| 1 | /* $NetBSD: kern_uidinfo.c,v 1.8 2013/03/10 17:55:42 pooka Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 1982, 1986, 1991, 1993 |
| 5 | * The Regents of the University of California. All rights reserved. |
| 6 | * (c) UNIX System Laboratories, Inc. |
| 7 | * All or some portions of this file are derived from material licensed |
| 8 | * to the University of California by American Telephone and Telegraph |
| 9 | * Co. or Unix System Laboratories, Inc. and are reproduced herein with |
| 10 | * the permission of UNIX System Laboratories, Inc. |
| 11 | * |
| 12 | * Redistribution and use in source and binary forms, with or without |
| 13 | * modification, are permitted provided that the following conditions |
| 14 | * are met: |
| 15 | * 1. Redistributions of source code must retain the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer. |
| 17 | * 2. Redistributions in binary form must reproduce the above copyright |
| 18 | * notice, this list of conditions and the following disclaimer in the |
| 19 | * documentation and/or other materials provided with the distribution. |
| 20 | * 3. Neither the name of the University nor the names of its contributors |
| 21 | * may be used to endorse or promote products derived from this software |
| 22 | * without specific prior written permission. |
| 23 | * |
| 24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 34 | * SUCH DAMAGE. |
| 35 | */ |
| 36 | |
| 37 | #include <sys/cdefs.h> |
| 38 | __KERNEL_RCSID(0, "$NetBSD: kern_uidinfo.c,v 1.8 2013/03/10 17:55:42 pooka Exp $" ); |
| 39 | |
| 40 | #include <sys/param.h> |
| 41 | #include <sys/systm.h> |
| 42 | #include <sys/kmem.h> |
| 43 | #include <sys/proc.h> |
| 44 | #include <sys/atomic.h> |
| 45 | #include <sys/uidinfo.h> |
| 46 | #include <sys/sysctl.h> |
| 47 | #include <sys/kauth.h> |
| 48 | #include <sys/cpu.h> |
| 49 | |
| 50 | static SLIST_HEAD(uihashhead, uidinfo) *uihashtbl; |
| 51 | static u_long uihash; |
| 52 | |
| 53 | #define UIHASH(uid) (&uihashtbl[(uid) & uihash]) |
| 54 | |
| 55 | static int |
| 56 | sysctl_kern_uidinfo_cnt(SYSCTLFN_ARGS) |
| 57 | { |
| 58 | static const struct { |
| 59 | const char *name; |
| 60 | u_int value; |
| 61 | } nv[] = { |
| 62 | #define _MEM(n) { # n, offsetof(struct uidinfo, ui_ ## n) } |
| 63 | _MEM(proccnt), |
| 64 | _MEM(lwpcnt), |
| 65 | _MEM(lockcnt), |
| 66 | _MEM(sbsize), |
| 67 | #undef _MEM |
| 68 | }; |
| 69 | |
| 70 | for (size_t i = 0; i < __arraycount(nv); i++) |
| 71 | if (strcmp(nv[i].name, rnode->sysctl_name) == 0) { |
| 72 | uint64_t cnt; |
| 73 | struct sysctlnode node = *rnode; |
| 74 | struct uidinfo *uip; |
| 75 | |
| 76 | node.sysctl_data = &cnt; |
| 77 | uip = uid_find(kauth_cred_geteuid(l->l_cred)); |
| 78 | |
| 79 | *(uint64_t *)node.sysctl_data = |
| 80 | *(u_long *)((char *)uip + nv[i].value); |
| 81 | |
| 82 | return sysctl_lookup(SYSCTLFN_CALL(&node)); |
| 83 | } |
| 84 | |
| 85 | return EINVAL; |
| 86 | } |
| 87 | |
| 88 | static struct sysctllog *kern_uidinfo_sysctllog; |
| 89 | |
| 90 | static void |
| 91 | sysctl_kern_uidinfo_setup(void) |
| 92 | { |
| 93 | const struct sysctlnode *rnode, *cnode; |
| 94 | |
| 95 | sysctl_createv(&kern_uidinfo_sysctllog, 0, NULL, &rnode, |
| 96 | CTLFLAG_PERMANENT, |
| 97 | CTLTYPE_NODE, "uidinfo" , |
| 98 | SYSCTL_DESCR("Resource usage per uid" ), |
| 99 | NULL, 0, NULL, 0, |
| 100 | CTL_KERN, CTL_CREATE, CTL_EOL); |
| 101 | |
| 102 | sysctl_createv(&kern_uidinfo_sysctllog, 0, &rnode, &cnode, |
| 103 | CTLFLAG_PERMANENT, |
| 104 | CTLTYPE_QUAD, "proccnt" , |
| 105 | SYSCTL_DESCR("Number of processes for the current user" ), |
| 106 | sysctl_kern_uidinfo_cnt, 0, NULL, 0, |
| 107 | CTL_CREATE, CTL_EOL); |
| 108 | sysctl_createv(&kern_uidinfo_sysctllog, 0, &rnode, &cnode, |
| 109 | CTLFLAG_PERMANENT, |
| 110 | CTLTYPE_QUAD, "lwpcnt" , |
| 111 | SYSCTL_DESCR("Number of lwps for the current user" ), |
