Leaked source code of windows server 2003
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/* (C) 1997-2000 Microsoft Corp.
*
* file : ConPDU.c
* author : Erik Mavrinac
*
* description: Handles decoding of MCS connect PDUs. Connect PDUs are always
* encoded with ASN.1 basic encoding rules (BER). Included in this file are
* local functions to BER-decode and -encode various types used in MCS PDUs.
*
* History:
* 11-Aug-1997 jparsons Fixed BER decode routines.
*/
#include "precomp.h"
#pragma hdrstop
#include <MCSImpl.h>
/*
* Defines
*/
// Return codes for encode/decode functions.
#define H_OK 0
#define H_TooShort 1
#define H_BadContents 2
#define H_Error 3
/*
* Prototypes for handler functions.
*/
BOOLEAN __fastcall HandleConnectInitial(PDomain, BYTE *, unsigned, unsigned *);
BOOLEAN __fastcall HandleConnectResponse(PDomain, BYTE *, unsigned, unsigned *);
BOOLEAN __fastcall HandleConnectAdditional(PDomain, BYTE *, unsigned, unsigned *);
BOOLEAN __fastcall HandleConnectResult(PDomain, BYTE *, unsigned, unsigned *);
/*
* These are listed in the 101-based enumeration order specified in the T.125
* spec. Decode the initial BER connect PDU 0x7F, then subtract 101 decimal
* from the next byte value to get an index into this table. E.g. the bytes
* 0x7F65 at the beginning refer to a connect-initial PDU.
*/
const MCSPDUInfo ConnectPDUTable[] = {
StrOnDbg("Connect Initial", HandleConnectInitial),
StrOnDbg("Connect Response", NULL /* HandleConnectResponse */),
StrOnDbg("Connect Additional", NULL /* HandleConnectAdditional */),
StrOnDbg("Connect Result", NULL /* HandleConnectResult */),
};
/*
* Decodes BER strings used by MCS. A BER stream is a set of tags
* containing ID-length-contents triplets, using byte values as type and
* length indicators unless length escapes are used. For example, a
* typical tag:
*
* 0x02 0x02 0x04 0x00
*
* Decomposition:
* 0x02: Id = INTEGER_TAG
* 0x02: Length = 2 octets
* 0x04 0x00: Contents = 1024 (0x0400)
*
* Escaped tag:
*
* 0x04 0x82 0x04 0x00 0x8a 0x96...
*
* Decomposition:
* 0x04: Id = OCTET_STRING_TAG
* 0x82: Length stored in TWO bytes
* 0x04 0x00: Length = 1024 octets
* 0x8a 0x96...: Contents = 0x8 0x96... (1022 more octets)
*
* Returns FALSE if the frame is too small.
*
* History:
* 11-Aug-97 jparsons Fixed pointer dereferencing error in calculating length
*
*/
#define LengthModifier_Indefinite 0x80
#define LengthModifier_1 0x81
#define LengthModifier_2 0x82
#define LengthModifier_3 0x83
#define LengthModifier_4 0x84
#define TagType_Boolean 0x01
#define TagType_Integer 0x02
#define TagType_BitString 0x03
#define TagType_OctetString 0x04
#define TagType_Enumeration 0x0A
#define TagType_Sequence 0x30
#define TagType_SetOf 0x31
#define TagType_ConnectInitial 0x65
#define TagType_ConnectResponse 0x66
#define TagType_ConnectAdditional 0x67
#define TagType_ConnectResult 0x68
int DecodeTagBER(
PSDCONTEXT pContext, // For tracing.
BYTE *Frame,
unsigned *OutBytesLeft,
int TagTypeExpected,
unsigned *OutDataLength,
UINT_PTR *Data,
BYTE **newFrame)
{
int rc = H_OK;
int TagType;
unsigned i, BytesLeft, DataLength;
BytesLeft = *OutBytesLeft;
DataLength = *OutDataLength;
if (BytesLeft >= 2) {
// Get tag type, check it.
TagType = *Frame;
Frame++;
BytesLeft--;
if (TagType != TagTypeExpected) {
ErrOut2(pContext, "Unexpected tag type found decoding BER tag, "
"recv %d != expect %d", TagType, TagTypeExpected);
rc = H_BadContents;
goto ExitFunc;
}
}
else {
ErrOut(pContext, "BER PDU too short");
rc = H_TooShort;
goto ExitFunc;
}
// Find tag length indicator, including escapes.
if (*Frame >= LengthModifier_Indefinite && *Frame <= LengthModifier_4) {
unsigned NLengthBytes;
// Check zero size for LengthModifier_Indefinite.
