Date: Fri, 15 Aug 1997 10:52:28 -0400
From: coar@decus.org (Rodent of Unusual Size)
Subject: [PATCH] Disabling logging based on envariable
To: New-HTTPd@apache.org, Coar@decus.org
Message-id: <97081510522863@decus.org>
Content-transfer-encoding: 7BIT
Sender: new-httpd-owner@apache.org
Precedence: bulk
Reply-To: new-httpd@apache.org

    A while ago I suggested that we rm mod_log_agent and
    mod_log_referer, but Rob pointed out that the latter had
    functionality that mod_log_config lacked: the ability to selectively
    *not* log based upon the value of the Referer header field.

    Okey, here's a patch to mod_log_config that addresses that and a
    whole lot more.  It adds the "DoNotLogIf" directive, with the syntax

     DoNotLogIf env=some_envariable

    (I'm not happy with the directive name; suggestions welcome.)

    Combined with mod_setenvif, I think this is a *major* enhancement to
    the ability to tailor logging.

    Works for me.. anyone see problems before I commit to 1.3 in 48
    hours?  (lazy voting rules)

    #ken    :-)}

Index: mod_log_config.c
===================================================================
RCS file: /export/home/cvs/apachen/src/modules/standard/mod_log_config.c,v
retrieving revision 1.34
diff -u -r1.34 mod_log_config.c
--- mod_log_config.c	1997/07/28 18:23:01	1.34
+++ mod_log_config.c	1997/08/15 14:48:03
@@ -192,6 +192,7 @@
   array_header *default_format;
   array_header *config_logs;    
   array_header *server_config_logs;
+  array_header *disabling_envs;
 } multi_log_state;
 
 /*
@@ -209,6 +210,13 @@
 } config_log_state;
 
 /*
+ * Incredibly simple record for remembering the name of an envariable.
+ */
+typedef struct {
+    char *name;
+} env_rec;
+
+/*
  * Format items...
  */
 
@@ -568,6 +576,19 @@
     config_log_state *clsarray;
     int i;
 
+    /*
+     * First things first.  Walk through the array of envariables whose
+     * existence disable logging.  If we find one in the request's envariable
+     * array, we just leave quietly.
+     */
+    if (mls->disabling_envs != NULL) {
+	env_rec *envar = (env_rec *)mls->disabling_envs->elts;
+	for (i = 0; i < mls->disabling_envs->nelts; ++i) {
+	    if (table_get (r->subprocess_env, (char *)envar[i].name) != NULL) {
+		return OK;
+	    }
+	}
+    }
     if (mls->config_logs->nelts) {
         clsarray = (config_log_state *)mls->config_logs->elts;
         for (i = 0; i < mls->config_logs->nelts; ++i) {
@@ -602,6 +623,7 @@
 	make_array(p, 5, sizeof (config_log_state));
     mls->default_format = NULL;
     mls->server_config_logs = NULL;
+    mls->disabling_envs = NULL;
     
     return mls;
 }
@@ -617,8 +639,9 @@
     multi_log_state *add = (multi_log_state *)addv;
     
     add->server_config_logs = base->config_logs;
-    if (!add->default_format)
+    if (!add->default_format) {
         add->default_format = base->default_format;
+    }
     
     return add;
 }
@@ -661,6 +684,29 @@
     return add_custom_log(cmd, dummy, fn, "%{Cookie}n \"%r\" %t");
 }
 
+/*
+ * Make a note of an environment variable condition which will prevent
+ * logging.
+ */
+static const char *note_disabling_env(cmd_parms *cmd, void *mcfg, char *cond)
+{
+    multi_log_state *mls =
+	(multi_log_state *)get_module_config(cmd->server->module_config,
+                                             &config_log_module);
+    env_rec *envar;
+
+    if (strncasecmp(cond, "env=", 4)) {
+	return pstrcat(cmd->pool, "Bad argument \"", cond, "\" to ",
+		       cmd->cmd->name, NULL);
+    }
+    if (mls->disabling_envs == NULL) {
+	mls->disabling_envs = make_array(cmd->pool, 4, sizeof(env_rec));
+    }
+    envar = push_array(mls->disabling_envs);
+    envar->name = pstrdup(cmd->pool, &cond[4]);
+    return NULL;
+}
+
 static command_rec config_log_cmds[] = {
 { "CustomLog", add_custom_log, NULL, RSRC_CONF, TAKE2,
     "a file name and a custom log format string" },
@@ -670,6 +716,8 @@
     "a log format string (see docs)" },
 { "CookieLog", set_cookie_log, NULL, RSRC_CONF, TAKE1,
     "the filename of the cookie log" },
+{ "DoNotLogIf", note_disabling_env, NULL, RSRC_CONF, TAKE1,
+    "\"env=name\"" },
 { NULL }
 };
 
@@ -791,5 +839,5 @@
    multi_log_transaction,	/* logger */
    NULL,			/* header parser */
    NULL,			/* child_init */
-   NULL			/* child_exit */
+   NULL				/* child_exit */
 };