sysctlfs.c revision 1.3 1 /* $NetBSD: sysctlfs.c,v 1.3 2007/08/10 08:13:11 pooka Exp $ */
2
3 /*
4 * Copyright (c) 2006, 2007 Antti Kantee. All Rights Reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 /*
29 * sysctlfs: mount sysctls as a file system tree. Supports query and
30 * modify of nodes in the sysctl namespace in addition to namespace
31 * traversal.
32 */
33
34 #include <sys/cdefs.h>
35 #ifndef lint
36 __RCSID("$NetBSD: sysctlfs.c,v 1.3 2007/08/10 08:13:11 pooka Exp $");
37 #endif /* !lint */
38
39 #include <sys/types.h>
40 #include <sys/sysctl.h>
41
42 #include <assert.h>
43 #include <err.h>
44 #include <errno.h>
45 #include <mntopts.h>
46 #include <paths.h>
47 #include <puffs.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51 #include <util.h>
52
53 PUFFSOP_PROTOS(sysctlfs)
54
55 struct sfsnode {
56 int sysctl_flags;
57 ino_t myid;
58 };
59
60 #define SFSPATH_DOTDOT 0
61 #define SFSPATH_NORMAL 1
62
63 #define N_HIERARCHY 10
64 typedef int SfsName[N_HIERARCHY];
65
66 struct sfsfid {
67 int len;
68 SfsName path;
69 };
70
71 static struct sfsnode rn;
72 static SfsName sname_root;
73 static struct timespec fstime;
74
75 static ino_t nextid = 3;
76 static mode_t fileperms;
77 static uid_t fileuid;
78 static gid_t filegid;
79
80 #define ISADIR(a) ((SYSCTL_TYPE(a->sysctl_flags) == CTLTYPE_NODE))
81 #define SFS_MAXFILE 8192
82 #define SFS_NODEPERDIR 128
83
84 static int sysctlfs_domount(struct puffs_usermount *);
85
86 /*
87 * build paths. doesn't support rename (but neither does the fs)
88 */
89 static int
90 sysctlfs_pathbuild(struct puffs_usermount *pu,
91 const struct puffs_pathobj *parent, const struct puffs_pathobj *comp,
92 size_t offset, struct puffs_pathobj *res)
93 {
94 SfsName *sname;
95 size_t clen;
96
97 assert(parent->po_len < N_HIERARCHY); /* code uses +1 */
98
99 sname = malloc(sizeof(SfsName));
100 assert(sname != NULL);
101
102 clen = parent->po_len;
103 if (comp->po_len == SFSPATH_DOTDOT) {
104 assert(clen != 0);
105 clen--;
106 }
107
108 memcpy(sname, parent->po_path, clen * sizeof(int));
109
110 res->po_path = sname;
111 res->po_len = clen;
112
113 return 0;
114 }
115
116 static int
117 sysctlfs_pathtransform(struct puffs_usermount *pu,
118 const struct puffs_pathobj *p, const const struct puffs_cn *pcn,
119 struct puffs_pathobj *res)
120 {
121
122 res->po_path = NULL;
123 /*
124 * XXX: overload. prevents us from doing rename, but the fs
125 * (and sysctl(3)) doesn't support it, so no biggie
126 */
127 if (PCNISDOTDOT(pcn)) {
128 res->po_len = SFSPATH_DOTDOT;
129 }else {
130 res->po_len = SFSPATH_NORMAL;
131 }
132
133 return 0;
134 }
135
136 static int
137 sysctlfs_pathcmp(struct puffs_usermount *pu, struct puffs_pathobj *po1,
138 struct puffs_pathobj *po2, size_t clen, int checkprefix)
139 {
140
141 if (memcmp(po1->po_path, po2->po_path, clen * sizeof(int)) == 0)
142 return 0;
143 return 1;
144 }
145
146 static void
147 sysctlfs_pathfree(struct puffs_usermount *pu, struct puffs_pathobj *po)
148 {
149
150 free(po->po_path);
151 }
152
153 static struct puffs_node *
154 getnode(struct puffs_usermount *pu, struct puffs_pathobj *po, int nodetype)
155 {
156 struct sysctlnode sn[SFS_NODEPERDIR];
157 struct sysctlnode qnode;
158 struct puffs_node *pn;
159 struct sfsnode *sfs;
160 SfsName myname, *sname;
161 size_t sl;
162 int i;
163
164 /*
165 * Check if we need to create a new in-memory node or if we
166 * already have one for this path. Shortcut for the rootnode.