NLengthBytes = 4 + *Frame - LengthModifier_4;
if (NLengthBytes == 0)
NLengthBytes = 1;
if (BytesLeft >= NLengthBytes) {
Frame++; // Now at beginning of length bytes
BytesLeft--;
DataLength = 0;
for (i = 0; i < NLengthBytes; i++) {
DataLength = (DataLength << 8) + (unsigned)(*Frame);
Frame++;
}
BytesLeft -= NLengthBytes;
}
else {
ErrOut(pContext, "BER PDU too short");
rc = H_TooShort;
goto ExitFunc;
}
}
else {
DataLength = *Frame;
Frame++;
BytesLeft--;
}
if (BytesLeft >= DataLength) {
// Frame now points to beginning of contents. Fill out *Data with info
// based on the tag type.
switch (TagType) {
case TagType_Boolean:
case TagType_Integer:
case TagType_Enumeration:
// Fill in *Data with the actual data. Fill out *BytesLeft
// so that we consume the contents. Discard if requested.
if (Data != NULL) {
unsigned Sum;
Sum = 0;
for (i = 0; i < DataLength; i++) {
Sum = (Sum << 8) + *Frame;
Frame++;
}
*Data = Sum;
}
else
Frame += DataLength;
BytesLeft -= DataLength;
break;
case TagType_OctetString:
// Fill in *Data with a pointer into the frame of the
// beginning of the data.
if (Data != NULL)
*Data = (UINT_PTR)Frame;
Frame += DataLength;
BytesLeft -= DataLength;
break;
// For these, we really just want to consume the tag and length
case TagType_ConnectInitial:
case TagType_Sequence:
break;
// MCS FUTURE: Add TagType_BitString
default:
ErrOut1(pContext, "Unknown TagType in DecodeTagBER (%u)",
TagType);
rc = H_BadContents;
goto ExitFunc;
}
}
else {
ErrOut(pContext, "BER PDU too short");
rc = H_TooShort;
goto ExitFunc;
}
ExitFunc:
*newFrame = Frame;
*OutBytesLeft = BytesLeft;
*OutDataLength = DataLength;
return rc;
}
/*
* BER-encodes by parameter type. Advances pointer at *Frame past the encoded
* bytes to allow for a current-pointer mechanism to be used. Parameter
* usage as follows:
*
* Tag type Params
* ---------------------------------------------------------------
* bool, int, enum Data: The value to encode, maximum 0x7FFFFFFF.
* DataLength: Unused.
*
* octet str, seq DataLength: Length of the sequence/string.
* Data: Pointer to beginning of data to copy.
* (Data can be NULL to prevent copying user data.)
*
* bitstring Not yet supported
*/
void EncodeTagBER (
PSDCONTEXT pContext, // For tracing.
BYTE *Frame,
int TagType,
unsigned DataLength,
UINT_PTR Data,
unsigned *pNBytesConsumed,
BYTE **newFrame)
{
int i, Length, NBytesConsumed;
// Encode tag type.
*Frame = (BYTE)TagType;
Frame++;
NBytesConsumed = 1;
// Encode tag length indicator, including escapes, then encode the actual
// tag data, if applicable.
switch (TagType) {
case TagType_Boolean:
case TagType_Integer:
case TagType_Enumeration:
// Encode the bool or int size in bytes.
if (Data < 0x80) Length = 1;
else if (Data < 0x8000) Length = 2;
else if (Data < 0x800000) Length = 3;
else if (Data < 0x80000000) Length = 4;
else {
ErrOut(pContext,
"Cannot BER-encode the size for an int/bool tag");
ASSERT(FALSE);
break;
}
*Frame = (BYTE)Length;
Frame++;
NBytesConsumed++;
// Encode the bool/int/enum data.
for (i = 0; i < Length; i++) {
*Frame = (BYTE)(Data >> (8 * (Length - 1 - i)));
Frame++;
}
NBytesConsumed += Length;
break;
case TagType_OctetString:
case TagType_Sequence:
// Determine the length of DataLength. Escape if greater than 1.
