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RST when we're not listening on a port

This commit is contained in:
Tony Garnock-Jones 2014-06-20 00:08:43 -04:00
parent 82c5ea71ed
commit 6a3bafe082
1 changed files with 25 additions and 14 deletions
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39
tcp.rkt
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@ -299,7 +299,8 @@
inbound ;; buffer
syn-acked? ;; boolean
latest-activity-time ;; from current-inexact-milliseconds
local-peer-seen?) ;; boolean
local-peer-seen? ;; boolean
listener-listening?) ;; boolean
#:transparent)
(define transmit-check-interval-msec 100)
@ -344,19 +345,25 @@
(define (seq> a b)
(< (seq- a b) #x80000000))
(define local-peer-detector (pub (tcp-channel src dst ?) #:level 1))
(define listener-detector (pub (tcp-channel ? (tcp-listener dst-port) ?) #:level 3))
;; ^ see comment in spawn-tcp-port-allocator for why level 3 instead of level 2
;; ConnState -> Gestalt
(define (compute-gestalt s)
(define worldward-facing-gestalt
(gestalt-union (sub (tcp-packet #t src-ip src-port dst-ip dst-port ? ? ? ? ? ?))
(pub (tcp-packet #f dst-ip dst-port src-ip src-port ? ? ? ? ? ?))))
(define appward-facing-gestalt
(if (conn-state-syn-acked? s)
(gestalt-union (if (not (buffer-finished? (conn-state-inbound s)))
(pub (tcp-channel src dst ?))
(gestalt-empty))
(sub (tcp-channel dst src ?))
(pub (tcp-channel src dst ?) #:level 1))
(gestalt-empty)))
(gestalt-union
local-peer-detector
listener-detector
(if (conn-state-syn-acked? s)
(gestalt-union (sub (tcp-channel dst src ?))
(if (not (buffer-finished? (conn-state-inbound s)))
(pub (tcp-channel src dst ?))
(gestalt-empty)))
(gestalt-empty))))
(gestalt-union (sub (timer-expired (timer-name ?) ?))
worldward-facing-gestalt
appward-facing-gestalt))
@ -501,7 +508,7 @@
#""))
(quit))))
;; ConnState -> ConnState
;; ConnState -> Transition
(define (close-outbound-stream s)
(transition
(struct-copy conn-state s
@ -514,21 +521,24 @@
(match e
[(routing-update g)
(log-info "State vector routing-update:\n~a" (gestalt->pretty-string g))
(define local-peer-present? (not (gestalt-empty? g)))
(define local-peer-present? (not (gestalt-empty? (gestalt-filter g local-peer-detector))))
(define listening? (not (gestalt-empty? (gestalt-filter g listener-detector))))
(define new-s (struct-copy conn-state s [listener-listening? listening?]))
(cond
[(and local-peer-present? (not (conn-state-local-peer-seen? s)))
(transition (struct-copy conn-state s [local-peer-seen? #t]) '())]
(transition (struct-copy conn-state new-s [local-peer-seen? #t]) '())]
[(and (not local-peer-present?) (conn-state-local-peer-seen? s))
(log-info "Closing outbound stream.")
(sequence-transitions (close-outbound-stream s)
(sequence-transitions (close-outbound-stream new-s)
(send-outbound old-ackn)
bump-activity-time
quit-when-done)]
[else #f])]
[else (transition new-s '())])]
[(message (tcp-packet #t _ _ _ _ seqn ackn flags window options data) _ _)
(define expected (next-expected-seqn s))
(if (and (not expected) ;; no syn yet
(not (set-member? flags 'syn))) ;; and this isn't it
(or (not (set-member? flags 'syn)) ;; and this isn't it
(not (conn-state-listener-listening? s)))) ;; or it is, but no-one local cares
(reset ackn ;; this is *our* seqn
seqn ;; this is what we should acknowledge...
(set-member? flags 'fin) ;; ... +1, if fin is set
@ -575,6 +585,7 @@
(buffer #"" #f inbound-buffer-limit #f)
#f
(current-inexact-milliseconds)
#f
#f)))
(spawn state-vector-behavior
state0