1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 1998 Michael Smith
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 /*
30 * The unified bootloader passes us a pointer to a preserved copy of
31 * bootstrap/kernel environment variables. We convert them to a
32 * dynamic array of strings later when the VM subsystem is up.
33 *
34 * We make these available through the kenv(2) syscall for userland
35 * and through kern_getenv()/freeenv() kern_setenv() kern_unsetenv() testenv() for
36 * the kernel.
37 */
38
39 #include <sys/param.h>
40 #include <sys/eventhandler.h>
41 #include <sys/systm.h>
42 #include <sys/kenv.h>
43 #include <sys/kernel.h>
44 #include <sys/libkern.h>
45 #include <sys/limits.h>
46 #include <sys/lock.h>
47 #include <sys/malloc.h>
48 #include <sys/mutex.h>
49 #include <sys/priv.h>
50 #include <sys/proc.h>
51 #include <sys/queue.h>
52 #include <sys/sysent.h>
53 #include <sys/sysproto.h>
54
55 #include <security/mac/mac_framework.h>
56
57 #include <vm/uma.h>
58
59 static char *_getenv_dynamic_locked(const char *name, int *idx);
60 static char *_getenv_dynamic(const char *name, int *idx);
61
62 static char *kenv_acquire(const char *name);
63 static void kenv_release(const char *buf);
64
65 static MALLOC_DEFINE(M_KENV, "kenv", "kernel environment");
66
67 #define KENV_SIZE 512 /* Maximum number of environment strings */
68
69 static uma_zone_t kenv_zone;
70 static int kenv_mvallen = KENV_MVALLEN;
71
72 /* pointer to the config-generated static environment */
73 char *kern_envp;
74
75 /* pointer to the md-static environment */
76 char *md_envp;
77 static int md_env_len;
78 static int md_env_pos;
79
80 static char *kernenv_next(char *);
81
82 /* dynamic environment variables */
83 char **kenvp;
84 struct mtx kenv_lock;
85
86 /*
87 * No need to protect this with a mutex since SYSINITS are single threaded.
88 */
89 bool dynamic_kenv;
90
91 #define KENV_CHECK if (!dynamic_kenv) \
92 panic("%s: called before SI_SUB_KMEM", __func__)
93
94 static int
kenv_dump(struct thread * td,char ** envp,int what,char * value,int len)95 kenv_dump(struct thread *td, char **envp, int what, char *value, int len)
96 {
97 char *buffer, *senv;
98 size_t done, needed, buflen;
99 int error;
100
101 error = 0;
102 buffer = NULL;
103 done = needed = 0;
104
105 MPASS(what == KENV_DUMP || what == KENV_DUMP_LOADER ||
106 what == KENV_DUMP_STATIC);
107
108 /*
109 * For non-dynamic kernel environment, we pass in either md_envp or
110 * kern_envp and we must traverse with kernenv_next(). This shuffling
111 * of pointers simplifies the below loop by only differing in how envp
112 * is modified.
113 */
114 if (what != KENV_DUMP) {
115 senv = (char *)envp;
116 envp = &senv;
117 }
118
119 buflen = len;
120 if (buflen > KENV_SIZE * (KENV_MNAMELEN + kenv_mvallen + 2))
121 buflen = KENV_SIZE * (KENV_MNAMELEN +
122 kenv_mvallen + 2);
123 if (len > 0 && value != NULL)
124 buffer = malloc(buflen, M_TEMP, M_WAITOK|M_ZERO);
125
126 /* Only take the lock for the dynamic kenv. */
127 if (what == KENV_DUMP)
128 mtx_lock(&kenv_lock);
129 while (*envp != NULL) {
130 len = strlen(*envp) + 1;
131 needed += len;
132 len = min(len, buflen - done);
133 /*
134 * If called with a NULL or insufficiently large
135 * buffer, just keep computing the required size.
