1#ifndef lint
2static char *rcsid = "$Id: stub.c,v 1.1 2003/06/04 00:27:13 marka Exp $";
3#endif
4
5/*
6 * Copyright (c) 2001 Japan Network Information Center.  All rights reserved.
7 *
8 * By using this file, you agree to the terms and conditions set forth bellow.
9 *
10 * 			LICENSE TERMS AND CONDITIONS
11 *
12 * The following License Terms and Conditions apply, unless a different
13 * license is obtained from Japan Network Information Center ("JPNIC"),
14 * a Japanese association, Kokusai-Kougyou-Kanda Bldg 6F, 2-3-4 Uchi-Kanda,
15 * Chiyoda-ku, Tokyo 101-0047, Japan.
16 *
17 * 1. Use, Modification and Redistribution (including distribution of any
18 *    modified or derived work) in source and/or binary forms is permitted
19 *    under this License Terms and Conditions.
20 *
21 * 2. Redistribution of source code must retain the copyright notices as they
22 *    appear in each source code file, this License Terms and Conditions.
23 *
24 * 3. Redistribution in binary form must reproduce the Copyright Notice,
25 *    this License Terms and Conditions, in the documentation and/or other
26 *    materials provided with the distribution.  For the purposes of binary
27 *    distribution the "Copyright Notice" refers to the following language:
28 *    "Copyright (c) 2000-2002 Japan Network Information Center.  All rights reserved."
29 *
30 * 4. The name of JPNIC may not be used to endorse or promote products
31 *    derived from this Software without specific prior written approval of
32 *    JPNIC.
33 *
34 * 5. Disclaimer/Limitation of Liability: THIS SOFTWARE IS PROVIDED BY JPNIC
35 *    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
36 *    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
37 *    PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL JPNIC BE LIABLE
38 *    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
39 *    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
40 *    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
41 *    BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
42 *    WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
43 *    OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
44 *    ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
45 */
46
47#include <config.h>
48
49#include <stdarg.h>
50#include <stdlib.h>
51#include <string.h>
52#include <sys/types.h>
53#include <sys/socket.h>
54#include <netdb.h>
55#include <errno.h>
56#ifdef HAVE_DLFCN_H
57#include <dlfcn.h>
58#endif
59
60#include <idn/logmacro.h>
61#include <idn/debug.h>
62
63#include "stub.h"
64
65#ifndef RTLD_NEXT
66typedef struct {
67	const char *name;
68	void *handle;
69} shared_obj_t;
70
71static shared_obj_t shobj[] = {
72#ifdef SOPATH_LIBC
73	{ SOPATH_LIBC },
74#endif
75#ifdef SOPATH_LIBNSL
76	{ SOPATH_LIBNSL },
77#endif
78	{ NULL },
79};
80#endif
81
82static void	*shared_obj_findsym(void *handle, const char *name);
83static void	*shared_obj_findsymx(void *handle, const char *name);
84static void	*get_func_addr(const char *name);
85
86#ifndef RTLD_NEXT
87static void *
88shared_obj_open(const char *path) {
89#ifdef HAVE_DLOPEN
90	return (dlopen(path, RTLD_LAZY));
91#endif
92	FATAL(("stub: no way to load shared object file\n"));
93	return (NULL);
94}
95#endif
96
97static void *
98shared_obj_findsym(void *handle, const char *name) {
99	char namebuf[100];
100	void *addr;
101	static int need_leading_underscore = -1;
102
103	/* Prepend underscore. */
104	namebuf[0] = '_';
105	(void)strcpy(namebuf + 1, name);
106	name = namebuf;
107
108	if (need_leading_underscore < 0) {
109		/* First try without one. */
110		if ((addr = shared_obj_findsymx(handle, name + 1)) != NULL) {
111			need_leading_underscore = 0;
112			return (addr);
113		}
114		/* Then try with one. */
