mpm_common.c revision 7184de27ec1d62a83c41cdeac0953ca9fd661e8c
/* 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.
*/
/* The purpose of this file is to store the code that MOST mpm's will need
* this does not mean a function only goes into this file if every MPM needs
* it. It means that if a function is needed by more than one MPM, and
* future maintenance would be served by making the code common, then the
* function belongs here.
*
* This is going in src/main because it is not platform specific, it is
* specific to multi-process servers, but NOT to Unix. Which is why it
* does not belong in src/os/unix
*/
#include "apr.h"
#include "apr_thread_proc.h"
#include "apr_signal.h"
#include "apr_strings.h"
#define APR_WANT_STRFUNC
#include "apr_want.h"
#include "apr_getopt.h"
#include "apr_optional.h"
#include "apr_allocator.h"
#include "httpd.h"
#include "http_config.h"
#include "http_core.h"
#include "http_log.h"
#include "http_main.h"
#include "mpm_common.h"
#include "ap_mpm.h"
#include "ap_listen.h"
#include "util_mutex.h"
#include "scoreboard.h"
#ifdef HAVE_PWD_H
#include <pwd.h>
#endif
#ifdef HAVE_GRP_H
#include <grp.h>
#endif
#if APR_HAVE_UNISTD_H
#include <unistd.h>
#endif
/* we know core's module_index is 0 */
#undef APLOG_MODULE_INDEX
#define APLOG_MODULE_INDEX AP_CORE_MODULE_INDEX
#if AP_ENABLE_EXCEPTION_HOOK
APR_HOOK_STRUCT(
APR_HOOK_LINK(fatal_exception)
APR_HOOK_LINK(monitor)
APR_HOOK_LINK(drop_privileges)
APR_HOOK_LINK(mpm)
APR_HOOK_LINK(mpm_query)
APR_HOOK_LINK(mpm_register_timed_callback)
APR_HOOK_LINK(mpm_get_name)
APR_HOOK_LINK(end_generation)
APR_HOOK_LINK(child_status)
)
AP_IMPLEMENT_HOOK_RUN_ALL(int, fatal_exception,
(ap_exception_info_t *ei), (ei), OK, DECLINED)
#else
APR_HOOK_STRUCT(
APR_HOOK_LINK(monitor)
APR_HOOK_LINK(drop_privileges)
APR_HOOK_LINK(mpm)
APR_HOOK_LINK(mpm_query)
APR_HOOK_LINK(mpm_register_timed_callback)
APR_HOOK_LINK(mpm_get_name)
APR_HOOK_LINK(end_generation)
APR_HOOK_LINK(child_status)
)
#endif
AP_IMPLEMENT_HOOK_RUN_ALL(int, monitor,
(apr_pool_t *p, server_rec *s), (p, s), OK, DECLINED)
AP_IMPLEMENT_HOOK_RUN_ALL(int, drop_privileges,
(apr_pool_t * pchild, server_rec * s),
(pchild, s), OK, DECLINED)
AP_IMPLEMENT_HOOK_RUN_FIRST(int, mpm,
(apr_pool_t *pconf, apr_pool_t *plog, server_rec *s),
(pconf, plog, s), DECLINED)
AP_IMPLEMENT_HOOK_RUN_FIRST(int, mpm_query,
(int query_code, int *result, apr_status_t *_rv),
(query_code, result, _rv), DECLINED)
AP_IMPLEMENT_HOOK_RUN_FIRST(apr_status_t, mpm_register_timed_callback,
(apr_time_t t, ap_mpm_callback_fn_t *cbfn, void *baton),
(t, cbfn, baton), APR_ENOTIMPL)
AP_IMPLEMENT_HOOK_VOID(end_generation,
(server_rec *s, ap_generation_t gen),
(s, gen))
AP_IMPLEMENT_HOOK_VOID(child_status,
(server_rec *s, pid_t pid, ap_generation_t gen, int slot, mpm_child_status status),
(s,pid,gen,slot,status))
/* hooks with no args are implemented last, after disabling APR hook probes */
