new file mode 100644
--- /dev/null
+++ b/src/os/unix/ngx_channel.c
@@ -0,0 +1,237 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_channel.h>
+
+
+ngx_int_t ngx_write_channel(ngx_socket_t s, ngx_channel_t *ch, size_t size,
+                            ngx_log_t *log) 
+{
+    ssize_t             n;
+    ngx_err_t           err;
+    struct iovec        iov[1];
+    struct msghdr       msg;
+
+#if (HAVE_MSGHDR_MSG_CONTROL)
+
+    union {
+        struct cmsghdr  cm;
+        char            space[CMSG_SPACE(sizeof(int))];
+    } cmsg;
+
+    if (ch->fd == -1) {
+        msg.msg_control = NULL;
+        msg.msg_controllen = 0;
+
+    } else {
+        msg.msg_control = (caddr_t) &cmsg;
+        msg.msg_controllen = sizeof(cmsg);
+
+        cmsg.cm.cmsg_len = sizeof(cmsg);
+        cmsg.cm.cmsg_level = SOL_SOCKET; 
+        cmsg.cm.cmsg_type = SCM_RIGHTS;
+        *(int *) CMSG_DATA(&cmsg.cm) = ch->fd;
+    }
+
+#else
+
+    if (ch->fd == -1) {
+        msg.msg_accrights = NULL;
+        msg.msg_accrightslen = 0;
+
+    } else {
+        msg.msg_accrights = (caddr_t) &ch->fd;
+        msg.msg_accrightslen = sizeof(int);
+    }
+
+#endif
+
+    iov[0].iov_base = (char *) ch;
+    iov[0].iov_len = size;
+
+    msg.msg_name = NULL;
+    msg.msg_namelen = 0;
+    msg.msg_iov = iov;
+    msg.msg_iovlen = 1;
+
+    n = sendmsg(s, &msg, 0);
+
+    if (n == -1) {
+        err = ngx_errno;
+        if (err == NGX_EAGAIN) {
+            return NGX_AGAIN;
+        }
+
+        ngx_log_error(NGX_LOG_ALERT, log, err, "sendmsg() failed");
+        return NGX_ERROR;
+    }
+
+    return NGX_OK;
+}
+
+
+ngx_int_t ngx_read_channel(ngx_socket_t s, ngx_channel_t *ch, size_t size,
+                           ngx_log_t *log)
+{   
+    ssize_t             n;
+    ngx_err_t           err;
+    struct iovec        iov[1];
+    struct msghdr       msg;
+
+#if (HAVE_MSGHDR_MSG_CONTROL)
+    union {
+        struct cmsghdr  cm;
+        char            space[CMSG_SPACE(sizeof(int))];
+    } cmsg;
+#else
+    int                 fd;
+#endif
+
+    iov[0].iov_base = (char *) ch;
+    iov[0].iov_len = size;
+
+    msg.msg_name = NULL;
+    msg.msg_namelen = 0;
+    msg.msg_iov = iov;
+    msg.msg_iovlen = 1;
+
+#if (HAVE_MSGHDR_MSG_CONTROL)
+    msg.msg_control = (caddr_t) &cmsg;
+    msg.msg_controllen = sizeof(cmsg);
+#else
+    msg.msg_accrights = (caddr_t) &fd;
+    msg.msg_accrightslen = sizeof(int);
+#endif
+
+    n = recvmsg(s, &msg, 0);
+
+    if (n == -1) {
+        err = ngx_errno;
+        if (err == NGX_EAGAIN) {
+            return NGX_AGAIN;
+        }
+
+        ngx_log_error(NGX_LOG_ALERT, log, err, "recvmsg() failed");
+        return NGX_ERROR;
+    }
+
+    if ((size_t) n < sizeof(ngx_channel_t)) {
+        ngx_log_error(NGX_LOG_ALERT, log, 0,
+                      "recvmsg() returned not enough data");
