new file mode 100644
--- /dev/null
+++ b/src/http/modules/ngx_http_addition_filter_module.c
@@ -0,0 +1,228 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_http.h>
+
+
+typedef struct {
+    ngx_str_t   before_body;
+    ngx_str_t   after_body;
+} ngx_http_addition_conf_t;
+
+
+typedef struct {
+    unsigned    before_body_sent:1;
+    unsigned    after_body_sent:1;
+} ngx_http_addition_ctx_t;
+
+
+static ngx_int_t ngx_http_addition_filter_init(ngx_cycle_t *cycle);
+static void *ngx_http_addition_create_conf(ngx_conf_t *cf);
+static char *ngx_http_addition_merge_conf(ngx_conf_t *cf, void *parent,
+    void *child);
+
+
+static ngx_command_t  ngx_http_addition_commands[] = {
+
+    { ngx_string("add_before_body"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_str_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_addition_conf_t, before_body),
+      NULL },
+
+    { ngx_string("add_after_body"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_str_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_addition_conf_t, after_body),
+      NULL },
+
+      ngx_null_command
+};
+
+
+static ngx_http_module_t  ngx_http_addition_filter_module_ctx = {
+    NULL,                                  /* preconfiguration */
+    NULL,                                  /* postconfiguration */
+
+    NULL,                                  /* create main configuration */
+    NULL,                                  /* init main configuration */
+
+    NULL,                                  /* create server configuration */
+    NULL,                                  /* merge server configuration */
+
+    ngx_http_addition_create_conf,         /* create location configuration */
+    ngx_http_addition_merge_conf           /* merge location configuration */
+};
+
+
+ngx_module_t  ngx_http_addition_filter_module = {
+    NGX_MODULE_V1,
+    &ngx_http_addition_filter_module_ctx,  /* module context */
+    ngx_http_addition_commands,            /* module directives */
+    NGX_HTTP_MODULE,                       /* module type */
+    NULL,                                  /* init master */
+    ngx_http_addition_filter_init,         /* init module */
+    NULL,                                  /* init process */
+    NULL,                                  /* init thread */
+    NULL,                                  /* exit thread */
+    NULL,                                  /* exit process */
+    NULL,                                  /* exit master */
+    NGX_MODULE_V1_PADDING
+};
+
+
+static ngx_http_output_header_filter_pt  ngx_http_next_header_filter;
+static ngx_http_output_body_filter_pt    ngx_http_next_body_filter;
+
+
+static ngx_int_t
+ngx_http_addition_header_filter(ngx_http_request_t *r)
+{
+    ngx_http_addition_ctx_t   *ctx;
+    ngx_http_addition_conf_t  *conf;
+
+    if (r->headers_out.status != NGX_HTTP_OK || r != r->main) {
+        return ngx_http_next_header_filter(r);
+    }
+
+    if (ngx_strncasecmp(r->headers_out.content_type.data, "text/html",
+                        sizeof("text/html") - 1)
+        != 0)
+    {
+        return ngx_http_next_header_filter(r);
+    }
+
+    conf = ngx_http_get_module_loc_conf(r, ngx_http_addition_filter_module);
+
+    if (conf->before_body.len == 0 && conf->after_body.len == 0) {
+        return ngx_http_next_header_filter(r);
+    }
+
+    ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_addition_ctx_t));
+    if (ctx == NULL) {
+        return NGX_ERROR;
+    }
+
+    ngx_http_set_ctx(r, ctx, ngx_http_addition_filter_module);
+
+    ngx_http_clear_content_length(r);
+    ngx_http_clear_accept_ranges(r);
+
+    return ngx_http_next_header_filter(r);
+}
+
+
+static ngx_int_t
+ngx_http_addition_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
+{
+    ngx_int_t                  rc;
+    ngx_uint_t                 last;
+    ngx_chain_t               *cl;
+    ngx_http_addition_ctx_t   *ctx;
+    ngx_http_addition_conf_t  *conf;
+
+    if (in == NULL || r->header_only) {
+        return ngx_http_next_body_filter(r, in);
+    }
+
+    ctx = ngx_http_get_module_ctx(r, ngx_http_addition_filter_module);
+
+    if (ctx == NULL) {
+        return ngx_http_next_body_filter(r, in);
+    }
+
+    conf = ngx_http_get_module_loc_conf(r, ngx_http_addition_filter_module);
+
+    if (!ctx->before_body_sent) {
+        ctx->before_body_sent = 1;
+
+        if (conf->before_body.len) {
+            if (ngx_http_subrequest(r, &conf->before_body, NULL, 0) != NGX_OK) {
+                return NGX_ERROR;
+            }
+        }
+    }
+
+    last = 0;
+
+    for (cl = in; cl; cl = cl->next) {
+        if (cl->buf->last_buf) {
+            cl->buf->last_buf = 0;
+            last = 1;
+        }
+    }
+
+    rc = ngx_http_next_body_filter(r, in);
+
+    if (rc == NGX_ERROR
+        || !last
+        || ctx->after_body_sent
+        || conf->after_body.len == 0)
+    {
+        return rc;
+    }
+
+    if (ngx_http_subrequest(r, &conf->after_body, NULL, 0) != NGX_OK) {
+        return NGX_ERROR;
+    }
+
+    ctx->after_body_sent = 1;
+
+    return ngx_http_send_special(r, NGX_HTTP_LAST);
+}
+
+
+static ngx_int_t
+ngx_http_addition_filter_init(ngx_cycle_t *cycle)
+{
+    ngx_http_next_header_filter = ngx_http_top_header_filter;
+    ngx_http_top_header_filter = ngx_http_addition_header_filter;
+
+    ngx_http_next_body_filter = ngx_http_top_body_filter;
+    ngx_http_top_body_filter = ngx_http_addition_body_filter;
+
+    return NGX_OK;
+}
+
+
+static void *
+ngx_http_addition_create_conf(ngx_conf_t *cf)
+{
+    ngx_http_addition_conf_t  *conf;
+
+    conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_addition_conf_t));
+    if (conf == NULL) {
+        return NGX_CONF_ERROR;
+    }
+
+    /*
+     * set by ngx_pcalloc():
+     *
+     *     conf->before_body.len = 0;
+     *     conf->before_body.date = NULL;
+     *     conf->after_body.len = 0;
+     *     conf->after_body.date = NULL;
+     */
+
+    return conf;
+}
+
+
+static char *
+ngx_http_addition_merge_conf(ngx_conf_t *cf, void *parent, void *child)
+{
+    ngx_http_addition_conf_t *prev = parent;
+    ngx_http_addition_conf_t *conf = child;
+
+    ngx_conf_merge_str_value(conf->before_body, prev->before_body, "");
+    ngx_conf_merge_str_value(conf->after_body, prev->after_body, "");
+
+    return NGX_CONF_OK;
+}