#if defined(APR_HOOK_PROBES_ENABLED)
#undef APR_HOOK_PROBES_ENABLED
#undef APR_HOOK_PROBE_ENTRY
#define APR_HOOK_PROBE_ENTRY(ud,ns,name,args)
#undef APR_HOOK_PROBE_RETURN
#define APR_HOOK_PROBE_RETURN(ud,ns,name,rv,args)
#undef APR_HOOK_PROBE_INVOKE
#define APR_HOOK_PROBE_INVOKE(ud,ns,name,src,args)
#undef APR_HOOK_PROBE_COMPLETE
#define APR_HOOK_PROBE_COMPLETE(ud,ns,name,src,rv,args)
#undef APR_HOOK_INT_DCL_UD
#define APR_HOOK_INT_DCL_UD
#endif
AP_IMPLEMENT_HOOK_RUN_FIRST(const char *, mpm_get_name,
(void),
(), NULL)
typedef struct mpm_gen_info_t {
APR_RING_ENTRY(mpm_gen_info_t) link;
int gen; /* which gen? */
int active; /* number of active processes */
} mpm_gen_info_t;
APR_RING_HEAD(mpm_gen_info_head_t, mpm_gen_info_t);
static struct mpm_gen_info_head_t geninfo, unused_geninfo;
static int gen_head_init; /* yuck */
/* variables representing config directives implemented here */
const char *ap_pid_fname;
int ap_max_requests_per_child;
char ap_coredump_dir[MAX_STRING_LEN];
int ap_coredumpdir_configured;
int ap_graceful_shutdown_timeout;
apr_uint32_t ap_max_mem_free;
apr_size_t ap_thread_stacksize;
/* Set defaults for config directives implemented here. This is
* called from core's pre-config hook, so MPMs which need to override
* one of these should run their pre-config hook after that of core.
*/
void mpm_common_pre_config(apr_pool_t *pconf)
{
ap_pid_fname = DEFAULT_PIDLOG;
ap_max_requests_per_child = 0; /* unlimited */
apr_cpystrn(ap_coredump_dir, ap_server_root, sizeof(ap_coredump_dir));
ap_coredumpdir_configured = 0;
ap_graceful_shutdown_timeout = 0; /* unlimited */
ap_max_mem_free = APR_ALLOCATOR_MAX_FREE_UNLIMITED;
ap_thread_stacksize = 0; /* use system default */
}
/* number of calls to wait_or_timeout between writable probes */
#ifndef INTERVAL_OF_WRITABLE_PROBES
#define INTERVAL_OF_WRITABLE_PROBES 10
#endif
static int wait_or_timeout_counter;
void ap_wait_or_timeout(apr_exit_why_e *status, int *exitcode, apr_proc_t *ret,
apr_pool_t *p, server_rec *s)
{
apr_status_t rv;
++wait_or_timeout_counter;
if (wait_or_timeout_counter == INTERVAL_OF_WRITABLE_PROBES) {
wait_or_timeout_counter = 0;
ap_run_monitor(p, s);
}
rv = apr_proc_wait_all_procs(ret, exitcode, status, APR_NOWAIT, p);
if (APR_STATUS_IS_EINTR(rv)) {
ret->pid = -1;
return;
}
if (APR_STATUS_IS_CHILD_DONE(rv)) {
return;
}
apr_sleep(apr_time_from_sec(1));
ret->pid = -1;
return;
}
#if defined(TCP_NODELAY)
void ap_sock_disable_nagle(apr_socket_t *s)
{
/* The Nagle algorithm says that we should delay sending partial
* packets in hopes of getting more data. We don't want to do
* this; we are not telnet. There are bad interactions between
* persistent connections and Nagle's algorithm that have very severe
* performance penalties. (Failing to disable Nagle is not much of a
* problem with simple HTTP.)
*
* In spite of these problems, failure here is not a shooting offense.
