kern_prot.c revision 1.49
1 /* $NetBSD: kern_prot.c,v 1.49 1998/08/04 04:03:13 perry 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 51 #include <sys/param.h> 52 #include <sys/acct.h> 53 #include <sys/systm.h> 54 #include <sys/ucred.h> 55 #include <sys/proc.h> 56 #include <sys/timeb.h> 57 #include <sys/times.h> 58 #include <sys/malloc.h> 59 60 #include <sys/mount.h> 61 #include <sys/syscallargs.h> 62 63 /* ARGSUSED */ 64 int 65 sys_getpid(p, v, retval) 66 struct proc *p; 67 void *v; 68 register_t *retval; 69 { 70 71 *retval = p->p_pid; 72 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) || defined(COMPAT_IBCS2) || \ 73 defined(COMPAT_FREEBSD) 74 retval[1] = p->p_pptr->p_pid; 75 #endif 76 return (0); 77 } 78 79 /* ARGSUSED */ 80 int 81 sys_getppid(p, v, retval) 82 struct proc *p; 83 void *v; 84 register_t *retval; 85 { 86 87 *retval = p->p_pptr->p_pid; 88 return (0); 89 } 90 91 /* Get process group ID; note that POSIX getpgrp takes no parameter */ 92 int 93 sys_getpgrp(p, v, retval) 94 struct proc *p; 95 void *v; 96 register_t *retval; 97 { 98 99 *retval = p->p_pgrp->pg_id; 100 return (0); 101 } 102 103 /* 104 * Return the process group ID of the session leader (session ID) 105 * for the specified process. 106 */ 107 int 108 sys_getsid(p, v, retval) 109 struct proc *p; 110 void *v; 111 register_t *retval; 112 { 113 struct sys_getsid_args /* { 114 syscalldarg(pid_t) pid; 115 } */ *uap = v; 116 117 if (SCARG(uap, pid) == 0) 118 goto found; 119 if ((p = pfind(SCARG(uap, pid))) == 0) 120 return (ESRCH); 121 found: 122 *retval = p->p_session->s_sid; 123 return 0; 124 } 125 126 int 127 sys_getpgid(p, v, retval) 128 struct proc *p; 129 void *v; 130 register_t *retval; 131 { 132 register struct sys_getpgid_args /* { 133 syscallarg(pid_t) pid; 134 } */ *uap = v; 135 136 if (SCARG(uap, pid) == 0) 137 goto found; 138 if ((p = pfind(SCARG(uap, pid))) == 0) 139 return (ESRCH); 140 found: 141 *retval = p->p_pgid; 142 return 0; 143 } 144 145 /* ARGSUSED */ 146 int 147 sys_getuid(p, v, retval) 148 struct proc *p; 149 void *v; 150 register_t *retval; 151 { 152 153 *retval = p->p_cred->p_ruid; 154 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) || defined(COMPAT_IBCS2) || \ 155 defined(COMPAT_FREEBSD) 156 retval[1] = p->p_ucred->cr_uid; 157 #endif 158 return (0); 159 } 160 161 /* ARGSUSED */ 162 int 163 sys_geteuid(p, v, retval) 164 struct proc *p; 165 void *v; 166 register_t *retval; 167 { 168 169 *retval = p->p_ucred->cr_uid; 170 return (0); 171 } 172 173 /* ARGSUSED */ 174 int 175 sys_getgid(p, v, retval) 176 struct proc *p; 177 void *v; 178 register_t *retval; 179 { 180 181 *retval = p->p_cred->p_rgid; 182 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) || defined(COMPAT_FREEBSD) 183 retval[1] = p->p_ucred->cr_gid; 184 #endif 185 return (0); 186 } 187 188 /* 189 * Get effective group ID. The "egid" is groups[0], and could be obtained 190 * via getgroups. This syscall exists because it is somewhat painful to do 191 * correctly in a library function. 192 */ 193 /* ARGSUSED */ 194 int 195 sys_getegid(p, v, retval) 196 struct proc *p; 197 void *v; 198 register_t *retval; 199 { 200 201 *retval = p->p_ucred->cr_gid; 202 return (0); 203 } 204 205 int 206 sys_getgroups(p, v, retval) 207 struct proc *p; 208 void *v; 209 register_t *retval; 210 { 211 register struct sys_getgroups_args /* { 212 syscallarg(int) gidsetsize; 213 syscallarg(gid_t *) gidset; 214 } */ *uap = v; 215 register struct pcred *pc = p->p_cred; 216 register int ngrp; 217 int error; 218 219 ngrp = SCARG(uap, gidsetsize); 220 if (ngrp == 0) { 221 *retval = pc->pc_ucred->cr_ngroups; 222 return (0); 223 } 224 if (ngrp < pc->pc_ucred->cr_ngroups) 225 return (EINVAL); 226 ngrp = pc->pc_ucred->cr_ngroups; 227 error = copyout((caddr_t)pc->pc_ucred->cr_groups, 228 (caddr_t)SCARG(uap, gidset), ngrp * sizeof(gid_t)); 229 if (error) 230 return (error); 231 *retval = ngrp; 232 return (0); 233 } 234 235 /* ARGSUSED */ 236 int 237 sys_setsid(p, v, retval) 238 register struct proc *p; 239 void *v; 240 register_t *retval; 241 { 242 243 if (p->p_pgid == p->p_pid || pgfind(p->p_pid)) { 244 return (EPERM); 245 } else { 246 (void)enterpgrp(p, p->p_pid, 1); 247 *retval = p->p_pid; 248 return (0); 249 } 250 } 251 252 /* 253 * set process group (setpgid/old setpgrp) 254 * 255 * caller does setpgid(targpid, targpgid) 256 * 257 * pgid must be in valid range (EINVAL) 258 * pid must be caller or child of caller (ESRCH) 259 * if a child 260 * pid must be in same session (EPERM) 261 * pid can't have done an exec (EACCES) 262 * if pgid != pid 263 * there must exist some pid in same session having pgid (EPERM) 264 * pid must not be session leader (EPERM) 265 */ 266 /* ARGSUSED */ 267 int 268 sys_setpgid(curp, v, retval) 269 struct proc *curp; 270 void *v; 271 register_t *retval; 272 { 273 register struct sys_setpgid_args /* { 274 syscallarg(int) pid; 275 syscallarg(int) pgid; 276 } */ *uap = v; 277 register struct proc *targp; /* target process */ 278 register struct pgrp *pgrp; /* target pgrp */ 279 280 if (SCARG(uap, pgid) < 0) 281 return (EINVAL); 282 283 if (SCARG(uap, pid) != 0 && SCARG(uap, pid) != curp->p_pid) { 284 if ((targp = pfind(SCARG(uap, pid))) == 0 || !inferior(targp)) 285 return (ESRCH); 286 if (targp->p_session != curp->p_session) 287 return (EPERM); 288 if (targp->p_flag & P_EXEC) 289 return (EACCES); 290 } else 291 targp = curp; 292 if (SESS_LEADER(targp)) 293 return (EPERM); 294 if (SCARG(uap, pgid) == 0) 295 SCARG(uap, pgid) = targp->p_pid; 296 else if (SCARG(uap, pgid) != targp->p_pid) 297 if ((pgrp = pgfind(SCARG(uap, pgid))) == 0 || 298 pgrp->pg_session != curp->p_session) 299 return (EPERM); 300 return (enterpgrp(targp, SCARG(uap, pgid), 0)); 301 } 302 303 /* ARGSUSED */ 304 int 305 sys_setuid(p, v, retval) 306 struct proc *p; 307 void *v; 308 register_t *retval; 309 { 310 struct sys_setuid_args /* { 311 syscallarg(uid_t) uid; 312 } */ *uap = v; 313 register struct pcred *pc = p->p_cred; 314 register uid_t uid; 315 int error; 316 317 uid = SCARG(uap, uid); 318 if (uid != pc->p_ruid && 319 (error = suser(pc->pc_ucred, &p->p_acflag))) 320 return (error); 321 /* 322 * Everything's okay, do it. 323 * Transfer proc count to new user. 324 * Copy credentials so other references do not see our changes. 325 */ 326 (void)chgproccnt(pc->p_ruid, -1); 327 (void)chgproccnt(uid, 1); 328 pc->pc_ucred = crcopy(pc->pc_ucred); 329 pc->pc_ucred->cr_uid = uid; 330 pc->p_ruid = uid; 331 pc->p_svuid = uid; 332 p->p_flag |= P_SUGID; 333 return (0); 334 } 335 336 /* ARGSUSED */ 337 int 338 sys_seteuid(p, v, retval) 339 struct proc *p; 340 void *v; 341 register_t *retval; 342 { 343 struct sys_seteuid_args /* { 344 syscallarg(uid_t) euid; 345 } */ *uap = v; 346 register struct pcred *pc = p->p_cred; 347 register uid_t euid; 348 int error; 349 350 euid = SCARG(uap, euid); 351 if (euid != pc->p_ruid && euid != pc->p_svuid && 352 (error = suser(pc->pc_ucred, &p->p_acflag))) 353 return (error); 354 /* 355 * Everything's okay, do it. Copy credentials so other references do 356 * not see our changes. 