Xebra Module Communication Protocol
Basic Communication
For every string message that is to be sent between a module and server, the sender first sends the length of the message ENCODED_MESSAGE_LENGTH and then the message MESSAGE. The max length FRAG_SIZE of a message to be sent is 65536 bytes. If a message is longer, it is divided into fragments. ENCODED_MESSAGE_LENGTH is called ENCODED_ because it also contains a FRAG_FLAG which specifies if the next message is a fragment and has to be assembled to a whole message after receiving.
Let's say the server wants so send a message of size 150'000 bytes to the module. The following would be sent: [65536 FRAG_FLAG=1][Message part 1...][65536 FRAG_FLAG=1][Message part 2....][18928 FRAG_FLAG=0][Message part 3....]
The ENCODED_MESSAGE_LENGTH is constructed as follows: The lenght of the message (integer) is shifted by 1 bit to the left. Then the most right bit is set to FRAG_FLAG.
Request Message
For every request, the module sends a message of the following format to the server:
REQUEST = GET_REQUEST | POST_TABLE_REQUEST | POST_PLAIN_REQUEST; GET_REQUEST = KEY_GET BODY TABLE_ARGS; POST_TABLE_REQUEST = KEY_POST HEADER HEADERS_IN_WITH_CT HEADERS_OUT SUBPROCESS_ENVIRONMENT_VARS TABLE_ARGS; POST_PLAIN_REQUEST = KEY_POST BODY PLAIN_ARGS; BODY = HEADER HEADERS_IN HEADERS_OUT SUBPROCESS_ENVIRONMENT_VARS; HEADER = KEY_SPACE url KEY_SPACE KEY_HTTP; HEADERS_IN = KEY_HI {TABLE_ENTRY} KEY_END; HEADERS_IN_WITH_CT = KEY_HI {TABLE_ENTRY} KEY_T_NAME KEY_CT KEY_T_VALUE KEY_CT_FORM {TABLE_ENTRY} KEY_END; HEADERS_OUT = KEY_HO {TABLE_ENTRY} KEY_END; SUBPROCESS_ENVIRONMENT_VARS = KEY_SE TABLE_ENTRIES KEY_END; TABLE_ENTRY = KEY_T_NAME item_name KEY_T_VALUE item_value; TABLE_ARGS = KEY_ARG {KEY_A_NAME arg_name KEY_A_VALUE arg_value} ; PLAIN_ARGS = KEY_ARG post_arg_text; KEY_GET = "GET"; KEY_POST = "POST"; KEY_HTTP = "HTTP/1.1" | "HTTP/1.0"; KEY_SPACE = " "; KEY_HI = "#HI#"; KEY_HO = "#HO#"; KEY_END = "#E#"; KEY_SE = "#SE#"; KEY_T_NAME = "#$#"; KEY_T_VALUE = "#%#"; KEY_ARG = "#A#"; KEY_A_NAME = "&"; KEY_A_VALUE = "="; KEY_CT = "Content-Type"; KEY_CT_FORM = "application/x-www-form-urlencoded";
Example
GET request with arguments
GET /test.xeb?name=admin&password=plain_text&login=true HTTP/1.1#HI##$#Host#%#localhost:55000#$#User-Agent#%#Mozilla/5.0 (X11; U; Linux x86_64; en; rv:1.9.0.11) Gecko/20080528 Epiphany/2.22 Firefox/3.0#$#Accept#%#text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8#$#Accept-Language#%#en-us,en;q=0.5#$#Accept-Encoding#%#gzip,deflate#$#Accept-Charset#%#ISO-8859-1,utf-8;q=0.7,*;q=0.7#$#Keep-Alive#%#300#$#Connection#%#keep-alive#E##HO##E##SE##E##A#&name=admin&password=plain_text&login=true#E#
POST request with form arguments
POST /test.xeb HTTP/1.1#HI##$#Host#%#10.0.10.117:55000#$#Connection#%#keep-alive#$#User-Agent#%#Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US) AppleWebKit/530.5 (KHTML, like Gecko) Chrome/2.0.172.33 Safari/530.5#$#Content-Length#%#48#$#Cache-Control#%#max-age=0#$#Origin#%#file://#$#Content-Type#%#application/x-www-form-urlencoded#$#Accept#%#application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5#$#Accept-Encoding#%#gzip,deflate,bzip2,sdch#$#Accept-Language#%#de-DE,de;q=0.8,en-US;q=0.6,en;q=0.4#$#Accept-Charset#%#ISO-8859-1,utf-8;q=0.7,*;q=0.3#E##HO##E##SE##E##A#&name=wer&test=on&hiddenField=first&submit=Submit#E#
XML-RPC POST request
POST /xmlrpc_demo/demo.xrpc HTTP/1.0#HI##$#Host#%#localhost:55000#$#User-Agent#%#xmlrpclib.py/1.0.1 (by www.pythonware.com)#$#Content-Type#%#text/xml#$#Content-Length#%#192#E##HO##E##SE##E##A#&<?xml version='1.0'?> <methodCall> <methodName>demo.sum</methodName> <params> <param> <value><int>4</int></value> </param> <param> <value><int>5</int></value> </param> </params> </methodCall> #E#
Response Message
The server answers with a response message of the following format:
RESPONSE = {COOKIE_ORDER} CONTENT_TYPE HTML; COOKIE_ORDER = "#C#" cookie_name "=" cookie_value COOKIE_OPT ";Version=1#CE#"; COOKIE_OPT = [";" "Domain=" cookie_domain] [";" "Max-Age=" cookie_max_age] [";" "Path=" cookie_path] [";" "Secure"]; CONTENT_TYPE = "#CT#" content_type; HTML = "#H#" html_code;