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 * $DragonFly: src/sys/kern/kern_resource.c,v 1.17 2003/11/05 23:26:20 dillon Exp $ 41 */ 42 43 #include "opt_compat.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/kern_syscall.h> 50 #include <sys/kernel.h> 51 #include <sys/resourcevar.h> 52 #include <sys/malloc.h> 53 #include <sys/proc.h> 54 #include <sys/time.h> 55 56 #include <vm/vm.h> 57 #include <vm/vm_param.h> 58 #include <sys/lock.h> 59 #include <vm/pmap.h> 60 #include <vm/vm_map.h> 61 62 static int donice (struct proc *chgp, int n); 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 (uid_t uid); 70 static struct uidinfo *uilookup (uid_t uid); 71 72 /* 73 * Resource controls and accounting. 74 */ 75 76 int 77 getpriority(struct getpriority_args *uap) 78 { 79 struct proc *curp = curproc; 80 struct proc *p; 81 int low = PRIO_MAX + 1; 82 83 switch (uap->which) { 84 case PRIO_PROCESS: 85 if (uap->who == 0) 86 p = curp; 87 else 88 p = pfind(uap->who); 89 if (p == 0) 90 break; 91 if (!PRISON_CHECK(curp->p_ucred, p->p_ucred)) 92 break; 93 low = p->p_nice; 94 break; 95 96 case PRIO_PGRP: 97 { 98 struct pgrp *pg; 99 100 if (uap->who == 0) 101 pg = curp->p_pgrp; 102 else if ((pg = pgfind(uap->who)) == NULL) 103 break; 104 LIST_FOREACH(p, &pg->pg_members, p_pglist) { 105 if ((PRISON_CHECK(curp->p_ucred, p->p_ucred) && p->p_nice < low)) 106 low = p->p_nice; 107 } 108 break; 109 } 110 case PRIO_USER: 111 if (uap->who == 0) 112 uap->who = curp->p_ucred->cr_uid; 113 FOREACH_PROC_IN_SYSTEM(p) 114 if (PRISON_CHECK(curp->p_ucred, p->p_ucred) && 115 p->p_ucred->cr_uid == uap->who && 116 p->p_nice < low) 117 low = p->p_nice; 118 break; 119 120 default: 121 return (EINVAL); 122 } 123 if (low == PRIO_MAX + 1) 124 return (ESRCH); 125 uap->sysmsg_result = low; 126 return (0); 127 } 128 129 /* ARGSUSED */ 130 int 131 setpriority(struct setpriority_args *uap) 132 { 133 struct proc *curp = curproc; 134 struct proc *p; 135 int found = 0, error = 0; 136 137 switch (uap->which) { 138 139 case PRIO_PROCESS: 140 if (uap->who == 0) 141 p = curp; 142 else 143 p = pfind(uap->who); 144 if (p == 0) 145 break; 146 if (!PRISON_CHECK(curp->p_ucred, p->p_ucred)) 147 break; 148 error = donice(p, uap->prio); 149 found++; 150 break; 151 152 case PRIO_PGRP: 153 { 154 struct pgrp *pg; 155 156 if (uap->who == 0) 157 pg = curp->p_pgrp; 158 else if ((pg = pgfind(uap->who)) == NULL) 159 break; 160 LIST_FOREACH(p, &pg->pg_members, p_pglist) { 161 if (PRISON_CHECK(curp->p_ucred, p->p_ucred)) { 162 error = donice(p, uap->prio); 163 found++; 164 } 165 } 166 break; 167 } 168 case PRIO_USER: 169 if (uap->who == 0) 170 uap->who = curp->p_ucred->cr_uid; 171 FOREACH_PROC_IN_SYSTEM(p) 172 if (p->p_ucred->cr_uid == uap->who && 173 PRISON_CHECK(curp->p_ucred, p->p_ucred)) { 174 error = donice(p, uap->prio); 175 found++; 176 } 177 break; 178 179 default: 180 return (EINVAL); 181 } 