136 */
137 if (value != NULL && buffer != NULL && len > 0) {
138 bcopy(*envp, buffer + done, len);
139 done += len;
140 }
141
142 /* Advance the pointer depending on the kenv format. */
143 if (what == KENV_DUMP)
144 envp++;
145 else
146 senv = kernenv_next(senv);
147 }
148 if (what == KENV_DUMP)
149 mtx_unlock(&kenv_lock);
150 if (buffer != NULL) {
151 error = copyout(buffer, value, done);
152 free(buffer, M_TEMP);
153 }
154 td->td_retval[0] = ((done == needed) ? 0 : needed);
155 return (error);
156 }
157
158 int
sys_kenv(struct thread * td,struct kenv_args * uap)159 sys_kenv(struct thread *td, struct kenv_args *uap)
160 {
161 char *name, *value;
162 size_t len;
163 int error;
164
165 KASSERT(dynamic_kenv, ("kenv: dynamic_kenv = false"));
166
167 error = 0;
168
169 switch (uap->what) {
170 case KENV_DUMP:
171 #ifdef MAC
172 error = mac_kenv_check_dump(td->td_ucred);
173 if (error)
174 return (error);
175 #endif
176 return (kenv_dump(td, kenvp, uap->what, uap->value, uap->len));
177 case KENV_DUMP_LOADER:
178 case KENV_DUMP_STATIC:
179 #ifdef MAC
180 error = mac_kenv_check_dump(td->td_ucred);
181 if (error)
182 return (error);
183 #endif
184 #ifdef PRESERVE_EARLY_KENV
185 return (kenv_dump(td,
186 uap->what == KENV_DUMP_LOADER ? (char **)md_envp :
187 (char **)kern_envp, uap->what, uap->value, uap->len));
188 #else
189 return (ENOENT);
190 #endif
191 case KENV_SET:
192 error = priv_check(td, PRIV_KENV_SET);
193 if (error)
194 return (error);
195 break;
196
197 case KENV_UNSET:
198 error = priv_check(td, PRIV_KENV_UNSET);
199 if (error)
200 return (error);
201 break;
202 }
203
204 name = malloc(KENV_MNAMELEN + 1, M_TEMP, M_WAITOK);
205
206 error = copyinstr(uap->name, name, KENV_MNAMELEN + 1, NULL);
207 if (error)
208 goto done;
209
210 switch (uap->what) {
211 case KENV_GET:
212 #ifdef MAC
213 error = mac_kenv_check_get(td->td_ucred, name);
214 if (error)
215 goto done;
216 #endif
217 value = kern_getenv(name);
218 if (value == NULL) {
219 error = ENOENT;
220 goto done;
221 }
222 len = strlen(value) + 1;
223 if (len > uap->len)
224 len = uap->len;
225 error = copyout(value, uap->value, len);
226 freeenv(value);
227 if (error)
228 goto done;
229 td->td_retval[0] = len;
230 break;
231 case KENV_SET:
232 len = uap->len;
233 if (len < 1) {
234 error = EINVAL;
235 goto done;
236 }
237 if (len > kenv_mvallen + 1)
238 len = kenv_mvallen + 1;
239 value = malloc(len, M_TEMP, M_WAITOK);
240 error = copyinstr(uap->value, value, len, NULL);
241 if (error) {
242 free(value, M_TEMP);
243 goto done;
244 }
245 #ifdef MAC
246 error = mac_kenv_check_set(td->td_ucred, name, value);
247 if (error == 0)
248 #endif
249 kern_setenv(name, value);
250 free(value, M_TEMP);
251 break;
252 case KENV_UNSET:
253 #ifdef MAC
254 error = mac_kenv_check_unset(td->td_ucred, name);
255 if (error)
256 goto done;
257 #endif
258 error = kern_unsetenv(name);
259 if (error)
260 error = ENOENT;
261 break;
262 default:
263 error = EINVAL;
264 break;
265 }
266 done:
267 free(name, M_TEMP);
268 return (error);
269 }
270
271 /*
272 * Populate the initial kernel environment.
273 *
274 * This is called very early in MD startup, either to provide a copy of the
275 * environment obtained from a boot loader, or to provide an empty buffer into
276 * which MD code can store an initial environment using kern_setenv() calls.
277 *
278 * kern_envp is set to the static_env generated by config(8). This implements
279 * the env keyword described in config(5).
280 *
281 * If len is non-zero, the caller is providing an empty buffer. The caller will
282 * subsequently use kern_setenv() to add up to len bytes of initial environment
283 * before the dynamic environment is available.
284 *
285 * If len is zero, the caller is providing a pre-loaded buffer containing
286 * environment strings. Additional strings cannot be added until the dynamic
287 * environment is available. The memory pointed to must remain stable at least
288 * until sysinit runs init_dynamic_kenv() and preferably until after SI_SUB_KMEM
289 * is finished so that subr_hints routines may continue to use it until the
290 * environments have been fully merged at the end of the pass. If no initial
291 * environment is available from the boot loader, passing a NULL pointer allows
292 * the static_env to be installed if it is configured. In this case, any call
293 * to kern_setenv() prior to the setup of the dynamic environment will result in
294 * a panic.
