Copy monolithic netstack implementation to subdir, for future reference
This commit is contained in:
Tony Garnock-Jones
parent
4357424e78
commit
b2d5a3f74d
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@ -0,0 +1,7 @@
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all:
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run:
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raco make main.rkt && racket main.rkt
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clean:
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find . -name compiled -type d | xargs rm -rf
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# TCP/IP Stack
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## Linux Firewall Configuration
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Imagine a setup where the machine you are running this code has IP
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192.168.1.10. This code claims 192.168.1.222 for itself. Now, pinging
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192.168.1.222 from some other machine, say 192.168.1.99, will cause
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the local kernel to receive the pings and then *forward them on to
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192.168.1.222*, which because of the gratuitous ARP announcement, it
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knows to be on its own Ethernet MAC address. This causes the ping
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requests to repeat endlessly, each time with one lower TTL.
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One approach to solving the problem is to prevent the kernel from
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forwarding packets addressed to 192.168.1.222. To do this,
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sudo iptables -I FORWARD -d 192.168.1.222 -j DROP
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Ideas on TCP unit testing:
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<https://www.snellman.net/blog/archive/2015-07-09-unit-testing-a-tcp-stack/>
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Check behaviour around TCP zero-window probing. Is the correct
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behaviour already a consequence of the way `send-outbound` works?
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Do something smarter with TCP timers and RTT estimation than the
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nothing that's already being done.
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TCP options negotiation.
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- SACK
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- Window scaling
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Bugs:
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- RST kills a connection even if its sequence number is bogus. Check
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to make sure it's in the window. (See
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http://static.googleusercontent.com/media/research.google.com/en//pubs/archive/41848.pdf
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and RFC 5961)
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#lang racket/base
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;; ARP protocol, http://tools.ietf.org/html/rfc826
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;; Only does ARP-over-ethernet.
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(provide (struct-out arp-query)
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(struct-out arp-assertion)
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(struct-out arp-interface)
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spawn-arp-driver)
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(require racket/set)
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(require racket/match)
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(require syndicate/monolithic)
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(require syndicate/drivers/timer)
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(require syndicate/demand-matcher)
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(require bitsyntax)
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(require "dump-bytes.rkt")
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(require "configuration.rkt")
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(require "ethernet.rkt")
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(struct arp-query (protocol protocol-address interface link-address) #:prefab)
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(struct arp-assertion (protocol protocol-address interface-name) #:prefab)
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(struct arp-interface (interface-name) #:prefab)
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(struct arp-interface-up (interface-name) #:prefab)
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(define ARP-ethertype #x0806)
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(define cache-entry-lifetime-msec (* 14400 1000))
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(define wakeup-interval 5000)
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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(define (spawn-arp-driver)
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(spawn-demand-matcher (arp-interface (?!))
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(arp-interface-up (?!))
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spawn-arp-interface))
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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(struct cache-key (protocol address) #:transparent)
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(struct cache-value (expiry interface address) #:transparent)
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(struct state (cache queries assertions) #:transparent)
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(define (spawn-arp-interface interface-name)
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(log-info "spawn-arp-interface ~v" interface-name)
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(lookup-ethernet-hwaddr (assertion (arp-interface-up interface-name))
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interface-name
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(lambda (hwaddr) (spawn-arp-interface* interface-name hwaddr))))
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(define (spawn-arp-interface* interface-name hwaddr)
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(log-info "spawn-arp-interface* ~v ~v" interface-name hwaddr)
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(define interface (ethernet-interface interface-name hwaddr))
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(define (expire-cache cache)
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(define now (current-inexact-milliseconds))
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(define (not-expired? v) (< now (cache-value-expiry v)))
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(for/hash [((k v) (in-hash cache)) #:when (not-expired? v)]
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(values k v)))
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(define timer-key (list 'arp interface-name))
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(define (set-wakeup-alarm)
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(message (set-timer timer-key wakeup-interval 'relative)))
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(define (compute-gestalt cache)
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(scn/union (subscription (timer-expired timer-key ?))
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(subscription interface)
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(subscription (ethernet-packet-pattern interface-name #t ARP-ethertype))
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(assertion (arp-interface-up interface-name))
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(subscription (arp-assertion ? ? interface-name))
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(subscription (observe (arp-query ? ? interface ?)))
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(for/fold [(g trie-empty)] [((k v) (in-hash cache))]
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(assertion-set-union g (assertion (arp-query (cache-key-protocol k)
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(cache-key-address k)
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(cache-value-interface v)
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(cache-value-address v)))))))
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(define (build-packet dest-mac ptype oper sender-ha sender-pa target-ha target-pa)
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(define hlen (bytes-length target-ha))
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(define plen (bytes-length target-pa))
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(define packet (bit-string->bytes
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(bit-string (1 :: integer bytes 2)
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(ptype :: integer bytes 2)
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hlen
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plen
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(oper :: integer bytes 2)
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(sender-ha :: binary bytes hlen)
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(sender-pa :: binary bytes plen)
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(target-ha :: binary bytes hlen)
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(target-pa :: binary bytes plen))))
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(ethernet-packet interface
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#f
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hwaddr
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dest-mac
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ARP-ethertype
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packet))
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(define (analyze-incoming-packet source destination body s)
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(bit-string-case body
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([ (= 1 :: integer bytes 2)
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(ptype :: integer bytes 2)
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hlen
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plen
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(oper :: integer bytes 2)
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(sender-hardware-address0 :: binary bytes hlen)
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(sender-protocol-address0 :: binary bytes plen)
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(target-hardware-address0 :: binary bytes hlen)
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(target-protocol-address0 :: binary bytes plen)
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(:: binary) ;; The extra zeros exist because ethernet packets
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;; have a minimum size. This is, in part, why
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;; IPv4 headers have a total-length field, so
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;; that the zero padding can be removed.
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]
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(let ()
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(define sender-protocol-address (bit-string->bytes sender-protocol-address0))
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(define sender-hardware-address (bit-string->bytes sender-hardware-address0))
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(define target-protocol-address (bit-string->bytes target-protocol-address0))
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(define learned-key (cache-key ptype sender-protocol-address))
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(when (and (set-member? (state-queries s) learned-key) ;; it is relevant to our interests
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(not (equal? sender-hardware-address
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(cache-value-address (hash-ref (state-cache s)
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learned-key
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(lambda ()
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(cache-value #f #f #f)))))))
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(log-info "~a ARP Adding ~a = ~a to cache"
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interface-name
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(pretty-bytes sender-protocol-address)
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(pretty-bytes sender-hardware-address)))
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(define cache (hash-set (expire-cache (state-cache s))
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learned-key
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(cache-value (+ (current-inexact-milliseconds)
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cache-entry-lifetime-msec)
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interface
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sender-hardware-address)))
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(transition (struct-copy state s [cache cache])
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(list
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(case oper
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[(1) ;; request
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(if (set-member? (state-assertions s)
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(cache-key ptype target-protocol-address))
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(begin
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(log-info "~a ARP answering request for ~a/~a"
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interface-name
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ptype
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(pretty-bytes target-protocol-address))
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(message (build-packet sender-hardware-address
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ptype
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2 ;; reply
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hwaddr
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target-protocol-address
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sender-hardware-address
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sender-protocol-address)))
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'())]
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[(2) '()] ;; reply
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[else '()])
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(compute-gestalt cache)))))
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(else #f)))
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(define queries-projection (observe (arp-query (?!) (?!) ? ?)))
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(define (gestalt->queries g)
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(for/set [(e (in-set (trie-project/set #:take 2 g queries-projection)))]
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(match-define (list ptype pa) e)
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(cache-key ptype pa)))
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(define assertions-projection (arp-assertion (?!) (?!) ?))
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(define (gestalt->assertions g)
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(for/set [(e (in-set (trie-project/set #:take 2 g assertions-projection)))]
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(match-define (list ptype pa) e)
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(cache-key ptype pa)))
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(define (analyze-gestalt g s)
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(define new-assertions (gestalt->assertions g))
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(define added-assertions (set-subtract new-assertions (state-assertions s)))
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(define new-s (struct-copy state s [queries (gestalt->queries g)] [assertions new-assertions]))
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(if (trie-empty? (project-assertions g (arp-interface interface-name)))
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(quit)
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(transition new-s
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(list
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(for/list [(a (in-set added-assertions))]
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(log-info "~a ARP Announcing ~a as ~a"
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interface-name
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(pretty-bytes (cache-key-address a))
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(pretty-bytes hwaddr))
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(message (build-packet broadcast-ethernet-address
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(cache-key-protocol a)
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2 ;; reply -- gratuitous announcement
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hwaddr
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(cache-key-address a)
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hwaddr
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(cache-key-address a))))))))
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(define (send-questions s)
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(define unanswered-queries
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(set-subtract (state-queries s) (list->set (hash-keys (state-cache s)))))
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(define (some-asserted-pa ptype)
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(match (filter (lambda (k) (equal? (cache-key-protocol k) ptype))
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(set->list (state-assertions s)))
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['() #f]
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[(list* k _) (cache-key-address k)]))
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(transition s
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(for/list [(q (in-set unanswered-queries))]
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(define pa (some-asserted-pa (cache-key-protocol q)))
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(log-info "~a ARP Asking for ~a from ~a"
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interface-name
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(pretty-bytes (cache-key-address q))
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(and pa (pretty-bytes pa)))
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(when pa
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(message (build-packet broadcast-ethernet-address
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(cache-key-protocol q)
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1 ;; request
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hwaddr
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pa
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zero-ethernet-address
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(cache-key-address q)))))))
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(list (set-wakeup-alarm)
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(spawn (lambda (e s)
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;; (log-info "ARP ~a ~a: ~v // ~v" interface-name (pretty-bytes hwaddr) e s)
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(match e
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[(scn g)
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(sequence-transitions (analyze-gestalt g s)
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send-questions)]
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[(message (ethernet-packet _ _ source destination _ body))
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(analyze-incoming-packet source destination body s)]
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[(message (timer-expired _ _))
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(define new-s (struct-copy state s
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[cache (expire-cache (state-cache s))]))
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(sequence-transitions (transition new-s
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(list (set-wakeup-alarm)
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(compute-gestalt (state-cache new-s))))
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send-questions)]
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[_ #f]))
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(state (hash) (set) (set))
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(compute-gestalt (hash)))))
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@ -0,0 +1,52 @@
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#lang racket/base
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(provide ones-complement-sum16 ip-checksum)
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(require bitsyntax)
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(require "dump-bytes.rkt")
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(define (ones-complement-+16 a b)
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(define c (+ a b))
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(bitwise-and #xffff (+ (arithmetic-shift c -16) c)))
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(define (ones-complement-sum16 bs)
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(bit-string-case bs
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([ (n :: integer bytes 2) (rest :: binary) ]
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(ones-complement-+16 n (ones-complement-sum16 rest)))
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([ odd-byte ]
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(arithmetic-shift odd-byte 8))
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([ ]
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0)))
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(define (ones-complement-negate16-safely x)
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(define r (bitwise-and #xffff (bitwise-not x)))
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(if (= r 0) #xffff r))
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(define (ip-checksum offset blob #:pseudo-header [pseudo-header #""])
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(bit-string-case blob
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([ (prefix :: binary bytes offset)
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(:: binary bytes 2)
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(suffix :: binary) ]
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;; (log-info "Packet pre checksum:\n~a" (dump-bytes->string blob))
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(define result (ones-complement-+16
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(ones-complement-sum16 pseudo-header)
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(ones-complement-+16 (ones-complement-sum16 prefix)
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(ones-complement-sum16 suffix))))
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;; (log-info "result: ~a" (number->string result 16))
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(define checksum (ones-complement-negate16-safely result))
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;; (log-info "Checksum ~a" (number->string checksum 16))
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(define final-packet (bit-string (prefix :: binary)
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(checksum :: integer bytes 2)
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(suffix :: binary)))
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;; (log-info "Packet with checksum:\n~a" (dump-bytes->string final-packet))
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final-packet)))
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(module+ test
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(require rackunit)
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(check-equal? (ones-complement-negate16-safely
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(ones-complement-sum16 (bytes #x45 #x00 #x00 #x54
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#x00 #x00 #x00 #x00
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#x40 #x01 #x00 #x00
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#xc0 #xa8 #x01 #xde
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#xc0 #xa8 #x01 #x8f)))
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#xf5eb))
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@ -0,0 +1,21 @@
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#lang racket/base
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(provide (struct-out ethernet-interface)
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(struct-out host-route)
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(struct-out gateway-route)
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(struct-out net-route)
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(struct-out route-up))
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(struct ethernet-interface (name hwaddr) #:prefab)
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;; A Route is one of
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;; - (host-route IpAddrBytes NetmaskNat InterfaceName), an own-IP route
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;; - (gateway-route NetAddrBytes NetmaskNat IpAddrBytes InterfaceName), a gateway for a subnet
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;; - (net-route NetAddrBytes NetmaskNat InterfaceName), an ethernet route for a subnet
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;; NetmaskNat in a net-route is a default route.