167 * Also, memcmp against zero-length would be quite true always.
168 */
169 if (po->po_len == 0)
170 pn = puffs_getroot(pu);
171 else
172 pn = puffs_pn_nodewalk(pu, puffs_path_walkcmp, po);
173
174 if (pn == NULL) {
175 /*
176 * don't know nodetype? query...
177 *
178 * XXX1: nothing really guarantees 0 is an invalid nodetype
179 * XXX2: is there really no easier way of doing this? we
180 * know the whole mib path
181 */
182 if (!nodetype) {
183 sname = po->po_path;
184 memcpy(myname, po->po_path, po->po_len * sizeof(int));
185
186 memset(&qnode, 0, sizeof(qnode));
187 qnode.sysctl_flags = SYSCTL_VERSION;
188 myname[po->po_len-1] = CTL_QUERY;
189
190 sl = sizeof(sn);
191 if (sysctl(myname, po->po_len, sn, &sl,
192 &qnode, sizeof(qnode)) == -1)
193 abort();
194
195 for (i = 0; i < sl / sizeof(struct sysctlnode); i++) {
196 if (sn[i].sysctl_num==(*sname)[po->po_len-1]) {
197 nodetype = sn[i].sysctl_flags;
198 break;
199 }
200 }
201 if (!nodetype)
202 return NULL;
203 }
204
205 sfs = emalloc(sizeof(struct sfsnode));
206 sfs->sysctl_flags = nodetype;
207 sfs->myid = nextid++;
208
209 pn = puffs_pn_new(pu, sfs);
210 assert(pn);
211 }
212
213 return pn;
214 }
215
216 int
217 main(int argc, char *argv[])
218 {
219 struct puffs_usermount *pu;
220 struct puffs_ops *pops;
221 mntoptparse_t mp;
222 int mntflags, pflags, lflags;
223 int ch;
224
225 setprogname(argv[0]);
226
227 if (argc < 2)
228 errx(1, "usage: %s sysctlfs [-o mntopts]mountpath",
229 getprogname());
230
231 mntflags = pflags = lflags = 0;
232 while ((ch = getopt(argc, argv, "o:s")) != -1) {
233 switch (ch) {
234 case 'o':
235 mp = getmntopts(optarg, puffsmopts, &mntflags, &pflags);
236 if (mp == NULL)
237 err(1, "getmntopts");
238 freemntopts(mp);
239 break;
240 case 's':
241 lflags = PUFFSLOOP_NODAEMON;
242 break;
243 }
244 }
245 argv += optind;
246 argc -= optind;
247 pflags |= PUFFS_FLAG_BUILDPATH | PUFFS_KFLAG_NOCACHE;
248
249 if (pflags & PUFFS_FLAG_OPDUMP)
250 lflags |= PUFFSLOOP_NODAEMON;
251
252 if (argc != 2)
253 errx(1, "usage: %s [-o mntopts]mountpath", getprogname());
254
255 PUFFSOP_INIT(pops);
256
257 PUFFSOP_SETFSNOP(pops, unmount);
258 PUFFSOP_SETFSNOP(pops, sync);
259 PUFFSOP_SETFSNOP(pops, statvfs);
260 PUFFSOP_SET(pops, sysctlfs, fs, nodetofh);
261 PUFFSOP_SET(pops, sysctlfs, fs, fhtonode);
262
263 PUFFSOP_SET(pops, sysctlfs, node, lookup);
264 PUFFSOP_SET(pops, sysctlfs, node, getattr);
265 PUFFSOP_SET(pops, sysctlfs, node, setattr);
