Beesnest/DcConnectionThread.cpp

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/*
Copyright 2007 Erez Bibi (erezbibi@users.sourceforge.net)
This file is part of Beesnest.

Beesnest 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.

Beesnest 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 Beesnest; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

/**
 * DcConnectionThread.cpp: Implementation of CdcConnectionThread class.
 * for documentation see the header file.
 */

#include "DcConnectionThread.h"

#define SSI_ERR(inst) " --- Cannot Execute: " + inst + " --- "


int volatile CdcConnectionThread::nThreadCounter = 0;


CdcConnectionThread::CdcConnectionThread (CdcSocket* psoc) throw (CdcException)
: oRequest (psoc), oResponse (psoc, oBuffList), pUserStatus (NULL)
{
    if (psoc == NULL)
        throw (CdcException ("Socket pointer is null"));
    pSocket = psoc;

    sLog.reserve (1000);
    nThreadNumber = ++nThreadCounter;
    oThread.MakeThread (DcRun, (void*)this);
    oThread.SetPriority (DC_TP_NORNAL);
}


CdcConnectionThread::~CdcConnectionThread ()
{
    /* Write the data into the log file before deleting the object. */
    if (sLog.IsEmpty () == false)
        PrintString (sLog, PS_LOG);
    if (pSocket != NULL)
        delete pSocket;
}

bool CdcConnectionThread::ReadRequest ()
{
    try
    {   /* Read and parse the request. */
        oRequest.ReadNextRequest ();
    }
    catch (CdcExceptionParse& e)
    {   /* Bad request. */
        if (e.GetExpCode () == DC_NOT_SUPPORT)
            oResponse.SetStatus (501);
        else
            oResponse.SetStatus (400);
        sLastError = e.ToStr ();
        oBuffList.Clear ();     /* Clear old list. */
        /* Add new buffer with the new text. */
        oBuffList.Add (CdcBuffer (sLastError.GetLength ()).Append (sLastError));
        return false;
    }
    return true;
}


bool CdcConnectionThread::CheckAccept (CdcString type)
{
    CdcString accept = oRequest.GetHeaderField ("Accept");
    if (accept.IsEmpty ()) return true;
    if (accept.Find (type) != -1 ) return true;
    type = type.Left (type.Find ('/')) + "/*";
    if (accept.Find (type) != -1) return true;
    type = "*/*";
    if (accept.Find (type) != -1) return true;

    return false;
}

bool CdcConnectionThread::DoIfModified (const CdcRetrieveFile& file)
{
    if (oRequest.GetVersion () == PROTOCOL10_VRS)
        return true;

    CdcString ifs (oRequest.GetHeaderField ("If-Modified-Since"));
    if (ifs.IsEmpty ()) return true;

    /* No "If-Modified-Since" for HTML pages (includes, scripts). */
    if (CdcParameters::GetParam ("Server->File-Types->" +
            file.GetFileAttrib ().GetFileExtention () +
                "->Client-Type") == "text/html")
        return true;

    /* If file modified since... */
    try
    {
        CdcHttpTime mod (ifs);
        if (mod < CdcHttpTime::GetCurrentTimeGMT() &&
            mod > file.GetFileAttrib ().GetLastModified ())
        {
            oResponse.SetStatus (304);
            return false;
        }
        else
            return true;
    }
    /* Ignore if error... */
    catch (CdcException& e) { PrintString (e.ToStr (), PS_DBG); }
    return true;
}


// There is some code copy here...
bool CdcConnectionThread::DoIfUnmodified (const CdcRetrieveFile& file)
{
    if (oRequest.GetVersion () == PROTOCOL10_VRS)
        return true;

    CdcString ifs (oRequest.GetHeaderField ("If-Unmodified-Since"));
    if (ifs.IsEmpty ()) return true;

    /* No "If-Unmodified-Since" for HTML pages. */
    if (CdcParameters::GetParam ("Server->File-Types->" +
            file.GetFileAttrib ().GetFileExtention () +
                "->Client-Type") == "text/html")
        return true;