if (DataLength < 0x80)
Length = 1;
else if (DataLength < 0x8000) {
Length = 2;
*Frame = LengthModifier_2;
Frame++;
NBytesConsumed++;
}
else if (DataLength < 0x800000) {
Length = 3;
*Frame = LengthModifier_3;
Frame++;
NBytesConsumed++;
}
else if (DataLength < 0x80000000) {
Length = 4;
*Frame = LengthModifier_4;
Frame++;
NBytesConsumed++;
}
else {
ErrOut(pContext,
"Cannot BER-encode the length for an octet string tag");
ASSERT(FALSE);
break;
}
for (i = 0; i < Length; i++) {
*Frame = (BYTE)(DataLength >> (8 * (Length - 1 - i)));
Frame++;
}
NBytesConsumed += Length;
// Encode the string data.
if (((BYTE *)Data) != NULL) {
// This case is never used since we create headers only.
// If this were to be used we would need to copy memory.
memcpy(Frame, (BYTE *)Data, DataLength);
Frame += DataLength;
NBytesConsumed += DataLength;
}
break;
// MCS FUTURE: Add TagType_BitString.
}
*newFrame = Frame;
*pNBytesConsumed = NBytesConsumed;
}
/*
* BER-encodes the given domain parameters.
*/
void EncodeDomainParameters(
PSDCONTEXT pContext, // For tracing.
BYTE *Frame,
int *pNBytesConsumed,
const DomainParameters *pDomParams,
BYTE **newFrame)
{
BYTE *pSeqLength;
unsigned NBytesConsumed, TotalBytes;
// Encode the sequence tag type beginning manually. We'll fill in the
// length after we're done with the rest of the domain parameters.
*Frame = TagType_Sequence;
pSeqLength = Frame + 1;
Frame += 2;
TotalBytes = 2;
// Encode the 8 domain parameters.
EncodeTagBER(pContext, Frame, TagType_Integer, 0,
pDomParams->MaxChannels, &NBytesConsumed, newFrame);
TotalBytes += NBytesConsumed;
Frame = *newFrame;
EncodeTagBER(pContext, Frame, TagType_Integer, 0,
pDomParams->MaxUsers, &NBytesConsumed, newFrame);
TotalBytes += NBytesConsumed;
Frame = *newFrame;
EncodeTagBER(pContext, Frame, TagType_Integer, 0,
pDomParams->MaxTokens, &NBytesConsumed, newFrame);
TotalBytes += NBytesConsumed;
Frame = *newFrame;
EncodeTagBER(pContext, Frame, TagType_Integer, 0,
pDomParams->NumPriorities, &NBytesConsumed, newFrame);
TotalBytes += NBytesConsumed;
Frame = *newFrame;
EncodeTagBER(pContext, Frame, TagType_Integer, 0,
pDomParams->MinThroughput, &NBytesConsumed, newFrame);
TotalBytes += NBytesConsumed;
Frame = *newFrame;
EncodeTagBER(pContext, Frame, TagType_Integer, 0,
pDomParams->MaxDomainHeight, &NBytesConsumed, newFrame);
TotalBytes += NBytesConsumed;
Frame = *newFrame;
EncodeTagBER(pContext, Frame, TagType_Integer, 0,
pDomParams->MaxPDUSize, &NBytesConsumed, newFrame);
TotalBytes += NBytesConsumed;
Frame = *newFrame;
EncodeTagBER(pContext, Frame, TagType_Integer, 0,
pDomParams->ProtocolVersion, &NBytesConsumed, newFrame);
TotalBytes += NBytesConsumed;
Frame = *newFrame;
*pNBytesConsumed = TotalBytes;
*pSeqLength = TotalBytes - 2;
}
/*
* BER-decodes domain parameters. Returns one of the H_... codes defined above.
*/
int DecodeDomainParameters(
PSDCONTEXT pContext, // For tracing.
BYTE *Frame,
unsigned *BytesLeft,
DomainParameters *pDomParams,
BYTE **newFrame)
{
int Result;
unsigned DataLength = 0;
UINT_PTR Data = 0;
// Get sequence indicator and block length.
