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("$FreeBSD$");
42 #include <sys/types.h>
43 #include <sys/param.h>
45 #include <sys/queue.h>
48 #include <sys/malloc.h>
49 #include <sys/mutex.h>
50 #include <sys/kernel.h>
52 #include <sys/systm.h>
53 #include <sys/sysent.h>
54 #include <sys/sysproto.h>
55 #include <sys/libkern.h>
58 static MALLOC_DEFINE(M_KENV, "kenv", "kernel environment");
60 #define KENV_SIZE 512 /* Maximum number of environment strings */
62 /* pointer to the static environment */
64 static char *kernenv_next(char *);
66 /* dynamic environment variables */
71 * No need to protect this with a mutex
72 * since SYSINITS are single threaded.
76 #define KENV_CHECK if (!dynamic_kenv) \
77 panic("%s: called before SI_SUB_KMEM", __func__)
90 size_t len, done, needed;
93 KASSERT(dynamic_kenv, ("kenv: dynamic_kenv = 0"));
96 if (uap->what == KENV_DUMP) {
98 error = mac_check_kenv_dump(td->td_ucred);
103 sx_slock(&kenv_lock);
104 for (i = 0; kenvp[i] != NULL; i++) {
105 len = strlen(kenvp[i]) + 1;
107 len = min(len, uap->len - done);
109 * If called with a NULL or insufficiently large
110 * buffer, just keep computing the required size.
112 if (uap->value != NULL && len > 0) {
113 error = copyout(kenvp[i], uap->value + done,
120 sx_sunlock(&kenv_lock);
121 td->td_retval[0] = ((done == needed) ? 0 : needed);
125 if ((uap->what == KENV_SET) ||
126 (uap->what == KENV_UNSET)) {
132 name = malloc(KENV_MNAMELEN, M_TEMP, M_WAITOK);
134 error = copyinstr(uap->name, name, KENV_MNAMELEN, NULL);
141 error = mac_check_kenv_get(td->td_ucred, name);
145 value = getenv(name);
150 len = strlen(value) + 1;
153 error = copyout(value, uap->value, len);
157 td->td_retval[0] = len;
165 if (len > KENV_MVALLEN)
167 value = malloc(len, M_TEMP, M_WAITOK);
168 error = copyinstr(uap->value, value, len, NULL);
174 error = mac_check_kenv_set(td->td_ucred, name, value);
182 error = mac_check_kenv_unset(td->td_ucred, name);
186 error = unsetenv(name);
200 * Setup the dynamic kernel environment.
203 init_dynamic_kenv(void *data __unused)
208 kenvp = malloc((KENV_SIZE + 1) * sizeof(char *), M_KENV,
211 for (cp = kern_envp; cp != NULL; cp = kernenv_next(cp)) {
212 len = strlen(cp) + 1;
213 kenvp[i] = malloc(len, M_KENV, M_WAITOK);
214 strcpy(kenvp[i++], cp);
218 sx_init(&kenv_lock, "kernel environment");
221 SYSINIT(kenv, SI_SUB_KMEM, SI_ORDER_ANY, init_dynamic_kenv, NULL);
232 * Internal functions for string lookup.
235 _getenv_dynamic(const char *name, int *idx)
240 sx_assert(&kenv_lock, SX_LOCKED);
242 for (cp = kenvp[0], i = 0; cp != NULL; cp = kenvp[++i]) {
243 if ((strncmp(cp, name, len) == 0) &&
247 return (cp + len + 1);
254 _getenv_static(const char *name)
259 for (cp = kern_envp; cp != NULL; cp = kernenv_next(cp)) {
260 for (ep = cp; (*ep != '=') && (*ep != 0); ep++)
266 if (!strncmp(name, cp, len) && name[len] == 0)
273 * Look up an environment variable by name.
274 * Return a pointer to the string if found.
275 * The pointer has to be freed with freeenv()
279 getenv(const char *name)
281 char buf[KENV_MNAMELEN + 1 + KENV_MVALLEN + 1];
286 sx_slock(&kenv_lock);
287 cp = _getenv_dynamic(name, NULL);
290 sx_sunlock(&kenv_lock);
291 len = strlen(buf) + 1;
292 ret = malloc(len, M_KENV, M_WAITOK);
295 sx_sunlock(&kenv_lock);
299 ret = _getenv_static(name);
304 * Test if an environment variable is defined.
307 testenv(const char *name)
312 sx_slock(&kenv_lock);
313 cp = _getenv_dynamic(name, NULL);
314 sx_sunlock(&kenv_lock);
316 cp = _getenv_static(name);
323 * Set an environment variable by name.
326 setenv(const char *name, const char *value)
328 char *buf, *cp, *oldenv;
329 int namelen, vallen, i;
333 namelen = strlen(name) + 1;
334 if (namelen > KENV_MNAMELEN)
336 vallen = strlen(value) + 1;
337 if (vallen > KENV_MVALLEN)
339 buf = malloc(namelen + vallen, M_KENV, M_WAITOK);
340 sprintf(buf, "%s=%s", name, value);
342 sx_xlock(&kenv_lock);
343 cp = _getenv_dynamic(name, &i);
347 sx_xunlock(&kenv_lock);
348 free(oldenv, M_KENV);
350 /* We add the option if it wasn't found */
351 for (i = 0; (cp = kenvp[i]) != NULL; i++)
354 /* Bounds checking */
355 if (i < 0 || i >= KENV_SIZE) {
357 sx_xunlock(&kenv_lock);
363 sx_xunlock(&kenv_lock);
369 * Unset an environment variable string.
372 unsetenv(const char *name)
379 sx_xlock(&kenv_lock);
380 cp = _getenv_dynamic(name, &i);
383 for (j = i + 1; kenvp[j] != NULL; j++)
384 kenvp[i++] = kenvp[j];
386 sx_xunlock(&kenv_lock);
387 free(oldenv, M_KENV);
390 sx_xunlock(&kenv_lock);
395 * Return a string value from an environment variable.
398 getenv_string(const char *name, char *data, int size)
404 strlcpy(data, tmp, size);
412 * Return an integer value from an environment variable.
415 getenv_int(const char *name, int *data)
420 rval = getenv_quad(name, &tmp);
427 * Return a long value from an environment variable.
430 getenv_long(const char *name, long *data)
435 rval = getenv_quad(name, &tmp);
442 * Return an unsigned long value from an environment variable.
445 getenv_ulong(const char *name, unsigned long *data)
450 rval = getenv_quad(name, &tmp);
452 *data = (unsigned long) tmp;
457 * Return a quad_t value from an environment variable.
460 getenv_quad(const char *name, quad_t *data)
466 value = getenv(name);
469 iv = strtoq(value, &vtp, 0);
470 if (vtp == value || (vtp[0] != '\0' && vtp[1] != '\0')) {
495 * Find the next entry after the one which (cp) falls within, return a
496 * pointer to its start or NULL if there are no more.
499 kernenv_next(char *cp)
513 tunable_int_init(void *data)
515 struct tunable_int *d = (struct tunable_int *)data;
517 TUNABLE_INT_FETCH(d->path, d->var);
521 tunable_long_init(void *data)
523 struct tunable_long *d = (struct tunable_long *)data;
525 TUNABLE_LONG_FETCH(d->path, d->var);
529 tunable_ulong_init(void *data)
531 struct tunable_ulong *d = (struct tunable_ulong *)data;
533 TUNABLE_ULONG_FETCH(d->path, d->var);
537 tunable_str_init(void *data)
539 struct tunable_str *d = (struct tunable_str *)data;
541 TUNABLE_STR_FETCH(d->path, d->var, d->size);