new file mode 100644
--- /dev/null
+++ b/src/http/ngx_http_spdy_filter_module.c
@@ -0,0 +1,999 @@
+
+/*
+ * Copyright (C) Nginx, Inc.
+ * Copyright (C) Valentin V. Bartenev
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_http.h>
+#include <nginx.h>
+#include <ngx_http_spdy_module.h>
+
+#include <zlib.h>
+
+
+#define NGX_SPDY_WRITE_BUFFERED  NGX_HTTP_WRITE_BUFFERED
+
+#define ngx_http_spdy_nv_nsize(h)  (NGX_SPDY_NV_NLEN_SIZE + sizeof(h) - 1)
+#define ngx_http_spdy_nv_vsize(h)  (NGX_SPDY_NV_VLEN_SIZE + sizeof(h) - 1)
+
+#define ngx_http_spdy_nv_write_num   ngx_spdy_frame_write_uint16
+#define ngx_http_spdy_nv_write_nlen  ngx_spdy_frame_write_uint16
+#define ngx_http_spdy_nv_write_vlen  ngx_spdy_frame_write_uint16
+
+#define ngx_http_spdy_nv_write_name(p, h)                                     \
+    ngx_cpymem(ngx_http_spdy_nv_write_nlen(p, sizeof(h) - 1), h, sizeof(h) - 1)
+
+#define ngx_http_spdy_nv_write_val(p, h)                                      \
+    ngx_cpymem(ngx_http_spdy_nv_write_vlen(p, sizeof(h) - 1), h, sizeof(h) - 1)
+
+static ngx_inline ngx_int_t ngx_http_spdy_filter_send(
+    ngx_connection_t *fc, ngx_http_spdy_stream_t *stream);
+
+static ngx_http_spdy_out_frame_t *ngx_http_spdy_filter_get_data_frame(
+    ngx_http_spdy_stream_t *stream, size_t len, ngx_uint_t flags,
+    ngx_chain_t *first, ngx_chain_t *last);
+
+static ngx_int_t ngx_http_spdy_syn_frame_handler(
+    ngx_http_spdy_connection_t *sc, ngx_http_spdy_out_frame_t *frame);
+static ngx_int_t ngx_http_spdy_data_frame_handler(
+    ngx_http_spdy_connection_t *sc, ngx_http_spdy_out_frame_t *frame);
+static ngx_inline void ngx_http_spdy_handle_frame(
+    ngx_http_spdy_stream_t *stream, ngx_http_spdy_out_frame_t *frame);
+static ngx_inline void ngx_http_spdy_handle_stream(
+    ngx_http_spdy_connection_t *sc, ngx_http_spdy_stream_t *stream);
+
+static void ngx_http_spdy_filter_cleanup(void *data);
+
+static ngx_int_t ngx_http_spdy_filter_init(ngx_conf_t *cf);
+
+
+static ngx_http_module_t  ngx_http_spdy_filter_module_ctx = {
+    NULL,                                  /* preconfiguration */
+    ngx_http_spdy_filter_init,             /* postconfiguration */
+
+    NULL,                                  /* create main configuration */
+    NULL,                                  /* init main configuration */
+
+    NULL,                                  /* create server configuration */
+    NULL,                                  /* merge server configuration */
+
+    NULL,                                  /* create location configuration */
+    NULL                                   /* merge location configuration */
+};
+
+
+ngx_module_t  ngx_http_spdy_filter_module = {
+    NGX_MODULE_V1,
+    &ngx_http_spdy_filter_module_ctx,      /* module context */
+    NULL,                                  /* module directives */
+    NGX_HTTP_MODULE,                       /* module type */
+    NULL,                                  /* init master */
+    NULL,                                  /* 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_spdy_header_filter(ngx_http_request_t *r)
+{
+    int                           rc;
+    size_t                        len;
+    u_char                       *p, *buf, *last;
+    ngx_buf_t                    *b;
+    ngx_str_t                     host;
+    ngx_uint_t                    i, j, count, port;
+    ngx_chain_t                  *cl;
