1 /*
2 * Copyright (c) 2006 - 2007 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include "krb5_locl.h"
35
36 #ifdef HAVE_DLFCN_H
37 #include <dlfcn.h>
38 #endif
39 #include <dirent.h>
40
41 struct krb5_plugin {
42 void *symbol;
43 struct krb5_plugin *next;
44 };
45
46 struct plugin {
47 enum { DSO, SYMBOL } type;
48 union {
49 struct {
50 char *path;
51 void *dsohandle;
52 } dso;
53 struct {
54 enum krb5_plugin_type type;
55 char *name;
56 char *symbol;
57 } symbol;
58 } u;
59 struct plugin *next;
60 };
61
62 static HEIMDAL_MUTEX plugin_mutex = HEIMDAL_MUTEX_INITIALIZER;
63 static struct plugin *registered = NULL;
64 static int plugins_needs_scan = 1;
65
66 static const char *sysplugin_dirs[] = {
67 LIBDIR "/plugin/krb5",
68 #ifdef __APPLE__
69 "/System/Library/KerberosPlugins/KerberosFrameworkPlugins",
70 #endif
71 NULL
72 };
73
74 /*
75 *
76 */
77
78 void *
_krb5_plugin_get_symbol(struct krb5_plugin * p)79 _krb5_plugin_get_symbol(struct krb5_plugin *p)
80 {
81 return p->symbol;
82 }
83
84 struct krb5_plugin *
_krb5_plugin_get_next(struct krb5_plugin * p)85 _krb5_plugin_get_next(struct krb5_plugin *p)
86 {
87 return p->next;
88 }
89
90 /*
91 *
92 */
93
94 #ifdef HAVE_DLOPEN
95
96 static krb5_error_code
loadlib(krb5_context context,char * path)97 loadlib(krb5_context context, char *path)
98 {
99 struct plugin *e;
100
101 e = calloc(1, sizeof(*e));
102 if (e == NULL) {
103 krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
104 free(path);
105 return ENOMEM;
106 }
107
108 #ifndef RTLD_LAZY
109 #define RTLD_LAZY 0
110 #endif
111 #ifndef RTLD_LOCAL
112 #define RTLD_LOCAL 0
113 #endif
114 e->type = DSO;
115 /* ignore error from dlopen, and just keep it as negative cache entry */
116 e->u.dso.dsohandle = dlopen(path, RTLD_LOCAL|RTLD_LAZY);
117 e->u.dso.path = path;
118
119 e->next = registered;
120 registered = e;
121
122 return 0;
123 }
124 #endif /* HAVE_DLOPEN */
125
126 /**
127 * Register a plugin symbol name of specific type.
128 * @param context a Keberos context
129 * @param type type of plugin symbol
130 * @param name name of plugin symbol
131 * @param symbol a pointer to the named symbol
132 * @return In case of error a non zero error com_err error is returned
133 * and the Kerberos error string is set.
134 *
135 * @ingroup krb5_support
136 */
137
138 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_plugin_register(krb5_context context,enum krb5_plugin_type type,const char * name,void * symbol)139 krb5_plugin_register(krb5_context context,
140 enum krb5_plugin_type type,
141 const char *name,
142 void *symbol)
143 {
144 struct plugin *e;
145
146 HEIMDAL_MUTEX_lock(&plugin_mutex);
147
148 /* check for duplicates */
149 for (e = registered; e != NULL; e = e->next) {
150 if (e->type == SYMBOL &&
151 strcmp(e->u.symbol.name, name) == 0 &&
152 e->u.symbol.type == type && e->u.symbol.symbol == symbol) {
153 HEIMDAL_MUTEX_unlock(&plugin_mutex);
154 return 0;
155 }
156 }
157
158 e = calloc(1, sizeof(*e));
159 if (e == NULL) {
160 HEIMDAL_MUTEX_unlock(&plugin_mutex);
161 krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
162 return ENOMEM;
163 }
164 e->type = SYMBOL;
165 e->u.symbol.type = type;
166 e->u.symbol.name = strdup(name);
167 if (e->u.symbol.name == NULL) {
168 HEIMDAL_MUTEX_unlock(&plugin_mutex);
169 free(e);
170 krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
171 return ENOMEM;
172 }
173 e->u.symbol.symbol = symbol;
174
175 e->next = registered;
176 registered = e;
177 HEIMDAL_MUTEX_unlock(&plugin_mutex);
178
179 return 0;
180 }
181
182 static int
