[mirror_frr.git] / lib / module.c

/*
 * 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.
 */

#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include <dlfcn.h>

#include "module.h"
#include "memory.h"
#include "version.h"

DEFINE_MTYPE_STATIC(LIB, MODULE_LOADNAME, "Module loading name")
DEFINE_MTYPE_STATIC(LIB, MODULE_LOADARGS, "Module loading arguments")

static struct frrmod_info frrmod_default_info = {
	.name = "libfrr",
	.version = FRR_VERSION,
	.description = "libfrr core module",
};
union _frrmod_runtime_u frrmod_default = {
	.r.info = &frrmod_default_info,
	.r.finished_loading = 1,
};

// if defined(HAVE_SYS_WEAK_ALIAS_ATTRIBUTE)
// union _frrmod_runtime_u _frrmod_this_module
//	__attribute__((weak, alias("frrmod_default")));
// elif defined(HAVE_SYS_WEAK_ALIAS_PRAGMA)
#pragma weak _frrmod_this_module = frrmod_default
// else
// error need weak symbol support
// endif

struct frrmod_runtime *frrmod_list = &frrmod_default.r;
static struct frrmod_runtime **frrmod_last = &frrmod_default.r.next;
static const char *execname = NULL;

void frrmod_init(struct frrmod_runtime *modinfo)
{
	modinfo->finished_loading = 1;
	*frrmod_last = modinfo;
	frrmod_last = &modinfo->next;

	execname = modinfo->info->name;
}

struct frrmod_runtime *frrmod_load(const char *spec, const char *dir, char *err,
				   size_t err_len)
{
	void *handle = NULL;
	char name[PATH_MAX], fullpath[PATH_MAX], *args;
	struct frrmod_runtime *rtinfo, **rtinfop;
	const struct frrmod_info *info;

	snprintf(name, sizeof(name), "%s", spec);
	args = strchr(name, ':');
	if (args)
		*args++ = '\0';

	if (!strchr(name, '/')) {
		if (!handle && execname) {
			snprintf(fullpath, sizeof(fullpath), "%s/%s_%s.so", dir,
				 execname, name);
			handle = dlopen(fullpath, RTLD_NOW | RTLD_GLOBAL);
		}
		if (!handle) {
			snprintf(fullpath, sizeof(fullpath), "%s/%s.so", dir,
				 name);
			handle = dlopen(fullpath, RTLD_NOW | RTLD_GLOBAL);
		}
	}
	if (!handle) {
		snprintf(fullpath, sizeof(fullpath), "%s", name);
		handle = dlopen(fullpath, RTLD_NOW | RTLD_GLOBAL);
	}
	if (!handle) {
		if (err)
			snprintf(err, err_len,
				 "loading module \"%s\" failed: %s", name,
				 dlerror());
		return NULL;
	}

	rtinfop = dlsym(handle, "frr_module");
	if (!rtinfop) {
		dlclose(handle);
		if (err)
			snprintf(err, err_len,
				 "\"%s\" is not an FRR module: %s", name,
				 dlerror());
		return NULL;
	}
	rtinfo = *rtinfop;
	rtinfo->load_name = XSTRDUP(MTYPE_MODULE_LOADNAME, name);
	rtinfo->dl_handle = handle;
	if (args)
		rtinfo->load_args = XSTRDUP(MTYPE_MODULE_LOADARGS, args);
	info = rtinfo->info;

	if (rtinfo->finished_loading) {
		dlclose(handle);
		if (err)
			snprintf(err, err_len, "module \"%s\" already loaded",
				 name);
		goto out_fail;
	}

	if (info->init && info->init()) {
		dlclose(handle);
		if (err)
			snprintf(err, err_len,
				 "module \"%s\" initialisation failed", name);
		goto out_fail;
	}

	rtinfo->finished_loading = 1;

	*frrmod_last = rtinfo;
	frrmod_last = &rtinfo->next;
	return rtinfo;

out_fail:
	if (rtinfo->load_args)
		XFREE(MTYPE_MODULE_LOADARGS, rtinfo->load_args);
	XFREE(MTYPE_MODULE_LOADNAME, rtinfo->load_name);
	return NULL;
}

