From 8ab979d28fb3fa23ea4aeeb1841e52ba77c1f0d3 Mon Sep 17 00:00:00 2001
From: Jeff Trawick <trawick@apache.org>
Date: Thu, 19 Feb 2004 11:19:43 +0000
Subject: [PATCH] Add a new directive EnableExceptionHook that must be
 specified for exception hooks to be called (in addition to the build time
 requirements).

The 2.1-dev feature is now more aligned with the 1.3.30-dev feature,
in that there is a build-time requirement as well as a configuration
requirement.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@102686 13f79535-47bb-0310-9956-ffa450edef68
---
 CHANGES              |  7 ++++---
 include/mpm_common.h |  5 +++++
 server/core.c        |  4 ++++
 server/mpm_common.c  | 31 ++++++++++++++++++++++++++++++-
 4 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/CHANGES b/CHANGES
index 08ac9f1eaf..efec25930d 100644
--- a/CHANGES
+++ b/CHANGES
@@ -97,9 +97,10 @@ Changes with Apache 2.1.0-dev
      directory, display the MPM name and some MPM properties.
      [Geoffrey Young <geoff apache.org>]
 
-  *) Add fatal exception hook for use by debug modules.  The hook is only
-     available if the --enable-exception-hook configure parm is used.
-     [Jeff Trawick]
+  *) Add fatal exception hook for use by diagnostic modules.  The hook
+     is only available if the --enable-exception-hook configure parm 
+     is used and the EnableExceptionHook directive has been set to 
+     "on".  [Jeff Trawick]
 
   *) mod_ssl/mod_status: Re-enable support for output of SSL session
      cache information in server-status page.  [Joe Orton]
diff --git a/include/mpm_common.h b/include/mpm_common.h
index 4636df5db1..13d7afd9bb 100644
--- a/include/mpm_common.h
+++ b/include/mpm_common.h
@@ -254,6 +254,11 @@ extern apr_status_t ap_fatal_signal_setup(server_rec *s, apr_pool_t *pconf);
 extern apr_status_t ap_fatal_signal_child_setup(server_rec *s);
 #endif
 
+#if AP_ENABLE_EXCEPTION_HOOK
+extern const char *ap_mpm_set_exception_hook(cmd_parms *cmd, void *dummy,
+                                             const char *arg);
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/server/core.c b/server/core.c
index 826e5fe2db..2bd91f1355 100644
--- a/server/core.c
+++ b/server/core.c
@@ -3231,6 +3231,10 @@ AP_INIT_TAKE1("AcceptMutex", ap_mpm_set_accept_lock_mech, NULL, RSRC_CONF,
 AP_INIT_TAKE1("MaxMemFree", ap_mpm_set_max_mem_free, NULL, RSRC_CONF,
               "Maximum number of 1k blocks a particular childs allocator may hold."),
 #endif
+#if AP_ENABLE_EXCEPTION_HOOK
+AP_INIT_TAKE1("EnableExceptionHook", ap_mpm_set_exception_hook, NULL, RSRC_CONF,
+              "Controls whether exception hook may be called after a crash"),
+#endif
 { NULL }
 };
 
diff --git a/server/mpm_common.c b/server/mpm_common.c
index 5ccbaff4e5..d814984b5a 100644
--- a/server/mpm_common.c
+++ b/server/mpm_common.c
@@ -879,6 +879,34 @@ static pid_t parent_pid, my_pid;
 apr_pool_t *pconf;
 
 #if AP_ENABLE_EXCEPTION_HOOK
+
+static int exception_hook_enabled;
+
+const char *ap_mpm_set_exception_hook(cmd_parms *cmd, void *dummy,
+                                      const char *arg)
+{
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+    if (err != NULL) {
+        return err;
+    }
+
+    if (cmd->server->is_virtual) {
+	return "EnableExceptionHook directive not allowed in <VirtualHost>";
+    }
+
+    if (strcasecmp(arg, "on") == 0) {
+        exception_hook_enabled = 1;
+    }
+    else if (strcasecmp(arg, "off") == 0) {
+        exception_hook_enabled = 0;
+    }
+    else {
+        return "parameter must be 'on' or 'off'";
+    }
+
+    return NULL;
+}
+
 APR_HOOK_STRUCT(
     APR_HOOK_LINK(fatal_exception)
 )
@@ -890,7 +918,8 @@ static void run_fatal_exception_hook(int sig)
 {
     ap_exception_info_t ei = {0};
 
-    if (geteuid() != 0 && 
+    if (exception_hook_enabled &&
+        geteuid() != 0 && 
         my_pid != parent_pid) {
         ei.sig = sig;
         ei.pid = my_pid;
-- 
2.50.1