packet-snmp.c

   1 /* packet-snmp.c
   2  * Routines for SNMP (simple network management protocol)
   3  * Copyright (C) 1998 Didier Jorand
   4  *
   5  * See RFC 1157 for SNMPv1.
   6  *
   7  * See RFCs 1901, 1905, and 1906 for SNMPv2c.
   8  *
   9  * See RFCs 1905, 1906, 1909, and 1910 for SNMPv2u.
  10  *
  11  * $Id: packet-snmp.c,v 1.91 2002/04/01 21:59:59 guy Exp $
  12  *
  13  * Ethereal - Network traffic analyzer
  14  * By Gerald Combs <gerald@ethereal.com>
  15  * Copyright 1998 Gerald Combs
  16  *
  17  * Some stuff from:
  18  *
  19  * GXSNMP -- An snmp mangament application
  20  * Copyright (C) 1998 Gregory McLean & Jochen Friedrich
  21  * Beholder RMON ethernet network monitor,Copyright (C) 1993 DNPAP group
  22  *
  23  * This program is free software; you can redistribute it and/or
  24  * modify it under the terms of the GNU General Public License
  25  * as published by the Free Software Foundation; either version 2
  26  * of the License, or (at your option) any later version.
  27  *
  28  * This program is distributed in the hope that it will be useful,
  29  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  30  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  31  * GNU General Public License for more details.
  32  *
  33  * You should have received a copy of the GNU General Public License
  34  * along with this program; if not, write to the Free Software
  35  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  36  */
  37
  38 #ifdef HAVE_CONFIG_H
  39 # include "config.h"
  40 #endif
  41
  42 #include <stdio.h>
  43 #include <string.h>
  44 #include <ctype.h>
  45
  46 #ifdef HAVE_SYS_TYPES_H
  47 # include <sys/types.h>
  48 #endif
  49
  50 #ifdef HAVE_NETINET_IN_H
  51 # include <netinet/in.h>
  52 #endif
  53
  54 #include <glib.h>
  55
  56 #include <epan/packet.h>
  57 #include <epan/strutil.h>
  58 #include <epan/conversation.h>
  59 #include "etypes.h"
  60 #include "packet-ipx.h"
  61
  62 #ifdef HAVE_UCD_SNMP
  63 # include <ucd-snmp/ucd-snmp-config.h>
  64 # include <ucd-snmp/asn1.h>
  65 # include <ucd-snmp/snmp_api.h>
  66 # include <ucd-snmp/snmp_impl.h>
  67 # include <ucd-snmp/mib.h>
  68 # include <ucd-snmp/default_store.h>
  69 # include <ucd-snmp/read_config.h>
  70 # include <ucd-snmp/tools.h>
  71
  72    /*
  73     * Define values "sprint_realloc_value()" expects.
  74     */
  75 # define VALTYPE_INTEGER        ASN_INTEGER
  76 # define VALTYPE_COUNTER        ASN_COUNTER
  77 # define VALTYPE_GAUGE          ASN_GAUGE
  78 # define VALTYPE_TIMETICKS      ASN_TIMETICKS
  79 # define VALTYPE_STRING         ASN_OCTET_STR
  80 # define VALTYPE_IPADDR         ASN_IPADDRESS
  81 # define VALTYPE_OPAQUE         ASN_OPAQUE
  82 # define VALTYPE_NSAP           ASN_NSAP
  83 # define VALTYPE_OBJECTID       ASN_OBJECT_ID
  84 # define VALTYPE_BITSTR         ASN_BIT_STR
  85 # define VALTYPE_COUNTER64      ASN_COUNTER64
  86
  87 #endif
  88
  89 #include "asn1.h"
  90
  91 #include "packet-snmp.h"
  92 #include "format-oid.h"
  93
  94 /* Null string of type "guchar[]". */
  95 static const guchar nullstring[] = "";
  96
  97 /* Take a pointer that may be null and return a pointer that's not null
  98    by turning null pointers into pointers to the above null string. */
  99 #define SAFE_STRING(s)  (((s) != NULL) ? (s) : nullstring)
 100
 101 static int proto_snmp = -1;
 102 static int proto_smux = -1;
 103
 104 static gint ett_snmp = -1;
 105 static gint ett_smux = -1;
 106 static gint ett_parameters = -1;
 107 static gint ett_parameters_qos = -1;
 108 static gint ett_global = -1;
 109 static gint ett_flags = -1;
 110 static gint ett_secur = -1;
 111
 112 static int hf_snmpv3_flags = -1;
 113 static int hf_snmpv3_flags_auth = -1;
 114 static int hf_snmpv3_flags_crypt = -1;
 115 static int hf_snmpv3_flags_report = -1;
 116
 117 static dissector_handle_t snmp_handle;
 118 static dissector_handle_t data_handle;
 119
 120 #define TH_AUTH   0x01
 121 #define TH_CRYPT  0x02
 122 #define TH_REPORT 0x04
 123
 124 static const true_false_string flags_set_truth = {
 125   "Set",
 126   "Not set"
 127 };
 128
 129 #define UDP_PORT_SNMP           161
 130 #define UDP_PORT_SNMP_TRAP      162
 131 #define TCP_PORT_SMUX           199
 132
 133 /* Protocol version numbers */
 134 #define SNMP_VERSION_1  0
 135 #define SNMP_VERSION_2c 1
 136 #define SNMP_VERSION_2u 2
 137 #define SNMP_VERSION_3  3
 138
 139 static const value_string versions[] = {
 140         { SNMP_VERSION_1,       "1" },
 141         { SNMP_VERSION_2c,      "2C" },
 142         { SNMP_VERSION_2u,      "2U" },
 143         { SNMP_VERSION_3,       "3" },
 144         { 0,                    NULL },
 145 };
 146
 147 /* PDU types */
 148 #define SNMP_MSG_GET            0
 149 #define SNMP_MSG_GETNEXT        1
 150 #define SNMP_MSG_RESPONSE       2
 151 #define SNMP_MSG_SET            3
 152 #define SNMP_MSG_TRAP           4
 153
 154 #define SNMP_MSG_GETBULK        5
 155 #define SNMP_MSG_INFORM         6
 156 #define SNMP_MSG_TRAP2          7
 157 #define SNMP_MSG_REPORT         8
 158
 159 static const value_string pdu_types[] = {
 160         { SNMP_MSG_GET,         "GET" },
 161         { SNMP_MSG_GETNEXT,     "GET-NEXT" },
 162         { SNMP_MSG_SET,         "SET" },
 163         { SNMP_MSG_RESPONSE,    "RESPONSE" },
 164         { SNMP_MSG_TRAP,        "TRAP-V1" },
 165         { SNMP_MSG_GETBULK,     "GETBULK" },
 166         { SNMP_MSG_INFORM,      "INFORM" },
 167         { SNMP_MSG_TRAP2,       "TRAP-V2" },
 168         { SNMP_MSG_REPORT,      "REPORT" },
 169         { 0,                    NULL }
 170 };
 171
 172 /* SMUX PDU types */
 173 #define SMUX_MSG_OPEN           0
 174 #define SMUX_MSG_CLOSE          1
 175 #define SMUX_MSG_RREQ           2
 176 #define SMUX_MSG_RRSP           3
 177 #define SMUX_MSG_SOUT           4
 178
 179 static const value_string smux_types[] = {
 180         { SMUX_MSG_OPEN,        "Open" },
 181         { SMUX_MSG_CLOSE,       "Close" },
 182         { SMUX_MSG_RREQ,        "Registration Request" },
 183         { SMUX_MSG_RRSP,        "Registration Response" },
 184         { SMUX_MSG_SOUT,        "Commit Or Rollback" },
 185         { 0,                    NULL }
 186 };
 187
 188 /* SMUX Closing causes */
 189 #define SMUX_CLOSE_DOWN                 0
 190 #define SMUX_CLOSE_VERSION              1
 191 #define SMUX_CLOSE_PACKET               2
 192 #define SMUX_CLOSE_PROTOCOL             3
 193 #define SMUX_CLOSE_INTERNAL             4
 194 #define SMUX_CLOSE_NOAUTH               5
 195
 196 static const value_string smux_close[] = {
 197         { SMUX_CLOSE_DOWN,      "Going down" },
 198         { SMUX_CLOSE_VERSION,   "Unsupported Version" },
 199         { SMUX_CLOSE_PACKET,    "Packet Format Error" },
 200         { SMUX_CLOSE_PROTOCOL,  "Protocol Error" },
 201         { SMUX_CLOSE_INTERNAL,  "Internal Error" },
 202         { SMUX_CLOSE_NOAUTH,    "Unauthorized" },
 203         { 0,                    NULL }
 204 };
 205
 206 /* SMUX Request codes */
 207 #define SMUX_RREQ_DELETE                0
 208 #define SMUX_RREQ_READONLY              1
 209 #define SMUX_RREQ_READWRITE             2
 210
 211 static const value_string smux_rreq[] = {
 212         { SMUX_RREQ_DELETE,     "Delete" },
 213         { SMUX_RREQ_READONLY,   "Read Only" },
 214         { SMUX_RREQ_READWRITE,  "Read Write" },
 215         { 0,                    NULL }
 216 };
 217
 218 static const value_string smux_prio[] = {
 219         { -1,                           "Failure" },
 220         { 0,                            NULL }
 221 };
 222
 223 /* SMUX SOut codes */
 224 #define SMUX_SOUT_COMMIT                0
 225 #define SMUX_SOUT_ROLLBACK              1
 226
 227 static const value_string smux_sout[] = {
 228         { SMUX_SOUT_COMMIT,             "Commit" },
 229         { SMUX_SOUT_ROLLBACK,           "Rollback" },
 230         { 0,                            NULL }
 231 };
 232
 233 /* Error status values */
 234 #define SNMP_ERR_NOERROR                0
 235 #define SNMP_ERR_TOOBIG                 1
 236 #define SNMP_ERR_NOSUCHNAME             2
 237 #define SNMP_ERR_BADVALUE               3
 238 #define SNMP_ERR_READONLY               4
 239 #define SNMP_ERR_GENERROR               5
 240
 241 #define SNMP_ERR_NOACCESS               6
 242 #define SNMP_ERR_WRONGTYPE              7
 243 #define SNMP_ERR_WRONGLENGTH            8
 244 #define SNMP_ERR_WRONGENCODING          9
 245 #define SNMP_ERR_WRONGVALUE             10
 246 #define SNMP_ERR_NOCREATION             11
