1 /**
2 * @file
3 * SNMP output message processing (RFC1157).
4 *
5 * Output responses and traps are build in two passes:
6 *
7 * Pass 0: iterate over the output message backwards to determine encoding lengths
8 * Pass 1: the actual forward encoding of internal form into ASN1
9 *
10 * The single-pass encoding method described by Comer & Stevens
11 * requires extra buffer space and copying for reversal of the packet.
12 * The buffer requirement can be prohibitively large for big payloads
13 * (>= 484) therefore we use the two encoding passes.
14 */
15
16 /*
17 * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
18 * All rights reserved.
19 *
20 * Redistribution and use in source and binary forms, with or without modification,
21 * are permitted provided that the following conditions are met:
22 *
23 * 1. Redistributions of source code must retain the above copyright notice,
24 * this list of conditions and the following disclaimer.
25 * 2. Redistributions in binary form must reproduce the above copyright notice,
26 * this list of conditions and the following disclaimer in the documentation
27 * and/or other materials provided with the distribution.
28 * 3. The name of the author may not be used to endorse or promote products
29 * derived from this software without specific prior written permission.
30 *
31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
32 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
33 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
34 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
35 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
36 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
37 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
38 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
39 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
40 * OF SUCH DAMAGE.
41 *
42 * Author: Christiaan Simons <christiaan.simons@axon.tv>
43 */
44
45 #include "lwip/opt.h"
46
47 #if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */
48
49 #include "lwip/udp.h"
50 #include "lwip/netif.h"
51 #include "lwip/snmp.h"
52 #include "lwip/snmp_asn1.h"
53 #include "lwip/snmp_msg.h"
54
55 struct snmp_trap_dst
56 {
57 /* destination IP address in network order */
58 ip_addr_t dip;
59 /* set to 0 when disabled, >0 when enabled */
60 u8_t enable;
61 };
62 struct snmp_trap_dst trap_dst[SNMP_TRAP_DESTINATIONS];
63
64 /** TRAP message structure */
65 struct snmp_msg_trap trap_msg;
66
67 static u16_t snmp_resp_header_sum(struct snmp_msg_pstat *m_stat, u16_t vb_len);
68 static u16_t snmp_trap_header_sum(struct snmp_msg_trap *m_trap, u16_t vb_len);
69 static u16_t snmp_varbind_list_sum(struct snmp_varbind_root *root);
70
71 static u16_t snmp_resp_header_enc(struct snmp_msg_pstat *m_stat, struct pbuf *p);
72 static u16_t snmp_trap_header_enc(struct snmp_msg_trap *m_trap, struct pbuf *p);
73 static u16_t snmp_varbind_list_enc(struct snmp_varbind_root *root, struct pbuf *p, u16_t ofs);
74
75 /**
76 * Sets enable switch for this trap destination.
77 * @param dst_idx index in 0 .. SNMP_TRAP_DESTINATIONS-1
78 * @param enable switch if 0 destination is disabled >0 enabled.
79 */
80 void
snmp_trap_dst_enable(u8_t dst_idx,u8_t enable)81 snmp_trap_dst_enable(u8_t dst_idx, u8_t enable)
82 {
83 if (dst_idx < SNMP_TRAP_DESTINATIONS)
84 {
85 trap_dst[dst_idx].enable = enable;
86 }
87 }
88
89 /**
90 * Sets IPv4 address for this trap destination.
91 * @param dst_idx index in 0 .. SNMP_TRAP_DESTINATIONS-1
92 * @param dst IPv4 address in host order.
93 */
94 void
snmp_trap_dst_ip_set(u8_t dst_idx,ip_addr_t * dst)95 snmp_trap_dst_ip_set(u8_t dst_idx, ip_addr_t *dst)
96 {
97 if (dst_idx < SNMP_TRAP_DESTINATIONS)
98 {
99 ip_addr_set(&trap_dst[dst_idx].dip, dst);
100 }
101 }
102
103 /**
104 * Sends a 'getresponse' message to the request originator.
