4 * - TCP connection management
5 * - user-visible check/wait and event-loop-related functions
8 * This file is part of adns, which is
9 * Copyright (C) 1997-2000,2003,2006,2014-2016 Ian Jackson
10 * Copyright (C) 2014 Mark Wooding
11 * Copyright (C) 1999-2000,2003,2006 Tony Finch
12 * Copyright (C) 1991 Massachusetts Institute of Technology
13 * (See the file INSTALL for full details.)
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License as published by
17 * the Free Software Foundation; either version 3, or (at your option)
20 * This program is distributed in the hope that it will be useful,
21 * but WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23 * GNU General Public License for more details.
25 * You should have received a copy of the GNU General Public License
26 * along with this program; if not, write to the Free Software Foundation.
33 #include <sys/types.h>
36 #include <sys/socket.h>
37 #include <netinet/in.h>
38 #include <arpa/inet.h>
43 /* TCP connection management. */
45 static void tcp_close(adns_state ads
) {
46 close(ads
->tcpsocket
);
48 ads
->tcprecv
.used
= ads
->tcprecv_skip
= ads
->tcpsend
.used
= 0;
51 void adns__tcp_broken(adns_state ads
, const char *what
, const char *why
) {
55 assert(ads
->tcpstate
== server_connecting
|| ads
->tcpstate
== server_ok
);
57 if (what
) adns__warn(ads
,serv
,0,"TCP connection failed: %s: %s",what
,why
);
59 if (ads
->tcpstate
== server_connecting
) {
60 /* Counts as a retry for all the queries waiting for TCP. */
61 for (qu
= ads
->tcpw
.head
; qu
; qu
= qu
->next
)
66 ads
->tcpstate
= server_broken
;
67 ads
->tcpserver
= (serv
+1)%ads
->nservers
;
70 static void tcp_connected(adns_state ads
, struct timeval now
) {
73 adns__debug(ads
,ads
->tcpserver
,0,"TCP connected");
74 ads
->tcpstate
= server_ok
;
75 for (qu
= ads
->tcpw
.head
; qu
&& ads
->tcpstate
== server_ok
; qu
= nqu
) {
77 assert(qu
->state
== query_tcpw
);
78 adns__querysend_tcp(qu
,now
);
82 static void tcp_broken_events(adns_state ads
) {
85 assert(ads
->tcpstate
== server_broken
);
86 for (qu
= ads
->tcpw
.head
; qu
; qu
= nqu
) {
88 assert(qu
->state
== query_tcpw
);
89 if (qu
->retries
> ads
->nservers
) {
90 LIST_UNLINK(ads
->tcpw
,qu
);
91 adns__query_fail(qu
,adns_s_allservfail
);
94 ads
->tcpstate
= server_disconnected
;
97 void adns__tcp_tryconnect(adns_state ads
, struct timeval now
) {
100 struct protoent
*proto
;
102 for (tries
=0; tries
<ads
->nservers
; tries
++) {
103 switch (ads
->tcpstate
) {
104 case server_connecting
:
108 case server_disconnected
:
114 assert(!ads
->tcpsend
.used
);
115 assert(!ads
->tcprecv
.used
);
116 assert(!ads
->tcprecv_skip
);
118 proto
= getprotobyname("tcp");
120 adns__diag(ads
,-1,0,"unable to find protocol no. for TCP !");
123 addr
= &ads
->servers
[ads
->tcpserver
];
124 fd
= socket(addr
->addr
.sa
.sa_family
, SOCK_STREAM
, proto
->p_proto
);
126 adns__diag(ads
,-1,0,"cannot create TCP socket: %s",strerror(errno
));
129 r
= adns__setnonblock(ads
,fd
);
131 adns__diag(ads
,-1,0,"cannot make TCP socket nonblocking:"
136 r
= connect(fd
,&addr
->addr
.sa
,addr
->len
);
138 ads
->tcpstate
= server_connecting
;
139 if (r
==0) { tcp_connected(ads
,now
); return; }
140 if (errno
== EWOULDBLOCK
|| errno
