Adding upstream version 2.4.56.upstream/2.4.56

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 219 insertions, 0 deletions

diff --git a/server/connection.c b/server/connection.c
new file mode 100644
index 0000000..bbc94c4
--- /dev/null
+++ b/server/connection.c
@@ -0,0 +1,219 @@
+/* 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.
+ */
+
+#include "apr.h"
+#include "apr_strings.h"
+
+#include "ap_config.h"
+#include "httpd.h"
+#include "http_connection.h"
+#include "http_request.h"
+#include "http_protocol.h"
+#include "ap_mpm.h"
+#include "http_config.h"
+#include "http_core.h"
+#include "http_vhost.h"
+#include "scoreboard.h"
+#include "http_log.h"
+#include "util_filter.h"
+
+APR_HOOK_STRUCT(
+            APR_HOOK_LINK(create_connection)
+            APR_HOOK_LINK(process_connection)
+            APR_HOOK_LINK(pre_connection)
+            APR_HOOK_LINK(pre_close_connection)
+)
+AP_IMPLEMENT_HOOK_RUN_FIRST(conn_rec *,create_connection,
+                            (apr_pool_t *p, server_rec *server, apr_socket_t *csd, long conn_id, void *sbh, apr_bucket_alloc_t *alloc),
+                            (p, server, csd, conn_id, sbh, alloc), NULL)
+AP_IMPLEMENT_HOOK_RUN_FIRST(int,process_connection,(conn_rec *c),(c),DECLINED)
+AP_IMPLEMENT_HOOK_RUN_ALL(int,pre_connection,(conn_rec *c, void *csd),(c, csd),OK,DECLINED)
+AP_IMPLEMENT_HOOK_RUN_ALL(int,pre_close_connection,(conn_rec *c),(c),OK,DECLINED)
+
+/*
+ * More machine-dependent networking gooo... on some systems,
+ * you've got to be *really* sure that all the packets are acknowledged
+ * before closing the connection, since the client will not be able
+ * to see the last response if their TCP buffer is flushed by a RST
+ * packet from us, which is what the server's TCP stack will send
+ * if it receives any request data after closing the connection.
+ *
+ * In an ideal world, this function would be accomplished by simply
+ * setting the socket option SO_LINGER and handling it within the
+ * server's TCP stack while the process continues on to the next request.
+ * Unfortunately, it seems that most (if not all) operating systems
+ * block the server process on close() when SO_LINGER is used.
+ * For those that don't, see USE_SO_LINGER below.  For the rest,
+ * we have created a home-brew lingering_close.
+ *
+ * Many operating systems tend to block, puke, or otherwise mishandle
+ * calls to shutdown only half of the connection.  You should define
+ * NO_LINGCLOSE in ap_config.h if such is the case for your system.
+ */
+#ifndef MAX_SECS_TO_LINGER
+#define MAX_SECS_TO_LINGER 30
+#endif
+
+AP_CORE_DECLARE(apr_status_t) ap_shutdown_conn(conn_rec *c, int flush)
+{
+    apr_status_t rv;
+    apr_bucket_brigade *bb;
+    apr_bucket *b;
+
+    bb = apr_brigade_create(c->pool, c->bucket_alloc);
+
+    if (flush) {
+        /* FLUSH bucket */
+        b = apr_bucket_flush_create(c->bucket_alloc);
+        APR_BRIGADE_INSERT_TAIL(bb, b);
+    }
+
+    /* End Of Connection bucket */
+    b = ap_bucket_eoc_create(c->bucket_alloc);
+    APR_BRIGADE_INSERT_TAIL(bb, b);
+
+    rv = ap_pass_brigade(c->output_filters, bb);
+    apr_brigade_destroy(bb);
+    return rv;
+}
+
+AP_CORE_DECLARE(void) ap_flush_conn(conn_rec *c)
+{
+    (void)ap_shutdown_conn(c, 1);
+}
+
+AP_DECLARE(int) ap_prep_lingering_close(conn_rec *c)
+{
+    /* Give protocol handlers one last chance to raise their voice */
+    ap_run_pre_close_connection(c);
+    
+    if (c->sbh) {
+        ap_update_child_status(c->sbh, SERVER_CLOSING, NULL);
+    }
+    return 0;
+}
+
+/* we now proceed to read from the client until we get EOF, or until
+ * MAX_SECS_TO_LINGER has passed.  The reasons for doing this are
+ * documented in a draft:
+ *
+ * http://tools.ietf.org/html/draft-ietf-http-connection-00.txt
+ *
+ * in a nutshell -- if we don't make this effort we risk causing
+ * TCP RST packets to be sent which can tear down a connection before
+ * all the response data has been sent to the client.
