| 1 | /* |
| 2 | * Copyright (c) 1982, 1986, 1989, 1990, 1991 Regents of the University |
| 3 | * of California. All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * 3. All advertising materials mentioning features or use of this software |
| 14 | * must display the following acknowledgement: |
| 15 | * This product includes software developed by the University of |
| 16 | * California, Berkeley and its contributors. |
| 17 | * 4. Neither the name of the University nor the names of its contributors |
| 18 | * may be used to endorse or promote products derived from this software |
| 19 | * without specific prior written permission. |
| 20 | * |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 31 | * SUCH DAMAGE. |
| 32 | * |
| 33 | * @(#)kern_prot.c 7.21 (Berkeley) 5/3/91 |
| 34 | */ |
| 35 | |
| 36 | /* |
| 37 | * System calls related to processes and protection |
| 38 | */ |
| 39 | |
| 40 | #include "param.h" |
| 41 | #include "acct.h" |
| 42 | #include "systm.h" |
| 43 | #include "ucred.h" |
| 44 | #include "proc.h" |
| 45 | #include "timeb.h" |
| 46 | #include "times.h" |
| 47 | #include "malloc.h" |
| 48 | |
| 49 | /* ARGSUSED */ |
| 50 | getpid(p, uap, retval) |
| 51 | struct proc *p; |
| 52 | void *uap; |
| 53 | int *retval; |
| 54 | { |
| 55 | |
| 56 | *retval = p->p_pid; |
| 57 | #ifdef COMPAT_43 |
| 58 | retval[1] = p->p_pptr->p_pid; |
| 59 | #endif |
| 60 | return (0); |
| 61 | } |
| 62 | |
| 63 | /* ARGSUSED */ |
| 64 | getppid(p, uap, retval) |
| 65 | struct proc *p; |
| 66 | void *uap; |
| 67 | int *retval; |
| 68 | { |
| 69 | |
| 70 | *retval = p->p_pptr->p_pid; |
| 71 | return (0); |
| 72 | } |
| 73 | |
| 74 | /* Get process group ID; note that POSIX getpgrp takes no parameter */ |
| 75 | getpgrp(p, uap, retval) |
| 76 | struct proc *p; |
| 77 | void *uap; |
| 78 | int *retval; |
| 79 | { |
| 80 | |
| 81 | *retval = p->p_pgrp->pg_id; |
| 82 | return (0); |
| 83 | } |
| 84 | |
| 85 | /* ARGSUSED */ |
| 86 | getuid(p, uap, retval) |
| 87 | struct proc *p; |
| 88 | void *uap; |
| 89 | int *retval; |
| 90 | { |
| 91 | |
| 92 | *retval = p->p_cred->p_ruid; |
| 93 | #ifdef COMPAT_43 |
| 94 | retval[1] = p->p_ucred->cr_uid; |
| 95 | #endif |
| 96 | return (0); |
| 97 | } |
| 98 | |
| 99 | /* ARGSUSED */ |
| 100 | geteuid(p, uap, retval) |
| 101 | struct proc *p; |
| 102 | void *uap; |
| 103 | int *retval; |
| 104 | { |
| 105 | |
| 106 | *retval = p->p_ucred->cr_uid; |
| 107 | return (0); |
| 108 | } |
| 109 | |
| 110 | /* ARGSUSED */ |
| 111 | getgid(p, uap, retval) |
| 112 | struct proc *p; |
| 113 | void *uap; |
| 114 | int *retval; |
| 115 | { |
| 116 | |
| 117 | *retval = p->p_cred->p_rgid; |
| 118 | #ifdef COMPAT_43 |
| 119 | retval[1] = p->p_ucred->cr_groups[0]; |
| 120 | #endif |
| 121 | return (0); |
| 122 | } |
| 123 | |
| 124 | /* |
| 125 | * Get effective group ID. The "egid" is groups[0], and could be obtained |
| 126 | * via getgroups. This syscall exists because it is somewhat painful to do |
| 127 | * correctly in a library function. |
| 128 | */ |
| 129 | /* ARGSUSED */ |
| 130 | getegid(p, uap, retval) |
| 131 | struct proc *p; |
| 132 | void *uap; |
| 133 | int *retval; |
| 134 | { |
| 135 | |
| 136 | *retval = p->p_ucred->cr_groups[0]; |
| 137 | return (0); |
| 138 | } |
| 139 | |
