xref: /openbsd/usr.bin/snmp/smi.c (revision d415bd75)
1 /*	$OpenBSD: smi.c,v 1.15 2021/10/21 08:17:34 martijn 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 <errno.h>
28 #include <stdlib.h>
29 #include <stdio.h>
30 #include <string.h>
31 #include <strings.h>
32 #include <wctype.h>
33 
34 #include "ber.h"
35 #include "mib.h"
36 #include "snmp.h"
37 #include "smi.h"
38 
39 #define MINIMUM(a, b)	(((a) < (b)) ? (a) : (b))
40 
41 char *smi_displayhint_os(struct textconv *, int, const char *, size_t, int);
42 char *smi_displayhint_int(struct textconv*, int, long long);
43 
44 int smi_oid_cmp(struct oid *, struct oid *);
45 int smi_key_cmp(struct oid *, struct oid *);
46 int smi_textconv_cmp(struct textconv *, struct textconv *);
47 struct oid * smi_findkey(char *);
48 
49 RB_HEAD(oidtree, oid);
50 RB_PROTOTYPE(oidtree, oid, o_element, smi_oid_cmp)
51 struct oidtree smi_oidtree;
52 
53 RB_HEAD(keytree, oid);
54 RB_PROTOTYPE(keytree, oid, o_keyword, smi_key_cmp)
55 struct keytree smi_keytree;
56 
57 RB_HEAD(textconvtree, textconv);
58 RB_PROTOTYPE(textconvtree, textconv, tc_entry, smi_textconv_cmp);
59 struct textconvtree smi_tctree;
60 
61 int
62 smi_init(void)
63 {
64 	/* Initialize the Structure of Managed Information (SMI) */
65 	RB_INIT(&smi_oidtree);
66 	mib_init();
67 	return (0);
68 }
69 
70 void
71 smi_debug_elements(struct ber_element *root, int utf8)
72 {
73 	static int	 indent = 0;
74 	char		*value;
75 	int		 constructed;
76 
77 	/* calculate lengths */
78 	ober_calc_len(root);
79 
80 	switch (root->be_encoding) {
81 	case BER_TYPE_SEQUENCE:
82 	case BER_TYPE_SET:
83 		constructed = root->be_encoding;
84 		break;
85 	default:
86 		constructed = 0;
87 		break;
88 	}
89 
90 	fprintf(stderr, "%*slen %lu ", indent, "", root->be_len);
91 	switch (root->be_class) {
92 	case BER_CLASS_UNIVERSAL:
93 		fprintf(stderr, "class: universal(%u) type: ", root->be_class);
94 		switch (root->be_type) {
95 		case BER_TYPE_EOC:
96 			fprintf(stderr, "end-of-content");
97 			break;
98 		case BER_TYPE_INTEGER:
99 			fprintf(stderr, "integer");
100 			break;
101 		case BER_TYPE_BITSTRING:
102 			fprintf(stderr, "bit-string");
103 			break;
104 		case BER_TYPE_OCTETSTRING:
105 			fprintf(stderr, "octet-string");
106 			break;
107 		case BER_TYPE_NULL:
108 			fprintf(stderr, "null");
109 			break;
110 		case BER_TYPE_OBJECT:
111 			fprintf(stderr, "object");
112 			break;
113 		case BER_TYPE_ENUMERATED:
114 			fprintf(stderr, "enumerated");
115 			break;
116 		case BER_TYPE_SEQUENCE:
117 			fprintf(stderr, "sequence");
118 			break;
119 		case BER_TYPE_SET:
120 			fprintf(stderr, "set");
121 			break;
122 		}
123 		break;
124 	case BER_CLASS_APPLICATION:
125 		fprintf(stderr, "class: application(%u) type: ",
126 		    root->be_class);
127 		switch (root->be_type) {
128 		case SNMP_T_IPADDR:
129 			fprintf(stderr, "ipaddr");
