source: rtems-libbsd/freebsd/contrib/tcpdump/print-snmp.c @ 8440506

#include <machine/rtems-bsd-user-space.h>

/*
 * 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
 */

#ifndef lint
static const char rcsid[] _U_ =
    "@(#) $Header: /tcpdump/master/tcpdump/print-snmp.c,v 1.64 2005-05-06 07:56:53 guy Exp $ (LBL)";
#endif

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <tcpdump-stdinc.h>

#include <stdio.h>
#include <string.h>

#ifdef HAVE_SMI_H
#include <smi.h>
#endif

#include "interface.h"
#include "addrtoname.h"

#undef OPAQUE  /* defined in <wingdi.h> */

/*
 * Universal ASN.1 types
 * (we only care about the tag values for those allowed in the Internet SMI)
 */
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
 */
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
 */
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
 */
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
 */
const char *Private[] = {
        "P-0"
};

/*
 * error-status values for any SNMP PDU
 */
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
 */
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 */
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
 */
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.
 */
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.
 */
struct obj_abrev {
        const char *prefix;             /* prefix for this abrev */
        struct obj *node;               /* pointer into object table */
        const char *oid;                /* ASN.1 encoded OID */
} obj_abrev_list[] = {
#ifndef NO_ABREV_MIB
        /* .iso.org.dod.internet.mgmt.mib */
        { "",   &_mib_obj,              "\53\6\1\2\1" },
#endif
#ifndef NO_ABREV_ENTER
        /* .iso.org.dod.internet.private.enterprises */
        { "E:", &_enterprises_obj,      "\53\6\1\4\1" },
#endif
#ifndef NO_ABREV_EXPERI
        /* .iso.org.dod.internet.experimental */
        { "X:", &_experimental_obj,     "\53\6\1\3" },
#endif
#ifndef NO_ABBREV_SNMPMODS
        /* .iso.org.dod.internet.snmpV2.snmpModules */
        { "S:", &_snmpModules_obj,      "\53\6\1\6\3" },
#endif
        { 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) { \
                printf(suppressdot?"%s":".%s", objp->desc); \
                objp = objp->child; \
        } else \
                printf(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 {
        u_int32_t asnlen;
        union {
                caddr_t raw;
                int32_t integer;
                u_int32_t uns;
                const u_char *str;
                struct {
                        u_int32_t high;
                        u_int32_t low;
                } 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
 */
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(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) {
                fputs("[nothing to parse]", stdout);
                return -1;
        }
        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.
                 */
                for (id = 0; *p & ASN_BIT8; len--, hdr++, p++) {
                        if (len < 1) {
                                fputs("[Xtagfield?]", stdout);
                                return -1;
                        }
                        TCHECK(*p);
                        id = (id << 7) | (*p & ~ASN_BIT8);
                }
                if (len < 1) {
                        fputs("[Xtagfield?]", stdout);
                        return -1;
                }
                TCHECK(*p);
                elem->id = id = (id << 7) | *p;
                --len;
                ++hdr;
                ++p;
        }
        if (len < 1) {
                fputs("[no asnlen]", stdout);
                return -1;
        }
        TCHECK(*p);
        elem->asnlen = *p;
        p++; len--; hdr++;
        if (elem->asnlen & ASN_BIT8) {
                u_int32_t noct = elem->asnlen % ASN_BIT8;
                elem->asnlen = 0;
                if (len < noct) {
                        printf("[asnlen? %d<%d]", len, noct);
                        return -1;
                }
                TCHECK2(*p, noct);
                for (; noct-- > 0; len--, hdr++)
                        elem->asnlen = (elem->asnlen << ASN_SHIFT8) | *p++;
        }
        if (len < elem->asnlen) {
                printf("[len%d<asnlen%u]", len, elem->asnlen);
                return -1;
        }
        if (form >= sizeof(Form)/sizeof(Form[0])) {
                printf("[form?%d]", form);
                return -1;
        }
        if (class >= sizeof(Class)/sizeof(Class[0])) {
                printf("[class?%c/%d]", *Form[form], class);
                return -1;
        }
        if ((int)id >= Class[class].numIDs) {
                printf("[id?%c/%s/%d]", *Form[form], Class[class].name, id);
                return -1;
        }

