/*
Copyright (C) 1996

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

The author can be contacted via Email at bmorin@wpi.edu
*/
#include "text_t.h"
#include <windows.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <memory.h>
#pragma hdrstop
#include "parse.h"
#include "netio.h"
#include "settings.h"
#include "httpreq.h" //Had to put myself here because of the global types...
#include "httpsrv.h"
#include "httpsend.h"
#include "cgiwrapper.h"

/*
Implementation Notes:

HTTP field names, method and version strings are converted to upper case
right after being read from the client in order to allow case insensitive
string comparisons to be done on them.  Since these fields are worked with a
lot, this should help performance.
*/

//Private Data and declarations
#define IO_BUFFER_SIZE 16384        //16K IO Buffer
#define MAX_HTTP_LINE_LEN 1024      //Max length of line in a header of 1024
#define MAX_HTTP_FIELD_NAME_LEN 128 //Max length of name field in line
#define MAX_HTTP_FIELD_LEN 1024     //Max length of data in line

//Private Function Declarations with Return Contstants

/*
Function Name: DispatchRequest
Purpose: Manages having the request parsed, then sent to the right function
         to send a response or handle an error.
Parameters:
         ClientSocket - Socket the client is on
	 ClientSockAddr - Address of client
	 AddrLen - Length of address of client
	 IOBuffer - Pointer to buffer allocated for IO operations
	 ThreadNum - Number of thread that called this function for debugging purposes
Notes:   I'm still playing with the keep alive support.  I commented out
	 the stuff for giving a client a timeout because I was unable to detect
	 disconnects.
More Notes: Not sure if this organization will allow me to easily add support
	    for ISAPI filter DLLs.
*/
void DispatchRequest(SOCKET ClientSocket, SOCKADDR_IN ClientSockAddr, int AddrLen, BYTE *IOBuffer);

/*
Function Name: Get HTTP Headers
Purpose: Manages having the request parsed, then sent to the right function
         to send a response or handle an error.
Parameters:
	RequestInfo - Request information structure (see httpreq.h)
	RequestFields - HTTP request fields structure (see httpreq.h)
Returns: GH_ERROR on error (diconnect, bad data, Windows in a bad mood, etc.)
			GH_UNKNOWN_VERSION if the version number is not HTTP/0.9 or HTTP/1.x
			GH_SIMPLE_REQUEST on a properly formated HTTP/0.9 request
			GH_10_REQUEST on a properly formated HTTP/1.x request
*/
int GetHTTPHeaders(RequestInfoT &RequestInfo, RequestFieldsT &RequestFields);
#define GH_ERROR           -1
#define GH_UNKNOWN_VERSION  0
#define GH_SIMPLE_REQUEST   1
#define GH_10_REQUEST       2

/*
Function Name: Clean Up HTTP Headers
Purpose: Cleans up memory dynamicly allocated for headers
Parameters:
	RequestInfo - Request information structure (see httpreq.h)
	RequestFields - HTTP request fields structure (see httpreq.h)
Returns: Nothing
*/
void CleanUpHTTPHeaders(RequestInfoT &RequestInfo, RequestFieldsT &RequestFields);

/*
Function Name: Split Query
Purpose: Splits the file and query part of a URI.  In other words, it
	 puts the parts before and after the "?" in differnet strings.
Parameters:
	 URIStr - The requested URI
	 FileStr - String to contain the name of the path + file part of the URI
	 QueryStr - String to contain the query part of the URI
Returns: TRUE if there is a query, else FALSE
*/
BOOL SplitQuery(char *URIStr, char *FileStr, char *QueryStr, int ThreadNum);

/*
Function Name: Get File
Purpose: Attempts to find a given file, including looking for index.html.
	 Updates the given URI string so it points to the true document location
Parameters:
	 FilePath - Path of file, may be modified to best reflect the retrived file
				  or directory
	 URIStr - URI string, minus the query
Returns: GF_ERROR on error
			GF_FILE_FOUND on success
			GF_INDEX_FOUND if file is a directory with an index.html file in it
			GF_DIRECTORY if file is a directory
			GF_FILE_NOT_FOUND if file was found
*/

/*
Function Name: Process Simple Request
Purpose: Sends a reply to a HTTP 0.9 "simple" request
Parameters:
	ClientSocket - Socket the client is on
	RequestInfo - Structure storing the parsed headers
	IOBuffer - Pointer to buffer allocated for IO operations
	TheadNum - Number of calling thread for debugging
Notes: I should really test this and see if it works...
*/
void ProcessSimpleRequest(RequestInfoT &RequestInfo, RequestFieldsT &RequestFields);

//Public Functions
/******************************************************************************/
void RequestThread(RequestThreadMessageT *Parameters) {
  SOCKADDR_IN ClientSockAddr;
  SOCKET ClientSocket;
  int AddrLen;
  //Allocate an IO buffer for this thread
  BYTE *IOBuffer = new BYTE[IO_BUFFER_SIZE];

