mod_proxy_http.c

apache服务器源代码（版本号：2.2.2）

        cl_val = atol(old_cl_val);
    }
    terminate_headers(bucket_alloc, header_brigade);

    while (!APR_BUCKET_IS_EOS(APR_BRIGADE_FIRST(input_brigade)))
    {
        apr_brigade_length(input_brigade, 1, &bytes);
        bytes_streamed += bytes;

        /* If this brigade contains EOS, either stop or remove it. */
        if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))) {
            seen_eos = 1;

            /* We can't pass this EOS to the output_filters. */
            e = APR_BRIGADE_LAST(input_brigade);
            apr_bucket_delete(e);
        }

        /* C-L < bytes streamed?!?
         * We will error out after the body is completely
         * consumed, but we can't stream more bytes at the
         * back end since they would in part be interpreted
         * as another request!  If nothing is sent, then
         * just send nothing.
         *
         * Prevents HTTP Response Splitting.
         */
        if (bytes_streamed > cl_val)
             continue;

        if (header_brigade) {
            /* we never sent the header brigade, so go ahead and
             * take care of that now
             */
            bb = header_brigade;

            /*
             * Save input_brigade in bb brigade. (At least) in the SSL case
             * input_brigade contains transient buckets whose data would get
             * overwritten during the next call of ap_get_brigade in the loop.
             * ap_save_brigade ensures these buckets to be set aside.
             * Calling ap_save_brigade with NULL as filter is OK, because
             * bb brigade already has been created and does not need to get
             * created by ap_save_brigade.
             */
            status = ap_save_brigade(NULL, &bb, &input_brigade, p);
            if (status != APR_SUCCESS) {
                return status;
            }

            header_brigade = NULL;
        }
        else {
            bb = input_brigade;
        }

        /* Once we hit EOS, we are ready to flush. */
        status = pass_brigade(bucket_alloc, r, p_conn, origin, bb, seen_eos);
        if (status != APR_SUCCESS) {
            return status;
        }

        if (seen_eos) {
            break;
        }

        status = ap_get_brigade(r->input_filters, input_brigade,
                                AP_MODE_READBYTES, APR_BLOCK_READ,
                                HUGE_STRING_LEN);

        if (status != APR_SUCCESS) {
            return status;
        }
    }

    if (bytes_streamed != cl_val) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server,
                     "proxy: client %s given Content-Length did not match"
                     " number of body bytes read", r->connection->remote_ip);
        return APR_EOF;
    }

    if (header_brigade) {
        /* we never sent the header brigade since there was no request
         * body; send it now with the flush flag
         */
        bb = header_brigade;
        status = pass_brigade(bucket_alloc, r, p_conn, origin, bb, 1);
    }
    return status;
}

static apr_status_t spool_reqbody_cl(apr_pool_t *p,
                                     request_rec *r,
                                     proxy_conn_rec *p_conn,
                                     conn_rec *origin,
                                     apr_bucket_brigade *header_brigade,
                                     apr_bucket_brigade *input_brigade,
                                     int force_cl)
{
    int seen_eos = 0;
    apr_status_t status;
    apr_bucket_alloc_t *bucket_alloc = r->connection->bucket_alloc;
    apr_bucket_brigade *body_brigade;
    apr_bucket *e;
    apr_off_t bytes, bytes_spooled = 0, fsize = 0;
    apr_file_t *tmpfile = NULL;

    body_brigade = apr_brigade_create(p, bucket_alloc);

    while (!APR_BUCKET_IS_EOS(APR_BRIGADE_FIRST(input_brigade)))
    {
        /* If this brigade contains EOS, either stop or remove it. */
        if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))) {
            seen_eos = 1;