182 if (found == 0) 183 return (ESRCH); 184 return (error); 185 } 186 187 static int 188 donice(struct proc *chgp, int n) 189 { 190 struct proc *curp = curproc; 191 struct ucred *cr = curp->p_ucred; 192 193 if (cr->cr_uid && cr->cr_ruid && 194 cr->cr_uid != chgp->p_ucred->cr_uid && 195 cr->cr_ruid != chgp->p_ucred->cr_uid) 196 return (EPERM); 197 if (n > PRIO_MAX) 198 n = PRIO_MAX; 199 if (n < PRIO_MIN) 200 n = PRIO_MIN; 201 if (n < chgp->p_nice && suser_cred(cr, 0)) 202 return (EACCES); 203 chgp->p_nice = n; 204 (void)resetpriority(chgp); 205 return (0); 206 } 207 208 /* 209 * Set realtime priority 210 */ 211 /* ARGSUSED */ 212 int 213 rtprio(struct rtprio_args *uap) 214 { 215 struct proc *curp = curproc; 216 struct proc *p; 217 struct ucred *cr = curp->p_ucred; 218 struct rtprio rtp; 219 int error; 220 221 error = copyin(uap->rtp, &rtp, sizeof(struct rtprio)); 222 if (error) 223 return (error); 224 225 if (uap->pid == 0) 226 p = curp; 227 else 228 p = pfind(uap->pid); 229 230 if (p == 0) 231 return (ESRCH); 232 233 switch (uap->function) { 234 case RTP_LOOKUP: 235 return (copyout(&p->p_rtprio, uap->rtp, sizeof(struct rtprio))); 236 case RTP_SET: 237 if (cr->cr_uid && cr->cr_ruid && 238 cr->cr_uid != p->p_ucred->cr_uid && 239 cr->cr_ruid != p->p_ucred->cr_uid) 240 return (EPERM); 241 /* disallow setting rtprio in most cases if not superuser */ 242 if (suser_cred(cr, 0)) { 243 /* can't set someone else's */ 244 if (uap->pid) 245 return (EPERM); 246 /* can't set realtime priority */ 247 /* 248 * Realtime priority has to be restricted for reasons which should be 249 * obvious. However, for idle priority, there is a potential for 250 * system deadlock if an idleprio process gains a lock on a resource 251 * that other processes need (and the idleprio process can't run 252 * due to a CPU-bound normal process). Fix me! XXX 253 */ 254 if (RTP_PRIO_IS_REALTIME(rtp.type)) 255 return (EPERM); 256 } 257 switch (rtp.type) { 258 #ifdef RTP_PRIO_FIFO 259 case RTP_PRIO_FIFO: 260 #endif 261 case RTP_PRIO_REALTIME: 262 case RTP_PRIO_NORMAL: 263 case RTP_PRIO_IDLE: 264 if (rtp.prio > RTP_PRIO_MAX) 265 return (EINVAL); 266 p->p_rtprio = rtp; 267 return (0); 268 default: 269 return (EINVAL); 270 } 271 272 default: 273 return (EINVAL); 274 } 275 } 276 277 int 278 setrlimit(struct __setrlimit_args *uap) 279 { 280 struct rlimit alim; 281 int error; 282 283 error = copyin(uap->rlp, &alim, sizeof(alim)); 284 if (error) 285 return (error); 286 287 error = kern_setrlimit(uap->which, &alim); 288 289 return (error); 290 } 291 292 int 293 kern_setrlimit(u_int which, struct rlimit *limp) 294 { 295 struct proc *p = curproc; 296 struct rlimit *alimp; 297 int error; 298 299 if (which >= RLIM_NLIMITS) 300 return (EINVAL); 301 alimp = &p->p_rlimit[which]; 302 303 /* 304 * Preserve historical bugs by treating negative limits as unsigned. 