sysctlfs.c revision 1.3.2.1 1 /* $NetBSD: sysctlfs.c,v 1.3.2.1 2007/11/06 23:36:33 matt 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 1.3.2.1 2007/11/06 23:36:33 matt 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;
223 int detach;
224 int ch;
225
226 setprogname(argv[0]);
227
228 if (argc < 2)
229 errx(1, "usage: %s sysctlfs [-o mntopts]mountpath",
230 getprogname());
231
232 mntflags = pflags = 0;
233 detach = 1;
234 while ((ch = getopt(argc, argv, "o:s")) != -1) {
235 switch (ch) {
236 case 'o':
237 mp = getmntopts(optarg, puffsmopts, &mntflags, &pflags);
238 if (mp == NULL)
239 err(1, "getmntopts");
240 freemntopts(mp);
241 break;
242 case 's':
243 detach = 0;
244 break;
245 }
246 }
247 argv += optind;
248 argc -= optind;
249 pflags |= PUFFS_FLAG_BUILDPATH | PUFFS_KFLAG_NOCACHE;
250
251 if (pflags & PUFFS_FLAG_OPDUMP)
252 detach = 0;
253
254 if (argc != 2)
255 errx(1, "usage: %s [-o mntopts]mountpath", getprogname());
256
257 PUFFSOP_INIT(pops);
258
259 PUFFSOP_SETFSNOP(pops, unmount);
260 PUFFSOP_SETFSNOP(pops, sync);
261 PUFFSOP_SETFSNOP(pops, statvfs);
262 PUFFSOP_SET(pops, sysctlfs, fs, nodetofh);
263 PUFFSOP_SET(pops, sysctlfs, fs, fhtonode);
264
265 PUFFSOP_SET(pops, sysctlfs, node, lookup);
266 PUFFSOP_SET(pops, sysctlfs, node, getattr);
267 PUFFSOP_SET(pops, sysctlfs, node, setattr);
268 PUFFSOP_SET(pops, sysctlfs, node, readdir);
269 PUFFSOP_SET(pops, sysctlfs, node, read);
270 PUFFSOP_SET(pops, sysctlfs, node, write);
271 PUFFSOP_SET(pops, puffs_genfs, node, reclaim);
272
273 pu = puffs_init(pops, _PATH_PUFFS, "sysctlfs", NULL, pflags);
274 if (pu == NULL)
275 err(1, "puffs_init");
276
277 puffs_set_pathbuild(pu, sysctlfs_pathbuild);
278 puffs_set_pathtransform(pu, sysctlfs_pathtransform);
279 puffs_set_pathcmp(pu, sysctlfs_pathcmp);
280 puffs_set_pathfree(pu, sysctlfs_pathfree);
281
282 puffs_setfhsize(pu, sizeof(struct sfsfid), PUFFS_FHFLAG_NFSV3);
283
284 if (sysctlfs_domount(pu) != 0)
285 errx(1, "domount");
286
287 if (detach)
288 if (daemon(1, 1) == -1)
289 err(1, "daemon");
290
291 if (puffs_mount(pu, argv[1], mntflags, puffs_getroot(pu)) == -1)
292 err(1, "puffs_mount");
293 if (puffs_mainloop(pu) == -1)
294 err(1, "mainloop");
295
296 return 0;
297 }
298
299 static int
300 sysctlfs_domount(struct puffs_usermount *pu)
301 {
302 struct puffs_pathobj *po_root;
303 struct puffs_node *pn_root;
304 struct timeval tv_now;
305
306 rn.myid = 2;
307 rn.sysctl_flags = CTLTYPE_NODE;
308
309 gettimeofday(&tv_now, NULL);
310 TIMEVAL_TO_TIMESPEC(&tv_now, &fstime);
311
312 pn_root = puffs_pn_new(pu, &rn);
313 assert(pn_root != NULL);
314 puffs_setroot(pu, pn_root);
315
316 po_root = puffs_getrootpathobj(pu);
317 po_root->po_path = &sname_root;
318 po_root->po_len = 0;
319
320 fileuid = geteuid();
321 filegid = getegid();
322
323 if (fileuid == 0)
324 fileperms = 0755;
325 else
326 fileperms = 0555;
327
328 return 0;
329 }
330
331 int
332 sysctlfs_fs_fhtonode(struct puffs_cc *pcc, void *fid, size_t fidsize,
333 struct puffs_newinfo *pni)
334 {
335 struct puffs_pathobj po;
336 struct puffs_node *pn;
337 struct sfsnode *sfs;
338 struct sfsfid *sfid;
339
340 sfid = fid;
341
