/*
* Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996, 1997
* John Robert LoVerso. All rights reserved.
*
* Redistribution 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 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR 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.
*
*
* This implementation has been influenced by the CMU SNMP release,
* by Steve Waldbusser. However, this shares no code with that system.
* Additional ASN.1 insight gained from Marshall T. Rose's _The_Open_Book_.
* Earlier forms of this implementation were derived and/or inspired by an
* awk script originally written by C. Philip Wood of LANL (but later
* heavily modified by John Robert LoVerso). The copyright notice for
* that work is preserved below, even though it may not rightly apply
* to this file.
*
* Support for SNMPv2c/SNMPv3 and the ability to link the module against
* the libsmi was added by J. Schoenwaelder, Copyright (c) 1999.
*
* This started out as a very simple program, but the incremental decoding
* (into the BE structure) complicated things.
*
# Los Alamos National Laboratory
#
# Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996, 1997
# This software was produced under a U.S. Government contract
# (W-7405-ENG-36) by Los Alamos National Laboratory, which is
# operated by the University of California for the U.S. Department
# of Energy. The U.S. Government is licensed to use, reproduce,
# and distribute this software. Permission is granted to the
# public to copy and use this software without charge, provided
# that this Notice and any statement of authorship are reproduced
# on all copies. Neither the Government nor the University makes
# any warranty, express or implied, or assumes any liability or
# responsibility for the use of this software.
# @(#)snmp.awk.x 1.1 (LANL) 1/15/90
*/
/* \summary: Simple Network Management Protocol (SNMP) printer */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <netdissect-stdinc.h>
#include <stdio.h>
#include <string.h>
#ifdef USE_LIBSMI
#include <smi.h>
#endif
#include "netdissect.h"
#undef OPAQUE /* defined in <wingdi.h> */
static const char tstr[] = "[|snmp]";
/*
* Universal ASN.1 types
* (we only care about the tag values for those allowed in the Internet SMI)
*/
static const char *Universal[] = {
"U-0",
"Boolean",
"Integer",
#define INTEGER 2
"Bitstring",
"String",
#define STRING 4
"Null",
#define ASN_NULL 5
"ObjID",
#define OBJECTID 6
"ObjectDes",
"U-8","U-9","U-10","U-11", /* 8-11 */
"U-12","U-13","U-14","U-15", /* 12-15 */
"Sequence",
#define SEQUENCE 16
"Set"
};
/*
* Application-wide ASN.1 types from the Internet SMI and their tags
*/
static const char *Application[] = {
"IpAddress",
#define IPADDR 0
"Counter",
#define COUNTER 1
"Gauge",
#define GAUGE 2
"TimeTicks",
#define TIMETICKS 3
"Opaque",
#define OPAQUE 4
"C-5",
"Counter64"
#define COUNTER64 6
};
/*
* Context-specific ASN.1 types for the SNMP PDUs and their tags
*/
static const char *Context[] = {
"GetRequest",
#define GETREQ 0
"GetNextRequest",
#define GETNEXTREQ 1
"GetResponse",
#define GETRESP 2
"SetRequest",
#define SETREQ 3
"Trap",
#define TRAP 4
"GetBulk",
#define GETBULKREQ 5
"Inform",
#define INFORMREQ 6
"V2Trap",
#define V2TRAP 7
"Report"
#define REPORT 8
};
#define NOTIFY_CLASS(x) (x == TRAP || x == V2TRAP || x == INFORMREQ)
#define READ_CLASS(x) (x == GETREQ || x == GETNEXTREQ || x == GETBULKREQ)
#define WRITE_CLASS(x) (x == SETREQ)
#define RESPONSE_CLASS(x) (x == GETRESP)
#define INTERNAL_CLASS(x) (x == REPORT)
/*
* Context-specific ASN.1 types for the SNMP Exceptions and their tags
*/
static const char *Exceptions[] = {
"noSuchObject",
#define NOSUCHOBJECT 0
"noSuchInstance",
#define NOSUCHINSTANCE 1
"endOfMibView",
#define ENDOFMIBVIEW 2
};
/*
* Private ASN.1 types
* The Internet SMI does not specify any
*/
static const char *Private[] = {
"P-0"
};
/*
* error-status values for any SNMP PDU
*/
static const char *ErrorStatus[] = {
"noError",
"tooBig",
"noSuchName",
"badValue",
"readOnly",
"genErr",
"noAccess",
"wrongType",
"wrongLength",
"wrongEncoding",
"wrongValue",
"noCreation",
"inconsistentValue",
"resourceUnavailable",
"commitFailed",
"undoFailed",
"authorizationError",
"notWritable",
"inconsistentName"
};
#define DECODE_ErrorStatus(e) \
( e >= 0 && (size_t)e < sizeof(ErrorStatus)/sizeof(ErrorStatus[0]) \
? ErrorStatus[e] \
: (snprintf(errbuf, sizeof(errbuf), "err=%u", e), errbuf))
/*
* generic-trap values in the SNMP Trap-PDU
*/
static const char *GenericTrap[] = {
"coldStart",
"warmStart",
"linkDown",
"linkUp",
"authenticationFailure",
"egpNeighborLoss",
"enterpriseSpecific"
#define GT_ENTERPRISE 6
};
#define DECODE_GenericTrap(t) \
( t >= 0 && (size_t)t < sizeof(GenericTrap)/sizeof(GenericTrap[0]) \
? GenericTrap[t] \
: (snprintf(buf, sizeof(buf), "gt=%d", t), buf))
/*
* ASN.1 type class table
* Ties together the preceding Universal, Application, Context, and Private
* type definitions.
*/
#define defineCLASS(x) { "x", x, sizeof(x)/sizeof(x[0]) } /* not ANSI-C */
static const struct {
const char *name;
const char **Id;
int numIDs;
} Class[] = {
defineCLASS(Universal),
#define UNIVERSAL 0
defineCLASS(Application),
#define APPLICATION 1
defineCLASS(Context),
#define CONTEXT 2
defineCLASS(Private),
#define PRIVATE 3
defineCLASS(Exceptions),
#define EXCEPTIONS 4
};
/*
* defined forms for ASN.1 types
*/
static const char *Form[] = {
"Primitive",
#define PRIMITIVE 0
"Constructed",
#define CONSTRUCTED 1
};
/*
* A structure for the OID tree for the compiled-in MIB.
* This is stored as a general-order tree.
