xref: /freebsd/sys/kern/kern_resource.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
1 /*-
2  * Copyright (c) 1982, 1986, 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * (c) UNIX System Laboratories, Inc.
5  * All or some portions of this file are derived from material licensed
6  * to the University of California by American Telephone and Telegraph
7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8  * the permission of UNIX System Laboratories, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	@(#)kern_resource.c	8.5 (Berkeley) 1/21/94
39  * $FreeBSD$
40  */
41 
42 #include "opt_compat.h"
43 #include "opt_rlimit.h"
44 
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/sysproto.h>
48 #include <sys/file.h>
49 #include <sys/kernel.h>
50 #include <sys/resourcevar.h>
51 #include <sys/malloc.h>
52 #include <sys/proc.h>
53 #include <sys/time.h>
54 
55 #include <vm/vm.h>
56 #include <vm/vm_param.h>
57 #include <sys/lock.h>
58 #include <vm/pmap.h>
59 #include <vm/vm_map.h>
60 
61 static int donice __P((struct proc *curp, struct proc *chgp, int n));
62 /* dosetrlimit non-static:  Needed by SysVR4 emulator */
63 int dosetrlimit __P((struct proc *p, u_int which, struct rlimit *limp));
64 
65 static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures");
66 #define	UIHASH(uid)	(&uihashtbl[(uid) & uihash])
67 static struct mtx uihashtbl_mtx;
68 static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
69 static u_long uihash;		/* size of hash table - 1 */
70 
71 static struct uidinfo	*uicreate __P((uid_t uid));
72 static struct uidinfo	*uilookup __P((uid_t uid));
73 
74 /*
75  * Resource controls and accounting.
76  */
77 
78 #ifndef _SYS_SYSPROTO_H_
79 struct getpriority_args {
80 	int	which;
81 	int	who;
82 };
83 #endif
84 int
85 getpriority(curp, uap)
86 	struct proc *curp;
87 	register struct getpriority_args *uap;
88 {
89 	register struct proc *p;
90 	register int low = PRIO_MAX + 1;
91 
92 	switch (uap->which) {
93 
94 	case PRIO_PROCESS:
95 		if (uap->who == 0)
96 			p = curp;
97 		else
98 			p = pfind(uap->who);
99 		if (p == 0)
100 			break;
101 		if (p_can(curp, p, P_CAN_SEE, NULL))
102 			break;
103 		low = p->p_nice;
104 		break;
105 
106 	case PRIO_PGRP: {
107 		register struct pgrp *pg;
108 
109 		if (uap->who == 0)
110 			pg = curp->p_pgrp;
111 		else if ((pg = pgfind(uap->who)) == NULL)
112 			break;
113 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
114 			if (!p_can(curp, p, P_CAN_SEE, NULL) && p->p_nice < low)
115 				low = p->p_nice;
116 		}
117 		break;
118 	}
119 
120 	case PRIO_USER:
121 		if (uap->who == 0)
122 			uap->who = curp->p_ucred->cr_uid;
123 		lockmgr(&allproc_lock, LK_SHARED, NULL, CURPROC);
124 		LIST_FOREACH(p, &allproc, p_list)
125 			if (!p_can(curp, p, P_CAN_SEE, NULL) &&
126 			    p->p_ucred->cr_uid == uap->who &&
127 			    p->p_nice < low)
128 				low = p->p_nice;
129 		lockmgr(&allproc_lock, LK_RELEASE, NULL, CURPROC);
130 		break;
131 
132 	default:
133 		return (EINVAL);
134 	}
135 	if (low == PRIO_MAX + 1)
136 		return (ESRCH);