295 */
296 void
init_static_kenv(char * buf,size_t len)297 init_static_kenv(char *buf, size_t len)
298 {
299
300 KASSERT(!dynamic_kenv, ("kenv: dynamic_kenv already initialized"));
301 /*
302 * Suitably sized means it must be able to hold at least one empty
303 * variable, otherwise things go belly up if a kern_getenv call is
304 * made without a prior call to kern_setenv as we have a malformed
305 * environment.
306 */
307 KASSERT(len == 0 || len >= 2,
308 ("kenv: static env must be initialized or suitably sized"));
309 KASSERT(len == 0 || (*buf == '\0' && *(buf + 1) == '\0'),
310 ("kenv: sized buffer must be initially empty"));
311
312 /*
313 * We may be called twice, with the second call needed to relocate
314 * md_envp after enabling paging. md_envp is then garbage if it is
315 * not null and the relocation will move it. Discard it so as to
316 * not crash using its old value in our first call to kern_getenv().
317 *
318 * The second call gives the same environment as the first except
319 * in silly configurations where the static env disables itself.
320 *
321 * Other env calls don't handle possibly-garbage pointers, so must
322 * not be made between enabling paging and calling here.
323 */
324 md_envp = NULL;
325 md_env_len = 0;
326 md_env_pos = 0;
327
328 /*
329 * Give the static environment a chance to disable the loader(8)
330 * environment first. This is done with loader_env.disabled=1.
331 *
332 * static_env and static_hints may both be disabled, but in slightly
333 * different ways. For static_env, we just don't setup kern_envp and
334 * it's as if a static env wasn't even provided. For static_hints,
335 * we effectively zero out the buffer to stop the rest of the kernel
336 * from being able to use it.
337 *
338 * We're intentionally setting this up so that static_hints.disabled may
339 * be specified in either the MD env or the static env. This keeps us
340 * consistent in our new world view.
341 *
342 * As a warning, the static environment may not be disabled in any way
343 * if the static environment has disabled the loader environment.
344 */
345 kern_envp = static_env;
346 if (!getenv_is_true("loader_env.disabled")) {
347 md_envp = buf;
348 md_env_len = len;
349 md_env_pos = 0;
350
351 if (getenv_is_true("static_env.disabled")) {
352 kern_envp[0] = '\0';
353 kern_envp[1] = '\0';
354 }
355 }
356 if (getenv_is_true("static_hints.disabled")) {
357 static_hints[0] = '\0';
358 static_hints[1] = '\0';
359 }
360 }
361
362 /* Maximum suffix number appended for duplicate environment variable names. */
363 #define MAXSUFFIX 9999
364 #define SUFFIXLEN strlen("_" __XSTRING(MAXSUFFIX))
365
366 static void
getfreesuffix(char * cp,size_t * n)367 getfreesuffix(char *cp, size_t *n)
368 {
369 size_t len = strlen(cp);
370 char * ncp;
371
372 ncp = malloc(len + SUFFIXLEN + 1, M_KENV, M_WAITOK);
373 memcpy(ncp, cp, len);
374 for (*n = 1; *n <= MAXSUFFIX; (*n)++) {
375 sprintf(&ncp[len], "_%zu", *n);
376 if (!_getenv_dynamic_locked(ncp, NULL))
377 break;
378 }
379 free(ncp, M_KENV);
380 if (*n > MAXSUFFIX)
381 panic("Too many duplicate kernel environment values: %s", cp);
382 }
383
384 static void
init_dynamic_kenv_from(char * init_env,int * curpos)385 init_dynamic_kenv_from(char *init_env, int *curpos)
386 {
387 char *cp, *cpnext, *eqpos, *found;
388 size_t len, n;
389 int i;
390
391 if (init_env && *init_env != '\0') {
392 found = NULL;
393 i = *curpos;
394 for (cp = init_env; cp != NULL; cp = cpnext) {
395 cpnext = kernenv_next(cp);
396 len = strlen(cp) + 1;
397 if (i > KENV_SIZE) {
398 printf(
399 "WARNING: too many kenv strings, ignoring %s\n",
400 cp);
401 goto sanitize;
402 }
403 if (len > KENV_MNAMELEN + 1 + kenv_mvallen + 1) {
404 printf(
405 "WARNING: too long kenv string, ignoring %s\n",
406 cp);
407 goto sanitize;
408 }
409 eqpos = strchr(cp, '=');
410 if (eqpos == NULL) {
411 printf(
412 "WARNING: malformed static env value, ignoring %s\n",
413 cp);
414 goto sanitize;
415 }
416 *eqpos = 0;
417 /*
418 * Handle duplicates in the environment as we go; we
419 * add the duplicated assignments with _N suffixes.
