kern_prot.c revision 1.33
1 /* $NetBSD: kern_prot.c,v 1.33 1996/02/09 18:59:42 christos 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 8.6 (Berkeley) 1/21/94 41 */ 42 43 /* 44 * System calls related to processes and protection 45 */ 46 47 #include <sys/param.h> 48 #include <sys/acct.h> 49 #include <sys/systm.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 #include <sys/mount.h> 57 #include <sys/syscallargs.h> 58 59 /* ARGSUSED */ 60 int 61 sys_getpid(p, v, retval) 62 struct proc *p; 63 void *v; 64 register_t *retval; 65 { 66 67 *retval = p->p_pid; 68 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) || defined(COMPAT_IBCS2) || \ 69 defined(COMPAT_FREEBSD) 70 retval[1] = p->p_pptr->p_pid; 71 #endif 72 return (0); 73 } 74 75 /* ARGSUSED */ 76 int 77 sys_getppid(p, v, retval) 78 struct proc *p; 79 void *v; 80 register_t *retval; 81 { 82 83 *retval = p->p_pptr->p_pid; 84 return (0); 85 } 86 87 /* Get process group ID; note that POSIX getpgrp takes no parameter */ 88 int 89 sys_getpgrp(p, v, retval) 90 struct proc *p; 91 void *v; 92 register_t *retval; 93 { 94 95 *retval = p->p_pgrp->pg_id; 96 return (0); 97 } 98 99 /* ARGSUSED */ 100 int 101 sys_getuid(p, v, retval) 102 struct proc *p; 103 void *v; 104 register_t *retval; 105 { 106 107 *retval = p->p_cred->p_ruid; 108 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) || defined(COMPAT_IBCS2) || \ 109 defined(COMPAT_FREEBSD) 110 retval[1] = p->p_ucred->cr_uid; 111 #endif 112 return (0); 113 } 114 115 /* ARGSUSED */ 116 int 117 sys_geteuid(p, v, retval) 118 struct proc *p; 119 void *v; 120 register_t *retval; 121 { 122 123 *retval = p->p_ucred->cr_uid; 124 return (0); 125 } 126 127 /* ARGSUSED */ 128 int 129 sys_getgid(p, v, retval) 130 struct proc *p; 131 void *v; 132 register_t *retval; 133 { 134 135 *retval = p->p_cred->p_rgid; 136 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) || defined(COMPAT_FREEBSD) 137 retval[1] = p->p_ucred->cr_gid; 138 #endif 139 return (0); 140 } 141 142 /* 143 * Get effective group ID. The "egid" is groups[0], and could be obtained 144 * via getgroups. This syscall exists because it is somewhat painful to do 145 * correctly in a library function. 146 */ 147 /* ARGSUSED */ 148 int 149 sys_getegid(p, v, retval) 150 struct proc *p; 151 void *v; 152 register_t *retval; 153 { 154 155 *retval = p->p_ucred->cr_gid; 156 return (0); 157 } 158 159 int 160 sys_getgroups(p, v, retval) 161 struct proc *p; 162 void *v; 163 register_t *retval; 164 { 165 register struct sys_getgroups_args /* { 166 syscallarg(u_int) gidsetsize; 167 syscallarg(gid_t *) gidset; 168 } */ *uap = v; 169 register struct pcred *pc = p->p_cred; 170 register u_int ngrp; 171 int error; 172 173 if ((ngrp = SCARG(uap, gidsetsize)) == 0) { 174 *retval = pc->pc_ucred->cr_ngroups; 175 return (0); 176 } 177 if (ngrp < pc->pc_ucred->cr_ngroups) 178 return (EINVAL); 179 ngrp = pc->pc_ucred->cr_ngroups; 180 error = copyout((caddr_t)pc->pc_ucred->cr_groups, 181 (caddr_t)SCARG(uap, gidset), ngrp * sizeof(gid_t)); 182 if (error) 183 return (error); 184 *retval = ngrp; 185 return (0); 186 } 187 188 /* ARGSUSED */ 189 int 190 sys_setsid(p, v, retval) 191 register struct proc *p; 192 void *v; 193 register_t *retval; 194 { 195 196 if (p->p_pgid == p->p_pid || pgfind(p->p_pid)) { 197 return (EPERM); 198 } else { 199 (void)enterpgrp(p, p->p_pid, 1); 200 *retval = p->p_pid; 201 return (0); 202 } 203 } 204 205 /* 206 * set process group (setpgid/old setpgrp) 207 * 208 * caller does setpgid(targpid, targpgid) 209 * 210 * pid must be caller or child of caller (ESRCH) 211 * if a child 212 * pid must be in same session (EPERM) 213 * pid can't have done an exec (EACCES) 214 * if pgid != pid 215 * there must exist some pid in same session having pgid (EPERM) 216 * pid must not be session leader (EPERM) 217 */ 218 /* ARGSUSED */ 219 int 220 sys_setpgid(curp, v, retval) 221 struct proc *curp; 222 void *v; 223 register_t *retval; 224 { 225 register struct sys_setpgid_args /* { 226 syscallarg(int) pid; 227 syscallarg(int) pgid; 228 } */ *uap = v; 229 register struct proc *targp; /* target process */ 230 register struct pgrp *pgrp; /* target pgrp */ 231 232 #ifdef COMPAT_09 233 SCARG(uap, pid) = (short) SCARG(uap, pid); /* XXX */ 234 SCARG(uap, pgid) = (short) SCARG(uap, pgid); /* XXX */ 235 #endif 236 237 if (SCARG(uap, pid) != 0 && SCARG(uap, pid) != curp->p_pid) { 238 if ((targp = pfind(SCARG(uap, pid))) == 0 || !inferior(targp)) 239 return (ESRCH); 240 if (targp->p_session != curp->p_session) 241 return (EPERM); 242 if (targp->p_flag & P_EXEC) 243 return (EACCES); 244 } else 245 targp = curp; 246 if (SESS_LEADER(targp)) 247 return (EPERM); 248 if (SCARG(uap, pgid) == 0) 249 SCARG(uap, pgid) = targp->p_pid; 250 else if (SCARG(uap, pgid) != targp->p_pid) 251 if ((pgrp = pgfind(SCARG(uap, pgid))) == 0 || 252 pgrp->pg_session != curp->p_session) 253 return (EPERM); 254 return (enterpgrp(targp, SCARG(uap, pgid), 0)); 255 } 256 257 /* ARGSUSED */ 258 int 259 sys_setuid(p, v, retval) 260 struct proc *p; 261 void *v; 262 register_t *retval; 263 { 264 struct sys_setuid_args /* { 265 syscallarg(uid_t) uid; 266 } */ *uap = v; 267 register struct pcred *pc = p->p_cred; 268 register uid_t uid; 269 int error; 270 271 #ifdef COMPAT_09 /* XXX */ 272 uid = (u_short)SCARG(uap, uid); 273 #else 274 uid = SCARG(uap, uid); 275 #endif 276 if (uid != pc->p_ruid && 277 (error = suser(pc->pc_ucred, &p->p_acflag))) 278 return (error); 279 /* 280 * Everything's okay, do it. 281 * Transfer proc count to new user. 282 * Copy credentials so other references do not see our changes. 