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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [Common/] [ethernet/] [lwIP/] [core/] [snmp/] [msg_in.c] - Blame information for rev 606

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Line No. Rev Author Line
1 606 jeremybenn 
/**
2 
 * @file
3 
 * SNMP input message processing (RFC1157).
4 
 */
5 
 
6 
/*
7 
 * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
8 
 * All rights reserved.
9 
 *
10 
 * Redistribution and use in source and binary forms, with or without modification,
11 
 * are permitted provided that the following conditions are met:
12 
 *
13 
 * 1. Redistributions of source code must retain the above copyright notice,
14 
 *    this list of conditions and the following disclaimer.
15 
 * 2. Redistributions in binary form must reproduce the above copyright notice,
16 
 *    this list of conditions and the following disclaimer in the documentation
17 
 *    and/or other materials provided with the distribution.
18 
 * 3. The name of the author may not be used to endorse or promote products
19 
 *    derived from this software without specific prior written permission.
20 
 *
21 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
22 
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
23 
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
24 
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25 
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
26 
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
29 
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
30 
 * OF SUCH DAMAGE.
31 
 *
32 
 * Author: Christiaan Simons <christiaan.simons@axon.tv>
33 
 */
34 
 
35 
#include "lwip/opt.h"
36 
 
37 
#if LWIP_SNMP
38 
#include <string.h>
39 
#include "arch/cc.h"
40 
#include "lwip/ip_addr.h"
41 
#include "lwip/mem.h"
42 
#include "lwip/udp.h"
43 
#include "lwip/stats.h"
44 
 
45 
#include "lwip/snmp.h"
46 
#include "lwip/snmp_asn1.h"
47 
#include "lwip/snmp_msg.h"
48 
#include "lwip/snmp_structs.h"
49 
 
50 
 
51 
/* public (non-static) constants */
52 
/** SNMP v1 == 0 */
53 
const s32_t snmp_version = 0;
54 
/** default SNMP community string */
55 
const char snmp_publiccommunity[7] = "public";
56 
 
57 
/* statically allocated buffers for SNMP_CONCURRENT_REQUESTS */
58 
#if (SNMP_CONCURRENT_REQUESTS == 0)
59 
#error "need at least one snmp_msg_pstat"
60 
#endif
61 
struct snmp_msg_pstat msg_input_list[SNMP_CONCURRENT_REQUESTS];
62 
/* UDP Protocol Control Block */
63 
struct udp_pcb *snmp1_pcb = NULL;
64 
 
65 
static void snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port);
66 
static err_t snmp_pdu_header_check(struct pbuf *p, u16_t ofs, u16_t pdu_len, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat);
67 
static err_t snmp_pdu_dec_varbindlist(struct pbuf *p, u16_t ofs, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat);
68 
 
69 
 
70 
/**
71 
 * Starts SNMP Agent.
72 
 * Allocates UDP pcb and binds it to IP_ADDR_ANY port 161.
73 
 */
74 
void
75 
snmp_init(void)
76 
{
77 
  struct snmp_msg_pstat *msg_ps;
78 
  u8_t i;
79 
 
80 
  snmp1_pcb = udp_new();
81 
  if (snmp1_pcb != NULL)
82 
  {
83 
    udp_recv(snmp1_pcb, snmp_recv, (void *)SNMP_IN_PORT);
84 
    udp_bind(snmp1_pcb, IP_ADDR_ANY, SNMP_IN_PORT);
85 
  }
86 
  msg_ps = &msg_input_list[0];
87 
  for (i=0; i<SNMP_CONCURRENT_REQUESTS; i++)
88 
  {
89 
    msg_ps->state = SNMP_MSG_EMPTY;
90 
    msg_ps->error_index = 0;
91 
    msg_ps->error_status = SNMP_ES_NOERROR;
92 
    msg_ps++;
93 
  }
94 
  trap_msg.pcb = snmp1_pcb;
95 
  /* The coldstart trap will only be output
96 
     if our outgoing interface is up & configured  */
97 
  snmp_coldstart_trap();
98 
}
99 
 
100 
static void
101 
snmp_error_response(struct snmp_msg_pstat *msg_ps, u8_t error)
102 
{
103 
  snmp_varbind_list_free(&msg_ps->outvb);
104 
  msg_ps->outvb = msg_ps->invb;
105 
  msg_ps->invb.head = NULL;
106 
  msg_ps->invb.tail = NULL;
107 
  msg_ps->invb.count = 0;
108 
  msg_ps->error_status = error;
109 
  msg_ps->error_index = 1 + msg_ps->vb_idx;
110 
  snmp_send_response(msg_ps);
111 
  snmp_varbind_list_free(&msg_ps->outvb);
112 
  msg_ps->state = SNMP_MSG_EMPTY;
113 
}
114 
 
115 
static void
116 
snmp_ok_response(struct snmp_msg_pstat *msg_ps)
117 
{
118 
  err_t err_ret;
119 
 
120 
  err_ret = snmp_send_response(msg_ps);
121 
  if (err_ret == ERR_MEM)
122 
  {
123 
    /* serious memory problem, can't return tooBig */
124 
#if LWIP_STATS
125 
    LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event pbufs.used = %"U16_F"\n",lwip_stats.pbuf.used));
126 
#endif
127 
  }
128 
  else
129 
  {
130 
    LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event = %"S32_F"\n",msg_ps->error_status));
131 
  }
132 
  /* free varbinds (if available) */
133 
  snmp_varbind_list_free(&msg_ps->invb);
134 
  snmp_varbind_list_free(&msg_ps->outvb);
135 
  msg_ps->state = SNMP_MSG_EMPTY;
136 
}
137 
 
138 
/**
139 
 * Service an internal or external event for SNMP GET.
140 
 *
141 
 * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1)
142 
 * @param msg_ps points to the assosicated message process state
143 
 */
144 
static void
145 
snmp_msg_get_event(u8_t request_id, struct snmp_msg_pstat *msg_ps)
146 
{
147 
  LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_get_event: msg_ps->state==%"U16_F"\n",(u16_t)msg_ps->state));
148 
 
149 
  if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF)
150 
  {
151 
    struct mib_external_node *en;
152 
    struct snmp_name_ptr np;
153 
 
154 
    /* get_object_def() answer*/
155 
    en = msg_ps->ext_mib_node;
156 
    np = msg_ps->ext_name_ptr;
157 
 
158 
    /* translate answer into a known lifeform */
159 
    en->get_object_def_a(request_id, np.ident_len, np.ident, &msg_ps->ext_object_def);
160 
    if (msg_ps->ext_object_def.instance != MIB_OBJECT_NONE)
161 
    {
162 
      msg_ps->state = SNMP_MSG_EXTERNAL_GET_VALUE;
163 
      en->get_value_q(request_id, &msg_ps->ext_object_def);
164 
    }
165 
    else
166 
    {
167 
      en->get_object_def_pc(request_id, np.ident_len, np.ident);
168 
      /* search failed, object id points to unknown object (nosuchname) */
169 
      snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME);
170 
    }
171 
  }
172 
  else if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_VALUE)
173 
  {
174 
    struct mib_external_node *en;
175 
    struct snmp_varbind *vb;
176 
 