115		if ((addr = shared_obj_findsymx(handle, name)) != NULL) {
116			need_leading_underscore = 1;
117			return (addr);
118		}
119	} else if (need_leading_underscore) {
120		return (shared_obj_findsymx(handle, name));
121	} else {
122		return (shared_obj_findsymx(handle, name + 1));
123	}
124	return (NULL);
125}
126
127static void *
128shared_obj_findsymx(void *handle, const char *name) {
129#ifdef HAVE_DLSYM
130	return (dlsym(handle, name));
131#endif
132	/* logging */
133	FATAL(("stub: no way to get symbol address\n"));
134	return (NULL);
135}
136
137static void *
138get_func_addr(const char *name) {
139#ifdef RTLD_NEXT
140	void *addr = shared_obj_findsym(RTLD_NEXT, name);
141
142	if (addr != NULL) {
143		TRACE(("stub: %s found in the subsequent objects\n", name));
144		return (addr);
145	}
146#else
147	int i;
148
149	for (i = 0; shobj[i].name != NULL; i++) {
150		if (shobj[i].handle == NULL) {
151			TRACE(("stub: loading %s\n", shobj[i].name));
152			shobj[i].handle = shared_obj_open(shobj[i].name);
153		}
154		if (shobj[i].handle != NULL) {
155			void *addr = shared_obj_findsym(shobj[i].handle, name);
156			if (addr != NULL) {
157				TRACE(("stub: %s found in %s\n",
158				       name, shobj[i].name));
159				return (addr);
160			}
161		}
162	}
163#endif
164	TRACE(("stub: %s not found\n", name));
165	return (NULL);
166}
167
168#ifdef HAVE_GETHOSTBYNAME
169struct hostent *
170idn_stub_gethostbyname(const char *name) {
171	static struct hostent *(*fp)(const char *name);
172
173	if (fp == NULL)
174		fp = get_func_addr("gethostbyname");
175	if (fp != NULL)
176		return ((*fp)(name));
177	return (NULL);
178}
179#endif
180
181#ifdef HAVE_GETHOSTBYNAME2
182struct hostent *
183idn_stub_gethostbyname2(const char *name, int af) {
184	static struct hostent *(*fp)(const char *name, int af);
185
186	if (fp == NULL)
187		fp = get_func_addr("gethostbyname2");
188	if (fp != NULL)
189		return ((*fp)(name, af));
190	return (NULL);
191}
192#endif
193
194#ifdef HAVE_GETHOSTBYADDR
195struct hostent *
196idn_stub_gethostbyaddr(GHBA_ADDR_T addr, GHBA_ADDRLEN_T len, int type) {
197	static struct hostent *(*fp)(GHBA_ADDR_T name,
198				     GHBA_ADDRLEN_T len, int type);
199
200	if (fp == NULL)
201		fp = get_func_addr("gethostbyaddr");
202	if (fp != NULL)
203		return ((*fp)(addr, len, type));
204	return (NULL);
205}
206#endif
207
208#ifdef GETHOST_R_GLIBC_FLAVOR
209
210#ifdef HAVE_GETHOSTBYNAME_R
211int
212idn_stub_gethostbyname_r(const char *name, struct hostent *result,
213			 char *buffer, size_t buflen,
214			 struct hostent **rp, int *errp)
215{
216	static int (*fp)(const char *name, struct hostent *result,
217			 char *buffer, size_t buflen,
218			 struct hostent **rp, int *errp);
219
220	if (fp == NULL)
221		fp = get_func_addr("gethostbyname_r");
222	if (fp != NULL)
223		return ((*fp)(name, result, buffer, buflen, rp, errp));
224	return (ENOENT);	/* ??? */
225}
226#endif
227
228#ifdef HAVE_GETHOSTBYNAME2_R
229int
230idn_stub_gethostbyname2_r(const char *name, int af, struct hostent *result,
231			  char *buffer, size_t buflen,
232			  struct hostent **rp, int *errp)
233{
234	static int (*fp)(const char *name, int af, struct hostent *result,
235			 char *buffer, size_t buflen,
236			 struct hostent **rp, int *errp);
237
238	if (fp == NULL)
239		fp = get_func_addr("gethostbyname2_r");
240	if (fp != NULL)
241		return ((*fp)(name, af, result, buffer, buflen, rp, errp));
242	return (ENOENT);	/* ??? */
243}
244#endif
245
246#ifdef HAVE_GETHOSTBYADDR_R
247int
248idn_stub_gethostbyaddr_r(GHBA_ADDR_T addr, GHBA_ADDRLEN_T len, int type,
249			 struct hostent *result, char *buffer,
250			 size_t buflen, struct hostent **rp, int *errp)
251{
252	static int (*fp)(GHBA_ADDR_T addr, GHBA_ADDRLEN_T len, int type,