| 112 | sysctl_kern_uidinfo_cnt, 0, NULL, 0, |
| 113 | CTL_CREATE, CTL_EOL); |
| 114 | sysctl_createv(&kern_uidinfo_sysctllog, 0, &rnode, &cnode, |
| 115 | CTLFLAG_PERMANENT, |
| 116 | CTLTYPE_QUAD, "lockcnt" , |
| 117 | SYSCTL_DESCR("Number of locks for the current user" ), |
| 118 | sysctl_kern_uidinfo_cnt, 0, NULL, 0, |
| 119 | CTL_CREATE, CTL_EOL); |
| 120 | sysctl_createv(&kern_uidinfo_sysctllog, 0, &rnode, &cnode, |
| 121 | CTLFLAG_PERMANENT, |
| 122 | CTLTYPE_QUAD, "sbsize" , |
| 123 | SYSCTL_DESCR("Socket buffers used for the current user" ), |
| 124 | sysctl_kern_uidinfo_cnt, 0, NULL, 0, |
| 125 | CTL_CREATE, CTL_EOL); |
| 126 | } |
| 127 | |
| 128 | void |
| 129 | uid_init(void) |
| 130 | { |
| 131 | |
| 132 | /* |
| 133 | * In case of MP system, SLIST_FOREACH would force a cache line |
| 134 | * write-back for every modified 'uidinfo', thus we try to keep the |
| 135 | * lists short. |
| 136 | */ |
| 137 | const u_int uihash_sz = (maxcpus > 1 ? 1024 : 64); |
| 138 | |
| 139 | uihashtbl = hashinit(uihash_sz, HASH_SLIST, true, &uihash); |
| 140 | |
| 141 | /* |
| 142 | * Ensure that uid 0 is always in the user hash table, as |
| 143 | * sbreserve() expects it available from interrupt context. |
| 144 | */ |
| 145 | (void)uid_find(0); |
| 146 | sysctl_kern_uidinfo_setup(); |
| 147 | } |
| 148 | |
| 149 | struct uidinfo * |
| 150 | uid_find(uid_t uid) |
| 151 | { |
| 152 | struct uidinfo *uip, *uip_first, *newuip; |
| 153 | struct uihashhead *uipp; |
| 154 | |
| 155 | uipp = UIHASH(uid); |
| 156 | newuip = NULL; |
| 157 | |
| 158 | /* |
| 159 | * To make insertion atomic, abstraction of SLIST will be violated. |
| 160 | */ |
| 161 | uip_first = uipp->slh_first; |
| 162 | again: |
| 163 | SLIST_FOREACH(uip, uipp, ui_hash) { |
| 164 | if (uip->ui_uid != uid) |
| 165 | continue; |
| 166 | if (newuip != NULL) |
| 167 | kmem_free(newuip, sizeof(*newuip)); |
| 168 | return uip; |
| 169 | } |
| 170 | if (newuip == NULL) |
| 171 | newuip = kmem_zalloc(sizeof(*newuip), KM_SLEEP); |
| 172 | newuip->ui_uid = uid; |
| 173 | |
| 174 | /* |
| 175 | * If atomic insert is unsuccessful, another thread might be |
| 176 | * allocated this 'uid', thus full re-check is needed. |
| 177 | */ |
| 178 | newuip->ui_hash.sle_next = uip_first; |
| 179 | membar_producer(); |
| 180 | uip = atomic_cas_ptr(&uipp->slh_first, uip_first, newuip); |
| 181 | if (uip != uip_first) { |
| 182 | uip_first = uip; |
| 183 | goto again; |
| 184 | } |
| 185 | |
| 186 | return newuip; |
| 187 | } |
| 188 | |
| 189 | /* |
| 190 | * Change the count associated with number of processes |
| 191 | * a given user is using. |
| 192 | */ |
| 193 | int |
| 194 | chgproccnt(uid_t uid, int diff) |
| 195 | { |
| 196 | struct uidinfo *uip; |
| 197 | long proccnt; |
| 198 | |
| 199 | uip = uid_find(uid); |
| 200 | proccnt = atomic_add_long_nv(&uip->ui_proccnt, diff); |
| 201 | KASSERT(proccnt >= 0); |
| 202 | return proccnt; |
| 203 | } |
| 204 | |
| 205 | /* |
| 206 | * Change the count associated with number of lwps |
| 207 | * a given user is using. |
| 208 | */ |
| 209 | int |
| 210 | chglwpcnt(uid_t uid, int diff) |
| 211 | { |
| 212 | struct uidinfo *uip; |
| 213 | long lwpcnt; |
| 214 | |
| 215 | uip = uid_find(uid); |
| 216 | lwpcnt = atomic_add_long_nv(&uip->ui_lwpcnt, diff); |
| 217 | KASSERT(lwpcnt >= 0); |
| 218 | return lwpcnt; |
| 219 | } |
| 220 | |
| 221 | int |
| 222 | chgsbsize(struct uidinfo *uip, u_long *hiwat, u_long to, rlim_t xmax) |
| 223 | { |
| 224 | rlim_t nsb; |
| 225 | const long diff = to - *hiwat; |
| 226 | |
| 227 | nsb = (rlim_t)atomic_add_long_nv((long *)&uip->ui_sbsize, diff); |
| 228 | if (diff > 0 && nsb > xmax) { |
| 229 | atomic_add_long((long *)&uip->ui_sbsize, -diff); |
| 230 | return 0; |
| 231 | } |
| 232 | *hiwat = to; |
| 233 | return 1; |
| 234 | } |
| 235 | |