 247 #define SNMP_ERR_INCONSISTENTVALUE      12
 248 #define SNMP_ERR_RESOURCEUNAVAILABLE    13
 249 #define SNMP_ERR_COMMITFAILED           14
 250 #define SNMP_ERR_UNDOFAILED             15
 251 #define SNMP_ERR_AUTHORIZATIONERROR     16
 252 #define SNMP_ERR_NOTWRITABLE            17
 253 #define SNMP_ERR_INCONSISTENTNAME       18
 254
 255 static const value_string error_statuses[] = {
 256         { SNMP_ERR_NOERROR,             "NO ERROR" },
 257         { SNMP_ERR_TOOBIG,              "TOOBIG" },
 258         { SNMP_ERR_NOSUCHNAME,          "NO SUCH NAME" },
 259         { SNMP_ERR_BADVALUE,            "BAD VALUE" },
 260         { SNMP_ERR_READONLY,            "READ ONLY" },
 261         { SNMP_ERR_GENERROR,            "GENERIC ERROR" },
 262         { SNMP_ERR_NOACCESS,            "NO ACCESS" },
 263         { SNMP_ERR_WRONGTYPE,           "WRONG TYPE" },
 264         { SNMP_ERR_WRONGLENGTH,         "WRONG LENGTH" },
 265         { SNMP_ERR_WRONGENCODING,       "WRONG ENCODING" },
 266         { SNMP_ERR_WRONGVALUE,          "WRONG VALUE" },
 267         { SNMP_ERR_NOCREATION,          "NO CREATION" },
 268         { SNMP_ERR_INCONSISTENTVALUE,   "INCONSISTENT VALUE" },
 269         { SNMP_ERR_RESOURCEUNAVAILABLE, "RESOURCE UNAVAILABLE" },
 270         { SNMP_ERR_COMMITFAILED,        "COMMIT FAILED" },
 271         { SNMP_ERR_UNDOFAILED,          "UNDO FAILED" },
 272         { SNMP_ERR_AUTHORIZATIONERROR,  "AUTHORIZATION ERROR" },
 273         { SNMP_ERR_NOTWRITABLE,         "NOT WRITABLE" },
 274         { SNMP_ERR_INCONSISTENTNAME,    "INCONSISTENT NAME" },
 275         { 0,                            NULL }
 276 };
 277
 278 /* General SNMP V1 Traps */
 279
 280 #define SNMP_TRAP_COLDSTART             0
 281 #define SNMP_TRAP_WARMSTART             1
 282 #define SNMP_TRAP_LINKDOWN              2
 283 #define SNMP_TRAP_LINKUP                3
 284 #define SNMP_TRAP_AUTHFAIL              4
 285 #define SNMP_TRAP_EGPNEIGHBORLOSS       5
 286 #define SNMP_TRAP_ENTERPRISESPECIFIC    6
 287
 288 static const value_string trap_types[] = {
 289         { SNMP_TRAP_COLDSTART,          "COLD START" },
 290         { SNMP_TRAP_WARMSTART,          "WARM START" },
 291         { SNMP_TRAP_LINKDOWN,           "LINK DOWN" },
 292         { SNMP_TRAP_LINKUP,             "LINK UP" },
 293         { SNMP_TRAP_AUTHFAIL,           "AUTHENTICATION FAILED" },
 294         { SNMP_TRAP_EGPNEIGHBORLOSS,    "EGP NEIGHBORLOSS" },
 295         { SNMP_TRAP_ENTERPRISESPECIFIC, "ENTERPRISE SPECIFIC" },
 296         { 0,                            NULL }
 297 };
 298
 299 /* Security Models */
 300
 301 #define SNMP_SEC_ANY                    0
 302 #define SNMP_SEC_V1                     1
 303 #define SNMP_SEC_V2C                    2
 304 #define SNMP_SEC_USM                    3
 305
 306 static const value_string sec_models[] = {
 307         { SNMP_SEC_ANY,                 "Any" },
 308         { SNMP_SEC_V1,                  "V1" },
 309         { SNMP_SEC_V2C,                 "V2C" },
 310         { SNMP_SEC_USM,                 "USM" },
 311         { 0,                            NULL }
 312 };
 313
 314 /* SNMP Tags */
 315
 316 #define SNMP_IPA    0           /* IP Address */
 317 #define SNMP_CNT    1           /* Counter (Counter32) */
 318 #define SNMP_GGE    2           /* Gauge (Gauge32) */
 319 #define SNMP_TIT    3           /* TimeTicks */
 320 #define SNMP_OPQ    4           /* Opaque */
 321 #define SNMP_NSP    5           /* NsapAddress */
 322 #define SNMP_C64    6           /* Counter64 */
 323 #define SNMP_U32    7           /* Uinteger32 */
 324
 325 #define SERR_NSO    0
 326 #define SERR_NSI    1
 327 #define SERR_EOM    2
 328
 329 /* SNMPv1 Types */
 330
 331 #define SNMP_NULL                0
 332 #define SNMP_INTEGER             1    /* l  */
 333 #define SNMP_OCTETSTR            2    /* c  */
 334 #define SNMP_DISPLAYSTR          2    /* c  */
 335 #define SNMP_OBJECTID            3    /* ul */
 336 #define SNMP_IPADDR              4    /* uc */
 337 #define SNMP_COUNTER             5    /* ul */
 338 #define SNMP_GAUGE               6    /* ul */
 339 #define SNMP_TIMETICKS           7    /* ul */
 340 #define SNMP_OPAQUE              8    /* c  */
 341
 342 /* additional SNMPv2 Types */
 343
 344 #define SNMP_UINTEGER            5    /* ul */
 345 #define SNMP_BITSTR              9    /* uc */
 346 #define SNMP_NSAP               10    /* uc */
 347 #define SNMP_COUNTER64          11    /* ul */
 348 #define SNMP_NOSUCHOBJECT       12
 349 #define SNMP_NOSUCHINSTANCE     13
 350 #define SNMP_ENDOFMIBVIEW       14
 351
 352 typedef struct _SNMP_CNV SNMP_CNV;
 353
 354 struct _SNMP_CNV
 355 {
 356   guint class;
 357   guint tag;
 358   gint  syntax;
 359   gchar *name;
 360 };
 361
 362 static SNMP_CNV SnmpCnv [] =
 363 {
 364   {ASN1_UNI, ASN1_NUL, SNMP_NULL,      "NULL"},
 365   {ASN1_UNI, ASN1_INT, SNMP_INTEGER,   "INTEGER"},
 366   {ASN1_UNI, ASN1_OTS, SNMP_OCTETSTR,  "OCTET STRING"},
 367   {ASN1_UNI, ASN1_OJI, SNMP_OBJECTID,  "OBJECTID"},
 368   {ASN1_APL, SNMP_IPA, SNMP_IPADDR,    "IPADDR"},
 369   {ASN1_APL, SNMP_CNT, SNMP_COUNTER,   "COUNTER"},  /* Counter32 */
 370   {ASN1_APL, SNMP_GGE, SNMP_GAUGE,     "GAUGE"},    /* Gauge32 == Unsigned32  */
 371   {ASN1_APL, SNMP_TIT, SNMP_TIMETICKS, "TIMETICKS"},
 372   {ASN1_APL, SNMP_OPQ, SNMP_OPAQUE,    "OPAQUE"},
 373
 374 /* SNMPv2 data types and errors */
 375
 376   {ASN1_UNI, ASN1_BTS, SNMP_BITSTR,         "BITSTR"},
 377   {ASN1_APL, SNMP_C64, SNMP_COUNTER64,      "COUNTER64"},
 378   {ASN1_CTX, SERR_NSO, SNMP_NOSUCHOBJECT,   "NOSUCHOBJECT"},
 379   {ASN1_CTX, SERR_NSI, SNMP_NOSUCHINSTANCE, "NOSUCHINSTANCE"},
 380   {ASN1_CTX, SERR_EOM, SNMP_ENDOFMIBVIEW,   "ENDOFMIBVIEW"},
 381   {0,       0,         -1,                  NULL}
 382 };
 383
 384 /*
 385  * NAME:        g_snmp_tag_cls2syntax
 386  * SYNOPSIS:    gboolean g_snmp_tag_cls2syntax
 387  *                  (
 388  *                      guint    tag,
 389  *                      guint    cls,
 390  *                      gushort *syntax
 391  *                  )
 392  * DESCRIPTION: Converts ASN1 tag and class to Syntax tag and name.
 393  *              See SnmpCnv for conversion.
 394  * RETURNS:     name on success, NULL on failure
 395  */
 396
 397 static gchar *
 398 snmp_tag_cls2syntax ( guint tag, guint cls, gushort *syntax)
 399 {
 400     SNMP_CNV *cnv;
 401
 402     cnv = SnmpCnv;
 403     while (cnv->syntax != -1)
 404     {
 405         if (cnv->tag == tag && cnv->class == cls)
 406         {
 407             *syntax = cnv->syntax;
 408             return cnv->name;
 409         }
 410         cnv++;
 411     }
 412     return NULL;
 413 }
 414
 415 static void
 416 dissect_snmp_parse_error(tvbuff_t *tvb, int offset, packet_info *pinfo,
 417                    proto_tree *tree, const char *field_name, int ret)
 418 {
 419         char *errstr;
 420
 421         errstr = asn1_err_to_str(ret);
 422
 423         if (check_col(pinfo->cinfo, COL_INFO)) {
 424                 col_add_fstr(pinfo->cinfo, COL_INFO,
 425                     "ERROR: Couldn't parse %s: %s", field_name, errstr);
 426         }
 427         if (tree != NULL) {
 428                 proto_tree_add_text(tree, tvb, offset, 0,
 429                     "ERROR: Couldn't parse %s: %s", field_name, errstr);
 430                 call_dissector(data_handle,
 431                     tvb_new_subset(tvb, offset, -1, -1), pinfo, tree);
 432         }
 433 }
 434
 435 static void
 436 dissect_snmp_error(tvbuff_t *tvb, int offset, packet_info *pinfo,
 437                    proto_tree *tree, const char *message)
 438 {
 439         if (check_col(pinfo->cinfo, COL_INFO))
 440                 col_add_str(pinfo->cinfo, COL_INFO, message);
 441
 442         if (tree != NULL) {
 443                 proto_tree_add_text(tree, tvb, offset, 0, "%s", message);
 444                 call_dissector(data_handle,tvb_new_subset(tvb, offset,-1,tvb_reported_length_remaining(tvb,offset)), pinfo, tree);
 445         }
 446 }
 447
 448 gchar *
 449 format_oid(subid_t *oid, guint oid_length)
 450 {
 451         char *result;
 452         int result_len;
 453         int len;
 454         unsigned int i;
 455         char *buf;
 456 #ifdef HAVE_UCD_SNMP
 457         u_char *oid_string;
 458         size_t oid_string_len;
 459         size_t oid_out_len;
 460 #endif
 461
 462         result_len = oid_length * 22;
 463
 464 #ifdef HAVE_UCD_SNMP
 465         /*
 466          * Get the decoded form of the OID, and add its length to the
 467          * length of the result string.