305 */ 306 if (limp->rlim_cur < 0) 307 limp->rlim_cur = RLIM_INFINITY; 308 if (limp->rlim_max < 0) 309 limp->rlim_max = RLIM_INFINITY; 310 311 if (limp->rlim_cur > alimp->rlim_max || 312 limp->rlim_max > alimp->rlim_max) 313 if ((error = suser_cred(p->p_ucred, PRISON_ROOT))) 314 return (error); 315 if (limp->rlim_cur > limp->rlim_max) 316 limp->rlim_cur = limp->rlim_max; 317 if (p->p_limit->p_refcnt > 1 && 318 (p->p_limit->p_lflags & PL_SHAREMOD) == 0) { 319 p->p_limit->p_refcnt--; 320 p->p_limit = limcopy(p->p_limit); 321 alimp = &p->p_rlimit[which]; 322 } 323 324 switch (which) { 325 326 case RLIMIT_CPU: 327 if (limp->rlim_cur > RLIM_INFINITY / (rlim_t)1000000) 328 p->p_limit->p_cpulimit = RLIM_INFINITY; 329 else 330 p->p_limit->p_cpulimit = 331 (rlim_t)1000000 * limp->rlim_cur; 332 break; 333 case RLIMIT_DATA: 334 if (limp->rlim_cur > maxdsiz) 335 limp->rlim_cur = maxdsiz; 336 if (limp->rlim_max > maxdsiz) 337 limp->rlim_max = maxdsiz; 338 break; 339 340 case RLIMIT_STACK: 341 if (limp->rlim_cur > maxssiz) 342 limp->rlim_cur = maxssiz; 343 if (limp->rlim_max > maxssiz) 344 limp->rlim_max = maxssiz; 345 /* 346 * Stack is allocated to the max at exec time with only 347 * "rlim_cur" bytes accessible. If stack limit is going 348 * up make more accessible, if going down make inaccessible. 349 */ 350 if (limp->rlim_cur != alimp->rlim_cur) { 351 vm_offset_t addr; 352 vm_size_t size; 353 vm_prot_t prot; 354 355 if (limp->rlim_cur > alimp->rlim_cur) { 356 prot = VM_PROT_ALL; 357 size = limp->rlim_cur - alimp->rlim_cur; 358 addr = USRSTACK - limp->rlim_cur; 359 } else { 360 prot = VM_PROT_NONE; 361 size = alimp->rlim_cur - limp->rlim_cur; 362 addr = USRSTACK - alimp->rlim_cur; 363 } 364 addr = trunc_page(addr); 365 size = round_page(size); 366 (void) vm_map_protect(&p->p_vmspace->vm_map, 367 addr, addr+size, prot, FALSE); 368 } 369 break; 370 371 case RLIMIT_NOFILE: 372 if (limp->rlim_cur > maxfilesperproc) 373 limp->rlim_cur = maxfilesperproc; 374 if (limp->rlim_max > maxfilesperproc) 375 limp->rlim_max = maxfilesperproc; 376 break; 377 378 case RLIMIT_NPROC: 379 if (limp->rlim_cur > maxprocperuid) 380 limp->rlim_cur = maxprocperuid; 381 if (limp->rlim_max > maxprocperuid) 382 limp->rlim_max = maxprocperuid; 383 if (limp->rlim_cur < 1) 384 limp->rlim_cur = 1; 385 if (limp->rlim_max < 1) 386 limp->rlim_max = 1; 387 break; 388 } 389 *alimp = *limp; 390 return (0); 391 } 392 393 /* 394 * The rlimit indexed by which is returned in the second argument. 395 */ 396 int 397 kern_getrlimit(u_int which, struct rlimit *limp) 398 { 399 struct thread *td = curthread; 400 struct proc *p = td->td_proc; 401 402 if (which >= RLIM_NLIMITS) 403 return (EINVAL); 404 405 *limp = p->p_rlimit[which]; 406 407 return (0); 408 } 409 410 int 411 getrlimit(struct __getrlimit_args *uap) 412 { 413 struct rlimit lim; 414 int error; 415 416 error = kern_getrlimit(uap->which, &lim); 417 418 if (error == 0) 419 error = copyout(&lim, uap->rlp, sizeof(*uap->rlp)); 420 return error; 421 } 422 423 /* 424 * Transform the running time and tick information in proc p into user, 425 * system, and interrupt time usage. 