201 lines
7.5 KiB
Racket
201 lines
7.5 KiB
Racket
#lang syndicate/core
|
|
|
|
(require racket/exn)
|
|
(require (prefix-in tcp: racket/tcp))
|
|
(require (only-in racket/port read-bytes-avail!-evt))
|
|
(require syndicate/demand-matcher)
|
|
(require syndicate/protocol/advertise)
|
|
|
|
(require racket/unit)
|
|
(require net/tcp-sig)
|
|
(require net/tcp-unit)
|
|
|
|
(provide (struct-out tcp-address)
|
|
(struct-out tcp-handle)
|
|
(struct-out tcp-listener)
|
|
(struct-out tcp-channel)
|
|
spawn-tcp-driver)
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;; Protocol messages
|
|
|
|
(struct tcp-address (host port) #:prefab)
|
|
(struct tcp-handle (id) #:prefab)
|
|
(struct tcp-listener (port) #:prefab)
|
|
|
|
(struct tcp-channel (source destination subpacket) #:prefab)
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;; Ground-level communication messages
|
|
|
|
(struct tcp-accepted (remote-addr local-addr cin cout) #:prefab)
|
|
;; tcp-channel does double-duty as a ground-level message as well
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;; Driver
|
|
|
|
(define (spawn-tcp-driver)
|
|
(list (spawn-demand-matcher (advertise (observe (tcp-channel ? (?! (tcp-listener ?)) ?)))
|
|
(advertise (advertise (tcp-channel ? (?! (tcp-listener ?)) ?)))
|
|
spawn-tcp-listener
|
|
#:name 'drivers/tcp:dm:listener)
|
|
(spawn-demand-matcher (advertise (tcp-channel (?! (tcp-handle ?)) (?! (tcp-address ? ?)) ?))
|
|
(observe (tcp-channel (?! (tcp-handle ?)) (?! (tcp-address ? ?)) ?))
|
|
spawn-tcp-connection
|
|
(lambda (local-addr remote-addr)
|
|
(log-debug "Outbound TCP connection closed: ~v -> ~v"
|
|
local-addr
|
|
remote-addr))
|
|
#:name 'drivers/tcp:dm:connect)))
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;; Listener
|
|
|
|
(struct listener-state (control-ch server-addr) #:transparent)
|
|
|
|
(define (tcp-listener-thread control-ch listener server-addr)
|
|
(let loop ((blocked? #t))
|
|
(sync (handle-evt control-ch
|
|
(match-lambda
|
|
['unblock (loop #f)]
|
|
['quit (void)]))
|
|
(if blocked?
|
|
never-evt
|
|
(handle-evt (tcp:tcp-accept-evt listener)
|
|
(lambda (cin+cout)
|
|
(match-define (list cin cout) cin+cout)
|
|
(define-values (local-hostname local-port remote-hostname remote-port)
|
|
(tcp:tcp-addresses cin #t))
|
|
(send-ground-message
|
|
(tcp-accepted (tcp-address remote-hostname remote-port)
|
|
server-addr
|
|
cin
|
|
cout))
|
|
(loop blocked?))))))
|
|
(tcp:tcp-close listener))
|
|
|
|
(define (tcp-listener-behavior e state)
|
|
(match e
|
|
[(? patch? p)
|
|
(define ch (listener-state-control-ch state))
|
|
(cond [(patch/removed? p) (channel-put ch 'quit) (quit)]
|
|
[(patch/added? p) (channel-put ch 'unblock) #f]
|
|
[else #f])]
|
|
[(message (inbound (tcp-accepted remote-addr _ cin cout)))
|
|
(transition state (spawn-connection (listener-state-server-addr state)
|
|
remote-addr
|
|
cin
|
|
cout))]
|
|
[_ #f]))
|
|
|
|
(define (spawn-tcp-listener server-addr)
|
|
(match-define (tcp-listener port) server-addr)
|
|
(define listener (tcp:tcp-listen port 128 #t))
|
|
(define control-ch (make-channel))
|
|
(thread (lambda () (tcp-listener-thread control-ch listener server-addr)))
|
|
(actor #:name (list 'drivers/tcp:listen port)
|
|
#:assertions*
|
|
(patch->initial-assertions
|
|
(patch-seq
|
|
(sub (advertise (observe (tcp-channel ? server-addr ?)))) ;; monitor peer
|
|
(pub (advertise (tcp-channel ? server-addr ?))) ;; declare we might make connections
|
|
(sub (inbound (tcp-accepted ? server-addr ? ?))) ;; events from driver thread
|
|
))
|
|
tcp-listener-behavior
|
|
(listener-state control-ch server-addr)
|
|
(void)))
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;; Outbound Connection
|
|
|
|
(define (spawn-tcp-connection local-addr remote-addr)
|
|
(match-define (tcp-address remote-hostname remote-port) remote-addr)
|
|
(define-values (cin cout)
|
|
(with-handlers ([exn:fail? (lambda (e)
|
|
;; TODO: it'd be nice to somehow
|
|
;; communicate the actual error to
|
|
;; the local peer.
