
/*
 * $Id$
 *
 * DEBUG: section 10    Gopher
 * AUTHOR: Harvest Derived
 *
 * SQUID Web Proxy Cache          http://www.squid-cache.org/
 * ----------------------------------------------------------
 *
 *  Squid is the result of efforts by numerous individuals from
 *  the Internet community; see the CONTRIBUTORS file for full
 *  details.   Many organizations have provided support for Squid's
 *  development; see the SPONSORS file for full details.  Squid is
 *  Copyrighted (C) 2001 by the Regents of the University of
 *  California; see the COPYRIGHT file for full details.  Squid
 *  incorporates software developed and/or copyrighted by other
 *  sources; see the CREDITS file for full details.
 *
 *  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., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 *
 */

#include "squid.h"
#include "errorpage.h"
#include "Store.h"
#include "HttpRequest.h"
#include "HttpReply.h"
#include "comm.h"
#if DELAY_POOLS
#include "DelayPools.h"
#include "MemObject.h"
#endif
#include "MemBuf.h"
#include "forward.h"
#include "rfc1738.h"
#include "SquidTime.h"

/**
 \defgroup ServerProtocolGopherInternal Server-Side Gopher Internals
 \ingroup ServerProtocolGopherAPI
 * Gopher is somewhat complex and gross because it must convert from
 * the Gopher protocol to HTTP.
 */

/* gopher type code from rfc. Anawat. */
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_FILE         '0'
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_DIRECTORY    '1'
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_CSO          '2'
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_ERROR        '3'
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_MACBINHEX    '4'
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_DOSBIN       '5'
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_UUENCODED    '6'
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_INDEX        '7'
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_TELNET       '8'
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_BIN          '9'
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_REDUNT       '+'
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_3270         'T'
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_GIF          'g'
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_IMAGE        'I'

/// \ingroup ServerProtocolGopherInternal
#define GOPHER_HTML         'h'	/* HTML */
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_INFO         'i'
/**
  \ingroup ServerProtocolGopherInternal
  W3 address
 */
#define GOPHER_WWW          'w'
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_SOUND        's'

/// \ingroup ServerProtocolGopherInternal
#define GOPHER_PLUS_IMAGE   ':'
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_PLUS_MOVIE   ';'
/// \ingroup ServerProtocolGopherInternal
#define GOPHER_PLUS_SOUND   '<'

/// \ingroup ServerProtocolGopherInternal
#define GOPHER_PORT         70

/// \ingroup ServerProtocolGopherInternal
#define TAB                 '\t'
/// \ingroup ServerProtocolGopherInternal
/// \todo CODE: should this be a protocol-specific thing?
#define TEMP_BUF_SIZE       4096
/// \ingroup ServerProtocolGopherInternal
#define MAX_CSO_RESULT      1024

/// \ingroup ServerProtocolGopherInternal
typedef struct gopher_ds {
    StoreEntry *entry;
    enum {
        NORMAL,
        HTML_DIR,
        HTML_INDEX_RESULT,
        HTML_CSO_RESULT,
        HTML_INDEX_PAGE,
        HTML_CSO_PAGE
    } conversion;
    int HTML_header_added;
    int HTML_pre;
    char type_id;
    char request[MAX_URL];
    int cso_recno;
    int len;
    char *buf;			/* pts to a 4k page */
    int fd;
    HttpRequest *req;
    FwdState::Pointer fwd;
    char replybuf[BUFSIZ];
} GopherStateData;

static PF gopherStateFree;
static void gopherMimeCreate(GopherStateData *);
static void gopher_request_parse(const HttpRequest * req,
                                 char *type_id,
                                 char *request);
static void gopherEndHTML(GopherStateData *);
static void gopherToHTML(GopherStateData *, char *inbuf, int len);
static PF gopherTimeout;
static IOCB gopherReadReply;
static IOCB gopherSendComplete;
static PF gopherSendRequest;

