1/* $NetBSD: procfs_vfsops.c,v 1.95 2016/11/03 03:53:32 pgoyette 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 1.95 2016/11/03 03:53:32 pgoyette Exp $");
80
81#if defined(_KERNEL_OPT)
82#include "opt_compat_netbsd.h"
83#endif
84
85#include <sys/param.h>
86#include <sys/time.h>
87#include <sys/kernel.h>
88#include <sys/systm.h>
89#include <sys/sysctl.h>
90#include <sys/proc.h>
91#include <sys/buf.h>
92#include <sys/syslog.h>
93#include <sys/mount.h>
94#include <sys/dirent.h>
95#include <sys/signalvar.h>
96#include <sys/vnode.h>
97#include <sys/file.h>
98#include <sys/filedesc.h>
99#include <sys/kauth.h>
100#include <sys/module.h>
101
102#include <miscfs/genfs/genfs.h>
103
104#include <miscfs/procfs/procfs.h>
105
106#include <uvm/uvm_extern.h> /* for PAGE_SIZE */
107
108MODULE(MODULE_CLASS_VFS, procfs, "ptrace_common");
109
110VFS_PROTOS(procfs);
111
112static struct sysctllog *procfs_sysctl_log;
113
114static kauth_listener_t procfs_listener;
115
116/*
117 * VFS Operations.
118 *
119 * mount system call
120 */
121/* ARGSUSED */
122int
123procfs_mount(
124 struct mount *mp,
125 const char *path,
126 void *data,
127 size_t *data_len)
128{
129 struct lwp *l = curlwp;
130 struct procfsmount *pmnt;
131 struct procfs_args *args = data;
132 int error;
133
134 if (args == NULL)
135 return EINVAL;
136
137 if (UIO_MX & (UIO_MX-1)) {
138 log(LOG_ERR, "procfs: invalid directory entry size");
139 return (EINVAL);
140 }
141
142 if (mp->mnt_flag & MNT_GETARGS) {
143 if (*data_len < sizeof *args)
144 return EINVAL;
145
146 pmnt = VFSTOPROC(mp);
147 if (pmnt == NULL)
148 return EIO;
149 args->version = PROCFS_ARGSVERSION;
150 args->flags = pmnt->pmnt_flags;
151 *data_len = sizeof *args;
152 return 0;
153 }
154
155 if (mp->mnt_flag & MNT_UPDATE)
156 return (EOPNOTSUPP);
157
158 if (*data_len >= sizeof *args && args->version != PROCFS_ARGSVERSION)
159 return EINVAL;
160
161 pmnt = kmem_zalloc(sizeof(struct procfsmount), KM_SLEEP);
162
163 mp->mnt_stat.f_namemax = PROCFS_MAXNAMLEN;
164 mp->mnt_flag |= MNT_LOCAL;
165 mp->mnt_data = pmnt;
166 vfs_getnewfsid(mp);
167
168 error = set_statvfs_info(path, UIO_USERSPACE, "procfs", UIO_SYSSPACE,
169 mp->mnt_op->vfs_name, mp, l);
170 pmnt->pmnt_exechook = exechook_establish(procfs_revoke_vnodes, mp);
171 if (*data_len >= sizeof *args)
172 pmnt->pmnt_flags = args->flags;
173 else
174 pmnt->pmnt_flags = 0;
175
176 mp->mnt_iflag |= IMNT_MPSAFE;
177 return error;
178}
179
180/*
181 * unmount system call
182 */
183int
184procfs_unmount(struct mount *mp, int mntflags)
185{
186 int error;
187 int flags = 0;
188
189 if (mntflags & MNT_FORCE)
190 flags |= FORCECLOSE;
191
192 if ((error = vflush(mp, 0, flags)) != 0)
193 return (error);
194
195 exechook_disestablish(VFSTOPROC(mp)->pmnt_exechook);
196
197 kmem_free(mp->mnt_data, sizeof(struct procfsmount));
198 mp->mnt_data = NULL;
199
200 return 0;
201}
202
203int
204procfs_root(struct mount *mp, struct vnode **vpp)
205{
206 int error;
207
208 error = procfs_allocvp(mp, vpp, 0, PFSroot, -1);
209 if (error == 0) {
210 error = vn_lock(*vpp, LK_EXCLUSIVE);
211 if (error != 0) {
212 vrele(*vpp);
213 *vpp = NULL;
214 }
215 }
216
217 return error;
218}
219
220/* ARGSUSED */
221int
222procfs_start(struct mount *mp, int flags)
223{
224
225 return (0);
226}
227
228/*
229 * Get file system statistics.