        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;

                                TCHECK2(*p, elem->asnlen);
                                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 = (caddr_t)p;
                                break;

                        case ASN_NULL:
                                elem->type = BE_NULL;
                                elem->data.raw = NULL;
                                break;

                        default:
                                elem->type = BE_OCTET;
                                elem->data.raw = (caddr_t)p;
                                printf("[P/U/%s]",
                                        Class[class].Id[id]);
                                break;
                        }
                        break;

                case APPLICATION:
                        switch (id) {
                        case IPADDR:
                                elem->type = BE_INETADDR;
                                elem->data.raw = (caddr_t)p;
                                break;

                        case COUNTER:
                        case GAUGE:
                        case TIMETICKS: {
                                register u_int32_t data;
                                TCHECK2(*p, elem->asnlen);
                                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 u_int32_t high, low;
                                TCHECK2(*p, elem->asnlen);
                                elem->type = BE_UNS64;
                                high = 0, low = 0;
                                for (i = elem->asnlen; i-- > 0; p++) {
                                        high = (high << 8) |
                                            ((low & 0xFF000000) >> 24);
                                        low = (low << 8) | *p;
                                }
                                elem->data.uns64.high = high;
                                elem->data.uns64.low = low;
                                break;
                        }

                        default:
                                elem->type = BE_OCTET;
                                elem->data.raw = (caddr_t)p;
                                printf("[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:
                        printf("[P/%s/%s]",
                                Class[class].name, Class[class].Id[id]);
                        TCHECK2(*p, elem->asnlen);
                        elem->type = BE_OCTET;
                        elem->data.raw = (caddr_t)p;
                        break;
                }
                break;

        case CONSTRUCTED:
                switch (class) {
                case UNIVERSAL:
                        switch (id) {
                        case SEQUENCE:
                                elem->type = BE_SEQ;
                                elem->data.raw = (caddr_t)p;
                                break;

                        default:
                                elem->type = BE_OCTET;
                                elem->data.raw = (caddr_t)p;
                                printf("C/U/%s", Class[class].Id[id]);
                                break;
                        }
                        break;

                case CONTEXT:
                        elem->type = BE_PDU;
                        elem->data.raw = (caddr_t)p;
                        break;

                default:
                        elem->type = BE_OCTET;
                        elem->data.raw = (caddr_t)p;
                        printf("C/%s/%s",
                                Class[class].name, Class[class].Id[id]);
                        break;
                }
                break;
        }
        p += elem->asnlen;
        len -= elem->asnlen;
        return elem->asnlen + hdr;

trunc:
        fputs("[|snmp]", stdout);
        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(struct be *elem)
{
        u_char *p = (u_char *)elem->data.raw;
        u_int32_t asnlen = elem->asnlen;
        u_int32_t i;

        switch (elem->type) {

        case BE_OCTET:
                TCHECK2(*p, asnlen);
                for (i = asnlen; i-- > 0; p++)
                        printf("_%.2x", *p);
                break;

        case BE_NULL:
                break;

        case BE_OID: {
                int o = 0, first = -1, i = asnlen;

                if (!sflag && !nflag && asnlen > 2) {
                        struct obj_abrev *a = &obj_abrev_list[0];
                        size_t a_len = strlen(a->oid);
                        for (; a->node; a++) {
                                TCHECK2(*p, a_len);
                                if (memcmp(a->oid, (char *)p, a_len) == 0) {
                                        objp = a->node->child;
                                        i -= strlen(a->oid);
                                        p += strlen(a->oid);
                                        fputs(a->prefix, stdout);
                                        first = 1;
                                        break;
                                }
                        }
                }

