kern_prot.c revision 1.53.2.2
1 /* $NetBSD: kern_prot.c,v 1.53.2.2 2000/10/06 15:35:10 he Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1989, 1990, 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. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)kern_prot.c 8.9 (Berkeley) 2/14/95 41 */ 42 43 /* 44 * System calls related to processes and protection 45 */ 46 47 #include "opt_compat_freebsd.h" 48 #include "opt_compat_ibcs2.h" 49 #include "opt_compat_sunos.h" 50 #include "opt_compat_linux.h" 51 #include "opt_compat_43.h" 52 #include "opt_compat_osf1.h" 53 54 #include <sys/param.h> 55 #include <sys/acct.h> 56 #include <sys/systm.h> 57 #include <sys/ucred.h> 58 #include <sys/proc.h> 59 #include <sys/timeb.h> 60 #include <sys/times.h> 61 #include <sys/malloc.h> 62 63 #include <sys/mount.h> 64 #include <sys/syscallargs.h> 65 66 /* ARGSUSED */ 67 int 68 sys_getpid(p, v, retval) 69 struct proc *p; 70 void *v; 71 register_t *retval; 72 { 73 74 *retval = p->p_pid; 75 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) || defined(COMPAT_IBCS2) || \ 76 defined(COMPAT_FREEBSD) || defined(COMPAT_OSF1) || \ 77 (defined(COMPAT_LINUX) && defined(__alpha__)) 78 retval[1] = p->p_pptr->p_pid; 79 #endif 80 return (0); 81 } 82 83 /* ARGSUSED */ 84 int 85 sys_getppid(p, v, retval) 86 struct proc *p; 87 void *v; 88 register_t *retval; 89 { 90 91 *retval = p->p_pptr->p_pid; 92 return (0); 93 } 94 95 /* Get process group ID; note that POSIX getpgrp takes no parameter */ 96 int 97 sys_getpgrp(p, v, retval) 98 struct proc *p; 99 void *v; 100 register_t *retval; 101 { 102 103 *retval = p->p_pgrp->pg_id; 104 return (0); 105 } 106 107 /* 108 * Return the process group ID of the session leader (session ID) 109 * for the specified process. 110 */ 111 int 112 sys_getsid(p, v, retval) 113 struct proc *p; 114 void *v; 115 register_t *retval; 116 { 117 struct sys_getsid_args /* { 118 syscalldarg(pid_t) pid; 119 } */ *uap = v; 120 121 if (SCARG(uap, pid) == 0) 122 goto found; 123 if ((p = pfind(SCARG(uap, pid))) == 0) 124 return (ESRCH); 125 found: 126 *retval = p->p_session->s_sid; 127 return 0; 128 } 129 130 int 131 sys_getpgid(p, v, retval) 132 struct proc *p; 133 void *v; 134 register_t *retval; 135 { 136 register struct sys_getpgid_args /* { 137 syscallarg(pid_t) pid; 138 } */ *uap = v; 139 140 if (SCARG(uap, pid) == 0) 141 goto found; 142 if ((p = pfind(SCARG(uap, pid))) == 0) 143 return (ESRCH); 144 found: 145 *retval = p->p_pgid; 146 return 0; 147 } 148 149 /* ARGSUSED */ 150 int 151 sys_getuid(p, v, retval) 152 struct proc *p; 153 void *v; 154 register_t *retval; 155 { 156 157 *retval = p->p_cred->p_ruid; 158 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) || defined(COMPAT_IBCS2) || \ 159 defined(COMPAT_FREEBSD) || defined(COMPAT_OSF1) || \ 160 (defined(COMPAT_LINUX) && defined(__alpha__)) 161 retval[1] = p->p_ucred->cr_uid; 162 #endif 163 return (0); 164 } 165 166 /* ARGSUSED */ 167 int 168 sys_geteuid(p, v, retval) 169 struct proc *p; 170 void *v; 171 register_t *retval; 172 { 173 174 *retval = p->p_ucred->cr_uid; 175 return (0); 176 } 