/// \ingroup ServerProtocolGopherInternal
static char def_gopher_bin[] = "www/unknown";

/// \ingroup ServerProtocolGopherInternal
static char def_gopher_text[] = "text/plain";

/// \ingroup ServerProtocolGopherInternal
static void
gopherStateFree(int fdnotused, void *data)
{
    GopherStateData *gopherState = (GopherStateData *)data;

    if (gopherState == NULL)
        return;

    if (gopherState->entry) {
        gopherState->entry->unlock();
    }

    HTTPMSGUNLOCK(gopherState->req);

    gopherState->fwd = NULL;	// refcounted

    memFree(gopherState->buf, MEM_4K_BUF);
    gopherState->buf = NULL;
    cbdataFree(gopherState);
}

/**
 \ingroup ServerProtocolGopherInternal
 * Create MIME Header for Gopher Data
 */
static void
gopherMimeCreate(GopherStateData * gopherState)
{
    StoreEntry *entry = gopherState->entry;
    const char *mime_type = NULL;
    const char *mime_enc = NULL;

    switch (gopherState->type_id) {

    case GOPHER_DIRECTORY:

    case GOPHER_INDEX:

    case GOPHER_HTML:

    case GOPHER_WWW:

    case GOPHER_CSO:
        mime_type = "text/html";
        break;

    case GOPHER_GIF:

    case GOPHER_IMAGE:

    case GOPHER_PLUS_IMAGE:
        mime_type = "image/gif";
        break;

    case GOPHER_SOUND:

    case GOPHER_PLUS_SOUND:
        mime_type = "audio/basic";
        break;

    case GOPHER_PLUS_MOVIE:
        mime_type = "video/mpeg";
        break;

    case GOPHER_MACBINHEX:

    case GOPHER_DOSBIN:

    case GOPHER_UUENCODED:

    case GOPHER_BIN:
        /* Rightnow We have no idea what it is. */
        mime_enc = mimeGetContentEncoding(gopherState->request);
        mime_type = mimeGetContentType(gopherState->request);
        if (!mime_type)
            mime_type = def_gopher_bin;
        break;

    case GOPHER_FILE:

    default:
        mime_enc = mimeGetContentEncoding(gopherState->request);
        mime_type = mimeGetContentType(gopherState->request);
        if (!mime_type)
            mime_type = def_gopher_text;
        break;
    }

    assert(entry->isEmpty());
    EBIT_CLR(entry->flags, ENTRY_FWD_HDR_WAIT);

    HttpReply *reply = new HttpReply;
    entry->buffer();
    reply->setHeaders(HTTP_OK, "Gatewaying", mime_type, -1, -1, -2);
    if (mime_enc)
        reply->header.putStr(HDR_CONTENT_ENCODING, mime_enc);

    entry->replaceHttpReply(reply);
}

/**
 \ingroup ServerProtocolGopherInternal
 * Parse a gopher request into components.  By Anawat.
 */
static void
gopher_request_parse(const HttpRequest * req, char *type_id, char *request)
{
    const char *path = req->urlpath.termedBuf();

    if (request)
        request[0] = '\0';

    if (path && (*path == '/'))
        path++;

    if (!path || !*path) {
        *type_id = GOPHER_DIRECTORY;
        return;
    }

    *type_id = path[0];

    if (request) {
        xstrncpy(request, path + 1, MAX_URL);
        /* convert %xx to char */
        rfc1738_unescape(request);
    }
}

