mpm_common.h revision eacb724157bafd5062590305826ebc6fecb48cd2
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering/* Licensed to the Apache Software Foundation (ASF) under one or more
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * contributor license agreements. See the NOTICE file distributed with
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * this work for additional information regarding copyright ownership.
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * The ASF licenses this file to You under the Apache License, Version 2.0
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * (the "License"); you may not use this file except in compliance with
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * the License. You may obtain a copy of the License at
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * http://www.apache.org/licenses/LICENSE-2.0
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * Unless required by applicable law or agreed to in writing, software
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * distributed under the License is distributed on an "AS IS" BASIS,
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * See the License for the specific language governing permissions and
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * limitations under the License.
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering/* The purpose of this file is to store the code that MOST mpm's will need
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * this does not mean a function only goes into this file if every MPM needs
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * it. It means that if a function is needed by more than one MPM, and
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * future maintenance would be served by making the code common, then the
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * function belongs here.
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * This is going in src/main because it is not platform specific, it is
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * specific to multi-process servers, but NOT to Unix. Which is why it
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * does not belong in src/os/unix
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * @brief Multi-Processing Modules functions
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * @defgroup APACHE_MPM Multi-Processing Modules
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * @ingroup APACHE
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering#include <netinet/tcp.h> /* for TCP_NODELAY */
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering/* The maximum length of the queue of pending connections, as defined
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * by listen(2). Under some systems, it should be increased if you
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * are experiencing a heavy TCP SYN flood attack.
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * It defaults to 511 instead of 512 because some systems store it
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * as an 8-bit datatype; 512 truncated to 8-bits is 0, while 511 is
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * 255 when truncated.
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering/* Signal used to gracefully restart */
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering/* Signal used to gracefully restart (without SIG prefix) */
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering/* Signal used to gracefully restart (as a quoted string) */
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering/* Signal used to gracefully stop */
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering/* Signal used to gracefully stop (without SIG prefix) */
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering/* Signal used to gracefully stop (as a quoted string) */
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering#define AP_SIG_GRACEFUL_STOP_STRING "SIGWINCH"
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * Make sure all child processes that have been spawned by the parent process
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * have died. This includes process registered as "other_children".
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * @param terminate Either 1 or 0. If 1, send the child processes SIGTERM
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * each time through the loop. If 0, give the process time to die
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * on its own before signalling it.
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * @tip This function requires that some macros are defined by the MPM: <pre>
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * MPM_CHILD_PID -- Get the pid from the specified spot in the scoreboard
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * MPM_NOTE_CHILD_KILLED -- Note the child died in the scoreboard
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * @tip The MPM child processes which are reclaimed are those listed
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * in the scoreboard as well as those currently registered via
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * ap_register_extra_mpm_process().
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poetteringvoid ap_reclaim_child_processes(int terminate);
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * Catch any child processes that have been spawned by the parent process
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * which have exited. This includes processes registered as "other_children".
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * @tip This function requires that some macros are defined by the MPM: <pre>
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * MPM_CHILD_PID -- Get the pid from the specified spot in the scoreboard
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * MPM_NOTE_CHILD_KILLED -- Note the child died in the scoreboard
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * @tip The MPM child processes which are relieved are those listed
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * in the scoreboard as well as those currently registered via
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * ap_register_extra_mpm_process().
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * Tell ap_reclaim_child_processes() and ap_relieve_child_processes() about
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * an MPM child process which has no entry in the scoreboard.
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * @param pid The process id of an MPM child process which should be
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * reclaimed when ap_reclaim_child_processes() is called.
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * @tip If an extra MPM child process terminates prior to calling
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * ap_reclaim_child_processes(), remove it from the list of such processes
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * by calling ap_unregister_extra_mpm_process().
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poetteringvoid ap_register_extra_mpm_process(pid_t pid);
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * Unregister an MPM child process which was previously registered by a
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * call to ap_register_extra_mpm_process().
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * @param pid The process id of an MPM child process which no longer needs to
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * be reclaimed.
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * @return 1 if the process was found and removed, 0 otherwise
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poetteringint ap_unregister_extra_mpm_process(pid_t pid);
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * Safely signal an MPM child process, if the process is in the
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * current process group. Otherwise fail.
