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curl/lib/hostthre.c
Daniel Stenberg 91386937ff - Michael Wallner provided a patch that adds support for CURLOPT_TIMEOUT_MS
and CURLOPT_CONNECTTIMEOUT_MS that, as their names should hint, do the
  timeouts with millisecond resolution instead. The only restriction to that
  is the alarm() (sometimes) used to abort name resolves as that uses full
  seconds. I fixed the FTP response timeout part of the patch.

  Internally we now count and keep the timeouts in milliseconds but it also
  means we multiply set timeouts with 1000. The effect of this is that no
  timeout can be set to more than 2^31 milliseconds (on 32 bit systems), which
  equals 24.86 days.  We probably couldn't before either since the code did
  *1000 on the timeout values on several places already.
2007-02-05 22:51:32 +00:00

841 lines
24 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2007, 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 http://curl.haxx.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.
*
* $Id$
***************************************************************************/
#include "setup.h"
#include <string.h>
#include <errno.h>
#ifdef NEED_MALLOC_H
#include <malloc.h>
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h> /* required for free() prototypes */
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h> /* for the close() proto */
#endif
#ifdef VMS
#include <in.h>
#include <inet.h>
#include <stdlib.h>
#endif
#ifdef HAVE_SETJMP_H
#include <setjmp.h>
#endif
#ifdef HAVE_PROCESS_H
#include <process.h>
#endif
#if (defined(NETWARE) && defined(__NOVELL_LIBC__))
#undef in_addr_t
#define in_addr_t unsigned long
#endif
#include "urldata.h"
#include "sendf.h"
#include "hostip.h"
#include "hash.h"
#include "share.h"
#include "strerror.h"
#include "url.h"
#include "multiif.h"
#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>
#include "inet_ntop.h"
#include "memory.h"
/* The last #include file should be: */
#include "memdebug.h"
#if defined(_MSC_VER) && defined(CURL_NO__BEGINTHREADEX)
#pragma message ("No _beginthreadex() available in this RTL")
#endif
/***********************************************************************
* Only for Windows threaded name resolves builds
**********************************************************************/
#ifdef CURLRES_THREADED
/* This function is used to init a threaded resolve */
static bool init_resolve_thread(struct connectdata *conn,
const char *hostname, int port,
const Curl_addrinfo *hints);
#ifdef CURLRES_IPV4
#define THREAD_FUNC gethostbyname_thread
#define THREAD_NAME "gethostbyname_thread"
#else
#define THREAD_FUNC getaddrinfo_thread
#define THREAD_NAME "getaddrinfo_thread"
#endif
#if defined(DEBUG_THREADING_GETHOSTBYNAME) || \
defined(DEBUG_THREADING_GETADDRINFO)
/* If this is defined, provide tracing */
#define TRACE(args) \
do { trace_it("%u: ", __LINE__); trace_it args; } while (0)
static void trace_it (const char *fmt, ...)
{
static int do_trace = -1;
va_list args;
if (do_trace == -1) {
const char *env = getenv("CURL_TRACE");
do_trace = (env && atoi(env) > 0);
}
if (!do_trace)
return;
va_start (args, fmt);
vfprintf (stderr, fmt, args);
fflush (stderr);
va_end (args);
}
#else
#define TRACE(x)
#endif
#ifdef DEBUG_THREADING_GETADDRINFO
static void dump_addrinfo (struct connectdata *conn, const struct addrinfo *ai)
{
TRACE(("dump_addrinfo:\n"));
for ( ; ai; ai = ai->ai_next) {
char buf [INET6_ADDRSTRLEN];
trace_it(" fam %2d, CNAME %s, ",
ai->ai_family, ai->ai_canonname ? ai->ai_canonname : "<none>");
if (Curl_printable_address(ai, buf, sizeof(buf)))
trace_it("%s\n", buf);
else
trace_it("failed; %s\n", Curl_strerror(conn,WSAGetLastError()));
}
}
#endif
struct thread_data {
HANDLE thread_hnd;
unsigned thread_id;
DWORD thread_status;
