Protocols and Plugins

Modules
	plugin: generic-sessions

Data Structures
struct	lws_protocols
struct	lws_plugin_capability
struct	lws_plugin

Typedefs
typedef int(*	lws_plugin_init_func) (struct lws_context *, struct lws_plugin_capability *)
typedef int(*	lws_plugin_destroy_func) (struct lws_context *)

Functions
LWS_VISIBLE LWS_EXTERN const struct lws_protocols *	lws_vhost_name_to_protocol (struct lws_vhost *vh, const char *name)
LWS_VISIBLE LWS_EXTERN const struct lws_protocols *	lws_get_protocol (struct lws *wsi)
LWS_VISIBLE LWS_EXTERN const struct lws_protocols *	lws_protocol_get (struct lws *wsi) LWS_WARN_DEPRECATED
LWS_VISIBLE LWS_EXTERN void *	lws_protocol_vh_priv_zalloc (struct lws_vhost *vhost, const struct lws_protocols *prot, int size)
LWS_VISIBLE LWS_EXTERN void *	lws_protocol_vh_priv_get (struct lws_vhost *vhost, const struct lws_protocols *prot)
LWS_VISIBLE LWS_EXTERN int	lws_finalize_startup (struct lws_context *context)

Detailed Description

Protocol and protocol plugin -related apis

Protocols bind ws protocol names to a custom callback specific to that protocol implementaion.

A list of protocols can be passed in at context creation time, but it is also legal to leave that NULL and add the protocols and their callback code using plugins.

Plugins are much preferable compared to cut and pasting code into an application each time, since they can be used standalone.

Function Documentation

lws_finalize_startup()

LWS_VISIBLE LWS_EXTERN int lws_finalize_startup

(

struct lws_context *

context

)

#include <lib/libwebsockets.h>

lws_finalize_startup() - drop initial process privileges

Parameters

context

lws context

This is called after the end of the vhost protocol initializations, but you may choose to call it earlier

lws_get_protocol()

LWS_VISIBLE LWS_EXTERN const struct lws_protocols* lws_get_protocol

(

struct lws *

wsi

)

#include <lib/libwebsockets.h>

lws_get_protocol() - Returns a protocol pointer from a websocket connection.

Parameters

wsi	pointer to struct websocket you want to know the protocol of

 Some apis can act on all live connections of a given protocol,
 this is how you can get a pointer to the active protocol if needed.

lws_protocol_get()

LWS_VISIBLE LWS_EXTERN const struct lws_protocols* lws_protocol_get

(

struct lws *

wsi

)

#include <lib/libwebsockets.h>

lws_protocol_get() - deprecated: use lws_get_protocol

lws_protocol_vh_priv_get()

LWS_VISIBLE LWS_EXTERN void* lws_protocol_vh_priv_get	(	struct lws_vhost *	vhost,
		const struct lws_protocols *	prot
	)

#include <lib/libwebsockets.h>

lws_protocol_vh_priv_get() - retreive a protocol's per-vhost storage

Parameters

vhost	vhost the instance is related to
prot	protocol the instance is related to

Recover a pointer to the allocated per-vhost storage for the protocol created by lws_protocol_vh_priv_zalloc() earlier

lws_protocol_vh_priv_zalloc()

LWS_VISIBLE LWS_EXTERN void* lws_protocol_vh_priv_zalloc	(	struct lws_vhost *	vhost,
		const struct lws_protocols *	prot,
		int	size
	)

#include <lib/libwebsockets.h>

lws_protocol_vh_priv_zalloc() - Allocate and zero down a protocol's per-vhost storage

Parameters

vhost	vhost the instance is related to
prot	protocol the instance is related to
size	bytes to allocate

Protocols often find it useful to allocate a per-vhost struct, this is a helper to be called in the per-vhost init LWS_CALLBACK_PROTOCOL_INIT

lws_vhost_name_to_protocol()

LWS_VISIBLE LWS_EXTERN const struct lws_protocols* lws_vhost_name_to_protocol	(	struct lws_vhost *	vh,
		const char *	name
	)

#include <lib/libwebsockets.h>

lws_vhost_name_to_protocol() - get vhost's protocol object from its name

Parameters

vh	vhost to search
name	protocol name

Returns NULL or a pointer to the vhost's protocol of the requested name