CFloor/README.md

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# CFloor
## A minimal event-based webserver written in C
The title already says everything.
## What does "event-based" mean?
The more traditional approach is to fork for every new connection. That yields the advantage of having complete seperation of the connections as well as a much simpler program structure. A big disadvantage is that the server is more susceptible for things like Slow-Lorris attacks. Also the resource consumption is higher.
This webserver handles all connection (for a given bind) in the same thread. All sockets are set as non-blocking and asynchronous meaning that new data on a socket creates a SIGIO signal that causes the data handler to check every active connection for new data. If the HTTP header for a connection is complete the handler for the site is started in a new thread.
The consequence is a very slim memory footprint.
## Feature-Set
- The server can bind to multible addresses at once.
- It can be compiled with full SSL support (OpenSSL) on a per-bind basis.
- Virtual host ("site") support including hostname wildcards
- Basic file handling with optional indexes
- CGI/1.1 support
- Dynamic logging (+ additional access log)
- All settings can be specified via a config file.
Features yet to implement:
- Keep-Alive
- Full SSL-certificate-chain
- Dynamic mods (handlers, ...)
## Modability
I designed the webserver to be as flexible as possible. If the config module is not in use every aspect of the server can be controlled in a fine-grained manner.
New handlers can be added using the `handlerGetter_t` type.
## Config File Format
```
CONFIG := { CONFIG_ITEM SP }
CONFIG_ITEM := BIND_CONFIG | LOGGING_CONFIG
BIND_CONFIG := "bind" SP BIND_ADDR SP "{" SP { BIND_ITEM SP } "}"
BIND_ADDR := BIND_IP ":" PORT_NO
BIND_IP := "*" | IP4_ADDR | IP6_ADDR
BIND_ITEM := SSL_CONFIG | SITE_CONFIG
SSL_CONFIG := "ssl" SP "{" SP { SSL_ITEM SP } "}"
SSL_ITEM := SSL_KEY | SSL_CERT
SSL_KEY := "key" SP "=" SP FILENAME
SSL_CERT := "cert" SP "=" SP FILENAME
SITE_CONFIG := "site" SP "{" SP { SITE_ITEM SP } "}"
SITE_ITEM := SITE_HOSTNAME | SITE_ROOT | HANDLER_CONFIG
SITE_HOSTNAME := HOSTNAME_KEY SP "=" SP HOSTNAME
HOSTNAME_KEY := "hostname" | "alias"
SITE_ROOT := "root" SP "=" SP FILENAME
HANDLER_CONFIG := "handler" SP FILENAME SP "{" SP { HANDLER_ITEM SP } "}"
HANDLER_ITEM := HANDLER_TYPE | HANDLER_SETTINGS
HANDLER_TYPE := "type" SP "=" SP HANDLER_TYPE_H
HANDLER_SETTINGS := HANDLER_INDEX
LOGGING_CONFIG := "logging" SP "{" SP { LOGGING_ITEM SP } "}"
LOGGING_ITEM := LOGGING_ACCESS | LOGGING_SERVER | LOGGING_VERBOSE
LOGGING_ACCESS := "access" SP "=" SP FILENAME
LOGGING_SERVER := "server" SP "=" SP FILENAME
LOGGING_VERBOSE := "verbosity" SP "=" SP VERBOSITY
HANDLER_TYPE_H := "file" | "cgi"
HANDLER_INDEX := "index" SP "=" SP FILENAME
VERBOSITY := "debug" | "info" | "warn" | "error"
SP := SPH [ SPH ]
SPH := "\n" | "\t" | " "
IP4_ADDR ... IPv4 address
IP6_ADDR ... IPv6 address
PORT_NO ... TCP port number
FILENAME ... a filename
HOSTNAME ... fully-qualified domain name
```