listen.c revision da09cb78fe2e87c16e5bbe3fdea15ec9684a1be0
/* 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_network_io.h"
#include "apr_strings.h"
#define APR_WANT_STRFUNC
#include "apr_want.h"
#define CORE_PRIVATE
#include "ap_config.h"
#include "httpd.h"
#include "http_config.h"
#include "http_core.h"
#include "ap_listen.h"
#include "http_log.h"
#include "mpm.h"
#include "mpm_common.h"
AP_DECLARE_DATA ap_listen_rec *ap_listeners = NULL;
static ap_listen_rec *old_listeners;
static int ap_listenbacklog;
static int send_buffer_size;
static int receive_buffer_size;
/* TODO: make_sock is just begging and screaming for APR abstraction */
static apr_status_t make_sock(apr_pool_t *p, ap_listen_rec *server)
{
apr_socket_t *s = server->sd;
int one = 1;
#if APR_HAVE_IPV6
#ifdef AP_ENABLE_V4_MAPPED
int v6only_setting = 0;
#else
int v6only_setting = 1;
#endif
#endif
apr_status_t stat;
#ifndef WIN32
stat = apr_socket_opt_set(s, APR_SO_REUSEADDR, one);
if (stat != APR_SUCCESS && stat != APR_ENOTIMPL) {
ap_log_perror(APLOG_MARK, APLOG_CRIT, stat, p,
"make_sock: for address %pI, apr_socket_opt_set: (SO_REUSEADDR)",
server->bind_addr);
apr_socket_close(s);
return stat;
}
#endif
stat = apr_socket_opt_set(s, APR_SO_KEEPALIVE, one);
if (stat != APR_SUCCESS && stat != APR_ENOTIMPL) {
ap_log_perror(APLOG_MARK, APLOG_CRIT, stat, p,
"make_sock: for address %pI, apr_socket_opt_set: (SO_KEEPALIVE)",
server->bind_addr);
apr_socket_close(s);
return stat;
}
#if APR_HAVE_IPV6
if (server->bind_addr->family == APR_INET6) {
stat = apr_socket_opt_set(s, APR_IPV6_V6ONLY, v6only_setting);
if (stat != APR_SUCCESS && stat != APR_ENOTIMPL) {
ap_log_perror(APLOG_MARK, APLOG_CRIT, stat, p,
"make_sock: for address %pI, apr_socket_opt_set: "
"(IPV6_V6ONLY)",
server->bind_addr);
apr_socket_close(s);
return stat;
}
}
#endif
/*
* To send data over high bandwidth-delay connections at full
* speed we must force the TCP window to open wide enough to keep the
* pipe full. The default window size on many systems
* is only 4kB. Cross-country WAN connections of 100ms
* at 1Mb/s are not impossible for well connected sites.
* If we assume 100ms cross-country latency,
* a 4kB buffer limits throughput to 40kB/s.
*
* To avoid this problem I've added the SendBufferSize directive
* to allow the web master to configure send buffer size.
*
* The trade-off of larger buffers is that more kernel memory
* is consumed. YMMV, know your customers and your network!
*
* -John Heidemann <johnh@isi.edu> 25-Oct-96
*
* If no size is specified, use the kernel default.
