1 /* 2 * Copyright (c) 1982, 1986, 1989, 1990, 1991 Regents of the University 3 * of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)kern_prot.c 7.21 (Berkeley) 05/03/91 8 */ 9 10 /* 11 * System calls related to processes and protection 12 */ 13 14 #include "param.h" 15 #include "acct.h" 16 #include "systm.h" 17 #include "ucred.h" 18 #include "proc.h" 19 #include "timeb.h" 20 #include "times.h" 21 #include "malloc.h" 22 23 /* ARGSUSED */ 24 getpid(p, uap, retval) 25 struct proc *p; 26 void *uap; 27 int *retval; 28 { 29 30 *retval = p->p_pid; 31 #ifdef COMPAT_43 32 retval[1] = p->p_pptr->p_pid; 33 #endif 34 return (0); 35 } 36 37 /* ARGSUSED */ 38 getppid(p, uap, retval) 39 struct proc *p; 40 void *uap; 41 int *retval; 42 { 43 44 *retval = p->p_pptr->p_pid; 45 return (0); 46 } 47 48 /* Get process group ID; note that POSIX getpgrp takes no parameter */ 49 getpgrp(p, uap, retval) 50 struct proc *p; 51 void *uap; 52 int *retval; 53 { 54 55 *retval = p->p_pgrp->pg_id; 56 return (0); 57 } 58 59 /* ARGSUSED */ 60 getuid(p, uap, retval) 61 struct proc *p; 62 void *uap; 63 int *retval; 64 { 65 66 *retval = p->p_cred->p_ruid; 67 #ifdef COMPAT_43 68 retval[1] = p->p_ucred->cr_uid; 69 #endif 70 return (0); 71 } 72 73 /* ARGSUSED */ 74 geteuid(p, uap, retval) 75 struct proc *p; 76 void *uap; 77 int *retval; 78 { 79 80 *retval = p->p_ucred->cr_uid; 81 return (0); 82 } 83 84 /* ARGSUSED */ 85 getgid(p, uap, retval) 86 struct proc *p; 87 void *uap; 88 int *retval; 89 { 90 91 *retval = p->p_cred->p_rgid; 92 #ifdef COMPAT_43 93 retval[1] = p->p_ucred->cr_groups[0]; 94 #endif 95 return (0); 96 } 97 98 /* 99 * Get effective group ID. The "egid" is groups[0], and could be obtained 100 * via getgroups. This syscall exists because it is somewhat painful to do 101 * correctly in a library function. 102 */ 103 /* ARGSUSED */ 104 getegid(p, uap, retval) 105 struct proc *p; 106 void *uap; 107 int *retval; 108 { 109 110 *retval = p->p_ucred->cr_groups[0]; 111 return (0); 112 } 113 114 getgroups(p, uap, retval) 115 struct proc *p; 116 register struct arg { 117 u_int gidsetsize; 118 int *gidset; /* XXX not yet POSIX */ 119 } *uap; 120 int *retval; 121 { 122 register struct pcred *pc = p->p_cred; 123 register gid_t *gp; 124 register int *lp; 125 register u_int ngrp; 126 int groups[NGROUPS]; 127 int error; 128 129 if ((ngrp = uap->gidsetsize) == 0) { 130 *retval = pc->pc_ucred->cr_ngroups; 131 return (0); 132 } 133 if (ngrp < pc->pc_ucred->cr_ngroups) 134 return (EINVAL); 135 ngrp = pc->pc_ucred->cr_ngroups; 136 for (gp = pc->pc_ucred->cr_groups, lp = groups; lp < &groups[ngrp]; ) 137 *lp++ = *gp++; 138 if (error = copyout((caddr_t)groups, (caddr_t)uap->gidset, 139 ngrp * sizeof (groups[0]))) 140 return (error); 141 *retval = ngrp; 142 return (0); 143 } 144 145 /* ARGSUSED */ 146 setsid(p, uap, retval) 147 register struct proc *p; 148 void *uap; 149 int *retval; 150 { 151 152 if (p->p_pgid == p->p_pid || pgfind(p->p_pid)) { 153 return (EPERM); 154 } else { 155 enterpgrp(p, p->p_pid, 1); 156 *retval = p->p_pid; 157 return (0); 158 } 159 } 160 161 /* 162 * set process group (setpgid/old setpgrp) 