1 /* 2 * Copyright (c) 1982, 1986, 1989, 1990, 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_prot.c 8.6 (Berkeley) 1/21/94 39 * $Id: kern_prot.c,v 1.33 1997/08/02 14:31:34 bde Exp $ 40 */ 41 42 /* 43 * System calls related to processes and protection 44 */ 45 46 #include <sys/param.h> 47 #include <sys/acct.h> 48 #include <sys/systm.h> 49 #include <sys/sysproto.h> 50 #include <sys/proc.h> 51 #include <sys/malloc.h> 52 #include <sys/unistd.h> 53 54 #ifndef _SYS_SYSPROTO_H_ 55 struct getpid_args { 56 int dummy; 57 }; 58 #endif 59 60 /* ARGSUSED */ 61 int 62 getpid(p, uap, retval) 63 struct proc *p; 64 struct getpid_args *uap; 65 int *retval; 66 { 67 68 *retval = p->p_pid; 69 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 70 retval[1] = p->p_pptr->p_pid; 71 #endif 72 return (0); 73 } 74 75 #ifndef _SYS_SYSPROTO_H_ 76 struct getppid_args { 77 int dummy; 78 }; 79 #endif 80 /* ARGSUSED */ 81 int 82 getppid(p, uap, retval) 83 struct proc *p; 84 struct getppid_args *uap; 85 int *retval; 86 { 87 88 *retval = p->p_pptr->p_pid; 89 return (0); 90 } 91 92 /* Get process group ID; note that POSIX getpgrp takes no parameter */ 93 #ifndef _SYS_SYSPROTO_H_ 94 struct getpgrp_args { 95 int dummy; 96 }; 97 #endif 98 99 int 100 getpgrp(p, uap, retval) 101 struct proc *p; 102 struct getpgrp_args *uap; 103 int *retval; 104 { 105 106 *retval = p->p_pgrp->pg_id; 107 return (0); 108 } 109 110 /* Get an arbitary pid's process group id */ 111 #ifndef _SYS_SYSPROTO_H_ 112 struct getpgid_args { 113 pid_t pid; 114 }; 115 #endif 116 117 int 118 getpgid(p, uap, retval) 119 struct proc *p; 120 struct getpgid_args *uap; 121 int *retval; 122 { 123 if (uap->pid == 0) 124 goto found; 125 126 if ((p == pfind(uap->pid)) == 0) 127 return ESRCH; 128 found: 129 *retval = p->p_pgrp->pg_id; 130 return 0; 131 } 132 133 /* 134 * Get an arbitary pid's session id. 135 */ 136 #ifndef _SYS_SYSPROTO_H_ 137 struct getsid_args { 138 pid_t pid; 139 }; 140 #endif 141 142 int 143 getsid(p, uap, retval) 144 struct proc *p; 145 struct getsid_args *uap; 146 int *retval; 147 { 148 if (uap->pid == 0) 149 goto found; 150 151 if ((p == pfind(uap->pid)) == 0) 152 return ESRCH; 153 found: 154 *retval = p->p_pgrp->pg_session->s_leader->p_pid; 155 return 0; 156 } 157 158 159 #ifndef _SYS_SYSPROTO_H_ 160 struct getuid_args { 161 int dummy; 162 }; 163 #endif 164 165 /* ARGSUSED */ 166 int 167 getuid(p, uap, retval) 168 struct proc *p; 169 struct getuid_args *uap; 170 int *retval; 171 { 172 173 *retval = p->p_cred->p_ruid; 174 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 175 retval[1] = p->p_ucred->cr_uid; 176 #endif 177 return (0); 178 } 179 180 #ifndef _SYS_SYSPROTO_H_ 181 struct geteuid_args { 182 int dummy; 183 }; 184 #endif 185 186 /* ARGSUSED */ 187 int 188 geteuid(p, uap, retval) 189 struct proc *p; 190 struct geteuid_args *uap; 191 int *retval; 192 { 193 194 *retval = p->p_ucred->cr_uid; 195 return (0); 196 } 197 198 #ifndef _SYS_SYSPROTO_H_ 199 