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 1.34 2006/07/18 22:22:16 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 (struct vop_generic_args *); 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 * procfs vnode operations. 88 */ 89 struct vop_ops procfs_vnode_vops = { 90 .vop_default = vop_defaultop, 91 .vop_access = procfs_access, 92 .vop_advlock = (void *)procfs_badop, 93 .vop_bmap = procfs_bmap, 94 .vop_close = procfs_close, 95 .vop_old_create = (void *)procfs_badop, 96 .vop_getattr = procfs_getattr, 97 .vop_inactive = procfs_inactive, 98 .vop_old_link = (void *)procfs_badop, 99 .vop_old_lookup = procfs_lookup, 100 .vop_old_mkdir = (void *)procfs_badop, 101 .vop_old_mknod = (void *)procfs_badop, 102 .vop_open = procfs_open, 103 .vop_pathconf = vop_stdpathconf, 104 .vop_print = procfs_print, 105 .vop_read = procfs_rw, 106 .vop_readdir = procfs_readdir, 107 .vop_readlink = procfs_readlink, 108 .vop_reclaim = procfs_reclaim, 109 .vop_old_remove = (void *)procfs_badop, 110 .vop_old_rename = (void *)procfs_badop, 111 .vop_old_rmdir = (void *)procfs_badop, 112 .vop_setattr = procfs_setattr, 113 .vop_old_symlink = (void *)procfs_badop, 114 .vop_write = (void *)procfs_rw, 115 .vop_ioctl = procfs_ioctl 116 }; 117 118 119 /* 120 * This is a list of the valid names in the 121 * process-specific sub-directories. It is 122 * used in procfs_lookup and procfs_readdir 123 */ 124 static struct proc_target { 125 u_char pt_type; 126 u_char pt_namlen; 127 char *pt_name; 128 pfstype pt_pfstype; 129 int (*pt_valid) (struct proc *p); 130 } proc_targets[] = { 131 #define N(s) sizeof(s)-1, s 132 /* name type validp */ 133 { DT_DIR, N("."), Pproc, NULL }, 134 { DT_DIR, N(".."), Proot, NULL }, 135 { DT_REG, N("mem"), Pmem, NULL }, 136 { DT_REG, N("regs"), Pregs, procfs_validregs }, 137 { DT_REG, N("fpregs"), Pfpregs, procfs_validfpregs }, 138 { DT_REG, N("dbregs"), Pdbregs, procfs_validdbregs }, 139 { DT_REG, N("ctl"), Pctl, NULL }, 140 { DT_REG, N("status"), Pstatus, NULL }, 141 { DT_REG, N("note"), Pnote, NULL }, 142 { DT_REG, N("notepg"), Pnotepg, NULL }, 143 { DT_REG, N("map"), Pmap, procfs_validmap }, 144 { DT_REG, N("etype"), Ptype, procfs_validtype }, 145 { DT_REG, N("cmdline"), Pcmdline, NULL }, 146 { DT_REG, N("rlimit"), Prlimit, NULL }, 147 { DT_LNK, N("file"), Pfile, NULL }, 148 #undef N 149 }; 150 static const int nproc_targets = sizeof(proc_targets) / sizeof(proc_targets[0]); 151 152 static pid_t atopid (const char *, u_int); 153 154 /* 155 * set things up for doing i/o on 156 * the pfsnode (vp). (vp) is locked 157 * on entry, and should be left locked 158 * on exit. 159 * 160 * for procfs we don't need to do anything 161 * in particular for i/o. all that is done 162 * is to support exclusive open on process 163 * memory images. 