SRVHSHAK.C
/******************************************************************************\
* This is a part of the Microsoft Source Code Samples.
* Copyright 1995 - 1997 Microsoft Corporation.
* All rights reserved.
* This source code is only intended as a supplement to
* Microsoft Development Tools and/or WinHelp documentation.
* See these sources for detailed information regarding the
* Microsoft samples programs.
\******************************************************************************/
/*++
Copyright (c) 1997 Microsoft Corporation
Module Name:
SrvHShak.c
Abstract:
The server component of Remote. Handshake with
client at start of session.
Author:
Dave Hart 30 May 1997
Environment:
Console App. User mode.
Revision History:
--*/
#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <io.h>
#include <string.h>
#include "Remote.h"
#include "Server.h"
VOID
FASTCALL
HandshakeWithRemoteClient(
PREMOTE_CLIENT pClient
)
{
pClient->ServerFlags |= SFLG_HANDSHAKING;
AddClientToHandshakingList(pClient);
//
// Read hostname from client
//
ZeroMemory(
&pClient->ReadOverlapped,
sizeof(pClient->ReadOverlapped)
);
if ( ! ReadFileEx(
pClient->PipeReadH,
pClient->Name,
HOSTNAMELEN - 1,
&pClient->ReadOverlapped,
ReadClientNameCompleted
)) {
CloseClient(pClient);
}
}
VOID
WINAPI
ReadClientNameCompleted(
DWORD dwError,
DWORD cbRead,
LPOVERLAPPED lpO
)
{
PREMOTE_CLIENT pClient;
SESSION_STARTREPLY ssr;
pClient = CONTAINING_RECORD(lpO, REMOTE_CLIENT, ReadOverlapped);
if (pClient->ServerFlags & SFLG_CLOSING) {
return;
}
if (dwError) {
CloseClient(pClient);
return;
}
if ((HOSTNAMELEN - 1) != cbRead) {
printf("ReadClientNameCompleted read %d s/b %d.\n", cbRead, (HOSTNAMELEN - 1));
CloseClient(pClient);
return;
}
//
// The client name read is 15 bytes always. The last four
// should match MAGICNUMBER, which conveniently has the
// low byte zeroed to terminate the client name after 11
// characters.
//
if (MAGICNUMBER != *(DWORD *)&pClient->Name[11]) {
pClient->Name[11] = 0;
CloseClient(pClient);
return;
}
//
// Now we can tell if this is a single-pipe or two-pipe
// client, because single-pipe clients replace the
// first byte of the computername with the illegal
// character '?'.
//
if ('?' == pClient->Name[0]) {
pClient->PipeWriteH = pClient->PipeReadH;
TRACE(CONNECT, ("Client %d pipe %x is single-pipe.\n", pClient->dwID, pClient->PipeWriteH));
//
// In order for things to work reliably for 2-pipe clients
// when there are multiple remote servers on the same pipename,
// we need to tear down the listening OUT pipe and recreate it so
// that the oldest listening IN pipe will be from the same process
// as the oldest listening OUT pipe.
//
if (1 == cConnectIns) {
TRACE(CONNECT, ("Recycling OUT pipe %x as well for round-robin behavior.\n",
hPipeOut));
CANCELIO(hPipeOut);
DisconnectNamedPipe(hPipeOut);
CloseHandle(hPipeOut);
hPipeOut = INVALID_HANDLE_VALUE;
bOutPipeConnected = FALSE;
CreatePipeAndIssueConnect(OUT_PIPE);
}
} else {
if ( ! bOutPipeConnected ) {
printf("Remote: %x two-pipe client connected to IN pipe but not OUT?\n", pClient);
CloseClient(pClient);
return;
}
bOutPipeConnected = FALSE;
if (INVALID_HANDLE_VALUE != hConnectOutTimer) {
pfnCancelWaitableTimer(hConnectOutTimer);
}
pClient->PipeWriteH = hPipeOut;
hPipeOut = INVALID_HANDLE_VALUE;
TRACE(CONNECT, ("Client %d is dual-pipe IN %x OUT %x.\n", pClient->dwID, pClient->PipeReadH, pClient->PipeWriteH));
CreatePipeAndIssueConnect(OUT_PIPE);
}
TRACE(SHAKE, ("Read client name %s\n", pClient->Name));
//
// Send our little pile of goodies to the client
//
ssr.MagicNumber = MAGICNUMBER;
ssr.Size = sizeof(ssr);
ssr.FileSize = dwWriteFilePointer;
//
// Copy ssr structure to a buffer that will be around
// for the entire I/O.