*/
static struct obj {
const char *desc; /* name of object */
u_char oid; /* sub-id following parent */
u_char type; /* object type (unused) */
struct obj *child, *next; /* child and next sibling pointers */
} *objp = NULL;
/*
* Include the compiled in SNMP MIB. "mib.h" is produced by feeding
* RFC-1156 format files into "makemib". "mib.h" MUST define at least
* a value for `mibroot'.
*
* In particular, this is gross, as this is including initialized structures,
* and by right shouldn't be an "include" file.
*/
#include "mib.h"
/*
* This defines a list of OIDs which will be abbreviated on output.
* Currently, this includes the prefixes for the Internet MIB, the
* private enterprises tree, and the experimental tree.
*/
#define OID_FIRST_OCTET(x, y) (((x)*40) + (y)) /* X.690 8.19.4 */
#ifndef NO_ABREV_MIB
static const uint8_t mib_oid[] = { OID_FIRST_OCTET(1, 3), 6, 1, 2, 1 };
#endif
#ifndef NO_ABREV_ENTER
static const uint8_t enterprises_oid[] = { OID_FIRST_OCTET(1, 3), 6, 1, 4, 1 };
#endif
#ifndef NO_ABREV_EXPERI
static const uint8_t experimental_oid[] = { OID_FIRST_OCTET(1, 3), 6, 1, 3 };
#endif
#ifndef NO_ABBREV_SNMPMODS
static const uint8_t snmpModules_oid[] = { OID_FIRST_OCTET(1, 3), 6, 1, 6, 3 };
#endif
#define OBJ_ABBREV_ENTRY(prefix, obj) \
{ prefix, &_ ## obj ## _obj, obj ## _oid, sizeof (obj ## _oid) }
static const struct obj_abrev {
const char *prefix; /* prefix for this abrev */
struct obj *node; /* pointer into object table */
const uint8_t *oid; /* ASN.1 encoded OID */
size_t oid_len; /* length of OID */
} obj_abrev_list[] = {
#ifndef NO_ABREV_MIB
/* .iso.org.dod.internet.mgmt.mib */
OBJ_ABBREV_ENTRY("", mib),
#endif
#ifndef NO_ABREV_ENTER
/* .iso.org.dod.internet.private.enterprises */
OBJ_ABBREV_ENTRY("E:", enterprises),
#endif
#ifndef NO_ABREV_EXPERI
/* .iso.org.dod.internet.experimental */
OBJ_ABBREV_ENTRY("X:", experimental),
#endif
#ifndef NO_ABBREV_SNMPMODS
/* .iso.org.dod.internet.snmpV2.snmpModules */
OBJ_ABBREV_ENTRY("S:", snmpModules),
#endif
{ 0,0,0,0 }
};
/*
* This is used in the OID print routine to walk down the object tree
* rooted at `mibroot'.
*/
#define OBJ_PRINT(o, suppressdot) \
{ \
if (objp) { \
do { \
if ((o) == objp->oid) \
break; \
} while ((objp = objp->next) != NULL); \
} \
if (objp) { \
ND_PRINT((ndo, suppressdot?"%s":".%s", objp->desc)); \
objp = objp->child; \
} else \
ND_PRINT((ndo, suppressdot?"%u":".%u", (o))); \
}
/*
* This is the definition for the Any-Data-Type storage used purely for
* temporary internal representation while decoding an ASN.1 data stream.
*/
struct be {
uint32_t asnlen;
union {
const uint8_t *raw;
int32_t integer;
uint32_t uns;
const u_char *str;
uint64_t uns64;
} data;
u_short id;
u_char form, class; /* tag info */
u_char type;
#define BE_ANY 255
#define BE_NONE 0
#define BE_NULL 1
#define BE_OCTET 2
#define BE_OID 3
#define BE_INT 4
#define BE_UNS 5
#define BE_STR 6
#define BE_SEQ 7
#define BE_INETADDR 8
#define BE_PDU 9
#define BE_UNS64 10
#define BE_NOSUCHOBJECT 128
#define BE_NOSUCHINST 129
#define BE_ENDOFMIBVIEW 130
};
/*
* SNMP versions recognized by this module
*/
static const char *SnmpVersion[] = {
"SNMPv1",
#define SNMP_VERSION_1 0
"SNMPv2c",
#define SNMP_VERSION_2 1
"SNMPv2u",
#define SNMP_VERSION_2U 2
"SNMPv3"
#define SNMP_VERSION_3 3
};
/*
* Defaults for SNMP PDU components
*/
#define DEF_COMMUNITY "public"
/*
* constants for ASN.1 decoding
*/
#define OIDMUX 40
#define ASNLEN_INETADDR 4
#define ASN_SHIFT7 7
#define ASN_SHIFT8 8
#define ASN_BIT8 0x80
#define ASN_LONGLEN 0x80
#define ASN_ID_BITS 0x1f
#define ASN_FORM_BITS 0x20
#define ASN_FORM_SHIFT 5
#define ASN_CLASS_BITS 0xc0
#define ASN_CLASS_SHIFT 6
#define ASN_ID_EXT 0x1f /* extension ID in tag field */
/*
* This decodes the next ASN.1 object in the stream pointed to by "p"
* (and of real-length "len") and stores the intermediate data in the
* provided BE object.
*
* This returns -l if it fails (i.e., the ASN.1 stream is not valid).
* O/w, this returns the number of bytes parsed from "p".
*/
static int
asn1_parse(netdissect_options *ndo,
register const u_char *p, u_int len, struct be *elem)
{
u_char form, class, id;
int i, hdr;
elem->asnlen = 0;
elem->type = BE_ANY;
if (len < 1) {
ND_PRINT((ndo, "[nothing to parse]"));
return -1;
}
ND_TCHECK(*p);
/*
* it would be nice to use a bit field, but you can't depend on them.
* +---+---+---+---+---+---+---+---+
* + class |frm| id |
* +---+---+---+---+---+---+---+---+
* 7 6 5 4 3 2 1 0
*/
id = *p & ASN_ID_BITS; /* lower 5 bits, range 00-1f */
#ifdef notdef
form = (*p & 0xe0) >> 5; /* move upper 3 bits to lower 3 */
class = form >> 1; /* bits 7&6 -> bits 1&0, range 0-3 */
form &= 0x1; /* bit 5 -> bit 0, range 0-1 */
#else
form = (u_char)(*p & ASN_FORM_BITS) >> ASN_FORM_SHIFT;
class = (u_char)(*p & ASN_CLASS_BITS) >> ASN_CLASS_SHIFT;
#endif
elem->form = form;
elem->class = class;
elem->id = id;
p++; len--; hdr = 1;
/* extended tag field */
if (id == ASN_ID_EXT) {
/*
* The ID follows, as a sequence of octets with the
* 8th bit set and the remaining 7 bits being
* the next 7 bits of the value, terminated with
* an octet with the 8th bit not set.