253			 struct hostent *result, char *buffer,
254			 size_t buflen, struct hostent **rp, int *errp);
255
256	if (fp == NULL)
257		fp = get_func_addr("gethostbyaddr_r");
258	if (fp != NULL)
259		return ((*fp)(addr, len, type, result,
260			      buffer, buflen, rp, errp));
261	return (ENOENT);	/* ??? */
262}
263#endif
264
265#else /* GETHOST_R_GLIBC_FLAVOR */
266
267#ifdef HAVE_GETHOSTBYNAME_R
268struct hostent *
269idn_stub_gethostbyname_r(const char *name, struct hostent *result,
270			 char *buffer, int buflen, int *errp)
271{
272	static struct hostent *(*fp)(const char *name, struct hostent *result,
273				     char *buffer, int buflen, int *errp);
274
275	if (fp == NULL)
276		fp = get_func_addr("gethostbyname_r");
277	if (fp != NULL)
278		return ((*fp)(name, result, buffer, buflen, errp));
279	return (NULL);
280}
281#endif
282
283#ifdef HAVE_GETHOSTBYADDR_R
284struct hostent *
285idn_stub_gethostbyaddr_r(GHBA_ADDR_T addr, int len, int type,
286			 struct hostent *result, char *buffer,
287			 int buflen, int *errp)
288{
289	static struct hostent *(*fp)(GHBA_ADDR_T addr, int len, int type,
290				     struct hostent *result, char *buffer,
291				     int buflen, int *errp);
292
293	if (fp == NULL)
294		fp = get_func_addr("gethostbyaddr_r");
295	if (fp != NULL)
296		return ((*fp)(addr, len, type, result, buffer, buflen, errp));
297	return (NULL);
298}
299#endif
300
301#endif /* GETHOST_R_GLIBC_FLAVOR */
302
303#ifdef HAVE_GETIPNODEBYNAME
304struct hostent *
305idn_stub_getipnodebyname(const char *name, int af, int flags, int *errp) {
306	static struct hostent *(*fp)(const char *name, int af, int flags,
307				     int *errp);
308
309	if (fp == NULL)
310		fp = get_func_addr("getipnodebyname");
311	if (fp != NULL)
312		return ((*fp)(name, af, flags, errp));
313	return (NULL);
314}
315#endif
316
317#ifdef HAVE_GETIPNODEBYADDR
318struct hostent *
319idn_stub_getipnodebyaddr(const void *src, size_t len, int af, int *errp) {
320	static struct hostent *(*fp)(const void *src, size_t len, int af,
321				     int *errp);
322
323	if (fp == NULL)
324		fp = get_func_addr("getipnodebyaddr");
325	if (fp != NULL)
326		return ((*fp)(src, len, af, errp));
327	return (NULL);
328}
329#endif
330
331#ifdef HAVE_FREEHOSTENT
332void
333idn_stub_freehostent(struct hostent *hp) {
334	static void (*fp)(struct hostent *hp);
335
336	if (fp == NULL)
337		fp = get_func_addr("freehostent");
338	if (fp != NULL)
339		(*fp)(hp);
340}
341#endif
342
343#ifdef HAVE_GETADDRINFO
344int
345idn_stub_getaddrinfo(const char *nodename, const char *servname,
346		     const struct addrinfo *hints, struct addrinfo **res)
347{
348	static int (*fp)(const char *nodename, const char *servname,
349			 const struct addrinfo *hints, struct addrinfo **res);
350
351	if (fp == NULL)
352		fp = get_func_addr("getaddrinfo");
353	if (fp != NULL)
354		return ((*fp)(nodename, servname, hints, res));
355	return (EAI_FAIL);
356}
357#endif
358
359#ifdef HAVE_FREEADDRINFO
360void
361idn_stub_freeaddrinfo(struct addrinfo *aip) {
362	static void (*fp)(struct addrinfo *aip);
363
364	if (fp == NULL)
365		fp = get_func_addr("freeaddrinfo");
366	if (fp != NULL)
367		(*fp)(aip);
368}
369#endif
370
371#ifdef HAVE_GETNAMEINFO
372int
373idn_stub_getnameinfo(const struct sockaddr *sa, GNI_SALEN_T salen,
374		     char *host, GNI_HOSTLEN_T hostlen,
375		     char *serv, GNI_SERVLEN_T servlen, GNI_FLAGS_T flags) {
376	static int (*fp)(const struct sockaddr *sa, GNI_SALEN_T salen,
377			 char *host, GNI_HOSTLEN_T hostlen,
378			 char *serv, GNI_SERVLEN_T servlen,
379			 GNI_FLAGS_T flags);
380
381	if (fp == NULL)
382		fp = get_func_addr("getnameinfo");
383	if (fp != NULL)
384		return ((*fp)(sa, salen, host, hostlen, serv, servlen, flags));
385	return (EAI_FAIL);
386}
387#endif
388