proxy_http.c

精通tomcat书籍原代码,希望大家共同学习

        { NULL, NULL }
    } ;
    int i ;
    for ( i = 0 ; date_hdrs[i] ; ++i ) {
        if ( !strcasecmp(date_hdrs[i], key) ) {
            apr_table_add(r->headers_out, key,
                ap_proxy_date_canon(r->pool, value)) ;
            return ;
        }
    }
    for ( i = 0 ; transform_hdrs[i].name ; ++i ) {
        if ( !strcasecmp(transform_hdrs[i].name, key) ) {
            apr_table_add(r->headers_out, key,
                (*transform_hdrs[i].func)(r, c, value)) ;
            return ;
       }
    }
    apr_table_add(r->headers_out, key, value) ;
    return ;
}

static void ap_proxy_read_headers(request_rec *r, request_rec *rr, char *buffer, int size, conn_rec *c)
{
    int len;
    char *value, *end;
    char field[MAX_STRING_LEN];
    int saw_headers = 0;
    void *sconf = r->server->module_config;
    proxy_server_conf *psc;

    psc = (proxy_server_conf *) ap_get_module_config(sconf, &proxy_module);

    r->headers_out = apr_table_make(r->pool, 20);

    /*
     * Read header lines until we get the empty separator line, a read error,
     * the connection closes (EOF), or we timeout.
     */
    while ((len = ap_getline(buffer, size, rr, 1)) > 0) {

        if (!(value = strchr(buffer, ':'))) {     /* Find the colon separator */

            /* We may encounter invalid headers, usually from buggy
             * MS IIS servers, so we need to determine just how to handle
             * them. We can either ignore them, assume that they mark the
             * start-of-body (eg: a missing CRLF) or (the default) mark
             * the headers as totally bogus and return a 500. The sole
             * exception is an extra "HTTP/1.0 200, OK" line sprinkled
             * in between the usual MIME headers, which is a favorite
             * IIS bug.
             */
             /* XXX: The mask check is buggy if we ever see an HTTP/1.10 */

            if (!apr_date_checkmask(buffer, "HTTP/#.# ###*")) {
                if (psc->badopt == bad_error) {
                    /* Nope, it wasn't even an extra HTTP header. Give up. */
                    return ;
                }
                else if (psc->badopt == bad_body) {
                    /* if we've already started loading headers_out, then
                     * return what we've accumulated so far, in the hopes
                     * that they are useful. Otherwise, we completely bail.
                     */
                    /* FIXME: We've already scarfed the supposed 1st line of
                     * the body, so the actual content may end up being bogus
                     * as well. If the content is HTML, we may be lucky.
                     */
                    if (saw_headers) {
                        ap_log_error(APLOG_MARK, APLOG_WARNING, 0, r->server,
                         "proxy: Starting body due to bogus non-header in headers "
                         "returned by %s (%s)", r->uri, r->method);
                        return ;
                    } else {
                         ap_log_error(APLOG_MARK, APLOG_WARNING, 0, r->server,
                         "proxy: No HTTP headers "
                         "returned by %s (%s)", r->uri, r->method);
                        return ;
                    }
                }
            }
            /* this is the psc->badopt == bad_ignore case */
            ap_log_error(APLOG_MARK, APLOG_WARNING, 0, r->server,
                         "proxy: Ignoring bogus HTTP header "
                         "returned by %s (%s)", r->uri, r->method);
            continue;
        }

        *value = '\0';
        ++value;
        /* XXX: RFC2068 defines only SP and HT as whitespace, this test is
         * wrong... and so are many others probably.
         */
        while (apr_isspace(*value))
            ++value;            /* Skip to start of value   */

        /* should strip trailing whitespace as well */
        for (end = &value[strlen(value)-1]; end > value && apr_isspace(*end); --
end)
            *end = '\0';

        /* make sure we add so as not to destroy duplicated headers
         * Modify headers requiring canonicalisation and/or affected
         * by ProxyPassReverse and family with process_proxy_header
         */
        process_proxy_header(r, psc, buffer, value) ;
        saw_headers = 1;

        /* the header was too long; at the least we should skip extra data */
        if (len >= size - 1) {
            while ((len = ap_getline(field, MAX_STRING_LEN, rr, 1))
                    >= MAX_STRING_LEN - 1) {
                /* soak up the extra data */
            }
            if (len == 0) /* time to exit the larger loop as well */
                break;
        }
    }
}



static int addit_dammit(void *v, const char *key, const char *val)
{
    apr_table_addn(v, key, val);
    return 1;
}

static
apr_status_t ap_proxy_http_process_response(apr_pool_t * p, request_rec *r,
                                            proxy_conn_rec *backend,
                                            conn_rec *origin,
                                            proxy_server_conf *conf,
                                            char *server_portstr) {
    conn_rec *c = r->connection;
    char buffer[HUGE_STRING_LEN];
    char keepchar;
    request_rec *rp;
    apr_bucket *e;
    apr_bucket_brigade *bb;
    int len, backasswards;
    int interim_response; /* non-zero whilst interim 1xx responses
                           * are being read. */
    apr_table_t *save_table;

    bb = apr_brigade_create(p, c->bucket_alloc);

    /* Get response from the remote server, and pass it up the
     * filter chain
     */

    rp = ap_proxy_make_fake_req(origin, r);
    /* In case anyone needs to know, this is a fake request that is really a
     * response.
     */
    rp->proxyreq = PROXYREQ_RESPONSE;

    do {
        apr_brigade_cleanup(bb);

        len = ap_getline(buffer, sizeof(buffer), rp, 0);
        if (len == 0) {
            /* handle one potential stray CRLF */
            len = ap_getline(buffer, sizeof(buffer), rp, 0);
        }
        if (len <= 0) {
            ap_proxy_http_cleanup(NULL, r, backend);
            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
                          "proxy: error reading status line from remote "
                          "server %s", backend->hostname);
            return ap_proxyerror(r, HTTP_BAD_GATEWAY,
                                 "Error reading from remote server");
        }