    /* If file modified since... */
    try
    {
        CdcHttpTime mod (ifs);
        if (mod < CdcHttpTime::GetCurrentTime() &&
            mod < file.GetFileAttrib ().GetLastModified ())
        {
            oResponse.SetStatus (412);
            return false;
        }
        else
            return true;
    }
    /* Ignore if error... */
    catch (CdcException& e) { PrintString (e.ToStr (), PS_DBG); }
    return true;
}


bool CdcConnectionThread::BuildNormalResponse (CdcRetrieveFile& file)
{
    /* First do some general stuff. */
    oResponse.SetStatus (200);
    oResponse.SetHeaderField ("Content-Type",
        file.GetFileAttrib ().GetClientFileType ());
    oResponse.SetHeaderField ("Last-Modified",
        file.GetFileAttrib ().GetLastModified ().FormatGmt (TIME_FORMAT));
    if (oRequest.GetMethod () == "HEAD")
        return true;
    /* Get limits. */
    nResSizeLimit = CdcParameters::ToInt (CdcParameters::GetParam
        ("Server->Response-Size-Limit"));
    nResTimeLimit = CdcParameters::ToInt (CdcParameters::GetParam
        ("Server->Response-Time-Limit"));
    /* Get the file data. */
    CdcBuffersList buff_list;
    bool check_allow = true;
    /* isExecScript Can be changed by CheckAllow (from BuildBuffersList). */
    isExecScript = file.GetFileAttrib ().IsExecScript ();
    oIncSet.clear ();   /* for SSI include loop preventer. */
    BuildBuffersList (file, buff_list, check_allow);
    /* Execute scripts. This function fills the Response buffers list. */
    if (isExecScript)
        ExecuteScript (buff_list);
    else
        oBuffList = buff_list;  /* Just copy buffers list. */
    /* Check if need to log out the user. */
    if (CdcLoginManager::CheckLogout (oRequest, oResponse))
        /* Do not cache logout page. */
        oResponse.SetHeaderField ("Cache-Control", "no-cache");
    pUserStatus = NULL; /* So we won't use this set for other pages. */
    return true;
}


bool CdcConnectionThread::BuildBuffersList (const CdcRetrieveFile& file,
                                            CdcBuffersList& list,
                                            bool& check_allow)
{
    /* Skip file if it already in the set. */
    if (oIncSet.find (file.GetFileAttrib ().GetURL ()) != oIncSet.end ())
        return true;
    oIncSet.insert (file.GetFileAttrib ().GetURL ());
    /* Check if page require login access. */
    if (check_allow)
    {
        int ret = CheckAllow (file.GetFileAttrib ().GetURL (), list);
        if (ret == DC_LM_SEND)
            return false;           /* Login or Deny page. */
        if (ret == DC_LM_OK)
            check_allow = false;    /* Don't need to check access any more. */
    }
    /* Get the buffer. */
    CdcBuffer& buff = file.GetData ();
    int new_place, place = 0;
    /* Go over all includes in buffer if file type is text/html. */
    if (file.GetFileAttrib ().GetClientFileType () == "text/html")
    {   while ((new_place = buff.Find ("<!--#", place)) > -1)
        {   /* Add section to list. */
            if (new_place > place && buff.IsWhiteSpaces (place, new_place) == false)
                list.Add (buff, file.GetFileAttrib(), place, new_place - place);
            place = new_place + 5;          /* 5 is length of "<!--#". */
            int temp = buff.Find ("-->", place);
            if (temp == -1) continue;
            CdcString inner (buff.GetPointer () + place, temp - place);
            bool isInclude = false;
            CdcString inc = ExecuteSSI (inner, file, isInclude);
            if (isInclude)
            {   /* This is an include file. */
                CdcRetrieveFile inc_file (inc, oRequest.GetHost (), true);
                if (inc_file.GetFileAttrib ().IsFileFound ())
                    /* The recursive call. */
                    if (BuildBuffersList (inc_file, list, check_allow) == false)
                        return false;
            }
            else if (inc.IsEmpty () == false)
            {   /* Just add the returned string as a buffer to the list. */
                CdcBuffer tmp_buf (inc.GetLength ());
                tmp_buf.Append (inc);
                list.Add (tmp_buf, 0, -1);
            }
            place = temp + 3;   /* 3 is length of "-->". */
        }
    }
    /* And add rest of buffer to list. */
    if (place < buff.GetDataSize () && buff.IsWhiteSpaces (place) == false)
        list.Add (buff, file.GetFileAttrib(), place, buff.GetDataSize () - place);
    oIncSet.erase (file.GetFileAttrib ().GetURL ());    /* Pop from include stack. */
    return true;
}

