trunk/Search/HttpHandler.cpp

/* ============================================================================
 * Douglas Thrift's Search Engine License
 *
 * Copyright (C) 2002-2004, Douglas Thrift. All Rights Reserved.
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * 3. The end-user documentation included with the redistribution, if any, must
 *    include the following acknowledgment:
 *
 *       "This product includes software developed by Douglas Thrift
 *       (http://computers.douglasthrift.net/searchengine/)."
 *
 *    Alternately, this acknowledgment may appear in the software itself, if
 *    and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Douglas Thrift" and "Douglas Thrift's Search Engine" must not
 *    be used to endorse or promote products derived from this software without
 *    specific prior written permission.  For written permission, please visit
 *    http://www.douglasthrift.net/contact.cgi for contact information.
 *
 * 5. Products derived from this software may not be called "Douglas Thrift's
 *    Search Engine", nor may "Douglas Thrift's Search Engine" appear in their
 *    name, without prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * ============================================================================
 */
// Douglas Thrift's Search Engine HTTP Handler
//
// Douglas Thrift
//
// $Id$

#include "HttpHandler.hpp"

// Lovely C Sockets!
#ifndef _WIN32
// BSD Sockets
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>

inline int closesocket(SOCKET s) { return close(s); }
#endif

#ifndef _OpenSSL_
HttpHandler::HttpHandler() : binary(false), length(0), chunked(false)
#else
HttpHandler::HttpHandler() : binary(false), length(0), chunked(false),
        tls(false)
#endif
{
#ifdef _WIN32
        if (WSAStartup(MAKEWORD(2, 0), &data) != 0)
        {
                error(program + ": WSAStartup");
                exit(1);
        }
#endif // _WIN32
}

HttpHandler::~HttpHandler()
{
#ifdef _WIN32
        WSACleanup();
#endif // _WIN32
}

bool HttpHandler::handle(URL &url, const string referer, bool head)
{
        bool answer(false);

        if ((http = socket(PF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET)
        {
                error(program + ": Socket");
                exit(1);
        }

        sockaddr_in address;
        hostent* host;

        address.sin_family = AF_INET;

        if ((host = gethostbyname(url.getAddress().c_str())) == NULL)
        {
                error(program + ": Host: " + url.getAddress(), true);

                return answer;
        }

        address.sin_addr = *((in_addr*)*host->h_addr_list);
        address.sin_port = htons(url.getPort());

        if (connect(http, (sockaddr*)&address, sizeof(sockaddr_in)) ==
                SOCKET_ERROR)
        {
                error(program + ": Connect");

                return answer;
        }

#ifdef _OpenSSL_
        if (url.getTls())
        {
                tls = true;

                if (!starttls()) return answer;
        }
#endif

        if (head)
        {
                putline("HEAD " + url.getPath() + " HTTP/1.1");
        }
        else
        {
                putline("GET " + url.getPath() + " HTTP/1.1");
        }

        putline("Accept: text/html; text/plain");
#ifndef _OpenSSL_
        putline("User-Agent: " + agent(true) + ' ' + platform());

        if (url.getPort() == 80)
#else
        putline("User-Agent: " + agent(true) + ' ' + platform() + ' '
                + openssl(true));

        if (url.getPort() == 80 && tls || url.getPort() == 443 && tls)
#endif
        {
                putline("Host: " + url.getAddress());
        }
        else
        {
                ostringstream port;

                port << url.getPort();

                putline("Host: " + url.getAddress() + ':' + port.str());
        }

        if (referer != "")
        {
                putline("Referer: " + referer);
        }

        putline("Connection: close");
        putline();

        code response;
        string line;

        do
        {
                line = getline();

                if (line.find("HTTP/") != 0) return answer;

                unsigned dot(line.find('.')), space(line.find(' ')), major, minor;
                istringstream number(line.substr(5, dot - 5) + " " + line.substr(dot
                        + 1, space - dot - 1));

                number >> major;
                number >> minor;

                if (major > 1)
                {
                        cerr << program << ": Potentially Incompatible Server: HTTP/" <<
                                major << "." << minor << "\n";

                        return answer;
                }

                number.clear();
                number.str(line.substr(space + 1, 3));

                number >> response;

                if (response < ok) do line = getline(); while (line != "");
        }
        while (response < ok);

        do
        {
                line = getline();

                if (line != "")
                {
                        unsigned colon(line.find(':'));
                        string field(line.substr(0, colon)), value(line.substr(colon + 1));

                        while (isspace(value[0])) value.erase(0, 1);

                        if (field == "Content-Type")
                        {
                                type = value;
                        }
                        else if (field == "Content-Length")
                        {
                                istringstream number(value);