struct getgid_args { 200 int dummy; 201 }; 202 #endif 203 204 /* ARGSUSED */ 205 int 206 getgid(p, uap, retval) 207 struct proc *p; 208 struct getgid_args *uap; 209 int *retval; 210 { 211 212 *retval = p->p_cred->p_rgid; 213 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 214 retval[1] = p->p_ucred->cr_groups[0]; 215 #endif 216 return (0); 217 } 218 219 /* 220 * Get effective group ID. The "egid" is groups[0], and could be obtained 221 * via getgroups. This syscall exists because it is somewhat painful to do 222 * correctly in a library function. 223 */ 224 #ifndef _SYS_SYSPROTO_H_ 225 struct getegid_args { 226 int dummy; 227 }; 228 #endif 229 230 /* ARGSUSED */ 231 int 232 getegid(p, uap, retval) 233 struct proc *p; 234 struct getegid_args *uap; 235 int *retval; 236 { 237 238 *retval = p->p_ucred->cr_groups[0]; 239 return (0); 240 } 241 242 #ifndef _SYS_SYSPROTO_H_ 243 struct getgroups_args { 244 u_int gidsetsize; 245 gid_t *gidset; 246 }; 247 #endif 248 int 249 getgroups(p, uap, retval) 250 struct proc *p; 251 register struct getgroups_args *uap; 252 int *retval; 253 { 254 register struct pcred *pc = p->p_cred; 255 register u_int ngrp; 256 int error; 257 258 if ((ngrp = uap->gidsetsize) == 0) { 259 *retval = pc->pc_ucred->cr_ngroups; 260 return (0); 261 } 262 if (ngrp < pc->pc_ucred->cr_ngroups) 263 return (EINVAL); 264 ngrp = pc->pc_ucred->cr_ngroups; 265 if ((error = copyout((caddr_t)pc->pc_ucred->cr_groups, 266 (caddr_t)uap->gidset, ngrp * sizeof(gid_t)))) 267 return (error); 268 *retval = ngrp; 269 return (0); 270 } 271 272 #ifndef _SYS_SYSPROTO_H_ 273 struct setsid_args { 274 int dummy; 275 }; 276 #endif 277 278 /* ARGSUSED */ 279 int 280 setsid(p, uap, retval) 281 register struct proc *p; 282 struct setsid_args *uap; 283 int *retval; 284 { 285 286 if (p->p_pgid == p->p_pid || pgfind(p->p_pid)) { 287 return (EPERM); 288 } else { 289 (void)enterpgrp(p, p->p_pid, 1); 290 *retval = p->p_pid; 291 return (0); 292 } 293 } 294 295 /* 296 * set process group (setpgid/old setpgrp) 297 * 298 * caller does setpgid(targpid, targpgid) 299 * 300 * pid must be caller or child of caller (ESRCH) 301 * if a child 302 * pid must be in same session (EPERM) 303 * pid can't have done an exec (EACCES) 304 * if pgid != pid 305 * there must exist some pid in same session having pgid (EPERM) 306 * pid must not be session leader (EPERM) 307 */ 308 #ifndef _SYS_SYSPROTO_H_ 309 struct setpgid_args { 310 int pid; /* target process id */ 311 int pgid; /* target pgrp id */ 312 }; 313 #endif 314 /* ARGSUSED */ 315 int 316 setpgid(curp, uap, retval) 317 struct proc *curp; 318 register struct setpgid_args *uap; 319 int *retval; 320 { 321 register struct proc *targp; /* target process */ 322 register struct pgrp *pgrp; /* target pgrp */ 323 324 if (uap->pgid < 0) 325 return (EINVAL); 326 if (uap->pid != 0 && uap->pid != curp->p_pid) { 327 if ((targp = pfind(uap->pid)) == 0 || !inferior(targp)) 328 return (ESRCH); 329 if (targp->p_pgrp == NULL || targp->p_session != curp->p_session) 330 return (EPERM); 331 if (targp->p_flag & P_EXEC) 332 return (EACCES); 333 } else 334 targp = curp; 335 if (SESS_LEADER(targp)) 336 return (EPERM); 337 if (uap->pgid == 0) 338 uap->pgid = targp->p_pid; 339 else if (uap->pgid != targp->p_pid) 340 if ((pgrp = pgfind(uap->pgid)) == 0 || 341 pgrp->pg_session != curp->p_session) 342 return (EPERM); 343 return (enterpgrp(targp, uap->pgid, 0)); 344 } 345 346 /* 347 * Use the clause in B.4.2.2 that allows setuid/setgid to be 4.2/4.3BSD 348 * compatable. It says that setting the uid/gid to euid/egid is a special 349 * case of "appropriate privilege". Once the rules are expanded out, this 350 * basically means that setuid(nnn) sets all three id's, in all permitted 351 * cases unless _POSIX_SAVED_IDS is enabled. In that case, setuid(getuid()) 352 * does not set the saved id - this is dangerous for traditional BSD 353 * programs. For this reason, we *really* do not want to set 354 * _POSIX_SAVED_IDS and do not want to clear POSIX_APPENDIX_B_4_2_2. 355 */ 356 #define POSIX_APPENDIX_B_4_2_2 357 358 #ifndef _SYS_SYSPROTO_H_ 359 struct setuid_args { 360 uid_t uid; 361 }; 362 #endif 363 /* ARGSUSED */ 364 int 365 setuid(p, uap, retval) 366 struct proc *p; 367 struct setuid_args *uap; 368 int *retval; 369 { 370 register struct pcred *pc = p->p_cred; 371 register uid_t uid; 372 int error; 373 374 /* 375 * See if we have "permission" by POSIX 1003.1 rules. 376 * 377 * Note that setuid(geteuid()) is a special case of 378 * "appropriate privileges" in appendix B.4.2.2. We need 379 * to use this clause to be compatable with traditional BSD 380 * semantics. Basically, it means that "setuid(xx)" sets all 381 * three id's (assuming you have privs). 382 * 383 * Notes on the logic. We do things in three steps. 384 * 1: We determine if the euid is going to change, and do EPERM 385 * right away. We unconditionally change the euid later if this 386 * test is satisfied, simplifying that part of the logic. 387 * 2: We determine if the real and/or saved uid's are going to 388 * change. Determined by compile options. 389 * 3: Change euid last. (after tests in #2 for "appropriate privs") 390 */ 391 uid = uap->uid; 392 if (uid != pc->p_ruid && /* allow setuid(getuid()) */ 393 #ifdef _POSIX_SAVED_IDS 394 uid != pc->p_svuid && /* allow setuid(saved gid) */ 395 #endif 396 #ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */ 397 uid != pc->pc_ucred->cr_uid && /* allow setuid(geteuid()) */ 398 #endif 399 (error = suser(pc->pc_ucred, &p->p_acflag))) 400 return (error); 401 402 #ifdef _POSIX_SAVED_IDS 403 /* 404 * Do we have "appropriate privileges" (are we root or uid == euid) 405 * If so, we are changing the real uid and/or saved uid. 406 */ 407 if ( 408 #ifdef POSIX_APPENDIX_B_4_2_2 /* Use the clause from B.4.2.2 */ 409 uid == pc->pc_ucred->cr_uid || 410 #endif 411 suser(pc->pc_ucred, &p->p_acflag) == 0) /* we are using privs */ 412 #endif 