+    ngx_list_part_t              *part, *pt;
+    ngx_table_elt_t              *header, *h;
+    ngx_connection_t             *c;
+    ngx_http_cleanup_t           *cln;
+    ngx_http_core_loc_conf_t     *clcf;
+    ngx_http_core_srv_conf_t     *cscf;
+    ngx_http_spdy_stream_t       *stream;
+    ngx_http_spdy_out_frame_t    *frame;
+    ngx_http_spdy_connection_t   *sc;
+    struct sockaddr_in           *sin;
+#if (NGX_HAVE_INET6)
+    struct sockaddr_in6          *sin6;
+#endif
+    u_char                        addr[NGX_SOCKADDR_STRLEN];
+
+    if (!r->spdy_stream) {
+        return ngx_http_next_header_filter(r);
+    }
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "spdy header filter");
+
+    if (r->header_sent) {
+        return NGX_OK;
+    }
+
+    r->header_sent = 1;
+
+    if (r != r->main) {
+        return NGX_OK;
+    }
+
+    c = r->connection;
+
+    if (r->method == NGX_HTTP_HEAD) {
+        r->header_only = 1;
+    }
+
+    switch (r->headers_out.status) {
+
+    case NGX_HTTP_OK:
+    case NGX_HTTP_PARTIAL_CONTENT:
+        break;
+
+    case NGX_HTTP_NOT_MODIFIED:
+        r->header_only = 1;
+        break;
+
+    case NGX_HTTP_NO_CONTENT:
+        r->header_only = 1;
+
+        ngx_str_null(&r->headers_out.content_type);
+
+        r->headers_out.content_length = NULL;
+        r->headers_out.content_length_n = -1;
+
+        /* fall through */
+
+    default:
+        r->headers_out.last_modified_time = -1;
+        r->headers_out.last_modified = NULL;
+    }
+
+    len = NGX_SPDY_NV_NUM_SIZE
+          + ngx_http_spdy_nv_nsize("version")
+          + ngx_http_spdy_nv_vsize("HTTP/1.1")
+          + ngx_http_spdy_nv_nsize("status")
+          + ngx_http_spdy_nv_vsize("418");
+
+    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
+
+    if (r->headers_out.server == NULL) {
+        len += ngx_http_spdy_nv_nsize("server");
+        len += clcf->server_tokens ? ngx_http_spdy_nv_vsize(NGINX_VER)
+                                   : ngx_http_spdy_nv_vsize("nginx");
+    }
+
+    if (r->headers_out.date == NULL) {
+        len += ngx_http_spdy_nv_nsize("date")
+               + ngx_http_spdy_nv_vsize("Wed, 31 Dec 1986 10:00:00 GMT");
+    }
+
+    if (r->headers_out.content_type.len) {
+        len += ngx_http_spdy_nv_nsize("content-type")
+               + NGX_SPDY_NV_VLEN_SIZE + r->headers_out.content_type.len;
+
+        if (r->headers_out.content_type_len == r->headers_out.content_type.len
+            && r->headers_out.charset.len)
+        {
+            len += sizeof("; charset=") - 1 + r->headers_out.charset.len;
+        }
+    }
+
+    if (r->headers_out.content_length == NULL
+        && r->headers_out.content_length_n >= 0)
+    {
+        len += ngx_http_spdy_nv_nsize("content-length")
+               + NGX_SPDY_NV_VLEN_SIZE + NGX_OFF_T_LEN;
+    }
+
+    if (r->headers_out.last_modified == NULL
+        && r->headers_out.last_modified_time != -1)
+    {
+        len += ngx_http_spdy_nv_nsize("last-modified")
+               + ngx_http_spdy_nv_vsize("Wed, 31 Dec 1986 10:00:00 GMT");
+    }
+
+    if (r->headers_out.location
+        && r->headers_out.location->value.len
+        && r->headers_out.location->value.data[0] == '/')
+    {
+        r->headers_out.location->hash = 0;
+
+        if (clcf->server_name_in_redirect) {
+            cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);
