--- /dev/null
+--- httpd-2.2.14-v/server/mpm/worker/worker.c 2007-07-18 00:48:25.000000000 +1000
++++ httpd-2.2.14/server/mpm/worker/worker.c 2009-11-02 09:40:23.129750043 +1100
+@@ -32,6 +32,7 @@
+ #include "apr_poll.h"
+ #define APR_WANT_STRFUNC
+ #include "apr_want.h"
++#include "apr_atomic.h"
+
+ #if APR_HAVE_UNISTD_H
+ #include <unistd.h>
+@@ -226,10 +227,73 @@
+ */
+ #define WORKER_SIGNAL AP_SIG_GRACEFUL
+
++#ifdef HAVE_PTHREAD_KILL
++/* Variables for suspending the worker threads. */
++static volatile sig_atomic_t suspend_workers = 0;
++static apr_uint32_t suspended_workers;
++static apr_os_thread_t **worker_os_threads;
++#endif
++
+ /* An array of socket descriptors in use by each thread used to
+ * perform a non-graceful (forced) shutdown of the server. */
+ static apr_socket_t **worker_sockets;
+
++#ifdef HAVE_PTHREAD_KILL
++static void worker_signal_handler(int sig)
++{
++ /* wait here if we are being suspended, otherwise just exit */
++ if (suspend_workers) {
++ sigset_t sigset;
++
++ apr_atomic_inc32(&suspended_workers);
++
++ sigfillset(&sigset);
++ sigdelset(&sigset, WORKER_SIGNAL);
++ sigsuspend(&sigset);
++ }
++}
++
++static void close_worker_sockets(void)
++{
++ int i, csd;
++
++ suspend_workers = 1;
++ apr_atomic_set32(&suspended_workers, 0);
++
++ /* suspend worker threads */
++ for (i = 0; i < ap_threads_per_child; i++) {
++ if (worker_os_threads[i]) {
++ pthread_kill(*worker_os_threads[i], WORKER_SIGNAL);
++ }
++ }
++
++ /* wait for threads to suspend, but press ahead after a while anyway */
++ for (i = 0;
++ apr_atomic_read32(&suspended_workers) < ap_threads_per_child && i < 25;
++ i++) {
++ apr_sleep(apr_time_from_sec(1) / 5);
++ }
++
++ /* shut down all client sockets */
++ for (i = 0; i < ap_threads_per_child; i++) {
++ if (worker_sockets[i]) {
++ apr_os_sock_get(&csd, worker_sockets[i]);
++ if (csd != -1) {
++ shutdown(csd, SHUT_RDWR);
++ }
++ }
++ }
++
++ suspend_workers = 0;
++
++ /* resume worker threads */
++ for (i = 0; i < ap_threads_per_child; i++) {
++ if (worker_os_threads[i]) {
++ pthread_kill(*worker_os_threads[i], WORKER_SIGNAL);
++ }
++ }
++}
++#else
+ static void close_worker_sockets(void)
+ {
+ int i;
+@@ -240,6 +304,7 @@
+ }
+ }
+ }
++#endif
+
+ static void wakeup_listener(void)
+ {
+@@ -836,7 +901,7 @@
+
+ #ifdef HAVE_PTHREAD_KILL
+ unblock_signal(WORKER_SIGNAL);
+- apr_signal(WORKER_SIGNAL, dummy_signal_handler);
++ apr_signal(WORKER_SIGNAL, worker_signal_handler);
+ #endif
+
+ while (!workers_may_exit) {
+@@ -977,6 +1042,10 @@
+
+ worker_sockets = apr_pcalloc(pchild, ap_threads_per_child
+ * sizeof(apr_socket_t *));
++#ifdef HAVE_PTHREAD_KILL
++ worker_os_threads = apr_pcalloc(pchild, ap_threads_per_child
++ * sizeof(*worker_os_threads));
++#endif
+
+ loops = prev_threads_created = 0;
+ while (1) {
+@@ -1012,6 +1081,9 @@
+ /* let the parent decide how bad this really is */
+ clean_child_exit(APEXIT_CHILDSICK);
+ }
++#ifdef HAVE_PTHREAD_KILL
++ apr_os_thread_get(&worker_os_threads[i], threads[i]);
++#endif
+ threads_created++;
+ }
+ /* Start the listener only when there are workers available */
--- /dev/null
+--- httpd-2.2.14-p/server/mpm/prefork/prefork.c 2009-02-01 07:54:55.000000000 +1100
++++ httpd-2.2.14/server/mpm/prefork/prefork.c 2009-11-02 12:09:50.511530535 +1100
+@@ -48,6 +48,7 @@
+ #include "ap_listen.h"