177 178 /* ARGSUSED */ 179 int 180 sys_getgid(p, v, retval) 181 struct proc *p; 182 void *v; 183 register_t *retval; 184 { 185 186 *retval = p->p_cred->p_rgid; 187 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) || defined(COMPAT_FREEBSD) || \ 188 defined(COMPAT_OSF1) || (defined(COMPAT_LINUX) && defined(alpha)) 189 retval[1] = p->p_ucred->cr_gid; 190 #endif 191 return (0); 192 } 193 194 /* 195 * Get effective group ID. The "egid" is groups[0], and could be obtained 196 * via getgroups. This syscall exists because it is somewhat painful to do 197 * correctly in a library function. 198 */ 199 /* ARGSUSED */ 200 int 201 sys_getegid(p, v, retval) 202 struct proc *p; 203 void *v; 204 register_t *retval; 205 { 206 207 *retval = p->p_ucred->cr_gid; 208 return (0); 209 } 210 211 int 212 sys_getgroups(p, v, retval) 213 struct proc *p; 214 void *v; 215 register_t *retval; 216 { 217 register struct sys_getgroups_args /* { 218 syscallarg(int) gidsetsize; 219 syscallarg(gid_t *) gidset; 220 } */ *uap = v; 221 register struct pcred *pc = p->p_cred; 222 register int ngrp; 223 int error; 224 225 ngrp = SCARG(uap, gidsetsize); 226 if (ngrp == 0) { 227 *retval = pc->pc_ucred->cr_ngroups; 228 return (0); 229 } 230 if (ngrp < pc->pc_ucred->cr_ngroups) 231 return (EINVAL); 232 ngrp = pc->pc_ucred->cr_ngroups; 233 error = copyout((caddr_t)pc->pc_ucred->cr_groups, 234 (caddr_t)SCARG(uap, gidset), ngrp * sizeof(gid_t)); 235 if (error) 236 return (error); 237 *retval = ngrp; 238 return (0); 239 } 240 241 /* ARGSUSED */ 242 int 243 sys_setsid(p, v, retval) 244 register struct proc *p; 245 void *v; 246 register_t *retval; 247 { 248 249 if (p->p_pgid == p->p_pid || pgfind(p->p_pid)) { 250 return (EPERM); 251 } else { 252 (void)enterpgrp(p, p->p_pid, 1); 253 *retval = p->p_pid; 254 return (0); 255 } 256 } 257 258 /* 259 * set process group (setpgid/old setpgrp) 260 * 261 * caller does setpgid(targpid, targpgid) 262 * 263 * pgid must be in valid range (EINVAL) 264 * pid must be caller or child of caller (ESRCH) 265 * if a child 266 * pid must be in same session (EPERM) 267 * pid can't have done an exec (EACCES) 268 * if pgid != pid 269 * there must exist some pid in same session having pgid (EPERM) 270 * pid must not be session leader (EPERM) 271 */ 272 /* ARGSUSED */ 273 int 274 sys_setpgid(curp, v, retval) 275 struct proc *curp; 276 void *v; 277 register_t *retval; 278 { 279 register struct sys_setpgid_args /* { 280 syscallarg(int) pid; 281 syscallarg(int) pgid; 282 } */ *uap = v; 283 register struct proc *targp; /* target process */ 284 register struct pgrp *pgrp; /* target pgrp */ 285 286 if (SCARG(uap, pgid) < 0) 287 return (EINVAL); 288 289 if (SCARG(uap, pid) != 0 && SCARG(uap, pid) != curp->p_pid) { 290 if ((targp = pfind(SCARG(uap, pid))) == 0 || !inferior(targp)) 291 return (ESRCH); 292 if (targp->p_session != curp->p_session) 293 return (EPERM); 294 if (targp->p_flag & P_EXEC) 295 return (EACCES); 296 } else 297 targp = curp; 298 if (SESS_LEADER(targp)) 299 return (EPERM); 300 if (SCARG(uap, pgid) == 0) 301 SCARG(uap, pgid) = targp->p_pid; 302 else