                                number >> length;
                        }
                        else if (field == "Location")
                        {
                                location = value;
                        }
                        else if (field == "Transfer-Encoding")
                        {
                                chunked = value == "chunked";
                        }
                }
        }
        while (line != "");

        switch (response)
        {
        case ok:
                if (debug) cerr << "response = " << response << "\n";

                answer = true;
                break;
        case choices:
        case moved:
        case found:
                if (debug) cerr << "response = " << response << "\n"
                        << "location = " << location << "\n";

                location = getLink(location, url);
                break;
        case notfound:
        case internal:
                if (debug) cerr << "response = " << response << "\n";
                break;
        default:
                if (debug) cerr << "response = " << response << "\n";

                if (response <= 299) answer = true; else if (response <= 399)
                {
                        location = getLink(location, url);
                }
                break;
        }

        if (!head && answer) populate();

        return answer;
}

void HttpHandler::clear()
{
#ifdef _OpenSSL_
        if (tls)
        {
                SSL_shutdown(ssl);
                SSL_free(ssl);
                SSL_CTX_free(ctx);
        }
#endif

        closesocket(http);

        type = "";
        length = 0;
        location = "";

        page.clear();
        page.str("");

        chunked = false;
#ifdef _OpenSSL_
        tls = false;
#endif
}

void HttpHandler::populate()
{
        if (!chunked)
        {
                unsigned left(length);

                while (left > 0)
                {
                        memset(buffer, 0, BUFSIZ + 1);

                        unsigned bytes(left > BUFSIZ ? BUFSIZ : left);
                        long received;

                        while (true)
                        {
#ifndef _OpenSSL_
                                if ((received = recv(http, buffer, bytes, 0)) == SOCKET_ERROR)
                                {
                                        error(program + ": Recv");
                                        exit(1);
                                }
#else
                                if ((received = !tls ? recv(http, buffer, bytes, 0) :
                                        SSL_read(ssl, buffer, bytes)) <= 0)
                                {
                                        !tls ? error(program + ": Recv") : error(program +
                                                ": SSL Read", int(received));
                                }
#endif
                                else if (received != bytes)
                                {
                                        left -= received;

                                        page << buffer;

                                        memset(buffer, 0, BUFSIZ + 1);

                                        bytes -= received;
                                }
                                else break;
                        }

                        page << buffer;

                        left -= bytes;
                }
        }
        else
        {
                unsigned chunk;

                do
                {
                        istringstream number(getline());

                        number.setf(ios_base::hex, ios_base::basefield);

                        number >> chunk;

                        unsigned left(chunk);

                        while (left > 0)
                        {
                                memset(buffer, 0, BUFSIZ + 1);

                                unsigned bytes(left > BUFSIZ ? BUFSIZ : left);
                                long received;

                                while (true)
                                {
#ifndef _OpenSSL_
                                        if ((received = recv(http, buffer, bytes, 0)) ==
                                                SOCKET_ERROR)
                                        {
                                                error(program + ": Recv");
                                                exit(1);
                                        }
#else
                                        if ((received = !tls ? recv(http, buffer, bytes, 0) :
                                                SSL_read(ssl, buffer, bytes)) <= 0)
                                        {
                                                !tls ? error(program + ": Recv") : error(program +
                                                        ": SSL Read", int(received));

                                                exit(1);
                                        }
#endif
                                        else if (received != bytes)
                                        {
                                                left -= received;
                                                page << buffer;

                                                memset(buffer, 0, BUFSIZ + 1);

                                                bytes -= received;
                                        }
                                        else break;
                                }

                                page << buffer;

                                left -= bytes;
                        }

                        getline();

                        length += chunk;
                }
                while (chunk > 0);
        }

        if (!binary)
        {
                string page(this->page.str());

                for (unsigned index(0); index < page.length(); index++)
                {
                        if (page[index] == '\r' && (index + 1 < page.length()) ?
                                page[index + 1] == '\n' : false)
                        {
                                page.erase(index, 1);
                        }
                        else if (page[index] == '\r')
                        {
                                page[index] = '\n';
                        }
                }

                this->page.str(page);
        }
}

void HttpHandler::putline(const string line)
{
        sprintf(buffer, "%s\r\n", line.c_str());

