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 1.15 1995/11/11 06:53:08 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/ucred.h> 51 #include <sys/proc.h> 52 #include <sys/timeb.h> 53 #include <sys/times.h> 54 #include <sys/malloc.h> 55 56 #ifndef _SYS_SYSPROTO_H_ 57 struct getpid_args { 58 int dummy; 59 }; 60 #endif 61 62 /* ARGSUSED */ 63 int 64 getpid(p, uap, retval) 65 struct proc *p; 66 struct getpid_args *uap; 67 int *retval; 68 { 69 70 *retval = p->p_pid; 71 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 72 retval[1] = p->p_pptr->p_pid; 73 #endif 74 return (0); 75 } 76 77 #ifndef _SYS_SYSPROTO_H_ 78 struct getppid_args { 79 int dummy; 80 }; 81 #endif 82 /* ARGSUSED */ 83 int 84 getppid(p, uap, retval) 85 struct proc *p; 86 struct getppid_args *uap; 87 int *retval; 88 { 89 90 *retval = p->p_pptr->p_pid; 91 return (0); 92 } 93 94 /* Get process group ID; note that POSIX getpgrp takes no parameter */ 95 #ifndef _SYS_SYSPROTO_H_ 96 struct getpgrp_args { 97 int dummy; 98 }; 99 #endif 100 101 int 102 getpgrp(p, uap, retval) 103 struct proc *p; 104 struct getpgrp_args *uap; 105 int *retval; 106 { 107 108 *retval = p->p_pgrp->pg_id; 109 return (0); 110 } 111 112 #ifndef _SYS_SYSPROTO_H_ 113 struct getuid_args { 114 int dummy; 115 }; 116 #endif 117 118 /* ARGSUSED */ 119 int 120 getuid(p, uap, retval) 121 struct proc *p; 122 struct getuid_args *uap; 123 int *retval; 124 { 125 126 *retval = p->p_cred->p_ruid; 127 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 128 retval[1] = p->p_ucred->cr_uid; 129 #endif 130 return (0); 131 } 132 133 #ifndef _SYS_SYSPROTO_H_ 134 struct geteuid_args { 135 int dummy; 136 }; 137 #endif 138 139 /* ARGSUSED */ 140 int 141 geteuid(p, uap, retval) 142 struct proc *p; 143 struct geteuid_args *uap; 144 int *retval; 145 { 146 147 *retval = p->p_ucred->cr_uid; 148 return (0); 149 } 150 151 #ifndef _SYS_SYSPROTO_H_ 152 struct getgid_args { 153 int dummy; 154 }; 155 #endif 156 157 /* ARGSUSED */ 158 int 159 getgid(p, uap, retval) 160 struct proc *p; 161 struct getgid_args *uap; 162 int *retval; 163 { 164 165 *retval = p->p_cred->p_rgid; 166 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 167 retval[1] = p->p_ucred->cr_groups[0]; 168 #endif 169 return (0); 170 } 171 172 /* 173 * Get effective group ID. The "egid" is groups[0], and could be obtained 174 * via getgroups. This syscall exists because it is somewhat painful to do 175 * correctly in a library function. 176 */ 177 #ifndef _SYS_SYSPROTO_H_ 178 struct getegid_args { 179 int dummy; 180 }; 181 #endif 182 183 /* ARGSUSED */ 184 int 185 getegid(p, uap, retval) 186 struct proc *p; 187 struct getegid_args *uap; 188 int *retval; 189 { 190 191 *retval = p->p_ucred->cr_groups[0]; 192 return (0); 193 } 194 195 #ifndef _SYS_SYSPROTO_H_ 196 struct getgroups_args { 197 u_int gidsetsize; 198 gid_t *gidset; 199 }; 200 #endif 201 int 202 getgroups(p, uap, retval) 203 struct proc *p; 204 register struct getgroups_args *uap; 205 int *retval; 206 { 207 register struct pcred *pc = p->p_cred; 208 register u_int ngrp; 209 int error; 210 211 if ((ngrp = uap->gidsetsize) == 0) { 212 *retval = pc->pc_ucred->cr_ngroups; 213 return (0); 214 } 215 if (ngrp < pc->pc_ucred->cr_ngroups) 216 return (EINVAL); 217 ngrp = pc->pc_ucred->cr_ngroups; 218 if ((error = copyout((caddr_t)pc->pc_ucred->cr_groups, 219 (caddr_t)uap->gidset, ngrp * sizeof(gid_t)))) 220 return (error); 221 *retval = ngrp; 222 return (0); 