contrib/sb-bsd-sockets/sockopt.lisp

   1 (in-package :sb-bsd-sockets)
   2
   3 #|
   4 getsockopt(socket, level, int optname, void *optval, socklen_t *optlen)
   5 setsockopt(socket, level, int optname, void *optval, socklen_t optlen)
   6              ^ SOL_SOCKET or a protocol number
   7
   8 In terms of providing a useful interface, we have to face up to the
   9 fact that most of these take different data types - some are integers,
  10 some are booleans, some are foreign struct instances, etc etc
  11
  12  (define-socket-option lisp-name doc level number mangle-arg size mangle-return)
  13
  14 macro-expands to two functions that define lisp-name and (setf ,lisp-name)
  15 and calls the functions mangle-arg and mangle-return on outgoing and incoming
  16 data resp.
  17
  18 Parameters passed to the function thus defined (lisp-name)
  19 are all passed directly into mangle-arg.  mangle-arg should return an
  20 alien pointer  - this is passed unscathed to the foreign routine, so
  21 wants to have type (* t).  Note that even for options that have
  22 integer arguments, this is still a pointer to said integer.
  23
  24 size is the size of the buffer that the return of mangle-arg points
  25 to, and also of the buffer that we should allocate for getsockopt
  26 to write into.
  27
  28 mangle-return is called with an alien buffer and should turn it into
  29 something that the caller will want.
  30
  31 Code for options that not every system has should be conditionalised:
  32
  33  (if (boundp 'sockint::IP_RECVIF)
  34      (define-socket-option so-receive-interface nil (getprotobyname "ip")
  35        sockint::IP_RECVIF  ...  ))
  36 |#
  37
  38 (defmacro define-socket-option
  39     (lisp-name documentation
  40      level number buffer-type mangle-arg mangle-return mangle-setf-buffer
  41      &optional features info)
  42   (let ((find-level
  43          (if (numberp (eval level))
  44              level
  45              `(get-protocol-by-name ,(string-downcase (symbol-name level)))))
  46         (supportedp (or (null features) (sb-int:featurep features))))
  47     `(progn
  48       (export ',lisp-name)
  49       (defun ,lisp-name (socket)
  50         ,@(when documentation (list (concatenate 'string documentation " " info)))
  51         ,(if supportedp
  52              `(sb-alien:with-alien ((size sb-alien:int)
  53                                       (buffer ,buffer-type))
  54                   (setf size (sb-alien:alien-size ,buffer-type :bytes))
  55                   (if (= -1 (sockint::getsockopt (socket-file-descriptor socket)
  56                                                  ,find-level ,number
  57                                                  (sb-alien:addr buffer)
  58                                                  (sb-alien:addr size)))
  59                       (socket-error "getsockopt")
  60                       (,mangle-return buffer size)))
  61              `(error 'unsupported-operator
  62                :format-control "Socket option ~S is not supported in this platform."
  63                :format-arguments (list ',lisp-name))))
  64       (defun (setf ,lisp-name) (new-val socket)
  65         ,(if supportedp
  66              `(sb-alien:with-alien ((buffer ,buffer-type))
  67                   (setf buffer ,(if mangle-arg
  68                                     `(,mangle-arg new-val)
  69                                     `new-val))
  70                   (when (= -1 (sockint::setsockopt (socket-file-descriptor socket)
  71                                                    ,find-level ,number
  72                                                    (,mangle-setf-buffer buffer)
  73                                                    ,(if (eql buffer-type 'sb-alien:c-string)
  74                                                         `(length new-val)
  75                                                         `(sb-alien:alien-size ,buffer-type :bytes))))
  76                     (socket-error "setsockopt")))
  77              `(error 'unsupported-operator
  78                :format-control "Socket option ~S is not supported on this platform."
