1 /* 2 * Copyright (c) 1993, 1995 Jan-Simon Pendry 3 * Copyright (c) 1993, 1995 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * Jan-Simon Pendry. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)procfs_vnops.c 8.18 (Berkeley) 5/21/95 38 * 39 * $FreeBSD: src/sys/miscfs/procfs/procfs_vnops.c,v 1.76.2.7 2002/01/22 17:22:59 nectar Exp $ 40 * $DragonFly: src/sys/vfs/procfs/procfs_vnops.c,v 1.27 2005/11/20 02:23:59 dillon Exp $ 41 */ 42 43 /* 44 * procfs vnode interface 45 */ 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/time.h> 50 #include <sys/kernel.h> 51 #include <sys/lock.h> 52 #include <sys/fcntl.h> 53 #include <sys/proc.h> 54 #include <sys/signalvar.h> 55 #include <sys/vnode.h> 56 #include <sys/uio.h> 57 #include <sys/mount.h> 58 #include <sys/namei.h> 59 #include <sys/dirent.h> 60 #include <sys/malloc.h> 61 #include <machine/reg.h> 62 #include <vm/vm_zone.h> 63 #include <vfs/procfs/procfs.h> 64 #include <sys/pioctl.h> 65 66 #include <machine/limits.h> 67 68 static int procfs_access (struct vop_access_args *); 69 static int procfs_badop (void); 70 static int procfs_bmap (struct vop_bmap_args *); 71 static int procfs_close (struct vop_close_args *); 72 static int procfs_getattr (struct vop_getattr_args *); 73 static int procfs_inactive (struct vop_inactive_args *); 74 static int procfs_ioctl (struct vop_ioctl_args *); 75 static int procfs_lookup (struct vop_old_lookup_args *); 76 static int procfs_open (struct vop_open_args *); 77 static int procfs_print (struct vop_print_args *); 78 static int procfs_readdir (struct vop_readdir_args *); 79 static int procfs_readlink (struct vop_readlink_args *); 80 static int procfs_reclaim (struct vop_reclaim_args *); 81 static int procfs_setattr (struct vop_setattr_args *); 82 83 static int procfs_readdir_proc(struct vop_readdir_args *); 84 static int procfs_readdir_root(struct vop_readdir_args *); 85 86 /* 87 * This is a list of the valid names in the 88 * process-specific sub-directories. It is 89 * used in procfs_lookup and procfs_readdir 90 */ 91 static struct proc_target { 92 u_char pt_type; 93 u_char pt_namlen; 94 char *pt_name; 95 pfstype pt_pfstype; 96 int (*pt_valid) (struct proc *p); 97 } proc_targets[] = { 98 #define N(s) sizeof(s)-1, s 99 /* name type validp */ 100 { DT_DIR, N("."), Pproc, NULL }, 101 { DT_DIR, N(".."), Proot, NULL }, 102 { DT_REG, N("mem"), Pmem, NULL }, 103 { DT_REG, N("regs"), Pregs, procfs_validregs }, 104 { DT_REG, N("fpregs"), Pfpregs, procfs_validfpregs }, 105 { DT_REG, N("dbregs"), Pdbregs, procfs_validdbregs }, 106 { DT_REG, N("ctl"), Pctl, NULL }, 107 { DT_REG, N("status"), Pstatus, NULL }, 108 { DT_REG, N("note"), Pnote, NULL }, 109 { DT_REG, N("notepg"), Pnotepg, NULL }, 110 { DT_REG, N("map"), Pmap, procfs_validmap }, 111 { DT_REG, N("etype"), Ptype, procfs_validtype }, 112 { DT_REG, N("cmdline"), Pcmdline, NULL }, 113 { DT_REG, N("rlimit"), Prlimit, NULL }, 114 { DT_LNK, N("file"), Pfile, NULL }, 115 #undef N 116 }; 117 static const int nproc_targets = sizeof(proc_targets) / sizeof(proc_targets[0]); 118 119 static pid_t atopid (const char *, u_int); 120 121 /* 122 * set things up for doing i/o on 123 * the pfsnode (vp). (vp) is locked 124 * on entry, and should be left locked 125 * on exit. 126 * 127 * for procfs we don't need to do anything 128 * in particular for i/o. all that is done 129 * is to support exclusive open on process 130 * memory images. 