//
CopyMemory(pClient->WriteBuffer, &ssr, sizeof(ssr));
if ( ! WriteFileEx(
pClient->PipeWriteH,
pClient->WriteBuffer,
sizeof(ssr),
&pClient->WriteOverlapped,
WriteServerReplyCompleted
)) {
CloseClient(pClient);
}
}
VOID
WINAPI
WriteServerReplyCompleted(
DWORD dwError,
DWORD cbWritten,
LPOVERLAPPED lpO
)
{
PREMOTE_CLIENT pClient;
pClient = CONTAINING_RECORD(lpO, REMOTE_CLIENT, WriteOverlapped);
if (pClient->ServerFlags & SFLG_CLOSING) {
return;
}
if (HandleSessionError(pClient, dwError)) {
return;
}
TRACE(SHAKE, ("Wrote server reply\n"));
//
// Read the size of the SESSION_STARTUPINFO the client is
// sending us, to deal gracefully with different versions
// on client and server.
//
if ( ! ReadFileEx(
pClient->PipeReadH,
pClient->ReadBuffer,
sizeof(DWORD),
&pClient->ReadOverlapped,
ReadClientStartupInfoSizeCompleted
)) {
CloseClient(pClient);
}
}
VOID
WINAPI
ReadClientStartupInfoSizeCompleted(
DWORD dwError,
DWORD cbRead,
LPOVERLAPPED lpO
)
{
PREMOTE_CLIENT pClient;
DWORD dwSize;
pClient = CONTAINING_RECORD(lpO, REMOTE_CLIENT, ReadOverlapped);
if (HandleSessionError(pClient, dwError)) {
return;
}
if (cbRead != sizeof(DWORD)) {
CloseClient(pClient);
return;
}
//
// Sanity check the size
//
dwSize = *(DWORD *)pClient->ReadBuffer;
if (dwSize > 1024) {
CloseClient(pClient);
return;
}
//
// Squirrel away the size in the write buffer,
// since during handshaking we never have both a
// read and write pending this is OK.
//
*(DWORD *)pClient->WriteBuffer = dwSize;
TRACE(SHAKE, ("Read client reply size %d\n", dwSize));
//
// Read the rest of the SESSION_STARTUPINFO into the read buffer
// after the size.
//
RtlZeroMemory(
&pClient->ReadOverlapped,
sizeof(pClient->ReadOverlapped)
);
if ( ! ReadFileEx(
pClient->PipeReadH,
pClient->ReadBuffer + sizeof(DWORD),
dwSize - sizeof(DWORD),
&pClient->ReadOverlapped,
ReadClientStartupInfoCompleted
)) {
CloseClient(pClient);
}
}
VOID
WINAPI
ReadClientStartupInfoCompleted(
DWORD dwError,
DWORD cbRead,
LPOVERLAPPED lpO
)
{
PREMOTE_CLIENT pClient;
DWORD dwSize;
SESSION_STARTUPINFO ssi;
char Buf[256];
pClient = CONTAINING_RECORD(lpO, REMOTE_CLIENT, ReadOverlapped);
if (HandleSessionError(pClient, dwError)) {
return;
}
dwSize = *(DWORD *)pClient->WriteBuffer;
if (cbRead != (dwSize - sizeof(ssi.Size))) {
CloseClient(pClient);
return;
}
CopyMemory(&ssi, pClient->ReadBuffer, min(dwSize, sizeof(ssi)));
CopyMemory(pClient->Name, ssi.ClientName, sizeof(pClient->Name));
pClient->Flag = ssi.Flag;
if (ssi.Version != VERSION) {
printf("Remote Warning: Server Version=%d Client Version=%d for %s\n", VERSION, ssi.Version, pClient->Name);
}
TRACE(SHAKE, ("Read client info, new name %s, %d lines\n", pClient->Name, ssi.LinesToSend));
//
// Set temp file position according to the client's
// requested lines to send. The heuristic of 45 chars
// per average line is used by the client. However since old clients
// hardcode this knowledge and sit and spin trying to read that many
// bytes before completing initialization, and because we might not send
// that many due to stripping BEGINMARK and ENDMARK characters, we
// use 50 chars per line to calculate the temp file position in hopes
// the extra bytes will overcome the missing MARK characters.
//
pClient->dwFilePos = dwWriteFilePointer > (ssi.LinesToSend * 50)
? dwWriteFilePointer - (ssi.LinesToSend * 50)
: 0;
//
// This client's ready to roll.
//
pClient->ServerFlags &= ~SFLG_HANDSHAKING;
MoveClientToNormalList(pClient);
//
// Start read operation against this client's input.
//
StartReadClientInput(pClient);
//
// Announce the connection.
//
sprintf(Buf,
"\n**Remote: Connected to %s %s%s [%s]\n",
pClient->Name,
pClient->UserName,
(pClient->PipeReadH != pClient->PipeWriteH)
? " (two pipes)"
: "",
GetFormattedTime(TRUE));
if (WriteFileSynch(hWriteTempFile,Buf,strlen(Buf),&dwSize,dwWriteFilePointer,&olMainThread)) {
dwWriteFilePointer += dwSize;
StartServerToClientFlow();
}
//
// Start write cycle for client output from the temp
// file.
// not needed because of StartServerToClientFlow() just above
// StartReadTempFile(pClient);
}