perchild.c revision 612b906e8dd17ebb1704b6663caf5d9ab321f971
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000-2001 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
* Portions of this software are based upon public domain software
* originally written at the National Center for Supercomputing Applications,
* University of Illinois, Urbana-Champaign.
*/
#include "apr_hash.h"
#include "apr_strings.h"
#include "apr_pools.h"
#include "apr_portable.h"
#include "apr_file_io.h"
#include "apr_signal.h"
#define APR_WANT_IOVEC
#include "apr_want.h"
#if APR_HAVE_UNISTD_H
#include <unistd.h>
#endif
#if APR_HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#if !APR_HAS_THREADS
#error The perchild MPM requires APR threads, but they are unavailable.
#endif
#define CORE_PRIVATE
#include "ap_config.h"
#include "httpd.h"
#include "http_main.h"
#include "http_log.h"
#include "http_config.h" /* for read_config */
#include "http_core.h" /* for get_remote_host */
#include "http_protocol.h"
#include "http_connection.h"
#include "ap_mpm.h"
#include "unixd.h"
#include "mpm_common.h"
#include "ap_listen.h"
#include "mpm_default.h"
#include "mpm.h"
#include "scoreboard.h"
#include "util_filter.h"
/* ### should be APR-ized */
#include <poll.h>
#include <grp.h>
#include <pwd.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <setjmp.h>
#ifdef HAVE_SYS_PROCESSOR_H
#include <sys/processor.h> /* for bindprocessor() */
#endif
/*
* Define some magic numbers that we use for the state of the incomming
* request. These must be < 0 so they don't collide with a file descriptor.
*/
#define AP_PERCHILD_THISCHILD -1
#define AP_PERCHILD_OTHERCHILD -2
/* Limit on the threads per process. Clients will be locked out if more than
* this * server_limit are needed.
*
* We keep this for one reason it keeps the size of the scoreboard file small
* enough that we can read the whole thing without worrying too much about
* the overhead.
*/
#ifndef DEFAULT_THREAD_LIMIT
#define DEFAULT_THREAD_LIMIT 64
#endif
/* Admin can't tune ThreadLimit beyond MAX_THREAD_LIMIT. We want
* some sort of compile-time limit to help catch typos.
*/
#ifndef MAX_THREAD_LIMIT
#define MAX_THREAD_LIMIT 20000
#endif
/* Limit on the total --- clients will be locked out if more servers than
* this are needed. It is intended solely to keep the server from crashing
* when things get out of hand.
*
* We keep a hard maximum number of servers, for two reasons --- first off,
* in case something goes seriously wrong, we want to stop the fork bomb
* short of actually crashing the machine we're running on by filling some
* kernel table. Secondly, it keeps the size of the scoreboard file small
* enough that we can read the whole thing without worrying too much about
* the overhead.
*/
#ifndef DEFAULT_SERVER_LIMIT
#define DEFAULT_SERVER_LIMIT 8
#endif
/* Admin can't tune ServerLimit beyond MAX_SERVER_LIMIT. We want
* some sort of compile-time limit to help catch typos.
*/
#ifndef MAX_SERVER_LIMIT
#define MAX_SERVER_LIMIT 20000
#endif
/*
* Actual definitions of config globals
*/
static int threads_to_start = 0; /* Worker threads per child */
static int min_spare_threads = 0;
static int max_spare_threads = 0;
static int max_threads = 0;
static int server_limit = DEFAULT_SERVER_LIMIT;
static int first_server_limit;
static int thread_limit = DEFAULT_THREAD_LIMIT;
static int first_thread_limit;
static int changed_limit_at_restart;
static int max_requests_per_child = 0;
static int num_daemons = 0;
static int curr_child_num = 0;
static int workers_may_exit = 0;
static int requests_this_child;
static int num_listenfds = 0;
static apr_socket_t **listenfds;
static jmp_buf jmpbuffer;
struct child_info_t {
uid_t uid;
gid_t gid;
int sd;
};
typedef struct {
const char *sockname; /* The base name for the socket */
const char *fullsockname; /* socket base name + extension */
int sd; /* The socket descriptor */
int sd2; /* The socket descriptor */
} perchild_server_conf;
typedef struct child_info_t child_info_t;
/* Tables used to determine the user and group each child process should
* run as. The hash table is used to correlate a server name with a child
* process.
*/
static child_info_t *child_info_table;
static int *thread_socket_table;
struct ap_ctable *ap_child_table;
/*
* The max child slot ever assigned, preserved across restarts. Necessary
* to deal with NumServers changes across AP_SIG_GRACEFUL restarts. We
* use this value to optimize routines that have to scan the entire child
* table.
*
* XXX - It might not be worth keeping this code in. There aren't very
* many child processes in this MPM.
*/
int ap_max_daemons_limit = -1;
int ap_threads_per_child; /* XXX not part of API! axe it! */
module AP_MODULE_DECLARE_DATA mpm_perchild_module;
static apr_file_t *pipe_of_death_in = NULL;
static apr_file_t *pipe_of_death_out = NULL;
static apr_lock_t *pipe_of_death_mutex;
/* *Non*-shared http_main globals... */
server_rec *ap_server_conf;
/* one_process --- debugging mode variable; can be set from the command line
* with the -X flag. If set, this gets you the child_main loop running
* in the process which originally started up (no detach, no make_child),
* which is a pretty nice debugging environment. (You'll get a SIGHUP
* early in standalone_main; just continue through. This is the server
* trying to kill off any child processes which it might have lying
* around --- Apache doesn't keep track of their pids, it just sends
* SIGHUP to the process group, ignoring it in the root process.
* Continue through and you'll be fine.).
