xref: /dragonfly/sys/kern/kern_resource.c (revision 984263bc)
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: src/sys/kern/kern_resource.c,v 1.55.2.5 2001/11/03 01:41:08 ps Exp $
40  */
41 
42 #include "opt_compat.h"
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/sysproto.h>
47 #include <sys/file.h>
48 #include <sys/kernel.h>
49 #include <sys/resourcevar.h>
50 #include <sys/malloc.h>
51 #include <sys/proc.h>
52 #include <sys/time.h>
53 
54 #include <vm/vm.h>
55 #include <vm/vm_param.h>
56 #include <sys/lock.h>
57 #include <vm/pmap.h>
58 #include <vm/vm_map.h>
59 
60 static int donice __P((struct proc *curp, struct proc *chgp, int n));
61 /* dosetrlimit non-static:  Needed by SysVR4 emulator */
62 int dosetrlimit __P((struct proc *p, u_int which, struct rlimit *limp));
63 
64 static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures");
65 #define	UIHASH(uid)	(&uihashtbl[(uid) & uihash])
66 static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
67 static u_long uihash;		/* size of hash table - 1 */
68 
69 static struct uidinfo	*uicreate __P((uid_t uid));
70 static struct uidinfo	*uilookup __P((uid_t uid));
71 
72 /*
73  * Resource controls and accounting.
74  */
75 
76 #ifndef _SYS_SYSPROTO_H_
77 struct getpriority_args {
78 	int	which;
79 	int	who;
80 };
81 #endif
82 int
83 getpriority(curp, uap)
84 	struct proc *curp;
85 	register struct getpriority_args *uap;
86 {
87 	register struct proc *p;
88 	register int low = PRIO_MAX + 1;
89 
90 	switch (uap->which) {
91 
92 	case PRIO_PROCESS:
93 		if (uap->who == 0)
94 			p = curp;
95 		else
96 			p = pfind(uap->who);
97 		if (p == 0)
98 			break;
99 		if (!PRISON_CHECK(curp, p))
100 			break;
101 		low = p->p_nice;
102 		break;
103 
104 	case PRIO_PGRP: {
105 		register struct pgrp *pg;
106 
107 		if (uap->who == 0)
108 			pg = curp->p_pgrp;
109 		else if ((pg = pgfind(uap->who)) == NULL)
110 			break;
111 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
112 			if ((PRISON_CHECK(curp, p) && p->p_nice < low))
113 				low = p->p_nice;
114 		}
115 		break;
116 	}
117 
118 	case PRIO_USER:
119 		if (uap->who == 0)
120 			uap->who = curp->p_ucred->cr_uid;
121 		LIST_FOREACH(p, &allproc, p_list)
122 			if (PRISON_CHECK(curp, p) &&
123 			    p->p_ucred->cr_uid == uap->who &&
124 			    p->p_nice < low)
125 				low = p->p_nice;
126 		break;
127 
128 	default:
129 		return (EINVAL);
130 	}
131 	if (low == PRIO_MAX + 1)
132 		return (ESRCH);
133 	curp->p_retval[0] = low;
134 	return (0);
135 }
136 
137 #ifndef _SYS_SYSPROTO_H_
138 struct setpriority_args {
139 	int	which;
140 	int	who;
141 	int	prio;
142 };
143 #endif
144 /* ARGSUSED */
145 int
146 setpriority(curp, uap)
147 	struct proc *curp;
148 	register struct setpriority_args *uap;
149 {
150 	register struct proc *p;
151 	int found = 0, error = 0;
152 
153 	switch (uap->which) {
154 
155 	case PRIO_PROCESS:
156 		if (uap->who == 0)
157 			p = curp;
158 		else
159 			p = pfind(uap->who);
160 		if (p == 0)
161 			break;
162 		if (!PRISON_CHECK(curp, p))
163 			break;
164 		error = donice(curp, p, uap->prio);
165 		found++;
166 		break;
167 
168 	case PRIO_PGRP: {
169 		register struct pgrp *pg;
170 
171 		if (uap->who == 0)
172 			pg = curp->p_pgrp;
173 		else if ((pg = pgfind(uap->who)) == NULL)
174 			break;
175 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
176 			if (PRISON_CHECK(curp, p)) {
