/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) 1998 - 2016, 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 https://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. * ***************************************************************************/ #include "curl_setup.h" #ifdef HAVE_NETINET_IN_H #include #endif #ifdef HAVE_NETDB_H #include #endif #ifdef HAVE_ARPA_INET_H #include #endif #ifdef __VMS #include #include #endif #if defined(USE_THREADS_POSIX) # ifdef HAVE_PTHREAD_H # include # endif #elif defined(USE_THREADS_WIN32) # ifdef HAVE_PROCESS_H # include # endif #endif #if (defined(NETWARE) && defined(__NOVELL_LIBC__)) #undef in_addr_t #define in_addr_t unsigned long #endif #ifdef HAVE_GETADDRINFO # define RESOLVER_ENOMEM EAI_MEMORY #else # define RESOLVER_ENOMEM ENOMEM #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" #include "inet_ntop.h" #include "curl_threads.h" #include "connect.h" /* The last 3 #include files should be in this order */ #include "curl_printf.h" #include "curl_memory.h" #include "memdebug.h" /*********************************************************************** * Only for threaded name resolves builds **********************************************************************/ #ifdef CURLRES_THREADED /* * Curl_resolver_global_init() * Called from curl_global_init() to initialize global resolver environment. * Does nothing here. */ int Curl_resolver_global_init(void) { return CURLE_OK; } /* * Curl_resolver_global_cleanup() * Called from curl_global_cleanup() to destroy global resolver environment. * Does nothing here. */ void Curl_resolver_global_cleanup(void) { } /* * Curl_resolver_init() * Called from curl_easy_init() -> Curl_open() to initialize resolver * URL-state specific environment ('resolver' member of the UrlState * structure). Does nothing here. */ CURLcode Curl_resolver_init(void **resolver) { (void)resolver; return CURLE_OK; } /* * Curl_resolver_cleanup() * Called from curl_easy_cleanup() -> Curl_close() to cleanup resolver * URL-state specific environment ('resolver' member of the UrlState * structure). Does nothing here. */ void Curl_resolver_cleanup(void *resolver) { (void)resolver; } /* * Curl_resolver_duphandle() * Called from curl_easy_duphandle() to duplicate resolver URL state-specific * environment ('resolver' member of the UrlState structure). Does nothing * here. */ int Curl_resolver_duphandle(void **to, void *from) { (void)to; (void)from; return CURLE_OK; } static void destroy_async_data(struct Curl_async *); /* * Cancel all possibly still on-going resolves for this connection. */ void Curl_resolver_cancel(struct connectdata *conn) { destroy_async_data(&conn->async); } /* 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); /* 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; Curl_addrinfo *res; #ifdef HAVE_GETADDRINFO struct addrinfo hints; #endif struct thread_data *td; /* for thread-self cleanup */ }; struct thread_data { curl_thread_t thread_hnd; unsigned int poll_interval; long 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); /* 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); } free(tsd->hostname); if(tsd->res) Curl_freeaddrinfo(tsd->res); memset(tsd, 0, sizeof(*tsd)); } /* Initialize resolver thread synchronization data */ static int init_thread_sync_data(struct thread_data * td, const char * hostname, int port, const struct addrinfo *hints) { struct thread_sync_data *tsd = &td->tsd; memset(tsd, 0, sizeof(*tsd)); tsd->td = td; tsd->port = port; #ifdef HAVE_GETADDRINFO 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 1; err_exit: /* Memory allocation failed */ destroy_thread_sync_data(tsd); return 