283 */ 284 (void)chgproccnt(pc->p_ruid, -1); 285 (void)chgproccnt(uid, 1); 286 pc->pc_ucred = crcopy(pc->pc_ucred); 287 pc->pc_ucred->cr_uid = uid; 288 pc->p_ruid = uid; 289 pc->p_svuid = uid; 290 p->p_flag |= P_SUGID; 291 return (0); 292 } 293 294 /* ARGSUSED */ 295 int 296 sys_seteuid(p, v, retval) 297 struct proc *p; 298 void *v; 299 register_t *retval; 300 { 301 struct sys_seteuid_args /* { 302 syscallarg(uid_t) euid; 303 } */ *uap = v; 304 register struct pcred *pc = p->p_cred; 305 register uid_t euid; 306 int error; 307 308 #ifdef COMPAT_09 /* XXX */ 309 euid = (u_short)SCARG(uap, euid); 310 #else 311 euid = SCARG(uap, euid); 312 #endif 313 if (euid != pc->p_ruid && euid != pc->p_svuid && 314 (error = suser(pc->pc_ucred, &p->p_acflag))) 315 return (error); 316 /* 317 * Everything's okay, do it. Copy credentials so other references do 318 * not see our changes. 319 */ 320 pc->pc_ucred = crcopy(pc->pc_ucred); 321 pc->pc_ucred->cr_uid = euid; 322 p->p_flag |= P_SUGID; 323 return (0); 324 } 325 326 /* ARGSUSED */ 327 int 328 sys_setgid(p, v, retval) 329 struct proc *p; 330 void *v; 331 register_t *retval; 332 { 333 struct sys_setgid_args /* { 334 syscallarg(gid_t) gid; 335 } */ *uap = v; 336 register struct pcred *pc = p->p_cred; 337 register gid_t gid; 338 int error; 339 340 #ifdef COMPAT_09 /* XXX */ 341 gid = (u_short)SCARG(uap, gid); 342 #else 343 gid = SCARG(uap, gid); 344 #endif 345 if (gid != pc->p_rgid && (error = suser(pc->pc_ucred, &p->p_acflag))) 346 return (error); 347 pc->pc_ucred = crcopy(pc->pc_ucred); 348 pc->pc_ucred->cr_gid = gid; 349 pc->p_rgid = gid; 350 pc->p_svgid = gid; /* ??? */ 351 p->p_flag |= P_SUGID; 352 return (0); 353 } 354 355 /* ARGSUSED */ 356 int 357 sys_setegid(p, v, retval) 358 struct proc *p; 359 void *v; 360 register_t *retval; 361 { 362 struct sys_setegid_args /* { 363 syscallarg(gid_t) egid; 364 } */ *uap = v; 365 register struct pcred *pc = p->p_cred; 366 register gid_t egid; 367 int error; 368 369 #ifdef COMPAT_09 /* XXX */ 370 egid = (u_short)SCARG(uap, egid); 371 #else 372 egid = SCARG(uap, egid); 373 #endif 374 if (egid != pc->p_rgid && egid != pc->p_svgid && 375 (error = suser(pc->pc_ucred, &p->p_acflag))) 376 return (error); 377 pc->pc_ucred = crcopy(pc->pc_ucred); 378 pc->pc_ucred->cr_gid = egid; 379 p->p_flag |= P_SUGID; 380 return (0); 381 } 382 383 /* ARGSUSED */ 384 int 385 sys_setgroups(p, v, retval) 386 struct proc *p; 387 void *v; 388 register_t *retval; 389 { 390 struct sys_setgroups_args /* { 391 syscallarg(u_int) gidsetsize; 392 syscallarg(gid_t *) gidset; 393 } */ *uap = v; 394 register struct pcred *pc = p->p_cred; 395 register u_int ngrp; 396 int error; 397 398 if ((error = suser(pc->pc_ucred, &p->p_acflag)) != 0) 399 return (error); 400 ngrp = SCARG(uap, gidsetsize); 401 if (ngrp > NGROUPS) 402 return (EINVAL); 403 pc->pc_ucred = crcopy(pc->pc_ucred); 404 error = copyin((caddr_t)SCARG(uap, gidset), 405 (caddr_t)pc->pc_ucred->cr_groups, ngrp * sizeof(gid_t)); 406 if (error) 407 return (error); 408 pc->pc_ucred->cr_ngroups = ngrp; 409 p->p_flag |= P_SUGID; 410 return (0); 411 } 412 413 /* 414 * Check if gid is a member of the group set. 415 */ 416 int 417 groupmember(gid, cred) 418 gid_t gid; 419 register struct ucred *cred; 420 { 421 register gid_t *gp; 422 gid_t *egp; 423 424 egp = &(cred->cr_groups[cred->cr_ngroups]); 425 for (gp = cred->cr_groups; gp < egp; gp++) 426 if (*gp == gid) 427 return (1); 428 return (0); 429 } 430 431 /* 432 * Test whether the specified credentials imply "super-user" 433 * privilege; if so, and we have accounting info, set the flag 434 * indicating use of super-powers. 