| 140 | getgroups(p, uap, retval) |
| 141 | struct proc *p; |
| 142 | register struct arg { |
| 143 | u_int gidsetsize; |
| 144 | int *gidset; /* XXX not yet POSIX */ |
| 145 | } *uap; |
| 146 | int *retval; |
| 147 | { |
| 148 | register struct pcred *pc = p->p_cred; |
| 149 | register gid_t *gp; |
| 150 | register int *lp; |
| 151 | register u_int ngrp; |
| 152 | int groups[NGROUPS]; |
| 153 | int error; |
| 154 | |
| 155 | if ((ngrp = uap->gidsetsize) == 0) { |
| 156 | *retval = pc->pc_ucred->cr_ngroups; |
| 157 | return (0); |
| 158 | } |
| 159 | if (ngrp < pc->pc_ucred->cr_ngroups) |
| 160 | return (EINVAL); |
| 161 | ngrp = pc->pc_ucred->cr_ngroups; |
| 162 | for (gp = pc->pc_ucred->cr_groups, lp = groups; lp < &groups[ngrp]; ) |
| 163 | *lp++ = *gp++; |
| 164 | if (error = copyout((caddr_t)groups, (caddr_t)uap->gidset, |
| 165 | ngrp * sizeof (groups[0]))) |
| 166 | return (error); |
| 167 | *retval = ngrp; |
| 168 | return (0); |
| 169 | } |
| 170 | |
| 171 | /* ARGSUSED */ |
| 172 | setsid(p, uap, retval) |
| 173 | register struct proc *p; |
| 174 | void *uap; |
| 175 | int *retval; |
| 176 | { |
| 177 | |
| 178 | if (p->p_pgid == p->p_pid || pgfind(p->p_pid)) { |
| 179 | return (EPERM); |
| 180 | } else { |
| 181 | enterpgrp(p, p->p_pid, 1); |
| 182 | *retval = p->p_pid; |
| 183 | return (0); |
| 184 | } |
| 185 | } |
| 186 | |
| 187 | /* |
| 188 | * set process group (setpgid/old setpgrp) |
| 189 | * |
| 190 | * caller does setpgid(targpid, targpgid) |
| 191 | * |
| 192 | * pid must be caller or child of caller (ESRCH) |
| 193 | * if a child |
| 194 | * pid must be in same session (EPERM) |
| 195 | * pid can't have done an exec (EACCES) |
| 196 | * if pgid != pid |
| 197 | * there must exist some pid in same session having pgid (EPERM) |
| 198 | * pid must not be session leader (EPERM) |
| 199 | */ |
| 200 | /* ARGSUSED */ |
| 201 | setpgid(curp, uap, retval) |
| 202 | struct proc *curp; |
| 203 | register struct args { |
| 204 | int pid; /* target process id */ |
| 205 | int pgid; /* target pgrp id */ |
| 206 | } *uap; |
| 207 | int *retval; |
| 208 | { |
| 209 | register struct proc *targp; /* target process */ |
| 210 | register struct pgrp *pgrp; /* target pgrp */ |
| 211 | |
| 212 | if (uap->pid != 0 && uap->pid != curp->p_pid) { |
| 213 | if ((targp = pfind(uap->pid)) == 0 || !inferior(targp)) |
| 214 | return (ESRCH); |
| 215 | if (targp->p_session != curp->p_session) |
| 216 | return (EPERM); |
| 217 | if (targp->p_flag&SEXEC) |
| 218 | return (EACCES); |
| 219 | } else |
| 220 | targp = curp; |
| 221 | if (SESS_LEADER(targp)) |
| 222 | return (EPERM); |
| 223 | if (uap->pgid == 0) |
| 224 | uap->pgid = targp->p_pid; |
| 225 | else if (uap->pgid != targp->p_pid) |
| 226 | if ((pgrp = pgfind(uap->pgid)) == 0 || |
| 227 | pgrp->pg_session != curp->p_session) |
| 228 | return (EPERM); |
| 229 | enterpgrp(targp, uap->pgid, 0); |
| 230 | return (0); |
| 231 | } |
| 232 | |
| 233 | /* ARGSUSED */ |
| 234 | setuid(p, uap, retval) |
| 235 | struct proc *p; |
| 236 | struct args { |
| 237 | int uid; |
| 238 | } *uap; |
| 239 | int *retval; |
| 240 | { |
| 241 | register struct pcred *pc = p->p_cred; |
| 242 | register uid_t uid; |
| 243 | int error; |
| 244 | |
| 245 | uid = uap->uid; |
| 246 | if (uid != pc->p_ruid && |