Result = DecodeTagBER(pContext, Frame, BytesLeft, TagType_Sequence,
&DataLength, &Data, newFrame);
if (Result == H_OK) {
if (*BytesLeft >= DataLength)
Frame = *newFrame;
else
return H_TooShort;
}
else {
return Result;
}
// Get all 8 integer-tag values.
Result = DecodeTagBER(pContext, Frame, BytesLeft, TagType_Integer,
&DataLength, &Data, newFrame);
if (Result == H_OK) {
Frame = *newFrame;
pDomParams->MaxChannels = (unsigned)Data;
}
else {
return Result;
}
Result = DecodeTagBER(pContext, Frame, BytesLeft, TagType_Integer,
&DataLength, &Data, newFrame);
if (Result == H_OK) {
Frame = *newFrame;
pDomParams->MaxUsers = (unsigned)Data;
}
else {
return Result;
}
Result = DecodeTagBER(pContext, Frame, BytesLeft, TagType_Integer,
&DataLength, &Data, newFrame);
if (Result == H_OK) {
Frame = *newFrame;
pDomParams->MaxTokens = (unsigned)Data;
}
else {
return Result;
}
Result = DecodeTagBER(pContext, Frame, BytesLeft, TagType_Integer,
&DataLength, &Data, newFrame);
if (Result == H_OK) {
Frame = *newFrame;
pDomParams->NumPriorities = (unsigned)Data;
}
else {
return Result;
}
Result = DecodeTagBER(pContext, Frame, BytesLeft, TagType_Integer,
&DataLength, &Data, newFrame);
if (Result == H_OK) {
Frame = *newFrame;
pDomParams->MinThroughput = (unsigned)Data;
}
else {
return Result;
}
Result = DecodeTagBER(pContext, Frame, BytesLeft, TagType_Integer,
&DataLength, &Data, newFrame);
if (Result == H_OK) {
Frame = *newFrame;
pDomParams->MaxDomainHeight = (unsigned)Data;
}
else {
return Result;
}
Result = DecodeTagBER(pContext, Frame, BytesLeft, TagType_Integer,
&DataLength, &Data, newFrame);
if (Result == H_OK) {
Frame = *newFrame;
pDomParams->MaxPDUSize = (unsigned)Data;
}
else {
return Result;
}
Result = DecodeTagBER(pContext, Frame, BytesLeft, TagType_Integer,
&DataLength, &Data, newFrame);
if (Result == H_OK) {
Frame = *newFrame;
pDomParams->ProtocolVersion = (unsigned)Data;
}
else {
return Result;
}
return H_OK;
}
/*
* PDU 101
*
* Connect-Initial ::= [APPLICATION 101] IMPLICIT SEQUENCE {
* callingDomainSelector OCTET STRING,
* calledDomainSelector OCTET STRING,
* upwardFlag BOOLEAN,
* targetParameters DomainParameters,
* minimumParameters DomainParameters,
* maximumParameters DomainParameters,
* userData OCTET STRING
* }
*
* Returns FALSE if the in parameters are not acceptable.
*/
BOOLEAN NegotiateDomParams(
PDomain pDomain,
DomainParameters *pTarget,
DomainParameters *pMin,
DomainParameters *pMax,
DomainParameters *pOut)
{
// Maximum channels.
if (pTarget->MaxChannels >= RequiredMinChannels) {
pOut->MaxChannels = pTarget->MaxChannels;
}
else if (pMax->MaxChannels >= RequiredMinChannels) {
pOut->MaxChannels = RequiredMinChannels;
}
else {
ErrOut(pDomain->pContext, "Could not negotiate max channels");
return FALSE;
}
// Maximum users.
if (pTarget->MaxUsers >= RequiredMinUsers) {
pOut->MaxUsers = pTarget->MaxUsers;
}
else if (pMax->MaxUsers >= RequiredMinUsers) {
pOut->MaxUsers = RequiredMinUsers;
}
else {
ErrOut(pDomain->pContext, "Could not negotiate max users");
return FALSE;
}
// Maximum tokens. We don't implement tokens right now, so just take
// the target number and we'll return an error if they try to use them.
//MCS FUTURE: This needs to be negotiated if tokens are implemented.
pOut->MaxTokens = pTarget->MaxTokens;
// Number of data priorities. We accept only one priority.
if (pMin->NumPriorities <= RequiredPriorities) {
pOut->NumPriorities = RequiredPriorities;
}
else {
ErrOut(pDomain->pContext, "Could not negotiate # priorities");
return FALSE;
}
// Minimum throughput. We don't care about this, take whatever.
pOut->MinThroughput = pTarget->MinThroughput;
// Maximum domain height. We only allow a height of 1 in this product.
