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  * $FreeBSD$
30  */
31 
32 /*
33  * Host Resources MIB for SNMPd. Implementation for hrFSTable
34  */
35 
36 #include <sys/types.h>
37 #include <sys/param.h>
38 #include <sys/sysctl.h>
39 #include <sys/mount.h>
40 
41 #include <assert.h>
42 #include <err.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <syslog.h>
46 #include <sysexits.h>
47 
48 #include "hostres_snmp.h"
49 #include "hostres_oid.h"
50 #include "hostres_tree.h"
51 
52 /*
53  * File system access enum
54  */
55 enum hrFSAccess {
56 	FS_READ_WRITE = 1,
57 	FS_READ_ONLY  = 2
58 };
59 
60 /* maximum length (according to MIB) for fs_entry::mountPoint */
61 #define	FS_MP_MLEN	(128 + 1)
62 
63 /* maximum length (according to MIB) for fs_entry::remoteMountPoint */
64 #define	FS_RMP_MLEN	(128 + 1)
65 
66 /*
67  * This structure is used to hold a SNMP table entry
68  * for HOST-RESOURCES-MIB's hrFSTable
69  */
70 struct fs_entry {
71 	int32_t		index;
72 	u_char		*mountPoint;
73 	u_char		*remoteMountPoint;
74 	const struct asn_oid *type;
75 	int32_t		access;		/* enum hrFSAccess, see above */
76 	int32_t		bootable;	/* TruthValue */
77 	int32_t		storageIndex;	/* hrStorageTblEntry::index */
78 	u_char		lastFullBackupDate[11];
79 	u_char		lastPartialBackupDate[11];
80 #define	HR_FS_FOUND 0x001
81 	uint32_t	flags;		/* not in mib table, for internal use */
82 	TAILQ_ENTRY(fs_entry) link;
83 };
84 TAILQ_HEAD(fs_tbl, fs_entry);
85 
86 /*
87  * Next structure is used to keep o list of mappings from a specific name
88  * (a_name) to an entry in the hrFSTblEntry. We are trying to keep the same
89  * index for a specific name at least for the duration of one SNMP agent run.
90  */
91 struct fs_map_entry {
92 	int32_t		hrIndex;   /* used for fs_entry::index */
93 	u_char		*a_name;   /* map key same as fs_entry::mountPoint */
94 
95 	/* may be NULL if the respective hrFSTblEntry is (temporally) gone */
96 	struct fs_entry *entry;
97 	STAILQ_ENTRY(fs_map_entry) 	link;
98 };
99 STAILQ_HEAD(fs_map, fs_map_entry);
100 
101 /* head of the list with hrFSTable's entries */
102 static struct fs_tbl fs_tbl = TAILQ_HEAD_INITIALIZER(fs_tbl);
103 
104 /* for consistent table indexing */
105 static struct fs_map fs_map = STAILQ_HEAD_INITIALIZER(fs_map);
106 
107 /* next index available for hrFSTable */
108 static uint32_t	next_fs_index = 1;
109 
110 /* last tick when hrFSTable was updated */
111 static uint64_t fs_tick;
112 
113 /* maximum number of ticks between refreshs */
114 uint32_t fs_tbl_refresh = HR_FS_TBL_REFRESH * 100;
115 
116 /* some constants */
117 static const struct asn_oid OIDX_hrFSBerkeleyFFS_c = OIDX_hrFSBerkeleyFFS;
118 static const struct asn_oid OIDX_hrFSiso9660_c = OIDX_hrFSiso9660;
119 static const struct asn_oid OIDX_hrFSNFS_c = OIDX_hrFSNFS;
120 static const struct asn_oid OIDX_hrFSLinuxExt2_c = OIDX_hrFSLinuxExt2;
121 static const struct asn_oid OIDX_hrFSOther_c = OIDX_hrFSOther;