/**
 \ingroup ServerProtocolGopherAPI
 * Parse the request to determine whether it is cachable.
 *
 \param req	Request data.
 \retval 0	Not cachable.
 \retval 1	Cachable.
 */
int
gopherCachable(const HttpRequest * req)
{
    int cachable = 1;
    char type_id;
    /* parse to see type */
    gopher_request_parse(req,
                         &type_id,
                         NULL);

    switch (type_id) {

    case GOPHER_INDEX:

    case GOPHER_CSO:

    case GOPHER_TELNET:

    case GOPHER_3270:
        cachable = 0;
        break;

    default:
        cachable = 1;
    }

    return cachable;
}

/// \ingroup ServerProtocolGopherInternal
static void
gopherHTMLHeader(StoreEntry * e, const char *title, const char *substring)
{
    storeAppendPrintf(e, "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\" \"http://www.w3.org/TR/html4/loose.dtd\">\n");
    storeAppendPrintf(e, "<HTML><HEAD><TITLE>");
    storeAppendPrintf(e, title, substring);
    storeAppendPrintf(e, "</TITLE>");
    storeAppendPrintf(e, "<STYLE type=\"text/css\"><!--BODY{background-color:#ffffff;font-family:verdana,sans-serif}--></STYLE>\n");
    storeAppendPrintf(e, "</HEAD>\n<BODY><H1>");
    storeAppendPrintf(e, title, substring);
    storeAppendPrintf(e, "</H1>\n");
}

/// \ingroup ServerProtocolGopherInternal
static void
gopherHTMLFooter(StoreEntry * e)
{
    storeAppendPrintf(e, "<HR noshade size=\"1px\">\n");
    storeAppendPrintf(e, "<ADDRESS>\n");
    storeAppendPrintf(e, "Generated %s by %s (%s)\n",
                      mkrfc1123(squid_curtime),
                      getMyHostname(),
                      visible_appname_string);
    storeAppendPrintf(e, "</ADDRESS></BODY></HTML>\n");
}

/// \ingroup ServerProtocolGopherInternal
static void
gopherEndHTML(GopherStateData * gopherState)
{
    StoreEntry *e = gopherState->entry;

    if (!gopherState->HTML_header_added) {
        gopherHTMLHeader(e, "Server Return Nothing", NULL);
        storeAppendPrintf(e, "<P>The Gopher query resulted in a blank response</P>");
    } else if (gopherState->HTML_pre) {
        storeAppendPrintf(e, "</PRE>\n");
    }

    gopherHTMLFooter(e);
}

/**
 \ingroup ServerProtocolGopherInternal
 * Convert Gopher to HTML.
 \par
 * Borrow part of code from libwww2 came with Mosaic distribution.
 */
static void
gopherToHTML(GopherStateData * gopherState, char *inbuf, int len)
{
    char *pos = inbuf;
    char *lpos = NULL;
    char *tline = NULL;
    LOCAL_ARRAY(char, line, TEMP_BUF_SIZE);
    LOCAL_ARRAY(char, tmpbuf, TEMP_BUF_SIZE);
    char *name = NULL;
    char *selector = NULL;
    char *host = NULL;
    char *port = NULL;
    char *escaped_selector = NULL;
    const char *icon_url = NULL;
    char gtype;
    StoreEntry *entry = NULL;

    memset(tmpbuf, '\0', TEMP_BUF_SIZE);
    memset(line, '\0', TEMP_BUF_SIZE);

    entry = gopherState->entry;

    if (gopherState->conversion == gopher_ds::HTML_INDEX_PAGE) {
        char *html_url = html_quote(entry->url());
        gopherHTMLHeader(entry, "Gopher Index %s", html_url);
        storeAppendPrintf(entry,
                          "<p>This is a searchable Gopher index. Use the search\n"
                          "function of your browser to enter search terms.\n"
                          "<ISINDEX>\n");
        gopherHTMLFooter(entry);
        /* now let start sending stuff to client */
        entry->flush();
        gopherState->HTML_header_added = 1;