*/
static int one_process = 0;
#ifdef DEBUG_SIGSTOP
int raise_sigstop_flags;
#endif
static apr_pool_t *pconf; /* Pool for config stuff */
static apr_pool_t *pchild; /* Pool for httpd child stuff */
static apr_pool_t *thread_pool_parent; /* Parent of per-thread pools */
static apr_lock_t *thread_pool_parent_mutex;
static int child_num;
static unsigned int my_pid; /* Linux getpid() doesn't work except in
main thread. Use this instead */
/* Keep track of the number of worker threads currently active */
static int worker_thread_count;
static apr_lock_t *worker_thread_count_mutex;
static int *worker_thread_free_ids;
static apr_threadattr_t *worker_thread_attr;
/* Keep track of the number of idle worker threads */
static int idle_thread_count;
static apr_lock_t *idle_thread_count_mutex;
/* Locks for accept serialization */
#ifdef NO_SERIALIZED_ACCEPT
#define SAFE_ACCEPT(stmt) APR_SUCCESS
#else
#define SAFE_ACCEPT(stmt) (stmt)
static apr_lock_t *process_accept_mutex;
#endif /* NO_SERIALIZED_ACCEPT */
static apr_lock_t *thread_accept_mutex;
AP_DECLARE(apr_status_t) ap_mpm_query(int query_code, int *result)
{
switch(query_code){
case AP_MPMQ_MAX_DAEMON_USED:
*result = ap_max_daemons_limit;
return APR_SUCCESS;
case AP_MPMQ_IS_THREADED:
*result = AP_MPMQ_DYNAMIC;
return APR_SUCCESS;
case AP_MPMQ_IS_FORKED:
*result = AP_MPMQ_STATIC;
return APR_SUCCESS;
case AP_MPMQ_HARD_LIMIT_DAEMONS:
*result = server_limit;
return APR_SUCCESS;
case AP_MPMQ_HARD_LIMIT_THREADS:
*result = thread_limit;
return APR_SUCCESS;
case AP_MPMQ_MAX_THREADS:
*result = max_threads;
return APR_SUCCESS;
case AP_MPMQ_MIN_SPARE_DAEMONS:
*result = 0;
return APR_SUCCESS;
case AP_MPMQ_MIN_SPARE_THREADS:
*result = min_spare_threads;
return APR_SUCCESS;
case AP_MPMQ_MAX_SPARE_DAEMONS:
*result = 0;
return APR_SUCCESS;
case AP_MPMQ_MAX_SPARE_THREADS:
*result = max_spare_threads;
return APR_SUCCESS;
case AP_MPMQ_MAX_REQUESTS_DAEMON:
*result = max_requests_per_child;
return APR_SUCCESS;
case AP_MPMQ_MAX_DAEMONS:
*result = num_daemons;
return APR_SUCCESS;
}
return APR_ENOTIMPL;
}
/* a clean exit from a child with proper cleanup */
static void clean_child_exit(int code)
{
if (pchild) {
apr_pool_destroy(pchild);
}
exit(code);
}
/* handle all varieties of core dumping signals */
static void sig_coredump(int sig)
{
chdir(ap_coredump_dir);
apr_signal(sig, SIG_DFL);
kill(getpid(), sig);
/* At this point we've got sig blocked, because we're still inside
* the signal handler. When we leave the signal handler it will
* be unblocked, and we'll take the signal... and coredump or whatever
* is appropriate for this particular Unix. In addition the parent
* will see the real signal we received -- whereas if we called
* abort() here, the parent would only see SIGABRT.
*/
}
static void just_die(int sig)
{
clean_child_exit(0);
}
/*****************************************************************
* Connection structures and accounting...
*/
/* volatile just in case */
static int volatile shutdown_pending;
static int volatile restart_pending;
static int volatile is_graceful;
static int volatile child_fatal;
/* we don't currently track ap_my_generation, but mod_status
* references it so it must be defined */
ap_generation_t volatile ap_my_generation=0;
/*
* ap_start_shutdown() and ap_start_restart(), below, are a first stab at
* functions to initiate shutdown or restart without relying on signals.
* Previously this was initiated in sig_term() and restart() signal handlers,
* but we want to be able to start a shutdown/restart from other sources --
* e.g. on Win32, from the service manager. Now the service manager can
* call ap_start_shutdown() or ap_start_restart() as appropiate. Note that
* these functions can also be called by the child processes, since global
* variables are no longer used to pass on the required action to the parent.
*
* These should only be called from the parent process itself, since the
* parent process will use the shutdown_pending and restart_pending variables
* to determine whether to shutdown or restart. The child process should
* call signal_parent() directly to tell the parent to die -- this will
* cause neither of those variable to be set, which the parent will
* assume means something serious is wrong (which it will be, for the
* child to force an exit) and so do an exit anyway.
*/
static void ap_start_shutdown(void)
{
if (shutdown_pending == 1) {
/* Um, is this _probably_ not an error, if the user has
* tried to do a shutdown twice quickly, so we won't
* worry about reporting it.
*/
return;
}
shutdown_pending = 1;
}
/* do a graceful restart if graceful == 1 */
static void ap_start_restart(int graceful)
{
if (restart_pending == 1) {
/* Probably not an error - don't bother reporting it */
return;
}
restart_pending = 1;
is_graceful = graceful;
if (is_graceful) {
apr_pool_cleanup_kill(pconf, NULL, ap_cleanup_scoreboard);
}
}
static void sig_term(int sig)
{
ap_start_shutdown();
}
static void restart(int sig)
{
#ifndef WIN32
ap_start_restart(sig == AP_SIG_GRACEFUL);
#else
ap_start_restart(1);
#endif
}
static void set_signals(void)
{
#ifndef NO_USE_SIGACTION
struct sigaction sa;
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
if (!one_process) {
sa.sa_handler = sig_coredump;
#if defined(SA_ONESHOT)
sa.sa_flags = SA_ONESHOT;
#elif defined(SA_RESETHAND)
sa.sa_flags = SA_RESETHAND;
#endif
if (sigaction(SIGSEGV, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
"sigaction(SIGSEGV)");
#ifdef SIGBUS
if (sigaction(SIGBUS, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
"sigaction(SIGBUS)");
#endif
#ifdef SIGABORT
if (sigaction(SIGABORT, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
"sigaction(SIGABORT)");
#endif
#ifdef SIGABRT
if (sigaction(SIGABRT, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
"sigaction(SIGABRT)");
#endif
#ifdef SIGILL
if (sigaction(SIGILL, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
"sigaction(SIGILL)");
#endif
sa.sa_flags = 0;
}
sa.sa_handler = sig_term;
if (sigaction(SIGTERM, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
"sigaction(SIGTERM)");
#ifdef SIGINT
if (sigaction(SIGINT, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
"sigaction(SIGINT)");
#endif
#ifdef SIGXCPU
sa.sa_handler = SIG_DFL;
if (sigaction(SIGXCPU, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
"sigaction(SIGXCPU)");
#endif
#ifdef SIGXFSZ
sa.sa_handler = SIG_DFL;
if (sigaction(SIGXFSZ, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
"sigaction(SIGXFSZ)");
#endif
#ifdef SIGPIPE
sa.sa_handler = SIG_IGN;
if (sigaction(SIGPIPE, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
"sigaction(SIGPIPE)");
#endif
/* we want to ignore HUPs and AP_SIG_GRACEFUL while we're busy
* processing one */
sigaddset(&sa.sa_mask, SIGHUP);
sigaddset(&sa.sa_mask, AP_SIG_GRACEFUL);
sa.sa_handler = restart;
if (sigaction(SIGHUP, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
"sigaction(SIGHUP)");
if (sigaction(AP_SIG_GRACEFUL, &sa, NULL) < 0)
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
"sigaction(" AP_SIG_GRACEFUL_STRING ")");
#else
if (!one_process) {
apr_signal(SIGSEGV, sig_coredump);
#ifdef SIGBUS
apr_signal(SIGBUS, sig_coredump);
#endif /* SIGBUS */
#ifdef SIGABORT
apr_signal(SIGABORT, sig_coredump);
#endif /* SIGABORT */
#ifdef SIGABRT
apr_signal(SIGABRT, sig_coredump);
#endif /* SIGABRT */
#ifdef SIGILL
apr_signal(SIGILL, sig_coredump);
#endif /* SIGILL */
#ifdef SIGXCPU
apr_signal(SIGXCPU, SIG_DFL);
#endif /* SIGXCPU */
#ifdef SIGXFSZ
apr_signal(SIGXFSZ, SIG_DFL);
#endif /* SIGXFSZ */
}
apr_signal(SIGTERM, sig_term);
#ifdef SIGHUP
apr_signal(SIGHUP, restart);
#endif /* SIGHUP */
#ifdef AP_SIG_GRACEFUL
apr_signal(AP_SIG_GRACEFUL, restart);
#endif /* AP_SIG_GRACEFUL */
#ifdef SIGPIPE
apr_signal(SIGPIPE, SIG_IGN);
#endif /* SIGPIPE */
#endif
}
/*****************************************************************
* Here follows a long bunch of generic server bookkeeping stuff...