*
* First, assemble all the octets with the 8th
* bit set. XXX - this doesn't handle a value
* that won't fit in 32 bits.
*/
id = 0;
ND_TCHECK(*p);
while (*p & ASN_BIT8) {
if (len < 1) {
ND_PRINT((ndo, "[Xtagfield?]"));
return -1;
}
id = (id << 7) | (*p & ~ASN_BIT8);
len--;
hdr++;
p++;
ND_TCHECK(*p);
}
if (len < 1) {
ND_PRINT((ndo, "[Xtagfield?]"));
return -1;
}
ND_TCHECK(*p);
elem->id = id = (id << 7) | *p;
--len;
++hdr;
++p;
}
if (len < 1) {
ND_PRINT((ndo, "[no asnlen]"));
return -1;
}
ND_TCHECK(*p);
elem->asnlen = *p;
p++; len--; hdr++;
if (elem->asnlen & ASN_BIT8) {
uint32_t noct = elem->asnlen % ASN_BIT8;
elem->asnlen = 0;
if (len < noct) {
ND_PRINT((ndo, "[asnlen? %d<%d]", len, noct));
return -1;
}
ND_TCHECK2(*p, noct);
for (; noct-- > 0; len--, hdr++)
elem->asnlen = (elem->asnlen << ASN_SHIFT8) | *p++;
}
if (len < elem->asnlen) {
ND_PRINT((ndo, "[len%d<asnlen%u]", len, elem->asnlen));
return -1;
}
if (form >= sizeof(Form)/sizeof(Form[0])) {
ND_PRINT((ndo, "[form?%d]", form));
return -1;
}
if (class >= sizeof(Class)/sizeof(Class[0])) {
ND_PRINT((ndo, "[class?%c/%d]", *Form[form], class));
return -1;
}
if ((int)id >= Class[class].numIDs) {
ND_PRINT((ndo, "[id?%c/%s/%d]", *Form[form], Class[class].name, id));
return -1;
}
ND_TCHECK2(*p, elem->asnlen);
switch (form) {
case PRIMITIVE:
switch (class) {
case UNIVERSAL:
switch (id) {
case STRING:
elem->type = BE_STR;
elem->data.str = p;
break;
case INTEGER: {
register int32_t data;
elem->type = BE_INT;
data = 0;
if (elem->asnlen == 0) {
ND_PRINT((ndo, "[asnlen=0]"));
return -1;
}
if (*p & ASN_BIT8) /* negative */
data = -1;
for (i = elem->asnlen; i-- > 0; p++)
data = (data << ASN_SHIFT8) | *p;
elem->data.integer = data;
break;
}
case OBJECTID:
elem->type = BE_OID;
elem->data.raw = (const uint8_t *)p;
break;
case ASN_NULL:
elem->type = BE_NULL;
elem->data.raw = NULL;
break;
default:
elem->type = BE_OCTET;
elem->data.raw = (const uint8_t *)p;
ND_PRINT((ndo, "[P/U/%s]", Class[class].Id[id]));
break;
}
break;
case APPLICATION:
switch (id) {
case IPADDR:
elem->type = BE_INETADDR;
elem->data.raw = (const uint8_t *)p;
break;
case COUNTER:
case GAUGE:
case TIMETICKS: {
register uint32_t data;
elem->type = BE_UNS;
data = 0;
for (i = elem->asnlen; i-- > 0; p++)
data = (data << 8) + *p;
elem->data.uns = data;
break;
}
case COUNTER64: {
register uint64_t data64;
elem->type = BE_UNS64;
data64 = 0;
for (i = elem->asnlen; i-- > 0; p++)
data64 = (data64 << 8) + *p;
elem->data.uns64 = data64;
break;
}
default:
elem->type = BE_OCTET;
elem->data.raw = (const uint8_t *)p;
ND_PRINT((ndo, "[P/A/%s]",
Class[class].Id[id]));
break;
}
break;
case CONTEXT:
switch (id) {
case NOSUCHOBJECT:
elem->type = BE_NOSUCHOBJECT;
elem->data.raw = NULL;
break;
case NOSUCHINSTANCE:
elem->type = BE_NOSUCHINST;
elem->data.raw = NULL;
break;
case ENDOFMIBVIEW:
elem->type = BE_ENDOFMIBVIEW;
elem->data.raw = NULL;
break;
}
break;
default:
ND_PRINT((ndo, "[P/%s/%s]", Class[class].name, Class[class].Id[id]));
elem->type = BE_OCTET;
elem->data.raw = (const uint8_t *)p;
break;
}
break;
case CONSTRUCTED:
switch (class) {
case UNIVERSAL:
switch (id) {
case SEQUENCE:
elem->type = BE_SEQ;
elem->data.raw = (const uint8_t *)p;
break;
default:
elem->type = BE_OCTET;
elem->data.raw = (const uint8_t *)p;
ND_PRINT((ndo, "C/U/%s", Class[class].Id[id]));
break;
}
break;
case CONTEXT:
elem->type = BE_PDU;
elem->data.raw = (const uint8_t *)p;
break;
default:
elem->type = BE_OCTET;
elem->data.raw = (const uint8_t *)p;
ND_PRINT((ndo, "C/%s/%s", Class[class].name, Class[class].Id[id]));
break;
}
break;
}
p += elem->asnlen;
len -= elem->asnlen;
return elem->asnlen + hdr;
trunc:
ND_PRINT((ndo, "%s", tstr));
return -1;
}
static int
asn1_print_octets(netdissect_options *ndo, struct be *elem)
{
const u_char *p = (const u_char *)elem->data.raw;
uint32_t asnlen = elem->asnlen;
uint32_t i;
ND_TCHECK2(*p, asnlen);
for (i = asnlen; i-- > 0; p++)
ND_PRINT((ndo, "_%.2x", *p));
return 0;
trunc:
ND_PRINT((ndo, "%s", tstr));
return -1;
}
static int
asn1_print_string(netdissect_options *ndo, struct be *elem)
{
register int printable = 1, first = 1;
const u_char *p;
uint32_t asnlen = elem->asnlen;
uint32_t i;
p = elem->data.str;
ND_TCHECK2(*p, asnlen);
for (i = asnlen; printable && i-- > 0; p++)
printable = ND_ISPRINT(*p);
p = elem->data.str;
if (printable) {
ND_PRINT((ndo, "\""));
if (fn_printn(ndo, p, asnlen, ndo->ndo_snapend)) {
ND_PRINT((ndo, "\""));
goto trunc;
}
ND_PRINT((ndo, "\""));
} else {
for (i = asnlen; i-- > 0; p++) {
ND_PRINT((ndo, first ? "%.2x" : "_%.2x", *p));
first = 0;
}
}
return 0;
trunc:
ND_PRINT((ndo, "%s", tstr));
return -1;
}
/*
* Display the ASN.1 object represented by the BE object.
