procfs_vfsops.c revision 1.112
1 /* $NetBSD: procfs_vfsops.c,v 1.112 2024/01/17 10:19:21 hannken Exp $ */ 2 3 /* 4 * Copyright (c) 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Jan-Simon Pendry. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)procfs_vfsops.c 8.7 (Berkeley) 5/10/95 35 */ 36 37 /* 38 * Copyright (c) 1993 Jan-Simon Pendry 39 * 40 * This code is derived from software contributed to Berkeley by 41 * Jan-Simon Pendry. 42 * 43 * Redistribution and use in source and binary forms, with or without 44 * modification, are permitted provided that the following conditions 45 * are met: 46 * 1. Redistributions of source code must retain the above copyright 47 * notice, this list of conditions and the following disclaimer. 48 * 2. Redistributions in binary form must reproduce the above copyright 49 * notice, this list of conditions and the following disclaimer in the 50 * documentation and/or other materials provided with the distribution. 51 * 3. All advertising materials mentioning features or use of this software 52 * must display the following acknowledgement: 53 * This product includes software developed by the University of 54 * California, Berkeley and its contributors. 55 * 4. Neither the name of the University nor the names of its contributors 56 * may be used to endorse or promote products derived from this software 57 * without specific prior written permission. 58 * 59 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 61 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 62 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 63 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 64 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 65 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 69 * SUCH DAMAGE. 70 * 71 * @(#)procfs_vfsops.c 8.7 (Berkeley) 5/10/95 72 */ 73 74 /* 75 * procfs VFS interface 76 */ 77 78 #include <sys/cdefs.h> 79 __KERNEL_RCSID(0, "$NetBSD: procfs_vfsops.c,v 1.112 2024/01/17 10:19:21 hannken Exp $"); 80 81 #if defined(_KERNEL_OPT) 82 #include "opt_compat_netbsd.h" 83 #endif 84 85 #include <sys/param.h> 86 #include <sys/atomic.h> 87 #include <sys/buf.h> 88 #include <sys/dirent.h> 89 #include <sys/file.h> 90 #include <sys/filedesc.h> 91 #include <sys/kauth.h> 92 #include <sys/kernel.h> 93 #include <sys/module.h> 94 #include <sys/mount.h> 95 #include <sys/proc.h> 96 #include <sys/signalvar.h> 97 #include <sys/sysctl.h> 98 #include <sys/syslog.h> 99 #include <sys/systm.h> 100 #include <sys/time.h> 101 #include <sys/vnode.h> 102 103 #include <miscfs/genfs/genfs.h> 104 105 #include <miscfs/procfs/procfs.h> 106 107 #include <uvm/uvm_extern.h> /* for PAGE_SIZE */ 108 109 MODULE(MODULE_CLASS_VFS, procfs, "ptrace_common"); 110 111 VFS_PROTOS(procfs); 112 113 #define PROCFS_HASHSIZE 256 114 115 static kauth_listener_t procfs_listener; 116 