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Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.82 by root, Thu Aug 21 18:45:16 2008 UTC vs.
Revision 1.116 by root, Tue Feb 10 14:07:43 2009 UTC

14 14
15AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent 15AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
16 16
17=cut 17=cut
18 18
19our $VERSION = 4.232; 19our $VERSION = 4.331;
20 20
21=head1 SYNOPSIS 21=head1 SYNOPSIS
22 22
23 use AnyEvent; 23 use AnyEvent;
24 use AnyEvent::Handle; 24 use AnyEvent::Handle;
27 27
28 my $handle = 28 my $handle =
29 AnyEvent::Handle->new ( 29 AnyEvent::Handle->new (
30 fh => \*STDIN, 30 fh => \*STDIN,
31 on_eof => sub { 31 on_eof => sub {
32 $cv->broadcast; 32 $cv->send;
33 }, 33 },
34 ); 34 );
35 35
36 # send some request line 36 # send some request line
37 $handle->push_write ("getinfo\015\012"); 37 $handle->push_write ("getinfo\015\012");
49 49
50This module is a helper module to make it easier to do event-based I/O on 50This module is a helper module to make it easier to do event-based I/O on
51filehandles. For utility functions for doing non-blocking connects and accepts 51filehandles. For utility functions for doing non-blocking connects and accepts
52on sockets see L<AnyEvent::Util>. 52on sockets see L<AnyEvent::Util>.
53 53
54The L<AnyEvent::Intro> tutorial contains some well-documented
55AnyEvent::Handle examples.
56
54In the following, when the documentation refers to of "bytes" then this 57In the following, when the documentation refers to of "bytes" then this
55means characters. As sysread and syswrite are used for all I/O, their 58means characters. As sysread and syswrite are used for all I/O, their
56treatment of characters applies to this module as well. 59treatment of characters applies to this module as well.
57 60
58All callbacks will be invoked with the handle object as their first 61All callbacks will be invoked with the handle object as their first
70 73
71=item fh => $filehandle [MANDATORY] 74=item fh => $filehandle [MANDATORY]
72 75
73The filehandle this L<AnyEvent::Handle> object will operate on. 76The filehandle this L<AnyEvent::Handle> object will operate on.
74 77
75NOTE: The filehandle will be set to non-blocking (using 78NOTE: The filehandle will be set to non-blocking mode (using
76AnyEvent::Util::fh_nonblocking). 79C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
80that mode.
77 81
78=item on_eof => $cb->($handle) 82=item on_eof => $cb->($handle)
79 83
80Set the callback to be called when an end-of-file condition is detected, 84Set the callback to be called when an end-of-file condition is detected,
81i.e. in the case of a socket, when the other side has closed the 85i.e. in the case of a socket, when the other side has closed the
82connection cleanly. 86connection cleanly.
83 87
84For sockets, this just means that the other side has stopped sending data, 88For sockets, this just means that the other side has stopped sending data,
85you can still try to write data, and, in fact, one can return from the eof 89you can still try to write data, and, in fact, one can return from the EOF
86callback and continue writing data, as only the read part has been shut 90callback and continue writing data, as only the read part has been shut
87down. 91down.
88 92
89While not mandatory, it is I<highly> recommended to set an eof callback, 93While not mandatory, it is I<highly> recommended to set an EOF callback,
90otherwise you might end up with a closed socket while you are still 94otherwise you might end up with a closed socket while you are still
91waiting for data. 95waiting for data.
92 96
93If an EOF condition has been detected but no C<on_eof> callback has been 97If an EOF condition has been detected but no C<on_eof> callback has been
94set, then a fatal error will be raised with C<$!> set to <0>. 98set, then a fatal error will be raised with C<$!> set to <0>.
99occured, such as not being able to resolve the hostname, failure to 103occured, such as not being able to resolve the hostname, failure to
100connect or a read error. 104connect or a read error.
101 105
102Some errors are fatal (which is indicated by C<$fatal> being true). On 106Some errors are fatal (which is indicated by C<$fatal> being true). On
103fatal errors the handle object will be shut down and will not be usable 107fatal errors the handle object will be shut down and will not be usable
104(but you are free to look at the current C< ->rbuf >). Examples of fatal 108(but you are free to look at the current C<< ->rbuf >>). Examples of fatal
105errors are an EOF condition with active (but unsatisifable) read watchers 109errors are an EOF condition with active (but unsatisifable) read watchers
106(C<EPIPE>) or I/O errors. 110(C<EPIPE>) or I/O errors.