                for (; !sflag && i-- > 0; p++) {
                        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 (!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:
                printf("%d", elem->data.integer);
                break;

        case BE_UNS:
                printf("%u", elem->data.uns);
                break;

        case BE_UNS64: {        /* idea borrowed from by Marshall Rose */
                double d;
                int j, carry;
                char *cpf, *cpl, last[6], first[30];
                if (elem->data.uns64.high == 0) {
                        printf("%u", elem->data.uns64.low);
                        break;
                }
                d = elem->data.uns64.high * 4294967296.0;       /* 2^32 */
                if (elem->data.uns64.high <= 0x1fffff) {
                        d += elem->data.uns64.low;
#if 0 /*is looks illegal, but what is the intention?*/
                        printf("%.f", d);
#else
                        printf("%f", d);
#endif
                        break;
                }
                d += (elem->data.uns64.low & 0xfffff000);
#if 0 /*is looks illegal, but what is the intention?*/
                snprintf(first, sizeof(first), "%.f", d);
#else
                snprintf(first, sizeof(first), "%f", d);
#endif
                snprintf(last, sizeof(last), "%5.5d",
                    elem->data.uns64.low & 0xfff);
                for (carry = 0, cpf = first+strlen(first)-1, cpl = last+4;
                     cpl >= last;
                     cpf--, cpl--) {
                        j = carry + (*cpf - '0') + (*cpl - '0');
                        if (j > 9) {
                                j -= 10;
                                carry = 1;
                        } else {
                                carry = 0;
                        }
                        *cpf = j + '0';
                }
                fputs(first, stdout);
                break;
        }

        case BE_STR: {
                register int printable = 1, first = 1;
                const u_char *p = elem->data.str;
                TCHECK2(*p, asnlen);
                for (i = asnlen; printable && i-- > 0; p++)
                        printable = isprint(*p) || isspace(*p);
                p = elem->data.str;
                if (printable) {
                        putchar('"');
                        if (fn_printn(p, asnlen, snapend)) {
                                putchar('"');
                                goto trunc;
                        }
                        putchar('"');
                } else
                        for (i = asnlen; i-- > 0; p++) {
                                printf(first ? "%.2x" : "_%.2x", *p);
                                first = 0;
                        }
                break;
        }

        case BE_SEQ:
                printf("Seq(%u)", elem->asnlen);
                break;

        case BE_INETADDR:
                if (asnlen != ASNLEN_INETADDR)
                        printf("[inetaddr len!=%d]", ASNLEN_INETADDR);
                TCHECK2(*p, asnlen);
                for (i = asnlen; i-- != 0; p++) {
                        printf((i == asnlen-1) ? "%u" : ".%u", *p);
                }
                break;

        case BE_NOSUCHOBJECT:
        case BE_NOSUCHINST:
        case BE_ENDOFMIBVIEW:
                printf("[%s]", Class[EXCEPTIONS].Id[elem->id]);
                break;

        case BE_PDU:
                printf("%s(%u)",
                        Class[CONTEXT].Id[elem->id], elem->asnlen);
                break;

        case BE_ANY:
                fputs("[BE_ANY!?]", stdout);
                break;

        default:
                fputs("[be!?]", stdout);
                break;
        }
        return 0;

trunc:
        fputs("[|snmp]", stdout);
        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(p, length, &elem);
                if (i >= 0) {
                        fputs(" ", stdout);
                        if (asn1_print(&elem) < 0)
                                return;
                        if (elem.type == BE_SEQ || elem.type == BE_PDU) {
                                fputs(" {", stdout);
                                asn1_decode(elem.data.raw, elem.asnlen);
                                fputs(" }", stdout);
                        }
                        length -= i;
                        p += i;
                }
        }
}
#endif

