/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) 1998 - 2009, 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 1.59 2009-04-21 11:46:16 yangtse Exp $ ***************************************************************************/ /* to get defines for error-checking mutexes */ #define _XOPEN_SOURCE 500 /* Needed for NI_MAXSERV - default normally but _XOPEN_SOURCE disables it*/ #ifdef __APPLE__ # define _DARWIN_C_SOURCE #else # define _BSD_SOURCE #endif #include "setup.h" #include #include #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 #ifdef HAVE_PTHREAD #include #endif #ifdef HAVE_PROCESS_H #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" #include "multiif.h" #include "inet_pton.h" #define _MPRINTF_REPLACE /* use our functions only */ #include #include "inet_ntop.h" #include "curl_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 and Mac 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 struct addrinfo *hints); #ifdef CURLRES_IPV4 #define THREAD_FUNC gethostbyname_thread #define COMPLETE_FUNC gethostbyname_complete #define THREAD_NAME "gethostbyname_thread" #else #define THREAD_FUNC getaddrinfo_thread #define COMPLETE_FUNC getaddrinfo_complete #define THREAD_NAME "getaddrinfo_thread" #endif /* Here's where we abstract everything out. */ #ifdef _WIN32 typedef HANDLE curl_thread_t; typedef CRITICAL_SECTION curl_mutex_t; static curl_thread_t curl_thread_t_null = NULL; #define CURL_STDCALL __stdcall static curl_thread_t curl_thread_create(unsigned int (__stdcall *func) (void*), void *arg) { #ifdef _WIN32_WCE return CreateThread(NULL, 0, func, arg, 0, NULL); #else return (curl_thread_t)_beginthreadex(NULL, 0, func, arg, 0, NULL); #endif } static void curl_thread_destroy(curl_thread_t hnd) { CloseHandle(hnd); } static int curl_thread_join(curl_thread_t * hnd) { int ret = (WaitForSingleObject(*hnd, INFINITE) == WAIT_OBJECT_0); curl_thread_destroy(*hnd); *hnd = curl_thread_t_null; return ret; } static void curl_mutex_init(curl_mutex_t * mtx) { InitializeCriticalSection(mtx); } static void curl_mutex_acquire(curl_mutex_t * mtx) { EnterCriticalSection(mtx); } static void curl_mutex_release(curl_mutex_t * mtx) { LeaveCriticalSection(mtx); } static void curl_mutex_destroy(curl_mutex_t * mtx) { DeleteCriticalSection(mtx); } #else typedef pthread_t curl_thread_t; typedef pthread_mutex_t curl_mutex_t; /* XXX - can a pthread_t ever be null */ static curl_thread_t curl_thread_t_null = 0; #define CURL_STDCALL static thread_handle curl_thread_create(unsigned int (*func) (void*), void *arg) { curl_thread_t t; if (pthread_create(&t, NULL, func, arg) != 0) return curl_thread_t_null; return t; } static int curl_thread_join(curl_thread_t *hnd) { int ret = (pthread_join(*hnd, NULL) == 0); *hnd = curl_thread_t_null; return ret; } static void curl_thread_destroy(thread_handle hnd) { // No-op for pthreads } static void curl_mutex_init(curl_mutex_t * mtx) { pthread_mutex_init(mtx, NULL); } static void curl_mutex_acquire(curl_mutex_t * mtx) { pthread_mutex_lock(mtx); } static void curl_mutex_release(curl_mutex_t * mtx) { pthread_mutex_unlock(mtx); } static void curl_mutex_destroy(curl_mutex_t * mtx) { pthread_mutex_destroy(mtx); } #endif /* Data for synchronization between resolver thread and its parent */ struct thread_sync_data { curl_mutex_t * mtx; int done; char * hostname; /* hostname to resolve, Curl_async.hostname duplicate */ int port; int sock_error; int rc; struct hostent he; Curl_addrinfo *res; #ifdef CURLRES_IPV6 struct addrinfo hints; #endif }; struct thread_data { curl_thread_t thread_hnd; curl_socket_t dummy_sock; unsigned int poll_interval; int interval_end; struct thread_sync_data tsd; }; static struct thread_sync_data * conn_thread_sync_data(struct connectdata *conn) { return &(((struct thread_data *)conn->async.os_specific)->tsd); } #define CONN_THREAD_SYNC_DATA(conn) &(((conn)->async.os_specific)->tsd); static void hostent_dup_free(struct hostent *dst) { int i; if (dst->h_name) { free(dst->h_name); dst->h_name = NULL; } if (dst->h_aliases) { for (i = 0; ; ++i) { if (dst->h_aliases[i]) free(dst->h_aliases[i]); else break; } free(dst->h_aliases); dst->h_aliases = NULL; } if (dst->h_addr_list) { for(i = 0; ; ++i) { if (dst->h_addr_list[i]) free(dst->h_addr_list[i]); else