137 	curp->p_retval[0] = low;
138 	return (0);
139 }
140 
141 #ifndef _SYS_SYSPROTO_H_
142 struct setpriority_args {
143 	int	which;
144 	int	who;
145 	int	prio;
146 };
147 #endif
148 /* ARGSUSED */
149 int
150 setpriority(curp, uap)
151 	struct proc *curp;
152 	register struct setpriority_args *uap;
153 {
154 	register struct proc *p;
155 	int found = 0, error = 0;
156 
157 	switch (uap->which) {
158 
159 	case PRIO_PROCESS:
160 		if (uap->who == 0)
161 			p = curp;
162 		else
163 			p = pfind(uap->who);
164 		if (p == 0)
165 			break;
166 		if (p_can(curp, p, P_CAN_SEE, NULL))
167 			break;
168 		error = donice(curp, p, uap->prio);
169 		found++;
170 		break;
171 
172 	case PRIO_PGRP: {
173 		register struct pgrp *pg;
174 
175 		if (uap->who == 0)
176 			pg = curp->p_pgrp;
177 		else if ((pg = pgfind(uap->who)) == NULL)
178 			break;
179 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
180 			if (!p_can(curp, p, P_CAN_SEE, NULL)) {
181 				error = donice(curp, p, uap->prio);
182 				found++;
183 			}
184 		}
185 		break;
186 	}
187 
188 	case PRIO_USER:
189 		if (uap->who == 0)
190 			uap->who = curp->p_ucred->cr_uid;
191 		lockmgr(&allproc_lock, LK_SHARED, NULL, CURPROC);
192 		LIST_FOREACH(p, &allproc, p_list)
193 			if (p->p_ucred->cr_uid == uap->who &&
194 			    !p_can(curp, p, P_CAN_SEE, NULL)) {
195 				error = donice(curp, p, uap->prio);
196 				found++;
197 			}
198 		lockmgr(&allproc_lock, LK_RELEASE, NULL, CURPROC);
199 		break;
200 
201 	default:
202 		return (EINVAL);
203 	}
204 	if (found == 0)
205 		return (ESRCH);
206 	return (error);
207 }
208 
209 static int
210 donice(curp, chgp, n)
211 	register struct proc *curp, *chgp;
212 	register int n;
213 {
214 	int	error;
215 
216 	if ((error = p_can(curp, chgp, P_CAN_SCHED, NULL)))
217 		return (error);
218 	if (n > PRIO_MAX)
219 		n = PRIO_MAX;
220 	if (n < PRIO_MIN)
221 		n = PRIO_MIN;
222 	if (n < chgp->p_nice && suser(curp))
223 		return (EACCES);
224 	chgp->p_nice = n;
225 	(void)resetpriority(chgp);
226 	return (0);
227 }
228 
229 /* rtprio system call */
230 #ifndef _SYS_SYSPROTO_H_
231 struct rtprio_args {
232 	int		function;
233 	pid_t		pid;
234 	struct rtprio	*rtp;
235 };
236 #endif
237 
238 /*
239  * Set realtime priority
240  */
241 
242 /* ARGSUSED */
243 int
244 rtprio(curp, uap)
245 	struct proc *curp;
246 	register struct rtprio_args *uap;
247 {
248 	register struct proc *p;
249 	struct rtprio rtp;
250 	int error;
251 
252 	error = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
253 	if (error)
254 		return (error);
255 
256 	if (uap->pid == 0)
257 		p = curp;
258 	else
259 		p = pfind(uap->pid);
260 
261 	if (p == 0)
262 		return (ESRCH);
263 
264 	switch (uap->function) {
265 	case RTP_LOOKUP:
266 		return (copyout(&p->p_rtprio, uap->rtp, sizeof(struct rtprio)));
267 	case RTP_SET:
268 		if ((error = p_can(curp, p, P_CAN_SCHED, NULL)))
269 		        return (error);
270 		/* disallow setting rtprio in most cases if not superuser */
271 		if (suser(curp) != 0) {
272 			/* can't set someone else's */
273 			if (uap->pid)