#ifdef LIBSMI

struct smi2be {
    SmiBasetype basetype;
    int be;
};

static 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(struct be *elem, unsigned int *oid,
               unsigned int oidsize, unsigned int *oidlen)
{
        u_char *p = (u_char *)elem->data.raw;
        u_int32_t asnlen = elem->asnlen;
        int o = 0, first = -1, i = asnlen;

        for (*oidlen = 0; sflag && i-- > 0; p++) {
                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;
                        if (*oidlen < oidsize) {
                            oid[*oidlen] = o / OIDMUX;
                            if (oid[*oidlen] > 2) oid[*oidlen] = 2;
                        }
                        o -= oid[*oidlen] * OIDMUX;
                        if (*oidlen < oidsize) (*oidlen)++;
                }
                if (*oidlen < oidsize) {
                        oid[(*oidlen)++] = o;
                }
                o = 0;
        }
        return 0;

trunc:
        fputs("[|snmp]", stdout);
        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(struct be *elem, int *status)
{
        unsigned int oid[128], oidlen;
        SmiNode *smiNode = NULL;
        unsigned int i;

        *status = smi_decode_oid(elem, oid, sizeof(oid)/sizeof(unsigned int),
            &oidlen);
        if (*status < 0)
                return NULL;
        smiNode = smiGetNodeByOID(oidlen, oid);
        if (! smiNode) {
                *status = asn1_print(elem);
                return NULL;
        }
        if (vflag) {
                fputs(smiGetNodeModule(smiNode)->name, stdout);
                fputs("::", stdout);
        }
        fputs(smiNode->name, stdout);
        if (smiNode->oidlen < oidlen) {
                for (i = smiNode->oidlen; i < oidlen; i++) {
                        printf(".%u", oid[i]);
                }
        }
        *status = 0;
        return smiNode;
}

static int
smi_print_value(SmiNode *smiNode, u_char 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(elem);
        }

        if (elem->type == BE_NOSUCHOBJECT
            || elem->type == BE_NOSUCHINST
            || elem->type == BE_ENDOFMIBVIEW) {
            return asn1_print(elem);
        }

        if (NOTIFY_CLASS(pduid) && smiNode->access < SMI_ACCESS_NOTIFY) {
            fputs("[notNotifyable]", stdout);
        }

        if (READ_CLASS(pduid) && smiNode->access < SMI_ACCESS_READ_ONLY) {
            fputs("[notReadable]", stdout);
        }

        if (WRITE_CLASS(pduid) && smiNode->access < SMI_ACCESS_READ_WRITE) {
            fputs("[notWritable]", stdout);
        }

        if (RESPONSE_CLASS(pduid)
            && smiNode->access == SMI_ACCESS_NOT_ACCESSIBLE) {
            fputs("[noAccess]", stdout);
        }

        smiType = smiGetNodeType(smiNode);
        if (! smiType) {
            return asn1_print(elem);
        }

        if (! smi_check_type(smiType->basetype, elem->type)) {
            fputs("[wrongType]", stdout);
        }

        if (! smi_check_range(smiType, elem)) {
            fputs("[outOfRange]", stdout);
        }

        /* 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 {
                        smi_decode_oid(elem, oid,
                                       sizeof(oid)/sizeof(unsigned int),
                                       &oidlen);
                        smiNode = smiGetNodeByOID(oidlen, oid);
                        if (smiNode) {
                                if (vflag) {
                                        fputs(smiGetNodeModule(smiNode)->name, stdout);
                                        fputs("::", stdout);
                                }
                                fputs(smiNode->name, stdout);
                                if (smiNode->oidlen < oidlen) {
                                        for (i = smiNode->oidlen;
                                             i < oidlen; i++) {
                                                printf(".%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) {
                                         fputs(nn->name, stdout);
                                         printf("(%d)", elem->data.integer);
                                         done++;
                                         break;
                                }
                        }
                }
                break;
        }

        if (! done) {
                return asn1_print(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(u_char pduid, const u_char *np, u_int length)
{
        struct be elem;
        int count = 0, ind;
#ifdef LIBSMI
        SmiNode *smiNode = NULL;
#endif
        int status;