*/
if (send_buffer_size) {
stat = apr_socket_opt_set(s, APR_SO_SNDBUF, send_buffer_size);
if (stat != APR_SUCCESS && stat != APR_ENOTIMPL) {
ap_log_perror(APLOG_MARK, APLOG_WARNING, stat, p,
"make_sock: failed to set SendBufferSize for "
"address %pI, using default",
server->bind_addr);
/* not a fatal error */
}
}
if (receive_buffer_size) {
stat = apr_socket_opt_set(s, APR_SO_RCVBUF, receive_buffer_size);
if (stat != APR_SUCCESS && stat != APR_ENOTIMPL) {
ap_log_perror(APLOG_MARK, APLOG_WARNING, stat, p,
"make_sock: failed to set ReceiveBufferSize for "
"address %pI, using default",
server->bind_addr);
/* not a fatal error */
}
}
#if APR_TCP_NODELAY_INHERITED
ap_sock_disable_nagle(s);
#endif
if ((stat = apr_socket_bind(s, server->bind_addr)) != APR_SUCCESS) {
ap_log_perror(APLOG_MARK, APLOG_STARTUP|APLOG_CRIT, stat, p,
"make_sock: could not bind to address %pI",
server->bind_addr);
apr_socket_close(s);
return stat;
}
if ((stat = apr_socket_listen(s, ap_listenbacklog)) != APR_SUCCESS) {
ap_log_perror(APLOG_MARK, APLOG_STARTUP|APLOG_ERR, stat, p,
"make_sock: unable to listen for connections "
"on address %pI",
server->bind_addr);
apr_socket_close(s);
return stat;
}
#ifdef WIN32
/* I seriously doubt that this would work on Unix; I have doubts that
* it entirely solves the problem on Win32. However, since setting
* reuseaddr on the listener -prior- to binding the socket has allowed
* us to attach to the same port as an already running instance of
* Apache, or even another web server, we cannot identify that this
* port was exclusively granted to this instance of Apache.
*
* So set reuseaddr, but do not attempt to do so until we have the
* parent listeners successfully bound.
*/
stat = apr_socket_opt_set(s, APR_SO_REUSEADDR, one);
if (stat != APR_SUCCESS && stat != APR_ENOTIMPL) {
ap_log_perror(APLOG_MARK, APLOG_CRIT, stat, p,
"make_sock: for address %pI, apr_socket_opt_set: (SO_REUSEADDR)",
server->bind_addr);
apr_socket_close(s);
return stat;
}
#endif
server->sd = s;
server->active = 1;
#ifdef MPM_ACCEPT_FUNC
server->accept_func = MPM_ACCEPT_FUNC;
#else
server->accept_func = NULL;
#endif
return APR_SUCCESS;
}
static const char* find_accf_name(server_rec *s, const char *proto)
{
const char* accf;
core_server_config *conf = ap_get_module_config(s->module_config,
&core_module);
if (!proto) {
return NULL;
}
accf = apr_table_get(conf->accf_map, proto);
if (accf && !strcmp("none", accf)) {
return NULL;
}
return accf;
}
static void ap_apply_accept_filter(apr_pool_t *p, ap_listen_rec *lis,
server_rec *server)
{
apr_socket_t *s = lis->sd;
const char *accf;
apr_status_t rv;
const char *proto;
proto = lis->protocol;
if (!proto) {
proto = ap_get_server_protocol(server);
}
accf = find_accf_name(server, proto);
if (accf) {
#if APR_HAS_SO_ACCEPTFILTER
rv = apr_socket_accept_filter(s, apr_pstrdup(p, accf),
apr_pstrdup(p,""));
if (rv != APR_SUCCESS && !APR_STATUS_IS_ENOTIMPL(rv)) {
ap_log_perror(APLOG_MARK, APLOG_WARNING, rv, p,
"Failed to enable the '%s' Accept Filter",
accf);
}
#else
#ifdef APR_TCP_DEFER_ACCEPT
rv = apr_socket_opt_set(s, APR_TCP_DEFER_ACCEPT, 1);
if (rv != APR_SUCCESS && !APR_STATUS_IS_ENOTIMPL(rv)) {
ap_log_perror(APLOG_MARK, APLOG_WARNING, rv, p,
"Failed to enable APR_TCP_DEFER_ACCEPT");
}
#endif
#endif
}
}
static apr_status_t close_listeners_on_exec(void *v)
{
ap_close_listeners();
return APR_SUCCESS;
}
static const char *alloc_listener(process_rec *process, char *addr,
apr_port_t port, const char* proto)
{
ap_listen_rec **walk, *last;
apr_status_t status;
apr_sockaddr_t *sa;
int found_listener = 0;
/* see if we've got an old listener for this address:port */
for (walk = &old_listeners; *walk;) {
sa = (*walk)->bind_addr;
/* Some listeners are not real so they will not have a bind_addr. */
if (sa) {
ap_listen_rec *new;
apr_port_t oldport;
oldport = sa->port;
/* If both ports are equivalent, then if their names are equivalent,
* then we will re-use the existing record.
