Add a bit of infrastructure which will be needed for input filtering:

1) separate filter lists hanging off the r and the c

   requests start off with the same filter list as the connection

   the input filter list is not initialized for subrequests

   internal redirects start off with the same filter list as the
   connection

2) AddInputFilter directive (blatant rip-off of Ryan's AddOutputFilter
   directive); as with AddOutputFilter, the network is implicitly to the
   right of the specified filter list; this may not be the most
   intuitive way to specify the filters; not sure yet


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@86403 13f79535-47bb-0310-9956-ffa450edef68

include/http_core.h

@@ -423,6 +423,7 @@ typedef struct {
 #endif    
 
     apr_array_header_t *filters;
+    apr_array_header_t *input_filters;
 } core_dir_config;
 
 /* Per-server core configuration */

include/httpd.h

@@ -806,8 +806,11 @@ struct request_rec {
 #endif /*APACHE_XLATE*/
 
     /** A list of output filters to be used for this request 
-     *  @defvar ap_filter_t *filters */
+     *  @defvar ap_filter_t *output_filters */
     struct ap_filter_t *output_filters;
+    /** A list of input filters to be used for this request 
+     *  @defvar ap_filter_t *filters */
+    struct ap_filter_t *input_filters;
     /** A flag to determine if the eos bucket has been sent yet
      *  @defvar int eos_sent */
     int eos_sent;

include/util_filter.h

@@ -320,10 +320,11 @@ API_EXPORT(void) ap_register_output_filter(const char *name,
  * Add a filter to the current connection.  Filters are added in a FIFO manner.
  * The first filter added will be the first filter called.
  * @param name The name of the filter to add
+ * @param r The request to add this filter for (or NULL if it isn't associated with a request)
  * @param c The connection to add the fillter for
- * @deffunc void ap_add_input_filter(const char *name, void *ctx, conn_rec *r)
+ * @deffunc void ap_add_input_filter(const char *name, void *ctx, request_rec *r, conn_rec *c)
  */
-API_EXPORT(void) ap_add_input_filter(const char *name, void *ctx, conn_rec *r);
+API_EXPORT(void) ap_add_input_filter(const char *name, void *ctx, request_rec *r, conn_rec *c);
 
 /**
  * Add a filter to the current request.  Filters are added in a FIFO manner.

modules/http/http_core.c

@@ -187,6 +187,7 @@ static void *create_core_dir_config(apr_pool_t *a, char *dir)
     conf->add_default_charset_name = DEFAULT_ADD_DEFAULT_CHARSET_NAME;
 
     conf->filters = apr_make_array(a, 2, sizeof(void *));
+    conf->input_filters = apr_make_array(a, 2, sizeof(void *));
     return (void *)conf;
 }
 
@@ -327,6 +328,8 @@ static void *merge_core_dir_configs(apr_pool_t *a, void *basev, void *newv)
 	}
     }
     conf->filters = apr_append_arrays(a, base->filters, new->filters);
+    conf->input_filters = apr_append_arrays(a, base->input_filters,
+                                            new->input_filters);
 
     return (void*)conf;
 }
@@ -1884,6 +1887,16 @@ static const char *add_filter(cmd_parms *cmd, void *dummy, const char *arg)
     return NULL;
 }
 
+static const char *add_input_filter(cmd_parms *cmd, void *dummy, const char *arg)
+{
+    core_dir_config *conf = dummy;
+    char **newfilter;
+    
+    newfilter = (char **)apr_push_array(conf->input_filters);
+    *newfilter = apr_pstrdup(cmd->pool, arg);
+    return NULL;
+}
+
 static const char *add_module_command(cmd_parms *cmd, void *dummy,
 				      const char *arg)
 {
@@ -2765,13 +2778,15 @@ AP_INIT_TAKE12("RLimitNPROC", set_limit_nproc,
 AP_INIT_TAKE12("RLimitNPROC", no_set_limit, NULL,
    OR_ALL, "soft/hard limits for max number of processes per uid"),
 #endif
-/* XXX This should be allowable in .htaccess files, but currently it won't
+/* XXX These should be allowable in .htaccess files, but currently it won't
  * play well with the Options stuff.  Until that is fixed, I would prefer
  * to leave it just in the conf file.  Other should feel free to disagree
  * with me.  Rbb.
  */
 AP_INIT_ITERATE("AddOutputFilter", add_filter, NULL, ACCESS_CONF,
    "filters to be run"),
+AP_INIT_ITERATE("AddInputFilter", add_input_filter, NULL, ACCESS_CONF,
+   "filters to be run on the request body"),
 { NULL }
 };
 
