freebsd-dev/sys/kern/kern_environment.c
Kyle Evans db0f264393 kenv: allow listing of static kernel environments
The early environment is typically cleared, so these new options
need the PRESERVE_EARLY_KENV kernel config(8) option. These environments
are reported as missing by kenv(1) if the option is not present in the
running kernel.

Reviewed by:	imp
Differential Revision:	https://reviews.freebsd.org/D30835
2021-07-18 23:06:19 -05:00

1128 lines
24 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1998 Michael Smith
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* The unified bootloader passes us a pointer to a preserved copy of
* bootstrap/kernel environment variables. We convert them to a
* dynamic array of strings later when the VM subsystem is up.
*
* We make these available through the kenv(2) syscall for userland
* and through kern_getenv()/freeenv() kern_setenv() kern_unsetenv() testenv() for
* the kernel.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/priv.h>
#include <sys/kenv.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/sysent.h>
#include <sys/sysproto.h>
#include <sys/libkern.h>
#include <sys/kenv.h>
#include <sys/limits.h>
#include <security/mac/mac_framework.h>
static char *_getenv_dynamic_locked(const char *name, int *idx);
static char *_getenv_dynamic(const char *name, int *idx);
static char *kenv_acquire(const char *name);
static void kenv_release(const char *buf);
static MALLOC_DEFINE(M_KENV, "kenv", "kernel environment");
#define KENV_SIZE 512 /* Maximum number of environment strings */
static uma_zone_t kenv_zone;
static int kenv_mvallen = KENV_MVALLEN;
/* pointer to the config-generated static environment */
char *kern_envp;
/* pointer to the md-static environment */
char *md_envp;
static int md_env_len;
static int md_env_pos;
static char *kernenv_next(char *);
/* dynamic environment variables */
char **kenvp;
struct mtx kenv_lock;
/*
* No need to protect this with a mutex since SYSINITS are single threaded.
*/
bool dynamic_kenv;
#define KENV_CHECK if (!dynamic_kenv) \
panic("%s: called before SI_SUB_KMEM", __func__)
static int
kenv_dump(struct thread *td, char **envp, int what, char *value, int len)
{
char *buffer, *senv;
size_t done, needed, buflen;
int error;
error = 0;
buffer = NULL;
done = needed = 0;
MPASS(what == KENV_DUMP || what == KENV_DUMP_LOADER ||
what == KENV_DUMP_STATIC);
/*
* For non-dynamic kernel environment, we pass in either md_envp or
* kern_envp and we must traverse with kernenv_next(). This shuffling
* of pointers simplifies the below loop by only differing in how envp
* is modified.
*/
if (what != KENV_DUMP) {
senv = (char *)envp;
envp = &senv;
}
buflen = len;
if (buflen > KENV_SIZE * (KENV_MNAMELEN + kenv_mvallen + 2))
buflen = KENV_SIZE * (KENV_MNAMELEN +
kenv_mvallen + 2);
if (len > 0 && value != NULL)
buffer = malloc(buflen, M_TEMP, M_WAITOK|M_ZERO);
/* Only take the lock for the dynamic kenv. */
if (what == KENV_DUMP)
mtx_lock(&kenv_lock);
while (*envp != NULL) {
len = strlen(*envp) + 1;
needed += len;
len = min(len, buflen - done);
/*
* If called with a NULL or insufficiently large
* buffer, just keep computing the required size.
