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_flag & 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 PRELE(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 = pfind(pfs->pfs_pid)) 252 && !(p->p_pfsflags & PF_LINGER)) { 253 spin_lock(&p->p_spin); 254 p->p_stops = 0; 255 p->p_step = 0; 256 spin_unlock(&p->p_spin); 257 wakeup(&p->p_step); 258 } 259 if (p) 260 PRELE(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 = 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_flag & 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 procp->p_stops |= *(unsigned int*)ap->a_data; 306 break; 307 case PIOCBIC: 308 procp->p_stops &= ~*(unsigned int*)ap->a_data; 309 break; 310 case PIOCSFL: 311 /* 312 * NFLAGS is "non-suser_xxx flags" -- currently, only 313 * PFS_ISUGID ("ignore set u/g id"); 314 */ 315 #define NFLAGS (PF_ISUGID) 316 flags = (unsigned char)*(unsigned int*)ap->a_data; 317 if (flags & NFLAGS && (error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0))) 318 goto done; 319 procp->p_pfsflags = flags; 320 break; 321 case PIOCGFL: 322 *(unsigned int*)ap->a_data = (unsigned int)procp->p_pfsflags; 323 break; 324 case PIOCSTATUS: 325 /* 326 * NOTE: syscall entry deals with stopevents and may run without 327 * the MP lock. 328 */ 329 psp = (struct procfs_status *)ap->a_data; 330 psp->flags = procp->p_pfsflags; 331 psp->events = procp->p_stops; 332 spin_lock(&procp->p_spin); 333 if (procp->p_step) { 334 psp->state = 0; 335 psp->why = procp->p_stype; 336 psp->val = procp->p_xstat; 337 spin_unlock(&procp->p_spin); 338 } else { 339 psp->state = 1; 340 spin_unlock(&procp->p_spin); 341 psp->why = 0; /* Not defined values */ 342 psp->val = 0; /* Not defined values */ 343 } 344 break; 345 case PIOCWAIT: 346 /* 347 * NOTE: syscall entry deals with stopevents and may run without 348 * the MP lock. 349 */ 350 psp = (struct procfs_status *)ap->a_data; 351 spin_lock(&procp->p_spin); 352 while (procp->p_step == 0) { 353 tsleep_interlock(&procp->p_stype, PCATCH); 354 spin_unlock(&procp->p_spin); 355 error = tsleep(&procp->p_stype, PCATCH | PINTERLOCKED, "piocwait", 0); 356 if (error) 357 goto done; 358 spin_lock(&procp->p_spin); 359 } 360 spin_unlock(&procp->p_spin); 361 psp->state = 1; /* It stopped */ 362 psp->flags = procp->p_pfsflags; 363 psp->events = procp->p_stops; 364 psp->why = procp->p_stype; /* why it stopped */ 365 psp->val = procp->p_xstat; /* any extra info */ 366 break; 367 case PIOCCONT: /* Restart a proc */ 368 /* 369 * NOTE: syscall entry deals with stopevents and may run without 370 * the MP lock. However, the caller is presumably interlocked 371 * by having waited. 372 */ 373 if (procp->p_step == 0) { 374 error = EINVAL; /* Can only start a stopped process */ 375 goto done; 376 } 377 if ((signo = *(int*)ap->a_data) != 0) { 378 if (signo >= NSIG || signo <= 0) { 379 error = EINVAL; 380 goto done; 381 } 382 ksignal(procp, signo); 383 } 384 procp->p_step = 0; 385 wakeup(&procp->p_step); 386 break; 387 default: 388 error = ENOTTY; 389 goto done; 390 } 391 error = 0; 392 done: 393 PRELE(procp); 394 return 0; 395 } 396 397 /* 398 * do block mapping for pfsnode (vp). 399 * since we don't use the buffer cache 400 * for procfs this function should never 401 * be called. in any case, it's not clear 402 * what part of the kernel ever makes use 403 * of this function. for sanity, this is the 404 * usual no-op bmap, although returning 405 * (EIO) would be a reasonable alternative. 