#ifndef HEADER_CURL_CFILTERS_H #define HEADER_CURL_CFILTERS_H /*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) 1998 - 2022, Daniel Stenberg, , et al. * * This software is licensed as described in the file COPYING, which * you should have received as part of this distribution. The terms * are also available at https://curl.se/docs/copyright.html. * * You may opt to use, copy, modify, merge, publish, distribute and/or sell * copies of the Software, and permit persons to whom the Software is * furnished to do so, under the terms of the COPYING file. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * * SPDX-License-Identifier: curl * ***************************************************************************/ struct Curl_cfilter; struct Curl_easy; struct Curl_dns_entry; struct connectdata; /* Callback to destroy resources held by this filter instance. * Implementations MUST NOT chain calls to cf->next. */ typedef void Curl_cft_destroy_this(struct Curl_cfilter *cf, struct Curl_easy *data); /* Setup the connection for `data`, using destination `remotehost`. */ typedef CURLcode Curl_cft_setup(struct Curl_cfilter *cf, struct Curl_easy *data, const struct Curl_dns_entry *remotehost); typedef void Curl_cft_close(struct Curl_cfilter *cf, struct Curl_easy *data); typedef CURLcode Curl_cft_connect(struct Curl_cfilter *cf, struct Curl_easy *data, bool blocking, bool *done); /* Return the hostname and port the connection goes to. * This may change with the connection state of filters when tunneling * is involved. * @param cf the filter to ask * @param data the easy handle currently active * @param phost on return, points to the relevant, real hostname. * this is owned by the connection. * @param pdisplay_host on return, points to the printable hostname. * this is owned by the connection. * @param pport on return, contains the port number */ typedef void Curl_cft_get_host(struct Curl_cfilter *cf, struct Curl_easy *data, const char **phost, const char **pdisplay_host, int *pport); /* Filters may return sockets and fdset flags they are waiting for. * The passes array has room for up to MAX_SOCKSPEREASYHANDLE sockets. * @return read/write fdset for index in socks * or GETSOCK_BLANK when nothing to wait on */ typedef int Curl_cft_get_select_socks(struct Curl_cfilter *cf, struct Curl_easy *data, curl_socket_t *socks); typedef bool Curl_cft_data_pending(struct Curl_cfilter *cf, const struct Curl_easy *data); typedef ssize_t Curl_cft_send(struct Curl_cfilter *cf, struct Curl_easy *data, /* transfer */ const void *buf, /* data to write */ size_t len, /* amount to write */ CURLcode *err); /* error to return */ typedef ssize_t Curl_cft_recv(struct Curl_cfilter *cf, struct Curl_easy *data, /* transfer */ char *buf, /* store data here */ size_t len, /* amount to read */ CURLcode *err); /* error to return */ typedef void Curl_cft_attach_data(struct Curl_cfilter *cf, struct Curl_easy *data); typedef void Curl_cft_detach_data(struct Curl_cfilter *cf, struct Curl_easy *data); /** * The easy handle `data` is being detached (no longer served) * by connection `conn`. All filters are informed to release any resources * related to `data`. * Note: there may be several `data` attached to a connection at the same * time. */ void Curl_conn_detach(struct connectdata *conn, struct Curl_easy *data); #define CF_TYPE_IP_CONNECT (1 << 0) #define CF_TYPE_SSL (1 << 1) /* A connection filter type, e.g. specific implementation. */ struct Curl_cftype { const char *name; /* name of the filter type */ long flags; /* flags of filter type */ Curl_cft_destroy_this *destroy; /* destroy resources of this cf */ Curl_cft_setup *setup; /* setup for a connection */ Curl_cft_connect *connect; /* establish connection */ Curl_cft_close *close; /* close conn */ Curl_cft_get_host *get_host; /* host filter talks to */ Curl_cft_get_select_socks *get_select_socks;/* sockets to select on */ Curl_cft_data_pending *has_data_pending;/* conn has data pending */ Curl_cft_send *do_send; /* send data */ Curl_cft_recv *do_recv; /* receive data */ Curl_cft_attach_data *attach_data; /* data is being handled here */ Curl_cft_detach_data *detach_data; /* data is no longer handled here */ }; /* A connection filter instance, e.g. registered at a connection */ struct Curl_cfilter { const struct Curl_cftype *cft; /* the type providing implementation */ struct Curl_cfilter *next; /* next filter in chain */ void *ctx; /* filter type specific settings */ struct connectdata *conn; /* the connection this filter belongs to */ int sockindex; /* TODO: like to get rid off this */ BIT(connected); /* != 0 iff this filter is connected */ }; /* Default implementations for the type functions, implementing nop. */ void Curl_cf_def_destroy_this(struct Curl_cfilter *cf, struct Curl_easy *data); /* Default implementations for the type functions, implementing pass-through * the filter chain. */ CURLcode Curl_cf_def_setup(struct Curl_cfilter *cf, struct Curl_easy *data, const struct Curl_dns_entry *remotehost); void Curl_cf_def_close(struct Curl_cfilter *cf, struct Curl_easy *data); CURLcode Curl_cf_def_connect(struct Curl_cfilter *cf, struct Curl_easy *data, bool blocking, bool *done); void Curl_cf_def_get_host(struct Curl_cfilter *cf, struct Curl_easy *data, const char **phost, const char **pdisplay_host, int *pport); int Curl_cf_def_get_select_socks(struct Curl_cfilter *cf, struct Curl_easy *data, curl_socket_t *socks); bool Curl_cf_def_data_pending(struct Curl_cfilter *cf, const struct Curl_easy *data); ssize_t Curl_cf_def_send(struct Curl_cfilter *cf, struct Curl_easy *data, const void *buf, size_t len, CURLcode *err); ssize_t Curl_cf_def_recv(struct Curl_cfilter *cf, struct Curl_easy *data, char *buf, size_t len, CURLcode *err); void Curl_cf_def_attach_data(struct Curl_cfilter *cf, struct Curl_easy *data); void Curl_cf_def_detach_data(struct Curl_cfilter *cf, struct Curl_easy *data); /** * Create a new filter instance, unattached to the filter chain. * Use Curl_conn_cf_add() to add it to the chain. * @param pcf on success holds the created instance * @parm cft the filter type * @param ctx the type specific context to use */ CURLcode Curl_cf_create(struct Curl_cfilter **pcf, const struct Curl_cftype *cft, void *ctx); /** * Add a filter instance to the `sockindex` filter chain at connection * `data->conn`. The filter must not already be attached. It is inserted at * the start of the chain (top). */ void Curl_conn_cf_add(struct Curl_easy *data, struct connectdata *conn, int sockindex, struct Curl_cfilter *cf); /** * Remove and destroy all filters at chain `sockindex` on connection `conn`. */ void Curl_conn_cf_discard_all(struct Curl_easy *data, struct connectdata *conn, int sockindex); /** * Discard, e.g. remove and destroy a specific filter instance. * If the filter is attached to a connection, it will be removed before * it is destroyed. */ void Curl_conn_cf_discard(struct Curl_cfilter *cf, struct Curl_easy *data); ssize_t Curl_conn_cf_send(struct Curl_cfilter *cf, struct Curl_easy *data, const void *buf, size_t len, CURLcode *err); ssize_t Curl_conn_cf_recv(struct Curl_cfilter *cf, struct Curl_easy *data, char *buf, size_t len, CURLcode *err); #define CURL_CF_SSL_DEFAULT -1 #define CURL_CF_SSL_DISABLE 0 #define CURL_CF_SSL_ENABLE 1 /** * Setup the filter chain at `sockindex` in connection `conn`, invoking * the instance `setup(remotehost)` methods. If no filter chain is * installed yet, inspects the configuration in `data` to install a * suitable filter chain. */ CURLcode Curl_conn_setup(struct Curl_easy *data, struct connectdata *conn, int sockindex, const struct Curl_dns_entry *remotehost, int ssl_mode); /** * Bring the filter chain at `sockindex` for connection `data->conn` into * connected state. Which will set `*done` to TRUE. * This can be called on an already connected chain with no side effects. * When not `blocking`, calls may return without error and `*done != TRUE`, * while the individual filters negotiated the connection. */ CURLcode Curl_conn_connect(struct Curl_easy *data, int sockindex, bool blocking, bool *done); /** * Check if the filter chain at `sockindex` for connection `conn` is * completely connected. */ bool Curl_conn_is_connected(struct connectdata *conn, int sockindex); /** * Determine if we have reached the remote host on IP level, e.g. * have a TCP connection. This turns TRUE before a possible SSL * handshake has been started/done. */ bool Curl_conn_is_ip_connected(struct Curl_easy *data, int sockindex); /** * Determine if the connection is using SSL to the remote host * (or will be once connected). This will return FALSE, if SSL * is only used in proxying and not for the tunnel itself. */ bool Curl_conn_is_ssl(struct Curl_easy *data, int sockindex); /** * Close the filter chain at `sockindex` for connection `data->conn`. * Filters remain in place and may be connected again afterwards. */ void Curl_conn_close(struct Curl_easy *data, int sockindex); /** * Return if data is pending in some connection filter at chain * `sockindex` for connection `data->conn`. */ bool Curl_conn_data_pending(struct Curl_easy *data, int sockindex); /** * Get any select fd flags and the socket filters at chain `sockindex` * at connection `conn` might be waiting for. */ int Curl_conn_get_select_socks(struct Curl_easy *data, int sockindex, curl_socket_t *socks); /** * Receive data through the filter chain at `sockindex` for connection * `data->conn`. Copy at most `len` bytes into `buf`. Return the * actuel number of bytes copied or a negative value on error. * The error code is placed into `*code`. */ ssize_t Curl_conn_recv(struct Curl_easy *data, int sockindex, char *buf, size_t len, CURLcode *code); /** * Send `len` bytes of data from `buf` through the filter chain `sockindex` * at connection `data->conn`. Return the actual number of bytes written * or a negative value on error. * The error code is placed into `*code`. */ ssize_t Curl_conn_send(struct Curl_easy *data, int sockindex, const void *buf, size_t len, CURLcode *code); /** * The easy handle `data` is being attached (served) by connection `conn`. * All filters are informed to adapt to handling `data`. * Note: there may be several `data` attached to a connection at the same * time. */ void Curl_conn_attach_data(struct connectdata *conn, struct Curl_easy *data); /** * The easy handle `data` is being detached (no longer served) * by connection `conn`. All filters are informed to release any resources * related to `data`. * Note: there may be several `data` attached to a connection at the same * time. */ void Curl_conn_detach_data(struct connectdata *conn, struct Curl_easy *data); void Curl_conn_get_host(struct Curl_easy *data, int sockindex, const char **phost, const char **pdisplay_host, int *pport); #endif /* HEADER_CURL_CFILTERS_H */