*/
if (value != NULL && buffer != NULL && len > 0) {
bcopy(*envp, buffer + done, len);
done += len;
}
/* Advance the pointer depending on the kenv format. */
if (what == KENV_DUMP)
envp++;
else
senv = kernenv_next(senv);
}
if (what == KENV_DUMP)
mtx_unlock(&kenv_lock);
if (buffer != NULL) {
error = copyout(buffer, value, done);
free(buffer, M_TEMP);
}
td->td_retval[0] = ((done == needed) ? 0 : needed);
return (error);
}
int
sys_kenv(struct thread *td, struct kenv_args *uap)
{
char *name, *value;
size_t len;
int error;
KASSERT(dynamic_kenv, ("kenv: dynamic_kenv = false"));
error = 0;
switch (uap->what) {
case KENV_DUMP:
#ifdef MAC
error = mac_kenv_check_dump(td->td_ucred);
if (error)
return (error);
#endif
return (kenv_dump(td, kenvp, uap->what, uap->value, uap->len));
case KENV_DUMP_LOADER:
case KENV_DUMP_STATIC:
#ifdef MAC
error = mac_kenv_check_dump(td->td_ucred);
if (error)
return (error);
#endif
#ifdef PRESERVE_EARLY_KENV
return (kenv_dump(td,
uap->what == KENV_DUMP_LOADER ? (char **)md_envp :
(char **)kern_envp, uap->what, uap->value, uap->len));
#else
return (ENOENT);
#endif
case KENV_SET:
error = priv_check(td, PRIV_KENV_SET);
if (error)
return (error);
break;
case KENV_UNSET:
error = priv_check(td, PRIV_KENV_UNSET);
if (error)
return (error);
break;
}
name = malloc(KENV_MNAMELEN + 1, M_TEMP, M_WAITOK);
error = copyinstr(uap->name, name, KENV_MNAMELEN + 1, NULL);
if (error)
goto done;
switch (uap->what) {
case KENV_GET:
#ifdef MAC
error = mac_kenv_check_get(td->td_ucred, name);
if (error)
goto done;
#endif
value = kern_getenv(name);
if (value == NULL) {
error = ENOENT;
goto done;
}
len = strlen(value) + 1;
if (len > uap->len)
len = uap->len;
error = copyout(value, uap->value, len);
freeenv(value);
if (error)
goto done;
td->td_retval[0] = len;
break;
case KENV_SET:
len = uap->len;
if (len < 1) {
error = EINVAL;
goto done;
}
if (len > kenv_mvallen + 1)
len = kenv_mvallen + 1;
value = malloc(len, M_TEMP, M_WAITOK);
error = copyinstr(uap->value, value, len, NULL);
if (error) {
free(value, M_TEMP);
goto done;
}
#ifdef MAC
error = mac_kenv_check_set(td->td_ucred, name, value);
if (error == 0)
#endif
kern_setenv(name, value);
free(value, M_TEMP);
break;
case KENV_UNSET:
#ifdef MAC
error = mac_kenv_check_unset(td->td_ucred, name);
if (error)
goto done;
#endif
error = kern_unsetenv(name);
if (error)
error = ENOENT;
break;
default:
error = EINVAL;
break;
}
done:
free(name, M_TEMP);
return (error);
}
/*
* Populate the initial kernel environment.
*
* This is called very early in MD startup, either to provide a copy of the
* environment obtained from a boot loader, or to provide an empty buffer into
* which MD code can store an initial environment using kern_setenv() calls.
*
* kern_envp is set to the static_env generated by config(8). This implements
* the env keyword described in config(5).
*
* If len is non-zero, the caller is providing an empty buffer. The caller will
* subsequently use kern_setenv() to add up to len bytes of initial environment
* before the dynamic environment is available.
*
* If len is zero, the caller is providing a pre-loaded buffer containing
* environment strings. Additional strings cannot be added until the dynamic
* environment is available. The memory pointed to must remain stable at least
* until sysinit runs init_dynamic_kenv() and preferably until after SI_SUB_KMEM
* is finished so that subr_hints routines may continue to use it until the
* environments have been fully merged at the end of the pass. If no initial
* environment is available from the boot loader, passing a NULL pointer allows
* the static_env to be installed if it is configured. In this case, any call
* to kern_setenv() prior to the setup of the dynamic environment will result in
* a panic.
*/
void
init_static_kenv(char *buf, size_t len)
{
KASSERT(!dynamic_kenv, ("kenv: dynamic_kenv already initialized"));
/*
* Suitably sized means it must be able to hold at least one empty
* variable, otherwise things go belly up if a kern_getenv call is
* made without a prior call to kern_setenv as we have a malformed
* environment.
*/
KASSERT(len == 0 || len >= 2,
("kenv: static env must be initialized or suitably sized"));
KASSERT(len == 0 || (*buf == '\0' && *(buf + 1) == '\0'),
("kenv: sized buffer must be initially empty"));
/*
* We may be called twice, with the second call needed to relocate
* md_envp after enabling paging. md_envp is then garbage if it is
* not null and the relocation will move it. Discard it so as to
* not crash using its old value in our first call to kern_getenv().
*
* The second call gives the same environment as the first except
* in silly configurations where the static env disables itself.
*
* Other env calls don't handle possibly-garbage pointers, so must
* not be made between enabling paging and calling here.