122 static const struct asn_oid OIDX_hrFSFAT32_c = OIDX_hrFSFAT32;
123 static const struct asn_oid OIDX_hrFSNTFS_c = OIDX_hrFSNTFS;
124 static const struct asn_oid OIDX_hrFSNetware_c = OIDX_hrFSNetware;
125 static const struct asn_oid OIDX_hrFSHPFS_c = OIDX_hrFSHPFS;
126 static const struct asn_oid OIDX_hrFSUnknown_c = OIDX_hrFSUnknown;
127 
128 /* file system type map */
129 static const struct {
130 	const char		*str;	/* the type string */
131 	const struct asn_oid	*oid;	/* the OID to return */
132 } fs_type_map[] = {
133 	{ "ufs",	&OIDX_hrFSBerkeleyFFS_c },
134 	{ "zfs",	&OIDX_hrFSOther_c },
135 	{ "cd9660",	&OIDX_hrFSiso9660_c },
136 	{ "nfs",	&OIDX_hrFSNFS_c },
137 	{ "ext2fs",	&OIDX_hrFSLinuxExt2_c },
138 	{ "procfs",	&OIDX_hrFSOther_c },
139 	{ "devfs",	&OIDX_hrFSOther_c },
140 	{ "msdosfs",	&OIDX_hrFSFAT32_c },
141 	{ "ntfs",	&OIDX_hrFSNTFS_c },
142 	{ "nwfs",	&OIDX_hrFSNetware_c },
143 	{ "hpfs",	&OIDX_hrFSHPFS_c },
144 	{ "smbfs",	&OIDX_hrFSOther_c },
145 };
146 #define	N_FS_TYPE_MAP	nitems(fs_type_map)
147 
148 /**
149  * Create an entry into the FS table and an entry in the map (if needed).
150  */
151 static struct fs_entry *
152 fs_entry_create(const char *name)
153 {
154 	struct fs_entry	*entry;
155 	struct fs_map_entry *map;
156 
157 	assert(name != NULL);
158 	assert(strlen(name) > 0);
159 
160 	STAILQ_FOREACH(map, &fs_map, link)
161 		if (strcmp(map->a_name, name) == 0)
162 			break;
163 
164 	if (map == NULL) {
165 		size_t mount_point_len;
166 
167 		/* new object - get a new index */
168 		if (next_fs_index > INT_MAX) {
169 			/* Unrecoverable error - die clean and quicly*/
170 			syslog(LOG_ERR, "%s: hrFSTable index wrap", __func__);
171 			errx(EX_SOFTWARE, "hrFSTable index wrap");
172 		}
173 
174 		if ((map = malloc(sizeof(*map))) == NULL) {
175 			syslog(LOG_ERR, "%s: %m", __func__);
176 			return (NULL);
177 		}
178 
179 		mount_point_len = strlen(name) + 1;
180 		if (mount_point_len > FS_MP_MLEN)
181 			mount_point_len = FS_MP_MLEN;
182 
183 		if ((map->a_name = malloc(mount_point_len)) == NULL) {
184 			syslog(LOG_ERR, "%s: %m", __func__);
185 			free(map);
186 			return (NULL);
187 		}
188 
189 		strlcpy(map->a_name, name, mount_point_len);
190 
191 		map->hrIndex = next_fs_index++;
192 		map->entry = NULL;
193 		STAILQ_INSERT_TAIL(&fs_map, map, link);
194 
195 		HRDBG("%s added into hrFSMap at index=%d", name, map->hrIndex);
196 	} else {
197 		HRDBG("%s exists in hrFSMap index=%d", name, map->hrIndex);
198 	}
199 
200 	if ((entry = malloc(sizeof(*entry))) == NULL) {
201 		syslog(LOG_WARNING, "%s: %m", __func__);
202 		return (NULL);
203 	}
204 
205 	if ((entry->mountPoint = strdup(name)) == NULL) {
206 		syslog(LOG_ERR, "%s: %m", __func__);
207 		free(entry);
208 		return (NULL);
209 	}
210 
211 	entry->index = map->hrIndex;
212 	map->entry = entry;
213 
214 	INSERT_OBJECT_INT(entry, &fs_tbl);
215 	return (entry);
216 }
217 
218 /**
219  * Delete an entry in the FS table.
