[mirror_frr.git] / lib / module.h

/*
 * Copyright (c) 2015-16  David Lamparter, for NetDEF, Inc.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef _FRR_MODULE_H
#define _FRR_MODULE_H

#include <stdint.h>
#include <stdbool.h>

#ifdef __cplusplus
extern "C" {
#endif

struct frrmod_runtime;

struct frrmod_info {
	/* single-line few-word title */
	const char *name;
	/* human-readable version number, should not contain spaces */
	const char *version;
	/* one-paragraph description */
	const char *description;

	int (*init)(void);
};

/* primary entry point structure to be present in loadable module under
 * "_frrmod_this_module" dlsym() name
 *
 * note space for future extensions is reserved below, so other modules
 * (e.g. memory management, hooks) can add fields
 *
 * const members/info are in frrmod_info.
 */
struct frrmod_runtime {
	struct frrmod_runtime *next;

	const struct frrmod_info *info;
	void *dl_handle;
	bool finished_loading;

	char *load_name;
	char *load_args;
};

/* space-reserving foo */
struct _frrmod_runtime_size {
	struct frrmod_runtime r;
	/* this will barf if frrmod_runtime exceeds 1024 bytes ... */
	uint8_t space[1024 - sizeof(struct frrmod_runtime)];
};
union _frrmod_runtime_u {
	struct frrmod_runtime r;
	struct _frrmod_runtime_size s;
};

extern union _frrmod_runtime_u _frrmod_this_module;
#define THIS_MODULE (&_frrmod_this_module.r)

#define FRR_COREMOD_SETUP(...)                                                 \
	static const struct frrmod_info _frrmod_info = {__VA_ARGS__};          \
	DSO_LOCAL union _frrmod_runtime_u _frrmod_this_module = {{             \
		NULL,                                                          \
		&_frrmod_info,                                                 \
	}};
#define FRR_MODULE_SETUP(...)                                                  \
	FRR_COREMOD_SETUP(__VA_ARGS__)                                         \
	DSO_SELF struct frrmod_runtime *frr_module = &_frrmod_this_module.r;

extern struct frrmod_runtime *frrmod_list;

extern void frrmod_init(struct frrmod_runtime *modinfo);
extern struct frrmod_runtime *frrmod_load(const char *spec, const char *dir,
					  char *err, size_t err_len);
#if 0
/* not implemented yet */
extern void frrmod_unload(struct frrmod_runtime *module);
#endif

#ifdef __cplusplus
}
#endif

#endif /* _FRR_MODULE_H */
Commit	Line	Data
30771d65 DL	1	/*
	2	* Copyright (c) 2015-16 David Lamparter, for NetDEF, Inc.
	3	*
bbfeedb5 DL	4	* Permission to use, copy, modify, and distribute this software for any
	5	* purpose with or without fee is hereby granted, provided that the above
	6	* copyright notice and this permission notice appear in all copies.
30771d65	7	*
bbfeedb5 DL	8	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	9	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	10	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	11	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	12	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
	13	* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
	14	* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
30771d65 DL	15	*/
	16
	17	#ifndef _FRR_MODULE_H
	18	#define _FRR_MODULE_H
	19
	20	#include <stdint.h>
	21	#include <stdbool.h>
	22
5e244469 RW	23	#ifdef __cplusplus
	24	extern "C" {
	25	#endif
	26
30771d65 DL	27	struct frrmod_runtime;
	28
	29	struct frrmod_info {
	30	/* single-line few-word title */
	31	const char *name;
	32	/* human-readable version number, should not contain spaces */
	33	const char *version;
	34	/* one-paragraph description */
	35	const char *description;
	36
	37	int (*init)(void);
	38	};
	39
	40	/* primary entry point structure to be present in loadable module under
	41	* "_frrmod_this_module" dlsym() name
	42	*
	43	* note space for future extensions is reserved below, so other modules
	44	* (e.g. memory management, hooks) can add fields
	45	*
	46	* const members/info are in frrmod_info.
	47	*/
	48	struct frrmod_runtime {
	49	struct frrmod_runtime *next;
	50
	51	const struct frrmod_info *info;
	52	void *dl_handle;
	53	bool finished_loading;
	54
	55	char *load_name;
	56	char *load_args;
	57	};
	58
	59	/* space-reserving foo */
	60	struct _frrmod_runtime_size {
	61	struct frrmod_runtime r;
	62	/* this will barf if frrmod_runtime exceeds 1024 bytes ... */
	63	uint8_t space[1024 - sizeof(struct frrmod_runtime)];
	64	};
	65	union _frrmod_runtime_u {
	66	struct frrmod_runtime r;
	67	struct _frrmod_runtime_size s;
	68	};
	69
	70	extern union _frrmod_runtime_u _frrmod_this_module;
	71	#define THIS_MODULE (&_frrmod_this_module.r)
	72
d62a17ae	73	#define FRR_COREMOD_SETUP(...) \
d62a17ae	74	static const struct frrmod_info _frrmod_info = {__VA_ARGS__}; \
7f04943d RW	75	DSO_LOCAL union _frrmod_runtime_u _frrmod_this_module = {{ \
	76	NULL, \
	77	&_frrmod_info, \
	78	}};
d62a17ae	79	#define FRR_MODULE_SETUP(...) \
d62a17ae	80	FRR_COREMOD_SETUP(__VA_ARGS__) \
30771d65 DL	81	DSO_SELF struct frrmod_runtime *frr_module = &_frrmod_this_module.r;
	82
	83	extern struct frrmod_runtime *frrmod_list;
	84
	85	extern void frrmod_init(struct frrmod_runtime *modinfo);
d62a17ae	86	extern struct frrmod_runtime frrmod_load(const char spec, const char *dir,
d62a17ae	87	char *err, size_t err_len);
30771d65 DL	88	#if 0
	89	/* not implemented yet */
	90	extern void frrmod_unload(struct frrmod_runtime *module);
	91	#endif
	92
5e244469 RW	93	#ifdef __cplusplus
	94	}
	95	#endif
	96
30771d65	97	#endif /* _FRR_MODULE_H */