0; } static int getaddrinfo_complete(struct connectdata *conn) { struct thread_sync_data *tsd = conn_thread_sync_data(conn); int rc; rc = Curl_addrinfo_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; return rc; } #ifdef HAVE_GETADDRINFO /* * 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; struct thread_data *td = tsd->td; char service[12]; int rc; snprintf(service, sizeof(service), "%d", tsd->port); rc = Curl_getaddrinfo_ex(tsd->hostname, service, &tsd->hints, &tsd->res); if(rc != 0) { tsd->sock_error = SOCKERRNO?SOCKERRNO:rc; if(tsd->sock_error == 0) tsd->sock_error = RESOLVER_ENOMEM; } else { Curl_addrinfo_set_port(tsd->res, tsd->port); } Curl_mutex_acquire(tsd->mtx); if(tsd->done) { /* too late, gotta clean up the mess */ Curl_mutex_release(tsd->mtx); destroy_thread_sync_data(tsd); free(td); } else { tsd->done = 1; Curl_mutex_release(tsd->mtx); } return 0; } #else /* HAVE_GETADDRINFO */ /* * gethostbyname_thread() resolves a name and then exits. */ static unsigned int CURL_STDCALL gethostbyname_thread (void *arg) { struct thread_sync_data *tsd = (struct thread_sync_data *)arg; struct thread_data *td = tsd->td; tsd->res = Curl_ipv4_resolve_r(tsd->hostname, tsd->port); if(!tsd->res) { tsd->sock_error = SOCKERRNO; if(tsd->sock_error == 0) tsd->sock_error = RESOLVER_ENOMEM; } Curl_mutex_acquire(tsd->mtx); if(tsd->done) { /* too late, gotta clean up the mess */ Curl_mutex_release(tsd->mtx); destroy_thread_sync_data(tsd); free(td); } else { tsd->done = 1; Curl_mutex_release(tsd->mtx); } return 0; } #endif /* HAVE_GETADDRINFO */ /* * destroy_async_data() cleans up async resolver data and thread handle. */ static void destroy_async_data (struct Curl_async *async) { if(async->os_specific) { struct thread_data *td = (struct thread_data*) async->os_specific; int done; /* * if the thread is still blocking in the resolve syscall, detach it and * let the thread do the cleanup... */ Curl_mutex_acquire(td->tsd.mtx); done = td->tsd.done; td->tsd.done = 1; Curl_mutex_release(td->tsd.mtx); if(!done) { Curl_thread_destroy(td->thread_hnd); } else { 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->os_specific = NULL; free(async->hostname); async->hostname = 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(1, sizeof(struct thread_data)); int err = RESOLVER_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->thread_hnd = curl_thread_t_null; if(!init_thread_sync_data(td, hostname, port, hints)) goto err_exit; free(conn->async.hostname); conn->async.hostname = strdup(hostname); if(!conn->async.hostname) goto err_exit; #ifdef HAVE_GETADDRINFO td->thread_hnd = Curl_thread_create(getaddrinfo_thread, &td->tsd); #else td->thread_hnd = Curl_thread_create(gethostbyname_thread, &td->tsd); #endif if(!td->thread_hnd) { #ifndef _WIN32_WCE err = errno; #endif goto err_exit; } return TRUE; err_exit: destroy_async_data(&conn->async); SET_ERRNO(err); return FALSE; } /* * resolver_error() calls failf() with the appropriate message after a resolve * error */ static CURLcode resolver_error(struct connectdata *conn) { const char *host_or_proxy; CURLcode result; if(conn->bits.httpproxy) { host_or_proxy = "proxy"; result = CURLE_COULDNT_RESOLVE_PROXY; } else { host_or_proxy = "host"; result = CURLE_COULDNT_RESOLVE_HOST; } failf(conn->data, "Could not resolve %s: %s", host_or_proxy, conn->async.hostname); return result; } /* * Curl_resolver_wait_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_resolver_wait_resolv(struct connectdata *conn, struct Curl_dns_entry **entry) { struct thread_data *td = (struct thread_data*) conn->async.os_specific; CURLcode result = CURLE_OK; DEBUGASSERT(conn && td); /* wait for the thread