426 * 427 * Since we are limited to statclock tick granularity this is a statisical 428 * calculation which will be correct over the long haul, but should not be 429 * expected to measure fine grained deltas. 430 */ 431 void 432 calcru(struct proc *p, struct timeval *up, struct timeval *sp, 433 struct timeval *ip) 434 { 435 struct thread *td = p->p_thread; 436 int s; 437 438 /* 439 * Calculate at the statclock level. YYY if the thread is owned by 440 * another cpu we need to forward the request to the other cpu, or 441 * have a token to interlock the information. 442 */ 443 s = splstatclock(); 444 up->tv_sec = td->td_uticks / 1000000; 445 up->tv_usec = td->td_uticks % 1000000; 446 sp->tv_sec = td->td_sticks / 1000000; 447 sp->tv_usec = td->td_sticks % 1000000; 448 if (ip != NULL) { 449 ip->tv_sec = td->td_iticks / 1000000; 450 ip->tv_usec = td->td_iticks % 1000000; 451 } 452 splx(s); 453 } 454 455 /* ARGSUSED */ 456 int 457 getrusage(struct getrusage_args *uap) 458 { 459 struct proc *p = curproc; 460 struct rusage *rup; 461 462 switch (uap->who) { 463 464 case RUSAGE_SELF: 465 rup = &p->p_stats->p_ru; 466 calcru(p, &rup->ru_utime, &rup->ru_stime, NULL); 467 break; 468 469 case RUSAGE_CHILDREN: 470 rup = &p->p_stats->p_cru; 471 break; 472 473 default: 474 return (EINVAL); 475 } 476 return (copyout((caddr_t)rup, (caddr_t)uap->rusage, 477 sizeof (struct rusage))); 478 } 479 480 void 481 ruadd(struct rusage *ru, struct rusage *ru2) 482 { 483 long *ip, *ip2; 484 int i; 485 486 timevaladd(&ru->ru_utime, &ru2->ru_utime); 487 timevaladd(&ru->ru_stime, &ru2->ru_stime); 488 if (ru->ru_maxrss < ru2->ru_maxrss) 489 ru->ru_maxrss = ru2->ru_maxrss; 490 ip = &ru->ru_first; ip2 = &ru2->ru_first; 491 for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--) 492 *ip++ += *ip2++; 493 } 494 495 /* 496 * Make a copy of the plimit structure. 497 * We share these structures copy-on-write after fork, 498 * and copy when a limit is changed. 499 */ 500 struct plimit * 501 limcopy(struct plimit *lim) 502 { 503 struct plimit *copy; 504 505 MALLOC(copy, struct plimit *, sizeof(struct plimit), 506 M_SUBPROC, M_WAITOK); 507 bcopy(lim->pl_rlimit, copy->pl_rlimit, sizeof(struct plimit)); 508 copy->p_lflags = 0; 509 copy->p_refcnt = 1; 510 return (copy); 511 } 512 513 /* 514 * Find the uidinfo structure for a uid. This structure is used to 515 * track the total resource consumption (process count, socket buffer 516 * size, etc.) for the uid and impose limits. 