| #ifndef HEADER_CURL_CFILTERS_H |
| #define HEADER_CURL_CFILTERS_H |
| /*************************************************************************** |
| * _ _ ____ _ |
| * Project ___| | | | _ \| | |
| * / __| | | | |_) | | |
| * | (__| |_| | _ <| |___ |
| * \___|\___/|_| \_\_____| |
| * |
| * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, 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); |
| |
| 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); |
| |
| struct easy_pollset; |
| |
| /* Passing in an easy_pollset for monitoring of sockets, let |
| * filters add or remove sockets actions (CURL_POLL_OUT, CURL_POLL_IN). |
| * This may add a socket or, in case no actions remain, remove |
| * a socket from the set. |
| * |
| * Filter implementations need to call filters "below" *after* they have |
| * made their adjustments. This allows lower filters to override "upper" |
| * actions. If a "lower" filter is unable to write, it needs to be able |
| * to disallow POLL_OUT. |
| * |
| * A filter without own restrictions/preferences should not modify |
| * the pollset. Filters, whose filter "below" is not connected, should |
| * also do no adjustments. |
| * |
| * Examples: a TLS handshake, while ongoing, might remove POLL_IN |
| * when it needs to write, or vice versa. A HTTP/2 filter might remove |
| * POLL_OUT when a stream window is exhausted and a WINDOW_UPDATE needs |
| * to be received first and add instead POLL_IN. |
| * |
| * @param cf the filter to ask |
| * @param data the easy handle the pollset is about |
| * @param ps the pollset (inout) for the easy handle |
| */ |
| typedef void Curl_cft_adjust_pollset(struct Curl_cfilter *cf, |
| struct Curl_easy *data, |
| struct easy_pollset *ps); |
| |
| 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 bool Curl_cft_conn_is_alive(struct Curl_cfilter *cf, |
| struct Curl_easy *data, |
| bool *input_pending); |
| |
| typedef CURLcode Curl_cft_conn_keep_alive(struct Curl_cfilter *cf, |
| struct Curl_easy *data); |
| |
| /** |
| * Events/controls for connection filters, their arguments and |
| * return code handling. Filter callbacks are invoked "top down". |
| * Return code handling: |
| * "first fail" meaning that the first filter returning != CURLE_OK, will |
| * abort further event distribution and determine the result. |
| * "ignored" meaning return values are ignored and the event is distributed |
| * to all filters in the chain. Overall result is always CURLE_OK. |
| */ |
| /* data event arg1 arg2 return */ |
| #define CF_CTRL_DATA_ATTACH 1 /* 0 NULL ignored */ |
| #define CF_CTRL_DATA_DETACH 2 /* 0 NULL ignored */ |
| #define CF_CTRL_DATA_SETUP 4 /* 0 NULL first fail */ |
| #define CF_CTRL_DATA_IDLE 5 /* 0 NULL first fail */ |
| #define CF_CTRL_DATA_PAUSE 6 /* on/off NULL first fail */ |
| #define CF_CTRL_DATA_DONE 7 /* premature NULL ignored */ |
| #define CF_CTRL_DATA_DONE_SEND 8 /* 0 NULL ignored */ |
| /* update conn info at connection and data */ |
| #define CF_CTRL_CONN_INFO_UPDATE (256+0) /* 0 NULL ignored */ |
| #define CF_CTRL_FORGET_SOCKET (256+1) /* 0 NULL ignored */ |
| |
| /** |
| * Handle event/control for the filter. |
| * Implementations MUST NOT chain calls to cf->next. |
| */ |
| typedef CURLcode Curl_cft_cntrl(struct Curl_cfilter *cf, |
| struct Curl_easy *data, |
| int event, int arg1, void *arg2); |
| |
| |
| /** |
| * Queries to ask via a `Curl_cft_query *query` method on a cfilter chain. |
| * - MAX_CONCURRENT: the maximum number of parallel transfers the filter |
| * chain expects to handle at the same time. |
