1 /* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements. See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License. You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
18 #include "apr_strings.h"
20 #include "ap_config.h"
22 #include "http_connection.h"
23 #include "http_request.h"
24 #include "http_protocol.h"
26 #include "http_config.h"
27 #include "http_core.h"
28 #include "http_vhost.h"
29 #include "scoreboard.h"
31 #include "util_filter.h"
34 APR_HOOK_LINK(create_connection)
35 APR_HOOK_LINK(process_connection)
36 APR_HOOK_LINK(pre_connection)
37 APR_HOOK_LINK(pre_close_connection)
39 AP_IMPLEMENT_HOOK_RUN_FIRST(conn_rec *,create_connection,
40 (apr_pool_t *p, server_rec *server, apr_socket_t *csd, long conn_id, void *sbh, apr_bucket_alloc_t *alloc),
41 (p, server, csd, conn_id, sbh, alloc), NULL)
42 AP_IMPLEMENT_HOOK_RUN_FIRST(int,process_connection,(conn_rec *c),(c),DECLINED)
43 AP_IMPLEMENT_HOOK_RUN_ALL(int,pre_connection,(conn_rec *c, void *csd),(c, csd),OK,DECLINED)
44 AP_IMPLEMENT_HOOK_RUN_ALL(int,pre_close_connection,(conn_rec *c),(c),OK,DECLINED)
47 * More machine-dependent networking gooo... on some systems,
48 * you've got to be *really* sure that all the packets are acknowledged
49 * before closing the connection, since the client will not be able
50 * to see the last response if their TCP buffer is flushed by a RST
51 * packet from us, which is what the server's TCP stack will send
52 * if it receives any request data after closing the connection.
54 * In an ideal world, this function would be accomplished by simply
55 * setting the socket option SO_LINGER and handling it within the
56 * server's TCP stack while the process continues on to the next request.
57 * Unfortunately, it seems that most (if not all) operating systems
58 * block the server process on close() when SO_LINGER is used.
59 * For those that don't, see USE_SO_LINGER below. For the rest,
60 * we have created a home-brew lingering_close.
62 * Many operating systems tend to block, puke, or otherwise mishandle
63 * calls to shutdown only half of the connection. You should define
64 * NO_LINGCLOSE in ap_config.h if such is the case for your system.
66 #ifndef MAX_SECS_TO_LINGER
67 #define MAX_SECS_TO_LINGER 30
70 AP_CORE_DECLARE(apr_status_t) ap_shutdown_conn(conn_rec *c, int flush)
73 apr_bucket_brigade *bb;
76 bb = apr_brigade_create(c->pool, c->bucket_alloc);
80 b = apr_bucket_flush_create(c->bucket_alloc);
81 APR_BRIGADE_INSERT_TAIL(bb, b);
84 /* End Of Connection bucket */
85 b = ap_bucket_eoc_create(c->bucket_alloc);
86 APR_BRIGADE_INSERT_TAIL(bb, b);
88 rv = ap_pass_brigade(c->output_filters, bb);
89 apr_brigade_destroy(bb);
93 AP_CORE_DECLARE(void) ap_flush_conn(conn_rec *c)
95 (void)ap_shutdown_conn(c, 1);
98 AP_DECLARE(int) ap_prep_lingering_close(conn_rec *c)
100 /* Give protocol handlers one last chance to raise their voice */
101 ap_run_pre_close_connection(c);
104 ap_update_child_status(c->sbh, SERVER_CLOSING, NULL);
109 /* we now proceed to read from the client until we get EOF, or until
110 * MAX_SECS_TO_LINGER has passed. The reasons for doing this are
111 * documented in a draft:
113 * http://tools.ietf.org/html/draft-ietf-http-connection-00.txt
115 * in a nutshell -- if we don't make this effort we risk causing
116 * TCP RST packets to be sent which can tear down a connection before
117 * all the response data has been sent to the client.
119 #define SECONDS_TO_LINGER 2
121 AP_DECLARE(int) ap_start_lingering_close(conn_rec *c)
123 apr_socket_t *csd = ap_get_conn_socket(c);
129 if (ap_prep_lingering_close(c)) {
133 /* Close the connection, being careful to send out whatever is still
134 * in our buffers. If possible, try to avoid a hard close until the
135 * client has ACKed our FIN and/or has stopped sending us data.
138 /* Send any leftover data to the client, but never try to again */
142 apr_socket_close(csd);
145 /* Shut down the socket for write, which will send a FIN
149 || apr_socket_shutdown(csd, APR_SHUTDOWN_WRITE) != APR_SUCCESS) {
150 apr_socket_close(csd);
157 AP_DECLARE(void) ap_lingering_close(conn_rec *c)
161 apr_time_t now, timeup = 0;
162 apr_socket_t *csd = ap_get_conn_socket(c);
164 if (ap_start_lingering_close(c)) {
168 /* Read available data from the client whilst it continues sending
169 * it, for a maximum time of MAX_SECS_TO_LINGER. If the client
170 * does not send any data within 2 seconds (a value pulled from
171 * Apache 1.3 which seems to work well), give up.
173 apr_socket_timeout_set(csd, apr_time_from_sec(SECONDS_TO_LINGER));
174 apr_socket_opt_set(csd, APR_INCOMPLETE_READ, 1);
176 /* The common path here is that the initial apr_socket_recv() call
177 * will return 0 bytes read; so that case must avoid the expensive
178 * apr_time_now() call and time arithmetic. */
181 nbytes = sizeof(dummybuf);
182 if (apr_socket_recv(csd, dummybuf, &nbytes) || nbytes == 0)
185 now = apr_time_now();
188 * First time through;
189 * calculate now + 30 seconds (MAX_SECS_TO_LINGER).
191 * If some module requested a shortened waiting period, only wait for
192 * 2s (SECONDS_TO_LINGER). This is useful for mitigating certain
195 if (apr_table_get(c->notes, "short-lingering-close")) {
196 timeup = now + apr_time_from_sec(SECONDS_TO_LINGER);
199 timeup = now + apr_time_from_sec(MAX_SECS_TO_LINGER);
203 } while (now < timeup);
205 apr_socket_close(csd);
208 AP_CORE_DECLARE(void) ap_process_connection(conn_rec *c, void *csd)
211 ap_update_vhost_given_ip(c);
213 rc = ap_run_pre_connection(c, csd);
214 if (rc != OK && rc != DONE) {
219 ap_run_process_connection(c);