406 * 407 * XXX mmap assumes buffer cache operation 408 * 409 * procfs_bmap(struct vnode *a_vp, off_t a_loffset, 410 * off_t *a_doffsetp, int *a_runp, int *a_runb) 411 */ 412 static int 413 procfs_bmap(struct vop_bmap_args *ap) 414 { 415 if (ap->a_doffsetp != NULL) 416 *ap->a_doffsetp = ap->a_loffset; 417 if (ap->a_runp != NULL) 418 *ap->a_runp = 0; 419 if (ap->a_runb != NULL) 420 *ap->a_runb = 0; 421 return (0); 422 } 423 424 /* 425 * procfs_inactive is called when the pfsnode 426 * is vrele'd and the reference count goes 427 * to zero. (vp) will be on the vnode free 428 * list, so to get it back vget() must be 429 * used. 430 * 431 * (vp) is locked on entry, but must be unlocked on exit. 432 * 433 * procfs_inactive(struct vnode *a_vp) 434 */ 435 static int 436 procfs_inactive(struct vop_inactive_args *ap) 437 { 438 struct pfsnode *pfs = VTOPFS(ap->a_vp); 439 440 if (pfs->pfs_pid & PFS_DEAD) 441 vrecycle(ap->a_vp); 442 return (0); 443 } 444 445 /* 446 * _reclaim is called when getnewvnode() 447 * wants to make use of an entry on the vnode 448 * free list. at this time the filesystem needs 449 * to free any private data and remove the node 450 * from any private lists. 451 * 452 * procfs_reclaim(struct vnode *a_vp) 453 */ 454 static int 455 procfs_reclaim(struct vop_reclaim_args *ap) 456 { 457 return (procfs_freevp(ap->a_vp)); 458 } 459 460 /* 461 * _print is used for debugging. 462 * just print a readable description 463 * of (vp). 464 * 465 * procfs_print(struct vnode *a_vp) 466 */ 467 static int 468 procfs_print(struct vop_print_args *ap) 469 { 470 struct pfsnode *pfs = VTOPFS(ap->a_vp); 471 472 kprintf("tag VT_PROCFS, type %d, pid %ld, mode %x, flags %lx\n", 473 pfs->pfs_type, (long)pfs->pfs_pid, pfs->pfs_mode, pfs->pfs_flags); 474 return (0); 475 } 476 477 /* 478 * generic entry point for unsupported operations 479 */ 480 static int 481 procfs_badop(struct vop_generic_args *ap) 482 { 483 return (EIO); 484 } 485 486 /* 487 * Invent attributes for pfsnode (vp) and store 488 * them in (vap). 489 * Directories lengths are returned as zero since 490 * any real length would require the genuine size 491 * to be computed, and nothing cares anyway. 492 * 493 * this is relatively minimal for procfs. 494 * 495 * procfs_getattr(struct vnode *a_vp, struct vattr *a_vap) 496 */ 497 static int 498 procfs_getattr(struct vop_getattr_args *ap) 499 { 500 struct pfsnode *pfs = VTOPFS(ap->a_vp); 501 struct vattr *vap = ap->a_vap; 502 struct proc *procp; 503 int error; 504 505 /* 506 * First make sure that the process and its credentials 507 * still exist. 508 */ 509 switch (pfs->pfs_type) { 510 case Proot: 511 case Pcurproc: 512 procp = NULL; 513 break; 514 515 default: 516 procp = pfs_pfind(pfs->pfs_pid); 517 if (procp == NULL || procp->p_ucred == NULL) { 518 error = ENOENT; 519 goto done; 520 } 521 } 522 523 error = 0; 524 525 /* start by zeroing out the attributes */ 526 VATTR_NULL(vap); 527 528 /* next do all the common fields */ 529 vap->va_type = ap->a_vp->v_type; 530 vap->va_mode = pfs->pfs_mode; 531 vap->va_fileid = pfs->pfs_fileno; 532 vap->va_flags = 0; 533 vap->va_blocksize = PAGE_SIZE; 534 vap->va_bytes = vap->va_size = 0; 535 vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0]; 536 537 /* 538 * Make all times be current TOD. 539 * It would be possible to get the process start 540 * time from the p_stat structure, but there's 541 * no "file creation" time stamp anyway, and the 542 * p_stat structure is not addressible if u. gets 543 * swapped out for that process. 