| * default: 1 if no filter overrides. |
| * - CONNECT_REPLY_MS: milliseconds until the first indication of a server |
| * response was received on a connect. For TCP, this |
| * reflects the time until the socket connected. On UDP |
| * this gives the time the first bytes from the server |
| * were received. |
| * -1 if not determined yet. |
| * - CF_QUERY_SOCKET: the socket used by the filter chain |
| */ |
| /* query res1 res2 */ |
| #define CF_QUERY_MAX_CONCURRENT 1 /* number - */ |
| #define CF_QUERY_CONNECT_REPLY_MS 2 /* number - */ |
| #define CF_QUERY_SOCKET 3 /* - curl_socket_t */ |
| #define CF_QUERY_TIMER_CONNECT 4 /* - struct curltime */ |
| #define CF_QUERY_TIMER_APPCONNECT 5 /* - struct curltime */ |
| #define CF_QUERY_STREAM_ERROR 6 /* error code - */ |
| |
| /** |
| * Query the cfilter for properties. Filters ignorant of a query will |
| * pass it "down" the filter chain. |
| */ |
| typedef CURLcode Curl_cft_query(struct Curl_cfilter *cf, |
| struct Curl_easy *data, |
| int query, int *pres1, void *pres2); |
| |
| /** |
| * Type flags for connection filters. A filter can have none, one or |
| * many of those. Use to evaluate state/capabilities of a filter chain. |
| * |
| * CF_TYPE_IP_CONNECT: provides an IP connection or sth equivalent, like |
| * a CONNECT tunnel, a UNIX domain socket, a QUIC |
| * connection, etc. |
| * CF_TYPE_SSL: provide SSL/TLS |
| * CF_TYPE_MULTIPLEX: provides multiplexing of easy handles |
| * CF_TYPE_PROXY provides proxying |
| */ |
| #define CF_TYPE_IP_CONNECT (1 << 0) |
| #define CF_TYPE_SSL (1 << 1) |
| #define CF_TYPE_MULTIPLEX (1 << 2) |
| #define CF_TYPE_PROXY (1 << 3) |
| |
| /* A connection filter type, e.g. specific implementation. */ |
| struct Curl_cftype { |
| const char *name; /* name of the filter type */ |
| int flags; /* flags of filter type */ |
| int log_level; /* log level for such filters */ |
| Curl_cft_destroy_this *destroy; /* destroy resources of this cf */ |
| Curl_cft_connect *do_connect; /* establish connection */ |
| Curl_cft_close *do_close; /* close conn */ |
| Curl_cft_get_host *get_host; /* host filter talks to */ |
| Curl_cft_adjust_pollset *adjust_pollset; /* adjust transfer poll set */ |
| 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_cntrl *cntrl; /* events/control */ |
| Curl_cft_conn_is_alive *is_alive; /* FALSE if conn is dead, Jim! */ |
| Curl_cft_conn_keep_alive *keep_alive; /* try to keep it alive */ |
| Curl_cft_query *query; /* query filter chain */ |
| }; |
| |
| /* 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; /* the index the filter is installed at */ |
| 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. */ |
| void Curl_cf_def_get_host(struct Curl_cfilter *cf, struct Curl_easy *data, |
| const char **phost, const char **pdisplay_host, |
| int *pport); |
| void Curl_cf_def_adjust_pollset(struct Curl_cfilter *cf, |
| struct Curl_easy *data, |
| struct easy_pollset *ps); |
| 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); |
| CURLcode Curl_cf_def_cntrl(struct Curl_cfilter *cf, |
| struct Curl_easy *data, |
| int event, int arg1, void *arg2); |
| bool Curl_cf_def_conn_is_alive(struct Curl_cfilter *cf, |
| struct Curl_easy *data, |
| bool *input_pending); |
| CURLcode Curl_cf_def_conn_keep_alive(struct Curl_cfilter *cf, |
| struct Curl_easy *data); |
| CURLcode Curl_cf_def_query(struct Curl_cfilter *cf, |
| struct Curl_easy *data, |
| int query, int *pres1, void *pres2); |
| |
| /** |
| * 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 |