131 * 132 * procfs_open(struct vnode *a_vp, int a_mode, struct ucred *a_cred, 133 * struct thread *a_td) 134 */ 135 static int 136 procfs_open(struct vop_open_args *ap) 137 { 138 struct pfsnode *pfs = VTOPFS(ap->a_vp); 139 struct proc *p1, *p2; 140 141 p2 = PFIND(pfs->pfs_pid); 142 if (p2 == NULL) 143 return (ENOENT); 144 if (pfs->pfs_pid && !PRISON_CHECK(ap->a_cred, p2->p_ucred)) 145 return (ENOENT); 146 147 switch (pfs->pfs_type) { 148 case Pmem: 149 if (((pfs->pfs_flags & FWRITE) && (ap->a_mode & O_EXCL)) || 150 ((pfs->pfs_flags & O_EXCL) && (ap->a_mode & FWRITE))) 151 return (EBUSY); 152 153 p1 = ap->a_td->td_proc; 154 KKASSERT(p1); 155 /* Can't trace a process that's currently exec'ing. */ 156 if ((p2->p_flag & P_INEXEC) != 0) 157 return EAGAIN; 158 if (!CHECKIO(p1, p2) || p_trespass(ap->a_cred, p2->p_ucred)) 159 return (EPERM); 160 161 if (ap->a_mode & FWRITE) 162 pfs->pfs_flags = ap->a_mode & (FWRITE|O_EXCL); 163 164 return (0); 165 166 default: 167 break; 168 } 169 170 return (0); 171 } 172 173 /* 174 * close the pfsnode (vp) after doing i/o. 175 * (vp) is not locked on entry or exit. 176 * 177 * nothing to do for procfs other than undo 178 * any exclusive open flag (see _open above). 179 * 180 * procfs_close(struct vnode *a_vp, int a_fflag, struct ucred *a_cred, 181 * struct thread *a_td) 182 */ 183 static int 184 procfs_close(struct vop_close_args *ap) 185 { 186 struct pfsnode *pfs = VTOPFS(ap->a_vp); 187 struct proc *p; 188 189 switch (pfs->pfs_type) { 190 case Pmem: 191 if ((ap->a_fflag & FWRITE) && (pfs->pfs_flags & O_EXCL)) 192 pfs->pfs_flags &= ~(FWRITE|O_EXCL); 193 /* 194 * This rather complicated-looking code is trying to 195 * determine if this was the last close on this particular 196 * vnode. While one would expect v_usecount to be 1 at 197 * that point, it seems that (according to John Dyson) 198 * the VM system will bump up the usecount. So: if the 199 * usecount is 2, and VOBJBUF is set, then this is really 200 * the last close. Otherwise, if the usecount is < 2 201 * then it is definitely the last close. 202 * If this is the last close, then it checks to see if 203 * the target process has PF_LINGER set in p_pfsflags, 204 * if this is *not* the case, then the process' stop flags 205 * are cleared, and the process is woken up. This is 206 * to help prevent the case where a process has been 207 * told to stop on an event, but then the requesting process 208 * has gone away or forgotten about it. 209 */ 210 if ((ap->a_vp->v_usecount < 2) 211 && (p = pfind(pfs->pfs_pid)) 212 && !(p->p_pfsflags & PF_LINGER)) { 213 p->p_stops = 0; 214 p->p_step = 0; 215 wakeup(&p->p_step); 216 } 217 break; 218 default: 219 break; 220 } 221 222 return (0); 223 } 224 225 /* 226 * do an ioctl operation on a pfsnode (vp). 227 * (vp) is not locked on entry or exit. 228 */ 229 static int 230 procfs_ioctl(struct vop_ioctl_args *ap) 231 { 232 struct pfsnode *pfs = VTOPFS(ap->a_vp); 233 struct proc *procp; 234 struct proc *p; 235 int error; 236 int signo; 237 struct procfs_status *psp; 238 unsigned char flags; 239 240 procp = pfind(pfs->pfs_pid); 241 if (procp == NULL) 242 return ENOTTY; 243 p = ap->a_td->td_proc; 244 if (p == NULL) 245 return EINVAL; 246 247 /* Can't trace a process that's currently exec'ing. */ 248 if ((procp->p_flag & P_INEXEC) != 0) 249 return EAGAIN; 250 if (!CHECKIO(p, procp) || p_trespass(ap->a_cred, procp->p_ucred)) 251 return EPERM; 252 253 switch (ap->a_command) { 