int SnmpMessage::load(const Pdu &cpdu,
const OctetStr &community,
const snmp_version version,
const OctetStr* engine_id,
const OctetStr* security_name,
const int security_model)
{
int status;
const Pdu *pdu = &cpdu;
Pdu temppdu;
// make sure pdu is valid
if ( !pdu->valid())
return SNMP_CLASS_INVALID_PDU;
// create a raw pdu
snmp_pdu *raw_pdu;
raw_pdu = snmp_pdu_create( (int) pdu->get_type());
Oid enterprise;
// load it up
raw_pdu->reqid = pdu->get_request_id();
#ifdef _SNMPv3
raw_pdu->msgid = pdu->get_message_id();
#endif
raw_pdu->errstat= (unsigned long) pdu->get_error_status();
raw_pdu->errindex= (unsigned long) pdu->get_error_index();
// if its a V1 trap then load up other values
// for v2, use normal pdu format
if (raw_pdu->command == sNMP_PDU_V1TRAP)
{
// DON'T forget about the v1 trap agent address (changed by Frank Fock)
GenAddress gen_addr;
IpAddress ip_addr;
int addr_set = FALSE;
if (pdu->get_v1_trap_address(gen_addr))
{
/* User did set the v1 trap address */
if ((gen_addr.get_type() != Address::type_ip) &&
(gen_addr.get_type() != Address::type_udp) )
{
LOG_BEGIN(ERROR_LOG | 4);
LOG("SNMPMessage: Bad v1 trap address type in pdu");
LOG(gen_addr.get_type());
LOG_END;
snmp_free_pdu( raw_pdu);
return SNMP_CLASS_INVALID_PDU;
}
ip_addr = gen_addr;
if (!ip_addr.valid())
{
LOG_BEGIN(ERROR_LOG | 1);
LOG("SNMPMessage: Copied v1 trap address not valid");
LOG_END;
snmp_free_pdu( raw_pdu);
return SNMP_CLASS_RESOURCE_UNAVAIL;
}
addr_set = TRUE;
}
else
{
/* User did not set the v1 trap address */
char addrString[256];
if (gethostname(addrString, 255) == 0)
{
ip_addr = addrString;
addr_set = TRUE;
}
}
struct sockaddr_in agent_addr; // agent address socket struct
// prepare the agent address
memset(&agent_addr, 0, sizeof(agent_addr));
agent_addr.sin_family = AF_INET;
if (addr_set)
{
agent_addr.sin_addr.s_addr
= inet_addr(((IpAddress &)ip_addr).IpAddress::get_printable());
LOG_BEGIN(INFO_LOG | 7);
LOG("SNMPMessage: Setting v1 trap address");
LOG(((IpAddress &)ip_addr).IpAddress::get_printable());
LOG_END;
}
raw_pdu->agent_addr = agent_addr;
//-----[ compute generic trap value ]-------------------------------
// determine the generic value
// 0 - cold start
// 1 - warm start
// 2 - link down
// 3 - link up
// 4 - authentication failure
// 5 - egpneighborloss
// 6 - enterprise specific
Oid trapid;
pdu->get_notify_id( trapid);
if ( !trapid.valid() || trapid.len() < 2 )
{
snmp_free_pdu( raw_pdu);
return SNMP_CLASS_INVALID_NOTIFYID;
}
raw_pdu->specific_type=0;
if ( trapid == coldStart)
raw_pdu->trap_type = 0; // cold start
else if ( trapid == warmStart)
raw_pdu->trap_type = 1; // warm start
else if( trapid == linkDown)
raw_pdu->trap_type = 2; // link down
else if ( trapid == linkUp)
raw_pdu->trap_type = 3; // link up
else if ( trapid == authenticationFailure )
raw_pdu->trap_type = 4; // authentication failure
else if ( trapid == egpNeighborLoss)
raw_pdu->trap_type = 5; // egp neighbor loss
else {
raw_pdu->trap_type = 6; // enterprise specific
// last oid subid is the specific value
// if 2nd to last subid is "0", remove it
// enterprise is always the notify oid prefix
raw_pdu->specific_type = (int) trapid[(int) (trapid.len()-1)];
trapid.trim(1);
if ( trapid[(int)(trapid.len()-1)] == 0 )
trapid.trim(1);
enterprise = trapid;
}
if ( raw_pdu->trap_type !=6)
pdu->get_notify_enterprise( enterprise);
if ( enterprise.len() >0) {
// note!!
