1 /*
2 * Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 /*
11 * We need to do this early, because stdio.h includes the header files that
12 * handle _GNU_SOURCE and other similar macros. Defining it later is simply
13 * too late, because those headers are protected from re- inclusion.
14 */
15 #ifndef _GNU_SOURCE
16 # define _GNU_SOURCE /* make sure dladdr is declared */
17 #endif
18
19 #include "dso_local.h"
20 #include "e_os.h"
21
22 #ifdef DSO_DLFCN
23
24 # ifdef HAVE_DLFCN_H
25 # ifdef __osf__
26 # define __EXTENSIONS__
27 # endif
28 # include <dlfcn.h>
29 # define HAVE_DLINFO 1
30 # if defined(__SCO_VERSION__) || defined(_SCO_ELF) || \
31 (defined(__osf__) && !defined(RTLD_NEXT)) || \
32 (defined(__OpenBSD__) && !defined(RTLD_SELF)) || \
33 defined(__ANDROID__) || defined(__TANDEM)
34 # undef HAVE_DLINFO
35 # endif
36 # endif
37
38 /* Part of the hack in "dlfcn_load" ... */
39 # define DSO_MAX_TRANSLATED_SIZE 256
40
41 static int dlfcn_load(DSO *dso);
42 static int dlfcn_unload(DSO *dso);
43 static DSO_FUNC_TYPE dlfcn_bind_func(DSO *dso, const char *symname);
44 static char *dlfcn_name_converter(DSO *dso, const char *filename);
45 static char *dlfcn_merger(DSO *dso, const char *filespec1,
46 const char *filespec2);
47 static int dlfcn_pathbyaddr(void *addr, char *path, int sz);
48 static void *dlfcn_globallookup(const char *name);
49
50 static DSO_METHOD dso_meth_dlfcn = {
51 "OpenSSL 'dlfcn' shared library method",
52 dlfcn_load,
53 dlfcn_unload,
54 dlfcn_bind_func,
55 NULL, /* ctrl */
56 dlfcn_name_converter,
57 dlfcn_merger,
58 NULL, /* init */
59 NULL, /* finish */
60 dlfcn_pathbyaddr,
61 dlfcn_globallookup
62 };
63
DSO_METHOD_openssl(void)64 DSO_METHOD *DSO_METHOD_openssl(void)
65 {
66 return &dso_meth_dlfcn;
67 }
68
69 /*
70 * Prior to using the dlopen() function, we should decide on the flag we
71 * send. There's a few different ways of doing this and it's a messy
72 * venn-diagram to match up which platforms support what. So as we don't have
73 * autoconf yet, I'm implementing a hack that could be hacked further
74 * relatively easily to deal with cases as we find them. Initially this is to
75 * cope with OpenBSD.
76 */
77 # if defined(__OpenBSD__) || defined(__NetBSD__)
78 # ifdef DL_LAZY
79 # define DLOPEN_FLAG DL_LAZY
80 # else
81 # ifdef RTLD_NOW
82 # define DLOPEN_FLAG RTLD_NOW
83 # else
84 # define DLOPEN_FLAG 0
85 # endif
86 # endif
87 # else
88 # define DLOPEN_FLAG RTLD_NOW /* Hope this works everywhere else */
89 # endif
90
91 /*
92 * For this DSO_METHOD, our meth_data STACK will contain; (i) the handle
93 * (void*) returned from dlopen().
94 */
95
dlfcn_load(DSO * dso)96 static int dlfcn_load(DSO *dso)
97 {
98 void *ptr = NULL;
99 /* See applicable comments in dso_dl.c */
100 char *filename = DSO_convert_filename(dso, NULL);
101 int flags = DLOPEN_FLAG;
102 int saveerrno = get_last_sys_error();
103
104 if (filename == NULL) {
105 ERR_raise(ERR_LIB_DSO, DSO_R_NO_FILENAME);
106 goto err;
107 }
108 # ifdef RTLD_GLOBAL
109 if (dso->flags & DSO_FLAG_GLOBAL_SYMBOLS)
110 flags |= RTLD_GLOBAL;
111 # endif
112 # ifdef _AIX
113 if (filename[strlen(filename) - 1] == ')')
114 flags |= RTLD_MEMBER;
115 # endif
116 ptr = dlopen(filename, flags);
117 if (ptr == NULL) {
118 ERR_raise_data(ERR_LIB_DSO, DSO_R_LOAD_FAILED,
119 "filename(%s): %s", filename, dlerror());
120 goto err;
121 }
122 /*
123 * Some dlopen() implementations (e.g. solaris) do no preserve errno, even
124 * on a successful call.