107 111
108Non-fatal errors can be retried by simply returning, but it is recommended 112Non-fatal errors can be retried by simply returning, but it is recommended
109to simply ignore this parameter and instead abondon the handle object 113to simply ignore this parameter and instead abondon the handle object
148=item timeout => $fractional_seconds 152=item timeout => $fractional_seconds
149 153
150If non-zero, then this enables an "inactivity" timeout: whenever this many 154If non-zero, then this enables an "inactivity" timeout: whenever this many
151seconds pass without a successful read or write on the underlying file 155seconds pass without a successful read or write on the underlying file
152handle, the C<on_timeout> callback will be invoked (and if that one is 156handle, the C<on_timeout> callback will be invoked (and if that one is
153missing, an C<ETIMEDOUT> error will be raised). 157missing, a non-fatal C<ETIMEDOUT> error will be raised).
154 158
155Note that timeout processing is also active when you currently do not have 159Note that timeout processing is also active when you currently do not have
156any outstanding read or write requests: If you plan to keep the connection 160any outstanding read or write requests: If you plan to keep the connection
157idle then you should disable the timout temporarily or ignore the timeout 161idle then you should disable the timout temporarily or ignore the timeout
158in the C<on_timeout> callback. 162in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
163restart the timeout.
159 164
160Zero (the default) disables this timeout. 165Zero (the default) disables this timeout.
161 166
162=item on_timeout => $cb->($handle) 167=item on_timeout => $cb->($handle)
163 168
167 172
168=item rbuf_max => <bytes> 173=item rbuf_max => <bytes>
169 174
170If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>) 175If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
171when the read buffer ever (strictly) exceeds this size. This is useful to 176when the read buffer ever (strictly) exceeds this size. This is useful to
172avoid denial-of-service attacks. 177avoid some forms of denial-of-service attacks.
173 178
174For example, a server accepting connections from untrusted sources should 179For example, a server accepting connections from untrusted sources should
175be configured to accept only so-and-so much data that it cannot act on 180be configured to accept only so-and-so much data that it cannot act on
176(for example, when expecting a line, an attacker could send an unlimited 181(for example, when expecting a line, an attacker could send an unlimited
177amount of data without a callback ever being called as long as the line 182amount of data without a callback ever being called as long as the line
178isn't finished). 183isn't finished).
179 184
180=item autocork => <boolean> 185=item autocork => <boolean>
181 186
182When disabled (the default), then C<push_write> will try to immediately 187When disabled (the default), then C<push_write> will try to immediately
183write the data to the handle if possible. This avoids having to register 188write the data to the handle, if possible. This avoids having to register
184a write watcher and wait for the next event loop iteration, but can be 189a write watcher and wait for the next event loop iteration, but can
185inefficient if you write multiple small chunks (this disadvantage is 190be inefficient if you write multiple small chunks (on the wire, this
186usually avoided by your kernel's nagle algorithm, see C<low_delay>). 191disadvantage is usually avoided by your kernel's nagle algorithm, see
192C<no_delay>, but this option can save costly syscalls).
187 193
188When enabled, then writes will always be queued till the next event loop 194When enabled, then writes will always be queued till the next event loop
189iteration. This is efficient when you do many small writes per iteration, 195iteration. This is efficient when you do many small writes per iteration,
190but less efficient when you do a single write only. 196but less efficient when you do a single write only per iteration (or when
197the write buffer often is full). It also increases write latency.
191 198
192=item no_delay => <boolean> 199=item no_delay => <boolean>
193 200
194When doing small writes on sockets, your operating system kernel might 201When doing small writes on sockets, your operating system kernel might
195wait a bit for more data before actually sending it out. This is called 202wait a bit for more data before actually sending it out. This is called
196the Nagle algorithm, and usually it is beneficial. 203the Nagle algorithm, and usually it is beneficial.
197 204
198In some situations you want as low a delay as possible, which cna be 205In some situations you want as low a delay as possible, which can be
199accomplishd by setting this option to true. 206accomplishd by setting this option to a true value.
200 207
201The default is your opertaing system's default behaviour, this option 208The default is your opertaing system's default behaviour (most likely
202explicitly enables or disables it, if possible. 209enabled), this option explicitly enables or disables it, if possible.
