;;; -*- Log: code.log; Package: extensions -*- ;;; ;;; ********************************************************************** ;;; This code was written as part of the CMU Common Lisp project at ;;; Carnegie Mellon University, and has been placed in the public domain. ;;; If you want to use this code or any part of CMU Common Lisp, please contact ;;; Scott Fahlman or slisp-group@cs.cmu.edu. ;;; (ext:file-comment "$Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/code/internet.lisp,v 1.8 1992/02/16 13:53:47 wlott Exp $") ;;; ;;; ********************************************************************** ;;; ;;; This file contains an interface to internet domain sockets. ;;; ;;; Written by William Lott. ;;; (in-package "EXTENSIONS") (use-package "ALIEN") (use-package "C-CALL") (export '(htonl ntohl htons ntohs lookup-host-entry host-entry host-entry-name host-entry-aliases host-entry-addr-list host-entry-addr create-inet-socket connect-to-inet-socket create-inet-listener accept-tcp-connection close-socket ipproto-tcp ipproto-udp inaddr-any add-oob-handler remove-oob-handler remove-all-oob-handlers send-character-out-of-band)) (defconstant sock-stream 1) (defconstant sock-dgram 2) (defconstant sock-raw 3) (defconstant af-unix 1) (defconstant af-inet 2) (defconstant msg-oob 1) (defconstant msg-peek 2) (defconstant msg-dontroute 4) (defvar *internet-protocols* (list (list :stream 6 sock-stream) (list :data-gram 17 sock-dgram)) "AList of socket kinds and protocol values.") (defun internet-protocol (kind) (let ((entry (assoc kind *internet-protocols*))) (unless entry (error "Invalid kind (~S) for internet domain sockets." kind)) (values (cadr entry) (caddr entry)))) (defmacro maybe-byte-swap (var bytes) (ecase (c:backend-byte-order c:*backend*) (:big-endian var) (:little-endian (let ((ldbs nil)) (dotimes (i bytes `(logior ,@ldbs)) (push `(ash (ldb (byte 8 ,(* i 8)) ,var) ,(* (- bytes 1 i) 8)) ldbs)))))) (proclaim '(inline htonl ntohl htons ntohs)) (defun htonl (x) (maybe-byte-swap x 4)) (defun ntohl (x) (maybe-byte-swap x 4)) (defun htons (x) (maybe-byte-swap x 2)) (defun ntohs (x) (maybe-byte-swap x 2)) ;;;; Host entry operations. (defstruct host-entry name aliases addr-type addr-list) (defun host-entry-addr (host) (declare (type host-entry host)) (car (host-entry-addr-list host))) (def-alien-type inet-sockaddr (struct nil (family short) (port unsigned-short) (addr unsigned-long) (zero (array char 8)))) (def-alien-type hostent (struct nil (name c-string) (aliases (* c-string)) (addrtype int) (length int) (addr-list (* (unsigned 32))))) (def-alien-routine "gethostbyname" (* hostent) (name c-string)) (def-alien-routine "gethostbyaddr" (* hostent) (addr unsigned-long :copy) (len int) (type int)) (defmacro listify-c-array (array) `(do ((results nil (cons (deref ,array index) results)) (index 0 (1+ index))) ((zerop (deref (cast ,array (* (unsigned 32))) index)) (nreverse results)))) (defun lookup-host-entry (host) (if (typep host 'host-entry) host (with-alien ((hostent (* hostent) (etypecase host (string (gethostbyname host)) ((unsigned-byte 32) (gethostbyaddr host 4 af-inet))))) (unless (zerop (sap-int (alien-sap hostent))) (make-host-entry :name (slot hostent 'name) :aliases (listify-c-array (slot hostent 'aliases)) :addr-type (slot hostent 'addrtype) :addr-list (listify-c-array (slot hostent 'addr-list))))))) (defun create-inet-socket (&optional (kind :stream)) (multiple-value-bind (proto type) (internet-protocol kind) (let ((socket (unix:unix-socket af-inet type proto))) (when (minusp socket) (error "Error creating socket: ~A" (unix:get-unix-error-msg))) socket))) (defun connect-to-inet-socket (host port &optional (kind :stream)) (let ((socket (create-inet-socket kind)) (hostent (or (lookup-host-entry host) (error "Unknown host: ~S." host)))) (with-alien ((sockaddr inet-sockaddr)) (setf (slot sockaddr 'family) af-inet) (setf (slot sockaddr 'port) (htons port)) (setf (slot sockaddr 'addr) (host-entry-addr hostent)) (when (minusp (unix:unix-connect socket (alien-sap sockaddr) (alien-size inet-sockaddr :bytes))) (unix:unix-close socket) (error "Error connecting socket to [~A:~A]: ~A" (host-entry-name hostent) port (unix:get-unix-error-msg))) socket))) (defun create-inet-listener (port &optional (kind :stream)) (let ((socket (create-inet-socket kind))) (with-alien ((sockaddr