177 				error = donice(curp, p, uap->prio);
178 				found++;
179 			}
180 		}
181 		break;
182 	}
183 
184 	case PRIO_USER:
185 		if (uap->who == 0)
186 			uap->who = curp->p_ucred->cr_uid;
187 		LIST_FOREACH(p, &allproc, p_list)
188 			if (p->p_ucred->cr_uid == uap->who &&
189 			    PRISON_CHECK(curp, p)) {
190 				error = donice(curp, p, uap->prio);
191 				found++;
192 			}
193 		break;
194 
195 	default:
196 		return (EINVAL);
197 	}
198 	if (found == 0)
199 		return (ESRCH);
200 	return (error);
201 }
202 
203 static int
204 donice(curp, chgp, n)
205 	register struct proc *curp, *chgp;
206 	register int n;
207 {
208 	register struct pcred *pcred = curp->p_cred;
209 
210 	if (pcred->pc_ucred->cr_uid && pcred->p_ruid &&
211 	    pcred->pc_ucred->cr_uid != chgp->p_ucred->cr_uid &&
212 	    pcred->p_ruid != chgp->p_ucred->cr_uid)
213 		return (EPERM);
214 	if (n > PRIO_MAX)
215 		n = PRIO_MAX;
216 	if (n < PRIO_MIN)
217 		n = PRIO_MIN;
218 	if (n < chgp->p_nice && suser(curp))
219 		return (EACCES);
220 	chgp->p_nice = n;
221 	(void)resetpriority(chgp);
222 	return (0);
223 }
224 
225 /* rtprio system call */
226 #ifndef _SYS_SYSPROTO_H_
227 struct rtprio_args {
228 	int		function;
229 	pid_t		pid;
230 	struct rtprio	*rtp;
231 };
232 #endif
233 
234 /*
235  * Set realtime priority
236  */
237 
238 /* ARGSUSED */
239 int
240 rtprio(curp, uap)
241 	struct proc *curp;
242 	register struct rtprio_args *uap;
243 {
244 	register struct proc *p;
245 	register struct pcred *pcred = curp->p_cred;
246 	struct rtprio rtp;
247 	int error;
248 
249 	error = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
250 	if (error)
251 		return (error);
252 
253 	if (uap->pid == 0)
254 		p = curp;
255 	else
256 		p = pfind(uap->pid);
257 
258 	if (p == 0)
259 		return (ESRCH);
260 
261 	switch (uap->function) {
262 	case RTP_LOOKUP:
263 		return (copyout(&p->p_rtprio, uap->rtp, sizeof(struct rtprio)));
264 	case RTP_SET:
265 		if (pcred->pc_ucred->cr_uid && pcred->p_ruid &&
266 		    pcred->pc_ucred->cr_uid != p->p_ucred->cr_uid &&
267 		    pcred->p_ruid != p->p_ucred->cr_uid)
268 		        return (EPERM);
269 		/* disallow setting rtprio in most cases if not superuser */
270 		if (suser(curp)) {
271 			/* can't set someone else's */
272 			if (uap->pid)
273 				return (EPERM);
274 			/* can't set realtime priority */
275 /*
276  * Realtime priority has to be restricted for reasons which should be
277  * obvious. However, for idle priority, there is a potential for
278  * system deadlock if an idleprio process gains a lock on a resource
279  * that other processes need (and the idleprio process can't run
280  * due to a CPU-bound normal process). Fix me! XXX
281  */
282 #if 0
283  			if (RTP_PRIO_IS_REALTIME(rtp.type))
284 #endif
285 			if (rtp.type != RTP_PRIO_NORMAL)
286 				return (EPERM);
287 		}
288 		switch (rtp.type) {
289 #ifdef RTP_PRIO_FIFO
290 		case RTP_PRIO_FIFO:
291 #endif
292 		case RTP_PRIO_REALTIME:
293 		case RTP_PRIO_NORMAL:
294 		case RTP_PRIO_IDLE:
295 			if (rtp.prio > RTP_PRIO_MAX)
296 				return (EINVAL);
297 			p->p_rtprio = rtp;
298 			return (0);
299 		default:
300 			return (EINVAL);
301 		}
302 
303 	default:
304 		return (EINVAL);
305 	}
306 }
307 
308 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
309 #ifndef _SYS_SYSPROTO_H_
310 struct osetrlimit_args {
311 	u_int	which;
