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 */ 41 42 /* 43 * procfs vnode interface 44 */ 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/time.h> 49 #include <sys/kernel.h> 50 #include <sys/lock.h> 51 #include <sys/fcntl.h> 52 #include <sys/proc.h> 53 #include <sys/priv.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 <sys/reg.h> 62 #include <vm/vm_zone.h> 63 #include <vfs/procfs/procfs.h> 64 #include <sys/pioctl.h> 65 66 #include <sys/spinlock2.h> 67 68 #include <machine/limits.h> 69 70 static int procfs_access (struct vop_access_args *); 71 static int procfs_badop (struct vop_generic_args *); 72 static int procfs_bmap (struct vop_bmap_args *); 73 static int procfs_close (struct vop_close_args *); 74 static int procfs_getattr (struct vop_getattr_args *); 75 static int procfs_inactive (struct vop_inactive_args *); 76 static int procfs_ioctl (struct vop_ioctl_args *); 77 static int procfs_lookup (struct vop_old_lookup_args *); 78 static int procfs_open (struct vop_open_args *); 79 static int procfs_print (struct vop_print_args *); 80 static int procfs_readdir (struct vop_readdir_args *); 81 static int procfs_readlink (struct vop_readlink_args *); 82 static int procfs_reclaim (struct vop_reclaim_args *); 83 static int procfs_setattr (struct vop_setattr_args *); 84 85 static int procfs_readdir_proc(struct vop_readdir_args *); 86 static int procfs_readdir_root(struct vop_readdir_args *); 87 88 /* 89 * procfs vnode operations. 90 */ 91 struct vop_ops procfs_vnode_vops = { 92 .vop_default = vop_defaultop, 93 .vop_access = procfs_access, 94 .vop_advlock = (void *)procfs_badop, 95 .vop_bmap = procfs_bmap, 96 .vop_close = procfs_close, 97 .vop_old_create = (void *)procfs_badop, 98 .vop_getattr = procfs_getattr, 99 .vop_inactive = procfs_inactive, 100 .vop_old_link = (void *)procfs_badop, 101 .vop_old_lookup = procfs_lookup, 102 .vop_old_mkdir = (void *)procfs_badop, 103 .vop_old_mknod = (void *)procfs_badop, 104 .vop_open = procfs_open, 105 .vop_pathconf = vop_stdpathconf, 106 .vop_print = procfs_print, 107 .vop_read = procfs_rw, 108 .vop_readdir = procfs_readdir, 109 .vop_readlink = procfs_readlink, 110 .vop_reclaim = procfs_reclaim, 111 .vop_old_remove = (void *)procfs_badop, 112 .vop_old_rename = (void *)procfs_badop, 113 .vop_old_rmdir = (void *)procfs_badop, 114 .vop_setattr = procfs_setattr, 115 .vop_old_symlink = (void *)procfs_badop, 116 .vop_write = (void *)procfs_rw, 117 .vop_ioctl = procfs_ioctl 118 }; 119 120 121 /* 122 * This is a list of the valid names in the 123 * process-specific sub-directories. It is 124 * used in procfs_lookup and procfs_readdir 125 */ 126 static struct proc_target { 127 u_char pt_type; 128 u_char pt_namlen; 129 char *pt_name; 130 pfstype pt_pfstype; 131 int (*pt_valid) (struct lwp *p); 132 } proc_targets[] = { 133 #define N(s) sizeof(s)-1, s 134 /* name type validp */ 135 { DT_DIR, N("."), Pproc, NULL }, 136 { DT_DIR, N(".."), Proot, NULL }, 137 { DT_REG, N("mem"), Pmem, NULL }, 138 { DT_REG, N("regs"), Pregs, procfs_validregs }, 139 { DT_REG, N("fpregs"), Pfpregs, procfs_validfpregs }, 140 { DT_REG, N("dbregs"), Pdbregs, procfs_validdbregs }, 141 { DT_REG, N("ctl"), Pctl, NULL }, 142 { DT_REG, N("status"), Pstatus, NULL }, 143 { DT_REG, N("note"), Pnote, NULL }, 144 { DT_REG, N("notepg"), Pnotepg, NULL }, 145 { DT_REG, N("map"), Pmap, procfs_validmap }, 146 { DT_REG, N("etype"), Ptype, procfs_validtype }, 147 { DT_REG, N("cmdline"), Pcmdline, NULL }, 148 { DT_REG, N("rlimit"), Prlimit, NULL }, 149 { DT_LNK, N("file"), Pfile, NULL }, 150 #undef N 151 }; 152 static const int nproc_targets = NELEM(proc_targets); 153 154 static pid_t atopid (const char *, u_int); 155 156 /* 157 * set things up for doing i/o on 158 * the pfsnode (vp). (vp) is locked 159 * on entry, and should be left locked 160 * on exit. 161 * 162 * for procfs we don't need to do anything 163 * in particular for i/o. all that is done 164 * is to support exclusive open on process 165 * memory images. 