420 * This ensures that (a) if a variable is set in the
421 * static environment and in the "loader" environment
422 * provided by MD code, the value from the loader will
423 * have the expected variable name and the value from
424 * the static environment will have the suffix; and (b)
425 * if the "loader" environment has the same variable
426 * set multiple times (as is possible with values being
427 * passed via the kernel "command line") the extra
428 * values are visible to code which knows where to look
429 * for them.
430 */
431 found = _getenv_dynamic_locked(cp, NULL);
432 if (found != NULL) {
433 getfreesuffix(cp, &n);
434 kenvp[i] = malloc(len + SUFFIXLEN,
435 M_KENV, M_WAITOK);
436 sprintf(kenvp[i++], "%s_%zu=%s", cp, n,
437 &eqpos[1]);
438 } else {
439 kenvp[i] = malloc(len, M_KENV, M_WAITOK);
440 *eqpos = '=';
441 strcpy(kenvp[i++], cp);
442 }
443 sanitize:
444 #ifdef PRESERVE_EARLY_KENV
445 continue;
446 #else
447 explicit_bzero(cp, len - 1);
448 #endif
449 }
450 *curpos = i;
451 }
452 }
453
454 /*
455 * Setup the dynamic kernel environment.
456 */
457 static void
init_dynamic_kenv(void * data __unused)458 init_dynamic_kenv(void *data __unused)
459 {
460 int dynamic_envpos;
461 int size;
462
463 TUNABLE_INT_FETCH("kenv_mvallen", &kenv_mvallen);
464 size = KENV_MNAMELEN + 1 + kenv_mvallen + 1;
465
466 kenv_zone = uma_zcreate("kenv", size, NULL, NULL, NULL, NULL,
467 UMA_ALIGN_PTR, 0);
468
469 kenvp = malloc((KENV_SIZE + 1) * sizeof(char *), M_KENV,
470 M_WAITOK | M_ZERO);
471
472 dynamic_envpos = 0;
473 init_dynamic_kenv_from(md_envp, &dynamic_envpos);
474 init_dynamic_kenv_from(kern_envp, &dynamic_envpos);
475 kenvp[dynamic_envpos] = NULL;
476
477 mtx_init(&kenv_lock, "kernel environment", NULL, MTX_DEF);
478 dynamic_kenv = true;
479 }
480 SYSINIT(kenv, SI_SUB_KMEM + 1, SI_ORDER_FIRST, init_dynamic_kenv, NULL);
481
482 void
freeenv(char * env)483 freeenv(char *env)
484 {
485
486 if (dynamic_kenv && env != NULL) {
487 explicit_bzero(env, strlen(env));
488 uma_zfree(kenv_zone, env);
489 }
490 }
491
492 /*
493 * Internal functions for string lookup.
494 */
495 static char *
_getenv_dynamic_locked(const char * name,int * idx)496 _getenv_dynamic_locked(const char *name, int *idx)
497 {
498 char *cp;
499 int len, i;
500
501 len = strlen(name);
502 for (cp = kenvp[0], i = 0; cp != NULL; cp = kenvp[++i]) {
503 if ((strncmp(cp, name, len) == 0) &&
504 (cp[len] == '=')) {
505 if (idx != NULL)
506 *idx = i;
507 return (cp + len + 1);
508 }
509 }
510 return (NULL);
511 }
512
513 static char *
_getenv_dynamic(const char * name,int * idx)514 _getenv_dynamic(const char *name, int *idx)
515 {
516
517 mtx_assert(&kenv_lock, MA_OWNED);
518 return (_getenv_dynamic_locked(name, idx));
519 }
520
521 static char *
_getenv_static_from(char * chkenv,const char * name)522 _getenv_static_from(char *chkenv, const char *name)
523 {
524 char *cp, *ep;
525 int len;
526
527 for (cp = chkenv; cp != NULL; cp = kernenv_next(cp)) {
528 for (ep = cp; (*ep != '=') && (*ep != 0); ep++)
529 ;
530 if (*ep != '=')
531 continue;
532 len = ep - cp;
533 ep++;
534 if (!strncmp(name, cp, len) && name[len] == 0)
535 return (ep);
536 }
537 return (NULL);
538 }
539
540 static char *
_getenv_static(const char * name)541 _getenv_static(const char *name)
542 {
543 char *val;
544
545 val = _getenv_static_from(md_envp, name);
546 if (val != NULL)
547 return (val);
548 val = _getenv_static_from(kern_envp, name);
549 if (val != NULL)
550 return (val);
551 return (NULL);
552 }
553
554 /*
555 * Look up an environment variable by name.
