1 /* 2 * Copyright (c) 1982, 1986, 1989, 1990 Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)kern_prot.c 7.18 (Berkeley) 02/06/91 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 "user.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_ppid; 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_ppid; 45 return (0); 46 } 47 48 getpgrp(p, uap, retval) 49 struct proc *p; 50 struct args { 51 int pid; 52 } *uap; 53 int *retval; 54 { 55 56 if (uap->pid != 0 && (p = pfind(uap->pid)) == 0) 57 return (ESRCH); 58 *retval = p->p_pgrp->pg_id; 59 return (0); 60 } 61 62 /* ARGSUSED */ 63 getuid(p, uap, retval) 64 struct proc *p; 65 void *uap; 66 int *retval; 67 { 68 69 *retval = p->p_ruid; 70 #ifdef COMPAT_43 71 retval[1] = u.u_cred->cr_uid; 72 #endif 73 return (0); 74 } 75 76 /* ARGSUSED */ 77 geteuid(p, uap, retval) 78 struct proc *p; 79 void *uap; 80 int *retval; 81 { 82 83 *retval = u.u_cred->cr_uid; 84 return (0); 85 } 86 87 /* ARGSUSED */ 88 getgid(p, uap, retval) 89 struct proc *p; 90 void *uap; 91 int *retval; 92 { 93 94 *retval = p->p_rgid; 95 #ifdef COMPAT_43 96 retval[1] = u.u_cred->cr_groups[0]; 97 #endif 98 return (0); 99 } 100 101 /* 102 * Get effective group ID. The "egid" is groups[0], and could be obtained 103 * via getgroups. This syscall exists because it is somewhat painful to do 104 * correctly in a library function. 105 */ 106 /* ARGSUSED */ 107 getegid(p, uap, retval) 108 struct proc *p; 109 void *uap; 110 int *retval; 111 { 112 *retval = u.u_cred->cr_groups[0]; 113 return (0); 114 } 115 116 getgroups(p, uap, retval) 117 struct proc *p; 118 register struct arg { 119 u_int gidsetsize; 120 int *gidset; /* XXX not yet POSIX */ 121 } *uap; 122 int *retval; 123 { 124 register gid_t *gp; 125 register int *lp; 126 register u_int ngrp; 127 int groups[NGROUPS]; 128 int error; 129 130 if ((ngrp = uap->gidsetsize) == 0) { 131 *retval = u.u_cred->cr_ngroups; 132 return (0); 133 } 134 if (ngrp < u.u_cred->cr_ngroups) 135 return (EINVAL); 136 ngrp = u.u_cred->cr_ngroups; 137 for (gp = u.u_cred->cr_groups, lp = groups; lp < &groups[ngrp]; ) 138 *lp++ = *gp++; 139 if (error = copyout((caddr_t)groups, (caddr_t)uap->gidset, 140 ngrp * sizeof (groups[0]))) 141 return (error); 142 *retval = ngrp; 143 return (0); 144 } 145 146 /* ARGSUSED */ 147 setsid(p, uap, retval) 148 struct proc *p; 149 void *uap; 150 int *retval; 151 { 152 153 if (p->p_pgid == p->p_pid || pgfind(p->p_pid)) { 154 return (EPERM); 155 } else { 156 pgmv(p, p->p_pid, 1); 157 *retval = p->p_pid; 158 return (0); 159 } 160 } 161 162 /* 163 * set process group (setpgrp/setpgid) 164 * 165 * caller does setpgrp(pid, pgid) 166 * 167 * pid must be caller or child of caller (ESRCH) 168 * if a child 169 * pid must be in same session (EPERM) 170 * pid can't have done an exec (EACCES) 171 * if pgid != pid 172 * there must exist some pid in same session having pgid (EPERM) 173 * pid must not be session leader (EPERM) 174 */ 175 /* ARGSUSED */ 176 setpgrp(cp, uap, retval) 177 struct proc *cp; 178 register struct args { 179 int pid; 180 int pgid; 181 } *uap; 182 int *retval; 183 { 184 register struct proc *p; 185 register struct pgrp *pgrp; 186 187 if (uap->pid != 0) { 188 if ((p = pfind(uap->pid)) == 0 || !inferior(p)) 189 return (ESRCH); 190 if (p->p_session != cp->p_session) 191 return (EPERM); 