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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

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man

• htons, htonl, ntohs, ntohl : converts the unsigned short or integer argument between host byte order and network byte order
• poll : waits for one of a set of file descriptors to become ready to perform I/O
  • alternatives : select, epoll (epoll_create, epoll_ctl, epoll_wait), kqueue (kqueue, kevent)
• socket : creates an endpoint for communication and returns a file descriptor that refers to that endpoint
• listen : marks a socket as a passive socket, that is, as a socket that will be used to accept incoming connection requests using accept()
• accept : used with connection-based socket types. It extracts the first connection request on the queue of pending connections for the listening socket, creates a new connected socket, and returns a new file descriptor referring to that socket. The newly created socket is not in the listening state. The original socket is unaffected by this call
• send : (~write) used to transmit a message to another socket. May be used only when the socket is in a connected state (so that the intended recipient is known). The only difference between send() and write() is the presence of flags. With a zero flags argument, send() is equivalent to write()
• recv : (~read) used to receive messages from a socket. May be used to receive data on both connectionless and connection-oriented sockets. The only difference between recv() and read() is the presence of flags. With a zero flags argument, recv() is generally equivalent to read()
• bind : associate a socket fd to a local address. When a socket is created with socket(), it exists in a name space (address family) but has no address assigned to it. It is normally necessary to assign a local address using bind() before a socket may receive connections (see accept())
• connect : connects a socket fd to a remote address
• inet_addr : converts the Internet host address cp from IPv4 numbers-and-dots notation into binary data in network byte order. Use of this function is problematic because in case of error it returns -1, wich is a valid address (255.255.255.255). Avoid its use in favor of inet_aton(), inet_pton(), or getaddrinfo()
• setsockopt : manipulate options for a socket fd. Options may exist at multiple protocol levels; they are always present at the uppermost socket level
• getsockname : returns the current address to which a socket fd is bound
• fcntl : manipulate an open fd, by performing some actions, like duplicate it or changing its flags

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todo

• read the RFC and do some tests with telnet and NGINX

parsing config

• Your program has to take a configuration file as argument, or use a default path.
• Choose the port and host of each ’server’.
• Setup the server_names or not.
• The first server for a host:port will be the default for this host:port (that means it will answer to all the requests that don’t belong to an other server).
• Setup default error pages.
• Limit client body size.
• Setup routes with one or multiple of the following rules/configuration (routes wont be using regexp):
  • Define a list of accepted HTTP methods for the route.
  • Define a HTTP redirection.
  • Define a directory or a file from where the file should be searched (for example, if url /kapouet is rooted to /tmp/www, url /kapouet/pouic/toto/pouet is /tmp/www/pouic/toto/pouet).
  • Turn on or off directory listing.
  • Set a default file to answer if the request is a directory.
  • Execute CGI based on certain file extension (for example .php).
  • Make the route able to accept uploaded files and configure where they should be saved.

connection basic

• You can’t execve another web server.
• Your server must never block and the client can be bounced properly if necessary.
• It must be non-blocking and use only 1 poll() (or equivalent) for all the I/O operations between the client and the server (listen included).
• poll() (or equivalent) must check read and write at the same time.
• You must never do a read or a write operation without going through poll() (or equivalent).
• Checking the value of errno is strictly forbidden after a read or a write operation.
• You don’t need to use poll() (or equivalent) before reading your configuration file. Because you have to use non-blocking file descriptors, it is possible to use read/recv or write/send functions with no poll() (or equivalent), and your server wouldn’t be blocking. But it would consume more system resources. Thus, if you try to read/recv or write/send in any file descriptor without using poll() (or equivalent), your grade will be 0.
• You can use every macro and define like FD_SET, FD_CLR, FD_ISSET, FD_ZERO (understanding what and how they do it is very useful).
• A request to your server should never hang forever.
• Your server must be compatible with the web browser of your choice.

parsing request HTTP (fields, ...)

• We will consider that NGINX is HTTP 1.1 compliant and may be used to compare headers and answer behaviors.

response HTTP (fields, ...)

• Your HTTP response status codes must be accurate.
• You server must have default error pages if none are provided.
• You can’t use fork for something else than CGI (like PHP, or Python, and so forth).
• You must be able to serve a fully static website.

upload files

• Clients must be able to upload files.

CGI

• You need at least GET, POST, and DELETE methods.
• Do you wonder what a CGI is?
• Because you won’t call the CGI directly, use the full path as PATH_INFO.
• Just remember that, for chunked request, your server needs to unchunked it and the CGI will expect EOF as end of the body.
• Same things for the output of the CGI. If no content_length is returned from the CGI, EOF will mark the end of the returned data.
• Your program should call the CGI with the file requested as first argument.
• The CGI should be run in the correct directory for relative path file access.
• Your server should work with one CGI (php-CGI, Python, and so forth).

write tests

• Stress tests your server. It must stay available at all cost.
• Do not test with only one program.
• Write your tests with a more convenient language such as Python or Golang, and so forth. Even in C or C++ if you want to

persistent connexion

• Your server must be able to listen to multiple ports (see Configuration file)
• Your server should never die.

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cgi env variables

cgi env variables wikipedia variables environnements cgi cgi server variables on adobe

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")
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")
QUERY_STRING		: everything following the ? in the url sent by client (e.g. for url "http://server.org/query?var1=val2&var2=val2", it would be : "var1=val2&var2=val2")
REMOTE_ADDR			: ip address of the client
REMOTE_HOST			: host name of the client, empty if not known, or equal to REMOTE_ADDR
REMOTE_IDENT		: if known, username of the client, otherwise empty, use for logging only
REMOTE_USER			: username of client, if script is protected and the server support user authentification
REQUEST_METHOD		: method used for the request (for http, usually POST or GET)
SCRIPT_NAME			: path to the cgi, relative to the root, used for self-referencing URLs (e.g. "/cgi-bin/script.cgi")
SERVER_NAME			: name of the server, as hostname, IP address, or DNS (e.g. dns : "www.server.org")
SERVER_PORT			: the port number your server is listening on (e.g. 80)
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

REDIRECT_STATUS		: for exemple, 200

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ressources

• correction
• create an http server
• guide to network programming
• same, translated in french
• bind() vs connect()
• INADDR_ANY for bind
• hack with CGI
• http headers
• list of http headers fields
• http request ibm
• http request other
• request line uri