smi.c revision 1.3 
1/*	$OpenBSD: smi.c,v 1.3 2019/08/11 15:52:46 deraadt Exp $	*/
2
3/*
4 * Copyright (c) 2019 Martijn van Duren <martijn@openbsd.org>
5 * Copyright (c) 2007, 2008 Reyk Floeter <reyk@openbsd.org>
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20#include <sys/limits.h>
21#include <sys/tree.h>
22#include <sys/queue.h>
23
24#include <arpa/inet.h>
25
26#include <ctype.h>
27#include <stdlib.h>
28#include <stdio.h>
29#include <string.h>
30#include <strings.h>
31
32#include "ber.h"
33#include "mib.h"
34#include "snmp.h"
35#include "smi.h"
36
37#define MINIMUM(a, b)	(((a) < (b)) ? (a) : (b))
38
39int smi_oid_cmp(struct oid *, struct oid *);
40int smi_key_cmp(struct oid *, struct oid *);
41struct oid * smi_findkey(char *);
42
43RB_HEAD(oidtree, oid);
44RB_PROTOTYPE(oidtree, oid, o_element, smi_oid_cmp)
45struct oidtree smi_oidtree;
46
47RB_HEAD(keytree, oid);
48RB_PROTOTYPE(keytree, oid, o_keyword, smi_key_cmp)
49struct keytree smi_keytree;
50
51int
52smi_init(void)
53{
54	/* Initialize the Structure of Managed Information (SMI) */
55	RB_INIT(&smi_oidtree);
56	mib_init();
57	return (0);
58}
59
60void
61smi_debug_elements(struct ber_element *root)
62{
63	static int	 indent = 0;
64	char		*value;
65	int		 constructed;
66
67	/* calculate lengths */
68	ber_calc_len(root);
69
70	switch (root->be_encoding) {
71	case BER_TYPE_SEQUENCE:
72	case BER_TYPE_SET:
73		constructed = root->be_encoding;
74		break;
75	default:
76		constructed = 0;
77		break;
78	}
79
80	fprintf(stderr, "%*slen %lu ", indent, "", root->be_len);
81	switch (root->be_class) {
82	case BER_CLASS_UNIVERSAL:
83		fprintf(stderr, "class: universal(%u) type: ", root->be_class);
84		switch (root->be_type) {
85		case BER_TYPE_EOC:
86			fprintf(stderr, "end-of-content");
87			break;
88		case BER_TYPE_BOOLEAN:
89			fprintf(stderr, "boolean");
90			break;
91		case BER_TYPE_INTEGER:
92			fprintf(stderr, "integer");
93			break;
94		case BER_TYPE_BITSTRING:
95			fprintf(stderr, "bit-string");
96			break;
97		case BER_TYPE_OCTETSTRING:
98			fprintf(stderr, "octet-string");
99			break;
100		case BER_TYPE_NULL:
101			fprintf(stderr, "null");
102			break;
103		case BER_TYPE_OBJECT:
104			fprintf(stderr, "object");
105			break;
106		case BER_TYPE_ENUMERATED:
107			fprintf(stderr, "enumerated");
108			break;
109		case BER_TYPE_SEQUENCE:
110			fprintf(stderr, "sequence");
111			break;
112		case BER_TYPE_SET:
113			fprintf(stderr, "set");
114			break;
115		}
116		break;
117	case BER_CLASS_APPLICATION:
118		fprintf(stderr, "class: application(%u) type: ",
119		    root->be_class);
120		switch (root->be_type) {
121		case SNMP_T_IPADDR:
122			fprintf(stderr, "ipaddr");
123			break;
124		case SNMP_T_COUNTER32:
125			fprintf(stderr, "counter32");
126			break;
127		case SNMP_T_GAUGE32:
128			fprintf(stderr, "gauge32");
129			break;
130		case SNMP_T_TIMETICKS:
131			fprintf(stderr, "timeticks");
132			break;
133		case SNMP_T_OPAQUE:
134			fprintf(stderr, "opaque");
135			break;
136		case SNMP_T_COUNTER64:
137			fprintf(stderr, "counter64");
138			break;
139		}
140		break;
141	case BER_CLASS_CONTEXT:
142		fprintf(stderr, "class: context(%u) type: ",