 468          *
 469          * XXX - check for "malloc" and "sprint_realloc_objid()" failure.
 470          */
 471         oid_string_len = 256;
 472         oid_string = malloc(oid_string_len);
 473         *oid_string = '\0';
 474         oid_out_len = 0;
 475         sprint_realloc_objid(&oid_string, &oid_string_len, &oid_out_len, 1,
 476             oid, oid_length);
 477         result_len += strlen(oid_string) + 3;
 478 #endif
 479
 480         result = g_malloc(result_len + 1);
 481         buf = result;
 482         len = sprintf(buf, "%lu", (unsigned long)oid[0]);
 483         buf += len;
 484         for (i = 1; i < oid_length;i++) {
 485                 len = sprintf(buf, ".%lu", (unsigned long)oid[i]);
 486                 buf += len;
 487         }
 488
 489 #ifdef HAVE_UCD_SNMP
 490         /*
 491          * Append the decoded form of the OID.
 492          */
 493         sprintf(buf, " (%s)", oid_string);
 494         free(oid_string);
 495 #endif
 496
 497         return result;
 498 }
 499
 500 #ifdef HAVE_UCD_SNMP
 501 static u_char *
 502 check_var_length(guint vb_length, guint required_length)
 503 {
 504         u_char *buf;
 505         static const char badlen_fmt[] = "Length is %u, should be %u";
 506
 507         if (vb_length != required_length) {
 508                 /* Enough room for the largest "Length is XXX,
 509                    should be XXX" message - 10 digits for each
 510                    XXX. */
 511                 buf = malloc(sizeof badlen_fmt + 10 + 10);
 512                 sprintf(buf, badlen_fmt, vb_length, required_length);
 513                 return buf;
 514         }
 515         return NULL;    /* length is OK */
 516 }
 517
 518 static u_char *
 519 format_var(struct variable_list *variable, subid_t *variable_oid,
 520     guint variable_oid_length, gushort vb_type, guint val_len)
 521 {
 522         u_char *buf;
 523         size_t buf_len;
 524         size_t out_len;
 525
 526         switch (vb_type) {
 527
 528         case SNMP_IPADDR:
 529                 /* Length has to be 4 bytes. */
 530                 buf = check_var_length(val_len, 4);
 531                 if (buf != NULL)
 532                         return buf;     /* it's not 4 bytes */
 533                 break;
 534
 535         case SNMP_COUNTER64:
 536                 /* Length has to be 8 bytes. */
 537                 buf = check_var_length(val_len, 8);
 538                 if (buf != NULL)
 539                         return buf;     /* it's not 8 bytes */
 540                 break;
 541
 542         default:
 543                 break;
 544         }
 545
 546         variable->next_variable = NULL;
 547         variable->name = variable_oid;
 548         variable->name_length = variable_oid_length;
 549         switch (vb_type) {
 550
 551         case SNMP_INTEGER:
 552                 variable->type = VALTYPE_INTEGER;
 553                 break;
 554
 555         case SNMP_COUNTER:
 556                 variable->type = VALTYPE_COUNTER;
 557                 break;
 558
 559         case SNMP_GAUGE:
 560                 variable->type = VALTYPE_GAUGE;
 561                 break;
 562
 563         case SNMP_TIMETICKS:
 564                 variable->type = VALTYPE_TIMETICKS;
 565                 break;
 566
 567         case SNMP_OCTETSTR:
 568                 variable->type = VALTYPE_STRING;
 569                 break;
 570
 571         case SNMP_IPADDR:
 572                 variable->type = VALTYPE_IPADDR;
 573                 break;
 574
 575         case SNMP_OPAQUE:
 576                 variable->type = VALTYPE_OPAQUE;
 577                 break;
 578
 579         case SNMP_NSAP:
 580                 variable->type = VALTYPE_NSAP;
 581                 break;
 582
 583         case SNMP_OBJECTID:
 584                 variable->type = VALTYPE_OBJECTID;
 585                 break;
 586
 587         case SNMP_BITSTR:
 588                 variable->type = VALTYPE_BITSTR;
 589                 break;
 590
 591         case SNMP_COUNTER64:
 592                 variable->type = VALTYPE_COUNTER64;
 593                 break;
 594         }
 595         variable->val_len = val_len;
 596
 597         /*
 598          * XXX - check for "malloc" and "sprint_realloc_objid()" failure.
 599          */
 600         buf_len = 256;
 601         buf = malloc(buf_len);
 602         *buf = '\0';
 603         out_len = 0;
 604         sprint_realloc_value(&buf, &buf_len, &out_len, 1,  variable_oid,
 605             variable_oid_length, variable);
 606         return buf;
 607 }
 608 #endif
 609
 610 static int
 611 snmp_variable_decode(proto_tree *snmp_tree,
 612     subid_t *variable_oid
 613 #ifndef HAVE_UCD_SNMP
 614         _U_
 615 #endif
 616     ,
 617     guint variable_oid_length
 618 #ifndef HAVE_UCD_SNMP
 619         _U_
 620 #endif
 621     ,
 622     ASN1_SCK *asn1, int offset, guint *lengthp)
 623 {
 624         int start;
 625         guint length;
 626         gboolean def;
 627         guint vb_length;
 628         gushort vb_type;
 629         gchar *vb_type_name;
 630         int ret;
 631         guint cls, con, tag;
 632
 633         gint32 vb_integer_value;
 634         guint32 vb_uinteger_value;
 635
 636         guint8 *vb_octet_string;
 637
 638         subid_t *vb_oid;
 639         guint vb_oid_length;
 640
 641         gchar *vb_display_string;
 642
 643 #ifdef HAVE_UCD_SNMP
 644         struct variable_list variable;
 645         long value;
 646 #endif  /* HAVE_UCD_SNMP */
 647         unsigned int i;
 648         gchar *buf;
 649         int len;
 650
 651         /* parse the type of the object */
 652         start = asn1->offset;
 653         ret = asn1_header_decode (asn1, &cls, &con, &tag, &def, &vb_length);
 654         if (ret != ASN1_ERR_NOERROR)
 655                 return ret;
 656         if (!def)
 657                 return ASN1_ERR_LENGTH_NOT_DEFINITE;
 658
 659         /* Convert the class, constructed flag, and tag to a type. */
 660         vb_type_name = snmp_tag_cls2syntax(tag, cls, &vb_type);
 661         if (vb_type_name == NULL) {
 662                 /*
 663                  * Unsupported type.
 664                  * Dissect the value as an opaque string of octets.
 665                  */
 666                 vb_type_name = "unsupported type";
 667                 vb_type = SNMP_OPAQUE;
 668         }
 669
 670         /* parse the value */
 671         switch (vb_type) {
 672
 673         case SNMP_INTEGER:
 674                 ret = asn1_int32_value_decode(asn1, vb_length,
 675                     &vb_integer_value);
 676                 if (ret != ASN1_ERR_NOERROR)
 677                         return ret;
 678                 length = asn1->offset - start;
 679                 if (snmp_tree) {
 680 #ifdef HAVE_UCD_SNMP
 681                         value = vb_integer_value;
 682                         variable.val.integer = &value;
 683                         vb_display_string = format_var(&variable,
 684                             variable_oid, variable_oid_length, vb_type,
 685                             vb_length);
 686                         proto_tree_add_text(snmp_tree, asn1->tvb, offset,
 687                             length,
 688                             "Value: %s", vb_display_string);
 689                         free(vb_display_string);
 690 #else /* HAVE_UCD_SNMP */
 691                         proto_tree_add_text(snmp_tree, asn1->tvb, offset,
 692                             length,
 693                             "Value: %s: %d (%#x)", vb_type_name,
 694                             vb_integer_value, vb_integer_value);
 695 #endif /* HAVE_UCD_SNMP */
 696                 }
 697                 break;
 698
 699         case SNMP_COUNTER:
 700         case SNMP_GAUGE:
 701         case SNMP_TIMETICKS:
 702                 ret = asn1_uint32_value_decode(asn1, vb_length,
 703                     &vb_uinteger_value);
 704                 if (ret != ASN1_ERR_NOERROR)
 705                         return ret;
 706                 length = asn1->offset - start;
 707                 if (snmp_tree) {
 708 #ifdef HAVE_UCD_SNMP
 709                         value = vb_uinteger_value;
 710                         variable.val.integer = &value;
 711                         vb_display_string = format_var(&variable,
 712                             variable_oid, variable_oid_length, vb_type,
 713                             vb_length);
 714                         proto_tree_add_text(snmp_tree, asn1->tvb, offset,
 715                             length,
 716                             "Value: %s", vb_display_string);
 717                         free(vb_display_string);
 718 #else /* HAVE_UCD_SNMP */
 719                         proto_tree_add_text(snmp_tree, asn1->tvb, offset,
 720                             length,
 721                             "Value: %s: %u (%#x)", vb_type_name,
 722                             vb_uinteger_value, vb_uinteger_value);
 723 #endif /* HAVE_UCD_SNMP */
 724                 }
 725                 break;
 726
 727         case SNMP_OCTETSTR:
 728         case SNMP_IPADDR:
 729         case SNMP_OPAQUE:
 730         case SNMP_NSAP:
 731         case SNMP_BITSTR:
 732         case SNMP_COUNTER64:
 733                 ret = asn1_string_value_decode (asn1, vb_length,
 734                     &vb_octet_string);
 735                 if (ret != ASN1_ERR_NOERROR)
 736                         return ret;
 737                 length = asn1->offset - start;
 738                 if (snmp_tree) {
 739 #ifdef HAVE_UCD_SNMP
 740                         variable.val.string = vb_octet_string;
 741                         vb_display_string = format_var(&variable,
 742                             variable_oid, variable_oid_length, vb_type,
 743                             vb_length);
 744                         proto_tree_add_text(snmp_tree, asn1->tvb, offset,
 745                             length,
 746                             "Value: %s", vb_display_string);
 747                         free(vb_display_string);
 748 #else /* HAVE_UCD_SNMP */
 749                         /*
 750                          * If some characters are not printable, display
 751                          * the string as bytes.
 752                          */
 753                         for (i = 0; i < vb_length; i++) {
 754                                 if (!(isprint(vb_octet_string[i])
 755                                     || isspace(vb_octet_string[i])))
 756                                         break;
 757                         }
 758                         if (i < vb_length) {
 759                                 /*
 760                                  * We stopped, due to a non-printable
 761                                  * character, before we got to the end
 762                                  * of the string.
