1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
|
/*
* Copyright (c) 2001-2003
* Fraunhofer Institute for Open Communication Systems (FhG Fokus).
* All rights reserved.
*
* Author: Harti Brandt <harti@freebsd.org>
*
* Redistribution of this software and documentation and use in source and
* binary forms, with or without modification, are permitted provided that
* the following conditions are met:
*
* 1. Redistributions of source code or documentation must retain the above
* copyright notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE AND DOCUMENTATION IS PROVIDED BY FRAUNHOFER FOKUS
* AND ITS CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* FRAUNHOFER FOKUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $Begemot: bsnmp/lib/snmpagent.c,v 1.16 2003/12/03 09:55:58 hbb Exp $
*
* SNMP Agent functions
*/
#include <sys/types.h>
#include <sys/queue.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdarg.h>
#include <string.h>
#include "asn1.h"
#include "snmp.h"
#include "snmppriv.h"
#include "snmpagent.h"
static void snmp_debug_func(const char *fmt, ...);
void (*snmp_debug)(const char *fmt, ...) = snmp_debug_func;
struct snmp_node *tree;
u_int tree_size;
/*
* Structure to hold dependencies during SET processing
* The last two members of this structure must be the
* dependency visible by the user and the user data.
*/
struct depend {
TAILQ_ENTRY(depend) link;
size_t len; /* size of data part */
snmp_depop_t func;
struct snmp_dependency dep;
u_char data[];
};
TAILQ_HEAD(depend_list, depend);
/*
* Structure to hold atfinish functions during SET processing.
*/
struct finish {
STAILQ_ENTRY(finish) link;
snmp_set_finish_t func;
void *arg;
};
STAILQ_HEAD(finish_list, finish);
/*
* Set context
*/
struct context {
struct snmp_context ctx;
struct depend_list dlist;
struct finish_list flist;
const struct snmp_node *node[SNMP_MAX_BINDINGS];
struct snmp_scratch scratch[SNMP_MAX_BINDINGS];
struct depend *depend;
};
#define TR(W) (snmp_trace & SNMP_TRACE_##W)
u_int snmp_trace = 0;
static char oidbuf[ASN_OIDSTRLEN];
/*
* Allocate a context
*/
struct snmp_context *
snmp_init_context(void)
{
struct context *context;
if ((context = malloc(sizeof(*context))) == NULL)
return (NULL);
memset(context, 0, sizeof(*context));
TAILQ_INIT(&context->dlist);
STAILQ_INIT(&context->flist);
return (&context->ctx);
}
/*
* Find a variable for SET/GET and the first GETBULK pass.
* Return the node pointer. If the search fails, set the errp to
* the correct SNMPv2 GET exception code.
*/
static struct snmp_node *
find_node(const struct snmp_value *value, enum snmp_syntax *errp)
{
struct snmp_node *tp;
if (TR(FIND))
snmp_debug("find: searching %s",
asn_oid2str_r(&value->var, oidbuf));
/*
* If we have an exact match (the entry in the table is a
* sub-oid from the variable) we have found what we are for.
* If the table oid is higher than the variable, there is no match.
*/
for (tp = tree; tp < tree + tree_size; tp++) {
if (asn_is_suboid(&tp->oid, &value->var))
goto found;
if (asn_compare_oid(&tp->oid, &value->var) >= 0)
break;
}
if (TR(FIND))
snmp_debug("find: no match");
*errp = SNMP_SYNTAX_NOSUCHOBJECT;
return (NULL);
found:
/* leafs must have a 0 instance identifier */
if (tp->type == SNMP_NODE_LEAF &&
(value->var.len != tp->oid.len + 1 ||
value->var.subs[tp->oid.len] != 0)) {
if (TR(FIND))
snmp_debug("find: bad leaf index");
*errp = SNMP_SYNTAX_NOSUCHINSTANCE;
return (NULL);
}
if (TR(FIND))
snmp_debug("find: found %s",
asn_oid2str_r(&value->var, oidbuf));
return (tp);
}
static struct snmp_node *
find_subnode(const struct snmp_value *value)
{
struct snmp_node *tp;
for (tp = tree; tp < tree + tree_size; tp++) {
if (asn_is_suboid(&value->var, &tp->oid))
return (tp);
}
return (NULL);
}
/*
* Execute a GET operation. The tree is rooted at the global 'root'.