166 * 167 * procfs_open(struct vnode *a_vp, int a_mode, struct ucred *a_cred, 168 * struct file *a_fp) 169 */ 170 static int 171 procfs_open(struct vop_open_args *ap) 172 { 173 struct pfsnode *pfs = VTOPFS(ap->a_vp); 174 struct proc *p1, *p2; 175 int error; 176 177 p2 = pfs_pfind(pfs->pfs_pid); 178 if (p2 == NULL) 179 return (ENOENT); 180 if (pfs->pfs_pid && !PRISON_CHECK(ap->a_cred, p2->p_ucred)) { 181 error = ENOENT; 182 goto done; 183 } 184 185 switch (pfs->pfs_type) { 186 case Pmem: 187 if (((pfs->pfs_flags & FWRITE) && (ap->a_mode & O_EXCL)) || 188 ((pfs->pfs_flags & O_EXCL) && (ap->a_mode & FWRITE))) { 189 error = EBUSY; 190 goto done; 191 } 192 193 p1 = curproc; 194 KKASSERT(p1); 195 /* Can't trace a process that's currently exec'ing. */ 196 if ((p2->p_flags & P_INEXEC) != 0) { 197 error = EAGAIN; 198 goto done; 199 } 200 if (!CHECKIO(p1, p2) || p_trespass(ap->a_cred, p2->p_ucred)) { 201 error = EPERM; 202 goto done; 203 } 204 205 if (ap->a_mode & FWRITE) 206 pfs->pfs_flags = ap->a_mode & (FWRITE|O_EXCL); 207 208 break; 209 210 default: 211 break; 212 } 213 error = vop_stdopen(ap); 214 done: 215 pfs_pdone(p2); 216 return error; 217 } 218 219 /* 220 * close the pfsnode (vp) after doing i/o. 221 * (vp) is not locked on entry or exit. 222 * 223 * nothing to do for procfs other than undo 224 * any exclusive open flag (see _open above). 225 * 226 * procfs_close(struct vnode *a_vp, int a_fflag, struct ucred *a_cred) 227 */ 228 static int 229 procfs_close(struct vop_close_args *ap) 230 { 231 struct pfsnode *pfs = VTOPFS(ap->a_vp); 232 struct proc *p; 233 234 switch (pfs->pfs_type) { 235 case Pmem: 236 if ((ap->a_fflag & FWRITE) && (pfs->pfs_flags & O_EXCL)) 237 pfs->pfs_flags &= ~(FWRITE|O_EXCL); 238 /* 239 * v_opencount determines the last real close on the vnode. 240 * 241 * If this is the last close, then it checks to see if 242 * the target process has PF_LINGER set in p_pfsflags, 243 * if this is *not* the case, then the process' stop flags 244 * are cleared, and the process is woken up. This is 245 * to help prevent the case where a process has been 246 * told to stop on an event, but then the requesting process 247 * has gone away or forgotten about it. 248 */ 249 p = NULL; 250 if ((ap->a_vp->v_opencount < 2) 251 && ((p = pfs_pfind(pfs->pfs_pid)) != NULL || 252 (p = pfs_zpfind(pfs->pfs_pid)) != NULL) 253 && !(p->p_pfsflags & PF_LINGER)) { 254 spin_lock(&p->p_spin); 255 p->p_stops = 0; 256 p->p_step = 0; 257 spin_unlock(&p->p_spin); 258 wakeup(&p->p_stype); 259 } 260 pfs_pdone(p); 261 break; 262 default: 263 break; 264 } 265 266 return (vop_stdclose(ap)); 267 } 268 269 /* 270 * do an ioctl operation on a pfsnode (vp). 