130 			break;
131 		case SNMP_T_COUNTER32:
132 			fprintf(stderr, "counter32");
133 			break;
134 		case SNMP_T_GAUGE32:
135 			fprintf(stderr, "gauge32");
136 			break;
137 		case SNMP_T_TIMETICKS:
138 			fprintf(stderr, "timeticks");
139 			break;
140 		case SNMP_T_OPAQUE:
141 			fprintf(stderr, "opaque");
142 			break;
143 		case SNMP_T_COUNTER64:
144 			fprintf(stderr, "counter64");
145 			break;
146 		}
147 		break;
148 	case BER_CLASS_CONTEXT:
149 		fprintf(stderr, "class: context(%u) type: ",
150 		    root->be_class);
151 		switch (root->be_type) {
152 		case SNMP_C_GETREQ:
153 			fprintf(stderr, "getreq");
154 			break;
155 		case SNMP_C_GETNEXTREQ:
156 			fprintf(stderr, "nextreq");
157 			break;
158 		case SNMP_C_GETRESP:
159 			fprintf(stderr, "getresp");
160 			break;
161 		case SNMP_C_SETREQ:
162 			fprintf(stderr, "setreq");
163 			break;
164 		case SNMP_C_TRAP:
165 			fprintf(stderr, "trap");
166 			break;
167 		case SNMP_C_GETBULKREQ:
168 			fprintf(stderr, "getbulkreq");
169 			break;
170 		case SNMP_C_INFORMREQ:
171 			fprintf(stderr, "informreq");
172 			break;
173 		case SNMP_C_TRAPV2:
174 			fprintf(stderr, "trapv2");
175 			break;
176 		case SNMP_C_REPORT:
177 			fprintf(stderr, "report");
178 			break;
179 		}
180 		break;
181 	case BER_CLASS_PRIVATE:
182 		fprintf(stderr, "class: private(%u) type: ", root->be_class);
183 		break;
184 	default:
185 		fprintf(stderr, "class: <INVALID>(%u) type: ", root->be_class);
186 		break;
187 	}
188 	fprintf(stderr, "(%u) encoding %u ",
189 	    root->be_type, root->be_encoding);
190 
191 	if ((value = smi_print_element(NULL, root, 1, smi_os_default,
192 	    smi_oidl_numeric, utf8)) == NULL)
193 		goto invalid;
194 
195 	switch (root->be_encoding) {
196 	case BER_TYPE_INTEGER:
197 	case BER_TYPE_ENUMERATED:
198 		fprintf(stderr, "value %s", value);
199 		break;
200 	case BER_TYPE_BITSTRING:
201 		fprintf(stderr, "hexdump %s", value);
202 		break;
203 	case BER_TYPE_OBJECT:
204 		fprintf(stderr, "oid %s", value);
205 		break;
206 	case BER_TYPE_OCTETSTRING:
207 		if (root->be_class == BER_CLASS_APPLICATION &&
208 		    root->be_type == SNMP_T_IPADDR) {
209 			fprintf(stderr, "addr %s", value);
210 		} else {
211 			fprintf(stderr, "string %s", value);
212 		}
213 		break;
214 	case BER_TYPE_NULL:	/* no payload */
215 	case BER_TYPE_EOC:
216 	case BER_TYPE_SEQUENCE:
217 	case BER_TYPE_SET:
218 	default:
219 		fprintf(stderr, "%s", value);
220 		break;
221 	}
222 
223  invalid:
224 	if (value == NULL)
225 		fprintf(stderr, "<INVALID>");
226 	else
227 		free(value);
228 	fprintf(stderr, "\n");
229 
230 	if (constructed)
231 		root->be_encoding = constructed;
232 
233 	if (constructed && root->be_sub) {
234 		indent += 2;
235 		smi_debug_elements(root->be_sub, utf8);
236 		indent -= 2;
237 	}
238 	if (root->be_next)