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(struct host-route (ip-addr netmask interface-name) #:prefab)
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(struct gateway-route (network-addr netmask gateway-addr interface-name) #:prefab)
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(struct net-route (network-addr netmask link) #:prefab)
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(struct route-up (route) #:prefab) ;; assertion: the given Route is running
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@ -0,0 +1,25 @@
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#lang racket/base
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;; Demonstration stack configuration for various hosts.
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(require racket/match)
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(require syndicate/monolithic)
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(require (only-in mzlib/os gethostname))
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(require "configuration.rkt")
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(provide spawn-demo-config)
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(define (spawn-demo-config)
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(spawn (lambda (e s) #f)
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(void)
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(match (gethostname)
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["skip"
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(scn/union (assertion (gateway-route (bytes 0 0 0 0) 0 (bytes 192 168 1 1) "en0"))
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(assertion (host-route (bytes 192 168 1 222) 24 "en0")))]
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[(or "hop" "walk")
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(scn/union (assertion (gateway-route (bytes 0 0 0 0) 0 (bytes 192 168 1 1) "wlan0"))
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(assertion (host-route (bytes 192 168 1 222) 24 "wlan0")))]
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["stockholm.ccs.neu.edu"
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(scn/union (assertion (host-route (bytes 129 10 115 94) 24 "eth0"))
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(assertion (gateway-route (bytes 0 0 0 0) 0 (bytes 129 10 115 1) "eth0")))]
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[else
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(error 'spawn-demo-config "No setup for hostname ~a" (gethostname))])))
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@ -0,0 +1,80 @@
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#lang racket/base
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;; Copyright (C) 2012 Tony Garnock-Jones <tonygarnockjones@gmail.com>
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;;
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;; dump-bytes.rkt is free software: you can redistribute it and/or modify
|
||||
;; it under the terms of the GNU General Public License as published
|
||||
;; by the Free Software Foundation, either version 3 of the License,
|
||||
;; or (at your option) any later version.
|
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;;
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||||
;; dump-bytes.rkt is distributed in the hope that it will be useful, but
|
||||
;; WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
;; General Public License for more details.
|
||||
;;
|
||||
;; You should have received a copy of the GNU General Public License
|
||||
;; along with dump-bytes.rkt. If not, see <http://www.gnu.org/licenses/>.
|
||||
|
||||
;; Pretty hex dump output of a Bytes.
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(provide dump-bytes!
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dump-bytes->string
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pretty-bytes)
|
||||
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(require (only-in bitsyntax bit-string->bytes))
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(require (only-in file/sha1 bytes->hex-string))
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|
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(define (pretty-bytes bs)
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(bytes->hex-string (bit-string->bytes bs)))
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;; Exact Exact -> String
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;; Returns the "0"-padded, width-digit hex representation of n
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(define (hex width n)
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(define s (number->string n 16))
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(define slen (string-length s))
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(cond
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((< slen width) (string-append (make-string (- width slen) #\0) s))
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||||
((= slen width) s)
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((> slen width) (substring s 0 width))))
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||||
|
||||
;; Bytes Exact -> Void
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||||
;; Prints a pretty hex/ASCII dump of bs on (current-output-port).
|
||||
(define (dump-bytes! bs0 [requested-count #f] #:base [baseaddr 0])
|
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(define bs (bit-string->bytes bs0))
|
||||
(define count (if requested-count (min requested-count (bytes-length bs)) (bytes-length bs)))
|
||||
(define clipped (subbytes bs 0 count))
|
||||
(define (dump-hex i)
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||||
(if (< i count)
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||||
(display (hex 2 (bytes-ref clipped i)))
|
||||
(display " "))
|
||||
(display #\space))
|
||||
(define (dump-char i)
|
||||
(if (< i count)
|
||||
(let ((ch (bytes-ref clipped i)))
|
||||
(if (<= 32 ch 127)
|
||||
(display (integer->char ch))
|
||||
(display #\.)))
|
||||
(display #\space)))
|
||||
(define (for-each-between f low high)
|
||||
(do ((i low (+ i 1)))
|
||||
((= i high))
|
||||
(f i)))
|
||||
(define (dump-line i)
|
||||
(display (hex 8 (+ i baseaddr)))
|
||||
(display #\space)
|
||||
(for-each-between dump-hex i (+ i 8))
|
||||
(display ": ")
|
||||
(for-each-between dump-hex (+ i 8) (+ i 16))
|
||||
(display #\space)
|
||||
(for-each-between dump-char i (+ i 8))
|
||||
(display " : ")
|
||||
(for-each-between dump-char (+ i 8) (+ i 16))
|
||||
(newline))
|
||||
(do ((i 0 (+ i 16)))
|
||||
((>= i count))
|
||||
(dump-line i)))
|
||||
|
||||
(define (dump-bytes->string bs [requested-count #f] #:base [baseaddr 0])
|
||||
(define s (open-output-string))
|
||||
(parameterize ((current-output-port s))
|
||||
(dump-bytes! bs requested-count #:base baseaddr))
|
||||
(get-output-string s))
|
||||
|
|
@ -0,0 +1,134 @@
|
|||
#lang racket/base
|
||||
;; Ethernet driver
|
||||
|
||||
(provide (struct-out ethernet-packet)
|
||||
zero-ethernet-address
|
||||
broadcast-ethernet-address
|
||||
interface-names
|
||||
spawn-ethernet-driver
|
||||
ethernet-packet-pattern
|
||||
lookup-ethernet-hwaddr)
|
||||
|
||||
(require racket/set)
|
||||
(require racket/match)
|
||||
(require racket/async-channel)
|
||||
|
||||
(require syndicate/monolithic)
|
||||
(require syndicate/demand-matcher)
|
||||
(require "on-claim.rkt")
|
||||
|
||||
(require packet-socket)
|
||||
(require bitsyntax)
|
||||
|
||||
(require "configuration.rkt")
|
||||
(require "dump-bytes.rkt")
|
||||
|
||||
(struct ethernet-packet (interface from-wire? source destination ethertype body) #:prefab)
|
||||
|
||||
(define zero-ethernet-address (bytes 0 0 0 0 0 0))
|
||||
(define broadcast-ethernet-address (bytes 255 255 255 255 255 255))
|
||||
|
||||
(define interface-names (raw-interface-names))
|
||||
(log-info "Device names: ~a" interface-names)
|
||||
|
||||
(define (spawn-ethernet-driver)
|
||||
(spawn-demand-matcher (observe (ethernet-packet (ethernet-interface (?!) ?) #t ? ? ? ?))
|
||||
(ethernet-interface (?!) ?)
|
||||
spawn-interface-tap))
|
||||
|
||||
(define (spawn-interface-tap interface-name)
|
||||
(define h (raw-interface-open interface-name))
|
||||
(define interface (ethernet-interface interface-name (raw-interface-hwaddr h)))
|
||||
(cond
|
||||
[(not h)
|
||||
(log-error "ethernet: Couldn't open interface ~v" interface-name)
|
||||
'()]
|
||||
[else
|
||||
(log-info "Opened interface ~a, yielding handle ~v" interface-name h)
|
||||
(define control-ch (make-async-channel))
|
||||
(thread (lambda () (interface-packet-read-loop interface h control-ch)))
|
||||
(spawn (lambda (e h)
|
||||
(match e
|
||||
[(scn g)
|
||||
(if (trie-empty? g)
|
||||
(begin (async-channel-put control-ch 'quit)
|
||||
(quit))
|
||||
(begin (async-channel-put control-ch 'unblock)
|
||||
#f))]
|
||||
[(message (at-meta (? ethernet-packet? p)))
|
||||
;; (log-info "Interface ~a inbound packet ~a -> ~a (type 0x~a)"
|
||||
;; (ethernet-interface-name (ethernet-packet-interface p))
|
||||
;; (pretty-bytes (ethernet-packet-source p))
|
||||
;; (pretty-bytes (ethernet-packet-destination p))
|
||||
;; (number->string (ethernet-packet-ethertype p) 16))
|
||||
;; (log-info "~a" (dump-bytes->string (ethernet-packet-body p)))
|
||||
(transition h (message p))]
|
||||
[(message (? ethernet-packet? p))
|
||||
;; (log-info "Interface ~a OUTBOUND packet ~a -> ~a (type 0x~a)"
|
||||
;; (ethernet-interface-name (ethernet-packet-interface p))
|
||||
;; (pretty-bytes (ethernet-packet-source p))
|
||||
;; (pretty-bytes (ethernet-packet-destination p))
|
||||
;; (number->string (ethernet-packet-ethertype p) 16))
|
||||
;; (log-info "~a" (dump-bytes->string (ethernet-packet-body p)))
|
||||
(raw-interface-write h (encode-ethernet-packet p))
|
||||
#f]
|
||||
[_ #f]))
|
||||
h
|
||||
(scn/union (assertion interface)
|
||||
(subscription (ethernet-packet interface #f ? ? ? ?))
|
||||
(subscription (observe (ethernet-packet interface #t ? ? ? ?)))
|
||||
(subscription (ethernet-packet interface #t ? ? ? ?) #:meta-level 1)))]))
|
||||
|
||||
(define (interface-packet-read-loop interface h control-ch)
|
||||
(define (blocked)
|
||||
(match (async-channel-get control-ch)
|
||||
['unblock (unblocked)]
|
||||
['quit (void)]))
|
||||
(define (unblocked)
|
||||
(match (async-channel-try-get control-ch)
|
||||
['unblock (unblocked)]
|
||||
['quit (void)]
|
||||
[#f
|
||||
(define p (raw-interface-read h))
|
||||
(define decoded (decode-ethernet-packet interface p))
|
||||
(when decoded (send-ground-message decoded))
|
||||
(unblocked)]))
|
||||
(blocked)
|
||||
(raw-interface-close h))
|
||||
|
||||
(define (decode-ethernet-packet interface p)
|
||||
(bit-string-case p
|
||||
([ (destination :: binary bytes 6)
|
||||
(source :: binary bytes 6)
|
||||
(ethertype :: integer bytes 2)
|
||||
(body :: binary) ]
|
||||
(ethernet-packet interface
|
||||
#t
|
||||
(bit-string->bytes source)
|
||||
(bit-string->bytes destination)
|
||||
ethertype
|
||||
(bit-string->bytes body)))
|
||||
(else #f)))
|
||||
|
||||
(define (encode-ethernet-packet p)
|
||||
(match-define (ethernet-packet _ _ source destination ethertype body) p)
|
||||
(bit-string->bytes
|
||||
(bit-string (destination :: binary bytes 6)
|
||||
(source :: binary bytes 6)
|
||||
(ethertype :: integer bytes 2)
|
||||
(body :: binary))))
|
||||
|
||||
(define (ethernet-packet-pattern interface-name from-wire? ethertype)
|
||||
(ethernet-packet (ethernet-interface interface-name ?) from-wire? ? ? ethertype ?))