+ */
+#define SECONDS_TO_LINGER  2
+
+AP_DECLARE(int) ap_start_lingering_close(conn_rec *c)
+{
+    apr_socket_t *csd = ap_get_conn_socket(c);
+
+    ap_assert(csd != NULL);
+
+    if (ap_prep_lingering_close(c)) {
+        return 1;
+    }
+    
+    /* Close the connection, being careful to send out whatever is still
+     * in our buffers.  If possible, try to avoid a hard close until the
+     * client has ACKed our FIN and/or has stopped sending us data.
+     */
+
+    /* Send any leftover data to the client, but never try to again */
+    ap_flush_conn(c);
+
+#ifdef NO_LINGCLOSE
+    return 1;
+#else
+    /* Shut down the socket for write, which will send a FIN
+     * to the peer.
+     */
+    return (c->aborted || apr_socket_shutdown(csd, APR_SHUTDOWN_WRITE));
+#endif
+}
+
+AP_DECLARE(void) ap_lingering_close(conn_rec *c)
+{
+    char dummybuf[512];
+    apr_size_t nbytes;
+    apr_time_t now, timeup = 0;
+    apr_socket_t *csd = ap_get_conn_socket(c);
+
+    if (!csd) {
+        /* Be safe with third-party modules that:
+         *   ap_set_core_module_config(c->conn_config, NULL)
+         * to no-op ap_lingering_close().
+         */
+        c->aborted = 1;
+        return;
+    }
+
+    if (ap_start_lingering_close(c)) {
+        apr_socket_close(csd);
+        return;
+    }
+
+    /* Read available data from the client whilst it continues sending
+     * it, for a maximum time of MAX_SECS_TO_LINGER.  If the client
+     * does not send any data within 2 seconds (a value pulled from
+     * Apache 1.3 which seems to work well), give up.
+     */
+    apr_socket_timeout_set(csd, apr_time_from_sec(SECONDS_TO_LINGER));
+    apr_socket_opt_set(csd, APR_INCOMPLETE_READ, 1);
+
+    /* The common path here is that the initial apr_socket_recv() call
+     * will return 0 bytes read; so that case must avoid the expensive
+     * apr_time_now() call and time arithmetic. */
+
+    do {
+        nbytes = sizeof(dummybuf);
+        if (apr_socket_recv(csd, dummybuf, &nbytes) || nbytes == 0)
+            break;
+
+        now = apr_time_now();
+        if (timeup == 0) {
+            /*
+             * First time through;
+             * calculate now + 30 seconds (MAX_SECS_TO_LINGER).
+             *
+             * If some module requested a shortened waiting period, only wait for
+             * 2s (SECONDS_TO_LINGER). This is useful for mitigating certain
+             * DoS attacks.
+             */
+            if (apr_table_get(c->notes, "short-lingering-close")) {
+                timeup = now + apr_time_from_sec(SECONDS_TO_LINGER);
+            }
+            else {
+                timeup = now + apr_time_from_sec(MAX_SECS_TO_LINGER);
+            }
+            continue;
+        }
+    } while (now < timeup);
+
+    apr_socket_close(csd);
+}
+
+AP_CORE_DECLARE(void) ap_process_connection(conn_rec *c, void *csd)
+{
+    ap_update_vhost_given_ip(c);
+
+    ap_pre_connection(c, csd);
+
+    if (!c->aborted) {
+        ap_run_process_connection(c);
+    }
+}