LIST_HEAD(hashhead, pfsnode); 117 static u_long procfs_hashmask; 118 static struct hashhead *procfs_hashtab; 119 static kmutex_t procfs_hashlock; 120 121 static struct hashhead * 122 procfs_hashhead(pid_t pid) 123 { 124 125 return &procfs_hashtab[pid & procfs_hashmask]; 126 } 127 128 void 129 procfs_hashrem(struct pfsnode *pfs) 130 { 131 132 mutex_enter(&procfs_hashlock); 133 LIST_REMOVE(pfs, pfs_hash); 134 mutex_exit(&procfs_hashlock); 135 } 136 137 /* 138 * VFS Operations. 139 * 140 * mount system call 141 */ 142 /* ARGSUSED */ 143 int 144 procfs_mount( 145 struct mount *mp, 146 const char *path, 147 void *data, 148 size_t *data_len) 149 { 150 struct lwp *l = curlwp; 151 struct procfsmount *pmnt; 152 struct procfs_args *args = data; 153 int error; 154 155 if (args == NULL) 156 return EINVAL; 157 158 if (UIO_MX & (UIO_MX-1)) { 159 log(LOG_ERR, "procfs: invalid directory entry size"); 160 return (EINVAL); 161 } 162 163 if (mp->mnt_flag & MNT_GETARGS) { 164 if (*data_len < sizeof *args) 165 return EINVAL; 166 167 pmnt = VFSTOPROC(mp); 168 if (pmnt == NULL) 169 return EIO; 170 args->version = PROCFS_ARGSVERSION; 171 args->flags = pmnt->pmnt_flags; 172 *data_len = sizeof *args; 173 return 0; 174 } 175 176 if (mp->mnt_flag & MNT_UPDATE) 177 return (EOPNOTSUPP); 178 179 if (*data_len >= sizeof *args && args->version != PROCFS_ARGSVERSION) 180 return EINVAL; 181 182 pmnt = kmem_zalloc(sizeof(struct procfsmount), KM_SLEEP); 183 184 mp->mnt_stat.f_namemax = PROCFS_MAXNAMLEN; 185 mp->mnt_flag |= MNT_LOCAL; 186 mp->mnt_data = pmnt; 187 vfs_getnewfsid(mp); 188 189 error = set_statvfs_info(path, UIO_USERSPACE, "procfs", UIO_SYSSPACE, 190 mp->mnt_op->vfs_name, mp, l); 191 pmnt->pmnt_exechook = exechook_establish(procfs_revoke_vnodes, mp); 192 if (*data_len >= sizeof *args) 193 pmnt->pmnt_flags = args->flags; 194 else 195 pmnt->pmnt_flags = 0; 196 197 mp->mnt_iflag |= IMNT_MPSAFE | IMNT_SHRLOOKUP; 198 return error; 199 } 200 201 /* 202 * unmount system call 203 */ 204 int 205 procfs_unmount(struct mount *mp, int mntflags) 206 { 207 int error; 208 int flags = 0; 209 210 if (mntflags & MNT_FORCE) 211 flags |= FORCECLOSE; 212 213 if ((error = vflush(mp, 0, flags)) != 0) 214 return (error); 215 216 exechook_disestablish(VFSTOPROC(mp)->pmnt_exechook); 217 218 kmem_free(mp->mnt_data, sizeof(struct procfsmount)); 219 mp->mnt_data = NULL; 220 221 return 0; 222 } 223 224 int 225 procfs_root(struct mount *mp, int lktype, struct vnode **vpp) 226 { 227 int error; 228 229 error = procfs_allocvp(mp, vpp, 0, PFSroot, -1); 230 if (error == 0) { 231 error = vn_lock(*vpp, lktype); 232 if (error != 0) { 233 vrele(*vpp); 234 *vpp = NULL; 235 } 236 } 237 238 return error; 239 } 240 241 /* ARGSUSED */ 242 int 243 procfs_start(struct mount *mp, int flags) 244 { 245 246 return (0); 247 } 248 249 /* 250 * Get file system statistics. 