/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) 1998 - 2004, Daniel Stenberg, , 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: hostthre.c,v 1.14 2004/10/16 12:59:05 giva Exp $ ***************************************************************************/ #include "setup.h" #include #include #define _REENTRANT #if defined( WIN32 ) && !defined( __GNUC__ ) || defined( __MINGW32__ ) #include #else #ifdef HAVE_SYS_TYPES_H #include #endif #ifdef HAVE_SYS_SOCKET_H #include #endif #ifdef HAVE_NETINET_IN_H #include #endif #ifdef HAVE_NETDB_H #include #endif #ifdef HAVE_ARPA_INET_H #include #endif #ifdef HAVE_STDLIB_H #include /* required for free() prototypes */ #endif #ifdef HAVE_UNISTD_H #include /* for the close() proto */ #endif #ifdef VMS #include #include #include #endif #endif #ifdef HAVE_SETJMP_H #include #endif #ifdef WIN32 #include #include #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" #define _MPRINTF_REPLACE /* use our functions only */ #include #include "inet_ntop.h" #include "memory.h" /* The last #include file should be: */ #include "memdebug.h" /*********************************************************************** * 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 : "" ); 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_fdset() */ FILE *stderr_file; HANDLE mutex_waiting; /* marks that we are still waiting for a resolve */ HANDLE event_resolved; /* marks that the thread obtained the information */ #ifdef CURLRES_IPV6 struct addrinfo hints; #endif }; #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 handle. * This allows us to use it even after the container gets destroyed * due to a resolver timeout. */ HANDLE mutex_waiting = NULL; if ( !DuplicateHandle( GetCurrentProcess(), td->mutex_waiting, GetCurrentProcess(), &mutex_waiting, 0, FALSE, DUPLICATE_SAME_ACCESS ) ) { /* failed to duplicate the mutex, no point in continuing */ return 0; } /* Sharing the same _iob[] element with our parent thread should * hopefully make printouts synchronised. I'm not sure it works * with a static runtime lib (MSVC's libc.lib). */ *stderr = *td->stderr_file; WSASetLastError( conn->async.status = NO_DATA ); /* pending status */ he = gethostbyname( conn->async.hostname ); /* is the thread initiator still waiting for us ? */ if ( WaitForSingleObject( mutex_waiting, 0 ) == WAIT_TIMEOUT ) { /* yes, it is */ /* Mark that we have obtained the information, and that we are * calling back with it. */ SetEvent( td->event_resolved ); if ( he ) { Curl_addrinfo4_callback( conn, CURL_ASYNC_SUCCESS, he ); rc = 1; } else { Curl_addrinfo4_callback( conn, (int)WSAGetLastError(), NULL ); rc = 0; } TRACE( ( "Winsock-error %d, addr %s\n", conn->async.status, he ? inet_ntoa( *(struct in_addr*)he->h_addr ) : "unknown" ) ); } /* clean up */ CloseHandle( mutex_waiting ); 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; /* Duplicate the passed mutex handle. * This allows us to use it even after the container gets destroyed * due to a resolver timeout. */ HANDLE mutex_waiting = NULL; if ( !DuplicateHandle( GetCurrentProcess(), td->mutex_waiting, GetCurrentProcess(), &mutex_waiting, 0, FALSE, DUPLICATE_SAME_ACCESS ) ) { /* failed to duplicate the mutex, no point in continuing */ return 0; } *stderr = *td->stderr_file; itoa( conn->async.port, service, 10 ); WSASetLastError( conn->async.status = NO_DATA ); /* pending status */ rc = getaddrinfo( conn->async.hostname, service, &td->hints, &res ); /* is the thread initiator still waiting for us ? */ if ( WaitForSingleObject( mutex_waiting, 0 ) == WAIT_TIMEOUT ) { /* yes, it is */ /* 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 Curl_addrinfo6_callback( conn, CURL_ASYNC_SUCCESS, res ); } else { Curl_addrinfo6_callback( conn, (int)WSAGetLastError(), NULL ); TRACE( ( "Winsock-error %d, no address\n", conn->async.status ) ); } } /* clean up */ CloseHandle( mutex_waiting ); return ( rc ); /* An implicit _endthreadex() here */ } #endif /* * destroy_thread_data() cleans up async resolver data. * Complementary of ares_destroy. */ static void 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 ( sock != CURL_SOCKET_BAD ) { sclose( sock ); } /* destroy the synchronization objects */ if ( td->mutex_waiting ) { CloseHandle( td->mutex_waiting ); } if ( td->event_resolved ) { CloseHandle( td->event_resolved ); } 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 ); 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 ) { 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 ) { destroy_thread_data( &conn->async ); SetLastError( EAGAIN ); return FALSE; } td->stderr_file = stderr; td->thread_hnd = (HANDLE) _beginthreadex( NULL, 0, THREAD_FUNC, conn, 0, &td->thread_id ); #ifdef CURLRES_IPV6 curlassert( hints ); td->hints = *hints; #else (void) hints; #endif if ( !td->thread_hnd ) { SetLastError( errno ); TRACE( ( "_beginthreadex() failed; %s\n", Curl_strerror( conn,errno ) ) ); destroy_thread_data( &conn->async ); return FALSE; } /* This socket is only to keep Curl_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, 1000UL * 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 ) ); CloseHandle( td->thread_hnd ); if ( entry ) { *entry = conn->async.dns; } rc = CURLE_OK; if ( !conn->async.dns ) { /* a name was not resolved */ 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 if ( conn->async.done ) { failf( data, "Could not resolve host: %s; %s", conn->host.name, Curl_strerror( conn,conn->async.status ) ); rc = CURLE_COULDNT_RESOLVE_HOST; } else { rc = CURLE_OPERATION_TIMEDOUT; } } destroy_thread_data( &conn->async ); if ( CURLE_OK != rc ) { /* close the connection, since we must not return failure from here without cleaning up this connection properly */ Curl_disconnect( conn ); } 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 */ 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 ) ); } else { TRACE( ( "not yet\n" ) ); } return CURLE_OK; } CURLcode Curl_fdset( struct connectdata *conn, fd_set *read_fd_set, fd_set *write_fd_set, int *max_fdp ) { const struct thread_data *td = (const struct thread_data *) conn->async.os_specific; if ( td && td->dummy_sock != CURL_SOCKET_BAD ) { FD_SET( td->dummy_sock,write_fd_set ); *max_fdp = td->dummy_sock; } (void) read_fd_set; return CURLE_OK; } #ifdef CURLRES_IPV4 /* * Curl_getaddrinfo() - for Windows threading without ENABLE_IPV6. */ Curl_addrinfo *Curl_getaddrinfo( struct connectdata *conn, 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, 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 = SOCK_STREAM; hints.ai_flags = AI_CANONNAME; 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 */