435 * Returns 0 or error. 436 */ 437 int 438 suser(cred, acflag) 439 struct ucred *cred; 440 u_short *acflag; 441 { 442 if (cred->cr_uid == 0) { 443 if (acflag) 444 *acflag |= ASU; 445 return (0); 446 } 447 return (EPERM); 448 } 449 450 /* 451 * Allocate a zeroed cred structure. 452 */ 453 struct ucred * 454 crget() 455 { 456 register struct ucred *cr; 457 458 MALLOC(cr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK); 459 bzero((caddr_t)cr, sizeof(*cr)); 460 cr->cr_ref = 1; 461 return (cr); 462 } 463 464 /* 465 * Free a cred structure. 466 * Throws away space when ref count gets to 0. 467 */ 468 void 469 crfree(cr) 470 struct ucred *cr; 471 { 472 int s; 473 474 s = splimp(); /* ??? */ 475 if (--cr->cr_ref == 0) 476 FREE((caddr_t)cr, M_CRED); 477 (void) splx(s); 478 } 479 480 /* 481 * Copy cred structure to a new one and free the old one. 482 */ 483 struct ucred * 484 crcopy(cr) 485 struct ucred *cr; 486 { 487 struct ucred *newcr; 488 489 if (cr->cr_ref == 1) 490 return (cr); 491 newcr = crget(); 492 *newcr = *cr; 493 crfree(cr); 494 newcr->cr_ref = 1; 495 return (newcr); 496 } 497 498 /* 499 * Dup cred struct to a new held one. 500 */ 501 struct ucred * 502 crdup(cr) 503 struct ucred *cr; 504 { 505 struct ucred *newcr; 506 507 newcr = crget(); 508 *newcr = *cr; 509 newcr->cr_ref = 1; 510 return (newcr); 511 } 512 513 /* 514 * Get login name, if available. 515 */ 516 /* ARGSUSED */ 517 int 518 sys_getlogin(p, v, retval) 519 struct proc *p; 520 void *v; 521 register_t *retval; 522 { 523 struct sys_getlogin_args /* { 524 syscallarg(char *) namebuf; 525 syscallarg(u_int) namelen; 526 } */ *uap = v; 527 528 if (SCARG(uap, namelen) > sizeof (p->p_pgrp->pg_session->s_login)) 529 SCARG(uap, namelen) = sizeof (p->p_pgrp->pg_session->s_login); 530 return (copyout((caddr_t) p->p_pgrp->pg_session->s_login, 531 (caddr_t) SCARG(uap, namebuf), SCARG(uap, namelen))); 532 } 533 534 /* 535 * Set login name. 536 */ 537 /* ARGSUSED */ 538 int 539 sys_setlogin(p, v, retval) 540 struct proc *p; 541 void *v; 542 register_t *retval; 543 { 544 struct sys_setlogin_args /* { 545 syscallarg(char *) namebuf; 546 } */ *uap = v; 547 int error; 548 549 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 550 return (error); 551 error = copyinstr((caddr_t) SCARG(uap, namebuf), 552 (caddr_t) p->p_pgrp->pg_session->s_login, 553 sizeof (p->p_pgrp->pg_session->s_login) - 1, (size_t *)0); 554 if (error == ENAMETOOLONG) 555 error = EINVAL; 556 return (error); 557 } 558
Indexes created Sat Sep 27 22:09:54 GMT 2025