223 } 224 225 #ifndef _SYS_SYSPROTO_H_ 226 struct setsid_args { 227 int dummy; 228 }; 229 #endif 230 231 /* ARGSUSED */ 232 int 233 setsid(p, uap, retval) 234 register struct proc *p; 235 struct setsid_args *uap; 236 int *retval; 237 { 238 239 if (p->p_pgid == p->p_pid || pgfind(p->p_pid)) { 240 return (EPERM); 241 } else { 242 (void)enterpgrp(p, p->p_pid, 1); 243 *retval = p->p_pid; 244 return (0); 245 } 246 } 247 248 /* 249 * set process group (setpgid/old setpgrp) 250 * 251 * caller does setpgid(targpid, targpgid) 252 * 253 * pid must be caller or child of caller (ESRCH) 254 * if a child 255 * pid must be in same session (EPERM) 256 * pid can't have done an exec (EACCES) 257 * if pgid != pid 258 * there must exist some pid in same session having pgid (EPERM) 259 * pid must not be session leader (EPERM) 260 */ 261 #ifndef _SYS_SYSPROTO_H_ 262 struct setpgid_args { 263 int pid; /* target process id */ 264 int pgid; /* target pgrp id */ 265 }; 266 #endif 267 /* ARGSUSED */ 268 int 269 setpgid(curp, uap, retval) 270 struct proc *curp; 271 register struct setpgid_args *uap; 272 int *retval; 273 { 274 register struct proc *targp; /* target process */ 275 register struct pgrp *pgrp; /* target pgrp */ 276 277 if (uap->pid != 0 && uap->pid != curp->p_pid) { 278 if ((targp = pfind(uap->pid)) == 0 || !inferior(targp)) 279 return (ESRCH); 280 if (targp->p_session != curp->p_session) 281 return (EPERM); 282 if (targp->p_flag & P_EXEC) 283 return (EACCES); 284 } else 285 targp = curp; 286 if (SESS_LEADER(targp)) 287 return (EPERM); 288 if (uap->pgid == 0) 289 uap->pgid = targp->p_pid; 290 else if (uap->pgid != targp->p_pid) 291 if ((pgrp = pgfind(uap->pgid)) == 0 || 292 pgrp->pg_session != curp->p_session) 293 return (EPERM); 294 return (enterpgrp(targp, uap->pgid, 0)); 295 } 296 297 #ifndef _SYS_SYSPROTO_H_ 298 struct setuid_args { 299 uid_t uid; 300 }; 301 #endif 302 /* ARGSUSED */ 303 int 304 setuid(p, uap, retval) 305 struct proc *p; 306 struct setuid_args *uap; 307 int *retval; 308 { 309 register struct pcred *pc = p->p_cred; 310 register uid_t uid; 311 int error; 312 313 uid = uap->uid; 314 if (uid != pc->p_ruid && uid != pc->p_svuid && 315 (error = suser(pc->pc_ucred, &p->p_acflag))) 316 return (error); 317 /* 318 * Everything's okay, do it. 319 * Transfer proc count to new user. 320 * Copy credentials so other references do not see our changes. 321 */ 322 if (pc->pc_ucred->cr_uid == 0 && uid != pc->p_ruid) { 323 (void)chgproccnt(pc->p_ruid, -1); 324 (void)chgproccnt(uid, 1); 325 } 326 pc->pc_ucred = crcopy(pc->pc_ucred); 327 if (pc->pc_ucred->cr_uid == 0) { 328 pc->p_ruid = uid; 329 pc->p_svuid = uid; 330 } 331 pc->pc_ucred->cr_uid = uid; 332 p->p_flag |= P_SUGID; 333 return (0); 334 } 335 336 #ifndef _SYS_SYSPROTO_H_ 337 struct seteuid_args { 338 uid_t euid; 339 }; 340 #endif 341 /* ARGSUSED */ 342 int 343 seteuid(p, uap, retval) 344 struct proc *p; 345 struct seteuid_args *uap; 346 int *retval; 347 { 348 register struct pcred *pc = p->p_cred; 349 register uid_t euid; 350 int error; 351 352 euid = uap->euid; 353 if (euid != pc->p_ruid && euid != pc->p_svuid && 354 (error = suser(pc->pc_ucred, &p->p_acflag))) 355 return (error); 356 /* 357 * Everything's okay, do it. Copy credentials so other references do 358 * not see our changes. 