 763                                  */
 764                                 vb_display_string = g_malloc(4*vb_length);
 765                                 buf = &vb_display_string[0];
 766                                 len = sprintf(buf, "%03u", vb_octet_string[0]);
 767                                 buf += len;
 768                                 for (i = 1; i < vb_length; i++) {
 769                                         len = sprintf(buf, ".%03u",
 770                                             vb_octet_string[i]);
 771                                         buf += len;
 772                                 }
 773                                 proto_tree_add_text(snmp_tree, asn1->tvb, offset,
 774                                     length,
 775                                     "Value: %s: %s", vb_type_name,
 776                                     vb_display_string);
 777                                 g_free(vb_display_string);
 778                         } else {
 779                                 proto_tree_add_text(snmp_tree, asn1->tvb, offset,
 780                                     length,
 781                                     "Value: %s: %.*s", vb_type_name,
 782                                     (int)vb_length,
 783                                     SAFE_STRING(vb_octet_string));
 784                         }
 785 #endif /* HAVE_UCD_SNMP */
 786                 }
 787                 g_free(vb_octet_string);
 788                 break;
 789
 790         case SNMP_NULL:
 791                 ret = asn1_null_decode (asn1, vb_length);
 792                 if (ret != ASN1_ERR_NOERROR)
 793                         return ret;
 794                 length = asn1->offset - start;
 795                 if (snmp_tree) {
 796                         proto_tree_add_text(snmp_tree, asn1->tvb, offset, length,
 797                             "Value: %s", vb_type_name);
 798                 }
 799                 break;
 800
 801         case SNMP_OBJECTID:
 802                 ret = asn1_oid_value_decode (asn1, vb_length, &vb_oid,
 803                     &vb_oid_length);
 804                 if (ret != ASN1_ERR_NOERROR)
 805                         return ret;
 806                 length = asn1->offset - start;
 807                 if (snmp_tree) {
 808 #ifdef HAVE_UCD_SNMP
 809                         variable.val.objid = vb_oid;
 810                         vb_display_string = format_var(&variable,
 811                             variable_oid, variable_oid_length, vb_type,
 812                             vb_oid_length * sizeof (subid_t));
 813                         proto_tree_add_text(snmp_tree, asn1->tvb, offset,
 814                             length,
 815                             "Value: %s", vb_display_string);
 816                         free(vb_display_string);
 817 #else /* HAVE_UCD_SNMP */
 818                         vb_display_string = format_oid(vb_oid, vb_oid_length);
 819                         proto_tree_add_text(snmp_tree, asn1->tvb, offset,
 820                             length,
 821                             "Value: %s: %s", vb_type_name, vb_display_string);
 822                         g_free(vb_display_string);
 823 #endif /* HAVE_UCD_SNMP */
 824                 }
 825                 g_free(vb_oid);
 826                 break;
 827
 828         case SNMP_NOSUCHOBJECT:
 829                 length = asn1->offset - start;
 830                 if (snmp_tree) {
 831                         proto_tree_add_text(snmp_tree, asn1->tvb, offset, length,
 832                             "Value: %s: no such object", vb_type_name);
 833                 }
 834                 break;
 835
 836         case SNMP_NOSUCHINSTANCE:
 837                 length = asn1->offset - start;
 838                 if (snmp_tree) {
 839                         proto_tree_add_text(snmp_tree, asn1->tvb, offset, length,
 840                             "Value: %s: no such instance", vb_type_name);
 841                 }
 842                 break;
 843
 844         case SNMP_ENDOFMIBVIEW:
 845                 length = asn1->offset - start;
 846                 if (snmp_tree) {
 847                         proto_tree_add_text(snmp_tree, asn1->tvb, offset, length,
 848                             "Value: %s: end of mib view", vb_type_name);
 849                 }
 850                 break;
 851
 852         default:
 853                 g_assert_not_reached();
 854                 return ASN1_ERR_WRONG_TYPE;
 855         }
 856         *lengthp = length;
 857         return ASN1_ERR_NOERROR;
 858 }
 859
 860 static void
 861 dissect_common_pdu(tvbuff_t *tvb, int offset, packet_info *pinfo,
 862     proto_tree *tree, ASN1_SCK asn1, guint pdu_type, int start)
 863 {
 864         gboolean def;
 865         guint length;
 866         guint sequence_length;
 867
 868         guint32 request_id;
 869
 870         guint32 error_status;
 871
 872         guint32 error_index;
 873
 874         char *pdu_type_string;
 875
 876         subid_t *enterprise;
 877         guint enterprise_length;
 878
 879         guint8 *agent_address;
 880         guint agent_address_length;
 881
 882         guint32 trap_type;
 883
 884         guint32 specific_type;
 885
 886         guint timestamp;
 887         guint timestamp_length;
 888
 889         gchar *oid_string;
 890
 891         guint variable_bindings_length;
 892
 893         int vb_index;
 894         guint variable_length;
 895         subid_t *variable_oid;
 896         guint variable_oid_length;
 897
 898         int ret;
 899         guint cls, con, tag;
 900
 901         pdu_type_string = val_to_str(pdu_type, pdu_types,
 902             "Unknown PDU type %#x");
 903         if (check_col(pinfo->cinfo, COL_INFO))
 904                 col_add_str(pinfo->cinfo, COL_INFO, pdu_type_string);
 905         length = asn1.offset - start;
 906         if (tree) {
 907                 proto_tree_add_text(tree, tvb, offset, length,
 908                     "PDU type: %s", pdu_type_string);
 909         }
 910         offset += length;
 911
 912         /* get the fields in the PDU preceeding the variable-bindings sequence */
 913         switch (pdu_type) {
 914
 915         case SNMP_MSG_GET:
 916         case SNMP_MSG_GETNEXT:
 917         case SNMP_MSG_RESPONSE:
 918         case SNMP_MSG_SET:
 919         case SNMP_MSG_GETBULK:
 920         case SNMP_MSG_INFORM:
 921         case SNMP_MSG_TRAP2:
 922         case SNMP_MSG_REPORT:
 923                 /* request id */
 924                 ret = asn1_uint32_decode (&asn1, &request_id, &length);
 925                 if (ret != ASN1_ERR_NOERROR) {
 926                         dissect_snmp_parse_error(tvb, offset, pinfo, tree,
 927                             "request ID", ret);
 928                         return;
 929                 }
 930                 if (tree) {
 931                         proto_tree_add_text(tree, tvb, offset, length,
 932                             "Request Id: %#x", request_id);
 933                 }
 934                 offset += length;
 935
 936                 /* error status, or getbulk non-repeaters */
 937                 ret = asn1_uint32_decode (&asn1, &error_status, &length);
 938                 if (ret != ASN1_ERR_NOERROR) {
 939                         dissect_snmp_parse_error(tvb, offset, pinfo, tree,
 940                             (pdu_type == SNMP_MSG_GETBULK) ? "non-repeaters"
 941                                                            : "error status",
 942                             ret);
 943                         return;
 944                 }
 945                 if (tree) {
 946                         if (pdu_type == SNMP_MSG_GETBULK) {
 947                                 proto_tree_add_text(tree, tvb, offset,
 948                                     length, "Non-repeaters: %u", error_status);
 949                         } else {
 950                                 proto_tree_add_text(tree, tvb, offset,
 951                                     length, "Error Status: %s",
 952                                     val_to_str(error_status, error_statuses,
 953                                       "Unknown (%d)"));
 954                         }
 955                 }
 956                 offset += length;
 957
 958                 /* error index, or getbulk max-repetitions */
 959                 ret = asn1_uint32_decode (&asn1, &error_index, &length);
 960                 if (ret != ASN1_ERR_NOERROR) {
 961                         dissect_snmp_parse_error(tvb, offset, pinfo, tree,
 962                             (pdu_type == SNMP_MSG_GETBULK) ? "max repetitions"
 963                                                            : "error index",
 964                             ret);
 965                         return;
 966                 }
 967                 if (tree) {
 968                         if (pdu_type == SNMP_MSG_GETBULK) {
 969                                 proto_tree_add_text(tree, tvb, offset,
 970                                     length, "Max repetitions: %u", error_index);
 971                         } else {
 972                                 proto_tree_add_text(tree, tvb, offset,
 973                                     length, "Error Index: %u", error_index);
 974                         }
 975                 }
 976                 offset += length;
 977                 break;
 978
 979         case SNMP_MSG_TRAP:
 980                 /* enterprise */
 981                 ret = asn1_oid_decode (&asn1, &enterprise, &enterprise_length,
 982                     &length);
 983                 if (ret != ASN1_ERR_NOERROR) {
 984                         dissect_snmp_parse_error(tvb, offset, pinfo, tree,
 985                             "enterprise OID", ret);
 986                         return;
 987                 }
 988                 if (tree) {
 989                         oid_string = format_oid(enterprise, enterprise_length);
 990                         proto_tree_add_text(tree, tvb, offset, length,
 991                             "Enterprise: %s", oid_string);
 992                         g_free(oid_string);
 993                 }
 994                 g_free(enterprise);
 995                 offset += length;
 996
 997                 /* agent address */
 998                 start = asn1.offset;
 999                 ret = asn1_header_decode (&asn1, &cls, &con, &tag,
1000                     &def, &agent_address_length);
1001                 if (ret != ASN1_ERR_NOERROR) {
1002                         dissect_snmp_parse_error(tvb, offset, pinfo, tree,
1003                             "agent address", ret);
1004                         return;
1005                 }
1006                 if (!((cls == ASN1_APL && con == ASN1_PRI && tag == SNMP_IPA) ||
1007                     (cls == ASN1_UNI && con == ASN1_PRI && tag == ASN1_OTS))) {
1008                         /* GXSNMP 0.0.15 says the latter is "needed for
1009                            Banyan" */
1010                         dissect_snmp_parse_error(tvb, offset, pinfo, tree,
1011                             "agent_address", ASN1_ERR_WRONG_TYPE);
1012                         return;
1013                 }
1014                 if (agent_address_length != 4) {
1015                         dissect_snmp_parse_error(tvb, offset, pinfo, tree,
1016                             "agent_address", ASN1_ERR_WRONG_LENGTH_FOR_TYPE);
1017                         return;
1018                 }
1019                 ret = asn1_string_value_decode (&asn1,
1020                     agent_address_length, &agent_address);
1021                 if (ret != ASN1_ERR_NOERROR) {
1022                         dissect_snmp_parse_error(tvb, offset, pinfo, tree,
1023                             "agent address", ret);
1024                         return;
1025                 }
1026                 length = asn1.offset - start;
1027                 if (tree) {
1028                         if (agent_address_length != 4) {
1029                                 proto_tree_add_text(tree, tvb, offset,
1030                                     length,
1031                                     "Agent address: <length is %u, not 4>",
1032                                     agent_address_length);
1033                         } else {
1034                                 proto_tree_add_text(tree, tvb, offset,
1035                                     length,
1036                                     "Agent address: %s",
1037                                     ip_to_str(agent_address));
1038                         }