177 
    /* get_value() answer */
178 
    en = msg_ps->ext_mib_node;
179 
 
180 
    /* allocate output varbind */
181 
    vb = (struct snmp_varbind *)mem_malloc(sizeof(struct snmp_varbind));
182 
    LWIP_ASSERT("vb != NULL",vb != NULL);
183 
    if (vb != NULL)
184 
    {
185 
      vb->next = NULL;
186 
      vb->prev = NULL;
187 
 
188 
      /* move name from invb to outvb */
189 
      vb->ident = msg_ps->vb_ptr->ident;
190 
      vb->ident_len = msg_ps->vb_ptr->ident_len;
191 
      /* ensure this memory is refereced once only */
192 
      msg_ps->vb_ptr->ident = NULL;
193 
      msg_ps->vb_ptr->ident_len = 0;
194 
 
195 
      vb->value_type = msg_ps->ext_object_def.asn_type;
196 
      vb->value_len =  msg_ps->ext_object_def.v_len;
197 
      if (vb->value_len > 0)
198 
      {
199 
        vb->value = mem_malloc(vb->value_len);
200 
        LWIP_ASSERT("vb->value != NULL",vb->value != NULL);
201 
        if (vb->value != NULL)
202 
        {
203 
          en->get_value_a(request_id, &msg_ps->ext_object_def, vb->value_len, vb->value);
204 
          snmp_varbind_tail_add(&msg_ps->outvb, vb);
205 
          /* search again (if vb_idx < msg_ps->invb.count) */
206 
          msg_ps->state = SNMP_MSG_SEARCH_OBJ;
207 
          msg_ps->vb_idx += 1;
208 
        }
209 
        else
210 
        {
211 
          en->get_value_pc(request_id, &msg_ps->ext_object_def);
212 
          LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: no variable space\n"));
213 
          msg_ps->vb_ptr->ident = vb->ident;
214 
          msg_ps->vb_ptr->ident_len = vb->ident_len;
215 
          mem_free(vb);
216 
          snmp_error_response(msg_ps,SNMP_ES_TOOBIG);
217 
        }
218 
      }
219 
      else
220 
      {
221 
        /* vb->value_len == 0, empty value (e.g. empty string) */
222 
        en->get_value_a(request_id, &msg_ps->ext_object_def, 0, NULL);
223 
        vb->value = NULL;
224 
        snmp_varbind_tail_add(&msg_ps->outvb, vb);
225 
        /* search again (if vb_idx < msg_ps->invb.count) */
226 
        msg_ps->state = SNMP_MSG_SEARCH_OBJ;
227 
        msg_ps->vb_idx += 1;
228 
      }
229 
    }
230 
    else
231 
    {
232 
      en->get_value_pc(request_id, &msg_ps->ext_object_def);
233 
      LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: no outvb space\n"));
234 
      snmp_error_response(msg_ps,SNMP_ES_TOOBIG);
235 
    }
236 
  }
237 
 
238 
  while ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) &&
239 
         (msg_ps->vb_idx < msg_ps->invb.count))
240 
  {
241 
    struct mib_node *mn;
242 
    struct snmp_name_ptr np;
243 
 
244 
    if (msg_ps->vb_idx == 0)
245 
    {
246 
      msg_ps->vb_ptr = msg_ps->invb.head;
247 
    }
248 
    else
249 
    {
250 
      msg_ps->vb_ptr = msg_ps->vb_ptr->next;
251 
    }
252 
    /** test object identifier for .iso.org.dod.internet prefix */
253 
    if (snmp_iso_prefix_tst(msg_ps->vb_ptr->ident_len,  msg_ps->vb_ptr->ident))
254 
    {
255 
      mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->vb_ptr->ident_len - 4,
256 
                             msg_ps->vb_ptr->ident + 4, &np);
257 
    }
258 
    else
259 
    {
260 
      mn = NULL;
261 
    }
262 
    if (mn != NULL)
263 
    {
264 
      if (mn->node_type == MIB_NODE_EX)
265 
      {
266 
        /* external object */
267 
        struct mib_external_node *en = (struct mib_external_node*)mn;
268 
 
269 
        msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF;
270 
        /* save en && args in msg_ps!! */
271 
        msg_ps->ext_mib_node = en;
272 
        msg_ps->ext_name_ptr = np;
273 
 
274 
        en->get_object_def_q(en->addr_inf, request_id, np.ident_len, np.ident);
275 
      }
276 
      else
277 
      {
278 
        /* internal object */
279 
        struct obj_def object_def;
280 
 
281 
        msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF;
282 
        mn->get_object_def(np.ident_len, np.ident, &object_def);
283 
        if (object_def.instance != MIB_OBJECT_NONE)
284 
        {
285 
          mn = mn;
286 
        }
287 
        else
288 
        {
289 
          /* search failed, object id points to unknown object (nosuchname) */
290 
          mn =  NULL;
291 
        }
292 
        if (mn != NULL)
293 
        {
294 
          struct snmp_varbind *vb;
295 
 
296 
          msg_ps->state = SNMP_MSG_INTERNAL_GET_VALUE;
297 
          /* allocate output varbind */
298 
          vb = (struct snmp_varbind *)mem_malloc(sizeof(struct snmp_varbind));
299 
          LWIP_ASSERT("vb != NULL",vb != NULL);
300 
          if (vb != NULL)
301 
          {
302 
            vb->next = NULL;
303 
            vb->prev = NULL;
304 
 
305 
            /* move name from invb to outvb */
306 
            vb->ident = msg_ps->vb_ptr->ident;
307 
            vb->ident_len = msg_ps->vb_ptr->ident_len;
308 
            /* ensure this memory is refereced once only */
309 
            msg_ps->vb_ptr->ident = NULL;
310 
            msg_ps->vb_ptr->ident_len = 0;
311 
 
312 
            vb->value_type = object_def.asn_type;
313 
            vb->value_len = object_def.v_len;
314 
            if (vb->value_len > 0)
315 
            {
316 
              vb->value = mem_malloc(vb->value_len);
317 
              LWIP_ASSERT("vb->value != NULL",vb->value != NULL);
318 
              if (vb->value != NULL)
319 
              {
320 
                mn->get_value(&object_def, vb->value_len, vb->value);
321 
                snmp_varbind_tail_add(&msg_ps->outvb, vb);
322 
                msg_ps->state = SNMP_MSG_SEARCH_OBJ;
323 
                msg_ps->vb_idx += 1;
324 
              }
325 
              else
326 
              {
327 
                LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: couldn't allocate variable space\n"));
328 
                msg_ps->vb_ptr->ident = vb->ident;
329 
                msg_ps->vb_ptr->ident_len = vb->ident_len;
330 
                mem_free(vb);
331 
                snmp_error_response(msg_ps,SNMP_ES_TOOBIG);
332 
              }
333 
            }
334 
            else
335 
            {
336 
              /* vb->value_len == 0, empty value (e.g. empty string) */
337 
              vb->value = NULL;
338 
              snmp_varbind_tail_add(&msg_ps->outvb, vb);
339 
              msg_ps->state = SNMP_MSG_SEARCH_OBJ;
340 
              msg_ps->vb_idx += 1;
341 
            }
342 
          }
343 
          else
344 
          {
345 
            LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: couldn't allocate outvb space\n"));
346 
            snmp_error_response(msg_ps,SNMP_ES_TOOBIG);
347 
          }
348 
        }
349 
      }
350 
    }
351 
    if (mn == NULL)
352 
    {
353 
      /* mn == NULL, noSuchName */
354 
      snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME);
355 
    }
356 
  }
357 
  if ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) &&
358 
      (msg_ps->vb_idx == msg_ps->invb.count))
359 
  {
360 
    snmp_ok_response(msg_ps);
361 
  }
362 
}
363 
 