271 * (vp) is not locked on entry or exit. 272 */ 273 static int 274 procfs_ioctl(struct vop_ioctl_args *ap) 275 { 276 struct pfsnode *pfs = VTOPFS(ap->a_vp); 277 struct proc *procp; 278 struct proc *p; 279 int error; 280 int signo; 281 struct procfs_status *psp; 282 unsigned char flags; 283 284 procp = pfs_pfind(pfs->pfs_pid); 285 if (procp == NULL) 286 return ENOTTY; 287 p = curproc; 288 if (p == NULL) { 289 error = EINVAL; 290 goto done; 291 } 292 293 /* Can't trace a process that's currently exec'ing. */ 294 if ((procp->p_flags & P_INEXEC) != 0) { 295 error = EAGAIN; 296 goto done; 297 } 298 if (!CHECKIO(p, procp) || p_trespass(ap->a_cred, procp->p_ucred)) { 299 error = EPERM; 300 goto done; 301 } 302 303 switch (ap->a_command) { 304 case PIOCBIS: 305 spin_lock(&procp->p_spin); 306 procp->p_stops |= *(unsigned int*)ap->a_data; 307 spin_unlock(&procp->p_spin); 308 break; 309 case PIOCBIC: 310 spin_lock(&procp->p_spin); 311 procp->p_stops &= ~*(unsigned int*)ap->a_data; 312 spin_unlock(&procp->p_spin); 313 break; 314 case PIOCSFL: 315 /* 316 * NFLAGS is "non-suser_xxx flags" -- currently, only 317 * PFS_ISUGID ("ignore set u/g id"); 318 */ 319 #define NFLAGS (PF_ISUGID) 320 flags = (unsigned char)*(unsigned int*)ap->a_data; 321 if (flags & NFLAGS && (error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0))) 322 goto done; 323 procp->p_pfsflags = flags; 324 break; 325 case PIOCGFL: 326 *(unsigned int*)ap->a_data = (unsigned int)procp->p_pfsflags; 327 break; 328 case PIOCSTATUS: 329 /* 330 * NOTE: syscall entry deals with stopevents and may run without 331 * the MP lock. 332 */ 333 psp = (struct procfs_status *)ap->a_data; 334 psp->flags = procp->p_pfsflags; 335 psp->events = procp->p_stops; 336 spin_lock(&procp->p_spin); 337 if (procp->p_step) { 338 psp->state = 0; 339 psp->why = procp->p_stype; 340 psp->val = procp->p_xstat; 341 spin_unlock(&procp->p_spin); 342 } else { 343 psp->state = 1; 344 spin_unlock(&procp->p_spin); 345 psp->why = 0; /* Not defined values */ 346 psp->val = 0; /* Not defined values */ 347 } 348 break; 349 case PIOCWAIT: 350 /* 351 * NOTE: syscall entry deals with stopevents and may run without 352 * the MP lock. 353 */ 354 psp = (struct procfs_status *)ap->a_data; 355 spin_lock(&procp->p_spin); 356 while (procp->p_step == 0) { 357 tsleep_interlock(&procp->p_stype, PCATCH); 358 spin_unlock(&procp->p_spin); 359 if (procp->p_stops == 0) { 360 error = EINVAL; 361 goto done; 362 } 363 if (procp->p_flags & P_POSTEXIT) { 364 error = EINVAL; 365 goto done; 366 } 367 if (procp->p_flags & P_INEXEC) { 368 error = EAGAIN; 369 goto done; 370 } 371 error = tsleep(&procp->p_stype, PCATCH | PINTERLOCKED, 372 "piocwait", 0); 373 if (error) 374 goto done; 375 spin_lock(&procp->p_spin); 376 } 377 spin_unlock(&procp->p_spin); 378 psp->state = 1; /* It stopped */ 379 psp->flags = procp->p_pfsflags; 380 psp->events = procp->p_stops; 381 psp->why = procp->p_stype; /* why it stopped */ 382 psp->val = procp->p_xstat; /* any extra info */ 383 break; 384 case PIOCCONT: /* Restart a proc */ 385 /* 386 * NOTE: syscall entry deals with stopevents and may run without 387 * the MP lock. However, the caller is presumably interlocked 388 * by having waited. 389 */ 390 if (procp->p_step == 0) { 391 error = EINVAL; /* Can only start a stopped process */ 392 goto done; 393 } 394 if ((signo = *(int*)ap->a_data) != 0) { 395 if (signo >= NSIG || signo <= 0) { 396 error = EINVAL; 397 goto done; 398 } 399 ksignal(procp, signo); 400 } 401 procp->p_step = 0; 402 wakeup(&procp->p_step); 403 break; 404 default: 405 error = ENOTTY; 406 goto done; 407 } 408 error = 0; 409 done: 410 pfs_pdone(procp); 411 return 0; 412 } 413 414 /* 415 * do block mapping for pfsnode (vp). 416 * since we don't use the buffer cache 417 * for procfs this function should never 418 * be called. in any case, it's not clear 419 * what part of the kernel ever makes use 420 * of this function. for sanity, this is the 421 * usual no-op bmap, although returning 422 * (EIO) would be a reasonable alternative. 