curl_socket_t dummy_sock; /* dummy for Curl_resolv_fdset() */
HANDLE mutex_waiting; /* marks that we are still waiting for a resolve */
HANDLE event_resolved; /* marks that the thread obtained the information */
HANDLE event_thread_started; /* marks that the thread has initialized and
started */
HANDLE mutex_terminate; /* serializes access to flag_terminate */
HANDLE event_terminate; /* flag for thread to terminate instead of calling
callbacks */
#ifdef CURLRES_IPV6
struct addrinfo hints;
#endif
};
/* Data for synchronization between resolver thread and its parent */
struct thread_sync_data {
HANDLE mutex_waiting; /* thread_data.mutex_waiting duplicate */
HANDLE mutex_terminate; /* thread_data.mutex_terminate duplicate */
HANDLE event_terminate; /* thread_data.event_terminate duplicate */
char * hostname; /* hostname to resolve, Curl_async.hostname
duplicate */
};
/* Destroy resolver thread synchronization data */
static
void destroy_thread_sync_data(struct thread_sync_data * tsd)
{
if (tsd->hostname) {
free(tsd->hostname);
tsd->hostname = NULL;
}
if (tsd->event_terminate) {
CloseHandle(tsd->event_terminate);
tsd->event_terminate = NULL;
}
if (tsd->mutex_terminate) {
CloseHandle(tsd->mutex_terminate);
tsd->mutex_terminate = NULL;
}
if (tsd->mutex_waiting) {
CloseHandle(tsd->mutex_waiting);
tsd->mutex_waiting = NULL;
}
}
/* Initialize resolver thread synchronization data */
static
BOOL init_thread_sync_data(struct thread_data * td,
char * hostname,
struct thread_sync_data * tsd)
{
HANDLE curr_proc = GetCurrentProcess();
memset(tsd, 0, sizeof(*tsd));
if (!DuplicateHandle(curr_proc, td->mutex_waiting,
curr_proc, &tsd->mutex_waiting, 0, FALSE,
DUPLICATE_SAME_ACCESS)) {
/* failed to duplicate the mutex, no point in continuing */
destroy_thread_sync_data(tsd);
return FALSE;
}
if (!DuplicateHandle(curr_proc, td->mutex_terminate,
curr_proc, &tsd->mutex_terminate, 0, FALSE,
DUPLICATE_SAME_ACCESS)) {
/* failed to duplicate the mutex, no point in continuing */
destroy_thread_sync_data(tsd);
return FALSE;
}
if (!DuplicateHandle(curr_proc, td->event_terminate,
curr_proc, &tsd->event_terminate, 0, FALSE,
DUPLICATE_SAME_ACCESS)) {
/* failed to duplicate the event, no point in continuing */
destroy_thread_sync_data(tsd);
return FALSE;
}
/* Copying hostname string because original can be destroyed by parent
* thread during gethostbyname execution.
*/
tsd->hostname = strdup(hostname);
if (!tsd->hostname) {
/* Memory allocation failed */
destroy_thread_sync_data(tsd);
return FALSE;
}
return TRUE;
}
/* acquire resolver thread synchronization */
static
BOOL acquire_thread_sync(struct thread_sync_data * tsd)
{
/* is the thread initiator still waiting for us ? */
if (WaitForSingleObject(tsd->mutex_waiting, 0) == WAIT_TIMEOUT) {
/* yes, it is */
/* Waiting access to event_terminate */
if (WaitForSingleObject(tsd->mutex_terminate, INFINITE) != WAIT_OBJECT_0) {
/* Something went wrong - now just ignoring */
}
else {
if (WaitForSingleObject(tsd->event_terminate, 0) != WAIT_TIMEOUT) {
/* Parent thread signaled us to terminate.
* This means that all data in conn->async is now destroyed
* and we cannot use it.
*/
}
else {
return TRUE;
}
}
}
return FALSE;
}
/* release resolver thread synchronization */
static
void release_thread_sync(struct thread_sync_data * tsd)
{
ReleaseMutex(tsd->mutex_terminate);
}
#if defined(CURLRES_IPV4)
/*
* gethostbyname_thread() resolves a name, calls the Curl_addrinfo4_callback
* and then exits.
*
* For builds without ARES/ENABLE_IPV6, create a resolver thread and wait on
* it.
*/
static unsigned __stdcall gethostbyname_thread (void *arg)
{
struct connectdata *conn = (struct connectdata*) arg;
struct thread_data *td = (struct thread_data*) conn->async.os_specific;
struct hostent *he;
int rc = 0;
/* Duplicate the passed mutex and event handles.