364 
/**
365 
 * Service an internal or external event for SNMP GETNEXT.
366 
 *
367 
 * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1)
368 
 * @param msg_ps points to the assosicated message process state
369 
 */
370 
static void
371 
snmp_msg_getnext_event(u8_t request_id, struct snmp_msg_pstat *msg_ps)
372 
{
373 
  LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_getnext_event: msg_ps->state==%"U16_F"\n",(u16_t)msg_ps->state));
374 
 
375 
  if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF)
376 
  {
377 
    struct mib_external_node *en;
378 
 
379 
    /* get_object_def() answer*/
380 
    en = msg_ps->ext_mib_node;
381 
 
382 
    /* translate answer into a known lifeform */
383 
    en->get_object_def_a(request_id, 1, &msg_ps->ext_oid.id[msg_ps->ext_oid.len - 1], &msg_ps->ext_object_def);
384 
    if (msg_ps->ext_object_def.instance != MIB_OBJECT_NONE)
385 
    {
386 
      msg_ps->state = SNMP_MSG_EXTERNAL_GET_VALUE;
387 
      en->get_value_q(request_id, &msg_ps->ext_object_def);
388 
    }
389 
    else
390 
    {
391 
      en->get_object_def_pc(request_id, 1, &msg_ps->ext_oid.id[msg_ps->ext_oid.len - 1]);
392 
      /* search failed, object id points to unknown object (nosuchname) */
393 
      snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME);
394 
    }
395 
  }
396 
  else if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_VALUE)
397 
  {
398 
    struct mib_external_node *en;
399 
    struct snmp_varbind *vb;
400 
 
401 
    /* get_value() answer */
402 
    en = msg_ps->ext_mib_node;
403 
 
404 
    vb = snmp_varbind_alloc(&msg_ps->ext_oid,
405 
                            msg_ps->ext_object_def.asn_type,
406 
                            msg_ps->ext_object_def.v_len);
407 
    if (vb != NULL)
408 
    {
409 
      en->get_value_a(request_id, &msg_ps->ext_object_def, vb->value_len, vb->value);
410 
      snmp_varbind_tail_add(&msg_ps->outvb, vb);
411 
      msg_ps->state = SNMP_MSG_SEARCH_OBJ;
412 
      msg_ps->vb_idx += 1;
413 
    }
414 
    else
415 
    {
416 
      en->get_value_pc(request_id, &msg_ps->ext_object_def);
417 
      LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_getnext_event: couldn't allocate outvb space\n"));
418 
      snmp_error_response(msg_ps,SNMP_ES_TOOBIG);
419 
    }
420 
  }
421 
 
422 
  while ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) &&
423 
         (msg_ps->vb_idx < msg_ps->invb.count))
424 
  {
425 
    struct mib_node *mn;
426 
    struct snmp_obj_id oid;
427 
 
428 
    if (msg_ps->vb_idx == 0)
429 
    {
430 
      msg_ps->vb_ptr = msg_ps->invb.head;
431 
    }
432 
    else
433 
    {
434 
      msg_ps->vb_ptr = msg_ps->vb_ptr->next;
435 
    }
436 
    if (snmp_iso_prefix_expand(msg_ps->vb_ptr->ident_len, msg_ps->vb_ptr->ident, &oid))
437 
    {
438 
      if (msg_ps->vb_ptr->ident_len > 3)
439 
      {
440 
        /* can offset ident_len and ident */
441 
        mn = snmp_expand_tree((struct mib_node*)&internet,
442 
                              msg_ps->vb_ptr->ident_len - 4,
443 
                              msg_ps->vb_ptr->ident + 4, &oid);
444 
      }
445 
      else
446 
      {
447 
        /* can't offset ident_len -4, ident + 4 */
448 
        mn = snmp_expand_tree((struct mib_node*)&internet, 0, NULL, &oid);
449 
      }
450 
    }
451 
    else
452 
    {
453 
      mn = NULL;
454 
    }
455 
    if (mn != NULL)
456 
    {
457 
      if (mn->node_type == MIB_NODE_EX)
458 
      {
459 
        /* external object */
460 
        struct mib_external_node *en = (struct mib_external_node*)mn;
461 
 
462 
        msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF;
463 
        /* save en && args in msg_ps!! */
464 
        msg_ps->ext_mib_node = en;
465 
        msg_ps->ext_oid = oid;
466 
 
467 
        en->get_object_def_q(en->addr_inf, request_id, 1, &oid.id[oid.len - 1]);
468 
      }
469 
      else
470 
      {
471 
        /* internal object */
472 
        struct obj_def object_def;
473 
        struct snmp_varbind *vb;
474 
 
475 
        msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF;
476 
        mn->get_object_def(1, &oid.id[oid.len - 1], &object_def);
477 
 
478 
        vb = snmp_varbind_alloc(&oid, object_def.asn_type, object_def.v_len);
479 
        if (vb != NULL)
480 
        {
481 
          msg_ps->state = SNMP_MSG_INTERNAL_GET_VALUE;
482 
          mn->get_value(&object_def, object_def.v_len, vb->value);
483 
          snmp_varbind_tail_add(&msg_ps->outvb, vb);
484 
          msg_ps->state = SNMP_MSG_SEARCH_OBJ;
485 
          msg_ps->vb_idx += 1;
486 
        }
487 
        else
488 
        {
489 
          LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv couldn't allocate outvb space\n"));
490 
          snmp_error_response(msg_ps,SNMP_ES_TOOBIG);
491 
        }
492 
      }
493 
    }
494 
    if (mn == NULL)
495 
    {
496 
      /* mn == NULL, noSuchName */
497 
      snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME);
498 
    }
499 
  }
500 
  if ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) &&
501 
      (msg_ps->vb_idx == msg_ps->invb.count))
502 
  {
503 
    snmp_ok_response(msg_ps);
504 
  }
505 
}
506 
 
507 
/**
508 
 * Service an internal or external event for SNMP SET.
509 
 *
510 
 * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1)
511 
 * @param msg_ps points to the assosicated message process state
512 
 */
513 
static void
514 
snmp_msg_set_event(u8_t request_id, struct snmp_msg_pstat *msg_ps)
515 
{
516 
  LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_set_event: msg_ps->state==%"U16_F"\n",(u16_t)msg_ps->state));
517 
 
518 
  if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF)
519 
  {
520 
    struct mib_external_node *en;
521 
    struct snmp_name_ptr np;
522 
 
523 
    /* get_object_def() answer*/
524 
    en = msg_ps->ext_mib_node;
525 
    np = msg_ps->ext_name_ptr;
526 
 
