/******************************************************************** * Function: DCE2_ClFragReassemble() * * Reassembles fragments into reassembly buffer and copies to * reassembly packet. * * Arguments: * DCE2_SsnData * * Pointer to the session data structure. * DCE2_ClActTracker * * Pointer to the connectionless activity tracker. * DceRpcClHdr * * Pointer to the connectionless header in the packet. * * Returns: None * ********************************************************************/ static void DCE2_ClFragReassemble(DCE2_SsnData *sd, DCE2_ClActTracker *at, const DceRpcClHdr *cl_hdr) { DCE2_ClFragTracker *ft = &at->frag_tracker; DCE2_ClFragNode *fnode; uint8_t *rdata = dce2_cl_rbuf; uint16_t rlen = sizeof(dce2_cl_rbuf); uint32_t stub_len = 0; const uint8_t *stub_data = NULL; SFSnortPacket *rpkt = NULL; PROFILE_VARS; PREPROC_PROFILE_START(dce2_pstat_cl_reass); for (fnode = (DCE2_ClFragNode *)DCE2_ListFirst(ft->frags); fnode != NULL; fnode = (DCE2_ClFragNode *)DCE2_ListNext(ft->frags)) { if (fnode->frag_len > rlen) { DCE2_Log(DCE2_LOG_TYPE__WARN, "%s(%d) Size of fragments exceeds reassembly buffer size. " "Using as many fragments as will fit.", __FILE__, __LINE__); break; } if (DCE2_Memcpy(rdata, fnode->frag_data, fnode->frag_len, rdata, rdata + rlen) != DCE2_RET__SUCCESS) { DCE2_Log(DCE2_LOG_TYPE__ERROR, "%s(%d) Failed to copy data into fragment " "reassembly buffer.", __FILE__, __LINE__); break; } DCE2_MOVE(rdata, rlen, fnode->frag_len); stub_len += fnode->frag_len; } switch (sd->trans) { case DCE2_TRANS_TYPE__UDP: rpkt = DCE2_GetRpkt(sd->wire_pkt, DCE2_RPKT_TYPE__UDP_CL_FRAG, dce2_cl_rbuf, stub_len); if (rpkt == NULL) { DCE2_Log(DCE2_LOG_TYPE__ERROR, "%s(%d) Failed to create reassembly packet.", __FILE__, __LINE__); PREPROC_PROFILE_END(dce2_pstat_cl_reass); return; } DCE2_ClSetRdata(at, cl_hdr, (uint8_t *)rpkt->payload, (uint16_t)(rpkt->payload_size - DCE2_MOCK_HDR_LEN__CL)); stub_data = rpkt->payload + DCE2_MOCK_HDR_LEN__CL; break; default: DCE2_Log(DCE2_LOG_TYPE__ERROR, "%s(%d) Invalid transport type: %d", __FILE__, __LINE__, sd->trans); return; } PREPROC_PROFILE_END(dce2_pstat_cl_reass); if (DCE2_PushPkt(rpkt) != DCE2_RET__SUCCESS) { DCE2_Log(DCE2_LOG_TYPE__ERROR, "%s(%d) Failed to push packet onto packet stack.", __FILE__, __LINE__); return; } /* Cache relevant values for rule option processing */ sd->ropts.first_frag = 1; DCE2_CopyUuid(&sd->ropts.iface, &ft->iface, DCERPC_BO_FLAG__NONE); sd->ropts.iface_vers = ft->iface_vers; sd->ropts.hdr_byte_order = DceRpcClByteOrder(cl_hdr); if (ft->data_byte_order != DCE2_SENTINEL) sd->ropts.data_byte_order = ft->data_byte_order; else sd->ropts.data_byte_order = DceRpcClByteOrder(cl_hdr); if (ft->opnum != DCE2_SENTINEL) sd->ropts.opnum = ft->opnum; else sd->ropts.opnum = DceRpcClOpnum(cl_hdr); sd->ropts.stub_data = stub_data; DCE2_Detect(sd); DCE2_PopPkt(); dce2_stats.cl_frag_reassembled++; }
/********************************************************************* * 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; }