*/
md_envp = NULL;
md_env_len = 0;
md_env_pos = 0;
/*
* Give the static environment a chance to disable the loader(8)
* environment first. This is done with loader_env.disabled=1.
*
* static_env and static_hints may both be disabled, but in slightly
* different ways. For static_env, we just don't setup kern_envp and
* it's as if a static env wasn't even provided. For static_hints,
* we effectively zero out the buffer to stop the rest of the kernel
* from being able to use it.
*
* We're intentionally setting this up so that static_hints.disabled may
* be specified in either the MD env or the static env. This keeps us
* consistent in our new world view.
*
* As a warning, the static environment may not be disabled in any way
* if the static environment has disabled the loader environment.
*/
kern_envp = static_env;
if (!getenv_is_true("loader_env.disabled")) {
md_envp = buf;
md_env_len = len;
md_env_pos = 0;
if (getenv_is_true("static_env.disabled")) {
kern_envp[0] = '\0';
kern_envp[1] = '\0';
}
}
if (getenv_is_true("static_hints.disabled")) {
static_hints[0] = '\0';
static_hints[1] = '\0';
}
}
static void
init_dynamic_kenv_from(char *init_env, int *curpos)
{
char *cp, *cpnext, *eqpos, *found;
size_t len;
int i;
if (init_env && *init_env != '\0') {
found = NULL;
i = *curpos;
for (cp = init_env; cp != NULL; cp = cpnext) {
cpnext = kernenv_next(cp);
len = strlen(cp) + 1;
if (len > KENV_MNAMELEN + 1 + kenv_mvallen + 1) {
printf(
"WARNING: too long kenv string, ignoring %s\n",
cp);
goto sanitize;
}
eqpos = strchr(cp, '=');
if (eqpos == NULL) {
printf(
"WARNING: malformed static env value, ignoring %s\n",
cp);
goto sanitize;
}
*eqpos = 0;
/*
* De-dupe the environment as we go. We don't add the
* duplicated assignments because config(8) will flip
* the order of the static environment around to make
* kernel processing match the order of specification
* in the kernel config.
*/
found = _getenv_dynamic_locked(cp, NULL);
*eqpos = '=';
if (found != NULL)
goto sanitize;
if (i > KENV_SIZE) {
printf(
"WARNING: too many kenv strings, ignoring %s\n",
cp);
goto sanitize;
}
kenvp[i] = malloc(len, M_KENV, M_WAITOK);
strcpy(kenvp[i++], cp);
sanitize:
#ifdef PRESERVE_EARLY_KENV
continue;
#else
explicit_bzero(cp, len - 1);
#endif
}
*curpos = i;
}
}
/*
* Setup the dynamic kernel environment.
*/
static void
init_dynamic_kenv(void *data __unused)
{
int dynamic_envpos;
int size;
TUNABLE_INT_FETCH("kenv_mvallen", &kenv_mvallen);
size = KENV_MNAMELEN + 1 + kenv_mvallen + 1;
kenv_zone = uma_zcreate("kenv", size, NULL, NULL, NULL, NULL,
UMA_ALIGN_PTR, 0);
kenvp = malloc((KENV_SIZE + 1) * sizeof(char *), M_KENV,
M_WAITOK | M_ZERO);
dynamic_envpos = 0;
init_dynamic_kenv_from(md_envp, &dynamic_envpos);
init_dynamic_kenv_from(kern_envp, &dynamic_envpos);
kenvp[dynamic_envpos] = NULL;
mtx_init(&kenv_lock, "kernel environment", NULL, MTX_DEF);
dynamic_kenv = true;
}
SYSINIT(kenv, SI_SUB_KMEM + 1, SI_ORDER_FIRST, init_dynamic_kenv, NULL);
void
freeenv(char *env)
{
if (dynamic_kenv && env != NULL) {
explicit_bzero(env, strlen(env));
uma_zfree(kenv_zone, env);
}
}
/*
* Internal functions for string lookup.
