2 * Copyright (c) 1998 Michael Smith
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * The unified bootloader passes us a pointer to a preserved copy of
29 * bootstrap/kernel environment variables. We convert them to a
30 * dynamic array of strings later when the VM subsystem is up.
32 * We make these available through the kenv(2) syscall for userland
33 * and through getenv()/freeenv() setenv() unsetenv() testenv() for
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
40 #include <sys/types.h>
41 #include <sys/param.h>
43 #include <sys/queue.h>
45 #include <sys/malloc.h>
46 #include <sys/mutex.h>
48 #include <sys/kernel.h>
49 #include <sys/systm.h>
50 #include <sys/sysent.h>
51 #include <sys/sysproto.h>
52 #include <sys/libkern.h>
55 #include <security/mac/mac_framework.h>
57 static MALLOC_DEFINE(M_KENV, "kenv", "kernel environment");
59 #define KENV_SIZE 512 /* Maximum number of environment strings */
61 /* pointer to the static environment */
65 static char *kernenv_next(char *);
67 /* dynamic environment variables */
72 * No need to protect this with a mutex since SYSINITS are single threaded.
76 #define KENV_CHECK if (!dynamic_kenv) \
77 panic("%s: called before SI_SUB_KMEM", __func__)
89 char *name, *value, *buffer = NULL;
90 size_t len, done, needed, buflen;
93 KASSERT(dynamic_kenv, ("kenv: dynamic_kenv = 0"));
96 if (uap->what == KENV_DUMP) {
98 error = mac_kenv_check_dump(td->td_ucred);
104 if (buflen > KENV_SIZE * (KENV_MNAMELEN + KENV_MVALLEN + 2))
105 buflen = KENV_SIZE * (KENV_MNAMELEN +
107 if (uap->len > 0 && uap->value != NULL)
108 buffer = malloc(buflen, M_TEMP, M_WAITOK|M_ZERO);
109 mtx_lock(&kenv_lock);
110 for (i = 0; kenvp[i] != NULL; i++) {
111 len = strlen(kenvp[i]) + 1;
113 len = min(len, buflen - done);
115 * If called with a NULL or insufficiently large
116 * buffer, just keep computing the required size.
118 if (uap->value != NULL && buffer != NULL && len > 0) {
119 bcopy(kenvp[i], buffer + done, len);
123 mtx_unlock(&kenv_lock);
124 if (buffer != NULL) {
125 error = copyout(buffer, uap->value, done);
126 free(buffer, M_TEMP);
128 td->td_retval[0] = ((done == needed) ? 0 : needed);
134 error = priv_check(td, PRIV_KENV_SET);
140 error = priv_check(td, PRIV_KENV_UNSET);
146 name = malloc(KENV_MNAMELEN + 1, M_TEMP, M_WAITOK);
148 error = copyinstr(uap->name, name, KENV_MNAMELEN + 1, NULL);
155 error = mac_kenv_check_get(td->td_ucred, name);
159 value = getenv(name);
164 len = strlen(value) + 1;
167 error = copyout(value, uap->value, len);
171 td->td_retval[0] = len;
179 if (len > KENV_MVALLEN + 1)
180 len = KENV_MVALLEN + 1;
181 value = malloc(len, M_TEMP, M_WAITOK);
182 error = copyinstr(uap->value, value, len, NULL);
188 error = mac_kenv_check_set(td->td_ucred, name, value);
196 error = mac_kenv_check_unset(td->td_ucred, name);
200 error = unsetenv(name);
214 init_static_kenv(char *buf, size_t len)
222 * Setup the dynamic kernel environment.
225 init_dynamic_kenv(void *data __unused)
231 kenvp = malloc((KENV_SIZE + 1) * sizeof(char *), M_KENV,
234 for (cp = kern_envp; cp != NULL; cp = kernenv_next(cp)) {
235 len = strlen(cp) + 1;
236 if (len > KENV_MNAMELEN + 1 + KENV_MVALLEN + 1) {
237 printf("WARNING: too long kenv string, ignoring %s\n",
242 kenvp[i] = malloc(len, M_KENV, M_WAITOK);
243 strcpy(kenvp[i++], cp);
246 "WARNING: too many kenv strings, ignoring %s\n",
251 mtx_init(&kenv_lock, "kernel environment", NULL, MTX_DEF);
254 SYSINIT(kenv, SI_SUB_KMEM, SI_ORDER_ANY, init_dynamic_kenv, NULL);
265 * Internal functions for string lookup.
268 _getenv_dynamic(const char *name, int *idx)
273 mtx_assert(&kenv_lock, MA_OWNED);
275 for (cp = kenvp[0], i = 0; cp != NULL; cp = kenvp[++i]) {
276 if ((strncmp(cp, name, len) == 0) &&
280 return (cp + len + 1);
287 _getenv_static(const char *name)
292 for (cp = kern_envp; cp != NULL; cp = kernenv_next(cp)) {
293 for (ep = cp; (*ep != '=') && (*ep != 0); ep++)
299 if (!strncmp(name, cp, len) && name[len] == 0)
306 * Look up an environment variable by name.