164 * 165 * procfs_open(struct vnode *a_vp, int a_mode, struct ucred *a_cred) 166 */ 167 static int 168 procfs_open(struct vop_open_args *ap) 169 { 170 struct pfsnode *pfs = VTOPFS(ap->a_vp); 171 struct proc *p1, *p2; 172 173 p2 = PFIND(pfs->pfs_pid); 174 if (p2 == NULL) 175 return (ENOENT); 176 if (pfs->pfs_pid && !PRISON_CHECK(ap->a_cred, p2->p_ucred)) 177 return (ENOENT); 178 179 switch (pfs->pfs_type) { 180 case Pmem: 181 if (((pfs->pfs_flags & FWRITE) && (ap->a_mode & O_EXCL)) || 182 ((pfs->pfs_flags & O_EXCL) && (ap->a_mode & FWRITE))) 183 return (EBUSY); 184 185 p1 = curproc; 186 KKASSERT(p1); 187 /* Can't trace a process that's currently exec'ing. */ 188 if ((p2->p_flag & P_INEXEC) != 0) 189 return EAGAIN; 190 if (!CHECKIO(p1, p2) || p_trespass(ap->a_cred, p2->p_ucred)) 191 return (EPERM); 192 193 if (ap->a_mode & FWRITE) 194 pfs->pfs_flags = ap->a_mode & (FWRITE|O_EXCL); 195 196 break; 197 198 default: 199 break; 200 } 201 202 return (vop_stdopen(ap)); 203 } 204 205 /* 206 * close the pfsnode (vp) after doing i/o. 207 * (vp) is not locked on entry or exit. 208 * 209 * nothing to do for procfs other than undo 210 * any exclusive open flag (see _open above). 211 * 212 * procfs_close(struct vnode *a_vp, int a_fflag, struct ucred *a_cred) 213 */ 214 static int 215 procfs_close(struct vop_close_args *ap) 216 { 217 struct pfsnode *pfs = VTOPFS(ap->a_vp); 218 struct proc *p; 219 220 switch (pfs->pfs_type) { 221 case Pmem: 222 if ((ap->a_fflag & FWRITE) && (pfs->pfs_flags & O_EXCL)) 223 pfs->pfs_flags &= ~(FWRITE|O_EXCL); 224 /* 225 * This rather complicated-looking code is trying to 226 * determine if this was the last close on this particular 227 * vnode. While one would expect v_usecount to be 1 at 228 * that point, it seems that (according to John Dyson) 229 * the VM system will bump up the usecount. So: if the 230 * usecount is 2, and VOBJBUF is set, then this is really 231 * the last close. Otherwise, if the usecount is < 2 232 * then it is definitely the last close. 233 * If this is the last close, then it checks to see if 234 * the target process has PF_LINGER set in p_pfsflags, 235 * if this is *not* the case, then the process' stop flags 236 * are cleared, and the process is woken up. This is 237 * to help prevent the case where a process has been 238 * told to stop on an event, but then the requesting process 239 * has gone away or forgotten about it. 240 */ 241 if ((ap->a_vp->v_usecount < 2) 242 && (p = pfind(pfs->pfs_pid)) 243 && !(p->p_pfsflags & PF_LINGER)) { 244 p->p_stops = 0; 245 p->p_step = 0; 246 wakeup(&p->p_step); 247 } 248 break; 249 default: 250 break; 251 } 252 253 return (vop_stdclose(ap)); 254 } 255 256 /* 257 * do an ioctl operation on a pfsnode (vp). 258 * (vp) is not locked on entry or exit. 259 */ 260 static int 261 procfs_ioctl(struct vop_ioctl_args *ap) 262 { 263 struct pfsnode *pfs = VTOPFS(ap->a_vp); 264 struct proc *procp; 265 struct proc *p; 266 int error; 267 int signo; 268 struct procfs_status *psp; 269 unsigned char flags; 270 271 procp = pfind(pfs->pfs_pid); 272 if (procp == NULL) 273 return ENOTTY; 274 p = curproc; 275 if (p == NULL) 276 return EINVAL; 277 278 /* Can't trace a process that's currently exec'ing. */ 279 if ((procp->p_flag & P_INEXEC) != 0) 280 return EAGAIN; 281 if (!CHECKIO(p, procp) || p_trespass(ap->a_cred, procp->p_ucred)) 282 return EPERM; 283 284 switch (ap->a_command) { 285 case PIOCBIS: 286 procp->p_stops |= *(unsigned int*)ap->a_data; 287 break; 288 case PIOCBIC: 289 procp->p_stops &= ~*(unsigned int*)ap->a_data; 290 break; 291 case PIOCSFL: 292 /* 293 * NFLAGS is "non-suser_xxx flags" -- currently, only 294 * PFS_ISUGID ("ignore set u/g id"); 295 */ 296 #define