125 */
126 set_sys_error(saveerrno);
127 if (!sk_void_push(dso->meth_data, (char *)ptr)) {
128 ERR_raise(ERR_LIB_DSO, DSO_R_STACK_ERROR);
129 goto err;
130 }
131 /* Success */
132 dso->loaded_filename = filename;
133 return 1;
134 err:
135 /* Cleanup! */
136 OPENSSL_free(filename);
137 if (ptr != NULL)
138 dlclose(ptr);
139 return 0;
140 }
141
dlfcn_unload(DSO * dso)142 static int dlfcn_unload(DSO *dso)
143 {
144 void *ptr;
145 if (dso == NULL) {
146 ERR_raise(ERR_LIB_DSO, ERR_R_PASSED_NULL_PARAMETER);
147 return 0;
148 }
149 if (sk_void_num(dso->meth_data) < 1)
150 return 1;
151 ptr = sk_void_pop(dso->meth_data);
152 if (ptr == NULL) {
153 ERR_raise(ERR_LIB_DSO, DSO_R_NULL_HANDLE);
154 /*
155 * Should push the value back onto the stack in case of a retry.
156 */
157 sk_void_push(dso->meth_data, ptr);
158 return 0;
159 }
160 /* For now I'm not aware of any errors associated with dlclose() */
161 dlclose(ptr);
162 return 1;
163 }
164
dlfcn_bind_func(DSO * dso,const char * symname)165 static DSO_FUNC_TYPE dlfcn_bind_func(DSO *dso, const char *symname)
166 {
167 void *ptr;
168 union {
169 DSO_FUNC_TYPE sym;
170 void *dlret;
171 } u;
172
173 if ((dso == NULL) || (symname == NULL)) {
174 ERR_raise(ERR_LIB_DSO, ERR_R_PASSED_NULL_PARAMETER);
175 return NULL;
176 }
177 if (sk_void_num(dso->meth_data) < 1) {
178 ERR_raise(ERR_LIB_DSO, DSO_R_STACK_ERROR);
179 return NULL;
180 }
181 ptr = sk_void_value(dso->meth_data, sk_void_num(dso->meth_data) - 1);
182 if (ptr == NULL) {
183 ERR_raise(ERR_LIB_DSO, DSO_R_NULL_HANDLE);
184 return NULL;
185 }
186 u.dlret = dlsym(ptr, symname);
187 if (u.dlret == NULL) {
188 ERR_raise_data(ERR_LIB_DSO, DSO_R_SYM_FAILURE,
189 "symname(%s): %s", symname, dlerror());
190 return NULL;
191 }
192 return u.sym;
193 }
194
dlfcn_merger(DSO * dso,const char * filespec1,const char * filespec2)195 static char *dlfcn_merger(DSO *dso, const char *filespec1,
196 const char *filespec2)
197 {
198 char *merged;
199
200 if (!filespec1 && !filespec2) {
201 ERR_raise(ERR_LIB_DSO, ERR_R_PASSED_NULL_PARAMETER);
202 return NULL;
203 }
204 /*
205 * If the first file specification is a rooted path, it rules. same goes
206 * if the second file specification is missing.
207 */
208 if (!filespec2 || (filespec1 != NULL && filespec1[0] == '/')) {
209 merged = OPENSSL_strdup(filespec1);
210 if (merged == NULL) {
211 ERR_raise(ERR_LIB_DSO, ERR_R_MALLOC_FAILURE);
212 return NULL;
213 }
214 }
215 /*
216 * If the first file specification is missing, the second one rules.
217 */
218 else if (!filespec1) {
219 merged = OPENSSL_strdup(filespec2);
220 if (merged == NULL) {
221 ERR_raise(ERR_LIB_DSO, ERR_R_MALLOC_FAILURE);
222 return NULL;
223 }
224 } else {
225 /*
226 * This part isn't as trivial as it looks. It assumes that the
227 * second file specification really is a directory, and makes no
228 * checks whatsoever. Therefore, the result becomes the
229 * concatenation of filespec2 followed by a slash followed by
230 * filespec1.
