/********************************************************************
* Function: DCE2_ClHdrChecks()
*
* Checks to make sure header fields are sane. If they aren't,
* alert on the header anomaly. If we've autodetected the session,
* however, don't alert, but set a header anomaly flag, so we can
* re-autodetect on the next go around.
*
* Arguments:
* DCE2_SsnData *
* Pointer to the session data structure.
* DceRpcClHdr *
* Pointer to the connectionless header in the packet.
*
* Returns:
* DCE2_Ret
* DCE2_RET__ERROR
* We should not continue to inspect.
* DCE2_RET__SUCCESS
* Continue inspection.
*
********************************************************************/
static DCE2_Ret DCE2_ClHdrChecks(DCE2_SsnData *sd, const DceRpcClHdr *cl_hdr)
{
if (DceRpcClRpcVers(cl_hdr) != DCERPC_PROTO_MAJOR_VERS__4)
{
/* If we autodetected the session, we probably guessed wrong */
if (!DCE2_SsnAutodetected(sd))
DCE2_Alert(sd, DCE2_EVENT__CL_BAD_MAJ_VERSION, DceRpcClRpcVers(cl_hdr));
return DCE2_RET__ERROR;
}
if (DceRpcClPduType(cl_hdr) >= DCERPC_PDU_TYPE__MAX)
{
if (!DCE2_SsnAutodetected(sd))
DCE2_Alert(sd, DCE2_EVENT__CL_BAD_PDU_TYPE, DceRpcClPduType(cl_hdr));
return DCE2_RET__ERROR;
}
return DCE2_RET__SUCCESS;
}
/********************************************************************
* Function: DCE2_ClProcess()
*
* Main entry point for connectionless DCE/RPC processing. Gets
* the activity tracker associated with this session and passes
* along to client or server handling.
*
* Arguments:
* DCE2_SsnData *
* Pointer to the session data structure.
* DCE2_ClTracker *
* Pointer to the connectionless tracker structure.
*
* Returns: None
*
********************************************************************/
void DCE2_ClProcess(DCE2_SsnData *sd, DCE2_ClTracker *clt)
{
DceRpcClHdr *cl_hdr;
DCE2_ClActTracker *at;
const uint8_t *data_ptr = sd->wire_pkt->payload;
uint16_t data_len = sd->wire_pkt->payload_size;
PROFILE_VARS;
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__CL, "Cl processing ...\n"));
dce2_stats.cl_pkts++;
if (data_len < sizeof(DceRpcClHdr))
{
if (!DCE2_SsnAutodetected(sd))
DCE2_Alert(sd, DCE2_EVENT__CL_DATA_LT_HDR, data_len, sizeof(DceRpcClHdr));
return;
}
cl_hdr = (DceRpcClHdr *)data_ptr;
DCE2_MOVE(data_ptr, data_len, sizeof(DceRpcClHdr));
if (DCE2_ClHdrChecks(sd, cl_hdr) != DCE2_RET__SUCCESS)
return;
PREPROC_PROFILE_START(dce2_pstat_cl_acts);
at = DCE2_ClGetActTracker(clt, cl_hdr);
PREPROC_PROFILE_END(dce2_pstat_cl_acts);
if (at == NULL)
return;
if (DCE2_SsnFromClient(sd->wire_pkt))
{
switch (DceRpcClPduType(cl_hdr))
{
case DCERPC_PDU_TYPE__REQUEST:
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__CL, "Request\n"));
dce2_stats.cl_request++;
DCE2_ClRequest(sd, at, cl_hdr, data_ptr, data_len);
break;
case DCERPC_PDU_TYPE__ACK:
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__CL, "Ack\n"));
dce2_stats.cl_ack++;
break;
case DCERPC_PDU_TYPE__CL_CANCEL:
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__CL, "Cancel\n"));
dce2_stats.cl_cancel++;
break;
case DCERPC_PDU_TYPE__FACK:
