added informations on cgi from rfc 3875

README.md

@@ -1,19 +1,4 @@
 
----
-## questions
-- mettre les fonctions specifiques a la requete, dans la class client ?
-- où est-ce que j'inclus le cgi ?
-- est-ce que le cgi est appellé par `/cgi-bin` ?
-	- non
-- g rajouté `char ** env` dans client.cpp
-	- non
-- ajouter un champ "message body" dans client ?
-	- non
-- comment organiser la creation du message reponse (cgi ou pas) et des headers ?
-- comment je gere le path `/cgi-bin/` avec la suite ?
-- qu'est-ce que le cgi renvoit comme headers ? comment c'est géré ?
-	- https://www.rfc-editor.org/rfc/rfc3875
-
 ---
 ## man
 
@@ -88,16 +73,126 @@
 - [ ] Your server must be able to listen to multiple ports (see Configuration file)
 - [ ] Your server should never die.
 
+---
+## cgi rfc
+[rfc 3875](https://www.rfc-editor.org/rfc/rfc3875)
+
+[3.1: server responsabilities](https://www.rfc-editor.org/rfc/rfc3875#section-3.1)
+
+- The server [...] receives the request from the client
+- selects a CGI script to handle the request
+- converts the client request to a CGI request
+- executes the script and converts the CGI response into a response for the client
+
+[3.3: script uri](https://www.rfc-editor.org/rfc/rfc3875#section-3.3)
+
+- the 'Script-URI' [...] MUST have the property that if the client had accessed this URI instead, then the script would have been executed
+
+[4: how the server prepare the cgi requests](https://www.rfc-editor.org/rfc/rfc3875#section-4)
+
+- the cgi receives 2 differents set of informations :
+	- the request meta-variables (in UNIX, by env variables)
+	- and the message-body
+
+[4.1: request meta-variables](https://www.rfc-editor.org/rfc/rfc3875#section-4.1)
+
+- a header field that spans multiple lines MUST be merged onto a single line
+
+[4.2: request message-body](https://www.rfc-editor.org/rfc/rfc3875#section-4.2)
+
+- unless defined otherwise, the script access request data by reading stdin
+
+[6: how the response from the script is returned to the server](https://www.rfc-editor.org/rfc/rfc3875#section-6)
+
+- The response comprises 2 parts, separated by a blank line :
+	- a message-header
+	- and a message-body
+- The message-header contains one or more header fields
+- The body may be NULL
+
+[6.2: responses types](https://www.rfc-editor.org/rfc/rfc3875#section-6.2)
+
+- four types of responses :
+	- document response
+	- local redirect response
+	- client redirect response
+	- client redirect response with document
+- document response :
+	- it must return a Content-Type header field
+	- a Status-Header field is optional (200 is assumed if omited)	
+	- the server must check the cgi-script output, and modifie it to comply with the protocol version
+- local redirect response :
+	- it must return only a Location field
+	- it contains a local path URI and query string ('local-pathquery')
+	- the server must generate the response for this local-pathquery
+- client redirect response :
+	- it must return only a Location field
+	- it contains an absolute URI path, to indicate the client that it should reprocess the request with this URI
+	- the http server must generate a 302 'Found' message
+- client redirect response with document
+	- it must return a Location field with an absolute URI path
+	- it must return the Status header field, with a value of 302 'Found'
+	- the server must check the cgi-script output, and modifie it to comply with the protocol version
+
+[6.3: cgi header fields](https://www.rfc-editor.org/rfc/rfc3875#section-6.3)
+
+- whitespace is permitted between the ":" and the field-value
+- but not between the field-name and the ":"
+- the CGI script can set three differents fields :
+	- Content-Type
+	- Location
+	- Status
+- Content-Type :
+	- if there is a body in the response, a Content-Type field must be present
+	- if there is no Content-Type, the server must not attempt to determine one
+- Location :
+	- the local URI path must be an absolut path, not a relative path, nor NULL
+	- the local URI path must, then, start with "/"
+	- the absolut URI start with "<name-of-scheme>:"
+- Status :
+	- a 3-digit integer code
+	- 4 standards :
+		- 200 'OK' indicates success, it's the default value
+		- 302 'Found' with Location header and response message-body
+		- 400 'Bad Request' an unknown request format, like missing CONTENT-TYPE
+		- 501 'Not Implemented' the script received unsupported REQUEST-METHOD
+	- construction: `Status:400 "explication of the error"\n`
+- the cgi-script can return other header fields, concerning the response message
+	- the server must translate cgi-headers syntax into http-header syntax
+	- for exemple, newline can be encoded in different ways
+- the cgi-script must not return header fields concerning client-side communication
+	- the server can remove such fields
+	- (not sure : https://www.rfc-editor.org/rfc/rfc3875#section-6.3.4)
+	- the server must resolve conflicts between script-header fields and themselves
+
+[6.3: cgi message body](https://www.rfc-editor.org/rfc/rfc3875#section-6.4)
+
+- the server must read it untill EOF
+- the server must not modify it, except to convert charset if needed
+
+[7 and 8: usefull informations about implementation and security](https://www.rfc-editor.org/rfc/rfc3875#section-7)
+
+#### questions :
+- le cgi-script doit renvoyer au moins un header suivit d'une ligne vide
+- il peut dans certains cas envoyer d'autres headers
+- le serveur doit verifier qu'il n'y a pas de doublons dans les headers
+- le serveur doit verifier le formatage des headers (typiquement l'encodage, par exemple pour les newlines)
+- ? comment on passe le body-message au script ? section 4.2
+- ? on doit gerer l'authentification ?
+- ? pourquoi on doit construire un script-cgi ? section 3.3
+- ? si l'uri correspond au script-cgi, ca appel le script donc ? section 3.3
+
 
