print-snmp.c

Windump3.6.2源代码

			if (elem.type != BE_NULL) {
				fputs("[objVal!=NULL]", stdout);
				asn1_print(&elem);
			}
		} else {
		        if (elem.type != BE_NULL) {
#ifdef LIBSMI
			        smi_print_value(smiNode, pduid, &elem);
				smiFreeNode(smiNode);
#else
				asn1_print(&elem);
#endif
			}
		}
		length = vblength;
		np = vbend;
	}
}

/*
 * Decode SNMP PDUs: GetRequest, GetNextRequest, GetResponse, SetRequest,
 * GetBulk, Inform, V2Trap, and Report
 */
static void
snmppdu_print(u_char 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[10];
		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[10];
		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;
	}
	asn1_print(&elem);
	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;
	}
	asn1_print(&elem);
	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[10];
		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;
	}
	asn1_print(&elem);
	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 (count < length)
		printf("[%d extra after PDU]", length - count);
	if (vflag) {
		fputs("{ ", stdout);
	}
	asn1_print(&pdu);
	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 (strncmp((char *)elem.data.str, DEF_COMMUNITY,
	    sizeof(DEF_COMMUNITY) - 1))
		/* ! "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 (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 (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;

	truncated = 0;

	/* truncated packet? */
	if (np + length > snapend) {
		truncated = 1;
		length = snapend - np;
	}

	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 (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);
	}
}