inet-sockaddr)) (setf (slot sockaddr 'family) af-inet) (setf (slot sockaddr 'port) (htons port)) (setf (slot sockaddr 'addr) 0) (when (minusp (unix:unix-bind socket (alien-sap sockaddr) (alien-size inet-sockaddr :bytes))) (unix:unix-close socket) (error "Error binding socket to port ~a: ~a" port (unix:get-unix-error-msg)))) (when (eq kind :stream) (when (minusp (unix:unix-listen socket 5)) (unix:unix-close socket) (error "Error listening to socket: ~A" (unix:get-unix-error-msg)))) socket)) (defun accept-tcp-connection (unconnected) (declare (fixnum unconnected)) (with-alien ((sockaddr inet-sockaddr)) (let ((connected (unix:unix-accept unconnected (alien-sap sockaddr) (alien-size inet-sockaddr :bytes)))) (when (minusp connected) (error "Error accepting a connection: ~A" (unix:get-unix-error-msg))) (values connected (slot sockaddr 'addr))))) (defun close-socket (socket) (multiple-value-bind (ok err) (unix:unix-close socket) (unless ok (error "Error closing socket: ~A" (unix:get-unix-error-msg err)))) (undefined-value)) ;;;; Out of Band Data. ;;; Two level AList. First levels key is the file descriptor, second levels ;;; key is the character. The datum is the handler to call. (defvar *oob-handlers* nil) ;;; SIGURG-HANDLER -- internal ;;; ;;; Routine that gets called whenever out-of-band data shows up. Checks each ;;; file descriptor for any oob data. If there is any, look for a handler for ;;; that character. If any are found, funcall them. (defun sigurg-handler (signo code scp) (declare (ignore signo code scp)) (let ((buffer (make-string 1)) (handled nil)) (declare (simple-string buffer)) (dolist (handlers *oob-handlers*) (declare (list handlers)) (cond ((minusp (unix:unix-recv (car handlers) buffer 1 msg-oob)) (cerror "Ignore it" "Error recving oob data on ~A: ~A" (car handlers) (unix:get-unix-error-msg))) (t (setf handled t) (let ((char (schar buffer 0)) (handled nil)) (declare (base-char char)) (dolist (handler (cdr handlers)) (declare (list handler)) (when (eql (car handler) char) (funcall (cdr handler)) (setf handled t))) (unless handled (cerror "Ignore it" "No oob handler defined for ~S on ~A" char (car handlers))))))) (unless handled (cerror "Ignore it" "Got a SIGURG, but couldn't find any out-of-band data."))) (undefined-value)) ;;; ADD-OOB-HANDLER -- public ;;; ;;; First, check to see if we already have any handlers for this file ;;; descriptor. If so, just add this handler to them. If not, add this ;;; file descriptor to *oob-handlers*, make sure our interupt handler is ;;; installed, and that the given file descriptor is "owned" by us (so sigurg ;;; will be delivered.) (defun add-oob-handler (fd char handler) "Arange to funcall HANDLER when CHAR shows up out-of-band on FD." (declare (integer fd) (base-char char)) (let ((handlers (assoc fd *oob-handlers*))) (declare (list handlers)) (cond (handlers (push (cons char handler) (cdr handlers))) (t (push (list fd (cons char handler)) *oob-handlers*) (system:enable-interrupt unix:sigurg #'sigurg-handler) (unix:unix-fcntl fd unix:f-setown (unix:unix-getpid))))) (values)) ;;; REMOVE-OOB-HANDLER -- public ;;; ;;; Delete any handlers for the given char from the list of handlers for the ;;; given file descriptor. If there are no more, nuke the entry for the file ;;; descriptor. (defun remove-oob-handler (fd char) "Remove any handlers for CHAR on FD." (declare (integer fd) (base-char char)) (let ((handlers (assoc fd *oob-handlers*))) (declare (list handlers)) (when handlers (let ((remaining (delete char handlers :test #'eql :key #'car))) (declare (list remaining)) (if remaining (setf (cdr handlers) remaining) (setf *oob-handlers* (delete fd *oob-handlers* :test #'eql :key #'car)))))) (values)) ;;; REMOVE-ALL-OOB-HANDLERS -- public ;;; ;;; Delete the entry for the given file descriptor. (defun remove-all-oob-handlers (fd) "Remove all handlers for FD." (declare (integer fd)) (setf *oob-handlers* (delete fd *oob-handlers* :test #'eql :key #'car)) (values)) ;;; SEND-CHARACTER-OUT-OF-BAND -- public ;;; ;;; Sends CHAR across FD out of band. (defun send-character-out-of-band (fd char) (declare (integer fd) (base-char char)) (let ((buffer (make-string 1 :initial-element char))) (declare (simple-string buffer)) (when (minusp (unix:unix-send fd buffer 1 msg-oob)) (error "Error sending ~S OOB to across ~A: ~A" char fd (unix:get-unix-error-msg)))))