143		    root->be_class);
144		switch (root->be_type) {
145		case SNMP_C_GETREQ:
146			fprintf(stderr, "getreq");
147			break;
148		case SNMP_C_GETNEXTREQ:
149			fprintf(stderr, "nextreq");
150			break;
151		case SNMP_C_GETRESP:
152			fprintf(stderr, "getresp");
153			break;
154		case SNMP_C_SETREQ:
155			fprintf(stderr, "setreq");
156			break;
157		case SNMP_C_TRAP:
158			fprintf(stderr, "trap");
159			break;
160		case SNMP_C_GETBULKREQ:
161			fprintf(stderr, "getbulkreq");
162			break;
163		case SNMP_C_INFORMREQ:
164			fprintf(stderr, "informreq");
165			break;
166		case SNMP_C_TRAPV2:
167			fprintf(stderr, "trapv2");
168			break;
169		case SNMP_C_REPORT:
170			fprintf(stderr, "report");
171			break;
172		}
173		break;
174	case BER_CLASS_PRIVATE:
175		fprintf(stderr, "class: private(%u) type: ", root->be_class);
176		break;
177	default:
178		fprintf(stderr, "class: <INVALID>(%u) type: ", root->be_class);
179		break;
180	}
181	fprintf(stderr, "(%u) encoding %u ",
182	    root->be_type, root->be_encoding);
183
184	if ((value = smi_print_element(root, 1, smi_os_default,
185	    smi_oidl_numeric)) == NULL)
186		goto invalid;
187
188	switch (root->be_encoding) {
189	case BER_TYPE_BOOLEAN:
190		fprintf(stderr, "%s", value);
191		break;
192	case BER_TYPE_INTEGER:
193	case BER_TYPE_ENUMERATED:
194		fprintf(stderr, "value %s", value);
195		break;
196	case BER_TYPE_BITSTRING:
197		fprintf(stderr, "hexdump %s", value);
198		break;
199	case BER_TYPE_OBJECT:
200		fprintf(stderr, "oid %s", value);
201		break;
202	case BER_TYPE_OCTETSTRING:
203		if (root->be_class == BER_CLASS_APPLICATION &&
204		    root->be_type == SNMP_T_IPADDR) {
205			fprintf(stderr, "addr %s", value);
206		} else {
207			fprintf(stderr, "string %s", value);
208		}
209		break;
210	case BER_TYPE_NULL:	/* no payload */
211	case BER_TYPE_EOC:
212	case BER_TYPE_SEQUENCE:
213	case BER_TYPE_SET:
214	default:
215		fprintf(stderr, "%s", value);
216		break;
217	}
218
219 invalid:
220	if (value == NULL)
221		fprintf(stderr, "<INVALID>");
222	else
223		free(value);
224	fprintf(stderr, "\n");
225
226	if (constructed)
227		root->be_encoding = constructed;
228
229	if (constructed && root->be_sub) {
230		indent += 2;
231		smi_debug_elements(root->be_sub);
232		indent -= 2;
233	}
234	if (root->be_next)
235		smi_debug_elements(root->be_next);
236}
237
238char *
239smi_print_element(struct ber_element *root, int print_hint,
240    enum smi_output_string output_string, enum smi_oid_lookup lookup)
241{
242	char		*str = NULL, *buf, *p;
243	size_t		 len, i;
244	long long	 v, ticks;
245	int		 d;
246	int		 is_hex = 0;
247	struct ber_oid	 o;
248	char		 strbuf[BUFSIZ];
249	char		*hint;
250	int		 days, hours, min, sec, csec;
251
252	switch (root->be_encoding) {
253	case BER_TYPE_BOOLEAN:
254		if (ber_get_boolean(root, &d) == -1)
255			goto fail;
256		if (print_hint) {
257			if (asprintf(&str, "INTEGER: %s(%d)",
258			    d ? "true" : "false", d) == -1)
259				goto fail;
260		} else
261			if (asprintf(&str, "%s", d ? "true" : "false") == -1)
262				goto fail;
263		break;
264	case BER_TYPE_INTEGER:
265	case BER_TYPE_ENUMERATED:
266		if (ber_get_integer(root, &v) == -1)