+            host = cscf->server_name;
+
+        } else if (r->headers_in.server.len) {
+            host = r->headers_in.server;
+
+        } else {
+            host.len = NGX_SOCKADDR_STRLEN;
+            host.data = addr;
+
+            if (ngx_connection_local_sockaddr(c, &host, 0) != NGX_OK) {
+                return NGX_ERROR;
+            }
+        }
+
+        switch (c->local_sockaddr->sa_family) {
+
+#if (NGX_HAVE_INET6)
+        case AF_INET6:
+            sin6 = (struct sockaddr_in6 *) c->local_sockaddr;
+            port = ntohs(sin6->sin6_port);
+            break;
+#endif
+#if (NGX_HAVE_UNIX_DOMAIN)
+        case AF_UNIX:
+            port = 0;
+            break;
+#endif
+        default: /* AF_INET */
+            sin = (struct sockaddr_in *) c->local_sockaddr;
+            port = ntohs(sin->sin_port);
+            break;
+        }
+
+        len += ngx_http_spdy_nv_nsize("location")
+               + ngx_http_spdy_nv_vsize("https://")
+               + host.len
+               + r->headers_out.location->value.len;
+
+        if (clcf->port_in_redirect) {
+
+#if (NGX_HTTP_SSL)
+            if (c->ssl)
+                port = (port == 443) ? 0 : port;
+            else
+#endif
+                port = (port == 80) ? 0 : port;
+
+        } else {
+            port = 0;
+        }
+
+        if (port) {
+            len += sizeof(":65535") - 1;
+        }
+
+    } else {
+        ngx_str_null(&host);
+        port = 0;
+    }
+
+    part = &r->headers_out.headers.part;
+    header = part->elts;
+
+    for (i = 0; /* void */; i++) {
+
+        if (i >= part->nelts) {
+            if (part->next == NULL) {
+                break;
+            }
+
+            part = part->next;
+            header = part->elts;
+            i = 0;
+        }
+
+        if (header[i].hash == 0) {
+            continue;
+        }
+
+        len += NGX_SPDY_NV_NLEN_SIZE + header[i].key.len
+               + NGX_SPDY_NV_VLEN_SIZE  + header[i].value.len;
+    }
+
+    buf = ngx_alloc(len, r->pool->log);
+    if (buf == NULL) {
+        return NGX_ERROR;
+    }
+
+    last = buf + NGX_SPDY_NV_NUM_SIZE;
+
+    last = ngx_http_spdy_nv_write_name(last, "version");
+    last = ngx_http_spdy_nv_write_val(last, "HTTP/1.1");
+
+    last = ngx_http_spdy_nv_write_name(last, "status");
+    last = ngx_spdy_frame_write_uint16(last, 3);
+    last = ngx_sprintf(last, "%03ui", r->headers_out.status);
+
+    count = 2;
+
+    if (r->headers_out.server == NULL) {
+        last = ngx_http_spdy_nv_write_name(last, "server");
+        last = clcf->server_tokens
+               ? ngx_http_spdy_nv_write_val(last, NGINX_VER)
+               : ngx_http_spdy_nv_write_val(last, "nginx");
+
+        count++;
+    }
+
+    if (r->headers_out.date == NULL) {
+        last = ngx_http_spdy_nv_write_name(last, "date");
+
+        last = ngx_http_spdy_nv_write_vlen(last, ngx_cached_http_time.len);
+
+        last = ngx_cpymem(last, ngx_cached_http_time.data,
+                          ngx_cached_http_time.len);
+
+        count++;
+    }
+
+    if (r->headers_out.content_type.len) {
+
+        last = ngx_http_spdy_nv_write_name(last, "content-type");
+
+        p = last + NGX_SPDY_NV_VLEN_SIZE;
+
+        last = ngx_cpymem(p, r->headers_out.content_type.data,
+                          r->headers_out.content_type.len);
+
+        if (r->headers_out.content_type_len == r->headers_out.content_type.len