  //Get the parameters for the request
  ClientSocket = Parameters->ClientSocket;
  ClientSockAddr = Parameters->ClientSockAddr;
  AddrLen = Parameters->AddrLen;
  DispatchRequest(ClientSocket, ClientSockAddr, AddrLen, IOBuffer);
}
/******************************************************************************/

//Private Functions

/******************************************************************************/
void DispatchRequest(SOCKET ClientSocket, SOCKADDR_IN ClientSockAddr, int AddrLen,  BYTE *IOBuffer) {
  RequestInfoT RequestInfo;
  RequestFieldsT RequestFields;

  // TrayAddConnection();

  //Setup the RequestInfo structure
  memset(&RequestInfo, 0, sizeof(RequestInfoT));
  RequestInfo.ThreadNum = 0;
  RequestInfo.IOBuffer = IOBuffer;
  RequestInfo.IOBufferSize = IO_BUFFER_SIZE;
  RequestInfo.ClientSocket = ClientSocket;
  RequestInfo.ClientSockAddr = ClientSockAddr;
  RequestInfo.AddrLen = AddrLen;
  RequestInfo.KeepAlive = FALSE;
  
  int GetHeadersResult;
  do {
    //Get Headers
    GetHeadersResult = GetHTTPHeaders(RequestInfo, RequestFields);
    //Figure out what version we're dealing with and deal with it
    switch (GetHeadersResult) {
    case GH_SIMPLE_REQUEST :
      SendHTTPError(400, "HTTP Request not supported", "Only 1.x requests supported", RequestInfo, RequestFields);
      // TrayIncNumServed();
      break;
    case GH_10_REQUEST :
      ExamineURIStr(RequestFields.URIStr,&RequestInfo,&RequestFields);
      // TrayIncNumServed();
      break;
    case GH_UNKNOWN_VERSION :
      SendHTTPError(400, "HTTP Version not supported", "Only 1.x requests supported", RequestInfo, RequestFields);
      // TrayIncNumServed();
      break;
    case GH_ERROR:
      //Disconnect
      RequestInfo.KeepAlive = FALSE;
      break;
    }
    CleanUpHTTPHeaders(RequestInfo, RequestFields);
  } while (0/*RequestInfo.KeepAlive == TRUE*/);
  //Close connection
  CloseSocket(RequestInfo.ClientSocket);
  // TrayRemoveConnection();
}

/******************************************************************************/
int GetHTTPHeaders(RequestInfoT &RequestInfo, RequestFieldsT &RequestFields) {
  //Parsing and IO buffers
  char CurLine[NETIO_MAX_LINE];
  char NextLine[NETIO_MAX_LINE];
  char FieldNameStr[MAX_HTTP_FIELD_NAME_LEN];
  char FieldValStr[MAX_HTTP_FIELD_LEN];
  
  //Parsing and IO working vars
  int ReadBufferIndex;
  int DataInBuffer;
  int Start;
  int End;
  int Len;

  //Clear all the fields
  memset(&RequestFields, 0, sizeof(RequestFieldsT));

  ReadBufferIndex = 0;
  DataInBuffer = 0;
  
  //Get First Line
  if (GetLine(CurLine, RequestInfo.ClientSocket, RequestInfo.IOBuffer,
	      RequestInfo.IOBufferSize, ReadBufferIndex, DataInBuffer,
	      RequestInfo.ThreadNum) != 0) return GH_ERROR;
  do {//Get Next Line, append it if the first charactor is space
    if(GetLine(NextLine, RequestInfo.ClientSocket, RequestInfo.IOBuffer,
	       RequestInfo.IOBufferSize, ReadBufferIndex, DataInBuffer,
	       RequestInfo.ThreadNum) != 0) return GH_ERROR;
    if ((NextLine[0] == ' ') || (NextLine[0] == '\t'))
      strcat(CurLine, NextLine);
  } while ((NextLine[0] == ' ') || (NextLine[0] == '\t'));
  //Method String (first word)
  Start = 0;
  GetWord(RequestFields.MethodStr, CurLine, Start, End);
  CharUpper(RequestFields.MethodStr);
  
  //Version String (last word)
  GetLastWord(RequestFields.VersionStr, CurLine, Start);
  CharUpper(RequestFields.VersionStr);

  if (strncmp(RequestFields.VersionStr, "HTTP/", 5) != 0) {
    //No version, assume simple request
    //part after method is URI
    memcpy(RequestFields.URIStr, CurLine + End, strlen(CurLine) + 1 - End);
    return GH_SIMPLE_REQUEST;
  }