            /* We can't pass this EOS to the output_filters. */
            e = APR_BRIGADE_LAST(input_brigade);
            apr_bucket_delete(e);
        }

        apr_brigade_length(input_brigade, 1, &bytes);

        if (bytes_spooled + bytes > MAX_MEM_SPOOL) {
            /* can't spool any more in memory; write latest brigade to disk */
            if (tmpfile == NULL) {
                const char *temp_dir;
                char *template;

                status = apr_temp_dir_get(&temp_dir, p);
                if (status != APR_SUCCESS) {
                    ap_log_error(APLOG_MARK, APLOG_ERR, status, r->server,
                                 "proxy: search for temporary directory failed");
                    return status;
                }
                apr_filepath_merge(&template, temp_dir,
                                   "modproxy.tmp.XXXXXX",
                                   APR_FILEPATH_NATIVE, p);
                status = apr_file_mktemp(&tmpfile, template, 0, p);
                if (status != APR_SUCCESS) {
                    ap_log_error(APLOG_MARK, APLOG_ERR, status, r->server,
                                 "proxy: creation of temporary file in directory %s failed",
                                 temp_dir);
                    return status;
                }
            }
            for (e = APR_BRIGADE_FIRST(input_brigade);
                 e != APR_BRIGADE_SENTINEL(input_brigade);
                 e = APR_BUCKET_NEXT(e)) {
                const char *data;
                apr_size_t bytes_read, bytes_written;

                apr_bucket_read(e, &data, &bytes_read, APR_BLOCK_READ);
                status = apr_file_write_full(tmpfile, data, bytes_read, &bytes_written);
                if (status != APR_SUCCESS) {
                    const char *tmpfile_name;

                    if (apr_file_name_get(&tmpfile_name, tmpfile) != APR_SUCCESS) {
                        tmpfile_name = "(unknown)";
                    }
                    ap_log_error(APLOG_MARK, APLOG_ERR, status, r->server,
                                 "proxy: write to temporary file %s failed",
                                 tmpfile_name);
                    return status;
                }
                AP_DEBUG_ASSERT(bytes_read == bytes_written);
                fsize += bytes_written;
            }
            apr_brigade_cleanup(input_brigade);
        }
        else {

            /*
             * Save input_brigade in body_brigade. (At least) in the SSL case
             * input_brigade contains transient buckets whose data would get
             * overwritten during the next call of ap_get_brigade in the loop.
             * ap_save_brigade ensures these buckets to be set aside.
             * Calling ap_save_brigade with NULL as filter is OK, because
             * body_brigade already has been created and does not need to get
             * created by ap_save_brigade.
             */
            status = ap_save_brigade(NULL, &body_brigade, &input_brigade, p);
            if (status != APR_SUCCESS) {
                return status;
            }

        }

        bytes_spooled += bytes;

        if (seen_eos) {
            break;
        }

        status = ap_get_brigade(r->input_filters, input_brigade,
                                AP_MODE_READBYTES, APR_BLOCK_READ,
                                HUGE_STRING_LEN);

        if (status != APR_SUCCESS) {
            return status;
        }
    }

    if (bytes_spooled || force_cl) {
        add_cl(p, bucket_alloc, header_brigade, apr_off_t_toa(p, bytes_spooled));
    }
    terminate_headers(bucket_alloc, header_brigade);
    APR_BRIGADE_CONCAT(header_brigade, body_brigade);
    if (tmpfile) {
        /* For platforms where the size of the file may be larger than
         * that which can be stored in a single bucket (where the
         * length field is an apr_size_t), split it into several
         * buckets: */
        if (sizeof(apr_off_t) > sizeof(apr_size_t)
            && fsize > AP_MAX_SENDFILE) {
            e = apr_bucket_file_create(tmpfile, 0, AP_MAX_SENDFILE, p,
                                       bucket_alloc);
            while (fsize > AP_MAX_SENDFILE) {
                apr_bucket *ce;
                apr_bucket_copy(e, &ce);
                APR_BRIGADE_INSERT_TAIL(header_brigade, ce);
                e->start += AP_MAX_SENDFILE;
                fsize -= AP_MAX_SENDFILE;
            }
            e->length = (apr_size_t)fsize; /* Resize just the last bucket */
        }
        else {
            e = apr_bucket_file_create(tmpfile, 0, (apr_size_t)fsize, p,
                                       bucket_alloc);
        }
        APR_BRIGADE_INSERT_TAIL(header_brigade, e);
    }
    /* This is all a single brigade, pass with flush flagged */
    status = pass_brigade(bucket_alloc, r, p_conn, origin, header_brigade, 1);
    return status;
}