544 */ 545 nanotime(&vap->va_ctime); 546 vap->va_atime = vap->va_mtime = vap->va_ctime; 547 548 /* 549 * If the process has exercised some setuid or setgid 550 * privilege, then rip away read/write permission so 551 * that only root can gain access. 552 */ 553 switch (pfs->pfs_type) { 554 case Pctl: 555 case Pregs: 556 case Pfpregs: 557 case Pdbregs: 558 case Pmem: 559 if (procp->p_flag & P_SUGID) 560 vap->va_mode &= ~((VREAD|VWRITE)| 561 ((VREAD|VWRITE)>>3)| 562 ((VREAD|VWRITE)>>6)); 563 break; 564 default: 565 break; 566 } 567 568 /* 569 * now do the object specific fields 570 * 571 * The size could be set from struct reg, but it's hardly 572 * worth the trouble, and it puts some (potentially) machine 573 * dependent data into this machine-independent code. If it 574 * becomes important then this function should break out into 575 * a per-file stat function in the corresponding .c file. 576 */ 577 578 vap->va_nlink = 1; 579 if (procp) { 580 vap->va_uid = procp->p_ucred->cr_uid; 581 vap->va_gid = procp->p_ucred->cr_gid; 582 } 583 584 switch (pfs->pfs_type) { 585 case Proot: 586 /* 587 * Set nlink to 1 to tell fts(3) we don't actually know. 588 */ 589 vap->va_nlink = 1; 590 vap->va_uid = 0; 591 vap->va_gid = 0; 592 vap->va_size = vap->va_bytes = DEV_BSIZE; 593 break; 594 595 case Pcurproc: { 596 char buf[16]; /* should be enough */ 597 vap->va_uid = 0; 598 vap->va_gid = 0; 599 vap->va_size = vap->va_bytes = 600 ksnprintf(buf, sizeof(buf), "%ld", (long)curproc->p_pid); 601 break; 602 } 603 604 case Pproc: 605 vap->va_nlink = nproc_targets; 606 vap->va_size = vap->va_bytes = DEV_BSIZE; 607 break; 608 609 case Pfile: { 610 char *fullpath, *freepath; 611 error = cache_fullpath(procp, &procp->p_textnch, &fullpath, &freepath, 0); 612 if (error == 0) { 613 vap->va_size = strlen(fullpath); 614 kfree(freepath, M_TEMP); 615 } else { 616 vap->va_size = sizeof("unknown") - 1; 617 error = 0; 618 } 619 vap->va_bytes = vap->va_size; 620 break; 621 } 622 623 case Pmem: 624 /* 625 * If we denied owner access earlier, then we have to 626 * change the owner to root - otherwise 'ps' and friends 627 * will break even though they are setgid kmem. *SIGH* 628 */ 629 if (procp->p_flag & P_SUGID) 630 vap->va_uid = 0; 631 else 632 vap->va_uid = procp->p_ucred->cr_uid; 633 break; 634 635 case Pregs: 636 vap->va_bytes = vap->va_size = sizeof(struct reg); 637 break; 638 639 case Pfpregs: 640 vap->va_bytes = vap->va_size = sizeof(struct fpreg); 641 break; 642 643 case Pdbregs: 644 vap->va_bytes = vap->va_size = sizeof(struct dbreg); 645 break; 646 647 case Ptype: 648 case Pmap: 649 case Pctl: 650 case Pstatus: 651 case Pnote: 652 case Pnotepg: 653 case Pcmdline: 654 case Prlimit: 655 break; 656 657 default: 658 panic("procfs_getattr"); 659 } 660 done: 661 if (procp) 662 PRELE(procp); 663 return (error); 664 } 665 666 /* 667 * procfs_setattr(struct vnode *a_vp, struct vattr *a_vap, 668 * struct ucred *a_cred) 669 */ 670 static int 671 procfs_setattr(struct vop_setattr_args *ap) 672 { 673 if (ap->a_vap->va_flags != VNOVAL) 674 return (EOPNOTSUPP); 675 676 /* 677 * just fake out attribute setting 678 * it's not good to generate an error 679 * return, otherwise things like creat() 680 * will fail when they try to set the 681 * file length to 0. worse, this means 682 * that echo $note > /proc/$pid/note will fail. 683 */ 684 685 return (0); 686 } 687 688 /* 689 * implement access checking. 