342 po.po_len = sfid->len;
343 po.po_path = &sfid->path;
344
345 pn = getnode(puffs_cc_getusermount(pcc), &po, 0);
346 if (pn == NULL)
347 return EINVAL;
348 sfs = pn->pn_data;
349
350 puffs_newinfo_setcookie(pni, pn);
351 if (ISADIR(sfs))
352 puffs_newinfo_setvtype(pni, VDIR);
353 else
354 puffs_newinfo_setvtype(pni, VREG);
355
356 return 0;
357 }
358
359 int
360 sysctlfs_fs_nodetofh(struct puffs_cc *pcc, void *cookie,
361 void *fid, size_t *fidsize)
362 {
363 struct puffs_node *pn = cookie;
364 struct sfsfid *sfid;
365
366 sfid = fid;
367 sfid->len = PNPLEN(pn);
368 memcpy(&sfid->path, PNPATH(pn), sfid->len * sizeof(int));
369
370 return 0;
371 }
372
373 static void
374 doprint(struct sfsnode *sfs, struct puffs_pathobj *po,
375 char *buf, size_t bufsize)
376 {
377 size_t sz;
378
379 assert(!ISADIR(sfs));
380
381 memset(buf, 0, bufsize);
382 switch (SYSCTL_TYPE(sfs->sysctl_flags)) {
383 case CTLTYPE_INT: {
384 int i;
385 sz = sizeof(int);
386 if (sysctl(po->po_path, po->po_len, &i, &sz, NULL, 0) == -1)
387 break;
388 snprintf(buf, bufsize, "%d", i);
389 break;
390 }
391 case CTLTYPE_QUAD: {
392 quad_t q;
393 sz = sizeof(q);
394 if (sysctl(po->po_path, po->po_len, &q, &sz, NULL, 0) == -1)
395 break;
396 snprintf(buf, bufsize, "%" PRId64, q);
397 break;
398 }
399 case CTLTYPE_STRUCT:
400 snprintf(buf, bufsize, "CTLTYPE_STRUCT: implement me and "
401 "score a cookie");
402 break;
403 case CTLTYPE_STRING: {
404 sz = bufsize;
405 if (sysctl(po->po_path, po->po_len, buf, &sz, NULL, 0) == -1)
406 break;
407 break;
408 }
409 default:
410 snprintf(buf, bufsize, "invalid sysctl CTLTYPE");
411 break;
412 }
413 }
414
415 static int
416 getlinks(struct sfsnode *sfs, struct puffs_pathobj *po)
417 {
418 struct sysctlnode sn[SFS_NODEPERDIR];
419 struct sysctlnode qnode;
420 SfsName *sname;
421 size_t sl;
422
423 if (!ISADIR(sfs))
424 return 1;
425
426 memset(&qnode, 0, sizeof(qnode));
427 sl = sizeof(sn);
428 qnode.sysctl_flags = SYSCTL_VERSION;
429 sname = po->po_path;
430 (*sname)[po->po_len] = CTL_QUERY;
431
432 if (sysctl(*sname, po->po_len + 1, sn, &sl,
433 &qnode, sizeof(qnode)) == -1)
434 return 0;
435
436 return (sl / sizeof(sn[0])) + 2;
437 }
438
439 static int
440 getsize(struct sfsnode *sfs, struct puffs_pathobj *po)
441 {
442 char buf[SFS_MAXFILE];
443
444 if (ISADIR(sfs))
445 return getlinks(sfs, po) * 16; /* totally arbitrary */
446
447 doprint(sfs, po, buf, sizeof(buf));
448 return strlen(buf) + 1;
449 }
450
451 int
452 sysctlfs_node_lookup(struct puffs_cc *pcc, void *opc, struct puffs_newinfo *pni,
453 const struct puffs_cn *pcn)
454 {
455 struct puffs_usermount *pu = puffs_cc_getusermount(pcc);
456 struct puffs_cn *p2cn = __UNCONST(pcn); /* XXX: fix the interface */
457 struct sysctlnode sn[SFS_NODEPERDIR];
458 struct sysctlnode qnode;
459 struct puffs_node *pn_dir = opc;
460 struct puffs_node *pn_new;
461 struct sfsnode *sfs_dir = pn_dir->pn_data, *sfs_new;
462 SfsName *sname = PCNPATH(pcn);
463 size_t sl;
464 int i, nodetype;
465
466 assert(ISADIR(sfs_dir));
467
468 /*
469 * If we're looking for dotdot, we already have the entire pathname
470 * in sname, courtesy of pathbuild, so we can skip this step.