// these are hooks into an SNMP++ oid
// and therefor the raw_pdu enterprise
// should not free them. null them out!!
SmiLPOID rawOid;
rawOid = enterprise.oidval();
raw_pdu->enterprise = rawOid->ptr;
raw_pdu->enterprise_length = (int) rawOid->len;
}
// timestamp
TimeTicks timestamp;
pdu->get_notify_timestamp( timestamp);
raw_pdu->time = ( unsigned long) timestamp;
}
// if its a v2 trap then we need to make a few adjustments
// vb #1 is the timestamp
// vb #2 is the id, represented as an Oid
if (( raw_pdu->command == sNMP_PDU_TRAP) ||
( raw_pdu->command == sNMP_PDU_INFORM))
{
Vb tempvb;
temppdu = *pdu;
temppdu.trim(temppdu.get_vb_count());
// vb #1 is the timestamp
TimeTicks timestamp;
tempvb.set_oid(SNMP_MSG_OID_SYSUPTIME); // sysuptime
pdu->get_notify_timestamp( timestamp);
tempvb.set_value ( timestamp);
temppdu += tempvb;
// vb #2 is the id
Oid trapid;
tempvb.set_oid(SNMP_MSG_OID_TRAPID);
pdu->get_notify_id( trapid);
tempvb.set_value( trapid);
temppdu += tempvb;
// append the remaining vbs
for (int z=0; z<pdu->get_vb_count(); z++) {
pdu->get_vb( tempvb,z);
temppdu += tempvb;
}
pdu = &temppdu; // reassign the pdu to the temp one
}
// load up the payload
// for all Vbs in list, add them to the pdu
int vb_count;
Vb tempvb;
Oid tempoid;
SmiLPOID smioid;
SmiVALUE smival;
vb_count = pdu->get_vb_count();
for (int z=0;z<vb_count;z++) {
pdu->get_vb( tempvb,z);
tempvb.get_oid( tempoid);
smioid = tempoid.oidval();
// clear the value portion, in case its
// not already been done so by the app writer
// only do it in the case its a get,next or bulk
if ((raw_pdu->command == sNMP_PDU_GET) ||
(raw_pdu->command == sNMP_PDU_GETNEXT) ||
(raw_pdu->command == sNMP_PDU_GETBULK))
tempvb.set_null();
status = convertVbToSmival( tempvb, &smival );
if ( status != SNMP_CLASS_SUCCESS) {
snmp_free_pdu( raw_pdu);
return status;
}
// add the vb to the raw pdu
snmp_add_var( raw_pdu, smioid->ptr, (int) smioid->len, &smival);
freeSmivalDescriptor( &smival);
}
// ASN1 encode the pdu
#ifdef _SNMPv3
if (version == version3)
{
if ((!engine_id) || (!security_name))
{
LOG_BEGIN(ERROR_LOG | 4);
LOG("SNMPMessage: Need security name and engine id for v3 message");
LOG_END;
// prevention of SNMP++ Enterprise Oid death
if ( enterprise.len() >0) {
raw_pdu->enterprise = 0;
raw_pdu->enterprise_length=0;
}
snmp_free_pdu( raw_pdu);
return SNMP_CLASS_INVALID_TARGET;
}
status = v3MP::I->snmp_build(raw_pdu, databuff, (int *)&bufflen,
*engine_id, *security_name, security_model,
pdu->get_security_level(),
pdu->get_context_engine_id(),
pdu->get_context_name());
if (status == SNMPv3_MP_OK) {
if ((pdu->get_type() == sNMP_PDU_RESPONSE) &&
((int)pdu->get_maxsize_scopedpdu() < pdu->get_asn1_length())) {