239 		smi_debug_elements(root->be_next, utf8);
240 }
241 
242 char *
243 smi_print_element(struct ber_oid *oid, struct ber_element *root, int print_hint,
244     enum smi_output_string output_string, enum smi_oid_lookup lookup, int utf8)
245 {
246 	char		*str = NULL, *buf, *p;
247 	struct oid	 okey;
248 	struct oid	*object = NULL;
249 	struct textconv	 tckey;
250 	size_t		 len, i, slen;
251 	long long	 v, ticks;
252 	int		 is_hex = 0, ret;
253 	struct ber_oid	 o;
254 	char		 strbuf[BUFSIZ];
255 	char		*hint;
256 	int		 days, hours, min, sec, csec;
257 
258 	if (oid != NULL) {
259 		bcopy(oid, &(okey.o_id), sizeof(okey));
260 		do {
261 			object = RB_FIND(oidtree, &smi_oidtree, &okey);
262 			okey.o_id.bo_n--;
263 		} while (object == NULL && okey.o_id.bo_n > 0);
264 		if (object != NULL && object->o_textconv == NULL &&
265 		    object->o_tcname != NULL) {
266 			tckey.tc_name = object->o_tcname;
267 			object->o_textconv = RB_FIND(textconvtree, &smi_tctree,
268 			    &tckey);
269 		}
270 	}
271 
272 	switch (root->be_encoding) {
273 	case BER_TYPE_INTEGER:
274 	case BER_TYPE_ENUMERATED:
275 		if (ober_get_integer(root, &v) == -1)
276 			goto fail;
277 		if (root->be_class == BER_CLASS_APPLICATION &&
278 		    root->be_type == SNMP_T_TIMETICKS) {
279 			ticks = v;
280 			days = ticks / (60 * 60 * 24 * 100);
281 			ticks %= (60 * 60 * 24 * 100);
282 			hours = ticks / (60 * 60 * 100);
283 			ticks %= (60 * 60 * 100);
284 			min = ticks / (60 * 100);
285 			ticks %= (60 * 100);
286 			sec = ticks / 100;
287 			ticks %= 100;
288 			csec = ticks;
289 
290 			if (print_hint) {
291 				if (days == 0) {
292 					if (asprintf(&str,
293 					    "Timeticks: (%lld) "
294 					    "%d:%02d:%02d.%02d",
295 					    v, hours, min, sec, csec) == -1)
296 						goto fail;
297 				} else if (days == 1) {
298 					if (asprintf(&str,
299 					    "Timeticks: (%lld) "
300 					    "1 day %d:%02d:%02d.%02d",
301 					    v, hours, min, sec, csec) == -1)
302 						goto fail;
303 				} else {
304 					if (asprintf(&str,
305 					    "Timeticks: (%lld) "
306 					    "%d day %d:%02d:%02d.%02d",
307 					    v, days, hours, min, sec, csec) ==
308 					    -1)
309 						goto fail;
310 				}
311 			} else {
312 				if (days == 0) {
313 					if (asprintf(&str, "%d:%02d:%02d.%02d",
314 					    hours, min, sec, csec) == -1)
315 						goto fail;
316 				} else if (days == 1) {
317 					if (asprintf(&str,
318 					    "1 day %d:%02d:%02d.%02d",
319 					    hours, min, sec, csec) == -1)
320 						goto fail;
321 				} else {
322 					if (asprintf(&str,
323 					    "%d day %d:%02d:%02d.%02d",
324 					    days, hours, min, sec, csec) == -1)
325 						goto fail;
326 				}
327 			}
328 			break;
329 		}
330 		hint = "INTEGER: ";
331 		if (object != NULL && object->o_textconv != NULL &&
332 		    object->o_textconv->tc_syntax == root->be_encoding)