266 PUFFSOP_SET(pops, sysctlfs, node, readdir);
267 PUFFSOP_SET(pops, sysctlfs, node, read);
268 PUFFSOP_SET(pops, sysctlfs, node, write);
269 PUFFSOP_SET(pops, puffs_genfs, node, reclaim);
270
271 pu = puffs_init(pops, _PATH_PUFFS, "sysctlfs", NULL, pflags);
272 if (pu == NULL)
273 err(1, "puffs_init");
274
275 puffs_set_pathbuild(pu, sysctlfs_pathbuild);
276 puffs_set_pathtransform(pu, sysctlfs_pathtransform);
277 puffs_set_pathcmp(pu, sysctlfs_pathcmp);
278 puffs_set_pathfree(pu, sysctlfs_pathfree);
279
280 puffs_setfhsize(pu, sizeof(struct sfsfid), PUFFS_FHFLAG_NFSV3);
281
282 if (sysctlfs_domount(pu) != 0)
283 errx(1, "domount");
284
285 if (puffs_mount(pu, argv[1], mntflags, puffs_getroot(pu)) == -1)
286 err(1, "puffs_mount");
287
288 if (puffs_mainloop(pu, lflags) == -1)
289 err(1, "mainloop");
290
291 return 0;
292 }
293
294 static int
295 sysctlfs_domount(struct puffs_usermount *pu)
296 {
297 struct puffs_pathobj *po_root;
298 struct puffs_node *pn_root;
299 struct timeval tv_now;
300
301 rn.myid = 2;
302 rn.sysctl_flags = CTLTYPE_NODE;
303
304 gettimeofday(&tv_now, NULL);
305 TIMEVAL_TO_TIMESPEC(&tv_now, &fstime);
306
307 pn_root = puffs_pn_new(pu, &rn);
308 assert(pn_root != NULL);
309 puffs_setroot(pu, pn_root);
310
311 po_root = puffs_getrootpathobj(pu);
312 po_root->po_path = &sname_root;
313 po_root->po_len = 0;
314
315 fileuid = geteuid();
316 filegid = getegid();
317
318 if (fileuid == 0)
319 fileperms = 0755;
320 else
321 fileperms = 0555;
322
323 return 0;
324 }
325
326 int
327 sysctlfs_fs_fhtonode(struct puffs_cc *pcc, void *fid, size_t fidsize,
328 struct puffs_newinfo *pni)
329 {
330 struct puffs_pathobj po;
331 struct puffs_node *pn;
332 struct sfsnode *sfs;
333 struct sfsfid *sfid;
334
335 sfid = fid;
336
337 po.po_len = sfid->len;
338 po.po_path = &sfid->path;
339
340 pn = getnode(puffs_cc_getusermount(pcc), &po, 0);
341 if (pn == NULL)
342 return EINVAL;
343 sfs = pn->pn_data;
344
345 puffs_newinfo_setcookie(pni, pn);
346 if (ISADIR(sfs))
347 puffs_newinfo_setvtype(pni, VDIR);
348 else
349 puffs_newinfo_setvtype(pni, VREG);
350
351 return 0;
352 }
353
354 int
355 sysctlfs_fs_nodetofh(struct puffs_cc *pcc, void *cookie,
356 void *fid, size_t *fidsize)
357 {
358 struct puffs_node *pn = cookie;
359 struct sfsfid *sfid;
360
361 sfid = fid;
362 sfid->len = PNPLEN(pn);
363 memcpy(&sfid->path, PNPATH(pn), sfid->len * sizeof(int));
364
365 return 0;
366 }
367
368 static void
