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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [Common/] [ethernet/] [lwIP_132/] [src/] [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 /* don't build if not configured for use in lwipopts.h */
38 
 
39 
#include "lwip/ip_addr.h"
40 
#include "lwip/mem.h"
41 
#include "lwip/udp.h"
42 
#include "lwip/stats.h"
43 
#include "lwip/snmp.h"
44 
#include "lwip/snmp_asn1.h"
45 
#include "lwip/snmp_msg.h"
46 
#include "lwip/snmp_structs.h"
47 
 
48 
#include <string.h>
49 
 
50 
/* public (non-static) constants */
51 
/** SNMP v1 == 0 */
52 
const s32_t snmp_version = 0;
53 
/** default SNMP community string */
54 
const char snmp_publiccommunity[7] = "public";
55 
 
56 
/* statically allocated buffers for SNMP_CONCURRENT_REQUESTS */
57 
struct snmp_msg_pstat msg_input_list[SNMP_CONCURRENT_REQUESTS];
58 
/* UDP Protocol Control Block */
59 
struct udp_pcb *snmp1_pcb;
60 
 
61 
static void snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port);
62 
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);
63 
static err_t snmp_pdu_dec_varbindlist(struct pbuf *p, u16_t ofs, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat);
64 
 
65 
 
66 
/**
67 
 * Starts SNMP Agent.
68 
 * Allocates UDP pcb and binds it to IP_ADDR_ANY port 161.
69 
 */
70 
void
71 
snmp_init(void)
72 
{
73 
  struct snmp_msg_pstat *msg_ps;
74 
  u8_t i;
75 
 
76 
  snmp1_pcb = udp_new();
77 
  if (snmp1_pcb != NULL)
78 
  {
79 
    udp_recv(snmp1_pcb, snmp_recv, (void *)SNMP_IN_PORT);
80 
    udp_bind(snmp1_pcb, IP_ADDR_ANY, SNMP_IN_PORT);
81 
  }
82 
  msg_ps = &msg_input_list[0];
83 
  for (i=0; i<SNMP_CONCURRENT_REQUESTS; i++)
84 
  {
85 
    msg_ps->state = SNMP_MSG_EMPTY;
86 
    msg_ps->error_index = 0;
87 
    msg_ps->error_status = SNMP_ES_NOERROR;
88 
    msg_ps++;
89 
  }
90 
  trap_msg.pcb = snmp1_pcb;
91 
  /* The coldstart trap will only be output
92 
     if our outgoing interface is up & configured  */
93 
  snmp_coldstart_trap();
94 
}
95 
 
96 
static void
97 
snmp_error_response(struct snmp_msg_pstat *msg_ps, u8_t error)
98 
{
99 
  snmp_varbind_list_free(&msg_ps->outvb);
100 
  msg_ps->outvb = msg_ps->invb;
101 
  msg_ps->invb.head = NULL;
102 
  msg_ps->invb.tail = NULL;
103 
  msg_ps->invb.count = 0;
104 
  msg_ps->error_status = error;
105 
  msg_ps->error_index = 1 + msg_ps->vb_idx;
106 
  snmp_send_response(msg_ps);
107 
  snmp_varbind_list_free(&msg_ps->outvb);
108 
  msg_ps->state = SNMP_MSG_EMPTY;
109 
}
110 
 
111 
static void
112 
snmp_ok_response(struct snmp_msg_pstat *msg_ps)
113 
{
114 
  err_t err_ret;
115 
 
116 
  err_ret = snmp_send_response(msg_ps);
117 
  if (err_ret == ERR_MEM)
118 
  {
119 
    /* serious memory problem, can't return tooBig */
120 
  }
121 
  else
122 
  {
123 
    LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event = %"S32_F"\n",msg_ps->error_status));
124 
  }
125 
  /* free varbinds (if available) */
126 
  snmp_varbind_list_free(&msg_ps->invb);
127 
  snmp_varbind_list_free(&msg_ps->outvb);
128 
  msg_ps->state = SNMP_MSG_EMPTY;
129 
}
130 
 
131 
/**
132 
 * Service an internal or external event for SNMP GET.
133 
 *
134 
 * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1)
135 
 * @param msg_ps points to the assosicated message process state
136 
 */
137 
static void
138 
snmp_msg_get_event(u8_t request_id, struct snmp_msg_pstat *msg_ps)
139 
{
140 
  LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_get_event: msg_ps->state==%"U16_F"\n",(u16_t)msg_ps->state));
141 
 
142 
  if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF)
143 
  {
144 
    struct mib_external_node *en;
145 
    struct snmp_name_ptr np;
146 
 
147 
    /* get_object_def() answer*/
148 
    en = msg_ps->ext_mib_node;
149 
    np = msg_ps->ext_name_ptr;
150 
 
151 
    /* translate answer into a known lifeform */
152 
    en->get_object_def_a(request_id, np.ident_len, np.ident, &msg_ps->ext_object_def);
153 
    if (msg_ps->ext_object_def.instance != MIB_OBJECT_NONE)
154 
    {
155 
      msg_ps->state = SNMP_MSG_EXTERNAL_GET_VALUE;
156 
      en->get_value_q(request_id, &msg_ps->ext_object_def);
157 
    }
158 
    else
159 
    {
160 
      en->get_object_def_pc(request_id, np.ident_len, np.ident);
161 
      /* search failed, object id points to unknown object (nosuchname) */
162 
      snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME);
163 
    }
164 
  }
165 
  else if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_VALUE)
166 
  {
167 
    struct mib_external_node *en;
168 
    struct snmp_varbind *vb;
169 
 
170 
    /* get_value() answer */
171 
    en = msg_ps->ext_mib_node;
172 
 
173 
    /* allocate output varbind */
174 
    vb = (struct snmp_varbind *)mem_malloc(sizeof(struct snmp_varbind));
175 
    LWIP_ASSERT("vb != NULL",vb != NULL);
176 
    if (vb != NULL)
177 
    {
178 
      vb->next = NULL;
179 
      vb->prev = NULL;
180 
 
181 
      /* move name from invb to outvb */
182 
      vb->ident = msg_ps->vb_ptr->ident;
183 
      vb->ident_len = msg_ps->vb_ptr->ident_len;
184 
      /* ensure this memory is refereced once only */
185 
      msg_ps->vb_ptr->ident = NULL;
186 
      msg_ps->vb_ptr->ident_len = 0;
187 
 