413 { 414 /* 415 * Transfer proc count to new user. 416 */ 417 if (uid != pc->p_ruid) { 418 (void)chgproccnt(pc->p_ruid, -1); 419 (void)chgproccnt(uid, 1); 420 } 421 /* 422 * Set real uid 423 */ 424 if (uid != pc->p_ruid) { 425 p->p_flag |= P_SUGID; 426 pc->p_ruid = uid; 427 } 428 /* 429 * Set saved uid 430 * 431 * XXX always set saved uid even if not _POSIX_SAVED_IDS, as 432 * the security of seteuid() depends on it. B.4.2.2 says it 433 * is important that we should do this. 434 */ 435 if (pc->p_svuid != uid) { 436 p->p_flag |= P_SUGID; 437 pc->p_svuid = uid; 438 } 439 } 440 441 /* 442 * In all permitted cases, we are changing the euid. 443 * Copy credentials so other references do not see our changes. 444 */ 445 if (pc->pc_ucred->cr_uid != uid) { 446 pc->pc_ucred = crcopy(pc->pc_ucred); 447 pc->pc_ucred->cr_uid = uid; 448 p->p_flag |= P_SUGID; 449 } 450 return (0); 451 } 452 453 #ifndef _SYS_SYSPROTO_H_ 454 struct seteuid_args { 455 uid_t euid; 456 }; 457 #endif 458 /* ARGSUSED */ 459 int 460 seteuid(p, uap, retval) 461 struct proc *p; 462 struct seteuid_args *uap; 463 int *retval; 464 { 465 register struct pcred *pc = p->p_cred; 466 register uid_t euid; 467 int error; 468 469 euid = uap->euid; 470 if (euid != pc->p_ruid && /* allow seteuid(getuid()) */ 471 euid != pc->p_svuid && /* allow seteuid(saved uid) */ 472 (error = suser(pc->pc_ucred, &p->p_acflag))) 473 return (error); 474 /* 475 * Everything's okay, do it. Copy credentials so other references do 476 * not see our changes. 477 */ 478 if (pc->pc_ucred->cr_uid != euid) { 479 pc->pc_ucred = crcopy(pc->pc_ucred); 480 pc->pc_ucred->cr_uid = euid; 481 p->p_flag |= P_SUGID; 482 } 483 return (0); 484 } 485 486 #ifndef _SYS_SYSPROTO_H_ 487 struct setgid_args { 488 gid_t gid; 489 }; 490 #endif 491 /* ARGSUSED */ 492 int 493 setgid(p, uap, retval) 494 struct proc *p; 495 struct setgid_args *uap; 496 int *retval; 497 { 498 register struct pcred *pc = p->p_cred; 499 register gid_t gid; 500 int error; 501 502 /* 503 * See if we have "permission" by POSIX 1003.1 rules. 504 * 505 * Note that setgid(getegid()) is a special case of 506 * "appropriate privileges" in appendix B.4.2.2. We need 507 * to use this clause to be compatable with traditional BSD 508 * semantics. Basically, it means that "setgid(xx)" sets all 509 * three id's (assuming you have privs). 510 * 511 * For notes on the logic here, see setuid() above. 512 */ 513 gid = uap->gid; 514 if (gid != pc->p_rgid && /* allow setgid(getgid()) */ 515 #ifdef _POSIX_SAVED_IDS 516 gid != pc->p_svgid && /* allow setgid(saved gid) */ 517 #endif 518 #ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */ 519 gid != pc->pc_ucred->cr_groups[0] && /* allow setgid(getegid()) */ 520 #endif 521 (error = suser(pc->pc_ucred, &p->p_acflag))) 522 return (error); 523 524 #ifdef _POSIX_SAVED_IDS 525 /* 526 * Do we have "appropriate privileges" (are we root or gid == egid) 527 * If so, we are changing the real uid and saved gid. 