105 *
106 * @param m_stat points to the current message request state source
107 * @return ERR_OK when success, ERR_MEM if we're out of memory
108 *
109 * @note the caller is responsible for filling in outvb in the m_stat
110 * and provide error-status and index (except for tooBig errors) ...
111 */
112 err_t
snmp_send_response(struct snmp_msg_pstat * m_stat)113 snmp_send_response(struct snmp_msg_pstat *m_stat)
114 {
115 struct snmp_varbind_root emptyvb = {NULL, NULL, 0, 0, 0};
116 struct pbuf *p;
117 u16_t tot_len;
118 err_t err;
119
120 /* pass 0, calculate length fields */
121 tot_len = snmp_varbind_list_sum(&m_stat->outvb);
122 tot_len = snmp_resp_header_sum(m_stat, tot_len);
123
124 /* try allocating pbuf(s) for complete response */
125 p = pbuf_alloc(PBUF_TRANSPORT, tot_len, PBUF_POOL);
126 if (p == NULL)
127 {
128 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_snd_response() tooBig\n"));
129
130 /* can't construct reply, return error-status tooBig */
131 m_stat->error_status = SNMP_ES_TOOBIG;
132 m_stat->error_index = 0;
133 /* pass 0, recalculate lengths, for empty varbind-list */
134 tot_len = snmp_varbind_list_sum(&emptyvb);
135 tot_len = snmp_resp_header_sum(m_stat, tot_len);
136 /* retry allocation once for header and empty varbind-list */
137 p = pbuf_alloc(PBUF_TRANSPORT, tot_len, PBUF_POOL);
138 }
139 if (p != NULL)
140 {
141 /* first pbuf alloc try or retry alloc success */
142 u16_t ofs;
143
144 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_snd_response() p != NULL\n"));
145
146 /* pass 1, size error, encode packet ino the pbuf(s) */
147 ofs = snmp_resp_header_enc(m_stat, p);
148 snmp_varbind_list_enc(&m_stat->outvb, p, ofs);
149
150 switch (m_stat->error_status)
151 {
152 case SNMP_ES_TOOBIG:
153 snmp_inc_snmpouttoobigs();
154 break;
155 case SNMP_ES_NOSUCHNAME:
156 snmp_inc_snmpoutnosuchnames();
157 break;
158 case SNMP_ES_BADVALUE:
159 snmp_inc_snmpoutbadvalues();
160 break;
161 case SNMP_ES_GENERROR:
162 snmp_inc_snmpoutgenerrs();
163 break;
164 }
165 snmp_inc_snmpoutgetresponses();
166 snmp_inc_snmpoutpkts();
167
168 /** @todo do we need separate rx and tx pcbs for threaded case? */
169 /** connect to the originating source */
170 udp_connect(m_stat->pcb, &m_stat->sip, m_stat->sp);
171 err = udp_send(m_stat->pcb, p);
172 if (err == ERR_MEM)
173 {
174 /** @todo release some memory, retry and return tooBig? tooMuchHassle? */
175 err = ERR_MEM;
176 }
177 else
178 {
179 err = ERR_OK;
180 }
181 /** disassociate remote address and port with this pcb */
182 udp_disconnect(m_stat->pcb);
183
184 pbuf_free(p);
185 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_snd_response() done\n"));
186 return err;
187 }
188 else
189 {
190 /* first pbuf alloc try or retry alloc failed
191 very low on memory, couldn't return tooBig */
192 return ERR_MEM;
193 }
194 }
195
196
197 /**
198 * Sends an generic or enterprise specific trap message.
199 *
200 * @param generic_trap is the trap code
201 * @param eoid points to enterprise object identifier
202 * @param specific_trap used for enterprise traps when generic_trap == 6
203 * @return ERR_OK when success, ERR_MEM if we're out of memory
204 *
205 * @note the caller is responsible for filling in outvb in the trap_msg
206 * @note the use of the enterpise identifier field
207 * is per RFC1215.
