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 	{ "cd9660",	&OIDX_hrFSiso9660_c },
135 	{ "nfs",	&OIDX_hrFSNFS_c },
136 	{ "ext2fs",	&OIDX_hrFSLinuxExt2_c },
137 	{ "procfs",	&OIDX_hrFSOther_c },
138 	{ "devfs",	&OIDX_hrFSOther_c },
139 	{ "msdosfs",	&OIDX_hrFSFAT32_c },
140 	{ "ntfs",	&OIDX_hrFSNTFS_c },
141 	{ "nwfs",	&OIDX_hrFSNetware_c },
142 	{ "hpfs",	&OIDX_hrFSHPFS_c },
143 	{ "smbfs",	&OIDX_hrFSOther_c },
144 };
145 #define	N_FS_TYPE_MAP	(sizeof(fs_type_map) / sizeof(fs_type_map[0]))
146 
147 /**
148  * Create an entry into the FS table and an entry in the map (if needed).
149  */
150 static struct fs_entry *
151 fs_entry_create(const char *name)
152 {
153 	struct fs_entry	*entry;
154 	struct fs_map_entry *map;
155 
156 	assert(name != NULL);
157 	assert(strlen(name) > 0);
158 
159 	STAILQ_FOREACH(map, &fs_map, link)
160 		if (strcmp(map->a_name, name) == 0)
161 			break;
162 
163 	if (map == NULL) {
164 		size_t mount_point_len;
165 
166 		/* new object - get a new index */
167 		if (next_fs_index > INT_MAX) {
168 			/* Unrecoverable error - die clean and quicly*/
169 		        syslog(LOG_ERR, "%s: hrFSTable index wrap", __func__);
170 			errx(EX_SOFTWARE, "hrFSTable index wrap");
171 		}
172 
173 		if ((map = malloc(sizeof(*map))) == NULL) {
174 			syslog(LOG_ERR, "%s: %m", __func__);
175 			return (NULL);
176 		}
177 
178 		mount_point_len = strlen(name) + 1;
179 		if (mount_point_len > FS_MP_MLEN)
180 			mount_point_len = FS_MP_MLEN;
181 
182 		if ((map->a_name = malloc(mount_point_len)) == NULL) {
183 			syslog(LOG_ERR, "%s: %m", __func__);
184 			free(map);
185 			return (NULL);
186 		}
187 
188 		strlcpy(map->a_name, name, mount_point_len);
189 
190 		map->hrIndex = next_fs_index++;
191 		map->entry = NULL;
192 		STAILQ_INSERT_TAIL(&fs_map, map, link);
193 
194 		HRDBG("%s added into hrFSMap at index=%d", name, map->hrIndex);
195 	} else {
196 		HRDBG("%s exists in hrFSMap index=%d", name, map->hrIndex);
197 	}
198 
199 	if ((entry = malloc(sizeof(*entry))) == NULL) {
200 		syslog(LOG_WARNING, "%s: %m", __func__);
201 		return (NULL);
202 	}
203 
204 	if ((entry->mountPoint = strdup(name)) == NULL) {
205 		syslog(LOG_ERR, "%s: %m", __func__);
206 		free(entry);
207 		return (NULL);
208 	}
209 
210 	entry->index = map->hrIndex;
211 	map->entry = entry;
212 
213 	INSERT_OBJECT_INT(entry, &fs_tbl);
214 	return (entry);
215 }
216 
217 /**
218  * Delete an entry in the FS table.