556 * Return a pointer to the string if found.
557 * The pointer has to be freed with freeenv()
558 * after use.
559 */
560 char *
kern_getenv(const char * name)561 kern_getenv(const char *name)
562 {
563 char *cp, *ret;
564 int len;
565
566 if (dynamic_kenv) {
567 len = KENV_MNAMELEN + 1 + kenv_mvallen + 1;
568 ret = uma_zalloc(kenv_zone, M_WAITOK | M_ZERO);
569 mtx_lock(&kenv_lock);
570 cp = _getenv_dynamic(name, NULL);
571 if (cp != NULL)
572 strlcpy(ret, cp, len);
573 mtx_unlock(&kenv_lock);
574 if (cp == NULL) {
575 uma_zfree(kenv_zone, ret);
576 ret = NULL;
577 }
578 } else
579 ret = _getenv_static(name);
580
581 return (ret);
582 }
583
584 /*
585 * Test if an environment variable is defined.
586 */
587 int
testenv(const char * name)588 testenv(const char *name)
589 {
590 char *cp;
591
592 cp = kenv_acquire(name);
593 kenv_release(cp);
594
595 if (cp != NULL)
596 return (1);
597 return (0);
598 }
599
600 /*
601 * Set an environment variable in the MD-static environment. This cannot
602 * feasibly be done on config(8)-generated static environments as they don't
603 * generally include space for extra variables.
604 */
605 static int
setenv_static(const char * name,const char * value)606 setenv_static(const char *name, const char *value)
607 {
608 int len;
609
610 if (md_env_pos >= md_env_len)
611 return (-1);
612
613 /* Check space for x=y and two nuls */
614 len = strlen(name) + strlen(value);
615 if (len + 3 < md_env_len - md_env_pos) {
616 len = sprintf(&md_envp[md_env_pos], "%s=%s", name, value);
617 md_env_pos += len+1;
618 md_envp[md_env_pos] = '\0';
619 return (0);
620 } else
621 return (-1);
622
623 }
624
625 /*
626 * Set an environment variable by name.
627 */
628 int
kern_setenv(const char * name,const char * value)629 kern_setenv(const char *name, const char *value)
630 {
631 char *buf, *cp, *oldenv;
632 int namelen, vallen, i;
633
634 if (!dynamic_kenv && md_env_len > 0)
635 return (setenv_static(name, value));
636
637 KENV_CHECK;
638
639 namelen = strlen(name) + 1;
640 if (namelen > KENV_MNAMELEN + 1)
641 return (-1);
642 vallen = strlen(value) + 1;
643 if (vallen > kenv_mvallen + 1)
644 return (-1);
645 buf = malloc(namelen + vallen, M_KENV, M_WAITOK);
646 sprintf(buf, "%s=%s", name, value);
647
648 mtx_lock(&kenv_lock);
649 cp = _getenv_dynamic(name, &i);
650 if (cp != NULL) {
651 oldenv = kenvp[i];
652 kenvp[i] = buf;
653 mtx_unlock(&kenv_lock);
654 free(oldenv, M_KENV);
655 } else {
656 /* We add the option if it wasn't found */
657 for (i = 0; (cp = kenvp[i]) != NULL; i++)
658 ;
659
660 /* Bounds checking */
661 if (i < 0 || i >= KENV_SIZE) {
662 free(buf, M_KENV);
663 mtx_unlock(&kenv_lock);
664 return (-1);
665 }
666
667 kenvp[i] = buf;
668 kenvp[i + 1] = NULL;
669 mtx_unlock(&kenv_lock);
670 }
671 EVENTHANDLER_INVOKE(setenv, name);
672 return (0);
673 }
674
675 /*
676 * Unset an environment variable string.