+            && r->headers_out.charset.len)
+        {
+            last = ngx_cpymem(last, "; charset=", sizeof("; charset=") - 1);
+
+            last = ngx_cpymem(last, r->headers_out.charset.data,
+                              r->headers_out.charset.len);
+
+            /* update r->headers_out.content_type for possible logging */
+
+            r->headers_out.content_type.len = last - p;
+            r->headers_out.content_type.data = p;
+        }
+
+        (void) ngx_http_spdy_nv_write_vlen(p - NGX_SPDY_NV_VLEN_SIZE,
+                                           r->headers_out.content_type.len);
+
+        count++;
+    }
+
+    if (r->headers_out.content_length == NULL
+        && r->headers_out.content_length_n >= 0)
+    {
+        last = ngx_http_spdy_nv_write_name(last, "content-length");
+
+        p = last + NGX_SPDY_NV_VLEN_SIZE;
+
+        last = ngx_sprintf(p, "%O", r->headers_out.content_length_n);
+
+        (void) ngx_http_spdy_nv_write_vlen(p - NGX_SPDY_NV_VLEN_SIZE,
+                                           last - p);
+
+        count++;
+    }
+
+    if (r->headers_out.last_modified == NULL
+        && r->headers_out.last_modified_time != -1)
+    {
+        last = ngx_http_spdy_nv_write_name(last, "last-modified");
+
+        p = last + NGX_SPDY_NV_VLEN_SIZE;
+
+        last = ngx_http_time(p, r->headers_out.last_modified_time);
+
+        (void) ngx_http_spdy_nv_write_vlen(p - NGX_SPDY_NV_VLEN_SIZE,
+                                           last - p);
+
+        count++;
+    }
+
+    if (host.data) {
+
+        last = ngx_http_spdy_nv_write_name(last, "location");
+
+        p = last + NGX_SPDY_NV_VLEN_SIZE;
+
+        last = ngx_cpymem(p, "http", sizeof("http") - 1);
+
+#if (NGX_HTTP_SSL)
+        if (c->ssl) {
+            *last++ ='s';
+        }
+#endif
+
+        *last++ = ':'; *last++ = '/'; *last++ = '/';
+
+        last = ngx_cpymem(last, host.data, host.len);
+
+        if (port) {
+            last = ngx_sprintf(last, ":%ui", port);
+        }
+
+        last = ngx_cpymem(last, r->headers_out.location->value.data,
+                          r->headers_out.location->value.len);
+
+        /* update r->headers_out.location->value for possible logging */
+
+        r->headers_out.location->value.len = last - p;
+        r->headers_out.location->value.data = p;
+        ngx_str_set(&r->headers_out.location->key, "location");
+
+        (void) ngx_http_spdy_nv_write_vlen(p - NGX_SPDY_NV_VLEN_SIZE,
+                                           r->headers_out.location->value.len);
+
+        count++;
+    }
+
+    part = &r->headers_out.headers.part;
+    header = part->elts;
+
+    for (i = 0; /* void */; i++) {
+
+        if (i >= part->nelts) {
+            if (part->next == NULL) {
+                break;
+            }
+
+            part = part->next;
+            header = part->elts;
+            i = 0;
+        }
+
+        if (header[i].hash == 0 || header[i].hash == 2) {
+            continue;
+        }
+
+        if ((header[i].key.len == 6
+             && ngx_strncasecmp(header[i].key.data,
+                                (u_char *) "status", 6) == 0)
+            || (header[i].key.len == 7
+                && ngx_strncasecmp(header[i].key.data,
+                                   (u_char *) "version", 7) == 0))
+        {
+            header[i].hash = 0;
+            continue;
+        }
+