NFLAGS (PF_ISUGID) 297 flags = (unsigned char)*(unsigned int*)ap->a_data; 298 if (flags & NFLAGS && (error = suser_cred(ap->a_cred, 0))) 299 return error; 300 procp->p_pfsflags = flags; 301 break; 302 case PIOCGFL: 303 *(unsigned int*)ap->a_data = (unsigned int)procp->p_pfsflags; 304 break; 305 case PIOCSTATUS: 306 psp = (struct procfs_status *)ap->a_data; 307 psp->state = (procp->p_step == 0); 308 psp->flags = procp->p_pfsflags; 309 psp->events = procp->p_stops; 310 if (procp->p_step) { 311 psp->why = procp->p_stype; 312 psp->val = procp->p_xstat; 313 } else { 314 psp->why = psp->val = 0; /* Not defined values */ 315 } 316 break; 317 case PIOCWAIT: 318 psp = (struct procfs_status *)ap->a_data; 319 if (procp->p_step == 0) { 320 error = tsleep(&procp->p_stype, PCATCH, "piocwait", 0); 321 if (error) 322 return error; 323 } 324 psp->state = 1; /* It stopped */ 325 psp->flags = procp->p_pfsflags; 326 psp->events = procp->p_stops; 327 psp->why = procp->p_stype; /* why it stopped */ 328 psp->val = procp->p_xstat; /* any extra info */ 329 break; 330 case PIOCCONT: /* Restart a proc */ 331 if (procp->p_step == 0) 332 return EINVAL; /* Can only start a stopped process */ 333 if ((signo = *(int*)ap->a_data) != 0) { 334 if (signo >= NSIG || signo <= 0) 335 return EINVAL; 336 psignal(procp, signo); 337 } 338 procp->p_step = 0; 339 wakeup(&procp->p_step); 340 break; 341 default: 342 return (ENOTTY); 343 } 344 return 0; 345 } 346 347 /* 348 * do block mapping for pfsnode (vp). 349 * since we don't use the buffer cache 350 * for procfs this function should never 351 * be called. in any case, it's not clear 352 * what part of the kernel ever makes use 353 * of this function. for sanity, this is the 354 * usual no-op bmap, although returning 355 * (EIO) would be a reasonable alternative. 356 * 357 * procfs_bmap(struct vnode *a_vp, off_t a_loffset, struct vnode **a_vpp, 358 * off_t *a_doffsetp, int *a_runp) 359 */ 360 static int 361 procfs_bmap(struct vop_bmap_args *ap) 362 { 363 if (ap->a_vpp != NULL) 364 *ap->a_vpp = ap->a_vp; 365 if (ap->a_doffsetp != NULL) 366 *ap->a_doffsetp = ap->a_loffset; 367 if (ap->a_runp != NULL) 368 *ap->a_runp = 0; 369 if (ap->a_runb != NULL) 370 *ap->a_runb = 0; 371 return (0); 372 } 373 374 /* 375 * procfs_inactive is called when the pfsnode 376 * is vrele'd and the reference count goes 377 * to zero. (vp) will be on the vnode free 378 * list, so to get it back vget() must be 379 * used. 380 * 381 * (vp) is locked on entry, but must be unlocked on exit. 382 * 383 * procfs_inactive(struct vnode *a_vp, struct thread *a_td) 384 */ 385 static int 386 procfs_inactive(struct vop_inactive_args *ap) 387 { 388 /*struct vnode *vp = ap->a_vp;*/ 389 390 return (0); 391 } 392 393 /* 394 * _reclaim is called when getnewvnode() 395 * wants to make use of an entry on the vnode 396 * free list. at this time the filesystem needs 397 * to free any private data and remove the node 398 * from any private lists. 399 * 400 * procfs_reclaim(struct vnode *a_vp) 401 */ 402 static int 403 procfs_reclaim(struct vop_reclaim_args *ap) 404 { 405 return (procfs_freevp(ap->a_vp)); 406 } 407 408 /* 409 * _print is used for debugging. 410 * just print a readable description 411 * of (vp). 