 ---
 ## cgi env variables
-[cgi env variables](http://www.faqs.org/rfcs/rfc3875.html)
+[cgi env variables](https://www.rfc-editor.org/rfc/rfc3875#section-4.1)
 [wikipedia variables environnements cgi](https://fr.wikipedia.org/wiki/Variables_d%27environnement_CGI)
 [cgi server variables on adobe](https://helpx.adobe.com/coldfusion/cfml-reference/reserved-words-and-variables/cgi-environment-cgi-scope-variables/cgi-server-variables.html)
-```
+
+```None
 AUTH_TYPE			: if the srcipt is protected, the authentification method used to validate the user
-CONTENT_LENGTH		: length of the request content
-CONTENT_TYPE		: if there is attached information, as with method POST or PUT, this is the content type of the data (e.g. "text/plain", it is set by the attribute "enctype" in html <form> as three values : "application/x-www-form-urlencoded", "multipart/form-data", "text/plain")
+CONTENT_LENGTH		: length of the request body-message
+CONTENT_TYPE		: (Content-Type field) if there is attached information, as with method POST or PUT, this is the content type of the data (e.g. "text/plain", it is set by the attribute "enctype" in html <form> as three values : "application/x-www-form-urlencoded", "multipart/form-data", "text/plain")
 GATEWAY_INTERFACE	: CGI version (e.g. CGI/1.1)
 PATH_INFO			: if any, path of the resquest in addition to the cgi script path (e.g. for cgi script path = "/usr/web/cgi-bin/script.cgi", and the url = "http://server.org/cgi-bin/script.cgi/house", the PATH-INFO would be "house")
 PATH_TRANSLATED		: full path of the request, like path-to-cgi/PATH_INFO, null if PATH_INFO is null (e.g. for "http://server.org/cgi-bin/prog/the/path", PATH_INFO would be : "/the/path" and PATH_TRANSLATED would be : "/usr/web/cgi-bin/prog/the/path")
@@ -114,7 +209,7 @@ SERVER_PROTOCOL		: protocol used for the request (e.g. HTTP/1.1)
 SERVER_SOFTWARE		: the server software you're using (e.g. Apache 1.3)
 ```
 [redirect status for php-cgi](https://woozle.org/papers/php-cgi.html)
-```
+```None
 REDIRECT_STATUS		: for exemple, 200
 ```