208 * Use .iso.org.dod.internet.mgmt.mib-2.snmp for generic traps
209 * and .iso.org.dod.internet.private.enterprises.yourenterprise
210 * (sysObjectID) for specific traps.
211 */
212 err_t
snmp_send_trap(s8_t generic_trap,struct snmp_obj_id * eoid,s32_t specific_trap)213 snmp_send_trap(s8_t generic_trap, struct snmp_obj_id *eoid, s32_t specific_trap)
214 {
215 struct snmp_trap_dst *td;
216 struct netif *dst_if;
217 ip_addr_t dst_ip;
218 struct pbuf *p;
219 u16_t i,tot_len;
220
221 for (i=0, td = &trap_dst[0]; i<SNMP_TRAP_DESTINATIONS; i++, td++)
222 {
223 if ((td->enable != 0) && !ip_addr_isany(&td->dip))
224 {
225 /* network order trap destination */
226 ip_addr_copy(trap_msg.dip, td->dip);
227 /* lookup current source address for this dst */
228 dst_if = ip_route(&td->dip);
229 ip_addr_copy(dst_ip, dst_if->ip_addr);
230 /* @todo: what about IPv6? */
231 trap_msg.sip_raw[0] = ip4_addr1(&dst_ip);
232 trap_msg.sip_raw[1] = ip4_addr2(&dst_ip);
233 trap_msg.sip_raw[2] = ip4_addr3(&dst_ip);
234 trap_msg.sip_raw[3] = ip4_addr4(&dst_ip);
235 trap_msg.gen_trap = generic_trap;
236 trap_msg.spc_trap = specific_trap;
237 if (generic_trap == SNMP_GENTRAP_ENTERPRISESPC)
238 {
239 /* enterprise-Specific trap */
240 trap_msg.enterprise = eoid;
241 }
242 else
243 {
244 /* generic (MIB-II) trap */
245 snmp_get_snmpgrpid_ptr(&trap_msg.enterprise);
246 }
247 snmp_get_sysuptime(&trap_msg.ts);
248
249 /* pass 0, calculate length fields */
250 tot_len = snmp_varbind_list_sum(&trap_msg.outvb);
251 tot_len = snmp_trap_header_sum(&trap_msg, tot_len);
252
253 /* allocate pbuf(s) */
254 p = pbuf_alloc(PBUF_TRANSPORT, tot_len, PBUF_POOL);
255 if (p != NULL)
256 {
257 u16_t ofs;
258
259 /* pass 1, encode packet ino the pbuf(s) */
260 ofs = snmp_trap_header_enc(&trap_msg, p);
261 snmp_varbind_list_enc(&trap_msg.outvb, p, ofs);
262
263 snmp_inc_snmpouttraps();
264 snmp_inc_snmpoutpkts();
265
266 /** send to the TRAP destination */
267 udp_sendto(trap_msg.pcb, p, &trap_msg.dip, SNMP_TRAP_PORT);
268
269 pbuf_free(p);
270 }
271 else
272 {
273 return ERR_MEM;
274 }
275 }
276 }
277 return ERR_OK;
278 }
279
280 void
snmp_coldstart_trap(void)281 snmp_coldstart_trap(void)
282 {
283 trap_msg.outvb.head = NULL;
284 trap_msg.outvb.tail = NULL;
285 trap_msg.outvb.count = 0;
286 snmp_send_trap(SNMP_GENTRAP_COLDSTART, NULL, 0);
287 }
288
289 void
snmp_authfail_trap(void)290 snmp_authfail_trap(void)
291 {
292 u8_t enable;
293 snmp_get_snmpenableauthentraps(&enable);
294 if (enable == 1)
295 {
296 trap_msg.outvb.head = NULL;
297 trap_msg.outvb.tail = NULL;
298 trap_msg.outvb.count = 0;
299 snmp_send_trap(SNMP_GENTRAP_AUTHFAIL, NULL, 0);
300 }
301 }
302
303 /**
304 * Sums response header field lengths from tail to head and
305 * returns resp_header_lengths for second encoding pass.