423 * 424 * XXX mmap assumes buffer cache operation 425 * 426 * procfs_bmap(struct vnode *a_vp, off_t a_loffset, 427 * off_t *a_doffsetp, int *a_runp, int *a_runb) 428 */ 429 static int 430 procfs_bmap(struct vop_bmap_args *ap) 431 { 432 if (ap->a_doffsetp != NULL) 433 *ap->a_doffsetp = ap->a_loffset; 434 if (ap->a_runp != NULL) 435 *ap->a_runp = 0; 436 if (ap->a_runb != NULL) 437 *ap->a_runb = 0; 438 return (0); 439 } 440 441 /* 442 * procfs_inactive is called when the pfsnode 443 * is vrele'd and the reference count goes 444 * to zero. (vp) will be on the vnode free 445 * list, so to get it back vget() must be 446 * used. 447 * 448 * (vp) is locked on entry, but must be unlocked on exit. 449 * 450 * procfs_inactive(struct vnode *a_vp) 451 */ 452 static int 453 procfs_inactive(struct vop_inactive_args *ap) 454 { 455 struct pfsnode *pfs = VTOPFS(ap->a_vp); 456 457 if (pfs->pfs_pid & PFS_DEAD) 458 vrecycle(ap->a_vp); 459 return (0); 460 } 461 462 /* 463 * _reclaim is called when getnewvnode() 464 * wants to make use of an entry on the vnode 465 * free list. at this time the filesystem needs 466 * to free any private data and remove the node 467 * from any private lists. 468 * 469 * procfs_reclaim(struct vnode *a_vp) 470 */ 471 static int 472 procfs_reclaim(struct vop_reclaim_args *ap) 473 { 474 return (procfs_freevp(ap->a_vp)); 475 } 476 477 /* 478 * _print is used for debugging. 479 * just print a readable description 480 * of (vp). 481 * 482 * procfs_print(struct vnode *a_vp) 483 */ 484 static int 485 procfs_print(struct vop_print_args *ap) 486 { 487 struct pfsnode *pfs = VTOPFS(ap->a_vp); 488 489 kprintf("tag VT_PROCFS, type %d, pid %ld, mode %x, flags %lx\n", 490 pfs->pfs_type, (long)pfs->pfs_pid, pfs->pfs_mode, pfs->pfs_flags); 491 return (0); 492 } 493 494 /* 495 * generic entry point for unsupported operations 496 */ 497 static int 498 procfs_badop(struct vop_generic_args *ap) 499 { 500 return (EIO); 501 } 502 503 /* 504 * Invent attributes for pfsnode (vp) and store 505 * them in (vap). 506 * Directories lengths are returned as zero since 507 * any real length would require the genuine size 508 * to be computed, and nothing cares anyway. 509 * 510 * this is relatively minimal for procfs. 511 * 512 * procfs_getattr(struct vnode *a_vp, struct vattr *a_vap) 513 */ 514 static int 515 procfs_getattr(struct vop_getattr_args *ap) 516 { 517 struct pfsnode *pfs = VTOPFS(ap->a_vp); 518 struct vattr *vap = ap->a_vap; 519 struct proc *procp; 520 int error; 521 522 /* 523 * First make sure that the process and its credentials 524 * still exist. 525 */ 526 switch (pfs->pfs_type) { 527 case Proot: 528 case Pcurproc: 529 procp = NULL; 530 break; 531 default: 532 procp = pfs_pfind(pfs->pfs_pid); 533 if (procp == NULL || procp->p_ucred == NULL) { 534 error = ENOENT; 535 goto done; 536 } 537 break; 538 } 539 540 error = 0; 541 542 /* start by zeroing out the attributes */ 543 VATTR_NULL(vap); 544 545 /* next do all the common fields */ 546 vap->va_type = ap->a_vp->v_type; 547 vap->va_mode = pfs->pfs_mode; 548 vap->va_fileid = pfs->pfs_fileno; 549 vap->va_flags = 0; 550 vap->va_blocksize = PAGE_SIZE; 551 vap->va_bytes = vap->va_size = 0; 552 vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0]; 553 554 /* 555 * Make all times be current TOD. 556 * It would be possible to get the process start 557 * time from the p_stat structure, but there's 558 * no "file creation" time stamp anyway, and the 559 * p_stat structure is not addressible if u. gets 560 * swapped out for that process. 