*/
int ap_graceful_stop_signalled(void)
{
/* XXX - Does this really work? - Manoj */
return is_graceful;
}
/*****************************************************************
* Child process main loop.
*/
static void process_socket(apr_pool_t *p, apr_socket_t *sock, long conn_id)
{
conn_rec *current_conn;
int csd;
apr_status_t rv;
int thread_num = conn_id % thread_limit;
void *sbh;
if ((rv = apr_os_sock_get(&csd, sock)) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv, NULL, "apr_os_sock_get");
}
if (csd >= FD_SETSIZE) {
ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_WARNING, 0, NULL,
"new file descriptor %d is too large; you probably need "
"to rebuild Apache with a larger FD_SETSIZE "
"(currently %d)",
csd, FD_SETSIZE);
apr_socket_close(sock);
return;
}
if (thread_socket_table[thread_num] < 0) {
ap_sock_disable_nagle(sock);
}
ap_create_sb_handle(&sbh, p, conn_id / thread_limit, thread_num);
current_conn = ap_run_create_connection(p, ap_server_conf, sock, conn_id, sbh);
if (current_conn) {
ap_process_connection(current_conn);
ap_lingering_close(current_conn);
}
}
static void *worker_thread(apr_thread_t *, void *);
/* Starts a thread as long as we're below max_threads */
static int start_thread(void)
{
apr_thread_t *thread;
int rc;
apr_lock_acquire(worker_thread_count_mutex);
if (worker_thread_count < max_threads - 1) {
rc = apr_thread_create(&thread, worker_thread_attr, worker_thread,
&worker_thread_free_ids[worker_thread_count], pchild);
if (rc != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ALERT, rc, ap_server_conf,
"apr_thread_create: unable to create worker thread");
/* In case system resources are maxxed out, we don't want
Apache running away with the CPU trying to fork over and
over and over again if we exit. */
sleep(10);
workers_may_exit = 1;
apr_lock_release(worker_thread_count_mutex);
return 0;
}
else {
worker_thread_count++;
}
}
else {
static int reported = 0;
if (!reported) {
ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, 0,
ap_server_conf,
"server reached MaxThreadsPerChild setting, "
"consider raising the MaxThreadsPerChild or "
"NumServers settings");
reported = 1;
}
apr_lock_release(worker_thread_count_mutex);
return 0;
}
apr_lock_release(worker_thread_count_mutex);
return 1;
}
/* Sets workers_may_exit if we received a character on the pipe_of_death */
static void check_pipe_of_death(void)
{
apr_lock_acquire(pipe_of_death_mutex);
if (!workers_may_exit) {
int ret;
char pipe_read_char;
apr_size_t n = 1;
ret = apr_recv(listenfds[0], &pipe_read_char, &n);
if (APR_STATUS_IS_EAGAIN(ret)) {
/* It lost the lottery. It must continue to suffer
* through a life of servitude. */
}
else {
/* It won the lottery (or something else is very
* wrong). Embrace death with open arms. */
workers_may_exit = 1;
}
}
apr_lock_release(pipe_of_death_mutex);
}
/* idle_thread_count should be incremented before starting a worker_thread */
static void *worker_thread(apr_thread_t *thd, void *arg)
{
apr_socket_t *csd = NULL;
apr_pool_t *tpool; /* Pool for this thread */
apr_pool_t *ptrans; /* Pool for per-transaction stuff */
apr_socket_t *sd = NULL;
volatile int last_pollfd = 0;
volatile int thread_just_started = 1;
int srv;
int curr_pollfd;
int thread_num = *((int *) arg);
long conn_id = child_num * thread_limit + thread_num;
apr_pollfd_t *pollset;
int n;
apr_status_t rv;
apr_lock_acquire(thread_pool_parent_mutex);
apr_pool_create(&tpool, thread_pool_parent);
apr_lock_release(thread_pool_parent_mutex);
apr_pool_create(&ptrans, tpool);
(void) ap_update_child_status_from_indexes(child_num, thread_num,
SERVER_STARTING,
(request_rec *) NULL);
apr_poll_setup(&pollset, num_listenfds+1, tpool);
for(n = 0; n <= num_listenfds; ++n) {
apr_poll_socket_add(pollset, listenfds[n], APR_POLLIN);
}
while (!workers_may_exit) {
workers_may_exit |= (max_requests_per_child != 0)
&& (requests_this_child <= 0);
if (workers_may_exit) break;
if (!thread_just_started) {
apr_lock_acquire(idle_thread_count_mutex);
if (idle_thread_count < max_spare_threads) {
idle_thread_count++;
apr_lock_release(idle_thread_count_mutex);
}
else {
apr_lock_release(idle_thread_count_mutex);
break;
}
}
else {
thread_just_started = 0;
}
(void) ap_update_child_status_from_indexes(child_num, thread_num,
SERVER_READY,
(request_rec *) NULL);
apr_lock_acquire(thread_accept_mutex);
if (workers_may_exit) {
apr_lock_release(thread_accept_mutex);
break;
}
if ((rv = SAFE_ACCEPT(apr_lock_acquire(process_accept_mutex)))
!= APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf,
"apr_lock_acquire failed. Attempting to shutdown "
"process gracefully.");
workers_may_exit = 1;
}
while (!workers_may_exit) {
apr_int16_t event;
srv = apr_poll(pollset, &n, -1);
if (srv != APR_SUCCESS) {
if (APR_STATUS_IS_EINTR(srv)) {
continue;
}
/* apr_poll() will only return errors in catastrophic
* circumstances. Let's try exiting gracefully, for now. */
ap_log_error(APLOG_MARK, APLOG_ERR, srv, (const server_rec *)
ap_server_conf, "apr_poll: (listen)");
workers_may_exit = 1;
}
if (workers_may_exit) break;
apr_poll_revents_get(&event, listenfds[0], pollset);
if (event & APR_POLLIN) {
/* A process got a signal on the shutdown pipe. Check if we're
* the lucky process to die. */
check_pipe_of_death();
continue;
}
apr_poll_revents_get(&event, listenfds[1], pollset);
if (event & APR_POLLIN || event & APR_POLLOUT) {
/* This request is from another child in our current process.
* We should set a flag here, and then below we will read
* two bytes (the socket number and the NULL byte.