274 				return (EPERM);
275 			/* can't set realtime priority */
276 /*
277  * Realtime priority has to be restricted for reasons which should be
278  * obvious. However, for idle priority, there is a potential for
279  * system deadlock if an idleprio process gains a lock on a resource
280  * that other processes need (and the idleprio process can't run
281  * due to a CPU-bound normal process). Fix me! XXX
282  */
283 #if 0
284  			if (RTP_PRIO_IS_REALTIME(rtp.type))
285 #endif
286 			if (rtp.type != RTP_PRIO_NORMAL)
287 				return (EPERM);
288 		}
289 		switch (rtp.type) {
290 #ifdef RTP_PRIO_FIFO
291 		case RTP_PRIO_FIFO:
292 #endif
293 		case RTP_PRIO_REALTIME:
294 		case RTP_PRIO_NORMAL:
295 		case RTP_PRIO_IDLE:
296 			if (rtp.prio > RTP_PRIO_MAX)
297 				return (EINVAL);
298 			p->p_rtprio = rtp;
299 			return (0);
300 		default:
301 			return (EINVAL);
302 		}
303 
304 	default:
305 		return (EINVAL);
306 	}
307 }
308 
309 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
310 #ifndef _SYS_SYSPROTO_H_
311 struct osetrlimit_args {
312 	u_int	which;
313 	struct	orlimit *rlp;
314 };
315 #endif
316 /* ARGSUSED */
317 int
318 osetrlimit(p, uap)
319 	struct proc *p;
320 	register struct osetrlimit_args *uap;
321 {
322 	struct orlimit olim;
323 	struct rlimit lim;
324 	int error;
325 
326 	if ((error =
327 	    copyin((caddr_t)uap->rlp, (caddr_t)&olim, sizeof(struct orlimit))))
328 		return (error);
329 	lim.rlim_cur = olim.rlim_cur;
330 	lim.rlim_max = olim.rlim_max;
331 	return (dosetrlimit(p, uap->which, &lim));
332 }
333 
334 #ifndef _SYS_SYSPROTO_H_
335 struct ogetrlimit_args {
336 	u_int	which;
337 	struct	orlimit *rlp;
338 };
339 #endif
340 /* ARGSUSED */
341 int
342 ogetrlimit(p, uap)
343 	struct proc *p;
344 	register struct ogetrlimit_args *uap;
345 {
346 	struct orlimit olim;
347 
348 	if (uap->which >= RLIM_NLIMITS)
349 		return (EINVAL);
350 	olim.rlim_cur = p->p_rlimit[uap->which].rlim_cur;
351 	if (olim.rlim_cur == -1)
352 		olim.rlim_cur = 0x7fffffff;
353 	olim.rlim_max = p->p_rlimit[uap->which].rlim_max;
354 	if (olim.rlim_max == -1)
355 		olim.rlim_max = 0x7fffffff;
356 	return (copyout((caddr_t)&olim, (caddr_t)uap->rlp, sizeof(olim)));
357 }
358 #endif /* COMPAT_43 || COMPAT_SUNOS */
359 
360 #ifndef _SYS_SYSPROTO_H_
361 struct __setrlimit_args {
362 	u_int	which;
363 	struct	rlimit *rlp;
364 };
365 #endif
366 /* ARGSUSED */
367 int
368 setrlimit(p, uap)
369 	struct proc *p;
370 	register struct __setrlimit_args *uap;
371 {
372 	struct rlimit alim;
373 	int error;
374 
375 	if ((error =
376 	    copyin((caddr_t)uap->rlp, (caddr_t)&alim, sizeof (struct rlimit))))
377 		return (error);
378 	return (dosetrlimit(p, uap->which, &alim));
379 }
380 
381 int
382 dosetrlimit(p, which, limp)
383 	struct proc *p;
384 	u_int which;
385 	struct rlimit *limp;
386 {
387 	register struct rlimit *alimp;
388 	int error;
389 
390 	if (which >= RLIM_NLIMITS)
391 		return (EINVAL);
392 	alimp = &p->p_rlimit[which];
393 
394 	/*
395 	 * Preserve historical bugs by treating negative limits as unsigned.