412 * 413 * procfs_print(struct vnode *a_vp) 414 */ 415 static int 416 procfs_print(struct vop_print_args *ap) 417 { 418 struct pfsnode *pfs = VTOPFS(ap->a_vp); 419 420 printf("tag VT_PROCFS, type %d, pid %ld, mode %x, flags %lx\n", 421 pfs->pfs_type, (long)pfs->pfs_pid, pfs->pfs_mode, pfs->pfs_flags); 422 return (0); 423 } 424 425 /* 426 * generic entry point for unsupported operations 427 */ 428 static int 429 procfs_badop(struct vop_generic_args *ap) 430 { 431 return (EIO); 432 } 433 434 /* 435 * Invent attributes for pfsnode (vp) and store 436 * them in (vap). 437 * Directories lengths are returned as zero since 438 * any real length would require the genuine size 439 * to be computed, and nothing cares anyway. 440 * 441 * this is relatively minimal for procfs. 442 * 443 * procfs_getattr(struct vnode *a_vp, struct vattr *a_vap, 444 * struct ucred *a_cred, struct thread *a_td) 445 */ 446 static int 447 procfs_getattr(struct vop_getattr_args *ap) 448 { 449 struct pfsnode *pfs = VTOPFS(ap->a_vp); 450 struct vattr *vap = ap->a_vap; 451 struct proc *procp; 452 int error; 453 454 /* 455 * First make sure that the process and its credentials 456 * still exist. 457 */ 458 switch (pfs->pfs_type) { 459 case Proot: 460 case Pcurproc: 461 procp = 0; 462 break; 463 464 default: 465 procp = PFIND(pfs->pfs_pid); 466 if (procp == NULL || procp->p_ucred == NULL) 467 return (ENOENT); 468 } 469 470 error = 0; 471 472 /* start by zeroing out the attributes */ 473 VATTR_NULL(vap); 474 475 /* next do all the common fields */ 476 vap->va_type = ap->a_vp->v_type; 477 vap->va_mode = pfs->pfs_mode; 478 vap->va_fileid = pfs->pfs_fileno; 479 vap->va_flags = 0; 480 vap->va_blocksize = PAGE_SIZE; 481 vap->va_bytes = vap->va_size = 0; 482 vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0]; 483 484 /* 485 * Make all times be current TOD. 486 * It would be possible to get the process start 487 * time from the p_stat structure, but there's 488 * no "file creation" time stamp anyway, and the 489 * p_stat structure is not addressible if u. gets 490 * swapped out for that process. 491 */ 492 nanotime(&vap->va_ctime); 493 vap->va_atime = vap->va_mtime = vap->va_ctime; 494 495 /* 496 * If the process has exercised some setuid or setgid 497 * privilege, then rip away read/write permission so 498 * that only root can gain access. 499 */ 500 switch (pfs->pfs_type) { 501 case Pctl: 502 case Pregs: 503 case Pfpregs: 504 case Pdbregs: 505 case Pmem: 506 if (procp->p_flag & P_SUGID) 507 vap->va_mode &= ~((VREAD|VWRITE)| 508 ((VREAD|VWRITE)>>3)| 509 ((VREAD|VWRITE)>>6)); 510 break; 511 default: 512 break; 513 } 514 515 /* 516 * now do the object specific fields 517 * 518 * The size could be set from struct reg, but it's hardly 519 * worth the trouble, and it puts some (potentially) machine 520 * dependent data into this machine-independent code. If it 521 * becomes important then this function should break out into 522 * a per-file stat function in the corresponding .c file. 523 */ 524 525 vap->va_nlink = 1; 526 if (procp) { 527 vap->va_uid = procp->p_ucred->cr_uid; 528 vap->va_gid = procp->p_ucred->cr_gid; 529 } 530 531 switch (pfs->pfs_type) { 532 case Proot: 533 /* 534 * Set nlink to 1 to tell fts(3) we don't actually know. 