306 *
307 * @param vb_len varbind-list length
308 * @param rhl points to returned header lengths
309 * @return the required lenght for encoding the response header
310 */
311 static u16_t
snmp_resp_header_sum(struct snmp_msg_pstat * m_stat,u16_t vb_len)312 snmp_resp_header_sum(struct snmp_msg_pstat *m_stat, u16_t vb_len)
313 {
314 u16_t tot_len;
315 struct snmp_resp_header_lengths *rhl;
316
317 rhl = &m_stat->rhl;
318 tot_len = vb_len;
319 snmp_asn1_enc_s32t_cnt(m_stat->error_index, &rhl->erridxlen);
320 snmp_asn1_enc_length_cnt(rhl->erridxlen, &rhl->erridxlenlen);
321 tot_len += 1 + rhl->erridxlenlen + rhl->erridxlen;
322
323 snmp_asn1_enc_s32t_cnt(m_stat->error_status, &rhl->errstatlen);
324 snmp_asn1_enc_length_cnt(rhl->errstatlen, &rhl->errstatlenlen);
325 tot_len += 1 + rhl->errstatlenlen + rhl->errstatlen;
326
327 snmp_asn1_enc_s32t_cnt(m_stat->rid, &rhl->ridlen);
328 snmp_asn1_enc_length_cnt(rhl->ridlen, &rhl->ridlenlen);
329 tot_len += 1 + rhl->ridlenlen + rhl->ridlen;
330
331 rhl->pdulen = tot_len;
332 snmp_asn1_enc_length_cnt(rhl->pdulen, &rhl->pdulenlen);
333 tot_len += 1 + rhl->pdulenlen;
334
335 rhl->comlen = m_stat->com_strlen;
336 snmp_asn1_enc_length_cnt(rhl->comlen, &rhl->comlenlen);
337 tot_len += 1 + rhl->comlenlen + rhl->comlen;
338
339 snmp_asn1_enc_s32t_cnt(snmp_version, &rhl->verlen);
340 snmp_asn1_enc_length_cnt(rhl->verlen, &rhl->verlenlen);
341 tot_len += 1 + rhl->verlen + rhl->verlenlen;
342
343 rhl->seqlen = tot_len;
344 snmp_asn1_enc_length_cnt(rhl->seqlen, &rhl->seqlenlen);
345 tot_len += 1 + rhl->seqlenlen;
346
347 return tot_len;
348 }
349
350 /**
351 * Sums trap header field lengths from tail to head and
352 * returns trap_header_lengths for second encoding pass.
353 *
354 * @param vb_len varbind-list length
355 * @param thl points to returned header lengths
356 * @return the required lenght for encoding the trap header
357 */
358 static u16_t
snmp_trap_header_sum(struct snmp_msg_trap * m_trap,u16_t vb_len)359 snmp_trap_header_sum(struct snmp_msg_trap *m_trap, u16_t vb_len)
360 {
361 u16_t tot_len;
362 struct snmp_trap_header_lengths *thl;
363
364 thl = &m_trap->thl;
365 tot_len = vb_len;
366
367 snmp_asn1_enc_u32t_cnt(m_trap->ts, &thl->tslen);
368 snmp_asn1_enc_length_cnt(thl->tslen, &thl->tslenlen);
369 tot_len += 1 + thl->tslen + thl->tslenlen;
370
371 snmp_asn1_enc_s32t_cnt(m_trap->spc_trap, &thl->strplen);
372 snmp_asn1_enc_length_cnt(thl->strplen, &thl->strplenlen);
373 tot_len += 1 + thl->strplen + thl->strplenlen;
374
375 snmp_asn1_enc_s32t_cnt(m_trap->gen_trap, &thl->gtrplen);
376 snmp_asn1_enc_length_cnt(thl->gtrplen, &thl->gtrplenlen);
377 tot_len += 1 + thl->gtrplen + thl->gtrplenlen;
378
379 thl->aaddrlen = 4;
380 snmp_asn1_enc_length_cnt(thl->aaddrlen, &thl->aaddrlenlen);
381 tot_len += 1 + thl->aaddrlen + thl->aaddrlenlen;
382
383 snmp_asn1_enc_oid_cnt(m_trap->enterprise->len, &m_trap->enterprise->id[0], &thl->eidlen);
384 snmp_asn1_enc_length_cnt(thl->eidlen, &thl->eidlenlen);
385 tot_len += 1 + thl->eidlen + thl->eidlenlen;