267			goto fail;
268		if (root->be_class == BER_CLASS_APPLICATION &&
269		    root->be_type == SNMP_T_TIMETICKS) {
270			ticks = v;
271			days = ticks / (60 * 60 * 24 * 100);
272			ticks %= (60 * 60 * 24 * 100);
273			hours = ticks / (60 * 60 * 100);
274			ticks %= (60 * 60 * 100);
275			min = ticks / (60 * 100);
276			ticks %= (60 * 100);
277			sec = ticks / 100;
278			ticks %= 100;
279			csec = ticks;
280
281			if (print_hint) {
282				if (days == 0) {
283					if (asprintf(&str,
284					    "Timeticks: (%lld) "
285					    "%d:%02d:%02d.%02d",
286					    v, hours, min, sec, csec) == -1)
287						goto fail;
288				} else if (days == 1) {
289					if (asprintf(&str,
290					    "Timeticks: (%lld) "
291					    "1 day %d:%02d:%02d.%02d",
292					    v, hours, min, sec, csec) == -1)
293						goto fail;
294				} else {
295					if (asprintf(&str,
296					    "Timeticks: (%lld) "
297					    "%d day %d:%02d:%02d.%02d",
298					    v, days, hours, min, sec, csec) ==
299					    -1)
300						goto fail;
301				}
302			} else {
303				if (days == 0) {
304					if (asprintf(&str, "%d:%02d:%02d.%02d",
305					    hours, min, sec, csec) == -1)
306						goto fail;
307				} else if (days == 1) {
308					if (asprintf(&str,
309					    "1 day %d:%02d:%02d.%02d",
310					    hours, min, sec, csec) == -1)
311						goto fail;
312				} else {
313					if (asprintf(&str,
314					    "%d day %d:%02d:%02d.%02d",
315					    days, hours, min, sec, csec) == -1)
316						goto fail;
317				}
318			}
319			break;
320		}
321		hint = "INTEGER: ";
322		if (root->be_class == BER_CLASS_APPLICATION) {
323			if (root->be_type == SNMP_T_COUNTER32)
324				hint = "Counter32: ";
325			else if (root->be_type == SNMP_T_GAUGE32)
326				hint = "Gauge32: ";
327			else if (root->be_type == SNMP_T_OPAQUE)
328				hint = "Opaque: ";
329			else if (root->be_type == SNMP_T_COUNTER64)
330				hint = "Counter64: ";
331		}
332		if (asprintf(&str, "%s%lld", print_hint ? hint : "", v) == -1)
333			goto fail;
334		break;
335	case BER_TYPE_BITSTRING:
336		if (ber_get_bitstring(root, (void *)&buf, &len) == -1)
337			goto fail;
338		if ((str = calloc(1, len * 2 + 1 + sizeof("BITS: "))) == NULL)
339			goto fail;
340		p = str;
341		if (print_hint) {
342			strlcpy(str, "BITS: ", sizeof(str));
343			p += sizeof("BITS: ");
344		}
345		for (i = 0; i < len; i++) {
346			snprintf(p, 3, "%02x", buf[i]);
347			p += 2;
348		}
349		break;
350	case BER_TYPE_OBJECT:
351		if (ber_get_oid(root, &o) == -1)
352			goto fail;
353		if (asprintf(&str, "%s%s",
354		    print_hint ? "OID: " : "",
355		    smi_oid2string(&o, strbuf, sizeof(strbuf), lookup)) == -1)
356			goto fail;
357		break;
358	case BER_TYPE_OCTETSTRING:
359		if (ber_get_string(root, &buf) == -1)
360			goto fail;
361		if (root->be_class == BER_CLASS_APPLICATION &&
362		    root->be_type == SNMP_T_IPADDR) {
363			if (asprintf(&str, "%s%s",
364			    print_hint ? "IpAddress: " : "",
365			    inet_ntoa(*(struct in_addr *)buf)) == -1)
366				goto fail;
367		} else if (root->be_class == BER_CLASS_CONTEXT &&
368		    root->be_type == BER_TYPE_EOC) {
369			str = strdup("No Such Object available on this agent at this OID");