|
||||
|
||||
(define (lookup-ethernet-hwaddr base-interests interface-name k)
|
||||
(on-claim #:timeout-msec 5000
|
||||
#:on-timeout (lambda ()
|
||||
(log-info "Lookup of ethernet interface ~v failed" interface-name)
|
||||
'())
|
||||
(lambda (_g hwaddrss)
|
||||
(and (not (set-empty? hwaddrss))
|
||||
(let ((hwaddr (car (set-first hwaddrss))))
|
||||
(k hwaddr))))
|
||||
base-interests
|
||||
(ethernet-interface interface-name (?!))))
|
||||
|
|
@ -0,0 +1,48 @@
|
|||
#lang syndicate/monolithic
|
||||
|
||||
(require syndicate/drivers/timer)
|
||||
(require "demo-config.rkt")
|
||||
(require "ethernet.rkt")
|
||||
(require "arp.rkt")
|
||||
(require "ip.rkt")
|
||||
(require "tcp.rkt")
|
||||
(require "udp.rkt")
|
||||
|
||||
;;(log-events-and-actions? #t)
|
||||
|
||||
(spawn-timer-driver)
|
||||
(spawn-ethernet-driver)
|
||||
(spawn-arp-driver)
|
||||
(spawn-ip-driver)
|
||||
(spawn-tcp-driver)
|
||||
(spawn-udp-driver)
|
||||
(spawn-demo-config)
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
|
||||
(let ()
|
||||
(define local-handle (tcp-handle 'httpclient))
|
||||
(define remote-handle (tcp-address "129.10.115.92" 80))
|
||||
|
||||
(spawn (lambda (e seen-peer?)
|
||||
(match e
|
||||
[(scn g)
|
||||
(define peer-present? (trie-non-empty? g))
|
||||
(if (and (not peer-present?) seen-peer?)
|
||||
(begin (printf "URL fetcher exiting.\n")
|
||||
(quit))
|
||||
(transition (or seen-peer? peer-present?)
|
||||
(message
|
||||
(tcp-channel
|
||||
local-handle
|
||||
remote-handle
|
||||
#"GET / HTTP/1.0\r\nHost: stockholm.ccs.neu.edu\r\n\r\n"))))]
|
||||
[(message (tcp-channel _ _ bs))
|
||||
(printf "----------------------------------------\n~a\n" bs)
|
||||
(printf "----------------------------------------\n")
|
||||
#f]
|
||||
[_ #f]))
|
||||
#f
|
||||
(scn/union (advertisement (tcp-channel local-handle remote-handle ?))
|
||||
(subscription (tcp-channel remote-handle local-handle ?))
|
||||
(subscription (advertise (tcp-channel remote-handle local-handle ?))))))
|
||||
|
|
@ -0,0 +1,327 @@
|
|||
#lang racket/base
|
||||
|
||||
(provide (struct-out ip-packet)
|
||||
ip-address->hostname
|
||||
ip-string->ip-address
|
||||
apply-netmask
|
||||
ip-address-in-subnet?
|
||||
gestalt->local-ip-addresses
|
||||
observe-local-ip-addresses-gestalt
|
||||
broadcast-ip-address
|
||||
spawn-ip-driver)
|
||||
|
||||
(require racket/set)
|
||||
(require racket/match)
|
||||
(require (only-in racket/string string-split))
|
||||
(require syndicate/monolithic)
|
||||
(require syndicate/drivers/timer)
|
||||
(require syndicate/demand-matcher)
|
||||
(require bitsyntax)
|
||||
|
||||
(require "dump-bytes.rkt")
|
||||
(require "configuration.rkt")
|
||||
(require "checksum.rkt")
|
||||
(require "ethernet.rkt")
|
||||
(require "arp.rkt")
|
||||
(require "on-claim.rkt")
|
||||
|
||||
(struct ip-packet (source-interface ;; string for an ethernet interface, or #f for local interfaces
|
||||
source
|
||||
destination
|
||||
protocol
|
||||
options
|
||||
body)
|
||||
#:prefab) ;; TODO: more fields
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
|
||||
(define (ip-address->hostname bs)
|
||||
(bit-string-case bs
|
||||
([ a b c d ] (format "~a.~a.~a.~a" a b c d))))
|
||||
|
||||
(define (ip-string->ip-address str)
|
||||
(list->bytes (map string->number (string-split str "."))))
|
||||
|
||||
(define (apply-netmask addr netmask)
|
||||
(bit-string-case addr
|
||||
([ (n :: integer bytes 4) ]
|
||||
(bit-string ((bitwise-and n (arithmetic-shift #x-100000000 (- netmask)))
|
||||
:: integer bytes 4)))))
|
||||
|
||||
(define (ip-address-in-subnet? addr network netmask)
|
||||
(equal? (apply-netmask network netmask)
|
||||
(apply-netmask addr netmask)))
|
||||
|
||||
(define broadcast-ip-address (bytes 255 255 255 255))
|
||||
|
||||
(define local-ip-address-projector (host-route (?!) ? ?))
|
||||
(define (gestalt->local-ip-addresses g) (trie-project/set/single g local-ip-address-projector))
|
||||
(define observe-local-ip-addresses-gestalt (subscription (host-route ? ? ?)))
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
|
||||
(define (spawn-ip-driver)
|
||||
(list
|
||||
(spawn-demand-matcher (host-route (?!) (?!) (?!))
|
||||
(route-up (host-route (?!) (?!) (?!)))
|
||||
spawn-host-route)
|
||||
(spawn-demand-matcher (gateway-route (?!) (?!) (?!) (?!))
|
||||
(route-up (gateway-route (?!) (?!) (?!) (?!)))
|
||||
spawn-gateway-route)
|
||||
(spawn-demand-matcher (net-route (?!) (?!) (?!))
|
||||
(route-up (net-route (?!) (?!) (?!)))
|
||||
spawn-net-route)))
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
;; Local IP route
|
||||
|
||||
(define (spawn-host-route my-address netmask interface-name)
|
||||
(list
|
||||
(let ((network-addr (apply-netmask my-address netmask)))
|
||||
(spawn-normal-ip-route (host-route my-address netmask interface-name)
|
||||
network-addr
|
||||
netmask
|
||||
interface-name))
|
||||
(spawn (lambda (e s)
|
||||
(match e
|
||||
[(scn (? trie-empty?)) (quit)]
|
||||
[(message (ip-packet _ peer-address _ _ _ body))
|
||||
(bit-string-case body
|
||||
([ type code (checksum :: integer bytes 2) (rest :: binary) ] ;; TODO: check cksum
|
||||
(case type
|
||||
[(8) ;; ECHO (0 is ECHO-REPLY)
|
||||
(log-info "Ping of ~a from ~a"
|
||||
(pretty-bytes my-address)
|
||||
(pretty-bytes peer-address))
|
||||
(define reply-data0 (bit-string 0
|
||||
code
|
||||
(0 :: integer bytes 2) ;; TODO
|
||||
(rest :: binary)))
|
||||
(transition s (message (ip-packet #f
|
||||
my-address
|
||||
peer-address
|
||||
PROTOCOL-ICMP
|
||||
#""
|
||||
(ip-checksum 2 reply-data0))))]
|
||||
[else
|
||||
(log-info "ICMP ~a/~a (cksum ~a) to ~a from ~a:\n~a"
|
||||
type
|
||||
code
|
||||
checksum
|
||||
(pretty-bytes my-address)
|
||||
(pretty-bytes peer-address)
|
||||
(dump-bytes->string rest))
|
||||
#f]))
|
||||
(else #f))]
|
||||
[_ #f]))
|
||||
(void)
|
||||
(scn/union (advertisement (ip-packet ? my-address ? PROTOCOL-ICMP ? ?))
|
||||
(subscription (ip-packet ? ? my-address PROTOCOL-ICMP ? ?))
|
||||
(assertion (arp-assertion IPv4-ethertype my-address interface-name))
|
||||
(subscription (host-route my-address netmask interface-name))))))
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
;; Gateway IP route
|
||||
|
||||
(struct gateway-route-state (routes gateway-interface gateway-hwaddr) #:transparent)
|
||||
|
||||
(define (spawn-gateway-route network netmask gateway-addr interface-name)
|
||||
(define the-route (gateway-route network netmask gateway-addr interface-name))
|
||||
|
||||
(define host-route-projector (host-route (?!) (?!) ?))
|
||||
(define gateway-route-projector (gateway-route (?!) (?!) ? ?))
|
||||
(define net-route-projector (net-route (?!) (?!) ?))
|
||||
(define gateway-arp-projector (arp-query IPv4-ethertype
|
||||
gateway-addr
|
||||
(?! (ethernet-interface interface-name ?))
|
||||
(?!)))
|
||||
|
||||
(define (covered-by-some-other-route? addr routes)
|
||||
(for/or ([r (in-set routes)])
|
||||
(match-define (list net msk) r)
|
||||
(and (positive? msk)
|
||||
(ip-address-in-subnet? addr net msk))))
|
||||
|
||||
(spawn (lambda (e s)
|
||||
(match e
|
||||
[(scn g)
|
||||
(define host-ips+netmasks (trie-project/set #:take 2 g host-route-projector))
|
||||
(define gw-nets+netmasks (trie-project/set #:take 2 g gateway-route-projector))
|
||||
(define net-nets+netmasks (trie-project/set #:take 2 g net-route-projector))
|
||||
(define gw-ip+hwaddr
|
||||
(let ((vs (trie-project/set #:take 2 g gateway-arp-projector)))
|
||||
(and vs (not (set-empty? vs)) (set-first vs))))
|
||||
(when (and gw-ip+hwaddr (not (gateway-route-state-gateway-hwaddr s)))
|
||||
(log-info "Discovered gateway ~a at ~a on interface ~a."
|
||||
(ip-address->hostname gateway-addr)
|
||||
(ethernet-interface-name (car gw-ip+hwaddr))
|
||||
(pretty-bytes (cadr gw-ip+hwaddr))))
|
||||
(if (trie-empty? (project-assertions g (?! the-route)))
|
||||
(quit)
|
||||
(transition (gateway-route-state
|
||||
(set-union host-ips+netmasks
|
||||
gw-nets+netmasks
|
||||
net-nets+netmasks)
|
||||
(and gw-ip+hwaddr (car gw-ip+hwaddr))
|
||||
(and gw-ip+hwaddr (cadr gw-ip+hwaddr)))
|
||||
'()))]
|
||||
[(message (? ip-packet? p))
|
||||
(define gw-if (gateway-route-state-gateway-interface s))
|
||||
(when (not gw-if)
|
||||
(log-warning "Gateway hwaddr for ~a not known, packet dropped."
