1 /*-
2  * Copyright (c) 2005-2006 The FreeBSD Project
3  * All rights reserved.
4  *
5  * Author: Victor Cruceru <soc-victor@freebsd.org>
6  *
7  * Redistribution of this software and documentation and use in source and
8  * binary forms, with or without modification, are permitted provided that
9  * the following conditions are met:
10  *
11  * 1. Redistributions of source code or documentation must retain the above
12  *    copyright notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /*
31  * Host Resources MIB for SNMPd. Implementation for hrFSTable
32  */
33 
34 #include <sys/types.h>
35 #include <sys/param.h>
36 #include <sys/sysctl.h>
37 #include <sys/mount.h>
38 
39 #include <assert.h>
40 #include <err.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <syslog.h>
44 #include <sysexits.h>
45 
46 #include "hostres_snmp.h"
47 #include "hostres_oid.h"
48 #include "hostres_tree.h"
49 
50 /*
51  * File system access enum
52  */
53 enum hrFSAccess {
54 	FS_READ_WRITE = 1,
55 	FS_READ_ONLY  = 2
56 };
57 
58 /* maximum length (according to MIB) for fs_entry::mountPoint */
59 #define	FS_MP_MLEN	(128 + 1)
60 
61 /* maximum length (according to MIB) for fs_entry::remoteMountPoint */
62 #define	FS_RMP_MLEN	(128 + 1)
63 
64 /*
65  * This structure is used to hold a SNMP table entry
66  * for HOST-RESOURCES-MIB's hrFSTable
67  */
68 struct fs_entry {
69 	int32_t		index;
70 	u_char		*mountPoint;
71 	u_char		*remoteMountPoint;
72 	const struct asn_oid *type;
73 	int32_t		access;		/* enum hrFSAccess, see above */
74 	int32_t		bootable;	/* TruthValue */
75 	int32_t		storageIndex;	/* hrStorageTblEntry::index */
76 	u_char		lastFullBackupDate[11];
77 	u_char		lastPartialBackupDate[11];
78 #define	HR_FS_FOUND 0x001
79 	uint32_t	flags;		/* not in mib table, for internal use */
80 	TAILQ_ENTRY(fs_entry) link;
81 };
82 TAILQ_HEAD(fs_tbl, fs_entry);
83 
84 /*
85  * Next structure is used to keep o list of mappings from a specific name
86  * (a_name) to an entry in the hrFSTblEntry. We are trying to keep the same
87  * index for a specific name at least for the duration of one SNMP agent run.
88  */
89 struct fs_map_entry {
90 	int32_t		hrIndex;   /* used for fs_entry::index */
91 	u_char		*a_name;   /* map key same as fs_entry::mountPoint */
92 
93 	/* may be NULL if the respective hrFSTblEntry is (temporally) gone */
94 	struct fs_entry *entry;
95 	STAILQ_ENTRY(fs_map_entry) 	link;
96 };
97 STAILQ_HEAD(fs_map, fs_map_entry);
98 
99 /* head of the list with hrFSTable's entries */
100 static struct fs_tbl fs_tbl = TAILQ_HEAD_INITIALIZER(fs_tbl);
101 
102 /* for consistent table indexing */
103 static struct fs_map fs_map = STAILQ_HEAD_INITIALIZER(fs_map);
104 
105 /* next index available for hrFSTable */
106 static uint32_t	next_fs_index = 1;
107 
108 /* last tick when hrFSTable was updated */
109 static uint64_t fs_tick;
110 
111 /* maximum number of ticks between refreshs */
112 uint32_t fs_tbl_refresh = HR_FS_TBL_REFRESH * 100;
113 
114 /* some constants */
115 static const struct asn_oid OIDX_hrFSBerkeleyFFS_c = OIDX_hrFSBerkeleyFFS;
116 static const struct asn_oid OIDX_hrFSiso9660_c = OIDX_hrFSiso9660;