*/
thread_socket_table[thread_num] = AP_PERCHILD_OTHERCHILD;
goto got_from_other_child;
}
if (num_listenfds == 1) {
sd = ap_listeners->sd;
goto got_fd;
}
else {
/* find a listener */
curr_pollfd = last_pollfd;
do {
curr_pollfd++;
if (curr_pollfd > num_listenfds) {
curr_pollfd = 1;
}
/* XXX: Should we check for POLLERR? */
apr_poll_revents_get(&event, listenfds[curr_pollfd],
pollset);
if (event & APR_POLLIN) {
last_pollfd = curr_pollfd;
sd = listenfds[curr_pollfd];
goto got_fd;
}
} while (curr_pollfd != last_pollfd);
}
}
got_fd:
if (!workers_may_exit) {
if ((rv = apr_accept(&csd, sd, ptrans)) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv, ap_server_conf,
"apr_accept");
}
if ((rv = SAFE_ACCEPT(apr_lock_release(process_accept_mutex)))
!= APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf,
"apr_lock_release failed. Attempting to shutdown "
"process gracefully.");
workers_may_exit = 1;
}
apr_lock_release(thread_accept_mutex);
apr_lock_acquire(idle_thread_count_mutex);
if (idle_thread_count > min_spare_threads) {
idle_thread_count--;
}
else {
if (!start_thread()) {
idle_thread_count--;
}
}
apr_lock_release(idle_thread_count_mutex);
got_from_other_child:
if (thread_socket_table[thread_num] == AP_PERCHILD_OTHERCHILD) {
struct msghdr msg;
struct cmsghdr *cmsg;
char sockname[80];
struct iovec iov;
int ret, sd, dp;
iov.iov_base = sockname;
iov.iov_len = 80;
msg.msg_name = NULL;
msg.msg_namelen = 0;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
cmsg = apr_palloc(ptrans, sizeof(*cmsg) + sizeof(sd));
cmsg->cmsg_len = sizeof(*cmsg) + sizeof(sd);
msg.msg_control = (caddr_t)cmsg;
msg.msg_controllen = cmsg->cmsg_len;
msg.msg_flags = 0;
ret = recvmsg(child_info_table[child_num].sd, &msg, 0);
memcpy(&dp, CMSG_DATA(cmsg), sizeof(dp));
thread_socket_table[thread_num] = dp;
apr_os_sock_put(&csd, &child_info_table[child_num].sd, ptrans);
}
if (setjmp(jmpbuffer) != 1) {
process_socket(ptrans, csd, conn_id);
}
else {
thread_socket_table[thread_num] = AP_PERCHILD_THISCHILD;
}
requests_this_child--;
}
else {
if ((rv = SAFE_ACCEPT(apr_lock_release(process_accept_mutex)))
!= APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf,
"apr_lock_release failed. Attempting to shutdown "
"process gracefully.");
workers_may_exit = 1;
}
apr_lock_release(thread_accept_mutex);
apr_lock_acquire(idle_thread_count_mutex);
idle_thread_count--;
apr_lock_release(idle_thread_count_mutex);
break;
}
apr_pool_clear(ptrans);
}
apr_lock_acquire(thread_pool_parent_mutex);
ap_update_child_status_from_indexes(child_num, thread_num, SERVER_DEAD,
(request_rec *) NULL);
apr_pool_destroy(tpool);
apr_lock_release(thread_pool_parent_mutex);
apr_lock_acquire(worker_thread_count_mutex);
worker_thread_count--;
worker_thread_free_ids[worker_thread_count] = thread_num;
if (worker_thread_count == 0) {
/* All the threads have exited, now finish the shutdown process
* by signalling the sigwait thread */
kill(my_pid, SIGTERM);
}
apr_lock_release(worker_thread_count_mutex);
return NULL;
}
/* Set group privileges.
*
* Note that we use the username as set in the config files, rather than
* the lookup of to uid --- the same uid may have multiple passwd entries,
* with different sets of groups for each.
*/
static int set_group_privs(uid_t uid, gid_t gid)
{
if (!geteuid()) {
const char *name;
/* Get username if passed as a uid */
struct passwd *ent;
if ((ent = getpwuid(uid)) == NULL) {
ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL,
"getpwuid: couldn't determine user name from uid %u, "
"you probably need to modify the User directive",
(unsigned)uid);
return -1;
}
name = ent->pw_name;
/*
* Set the GID before initgroups(), since on some platforms
* setgid() is known to zap the group list.
*/
if (setgid(gid) == -1) {
ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL,
"setgid: unable to set group id to Group %u",
(unsigned)gid);
return -1;
}
/* Reset `groups' attributes. */
if (initgroups(name, gid) == -1) {
ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL,
"initgroups: unable to set groups for User %s "
"and Group %u", name, (unsigned)gid);
return -1;
}
}
return 0;
}
static int perchild_setup_child(int childnum)
{
child_info_t *ug = &child_info_table[childnum];
if (ug->uid == -1 && ug->gid == -1) {
return unixd_setup_child();
}
if (set_group_privs(ug->uid, ug->gid)) {
return -1;
}
/* Only try to switch if we're running as root */
if (!geteuid()
&& (
#ifdef _OSD_POSIX
os_init_job_environment(server_conf, unixd_config.user_name,
one_process) != 0 ||
#endif
setuid(ug->uid) == -1)) {
ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL,
"setuid: unable to change to uid: %ld",
(long) ug->uid);
return -1;
}
return 0;
}
static int check_signal(int signum)
{
switch (signum) {
case SIGTERM:
case SIGINT:
just_die(signum);
return 1;
}
return 0;
}
static void child_main(int child_num_arg)
{
int i;
ap_listen_rec *lr;
apr_status_t rv;
my_pid = getpid();
child_num = child_num_arg;
apr_pool_create(&pchild, pconf);
/*stuff to do before we switch id's, so we have permissions.*/
rv = SAFE_ACCEPT(apr_lock_child_init(&process_accept_mutex, ap_lock_fname,
pchild));
if (rv != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_EMERG, rv, ap_server_conf,
"Couldn't initialize cross-process lock in child");
clean_child_exit(APEXIT_CHILDFATAL);
}
if (perchild_setup_child(child_num)) {
clean_child_exit(APEXIT_CHILDFATAL);
}
ap_run_child_init(pchild, ap_server_conf);
/*done with init critical section */
apr_setup_signal_thread();
requests_this_child = max_requests_per_child;
/* Set up the pollfd array, num_listenfds + 1 for the pipe and 1 for
* the child socket.
