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simple WebSocket Server make use of netcat
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| HTTP/1.1 200 OK | |
| Content-Type: text/html; charset=UTF-8 | |
| Content-Length: 3714 | |
| Date: Sun, 16 Mar 2014 11:24:33 GMT | |
| Server: lighttpd/1.4.30 | |
| <?xml version="1.0" encoding="UTF-8"?> | |
| <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> | |
| <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en"> | |
| <head> | |
| <script type="text/javascript"> | |
| sock=new WebSocket("ws://lfs7:WEB_SOCKET_PORT") | |
| sock.onmessage = function (event) { | |
| document.write(event.data); | |
| } | |
| </script> | |
| </head> | |
| <body> | |
| </body> | |
| </html> |
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| #!/bin/ksh | |
| typeset port=$((RANDOM % 60000)) | |
| while ((port < 30000)); do | |
| port=$((RANDOM % 60000)) | |
| done | |
| typeset pipe=`mktemp -u` | |
| mkfifo $pipe | |
| trap "rm -f $pipe" INT | |
| cat test.html | m4 -DWEB_SOCKET_PORT=$port | nc -l localhost $((port+1)) >/dev/null & | |
| sleep 2 && firefox http://localhost:$((port+1)) & | |
| typeset data={} | |
| function Dec2Hex { | |
| typeset num=`echo 'obase=16; ibase=10; '"$1" | bc` | |
| if ((${#num} == 1)); then | |
| num=0"$num" | |
| fi | |
| printf "0x%s" $num | |
| } | |
| # see RFC6455 "Base Framing Protocol" | |
| function send_encoded_frame { | |
| typeset data="$1" | |
| # 1st nible: 0x8 -> the final frame | |
| # 2nd bible: 0x1 -> textual frame | |
| typeset first_byte="0x81" | |
| typeset payload_length=${#data} | |
| typeset second_byte=`Dec2Hex $payload_length` # no mask | |
| printf "%s%s" $first_byte $second_byte | xxd -r -p | |
| printf "%s" "$data" | |
| } | |
| function response { | |
| echo "${data.key}" >x | |
| outkey=`printf %s "${data.key}" | dos2unix` | |
| outkey+="258EAFA5-E914-47DA-95CA-C5AB0DC85B11" | |
| #outkey=`printf %s "$outkey" | sha1sum | cut -d ' ' -f 1 | xxd -r -p | base64` | |
| outkey=`printf %s "$outkey" | openssl dgst -binary -sha1 | openssl base64` | |
| printf "HTTP/1.1 101 Switching Protocols\r\n" | |
| printf "Upgrade: websocket\r\n" | |
| printf "Connection: Upgrade\r\n" | |
| printf "Sec-WebSocket-Accept: %s\r\n" "$outkey" | |
| printf "\r\n" | |
| # data frame | |
| send_encoded_frame "From WebSocket: hello world" | |
| } | |
| function get_arg { | |
| echo "$1" | cut -d' ' -f 2 | |
| } | |
| function handshake { | |
| typeset line="$1" | |
| if printf %s "$line" | grep -q $'^\r$'; then | |
| echo "handshake completed" >&2 | |
| response | |
| else | |
| case "$line" in | |
| User-Agent*) | |
| data.agent=`get_arg "$line"` | |
| ;; | |
| Sec-WebSocket-Key*) | |
| data.key=`get_arg "$line"` | |
| ;; | |
| Origin*) | |
| data.origin=`get_arg "$line"` | |
| ;; | |
| esac | |
| fi | |
| } | |
| function server { | |
| echo "server listening on $port" >&2 | |
| typeset line | |
| cat $pipe | nc -l localhost "$port" | while read line; do | |
| handshake "$line" | |
| done | |
| } | |
| function loopback { | |
| cat - > $pipe | |
| } | |
| server | loopback |
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