//MCS FUTURE: This needs to change if we support deeper domains.
if (pTarget->MaxDomainHeight == RequiredDomainHeight ||
pMin->MaxDomainHeight <= RequiredDomainHeight) {
pOut->MaxDomainHeight = RequiredDomainHeight;
}
else {
ErrOut(pDomain->pContext, "Could not negotiate max domain height");
return FALSE;
}
// Max MCS PDU size. Minimum required for headers and lowest X.224
// allowable size. Max was negotiated by X.224.
if (pTarget->MaxPDUSize >= RequiredMinPDUSize) {
if (pTarget->MaxPDUSize <= pDomain->MaxX224DataSize) {
pOut->MaxPDUSize = pTarget->MaxPDUSize;
}
else if (pMin->MaxPDUSize >= RequiredMinPDUSize &&
pMin->MaxPDUSize <= pDomain->MaxX224DataSize) {
// Take maximum possible size as long as we're within range.
pOut->MaxPDUSize = pDomain->MaxX224DataSize;
}
else {
ErrOut(pDomain->pContext, "Could not negotiate max PDU size, "
"sender outside X.224 negotiated limits");
return FALSE;
}
}
else {
if (pMax->MaxPDUSize >= RequiredMinPDUSize) {
pOut->MaxPDUSize = pMax->MaxPDUSize;
}
else {
ErrOut(pDomain->pContext, "Could not negotiate max PDU size, "
"sender max too small");
return FALSE;
}
}
// MCS protocol version. We support only version 2.
if (pTarget->ProtocolVersion == RequiredProtocolVer ||
(pMin->ProtocolVersion <= RequiredProtocolVer &&
pMax->ProtocolVersion >= RequiredProtocolVer)) {
pOut->ProtocolVersion = RequiredProtocolVer;
}
else {
ErrOut(pDomain->pContext, "Could not negotiate protocol version");
return FALSE;
}
return TRUE;
}
BOOLEAN __fastcall HandleConnectInitial(
PDomain pDomain,
BYTE *Frame,
unsigned BytesLeft,
unsigned *pNBytesConsumed)
{
int Result;
BYTE *SaveFrame, *pUserData, *pCPinBuf, *newFrame;
UINT_PTR Data = 0;
NTSTATUS Status;
unsigned DataLength = 0;
unsigned SaveBytesLeft;
unsigned PDULength = 0;
DomainParameters TargetParams, MinParams, MaxParams;
ConnectProviderIndicationIoctl CPin;
if (pDomain->State == State_X224_Connected) {
// Save for error handling below.
SaveBytesLeft = BytesLeft;
newFrame = SaveFrame = Frame;
// Get the PDU length, verify it against BytesLeft.
Result = DecodeTagBER(pDomain->pContext, Frame, &BytesLeft,
TagType_ConnectInitial, &PDULength, NULL, &newFrame);
if (Result == H_OK) {
if (BytesLeft >= PDULength)
Frame = newFrame;
else
return FALSE;
}
else {
goto BadResult;
}
}
else {
ErrOut(pDomain->pContext, "Connect-Initial PDU received when not in "
"state X224_Connected");
MCSProtocolErrorEvent(pDomain->pContext, pDomain->pStat,
Log_MCS_UnexpectedConnectInitialPDU,
Frame, BytesLeft);
// Consume all the data given to us.
*pNBytesConsumed = BytesLeft;
return TRUE;
}
// Decode and skip calling domain selector.
Result = DecodeTagBER(pDomain->pContext, Frame, &BytesLeft,
TagType_OctetString, &DataLength, NULL, &newFrame);
if (Result == H_OK)
Frame = newFrame;
else
goto BadResult;
// Decode and skip called domain selector.
Result = DecodeTagBER(pDomain->pContext, Frame, &BytesLeft,
TagType_OctetString, &DataLength, NULL, &newFrame);
if (Result == H_OK)
Frame = newFrame;
else
goto BadResult;
// Decode Upward boolean.
