cffi-posix/cffi-socket

diff --git a/cffi-sockets.lisp b/cffi-sockets.lisp
index 3616a66..31dbd21 100644
--- a/cffi-sockets.lisp
+++ b/cffi-sockets.lisp
@@ -160,3 +160,13 @@
      for r = (send sockfd buffer flags :start start :end end)
      do (when (= r 0) (error "end of file"))
      do (incf start r)))
+
+(defcfun ("shutdown" c-shutdown) :int
+  (sockfd :int)
+  (how :int))
+
+(defun shutdown (sockfd &optional read write)
+  (when (or read write)
+    (c-shutdown sockfd (cond ((and read write) +shut-rdwr+)
+			     (read +shut-rd+)
+			     (write +shut-wr+)))))
diff --git a/grovel-sockets.lisp b/grovel-sockets.lisp
index ab2db22..09640d4 100644
--- a/grovel-sockets.lisp
+++ b/grovel-sockets.lisp
@@ -20,6 +20,10 @@
 (constant (+sock-nonblock+ "SOCK_NONBLOCK"))
 (constant (+sock-cloexec+  "SOCK_CLOEXEC"))
 
+(constant (+shut-rd+   "SHUT_RD"))
+(constant (+shut-wr+   "SHUT_WR"))
+(constant (+shut-rdwr+ "SHUT_RDWR"))
+
 (ctype socklen-t "socklen_t")
 (ctype size-t "size_t")
 (ctype ssize-t "ssize_t")
diff --git a/package.lisp b/package.lisp
index 9b0a313..fb464ac 100644
--- a/package.lisp
+++ b/package.lisp
@@ -18,6 +18,9 @@
    #:+sock-raw+
    #:+sock-nonblock+
    #:+sock-cloexec+
+   #:+shut-rd+
+   #:+shut-wr+
+   #:+shut-rdwr+
    #:file-descriptor
    #:socket
    #:with-socket
@@ -28,4 +31,5 @@
    #:recv
    #:recv-sequence
    #:send
-   #:send-sequence))
+   #:send-sequence
+   #:shutdown))