219  */
220 static void
221 fs_entry_delete(struct fs_entry* entry)
222 {
223 	struct fs_map_entry *map;
224 
225 	assert(entry != NULL);
226 
227 	TAILQ_REMOVE(&fs_tbl, entry, link);
228 	STAILQ_FOREACH(map, &fs_map, link)
229 		if (map->entry == entry) {
230 			map->entry = NULL;
231 			break;
232 		}
233 	free(entry->mountPoint);
234 	free(entry->remoteMountPoint);
235 	free(entry);
236 }
237 
238 /**
239  * Find a table entry by its name
240  */
241 static struct fs_entry *
242 fs_find_by_name(const char *name)
243 {
244 	struct fs_entry *entry;
245 
246 	TAILQ_FOREACH(entry, &fs_tbl, link)
247 		if (strcmp(entry->mountPoint, name) == 0)
248 			return (entry);
249 
250 	return (NULL);
251 }
252 
253 /**
254  * Get rid of all data
255  */
256 void
257 fini_fs_tbl(void)
258 {
259 	struct fs_map_entry *n1;
260 
261      	while ((n1 = STAILQ_FIRST(&fs_map)) != NULL) {
262 		STAILQ_REMOVE_HEAD(&fs_map, link);
263 		if (n1->entry != NULL) {
264 			TAILQ_REMOVE(&fs_tbl, n1->entry, link);
265 			free(n1->entry->mountPoint);
266 			free(n1->entry->remoteMountPoint);
267 			free(n1->entry);
268 		}
269 		free(n1->a_name);
270 		free(n1);
271      	}
272 	assert(TAILQ_EMPTY(&fs_tbl));
273 }
274 
275 /**
276  * Called before the refreshing is started from the storage table.
277  */
278 void
279 fs_tbl_pre_refresh(void)
280 {
281 	struct fs_entry *entry;
282 
283 	/* mark each entry as missisng */
284 	TAILQ_FOREACH(entry, &fs_tbl, link)
285 		entry->flags &= ~HR_FS_FOUND;
286 }
287 
288 /**
289  * Called after refreshing from the storage table.
290  */
291 void
292 fs_tbl_post_refresh(void)
293 {
294 	struct fs_entry *entry, *entry_tmp;
295 
296 	/*
297 	 * Purge items that disappeared
298 	 */
299 	TAILQ_FOREACH_SAFE(entry, &fs_tbl, link, entry_tmp)
300 		if (!(entry->flags & HR_FS_FOUND))
301 			fs_entry_delete(entry);
302 
303 	fs_tick = this_tick;
304 }
305 
306 /*
307  * Refresh the FS table. This is done by forcing a refresh of the storage table.
308  */
309 void
310 refresh_fs_tbl(void)
311 {
312 
313 	if (fs_tick == 0 || this_tick - fs_tick >= fs_tbl_refresh) {
314 		refresh_storage_tbl(1);
315 		HRDBG("refresh DONE");
316 	}
317 }
318 
319 /**
320  * Get the type OID for a given file system
321  */
322 const struct asn_oid *
323 fs_get_type(const struct statfs *fs_p)
324 {
325 	u_int t;
326 
327 	assert(fs_p != NULL);
328 
329 	for (t = 0; t < N_FS_TYPE_MAP; t++)
330 		if (strcmp(fs_type_map[t].str, fs_p->f_fstypename) == 0)
331 			return (fs_type_map[t].oid);
332 
333 	return (&OIDX_hrFSUnknown_c);
334 }
335 
336 /*
337  * Given information returned from statfs(2) either create a new entry into
338  * the fs_tbl or refresh the entry if it is already there.