Result = DecodeTagBER(pDomain->pContext, Frame, &BytesLeft,
TagType_Boolean, &DataLength, &Data, &newFrame);
if (Result == H_OK) {
Frame = newFrame;
CPin.bUpwardConnection = (Data ? TRUE : FALSE);
}
else {
goto BadResult;
}
// Decode target, max, min domain parameters. We will handle internal
// negotiation for these parameters and pass up to the MUX only
// the results, if the negotiation can succeed.
Result = DecodeDomainParameters(pDomain->pContext, Frame, &BytesLeft,
&TargetParams, &newFrame);
if (Result == H_OK)
Frame = newFrame;
else
goto BadResult;
Result = DecodeDomainParameters(pDomain->pContext, Frame, &BytesLeft,
&MinParams, &newFrame);
if (Result == H_OK)
Frame = newFrame;
else
goto BadResult;
Result = DecodeDomainParameters(pDomain->pContext, Frame, &BytesLeft,
&MaxParams, &newFrame);
if (Result == H_OK)
Frame = newFrame;
else
goto BadResult;
// Get the user data (an octet string). After this Frame should point to
// the end of the user data.
Result = DecodeTagBER(pDomain->pContext, Frame, &BytesLeft,
TagType_OctetString, &CPin.UserDataLength, &Data, &newFrame);
if (Result == H_OK) {
Frame = newFrame;
pUserData = (BYTE *)Data;
*pNBytesConsumed = SaveBytesLeft - BytesLeft;
}
else {
goto BadResult;
}
// Check maximum user data size.
if (CPin.UserDataLength > MaxGCCConnectDataLength) {
POUTBUF pOutBuf;
ICA_CHANNEL_COMMAND Command;
ErrOut(pDomain->pContext, "HandleConnectInitial(): Attached user data "
"is too large, returning error and failing connection");
// Alloc OutBuf for sending PDU.
// This allocation is vital to the session and must succeed.
do {
Status = IcaBufferAlloc(pDomain->pContext, FALSE, TRUE,
ConnectResponseHeaderSize, NULL, &pOutBuf);
if (Status != STATUS_SUCCESS)
ErrOut(pDomain->pContext, "Could not allocate an OutBuf for a "
"connect-response PDU, retrying");
} while (Status != STATUS_SUCCESS);
// Fill in PDU.
// Encode PDU header. Param 2, the called connect ID, does not need to
// be anything special because we do not allow extra sockets to be
// opened for other data priorities.
CreateConnectResponseHeader(pDomain->pContext,
RESULT_UNSPECIFIED_FAILURE, 0, &pDomain->DomParams, 0, pOutBuf->pBuffer,
&pOutBuf->ByteCount);
// Send the PDU.
Status = SendOutBuf(pDomain, pOutBuf);
if (!NT_SUCCESS(Status)) {
ErrOut(pDomain->pContext, "Could not send connect-response PDU "
"to TD");
// Ignore error -- this should only occur if stack is going down.
return TRUE;
}
// Signal that we need to drop the link.
Command.Header.Command = ICA_COMMAND_BROKEN_CONNECTION;
Command.BrokenConnection.Reason = Broken_Unexpected;
Command.BrokenConnection.Source = BrokenSource_Server;
Status = IcaChannelInput(pDomain->pContext, Channel_Command,
0, NULL, (BYTE *)&Command, sizeof(Command));
if (!NT_SUCCESS(Status))
ErrOut(pDomain->pContext, "HandleConnectInitial(): Could not "
"send BROKEN_CONN upward");
return TRUE;
}
// Domain parameters negotiation.
if (NegotiateDomParams(pDomain, &TargetParams, &MinParams, &MaxParams,
&CPin.DomainParams)) {
pDomain->DomParams = CPin.DomainParams;
}
else {
MCSProtocolErrorEvent(pDomain->pContext, pDomain->pStat,
Log_MCS_UnnegotiableDomainParams,
Frame, BytesLeft);
return TRUE;
}
// Calculate the MaxSendSize. This is the maximum PDU size minus the
// maximum possible number of bytes for MCS headers and ASN.1
// segmentation.
pDomain->MaxSendSize = CPin.DomainParams.MaxPDUSize - 6 -
GetTotalLengthDeterminantEncodingSize(
CPin.DomainParams.MaxPDUSize);
// Fill in remaining CPin fields and send to MCSMUX
// MCS FUTURE: hConn should point to a real Connection object.