        /* Sequence of varBind */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_SEQ) {
                fputs("[!SEQ of varbind]", stdout);
                asn1_print(&elem);
                return;
        }
        if ((u_int)count < length)
                printf("[%d extra after SEQ of varbind]", length - count);
        /* descend */
        length = elem.asnlen;
        np = (u_char *)elem.data.raw;

        for (ind = 1; length > 0; ind++) {
                const u_char *vbend;
                u_int vblength;

                fputs(" ", stdout);

                /* Sequence */
                if ((count = asn1_parse(np, length, &elem)) < 0)
                        return;
                if (elem.type != BE_SEQ) {
                        fputs("[!varbind]", stdout);
                        asn1_print(&elem);
                        return;
                }
                vbend = np + count;
                vblength = length - count;
                /* descend */
                length = elem.asnlen;
                np = (u_char *)elem.data.raw;

                /* objName (OID) */
                if ((count = asn1_parse(np, length, &elem)) < 0)
                        return;
                if (elem.type != BE_OID) {
                        fputs("[objName!=OID]", stdout);
                        asn1_print(&elem);
                        return;
                }
#ifdef LIBSMI
                smiNode = smi_print_variable(&elem, &status);
#else
                status = asn1_print(&elem);
#endif
                if (status < 0)
                        return;
                length -= count;
                np += count;

                if (pduid != GETREQ && pduid != GETNEXTREQ
                    && pduid != GETBULKREQ)
                        fputs("=", stdout);

                /* objVal (ANY) */
                if ((count = asn1_parse(np, length, &elem)) < 0)
                        return;
                if (pduid == GETREQ || pduid == GETNEXTREQ
                    || pduid == GETBULKREQ) {
                        if (elem.type != BE_NULL) {
                                fputs("[objVal!=NULL]", stdout);
                                if (asn1_print(&elem) < 0)
                                        return;
                        }
                } else {
                        if (elem.type != BE_NULL) {
#ifdef LIBSMI
                                status = smi_print_value(smiNode, pduid, &elem);
#else
                                status = asn1_print(&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(u_short pduid, const u_char *np, u_int length)
{
        struct be elem;
        int count = 0, error;

        /* reqId (Integer) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_INT) {
                fputs("[reqId!=INT]", stdout);
                asn1_print(&elem);
                return;
        }
        if (vflag)
                printf("R=%d ", elem.data.integer);
        length -= count;
        np += count;

        /* errorStatus (Integer) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_INT) {
                fputs("[errorStatus!=INT]", stdout);
                asn1_print(&elem);
                return;
        }
        error = 0;
        if ((pduid == GETREQ || pduid == GETNEXTREQ || pduid == SETREQ
            || pduid == INFORMREQ || pduid == V2TRAP || pduid == REPORT)
            && elem.data.integer != 0) {
                char errbuf[20];
                printf("[errorStatus(%s)!=0]",
                        DECODE_ErrorStatus(elem.data.integer));
        } else if (pduid == GETBULKREQ) {
                printf(" N=%d", elem.data.integer);
        } else if (elem.data.integer != 0) {
                char errbuf[20];
                printf(" %s", DECODE_ErrorStatus(elem.data.integer));
                error = elem.data.integer;
        }
        length -= count;
        np += count;