203 210
204=item read_size => <bytes> 211=item read_size => <bytes>
205 212
206The default read block size (the amount of bytes this module will try to read 213The default read block size (the amount of bytes this module will
207during each (loop iteration). Default: C<8192>. 214try to read during each loop iteration, which affects memory
215requirements). Default: C<8192>.
208 216
209=item low_water_mark => <bytes> 217=item low_water_mark => <bytes>
210 218
211Sets the amount of bytes (default: C<0>) that make up an "empty" write 219Sets the amount of bytes (default: C<0>) that make up an "empty" write
212buffer: If the write reaches this size or gets even samller it is 220buffer: If the write reaches this size or gets even samller it is
213considered empty. 221considered empty.
214 222
223Sometimes it can be beneficial (for performance reasons) to add data to
224the write buffer before it is fully drained, but this is a rare case, as
225the operating system kernel usually buffers data as well, so the default
226is good in almost all cases.
227
215=item linger => <seconds> 228=item linger => <seconds>
216 229
217If non-zero (default: C<3600>), then the destructor of the 230If non-zero (default: C<3600>), then the destructor of the
218AnyEvent::Handle object will check wether there is still outstanding write 231AnyEvent::Handle object will check whether there is still outstanding
219data and will install a watcher that will write out this data. No errors 232write data and will install a watcher that will write this data to the
220will be reported (this mostly matches how the operating system treats 233socket. No errors will be reported (this mostly matches how the operating
221outstanding data at socket close time). 234system treats outstanding data at socket close time).
222 235
223This will not work for partial TLS data that could not yet been 236This will not work for partial TLS data that could not be encoded
224encoded. This data will be lost. 237yet. This data will be lost. Calling the C<stoptls> method in time might
238help.
225 239
226=item tls => "accept" | "connect" | Net::SSLeay::SSL object 240=item tls => "accept" | "connect" | Net::SSLeay::SSL object
227 241
228When this parameter is given, it enables TLS (SSL) mode, that means it 242When this parameter is given, it enables TLS (SSL) mode, that means
229will start making tls handshake and will transparently encrypt/decrypt 243AnyEvent will start a TLS handshake as soon as the conenction has been
230data. 244established and will transparently encrypt/decrypt data afterwards.
231 245
232TLS mode requires Net::SSLeay to be installed (it will be loaded 246TLS mode requires Net::SSLeay to be installed (it will be loaded
233automatically when you try to create a TLS handle). 247automatically when you try to create a TLS handle): this module doesn't
248have a dependency on that module, so if your module requires it, you have
249to add the dependency yourself.
234 250
235For the TLS server side, use C<accept>, and for the TLS client side of a 251Unlike TCP, TLS has a server and client side: for the TLS server side, use
236connection, use C<connect> mode. 252C<accept>, and for the TLS client side of a connection, use C<connect>
253mode.
237 254
238You can also provide your own TLS connection object, but you have 255You can also provide your own TLS connection object, but you have
239to make sure that you call either C<Net::SSLeay::set_connect_state> 256to make sure that you call either C<Net::SSLeay::set_connect_state>
240or C<Net::SSLeay::set_accept_state> on it before you pass it to 257or C<Net::SSLeay::set_accept_state> on it before you pass it to
241AnyEvent::Handle. 258AnyEvent::Handle.
242 259
260B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
261passing in the wrong integer will lead to certain crash. This most often
262happens when one uses a stylish C<< tls => 1 >> and is surprised about the
263segmentation fault.
264
243See the C<starttls> method if you need to start TLS negotiation later. 265See the C<< ->starttls >> method for when need to start TLS negotiation later.
244 266
245=item tls_ctx => $ssl_ctx 267=item tls_ctx => $ssl_ctx
246 268
247Use the given Net::SSLeay::CTX object to create the new TLS connection 269Use the given C<Net::SSLeay::CTX> object to create the new TLS connection
248(unless a connection object was specified directly). If this parameter is 270(unless a connection object was specified directly). If this parameter is
249missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 271missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
250 272
251=item json => JSON or JSON::XS object 273=item json => JSON or JSON::XS object
252 274
253This is the json coder object used by the C<json> read and write types. 275This is the json coder object used by the C<json> read and write types.
254 276
255If you don't supply it, then AnyEvent::Handle will create and use a 277If you don't supply it, then AnyEvent::Handle will create and use a
256suitable one, which will write and expect UTF-8 encoded JSON texts. 278suitable one (on demand), which will write and expect UTF-8 encoded JSON
279texts.