| * @param 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 |
| * `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); |
| |
| /** |
| * Insert a filter (chain) after `cf_at`. |
| * `cf_new` must not already be attached. |
| */ |
| void Curl_conn_cf_insert_after(struct Curl_cfilter *cf_at, |
| struct Curl_cfilter *cf_new); |
| |
| /** |
| * Discard, e.g. remove and destroy `discard` iff |
| * it still is in the filter chain below `cf`. If `discard` |
| * is no longer found beneath `cf` return FALSE. |
| * if `destroy_always` is TRUE, will call `discard`s destroy |
| * function and free it even if not found in the subchain. |
| */ |
| bool Curl_conn_cf_discard_sub(struct Curl_cfilter *cf, |
| struct Curl_cfilter *discard, |
| struct Curl_easy *data, |
| bool destroy_always); |
| |
| /** |
| * Discard all cfilters starting with `*pcf` and clearing it afterwards. |
| */ |
| void Curl_conn_cf_discard_chain(struct Curl_cfilter **pcf, |
| struct Curl_easy *data); |
| |
| /** |
| * 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); |
| |
| |
| CURLcode Curl_conn_cf_connect(struct Curl_cfilter *cf, |
| struct Curl_easy *data, |
| bool blocking, bool *done); |
| void Curl_conn_cf_close(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); |
| CURLcode Curl_conn_cf_cntrl(struct Curl_cfilter *cf, |
| struct Curl_easy *data, |
| bool ignore_result, |
| int event, int arg1, void *arg2); |
| |
| /** |
| * Determine if the connection filter chain is using SSL to the remote host |
| * (or will be once connected). |
| */ |
| bool Curl_conn_cf_is_ssl(struct Curl_cfilter *cf); |
| |
| /** |
| * Get the socket used by the filter chain starting at `cf`. |
| * Returns CURL_SOCKET_BAD if not available. |
| */ |
| curl_socket_t Curl_conn_cf_get_socket(struct Curl_cfilter *cf, |
| struct Curl_easy *data); |
| |
| |
| #define CURL_CF_SSL_DEFAULT -1 |
| #define CURL_CF_SSL_DISABLE 0 |
| #define CURL_CF_SSL_ENABLE 1 |
| |
| /** |
| * 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 connectdata *conn, int sockindex); |
| |
| /** |
| * Connection provides multiplexing of easy handles at `socketindex`. |
| */ |
| bool Curl_conn_is_multiplex(struct connectdata *conn, 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); |
| |
| /** |
| * Return the socket used on data's connection for the index. |
| * Returns CURL_SOCKET_BAD if not available. |
| */ |
| curl_socket_t Curl_conn_get_socket(struct Curl_easy *data, int sockindex); |
| |
| /** |
| * Tell filters to forget about the socket at sockindex. |
| */ |
| void Curl_conn_forget_socket(struct Curl_easy *data, int sockindex); |
| |
| /** |
| * Adjust the pollset for the filter chain startgin at `cf`. |
| */ |
| void Curl_conn_cf_adjust_pollset(struct Curl_cfilter *cf, |
| struct Curl_easy *data, |
| struct easy_pollset *ps); |
| |
| /** |
| * Adjust pollset from filters installed at transfer's connection. |
| */ |
| void Curl_conn_adjust_pollset(struct Curl_easy *data, |
| struct easy_pollset *ps); |
| |
| /** |
| * Receive data through the filter chain at `sockindex` for connection |
| * `data->conn`. Copy at most `len` bytes into `buf`. Return the |
| * actual number of bytes copied or a negative value on error. |
| * The error code is placed into `*code`. |
| */ |
| ssize_t Curl_cf_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_cf_send(struct Curl_easy *data, int sockindex, |
| const void *buf, size_t len, CURLcode *code); |
| |
| /** |
| * The easy handle `data` is being attached to `conn`. This does |
| * not mean that data will actually do a transfer. Attachment is |