// Small help function for the SSI instructions.
// Strip space, '=' and quotes from a string.
CdcString ClenSsiItem (const CdcString& str)
{
    int start = 0, end = str.GetLength () - 1;
    char chr, qt = 0;
    while (start < str.GetLength ())
    {
        chr = str[start];
        if (! (isspace (chr) || chr == '=' || chr == '"' || chr == '\'')) break;
        ++start;
        if (chr == '"' || chr == '\'') break;
    }
    if (start == str.GetLength ()) return EMPTY_STR;
    if (chr == '"' || chr == '\'') qt = chr;
    while (end > 0)
    {
        chr = str[end];
        if (! (isspace (chr) || chr == qt)) break;
        --end;
        if (chr == qt) break;
    }
    if (end == 0) return EMPTY_STR;
    if (qt && chr != qt) --start;
    return str.Mid (start, end - start + 1);
}

//<!--#set var="name" value="Rich" -->
//<!--#echo var="DATE_LOCAL" -->
//<!--#include file="..." -->
//<!--#include virtual="..." -->
CdcString CdcConnectionThread::ExecuteSSI (const CdcString& str,
                                           const CdcRetrieveFile& file,
                                           bool& isInclude)
{
    /* Get instruction. */
    CdcString inner = str.Trim ();
    int place;
    if ((place = inner.FindOneOf (" \t")) == -1) return SSI_ERR (str);
    CdcString inst = inner.Left (place);
    inner = inner.Mid (place).Trim ();

    if (inst == "include")
    {   /* Return the URL of the file. */
        CdcString tmp = ExtractURL (inner, file);
        if (tmp.IsEmpty ()) return SSI_ERR (str);
        isInclude = true;
        return tmp;
    }
    if (inst == "echo")
    {   /* Return the value of a request variable. */
        if ((place = inner.Find ("var")) == -1) return SSI_ERR (str);
        CdcString tmp = oRequest.GetVariable (ClenSsiItem (inner.Mid (place + 3)));
        if (tmp.Find (SCRIPT_STR) > -1)     /* Security check */
            return SSI_ERR (CdcString ("Might have script in variable"));
        return tmp;
    }
    if (inst == "set")
    {   /* Set a variable. */
        if ((place = inner.Find ("value")) == -1) return SSI_ERR (str);
        CdcString val = ClenSsiItem (inner.Mid (place + 5));
        inner = inner.Left (place);
        if ((place = inner.Find ("var")) == -1) return SSI_ERR (str);
        CdcString name = ClenSsiItem (inner.Mid (place + 3));
        if (name == "BNI_TimeLimit")
            /* Well, I have "ToInt" it in CdcParameters... */
            nResTimeLimit = CdcParameters::ToInt (val);
        else if (name == "BNI_SizeLimit")
            nResSizeLimit = CdcParameters::ToInt (val);
        else
            oRequest.SetVariable (name, val);
        return EMPTY_STR;
    }
    return SSI_ERR (str);
}