|
||||
(ip-address->hostname gateway-addr)))
|
||||
(and gw-if
|
||||
(not (equal? (ip-packet-source-interface p) (ethernet-interface-name gw-if)))
|
||||
(not (covered-by-some-other-route? (ip-packet-destination p)
|
||||
(gateway-route-state-routes s)))
|
||||
(transition s
|
||||
(message (ethernet-packet gw-if
|
||||
#f
|
||||
(ethernet-interface-hwaddr gw-if)
|
||||
(gateway-route-state-gateway-hwaddr s)
|
||||
IPv4-ethertype
|
||||
(format-ip-packet p)))))]
|
||||
[_ #f]))
|
||||
(gateway-route-state (set) #f #f)
|
||||
(scn/union (subscription the-route)
|
||||
(assertion (route-up the-route))
|
||||
(subscription (ip-packet ? ? ? ? ? ?))
|
||||
observe-local-ip-addresses-gestalt
|
||||
(subscription (net-route ? ? ?))
|
||||
(subscription (gateway-route ? ? ? ?))
|
||||
(subscription (projection->pattern gateway-arp-projector)))))
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
;; General net route
|
||||
|
||||
(define (spawn-net-route network-addr netmask link)
|
||||
(spawn-normal-ip-route (net-route network-addr netmask link) network-addr netmask link))
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
;; Normal IP route
|
||||
|
||||
(define (spawn-normal-ip-route the-route network netmask interface-name)
|
||||
(spawn (lambda (e s)
|
||||
(match e
|
||||
[(scn (? trie-empty?)) (quit)]
|
||||
[(message (ethernet-packet _ _ _ _ _ body))
|
||||
(define p (parse-ip-packet interface-name body))
|
||||
(and p (transition s (message p)))]
|
||||
[(message (? ip-packet? p))
|
||||
(define destination (ip-packet-destination p))
|
||||
(and (not (equal? (ip-packet-source-interface p) interface-name))
|
||||
(ip-address-in-subnet? destination network netmask)
|
||||
(transition
|
||||
s
|
||||
(lookup-arp destination
|
||||
(ethernet-interface interface-name ?)
|
||||
trie-empty
|
||||
(lambda (interface destination-hwaddr)
|
||||
(message (ethernet-packet interface
|
||||
#f
|
||||
(ethernet-interface-hwaddr interface)
|
||||
destination-hwaddr
|
||||
IPv4-ethertype
|
||||
(format-ip-packet p)))))))]
|
||||
[_ #f]))
|
||||
(void)
|
||||
(scn/union (subscription the-route)
|
||||
(assertion (route-up the-route))
|
||||
(subscription (ethernet-packet-pattern interface-name #t IPv4-ethertype))
|
||||
(assertion (arp-interface interface-name))
|
||||
(subscription (ip-packet ? ? ? ? ? ?)))))
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
|
||||
(define IPv4-ethertype #x0800)
|
||||
|
||||
(define IP-VERSION 4)
|
||||
(define IP-MINIMUM-HEADER-LENGTH 5)
|
||||
|
||||
(define PROTOCOL-ICMP 1)
|
||||
|
||||
(define default-ttl 64)
|
||||
|
||||
(define (parse-ip-packet interface-name body)
|
||||
;; (log-info "IP ~a got body ~a" (pretty-bytes my-address) (pretty-bytes body))
|
||||
(bit-string-case body
|
||||
([ (= IP-VERSION :: bits 4)
|
||||
(header-length :: bits 4)
|
||||
service-type
|
||||
(total-length :: bits 16)
|
||||
(id :: bits 16)
|
||||
(flags :: bits 3)
|
||||
(fragment-offset :: bits 13)
|
||||
ttl
|
||||
protocol
|
||||
(header-checksum :: bits 16) ;; TODO: check checksum
|
||||
(source-ip0 :: binary bits 32)
|
||||
(destination-ip0 :: binary bits 32)
|
||||
(rest :: binary) ]
|
||||
(let* ((source-ip (bit-string->bytes source-ip0))
|
||||
(destination-ip (bit-string->bytes destination-ip0))
|
||||
(options-length (* 4 (- header-length IP-MINIMUM-HEADER-LENGTH)))
|
||||
(data-length (- total-length (* 4 header-length))))
|
||||
(if (and (>= header-length 5)
|
||||
(>= (bit-string-byte-count body) (* header-length 4)))
|
||||
(bit-string-case rest
|
||||
([ (opts :: binary bytes options-length)
|
||||
(data :: binary bytes data-length)
|
||||
(:: binary) ] ;; Very short ethernet packets have a trailer of zeros
|
||||
(ip-packet interface-name
|
||||
(bit-string->bytes source-ip)
|
||||
(bit-string->bytes destination-ip)
|
||||
protocol
|
||||
(bit-string->bytes opts)
|
||||
(bit-string->bytes data))))
|
||||
#f)))
|
||||
(else #f)))
|
||||
|
||||
(define (format-ip-packet p)
|
||||
(match-define (ip-packet _ src dst protocol options body) p)
|
||||
|
||||
(define header-length ;; TODO: ensure options is a multiple of 4 bytes
|
||||
(+ IP-MINIMUM-HEADER-LENGTH (quotient (bit-string-byte-count options) 4)))
|
||||
|
||||
(define header0 (bit-string (IP-VERSION :: bits 4)
|
||||
(header-length :: bits 4)
|
||||
0 ;; TODO: service type
|
||||
((+ (* header-length 4) (bit-string-byte-count body))
|
||||
:: bits 16)
|
||||
(0 :: bits 16) ;; TODO: identifier
|
||||
(0 :: bits 3) ;; TODO: flags
|
||||
(0 :: bits 13) ;; TODO: fragments
|
||||
default-ttl
|
||||
protocol
|
||||
(0 :: bits 16)
|
||||
(src :: binary bits 32)
|
||||
(dst :: binary bits 32)
|
||||
(options :: binary)))
|
||||
(define full-packet (bit-string ((ip-checksum 10 header0) :: binary) (body :: binary)))
|
||||
|
||||
full-packet)
|
||||
|
||||
(define (lookup-arp ipaddr query-interface-pattern base-gestalt k)
|
||||
(on-claim #:name (string->symbol (format "lookup-arp:~a" (ip-address->hostname ipaddr)))
|
||||
(lambda (_g arp-results)
|
||||
(if (not arp-results)
|
||||
(error 'ip "Someone has published a wildcard arp result")
|
||||
(and (not (set-empty? arp-results))
|
||||
(match (set-first arp-results)
|
||||
[(list interface hwaddr)
|
||||
(log-info "ARP lookup yielded ~a on ~a for ~a"
|
||||
(pretty-bytes hwaddr)
|
||||
(ethernet-interface-name interface)
|
||||
(ip-address->hostname ipaddr))
|
||||
(when (> (set-count arp-results) 1)
|
||||
(log-warning "Ambiguous ARP result for ~a: ~v"
|
||||
(ip-address->hostname ipaddr)
|
||||
arp-results))
|
||||
(k interface hwaddr)]))))
|
||||
base-gestalt
|
||||
(arp-query IPv4-ethertype ipaddr (?! query-interface-pattern) (?!))
|
||||
#:timeout-msec 5000
|
||||
#:on-timeout (lambda ()
|
||||
(log-warning "ARP lookup of ~a failed, packet dropped"
|
||||
(ip-address->hostname ipaddr))
|
||||
'())))
|
||||
|
|
@ -0,0 +1,121 @@
|
|||
#lang syndicate/monolithic
|
||||
|
||||
(require syndicate/demand-matcher)
|
||||
(require syndicate/drivers/timer)
|
||||
(require "demo-config.rkt")
|
||||
(require "ethernet.rkt")
|
||||
(require "arp.rkt")
|
||||
(require "ip.rkt")
|
||||
(require "tcp.rkt")
|
||||
(require "udp.rkt")
|
||||
|
||||
;;(log-events-and-actions? #t)
|
||||
|
||||
(spawn-timer-driver)
|
||||
(spawn-ethernet-driver)
|
||||
(spawn-arp-driver)
|
||||
(spawn-ip-driver)
|
||||
(spawn-tcp-driver)
|
||||
(spawn-udp-driver)
|
||||
(spawn-demo-config)
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
|
||||
(let ()
|
||||
(local-require racket/set racket/string)
|
||||
|
||||
(define (spawn-session them us)
|
||||
(define user (gensym 'user))
|
||||
(define remote-detector (at-meta (?!)))
|
||||
(define peer-detector (advertise `(,(?!) says ,?)))
|
||||
(define (send-to-remote fmt . vs)
|
||||
(message (at-meta (tcp-channel us them (string->bytes/utf-8 (apply format fmt vs))))))
|
||||
(define (say who fmt . vs)
|
||||
(unless (equal? who user) (send-to-remote "~a ~a\n" who (apply format fmt vs))))
|
||||
(list (send-to-remote "Welcome, ~a.\n" user)
|
||||
(spawn
|
||||
(lambda (e peers)
|
||||
(match e
|
||||
[(message (at-meta (tcp-channel _ _ bs)))
|
||||
(transition peers (message `(,user says ,(string-trim (bytes->string/utf-8 bs)))))]
|
||||
[(message `(,who says ,what))
|
||||
(transition peers (say who "says: ~a" what))]
|
||||
[(scn assertions)
|
||||
(if (trie-empty? (trie-project assertions remote-detector))
|
||||
(quit (send-to-remote "Goodbye!\n"))
|
||||
(let ((new-peers (trie-project/set/single assertions peer-detector)))
|
||||
(define arrived (set-subtract new-peers peers))
|
||||
(define departed (set-subtract peers new-peers))
|
||||
(transition new-peers
|
||||
(list (for/list [(who arrived)] (say who "arrived."))
|
||||
(for/list [(who departed)] (say who "departed."))))))]
|
||||
[#f #f]))
|
||||
(set)
|
||||
(scn/union
|
||||
(subscription `(,? says ,?)) ;; read actual chat messages
|
||||
(subscription (advertise `(,? says ,?))) ;; observe peer presence
|
||||
(advertisement `(,user says ,?)) ;; advertise our presence
|
||||
(subscription (tcp-channel them us ?) #:meta-level 1) ;; read from remote client
|
||||
(subscription (advertise (tcp-channel them us ?)) #:meta-level 1) ;; monitor remote client
|
||||
(advertisement (tcp-channel us them ?) #:meta-level 1) ;; we will write to remote client
|
||||
))))
|
||||
|
||||
(spawn-dataspace
|
||||
(spawn-demand-matcher (advertise (tcp-channel (?!) (?! (tcp-listener 5999)) ?))
|
||||
(observe (tcp-channel (?!) (?! (tcp-listener 5999)) ?))
|
||||
#:meta-level 1
|
||||
spawn-session))
|
||||
)
|
||||
|
||||
(let ()
|
||||
(spawn (lambda (e s)
|
||||
(match e
|
||||
[(message (udp-packet src dst body))
|
||||
(log-info "Got packet from ~v: ~v" src body)
|
||||
(transition s (message
|
||||
(udp-packet dst
|
||||
src
|
||||
(string->bytes/utf-8 (format "You said: ~a" body)))))]
|
||||
[_ #f]))
|
||||
(void)
|
||||
(scn (subscription (udp-packet ? (udp-listener 6667) ?)))))
|
||||
|
||||
(let ()
|
||||
(define (spawn-session them us)
|
||||
(list
|
||||
(message 'bump)
|
||||
(spawn (lambda (e s)
|
||||
(match e
|
||||
[(message `(counter ,counter))
|
||||
(define response
|
||||
(string->bytes/utf-8
|
||||
(format (string-append
|
||||
"HTTP/1.0 200 OK\r\n\r\n"
|
||||
"<h1>Hello world from syndicate-monolithic-netstack!</h1>\n"
|
||||
"<p>This is running on syndicate-monolithic's own\n"
|
||||
"<a href='https://github.com/tonyg/syndicate/'>\n"
|
||||
"TCP/IP stack</a>.</p>\n"
|
||||
"<p>There have been ~a requests prior to this one.</p>")
|
||||
counter)))
|
||||
(quit (message (at-meta (tcp-channel us them response))))]
|
||||
[_ #f]))
|
||||
(void)
|
||||
(scn/union (subscription `(counter ,?))