  //URI String (in between End of first and Start of last)
  //<Method> <WhiteSpace> <URI> <WhiteSpace> <Version> <CRLF>
  //                  End^             Start^
  int URIStrLen = Start - End;;
  if (URIStrLen > ReqURIStrLen-1) URIStrLen = ReqURIStrLen - 1;
  memcpy(RequestFields.URIStr, CurLine + End, URIStrLen);
  RequestFields.URIStr[URIStrLen] = 0;
  TrimRight(RequestFields.URIStr); //Remove trailing space
  
  //Only accept requests from HTTP/0.9 or HTTP/1.X clients, we'll
  //assume that anything else will require an upgrade or patch
  if (strncmp(RequestFields.VersionStr, "HTTP/1.", 7) != 0)
    return GH_UNKNOWN_VERSION;
  
  //Get the rest of the lines
  
  strcpy(CurLine, NextLine);
  
  while (CurLine[0] != 0) {//Blank Line, we're done
    do {//Get Next Line, append it if the first charactor is space
      if (GetLine(NextLine, RequestInfo.ClientSocket, RequestInfo.IOBuffer,
		  RequestInfo.IOBufferSize, ReadBufferIndex, DataInBuffer,
		  RequestInfo.ThreadNum) != 0)
	return GH_ERROR;
      if ((NextLine[0] == ' ') || (NextLine[0] == '\t'))
	strcat(CurLine, NextLine);
    } while ((NextLine[0] == ' ') || (NextLine[0] == '\t'));
    
    Start = 0;
    GetWord(FieldNameStr, CurLine, Start, End);
    CharUpper(FieldNameStr);
    
    Len = strlen(CurLine) - End;
    memcpy(FieldValStr, CurLine + End, Len);
    FieldValStr[Len] = 0;
    
    //Process it
    //In order of expected commonality
    //All constants are in canonized, thus in upper case and case sensitive
    //comparisons are used
    //--Just About Always--
    if (strcmp("ACCEPT:", FieldNameStr) == 0) {
      if (RequestFields.AcceptStr[0] == '\0') {
        strncpy(RequestFields.AcceptStr, FieldValStr, ReqAcceptStrLen - 1);
	//  		if (Len >= ReqAcceptStrLen)
	//        if (log_debug) log_message("Accept field truncated");
      }
      else {
       	//Append it with a comma
        int AcceptStrLen = strlen(RequestFields.AcceptStr);
        if ((ReqAcceptStrLen - AcceptStrLen) >= 10) {
          strncat(RequestFields.AcceptStr, ", ", ReqAcceptStrLen - AcceptStrLen - 1);
          strncat(RequestFields.AcceptStr, FieldValStr, ReqAcceptStrLen - AcceptStrLen - 3);
	}
      }
    }
    else if (strcmp("DATE:", FieldNameStr) == 0) {
      strncpy(RequestFields.DateStr, FieldValStr, ReqDateStrLen - 1);
      //			if (Len >= ReqDateStrLen) LogError("Date field truncated");
    }
    else if (strcmp("USER-AGENT:", FieldNameStr) == 0) {
      strncpy(RequestFields.UserAgentStr, FieldValStr, ReqUserAgentStrLen - 1);
      //			if (Len >= ReqUserAgentStrLen) {
      //         	LogError("User Agent field truncated, value follows");
      //            LogError(RequestFields.UserAgentStr);
      //            }
    }
    else if (strcmp("CONNECTION:", FieldNameStr) == 0) {
      strncpy(RequestFields.ConnectionStr, FieldValStr, ReqConnectionStrLen - 1);
      //			if (Len >= ReqConnectionStrLen) LogError("Connection field truncated");
    }
    //--Sometimes--
    else if (strcmp("ACCEPT-LANGUAGE:", FieldNameStr) == 0) {
      strncpy(RequestFields.AcceptLangStr, FieldValStr, ReqAcceptLangStrLen - 1);
      //			if (Len >= ReqAcceptLangStrLen) LogError("Accept-Language field truncated");
    }
    else if (strcmp("REFERER:", FieldNameStr) == 0) {
      strncpy(RequestFields.RefererStr, FieldValStr, ReqRefererStrLen - 1);
      //			if (Len >= ReqRefererStrLen) LogError("Referer field truncated");
    }
    else if (strcmp("IF-MODIFIED-SINCE:", FieldNameStr) == 0) {
      strncpy(RequestFields.IfModSinceStr, FieldValStr, ReqIfModSinceStrLen - 1);
      //			if (Len >= ReqIfModSinceStrLen) LogError("If Modified Since field truncated");
    }
    //--Uncommon--
    else if (strcmp("FROM:", FieldNameStr) == 0) {
      strncpy(RequestFields.FromStr, FieldValStr, ReqFromStrLen - 1);
      //			if (Len >= ReqFromStrLen) LogError("From field truncated");
    }
    else if (strcmp("MIME-VERSION:", FieldNameStr) == 0) {
      strncpy(RequestFields.MIMEVerStr, FieldValStr, ReqMIMEVerStrLen - 1);
      //			if (Len >= ReqMIMEVerStrLen) LogError("MIME Version field truncated");
    }
    else if (strcmp("PRAGMA:", FieldNameStr) == 0) {
      strncpy(RequestFields.PragmaStr, FieldValStr, ReqPragmaStrLen - 1);
      //			if (Len >= ReqPragmaStrLen) LogError("Pragma field truncated");
    }
    //--Special case--
    else if (strcmp("AUTHORIZATION:", FieldNameStr) == 0) {
      strncpy(RequestFields.AuthorizationStr, FieldValStr, ReqAuthorizationStrLen - 1);
      //			if (Len >= ReqAuthorizationStrLen) LogError("Authorization field truncated");
    }
    else if (strcmp("CONTENT-LENGTH:", FieldNameStr) == 0) {
      strncpy(RequestFields.ContentLengthStr, FieldValStr, ReqContentLengthStrLen - 1);
      //			if (Len >= ReqContentLengthStrLen) LogError("Content Length field truncated");
    }
    else if (strcmp("CONTENT-TYPE:", FieldNameStr) == 0) {
      strncpy(RequestFields.ContentTypeStr, FieldValStr, ReqContentTypeStrLen - 1);
      //			if (Len >= ReqContentTypeStrLen) LogError("Content Type field truncated");
    }
    else if (strcmp("CONTENT-ENCODING:", FieldNameStr) == 0) {
      strncpy(RequestFields.ContentEncodingStr, FieldValStr, ReqContentEncodingStrLen - 1);
      //			if (Len >= ReqContentEncodingStrLen) LogError("Content Encoding field truncated");
    }
    else {
      //Add it to the other headers
      int VarLen = strlen(FieldNameStr);
      if (FieldNameStr[VarLen - 1] == ':') {
	//Remove the colon
	FieldNameStr[VarLen - 1] = '\0';
	VarLen--;
      }
      RequestFields.OtherHeaders[RequestFields.NumOtherHeaders].Var = new char[VarLen + 1];
      RequestFields.OtherHeaders[RequestFields.NumOtherHeaders].Val = new char[Len + 1];
      strcpy(RequestFields.OtherHeaders[RequestFields.NumOtherHeaders].Var, FieldNameStr);
      strcpy(RequestFields.OtherHeaders[RequestFields.NumOtherHeaders].Val, FieldValStr);
      RequestFields.NumOtherHeaders++;
    }
    strcpy(CurLine, NextLine);
  }
  