== EINPROGRESS
) {
141 ads
->tcptimeout
= now
;
142 timevaladd(&ads
->tcptimeout
,TCPCONNMS
);
145 adns__tcp_broken(ads
,"connect",strerror(errno
));
146 tcp_broken_events(ads
);
150 /* Timeout handling functions. */
152 void adns__must_gettimeofday(adns_state ads
, const struct timeval
**now_io
,
153 struct timeval
*tv_buf
) {
154 const struct timeval
*now
;
159 r
= gettimeofday(tv_buf
,0); if (!r
) { *now_io
= tv_buf
; return; }
160 adns__diag(ads
,-1,0,"gettimeofday failed: %s",strerror(errno
));
161 adns_globalsystemfailure(ads
);
165 static void inter_immed(struct timeval
**tv_io
, struct timeval
*tvbuf
) {
166 struct timeval
*rbuf
;
171 if (!rbuf
) { *tv_io
= rbuf
= tvbuf
; }
176 static void inter_maxto(struct timeval
**tv_io
, struct timeval
*tvbuf
,
177 struct timeval maxto
) {
178 struct timeval
*rbuf
;
183 *tvbuf
= maxto
; *tv_io
= tvbuf
;
185 if (timercmp(rbuf
,&maxto
,>)) *rbuf
= maxto
;
187 /*fprintf(stderr,"inter_maxto maxto=%ld.%06ld result=%ld.%06ld\n",
188 maxto.tv_sec,maxto.tv_usec,(**tv_io).tv_sec,(**tv_io).tv_usec);*/
191 static void inter_maxtoabs(struct timeval
**tv_io
, struct timeval
*tvbuf
,
192 struct timeval now
, struct timeval maxtime
) {
196 /*fprintf(stderr,"inter_maxtoabs now=%ld.%06ld maxtime=%ld.%06ld\n",
197 now.tv_sec,now.tv_usec,maxtime.tv_sec,maxtime.tv_usec);*/
199 maxtime
.tv_sec
-= (now
.tv_sec
+2);
200 maxtime
.tv_usec
-= (now
.tv_usec
-2000000);
201 dr
= ldiv(maxtime
.tv_usec
,1000000);
202 maxtime
.tv_sec
+= dr
.quot
;
203 maxtime
.tv_usec
-= dr
.quot
*1000000;
204 if (maxtime
.tv_sec
<0) timerclear(&maxtime
);
205 inter_maxto(tv_io
,tvbuf
,maxtime
);
208 static void timeouts_queue(adns_state ads
, int act
,
209 struct timeval
**tv_io
, struct timeval
*tvbuf
,
210 struct timeval now
, struct query_queue
*queue
) {
213 for (qu
= queue
->head
; qu
; qu
= nqu
) {
215 if (!timercmp(&now
,&qu
->timeout
,>)) {
216 inter_maxtoabs(tv_io
,tvbuf
,now
,qu
->timeout
);
218 if (!act
) { inter_immed(tv_io
,tvbuf
); return; }
219 LIST_UNLINK(*queue
,qu
);
220 if (qu
->state
!= query_tosend
) {
221 adns__query_fail(qu
,adns_s_timeout
);
223 adns__query_send(qu
,now
);
230 static void tcp_events(adns_state ads
, int act
,
231 struct timeval
**tv_io
, struct timeval
*tvbuf
,
232 struct timeval now
) {
234 switch (ads
->tcpstate
) {
236 if (!act
) { inter_immed(tv_io
,tvbuf
); return; }
237 tcp_broken_events(ads
);
238 case server_disconnected
: /* fall through */
239 if (!ads
->tcpw
.head
) return;
240 if (!act
) { inter_immed(tv_io
,tvbuf
); return; }
241 adns__tcp_tryconnect(ads
,now
);
244 if (ads
->tcpw
.head
) return;
245 if (!ads
->tcptimeout
.tv_sec
) {
246 assert(!ads
->tcptimeout
.tv_usec
);
247 ads
->tcptimeout
= now
;
248 timevaladd(&ads
->tcptimeout
,TCPIDLEMS
);
250 case server_connecting
: /* fall through */
251 if (!act
|| !timercmp(&now
,&ads
->tcptimeout
,>)) {
252 inter_maxtoabs(tv_io
,tvbuf
,now
,ads
->tcptimeout
);
255 /* TCP timeout has happened */
256 switch (ads
->tcpstate
) {
257 case server_connecting
: /* failed to connect */
258 adns__tcp_broken(ads
,"unable to make connection","timed out");
260 case server_ok
: /* idle timeout */
262 ads
->tcpstate
= server_disconnected
;
276 void adns__timeouts(adns_state ads
, int act
,
277 struct timeval