to resolve the name */ if(Curl_thread_join(&td->thread_hnd)) result = getaddrinfo_complete(conn); else DEBUGASSERT(0); conn->async.done = TRUE; if(entry) *entry = conn->async.dns; if(!conn->async.dns) /* a name was not resolved, report error */ result = resolver_error(conn); destroy_async_data(&conn->async); if(!conn->async.dns) connclose(conn, "asynch resolve failed"); return result; } /* * Curl_resolver_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_resolver_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) { getaddrinfo_complete(conn); if(!conn->async.dns) { CURLcode result = resolver_error(conn); destroy_async_data(&conn->async); return result; } destroy_async_data(&conn->async); *entry = conn->async.dns; } else { /* poll for name lookup done with exponential backoff up to 250ms */ long 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_resolver_getsock(struct connectdata *conn, curl_socket_t *socks, int numsocks) { (void)conn; (void)socks; (void)numsocks; return 0; } #ifndef HAVE_GETADDRINFO /* * Curl_getaddrinfo() - for platforms without getaddrinfo */ Curl_addrinfo *Curl_resolver_getaddrinfo(struct connectdata *conn, const char *hostname, int port, int *waitp) { struct in_addr in; *waitp = 0; /* default to synchronous response */ 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 = 1; /* expect asynchronous response */ return NULL; } /* fall-back to blocking version */ return Curl_ipv4_resolve_r(hostname, port); } #else /* !HAVE_GETADDRINFO */ /* * Curl_resolver_getaddrinfo() - for getaddrinfo */ Curl_addrinfo *Curl_resolver_getaddrinfo(struct connectdata *conn, const char *hostname, int port, int *waitp) { struct addrinfo hints; struct in_addr in; Curl_addrinfo *res; int error; char sbuf[12]; int pf = PF_INET; #ifdef CURLRES_IPV6 struct in6_addr in6; #endif /* CURLRES_IPV6 */ *waitp = 0; /* default to synchronous response */ #ifndef USE_RESOLVE_ON_IPS /* First check if this is an IPv4 address string */ 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); #ifdef CURLRES_IPV6 /* check if this is an IPv6 address string */ if(Curl_inet_pton(AF_INET6, hostname, &in6) > 0) /* This is an IPv6 address literal */ return Curl_ip2addr(AF_INET6, &in6, hostname, port); /* * Check if a limited name resolve has been requested. */ switch(conn->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) && !Curl_ipv6works()) /* The stack seems to be a non-IPv6 one */ pf = PF_INET; #endif /* CURLRES_IPV6 */ #endif /* USE_RESOLVE_ON_IPS */ memset(&hints, 0, sizeof(hints)); hints.ai_family = pf; hints.ai_socktype = conn->socktype; snprintf(sbuf, sizeof(sbuf), "%d", port); /* fire up a new resolver thread! */ if(init_resolve_thread(conn, hostname, port, &hints)) { *waitp = 1; /* expect asynchronous response */ return NULL; } /* fall-back to blocking version */ infof(conn->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(conn->data, "getaddrinfo() failed for %s:%d; %s\n", hostname, port, Curl_strerror(conn, SOCKERRNO)); return NULL; } else { Curl_addrinfo_set_port(res, port); } return res; } #endif /* !HAVE_GETADDRINFO */ CURLcode Curl_set_dns_servers(struct SessionHandle *data, char *servers) { (void)data; (void)servers; return CURLE_NOT_BUILT_IN; } CURLcode Curl_set_dns_interface(struct SessionHandle *data, const char *interf) { (void)data; (void)interf; return CURLE_NOT_BUILT_IN; } CURLcode Curl_set_dns_local_ip4(struct SessionHandle *data, const char *local_ip4) { (void)data; (void)local_ip4; return CURLE_NOT_BUILT_IN; } CURLcode Curl_set_dns_local_ip6(struct SessionHandle *data, const char *local_ip6) { (void)data; (void)local_ip6; return CURLE_NOT_BUILT_IN; } #endif /* CURLRES_THREADED */