163 * 164 * caller does setpgid(targpid, targpgid) 165 * 166 * pid must be caller or child of caller (ESRCH) 167 * if a child 168 * pid must be in same session (EPERM) 169 * pid can't have done an exec (EACCES) 170 * if pgid != pid 171 * there must exist some pid in same session having pgid (EPERM) 172 * pid must not be session leader (EPERM) 173 */ 174 /* ARGSUSED */ 175 setpgid(curp, uap, retval) 176 struct proc *curp; 177 register struct args { 178 int pid; /* target process id */ 179 int pgid; /* target pgrp id */ 180 } *uap; 181 int *retval; 182 { 183 register struct proc *targp; /* target process */ 184 register struct pgrp *pgrp; /* target pgrp */ 185 186 if (uap->pid != 0 && uap->pid != curp->p_pid) { 187 if ((targp = pfind(uap->pid)) == 0 || !inferior(targp)) 188 return (ESRCH); 189 if (targp->p_session != curp->p_session) 190 return (EPERM); 191 if (targp->p_flag&SEXEC) 192 return (EACCES); 193 } else 194 targp = curp; 195 if (SESS_LEADER(targp)) 196 return (EPERM); 197 if (uap->pgid == 0) 198 uap->pgid = targp->p_pid; 199 else if (uap->pgid != targp->p_pid) 200 if ((pgrp = pgfind(uap->pgid)) == 0 || 201 pgrp->pg_session != curp->p_session) 202 return (EPERM); 203 enterpgrp(targp, uap->pgid, 0); 204 return (0); 205 } 206 207 /* ARGSUSED */ 208 setuid(p, uap, retval) 209 struct proc *p; 210 struct args { 211 int uid; 212 } *uap; 213 int *retval; 214 { 215 register struct pcred *pc = p->p_cred; 216 register uid_t uid; 217 int error; 218 219 uid = uap->uid; 220 if (uid != pc->p_ruid && 221 (error = suser(pc->pc_ucred, &p->p_acflag))) 222 return (error); 223 /* 224 * Everything's okay, do it. Copy credentials so other references do 225 * not see our changes. 226 */ 227 pc->pc_ucred = crcopy(pc->pc_ucred); 228 pc->pc_ucred->cr_uid = uid; 229 pc->p_ruid = uid; 230 pc->p_svuid = uid; 231 return (0); 232 } 233 234 /* ARGSUSED */ 235 seteuid(p, uap, retval) 236 struct proc *p; 237 struct args { 238 int euid; 239 } *uap; 240 int *retval; 241 { 242 register struct pcred *pc = p->p_cred; 243 register uid_t euid; 244 int error; 245 246 euid = uap->euid; 247 if (euid != pc->p_ruid && euid != pc->p_svuid && 248 (error = suser(pc->pc_ucred, &p->p_acflag))) 249 return (error); 250 /* 251 * Everything's okay, do it. Copy credentials so other references do 252 * not see our changes. 253 */ 254 pc->pc_ucred = crcopy(pc->pc_ucred); 255 pc->pc_ucred->cr_uid = euid; 256 return (0); 257 } 258 259 /* ARGSUSED */ 260 setgid(p, uap, retval) 261 struct proc *p; 262 struct args { 263 int gid; 264 } *uap; 265 int *retval; 266 { 267 register struct pcred *pc = p->p_cred; 268 register gid_t gid; 269 int error; 270 271 gid = uap->gid; 272 if (gid != pc->p_rgid && (error = suser(pc->pc_ucred, &p->p_acflag))) 273 return (error); 274 pc->pc_ucred = crcopy(pc->pc_ucred); 275 pc->pc_ucred->cr_groups[0] = gid; 276 pc->p_rgid = gid; 277 pc->p_svgid = gid; /* ??? */ 278 return (0); 279 } 280 281 /* ARGSUSED */ 282 setegid(p, uap, retval) 283 struct proc *p; 284 struct args { 285 int egid; 286 } *uap; 287 int *retval; 288 { 289 register struct pcred *pc = p->p_cred; 290 register gid_t egid; 