192 if (p->p_flag&SEXEC) 193 return (EACCES); 194 } else 195 p = cp; 196 if (SESS_LEADER(p)) 197 return (EPERM); 198 if (uap->pgid == 0) 199 uap->pgid = p->p_pid; 200 else if (uap->pgid != p->p_pid) 201 if ((pgrp = pgfind(uap->pgid)) == 0 || 202 pgrp->pg_mem == NULL || 203 pgrp->pg_session != cp->p_session) 204 return (EPERM); 205 pgmv(p, uap->pgid, 0); 206 return (0); 207 } 208 209 /* ARGSUSED */ 210 setuid(p, uap, retval) 211 register struct proc *p; 212 struct args { 213 int uid; 214 } *uap; 215 int *retval; 216 { 217 register uid_t uid; 218 int error; 219 220 uid = uap->uid; 221 if (uid != p->p_ruid && (error = suser(u.u_cred, &u.u_acflag))) 222 return (error); 223 /* 224 * Everything's okay, do it. Copy credentials so other references do 225 * not see our changes. 226 */ 227 u.u_cred = crcopy(u.u_cred); 228 u.u_cred->cr_uid = uid; 229 p->p_uid = uid; 230 p->p_ruid = uid; 231 p->p_svuid = uid; 232 return (0); 233 } 234 235 /* ARGSUSED */ 236 seteuid(p, uap, retval) 237 register struct proc *p; 238 struct args { 239 int euid; 240 } *uap; 241 int *retval; 242 { 243 register uid_t euid; 244 int error; 245 246 euid = uap->euid; 247 if (euid != p->p_ruid && euid != p->p_svuid && 248 (error = suser(u.u_cred, &u.u_acflag))) 249 return (error); 250 /* 251 * Everything's okay, do it. Copy credentials so other references do 252 * not see our changes. 253 */ 254 u.u_cred = crcopy(u.u_cred); 255 u.u_cred->cr_uid = euid; 256 p->p_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 gid_t gid; 269 int error; 270 271 gid = uap->gid; 272 if (gid != p->p_rgid && (error = suser(u.u_cred, &u.u_acflag))) 273 return (error); 274 u.u_cred = crcopy(u.u_cred); 275 p->p_rgid = gid; 276 u.u_cred->cr_groups[0] = gid; 277 p->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 gid_t egid; 290 int error; 291 292 egid = uap->egid; 293 if (egid != p->p_rgid && egid != p->p_svgid && 294 (error = suser(u.u_cred, &u.u_acflag))) 295 return (error); 296 u.u_cred = crcopy(u.u_cred); 297 u.u_cred->cr_groups[0] = egid; 298 return (0); 299 } 300 301 #ifdef COMPAT_43 302 /* ARGSUSED */ 303 osetreuid(p, uap, retval) 304 register struct proc *p; 305 struct args { 306 int ruid; 307 int euid; 308 } *uap; 309 int *retval; 310 { 311 register uid_t ruid, euid; 312 int error; 313 314 if (uap->ruid == -1) 315 ruid = p->p_ruid; 316 else 317 ruid = uap->ruid; 318 /* 319 * Allow setting real uid to previous effective, for swapping real and 320 * effective. This should be: 321 * 322 * if (ruid != p->p_ruid && (error = suser(u.u_cred, &u.u_acflag))) 323 */ 324 if (ruid != p->p_ruid && ruid != u.u_cred->cr_uid /* XXX */ && 325 (error = suser(u.u_cred, &u.u_acflag))) 326 return (error); 327 if (uap->euid == -1) 328 euid = u.u_cred->cr_uid; 329 else 330 euid = uap->euid; 331 if (euid != u.u_cred->cr_uid && euid != p->p_ruid && 332 euid != p->p_svuid && (error = suser(u.u_cred, &u.u_acflag))) 333 return (error); 334 /* 335 * Everything's okay, do it. Copy credentials so other references do 336 * not see our changes. 337 */ 338 u.u_cred = crcopy(u.u_cred); 339 u.u_cred->cr_uid = euid; 340 p->p_uid = euid; 341 p->p_ruid = ruid; 342 return (0); 343 } 344 345 /* ARGSUSED */ 346 osetregid(p, uap, retval) 347 struct proc *p; 348 struct args { 349 int rgid; 350 int egid; 351 } *uap; 352 int *retval; 353 { 354 register gid_t rgid, egid; 355 int error; 356 357 if (uap->rgid == -1) 358 rgid = p->p_rgid; 359 else 360 rgid = uap->rgid; 361 /* 362 * Allow setting real gid to previous effective, for swapping real and 363 * effective. This didn't really work correctly in 4.