396 	 */
397 	if (limp->rlim_cur < 0)
398 		limp->rlim_cur = RLIM_INFINITY;
399 	if (limp->rlim_max < 0)
400 		limp->rlim_max = RLIM_INFINITY;
401 
402 	if (limp->rlim_cur > alimp->rlim_max ||
403 	    limp->rlim_max > alimp->rlim_max)
404 		if ((error = suser_xxx(0, p, PRISON_ROOT)))
405 			return (error);
406 	if (limp->rlim_cur > limp->rlim_max)
407 		limp->rlim_cur = limp->rlim_max;
408 	if (p->p_limit->p_refcnt > 1 &&
409 	    (p->p_limit->p_lflags & PL_SHAREMOD) == 0) {
410 		p->p_limit->p_refcnt--;
411 		p->p_limit = limcopy(p->p_limit);
412 		alimp = &p->p_rlimit[which];
413 	}
414 
415 	switch (which) {
416 
417 	case RLIMIT_CPU:
418 		if (limp->rlim_cur > RLIM_INFINITY / (rlim_t)1000000)
419 			p->p_limit->p_cpulimit = RLIM_INFINITY;
420 		else
421 			p->p_limit->p_cpulimit =
422 			    (rlim_t)1000000 * limp->rlim_cur;
423 		break;
424 	case RLIMIT_DATA:
425 		if (limp->rlim_cur > MAXDSIZ)
426 			limp->rlim_cur = MAXDSIZ;
427 		if (limp->rlim_max > MAXDSIZ)
428 			limp->rlim_max = MAXDSIZ;
429 		break;
430 
431 	case RLIMIT_STACK:
432 		if (limp->rlim_cur > MAXSSIZ)
433 			limp->rlim_cur = MAXSSIZ;
434 		if (limp->rlim_max > MAXSSIZ)
435 			limp->rlim_max = MAXSSIZ;
436 		/*
437 		 * Stack is allocated to the max at exec time with only
438 		 * "rlim_cur" bytes accessible.  If stack limit is going
439 		 * up make more accessible, if going down make inaccessible.
440 		 */
441 		if (limp->rlim_cur != alimp->rlim_cur) {
442 			vm_offset_t addr;
443 			vm_size_t size;
444 			vm_prot_t prot;
445 
446 			if (limp->rlim_cur > alimp->rlim_cur) {
447 				prot = VM_PROT_ALL;
448 				size = limp->rlim_cur - alimp->rlim_cur;
449 				addr = USRSTACK - limp->rlim_cur;
450 			} else {
451 				prot = VM_PROT_NONE;
452 				size = alimp->rlim_cur - limp->rlim_cur;
453 				addr = USRSTACK - alimp->rlim_cur;
454 			}
455 			addr = trunc_page(addr);
456 			size = round_page(size);
457 			(void) vm_map_protect(&p->p_vmspace->vm_map,
458 					      addr, addr+size, prot, FALSE);
459 		}
460 		break;
461 
462 	case RLIMIT_NOFILE:
463 		if (limp->rlim_cur > maxfilesperproc)
464 			limp->rlim_cur = maxfilesperproc;
465 		if (limp->rlim_max > maxfilesperproc)
466 			limp->rlim_max = maxfilesperproc;
467 		break;
468 
469 	case RLIMIT_NPROC:
470 		if (limp->rlim_cur > maxprocperuid)
471 			limp->rlim_cur = maxprocperuid;
472 		if (limp->rlim_max > maxprocperuid)
473 			limp->rlim_max = maxprocperuid;
474 		break;
475 	}
476 	*alimp = *limp;
477 	return (0);
478 }
479 
480 #ifndef _SYS_SYSPROTO_H_
481 struct __getrlimit_args {
482 	u_int	which;
483 	struct	rlimit *rlp;
484 };
485 #endif
486 /* ARGSUSED */
487 int
488 getrlimit(p, uap)
489 	struct proc *p;
490 	register struct __getrlimit_args *uap;
491 {
492 
493 	if (uap->which >= RLIM_NLIMITS)
494 		return (EINVAL);
495 	return (copyout((caddr_t)&p->p_rlimit[uap->which], (caddr_t)uap->rlp,
496 	    sizeof (struct rlimit)));
497 }
498 
499 /*
500  * Transform the running time and tick information in proc p into user,
501  * system, and interrupt time usage.