+        last = ngx_http_spdy_nv_write_nlen(last, header[i].key.len);
+
+        ngx_strlow(last, header[i].key.data, header[i].key.len);
+        last += header[i].key.len;
+
+        p = last + NGX_SPDY_NV_VLEN_SIZE;
+
+        last = ngx_cpymem(p, header[i].value.data, header[i].value.len);
+
+        pt = part;
+        h = header;
+
+        for (j = i + 1; /* void */; j++) {
+
+            if (j >= pt->nelts) {
+                if (pt->next == NULL) {
+                    break;
+                }
+
+                pt = pt->next;
+                h = pt->elts;
+                j = 0;
+            }
+
+            if (h[j].hash == 0 || h[j].hash == 2
+                || h[j].key.len != header[i].key.len
+                || ngx_strncasecmp(header[i].key.data, h[j].key.data,
+                                   header[i].key.len))
+            {
+                continue;
+            }
+
+            *last++ = '\0';
+
+            last = ngx_cpymem(last, h[j].value.data, h[j].value.len);
+
+            h[j].hash = 2;
+        }
+
+        (void) ngx_http_spdy_nv_write_vlen(p - NGX_SPDY_NV_VLEN_SIZE,
+                                           last - p);
+
+        count++;
+    }
+
+    (void) ngx_spdy_frame_write_uint16(buf, count);
+
+    stream = r->spdy_stream;
+    sc = stream->connection;
+
+    len = last - buf;
+
+    b = ngx_create_temp_buf(r->pool, NGX_SPDY_FRAME_HEADER_SIZE
+                                     + NGX_SPDY_SYN_REPLY_SIZE
+                                     + deflateBound(&sc->zstream_out, len));
+    if (b == NULL) {
+        ngx_free(buf);
+        return NGX_ERROR;
+    }
+
+    b->last += NGX_SPDY_FRAME_HEADER_SIZE + NGX_SPDY_SYN_REPLY_SIZE;
+
+    sc->zstream_out.next_in = buf;
+    sc->zstream_out.avail_in = len;
+    sc->zstream_out.next_out = b->last;
+    sc->zstream_out.avail_out = b->end - b->last;
+
+    rc = deflate(&sc->zstream_out, Z_SYNC_FLUSH);
+
+    ngx_free(buf);
+
+    if (rc != Z_OK) {
+        ngx_log_error(NGX_LOG_ALERT, c->log, 0,
+                      "spdy deflate() failed: %d", rc);
+        return NGX_ERROR;
+    }
+
+    ngx_log_debug5(NGX_LOG_DEBUG_HTTP, c->log, 0,
+                   "spdy deflate out: ni:%p no:%p ai:%ud ao:%ud rc:%d",
+                   sc->zstream_out.next_in, sc->zstream_out.next_out,
+                   sc->zstream_out.avail_in, sc->zstream_out.avail_out,
+                   rc);
+
+    b->last = sc->zstream_out.next_out;
+
+    p = b->pos;
+    p = ngx_spdy_frame_write_head(p, NGX_SPDY_SYN_REPLY);
+
+    len = b->last - b->pos;
+
+    r->header_size = len;
+
+    if (r->header_only) {
+        b->last_buf = 1;
+        p = ngx_spdy_frame_write_flags_and_len(p, NGX_SPDY_FLAG_FIN,
+                                             len - NGX_SPDY_FRAME_HEADER_SIZE);
+    } else {
+        p = ngx_spdy_frame_write_flags_and_len(p, 0,
+                                             len - NGX_SPDY_FRAME_HEADER_SIZE);
+    }
+
+    (void) ngx_spdy_frame_write_sid(p, stream->id);
+
+    cl = ngx_alloc_chain_link(r->pool);
+    if (cl == NULL) {
+        return NGX_ERROR;
+    }
+
+    cl->buf = b;
+    cl->next = NULL;
+
+    frame = ngx_palloc(r->pool, sizeof(ngx_http_spdy_out_frame_t));
+    if (frame == NULL) {
+        return NGX_ERROR;
+    }
+
+    frame->first = cl;
+    frame->last = cl;
+    frame->handler = ngx_http_spdy_syn_frame_handler;
+    frame->free = NULL;