* This allows us to use it even after the container gets destroyed
* due to a resolver timeout.
*/
struct thread_sync_data tsd = { 0,0,0,NULL };
if (!init_thread_sync_data(td, conn->async.hostname, &tsd)) {
/* thread synchronization data initialization failed */
return (unsigned)-1;
}
WSASetLastError (conn->async.status = NO_DATA); /* pending status */
/* Signaling that we have initialized all copies of data and handles we
need */
SetEvent(td->event_thread_started);
he = gethostbyname (tsd.hostname);
/* is parent thread waiting for us and are we able to access conn members? */
if (acquire_thread_sync(&tsd)) {
/* Mark that we have obtained the information, and that we are calling
* back with it. */
SetEvent(td->event_resolved);
if (he) {
rc = Curl_addrinfo4_callback(conn, CURL_ASYNC_SUCCESS, he);
}
else {
rc = Curl_addrinfo4_callback(conn, (int)WSAGetLastError(), NULL);
}
TRACE(("Winsock-error %d, addr %s\n", conn->async.status,
he ? inet_ntoa(*(struct in_addr*)he->h_addr) : "unknown"));
release_thread_sync(&tsd);
}
/* clean up */
destroy_thread_sync_data(&tsd);
return (rc);
/* An implicit _endthreadex() here */
}
#elif defined(CURLRES_IPV6)
/*
* getaddrinfo_thread() resolves a name, calls Curl_addrinfo6_callback and then
* exits.
*
* For builds without ARES, but with ENABLE_IPV6, create a resolver thread
* and wait on it.
*/
static unsigned __stdcall getaddrinfo_thread (void *arg)
{
struct connectdata *conn = (struct connectdata*) arg;
struct thread_data *td = (struct thread_data*) conn->async.os_specific;
struct addrinfo *res;
char service [NI_MAXSERV];
int rc;
struct addrinfo hints = td->hints;
/* Duplicate the passed mutex handle.
* This allows us to use it even after the container gets destroyed
* due to a resolver timeout.
*/
struct thread_sync_data tsd = { 0,0,0,NULL };
if (!init_thread_sync_data(td, conn->async.hostname, &tsd)) {
/* thread synchronization data initialization failed */
return -1;
}
itoa(conn->async.port, service, 10);
WSASetLastError(conn->async.status = NO_DATA); /* pending status */
/* Signaling that we have initialized all copies of data and handles we
need */
SetEvent(td->event_thread_started);
rc = getaddrinfo(tsd.hostname, service, &hints, &res);
/* is parent thread waiting for us and are we able to access conn members? */
if (acquire_thread_sync(&tsd)) {
/* Mark that we have obtained the information, and that we are calling
back with it. */
SetEvent(td->event_resolved);
if (rc == 0) {
#ifdef DEBUG_THREADING_GETADDRINFO
dump_addrinfo (conn, res);
#endif
rc = Curl_addrinfo6_callback(conn, CURL_ASYNC_SUCCESS, res);
}
else {
rc = Curl_addrinfo6_callback(conn, (int)WSAGetLastError(), NULL);
TRACE(("Winsock-error %d, no address\n", conn->async.status));
}
release_thread_sync(&tsd);
}
/* clean up */
destroy_thread_sync_data(&tsd);
return (rc);
/* An implicit _endthreadex() here */
}
#endif
/*
* Curl_destroy_thread_data() cleans up async resolver data and thread handle.
* Complementary of ares_destroy.
*/
void Curl_destroy_thread_data (struct Curl_async *async)
{
if (async->hostname)
free(async->hostname);
if (async->os_specific) {
struct thread_data *td = (struct thread_data*) async->os_specific;
curl_socket_t sock = td->dummy_sock;
if (td->mutex_terminate && td->event_terminate) {
/* Signaling resolver thread to terminate */
if (WaitForSingleObject(td->mutex_terminate, INFINITE) == WAIT_OBJECT_0) {
SetEvent(td->event_terminate);
ReleaseMutex(td->mutex_terminate);
}
else {
/* Something went wrong - just ignoring it */
}
}
if (td->mutex_terminate)
CloseHandle(td->mutex_terminate);
if (td->event_terminate)
CloseHandle(td->event_terminate);
if (td->event_thread_started)
CloseHandle(td->event_thread_started);
if (sock != CURL_SOCKET_BAD)
sclose(sock);
/* destroy the synchronization objects */
if (td->mutex_waiting)
CloseHandle(td->mutex_waiting);
td->mutex_waiting = NULL;
if (td->event_resolved)
CloseHandle(td->event_resolved);
if (td->thread_hnd)
CloseHandle(td->thread_hnd);
free(async->os_specific);
}
async->hostname = NULL;
async->os_specific = NULL;
}
/*
* init_resolve_thread() starts a new thread that performs the actual
* resolve. This function returns before the resolve is done.