        return;
    }

    if (gopherState->conversion == gopher_ds::HTML_CSO_PAGE) {
        char *html_url = html_quote(entry->url());
        gopherHTMLHeader(entry, "CSO Search of %s", html_url);
        storeAppendPrintf(entry,
                          "<P>A CSO database usually contains a phonebook or\n"
                          "directory.  Use the search function of your browser to enter\n"
                          "search terms.</P><ISINDEX>\n");
        gopherHTMLFooter(entry);
        /* now let start sending stuff to client */
        entry->flush();
        gopherState->HTML_header_added = 1;

        return;
    }

    inbuf[len] = '\0';
    String outbuf;

    if (!gopherState->HTML_header_added) {
        if (gopherState->conversion == gopher_ds::HTML_CSO_RESULT)
            gopherHTMLHeader(entry, "CSO Search Result", NULL);
        else
            gopherHTMLHeader(entry, "Gopher Menu", NULL);

        outbuf.append ("<PRE>");

        gopherState->HTML_header_added = 1;

        gopherState->HTML_pre = 1;
    }

    while ((pos != NULL) && (pos < inbuf + len)) {

        if (gopherState->len != 0) {
            /* there is something left from last tx. */
            xstrncpy(line, gopherState->buf, gopherState->len + 1);

            if (gopherState->len + len > TEMP_BUF_SIZE) {
                debugs(10, 1, "GopherHTML: Buffer overflow. Lost some data on URL: " << entry->url()  );
                len = TEMP_BUF_SIZE - gopherState->len;
            }

            lpos = (char *) memccpy(line + gopherState->len, inbuf, '\n', len);

            if (lpos)
                *lpos = '\0';
            else {
                /* there is no complete line in inbuf */
                /* copy it to temp buffer */

                if (gopherState->len + len > TEMP_BUF_SIZE) {
                    debugs(10, 1, "GopherHTML: Buffer overflow. Lost some data on URL: " << entry->url()  );
                    len = TEMP_BUF_SIZE - gopherState->len;
                }

                xmemcpy(gopherState->buf + gopherState->len, inbuf, len);
                gopherState->len += len;
                return;
            }

            /* skip one line */
            pos = (char *) memchr(pos, '\n', len);

            if (pos)
                pos++;

            /* we're done with the remain from last tx. */
            gopherState->len = 0;

            *(gopherState->buf) = '\0';
        } else {

            lpos = (char *) memccpy(line, pos, '\n', len - (pos - inbuf));

            if (lpos)
                *lpos = '\0';
            else {
                /* there is no complete line in inbuf */
                /* copy it to temp buffer */

                if ((len - (pos - inbuf)) > TEMP_BUF_SIZE) {
                    debugs(10, 1, "GopherHTML: Buffer overflow. Lost some data on URL: " << entry->url()  );
                    len = TEMP_BUF_SIZE;
                }

                if (len > (pos - inbuf)) {
                    xmemcpy(gopherState->buf, pos, len - (pos - inbuf));
                    gopherState->len = len - (pos - inbuf);
                }

                break;
            }

            /* skip one line */
            pos = (char *) memchr(pos, '\n', len);

            if (pos)
                pos++;

        }

        /* at this point. We should have one line in buffer to process */

        if (*line == '.') {
            /* skip it */
            memset(line, '\0', TEMP_BUF_SIZE);
            continue;
        }

        switch (gopherState->conversion) {

        case gopher_ds::HTML_INDEX_RESULT:

        case gopher_ds::HTML_DIR: {
            tline = line;
            gtype = *tline++;
            name = tline;
            selector = strchr(tline, TAB);

            if (selector) {
                *selector++ = '\0';
                host = strchr(selector, TAB);

                if (host) {
                    *host++ = '\0';
                    port = strchr(host, TAB);

                    if (port) {
                        char *junk;
                        port[0] = ':';
                        junk = strchr(host, TAB);

                        if (junk)
                            *junk++ = 0;	/* Chop port */
                        else {
                            junk = strchr(host, '\r');

                            if (junk)
                                *junk++ = 0;	/* Chop port */
                            else {
                                junk = strchr(host, '\n');

