[mirror_frr.git] / lib / module.h

/*
 * Copyright (c) 2015-16  David Lamparter, for NetDEF, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#ifndef _FRR_MODULE_H
#define _FRR_MODULE_H

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

#if !defined(__GNUC__)
# error module code needs GCC visibility extensions
#elif __GNUC__ < 4
# error module code needs GCC visibility extensions
#else
# define DSO_PUBLIC __attribute__ ((visibility ("default")))
# define DSO_SELF   __attribute__ ((visibility ("protected")))
# define DSO_LOCAL  __attribute__ ((visibility ("hidden")))
#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 = { \
		.r.info = &_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,
		char *err, size_t err_len);
#if 0
/* not implemented yet */
extern void frrmod_unload(struct frrmod_runtime *module);
#endif

#endif /* _FRR_MODULE_H */
Commit	Line	Data
30771d65 DL	1	/*
	2	* Copyright (c) 2015-16 David Lamparter, for NetDEF, Inc.
	3	*
	4	* Permission is hereby granted, free of charge, to any person obtaining a
	5	* copy of this software and associated documentation files (the "Software"),
	6	* to deal in the Software without restriction, including without limitation
	7	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	8	* and/or sell copies of the Software, and to permit persons to whom the
	9	* Software is furnished to do so, subject to the following conditions:
	10	*
	11	* The above copyright notice and this permission notice shall be included in
	12	* all copies or substantial portions of the Software.
	13	*
	14	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	15	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	16	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	17	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	18	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
	19	* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
	20	* DEALINGS IN THE SOFTWARE.
	21	*/
	22
	23	#ifndef _FRR_MODULE_H
	24	#define _FRR_MODULE_H
	25
	26	#include <stdint.h>
	27	#include <stdbool.h>
	28
	29	#if !defined(__GNUC__)
	30	# error module code needs GCC visibility extensions
	31	#elif __GNUC__ < 4
	32	# error module code needs GCC visibility extensions
	33	#else
	34	# define DSO_PUBLIC __attribute__ ((visibility ("default")))
	35	# define DSO_SELF __attribute__ ((visibility ("protected")))
	36	# define DSO_LOCAL __attribute__ ((visibility ("hidden")))
	37	#endif
	38
	39	struct frrmod_runtime;
	40
	41	struct frrmod_info {
	42	/* single-line few-word title */
	43	const char *name;
	44	/* human-readable version number, should not contain spaces */
	45	const char *version;
	46	/* one-paragraph description */
	47	const char *description;
	48
	49	int (*init)(void);
	50	};
	51
	52	/* primary entry point structure to be present in loadable module under
	53	* "_frrmod_this_module" dlsym() name
	54	*
	55	* note space for future extensions is reserved below, so other modules
	56	* (e.g. memory management, hooks) can add fields
	57	*
	58	* const members/info are in frrmod_info.
	59	*/
	60	struct frrmod_runtime {
	61	struct frrmod_runtime *next;
	62
	63	const struct frrmod_info *info;
	64	void *dl_handle;
65	bool finished_loading;
66
67	char *load_name;
68	char *load_args;
69	};
70
71	/* space-reserving foo */
72	struct _frrmod_runtime_size {
73	struct frrmod_runtime r;
74	/* this will barf if frrmod_runtime exceeds 1024 bytes ... */
75	uint8_t space[1024 - sizeof(struct frrmod_runtime)];
76	};
77	union _frrmod_runtime_u {
78	struct frrmod_runtime r;
79	struct _frrmod_runtime_size s;
80	};
81
82	extern union _frrmod_runtime_u _frrmod_this_module;
83	#define THIS_MODULE (&_frrmod_this_module.r)
84
85	#define FRR_COREMOD_SETUP(...) \
86	static const struct frrmod_info _frrmod_info = { __VA_ARGS__ }; \
87	DSO_LOCAL union _frrmod_runtime_u _frrmod_this_module = { \
88	.r.info = &_frrmod_info, \
89	};
90	#define FRR_MODULE_SETUP(...) \
91	FRR_COREMOD_SETUP(__VA_ARGS__) \
92	DSO_SELF struct frrmod_runtime *frr_module = &_frrmod_this_module.r;
93
94	extern struct frrmod_runtime *frrmod_list;
95
96	extern void frrmod_init(struct frrmod_runtime *modinfo);
97	extern struct frrmod_runtime frrmod_load(const char spec,
98	char *err, size_t err_len);
99	#if 0
100	/* not implemented yet */
101	extern void frrmod_unload(struct frrmod_runtime *module);
102	#endif
103
104	#endif /* _FRR_MODULE_H */