is_valid_plugin_filename(const char * n)183 is_valid_plugin_filename(const char * n)
184 {
185 if (n[0] == '.' && (n[1] == '\0' || (n[1] == '.' && n[2] == '\0')))
186 return 0;
187
188 #ifdef _WIN32
189 /* On Windows, we only attempt to load .dll files as plug-ins. */
190 {
191 const char * ext;
192
193 ext = strrchr(n, '.');
194 if (ext == NULL)
195 return 0;
196
197 return !stricmp(ext, ".dll");
198 }
199 #else
200 return 1;
201 #endif
202 }
203
204 static void
trim_trailing_slash(char * path)205 trim_trailing_slash(char * path)
206 {
207 size_t l;
208
209 l = strlen(path);
210 while (l > 0 && (path[l - 1] == '/'
211 #ifdef BACKSLASH_PATH_DELIM
212 || path[l - 1] == '\\'
213 #endif
214 )) {
215 path[--l] = '\0';
216 }
217 }
218
219 static krb5_error_code
load_plugins(krb5_context context)220 load_plugins(krb5_context context)
221 {
222 struct plugin *e;
223 krb5_error_code ret;
224 char **dirs = NULL, **di;
225 struct dirent *entry;
226 char *path;
227 DIR *d = NULL;
228
229 if (!plugins_needs_scan)
230 return 0;
231 plugins_needs_scan = 0;
232
233 #ifdef HAVE_DLOPEN
234
235 dirs = krb5_config_get_strings(context, NULL, "libdefaults",
236 "plugin_dir", NULL);
237 if (dirs == NULL)
238 dirs = rk_UNCONST(sysplugin_dirs);
239
240 for (di = dirs; *di != NULL; di++) {
241 char * dir = *di;
242
243 #ifdef KRB5_USE_PATH_TOKENS
244 if (_krb5_expand_path_tokens(context, *di, &dir))
245 goto next_dir;
246 #endif
247
248 trim_trailing_slash(dir);
249
250 d = opendir(dir);
251
252 if (d == NULL)
253 goto next_dir;
254
255 rk_cloexec_dir(d);
256
257 while ((entry = readdir(d)) != NULL) {
258 char *n = entry->d_name;
259
260 /* skip . and .. */
261 if (!is_valid_plugin_filename(n))
262 continue;
263
264 path = NULL;
265 ret = 0;
266 #ifdef __APPLE__
267 { /* support loading bundles on MacOS */
268 size_t len = strlen(n);
269 if (len > 7 && strcmp(&n[len - 7], ".bundle") == 0)
270 ret = asprintf(&path, "%s/%s/Contents/MacOS/%.*s", dir, n, (int)(len - 7), n);
271 }
272 #endif
273 if (ret < 0 || path == NULL)
274 ret = asprintf(&path, "%s/%s", dir, n);
275
276 if (ret < 0 || path == NULL) {
277 ret = ENOMEM;
278 krb5_set_error_message(context, ret, "malloc: out of memory");
279 return ret;
280 }
281
282 /* check if already tried */
283 for (e = registered; e != NULL; e = e->next)
284 if (e->type == DSO && strcmp(e->u.dso.path, path) == 0)
285 break;
286 if (e) {
287 free(path);
288 } else {
289 loadlib(context, path); /* store or frees path */
290 }
291 }
292 closedir(d);
293
294 next_dir:
295 if (dir != *di)
296 free(dir);
297 }
298 if (dirs != rk_UNCONST(sysplugin_dirs))
299 krb5_config_free_strings(dirs);
300 #endif /* HAVE_DLOPEN */
301 return 0;
302 }
303
304 static krb5_error_code
add_symbol(krb5_context context,struct krb5_plugin ** list,void * symbol)305 add_symbol(krb5_context context, struct krb5_plugin **list, void *symbol)
306 {
307 struct krb5_plugin *e;
308
309 e = calloc(1, sizeof(*e));
310 if (e == NULL) {
311 krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
312 return ENOMEM;
313 }
314 e->symbol = symbol;
315 e->next = *list;
316 *list = e;
317 return 0;
318 }
319
320 krb5_error_code
_krb5_plugin_find(krb5_context context,enum krb5_plugin_type type,const char * name,struct krb5_plugin ** list)321 _krb5_plugin_find(krb5_context context,
322 enum krb5_plugin_type type,
323 const char *name,
324 struct krb5_plugin **list)
325 {
326 struct plugin *e;
327 krb5_error_code ret;
328
329 *list = NULL;
330
331 HEIMDAL_MUTEX_lock(&plugin_mutex);
332
333 load_plugins(context);
334
335 for (ret = 0, e = registered; e != NULL; e = e->next) {
