new file mode 100644
--- /dev/null
+++ b/src/core/ngx_connection.h
@@ -0,0 +1,152 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+#ifndef _NGX_CONNECTION_H_INCLUDED_
+#define _NGX_CONNECTION_H_INCLUDED_
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+
+
+typedef struct {
+    ngx_socket_t      fd;
+
+    struct sockaddr  *sockaddr;
+    socklen_t         socklen;    /* size of sockaddr */
+    int               addr;       /* offset to address in sockaddr */
+    int               addr_text_max_len;
+    ngx_str_t         addr_text;
+
+    int               family;
+    int               type;
+    int               protocol;
+    int               flags;      /* Winsock2 flags */
+
+    void            (*handler)(ngx_connection_t *c); /* handler of accepted
+                                                        connection */
+    void             *ctx;        /* ngx_http_conf_ctx_t, for example */
+    void             *servers;    /* array of ngx_http_in_addr_t, for example */
+
+    ngx_log_t        *log;
+    int               backlog;
+
+    size_t            pool_size;
+    size_t            post_accept_buffer_size; /* should be here because
+                                                  of the AcceptEx() preread */
+    time_t            post_accept_timeout;     /* should be here because
+                                                  of the deferred accept */
+
+    unsigned          new:1;
+    unsigned          remain:1;
+    unsigned          ignore:1;
+
+    unsigned          bound:1;       /* already bound */
+    unsigned          inherited:1;   /* inherited from previous process */
+    unsigned          nonblocking_accept:1;
+    unsigned          nonblocking:1;
+#if 0
+    unsigned          overlapped:1;  /* Winsock2 overlapped */
+#endif
+    unsigned          shared:1;    /* shared between threads or processes */
+#if (HAVE_DEFERRED_ACCEPT)
+    unsigned          deferred_accept:1;
+#endif
+
+    unsigned          addr_ntop:1;
+} ngx_listening_t;
+
+
+typedef enum {
+     NGX_ERROR_CRIT = 0,
+     NGX_ERROR_ERR,
+     NGX_ERROR_INFO,
+     NGX_ERROR_IGNORE_ECONNRESET
+} ngx_connection_log_error_e;
+
+
+typedef enum {
+     NGX_TCP_NOPUSH_DISABLED = -1,
+     NGX_TCP_NOPUSH_UNSET = 0,
+     NGX_TCP_NOPUSH_SET
+} ngx_connection_tcp_nopush_e;
+
+
+struct ngx_connection_s {
+    void               *data;
+    ngx_event_t        *read;
+    ngx_event_t        *write;
+
+    ngx_socket_t        fd;
+
+    ngx_recv_pt         recv;
+    ngx_send_chain_pt   send_chain;
+
+    ngx_listening_t    *listening;
+
+    off_t               sent;
+
+    void               *ctx;
+    void               *servers;
+
+
+    ngx_log_t          *log;
+
+    ngx_pool_t         *pool;
+
+    struct sockaddr    *sockaddr;
+    socklen_t           socklen;
+    ngx_str_t           addr_text;
+
+#if (NGX_OPENSSL)
+    ngx_ssl_t          *ssl;
+#endif
+
+#if (HAVE_IOCP)
+    struct sockaddr    *local_sockaddr;
+    socklen_t           local_socklen;
+#endif
+
+    ngx_buf_t          *buffer;
+
+    ngx_uint_t          number;
+
+    unsigned            log_error:2;  /* ngx_connection_log_error_e */
+
+    unsigned            buffered:1;
+    unsigned            single_connection:1;
+    unsigned            unexpected_eof:1;
+    unsigned            timedout:1;
+    signed              tcp_nopush:2;
+#if (HAVE_IOCP)
+    unsigned            accept_context_updated:1;
+#endif
+
+#if (NGX_THREADS)
+    ngx_atomic_t        lock;
+#endif
+};
+
+
+#ifndef ngx_ssl_set_nosendshut
+#define ngx_ssl_set_nosendshut(ssl)
+#endif
+
+
+ngx_listening_t *ngx_listening_inet_stream_socket(ngx_conf_t *cf,
+                                                 in_addr_t addr,
+                                                 in_port_t port);
+ngx_int_t ngx_set_inherited_sockets(ngx_cycle_t *cycle);
+ngx_int_t ngx_open_listening_sockets(ngx_cycle_t *cycle);
+void ngx_close_listening_sockets(ngx_cycle_t *cycle);
+void ngx_close_connection(ngx_connection_t *c);
+ngx_int_t ngx_connection_error(ngx_connection_t *c, ngx_err_t err, char *text);
+
+
+extern ngx_os_io_t  ngx_io;
+
+
+#endif /* _NGX_CONNECTION_H_INCLUDED_ */