502  */
503 void
504 calcru(p, up, sp, ip)
505 	struct proc *p;
506 	struct timeval *up;
507 	struct timeval *sp;
508 	struct timeval *ip;
509 {
510 	/* {user, system, interrupt, total} {ticks, usec}; previous tu: */
511 	u_int64_t ut, uu, st, su, it, iu, tt, tu, ptu;
512 	int s;
513 	struct timeval tv;
514 
515 	/* XXX: why spl-protect ?  worst case is an off-by-one report */
516 	s = splstatclock();
517 	ut = p->p_uticks;
518 	st = p->p_sticks;
519 	it = p->p_iticks;
520 	splx(s);
521 
522 	tt = ut + st + it;
523 	if (tt == 0) {
524 		st = 1;
525 		tt = 1;
526 	}
527 
528 	tu = p->p_runtime;
529 	if (p == curproc) {
530 		/*
531 		 * Adjust for the current time slice.  This is actually fairly
532 		 * important since the error here is on the order of a time
533 		 * quantum, which is much greater than the sampling error.
534 		 */
535 		microuptime(&tv);
536 		if (timevalcmp(&tv, &switchtime, <))
537 			printf("microuptime() went backwards (%ld.%06ld -> %ld.%06ld)\n",
538 			    switchtime.tv_sec, switchtime.tv_usec,
539 			    tv.tv_sec, tv.tv_usec);
540 		else
541 			tu += (tv.tv_usec - switchtime.tv_usec) +
542 			    (tv.tv_sec - switchtime.tv_sec) * (int64_t)1000000;
543 	}
544 	ptu = p->p_uu + p->p_su + p->p_iu;
545 	if (tu < ptu || (int64_t)tu < 0) {
546 		/* XXX no %qd in kernel.  Truncate. */
547 		printf("calcru: negative time of %ld usec for pid %d (%s)\n",
548 		       (long)tu, p->p_pid, p->p_comm);
549 		tu = ptu;
550 	}
551 
552 	/* Subdivide tu. */
553 	uu = (tu * ut) / tt;
554 	su = (tu * st) / tt;
555 	iu = tu - uu - su;
556 
557 	/* Enforce monotonicity. */
558 	if (uu < p->p_uu || su < p->p_su || iu < p->p_iu) {
559 		if (uu < p->p_uu)
560 			uu = p->p_uu;
561 		else if (uu + p->p_su + p->p_iu > tu)
562 			uu = tu - p->p_su - p->p_iu;
563 		if (st == 0)
564 			su = p->p_su;
565 		else {
566 			su = ((tu - uu) * st) / (st + it);
567 			if (su < p->p_su)
568 				su = p->p_su;
569 			else if (uu + su + p->p_iu > tu)
570 				su = tu - uu - p->p_iu;
571 		}
572 		KASSERT(uu + su + p->p_iu <= tu,
573 		    ("calcru: monotonisation botch 1"));
574 		iu = tu - uu - su;
575 		KASSERT(iu >= p->p_iu,
576 		    ("calcru: monotonisation botch 2"));
577 	}
578 	p->p_uu = uu;
579 	p->p_su = su;
580 	p->p_iu = iu;
581 
582 	up->tv_sec = uu / 1000000;
583 	up->tv_usec = uu % 1000000;
584 	sp->tv_sec = su / 1000000;
585 	sp->tv_usec = su % 1000000;
586 	if (ip != NULL) {
587 		ip->tv_sec = iu / 1000000;
588 		ip->tv_usec = iu % 1000000;
589 	}
590 }
591 
592 #ifndef _SYS_SYSPROTO_H_
593 struct getrusage_args {
594 	int	who;
595 	struct	rusage *rusage;
596 };
597 #endif
598 /* ARGSUSED */
599 int
600 getrusage(p, uap)
601 	register struct proc *p;
602 	register struct getrusage_args *uap;
603 {
