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 1.12 1995/06/15 22:32:03 ache 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/ucred.h> 50 #include <sys/proc.h> 51 #include <sys/timeb.h> 52 #include <sys/times.h> 53 #include <sys/malloc.h> 54 55 struct getpid_args { 56 int dummy; 57 }; 58 59 /* ARGSUSED */ 60 int 61 getpid(p, uap, retval) 62 struct proc *p; 63 struct getpid_args *uap; 64 int *retval; 65 { 66 67 *retval = p->p_pid; 68 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 69 retval[1] = p->p_pptr->p_pid; 70 #endif 71 return (0); 72 } 73 74 struct getppid_args { 75 int dummy; 76 }; 77 /* ARGSUSED */ 78 int 79 getppid(p, uap, retval) 80 struct proc *p; 81 struct getppid_args *uap; 82 int *retval; 83 { 84 85 *retval = p->p_pptr->p_pid; 86 return (0); 87 } 88 89 /* Get process group ID; note that POSIX getpgrp takes no parameter */ 90 struct getpgrp_args { 91 int dummy; 92 }; 93 94 int 95 getpgrp(p, uap, retval) 96 struct proc *p; 97 struct getpgrp_args *uap; 98 int *retval; 99 { 100 101 *retval = p->p_pgrp->pg_id; 102 return (0); 103 } 104 105 struct getuid_args { 106 int dummy; 107 }; 108 109 /* ARGSUSED */ 110 int 111 getuid(p, uap, retval) 112 struct proc *p; 113 struct getuid_args *uap; 114 int *retval; 115 { 116 117 *retval = p->p_cred->p_ruid; 118 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 119 retval[1] = p->p_ucred->cr_uid; 120 #endif 121 return (0); 122 } 123 124 struct geteuid_args { 125 int dummy; 126 }; 127 128 /* ARGSUSED */ 129 int 130 geteuid(p, uap, retval) 131 struct proc *p; 132 struct geteuid_args *uap; 133 int *retval; 134 { 135 136 *retval = p->p_ucred->cr_uid; 137 return (0); 138 } 139 140 struct getgid_args { 141 int dummy; 142 }; 143 144 /* ARGSUSED */ 145 int 146 getgid(p, uap, retval) 147 struct proc *p; 148 struct getgid_args *uap; 149 int *retval; 150 { 151 152 *retval = p->p_cred->p_rgid; 153 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 154 retval[1] = p->p_ucred->cr_groups[0]; 155 #endif 156 return (0); 157 } 158 159 /* 160 * Get effective group ID. The "egid" is groups[0], and could be obtained 161 * via getgroups. This syscall exists because it is somewhat painful to do 162 * correctly in a library function. 163 */ 164 struct getegid_args { 165 int dummy; 166 }; 167 168 /* ARGSUSED */ 169 int 170 getegid(p, uap, retval) 171 struct proc *p; 172 struct getegid_args *uap; 173 int *retval; 174 { 175 176 *retval = p->p_ucred->cr_groups[0]; 177 return (0); 178 } 179 180 struct getgroups_args { 181 u_int gidsetsize; 182 gid_t *gidset; 183 }; 184 int 185 getgroups(p, uap, retval) 186 struct proc *p; 187 register struct getgroups_args *uap; 188 int *retval; 189 { 190 register struct pcred *pc = p->p_cred; 191 register u_int ngrp; 192 int error; 193 194 if ((ngrp = uap->gidsetsize) == 0) { 195 *retval = pc->pc_ucred->cr_ngroups; 196 return (0); 197 } 198 if (ngrp < pc->pc_ucred->cr_ngroups) 199 return (EINVAL); 200 ngrp = pc->pc_ucred->cr_ngroups; 201 if ((error = copyout((caddr_t)pc->pc_ucred->cr_groups, 202 (caddr_t)uap->gidset, ngrp * sizeof(gid_t)))) 203 return (error); 204 *retval = ngrp; 205 return (0); 206 } 207 208 struct getsid_args { 209 int dummy; 210 }; 211 212 /* ARGSUSED */ 213 int 214 setsid(p, uap, retval) 215 