535 */ 536 vap->va_nlink = 1; 537 vap->va_uid = 0; 538 vap->va_gid = 0; 539 vap->va_size = vap->va_bytes = DEV_BSIZE; 540 break; 541 542 case Pcurproc: { 543 char buf[16]; /* should be enough */ 544 vap->va_uid = 0; 545 vap->va_gid = 0; 546 vap->va_size = vap->va_bytes = 547 snprintf(buf, sizeof(buf), "%ld", (long)curproc->p_pid); 548 break; 549 } 550 551 case Pproc: 552 vap->va_nlink = nproc_targets; 553 vap->va_size = vap->va_bytes = DEV_BSIZE; 554 break; 555 556 case Pfile: { 557 char *fullpath, *freepath; 558 error = vn_fullpath(procp, NULL, &fullpath, &freepath); 559 if (error == 0) { 560 vap->va_size = strlen(fullpath); 561 free(freepath, M_TEMP); 562 } else { 563 vap->va_size = sizeof("unknown") - 1; 564 error = 0; 565 } 566 vap->va_bytes = vap->va_size; 567 break; 568 } 569 570 case Pmem: 571 /* 572 * If we denied owner access earlier, then we have to 573 * change the owner to root - otherwise 'ps' and friends 574 * will break even though they are setgid kmem. *SIGH* 575 */ 576 if (procp->p_flag & P_SUGID) 577 vap->va_uid = 0; 578 else 579 vap->va_uid = procp->p_ucred->cr_uid; 580 break; 581 582 case Pregs: 583 vap->va_bytes = vap->va_size = sizeof(struct reg); 584 break; 585 586 case Pfpregs: 587 vap->va_bytes = vap->va_size = sizeof(struct fpreg); 588 break; 589 590 case Pdbregs: 591 vap->va_bytes = vap->va_size = sizeof(struct dbreg); 592 break; 593 594 case Ptype: 595 case Pmap: 596 case Pctl: 597 case Pstatus: 598 case Pnote: 599 case Pnotepg: 600 case Pcmdline: 601 case Prlimit: 602 break; 603 604 default: 605 panic("procfs_getattr"); 606 } 607 608 return (error); 609 } 610 611 /* 612 * procfs_setattr(struct vnode *a_vp, struct vattr *a_vap, 613 * struct ucred *a_cred, struct thread *a_td) 614 */ 615 static int 616 procfs_setattr(struct vop_setattr_args *ap) 617 { 618 if (ap->a_vap->va_flags != VNOVAL) 619 return (EOPNOTSUPP); 620 621 /* 622 * just fake out attribute setting 623 * it's not good to generate an error 624 * return, otherwise things like creat() 625 * will fail when they try to set the 626 * file length to 0. worse, this means 627 * that echo $note > /proc/$pid/note will fail. 628 */ 629 630 return (0); 631 } 632 633 /* 634 * implement access checking. 635 * 636 * something very similar to this code is duplicated 637 * throughout the 4bsd kernel and should be moved 638 * into kern/vfs_subr.c sometime. 639 * 640 * actually, the check for super-user is slightly 641 * broken since it will allow read access to write-only 642 * objects. this doesn't cause any particular trouble 643 * but does mean that the i/o entry points need to check 644 * that the operation really does make sense. 645 * 646 * procfs_access(struct vnode *a_vp, int a_mode, struct ucred *a_cred, 647 * struct thread *a_td) 648 */ 649 static int 650 procfs_access(struct vop_access_args *ap) 651 { 652 struct vattr *vap; 653 struct vattr vattr; 654 int error; 655 656 /* 657 * If you're the super-user, 658 * you always get access. 659 */ 660 if (ap->a_cred->cr_uid == 0) 661 return (0); 662 663 vap = &vattr; 664 error = VOP_GETATTR(ap->a_vp, vap); 665 if (error) 666 return (error); 667 668 /* 669 * Access check is based on only one of owner, group, public. 