#if 0
void frrmod_unload(struct frrmod_runtime *module)
{
}
#endif
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	#include "config.h"
	24
	25	#include <stdlib.h>
	26	#include <stdio.h>
	27	#include <string.h>
	28	#include <unistd.h>
	29	#include <limits.h>
	30	#include <dlfcn.h>
	31
	32	#include "module.h"
	33	#include "memory.h"
	34	#include "version.h"
	35
	36	DEFINE_MTYPE_STATIC(LIB, MODULE_LOADNAME, "Module loading name")
	37	DEFINE_MTYPE_STATIC(LIB, MODULE_LOADARGS, "Module loading arguments")
	38
	39	static struct frrmod_info frrmod_default_info = {
	40	.name = "libfrr",
	41	.version = FRR_VERSION,
	42	.description = "libfrr core module",
	43	};
	44	union _frrmod_runtime_u frrmod_default = {
	45	.r.info = &frrmod_default_info,
	46	.r.finished_loading = 1,
	47	};
	48
	49	// if defined(HAVE_SYS_WEAK_ALIAS_ATTRIBUTE)
	50	// union _frrmod_runtime_u _frrmod_this_module
	51	// __attribute__((weak, alias("frrmod_default")));
	52	// elif defined(HAVE_SYS_WEAK_ALIAS_PRAGMA)
	53	#pragma weak _frrmod_this_module = frrmod_default
	54	// else
	55	// error need weak symbol support
	56	// endif
	57
	58	struct frrmod_runtime *frrmod_list = &frrmod_default.r;
	59	static struct frrmod_runtime **frrmod_last = &frrmod_default.r.next;
	60	static const char *execname = NULL;
	61
	62	void frrmod_init(struct frrmod_runtime *modinfo)
	63	{
	64	modinfo->finished_loading = 1;
65	*frrmod_last = modinfo;
66	frrmod_last = &modinfo->next;
67
68	execname = modinfo->info->name;
69	}
70
d62a17ae	71	struct frrmod_runtime frrmod_load(const char spec, const char dir, char err,
d62a17ae	72	size_t err_len)
30771d65 DL	73	{
	74	void *handle = NULL;
	75	char name[PATH_MAX], fullpath[PATH_MAX], *args;
	76	struct frrmod_runtime rtinfo, *rtinfop;
	77	const struct frrmod_info *info;
	78
	79	snprintf(name, sizeof(name), "%s", spec);
	80	args = strchr(name, ':');
	81	if (args)
	82	*args++ = '\0';
	83
	84	if (!strchr(name, '/')) {
	85	if (!handle && execname) {
d62a17ae	86	snprintf(fullpath, sizeof(fullpath), "%s/%s_%s.so", dir,
d62a17ae	87	execname, name);
30771d65 DL	88	handle = dlopen(fullpath, RTLD_NOW \| RTLD_GLOBAL);
	89	}
	90	if (!handle) {
d62a17ae	91	snprintf(fullpath, sizeof(fullpath), "%s/%s.so", dir,
d62a17ae	92	name);
30771d65 DL	93	handle = dlopen(fullpath, RTLD_NOW \| RTLD_GLOBAL);
	94	}
	95	}
	96	if (!handle) {
	97	snprintf(fullpath, sizeof(fullpath), "%s", name);
	98	handle = dlopen(fullpath, RTLD_NOW \| RTLD_GLOBAL);
	99	}
	100	if (!handle) {
	101	if (err)
	102	snprintf(err, err_len,
d62a17ae	103	"loading module \"%s\" failed: %s", name,
d62a17ae	104	dlerror());
30771d65 DL	105	return NULL;
	106	}
	107
	108	rtinfop = dlsym(handle, "frr_module");
	109	if (!rtinfop) {
	110	dlclose(handle);
	111	if (err)
	112	snprintf(err, err_len,
d62a17ae	113	"\"%s\" is not an FRR module: %s", name,
d62a17ae	114	dlerror());
30771d65 DL	115	return NULL;
	116	}
	117	rtinfo = *rtinfop;
	118	rtinfo->load_name = XSTRDUP(MTYPE_MODULE_LOADNAME, name);
	119	rtinfo->dl_handle = handle;
	120	if (args)
	121	rtinfo->load_args = XSTRDUP(MTYPE_MODULE_LOADARGS, args);
	122	info = rtinfo->info;
	123
	124	if (rtinfo->finished_loading) {
	125	dlclose(handle);
	126	if (err)
d62a17ae	127	snprintf(err, err_len, "module \"%s\" already loaded",
d62a17ae	128	name);
30771d65 DL	129	goto out_fail;
	130	}
	131
	132	if (info->init && info->init()) {
	133	dlclose(handle);
	134	if (err)
	135	snprintf(err, err_len,
d62a17ae	136	"module \"%s\" initialisation failed", name);
30771d65 DL	137	goto out_fail;
	138	}
	139
	140	rtinfo->finished_loading = 1;
	141
	142	*frrmod_last = rtinfo;
	143	frrmod_last = &rtinfo->next;
	144	return rtinfo;
	145
	146	out_fail:
	147	if (rtinfo->load_args)
	148	XFREE(MTYPE_MODULE_LOADARGS, rtinfo->load_args);
	149	XFREE(MTYPE_MODULE_LOADNAME, rtinfo->load_name);
	150	return NULL;
	151	}
	152
	153	#if 0
	154	void frrmod_unload(struct frrmod_runtime *module)
	155	{
	156	}
	157	#endif