527 
    /* translate answer into a known lifeform */
528 
    en->get_object_def_a(request_id, np.ident_len, np.ident, &msg_ps->ext_object_def);
529 
    if (msg_ps->ext_object_def.instance != MIB_OBJECT_NONE)
530 
    {
531 
      msg_ps->state = SNMP_MSG_EXTERNAL_SET_TEST;
532 
      en->set_test_q(request_id, &msg_ps->ext_object_def);
533 
    }
534 
    else
535 
    {
536 
      en->get_object_def_pc(request_id, np.ident_len, np.ident);
537 
      /* search failed, object id points to unknown object (nosuchname) */
538 
      snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME);
539 
    }
540 
  }
541 
  else if (msg_ps->state == SNMP_MSG_EXTERNAL_SET_TEST)
542 
  {
543 
    struct mib_external_node *en;
544 
    struct snmp_name_ptr np;
545 
 
546 
    /* set_test() answer*/
547 
    en = msg_ps->ext_mib_node;
548 
    np = msg_ps->ext_name_ptr;
549 
 
550 
    if (msg_ps->ext_object_def.access == MIB_OBJECT_READ_WRITE)
551 
    {
552 
       if ((msg_ps->ext_object_def.asn_type == msg_ps->vb_ptr->value_type) &&
553 
           (en->set_test_a(request_id,&msg_ps->ext_object_def,
554 
                           msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value) != 0))
555 
      {
556 
        msg_ps->state = SNMP_MSG_SEARCH_OBJ;
557 
        msg_ps->vb_idx += 1;
558 
      }
559 
      else
560 
      {
561 
        en->set_test_pc(request_id,&msg_ps->ext_object_def);
562 
        /* bad value */
563 
        snmp_error_response(msg_ps,SNMP_ES_BADVALUE);
564 
      }
565 
    }
566 
    else
567 
    {
568 
      en->set_test_pc(request_id,&msg_ps->ext_object_def);
569 
      /* object not available for set */
570 
      snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME);
571 
    }
572 
  }
573 
  else if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF_S)
574 
  {
575 
    struct mib_external_node *en;
576 
    struct snmp_name_ptr np;
577 
 
578 
    /* get_object_def() answer*/
579 
    en = msg_ps->ext_mib_node;
580 
    np = msg_ps->ext_name_ptr;
581 
 
582 
    /* translate answer into a known lifeform */
583 
    en->get_object_def_a(request_id, np.ident_len, np.ident, &msg_ps->ext_object_def);
584 
    if (msg_ps->ext_object_def.instance != MIB_OBJECT_NONE)
585 
    {
586 
      msg_ps->state = SNMP_MSG_EXTERNAL_SET_VALUE;
587 
      en->set_value_q(request_id, &msg_ps->ext_object_def,
588 
                      msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value);
589 
    }
590 
    else
591 
    {
592 
      en->get_object_def_pc(request_id, np.ident_len, np.ident);
593 
      /* set_value failed, object has disappeared for some odd reason?? */
594 
      snmp_error_response(msg_ps,SNMP_ES_GENERROR);
595 
    }
596 
  }
597 
  else if (msg_ps->state == SNMP_MSG_EXTERNAL_SET_VALUE)
598 
  {
599 
    struct mib_external_node *en;
600 
 
601 
    /** set_value_a() @todo: use reply value?? */
602 
    en = msg_ps->ext_mib_node;
603 
    en->set_value_a(request_id, &msg_ps->ext_object_def, 0, NULL);
604 
 
605 
    /** @todo use set_value_pc() if toobig */
606 
    msg_ps->state = SNMP_MSG_INTERNAL_SET_VALUE;
607 
    msg_ps->vb_idx += 1;
608 
  }
609 
 
610 
  /* test all values before setting */
611 
  while ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) &&
612 
         (msg_ps->vb_idx < msg_ps->invb.count))
613 
  {
614 
    struct mib_node *mn;
615 
    struct snmp_name_ptr np;
616 
 
617 
    if (msg_ps->vb_idx == 0)
618 
    {
619 
      msg_ps->vb_ptr = msg_ps->invb.head;
620 
    }
621 
    else
622 
    {
623 
      msg_ps->vb_ptr = msg_ps->vb_ptr->next;
624 
    }
625 
    /** test object identifier for .iso.org.dod.internet prefix */
626 
    if (snmp_iso_prefix_tst(msg_ps->vb_ptr->ident_len,  msg_ps->vb_ptr->ident))
627 
    {
628 
      mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->vb_ptr->ident_len - 4,
629 
                             msg_ps->vb_ptr->ident + 4, &np);
630 
    }
631 
    else
632 
    {
633 
      mn = NULL;
634 
    }
635 
    if (mn != NULL)
636 
    {
637 
      if (mn->node_type == MIB_NODE_EX)
638 
      {
639 
        /* external object */
640 
        struct mib_external_node *en = (struct mib_external_node*)mn;
641 
 
642 
        msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF;
643 
        /* save en && args in msg_ps!! */
644 
        msg_ps->ext_mib_node = en;
645 
        msg_ps->ext_name_ptr = np;
646 
 
647 
        en->get_object_def_q(en->addr_inf, request_id, np.ident_len, np.ident);
648 
      }
649 
      else
650 
      {
651 
        /* internal object */
652 
        struct obj_def object_def;
653 
 
654 
        msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF;
655 
        mn->get_object_def(np.ident_len, np.ident, &object_def);
656 
        if (object_def.instance != MIB_OBJECT_NONE)
657 
        {
658 
          mn = mn;
659 
        }
660 
        else
661 
        {
662 
          /* search failed, object id points to unknown object (nosuchname) */
663 
          mn = NULL;
664 
        }
665 
        if (mn != NULL)
666 
        {
667 
          msg_ps->state = SNMP_MSG_INTERNAL_SET_TEST;
668 
 
669 
          if (object_def.access == MIB_OBJECT_READ_WRITE)
670 
          {
671 
            if ((object_def.asn_type == msg_ps->vb_ptr->value_type) &&
672 
                (mn->set_test(&object_def,msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value) != 0))
673 
            {
674 
              msg_ps->state = SNMP_MSG_SEARCH_OBJ;
675 
              msg_ps->vb_idx += 1;
676 
            }
677 
            else
678 
            {
679 
              /* bad value */
680 
              snmp_error_response(msg_ps,SNMP_ES_BADVALUE);
681 
            }
682 
          }
683 
          else
684 
          {
685 
            /* object not available for set */
686 
            snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME);
687 
          }
688 
        }
689 
      }
690 
    }
691 
    if (mn == NULL)
692 
    {
693 
      /* mn == NULL, noSuchName */
694 
      snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME);
695 
    }
696 
  }
697 
 
698 
  if ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) &&
699 
      (msg_ps->vb_idx == msg_ps->invb.count))
700 
  {
701 
    msg_ps->vb_idx = 0;
702 
    msg_ps->state = SNMP_MSG_INTERNAL_SET_VALUE;
703 
  }
704 
 