357 */ 358 pc->pc_ucred = crcopy(pc->pc_ucred); 359 pc->pc_ucred->cr_uid = euid; 360 p->p_flag |= P_SUGID; 361 return (0); 362 } 363 364 int 365 sys_setreuid(p, v, retval) 366 struct proc *p; 367 void *v; 368 register_t *retval; 369 { 370 struct sys_setreuid_args /* { 371 syscallarg(uid_t) ruid; 372 syscallarg(uid_t) euid; 373 } */ *uap = v; 374 register struct pcred *pc = p->p_cred; 375 register uid_t ruid, euid; 376 int error; 377 378 ruid = SCARG(uap, ruid); 379 euid = SCARG(uap, euid); 380 381 if (ruid != (uid_t)-1 && 382 ruid != pc->p_ruid && ruid != pc->pc_ucred->cr_uid && 383 (error = suser(pc->pc_ucred, &p->p_acflag))) 384 return (error); 385 386 if (euid != (uid_t)-1 && 387 euid != pc->p_ruid && euid != pc->pc_ucred->cr_uid && 388 euid != pc->p_svuid && 389 (error = suser(pc->pc_ucred, &p->p_acflag))) 390 return (error); 391 392 if (euid != (uid_t)-1) { 393 pc->pc_ucred = crcopy(pc->pc_ucred); 394 pc->pc_ucred->cr_uid = euid; 395 } 396 397 if (ruid != (uid_t)-1) { 398 (void)chgproccnt(pc->p_ruid, -1); 399 (void)chgproccnt(ruid, 1); 400 pc->p_ruid = ruid; 401 pc->p_svuid = pc->pc_ucred->cr_uid; 402 } 403 404 if (euid != (uid_t)-1 && ruid != (uid_t)-1) 405 p->p_flag |= P_SUGID; 406 return (0); 407 } 408 409 /* ARGSUSED */ 410 int 411 sys_setgid(p, v, retval) 412 struct proc *p; 413 void *v; 414 register_t *retval; 415 { 416 struct sys_setgid_args /* { 417 syscallarg(gid_t) gid; 418 } */ *uap = v; 419 register struct pcred *pc = p->p_cred; 420 register gid_t gid; 421 int error; 422 423 gid = SCARG(uap, gid); 424 if (gid != pc->p_rgid && 425 (error = suser(pc->pc_ucred, &p->p_acflag))) 426 return (error); 427 pc->pc_ucred = crcopy(pc->pc_ucred); 428 pc->pc_ucred->cr_gid = gid; 429 pc->p_rgid = gid; 430 pc->p_svgid = gid; 431 p->p_flag |= P_SUGID; 432 return (0); 433 } 434 435 /* ARGSUSED */ 436 int 437 sys_setegid(p, v, retval) 438 struct proc *p; 439 void *v; 440 register_t *retval; 441 { 442 struct sys_setegid_args /* { 443 syscallarg(gid_t) egid; 444 } */ *uap = v; 445 register struct pcred *pc = p->p_cred; 446 register gid_t egid; 447 int error; 448 449 egid = SCARG(uap, egid); 450 if (egid != pc->p_rgid && egid != pc->p_svgid && 451 (error = suser(pc->pc_ucred, &p->p_acflag))) 452 return (error); 453 pc->pc_ucred = crcopy(pc->pc_ucred); 454 pc->pc_ucred->cr_gid = egid; 455 p->p_flag |= P_SUGID; 456 return (0); 457 } 458 459 int 460 sys_setregid(p, v, retval) 461 struct proc *p; 462 void *v; 463 register_t *retval; 464 { 465 struct sys_setregid_args /* { 466 syscallarg(gid_t) rgid; 467 syscallarg(gid_t) egid; 468 } */ *uap = v; 469 register struct pcred *pc = p->p_cred; 470 register gid_t rgid, egid; 471 int error; 472 473 rgid = SCARG(uap, rgid); 474 egid = SCARG(uap, egid); 475 476 if (rgid != (gid_t)-1 && 477 rgid != pc->p_rgid && rgid != pc->pc_ucred->cr_gid && 478 (error = suser(pc->pc_ucred, &p->p_acflag))) 479 return (error); 480 481 if (egid != (gid_t)-1 && 482 egid != pc->p_rgid && egid != pc->pc_ucred->cr_gid && 483 egid != pc->p_svgid && 484 (error = suser(pc->pc_ucred, &p->p_acflag))) 485 return (error); 486 487 if (egid != (gid_t)-1) { 488 pc->pc_ucred = crcopy(pc->pc_ucred); 489 pc->pc_ucred->cr_gid = egid; 490 } 491 492 if (rgid != (gid_t)-1) { 493 pc->p_rgid = rgid; 494 pc->p_svgid = pc->pc_ucred->cr_gid; 495 } 496 497 if (egid != (gid_t)-1 && rgid != (gid_t)-1) 498 p->p_flag |= P_SUGID; 499 return (0); 500 } 501 502 /* ARGSUSED */ 503 int 504 sys_setgroups(p, v, retval) 505 struct proc *p; 506 void *v; 507 register_t *retval; 508 { 509 struct sys_setgroups_args /* { 510 syscallarg(int) gidsetsize; 511 syscallarg(const gid_t *) gidset; 