**tv_io
, struct timeval
*tvbuf
,
278 struct timeval now
) {
279 timeouts_queue(ads
,act
,tv_io
,tvbuf
,now
, &ads
->udpw
);
280 timeouts_queue(ads
,act
,tv_io
,tvbuf
,now
, &ads
->tcpw
);
281 tcp_events(ads
,act
,tv_io
,tvbuf
,now
);
284 void adns_firsttimeout(adns_state ads
,
285 struct timeval
**tv_io
, struct timeval
*tvbuf
,
286 struct timeval now
) {
287 adns__consistency(ads
,0,cc_entex
);
288 adns__timeouts(ads
, 0, tv_io
,tvbuf
, now
);
289 adns__returning(ads
,0);
292 void adns_processtimeouts(adns_state ads
, const struct timeval
*now
) {
293 struct timeval tv_buf
;
295 adns__consistency(ads
,0,cc_entex
);
296 adns__must_gettimeofday(ads
,&now
,&tv_buf
);
297 if (now
) adns__timeouts(ads
, 1, 0,0, *now
);
298 adns__returning(ads
,0);
301 /* fd handling functions. These are the top-level of the real work of
302 * reception and often transmission.
305 int adns__pollfds(adns_state ads
, struct pollfd pollfds_buf
[MAX_POLLFDS
]) {
306 /* Returns the number of entries filled in. Always zeroes revents. */
308 #define ADD_POLLFD(wantfd, wantevents) do{ \
309 pollfds_buf[nwanted].fd= (wantfd); \
310 pollfds_buf[nwanted].events= (wantevents); \
311 pollfds_buf[nwanted].revents= 0; \
317 assert(MAX_POLLFDS
== MAXUDP
+ 1);
319 for (i
=0; i
<ads
->nudpsockets
; i
++)
320 ADD_POLLFD(ads
->udpsockets
[i
].fd
, POLLIN
);
322 switch (ads
->tcpstate
) {
323 case server_disconnected
:
326 case server_connecting
:
327 ADD_POLLFD(ads
->tcpsocket
, POLLOUT
);
330 ADD_POLLFD(ads
->tcpsocket
,
331 ads
->tcpsend
.used ? POLLIN
|POLLOUT
|POLLPRI
: POLLIN
|POLLPRI
);
336 assert(nwanted
<=MAX_POLLFDS
);
341 int adns_processreadable(adns_state ads
, int fd
, const struct timeval
*now
) {
342 int want
, dgramlen
, r
, i
, serv
, old_skip
;
343 socklen_t udpaddrlen
;
344 byte udpbuf
[DNS_MAXUDP
];
345 char addrbuf
[ADNS_ADDR2TEXT_BUFLEN
];
346 struct udpsocket
*udp
;
347 adns_sockaddr udpaddr
;
349 adns__consistency(ads
,0,cc_entex
);
351 switch (ads
->tcpstate
) {
352 case server_disconnected
:
354 case server_connecting
:
357 if (fd
!= ads
->tcpsocket
) break;
358 assert(!ads
->tcprecv_skip
);
360 if (ads
->tcprecv
.used
>= ads
->tcprecv_skip
+2) {
361 dgramlen
= ((ads
->tcprecv
.buf
[ads
->tcprecv_skip
]<<8) |
362 ads
->tcprecv
.buf
[ads
->tcprecv_skip
+1]);
363 if (ads
->tcprecv
.used
>= ads
->tcprecv_skip
+2+dgramlen
) {
364 old_skip
= ads
->tcprecv_skip
;
365 ads
->tcprecv_skip
+= 2+dgramlen
;
366 adns__procdgram(ads
, ads
->tcprecv
.buf
+old_skip
+2,
367 dgramlen
, ads
->tcpserver
, 1,*now
);
375 ads
->tcprecv
.used
-= ads
->tcprecv_skip
;
376 memmove(ads
->tcprecv
.buf
, ads
->tcprecv
.buf
+ads
->tcprecv_skip
,
378 ads
->tcprecv_skip
= 0;
379 if (!adns__vbuf_ensure(&ads
->tcprecv
,want
)) { r
= ENOMEM
; goto xit
; }
380 assert(ads
->tcprecv
.used
<= ads
->tcprecv
.avail
);
381 if (ads
->tcprecv
.used
== ads
->tcprecv
.avail
) continue;
382 r
= read(ads
->tcpsocket
,
383 ads
->tcprecv
.buf
+ads
->tcprecv
.used
,
384 ads
->tcprecv
.avail
-ads
->tcprecv
.used
);
386 ads
->tcprecv
.used
+= r
;
389 if (errno
==EAGAIN
|| errno
==EWOULDBLOCK
) { r
= 0; goto xit
; }
390 if (errno
==EINTR
) continue;
391 if (errno_resources(errno
)) { r
= errno
; goto xit
; }
393 adns__tcp_broken(ads
,"read",r?