517 */ 518 void 519 uihashinit(void) 520 { 521 uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash); 522 } 523 524 static struct uidinfo * 525 uilookup(uid_t uid) 526 { 527 struct uihashhead *uipp; 528 struct uidinfo *uip; 529 530 uipp = UIHASH(uid); 531 LIST_FOREACH(uip, uipp, ui_hash) { 532 if (uip->ui_uid == uid) 533 break; 534 } 535 return (uip); 536 } 537 538 static struct uidinfo * 539 uicreate(uid_t uid) 540 { 541 struct uidinfo *uip, *norace; 542 543 MALLOC(uip, struct uidinfo *, sizeof(*uip), M_UIDINFO, M_NOWAIT); 544 if (uip == NULL) { 545 MALLOC(uip, struct uidinfo *, sizeof(*uip), M_UIDINFO, M_WAITOK); 546 /* 547 * if we M_WAITOK we must look afterwards or risk 548 * redundant entries 549 */ 550 norace = uilookup(uid); 551 if (norace != NULL) { 552 FREE(uip, M_UIDINFO); 553 return (norace); 554 } 555 } 556 LIST_INSERT_HEAD(UIHASH(uid), uip, ui_hash); 557 uip->ui_uid = uid; 558 uip->ui_proccnt = 0; 559 uip->ui_sbsize = 0; 560 uip->ui_ref = 0; 561 varsymset_init(&uip->ui_varsymset, NULL); 562 return (uip); 563 } 564 565 struct uidinfo * 566 uifind(uid_t uid) 567 { 568 struct uidinfo *uip; 569 570 uip = uilookup(uid); 571 if (uip == NULL) 572 uip = uicreate(uid); 573 uip->ui_ref++; 574 return (uip); 575 } 576 577 static __inline void 578 uifree(struct uidinfo *uip) 579 { 580 if (uip->ui_sbsize != 0) 581 /* XXX no %qd in kernel. Truncate. */ 582 printf("freeing uidinfo: uid = %d, sbsize = %ld\n", 583 uip->ui_uid, (long)uip->ui_sbsize); 584 if (uip->ui_proccnt != 0) 585 printf("freeing uidinfo: uid = %d, proccnt = %ld\n", 586 uip->ui_uid, uip->ui_proccnt); 587 LIST_REMOVE(uip, ui_hash); 588 varsymset_clean(&uip->ui_varsymset); 589 FREE(uip, M_UIDINFO); 590 } 591 592 void 593 uihold(struct uidinfo *uip) 594 { 595 ++uip->ui_ref; 596 KKASSERT(uip->ui_ref > 0); 597 } 598 599 void 600 uidrop(struct uidinfo *uip) 601 { 602 KKASSERT(uip->ui_ref > 0); 603 if (--uip->ui_ref == 0) 604 uifree(uip); 605 } 606 607 void 608 uireplace(struct uidinfo **puip, struct uidinfo *nuip) 609 { 610 uidrop(*puip); 611 *puip = nuip; 612 } 613 614 /* 615 * Change the count associated with number of processes 616 * a given user is using. When 'max' is 0, don't enforce a limit 617 */ 618 int 619 chgproccnt(struct uidinfo *uip, int diff, int max) 620 { 621 /* don't allow them to exceed max, but allow subtraction */ 622 if (diff > 0 && uip->ui_proccnt + diff > max && max != 0) 623 return (0); 624 uip->ui_proccnt += diff; 625 if (uip->ui_proccnt < 0) 626 printf("negative proccnt for uid = %d\n", uip->ui_uid); 627 return (1); 628 } 629 630 /* 631 * Change the total socket buffer size a user has used. 632 */ 633 int 634 chgsbsize(struct uidinfo *uip, u_long *hiwat, u_long to, rlim_t max) 635 { 636 rlim_t new; 637 int s; 638 639 s = splnet(); 640 new = uip->ui_sbsize + to - *hiwat; 641 /* don't allow them to exceed max, but allow subtraction */ 642 if (to > *hiwat && new > max) { 643 splx(s); 644 return (0); 645 } 646 uip->ui_sbsize = new; 647 *hiwat = to; 648 if (uip->ui_sbsize < 0) 649 printf("negative sbsize for uid = %d\n", uip->ui_uid); 650 splx(s); 651 return (1); 652 } 653 654