512 } */ *uap = v; 513 register struct pcred *pc = p->p_cred; 514 register int ngrp; 515 int error; 516 517 if ((error = suser(pc->pc_ucred, &p->p_acflag)) != 0) 518 return (error); 519 ngrp = SCARG(uap, gidsetsize); 520 if ((u_int)ngrp > NGROUPS) 521 return (EINVAL); 522 pc->pc_ucred = crcopy(pc->pc_ucred); 523 error = copyin(SCARG(uap, gidset), pc->pc_ucred->cr_groups, 524 ngrp * sizeof(gid_t)); 525 if (error) 526 return (error); 527 pc->pc_ucred->cr_ngroups = ngrp; 528 p->p_flag |= P_SUGID; 529 return (0); 530 } 531 532 /* 533 * Check if gid is a member of the group set. 534 */ 535 int 536 groupmember(gid, cred) 537 gid_t gid; 538 register struct ucred *cred; 539 { 540 register gid_t *gp; 541 gid_t *egp; 542 543 egp = &(cred->cr_groups[cred->cr_ngroups]); 544 for (gp = cred->cr_groups; gp < egp; gp++) 545 if (*gp == gid) 546 return (1); 547 return (0); 548 } 549 550 /* 551 * Test whether the specified credentials imply "super-user" 552 * privilege; if so, and we have accounting info, set the flag 553 * indicating use of super-powers. 554 * Returns 0 or error. 555 */ 556 int 557 suser(cred, acflag) 558 struct ucred *cred; 559 u_short *acflag; 560 { 561 if (cred->cr_uid == 0) { 562 if (acflag) 563 *acflag |= ASU; 564 return (0); 565 } 566 return (EPERM); 567 } 568 569 /* 570 * Allocate a zeroed cred structure. 571 */ 572 struct ucred * 573 crget() 574 { 575 register struct ucred *cr; 576 577 MALLOC(cr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK); 578 memset((caddr_t)cr, 0, sizeof(*cr)); 579 cr->cr_ref = 1; 580 return (cr); 581 } 582 583 /* 584 * Free a cred structure. 585 * Throws away space when ref count gets to 0. 586 */ 587 void 588 crfree(cr) 589 struct ucred *cr; 590 { 591 int s; 592 593 s = splimp(); /* ??? */ 594 if (--cr->cr_ref == 0) 595 FREE((caddr_t)cr, M_CRED); 596 (void) splx(s); 597 } 598 599 /* 600 * Copy cred structure to a new one and free the old one. 601 */ 602 struct ucred * 603 crcopy(cr) 604 struct ucred *cr; 605 { 606 struct ucred *newcr; 607 608 if (cr->cr_ref == 1) 609 return (cr); 610 newcr = crget(); 611 *newcr = *cr; 612 crfree(cr); 613 newcr->cr_ref = 1; 614 return (newcr); 615 } 616 617 /* 618 * Dup cred struct to a new held one. 619 */ 620 struct ucred * 621 crdup(cr) 622 struct ucred *cr; 623 { 624 struct ucred *newcr; 625 626 newcr = crget(); 627 *newcr = *cr; 628 newcr->cr_ref = 1; 629 return (newcr); 630 } 631 632 /* 633 * Get login name, if available. 634 */ 635 /* ARGSUSED */ 636 int 637 sys___getlogin(p, v, retval) 638 struct proc *p; 639 void *v; 640 register_t *retval; 641 { 642 struct sys___getlogin_args /* { 643 syscallarg(char *) namebuf; 644 syscallarg(u_int) namelen; 645 } */ *uap = v; 646 647 if (SCARG(uap, namelen) > sizeof(p->p_pgrp->pg_session->s_login)) 648 SCARG(uap, namelen) = sizeof(p->p_pgrp->pg_session->s_login); 649 return (copyout((caddr_t) p->p_pgrp->pg_session->s_login, 650 (caddr_t) SCARG(uap, namebuf), SCARG(uap, namelen))); 651 } 652 653 /* 654 * Set login name. 655 */ 656 /* ARGSUSED */ 657 int 658 sys_setlogin(p, v, retval) 659 struct proc *p; 660 void *v; 661 register_t *retval; 662 { 663 struct sys_setlogin_args /* { 664 syscallarg(const char *) namebuf; 665 } */ *uap = v; 666 int error; 667 668 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 669 return (error); 670 error = copyinstr(SCARG(uap, namebuf), p->p_pgrp->pg_session->s_login, 671 sizeof(p->p_pgrp->pg_session->s_login) - 1, (size_t *)0); 672 if (error == ENAMETOOLONG) 673 error = EINVAL; 674 return (error); 675 } 676
Indexes created Tue Sep 23 14:10:03 GMT 2025