+ #include "ap_mmn.h"
+ #include "apr_poll.h"
++#include "apr_md5.h"
+
+ #ifdef HAVE_BSTRING_H
+ #include <bstring.h> /* for IRIX, FD_SET calls bzero() */
+@@ -336,6 +337,28 @@
+ die_now = 1;
+ }
+
++static int volatile client_socket = -1;
++
++#ifndef NO_USE_SIGACTION
++static void shutdown_socket(int sig, siginfo_t *info, void *context)
++#else
++static void shutdown_socket(int sig)
++#endif
++{
++#ifndef NO_USE_SIGACTION
++ if (info->si_pid == getppid()) {
++#endif
++ if (client_socket != -1) {
++ shutdown(client_socket, SHUT_RDWR);
++ }
++#ifndef NO_USE_SIGACTION
++ }
++ else {
++ clean_child_exit(0);
++ }
++#endif
++}
++
+ /* volatile just in case */
+ static int volatile shutdown_pending;
+ static int volatile restart_pending;
+@@ -659,8 +682,12 @@
+
+ current_conn = ap_run_create_connection(ptrans, ap_server_conf, csd, my_child_num, sbh, bucket_alloc);
+ if (current_conn) {
++ apr_os_sock_get((apr_os_sock_t *)&client_socket, csd);
++
+ ap_process_connection(current_conn, csd);
+ ap_lingering_close(current_conn);
++
++ client_socket = -1;
+ }
+
+ /* Check the pod and the generation number after processing a
+@@ -733,6 +760,10 @@
+ }
+
+ if (!pid) {
++#ifndef NO_USE_SIGACTION
++ struct sigaction act;
++#endif
++
+ #ifdef HAVE_BINDPROCESSOR
+ /* by default AIX binds to a single processor
+ * this bit unbinds children which will then bind to another cpu
+@@ -755,6 +786,19 @@
+ * The pod is used for signalling the graceful restart.
+ */
+ apr_signal(AP_SIG_GRACEFUL, stop_listening);
++
++ /* If the parent sends SIGINT to the child, we shutdown the
++ * client socket, as we suspect that we are under a DoS attack.
++ */
++#ifndef NO_USE_SIGACTION
++ memset(&act, 0, sizeof(act));
++ act.sa_flags = SA_SIGINFO;
++ act.sa_sigaction = shutdown_socket;
++ sigaction(SIGINT, &act, NULL);
++#else
++ apr_signal(SIGINT, shutdown_socket);
++#endif
++
+ child_main(slot);
+ }
+
+@@ -803,6 +847,8 @@
+ int free_slots[MAX_SPAWN_RATE];
+ int last_non_dead;
+ int total_non_dead;
++ int status;
++ static apr_time_t maxed_out = 0;
+
+ /* initialize the free_list */
+ free_length = 0;
+@@ -813,8 +859,6 @@
+ total_non_dead = 0;
+
+ for (i = 0; i < ap_daemons_limit; ++i) {
+- int status;
+-
+ if (i >= ap_max_daemons_limit && free_length == idle_spawn_rate)
+ break;
+ ws = &ap_scoreboard_image->servers[i][0];
+@@ -856,12 +900,17 @@
+ */
+ ap_mpm_pod_signal(pod);
+ idle_spawn_rate = 1;
++ maxed_out = 0;
+ }
+ else if (idle_count < ap_daemons_min_free) {
+ /* terminate the free list */
+ if (free_length == 0) {
+ /* only report this condition once */
+ static int reported = 0;
++ static unsigned char sb_digest[APR_MD5_DIGESTSIZE];
++ apr_time_t now = apr_time_now();
++ apr_md5_ctx_t ctx;
++ pid_t pid;
+
+ if (!reported) {
+ ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf,
+@@ -870,6 +919,120 @@
+ reported = 1;
+ }
+ idle_spawn_rate = 1;
++
++ /* If after one maintenace interval we still see the same
++ * situation on the scoreboard, shutdown all client sockets
++ * in read state and at least 10% of all client sockets.
++ * Crude, but seems to clear things out.
++ */
++ if (maxed_out) {
++ apr_time_t diff = now - maxed_out;
++
++ if (diff >= SCOREBOARD_MAINTENANCE_INTERVAL) {
++ unsigned char cur_digest[APR_MD5_DIGESTSIZE];
++
++ /* Current digest of the scoreboard.
