1/**************************************************************************** 2 * ip_conntrack_h323_asn1.h - BER and PER decoding library for H.323 3 * conntrack/NAT module. 4 * 5 * Copyright (c) 2006 by Jing Min Zhao <zhaojingmin@users.sourceforge.net> 6 * 7 * This source code is licensed under General Public License version 2. 8 * 9 * 10 * This library is based on H.225 version 4, H.235 version 2 and H.245 11 * version 7. It is extremely optimized to decode only the absolutely 12 * necessary objects in a signal for Linux kernel NAT module use, so don't 13 * expect it to be a full ASN.1 library. 14 * 15 * Features: 16 * 17 * 1. Small. The total size of code plus data is less than 20 KB (IA32). 18 * 2. Fast. Decoding Netmeeting's Setup signal 1 million times on a PIII 866 19 * takes only 3.9 seconds. 20 * 3. No memory allocation. It uses a static object. No need to initialize or 21 * cleanup. 22 * 4. Thread safe. 23 * 5. Support embedded architectures that has no misaligned memory access 24 * support. 25 * 26 * Limitations: 27 * 28 * 1. At most 30 faststart entries. Actually this is limited by ethernet's MTU. 29 * If a Setup signal contains more than 30 faststart, the packet size will 30 * very likely exceed the MTU size, then the TPKT will be fragmented. I 31 * don't know how to handle this in a Netfilter module. Anybody can help? 32 * Although I think 30 is enough for most of the cases. 33 * 2. IPv4 addresses only. 34 * 35 ****************************************************************************/ 36 37#ifndef _NF_CONNTRACK_HELPER_H323_ASN1_H_ 38#define _NF_CONNTRACK_HELPER_H323_ASN1_H_ 39 40/***************************************************************************** 41 * H.323 Types 42 ****************************************************************************/ 43#include "nf_conntrack_h323_types.h" 44 45typedef struct { 46 enum { 47 Q931_NationalEscape = 0x00, 48 Q931_Alerting = 0x01, 49 Q931_CallProceeding = 0x02, 50 Q931_Connect = 0x07, 51 Q931_ConnectAck = 0x0F, 52 Q931_Progress = 0x03, 53 Q931_Setup = 0x05, 54 Q931_SetupAck = 0x0D, 55 Q931_Resume = 0x26, 56 Q931_ResumeAck = 0x2E, 57 Q931_ResumeReject = 0x22, 58 Q931_Suspend = 0x25, 59 Q931_SuspendAck = 0x2D, 60 Q931_SuspendReject = 0x21, 61 Q931_UserInformation = 0x20, 62 Q931_Disconnect = 0x45, 63 Q931_Release = 0x4D, 64 Q931_ReleaseComplete = 0x5A, 65 Q931_Restart = 0x46, 66 Q931_RestartAck = 0x4E, 67 Q931_Segment = 0x60, 68 Q931_CongestionCtrl = 0x79, 69 Q931_Information = 0x7B, 70 Q931_Notify = 0x6E, 71 Q931_Status = 0x7D, 72 Q931_StatusEnquiry = 0x75, 73 Q931_Facility = 0x62 74 } MessageType; 75 H323_UserInformation UUIE; 76} Q931; 77 78/***************************************************************************** 79 * Decode Functions Return Codes 80 ****************************************************************************/ 81 82#define H323_ERROR_NONE 0 /* Decoded successfully */ 83#define H323_ERROR_STOP 1 /* Decoding stopped, not really an error */ 84#define H323_ERROR_BOUND -1 85#define H323_ERROR_RANGE -2 86 87 88/***************************************************************************** 89 * Decode Functions 90 ****************************************************************************/ 91 92int DecodeRasMessage(unsigned char *buf, size_t sz, RasMessage * ras); 93int DecodeQ931(unsigned char *buf, size_t sz, Q931 * q931); 94int DecodeMultimediaSystemControlMessage(unsigned char *buf, size_t sz, 95 MultimediaSystemControlMessage * 96 mscm); 97 98#endif 99