471 */
472 if (!PCNISDOTDOT(pcn)) {
473 memset(&qnode, 0, sizeof(qnode));
474 sl = SFS_NODEPERDIR * sizeof(struct sysctlnode);
475 qnode.sysctl_flags = SYSCTL_VERSION;
476 (*sname)[PCNPLEN(pcn)] = CTL_QUERY;
477
478 if (sysctl(*sname, PCNPLEN(pcn) + 1, sn, &sl,
479 &qnode, sizeof(qnode)) == -1)
480 return ENOENT;
481
482 for (i = 0; i < sl / sizeof(struct sysctlnode); i++)
483 if (strcmp(sn[i].sysctl_name, pcn->pcn_name) == 0)
484 break;
485 if (i == sl / sizeof(struct sysctlnode))
486 return ENOENT;
487
488 (*sname)[PCNPLEN(pcn)] = sn[i].sysctl_num;
489 p2cn->pcn_po_full.po_len++;
490 nodetype = sn[i].sysctl_flags;
491 } else
492 nodetype = CTLTYPE_NODE;
493
494 pn_new = getnode(pu, &p2cn->pcn_po_full, nodetype);
495 sfs_new = pn_new->pn_data;
496
497 puffs_newinfo_setcookie(pni, pn_new);
498 if (ISADIR(sfs_new))
499 puffs_newinfo_setvtype(pni, VDIR);
500 else
501 puffs_newinfo_setvtype(pni, VREG);
502
503 return 0;
504 }
505
506 int
507 sysctlfs_node_getattr(struct puffs_cc *pcc, void *opc, struct vattr *va,
508 const struct puffs_cred *pcr, const struct puffs_cid *pcid)
509 {
510 struct puffs_node *pn = opc;
511 struct sfsnode *sfs = pn->pn_data;
512
513 memset(va, 0, sizeof(struct vattr));
514
515 if (ISADIR(sfs)) {
516 va->va_type = VDIR;
517 va->va_mode = 0555;
518 } else {
519 va->va_type = VREG;
520 va->va_mode = fileperms;
521 }
522 va->va_uid = fileuid;
523 va->va_gid = filegid;
524 va->va_nlink = getlinks(sfs, &pn->pn_po);
525 va->va_fileid = sfs->myid;
526 va->va_size = getsize(sfs, &pn->pn_po);
527 va->va_gen = 1;
528 va->va_rdev = PUFFS_VNOVAL;
529 va->va_blocksize = 512;
530 va->va_filerev = 1;
531
532 va->va_atime = va->va_mtime = va->va_ctime = va->va_birthtime = fstime;
533
534 return 0;
535 }
536
537 int
538 sysctlfs_node_setattr(struct puffs_cc *pcc, void *opc,
539 const struct vattr *va, const struct puffs_cred *pcr,
540 const struct puffs_cid *pcid)
541 {
542
543 /* dummy, but required for write */
544 /* XXX: we could return EOPNOTSUPP or something */
545 return 0;
546 }
547
548 int
549 sysctlfs_node_readdir(struct puffs_cc *pcc, void *opc, struct dirent *dent,
550 off_t *readoff, size_t *reslen, const struct puffs_cred *pcr,
551 int *eofflag, off_t *cookies, size_t *ncookies)
552 {
553 struct puffs_usermount *pu = puffs_cc_getusermount(pcc);
554 struct sysctlnode sn[SFS_NODEPERDIR];
555 struct sysctlnode qnode;
556 struct puffs_node *pn_dir = opc;
557 struct puffs_node *pn_res;
558 struct puffs_pathobj po;
559 struct sfsnode *sfs_dir = pn_dir->pn_data, *sfs_ent;
560 SfsName *sname;
561 size_t sl;
562 enum vtype vt;
563 ino_t id;
564 int i;
565
566 *ncookies = 0;
567
568 again:
569 if (*readoff == DENT_DOT || *readoff == DENT_DOTDOT) {
570 puffs_gendotdent(&dent, sfs_dir->myid, *readoff, reslen);
571 (*readoff)++;
572 PUFFS_STORE_DCOOKIE(cookies, ncookies, *readoff);
573 goto again;
574 }
575
576 memset(&qnode, 0, sizeof(qnode));
577 sl = SFS_NODEPERDIR * sizeof(struct sysctlnode);
578 qnode.sysctl_flags = SYSCTL_VERSION;
579 sname = PNPATH(pn_dir);
580 (*sname)[PNPLEN(pn_dir)] = CTL_QUERY;
581
582 if (sysctl(*sname, PNPLEN(pn_dir) + 1, sn, &sl,
583 &qnode, sizeof(qnode)) == -1)
584 return ENOENT;
585
586 po.po_path = sname;
587 po.po_len = PNPLEN(pn_dir)+1;
588
589 for (i = DENT_ADJ(*readoff); i < sl / sizeof(struct sysctlnode); i++) {
590 if (SYSCTL_TYPE(sn[i].sysctl_flags) == CTLTYPE_NODE)
591 vt = VDIR;
592 else
593 vt = VREG;
594
595 /*
596 * check if the node exists. if so, give it the real
597 * inode number. otherwise just fake it.