220  */
221 static void
222 fs_entry_delete(struct fs_entry* entry)
223 {
224 	struct fs_map_entry *map;
225 
226 	assert(entry != NULL);
227 
228 	TAILQ_REMOVE(&fs_tbl, entry, link);
229 	STAILQ_FOREACH(map, &fs_map, link)
230 		if (map->entry == entry) {
231 			map->entry = NULL;
232 			break;
233 		}
234 	free(entry->mountPoint);
235 	free(entry->remoteMountPoint);
236 	free(entry);
237 }
238 
239 /**
240  * Find a table entry by its name
241  */
242 static struct fs_entry *
243 fs_find_by_name(const char *name)
244 {
245 	struct fs_entry *entry;
246 
247 	TAILQ_FOREACH(entry, &fs_tbl, link)
248 		if (strcmp(entry->mountPoint, name) == 0)
249 			return (entry);
250 
251 	return (NULL);
252 }
253 
254 /**
255  * Get rid of all data
256  */
257 void
258 fini_fs_tbl(void)
259 {
260 	struct fs_map_entry *n1;
261 
262      	while ((n1 = STAILQ_FIRST(&fs_map)) != NULL) {
263 		STAILQ_REMOVE_HEAD(&fs_map, link);
264 		if (n1->entry != NULL) {
265 			TAILQ_REMOVE(&fs_tbl, n1->entry, link);
266 			free(n1->entry->mountPoint);
267 			free(n1->entry->remoteMountPoint);
268 			free(n1->entry);
269 		}
270 		free(n1->a_name);
271 		free(n1);
272      	}
273 	assert(TAILQ_EMPTY(&fs_tbl));
274 }
275 
276 /**
277  * Called before the refreshing is started from the storage table.
278  */
279 void
280 fs_tbl_pre_refresh(void)
281 {
282 	struct fs_entry *entry;
283 
284 	/* mark each entry as missisng */
285 	TAILQ_FOREACH(entry, &fs_tbl, link)
286 		entry->flags &= ~HR_FS_FOUND;
287 }
288 
289 /**
290  * Called after refreshing from the storage table.
291  */
292 void
293 fs_tbl_post_refresh(void)
294 {
295 	struct fs_entry *entry, *entry_tmp;
296 
297 	/*
298 	 * Purge items that disappeared
299 	 */
300 	TAILQ_FOREACH_SAFE(entry, &fs_tbl, link, entry_tmp)
301 		if (!(entry->flags & HR_FS_FOUND))
302 			fs_entry_delete(entry);
303 
304 	fs_tick = this_tick;
305 }
306 
307 /*
308  * Refresh the FS table. This is done by forcing a refresh of the storage table.
309  */
310 void
311 refresh_fs_tbl(void)
312 {
313 
314 	if (fs_tick == 0 || this_tick - fs_tick >= fs_tbl_refresh) {
315 		refresh_storage_tbl(1);
316 		HRDBG("refresh DONE");
317 	}
318 }
319 
320 /**
321  * Get the type OID for a given file system
322  */
323 const struct asn_oid *
324 fs_get_type(const struct statfs *fs_p)
325 {
326 	u_int t;
327 
328 	assert(fs_p != NULL);
329 
330 	for (t = 0; t < N_FS_TYPE_MAP; t++)
331 		if (strcmp(fs_type_map[t].str, fs_p->f_fstypename) == 0)
332 			return (fs_type_map[t].oid);
333 
334 	return (&OIDX_hrFSUnknown_c);
335 }
336 
337 /*
338  * Given information returned from statfs(2) either create a new entry into
339  * the fs_tbl or refresh the entry if it is already there.