*/
if (port == oldport &&
((!addr && !sa->hostname) ||
((addr && sa->hostname) && !strcmp(sa->hostname, addr)))) {
new = *walk;
*walk = new->next;
new->next = ap_listeners;
ap_listeners = new;
found_listener = 1;
continue;
}
}
walk = &(*walk)->next;
}
if (found_listener) {
return NULL;
}
if ((status = apr_sockaddr_info_get(&sa, addr, APR_UNSPEC, port, 0,
process->pool))
!= APR_SUCCESS) {
ap_log_perror(APLOG_MARK, APLOG_CRIT, status, process->pool,
"alloc_listener: failed to set up sockaddr for %s",
addr);
return "Listen setup failed";
}
/* Initialize to our last configured ap_listener. */
last = ap_listeners;
while (last && last->next) {
last = last->next;
}
while (sa) {
ap_listen_rec *new;
/* this has to survive restarts */
new = apr_palloc(process->pool, sizeof(ap_listen_rec));
new->active = 0;
new->next = 0;
new->bind_addr = sa;
new->protocol = apr_pstrdup(process->pool, proto);
/* Go to the next sockaddr. */
sa = sa->next;
status = apr_socket_create(&new->sd, new->bind_addr->family,
SOCK_STREAM, 0, process->pool);
#if APR_HAVE_IPV6
/* What could happen is that we got an IPv6 address, but this system
* doesn't actually support IPv6. Try the next address.
*/
if (status != APR_SUCCESS && !addr &&
new->bind_addr->family == APR_INET6) {
continue;
}
#endif
if (status != APR_SUCCESS) {
ap_log_perror(APLOG_MARK, APLOG_CRIT, status, process->pool,
"alloc_listener: failed to get a socket for %s",
addr);
return "Listen setup failed";
}
/* We need to preserve the order returned by getaddrinfo() */
if (last == NULL) {
ap_listeners = last = new;
} else {
last->next = new;
last = new;
}
}
return NULL;
}
/* Evaluates to true if the (apr_sockaddr_t *) addr argument is the
* IPv4 match-any-address, 0.0.0.0. */
#define IS_INADDR_ANY(addr) ((addr)->family == APR_INET \
&& (addr)->sa.sin.sin_addr.s_addr == INADDR_ANY)
/* Evaluates to true if the (apr_sockaddr_t *) addr argument is the
* IPv6 match-any-address, [::]. */
#define IS_IN6ADDR_ANY(addr) ((addr)->family == APR_INET6 \
&& IN6_IS_ADDR_UNSPECIFIED(&(addr)->sa.sin6.sin6_addr))
/**
* Create, open, listen, and bind all sockets.
* @param process The process record for the currently running server
* @return The number of open sockets
*/
static int open_listeners(apr_pool_t *pool)
{
ap_listen_rec *lr;
ap_listen_rec *next;
ap_listen_rec *previous;
int num_open;
const char *userdata_key = "ap_open_listeners";
void *data;
/* Don't allocate a default listener. If we need to listen to a
* port, then the user needs to have a Listen directive in their
* config file.