* Build the response PDU on the fly. If the return code is SNMP_RET_ERR
* the pdu error status and index will be set.
*/
enum snmp_ret
snmp_get(struct snmp_pdu *pdu, struct asn_buf *resp_b,
struct snmp_pdu *resp, void *data)
{
int ret;
u_int i;
struct snmp_node *tp;
enum snmp_syntax except;
struct context context;
enum asn_err err;
memset(&context, 0, sizeof(context));
context.ctx.data = data;
memset(resp, 0, sizeof(*resp));
strcpy(resp->community, pdu->community);
resp->version = pdu->version;
resp->type = SNMP_PDU_RESPONSE;
resp->request_id = pdu->request_id;
resp->version = pdu->version;
if (snmp_pdu_encode_header(resp_b, resp) != SNMP_CODE_OK)
/* cannot even encode header - very bad */
return (SNMP_RET_IGN);
for (i = 0; i < pdu->nbindings; i++) {
resp->bindings[i].var = pdu->bindings[i].var;
if ((tp = find_node(&pdu->bindings[i], &except)) == NULL) {
if (pdu->version == SNMP_V1) {
if (TR(GET))
snmp_debug("get: nosuchname");
pdu->error_status = SNMP_ERR_NOSUCHNAME;
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
if (TR(GET))
snmp_debug("get: exception %u", except);
resp->bindings[i].syntax = except;
} else {
/* call the action to fetch the value. */
resp->bindings[i].syntax = tp->syntax;
ret = (*tp->op)(&context.ctx, &resp->bindings[i],
tp->oid.len, tp->index, SNMP_OP_GET);
if (TR(GET))
snmp_debug("get: action returns %d", ret);
if (ret == SNMP_ERR_NOSUCHNAME) {
if (pdu->version == SNMP_V1) {
pdu->error_status = SNMP_ERR_NOSUCHNAME;
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
if (TR(GET))
snmp_debug("get: exception noSuchInstance");
resp->bindings[i].syntax = SNMP_SYNTAX_NOSUCHINSTANCE;
} else if (ret != SNMP_ERR_NOERROR) {
pdu->error_status = SNMP_ERR_GENERR;
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
}
resp->nbindings++;
err = snmp_binding_encode(resp_b, &resp->bindings[i]);
if (err == ASN_ERR_EOBUF) {
pdu->error_status = SNMP_ERR_TOOBIG;
pdu->error_index = 0;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
if (err != ASN_ERR_OK) {
if (TR(GET))
snmp_debug("get: binding encoding: %u", err);
pdu->error_status = SNMP_ERR_GENERR;
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
}
return (snmp_fix_encoding(resp_b, resp));
}
static struct snmp_node *
next_node(const struct snmp_value *value, int *pnext)
{
struct snmp_node *tp;
if (TR(FIND))
snmp_debug("next: searching %s",
asn_oid2str_r(&value->var, oidbuf));
*pnext = 0;
for (tp = tree; tp < tree + tree_size; tp++) {
if (asn_is_suboid(&tp->oid, &value->var)) {
/* the tree OID is a sub-oid of the requested OID. */
if (tp->type == SNMP_NODE_LEAF) {
if (tp->oid.len == value->var.len) {
/* request for scalar type */
if (TR(FIND))
snmp_debug("next: found scalar %s",
asn_oid2str_r(&tp->oid, oidbuf));
return (tp);
}
/* try next */
} else {
if (TR(FIND))
snmp_debug("next: found column %s",
asn_oid2str_r(&tp->oid, oidbuf));
return (tp);
}
} else if (asn_is_suboid(&value->var, &tp->oid) ||
asn_compare_oid(&tp->oid, &value->var) >= 0) {
if (TR(FIND))
snmp_debug("next: found %s",
asn_oid2str_r(&tp->oid, oidbuf));
*pnext = 1;
return (tp);
}
}
if (TR(FIND))
snmp_debug("next: failed");
return (NULL);
}
static enum snmp_ret
do_getnext(struct context *context, const struct snmp_value *inb,
struct snmp_value *outb, struct snmp_pdu *pdu)