528 */ 529 if ( 530 #ifdef POSIX_APPENDIX_B_4_2_2 /* use the clause from B.4.2.2 */ 531 gid == pc->pc_ucred->cr_groups[0] || 532 #endif 533 suser(pc->pc_ucred, &p->p_acflag) == 0) /* we are using privs */ 534 #endif 535 { 536 /* 537 * Set real gid 538 */ 539 if (pc->p_rgid != gid) { 540 p->p_flag |= P_SUGID; 541 pc->p_rgid = gid; 542 } 543 /* 544 * Set saved gid 545 * 546 * XXX always set saved gid even if not _POSIX_SAVED_IDS, as 547 * the security of setegid() depends on it. B.4.2.2 says it 548 * is important that we should do this. 549 */ 550 if (pc->p_svgid != gid) { 551 p->p_flag |= P_SUGID; 552 pc->p_svgid = gid; 553 } 554 } 555 /* 556 * In all cases permitted cases, we are changing the egid. 557 * Copy credentials so other references do not see our changes. 558 */ 559 if (pc->pc_ucred->cr_groups[0] != gid) { 560 pc->pc_ucred = crcopy(pc->pc_ucred); 561 pc->pc_ucred->cr_groups[0] = gid; 562 p->p_flag |= P_SUGID; 563 } 564 return (0); 565 } 566 567 #ifndef _SYS_SYSPROTO_H_ 568 struct setegid_args { 569 gid_t egid; 570 }; 571 #endif 572 /* ARGSUSED */ 573 int 574 setegid(p, uap, retval) 575 struct proc *p; 576 struct setegid_args *uap; 577 int *retval; 578 { 579 register struct pcred *pc = p->p_cred; 580 register gid_t egid; 581 int error; 582 583 egid = uap->egid; 584 if (egid != pc->p_rgid && /* allow setegid(getgid()) */ 585 egid != pc->p_svgid && /* allow setegid(saved gid) */ 586 (error = suser(pc->pc_ucred, &p->p_acflag))) 587 return (error); 588 if (pc->pc_ucred->cr_groups[0] != egid) { 589 pc->pc_ucred = crcopy(pc->pc_ucred); 590 pc->pc_ucred->cr_groups[0] = egid; 591 p->p_flag |= P_SUGID; 592 } 593 return (0); 594 } 595 596 #ifndef _SYS_SYSPROTO_H_ 597 struct setgroups_args { 598 u_int gidsetsize; 599 gid_t *gidset; 600 }; 601 #endif 602 /* ARGSUSED */ 603 int 604 setgroups(p, uap, retval) 605 struct proc *p; 606 struct setgroups_args *uap; 607 int *retval; 608 { 609 register struct pcred *pc = p->p_cred; 610 register u_int ngrp; 611 int error; 612 613 if ((error = suser(pc->pc_ucred, &p->p_acflag))) 614 return (error); 615 ngrp = uap->gidsetsize; 616 if (ngrp > NGROUPS) 617 return (EINVAL); 618 /* 619 * XXX A little bit lazy here. We could test if anything has 620 * changed before crcopy() and setting P_SUGID. 621 */ 622 pc->pc_ucred = crcopy(pc->pc_ucred); 623 if (ngrp < 1) { 624 /* 625 * setgroups(0, NULL) is a legitimate way of clearing the 626 * groups vector on non-BSD systems (which generally do not 627 * have the egid in the groups[0]). We risk security holes 628 * when running non-BSD software if we do not do the same. 629 */ 630 pc->pc_ucred->cr_ngroups = 1; 631 } else { 632 if ((error = copyin((caddr_t)uap->gidset, 633 (caddr_t)pc->pc_ucred->cr_groups, ngrp * sizeof(gid_t)))) 634 return (error); 635 pc->pc_ucred->cr_ngroups = ngrp; 636 } 637 p->p_flag |= P_SUGID; 638 return (0); 639 } 640 641 #ifndef _SYS_SYSPROTO_H_ 642 struct setreuid_args { 643 uid_t ruid; 644 uid_t euid; 645 }; 