251 */ 252 int 253 procfs_statvfs(struct mount *mp, struct statvfs *sbp) 254 { 255 256 genfs_statvfs(mp, sbp); 257 258 sbp->f_bsize = PAGE_SIZE; 259 sbp->f_frsize = PAGE_SIZE; 260 sbp->f_iosize = PAGE_SIZE; 261 sbp->f_blocks = 1; 262 sbp->f_files = maxproc; /* approx */ 263 sbp->f_ffree = maxproc - atomic_load_relaxed(&nprocs); /* approx */ 264 sbp->f_favail = maxproc - atomic_load_relaxed(&nprocs); /* approx */ 265 266 return (0); 267 } 268 269 /*ARGSUSED*/ 270 int 271 procfs_sync( 272 struct mount *mp, 273 int waitfor, 274 kauth_cred_t uc) 275 { 276 277 return (0); 278 } 279 280 /*ARGSUSED*/ 281 int 282 procfs_vget(struct mount *mp, ino_t ino, int lktype, 283 struct vnode **vpp) 284 { 285 return (EOPNOTSUPP); 286 } 287 288 int 289 procfs_loadvnode(struct mount *mp, struct vnode *vp, 290 const void *key, size_t key_len, const void **new_key) 291 { 292 int error; 293 struct pfskey pfskey; 294 struct pfsnode *pfs; 295 296 KASSERT(key_len == sizeof(pfskey)); 297 memcpy(&pfskey, key, key_len); 298 299 pfs = kmem_alloc(sizeof(*pfs), KM_SLEEP); 300 pfs->pfs_pid = pfskey.pk_pid; 301 pfs->pfs_type = pfskey.pk_type; 302 pfs->pfs_fd = pfskey.pk_fd; 303 pfs->pfs_vnode = vp; 304 pfs->pfs_mount = mp; 305 pfs->pfs_flags = 0; 306 pfs->pfs_fileno = 307 PROCFS_FILENO(pfs->pfs_pid, pfs->pfs_type, pfs->pfs_fd); 308 vp->v_tag = VT_PROCFS; 309 vp->v_op = procfs_vnodeop_p; 310 vp->v_data = pfs; 311 312 switch (pfs->pfs_type) { 313 case PFSroot: /* /proc = dr-xr-xr-x */ 314 vp->v_vflag |= VV_ROOT; 315 /*FALLTHROUGH*/ 316 case PFSproc: /* /proc/N = dr-xr-xr-x */ 317 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 318 vp->v_type = VDIR; 319 break; 320 321 case PFStask: /* /proc/N/task = dr-xr-xr-x */ 322 if (pfs->pfs_fd == -1) { 323 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP| 324 S_IROTH|S_IXOTH; 325 vp->v_type = VDIR; 326 break; 327 } 328 /*FALLTHROUGH*/ 329 case PFScurproc: /* /proc/curproc = lr-xr-xr-x */ 330 case PFSself: /* /proc/self = lr-xr-xr-x */ 331 case PFScwd: /* /proc/N/cwd = lr-xr-xr-x */ 332 case PFSchroot: /* /proc/N/chroot = lr-xr-xr-x */ 333 case PFSexe: /* /proc/N/exe = lr-xr-xr-x */ 334 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 335 vp->v_type = VLNK; 336 break; 337 338 case PFSfd: 339 if (pfs->pfs_fd == -1) { /* /proc/N/fd = dr-x------ */ 340 pfs->pfs_mode = S_IRUSR|S_IXUSR; 341 vp->v_type = VDIR; 342 } else { /* /proc/N/fd/M = [ps-]rw------- */ 343 file_t *fp; 344 vnode_t *vxp; 345 struct proc *p; 346 347 mutex_enter(&proc_lock); 348 p = procfs_proc_find(mp, pfs->pfs_pid); 349 mutex_exit(&proc_lock); 350 if (p == NULL) { 351 error = ENOENT; 352 goto bad; 353 } 354 KASSERT(rw_read_held(&p->p_reflock)); 355 if ((fp = fd_getfile2(p, pfs->pfs_fd)) == NULL) { 356 error = EBADF; 357 goto bad; 358 } 359 360 pfs->pfs_mode = S_IRUSR|S_IWUSR; 361 switch (fp->f_type) { 362 case DTYPE_VNODE: 363 vxp = fp->f_vnode; 364 365 /* 366 * We make symlinks for directories 367 * to avoid cycles. 