break; } free(dst->h_addr_list); dst->h_addr_list = NULL; } } static int hostent_dup(struct hostent *dst, struct hostent * src) { int i, n; memset(dst, 0, sizeof(*dst)); if (src->h_name) { dst->h_name = strdup(src->h_name); if (!dst->h_name) goto err_exit; } else dst->h_name = 0; if (src->h_aliases) { for (n = 0; ; ++n) { if (!src->h_aliases[n]) break; } dst->h_aliases = malloc((n + 1) * sizeof(char *)); if (!dst->h_aliases) goto err_exit; for (i = 0; i < n; ++i) { dst->h_aliases[i] = strdup(src->h_aliases[i]); if (!dst->h_aliases[i]) goto err_exit; } dst->h_aliases[n] = NULL; } else dst->h_aliases = NULL; dst->h_addrtype = src->h_addrtype; dst->h_length = src->h_length; if (src->h_addr_list) { for (n = 0; ; ++n) { if (!src->h_addr_list[n]) break; } dst->h_addr_list = malloc((n + 1) * sizeof(char *)); if (!dst->h_addr_list) goto err_exit; for (i = 0; i < n; ++i) { dst->h_addr_list[i] = malloc(src->h_length); if (!dst->h_addr_list[i]) goto err_exit; memcpy(dst->h_addr_list[i], src->h_addr_list[i], src->h_length); } dst->h_addr_list[n] = NULL; } else { dst->h_addr_list = NULL; } return CURLE_OK; err_exit: hostent_dup_free(dst); return CURLE_OUT_OF_MEMORY; } /* Destroy resolver thread synchronization data */ static void destroy_thread_sync_data(struct thread_sync_data * tsd) { if (tsd->mtx) { curl_mutex_destroy(tsd->mtx); free(tsd->mtx); } if(tsd->hostname) free(tsd->hostname); hostent_dup_free(&tsd->he); if (tsd->res) Curl_freeaddrinfo(tsd->res); memset(tsd,0,sizeof(*tsd)); } /* Initialize resolver thread synchronization data */ static BOOL init_thread_sync_data(struct thread_sync_data * tsd, const char * hostname, int port, const struct addrinfo *hints) { memset(tsd, 0, sizeof(*tsd)); tsd->port = port; #ifdef CURLRES_IPV6 DEBUGASSERT(hints); tsd->hints = *hints; #else (void) hints; #endif tsd->mtx = malloc(sizeof(curl_mutex_t)); if (tsd->mtx == NULL) goto err_exit; curl_mutex_init(tsd->mtx); tsd->sock_error = CURL_ASYNC_SUCCESS; /* Copying hostname string because original can be destroyed by parent * thread during gethostbyname execution. */ tsd->hostname = strdup(hostname); if (!tsd->hostname) goto err_exit; return TRUE; err_exit: /* Memory allocation failed */ destroy_thread_sync_data(tsd); return FALSE; } #if defined(CURLRES_IPV4) /* * gethostbyname_thread() resolves a name and then exits. * * For builds without ARES/ENABLE_IPV6, create a resolver thread and wait on * it. */ static unsigned int CURL_STDCALL gethostbyname_thread (void *arg) { struct thread_sync_data *tsd = (struct thread_sync_data *)arg; struct hostent *he = gethostbyname (tsd->hostname); if (!he) tsd->sock_error = SOCKERRNO; else tsd->rc = hostent_dup(&tsd->he, he); curl_mutex_acquire(tsd->mtx); tsd->done = 1; curl_mutex_release(tsd->mtx); return 0; } static void gethostbyname_complete(struct connectdata * conn) { struct thread_sync_data *tsd = conn_thread_sync_data(conn); if (tsd->rc != 0) return; tsd->rc = Curl_addrinfo4_callback(conn, tsd->sock_error, &tsd->he); } #elif defined(CURLRES_IPV6) /* * getaddrinfo_thread() resolves a name and then exits. * * For builds without ARES, but with ENABLE_IPV6, create a resolver thread * and wait on it. */ static unsigned int CURL_STDCALL getaddrinfo_thread (void *arg) { struct thread_sync_data *tsd = (struct thread_sync_data*)arg; char service [NI_MAXSERV]; snprintf(service, sizeof(service), "%d", tsd->port); tsd->rc = Curl_getaddrinfo_ex(tsd->hostname, service, &tsd->hints, &tsd->res); if (tsd->rc != 0) tsd->sock_error = SOCKERRNO; curl_mutex_acquire(tsd->mtx); tsd->done = 1; curl_mutex_release(tsd->mtx); return 0; } static void getaddrinfo_complete(struct connectdata *conn) { struct thread_sync_data *tsd = conn_thread_sync_data(conn); tsd->rc = Curl_addrinfo6_callback(conn, tsd->sock_error, tsd->res); /* The tsd->res structure has been copied to async.dns and perhaps the DNS cache. Set our copy to NULL so destroy_thread_sync_data doesn't free it. */ tsd->res = NULL; } #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; if (td->dummy_sock != CURL_SOCKET_BAD) sclose(td->dummy_sock); if (td->thread_hnd != curl_thread_t_null) curl_thread_join(&td->thread_hnd); destroy_thread_sync_data(&td->tsd); 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 struct addrinfo *hints) { struct thread_data *td = calloc(sizeof(*td), 