include/libwebsockets/lws-secure-streams-client.h

/*
 * libwebsockets - small server side websockets and web server implementation
 *
 * Copyright (C) 2019 - 2020 Andy Green <andy@warmcat.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * This is the headers for secure stream api variants that deal with clients in
 * different threads or even different processes.
 *
 * lws_ss_          when client is directly using the event loop
 * lws_sstc_        when client is in a different thread to the event loop
 * lws_sspc_        when client is in a different process to the event loop
 *
 * The client api is almost the same except the slightly diffent names.
 */

/*
 * lws_sspc_ apis... different process
 */

/*
 * Helper translation so user code written to lws_ss_ can be built for
 * lws_sspc_ in one step by #define LWS_SS_USE_SSPC before including
 */

#if defined(LWS_SS_USE_SSPC)
#define lws_ss_handle lws_sspc_handle
#define lws_ss_create lws_sspc_create
#define lws_ss_destroy lws_sspc_destroy
#define lws_ss_request_tx lws_sspc_request_tx
#define lws_ss_client_connect lws_sspc_client_connect
#define lws_ss_get_sequencer lws_sspc_get_sequencer
#define lws_ss_proxy_create lws_sspc_proxy_create
#define lws_ss_get_context lws_sspc_get_context
#define lws_ss_rideshare lws_sspc_rideshare
#define lws_ss_set_metadata lws_sspc_set_metadata
#define lws_ss_add_peer_tx_credit lws_sspc_add_peer_tx_credit
#define lws_ss_get_est_peer_tx_credit lws_sspc_get_est_peer_tx_credit
#endif


struct lws_sspc_handle;

LWS_VISIBLE LWS_EXTERN int
lws_sspc_create(struct lws_context *context, int tsi, const lws_ss_info_t *ssi,
	      void *opaque_user_data, struct lws_sspc_handle **ppss,
	      struct lws_sequencer *seq_owner, const char **ppayload_fmt);

/**
 * lws_sspc_destroy() - Destroy secure stream
 *
 * \param ppss: pointer to lws_ss_t pointer to be destroyed
 *
 * Destroys the lws_ss_t pointed to by *ppss, and sets *ppss to NULL.
 */
LWS_VISIBLE LWS_EXTERN void
lws_sspc_destroy(struct lws_sspc_handle **ppss);

/**
 * lws_sspc_request_tx() - Schedule stream for tx
 *
 * \param pss: pointer to lws_ss_t representing stream that wants to transmit
 *
 * Schedules a write on the stream represented by \p pss.  When it's possible to
 * write on this stream, the *tx callback will occur with an empty buffer for
 * the stream owner to fill in.
 */
LWS_VISIBLE LWS_EXTERN void
lws_sspc_request_tx(struct lws_sspc_handle *pss);

/**
 * lws_sspc_client_connect() - Attempt the client connect
 *
 * \param h: secure streams handle
 *
 * Starts the connection process for the secure stream.  Returns 0 if OK or
 * nonzero if we have already failed.
 */
LWS_VISIBLE LWS_EXTERN int
lws_sspc_client_connect(struct lws_sspc_handle *h);

/**
 * lws_sspc_get_sequencer() - Return parent sequencer pointer if any
 *
 * \param h: secure streams handle
 *
 * Returns NULL if the secure stream is not associated with a sequencer.
 * Otherwise returns a pointer to the owning sequencer.  You can use this to
 * identify which sequencer to direct messages to, from the secure stream
 * callback.
 */
LWS_VISIBLE LWS_EXTERN struct lws_sequencer *
lws_sspc_get_sequencer(struct lws_sspc_handle *h);

/**
 * lws_sspc_proxy_create() - Start a unix domain socket proxy for Secure Streams
 *
 * \param context: lws_context
 *
 * Creates a vhost that listens on an abstract namespace unix domain socket at
 * address "proxy.ss.lws".  Client connections to this proxy to Secure Streams
 */
LWS_VISIBLE LWS_EXTERN int
lws_sspc_proxy_create(struct lws_context *context);

/**
 * lws_ss_get_context() - convenience helper to recover the lws context
 *
 * \h: secure streams handle
 *
 * Returns the lws context.  Dispenses with the need to pass a copy of it into
 * your secure streams handler.
 */

LWS_VISIBLE LWS_EXTERN struct lws_context *
lws_sspc_get_context(struct lws_sspc_handle *h);

LWS_VISIBLE LWS_EXTERN const struct lws_protocols lws_sspc_protocols[];

LWS_VISIBLE LWS_EXTERN const char *
lws_sspc_rideshare(struct lws_sspc_handle *h);


/**
 * lws_sspc_set_metadata() - allow user to bind external data to defined ss metadata
 *
 * \h: secure streams handle
 * \name: metadata name from the policy
 * \value: pointer to user-managed data to bind to name
 * \len: length of the user-managed data in value
 *
 * Binds user-managed data to the named metadata item from the ss policy.
 * If present, the metadata item is handled in a protocol-specific way using
 * the associated policy information.  For example, in the policy
 *
 *  	"\"metadata\":"		"["
 *		"{\"uptag\":"  "\"X-Upload-Tag:\"},"
 *		"{\"ctype\":"  "\"Content-Type:\"},"
 *		"{\"xctype\":" "\"X-Content-Type:\"}"
 *	"],"
 *
 * when the policy is using h1 is interpreted to add h1 headers of the given
 * name with the value of the metadata on the left.
 *
 * Return 0 if OK.
 */
LWS_VISIBLE LWS_EXTERN int
lws_sspc_set_metadata(struct lws_sspc_handle *h, const char *name,
		      void *value, size_t len);

LWS_VISIBLE LWS_EXTERN int
lws_sspc_add_peer_tx_credit(struct lws_sspc_handle *h, int32_t add);

LWS_VISIBLE LWS_EXTERN int
lws_sspc_get_est_peer_tx_credit(struct lws_sspc_handle *h);