summaryrefslogtreecommitdiffstats
path: root/ldap/servers/slapd/dynalib.c
blob: a659a5e5b7bbce4ed95d86254371cfebf3bebc26 (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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
/** BEGIN COPYRIGHT BLOCK
 * This Program 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; version 2 of the License.
 * 
 * This Program 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.
 * 
 * In addition, as a special exception, Red Hat, Inc. gives You the additional
 * right to link the code of this Program with code not covered under the GNU
 * General Public License ("Non-GPL Code") and to distribute linked combinations
 * including the two, subject to the limitations in this paragraph. Non-GPL Code
 * permitted under this exception must only link to the code of this Program
 * through those well defined interfaces identified in the file named EXCEPTION
 * found in the source code files (the "Approved Interfaces"). The files of
 * Non-GPL Code may instantiate templates or use macros or inline functions from
 * the Approved Interfaces without causing the resulting work to be covered by
 * the GNU General Public License. Only Red Hat, Inc. may make changes or
 * additions to the list of Approved Interfaces. You must obey the GNU General
 * Public License in all respects for all of the Program code and other code used
 * in conjunction with the Program except the Non-GPL Code covered by this
 * exception. If you modify this file, you may extend this exception to your
 * version of the file, but you are not obligated to do so. If you do not wish to
 * provide this exception without modification, you must delete this exception
 * statement from your version and license this file solely under the GPL without
 * exception. 
 * 
 * 
 * Copyright (C) 2001 Sun Microsystems, Inc. Used by permission.
 * Copyright (C) 2005 Red Hat, Inc.
 * All rights reserved.
 * END COPYRIGHT BLOCK **/

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

/* dynalib.c - dynamic library routines */

#include <stdio.h>
#include "prlink.h"
#include "slap.h"
#if defined(SOLARIS)
#include <dlfcn.h> /* dlerror */
#endif


static struct dynalib {
	char		*dl_name;
	PRLibrary	*dl_handle;
} **libs = NULL;

static void symload_report_error( const char *libpath, char *symbol, char *plugin,
		int libopen );

/* construct a full path and name of a plugin
   very similar to PR_GetLibraryName except that function inserts
   the string "lib" at the beginning of name, making that function
   unsuitable for constructing plugin names
*/
static char *get_plugin_name(const char *dir, const char *name);

static void free_plugin_name(char *name)
{
	PR_smprintf_free(name);
}

void *
sym_load( char *libpath, char *symbol, char *plugin, int report_errors )
{
	return sym_load_with_flags(libpath, symbol, plugin, report_errors, PR_FALSE, PR_FALSE);
}

/* libpath is the pathname from the plugin config entry - it may be an absolute path
   or a relative path.  It does not have to have the shared lib/dll suffix.  The
   PR_GetLibraryName function will create the correct library name and path, including
   the correct shared library suffix for the platform.  So, for example, if you just
   pass in "libacl-plugin" as the libpath, and you are running on linux, the code
   will first test for the existence of "libacl-plugin", then will construct the full
   pathname to load as "PLUGINDIR/libacl-plugin.so" where PLUGINDIR is set during
   build time to something like /usr/lib/brand/plugins.
*/
void *
sym_load_with_flags( char *libpath, char *symbol, char *plugin, int report_errors, PRBool load_now, PRBool load_global )
{
	int	i;
	void	*handle;
	PRLibSpec libSpec;
	unsigned int flags = PR_LD_LAZY; /* default PR_LoadLibrary flag */

	libSpec.type = PR_LibSpec_Pathname;
	libSpec.value.pathname = libpath;

	for ( i = 0; libs != NULL && libs[i] != NULL; i++ ) {
		if ( strcasecmp( libs[i]->dl_name, libpath ) == 0 ) {
			handle = PR_FindSymbol( libs[i]->dl_handle, symbol );
			if ( NULL == handle && report_errors ) {
				symload_report_error( libpath, symbol, plugin, 1 /* lib open */ );
			}
			return handle;
		}
	}