strerror(errno
):"closed");
395 } while (ads
->tcpstate
== server_ok
);
400 for (i
=0; i
<ads
->nudpsockets
; i
++) {
401 udp
= &ads
->udpsockets
[i
];
402 if (fd
!= udp
->fd
) continue;
404 udpaddrlen
= sizeof(udpaddr
);
405 r
= recvfrom(fd
,udpbuf
,sizeof(udpbuf
),0, &udpaddr
.sa
,&udpaddrlen
);
407 if (errno
== EAGAIN
|| errno
== EWOULDBLOCK
) { r
= 0; goto xit
; }
408 if (errno
== EINTR
) continue;
409 if (errno_resources(errno
)) { r
= errno
; goto xit
; }
410 adns__warn(ads
,-1,0,"datagram receive error: %s",strerror(errno
));
414 serv
< ads
->nservers
&&
415 !adns__sockaddrs_equal(&udpaddr
.sa
,
416 &ads
->servers
[serv
].addr
.sa
);
418 if (serv
>= ads
->nservers
) {
419 adns__warn(ads
,-1,0,"datagram received from unknown nameserver %s",
420 adns__sockaddr_ntoa(&udpaddr
.sa
, addrbuf
));
423 adns__procdgram(ads
,udpbuf
,r
,serv
,0,*now
);
429 adns__returning(ads
,0);
433 int adns_processwriteable(adns_state ads
, int fd
, const struct timeval
*now
) {
436 adns__consistency(ads
,0,cc_entex
);
438 switch (ads
->tcpstate
) {
439 case server_disconnected
:
442 case server_connecting
:
443 if (fd
!= ads
->tcpsocket
) break;
444 assert(ads
->tcprecv
.used
==0);
445 assert(ads
->tcprecv_skip
==0);
447 /* This function can be called even if the fd wasn't actually
448 * flagged as writeable. For asynch tcp connect we have to
449 * actually use the writeability to tell us the connect has
450 * completed (or failed), so we need to double check. */
452 struct timeval timeout
= { 0,0 };
454 FD_SET(ads
->tcpsocket
,&writeable
);
455 r
= select(ads
->tcpsocket
+1,0,&writeable
,0,&timeout
);
458 if (errno
==EINTR
) continue;
459 adns__tcp_broken(ads
,"select","failed connecting writeability check");
462 assert(FD_ISSET(ads
->tcpsocket
,&writeable
));
463 if (!adns__vbuf_ensure(&ads
->tcprecv
,1)) { r
= ENOMEM
; goto xit
; }
464 r
= read(ads
->tcpsocket
,&ads
->tcprecv
.buf
,1);
465 if (r
==0 || (r
<0 && (errno
==EAGAIN
|| errno
==EWOULDBLOCK
))) {
466 tcp_connected(ads
,*now
);
470 adns__tcp_broken(ads
,"connect/read","sent data before first request");
473 if (errno
==EINTR
) continue;
474 if (errno_resources(errno
)) { r
= errno
; goto xit
; }
475 adns__tcp_broken(ads
,"connect/read",strerror(errno
));
479 if (fd
!= ads
->tcpsocket
) break;
480 while (ads
->tcpsend
.used
) {
481 adns__sigpipe_protect(ads
);
482 r
= write(ads
->tcpsocket
,ads
->tcpsend
.buf
,ads
->tcpsend
.used
);
483 adns__sigpipe_unprotect(ads
);
485 if (errno
==EINTR
) continue;
486 if (errno
==EAGAIN
|| errno
==EWOULDBLOCK
) { r
= 0; goto xit
; }
487 if (errno_resources(errno
)) { r
= errno
; goto xit
; }
488 adns__tcp_broken(ads
,"write",strerror(errno
));
491 ads
->tcpsend
.used
-= r
;
492 memmove(ads
->tcpsend
.buf
,ads
->tcpsend
.buf
+r
,ads
->tcpsend
.used
);
502 adns__returning(ads
,0);
