Page MenuHomeFreeBSD
Differential D20219 Diff 60562 head/sys/kern/kern_sysctl.c

Changeset View

Standalone View

View Options

head/sys/kern/kern_sysctl.c

Show All 35 Lines
* *
* @(#)kern_sysctl.c 8.4 (Berkeley) 4/14/94 * @(#)kern_sysctl.c 8.4 (Berkeley) 4/14/94
*/ */
#include <sys/cdefs.h> #include <sys/cdefs.h>
__FBSDID("$FreeBSD$"); __FBSDID("$FreeBSD$");
#include "opt_capsicum.h" #include "opt_capsicum.h"
#include "opt_ddb.h"
#include "opt_ktrace.h" #include "opt_ktrace.h"
#include <sys/param.h> #include <sys/param.h>
#include <sys/fail.h> #include <sys/fail.h>
#include <sys/systm.h> #include <sys/systm.h>
#include <sys/capsicum.h> #include <sys/capsicum.h>
#include <sys/kernel.h> #include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/sysctl.h> #include <sys/sysctl.h>
#include <sys/malloc.h> #include <sys/malloc.h>
#include <sys/priv.h> #include <sys/priv.h>
#include <sys/proc.h> #include <sys/proc.h>
#include <sys/jail.h> #include <sys/jail.h>
#include <sys/lock.h> #include <sys/lock.h>
#include <sys/mutex.h> #include <sys/mutex.h>
#include <sys/rmlock.h> #include <sys/rmlock.h>
#include <sys/sbuf.h> #include <sys/sbuf.h>
#include <sys/sx.h> #include <sys/sx.h>
#include <sys/sysproto.h> #include <sys/sysproto.h>
#include <sys/uio.h> #include <sys/uio.h>
#ifdef KTRACE #ifdef KTRACE
#include <sys/ktrace.h> #include <sys/ktrace.h>
#endif #endif
#ifdef DDB
#include <sys/kdb.h>
#include <ddb/ddb.h>
#include <ddb/db_lex.h>
#endif
#include <net/vnet.h> #include <net/vnet.h>
#include <security/mac/mac_framework.h> #include <security/mac/mac_framework.h>
#include <vm/vm.h> #include <vm/vm.h>
#include <vm/vm_extern.h> #include <vm/vm_extern.h>
static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic"); static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic");
▲ Show 20 Lines • Show All 1,529 Lines • ▼ Show 20 Lines
int int
sysctl_handle_string(SYSCTL_HANDLER_ARGS) sysctl_handle_string(SYSCTL_HANDLER_ARGS)
{ {
size_t outlen; size_t outlen;
int error = 0, ro_string = 0; int error = 0, ro_string = 0;
/* /*
* A zero-length buffer indicates a fixed size read-only * A zero-length buffer indicates a fixed size read-only
* string: * string. In ddb, don't worry about trying to make a malloced
* snapshot.
*/ */
if (arg2 == 0) { if (arg2 == 0 || kdb_active) {
arg2 = strlen((char *)arg1) + 1; arg2 = strlen((char *)arg1) + 1;
ro_string = 1; ro_string = 1;
} }
if (req->oldptr != NULL) { if (req->oldptr != NULL) {
char *tmparg; char *tmparg;
if (ro_string) { if (ro_string) {
▲ Show 20 Lines • Show All 612 Lines • ▼ Show 20 Linessbuf_new_for_sysctl(struct sbuf *s, char *buf, int length,
/* Supply a default buffer size if none given. */ /* Supply a default buffer size if none given. */
if (buf == NULL && length == 0) if (buf == NULL && length == 0)
length = 64; length = 64;
s = sbuf_new(s, buf, length, SBUF_FIXEDLEN | SBUF_INCLUDENUL); s = sbuf_new(s, buf, length, SBUF_FIXEDLEN | SBUF_INCLUDENUL);
sbuf_set_drain(s, sbuf_sysctl_drain, req); sbuf_set_drain(s, sbuf_sysctl_drain, req);
return (s); return (s);
} }
#ifdef DDB
/* The current OID the debugger is working with */
static struct sysctl_oid *g_ddb_oid;
/* The current flags specified by the user */
static int g_ddb_sysctl_flags;
/* Check to see if the last sysctl printed */
static int g_ddb_sysctl_printed;
static const int ctl_sign[CTLTYPE+1] = {
[CTLTYPE_INT] = 1,
[CTLTYPE_LONG] = 1,
[CTLTYPE_S8] = 1,
[CTLTYPE_S16] = 1,
[CTLTYPE_S32] = 1,
[CTLTYPE_S64] = 1,
};
static const int ctl_size[CTLTYPE+1] = {
[CTLTYPE_INT] = sizeof(int),
[CTLTYPE_UINT] = sizeof(u_int),
[CTLTYPE_LONG] = sizeof(long),
[CTLTYPE_ULONG] = sizeof(u_long),
[CTLTYPE_S8] = sizeof(int8_t),