188 
      vb->value_type = msg_ps->ext_object_def.asn_type;
189 
      vb->value_len =  msg_ps->ext_object_def.v_len;
190 
      if (vb->value_len > 0)
191 
      {
192 
        vb->value = mem_malloc(vb->value_len);
193 
        LWIP_ASSERT("vb->value != NULL",vb->value != NULL);
194 
        if (vb->value != NULL)
195 
        {
196 
          en->get_value_a(request_id, &msg_ps->ext_object_def, vb->value_len, vb->value);
197 
          snmp_varbind_tail_add(&msg_ps->outvb, vb);
198 
          /* search again (if vb_idx < msg_ps->invb.count) */
199 
          msg_ps->state = SNMP_MSG_SEARCH_OBJ;
200 
          msg_ps->vb_idx += 1;
201 
        }
202 
        else
203 
        {
204 
          en->get_value_pc(request_id, &msg_ps->ext_object_def);
205 
          LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: no variable space\n"));
206 
          msg_ps->vb_ptr->ident = vb->ident;
207 
          msg_ps->vb_ptr->ident_len = vb->ident_len;
208 
          mem_free(vb);
209 
          snmp_error_response(msg_ps,SNMP_ES_TOOBIG);
210 
        }
211 
      }
212 
      else
213 
      {
214 
        /* vb->value_len == 0, empty value (e.g. empty string) */
215 
        en->get_value_a(request_id, &msg_ps->ext_object_def, 0, NULL);
216 
        vb->value = NULL;
217 
        snmp_varbind_tail_add(&msg_ps->outvb, vb);
218 
        /* search again (if vb_idx < msg_ps->invb.count) */
219 
        msg_ps->state = SNMP_MSG_SEARCH_OBJ;
220 
        msg_ps->vb_idx += 1;
221 
      }
222 
    }
223 
    else
224 
    {
225 
      en->get_value_pc(request_id, &msg_ps->ext_object_def);
226 
      LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: no outvb space\n"));
227 
      snmp_error_response(msg_ps,SNMP_ES_TOOBIG);
228 
    }
229 
  }
230 
 
231 
  while ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) &&
232 
         (msg_ps->vb_idx < msg_ps->invb.count))
233 
  {
234 
    struct mib_node *mn;
235 
    struct snmp_name_ptr np;
236 
 
237 
    if (msg_ps->vb_idx == 0)
238 
    {
239 
      msg_ps->vb_ptr = msg_ps->invb.head;
240 
    }
241 
    else
242 
    {
243 
      msg_ps->vb_ptr = msg_ps->vb_ptr->next;
244 
    }
245 
    /** test object identifier for .iso.org.dod.internet prefix */
246 
    if (snmp_iso_prefix_tst(msg_ps->vb_ptr->ident_len,  msg_ps->vb_ptr->ident))
247 
    {
248 
      mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->vb_ptr->ident_len - 4,
249 
                             msg_ps->vb_ptr->ident + 4, &np);
250 
      if (mn != NULL)
251 
      {
252 
        if (mn->node_type == MIB_NODE_EX)
253 
        {
254 
          /* external object */
255 
          struct mib_external_node *en = (struct mib_external_node*)mn;
256 
 
257 
          msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF;
258 
          /* save en && args in msg_ps!! */
259 
          msg_ps->ext_mib_node = en;
260 
          msg_ps->ext_name_ptr = np;
261 
 
262 
          en->get_object_def_q(en->addr_inf, request_id, np.ident_len, np.ident);
263 
        }
264 
        else
265 
        {
266 
          /* internal object */
267 
          struct obj_def object_def;
268 
 
269 
          msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF;
270 
          mn->get_object_def(np.ident_len, np.ident, &object_def);
271 
          if (object_def.instance != MIB_OBJECT_NONE)
272 
          {
273 
            mn = mn;
274 
          }
275 
          else
276 
          {
277 
            /* search failed, object id points to unknown object (nosuchname) */
278 
            mn =  NULL;
279 
          }
280 
          if (mn != NULL)
281 
          {
282 
            struct snmp_varbind *vb;
283 
 
284 
            msg_ps->state = SNMP_MSG_INTERNAL_GET_VALUE;
285 
            /* allocate output varbind */
286 
            vb = (struct snmp_varbind *)mem_malloc(sizeof(struct snmp_varbind));
287 
            LWIP_ASSERT("vb != NULL",vb != NULL);
288 
            if (vb != NULL)
289 
            {
290 
              vb->next = NULL;
291 
              vb->prev = NULL;
292 
 
293 
              /* move name from invb to outvb */
294 
              vb->ident = msg_ps->vb_ptr->ident;
295 
              vb->ident_len = msg_ps->vb_ptr->ident_len;
296 
              /* ensure this memory is refereced once only */
297 
              msg_ps->vb_ptr->ident = NULL;
298 
              msg_ps->vb_ptr->ident_len = 0;
299 
 
300 
              vb->value_type = object_def.asn_type;
301 
              vb->value_len = object_def.v_len;
302 
              if (vb->value_len > 0)
303 
              {
304 
                vb->value = mem_malloc(vb->value_len);
305 
                LWIP_ASSERT("vb->value != NULL",vb->value != NULL);
306 
                if (vb->value != NULL)
307 
                {
308 
                  mn->get_value(&object_def, vb->value_len, vb->value);
309 
                  snmp_varbind_tail_add(&msg_ps->outvb, vb);
310 
                  msg_ps->state = SNMP_MSG_SEARCH_OBJ;
311 
                  msg_ps->vb_idx += 1;
312 
                }
313 
                else
314 
                {
315 
                  LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: couldn't allocate variable space\n"));
316 
                  msg_ps->vb_ptr->ident = vb->ident;
317 
                  msg_ps->vb_ptr->ident_len = vb->ident_len;
318 
                  mem_free(vb);
319 
                  snmp_error_response(msg_ps,SNMP_ES_TOOBIG);
320 
                }
321 
              }
322 
              else
323 
              {
324 
                /* vb->value_len == 0, empty value (e.g. empty string) */
325 
                vb->value = NULL;
326 
                snmp_varbind_tail_add(&msg_ps->outvb, vb);
327 
                msg_ps->state = SNMP_MSG_SEARCH_OBJ;
328 
                msg_ps->vb_idx += 1;
329 
              }
330 
            }
331 
            else
332 
            {
333 
              LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: couldn't allocate outvb space\n"));
334 
              snmp_error_response(msg_ps,SNMP_ES_TOOBIG);
335 
            }
336 
          }
337 
        }
338 
      }
339 
    }
340 
    else
341 
    {
342 
      mn = NULL;
343 
    }
344 
    if (mn == NULL)
345 
    {
346 
      /* mn == NULL, noSuchName */
347 
      snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME);
348 
    }
349 
  }
350 
  if ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) &&
351 
      (msg_ps->vb_idx == msg_ps->invb.count))
352 
  {
353 
    snmp_ok_response(msg_ps);
354 
  }
355 
}
356 
 
357 
/**
358 
 * Service an internal or external event for SNMP GETNEXT.
359 
 *
360 
 * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1)
361 
 * @param msg_ps points to the assosicated message process state
362 
 */
363 
static void
364 
snmp_msg_getnext_event(u8_t request_id, struct snmp_msg_pstat *msg_ps)
365 
{
366 
  LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_getnext_event: msg_ps->state==%"U16_F"\n",(u16_t)msg_ps->state));
367 
 
368 
  if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF)
369 
  {
370 
    struct mib_external_node *en;
371 
 