677 */
678 int
kern_unsetenv(const char * name)679 kern_unsetenv(const char *name)
680 {
681 char *cp, *oldenv;
682 int i, j;
683
684 KENV_CHECK;
685
686 mtx_lock(&kenv_lock);
687 cp = _getenv_dynamic(name, &i);
688 if (cp != NULL) {
689 oldenv = kenvp[i];
690 for (j = i + 1; kenvp[j] != NULL; j++)
691 kenvp[i++] = kenvp[j];
692 kenvp[i] = NULL;
693 mtx_unlock(&kenv_lock);
694 zfree(oldenv, M_KENV);
695 EVENTHANDLER_INVOKE(unsetenv, name);
696 return (0);
697 }
698 mtx_unlock(&kenv_lock);
699 return (-1);
700 }
701
702 /*
703 * Return the internal kenv buffer for the variable name, if it exists.
704 * If the dynamic kenv is initialized and the name is present, return
705 * with kenv_lock held.
706 */
707 static char *
kenv_acquire(const char * name)708 kenv_acquire(const char *name)
709 {
710 char *value;
711
712 if (dynamic_kenv) {
713 mtx_lock(&kenv_lock);
714 value = _getenv_dynamic(name, NULL);
715 if (value == NULL)
716 mtx_unlock(&kenv_lock);
717 return (value);
718 } else
719 return (_getenv_static(name));
720 }
721
722 /*
723 * Undo a previous kenv_acquire() operation
724 */
725 static void
kenv_release(const char * buf)726 kenv_release(const char *buf)
727 {
728 if ((buf != NULL) && dynamic_kenv)
729 mtx_unlock(&kenv_lock);
730 }
731
732 /*
733 * Return a string value from an environment variable.
734 */
735 int
getenv_string(const char * name,char * data,int size)736 getenv_string(const char *name, char *data, int size)
737 {
738 char *cp;
739
740 cp = kenv_acquire(name);
741
742 if (cp != NULL)
743 strlcpy(data, cp, size);
744
745 kenv_release(cp);
746
747 return (cp != NULL);
748 }
749
750 /*
751 * Return an array of integers at the given type size and signedness.
752 */
753 int
getenv_array(const char * name,void * pdata,int size,int * psize,int type_size,bool allow_signed)754 getenv_array(const char *name, void *pdata, int size, int *psize,
755 int type_size, bool allow_signed)
756 {
757 uint8_t shift;
758 int64_t value;
759 int64_t old;
760 const char *buf;
761 char *end;
762 const char *ptr;
763 int n;
764 int rc;
765
766 rc = 0; /* assume failure */
767
768 buf = kenv_acquire(name);
769 if (buf == NULL)
770 goto error;
771
772 /* get maximum number of elements */
773 size /= type_size;
774
775 n = 0;
776
777 for (ptr = buf; *ptr != 0; ) {
778 value = strtoq(ptr, &end, 0);
779
780 /* check if signed numbers are allowed */
781 if (value < 0 && !allow_signed)
782 goto error;
783
784 /* check for invalid value */
785 if (ptr == end)
786 goto error;
787
788 /* check for valid suffix */
789 switch (*end) {
790 case 't':
791 case 'T':
792 shift = 40;
793 end++;
794 break;
795 case 'g':
796 case 'G':
797 shift = 30;
798 end++;
799 break;
800 case 'm':
801 case 'M':
802 shift = 20;
803 end++;
804 break;
805 case 'k':
806 case 'K':
807 shift = 10;
808 end++;
809 break;
810 case ' ':
811 case '\t':
812 case ',':
813 case 0:
814 shift = 0;
815 break;
816 default:
817 /* garbage after numeric value */
818 goto error;
819 }
820
821 /* skip till next value, if any */
822 while (*end == '\t' || *end == ',' || *end == ' ')
823 end++;
824
825 /* update pointer */
826 ptr = end;
827
828 /* apply shift */
829 old = value;
830 value <<= shift;
831
832 /* overflow check */
833 if ((value >> shift) != old)
834 goto error;
835
836 /* check for buffer overflow */
837 if (n >= size)
838 goto error;
839
840 /* store value according to type size */
841 switch (type_size) {
842 case 1:
843 if (allow_signed) {
844 if (value < SCHAR_MIN || value > SCHAR_MAX)
845 goto error;
846 } else {
847 if (value < 0 || value > UCHAR_MAX)
848 goto error;
849 }
850 ((uint8_t *)pdata)[n] = (uint8_t)value;
851 break;
852 case 2:
853 if (allow_signed) {
854 if (value < SHRT_MIN || value > SHRT_MAX)
855 goto error;
856 } else {
857 if (value < 0 || value > USHRT_MAX)
858 goto error;
859 }
860 ((uint16_t *)pdata)[n] = (uint16_t)value;
861 break;
862 case 4:
863 if (allow_signed) {
864 if (value < INT_MIN || value > INT_MAX)
865 goto error;
866 } else {
867 if (value > UINT_MAX)
868 goto error;
869 }
870 ((uint32_t *)pdata)[n] = (uint32_t)value;
871 break;
872 case 8:
873 ((uint64_t *)pdata)[n] = (uint64_t)value;
874 break;
875 default:
876 goto error;
877 }
878 n++;
879 }
880 *psize = n * type_size;
881
882 if (n != 0)
883 rc = 1; /* success */
884 error:
885 kenv_release(buf);
886 return (rc);
887 }
888
889 /*
890 * Return an integer value from an environment variable.