230 */
231int
232procfs_statvfs(struct mount *mp, struct statvfs *sbp)
233{
234
235 genfs_statvfs(mp, sbp);
236
237 sbp->f_bsize = PAGE_SIZE;
238 sbp->f_frsize = PAGE_SIZE;
239 sbp->f_iosize = PAGE_SIZE;
240 sbp->f_blocks = 1;
241 sbp->f_files = maxproc; /* approx */
242 sbp->f_ffree = maxproc - nprocs; /* approx */
243 sbp->f_favail = maxproc - nprocs; /* approx */
244
245 return (0);
246}
247
248/*ARGSUSED*/
249int
250procfs_sync(
251 struct mount *mp,
252 int waitfor,
253 kauth_cred_t uc)
254{
255
256 return (0);
257}
258
259/*ARGSUSED*/
260int
261procfs_vget(struct mount *mp, ino_t ino,
262 struct vnode **vpp)
263{
264 return (EOPNOTSUPP);
265}
266
267int
268procfs_loadvnode(struct mount *mp, struct vnode *vp,
269 const void *key, size_t key_len, const void **new_key)
270{
271 int error;
272 struct pfskey pfskey;
273 struct pfsnode *pfs;
274
275 KASSERT(key_len == sizeof(pfskey));
276 memcpy(&pfskey, key, key_len);
277
278 pfs = kmem_alloc(sizeof(*pfs), KM_SLEEP);
279 pfs->pfs_pid = pfskey.pk_pid;
280 pfs->pfs_type = pfskey.pk_type;
281 pfs->pfs_fd = pfskey.pk_fd;
282 pfs->pfs_vnode = vp;
283 pfs->pfs_flags = 0;
284 pfs->pfs_fileno =
285 PROCFS_FILENO(pfs->pfs_pid, pfs->pfs_type, pfs->pfs_fd);
286 vp->v_tag = VT_PROCFS;
287 vp->v_op = procfs_vnodeop_p;
288 vp->v_data = pfs;
289
290 switch (pfs->pfs_type) {
291 case PFSroot: /* /proc = dr-xr-xr-x */
292 vp->v_vflag |= VV_ROOT;
293 /*FALLTHROUGH*/
294 case PFSproc: /* /proc/N = dr-xr-xr-x */
295 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
296 vp->v_type = VDIR;
297 break;
298
299 case PFStask: /* /proc/N/task = dr-xr-xr-x */
300 if (pfs->pfs_fd == -1) {
301 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|
302 S_IROTH|S_IXOTH;
303 vp->v_type = VDIR;
304 break;
305 }
306 /*FALLTHROUGH*/
307 case PFScurproc: /* /proc/curproc = lr-xr-xr-x */
308 case PFSself: /* /proc/self = lr-xr-xr-x */
309 case PFScwd: /* /proc/N/cwd = lr-xr-xr-x */
310 case PFSchroot: /* /proc/N/chroot = lr-xr-xr-x */
311 case PFSexe: /* /proc/N/exe = lr-xr-xr-x */
312 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
313 vp->v_type = VLNK;
314 break;
315
316 case PFSfd:
317 if (pfs->pfs_fd == -1) { /* /proc/N/fd = dr-x------ */
318 pfs->pfs_mode = S_IRUSR|S_IXUSR;
319 vp->v_type = VDIR;
320 } else { /* /proc/N/fd/M = [ps-]rw------- */
321 file_t *fp;
322 vnode_t *vxp;
323 struct proc *p;
324
325 mutex_enter(proc_lock);
326 p = proc_find(pfs->pfs_pid);
327 mutex_exit(proc_lock);
328 if (p == NULL) {
329 error = ENOENT;
330 goto bad;
331 }
332 KASSERT(rw_read_held(&p->p_reflock));
333 if ((fp = fd_getfile2(p, pfs->pfs_fd)) == NULL) {
334 error = EBADF;
335 goto bad;
336 }
337
338 pfs->pfs_mode = S_IRUSR|S_IWUSR;
339 switch (fp->f_type) {
340 case DTYPE_VNODE:
341 vxp = fp->f_vnode;
342
343 /*
344 * We make symlinks for directories
345 * to avoid cycles.