*/
static char *
_getenv_dynamic_locked(const char *name, int *idx)
{
char *cp;
int len, i;
len = strlen(name);
for (cp = kenvp[0], i = 0; cp != NULL; cp = kenvp[++i]) {
if ((strncmp(cp, name, len) == 0) &&
(cp[len] == '=')) {
if (idx != NULL)
*idx = i;
return (cp + len + 1);
}
}
return (NULL);
}
static char *
_getenv_dynamic(const char *name, int *idx)
{
mtx_assert(&kenv_lock, MA_OWNED);
return (_getenv_dynamic_locked(name, idx));
}
static char *
_getenv_static_from(char *chkenv, const char *name)
{
char *cp, *ep;
int len;
for (cp = chkenv; cp != NULL; cp = kernenv_next(cp)) {
for (ep = cp; (*ep != '=') && (*ep != 0); ep++)
;
if (*ep != '=')
continue;
len = ep - cp;
ep++;
if (!strncmp(name, cp, len) && name[len] == 0)
return (ep);
}
return (NULL);
}
static char *
_getenv_static(const char *name)
{
char *val;
val = _getenv_static_from(md_envp, name);
if (val != NULL)
return (val);
val = _getenv_static_from(kern_envp, name);
if (val != NULL)
return (val);
return (NULL);
}
/*
* Look up an environment variable by name.
* Return a pointer to the string if found.
* The pointer has to be freed with freeenv()
* after use.
*/
char *
kern_getenv(const char *name)
{
char *cp, *ret;
int len;
if (dynamic_kenv) {
len = KENV_MNAMELEN + 1 + kenv_mvallen + 1;
ret = uma_zalloc(kenv_zone, M_WAITOK | M_ZERO);
mtx_lock(&kenv_lock);
cp = _getenv_dynamic(name, NULL);
if (cp != NULL)
strlcpy(ret, cp, len);
mtx_unlock(&kenv_lock);
if (cp == NULL) {
uma_zfree(kenv_zone, ret);
ret = NULL;
}
} else
ret = _getenv_static(name);
return (ret);
}
/*
* Test if an environment variable is defined.
*/
int
testenv(const char *name)
{
char *cp;
cp = kenv_acquire(name);
kenv_release(cp);
if (cp != NULL)
return (1);
return (0);
}
/*
* Set an environment variable in the MD-static environment. This cannot
* feasibly be done on config(8)-generated static environments as they don't
* generally include space for extra variables.
*/
static int
setenv_static(const char *name, const char *value)
{
int len;
if (md_env_pos >= md_env_len)
return (-1);
/* Check space for x=y and two nuls */
len = strlen(name) + strlen(value);
if (len + 3 < md_env_len - md_env_pos) {
len = sprintf(&md_envp[md_env_pos], "%s=%s", name, value);
md_env_pos += len+1;
md_envp[md_env_pos] = '\0';
return (0);
} else
return (-1);
}
/*
* Set an environment variable by name.
*/
int
kern_setenv(const char *name, const char *value)
{
char *buf, *cp, *oldenv;
int namelen, vallen, i;
if (!dynamic_kenv && md_env_len > 0)
return (setenv_static(name, value));
KENV_CHECK;
namelen = strlen(name) + 1;
if (namelen > KENV_MNAMELEN + 1)
return (-1);
vallen = strlen(value) + 1;
if (vallen > kenv_mvallen + 1)
return (-1);
buf = malloc(namelen + vallen, M_KENV, M_WAITOK);
sprintf(buf, "%s=%s", name, value);
mtx_lock(&kenv_lock);
cp = _getenv_dynamic(name, &i);
if (cp != NULL) {
oldenv = kenvp[i];
kenvp[i] = buf;
mtx_unlock(&kenv_lock);
free(oldenv, M_KENV);
} else {
/* We add the option if it wasn't found */
for (i = 0; (cp = kenvp[i]) != NULL; i++)
;
/* Bounds checking */
if (i < 0 || i >= KENV_SIZE) {
free(buf, M_KENV);
mtx_unlock(&kenv_lock);
return (-1);
}
kenvp[i] = buf;
kenvp[i + 1] = NULL;
mtx_unlock(&kenv_lock);
}
return (0);
}
/*
* Unset an environment variable string.
*/
int
kern_unsetenv(const char *name)
{
char *cp, *oldenv;
int i, j;
KENV_CHECK;
mtx_lock(&kenv_lock);
cp = _getenv_dynamic(name, &i);
if (cp != NULL) {
oldenv = kenvp[i];
for (j = i + 1; kenvp[j] != NULL; j++)
kenvp[i++] = kenvp[j];
kenvp[i] = NULL;
mtx_unlock(&kenv_lock);
zfree(oldenv, M_KENV);
return (0);
}
mtx_unlock(&kenv_lock);
return (-1);
}
/*
* Return the internal kenv buffer for the variable name, if it exists.
* If the dynamic kenv is initialized and the name is present, return
* with kenv_lock held.