372 
    /* get_object_def() answer*/
373 
    en = msg_ps->ext_mib_node;
374 
 
375 
    /* translate answer into a known lifeform */
376 
    en->get_object_def_a(request_id, 1, &msg_ps->ext_oid.id[msg_ps->ext_oid.len - 1], &msg_ps->ext_object_def);
377 
    if (msg_ps->ext_object_def.instance != MIB_OBJECT_NONE)
378 
    {
379 
      msg_ps->state = SNMP_MSG_EXTERNAL_GET_VALUE;
380 
      en->get_value_q(request_id, &msg_ps->ext_object_def);
381 
    }
382 
    else
383 
    {
384 
      en->get_object_def_pc(request_id, 1, &msg_ps->ext_oid.id[msg_ps->ext_oid.len - 1]);
385 
      /* search failed, object id points to unknown object (nosuchname) */
386 
      snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME);
387 
    }
388 
  }
389 
  else if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_VALUE)
390 
  {
391 
    struct mib_external_node *en;
392 
    struct snmp_varbind *vb;
393 
 
394 
    /* get_value() answer */
395 
    en = msg_ps->ext_mib_node;
396 
 
397 
    vb = snmp_varbind_alloc(&msg_ps->ext_oid,
398 
                            msg_ps->ext_object_def.asn_type,
399 
                            msg_ps->ext_object_def.v_len);
400 
    if (vb != NULL)
401 
    {
402 
      en->get_value_a(request_id, &msg_ps->ext_object_def, vb->value_len, vb->value);
403 
      snmp_varbind_tail_add(&msg_ps->outvb, vb);
404 
      msg_ps->state = SNMP_MSG_SEARCH_OBJ;
405 
      msg_ps->vb_idx += 1;
406 
    }
407 
    else
408 
    {
409 
      en->get_value_pc(request_id, &msg_ps->ext_object_def);
410 
      LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_getnext_event: couldn't allocate outvb space\n"));
411 
      snmp_error_response(msg_ps,SNMP_ES_TOOBIG);
412 
    }
413 
  }
414 
 
415 
  while ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) &&
416 
         (msg_ps->vb_idx < msg_ps->invb.count))
417 
  {
418 
    struct mib_node *mn;
419 
    struct snmp_obj_id oid;
420 
 
421 
    if (msg_ps->vb_idx == 0)
422 
    {
423 
      msg_ps->vb_ptr = msg_ps->invb.head;
424 
    }
425 
    else
426 
    {
427 
      msg_ps->vb_ptr = msg_ps->vb_ptr->next;
428 
    }
429 
    if (snmp_iso_prefix_expand(msg_ps->vb_ptr->ident_len, msg_ps->vb_ptr->ident, &oid))
430 
    {
431 
      if (msg_ps->vb_ptr->ident_len > 3)
432 
      {
433 
        /* can offset ident_len and ident */
434 
        mn = snmp_expand_tree((struct mib_node*)&internet,
435 
                              msg_ps->vb_ptr->ident_len - 4,
436 
                              msg_ps->vb_ptr->ident + 4, &oid);
437 
      }
438 
      else
439 
      {
440 
        /* can't offset ident_len -4, ident + 4 */
441 
        mn = snmp_expand_tree((struct mib_node*)&internet, 0, NULL, &oid);
442 
      }
443 
    }
444 
    else
445 
    {
446 
      mn = NULL;
447 
    }
448 
    if (mn != NULL)
449 
    {
450 
      if (mn->node_type == MIB_NODE_EX)
451 
      {
452 
        /* external object */
453 
        struct mib_external_node *en = (struct mib_external_node*)mn;
454 
 
455 
        msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF;
456 
        /* save en && args in msg_ps!! */
457 
        msg_ps->ext_mib_node = en;
458 
        msg_ps->ext_oid = oid;
459 
 
460 
        en->get_object_def_q(en->addr_inf, request_id, 1, &oid.id[oid.len - 1]);
461 
      }
462 
      else
463 
      {
464 
        /* internal object */
465 
        struct obj_def object_def;
466 
        struct snmp_varbind *vb;
467 
 
468 
        msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF;
469 
        mn->get_object_def(1, &oid.id[oid.len - 1], &object_def);
470 
 
471 
        vb = snmp_varbind_alloc(&oid, object_def.asn_type, object_def.v_len);
472 
        if (vb != NULL)
473 
        {
474 
          msg_ps->state = SNMP_MSG_INTERNAL_GET_VALUE;
475 
          mn->get_value(&object_def, object_def.v_len, vb->value);
476 
          snmp_varbind_tail_add(&msg_ps->outvb, vb);
477 
          msg_ps->state = SNMP_MSG_SEARCH_OBJ;
478 
          msg_ps->vb_idx += 1;
479 
        }
480 
        else
481 
        {
482 
          LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv couldn't allocate outvb space\n"));
483 
          snmp_error_response(msg_ps,SNMP_ES_TOOBIG);
484 
        }
485 
      }
486 
    }
487 
    if (mn == NULL)
488 
    {
489 
      /* mn == NULL, noSuchName */
490 
      snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME);
491 
    }
492 
  }
493 
  if ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) &&
494 
      (msg_ps->vb_idx == msg_ps->invb.count))
495 
  {
496 
    snmp_ok_response(msg_ps);
497 
  }
498 
}
499 
 
500 
/**
501 
 * Service an internal or external event for SNMP SET.
502 
 *
503 
 * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1)
504 
 * @param msg_ps points to the assosicated message process state
505 
 */
506 
static void
507 
snmp_msg_set_event(u8_t request_id, struct snmp_msg_pstat *msg_ps)
508 
{
509 
  LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_set_event: msg_ps->state==%"U16_F"\n",(u16_t)msg_ps->state));
510 
 
511 
  if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF)
512 
  {
513 
    struct mib_external_node *en;
514 
    struct snmp_name_ptr np;
515 
 
516 
    /* get_object_def() answer*/
517 
    en = msg_ps->ext_mib_node;
518 
    np = msg_ps->ext_name_ptr;
519 
 
520 
    /* translate answer into a known lifeform */
521 
    en->get_object_def_a(request_id, np.ident_len, np.ident, &msg_ps->ext_object_def);
522 
    if (msg_ps->ext_object_def.instance != MIB_OBJECT_NONE)
523 
    {
524 
      msg_ps->state = SNMP_MSG_EXTERNAL_SET_TEST;
525 
      en->set_test_q(request_id, &msg_ps->ext_object_def);
526 
    }
527 
    else
528 
    {
529 
      en->get_object_def_pc(request_id, np.ident_len, np.ident);
530 
      /* search failed, object id points to unknown object (nosuchname) */
531 
      snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME);
532 
    }
533 
  }
534 
  else if (msg_ps->state == SNMP_MSG_EXTERNAL_SET_TEST)
535 
  {
536 
    struct mib_external_node *en;
537 
 