|
||||
(subscription (tcp-channel them us ?) #:meta-level 1)
|
||||
(subscription (advertise (tcp-channel them us ?)) #:meta-level 1)
|
||||
(advertisement (tcp-channel us them ?) #:meta-level 1)))))
|
||||
|
||||
(spawn-dataspace
|
||||
(spawn (lambda (e counter)
|
||||
(match e
|
||||
[(message 'bump)
|
||||
(transition (+ counter 1) (message `(counter ,counter)))]
|
||||
[_ #f]))
|
||||
0
|
||||
(scn (subscription 'bump)))
|
||||
(spawn-demand-matcher (advertise (tcp-channel (?! (tcp-address ? ?)) (?! (tcp-listener 80)) ?))
|
||||
(observe (tcp-channel (?! (tcp-address ? ?)) (?! (tcp-listener 80)) ?))
|
||||
#:meta-level 1
|
||||
spawn-session))
|
||||
|
||||
)
|
||||
|
|
@ -0,0 +1,47 @@
|
|||
#lang racket/base
|
||||
|
||||
(provide on-claim)
|
||||
|
||||
(require syndicate/monolithic)
|
||||
(require syndicate/drivers/timer)
|
||||
|
||||
;; (Trie (Option (Setof (Listof Value))) ... -> (Option (Constreeof Action)))
|
||||
;; Trie Projection ...
|
||||
;; -> Action
|
||||
;; Spawns a process that observes the given projections. Any time the
|
||||
;; environment's interests change in a relevant way, calls
|
||||
;; check-and-maybe-spawn-fn with the aggregate interests and the
|
||||
;; projection results. If check-and-maybe-spawn-fn returns #f,
|
||||
;; continues to wait; otherwise, takes the action(s) returned, and
|
||||
;; quits.
|
||||
(define (on-claim #:timeout-msec [timeout-msec #f]
|
||||
#:on-timeout [timeout-handler (lambda () '())]
|
||||
#:name [name #f]
|
||||
check-and-maybe-spawn-fn
|
||||
base-interests
|
||||
. projections)
|
||||
(define timer-id (gensym 'on-claim))
|
||||
(define (on-claim-handler e state)
|
||||
(match e
|
||||
[(scn new-aggregate)
|
||||
(define projection-results
|
||||
(map (lambda (p) (trie-project/set #:take (projection-arity p) new-aggregate p))
|
||||
projections))
|
||||
(define maybe-spawn (apply check-and-maybe-spawn-fn
|
||||
new-aggregate
|
||||
projection-results))
|
||||
(if maybe-spawn
|
||||
(quit maybe-spawn)
|
||||
#f)]
|
||||
[(message (timer-expired (== timer-id) _))
|
||||
(quit (timeout-handler))]
|
||||
[_ #f]))
|
||||
(list
|
||||
(when timeout-msec (message (set-timer timer-id timeout-msec 'relative)))
|
||||
(spawn #:name name
|
||||
on-claim-handler
|
||||
(void)
|
||||
(scn/union base-interests
|
||||
(assertion-set-union*
|
||||
(map (lambda (p) (subscription (projection->pattern p))) projections))
|
||||
(subscription (timer-expired timer-id ?))))))
|
||||
|
|
@ -0,0 +1,38 @@
|
|||
#lang racket/base
|
||||
;; UDP/TCP port allocator
|
||||
|
||||
(provide spawn-port-allocator
|
||||
(struct-out port-allocation-request))
|
||||
|
||||
(require racket/set)
|
||||
(require racket/match)
|
||||
(require syndicate/monolithic)
|
||||
(require "ip.rkt")
|
||||
|
||||
(struct port-allocation-request (type k) #:prefab)
|
||||
|
||||
(struct port-allocator-state (used-ports local-ips) #:transparent)
|
||||
|
||||
(define (spawn-port-allocator allocator-type observer-gestalt compute-used-ports)
|
||||
(spawn #:name (string->symbol (format "port-allocator:~a" allocator-type))
|
||||
(lambda (e s)
|
||||
(match e
|
||||
[(scn g)
|
||||
(define local-ips (or (gestalt->local-ip-addresses g) (set)))
|
||||
(define new-used-ports (compute-used-ports g local-ips))
|
||||
(log-info "port-allocator ~v used ports: ~v" allocator-type new-used-ports)
|
||||
(transition (port-allocator-state new-used-ports local-ips) '())]
|
||||
[(message (port-allocation-request _ k))
|
||||
(define currently-used-ports (port-allocator-state-used-ports s))
|
||||
(let randomly-allocate-until-unused ()
|
||||
(define p (+ 1024 (random 64512)))
|
||||
(if (set-member? currently-used-ports p)
|
||||
(randomly-allocate-until-unused)
|
||||
(transition (struct-copy port-allocator-state s
|
||||
[used-ports (set-add currently-used-ports p)])
|
||||
(k p (port-allocator-state-local-ips s)))))]
|
||||
[_ #f]))
|
||||
(port-allocator-state (set) (set))
|
||||
(scn/union (subscription (port-allocation-request allocator-type ?))
|
||||
observe-local-ip-addresses-gestalt
|
||||
observer-gestalt)))
|
||||
|
|
@ -0,0 +1,665 @@
|
|||
#lang racket/base
|
||||
|
||||
(provide (struct-out tcp-address)
|
||||
(struct-out tcp-handle)
|
||||
(struct-out tcp-listener)
|
||||
(struct-out tcp-channel)
|
||||
spawn-tcp-driver)
|
||||
|
||||
(require racket/set)
|
||||
(require racket/match)
|
||||
(require syndicate/monolithic)
|
||||
(require syndicate/drivers/timer)
|
||||
(require syndicate/demand-matcher)
|
||||
(require bitsyntax)
|
||||
|
||||
(require "dump-bytes.rkt")
|
||||
(require "checksum.rkt")
|
||||
(require "ip.rkt")
|
||||
(require "port-allocator.rkt")
|
||||
|
||||
;; tcp-address/tcp-address : "kernel" tcp connection state machines
|
||||
;; tcp-handle/tcp-address : "user" outbound connections
|
||||
;; tcp-listener/tcp-address : "user" inbound connections
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
;; 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)
|
||||
|
||||
(struct tcp-packet (from-wire?
|
||||
source-ip
|
||||
source-port
|
||||
destination-ip
|
||||
destination-port
|
||||
sequence-number
|
||||
ack-number
|
||||
flags
|
||||
window-size
|
||||
options
|
||||
data)
|
||||
#:prefab)
|
||||
|
||||
;; (tcp-port-allocation Number (U TcpHandle TcpListener))
|
||||
(struct tcp-port-allocation (port handle) #:prefab)
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
;; User-accessible driver startup
|
||||
|
||||
(define (spawn-tcp-driver)
|
||||
(list (spawn-demand-matcher #:name 'tcp-inbound-driver
|
||||
(advertise (observe (tcp-channel ? (?! (tcp-listener ?)) ?)))
|
||||
(advertise (advertise (tcp-channel ? (?! (tcp-listener ?)) ?)))
|
||||
(lambda (server-addr)
|
||||
(match-define (tcp-listener port) server-addr)
|
||||
;; TODO: have listener shut down once user-level listener does
|
||||
(list
|
||||
(spawn #:name (string->symbol
|
||||
(format "tcp-listener-port-reservation:~a" port))
|
||||
(lambda (e s) #f)
|
||||
(void)
|
||||
(scn (assertion (tcp-port-allocation port server-addr))))
|
||||
(spawn-demand-matcher
|
||||
#:name (string->symbol (format "tcp-listener:~a" port))
|
||||
(advertise (tcp-channel (?! (tcp-address ? ?))
|
||||
(?! (tcp-address ? port))
|
||||
?))
|
||||
(observe (tcp-channel (?! (tcp-address ? ?))
|
||||
(?! (tcp-address ? port))
|
||||
?))
|
||||
(spawn-relay server-addr)))))
|
||||
(spawn-demand-matcher #:name 'tcp-outbound-driver
|
||||
(advertise (tcp-channel (?! (tcp-handle ?)) (?! (tcp-address ? ?)) ?))
|
||||
(observe (tcp-channel (?! (tcp-handle ?)) (?! (tcp-address ? ?)) ?))
|
||||
allocate-port-and-spawn-socket)
|
||||
(spawn-tcp-port-allocator)
|
||||
(spawn-kernel-tcp-driver)))
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
;; Port allocation
|
||||
|
||||
(define (spawn-tcp-port-allocator)
|
||||
(spawn-port-allocator 'tcp
|
||||
(subscription (tcp-port-allocation ? ?))
|
||||
(lambda (g local-ips)
|
||||
(project-assertions g (tcp-port-allocation (?!) ?)))))
|
||||
|
||||
(define (allocate-port-and-spawn-socket local-addr remote-addr)
|
||||
(message (port-allocation-request
|
||||
'tcp
|
||||
(lambda (port local-ips)
|
||||
;; TODO: Choose a sensible IP address for the outbound
|
||||
;; connection. We don't have enough information to do this
|
||||
;; well at the moment, so just pick some available local IP
|
||||
;; address.
|
||||
;;
|
||||
;; Interesting note: In some sense, the right answer is
|
||||
;; "?". This would give us a form of mobility, where IP
|
||||
;; addresses only route to a given bucket-of-state and ONLY
|
||||
;; the port number selects a substate therein. That's not
|
||||
;; how TCP is defined however so we can't do that.
|
||||
(define appropriate-ip (set-first local-ips))
|
||||
(define appropriate-host (ip-address->hostname appropriate-ip))
|
||||
(match-define (tcp-address remote-host remote-port) remote-addr)
|
||||
(define remote-ip (ip-string->ip-address remote-host))
|
||||
(list
|
||||
((spawn-relay local-addr) remote-addr (tcp-address appropriate-host port))
|
||||
(spawn-state-vector remote-ip remote-port appropriate-ip port))))))
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
;; Relay between kernel-level and user-level
|
||||
|
||||
(define relay-peer-wait-time-msec 5000)
|
||||
|
||||
(define ((spawn-relay local-user-addr) remote-addr local-tcp-addr)
|
||||
(define timer-name (list 'spawn-relay local-tcp-addr remote-addr))
|
||||
(define local-peer-traffic (?! (observe (tcp-channel remote-addr local-user-addr ?))))
|
||||
(define remote-peer-traffic (?! (advertise (tcp-channel remote-addr local-tcp-addr ?))))