*/
apr_status_t status = apr_socket_opt_set(s, APR_TCP_NODELAY, 1);
if (status != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_WARNING, status, ap_server_conf,
"apr_socket_opt_set: (TCP_NODELAY)");
}
}
#endif
#ifdef HAVE_GETPWNAM
AP_DECLARE(uid_t) ap_uname2id(const char *name)
{
struct passwd *ent;
if (name[0] == '#')
return (atoi(&name[1]));
if (!(ent = getpwnam(name))) {
ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
"%s: bad user name %s", ap_server_argv0, name);
exit(1);
}
return (ent->pw_uid);
}
#endif
#ifdef HAVE_GETGRNAM
AP_DECLARE(gid_t) ap_gname2id(const char *name)
{
struct group *ent;
if (name[0] == '#')
return (atoi(&name[1]));
if (!(ent = getgrnam(name))) {
ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
"%s: bad group name %s", ap_server_argv0, name);
exit(1);
}
return (ent->gr_gid);
}
#endif
#ifndef HAVE_INITGROUPS
int initgroups(const char *name, gid_t basegid)
{
#if defined(_OSD_POSIX) || defined(OS2) || defined(WIN32) || defined(NETWARE)
return 0;
#else
gid_t groups[NGROUPS_MAX];
struct group *g;
int index = 0;
setgrent();
groups[index++] = basegid;
while (index < NGROUPS_MAX && ((g = getgrent()) != NULL)) {
if (g->gr_gid != basegid) {
char **names;
for (names = g->gr_mem; *names != NULL; ++names) {
if (!strcmp(*names, name))
groups[index++] = g->gr_gid;
}
}
}
endgrent();
return setgroups(index, groups);
#endif
}
#endif /* def HAVE_INITGROUPS */
/* standard mpm configuration handling */
const char *ap_mpm_set_pidfile(cmd_parms *cmd, void *dummy,
const char *arg)
{
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
if (cmd->server->is_virtual) {
return "PidFile directive not allowed in <VirtualHost>";
}
ap_pid_fname = arg;
return NULL;
}
const char *ap_mpm_set_max_requests(cmd_parms *cmd, void *dummy,
const char *arg)
{
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
if (!strcasecmp(cmd->cmd->name, "MaxRequestsPerChild")) {
ap_log_error(APLOG_MARK, APLOG_WARNING, 0, NULL,
"MaxRequestsPerChild is deprecated, use "
"MaxConnectionsPerChild instead.");
}
ap_max_requests_per_child = atoi(arg);
return NULL;
}
const char *ap_mpm_set_coredumpdir(cmd_parms *cmd, void *dummy,
const char *arg)
{
apr_finfo_t finfo;
const char *fname;
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
fname = ap_server_root_relative(cmd->pool, arg);
if (!fname) {
return apr_pstrcat(cmd->pool, "Invalid CoreDumpDirectory path ",
arg, NULL);
}
if (apr_stat(&finfo, fname, APR_FINFO_TYPE, cmd->pool) != APR_SUCCESS) {
return apr_pstrcat(cmd->pool, "CoreDumpDirectory ", fname,
" does not exist", NULL);
}
if (finfo.filetype != APR_DIR) {
return apr_pstrcat(cmd->pool, "CoreDumpDirectory ", fname,
" is not a directory", NULL);
}
apr_cpystrn(ap_coredump_dir, fname, sizeof(ap_coredump_dir));
ap_coredumpdir_configured = 1;
return NULL;
}
const char * ap_mpm_set_graceful_shutdown(cmd_parms *cmd, void *dummy,
const char *arg)
{
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
ap_graceful_shutdown_timeout = atoi(arg);
return NULL;
}
const char *ap_mpm_set_max_mem_free(cmd_parms *cmd, void *dummy,
const char *arg)
{
long value;
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
value = strtol(arg, NULL, 0);
if (value < 0 || errno == ERANGE)
return apr_pstrcat(cmd->pool, "Invalid MaxMemFree value: ",