  79                :format-arguments (list ',lisp-name)))))))
  80
  81 ;;; sockopts that have integer arguments
  82
  83 (defun foreign-int-to-integer (buffer size)
  84   (assert (= size (sb-alien:alien-size sb-alien:int :bytes)))
  85   buffer)
  86
  87 (defmacro define-socket-option-int (name level number &optional features (info ""))
  88   `(define-socket-option ,name nil ,level ,number
  89      sb-alien:int nil foreign-int-to-integer sb-alien:addr ,features ,info))
  90
  91 (define-socket-option-int
  92   sockopt-receive-low-water sockint::sol-socket sockint::so-rcvlowat)
  93 (define-socket-option-int
  94   sockopt-send-low-water sockint::sol-socket sockint::so-sndlowat)
  95 (define-socket-option-int
  96   sockopt-type sockint::sol-socket sockint::so-type)
  97 (define-socket-option-int
  98   sockopt-send-buffer sockint::sol-socket sockint::so-sndbuf)
  99 (define-socket-option-int
 100   sockopt-receive-buffer sockint::sol-socket sockint::so-rcvbuf)
 101 (define-socket-option-int
 102   sockopt-priority sockint::sol-socket sockint::so-priority :linux
 103   "Available only on Linux.")
 104
 105 ;;; boolean options are integers really
 106
 107 (defun foreign-int-to-bool (x size)
 108   (if (zerop (foreign-int-to-integer x size))
 109       nil
 110       t))
 111
 112 (defun bool-to-foreign-int (val)
 113   (if val 1 0))
 114
 115 (defmacro define-socket-option-bool (name level c-name &optional features (info ""))
 116   `(define-socket-option ,name
 117     ,(format nil "~@<Return the value of the ~A socket option for SOCKET. ~
 118                  This can also be updated with SETF.~:@>"
 119              (symbol-name c-name))
 120     ,level ,c-name
 121     sb-alien:int bool-to-foreign-int foreign-int-to-bool sb-alien:addr
 122     ,features ,info))
 123
 124 (define-socket-option-bool
 125   sockopt-reuse-address sockint::sol-socket sockint::so-reuseaddr)
 126 (define-socket-option-bool
 127   sockopt-keep-alive sockint::sol-socket sockint::so-keepalive)
 128 (define-socket-option-bool
 129   sockopt-oob-inline sockint::sol-socket sockint::so-oobinline)
 130 (define-socket-option-bool
 131   sockopt-bsd-compatible sockint::sol-socket sockint::so-bsdcompat :linux
 132   "Available only on Linux.")
 133 (define-socket-option-bool
 134   sockopt-pass-credentials sockint::sol-socket sockint::so-passcred :linux
 135   "Available only on Linux.")
 136 (define-socket-option-bool
 137   sockopt-debug sockint::sol-socket sockint::so-debug)
 138 (define-socket-option-bool
 139   sockopt-dont-route sockint::sol-socket sockint::so-dontroute)
 140 (define-socket-option-bool
 141   sockopt-broadcast sockint::sol-socket sockint::so-broadcast)
 142
 143 (define-socket-option-bool sockopt-tcp-nodelay :tcp sockint::tcp-nodelay)
 144
 145 (defun identity-1 (x &rest args)
 146   (declare (ignore args))
 147   x)
 148
 149 (define-socket-option sockopt-bind-to-device nil sockint::sol-socket
 150   sockint::so-bindtodevice sb-alien:c-string identity identity-1 identity
 151   :linux "Available only on Linux")
 152
 153 ;;; other kinds of socket option
 154
 155 ;;; so_peercred takes a ucre structure
 156 ;;; so_linger struct linger {
 157 ;                  int   l_onoff;    /* linger active */
 158 ;                  int   l_linger;   /* how many seconds to linger for */
 159 ;              };
 160
 161 #|
 162
 163 (sockopt-reuse-address 2)
 164
 165 (defun echo-server ()
 166   (let ((s (make-inet-socket :stream (get-protocol-by-name "tcp"))))
 167     (setf (sockopt-reuse-address s) t)
 168     (setf (sockopt-bind-to-device s) "lo")
 169     (socket-bind s (make-inet-address "127.0.0.1") 3459)
 170     (socket-listen s 5)
 171     (dotimes (i 10)
 172       (let* ((s1 (socket-accept s))
 173              (stream (socket-make-stream s1 :input t :output t :buffering :none)))
 174         (let ((line (read-line stream)))
 175           (format t "got one ~A ~%" line)
 176           (format stream "~A~%" line))
 177         (close stream)))))
 178
 179 NIL
 180 |#
 181