                                if (junk)
                                    *junk++ = 0;	/* Chop port */
                            }
                        }

                        if ((port[1] == '0') && (!port[2]))
                            port[0] = 0;	/* 0 means none */
                    }

                    /* escape a selector here */
                    escaped_selector = xstrdup(rfc1738_escape_part(selector));

                    switch (gtype) {

                    case GOPHER_DIRECTORY:
                        icon_url = mimeGetIconURL("internal-menu");
                        break;

                    case GOPHER_HTML:

                    case GOPHER_FILE:
                        icon_url = mimeGetIconURL("internal-text");
                        break;

                    case GOPHER_INDEX:

                    case GOPHER_CSO:
                        icon_url = mimeGetIconURL("internal-index");
                        break;

                    case GOPHER_IMAGE:

                    case GOPHER_GIF:

                    case GOPHER_PLUS_IMAGE:
                        icon_url = mimeGetIconURL("internal-image");
                        break;

                    case GOPHER_SOUND:

                    case GOPHER_PLUS_SOUND:
                        icon_url = mimeGetIconURL("internal-sound");
                        break;

                    case GOPHER_PLUS_MOVIE:
                        icon_url = mimeGetIconURL("internal-movie");
                        break;

                    case GOPHER_TELNET:

                    case GOPHER_3270:
                        icon_url = mimeGetIconURL("internal-telnet");
                        break;

                    case GOPHER_BIN:

                    case GOPHER_MACBINHEX:

                    case GOPHER_DOSBIN:

                    case GOPHER_UUENCODED:
                        icon_url = mimeGetIconURL("internal-binary");
                        break;

                    case GOPHER_INFO:
                        icon_url = NULL;
                        break;

                    default:
                        icon_url = mimeGetIconURL("internal-unknown");
                        break;
                    }

                    memset(tmpbuf, '\0', TEMP_BUF_SIZE);

                    if ((gtype == GOPHER_TELNET) || (gtype == GOPHER_3270)) {
                        if (strlen(escaped_selector) != 0)
                            snprintf(tmpbuf, TEMP_BUF_SIZE, "<IMG border=\"0\" SRC=\"%s\"> <A HREF=\"telnet://%s@%s%s%s/\">%s</A>\n",
                                     icon_url, escaped_selector, rfc1738_escape_part(host),
                                     *port ? ":" : "", port, html_quote(name));
                        else
                            snprintf(tmpbuf, TEMP_BUF_SIZE, "<IMG border=\"0\" SRC=\"%s\"> <A HREF=\"telnet://%s%s%s/\">%s</A>\n",
                                     icon_url, rfc1738_escape_part(host), *port ? ":" : "",
                                     port, html_quote(name));

                    } else if (gtype == GOPHER_INFO) {
                        snprintf(tmpbuf, TEMP_BUF_SIZE, "\t%s\n", html_quote(name));
                    } else {
                        if (strncmp(selector, "GET /", 5) == 0) {
                            /* WWW link */
                            snprintf(tmpbuf, TEMP_BUF_SIZE, "<IMG border=\"0\" SRC=\"%s\"> <A HREF=\"http://%s/%s\">%s</A>\n",
                                     icon_url, host, rfc1738_escape_unescaped(selector + 5), html_quote(name));
                        } else {
                            /* Standard link */
                            snprintf(tmpbuf, TEMP_BUF_SIZE, "<IMG border=\"0\" SRC=\"%s\"> <A HREF=\"gopher://%s/%c%s\">%s</A>\n",
                                     icon_url, host, gtype, escaped_selector, html_quote(name));
                        }
                    }

                    safe_free(escaped_selector);
                    outbuf.append(tmpbuf);
                } else {
                    memset(line, '\0', TEMP_BUF_SIZE);
                    continue;
                }
            } else {
                memset(line, '\0', TEMP_BUF_SIZE);
                continue;
            }

