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 | |