257 280
258Note that you are responsible to depend on the JSON module if you want to 281Note that you are responsible to depend on the JSON module if you want to
259use this functionality, as AnyEvent does not have a dependency itself. 282use this functionality, as AnyEvent does not have a dependency itself.
260 283
261=item filter_r => $cb
262
263=item filter_w => $cb
264
265These exist, but are undocumented at this time.
266
267=back 284=back
268 285
269=cut 286=cut
270 287
271sub new { 288sub new {
275 292
276 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 293 $self->{fh} or Carp::croak "mandatory argument fh is missing";
277 294
278 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 295 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
279 296
280 if ($self->{tls}) {
281 require Net::SSLeay;
282 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); 297 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
283 } 298 if $self->{tls};
284 299
285 $self->{_activity} = AnyEvent->now; 300 $self->{_activity} = AnyEvent->now;
286 $self->_timeout; 301 $self->_timeout;
287 302
288 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain}; 303 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
300 delete $self->{_tw}; 315 delete $self->{_tw};
301 delete $self->{_rw}; 316 delete $self->{_rw};
302 delete $self->{_ww}; 317 delete $self->{_ww};
303 delete $self->{fh}; 318 delete $self->{fh};
304 319
305 $self->stoptls; 320 &_freetls;
306 321
307 delete $self->{on_read}; 322 delete $self->{on_read};
308 delete $self->{_queue}; 323 delete $self->{_queue};
309} 324}
310 325
316 331
317 $! = $errno; 332 $! = $errno;
318 333
319 if ($self->{on_error}) { 334 if ($self->{on_error}) {
320 $self->{on_error}($self, $fatal); 335 $self->{on_error}($self, $fatal);
321 } else { 336 } elsif ($self->{fh}) {
322 Carp::croak "AnyEvent::Handle uncaught error: $!"; 337 Carp::croak "AnyEvent::Handle uncaught error: $!";
323 } 338 }
324} 339}
325 340
326=item $fh = $handle->fh 341=item $fh = $handle->fh
327 342
328This method returns the file handle of the L<AnyEvent::Handle> object. 343This method returns the file handle used to create the L<AnyEvent::Handle> object.
329 344
330=cut 345=cut
331 346
332sub fh { $_[0]{fh} } 347sub fh { $_[0]{fh} }
333 348
351 $_[0]{on_eof} = $_[1]; 366 $_[0]{on_eof} = $_[1];
352} 367}
353 368
354=item $handle->on_timeout ($cb) 369=item $handle->on_timeout ($cb)
355 370
356Replace the current C<on_timeout> callback, or disables the callback 371Replace the current C<on_timeout> callback, or disables the callback (but
357(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor 372not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
358argument. 373argument and method.
359 374
360=cut 375=cut
361 376
362sub on_timeout { 377sub on_timeout {
363 $_[0]{on_timeout} = $_[1]; 378 $_[0]{on_timeout} = $_[1];
364} 379}
365 380
366=item $handle->autocork ($boolean) 381=item $handle->autocork ($boolean)
367 382
368Enables or disables the current autocork behaviour (see C<autocork> 383Enables or disables the current autocork behaviour (see C<autocork>
369constructor argument). 384constructor argument). Changes will only take effect on the next write.
370 385
371=cut 386=cut
387
388sub autocork {
389 $_[0]{autocork} = $_[1];
390}
372 391
373=item $handle->no_delay ($boolean) 392=item $handle->no_delay ($boolean)
374 393
375Enables or disables the C<no_delay> setting (see constructor argument of 394Enables or disables the C<no_delay> setting (see constructor argument of
376the same name for details). 395the same name for details).