|
||||
(list
|
||||
(message (set-timer timer-name relay-peer-wait-time-msec 'relative))
|
||||
(spawn #:name (string->symbol (format "tcp-relay:~v:~v:~v"
|
||||
local-user-addr
|
||||
remote-addr
|
||||
local-tcp-addr))
|
||||
(lambda (e state)
|
||||
(match e
|
||||
[(scn g)
|
||||
(define local-peer-absent? (trie-empty? (trie-project g local-peer-traffic)))
|
||||
(define remote-peer-absent? (trie-empty? (trie-project g remote-peer-traffic)))
|
||||
(define new-state (+ (if local-peer-absent? 0 1) (if remote-peer-absent? 0 1)))
|
||||
(if (< new-state state)
|
||||
(quit)
|
||||
(transition new-state '()))]
|
||||
[(message (tcp-channel (== local-user-addr) (== remote-addr) bs))
|
||||
(transition state (message (tcp-channel local-tcp-addr remote-addr bs)))]
|
||||
[(message (tcp-channel (== remote-addr) (== local-tcp-addr) bs))
|
||||
(transition state (message (tcp-channel remote-addr local-user-addr bs)))]
|
||||
[(message (timer-expired _ _))
|
||||
#:when (< state 2) ;; we only care if we're not fully connected
|
||||
(error 'spawn-relay "TCP relay process timed out waiting for peer")]
|
||||
[_ #f]))
|
||||
0
|
||||
(scn/union (subscription (projection->pattern local-peer-traffic))
|
||||
(subscription (projection->pattern remote-peer-traffic))
|
||||
(assertion (tcp-port-allocation (tcp-address-port local-tcp-addr)
|
||||
local-user-addr))
|
||||
(subscription (tcp-channel remote-addr local-tcp-addr ?))
|
||||
(subscription (tcp-channel local-user-addr remote-addr ?))
|
||||
(advertisement (tcp-channel remote-addr local-user-addr ?))
|
||||
(advertisement (tcp-channel local-tcp-addr remote-addr ?))
|
||||
(subscription (timer-expired timer-name ?))))))
|
||||
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
;; Codec & kernel-level driver
|
||||
|
||||
(define PROTOCOL-TCP 6)
|
||||
|
||||
(struct codec-state (local-ips active-state-vectors) #:transparent)
|
||||
|
||||
(define (spawn-kernel-tcp-driver)
|
||||
|
||||
(define (state-vector-active? statevec s)
|
||||
(set-member? (codec-state-active-state-vectors s) statevec))
|
||||
|
||||
(define (analyze-incoming-packet src-ip dst-ip body s)
|
||||
(bit-string-case body
|
||||
([ (src-port :: integer bytes 2)
|
||||
(dst-port :: integer bytes 2)
|
||||
(sequence-number :: integer bytes 4)
|
||||
(ack-number :: integer bytes 4)
|
||||
(data-offset :: integer bits 4)
|
||||
(reserved :: integer bits 3)
|
||||
(ns :: integer bits 1)
|
||||
(cwr :: integer bits 1)
|
||||
(ece :: integer bits 1)
|
||||
(urg :: integer bits 1)
|
||||
(ack :: integer bits 1)
|
||||
(psh :: integer bits 1)
|
||||
(rst :: integer bits 1)
|
||||
(syn :: integer bits 1)
|
||||
(fin :: integer bits 1)
|
||||
(window-size :: integer bytes 2)
|
||||
(checksum :: integer bytes 2) ;; TODO: check checksum
|
||||
(urgent-pointer :: integer bytes 2)
|
||||
(rest :: binary) ]
|
||||
(let* ((flags (set))
|
||||
(statevec (list src-ip src-port dst-ip dst-port))
|
||||
(old-active-state-vectors (codec-state-active-state-vectors s))
|
||||
(spawn-needed? (and (not (state-vector-active? statevec s))
|
||||
(zero? rst)))) ;; don't bother spawning if it's a rst
|
||||
(define-syntax-rule (set-flags! v ...)
|
||||
(begin (unless (zero? v) (set! flags (set-add flags 'v))) ...))
|
||||
(set-flags! ns cwr ece urg ack psh rst syn fin)
|
||||
(log-info "TCP ~a:~a -> ~a:~a (seq ~a, ack ~a, flags ~a, window ~a)"
|
||||
(ip-address->hostname src-ip)
|
||||
src-port
|
||||
(ip-address->hostname dst-ip)
|
||||
dst-port
|
||||
sequence-number
|
||||
ack-number
|
||||
flags
|
||||
window-size)
|
||||
(when spawn-needed? (log-info " - spawn needed!"))
|
||||
(bit-string-case rest
|
||||
([ (opts :: binary bytes (- (* data-offset 4) 20))
|
||||
(data :: binary) ]
|
||||
(let ((packet (tcp-packet #t
|
||||
src-ip
|
||||
src-port
|
||||
dst-ip
|
||||
dst-port
|
||||
sequence-number
|
||||
ack-number
|
||||
flags
|
||||
window-size
|
||||
(bit-string->bytes opts)
|
||||
(bit-string->bytes data))))
|
||||
(transition (if spawn-needed?
|
||||
(struct-copy codec-state s
|
||||
[active-state-vectors
|
||||
(set-add old-active-state-vectors statevec)])
|
||||
s)
|
||||
(list
|
||||
(when spawn-needed? (spawn-state-vector src-ip src-port
|
||||
dst-ip dst-port))
|
||||
;; TODO: get packet to the new state-vector process somehow
|
||||
(message packet)))))
|
||||
(else #f))))
|
||||
(else #f)))
|
||||
|
||||
(define statevec-projection (observe (tcp-packet ? (?!) (?!) (?!) (?!) ? ? ? ? ? ?)))
|
||||
|
||||
(define (analyze-gestalt g s)
|
||||
(define local-ips (gestalt->local-ip-addresses g))
|
||||
(define statevecs (trie-project/set #:take 4 g statevec-projection))
|
||||
(log-info "gestalt yielded statevecs ~v and local-ips ~v" statevecs local-ips)
|
||||
(transition (struct-copy codec-state s
|
||||
[local-ips local-ips]
|
||||
[active-state-vectors statevecs]) '()))
|
||||
|
||||
(define (deliver-outbound-packet p s)
|
||||
(match-define (tcp-packet #f
|
||||
src-ip
|
||||
src-port
|
||||
dst-ip
|
||||
dst-port
|
||||
sequence-number
|
||||
ack-number
|
||||
flags
|
||||
window-size
|
||||
options
|
||||
data)
|
||||
p)
|
||||
(log-info "TCP ~a:~a -> ~a:~a (seq ~a, ack ~a, flags ~a, window ~a)"
|
||||
(ip-address->hostname src-ip)
|
||||
src-port
|
||||
(ip-address->hostname dst-ip)
|
||||
dst-port
|
||||
sequence-number
|
||||
ack-number
|
||||
flags
|
||||
window-size)
|
||||
(define (flag-bit sym) (if (set-member? flags sym) 1 0))
|
||||
(define payload (bit-string (src-port :: integer bytes 2)
|
||||
(dst-port :: integer bytes 2)
|
||||
(sequence-number :: integer bytes 4)
|
||||
(ack-number :: integer bytes 4)
|
||||
((+ 5 (quotient (bit-string-byte-count options) 4))
|
||||
:: integer bits 4) ;; TODO: enforce 4-byte alignment
|
||||
(0 :: integer bits 3)
|
||||
((flag-bit 'ns) :: integer bits 1)
|
||||
((flag-bit 'cwr) :: integer bits 1)
|
||||
((flag-bit 'ece) :: integer bits 1)
|
||||
((flag-bit 'urg) :: integer bits 1)
|
||||
((flag-bit 'ack) :: integer bits 1)
|
||||
((flag-bit 'psh) :: integer bits 1)
|
||||
((flag-bit 'rst) :: integer bits 1)
|
||||
((flag-bit 'syn) :: integer bits 1)
|
||||
((flag-bit 'fin) :: integer bits 1)
|
||||
(window-size :: integer bytes 2)
|
||||
(0 :: integer bytes 2) ;; checksum location
|
||||
(0 :: integer bytes 2) ;; TODO: urgent pointer
|
||||
(data :: binary)))
|
||||
(define pseudo-header (bit-string (src-ip :: binary bytes 4)
|
||||
(dst-ip :: binary bytes 4)
|
||||
0
|
||||
PROTOCOL-TCP
|
||||
((bit-string-byte-count payload) :: integer bytes 2)))
|
||||
(transition s (message (ip-packet #f src-ip dst-ip PROTOCOL-TCP #""
|
||||
(ip-checksum 16 payload #:pseudo-header pseudo-header)))))
|
||||
|
||||
(spawn #:name 'kernel-tcp-driver
|
||||
(lambda (e s)
|
||||
(match e
|
||||
[(scn g)
|
||||
(analyze-gestalt g s)]
|
||||
[(message (ip-packet source-if src dst _ _ body))
|
||||
#:when (and source-if ;; source-if == #f iff packet originates locally
|
||||
(set-member? (codec-state-local-ips s) dst))
|
||||
(analyze-incoming-packet src dst body s)]
|
||||
[(message (? tcp-packet? p))
|
||||
#:when (not (tcp-packet-from-wire? p))
|
||||
(deliver-outbound-packet p s)]
|
||||
[_ #f]))
|
||||
(codec-state (set) (set))
|
||||
(scn/union (subscription (ip-packet ? ? ? PROTOCOL-TCP ? ?))
|
||||
(subscription (tcp-packet #f ? ? ? ? ? ? ? ? ? ?))
|
||||
(subscription (observe (tcp-packet #t ? ? ? ? ? ? ? ? ? ?)))
|
||||
observe-local-ip-addresses-gestalt)))
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
;; Per-connection state vector process
|
||||
|
||||
(struct buffer (data ;; bit-string
|
||||
seqn ;; names leftmost byte in data
|
||||
window ;; counts bytes from leftmost byte in data
|
||||
finished?) ;; boolean: true after FIN
|
||||
#:transparent)
|
||||
|
||||
(struct conn-state (outbound ;; buffer
|
||||
inbound ;; buffer
|
||||
syn-acked? ;; boolean
|
||||
latest-peer-activity-time ;; from current-inexact-milliseconds
|
||||
;; ^ the most recent time we heard from our peer
|
||||
user-timeout-base-time ;; from current-inexact-milliseconds
|
||||
;; ^ when the index of the first outbound unacknowledged byte changed
|
||||
local-peer-seen? ;; boolean
|
||||
listener-listening?) ;; boolean
|
||||
#:transparent)
|
||||
|
||||
(define transmit-check-interval-msec 2000)
|
||||
(define inbound-buffer-limit 65535)
|
||||
(define maximum-segment-size 536) ;; bytes
|
||||
(define maximum-segment-lifetime-sec (* 2 60)) ;; two minutes; 2MSL is TIME-WAIT timeout
|
||||
(define user-timeout-msec (* 5 60 1000)) ;; per RFC 793, this should be per-connection, but I
|
||||
;; cheat; RFC 793 says "the present global default is five minutes", which is
|
||||
;; reasonable to be getting on with
|
||||
|
||||
(define (spawn-state-vector src-ip src-port dst-ip dst-port)
|
||||
(define src (tcp-address (ip-address->hostname src-ip) src-port))
|
||||
(define dst (tcp-address (ip-address->hostname dst-ip) dst-port))
|
||||
(define (timer-name kind) (list 'tcp-timer kind src dst))
|
||||
|
||||
(define (next-expected-seqn s)
|
||||
(define b (conn-state-inbound s))
|
||||
(define v (buffer-seqn b))
|
||||
(and v (seq+ v (bit-string-byte-count (buffer-data b)))))
|
||||
|
||||
(define (buffer-push b data)
|
||||
(struct-copy buffer b [data (bit-string-append (buffer-data b) data)]))
|
||||
|
||||
;; ConnState -> ConnState
|
||||
(define (set-inbound-seqn seqn s)
|
||||
(struct-copy conn-state s
|
||||
[inbound (struct-copy buffer (conn-state-inbound s) [seqn seqn])]))
|
||||
|
||||
;; Bitstring ConnState -> Transition
|
||||
(define (incorporate-segment data s)
|
||||
;; (log-info "GOT INBOUND STUFF TO DELIVER ~v" data)
|
||||
(transition
|
||||
(if (buffer-finished? (conn-state-inbound s))
|
||||
s
|
||||
(struct-copy conn-state s [inbound (buffer-push (conn-state-inbound s) data)]))
|
||||
'()))
|
||||
|
||||
(define (seq+ a b) (bitwise-and #xffffffff (+ a b)))
|
||||
|
||||
;; Always positive
|
||||
(define (seq- larger smaller)
|
||||
(if (< larger smaller) ;; wraparound has occurred
|
||||
(+ (- larger smaller) #x100000000)
|
||||
(- larger smaller)))
|
||||
|
||||
(define (seq> a b)
|
||||
(< (seq- a b) #x80000000))
|
||||
|
||||
(define local-peer-detector (?! (observe (tcp-channel src dst ?))))