* This used to be an integral part of asn1_parse() before the intermediate
* BE form was added.
*/
static int
asn1_print(netdissect_options *ndo,
struct be *elem)
{
const u_char *p;
uint32_t asnlen = elem->asnlen;
uint32_t i;
switch (elem->type) {
case BE_OCTET:
if (asn1_print_octets(ndo, elem) == -1)
return -1;
break;
case BE_NULL:
break;
case BE_OID: {
int o = 0, first = -1;
p = (const u_char *)elem->data.raw;
i = asnlen;
if (!ndo->ndo_nflag && asnlen > 2) {
const struct obj_abrev *a = &obj_abrev_list[0];
for (; a->node; a++) {
if (i < a->oid_len)
continue;
if (!ND_TTEST2(*p, a->oid_len))
continue;
if (memcmp(a->oid, p, a->oid_len) == 0) {
objp = a->node->child;
i -= a->oid_len;
p += a->oid_len;
ND_PRINT((ndo, "%s", a->prefix));
first = 1;
break;
}
}
}
for (; i-- > 0; p++) {
ND_TCHECK(*p);
o = (o << ASN_SHIFT7) + (*p & ~ASN_BIT8);
if (*p & ASN_LONGLEN)
continue;
/*
* first subitem encodes two items with
* 1st*OIDMUX+2nd
* (see X.690:1997 clause 8.19 for the details)
*/
if (first < 0) {
int s;
if (!ndo->ndo_nflag)
objp = mibroot;
first = 0;
s = o / OIDMUX;
if (s > 2) s = 2;
OBJ_PRINT(s, first);
o -= s * OIDMUX;
}
OBJ_PRINT(o, first);
if (--first < 0)
first = 0;
o = 0;
}
break;
}
case BE_INT:
ND_PRINT((ndo, "%d", elem->data.integer));
break;
case BE_UNS:
ND_PRINT((ndo, "%u", elem->data.uns));
break;
case BE_UNS64:
ND_PRINT((ndo, "%" PRIu64, elem->data.uns64));
break;
case BE_STR:
if (asn1_print_string(ndo, elem) == -1)
return -1;
break;
case BE_SEQ:
ND_PRINT((ndo, "Seq(%u)", elem->asnlen));
break;
case BE_INETADDR:
if (asnlen != ASNLEN_INETADDR)
ND_PRINT((ndo, "[inetaddr len!=%d]", ASNLEN_INETADDR));
p = (const u_char *)elem->data.raw;
ND_TCHECK2(*p, asnlen);
for (i = asnlen; i-- != 0; p++) {
ND_PRINT((ndo, (i == asnlen-1) ? "%u" : ".%u", *p));
}
break;
case BE_NOSUCHOBJECT:
case BE_NOSUCHINST:
case BE_ENDOFMIBVIEW:
ND_PRINT((ndo, "[%s]", Class[EXCEPTIONS].Id[elem->id]));
break;
case BE_PDU:
ND_PRINT((ndo, "%s(%u)", Class[CONTEXT].Id[elem->id], elem->asnlen));
break;
case BE_ANY:
ND_PRINT((ndo, "[BE_ANY!?]"));
break;
default:
ND_PRINT((ndo, "[be!?]"));
break;
}
return 0;
trunc:
ND_PRINT((ndo, "%s", tstr));
return -1;
}
#ifdef notdef
/*
* This is a brute force ASN.1 printer: recurses to dump an entire structure.
* This will work for any ASN.1 stream, not just an SNMP PDU.
*
* By adding newlines and spaces at the correct places, this would print in
* Rose-Normal-Form.
*
* This is not currently used.
*/
static void
asn1_decode(u_char *p, u_int length)
{
struct be elem;
int i = 0;
while (i >= 0 && length > 0) {
i = asn1_parse(ndo, p, length, &elem);
if (i >= 0) {
ND_PRINT((ndo, " "));
if (asn1_print(ndo, &elem) < 0)
return;
if (elem.type == BE_SEQ || elem.type == BE_PDU) {
ND_PRINT((ndo, " {"));
asn1_decode(elem.data.raw, elem.asnlen);
ND_PRINT((ndo, " }"));
}
length -= i;
p += i;
}
}
}
#endif
#ifdef USE_LIBSMI
struct smi2be {
SmiBasetype basetype;
int be;
};
static const struct smi2be smi2betab[] = {
{ SMI_BASETYPE_INTEGER32, BE_INT },
{ SMI_BASETYPE_OCTETSTRING, BE_STR },
{ SMI_BASETYPE_OCTETSTRING, BE_INETADDR },
{ SMI_BASETYPE_OBJECTIDENTIFIER, BE_OID },
{ SMI_BASETYPE_UNSIGNED32, BE_UNS },
{ SMI_BASETYPE_INTEGER64, BE_NONE },
{ SMI_BASETYPE_UNSIGNED64, BE_UNS64 },
{ SMI_BASETYPE_FLOAT32, BE_NONE },
{ SMI_BASETYPE_FLOAT64, BE_NONE },
{ SMI_BASETYPE_FLOAT128, BE_NONE },
{ SMI_BASETYPE_ENUM, BE_INT },
{ SMI_BASETYPE_BITS, BE_STR },
{ SMI_BASETYPE_UNKNOWN, BE_NONE }
};
static int
smi_decode_oid(netdissect_options *ndo,
struct be *elem, unsigned int *oid,
unsigned int oidsize, unsigned int *oidlen)
{
const u_char *p = (const u_char *)elem->data.raw;
uint32_t asnlen = elem->asnlen;
int o = 0, first = -1, i = asnlen;
unsigned int firstval;
for (*oidlen = 0; i-- > 0; p++) {
ND_TCHECK(*p);
o = (o << ASN_SHIFT7) + (*p & ~ASN_BIT8);
if (*p & ASN_LONGLEN)
continue;
/*
* first subitem encodes two items with 1st*OIDMUX+2nd
* (see X.690:1997 clause 8.19 for the details)
*/
if (first < 0) {
first = 0;
firstval = o / OIDMUX;
if (firstval > 2) firstval = 2;
o -= firstval * OIDMUX;
if (*oidlen < oidsize) {
oid[(*oidlen)++] = firstval;
}
}
if (*oidlen < oidsize) {
oid[(*oidlen)++] = o;
}
o = 0;
}
return 0;
trunc:
ND_PRINT((ndo, "%s", tstr));
return -1;
}
static int smi_check_type(SmiBasetype basetype, int be)
{
int i;
for (i = 0; smi2betab[i].basetype != SMI_BASETYPE_UNKNOWN; i++) {
if (smi2betab[i].basetype == basetype && smi2betab[i].be == be) {
return 1;
}
}
return 0;
}
static int smi_check_a_range(SmiType *smiType, SmiRange *smiRange,
struct be *elem)
{
int ok = 1;
switch (smiType->basetype) {
case SMI_BASETYPE_OBJECTIDENTIFIER:
case SMI_BASETYPE_OCTETSTRING:
if (smiRange->minValue.value.unsigned32