561 */ 562 nanotime(&vap->va_ctime); 563 vap->va_atime = vap->va_mtime = vap->va_ctime; 564 565 /* 566 * If the process has exercised some setuid or setgid 567 * privilege, then rip away read/write permission so 568 * that only root can gain access. 569 */ 570 switch (pfs->pfs_type) { 571 case Pctl: 572 case Pregs: 573 case Pfpregs: 574 case Pdbregs: 575 case Pmem: 576 if (procp->p_flags & P_SUGID) { 577 vap->va_mode &= ~((VREAD|VWRITE)| 578 ((VREAD|VWRITE)>>3)| 579 ((VREAD|VWRITE)>>6)); 580 } 581 break; 582 default: 583 break; 584 } 585 586 /* 587 * now do the object specific fields 588 * 589 * The size could be set from struct reg, but it's hardly 590 * worth the trouble, and it puts some (potentially) machine 591 * dependent data into this machine-independent code. If it 592 * becomes important then this function should break out into 593 * a per-file stat function in the corresponding .c file. 594 */ 595 596 vap->va_nlink = 1; 597 if (procp) { 598 if (procp->p_ucred) { 599 vap->va_uid = procp->p_ucred->cr_uid; 600 vap->va_gid = procp->p_ucred->cr_gid; 601 } else { 602 vap->va_uid = -1; 603 vap->va_gid = -1; 604 } 605 } 606 607 switch (pfs->pfs_type) { 608 case Proot: 609 /* 610 * Set nlink to 1 to tell fts(3) we don't actually know. 611 */ 612 vap->va_nlink = 1; 613 vap->va_uid = 0; 614 vap->va_gid = 0; 615 vap->va_size = vap->va_bytes = DEV_BSIZE; 616 break; 617 618 case Pcurproc: { 619 char buf[16]; /* should be enough */ 620 621 vap->va_uid = 0; 622 vap->va_gid = 0; 623 vap->va_size = ksnprintf(buf, sizeof(buf), 624 "%ld", (long)curproc->p_pid); 625 vap->va_bytes = vap->va_size; 626 break; 627 } 628 629 case Pproc: 630 vap->va_nlink = nproc_targets; 631 vap->va_size = vap->va_bytes = DEV_BSIZE; 632 break; 633 634 case Pfile: { 635 char *fullpath, *freepath; 636 637 if (procp->p_textnch.ncp) { 638 struct nchandle nch; 639 640 cache_copy(&procp->p_textnch, &nch); 641 error = cache_fullpath(procp, &nch, NULL, 642 &fullpath, &freepath, 0); 643 cache_drop(&nch); 644 } else { 645 error = EINVAL; 646 } 647 648 if (error == 0) { 649 vap->va_size = strlen(fullpath); 650 kfree(freepath, M_TEMP); 651 } else { 652 vap->va_size = sizeof("unknown") - 1; 653 error = 0; 654 } 655 vap->va_bytes = vap->va_size; 656 break; 657 } 658 659 case Pmem: 660 /* 661 * If we denied owner access earlier, then we have to 662 * change the owner to root - otherwise 'ps' and friends 663 * will break even though they are setgid kmem. *SIGH* 664 */ 665 if (procp->p_flags & P_SUGID) 666 vap->va_uid = 0; 667 else if (procp->p_ucred) 668 vap->va_uid = procp->p_ucred->cr_uid; 669 else 670 vap->va_uid = -1; 671 break; 672 673 case Pregs: 674 vap->va_bytes = vap->va_size = sizeof(struct reg); 675 break; 676 677 case Pfpregs: 678 vap->va_bytes = vap->va_size = sizeof(struct fpreg); 679 break; 680 681 case Pdbregs: 682 vap->va_bytes = vap->va_size = sizeof(struct dbreg); 683 break; 684 685 case Ptype: 686 case Pmap: 687 case Pctl: 688 case Pstatus: 689 case Pnote: 690 case Pnotepg: 691 case Pcmdline: 692 case Prlimit: 693 break; 694 695 default: 696 panic("procfs_getattr"); 697 } 698 done: 699 pfs_pdone(procp); 700 return (error); 701 } 702 703 /* 704 * procfs_setattr(struct vnode *a_vp, struct vattr *a_vap, 705 * struct ucred *a_cred) 706 */ 707 static int 708 procfs_setattr(struct vop_setattr_args *ap) 709 { 710 if (ap->a_vap->va_flags != VNOVAL) 711 return (EOPNOTSUPP); 712 713 /* 714 * just fake out attribute setting 715 * it's not good to generate an error 716 * return, otherwise things like creat() 717 * will fail when they try to set the 718 * file length to 0. worse, this means 719 * that echo $note > /proc/$pid/note will fail. 720 */ 721 722 return (0); 723 } 724 725 /* 726 * implement access checking. 