369 doprint(struct sfsnode *sfs, struct puffs_pathobj *po,
370 char *buf, size_t bufsize)
371 {
372 size_t sz;
373
374 assert(!ISADIR(sfs));
375
376 memset(buf, 0, bufsize);
377 switch (SYSCTL_TYPE(sfs->sysctl_flags)) {
378 case CTLTYPE_INT: {
379 int i;
380 sz = sizeof(int);
381 if (sysctl(po->po_path, po->po_len, &i, &sz, NULL, 0) == -1)
382 break;
383 snprintf(buf, bufsize, "%d", i);
384 break;
385 }
386 case CTLTYPE_QUAD: {
387 quad_t q;
388 sz = sizeof(q);
389 if (sysctl(po->po_path, po->po_len, &q, &sz, NULL, 0) == -1)
390 break;
391 snprintf(buf, bufsize, "%" PRId64, q);
392 break;
393 }
394 case CTLTYPE_STRUCT:
395 snprintf(buf, bufsize, "CTLTYPE_STRUCT: implement me and "
396 "score a cookie");
397 break;
398 case CTLTYPE_STRING: {
399 sz = bufsize;
400 if (sysctl(po->po_path, po->po_len, buf, &sz, NULL, 0) == -1)
401 break;
402 break;
403 }
404 default:
405 snprintf(buf, bufsize, "invalid sysctl CTLTYPE");
406 break;
407 }
408 }
409
410 static int
411 getlinks(struct sfsnode *sfs, struct puffs_pathobj *po)
412 {
413 struct sysctlnode sn[SFS_NODEPERDIR];
414 struct sysctlnode qnode;
415 SfsName *sname;
416 size_t sl;
417
418 if (!ISADIR(sfs))
419 return 1;
420
421 memset(&qnode, 0, sizeof(qnode));
422 sl = sizeof(sn);
423 qnode.sysctl_flags = SYSCTL_VERSION;
424 sname = po->po_path;
425 (*sname)[po->po_len] = CTL_QUERY;
426
427 if (sysctl(*sname, po->po_len + 1, sn, &sl,
428 &qnode, sizeof(qnode)) == -1)
429 return 0;
430
431 return (sl / sizeof(sn[0])) + 2;
432 }
433
434 static int
435 getsize(struct sfsnode *sfs, struct puffs_pathobj *po)
436 {
437 char buf[SFS_MAXFILE];
438
439 if (ISADIR(sfs))
440 return getlinks(sfs, po) * 16; /* totally arbitrary */
441
442 doprint(sfs, po, buf, sizeof(buf));
443 return strlen(buf) + 1;
444 }
445
446 int
447 sysctlfs_node_lookup(struct puffs_cc *pcc, void *opc, struct puffs_newinfo *pni,
448 const struct puffs_cn *pcn)
449 {
450 struct puffs_usermount *pu = puffs_cc_getusermount(pcc);
451 struct puffs_cn *p2cn = __UNCONST(pcn); /* XXX: fix the interface */
452 struct sysctlnode sn[SFS_NODEPERDIR];
453 struct sysctlnode qnode;
454 struct puffs_node *pn_dir = opc;
455 struct puffs_node *pn_new;
456 struct sfsnode *sfs_dir = pn_dir->pn_data, *sfs_new;
457 SfsName *sname = PCNPATH(pcn);
458 size_t sl;
459 int i, nodetype;
460
461 assert(ISADIR(sfs_dir));
462
463 /*
464 * If we're looking for dotdot, we already have the entire pathname
465 * in sname, courtesy of pathbuild, so we can skip this step.