386
387 thl->pdulen = tot_len;
388 snmp_asn1_enc_length_cnt(thl->pdulen, &thl->pdulenlen);
389 tot_len += 1 + thl->pdulenlen;
390
391 thl->comlen = sizeof(snmp_publiccommunity) - 1;
392 snmp_asn1_enc_length_cnt(thl->comlen, &thl->comlenlen);
393 tot_len += 1 + thl->comlenlen + thl->comlen;
394
395 snmp_asn1_enc_s32t_cnt(snmp_version, &thl->verlen);
396 snmp_asn1_enc_length_cnt(thl->verlen, &thl->verlenlen);
397 tot_len += 1 + thl->verlen + thl->verlenlen;
398
399 thl->seqlen = tot_len;
400 snmp_asn1_enc_length_cnt(thl->seqlen, &thl->seqlenlen);
401 tot_len += 1 + thl->seqlenlen;
402
403 return tot_len;
404 }
405
406 /**
407 * Sums varbind lengths from tail to head and
408 * annotates lengths in varbind for second encoding pass.
409 *
410 * @param root points to the root of the variable binding list
411 * @return the required lenght for encoding the variable bindings
412 */
413 static u16_t
snmp_varbind_list_sum(struct snmp_varbind_root * root)414 snmp_varbind_list_sum(struct snmp_varbind_root *root)
415 {
416 struct snmp_varbind *vb;
417 u32_t *uint_ptr;
418 s32_t *sint_ptr;
419 u16_t tot_len;
420
421 tot_len = 0;
422 vb = root->tail;
423 while ( vb != NULL )
424 {
425 /* encoded value lenght depends on type */
426 switch (vb->value_type)
427 {
428 case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG):
429 sint_ptr = (s32_t*)vb->value;
430 snmp_asn1_enc_s32t_cnt(*sint_ptr, &vb->vlen);
431 break;
432 case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_COUNTER):
433 case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_GAUGE):
434 case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS):
435 uint_ptr = (u32_t*)vb->value;
436 snmp_asn1_enc_u32t_cnt(*uint_ptr, &vb->vlen);
437 break;
438 case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR):
439 case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL):
440 case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR):
441 case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE):
442 vb->vlen = vb->value_len;
443 break;
444 case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID):
445 sint_ptr = (s32_t*)vb->value;
446 snmp_asn1_enc_oid_cnt(vb->value_len / sizeof(s32_t), sint_ptr, &vb->vlen);
447 break;
448 default:
449 /* unsupported type */
450 vb->vlen = 0;
451 break;
452 };
453 /* encoding length of value length field */
454 snmp_asn1_enc_length_cnt(vb->vlen, &vb->vlenlen);
455 snmp_asn1_enc_oid_cnt(vb->ident_len, vb->ident, &vb->olen);
456 snmp_asn1_enc_length_cnt(vb->olen, &vb->olenlen);
457
458 vb->seqlen = 1 + vb->vlenlen + vb->vlen;
459 vb->seqlen += 1 + vb->olenlen + vb->olen;
460 snmp_asn1_enc_length_cnt(vb->seqlen, &vb->seqlenlen);
461
462 /* varbind seq */
463 tot_len += 1 + vb->seqlenlen + vb->seqlen;
464
465 vb = vb->prev;
466 }
467
468 /* varbind-list seq */
469 root->seqlen = tot_len;
470 snmp_asn1_enc_length_cnt(root->seqlen, &root->seqlenlen);
471 tot_len += 1 + root->seqlenlen;
472
473 return tot_len;
474 }
475
476 /**
477 * Encodes response header from head to tail.