690 * 691 * procfs_access(struct vnode *a_vp, int a_mode, struct ucred *a_cred) 692 */ 693 static int 694 procfs_access(struct vop_access_args *ap) 695 { 696 struct vattr vattr; 697 int error; 698 699 error = VOP_GETATTR(ap->a_vp, &vattr); 700 if (!error) 701 error = vop_helper_access(ap, vattr.va_uid, vattr.va_gid, 702 vattr.va_mode, 0); 703 return (error); 704 } 705 706 /* 707 * lookup. this is incredibly complicated in the general case, however 708 * for most pseudo-filesystems very little needs to be done. 709 * 710 * procfs_lookup(struct vnode *a_dvp, struct vnode **a_vpp, 711 * struct componentname *a_cnp) 712 */ 713 static int 714 procfs_lookup(struct vop_old_lookup_args *ap) 715 { 716 struct componentname *cnp = ap->a_cnp; 717 struct vnode **vpp = ap->a_vpp; 718 struct vnode *dvp = ap->a_dvp; 719 char *pname = cnp->cn_nameptr; 720 /* struct proc *curp = cnp->cn_proc; */ 721 struct proc_target *pt; 722 pid_t pid; 723 struct pfsnode *pfs; 724 struct proc *p; 725 struct lwp *lp; 726 int i; 727 int error; 728 729 *vpp = NULL; 730 731 if (cnp->cn_nameiop == NAMEI_DELETE || cnp->cn_nameiop == NAMEI_RENAME) 732 return (EROFS); 733 734 p = NULL; 735 error = 0; 736 if (cnp->cn_namelen == 1 && *pname == '.') { 737 *vpp = dvp; 738 vref(*vpp); 739 goto out; 740 } 741 742 pfs = VTOPFS(dvp); 743 switch (pfs->pfs_type) { 744 case Proot: 745 if (cnp->cn_flags & CNP_ISDOTDOT) 746 return (EIO); 747 748 if (CNEQ(cnp, "curproc", 7)) { 749 error = procfs_allocvp(dvp->v_mount, vpp, 0, Pcurproc); 750 goto out; 751 } 752 753 pid = atopid(pname, cnp->cn_namelen); 754 if (pid == NO_PID) 755 break; 756 757 p = pfs_pfind(pid); 758 if (p == NULL) 759 break; 760 761 if (!PRISON_CHECK(ap->a_cnp->cn_cred, p->p_ucred)) 762 break; 763 764 if (ps_showallprocs == 0 && ap->a_cnp->cn_cred->cr_uid != 0 && 765 ap->a_cnp->cn_cred->cr_uid != p->p_ucred->cr_uid) 766 break; 767 768 error = procfs_allocvp(dvp->v_mount, vpp, pid, Pproc); 769 goto out; 770 771 case Pproc: 772 if (cnp->cn_flags & CNP_ISDOTDOT) { 773 error = procfs_root(dvp->v_mount, vpp); 774 goto out; 775 } 776 777 p = pfs_pfind(pfs->pfs_pid); 778 if (p == NULL) 779 break; 780 /* XXX lwp */ 781 lp = FIRST_LWP_IN_PROC(p); 782 783 if (!PRISON_CHECK(ap->a_cnp->cn_cred, p->p_ucred)) 784 break; 785 786 if (ps_showallprocs == 0 && ap->a_cnp->cn_cred->cr_uid != 0 && 787 ap->a_cnp->cn_cred->cr_uid != p->p_ucred->cr_uid) 788 break; 789 790 for (pt = proc_targets, i = 0; i < nproc_targets; pt++, i++) { 791 if (cnp->cn_namelen == pt->pt_namlen && 792 bcmp(pt->pt_name, pname, cnp->cn_namelen) == 0 && 793 (pt->pt_valid == NULL || (*pt->pt_valid)(lp))) 794 goto found; 795 } 796 break; 797 found: 798 error = procfs_allocvp(dvp->v_mount, vpp, pfs->pfs_pid, 799 pt->pt_pfstype); 800 goto out; 801 802 default: 803 error = ENOTDIR; 804 goto out; 805 } 806 if (cnp->cn_nameiop == NAMEI_LOOKUP) 807 error = ENOENT; 808 else 809 error = EROFS; 810 /* 811 * If no error occured *vpp will hold a referenced locked vnode. 812 * dvp was passed to us locked and *vpp must be returned locked. 813 * If *vpp != dvp then we should unlock dvp if (1) this is not the 814 * last component or (2) CNP_LOCKPARENT is not set. 815 */ 816 out: 817 if (error == 0 && *vpp != dvp) { 818 if ((cnp->cn_flags & CNP_LOCKPARENT) == 0) { 819 cnp->cn_flags |= CNP_PDIRUNLOCK; 820 vn_unlock(dvp); 821 } 822 } 823 if (p) 824 PRELE(p); 825 return (error); 826 } 827 828 /* 829 * Does this process have a text file? 830 */ 831 int 832 procfs_validfile(struct lwp *lp) 833 { 834 return (procfs_findtextvp(lp->lwp_proc) != NULLVP); 835 } 836 837 /* 838 * readdir() returns directory entries from pfsnode (vp). 