{
const struct snmp_node *tp;
int ret, next;
if ((tp = next_node(inb, &next)) == NULL)
goto eofMib;
/* retain old variable if we are doing a GETNEXT on an exact
* matched leaf only */
if (tp->type == SNMP_NODE_LEAF || next)
outb->var = tp->oid;
else
outb->var = inb->var;
for (;;) {
outb->syntax = tp->syntax;
if (tp->type == SNMP_NODE_LEAF) {
/* make a GET operation */
outb->var.subs[outb->var.len++] = 0;
ret = (*tp->op)(&context->ctx, outb, tp->oid.len,
tp->index, SNMP_OP_GET);
} else {
/* make a GETNEXT */
ret = (*tp->op)(&context->ctx, outb, tp->oid.len,
tp->index, SNMP_OP_GETNEXT);
}
if (ret != SNMP_ERR_NOSUCHNAME) {
/* got something */
if (ret != SNMP_ERR_NOERROR && TR(GETNEXT))
snmp_debug("getnext: %s returns %u",
asn_oid2str(&outb->var), ret);
break;
}
/* object has no data - try next */
if (++tp == tree + tree_size)
break;
outb->var = tp->oid;
}
if (ret == SNMP_ERR_NOSUCHNAME) {
eofMib:
outb->var = inb->var;
if (pdu->version == SNMP_V1) {
pdu->error_status = SNMP_ERR_NOSUCHNAME;
return (SNMP_RET_ERR);
}
outb->syntax = SNMP_SYNTAX_ENDOFMIBVIEW;
} else if (ret != SNMP_ERR_NOERROR) {
pdu->error_status = SNMP_ERR_GENERR;
return (SNMP_RET_ERR);
}
return (SNMP_RET_OK);
}
/*
* Execute a GETNEXT operation. The tree is rooted at the global 'root'.
* Build the response PDU on the fly. The return is:
*/
enum snmp_ret
snmp_getnext(struct snmp_pdu *pdu, struct asn_buf *resp_b,
struct snmp_pdu *resp, void *data)
{
struct context context;
u_int i;
enum asn_err err;
enum snmp_ret result;
memset(&context, 0, sizeof(context));
context.ctx.data = data;
memset(resp, 0, sizeof(*resp));
strcpy(resp->community, pdu->community);
resp->type = SNMP_PDU_RESPONSE;
resp->request_id = pdu->request_id;
resp->version = pdu->version;
if (snmp_pdu_encode_header(resp_b, resp))
return (SNMP_RET_IGN);
for (i = 0; i < pdu->nbindings; i++) {
result = do_getnext(&context, &pdu->bindings[i],
&resp->bindings[i], pdu);
if (result != SNMP_RET_OK) {
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (result);
}
resp->nbindings++;
err = snmp_binding_encode(resp_b, &resp->bindings[i]);
if (err == ASN_ERR_EOBUF) {
pdu->error_status = SNMP_ERR_TOOBIG;
pdu->error_index = 0;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
if (err != ASN_ERR_OK) {
if (TR(GET))
snmp_debug("getnext: binding encoding: %u", err);
pdu->error_status = SNMP_ERR_GENERR;
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
}
return (snmp_fix_encoding(resp_b, resp));
}
enum snmp_ret
snmp_getbulk(struct snmp_pdu *pdu, struct asn_buf *resp_b,
struct snmp_pdu *resp, void *data)
{
struct context context;
u_int i;
int cnt;
u_int non_rep;
int eomib;
enum snmp_ret result;
enum asn_err err;
memset(&context, 0, sizeof(context));
context.ctx.data = data;
memset(resp, 0, sizeof(*resp));
strcpy(resp->community, pdu->community);
resp->version = pdu->version;
resp->type = SNMP_PDU_RESPONSE;
resp->request_id = pdu->request_id;
resp->version = pdu->version;
if (snmp_pdu_encode_header(resp_b, resp) != SNMP_CODE_OK)
/* cannot even encode header - very bad */
return (SNMP_RET_IGN);
if ((non_rep = pdu->error_status) > pdu->nbindings)
non_rep = pdu->nbindings;
/* non-repeaters */
for (i = 0; i < non_rep; i++) {
result = do_getnext(&context, &pdu->bindings[i],