478 */
479 static u16_t
snmp_resp_header_enc(struct snmp_msg_pstat * m_stat,struct pbuf * p)480 snmp_resp_header_enc(struct snmp_msg_pstat *m_stat, struct pbuf *p)
481 {
482 u16_t ofs;
483
484 ofs = 0;
485 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
486 ofs += 1;
487 snmp_asn1_enc_length(p, ofs, m_stat->rhl.seqlen);
488 ofs += m_stat->rhl.seqlenlen;
489
490 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
491 ofs += 1;
492 snmp_asn1_enc_length(p, ofs, m_stat->rhl.verlen);
493 ofs += m_stat->rhl.verlenlen;
494 snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.verlen, snmp_version);
495 ofs += m_stat->rhl.verlen;
496
497 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR));
498 ofs += 1;
499 snmp_asn1_enc_length(p, ofs, m_stat->rhl.comlen);
500 ofs += m_stat->rhl.comlenlen;
501 snmp_asn1_enc_raw(p, ofs, m_stat->rhl.comlen, m_stat->community);
502 ofs += m_stat->rhl.comlen;
503
504 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_RESP));
505 ofs += 1;
506 snmp_asn1_enc_length(p, ofs, m_stat->rhl.pdulen);
507 ofs += m_stat->rhl.pdulenlen;
508
509 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
510 ofs += 1;
511 snmp_asn1_enc_length(p, ofs, m_stat->rhl.ridlen);
512 ofs += m_stat->rhl.ridlenlen;
513 snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.ridlen, m_stat->rid);
514 ofs += m_stat->rhl.ridlen;
515
516 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
517 ofs += 1;
518 snmp_asn1_enc_length(p, ofs, m_stat->rhl.errstatlen);
519 ofs += m_stat->rhl.errstatlenlen;
520 snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.errstatlen, m_stat->error_status);
521 ofs += m_stat->rhl.errstatlen;
522
523 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
524 ofs += 1;
525 snmp_asn1_enc_length(p, ofs, m_stat->rhl.erridxlen);
526 ofs += m_stat->rhl.erridxlenlen;
527 snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.erridxlen, m_stat->error_index);
528 ofs += m_stat->rhl.erridxlen;
529
530 return ofs;
531 }
532
533 /**
534 * Encodes trap header from head to tail.
535 */
536 static u16_t
snmp_trap_header_enc(struct snmp_msg_trap * m_trap,struct pbuf * p)537 snmp_trap_header_enc(struct snmp_msg_trap *m_trap, struct pbuf *p)
538 {
539 u16_t ofs;
540
541 ofs = 0;
542 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
543 ofs += 1;
544 snmp_asn1_enc_length(p, ofs, m_trap->thl.seqlen);
545 ofs += m_trap->thl.seqlenlen;
546
547 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
548 ofs += 1;
549 snmp_asn1_enc_length(p, ofs, m_trap->thl.verlen);
550 ofs += m_trap->thl.verlenlen;
551 snmp_asn1_enc_s32t(p, ofs, m_trap->thl.verlen, snmp_version);
552 ofs += m_trap->thl.verlen;
553
554 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR));
555 ofs += 1;
556 snmp_asn1_enc_length(p, ofs, m_trap->thl.comlen);
557 ofs += m_trap->thl.comlenlen;
558 snmp_asn1_enc_raw(p, ofs, m_trap->thl.comlen, (u8_t *)&snmp_publiccommunity[0]);
559 ofs += m_trap->thl.comlen;
560
561 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_TRAP));
562 ofs += 1;
563 snmp_asn1_enc_length(p, ofs, m_trap->thl.pdulen);
564 ofs += m_trap->thl.pdulenlen;
565
566 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID));
567 ofs += 1;
568 snmp_asn1_enc_length(p, ofs, m_trap->thl.eidlen);
569 ofs += m_trap->thl.eidlenlen;
570 snmp_asn1_enc_oid(p, ofs, m_trap->enterprise->len, &m_trap->enterprise->id[0]);
571 ofs += m_trap->thl.eidlen;