506 int adns_processexceptional(adns_state ads
, int fd
,
507 const struct timeval
*now
) {
508 adns__consistency(ads
,0,cc_entex
);
509 switch (ads
->tcpstate
) {
510 case server_disconnected
:
513 case server_connecting
:
515 if (fd
!= ads
->tcpsocket
) break;
516 adns__tcp_broken(ads
,"poll/select","exceptional condition detected");
521 adns__returning(ads
,0);
525 static void fd_event(adns_state ads
, int fd
,
526 int revent
, int pollflag
,
527 int maxfd
, const fd_set
*fds
,
528 int (*func
)(adns_state
, int fd
,
529 const struct timeval
*now
),
530 struct timeval now
, int *r_r
) {
533 if (!(revent
& pollflag
)) return;
534 if (fds
&& !(fd
<maxfd
&& FD_ISSET(fd
,fds
))) return;
535 r
= func(ads
,fd
,&now
);
540 adns__diag(ads
,-1,0,"process fd failed after select:"
541 " %s",strerror(errno
));
542 adns_globalsystemfailure(ads
);
547 void adns__fdevents(adns_state ads
,
548 const struct pollfd
*pollfds
, int npollfds
,
549 int maxfd
, const fd_set
*readfds
,
550 const fd_set
*writefds
, const fd_set
*exceptfds
,
551 struct timeval now
, int *r_r
) {
554 for (i
=0; i
<npollfds
; i
++) {
556 if (fd
>= maxfd
) maxfd
= fd
+1;
557 revents
= pollfds
[i
].revents
;
558 #define EV(pollfl,fds,how) \
559 fd_event(ads,fd, revents,pollfl, maxfd,fds, adns_process##how,now,r_r)
560 EV( POLLIN
, readfds
, readable
);
561 EV( POLLOUT
, writefds
, writeable
);
562 EV( POLLPRI
, exceptfds
, exceptional
);
567 /* Wrappers for select(2). */
569 void adns_beforeselect(adns_state ads
, int *maxfd_io
, fd_set
*readfds_io
,
570 fd_set
*writefds_io
, fd_set
*exceptfds_io
,
571 struct timeval
**tv_mod
, struct timeval
*tv_tobuf
,
572 const struct timeval
*now
) {
573 struct timeval tv_nowbuf
;
574 struct pollfd pollfds
[MAX_POLLFDS
];
575 int i
, fd
, maxfd
, npollfds
;
577 adns__consistency(ads
,0,cc_entex
);
579 if (tv_mod
&& (!*tv_mod
|| (*tv_mod
)->tv_sec
|| (*tv_mod
)->tv_usec
)) {
580 /* The caller is planning to sleep. */
581 adns__must_gettimeofday(ads
,&now
,&tv_nowbuf
);
582 if (!now
) { inter_immed(tv_mod
,tv_tobuf
); goto xit
; }
583 adns__timeouts(ads
, 0, tv_mod
,tv_tobuf
, *now
);
586 npollfds
= adns__pollfds(ads
,pollfds
);
588 for (i
=0; i
<npollfds
; i
++) {
590 if (fd
>= maxfd
) maxfd
= fd
+1;
591 if (pollfds
[i
].events
& POLLIN
) FD_SET(fd
,readfds_io
);
592 if (pollfds
[i
].events
& POLLOUT
) FD_SET(fd
,writefds_io
);
593 if (pollfds
[i
].events
& POLLPRI
) FD_SET(fd
,exceptfds_io
);
598 adns__returning(ads
,0);
601 void adns_afterselect(adns_state ads
, int maxfd
, const fd_set
*readfds
,
602 const fd_set
*writefds
, const fd_set
*exceptfds
,
603 const struct timeval
*now
) {
604 struct timeval tv_buf
;
605 struct pollfd pollfds
[MAX_POLLFDS
];
608 adns__consistency(ads
,0,cc_entex
);
609 adns__must_gettimeofday(ads
,&now
,&tv_buf
);
611 adns_processtimeouts(ads
,now
);
613 npollfds