346 */
347 if (vxp->v_type == VDIR)
348 goto symlink;
349 vp->v_type = vxp->v_type;
350 break;
351 case DTYPE_PIPE:
352 vp->v_type = VFIFO;
353 break;
354 case DTYPE_SOCKET:
355 vp->v_type = VSOCK;
356 break;
357 case DTYPE_KQUEUE:
358 case DTYPE_MISC:
359 case DTYPE_SEM:
360 symlink:
361 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|
362 S_IXGRP|S_IROTH|S_IXOTH;
363 vp->v_type = VLNK;
364 break;
365 default:
366 error = EOPNOTSUPP;
367 closef(fp);
368 goto bad;
369 }
370 closef(fp);
371 }
372 break;
373
374 case PFSfile: /* /proc/N/file = -rw------- */
375 case PFSmem: /* /proc/N/mem = -rw------- */
376 case PFSregs: /* /proc/N/regs = -rw------- */
377 case PFSfpregs: /* /proc/N/fpregs = -rw------- */
378 pfs->pfs_mode = S_IRUSR|S_IWUSR;
379 vp->v_type = VREG;
380 break;
381
382 case PFSctl: /* /proc/N/ctl = --w------ */
383 case PFSnote: /* /proc/N/note = --w------ */
384 case PFSnotepg: /* /proc/N/notepg = --w------ */
385 pfs->pfs_mode = S_IWUSR;
386 vp->v_type = VREG;
387 break;
388
389 case PFSmap: /* /proc/N/map = -r--r--r-- */
390 case PFSmaps: /* /proc/N/maps = -r--r--r-- */
391 case PFSstatus: /* /proc/N/status = -r--r--r-- */
392 case PFSstat: /* /proc/N/stat = -r--r--r-- */
393 case PFScmdline: /* /proc/N/cmdline = -r--r--r-- */
394 case PFSemul: /* /proc/N/emul = -r--r--r-- */
395 case PFSmeminfo: /* /proc/meminfo = -r--r--r-- */
396 case PFScpustat: /* /proc/stat = -r--r--r-- */
397 case PFSdevices: /* /proc/devices = -r--r--r-- */
398 case PFScpuinfo: /* /proc/cpuinfo = -r--r--r-- */
399 case PFSuptime: /* /proc/uptime = -r--r--r-- */
400 case PFSmounts: /* /proc/mounts = -r--r--r-- */
401 case PFSloadavg: /* /proc/loadavg = -r--r--r-- */
402 case PFSstatm: /* /proc/N/statm = -r--r--r-- */
403 case PFSversion: /* /proc/version = -r--r--r-- */
404 pfs->pfs_mode = S_IRUSR|S_IRGRP|S_IROTH;
405 vp->v_type = VREG;
406 break;
407
408#ifdef __HAVE_PROCFS_MACHDEP
409 PROCFS_MACHDEP_NODETYPE_CASES
410 procfs_machdep_allocvp(vp);
411 break;
412#endif
413
414 default:
415 panic("procfs_allocvp");
416 }
417
418 uvm_vnp_setsize(vp, 0);
419 *new_key = &pfs->pfs_key;
420
421 return 0;
422
423bad:
424 vp->v_tag =VT_NON;
425 vp->v_type = VNON;
426 vp->v_op = NULL;
427 vp->v_data = NULL;
428 kmem_free(pfs, sizeof(*pfs));
429 return error;
430}
431
432void
433procfs_init(void)
434{
435
436}
437
438void
439procfs_reinit(void)
440{
441
442}
443
444void
445procfs_done(void)
446{
447
448}
449
450extern const struct vnodeopv_desc procfs_vnodeop_opv_desc;
451
452const struct vnodeopv_desc * const procfs_vnodeopv_descs[] = {
453 &procfs_vnodeop_opv_desc,
454 NULL,
455};
456
457struct vfsops procfs_vfsops = {
458 .vfs_name = MOUNT_PROCFS,
