DZone Snippets: p2p code

Trivial P2P in newLISP

frontera000 (bob bae) — Fri, 08 Sep 2006 08:06:02 GMT

; a trivial P2P file sharing program written in newLISP for demo purpose
;
; based on ideas from http://www.freedom-to-tinker.com/tinyp2p.html
; and http://ansuz.sooke.bc.ca/software/molester/ and
; http://ansuz.sooke.bc.ca/software/molester/2005010301.php
;
; command reference
; i/ advertise presence of your node to the peer
; g/ requests a file
; f forward to peers
; h/ gets list of all peers
;
; used internally
; e/ expect a file
; x sent after receiving a file to make sure
;
; the program below is a toy, not a serious p2p program.
;
; differences from original mole-ster:
; use of 'x' -- to allow data receipt on receiving side when file is sent
; data is read in 8k chunks at a time. this is to avoid having to read
; the entire file into a buffer before writing. it allows larger files to be
; transferred.
;
; more more information refer to the original mole-ster web sites.
;





(context 'P2P)



(constant 'SIGINT 2)

(define (interrupted)

  (println "interruted by user!")

  (exit))



(signal SIGINT interrupted)



(set 'my-address "")

(set 'my-password "")

(set 'peers '())



(define (get-addr addr-and-port)  (regex "(.*):(.*)" addr-and-port)  $1)

(define (get-port addr-and-port)  (regex "(.*):(.*)" addr-and-port)  (integer $2))



(define (op-send dest-addr source-addr filename data)

  (if (set 'socket (net-connect (get-addr dest-addr) (get-port dest-addr)))

      (begin

			(net-send socket (format "%s %s %s/" my-password source-addr filename))

			(net-send socket data )

			(if (!= data "")

				(net-receive socket 'buf 1))

			(close socket))))



(define (P2P:P2P my-password peer-address my-address commands )

  (set 'peers (append peers (list peer-address)))

  (dolist (cmd commands)  (op-send peer-address my-address cmd ""))

  (set 'socket (net-listen  (get-port my-address)))

  (while true 

	 (while  (and (not (net-error)) (not (net-select socket "read" 1000)))

		 (if (net-error) (print (net-error))))

	 (set 'peer-socket (net-accept socket)) (net-receive peer-socket 'buf 1024 "/") 

	 (regex "^([a-zA-Z0-9]*) ([0-9:.]*) ([e-i])([^/]*)(/)" buf) 

	 (set 'peer-password $1) 

	 (set 'peer-address $2) 

	 (set 'peer-command $3) 

	 (set 'requested-filename $4) 

	 (set 'data $6) 

	 (if (= peer-password my-password) 

	     (case peer-command

	       ("e" (begin

	       			(set 'finished false)

	       			(while (not finished)

	       		     	(while (and (not (net-error)) (not (net-select peer-socket "read" 1000)))

	       		     		(if (net-error) (print (net-error))))

			    		(if (!= nil (net-receive peer-socket 'input-data 8192))

			    			(begin

								(append-file  requested-filename input-data)

							(set 'finished true)))

					(net-send socket "x")))

	       ("f"  (dolist (peer peers)   (op-send peer my-address requested-filename data)))

	       ("g" (op-send peer-address my-address (append "e" requested-filename) 

	       			(read-file requested-filename)))

	       ("h" (dolist (peer peers)  (op-send peer-address peer "i" "")))

	       ("i" (append peers peer-address))))

	 (close peer-socket)))



(context 'MAIN)





(P2P:P2P (main-args 2) (main-args 3) (main-args 4)  (slice (main-args) 5 -1))

uP2P — micro P2P file sharing application

413x () — Tue, 28 Mar 2006 15:45:07 GMT



#!/bin/sh

# uP2P.sh 0.0.1, 436 characters (excluding comments)

[ $3 ]&&export W=$1 H="$2 $3" K=`mktemp`;Z=/dev/null;e(){ echo "$*";};n(){

nc $* 2>$Z;};x(){ nc -lp ${H#* } -e $1 &>$Z <$Z&};f(){ cat $K|while read h;do

e $W $1 "$2"|n $h;done };case $# in 4)e $W s "$4"|n $H|while read h p f; do

e $W g "$f"|n $h $p>"$f";done;;5)e $H>$K;e $W d $H|n $4 $5>>$K;x $0;;0)x $0

read w c r;[ $W = $w ]&&case $c in s)f l "$r";;g)cat "$r";;a)e $r>>$K;;d)cat $K

f a "$r";;l)ls|grep "$r"|sed "s/^/$H /";;esac;;esac

Source: uP2P, mentioned here

six line peer-to-peer client/server in ruby

413x () — Tue, 28 Mar 2006 15:39:33 GMT

slonik AZ wrote:

> slashdot published an article on someone's

> 15 lines long Peer-2-Peer application

> http://developers.slashdot.org/article.pl?sid=04/12/15/1953227

> Another person followed up with a 9 line equivalent Perl code.

> I wonder what an equivalent Ruby program would look like?

I did this 9.5 hours ago. Compared to the python one it is not

vulnerable to File stealing attacks (a client can request a file

../foobar and ~/foobar from the python server and will get it back

AFAIK) and 6 lines long. It is however vulnerable to the DRb style

.instance_eval exploits. I will fix this shortly, but I might have to

use 7 lines then.



# Server: ruby p2p.rb password server server-uri merge-servers

# Sample: ruby p2p.rb foobar server druby://localhost:1337 druby://foo.bar:1337

# Client: ruby p2p.rb password client server-uri download-pattern

# Sample: ruby p2p.rb foobar client druby://localhost:1337 *.rb

require'drb';F,D,C,P,M,U,*O=File,Class,Dir,*ARGV;def s(p)F.split(p[/[^|].*/])[-1

]end;def c(u);DRbObject.new((),u)end;def x(u)[P,u].hash;end;M=="client"&&c(U).f(

x(U)).each{|n|p,c=x(n),c(n);(c.f(p,O[0],0).map{|f|s f}-D["*"]).each{|f|F.open(f,

"w"){|o|o<t==0&&D[s(a)]||t==1&&F.read(s(a))||p(a))end;def y()(p(U)+p).each{|u|c(u).f(x(u),

p(U))rescue()};self;end;private;def p(x=[]);O.push(*x).uniq!;O;end}.new.y;sleep)

Source: p2p.rb (Florian Gross), mentioned here