*/
listenfds = apr_pcalloc(pchild, sizeof(*listenfds) * (num_listenfds + 2));
#if APR_FILES_AS_SOCKETS
apr_socket_from_file(&listenfds[0], pipe_of_death_in);
#endif
/* The child socket */
apr_os_sock_put(&listenfds[1], &child_info_table[child_num].sd, pchild);
num_listenfds++;
for (lr = ap_listeners, i = 2; i <= num_listenfds; lr = lr->next, ++i) {
listenfds[i]=lr->sd;
}
/* Setup worker threads */
if (threads_to_start > max_threads) {
threads_to_start = max_threads;
}
idle_thread_count = threads_to_start;
worker_thread_count = 0;
worker_thread_free_ids = (int *)apr_pcalloc(pchild, thread_limit * sizeof(int));
for (i = 0; i < max_threads; i++) {
worker_thread_free_ids[i] = i;
}
apr_pool_create(&thread_pool_parent, pchild);
apr_lock_create(&thread_pool_parent_mutex, APR_MUTEX, APR_INTRAPROCESS,
APR_LOCK_DEFAULT, NULL, pchild);
apr_lock_create(&idle_thread_count_mutex, APR_MUTEX, APR_INTRAPROCESS,
APR_LOCK_DEFAULT, NULL, pchild);
apr_lock_create(&worker_thread_count_mutex, APR_MUTEX, APR_INTRAPROCESS,
APR_LOCK_DEFAULT, NULL, pchild);
apr_lock_create(&pipe_of_death_mutex, APR_MUTEX, APR_INTRAPROCESS,
APR_LOCK_DEFAULT, NULL, pchild);
apr_lock_create(&thread_accept_mutex, APR_MUTEX, APR_INTRAPROCESS,
APR_LOCK_DEFAULT, NULL, pchild);
apr_threadattr_create(&worker_thread_attr, pchild);
apr_threadattr_detach_set(worker_thread_attr, 1);
/* We are creating worker threads right now */
for (i=0; i < threads_to_start; i++) {
/* start_thread shouldn't fail here */
if (!start_thread()) {
break;
}
}
apr_signal_thread(check_signal);
}
static int make_child(server_rec *s, int slot)
{
int pid;
if (slot + 1 > ap_max_daemons_limit) {
ap_max_daemons_limit = slot + 1;
}
if (one_process) {
set_signals();
ap_child_table[slot].pid = getpid();
ap_child_table[slot].status = SERVER_ALIVE;
child_main(slot);
}
(void) ap_update_child_status_from_indexes(slot, 0, SERVER_STARTING,
(request_rec *) NULL);
if ((pid = fork()) == -1) {
ap_log_error(APLOG_MARK, APLOG_ERR, errno, s,
"fork: Unable to fork new process");
/* In case system resources are maxxed out, we don't want
* Apache running away with the CPU trying to fork over and
* over and over again. */
sleep(10);
return -1;
}
if (!pid) {
#ifdef HAVE_BINDPROCESSOR
/* By default, AIX binds to a single processor. This bit unbinds
* children which will then bind to another CPU.
*/
int status = bindprocessor(BINDPROCESS, (int)getpid(),
PROCESSOR_CLASS_ANY);
if (status != OK) {
ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_WARNING, errno,
ap_server_conf, "processor unbind failed %d", status);
}
#endif
RAISE_SIGSTOP(MAKE_CHILD);
/* XXX - For an unthreaded server, a signal handler will be necessary
* apr_signal(SIGTERM, just_die);
*/
child_main(slot);
clean_child_exit(0);
}
/* else */
ap_child_table[slot].pid = pid;
ap_child_table[slot].status = SERVER_ALIVE;
return 0;
}
/* start up a bunch of children */
static int startup_children(int number_to_start)
{
int i;
for (i = 0; number_to_start && i < num_daemons; ++i) {
if (ap_child_table[i].pid) {
continue;
}
if (make_child(ap_server_conf, i) < 0) {
break;
}
--number_to_start;
}
return number_to_start;
}
/*
* spawn_rate is the number of children that will be spawned on the
* next maintenance cycle if there aren't enough servers. It is
* doubled up to MAX_SPAWN_RATE, and reset only when a cycle goes by
* without the need to spawn.
*/
static int spawn_rate = 1;
#ifndef MAX_SPAWN_RATE
#define MAX_SPAWN_RATE (32)
#endif
static int hold_off_on_exponential_spawning;
static void perform_child_maintenance(void)
{
int i;
int free_length;
int free_slots[MAX_SPAWN_RATE];
int last_non_dead = -1;
/* initialize the free_list */
free_length = 0;
for (i = 0; i < num_daemons; ++i) {
if (ap_child_table[i].pid == 0) {
if (free_length < spawn_rate) {
free_slots[free_length] = i;
++free_length;
}
}
else {
last_non_dead = i;
}
if (i >= ap_max_daemons_limit && free_length >= spawn_rate) {
break;
}
}
ap_max_daemons_limit = last_non_dead + 1;
if (free_length > 0) {
for (i = 0; i < free_length; ++i) {
make_child(ap_server_conf, free_slots[i]);
}
/* the next time around we want to spawn twice as many if this
* wasn't good enough, but not if we've just done a graceful
*/
if (hold_off_on_exponential_spawning) {
--hold_off_on_exponential_spawning;
}
else if (spawn_rate < MAX_SPAWN_RATE) {
spawn_rate *= 2;
}
}
else {
spawn_rate = 1;
}
}
static void server_main_loop(int remaining_children_to_start)
{
int child_slot;
apr_exit_why_e exitwhy;
int status;
apr_proc_t pid;
int i;
while (!restart_pending && !shutdown_pending) {
ap_wait_or_timeout(&exitwhy, &status, &pid, pconf);
if (pid.pid != -1) {
if (ap_process_child_status(&pid, exitwhy, status)
== APEXIT_CHILDFATAL) {
shutdown_pending = 1;
child_fatal = 1;
return;
}
/* non-fatal death... note that it's gone in the child table and
* clean out the status table. */
child_slot = -1;
for (i = 0; i < ap_max_daemons_limit; ++i) {
if (ap_child_table[i].pid == pid.pid) {
child_slot = i;
break;
}
}
if (child_slot >= 0) {
ap_child_table[child_slot].pid = 0;
ap_update_child_status_from_indexes(child_slot, i, SERVER_DEAD,
(request_rec *) NULL);
if (remaining_children_to_start
&& child_slot < num_daemons) {
/* we're still doing a 1-for-1 replacement of dead
* children with new children
*/
make_child(ap_server_conf, child_slot);
--remaining_children_to_start;
}
#if APR_HAS_OTHER_CHILD
}
else if (apr_proc_other_child_read(&pid, status) == 0) {
/* handled */
#endif
}
else if (is_graceful) {
/* Great, we've probably just lost a slot in the
* child table. Somehow we don't know about this
* child.
*/
ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_WARNING, 0,
ap_server_conf,
"long lost child came home! (pid %ld)",
(long)pid.pid);
}
/* Don't perform idle maintenance when a child dies,
* only do it when there's a timeout. Remember only a
* finite number of children can die, and it's pretty
* pathological for a lot to die suddenly.
*/
continue;
}
else if (remaining_children_to_start) {
/* we hit a 1 second timeout in which none of the previous
* generation of children needed to be reaped... so assume
* they're all done, and pick up the slack if any is left.
*/
remaining_children_to_start = \
startup_children(remaining_children_to_start);
/* In any event we really shouldn't do the code below because
* few of the servers we just started are in the IDLE state
* yet, so we'd mistakenly create an extra server.