CdcString CdcConnectionThread::ExtractURL (const CdcString& inner,
                                           const CdcRetrieveFile& file)
{
    /* Get the URL part. */
    int place;
    if ((place = inner.Find ("file")) > -1)
    {
        CdcString url = ClenSsiItem (inner.Mid (place + 4));
        CdcString base = "/" + file.GetFileAttrib ().GetURL ();
        bool cont;
        do
        {
            base = base.Left (base.ReverseFind ('/'));
            cont = (url.Left (3) == "../");
            if (cont)
                url = url.Mid (3);
        } while (cont);
        return base + url;
    }
    else if ((place = inner.Find ("virtual")) > -1)
        return ClenSsiItem (inner.Mid (place + 7));
    return EMPTY_STR;
}

int CdcConnectionThread::CheckAllow (const CdcString& url, CdcBuffersList& list)
{
    CdcString url_temp = url;
    url_temp.MakeLower ();
    CdcString param_path ("Login-Manager->Access->" + oRequest.GetHost ()
        + "->." + url_temp);
    CdcString group;
    int place;
    do
    {   /* Find if this page is protected. */
        if (!(group = CdcParameters::GetParam (param_path)).IsEmpty ())
            break;
        place = param_path.ReverseFind ('/');
        if (place == -1) break;
        param_path = param_path.Left (place);
    } while (true);
    if (group.IsEmpty ()) return DC_LM_NONE;
    //if (group == "all") return DC_LM_OK; ???
    /* Call login manager. */
    int code;
    CdcString new_page;
    pUserStatus = CdcLoginManager::CheckAccess
        (group, oRequest, oResponse, code, new_page);
    if (code == DC_LM_SEND)
    {   /* Send other page. */
        list.Clear ();
        if (new_page.IsEmpty () == false) /* if new_page is empty this is 401 response.) */
        {
            CdcRetrieveFile file (new_page, oRequest.GetHost ());
            /* Set the new page. If login page is missing, BuildBuffersList will
                throw exeption and the connection will be closed. */
            oResponse.SetHeaderField ("Content-Type",
                file.GetFileAttrib ().GetClientFileType ());
            oResponse.SetHeaderField ("Last-Modified",
                file.GetFileAttrib ().GetLastModified ().FormatGmt (TIME_FORMAT));
            isExecScript = file.GetFileAttrib ().IsExecScript ();
            bool ca = false;
            BuildBuffersList (file, list, ca);
        }
    }
    /* Browser should not cache protected pages. */
    oResponse.SetHeaderField ("Cache-Control", "no-cache");
    return code;
}

// === Execute Script Functions === //

void CdcConnectionThread::ExecuteScript (CdcBuffersList& bufflist)
{
    int offset, len;
    oBuffList.Clear ();     /* The response buff list is getting all data here. */
    /* Create an Engines Bank (pUserStatus may be NULL)*/
    int start_time = time (NULL);
    CdcEnginesBank eb (&oRequest, &oResponse, pUserStatus);
    bool ret = bufflist.SeekFirst ();
    while (ret)
    {   /* Go over all (part of) buffers in the original list. */
        const CdcBuffer* pbuff = bufflist.GetBufferPointer ();
        offset = bufflist.GetBufferOffset ();
        len = bufflist.GetLength ();
        if (bufflist.GetFileAttrib ().IsExecScript ())
        {   /* Need to Execute on this buffer */
            CdcString eng = bufflist.GetFileAttrib ().GetScriptEngine ();
            if (eng.IsEmpty () == false)
            {   /* this file type has associate engine. */
                if (ExecuteSection (eb, eng, pbuff, start_time, offset, len)
                    == false) break;
            }
            else
            {   /* This buffer has <bnscript> tag in it */
                if (ExecuteBufferSections (eb, pbuff, start_time, offset, len)
                    == false) break;
            }
        }
        else    /* No need to execute script on this buffer part. */
            oBuffList.Add (*pbuff, offset, len);
        if (nResSizeLimit > 0 && oBuffList.GetDataSize () >= nResSizeLimit)
            break;  /* Got to size limit. */
        ret = bufflist.SeekNext ();     /* Go to next buffer. */
    }
}