  
  if (RequestFields.ContentLengthStr[0] != 0) { //Do we have attached data?
    unsigned int NumRecv;
    
    RequestFields.ContentLength = atol(RequestFields.ContentLengthStr);
    if (RequestFields.ContentLength > 0) {
      //			ThreadDebugMessage(RequestInfo.ThreadNum, "Getting content");
      
      //Allocate memory
      RequestFields.Content = new BYTE[RequestFields.ContentLength];
      
      //Get rest of data from get lines
      NumRecv = DataInBuffer - ReadBufferIndex;
      
      if (NumRecv >RequestFields.ContentLength) {
	//Overflow, only read what they said they'd send
	NumRecv = RequestFields.ContentLength;
      }
      memcpy(RequestFields.Content, RequestInfo.IOBuffer + ReadBufferIndex,
	     NumRecv);
      
      while (NumRecv < RequestFields.ContentLength) {
	NumRecv = GetData(RequestInfo.ClientSocket,
			  RequestFields.Content + NumRecv,
			  RequestFields.ContentLength - NumRecv,
			  RequestInfo.ThreadNum);
	if (NumRecv < 0) return GH_ERROR;
      }
    }
    else {
      RequestFields.Content = NULL;
      RequestFields.ContentLength = 0;
    }
  }
  else {
    RequestFields.Content = NULL;
    RequestFields.ContentLength = 0;
  }
  
  return GH_10_REQUEST;
}

/******************************************************************************/
void CleanUpHTTPHeaders(RequestInfoT &RequestInfo, RequestFieldsT &RequestFields) {
  //Clean up memory allocated for the Content
  if (RequestFields.Content != NULL)
    delete[] RequestFields.Content;
  while (RequestFields.NumOtherHeaders > 0) {
    RequestFields.NumOtherHeaders--;
    delete[] RequestFields.OtherHeaders[RequestFields.NumOtherHeaders].Var;
    delete[] RequestFields.OtherHeaders[RequestFields.NumOtherHeaders].Val;
  }
  
  // clean up memory allocated for the IOBuffer
  if (RequestInfo.IOBuffer != NULL) {
    delete[] RequestInfo.IOBuffer;
    RequestInfo.IOBuffer = NULL;
  }
}