== smiRange->maxValue.value.unsigned32) {
ok = (elem->asnlen == smiRange->minValue.value.unsigned32);
} else {
ok = (elem->asnlen >= smiRange->minValue.value.unsigned32
&& elem->asnlen <= smiRange->maxValue.value.unsigned32);
}
break;
case SMI_BASETYPE_INTEGER32:
ok = (elem->data.integer >= smiRange->minValue.value.integer32
&& elem->data.integer <= smiRange->maxValue.value.integer32);
break;
case SMI_BASETYPE_UNSIGNED32:
ok = (elem->data.uns >= smiRange->minValue.value.unsigned32
&& elem->data.uns <= smiRange->maxValue.value.unsigned32);
break;
case SMI_BASETYPE_UNSIGNED64:
/* XXX */
break;
/* case SMI_BASETYPE_INTEGER64: SMIng */
/* case SMI_BASETYPE_FLOAT32: SMIng */
/* case SMI_BASETYPE_FLOAT64: SMIng */
/* case SMI_BASETYPE_FLOAT128: SMIng */
case SMI_BASETYPE_ENUM:
case SMI_BASETYPE_BITS:
case SMI_BASETYPE_UNKNOWN:
ok = 1;
break;
default:
ok = 0;
break;
}
return ok;
}
static int smi_check_range(SmiType *smiType, struct be *elem)
{
SmiRange *smiRange;
int ok = 1;
for (smiRange = smiGetFirstRange(smiType);
smiRange;
smiRange = smiGetNextRange(smiRange)) {
ok = smi_check_a_range(smiType, smiRange, elem);
if (ok) {
break;
}
}
if (ok) {
SmiType *parentType;
parentType = smiGetParentType(smiType);
if (parentType) {
ok = smi_check_range(parentType, elem);
}
}
return ok;
}
static SmiNode *
smi_print_variable(netdissect_options *ndo,
struct be *elem, int *status)
{
unsigned int oid[128], oidlen;
SmiNode *smiNode = NULL;
unsigned int i;
if (!nd_smi_module_loaded) {
*status = asn1_print(ndo, elem);
return NULL;
}
*status = smi_decode_oid(ndo, elem, oid, sizeof(oid) / sizeof(unsigned int),
&oidlen);
if (*status < 0)
return NULL;
smiNode = smiGetNodeByOID(oidlen, oid);
if (! smiNode) {
*status = asn1_print(ndo, elem);
return NULL;
}
if (ndo->ndo_vflag) {
ND_PRINT((ndo, "%s::", smiGetNodeModule(smiNode)->name));
}
ND_PRINT((ndo, "%s", smiNode->name));
if (smiNode->oidlen < oidlen) {
for (i = smiNode->oidlen; i < oidlen; i++) {
ND_PRINT((ndo, ".%u", oid[i]));
}
}
*status = 0;
return smiNode;
}
static int
smi_print_value(netdissect_options *ndo,
SmiNode *smiNode, u_short pduid, struct be *elem)
{
unsigned int i, oid[128], oidlen;
SmiType *smiType;
SmiNamedNumber *nn;
int done = 0;
if (! smiNode || ! (smiNode->nodekind
& (SMI_NODEKIND_SCALAR | SMI_NODEKIND_COLUMN))) {
return asn1_print(ndo, elem);
}
if (elem->type == BE_NOSUCHOBJECT
|| elem->type == BE_NOSUCHINST
|| elem->type == BE_ENDOFMIBVIEW) {
return asn1_print(ndo, elem);
}
if (NOTIFY_CLASS(pduid) && smiNode->access < SMI_ACCESS_NOTIFY) {
ND_PRINT((ndo, "[notNotifyable]"));
}
if (READ_CLASS(pduid) && smiNode->access < SMI_ACCESS_READ_ONLY) {
ND_PRINT((ndo, "[notReadable]"));
}
if (WRITE_CLASS(pduid) && smiNode->access < SMI_ACCESS_READ_WRITE) {
ND_PRINT((ndo, "[notWritable]"));
}
if (RESPONSE_CLASS(pduid)
&& smiNode->access == SMI_ACCESS_NOT_ACCESSIBLE) {
ND_PRINT((ndo, "[noAccess]"));
}
smiType = smiGetNodeType(smiNode);
if (! smiType) {
return asn1_print(ndo, elem);
}
if (! smi_check_type(smiType->basetype, elem->type)) {
ND_PRINT((ndo, "[wrongType]"));
}
if (! smi_check_range(smiType, elem)) {
ND_PRINT((ndo, "[outOfRange]"));
}
/* resolve bits to named bits */
/* check whether instance identifier is valid */
/* apply display hints (integer, octetstring) */
/* convert instance identifier to index type values */
switch (elem->type) {
case BE_OID:
if (smiType->basetype == SMI_BASETYPE_BITS) {
/* print bit labels */
} else {
if (nd_smi_module_loaded &&
smi_decode_oid(ndo, elem, oid,
sizeof(oid)/sizeof(unsigned int),
&oidlen) == 0) {
smiNode = smiGetNodeByOID(oidlen, oid);
if (smiNode) {
if (ndo->ndo_vflag) {
ND_PRINT((ndo, "%s::", smiGetNodeModule(smiNode)->name));
}
ND_PRINT((ndo, "%s", smiNode->name));
if (smiNode->oidlen < oidlen) {
for (i = smiNode->oidlen;
i < oidlen; i++) {
ND_PRINT((ndo, ".%u", oid[i]));
}
}
done++;
}
}
}
break;
case BE_INT:
if (smiType->basetype == SMI_BASETYPE_ENUM) {
for (nn = smiGetFirstNamedNumber(smiType);
nn;
nn = smiGetNextNamedNumber(nn)) {
if (nn->value.value.integer32
== elem->data.integer) {
ND_PRINT((ndo, "%s", nn->name));
ND_PRINT((ndo, "(%d)", elem->data.integer));
done++;
break;
}
}
}
break;
}
if (! done) {
return asn1_print(ndo, elem);
}
return 0;
}
#endif
/*
* General SNMP header
* SEQUENCE {
* version INTEGER {version-1(0)},
* community OCTET STRING,
* data ANY -- PDUs
* }
* PDUs for all but Trap: (see rfc1157 from page 15 on)
* SEQUENCE {
* request-id INTEGER,
* error-status INTEGER,
* error-index INTEGER,
* varbindlist SEQUENCE OF
* SEQUENCE {
* name ObjectName,
* value ObjectValue
* }
* }
* PDU for Trap:
* SEQUENCE {
* enterprise OBJECT IDENTIFIER,
* agent-addr NetworkAddress,