254 case PIOCBIS: 255 procp->p_stops |= *(unsigned int*)ap->a_data; 256 break; 257 case PIOCBIC: 258 procp->p_stops &= ~*(unsigned int*)ap->a_data; 259 break; 260 case PIOCSFL: 261 /* 262 * NFLAGS is "non-suser_xxx flags" -- currently, only 263 * PFS_ISUGID ("ignore set u/g id"); 264 */ 265 #define NFLAGS (PF_ISUGID) 266 flags = (unsigned char)*(unsigned int*)ap->a_data; 267 if (flags & NFLAGS && (error = suser_cred(ap->a_cred, 0))) 268 return error; 269 procp->p_pfsflags = flags; 270 break; 271 case PIOCGFL: 272 *(unsigned int*)ap->a_data = (unsigned int)procp->p_pfsflags; 273 break; 274 case PIOCSTATUS: 275 psp = (struct procfs_status *)ap->a_data; 276 psp->state = (procp->p_step == 0); 277 psp->flags = procp->p_pfsflags; 278 psp->events = procp->p_stops; 279 if (procp->p_step) { 280 psp->why = procp->p_stype; 281 psp->val = procp->p_xstat; 282 } else { 283 psp->why = psp->val = 0; /* Not defined values */ 284 } 285 break; 286 case PIOCWAIT: 287 psp = (struct procfs_status *)ap->a_data; 288 if (procp->p_step == 0) { 289 error = tsleep(&procp->p_stype, PCATCH, "piocwait", 0); 290 if (error) 291 return error; 292 } 293 psp->state = 1; /* It stopped */ 294 psp->flags = procp->p_pfsflags; 295 psp->events = procp->p_stops; 296 psp->why = procp->p_stype; /* why it stopped */ 297 psp->val = procp->p_xstat; /* any extra info */ 298 break; 299 case PIOCCONT: /* Restart a proc */ 300 if (procp->p_step == 0) 301 return EINVAL; /* Can only start a stopped process */ 302 if ((signo = *(int*)ap->a_data) != 0) { 303 if (signo >= NSIG || signo <= 0) 304 return EINVAL; 305 psignal(procp, signo); 306 } 307 procp->p_step = 0; 308 wakeup(&procp->p_step); 309 break; 310 default: 311 return (ENOTTY); 312 } 313 return 0; 314 } 315 316 /* 317 * do block mapping for pfsnode (vp). 318 * since we don't use the buffer cache 319 * for procfs this function should never 320 * be called. in any case, it's not clear 321 * what part of the kernel ever makes use 322 * of this function. for sanity, this is the 323 * usual no-op bmap, although returning 324 * (EIO) would be a reasonable alternative. 325 * 326 * procfs_bmap(struct vnode *a_vp, daddr_t a_bn, struct vnode **a_vpp, 327 * daddr_t *a_bnp, int *a_runp) 328 */ 329 static int 330 procfs_bmap(struct vop_bmap_args *ap) 331 { 332 if (ap->a_vpp != NULL) 333 *ap->a_vpp = ap->a_vp; 334 if (ap->a_bnp != NULL) 335 *ap->a_bnp = ap->a_bn; 336 if (ap->a_runp != NULL) 337 *ap->a_runp = 0; 338 return (0); 339 } 340 341 /* 342 * procfs_inactive is called when the pfsnode 343 * is vrele'd and the reference count goes 344 * to zero. (vp) will be on the vnode free 345 * list, so to get it back vget() must be 346 * used. 347 * 348 * (vp) is locked on entry, but must be unlocked on exit. 349 * 350 * procfs_inactive(struct vnode *a_vp, struct thread *a_td) 351 */ 352 static int 353 procfs_inactive(struct vop_inactive_args *ap) 354 { 355 /*struct vnode *vp = ap->a_vp;*/ 356 357 return (0); 358 } 359 360 /* 361 * _reclaim is called when getnewvnode() 362 * wants to make use of an entry on the vnode 363 * free list. at this time the filesystem needs 364 * to free any private data and remove the node 365 * from any private lists. 366 * 367 * procfs_reclaim(struct vnode *a_vp) 368 */ 369 static int 370 procfs_reclaim(struct vop_reclaim_args *ap) 371 { 372 return (procfs_freevp(ap->a_vp)); 373 } 374 375 /* 376 * _print is used for debugging. 