333 			return smi_displayhint_int(object->o_textconv,
334 			    print_hint, v);
335 		if (root->be_class == BER_CLASS_APPLICATION) {
336 			if (root->be_type == SNMP_T_COUNTER32)
337 				hint = "Counter32: ";
338 			else if (root->be_type == SNMP_T_GAUGE32)
339 				hint = "Gauge32: ";
340 			else if (root->be_type == SNMP_T_OPAQUE)
341 				hint = "Opaque: ";
342 			else if (root->be_type == SNMP_T_COUNTER64)
343 				hint = "Counter64: ";
344 		}
345 		if (asprintf(&str, "%s%lld", print_hint ? hint : "", v) == -1)
346 			goto fail;
347 		break;
348 	case BER_TYPE_BITSTRING:
349 		if (ober_get_bitstring(root, (void *)&buf, &len) == -1)
350 			goto fail;
351 		slen = len * 2 + 1 + sizeof("BITS: ");
352 		if ((str = calloc(1, slen)) == NULL)
353 			goto fail;
354 		p = str;
355 		if (print_hint) {
356 			strlcpy(str, "BITS: ", slen);
357 			p += sizeof("BITS: ");
358 		}
359 		for (i = 0; i < len; i++) {
360 			snprintf(p, 3, "%02x", buf[i]);
361 			p += 2;
362 		}
363 		break;
364 	case BER_TYPE_OBJECT:
365 		if (ober_get_oid(root, &o) == -1)
366 			goto fail;
367 		if (asprintf(&str, "%s%s",
368 		    print_hint ? "OID: " : "",
369 		    smi_oid2string(&o, strbuf, sizeof(strbuf), lookup)) == -1)
370 			goto fail;
371 		break;
372 	case BER_TYPE_OCTETSTRING:
373 		if (ober_get_string(root, &buf) == -1)
374 			goto fail;
375 		if (root->be_class == BER_CLASS_APPLICATION &&
376 		    root->be_type == SNMP_T_IPADDR) {
377 			if (asprintf(&str, "%s%s",
378 			    print_hint ? "IpAddress: " : "",
379 			    inet_ntoa(*(struct in_addr *)buf)) == -1)
380 				goto fail;
381 		} else if (root->be_class == BER_CLASS_CONTEXT) {
382 			if (root->be_type == SNMP_E_NOSUCHOBJECT)
383 				str = strdup("No Such Object available on this "
384 				    "agent at this OID");
385 			else if (root->be_type == SNMP_E_NOSUCHINSTANCE)
386 				str = strdup("No Such Instance currently "
387 				    "exists at this OID");
388 			else if (root->be_type == SNMP_E_ENDOFMIB)
389 				str = strdup("No more variables left in this "
390 				    "MIB View (It is past the end of the MIB "
391 				    "tree)");
392 			else
393 				str = strdup("Unknown status at this OID");
394 		} else {
395 			if (object != NULL && object->o_textconv != NULL &&
396 			    object->o_textconv->tc_syntax == root->be_encoding)
397 				return smi_displayhint_os(object->o_textconv,
398 				    print_hint, buf, root->be_len, utf8);
399 			for (i = 0; i < root->be_len; i++) {
400 				if (!isprint(buf[i])) {
401 					if (output_string == smi_os_default)
402 						output_string = smi_os_hex;
403 					else if (output_string == smi_os_ascii)
404 						is_hex = 1;
405 					break;
406 				}
407 			}
408 			/*
409 			 * hex is 3 * n (2 digits + n - 1 spaces + NUL-byte)
410 			 * ascii can be max (2 * n) + 2 quotes + NUL-byte
411 			 */
412 			len = output_string == smi_os_hex ? 3 : 2;
