freebsd-dev/sys/kern/subr_hints.c
Pedro F. Giffuni 8a36da99de sys/kern: adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 15:20:12 +00:00

494 lines
11 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2000,2001 Peter Wemm <peter@FreeBSD.org>
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/bus.h>
/*
* Access functions for device resources.
*/
static int checkmethod = 1;
static int use_kenv;
static char *hintp;
/*
* Define kern.hintmode sysctl, which only accept value 2, that cause to
* switch from Static KENV mode to Dynamic KENV. So systems that have hints
* compiled into kernel will be able to see/modify KENV (and hints too).
*/
static int
sysctl_hintmode(SYSCTL_HANDLER_ARGS)
{
const char *cp;
char *line, *eq;
int eqidx, error, from_kenv, i, value;
from_kenv = 0;
cp = kern_envp;
value = hintmode;
/* Fetch candidate for new hintmode value */
error = sysctl_handle_int(oidp, &value, 0, req);
if (error || req->newptr == NULL)
return (error);
if (value != 2)
/* Only accept swithing to hintmode 2 */
return (EINVAL);
/* Migrate from static to dynamic hints */
switch (hintmode) {
case 0:
if (dynamic_kenv) {
/*
* Already here. But assign hintmode to 2, to not
* check it in the future.
*/
hintmode = 2;
return (0);
}
from_kenv = 1;
cp = kern_envp;
break;
case 1:
cp = static_hints;
break;
case 2:
/* Nothing to do, hintmode already 2 */
return (0);
}
while (cp) {
i = strlen(cp);
if (i == 0)
break;
if (from_kenv) {
if (strncmp(cp, "hint.", 5) != 0)
/* kenv can have not only hints */
continue;
}
eq = strchr(cp, '=');
if (eq == NULL)
/* Bad hint value */
continue;
eqidx = eq - cp;
line = malloc(i+1, M_TEMP, M_WAITOK);
strcpy(line, cp);
line[eqidx] = '\0';
kern_setenv(line, line + eqidx + 1);
free(line, M_TEMP);
cp += i + 1;
}
hintmode = value;
use_kenv = 1;
return (0);
}
SYSCTL_PROC(_kern, OID_AUTO, hintmode, CTLTYPE_INT|CTLFLAG_RW,
&hintmode, 0, sysctl_hintmode, "I", "Get/set current hintmode");
/*
* Evil wildcarding resource string lookup.
* This walks the supplied env string table and returns a match.
* The start point can be remembered for incremental searches.
*/
static int
res_find(int *line, int *startln,
const char *name, int *unit, const char *resname, const char *value,
const char **ret_name, int *ret_namelen, int *ret_unit,
const char **ret_resname, int *ret_resnamelen, const char **ret_value)
{
int n = 0, hit, i = 0;
char r_name[32];
int r_unit;
char r_resname[32];
char r_value[128];
const char *s, *cp;
char *p;
if (checkmethod) {
hintp = NULL;
switch (hintmode) {
case 0: /* loader hints in environment only */
break;
case 1: /* static hints only */
hintp = static_hints;
checkmethod = 0;
break;
case 2: /* fallback mode */
if (dynamic_kenv) {
mtx_lock(&kenv_lock);
cp = kenvp[0];
for (i = 0; cp != NULL; cp = kenvp[++i]) {
if (!strncmp(cp, "hint.", 5)) {
use_kenv = 1;
checkmethod = 0;
break;
}
}
mtx_unlock(&kenv_lock);
} else {
cp = kern_envp;
while (cp) {
if (strncmp(cp, "hint.", 5) == 0) {
cp = NULL;
hintp = kern_envp;
break;
}
while (*cp != '\0')
cp++;
cp++;
if (*cp == '\0') {
cp = NULL;
hintp = static_hints;
break;
}
}
}
break;
default:
break;
}
if (hintp == NULL) {
if (dynamic_kenv) {
use_kenv = 1;
checkmethod = 0;
} else
hintp = kern_envp;
}
}
if (use_kenv) {
mtx_lock(&kenv_lock);
i = 0;
cp = kenvp[0];
if (cp == NULL) {
mtx_unlock(&kenv_lock);
return (ENOENT);
}
} else
cp = hintp;
while (cp) {
hit = 1;
(*line)++;
if (strncmp(cp, "hint.", 5) != 0)
hit = 0;
else
n = sscanf(cp, "hint.%32[^.].%d.%32[^=]=%127s",
r_name, &r_unit, r_resname, r_value);
if (hit && n != 4) {
printf("CONFIG: invalid hint '%s'\n", cp);
p = strchr(cp, 'h');
*p = 'H';
hit = 0;
}
if (hit && startln && *startln >= 0 && *line < *startln)
hit = 0;
if (hit && name && strcmp(name, r_name) != 0)
hit = 0;
if (hit && unit && *unit != r_unit)
hit = 0;
if (hit && resname && strcmp(resname, r_resname) != 0)
hit = 0;
if (hit && value && strcmp(value, r_value) != 0)
hit = 0;
if (hit)
break;
if (use_kenv) {
cp = kenvp[++i];
if (cp == NULL)
break;
} else {
while (*cp != '\0')
cp++;
cp++;
if (*cp == '\0') {
cp = NULL;
break;
}
}
}
if (use_kenv)
mtx_unlock(&kenv_lock);
if (cp == NULL)
return ENOENT;
s = cp;
/* This is a bit of a hack, but at least is reentrant */
/* Note that it returns some !unterminated! strings. */
s = strchr(s, '.') + 1; /* start of device */
if (ret_name)
*ret_name = s;
s = strchr(s, '.') + 1; /* start of unit */
if (ret_namelen && ret_name)
*ret_namelen = s - *ret_name - 1; /* device length */
if (ret_unit)
*ret_unit = r_unit;
s = strchr(s, '.') + 1; /* start of resname */
if (ret_resname)
*ret_resname = s;
s = strchr(s, '=') + 1; /* start of value */
if (ret_resnamelen && ret_resname)
*ret_resnamelen = s - *ret_resname - 1; /* value len */
if (ret_value)
*ret_value = s;
if (startln) /* line number for anchor */
*startln = *line + 1;
return 0;
}
/*
* Search all the data sources for matches to our query. We look for
* dynamic hints first as overrides for static or fallback hints.