705 
  /* set all values "atomically" (be as "atomic" as possible) */
706 
  while ((msg_ps->state == SNMP_MSG_INTERNAL_SET_VALUE) &&
707 
         (msg_ps->vb_idx < msg_ps->invb.count))
708 
  {
709 
    struct mib_node *mn;
710 
    struct snmp_name_ptr np;
711 
 
712 
    if (msg_ps->vb_idx == 0)
713 
    {
714 
      msg_ps->vb_ptr = msg_ps->invb.head;
715 
    }
716 
    else
717 
    {
718 
      msg_ps->vb_ptr = msg_ps->vb_ptr->next;
719 
    }
720 
    /* skip iso prefix test, was done previously while settesting() */
721 
    mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->vb_ptr->ident_len - 4,
722 
                           msg_ps->vb_ptr->ident + 4, &np);
723 
    /* check if object is still available
724 
       (e.g. external hot-plug thingy present?) */
725 
    if (mn != NULL)
726 
    {
727 
      if (mn->node_type == MIB_NODE_EX)
728 
      {
729 
        /* external object */
730 
        struct mib_external_node *en = (struct mib_external_node*)mn;
731 
 
732 
        msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF_S;
733 
        /* save en && args in msg_ps!! */
734 
        msg_ps->ext_mib_node = en;
735 
        msg_ps->ext_name_ptr = np;
736 
 
737 
        en->get_object_def_q(en->addr_inf, request_id, np.ident_len, np.ident);
738 
      }
739 
      else
740 
      {
741 
        /* internal object */
742 
        struct obj_def object_def;
743 
 
744 
        msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF_S;
745 
        mn->get_object_def(np.ident_len, np.ident, &object_def);
746 
        msg_ps->state = SNMP_MSG_INTERNAL_SET_VALUE;
747 
        mn->set_value(&object_def,msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value);
748 
        msg_ps->vb_idx += 1;
749 
      }
750 
    }
751 
  }
752 
  if ((msg_ps->state == SNMP_MSG_INTERNAL_SET_VALUE) &&
753 
      (msg_ps->vb_idx == msg_ps->invb.count))
754 
  {
755 
    /* simply echo the input if we can set it
756 
       @todo do we need to return the actual value?
757 
       e.g. if value is silently modified or behaves sticky? */
758 
    msg_ps->outvb = msg_ps->invb;
759 
    msg_ps->invb.head = NULL;
760 
    msg_ps->invb.tail = NULL;
761 
    msg_ps->invb.count = 0;
762 
    snmp_ok_response(msg_ps);
763 
  }
764 
}
765 
 
766 
 
767 
/**
768 
 * Handle one internal or external event.
769 
 * Called for one async event. (recv external/private answer)
770 
 *
771 
 * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1)
772 
 */
773 
void
774 
snmp_msg_event(u8_t request_id)
775 
{
776 
  struct snmp_msg_pstat *msg_ps;
777 
 
778 
  if (request_id < SNMP_CONCURRENT_REQUESTS)
779 
  {
780 
    msg_ps = &msg_input_list[request_id];
781 
    if (msg_ps->rt == SNMP_ASN1_PDU_GET_NEXT_REQ)
782 
    {
783 
      snmp_msg_getnext_event(request_id, msg_ps);
784 
    }
785 
    else if (msg_ps->rt == SNMP_ASN1_PDU_GET_REQ)
786 
    {
787 
      snmp_msg_get_event(request_id, msg_ps);
788 
    }
789 
    else if(msg_ps->rt == SNMP_ASN1_PDU_SET_REQ)
790 
    {
791 
      snmp_msg_set_event(request_id, msg_ps);
792 
    }
793 
  }
794 
}
795 
 
796 
 
797 
/* lwIP UDP receive callback function */
798 
static void
799 
snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port)
800 
{
801 
  struct udp_hdr *udphdr;
802 
 
803 
  /* suppress unused argument warning */
804 
  if (arg);
805 
  /* peek in the UDP header (goto IP payload) */
806 
  pbuf_header(p, UDP_HLEN);
807 
  udphdr = p->payload;
808 
 
809 
  /* check if datagram is really directed at us (including broadcast requests) */
810 
  if ((pcb == snmp1_pcb) && (ntohs(udphdr->dest) == 161))
811 
  {
812 
    struct snmp_msg_pstat *msg_ps;
813 
    u8_t req_idx;
814 
 
815 
    /* traverse input message process list, look for SNMP_MSG_EMPTY */
816 
    msg_ps = &msg_input_list[0];
817 
    req_idx = 0;
818 
    while ((req_idx<SNMP_CONCURRENT_REQUESTS) && (msg_ps->state != SNMP_MSG_EMPTY))
819 
    {
820 
      req_idx++;
821 
      msg_ps++;
822 
    }
823 
    if (req_idx != SNMP_CONCURRENT_REQUESTS)
824 
    {
825 
      err_t err_ret;
826 
      u16_t payload_len;
827 
      u16_t payload_ofs;
828 
      u16_t varbind_ofs = 0;
829 
 
830 
      /* accepting request */
831 
      snmp_inc_snmpinpkts();
832 
      /* record used 'protocol control block' */
833 
      msg_ps->pcb = pcb;
834 
      /* source address (network order) */
835 
      msg_ps->sip = *addr;
836 
      /* source port (host order (lwIP oddity)) */
837 
      msg_ps->sp = port;
838 
      /* read UDP payload length from UDP header */
839 
      payload_len = ntohs(udphdr->len) - UDP_HLEN;
840 
 
841 
      /* adjust to UDP payload */
842 
      payload_ofs = UDP_HLEN;
843 
 
844 
      /* check total length, version, community, pdu type */
845 
      err_ret = snmp_pdu_header_check(p, payload_ofs, payload_len, &varbind_ofs, msg_ps);
846 
      if (((msg_ps->rt == SNMP_ASN1_PDU_GET_REQ) ||
847 
           (msg_ps->rt == SNMP_ASN1_PDU_GET_NEXT_REQ) ||
848 
           (msg_ps->rt == SNMP_ASN1_PDU_SET_REQ)) &&
849 
          ((msg_ps->error_status == SNMP_ES_NOERROR) &&
850 
           (msg_ps->error_index == 0)) )
851 
      {
852 
        /* Only accept requests and requests without error (be robust) */
853 
        err_ret = err_ret;
854 
      }
855 
      else
856 
      {
857 
        /* Reject response and trap headers or error requests as input! */
858 
        err_ret = ERR_ARG;
859 
      }
860 
      if (err_ret == ERR_OK)
861 
      {
862 
        LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv ok, community %s\n", msg_ps->community));
863 
 
864 
        /* Builds a list of variable bindings. Copy the varbinds from the pbuf
865 
          chain to glue them when these are divided over two or more pbuf's. */
866 
        err_ret = snmp_pdu_dec_varbindlist(p, varbind_ofs, &varbind_ofs, msg_ps);
867 
        if ((err_ret == ERR_OK) && (msg_ps->invb.count > 0))
868 
        {
869 
          /* we've decoded the incoming message, release input msg now */
870 
          pbuf_free(p);
871 
 