377 * just print a readable description 378 * of (vp). 379 * 380 * procfs_print(struct vnode *a_vp) 381 */ 382 static int 383 procfs_print(struct vop_print_args *ap) 384 { 385 struct pfsnode *pfs = VTOPFS(ap->a_vp); 386 387 printf("tag VT_PROCFS, type %d, pid %ld, mode %x, flags %lx\n", 388 pfs->pfs_type, (long)pfs->pfs_pid, pfs->pfs_mode, pfs->pfs_flags); 389 return (0); 390 } 391 392 /* 393 * generic entry point for unsupported operations 394 */ 395 static int 396 procfs_badop(void) 397 { 398 return (EIO); 399 } 400 401 /* 402 * Invent attributes for pfsnode (vp) and store 403 * them in (vap). 404 * Directories lengths are returned as zero since 405 * any real length would require the genuine size 406 * to be computed, and nothing cares anyway. 407 * 408 * this is relatively minimal for procfs. 409 * 410 * procfs_getattr(struct vnode *a_vp, struct vattr *a_vap, 411 * struct ucred *a_cred, struct thread *a_td) 412 */ 413 static int 414 procfs_getattr(struct vop_getattr_args *ap) 415 { 416 struct pfsnode *pfs = VTOPFS(ap->a_vp); 417 struct vattr *vap = ap->a_vap; 418 struct proc *procp; 419 int error; 420 421 /* 422 * First make sure that the process and its credentials 423 * still exist. 424 */ 425 switch (pfs->pfs_type) { 426 case Proot: 427 case Pcurproc: 428 procp = 0; 429 break; 430 431 default: 432 procp = PFIND(pfs->pfs_pid); 433 if (procp == NULL || procp->p_ucred == NULL) 434 return (ENOENT); 435 } 436 437 error = 0; 438 439 /* start by zeroing out the attributes */ 440 VATTR_NULL(vap); 441 442 /* next do all the common fields */ 443 vap->va_type = ap->a_vp->v_type; 444 vap->va_mode = pfs->pfs_mode; 445 vap->va_fileid = pfs->pfs_fileno; 446 vap->va_flags = 0; 447 vap->va_blocksize = PAGE_SIZE; 448 vap->va_bytes = vap->va_size = 0; 449 vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0]; 450 451 /* 452 * Make all times be current TOD. 453 * It would be possible to get the process start 454 * time from the p_stat structure, but there's 455 * no "file creation" time stamp anyway, and the 456 * p_stat structure is not addressible if u. gets 457 * swapped out for that process. 458 */ 459 nanotime(&vap->va_ctime); 460 vap->va_atime = vap->va_mtime = vap->va_ctime; 461 462 /* 463 * If the process has exercised some setuid or setgid 464 * privilege, then rip away read/write permission so 465 * that only root can gain access. 466 */ 467 switch (pfs->pfs_type) { 468 case Pctl: 469 case Pregs: 470 case Pfpregs: 471 case Pdbregs: 472 case Pmem: 473 if (procp->p_flag & P_SUGID) 474 vap->va_mode &= ~((VREAD|VWRITE)| 475 ((VREAD|VWRITE)>>3)| 476 ((VREAD|VWRITE)>>6)); 477 break; 478 default: 479 break; 480 } 481 482 /* 483 * now do the object specific fields 484 * 485 * The size could be set from struct reg, but it's hardly 486 * worth the trouble, and it puts some (potentially) machine 487 * dependent data into this machine-independent code. If it 488 * becomes important then this function should break out into 489 * a per-file stat function in the corresponding .c file. 490 */ 491 492 vap->va_nlink = 1; 493 if (procp) { 494 vap->va_uid = procp->p_ucred->cr_uid; 495 vap->va_gid = procp->p_ucred->cr_gid; 496 } 497 498 switch (pfs->pfs_type) { 499 case Proot: 500 /* 501 * Set nlink to 1 to tell fts(3) we don't actually know. 502 */ 503 vap->va_nlink = 1; 504 vap->va_uid = 0; 505 vap->va_gid = 0; 506 vap->va_size = vap->va_bytes = DEV_BSIZE; 507 break; 508 509 case Pcurproc: { 510 char