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+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* CONNECT method for Apache proxy */
+
+#include "mod_proxy.h"
+#include "apr_poll.h"
+
+#define CONN_BLKSZ AP_IOBUFSIZE
+
+module AP_MODULE_DECLARE_DATA proxy_connect_module;
+
+/*
+ * This handles Netscape CONNECT method secure proxy requests.
+ * A connection is opened to the specified host and data is
+ * passed through between the WWW site and the browser.
+ *
+ * This code is based on the INTERNET-DRAFT document
+ * "Tunneling SSL Through a WWW Proxy" currently at
+ * http://www.mcom.com/newsref/std/tunneling_ssl.html.
+ *
+ * If proxyhost and proxyport are set, we send a CONNECT to
+ * the specified proxy..
+ *
+ * FIXME: this doesn't log the number of bytes sent, but
+ * that may be okay, since the data is supposed to
+ * be transparent. In fact, this doesn't log at all
+ * yet. 8^)
+ * FIXME: doesn't check any headers initially sent from the
+ * client.
+ * FIXME: should allow authentication, but hopefully the
+ * generic proxy authentication is good enough.
+ * FIXME: no check for r->assbackwards, whatever that is.
+ */
+
+typedef struct {
+ apr_array_header_t *allowed_connect_ports;
+} connect_conf;
+
+typedef struct {
+ int first;
+ int last;
+} port_range;
+
+static void *create_config(apr_pool_t *p, server_rec *s)
+{
+ connect_conf *c = apr_pcalloc(p, sizeof(connect_conf));
+ c->allowed_connect_ports = apr_array_make(p, 10, sizeof(port_range));
+ return c;
+}
+
+static void *merge_config(apr_pool_t *p, void *basev, void *overridesv)
+{
+ connect_conf *c = apr_pcalloc(p, sizeof(connect_conf));
+ connect_conf *base = (connect_conf *) basev;
+ connect_conf *overrides = (connect_conf *) overridesv;
+
+ c->allowed_connect_ports = apr_array_append(p,
+ base->allowed_connect_ports,
+ overrides->allowed_connect_ports);
+
+ return c;
+}
+
+
+/*
+ * Set the ports CONNECT can use
+ */
+static const char *
+ set_allowed_ports(cmd_parms *parms, void *dummy, const char *arg)
+{
+ server_rec *s = parms->server;
+ int first, last;
+ connect_conf *conf =
+ ap_get_module_config(s->module_config, &proxy_connect_module);
+ port_range *New;
+ char *endptr;
+ const char *p = arg;
+
+ if (!apr_isdigit(arg[0]))
+ return "AllowCONNECT: port numbers must be numeric";
+
+ first = strtol(p, &endptr, 10);
+ if (*endptr == '-') {
+ p = endptr + 1;
+ last = strtol(p, &endptr, 10);
+ }
+ else {
+ last = first;
+ }
+
+ if (endptr == p || *endptr != '\0') {
+ return apr_psprintf(parms->temp_pool,
+ "Cannot parse '%s' as port number", p);
+ }
+
+ New = apr_array_push(conf->allowed_connect_ports);
+ New->first = first;
+ New->last = last;
+ return NULL;
+}
+
+
+static int allowed_port(connect_conf *conf, int port)
+{
+ int i;
+ port_range *list = (port_range *) conf->allowed_connect_ports->elts;
+
+ if (apr_is_empty_array(conf->allowed_connect_ports)) {
+ return port == APR_URI_HTTPS_DEFAULT_PORT
+ || port == APR_URI_SNEWS_DEFAULT_PORT;
+ }
+
+ for (i = 0; i < conf->allowed_connect_ports->nelts; i++) {
+ if (port >= list[i].first && port <= list[i].last)
+ return 1;
+ }
+ return 0;
+}
+
+/* canonicalise CONNECT URLs. */
+static int proxy_connect_canon(request_rec *r, char *url)
+{
+
+ if (r->method_number != M_CONNECT) {
+ return DECLINED;
+ }
+ ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "canonicalising URL %s", url);
+
+ return OK;
+}
+
+/* CONNECT handler */
+static int proxy_connect_handler(request_rec *r, proxy_worker *worker,
+ proxy_server_conf *conf,
+ char *url, const char *proxyname,
+ apr_port_t proxyport)
+{
+ connect_conf *c_conf =