727 * 728 * procfs_access(struct vnode *a_vp, int a_mode, struct ucred *a_cred) 729 */ 730 static int 731 procfs_access(struct vop_access_args *ap) 732 { 733 struct vattr vattr; 734 int error; 735 736 error = VOP_GETATTR(ap->a_vp, &vattr); 737 if (!error) 738 error = vop_helper_access(ap, vattr.va_uid, vattr.va_gid, 739 vattr.va_mode, 0); 740 return (error); 741 } 742 743 /* 744 * lookup. this is incredibly complicated in the general case, however 745 * for most pseudo-filesystems very little needs to be done. 746 * 747 * procfs_lookup(struct vnode *a_dvp, struct vnode **a_vpp, 748 * struct componentname *a_cnp) 749 */ 750 static int 751 procfs_lookup(struct vop_old_lookup_args *ap) 752 { 753 struct componentname *cnp = ap->a_cnp; 754 struct vnode **vpp = ap->a_vpp; 755 struct vnode *dvp = ap->a_dvp; 756 char *pname = cnp->cn_nameptr; 757 /* struct proc *curp = cnp->cn_proc; */ 758 struct proc_target *pt; 759 pid_t pid; 760 struct pfsnode *pfs; 761 struct proc *p; 762 struct lwp *lp; 763 int i; 764 int error; 765 766 *vpp = NULL; 767 768 if (cnp->cn_nameiop == NAMEI_DELETE || cnp->cn_nameiop == NAMEI_RENAME) 769 return (EROFS); 770 771 p = NULL; 772 error = 0; 773 if (cnp->cn_namelen == 1 && *pname == '.') { 774 *vpp = dvp; 775 vref(*vpp); 776 goto out; 777 } 778 779 pfs = VTOPFS(dvp); 780 switch (pfs->pfs_type) { 781 case Proot: 782 if (cnp->cn_flags & CNP_ISDOTDOT) 783 return (EIO); 784 785 if (CNEQ(cnp, "curproc", 7)) { 786 error = procfs_allocvp(dvp->v_mount, vpp, 0, Pcurproc); 787 goto out; 788 } 789 790 pid = atopid(pname, cnp->cn_namelen); 791 if (pid == NO_PID) 792 break; 793 794 p = pfs_pfind(pid); 795 if (p == NULL) 796 break; 797 798 if (!PRISON_CHECK(ap->a_cnp->cn_cred, p->p_ucred)) 799 break; 800 801 if (ps_showallprocs == 0 && ap->a_cnp->cn_cred->cr_uid != 0 && 802 ap->a_cnp->cn_cred->cr_uid != p->p_ucred->cr_uid) 803 break; 804 805 error = procfs_allocvp(dvp->v_mount, vpp, pid, Pproc); 806 goto out; 807 808 case Pproc: 809 if (cnp->cn_flags & CNP_ISDOTDOT) { 810 error = procfs_root(dvp->v_mount, vpp); 811 goto out; 812 } 813 814 p = pfs_pfind(pfs->pfs_pid); 815 if (p == NULL) 816 break; 817 /* XXX lwp */ 818 lp = FIRST_LWP_IN_PROC(p); 819 820 if (!PRISON_CHECK(ap->a_cnp->cn_cred, p->p_ucred)) 821 break; 822 823 if (ps_showallprocs == 0 && ap->a_cnp->cn_cred->cr_uid != 0 && 824 ap->a_cnp->cn_cred->cr_uid != p->p_ucred->cr_uid) 825 break; 826 827 for (pt = proc_targets, i = 0; i < nproc_targets; pt++, i++) { 828 if (cnp->cn_namelen == pt->pt_namlen && 829 bcmp(pt->pt_name, pname, cnp->cn_namelen) == 0 && 830 (pt->pt_valid == NULL || (*pt->pt_valid)(lp))) 831 goto found; 832 } 833 break; 834 found: 835 error = procfs_allocvp(dvp->v_mount, vpp, pfs->pfs_pid, 836 pt->pt_pfstype); 837 goto out; 838 839 default: 840 error = ENOTDIR; 841 goto out; 842 } 843 if (cnp->cn_nameiop == NAMEI_LOOKUP) 844 error = ENOENT; 845 else 846 error = EROFS; 847 /* 848 * If no error occured *vpp will hold a referenced locked vnode. 849 * dvp was passed to us locked and *vpp must be returned locked. 