538 
    /* set_test() answer*/
539 
    en = msg_ps->ext_mib_node;
540 
 
541 
    if (msg_ps->ext_object_def.access == MIB_OBJECT_READ_WRITE)
542 
    {
543 
       if ((msg_ps->ext_object_def.asn_type == msg_ps->vb_ptr->value_type) &&
544 
           (en->set_test_a(request_id,&msg_ps->ext_object_def,
545 
                           msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value) != 0))
546 
      {
547 
        msg_ps->state = SNMP_MSG_SEARCH_OBJ;
548 
        msg_ps->vb_idx += 1;
549 
      }
550 
      else
551 
      {
552 
        en->set_test_pc(request_id,&msg_ps->ext_object_def);
553 
        /* bad value */
554 
        snmp_error_response(msg_ps,SNMP_ES_BADVALUE);
555 
      }
556 
    }
557 
    else
558 
    {
559 
      en->set_test_pc(request_id,&msg_ps->ext_object_def);
560 
      /* object not available for set */
561 
      snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME);
562 
    }
563 
  }
564 
  else if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF_S)
565 
  {
566 
    struct mib_external_node *en;
567 
    struct snmp_name_ptr np;
568 
 
569 
    /* get_object_def() answer*/
570 
    en = msg_ps->ext_mib_node;
571 
    np = msg_ps->ext_name_ptr;
572 
 
573 
    /* translate answer into a known lifeform */
574 
    en->get_object_def_a(request_id, np.ident_len, np.ident, &msg_ps->ext_object_def);
575 
    if (msg_ps->ext_object_def.instance != MIB_OBJECT_NONE)
576 
    {
577 
      msg_ps->state = SNMP_MSG_EXTERNAL_SET_VALUE;
578 
      en->set_value_q(request_id, &msg_ps->ext_object_def,
579 
                      msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value);
580 
    }
581 
    else
582 
    {
583 
      en->get_object_def_pc(request_id, np.ident_len, np.ident);
584 
      /* set_value failed, object has disappeared for some odd reason?? */
585 
      snmp_error_response(msg_ps,SNMP_ES_GENERROR);
586 
    }
587 
  }
588 
  else if (msg_ps->state == SNMP_MSG_EXTERNAL_SET_VALUE)
589 
  {
590 
    struct mib_external_node *en;
591 
 
592 
    /** set_value_a() */
593 
    en = msg_ps->ext_mib_node;
594 
    en->set_value_a(request_id, &msg_ps->ext_object_def,
595 
      msg_ps->vb_ptr->value_len, msg_ps->vb_ptr->value);
596 
 
597 
    /** @todo use set_value_pc() if toobig */
598 
    msg_ps->state = SNMP_MSG_INTERNAL_SET_VALUE;
599 
    msg_ps->vb_idx += 1;
600 
  }
601 
 
602 
  /* test all values before setting */
603 
  while ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) &&
604 
         (msg_ps->vb_idx < msg_ps->invb.count))
605 
  {
606 
    struct mib_node *mn;
607 
    struct snmp_name_ptr np;
608 
 
609 
    if (msg_ps->vb_idx == 0)
610 
    {
611 
      msg_ps->vb_ptr = msg_ps->invb.head;
612 
    }
613 
    else
614 
    {
615 
      msg_ps->vb_ptr = msg_ps->vb_ptr->next;
616 
    }
617 
    /** test object identifier for .iso.org.dod.internet prefix */
618 
    if (snmp_iso_prefix_tst(msg_ps->vb_ptr->ident_len,  msg_ps->vb_ptr->ident))
619 
    {
620 
      mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->vb_ptr->ident_len - 4,
621 
                             msg_ps->vb_ptr->ident + 4, &np);
622 
      if (mn != NULL)
623 
      {
624 
        if (mn->node_type == MIB_NODE_EX)
625 
        {
626 
          /* external object */
627 
          struct mib_external_node *en = (struct mib_external_node*)mn;
628 
 
629 
          msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF;
630 
          /* save en && args in msg_ps!! */
631 
          msg_ps->ext_mib_node = en;
632 
          msg_ps->ext_name_ptr = np;
633 
 
634 
          en->get_object_def_q(en->addr_inf, request_id, np.ident_len, np.ident);
635 
        }
636 
        else
637 
        {
638 
          /* internal object */
639 
          struct obj_def object_def;
640 
 
641 
          msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF;
642 
          mn->get_object_def(np.ident_len, np.ident, &object_def);
643 
          if (object_def.instance != MIB_OBJECT_NONE)
644 
          {
645 
            mn = mn;
646 
          }
647 
          else
648 
          {
649 
            /* search failed, object id points to unknown object (nosuchname) */
650 
            mn = NULL;
651 
          }
652 
          if (mn != NULL)
653 
          {
654 
            msg_ps->state = SNMP_MSG_INTERNAL_SET_TEST;
655 
 
656 
            if (object_def.access == MIB_OBJECT_READ_WRITE)
657 
            {
658 
              if ((object_def.asn_type == msg_ps->vb_ptr->value_type) &&
659 
                  (mn->set_test(&object_def,msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value) != 0))
660 
              {
661 
                msg_ps->state = SNMP_MSG_SEARCH_OBJ;
662 
                msg_ps->vb_idx += 1;
663 
              }
664 
              else
665 
              {
666 
                /* bad value */
667 
                snmp_error_response(msg_ps,SNMP_ES_BADVALUE);
668 
              }
669 
            }
670 
            else
671 
            {
672 
              /* object not available for set */
673 
              snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME);
674 
            }
675 
          }
676 
        }
677 
      }
678 
    }
679 
    else
680 
    {
681 
      mn = NULL;
682 
    }
683 
    if (mn == NULL)
684 
    {
685 
      /* mn == NULL, noSuchName */
686 
      snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME);
687 
    }
688 
  }
689 
 
690 
  if ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) &&
691 
      (msg_ps->vb_idx == msg_ps->invb.count))
692 
  {
693 
    msg_ps->vb_idx = 0;
694 
    msg_ps->state = SNMP_MSG_INTERNAL_SET_VALUE;
695 
  }
696 
 
697 
  /* set all values "atomically" (be as "atomic" as possible) */
698 
  while ((msg_ps->state == SNMP_MSG_INTERNAL_SET_VALUE) &&
699 
         (msg_ps->vb_idx < msg_ps->invb.count))
700 
  {
701 
    struct mib_node *mn;
702 
    struct snmp_name_ptr np;
703 
 
704 
    if (msg_ps->vb_idx == 0)
705 
    {
706 
      msg_ps->vb_ptr = msg_ps->invb.head;
707 
    }
708 
    else
709 
    {
710 
      msg_ps->vb_ptr = msg_ps->vb_ptr->next;
711 
    }
712 
    /* skip iso prefix test, was done previously while settesting() */
713 
    mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->vb_ptr->ident_len - 4,
714 
                           msg_ps->vb_ptr->ident + 4, &np);
715 
    /* check if object is still available
716 
       (e.g. external hot-plug thingy present?) */
717 
    if (mn != NULL)
718 
    {
719 
      if (mn->node_type == MIB_NODE_EX)
720 
      {
721 
        /* external object */
722 
        struct mib_external_node *en = (struct mib_external_node*)mn;
723 
 