LOG_BEGIN(ERROR_LOG | 1);
LOG("SNMPMessage: *BUG*: Serialized response pdu is too big (len) (max)");
LOG(pdu->get_asn1_length());
LOG(pdu->get_maxsize_scopedpdu());
LOG_END;
// prevention of SNMP++ Enterprise Oid death
if ( enterprise.len() >0) {
raw_pdu->enterprise = 0;
raw_pdu->enterprise_length=0;
}
snmp_free_pdu( raw_pdu);
return SNMP_ERROR_TOO_BIG;
}
}
}
else
#endif
status = snmp_build( raw_pdu, databuff, (int *) &bufflen, version,
community.data(), (int) community.len());
LOG_BEGIN(DEBUG_LOG | 4);
LOG("SNMPMessage: return value for build message");
LOG(status);
LOG_END;
if ((status != 0)
#ifdef _SNMPv3
&& ((version != version3) || (status != SNMPv3_MP_OK))
#endif
) {
valid_flag = false;
// prevention of SNMP++ Enterprise Oid death
if ( enterprise.len() >0) {
raw_pdu->enterprise = 0;
raw_pdu->enterprise_length=0;
}
snmp_free_pdu( raw_pdu);
#ifdef _SNMPv3
if (version == version3)
return status;
else
#endif
// NOTE: This is an assumption - in most cases during normal
// operation the reason is a tooBig - another could be a
// damaged variable binding.
return SNMP_ERROR_TOO_BIG;
}
valid_flag = true;
// prevention of SNMP++ Enterprise Oid death
if ( enterprise.len() >0) {
raw_pdu->enterprise = 0;
raw_pdu->enterprise_length=0;
}
snmp_free_pdu( raw_pdu);
return SNMP_CLASS_SUCCESS;
}
// Send a report message.
int v3MP::send_report(unsigned char* scopedPDU, int scopedPDULength,
struct snmp_pdu *pdu, int errorCode, int sLevel,
int sModel, OctetStr &sName,
UdpAddress &destination, Snmp *snmp_session)
{
debugprintf(2, "v3MP::send_report: Sending report message.");
unsigned char *data;
int dataLength;
int pdu_type = 0;
unsigned char cEngineID[MAXLENGTH_ENGINEID+1];
unsigned char cName[MAXLENGTH_CONTEXT_NAME+1];
int cEngineIDLength = MAXLENGTH_ENGINEID+1;
int cNameLength = MAXLENGTH_CONTEXT_NAME+1;
debugprintf(2, "v3MP::send_report: securityLevel %d",sLevel);
if (scopedPDULength != MAX_SNMP_PACKET)
{
// try to get scopedPDU and PDU
data = asn1_parse_scoped_pdu(scopedPDU, &scopedPDULength,
cEngineID, &cEngineIDLength,
cName, &cNameLength);
if (data == NULL) {
debugprintf(1, "mp: Error while trying to parse scopedPDU!");
cEngineID[0] = '\0';
cEngineIDLength = 0;
cName[0] = '\0';
cNameLength = 0;
// Dont send encrypted report if decryption failed:
//if (sLevel == SNMP_SECURITY_LEVEL_AUTH_PRIV)
// sLevel = SNMP_SECURITY_LEVEL_AUTH_NOPRIV;
}
else { // data != NULL
dataLength = scopedPDULength;
// parse data of scopedPDU
snmp_parse_data_pdu(pdu, data, dataLength);
pdu_type = pdu->command;
if (!data) {
debugprintf(0, "mp: Error while trying to parse PDU!");
}
} // end of: if (data == NULL)
} // end if (scopedPDULength != MAX_SNMP_PACKET)