1039                 }
1040                 g_free(agent_address);
1041                 offset += length;
1042
1043                 /* generic trap type */
1044                 ret = asn1_uint32_decode (&asn1, &trap_type, &length);
1045                 if (ret != ASN1_ERR_NOERROR) {
1046                         dissect_snmp_parse_error(tvb, offset, pinfo, tree,
1047                             "generic trap type", ret);
1048                         return;
1049                 }
1050                 if (tree) {
1051                         proto_tree_add_text(tree, tvb, offset, length,
1052                             "Trap type: %s",
1053                             val_to_str(trap_type, trap_types, "Unknown (%u)"));
1054                 }
1055                 offset += length;
1056
1057                 /* specific trap type */
1058                 ret = asn1_uint32_decode (&asn1, &specific_type, &length);
1059                 if (ret != ASN1_ERR_NOERROR) {
1060                         dissect_snmp_parse_error(tvb, offset, pinfo, tree,
1061                             "specific trap type", ret);
1062                         return;
1063                 }
1064                 if (tree) {
1065                         proto_tree_add_text(tree, tvb, offset, length,
1066                             "Specific trap type: %u (%#x)",
1067                             specific_type, specific_type);
1068                 }
1069                 offset += length;
1070
1071                 /* timestamp */
1072                 start = asn1.offset;
1073                 ret = asn1_header_decode (&asn1, &cls, &con, &tag,
1074                     &def, &timestamp_length);
1075                 if (ret != ASN1_ERR_NOERROR) {
1076                         dissect_snmp_parse_error(tvb, offset, pinfo, tree,
1077                             "timestamp", ret);
1078                         return;
1079                 }
1080                 if (!((cls == ASN1_APL && con == ASN1_PRI && tag == SNMP_TIT) ||
1081                     (cls == ASN1_UNI && con == ASN1_PRI && tag == ASN1_INT))) {
1082                         dissect_snmp_parse_error(tvb, offset, pinfo, tree,
1083                             "timestamp", ASN1_ERR_WRONG_TYPE);
1084                         return;
1085                 }
1086                 ret = asn1_uint32_value_decode(&asn1, timestamp_length,
1087                     &timestamp);
1088                 if (ret != ASN1_ERR_NOERROR) {
1089                         dissect_snmp_parse_error(tvb, offset, pinfo, tree,
1090                             "timestamp", ret);
1091                         return;
1092                 }
1093                 length = asn1.offset - start;
1094                 if (tree) {
1095                         proto_tree_add_text(tree, tvb, offset, length,
1096                             "Timestamp: %u", timestamp);
1097                 }
1098                 offset += length;
1099                 break;
1100         }
1101
1102         /* variable bindings */
1103         /* get header for variable-bindings sequence */
1104         ret = asn1_sequence_decode(&asn1, &variable_bindings_length, &length);
1105         if (ret != ASN1_ERR_NOERROR) {
1106                 dissect_snmp_parse_error(tvb, offset, pinfo, tree,
1107                         "variable bindings header", ret);
1108                 return;
1109         }
1110         offset += length;
1111
1112         /* loop on variable bindings */
1113         vb_index = 0;
1114         while (variable_bindings_length > 0) {
1115                 vb_index++;
1116                 sequence_length = 0;
1117
1118                 /* parse type */
1119                 ret = asn1_sequence_decode(&asn1, &variable_length, &length);
1120                 if (ret != ASN1_ERR_NOERROR) {
1121                         dissect_snmp_parse_error(tvb, offset, pinfo, tree,
1122                                 "variable binding header", ret);
1123                         return;
1124                 }
1125                 sequence_length += length;
1126
1127                 /* parse object identifier */
1128                 ret = asn1_oid_decode (&asn1, &variable_oid,
1129                     &variable_oid_length, &length);
1130                 if (ret != ASN1_ERR_NOERROR) {
1131                         dissect_snmp_parse_error(tvb, offset, pinfo, tree,
1132                             "variable binding OID", ret);
1133                         return;
1134                 }
1135                 sequence_length += length;
1136
1137                 if (tree) {
1138                         oid_string = format_oid(variable_oid,
1139                             variable_oid_length);
1140                         proto_tree_add_text(tree, tvb, offset, sequence_length,
1141                             "Object identifier %d: %s", vb_index, oid_string);
1142                         g_free(oid_string);
1143                 }
1144                 offset += sequence_length;
1145                 variable_bindings_length -= sequence_length;
1146
1147                 /* Parse the variable's value */
1148                 ret = snmp_variable_decode(tree, variable_oid,
1149                     variable_oid_length, &asn1, offset, &length);
1150                 if (ret != ASN1_ERR_NOERROR) {
1151                         dissect_snmp_parse_error(tvb, offset, pinfo, tree,
1152                             "variable", ret);
1153                         return;
1154                 }
1155                 offset += length;
1156                 variable_bindings_length -= length;
1157         }
1158 }
1159
1160 static const value_string qos_vals[] = {
1161         { 0x0,  "No authentication or privacy" },
1162         { 0x1,  "Authentication, no privacy" },
1163         { 0x2,  "Authentication and privacy" },
1164         { 0x3,  "Authentication and privacy" },
1165         { 0,    NULL },
1166 };
1167
1168 static void
1169 dissect_snmp2u_parameters(proto_tree *tree, tvbuff_t *tvb, int offset, int length,
1170     guchar *parameters, int parameters_length)
1171 {
1172         proto_item *item;
1173         proto_tree *parameters_tree;
1174         proto_tree *qos_tree;
1175         guint8 model;
1176         guint8 qos;
1177         guint8 len;
1178
1179         item = proto_tree_add_text(tree, tvb, offset, length,
1180             "Parameters");
1181         parameters_tree = proto_item_add_subtree(item, ett_parameters);
1182         offset += length - parameters_length;
1183
1184         if (parameters_length < 1)
1185                 return;
1186         model = *parameters;
1187         proto_tree_add_text(parameters_tree, tvb, offset, 1,
1188             "model: %u", model);
1189         offset += 1;
1190         parameters += 1;
1191         parameters_length -= 1;
1192         if (model != 1) {
1193                 /* Unknown model. */
1194                 proto_tree_add_text(parameters_tree, tvb, offset,
1195                     parameters_length, "parameters: %s",
1196                     bytes_to_str(parameters, parameters_length));
1197                 return;
1198         }
1199
1200         if (parameters_length < 1)
1201                 return;
1202         qos = *parameters;
1203         item = proto_tree_add_text(parameters_tree, tvb, offset, 1,
1204             "qoS: 0x%x", qos);
1205         qos_tree = proto_item_add_subtree(item, ett_parameters_qos);
1206         proto_tree_add_text(qos_tree, tvb, offset, 1, "%s",
1207             decode_boolean_bitfield(qos, 0x04,
1208                 8, "Generation of report PDU allowed",
1209                    "Generation of report PDU not allowed"));
1210         proto_tree_add_text(qos_tree, tvb, offset, 1, "%s",
1211             decode_enumerated_bitfield(qos, 0x03,
1212                 8, qos_vals, "%s"));
1213         offset += 1;
1214         parameters += 1;
1215         parameters_length -= 1;
1216
1217         if (parameters_length < 12)
1218                 return;
1219         proto_tree_add_text(parameters_tree, tvb, offset, 12,
1220             "agentID: %s", bytes_to_str(parameters, 12));
1221         offset += 12;
1222         parameters += 12;
1223         parameters_length -= 12;
1224
1225         if (parameters_length < 4)
1226                 return;
1227         proto_tree_add_text(parameters_tree, tvb, offset, 4,
1228             "agentBoots: %u", pntohl(parameters));
1229         offset += 4;
1230         parameters += 4;
1231         parameters_length -= 4;
1232
1233         if (parameters_length < 4)
1234                 return;
1235         proto_tree_add_text(parameters_tree, tvb, offset, 4,
1236             "agentTime: %u", pntohl(parameters));
1237         offset += 4;
1238         parameters += 4;
1239         parameters_length -= 4;
1240
1241         if (parameters_length < 2)
1242                 return;
1243         proto_tree_add_text(parameters_tree, tvb, offset, 2,
1244             "maxSize: %u", pntohs(parameters));
1245         offset += 2;
1246         parameters += 2;
1247         parameters_length -= 2;
1248
1249         if (parameters_length < 1)
1250                 return;
1251         len = *parameters;
1252         proto_tree_add_text(parameters_tree, tvb, offset, 1,
1253             "userLen: %u", len);
1254         offset += 1;
1255         parameters += 1;
1256         parameters_length -= 1;
1257
1258         if (parameters_length < len)
1259                 return;
1260         proto_tree_add_text(parameters_tree, tvb, offset, len,
1261             "userName: %.*s", len, parameters);
1262         offset += len;
1263         parameters += len;
1264         parameters_length -= len;
1265
1266         if (parameters_length < 1)
1267                 return;
1268         len = *parameters;
1269         proto_tree_add_text(parameters_tree, tvb, offset, 1,
1270             "authLen: %u", len);
1271         offset += 1;
1272         parameters += 1;
1273         parameters_length -= 1;
1274
1275         if (parameters_length < len)
1276                 return;
1277         proto_tree_add_text(parameters_tree, tvb, offset, len,
1278             "authDigest: %s", bytes_to_str(parameters, len));
1279         offset += len;
1280         parameters += len;
1281         parameters_length -= len;
1282
1283         if (parameters_length < 1)
1284                 return;
1285         proto_tree_add_text(parameters_tree, tvb, offset, parameters_length,
1286             "contextSelector: %s", bytes_to_str(parameters, parameters_length));
1287 }
1288
1289 void
1290 dissect_snmp_pdu(tvbuff_t *tvb, int offset, packet_info *pinfo,
1291     proto_tree *tree, char *proto_name, int proto, gint ett)
1292 {
1293         ASN1_SCK asn1;
1294         int start;
1295         gboolean def;
1296         gboolean encrypted;
1297         guint length;
1298         guint message_length;
1299         guint global_length;
1300
1301         guint32 version;
1302         guint32 msgid;
1303         guint32 msgmax;
1304         guint32 msgsec;
1305         guint32 engineboots;
1306         guint32 enginetime;
1307
1308         guchar *msgflags;
1309         guchar *community;
1310         guchar *secparm;
1311         guchar *cengineid;
1312         guchar *cname;
1313         guchar *cryptpdu;
1314         guchar *aengineid;
1315         guchar *username;
1316         guchar *authpar;
1317         guchar *privpar;
1318         int msgflags_length;
1319         int community_length;
1320         int secparm_length;
1321         int cengineid_length;
1322         int cname_length;
1323         int cryptpdu_length;
1324         int aengineid_length;
1325         int username_length;
1326         int authpar_length;
1327         int privpar_length;
1328
1329         guint pdu_type;
1330         guint pdu_length;
1331
1332         proto_tree *snmp_tree = NULL;
1333         proto_tree *global_tree = NULL;
1334         proto_tree *flags_tree = NULL;
1335         proto_tree *secur_tree = NULL;
1336         proto_item *item = NULL;
1337         int ret;
1338         guint cls, con, tag;
1339
1340         if (check_col(pinfo->cinfo, COL_PROTOCOL))
1341                 col_add_str(pinfo->cinfo, COL_PROTOCOL, proto_name);
1342
1343         if (tree) {
1344                 item = proto_tree_add_item(tree, proto, tvb, offset, -1, FALSE);
1345                 snmp_tree = proto_item_add_subtree(item, ett);
1346         }
1347
1348         /* NOTE: we have to parse the message piece by piece, since the
1349          * capture length may be less than the message length: a 'global'
1350          * parsing is likely to fail.