buf[16]; /* should be enough */ 511 vap->va_uid = 0; 512 vap->va_gid = 0; 513 vap->va_size = vap->va_bytes = 514 snprintf(buf, sizeof(buf), "%ld", (long)curproc->p_pid); 515 break; 516 } 517 518 case Pproc: 519 vap->va_nlink = nproc_targets; 520 vap->va_size = vap->va_bytes = DEV_BSIZE; 521 break; 522 523 case Pfile: { 524 char *fullpath, *freepath; 525 error = vn_fullpath(procp, NULL, &fullpath, &freepath); 526 if (error == 0) { 527 vap->va_size = strlen(fullpath); 528 free(freepath, M_TEMP); 529 } else { 530 vap->va_size = sizeof("unknown") - 1; 531 error = 0; 532 } 533 vap->va_bytes = vap->va_size; 534 break; 535 } 536 537 case Pmem: 538 /* 539 * If we denied owner access earlier, then we have to 540 * change the owner to root - otherwise 'ps' and friends 541 * will break even though they are setgid kmem. *SIGH* 542 */ 543 if (procp->p_flag & P_SUGID) 544 vap->va_uid = 0; 545 else 546 vap->va_uid = procp->p_ucred->cr_uid; 547 break; 548 549 case Pregs: 550 vap->va_bytes = vap->va_size = sizeof(struct reg); 551 break; 552 553 case Pfpregs: 554 vap->va_bytes = vap->va_size = sizeof(struct fpreg); 555 break; 556 557 case Pdbregs: 558 vap->va_bytes = vap->va_size = sizeof(struct dbreg); 559 break; 560 561 case Ptype: 562 case Pmap: 563 case Pctl: 564 case Pstatus: 565 case Pnote: 566 case Pnotepg: 567 case Pcmdline: 568 case Prlimit: 569 break; 570 571 default: 572 panic("procfs_getattr"); 573 } 574 575 return (error); 576 } 577 578 /* 579 * procfs_setattr(struct vnode *a_vp, struct vattr *a_vap, 580 * struct ucred *a_cred, struct thread *a_td) 581 */ 582 static int 583 procfs_setattr(struct vop_setattr_args *ap) 584 { 585 if (ap->a_vap->va_flags != VNOVAL) 586 return (EOPNOTSUPP); 587 588 /* 589 * just fake out attribute setting 590 * it's not good to generate an error 591 * return, otherwise things like creat() 592 * will fail when they try to set the 593 * file length to 0. worse, this means 594 * that echo $note > /proc/$pid/note will fail. 595 */ 596 597 return (0); 598 } 599 600 /* 601 * implement access checking. 602 * 603 * something very similar to this code is duplicated 604 * throughout the 4bsd kernel and should be moved 605 * into kern/vfs_subr.c sometime. 606 * 607 * actually, the check for super-user is slightly 608 * broken since it will allow read access to write-only 609 * objects. this doesn't cause any particular trouble 610 * but does mean that the i/o entry points need to check 611 * that the operation really does make sense. 612 * 613 * procfs_access(struct vnode *a_vp, int a_mode, struct ucred *a_cred, 614 * struct thread *a_td) 615 */ 616 static int 617 procfs_access(struct vop_access_args *ap) 618 { 619 struct vattr *vap; 620 struct vattr vattr; 621 int error; 622 623 /* 624 * If you're the super-user, 625 * you always get access. 626 */ 627 if (ap->a_cred->cr_uid == 0) 628 return (0); 629 630 vap = &vattr; 631 error = VOP_GETATTR(ap->a_vp, vap, ap->a_td); 632 if (error) 633 return (error); 634 635 /* 636 * Access check is based on only one of owner, group, public. 637 * If not owner, then check group. If not a member of the 638 * group, then check public access. 