+ ap_get_module_config(r->server->module_config, &proxy_connect_module);
+
+ apr_pool_t *p = r->pool;
+ apr_socket_t *sock;
+ conn_rec *c = r->connection;
+ conn_rec *backconn;
+
+ apr_status_t rv;
+ apr_size_t nbytes;
+ char buffer[HUGE_STRING_LEN];
+
+ apr_bucket_brigade *bb;
+ proxy_tunnel_rec *tunnel;
+ int failed, rc;
+
+ apr_uri_t uri;
+ const char *connectname;
+ apr_port_t connectport = 0;
+ apr_sockaddr_t *nexthop;
+
+ apr_interval_time_t current_timeout;
+
+ /* is this for us? */
+ if (r->method_number != M_CONNECT) {
+ ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "declining URL %s", url);
+ return DECLINED;
+ }
+ ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "serving URL %s", url);
+
+
+ /*
+ * Step One: Determine Who To Connect To
+ *
+ * Break up the URL to determine the host to connect to
+ */
+
+ /* we break the URL into host, port, uri */
+ if (APR_SUCCESS != apr_uri_parse_hostinfo(p, url, &uri)) {
+ return ap_proxyerror(r, HTTP_BAD_REQUEST,
+ apr_pstrcat(p, "URI cannot be parsed: ", url,
+ NULL));
+ }
+
+ ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01019)
+ "connecting %s to %s:%d", url, uri.hostname, uri.port);
+
+ /* Determine host/port of next hop; from request URI or of a proxy. */
+ connectname = proxyname ? proxyname : uri.hostname;
+ connectport = proxyname ? proxyport : uri.port;
+
+ /* Do a DNS lookup for the next hop */
+ rv = apr_sockaddr_info_get(&nexthop, connectname, APR_UNSPEC,
+ connectport, 0, p);
+ if (rv != APR_SUCCESS) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(02327)
+ "failed to resolve hostname '%s'", connectname);
+ return ap_proxyerror(r, HTTP_BAD_GATEWAY,
+ apr_pstrcat(p, "DNS lookup failure for: ",
+ connectname, NULL));
+ }
+
+ /* Check ProxyBlock directive on the hostname/address. */
+ if (ap_proxy_checkproxyblock2(r, conf, uri.hostname,
+ proxyname ? NULL : nexthop) != OK) {
+ return ap_proxyerror(r, HTTP_FORBIDDEN,
+ "Connect to remote machine blocked");
+ }
+
+ ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
+ "connecting to remote proxy %s on port %d",
+ connectname, connectport);
+
+ /* Check if it is an allowed port */
+ if (!allowed_port(c_conf, uri.port)) {
+ return ap_proxyerror(r, HTTP_FORBIDDEN,
+ "Connect to remote machine blocked");
+ }
+
+ /*
+ * Step Two: Make the Connection
+ *
+ * We have determined who to connect to. Now make the connection.
+ */
+
+ /*
+ * At this point we have a list of one or more IP addresses of
+ * the machine to connect to. If configured, reorder this
+ * list so that the "best candidate" is first try. "best
+ * candidate" could mean the least loaded server, the fastest
+ * responding server, whatever.
+ *
+ * For now we do nothing, ie we get DNS round robin.
+ * XXX FIXME
+ */
+ failed = ap_proxy_connect_to_backend(&sock, "CONNECT", nexthop,
+ connectname, conf, r);
+
+ /* handle a permanent error from the above loop */
+ if (failed) {
+ if (proxyname) {
+ return DECLINED;
+ }
+ else {
+ return HTTP_SERVICE_UNAVAILABLE;
+ }
+ }
+
+ /*
+ * Step Three: Send the Request
+ *
+ * Send the HTTP/1.1 CONNECT request to the remote server
+ */
+
+ backconn = ap_run_create_connection(c->pool, r->server, sock,
+ c->id, c->sbh, c->bucket_alloc);
+ if (!backconn) {
+ /* peer reset */
+ ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(01021)
+ "an error occurred creating a new connection "
+ "to %pI (%s)", nexthop, connectname);
+ apr_socket_close(sock);
+ return HTTP_INTERNAL_SERVER_ERROR;
+ }
+ ap_proxy_ssl_engine(backconn, r->per_dir_config, 0);
+
+ /*
+ * save the timeout of the socket because core_pre_connection
+ * will set it to base_server->timeout
+ * (core TimeOut directive).