*
* Returns FALSE in case of failure, otherwise TRUE.
*/
static bool init_resolve_thread (struct connectdata *conn,
const char *hostname, int port,
const Curl_addrinfo *hints)
{
struct thread_data *td = calloc(sizeof(*td), 1);
HANDLE thread_and_event[2] = {0};
if (!td) {
SetLastError(ENOMEM);
return FALSE;
}
Curl_safefree(conn->async.hostname);
conn->async.hostname = strdup(hostname);
if (!conn->async.hostname) {
free(td);
SetLastError(ENOMEM);
return FALSE;
}
conn->async.port = port;
conn->async.done = FALSE;
conn->async.status = 0;
conn->async.dns = NULL;
conn->async.os_specific = (void*) td;
td->dummy_sock = CURL_SOCKET_BAD;
/* Create the mutex used to inform the resolver thread that we're
* still waiting, and take initial ownership.
*/
td->mutex_waiting = CreateMutex(NULL, TRUE, NULL);
if (td->mutex_waiting == NULL) {
Curl_destroy_thread_data(&conn->async);
SetLastError(EAGAIN);
return FALSE;
}
/* Create the event that the thread uses to inform us that it's
* done resolving. Do not signal it.
*/
td->event_resolved = CreateEvent(NULL, TRUE, FALSE, NULL);
if (td->event_resolved == NULL) {
Curl_destroy_thread_data(&conn->async);
SetLastError(EAGAIN);
return FALSE;
}
/* Create the mutex used to serialize access to event_terminated
* between us and resolver thread.
*/
td->mutex_terminate = CreateMutex(NULL, FALSE, NULL);
if (td->mutex_terminate == NULL) {
Curl_destroy_thread_data(&conn->async);
SetLastError(EAGAIN);
return FALSE;
}
/* Create the event used to signal thread that it should terminate.
*/
td->event_terminate = CreateEvent(NULL, TRUE, FALSE, NULL);
if (td->event_terminate == NULL) {
Curl_destroy_thread_data(&conn->async);
SetLastError(EAGAIN);
return FALSE;
}
/* Create the event used by thread to inform it has initialized its own data.
*/
td->event_thread_started = CreateEvent(NULL, TRUE, FALSE, NULL);
if (td->event_thread_started == NULL) {
Curl_destroy_thread_data(&conn->async);
SetLastError(EAGAIN);
return FALSE;
}
#ifdef _WIN32_WCE
td->thread_hnd = (HANDLE) CreateThread(NULL, 0,
(LPTHREAD_START_ROUTINE) THREAD_FUNC,
conn, 0, &td->thread_id);
#else
td->thread_hnd = (HANDLE) _beginthreadex(NULL, 0, THREAD_FUNC,
conn, 0, &td->thread_id);
#endif
#ifdef CURLRES_IPV6
curlassert(hints);
td->hints = *hints;
#else
(void) hints;
#endif
if (!td->thread_hnd) {
#ifdef _WIN32_WCE
TRACE(("CreateThread() failed; %s\n", Curl_strerror(conn,GetLastError())));
#else
SetLastError(errno);
TRACE(("_beginthreadex() failed; %s\n", Curl_strerror(conn,errno)));
#endif
Curl_destroy_thread_data(&conn->async);
return FALSE;
}
/* Waiting until the thread will initialize its data or it will exit due errors.
*/
thread_and_event[0] = td->thread_hnd;
thread_and_event[1] = td->event_thread_started;
if (WaitForMultipleObjects(sizeof(thread_and_event) /
sizeof(thread_and_event[0]),
(const HANDLE*)thread_and_event, FALSE,
INFINITE) == WAIT_FAILED) {
/* The resolver thread has been created,
* most probably it works now - ignoring this "minor" error
*/
}
/* This socket is only to keep Curl_resolv_fdset() and select() happy;
* should never become signalled for read/write since it's unbound but
* Windows needs atleast 1 socket in select().