&resp->bindings[resp->nbindings], pdu);
if (result != SNMP_RET_OK) {
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (result);
}
err = snmp_binding_encode(resp_b,
&resp->bindings[resp->nbindings++]);
if (err == ASN_ERR_EOBUF)
goto done;
if (err != ASN_ERR_OK) {
if (TR(GET))
snmp_debug("getnext: binding encoding: %u", err);
pdu->error_status = SNMP_ERR_GENERR;
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
}
if (non_rep == pdu->nbindings)
goto done;
/* repeates */
for (cnt = 0; cnt < pdu->error_index; cnt++) {
eomib = 1;
for (i = non_rep; i < pdu->nbindings; i++) {
if (cnt == 0)
result = do_getnext(&context, &pdu->bindings[i],
&resp->bindings[resp->nbindings], pdu);
else
result = do_getnext(&context,
&resp->bindings[resp->nbindings -
(pdu->nbindings - non_rep)],
&resp->bindings[resp->nbindings], pdu);
if (result != SNMP_RET_OK) {
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (result);
}
if (resp->bindings[resp->nbindings].syntax !=
SNMP_SYNTAX_ENDOFMIBVIEW)
eomib = 0;
err = snmp_binding_encode(resp_b,
&resp->bindings[resp->nbindings++]);
if (err == ASN_ERR_EOBUF)
goto done;
if (err != ASN_ERR_OK) {
if (TR(GET))
snmp_debug("getnext: binding encoding: %u", err);
pdu->error_status = SNMP_ERR_GENERR;
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
}
if (eomib)
break;
}
done:
return (snmp_fix_encoding(resp_b, resp));
}
/*
* Rollback a SET operation. Failed index is 'i'.
*/
static void
rollback(struct context *context, struct snmp_pdu *pdu, u_int i)
{
struct snmp_value *b;
const struct snmp_node *np;
int ret;
while (i-- > 0) {
b = &pdu->bindings[i];
np = context->node[i];
context->ctx.scratch = &context->scratch[i];
ret = (*np->op)(&context->ctx, b, np->oid.len, np->index,
SNMP_OP_ROLLBACK);
if (ret != SNMP_ERR_NOERROR) {
snmp_error("set: rollback failed (%d) on variable %s "
"index %u", ret, asn_oid2str(&b->var), i);
if (pdu->version != SNMP_V1) {
pdu->error_status = SNMP_ERR_UNDO_FAILED;
pdu->error_index = 0;
}
}
}
}
/*
* Commit dependencies.
*/
int
snmp_dep_commit(struct snmp_context *ctx)
{
struct context *context = (struct context *)ctx;
int ret;
TAILQ_FOREACH(context->depend, &context->dlist, link) {
ctx->dep = &context->depend->dep;
if (TR(SET))
snmp_debug("set: dependency commit %s",
asn_oid2str(&ctx->dep->obj));
ret = context->depend->func(ctx, ctx->dep, SNMP_DEPOP_COMMIT);
if (ret != SNMP_ERR_NOERROR) {
if (TR(SET))
snmp_debug("set: dependency failed %d", ret);
return (ret);
}
}
return (SNMP_ERR_NOERROR);
}
/*
* Rollback dependencies
*/
int
snmp_dep_rollback(struct snmp_context *ctx)
{
struct context *context = (struct context *)ctx;
int ret, ret1;
char objbuf[ASN_OIDSTRLEN];
char idxbuf[ASN_OIDSTRLEN];
ret1 = SNMP_ERR_NOERROR;
while ((context->depend =
TAILQ_PREV(context->depend, depend_list, link)) != NULL) {
ctx->dep = &context->depend->dep;
if (TR(SET))
snmp_debug("set: dependency rollback %s",
asn_oid2str(&ctx->dep->obj));
ret = context->depend->func(ctx, ctx->dep, SNMP_DEPOP_ROLLBACK);
if (ret != SNMP_ERR_NOERROR) {
snmp_debug("set: dep rollback returns %u: %s %s", ret,
asn_oid2str_r(&ctx->dep->obj, objbuf),
asn_oid2str_r(&ctx->dep->idx, idxbuf));
if (ret1 == SNMP_ERR_NOERROR)
ret1 = ret;
}
}
return (ret1);
}
/*
* Do a SET operation.