| 247 | (error = suser(pc->pc_ucred, &p->p_acflag))) |
| 248 | return (error); |
| 249 | /* |
| 250 | * Everything's okay, do it. Copy credentials so other references do |
| 251 | * not see our changes. |
| 252 | */ |
| 253 | pc->pc_ucred = crcopy(pc->pc_ucred); |
| 254 | pc->pc_ucred->cr_uid = uid; |
| 255 | pc->p_ruid = uid; |
| 256 | pc->p_svuid = uid; |
| 257 | return (0); |
| 258 | } |
| 259 | |
| 260 | /* ARGSUSED */ |
| 261 | seteuid(p, uap, retval) |
| 262 | struct proc *p; |
| 263 | struct args { |
| 264 | int euid; |
| 265 | } *uap; |
| 266 | int *retval; |
| 267 | { |
| 268 | register struct pcred *pc = p->p_cred; |
| 269 | register uid_t euid; |
| 270 | int error; |
| 271 | |
| 272 | euid = uap->euid; |
| 273 | if (euid != pc->p_ruid && euid != pc->p_svuid && |
| 274 | (error = suser(pc->pc_ucred, &p->p_acflag))) |
| 275 | return (error); |
| 276 | /* |
| 277 | * Everything's okay, do it. Copy credentials so other references do |
| 278 | * not see our changes. |
| 279 | */ |
| 280 | pc->pc_ucred = crcopy(pc->pc_ucred); |
| 281 | pc->pc_ucred->cr_uid = euid; |
| 282 | return (0); |
| 283 | } |
| 284 | |
| 285 | /* ARGSUSED */ |
| 286 | setgid(p, uap, retval) |
| 287 | struct proc *p; |
| 288 | struct args { |
| 289 | int gid; |
| 290 | } *uap; |
| 291 | int *retval; |
| 292 | { |
| 293 | register struct pcred *pc = p->p_cred; |
| 294 | register gid_t gid; |
| 295 | int error; |
| 296 | |
| 297 | gid = uap->gid; |
| 298 | if (gid != pc->p_rgid && (error = suser(pc->pc_ucred, &p->p_acflag))) |
| 299 | return (error); |
| 300 | pc->pc_ucred = crcopy(pc->pc_ucred); |
| 301 | pc->pc_ucred->cr_groups[0] = gid; |
| 302 | pc->p_rgid = gid; |
| 303 | pc->p_svgid = gid; /* ??? */ |
| 304 | return (0); |
| 305 | } |
| 306 | |
| 307 | /* ARGSUSED */ |
| 308 | setegid(p, uap, retval) |
| 309 | struct proc *p; |
| 310 | struct args { |
| 311 | int egid; |
| 312 | } *uap; |
| 313 | int *retval; |
| 314 | { |
| 315 | register struct pcred *pc = p->p_cred; |
| 316 | register gid_t egid; |
| 317 | int error; |
| 318 | |
| 319 | egid = uap->egid; |
| 320 | if (egid != pc->p_rgid && egid != pc->p_svgid && |
| 321 | (error = suser(pc->pc_ucred, &p->p_acflag))) |
| 322 | return (error); |
| 323 | pc->pc_ucred = crcopy(pc->pc_ucred); |
| 324 | pc->pc_ucred->cr_groups[0] = egid; |
| 325 | return (0); |
| 326 | } |
| 327 | |
| 328 | #ifdef COMPAT_43 |
| 329 | /* ARGSUSED */ |
| 330 | osetreuid(p, uap, retval) |
| 331 | register struct proc *p; |
| 332 | struct args { |
| 333 | int ruid; |
| 334 | int euid; |
| 335 | } *uap; |
| 336 | int *retval; |
| 337 | { |
| 338 | register struct pcred *pc = p->p_cred; |
| 339 | register uid_t ruid, euid; |
| 340 | int error; |
| 341 | |
| 342 | if (uap->ruid == -1) |
| 343 | ruid = pc->p_ruid; |
| 344 | else |
| 345 | ruid = uap->ruid; |
| 346 | /* |
| 347 | * Allow setting real uid to previous effective, for swapping real and |
| 348 | * effective. This should be: |
| 349 | * |
| 350 | * if (ruid != pc->p_ruid && |
| 351 | * (error = suser(pc->pc_ucred, &p->p_acflag))) |
| 352 | */ |
| 353 | if (ruid != pc->p_ruid && ruid != pc->pc_ucred->cr_uid /* XXX */ && |
| 354 | (error = suser(pc->pc_ucred, &p->p_acflag))) |
| 355 | return (error); |
| 356 | if (uap->euid == -1) |
| 357 | euid = pc->pc_ucred->cr_uid; |