639 */ 640 if (ap->a_cred->cr_uid != vap->va_uid) { 641 gid_t *gp; 642 int i; 643 644 ap->a_mode >>= 3; 645 gp = ap->a_cred->cr_groups; 646 for (i = 0; i < ap->a_cred->cr_ngroups; i++, gp++) 647 if (vap->va_gid == *gp) 648 goto found; 649 ap->a_mode >>= 3; 650 found: 651 ; 652 } 653 654 if ((vap->va_mode & ap->a_mode) == ap->a_mode) 655 return (0); 656 657 return (EACCES); 658 } 659 660 /* 661 * lookup. this is incredibly complicated in the general case, however 662 * for most pseudo-filesystems very little needs to be done. 663 * 664 * procfs_lookup(struct vnode *a_dvp, struct vnode **a_vpp, 665 * struct componentname *a_cnp) 666 */ 667 static int 668 procfs_lookup(struct vop_old_lookup_args *ap) 669 { 670 struct componentname *cnp = ap->a_cnp; 671 struct vnode **vpp = ap->a_vpp; 672 struct vnode *dvp = ap->a_dvp; 673 char *pname = cnp->cn_nameptr; 674 /* struct proc *curp = cnp->cn_proc; */ 675 struct proc_target *pt; 676 pid_t pid; 677 struct pfsnode *pfs; 678 struct proc *p; 679 int i; 680 int error; 681 682 *vpp = NULL; 683 684 if (cnp->cn_nameiop == NAMEI_DELETE || cnp->cn_nameiop == NAMEI_RENAME) 685 return (EROFS); 686 687 error = 0; 688 if (cnp->cn_namelen == 1 && *pname == '.') { 689 *vpp = dvp; 690 vref(*vpp); 691 goto out; 692 } 693 694 pfs = VTOPFS(dvp); 695 switch (pfs->pfs_type) { 696 case Proot: 697 if (cnp->cn_flags & CNP_ISDOTDOT) 698 return (EIO); 699 700 if (CNEQ(cnp, "curproc", 7)) { 701 error = procfs_allocvp(dvp->v_mount, vpp, 0, Pcurproc); 702 goto out; 703 } 704 705 pid = atopid(pname, cnp->cn_namelen); 706 if (pid == NO_PID) 707 break; 708 709 p = PFIND(pid); 710 if (p == NULL) 711 break; 712 713 if (!PRISON_CHECK(ap->a_cnp->cn_cred, p->p_ucred)) 714 break; 715 716 if (ps_showallprocs == 0 && ap->a_cnp->cn_cred->cr_uid != 0 && 717 ap->a_cnp->cn_cred->cr_uid != p->p_ucred->cr_uid) 718 break; 719 720 error = procfs_allocvp(dvp->v_mount, vpp, pid, Pproc); 721 goto out; 722 723 case Pproc: 724 if (cnp->cn_flags & CNP_ISDOTDOT) { 725 error = procfs_root(dvp->v_mount, vpp); 726 goto out; 727 } 728 729 p = PFIND(pfs->pfs_pid); 730 if (p == NULL) 731 break; 732 733 if (!PRISON_CHECK(ap->a_cnp->cn_cred, p->p_ucred)) 734 break; 735 736 if (ps_showallprocs == 0 && ap->a_cnp->cn_cred->cr_uid != 0 && 737 ap->a_cnp->cn_cred->cr_uid != p->p_ucred->cr_uid) 738 break; 739 740 for (pt = proc_targets, i = 0; i < nproc_targets; pt++, i++) { 741 if (cnp->cn_namelen == pt->pt_namlen && 742 bcmp(pt->pt_name, pname, cnp->cn_namelen) == 0 && 743 (pt->pt_valid == NULL || (*pt->pt_valid)(p))) 744 goto found; 745 } 746 break; 747 found: 748 error = procfs_allocvp(dvp->v_mount, vpp, pfs->pfs_pid, 749 pt->pt_pfstype); 750 goto out; 751 752 default: 753 error = ENOTDIR; 754 goto out; 755 } 756 if (cnp->cn_nameiop == NAMEI_LOOKUP) 757 error = ENOENT; 758 else 759 error = EROFS; 760 /* 761 * If no error occured *vpp will hold a referenced locked vnode. 762 * dvp was passed to us locked and *vpp must be returned locked. 763 * If *vpp != dvp then we should unlock dvp if (1) this is not the 764 * last component or (2) CNP_LOCKPARENT is not set. 765 */ 766 out: 767 if (error == 0 && *vpp != dvp) { 768 if ((cnp->cn_flags & CNP_LOCKPARENT) == 0) { 769 cnp->cn_flags |= CNP_PDIRUNLOCK; 770 VOP_UNLOCK(dvp, 0, cnp->cn_td); 771 } 772 } 773 return (error); 774 } 775 776 /* 777 * Does this process have a text file? 778 */ 779 int 780 procfs_validfile(struct proc *p) 781 { 782 return (procfs_findtextvp(p) != NULLVP); 783 } 784 785 /* 786 * readdir() returns directory entries from pfsnode (vp). 787 * 788 * We generate just one directory entry at a time, as it would probably 789 * not pay off to buffer several entries locally to save uiomove calls. 