libdill: Structured Concurrency for C

NAME

ws_request_key - generates an unique value for Sec-WebSocket-Key field

SYNOPSIS

#include <libdill.h>

int ws_request_key(
    char* request_key);

DESCRIPTION

WARNING: This is experimental functionality and the API may change in the future.

WebSocket is a message-based protocol defined in RFC 6455. It can be used as a bidirectional communication channel for communication with a web server.

This is a helper function that can be used when doing a custom HTTP handshake for the WebSocket protocol (see WS_NOHTTP flag). It generates an unique RFC-compliant key to be filled into Sec-WebSocket-Key of the HTTP request.

The generated key is null-terminated.

request_key: Buffer to hold the generated request key. It must be at least WS_KEY_SIZE bytes long.

This function is not available if libdill is compiled with --disable-sockets option.

RETURN VALUE

In case of success the function returns 0. In case of error it returns -1 and sets errno to one of the values below.

ERRORS

EINVAL: Invalid argument.

EXAMPLE

char request_key[WS_KEY_SIZE];
ws_request_key(request_key);
http_sendfield(s, "Sec-WebSocket-Key", request_key, -1);