312 	struct	orlimit *rlp;
313 };
314 #endif
315 /* ARGSUSED */
316 int
317 osetrlimit(p, uap)
318 	struct proc *p;
319 	register struct osetrlimit_args *uap;
320 {
321 	struct orlimit olim;
322 	struct rlimit lim;
323 	int error;
324 
325 	if ((error =
326 	    copyin((caddr_t)uap->rlp, (caddr_t)&olim, sizeof(struct orlimit))))
327 		return (error);
328 	lim.rlim_cur = olim.rlim_cur;
329 	lim.rlim_max = olim.rlim_max;
330 	return (dosetrlimit(p, uap->which, &lim));
331 }
332 
333 #ifndef _SYS_SYSPROTO_H_
334 struct ogetrlimit_args {
335 	u_int	which;
336 	struct	orlimit *rlp;
337 };
338 #endif
339 /* ARGSUSED */
340 int
341 ogetrlimit(p, uap)
342 	struct proc *p;
343 	register struct ogetrlimit_args *uap;
344 {
345 	struct orlimit olim;
346 
347 	if (uap->which >= RLIM_NLIMITS)
348 		return (EINVAL);
349 	olim.rlim_cur = p->p_rlimit[uap->which].rlim_cur;
350 	if (olim.rlim_cur == -1)
351 		olim.rlim_cur = 0x7fffffff;
352 	olim.rlim_max = p->p_rlimit[uap->which].rlim_max;
353 	if (olim.rlim_max == -1)
354 		olim.rlim_max = 0x7fffffff;
355 	return (copyout((caddr_t)&olim, (caddr_t)uap->rlp, sizeof(olim)));
356 }
357 #endif /* COMPAT_43 || COMPAT_SUNOS */
358 
359 #ifndef _SYS_SYSPROTO_H_
360 struct __setrlimit_args {
361 	u_int	which;
362 	struct	rlimit *rlp;
363 };
364 #endif
365 /* ARGSUSED */
366 int
367 setrlimit(p, uap)
368 	struct proc *p;
369 	register struct __setrlimit_args *uap;
370 {
371 	struct rlimit alim;
372 	int error;
373 
374 	if ((error =
375 	    copyin((caddr_t)uap->rlp, (caddr_t)&alim, sizeof (struct rlimit))))
376 		return (error);
377 	return (dosetrlimit(p, uap->which, &alim));
378 }
379 
380 int
381 dosetrlimit(p, which, limp)
382 	struct proc *p;
383 	u_int which;
384 	struct rlimit *limp;
385 {
386 	register struct rlimit *alimp;
387 	int error;
388 
389 	if (which >= RLIM_NLIMITS)
390 		return (EINVAL);
391 	alimp = &p->p_rlimit[which];
392 
393 	/*
394 	 * Preserve historical bugs by treating negative limits as unsigned.
395 	 */
396 	if (limp->rlim_cur < 0)
397 		limp->rlim_cur = RLIM_INFINITY;
398 	if (limp->rlim_max < 0)
399 		limp->rlim_max = RLIM_INFINITY;
400 
401 	if (limp->rlim_cur > alimp->rlim_max ||
402 	    limp->rlim_max > alimp->rlim_max)
403 		if ((error = suser_xxx(0, p, PRISON_ROOT)))
404 			return (error);
405 	if (limp->rlim_cur > limp->rlim_max)
406 		limp->rlim_cur = limp->rlim_max;
407 	if (p->p_limit->p_refcnt > 1 &&
408 	    (p->p_limit->p_lflags & PL_SHAREMOD) == 0) {
409 		p->p_limit->p_refcnt--;
410 		p->p_limit = limcopy(p->p_limit);
411 		alimp = &p->p_rlimit[which];
412 	}
413 
414 	switch (which) {
415 
416 	case RLIMIT_CPU:
417 		if (limp->rlim_cur > RLIM_INFINITY / (rlim_t)1000000)
418 			p->p_limit->p_cpulimit = RLIM_INFINITY;
419 		else
420 			p->p_limit->p_cpulimit =
421 			    (rlim_t)1000000 * limp->rlim_cur;
422 		break;
423 	case RLIMIT_DATA:
424 		if (limp->rlim_cur > maxdsiz)
425 			limp->rlim_cur = maxdsiz;
426 		if (limp->rlim_max > maxdsiz)
427 			limp->rlim_max = maxdsiz;
428 		break;
429 
430 	case RLIMIT_STACK:
431 		if (limp->rlim_cur > maxssiz)
432 			limp->rlim_cur = maxssiz;
433 		if (limp->rlim_max > maxssiz)
434 			limp->rlim_max = maxssiz;
435 		/*
436 		 * Stack is allocated to the max at exec time with only
437 		 * "rlim_cur" bytes accessible.  If stack limit is going
438 		 * up make more accessible, if going down make inaccessible.