891 */
892 int
getenv_int(const char * name,int * data)893 getenv_int(const char *name, int *data)
894 {
895 quad_t tmp;
896 int rval;
897
898 rval = getenv_quad(name, &tmp);
899 if (rval)
900 *data = (int) tmp;
901 return (rval);
902 }
903
904 /*
905 * Return an unsigned integer value from an environment variable.
906 */
907 int
getenv_uint(const char * name,unsigned int * data)908 getenv_uint(const char *name, unsigned int *data)
909 {
910 quad_t tmp;
911 int rval;
912
913 rval = getenv_quad(name, &tmp);
914 if (rval)
915 *data = (unsigned int) tmp;
916 return (rval);
917 }
918
919 /*
920 * Return an int64_t value from an environment variable.
921 */
922 int
getenv_int64(const char * name,int64_t * data)923 getenv_int64(const char *name, int64_t *data)
924 {
925 quad_t tmp;
926 int64_t rval;
927
928 rval = getenv_quad(name, &tmp);
929 if (rval)
930 *data = (int64_t) tmp;
931 return (rval);
932 }
933
934 /*
935 * Return an uint64_t value from an environment variable.
936 */
937 int
getenv_uint64(const char * name,uint64_t * data)938 getenv_uint64(const char *name, uint64_t *data)
939 {
940 quad_t tmp;
941 uint64_t rval;
942
943 rval = getenv_quad(name, &tmp);
944 if (rval)
945 *data = (uint64_t) tmp;
946 return (rval);
947 }
948
949 /*
950 * Return a long value from an environment variable.
951 */
952 int
getenv_long(const char * name,long * data)953 getenv_long(const char *name, long *data)
954 {
955 quad_t tmp;
956 int rval;
957
958 rval = getenv_quad(name, &tmp);
959 if (rval)
960 *data = (long) tmp;
961 return (rval);
962 }
963
964 /*
965 * Return an unsigned long value from an environment variable.
966 */
967 int
getenv_ulong(const char * name,unsigned long * data)968 getenv_ulong(const char *name, unsigned long *data)
969 {
970 quad_t tmp;
971 int rval;
972
973 rval = getenv_quad(name, &tmp);
974 if (rval)
975 *data = (unsigned long) tmp;
976 return (rval);
977 }
978
979 /*
980 * Return a quad_t value from an environment variable.
981 */
982 int
getenv_quad(const char * name,quad_t * data)983 getenv_quad(const char *name, quad_t *data)
984 {
985 const char *value;
986 char suffix, *vtp;
987 quad_t iv;
988
989 value = kenv_acquire(name);
990 if (value == NULL) {
991 goto error;
992 }
993 iv = strtoq(value, &vtp, 0);
994 if (vtp == value || (vtp[0] != '\0' && vtp[1] != '\0')) {
995 goto error;
996 }
997 suffix = vtp[0];
998 kenv_release(value);
999 switch (suffix) {
1000 case 't': case 'T':
1001 iv *= 1024;
1002 /* FALLTHROUGH */
1003 case 'g': case 'G':
1004 iv *= 1024;
1005 /* FALLTHROUGH */
1006 case 'm': case 'M':
1007 iv *= 1024;
1008 /* FALLTHROUGH */
1009 case 'k': case 'K':
1010 iv *= 1024;
1011 case '\0':
1012 break;
1013 default:
1014 return (0);
1015 }
1016 *data = iv;
1017 return (1);
1018 error:
1019 kenv_release(value);
1020 return (0);
1021 }
1022
1023 /*
1024 * Return a boolean value from an environment variable. This can be in
1025 * numerical or string form, i.e. "1" or "true".