724 
        msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF_S;
725 
        /* save en && args in msg_ps!! */
726 
        msg_ps->ext_mib_node = en;
727 
        msg_ps->ext_name_ptr = np;
728 
 
729 
        en->get_object_def_q(en->addr_inf, request_id, np.ident_len, np.ident);
730 
      }
731 
      else
732 
      {
733 
        /* internal object */
734 
        struct obj_def object_def;
735 
 
736 
        msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF_S;
737 
        mn->get_object_def(np.ident_len, np.ident, &object_def);
738 
        msg_ps->state = SNMP_MSG_INTERNAL_SET_VALUE;
739 
        mn->set_value(&object_def,msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value);
740 
        msg_ps->vb_idx += 1;
741 
      }
742 
    }
743 
  }
744 
  if ((msg_ps->state == SNMP_MSG_INTERNAL_SET_VALUE) &&
745 
      (msg_ps->vb_idx == msg_ps->invb.count))
746 
  {
747 
    /* simply echo the input if we can set it
748 
       @todo do we need to return the actual value?
749 
       e.g. if value is silently modified or behaves sticky? */
750 
    msg_ps->outvb = msg_ps->invb;
751 
    msg_ps->invb.head = NULL;
752 
    msg_ps->invb.tail = NULL;
753 
    msg_ps->invb.count = 0;
754 
    snmp_ok_response(msg_ps);
755 
  }
756 
}
757 
 
758 
 
759 
/**
760 
 * Handle one internal or external event.
761 
 * Called for one async event. (recv external/private answer)
762 
 *
763 
 * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1)
764 
 */
765 
void
766 
snmp_msg_event(u8_t request_id)
767 
{
768 
  struct snmp_msg_pstat *msg_ps;
769 
 
770 
  if (request_id < SNMP_CONCURRENT_REQUESTS)
771 
  {
772 
    msg_ps = &msg_input_list[request_id];
773 
    if (msg_ps->rt == SNMP_ASN1_PDU_GET_NEXT_REQ)
774 
    {
775 
      snmp_msg_getnext_event(request_id, msg_ps);
776 
    }
777 
    else if (msg_ps->rt == SNMP_ASN1_PDU_GET_REQ)
778 
    {
779 
      snmp_msg_get_event(request_id, msg_ps);
780 
    }
781 
    else if(msg_ps->rt == SNMP_ASN1_PDU_SET_REQ)
782 
    {
783 
      snmp_msg_set_event(request_id, msg_ps);
784 
    }
785 
  }
786 
}
787 
 
788 
 
789 
/* lwIP UDP receive callback function */
790 
static void
791 
snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port)
792 
{
793 
  struct udp_hdr *udphdr;
794 
 
795 
  /* suppress unused argument warning */
796 
  LWIP_UNUSED_ARG(arg);
797 
  /* peek in the UDP header (goto IP payload) */
798 
  if(pbuf_header(p, UDP_HLEN)){
799 
    LWIP_ASSERT("Can't move to UDP header", 0);
800 
    pbuf_free(p);
801 
    return;
802 
  }
803 
  udphdr = p->payload;
804 
 
805 
  /* check if datagram is really directed at us (including broadcast requests) */
806 
  if ((pcb == snmp1_pcb) && (ntohs(udphdr->dest) == SNMP_IN_PORT))
807 
  {
808 
    struct snmp_msg_pstat *msg_ps;
809 
    u8_t req_idx;
810 
 
811 
    /* traverse input message process list, look for SNMP_MSG_EMPTY */
812 
    msg_ps = &msg_input_list[0];
813 
    req_idx = 0;
814 
    while ((req_idx<SNMP_CONCURRENT_REQUESTS) && (msg_ps->state != SNMP_MSG_EMPTY))
815 
    {
816 
      req_idx++;
817 
      msg_ps++;
818 
    }
819 
    if (req_idx != SNMP_CONCURRENT_REQUESTS)
820 
    {
821 
      err_t err_ret;
822 
      u16_t payload_len;
823 
      u16_t payload_ofs;
824 
      u16_t varbind_ofs = 0;
825 
 
826 
      /* accepting request */
827 
      snmp_inc_snmpinpkts();
828 
      /* record used 'protocol control block' */
829 
      msg_ps->pcb = pcb;
830 
      /* source address (network order) */
831 
      msg_ps->sip = *addr;
832 
      /* source port (host order (lwIP oddity)) */
833 
      msg_ps->sp = port;
834 
      /* read UDP payload length from UDP header */
835 
      payload_len = ntohs(udphdr->len) - UDP_HLEN;
836 
 
837 
      /* adjust to UDP payload */
838 
      payload_ofs = UDP_HLEN;
839 
 
840 
      /* check total length, version, community, pdu type */
841 
      err_ret = snmp_pdu_header_check(p, payload_ofs, payload_len, &varbind_ofs, msg_ps);
842 
      if (((msg_ps->rt == SNMP_ASN1_PDU_GET_REQ) ||
843 
           (msg_ps->rt == SNMP_ASN1_PDU_GET_NEXT_REQ) ||
844 
           (msg_ps->rt == SNMP_ASN1_PDU_SET_REQ)) &&
845 
          ((msg_ps->error_status == SNMP_ES_NOERROR) &&
846 
           (msg_ps->error_index == 0)) )
847 
      {
848 
        /* Only accept requests and requests without error (be robust) */
849 
        err_ret = err_ret;
850 
      }
851 
      else
852 
      {
853 
        /* Reject response and trap headers or error requests as input! */
854 
        err_ret = ERR_ARG;
855 
      }
856 
      if (err_ret == ERR_OK)
857 
      {
858 
        LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv ok, community %s\n", msg_ps->community));
859 
 
860 
        /* Builds a list of variable bindings. Copy the varbinds from the pbuf
861 
          chain to glue them when these are divided over two or more pbuf's. */
862 
        err_ret = snmp_pdu_dec_varbindlist(p, varbind_ofs, &varbind_ofs, msg_ps);
863 
        if ((err_ret == ERR_OK) && (msg_ps->invb.count > 0))
864 
        {
865 
          /* we've decoded the incoming message, release input msg now */
866 
          pbuf_free(p);
867 
 
868 
          msg_ps->error_status = SNMP_ES_NOERROR;
869 
          msg_ps->error_index = 0;
870 
          /* find object for each variable binding */
871 
          msg_ps->state = SNMP_MSG_SEARCH_OBJ;
872 
          /* first variable binding from list to inspect */
873 
          msg_ps->vb_idx = 0;
874 
 
875 
          LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv varbind cnt=%"U16_F"\n",(u16_t)msg_ps->invb.count));
876 
 