466 */
467 if (!PCNISDOTDOT(pcn)) {
468 memset(&qnode, 0, sizeof(qnode));
469 sl = SFS_NODEPERDIR * sizeof(struct sysctlnode);
470 qnode.sysctl_flags = SYSCTL_VERSION;
471 (*sname)[PCNPLEN(pcn)] = CTL_QUERY;
472
473 if (sysctl(*sname, PCNPLEN(pcn) + 1, sn, &sl,
474 &qnode, sizeof(qnode)) == -1)
475 return ENOENT;
476
477 for (i = 0; i < sl / sizeof(struct sysctlnode); i++)
478 if (strcmp(sn[i].sysctl_name, pcn->pcn_name) == 0)
479 break;
480 if (i == sl / sizeof(struct sysctlnode))
481 return ENOENT;
482
483 (*sname)[PCNPLEN(pcn)] = sn[i].sysctl_num;
484 p2cn->pcn_po_full.po_len++;
485 nodetype = sn[i].sysctl_flags;
486 } else
487 nodetype = CTLTYPE_NODE;
488
489 pn_new = getnode(pu, &p2cn->pcn_po_full, nodetype);
490 sfs_new = pn_new->pn_data;
491
492 puffs_newinfo_setcookie(pni, pn_new);
493 if (ISADIR(sfs_new))
494 puffs_newinfo_setvtype(pni, VDIR);
495 else
496 puffs_newinfo_setvtype(pni, VREG);
497
498 return 0;
499 }
500
501 int
502 sysctlfs_node_getattr(struct puffs_cc *pcc, void *opc, struct vattr *va,
503 const struct puffs_cred *pcr, const struct puffs_cid *pcid)
504 {
505 struct puffs_node *pn = opc;
506 struct sfsnode *sfs = pn->pn_data;
507
508 memset(va, 0, sizeof(struct vattr));
509
510 if (ISADIR(sfs)) {
511 va->va_type = VDIR;
512 va->va_mode = 0555;
513 } else {
514 va->va_type = VREG;
515 va->va_mode = fileperms;
516 }
517 va->va_uid = fileuid;
518 va->va_gid = filegid;
519 va->va_nlink = getlinks(sfs, &pn->pn_po);
520 va->va_fileid = sfs->myid;
521 va->va_size = getsize(sfs, &pn->pn_po);
522 va->va_gen = 1;
523 va->va_rdev = PUFFS_VNOVAL;
524 va->va_blocksize = 512;
525 va->va_filerev = 1;
526
527 va->va_atime = va->va_mtime = va->va_ctime = va->va_birthtime = fstime;
528
529 return 0;
530 }
531
532 int
533 sysctlfs_node_setattr(struct puffs_cc *pcc, void *opc,
534 const struct vattr *va, const struct puffs_cred *pcr,
535 const struct puffs_cid *pcid)
536 {
537
538 /* dummy, but required for write */
539 /* XXX: we could return EOPNOTSUPP or something */
540 return 0;
541 }
542
543 int
544 sysctlfs_node_readdir(struct puffs_cc *pcc, void *opc, struct dirent *dent,
545 off_t *readoff, size_t *reslen, const struct puffs_cred *pcr,
546 int *eofflag, off_t *cookies, size_t *ncookies)
547 {
548 struct puffs_usermount *pu = puffs_cc_getusermount(pcc);
549 struct sysctlnode sn[SFS_NODEPERDIR];
550 struct sysctlnode qnode;
551 struct puffs_node *pn_dir = opc;
552 struct puffs_node *pn_res;
553 struct puffs_pathobj po;
554 struct sfsnode *sfs_dir = pn_dir->pn_data, *sfs_ent;
555 SfsName *sname;
556 size_t sl;
557 enum vtype vt;
558 ino_t id;
559 int i;
560
561 *ncookies = 0;
562
563 again:
564 if (*readoff == DENT_DOT || *readoff == DENT_DOTDOT) {
565 puffs_gendotdent(&dent, sfs_dir->myid, *readoff, reslen);
566 (*readoff)++;
567 PUFFS_STORE_DCOOKIE(cookies, ncookies, *readoff);
568 goto again;
569 }
570
571 memset(&qnode, 0, sizeof(qnode));
572 sl = SFS_NODEPERDIR * sizeof(struct sysctlnode);
573 qnode.sysctl_flags = SYSCTL_VERSION;
574 sname = PNPATH(pn_dir);
575 (*sname)[PNPLEN(pn_dir)] = CTL_QUERY;
576
577 if (sysctl(*sname, PNPLEN(pn_dir) + 1, sn, &sl,
578 &qnode, sizeof(qnode)) == -1)
579 return ENOENT;
580
581 po.po_path = sname;
582 po.po_len = PNPLEN(pn_dir)+1;
583
584 for (i = DENT_ADJ(*readoff); i < sl / sizeof(struct sysctlnode); i++) {
585 if (SYSCTL_TYPE(sn[i].sysctl_flags) == CTLTYPE_NODE)
586 vt = VDIR;
587 else
588 vt = VREG;
589
590 /*
591 * check if the node exists. if so, give it the real
592 * inode number. otherwise just fake it.