            break;
        }			/* HTML_DIR, HTML_INDEX_RESULT */


        case gopher_ds::HTML_CSO_RESULT: {
            if (line[0] == '-') {
                int code, recno;
                char *s_code, *s_recno, *result;

                s_code = strtok(line + 1, ":\n");
                s_recno = strtok(NULL, ":\n");
                result = strtok(NULL, "\n");

                if (!result)
                    break;

                code = atoi(s_code);

                recno = atoi(s_recno);

                if (code != 200)
                    break;

                if (gopherState->cso_recno != recno) {
                    snprintf(tmpbuf, TEMP_BUF_SIZE, "</PRE><HR noshade size=\"1px\"><H2>Record# %d<br><i>%s</i></H2>\n<PRE>", recno, html_quote(result));
                    gopherState->cso_recno = recno;
                } else {
                    snprintf(tmpbuf, TEMP_BUF_SIZE, "%s\n", html_quote(result));
                }

                outbuf.append(tmpbuf);
                break;
            } else {
                int code;
                char *s_code, *result;

                s_code = strtok(line, ":");
                result = strtok(NULL, "\n");

                if (!result)
                    break;

                code = atoi(s_code);

                switch (code) {

                case 200: {
                    /* OK */
                    /* Do nothing here */
                    break;
                }

                case 102:	/* Number of matches */

                case 501:	/* No Match */

                case 502: {	/* Too Many Matches */
                    /* Print the message the server returns */
                    snprintf(tmpbuf, TEMP_BUF_SIZE, "</PRE><HR noshade size=\"1px\"><H2>%s</H2>\n<PRE>", html_quote(result));
                    outbuf.append(tmpbuf);
                    break;
                }


                }
            }

        }			/* HTML_CSO_RESULT */

        default:
            break;		/* do nothing */

        }			/* switch */

    }				/* while loop */

    if (outbuf.size() > 0) {
        entry->append(outbuf.rawBuf(), outbuf.size());
        /* now let start sending stuff to client */
        entry->flush();
    }

    outbuf.clean();
    return;
}

/// \ingroup ServerProtocolGopherInternal
static void
gopherTimeout(int fd, void *data)
{
    GopherStateData *gopherState = (GopherStateData *)data;
    StoreEntry *entry = gopherState->entry;
    debugs(10, 4, "gopherTimeout: FD " << fd << ": '" << entry->url() << "'" );

    gopherState->fwd->fail(errorCon(ERR_READ_TIMEOUT, HTTP_GATEWAY_TIMEOUT, gopherState->fwd->request));

    comm_close(fd);
}

/**
 \ingroup ServerProtocolGopherInternal
 * This will be called when data is ready to be read from fd.
 * Read until error or connection closed.
 */
static void
gopherReadReply(int fd, char *buf, size_t len, comm_err_t flag, int xerrno, void *data)
{
    GopherStateData *gopherState = (GopherStateData *)data;
    StoreEntry *entry = gopherState->entry;
    int clen;
    int bin;
    size_t read_sz = BUFSIZ;
    int do_next_read = 0;
#if DELAY_POOLS

    DelayId delayId = entry->mem_obj->mostBytesAllowed();
#endif

    /* Bail out early on COMM_ERR_CLOSING - close handlers will tidy up for us */

    if (flag == COMM_ERR_CLOSING) {
        return;
    }

    assert(buf == gopherState->replybuf);

    if (EBIT_TEST(entry->flags, ENTRY_ABORTED)) {
        comm_close(fd);
        return;
    }

    errno = 0;
#if DELAY_POOLS

    read_sz = delayId.bytesWanted(1, read_sz);
#endif

    /* leave one space for \0 in gopherToHTML */

    if (flag == COMM_OK && len > 0) {
#if DELAY_POOLS
        delayId.bytesIn(len);
#endif

        kb_incr(&statCounter.server.all.kbytes_in, len);
        kb_incr(&statCounter.server.other.kbytes_in, len);
    }

    debugs(10, 5, "gopherReadReply: FD " << fd << " read len=" << len);

    if (flag == COMM_OK && len > 0) {
        commSetTimeout(fd, Config.Timeout.read, NULL, NULL);
        IOStats.Gopher.reads++;

        for (clen = len - 1, bin = 0; clen; bin++)
            clen >>= 1;