register struct proc *p; 216 struct getsid_args *uap; 217 int *retval; 218 { 219 220 if (p->p_pgid == p->p_pid || pgfind(p->p_pid)) { 221 return (EPERM); 222 } else { 223 (void)enterpgrp(p, p->p_pid, 1); 224 *retval = p->p_pid; 225 return (0); 226 } 227 } 228 229 /* 230 * set process group (setpgid/old setpgrp) 231 * 232 * caller does setpgid(targpid, targpgid) 233 * 234 * pid must be caller or child of caller (ESRCH) 235 * if a child 236 * pid must be in same session (EPERM) 237 * pid can't have done an exec (EACCES) 238 * if pgid != pid 239 * there must exist some pid in same session having pgid (EPERM) 240 * pid must not be session leader (EPERM) 241 */ 242 struct setpgid_args { 243 int pid; /* target process id */ 244 int pgid; /* target pgrp id */ 245 }; 246 /* ARGSUSED */ 247 int 248 setpgid(curp, uap, retval) 249 struct proc *curp; 250 register struct setpgid_args *uap; 251 int *retval; 252 { 253 register struct proc *targp; /* target process */ 254 register struct pgrp *pgrp; /* target pgrp */ 255 256 if (uap->pid != 0 && uap->pid != curp->p_pid) { 257 if ((targp = pfind(uap->pid)) == 0 || !inferior(targp)) 258 return (ESRCH); 259 if (targp->p_session != curp->p_session) 260 return (EPERM); 261 if (targp->p_flag & P_EXEC) 262 return (EACCES); 263 } else 264 targp = curp; 265 if (SESS_LEADER(targp)) 266 return (EPERM); 267 if (uap->pgid == 0) 268 uap->pgid = targp->p_pid; 269 else if (uap->pgid != targp->p_pid) 270 if ((pgrp = pgfind(uap->pgid)) == 0 || 271 pgrp->pg_session != curp->p_session) 272 return (EPERM); 273 return (enterpgrp(targp, uap->pgid, 0)); 274 } 275 276 struct setuid_args { 277 uid_t uid; 278 }; 279 /* ARGSUSED */ 280 int 281 setuid(p, uap, retval) 282 struct proc *p; 283 struct setuid_args *uap; 284 int *retval; 285 { 286 register struct pcred *pc = p->p_cred; 287 register uid_t uid; 288 int error; 289 290 uid = uap->uid; 291 if (uid != pc->p_ruid && uid != pc->p_svuid && 292 (error = suser(pc->pc_ucred, &p->p_acflag))) 293 return (error); 294 /* 295 * Everything's okay, do it. 296 * Transfer proc count to new user. 297 * Copy credentials so other references do not see our changes. 298 */ 299 if (pc->pc_ucred->cr_uid == 0 && uid != pc->p_ruid) { 300 (void)chgproccnt(pc->p_ruid, -1); 301 (void)chgproccnt(uid, 1); 302 } 303 pc->pc_ucred = crcopy(pc->pc_ucred); 304 if (pc->pc_ucred->cr_uid == 0) { 305 pc->p_ruid = uid; 306 pc->p_svuid = uid; 307 } 308 pc->pc_ucred->cr_uid = uid; 309 p->p_flag |= P_SUGID; 310 return (0); 311 } 312 313 struct seteuid_args { 314 uid_t euid; 315 }; 316 /* ARGSUSED */ 317 int 318 seteuid(p, uap, retval) 319 struct proc *p; 320 struct seteuid_args *uap; 321 int *retval; 322 { 323 register struct pcred *pc = p->p_cred; 324 register uid_t euid; 325 int error; 326 327 euid = uap->euid; 328 if (euid != pc->p_ruid && euid != pc->p_svuid && 329 (error = suser(pc->pc_ucred, &p->p_acflag))) 330 return (error); 331 /* 332 * Everything's okay, do it. Copy credentials so other references do 333 * not see our changes. 