	if (load_now) {
		flags = PR_LD_NOW;
	}
	if (load_global) {
		flags |= PR_LD_GLOBAL;
	}

	if (PR_SUCCESS != PR_Access(libpath, PR_ACCESS_READ_OK)) {
		libSpec.value.pathname = get_plugin_name(PLUGINDIR, libpath);
		/* then just handle that failure case with symload_report_error below */
	}

	if ( (handle = PR_LoadLibraryWithFlags( libSpec, flags )) == NULL ) {
		if ( report_errors ) {
			symload_report_error( libSpec.value.pathname, symbol, plugin, 0 /* lib not open */ );
		}
		if (libSpec.value.pathname != libpath) {
			free_plugin_name((char *)libSpec.value.pathname); /* cast ok - allocated by get_plugin_name */
		}
		return( NULL );
	}

	libs = (struct dynalib **) slapi_ch_realloc( (char *) libs, (i + 2) *
	    sizeof(struct dynalib) );
	libs[i] = (struct dynalib *) slapi_ch_malloc( sizeof(struct dynalib) );
	libs[i]->dl_name = slapi_ch_strdup( libpath );
	libs[i]->dl_handle = handle;
	libs[ i + 1 ] = NULL;

	handle = PR_FindSymbol( libs[i]->dl_handle, symbol );
	if ( NULL == handle && report_errors ) {
		symload_report_error( libSpec.value.pathname, symbol, plugin, 1 /* lib open */ );
	}
	if (libSpec.value.pathname != libpath) {
		free_plugin_name((char *)libSpec.value.pathname); /* cast ok - allocated by PR_GetLibraryName */
	}
	return handle;
}


static void
symload_report_error( const char *libpath, char *symbol, char *plugin, int libopen )
{
	char	*errtext = NULL;
	PRInt32	errlen;

	errlen = PR_GetErrorTextLength();
	if ( errlen > 0 ) {
		errtext = slapi_ch_malloc( errlen+1 );
		if ( PR_GetErrorText( errtext ) > 0 ) {
			LDAPDebug( LDAP_DEBUG_ANY, SLAPI_COMPONENT_NAME_NSPR " error %d: %s\n",
				PR_GetError(), errtext, 0 );
		}
		slapi_ch_free( (void **)&errtext );
	}
	if ( libopen ) {
		LDAPDebug( LDAP_DEBUG_ANY,
			"Could not load symbol \"%s\" from \"%s\" for plugin %s\n",
					symbol, libpath, plugin );
	} else {
		LDAPDebug( LDAP_DEBUG_ANY,
			"Could not open library \"%s\" for plugin %s\n",
			libpath, plugin, 0 );
	}
}

/* PR_GetLibraryName does almost everything we need, and unfortunately
   a little bit more - it adds "lib" to be beginning of the library
   name if the library name does not end with the current platform
   DLL suffix - so
   foo.so -> /path/foo.so
   libfoo.so -> /path/libfoo.so
   BUT
   foo -> /path/libfoo.so
   libfoo -> /path/liblibfoo.so
*/
static char *
get_plugin_name(const char *path, const char *lib)
{
    const char *libstr = "/lib";
    size_t libstrlen = 4;
	char *fullname = PR_GetLibraryName(path, lib);
	char *ptr = PL_strrstr(fullname, lib);

    /* see if /lib was added */
	if (ptr && ((ptr - fullname) >= libstrlen)) {
        /* ptr is at the libname in fullname, and there is something before it */
        ptr -= libstrlen; /* ptr now points at the "/" in "/lib" if it is there */
        if (0 == PL_strncmp(ptr, libstr, libstrlen)) {
            /* just copy the remainder of the string on top of here */
            ptr++; /* ptr now points at the "l" in "/lib" - keep the "/" */
            memmove(ptr, ptr+3, strlen(ptr+3)+1);
        }
	}

	return fullname;
}