+    frame->stream = stream;
+    frame->size = len;
+    frame->priority = stream->priority;
+    frame->blocked = 1;
+    frame->fin = r->header_only;
+
+    ngx_log_debug3(NGX_LOG_DEBUG_HTTP, stream->request->connection->log, 0,
+                   "spdy:%ui create SYN_REPLY frame %p: size:%uz",
+                   stream->id, frame, frame->size);
+
+    ngx_http_spdy_queue_blocked_frame(sc, frame);
+
+    r->blocked++;
+
+    cln = ngx_http_cleanup_add(r, 0);
+    if (cln == NULL) {
+        return NGX_ERROR;
+    }
+
+    cln->handler = ngx_http_spdy_filter_cleanup;
+    cln->data = stream;
+
+    stream->waiting = 1;
+
+    return ngx_http_spdy_filter_send(c, stream);
+}
+
+
+static ngx_int_t
+ngx_http_spdy_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
+{
+    off_t                       size;
+    ngx_buf_t                  *b;
+    ngx_chain_t                *cl, *ll, *out, **ln;
+    ngx_http_spdy_stream_t     *stream;
+    ngx_http_spdy_out_frame_t  *frame;
+
+    stream = r->spdy_stream;
+
+    if (stream == NULL) {
+        return ngx_http_next_body_filter(r, in);
+    }
+
+    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "spdy body filter \"%V?%V\"", &r->uri, &r->args);
+
+    if (in == NULL || r->header_only) {
+
+        if (stream->waiting) {
+            return NGX_AGAIN;
+        }
+
+        r->connection->buffered &= ~NGX_SPDY_WRITE_BUFFERED;
+
+        return NGX_OK;
+    }
+
+    size = 0;
+    ln = &out;
+    ll = in;
+
+    for ( ;; ) {
+        b = ll->buf;
+#if 1
+        if (ngx_buf_size(b) == 0 && !ngx_buf_special(b)) {
+            ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
+                          "zero size buf in spdy body filter "
+                          "t:%d r:%d f:%d %p %p-%p %p %O-%O",
+                          b->temporary,
+                          b->recycled,
+                          b->in_file,
+                          b->start,
+                          b->pos,
+                          b->last,
+                          b->file,
+                          b->file_pos,
+                          b->file_last);
+
+            ngx_debug_point();
+            return NGX_ERROR;
+        }
+#endif
+        cl = ngx_alloc_chain_link(r->pool);
+        if (cl == NULL) {
+            return NGX_ERROR;
+        }
+
+        size += ngx_buf_size(b);
+        cl->buf = b;
+
+        *ln = cl;
+        ln = &cl->next;
+
+        if (ll->next == NULL) {
+            break;
+        }
+
+        ll = ll->next;
+    }
+
+    if (size > NGX_SPDY_MAX_FRAME_SIZE) {
+        ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
+                      "FIXME: chain too big in spdy filter: %O", size);
+        return NGX_ERROR;
+    }
+
+    frame = ngx_http_spdy_filter_get_data_frame(stream, (size_t) size,
+                                                b->last_buf, out, cl);
+    if (frame == NULL) {
+        return NGX_ERROR;
+    }
+
+    ngx_http_spdy_queue_frame(stream->connection, frame);
+
+    stream->waiting++;
+
+    r->main->blocked++;
+
+    return ngx_http_spdy_filter_send(r->connection, stream);
+}
+
+
+static ngx_http_spdy_out_frame_t *
+ngx_http_spdy_filter_get_data_frame(ngx_http_spdy_stream_t *stream,
+    size_t len, ngx_uint_t fin, ngx_chain_t *first, ngx_chain_t *last)
+{
+    u_char                     *p;
+    ngx_buf_t                  *buf;
+    ngx_uint_t                  flags;
