Basic support for spawning children porcesses via fork() and killing them with kill(). (75d3f1a2) · Commits · CYBER - Cyber Security / TS 103 523 MSP / TLMSP / TLMSP Apache Httpd

server/mpm/simple/simple_children.c

+69 −5

Changes for server/mpm/simple/simple_children.c: 69 added lines, 5 removed lines.
Original line number	Diff line number	Diff line
		@@ -19,34 +19,97 @@
		#include "simple_types.h"
		#include "simple_event.h"
		#include "simple_run.h"
		#include "http_log.h"
		#include "simple_children.h"
		#include "apr_hash.h"

		#include <unistd.h> /* For fork() */

		#define SPAWN_CHILDREN_INTERVAL (apr_time_from_sec(5))

		static void simple_kill_random_child(simple_core_t * sc)
		{
		apr_thread_mutex_lock(sc->mtx);
		/* See comment in simple_spawn_child for why we check here. */
		if (!sc->run_single_process) {
		apr_hash_index_t *hi;
		simple_child_t *child = NULL;

		apr_thread_mutex_lock(sc->mtx);
		hi = apr_hash_first(sc->pool, sc->children);
		if (hi != NULL) {
		apr_hash_this(hi, NULL, NULL, (void **)&child);
		apr_hash_set(sc->children, &child->pid, sizeof(child->pid), NULL);
		}
		apr_thread_mutex_unlock(sc->mtx);

		if (child != NULL) {
		kill(child->pid, 9);
		/* TODO: recycle child object */
		}
		}
		}

		static void simple_spawn_child(simple_core_t * sc)
		static void clean_child_exit(int code) __attribute__ ((noreturn));
		static void clean_child_exit(int code)
		{
		apr_thread_mutex_lock(sc->mtx);
		/* TODO: Pool cleanups.... sigh. */
		exit(code);
		}

		static int simple_spawn_child(simple_core_t * sc)
		{
		pid_t pid = 0;
		int rv = 0;
		/* Although we could cut this off 'earlier', and not even invoke this
		* function, I would like to keep the functions invoked when in debug mode
		* to be as close as possible to those when not in debug... So, we just skip
		* the actual spawn itself, but go through all of the motions...
		*/
		if (!sc->run_single_process) {
		if (sc->spawn_via == SIMPLE_SPAWN_FORK) {

		pid = fork();
		if (pid == -1) {
		rv = errno;
		ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL,
		"simple_spawn_child: Unable to fork new process");
		return rv;
		}

		if (pid == 0) {
		/* this is the child process */

		rv = simple_child_loop(sc);

		if (rv) {
		clean_child_exit(APEXIT_CHILDFATAL);
		}
		else {
		clean_child_exit(0);
		}
		}
		}
		else {
		/* TODO: SIMPLE_SPAWN_EXEC */
		abort();
		}
		}

		if (pid != 0) {
		simple_child_t *child;

		apr_thread_mutex_lock(sc->mtx);

		child = apr_palloc(sc->pool, sizeof(simple_child_t));
		child->pid = pid;
		apr_hash_set(sc->children, &child->pid, sizeof(child->pid), child);

		apr_thread_mutex_unlock(sc->mtx);
		}

		return 0;
		}

		void simple_check_children_size(simple_core_t * sc, void *baton)
		{
		unsigned int count;
		@@ -83,10 +146,11 @@ void simple_check_children_size(simple_core_t * sc, void *baton)
		}
		}
		else if (count < wanted) {
		int rv = 0;
		/* spawn some kids */
		int to_spawn = wanted - count;
		for (i = 0; i < to_spawn; i++) {
		simple_spawn_child(sc);
		for (i = 0; rv == 0 && i < to_spawn; i++) {
		rv = simple_spawn_child(sc);
		}
		}
		else {

server/mpm/simple/simple_core.c

+2 −0

Changes for server/mpm/simple/simple_core.c: 2 added lines, 0 removed lines.
Original line number	Diff line number	Diff line
		@@ -49,6 +49,8 @@ apr_status_t simple_core_init(simple_core_t * sc, apr_pool_t * pool)
		sc->procmgr.max_requests_per_child = DEFAULT_MAX_REQUESTS_PER_CHILD;

		sc->children = apr_hash_make(sc->pool);
		/* TODO: configurable spawning mech */
		sc->spawn_via = SIMPLE_SPAWN_FORK;

		APR_RING_INIT(&sc->timer_ring, simple_timer_t, link);
		APR_RING_INIT(&sc->dead_timer_ring, simple_timer_t, link);

server/mpm/simple/simple_run.c

+1 −0

Changes for server/mpm/simple/simple_run.c: 1 added line, 0 removed lines.
Original line number	Diff line number	Diff line
		@@ -138,6 +138,7 @@ static void simple_timer_invoke(apr_thread_t thread, void *baton)
		ep->cb(sc, ep->baton);

		apr_thread_mutex_lock(sc->mtx);
		APR_RING_ELEM_INIT(ep, link);
		APR_RING_INSERT_TAIL(&sc->dead_timer_ring, ep, simple_timer_t, link);
		apr_thread_mutex_unlock(sc->mtx);

server/mpm/simple/simple_types.h

+14 −5

Changes for server/mpm/simple/simple_types.h: 14 added lines, 5 removed lines.
Original line number	Diff line number	Diff line
		@@ -35,11 +35,6 @@ typedef struct
		int max_requests_per_child;
		} simple_proc_mgr_t;

		typedef struct
		{
		int pid;
		} simple_child_t;

		typedef void (simple_timer_cb) (simple_core_t sc, void *baton);
		typedef void (simple_io_sock_cb) (simple_core_t sc, apr_socket_t * sock,
		int flags, void *baton);
		@@ -56,6 +51,12 @@ typedef enum
		SIMPLE_PT_USER
		} simple_poll_type_e;

		typedef enum
		{
		SIMPLE_SPAWN_FORK,
		SIMPLE_SPAWN_EXEC,
		} simple_spawn_type_e;

		struct simple_sb_t
		{
		simple_poll_type_e type;
		@@ -71,6 +72,13 @@ struct simple_timer_t
		void *baton;
		};

		typedef struct simple_child_t simple_child_t;
		struct simple_child_t
		{
		/* TODO: More is needed here. */
		pid_t pid;
		};

		struct simple_core_t
		{
		apr_pool_t *pool;
		@@ -81,6 +89,7 @@ struct simple_core_t

		int run_single_process;
		int run_foreground;
		simple_spawn_type_e spawn_via;

		simple_proc_mgr_t procmgr;