mod, char* name, modparam_t type_mask, modparam_t *param_type);

/* modules function prototypes:
 * struct module_exports* mod_register(); (type module_register)
 * int   foo_cmd(struct sip_msg* msg, char* param);
 *  - returns >0 if ok , <0 on error, 0 to stop processing (==DROP)
 * int   response_f(struct sip_msg* msg)
 *  - returns >0 if ok, 0 to drop message
 */


/* API function to get other parameters from fixup */
action_u_t *fixup_get_param(void **cur_param, int cur_param_no, int required_param_no);
int fixup_get_param_count(void **cur_param, int cur_param_no);

int fix_flag( modparam_t type, void* val,
					char* mod_name, char* param_name, int* flag);


/*
 * Common function parameter fixups
 */

/*
 * Generic parameter fixup function which creates
 * fparam_t structure. type parameter contains allowed
 * parameter types
 */
int fix_param(int type, void** param);

/*
 * Fixup variable string, the parameter can be
 * AVP, SELECT, or ordinary string. AVP and select
 * identifiers will be resolved to their values during
 * runtime
 *
 * The parameter value will be converted to fparam structure
 * This function returns -1 on an error
 */
int fixup_var_str_12(void** param, int param_no);

/* Same as fixup_var_str_12 but applies to the 1st parameter only */
int fixup_var_str_1(void** param, int param_no);

/* Same as fixup_var_str_12 but applies to the 2nd parameter only */
int fixup_var_str_2(void** param, int param_no);

/*
 * Fixup variable integer, the parameter can be
 * AVP, SELECT, or ordinary integer. AVP and select
 * identifiers will be resolved to their values and 
 * converted to int if necessary during runtime
 *
 * The parameter value will be converted to fparam structure
 * This function returns -1 on an error
 */
int fixup_var_int_12(void** param, int param_no);

/* Same as fixup_var_int_12 but applies to the 1st parameter only */
int fixup_var_int_1(void** param, int param_no);

/* Same as fixup_var_int_12 but applies to the 2nd parameter only */
int fixup_var_int_2(void** param, int param_no);

/*
 * The parameter must be a regular expression which must compile, the
 * parameter will be converted to compiled regex
 */
int fixup_regex_12(void** param, int param_no);

/* Same as fixup_regex_12 but applies to the 1st parameter only */
int fixup_regex_1(void** param, int param_no);

/* Same as fixup_regex_12 but applies to the 2nd parameter only */
int fixup_regex_2(void** param, int param_no);

/*
 * The string parameter will be converted to integer
 */
int fixup_int_12(void** param, int param_no);

/* Same as fixup_int_12 but applies to the 1st parameter only */
int fixup_int_1(void** param, int param_no);

/* Same as fixup_int_12 but applies to the 2nd parameter only */
int fixup_int_2(void** param, int param_no);

/*
 * Parse the parameter as static string, do not resolve
 * AVPs or selects, convert the parameter to str structure
 */
int fixup_str_12(void** param, int param_no);

/* Same as fixup_str_12 but applies to the 1st parameter only */
int fixup_str_1(void** param, int param_no);

/* Same as fixup_str_12 but applies to the 2nd parameter only */
int fixup_str_2(void** param, int param_no);

/*
 * Get the function parameter value as string
 * Return values:  0 - Success
 *                -1 - Cannot get value
 */
int get_str_fparam(str* dst, struct sip_msg* msg, fparam_t* param);

/*
 * Get the function parameter value as integer
 * Return values:  0 - Success
 *                -1 - Cannot get value
 */
int get_int_fparam(int* dst, struct sip_msg* msg, fparam_t* param);


/**
 * Retrieve the compiled RegExp.
 * @return: 0 for success, negative on error.
 */
int get_regex_fparam(regex_t *dst, struct sip_msg* msg, fparam_t* param);
#endif /* sr_module_h */