if (SCARG(uap, pgid) != targp->p_pid) 303 if ((pgrp = pgfind(SCARG(uap, pgid))) == 0 || 304 pgrp->pg_session != curp->p_session) 305 return (EPERM); 306 return (enterpgrp(targp, SCARG(uap, pgid), 0)); 307 } 308 309 /* ARGSUSED */ 310 int 311 sys_setuid(p, v, retval) 312 struct proc *p; 313 void *v; 314 register_t *retval; 315 { 316 struct sys_setuid_args /* { 317 syscallarg(uid_t) uid; 318 } */ *uap = v; 319 register struct pcred *pc = p->p_cred; 320 register uid_t uid; 321 int error; 322 323 uid = SCARG(uap, uid); 324 if (uid != pc->p_ruid && 325 (error = suser(pc->pc_ucred, &p->p_acflag))) 326 return (error); 327 /* 328 * Everything's okay, do it. 329 * Transfer proc count to new user. 330 * Copy credentials so other references do not see our changes. 331 */ 332 (void)chgproccnt(pc->p_ruid, -1); 333 (void)chgproccnt(uid, 1); 334 pc->pc_ucred = crcopy(pc->pc_ucred); 335 pc->pc_ucred->cr_uid = uid; 336 pc->p_ruid = uid; 337 pc->p_svuid = uid; 338 p->p_flag |= P_SUGID; 339 return (0); 340 } 341 342 /* ARGSUSED */ 343 int 344 sys_seteuid(p, v, retval) 345 struct proc *p; 346 void *v; 347 register_t *retval; 348 { 349 struct sys_seteuid_args /* { 350 syscallarg(uid_t) euid; 351 } */ *uap = v; 352 register struct pcred *pc = p->p_cred; 353 register uid_t euid; 354 int error; 355 356 euid = SCARG(uap, euid); 357 if (euid != pc->p_ruid && euid != pc->p_svuid && 358 (error = suser(pc->pc_ucred, &p->p_acflag))) 359 return (error); 360 /* 361 * Everything's okay, do it. Copy credentials so other references do 362 * not see our changes. 363 */ 364 pc->pc_ucred = crcopy(pc->pc_ucred); 365 pc->pc_ucred->cr_uid = euid; 366 p->p_flag |= P_SUGID; 367 return (0); 368 } 369 370 int 371 sys_setreuid(p, v, retval) 372 struct proc *p; 373 void *v; 374 register_t *retval; 375 { 376 struct sys_setreuid_args /* { 377 syscallarg(uid_t) ruid; 378 syscallarg(uid_t) euid; 379 } */ *uap = v; 380 register struct pcred *pc = p->p_cred; 381 register uid_t ruid, euid; 382 int error; 383 384 ruid = SCARG(uap, ruid); 385 euid = SCARG(uap, euid); 386 387 if (ruid != (uid_t)-1 && 388 ruid != pc->p_ruid && ruid != pc->pc_ucred->cr_uid && 389 (error = suser(pc->pc_ucred, &p->p_acflag))) 390 return (error); 391 392 if (euid != (uid_t)-1 && 393 euid != pc->p_ruid && euid != pc->pc_ucred->cr_uid && 394 euid != pc->p_svuid && 395 (error = suser(pc->pc_ucred, &p->p_acflag))) 396 return (error); 397 398 if (euid != (uid_t)-1) { 399 pc->pc_ucred = crcopy(pc->pc_ucred); 400 pc->pc_ucred->cr_uid = euid; 401 } 402 403 if (ruid != (uid_t)-1) { 404 (void)chgproccnt(pc->p_ruid, -1); 405 (void)chgproccnt(ruid, 1); 406 pc->p_ruid = ruid; 407 pc->p_svuid = pc->pc_ucred->cr_uid; 408 } 409 410 if (euid != (uid_t)-1 && ruid != (uid_t)-1) 411 p->p_flag |= P_SUGID; 412 return (0); 413 } 414 415 /* ARGSUSED */ 416 int 417 sys_setgid(p, v, retval) 418 struct proc *p; 419 void *v; 420 register_t *retval; 421 { 422 struct sys_setgid_args /* { 423 syscallarg(gid_t) gid; 424 } */ *uap = v; 425 register struct pcred *pc = p->p_cred; 426 register gid_t gid; 427 int error; 428 429 gid = SCARG(uap, gid); 