670 * If not owner, then check group. If not a member of the 671 * group, then check public access. 672 */ 673 if (ap->a_cred->cr_uid != vap->va_uid) { 674 gid_t *gp; 675 int i; 676 677 ap->a_mode >>= 3; 678 gp = ap->a_cred->cr_groups; 679 for (i = 0; i < ap->a_cred->cr_ngroups; i++, gp++) 680 if (vap->va_gid == *gp) 681 goto found; 682 ap->a_mode >>= 3; 683 found: 684 ; 685 } 686 687 if ((vap->va_mode & ap->a_mode) == ap->a_mode) 688 return (0); 689 690 return (EACCES); 691 } 692 693 /* 694 * lookup. this is incredibly complicated in the general case, however 695 * for most pseudo-filesystems very little needs to be done. 696 * 697 * procfs_lookup(struct vnode *a_dvp, struct vnode **a_vpp, 698 * struct componentname *a_cnp) 699 */ 700 static int 701 procfs_lookup(struct vop_old_lookup_args *ap) 702 { 703 struct componentname *cnp = ap->a_cnp; 704 struct vnode **vpp = ap->a_vpp; 705 struct vnode *dvp = ap->a_dvp; 706 char *pname = cnp->cn_nameptr; 707 /* struct proc *curp = cnp->cn_proc; */ 708 struct proc_target *pt; 709 pid_t pid; 710 struct pfsnode *pfs; 711 struct proc *p; 712 int i; 713 int error; 714 715 *vpp = NULL; 716 717 if (cnp->cn_nameiop == NAMEI_DELETE || cnp->cn_nameiop == NAMEI_RENAME) 718 return (EROFS); 719 720 error = 0; 721 if (cnp->cn_namelen == 1 && *pname == '.') { 722 *vpp = dvp; 723 vref(*vpp); 724 goto out; 725 } 726 727 pfs = VTOPFS(dvp); 728 switch (pfs->pfs_type) { 729 case Proot: 730 if (cnp->cn_flags & CNP_ISDOTDOT) 731 return (EIO); 732 733 if (CNEQ(cnp, "curproc", 7)) { 734 error = procfs_allocvp(dvp->v_mount, vpp, 0, Pcurproc); 735 goto out; 736 } 737 738 pid = atopid(pname, cnp->cn_namelen); 739 if (pid == NO_PID) 740 break; 741 742 p = PFIND(pid); 743 if (p == NULL) 744 break; 745 746 if (!PRISON_CHECK(ap->a_cnp->cn_cred, p->p_ucred)) 747 break; 748 749 if (ps_showallprocs == 0 && ap->a_cnp->cn_cred->cr_uid != 0 && 750 ap->a_cnp->cn_cred->cr_uid != p->p_ucred->cr_uid) 751 break; 752 753 error = procfs_allocvp(dvp->v_mount, vpp, pid, Pproc); 754 goto out; 755 756 case Pproc: 757 if (cnp->cn_flags & CNP_ISDOTDOT) { 758 error = procfs_root(dvp->v_mount, vpp); 759 goto out; 760 } 761 762 p = PFIND(pfs->pfs_pid); 763 if (p == NULL) 764 break; 765 766 if (!PRISON_CHECK(ap->a_cnp->cn_cred, p->p_ucred)) 767 break; 768 769 if (ps_showallprocs == 0 && ap->a_cnp->cn_cred->cr_uid != 0 && 770 ap->a_cnp->cn_cred->cr_uid != p->p_ucred->cr_uid) 771 break; 772 773 for (pt = proc_targets, i = 0; i < nproc_targets; pt++, i++) { 774 if (cnp->cn_namelen == pt->pt_namlen && 775 bcmp(pt->pt_name, pname, cnp->cn_namelen) == 0 && 776 (pt->pt_valid == NULL || (*pt->pt_valid)(p))) 777 goto found; 778 } 779 break; 780 found: 781 error = procfs_allocvp(dvp->v_mount, vpp, pfs->pfs_pid, 782 pt->pt_pfstype); 783 goto out; 784 785 default: 786 error = ENOTDIR; 787 goto out; 788 } 789 if (cnp->cn_nameiop == NAMEI_LOOKUP) 790 error = ENOENT; 791 else 792 error = EROFS; 793 /* 794 * If no error occured *vpp will hold a referenced locked vnode. 795 * dvp was passed to us locked and *vpp must be returned locked. 