598 */
599 (*sname)[PNPLEN(pn_dir)] = sn[i].sysctl_num;
600 pn_res = puffs_pn_nodewalk(pu, puffs_path_walkcmp, &po);
601 if (pn_res) {
602 sfs_ent = pn_res->pn_data;
603 id = sfs_ent->myid;
604 } else {
605 id = nextid++;
606 }
607
608 if (!puffs_nextdent(&dent, sn[i].sysctl_name, id,
609 puffs_vtype2dt(vt), reslen))
610 return 0;
611
612 (*readoff)++;
613 PUFFS_STORE_DCOOKIE(cookies, ncookies, *readoff);
614 }
615
616 *eofflag = 1;
617 return 0;
618 }
619
620 int
621 sysctlfs_node_read(struct puffs_cc *pcc, void *opc, uint8_t *buf,
622 off_t offset, size_t *resid, const struct puffs_cred *pcr,
623 int ioflag)
624 {
625 char localbuf[SFS_MAXFILE];
626 struct puffs_node *pn = opc;
627 struct sfsnode *sfs = pn->pn_data;
628 int xfer;
629
630 if (ISADIR(sfs))
631 return EISDIR;
632
633 doprint(sfs, &pn->pn_po, localbuf, sizeof(localbuf));
634 xfer = MIN(*resid, strlen(localbuf) - offset);
635
636 if (xfer <= 0)
637 return 0;
638
639 memcpy(buf, localbuf + offset, xfer);
640 *resid -= xfer;
641
642 if (*resid) {
643 buf[xfer] = '\n';
644 (*resid)--;
645 }
646
647 return 0;
648 }
649
650 int
651 sysctlfs_node_write(struct puffs_cc *pcc, void *opc, uint8_t *buf,
652 off_t offset, size_t *resid, const struct puffs_cred *cred,
653 int ioflag)
654 {
655 struct puffs_node *pn = opc;
656 struct sfsnode *sfs = pn->pn_data;
657 long long ll;
658 int i, rv;
659
660 if (puffs_cred_isjuggernaut(cred) == 0)
661 return EACCES;
662
663 if (ISADIR(sfs))
664 return EISDIR;
665
666 if (offset != 0)
667 return EINVAL;
668
669 if (ioflag & PUFFS_IO_APPEND)
670 return EINVAL;
671
672 switch (SYSCTL_TYPE(sfs->sysctl_flags)) {
673 case CTLTYPE_INT:
674 if (sscanf((const char *)buf, "%d", &i) != 1)
675 return EINVAL;
676 rv = sysctl(PNPATH(pn), PNPLEN(pn), NULL, NULL,
677 &i, sizeof(int));
678 break;
679 case CTLTYPE_QUAD:
680 if (sscanf((const char *)buf, "%lld", &ll) != 1)
681 return EINVAL;
682 rv = sysctl(PNPATH(pn), PNPLEN(pn), NULL, NULL,
683 &ll, sizeof(long long));
684 break;
685 case CTLTYPE_STRING:
686 rv = sysctl(PNPATH(pn), PNPLEN(pn), NULL, NULL, buf, *resid);
687 break;
688 default:
689 rv = EINVAL;
690 break;
691 }
692
693 if (rv)
694 return rv;
695
696 *resid = 0;
697 return 0;
698 }
699