231 */
232 int spec2len, len;
233
234 spec2len = strlen(filespec2);
235 len = spec2len + strlen(filespec1);
236
237 if (spec2len && filespec2[spec2len - 1] == '/') {
238 spec2len--;
239 len--;
240 }
241 merged = OPENSSL_malloc(len + 2);
242 if (merged == NULL) {
243 ERR_raise(ERR_LIB_DSO, ERR_R_MALLOC_FAILURE);
244 return NULL;
245 }
246 strcpy(merged, filespec2);
247 merged[spec2len] = '/';
248 strcpy(&merged[spec2len + 1], filespec1);
249 }
250 return merged;
251 }
252
dlfcn_name_converter(DSO * dso,const char * filename)253 static char *dlfcn_name_converter(DSO *dso, const char *filename)
254 {
255 char *translated;
256 int len, rsize, transform;
257
258 len = strlen(filename);
259 rsize = len + 1;
260 transform = (strstr(filename, "/") == NULL);
261 if (transform) {
262 /* We will convert this to "%s.so" or "lib%s.so" etc */
263 rsize += strlen(DSO_EXTENSION); /* The length of ".so" */
264 if ((DSO_flags(dso) & DSO_FLAG_NAME_TRANSLATION_EXT_ONLY) == 0)
265 rsize += 3; /* The length of "lib" */
266 }
267 translated = OPENSSL_malloc(rsize);
268 if (translated == NULL) {
269 ERR_raise(ERR_LIB_DSO, DSO_R_NAME_TRANSLATION_FAILED);
270 return NULL;
271 }
272 if (transform) {
273 if ((DSO_flags(dso) & DSO_FLAG_NAME_TRANSLATION_EXT_ONLY) == 0)
274 BIO_snprintf(translated, rsize, "lib%s" DSO_EXTENSION, filename);
275 else
276 BIO_snprintf(translated, rsize, "%s" DSO_EXTENSION, filename);
277 } else {
278 BIO_snprintf(translated, rsize, "%s", filename);
279 }
280 return translated;
281 }
282
283 # ifdef __sgi
284 /*-
285 This is a quote from IRIX manual for dladdr(3c):
286
287 <dlfcn.h> does not contain a prototype for dladdr or definition of
288 Dl_info. The #include <dlfcn.h> in the SYNOPSIS line is traditional,
289 but contains no dladdr prototype and no IRIX library contains an
290 implementation. Write your own declaration based on the code below.
291
292 The following code is dependent on internal interfaces that are not
293 part of the IRIX compatibility guarantee; however, there is no future
294 intention to change this interface, so on a practical level, the code
295 below is safe to use on IRIX.
296 */
297 # include <rld_interface.h>
298 # ifndef _RLD_INTERFACE_DLFCN_H_DLADDR
299 # define _RLD_INTERFACE_DLFCN_H_DLADDR
300 typedef struct Dl_info {
301 const char *dli_fname;
302 void *dli_fbase;
303 const char *dli_sname;
304 void *dli_saddr;
305 int dli_version;
306 int dli_reserved1;
307 long dli_reserved[4];
308 } Dl_info;
309 # else
310 typedef struct Dl_info Dl_info;
311 # endif
312 # define _RLD_DLADDR 14
313
dladdr(void * address,Dl_info * dl)314 static int dladdr(void *address, Dl_info *dl)
315 {
316 void *v;
317 v = _rld_new_interface(_RLD_DLADDR, address, dl);
318 return (int)v;
319 }
320 # endif /* __sgi */
321
322 # ifdef _AIX
323 /*-
324 * See IBM's AIX Version 7.2, Technical Reference:
325 * Base Operating System and Extensions, Volume 1 and 2
326 * https://www.ibm.com/support/knowledgecenter/ssw_aix_72/com.ibm.aix.base/technicalreferences.htm
327 */
328 # include <sys/ldr.h>
329 # include <errno.h>
330 /* ~ 64 * (sizeof(struct ld_info) + _XOPEN_PATH_MAX + _XOPEN_NAME_MAX) */
331 # define DLFCN_LDINFO_SIZE 86976
332 typedef struct Dl_info {
333 const char *dli_fname;
334 } Dl_info;
335 /*
336 * This dladdr()-implementation will also find the ptrgl (Pointer Glue) virtual
337 * address of a function, which is just located in the DATA segment instead of
338 * the TEXT segment.