877 
          /* handle input event and as much objects as possible in one go */
878 
          snmp_msg_event(req_idx);
879 
        }
880 
        else
881 
        {
882 
          /* varbind-list decode failed, or varbind list empty.
883 
             drop request silently, do not return error!
884 
             (errors are only returned for a specific varbind failure) */
885 
          pbuf_free(p);
886 
          LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_pdu_dec_varbindlist() failed\n"));
887 
        }
888 
      }
889 
      else
890 
      {
891 
        /* header check failed
892 
           drop request silently, do not return error! */
893 
        pbuf_free(p);
894 
        LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_pdu_header_check() failed\n"));
895 
      }
896 
    }
897 
    else
898 
    {
899 
      /* exceeding number of concurrent requests */
900 
      pbuf_free(p);
901 
    }
902 
  }
903 
  else
904 
  {
905 
    /* datagram not for us */
906 
    pbuf_free(p);
907 
  }
908 
}
909 
 
910 
/**
911 
 * Checks and decodes incoming SNMP message header, logs header errors.
912 
 *
913 
 * @param p points to pbuf chain of SNMP message (UDP payload)
914 
 * @param ofs points to first octet of SNMP message
915 
 * @param pdu_len the length of the UDP payload
916 
 * @param ofs_ret returns the ofset of the variable bindings
917 
 * @param m_stat points to the current message request state return
918 
 * @return
919 
 * - ERR_OK SNMP header is sane and accepted
920 
 * - ERR_ARG SNMP header is either malformed or rejected
921 
 */
922 
static err_t
923 
snmp_pdu_header_check(struct pbuf *p, u16_t ofs, u16_t pdu_len, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat)
924 
{
925 
  err_t derr;
926 
  u16_t len, ofs_base;
927 
  u8_t  len_octets;
928 
  u8_t  type;
929 
  s32_t version;
930 
 
931 
  ofs_base = ofs;
932 
  snmp_asn1_dec_type(p, ofs, &type);
933 
  derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
934 
  if ((derr != ERR_OK) ||
935 
      (pdu_len != (1 + len_octets + len)) ||
936 
      (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ)))
937 
  {
938 
    snmp_inc_snmpinasnparseerrs();
939 
    return ERR_ARG;
940 
  }
941 
  ofs += (1 + len_octets);
942 
  snmp_asn1_dec_type(p, ofs, &type);
943 
  derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
944 
  if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)))
945 
  {
946 
    /* can't decode or no integer (version) */
947 
    snmp_inc_snmpinasnparseerrs();
948 
    return ERR_ARG;
949 
  }
950 
  derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &version);
951 
  if (derr != ERR_OK)
952 
  {
953 
    /* can't decode */
954 
    snmp_inc_snmpinasnparseerrs();
955 
    return ERR_ARG;
956 
  }
957 
  if (version != 0)
958 
  {
959 
    /* not version 1 */
960 
    snmp_inc_snmpinbadversions();
961 
    return ERR_ARG;
962 
  }
963 
  ofs += (1 + len_octets + len);
964 
  snmp_asn1_dec_type(p, ofs, &type);
965 
  derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
966 
  if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR)))
967 
  {
968 
    /* can't decode or no octet string (community) */
969 
    snmp_inc_snmpinasnparseerrs();
970 
    return ERR_ARG;
971 
  }
972 
  derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, SNMP_COMMUNITY_STR_LEN, m_stat->community);
973 
  if (derr != ERR_OK)
974 
  {
975 
    snmp_inc_snmpinasnparseerrs();
976 
    return ERR_ARG;
977 
  }
978 
  /* add zero terminator */
979 
  len = ((len < (SNMP_COMMUNITY_STR_LEN))?(len):(SNMP_COMMUNITY_STR_LEN));
980 
  m_stat->community[len] = 0;
981 
  m_stat->com_strlen = len;
982 
  if (strncmp(snmp_publiccommunity, (const char*)m_stat->community, SNMP_COMMUNITY_STR_LEN) != 0)
983 
  {
984 
    /** @todo: move this if we need to check more names */
985 
    snmp_inc_snmpinbadcommunitynames();
986 
    snmp_authfail_trap();
987 
    return ERR_ARG;
988 
  }
989 
  ofs += (1 + len_octets + len);
990 
  snmp_asn1_dec_type(p, ofs, &type);
991 
  derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
992 
  if (derr != ERR_OK)
993 
  {
994 
    snmp_inc_snmpinasnparseerrs();
995 
    return ERR_ARG;
996 
  }
997 
  switch(type)
998 
  {
999 
    case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_REQ):
1000 
      /* GetRequest PDU */
1001 
      snmp_inc_snmpingetrequests();
1002 
      derr = ERR_OK;
1003 
      break;
1004 
    case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_NEXT_REQ):
1005 
      /* GetNextRequest PDU */
1006 
      snmp_inc_snmpingetnexts();
1007 
      derr = ERR_OK;
1008 
      break;
1009 
    case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_RESP):
1010 
      /* GetResponse PDU */
1011 
      snmp_inc_snmpingetresponses();
1012 
      derr = ERR_ARG;
1013 
      break;
1014 
    case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_SET_REQ):
1015 
      /* SetRequest PDU */
1016 
      snmp_inc_snmpinsetrequests();
1017 
      derr = ERR_OK;
1018 
      break;
1019 
    case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_TRAP):
1020 
      /* Trap PDU */
1021 
      snmp_inc_snmpintraps();
1022 
      derr = ERR_ARG;
1023 
      break;
1024 
    default:
1025 
      snmp_inc_snmpinasnparseerrs();
1026 
      derr = ERR_ARG;
1027 
      break;
1028 
  }
1029 
  if (derr != ERR_OK)
1030 
  {
1031 
    /* unsupported input PDU for this agent (no parse error) */
1032 
    return ERR_ARG;
1033 
  }
1034 
  m_stat->rt = type & 0x1F;
1035 
  ofs += (1 + len_octets);
1036 
  if (len != (pdu_len - (ofs - ofs_base)))
1037 
  {
1038 
    /* decoded PDU length does not equal actual payload length */
1039 
    snmp_inc_snmpinasnparseerrs();
1040 
    return ERR_ARG;
1041 
  }
1042 
  snmp_asn1_dec_type(p, ofs, &type);
1043 
  derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
1044 
  if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)))
1045 
  {
1046 
    /* can't decode or no integer (request ID) */
1047 
    snmp_inc_snmpinasnparseerrs();
1048 
    return ERR_ARG;
1049 
  }
1050 
  derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &m_stat->rid);
1051 
  if (derr != ERR_OK)
1052 
  {
1053 
    /* can't decode */
1054 
    snmp_inc_snmpinasnparseerrs();
1055 
    return ERR_ARG;
1056 
  }
1057 
  ofs += (1 + len_octets + len);
1058 
  snmp_asn1_dec_type(p, ofs, &type);
1059 
  derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
1060 
  if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)))
1061 
  {
1062 
    /* can't decode or no integer (error-status) */
1063 
    snmp_inc_snmpinasnparseerrs();
1064 
    return ERR_ARG;
1065 
  }
1066 
  /* must be noError (0) for incoming requests.
1067 
     log errors for mib-2 completeness and for debug purposes */
1068 
  derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &m_stat->error_status);
1069 
  if (derr != ERR_OK)
1070 
  {
1071 
    /* can't decode */
1072 
    snmp_inc_snmpinasnparseerrs();
1073 
    return ERR_ARG;
1074 
  }
1075 
  switch (m_stat->error_status)
1076 
  {
1077 
    case SNMP_ES_TOOBIG:
1078 
      snmp_inc_snmpintoobigs();
1079 
      break;
1080 
    case SNMP_ES_NOSUCHNAME:
1081 
      snmp_inc_snmpinnosuchnames();
1082 
      break;
1083 
    case SNMP_ES_BADVALUE:
1084 
      snmp_inc_snmpinbadvalues();
1085 
      break;
1086 
    case SNMP_ES_READONLY:
1087 
      snmp_inc_snmpinreadonlys();
1088 
      break;
1089 
    case SNMP_ES_GENERROR:
1090 
      snmp_inc_snmpingenerrs();
1091 
      break;
1092 
  }
1093 
  ofs += (1 + len_octets + len);
1094 
  snmp_asn1_dec_type(p, ofs, &type);
1095 
  derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
1096 
  if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)))
1097 
  {
1098 
    /* can't decode or no integer (error-index) */
1099 
    snmp_inc_snmpinasnparseerrs();
1100 
    return ERR_ARG;
1101 
  }
1102 
  /* must be 0 for incoming requests.
1103 
     decode anyway to catch bad integers (and dirty tricks) */
1104 
  derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &m_stat->error_index);
1105 
  if (derr != ERR_OK)
1106 
  {
1107 
    /* can't decode */
1108 
    snmp_inc_snmpinasnparseerrs();
1109 
    return ERR_ARG;
1110 
  }
1111 
  ofs += (1 + len_octets + len);
1112 
  *ofs_ret = ofs;
1113 
  return ERR_OK;
1114 
}
1115 
 