359 */ 360 pc->pc_ucred = crcopy(pc->pc_ucred); 361 pc->pc_ucred->cr_uid = euid; 362 p->p_flag |= P_SUGID; 363 return (0); 364 } 365 366 #ifndef _SYS_SYSPROTO_H_ 367 struct setgid_args { 368 gid_t gid; 369 }; 370 #endif 371 /* ARGSUSED */ 372 int 373 setgid(p, uap, retval) 374 struct proc *p; 375 struct setgid_args *uap; 376 int *retval; 377 { 378 register struct pcred *pc = p->p_cred; 379 register gid_t gid; 380 int error; 381 382 gid = uap->gid; 383 if (gid != pc->p_rgid && gid != pc->p_svgid && 384 (error = suser(pc->pc_ucred, &p->p_acflag))) 385 return (error); 386 pc->pc_ucred = crcopy(pc->pc_ucred); 387 pc->pc_ucred->cr_groups[0] = gid; 388 if (pc->pc_ucred->cr_uid == 0) { 389 pc->p_rgid = gid; 390 pc->p_svgid = gid; 391 } 392 p->p_flag |= P_SUGID; 393 return (0); 394 } 395 396 #ifndef _SYS_SYSPROTO_H_ 397 struct setegid_args { 398 gid_t egid; 399 }; 400 #endif 401 /* ARGSUSED */ 402 int 403 setegid(p, uap, retval) 404 struct proc *p; 405 struct setegid_args *uap; 406 int *retval; 407 { 408 register struct pcred *pc = p->p_cred; 409 register gid_t egid; 410 int error; 411 412 egid = uap->egid; 413 if (egid != pc->p_rgid && egid != pc->p_svgid && 414 (error = suser(pc->pc_ucred, &p->p_acflag))) 415 return (error); 416 pc->pc_ucred = crcopy(pc->pc_ucred); 417 pc->pc_ucred->cr_groups[0] = egid; 418 p->p_flag |= P_SUGID; 419 return (0); 420 } 421 422 #ifndef _SYS_SYSPROTO_H_ 423 struct setgroups_args { 424 u_int gidsetsize; 425 gid_t *gidset; 426 }; 427 #endif 428 /* ARGSUSED */ 429 int 430 setgroups(p, uap, retval) 431 struct proc *p; 432 struct setgroups_args *uap; 433 int *retval; 434 { 435 register struct pcred *pc = p->p_cred; 436 register u_int ngrp; 437 int error; 438 439 if ((error = suser(pc->pc_ucred, &p->p_acflag))) 440 return (error); 441 ngrp = uap->gidsetsize; 442 if (ngrp < 1 || ngrp > NGROUPS) 443 return (EINVAL); 444 pc->pc_ucred = crcopy(pc->pc_ucred); 445 if ((error = copyin((caddr_t)uap->gidset, 446 (caddr_t)pc->pc_ucred->cr_groups, ngrp * sizeof(gid_t)))) 447 return (error); 448 pc->pc_ucred->cr_ngroups = ngrp; 449 p->p_flag |= P_SUGID; 450 return (0); 451 } 452 453 #ifndef _SYS_SYSPROTO_H_ 454 struct setreuid_args { 455 uid_t ruid; 456 uid_t euid; 457 }; 458 #endif 459 /* ARGSUSED */ 460 int 461 setreuid(p, uap, retval) 462 register struct proc *p; 463 struct setreuid_args *uap; 464 int *retval; 465 { 466 register struct pcred *pc = p->p_cred; 467 register uid_t ruid, euid; 468 int error; 469 470 ruid = uap->ruid; 471 euid = uap->euid; 472 if ((ruid != (uid_t)-1 && ruid != pc->p_ruid && ruid != pc->p_svuid || 473 euid != (uid_t)-1 && euid != pc->p_ruid && euid != pc->p_svuid) && 474 (error = suser(pc->pc_ucred, &p->p_acflag))) 475 return (error); 476 477 pc->pc_ucred = crcopy(pc->pc_ucred); 478 if (euid != (uid_t)-1) 479 pc->pc_ucred->cr_uid = euid; 480 if (ruid != (uid_t)-1 && ruid != pc->p_ruid) { 481 (void)chgproccnt(pc->p_ruid, -1); 482 (void)chgproccnt(ruid, 1); 483 pc->p_ruid = ruid; 484 } 485 if (ruid != (uid_t)-1 || pc->pc_ucred->cr_uid != pc->p_ruid) 486 pc->p_svuid = pc->pc_ucred->cr_uid; 487 p->p_flag |= P_SUGID; 488 return (0); 489 } 490 491 #ifndef _SYS_SYSPROTO_H_ 492 struct setregid_args { 493 gid_t rgid; 494 gid_t egid; 495 }; 496 #endif 497 /* ARGSUSED */ 498 int 499 setregid(p, uap, retval) 500 register struct proc *p; 501 struct setregid_args *uap; 502 int *retval; 503 { 504 register struct pcred *pc = p->p_cred; 505 register gid_t rgid, egid; 506 int error; 507 508 rgid = uap->rgid; 509 egid = uap->egid; 510 if ((rgid != (gid_t)-1 && rgid != pc->p_rgid && rgid != pc->p_svgid || 511 egid != (gid_t)-1 && egid != pc->p_rgid && egid != pc->p_svgid) && 512 (error = suser(pc->pc_ucred, &p->p_acflag))) 513 return (error); 514 515 pc->pc_ucred = crcopy(pc->pc_ucred); 516 if (egid != (gid_t)-1) 517 pc->pc_ucred->cr_groups[0] = egid; 518 if (rgid != (gid_t)-1) 519 pc->p_rgid = rgid; 520 if (rgid != (gid_t)-1 || pc->pc_ucred->cr_groups[0] != pc->p_rgid) 521 pc->p_svgid = pc->pc_ucred->cr_groups[0]; 522 p->p_flag |= P_SUGID; 523 return (0); 524 } 525 526 /* 527 * Check if gid is a member of the group set. 528 */ 529 int 530 groupmember(gid, cred) 531 gid_t gid; 532 register struct ucred *cred; 533 { 534 register gid_t *gp; 535 gid_t *egp; 536 537 egp = &(cred->cr_groups[cred->cr_ngroups]); 538 for (gp = cred->cr_groups; gp < egp; gp++) 539 if (*gp == gid) 540 return (1); 541 return (0); 542 } 543 544 /* 545 * Test whether the specified credentials imply "super-user" 546 * privilege; if so, and we have accounting info, set the flag 547 * indicating use of super-powers. 548 * Returns 0 or error. 549 */ 550 int 551 suser(cred, acflag) 552 struct ucred *cred; 553 u_short *acflag; 554 { 555 if (cred->cr_uid == 0) { 556 if (acflag) 557 *acflag |= ASU; 558 return (0); 559 } 560 return (EPERM); 561 } 562 563 /* 564 * Allocate a zeroed cred structure. 565 */ 566 struct ucred * 567 crget() 568 { 569 register struct ucred *cr; 570 571 MALLOC(cr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK); 572 bzero((caddr_t)cr, sizeof(*cr)); 573 cr->cr_ref = 1; 574 return (cr); 575 } 576 577 /* 578 * Free a cred structure. 579 * Throws away space when ref count gets to 0. 580 */ 581 void 582 crfree(cr) 583 struct ucred *cr; 584 { 585 int s; 586 587 s = splimp(); /* ??? */ 588 if (--cr->cr_ref == 0) 589 FREE((caddr_t)cr, M_CRED); 590 (void) splx(s); 591 } 592 593 /* 594 * Copy cred structure to a new one and free the old one. 595 */ 596 struct ucred * 597 crcopy(cr) 598 struct ucred *cr; 599 { 600 struct ucred *newcr; 601 602 if (cr->cr_ref == 1) 603 return (cr); 604 newcr = crget(); 605 *newcr = *cr; 606 crfree(cr); 607 newcr->cr_ref = 1; 608 return (newcr); 609 } 610 611 /* 612 * Dup cred struct to a new held one. 613 */ 614 struct ucred * 615 crdup(cr) 616 struct ucred *cr; 617 { 618 struct ucred *newcr; 619 620 newcr = crget(); 621 *newcr = *cr; 622 newcr->cr_ref = 1; 623 return (newcr); 624 } 625 626 /* 627 * Get login name, if available. 628 */ 629 #ifndef _SYS_SYSPROTO_H_ 630 struct getlogin_args { 631 char *namebuf; 632 u_int namelen; 633 }; 634 #endif 635 /* ARGSUSED */ 636 int 637 getlogin(p, uap, retval) 638 struct proc *p; 639 struct getlogin_args *uap; 640 int *retval; 641 { 642 643 if (uap->namelen > sizeof (p->p_pgrp->pg_session->s_login)) 644 uap->namelen = sizeof (p->p_pgrp->pg_session->s_login); 645 return (copyout((caddr_t) p->p_pgrp->pg_session->s_login, 646 (caddr_t) uap->namebuf, uap->namelen)); 647 } 648 649 /* 650 * Set login name. 651 */ 652 #ifndef _SYS_SYSPROTO_H_ 653 struct setlogin_args { 654 char *namebuf; 655 }; 656 #endif 657 /* ARGSUSED */ 658 int 659 setlogin(p, uap, retval) 660 struct proc *p; 661 struct setlogin_args *uap; 662 int *retval; 663 { 664 int error; 665 666 if ((error = suser(p->p_ucred, &p->p_acflag))) 667 return (error); 668 error = copyinstr((caddr_t) uap->namebuf, 669 (caddr_t) p->p_pgrp->pg_session->s_login, 670 sizeof (p->p_pgrp->pg_session->s_login) - 1, (u_int *)0); 671 if (error == ENAMETOOLONG) 672 error = EINVAL; 673 return (error); 674 } 675