*/
enum snmp_ret
snmp_set(struct snmp_pdu *pdu, struct asn_buf *resp_b,
struct snmp_pdu *resp, void *data)
{
int ret;
u_int i;
enum snmp_ret code;
enum asn_err asnerr;
struct context context;
const struct snmp_node *np;
struct finish *f;
struct depend *d;
struct snmp_value *b;
enum snmp_syntax except;
memset(&context, 0, sizeof(context));
TAILQ_INIT(&context.dlist);
STAILQ_INIT(&context.flist);
context.ctx.data = data;
memset(resp, 0, sizeof(*resp));
strcpy(resp->community, pdu->community);
resp->type = SNMP_PDU_RESPONSE;
resp->request_id = pdu->request_id;
resp->version = pdu->version;
if (snmp_pdu_encode_header(resp_b, resp))
return (SNMP_RET_IGN);
/*
* 1. Find all nodes, check that they are writeable and
* that the syntax is ok, copy over the binding to the response.
*/
for (i = 0; i < pdu->nbindings; i++) {
b = &pdu->bindings[i];
if ((np = context.node[i] = find_node(b, &except)) == NULL) {
/* not found altogether or LEAF with wrong index */
if (TR(SET))
snmp_debug("set: node not found %s",
asn_oid2str_r(&b->var, oidbuf));
if (pdu->version == SNMP_V1) {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_NOSUCHNAME;
} else if ((np = find_subnode(b)) != NULL) {
/* 2. intermediate object */
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_NOT_WRITEABLE;
} else if (except == SNMP_SYNTAX_NOSUCHOBJECT) {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_NO_ACCESS;
} else {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_NO_CREATION;
}
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
/*
* 2. write/createable?
* Can check this for leafs only, because in v2 we have
* to differentiate between NOT_WRITEABLE and NO_CREATION
* and only the action routine for COLUMNS knows, whether
* a column exists.
*/
if (np->type == SNMP_NODE_LEAF &&
!(np->flags & SNMP_NODE_CANSET)) {
if (pdu->version == SNMP_V1) {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_NOSUCHNAME;
} else {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_NOT_WRITEABLE;
}
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
/*
* 3. Ensure the right syntax
*/
if (np->syntax != b->syntax) {
if (pdu->version == SNMP_V1) {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_BADVALUE; /* v2: wrongType */
} else {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_WRONG_TYPE;
}
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
/*
* 4. Copy binding
*/
if (snmp_value_copy(&resp->bindings[i], b)) {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_GENERR;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
asnerr = snmp_binding_encode(resp_b, &resp->bindings[i]);
if (asnerr == ASN_ERR_EOBUF) {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_TOOBIG;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
} else if (asnerr != ASN_ERR_OK) {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_GENERR;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
resp->nbindings++;
}
code = SNMP_RET_OK;
/*
* 2. Call the SET method for each node. If a SET fails, rollback
* everything. Map error codes depending on the version.
