curl/lib/connect.h

#ifndef HEADER_CURL_CONNECT_H
#define HEADER_CURL_CONNECT_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
 *
 ***************************************************************************/
#include "curl_setup.h"

#include "nonblock.h" /* for curlx_nonblock(), formerly Curl_nonblock() */
#include "sockaddr.h"
#include "timeval.h"

struct Curl_dns_entry;

/* generic function that returns how much time there's left to run, according
   to the timeouts set */
timediff_t Curl_timeleft(struct Curl_easy *data,
                         struct curltime *nowp,
                         bool duringconnect);

#define DEFAULT_CONNECT_TIMEOUT 300000 /* milliseconds == five minutes */

/*
 * Used to extract socket and connectdata struct for the most recent
 * transfer on the given Curl_easy.
 *
 * The returned socket will be CURL_SOCKET_BAD in case of failure!
 */
curl_socket_t Curl_getconnectinfo(struct Curl_easy *data,
                                  struct connectdata **connp);

bool Curl_addr2string(struct sockaddr *sa, curl_socklen_t salen,
                      char *addr, int *port);

void Curl_persistconninfo(struct Curl_easy *data, struct connectdata *conn,
                          char *local_ip, int local_port);

/*
 * Curl_conncontrol() marks the end of a connection/stream. The 'closeit'
 * argument specifies if it is the end of a connection or a stream.
 *
 * For stream-based protocols (such as HTTP/2), a stream close will not cause
 * a connection close. Other protocols will close the connection for both
 * cases.
 *
 * It sets the bit.close bit to TRUE (with an explanation for debug builds),
 * when the connection will close.
 */

#define CONNCTRL_KEEP 0 /* undo a marked closure */
#define CONNCTRL_CONNECTION 1
#define CONNCTRL_STREAM 2

void Curl_conncontrol(struct connectdata *conn,
                      int closeit
#if defined(DEBUGBUILD) && !defined(CURL_DISABLE_VERBOSE_STRINGS)
                      , const char *reason
#endif
  );

#if defined(DEBUGBUILD) && !defined(CURL_DISABLE_VERBOSE_STRINGS)
#define streamclose(x,y) Curl_conncontrol(x, CONNCTRL_STREAM, y)
#define connclose(x,y) Curl_conncontrol(x, CONNCTRL_CONNECTION, y)
#define connkeep(x,y) Curl_conncontrol(x, CONNCTRL_KEEP, y)
#else /* if !DEBUGBUILD || CURL_DISABLE_VERBOSE_STRINGS */
#define streamclose(x,y) Curl_conncontrol(x, CONNCTRL_STREAM)
#define connclose(x,y) Curl_conncontrol(x, CONNCTRL_CONNECTION)
#define connkeep(x,y) Curl_conncontrol(x, CONNCTRL_KEEP)
#endif

/**
 * Create a cfilter for making an "ip" connection to the
 * given address, using parameters from `conn`. The "ip" connection
 * can be a TCP socket, a UDP socket or even a QUIC connection.
 *
 * It MUST use only the supplied `ai` for its connection attempt.
 *
 * Such a filter may be used in "happy eyeball" scenarios, and its
 * `connect` implementation needs to support non-blocking. Once connected,
 * it MAY be installed in the connection filter chain to serve transfers.
 */
typedef CURLcode cf_ip_connect_create(struct Curl_cfilter **pcf,
                                      struct Curl_easy *data,
                                      struct connectdata *conn,
                                      const struct Curl_addrinfo *ai,
                                      int transport);

/**
 * Create a happy eyeball connection filter that uses the, once resolved,
 * address information to connect on ip families based on connection
 * configuration.
 * @param pcf        output, the created cfilter
 * @param data       easy handle used in creation
 * @param conn       connection the filter is created for
 * @param cf_create  method to create the sub-filters performing the
 *                   actual connects.
 */
CURLcode
Curl_cf_happy_eyeballs_create(struct Curl_cfilter **pcf,
                              struct Curl_easy *data,
                              struct connectdata *conn,
                              cf_ip_connect_create *cf_create,
                              const struct Curl_dns_entry *remotehost,
                              int transport);

CURLcode Curl_cf_setup_add(struct Curl_easy *data,
                           struct connectdata *conn,
                           int sockindex,
                           const struct Curl_dns_entry *remotehost,
                           int transport,
                           int ssl_mode);

CURLcode Curl_cf_setup_insert_after(struct Curl_cfilter *cf_at,
                                    struct Curl_easy *data,
                                    const struct Curl_dns_entry *remotehost,
                                    int transport,
                                    int ssl_mode);

/**
 * Setup the cfilters at `sockindex` in connection `conn`.
 * If no filter chain is installed yet, inspects the configuration
 * in `data` and `conn? 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);

extern struct Curl_cftype Curl_cft_happy_eyeballs;
extern struct Curl_cftype Curl_cft_setup;

#ifdef DEBUGBUILD
void Curl_debug_set_transport_provider(int transport,
                                       cf_ip_connect_create *cf_create);
#endif

#endif /* HEADER_CURL_CONNECT_H */