* generic-trap INTEGER,
* specific-trap INTEGER,
* time-stamp TimeTicks,
* varbindlist SEQUENCE OF
* SEQUENCE {
* name ObjectName,
* value ObjectValue
* }
* }
*/
/*
* Decode SNMP varBind
*/
static void
varbind_print(netdissect_options *ndo,
u_short pduid, const u_char *np, u_int length)
{
struct be elem;
int count = 0, ind;
#ifdef USE_LIBSMI
SmiNode *smiNode = NULL;
#endif
int status;
/* Sequence of varBind */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_SEQ) {
ND_PRINT((ndo, "[!SEQ of varbind]"));
asn1_print(ndo, &elem);
return;
}
if ((u_int)count < length)
ND_PRINT((ndo, "[%d extra after SEQ of varbind]", length - count));
/* descend */
length = elem.asnlen;
np = (const u_char *)elem.data.raw;
for (ind = 1; length > 0; ind++) {
const u_char *vbend;
u_int vblength;
ND_PRINT((ndo, " "));
/* Sequence */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_SEQ) {
ND_PRINT((ndo, "[!varbind]"));
asn1_print(ndo, &elem);
return;
}
vbend = np + count;
vblength = length - count;
/* descend */
length = elem.asnlen;
np = (const u_char *)elem.data.raw;
/* objName (OID) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_OID) {
ND_PRINT((ndo, "[objName!=OID]"));
asn1_print(ndo, &elem);
return;
}
#ifdef USE_LIBSMI
smiNode = smi_print_variable(ndo, &elem, &status);
#else
status = asn1_print(ndo, &elem);
#endif
if (status < 0)
return;
length -= count;
np += count;
if (pduid != GETREQ && pduid != GETNEXTREQ
&& pduid != GETBULKREQ)
ND_PRINT((ndo, "="));
/* objVal (ANY) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (pduid == GETREQ || pduid == GETNEXTREQ
|| pduid == GETBULKREQ) {
if (elem.type != BE_NULL) {
ND_PRINT((ndo, "[objVal!=NULL]"));
if (asn1_print(ndo, &elem) < 0)
return;
}
} else {
if (elem.type != BE_NULL) {
#ifdef USE_LIBSMI
status = smi_print_value(ndo, smiNode, pduid, &elem);
#else
status = asn1_print(ndo, &elem);
#endif
}
if (status < 0)
return;
}
length = vblength;
np = vbend;
}
}
/*
* Decode SNMP PDUs: GetRequest, GetNextRequest, GetResponse, SetRequest,
* GetBulk, Inform, V2Trap, and Report
*/
static void
snmppdu_print(netdissect_options *ndo,
u_short pduid, const u_char *np, u_int length)
{
struct be elem;
int count = 0, error_status;
/* reqId (Integer) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_INT) {
ND_PRINT((ndo, "[reqId!=INT]"));
asn1_print(ndo, &elem);
return;
}
if (ndo->ndo_vflag)
ND_PRINT((ndo, "R=%d ", elem.data.integer));
length -= count;
np += count;
/* errorStatus (Integer) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_INT) {
ND_PRINT((ndo, "[errorStatus!=INT]"));
asn1_print(ndo, &elem);
return;
}
error_status = 0;
if ((pduid == GETREQ || pduid == GETNEXTREQ || pduid == SETREQ
|| pduid == INFORMREQ || pduid == V2TRAP || pduid == REPORT)
&& elem.data.integer != 0) {
char errbuf[20];
ND_PRINT((ndo, "[errorStatus(%s)!=0]",
DECODE_ErrorStatus(elem.data.integer)));
} else if (pduid == GETBULKREQ) {
ND_PRINT((ndo, " N=%d", elem.data.integer));
} else if (elem.data.integer != 0) {
char errbuf[20];
ND_PRINT((ndo, " %s", DECODE_ErrorStatus(elem.data.integer)));
error_status = elem.data.integer;
}
length -= count;
np += count;
/* errorIndex (Integer) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_INT) {
ND_PRINT((ndo, "[errorIndex!=INT]"));
asn1_print(ndo, &elem);
return;
}
if ((pduid == GETREQ || pduid == GETNEXTREQ || pduid == SETREQ
|| pduid == INFORMREQ || pduid == V2TRAP || pduid == REPORT)
&& elem.data.integer != 0)
ND_PRINT((ndo, "[errorIndex(%d)!=0]", elem.data.integer));
else if (pduid == GETBULKREQ)
ND_PRINT((ndo, " M=%d", elem.data.integer));
else if (elem.data.integer != 0) {
if (!error_status)
ND_PRINT((ndo, "[errorIndex(%d) w/o errorStatus]", elem.data.integer));
else
ND_PRINT((ndo, "@%d", elem.data.integer));
} else if (error_status) {
ND_PRINT((ndo, "[errorIndex==0]"));
}
length -= count;
np += count;
varbind_print(ndo, pduid, np, length);
return;
}
/*
* Decode SNMP Trap PDU
*/
static void
trappdu_print(netdissect_options *ndo,
const u_char *np, u_int length)
{
struct be elem;
int count = 0, generic;
ND_PRINT((ndo, " "));
/* enterprise (oid) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_OID) {
ND_PRINT((ndo, "[enterprise!=OID]"));
asn1_print(ndo, &elem);
return;
}
if (asn1_print(ndo, &elem) < 0)
return;
length -= count;
np += count;
ND_PRINT((ndo, " "));
/* agent-addr (inetaddr) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_INETADDR) {
ND_PRINT((ndo, "[agent-addr!=INETADDR]"));
asn1_print(ndo, &elem);
return;
}
if (asn1_print(ndo, &elem) < 0)
return;
length -= count;
np += count;
/* generic-trap (Integer) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_INT) {
ND_PRINT((ndo, "[generic-trap!=INT]"));
asn1_print(ndo, &elem);