*/
num_open = 0;
previous = NULL;
for (lr = ap_listeners; lr; previous = lr, lr = lr->next) {
if (lr->active) {
++num_open;
}
else {
#if APR_HAVE_IPV6
int v6only_setting;
/* If we have the unspecified IPv4 address (0.0.0.0) and
* the unspecified IPv6 address (::) is next, we need to
* swap the order of these in the list. We always try to
* bind to IPv6 first, then IPv4, since an IPv6 socket
* might be able to receive IPv4 packets if V6ONLY is not
* enabled, but never the other way around. */
if (lr->next != NULL
&& IS_INADDR_ANY(lr->bind_addr)
&& lr->bind_addr->port == lr->next->bind_addr->port
&& IS_IN6ADDR_ANY(lr->next->bind_addr)) {
/* Exchange lr and lr->next */
next = lr->next;
lr->next = next->next;
next->next = lr;
if (previous) {
previous->next = next;
}
else {
ap_listeners = next;
}
lr = next;
}
/* If we are trying to bind to 0.0.0.0 and the previous listener
* was :: on the same port and in turn that socket does not have
* the IPV6_V6ONLY flag set; we must skip the current attempt to
* listen (which would generate an error). IPv4 will be handled
* on the established IPv6 socket.
*/
if (previous != NULL
&& IS_INADDR_ANY(lr->bind_addr)
&& lr->bind_addr->port == previous->bind_addr->port
&& IS_IN6ADDR_ANY(previous->bind_addr)
&& apr_socket_opt_get(previous->sd, APR_IPV6_V6ONLY,
&v6only_setting) == APR_SUCCESS
&& v6only_setting == 0) {
/* Remove the current listener from the list */
previous->next = lr->next;
lr = previous; /* maintain current value of previous after
* post-loop expression is evaluated
*/
continue;
}
#endif
if (make_sock(pool, lr) == APR_SUCCESS) {
++num_open;
lr->active = 1;
}
else {
#if APR_HAVE_IPV6
/* If we tried to bind to ::, and the next listener is
* on 0.0.0.0 with the same port, don't give a fatal
* error. The user will still get a warning from make_sock
* though.
*/
if (lr->next != NULL
&& IS_IN6ADDR_ANY(lr->bind_addr)
&& lr->bind_addr->port == lr->next->bind_addr->port
&& IS_INADDR_ANY(lr->next->bind_addr)) {
/* Remove the current listener from the list */
if (previous) {
previous->next = lr->next;
}
else {
ap_listeners = lr->next;
}
/* Although we've removed ourselves from the list,
* we need to make sure that the next iteration won't
* consider "previous" a working IPv6 '::' socket.
* Changing the family is enough to make sure the
* conditions before make_sock() fail.
*/
lr->bind_addr->family = AF_INET;
continue;
}
#endif
/* fatal error */
return -1;
}
}
}
/* close the old listeners */
for (lr = old_listeners; lr; lr = next) {
apr_socket_close(lr->sd);
lr->active = 0;
next = lr->next;
}
old_listeners = NULL;
#if AP_NONBLOCK_WHEN_MULTI_LISTEN
/* if multiple listening sockets, make them non-blocking so that
* if select()/poll() reports readability for a reset connection that
* is already forgotten about by the time we call accept, we won't
* be hung until another connection arrives on that port
*/
if (ap_listeners && ap_listeners->next) {
for (lr = ap_listeners; lr; lr = lr->next) {
apr_status_t status;
status = apr_socket_opt_set(lr->sd, APR_SO_NONBLOCK, 1);
if (status != APR_SUCCESS) {
ap_log_perror(APLOG_MARK, APLOG_STARTUP|APLOG_ERR, status, pool,
"unable to make listening socket non-blocking");
return -1;
}
}
}
#endif /* AP_NONBLOCK_WHEN_MULTI_LISTEN */
/* we come through here on both passes of the open logs phase
* only register the cleanup once... otherwise we try to close
* listening sockets twice when cleaning up prior to exec
*/
apr_pool_userdata_get(&data, userdata_key, pool);
if (!data) {
apr_pool_userdata_set((const void *)1, userdata_key,
apr_pool_cleanup_null, pool);
apr_pool_cleanup_register(pool, NULL, apr_pool_cleanup_null,
close_listeners_on_exec);
}
return num_open ? 0 : -1;
}
AP_DECLARE(int) ap_setup_listeners(server_rec *s)
{
server_rec *ls;
server_addr_rec *addr;
ap_listen_rec *lr;
int num_listeners = 0;
const char* proto;
int found;
for (ls = s; ls; ls = ls->next) {
proto = ap_get_server_protocol(ls);
if (!proto) {
found = 0;
/* No protocol was set for this vhost,
* use the default for this listener.