439 		 */
440 		if (limp->rlim_cur != alimp->rlim_cur) {
441 			vm_offset_t addr;
442 			vm_size_t size;
443 			vm_prot_t prot;
444 
445 			if (limp->rlim_cur > alimp->rlim_cur) {
446 				prot = VM_PROT_ALL;
447 				size = limp->rlim_cur - alimp->rlim_cur;
448 				addr = USRSTACK - limp->rlim_cur;
449 			} else {
450 				prot = VM_PROT_NONE;
451 				size = alimp->rlim_cur - limp->rlim_cur;
452 				addr = USRSTACK - alimp->rlim_cur;
453 			}
454 			addr = trunc_page(addr);
455 			size = round_page(size);
456 			(void) vm_map_protect(&p->p_vmspace->vm_map,
457 					      addr, addr+size, prot, FALSE);
458 		}
459 		break;
460 
461 	case RLIMIT_NOFILE:
462 		if (limp->rlim_cur > maxfilesperproc)
463 			limp->rlim_cur = maxfilesperproc;
464 		if (limp->rlim_max > maxfilesperproc)
465 			limp->rlim_max = maxfilesperproc;
466 		break;
467 
468 	case RLIMIT_NPROC:
469 		if (limp->rlim_cur > maxprocperuid)
470 			limp->rlim_cur = maxprocperuid;
471 		if (limp->rlim_max > maxprocperuid)
472 			limp->rlim_max = maxprocperuid;
473 		if (limp->rlim_cur < 1)
474 			limp->rlim_cur = 1;
475 		if (limp->rlim_max < 1)
476 			limp->rlim_max = 1;
477 		break;
478 	}
479 	*alimp = *limp;
480 	return (0);
481 }
482 
483 #ifndef _SYS_SYSPROTO_H_
484 struct __getrlimit_args {
485 	u_int	which;
486 	struct	rlimit *rlp;
487 };
488 #endif
489 /* ARGSUSED */
490 int
491 getrlimit(p, uap)
492 	struct proc *p;
493 	register struct __getrlimit_args *uap;
494 {
495 
496 	if (uap->which >= RLIM_NLIMITS)
497 		return (EINVAL);
498 	return (copyout((caddr_t)&p->p_rlimit[uap->which], (caddr_t)uap->rlp,
499 	    sizeof (struct rlimit)));
500 }
501 
502 /*
503  * Transform the running time and tick information in proc p into user,
504  * system, and interrupt time usage.
505  */
506 void
507 calcru(p, up, sp, ip)
508 	struct proc *p;
509 	struct timeval *up;
510 	struct timeval *sp;
511 	struct timeval *ip;
512 {
513 	/* {user, system, interrupt, total} {ticks, usec}; previous tu: */
514 	u_int64_t ut, uu, st, su, it, iu, tt, tu, ptu;
515 	int s;
516 	struct timeval tv;
517 
518 	/* XXX: why spl-protect ?  worst case is an off-by-one report */
519 	s = splstatclock();
520 	ut = p->p_uticks;
521 	st = p->p_sticks;
522 	it = p->p_iticks;
523 	splx(s);
524 
525 	tt = ut + st + it;
526 	if (tt == 0) {
527 		st = 1;
528 		tt = 1;
529 	}
530 
531 	tu = p->p_runtime;
532 	if (p == curproc) {
533 		/*
534 		 * Adjust for the current time slice.  This is actually fairly
535 		 * important since the error here is on the order of a time
536 		 * quantum, which is much greater than the sampling error.