646 #endif 647 /* ARGSUSED */ 648 int 649 setreuid(p, uap, retval) 650 register struct proc *p; 651 struct setreuid_args *uap; 652 int *retval; 653 { 654 register struct pcred *pc = p->p_cred; 655 register uid_t ruid, euid; 656 int error; 657 658 ruid = uap->ruid; 659 euid = uap->euid; 660 if ((ruid != (uid_t)-1 && ruid != pc->p_ruid && ruid != pc->p_svuid || 661 euid != (uid_t)-1 && euid != pc->pc_ucred->cr_uid && 662 euid != pc->p_ruid && euid != pc->p_svuid) && 663 (error = suser(pc->pc_ucred, &p->p_acflag))) 664 return (error); 665 666 if (euid != (uid_t)-1 && pc->pc_ucred->cr_uid != euid) { 667 pc->pc_ucred = crcopy(pc->pc_ucred); 668 pc->pc_ucred->cr_uid = euid; 669 p->p_flag |= P_SUGID; 670 } 671 if (ruid != (uid_t)-1 && pc->p_ruid != ruid) { 672 (void)chgproccnt(pc->p_ruid, -1); 673 (void)chgproccnt(ruid, 1); 674 pc->p_ruid = ruid; 675 p->p_flag |= P_SUGID; 676 } 677 if ((ruid != (uid_t)-1 || pc->pc_ucred->cr_uid != pc->p_ruid) && 678 pc->p_svuid != pc->pc_ucred->cr_uid) { 679 pc->p_svuid = pc->pc_ucred->cr_uid; 680 p->p_flag |= P_SUGID; 681 } 682 return (0); 683 } 684 685 #ifndef _SYS_SYSPROTO_H_ 686 struct setregid_args { 687 gid_t rgid; 688 gid_t egid; 689 }; 690 #endif 691 /* ARGSUSED */ 692 int 693 setregid(p, uap, retval) 694 register struct proc *p; 695 struct setregid_args *uap; 696 int *retval; 697 { 698 register struct pcred *pc = p->p_cred; 699 register gid_t rgid, egid; 700 int error; 701 702 rgid = uap->rgid; 703 egid = uap->egid; 704 if ((rgid != (gid_t)-1 && rgid != pc->p_rgid && rgid != pc->p_svgid || 705 egid != (gid_t)-1 && egid != pc->pc_ucred->cr_groups[0] && 706 egid != pc->p_rgid && egid != pc->p_svgid) && 707 (error = suser(pc->pc_ucred, &p->p_acflag))) 708 return (error); 709 710 if (egid != (gid_t)-1 && pc->pc_ucred->cr_groups[0] != egid) { 711 pc->pc_ucred = crcopy(pc->pc_ucred); 712 pc->pc_ucred->cr_groups[0] = egid; 713 p->p_flag |= P_SUGID; 714 } 715 if (rgid != (gid_t)-1 && pc->p_rgid != rgid) { 716 pc->p_rgid = rgid; 717 p->p_flag |= P_SUGID; 718 } 719 if ((rgid != (gid_t)-1 || pc->pc_ucred->cr_groups[0] != pc->p_rgid) && 720 pc->p_svgid != pc->pc_ucred->cr_groups[0]) { 721 pc->p_svgid = pc->pc_ucred->cr_groups[0]; 722 p->p_flag |= P_SUGID; 723 } 724 return (0); 725 } 726 727 #ifndef _SYS_SYSPROTO_H_ 728 struct issetugid_args { 729 int dummy; 730 }; 731 #endif 732 /* ARGSUSED */ 733 int 734 issetugid(p, uap, retval) 735 register struct proc *p; 736 struct issetugid_args *uap; 737 int *retval; 738 { 739 /* 740 * Note: OpenBSD sets a P_SUGIDEXEC flag set at execve() time, 741 * we use P_SUGID because we consider changing the owners as 742 * "tainting" as well. 743 * This is significant for procs that start as root and "become" 744 * a user without an exec - programs cannot know *everything* 745 * that libc *might* have put in their data segment. 