413 			p = str = reallocarray(NULL, root->be_len + 2, len);
414 			if (p == NULL)
415 				goto fail;
416 			len *= root->be_len + 2;
417 			if (is_hex) {
418 				*str++ = '"';
419 				len--;
420 			}
421 			for (i = 0; i < root->be_len; i++) {
422 				switch (output_string) {
423 				case smi_os_default:
424 					/* FALLTHROUGH */
425 				case smi_os_ascii:
426 					/*
427 					 * There's probably more edgecases here,
428 					 * not fully investigated
429 					 */
430 					if (len < 2)
431 						goto fail;
432 					if (is_hex && buf[i] == '\\') {
433 						*str++ = '\\';
434 						len--;
435 					}
436 					*str++ = isprint(buf[i]) ? buf[i] : '.';
437 					len--;
438 					break;
439 				case smi_os_hex:
440 					ret = snprintf(str, len, "%s%02hhX",
441 					    i == 0 ? "" :
442 					    i % 16 == 0 ? "\n" : " ", buf[i]);
443 					if (ret == -1 || ret > (int) len)
444 						goto fail;
445 					len -= ret;
446 					str += ret;
447 					break;
448 				}
449 			}
450 			if (is_hex) {
451 				if (len < 2)
452 					goto fail;
453 				*str++ = '"';
454 				len--;
455 			}
456 			if (len == 0)
457 				goto fail;
458 			*str = '\0';
459 			str = NULL;
460 			if (asprintf(&str, "%s%s",
461 			    print_hint ?
462 			    output_string == smi_os_hex ? "Hex-STRING: " :
463 			    "STRING: " :
464 			    "", p) == -1) {
465 				free(p);
466 				goto fail;
467 			}
468 			free(p);
469 		}
470 		break;
471 	case BER_TYPE_NULL:	/* no payload */
472 	case BER_TYPE_EOC:
473 	case BER_TYPE_SEQUENCE:
474 	case BER_TYPE_SET:
475 	default:
476 		str = strdup("");
477 		break;
478 	}
479 
480 	return (str);
481 
482  fail:
483 	free(str);
484 	return (NULL);
485 }
486 
487 int
488 smi_string2oid(const char *oidstr, struct ber_oid *o)
489 {
490 	char			*sp, *p, str[BUFSIZ];
491 	const char		*errstr;
492 	struct oid		*oid;
493 	struct ber_oid		 ko;
494 
495 	if (strlcpy(str, oidstr, sizeof(str)) >= sizeof(str))
496 		return (-1);
497 	bzero(o, sizeof(*o));
498 
499 	/*
500 	 * Parse OID strings in the common form n.n.n or n-n-n.
501 	 * Based on ober_string2oid with additional support for symbolic names.
502 	 */
503 	p = sp = str[0] == '.' ? str + 1 : str;
504 	for (; p != NULL; sp = p) {
505 		if ((p = strpbrk(p, ".-")) != NULL)
506 			*p++ = '\0';
507 		if ((oid = smi_findkey(sp)) != NULL) {
508 			bcopy(&oid->o_id, &ko, sizeof(ko));
509 			if (o->bo_n && ober_oid_cmp(&ko, o) != 2)
510 				return (-1);
511 			bcopy(&ko, o, sizeof(*o));
512 			errstr = NULL;
513 		} else {
514 			o->bo_id[o->bo_n++] =
515 			    strtonum(sp, 0, UINT_MAX, &errstr);
516 		}
517 		if (errstr || o->bo_n > BER_MAX_OID_LEN)
518 			return (-1);
519 	}
520 
521 	return (0);
522 }
523 
524 unsigned int
525 smi_application(struct ber_element *elm)
526 {
527 	if (elm->be_class != BER_CLASS_APPLICATION)
528 		return (BER_TYPE_OCTETSTRING);
529 