368 */ 369 if (vxp->v_type == VDIR || 370 procfs_proc_is_linux_compat()) 371 goto symlink; 372 vp->v_type = vxp->v_type; 373 break; 374 case DTYPE_PIPE: 375 vp->v_type = VFIFO; 376 break; 377 case DTYPE_SOCKET: 378 vp->v_type = VSOCK; 379 break; 380 case DTYPE_KQUEUE: 381 case DTYPE_MISC: 382 case DTYPE_SEM: 383 symlink: 384 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP| 385 S_IXGRP|S_IROTH|S_IXOTH; 386 vp->v_type = VLNK; 387 break; 388 default: 389 error = EOPNOTSUPP; 390 closef(fp); 391 goto bad; 392 } 393 closef(fp); 394 } 395 break; 396 397 case PFSfile: /* /proc/N/file = -rw------- */ 398 case PFSmem: /* /proc/N/mem = -rw------- */ 399 case PFSregs: /* /proc/N/regs = -rw------- */ 400 case PFSfpregs: /* /proc/N/fpregs = -rw------- */ 401 pfs->pfs_mode = S_IRUSR|S_IWUSR; 402 vp->v_type = VREG; 403 break; 404 405 case PFSnote: /* /proc/N/note = --w------ */ 406 case PFSnotepg: /* /proc/N/notepg = --w------ */ 407 pfs->pfs_mode = S_IWUSR; 408 vp->v_type = VREG; 409 break; 410 411 case PFSmap: /* /proc/N/map = -r-------- */ 412 case PFSmaps: /* /proc/N/maps = -r-------- */ 413 case PFSauxv: /* /proc/N/auxv = -r-------- */ 414 case PFSenviron: /* /proc/N/environ = -r-------- */ 415 pfs->pfs_mode = S_IRUSR; 416 vp->v_type = VREG; 417 break; 418 419 case PFSstatus: /* /proc/N/status = -r--r--r-- */ 420 case PFSstat: /* /proc/N/stat = -r--r--r-- */ 421 case PFScmdline: /* /proc/N/cmdline = -r--r--r-- */ 422 case PFSemul: /* /proc/N/emul = -r--r--r-- */ 423 case PFSmeminfo: /* /proc/meminfo = -r--r--r-- */ 424 case PFScpustat: /* /proc/stat = -r--r--r-- */ 425 case PFSdevices: /* /proc/devices = -r--r--r-- */ 426 case PFScpuinfo: /* /proc/cpuinfo = -r--r--r-- */ 427 case PFSuptime: /* /proc/uptime = -r--r--r-- */ 428 case PFSmounts: /* /proc/mounts = -r--r--r-- */ 429 case PFSloadavg: /* /proc/loadavg = -r--r--r-- */ 430 case PFSstatm: /* /proc/N/statm = -r--r--r-- */ 431 case PFSversion: /* /proc/version = -r--r--r-- */ 432 case PFSlimit: /* /proc/limit = -r--r--r-- */ 433 pfs->pfs_mode = S_IRUSR|S_IRGRP|S_IROTH; 434 vp->v_type = VREG; 435 break; 436 437 #ifdef __HAVE_PROCFS_MACHDEP 438 PROCFS_MACHDEP_NODETYPE_CASES 439 procfs_machdep_allocvp(vp); 440 break; 441 #endif 442 443 default: 444 panic("procfs_allocvp"); 445 } 446 447 mutex_enter(&procfs_hashlock); 448 LIST_INSERT_HEAD(procfs_hashhead(pfs->pfs_pid), pfs, pfs_hash); 449 mutex_exit(&procfs_hashlock); 450 451 uvm_vnp_setsize(vp, 0); 452 *new_key = &pfs->pfs_key; 453 454 return 0; 455 456 bad: 457 vp->v_tag =VT_NON; 458 vp->v_type = VNON; 459 vp->v_op = NULL; 460 vp->v_data = NULL; 461 kmem_free(pfs, sizeof(*pfs)); 462 return error; 463 } 464 465 void 466 procfs_init(void) 467 { 468 469 } 470 471 void 472 procfs_reinit(void) 473 { 474 475 } 476 477 void 478 procfs_done(void) 479 { 480 481 } 482 483 extern const struct vnodeopv_desc procfs_vnodeop_opv_desc; 484 485 const struct vnodeopv_desc * const procfs_vnodeopv_descs[] = { 486 &procfs_vnodeop_opv_desc, 487 NULL, 488 }; 489 490 struct vfsops procfs_vfsops = { 491 .vfs_name = MOUNT_PROCFS, 492 .vfs_min_mount_data = sizeof (struct procfs_args), 493 .vfs_mount = procfs_mount, 494 .vfs_start = procfs_start, 495 .vfs_unmount = procfs_unmount, 496 .vfs_root = procfs_root, 497 .vfs_quotactl = (void *)eopnotsupp, 498 .vfs_statvfs = procfs_statvfs, 499 .vfs_sync = procfs_sync, 500 .vfs_vget = procfs_vget, 501 .vfs_loadvnode = procfs_loadvnode, 502 .vfs_fhtovp = (void *)eopnotsupp, 503 .vfs_vptofh = (void *)eopnotsupp, 504 .vfs_init = procfs_init, 505 .vfs_reinit = procfs_reinit, 506 .vfs_done = procfs_done, 507 .vfs_snapshot = (void *)eopnotsupp, 508 .vfs_extattrctl = vfs_stdextattrctl, 509 .vfs_suspendctl = genfs_suspendctl, 510 .vfs_renamelock_enter = genfs_renamelock_enter, 511 .vfs_renamelock_exit = genfs_renamelock_exit, 512 .vfs_fsync = (void *)eopnotsupp, 513 .vfs_opv_descs = procfs_vnodeopv_descs 514 }; 515 516 static int 517 procfs_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, 518 void *arg0, void *arg1, void *arg2, void *arg3) 519 { 520 struct proc *p; 521 struct pfsnode *pfs; 522 int result; 523 524 result = KAUTH_RESULT_DEFER; 525 p = arg0; 526 pfs = arg1; 527 528 if (action != KAUTH_PROCESS_PROCFS) 529 return result; 530 531 switch (pfs->pfs_type) { 532 case PFSregs: 533 case PFSfpregs: 534 case PFSmem: 535 if (kauth_cred_getuid(cred) != kauth_cred_getuid(p->p_cred) || 536 ISSET(p->p_flag, PK_SUGID)) 537 break; 538 539 /*FALLTHROUGH*/ 540 default: 541 result = KAUTH_RESULT_ALLOW; 542 break; 543 } 544 545 return result; 546 } 547 548 SYSCTL_SETUP(procfs_sysctl_setup, "procfs sysctl") 549 { 550 551 sysctl_createv(clog, 0, NULL, NULL, 552 CTLFLAG_PERMANENT, 553 CTLTYPE_NODE, "procfs", 554 SYSCTL_DESCR("Process file system"), 555 NULL, 0, NULL, 0, 556 CTL_VFS, 12, CTL_EOL); 557 /* 558 * XXX the "12" above could be dynamic, thereby eliminating 559 * one more instance of the "number to vfs" mapping problem, 560 * but "12" is the order as taken from sys/mount.h 561 */ 562 } 563 564 static int 565 procfs_modcmd(modcmd_t cmd, void *arg) 566 { 567 int error; 568 569 switch (cmd) { 570 case MODULE_CMD_INIT: 571 error = vfs_attach(&procfs_vfsops); 572 if (error != 0) 573 break; 574 575 procfs_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS, 576 procfs_listener_cb, NULL); 577 578 break; 579 case MODULE_CMD_FINI: 580 error = vfs_detach(&procfs_vfsops); 581 if (error != 0) 582 break; 583 kauth_unlisten_scope(procfs_listener); 584 break; 585 default: 586 error = ENOTTY; 587 break; 588 } 589 590 return (error); 591 } 592
Indexes created Mon Sep 29 21:09:56 GMT 2025