        /* errorIndex (Integer) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_INT) {
                fputs("[errorIndex!=INT]", stdout);
                asn1_print(&elem);
                return;
        }
        if ((pduid == GETREQ || pduid == GETNEXTREQ || pduid == SETREQ
            || pduid == INFORMREQ || pduid == V2TRAP || pduid == REPORT)
            && elem.data.integer != 0)
                printf("[errorIndex(%d)!=0]", elem.data.integer);
        else if (pduid == GETBULKREQ)
                printf(" M=%d", elem.data.integer);
        else if (elem.data.integer != 0) {
                if (!error)
                        printf("[errorIndex(%d) w/o errorStatus]",
                                elem.data.integer);
                else {
                        printf("@%d", elem.data.integer);
                        error = elem.data.integer;
                }
        } else if (error) {
                fputs("[errorIndex==0]", stdout);
                error = 0;
        }
        length -= count;
        np += count;

        varbind_print(pduid, np, length);
        return;
}

/*
 * Decode SNMP Trap PDU
 */
static void
trappdu_print(const u_char *np, u_int length)
{
        struct be elem;
        int count = 0, generic;

        putchar(' ');

        /* enterprise (oid) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_OID) {
                fputs("[enterprise!=OID]", stdout);
                asn1_print(&elem);
                return;
        }
        if (asn1_print(&elem) < 0)
                return;
        length -= count;
        np += count;

        putchar(' ');

        /* agent-addr (inetaddr) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_INETADDR) {
                fputs("[agent-addr!=INETADDR]", stdout);
                asn1_print(&elem);
                return;
        }
        if (asn1_print(&elem) < 0)
                return;
        length -= count;
        np += count;

        /* generic-trap (Integer) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_INT) {
                fputs("[generic-trap!=INT]", stdout);
                asn1_print(&elem);
                return;
        }
        generic = elem.data.integer;
        {
                char buf[20];
                printf(" %s", DECODE_GenericTrap(generic));
        }
        length -= count;
        np += count;

        /* specific-trap (Integer) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_INT) {
                fputs("[specific-trap!=INT]", stdout);
                asn1_print(&elem);
                return;
        }
        if (generic != GT_ENTERPRISE) {
                if (elem.data.integer != 0)
                        printf("[specific-trap(%d)!=0]", elem.data.integer);
        } else
                printf(" s=%d", elem.data.integer);
        length -= count;
        np += count;

        putchar(' ');

        /* time-stamp (TimeTicks) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_UNS) {                      /* XXX */
                fputs("[time-stamp!=TIMETICKS]", stdout);
                asn1_print(&elem);
                return;
        }
        if (asn1_print(&elem) < 0)
                return;
        length -= count;
        np += count;

        varbind_print (TRAP, np, length);
        return;
}

/*
 * Decode arbitrary SNMP PDUs.
 */
static void
pdu_print(const u_char *np, u_int length, int version)
{
        struct be pdu;
        int count = 0;

        /* PDU (Context) */
        if ((count = asn1_parse(np, length, &pdu)) < 0)
                return;
        if (pdu.type != BE_PDU) {
                fputs("[no PDU]", stdout);
                return;
        }
        if ((u_int)count < length)
                printf("[%d extra after PDU]", length - count);
        if (vflag) {
                fputs("{ ", stdout);
        }
        if (asn1_print(&pdu) < 0)
                return;
        fputs(" ", stdout);
        /* descend into PDU */
        length = pdu.asnlen;
        np = (u_char *)pdu.data.raw;

        if (version == SNMP_VERSION_1 &&
            (pdu.id == GETBULKREQ || pdu.id == INFORMREQ ||
             pdu.id == V2TRAP || pdu.id == REPORT)) {
                printf("[v2 PDU in v1 message]");
                return;
        }

        if (version == SNMP_VERSION_2 && pdu.id == TRAP) {
                printf("[v1 PDU in v2 message]");
                return;
        }

        switch (pdu.id) {
        case TRAP:
                trappdu_print(np, length);
                break;
        case GETREQ:
        case GETNEXTREQ:
        case GETRESP:
        case SETREQ:
        case GETBULKREQ:
        case INFORMREQ:
        case V2TRAP:
        case REPORT:
                snmppdu_print(pdu.id, np, length);
                break;
        }

        if (vflag) {
                fputs(" } ", stdout);
        }
}

/*
 * Decode a scoped SNMP PDU.
 */
static void
scopedpdu_print(const u_char *np, u_int length, int version)
{
        struct be elem;
        int i, count = 0;