530 	switch (elm->be_type) {
531 	case SNMP_T_IPADDR:
532 		return (BER_TYPE_OCTETSTRING);
533 	case SNMP_T_COUNTER32:
534 	case SNMP_T_GAUGE32:
535 	case SNMP_T_TIMETICKS:
536 	case SNMP_T_OPAQUE:
537 	case SNMP_T_COUNTER64:
538 		return (BER_TYPE_INTEGER);
539 	default:
540 		break;
541 	}
542 	return (BER_TYPE_OCTETSTRING);
543 
544 }
545 
546 char *
547 smi_oid2string(struct ber_oid *o, char *buf, size_t len,
548     enum smi_oid_lookup lookup)
549 {
550 	char		 str[256];
551 	struct oid	*value, key;
552 	size_t		 i;
553 
554 	bzero(buf, len);
555 	bzero(&key, sizeof(key));
556 	bcopy(o, &key.o_id, sizeof(struct ber_oid));
557 
558 	for (i = 0; i < o->bo_n; i++) {
559 		key.o_oidlen = i + 1;
560 		if (lookup != smi_oidl_numeric &&
561 		    (value = RB_FIND(oidtree, &smi_oidtree, &key)) != NULL) {
562 			snprintf(str, sizeof(str), "%s", value->o_name);
563 			if (lookup == smi_oidl_short && i + 1 < o->bo_n) {
564 				key.o_oidlen = i + 2;
565 				if (RB_FIND(oidtree, &smi_oidtree, &key) != NULL)
566 					continue;
567 			}
568 		} else
569 			snprintf(str, sizeof(str), "%u", key.o_oid[i]);
570 		if (*buf != '\0' || i == 0)
571 			strlcat(buf, ".", len);
572 		strlcat(buf, str, len);
573 	}
574 
575 	return (buf);
576 }
577 
578 void
579 smi_mibtree(struct oid *oids)
580 {
581 	size_t		 i;
582 
583 	for (i = 0; oids[i].o_name != NULL; i++) {
584 		RB_INSERT(oidtree, &smi_oidtree, &(oids[i]));
585 		RB_INSERT(keytree, &smi_keytree, &(oids[i]));
586 	}
587 }
588 
589 void
590 smi_textconvtree(struct textconv *textconvs)
591 {
592 	size_t		 i = 0;
593 
594 	for (i = 0; textconvs[i].tc_name != NULL; i++)
595 		RB_INSERT(textconvtree, &smi_tctree, &(textconvs[i]));
596 }
597 
598 struct oid *
599 smi_findkey(char *name)
600 {
601 	struct oid	oid;
602 	if (name == NULL)
603 		return (NULL);
604 	oid.o_name = name;
605 	return (RB_FIND(keytree, &smi_keytree, &oid));
606 }
607 
608 struct oid *
609 smi_foreach(struct oid *oid)
610 {
611 	/*
612 	 * Traverse the tree of MIBs with the option to check
613 	 * for specific OID flags.
614 	 */
615 	if (oid == NULL)
616 		return RB_MIN(oidtree, &smi_oidtree);
617 	return RB_NEXT(oidtree, &smi_oidtree, oid);
618 }
619 
620 char *
621 smi_displayhint_int(struct textconv *tc, int print_hint, long long v)
622 {
623 	size_t i;
624 	char *rbuf;
625 
626 	for (i = 0; tc->tc_enum[i].tce_name != NULL; i++) {
627 		if (tc->tc_enum[i].tce_number == v) {
628 			if (print_hint) {
629 				if (asprintf(&rbuf, "INTEGER: %s(%lld)",
630 				    tc->tc_enum[i].tce_name, v) == -1)
631 					return NULL;
632 			} else {
633 				if (asprintf(&rbuf, "%s",
634 				    tc->tc_enum[i].tce_name) == -1)
635 					return NULL;
636 			}
637 			return rbuf;
638 		}
639 	}
640 	if (asprintf(&rbuf, "%s%lld", print_hint ? "INTEGER: " : "", v) == -1)
641 		return NULL;
642 	return rbuf;
643 }
644 