790 * 791 * procfs_readdir(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred, 792 * int *a_eofflag, int *a_ncookies, u_long **a_cookies) 793 */ 794 static int 795 procfs_readdir(struct vop_readdir_args *ap) 796 { 797 struct pfsnode *pfs; 798 int error; 799 800 if (ap->a_uio->uio_offset < 0 || ap->a_uio->uio_offset > INT_MAX) 801 return (EINVAL); 802 803 pfs = VTOPFS(ap->a_vp); 804 805 switch (pfs->pfs_type) { 806 /* 807 * this is for the process-specific sub-directories. 808 * all that is needed to is copy out all the entries 809 * from the procent[] table (top of this file). 810 */ 811 case Pproc: 812 error = procfs_readdir_proc(ap); 813 break; 814 815 /* 816 * this is for the root of the procfs filesystem 817 * what is needed is a special entry for "curproc" 818 * followed by an entry for each process on allproc 819 */ 820 821 case Proot: 822 error = procfs_readdir_root(ap); 823 break; 824 825 default: 826 error = ENOTDIR; 827 break; 828 } 829 830 return (error); 831 } 832 833 static int 834 procfs_readdir_proc(struct vop_readdir_args *ap) 835 { 836 struct pfsnode *pfs; 837 int error, i, retval; 838 struct proc *p; 839 struct proc_target *pt; 840 struct uio *uio = ap->a_uio; 841 842 pfs = VTOPFS(ap->a_vp); 843 p = PFIND(pfs->pfs_pid); 844 if (p == NULL) 845 return(0); 846 if (!PRISON_CHECK(ap->a_cred, p->p_ucred)) 847 return(0); 848 849 error = 0; 850 i = uio->uio_offset; 851 852 for (pt = &proc_targets[i]; 853 !error && uio->uio_resid > 0 && i < nproc_targets; pt++, i++) { 854 if (pt->pt_valid && (*pt->pt_valid)(p) == 0) 855 continue; 856 857 retval = vop_write_dirent(&error, uio, 858 PROCFS_FILENO(pfs->pfs_pid, pt->pt_pfstype), pt->pt_type, 859 pt->pt_namlen, pt->pt_name); 860 if (retval) 861 break; 862 } 863 864 uio->uio_offset = i; 865 866 return(0); 867 } 868 869 static int 870 procfs_readdir_root(struct vop_readdir_args *ap) 871 { 872 int error, i, pcnt, retval; 873 struct uio *uio = ap->a_uio; 874 volatile struct proc *p = LIST_FIRST(&allproc); 875 ino_t d_ino; 876 const char *d_name; 877 char d_name_pid[20]; 878 size_t d_namlen; 879 uint8_t d_type; 880 881 error = 0; 882 pcnt = 0; 883 i = uio->uio_offset; 884 885 for (; p && uio->uio_resid > 0 && !error; i++, pcnt++) { 886 switch (i) { 887 case 0: /* `.' */ 888 d_ino = PROCFS_FILENO(0, Proot); 889 d_name = "."; 890 d_namlen = 1; 891 d_type = DT_DIR; 892 break; 893 case 1: /* `..' */ 894 d_ino = PROCFS_FILENO(0, Proot); 895 d_name = ".."; 896 d_namlen = 2; 897 d_type = DT_DIR; 898 break; 899 900 case 2: 901 d_ino = PROCFS_FILENO(0, Pcurproc); 902 d_namlen = 7; 903 d_name = "curproc"; 904 d_type = DT_LNK; 905 break; 906 907 908 default: 909 while (pcnt < i) { 910 p = LIST_NEXT(p, p_list); 911 if (!p) 912 goto done; 913 if (!PRISON_CHECK(ap->a_cred, p->p_ucred)) 914 continue; 915 pcnt++; 916 } 917 while (!PRISON_CHECK(ap->a_cred, p->p_ucred)) { 918 p = LIST_NEXT(p, p_list); 919 if (!p) 920 goto done; 921 } 922 if (ps_showallprocs == 0 && 923 ap->a_cred->cr_uid != 0 && 924 ap->a_cred->cr_uid != p->p_ucred->cr_uid) { 925 p = LIST_NEXT(p, p_list); 926 if (!p) 927 goto done; 928 continue; 929 } 930 931 d_ino = PROCFS_FILENO(p->p_pid, Pproc); 932 d_namlen = snprintf(d_name_pid, sizeof(d_name_pid), 933 "%ld", (long)p->p_pid); 934 d_name = d_name_pid; 935 d_type = DT_DIR; 936 p = LIST_NEXT(p, p_list); 937 break; 938 } 939 940 if (p) 941 PHOLD(p); 942 retval = vop_write_dirent(&error, uio, 943 d_ino, d_type, d_namlen, d_name); 