839 * 840 * We generate just one directory entry at a time, as it would probably 841 * not pay off to buffer several entries locally to save uiomove calls. 842 * 843 * procfs_readdir(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred, 844 * int *a_eofflag, int *a_ncookies, off_t **a_cookies) 845 */ 846 static int 847 procfs_readdir(struct vop_readdir_args *ap) 848 { 849 struct pfsnode *pfs; 850 int error; 851 852 if (ap->a_uio->uio_offset < 0 || ap->a_uio->uio_offset > INT_MAX) 853 return (EINVAL); 854 if ((error = vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY)) != 0) 855 return (error); 856 pfs = VTOPFS(ap->a_vp); 857 858 switch (pfs->pfs_type) { 859 case Pproc: 860 /* 861 * this is for the process-specific sub-directories. 862 * all that is needed to is copy out all the entries 863 * from the procent[] table (top of this file). 864 */ 865 error = procfs_readdir_proc(ap); 866 break; 867 case Proot: 868 /* 869 * this is for the root of the procfs filesystem 870 * what is needed is a special entry for "curproc" 871 * followed by an entry for each process on allproc 872 */ 873 error = procfs_readdir_root(ap); 874 break; 875 default: 876 error = ENOTDIR; 877 break; 878 } 879 880 vn_unlock(ap->a_vp); 881 return (error); 882 } 883 884 static int 885 procfs_readdir_proc(struct vop_readdir_args *ap) 886 { 887 struct pfsnode *pfs; 888 int error, i, retval; 889 struct proc *p; 890 struct lwp *lp; 891 struct proc_target *pt; 892 struct uio *uio = ap->a_uio; 893 894 pfs = VTOPFS(ap->a_vp); 895 p = pfs_pfind(pfs->pfs_pid); 896 if (p == NULL) 897 return(0); 898 if (!PRISON_CHECK(ap->a_cred, p->p_ucred)) { 899 error = 0; 900 goto done; 901 } 902 /* XXX lwp, not MPSAFE */ 903 lp = FIRST_LWP_IN_PROC(p); 904 905 error = 0; 906 i = (int)uio->uio_offset; 907 if (i < 0) { 908 error = EINVAL; 909 goto done; 910 } 911 912 for (pt = &proc_targets[i]; 913 !error && uio->uio_resid > 0 && i < nproc_targets; pt++, i++) { 914 if (pt->pt_valid && (*pt->pt_valid)(lp) == 0) 915 continue; 916 917 retval = vop_write_dirent(&error, uio, 918 PROCFS_FILENO(pfs->pfs_pid, pt->pt_pfstype), pt->pt_type, 919 pt->pt_namlen, pt->pt_name); 920 if (retval) 921 break; 922 } 923 924 uio->uio_offset = (off_t)i; 925 error = 0; 926 done: 927 PRELE(p); 928 return error; 929 } 930 931 struct procfs_readdir_root_info { 932 int error; 933 int i; 934 int pcnt; 935 struct uio *uio; 936 struct ucred *cred; 937 }; 938 939 static int procfs_readdir_root_callback(struct proc *p, void *data); 940 941 static int 942 procfs_readdir_root(struct vop_readdir_args *ap) 943 { 944 struct procfs_readdir_root_info info; 945 struct uio *uio = ap->a_uio; 946 int res; 947 948 info.error = 0; 949 info.i = (int)uio->uio_offset; 950 951 if (info.i < 0) 952 return (EINVAL); 953 954 info.pcnt = 0; 955 info.uio = uio; 956 info.cred = ap->a_cred; 957 while (info.pcnt < 3) { 958 res = procfs_readdir_root_callback(NULL, &info); 959 if (res < 0) 960 break; 961 } 962 if (res >= 0) 963 allproc_scan(procfs_readdir_root_callback, &info); 964 uio->uio_offset = (off_t)info.i; 965 966 return (info.error); 967 } 968 969 static int 970 procfs_readdir_root_callback(struct