CPin.Header.hUser = NULL; // Signals node controller traffic.
CPin.Header.Type = MCS_CONNECT_PROVIDER_INDICATION;
CPin.hConn = (PVOID) 1; // Non-NULL so we know this is remote connection.
RtlCopyMemory(CPin.UserData, pUserData, CPin.UserDataLength);
// Set state for this connection, we are waiting for a reply from NC.
pDomain->State = State_ConnectProvIndPending;
ASSERT(pDomain->bChannelBound);
TraceOut(pDomain->pContext, "HandleConnectInitial(): Sending "
"CONNECT_PROVIDER_IND upward");
Status = IcaChannelInput(pDomain->pContext, Channel_Virtual,
Virtual_T120ChannelNum, NULL, (BYTE *)&CPin, sizeof(CPin));
if (!NT_SUCCESS(Status)) {
ErrOut(pDomain->pContext, "ChannelInput failed on "
"connect-provider indication");
// Ignore errors here. This should only happen if stack is going down.
return TRUE;
}
return TRUE;
BadResult:
if (Result == H_TooShort)
return FALSE;
// Must be H_BadContents.
ErrOut(pDomain->pContext, "HandleConnectInitial(): Could not parse PDU, "
"returning PDU reject");
ReturnRejectPDU(pDomain, Diag_InvalidBEREncoding, SaveFrame,
SaveBytesLeft - BytesLeft);
MCSProtocolErrorEvent(pDomain->pContext, pDomain->pStat,
Log_MCS_ConnectPDUBadPEREncoding,
Frame, BytesLeft);
// Attempt to skip the entire PDU.
*pNBytesConsumed = SaveBytesLeft;
// Return FALSE to force the caller to fail.
return FALSE;
}
/*
* PDU 102
*
* Connect-Response ::= [APPLICATION 102] IMPLICIT SEQUENCE {
* result Result,
* calledConnectId INTEGER (0..MAX),
* domainParameters DomainParameters,
* userData OCTET STRING
* }
*/
// pBuffer is assumed to point to a buffer of at least size given
// by macro ConnectResponseHeaderSize; X.224 header will start here.
// Actual number of bytes used for the encoding is returned in
// *pNBytesConsumed.
// We do not encode the user data, but instead just the header, which
// allows some optimization by allowing the header to be encoded
// and copied to the beginning of user data.
void CreateConnectResponseHeader(
PSDCONTEXT pContext, // For tracing.
MCSResult Result,
int CalledConnectID,
DomainParameters *pDomParams,
unsigned UserDataLength,
BYTE *pBuffer,
unsigned *pNBytesConsumed)
{
BYTE *OutFrame, *newFrame;
unsigned NBytesConsumed, TotalSize, EncodeLength;
// Set up for creating the PDU.
OutFrame = pBuffer + X224_DataHeaderSize;
NBytesConsumed = 0;
// Encode the BER prefix, PDU type, and leave space for the PDU length.
// Note that the length is the number of bytes following this length
// indicator.
// The most-oft-encountered case is where the PDU length is less than 128
// bytes. So, special-case larger sizes at the end of the function
// when we know the total size.
OutFrame[0] = MCS_CONNECT_PDU;
OutFrame[1] = MCS_CONNECT_RESPONSE_ENUM;
// Skip OutFrame[2] for the default 1-byte (<= 128) size.
OutFrame += 3;
TotalSize = 3;
// Encode Result, CalledConnectID, DomParams. We use OutFrame
// as a current pointer.
EncodeTagBER(pContext, OutFrame, TagType_Enumeration, 0, Result,
&NBytesConsumed, &newFrame);
TotalSize += NBytesConsumed;
OutFrame = newFrame;
EncodeTagBER(pContext, OutFrame, TagType_Integer, 0, CalledConnectID,
&NBytesConsumed, &newFrame);
TotalSize += NBytesConsumed;
OutFrame = newFrame;
EncodeDomainParameters(pContext, OutFrame, &NBytesConsumed, pDomParams,
&newFrame);
TotalSize += NBytesConsumed;
OutFrame = newFrame;
// Encode only the length bytes, not the user data body.
EncodeTagBER(pContext, OutFrame, TagType_OctetString, UserDataLength,
(UINT_PTR)NULL, &NBytesConsumed, &newFrame);
TotalSize += NBytesConsumed;
OutFrame = newFrame;
// Encode the final size. Here we special-case a too-large size by
// shifting data around. The large size is the exceptional case.