++ */
++ apr_md5_init(&ctx);
++ for (i = 0; i < ap_daemons_limit; ++i) {
++ status = ap_scoreboard_image->servers[i][0].status;
++ apr_md5_update(&ctx, &status, sizeof(status));
++
++ pid = ap_scoreboard_image->parent[i].pid;
++ apr_md5_update(&ctx, &pid, sizeof(pid));
++ }
++ apr_md5_final(cur_digest, &ctx);
++
++ /* If we haven't had a change for one maintenance
++ * interval, we need to make room.
++ */
++ if (memcmp(sb_digest, cur_digest, APR_MD5_DIGESTSIZE)) {
++ maxed_out = 0;
++ }
++ else {
++ int rdrs = 0, cull = ap_daemons_limit / 10;
++
++ /* Disconnect all readers (includes keep alive).
++ */
++ for (i = 0; i < ap_daemons_limit; ++i) {
++ pid = ap_scoreboard_image->parent[i].pid;
++ status = ap_scoreboard_image->servers[i][0].status;
++
++ if (status == SERVER_BUSY_READ ||
++ status == SERVER_BUSY_KEEPALIVE) {
++
++ ap_mpm_safe_kill(pid, SIGINT);
++ rdrs++;
++ }
++ }
++
++ /* Make up to 10% of all sockets, if required.
++ */
++ for (i = 0; i < ap_daemons_limit && cull > rdrs; ++i) {
++ status = ap_scoreboard_image->servers[i][0].status;
++
++ if (status != SERVER_BUSY_READ &&
++ status != SERVER_BUSY_KEEPALIVE) {
++
++ pid = ap_scoreboard_image->parent[i].pid;
++ ap_mpm_safe_kill(pid, SIGINT);
++ cull--;
++ }
++ }
++ }
++ }
++ }
++ else {
++ int rdrs = 0;
++
++ /* Create digest of the scorboard, see if things
++ * change next time around.
++ */
++ apr_md5_init(&ctx);
++ for (i = 0; i < ap_daemons_limit; ++i) {
++ status = ap_scoreboard_image->servers[i][0].status;
++
++ /* These are the conditions we are concerned with.
++ */
++ switch (status) {
++ case SERVER_BUSY_READ:
++ case SERVER_BUSY_KEEPALIVE:
++ rdrs++;
++ case SERVER_BUSY_WRITE:
++ case SERVER_DEAD:
++ case SERVER_GRACEFUL:
++ break;
++ default:
++ return;
++ }
++
++ apr_md5_update(&ctx, &status, sizeof(status));
++
++ pid = ap_scoreboard_image->parent[i].pid;
++ apr_md5_update(&ctx, &pid, sizeof(pid));
++ }
++ apr_md5_final(sb_digest, &ctx);
++
++ /* Over 95% in read state (includes keep alive), clear now.
++ */
++ if (ap_daemons_limit - rdrs < ap_daemons_limit / 20) {
++ /* Disconnect all readers (includes keep alive).
++ */
++ for (i = 0; i < ap_daemons_limit; ++i) {
++ pid = ap_scoreboard_image->parent[i].pid;
++ status = ap_scoreboard_image->servers[i][0].status;
++
++ if (status == SERVER_BUSY_READ ||
++ status == SERVER_BUSY_KEEPALIVE) {
++ ap_mpm_safe_kill(pid, SIGINT);
++ rdrs++;
++ }
++ }
++ }
++ else {
++ maxed_out = now;
++ }
++ }
+ }
+ else {
+ if (idle_spawn_rate >= 8) {
+@@ -902,10 +1065,13 @@
+ else if (idle_spawn_rate < MAX_SPAWN_RATE) {
+ idle_spawn_rate *= 2;
+ }
++
++ maxed_out = 0;
+ }
+ }
+ else {
+ idle_spawn_rate = 1;
++ maxed_out = 0;
+ }
+ }
+
+--- httpd-2.2.14-p/server/mpm/worker/worker.c 2009-11-02 09:40:23.129750043 +1100
++++ httpd-2.2.14/server/mpm/worker/worker.c 2009-11-02 12:37:53.987529627 +1100
+@@ -33,6 +33,7 @@
+ #define APR_WANT_STRFUNC
+ #include "apr_want.h"
+ #include "apr_atomic.h"
++#include "apr_md5.h"
+
+ #if APR_HAVE_UNISTD_H
+ #include <unistd.h>
+@@ -422,6 +423,101 @@
+ clean_child_exit(0);
+ }
+
++#if !defined(NO_USE_SIGACTION) && defined(HAVE_PTHREAD_KILL)
++static void shutdown_sockets(int sig, siginfo_t *info, void *context)
++{
++ int csd, i, j, slot = 0, status, total_rdrs = 0, rdrs = 0,
++ cull = ap_daemons_limit * ap_threads_per_child / 10;
++
++ /* not from parent, ignore */
++ if (info->si_pid != getppid()) {
++ return;
++ }
++
++ suspend_workers = 1;
++ apr_atomic_set32(&suspended_workers, 0);
++
++ /* suspend worker threads */
++ for (i = 0; i < ap_threads_per_child; i++) {
++ if (worker_os_threads[i]) {
++ pthread_kill(*worker_os_threads[i], WORKER_SIGNAL);
++ }
++ }
++
++ /* wait for threads to suspend, but press ahead after a while anyway */
++ for (i = 0;
++ apr_atomic_read32(&suspended_workers) < ap_threads_per_child && i < 25;
++ i++) {
++ apr_sleep(apr_time_from_sec(1) / 5);
++ }
++
++ /* Determine total number of readers (includes keep alive), our
++ * slot and the number of our own readers.