1116 
static err_t
1117 
snmp_pdu_dec_varbindlist(struct pbuf *p, u16_t ofs, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat)
1118 
{
1119 
  err_t derr;
1120 
  u16_t len, vb_len;
1121 
  u8_t  len_octets;
1122 
  u8_t type;
1123 
 
1124 
  /* variable binding list */
1125 
  snmp_asn1_dec_type(p, ofs, &type);
1126 
  derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &vb_len);
1127 
  if ((derr != ERR_OK) ||
1128 
      (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ)))
1129 
  {
1130 
    snmp_inc_snmpinasnparseerrs();
1131 
    return ERR_ARG;
1132 
  }
1133 
  ofs += (1 + len_octets);
1134 
 
1135 
  /* start with empty list */
1136 
  m_stat->invb.count = 0;
1137 
  m_stat->invb.head = NULL;
1138 
  m_stat->invb.tail = NULL;
1139 
 
1140 
  while (vb_len > 0)
1141 
  {
1142 
    struct snmp_obj_id oid, oid_value;
1143 
    struct snmp_varbind *vb;
1144 
 
1145 
    snmp_asn1_dec_type(p, ofs, &type);
1146 
    derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
1147 
    if ((derr != ERR_OK) ||
1148 
        (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ)) ||
1149 
        (len == 0) || (len > vb_len))
1150 
    {
1151 
      snmp_inc_snmpinasnparseerrs();
1152 
      /* free varbinds (if available) */
1153 
      snmp_varbind_list_free(&m_stat->invb);
1154 
      return ERR_ARG;
1155 
    }
1156 
    ofs += (1 + len_octets);
1157 
    vb_len -= (1 + len_octets);
1158 
 
1159 
    snmp_asn1_dec_type(p, ofs, &type);
1160 
    derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
1161 
    if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID)))
1162 
    {
1163 
      /* can't decode object name length */
1164 
      snmp_inc_snmpinasnparseerrs();
1165 
      /* free varbinds (if available) */
1166 
      snmp_varbind_list_free(&m_stat->invb);
1167 
      return ERR_ARG;
1168 
    }
1169 
    derr = snmp_asn1_dec_oid(p, ofs + 1 + len_octets, len, &oid);
1170 
    if (derr != ERR_OK)
1171 
    {
1172 
      /* can't decode object name */
1173 
      snmp_inc_snmpinasnparseerrs();
1174 
      /* free varbinds (if available) */
1175 
      snmp_varbind_list_free(&m_stat->invb);
1176 
      return ERR_ARG;
1177 
    }
1178 
    ofs += (1 + len_octets + len);
1179 
    vb_len -= (1 + len_octets + len);
1180 
 
1181 
    snmp_asn1_dec_type(p, ofs, &type);
1182 
    derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len);
1183 
    if (derr != ERR_OK)
1184 
    {
1185 
      /* can't decode object value length */
1186 
      snmp_inc_snmpinasnparseerrs();
1187 
      /* free varbinds (if available) */
1188 
      snmp_varbind_list_free(&m_stat->invb);
1189 
      return ERR_ARG;
1190 
    }
1191 
 
1192 
    switch (type)
1193 
    {
1194 
      case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG):
1195 
        vb = snmp_varbind_alloc(&oid, type, sizeof(s32_t));
1196 
        if (vb != NULL)
1197 
        {
1198 
          s32_t *vptr = vb->value;
1199 
 
1200 
          derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, vptr);
1201 
          snmp_varbind_tail_add(&m_stat->invb, vb);
1202 
        }
1203 
        else
1204 
        {
1205 
          derr = ERR_ARG;
1206 
        }
1207 
        break;
1208 
      case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_COUNTER):
1209 
      case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_GAUGE):
1210 
      case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS):
1211 
        vb = snmp_varbind_alloc(&oid, type, sizeof(u32_t));
1212 
        if (vb != NULL)
1213 
        {
1214 
          u32_t *vptr = vb->value;
1215 
 
1216 
          derr = snmp_asn1_dec_u32t(p, ofs + 1 + len_octets, len, vptr);
1217 
          snmp_varbind_tail_add(&m_stat->invb, vb);
1218 
        }
1219 
        else
1220 
        {
1221 
          derr = ERR_ARG;
1222 
        }
1223 
        break;
1224 
      case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR):
1225 
      case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE):
1226 
        vb = snmp_varbind_alloc(&oid, type, len);
1227 
        if (vb != NULL)
1228 
        {
1229 
          derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, vb->value_len, vb->value);
1230 
          snmp_varbind_tail_add(&m_stat->invb, vb);
1231 
        }
1232 
        else
1233 
        {
1234 
          derr = ERR_ARG;
1235 
        }
1236 
        break;
1237 
      case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL):
1238 
        vb = snmp_varbind_alloc(&oid, type, 0);
1239 
        if (vb != NULL)
1240 
        {
1241 
          snmp_varbind_tail_add(&m_stat->invb, vb);
1242 
          derr = ERR_OK;
1243 
        }
1244 
        else
1245 
        {
1246 
          derr = ERR_ARG;
1247 
        }
1248 
        break;
1249 
      case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID):
1250 
        derr = snmp_asn1_dec_oid(p, ofs + 1 + len_octets, len, &oid_value);
1251 
        if (derr == ERR_OK)
1252 
        {
1253 
          vb = snmp_varbind_alloc(&oid, type, oid_value.len * sizeof(s32_t));
1254 
          if (vb != NULL)
1255 
          {
1256 
            u8_t i = oid_value.len;
1257 
            s32_t *vptr = vb->value;
1258 
 