336 switch(e->type) {
337 case DSO: {
338 void *sym;
339 if (e->u.dso.dsohandle == NULL)
340 continue;
341 sym = dlsym(e->u.dso.dsohandle, name);
342 if (sym)
343 ret = add_symbol(context, list, sym);
344 break;
345 }
346 case SYMBOL:
347 if (strcmp(e->u.symbol.name, name) == 0 && e->u.symbol.type == type)
348 ret = add_symbol(context, list, e->u.symbol.symbol);
349 break;
350 }
351 if (ret) {
352 _krb5_plugin_free(*list);
353 *list = NULL;
354 }
355 }
356
357 HEIMDAL_MUTEX_unlock(&plugin_mutex);
358 if (ret)
359 return ret;
360
361 if (*list == NULL) {
362 krb5_set_error_message(context, ENOENT, "Did not find a plugin for %s", name);
363 return ENOENT;
364 }
365
366 return 0;
367 }
368
369 void
_krb5_plugin_free(struct krb5_plugin * list)370 _krb5_plugin_free(struct krb5_plugin *list)
371 {
372 struct krb5_plugin *next;
373 while (list) {
374 next = list->next;
375 free(list);
376 list = next;
377 }
378 }
379 /*
380 * module - dict of {
381 * ModuleName = [
382 * plugin = object{
383 * array = { ptr, ctx }
384 * }
385 * ]
386 * }
387 */
388
389 static heim_dict_t modules;
390
391 struct plugin2 {
392 heim_string_t path;
393 void *dsohandle;
394 heim_dict_t names;
395 };
396
397 static void
plug_dealloc(void * ptr)398 plug_dealloc(void *ptr)
399 {
400 struct plugin2 *p = ptr;
401 heim_release(p->path);
402 heim_release(p->names);
403 if (p->dsohandle)
404 dlclose(p->dsohandle);
405 }
406
407
408 void
_krb5_load_plugins(krb5_context context,const char * name,const char ** paths)409 _krb5_load_plugins(krb5_context context, const char *name, const char **paths)
410 {
411 #ifdef HAVE_DLOPEN
412 heim_string_t s = heim_string_create(name);
413 heim_dict_t module;
414 struct dirent *entry;
415 krb5_error_code ret;
416 const char **di;
417 DIR *d;
418
419 HEIMDAL_MUTEX_lock(&plugin_mutex);
420
421 if (modules == NULL) {
422 modules = heim_dict_create(11);
423 if (modules == NULL) {
424 HEIMDAL_MUTEX_unlock(&plugin_mutex);
425 return;
426 }
427 }
428
429 module = heim_dict_copy_value(modules, s);
430 if (module == NULL) {
431 module = heim_dict_create(11);
432 if (module == NULL) {
433 HEIMDAL_MUTEX_unlock(&plugin_mutex);
434 heim_release(s);
435 return;
436 }
437 heim_dict_add_value(modules, s, module);
438 }
439 heim_release(s);
440
441 for (di = paths; *di != NULL; di++) {
442 d = opendir(*di);
443 if (d == NULL)
444 continue;
445 rk_cloexec_dir(d);
446
447 while ((entry = readdir(d)) != NULL) {
448 char *n = entry->d_name;
449 char *path = NULL;
450 heim_string_t spath;
451 struct plugin2 *p;
452
453 /* skip . and .. */
454 if (n[0] == '.' && (n[1] == '\0' || (n[1] == '.' && n[2] == '\0')))
455 continue;
456
457 ret = 0;
458 #ifdef __APPLE__
459 { /* support loading bundles on MacOS */
460 size_t len = strlen(n);
461 if (len > 7 && strcmp(&n[len - 7], ".bundle") == 0)
462 ret = asprintf(&path, "%s/%s/Contents/MacOS/%.*s", *di, n, (int)(len - 7), n);
463 }
464 #endif
465 if (ret < 0 || path == NULL)
466 ret = asprintf(&path, "%s/%s", *di, n);
467
468 if (ret < 0 || path == NULL)
469 continue;
470
471 spath = heim_string_create(n);
472 if (spath == NULL) {
473 free(path);
474 continue;
475 }
476
477 /* check if already cached */
478 p = heim_dict_copy_value(module, spath);
479 if (p == NULL) {
480 p = heim_alloc(sizeof(*p), "krb5-plugin", plug_dealloc);
481 if (p)
482 p->dsohandle = dlopen(path, RTLD_LOCAL|RTLD_LAZY);
483
484 if (p->dsohandle) {
485 p->path = heim_retain(spath);
486 p->names = heim_dict_create(11);
487 heim_dict_add_value(module, spath, p);
488 }
489 }
490 heim_release(spath);