593 */
594 (*sname)[PNPLEN(pn_dir)] = sn[i].sysctl_num;
595 pn_res = puffs_pn_nodewalk(pu, puffs_path_walkcmp, &po);
596 if (pn_res) {
597 sfs_ent = pn_res->pn_data;
598 id = sfs_ent->myid;
599 } else {
600 id = nextid++;
601 }
602
603 if (!puffs_nextdent(&dent, sn[i].sysctl_name, id,
604 puffs_vtype2dt(vt), reslen))
605 return 0;
606
607 (*readoff)++;
608 PUFFS_STORE_DCOOKIE(cookies, ncookies, *readoff);
609 }
610
611 *eofflag = 1;
612 return 0;
613 }
614
615 int
616 sysctlfs_node_read(struct puffs_cc *pcc, void *opc, uint8_t *buf,
617 off_t offset, size_t *resid, const struct puffs_cred *pcr,
618 int ioflag)
619 {
620 char localbuf[SFS_MAXFILE];
621 struct puffs_node *pn = opc;
622 struct sfsnode *sfs = pn->pn_data;
623 int xfer;
624
625 if (ISADIR(sfs))
626 return EISDIR;
627
628 doprint(sfs, &pn->pn_po, localbuf, sizeof(localbuf));
629 xfer = MIN(*resid, strlen(localbuf) - offset);
630
631 if (xfer <= 0)
632 return 0;
633
634 memcpy(buf, localbuf + offset, xfer);
635 *resid -= xfer;
636
637 if (*resid) {
638 buf[xfer] = '\n';
639 (*resid)--;
640 }
641
642 return 0;
643 }
644
645 int
646 sysctlfs_node_write(struct puffs_cc *pcc, void *opc, uint8_t *buf,
647 off_t offset, size_t *resid, const struct puffs_cred *cred,
648 int ioflag)
649 {
650 struct puffs_node *pn = opc;
651 struct sfsnode *sfs = pn->pn_data;
652 long long ll;
653 int i, rv;
654
655 if (puffs_cred_isjuggernaut(cred) == 0)
656 return EACCES;
657
658 if (ISADIR(sfs))
659 return EISDIR;
660
661 if (offset != 0)
662 return EINVAL;
663
664 if (ioflag & PUFFS_IO_APPEND)
665 return EINVAL;
666
667 switch (SYSCTL_TYPE(sfs->sysctl_flags)) {
668 case CTLTYPE_INT:
669 if (sscanf((const char *)buf, "%d", &i) != 1)
670 return EINVAL;
671 rv = sysctl(PNPATH(pn), PNPLEN(pn), NULL, NULL,
672 &i, sizeof(int));
673 break;
674 case CTLTYPE_QUAD:
675 if (sscanf((const char *)buf, "%lld", &ll) != 1)
676 return EINVAL;
677 rv = sysctl(PNPATH(pn), PNPLEN(pn), NULL, NULL,
678 &ll, sizeof(long long));
679 break;
680 case CTLTYPE_STRING:
681 rv = sysctl(PNPATH(pn), PNPLEN(pn), NULL, NULL, buf, *resid);
682 break;
683 default:
684 rv = EINVAL;
685 break;
686 }
687
688 if (rv)
689 return rv;
690
691 *resid = 0;
692 return 0;
693 }
694