bool CdcConnectionThread::ExecuteBufferSections (CdcEnginesBank& eb,
    const CdcBuffer* pbuff, int start_time, int offset, int len)
{
    int place, end_place, tmp_place, tmp2_place;
    if (pbuff == NULL) return false;
    while ((place = pbuff->Find (SCRIPT_STR, offset, offset + len)) > -1)
    {   /* Find the ">" sign. */
        tmp_place = place + SCRIPT_STR_LEN;
        if ((end_place = pbuff->Find (SCRIPT_TRM, tmp_place, offset + len)) == -1)
            return false;
        /* Try to find script engine name. */
        CdcString eng_name;
        if (tmp_place != end_place)     /* So it is not just <bnscript>. */
        {   /* Found script engine name. */
            eng_name = CdcString (pbuff->GetPointer () + tmp_place,
                end_place - tmp_place);
            tmp_place = end_place + 1;  /* This is the real end of <bnscript> tag. */
            eng_name.Trim ();
        }
        /* Find the "</bnscript>" sign. */
        if ((end_place = pbuff->Find (SCRIPT_END, tmp_place, offset + len)) == -1)
            return false;
        if ((tmp2_place = pbuff->Find (SCRIPT_TRM, end_place, offset + len)) == -1)
            return false;
        /* First insert the part before this script. */
        oBuffList.Add (*pbuff, offset, place - offset);
        place = tmp_place;
        tmp_place = end_place + SCRIPT_END_LEN;
        /* Try to find "delete" command in the </bnscript> tag */
        bool eng_del = tmp_place != tmp2_place &&   /* Complicate one. */
            (CdcString (pbuff->GetPointer () + tmp_place,
            tmp2_place - tmp_place)).Trim () == DEL_CMD;
        bool isok = ExecuteSection (eb, eng_name, pbuff, start_time,
                place, end_place - place);
        if (eng_del || isok == false)   /* If need to - delete the engine. */
            eb.DeleteEngine (eng_name);
        if (isok == false) return false;
        end_place = tmp2_place + 1;
        len -= (end_place - offset);    /* Set rest of buff length. */
        offset = end_place;     /* Set new offset. */
    }   /* End of buffer loop. */
    /* Now add the rest of the buffer. */
    oBuffList.Add (*pbuff, offset, len);
    return true;
}


bool CdcConnectionThread::ExecuteSection (CdcEnginesBank& eb,
    const CdcString eng_name, const CdcBuffer* pbuff, int start_time,
    int offset, int len)
{
    bool isok = false;
    /* Try to get the engine. */
    IdcEngine* peng = eb.GetEngine (eng_name);
    if (peng == NULL || pbuff == NULL)  return false;
    /* make a new BufferHolder of the script part and process it. */
    BufferHolder code (pbuff->GetPointer () + offset, len);
    BufferHolder result;
    if ((nResSizeLimit == 0 || oBuffList.GetDataSize () < nResSizeLimit) &&
        (nResTimeLimit == 0 || time (NULL) - start_time < nResTimeLimit))
        isok = peng->Process (code, result, nResSizeLimit - oBuffList.GetDataSize ());
    if (result.empty () == false)
    {   /* Add the result HTML to the list, as a new buffer. */
        CdcBuffer new_buff (result.size);
        new_buff.Append (result.pointer, result.size);
        oBuffList.Add (new_buff);
    }
    if (isok == false || /* engine error - return with what you have. */
        nResSizeLimit > 0 && oBuffList.GetDataSize () >= nResSizeLimit ||
        nResTimeLimit > 0 && time (NULL) - start_time >= nResTimeLimit)
        return false;
    return true;
}