430 if (gid != pc->p_rgid && 431 (error = suser(pc->pc_ucred, &p->p_acflag))) 432 return (error); 433 pc->pc_ucred = crcopy(pc->pc_ucred); 434 pc->pc_ucred->cr_gid = gid; 435 pc->p_rgid = gid; 436 pc->p_svgid = gid; 437 p->p_flag |= P_SUGID; 438 return (0); 439 } 440 441 /* ARGSUSED */ 442 int 443 sys_setegid(p, v, retval) 444 struct proc *p; 445 void *v; 446 register_t *retval; 447 { 448 struct sys_setegid_args /* { 449 syscallarg(gid_t) egid; 450 } */ *uap = v; 451 register struct pcred *pc = p->p_cred; 452 register gid_t egid; 453 int error; 454 455 egid = SCARG(uap, egid); 456 if (egid != pc->p_rgid && egid != pc->p_svgid && 457 (error = suser(pc->pc_ucred, &p->p_acflag))) 458 return (error); 459 pc->pc_ucred = crcopy(pc->pc_ucred); 460 pc->pc_ucred->cr_gid = egid; 461 p->p_flag |= P_SUGID; 462 return (0); 463 } 464 465 int 466 sys_setregid(p, v, retval) 467 struct proc *p; 468 void *v; 469 register_t *retval; 470 { 471 struct sys_setregid_args /* { 472 syscallarg(gid_t) rgid; 473 syscallarg(gid_t) egid; 474 } */ *uap = v; 475 register struct pcred *pc = p->p_cred; 476 register gid_t rgid, egid; 477 int error; 478 479 rgid = SCARG(uap, rgid); 480 egid = SCARG(uap, egid); 481 482 if (rgid != (gid_t)-1 && 483 rgid != pc->p_rgid && rgid != pc->pc_ucred->cr_gid && 484 (error = suser(pc->pc_ucred, &p->p_acflag))) 485 return (error); 486 487 if (egid != (gid_t)-1 && 488 egid != pc->p_rgid && egid != pc->pc_ucred->cr_gid && 489 egid != pc->p_svgid && 490 (error = suser(pc->pc_ucred, &p->p_acflag))) 491 return (error); 492 493 if (egid != (gid_t)-1) { 494 pc->pc_ucred = crcopy(pc->pc_ucred); 495 pc->pc_ucred->cr_gid = egid; 496 } 497 498 if (rgid != (gid_t)-1) { 499 pc->p_rgid = rgid; 500 pc->p_svgid = pc->pc_ucred->cr_gid; 501 } 502 503 if (egid != (gid_t)-1 && rgid != (gid_t)-1) 504 p->p_flag |= P_SUGID; 505 return (0); 506 } 507 508 int 509 sys_issetugid(p, v, retval) 510 struct proc *p; 511 void *v; 512 register_t *retval; 513 { 514 /* 515 * Note: OpenBSD sets a P_SUGIDEXEC flag set at execve() time, 516 * we use P_SUGID because we consider changing the owners as 517 * "tainting" as well. 518 * This is significant for procs that start as root and "become" 519 * a user without an exec - programs cannot know *everything* 520 * that libc *might* have put in their data segment. 521 */ 522 *retval = (p->p_flag & P_SUGID) != 0; 523 return 0; 524 } 525 526 /* ARGSUSED */ 527 int 528 sys_setgroups(p, v, retval) 529 struct proc *p; 530 void *v; 531 register_t *retval; 532 { 533 struct sys_setgroups_args /* { 534 syscallarg(int) gidsetsize; 535 syscallarg(const gid_t *) gidset; 536 } */ *uap = v; 537 register struct pcred *pc = p->p_cred; 538 register int ngrp; 539 int error; 540 541 if ((error = suser(pc->pc_ucred, &p->p_acflag)) != 0) 542 return (error); 543 ngrp = SCARG(uap, gidsetsize); 544 if ((u_int)ngrp > NGROUPS) 545 return (EINVAL); 546 pc->pc_ucred = crcopy(pc->pc_ucred); 547 error = copyin(SCARG(uap, gidset), pc->pc_ucred->cr_groups, 548 ngrp * sizeof(gid_t)); 549 if (error) 550 return (error); 551 pc->pc_ucred->cr_ngroups = ngrp; 552 