*/
continue;
}
perform_child_maintenance();
}
}
int ap_mpm_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s)
{
int remaining_children_to_start;
int i;
apr_status_t rv;
apr_size_t one = 1;
pconf = _pconf;
ap_server_conf = s;
first_server_limit = server_limit;
first_thread_limit = thread_limit;
if (changed_limit_at_restart) {
ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_NOERRNO, 0, s,
"WARNING: Attempt to change ServerLimit or ThreadLimit "
"ignored during restart");
changed_limit_at_restart = 0;
}
if ((rv = apr_file_pipe_create(&pipe_of_death_in, &pipe_of_death_out,
pconf)) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv,
(const server_rec*) ap_server_conf,
"apr_file_pipe_create (pipe_of_death)");
exit(1);
}
if ((rv = apr_file_pipe_timeout_set(pipe_of_death_in, 0)) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv,
(const server_rec*) ap_server_conf,
"apr_file_pipe_timeout_set (pipe_of_death)");
exit(1);
}
ap_server_conf = s;
if ((num_listenfds = ap_setup_listeners(ap_server_conf)) < 1) {
/* XXX: hey, what's the right way for the mpm to indicate
* a fatal error? */
ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_ALERT, 0, s,
"no listening sockets available, shutting down");
return 1;
}
ap_log_pid(pconf, ap_pid_fname);
/* Initialize cross-process accept lock */
ap_lock_fname = apr_psprintf(_pconf, "%s.%u",
ap_server_root_relative(_pconf, ap_lock_fname),
my_pid);
rv = SAFE_ACCEPT(apr_lock_create(&process_accept_mutex, APR_MUTEX,
APR_CROSS_PROCESS, ap_accept_lock_mech,
ap_lock_fname, _pconf));
if (rv != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_EMERG, rv, s,
"Couldn't create cross-process lock");
return 1;
}
if (!is_graceful) {
ap_run_pre_mpm(pconf, SB_SHARED);
}
/* Initialize the child table */
if (!is_graceful) {
for (i = 0; i < server_limit; i++) {
ap_child_table[i].pid = 0;
}
}
set_signals();
/* If we're doing a graceful_restart then we're going to see a lot
* of children exiting immediately when we get into the main loop
* below (because we just sent them AP_SIG_GRACEFUL). This happens
* pretty rapidly... and for each one that exits we'll start a new one
* until we reach at least daemons_min_free. But we may be permitted to
* start more than that, so we'll just keep track of how many we're
* supposed to start up without the 1 second penalty between each fork.
*/
remaining_children_to_start = num_daemons;
if (!is_graceful) {
remaining_children_to_start = \
startup_children(remaining_children_to_start);
}
else {
/* give the system some time to recover before kicking into
* exponential mode */
hold_off_on_exponential_spawning = 10;
}
ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0, ap_server_conf,
"%s configured -- resuming normal operations",
ap_get_server_version());
ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, 0, ap_server_conf,
"Server built: %s", ap_get_server_built());
restart_pending = shutdown_pending = 0;
server_main_loop(remaining_children_to_start);
if (shutdown_pending) {
/* Time to gracefully shut down:
* Kill child processes, tell them to call child_exit, etc...
*/
if (unixd_killpg(getpgrp(), SIGTERM) < 0) {
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
"killpg SIGTERM");
}
ap_reclaim_child_processes(1); /* Start with SIGTERM */
if (!child_fatal) {
/* cleanup pid file on normal shutdown */
const char *pidfile = NULL;
pidfile = ap_server_root_relative (pconf, ap_pid_fname);
if (pidfile != NULL && unlink(pidfile) == 0) {
ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, 0,
ap_server_conf,
"removed PID file %s (pid=%ld)",
pidfile, (long)getpid());
}
ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0,
ap_server_conf, "caught SIGTERM, shutting down");
}
return 1;
}
/* we've been told to restart */
apr_signal(SIGHUP, SIG_IGN);
if (one_process) {
/* not worth thinking about */
return 1;
}
if (is_graceful) {
char char_of_death = '!';
ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0,
ap_server_conf, AP_SIG_GRACEFUL_STRING " received. "
"Doing graceful restart");
/* This is mostly for debugging... so that we know what is still
* gracefully dealing with existing request.
*/
for (i = 0; i < num_daemons; ++i) {
if (ap_child_table[i].pid) {
ap_child_table[i].status = SERVER_DYING;
}
}
/* give the children the signal to die */
for (i = 0; i < num_daemons;) {
if ((rv = apr_file_write(pipe_of_death_out, &char_of_death,
&one)) != APR_SUCCESS) {
if (APR_STATUS_IS_EINTR(rv)) continue;
ap_log_error(APLOG_MARK, APLOG_WARNING, rv, ap_server_conf,
"write pipe_of_death");
}
i++;
}
}
else {
/* Kill 'em all. Since the child acts the same on the parents SIGTERM
* and a SIGHUP, we may as well use the same signal, because some user
* pthreads are stealing signals from us left and right.
*/
if (unixd_killpg(getpgrp(), SIGTERM) < 0) {
ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf,
"killpg SIGTERM");
}
ap_reclaim_child_processes(1); /* Start with SIGTERM */
ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0,
ap_server_conf, "SIGHUP received. Attempting to restart");
}
return 0;
}
static void perchild_pre_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp)
{
static int restart_num = 0;
int no_detach, debug;
ap_directive_t *pdir;
int i;
int tmp_server_limit = DEFAULT_SERVER_LIMIT;
int tmp_thread_limit = DEFAULT_THREAD_LIMIT;
debug = ap_exists_config_define("DEBUG");
if (debug) {
no_detach = one_process = 1;
}
else {
one_process = ap_exists_config_define("ONE_PROCESS");
no_detach = ap_exists_config_define("NO_DETACH");
}
/* sigh, want this only the second time around */
if (restart_num++ == 1) {
is_graceful = 0;
if (!one_process && !no_detach) {
apr_proc_detach();
}
my_pid = getpid();
}
unixd_pre_config(ptemp);
ap_listen_pre_config();
num_daemons = DEFAULT_NUM_DAEMON;
threads_to_start = DEFAULT_START_THREAD;
min_spare_threads = DEFAULT_MIN_SPARE_THREAD;
max_spare_threads = DEFAULT_MAX_SPARE_THREAD;
max_threads = thread_limit;
ap_pid_fname = DEFAULT_PIDLOG;
ap_scoreboard_fname = DEFAULT_SCOREBOARD;
ap_lock_fname = DEFAULT_LOCKFILE;
max_requests_per_child = DEFAULT_MAX_REQUESTS_PER_CHILD;
curr_child_num = 0;
apr_cpystrn(ap_coredump_dir, ap_server_root, sizeof(ap_coredump_dir));
/* we need to know ServerLimit and ThreadLimit before we start processing
* the tree because we need to already have allocated child_info_table
*/
for (pdir = ap_conftree; pdir != NULL; pdir = pdir->next) {
if (!strcasecmp(pdir->directive, "ServerLimit")) {
if (atoi(pdir->args) > tmp_server_limit) {
tmp_server_limit = atoi(pdir->args);
if (tmp_server_limit > MAX_SERVER_LIMIT) {
tmp_server_limit = MAX_SERVER_LIMIT;
}
}
}
else if (!strcasecmp(pdir->directive, "ThreadLimit")) {
if (atoi(pdir->args) > tmp_thread_limit) {
tmp_thread_limit = atoi(pdir->args);
if (tmp_thread_limit > MAX_THREAD_LIMIT) {
tmp_thread_limit = MAX_THREAD_LIMIT;
}
}
}
}
child_info_table = (child_info_t *)apr_pcalloc(p, tmp_server_limit * sizeof(child_info_t));
for (i = 0; i < tmp_server_limit; i++) {
child_info_table[i].uid = -1;
child_info_table[i].gid = -1;
child_info_table[i].sd = -1;
}
}
static int pass_request(request_rec *r)
{
apr_socket_t *thesock = ap_get_module_config(r->connection->conn_config, &core_module);
struct msghdr msg;
struct cmsghdr *cmsg;
int sfd;
struct iovec iov;
apr_bucket_brigade *bb = apr_brigade_create(r->pool);
perchild_server_conf *sconf = (perchild_server_conf *)
ap_get_module_config(r->server->module_config,
&mpm_perchild_module);
char *foo;
apr_size_t len;
apr_off_t zero = 0;
apr_pool_userdata_get((void **)&foo, "PERCHILD_BUFFER",
r->connection->pool);
len = strlen(foo);
apr_pool_userdata_set(NULL, "PERCHILD_BUFFER", apr_pool_cleanup_null,
r->connection->pool);
apr_os_sock_get(&sfd, thesock);
iov.iov_base = NULL;
iov.iov_len = 0;
msg.msg_name = NULL;
msg.msg_namelen = 0;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
cmsg = apr_palloc(r->pool, sizeof(*cmsg) + sizeof(sfd));
cmsg->cmsg_len = sizeof(*cmsg) + sizeof(int);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
memcpy(CMSG_DATA(cmsg), &sfd, sizeof(sfd));
msg.msg_control = (caddr_t)cmsg;
msg.msg_controllen = cmsg->cmsg_len;
msg.msg_flags=0;
if (sendmsg(sconf->sd2, &msg, 0) == -1) {
apr_pool_destroy(r->pool);
return -1;
}
write(sconf->sd2, foo, len);
