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 7.20 (Berkeley) 04/12/91 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 targpid; /* target process id */ 179 int targpgid; /* target pgrp id */ 180 } *uap; 181 int *retval; 182 { 183 register struct proc *targp; /* target process */ 184 register struct pgrp *targpgrp; /* target pgrp */ 185 186 if (uap->targpid && uap->targpid != curp->p_pid) { 187 if ((targp = pfind(uap->targpid)) == 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->targpgid == 0) 198 uap->targpgid = curp->p_pid; 199 else if (uap->targpgid != curp->p_pid) 200 if ((targpgrp = pgfind(uap->targpgid)) == 0 || 201 targpgrp->pg_mem == NULL || 202 targpgrp->pg_session != curp->p_session) 203 return (EPERM); 204 enterpgrp(targp, uap->targpgid, 0); 205 return (0); 206 } 207 208 /* ARGSUSED */ 209 setuid(p, uap, retval) 210 struct proc *p; 211 struct args { 212 int uid; 213 } *uap; 214 int *retval; 215 { 216 register struct pcred *pc = p->p_cred; 217 register uid_t uid; 218 int error; 219 220 uid = uap->uid; 221 if (uid != pc->p_ruid && 222 (error = suser(pc->pc_ucred, &p->p_acflag))) 223 return (error); 224 /* 225 * Everything's okay, do it. Copy credentials so other references do 226 * not see our changes. 227 */ 228 pc->pc_ucred = crcopy(pc->pc_ucred); 229 pc->pc_ucred->cr_uid = uid; 230 pc->p_ruid = uid; 231 pc->p_svuid = uid; 232 return (0); 233 } 234 235 /* ARGSUSED */ 236 seteuid(p, uap, retval) 237 struct proc *p; 238 struct args { 239 int euid; 240 } *uap; 241 int *retval; 242 { 243 register struct pcred *pc = p->p_cred; 244 register uid_t euid; 245 int error; 246 247 euid = uap->euid; 248 if (euid != pc->p_ruid && euid != pc->p_svuid && 249 (error = suser(pc->pc_ucred, &p->p_acflag))) 250 return (error); 251 /* 252 * Everything's okay, do it. Copy credentials so other references do 253 * not see our changes. 254 */ 255 pc->pc_ucred = crcopy(pc->pc_ucred); 256 pc->pc_ucred->cr_uid = euid; 257 return (0); 258 } 259 260 /* ARGSUSED */ 261 setgid(p, uap, retval) 262 struct proc *p; 263 struct args { 264 int gid; 265 } *uap; 266 int *retval; 267 { 268 register struct pcred *pc = p->p_cred; 269 register gid_t gid; 270 int error; 271 272 gid = uap->gid; 273 if (gid != pc->p_rgid && (error = suser(pc->pc_ucred, &p->p_acflag))) 274 return (error); 275 pc->pc_ucred = crcopy(pc->pc_ucred); 276 pc->pc_ucred->cr_groups[0] = gid; 277 pc->p_rgid = gid; 278 pc->p_svgid = gid; /* ??? */ 279 return (0); 280 } 281 282 /* ARGSUSED */ 283 setegid(p, uap, retval) 284 struct proc *p; 285 struct args { 286 int egid; 287 } *uap; 288 int *retval; 289 { 290 register struct pcred *pc = p->p_cred; 291 register gid_t egid; 292 int error; 293 294 egid = uap->egid; 295 if (egid != pc->p_rgid && egid != pc->p_svgid && 296 (error = suser(pc->pc_ucred, &p->p_acflag))) 297 return (error); 298 pc->pc_ucred = crcopy(pc->pc_ucred); 299 pc->pc_ucred->cr_groups[0] = egid; 300 return (0); 301 } 302 303 #ifdef COMPAT_43 304 /* ARGSUSED */ 305 osetreuid(p, uap, retval) 306 register struct proc *p; 307 struct args { 308 int ruid; 309 int euid; 310 } *uap; 311 int *retval; 312 { 313 register struct pcred *pc = p->p_cred; 314 register uid_t ruid, euid; 315 int error; 316 317 if (uap->ruid == -1) 318 ruid = pc->p_ruid; 319 else 320 ruid = uap->ruid; 321 /* 322 * Allow setting real uid to previous effective, for swapping real and 323 * effective. This should be: 324 * 325 * if (ruid != pc->p_ruid && 326 * (error = suser(pc->pc_ucred, &p->p_acflag))) 327 */ 328 if (ruid != pc->p_ruid && ruid != pc->pc_ucred->cr_uid /* XXX */ && 329 (error = suser(pc->pc_ucred, &p->p_acflag))) 330 return (error); 331 if (uap->euid == -1) 332 euid = pc->pc_ucred->cr_uid; 333 else 334 euid = uap->euid; 335 if (euid != pc->pc_ucred->cr_uid && euid != pc->p_ruid && 336 euid != pc->p_svuid && (error = suser(pc->pc_ucred, &p->p_acflag))) 337 return (error); 338 /* 339 * Everything's okay, do it. Copy credentials so other references do 340 * not see our changes. 341 */ 342 pc->pc_ucred = crcopy(pc->pc_ucred); 343 pc->pc_ucred->cr_uid = euid; 344 pc->p_ruid = ruid; 345 return (0); 346 } 347 348 /* ARGSUSED */ 349 osetregid(p, uap, retval) 350 register struct proc *p; 351 struct args { 352 int rgid; 353 int egid; 354 } *uap; 355 int *retval; 356 { 357 register struct pcred *pc = p->p_cred; 358 register gid_t rgid, egid; 359 int error; 360 361 if (uap->rgid == -1) 362 rgid = pc->p_rgid; 363 else 364 rgid = uap->rgid; 365 /* 366 * Allow setting real gid to previous effective, for swapping real and 367 * effective. This didn't really work correctly in 4.[23], but is 368 * preserved so old stuff doesn't fail. This should be: 369 * 370 * if (rgid != pc->p_rgid && 371 * (error = suser(pc->pc_ucred, &p->p_acflag))) 372 */ 373 if (rgid != pc->p_rgid && rgid != pc->pc_ucred->cr_groups[0] /* XXX */ && 374 (error = suser(pc->pc_ucred, &p->p_acflag))) 375 return (error); 376 if (uap->egid == -1) 377 egid = pc->pc_ucred->cr_groups[0]; 378 else 379 egid = uap->egid; 380 if (egid != pc->pc_ucred->cr_groups[0] && egid != pc->p_rgid && 381 egid != pc->p_svgid && (error = suser(pc->pc_ucred, &p->p_acflag))) 382 return (error); 383 pc->pc_ucred = crcopy(pc->pc_ucred); 384 pc->pc_ucred->cr_groups[0] = egid; 385 pc->p_rgid = rgid; 386 return (0); 387 } 388 #endif 389 390 /* ARGSUSED */ 391 setgroups(p, uap, retval) 392 struct proc *p; 393 struct args { 394 u_int gidsetsize; 395 int *gidset; 396 } *uap; 397 int *retval; 398 { 399 register struct pcred *pc = p->p_cred; 400 register gid_t *gp; 401 register u_int ngrp; 402 register int *lp; 403 int error, groups[NGROUPS]; 404 405 if (error = suser(pc->pc_ucred, &p->p_acflag)) 406 return (error); 407 if ((ngrp = uap->gidsetsize) > NGROUPS) 408 return (EINVAL); 409 if (error = copyin((caddr_t)uap->gidset, (caddr_t)groups, 410 ngrp * sizeof (groups[0]))) 411 return (error); 412 pc->pc_ucred = crcopy(pc->pc_ucred); 413 pc->pc_ucred->cr_ngroups = ngrp; 414 /* convert from int's to gid_t's */ 415 for (gp = pc->pc_ucred->cr_groups, lp = groups; ngrp--; ) 416 *gp++ = *lp++; 417 return (0); 418 } 419 420 /* 421 * Check if gid is a member of the group set. 422 */ 423 groupmember(gid, cred) 424 gid_t gid; 425 register struct ucred *cred; 426 { 427 register gid_t *gp; 428 gid_t *egp; 429 430 egp = &(cred->cr_groups[cred->cr_ngroups]); 431 for (gp = cred->cr_groups; gp < egp; gp++) 432 if (*gp == gid) 433 return (1); 434 return (0); 435 } 436 437 /* 438 * Test whether the specified credentials imply "super-user" 439 * privilege; if so, and we have accounting info, set the flag 440 * indicating use of super-powers. 441 * Returns 0 or error. 442 */ 443 suser(cred, acflag) 444 struct ucred *cred; 445 short *acflag; 446 { 447 if (cred->cr_uid == 0) { 448 if (acflag) 449 *acflag |= ASU; 450 return (0); 451 } 452 return (EPERM); 453 } 454 455 /* 456 * Allocate a zeroed cred structure. 457 */ 458 struct ucred * 459 crget() 460 { 461 register struct ucred *cr; 462 463 MALLOC(cr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK); 464 bzero((caddr_t)cr, sizeof(*cr)); 465 cr->cr_ref = 1; 466 return (cr); 467 } 468 469 /* 470 * Free a cred structure. 471 * Throws away space when ref count gets to 0. 472 */ 473 crfree(cr) 474 struct ucred *cr; 475 { 476 int s = splimp(); /* ??? */ 477 478 if (--cr->cr_ref != 0) { 479 (void) splx(s); 480 return; 481 } 482 FREE((caddr_t)cr, M_CRED); 483 (void) splx(s); 484 } 485 486 /* 487 * Copy cred structure to a new one and free the old one. 488 */ 489 struct ucred * 490 crcopy(cr) 491 struct ucred *cr; 492 { 493 struct ucred *newcr; 494 495 if (cr->cr_ref == 1) 496 return (cr); 497 newcr = crget(); 498 *newcr = *cr; 499 crfree(cr); 500 newcr->cr_ref = 1; 501 return (newcr); 502 } 503 504 /* 505 * Dup cred struct to a new held one. 506 */ 507 struct ucred * 508 crdup(cr) 509 struct ucred *cr; 510 { 511 struct ucred *newcr; 512 513 newcr = crget(); 514 *newcr = *cr; 515 newcr->cr_ref = 1; 516 return (newcr); 517 } 518 519 /* 520 * Get login name, if available. 521 */ 522 /* ARGSUSED */ 523 getlogin(p, uap, retval) 524 struct proc *p; 525 struct args { 526 char *namebuf; 527 u_int namelen; 528 } *uap; 529 int *retval; 530 { 531 532 if (uap->namelen > sizeof (p->p_pgrp->pg_session->s_login)) 533 uap->namelen = sizeof (p->p_pgrp->pg_session->s_login); 534 return (copyout((caddr_t) p->p_pgrp->pg_session->s_login, 535 (caddr_t) uap->namebuf, uap->namelen)); 536 } 537 538 /* 539 * Set login name. 540 */ 541 /* ARGSUSED */ 542 setlogin(p, uap, retval) 543 struct proc *p; 544 struct args { 545 char *namebuf; 546 } *uap; 547 int *retval; 548 { 549 int error; 550 551 if (error = suser(p->p_ucred, &p->p_acflag)) 552 return (error); 553 error = copyinstr((caddr_t) uap->namebuf, 554 (caddr_t) p->p_pgrp->pg_session->s_login, 555 sizeof (p->p_pgrp->pg_session->s_login) - 1, (u_int *)0); 556 if (error == ENAMETOOLONG) 557 error = EINVAL; 558 return (error); 559 } 560