604 	register struct rusage *rup;
605 
606 	switch (uap->who) {
607 
608 	case RUSAGE_SELF:
609 		rup = &p->p_stats->p_ru;
610 		calcru(p, &rup->ru_utime, &rup->ru_stime, NULL);
611 		break;
612 
613 	case RUSAGE_CHILDREN:
614 		rup = &p->p_stats->p_cru;
615 		break;
616 
617 	default:
618 		return (EINVAL);
619 	}
620 	return (copyout((caddr_t)rup, (caddr_t)uap->rusage,
621 	    sizeof (struct rusage)));
622 }
623 
624 void
625 ruadd(ru, ru2)
626 	register struct rusage *ru, *ru2;
627 {
628 	register long *ip, *ip2;
629 	register int i;
630 
631 	timevaladd(&ru->ru_utime, &ru2->ru_utime);
632 	timevaladd(&ru->ru_stime, &ru2->ru_stime);
633 	if (ru->ru_maxrss < ru2->ru_maxrss)
634 		ru->ru_maxrss = ru2->ru_maxrss;
635 	ip = &ru->ru_first; ip2 = &ru2->ru_first;
636 	for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
637 		*ip++ += *ip2++;
638 }
639 
640 /*
641  * Make a copy of the plimit structure.
642  * We share these structures copy-on-write after fork,
643  * and copy when a limit is changed.
644  */
645 struct plimit *
646 limcopy(lim)
647 	struct plimit *lim;
648 {
649 	register struct plimit *copy;
650 
651 	MALLOC(copy, struct plimit *, sizeof(struct plimit),
652 	    M_SUBPROC, M_WAITOK);
653 	bcopy(lim->pl_rlimit, copy->pl_rlimit, sizeof(struct plimit));
654 	copy->p_lflags = 0;
655 	copy->p_refcnt = 1;
656 	return (copy);
657 }
658 
659 /*
660  * Find the uidinfo structure for a uid.  This structure is used to
661  * track the total resource consumption (process count, socket buffer
662  * size, etc.) for the uid and impose limits.
663  */
664 void
665 uihashinit()
666 {
667 
668 	uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash);
669 	mtx_init(&uihashtbl_mtx, "uidinfo hash", MTX_DEF);
670 }
671 
672 /*
673  * lookup a uidinfo struct for the parameter uid.
674  * uihashtbl_mtx must be locked.
675  */
676 static struct uidinfo *
677 uilookup(uid)
678 	uid_t uid;
679 {
680 	struct	uihashhead *uipp;
681 	struct	uidinfo *uip;
682 
683 	mtx_assert(&uihashtbl_mtx, MA_OWNED);
684 	uipp = UIHASH(uid);
685 	LIST_FOREACH(uip, uipp, ui_hash)
686 		if (uip->ui_uid == uid)
687 			break;
688 
689 	return (uip);
690 }
691 
692 /*
693  * Create a uidinfo struct for the parameter uid.
694  * uihashtbl_mtx must be locked.
695  */
696 static struct uidinfo *
697 uicreate(uid)
698 	uid_t uid;
699 {
700 	struct	uidinfo *uip;
701 
702 	mtx_assert(&uihashtbl_mtx, MA_OWNED);
703 	MALLOC(uip, struct uidinfo *, sizeof(*uip), M_UIDINFO, M_WAITOK|M_ZERO);
704 	LIST_INSERT_HEAD(UIHASH(uid), uip, ui_hash);
705 	uip->ui_uid = uid;
706 	mtx_init(&uip->ui_mtx, "uidinfo struct", MTX_DEF);
707 	return (uip);
708 }
709 
710 /*
711  * find or allocate a struct uidinfo for a particular uid
712  * increases refcount on uidinfo struct returned.