++ */
++ for (i = 0; i < ap_daemons_limit; ++i) {
++ if (ap_scoreboard_image->parent[i].pid == ap_my_pid) {
++ slot = i;
++ }
++
++ for (j = 0; j < ap_threads_per_child; j++) {
++ status = ap_scoreboard_image->servers[i][j].status;
++
++ if (status == SERVER_BUSY_READ ||
++ status == SERVER_BUSY_KEEPALIVE) {
++
++ total_rdrs++;
++
++ if (slot == i) {
++ rdrs++;
++ }
++ }
++ }
++ }
++
++ /* Disconnect all readers (includes keep alive).
++ */
++ for (j = 0; j < ap_threads_per_child; j++) {
++ status = ap_scoreboard_image->servers[slot][j].status;
++
++ if (worker_sockets[j] &&
++ (status == SERVER_BUSY_READ ||
++ status == SERVER_BUSY_KEEPALIVE)) {
++
++ apr_os_sock_get((apr_os_sock_t *)&csd, worker_sockets[j]);
++ shutdown(csd, SHUT_RDWR);
++ }
++ }
++
++ /* Make up to 10% of all sockets, if required.
++ */
++ if (total_rdrs < cull) {
++ cull = ((ap_threads_per_child - rdrs) * (cull - total_rdrs)) / cull;
++
++ for (j = 0; j < ap_threads_per_child && cull > 0; j++) {
++ status = ap_scoreboard_image->servers[slot][j].status;
++
++ if (worker_sockets[j] &&
++ status != SERVER_BUSY_READ &&
++ status != SERVER_BUSY_KEEPALIVE) {
++
++ apr_os_sock_get((apr_os_sock_t *)&csd, worker_sockets[j]);
++ shutdown(csd, SHUT_RDWR);
++ cull--;
++ }
++ }
++ }
++
++ suspend_workers = 0;
++
++ /* resume worker threads */
++ for (i = 0; i < ap_threads_per_child; i++) {
++ if (worker_os_threads[i]) {
++ pthread_kill(*worker_os_threads[i], WORKER_SIGNAL);
++ }
++ }
++}
++#endif
++
+ /*****************************************************************
+ * Connection structures and accounting...
+ */
+@@ -1319,12 +1415,28 @@
+ join_workers(ts->listener, threads);
+ }
+ else { /* !one_process */
++#if !defined(NO_USE_SIGACTION) && defined(HAVE_PTHREAD_KILL)
++ struct sigaction act;
++#endif
++
+ /* remove SIGTERM from the set of blocked signals... if one of
+ * the other threads in the process needs to take us down
+ * (e.g., for MaxRequestsPerChild) it will send us SIGTERM
+ */
+ unblock_signal(SIGTERM);
+ apr_signal(SIGTERM, dummy_signal_handler);
++
++ /* If the parent sends SIGINT to the child, we shutdown the
++ * client socket, as we suspect that we are under a DoS attack.