117 static const struct asn_oid OIDX_hrFSNFS_c = OIDX_hrFSNFS;
118 static const struct asn_oid OIDX_hrFSLinuxExt2_c = OIDX_hrFSLinuxExt2;
119 static const struct asn_oid OIDX_hrFSOther_c = OIDX_hrFSOther;
120 static const struct asn_oid OIDX_hrFSFAT32_c = OIDX_hrFSFAT32;
121 static const struct asn_oid OIDX_hrFSNTFS_c = OIDX_hrFSNTFS;
122 static const struct asn_oid OIDX_hrFSNetware_c = OIDX_hrFSNetware;
123 static const struct asn_oid OIDX_hrFSHPFS_c = OIDX_hrFSHPFS;
124 static const struct asn_oid OIDX_hrFSUnknown_c = OIDX_hrFSUnknown;
125 
126 /* file system type map */
127 static const struct {
128 	const char		*str;	/* the type string */
129 	const struct asn_oid	*oid;	/* the OID to return */
130 } fs_type_map[] = {
131 	{ "ufs",	&OIDX_hrFSBerkeleyFFS_c },
132 	{ "zfs",	&OIDX_hrFSOther_c },
133 	{ "cd9660",	&OIDX_hrFSiso9660_c },
134 	{ "nfs",	&OIDX_hrFSNFS_c },
135 	{ "ext2fs",	&OIDX_hrFSLinuxExt2_c },
136 	{ "procfs",	&OIDX_hrFSOther_c },
137 	{ "devfs",	&OIDX_hrFSOther_c },
138 	{ "msdosfs",	&OIDX_hrFSFAT32_c },
139 	{ "ntfs",	&OIDX_hrFSNTFS_c },
140 	{ "nwfs",	&OIDX_hrFSNetware_c },
141 	{ "hpfs",	&OIDX_hrFSHPFS_c },
142 	{ "smbfs",	&OIDX_hrFSOther_c },
143 };
144 #define	N_FS_TYPE_MAP	nitems(fs_type_map)
145 
146 /**
147  * Create an entry into the FS table and an entry in the map (if needed).
148  */
149 static struct fs_entry *
150 fs_entry_create(const char *name)
151 {
152 	struct fs_entry	*entry;
153 	struct fs_map_entry *map;
154 
155 	assert(name != NULL);
156 	assert(strlen(name) > 0);
157 
158 	STAILQ_FOREACH(map, &fs_map, link)
159 		if (strcmp(map->a_name, name) == 0)
160 			break;
161 
162 	if (map == NULL) {
163 		size_t mount_point_len;
164 
165 		/* new object - get a new index */
166 		if (next_fs_index > INT_MAX) {
167 			/* Unrecoverable error - die clean and quicly*/
168 			syslog(LOG_ERR, "%s: hrFSTable index wrap", __func__);
169 			errx(EX_SOFTWARE, "hrFSTable index wrap");
170 		}
171 
172 		if ((map = malloc(sizeof(*map))) == NULL) {
173 			syslog(LOG_ERR, "%s: %m", __func__);
174 			return (NULL);
175 		}
176 
177 		mount_point_len = strlen(name) + 1;
178 		if (mount_point_len > FS_MP_MLEN)
179 			mount_point_len = FS_MP_MLEN;
180 
181 		if ((map->a_name = malloc(mount_point_len)) == NULL) {
182 			syslog(LOG_ERR, "%s: %m", __func__);
183 			free(map);
184 			return (NULL);
185 		}
186 
187 		strlcpy(map->a_name, name, mount_point_len);
188 
189 		map->hrIndex = next_fs_index++;
190 		map->entry = NULL;
191 		STAILQ_INSERT_TAIL(&fs_map, map, link);
192 
193 		HRDBG("%s added into hrFSMap at index=%d", name, map->hrIndex);
194 	} else {
195 		HRDBG("%s exists in hrFSMap index=%d", name, map->hrIndex);
196 	}
197 
198 	if ((entry = malloc(sizeof(*entry))) == NULL) {
199 		syslog(LOG_WARNING, "%s: %m", __func__);
200 		return (NULL);
201 	}
202 
203 	if ((entry->mountPoint = strdup(name)) == NULL) {
204 		syslog(LOG_ERR, "%s: %m", __func__);
205 		free(entry);
206 		return (NULL);
207 	}
208 
209 	entry->index = map->hrIndex;
210 	map->entry = entry;
211 
212 	INSERT_OBJECT_INT(entry, &fs_tbl);
213 	return (entry);
214 }
215 
216 /**
217  * Delete an entry in the FS table.