*/
static int
resource_find(int *line, int *startln,
const char *name, int *unit, const char *resname, const char *value,
const char **ret_name, int *ret_namelen, int *ret_unit,
const char **ret_resname, int *ret_resnamelen, const char **ret_value)
{
int i;
int un;
*line = 0;
/* Search for exact unit matches first */
i = res_find(line, startln, name, unit, resname, value,
ret_name, ret_namelen, ret_unit, ret_resname, ret_resnamelen,
ret_value);
if (i == 0)
return 0;
if (unit == NULL)
return ENOENT;
/* If we are still here, search for wildcard matches */
un = -1;
i = res_find(line, startln, name, &un, resname, value,
ret_name, ret_namelen, ret_unit, ret_resname, ret_resnamelen,
ret_value);
if (i == 0)
return 0;
return ENOENT;
}
int
resource_int_value(const char *name, int unit, const char *resname, int *result)
{
int error;
const char *str;
char *op;
unsigned long val;
int line;
line = 0;
error = resource_find(&line, NULL, name, &unit, resname, NULL,
NULL, NULL, NULL, NULL, NULL, &str);
if (error)
return error;
if (*str == '\0')
return EFTYPE;
val = strtoul(str, &op, 0);
if (*op != '\0')
return EFTYPE;
*result = val;
return 0;
}
int
resource_long_value(const char *name, int unit, const char *resname,
long *result)
{
int error;
const char *str;
char *op;
unsigned long val;
int line;
line = 0;
error = resource_find(&line, NULL, name, &unit, resname, NULL,
NULL, NULL, NULL, NULL, NULL, &str);
if (error)
return error;
if (*str == '\0')
return EFTYPE;
val = strtoul(str, &op, 0);
if (*op != '\0')
return EFTYPE;
*result = val;
return 0;
}
int
resource_string_value(const char *name, int unit, const char *resname,
const char **result)
{
int error;
const char *str;
int line;
line = 0;
error = resource_find(&line, NULL, name, &unit, resname, NULL,
NULL, NULL, NULL, NULL, NULL, &str);
if (error)
return error;
*result = str;
return 0;
}
/*
* This is a bit nasty, but allows us to not modify the env strings.
*/
static const char *
resource_string_copy(const char *s, int len)
{
static char stringbuf[256];
static int offset = 0;
const char *ret;
if (len == 0)
len = strlen(s);
if (len > 255)
return NULL;
if ((offset + len + 1) > 255)
offset = 0;
bcopy(s, &stringbuf[offset], len);
stringbuf[offset + len] = '\0';
ret = &stringbuf[offset];
offset += len + 1;
return ret;
}
/*
* err = resource_find_match(&anchor, &name, &unit, resname, value)
* Iteratively fetch a list of devices wired "at" something
* res and value are restrictions. eg: "at", "scbus0".
* For practical purposes, res = required, value = optional.
* *name and *unit are set.
* set *anchor to zero before starting.
*/
int
resource_find_match(int *anchor, const char **name, int *unit,
const char *resname, const char *value)
{
const char *found_name;
int found_namelen;
int found_unit;
int ret;
int newln;
newln = *anchor;
ret = resource_find(anchor, &newln, NULL, NULL, resname, value,
&found_name, &found_namelen, &found_unit, NULL, NULL, NULL);
if (ret == 0) {
*name = resource_string_copy(found_name, found_namelen);
*unit = found_unit;
}
*anchor = newln;
return ret;
}
/*
* err = resource_find_dev(&anchor, name, &unit, res, value);
* Iterate through a list of devices, returning their unit numbers.
* res and value are optional restrictions. eg: "at", "scbus0".
* *unit is set to the value.
* set *anchor to zero before starting.
*/
int
resource_find_dev(int *anchor, const char *name, int *unit,
const char *resname, const char *value)
{
int found_unit;
int newln;
int ret;
newln = *anchor;
ret = resource_find(anchor, &newln, name, NULL, resname, value,
NULL, NULL, &found_unit, NULL, NULL, NULL);
if (ret == 0) {
*unit = found_unit;
}
*anchor = newln;
return ret;
}
/*
* Check to see if a device is disabled via a disabled hint.
*/
int
resource_disabled(const char *name, int unit)
{
int error, value;
error = resource_int_value(name, unit, "disabled", &value);
if (error)
return (0);
return (value);
}
/*
* Clear a value associated with a device by removing it from
* the kernel environment. This only removes a hint for an
* exact unit.
*/
int
resource_unset_value(const char *name, int unit, const char *resname)
{
char varname[128];
const char *retname, *retvalue;
int error, line;
size_t len;
line = 0;
error = resource_find(&line, NULL, name, &unit, resname, NULL,
&retname, NULL, NULL, NULL, NULL, &retvalue);
if (error)
return (error);
retname -= strlen("hint.");
len = retvalue - retname - 1;
if (len > sizeof(varname) - 1)
return (ENAMETOOLONG);
memcpy(varname, retname, len);
varname[len] = '\0';
return (kern_unsetenv(varname));
}