459 .vfs_min_mount_data = sizeof (struct procfs_args),
460 .vfs_mount = procfs_mount,
461 .vfs_start = procfs_start,
462 .vfs_unmount = procfs_unmount,
463 .vfs_root = procfs_root,
464 .vfs_quotactl = (void *)eopnotsupp,
465 .vfs_statvfs = procfs_statvfs,
466 .vfs_sync = procfs_sync,
467 .vfs_vget = procfs_vget,
468 .vfs_loadvnode = procfs_loadvnode,
469 .vfs_fhtovp = (void *)eopnotsupp,
470 .vfs_vptofh = (void *)eopnotsupp,
471 .vfs_init = procfs_init,
472 .vfs_reinit = procfs_reinit,
473 .vfs_done = procfs_done,
474 .vfs_snapshot = (void *)eopnotsupp,
475 .vfs_extattrctl = vfs_stdextattrctl,
476 .vfs_suspendctl = (void *)eopnotsupp,
477 .vfs_renamelock_enter = genfs_renamelock_enter,
478 .vfs_renamelock_exit = genfs_renamelock_exit,
479 .vfs_fsync = (void *)eopnotsupp,
480 .vfs_opv_descs = procfs_vnodeopv_descs
481};
482
483static int
484procfs_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
485 void *arg0, void *arg1, void *arg2, void *arg3)
486{
487 struct proc *p;
488 struct pfsnode *pfs;
489 enum kauth_process_req req;
490 int result;
491
492 result = KAUTH_RESULT_DEFER;
493 p = arg0;
494 pfs = arg1;
495 req = (enum kauth_process_req)(unsigned long)arg2;
496
497 if (action != KAUTH_PROCESS_PROCFS)
498 return result;
499
500 /* Privileged; let secmodel handle that. */
501 if (req == KAUTH_REQ_PROCESS_PROCFS_CTL)
502 return result;
503
504 switch (pfs->pfs_type) {
505 case PFSregs:
506 case PFSfpregs:
507 case PFSmem:
508 if (kauth_cred_getuid(cred) != kauth_cred_getuid(p->p_cred) ||
509 ISSET(p->p_flag, PK_SUGID))
510 break;
511
512 /*FALLTHROUGH*/
513 default:
514 result = KAUTH_RESULT_ALLOW;
515 break;
516 }
517
518 return result;
519}
520
521
522static int
523procfs_modcmd(modcmd_t cmd, void *arg)
524{
525 int error;
526
527 switch (cmd) {
528 case MODULE_CMD_INIT:
529 error = vfs_attach(&procfs_vfsops);
530 if (error != 0)
531 break;
532 sysctl_createv(&procfs_sysctl_log, 0, NULL, NULL,
533 CTLFLAG_PERMANENT,
534 CTLTYPE_NODE, "procfs",
535 SYSCTL_DESCR("Process file system"),
536 NULL, 0, NULL, 0,
537 CTL_VFS, 12, CTL_EOL);
538 /*
539 * XXX the "12" above could be dynamic, thereby eliminating
540 * one more instance of the "number to vfs" mapping problem,
541 * but "12" is the order as taken from sys/mount.h
542 */
543
544 procfs_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS,
545 procfs_listener_cb, NULL);
546
547 break;
548 case MODULE_CMD_FINI:
549 error = vfs_detach(&procfs_vfsops);
550 if (error != 0)
551 break;
552 sysctl_teardown(&procfs_sysctl_log);
553 kauth_unlisten_scope(procfs_listener);
554 break;
555 default:
556 error = ENOTTY;
557 break;
558 }
559
560 return (error);
561}
562