339  */
340 void
341 fs_tbl_process_statfs_entry(const struct statfs *fs_p, int32_t storage_idx)
342 {
343 	struct fs_entry *entry;
344 
345 	assert(fs_p != 0);
346 
347 	HRDBG("for hrStorageEntry::index %d", storage_idx);
348 
349 	if (fs_p == NULL)
350 		return;
351 
352 	if ((entry = fs_find_by_name(fs_p->f_mntonname)) != NULL ||
353 	    (entry = fs_entry_create(fs_p->f_mntonname)) != NULL) {
354 		entry->flags |= HR_FS_FOUND;
355 
356 		if (!(fs_p->f_flags & MNT_LOCAL)) {
357 			/* this is a remote mount */
358 			entry->remoteMountPoint = strdup(fs_p->f_mntfromname);
359 			/* if strdup failed, let it be NULL */
360 
361 		} else {
362 			entry->remoteMountPoint = strdup("");
363 			/* if strdup failed, let it be NULL */
364 		}
365 
366 		entry->type = fs_get_type(fs_p);
367 
368 		if ((fs_p->f_flags & MNT_RDONLY) == MNT_RDONLY)
369 			entry->access = FS_READ_ONLY;
370 		else
371 			entry->access = FS_READ_WRITE;
372 
373 		/* FIXME - bootable fs ?! */
374 		entry->bootable = TRUTH_MK((fs_p->f_flags & MNT_ROOTFS)
375 		    == MNT_ROOTFS);
376 
377 		entry->storageIndex = storage_idx;
378 
379 		/* Info not available */
380 		memset(entry->lastFullBackupDate, 0,
381 		    sizeof(entry->lastFullBackupDate));
382 
383 		/* Info not available */
384 		memset(entry->lastPartialBackupDate, 0,
385 		    sizeof(entry->lastPartialBackupDate));
386 
387 		handle_partition_fs_index(fs_p->f_mntfromname, entry->index);
388 	}
389 }
390 
391 /*
392  * This is the implementation for a generated (by our SNMP "compiler" tool)
393  * function prototype, see hostres_tree.h
394  * It handles the SNMP operations for hrFSTable
395  */
396 int
397 op_hrFSTable(struct snmp_context *ctx __unused, struct snmp_value *value,
398     u_int sub, u_int iidx __unused, enum snmp_op curr_op)
399 {
400 	struct fs_entry *entry;
401 
402 	refresh_fs_tbl();
403 
404 	switch (curr_op) {
405 
406 	case SNMP_OP_GETNEXT:
407 		if ((entry = NEXT_OBJECT_INT(&fs_tbl,
408 		    &value->var, sub)) == NULL)
409 			return (SNMP_ERR_NOSUCHNAME);
410 		value->var.len = sub + 1;
411 		value->var.subs[sub] = entry->index;
412 		goto get;
413 
414 	case SNMP_OP_GET:
415 		if ((entry = FIND_OBJECT_INT(&fs_tbl,
416 		    &value->var, sub)) == NULL)
417 			return (SNMP_ERR_NOSUCHNAME);
418 		goto get;
419 
420 	case SNMP_OP_SET:
421 		if ((entry = FIND_OBJECT_INT(&fs_tbl,
422 		    &value->var, sub)) == NULL)
423 			return (SNMP_ERR_NO_CREATION);
424 		return (SNMP_ERR_NOT_WRITEABLE);
425 
426 	case SNMP_OP_ROLLBACK:
427 	case SNMP_OP_COMMIT:
428 		abort();
429 	}
430 	abort();
431   get:
432 	switch (value->var.subs[sub - 1]) {
433 
434 	case LEAF_hrFSIndex:
435 		value->v.integer = entry->index;
436 		return (SNMP_ERR_NOERROR);
437 
438 	case LEAF_hrFSMountPoint:
439 		return (string_get(value, entry->mountPoint, -1));
440 
441 	case LEAF_hrFSRemoteMountPoint:
442 		if (entry->remoteMountPoint == NULL)
443 			return (string_get(value, "", -1));
444 		else
445 			return (string_get(value, entry->remoteMountPoint, -1));
446 		break;
447 
448 	case LEAF_hrFSType:
449 		assert(entry->type != NULL);
450 		value->v.oid = *(entry->type);
451 		return (SNMP_ERR_NOERROR);
452 
453 	case LEAF_hrFSAccess:
454 		value->v.integer = entry->access;
455 		return (SNMP_ERR_NOERROR);
456 
457 	case LEAF_hrFSBootable:
458 		value->v.integer = entry->bootable;
459 		return (SNMP_ERR_NOERROR);
460 
461 	case LEAF_hrFSStorageIndex:
462 		value->v.integer = entry->storageIndex;
463 		return (SNMP_ERR_NOERROR);
464 
465 	case LEAF_hrFSLastFullBackupDate:
466 		return (string_get(value, entry->lastFullBackupDate, 8));
467 
468 	case LEAF_hrFSLastPartialBackupDate:
469 		return (string_get(value, entry->lastPartialBackupDate, 8));
470 	}
471 	abort();
472 }
473