850 * If *vpp != dvp then we should unlock dvp if (1) this is not the 851 * last component or (2) CNP_LOCKPARENT is not set. 852 */ 853 out: 854 if (error == 0 && *vpp != dvp) { 855 if ((cnp->cn_flags & CNP_LOCKPARENT) == 0) { 856 cnp->cn_flags |= CNP_PDIRUNLOCK; 857 vn_unlock(dvp); 858 } 859 } 860 pfs_pdone(p); 861 return (error); 862 } 863 864 /* 865 * Does this process have a text file? 866 */ 867 int 868 procfs_validfile(struct lwp *lp) 869 { 870 return (procfs_findtextvp(lp->lwp_proc) != NULLVP); 871 } 872 873 /* 874 * readdir() returns directory entries from pfsnode (vp). 875 * 876 * We generate just one directory entry at a time, as it would probably 877 * not pay off to buffer several entries locally to save uiomove calls. 878 * 879 * procfs_readdir(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred, 880 * int *a_eofflag, int *a_ncookies, off_t **a_cookies) 881 */ 882 static int 883 procfs_readdir(struct vop_readdir_args *ap) 884 { 885 struct pfsnode *pfs; 886 int error; 887 888 if (ap->a_uio->uio_offset < 0 || ap->a_uio->uio_offset > INT_MAX) 889 return (EINVAL); 890 if ((error = vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY)) != 0) 891 return (error); 892 pfs = VTOPFS(ap->a_vp); 893 894 switch (pfs->pfs_type) { 895 case Pproc: 896 /* 897 * this is for the process-specific sub-directories. 898 * all that is needed to is copy out all the entries 899 * from the procent[] table (top of this file). 900 */ 901 error = procfs_readdir_proc(ap); 902 break; 903 case Proot: 904 /* 905 * this is for the root of the procfs filesystem 906 * what is needed is a special entry for "curproc" 907 * followed by an entry for each process on allproc 908 */ 909 error = procfs_readdir_root(ap); 910 break; 911 default: 912 error = ENOTDIR; 913 break; 914 } 915 916 vn_unlock(ap->a_vp); 917 return (error); 918 } 919 920 static int 921 procfs_readdir_proc(struct vop_readdir_args *ap) 922 { 923 struct pfsnode *pfs; 924 int error, i, retval; 925 struct proc *p; 926 struct lwp *lp; 927 struct proc_target *pt; 928 struct uio *uio = ap->a_uio; 929 930 pfs = VTOPFS(ap->a_vp); 931 p = pfs_pfind(pfs->pfs_pid); 932 if (p == NULL) 933 return(0); 934 if (!PRISON_CHECK(ap->a_cred, p->p_ucred)) { 935 error = 0; 936 goto done; 937 } 938 /* XXX lwp, not MPSAFE */ 939 lp = FIRST_LWP_IN_PROC(p); 940 941 error = 0; 942 i = (int)uio->uio_offset; 943 if (i < 0) { 944 error = EINVAL; 945 goto done; 946 } 947 948 for (pt = &proc_targets[i]; 949 !error && uio->uio_resid > 0 && i < nproc_targets; pt++, i++) { 950 if (pt->pt_valid && (*pt->pt_valid)(lp) == 0) 951 continue; 952 953 retval = vop_write_dirent(&error, uio, 954 PROCFS_FILENO(pfs->pfs_pid, pt->pt_pfstype), pt->pt_type, 955 pt->pt_namlen, pt->pt_name); 956 if (retval) 957 break; 958 } 959 960 uio->uio_offset = (off_t)i; 961 error = 0; 962 done: 963 pfs_pdone(p); 964 return error; 965 } 966 967 struct procfs_readdir_root_info { 968 int error; 969 int i; 970 int pcnt; 971 struct uio *uio; 972 struct ucred *cred; 973 }; 974 975 static int procfs_readdir_root_callback(struct proc *p, void *data); 976 977 static int 978 procfs_readdir_root(struct vop_readdir_args *ap) 979 { 980 struct procfs_readdir_root_info info; 981 struct uio *uio = ap->a_uio; 982 int res; 983 984 res = 0; 985 info.error = 0; 986 info.i = (int)uio->uio_offset; 987 988 if (info.i < 0) 989 return (EINVAL); 990 991 info.pcnt = 0; 992 info.uio = uio; 993 info.cred = ap->a_cred; 994 while (info.pcnt < 3) { 995 res = procfs_readdir_root_callback(NULL, &info); 996 if (res < 0) 997 break; 998 } 999 if (res >= 0) 1000 allproc_scan(procfs_readdir_root_callback, &info); 1001 uio->uio_offset = (off_t)info.i; 1002 1003 return (info.error); 1004 } 1005 1006 static int 1007 procfs_readdir_root_callback(struct proc *p, void *data) 1008 { 1009 struct