*/
for (i = 0; i < pdu->nbindings; i++) {
b = &pdu->bindings[i];
np = context.node[i];
context.ctx.var_index = i + 1;
context.ctx.scratch = &context.scratch[i];
ret = (*np->op)(&context.ctx, b, np->oid.len, np->index,
SNMP_OP_SET);
if (TR(SET))
snmp_debug("set: action %s returns %d", np->name, ret);
if (pdu->version == SNMP_V1) {
switch (ret) {
case SNMP_ERR_NO_ACCESS:
ret = SNMP_ERR_NOSUCHNAME;
break;
case SNMP_ERR_WRONG_TYPE:
/* should no happen */
ret = SNMP_ERR_BADVALUE;
break;
case SNMP_ERR_WRONG_LENGTH:
ret = SNMP_ERR_BADVALUE;
break;
case SNMP_ERR_WRONG_ENCODING:
/* should not happen */
ret = SNMP_ERR_BADVALUE;
break;
case SNMP_ERR_WRONG_VALUE:
ret = SNMP_ERR_BADVALUE;
break;
case SNMP_ERR_NO_CREATION:
ret = SNMP_ERR_NOSUCHNAME;
break;
case SNMP_ERR_INCONS_VALUE:
ret = SNMP_ERR_BADVALUE;
break;
case SNMP_ERR_RES_UNAVAIL:
ret = SNMP_ERR_GENERR;
break;
case SNMP_ERR_COMMIT_FAILED:
ret = SNMP_ERR_GENERR;
break;
case SNMP_ERR_UNDO_FAILED:
ret = SNMP_ERR_GENERR;
break;
case SNMP_ERR_AUTH_ERR:
/* should not happen */
ret = SNMP_ERR_GENERR;
break;
case SNMP_ERR_NOT_WRITEABLE:
ret = SNMP_ERR_NOSUCHNAME;
break;
case SNMP_ERR_INCONS_NAME:
ret = SNMP_ERR_BADVALUE;
break;
}
}
if (ret != SNMP_ERR_NOERROR) {
pdu->error_index = i + 1;
pdu->error_status = ret;
rollback(&context, pdu, i);
snmp_pdu_free(resp);
code = SNMP_RET_ERR;
goto errout;
}
}
/*
* 3. Call dependencies
*/
if (TR(SET))
snmp_debug("set: set operations ok");
if ((ret = snmp_dep_commit(&context.ctx)) != SNMP_ERR_NOERROR) {
pdu->error_status = ret;
pdu->error_index = context.ctx.var_index;
if ((ret = snmp_dep_rollback(&context.ctx)) != SNMP_ERR_NOERROR) {
if (pdu->version != SNMP_V1) {
pdu->error_status = SNMP_ERR_UNDO_FAILED;
pdu->error_index = 0;
}
}
rollback(&context, pdu, i);
snmp_pdu_free(resp);
code = SNMP_RET_ERR;
goto errout;
}
/*
* 4. Commit and copy values from the original packet to the response.
* This is not the commit operation from RFC 1905 but rather an
* 'FREE RESOURCES' operation. It shouldn't fail.
*/
if (TR(SET))
snmp_debug("set: commiting");
for (i = 0; i < pdu->nbindings; i++) {
b = &resp->bindings[i];
np = context.node[i];
context.ctx.var_index = i + 1;
context.ctx.scratch = &context.scratch[i];
ret = (*np->op)(&context.ctx, b, np->oid.len, np->index,
SNMP_OP_COMMIT);
if (ret != SNMP_ERR_NOERROR)
snmp_error("set: commit failed (%d) on"
" variable %s index %u", ret,
asn_oid2str_r(&b->var, oidbuf), i);
}
if (snmp_fix_encoding(resp_b, resp) != SNMP_CODE_OK) {
snmp_error("set: fix_encoding failed");
snmp_pdu_free(resp);
code = SNMP_RET_IGN;
}
/*
* Done
*/
errout:
while ((d = TAILQ_FIRST(&context.dlist)) != NULL) {
TAILQ_REMOVE(&context.dlist, d, link);
free(d);
}
/*
* call finish function
*/
while ((f = STAILQ_FIRST(&context.flist)) != NULL) {
STAILQ_REMOVE_HEAD(&context.flist, link);
(*f->func)(&context.ctx, code != SNMP_RET_OK, f->arg);
free(f);
}
if (TR(SET))
snmp_debug("set: returning %d", code);
return (code);
}
/*
* Lookup a dependency. If it doesn't exist, create one