*/
td->dummy_sock = socket(AF_INET, SOCK_DGRAM, 0);
return TRUE;
}
/*
* Curl_wait_for_resolv() waits for a resolve to finish. This function should
* be avoided since using this risk getting the multi interface to "hang".
*
* If 'entry' is non-NULL, make it point to the resolved dns entry
*
* This is the version for resolves-in-a-thread.
*/
CURLcode Curl_wait_for_resolv(struct connectdata *conn,
struct Curl_dns_entry **entry)
{
struct thread_data *td = (struct thread_data*) conn->async.os_specific;
struct SessionHandle *data = conn->data;
long timeout;
DWORD status, ticks;
CURLcode rc;
curlassert (conn && td);
/* now, see if there's a connect timeout or a regular timeout to
use instead of the default one */
timeout =
conn->data->set.connecttimeout ? conn->data->set.connecttimeout :
conn->data->set.timeout ? conn->data->set.timeout :
CURL_TIMEOUT_RESOLVE; /* default name resolve timeout */
ticks = GetTickCount();
/* wait for the thread to resolve the name */
status = WaitForSingleObject(td->event_resolved, timeout);
/* mark that we are now done waiting */
ReleaseMutex(td->mutex_waiting);
/* close our handle to the mutex, no point in hanging on to it */
CloseHandle(td->mutex_waiting);
td->mutex_waiting = NULL;
/* close the event handle, it's useless now */
CloseHandle(td->event_resolved);
td->event_resolved = NULL;
/* has the resolver thread succeeded in resolving our query ? */
if (status == WAIT_OBJECT_0) {
/* wait for the thread to exit, it's in the callback sequence */
if (WaitForSingleObject(td->thread_hnd, 5000) == WAIT_TIMEOUT) {
TerminateThread(td->thread_hnd, 0);
conn->async.done = TRUE;
td->thread_status = (DWORD)-1;
TRACE(("%s() thread stuck?!, ", THREAD_NAME));
}
else {
/* Thread finished before timeout; propagate Winsock error to this
* thread. 'conn->async.done = TRUE' is set in
* Curl_addrinfo4/6_callback().
*/
WSASetLastError(conn->async.status);
GetExitCodeThread(td->thread_hnd, &td->thread_status);
TRACE(("%s() status %lu, thread retval %lu, ",
THREAD_NAME, status, td->thread_status));
}
}
else {
conn->async.done = TRUE;
td->thread_status = (DWORD)-1;
TRACE(("%s() timeout, ", THREAD_NAME));
}
TRACE(("elapsed %lu ms\n", GetTickCount()-ticks));
if(entry)
*entry = conn->async.dns;
rc = CURLE_OK;
if (!conn->async.dns) {
/* a name was not resolved */
if (td->thread_status == CURLE_OUT_OF_MEMORY) {
rc = CURLE_OUT_OF_MEMORY;
failf(data, "Could not resolve host: %s", curl_easy_strerror(rc));
}
else if(conn->async.done) {
if(conn->bits.httpproxy) {
failf(data, "Could not resolve proxy: %s; %s",
conn->proxy.dispname, Curl_strerror(conn, conn->async.status));
rc = CURLE_COULDNT_RESOLVE_PROXY;
}
else {
failf(data, "Could not resolve host: %s; %s",
conn->host.name, Curl_strerror(conn, conn->async.status));
rc = CURLE_COULDNT_RESOLVE_HOST;
}
}
else if (td->thread_status == (DWORD)-1 || conn->async.status == NO_DATA) {
failf(data, "Resolving host timed out: %s", conn->host.name);
rc = CURLE_OPERATION_TIMEDOUT;
}
else
rc = CURLE_OPERATION_TIMEDOUT;
}
Curl_destroy_thread_data(&conn->async);
if(!conn->async.dns)
conn->bits.close = TRUE;
return (rc);
}
/*
* Curl_is_resolved() is 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.
