/* * libwebsockets - small server side websockets and web server implementation * * Copyright (C) 2010-2018 Andy Green * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation: * version 2.1 of the License. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, * MA 02110-1301 USA * * included from libwebsockets.h */ /*! \defgroup Protocols-and-Plugins Protocols and Plugins * \ingroup lwsapi * * ##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. */ ///@{ /** struct lws_protocols - List of protocols and handlers client or server * supports. */ struct lws_protocols { const char *name; /**< Protocol name that must match the one given in the client * Javascript new WebSocket(url, 'protocol') name. */ lws_callback_function *callback; /**< The service callback used for this protocol. It allows the * service action for an entire protocol to be encapsulated in * the protocol-specific callback */ size_t per_session_data_size; /**< Each new connection using this protocol gets * this much memory allocated on connection establishment and * freed on connection takedown. A pointer to this per-connection * allocation is passed into the callback in the 'user' parameter */ size_t rx_buffer_size; /**< lws allocates this much space for rx data and informs callback * when something came. Due to rx flow control, the callback may not * be able to consume it all without having to return to the event * loop. That is supported in lws. * * If .tx_packet_size is 0, this also controls how much may be sent at * once for backwards compatibility. */ unsigned int id; /**< ignored by lws, but useful to contain user information bound * to the selected protocol. For example if this protocol was * called "myprotocol-v2", you might set id to 2, and the user * code that acts differently according to the version can do so by * switch (wsi->protocol->id), user code might use some bits as * capability flags based on selected protocol version, etc. */ void *user; /**< ignored by lws, but user code can pass a pointer here it can later access from the protocol callback */ size_t tx_packet_size; /**< 0 indicates restrict send() size to .rx_buffer_size for backwards- * compatibility. * If greater than zero, a single send() is restricted to this amount * and any remainder is buffered by lws and sent afterwards also in * these size chunks. Since that is expensive, it's preferable * to restrict one fragment you are trying to send to match this * size. */ /* Add new things just above here ---^ * This is part of the ABI, don't needlessly break compatibility */ }; /** * lws_vhost_name_to_protocol() - get vhost's protocol object from its name * * \param vh: vhost to search * \param name: protocol name * * Returns NULL or a pointer to the vhost's protocol of the requested name */ LWS_VISIBLE LWS_EXTERN const struct lws_protocols * lws_vhost_name_to_protocol(struct lws_vhost *vh, const char *name); /** * lws_get_protocol() - Returns a protocol pointer from a websocket * connection. * \param 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_VISIBLE LWS_EXTERN const struct lws_protocols * lws_get_protocol(struct lws *wsi); /** lws_protocol_get() - deprecated: use lws_get_protocol */ LWS_VISIBLE LWS_EXTERN const struct lws_protocols * lws_protocol_get(struct lws *wsi) LWS_WARN_DEPRECATED; /** * lws_protocol_vh_priv_zalloc() - Allocate and zero down a protocol's per-vhost * storage * \param vhost: vhost the instance is related to * \param prot: protocol the instance is related to * \param 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_VISIBLE LWS_EXTERN void * lws_protocol_vh_priv_zalloc(struct lws_vhost *vhost, const struct lws_protocols *prot, int size); /** * lws_protocol_vh_priv_get() - retreive a protocol's per-vhost storage * * \param vhost: vhost the instance is related to * \param 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_VISIBLE LWS_EXTERN void * lws_protocol_vh_priv_get(struct lws_vhost *vhost, const struct lws_protocols *prot); /** * lws_adjust_protocol_psds - change a vhost protocol's per session data size * * \param wsi: a connection with the protocol to change * \param new_size: the new size of the per session data size for the protocol * * Returns user_space for the wsi, after allocating * * This should not be used except to initalize a vhost protocol's per session * data size one time, before any connections are accepted. * * Sometimes the protocol wraps another protocol and needs to discover and set * its per session data size at runtime. */ LWS_VISIBLE LWS_EXTERN void * lws_adjust_protocol_psds(struct lws *wsi, size_t new_size); /** * lws_finalize_startup() - drop initial process privileges * * \param context: lws context * * This is called after the end of the vhost protocol initializations, but * you may choose to call it earlier */ LWS_VISIBLE LWS_EXTERN int lws_finalize_startup(struct lws_context *context); /** * lws_pvo_search() - helper to find a named pvo in a linked-list * * \param pvo: the first pvo in the linked-list * \param name: the name of the pvo to return if found * * Returns NULL, or a pointer to the name pvo in the linked-list */ LWS_VISIBLE LWS_EXTERN const struct lws_protocol_vhost_options * lws_pvo_search(const struct lws_protocol_vhost_options *pvo, const char *name); /** * lws_pvo_get_str() - retreive a string pvo value * * \param pvo: the first pvo in the linked-list * \param name: the name of the pvo to return if found * \param result: pointer to a const char * to get the result if any * * Returns 0 if found and *result set, or nonzero if not found */ LWS_VISIBLE LWS_EXTERN int lws_pvo_get_str(void *in, const char *name, const char **result); LWS_VISIBLE LWS_EXTERN int lws_protocol_init(struct lws_context *context); #ifdef LWS_WITH_PLUGINS /* PLUGINS implies LIBUV */ #define LWS_PLUGIN_API_MAGIC 180 /** struct lws_plugin_capability - how a plugin introduces itself to lws */ struct lws_plugin_capability { unsigned int api_magic; /**< caller fills this in, plugin fills rest */ const struct lws_protocols *protocols; /**< array of supported protocols provided by plugin */ int count_protocols; /**< how many protocols */ const struct lws_extension *extensions; /**< array of extensions provided by plugin */ int count_extensions; /**< how many extensions */ }; typedef int (*lws_plugin_init_func)(struct lws_context *, struct lws_plugin_capability *); typedef int (*lws_plugin_destroy_func)(struct lws_context *); /** struct lws_plugin */ struct lws_plugin { struct lws_plugin *list; /**< linked list */ #if (UV_VERSION_MAJOR > 0) uv_lib_t lib; /**< shared library pointer */ #else void *l; /**< so we can compile on ancient libuv */ #endif char name[64]; /**< name of the plugin */ struct lws_plugin_capability caps; /**< plugin capabilities */ }; #endif ///@}