340  */
341 void
342 fs_tbl_process_statfs_entry(const struct statfs *fs_p, int32_t storage_idx)
343 {
344 	struct fs_entry *entry;
345 
346 	assert(fs_p != 0);
347 
348 	HRDBG("for hrStorageEntry::index %d", storage_idx);
349 
350 	if (fs_p == NULL)
351 		return;
352 
353 	if ((entry = fs_find_by_name(fs_p->f_mntonname)) != NULL ||
354 	    (entry = fs_entry_create(fs_p->f_mntonname)) != NULL) {
355 		entry->flags |= HR_FS_FOUND;
356 
357 		if (!(fs_p->f_flags & MNT_LOCAL)) {
358 			/* this is a remote mount */
359 			entry->remoteMountPoint = strdup(fs_p->f_mntfromname);
360 			/* if strdup failed, let it be NULL */
361 
362 		} else {
363 			entry->remoteMountPoint = strdup("");
364 			/* if strdup failed, let it be NULL */
365 		}
366 
367 		entry->type = fs_get_type(fs_p);
368 
369 		if ((fs_p->f_flags & MNT_RDONLY) == MNT_RDONLY)
370 			entry->access = FS_READ_ONLY;
371 		else
372 			entry->access = FS_READ_WRITE;
373 
374 		/* FIXME - bootable fs ?! */
375 		entry->bootable = TRUTH_MK((fs_p->f_flags & MNT_ROOTFS)
376 		    == MNT_ROOTFS);
377 
378 		entry->storageIndex = storage_idx;
379 
380 		/* Info not available */
381 		memset(entry->lastFullBackupDate, 0,
382 		    sizeof(entry->lastFullBackupDate));
383 
384 		/* Info not available */
385 		memset(entry->lastPartialBackupDate, 0,
386 		    sizeof(entry->lastPartialBackupDate));
387 
388 		handle_partition_fs_index(fs_p->f_mntfromname, entry->index);
389 	}
390 }
391 
392 /*
393  * This is the implementation for a generated (by our SNMP "compiler" tool)
394  * function prototype, see hostres_tree.h
395  * It handles the SNMP operations for hrFSTable
396  */
397 int
398 op_hrFSTable(struct snmp_context *ctx __unused, struct snmp_value *value,
399     u_int sub, u_int iidx __unused, enum snmp_op curr_op)
400 {
401 	struct fs_entry *entry;
402 
403 	refresh_fs_tbl();
404 
405 	switch (curr_op) {
406 
407 	case SNMP_OP_GETNEXT:
408 		if ((entry = NEXT_OBJECT_INT(&fs_tbl,
409 		    &value->var, sub)) == NULL)
410 			return (SNMP_ERR_NOSUCHNAME);
411 		value->var.len = sub + 1;
412 		value->var.subs[sub] = entry->index;
413 		goto get;
414 
415 	case SNMP_OP_GET:
416 		if ((entry = FIND_OBJECT_INT(&fs_tbl,
417 		    &value->var, sub)) == NULL)
418 			return (SNMP_ERR_NOSUCHNAME);
419 		goto get;
420 
421 	case SNMP_OP_SET:
422 		if ((entry = FIND_OBJECT_INT(&fs_tbl,
423 		    &value->var, sub)) == NULL)
424 			return (SNMP_ERR_NO_CREATION);
425 		return (SNMP_ERR_NOT_WRITEABLE);
426 
427 	case SNMP_OP_ROLLBACK:
428 	case SNMP_OP_COMMIT:
429 		abort();
430 	}
431 	abort();
432   get:
433 	switch (value->var.subs[sub - 1]) {
434 
435 	case LEAF_hrFSIndex:
436 		value->v.integer = entry->index;
437 		return (SNMP_ERR_NOERROR);
438 
439 	case LEAF_hrFSMountPoint:
440 		return (string_get(value, entry->mountPoint, -1));
441 
442 	case LEAF_hrFSRemoteMountPoint:
443 		if (entry->remoteMountPoint == NULL)
444 			return (string_get(value, "", -1));
445 		else
446 			return (string_get(value, entry->remoteMountPoint, -1));
447 		break;
448 
449 	case LEAF_hrFSType:
450 		assert(entry->type != NULL);
451 		value->v.oid = *(entry->type);
452 		return (SNMP_ERR_NOERROR);
453 
454 	case LEAF_hrFSAccess:
455 		value->v.integer = entry->access;
456 		return (SNMP_ERR_NOERROR);
457 
458 	case LEAF_hrFSBootable:
459 		value->v.integer = entry->bootable;
460 		return (SNMP_ERR_NOERROR);
461 
462 	case LEAF_hrFSStorageIndex:
463 		value->v.integer = entry->storageIndex;
464 		return (SNMP_ERR_NOERROR);
465 
466 	case LEAF_hrFSLastFullBackupDate:
467 		return (string_get(value, entry->lastFullBackupDate, 8));
468 
469 	case LEAF_hrFSLastPartialBackupDate:
470 		return (string_get(value, entry->lastPartialBackupDate, 8));
471 	}
472 	abort();
473 }
474