#ifndef _OpenSSL_
        if (send(http, buffer, strlen(buffer), 0) == SOCKET_ERROR)
        {
                error(program + ": Send");
                exit(1);
        }
#else
        if (!tls)
        {
                if (send(http, buffer, strlen(buffer), 0) == SOCKET_ERROR)
                {
                        error(program + ": Send");
                        exit(1);
                }
        }
        else
        {
                int number;

                if ((number = SSL_write(ssl, buffer, strlen(buffer))) <= 0)
                {
                        error(program + ": SSL Write", number);
                        exit(1);
                }
        }
#endif
}

string HttpHandler::getline()
{
        string line;
        char byte;

        do
        {
#ifndef _OpenSSL_
                if (recv(http, &byte, 1, 0) == SOCKET_ERROR)
                {
                        error(program + ": Recv");
                }
#else
                if (!tls)
                {
                        if (recv(http, &byte, 1, 0) == SOCKET_ERROR)
                        {
                                error(program + ": Recv");
                        }
                }
                else
                {
                        int number;

                        if ((number = SSL_read(ssl, &byte, 1)) <= 0)
                        {
                                error(program + ": SSL Read", number);
                        }
                }
#endif

                if (byte != '\r' && byte != '\n')
                {
                        line += byte;
                }
        }
        while (byte != '\n');

        return line;
}

void HttpHandler::error(const string& prefix, bool host)
{
#ifdef _WIN32
        string error;

        switch (WSAGetLastError())
        {
        case WSAEACCES:
                error = "Permission denied";
                break;
        case WSAEADDRINUSE:
                error = "Address already in use";
                break;
        case WSAEADDRNOTAVAIL:
                error = "Cannot assign requested address";
                break;
        case WSAEAFNOSUPPORT:
                error = "Address family not supported by protocol family";
                break;
        case WSAEALREADY:
                error = "Operation already in progress";
                break;
        case WSAECONNABORTED:
                error = "Software caused connection abort";
                break;
        case WSAECONNREFUSED:
                error = "Connection refused";
                break;
        case WSAECONNRESET:
                error = "Connection reset by peer";
                break;
        case WSAEDESTADDRREQ:
                error = "Destination address required";
                break;
        case WSAEFAULT:
                error = "Bad address";
                break;
        case WSAEHOSTDOWN:
                error = "Host is down";
                break;
        case WSAEHOSTUNREACH:
                error = "No route to host";
                break;
        case WSAEINPROGRESS:
                error = "Operation now in progress";
                break;
        case WSAEINTR:
                error = "Interrupted function call";
                break;
        case WSAEINVAL:
                error = "Invalid argument";
                break;
        case WSAEISCONN:
                error = "Socket is already connected";
                break;
        case WSAEMFILE:
                error = "Too many open files";
                break;
        case WSAEMSGSIZE:
                error = "Message too long";
                break;
        case WSAENETDOWN:
                error = "Network is down";
                break;
        case WSAENETRESET:
                error = "Network dropped connection on reset";
                break;
        case WSAENETUNREACH:
                error = "Network is unreachable";
                break;
        case WSAENOBUFS:
                error = "No buffer space available";
                break;
        case WSAENOPROTOOPT:
                error = "Bad protocol option";
                break;
        case WSAENOTCONN:
                error = "Socket is not connected";
                break;
        case WSAENOTSOCK:
                error = "Socket operation on non-socket";
                break;
        case WSAEOPNOTSUPP:
                error = "Operation not supported";
                break;
        case WSAEPFNOSUPPORT:
                error = "Protocol family not supported";
                break;
        case WSAEPROCLIM:
                error = "Too many processes";
                break;
        case WSAEPROTONOSUPPORT:
                error = "Protocol not supported";
                break;
        case WSAEPROTOTYPE:
                error = "Protocol wrong type for socket";
                break;
        case WSAESHUTDOWN:
                error = "Cannot send after socket shutdown";
                break;
        case WSAESOCKTNOSUPPORT:
                error = "Socket type not supported";
                break;
        case WSAETIMEDOUT:
                error = "Connection timed out";
                break;
        case WSATYPE_NOT_FOUND:
                error = "Class type not found";
                break;
        case WSAEWOULDBLOCK:
                error = "Resource temporarily unavailable";
                break;
        case WSAHOST_NOT_FOUND:
                error = "Host not found";
                break;
        case WSA_INVALID_HANDLE:
                error = "Specified event object handle is invalid";
                break;
        case WSA_INVALID_PARAMETER:
                error = "One or more parameters are invalid";
                break;
//      case WSAINVALIDPROCTABLE:
//              error = "Invalid procedure table from service provider";
//              break;
//      case WSAINVALIDPROVIDER:
//              error = "Invalid service provider version number";
//              break;
        case WSA_IO_INCOMPLETE:
                error = "Overlapped I/O event object not in signaled state";
                break;
        case WSA_IO_PENDING:
                error = "Overlapped operations will complete later";
                break;
        case WSA_NOT_ENOUGH_MEMORY:
                error = "Insufficient memory available";
                break;
        case WSANOTINITIALISED:
                error = "Successful WSAStartup not yet performed";
                break;
        case WSANO_DATA:
                error = "Valid name, no data record of requested type";
                break;
        case WSANO_RECOVERY:
                error = "This is a non-recoverable error";
                break;
//      case WSAPROVIDERFAILEDINIT:
//              error = "Unable to initialize a service provider";
//              break;
        case WSASYSCALLFAILURE:
                error = "System call failure";
                break;
        case WSASYSNOTREADY:
                error = "Network subsystem is unavailable";
                break;
        case WSATRY_AGAIN:
                error = "Non-authoritative host not found";
                break;
        case WSAVERNOTSUPPORTED:
                error = "WINSOCK.DLL version out of range";
                break;
        case WSAEDISCON:
                error = "Graceful shutdown in progress";
                break;
        case WSA_OPERATION_ABORTED:
                error = "Overlapped operation aborted";
                break;
        default:
                error = "Unknown error";
                break;
        }