218  */
219 static void
220 fs_entry_delete(struct fs_entry* entry)
221 {
222 	struct fs_map_entry *map;
223 
224 	assert(entry != NULL);
225 
226 	TAILQ_REMOVE(&fs_tbl, entry, link);
227 	STAILQ_FOREACH(map, &fs_map, link)
228 		if (map->entry == entry) {
229 			map->entry = NULL;
230 			break;
231 		}
232 	free(entry->mountPoint);
233 	free(entry->remoteMountPoint);
234 	free(entry);
235 }
236 
237 /**
238  * Find a table entry by its name
239  */
240 static struct fs_entry *
241 fs_find_by_name(const char *name)
242 {
243 	struct fs_entry *entry;
244 
245 	TAILQ_FOREACH(entry, &fs_tbl, link)
246 		if (strcmp(entry->mountPoint, name) == 0)
247 			return (entry);
248 
249 	return (NULL);
250 }
251 
252 /**
253  * Get rid of all data
254  */
255 void
256 fini_fs_tbl(void)
257 {
258 	struct fs_map_entry *n1;
259 
260      	while ((n1 = STAILQ_FIRST(&fs_map)) != NULL) {
261 		STAILQ_REMOVE_HEAD(&fs_map, link);
262 		if (n1->entry != NULL) {
263 			TAILQ_REMOVE(&fs_tbl, n1->entry, link);
264 			free(n1->entry->mountPoint);
265 			free(n1->entry->remoteMountPoint);
266 			free(n1->entry);
267 		}
268 		free(n1->a_name);
269 		free(n1);
270      	}
271 	assert(TAILQ_EMPTY(&fs_tbl));
272 }
273 
274 /**
275  * Called before the refreshing is started from the storage table.
276  */
277 void
278 fs_tbl_pre_refresh(void)
279 {
280 	struct fs_entry *entry;
281 
282 	/* mark each entry as missisng */
283 	TAILQ_FOREACH(entry, &fs_tbl, link)
284 		entry->flags &= ~HR_FS_FOUND;
285 }
286 
287 /**
288  * Called after refreshing from the storage table.
289  */
290 void
291 fs_tbl_post_refresh(void)
292 {
293 	struct fs_entry *entry, *entry_tmp;
294 
295 	/*
296 	 * Purge items that disappeared
297 	 */
298 	TAILQ_FOREACH_SAFE(entry, &fs_tbl, link, entry_tmp)
299 		if (!(entry->flags & HR_FS_FOUND))
300 			fs_entry_delete(entry);
301 
302 	fs_tick = this_tick;
303 }
304 
305 /*
306  * Refresh the FS table. This is done by forcing a refresh of the storage table.
307  */
308 void
309 refresh_fs_tbl(void)
310 {
311 
312 	if (fs_tick == 0 || this_tick - fs_tick >= fs_tbl_refresh) {
313 		refresh_storage_tbl(1);
314 		HRDBG("refresh DONE");
315 	}
316 }
317 
318 /**
319  * Get the type OID for a given file system
320  */
321 const struct asn_oid *
322 fs_get_type(const struct statfs *fs_p)
323 {
324 	u_int t;
325 
326 	assert(fs_p != NULL);
327 
328 	for (t = 0; t < N_FS_TYPE_MAP; t++)
329 		if (strcmp(fs_type_map[t].str, fs_p->f_fstypename) == 0)
330 			return (fs_type_map[t].oid);
331 
332 	return (&OIDX_hrFSUnknown_c);
333 }
334 
335 /*
336  * Given information returned from statfs(2) either create a new entry into
337  * the fs_tbl or refresh the entry if it is already there.