        /* Sequence */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_SEQ) {
                fputs("[!scoped PDU]", stdout);
                asn1_print(&elem);
                return;
        }
        length = elem.asnlen;
        np = (u_char *)elem.data.raw;

        /* contextEngineID (OCTET STRING) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_STR) {
                fputs("[contextEngineID!=STR]", stdout);
                asn1_print(&elem);
                return;
        }
        length -= count;
        np += count;

        fputs("E= ", stdout);
        for (i = 0; i < (int)elem.asnlen; i++) {
            printf("0x%02X", elem.data.str[i]);
        }
        fputs(" ", stdout);

        /* contextName (OCTET STRING) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_STR) {
                fputs("[contextName!=STR]", stdout);
                asn1_print(&elem);
                return;
        }
        length -= count;
        np += count;

        printf("C=%.*s ", (int)elem.asnlen, elem.data.str);

        pdu_print(np, length, version);
}

/*
 * Decode SNMP Community Header (SNMPv1 and SNMPv2c)
 */
static void
community_print(const u_char *np, u_int length, int version)
{
        struct be elem;
        int count = 0;

        /* Community (String) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_STR) {
                fputs("[comm!=STR]", stdout);
                asn1_print(&elem);
                return;
        }
        /* default community */
        if (!(elem.asnlen == sizeof(DEF_COMMUNITY) - 1 &&
            strncmp((char *)elem.data.str, DEF_COMMUNITY,
                    sizeof(DEF_COMMUNITY) - 1) == 0))
                /* ! "public" */
                printf("C=%.*s ", (int)elem.asnlen, elem.data.str);
        length -= count;
        np += count;

        pdu_print(np, length, version);
}

/*
 * Decode SNMPv3 User-based Security Message Header (SNMPv3)
 */
static void
usm_print(const u_char *np, u_int length)
{
        struct be elem;
        int count = 0;

        /* Sequence */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_SEQ) {
                fputs("[!usm]", stdout);
                asn1_print(&elem);
                return;
        }
        length = elem.asnlen;
        np = (u_char *)elem.data.raw;

        /* msgAuthoritativeEngineID (OCTET STRING) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_STR) {
                fputs("[msgAuthoritativeEngineID!=STR]", stdout);
                asn1_print(&elem);
                return;
        }
        length -= count;
        np += count;

        /* msgAuthoritativeEngineBoots (INTEGER) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_INT) {
                fputs("[msgAuthoritativeEngineBoots!=INT]", stdout);
                asn1_print(&elem);
                return;
        }
        if (vflag)
                printf("B=%d ", elem.data.integer);
        length -= count;
        np += count;

        /* msgAuthoritativeEngineTime (INTEGER) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_INT) {
                fputs("[msgAuthoritativeEngineTime!=INT]", stdout);
                asn1_print(&elem);
                return;
        }
        if (vflag)
                printf("T=%d ", elem.data.integer);
        length -= count;
        np += count;

        /* msgUserName (OCTET STRING) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_STR) {
                fputs("[msgUserName!=STR]", stdout);
                asn1_print(&elem);
                return;
        }
        length -= count;
        np += count;

        printf("U=%.*s ", (int)elem.asnlen, elem.data.str);

        /* msgAuthenticationParameters (OCTET STRING) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_STR) {
                fputs("[msgAuthenticationParameters!=STR]", stdout);
                asn1_print(&elem);
                return;
        }
        length -= count;
        np += count;

        /* msgPrivacyParameters (OCTET STRING) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_STR) {
                fputs("[msgPrivacyParameters!=STR]", stdout);
                asn1_print(&elem);
                return;
        }
        length -= count;
        np += count;

        if ((u_int)count < length)
                printf("[%d extra after usm SEQ]", length - count);
}