/* ### this "read one line" doesn't seem right... shouldn't we be
### reading large chunks of data or something?
*/
while (ap_get_brigade(r->input_filters, bb, AP_MODE_NONBLOCKING,
&zero /* read one line */) == APR_SUCCESS) {
apr_bucket *e;
APR_BRIGADE_FOREACH(e, bb) {
const char *str;
apr_bucket_read(e, &str, &len, APR_NONBLOCK_READ);
write(sconf->sd2, str, len);
}
}
apr_pool_destroy(r->pool);
return 1;
}
static char *make_perchild_socket(const char *fullsockname, int sd[2])
{
socketpair(PF_UNIX, SOCK_STREAM, 0, sd);
return NULL;
}
static int perchild_post_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s)
{
int i;
server_rec *sr;
perchild_server_conf *sconf;
int def_sd[2];
def_sd[0] = -1;
def_sd[1] = -1;
for (sr = s; sr; sr = sr->next) {
sconf = (perchild_server_conf *)ap_get_module_config(sr->module_config,
&mpm_perchild_module);
if (sconf->sd == -1) {
sconf->fullsockname = apr_pstrcat(sr->process->pool,
sconf->sockname, ".DEFAULT", NULL);
if (def_sd[0] == -1) {
if (!make_perchild_socket(sconf->fullsockname, def_sd)) {
/* log error */
}
}
sconf->sd = def_sd[0];
sconf->sd2 = def_sd[1];
}
}
for (i = 0; i < num_daemons; i++) {
if (child_info_table[i].uid == -1) {
child_info_table[i].sd = def_sd[0];
}
}
thread_socket_table = (int *)apr_pcalloc(p, thread_limit * sizeof(int));
for (i = 0; i < thread_limit; i++) {
thread_socket_table[i] = AP_PERCHILD_THISCHILD;
}
ap_child_table = (ap_ctable *)apr_pcalloc(p, server_limit * sizeof(ap_ctable));
return OK;
}
static int perchild_post_read(request_rec *r)
{
ap_filter_t *f = r->connection->input_filters;
int thread_num = r->connection->id % thread_limit;
perchild_server_conf *sconf = (perchild_server_conf *)
ap_get_module_config(r->server->module_config,
&mpm_perchild_module);
while (f) {
if (!strcasecmp("PERCHILD_BUFFER", f->frec->name)) {
ap_remove_output_filter(f);
break;
}
f = f->next;
}
if (thread_socket_table[thread_num] != AP_PERCHILD_THISCHILD) {
apr_socket_t *csd = NULL;
apr_os_sock_put(&csd, &thread_socket_table[thread_num],
r->connection->pool);
ap_sock_disable_nagle(csd);
ap_set_module_config(r->connection->conn_config, &core_module, csd);
return OK;
}
else {
/* sconf is the server config for this vhost, so if our socket
* is not the same that was set in the config, then the request
* needs to be passed to another child. */
if (sconf->sd != child_info_table[child_num].sd) {
if (pass_request(r) == -1) {
ap_log_error(APLOG_MARK, APLOG_ERR | APLOG_NOERRNO, 0,
ap_server_conf, "Could not pass request to proper "
"child, request will not be honored.");
}
longjmp(jmpbuffer, 1);
}
return OK;
}
return OK;
}
static apr_status_t perchild_buffer(ap_filter_t *f, apr_bucket_brigade *b,
ap_input_mode_t mode, apr_off_t *readbytes)
{
apr_bucket *e;
apr_status_t rv;
char *buffer = NULL;
const char *str;
apr_size_t len;
if ((rv = ap_get_brigade(f->next, b, mode, readbytes)) != APR_SUCCESS) {
return rv;
}
apr_pool_userdata_get((void **)&buffer, "PERCHILD_BUFFER", f->c->pool);
APR_BRIGADE_FOREACH(e, b) {
if (e->length != 0) {
apr_bucket_read(e, &str, &len, APR_NONBLOCK_READ);
if (buffer == NULL) {
buffer = apr_pstrndup(f->c->pool, str, len);
}
else {
buffer = apr_pstrcat(f->c->pool, buffer,
apr_pstrndup(f->c->pool, str, len), NULL);
}
}
}
apr_pool_userdata_set(buffer, "PERCHILD_BUFFER", apr_pool_cleanup_null,
f->c->pool);
return APR_SUCCESS;
}
static int perchild_pre_connection(conn_rec *c)
{
ap_add_input_filter("PERCHILD_BUFFER", NULL, NULL, c);
return OK;
}
static void perchild_hooks(apr_pool_t *p)
{
one_process = 0;
ap_hook_pre_config(perchild_pre_config, NULL, NULL, APR_HOOK_MIDDLE);
ap_hook_post_config(perchild_post_config, NULL, NULL, APR_HOOK_MIDDLE);
ap_hook_pre_connection(perchild_pre_connection,NULL,NULL, APR_HOOK_MIDDLE);
/* This must be run absolutely first. If this request isn't for this
* server then we need to forward it to the proper child. No sense
* tying up this server running more post_read request hooks if it is
* just going to be forwarded along.