370		} else {
371			for (i = 0; i < root->be_len; i++) {
372				if (!isprint(buf[i])) {
373					if (output_string == smi_os_default)
374						output_string = smi_os_hex;
375					else if (output_string == smi_os_ascii)
376						is_hex = 1;
377					break;
378				}
379			}
380			/*
381			 * hex is 3 * n (2 digits + n - 1 spaces + NUL-byte)
382			 * ascii can be max (2 * n) + 2 quotes + NUL-byte
383			 */
384			if ((p = str = reallocarray(NULL,
385			    output_string == smi_os_hex ? 3 : 2,
386			    root->be_len + 2)) == NULL)
387				goto fail;
388			if (is_hex)
389				*str++ = '"';
390			for (i = 0; i < root->be_len; i++) {
391				switch (output_string) {
392				case smi_os_default:
393					/* FALLTHROUGH */
394				case smi_os_ascii:
395					/*
396					 * There's probably more edgecases here,
397					 * not fully investigated
398					 */
399					if (is_hex && buf[i] == '\\')
400						*str++ = '\\';
401					*str++ = isprint(buf[i]) ? buf[i] : '.';
402					break;
403				case smi_os_hex:
404					sprintf(str, "%s%02hhX",
405					    i == 0 ? "" :
406					    i % 16 == 0 ? "\n" : " ", buf[i]);
407					str += i == 0 ? 2 : 3;
408					break;
409				}
410			}
411			if (is_hex)
412				*str++ = '"';
413			*str = '\0';
414			str = NULL;
415			if (asprintf(&str, "%s%s",
416			    print_hint ?
417			    output_string == smi_os_hex ? "Hex-STRING: " :
418			    "STRING: " :
419			    "", p) == -1) {
420				free(p);
421				goto fail;
422			}
423			free(p);
424		}
425		break;
426	case BER_TYPE_NULL:	/* no payload */
427	case BER_TYPE_EOC:
428	case BER_TYPE_SEQUENCE:
429	case BER_TYPE_SET:
430	default:
431		str = strdup("");
432		break;
433	}
434
435	return (str);
436
437 fail:
438	free(str);
439	return (NULL);
440}
441
442int
443smi_string2oid(const char *oidstr, struct ber_oid *o)
444{
445	char			*sp, *p, str[BUFSIZ];
446	const char		*errstr;
447	struct oid		*oid;
448	struct ber_oid		 ko;
449
450	if (strlcpy(str, oidstr, sizeof(str)) >= sizeof(str))
451		return (-1);
452	bzero(o, sizeof(*o));
453
454	/*
455	 * Parse OID strings in the common form n.n.n or n-n-n.
456	 * Based on ber_string2oid with additional support for symbolic names.
457	 */
458	p = sp = str[0] == '.' ? str + 1 : str;
459	for (; p != NULL; sp = p) {
460		if ((p = strpbrk(p, ".-")) != NULL)
461			*p++ = '\0';
462		if ((oid = smi_findkey(sp)) != NULL) {
463			bcopy(&oid->o_id, &ko, sizeof(ko));
464			if (o->bo_n && ber_oid_cmp(o, &ko) != 2)
465				return (-1);
466			bcopy(&ko, o, sizeof(*o));
467			errstr = NULL;
468		} else {
469			o->bo_id[o->bo_n++] =
470			    strtonum(sp, 0, UINT_MAX, &errstr);
471		}
472		if (errstr || o->bo_n > BER_MAX_OID_LEN)
473			return (-1);
474	}
475
476	return (0);
477}
478
479unsigned int
480smi_application(struct ber_element *elm)
481{
482	if (elm->be_class != BER_CLASS_APPLICATION)
483		return (BER_TYPE_OCTETSTRING);
484
485	switch (elm->be_type) {
486	case SNMP_T_IPADDR:
487		return (BER_TYPE_OCTETSTRING);
488	case SNMP_T_COUNTER32:
489	case SNMP_T_GAUGE32:
490	case SNMP_T_TIMETICKS:
491	case SNMP_T_OPAQUE:
492	case SNMP_T_COUNTER64:
493		return (BER_TYPE_INTEGER);
494	default:
495		break;
496	}
497	return (BER_TYPE_OCTETSTRING);