291 int error; 292 293 egid = uap->egid; 294 if (egid != pc->p_rgid && egid != pc->p_svgid && 295 (error = suser(pc->pc_ucred, &p->p_acflag))) 296 return (error); 297 pc->pc_ucred = crcopy(pc->pc_ucred); 298 pc->pc_ucred->cr_groups[0] = egid; 299 return (0); 300 } 301 302 #ifdef COMPAT_43 303 /* ARGSUSED */ 304 osetreuid(p, uap, retval) 305 register struct proc *p; 306 struct args { 307 int ruid; 308 int euid; 309 } *uap; 310 int *retval; 311 { 312 register struct pcred *pc = p->p_cred; 313 register uid_t ruid, euid; 314 int error; 315 316 if (uap->ruid == -1) 317 ruid = pc->p_ruid; 318 else 319 ruid = uap->ruid; 320 /* 321 * Allow setting real uid to previous effective, for swapping real and 322 * effective. This should be: 323 * 324 * if (ruid != pc->p_ruid && 325 * (error = suser(pc->pc_ucred, &p->p_acflag))) 326 */ 327 if (ruid != pc->p_ruid && ruid != pc->pc_ucred->cr_uid /* XXX */ && 328 (error = suser(pc->pc_ucred, &p->p_acflag))) 329 return (error); 330 if (uap->euid == -1) 331 euid = pc->pc_ucred->cr_uid; 332 else 333 euid = uap->euid; 334 if (euid != pc->pc_ucred->cr_uid && euid != pc->p_ruid && 335 euid != pc->p_svuid && (error = suser(pc->pc_ucred, &p->p_acflag))) 336 return (error); 337 /* 338 * Everything's okay, do it. Copy credentials so other references do 339 * not see our changes. 340 */ 341 pc->pc_ucred = crcopy(pc->pc_ucred); 342 pc->pc_ucred->cr_uid = euid; 343 pc->p_ruid = ruid; 344 return (0); 345 } 346 347 /* ARGSUSED */ 348 osetregid(p, uap, retval) 349 register struct proc *p; 350 struct args { 351 int rgid; 352 int egid; 353 } *uap; 354 int *retval; 355 { 356 register struct pcred *pc = p->p_cred; 357 register gid_t rgid, egid; 358 int error; 359 360 if (uap->rgid == -1) 361 rgid = pc->p_rgid; 362 else 363 rgid = uap->rgid; 364 /* 365 * Allow setting real gid to previous effective, for swapping real and 366 * effective. This didn't really work correctly in 4.[23], but is 367 * preserved so old stuff doesn't fail. This should be: 368 * 369 * if (rgid != pc->p_rgid && 370 * (error = suser(pc->pc_ucred, &p->p_acflag))) 371 */ 372 if (rgid != pc->p_rgid && rgid != pc->pc_ucred->cr_groups[0] /* XXX */ && 373 (error = suser(pc->pc_ucred, &p->p_acflag))) 374 return (error); 375 if (uap->egid == -1) 376 egid = pc->pc_ucred->cr_groups[0]; 377 else 378 egid = uap->egid; 379 if (egid != pc->pc_ucred->cr_groups[0] && egid != pc->p_rgid && 380 egid != pc->p_svgid && (error = suser(pc->pc_ucred, &p->p_acflag))) 381 return (error); 382 pc->pc_ucred = crcopy(pc->pc_ucred); 383 pc->pc_ucred->cr_groups[0] = egid; 384 pc->p_rgid = rgid; 385 return (0); 386 } 387 #endif 388 389 /* ARGSUSED */ 390 setgroups(p, uap, retval) 391 struct proc *p; 392 struct args { 393 u_int gidsetsize; 394 int *gidset; 395 } *uap; 396 int *retval; 397 { 398 register struct pcred *pc = p->p_cred; 399 register gid_t *gp; 400 register u_int ngrp; 401 register int *lp; 402 int error, groups[NGROUPS]; 403 404 if (error = suser(pc->pc_ucred, &p->p_acflag)) 405 return (error); 406 if ((ngrp = uap->gidsetsize) > NGROUPS) 407 return (EINVAL); 408 if (error = copyin((caddr_t)uap->gidset, (caddr_t)groups, 