*/
for (addr = ls->addrs; addr && !found; addr = addr->next) {
for (lr = ap_listeners; lr; lr = lr->next) {
if (apr_sockaddr_equal(lr->bind_addr, addr->host_addr) &&
lr->bind_addr->port == addr->host_port) {
ap_set_server_protocol(ls, lr->protocol);
found = 1;
break;
}
}
}
if (!found) {
/* TODO: set protocol defaults per-Port, eg 25=smtp */
ap_set_server_protocol(ls, "http");
}
}
}
if (open_listeners(s->process->pool)) {
return 0;
}
for (lr = ap_listeners; lr; lr = lr->next) {
num_listeners++;
found = 0;
for (ls = s; ls && !found; ls = ls->next) {
for (addr = ls->addrs; addr && !found; addr = addr->next) {
if (apr_sockaddr_equal(lr->bind_addr, addr->host_addr) &&
lr->bind_addr->port == addr->host_port) {
found = 1;
ap_apply_accept_filter(s->process->pool, lr, ls);
}
}
}
if (!found) {
ap_apply_accept_filter(s->process->pool, lr, s);
}
}
return num_listeners;
}
AP_DECLARE_NONSTD(void) ap_close_listeners(void)
{
ap_listen_rec *lr;
for (lr = ap_listeners; lr; lr = lr->next) {
apr_socket_close(lr->sd);
lr->active = 0;
}
}
AP_DECLARE(void) ap_listen_pre_config(void)
{
old_listeners = ap_listeners;
ap_listeners = NULL;
ap_listenbacklog = DEFAULT_LISTENBACKLOG;
}
AP_DECLARE_NONSTD(const char *) ap_set_listener(cmd_parms *cmd, void *dummy,
int argc, char *const argv[])
{
char *host, *scope_id, *proto;
apr_port_t port;
apr_status_t rv;
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
if (argc < 1 || argc > 2) {
return "Listen requires 1 or 2 arguments.";
}
rv = apr_parse_addr_port(&host, &scope_id, &port, argv[0], cmd->pool);
if (rv != APR_SUCCESS) {
return "Invalid address or port";
}
if (host && !strcmp(host, "*")) {
host = NULL;
}
if (scope_id) {
/* XXX scope id support is useful with link-local IPv6 addresses */
return "Scope id is not supported";
}
if (!port) {
return "Port must be specified";
}
if (argc != 2) {
proto = "http";
}
else {
proto = apr_pstrdup(cmd->pool, argv[1]);
ap_str_tolower(proto);
}
return alloc_listener(cmd->server->process, host, port, proto);
}
AP_DECLARE_NONSTD(const char *) ap_set_listenbacklog(cmd_parms *cmd,
void *dummy,
const char *arg)
{
int b;
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
b = atoi(arg);
if (b < 1) {
return "ListenBacklog must be > 0";
}
ap_listenbacklog = b;
return NULL;
}
AP_DECLARE_NONSTD(const char *) ap_set_send_buffer_size(cmd_parms *cmd,
void *dummy,
const char *arg)
{
int s = atoi(arg);
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
if (s < 512 && s != 0) {
return "SendBufferSize must be >= 512 bytes, or 0 for system default.";
}
send_buffer_size = s;
return NULL;
}
AP_DECLARE_NONSTD(const char *) ap_set_receive_buffer_size(cmd_parms *cmd,
void *dummy,
const char *arg)
{
int s = atoi(arg);
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
if (s < 512 && s != 0) {
return "ReceiveBufferSize must be >= 512 bytes, or 0 for system default.";
}
receive_buffer_size = s;
return NULL;
}