return;
}
generic = elem.data.integer;
{
char buf[20];
ND_PRINT((ndo, " %s", DECODE_GenericTrap(generic)));
}
length -= count;
np += count;
/* specific-trap (Integer) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_INT) {
ND_PRINT((ndo, "[specific-trap!=INT]"));
asn1_print(ndo, &elem);
return;
}
if (generic != GT_ENTERPRISE) {
if (elem.data.integer != 0)
ND_PRINT((ndo, "[specific-trap(%d)!=0]", elem.data.integer));
} else
ND_PRINT((ndo, " s=%d", elem.data.integer));
length -= count;
np += count;
ND_PRINT((ndo, " "));
/* time-stamp (TimeTicks) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_UNS) { /* XXX */
ND_PRINT((ndo, "[time-stamp!=TIMETICKS]"));
asn1_print(ndo, &elem);
return;
}
if (asn1_print(ndo, &elem) < 0)
return;
length -= count;
np += count;
varbind_print(ndo, TRAP, np, length);
return;
}
/*
* Decode arbitrary SNMP PDUs.
*/
static void
pdu_print(netdissect_options *ndo,
const u_char *np, u_int length, int version)
{
struct be pdu;
int count = 0;
/* PDU (Context) */
if ((count = asn1_parse(ndo, np, length, &pdu)) < 0)
return;
if (pdu.type != BE_PDU) {
ND_PRINT((ndo, "[no PDU]"));
return;
}
if ((u_int)count < length)
ND_PRINT((ndo, "[%d extra after PDU]", length - count));
if (ndo->ndo_vflag) {
ND_PRINT((ndo, "{ "));
}
if (asn1_print(ndo, &pdu) < 0)
return;
ND_PRINT((ndo, " "));
/* descend into PDU */
length = pdu.asnlen;
np = (const u_char *)pdu.data.raw;
if (version == SNMP_VERSION_1 &&
(pdu.id == GETBULKREQ || pdu.id == INFORMREQ ||
pdu.id == V2TRAP || pdu.id == REPORT)) {
ND_PRINT((ndo, "[v2 PDU in v1 message]"));
return;
}
if (version == SNMP_VERSION_2 && pdu.id == TRAP) {
ND_PRINT((ndo, "[v1 PDU in v2 message]"));
return;
}
switch (pdu.id) {
case TRAP:
trappdu_print(ndo, np, length);
break;
case GETREQ:
case GETNEXTREQ:
case GETRESP:
case SETREQ:
case GETBULKREQ:
case INFORMREQ:
case V2TRAP:
case REPORT:
snmppdu_print(ndo, pdu.id, np, length);
break;
}
if (ndo->ndo_vflag) {
ND_PRINT((ndo, " } "));
}
}
/*
* Decode a scoped SNMP PDU.
*/
static void
scopedpdu_print(netdissect_options *ndo,
const u_char *np, u_int length, int version)
{
struct be elem;
int count = 0;
/* Sequence */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_SEQ) {
ND_PRINT((ndo, "[!scoped PDU]"));
asn1_print(ndo, &elem);
return;
}
length = elem.asnlen;
np = (const u_char *)elem.data.raw;
/* contextEngineID (OCTET STRING) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_STR) {
ND_PRINT((ndo, "[contextEngineID!=STR]"));
asn1_print(ndo, &elem);
return;
}
length -= count;
np += count;
ND_PRINT((ndo, "E="));
if (asn1_print_octets(ndo, &elem) == -1)
return;
ND_PRINT((ndo, " "));
/* contextName (OCTET STRING) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_STR) {
ND_PRINT((ndo, "[contextName!=STR]"));
asn1_print(ndo, &elem);
return;
}
length -= count;
np += count;
ND_PRINT((ndo, "C="));
if (asn1_print_string(ndo, &elem) == -1)
return;
ND_PRINT((ndo, " "));
pdu_print(ndo, np, length, version);
}
/*
* Decode SNMP Community Header (SNMPv1 and SNMPv2c)
*/
static void
community_print(netdissect_options *ndo,
const u_char *np, u_int length, int version)
{
struct be elem;
int count = 0;
/* Community (String) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_STR) {
ND_PRINT((ndo, "[comm!=STR]"));
asn1_print(ndo, &elem);
return;
}
/* default community */
if (!(elem.asnlen == sizeof(DEF_COMMUNITY) - 1 &&
strncmp((const char *)elem.data.str, DEF_COMMUNITY,
sizeof(DEF_COMMUNITY) - 1) == 0)) {
/* ! "public" */
ND_PRINT((ndo, "C="));
if (asn1_print_string(ndo, &elem) == -1)
return;
ND_PRINT((ndo, " "));
}
length -= count;
np += count;
pdu_print(ndo, np, length, version);
}
/*
* Decode SNMPv3 User-based Security Message Header (SNMPv3)
*/
static void
usm_print(netdissect_options *ndo,
const u_char *np, u_int length)
{
struct be elem;
int count = 0;
/* Sequence */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_SEQ) {
ND_PRINT((ndo, "[!usm]"));
asn1_print(ndo, &elem);
return;
}
length = elem.asnlen;
np = (const u_char *)elem.data.raw;
/* msgAuthoritativeEngineID (OCTET STRING) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_STR) {
ND_PRINT((ndo, "[msgAuthoritativeEngineID!=STR]"));
asn1_print(ndo, &elem);
return;
}
length -= count;
np += count;
/* msgAuthoritativeEngineBoots (INTEGER) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_INT) {
ND_PRINT((ndo, "[msgAuthoritativeEngineBoots!=INT]"));
asn1_print(ndo, &elem);
return;
}
if (ndo->ndo_vflag)
ND_PRINT((ndo, "B=%d ", elem.data.integer));
length -= count;
np += count;
/* msgAuthoritativeEngineTime (INTEGER) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_INT) {
ND_PRINT((ndo, "[msgAuthoritativeEngineTime!=INT]"));