796 * If *vpp != dvp then we should unlock dvp if (1) this is not the 797 * last component or (2) CNP_LOCKPARENT is not set. 798 */ 799 out: 800 if (error == 0 && *vpp != dvp) { 801 if ((cnp->cn_flags & CNP_LOCKPARENT) == 0) { 802 cnp->cn_flags |= CNP_PDIRUNLOCK; 803 VOP_UNLOCK(dvp, 0); 804 } 805 } 806 return (error); 807 } 808 809 /* 810 * Does this process have a text file? 811 */ 812 int 813 procfs_validfile(struct proc *p) 814 { 815 return (procfs_findtextvp(p) != NULLVP); 816 } 817 818 /* 819 * readdir() returns directory entries from pfsnode (vp). 820 * 821 * We generate just one directory entry at a time, as it would probably 822 * not pay off to buffer several entries locally to save uiomove calls. 823 * 824 * procfs_readdir(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred, 825 * int *a_eofflag, int *a_ncookies, u_long **a_cookies) 826 */ 827 static int 828 procfs_readdir(struct vop_readdir_args *ap) 829 { 830 struct pfsnode *pfs; 831 int error; 832 833 if (ap->a_uio->uio_offset < 0 || ap->a_uio->uio_offset > INT_MAX) 834 return (EINVAL); 835 836 pfs = VTOPFS(ap->a_vp); 837 838 switch (pfs->pfs_type) { 839 /* 840 * this is for the process-specific sub-directories. 841 * all that is needed to is copy out all the entries 842 * from the procent[] table (top of this file). 843 */ 844 case Pproc: 845 error = procfs_readdir_proc(ap); 846 break; 847 848 /* 849 * this is for the root of the procfs filesystem 850 * what is needed is a special entry for "curproc" 851 * followed by an entry for each process on allproc 852 */ 853 854 case Proot: 855 error = procfs_readdir_root(ap); 856 break; 857 858 default: 859 error = ENOTDIR; 860 break; 861 } 862 863 return (error); 864 } 865 866 static int 867 procfs_readdir_proc(struct vop_readdir_args *ap) 868 { 869 struct pfsnode *pfs; 870 int error, i, retval; 871 struct proc *p; 872 struct proc_target *pt; 873 struct uio *uio = ap->a_uio; 874 875 pfs = VTOPFS(ap->a_vp); 876 p = PFIND(pfs->pfs_pid); 877 if (p == NULL) 878 return(0); 879 if (!PRISON_CHECK(ap->a_cred, p->p_ucred)) 880 return(0); 881 882 error = 0; 883 i = (int)uio->uio_offset; 884 if (i < 0) 885 return (EINVAL); 886 887 for (pt = &proc_targets[i]; 888 !error && uio->uio_resid > 0 && i < nproc_targets; pt++, i++) { 889 if (pt->pt_valid && (*pt->pt_valid)(p) == 0) 890 continue; 891 892 retval = vop_write_dirent(&error, uio, 893 PROCFS_FILENO(pfs->pfs_pid, pt->pt_pfstype), pt->pt_type, 894 pt->pt_namlen, pt->pt_name); 895 if (retval) 896 break; 897 } 898 899 uio->uio_offset = (off_t)i; 900 901 return(0); 902 } 903 904 struct procfs_readdir_root_info { 905 int error; 906 int i; 907 int pcnt; 908 struct uio *uio; 909 struct ucred *cred; 910 }; 911 912 static int procfs_readdir_root_callback(struct proc *p, void *data); 913 914 static int 915 procfs_readdir_root(struct vop_readdir_args *ap) 916 { 917 struct procfs_readdir_root_info info; 918 struct uio *uio = ap->a_uio; 919 int res; 920 921 info.error = 0; 922 info.i = (int)uio->uio_offset; 923 924 if (info.i < 0) 925 return (EINVAL); 926 927 info.pcnt = 0; 928 info.uio = uio; 929 info.cred = ap->a_cred; 930 while (info.pcnt < 3) { 931 res = procfs_readdir_root_callback(NULL, &info); 932 if (res < 0) 933 break; 934 } 935 if (res >= 0) 936 allproc_scan(procfs_readdir_root_callback, &info); 937 uio->uio_offset = (off_t)info.i; 938 939 return (info.error); 940 } 941 942 static int 943 procfs_readdir_root_callback(struct proc *p, void *data) 