void CdcConnectionThread::FillInLog ()
{
    /* Get the log format string. */
    CdcString temp_log = CdcParameters::GetParam ("Server->Log-File->Format");
    temp_log.reserve (500);
    /* Fill in the log string. */
    temp_log.Replace ("THREADNO", CdcString::IntToString (nThreadNumber));
    temp_log.Replace ("TIME", CdcHttpTime::GetCurrentTime ().Format ("%c"));
    temp_log.Replace ("IP", pSocket->GetClientAddress ());
    temp_log.Replace ("CLIENT", oRequest.GetHeaderField ("user-agent"));
    temp_log.Replace ("METHOD", oRequest.GetMethod ());
    temp_log.Replace ("URL", oRequest.GetURL ());
    temp_log.Replace ("FULL", oRequest.GetFullURL ());
    temp_log.Replace ("HOST", oRequest.GetHost ());
    temp_log.Replace ("STATUS", oResponse.GetStatus ());
    temp_log.Replace ("ERROR", sLastError);
    temp_log.Replace ("BR", "\n");
    temp_log.Replace ("TAB", "\t");
    /* Add the new log string to the end of the log string. */
    sLog += temp_log;
}


int DcRun (void* pParam)
{
    CdcConnectionThread* pThis = (CdcConnectionThread*)pParam;
    if (pThis == NULL) return 1;   /* if pParam is not valid. */

    PrintString (CdcString::IntToString (pThis->nThreadNumber) +
        " - Connection opened", PS_TRD);

    bool keep_alive;
    try
    {
        do
        {   /* Read request. */
            if ((keep_alive = pThis->ReadRequest ()) == true)
            {   /* Get the file. */
                CdcRetrieveFile file (pThis->oRequest.GetURL (),
                                      pThis->oRequest.GetHost ());
                /* Redirect */
                if (file.GetFileAttrib ().IsRedirect () == true)
                {
                    pThis->oResponse.SetStatus (301);
                    pThis->oResponse.SetHeaderField ("Location",
                        file.GetFileAttrib ().GetURL ());
                }
                /* File not found. */
                else if (file.GetFileAttrib ().IsFileFound () == false)
                    pThis->oResponse.SetStatus (404);
                /* Check the Accept request header field. */
                else if (pThis->CheckAccept (
                    file.GetFileAttrib ().GetClientFileType ()) == false)
                    pThis->oResponse.SetStatus (406);
                /* Check the 'if modified' field, and build a normal response. */
                else if (pThis->DoIfModified (file) &&
                         pThis->DoIfUnmodified (file))
                    pThis->BuildNormalResponse (file);
                /* Check the 'keep alive' ('Connection') filed. */
                keep_alive = pThis->oRequest.GetHeaderField ("Connection") !=
                    "close" && pThis->oResponse.GetHeaderField ("Connection") != "close";
            }
            if (keep_alive == false)
                pThis->oResponse.SetHeaderField ("Connection", "close");
            /* Send the response. */
            pThis->oResponse.SendResponse ();
            pThis->FillInLog ();
            if (keep_alive) pThis->oResponse.Restart ();
        }   /* Close connection if 'Connection' = 'close'. */
        while (keep_alive);
        PrintString (CdcString::IntToString (pThis->nThreadNumber) +
        " - Connection closed", PS_TRD);
    }
    catch (CdcException& e)
    {
        PrintString (CdcString::IntToString (pThis->nThreadNumber) + " - "
            + e.ToStr (), PS_TRD);
    }
    catch (int e)
    {   /* Exception from a script engine. */
        PrintString (CdcString::IntToString (pThis->nThreadNumber) + " - " +
            "Exception from a script engine: " + CdcString::IntToString (e), PS_TRD);
    }
    catch (BufferHolder e)
    {   /* Uncatched exception from an adapter - should not happen. */
        /* The BufferHolder might point to an invalid string - we won't touch it. */
        PrintString ("Unhandled exception from an adapter");
    }
    CdcLoadController::ThreadDone (pThis->pSocket);
    delete pThis;
    return 0;
}