kern_sysctl.c

早期freebsd实现

/*-
 * Copyright (c) 1982, 1986, 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Mike Karels at Berkeley Software Design, Inc.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 *	@(#)kern_sysctl.c	8.4 (Berkeley) 4/14/94
 */

/*
 * sysctl system call.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/vnode.h>
#include <sys/unistd.h>
#include <sys/buf.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <vm/vm.h>
#include <sys/sysctl.h>

sysctlfn kern_sysctl;
sysctlfn hw_sysctl;
#ifdef DEBUG
sysctlfn debug_sysctl;
#endif
extern sysctlfn vm_sysctl;
extern sysctlfn fs_sysctl;
extern sysctlfn net_sysctl;
extern sysctlfn cpu_sysctl;

/*
 * Locking and stats
 */
static struct sysctl_lock {
	int	sl_lock;
	int	sl_want;
	int	sl_locked;
} memlock;

struct sysctl_args {
	int	*name;
	u_int	namelen;
	void	*old;
	size_t	*oldlenp;
	void	*new;
	size_t	newlen;
};

int
__sysctl(p, uap, retval)
	struct proc *p;
	register struct sysctl_args *uap;
	int *retval;
{
	int error, dolock = 1;
	u_int savelen, oldlen = 0;
	sysctlfn *fn;
	int name[CTL_MAXNAME];

	if (uap->new != NULL && (error = suser(p->p_ucred, &p->p_acflag)))
		return (error);
	/*
	 * all top-level sysctl names are non-terminal
	 */
	if (uap->namelen > CTL_MAXNAME || uap->namelen < 2)
		return (EINVAL);
	if (error = copyin(uap->name, &name, uap->namelen * sizeof(int)))
		return (error);

	switch (name[0]) {
	case CTL_KERN:
		fn = kern_sysctl;
		if (name[2] != KERN_VNODE)	/* XXX */
			dolock = 0;
		break;
	case CTL_HW:
		fn = hw_sysctl;
		break;
	case CTL_VM:
		fn = vm_sysctl;
		break;
	case CTL_NET:
		fn = net_sysctl;
		break;
#ifdef notyet
	case CTL_FS:
		fn = fs_sysctl;
		break;
#endif
	case CTL_MACHDEP:
		fn = cpu_sysctl;
		break;
#ifdef DEBUG
	case CTL_DEBUG:
		fn = debug_sysctl;
		break;
#endif
	default:
		return (EOPNOTSUPP);
	}

	if (uap->oldlenp &&
	    (error = copyin(uap->oldlenp, &oldlen, sizeof(oldlen))))
		return (error);
	if (uap->old != NULL) {
		if (!useracc(uap->old, oldlen, B_WRITE))
			return (EFAULT);
		while (memlock.sl_lock) {
			memlock.sl_want = 1;
			sleep((caddr_t)&memlock, PRIBIO+1);
			memlock.sl_locked++;
		}
		memlock.sl_lock = 1;
		if (dolock)
			vslock(uap->old, oldlen);
		savelen = oldlen;
	}
	error = (*fn)(name + 1, uap->namelen - 1, uap->old, &oldlen,
	    uap->new, uap->newlen, p);
	if (uap->old != NULL) {
		if (dolock)
			vsunlock(uap->old, savelen, B_WRITE);
		memlock.sl_lock = 0;
		if (memlock.sl_want) {
			memlock.sl_want = 0;
			wakeup((caddr_t)&memlock);
		}
	}
	if (error)
		return (error);
	if (uap->oldlenp)
		error = copyout(&oldlen, uap->oldlenp, sizeof(oldlen));
	*retval = oldlen;
	return (0);
}

/*
 * Attributes stored in the kernel.
 */
char hostname[MAXHOSTNAMELEN];
int hostnamelen;
long hostid;
int securelevel;

/*
 * kernel related system variables.
 */
kern_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
	int *name;
	u_int namelen;
	void *oldp;
	size_t *oldlenp;
	void *newp;
	size_t newlen;
	struct proc *p;
{
	int error, level, inthostid;
	extern char ostype[], osrelease[], version[];

	/* all sysctl names at this level are terminal */
	if (namelen != 1 && !(name[0] == KERN_PROC || name[0] == KERN_PROF))
		return (ENOTDIR);		/* overloaded */

