LXR linux/include/linux/netfilter/nf_conntrack_h323

   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 <linux/netfilter/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