1351          */
1352         /* parse the SNMP header */
1353         asn1_open(&asn1, tvb, offset);
1354         ret = asn1_sequence_decode(&asn1, &message_length, &length);
1355         if (ret != ASN1_ERR_NOERROR) {
1356                 dissect_snmp_parse_error(tvb, offset, pinfo, snmp_tree,
1357                         "message header", ret);
1358                 return;
1359         }
1360         offset += length;
1361
1362         ret = asn1_uint32_decode (&asn1, &version, &length);
1363         if (ret != ASN1_ERR_NOERROR) {
1364                 dissect_snmp_parse_error(tvb, offset, pinfo, snmp_tree,
1365                     "version number", ret);
1366                 return;
1367         }
1368         if (snmp_tree) {
1369                 proto_tree_add_text(snmp_tree, tvb, offset, length,
1370                     "Version: %s",
1371                     val_to_str(version, versions, "Unknown version %#x"));
1372         }
1373         offset += length;
1374
1375
1376         switch (version) {
1377         case SNMP_VERSION_1:
1378         case SNMP_VERSION_2c:
1379                 ret = asn1_octet_string_decode (&asn1, &community,
1380                     &community_length, &length);
1381                 if (ret != ASN1_ERR_NOERROR) {
1382                         dissect_snmp_parse_error(tvb, offset, pinfo, snmp_tree,
1383                             "community", ret);
1384                         return;
1385                 }
1386                 if (tree) {
1387                         proto_tree_add_text(snmp_tree, tvb, offset, length,
1388                             "Community: %.*s", community_length,
1389                             SAFE_STRING(community));
1390                 }
1391                 g_free(community);
1392                 offset += length;
1393                 break;
1394         case SNMP_VERSION_2u:
1395                 ret = asn1_octet_string_decode (&asn1, &community,
1396                     &community_length, &length);
1397                 if (tree) {
1398                         dissect_snmp2u_parameters(snmp_tree, tvb, offset, length,
1399                             community, community_length);
1400                 }
1401                 g_free(community);
1402                 offset += length;
1403                 break;
1404         case SNMP_VERSION_3:
1405                 ret = asn1_sequence_decode(&asn1, &global_length, &length);
1406                 if (ret != ASN1_ERR_NOERROR) {
1407                         dissect_snmp_parse_error(tvb, offset, pinfo, snmp_tree,
1408                                 "message global header", ret);
1409                         return;
1410                 }
1411                 if (snmp_tree) {
1412                         item = proto_tree_add_text(snmp_tree, tvb, offset,
1413                             global_length + length, "Message Global Header");
1414                         global_tree = proto_item_add_subtree(item, ett_global);
1415                         proto_tree_add_text(global_tree, tvb, offset,
1416                             length,
1417                             "Message Global Header Length: %d", global_length);
1418                 }
1419                 offset += length;
1420                 ret = asn1_uint32_decode (&asn1, &msgid, &length);
1421                 if (ret != ASN1_ERR_NOERROR) {
1422                         dissect_snmp_parse_error(tvb, offset, pinfo, snmp_tree,
1423                             "message id", ret);
1424                         return;
1425                 }
1426                 if (global_tree) {
1427                         proto_tree_add_text(global_tree, tvb, offset,
1428                             length, "Message ID: %d", msgid);
1429                 }
1430                 offset += length;
1431                 ret = asn1_uint32_decode (&asn1, &msgmax, &length);
1432                 if (ret != ASN1_ERR_NOERROR) {
1433                         dissect_snmp_parse_error(tvb, offset, pinfo, snmp_tree,
1434                             "message max size", ret);
1435                         return;
1436                 }
1437                 if (global_tree) {
1438                         proto_tree_add_text(global_tree, tvb, offset,
1439                             length, "Message Max Size: %d", msgmax);
1440                 }
1441                 offset += length;
1442                 ret = asn1_octet_string_decode (&asn1, &msgflags,
1443                     &msgflags_length, &length);
1444                 if (ret != ASN1_ERR_NOERROR) {
1445                         dissect_snmp_parse_error(tvb, offset, pinfo, snmp_tree,
1446                             "message flags", ret);
1447                         return;
1448                 }
1449                 if (msgflags_length != 1) {
1450                         dissect_snmp_parse_error(tvb, offset, pinfo, snmp_tree,
1451                             "message flags wrong length", ret);
1452                         g_free(msgflags);
1453                         return;
1454                 }
1455                 if (global_tree) {
1456                         item = proto_tree_add_uint_format(global_tree,
1457                             hf_snmpv3_flags, tvb, offset, length,
1458                             msgflags[0], "Flags: 0x%02x", msgflags[0]);
1459                         flags_tree = proto_item_add_subtree(item, ett_flags);
1460                         proto_tree_add_boolean(flags_tree, hf_snmpv3_flags_report,
1461                             tvb, offset, length, msgflags[0]);
1462                         proto_tree_add_boolean(flags_tree, hf_snmpv3_flags_crypt,
1463                             tvb, offset, length, msgflags[0]);
1464                         proto_tree_add_boolean(flags_tree, hf_snmpv3_flags_auth,
1465                             tvb, offset, length, msgflags[0]);
1466                 }
1467                 encrypted = msgflags[0] & TH_CRYPT;
1468                 g_free(msgflags);
1469                 offset += length;
1470                 ret = asn1_uint32_decode (&asn1, &msgsec, &length);
1471                 if (ret != ASN1_ERR_NOERROR) {
1472                         dissect_snmp_parse_error(tvb, offset, pinfo, snmp_tree,
1473                             "message security model", ret);
1474                         return;
1475                 }
1476                 if (global_tree) {
1477                         proto_tree_add_text(global_tree, tvb, offset,
1478                             length, "Message Security Model: %s",
1479                             val_to_str(msgsec, sec_models,
1480                             "Unknown model %#x"));
1481                 }
1482                 offset += length;
1483                 switch(msgsec) {
1484                 case SNMP_SEC_USM:
1485                         start = asn1.offset;
1486                         ret = asn1_header_decode (&asn1, &cls, &con, &tag,
1487                             &def, &secparm_length);
1488                         length = asn1.offset - start;
1489                         if (cls != ASN1_UNI && con != ASN1_PRI &&
1490                             tag != ASN1_OTS) {
1491                                 dissect_snmp_parse_error(tvb, offset, pinfo,
1492                                     snmp_tree, "Message Security Parameters",
1493                                     ASN1_ERR_WRONG_TYPE);
1494                                 return;
1495                         }
1496                         if (snmp_tree) {
1497                                 item = proto_tree_add_text(snmp_tree, tvb,
1498                                     offset, secparm_length + length,
1499                                     "Message Security Parameters");
1500                                 secur_tree = proto_item_add_subtree(item,
1501                                     ett_secur);
1502                                 proto_tree_add_text(secur_tree, tvb, offset,
1503                                     length,
1504                                     "Message Security Parameters Length: %d",
1505                                     secparm_length);
1506                         }
1507                         offset += length;
1508                         ret = asn1_sequence_decode(&asn1, &secparm_length,
1509                             &length);
1510                         if (ret != ASN1_ERR_NOERROR) {
1511                                 dissect_snmp_parse_error(tvb, offset, pinfo,
1512                                     snmp_tree, "USM sequence header", ret);
1513                                 return;
1514                         }
1515                         offset += length;
1516                         ret = asn1_octet_string_decode (&asn1, &aengineid,
1517                             &aengineid_length, &length);
1518                         if (ret != ASN1_ERR_NOERROR) {
1519                                 dissect_snmp_parse_error(tvb, offset, pinfo,
1520                                     snmp_tree, "authoritative engine id", ret);
1521                                 return;
1522                         }
1523                         if (secur_tree) {
1524                                 proto_tree_add_text(secur_tree, tvb, offset,
1525                                     length, "Authoritative Engine ID: %s",
1526                                     bytes_to_str(aengineid, aengineid_length));
1527                         }
1528                         g_free(aengineid);
1529                         offset += length;
1530                         ret = asn1_uint32_decode (&asn1, &engineboots, &length);
1531                         if (ret != ASN1_ERR_NOERROR) {
1532                                 dissect_snmp_parse_error(tvb, offset, pinfo,
1533                                     snmp_tree, "engine boots", ret);
1534                                 return;
1535                         }
1536                         if (secur_tree) {
1537                                 proto_tree_add_text(secur_tree, tvb,
1538                                     offset, length, "Engine Boots: %d",
1539                                     engineboots);
1540                         }
1541                         offset += length;
1542                         ret = asn1_uint32_decode (&asn1, &enginetime, &length);
1543                         if (ret != ASN1_ERR_NOERROR) {
1544                                 dissect_snmp_parse_error(tvb, offset, pinfo,
1545                                     snmp_tree,  "engine time", ret);
1546                                 return;
1547                         }
1548                         if (secur_tree) {
1549                                 proto_tree_add_text(secur_tree, tvb,
1550                                     offset, length, "Engine Time: %d",
1551                                     enginetime);
1552                         }
1553                         offset += length;
1554                         ret = asn1_octet_string_decode (&asn1, &username,
1555                             &username_length, &length);
1556                         if (ret != ASN1_ERR_NOERROR) {
1557                                 dissect_snmp_parse_error(tvb, offset, pinfo,
1558                                     snmp_tree, "user name", ret);
1559                                 return;
1560                         }
1561                         if (secur_tree) {
1562                                 proto_tree_add_text(secur_tree, tvb, offset,
1563                                     length, "User Name: %.*s",
1564                                     username_length,
1565                                     SAFE_STRING(username));
1566                         }
1567                         g_free(username);
1568                         offset += length;
1569                         ret = asn1_octet_string_decode (&asn1, &authpar,