746 */ 747 if (p->p_flag & P_SUGID) 748 return (1); 749 return (0); 750 } 751 752 /* 753 * Check if gid is a member of the group set. 754 */ 755 int 756 groupmember(gid, cred) 757 gid_t gid; 758 register struct ucred *cred; 759 { 760 register gid_t *gp; 761 gid_t *egp; 762 763 egp = &(cred->cr_groups[cred->cr_ngroups]); 764 for (gp = cred->cr_groups; gp < egp; gp++) 765 if (*gp == gid) 766 return (1); 767 return (0); 768 } 769 770 /* 771 * Test whether the specified credentials imply "super-user" 772 * privilege; if so, and we have accounting info, set the flag 773 * indicating use of super-powers. 774 * Returns 0 or error. 775 */ 776 int 777 suser(cred, acflag) 778 struct ucred *cred; 779 u_short *acflag; 780 { 781 if (cred->cr_uid == 0) { 782 if (acflag) 783 *acflag |= ASU; 784 return (0); 785 } 786 return (EPERM); 787 } 788 789 /* 790 * Allocate a zeroed cred structure. 791 */ 792 struct ucred * 793 crget() 794 { 795 register struct ucred *cr; 796 797 MALLOC(cr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK); 798 bzero((caddr_t)cr, sizeof(*cr)); 799 cr->cr_ref = 1; 800 return (cr); 801 } 802 803 /* 804 * Free a cred structure. 805 * Throws away space when ref count gets to 0. 806 */ 807 void 808 crfree(cr) 809 struct ucred *cr; 810 { 811 int s; 812 813 s = splimp(); /* ??? */ 814 if (--cr->cr_ref == 0) 815 FREE((caddr_t)cr, M_CRED); 816 (void) splx(s); 817 } 818 819 /* 820 * Copy cred structure to a new one and free the old one. 821 */ 822 struct ucred * 823 crcopy(cr) 824 struct ucred *cr; 825 { 826 struct ucred *newcr; 827 828 if (cr->cr_ref == 1) 829 return (cr); 830 newcr = crget(); 831 *newcr = *cr; 832 crfree(cr); 833 newcr->cr_ref = 1; 834 return (newcr); 835 } 836 837 /* 838 * Dup cred struct to a new held one. 839 */ 840 struct ucred * 841 crdup(cr) 842 struct ucred *cr; 843 { 844 struct ucred *newcr; 845 846 newcr = crget(); 847 *newcr = *cr; 848 newcr->cr_ref = 1; 849 return (newcr); 850 } 851 852 /* 853 * Get login name, if available. 854 */ 855 #ifndef _SYS_SYSPROTO_H_ 856 struct getlogin_args { 857 char *namebuf; 858 u_int namelen; 859 }; 860 #endif 861 /* ARGSUSED */ 862 int 863 getlogin(p, uap, retval) 864 struct proc *p; 865 struct getlogin_args *uap; 866 int *retval; 867 { 868 869 if (uap->namelen > MAXLOGNAME) 870 uap->namelen = MAXLOGNAME; 871 return (copyout((caddr_t) p->p_pgrp->pg_session->s_login, 872 (caddr_t) uap->namebuf, uap->namelen)); 873 } 874 875 /* 876 * Set login name. 877 */ 878 #ifndef _SYS_SYSPROTO_H_ 879 struct setlogin_args { 880 char *namebuf; 881 }; 882 #endif 883 /* ARGSUSED */ 884 int 885 setlogin(p, uap, retval) 886 struct proc *p; 887 struct setlogin_args *uap; 888 int *retval; 889 { 890 int error; 891 char logintmp[MAXLOGNAME]; 892 893 if ((error = suser(p->p_ucred, &p->p_acflag))) 894 return (error); 895 error = copyinstr((caddr_t) uap->namebuf, (caddr_t) logintmp, 896 sizeof(logintmp), (u_int *)0); 897 if (error == ENAMETOOLONG) 898 error = EINVAL; 899 else if (!error) 900 (void) memcpy(p->p_pgrp->pg_session->s_login, logintmp, 901 sizeof(logintmp)); 902 return (error); 903 } 904