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