1); int err = ENOMEM; conn->async.os_specific = (void*) td; if(!td) goto err_exit; conn->async.port = port; conn->async.done = FALSE; conn->async.status = 0; conn->async.dns = NULL; td->dummy_sock = CURL_SOCKET_BAD; td->thread_hnd = curl_thread_t_null; if (!init_thread_sync_data(&td->tsd, hostname, port, hints)) goto err_exit; Curl_safefree(conn->async.hostname); conn->async.hostname = strdup(hostname); if(!conn->async.hostname) goto err_exit; #ifdef _WIN32 /* This socket is only to keep Curl_resolv_fdset() and select() happy; * should never become signalled for read since it's unbound but * Windows needs at least 1 socket in select(). */ td->dummy_sock = socket(AF_INET, SOCK_DGRAM, 0); if (td->dummy_sock == CURL_SOCKET_BAD) goto err_exit; #endif td->thread_hnd = curl_thread_create(THREAD_FUNC, &td->tsd); if(!td->thread_hnd) { #ifndef _WIN32_WCE err = errno; #endif goto err_exit; } return TRUE; err_exit: Curl_destroy_thread_data(&conn->async); SET_ERRNO(err); return FALSE; } /* * 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; CURLcode rc; DEBUGASSERT(conn && td); /* wait for the thread to resolve the name */ if (curl_thread_join(&td->thread_hnd)) { COMPLETE_FUNC(conn); rc = td->tsd.rc; } else { /* Weird error happened */ rc = -1; } conn->async.done = TRUE; if(entry) *entry = conn->async.dns; if(!conn->async.dns) { /* a name was not resolved */ if (rc == CURLE_OUT_OF_MEMORY) { failf(data, "Could not resolve host: %s", curl_easy_strerror(rc)); } else if (rc == CURLE_OPERATION_TIMEDOUT) { failf(data, "Resolving host timed out: %s", conn->host.name); } else 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; } } 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) { struct SessionHandle *data = conn->data; struct thread_data *td = (struct thread_data*) conn->async.os_specific; int done = 0; *entry = NULL; if (!td) { DEBUGASSERT(td); return CURLE_COULDNT_RESOLVE_HOST; } curl_mutex_acquire(td->tsd.mtx); done = td->tsd.done; curl_mutex_release(td->tsd.mtx); if (done) { conn->async.done = TRUE; COMPLETE_FUNC(conn); Curl_destroy_thread_data(&conn->async); if(!conn->async.dns) { failf(data, "Could not resolve host: %s; %s", conn->host.name, Curl_strerror(conn, conn->async.status)); return CURLE_COULDNT_RESOLVE_HOST; } *entry = conn->async.dns; } else { /* poll for name lookup done with exponential backoff up to 250ms */ int elapsed; elapsed = Curl_tvdiff(Curl_tvnow(), data->progress.t_startsingle); if (elapsed < 0) { elapsed = 0; } if (td->poll_interval == 0) { /* Start at 1ms poll interval */ td->poll_interval = 1; } else if (elapsed >= td->interval_end) { /* Back-off exponentially if last interval expired */ td->poll_interval *= 2; } if (td->poll_interval > 250) td->poll_interval = 250; td->interval_end = elapsed + td->poll_interval; Curl_expire(conn->data, td->poll_interval); } 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 readable, even though this is just a dummy */ socks[0] = td->dummy_sock; return GETSOCK_READSOCK(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; struct in_addr in; *waitp = 0; /* don't wait, we act synchronously */ if(Curl_inet_pton(AF_INET, hostname, &in) > 0) /* This is a dotted IP address 123.123.123.123-style */ return Curl_ip2addr(AF_INET, &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, ERRNO)); h = gethostbyname(hostname); if(!h) { infof(data, "gethostbyname(2) failed for %s:%d; %s\n", hostname, port, Curl_strerror(conn, SOCKERRNO)); 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; Curl_addrinfo *res; int error; char sbuf[NI_MAXSERV]; int pf; struct SessionHandle *data = conn->data; *waitp = FALSE; /* default to synch response */ /* * Check if a 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; } if (pf != PF_INET) { /* see if we have an IPv6 stack */ curl_socket_t 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); } } 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 snprintf(sbuf, sizeof(sbuf), "%d", port); /* 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, ERRNO)); error = Curl_getaddrinfo_ex(hostname, sbuf, &hints, &res); if(error) { infof(data, "getaddrinfo() failed for %s:%d; %s\n", hostname, port, Curl_strerror(conn, SOCKERRNO)); return NULL; } return res; } #endif /* CURLRES_IPV6 */ #endif /* CURLRES_THREADED */