645 #define REPLACEMENT "\357\277\275"
646 char *
647 smi_displayhint_os(struct textconv *tc, int print_hint, const char *src,
648     size_t srclen, int utf8)
649 {
650 	size_t octetlength, i = 0, j = 0;
651 	size_t prefixlen;
652 	unsigned long ulval;
653 	int clen;
654 	char *displayformat;
655 	const char *prefix;
656 	char *rbuf, *dst;
657 	wchar_t wc;
658 
659 	prefix = print_hint ? "STRING: " : "";
660 	prefixlen = strlen(prefix);
661 
662 	errno = 0;
663 	ulval = strtoul(tc->tc_display_hint, &displayformat, 10);
664 	octetlength = ulval;
665 	if (!isdigit(tc->tc_display_hint[0]) ||
666 	    (errno != 0 && (ulval == 0 || ulval == ULONG_MAX)) ||
667 	    (unsigned long) octetlength != ulval) {
668 		errno = EINVAL;
669 		return NULL;
670 	}
671 
672 	if (displayformat[0] == 't' || displayformat[0] == 'a') {
673 		if ((rbuf = malloc(prefixlen + octetlength + 1)) == NULL)
674 			return NULL;
675 		(void)strlcpy(rbuf, prefix, prefixlen + octetlength + 1);
676 		dst = rbuf + prefixlen;
677 		while (j < octetlength && i < srclen) {
678 			clen = mbtowc(&wc, &(src[i]), srclen - i);
679 			if (displayformat[0] == 'a' && clen > 1)
680 				clen = -1;
681 			switch (clen) {
682 			case 0:
683 				dst[j++] = '.';
684 				i++;
685 				break;
686 			case -1:
687 				mbtowc(NULL, NULL, MB_CUR_MAX);
688 				if (utf8) {
689 					if (octetlength - j <
690 					    sizeof(REPLACEMENT) - 1) {
691 						dst[j] = '\0';
692 						return rbuf;
693 					}
694 					memcpy(&(dst[j]), REPLACEMENT,
695 					    sizeof(REPLACEMENT) - 1);
696 					j += sizeof(REPLACEMENT) - 1;
697 				} else
698 					dst[j++] = '?';
699 				i++;
700 				break;
701 			default:
702 				if (!iswprint(wc) || (!utf8 && clen > 1))
703 					dst[j++] = '.';
704 				else if (octetlength - j < (size_t)clen) {
705 					dst[j] = '\0';
706 					return rbuf;
707 				} else {
708 					memcpy(&(dst[j]), &(src[i]), clen);
709 					j += clen;
710 				}
711 				i += clen;
712 				break;
713 			}
714 		}
715 		dst[j] = '\0';
716 		return rbuf;
717 	}
718 	errno = EINVAL;
719 	return NULL;
720 }
721 
722 int
723 smi_oid_cmp(struct oid *a, struct oid *b)
724 {
725 	size_t	 i;
726 
727 	for (i = 0; i < MINIMUM(a->o_oidlen, b->o_oidlen); i++) {
728 		if (a->o_oid[i] != b->o_oid[i])
729 			return (a->o_oid[i] - b->o_oid[i]);
730 	}
731 
732 	return (a->o_oidlen - b->o_oidlen);
733 }
734 
735 int
736 smi_key_cmp(struct oid *a, struct oid *b)
737 {
738 	if (a->o_name == NULL || b->o_name == NULL)
739 		return (-1);
740 	return (strcasecmp(a->o_name, b->o_name));
741 }
742 
743 int
744 smi_textconv_cmp(struct textconv *a, struct textconv *b)
745 {
746 	return strcmp(a->tc_name, b->tc_name);
747 }
748 
749 RB_GENERATE(oidtree, oid, o_element, smi_oid_cmp)
750 RB_GENERATE(keytree, oid, o_keyword, smi_key_cmp)
751 RB_GENERATE(textconvtree, textconv, tc_entry, smi_textconv_cmp);
752