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * @param pid the process id of a child process to signal
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * @param sig the signal number to send
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * @return APR_SUCCESS if signal is sent, otherwise an error as per kill(3);
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * APR_EINVAL is returned if passed either an invalid (< 1) pid, or if
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * the pid is not in the current process group
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poetteringapr_status_t ap_mpm_safe_kill(pid_t pid, int sig);
a6a4f528899b1dab47408733b4a423c66ea40f7aThomas Hindoe Paaboel Andersen * Determine if any child process has died. If no child process died, then
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * this process sleeps for the amount of time specified by the MPM defined
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * macro SCOREBOARD_MAINTENANCE_INTERVAL.
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * @param status The return code if a process has died
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * @param ret The process id of the process that died
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * @param p The pool to allocate out of
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poetteringvoid ap_wait_or_timeout(apr_exit_why_e *status, int *exitcode, apr_proc_t *ret,
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * Log why a child died to the error log, if the child died without the
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * parent signalling it.
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * @param pid The child that has died
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * @param status The status returned from ap_wait_or_timeout
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * @return 0 on success, APEXIT_CHILDFATAL if MPM should terminate
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poetteringint ap_process_child_status(apr_proc_t *pid, apr_exit_why_e why, int status);
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * Turn off the nagle algorithm for the specified socket. The nagle algorithm
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * says that we should delay sending partial packets in the hopes of getting
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * more data. There are bad interactions between persistent connections and
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * Nagle's algorithm that have severe performance penalties.
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * @param s The socket to disable nagle for.
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poetteringvoid ap_sock_disable_nagle(apr_socket_t *s);
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering#define ap_sock_disable_nagle(s) /* NOOP */
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * Convert a username to a numeric ID
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * @param name The name to convert
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * @return The user id corresponding to a name
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * @fn uid_t ap_uname2id(const char *name)
ee8c45689526ca973407cbb77bce7b96a062c40bLennart PoetteringAP_DECLARE(uid_t) ap_uname2id(const char *name);
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * Convert a group name to a numeric ID
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * @param name The name to convert
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * @return The group id corresponding to a name
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * @fn gid_t ap_gname2id(const char *name)
f647962d64e844689f3e2acfce6102fc47e76df2Michal SchmidtAP_DECLARE(gid_t) ap_gname2id(const char *name);
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * Open the pipe-of-death. The pipe of death is used to tell all child
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * processes that it is time to die gracefully.
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * @param p The pool to use for allocating the pipe
f647962d64e844689f3e2acfce6102fc47e76df2Michal SchmidtAP_DECLARE(apr_status_t) ap_mpm_pod_open(apr_pool_t *p, ap_pod_t **pod);
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * Check the pipe to determine if the process has been signalled to die.
ee8c45689526ca973407cbb77bce7b96a062c40bLennart PoetteringAP_DECLARE(apr_status_t) ap_mpm_pod_check(ap_pod_t *pod);
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * Close the pipe-of-death
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart PoetteringAP_DECLARE(apr_status_t) ap_mpm_pod_close(ap_pod_t *pod);
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * Write data to the pipe-of-death, signalling that one child process
df3fb561b2df486a495a5f0bcc83168bd1860533Lennart Poettering * @param p The pool to use when allocating any required structures.
ee8c45689526ca973407cbb77bce7b96a062c40bLennart PoetteringAP_DECLARE(apr_status_t) ap_mpm_pod_signal(ap_pod_t *pod);
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * Write data to the pipe-of-death, signalling that all child process
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * @param p The pool to use when allocating any required structures.
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * @param num The number of child processes to kill
ee8c45689526ca973407cbb77bce7b96a062c40bLennart PoetteringAP_DECLARE(void) ap_mpm_pod_killpg(ap_pod_t *pod, int num);
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * These data members are common to all mpms. Each new mpm
3e3db0ee860025ad663b13b0ace4e6d627611332Lennart Poettering * should either use the appropriate ap_mpm_set_* function
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * in their command table or create their own for custom or
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering * OS specific needs. These should work for most.
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * The maximum number of requests each child thread or
6d0c65ffb4f82e8c6dceb453919b3db54343fc27Lennart Poettering * process handles before dying off
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poetteringconst char *ap_mpm_set_max_requests(cmd_parms *cmd, void *dummy,
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * The filename used to store the process id.