proc *p, void *data) 971 { 972 struct procfs_readdir_root_info *info = data; 973 struct uio *uio; 974 int retval; 975 ino_t d_ino; 976 const char *d_name; 977 char d_name_pid[20]; 978 size_t d_namlen; 979 uint8_t d_type; 980 981 uio = info->uio; 982 983 if (uio->uio_resid <= 0 || info->error) 984 return(-1); 985 986 switch (info->pcnt) { 987 case 0: /* `.' */ 988 d_ino = PROCFS_FILENO(0, Proot); 989 d_name = "."; 990 d_namlen = 1; 991 d_type = DT_DIR; 992 break; 993 case 1: /* `..' */ 994 d_ino = PROCFS_FILENO(0, Proot); 995 d_name = ".."; 996 d_namlen = 2; 997 d_type = DT_DIR; 998 break; 999 1000 case 2: 1001 d_ino = PROCFS_FILENO(0, Pcurproc); 1002 d_namlen = 7; 1003 d_name = "curproc"; 1004 d_type = DT_LNK; 1005 break; 1006 1007 1008 default: 1009 if (!PRISON_CHECK(info->cred, p->p_ucred)) 1010 return(0); 1011 if (ps_showallprocs == 0 && 1012 info->cred->cr_uid != 0 && 1013 info->cred->cr_uid != p->p_ucred->cr_uid) { 1014 return(0); 1015 } 1016 1017 /* 1018 * Skip entries we have already returned (optimization) 1019 */ 1020 if (info->pcnt < info->i) { 1021 ++info->pcnt; 1022 return(0); 1023 } 1024 1025 d_ino = PROCFS_FILENO(p->p_pid, Pproc); 1026 d_namlen = ksnprintf(d_name_pid, sizeof(d_name_pid), 1027 "%ld", (long)p->p_pid); 1028 d_name = d_name_pid; 1029 d_type = DT_DIR; 1030 break; 1031 } 1032 1033 /* 1034 * Skip entries we have already returned (optimization) 1035 */ 1036 if (info->pcnt < info->i) { 1037 ++info->pcnt; 1038 return(0); 1039 } 1040 1041 retval = vop_write_dirent(&info->error, uio, 1042 d_ino, d_type, d_namlen, d_name); 1043 if (retval) 1044 return(-1); 1045 ++info->pcnt; 1046 ++info->i; 1047 return(0); 1048 } 1049 1050 /* 1051 * readlink reads the link of `curproc' or `file' 1052 */ 1053 static int 1054 procfs_readlink(struct vop_readlink_args *ap) 1055 { 1056 char buf[16]; /* should be enough */ 1057 struct proc *procp; 1058 struct vnode *vp = ap->a_vp; 1059 struct pfsnode *pfs = VTOPFS(vp); 1060 char *fullpath, *freepath; 1061 int error, len; 1062 1063 switch (pfs->pfs_type) { 1064 case Pcurproc: 1065 if (pfs->pfs_fileno != PROCFS_FILENO(0, Pcurproc)) 1066 return (EINVAL); 1067 1068 len = ksnprintf(buf, sizeof(buf), "%ld", (long)curproc->p_pid); 1069 1070 return (uiomove(buf, len, ap->a_uio)); 1071 /* 1072 * There _should_ be no way for an entire process to disappear 1073 * from under us... 1074 */ 1075 case Pfile: 1076 procp = pfs_pfind(pfs->pfs_pid); 1077 if (procp == NULL || procp->p_ucred == NULL) { 1078 kprintf("procfs_readlink: pid %d disappeared\n", 1079 pfs->pfs_pid); 1080 if (procp) 1081 PRELE(procp); 1082 return (uiomove("unknown", sizeof("unknown") - 1, 1083 ap->a_uio)); 1084 } 1085 error = cache_fullpath(procp, &procp->p_textnch, &fullpath, &freepath, 0); 1086 if (error != 0) { 1087 if (procp) 1088 PRELE(procp); 1089 return (uiomove("unknown", sizeof("unknown") - 1, 1090 ap->a_uio)); 1091 } 1092 error = uiomove(fullpath, strlen(fullpath), ap->a_uio); 1093 kfree(freepath, M_TEMP); 1094 if (procp) 1095 PRELE(procp); 1096 return (error); 1097 default: 1098 return (EINVAL); 1099 } 1100 } 1101 1102 /* 1103 * convert decimal ascii to pid_t 1104 */ 1105 static pid_t 1106 atopid(const char *b, u_int len) 1107 { 1108 pid_t p = 0; 1109 1110 while (len--) { 1111 char c = *b++; 1112 if (c < '0' || c > '9') 1113 return (NO_PID); 1114 p = 10 * p + (c - '0'); 1115 if (p > PID_MAX) 1116 return (NO_PID); 1117 } 1118 1119 return (p); 1120 } 1121 1122