872 
          msg_ps->error_status = SNMP_ES_NOERROR;
873 
          msg_ps->error_index = 0;
874 
          /* find object for each variable binding */
875 
          msg_ps->state = SNMP_MSG_SEARCH_OBJ;
876 
          /* first variable binding from list to inspect */
877 
          msg_ps->vb_idx = 0;
878 
 
879 
          LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv varbind cnt=%"U16_F"\n",(u16_t)msg_ps->invb.count));
880 
 
881 
          /* handle input event and as much objects as possible in one go */
882 
          snmp_msg_event(req_idx);
883 
        }
884 
        else
885 
        {
886 
          /* varbind-list decode failed, or varbind list empty.
887 
             drop request silently, do not return error!
888 
             (errors are only returned for a specific varbind failure) */
889 
          pbuf_free(p);
890 
          LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_pdu_dec_varbindlist() failed\n"));
891 
        }
892 
      }
893 
      else
894 
      {
895 
        /* header check failed
896 
           drop request silently, do not return error! */
897 
        pbuf_free(p);
898 
        LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_pdu_header_check() failed\n"));
899 
      }
900 
    }
901 
    else
902 
    {
903 
      /* exceeding number of concurrent requests */
904 
      pbuf_free(p);
905 
    }
906 
  }
907 
  else
908 
  {
909 
    /* datagram not for us */
910 
    pbuf_free(p);
911 
  }
912 
}
913 
 
914 
/**
915 
 * Checks and decodes incoming SNMP message header, logs header errors.
916 
 *
917 
 * @param p points to pbuf chain of SNMP message (UDP payload)
918 
 * @param ofs points to first octet of SNMP message
919 
 * @param pdu_len the length of the UDP payload
920 
 * @param ofs_ret returns the ofset of the variable bindings
921 
 * @param m_stat points to the current message request state return
922 
 * @return
923 
 * - ERR_OK SNMP header is sane and accepted
924 
 * - ERR_ARG SNMP header is either malformed or rejected
925 
 */
926 
static err_t
927 
snmp_pdu_header_check(struct pbuf *p, u16_t ofs, u16_t pdu_len, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat)
928 
{
929 
  err_t derr;
930 
  u16_t len, ofs_base;
931 
  u8_t  len_octets;
932 
  u8_t  type;
933 
  s32_t version;
934 
 
935 
  ofs_base = ofs;
936 
  snmp_asn1_dec_type(p, ofs, &type);
937 
  derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
938 
  if ((derr != ERR_OK) ||
939 
      (pdu_len != (1 + len_octets + len)) ||
940 
      (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ)))
941 
  {
942 
    snmp_inc_snmpinasnparseerrs();
943 
    return ERR_ARG;
944 
  }
945 
  ofs += (1 + len_octets);
946 
  snmp_asn1_dec_type(p, ofs, &type);
947 
  derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
948 
  if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)))
949 
  {
950 
    /* can't decode or no integer (version) */
951 
    snmp_inc_snmpinasnparseerrs();
952 
    return ERR_ARG;
953 
  }
954 
  derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &version);
955 
  if (derr != ERR_OK)
956 
  {
957 
    /* can't decode */
958 
    snmp_inc_snmpinasnparseerrs();
959 
    return ERR_ARG;
960 
  }
961 
  if (version != 0)
962 
  {
963 
    /* not version 1 */
964 
    snmp_inc_snmpinbadversions();
965 
    return ERR_ARG;
966 
  }
967 
  ofs += (1 + len_octets + len);
968 
  snmp_asn1_dec_type(p, ofs, &type);
969 
  derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
970 
  if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR)))
971 
  {
972 
    /* can't decode or no octet string (community) */
973 
    snmp_inc_snmpinasnparseerrs();
974 
    return ERR_ARG;
975 
  }
976 
  derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, SNMP_COMMUNITY_STR_LEN, m_stat->community);
977 
  if (derr != ERR_OK)
978 
  {
979 
    snmp_inc_snmpinasnparseerrs();
980 
    return ERR_ARG;
981 
  }
982 
  /* add zero terminator */
983 
  len = ((len < (SNMP_COMMUNITY_STR_LEN))?(len):(SNMP_COMMUNITY_STR_LEN));
984 
  m_stat->community[len] = 0;
985 
  m_stat->com_strlen = len;
986 
  if (strncmp(snmp_publiccommunity, (const char*)m_stat->community, SNMP_COMMUNITY_STR_LEN) != 0)
987 
  {
988 
    /** @todo: move this if we need to check more names */
989 
    snmp_inc_snmpinbadcommunitynames();
990 
    snmp_authfail_trap();
991 
    return ERR_ARG;
992 
  }
993 
  ofs += (1 + len_octets + len);
994 
  snmp_asn1_dec_type(p, ofs, &type);
995 
  derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
996 
  if (derr != ERR_OK)
997 
  {
998 
    snmp_inc_snmpinasnparseerrs();
999 
    return ERR_ARG;
1000 
  }
1001 
  switch(type)
1002 
  {
1003 
    case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_REQ):
1004 
      /* GetRequest PDU */
1005 
      snmp_inc_snmpingetrequests();
1006 
      derr = ERR_OK;
1007 
      break;
1008 
    case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_NEXT_REQ):
1009 
      /* GetNextRequest PDU */
1010 
      snmp_inc_snmpingetnexts();
1011 
      derr = ERR_OK;
1012 
      break;
1013 
    case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_RESP):
1014 
      /* GetResponse PDU */
1015 
      snmp_inc_snmpingetresponses();
1016 
      derr = ERR_ARG;
1017 
      break;
1018 
    case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_SET_REQ):
1019 
      /* SetRequest PDU */
1020 
      snmp_inc_snmpinsetrequests();
1021 
      derr = ERR_OK;
1022 
      break;
1023 
    case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_TRAP):
1024 
      /* Trap PDU */
1025 
      snmp_inc_snmpintraps();
1026 
      derr = ERR_ARG;
1027 
      break;
1028 
    default:
1029 
      snmp_inc_snmpinasnparseerrs();
1030 
      derr = ERR_ARG;
1031 
      break;
1032 
  }
1033 
  if (derr != ERR_OK)
1034 
  {
1035 
    /* unsupported input PDU for this agent (no parse error) */
1036 
    return ERR_ARG;
1037 
  }
1038 
  m_stat->rt = type & 0x1F;
1039 
  ofs += (1 + len_octets);
1040 
  if (len != (pdu_len - (ofs - ofs_base)))
1041 
  {
1042 
    /* decoded PDU length does not equal actual payload length */
1043 
    snmp_inc_snmpinasnparseerrs();
1044 
    return ERR_ARG;
1045 
  }
1046 
  snmp_asn1_dec_type(p, ofs, &type);
1047 
  derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
1048 
  if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)))
1049 
  {
1050 
    /* can't decode or no integer (request ID) */
1051 
    snmp_inc_snmpinasnparseerrs();
1052 
    return ERR_ARG;
1053 
  }
1054 
  derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &m_stat->rid);
1055 
  if (derr != ERR_OK)
1056 
  {
1057 
    /* can't decode */
1058 
    snmp_inc_snmpinasnparseerrs();
1059 
    return ERR_ARG;
1060 
  }
1061 
  ofs += (1 + len_octets + len);
1062 
  snmp_asn1_dec_type(p, ofs, &type);
1063 
  derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
1064 
  if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)))
1065 
  {
1066 
    /* can't decode or no integer (error-status) */
1067 
    snmp_inc_snmpinasnparseerrs();
1068 
    return ERR_ARG;
1069 
  }
1070 
  /* must be noError (0) for incoming requests.
1071 
     log errors for mib-2 completeness and for debug purposes */
1072 
  derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &m_stat->error_status);
1073 
  if (derr != ERR_OK)
1074 
  {
1075 
    /* can't decode */
1076 
    snmp_inc_snmpinasnparseerrs();
1077 
    return ERR_ARG;
1078 
  }
1079 
  switch (m_stat->error_status)
1080 
  {
1081 
    case SNMP_ES_TOOBIG:
1082 
      snmp_inc_snmpintoobigs();
1083 
      break;
1084 
    case SNMP_ES_NOSUCHNAME:
1085 
      snmp_inc_snmpinnosuchnames();
1086 
      break;
1087 
    case SNMP_ES_BADVALUE:
1088 
      snmp_inc_snmpinbadvalues();
1089 
      break;
1090 
    case SNMP_ES_READONLY:
1091 
      snmp_inc_snmpinreadonlys();
1092 
      break;
1093 
    case SNMP_ES_GENERROR:
1094 
      snmp_inc_snmpingenerrs();
1095 
      break;
1096 
  }
1097 
  ofs += (1 + len_octets + len);
1098 
  snmp_asn1_dec_type(p, ofs, &type);
1099 
  derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
1100 
  if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)))
1101 
  {
1102 
    /* can't decode or no integer (error-index) */
1103 
    snmp_inc_snmpinasnparseerrs();
1104 
    return ERR_ARG;
1105 
  }
1106 
  /* must be 0 for incoming requests.
1107 
     decode anyway to catch bad integers (and dirty tricks) */
1108 
  derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &m_stat->error_index);
1109 
  if (derr != ERR_OK)
1110 
  {
1111 
    /* can't decode */
1112 
    snmp_inc_snmpinasnparseerrs();
1113 
    return ERR_ARG;
1114 
  }
1115 
  ofs += (1 + len_octets + len);
1116 
  *ofs_ret = ofs;
1117 
  return ERR_OK;
1118 
}
1119 
 
