/webserver

Primary LanguageJavaScript

TEAME MEMBERES

LABRAYJI MOHAMED FADEL, YASSIN HADARI, BRAHIM SANAOUI

Webserv

This project is about writing my ow HTTP server.

Socket

  • Create an endpoint for communication
  • Endpoint any device that connects to a computer network.

1- Create Socket :

  • int server_fd = socket(int domain, type, protocol);

  • Domain, or adresse family :

    • Communication domain in which the socket should be created
    • AF_INET : IPv4 type

  • Type : type of socket (STREAM, DATAGRAM ...)

    • We will use SOCK_STREAM that use TCP protocol

  • Protocol :

    • indicate a specific protocol to use in supporting the sockets operation (if more than one , we can specified)

  • Return is a fd;

  • The original socket that was set up for listening is used only for accepting connections ,not for exchanging data

2- Identify (name) a socket:

  • Assigning a transport address to the socket (a port number in IP networking)
  • In sockets, this operation is called binding an address and the bind system call is used for this.
  • Bind actually creates a file in the file system.
  • int bind(int socketfd, const struct sockaddr *addr, socklen_t addrlen):
    • assigns the address specified by addr to the socket referred to by the file descriptor sockfd

3- On the server, wait for incoming connection:

  • int listen(int sockfd, int backlog);

    • Make the socket like a passive socket or acceptor socket is a type of socket that is used to to accept incoming connection requests using accept
    • Backlog : defines the maximum length to which the queue of pending connections for sockfd may grow.

  • int accept(int socket, struct sockaddr *restrict address, socklen_t *restrict address_len);

    • Socket : was set for accepting connections with listen.
    • Address : gets filed in with the address of the client that is doing the connect(add, port..)
    • Grabs(attrape) the first connection request on the queue of pending connections (set up in listen) and creates a new socket for that connection.
    • Socket operations are synchronous, or blocking, and accept will block until a connection is present on the queue.

  • int select(int nfds, fd_set *restrict readfds, fd_set *restrict writefds, fd_set *restrict exceptfds, struct timeval *restrict timeout);

    • allows a program to monitor multiple file descriptors, waiting until one or more of the file descriptors become "ready" for some class of I/O operation.
    • select : to handle listen multiple socket

4- Send and recieve msgs:

  • We finally have connected sockets between a client(when you visit IP address of your server from a web browser) and a server!
  • Communication is the easy part. The same read and write system calls that work on files also work on sockets.

5- Close the socket:

  • with close(new_socket);

Select:

- select : destructive, changes our FD set

Config File Structure and Contexts (like ngnix)

  • Context : areas that these brackets define;

    • Ex: context { . . . directives }

  • Directives : server will error out on reading a configuration file with directives that are declared in the wrong context.

  • The Core contexts :

    • The Main Context : context {}
    • The Event Context : events {}
    • HTTP context : http {} // In our case default is http server

  • Server context :

    • Ex :

    http { server { # first server context } }

    • server : virtual server ,handle a specific subset of connections.
    • listen 80 0.0.0.0 : (directive) The ip address / port combination that this server block is designed to respond to
    • server_names server1 server2 :

  • The Location Context : location / { root /var/www/html; . . . } //: # (<< ---------------------------- ---------------------------------- >>)