338  */
339 void
340 fs_tbl_process_statfs_entry(const struct statfs *fs_p, int32_t storage_idx)
341 {
342 	struct fs_entry *entry;
343 
344 	assert(fs_p != 0);
345 
346 	HRDBG("for hrStorageEntry::index %d", storage_idx);
347 
348 	if (fs_p == NULL)
349 		return;
350 
351 	if ((entry = fs_find_by_name(fs_p->f_mntonname)) != NULL ||
352 	    (entry = fs_entry_create(fs_p->f_mntonname)) != NULL) {
353 		entry->flags |= HR_FS_FOUND;
354 
355 		if (!(fs_p->f_flags & MNT_LOCAL)) {
356 			/* this is a remote mount */
357 			entry->remoteMountPoint = strdup(fs_p->f_mntfromname);
358 			/* if strdup failed, let it be NULL */
359 
360 		} else {
361 			entry->remoteMountPoint = strdup("");
362 			/* if strdup failed, let it be NULL */
363 		}
364 
365 		entry->type = fs_get_type(fs_p);
366 
367 		if ((fs_p->f_flags & MNT_RDONLY) == MNT_RDONLY)
368 			entry->access = FS_READ_ONLY;
369 		else
370 			entry->access = FS_READ_WRITE;
371 
372 		/* FIXME - bootable fs ?! */
373 		entry->bootable = TRUTH_MK((fs_p->f_flags & MNT_ROOTFS)
374 		    == MNT_ROOTFS);
375 
376 		entry->storageIndex = storage_idx;
377 
378 		/* Info not available */
379 		memset(entry->lastFullBackupDate, 0,
380 		    sizeof(entry->lastFullBackupDate));
381 
382 		/* Info not available */
383 		memset(entry->lastPartialBackupDate, 0,
384 		    sizeof(entry->lastPartialBackupDate));
385 
386 		handle_partition_fs_index(fs_p->f_mntfromname, entry->index);
387 	}
388 }
389 
390 /*
391  * This is the implementation for a generated (by our SNMP "compiler" tool)
392  * function prototype, see hostres_tree.h
393  * It handles the SNMP operations for hrFSTable
394  */
395 int
396 op_hrFSTable(struct snmp_context *ctx __unused, struct snmp_value *value,
397     u_int sub, u_int iidx __unused, enum snmp_op curr_op)
398 {
399 	struct fs_entry *entry;
400 
401 	refresh_fs_tbl();
402 
403 	switch (curr_op) {
404 
405 	case SNMP_OP_GETNEXT:
406 		if ((entry = NEXT_OBJECT_INT(&fs_tbl,
407 		    &value->var, sub)) == NULL)
408 			return (SNMP_ERR_NOSUCHNAME);
409 		value->var.len = sub + 1;
410 		value->var.subs[sub] = entry->index;
411 		goto get;
412 
413 	case SNMP_OP_GET:
414 		if ((entry = FIND_OBJECT_INT(&fs_tbl,
415 		    &value->var, sub)) == NULL)
416 			return (SNMP_ERR_NOSUCHNAME);
417 		goto get;
418 
419 	case SNMP_OP_SET:
420 		if ((entry = FIND_OBJECT_INT(&fs_tbl,
421 		    &value->var, sub)) == NULL)
422 			return (SNMP_ERR_NO_CREATION);
423 		return (SNMP_ERR_NOT_WRITEABLE);
424 
425 	case SNMP_OP_ROLLBACK:
426 	case SNMP_OP_COMMIT:
427 		abort();
428 	}
429 	abort();
430   get:
431 	switch (value->var.subs[sub - 1]) {
432 
433 	case LEAF_hrFSIndex:
434 		value->v.integer = entry->index;
435 		return (SNMP_ERR_NOERROR);
436 
437 	case LEAF_hrFSMountPoint:
438 		return (string_get(value, entry->mountPoint, -1));
439 
440 	case LEAF_hrFSRemoteMountPoint:
441 		if (entry->remoteMountPoint == NULL)
442 			return (string_get(value, "", -1));
443 		else
444 			return (string_get(value, entry->remoteMountPoint, -1));
445 		break;
446 
447 	case LEAF_hrFSType:
448 		assert(entry->type != NULL);
449 		value->v.oid = *(entry->type);
450 		return (SNMP_ERR_NOERROR);
451 
452 	case LEAF_hrFSAccess:
453 		value->v.integer = entry->access;
454 		return (SNMP_ERR_NOERROR);
455 
456 	case LEAF_hrFSBootable:
457 		value->v.integer = entry->bootable;
458 		return (SNMP_ERR_NOERROR);
459 
460 	case LEAF_hrFSStorageIndex:
461 		value->v.integer = entry->storageIndex;
462 		return (SNMP_ERR_NOERROR);
463 
464 	case LEAF_hrFSLastFullBackupDate:
465 		return (string_get(value, entry->lastFullBackupDate, 8));
466 
467 	case LEAF_hrFSLastPartialBackupDate:
468 		return (string_get(value, entry->lastPartialBackupDate, 8));
469 	}
470 	abort();
471 }
472