/* $NetBSD: kern_uidinfo.c,v 1.10 2017/03/18 05:49:56 riastradh 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 __KERNEL_RCSID(0, "$NetBSD: kern_uidinfo.c,v 1.10 2017/03/18 05:49:56 riastradh Exp $"); #include #include #include #include #include #include #include #include #include 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 struct sysctllog *kern_uidinfo_sysctllog; static void sysctl_kern_uidinfo_setup(void) { const struct sysctlnode *rnode, *cnode; 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) { membar_datadep_consumer(); 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; }