@@ -3436,6 +3451,12 @@ static void core_register_filter(request_rec *r)
         char *foobar = items[i];
         ap_add_output_filter(foobar, NULL, r, r->connection);
     }
+
+    items = (char **)conf->input_filters->elts;
+    for (i = 0; i < conf->input_filters->nelts; i++) {
+        char *foobar = items[i];
+        ap_add_input_filter(foobar, NULL, r, r->connection);
+    }
 }
 
 static void register_hooks(void)

modules/http/http_protocol.c

@@ -1249,6 +1249,7 @@ request_rec *ap_read_request(conn_rec *conn)
     r->status          = HTTP_REQUEST_TIME_OUT;  /* Until we get a request */
     r->the_request     = NULL;
     r->output_filters  = conn->output_filters;
+    r->input_filters   = conn->input_filters;
 
 #ifdef APACHE_XLATE
     r->rrx = apr_pcalloc(p, sizeof(struct ap_rr_xlate));

modules/http/http_request.c

@@ -780,6 +780,7 @@ API_EXPORT(request_rec *) ap_sub_req_method_uri(const char *method,
 
     /* start with the same set of output filters */
     rnew->output_filters = r->output_filters;
+    /* no input filters for a subrequest */
 
     ap_set_sub_req_protocol(rnew, r);
 
@@ -875,6 +876,7 @@ API_EXPORT(request_rec *) ap_sub_req_lookup_file(const char *new_file,
 
     /* start with the same set of output filters */
     rnew->output_filters = r->output_filters;
+    /* no input filters for a subrequest */
 
     ap_set_sub_req_protocol(rnew, r);
     fdir = ap_make_dirstr_parent(rnew->pool, r->filename);
@@ -1374,6 +1376,7 @@ static request_rec *internal_internal_redirect(const char *new_uri,
     new->vlist_validator = r->vlist_validator;
 
     new->output_filters  = r->connection->output_filters;
+    new->input_filters   = r->connection->input_filters;
 
     apr_table_setn(new->subprocess_env, "REDIRECT_STATUS",
 	apr_psprintf(r->pool, "%d", r->status));

server/connection.c

@@ -216,7 +216,7 @@ CORE_EXPORT(void) ap_process_connection(conn_rec *c)
 
 int ap_pre_http_connection(conn_rec *c)
 {
-    ap_add_input_filter("CORE_IN", NULL, c);
+    ap_add_input_filter("CORE_IN", NULL, NULL, c);
     ap_add_output_filter("CORE", NULL, NULL, c);
     return OK;
 }

server/util_filter.c

@@ -118,25 +118,28 @@ API_EXPORT(void) ap_register_output_filter(const char *name,
                     &registered_output_filters);
 }
 
-API_EXPORT(void) ap_add_input_filter(const char *name, void *ctx, conn_rec *c)
+API_EXPORT(void) ap_add_input_filter(const char *name, void *ctx, 
+                                     request_rec *r, conn_rec *c)
 {
     ap_filter_rec_t *frec = registered_input_filters;
 
     for (; frec != NULL; frec = frec->next) {
         if (!strcasecmp(name, frec->name)) {
-            ap_filter_t *f = apr_pcalloc(c->pool, sizeof(*f));
+            apr_pool_t *p = r ? r->pool : c->pool;
+            ap_filter_t *f = apr_pcalloc(p, sizeof(*f));
+            ap_filter_t **outf = r ? &r->input_filters : &c->input_filters;
 
             f->frec = frec;
             f->ctx = ctx;
-            f->r = NULL;
+            f->r = r;
             f->c = c;
 
-            if (INSERT_BEFORE(f, c->input_filters)) {
-                f->next = c->input_filters;
-                c->input_filters = f;
+            if (INSERT_BEFORE(f, *outf)) {
+                f->next = *outf;
+                *outf = f;
             }
             else {
-                ap_filter_t *fscan = c->input_filters;
+                ap_filter_t *fscan = *outf;
                 while (!INSERT_BEFORE(f, fscan->next))
                     fscan = fscan->next;
                 f->next = fscan->next;