537 		 */
538 		microuptime(&tv);
539 		if (timevalcmp(&tv, &switchtime, <))
540 			printf("microuptime() went backwards (%ld.%06ld -> %ld.%06ld)\n",
541 			    switchtime.tv_sec, switchtime.tv_usec,
542 			    tv.tv_sec, tv.tv_usec);
543 		else
544 			tu += (tv.tv_usec - switchtime.tv_usec) +
545 			    (tv.tv_sec - switchtime.tv_sec) * (int64_t)1000000;
546 	}
547 	ptu = p->p_uu + p->p_su + p->p_iu;
548 	if (tu < ptu || (int64_t)tu < 0) {
549 		/* XXX no %qd in kernel.  Truncate. */
550 		printf("calcru: negative time of %ld usec for pid %d (%s)\n",
551 		       (long)tu, p->p_pid, p->p_comm);
552 		tu = ptu;
553 	}
554 
555 	/* Subdivide tu. */
556 	uu = (tu * ut) / tt;
557 	su = (tu * st) / tt;
558 	iu = tu - uu - su;
559 
560 	/* Enforce monotonicity. */
561 	if (uu < p->p_uu || su < p->p_su || iu < p->p_iu) {
562 		if (uu < p->p_uu)
563 			uu = p->p_uu;
564 		else if (uu + p->p_su + p->p_iu > tu)
565 			uu = tu - p->p_su - p->p_iu;
566 		if (st == 0)
567 			su = p->p_su;
568 		else {
569 			su = ((tu - uu) * st) / (st + it);
570 			if (su < p->p_su)
571 				su = p->p_su;
572 			else if (uu + su + p->p_iu > tu)
573 				su = tu - uu - p->p_iu;
574 		}
575 		KASSERT(uu + su + p->p_iu <= tu,
576 		    ("calcru: monotonisation botch 1"));
577 		iu = tu - uu - su;
578 		KASSERT(iu >= p->p_iu,
579 		    ("calcru: monotonisation botch 2"));
580 	}
581 	p->p_uu = uu;
582 	p->p_su = su;
583 	p->p_iu = iu;
584 
585 	up->tv_sec = uu / 1000000;
586 	up->tv_usec = uu % 1000000;
587 	sp->tv_sec = su / 1000000;
588 	sp->tv_usec = su % 1000000;
589 	if (ip != NULL) {
590 		ip->tv_sec = iu / 1000000;
591 		ip->tv_usec = iu % 1000000;
592 	}
593 }
594 
595 #ifndef _SYS_SYSPROTO_H_
596 struct getrusage_args {
597 	int	who;
598 	struct	rusage *rusage;
599 };
600 #endif
601 /* ARGSUSED */
602 int
603 getrusage(p, uap)
604 	register struct proc *p;
605 	register struct getrusage_args *uap;
606 {
607 	register struct rusage *rup;
608 
609 	switch (uap->who) {
610 
611 	case RUSAGE_SELF:
612 		rup = &p->p_stats->p_ru;
613 		calcru(p, &rup->ru_utime, &rup->ru_stime, NULL);
614 		break;
615 
616 	case RUSAGE_CHILDREN:
617 		rup = &p->p_stats->p_cru;
618 		break;
619 
620 	default:
621 		return (EINVAL);
622 	}
623 	return (copyout((caddr_t)rup, (caddr_t)uap->rusage,
624 	    sizeof (struct rusage)));
625 }
626 
627 void
628 ruadd(ru, ru2)
629 	register struct rusage *ru, *ru2;
630 {
631 	register long *ip, *ip2;
632 	register int i;
633 
634 	timevaladd(&ru->ru_utime, &ru2->ru_utime);
635 	timevaladd(&ru->ru_stime, &ru2->ru_stime);
636 	if (ru->ru_maxrss < ru2->ru_maxrss)
637 		ru->ru_maxrss = ru2->ru_maxrss;
638 	ip = &ru->ru_first; ip2 = &ru2->ru_first;
639 	for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
640 		*ip++ += *ip2++;
641 }
642 
643 /*
644  * Make a copy of the plimit structure.
645  * We share these structures copy-on-write after fork,
646  * and copy when a limit is changed.
647  */
648 struct plimit *
649 limcopy(lim)
650 	struct plimit *lim;
651 {
652 	register struct plimit *copy;
653 
654 	MALLOC(copy, struct plimit *, sizeof(struct plimit),
655 	    M_SUBPROC, M_WAITOK);
656 	bcopy(lim->pl_rlimit, copy->pl_rlimit, sizeof(struct plimit));
657 	copy->p_lflags = 0;
658 	copy->p_refcnt = 1;
659 	return (copy);
660 }
661 
662 /*
663  * Find the uidinfo structure for a uid.  This structure is used to
664  * track the total resource consumption (process count, socket buffer
665  * size, etc.) for the uid and impose limits.