1570                             &authpar_length, &length);
1571                         if (ret != ASN1_ERR_NOERROR) {
1572                                 dissect_snmp_parse_error(tvb, offset, pinfo,
1573                                     snmp_tree, "authentication parameter", ret);
1574                                 return;
1575                         }
1576                         if (secur_tree) {
1577                                 proto_tree_add_text(secur_tree, tvb, offset,
1578                                     length, "Authentication Parameter: %s",
1579                                     bytes_to_str(authpar, authpar_length));
1580                         }
1581                         g_free(authpar);
1582                         offset += length;
1583                         ret = asn1_octet_string_decode (&asn1, &privpar,
1584                             &privpar_length, &length);
1585                         if (ret != ASN1_ERR_NOERROR) {
1586                                 dissect_snmp_parse_error(tvb, offset, pinfo,
1587                                     snmp_tree, "privacy parameter", ret);
1588                                 return;
1589                         }
1590                         if (secur_tree) {
1591                                 proto_tree_add_text(secur_tree, tvb, offset,
1592                                     length, "Privacy Parameter: %s",
1593                                     bytes_to_str(privpar, privpar_length));
1594                         }
1595                         g_free(privpar);
1596                         offset += length;
1597                         break;
1598                 default:
1599                         ret = asn1_octet_string_decode (&asn1,
1600                             &secparm, &secparm_length, &length);
1601                         if (ret != ASN1_ERR_NOERROR) {
1602                                 dissect_snmp_parse_error(tvb, offset, pinfo,
1603                                     snmp_tree, "Message Security Parameters",
1604                                     ret);
1605                                 return;
1606                         }
1607                         if (snmp_tree) {
1608                                 proto_tree_add_text(snmp_tree, tvb, offset,
1609                                     length,
1610                                     "Message Security Parameters Data"
1611                                     " (%d bytes)", secparm_length);
1612                         }
1613                         g_free(secparm);
1614                         offset += length;
1615                         break;
1616                 }
1617                 /* PDU starts here */
1618                 if (encrypted) {
1619                         ret = asn1_octet_string_decode (&asn1, &cryptpdu,
1620                             &cryptpdu_length, &length);
1621                         if (ret != ASN1_ERR_NOERROR) {
1622                                 dissect_snmp_parse_error(tvb, offset, pinfo,
1623                                     snmp_tree, "encrypted PDU header", ret);
1624                                 return;
1625                         }
1626                         proto_tree_add_text(snmp_tree, tvb, offset, length,
1627                             "Encrypted PDU (%d bytes)", length);
1628                         g_free(cryptpdu);
1629                         if (check_col(pinfo->cinfo, COL_INFO))
1630                                 col_set_str(pinfo->cinfo, COL_INFO, "Encrypted PDU");
1631                         return;
1632                 }
1633                 ret = asn1_sequence_decode(&asn1, &global_length, &length);
1634                 if (ret != ASN1_ERR_NOERROR) {
1635                         dissect_snmp_parse_error(tvb, offset, pinfo, snmp_tree,
1636                                 "PDU header", ret);
1637                         return;
1638                 }
1639                 offset += length;
1640                 ret = asn1_octet_string_decode (&asn1, &cengineid,
1641                     &cengineid_length, &length);
1642                 if (ret != ASN1_ERR_NOERROR) {
1643                         dissect_snmp_parse_error(tvb, offset, pinfo, snmp_tree,
1644                             "context engine id", ret);
1645                         return;
1646                 }
1647                 if (snmp_tree) {
1648                         proto_tree_add_text(snmp_tree, tvb, offset, length,
1649                             "Context Engine ID: %s",
1650                             bytes_to_str(cengineid, cengineid_length));
1651                 }
1652                 g_free(cengineid);
1653                 offset += length;
1654                 ret = asn1_octet_string_decode (&asn1, &cname,
1655                     &cname_length, &length);
1656                 if (ret != ASN1_ERR_NOERROR) {
1657                         dissect_snmp_parse_error(tvb, offset, pinfo, snmp_tree,
1658                             "context name", ret);
1659                         return;
1660                 }
1661                 if (snmp_tree) {
1662                         proto_tree_add_text(snmp_tree, tvb, offset, length,
1663                             "Context Name: %.*s", cname_length,
1664                             SAFE_STRING(cname));
1665                 }
1666                 g_free(cname);
1667                 offset += length;
1668                 break;
1669         default:
1670                 dissect_snmp_error(tvb, offset, pinfo, snmp_tree,
1671                     "PDU for unknown version of SNMP");
1672                 return;
1673         }
1674
1675         start = asn1.offset;
1676         ret = asn1_header_decode (&asn1, &cls, &con, &pdu_type, &def,
1677             &pdu_length);
1678         if (ret != ASN1_ERR_NOERROR) {
1679                 dissect_snmp_parse_error(tvb, offset, pinfo, snmp_tree,
1680                     "PDU type", ret);
1681                 return;
1682         }
1683         if (cls != ASN1_CTX || con != ASN1_CON) {
1684                 dissect_snmp_parse_error(tvb, offset, pinfo, snmp_tree,
1685                     "PDU type", ASN1_ERR_WRONG_TYPE);
1686                 return;
1687         }
1688         dissect_common_pdu(tvb, offset, pinfo, snmp_tree, asn1, pdu_type, start);
1689 }
1690
1691 static void
1692 dissect_smux_pdu(tvbuff_t *tvb, int offset, packet_info *pinfo,
1693     proto_tree *tree, int proto, gint ett)
1694 {
1695         ASN1_SCK asn1;
1696         int start;
1697         gboolean def;
1698         guint length;
1699
1700         guint pdu_type;
1701         char *pdu_type_string;
1702         guint pdu_length;
1703
1704         guint32 version;
1705         guint32 cause;
1706         guint32 priority;
1707         guint32 operation;
1708         guint32 commit;
1709
1710         guchar *password;
1711         int password_length;
1712
1713         guchar *application;
1714         int application_length;
1715
1716         subid_t *regid;
1717         guint regid_length;
1718
1719         gchar *oid_string;
1720
1721         proto_tree *smux_tree = NULL;
1722         proto_item *item = NULL;
1723         int ret;
1724         guint cls, con;
1725
1726         if (check_col(pinfo->cinfo, COL_PROTOCOL))
1727                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "SMUX");
1728
1729         if (tree) {
1730                 item = proto_tree_add_item(tree, proto, tvb, offset, -1, FALSE);
1731                 smux_tree = proto_item_add_subtree(item, ett);
1732         }
1733
1734         /* NOTE: we have to parse the message piece by piece, since the
1735          * capture length may be less than the message length: a 'global'
1736          * parsing is likely to fail.
1737          */
1738         /* parse the SNMP header */
1739         asn1_open(&asn1, tvb, offset);
1740         start = asn1.offset;
1741         ret = asn1_header_decode (&asn1, &cls, &con, &pdu_type, &def,
1742             &pdu_length);
1743         if (ret != ASN1_ERR_NOERROR) {
1744                 dissect_snmp_parse_error(tvb, offset, pinfo, smux_tree,
1745                     "PDU type", ret);
1746                 return;
1747         }
1748
1749         /* Dissect SMUX here */
1750         if (cls == ASN1_APL && con == ASN1_CON && pdu_type == SMUX_MSG_OPEN) {
1751                 pdu_type_string = val_to_str(pdu_type, smux_types,
1752                     "Unknown PDU type %#x");
1753                 if (check_col(pinfo->cinfo, COL_INFO))
1754                         col_add_str(pinfo->cinfo, COL_INFO, pdu_type_string);
1755                 length = asn1.offset - start;
1756                 if (tree) {
1757                         proto_tree_add_text(smux_tree, tvb, offset, length,
1758                             "PDU type: %s", pdu_type_string);
1759                 }
1760                 offset += length;
1761                 ret = asn1_uint32_decode (&asn1, &version, &length);
1762                 if (ret != ASN1_ERR_NOERROR) {
1763                         dissect_snmp_parse_error(tvb, offset, pinfo, smux_tree,
1764                             "version", ret);
1765                         return;
1766                 }
1767                 if (tree) {
1768                         proto_tree_add_text(smux_tree, tvb, offset, length,
1769                             "Version: %d", version);
1770                 }
1771                 offset += length;
1772
1773                 ret = asn1_oid_decode (&asn1, &regid, &regid_length, &length);
1774                 if (ret != ASN1_ERR_NOERROR) {
1775                         dissect_snmp_parse_error(tvb, offset, pinfo, smux_tree,
1776                             "registration OID", ret);
1777                         return;
1778                 }
1779                 if (tree) {
1780                         oid_string = format_oid(regid, regid_length);
1781                         proto_tree_add_text(smux_tree, tvb, offset, length,
1782                             "Registration: %s", oid_string);
1783                         g_free(oid_string);
1784                 }
1785                 g_free(regid);
1786                 offset += length;
1787
1788                 ret = asn1_octet_string_decode (&asn1, &application,
1789                     &application_length, &length);
1790                 if (ret != ASN1_ERR_NOERROR) {
1791                         dissect_snmp_parse_error(tvb, offset, pinfo, smux_tree,
1792                             "application", ret);
1793                         return;
1794                 }
1795                 if (tree) {
1796                         proto_tree_add_text(smux_tree, tvb, offset, length,
1797                             "Application: %.*s", application_length,
1798                              SAFE_STRING(application));
1799                 }
1800                 g_free(application);
1801                 offset += length;
1802
1803                 ret = asn1_octet_string_decode (&asn1, &password,
1804                     &password_length, &length);
1805                 if (ret != ASN1_ERR_NOERROR) {
1806                         dissect_snmp_parse_error(tvb, offset, pinfo, smux_tree,
1807                             "password", ret);
1808                         return;
1809                 }
1810                 if (tree) {
1811                         proto_tree_add_text(smux_tree, tvb, offset, length,
1812                             "Password: %.*s", password_length,
1813                             SAFE_STRING(password));
1814                 }
1815                 g_free(password);
1816                 offset += length;
1817                 return;
1818         }
1819         if (cls == ASN1_APL && con == ASN1_PRI && pdu_type == SMUX_MSG_CLOSE) {
1820                 pdu_type_string = val_to_str(pdu_type, smux_types,
1821                     "Unknown PDU type %#x");
1822                 if (check_col(pinfo->cinfo, COL_INFO))
