2 * Copyright (c) 2011 The FreeBSD Foundation
5 * This software was developed by Edward Tomasz Napierala under sponsorship
6 * from the FreeBSD Foundation.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * Processes may set login class name using setloginclass(2). This
34 * is usually done through call to setusercontext(3), by programs
35 * such as login(1), based on information from master.passwd(5). Kernel
36 * uses this information to enforce per-class resource limits. Current
37 * login class can be determined using id(1). Login class is inherited
38 * from the parent process during fork(2). If not set, it defaults
41 * Code in this file implements setloginclass(2) and getloginclass(2)
42 * system calls, and maintains class name storage and retrieval.
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
48 #include <sys/param.h>
49 #include <sys/eventhandler.h>
50 #include <sys/kernel.h>
52 #include <sys/loginclass.h>
53 #include <sys/malloc.h>
54 #include <sys/types.h>
57 #include <sys/queue.h>
58 #include <sys/racct.h>
59 #include <sys/refcount.h>
60 #include <sys/rwlock.h>
61 #include <sys/sysproto.h>
62 #include <sys/systm.h>
64 static MALLOC_DEFINE(M_LOGINCLASS, "loginclass", "loginclass structures");
66 LIST_HEAD(, loginclass) loginclasses;
69 * Lock protecting loginclasses list.
71 static struct rwlock loginclasses_lock;
72 RW_SYSINIT(loginclasses_init, &loginclasses_lock, "loginclasses lock");
75 loginclass_hold(struct loginclass *lc)
78 refcount_acquire(&lc->lc_refcount);
82 loginclass_free(struct loginclass *lc)
86 old = lc->lc_refcount;
87 if (old > 1 && atomic_cmpset_int(&lc->lc_refcount, old, old - 1))
90 rw_wlock(&loginclasses_lock);
91 if (!refcount_release(&lc->lc_refcount)) {
92 rw_wunlock(&loginclasses_lock);
96 racct_destroy(&lc->lc_racct);
97 LIST_REMOVE(lc, lc_next);
98 rw_wunlock(&loginclasses_lock);
100 free(lc, M_LOGINCLASS);
104 * Look up a loginclass struct for the parameter name.
105 * loginclasses_lock must be locked.
106 * Increase refcount on loginclass struct returned.
108 static struct loginclass *
109 loginclass_lookup(const char *name)
111 struct loginclass *lc;
113 rw_assert(&loginclasses_lock, RA_LOCKED);
114 LIST_FOREACH(lc, &loginclasses, lc_next)
115 if (strcmp(name, lc->lc_name) == 0) {
124 * Return loginclass structure with a corresponding name. Not
125 * performance critical, as it's used mainly by setloginclass(2),
126 * which happens once per login session. Caller has to use
127 * loginclass_free() on the returned value when it's no longer
131 loginclass_find(const char *name)
133 struct loginclass *lc, *new_lc;
135 if (name[0] == '\0' || strlen(name) >= MAXLOGNAME)
138 rw_rlock(&loginclasses_lock);
139 lc = loginclass_lookup(name);
140 rw_runlock(&loginclasses_lock);
144 new_lc = malloc(sizeof(*new_lc), M_LOGINCLASS, M_ZERO | M_WAITOK);
145 racct_create(&new_lc->lc_racct);
146 refcount_init(&new_lc->lc_refcount, 1);
147 strcpy(new_lc->lc_name, name);
149 rw_wlock(&loginclasses_lock);
151 * There's a chance someone created our loginclass while we
152 * were in malloc and not holding the lock, so we have to
153 * make sure we don't insert a duplicate loginclass.
155 if ((lc = loginclass_lookup(name)) == NULL) {
156 LIST_INSERT_HEAD(&loginclasses, new_lc, lc_next);
157 rw_wunlock(&loginclasses_lock);
160 rw_wunlock(&loginclasses_lock);
161 racct_destroy(&new_lc->lc_racct);
162 free(new_lc, M_LOGINCLASS);
169 * Get login class name.
171 #ifndef _SYS_SYSPROTO_H_
172 struct getloginclass_args {
179 sys_getloginclass(struct thread *td, struct getloginclass_args *uap)
181 struct loginclass *lc;
184 lc = td->td_ucred->cr_loginclass;
185 lcnamelen = strlen(lc->lc_name) + 1;
186 if (lcnamelen > uap->namelen)
188 return (copyout(lc->lc_name, uap->namebuf, lcnamelen));
192 * Set login class name.
194 #ifndef _SYS_SYSPROTO_H_
195 struct setloginclass_args {
201 sys_setloginclass(struct thread *td, struct setloginclass_args *uap)
203 struct proc *p = td->td_proc;
205 char lcname[MAXLOGNAME];
206 struct loginclass *newlc;
207 struct ucred *newcred, *oldcred;
209 error = priv_check(td, PRIV_PROC_SETLOGINCLASS);
212 error = copyinstr(uap->namebuf, lcname, sizeof(lcname), NULL);
216 newlc = loginclass_find(lcname);
222 oldcred = crcopysafe(p, newcred);
223 newcred->cr_loginclass = newlc;
224 proc_set_cred(p, newcred);
227 racct_proc_ucred_changed(p, oldcred, newcred);
229 loginclass_free(oldcred->cr_loginclass);
236 loginclass_racct_foreach(void (*callback)(struct racct *racct,
237 void *arg2, void *arg3), void (*pre)(void), void (*post)(void),
238 void *arg2, void *arg3)
240 struct loginclass *lc;
242 rw_rlock(&loginclasses_lock);
245 LIST_FOREACH(lc, &loginclasses, lc_next)
246 (callback)(lc->lc_racct, arg2, arg3);
249 rw_runlock(&loginclasses_lock);