1026 */
1027 int
getenv_bool(const char * name,bool * data)1028 getenv_bool(const char *name, bool *data)
1029 {
1030 char *val;
1031 int ret = 0;
1032
1033 if (name == NULL)
1034 return (0);
1035
1036 val = kern_getenv(name);
1037 if (val == NULL)
1038 return (0);
1039
1040 if ((strcmp(val, "1") == 0) || (strcasecmp(val, "true") == 0)) {
1041 *data = true;
1042 ret = 1;
1043 } else if ((strcmp(val, "0") == 0) || (strcasecmp(val, "false") == 0)) {
1044 *data = false;
1045 ret = 1;
1046 } else {
1047 /* Spit out a warning for malformed boolean variables. */
1048 printf("Environment variable %s has non-boolean value \"%s\"\n",
1049 name, val);
1050 }
1051 freeenv(val);
1052
1053 return (ret);
1054 }
1055
1056 /*
1057 * Wrapper around getenv_bool to easily check for true.
1058 */
1059 bool
getenv_is_true(const char * name)1060 getenv_is_true(const char *name)
1061 {
1062 bool val;
1063
1064 if (getenv_bool(name, &val) != 0)
1065 return (val);
1066 return (false);
1067 }
1068
1069 /*
1070 * Wrapper around getenv_bool to easily check for false.
1071 */
1072 bool
getenv_is_false(const char * name)1073 getenv_is_false(const char *name)
1074 {
1075 bool val;
1076
1077 if (getenv_bool(name, &val) != 0)
1078 return (!val);
1079 return (false);
1080 }
1081
1082 /*
1083 * Find the next entry after the one which (cp) falls within, return a
1084 * pointer to its start or NULL if there are no more.
1085 */
1086 static char *
kernenv_next(char * cp)1087 kernenv_next(char *cp)
1088 {
1089
1090 if (cp != NULL) {
1091 while (*cp != 0)
1092 cp++;
1093 cp++;
1094 if (*cp == 0)
1095 cp = NULL;
1096 }
1097 return (cp);
1098 }
1099
1100 void
tunable_int_init(void * data)1101 tunable_int_init(void *data)
1102 {
1103 struct tunable_int *d = (struct tunable_int *)data;
1104
1105 TUNABLE_INT_FETCH(d->path, d->var);
1106 }
1107
1108 void
tunable_long_init(void * data)1109 tunable_long_init(void *data)
1110 {
1111 struct tunable_long *d = (struct tunable_long *)data;
1112
1113 TUNABLE_LONG_FETCH(d->path, d->var);
1114 }
1115
1116 void
tunable_ulong_init(void * data)1117 tunable_ulong_init(void *data)
1118 {
1119 struct tunable_ulong *d = (struct tunable_ulong *)data;
1120
1121 TUNABLE_ULONG_FETCH(d->path, d->var);
1122 }
1123
1124 void
tunable_int64_init(void * data)1125 tunable_int64_init(void *data)
1126 {
1127 struct tunable_int64 *d = (struct tunable_int64 *)data;
1128
1129 TUNABLE_INT64_FETCH(d->path, d->var);
1130 }
1131
1132 void
tunable_uint64_init(void * data)1133 tunable_uint64_init(void *data)
1134 {
1135 struct tunable_uint64 *d = (struct tunable_uint64 *)data;
1136
1137 TUNABLE_UINT64_FETCH(d->path, d->var);
1138 }
1139
1140 void
tunable_quad_init(void * data)1141 tunable_quad_init(void *data)
1142 {
1143 struct tunable_quad *d = (struct tunable_quad *)data;
1144
1145 TUNABLE_QUAD_FETCH(d->path, d->var);
1146 }
1147
1148 void
tunable_bool_init(void * data)1149 tunable_bool_init(void *data)
1150 {
1151 struct tunable_bool *d = (struct tunable_bool *)data;
1152
1153 TUNABLE_BOOL_FETCH(d->path, d->var);
1154 }
1155
1156 void
tunable_str_init(void * data)1157 tunable_str_init(void *data)
1158 {
1159 struct tunable_str *d = (struct tunable_str *)data;
1160
1161 TUNABLE_STR_FETCH(d->path, d->var, d->size);
1162 }
1163