944 { 945 struct procfs_readdir_root_info *info = data; 946 struct uio *uio; 947 int retval; 948 ino_t d_ino; 949 const char *d_name; 950 char d_name_pid[20]; 951 size_t d_namlen; 952 uint8_t d_type; 953 954 uio = info->uio; 955 956 if (uio->uio_resid <= 0 || info->error) 957 return(-1); 958 959 switch (info->pcnt) { 960 case 0: /* `.' */ 961 d_ino = PROCFS_FILENO(0, Proot); 962 d_name = "."; 963 d_namlen = 1; 964 d_type = DT_DIR; 965 break; 966 case 1: /* `..' */ 967 d_ino = PROCFS_FILENO(0, Proot); 968 d_name = ".."; 969 d_namlen = 2; 970 d_type = DT_DIR; 971 break; 972 973 case 2: 974 d_ino = PROCFS_FILENO(0, Pcurproc); 975 d_namlen = 7; 976 d_name = "curproc"; 977 d_type = DT_LNK; 978 break; 979 980 981 default: 982 if (!PRISON_CHECK(info->cred, p->p_ucred)) 983 return(0); 984 if (ps_showallprocs == 0 && 985 info->cred->cr_uid != 0 && 986 info->cred->cr_uid != p->p_ucred->cr_uid) { 987 return(0); 988 } 989 990 /* 991 * Skip entries we have already returned (optimization) 992 */ 993 if (info->pcnt < info->i) { 994 ++info->pcnt; 995 return(0); 996 } 997 998 d_ino = PROCFS_FILENO(p->p_pid, Pproc); 999 d_namlen = snprintf(d_name_pid, sizeof(d_name_pid), 1000 "%ld", (long)p->p_pid); 1001 d_name = d_name_pid; 1002 d_type = DT_DIR; 1003 break; 1004 } 1005 1006 /* 1007 * Skip entries we have already returned (optimization) 1008 */ 1009 if (info->pcnt < info->i) { 1010 ++info->pcnt; 1011 return(0); 1012 } 1013 1014 retval = vop_write_dirent(&info->error, uio, 1015 d_ino, d_type, d_namlen, d_name); 1016 if (retval) 1017 return(-1); 1018 ++info->pcnt; 1019 ++info->i; 1020 return(0); 1021 } 1022 1023 /* 1024 * readlink reads the link of `curproc' or `file' 1025 */ 1026 static int 1027 procfs_readlink(struct vop_readlink_args *ap) 1028 { 1029 char buf[16]; /* should be enough */ 1030 struct proc *procp; 1031 struct vnode *vp = ap->a_vp; 1032 struct pfsnode *pfs = VTOPFS(vp); 1033 char *fullpath, *freepath; 1034 int error, len; 1035 1036 switch (pfs->pfs_type) { 1037 case Pcurproc: 1038 if (pfs->pfs_fileno != PROCFS_FILENO(0, Pcurproc)) 1039 return (EINVAL); 1040 1041 len = snprintf(buf, sizeof(buf), "%ld", (long)curproc->p_pid); 1042 1043 return (uiomove(buf, len, ap->a_uio)); 1044 /* 1045 * There _should_ be no way for an entire process to disappear 1046 * from under us... 1047 */ 1048 case Pfile: 1049 procp = PFIND(pfs->pfs_pid); 1050 if (procp == NULL || procp->p_ucred == NULL) { 1051 printf("procfs_readlink: pid %d disappeared\n", 1052 pfs->pfs_pid); 1053 return (uiomove("unknown", sizeof("unknown") - 1, 1054 ap->a_uio)); 1055 } 1056 error = vn_fullpath(procp, NULL, &fullpath, &freepath); 1057 if (error != 0) 1058 return (uiomove("unknown", sizeof("unknown") - 1, 1059 ap->a_uio)); 1060 error = uiomove(fullpath, strlen(fullpath), ap->a_uio); 1061 free(freepath, M_TEMP); 1062 return (error); 1063 default: 1064 return (EINVAL); 1065 } 1066 } 1067 1068 /* 1069 * convert decimal ascii to pid_t 1070 */ 1071 static pid_t 1072 atopid(const char *b, u_int len) 1073 { 1074 pid_t p = 0; 1075 1076 while (len--) { 1077 char c = *b++; 1078 if (c < '0' || c > '9') 1079 return (NO_PID); 1080 p = 10 * p + (c - '0'); 1081 if (p > PID_MAX) 1082 return (NO_PID); 1083 } 1084 1085 return (p); 1086 } 1087 1088