+    ngx_chain_t                *cl;
+    ngx_http_spdy_out_frame_t  *frame;
+
+
+    frame = stream->free_frames;
+
+    if (frame) {
+        stream->free_frames = frame->free;
+
+    } else {
+        frame = ngx_palloc(stream->request->pool,
+                           sizeof(ngx_http_spdy_out_frame_t));
+        if (frame == NULL) {
+            return NULL;
+        }
+    }
+
+    ngx_log_debug4(NGX_LOG_DEBUG_HTTP, stream->request->connection->log, 0,
+                   "spdy:%ui create DATA frame %p: len:%uz fin:%ui",
+                   stream->id, frame, len, fin);
+
+    if (len || fin) {
+
+        flags = fin ? NGX_SPDY_FLAG_FIN : 0;
+
+        cl = ngx_chain_get_free_buf(stream->request->pool,
+                                    &stream->free_data_headers);
+        if (cl == NULL) {
+            return NULL;
+        }
+
+        buf = cl->buf;
+
+        if (buf->start) {
+            p = buf->start;
+            buf->pos = p;
+
+            p += sizeof(uint32_t);
+
+            (void) ngx_spdy_frame_write_flags_and_len(p, flags, len);
+
+        } else {
+            p = ngx_palloc(stream->request->pool, NGX_SPDY_FRAME_HEADER_SIZE);
+            if (p == NULL) {
+                return NULL;
+            }
+
+            buf->pos = p;
+            buf->start = p;
+
+            p = ngx_spdy_frame_write_sid(p, stream->id);
+            p = ngx_spdy_frame_write_flags_and_len(p, flags, len);
+
+            buf->last = p;
+            buf->end = p;
+
+            buf->tag = (ngx_buf_tag_t) &ngx_http_spdy_filter_module;
+            buf->memory = 1;
+        }
+
+        cl->next = first;
+        first = cl;
+    }
+
+    frame->first = first;
+    frame->last = last;
+    frame->handler = ngx_http_spdy_data_frame_handler;
+    frame->free = NULL;
+    frame->stream = stream;
+    frame->size = NGX_SPDY_FRAME_HEADER_SIZE + len;
+    frame->priority = stream->priority;
+    frame->blocked = 0;
+    frame->fin = fin;
+
+    return frame;
+}
+
+
+static ngx_inline ngx_int_t
+ngx_http_spdy_filter_send(ngx_connection_t *fc, ngx_http_spdy_stream_t *stream)
+{
+    if (ngx_http_spdy_send_output_queue(stream->connection) == NGX_ERROR) {
+        fc->error = 1;
+        return NGX_ERROR;
+    }
+
+    if (stream->waiting) {
+        fc->buffered |= NGX_SPDY_WRITE_BUFFERED;
+        fc->write->delayed = 1;
+        return NGX_AGAIN;
+    }
+
+    fc->buffered &= ~NGX_SPDY_WRITE_BUFFERED;
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_spdy_syn_frame_handler(ngx_http_spdy_connection_t *sc,
+    ngx_http_spdy_out_frame_t *frame)
+{
+    ngx_buf_t               *buf;
+    ngx_http_spdy_stream_t  *stream;
+
+    buf = frame->first->buf;
+
+    if (buf->pos != buf->last) {
+        return NGX_AGAIN;
+    }
+
+    stream = frame->stream;
+
+    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, sc->connection->log, 0,
+                   "spdy:%ui SYN_REPLY frame %p was sent", stream->id, frame);
+
+    ngx_free_chain(stream->request->pool, frame->first);
+
+    ngx_http_spdy_handle_frame(stream, frame);
+
+    ngx_http_spdy_handle_stream(sc, stream);
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_spdy_data_frame_handler(ngx_http_spdy_connection_t *sc,
+    ngx_http_spdy_out_frame_t *frame)
+{
+    ngx_chain_t             *cl, *ln;
+    ngx_http_spdy_stream_t  *stream;
+
+    stream = frame->stream;
+
+    cl = frame->first;