        IOStats.Gopher.read_hist[bin]++;
    }

    if (flag != COMM_OK || len < 0) {
        debugs(50, 1, "gopherReadReply: error reading: " << xstrerror());

        if (ignoreErrno(errno)) {
            do_next_read = 1;
        } else {
            ErrorState *err;
            err = errorCon(ERR_READ_ERROR, HTTP_INTERNAL_SERVER_ERROR, gopherState->fwd->request);
            err->xerrno = errno;
            gopherState->fwd->fail(err);
            comm_close(fd);
            do_next_read = 0;
        }
    } else if (len == 0 && entry->isEmpty()) {
        gopherState->fwd->fail(errorCon(ERR_ZERO_SIZE_OBJECT, HTTP_SERVICE_UNAVAILABLE, gopherState->fwd->request));
        comm_close(fd);
        do_next_read = 0;
    } else if (len == 0) {
        /* Connection closed; retrieval done. */
        /* flush the rest of data in temp buf if there is one. */

        if (gopherState->conversion != gopher_ds::NORMAL)
            gopherEndHTML(gopherState);

        entry->timestampsSet();

        entry->flush();

        gopherState->fwd->complete();

        comm_close(fd);

        do_next_read = 0;
    } else {
        if (gopherState->conversion != gopher_ds::NORMAL) {
            gopherToHTML(gopherState, buf, len);
        } else {
            entry->append(buf, len);
        }

        do_next_read = 1;
    }

    if (do_next_read)
        comm_read(fd, buf, read_sz, gopherReadReply, gopherState);

    return;
}

/**
 \ingroup ServerProtocolGopherInternal
 * This will be called when request write is complete. Schedule read of reply.
 */
static void
gopherSendComplete(int fd, char *buf, size_t size, comm_err_t errflag, int xerrno, void *data)
{
    GopherStateData *gopherState = (GopherStateData *) data;
    StoreEntry *entry = gopherState->entry;
    debugs(10, 5, "gopherSendComplete: FD " << fd << " size: " << size << " errflag: " << errflag);

    if (size > 0) {
        fd_bytes(fd, size, FD_WRITE);
        kb_incr(&statCounter.server.all.kbytes_out, size);
        kb_incr(&statCounter.server.other.kbytes_out, size);
    }

    if (errflag) {
        ErrorState *err;
        err = errorCon(ERR_WRITE_ERROR, HTTP_SERVICE_UNAVAILABLE, gopherState->fwd->request);
        err->xerrno = errno;
        err->port = gopherState->req->port;
        err->url = xstrdup(entry->url());
        gopherState->fwd->fail(err);
        comm_close(fd);

        if (buf)
            memFree(buf, MEM_4K_BUF);	/* Allocated by gopherSendRequest. */

        return;
    }

    /*
     * OK. We successfully reach remote site.  Start MIME typing
     * stuff.  Do it anyway even though request is not HTML type.
     */
    entry->buffer();

    gopherMimeCreate(gopherState);

    switch (gopherState->type_id) {

    case GOPHER_DIRECTORY:
        /* we got to convert it first */
        gopherState->conversion = gopher_ds::HTML_DIR;
        gopherState->HTML_header_added = 0;
        break;

    case GOPHER_INDEX:
        /* we got to convert it first */
        gopherState->conversion = gopher_ds::HTML_INDEX_RESULT;
        gopherState->HTML_header_added = 0;
        break;

    case GOPHER_CSO:
        /* we got to convert it first */
        gopherState->conversion = gopher_ds::HTML_CSO_RESULT;
        gopherState->cso_recno = 0;
        gopherState->HTML_header_added = 0;
        break;

    default:
        gopherState->conversion = gopher_ds::NORMAL;
        entry->flush();
    }