+ */
+ apr_socket_timeout_get(sock, &current_timeout);
+ rc = ap_run_pre_connection(backconn, sock);
+ if (rc != OK && rc != DONE) {
+ backconn->aborted = 1;
+ ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01022)
+ "pre_connection setup failed (%d)", rc);
+ apr_socket_close(sock);
+ return HTTP_INTERNAL_SERVER_ERROR;
+ }
+ apr_socket_timeout_set(sock, current_timeout);
+
+ ap_log_rerror(APLOG_MARK, APLOG_TRACE3, 0, r,
+ "connection complete to %pI (%s)",
+ nexthop, connectname);
+ apr_table_setn(r->notes, "proxy-source-port", apr_psprintf(r->pool, "%hu",
+ backconn->local_addr->port));
+
+ bb = apr_brigade_create(p, c->bucket_alloc);
+
+ /* If we are connecting through a remote proxy, we need to pass
+ * the CONNECT request on to it.
+ */
+ if (proxyport) {
+ /* FIXME: Error checking ignored.
+ */
+ ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r,
+ "sending the CONNECT request to the remote proxy");
+ ap_fprintf(backconn->output_filters, bb,
+ "CONNECT %s HTTP/1.0" CRLF, r->uri);
+ ap_fprintf(backconn->output_filters, bb,
+ "Proxy-agent: %s" CRLF CRLF, ap_get_server_banner());
+ ap_fflush(backconn->output_filters, bb);
+ }
+ else {
+ ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "Returning 200 OK");
+ nbytes = apr_snprintf(buffer, sizeof(buffer),
+ "HTTP/1.0 200 Connection Established" CRLF);
+ ap_xlate_proto_to_ascii(buffer, nbytes);
+ ap_fwrite(c->output_filters, bb, buffer, nbytes);
+ nbytes = apr_snprintf(buffer, sizeof(buffer),
+ "Proxy-agent: %s" CRLF CRLF,
+ ap_get_server_banner());
+ ap_xlate_proto_to_ascii(buffer, nbytes);
+ ap_fwrite(c->output_filters, bb, buffer, nbytes);
+ ap_fflush(c->output_filters, bb);
+#if 0
+ /* This is safer code, but it doesn't work yet. I'm leaving it
+ * here so that I can fix it later.
+ */
+ r->status = HTTP_OK;
+ r->header_only = 1;
+ apr_table_set(r->headers_out, "Proxy-agent: %s", ap_get_server_banner());
+ ap_rflush(r);
+#endif
+ }
+ apr_brigade_cleanup(bb);
+
+ /*
+ * Step Four: Handle Data Transfer
+ *
+ * Handle two way transfer of data over the socket (this is a tunnel).
+ */
+
+ /* r->sent_bodyct = 1; */
+
+ rv = ap_proxy_tunnel_create(&tunnel, r, backconn, "CONNECT");
+ if (rv != APR_SUCCESS) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(10208)
+ "can't create tunnel for %pI (%s)",
+ nexthop, connectname);
+ return HTTP_INTERNAL_SERVER_ERROR;
+ }
+
+ rc = ap_proxy_tunnel_run(tunnel);
+ if (ap_is_HTTP_ERROR(rc)) {
+ if (rc == HTTP_GATEWAY_TIME_OUT) {
+ /* ap_proxy_tunnel_run() didn't log this */
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(10224)
+ "tunnel timed out");
+ }
+ /* Don't send an error page if we sent data already */
+ if (proxyport && !tunnel->replied) {
+ return rc;
+ }
+ }
+
+ /*
+ * Step Five: Clean Up
+ *
+ * Close the socket and clean up
+ */
+
+ if (backconn->aborted)
+ apr_socket_close(sock);
+ else
+ ap_lingering_close(backconn);
+
+ return OK;
+}
+
+static void ap_proxy_connect_register_hook(apr_pool_t *p)
+{
+ proxy_hook_scheme_handler(proxy_connect_handler, NULL, NULL, APR_HOOK_MIDDLE);
+ proxy_hook_canon_handler(proxy_connect_canon, NULL, NULL, APR_HOOK_MIDDLE);
+}
+
+static const command_rec cmds[] =
+{
+ AP_INIT_ITERATE("AllowCONNECT", set_allowed_ports, NULL, RSRC_CONF,
+ "A list of ports or port ranges which CONNECT may connect to"),
+ {NULL}
+};
+
+AP_DECLARE_MODULE(proxy_connect) = {
+ STANDARD20_MODULE_STUFF,
+ NULL, /* create per-directory config structure */
+ NULL, /* merge per-directory config structures */
+ create_config, /* create per-server config structure */
+ merge_config, /* merge per-server config structures */
+ cmds, /* command apr_table_t */
+ ap_proxy_connect_register_hook /* register hooks */
+};
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