Bug #890: Various HTTP workarounds and minor corrections

[thirdparty/squid.git] / src / HttpMsg.cc

/*
 * $Id: HttpMsg.cc,v 1.14 2005/03/06 21:08:13 serassio Exp $
 *
 * DEBUG: section 74    HTTP Message
 * AUTHOR: Alex Rousskov
 *
 * 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 "HttpVersion.h"

/* find end of headers */
int
httpMsgIsolateHeaders(const char **parse_start, const char **blk_start, const char **blk_end)
{
    /*
     * parse_start points to the first line of HTTP message *headers*,
     * not including the request or status lines
     */
    size_t l = strlen(*parse_start);
    size_t end = headersEnd(*parse_start, l);
    int nnl;

    if (end) {
        *blk_start = *parse_start;
        *blk_end = *parse_start + end - 1;
        /*
         * leave blk_end pointing to the first character after the
         * first newline which terminates the headers
         */
        assert(**blk_end == '\n');

        while (*(*blk_end - 1) == '\r')
            (*blk_end)--;

        assert(*(*blk_end - 1) == '\n');

        *parse_start += end;

        return 1;
    }

    /*
     * If we didn't find the end of headers, and parse_start does
     * NOT point to a CR or NL character, then return failure
     */
    if (**parse_start != '\r' && **parse_start != '\n')
        return 0;		/* failure */

    /*
     * If we didn't find the end of headers, and parse_start does point
     * to an empty line, then we have empty headers.  Skip all CR and
     * NL characters up to the first NL.  Leave parse_start pointing at
     * the first character after the first NL.
     */
    *blk_start = *parse_start;

    *blk_end = *blk_start;

    for (nnl = 0; nnl == 0; (*parse_start)++) {
        if (**parse_start == '\r')
            (void) 0;
        else if (**parse_start == '\n')
            nnl++;
        else
            break;
    }

    return 1;
}

/* returns true if connection should be "persistent"
 * after processing this message */
int
httpMsgIsPersistent(HttpVersion const &http_ver, const HttpHeader * hdr)
{
#if WHEN_SQUID_IS_NOT_HTTP1_1

    if ((http_ver.major >= 1) && (http_ver.minor >= 1)) {
        /*
         * for modern versions of HTTP: persistent unless there is
         * a "Connection: close" header.
         */
        return !httpHeaderHasConnDir(hdr, "close");
    } else {
#else
    {
#endif
        /*
         * Persistent connections in Netscape 3.x are allegedly broken,
         * return false if it is a browser connection.  If there is a
         * VIA header, then we assume this is NOT a browser connection.
         */
        const char *agent = httpHeaderGetStr(hdr, HDR_USER_AGENT);

        if (agent && !httpHeaderHas(hdr, HDR_VIA))
        {
            if (!strncasecmp(agent, "Mozilla/3.", 10))
                return 0;

            if (!strncasecmp(agent, "Netscape/3.", 11))
                return 0;
        }

        /* for old versions of HTTP: persistent if has "keep-alive" */
        return httpHeaderHasConnDir(hdr, "keep-alive");
    }
}