1120 
static err_t
1121 
snmp_pdu_dec_varbindlist(struct pbuf *p, u16_t ofs, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat)
1122 
{
1123 
  err_t derr;
1124 
  u16_t len, vb_len;
1125 
  u8_t  len_octets;
1126 
  u8_t type;
1127 
 
1128 
  /* variable binding list */
1129 
  snmp_asn1_dec_type(p, ofs, &type);
1130 
  derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &vb_len);
1131 
  if ((derr != ERR_OK) ||
1132 
      (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ)))
1133 
  {
1134 
    snmp_inc_snmpinasnparseerrs();
1135 
    return ERR_ARG;
1136 
  }
1137 
  ofs += (1 + len_octets);
1138 
 
1139 
  /* start with empty list */
1140 
  m_stat->invb.count = 0;
1141 
  m_stat->invb.head = NULL;
1142 
  m_stat->invb.tail = NULL;
1143 
 
1144 
  while (vb_len > 0)
1145 
  {
1146 
    struct snmp_obj_id oid, oid_value;
1147 
    struct snmp_varbind *vb;
1148 
 
1149 
    snmp_asn1_dec_type(p, ofs, &type);
1150 
    derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
1151 
    if ((derr != ERR_OK) ||
1152 
        (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ)) ||
1153 
        (len <= 0) || (len > vb_len))
1154 
    {
1155 
      snmp_inc_snmpinasnparseerrs();
1156 
      /* free varbinds (if available) */
1157 
      snmp_varbind_list_free(&m_stat->invb);
1158 
      return ERR_ARG;
1159 
    }
1160 
    ofs += (1 + len_octets);
1161 
    vb_len -= (1 + len_octets);
1162 
 
1163 
    snmp_asn1_dec_type(p, ofs, &type);
1164 
    derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
1165 
    if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID)))
1166 
    {
1167 
      /* can't decode object name length */
1168 
      snmp_inc_snmpinasnparseerrs();
1169 
      /* free varbinds (if available) */
1170 
      snmp_varbind_list_free(&m_stat->invb);
1171 
      return ERR_ARG;
1172 
    }
1173 
    derr = snmp_asn1_dec_oid(p, ofs + 1 + len_octets, len, &oid);
1174 
    if (derr != ERR_OK)
1175 
    {
1176 
      /* can't decode object name */
1177 
      snmp_inc_snmpinasnparseerrs();
1178 
      /* free varbinds (if available) */
1179 
      snmp_varbind_list_free(&m_stat->invb);
1180 
      return ERR_ARG;
1181 
    }
1182 
    ofs += (1 + len_octets + len);
1183 
    vb_len -= (1 + len_octets + len);
1184 
 
1185 
    snmp_asn1_dec_type(p, ofs, &type);
1186 
    derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
1187 
    if (derr != ERR_OK)
1188 
    {
1189 
      /* can't decode object value length */
1190 
      snmp_inc_snmpinasnparseerrs();
1191 
      /* free varbinds (if available) */
1192 
      snmp_varbind_list_free(&m_stat->invb);
1193 
      return ERR_ARG;
1194 
    }
1195 
 
1196 
    switch (type)
1197 
    {
1198 
      case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG):
1199 
        vb = snmp_varbind_alloc(&oid, type, sizeof(s32_t));
1200 
        if (vb != NULL)
1201 
        {
1202 
          s32_t *vptr = vb->value;
1203 
 
1204 
          derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, vptr);
1205 
          snmp_varbind_tail_add(&m_stat->invb, vb);
1206 
        }
1207 
        else
1208 
        {
1209 
          derr = ERR_ARG;
1210 
        }
1211 
        break;
1212 
      case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_COUNTER):
1213 
      case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_GAUGE):
1214 
      case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS):
1215 
        vb = snmp_varbind_alloc(&oid, type, sizeof(u32_t));
1216 
        if (vb != NULL)
1217 
        {
1218 
          u32_t *vptr = vb->value;
1219 
 
1220 
          derr = snmp_asn1_dec_u32t(p, ofs + 1 + len_octets, len, vptr);
1221 
          snmp_varbind_tail_add(&m_stat->invb, vb);
1222 
        }
1223 
        else
1224 
        {
1225 
          derr = ERR_ARG;
1226 
        }
1227 
        break;
1228 
      case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR):
1229 
      case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE):
1230 
        vb = snmp_varbind_alloc(&oid, type, len);
1231 
        if (vb != NULL)
1232 
        {
1233 
          derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, vb->value_len, vb->value);
1234 
          snmp_varbind_tail_add(&m_stat->invb, vb);
1235 
        }
1236 
        else
1237 
        {
1238 
          derr = ERR_ARG;
1239 
        }
1240 
        break;
1241 
      case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL):
1242 
        vb = snmp_varbind_alloc(&oid, type, 0);
1243 
        if (vb != NULL)
1244 
        {
1245 
          snmp_varbind_tail_add(&m_stat->invb, vb);
1246 
          derr = ERR_OK;
1247 
        }
1248 
        else
1249 
        {
1250 
          derr = ERR_ARG;
1251 
        }
1252 
        break;
1253 
      case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID):
1254 
        derr = snmp_asn1_dec_oid(p, ofs + 1 + len_octets, len, &oid_value);
1255 
        if (derr == ERR_OK)
1256 
        {
1257 
          vb = snmp_varbind_alloc(&oid, type, oid_value.len * sizeof(s32_t));
1258 
          if (vb != NULL)
1259 
          {
1260 
            u8_t i = oid_value.len;
1261 
            s32_t *vptr = vb->value;
1262 
 
