279 lines
8.6 KiB
C

#ifndef HEADER_CURL_ASYN_H
#define HEADER_CURL_ASYN_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"
struct Curl_easy;
struct Curl_dns_entry;
#ifdef CURLRES_ASYNCH
#include "curl_addrinfo.h"
#include "httpsrr.h"
struct addrinfo;
struct hostent;
struct connectdata;
struct easy_pollset;
#if defined(CURLRES_ARES) && defined(CURLRES_THREADED)
#error cannot have both CURLRES_ARES and CURLRES_THREADED defined
#endif
/*
* This header defines all functions in the internal asynch resolver interface.
* All asynch resolvers need to provide these functions.
* asyn-ares.c and asyn-thread.c are the current implementations of asynch
* resolver backends.
*/
/*
* Curl_async_global_init()
*
* Called from curl_global_init() to initialize global resolver environment.
* Returning anything else than CURLE_OK fails curl_global_init().
*/
int Curl_async_global_init(void);
/*
* Curl_async_global_cleanup()
* Called from curl_global_cleanup() to destroy global resolver environment.
*/
void Curl_async_global_cleanup(void);
/*
* Curl_async_get_impl()
* Get the resolver implementation instance (c-ares channel) or NULL
* for passing to application callback.
*/
CURLcode Curl_async_get_impl(struct Curl_easy *easy, void **impl);
/* Curl_async_pollset()
*
* This function is called from the Curl_multi_pollset() function. 'sock' is a
* pointer to an array to hold the file descriptors, with 'numsock' being the
* size of that array (in number of entries). This function is supposed to
* return bitmask indicating what file descriptors (referring to array indexes
* in the 'sock' array) to wait for, read/write.
*/
CURLcode Curl_async_pollset(struct Curl_easy *data, struct easy_pollset *ps);
/*
* Curl_async_is_resolved()
*
* Called repeatedly to check if a previous name resolve request has
* completed. It should also make sure to time-out if the operation seems to
* take too long.
*
* Returns normal CURLcode errors.
*/
CURLcode Curl_async_is_resolved(struct Curl_easy *data,
struct Curl_dns_entry **dns);
/*
* Curl_async_await()
*
* Waits for a resolve to finish. This function should be avoided since using
* this risk getting the multi interface to "hang".
*
* On return 'entry' is assigned the resolved dns (CURLE_OK or NULL otherwise.
*
* Returns CURLE_COULDNT_RESOLVE_HOST if the host was not resolved,
* CURLE_OPERATION_TIMEDOUT if a time-out occurred, or other errors.
*/
CURLcode Curl_async_await(struct Curl_easy *data,
struct Curl_dns_entry **dnsentry);
/*
* Curl_async_getaddrinfo() - when using this resolver
*
* Returns name information about the given hostname and port number. If
* successful, the 'hostent' is returned and the fourth argument will point to
* memory we need to free after use. That memory *MUST* be freed with
* Curl_freeaddrinfo(), nothing else.
*
* Each resolver backend must of course make sure to return data in the
* correct format to comply with this.