       /* Is it an HTTP/1 response?
        * This is buggy if we ever see an HTTP/1.10
        */
        if (apr_date_checkmask(buffer, "HTTP/#.# ###*")) {
            int major, minor;

            if (2 != sscanf(buffer, "HTTP/%u.%u", &major, &minor)) {
                major = 1;
                minor = 1;
            }
            /* If not an HTTP/1 message or
             * if the status line was > 8192 bytes
             */
            else if ((buffer[5] != '1') || (len >= sizeof(buffer)-1)) {
                ap_proxy_http_cleanup(NULL, r, backend);
                return ap_proxyerror(r, HTTP_BAD_GATEWAY,
                apr_pstrcat(p, "Corrupt status line returned by remote "
                            "server: ", buffer, NULL));
            }
            backasswards = 0;

            keepchar = buffer[12];
            buffer[12] = '\0';
            r->status = atoi(&buffer[9]);

            if (keepchar != '\0') {
                buffer[12] = keepchar;
            } else {
                /* 2616 requires the space in Status-Line; the origin
                 * server may have sent one but ap_rgetline_core will
                 * have stripped it. */
                buffer[12] = ' ';
                buffer[13] = '\0';
            }
            r->status_line = apr_pstrdup(p, &buffer[9]);
            

            /* read the headers. */
            /* N.B. for HTTP/1.0 clients, we have to fold line-wrapped headers*/
            /* Also, take care with headers with multiple occurences. */

            /* First, tuck away all already existing cookies */
            save_table = apr_table_make(r->pool, 2);
            apr_table_do(addit_dammit, save_table, r->headers_out,
                         "Set-Cookie", NULL);

	    /* shove the headers direct into r->headers_out */
            ap_proxy_read_headers(r, rp, buffer, sizeof(buffer), origin);

            if (r->headers_out == NULL) {
                ap_log_error(APLOG_MARK, APLOG_WARNING, 0,
                             r->server, "proxy: bad HTTP/%d.%d header "
                             "returned by %s (%s)", major, minor, r->uri,
                             r->method);
                backend->close += 1;
                /*
                 * ap_send_error relies on a headers_out to be present. we
                 * are in a bad position here.. so force everything we send out
                 * to have nothing to do with the incoming packet
                 */
                r->headers_out = apr_table_make(r->pool,1);
                r->status = HTTP_BAD_GATEWAY;
                r->status_line = "bad gateway";
                return r->status;

            } else {
                const char *buf;

                /* Now, add in the just read cookies */
                apr_table_do(addit_dammit, save_table, r->headers_out,
        	             "Set-Cookie", NULL);

                /* and now load 'em all in */
                if (!apr_is_empty_table(save_table)) {
                    apr_table_unset(r->headers_out, "Set-Cookie");
                    r->headers_out = apr_table_overlay(r->pool,
                                                       r->headers_out,
                                                       save_table);
                }
                
                /* strip connection listed hop-by-hop headers from response */
                backend->close += ap_proxy_liststr(apr_table_get(r->headers_out,
                                                                 "Connection"),
                                                  "close");
                ap_proxy_clear_connection(p, r->headers_out);
                if ((buf = apr_table_get(r->headers_out, "Content-Type"))) {
                    ap_set_content_type(r, apr_pstrdup(p, buf));
                }            
                ap_proxy_pre_http_request(origin,rp);
            }

            /* handle Via header in response */
            if (conf->viaopt != via_off && conf->viaopt != via_block) {
                const char *server_name = ap_get_server_name(r);
                /* If USE_CANONICAL_NAME_OFF was configured for the proxy virtual host,
                 * then the server name returned by ap_get_server_name() is the
                 * origin server name (which does make too much sense with Via: headers)
                 * so we use the proxy vhost's name instead.
                 */
                if (server_name == r->hostname)
                    server_name = r->server->server_hostname;
                /* create a "Via:" response header entry and merge it */
                apr_table_mergen(r->headers_out, "Via",
                                 (conf->viaopt == via_full)
                                     ? apr_psprintf(p, "%d.%d %s%s (%s)",
                                           HTTP_VERSION_MAJOR(r->proto_num),
                                           HTTP_VERSION_MINOR(r->proto_num),
                                           server_name,
                                           server_portstr,
                                           AP_SERVER_BASEVERSION)
                                     : apr_psprintf(p, "%d.%d %s%s",
                                           HTTP_VERSION_MAJOR(r->proto_num),
                                           HTTP_VERSION_MINOR(r->proto_num),
                                           server_name,
                                           server_portstr)
                );
            }

            /* cancel keepalive if HTTP/1.0 or less */
            if ((major < 1) || (minor < 1)) {
                backend->close += 1;
                origin->keepalive = AP_CONN_CLOSE;
            }
        } else {
            /* an http/0.9 response */
            backasswards = 1;
            r->status = 200;
            r->status_line = "200 OK";
            backend->close += 1;
        }

        interim_response = ap_is_HTTP_INFO(r->status);
        if (interim_response) {
            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, NULL,
                         "proxy: HTTP: received interim %d response",
                         r->status);
        }
        /* Moved the fixups of Date headers and those affected by
         * ProxyPassReverse/etc from here to ap_proxy_read_headers
         */

        if ((r->status == 401) && (conf->error_override != 0)) {
            const char *buf;