|
||||
(define listener-detector (?! (observe (advertise (tcp-channel ? (tcp-listener dst-port) ?)))))
|
||||
|
||||
;; ConnState -> Gestalt
|
||||
(define (compute-gestalt s)
|
||||
(define worldward-facing-gestalt
|
||||
(subscription (tcp-packet #t src-ip src-port dst-ip dst-port ? ? ? ? ? ?)))
|
||||
(define appward-facing-gestalt
|
||||
(assertion-set-union
|
||||
(subscription (projection->pattern local-peer-detector))
|
||||
(subscription (projection->pattern listener-detector))
|
||||
(subscription (tcp-channel dst src ?))
|
||||
(if (and (conn-state-syn-acked? s)
|
||||
(not (buffer-finished? (conn-state-inbound s))))
|
||||
(advertisement (tcp-channel src dst ?))
|
||||
trie-empty)))
|
||||
(assertion-set-union (subscription (timer-expired (timer-name ?) ?))
|
||||
worldward-facing-gestalt
|
||||
appward-facing-gestalt))
|
||||
|
||||
;; ConnState -> Transition
|
||||
(define (deliver-inbound-locally s)
|
||||
(define b (conn-state-inbound s))
|
||||
(if (bit-string-empty? (buffer-data b))
|
||||
(transition s '())
|
||||
(let ((chunk (bit-string->bytes (buffer-data b))))
|
||||
(transition (struct-copy conn-state s
|
||||
[inbound (struct-copy buffer b
|
||||
[data #""]
|
||||
[seqn (seq+ (buffer-seqn b) (bytes-length chunk))])])
|
||||
(message (tcp-channel src dst chunk))))))
|
||||
|
||||
;; (Setof Symbol) -> ConnState -> Transition
|
||||
(define ((check-fin flags) s)
|
||||
(define b (conn-state-inbound s))
|
||||
(unless (bit-string-empty? (buffer-data b)) ;; assured by deliver-inbound-locally
|
||||
(error 'check-fin "Nonempty inbound buffer"))
|
||||
(if (set-member? flags 'fin)
|
||||
(let ((new-s (struct-copy conn-state s
|
||||
[inbound (struct-copy buffer b
|
||||
[seqn (seq+ (buffer-seqn b) 1)] ;; reliable: count fin as a byte
|
||||
[finished? #t])])))
|
||||
(log-info "Closing inbound stream.")
|
||||
(transition new-s (scn (compute-gestalt new-s))))
|
||||
(transition s '())))
|
||||
|
||||
;; Boolean SeqNum -> ConnState -> Transition
|
||||
(define ((discard-acknowledged-outbound ack? ackn) s)
|
||||
(if (not ack?)
|
||||
(transition s '())
|
||||
(let* ((b (conn-state-outbound s))
|
||||
(base (buffer-seqn b))
|
||||
(limit (seq+ (buffer-seqn b) (bit-string-byte-count (buffer-data b))))
|
||||
(ackn (if (seq> ackn limit) limit ackn))
|
||||
(ackn (if (seq> base ackn) base ackn))
|
||||
(dist (seq- ackn base)))
|
||||
(define remaining-data (bit-string-drop (buffer-data b) (* dist 8))) ;; bit offset!
|
||||
(define new-s (struct-copy conn-state s
|
||||
[user-timeout-base-time (current-inexact-milliseconds)]
|
||||
[outbound (struct-copy buffer b [data remaining-data] [seqn ackn])]
|
||||
[syn-acked? (or (conn-state-syn-acked? s)
|
||||
(positive? dist))]))
|
||||
(transition new-s
|
||||
(when (and (not (conn-state-syn-acked? s)) (positive? dist))
|
||||
(scn (compute-gestalt new-s)))))))
|
||||
|
||||
;; Nat -> ConnState -> Transition
|
||||
(define ((update-outbound-window peer-window) s)
|
||||
(transition (struct-copy conn-state s
|
||||
[outbound (struct-copy buffer (conn-state-outbound s)
|
||||
[window peer-window])])
|
||||
'()))
|
||||
|
||||
;; ConnState -> Boolean
|
||||
(define (all-output-acknowledged? s)
|
||||
(bit-string-empty? (buffer-data (conn-state-outbound s))))
|
||||
|
||||
;; (Option SeqNum) -> ConnState -> Transition
|
||||
(define ((send-outbound old-ackn) s)
|
||||
(define b (conn-state-outbound s))
|
||||
(define pending-byte-count (max 0 (- (bit-string-byte-count (buffer-data b))
|
||||
(if (buffer-finished? b) 1 0))))
|
||||
|
||||
(define segment-size (min maximum-segment-size
|
||||
(if (conn-state-syn-acked? s) (buffer-window b) 1)
|
||||
;; ^ can only send SYN until SYN is acked
|
||||
pending-byte-count))
|
||||
(define segment-offset (if (conn-state-syn-acked? s) 0 1))
|
||||
(define chunk0 (bit-string-take (buffer-data b) (* segment-size 8))) ;; bit offset!
|
||||
(define chunk (bit-string-drop chunk0 (* segment-offset 8))) ;; bit offset!
|
||||
(define ackn (next-expected-seqn s))
|
||||
(define flags (set))
|
||||
(when ackn
|
||||
(set! flags (set-add flags 'ack)))
|
||||
(when (not (conn-state-syn-acked? s))
|
||||
(set! flags (set-add flags 'syn)))
|
||||
(when (and (buffer-finished? b)
|
||||
(conn-state-syn-acked? s)
|
||||
(= segment-size pending-byte-count)
|
||||
(not (all-output-acknowledged? s))) ;; TODO: reexamine. This looks fishy
|
||||
(set! flags (set-add flags 'fin)))
|
||||
(define window (min 65535 ;; limit of field width
|
||||
(max 0 ;; can't be negative
|
||||
(- (buffer-window (conn-state-inbound s))
|
||||
(bit-string-byte-count
|
||||
(buffer-data (conn-state-inbound s)))))))
|
||||
(transition s
|
||||
(unless (and (equal? ackn old-ackn)
|
||||
(conn-state-syn-acked? s)
|
||||
(not (set-member? flags 'fin))
|
||||
(zero? (bit-string-byte-count chunk)))
|
||||
(local-require racket/pretty)
|
||||
(pretty-write `(send-outbound (old-ackn ,old-ackn)
|
||||
(s ,s)
|
||||
(flags ,flags)))
|
||||
(flush-output)
|
||||
(message (tcp-packet #f dst-ip dst-port src-ip src-port
|
||||
(buffer-seqn b)
|
||||
(or ackn 0)
|
||||
flags
|
||||
window
|
||||
#""
|
||||
chunk)))))
|
||||
|
||||
;; ConnState -> Transition
|
||||
(define (bump-peer-activity-time s)
|
||||
(transition (struct-copy conn-state s
|
||||
[latest-peer-activity-time (current-inexact-milliseconds)])
|
||||
'()))
|
||||
|
||||
;; ConnState Number -> Boolean
|
||||
(define (heard-from-peer-within-msec? s msec)
|
||||
(<= (- (current-inexact-milliseconds) (conn-state-latest-peer-activity-time s)) msec))
|
||||
|
||||
;; ConnState -> Boolean
|
||||
(define (user-timeout-expired? s)
|
||||
(and (not (all-output-acknowledged? s))
|
||||
(> (- (current-inexact-milliseconds) (conn-state-user-timeout-base-time s))
|
||||
user-timeout-msec)))
|
||||
|
||||
;; ConnState -> Transition
|
||||
(define (quit-when-done s)
|
||||
(cond
|
||||
[(and (buffer-finished? (conn-state-outbound s))
|
||||
(buffer-finished? (conn-state-inbound s))
|
||||
(all-output-acknowledged? s)
|
||||
(not (heard-from-peer-within-msec? s (* 2 1000 maximum-segment-lifetime-sec))))
|
||||
;; Everything is cleanly shut down, and we just need to wait a while for unexpected
|
||||
;; packets before we release the state vector.
|
||||
(quit)]
|
||||
[(user-timeout-expired? s)
|
||||
;; We've been plaintively retransmitting for user-timeout-msec without hearing anything
|
||||
;; back; this is a crude approximation of the real condition for TCP_USER_TIMEOUT, but
|
||||
;; it will do for now? TODO
|
||||
(log-info "TCP_USER_TIMEOUT fired.")
|
||||
(quit)]
|
||||
[else #f]))
|
||||
|
||||
;; Action
|
||||
(define send-set-transmit-check-timer
|
||||
(message (set-timer (timer-name 'transmit-check)
|
||||
transmit-check-interval-msec
|
||||
'relative)))
|
||||
|
||||
;; SeqNum SeqNum ConnState -> Transition
|
||||
(define (reset seqn ackn s)
|
||||
(log-warning "Sending RST from ~a:~a to ~a:~a"
|
||||
(ip-address->hostname dst-ip)
|
||||
dst-port
|
||||
(ip-address->hostname src-ip)
|
||||
src-port)
|
||||
(quit (message (tcp-packet #f dst-ip dst-port src-ip src-port
|
||||
seqn
|
||||
ackn
|
||||
(set 'ack 'rst)
|
||||
0
|
||||
#""
|
||||
#""))))
|
||||
|
||||
;; ConnState -> Transition
|
||||
(define (close-outbound-stream s)
|
||||
(define b (conn-state-outbound s))
|
||||
(transition
|
||||
(if (buffer-finished? b)
|
||||
s
|
||||
(struct-copy conn-state s
|
||||
[outbound (struct-copy buffer (buffer-push b #"!") ;; dummy FIN byte
|
||||
[finished? #t])]))
|
||||
'()))
|
||||
|
||||
(define (state-vector-behavior e s)
|
||||
(define old-ackn (buffer-seqn (conn-state-inbound s)))
|
||||
(match e
|
||||
[(scn g)
|
||||
(log-info "State vector routing-update:\n~a" (trie->pretty-string g))
|
||||
(define local-peer-present? (trie-non-empty? (trie-project g local-peer-detector)))
|
||||
(define listening? (trie-non-empty? (trie-project 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 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 new-s)
|
||||
(send-outbound old-ackn)
|
||||
quit-when-done)]
|
||||
[else (transition new-s '())])]
|
||||
[(message (tcp-packet #t _ _ _ _ seqn ackn flags window options data))
|
||||
(define expected (next-expected-seqn s))
|
||||
(define is-syn? (set-member? flags 'syn))
|
||||
(define is-fin? (set-member? flags 'fin))
|
||||
(cond
|
||||
[(set-member? flags 'rst) (quit)]
|
||||
[(and (not expected) ;; no syn yet
|
||||
(or (not is-syn?) ;; and this isn't it
|
||||
(and (not (conn-state-listener-listening? s)) ;; or it is, but no listener...
