NetBSD/sys/kern/kern_uidinfo.c

235 lines
6.6 KiB
C

/* $NetBSD: kern_uidinfo.c,v 1.7 2012/06/09 02:55:32 christos Exp $ */
/*-
* Copyright (c) 1982, 1986, 1991, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, 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. 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_uidinfo.c,v 1.7 2012/06/09 02:55:32 christos Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kmem.h>
#include <sys/proc.h>
#include <sys/atomic.h>
#include <sys/uidinfo.h>
#include <sys/sysctl.h>
#include <sys/kauth.h>
#include <sys/cpu.h>
static SLIST_HEAD(uihashhead, uidinfo) *uihashtbl;
static u_long uihash;
#define UIHASH(uid) (&uihashtbl[(uid) & uihash])
static int
sysctl_kern_uidinfo_cnt(SYSCTLFN_ARGS)
{
static const struct {
const char *name;
u_int value;
} nv[] = {
#define _MEM(n) { # n, offsetof(struct uidinfo, ui_ ## n) }
_MEM(proccnt),
_MEM(lwpcnt),
_MEM(lockcnt),
_MEM(sbsize),
#undef _MEM
};
for (size_t i = 0; i < __arraycount(nv); i++)
if (strcmp(nv[i].name, rnode->sysctl_name) == 0) {
uint64_t cnt;
struct sysctlnode node = *rnode;
struct uidinfo *uip;
node.sysctl_data = &cnt;
uip = uid_find(kauth_cred_geteuid(l->l_cred));
*(uint64_t *)node.sysctl_data =
*(u_long *)((char *)uip + nv[i].value);
return sysctl_lookup(SYSCTLFN_CALL(&node));
}
return EINVAL;
}
static void
sysctl_kern_uidinfo_setup(void)
{
const struct sysctlnode *rnode, *cnode;
struct sysctllog *kern_uidinfo_sysctllog;
kern_uidinfo_sysctllog = NULL;
sysctl_createv(&kern_uidinfo_sysctllog, 0, NULL, &rnode,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "uidinfo",
SYSCTL_DESCR("Resource usage per uid"),
NULL, 0, NULL, 0,
CTL_KERN, CTL_CREATE, CTL_EOL);
sysctl_createv(&kern_uidinfo_sysctllog, 0, &rnode, &cnode,
CTLFLAG_PERMANENT,
CTLTYPE_QUAD, "proccnt",
SYSCTL_DESCR("Number of processes for the current user"),
sysctl_kern_uidinfo_cnt, 0, NULL, 0,
CTL_CREATE, CTL_EOL);
sysctl_createv(&kern_uidinfo_sysctllog, 0, &rnode, &cnode,
CTLFLAG_PERMANENT,
CTLTYPE_QUAD, "lwpcnt",
SYSCTL_DESCR("Number of lwps for the current user"),
sysctl_kern_uidinfo_cnt, 0, NULL, 0,
CTL_CREATE, CTL_EOL);
sysctl_createv(&kern_uidinfo_sysctllog, 0, &rnode, &cnode,
CTLFLAG_PERMANENT,
CTLTYPE_QUAD, "lockcnt",
SYSCTL_DESCR("Number of locks for the current user"),
sysctl_kern_uidinfo_cnt, 0, NULL, 0,
CTL_CREATE, CTL_EOL);
sysctl_createv(&kern_uidinfo_sysctllog, 0, &rnode, &cnode,
CTLFLAG_PERMANENT,
CTLTYPE_QUAD, "sbsize",
SYSCTL_DESCR("Socket buffers used for the current user"),
sysctl_kern_uidinfo_cnt, 0, NULL, 0,
CTL_CREATE, CTL_EOL);
}
void
uid_init(void)
{
/*
* In case of MP system, SLIST_FOREACH would force a cache line
* write-back for every modified 'uidinfo', thus we try to keep the
* lists short.
*/
const u_int uihash_sz = (maxcpus > 1 ? 1024 : 64);
uihashtbl = hashinit(uihash_sz, HASH_SLIST, true, &uihash);
/*
* Ensure that uid 0 is always in the user hash table, as
* sbreserve() expects it available from interrupt context.
*/
(void)uid_find(0);
sysctl_kern_uidinfo_setup();
}
struct uidinfo *
uid_find(uid_t uid)
{
struct uidinfo *uip, *uip_first, *newuip;
struct uihashhead *uipp;
uipp = UIHASH(uid);
newuip = NULL;
/*
* To make insertion atomic, abstraction of SLIST will be violated.
*/
uip_first = uipp->slh_first;
again:
SLIST_FOREACH(uip, uipp, ui_hash) {
if (uip->ui_uid != uid)
continue;
if (newuip != NULL)
kmem_free(newuip, sizeof(*newuip));
return uip;
}
if (newuip == NULL)
newuip = kmem_zalloc(sizeof(*newuip), KM_SLEEP);
newuip->ui_uid = uid;
/*
* If atomic insert is unsuccessful, another thread might be
* allocated this 'uid', thus full re-check is needed.
*/
newuip->ui_hash.sle_next = uip_first;
membar_producer();
uip = atomic_cas_ptr(&uipp->slh_first, uip_first, newuip);
if (uip != uip_first) {
uip_first = uip;
goto again;
}
return newuip;
}
/*
* Change the count associated with number of processes
* a given user is using.
*/
int
chgproccnt(uid_t uid, int diff)
{
struct uidinfo *uip;
long proccnt;
uip = uid_find(uid);
proccnt = atomic_add_long_nv(&uip->ui_proccnt, diff);
KASSERT(proccnt >= 0);
return proccnt;
}
/*
* Change the count associated with number of lwps
* a given user is using.
*/
int
chglwpcnt(uid_t uid, int diff)
{
struct uidinfo *uip;
long lwpcnt;
uip = uid_find(uid);
lwpcnt = atomic_add_long_nv(&uip->ui_lwpcnt, diff);
KASSERT(lwpcnt >= 0);
return lwpcnt;
}
int
chgsbsize(struct uidinfo *uip, u_long *hiwat, u_long to, rlim_t xmax)
{
rlim_t nsb;
const long diff = to - *hiwat;
nsb = (rlim_t)atomic_add_long_nv((long *)&uip->ui_sbsize, diff);
if (diff > 0 && nsb > xmax) {
atomic_add_long((long *)&uip->ui_sbsize, -diff);
return 0;
}
*hiwat = to;
return 1;
}