469 my ($self, $cb) = @_; 488 my ($self, $cb) = @_;
470 489
471 $self->{on_drain} = $cb; 490 $self->{on_drain} = $cb;
472 491
473 $cb->($self) 492 $cb->($self)
474 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 493 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
475} 494}
476 495
477=item $handle->push_write ($data) 496=item $handle->push_write ($data)
478 497
479Queues the given scalar to be written. You can push as much data as you 498Queues the given scalar to be written. You can push as much data as you
496 substr $self->{wbuf}, 0, $len, ""; 515 substr $self->{wbuf}, 0, $len, "";
497 516
498 $self->{_activity} = AnyEvent->now; 517 $self->{_activity} = AnyEvent->now;
499 518
500 $self->{on_drain}($self) 519 $self->{on_drain}($self)
501 if $self->{low_water_mark} >= length $self->{wbuf} 520 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
502 && $self->{on_drain}; 521 && $self->{on_drain};
503 522
504 delete $self->{_ww} unless length $self->{wbuf}; 523 delete $self->{_ww} unless length $self->{wbuf};
505 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { 524 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
506 $self->_error ($!, 1); 525 $self->_error ($!, 1);
530 549
531 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 550 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
532 ->($self, @_); 551 ->($self, @_);
533 } 552 }
534 553
535 if ($self->{filter_w}) { 554 if ($self->{tls}) {
536 $self->{filter_w}($self, \$_[0]); 555 $self->{_tls_wbuf} .= $_[0];
556
557 &_dotls ($self);
537 } else { 558 } else {
538 $self->{wbuf} .= $_[0]; 559 $self->{wbuf} .= $_[0];
539 $self->_drain_wbuf; 560 $self->_drain_wbuf;
540 } 561 }
541} 562}
558=cut 579=cut
559 580
560register_write_type netstring => sub { 581register_write_type netstring => sub {
561 my ($self, $string) = @_; 582 my ($self, $string) = @_;
562 583
563 sprintf "%d:%s,", (length $string), $string 584 (length $string) . ":$string,"
564}; 585};
565 586
566=item packstring => $format, $data 587=item packstring => $format, $data
567 588
568An octet string prefixed with an encoded length. The encoding C<$format> 589An octet string prefixed with an encoded length. The encoding C<$format>
746 ) { 767 ) {
747 $self->_error (&Errno::ENOSPC, 1), return; 768 $self->_error (&Errno::ENOSPC, 1), return;
748 } 769 }
749 770
750 while () { 771 while () {
772 $self->{rbuf} .= delete $self->{_tls_rbuf} if exists $self->{_tls_rbuf};
773
751 my $len = length $self->{rbuf}; 774 my $len = length $self->{rbuf};
752 775
753 if (my $cb = shift @{ $self->{_queue} }) { 776 if (my $cb = shift @{ $self->{_queue} }) {
754 unless ($cb->($self)) { 777 unless ($cb->($self)) {
755 if ($self->{_eof}) { 778 if ($self->{_eof}) {
777 800
778 last; # more data might arrive 801 last; # more data might arrive
779 } 802 }
780 } else { 803 } else {
781 # read side becomes idle 804 # read side becomes idle
782 delete $self->{_rw}; 805 delete $self->{_rw} unless $self->{tls};
783 last; 806 last;
784 } 807 }
785 } 808 }
786 809
787 if ($self->{_eof}) { 810 if ($self->{_eof}) {
1082An octet string prefixed with an encoded length. The encoding C<$format> 1105An octet string prefixed with an encoded length. The encoding C<$format>
1083uses the same format as a Perl C<pack> format, but must specify a single 1106uses the same format as a Perl C<pack> format, but must specify a single
1084integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an 1107integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1085optional C<!>, C<< < >> or C<< > >> modifier). 1108optional C<!>, C<< < >> or C<< > >> modifier).
1086 1109
1087DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>. 1110For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1111EPP uses a prefix of C<N> (4 octtes).
1088 1112
1089Example: read a block of data prefixed by its length in BER-encoded 1113Example: read a block of data prefixed by its length in BER-encoded
1090format (very efficient). 1114format (very efficient).