+
+    if (cl->buf->tag == (ngx_buf_tag_t) &ngx_http_spdy_filter_module) {
+
+        if (cl->buf->pos != cl->buf->last) {
+            ngx_log_debug2(NGX_LOG_DEBUG_HTTP, sc->connection->log, 0,
+                           "spdy:%ui DATA frame %p was sent partially",
+                           stream->id, frame);
+
+            return NGX_AGAIN;
+        }
+
+        ln = cl->next;
+
+        cl->next = stream->free_data_headers;
+        stream->free_data_headers = cl;
+
+        if (cl == frame->last) {
+            goto done;
+        }
+
+        cl = ln;
+    }
+
+    for ( ;; ) {
+        if (ngx_buf_size(cl->buf) != 0) {
+
+            if (cl != frame->first) {
+                frame->first = cl;
+                ngx_http_spdy_handle_stream(sc, stream);
+            }
+
+            ngx_log_debug2(NGX_LOG_DEBUG_HTTP, sc->connection->log, 0,
+                           "spdy:%ui DATA frame %p was sent partially",
+                           stream->id, frame);
+
+            return NGX_AGAIN;
+        }
+
+        ln = cl->next;
+
+        ngx_free_chain(stream->request->pool, cl);
+
+        if (cl == frame->last) {
+            goto done;
+        }
+
+        cl = ln;
+    }
+
+done:
+
+    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, sc->connection->log, 0,
+                   "spdy:%ui DATA frame %p was sent", stream->id, frame);
+
+    stream->request->header_size += NGX_SPDY_FRAME_HEADER_SIZE;
+
+    ngx_http_spdy_handle_frame(stream, frame);
+
+    ngx_http_spdy_handle_stream(sc, stream);
+
+    return NGX_OK;
+}
+
+
+static ngx_inline void
+ngx_http_spdy_handle_frame(ngx_http_spdy_stream_t *stream,
+    ngx_http_spdy_out_frame_t *frame)
+{
+    ngx_http_request_t  *r;
+
+    r = stream->request;
+
+    r->connection->sent += frame->size;
+    r->blocked--;
+
+    if (frame->fin) {
+        stream->out_closed = 1;
+    }
+
+    frame->free = stream->free_frames;
+    stream->free_frames = frame;
+
+    stream->waiting--;
+}
+
+
+static ngx_inline void
+ngx_http_spdy_handle_stream(ngx_http_spdy_connection_t *sc,
+    ngx_http_spdy_stream_t *stream)
+{
+    ngx_connection_t  *fc;
+
+    fc = stream->request->connection;
+
+    fc->write->delayed = 0;
+
+    if (stream->handled) {
+        return;
+    }
+
+    if (sc->blocked == 2) {
+        stream->handled = 1;
+
+        stream->next = sc->last_stream;
+        sc->last_stream = stream;
+    }
+}
+
+
+static void
+ngx_http_spdy_filter_cleanup(void *data)
+{
+    ngx_http_spdy_stream_t *stream = data;
+
+    ngx_http_request_t         *r;
+    ngx_http_spdy_out_frame_t  *frame, **fn;
+
+    if (stream->waiting == 0) {
+        return;
+    }
+
+    r = stream->request;
+
+    fn = &stream->connection->last_out;
+
+    for ( ;; ) {
+        frame = *fn;
+
+        if (frame == NULL) {
+            break;
+        }
+
+        if (frame->stream == stream && !frame->blocked) {
+
+            stream->waiting--;
+            r->blocked--;
+
+            *fn = frame->next;
+            continue;
+        }
+
+        fn = &frame->next;
+    }
+}
+
+
+static ngx_int_t
+ngx_http_spdy_filter_init(ngx_conf_t *cf)
+{
+    ngx_http_next_header_filter = ngx_http_top_header_filter;
+    ngx_http_top_header_filter = ngx_http_spdy_header_filter;
+
+    ngx_http_next_body_filter = ngx_http_top_body_filter;
+    ngx_http_top_body_filter = ngx_http_spdy_body_filter;
+
+    return NGX_OK;
+}