409 ngrp * sizeof (groups[0]))) 410 return (error); 411 pc->pc_ucred = crcopy(pc->pc_ucred); 412 pc->pc_ucred->cr_ngroups = ngrp; 413 /* convert from int's to gid_t's */ 414 for (gp = pc->pc_ucred->cr_groups, lp = groups; ngrp--; ) 415 *gp++ = *lp++; 416 return (0); 417 } 418 419 /* 420 * Check if gid is a member of the group set. 421 */ 422 groupmember(gid, cred) 423 gid_t gid; 424 register struct ucred *cred; 425 { 426 register gid_t *gp; 427 gid_t *egp; 428 429 egp = &(cred->cr_groups[cred->cr_ngroups]); 430 for (gp = cred->cr_groups; gp < egp; gp++) 431 if (*gp == gid) 432 return (1); 433 return (0); 434 } 435 436 /* 437 * Test whether the specified credentials imply "super-user" 438 * privilege; if so, and we have accounting info, set the flag 439 * indicating use of super-powers. 440 * Returns 0 or error. 441 */ 442 suser(cred, acflag) 443 struct ucred *cred; 444 short *acflag; 445 { 446 if (cred->cr_uid == 0) { 447 if (acflag) 448 *acflag |= ASU; 449 return (0); 450 } 451 return (EPERM); 452 } 453 454 /* 455 * Allocate a zeroed cred structure. 456 */ 457 struct ucred * 458 crget() 459 { 460 register struct ucred *cr; 461 462 MALLOC(cr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK); 463 bzero((caddr_t)cr, sizeof(*cr)); 464 cr->cr_ref = 1; 465 return (cr); 466 } 467 468 /* 469 * Free a cred structure. 470 * Throws away space when ref count gets to 0. 471 */ 472 crfree(cr) 473 struct ucred *cr; 474 { 475 int s = splimp(); /* ??? */ 476 477 if (--cr->cr_ref != 0) { 478 (void) splx(s); 479 return; 480 } 481 FREE((caddr_t)cr, M_CRED); 482 (void) splx(s); 483 } 484 485 /* 486 * Copy cred structure to a new one and free the old one. 487 */ 488 struct ucred * 489 crcopy(cr) 490 struct ucred *cr; 491 { 492 struct ucred *newcr; 493 494 if (cr->cr_ref == 1) 495 return (cr); 496 newcr = crget(); 497 *newcr = *cr; 498 crfree(cr); 499 newcr->cr_ref = 1; 500 return (newcr); 501 } 502 503 /* 504 * Dup cred struct to a new held one. 505 */ 506 struct ucred * 507 crdup(cr) 508 struct ucred *cr; 509 { 510 struct ucred *newcr; 511 512 newcr = crget(); 513 *newcr = *cr; 514 newcr->cr_ref = 1; 515 return (newcr); 516 } 517 518 /* 519 * Get login name, if available. 520 */ 521 /* ARGSUSED */ 522 getlogin(p, uap, retval) 523 struct proc *p; 524 struct args { 525 char *namebuf; 526 u_int namelen; 527 } *uap; 528 int *retval; 529 { 530 531 if (uap->namelen > sizeof (p->p_pgrp->pg_session->s_login)) 532 uap->namelen = sizeof (p->p_pgrp->pg_session->s_login); 533 return (copyout((caddr_t) p->p_pgrp->pg_session->s_login, 534 (caddr_t) uap->namebuf, uap->namelen)); 535 } 536 537 /* 538 * Set login name. 539 */ 540 /* ARGSUSED */ 541 setlogin(p, uap, retval) 542 struct proc *p; 543 struct args { 544 char *namebuf; 545 } *uap; 546 int *retval; 547 { 548 int error; 549 550 if (error = suser(p->p_ucred, &p->p_acflag)) 551 return (error); 552 error = copyinstr((caddr_t) uap->namebuf, 553 (caddr_t) p->p_pgrp->pg_session->s_login, 554 sizeof (p->p_pgrp->pg_session->s_login) - 1, (u_int *)0); 555 if (error == ENAMETOOLONG) 556 error = EINVAL; 557 return (error); 558 } 559