334 */ 335 pc->pc_ucred = crcopy(pc->pc_ucred); 336 pc->pc_ucred->cr_uid = euid; 337 p->p_flag |= P_SUGID; 338 return (0); 339 } 340 341 struct setgid_args { 342 gid_t gid; 343 }; 344 /* ARGSUSED */ 345 int 346 setgid(p, uap, retval) 347 struct proc *p; 348 struct setgid_args *uap; 349 int *retval; 350 { 351 register struct pcred *pc = p->p_cred; 352 register gid_t gid; 353 int error; 354 355 gid = uap->gid; 356 if (gid != pc->p_rgid && gid != pc->p_svgid && 357 (error = suser(pc->pc_ucred, &p->p_acflag))) 358 return (error); 359 pc->pc_ucred = crcopy(pc->pc_ucred); 360 pc->pc_ucred->cr_groups[0] = gid; 361 if (pc->pc_ucred->cr_uid == 0) { 362 pc->p_rgid = gid; 363 pc->p_svgid = gid; 364 } 365 p->p_flag |= P_SUGID; 366 return (0); 367 } 368 369 struct setegid_args { 370 gid_t egid; 371 }; 372 /* ARGSUSED */ 373 int 374 setegid(p, uap, retval) 375 struct proc *p; 376 struct setegid_args *uap; 377 int *retval; 378 { 379 register struct pcred *pc = p->p_cred; 380 register gid_t egid; 381 int error; 382 383 egid = uap->egid; 384 if (egid != pc->p_rgid && egid != pc->p_svgid && 385 (error = suser(pc->pc_ucred, &p->p_acflag))) 386 return (error); 387 pc->pc_ucred = crcopy(pc->pc_ucred); 388 pc->pc_ucred->cr_groups[0] = egid; 389 p->p_flag |= P_SUGID; 390 return (0); 391 } 392 393 struct setgroups_args { 394 u_int gidsetsize; 395 gid_t *gidset; 396 }; 397 /* ARGSUSED */ 398 int 399 setgroups(p, uap, retval) 400 struct proc *p; 401 struct setgroups_args *uap; 402 int *retval; 403 { 404 register struct pcred *pc = p->p_cred; 405 register u_int ngrp; 406 int error; 407 408 if ((error = suser(pc->pc_ucred, &p->p_acflag))) 409 return (error); 410 if ((ngrp = uap->gidsetsize) > NGROUPS) 411 return (EINVAL); 412 pc->pc_ucred = crcopy(pc->pc_ucred); 413 if ((error = copyin((caddr_t)uap->gidset, 414 (caddr_t)pc->pc_ucred->cr_groups, ngrp * sizeof(gid_t)))) 415 return (error); 416 pc->pc_ucred->cr_ngroups = ngrp; 417 p->p_flag |= P_SUGID; 418 return (0); 419 } 420 421 struct setreuid_args { 422 uid_t ruid; 423 uid_t euid; 424 }; 425 /* ARGSUSED */ 426 int 427 setreuid(p, uap, retval) 428 register struct proc *p; 429 struct setreuid_args *uap; 430 int *retval; 431 { 432 register struct pcred *pc = p->p_cred; 433 register uid_t ruid, euid; 434 int error; 435 436 ruid = uap->ruid; 437 euid = uap->euid; 438 if ((ruid != (uid_t)-1 && ruid != pc->p_ruid && ruid != pc->p_svuid || 439 euid != (uid_t)-1 && euid != pc->p_ruid && euid != pc->p_svuid) && 440 (error = suser(pc->pc_ucred, &p->p_acflag))) 441 return (error); 442 443 pc->pc_ucred = crcopy(pc->pc_ucred); 444 if (euid != (uid_t)-1) 445 pc->pc_ucred->cr_uid = euid; 446 if (ruid != (uid_t)-1 && ruid != pc->p_ruid) { 447 (void)chgproccnt(pc->p_ruid, -1); 448 (void)chgproccnt(ruid, 1); 449 pc->p_ruid = ruid; 450 } 451 if (ruid != (uid_t)-1 || pc->pc_ucred->cr_uid != pc->p_ruid) 452 pc->p_svuid = pc->pc_ucred->cr_uid; 453 p->p_flag |= P_SUGID; 454 return (0); 455 } 456 457 struct setregid_args { 458 gid_t rgid; 459 gid_t egid; 460 }; 461 /* ARGSUSED */ 462 int 463 setregid(p, uap, retval) 464 register struct proc *p; 465 struct setregid_args *uap; 466 int *retval; 467 { 468 register struct pcred *pc = p->p_cred; 469 register gid_t rgid, egid; 470 int error; 471 472 rgid = uap->rgid; 473 egid = uap->egid; 474 if ((rgid != (gid_t)-1 && rgid != pc->p_rgid && rgid != pc->p_svgid || 475 egid != (gid_t)-1 && egid != pc->p_rgid && egid != pc->p_svgid) && 476 (error = suser(pc->pc_ucred, &p->p_acflag))) 477 return (error); 478 479 pc->pc_ucred = crcopy(pc->pc_ucred); 480 if (egid != (gid_t)-1) 481 pc->pc_ucred->cr_groups[0] = egid; 482 if (rgid != (gid_t)-1) 483 pc->p_rgid = rgid; 484 if (rgid != (gid_t)-1 || pc->pc_ucred->cr_groups[0] != pc->p_rgid) 485 pc->p_svgid = pc->pc_ucred->cr_groups[0]; 486 p->p_flag |= P_SUGID; 487 return (0); 488 } 489 490 /* 491 * Check if gid is a member of the group set. 492 */ 493 int 494 groupmember(gid, cred) 495 gid_t gid; 496 register struct ucred *cred; 497 { 498 register gid_t *gp; 499 gid_t *egp; 500 501 egp = &(cred->cr_groups[cred->cr_ngroups]); 502 for (gp = cred->cr_groups; gp < egp; gp++) 503 if (*gp == gid) 504 return (1); 505 return (0); 506 } 507 508 /* 509 * Test whether the specified credentials imply "super-user" 510 * privilege; if so, and we have accounting info, set the flag 511 * indicating use of super-powers. 512 * Returns 0 or error. 513 */ 514 int 515 suser(cred, acflag) 516 struct ucred *cred; 517 u_short *acflag; 518 { 519 if (cred->cr_uid == 0) { 520 if (acflag) 521 *acflag |= ASU; 522 return (0); 523 } 524 return (EPERM); 525 } 526 527 /* 528 * Allocate a zeroed cred structure. 529 */ 530 struct ucred * 531 crget() 532 { 533 register struct ucred *cr; 534 535 MALLOC(cr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK); 536 bzero((caddr_t)cr, sizeof(*cr)); 537 cr->cr_ref = 1; 538 return (cr); 539 } 540 541 /* 542 * Free a cred structure. 543 * Throws away space when ref count gets to 0. 544 */ 545 void 546 crfree(cr) 547 struct ucred *cr; 548 { 549 int s; 550 551 s = splimp(); /* ??? */ 552 if (--cr->cr_ref == 0) 553 FREE((caddr_t)cr, M_CRED); 554 (void) splx(s); 555 } 556 557 /* 558 * Copy cred structure to a new one and free the old one. 559 */ 560 struct ucred * 561 crcopy(cr) 562 struct ucred *cr; 563 { 564 struct ucred *newcr; 565 566 if (cr->cr_ref == 1) 567 return (cr); 568 newcr = crget(); 569 *newcr = *cr; 570 crfree(cr); 571 newcr->cr_ref = 1; 572 return (newcr); 573 } 574 575 /* 576 * Dup cred struct to a new held one. 577 */ 578 struct ucred * 579 crdup(cr) 580 struct ucred *cr; 581 { 582 struct ucred *newcr; 583 584 newcr = crget(); 585 *newcr = *cr; 586 newcr->cr_ref = 1; 587 return (newcr); 588 } 589 590 /* 591 * Get login name, if available. 592 */ 593 struct getlogin_args { 594 char *namebuf; 595 u_int namelen; 596 }; 597 /* ARGSUSED */ 598 int 599 getlogin(p, uap, retval) 600 struct proc *p; 601 struct getlogin_args *uap; 602 int *retval; 603 { 604 605 if (uap->namelen > sizeof (p->p_pgrp->pg_session->s_login)) 606 uap->namelen = sizeof (p->p_pgrp->pg_session->s_login); 607 return (copyout((caddr_t) p->p_pgrp->pg_session->s_login, 608 (caddr_t) uap->namebuf, uap->namelen)); 609 } 610 611 /* 612 * Set login name. 613 */ 614 struct setlogin_args { 615 char *namebuf; 616 }; 617 /* ARGSUSED */ 618 int 619 setlogin(p, uap, retval) 620 struct proc *p; 621 struct setlogin_args *uap; 622 int *retval; 623 { 624 int error; 625 626 if ((error = suser(p->p_ucred, &p->p_acflag))) 627 return (error); 628 error = copyinstr((caddr_t) uap->namebuf, 629 (caddr_t) p->p_pgrp->pg_session->s_login, 630 sizeof (p->p_pgrp->pg_session->s_login) - 1, (u_int *)0); 631 if (error == ENAMETOOLONG) 632 error = EINVAL; 633 return (error); 634 } 635