[23], but is 364 * preserved so old stuff doesn't fail. This should be: 365 * 366 * if (rgid != p->p_rgid && (error = suser(u.u_cred, &u.u_acflag))) 367 */ 368 if (rgid != p->p_rgid && rgid != u.u_cred->cr_groups[0] /* XXX */ && 369 (error = suser(u.u_cred, &u.u_acflag))) 370 return (error); 371 if (uap->egid == -1) 372 egid = u.u_cred->cr_groups[0]; 373 else 374 egid = uap->egid; 375 if (egid != u.u_cred->cr_groups[0] && egid != p->p_rgid && 376 egid != p->p_svgid && (error = suser(u.u_cred, &u.u_acflag))) 377 return (error); 378 u.u_cred = crcopy(u.u_cred); 379 p->p_rgid = rgid; 380 u.u_cred->cr_groups[0] = egid; 381 return (0); 382 } 383 #endif 384 385 /* ARGSUSED */ 386 setgroups(p, uap, retval) 387 struct proc *p; 388 struct args { 389 u_int gidsetsize; 390 int *gidset; 391 } *uap; 392 int *retval; 393 { 394 register gid_t *gp; 395 register u_int ngrp; 396 register int *lp; 397 int error, groups[NGROUPS]; 398 399 if (error = suser(u.u_cred, &u.u_acflag)) 400 return (error); 401 if ((ngrp = uap->gidsetsize) > NGROUPS) 402 return (EINVAL); 403 if (error = copyin((caddr_t)uap->gidset, (caddr_t)groups, 404 ngrp * sizeof (groups[0]))) 405 return (error); 406 u.u_cred = crcopy(u.u_cred); 407 u.u_cred->cr_ngroups = ngrp; 408 /* convert from int's to gid_t's */ 409 for (gp = u.u_cred->cr_groups, lp = groups; ngrp--; ) 410 *gp++ = *lp++; 411 return (0); 412 } 413 414 /* 415 * Check if gid is a member of the group set. 416 */ 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 suser(cred, acflag) 438 struct ucred *cred; 439 short *acflag; 440 { 441 if (cred->cr_uid == 0) { 442 if (acflag) 443 *acflag |= ASU; 444 return (0); 445 } 446 return (EPERM); 447 } 448 449 /* 450 * Allocate a zeroed cred structure. 451 */ 452 struct ucred * 453 crget() 454 { 455 register struct ucred *cr; 456 457 MALLOC(cr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK); 458 bzero((caddr_t)cr, sizeof(*cr)); 459 cr->cr_ref = 1; 460 return (cr); 461 } 462 463 /* 464 * Free a cred structure. 465 * Throws away space when ref count gets to 0. 466 */ 467 crfree(cr) 468 struct ucred *cr; 469 { 470 int s = splimp(); 471 472 if (--cr->cr_ref != 0) { 473 (void) splx(s); 474 return; 475 } 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 getlogin(p, uap, retval) 518 struct proc *p; 519 struct args { 520 char *namebuf; 521 u_int namelen; 522 } *uap; 523 int *retval; 524 { 525 526 if (uap->namelen > sizeof (p->p_logname)) 527 uap->namelen = sizeof (p->p_logname); 528 return (copyout((caddr_t)p->p_logname, (caddr_t)uap->namebuf, 529 uap->namelen)); 530 } 531 532 /* 533 * Set login name. 534 */ 535 /* ARGSUSED */ 536 setlogin(p, uap, retval) 537 struct proc *p; 538 struct args { 539 char *namebuf; 540 } *uap; 541 int *retval; 542 { 543 int error; 544 545 if (error = suser(u.u_cred, &u.u_acflag)) 546 return (error); 547 error = copyinstr((caddr_t)uap->namebuf, (caddr_t)p->p_logname, 548 sizeof (p->p_logname) - 1, (u_int *)0); 549 if (error == ENAMETOOLONG) /* name too long */ 550 error = EINVAL; 551 return (error); 552 } 553