EncodeLength = TotalSize - 3 + UserDataLength;
if (EncodeLength < 128) {
pBuffer[2 + X224_DataHeaderSize] = (BYTE)EncodeLength;
}
else {
unsigned i, Len = 0;
WarnOut(pContext, "CreateConnRespHeader(): Perf hit from too-large "
"PDU size");
// Since we can only send up to 64K bytes, the length determinant
// cannot be any more than 3 bytes long.
ASSERT(EncodeLength < 65535);
if (EncodeLength < 0x8000)
Len = 2;
else if (EncodeLength < 0x800000)
Len = 3;
else
ASSERT(FALSE);
// Size escape comes first.
pBuffer[2 + X224_DataHeaderSize] = LengthModifier_2 + Len - 2;
RtlMoveMemory(pBuffer + 3 + X224_DataHeaderSize + Len,
pBuffer + 3 + X224_DataHeaderSize, EncodeLength - 3);
for (i = 1; i <= Len; i++) {
pBuffer[3 + X224_DataHeaderSize + Len - i] = (BYTE)EncodeLength;
EncodeLength >>= 8;
}
// We already included one byte of the length encoding above, but
// now we need to also skip the length escape and the encoded length.
TotalSize += Len;
}
// Set up X224 header based on the final size of the packet.
CreateX224DataHeader(pBuffer, TotalSize + UserDataLength, TRUE);
*pNBytesConsumed = X224_DataHeaderSize + TotalSize;
}
#ifdef MCS_Future
BOOLEAN __fastcall HandleConnectResponse(
PDomain pDomain,
BYTE *Frame,
unsigned BytesLeft,
unsigned *pNBytesConsumed)
{
//MCS FUTURE: This will be needed to handle the future case where we initiate
//connections for joins/invites.
ErrOut(pDomain->pContext, "Connect Response PDU received, "
"this should never happen");
MCSProtocolErrorEvent(pDomain->pContext, pDomain->pStat,
Log_MCS_UnsupportedConnectPDU,
Frame, BytesLeft);
// Consume all the data given to us.
*pNBytesConsumed = BytesLeft;
return TRUE;
}
#endif // MCS_Future
/*
* PDU 103
*
* Connect-Additional ::= [APPLICATION 103] IMPLICIT SEQUENCE {
* calledConnectId INTEGER (0..MAX),
* dataPriority DataPriority
* }
*
* No Create() funcion, we never expect to initiate these PDUs.
*
* We do not handle these PDUs for this Hydra release, since in the Citrix
* framework there can be only one connection at a time. Domain parameters
* should have been negotiated to only one connection handling all SendData
* priorities.
*/
#ifdef MCS_Future
BOOLEAN __fastcall HandleConnectAdditional(
PDomain pDomain,
BYTE *Frame,
unsigned BytesLeft,
unsigned *pNBytesConsumed)
{
ErrOut(pDomain->pContext, "Connect-additional PDU received, "
"this should never happen");
MCSProtocolErrorEvent(pDomain->pContext, pDomain->pStat,
Log_MCS_UnsupportedConnectPDU,
Frame, BytesLeft);
// Consume all the data given to us.
*pNBytesConsumed = BytesLeft;
return TRUE;
}
#endif // MCS_Future
/*
* PDU 104
*
* Connect-Result ::= [APPLICATION 104] IMPLICIT SEQUENCE {
* result Result
* }
*
* No Create() function, we never expect to initiate these PDUs.
*
* We do not handle these PDUs for this Hydra release, since in the Citrix
* framework there can be only one connection at a time.
*/
#ifdef MCS_Future
BOOLEAN __fastcall HandleConnectResult(
PDomain pDomain,
BYTE *Frame,
unsigned BytesLeft,
unsigned *pNBytesConsumed)
{
ErrOut(pDomain->pContext, "Connect-result PDU received, "
"this should never happen");
MCSProtocolErrorEvent(pDomain->pContext, pDomain->pStat,
Log_MCS_UnsupportedConnectPDU,
Frame, BytesLeft);
// Consume all the data given to us.
*pNBytesConsumed = BytesLeft;
return TRUE;
}
#endif // MCS_Future