curl/lib/cfilters.h

316 строки
13 KiB
C

#ifndef HEADER_CURL_CFILTERS_H
#define HEADER_CURL_CFILTERS_H
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2022, 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);
/* 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 */