*/
CURLcode Curl_is_resolved(struct connectdata *conn,
struct Curl_dns_entry **entry)
{
*entry = NULL;
if (conn->async.done) {
/* we're done */
Curl_destroy_thread_data(&conn->async);
if (!conn->async.dns) {
TRACE(("Curl_is_resolved(): CURLE_COULDNT_RESOLVE_HOST\n"));
return CURLE_COULDNT_RESOLVE_HOST;
}
*entry = conn->async.dns;
TRACE(("resolved okay, dns %p\n", *entry));
}
return CURLE_OK;
}
int Curl_resolv_getsock(struct connectdata *conn,
curl_socket_t *socks,
int numsocks)
{
const struct thread_data *td =
(const struct thread_data *) conn->async.os_specific;
if (td && td->dummy_sock != CURL_SOCKET_BAD) {
if(numsocks) {
/* return one socket waiting for writable, even though this is just
a dummy */
socks[0] = td->dummy_sock;
return GETSOCK_WRITESOCK(0);
}
}
return 0;
}
#ifdef CURLRES_IPV4
/*
* Curl_getaddrinfo() - for Windows threading without ENABLE_IPV6.
*/
Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
const char *hostname,
int port,
int *waitp)
{
struct hostent *h = NULL;
struct SessionHandle *data = conn->data;
in_addr_t in;
*waitp = 0; /* don't wait, we act synchronously */
in = inet_addr(hostname);
if (in != CURL_INADDR_NONE)
/* This is a dotted IP address 123.123.123.123-style */
return Curl_ip2addr(in, hostname, port);
/* fire up a new resolver thread! */
if (init_resolve_thread(conn, hostname, port, NULL)) {
*waitp = TRUE; /* please wait for the response */
return NULL;
}
/* fall-back to blocking version */
infof(data, "init_resolve_thread() failed for %s; %s\n",
hostname, Curl_strerror(conn,GetLastError()));
h = gethostbyname(hostname);
if (!h) {
infof(data, "gethostbyname(2) failed for %s:%d; %s\n",
hostname, port, Curl_strerror(conn,WSAGetLastError()));
return NULL;
}
return Curl_he2ai(h, port);
}
#endif /* CURLRES_IPV4 */
#ifdef CURLRES_IPV6
/*
* Curl_getaddrinfo() - for Windows threading IPv6 enabled
*/
Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
const char *hostname,
int port,
int *waitp)
{
struct addrinfo hints, *res;
int error;
char sbuf[NI_MAXSERV];
curl_socket_t s;
int pf;
struct SessionHandle *data = conn->data;
*waitp = FALSE; /* default to synch response */
/* see if we have an IPv6 stack */
s = socket(PF_INET6, SOCK_DGRAM, 0);
if (s == CURL_SOCKET_BAD) {
/* Some non-IPv6 stacks have been found to make very slow name resolves
* when PF_UNSPEC is used, so thus we switch to a mere PF_INET lookup if
* the stack seems to be a non-ipv6 one. */
pf = PF_INET;
}
else {
/* This seems to be an IPv6-capable stack, use PF_UNSPEC for the widest
* possible checks. And close the socket again.
*/
sclose(s);
/*
* Check if a more limited name resolve has been requested.
*/
switch(data->set.ip_version) {
case CURL_IPRESOLVE_V4:
pf = PF_INET;
break;
case CURL_IPRESOLVE_V6:
pf = PF_INET6;
break;
default:
pf = PF_UNSPEC;
break;
}
}
memset(&hints, 0, sizeof(hints));
hints.ai_family = pf;
hints.ai_socktype = conn->socktype;
#if 0 /* removed nov 8 2005 before 7.15.1 */
hints.ai_flags = AI_CANONNAME;
#endif
itoa(port, sbuf, 10);
/* fire up a new resolver thread! */
if (init_resolve_thread(conn, hostname, port, &hints)) {
*waitp = TRUE; /* please wait for the response */
return NULL;
}
/* fall-back to blocking version */
infof(data, "init_resolve_thread() failed for %s; %s\n",
hostname, Curl_strerror(conn,GetLastError()));
error = getaddrinfo(hostname, sbuf, &hints, &res);
if (error) {
infof(data, "getaddrinfo() failed for %s:%d; %s\n",
hostname, port, Curl_strerror(conn,WSAGetLastError()));
return NULL;
}
return res;
}
#endif /* CURLRES_IPV6 */
#endif /* CURLRES_THREADED */