| 358 | else |
| 359 | euid = uap->euid; |
| 360 | if (euid != pc->pc_ucred->cr_uid && euid != pc->p_ruid && |
| 361 | euid != pc->p_svuid && (error = suser(pc->pc_ucred, &p->p_acflag))) |
| 362 | return (error); |
| 363 | /* |
| 364 | * Everything's okay, do it. Copy credentials so other references do |
| 365 | * not see our changes. |
| 366 | */ |
| 367 | pc->pc_ucred = crcopy(pc->pc_ucred); |
| 368 | pc->pc_ucred->cr_uid = euid; |
| 369 | pc->p_ruid = ruid; |
| 370 | return (0); |
| 371 | } |
| 372 | |
| 373 | /* ARGSUSED */ |
| 374 | osetregid(p, uap, retval) |
| 375 | register struct proc *p; |
| 376 | struct args { |
| 377 | int rgid; |
| 378 | int egid; |
| 379 | } *uap; |
| 380 | int *retval; |
| 381 | { |
| 382 | register struct pcred *pc = p->p_cred; |
| 383 | register gid_t rgid, egid; |
| 384 | int error; |
| 385 | |
| 386 | if (uap->rgid == -1) |
| 387 | rgid = pc->p_rgid; |
| 388 | else |
| 389 | rgid = uap->rgid; |
| 390 | /* |
| 391 | * Allow setting real gid to previous effective, for swapping real and |
| 392 | * effective. This didn't really work correctly in 4.[23], but is |
| 393 | * preserved so old stuff doesn't fail. This should be: |
| 394 | * |
| 395 | * if (rgid != pc->p_rgid && |
| 396 | * (error = suser(pc->pc_ucred, &p->p_acflag))) |
| 397 | */ |
| 398 | if (rgid != pc->p_rgid && rgid != pc->pc_ucred->cr_groups[0] /* XXX */ && |
| 399 | (error = suser(pc->pc_ucred, &p->p_acflag))) |
| 400 | return (error); |
| 401 | if (uap->egid == -1) |
| 402 | egid = pc->pc_ucred->cr_groups[0]; |
| 403 | else |
| 404 | egid = uap->egid; |
| 405 | if (egid != pc->pc_ucred->cr_groups[0] && egid != pc->p_rgid && |
| 406 | egid != pc->p_svgid && (error = suser(pc->pc_ucred, &p->p_acflag))) |
| 407 | return (error); |
| 408 | pc->pc_ucred = crcopy(pc->pc_ucred); |
| 409 | pc->pc_ucred->cr_groups[0] = egid; |
| 410 | pc->p_rgid = rgid; |
| 411 | return (0); |
| 412 | } |
| 413 | #endif |
| 414 | |
| 415 | /* ARGSUSED */ |
| 416 | setgroups(p, uap, retval) |
| 417 | struct proc *p; |
| 418 | struct args { |
| 419 | u_int gidsetsize; |
| 420 | int *gidset; |
| 421 | } *uap; |
| 422 | int *retval; |
| 423 | { |
| 424 | register struct pcred *pc = p->p_cred; |
| 425 | register gid_t *gp; |
| 426 | register u_int ngrp; |
| 427 | register int *lp; |
| 428 | int error, groups[NGROUPS]; |
| 429 | |
| 430 | if (error = suser(pc->pc_ucred, &p->p_acflag)) |
| 431 | return (error); |
| 432 | if ((ngrp = uap->gidsetsize) > NGROUPS) |
| 433 | return (EINVAL); |
| 434 | if (error = copyin((caddr_t)uap->gidset, (caddr_t)groups, |
| 435 | ngrp * sizeof (groups[0]))) |
| 436 | return (error); |
| 437 | pc->pc_ucred = crcopy(pc->pc_ucred); |
| 438 | pc->pc_ucred->cr_ngroups = ngrp; |
| 439 | /* convert from int's to gid_t's */ |
| 440 | for (gp = pc->pc_ucred->cr_groups, lp = groups; ngrp--; ) |
| 441 | *gp++ = *lp++; |
| 442 | return (0); |
| 443 | } |
| 444 | |
| 445 | /* |
| 446 | * Check if gid is a member of the group set. |
| 447 | */ |
| 448 | groupmember(gid, cred) |
| 449 | gid_t gid; |
| 450 | register struct ucred *cred; |
| 451 | { |
| 452 | register gid_t *gp; |
| 453 | gid_t *egp; |
| 454 | |
| 455 | egp = &(cred->cr_groups[cred->cr_ngroups]); |
| 456 | for (gp = cred->cr_groups; gp < egp; gp++) |
| 457 | if (*gp == gid) |