[CTLTYPE_S16] = sizeof(int16_t),
[CTLTYPE_S32] = sizeof(int32_t),
[CTLTYPE_S64] = sizeof(int64_t),
[CTLTYPE_U8] = sizeof(uint8_t),
[CTLTYPE_U16] = sizeof(uint16_t),
[CTLTYPE_U32] = sizeof(uint32_t),
[CTLTYPE_U64] = sizeof(uint64_t),
};
#define DB_SYSCTL_NAME_ONLY 0x001 /* Compare with -N */
#define DB_SYSCTL_VALUE_ONLY 0x002 /* Compare with -n */
#define DB_SYSCTL_OPAQUE 0x004 /* Compare with -o */
#define DB_SYSCTL_HEX 0x008 /* Compare with -x */
#define DB_SYSCTL_SAFE_ONLY 0x100 /* Only simple types */
static const char db_sysctl_modifs[] = {
'N', 'n', 'o', 'x',
};
static const int db_sysctl_modif_values[] = {
DB_SYSCTL_NAME_ONLY, DB_SYSCTL_VALUE_ONLY,
DB_SYSCTL_OPAQUE, DB_SYSCTL_HEX,
};
/* Handlers considered safe to print while recursing */
static int (* const db_safe_handlers[])(SYSCTL_HANDLER_ARGS) = {
sysctl_handle_bool,
sysctl_handle_8,
sysctl_handle_16,
sysctl_handle_32,
sysctl_handle_64,
sysctl_handle_int,
sysctl_handle_long,
sysctl_handle_string,
sysctl_handle_opaque,
};
/*
* Use in place of sysctl_old_kernel to print sysctl values.
*
* Compare to the output handling in show_var from sbin/sysctl/sysctl.c
*/
static int
sysctl_old_ddb(struct sysctl_req *req, const void *ptr, size_t len)
{
const u_char *val, *p;
const char *sep1;
size_t intlen, slen;
uintmax_t umv;
intmax_t mv;
int sign, ctltype, hexlen, xflag, error;
/* Suppress false-positive GCC uninitialized variable warnings */
mv = 0;
umv = 0;
slen = len;
val = p = ptr;
if (ptr == NULL) {
error = 0;
goto out;
}
/* We are going to print */
g_ddb_sysctl_printed = 1;
xflag = g_ddb_sysctl_flags & DB_SYSCTL_HEX;
ctltype = (g_ddb_oid->oid_kind & CTLTYPE);
sign = ctl_sign[ctltype];
intlen = ctl_size[ctltype];
switch (ctltype) {
case CTLTYPE_NODE:
case CTLTYPE_STRING:
db_printf("%.*s", (int) len, (const char *) p);
error = 0;
goto out;
case CTLTYPE_INT:
case CTLTYPE_UINT:
case CTLTYPE_LONG:
case CTLTYPE_ULONG:
case CTLTYPE_S8:
case CTLTYPE_S16:
case CTLTYPE_S32:
case CTLTYPE_S64:
case CTLTYPE_U8:
case CTLTYPE_U16:
case CTLTYPE_U32:
case CTLTYPE_U64:
hexlen = 2 + (intlen * CHAR_BIT + 3) / 4;
sep1 = "";
while (len >= intlen) {
switch (ctltype) {
case CTLTYPE_INT:
case CTLTYPE_UINT:
umv = *(const u_int *)p;
mv = *(const int *)p;
break;
case CTLTYPE_LONG:
case CTLTYPE_ULONG:
umv = *(const u_long *)p;
mv = *(const long *)p;
break;
case CTLTYPE_S8:
case CTLTYPE_U8:
umv = *(const uint8_t *)p;
mv = *(const int8_t *)p;
break;
case CTLTYPE_S16:
case CTLTYPE_U16:
umv = *(const uint16_t *)p;
mv = *(const int16_t *)p;
break;
case CTLTYPE_S32:
case CTLTYPE_U32:
umv = *(const uint32_t *)p;
mv = *(const int32_t *)p;
break;
case CTLTYPE_S64:
case CTLTYPE_U64:
umv = *(const uint64_t *)p;
mv = *(const int64_t *)p;
break;
}
db_printf("%s", sep1);
if (xflag)
db_printf("%#0*jx", hexlen, umv);
else if (!sign)
db_printf("%ju", umv);
else if (g_ddb_oid->oid_fmt[1] == 'K') {
/* Kelvins are currently unsupported. */
error = EOPNOTSUPP;
goto out;
} else
db_printf("%jd", mv);
sep1 = " ";
len -= intlen;
p += intlen;
}
error = 0;
goto out;
case CTLTYPE_OPAQUE:
/* TODO: Support struct functions. */
/* FALLTHROUGH */
default:
db_printf("Format:%s Length:%zu Dump:0x",
g_ddb_oid->oid_fmt, len);
while (len-- && (xflag || p < val + 16))
db_printf("%02x", *p++);
if (!xflag && len > 16)
db_printf("...");
error = 0;
goto out;
}
out:
req->oldidx += slen;
return (error);
}
/*
* Avoid setting new sysctl values from the debugger
*/
static int
sysctl_new_ddb(struct sysctl_req *req, void *p, size_t l)
{
if (!req->newptr)
return (0);
/* Changing sysctls from the debugger is currently unsupported */
return (EPERM);
}
/*
* Run a sysctl handler with the DDB oldfunc and newfunc attached.