| * also used for temporary actions on the connection. |
| */ |
| void Curl_conn_ev_data_attach(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_ev_data_detach(struct connectdata *conn, |
| struct Curl_easy *data); |
| |
| /** |
| * Notify connection filters that they need to setup data for |
| * a transfer. |
| */ |
| CURLcode Curl_conn_ev_data_setup(struct Curl_easy *data); |
| |
| /** |
| * Notify connection filters that now would be a good time to |
| * perform any idle, e.g. time related, actions. |
| */ |
| CURLcode Curl_conn_ev_data_idle(struct Curl_easy *data); |
| |
| /** |
| * Notify connection filters that the transfer represented by `data` |
| * is done with sending data (e.g. has uploaded everything). |
| */ |
| void Curl_conn_ev_data_done_send(struct Curl_easy *data); |
| |
| /** |
| * Notify connection filters that the transfer represented by `data` |
| * is finished - eventually premature, e.g. before being complete. |
| */ |
| void Curl_conn_ev_data_done(struct Curl_easy *data, bool premature); |
| |
| /** |
| * Notify connection filters that the transfer of data is paused/unpaused. |
| */ |
| CURLcode Curl_conn_ev_data_pause(struct Curl_easy *data, bool do_pause); |
| |
| /** |
| * Inform connection filters to update their info in `conn`. |
| */ |
| void Curl_conn_ev_update_info(struct Curl_easy *data, |
| struct connectdata *conn); |
| |
| /** |
| * Check if FIRSTSOCKET's cfilter chain deems connection alive. |
| */ |
| bool Curl_conn_is_alive(struct Curl_easy *data, struct connectdata *conn, |
| bool *input_pending); |
| |
| /** |
| * Try to upkeep the connection filters at sockindex. |
| */ |
| CURLcode Curl_conn_keep_alive(struct Curl_easy *data, |
| struct connectdata *conn, |
| int sockindex); |
| |
| void Curl_cf_def_close(struct Curl_cfilter *cf, struct Curl_easy *data); |
| void Curl_conn_get_host(struct Curl_easy *data, int sockindex, |
| const char **phost, const char **pdisplay_host, |
| int *pport); |
| |
| /** |
| * Get the maximum number of parallel transfers the connection |
| * expects to be able to handle at `sockindex`. |
| */ |
| size_t Curl_conn_get_max_concurrent(struct Curl_easy *data, |
| struct connectdata *conn, |
| int sockindex); |
| |
| /** |
| * Get the underlying error code for a transfer stream or 0 if not known. |
| */ |
| int Curl_conn_get_stream_error(struct Curl_easy *data, |
| struct connectdata *conn, |
| int sockindex); |
| |
| /** |
| * Get the index of the given socket in the connection's sockets. |
| * Useful in calling `Curl_conn_send()/Curl_conn_recv()` with the |
| * correct socket index. |
| */ |
| int Curl_conn_sockindex(struct Curl_easy *data, curl_socket_t sockfd); |
| |
| /* |
| * Receive data on the connection, using FIRSTSOCKET/SECONDARYSOCKET. |
| * Will return CURLE_AGAIN iff blocked on receiving. |
| */ |
| CURLcode Curl_conn_recv(struct Curl_easy *data, int sockindex, |
| char *buf, size_t buffersize, |
| ssize_t *pnread); |
| |
| /* |
| * Send data on the connection, using FIRSTSOCKET/SECONDARYSOCKET. |
| * Will return CURLE_AGAIN iff blocked on sending. |
| */ |
| CURLcode Curl_conn_send(struct Curl_easy *data, int sockindex, |
| const void *buf, size_t blen, |
| size_t *pnwritten); |
| |
| |
| void Curl_pollset_reset(struct Curl_easy *data, |
| struct easy_pollset *ps); |
| |
| /* Change the poll flags (CURL_POLL_IN/CURL_POLL_OUT) to the poll set for |
| * socket `sock`. If the socket is not already part of the poll set, it |
| * will be added. |
| * If the socket is present and all poll flags are cleared, it will be removed. |
