summaryrefslogtreecommitdiffstats
path: root/lib/module.c
blob: 7d5671290bc75c28e056d4bde0bacb5eea476c9e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
/*
 * 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,
			.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 * 2], *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 (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