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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2011, 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.
*
***************************************************************************/
#include "setup.h"
#include <string.h>
#include <errno.h>
#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
#if defined(USE_THREADS_POSIX)
# ifdef HAVE_PTHREAD_H
# include <pthread.h>
# endif
#elif defined(USE_THREADS_WIN32)
# ifdef HAVE_PROCESS_H
# include <process.h>
# 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"
#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>
#include "curl_memory.h"
/* The last #include file should be: */
#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 {
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);
/* 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);
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_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 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;
char service [NI_MAXSERV];
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;
}
Curl_mutex_acquire(tsd->mtx);
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;
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);
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->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(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->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_resolver_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
#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;
}
#if defined(HAVE_GETADDRINFO) && !defined(HAVE_GAI_STRERROR) && !defined(WIN32)
/* NetWare has getaddrinfo but lacks gai_strerror.
Windows has a gai_strerror but it is bad (not thread-safe) and the generic
socket error string function can be used for this pupose. */
static const char *gai_strerror(int ecode)
{
switch (ecode){
case EAI_AGAIN:
return "The name could not be resolved at this time";
case EAI_BADFLAGS:
return "The flags parameter had an invalid value";
case EAI_FAIL:
return "A non-recoverable error occurred when attempting to "
"resolve the name";
case EAI_FAMILY:
return "The address family was not recognized";
case EAI_MEMORY:
return "Out of memory";
case EAI_NONAME:
return "The name does not resolve for the supplied parameters";
case EAI_SERVICE:
return "The service passed was not recognized for the "
"specified socket type"
case EAI_SOCKTYPE:
return "The intended socket type was not recognized"
case EAI_SYSTEM:
return "A system error occurred";
case EAI_OVERFLOW:
return "An argument buffer overflowed";
default:
return "Unknown error";
/* define this now as this is a private implementation of said function */
#define HAVE_GAI_STRERROR
}
#endif
/*
* resolver_error() calls failf() with the appropriate message after a resolve
* error
*/
static void resolver_error(struct connectdata *conn, const char *host_or_proxy)
{
failf(conn->data, "Could not resolve %s: %s; %s", host_or_proxy,
conn->async.hostname,
#ifdef HAVE_GAI_STRERROR
/* NetWare doesn't have gai_strerror and on Windows it isn't deemed
thread-safe */
gai_strerror(conn->async.status)
#else
Curl_strerror(conn, conn->async.status)
#endif
);
}
/*
* 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 rc = CURLE_OK;
DEBUGASSERT(conn && td);
/* wait for the thread to resolve the name */
if(Curl_thread_join(&td->thread_hnd))
rc = 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 */
if(conn->bits.httpproxy) {
resolver_error(conn, "proxy");
rc = CURLE_COULDNT_RESOLVE_PROXY;
}
else {
resolver_error(conn, "host");
rc = CURLE_COULDNT_RESOLVE_HOST;
}
}
destroy_async_data(&conn->async);
if(!conn->async.dns)
conn->bits.close = TRUE;
return (rc);
}
/*
* 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);
destroy_async_data(&conn->async);
if(!conn->async.dns) {
resolver_error(conn, "host");
return CURLE_COULDNT_RESOLVE_HOST;
}
*entry = conn->async.dns;
}
else {
/* poll for name lookup done with exponential backoff up to 250ms */
int 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)
{
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;
}
#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;
Curl_addrinfo *res;
int error;
char sbuf[NI_MAXSERV];
int pf = PF_INET;
*waitp = 0; /* default to synchronous response */
#ifndef CURLRES_IPV4
/*
* 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_IPV4 */
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;
}
return res;
}
#endif /* !HAVE_GETADDRINFO */
#endif /* CURLRES_THREADED */
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