*/
static char *
kenv_acquire(const char *name)
{
char *value;
if (dynamic_kenv) {
mtx_lock(&kenv_lock);
value = _getenv_dynamic(name, NULL);
if (value == NULL)
mtx_unlock(&kenv_lock);
return (value);
} else
return (_getenv_static(name));
}
/*
* Undo a previous kenv_acquire() operation
*/
static void
kenv_release(const char *buf)
{
if ((buf != NULL) && dynamic_kenv)
mtx_unlock(&kenv_lock);
}
/*
* Return a string value from an environment variable.
*/
int
getenv_string(const char *name, char *data, int size)
{
char *cp;
cp = kenv_acquire(name);
if (cp != NULL)
strlcpy(data, cp, size);
kenv_release(cp);
return (cp != NULL);
}
/*
* Return an array of integers at the given type size and signedness.
*/
int
getenv_array(const char *name, void *pdata, int size, int *psize,
int type_size, bool allow_signed)
{
uint8_t shift;
int64_t value;
int64_t old;
const char *buf;
char *end;
const char *ptr;
int n;
int rc;
rc = 0; /* assume failure */
buf = kenv_acquire(name);
if (buf == NULL)
goto error;
/* get maximum number of elements */
size /= type_size;
n = 0;
for (ptr = buf; *ptr != 0; ) {
value = strtoq(ptr, &end, 0);
/* check if signed numbers are allowed */
if (value < 0 && !allow_signed)
goto error;
/* check for invalid value */
if (ptr == end)
goto error;
/* check for valid suffix */
switch (*end) {
case 't':
case 'T':
shift = 40;
end++;
break;
case 'g':
case 'G':
shift = 30;
end++;
break;
case 'm':
case 'M':
shift = 20;
end++;
break;
case 'k':
case 'K':
shift = 10;
end++;
break;
case ' ':
case '\t':
case ',':
case 0:
shift = 0;
break;
default:
/* garbage after numeric value */
goto error;
}
/* skip till next value, if any */
while (*end == '\t' || *end == ',' || *end == ' ')
end++;
/* update pointer */
ptr = end;
/* apply shift */
old = value;
value <<= shift;
/* overflow check */
if ((value >> shift) != old)
goto error;
/* check for buffer overflow */
if (n >= size)
goto error;
/* store value according to type size */
switch (type_size) {
case 1:
if (allow_signed) {
if (value < SCHAR_MIN || value > SCHAR_MAX)
goto error;
} else {
if (value < 0 || value > UCHAR_MAX)
goto error;
}
((uint8_t *)pdata)[n] = (uint8_t)value;
break;
case 2:
if (allow_signed) {
if (value < SHRT_MIN || value > SHRT_MAX)
goto error;
} else {
if (value < 0 || value > USHRT_MAX)
goto error;
}
((uint16_t *)pdata)[n] = (uint16_t)value;
break;
case 4:
if (allow_signed) {
if (value < INT_MIN || value > INT_MAX)
goto error;
} else {
if (value > UINT_MAX)
goto error;
}
((uint32_t *)pdata)[n] = (uint32_t)value;
break;
case 8:
((uint64_t *)pdata)[n] = (uint64_t)value;
break;
default:
goto error;
}
n++;
}
*psize = n * type_size;
if (n != 0)
rc = 1; /* success */
error:
kenv_release(buf);
return (rc);
}
/*
* Return an integer value from an environment variable.
*/
int
getenv_int(const char *name, int *data)
{
quad_t tmp;
int rval;
rval = getenv_quad(name, &tmp);
if (rval)
*data = (int) tmp;
return (rval);
}
/*
* Return an unsigned integer value from an environment variable.
*/
int
getenv_uint(const char *name, unsigned int *data)
{
quad_t tmp;
int rval;
rval = getenv_quad(name, &tmp);
if (rval)
*data = (unsigned int) tmp;
return (rval);
}
/*
* Return an int64_t value from an environment variable.
*/
int
getenv_int64(const char *name, int64_t *data)
{
quad_t tmp;
int64_t rval;
rval = getenv_quad(name, &tmp);
if (rval)
*data = (int64_t) tmp;
return (rval);
}
/*
* Return an uint64_t value from an environment variable.
*/
int
getenv_uint64(const char *name, uint64_t *data)
{
quad_t tmp;
uint64_t rval;
rval = getenv_quad(name, &tmp);
if (rval)
*data = (uint64_t) tmp;
return (rval);
}
/*
* Return a long value from an environment variable.