	switch (name[0]) {
	case KERN_OSTYPE:
		return (sysctl_rdstring(oldp, oldlenp, newp, ostype));
	case KERN_OSRELEASE:
		return (sysctl_rdstring(oldp, oldlenp, newp, osrelease));
	case KERN_OSREV:
		return (sysctl_rdint(oldp, oldlenp, newp, BSD));
	case KERN_VERSION:
		return (sysctl_rdstring(oldp, oldlenp, newp, version));
	case KERN_MAXVNODES:
		return(sysctl_int(oldp, oldlenp, newp, newlen, &desiredvnodes));
	case KERN_MAXPROC:
		return (sysctl_int(oldp, oldlenp, newp, newlen, &maxproc));
	case KERN_MAXFILES:
		return (sysctl_int(oldp, oldlenp, newp, newlen, &maxfiles));
	case KERN_ARGMAX:
		return (sysctl_rdint(oldp, oldlenp, newp, ARG_MAX));
	case KERN_SECURELVL:
		level = securelevel;
		if ((error = sysctl_int(oldp, oldlenp, newp, newlen, &level)) ||
		    newp == NULL)
			return (error);
		if (level < securelevel && p->p_pid != 1)
			return (EPERM);
		securelevel = level;
		return (0);
	case KERN_HOSTNAME:
		error = sysctl_string(oldp, oldlenp, newp, newlen,
		    hostname, sizeof(hostname));
		if (newp && !error)
			hostnamelen = newlen;
		return (error);
	case KERN_HOSTID:
		inthostid = hostid;  /* XXX assumes sizeof long <= sizeof int */
		error =  sysctl_int(oldp, oldlenp, newp, newlen, &inthostid);
		hostid = inthostid;
		return (error);
	case KERN_CLOCKRATE:
		return (sysctl_clockrate(oldp, oldlenp));
	case KERN_BOOTTIME:
		return (sysctl_rdstruct(oldp, oldlenp, newp, &boottime,
		    sizeof(struct timeval)));
	case KERN_VNODE:
		return (sysctl_vnode(oldp, oldlenp));
	case KERN_PROC:
		return (sysctl_doproc(name + 1, namelen - 1, oldp, oldlenp));
	case KERN_FILE:
		return (sysctl_file(oldp, oldlenp));
#ifdef GPROF
	case KERN_PROF:
		return (sysctl_doprof(name + 1, namelen - 1, oldp, oldlenp,
		    newp, newlen));
#endif
	case KERN_POSIX1:
		return (sysctl_rdint(oldp, oldlenp, newp, _POSIX_VERSION));
	case KERN_NGROUPS:
		return (sysctl_rdint(oldp, oldlenp, newp, NGROUPS_MAX));
	case KERN_JOB_CONTROL:
		return (sysctl_rdint(oldp, oldlenp, newp, 1));
	case KERN_SAVED_IDS:
#ifdef _POSIX_SAVED_IDS
		return (sysctl_rdint(oldp, oldlenp, newp, 1));
#else
		return (sysctl_rdint(oldp, oldlenp, newp, 0));
#endif
	default:
		return (EOPNOTSUPP);
	}
	/* NOTREACHED */
}

/*
 * hardware related system variables.
 */
hw_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
	int *name;
	u_int namelen;
	void *oldp;
	size_t *oldlenp;
	void *newp;
	size_t newlen;
	struct proc *p;
{
	extern char machine[], cpu_model[];

	/* all sysctl names at this level are terminal */
	if (namelen != 1)
		return (ENOTDIR);		/* overloaded */

	switch (name[0]) {
	case HW_MACHINE:
		return (sysctl_rdstring(oldp, oldlenp, newp, machine));
	case HW_MODEL:
		return (sysctl_rdstring(oldp, oldlenp, newp, cpu_model));
	case HW_NCPU:
		return (sysctl_rdint(oldp, oldlenp, newp, 1));	/* XXX */
	case HW_BYTEORDER:
		return (sysctl_rdint(oldp, oldlenp, newp, BYTE_ORDER));
	case HW_PHYSMEM:
		return (sysctl_rdint(oldp, oldlenp, newp, ctob(physmem)));
	case HW_USERMEM:
		return (sysctl_rdint(oldp, oldlenp, newp,
		    ctob(physmem - cnt.v_wire_count)));
	case HW_PAGESIZE:
		return (sysctl_rdint(oldp, oldlenp, newp, PAGE_SIZE));
	default:
		return (EOPNOTSUPP);
	}
	/* NOTREACHED */
}

#ifdef DEBUG
/*
 * Debugging related system variables.
 */
struct ctldebug debug0, debug1, debug2, debug3, debug4;
struct ctldebug debug5, debug6, debug7, debug8, debug9;
struct ctldebug debug10, debug11, debug12, debug13, debug14;
struct ctldebug debug15, debug16, debug17, debug18, debug19;
static struct ctldebug *debugvars[CTL_DEBUG_MAXID] = {
	&debug0, &debug1, &debug2, &debug3, &debug4,
	&debug5, &debug6, &debug7, &debug8, &debug9,
	&debug10, &debug11, &debug12, &debug13, &debug14,
	&debug15, &debug16, &debug17, &debug18, &debug19,
};
int
debug_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
	int *name;
	u_int namelen;
	void *oldp;
	size_t *oldlenp;
	void *newp;
	size_t newlen;
	struct proc *p;
{
	struct ctldebug *cdp;

	/* all sysctl names at this level are name and field */
	if (namelen != 2)
		return (ENOTDIR);		/* overloaded */
	cdp = debugvars[name[0]];
	if (cdp->debugname == 0)
		return (EOPNOTSUPP);
	switch (name[1]) {
	case CTL_DEBUG_NAME:
		return (sysctl_rdstring(oldp, oldlenp, newp, cdp->debugname));
	case CTL_DEBUG_VALUE:
		return (sysctl_int(oldp, oldlenp, newp, newlen, cdp->debugvar));
	default:
		return (EOPNOTSUPP);
	}
	/* NOTREACHED */
}
#endif /* DEBUG */

/*
 * Validate parameters and get old / set new parameters
 * for an integer-valued sysctl function.
 */
sysctl_int(oldp, oldlenp, newp, newlen, valp)
	void *oldp;
	size_t *oldlenp;
	void *newp;
	size_t newlen;
	int *valp;
{
	int error = 0;

	if (oldp && *oldlenp < sizeof(int))
		return (ENOMEM);
	if (newp && newlen != sizeof(int))
		return (EINVAL);
	*oldlenp = sizeof(int);
	if (oldp)
		error = copyout(valp, oldp, sizeof(int));
	if (error == 0 && newp)
		error = copyin(newp, valp, sizeof(int));
	return (error);
}

/*
 * As above, but read-only.
 */
sysctl_rdint(oldp, oldlenp, newp, val)
	void *oldp;
	size_t *oldlenp;
	void *newp;
	int val;
{
	int error = 0;

	if (oldp && *oldlenp < sizeof(int))
		return (ENOMEM);
	if (newp)
		return (EPERM);