713  * uifree() should be called on a struct uidinfo when released.
714  */
715 struct uidinfo *
716 uifind(uid)
717 	uid_t uid;
718 {
719 	struct	uidinfo *uip;
720 
721 	mtx_enter(&uihashtbl_mtx, MTX_DEF);
722 	uip = uilookup(uid);
723 	if (uip == NULL)
724 		uip = uicreate(uid);
725 	uihold(uip);
726 	mtx_exit(&uihashtbl_mtx, MTX_DEF);
727 	return (uip);
728 }
729 
730 /*
731  * subtract one from the refcount in the struct uidinfo, if 0 free it
732  */
733 void
734 uifree(uip)
735 	struct	uidinfo *uip;
736 {
737 
738 	mtx_enter(&uihashtbl_mtx, MTX_DEF);
739 	mtx_enter(&uip->ui_mtx, MTX_DEF);
740 	if (--uip->ui_ref == 0) {
741 		if (uip->ui_sbsize != 0)
742 			/* XXX no %qd in kernel.  Truncate. */
743 			printf("freeing uidinfo: uid = %d, sbsize = %ld\n",
744 			    uip->ui_uid, (long)uip->ui_sbsize);
745 		if (uip->ui_proccnt != 0)
746 			printf("freeing uidinfo: uid = %d, proccnt = %ld\n",
747 			    uip->ui_uid, uip->ui_proccnt);
748 		LIST_REMOVE(uip, ui_hash);
749 		mtx_exit(&uihashtbl_mtx, MTX_DEF);
750 		mtx_destroy(&uip->ui_mtx);
751 		FREE(uip, M_UIDINFO);
752 		return;
753 	}
754 	mtx_exit(&uip->ui_mtx, MTX_DEF);
755 	mtx_exit(&uihashtbl_mtx, MTX_DEF);
756 	return;
757 }
758 
759 /*
760  * Change the count associated with number of processes
761  * a given user is using.  When 'max' is 0, don't enforce a limit
762  */
763 int
764 chgproccnt(uip, diff, max)
765 	struct	uidinfo	*uip;
766 	int	diff;
767 	int	max;
768 {
769 
770 	mtx_enter(&uip->ui_mtx, MTX_DEF);
771 	/* don't allow them to exceed max, but allow subtraction */
772 	if (diff > 0 && uip->ui_proccnt + diff > max && max != 0) {
773 		mtx_exit(&uip->ui_mtx, MTX_DEF);
774 		return (0);
775 	}
776 	uip->ui_proccnt += diff;
777 	if (uip->ui_proccnt < 0)
778 		printf("negative proccnt for uid = %d\n", uip->ui_uid);
779 	mtx_exit(&uip->ui_mtx, MTX_DEF);
780 	return (1);
781 }
782 
783 /*
784  * Change the total socket buffer size a user has used.
785  */
786 int
787 chgsbsize(uip, hiwat, to, max)
788 	struct	uidinfo	*uip;
789 	u_long *hiwat;
790 	u_long	to;
791 	rlim_t	max;
792 {
793 	rlim_t new;
794 	int s;
795 
796 	mtx_enter(&uip->ui_mtx, MTX_DEF);
797 	s = splnet();
798 	new = uip->ui_sbsize + to - *hiwat;
799 	/* don't allow them to exceed max, but allow subtraction */
800 	if (to > *hiwat && new > max) {
801 		splx(s);
802 		mtx_exit(&uip->ui_mtx, MTX_DEF);
803 		return (0);
804 	}
805 	uip->ui_sbsize = new;
806 	*hiwat = to;
807 	if (uip->ui_sbsize < 0)
808 		printf("negative sbsize for uid = %d\n", uip->ui_uid);
809 	splx(s);
810 	mtx_exit(&uip->ui_mtx, MTX_DEF);
811 	return (1);
812 }
813