| 458 | return (1); |
| 459 | return (0); |
| 460 | } |
| 461 | |
| 462 | /* |
| 463 | * Test whether the specified credentials imply "super-user" |
| 464 | * privilege; if so, and we have accounting info, set the flag |
| 465 | * indicating use of super-powers. |
| 466 | * Returns 0 or error. |
| 467 | */ |
| 468 | suser(cred, acflag) |
| 469 | struct ucred *cred; |
| 470 | u_short *acflag; |
| 471 | { |
| 472 | if (cred->cr_uid == 0) { |
| 473 | if (acflag) |
| 474 | *acflag |= ASU; |
| 475 | return (0); |
| 476 | } |
| 477 | return (EPERM); |
| 478 | } |
| 479 | |
| 480 | /* |
| 481 | * Allocate a zeroed cred structure. |
| 482 | */ |
| 483 | struct ucred * |
| 484 | crget() |
| 485 | { |
| 486 | register struct ucred *cr; |
| 487 | |
| 488 | MALLOC(cr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK); |
| 489 | bzero((caddr_t)cr, sizeof(*cr)); |
| 490 | cr->cr_ref = 1; |
| 491 | return (cr); |
| 492 | } |
| 493 | |
| 494 | /* |
| 495 | * Free a cred structure. |
| 496 | * Throws away space when ref count gets to 0. |
| 497 | */ |
| 498 | crfree(cr) |
| 499 | struct ucred *cr; |
| 500 | { |
| 501 | int s = splimp(); /* ??? */ |
| 502 | |
| 503 | if (--cr->cr_ref != 0) { |
| 504 | (void) splx(s); |
| 505 | return; |
| 506 | } |
| 507 | FREE((caddr_t)cr, M_CRED); |
| 508 | (void) splx(s); |
| 509 | } |
| 510 | |
| 511 | /* |
| 512 | * Copy cred structure to a new one and free the old one. |
| 513 | */ |
| 514 | struct ucred * |
| 515 | crcopy(cr) |
| 516 | struct ucred *cr; |
| 517 | { |
| 518 | struct ucred *newcr; |
| 519 | |
| 520 | if (cr->cr_ref == 1) |
| 521 | return (cr); |
| 522 | newcr = crget(); |
| 523 | *newcr = *cr; |
| 524 | crfree(cr); |
| 525 | newcr->cr_ref = 1; |
| 526 | return (newcr); |
| 527 | } |
| 528 | |
| 529 | /* |
| 530 | * Dup cred struct to a new held one. |
| 531 | */ |
| 532 | struct ucred * |
| 533 | crdup(cr) |
| 534 | struct ucred *cr; |
| 535 | { |
| 536 | struct ucred *newcr; |
| 537 | |
| 538 | newcr = crget(); |
| 539 | *newcr = *cr; |
| 540 | newcr->cr_ref = 1; |
| 541 | return (newcr); |
| 542 | } |
| 543 | |
| 544 | /* |
| 545 | * Get login name, if available. |
| 546 | */ |
| 547 | /* ARGSUSED */ |
| 548 | getlogin(p, uap, retval) |
| 549 | struct proc *p; |
| 550 | struct args { |
| 551 | char *namebuf; |
| 552 | u_int namelen; |
| 553 | } *uap; |
| 554 | int *retval; |
| 555 | { |
| 556 | |
| 557 | if (uap->namelen > sizeof (p->p_pgrp->pg_session->s_login)) |
| 558 | uap->namelen = sizeof (p->p_pgrp->pg_session->s_login); |
| 559 | return (copyout((caddr_t) p->p_pgrp->pg_session->s_login, |
| 560 | (caddr_t) uap->namebuf, uap->namelen)); |
| 561 | } |
| 562 | |
| 563 | /* |
| 564 | * Set login name. |
| 565 | */ |
| 566 | /* ARGSUSED */ |
| 567 | setlogin(p, uap, retval) |
| 568 | struct proc *p; |
| 569 | struct args { |
| 570 | char *namebuf; |
| 571 | } *uap; |
| 572 | int *retval; |
| 573 | { |
| 574 | int error; |
| 575 | |
| 576 | if (error = suser(p->p_ucred, &p->p_acflag)) |
| 577 | return (error); |
| 578 | error = copyinstr((caddr_t) uap->namebuf, |
| 579 | (caddr_t) p->p_pgrp->pg_session->s_login, |
| 580 | sizeof (p->p_pgrp->pg_session->s_login) - 1, (u_int *)0); |
| 581 | if (error == ENAMETOOLONG) |
| 582 | error = EINVAL; |
| 583 | return (error); |
| 584 | } |