asn1_print(ndo, &elem);
return;
}
if (ndo->ndo_vflag)
ND_PRINT((ndo, "T=%d ", elem.data.integer));
length -= count;
np += count;
/* msgUserName (OCTET STRING) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_STR) {
ND_PRINT((ndo, "[msgUserName!=STR]"));
asn1_print(ndo, &elem);
return;
}
length -= count;
np += count;
ND_PRINT((ndo, "U="));
if (asn1_print_string(ndo, &elem) == -1)
return;
ND_PRINT((ndo, " "));
/* msgAuthenticationParameters (OCTET STRING) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_STR) {
ND_PRINT((ndo, "[msgAuthenticationParameters!=STR]"));
asn1_print(ndo, &elem);
return;
}
length -= count;
np += count;
/* msgPrivacyParameters (OCTET STRING) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_STR) {
ND_PRINT((ndo, "[msgPrivacyParameters!=STR]"));
asn1_print(ndo, &elem);
return;
}
length -= count;
np += count;
if ((u_int)count < length)
ND_PRINT((ndo, "[%d extra after usm SEQ]", length - count));
}
/*
* Decode SNMPv3 Message Header (SNMPv3)
*/
static void
v3msg_print(netdissect_options *ndo,
const u_char *np, u_int length)
{
struct be elem;
int count = 0;
u_char flags;
int model;
const u_char *xnp = np;
int xlength = length;
/* Sequence */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_SEQ) {
ND_PRINT((ndo, "[!message]"));
asn1_print(ndo, &elem);
return;
}
length = elem.asnlen;
np = (const u_char *)elem.data.raw;
if (ndo->ndo_vflag) {
ND_PRINT((ndo, "{ "));
}
/* msgID (INTEGER) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_INT) {
ND_PRINT((ndo, "[msgID!=INT]"));
asn1_print(ndo, &elem);
return;
}
length -= count;
np += count;
/* msgMaxSize (INTEGER) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_INT) {
ND_PRINT((ndo, "[msgMaxSize!=INT]"));
asn1_print(ndo, &elem);
return;
}
length -= count;
np += count;
/* msgFlags (OCTET STRING) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_STR) {
ND_PRINT((ndo, "[msgFlags!=STR]"));
asn1_print(ndo, &elem);
return;
}
if (elem.asnlen != 1) {
ND_PRINT((ndo, "[msgFlags size %d]", elem.asnlen));
return;
}
flags = elem.data.str[0];
if (flags != 0x00 && flags != 0x01 && flags != 0x03
&& flags != 0x04 && flags != 0x05 && flags != 0x07) {
ND_PRINT((ndo, "[msgFlags=0x%02X]", flags));
return;
}
length -= count;
np += count;
ND_PRINT((ndo, "F=%s%s%s ",
flags & 0x01 ? "a" : "",
flags & 0x02 ? "p" : "",
flags & 0x04 ? "r" : ""));
/* msgSecurityModel (INTEGER) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_INT) {
ND_PRINT((ndo, "[msgSecurityModel!=INT]"));
asn1_print(ndo, &elem);
return;
}
model = elem.data.integer;
length -= count;
np += count;
if ((u_int)count < length)
ND_PRINT((ndo, "[%d extra after message SEQ]", length - count));
if (ndo->ndo_vflag) {
ND_PRINT((ndo, "} "));
}
if (model == 3) {
if (ndo->ndo_vflag) {
ND_PRINT((ndo, "{ USM "));
}
} else {
ND_PRINT((ndo, "[security model %d]", model));
return;
}
np = xnp + (np - xnp);
length = xlength - (np - xnp);
/* msgSecurityParameters (OCTET STRING) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_STR) {
ND_PRINT((ndo, "[msgSecurityParameters!=STR]"));
asn1_print(ndo, &elem);
return;
}
length -= count;
np += count;
if (model == 3) {
usm_print(ndo, elem.data.str, elem.asnlen);
if (ndo->ndo_vflag) {
ND_PRINT((ndo, "} "));
}
}
if (ndo->ndo_vflag) {
ND_PRINT((ndo, "{ ScopedPDU "));
}
scopedpdu_print(ndo, np, length, 3);
if (ndo->ndo_vflag) {
ND_PRINT((ndo, "} "));
}
}
/*
* Decode SNMP header and pass on to PDU printing routines
*/
void
snmp_print(netdissect_options *ndo,
const u_char *np, u_int length)
{
struct be elem;
int count = 0;
int version = 0;
ND_PRINT((ndo, " "));
/* initial Sequence */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_SEQ) {
ND_PRINT((ndo, "[!init SEQ]"));
asn1_print(ndo, &elem);
return;
}
if ((u_int)count < length)
ND_PRINT((ndo, "[%d extra after iSEQ]", length - count));
/* descend */
length = elem.asnlen;
np = (const u_char *)elem.data.raw;
/* Version (INTEGER) */
if ((count = asn1_parse(ndo, np, length, &elem)) < 0)
return;
if (elem.type != BE_INT) {
ND_PRINT((ndo, "[version!=INT]"));
asn1_print(ndo, &elem);
return;
}
switch (elem.data.integer) {
case SNMP_VERSION_1:
case SNMP_VERSION_2:
case SNMP_VERSION_3:
if (ndo->ndo_vflag)
ND_PRINT((ndo, "{ %s ", SnmpVersion[elem.data.integer]));
break;
default:
ND_PRINT((ndo, "SNMP [version = %d]", elem.data.integer));
return;
}
version = elem.data.integer;
length -= count;
np += count;
switch (version) {
case SNMP_VERSION_1:
case SNMP_VERSION_2:
community_print(ndo, np, length, version);
break;
case SNMP_VERSION_3:
v3msg_print(ndo, np, length);
break;
default:
ND_PRINT((ndo, "[version = %d]", elem.data.integer));
break;
}
if (ndo->ndo_vflag) {
ND_PRINT((ndo, "} "));
}
}