+        return NGX_ERROR;
+    }
+
+#if (HAVE_MSGHDR_MSG_CONTROL)
+
+    if (ch->command == NGX_CMD_OPEN_CHANNEL) {
+
+        if (cmsg.cm.cmsg_len < sizeof(cmsg)) {
+            ngx_log_error(NGX_LOG_ALERT, log, 0,
+                          "recvmsg() returned too small ancillary data");
+            return NGX_ERROR;
+        }
+
+        if (cmsg.cm.cmsg_level != SOL_SOCKET || cmsg.cm.cmsg_type != SCM_RIGHTS)
+        {
+            ngx_log_error(NGX_LOG_ALERT, log, 0,
+                          "recvmsg() returned invalid ancillary data "
+                          "level %d or type %d",
+                          cmsg.cm.cmsg_level, cmsg.cm.cmsg_type);
+            return NGX_ERROR;
+        }
+
+        ch->fd = *(int *) CMSG_DATA(&cmsg.cm);
+    }
+
+    if (msg.msg_flags & (MSG_TRUNC|MSG_CTRUNC)) {
+        ngx_log_error(NGX_LOG_ALERT, log, 0,
+                      "recvmsg() truncated data");
+    }
+
+#else
+
+    if (ch->command == NGX_CMD_OPEN_CHANNEL) {
+        if (msg.msg_accrightslen != sizeof(int)) {
+            ngx_log_error(NGX_LOG_ALERT, log, 0, 
+                          "recvmsg() returned no ancillary data");
+            return NGX_ERROR;
+        }
+
+        ch->fd = fd;
+    }
+
+#endif
+
+    return n;
+}
+
+
+ngx_int_t ngx_add_channel_event(ngx_cycle_t *cycle, ngx_fd_t fd,
+                                ngx_int_t event, ngx_event_handler_pt handler)
+{
+    ngx_event_t       *ev, *rev, *wev;
+    ngx_connection_t  *c;
+
+    c = &cycle->connections[fd];
+    rev = &cycle->read_events[fd];
+    wev = &cycle->write_events[fd];
+
+    ngx_memzero(c, sizeof(ngx_connection_t));
+    ngx_memzero(rev, sizeof(ngx_event_t));
+    ngx_memzero(wev, sizeof(ngx_event_t));
+
+    c->fd = fd;
+    c->pool = cycle->pool;
+
+    c->read = rev;
+    c->write = wev;
+
+    c->log = cycle->log;
+    rev->log = cycle->log;
+    wev->log = cycle->log;
+    rev->index = NGX_INVALID_INDEX;
+    wev->index = NGX_INVALID_INDEX;
+    rev->data = c;
+    wev->data = c;
+
+#if (NGX_THREADS)
+    rev->lock = &c->lock;
+    wev->lock = &c->lock;
+    rev->own_lock = &c->lock;
+    wev->own_lock = &c->lock;
+#endif
+
+    ev = (event == NGX_READ_EVENT) ? rev : wev;
+
+    ev->event_handler = handler;
+
+    if (ngx_add_conn && (ngx_event_flags & NGX_USE_EPOLL_EVENT) == 0) {
+        if (ngx_add_conn(c) == NGX_ERROR) {
+            return NGX_ERROR;
+        }
+    
+    } else { 
+        if (ngx_add_event(ev, event, 0) == NGX_ERROR) {
+            return NGX_ERROR;
+        }
+    }
+
+    return NGX_OK;
+}
+
+
+void ngx_close_channel(ngx_fd_t *fd, ngx_log_t *log)
+{
+    if (close(fd[0]) == -1) {
+        ngx_log_error(NGX_LOG_ALERT, log, ngx_errno, "close() failed");
+    }
+
+    if (close(fd[1]) == -1) {
+        ngx_log_error(NGX_LOG_ALERT, log, ngx_errno, "close() failed");
+    }
+}