*/
struct Curl_addrinfo *Curl_async_getaddrinfo(struct Curl_easy *data,
const char *hostname,
int port,
int ip_version,
int *waitp);
#ifdef USE_ARES
/* common functions for c-ares and threaded resolver with HTTPSRR */
#include <ares.h>
CURLcode Curl_ares_pollset(struct Curl_easy *data,
ares_channel channel,
struct easy_pollset *ps);
int Curl_ares_perform(ares_channel channel,
timediff_t timeout_ms);
#endif
#ifdef CURLRES_ARES
/* async resolving implementation using c-ares alone */
struct async_ares_ctx {
ares_channel channel;
int num_pending; /* number of outstanding c-ares requests */
struct Curl_addrinfo *temp_ai; /* intermediary result while fetching c-ares
parts */
int ares_status; /* ARES_SUCCESS, ARES_ENOTFOUND, etc. */
CURLcode result; /* CURLE_OK or error handling response */
#ifndef HAVE_CARES_GETADDRINFO
struct curltime happy_eyeballs_dns_time; /* when this timer started, or 0 */
#endif
#ifdef USE_HTTPSRR
struct Curl_https_rrinfo hinfo;
#endif
};
void Curl_async_ares_shutdown(struct Curl_easy *data);
void Curl_async_ares_destroy(struct Curl_easy *data);
/* Set the DNS server to use by ares, from `data` settings. */
CURLcode Curl_async_ares_set_dns_servers(struct Curl_easy *data);
/* Set the DNS interfacer to use by ares, from `data` settings. */
CURLcode Curl_async_ares_set_dns_interface(struct Curl_easy *data);
/* Set the local ipv4 address to use by ares, from `data` settings. */
CURLcode Curl_async_ares_set_dns_local_ip4(struct Curl_easy *data);
/* Set the local ipv6 address to use by ares, from `data` settings. */
CURLcode Curl_async_ares_set_dns_local_ip6(struct Curl_easy *data);
#endif /* CURLRES_ARES */
#ifdef CURLRES_THREADED
/* async resolving implementation using POSIX threads */
#include "curl_threads.h"
/* Context for threaded address resolver */
struct async_thrdd_addr_ctx {
curl_thread_t thread_hnd;
char *hostname; /* hostname to resolve, Curl_async.hostname
duplicate */
curl_mutex_t mutx;
#ifndef CURL_DISABLE_SOCKETPAIR
curl_socket_t sock_pair[2]; /* eventfd/pipes/socket pair */
#endif
struct Curl_addrinfo *res;
#ifdef HAVE_GETADDRINFO
struct addrinfo hints;
#endif
struct curltime start;
timediff_t interval_end;
unsigned int poll_interval;
int port;
int sock_error;
int ref_count;
BIT(thrd_done);
BIT(do_abort);
};
/* Context for threaded resolver */
struct async_thrdd_ctx {
/* `addr` is a pointer since this memory is shared with a started
* thread. Since threads cannot be killed, we use reference counting
* so that we can "release" our pointer to this memory while the
* thread is still running. */
struct async_thrdd_addr_ctx *addr;
#if defined(USE_HTTPSRR) && defined(USE_ARES)
struct {
ares_channel channel;
struct Curl_https_rrinfo hinfo;
CURLcode result;
BIT(done);
} rr;
#endif
};
void Curl_async_thrdd_shutdown(struct Curl_easy *data);
void Curl_async_thrdd_destroy(struct Curl_easy *data);
#endif /* CURLRES_THREADED */
#ifndef CURL_DISABLE_DOH
struct doh_probes;
#endif
#else /* CURLRES_ASYNCH */
/* convert these functions if an asynch resolver is not used */
#define Curl_async_get_impl(x,y) (*(y) = NULL, CURLE_OK)
#define Curl_async_is_resolved(x,y) CURLE_COULDNT_RESOLVE_HOST
#define Curl_async_await(x,y) CURLE_COULDNT_RESOLVE_HOST
#define Curl_async_global_init() CURLE_OK
#define Curl_async_global_cleanup() Curl_nop_stmt
#endif /* !CURLRES_ASYNCH */
#if defined(CURLRES_ASYNCH) || !defined(CURL_DISABLE_DOH)
#define USE_CURL_ASYNC
#endif
#ifdef USE_CURL_ASYNC
struct Curl_async {
#ifdef CURLRES_ARES
struct async_ares_ctx ares;
#elif defined(CURLRES_THREADED)
struct async_thrdd_ctx thrdd;
#endif
#ifndef CURL_DISABLE_DOH
struct doh_probes *doh; /* DoH specific data for this request */
#endif
struct Curl_dns_entry *dns; /* result of resolving on success */
char *hostname; /* copy of the params resolv started with */
int port;
int ip_version;
BIT(done);
};
/*
* Curl_async_shutdown().
*
* This shuts down all ongoing operations.
*/
void Curl_async_shutdown(struct Curl_easy *data);
/*
* Curl_async_destroy().
*
* This frees the resources of any async resolve.
*/
void Curl_async_destroy(struct Curl_easy *data);
#else /* !USE_CURL_ASYNC */
#define Curl_async_shutdown(x) Curl_nop_stmt
#define Curl_async_destroy(x) Curl_nop_stmt
#endif /* USE_CURL_ASYNC */
/********** end of generic resolver interface functions *****************/
#endif /* HEADER_CURL_ASYN_H */