* Instead of copying any output to a buffer we'll dump it right to
* the console.
*/
static int
db_sysctl(struct sysctl_oid *oidp, int *name, u_int namelen,
void *old, size_t *oldlenp, size_t *retval, int flags)
{
struct sysctl_req req;
int error;
/* Setup the request */
bzero(&req, sizeof req);
req.td = kdb_thread;
req.oldfunc = sysctl_old_ddb;
req.newfunc = sysctl_new_ddb;
req.lock = REQ_UNWIRED;
if (oldlenp) {
req.oldlen = *oldlenp;
}
req.validlen = req.oldlen;
if (old) {
req.oldptr = old;
}
/* Setup our globals for sysctl_old_ddb */
g_ddb_oid = oidp;
g_ddb_sysctl_flags = flags;
g_ddb_sysctl_printed = 0;
error = sysctl_root(0, name, namelen, &req);
/* Reset globals */
g_ddb_oid = NULL;
g_ddb_sysctl_flags = 0;
if (retval) {
if (req.oldptr && req.oldidx > req.validlen)
*retval = req.validlen;
else
*retval = req.oldidx;
}
return (error);
}
/*
* Show a sysctl's name
*/
static void
db_show_oid_name(int *oid, size_t nlen)
{
struct sysctl_oid *oidp;
int qoid[CTL_MAXNAME+2];
int error;
qoid[0] = 0;
memcpy(qoid + 2, oid, nlen * sizeof(int));
qoid[1] = 1;
error = sysctl_find_oid(qoid, nlen + 2, &oidp, NULL, NULL);
if (error)
db_error("sysctl name oid");
error = db_sysctl(oidp, qoid, nlen + 2, NULL, NULL, NULL, 0);
if (error)
db_error("sysctl name");
}
/*
* Check to see if an OID is safe to print from ddb.
*/
static bool
db_oid_safe(const struct sysctl_oid *oidp)
{
for (unsigned int i = 0; i < nitems(db_safe_handlers); ++i) {
if (oidp->oid_handler == db_safe_handlers[i])
return (true);
}
return (false);
}
/*
* Show a sysctl at a specific OID
* Compare to the input handling in show_var from sbin/sysctl/sysctl.c
*/
static int
db_show_oid(struct sysctl_oid *oidp, int *oid, size_t nlen, int flags)
{
int error, xflag, oflag, Nflag, nflag;
size_t len;
xflag = flags & DB_SYSCTL_HEX;
oflag = flags & DB_SYSCTL_OPAQUE;
nflag = flags & DB_SYSCTL_VALUE_ONLY;
Nflag = flags & DB_SYSCTL_NAME_ONLY;
if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_OPAQUE &&
(!xflag && !oflag))
return (0);
if (Nflag) {
db_show_oid_name(oid, nlen);
error = 0;
goto out;
}
if (!nflag) {
db_show_oid_name(oid, nlen);
db_printf(": ");
}
if ((flags & DB_SYSCTL_SAFE_ONLY) && !db_oid_safe(oidp)) {
db_printf("Skipping, unsafe to print while recursing.");
error = 0;
goto out;
}
/* Try once, and ask about the size */
len = 0;
error = db_sysctl(oidp, oid, nlen,
NULL, NULL, &len, flags);
if (error)
goto out;
if (!g_ddb_sysctl_printed)
/* Lie about the size */
error = db_sysctl(oidp, oid, nlen,
(void *) 1, &len, NULL, flags);
out:
db_printf("\n");
return (error);
}
/*
* Show all sysctls under a specific OID
* Compare to sysctl_all from sbin/sysctl/sysctl.c
*/
static int
db_show_sysctl_all(int *oid, size_t len, int flags)
{
struct sysctl_oid *oidp;
int name1[CTL_MAXNAME + 2], name2[CTL_MAXNAME + 2];
size_t l1, l2;
name1[0] = 0;
name1[1] = 2;
l1 = 2;
if (len) {
memcpy(name1+2, oid, len * sizeof(int));
l1 +=len;
} else {
name1[2] = 1;
l1++;
}
for (;;) {
int i, error;
l2 = sizeof(name2);