|
||||
(not (conn-state-local-peer-seen? s))))) ;; ...and no outbound client
|
||||
(reset ackn ;; this is *our* seqn
|
||||
(seq+ seqn (+ (if is-syn? 1 0) (if is-fin? 1 0)))
|
||||
;; ^^ this is what we should acknowledge...
|
||||
s)]
|
||||
[else
|
||||
(sequence-transitions (cond
|
||||
[(not expected) ;; haven't seen syn yet, but we know this is it
|
||||
(incorporate-segment data (set-inbound-seqn (seq+ seqn 1) s))]
|
||||
[(= expected seqn)
|
||||
(incorporate-segment data s)]
|
||||
[else
|
||||
(transition s '())])
|
||||
deliver-inbound-locally
|
||||
(check-fin flags)
|
||||
(discard-acknowledged-outbound (set-member? flags 'ack) ackn)
|
||||
(update-outbound-window window)
|
||||
(send-outbound old-ackn)
|
||||
bump-peer-activity-time
|
||||
quit-when-done)])]
|
||||
[(message (tcp-channel _ _ bs))
|
||||
;; (log-info "GOT MORE STUFF TO DELIVER ~v" bs)
|
||||
(sequence-transitions (transition (struct-copy conn-state s
|
||||
[user-timeout-base-time
|
||||
;; Only move user-timeout-base-time if there wasn't
|
||||
;; already some outstanding output.
|
||||
(if (all-output-acknowledged? s)
|
||||
(current-inexact-milliseconds)
|
||||
(conn-state-user-timeout-base-time s))]
|
||||
[outbound (buffer-push (conn-state-outbound s) bs)])
|
||||
'())
|
||||
(send-outbound old-ackn)
|
||||
quit-when-done)]
|
||||
[(message (timer-expired (== (timer-name 'transmit-check)) _))
|
||||
;; TODO: I am abusing this timer for multiple tasks. Notably, this is a (crude) means of
|
||||
;; retransmitting outbound data as well as a means of checking for an expired
|
||||
;; TCP_USER_TIMEOUT. A better design would have separate timers and a more fine-grained
|
||||
;; approach.
|
||||
(sequence-transitions (transition s send-set-transmit-check-timer)
|
||||
(send-outbound old-ackn)
|
||||
quit-when-done)]
|
||||
[_ #f]))
|
||||
|
||||
;; (local-require racket/trace)
|
||||
;; (trace state-vector-behavior)
|
||||
|
||||
(define initial-outbound-seqn
|
||||
;; Yuck
|
||||
(inexact->exact (truncate (* #x100000000 (random)))))
|
||||
|
||||
;; TODO accept input from user process
|
||||
(list
|
||||
send-set-transmit-check-timer
|
||||
(let ((state0 (conn-state (buffer #"!" initial-outbound-seqn 0 #f) ;; dummy data at SYN position
|
||||
(buffer #"" #f inbound-buffer-limit #f)
|
||||
#f
|
||||
(current-inexact-milliseconds)
|
||||
(current-inexact-milliseconds)
|
||||
#f
|
||||
#f)))
|
||||
(spawn #:name
|
||||
(string->symbol (format "tcp-state-vector:~a:~a:~a:~a"
|
||||
(ip-address->hostname src-ip)
|
||||
src-port
|
||||
(ip-address->hostname dst-ip)
|
||||
dst-port))
|
||||
state-vector-behavior
|
||||
state0
|
||||
(scn (compute-gestalt state0))))))
|
||||
|
|
@ -0,0 +1,175 @@
|
|||
#lang racket/base
|
||||
|
||||
(provide (struct-out udp-remote-address)
|
||||
(struct-out udp-handle)
|
||||
(struct-out udp-listener)
|
||||
udp-address?
|
||||
udp-local-address?
|
||||
(struct-out udp-packet)
|
||||
spawn-udp-driver)
|
||||
|
||||
(require racket/set)
|
||||
(require racket/match)
|
||||
(require syndicate/monolithic)
|
||||
(require syndicate/demand-matcher)
|
||||
(require bitsyntax)
|
||||
|
||||
(require "dump-bytes.rkt")
|
||||
(require "checksum.rkt")
|
||||
(require "ip.rkt")
|
||||
(require "port-allocator.rkt")
|
||||
|
||||
;; udp-address/udp-address : "kernel" udp connection state machines
|
||||
;; udp-handle/udp-address : "user" outbound connections
|
||||
;; udp-listener/udp-address : "user" inbound connections
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
;; Protocol messages
|
||||
|
||||
(struct udp-remote-address (host port) #:prefab)
|
||||
(struct udp-handle (id) #:prefab)
|
||||
(struct udp-listener (port) #:prefab)
|
||||
|
||||
(define (udp-address? x)
|
||||
(or (udp-remote-address? x)
|
||||
(udp-local-address? x)))
|
||||
|
||||
(define (udp-local-address? x)
|
||||
(or (udp-handle? x)
|
||||
(udp-listener? x)))
|
||||
|
||||
;; USER-level protocol
|
||||
(struct udp-packet (source destination body) #:prefab)
|
||||
|
||||
;; KERNEL-level protocol
|
||||
(struct udp-datagram (source-ip source-port destination-ip destination-port body) #:prefab)
|
||||
(struct udp-port-allocation (port handle) #:prefab) ;; (udp-port-allocation Number UdpLocalAddress)
|
||||
|
||||
(define any-remote (udp-remote-address ? ?))
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
;; User-accessible driver startup
|
||||
|
||||
(define (spawn-udp-driver)
|
||||
(list
|
||||
(spawn-demand-matcher (observe (udp-packet ? (?! (udp-listener ?)) ?))
|
||||
(advertise (udp-packet ? (?! (udp-listener ?)) ?))
|
||||
(lambda (handle) (spawn-udp-relay (udp-listener-port handle) handle)))
|
||||
(spawn-demand-matcher (observe (udp-packet ? (?! (udp-handle ?)) ?))
|
||||
(advertise (udp-packet ? (?! (udp-handle ?)) ?))
|
||||
(lambda (handle)
|
||||
(message (port-allocation-request
|
||||
'udp
|
||||
(lambda (port local-ips) (spawn-udp-relay port handle))))))
|
||||
(spawn-udp-port-allocator)
|
||||
(spawn-kernel-udp-driver)))
|
||||
|
||||
(define (spawn-udp-port-allocator)
|
||||
(define udp-projector (udp-port-allocation (?!) ?))
|
||||
(spawn-port-allocator 'udp
|
||||
(subscription (projection->pattern udp-projector))
|
||||
(lambda (g local-ips)
|
||||
(project-assertions g udp-projector))))
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
;; Relaying
|
||||
|
||||
(define (spawn-udp-relay local-port local-user-addr)
|
||||
(log-info "Spawning UDP relay ~v / ~v" local-port local-user-addr)
|
||||
|
||||
(define local-peer-detector (?! (observe (udp-packet any-remote local-user-addr ?))))
|
||||
|
||||
(define (compute-gestalt local-ips)
|
||||
(for/fold [(g (assertion-set-union
|
||||
(subscription (projection->pattern local-peer-detector))
|
||||
(advertisement (udp-packet any-remote local-user-addr ?))
|
||||
observe-local-ip-addresses-gestalt
|
||||
(subscription (udp-packet local-user-addr any-remote ?))
|
||||
(assertion (udp-port-allocation local-port local-user-addr))))]
|
||||
[(ip (in-set local-ips))]
|
||||
(assertion-set-union g
|
||||
(subscription (udp-datagram ? ? ip local-port ?))
|
||||
(advertisement (udp-datagram ip local-port ? ? ?)))))
|
||||
|
||||
(spawn (lambda (e local-ips)
|
||||
(match e
|
||||
[(scn g)
|
||||
(define new-local-ips (gestalt->local-ip-addresses g))
|
||||
(if (trie-empty? (trie-project g local-peer-detector))
|
||||
(quit)
|
||||
(transition new-local-ips (scn (compute-gestalt new-local-ips))))]
|
||||
[(message (udp-packet (== local-user-addr) remote-addr bs))
|
||||
;; Choose arbitrary local IP address for outbound packet!
|
||||
;; TODO: what can be done? Must I examine the routing table?
|
||||
(match-define (udp-remote-address remote-host remote-port) remote-addr)
|
||||
(define remote-ip (ip-string->ip-address remote-host))
|
||||
(transition local-ips (message (udp-datagram (set-first local-ips)
|
||||
local-port
|
||||
remote-ip
|
||||
remote-port
|
||||
bs)))]
|
||||
[(message (udp-datagram si sp _ _ bs))
|
||||
(transition local-ips
|
||||
(message (udp-packet (udp-remote-address (ip-address->hostname si) sp)
|
||||
local-user-addr
|
||||
bs)))]
|
||||
[_ #f]))
|
||||
(set)
|
||||
(scn (compute-gestalt (set)))))
|
||||
|
||||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
||||
;; Codec & kernel-level driver
|
||||
|
||||
(define PROTOCOL-UDP 17)
|
||||
|
||||
(define (spawn-kernel-udp-driver)
|
||||
(spawn (lambda (e local-ips)
|
||||
(match e
|
||||
[(scn g)
|
||||
(transition (gestalt->local-ip-addresses g) '())]
|
||||
[(message (ip-packet source-if src-ip dst-ip _ _ body))
|
||||
#:when (and source-if (set-member? local-ips dst-ip))
|
||||
(bit-string-case body
|
||||
([ (src-port :: integer bytes 2)
|
||||
(dst-port :: integer bytes 2)
|
||||
(length :: integer bytes 2)
|
||||
(checksum :: integer bytes 2) ;; TODO: check checksum
|
||||
(data :: binary) ]
|
||||
(bit-string-case data
|
||||
([ (payload :: binary bytes (- length 8)) ;; min UDP header size is 8 bytes
|
||||
(:: binary) ]
|
||||
(transition local-ips (message (udp-datagram src-ip
|
||||
src-port
|
||||
dst-ip
|
||||
dst-port
|
||||
(bit-string->bytes payload)))))
|
||||
(else #f)))
|
||||
(else #f))]
|
||||
[(message (udp-datagram src-ip src-port dst-ip dst-port bs))
|
||||
#:when (set-member? local-ips src-ip)
|
||||
(let* ((payload (bit-string (src-port :: integer bytes 2)
|
||||
(dst-port :: integer bytes 2)
|
||||
((+ 8 (bit-string-byte-count bs))
|
||||
:: integer bytes 2)
|
||||
(0 :: integer bytes 2) ;; checksum location
|
||||
(bs :: binary)))
|
||||
(pseudo-header (bit-string (src-ip :: binary bytes 4)
|
||||
(dst-ip :: binary bytes 4)
|
||||
0
|
||||
PROTOCOL-UDP
|
||||
((bit-string-byte-count payload)
|
||||
:: integer bytes 2)))
|
||||
(checksummed-payload (ip-checksum #:pseudo-header pseudo-header
|
||||
6 payload)))
|
||||
(transition local-ips (message (ip-packet #f
|
||||
src-ip
|
||||
dst-ip
|
||||
PROTOCOL-UDP
|
||||
#""
|
||||
checksummed-payload))))]
|
||||
[_ #f]))
|
||||
(set)
|
||||
(scn/union (advertisement (ip-packet #f ? ? PROTOCOL-UDP ? ?))
|
||||
(subscription (ip-packet ? ? ? PROTOCOL-UDP ? ?))
|
||||
(subscription (udp-datagram ? ? ? ? ?))
|
||||
observe-local-ip-addresses-gestalt)))
|
||||
Loading…
Reference in New Issue