/* SPDX-License-Identifier: GPL-2.0-only */
|
/****************************************************************************
|
* BER and PER decoding library for H.323 conntrack/NAT module.
|
*
|
* Copyright (c) 2006 by Jing Min Zhao <zhaojingmin@users.sourceforge.net>
|
*
|
* This library is based on H.225 version 4, H.235 version 2 and H.245
|
* version 7. It is extremely optimized to decode only the absolutely
|
* necessary objects in a signal for Linux kernel NAT module use, so don't
|
* expect it to be a full ASN.1 library.
|
*
|
* Features:
|
*
|
* 1. Small. The total size of code plus data is less than 20 KB (IA32).
|
* 2. Fast. Decoding Netmeeting's Setup signal 1 million times on a PIII 866
|
* takes only 3.9 seconds.
|
* 3. No memory allocation. It uses a static object. No need to initialize or
|
* cleanup.
|
* 4. Thread safe.
|
* 5. Support embedded architectures that has no misaligned memory access
|
* support.
|
*
|
* Limitations:
|
*
|
* 1. At most 30 faststart entries. Actually this is limited by ethernet's MTU.
|
* If a Setup signal contains more than 30 faststart, the packet size will
|
* very likely exceed the MTU size, then the TPKT will be fragmented. I
|
* don't know how to handle this in a Netfilter module. Anybody can help?
|
* Although I think 30 is enough for most of the cases.
|
* 2. IPv4 addresses only.
|
*
|
****************************************************************************/
|
|
#ifndef _NF_CONNTRACK_HELPER_H323_ASN1_H_
|
#define _NF_CONNTRACK_HELPER_H323_ASN1_H_
|
|
/*****************************************************************************
|
* H.323 Types
|
****************************************************************************/
|
|
#include <linux/types.h>
|
#include <linux/netfilter/nf_conntrack_h323_types.h>
|
|
typedef struct {
|
enum {
|
Q931_NationalEscape = 0x00,
|
Q931_Alerting = 0x01,
|
Q931_CallProceeding = 0x02,
|
Q931_Connect = 0x07,
|
Q931_ConnectAck = 0x0F,
|
Q931_Progress = 0x03,
|
Q931_Setup = 0x05,
|
Q931_SetupAck = 0x0D,
|
Q931_Resume = 0x26,
|
Q931_ResumeAck = 0x2E,
|
Q931_ResumeReject = 0x22,
|
Q931_Suspend = 0x25,
|
Q931_SuspendAck = 0x2D,
|
Q931_SuspendReject = 0x21,
|
Q931_UserInformation = 0x20,
|
Q931_Disconnect = 0x45,
|
Q931_Release = 0x4D,
|
Q931_ReleaseComplete = 0x5A,
|
Q931_Restart = 0x46,
|
Q931_RestartAck = 0x4E,
|
Q931_Segment = 0x60,
|
Q931_CongestionCtrl = 0x79,
|
Q931_Information = 0x7B,
|
Q931_Notify = 0x6E,
|
Q931_Status = 0x7D,
|
Q931_StatusEnquiry = 0x75,
|
Q931_Facility = 0x62
|
} MessageType;
|
H323_UserInformation UUIE;
|
} Q931;
|
|
/*****************************************************************************
|
* Decode Functions Return Codes
|
****************************************************************************/
|
|
#define H323_ERROR_NONE 0 /* Decoded successfully */
|
#define H323_ERROR_STOP 1 /* Decoding stopped, not really an error */
|
#define H323_ERROR_BOUND -1
|
#define H323_ERROR_RANGE -2
|
|
|
/*****************************************************************************
|
* Decode Functions
|
****************************************************************************/
|
|
int DecodeRasMessage(unsigned char *buf, size_t sz, RasMessage * ras);
|
int DecodeQ931(unsigned char *buf, size_t sz, Q931 * q931);
|
int DecodeMultimediaSystemControlMessage(unsigned char *buf, size_t sz,
|
MultimediaSystemControlMessage *
|
mscm);
|
|
#endif
|