944 if (p) 945 PRELE(p); 946 if (retval) 947 break; 948 } 949 done: 950 uio->uio_offset = i; 951 return(0); 952 } 953 954 /* 955 * readlink reads the link of `curproc' or `file' 956 */ 957 static int 958 procfs_readlink(struct vop_readlink_args *ap) 959 { 960 char buf[16]; /* should be enough */ 961 struct proc *procp; 962 struct vnode *vp = ap->a_vp; 963 struct pfsnode *pfs = VTOPFS(vp); 964 char *fullpath, *freepath; 965 int error, len; 966 967 switch (pfs->pfs_type) { 968 case Pcurproc: 969 if (pfs->pfs_fileno != PROCFS_FILENO(0, Pcurproc)) 970 return (EINVAL); 971 972 len = snprintf(buf, sizeof(buf), "%ld", (long)curproc->p_pid); 973 974 return (uiomove(buf, len, ap->a_uio)); 975 /* 976 * There _should_ be no way for an entire process to disappear 977 * from under us... 978 */ 979 case Pfile: 980 procp = PFIND(pfs->pfs_pid); 981 if (procp == NULL || procp->p_ucred == NULL) { 982 printf("procfs_readlink: pid %d disappeared\n", 983 pfs->pfs_pid); 984 return (uiomove("unknown", sizeof("unknown") - 1, 985 ap->a_uio)); 986 } 987 error = vn_fullpath(procp, NULL, &fullpath, &freepath); 988 if (error != 0) 989 return (uiomove("unknown", sizeof("unknown") - 1, 990 ap->a_uio)); 991 error = uiomove(fullpath, strlen(fullpath), ap->a_uio); 992 free(freepath, M_TEMP); 993 return (error); 994 default: 995 return (EINVAL); 996 } 997 } 998 999 /* 1000 * convert decimal ascii to pid_t 1001 */ 1002 static pid_t 1003 atopid(const char *b, u_int len) 1004 { 1005 pid_t p = 0; 1006 1007 while (len--) { 1008 char c = *b++; 1009 if (c < '0' || c > '9') 1010 return (NO_PID); 1011 p = 10 * p + (c - '0'); 1012 if (p > PID_MAX) 1013 return (NO_PID); 1014 } 1015 1016 return (p); 1017 } 1018 1019 /* 1020 * procfs vnode operations. 1021 */ 1022 struct vnodeopv_entry_desc procfs_vnodeop_entries[] = { 1023 { &vop_default_desc, vop_defaultop }, 1024 { &vop_access_desc, (vnodeopv_entry_t) procfs_access }, 1025 { &vop_advlock_desc, (vnodeopv_entry_t) procfs_badop }, 1026 { &vop_bmap_desc, (vnodeopv_entry_t) procfs_bmap }, 1027 { &vop_close_desc, (vnodeopv_entry_t) procfs_close }, 1028 { &vop_old_create_desc, (vnodeopv_entry_t) procfs_badop }, 1029 { &vop_getattr_desc, (vnodeopv_entry_t) procfs_getattr }, 1030 { &vop_inactive_desc, (vnodeopv_entry_t) procfs_inactive }, 1031 { &vop_old_link_desc, (vnodeopv_entry_t) procfs_badop }, 1032 { &vop_old_lookup_desc, (vnodeopv_entry_t) procfs_lookup }, 1033 { &vop_old_mkdir_desc, (vnodeopv_entry_t) procfs_badop }, 1034 { &vop_old_mknod_desc, (vnodeopv_entry_t) procfs_badop }, 1035 { &vop_open_desc, (vnodeopv_entry_t) procfs_open }, 1036 { &vop_pathconf_desc, (vnodeopv_entry_t) vop_stdpathconf }, 1037 { &vop_print_desc, (vnodeopv_entry_t) procfs_print }, 1038 { &vop_read_desc, (vnodeopv_entry_t) procfs_rw }, 1039 { &vop_readdir_desc, (vnodeopv_entry_t) procfs_readdir }, 1040 { &vop_readlink_desc, (vnodeopv_entry_t) procfs_readlink }, 1041 { &vop_reclaim_desc, (vnodeopv_entry_t) procfs_reclaim }, 1042 { &vop_old_remove_desc, (vnodeopv_entry_t) procfs_badop }, 1043 { &vop_old_rename_desc, (vnodeopv_entry_t) procfs_badop }, 1044 { &vop_old_rmdir_desc, (vnodeopv_entry_t) procfs_badop }, 1045 { &vop_setattr_desc, (vnodeopv_entry_t) procfs_setattr }, 1046 { &vop_old_symlink_desc, (vnodeopv_entry_t) procfs_badop }, 1047 { &vop_write_desc, (vnodeopv_entry_t) procfs_rw }, 1048 { &vop_ioctl_desc, (vnodeopv_entry_t) procfs_ioctl }, 1049 { NULL, NULL } 1050 }; 1051 1052