1091 1115
1092 $handle->push_read (packstring => "w", sub { 1116 $handle->push_read (packstring => "w", sub {
1122 } 1146 }
1123}; 1147};
1124 1148
1125=item json => $cb->($handle, $hash_or_arrayref) 1149=item json => $cb->($handle, $hash_or_arrayref)
1126 1150
1127Reads a JSON object or array, decodes it and passes it to the callback. 1151Reads a JSON object or array, decodes it and passes it to the
1152callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1128 1153
1129If a C<json> object was passed to the constructor, then that will be used 1154If a C<json> object was passed to the constructor, then that will be used
1130for the final decode, otherwise it will create a JSON coder expecting UTF-8. 1155for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1131 1156
1132This read type uses the incremental parser available with JSON version 1157This read type uses the incremental parser available with JSON version
1149 my $rbuf = \$self->{rbuf}; 1174 my $rbuf = \$self->{rbuf};
1150 1175
1151 my $json = $self->{json} ||= JSON->new->utf8; 1176 my $json = $self->{json} ||= JSON->new->utf8;
1152 1177
1153 sub { 1178 sub {
1154 my $ref = $json->incr_parse ($self->{rbuf}); 1179 my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1155 1180
1156 if ($ref) { 1181 if ($ref) {
1157 $self->{rbuf} = $json->incr_text; 1182 $self->{rbuf} = $json->incr_text;
1158 $json->incr_text = ""; 1183 $json->incr_text = "";
1159 $cb->($self, $ref); 1184 $cb->($self, $ref);
1160 1185
1161 1 1186 1
1187 } elsif ($@) {
1188 # error case
1189 $json->incr_skip;
1190
1191 $self->{rbuf} = $json->incr_text;
1192 $json->incr_text = "";
1193
1194 $self->_error (&Errno::EBADMSG);
1195
1196 ()
1162 } else { 1197 } else {
1163 $self->{rbuf} = ""; 1198 $self->{rbuf} = "";
1199
1164 () 1200 ()
1165 } 1201 }
1166 } 1202 }
1167}; 1203};
1168 1204
1245Note that AnyEvent::Handle will automatically C<start_read> for you when 1281Note that AnyEvent::Handle will automatically C<start_read> for you when
1246you change the C<on_read> callback or push/unshift a read callback, and it 1282you change the C<on_read> callback or push/unshift a read callback, and it
1247will automatically C<stop_read> for you when neither C<on_read> is set nor 1283will automatically C<stop_read> for you when neither C<on_read> is set nor
1248there are any read requests in the queue. 1284there are any read requests in the queue.
1249 1285
1286These methods will have no effect when in TLS mode (as TLS doesn't support
1287half-duplex connections).
1288
1250=cut 1289=cut
1251 1290
1252sub stop_read { 1291sub stop_read {
1253 my ($self) = @_; 1292 my ($self) = @_;
1254 1293
1255 delete $self->{_rw}; 1294 delete $self->{_rw} unless $self->{tls};
1256} 1295}
1257 1296
1258sub start_read { 1297sub start_read {
1259 my ($self) = @_; 1298 my ($self) = @_;
1260 1299
1261 unless ($self->{_rw} || $self->{_eof}) { 1300 unless ($self->{_rw} || $self->{_eof}) {
1262 Scalar::Util::weaken $self; 1301 Scalar::Util::weaken $self;
1263 1302
1264 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1303 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
1265 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1304 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1266 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1305 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
1267 1306
1268 if ($len > 0) { 1307 if ($len > 0) {
1269 $self->{_activity} = AnyEvent->now; 1308 $self->{_activity} = AnyEvent->now;
1270 1309
1271 $self->{filter_r} 1310 if ($self->{tls}) {
1272 ? $self->{filter_r}($self, $rbuf) 1311 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1273 : $self->{_in_drain} || $self->_drain_rbuf; 1312
1313 &_dotls ($self);
1314 } else {
1315 $self->_drain_rbuf unless $self->{_in_drain};
1316 }
1274 1317
1275 } elsif (defined $len) { 1318 } elsif (defined $len) {
1276 delete $self->{_rw}; 1319 delete $self->{_rw};
1277 $self->{_eof} = 1; 1320 $self->{_eof} = 1;
1278 $self->_drain_rbuf unless $self->{_in_drain}; 1321 $self->_drain_rbuf unless $self->{_in_drain};
1282 } 1325 }
1283 }); 1326 });
1284 } 1327 }
1285} 1328}
1286 1329
1330# poll the write BIO and send the data if applicable
1287sub _dotls { 1331sub _dotls {
1288 my ($self) = @_; 1332 my ($self) = @_;
1289 1333
1290 my $buf; 1334 my $tmp;
1291 1335
1292 if (length $self->{_tls_wbuf}) { 1336 if (length $self->{_tls_wbuf}) {
1293 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) { 1337 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1294 substr $self->{_tls_wbuf}, 0, $len, ""; 1338 substr $self->{_tls_wbuf}, 0, $tmp, "";
1295 } 1339 }
1296 } 1340 }
1297 1341
1298 if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1299 $self->{wbuf} .= $buf;
1300 $self->_drain_wbuf;
1301 }
1302
1303 while (defined ($buf = Net::SSLeay::read ($self->{tls}))) { 1342 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1304 if (length $buf) { 1343 unless (length $tmp) {