| */ |
| void Curl_pollset_change(struct Curl_easy *data, |
| struct easy_pollset *ps, curl_socket_t sock, |
| int add_flags, int remove_flags); |
| |
| void Curl_pollset_set(struct Curl_easy *data, |
| struct easy_pollset *ps, curl_socket_t sock, |
| bool do_in, bool do_out); |
| |
| #define Curl_pollset_add_in(data, ps, sock) \ |
| Curl_pollset_change((data), (ps), (sock), CURL_POLL_IN, 0) |
| #define Curl_pollset_add_out(data, ps, sock) \ |
| Curl_pollset_change((data), (ps), (sock), CURL_POLL_OUT, 0) |
| #define Curl_pollset_add_inout(data, ps, sock) \ |
| Curl_pollset_change((data), (ps), (sock), \ |
| CURL_POLL_IN|CURL_POLL_OUT, 0) |
| #define Curl_pollset_set_in_only(data, ps, sock) \ |
| Curl_pollset_change((data), (ps), (sock), \ |
| CURL_POLL_IN, CURL_POLL_OUT) |
| #define Curl_pollset_set_out_only(data, ps, sock) \ |
| Curl_pollset_change((data), (ps), (sock), \ |
| CURL_POLL_OUT, CURL_POLL_IN) |
| |
| void Curl_pollset_add_socks(struct Curl_easy *data, |
| struct easy_pollset *ps, |
| int (*get_socks_cb)(struct Curl_easy *data, |
| curl_socket_t *socks)); |
| |
| /** |
| * Check if the pollset, as is, wants to read and/or write regarding |
| * the given socket. |
| */ |
| void Curl_pollset_check(struct Curl_easy *data, |
| struct easy_pollset *ps, curl_socket_t sock, |
| bool *pwant_read, bool *pwant_write); |
| |
| /** |
| * Types and macros used to keep the current easy handle in filter calls, |
| * allowing for nested invocations. See #10336. |
| * |
| * `cf_call_data` is intended to be a member of the cfilter's `ctx` type. |
| * A filter defines the macro `CF_CTX_CALL_DATA` to give access to that. |
| * |
| * With all values 0, the default, this indicates that there is no cfilter |
| * call with `data` ongoing. |
| * Macro `CF_DATA_SAVE` preserves the current `cf_call_data` in a local |
| * variable and sets the `data` given, incrementing the `depth` counter. |
| * |
| * Macro `CF_DATA_RESTORE` restores the old values from the local variable, |
| * while checking that `depth` values are as expected (debug build), catching |
| * cases where a "lower" RESTORE was not called. |
| * |
| * Finally, macro `CF_DATA_CURRENT` gives the easy handle of the current |
| * invocation. |
| */ |
| struct cf_call_data { |
| struct Curl_easy *data; |
| #ifdef DEBUGBUILD |
| int depth; |
| #endif |
| }; |
| |
| /** |
| * define to access the `struct cf_call_data for a cfilter. Normally |
| * a member in the cfilter's `ctx`. |
| * |
| * #define CF_CTX_CALL_DATA(cf) -> struct cf_call_data instance |
| */ |
| |
| #ifdef DEBUGBUILD |
| |
| #define CF_DATA_SAVE(save, cf, data) \ |
| do { \ |
| (save) = CF_CTX_CALL_DATA(cf); \ |
| DEBUGASSERT((save).data == NULL || (save).depth > 0); \ |
| CF_CTX_CALL_DATA(cf).depth++; \ |
| CF_CTX_CALL_DATA(cf).data = (struct Curl_easy *)data; \ |
| } while(0) |
| |
| #define CF_DATA_RESTORE(cf, save) \ |
| do { \ |
| DEBUGASSERT(CF_CTX_CALL_DATA(cf).depth == (save).depth + 1); \ |
| DEBUGASSERT((save).data == NULL || (save).depth > 0); \ |
| CF_CTX_CALL_DATA(cf) = (save); \ |
| } while(0) |
| |
| #else /* DEBUGBUILD */ |
| |
| #define CF_DATA_SAVE(save, cf, data) \ |
| do { \ |
| (save) = CF_CTX_CALL_DATA(cf); \ |
| CF_CTX_CALL_DATA(cf).data = (struct Curl_easy *)data; \ |
| } while(0) |
| |
| #define CF_DATA_RESTORE(cf, save) \ |
| do { \ |
| CF_CTX_CALL_DATA(cf) = (save); \ |
| } while(0) |
| |
| #endif /* !DEBUGBUILD */ |
| |
| #define CF_DATA_CURRENT(cf) \ |
| ((cf)? (CF_CTX_CALL_DATA(cf).data) : NULL) |
| |
| #endif /* HEADER_CURL_CFILTERS_H */ |