else { // scopedPDULength == MAX_SNMP_PACKET
cEngineID[0] = '\0';
cEngineIDLength = 0;
cName[0] = '\0';
cNameLength = 0;
pdu->reqid = 0;
}
clear_pdu(pdu); // Clear pdu and free all content
debugprintf(4, "pdu->reqid = %ld",pdu->reqid);
pdu->errstat = 0;
pdu->errindex = 0;
pdu->command = REPORT_MSG;
Vb counterVb;
Oid counterOid;
SmiLPOID smioid;
SmiVALUE smival;
switch (errorCode) {
case SNMPv3_MP_INVALID_MESSAGE:
case SNMPv3_USM_PARSE_ERROR: {
counterVb.set_oid(oidSnmpInvalidMsgs);
counterVb.set_value(Counter32(get_stats_invalid_msgs()));
break;
}
case SNMPv3_USM_NOT_IN_TIME_WINDOW:
case SNMPv3_MP_NOT_IN_TIME_WINDOW: {
counterVb.set_oid(oidUsmStatsNotInTimeWindows);
counterVb.set_value(Counter32(usm->get_stats_not_in_time_windows()));
break;
}
case SNMPv3_USM_DECRYPTION_ERROR: {
counterVb.set_oid(oidUsmStatsDecryptionErrors);
counterVb.set_value(Counter32(usm->get_stats_decryption_errors()));
//sLevel = SNMP_SECURITY_LEVEL_NOAUTH_NOPRIV;
break;
}
case SNMPv3_USM_AUTHENTICATION_ERROR:
case SNMPv3_USM_AUTHENTICATION_FAILURE: {
counterVb.set_oid(oidUsmStatsWrongDigests);
counterVb.set_value(Counter32(usm->get_stats_wrong_digests()));
//sLevel = SNMP_SECURITY_LEVEL_NOAUTH_NOPRIV;
break;
}
case SNMPv3_USM_UNKNOWN_ENGINEID:
case SNMPv3_MP_INVALID_ENGINEID: {
//sLevel = SNMP_SECURITY_LEVEL_NOAUTH_NOPRIV;
counterVb.set_oid(oidUsmStatsUnknownEngineIDs);
counterVb.set_value(Counter32(usm->get_stats_unknown_engine_ids()));
break;
}
case SNMPv3_MP_UNSUPPORTED_SECURITY_MODEL: {
counterVb.set_oid(oidSnmpUnknownSecurityModels);
counterVb.set_value(Counter32(get_stats_unknown_security_models()));
sModel = SNMP_SECURITY_MODEL_USM;
sLevel = SNMP_SECURITY_LEVEL_NOAUTH_NOPRIV;
break;
}
case SNMPv3_USM_UNKNOWN_SECURITY_NAME: {
counterVb.set_oid(oidUsmStatsUnknownUserNames);
counterVb.set_value(Counter32(usm->get_stats_unknown_user_names()));
sLevel = SNMP_SECURITY_LEVEL_NOAUTH_NOPRIV;
debugprintf(2, "Report: SecurityName: %s",sName.get_printable());
break;
}
case SNMPv3_USM_UNSUPPORTED_SECURITY_LEVEL: {
counterVb.set_oid(oidUsmStatsUnsupportedSecLevels);
counterVb.set_value(Counter32(usm->get_stats_unsupported_sec_levels()));
sLevel = SNMP_SECURITY_LEVEL_NOAUTH_NOPRIV;
break;
}
default: {
counterVb.set_oid(oidSnmpInvalidMsgs);
counterVb.set_value(Counter32(get_stats_invalid_msgs()));
sModel = SNMP_SECURITY_MODEL_USM;
sLevel = SNMP_SECURITY_LEVEL_NOAUTH_NOPRIV;
sName.set_data(0, 0);
debugprintf(2, "ErrorCode was %i in snmp_parse", errorCode);
}
} // end switch
counterVb.get_oid(counterOid);
smioid = counterOid.oidval();
int status = convertVbToSmival(counterVb, &smival);
if (status != SNMP_CLASS_SUCCESS) {
return SNMPv3_MP_ERROR;
}
snmp_add_var(pdu, smioid->ptr,