307 * Return a pointer to the string if found.
308 * The pointer has to be freed with freeenv()
312 getenv(const char *name)
314 char buf[KENV_MNAMELEN + 1 + KENV_MVALLEN + 1];
319 mtx_lock(&kenv_lock);
320 cp = _getenv_dynamic(name, NULL);
323 mtx_unlock(&kenv_lock);
324 len = strlen(buf) + 1;
325 ret = malloc(len, M_KENV, M_WAITOK);
328 mtx_unlock(&kenv_lock);
330 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
334 ret = _getenv_static(name);
339 * Test if an environment variable is defined.
342 testenv(const char *name)
347 mtx_lock(&kenv_lock);
348 cp = _getenv_dynamic(name, NULL);
349 mtx_unlock(&kenv_lock);
351 cp = _getenv_static(name);
358 setenv_static(const char *name, const char *value)
362 if (env_pos >= env_len)
365 /* Check space for x=y and two nuls */
366 len = strlen(name) + strlen(value);
367 if (len + 3 < env_len - env_pos) {
368 len = sprintf(&kern_envp[env_pos], "%s=%s", name, value);
370 kern_envp[env_pos] = '\0';
378 * Set an environment variable by name.
381 setenv(const char *name, const char *value)
383 char *buf, *cp, *oldenv;
384 int namelen, vallen, i;
386 if (dynamic_kenv == 0 && env_len > 0)
387 return (setenv_static(name, value));
391 namelen = strlen(name) + 1;
392 if (namelen > KENV_MNAMELEN + 1)
394 vallen = strlen(value) + 1;
395 if (vallen > KENV_MVALLEN + 1)
397 buf = malloc(namelen + vallen, M_KENV, M_WAITOK);
398 sprintf(buf, "%s=%s", name, value);
400 mtx_lock(&kenv_lock);
401 cp = _getenv_dynamic(name, &i);
405 mtx_unlock(&kenv_lock);
406 free(oldenv, M_KENV);
408 /* We add the option if it wasn't found */
409 for (i = 0; (cp = kenvp[i]) != NULL; i++)
412 /* Bounds checking */
413 if (i < 0 || i >= KENV_SIZE) {
415 mtx_unlock(&kenv_lock);
421 mtx_unlock(&kenv_lock);
427 * Unset an environment variable string.
430 unsetenv(const char *name)
437 mtx_lock(&kenv_lock);
438 cp = _getenv_dynamic(name, &i);
441 for (j = i + 1; kenvp[j] != NULL; j++)
442 kenvp[i++] = kenvp[j];
444 mtx_unlock(&kenv_lock);
445 free(oldenv, M_KENV);
448 mtx_unlock(&kenv_lock);
453 * Return a string value from an environment variable.
456 getenv_string(const char *name, char *data, int size)
462 strlcpy(data, tmp, size);
470 * Return an integer value from an environment variable.
473 getenv_int(const char *name, int *data)
478 rval = getenv_quad(name, &tmp);
485 * Return an unsigned integer value from an environment variable.
488 getenv_uint(const char *name, unsigned int *data)
493 rval = getenv_quad(name, &tmp);
495 *data = (unsigned int) tmp;
500 * Return a long value from an environment variable.
503 getenv_long(const char *name, long *data)
508 rval = getenv_quad(name, &tmp);
515 * Return an unsigned long value from an environment variable.
518 getenv_ulong(const char *name, unsigned long *data)
523 rval = getenv_quad(name, &tmp);
525 *data = (unsigned long) tmp;
530 * Return a quad_t value from an environment variable.
533 getenv_quad(const char *name, quad_t *data)
539 value = getenv(name);
542 iv = strtoq(value, &vtp, 0);
543 if (vtp == value || (vtp[0] != '\0' && vtp[1] != '\0')) {
568 * Find the next entry after the one which (cp) falls within, return a
569 * pointer to its start or NULL if there are no more.
572 kernenv_next(char *cp)
586 tunable_int_init(void *data)
588 struct tunable_int *d = (struct tunable_int *)data;
590 TUNABLE_INT_FETCH(d->path, d->var);
594 tunable_long_init(void *data)
596 struct tunable_long *d = (struct tunable_long *)data;
598 TUNABLE_LONG_FETCH(d->path, d->var);
602 tunable_ulong_init(void *data)
604 struct tunable_ulong *d = (struct tunable_ulong *)data;
606 TUNABLE_ULONG_FETCH(d->path, d->var);
610 tunable_quad_init(void *data)
612 struct tunable_quad *d = (struct tunable_quad *)data;
614 TUNABLE_QUAD_FETCH(d->path, d->var);
618 tunable_str_init(void *data)
620 struct tunable_str *d = (struct tunable_str *)data;
622 TUNABLE_STR_FETCH(d->path, d->var, d->size);