*/
struct snmp_dependency *
snmp_dep_lookup(struct snmp_context *ctx, const struct asn_oid *obj,
const struct asn_oid *idx, size_t len, snmp_depop_t func)
{
struct context *context;
struct depend *d;
context = (struct context *)(void *)
((char *)ctx - offsetof(struct context, ctx));
if (TR(DEPEND)) {
snmp_debug("depend: looking for %s", asn_oid2str(obj));
if (idx)
snmp_debug("depend: index is %s", asn_oid2str(idx));
}
TAILQ_FOREACH(d, &context->dlist, link)
if (asn_compare_oid(obj, &d->dep.obj) == 0 &&
((idx == NULL && d->dep.idx.len == 0) ||
(idx != NULL && asn_compare_oid(idx, &d->dep.idx) == 0))) {
if(TR(DEPEND))
snmp_debug("depend: found");
return (&d->dep);
}
if(TR(DEPEND))
snmp_debug("depend: creating");
if ((d = malloc(offsetof(struct depend, dep) + len)) == NULL)
return (NULL);
memset(&d->dep, 0, len);
d->dep.obj = *obj;
if (idx == NULL)
d->dep.idx.len = 0;
else
d->dep.idx = *idx;
d->len = len;
d->func = func;
TAILQ_INSERT_TAIL(&context->dlist, d, link);
return (&d->dep);
}
/*
* Register a finish function.
*/
int
snmp_set_atfinish(struct snmp_context *ctx, snmp_set_finish_t func, void *arg)
{
struct context *context;
struct finish *f;
context = (struct context *)(void *)
((char *)ctx - offsetof(struct context, ctx));
if ((f = malloc(sizeof(struct finish))) == NULL)
return (-1);
f->func = func;
f->arg = arg;
STAILQ_INSERT_TAIL(&context->flist, f, link);
return (0);
}
/*
* Make an error response from a PDU. We do this without decoding the
* variable bindings. This means we can sent the junk back to a caller
* that has sent us junk in the first place.
*/
enum snmp_ret
snmp_make_errresp(const struct snmp_pdu *pdu, struct asn_buf *pdu_b,
struct asn_buf *resp_b)
{
asn_len_t len;
struct snmp_pdu resp;
enum asn_err err;
enum snmp_code code;
memset(&resp, 0, sizeof(resp));
/* Message sequence */
if (asn_get_sequence(pdu_b, &len) != ASN_ERR_OK)
return (SNMP_RET_IGN);
if (pdu_b->asn_len < len)
return (SNMP_RET_IGN);
err = snmp_parse_message_hdr(pdu_b, &resp, &len);
if (ASN_ERR_STOPPED(err))
return (SNMP_RET_IGN);
if (pdu_b->asn_len < len)
return (SNMP_RET_IGN);
pdu_b->asn_len = len;
err = snmp_parse_pdus_hdr(pdu_b, &resp, &len);
if (ASN_ERR_STOPPED(err))
return (SNMP_RET_IGN);
if (pdu_b->asn_len < len)
return (SNMP_RET_IGN);
pdu_b->asn_len = len;
/* now we have the bindings left - construct new message */
resp.error_status = pdu->error_status;
resp.error_index = pdu->error_index;
resp.type = SNMP_PDU_RESPONSE;
code = snmp_pdu_encode_header(resp_b, &resp);
if (code != SNMP_CODE_OK)
return (SNMP_RET_IGN);
if (pdu_b->asn_len > resp_b->asn_len)
/* too short */
return (SNMP_RET_IGN);
(void)memcpy(resp_b->asn_ptr, pdu_b->asn_cptr, pdu_b->asn_len);
resp_b->asn_len -= pdu_b->asn_len;
resp_b->asn_ptr += pdu_b->asn_len;
code = snmp_fix_encoding(resp_b, &resp);
if (code != SNMP_CODE_OK)
return (SNMP_RET_IGN);
return (SNMP_RET_OK);
}
static void
snmp_debug_func(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
fprintf(stderr, "\n");
}
|