(int) smioid->len, &smival);
freeSmivalDescriptor(&smival);
Buffer<unsigned char> sendbuffer(MAX_SNMP_PACKET);
int sendbufferlen= MAX_SNMP_PACKET;
status = snmp_build( pdu, sendbuffer.get_ptr(), &sendbufferlen,
own_engine_id_oct, sName, sModel, sLevel,
OctetStr(cEngineID, cEngineIDLength),
OctetStr(cName, cNameLength));
if (status != SNMPv3_MP_OK) {
debugprintf(2, "v3MP::send_report: error serializing message (mpSnmpBuild returns: %i).", status);
return SNMPv3_MP_ERROR;
}
SnmpSocket send_fd = INVALID_SOCKET;
if (pdu_type == sNMP_PDU_INFORM)
{
debugprintf(4, "Received a snmpInform pdu.");
if (snmp_session->get_eventListHolder()->notifyEventList())
send_fd = snmp_session->get_eventListHolder()->notifyEventList()->get_notify_fd();
}
status = snmp_session->send_raw_data(sendbuffer.get_ptr(),
(size_t)sendbufferlen,// pdu to send
destination, // target address
send_fd); // the fd to use
if ( status != 0)
{
debugprintf(1, "v3MP::send_report: error sending message (%i)", status);
return SNMPv3_MP_ERROR;
}
debugprintf(3, "v3MP::send_report: Report sent.");
return SNMPv3_MP_OK;
}
int main(void)
{
netsnmp_session session;
netsnmp_pdu *pdu;
netsnmp_variable_list *vars;
int status=45,ctr,i;
pdu = (netsnmp_pdu *) calloc(1, sizeof(netsnmp_pdu));
if (pdu)
{
//pdu->version = SNMP_VERSION_1;
//pdu->command = SNMP_MSG_RESPONSE;
//pdu->errstat = SNMP_DEFAULT_ERRSTAT;
//pdu->errindex = SNMP_DEFAULT_ERRINDEX;
pdu->securityModel = SNMP_DEFAULT_SECMODEL;
pdu->transport_data = NULL;
pdu->transport_data_length = 0;
pdu->securityNameLen = 0;
pdu->contextNameLen = 0;
pdu->time = 0;
pdu->reqid = snmp_get_next_reqid();
pdu->msgid = snmp_get_next_msgid();
}
printf("Message before parsing\n");
for(ctr=0;ctr<pktlen;ctr++)
printf("%x",pkt[ctr]);
printf("\n\n");
status=snmp_parse(&session,pdu,pkt,pktlen);
printf("Status %d",status);
for(vars = pdu->variables; vars; vars = vars->next_variable)
{
print_variable(vars->name, vars->name_length, vars);
}
printf("pdu:\nversion:%ld\ncommand:%d\n",pdu->version,pdu->command);
printf("Decoding done. \n Now encoding...");
status=snmp_build(&newpkt,&newpktlen,&offset,&session,pdu);
printf("\nstatus = %d\n",status);
printf("\nnewpktlen = %d\n",newpktlen);
printf("\noffset = %d\n",offset);
if(status==0 || status==-20)
{
//newpktlen=sizeof(newpkt);
//printf("seems successful\n Here's the new packet:\npktlen :%d\n",newpktlen);
printf("Packet dump : \n");
for(ctr=newpktlen-offset;ctr<newpktlen;ctr++)
{
printf("%X",newpkt[ctr]);
}
printf("\nPacket dump - END \n");
for(ctr=newpktlen-offset,i=0;i<pktlen && ctr<newpktlen;i++,ctr++)
{
if(newpkt[ctr]!=pkt[i])
{
printf("\nMISMATCH");
exit(1);
}
}
printf("\nMATCH!!!!\n Parse successful\n");
}
return (0);
}