error = kernel_sysctl(kdb_thread, name1, l1,
name2, &l2, NULL, 0, &l2, 0);
if (error != 0) {
if (error == ENOENT)
return (0);
else
db_error("sysctl(getnext)");
}
l2 /= sizeof(int);
if (l2 < (unsigned int)len)
return (0);
for (i = 0; i < len; i++)
if (name2[i] != oid[i])
return (0);
/* Find the OID in question */
error = sysctl_find_oid(name2, l2, &oidp, NULL, NULL);
if (error)
return (error);
i = db_show_oid(oidp, name2, l2, flags | DB_SYSCTL_SAFE_ONLY);
if (db_pager_quit)
return (0);
memcpy(name1+2, name2, l2 * sizeof(int));
l1 = 2 + l2;
}
}
/*
* Show a sysctl by its user facing string
*/
static int
db_sysctlbyname(char *name, int flags)
{
struct sysctl_oid *oidp;
int oid[CTL_MAXNAME];
int error, nlen;
error = name2oid(name, oid, &nlen, &oidp);
if (error) {
return (error);
}
if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
db_show_sysctl_all(oid, nlen, flags);
} else {
error = db_show_oid(oidp, oid, nlen, flags);
}
return (error);
}
static void
db_sysctl_cmd_usage(void)
{
db_printf(
" sysctl [/Nnox] <sysctl> \n"
" \n"
" <sysctl> The name of the sysctl to show. \n"
" \n"
" Show a sysctl by hooking into SYSCTL_IN and SYSCTL_OUT. \n"
" This will work for most sysctls, but should not be used \n"
" with sysctls that are known to malloc. \n"
" \n"
" While recursing any \"unsafe\" sysctls will be skipped. \n"
" Call sysctl directly on the sysctl to try printing the \n"
" skipped sysctl. This is unsafe and may make the ddb \n"
" session unusable. \n"
" \n"
" Arguments: \n"
" /N Display only the name of the sysctl. \n"
" /n Display only the value of the sysctl. \n"
" /o Display opaque values. \n"
" /x Display the sysctl in hex. \n"
" \n"
"For example: \n"
"sysctl vm.v_free_min \n"
"vn.v_free_min: 12669 \n"
);
}
/*
* Show a specific sysctl similar to sysctl (8).
*/
DB_FUNC(sysctl, db_sysctl_cmd, db_cmd_table, CS_OWN, NULL)
{
char name[TOK_STRING_SIZE];
int error, i, t, flags;
/* Parse the modifiers */
t = db_read_token();
if (t == tSLASH || t == tMINUS) {
t = db_read_token();
if (t != tIDENT) {
db_printf("Bad modifier\n");
error = EINVAL;
goto out;
}
db_strcpy(modif, db_tok_string);
}
else {
db_unread_token(t);
modif[0] = '\0';
}
flags = 0;
for (i = 0; i < nitems(db_sysctl_modifs); i++) {
if (strchr(modif, db_sysctl_modifs[i])) {
flags |= db_sysctl_modif_values[i];
}
}
/* Parse the sysctl names */
t = db_read_token();
if (t != tIDENT) {
db_printf("Need sysctl name\n");
error = EINVAL;
goto out;
}
/* Copy the name into a temporary buffer */
db_strcpy(name, db_tok_string);
/* Ensure there is no trailing cruft */
t = db_read_token();
if (t != tEOL) {
db_printf("Unexpected sysctl argument\n");
error = EINVAL;
goto out;
}
error = db_sysctlbyname(name, flags);
if (error == ENOENT) {
db_printf("unknown oid: '%s'\n", db_tok_string);
goto out;
} else if (error) {
db_printf("%s: error: %d\n", db_tok_string, error);
goto out;
}
out:
/* Ensure we eat all of our text */
db_flush_lex();
if (error == EINVAL) {
db_sysctl_cmd_usage();
}
}
#endif /* DDB */