*/
ap_hook_post_read_request(perchild_post_read, NULL, NULL,
APR_HOOK_REALLY_FIRST);
ap_register_input_filter("PERCHILD_BUFFER", perchild_buffer,
AP_FTYPE_CONTENT);
}
static const char *set_num_daemons(cmd_parms *cmd, void *dummy,
const char *arg)
{
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
num_daemons = atoi(arg);
if (num_daemons > server_limit) {
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
"WARNING: NumServers of %d exceeds ServerLimit value "
"of %d servers,", num_daemons, server_limit);
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
" lowering NumServers to %d. To increase, please "
"see the", server_limit);
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
" ServerLimit directive.");
num_daemons = server_limit;
}
else if (num_daemons < 1) {
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
"WARNING: Require NumServers > 0, setting to 1");
num_daemons = 1;
}
return NULL;
}
static const char *set_threads_to_start(cmd_parms *cmd, void *dummy,
const char *arg)
{
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
threads_to_start = atoi(arg);
if (threads_to_start > thread_limit) {
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
"WARNING: StartThreads of %d exceeds ThreadLimit value"
" of %d threads,", threads_to_start,
thread_limit);
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
" lowering StartThreads to %d. To increase, please"
" see the", thread_limit);
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
" ThreadLimit directive.");
}
else if (threads_to_start < 1) {
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
"WARNING: Require StartThreads > 0, setting to 1");
threads_to_start = 1;
}
return NULL;
}
static const char *set_min_spare_threads(cmd_parms *cmd, void *dummy,
const char *arg)
{
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
min_spare_threads = atoi(arg);
if (min_spare_threads <= 0) {
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
"WARNING: detected MinSpareThreads set to non-positive.");
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
"Resetting to 1 to avoid almost certain Apache failure.");
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
"Please read the documentation.");
min_spare_threads = 1;
}
return NULL;
}
static const char *set_max_spare_threads(cmd_parms *cmd, void *dummy,
const char *arg)
{
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
max_spare_threads = atoi(arg);
if (max_spare_threads >= thread_limit) {
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
"WARNING: detected MinSpareThreads set higher than");
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
"ThreadLimit. Resetting to %d", thread_limit);
max_spare_threads = thread_limit;
}
return NULL;
}
static const char *set_max_threads(cmd_parms *cmd, void *dummy, const char *arg)
{
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
max_threads = atoi(arg);
if (max_threads > thread_limit) {
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
"WARNING: detected MaxThreadsPerChild set higher than");
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
"ThreadLimit. Resetting to %d", thread_limit);
max_threads = thread_limit;
}
return NULL;
}
static const char *set_child_per_uid(cmd_parms *cmd, void *dummy, const char *u,
const char *g, const char *num)
{
int i;
int max_this_time = atoi(num) + curr_child_num;
for (i = curr_child_num; i < max_this_time; i++, curr_child_num++) {
child_info_t *ug = &child_info_table[i - 1];
if (i > num_daemons) {
return "Trying to use more child ID's than NumServers. Increase "
"NumServers in your config file.";
}
ug->uid = atoi(u);
ug->gid = atoi(g);
}
return NULL;
}
static const char *assign_childuid(cmd_parms *cmd, void *dummy, const char *uid,
const char *gid)
{
int i;
int u = atoi(uid);
int g = atoi(gid);
const char *errstr;
int socks[2];
perchild_server_conf *sconf = (perchild_server_conf *)
ap_get_module_config(cmd->server->module_config,
&mpm_perchild_module);
sconf->fullsockname = apr_pstrcat(cmd->pool, sconf->sockname, ".", uid,
":", gid, NULL);
if ((errstr = make_perchild_socket(sconf->fullsockname, socks))) {
return errstr;
}
sconf->sd = socks[0];
sconf->sd2 = socks[1];
for (i = 0; i < num_daemons; i++) {
if (u == child_info_table[i].uid && g == child_info_table[i].gid) {
child_info_table[i].sd = sconf->sd;
}
}
return NULL;
}
static const char *set_server_limit (cmd_parms *cmd, void *dummy, const char *arg)
{
int tmp_server_limit;
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
tmp_server_limit = atoi(arg);
/* you cannot change ServerLimit across a restart; ignore
* any such attempts
*/
if (first_server_limit &&
tmp_server_limit != server_limit) {
/* how do we log a message? the error log is a bit bucket at this
* point; we'll just have to set a flag so that ap_mpm_run()
* logs a warning later
*/
changed_limit_at_restart = 1;
return NULL;
}
server_limit = tmp_server_limit;
if (server_limit > MAX_SERVER_LIMIT) {
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
"WARNING: ServerLimit of %d exceeds compile time limit "
"of %d servers,", server_limit, MAX_SERVER_LIMIT);
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
" lowering ServerLimit to %d.", MAX_SERVER_LIMIT);
server_limit = MAX_SERVER_LIMIT;
}
else if (server_limit < 1) {
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
"WARNING: Require ServerLimit > 0, setting to 1");
server_limit = 1;
}
return NULL;
}
static const char *set_thread_limit (cmd_parms *cmd, void *dummy, const char *arg)
{
int tmp_thread_limit;
const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
if (err != NULL) {
return err;
}
tmp_thread_limit = atoi(arg);
/* you cannot change ThreadLimit across a restart; ignore
* any such attempts
*/
if (first_thread_limit &&
tmp_thread_limit != thread_limit) {
/* how do we log a message? the error log is a bit bucket at this
* point; we'll just have to set a flag so that ap_mpm_run()
* logs a warning later
*/
changed_limit_at_restart = 1;
return NULL;
}
thread_limit = tmp_thread_limit;
if (thread_limit > MAX_THREAD_LIMIT) {
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
"WARNING: ThreadLimit of %d exceeds compile time limit "
"of %d servers,", thread_limit, MAX_THREAD_LIMIT);
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
" lowering ThreadLimit to %d.", MAX_THREAD_LIMIT);
thread_limit = MAX_THREAD_LIMIT;
}
else if (thread_limit < 1) {
ap_log_error(APLOG_MARK, APLOG_STARTUP | APLOG_NOERRNO, 0, NULL,
"WARNING: Require ThreadLimit > 0, setting to 1");
thread_limit = 1;
}
return NULL;
}
static const command_rec perchild_cmds[] = {
UNIX_DAEMON_COMMANDS,
LISTEN_COMMANDS,
AP_INIT_TAKE1("NumServers", set_num_daemons, NULL, RSRC_CONF,
"Number of children alive at the same time"),
AP_INIT_TAKE1("StartThreads", set_threads_to_start, NULL, RSRC_CONF,
"Number of threads each child creates"),
AP_INIT_TAKE1("MinSpareThreads", set_min_spare_threads, NULL, RSRC_CONF,
"Minimum number of idle threads per child, to handle "
"request spikes"),
AP_INIT_TAKE1("MaxSpareThreads", set_max_spare_threads, NULL, RSRC_CONF,
"Maximum number of idle threads per child"),
AP_INIT_TAKE1("MaxThreadsPerChild", set_max_threads, NULL, RSRC_CONF,
"Maximum number of threads per child"),
AP_INIT_TAKE3("ChildperUserID", set_child_per_uid, NULL, RSRC_CONF,
"Specify a User and Group for a specific child process."),
AP_INIT_TAKE2("AssignUserID", assign_childuid, NULL, RSRC_CONF,
"Tie a virtual host to a specific child process."),
AP_INIT_TAKE1("ServerLimit", set_server_limit, NULL, RSRC_CONF,
"Maximum value of NumServers for this run of Apache"),
AP_INIT_TAKE1("ThreadLimit", set_thread_limit, NULL, RSRC_CONF,
"Maximum worker threads in a server for this run of Apache"),
{ NULL }
};
static void *perchild_create_config(apr_pool_t *p, server_rec *s)
{
perchild_server_conf *c = (perchild_server_conf *)
apr_pcalloc(p, sizeof(perchild_server_conf));
c->sd = -1;
return c;
}
module AP_MODULE_DECLARE_DATA mpm_perchild_module = {
MPM20_MODULE_STUFF,
NULL, /* hook to run before apache parses args */
NULL, /* create per-directory config structure */
NULL, /* merge per-directory config structures */
perchild_create_config, /* create per-server config structure */
NULL, /* merge per-server config structures */
perchild_cmds, /* command apr_table_t */
perchild_hooks /* register_hooks */
};