498
499}
500
501char *
502smi_oid2string(struct ber_oid *o, char *buf, size_t len,
503    enum smi_oid_lookup lookup)
504{
505	char		 str[256];
506	struct oid	*value, key;
507	size_t		 i;
508
509	bzero(buf, len);
510	bzero(&key, sizeof(key));
511	bcopy(o, &key.o_id, sizeof(struct ber_oid));
512	key.o_flags |= OID_KEY;		/* do not match wildcards */
513
514	for (i = 0; i < o->bo_n; i++) {
515		key.o_oidlen = i + 1;
516		if (lookup != smi_oidl_numeric &&
517		    (value = RB_FIND(oidtree, &smi_oidtree, &key)) != NULL) {
518			snprintf(str, sizeof(str), "%s", value->o_name);
519			if (lookup == smi_oidl_short && i + 1 < o->bo_n) {
520				key.o_oidlen = i + 2;
521				if (RB_FIND(oidtree, &smi_oidtree, &key) != NULL)
522					continue;
523			}
524		} else
525			snprintf(str, sizeof(str), "%d", key.o_oid[i]);
526		if (*buf != '\0' || i == 0)
527			strlcat(buf, ".", len);
528		strlcat(buf, str, len);
529	}
530
531	return (buf);
532}
533
534void
535smi_mibtree(struct oid *oids)
536{
537	struct oid	*oid, *decl;
538	size_t		 i;
539
540	for (i = 0; oids[i].o_oid[0] != 0; i++) {
541		oid = &oids[i];
542		if (oid->o_name != NULL) {
543			RB_INSERT(oidtree, &smi_oidtree, oid);
544			RB_INSERT(keytree, &smi_keytree, oid);
545			continue;
546		}
547		decl = RB_FIND(oidtree, &smi_oidtree, oid);
548		decl->o_flags = oid->o_flags;
549		decl->o_get = oid->o_get;
550		decl->o_set = oid->o_set;
551		decl->o_table = oid->o_table;
552		decl->o_val = oid->o_val;
553		decl->o_data = oid->o_data;
554	}
555}
556
557struct oid *
558smi_findkey(char *name)
559{
560	struct oid	oid;
561	if (name == NULL)
562		return (NULL);
563	oid.o_name = name;
564	return (RB_FIND(keytree, &smi_keytree, &oid));
565}
566
567struct oid *
568smi_foreach(struct oid *oid, u_int flags)
569{
570	/*
571	 * Traverse the tree of MIBs with the option to check
572	 * for specific OID flags.
573	 */
574	if (oid == NULL) {
575		oid = RB_MIN(oidtree, &smi_oidtree);
576		if (oid == NULL)
577			return (NULL);
578		if (flags == 0 || (oid->o_flags & flags))
579			return (oid);
580	}
581	for (;;) {
582		oid = RB_NEXT(oidtree, &smi_oidtree, oid);
583		if (oid == NULL)
584			break;
585		if (flags == 0 || (oid->o_flags & flags))
586			return (oid);
587	}
588
589	return (oid);
590}
591
592int
593smi_oid_cmp(struct oid *a, struct oid *b)
594{
595	size_t	 i;
596
597	for (i = 0; i < MINIMUM(a->o_oidlen, b->o_oidlen); i++) {
598		if (a->o_oid[i] != b->o_oid[i])
599			return (a->o_oid[i] - b->o_oid[i]);
600	}
601
602	/*
603	 * Return success if the matched object is a table
604	 * or a MIB registered by a subagent
605	 * (it will match any sub-elements)
606	 */
607	if ((b->o_flags & OID_TABLE ||
608	    b->o_flags & OID_REGISTERED) &&
609	    (a->o_flags & OID_KEY) == 0 &&
610	    (a->o_oidlen > b->o_oidlen))
611		return (0);
612
613	return (a->o_oidlen - b->o_oidlen);
614}
615
616int
617smi_key_cmp(struct oid *a, struct oid *b)
618{
619	if (a->o_name == NULL || b->o_name == NULL)
620		return (-1);
621	return (strcasecmp(a->o_name, b->o_name));
622}
623
624RB_GENERATE(oidtree, oid, o_element, smi_oid_cmp)
625RB_GENERATE(keytree, oid, o_keyword, smi_key_cmp)
626