arg, NULL);
ap_max_mem_free = (apr_uint32_t)value * 1024;
return NULL;
}
const char *ap_mpm_set_thread_stacksize(cmd_parms *cmd, void *dummy,
const char *arg)
{
long value;
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
value = strtol(arg, NULL, 0);
if (value < 0 || errno == ERANGE)
return apr_pstrcat(cmd->pool, "Invalid ThreadStackSize value: ",
arg, NULL);
ap_thread_stacksize = (apr_size_t)value;
return NULL;
}
AP_DECLARE(apr_status_t) ap_mpm_query(int query_code, int *result)
{
apr_status_t rv;
if (ap_run_mpm_query(query_code, result, &rv) == DECLINED) {
rv = APR_EGENERAL;
}
return rv;
}
/* core's child-status hook
* tracks number of remaining children per generation and
* runs the end-generation hook when a generation finishes
*/
void ap_core_child_status(server_rec *s, pid_t pid,
ap_generation_t gen, int slot,
mpm_child_status status)
{
mpm_gen_info_t *cur;
const char *status_msg = "unknown status";
if (!gen_head_init) { /* where to run this? */
gen_head_init = 1;
APR_RING_INIT(&geninfo, mpm_gen_info_t, link);
APR_RING_INIT(&unused_geninfo, mpm_gen_info_t, link);
}
cur = APR_RING_FIRST(&geninfo);
while (cur != APR_RING_SENTINEL(&geninfo, mpm_gen_info_t, link) &&
cur->gen != gen) {
cur = APR_RING_NEXT(cur, link);
}
switch(status) {
case MPM_CHILD_STARTED:
status_msg = "started";
if (cur == APR_RING_SENTINEL(&geninfo, mpm_gen_info_t, link)) {
/* first child for this generation */
if (!APR_RING_EMPTY(&unused_geninfo, mpm_gen_info_t, link)) {
cur = APR_RING_FIRST(&unused_geninfo);
APR_RING_REMOVE(cur, link);
}
else {
cur = apr_pcalloc(s->process->pool, sizeof *cur);
}
cur->gen = gen;
APR_RING_ELEM_INIT(cur, link);
APR_RING_INSERT_HEAD(&geninfo, cur, mpm_gen_info_t, link);
}
++cur->active;
break;
case MPM_CHILD_EXITED:
status_msg = "exited";
if (cur == APR_RING_SENTINEL(&geninfo, mpm_gen_info_t, link)) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, s,
"no record of generation %d of exiting child %" APR_PID_T_FMT,
gen, pid);
}
else {
--cur->active;
if (!cur->active) {
ap_log_error(APLOG_MARK, APLOG_TRACE4, 0, ap_server_conf,
"end of generation %d", gen);
ap_run_end_generation(ap_server_conf, gen);
APR_RING_REMOVE(cur, link);
APR_RING_INSERT_HEAD(&unused_geninfo, cur, mpm_gen_info_t, link);
}
}
break;
case MPM_CHILD_LOST_SLOT:
status_msg = "lost slot";
/* we don't track by slot, so it doesn't matter */
break;
}
ap_log_error(APLOG_MARK, APLOG_TRACE4, 0, s,
"mpm child %" APR_PID_T_FMT " (gen %d/slot %d) %s",
pid, gen, slot, status_msg);
}
AP_DECLARE(apr_status_t) ap_mpm_register_timed_callback(apr_time_t t, ap_mpm_callback_fn_t *cbfn, void *baton)
{
return ap_run_mpm_register_timed_callback(t, cbfn, baton);
}
AP_DECLARE(const char *)ap_show_mpm(void)
{
const char *name = ap_run_mpm_get_name();
if (!name) {
name = "";
}
return name;
}
AP_DECLARE(const char *)ap_check_mpm(void)
{
static const char *last_mpm_name = NULL;
if (!_hooks.link_mpm || _hooks.link_mpm->nelts == 0)
return "No MPM loaded.";
else if (_hooks.link_mpm->nelts > 1)
return "More than one MPM loaded.";
if (last_mpm_name) {
if (strcmp(last_mpm_name, ap_show_mpm())) {
return "The MPM cannot be changed during restart.";
}
}
else {
last_mpm_name = apr_pstrdup(ap_pglobal, ap_show_mpm());
}
return NULL;
}