/* * 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 client Client related functions * ##Client releated functions * \ingroup lwsapi * * */ ///@{ /** enum lws_client_connect_ssl_connection_flags - flags that may be used * with struct lws_client_connect_info ssl_connection member to control if * and how SSL checks apply to the client connection being created */ enum lws_client_connect_ssl_connection_flags { LCCSCF_USE_SSL = (1 << 0), LCCSCF_ALLOW_SELFSIGNED = (1 << 1), LCCSCF_SKIP_SERVER_CERT_HOSTNAME_CHECK = (1 << 2), LCCSCF_ALLOW_EXPIRED = (1 << 3), LCCSCF_PIPELINE = (1 << 16), /**< Serialize / pipeline multiple client connections * on a single connection where possible. * * HTTP/1.0: possible if Keep-Alive: yes sent by server * HTTP/1.1: always possible... uses pipelining * HTTP/2: always possible... uses parallel streams * */ }; /** struct lws_client_connect_info - parameters to connect with when using * lws_client_connect_via_info() */ struct lws_client_connect_info { struct lws_context *context; /**< lws context to create connection in */ const char *address; /**< remote address to connect to */ int port; /**< remote port to connect to */ int ssl_connection; /**< 0, or a combination of LCCSCF_ flags */ const char *path; /**< uri path */ const char *host; /**< content of host header */ const char *origin; /**< content of origin header */ const char *protocol; /**< list of ws protocols we could accept */ int ietf_version_or_minus_one; /**< deprecated: currently leave at 0 or -1 */ void *userdata; /**< if non-NULL, use this as wsi user_data instead of malloc it */ const void *client_exts; /**< UNUSED... provide in info.extensions at context creation time */ const char *method; /**< if non-NULL, do this http method instead of ws[s] upgrade. * use "GET" to be a simple http client connection. "RAW" gets * you a connected socket that lws itself will leave alone once * connected. */ struct lws *parent_wsi; /**< if another wsi is responsible for this connection, give it here. * this is used to make sure if the parent closes so do any * child connections first. */ const char *uri_replace_from; /**< if non-NULL, when this string is found in URIs in * text/html content-encoding, it's replaced with uri_replace_to */ const char *uri_replace_to; /**< see uri_replace_from */ struct lws_vhost *vhost; /**< vhost to bind to (used to determine related SSL_CTX) */ struct lws **pwsi; /**< if not NULL, store the new wsi here early in the connection * process. Although we return the new wsi, the call to create the * client connection does progress the connection somewhat and may * meet an error that will result in the connection being scrubbed and * NULL returned. While the wsi exists though, he may process a * callback like CLIENT_CONNECTION_ERROR with his wsi: this gives the * user callback a way to identify which wsi it is that faced the error * even before the new wsi is returned and even if ultimately no wsi * is returned. */ const char *iface; /**< NULL to allow routing on any interface, or interface name or IP * to bind the socket to */ const char *local_protocol_name; /**< NULL: .protocol is used both to select the local protocol handler * to bind to and as the list of remote ws protocols we could * accept. * non-NULL: this protocol name is used to bind the connection to * the local protocol handler. .protocol is used for the * list of remote ws protocols we could accept */ const char *alpn; /**< NULL: allow lws default ALPN list, from vhost if present or from * list of roles built into lws * non-NULL: require one from provided comma-separated list of alpn * tokens */ /* Add new things just above here ---^ * This is part of the ABI, don't needlessly break compatibility * * The below is to ensure later library versions with new * members added above will see 0 (default) even if the app * was not built against the newer headers. */ void *_unused[4]; /**< dummy */ }; /** * lws_client_connect_via_info() - Connect to another websocket server * \param ccinfo: pointer to lws_client_connect_info struct * * This function creates a connection to a remote server using the * information provided in ccinfo. */ LWS_VISIBLE LWS_EXTERN struct lws * lws_client_connect_via_info(const struct lws_client_connect_info *ccinfo); /** * lws_init_vhost_client_ssl() - also enable client SSL on an existing vhost * * \param info: client ssl related info * \param vhost: which vhost to initialize client ssl operations on * * You only need to call this if you plan on using SSL client connections on * the vhost. For non-SSL client connections, it's not necessary to call this. * * The following members of info are used during the call * * - options must have LWS_SERVER_OPTION_DO_SSL_GLOBAL_INIT set, * otherwise the call does nothing * - provided_client_ssl_ctx must be NULL to get a generated client * ssl context, otherwise you can pass a prepared one in by setting it * - ssl_cipher_list may be NULL or set to the client valid cipher list * - ssl_ca_filepath may be NULL or client cert filepath * - ssl_cert_filepath may be NULL or client cert filepath * - ssl_private_key_filepath may be NULL or client cert private key * * You must create your vhost explicitly if you want to use this, so you have * a pointer to the vhost. Create the context first with the option flag * LWS_SERVER_OPTION_EXPLICIT_VHOSTS and then call lws_create_vhost() with * the same info struct. */ LWS_VISIBLE LWS_EXTERN int lws_init_vhost_client_ssl(const struct lws_context_creation_info *info, struct lws_vhost *vhost); /** * lws_http_client_read() - consume waiting received http client data * * \param wsi: client connection * \param buf: pointer to buffer pointer - fill with pointer to your buffer * \param len: pointer to chunk length - fill with max length of buffer * * This is called when the user code is notified client http data has arrived. * The user code may choose to delay calling it to consume the data, for example * waiting until an onward connection is writeable. * * For non-chunked connections, up to len bytes of buf are filled with the * received content. len is set to the actual amount filled before return. * * For chunked connections, the linear buffer content contains the chunking * headers and it cannot be passed in one lump. Instead, this function will * call back LWS_CALLBACK_RECEIVE_CLIENT_HTTP_READ with in pointing to the * chunk start and len set to the chunk length. There will be as many calls * as there are chunks or partial chunks in the buffer. */ LWS_VISIBLE LWS_EXTERN int lws_http_client_read(struct lws *wsi, char **buf, int *len); /** * lws_http_client_http_response() - get last HTTP response code * * \param wsi: client connection * * Returns the last server response code, eg, 200 for client http connections. * * You should capture this during the LWS_CALLBACK_ESTABLISHED_CLIENT_HTTP * callback, because after that the memory reserved for storing the related * headers is freed and this value is lost. */ LWS_VISIBLE LWS_EXTERN unsigned int lws_http_client_http_response(struct lws *wsi); LWS_VISIBLE LWS_EXTERN void lws_client_http_body_pending(struct lws *wsi, int something_left_to_send); /** * lws_client_http_body_pending() - control if client connection neeeds to send body * * \param wsi: client connection * \param something_left_to_send: nonzero if need to send more body, 0 (default) * if nothing more to send * * If you will send payload data with your HTTP client connection, eg, for POST, * when you set the related http headers in * LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER callback you should also call * this API with something_left_to_send nonzero, and call * lws_callback_on_writable(wsi); * * After sending the headers, lws will call your callback with * LWS_CALLBACK_CLIENT_HTTP_WRITEABLE reason when writable. You can send the * next part of the http body payload, calling lws_callback_on_writable(wsi); * if there is more to come, or lws_client_http_body_pending(wsi, 0); to * let lws know the last part is sent and the connection can move on. */ ///@}