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__CL, "Fack\n"));
dce2_stats.cl_cli_fack++;
break;
case DCERPC_PDU_TYPE__PING:
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__CL, "Ping\n"));
dce2_stats.cl_ping++;
break;
case DCERPC_PDU_TYPE__RESPONSE:
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__CL, "Response from client. Changing stream direction."));
_dpd.streamAPI->update_direction(sd->wire_pkt->stream_session, SSN_DIR_FROM_RESPONDER,
GET_SRC_IP(((SFSnortPacket *)sd->wire_pkt)),
sd->wire_pkt->src_port);
break;
default:
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__CL, "Other pdu type\n"));
dce2_stats.cl_other_req++;
break;
}
}
else
{
switch (DceRpcClPduType(cl_hdr))
{
case DCERPC_PDU_TYPE__RESPONSE:
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__CL, "Response\n"));
dce2_stats.cl_response++;
break;
case DCERPC_PDU_TYPE__REJECT:
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__CL, "Reject\n"));
dce2_stats.cl_reject++;
if (DceRpcClSeqNum(cl_hdr) == at->seq_num)
{
DCE2_ClResetFragTracker(&at->frag_tracker);
at->seq_num_invalid = 1;
}
break;
case DCERPC_PDU_TYPE__CANCEL_ACK:
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__CL, "Cancel Ack\n"));
dce2_stats.cl_cancel_ack++;
break;
case DCERPC_PDU_TYPE__FACK:
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__CL, "Fack\n"));
dce2_stats.cl_srv_fack++;
break;
case DCERPC_PDU_TYPE__FAULT:
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__CL, "Fault\n"));
dce2_stats.cl_fault++;
break;
case DCERPC_PDU_TYPE__NOCALL:
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__CL, "No call\n"));
dce2_stats.cl_nocall++;
break;
case DCERPC_PDU_TYPE__WORKING:
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__CL, "Working\n"));
dce2_stats.cl_working++;
break;
default:
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__CL, "Other pdu type\n"));
dce2_stats.cl_other_resp++;
break;
}
}
}
/*********************************************************************
* Function: DCE2_Process()
*
* Purpose: Main entry point for DCE/RPC processing.
*
* Arguments:
* SFSnortPacket * - pointer to packet structure
*
* Returns:
* DCE2_Ret - status
*
*********************************************************************/
DCE2_Ret DCE2_Process(SFSnortPacket *p)
{
tSfPolicyId policy_id = _dpd.getNapRuntimePolicy();
DCE2_SsnData *sd = (DCE2_SsnData *)DCE2_SsnGetAppData(p);
PROFILE_VARS;
PREPROC_PROFILE_START(dce2_pstat_session);
if ((sd != NULL) && DCE2_SsnNoInspect(sd))
{
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__MAIN, "Session set to "
"not inspect. Returning\n"));
PREPROC_PROFILE_END(dce2_pstat_session);
return DCE2_RET__NOT_INSPECTED;
}
dce2_eval_config = (DCE2_Config *)sfPolicyUserDataGet(dce2_config, policy_id);
if (sd != NULL)
dce2_eval_config = (DCE2_Config *)sfPolicyUserDataGet(sd->config, sd->policy_id);
if (dce2_eval_config == NULL)
{
PREPROC_PROFILE_END(dce2_pstat_session);
return DCE2_RET__NOT_INSPECTED;
}
if (sd == NULL)
{
sd = DCE2_NewSession(p, policy_id);
if (sd == NULL)
{
PREPROC_PROFILE_END(dce2_pstat_session);
return DCE2_RET__NOT_INSPECTED;
}
}
else