= adns__pollfds(ads
,pollfds
);
614 for (i
=0; i
<npollfds
; i
++) pollfds
[i
].revents
= POLLIN
|POLLOUT
|POLLPRI
;
617 maxfd
,readfds
,writefds
,exceptfds
,
620 adns__returning(ads
,0);
623 /* General helpful functions. */
625 void adns_globalsystemfailure(adns_state ads
) {
626 adns__consistency(ads
,0,cc_entex
);
628 while (ads
->udpw
.head
) adns__query_fail(ads
->udpw
.head
, adns_s_systemfail
);
629 while (ads
->tcpw
.head
) adns__query_fail(ads
->tcpw
.head
, adns_s_systemfail
);
631 switch (ads
->tcpstate
) {
632 case server_connecting
:
634 adns__tcp_broken(ads
,0,0);
636 case server_disconnected
:
642 adns__returning(ads
,0);
645 int adns_processany(adns_state ads
) {
648 struct pollfd pollfds
[MAX_POLLFDS
];
651 adns__consistency(ads
,0,cc_entex
);
653 r
= gettimeofday(&now
,0);
654 if (!r
) adns_processtimeouts(ads
,&now
);
656 /* We just use adns__fdevents to loop over the fd's trying them.
657 * This seems more sensible than calling select, since we're most
658 * likely just to want to do a read on one or two fds anyway.
660 npollfds
= adns__pollfds(ads
,pollfds
);
661 for (i
=0; i
<npollfds
; i
++) pollfds
[i
].revents
= pollfds
[i
].events
& ~POLLPRI
;
667 adns__returning(ads
,0);
671 void adns__autosys(adns_state ads
, struct timeval now
) {
672 if (ads
->iflags
& adns_if_noautosys
) return;
673 adns_processany(ads
);
676 int adns__internal_check(adns_state ads
,
677 adns_query
*query_io
,
678 adns_answer
**answer
,
684 if (ads
->output
.head
) {
685 qu
= ads
->output
.head
;
686 } else if (ads
->udpw
.head
|| ads
->tcpw
.head
) {
692 if (qu
->id
>=0) return EAGAIN
;
694 LIST_UNLINK(ads
->output
,qu
);
696 if (context_r
) *context_r
= qu
->ctx
.ext
;
702 int adns_wait(adns_state ads
,
703 adns_query
*query_io
,
704 adns_answer
**answer_r
,
707 fd_set readfds
, writefds
, exceptfds
;
708 struct timeval tvbuf
, *tvp
;
710 adns__consistency(ads
,*query_io
,cc_entex
);
712 r
= adns__internal_check(ads
,query_io
,answer_r
,context_r
);
713 if (r
!= EAGAIN
) break;
715 FD_ZERO(&readfds
); FD_ZERO(&writefds
); FD_ZERO(&exceptfds
);
716 adns_beforeselect(ads
,&maxfd
,&readfds
,&writefds
,&exceptfds
,&tvp
,&tvbuf
,0);
718 rsel
= select(maxfd
,&readfds
,&writefds
,&exceptfds
,tvp
);
720 if (errno
== EINTR
) {
721 if (ads
->iflags
& adns_if_eintr
) { r
= EINTR
; break; }
723 adns__diag(ads
,-1,0,"select failed in wait: %s",strerror(errno
));
724 adns_globalsystemfailure(ads
);
728 adns_afterselect(ads
,maxfd
,&readfds
,&writefds
,&exceptfds
,0);
731 adns__returning(ads
,0);
735 int adns_check(adns_state ads
,
736 adns_query
*query_io
,
737 adns_answer
**answer_r
,
742 adns__consistency(ads
,*query_io
,cc_entex
);
743 r
= gettimeofday(&now
,0);
744 if (!r
) adns__autosys(ads
,now
);
746 r
= adns__internal_check(ads
,query_io
,answer_r
,context_r
);
747 adns__returning(ads
,0);