1263 
            while(i > 0)
1264 
            {
1265 
              i--;
1266 
              vptr[i] = oid_value.id[i];
1267 
            }
1268 
            snmp_varbind_tail_add(&m_stat->invb, vb);
1269 
            derr = ERR_OK;
1270 
          }
1271 
          else
1272 
          {
1273 
            derr = ERR_ARG;
1274 
          }
1275 
        }
1276 
        break;
1277 
      case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR):
1278 
        if (len == 4)
1279 
        {
1280 
          /* must be exactly 4 octets! */
1281 
          vb = snmp_varbind_alloc(&oid, type, 4);
1282 
          if (vb != NULL)
1283 
          {
1284 
            derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, vb->value_len, vb->value);
1285 
            snmp_varbind_tail_add(&m_stat->invb, vb);
1286 
          }
1287 
          else
1288 
          {
1289 
            derr = ERR_ARG;
1290 
          }
1291 
        }
1292 
        else
1293 
        {
1294 
          derr = ERR_ARG;
1295 
        }
1296 
        break;
1297 
      default:
1298 
        derr = ERR_ARG;
1299 
        break;
1300 
    }
1301 
    if (derr != ERR_OK)
1302 
    {
1303 
      snmp_inc_snmpinasnparseerrs();
1304 
      /* free varbinds (if available) */
1305 
      snmp_varbind_list_free(&m_stat->invb);
1306 
      return ERR_ARG;
1307 
    }
1308 
    ofs += (1 + len_octets + len);
1309 
    vb_len -= (1 + len_octets + len);
1310 
  }
1311 
 
1312 
  if (m_stat->rt == SNMP_ASN1_PDU_SET_REQ)
1313 
  {
1314 
    snmp_add_snmpintotalsetvars(m_stat->invb.count);
1315 
  }
1316 
  else
1317 
  {
1318 
    snmp_add_snmpintotalreqvars(m_stat->invb.count);
1319 
  }
1320 
 
1321 
  *ofs_ret = ofs;
1322 
  return ERR_OK;
1323 
}
1324 
 
1325 
struct snmp_varbind*
1326 
snmp_varbind_alloc(struct snmp_obj_id *oid, u8_t type, u8_t len)
1327 
{
1328 
  struct snmp_varbind *vb;
1329 
 
1330 
  vb = (struct snmp_varbind *)mem_malloc(sizeof(struct snmp_varbind));
1331 
  LWIP_ASSERT("vb != NULL",vb != NULL);
1332 
  if (vb != NULL)
1333 
  {
1334 
    u8_t i;
1335 
 
1336 
    vb->next = NULL;
1337 
    vb->prev = NULL;
1338 
    i = oid->len;
1339 
    vb->ident_len = i;
1340 
    if (i > 0)
1341 
    {
1342 
      /* allocate array of s32_t for our object identifier */
1343 
      vb->ident = (s32_t*)mem_malloc(sizeof(s32_t) * i);
1344 
      LWIP_ASSERT("vb->ident != NULL",vb->ident != NULL);
1345 
      if (vb->ident == NULL)
1346 
      {
1347 
        mem_free(vb);
1348 
        return NULL;
1349 
      }
1350 
      while(i > 0)
1351 
      {
1352 
        i--;
1353 
        vb->ident[i] = oid->id[i];
1354 
      }
1355 
    }
1356 
    else
1357 
    {
1358 
      /* i == 0, pass zero length object identifier */
1359 
      vb->ident = NULL;
1360 
    }
1361 
    vb->value_type = type;
1362 
    vb->value_len = len;
1363 
    if (len > 0)
1364 
    {
1365 
      /* allocate raw bytes for our object value */
1366 
      vb->value = mem_malloc(len);
1367 
      LWIP_ASSERT("vb->value != NULL",vb->value != NULL);
1368 
      if (vb->value == NULL)
1369 
      {
1370 
        if (vb->ident != NULL)
1371 
        {
1372 
          mem_free(vb->ident);
1373 
        }
1374 
        mem_free(vb);
1375 
        return NULL;
1376 
      }
1377 
    }
1378 
    else
1379 
    {
1380 
      /* ASN1_NUL type, or zero length ASN1_OC_STR */
1381 
      vb->value = NULL;
1382 
    }
1383 
  }
1384 
  return vb;
1385 
}
1386 
 
1387 
void
1388 
snmp_varbind_free(struct snmp_varbind *vb)
1389 
{
1390 
  if (vb->value != NULL )
1391 
  {
1392 
    mem_free(vb->value);
1393 
  }
1394 
  if (vb->ident != NULL )
1395 
  {
1396 
    mem_free(vb->ident);
1397 
  }
1398 
  mem_free(vb);
1399 
}
1400 
 
1401 
void
1402 
snmp_varbind_list_free(struct snmp_varbind_root *root)
1403 
{
1404 
  struct snmp_varbind *vb, *prev;
1405 
 
1406 
  vb = root->tail;
1407 
  while ( vb != NULL )
1408 
  {
1409 
    prev = vb->prev;
1410 
    snmp_varbind_free(vb);
1411 
    vb = prev;
1412 
  }
1413 
  root->count = 0;
1414 
  root->head = NULL;
1415 
  root->tail = NULL;
1416 
}
1417 
 
1418 
void
1419 
snmp_varbind_tail_add(struct snmp_varbind_root *root, struct snmp_varbind *vb)
1420 
{
1421 
  if (root->count == 0)
1422 
  {
1423 
    /* add first varbind to list */
1424 
    root->head = vb;
1425 
    root->tail = vb;
1426 
  }
1427 
  else
1428 
  {
1429 
    /* add nth varbind to list tail */
1430 
    root->tail->next = vb;
1431 
    vb->prev = root->tail;
1432 
    root->tail = vb;
1433 
  }
1434 
  root->count += 1;
1435 
}
1436 
 
1437 
struct snmp_varbind*
1438 
snmp_varbind_tail_remove(struct snmp_varbind_root *root)
1439 
{
1440 
  struct snmp_varbind* vb;
1441 
 
1442 
  if (root->count > 0)
1443 
  {
1444 
    /* remove tail varbind */
1445 
    vb = root->tail;
1446 
    root->tail = vb->prev;
1447 
    vb->prev->next = NULL;
1448 
    root->count -= 1;
1449 
  }
1450 
  else
1451 
  {
1452 
    /* nothing to remove */
1453 
    vb = NULL;
1454 
  }
1455 
  return vb;
1456 
}
1457 
 
1458 
#endif /* LWIP_SNMP */

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