    /* Schedule read reply. */
    AsyncCall::Pointer call =  commCbCall(10,5, "gopherReadReply",
                                          CommIoCbPtrFun(gopherReadReply, gopherState));
    entry->delayAwareRead(fd, gopherState->replybuf, BUFSIZ, call);

    if (buf)
        memFree(buf, MEM_4K_BUF);	/* Allocated by gopherSendRequest. */
}

/**
 \ingroup ServerProtocolGopherInternal
 * This will be called when connect completes. Write request.
 */
static void
gopherSendRequest(int fd, void *data)
{
    GopherStateData *gopherState = (GopherStateData *)data;
    char *buf = (char *)memAllocate(MEM_4K_BUF);

    if (gopherState->type_id == GOPHER_CSO) {
        const char *t = strchr(gopherState->request, '?');

        if (t != NULL)
            t++;		/* skip the ? */
        else
            t = "";

        snprintf(buf, 4096, "query %s\r\nquit\r\n", t);
    } else if (gopherState->type_id == GOPHER_INDEX) {
        char *t = strchr(gopherState->request, '?');

        if (t != NULL)
            *t = '\t';

        snprintf(buf, 4096, "%s\r\n", gopherState->request);
    } else {
        snprintf(buf, 4096, "%s\r\n", gopherState->request);
    }

    debugs(10, 5, "gopherSendRequest: FD " << fd);
    comm_write(fd, buf, strlen(buf), gopherSendComplete, gopherState, NULL);

    if (EBIT_TEST(gopherState->entry->flags, ENTRY_CACHABLE))
        gopherState->entry->setPublicKey();	/* Make it public */
}

/// \ingroup ServerProtocolGopherInternal
CBDATA_TYPE(GopherStateData);

/// \ingroup ServerProtocolGopherAPI
void
gopherStart(FwdState * fwd)
{
    int fd = fwd->server_fd;
    StoreEntry *entry = fwd->entry;
    GopherStateData *gopherState;
    CBDATA_INIT_TYPE(GopherStateData);
    gopherState = cbdataAlloc(GopherStateData);
    gopherState->buf = (char *)memAllocate(MEM_4K_BUF);

    entry->lock();
    gopherState->entry = entry;

    gopherState->fwd = fwd;

    debugs(10, 3, "gopherStart: " << entry->url()  );

    statCounter.server.all.requests++;

    statCounter.server.other.requests++;

    /* Parse url. */
    gopher_request_parse(fwd->request,
                         &gopherState->type_id, gopherState->request);

    comm_add_close_handler(fd, gopherStateFree, gopherState);

    if (((gopherState->type_id == GOPHER_INDEX) || (gopherState->type_id == GOPHER_CSO))
            && (strchr(gopherState->request, '?') == NULL)) {
        /* Index URL without query word */
        /* We have to generate search page back to client. No need for connection */
        gopherMimeCreate(gopherState);

        if (gopherState->type_id == GOPHER_INDEX) {
            gopherState->conversion = gopher_ds::HTML_INDEX_PAGE;
        } else {
            if (gopherState->type_id == GOPHER_CSO) {
                gopherState->conversion = gopher_ds::HTML_CSO_PAGE;
            } else {
                gopherState->conversion = gopher_ds::HTML_INDEX_PAGE;
            }
        }

        gopherToHTML(gopherState, (char *) NULL, 0);
        fwd->complete();
        comm_close(fd);
        return;
    }

    gopherState->fd = fd;
    gopherState->fwd = fwd;
    gopherSendRequest(fd, gopherState);
    commSetTimeout(fd, Config.Timeout.read, gopherTimeout, gopherState);
}