{
sd->wire_pkt = p;
if (_dpd.isPafEnabled() && !DCE2_SsnIsPafActive(p))
{
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__MAIN, "PAF was aborted on "
"one or both sides - aborting session inspection\n"));
DCE2_SetNoInspect(sd);
PREPROC_PROFILE_END(dce2_pstat_session);
return DCE2_RET__NOT_INSPECTED;
}
if (IsTCP(p) && !DCE2_SsnIsRebuilt(p))
{
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__MAIN, "Got non-rebuilt packet "
"on session (%p)\n", (void *)sd));
if (DCE2_SsnIsStreamInsert(p))
{
if (!_dpd.isPafEnabled())
{
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__MAIN, "Flushing opposite direction.\n"));
DCE2_SsnFlush(p);
}
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__MAIN, "Stream inserted - not inspecting.\n"));
}
else
{
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__MAIN, "Got non-stream inserted packet "
"- not inspecting\n"));
}
PREPROC_PROFILE_END(dce2_pstat_session);
return DCE2_RET__NOT_INSPECTED;
}
else if (DCE2_SsnAutodetected(sd) && !(p->flags & sd->autodetect_dir))
{
/* Try to autodetect in opposite direction */
if ((sd->trans != DCE2_TRANS_TYPE__HTTP_PROXY) &&
(sd->trans != DCE2_TRANS_TYPE__HTTP_SERVER) &&
(DCE2_GetAutodetectTransport(p, sd->sconfig) != sd->trans))
{
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__MAIN, "Bad autodetect.\n"));
DCE2_SetNoInspect(sd);
dce2_stats.bad_autodetects++;
PREPROC_PROFILE_END(dce2_pstat_session);
return DCE2_RET__NOT_INSPECTED;
}
DCE2_SsnClearAutodetected(sd);
}
}
DEBUG_WRAP(DCE2_DebugMsg(DCE2_DEBUG__MAIN, "Session pointer: %p\n", (void *)sd));
if (IsTCP(p) && (DCE2_SetSsnState(sd, p) != DCE2_RET__SUCCESS))
{
PREPROC_PROFILE_END(dce2_pstat_session);
return DCE2_RET__NOT_INSPECTED;
}
if (DCE2_PushPkt((void *)p) != DCE2_RET__SUCCESS)
{
DCE2_Log(DCE2_LOG_TYPE__ERROR,
"%s(%d) Failed to push packet onto packet stack.",
__FILE__, __LINE__);
PREPROC_PROFILE_END(dce2_pstat_session);
return DCE2_RET__NOT_INSPECTED;
}
p->flags |= FLAG_ALLOW_MULTIPLE_DETECT;
dce2_detected = 0;
PREPROC_PROFILE_END(dce2_pstat_session);
switch (sd->trans)
{
case DCE2_TRANS_TYPE__SMB:
DCE2_SmbProcess((DCE2_SmbSsnData *)sd);
break;
case DCE2_TRANS_TYPE__TCP:
DCE2_TcpProcess((DCE2_TcpSsnData *)sd);
break;
case DCE2_TRANS_TYPE__UDP:
DCE2_UdpProcess((DCE2_UdpSsnData *)sd);
break;
case DCE2_TRANS_TYPE__HTTP_PROXY:
DCE2_HttpProcessProxy((DCE2_HttpSsnData *)sd);
break;
case DCE2_TRANS_TYPE__HTTP_SERVER:
DCE2_HttpProcessServer((DCE2_HttpSsnData *)sd);
break;
default:
DCE2_Log(DCE2_LOG_TYPE__ERROR,
"%s(%d) Invalid transport type: %d",
__FILE__, __LINE__, sd->trans);
return DCE2_RET__NOT_INSPECTED;
}
if (sd->flags & DCE2_SSN_FLAG__NO_INSPECT)
{
DCE2_SetNoInspect(sd);
DCE2_PopPkt();
PREPROC_PROFILE_END(dce2_pstat_session);
return DCE2_RET__NOT_INSPECTED;
}
if (!dce2_detected)
DCE2_Detect(sd);
DCE2_ResetRopts(&sd->ropts);
DCE2_PopPkt();
if (dce2_mem_state == DCE2_MEM_STATE__MEMCAP)
{
DCE2_SetNoInspect(sd);
dce2_mem_state = DCE2_MEM_STATE__OKAY;
return DCE2_RET__NOT_INSPECTED;
}
if (DCE2_SsnAutodetected(sd))
return DCE2_RET__NOT_INSPECTED;
return DCE2_RET__INSPECTED;
}