|
|
(log-error "~a" (exn->string e))
|
|
(define o (open-output-string))
|
|
(close-output-port o)
|
|
(values (open-input-string "")
|
|
o))])
|
|
(tcp:tcp-connect remote-hostname remote-port)))
|
|
(spawn-connection local-addr remote-addr cin cout))
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;; Connection
|
|
|
|
(struct connection-state (control-ch cout) #:transparent)
|
|
|
|
(define (read-bytes-avail-evt len input-port)
|
|
(guard-evt
|
|
(lambda ()
|
|
(let ([bstr (make-bytes len)])
|
|
(handle-evt
|
|
(read-bytes-avail!-evt bstr input-port)
|
|
(lambda (v)
|
|
(if (number? v)
|
|
(if (= v len) bstr (subbytes bstr 0 v))
|
|
v)))))))
|
|
|
|
(define (tcp-connection-thread remote-addr local-addr control-ch cin)
|
|
(let loop ((blocked? #t))
|
|
(sync (handle-evt control-ch
|
|
(match-lambda
|
|
['unblock (loop #f)]
|
|
['quit (void)]))
|
|
(if blocked?
|
|
never-evt
|
|
(handle-evt (read-bytes-avail-evt 32768 cin)
|
|
(lambda (eof-or-bs)
|
|
(send-ground-message (tcp-channel remote-addr local-addr eof-or-bs))
|
|
(loop (or blocked? (eof-object? eof-or-bs))))))))
|
|
(close-input-port cin))
|
|
|
|
(define (shutdown-connection! state)
|
|
(match-define (connection-state control-ch cout) state)
|
|
(when control-ch (channel-put control-ch 'quit))
|
|
(when cout (close-output-port cout)))
|
|
|
|
(define (tcp-connection e state)
|
|
(with-handlers [((lambda (exn) #t)
|
|
(lambda (exn)
|
|
(shutdown-connection! state)
|
|
(raise exn)))]
|
|
(match e
|
|
[(message (inbound (tcp-channel remote-addr local-addr (? eof-object?))))
|
|
(shutdown-connection! state)
|
|
(quit)]
|
|
[(message (inbound (tcp-channel remote-addr local-addr (? bytes? bs))))
|
|
(transition state (message (tcp-channel remote-addr local-addr bs)))]
|
|
[(message (tcp-channel _ _ bs))
|
|
(if (string? bs)
|
|
(write-string bs (connection-state-cout state))
|
|
(write-bytes bs (connection-state-cout state)))
|
|
(flush-output (connection-state-cout state))
|
|
#f]
|
|
[(? patch? p)
|
|
(define ch (connection-state-control-ch state))
|
|
(cond [(patch/removed? p) (shutdown-connection! state) (quit)]
|
|
[(patch/added? p) (channel-put ch 'unblock) #f]
|
|
[else #f])]
|
|
[#f #f])))
|
|
|
|
(define (spawn-connection local-addr remote-addr cin cout)
|
|
(define control-ch (make-channel))
|
|
(thread (lambda () (tcp-connection-thread remote-addr local-addr control-ch cin)))
|
|
(actor #:name (list 'drivers/tcp:connect local-addr remote-addr)
|
|
tcp-connection
|
|
(connection-state control-ch cout)
|
|
(patch-seq
|
|
(sub (observe (tcp-channel remote-addr local-addr ?))) ;; monitor peer
|
|
(pub (tcp-channel remote-addr local-addr ?)) ;; may send segments to peer
|
|
(sub (tcp-channel local-addr remote-addr ?)) ;; want segments from peer
|
|
(sub (inbound (tcp-channel remote-addr local-addr ?))) ;; segments from driver thread
|
|
)))
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
|
|
(spawn-tcp-driver)
|