666  */
667 void
668 uihashinit()
669 {
670 	uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash);
671 }
672 
673 static struct uidinfo *
674 uilookup(uid)
675 	uid_t uid;
676 {
677 	struct	uihashhead *uipp;
678 	struct	uidinfo *uip;
679 
680 	uipp = UIHASH(uid);
681 	LIST_FOREACH(uip, uipp, ui_hash)
682 		if (uip->ui_uid == uid)
683 			break;
684 
685 	return (uip);
686 }
687 
688 static struct uidinfo *
689 uicreate(uid)
690 	uid_t uid;
691 {
692 	struct	uidinfo *uip, *norace;
693 
694 	MALLOC(uip, struct uidinfo *, sizeof(*uip), M_UIDINFO, M_NOWAIT);
695 	if (uip == NULL) {
696 		MALLOC(uip, struct uidinfo *, sizeof(*uip), M_UIDINFO, M_WAITOK);
697 		/*
698 		 * if we M_WAITOK we must look afterwards or risk
699 		 * redundant entries
700 		 */
701 		norace = uilookup(uid);
702 		if (norace != NULL) {
703 			FREE(uip, M_UIDINFO);
704 			return (norace);
705 		}
706 	}
707 	LIST_INSERT_HEAD(UIHASH(uid), uip, ui_hash);
708 	uip->ui_uid = uid;
709 	uip->ui_proccnt = 0;
710 	uip->ui_sbsize = 0;
711 	uip->ui_ref = 0;
712 	return (uip);
713 }
714 
715 struct uidinfo *
716 uifind(uid)
717 	uid_t uid;
718 {
719 	struct	uidinfo *uip;
720 
721 	uip = uilookup(uid);
722 	if (uip == NULL)
723 		uip = uicreate(uid);
724 	uip->ui_ref++;
725 	return (uip);
726 }
727 
728 int
729 uifree(uip)
730 	struct	uidinfo *uip;
731 {
732 
733 	if (--uip->ui_ref == 0) {
734 		if (uip->ui_sbsize != 0)
735 			/* XXX no %qd in kernel.  Truncate. */
736 			printf("freeing uidinfo: uid = %d, sbsize = %ld\n",
737 			    uip->ui_uid, (long)uip->ui_sbsize);
738 		if (uip->ui_proccnt != 0)
739 			printf("freeing uidinfo: uid = %d, proccnt = %ld\n",
740 			    uip->ui_uid, uip->ui_proccnt);
741 		LIST_REMOVE(uip, ui_hash);
742 		FREE(uip, M_UIDINFO);
743 		return (1);
744 	}
745 	return (0);
746 }
747 
748 /*
749  * Change the count associated with number of processes
750  * a given user is using.  When 'max' is 0, don't enforce a limit
751  */
752 int
753 chgproccnt(uip, diff, max)
754 	struct	uidinfo	*uip;
755 	int	diff;
756 	int	max;
757 {
758 	/* don't allow them to exceed max, but allow subtraction */
759 	if (diff > 0 && uip->ui_proccnt + diff > max && max != 0)
760 		return (0);
761 	uip->ui_proccnt += diff;
762 	if (uip->ui_proccnt < 0)
763 		printf("negative proccnt for uid = %d\n", uip->ui_uid);
764 	return (1);
765 }
766 
767 /*
768  * Change the total socket buffer size a user has used.
769  */
770 int
771 chgsbsize(uip, hiwat, to, max)
772 	struct	uidinfo	*uip;
773 	u_long *hiwat;
774 	u_long	to;
775 	rlim_t	max;
776 {
777 	rlim_t new;
778 	int s;
779 
780 	s = splnet();
781 	new = uip->ui_sbsize + to - *hiwat;
782 	/* don't allow them to exceed max, but allow subtraction */
783 	if (to > *hiwat && new > max) {
784 		splx(s);
785 		return (0);
786 	}
787 	uip->ui_sbsize = new;
788 	*hiwat = to;
789 	if (uip->ui_sbsize < 0)
790 		printf("negative sbsize for uid = %d\n", uip->ui_uid);
791 	splx(s);
792 	return (1);
793 }
794