1823                         col_add_str(pinfo->cinfo, COL_INFO, pdu_type_string);
1824                 length = asn1.offset - start;
1825                 if (tree) {
1826                         proto_tree_add_text(smux_tree, tvb, offset, length,
1827                             "PDU type: %s", pdu_type_string);
1828                 }
1829                 offset += length;
1830                 ret = asn1_uint32_value_decode (&asn1, pdu_length, &cause);
1831                 if (ret != ASN1_ERR_NOERROR) {
1832                         dissect_snmp_parse_error(tvb, offset, pinfo, smux_tree,
1833                             "cause", ret);
1834                         return;
1835                 }
1836                 if (tree) {
1837                         proto_tree_add_text(smux_tree, tvb, offset,
1838                             pdu_length, "Cause: %s",
1839                             val_to_str(cause, smux_close,
1840                                 "Unknown cause %#x"));
1841                 }
1842                 offset += pdu_length;
1843                 return;
1844         }
1845         if (cls == ASN1_APL && con == ASN1_CON && pdu_type == SMUX_MSG_RREQ) {
1846                 pdu_type_string = val_to_str(pdu_type, smux_types,
1847                     "Unknown PDU type %#x");
1848                 if (check_col(pinfo->cinfo, COL_INFO))
1849                         col_add_str(pinfo->cinfo, COL_INFO, pdu_type_string);
1850                 length = asn1.offset - start;
1851                 if (tree) {
1852                         proto_tree_add_text(smux_tree, tvb, offset, length,
1853                             "PDU type: %s", pdu_type_string);
1854                 }
1855                 offset += length;
1856                 ret = asn1_oid_decode (&asn1, &regid, &regid_length, &length);
1857                 if (ret != ASN1_ERR_NOERROR) {
1858                         dissect_snmp_parse_error(tvb, offset, pinfo, smux_tree,
1859                             "registration subtree", ret);
1860                         return;
1861                 }
1862                 if (tree) {
1863                         oid_string = format_oid(regid, regid_length);
1864                         proto_tree_add_text(smux_tree, tvb, offset, length,
1865                             "Registration: %s", oid_string);
1866                         g_free(oid_string);
1867                 }
1868                 g_free(regid);
1869                 offset += length;
1870
1871                 ret = asn1_uint32_decode (&asn1, &priority, &length);
1872                 if (ret != ASN1_ERR_NOERROR) {
1873                         dissect_snmp_parse_error(tvb, offset, pinfo, smux_tree,
1874                             "priority", ret);
1875                         return;
1876                 }
1877                 if (tree) {
1878                         proto_tree_add_text(smux_tree, tvb, offset, length,
1879                             "Priority: %d", priority);
1880                 }
1881                 offset += length;
1882
1883                 ret = asn1_uint32_decode (&asn1, &operation, &length);
1884                 if (ret != ASN1_ERR_NOERROR) {
1885                         dissect_snmp_parse_error(tvb, offset, pinfo, smux_tree,
1886                             "operation", ret);
1887                         return;
1888                 }
1889                 if (tree) {
1890                         proto_tree_add_text(smux_tree, tvb, offset, length,
1891                             "Operation: %s",
1892                             val_to_str(operation, smux_rreq,
1893                                 "Unknown operation %#x"));
1894                 }
1895                 offset += length;
1896                 return;
1897         }
1898         if (cls == ASN1_APL && con == ASN1_PRI && pdu_type == SMUX_MSG_RRSP) {
1899                 pdu_type_string = val_to_str(pdu_type, smux_types,
1900                     "Unknown PDU type %#x");
1901                 if (check_col(pinfo->cinfo, COL_INFO))
1902                         col_add_str(pinfo->cinfo, COL_INFO, pdu_type_string);
1903                 length = asn1.offset - start;
1904                 if (tree) {
1905                         proto_tree_add_text(smux_tree, tvb, offset, length,
1906                             "PDU type: %s", pdu_type_string);
1907                 }
1908                 offset += length;
1909                 ret = asn1_uint32_value_decode (&asn1, pdu_length, &priority);
1910                 if (ret != ASN1_ERR_NOERROR) {
1911                         dissect_snmp_parse_error(tvb, offset, pinfo, smux_tree,
1912                             "priority", ret);
1913                         return;
1914                 }
1915                 if (tree) {
1916                         proto_tree_add_text(smux_tree, tvb, offset,
1917                             pdu_length, "%s",
1918                             val_to_str(priority, smux_prio,
1919                                 "Priority: %#x"));
1920                 }
1921                 offset += pdu_length;
1922                 return;
1923         }
1924         if (cls == ASN1_APL && con == ASN1_PRI && pdu_type == SMUX_MSG_SOUT) {
1925                 pdu_type_string = val_to_str(pdu_type, smux_types,
1926                     "Unknown PDU type %#x");
1927                 if (check_col(pinfo->cinfo, COL_INFO))
1928                         col_add_str(pinfo->cinfo, COL_INFO, pdu_type_string);
1929                 length = asn1.offset - start;
1930                 if (tree) {
1931                         proto_tree_add_text(smux_tree, tvb, offset, length,
1932                             "PDU type: %s", pdu_type_string);
1933                 }
1934                 offset += length;
1935                 ret = asn1_uint32_value_decode (&asn1, pdu_length, &commit);
1936                 if (ret != ASN1_ERR_NOERROR) {
1937                         dissect_snmp_parse_error(tvb, offset, pinfo, smux_tree,
1938                             "commit", ret);
1939                         return;
1940                 }
1941                 if (tree) {
1942                         proto_tree_add_text(smux_tree, tvb, offset,
1943                             pdu_length, "%s",
1944                             val_to_str(commit, smux_sout,
1945                                 "Unknown SOUT Value: %#x"));
1946                 }
1947                 offset += pdu_length;
1948                 return;
1949         }
1950         if (cls != ASN1_CTX || con != ASN1_CON) {
1951                 dissect_snmp_parse_error(tvb, offset, pinfo, smux_tree,
1952                     "PDU type", ASN1_ERR_WRONG_TYPE);
1953                 return;
1954         }
1955         dissect_common_pdu(tvb, offset, pinfo, smux_tree, asn1, pdu_type, start);
1956 }
1957
1958 static void
1959 dissect_snmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
1960 {
1961         conversation_t  *conversation;
1962
1963         /*
1964          * The first SNMP packet goes to the SNMP port; the second one
1965          * may come from some *other* port, but goes back to the same
1966          * IP address and port as the ones from which the first packet
1967          * came; all subsequent packets presumably go between those two
1968          * IP addresses and ports.
1969          *
1970          * If this packet went to the SNMP port, we check to see if
1971          * there's already a conversation with one address/port pair
1972          * matching the source IP address and port of this packet,
1973          * the other address matching the destination IP address of this
1974          * packet, and any destination port.
1975          *
1976          * If not, we create one, with its address 1/port 1 pair being
1977          * the source address/port of this packet, its address 2 being
1978          * the destination address of this packet, and its port 2 being
1979          * wildcarded, and give it the SNMP dissector as a dissector.
1980          */
1981         if (pinfo->destport == UDP_PORT_SNMP) {
1982           conversation = find_conversation(&pinfo->src, &pinfo->dst, PT_UDP,
1983                                            pinfo->srcport, 0, NO_PORT_B);
1984           if (conversation == NULL) {
1985             conversation = conversation_new(&pinfo->src, &pinfo->dst, PT_UDP,
1986                                             pinfo->srcport, 0, NO_PORT2);
1987             conversation_set_dissector(conversation, snmp_handle);
1988           }
1989         }
1990
1991         dissect_snmp_pdu(tvb, 0, pinfo, tree, "SNMP", proto_snmp, ett_snmp);
1992 }
1993
1994 static void
1995 dissect_smux(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
1996 {
1997         dissect_smux_pdu(tvb, 0, pinfo, tree, proto_smux, ett_smux);
1998 }
1999
2000 void
2001 proto_register_snmp(void)
2002 {
2003         static hf_register_info hf[] = {
2004                 { &hf_snmpv3_flags,
2005                 { "SNMPv3 Flags", "snmpv3.flags", FT_UINT8, BASE_HEX, NULL,
2006                     0x0, "", HFILL }},
2007                 { &hf_snmpv3_flags_auth,
2008                 { "Authenticated", "snmpv3.flags.auth", FT_BOOLEAN, 8,
2009                     TFS(&flags_set_truth), TH_AUTH, "", HFILL }},
2010                 { &hf_snmpv3_flags_crypt,
2011                 { "Encrypted", "snmpv3.flags.crypt", FT_BOOLEAN, 8,
2012                     TFS(&flags_set_truth), TH_CRYPT, "", HFILL }},
2013                 { &hf_snmpv3_flags_report,
2014                 { "Reportable", "snmpv3.flags.report", FT_BOOLEAN, 8,
2015                     TFS(&flags_set_truth), TH_REPORT, "", HFILL }},
2016         };
2017         static gint *ett[] = {
2018                 &ett_snmp,
2019                 &ett_smux,
2020                 &ett_parameters,
2021                 &ett_parameters_qos,
2022                 &ett_global,
2023                 &ett_flags,
2024                 &ett_secur,
2025         };
2026
2027 #ifdef HAVE_UCD_SNMP
2028         /*
2029          * Suppress warnings about unknown tokens - we aren't initializing
2030          * UCD SNMP in its entirety, we're just initializing the
2031          * MIB-handling part because that's all we're using, which
2032          * means that entries in the configuration file for other
2033          * pars of the library will not be handled, and we don't want
2034          * the config file reading code to whine about that.
2035          */
2036         ds_set_boolean(DS_LIBRARY_ID, DS_LIB_NO_TOKEN_WARNINGS, TRUE);
2037         ds_set_int(DS_LIBRARY_ID, DS_LIB_PRINT_SUFFIX_ONLY, 2);
2038         register_mib_handlers();
2039         read_premib_configs();
2040         init_mib();
2041         read_configs();
2042 #endif /* HAVE_UCD_SNMP */
2043         proto_snmp = proto_register_protocol("Simple Network Management Protocol",
2044             "SNMP", "snmp");
2045         proto_smux = proto_register_protocol("SNMP Multiplex Protocol",
2046             "SMUX", "smux");
2047         proto_register_field_array(proto_snmp, hf, array_length(hf));
2048         proto_register_subtree_array(ett, array_length(ett));
2049         snmp_handle = create_dissector_handle(dissect_snmp, proto_snmp);
2050 }
2051
2052 void
2053 proto_reg_handoff_snmp(void)
2054 {
2055         dissector_handle_t smux_handle;
2056
2057         dissector_add("udp.port", UDP_PORT_SNMP, snmp_handle);
2058         dissector_add("udp.port", UDP_PORT_SNMP_TRAP, snmp_handle);
2059         smux_handle = create_dissector_handle(dissect_smux, proto_smux);
2060         dissector_add("tcp.port", TCP_PORT_SMUX, smux_handle);
2061         dissector_add("ethertype", ETHERTYPE_SNMP, snmp_handle);
2062         dissector_add("ipx.socket", IPX_SOCKET_SNMP_AGENT, snmp_handle);
2063         dissector_add("ipx.socket", IPX_SOCKET_SNMP_SINK, snmp_handle);
2064         data_handle = find_dissector("data");
2065 }