static
apr_status_t ap_proxy_http_request(apr_pool_t *p, request_rec *r,
                                   proxy_conn_rec *p_conn, conn_rec *origin,
                                   proxy_server_conf *conf,
                                   apr_uri_t *uri,
                                   char *url, char *server_portstr)
{
    conn_rec *c = r->connection;
    apr_bucket_alloc_t *bucket_alloc = c->bucket_alloc;
    apr_bucket_brigade *header_brigade;
    apr_bucket_brigade *input_brigade;
    apr_bucket_brigade *temp_brigade;
    apr_bucket *e;
    char *buf;
    const apr_array_header_t *headers_in_array;
    const apr_table_entry_t *headers_in;
    int counter;
    apr_status_t status;
    enum rb_methods {RB_INIT, RB_STREAM_CL, RB_STREAM_CHUNKED, RB_SPOOL_CL};
    enum rb_methods rb_method = RB_INIT;
    const char *old_cl_val = NULL;
    const char *old_te_val = NULL;
    apr_off_t bytes_read = 0;
    apr_off_t bytes;
    int force10;
    apr_table_t *headers_in_copy;

    header_brigade = apr_brigade_create(p, origin->bucket_alloc);

    /*
     * Send the HTTP/1.1 request to the remote server
     */

    if (apr_table_get(r->subprocess_env, "force-proxy-request-1.0")) {
        buf = apr_pstrcat(p, r->method, " ", url, " HTTP/1.0" CRLF, NULL);
        force10 = 1;
        p_conn->close++;
    } else {
        buf = apr_pstrcat(p, r->method, " ", url, " HTTP/1.1" CRLF, NULL);
        force10 = 0;
    }
    if (apr_table_get(r->subprocess_env, "proxy-nokeepalive")) {
        origin->keepalive = AP_CONN_CLOSE;
        p_conn->close++;
    }
    ap_xlate_proto_to_ascii(buf, strlen(buf));
    e = apr_bucket_pool_create(buf, strlen(buf), p, c->bucket_alloc);
    APR_BRIGADE_INSERT_TAIL(header_brigade, e);
    if (conf->preserve_host == 0) {
        if (uri->port_str && uri->port != DEFAULT_HTTP_PORT) {
            buf = apr_pstrcat(p, "Host: ", uri->hostname, ":", uri->port_str,
                              CRLF, NULL);
        } else {
            buf = apr_pstrcat(p, "Host: ", uri->hostname, CRLF, NULL);
        }
    }
    else {
        /* don't want to use r->hostname, as the incoming header might have a
         * port attached
         */
        const char* hostname = apr_table_get(r->headers_in,"Host");
        if (!hostname) {
            hostname =  r->server->server_hostname;
            ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r,
                          "proxy: no HTTP 0.9 request (with no host line) "
                          "on incoming request and preserve host set "
                          "forcing hostname to be %s for uri %s",
                          hostname,
                          r->uri );
        }
        buf = apr_pstrcat(p, "Host: ", hostname, CRLF, NULL);
    }
    ap_xlate_proto_to_ascii(buf, strlen(buf));
    e = apr_bucket_pool_create(buf, strlen(buf), p, c->bucket_alloc);
    APR_BRIGADE_INSERT_TAIL(header_brigade, e);

    /* handle Via */
    if (conf->viaopt == via_block) {
        /* Block all outgoing Via: headers */
        apr_table_unset(r->headers_in, "Via");
    } else if (conf->viaopt != via_off) {
        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:" request header entry and merge it */
        /* Generate outgoing Via: header with/without server comment: */
        apr_table_mergen(r->headers_in, "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)