491 heim_release(p);
492 free(path);
493 }
494 closedir(d);
495 }
496 heim_release(module);
497 HEIMDAL_MUTEX_unlock(&plugin_mutex);
498 #endif /* HAVE_DLOPEN */
499 }
500
501 void
_krb5_unload_plugins(krb5_context context,const char * name)502 _krb5_unload_plugins(krb5_context context, const char *name)
503 {
504 HEIMDAL_MUTEX_lock(&plugin_mutex);
505 heim_release(modules);
506 modules = NULL;
507 HEIMDAL_MUTEX_unlock(&plugin_mutex);
508 }
509
510 /*
511 *
512 */
513
514 struct common_plugin_method {
515 int version;
516 krb5_error_code (*init)(krb5_context, void **);
517 void (*fini)(void *);
518 };
519
520 struct plug {
521 void *dataptr;
522 void *ctx;
523 };
524
525 static void
plug_free(void * ptr)526 plug_free(void *ptr)
527 {
528 struct plug *pl = ptr;
529 if (pl->dataptr) {
530 struct common_plugin_method *cpm = pl->dataptr;
531 cpm->fini(pl->ctx);
532 }
533 }
534
535 struct iter_ctx {
536 krb5_context context;
537 heim_string_t n;
538 const char *name;
539 int min_version;
540 heim_array_t result;
541 krb5_error_code (*func)(krb5_context, const void *, void *, void *);
542 void *userctx;
543 krb5_error_code ret;
544 };
545
546 static void
search_modules(void * ctx,heim_object_t key,heim_object_t value)547 search_modules(void *ctx, heim_object_t key, heim_object_t value)
548 {
549 struct iter_ctx *s = ctx;
550 struct plugin2 *p = value;
551 struct plug *pl = heim_dict_copy_value(p->names, s->n);
552 struct common_plugin_method *cpm;
553
554 if (pl == NULL) {
555 if (p->dsohandle == NULL)
556 return;
557
558 pl = heim_alloc(sizeof(*pl), "struct-plug", plug_free);
559
560 cpm = pl->dataptr = dlsym(p->dsohandle, s->name);
561 if (cpm) {
562 int ret;
563
564 ret = cpm->init(s->context, &pl->ctx);
565 if (ret)
566 cpm = pl->dataptr = NULL;
567 }
568 heim_dict_add_value(p->names, s->n, pl);
569 } else {
570 cpm = pl->dataptr;
571 }
572
573 if (cpm && cpm->version >= s->min_version)
574 heim_array_append_value(s->result, pl);
575
576 heim_release(pl);
577 }
578
579 static void
eval_results(heim_object_t value,void * ctx)580 eval_results(heim_object_t value, void *ctx)
581 {
582 struct plug *pl = value;
583 struct iter_ctx *s = ctx;
584
585 if (s->ret != KRB5_PLUGIN_NO_HANDLE)
586 return;
587
588 s->ret = s->func(s->context, pl->dataptr, pl->ctx, s->userctx);
589 }
590
591 krb5_error_code
_krb5_plugin_run_f(krb5_context context,const char * module,const char * name,int min_version,int flags,void * userctx,krb5_error_code (* func)(krb5_context,const void *,void *,void *))592 _krb5_plugin_run_f(krb5_context context,
593 const char *module,
594 const char *name,
595 int min_version,
596 int flags,
597 void *userctx,
598 krb5_error_code (*func)(krb5_context, const void *, void *, void *))
599 {
600 heim_string_t m = heim_string_create(module);
601 heim_dict_t dict;
602 struct iter_ctx s;
603
604 HEIMDAL_MUTEX_lock(&plugin_mutex);
605
606 dict = heim_dict_copy_value(modules, m);
607 heim_release(m);
608 if (dict == NULL) {
609 HEIMDAL_MUTEX_unlock(&plugin_mutex);
610 return KRB5_PLUGIN_NO_HANDLE;
611 }
612
613 s.context = context;
614 s.name = name;
615 s.n = heim_string_create(name);
616 s.min_version = min_version;
617 s.result = heim_array_create();
618 s.func = func;
619 s.userctx = userctx;
620
621 heim_dict_iterate_f(dict, search_modules, &s);
622
623 heim_release(dict);
624
625 HEIMDAL_MUTEX_unlock(&plugin_mutex);
626
627 s.ret = KRB5_PLUGIN_NO_HANDLE;
628
629 heim_array_iterate_f(s.result, eval_results, &s);
630
631 heim_release(s.result);
632 heim_release(s.n);
633
634 return s.ret;
635 }
636