        cerr << prefix << ": " << error << "\n";
#else
        if (host)
        {
                string error;

                switch (h_errno)
                {
                case HOST_NOT_FOUND:
                        error = "Unknown host";
                        break;
                case TRY_AGAIN:
                        error = "Host name lookup failure";
                        break;
                case NO_RECOVERY:
                        error = "Unknown server error";
                        break;
                case NO_DATA:
                        error = "No address associated with name";
                        break;
                default:
                        error = "Unknown error";
                        break;
                }

                cerr << prefix << ": " << error << "\n";
        }
        else
        {
                perror(prefix.c_str());
        }
#endif // _WIN32
}

#ifdef _OpenSSL_
void HttpHandler::error(const string& prefix, int number)
{
        string error;

        switch (SSL_get_error(ssl, number))
        {
        case SSL_ERROR_NONE:
                error = "The TLS/SSL I/O operation completed";
                break;
        case SSL_ERROR_ZERO_RETURN:
                error = "The TLS/SSL connection has been closed";
                break;
        case SSL_ERROR_WANT_READ:
        case SSL_ERROR_WANT_WRITE:
        case SSL_ERROR_WANT_CONNECT:
//      case SSL_ERROR_WANT_ACCEPT:
        case SSL_ERROR_WANT_X509_LOOKUP:
                error = "The operation did not complete";
                break;
        case SSL_ERROR_SYSCALL:
                if (int err = ERR_get_error() != 0)
                {
                        error = ERR_reason_error_string(err);
                }
                else
                {
                        switch (number)
                        {
                        case 0:
                                error = "An EOF was observed that violates the protocol";
                                break;
                        case -1:
                                this->error(prefix);
                                return;
                        default:
                                error = "Unknown error";
                                break;
                        }
                }
                break;
        case SSL_ERROR_SSL:
                error = ERR_reason_error_string(ERR_get_error());
                break;
        default:
                error = "Unknown error";
                break;
        }

        cerr << prefix << ": " << error << "\n";
}

bool HttpHandler::starttls()
{
        SSL_load_error_strings();
        SSL_library_init();

#ifndef _urandomdev_
        int pid(getpid()), now(time(NULL));
        unsigned seed(now > pid ? now - pid : pid - now);
        char* junk = new char[seed % 30 + 2];

        junk[0] = pid;
        junk[seed % 30 + 1] = now;

        srand(seed);

        for (size_t index = 1; index < seed % 30 + 1; index++)
        {
                junk[index] = rand();
        }

        if (debug)
        {
                cerr << "junk = {\n";

                for (size_t index = 1; index < seed % 30 + 2; index++)
                {
                        cerr << "   [" << index << "] = " << unsigned(junk[index]) << "\n";
                }

                cerr << "}\n";
        }

        RAND_seed(junk, seed % 30 + 2);

        delete junk;
#else
        if (debug) cerr << "junk = /dev/urandom\n";
#endif

        ctx = SSL_CTX_new(TLSv1_client_method());

        if (ctx == NULL)
        {
                cerr << program << ": SSL CTX New: "
                        << ERR_reason_error_string(ERR_get_error()) << "\n";

                return false;
        }

        ssl = SSL_new(ctx);

        if (SSL_set_fd(ssl, http) == 0)
        {
                cerr << program << ": SSL Set FD: "
                        << ERR_reason_error_string(ERR_get_error()) << "\n";

                return false;
        }

        int number;

        if ((number = SSL_connect(ssl)) <= 0)
        {
                error(program + ": SSL Connect", number);

                return false;
        }

        return true;
}
#endif
Revision:	350
Committed:	2004-05-27T20:29:11-07:00 (21 years ago) by Douglas Thrift
File size:	16720 byte(s)
Log Message:	C++ify again!