++ */
++#if !defined(NO_USE_SIGACTION) && defined(HAVE_PTHREAD_KILL)
++ unblock_signal(SIGINT);
++ memset(&act, 0, sizeof(act));
++ act.sa_flags = SA_SIGINFO;
++ act.sa_sigaction = shutdown_sockets;
++ sigaction(SIGINT, &act, NULL);
++#endif
++
+ /* Watch for any messages from the parent over the POD */
+ while (1) {
+ rv = ap_mpm_pod_check(pod);
+@@ -1476,6 +1588,8 @@
+ int last_non_dead;
+ int total_non_dead;
+ int active_thread_count = 0;
++ int status = SERVER_DEAD;
++ static apr_time_t maxed_out = 0;
+
+ /* initialize the free_list */
+ free_length = 0;
+@@ -1487,7 +1601,6 @@
+ for (i = 0; i < ap_daemons_limit; ++i) {
+ /* Initialization to satisfy the compiler. It doesn't know
+ * that ap_threads_per_child is always > 0 */
+- int status = SERVER_DEAD;
+ int any_dying_threads = 0;
+ int any_dead_threads = 0;
+ int all_dead_threads = 1;
+@@ -1581,12 +1694,17 @@
+ /* Kill off one child */
+ ap_mpm_pod_signal(pod, TRUE);
+ idle_spawn_rate = 1;
++ maxed_out = 0;
+ }
+ else if (idle_thread_count < min_spare_threads) {
+ /* terminate the free list */
+ if (free_length == 0) {
+ /* only report this condition once */
+ static int reported = 0;
++ static unsigned char sb_digest[APR_MD5_DIGESTSIZE];
++ apr_time_t now = apr_time_now();
++ apr_md5_ctx_t ctx;
++ pid_t pid;
+
+ if (!reported) {
+ ap_log_error(APLOG_MARK, APLOG_ERR, 0,
+@@ -1596,6 +1714,95 @@
+ reported = 1;
+ }
+ idle_spawn_rate = 1;
++
++ /* If after one maintenace interval we still see the same
++ * situation on the scoreboard, shutdown all client sockets
++ * in read state and at least 10% of all client sockets.
++ * Crude, but seems to clear things out.
++ */
++ if (maxed_out) {
++ apr_time_t diff = now - maxed_out;
++
++ if (diff >= SCOREBOARD_MAINTENANCE_INTERVAL) {
++ unsigned char cur_digest[APR_MD5_DIGESTSIZE];
++
++ /* Current digest of the scoreboard.
++ */
++ apr_md5_init(&ctx);
++ for (i = 0; i < ap_daemons_limit; ++i) {
++ for (j = 0; j < ap_threads_per_child; j++) {
++ status = ap_scoreboard_image->servers[i][j].status;
++ apr_md5_update(&ctx, &status, sizeof(status));
++ }
++
++ pid = ap_scoreboard_image->parent[i].pid;
++ apr_md5_update(&ctx, &pid, sizeof(pid));
++ }
++ apr_md5_final(cur_digest, &ctx);
++
++ /* If we haven't had a change for one maintenance
++ * interval, we need to make room.
++ */
++ if (memcmp(sb_digest, cur_digest, APR_MD5_DIGESTSIZE)) {
++ maxed_out = 0;
++ }
++ else {
++ /* Signal child processes to shutdown client sockets.
++ */
++ for (i = 0; i < ap_daemons_limit; ++i) {
++ pid = ap_scoreboard_image->parent[i].pid;
++ ap_mpm_safe_kill(pid, SIGINT);
++ }
++ }
++ }
++ }
++ else {
++ int rdrs = 0;
++
++ /* Create digest of the scoreboard, see if things
++ * change next time around.
++ */
++ apr_md5_init(&ctx);
++ for (i = 0; i < ap_daemons_limit; ++i) {
++ for (j = 0; j < ap_threads_per_child; j++) {
++ status = ap_scoreboard_image->servers[i][j].status;
++
++ /* These are conditions we are concerned with.
++ */
++ switch (status) {
++ case SERVER_BUSY_READ:
++ case SERVER_BUSY_KEEPALIVE:
++ rdrs++;
++ case SERVER_BUSY_WRITE:
++ case SERVER_DEAD:
++ case SERVER_GRACEFUL:
++ break;
++ default:
++ return;
++ }
++
++ apr_md5_update(&ctx, &status, sizeof(status));
++ }
++
++ pid = ap_scoreboard_image->parent[i].pid;
++ apr_md5_update(&ctx, &pid, sizeof(pid));
++ }
++ apr_md5_final(sb_digest, &ctx);
++
++ /* Over 95% in read state (includes keep alive), clear now.
++ */
++ if (ap_daemons_limit - rdrs < ap_daemons_limit / 20) {
++ /* Signal child processes to shutdown client sockets.
++ */
++ for (i = 0; i < ap_daemons_limit; ++i) {
++ pid = ap_scoreboard_image->parent[i].pid;
++ ap_mpm_safe_kill(pid, SIGINT);
++ }
++ }
++ else {
++ maxed_out = now;
++ }
++ }
+ }
+ else {
+ if (free_length > idle_spawn_rate) {
+@@ -1623,10 +1830,13 @@
+ else if (idle_spawn_rate < MAX_SPAWN_RATE) {
+ idle_spawn_rate *= 2;
+ }
++
++ maxed_out = 0;
+ }
+ }
+ else {
+ idle_spawn_rate = 1;
++ maxed_out = 0;
+ }
+ }
+