procfs_readdir_root_info *info = data; 1010 struct uio *uio; 1011 int retval; 1012 ino_t d_ino; 1013 const char *d_name; 1014 char d_name_pid[20]; 1015 size_t d_namlen; 1016 uint8_t d_type; 1017 1018 uio = info->uio; 1019 1020 if (uio->uio_resid <= 0 || info->error) 1021 return(-1); 1022 1023 switch (info->pcnt) { 1024 case 0: /* `.' */ 1025 d_ino = PROCFS_FILENO(0, Proot); 1026 d_name = "."; 1027 d_namlen = 1; 1028 d_type = DT_DIR; 1029 break; 1030 case 1: /* `..' */ 1031 d_ino = PROCFS_FILENO(0, Proot); 1032 d_name = ".."; 1033 d_namlen = 2; 1034 d_type = DT_DIR; 1035 break; 1036 1037 case 2: 1038 d_ino = PROCFS_FILENO(0, Pcurproc); 1039 d_namlen = 7; 1040 d_name = "curproc"; 1041 d_type = DT_LNK; 1042 break; 1043 1044 1045 default: 1046 if (!PRISON_CHECK(info->cred, p->p_ucred)) 1047 return(0); 1048 if (ps_showallprocs == 0 && 1049 info->cred->cr_uid != 0 && 1050 info->cred->cr_uid != p->p_ucred->cr_uid) { 1051 return(0); 1052 } 1053 1054 /* 1055 * Skip entries we have already returned (optimization) 1056 */ 1057 if (info->pcnt < info->i) { 1058 ++info->pcnt; 1059 return(0); 1060 } 1061 1062 d_ino = PROCFS_FILENO(p->p_pid, Pproc); 1063 d_namlen = ksnprintf(d_name_pid, sizeof(d_name_pid), 1064 "%ld", (long)p->p_pid); 1065 d_name = d_name_pid; 1066 d_type = DT_DIR; 1067 break; 1068 } 1069 1070 /* 1071 * Skip entries we have already returned (optimization) 1072 */ 1073 if (info->pcnt < info->i) { 1074 ++info->pcnt; 1075 return(0); 1076 } 1077 1078 retval = vop_write_dirent(&info->error, uio, 1079 d_ino, d_type, d_namlen, d_name); 1080 if (retval) 1081 return(-1); 1082 ++info->pcnt; 1083 ++info->i; 1084 return(0); 1085 } 1086 1087 /* 1088 * readlink reads the link of `curproc' or `file' 1089 */ 1090 static int 1091 procfs_readlink(struct vop_readlink_args *ap) 1092 { 1093 char buf[16]; /* should be enough */ 1094 struct proc *procp; 1095 struct vnode *vp = ap->a_vp; 1096 struct pfsnode *pfs = VTOPFS(vp); 1097 char *fullpath, *freepath; 1098 int error, len; 1099 1100 switch (pfs->pfs_type) { 1101 case Pcurproc: 1102 if (pfs->pfs_fileno != PROCFS_FILENO(0, Pcurproc)) 1103 return (EINVAL); 1104 1105 len = ksnprintf(buf, sizeof(buf), "%ld", (long)curproc->p_pid); 1106 1107 return (uiomove(buf, len, ap->a_uio)); 1108 /* 1109 * There _should_ be no way for an entire process to disappear 1110 * from under us... 1111 */ 1112 case Pfile: 1113 procp = pfs_pfind(pfs->pfs_pid); 1114 if (procp == NULL || procp->p_ucred == NULL) { 1115 kprintf("procfs_readlink: pid %d disappeared\n", 1116 pfs->pfs_pid); 1117 pfs_pdone(procp); 1118 return (uiomove("unknown", sizeof("unknown") - 1, 1119 ap->a_uio)); 1120 } 1121 if (procp->p_textnch.ncp) { 1122 struct nchandle nch; 1123 1124 cache_copy(&procp->p_textnch, &nch); 1125 error = cache_fullpath(procp, &nch, NULL, 1126 &fullpath, &freepath, 0); 1127 cache_drop(&nch); 1128 } else { 1129 error = EINVAL; 1130 } 1131 1132 if (error != 0) { 1133 pfs_pdone(procp); 1134 return (uiomove("unknown", sizeof("unknown") - 1, 1135 ap->a_uio)); 1136 } 1137 error = uiomove(fullpath, strlen(fullpath), ap->a_uio); 1138 kfree(freepath, M_TEMP); 1139 pfs_pdone(procp); 1140 return (error); 1141 default: 1142 return (EINVAL); 1143 } 1144 } 1145 1146 /* 1147 * convert decimal ascii to pid_t 1148 */ 1149 static pid_t 1150 atopid(const char *b, u_int len) 1151 { 1152 pid_t p = 0; 1153 1154 while (len--) { 1155 char c = *b++; 1156 if (c < '0' || c > '9') 1157 return (NO_PID); 1158 p = 10 * p + (c - '0'); 1159 if (p > PID_MAX) 1160 return (NO_PID); 1161 } 1162 1163 return (p); 1164 } 1165 1166