p->p_flag |= P_SUGID; 553 return (0); 554 } 555 556 /* 557 * Check if gid is a member of the group set. 558 */ 559 int 560 groupmember(gid, cred) 561 gid_t gid; 562 register struct ucred *cred; 563 { 564 register gid_t *gp; 565 gid_t *egp; 566 567 egp = &(cred->cr_groups[cred->cr_ngroups]); 568 for (gp = cred->cr_groups; gp < egp; gp++) 569 if (*gp == gid) 570 return (1); 571 return (0); 572 } 573 574 /* 575 * Test whether the specified credentials imply "super-user" 576 * privilege; if so, and we have accounting info, set the flag 577 * indicating use of super-powers. 578 * Returns 0 or error. 579 */ 580 int 581 suser(cred, acflag) 582 struct ucred *cred; 583 u_short *acflag; 584 { 585 if (cred->cr_uid == 0) { 586 if (acflag) 587 *acflag |= ASU; 588 return (0); 589 } 590 return (EPERM); 591 } 592 593 /* 594 * Allocate a zeroed cred structure. 595 */ 596 struct ucred * 597 crget() 598 { 599 register struct ucred *cr; 600 601 MALLOC(cr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK); 602 memset((caddr_t)cr, 0, sizeof(*cr)); 603 cr->cr_ref = 1; 604 return (cr); 605 } 606 607 /* 608 * Free a cred structure. 609 * Throws away space when ref count gets to 0. 610 */ 611 void 612 crfree(cr) 613 struct ucred *cr; 614 { 615 int s; 616 617 s = splimp(); /* ??? */ 618 if (--cr->cr_ref == 0) 619 FREE((caddr_t)cr, M_CRED); 620 (void) splx(s); 621 } 622 623 /* 624 * Copy cred structure to a new one and free the old one. 625 */ 626 struct ucred * 627 crcopy(cr) 628 struct ucred *cr; 629 { 630 struct ucred *newcr; 631 632 if (cr->cr_ref == 1) 633 return (cr); 634 newcr = crget(); 635 *newcr = *cr; 636 crfree(cr); 637 newcr->cr_ref = 1; 638 return (newcr); 639 } 640 641 /* 642 * Dup cred struct to a new held one. 643 */ 644 struct ucred * 645 crdup(cr) 646 struct ucred *cr; 647 { 648 struct ucred *newcr; 649 650 newcr = crget(); 651 *newcr = *cr; 652 newcr->cr_ref = 1; 653 return (newcr); 654 } 655 656 /* 657 * Get login name, if available. 658 */ 659 /* ARGSUSED */ 660 int 661 sys___getlogin(p, v, retval) 662 struct proc *p; 663 void *v; 664 register_t *retval; 665 { 666 struct sys___getlogin_args /* { 667 syscallarg(char *) namebuf; 668 syscallarg(size_t) namelen; 669 } */ *uap = v; 670 671 if (SCARG(uap, namelen) > sizeof(p->p_pgrp->pg_session->s_login)) 672 SCARG(uap, namelen) = sizeof(p->p_pgrp->pg_session->s_login); 673 return (copyout((caddr_t) p->p_pgrp->pg_session->s_login, 674 (caddr_t) SCARG(uap, namebuf), SCARG(uap, namelen))); 675 } 676 677 /* 678 * Set login name. 679 */ 680 /* ARGSUSED */ 681 int 682 sys_setlogin(p, v, retval) 683 struct proc *p; 684 void *v; 685 register_t *retval; 686 { 687 struct sys_setlogin_args /* { 688 syscallarg(const char *) namebuf; 689 } */ *uap = v; 690 int error; 691 692 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 693 return (error); 694 error = copyinstr(SCARG(uap, namebuf), p->p_pgrp->pg_session->s_login, 695 sizeof(p->p_pgrp->pg_session->s_login) - 1, (size_t *)0); 696 if (error == ENAMETOOLONG) 697 error = EINVAL; 698 return (error); 699 } 700
Indexes created Sat Sep 27 22:09:54 GMT 2025