/*
 * Decode SNMPv3 Message Header (SNMPv3)
 */
static void
v3msg_print(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(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_SEQ) {
                fputs("[!message]", stdout);
                asn1_print(&elem);
                return;
        }
        length = elem.asnlen;
        np = (u_char *)elem.data.raw;

        if (vflag) {
                fputs("{ ", stdout);
        }

        /* msgID (INTEGER) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_INT) {
                fputs("[msgID!=INT]", stdout);
                asn1_print(&elem);
                return;
        }
        length -= count;
        np += count;

        /* msgMaxSize (INTEGER) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_INT) {
                fputs("[msgMaxSize!=INT]", stdout);
                asn1_print(&elem);
                return;
        }
        length -= count;
        np += count;

        /* msgFlags (OCTET STRING) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_STR) {
                fputs("[msgFlags!=STR]", stdout);
                asn1_print(&elem);
                return;
        }
        if (elem.asnlen != 1) {
                printf("[msgFlags size %d]", elem.asnlen);
                return;
        }
        flags = elem.data.str[0];
        if (flags != 0x00 && flags != 0x01 && flags != 0x03
            && flags != 0x04 && flags != 0x05 && flags != 0x07) {
                printf("[msgFlags=0x%02X]", flags);
                return;
        }
        length -= count;
        np += count;

        fputs("F=", stdout);
        if (flags & 0x01) fputs("a", stdout);
        if (flags & 0x02) fputs("p", stdout);
        if (flags & 0x04) fputs("r", stdout);
        fputs(" ", stdout);

        /* msgSecurityModel (INTEGER) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_INT) {
                fputs("[msgSecurityModel!=INT]", stdout);
                asn1_print(&elem);
                return;
        }
        model = elem.data.integer;
        length -= count;
        np += count;

        if ((u_int)count < length)
                printf("[%d extra after message SEQ]", length - count);

        if (vflag) {
                fputs("} ", stdout);
        }

        if (model == 3) {
            if (vflag) {
                fputs("{ USM ", stdout);
            }
        } else {
            printf("[security model %d]", model);
            return;
        }

        np = xnp + (np - xnp);
        length = xlength - (np - xnp);

        /* msgSecurityParameters (OCTET STRING) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_STR) {
                fputs("[msgSecurityParameters!=STR]", stdout);
                asn1_print(&elem);
                return;
        }
        length -= count;
        np += count;

        if (model == 3) {
            usm_print(elem.data.str, elem.asnlen);
            if (vflag) {
                fputs("} ", stdout);
            }
        }

        if (vflag) {
            fputs("{ ScopedPDU ", stdout);
        }

        scopedpdu_print(np, length, 3);

        if (vflag) {
                fputs("} ", stdout);
        }
}

/*
 * Decode SNMP header and pass on to PDU printing routines
 */
void
snmp_print(const u_char *np, u_int length)
{
        struct be elem;
        int count = 0;
        int version = 0;

        putchar(' ');

        /* initial Sequence */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_SEQ) {
                fputs("[!init SEQ]", stdout);
                asn1_print(&elem);
                return;
        }
        if ((u_int)count < length)
                printf("[%d extra after iSEQ]", length - count);
        /* descend */
        length = elem.asnlen;
        np = (u_char *)elem.data.raw;

        /* Version (INTEGER) */
        if ((count = asn1_parse(np, length, &elem)) < 0)
                return;
        if (elem.type != BE_INT) {
                fputs("[version!=INT]", stdout);
                asn1_print(&elem);
                return;
        }

        switch (elem.data.integer) {
        case SNMP_VERSION_1:
        case SNMP_VERSION_2:
        case SNMP_VERSION_3:
                if (vflag)
                        printf("{ %s ", SnmpVersion[elem.data.integer]);
                break;
        default:
                printf("[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(np, length, version);
                break;
        case SNMP_VERSION_3:
                v3msg_print(np, length);
                break;
        default:
                printf("[version = %d]", elem.data.integer);
                break;
        }

        if (vflag) {
                fputs("} ", stdout);
        }
}