1259 
            while(i > 0)
1260 
            {
1261 
              i--;
1262 
              vptr[i] = oid_value.id[i];
1263 
            }
1264 
            snmp_varbind_tail_add(&m_stat->invb, vb);
1265 
            derr = ERR_OK;
1266 
          }
1267 
          else
1268 
          {
1269 
            derr = ERR_ARG;
1270 
          }
1271 
        }
1272 
        break;
1273 
      case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR):
1274 
        if (len == 4)
1275 
        {
1276 
          /* must be exactly 4 octets! */
1277 
          vb = snmp_varbind_alloc(&oid, type, 4);
1278 
          if (vb != NULL)
1279 
          {
1280 
            derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, vb->value_len, vb->value);
1281 
            snmp_varbind_tail_add(&m_stat->invb, vb);
1282 
          }
1283 
          else
1284 
          {
1285 
            derr = ERR_ARG;
1286 
          }
1287 
        }
1288 
        else
1289 
        {
1290 
          derr = ERR_ARG;
1291 
        }
1292 
        break;
1293 
      default:
1294 
        derr = ERR_ARG;
1295 
        break;
1296 
    }
1297 
    if (derr != ERR_OK)
1298 
    {
1299 
      snmp_inc_snmpinasnparseerrs();
1300 
      /* free varbinds (if available) */
1301 
      snmp_varbind_list_free(&m_stat->invb);
1302 
      return ERR_ARG;
1303 
    }
1304 
    ofs += (1 + len_octets + len);
1305 
    vb_len -= (1 + len_octets + len);
1306 
  }
1307 
 
1308 
  if (m_stat->rt == SNMP_ASN1_PDU_SET_REQ)
1309 
  {
1310 
    snmp_add_snmpintotalsetvars(m_stat->invb.count);
1311 
  }
1312 
  else
1313 
  {
1314 
    snmp_add_snmpintotalreqvars(m_stat->invb.count);
1315 
  }
1316 
 
1317 
  *ofs_ret = ofs;
1318 
  return ERR_OK;
1319 
}
1320 
 
1321 
struct snmp_varbind*
1322 
snmp_varbind_alloc(struct snmp_obj_id *oid, u8_t type, u8_t len)
1323 
{
1324 
  struct snmp_varbind *vb;
1325 
 
1326 
  vb = (struct snmp_varbind *)mem_malloc(sizeof(struct snmp_varbind));
1327 
  LWIP_ASSERT("vb != NULL",vb != NULL);
1328 
  if (vb != NULL)
1329 
  {
1330 
    u8_t i;
1331 
 
1332 
    vb->next = NULL;
1333 
    vb->prev = NULL;
1334 
    i = oid->len;
1335 
    vb->ident_len = i;
1336 
    if (i > 0)
1337 
    {
1338 
      /* allocate array of s32_t for our object identifier */
1339 
      vb->ident = (s32_t*)mem_malloc(sizeof(s32_t) * i);
1340 
      LWIP_ASSERT("vb->ident != NULL",vb->ident != NULL);
1341 
      if (vb->ident == NULL)
1342 
      {
1343 
        mem_free(vb);
1344 
        return NULL;
1345 
      }
1346 
      while(i > 0)
1347 
      {
1348 
        i--;
1349 
        vb->ident[i] = oid->id[i];
1350 
      }
1351 
    }
1352 
    else
1353 
    {
1354 
      /* i == 0, pass zero length object identifier */
1355 
      vb->ident = NULL;
1356 
    }
1357 
    vb->value_type = type;
1358 
    vb->value_len = len;
1359 
    if (len > 0)
1360 
    {
1361 
      /* allocate raw bytes for our object value */
1362 
      vb->value = mem_malloc(len);
1363 
      LWIP_ASSERT("vb->value != NULL",vb->value != NULL);
1364 
      if (vb->value == NULL)
1365 
      {
1366 
        if (vb->ident != NULL)
1367 
        {
1368 
          mem_free(vb->ident);
1369 
        }
1370 
        mem_free(vb);
1371 
        return NULL;
1372 
      }
1373 
    }
1374 
    else
1375 
    {
1376 
      /* ASN1_NUL type, or zero length ASN1_OC_STR */
1377 
      vb->value = NULL;
1378 
    }
1379 
  }
1380 
  return vb;
1381 
}
1382 
 
1383 
void
1384 
snmp_varbind_free(struct snmp_varbind *vb)
1385 
{
1386 
  if (vb->value != NULL )
1387 
  {
1388 
    mem_free(vb->value);
1389 
  }
1390 
  if (vb->ident != NULL )
1391 
  {
1392 
    mem_free(vb->ident);
1393 
  }
1394 
  mem_free(vb);
1395 
}
1396 
 
1397 
void
1398 
snmp_varbind_list_free(struct snmp_varbind_root *root)
1399 
{
1400 
  struct snmp_varbind *vb, *prev;
1401 
 
1402 
  vb = root->tail;
1403 
  while ( vb != NULL )
1404 
  {
1405 
    prev = vb->prev;
1406 
    snmp_varbind_free(vb);
1407 
    vb = prev;
1408 
  }
1409 
  root->count = 0;
1410 
  root->head = NULL;
1411 
  root->tail = NULL;
1412 
}
1413 
 
1414 
void
1415 
snmp_varbind_tail_add(struct snmp_varbind_root *root, struct snmp_varbind *vb)
1416 
{
1417 
  if (root->count == 0)
1418 
  {
1419 
    /* add first varbind to list */
1420 
    root->head = vb;
1421 
    root->tail = vb;
1422 
  }
1423 
  else
1424 
  {
1425 
    /* add nth varbind to list tail */
1426 
    root->tail->next = vb;
1427 
    vb->prev = root->tail;
1428 
    root->tail = vb;
1429 
  }
1430 
  root->count += 1;
1431 
}
1432 
 
1433 
struct snmp_varbind*
1434 
snmp_varbind_tail_remove(struct snmp_varbind_root *root)
1435 
{
1436 
  struct snmp_varbind* vb;
1437 
 
1438 
  if (root->count > 0)
1439 
  {
1440 
    /* remove tail varbind */
1441 
    vb = root->tail;
1442 
    root->tail = vb->prev;
1443 
    vb->prev->next = NULL;
1444 
    root->count -= 1;
1445 
  }
1446 
  else
1447 
  {
1448 
    /* nothing to remove */
1449 
    vb = NULL;
1450 
  }
1451 
  return vb;
1452 
}
1453 
 
1454 
#endif /* LWIP_SNMP */

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