339 */
dladdr(void * ptr,Dl_info * dl)340 static int dladdr(void *ptr, Dl_info *dl)
341 {
342 uintptr_t addr = (uintptr_t)ptr;
343 unsigned int found = 0;
344 struct ld_info *ldinfos, *next_ldi, *this_ldi;
345
346 if ((ldinfos = OPENSSL_malloc(DLFCN_LDINFO_SIZE)) == NULL) {
347 errno = ENOMEM;
348 dl->dli_fname = NULL;
349 return 0;
350 }
351
352 if ((loadquery(L_GETINFO, (void *)ldinfos, DLFCN_LDINFO_SIZE)) < 0) {
353 /*-
354 * Error handling is done through errno and dlerror() reading errno:
355 * ENOMEM (ldinfos buffer is too small),
356 * EINVAL (invalid flags),
357 * EFAULT (invalid ldinfos ptr)
358 */
359 OPENSSL_free((void *)ldinfos);
360 dl->dli_fname = NULL;
361 return 0;
362 }
363 next_ldi = ldinfos;
364
365 do {
366 this_ldi = next_ldi;
367 if (((addr >= (uintptr_t)this_ldi->ldinfo_textorg)
368 && (addr < ((uintptr_t)this_ldi->ldinfo_textorg +
369 this_ldi->ldinfo_textsize)))
370 || ((addr >= (uintptr_t)this_ldi->ldinfo_dataorg)
371 && (addr < ((uintptr_t)this_ldi->ldinfo_dataorg +
372 this_ldi->ldinfo_datasize)))) {
373 char *buffer, *member;
374 size_t buffer_sz, member_len;
375
376 buffer_sz = strlen(this_ldi->ldinfo_filename) + 1;
377 member = this_ldi->ldinfo_filename + buffer_sz;
378 if ((member_len = strlen(member)) > 0)
379 buffer_sz += 1 + member_len + 1;
380 found = 1;
381 if ((buffer = OPENSSL_malloc(buffer_sz)) != NULL) {
382 OPENSSL_strlcpy(buffer, this_ldi->ldinfo_filename, buffer_sz);
383 if (member_len > 0) {
384 /*
385 * Need to respect a possible member name and not just
386 * returning the path name in this case. See docs:
387 * sys/ldr.h, loadquery() and dlopen()/RTLD_MEMBER.
388 */
389 OPENSSL_strlcat(buffer, "(", buffer_sz);
390 OPENSSL_strlcat(buffer, member, buffer_sz);
391 OPENSSL_strlcat(buffer, ")", buffer_sz);
392 }
393 dl->dli_fname = buffer;
394 } else {
395 errno = ENOMEM;
396 }
397 } else {
398 next_ldi = (struct ld_info *)((uintptr_t)this_ldi +
399 this_ldi->ldinfo_next);
400 }
401 } while (this_ldi->ldinfo_next && !found);
402 OPENSSL_free((void *)ldinfos);
403 return (found && dl->dli_fname != NULL);
404 }
405 # endif /* _AIX */
406
dlfcn_pathbyaddr(void * addr,char * path,int sz)407 static int dlfcn_pathbyaddr(void *addr, char *path, int sz)
408 {
409 # ifdef HAVE_DLINFO
410 Dl_info dli;
411 int len;
412
413 if (addr == NULL) {
414 union {
415 int (*f) (void *, char *, int);
416 void *p;
417 } t = {
418 dlfcn_pathbyaddr
419 };
420 addr = t.p;
421 }
422
423 if (dladdr(addr, &dli)) {
424 len = (int)strlen(dli.dli_fname);
425 if (sz <= 0) {
426 # ifdef _AIX
427 OPENSSL_free((void *)dli.dli_fname);
428 # endif
429 return len + 1;
430 }
431 if (len >= sz)
432 len = sz - 1;
433 memcpy(path, dli.dli_fname, len);
434 path[len++] = 0;
435 # ifdef _AIX
436 OPENSSL_free((void *)dli.dli_fname);
437 # endif
438 return len;
439 }
440
441 ERR_add_error_data(2, "dlfcn_pathbyaddr(): ", dlerror());
442 # endif
443 return -1;
444 }
445
dlfcn_globallookup(const char * name)446 static void *dlfcn_globallookup(const char *name)
447 {
448 void *ret = NULL, *handle = dlopen(NULL, RTLD_LAZY);
449
450 if (handle) {
451 ret = dlsym(handle, name);
452 dlclose(handle);
453 }
454
455 return ret;
456 }
457 #endif /* DSO_DLFCN */
458