572
573 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR));
574 ofs += 1;
575 snmp_asn1_enc_length(p, ofs, m_trap->thl.aaddrlen);
576 ofs += m_trap->thl.aaddrlenlen;
577 snmp_asn1_enc_raw(p, ofs, m_trap->thl.aaddrlen, &m_trap->sip_raw[0]);
578 ofs += m_trap->thl.aaddrlen;
579
580 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
581 ofs += 1;
582 snmp_asn1_enc_length(p, ofs, m_trap->thl.gtrplen);
583 ofs += m_trap->thl.gtrplenlen;
584 snmp_asn1_enc_u32t(p, ofs, m_trap->thl.gtrplen, m_trap->gen_trap);
585 ofs += m_trap->thl.gtrplen;
586
587 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
588 ofs += 1;
589 snmp_asn1_enc_length(p, ofs, m_trap->thl.strplen);
590 ofs += m_trap->thl.strplenlen;
591 snmp_asn1_enc_u32t(p, ofs, m_trap->thl.strplen, m_trap->spc_trap);
592 ofs += m_trap->thl.strplen;
593
594 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS));
595 ofs += 1;
596 snmp_asn1_enc_length(p, ofs, m_trap->thl.tslen);
597 ofs += m_trap->thl.tslenlen;
598 snmp_asn1_enc_u32t(p, ofs, m_trap->thl.tslen, m_trap->ts);
599 ofs += m_trap->thl.tslen;
600
601 return ofs;
602 }
603
604 /**
605 * Encodes varbind list from head to tail.
606 */
607 static u16_t
snmp_varbind_list_enc(struct snmp_varbind_root * root,struct pbuf * p,u16_t ofs)608 snmp_varbind_list_enc(struct snmp_varbind_root *root, struct pbuf *p, u16_t ofs)
609 {
610 struct snmp_varbind *vb;
611 s32_t *sint_ptr;
612 u32_t *uint_ptr;
613 u8_t *raw_ptr;
614
615 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
616 ofs += 1;
617 snmp_asn1_enc_length(p, ofs, root->seqlen);
618 ofs += root->seqlenlen;
619
620 vb = root->head;
621 while ( vb != NULL )
622 {
623 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
624 ofs += 1;
625 snmp_asn1_enc_length(p, ofs, vb->seqlen);
626 ofs += vb->seqlenlen;
627
628 snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID));
629 ofs += 1;
630 snmp_asn1_enc_length(p, ofs, vb->olen);
631 ofs += vb->olenlen;
632 snmp_asn1_enc_oid(p, ofs, vb->ident_len, &vb->ident[0]);
633 ofs += vb->olen;
634
635 snmp_asn1_enc_type(p, ofs, vb->value_type);
636 ofs += 1;
637 snmp_asn1_enc_length(p, ofs, vb->vlen);
638 ofs += vb->vlenlen;
639
640 switch (vb->value_type)
641 {
642 case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG):
643 sint_ptr = (s32_t*)vb->value;
644 snmp_asn1_enc_s32t(p, ofs, vb->vlen, *sint_ptr);
645 break;
646 case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_COUNTER):
647 case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_GAUGE):
648 case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS):
649 uint_ptr = (u32_t*)vb->value;
650 snmp_asn1_enc_u32t(p, ofs, vb->vlen, *uint_ptr);
651 break;
652 case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR):
653 case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR):
654 case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE):
655 raw_ptr = (u8_t*)vb->value;
656 snmp_asn1_enc_raw(p, ofs, vb->vlen, raw_ptr);
657 break;
658 case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL):
659 break;
660 case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID):
661 sint_ptr = (s32_t*)vb->value;
662 snmp_asn1_enc_oid(p, ofs, vb->value_len / sizeof(s32_t), sint_ptr);
663 break;
664 default:
665 /* unsupported type */
666 break;
667 };
668 ofs += vb->vlen;
669 vb = vb->next;
670 }
671 return ofs;
672 }
673
674 #endif /* LWIP_SNMP */
675