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poetteringextern const char *ap_pid_fname;
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poetteringconst char *ap_mpm_set_pidfile(cmd_parms *cmd, void *dummy,
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * The name of lockfile used when Apache needs to lock the accept() call.
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poetteringextern const char *ap_lock_fname;
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poetteringconst char *ap_mpm_set_lockfile(cmd_parms *cmd, void *dummy,
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * The system mutex implementation to use for the accept mutex.
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poetteringextern apr_lockmech_e ap_accept_lock_mech;
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poetteringconst char *ap_mpm_set_accept_lock_mech(cmd_parms *cmd, void *dummy,
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * Set the scorboard file.
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poetteringconst char *ap_mpm_set_scoreboard(cmd_parms *cmd, void *dummy,
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poettering * The directory that the server changes directory to dump core.
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poetteringextern char ap_coredump_dir[MAX_STRING_LEN];
ee8c45689526ca973407cbb77bce7b96a062c40bLennart Poetteringconst char *ap_mpm_set_coredumpdir(cmd_parms *cmd, void *dummy,
ab1525bc2d92780b4dc64bc5b9cdb52594e2df7dLennart Poettering * Set the timeout period for a graceful shutdown.
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart Poetteringconst char *ap_mpm_set_graceful_shutdown(cmd_parms *cmd, void *dummy,
373d9f173f910d547159917401c4b1f84af85736Tom Gundersen const char *arg);
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart PoetteringAP_INIT_TAKE1("GracefulShutdownTimeout", ap_mpm_set_graceful_shutdown, NULL, \
d57c365bf8f09fbcc649e00f7060ff30809f67c2Lennart Poettering RSRC_CONF, "Maximum time in seconds to wait for child " \
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart Poettering "processes to complete transactions during shutdown")
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart Poetteringint ap_signal_server(int *, apr_pool_t *);
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart Poetteringextern const char *ap_mpm_set_max_mem_free(cmd_parms *cmd, void *dummy,
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart Poetteringextern const char *ap_mpm_set_thread_stacksize(cmd_parms *cmd, void *dummy,
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart Poetteringextern apr_status_t ap_fatal_signal_setup(server_rec *s, apr_pool_t *pconf);
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart Poetteringextern apr_status_t ap_fatal_signal_child_setup(server_rec *s);
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart Poetteringextern const char *ap_mpm_set_exception_hook(cmd_parms *cmd, void *dummy,
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart PoetteringAP_DECLARE(pid_t) ap_mpm_get_child_pid(int childnum);
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart PoetteringAP_DECLARE(apr_status_t) ap_mpm_note_child_killed(int childnum);
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart Poettering/* register modules that undertake to manage system security */
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart PoetteringAP_DECLARE(int) ap_sys_privileges_handlers(int inc);
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart PoetteringAP_DECLARE_HOOK(int, drop_privileges, (apr_pool_t * pchild, server_rec * s))
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart Poettering/* pass control to the MPM */
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart PoetteringAP_DECLARE_HOOK(int, mpm, (apr_pool_t *pconf, apr_pool_t *plog, server_rec *s))
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart Poettering/* implement the mpm query function */
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart PoetteringAP_DECLARE_HOOK(apr_status_t, mpm_query, (int query_code, int *result))
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart Poettering/* get pid of child by index */
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart PoetteringAP_DECLARE_HOOK(pid_t, mpm_get_child_pid, (int childnum))
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart Poettering/* child specified by index has been killed */
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart PoetteringAP_DECLARE_HOOK(apr_status_t, mpm_note_child_killed, (int childnum))
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart Poettering/* register the specified callback */
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart PoetteringAP_DECLARE_HOOK(apr_status_t, mpm_register_timed_callback,
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart Poettering (apr_time_t t, ap_mpm_callback_fn_t *cbfn, void *baton))
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart Poettering/* get MPM name */
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart PoetteringAP_DECLARE_HOOK(const char *,mpm_get_name,(void))
9085f64a6694f2928c79fcce365edb1dca6937d4Lennart Poettering#endif /* !APACHE_MPM_COMMON_H */