*/
int
getenv_long(const char *name, long *data)
{
quad_t tmp;
int rval;
rval = getenv_quad(name, &tmp);
if (rval)
*data = (long) tmp;
return (rval);
}
/*
* Return an unsigned long value from an environment variable.
*/
int
getenv_ulong(const char *name, unsigned long *data)
{
quad_t tmp;
int rval;
rval = getenv_quad(name, &tmp);
if (rval)
*data = (unsigned long) tmp;
return (rval);
}
/*
* Return a quad_t value from an environment variable.
*/
int
getenv_quad(const char *name, quad_t *data)
{
const char *value;
char suffix, *vtp;
quad_t iv;
value = kenv_acquire(name);
if (value == NULL) {
goto error;
}
iv = strtoq(value, &vtp, 0);
if (vtp == value || (vtp[0] != '\0' && vtp[1] != '\0')) {
goto error;
}
suffix = vtp[0];
kenv_release(value);
switch (suffix) {
case 't': case 'T':
iv *= 1024;
/* FALLTHROUGH */
case 'g': case 'G':
iv *= 1024;
/* FALLTHROUGH */
case 'm': case 'M':
iv *= 1024;
/* FALLTHROUGH */
case 'k': case 'K':
iv *= 1024;
case '\0':
break;
default:
return (0);
}
*data = iv;
return (1);
error:
kenv_release(value);
return (0);
}
/*
* Return a boolean value from an environment variable. This can be in
* numerical or string form, i.e. "1" or "true".
*/
int
getenv_bool(const char *name, bool *data)
{
char *val;
int ret = 0;
if (name == NULL)
return (0);
val = kern_getenv(name);
if (val == NULL)
return (0);
if ((strcmp(val, "1") == 0) || (strcasecmp(val, "true") == 0)) {
*data = true;
ret = 1;
} else if ((strcmp(val, "0") == 0) || (strcasecmp(val, "false") == 0)) {
*data = false;
ret = 1;
} else {
/* Spit out a warning for malformed boolean variables. */
printf("Environment variable %s has non-boolean value \"%s\"\n",
name, val);
}
freeenv(val);
return (ret);
}
/*
* Wrapper around getenv_bool to easily check for true.
*/
bool
getenv_is_true(const char *name)
{
bool val;
if (getenv_bool(name, &val) != 0)
return (val);
return (false);
}
/*
* Wrapper around getenv_bool to easily check for false.
*/
bool
getenv_is_false(const char *name)
{
bool val;
if (getenv_bool(name, &val) != 0)
return (!val);
return (false);
}
/*
* Find the next entry after the one which (cp) falls within, return a
* pointer to its start or NULL if there are no more.
*/
static char *
kernenv_next(char *cp)
{
if (cp != NULL) {
while (*cp != 0)
cp++;
cp++;
if (*cp == 0)
cp = NULL;
}
return (cp);
}
void
tunable_int_init(void *data)
{
struct tunable_int *d = (struct tunable_int *)data;
TUNABLE_INT_FETCH(d->path, d->var);
}
void
tunable_long_init(void *data)
{
struct tunable_long *d = (struct tunable_long *)data;
TUNABLE_LONG_FETCH(d->path, d->var);
}
void
tunable_ulong_init(void *data)
{
struct tunable_ulong *d = (struct tunable_ulong *)data;
TUNABLE_ULONG_FETCH(d->path, d->var);
}
void
tunable_int64_init(void *data)
{
struct tunable_int64 *d = (struct tunable_int64 *)data;
TUNABLE_INT64_FETCH(d->path, d->var);
}
void
tunable_uint64_init(void *data)
{
struct tunable_uint64 *d = (struct tunable_uint64 *)data;
TUNABLE_UINT64_FETCH(d->path, d->var);
}
void
tunable_quad_init(void *data)
{
struct tunable_quad *d = (struct tunable_quad *)data;
TUNABLE_QUAD_FETCH(d->path, d->var);
}
void
tunable_bool_init(void *data)
{
struct tunable_bool *d = (struct tunable_bool *)data;
TUNABLE_BOOL_FETCH(d->path, d->var);
}
void
tunable_str_init(void *data)
{
struct tunable_str *d = (struct tunable_str *)data;
TUNABLE_STR_FETCH(d->path, d->var, d->size);
}