1305 $self->{rbuf} .= $buf;
1306 $self->_drain_rbuf unless $self->{_in_drain};
1307 } else {
1308 # let's treat SSL-eof as we treat normal EOF 1344 # let's treat SSL-eof as we treat normal EOF
1345 delete $self->{_rw};
1309 $self->{_eof} = 1; 1346 $self->{_eof} = 1;
1310 $self->_shutdown; 1347 &_freetls;
1311 return;
1312 } 1348 }
1313 }
1314 1349
1350 $self->{_tls_rbuf} .= $tmp;
1351 $self->_drain_rbuf unless $self->{_in_drain};
1352 $self->{tls} or return; # tls session might have gone away in callback
1353 }
1354
1315 my $err = Net::SSLeay::get_error ($self->{tls}, -1); 1355 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1316 1356
1317 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) { 1357 if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) {
1318 if ($err == Net::SSLeay::ERROR_SYSCALL ()) { 1358 if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) {
1319 return $self->_error ($!, 1); 1359 return $self->_error ($!, 1);
1320 } elsif ($err == Net::SSLeay::ERROR_SSL ()) { 1360 } elsif ($tmp == Net::SSLeay::ERROR_SSL ()) {
1321 return $self->_error (&Errno::EIO, 1); 1361 return $self->_error (&Errno::EIO, 1);
1322 } 1362 }
1323 1363
1324 # all others are fine for our purposes 1364 # all other errors are fine for our purposes
1365 }
1366
1367 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1368 $self->{wbuf} .= $tmp;
1369 $self->_drain_wbuf;
1325 } 1370 }
1326} 1371}
1327 1372
1328=item $handle->starttls ($tls[, $tls_ctx]) 1373=item $handle->starttls ($tls[, $tls_ctx])
1329 1374
1339 1384
1340The TLS connection object will end up in C<< $handle->{tls} >> after this 1385The TLS connection object will end up in C<< $handle->{tls} >> after this
1341call and can be used or changed to your liking. Note that the handshake 1386call and can be used or changed to your liking. Note that the handshake
1342might have already started when this function returns. 1387might have already started when this function returns.
1343 1388
1389If it an error to start a TLS handshake more than once per
1390AnyEvent::Handle object (this is due to bugs in OpenSSL).
1391
1344=cut 1392=cut
1345 1393
1346sub starttls { 1394sub starttls {
1347 my ($self, $ssl, $ctx) = @_; 1395 my ($self, $ssl, $ctx) = @_;
1348 1396
1349 $self->stoptls; 1397 require Net::SSLeay;
1350 1398
1399 Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
1400 if $self->{tls};
1401
1351 if ($ssl eq "accept") { 1402 if ($ssl eq "accept") {
1352 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1403 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
1353 Net::SSLeay::set_accept_state ($ssl); 1404 Net::SSLeay::set_accept_state ($ssl);
1354 } elsif ($ssl eq "connect") { 1405 } elsif ($ssl eq "connect") {
1355 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1406 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
1361 # basically, this is deep magic (because SSL_read should have the same issues) 1412 # basically, this is deep magic (because SSL_read should have the same issues)
1362 # but the openssl maintainers basically said: "trust us, it just works". 1413 # but the openssl maintainers basically said: "trust us, it just works".
1363 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1414 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
1364 # and mismaintained ssleay-module doesn't even offer them). 1415 # and mismaintained ssleay-module doesn't even offer them).
1365 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 1416 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1417 #
1418 # in short: this is a mess.
1419 #
1420 # note that we do not try to keep the length constant between writes as we are required to do.
1421 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1422 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1423 # have identity issues in that area.
1366 Net::SSLeay::CTX_set_mode ($self->{tls}, 1424 Net::SSLeay::CTX_set_mode ($self->{tls},
1367 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1425 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1368 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 1426 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
1369 1427
1370 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1428 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1371 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1429 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1372 1430
1373 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio}); 1431 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
1374 1432
1375 $self->{filter_w} = sub { 1433 &_dotls; # need to trigger the initial handshake
1376 $_[0]{_tls_wbuf} .= ${$_[1]}; 1434 $self->start_read; # make sure we actually do read
1377 &_dotls;
1378 };
1379 $self->{filter_r} = sub {
1380 Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
1381 &_dotls;
1382 };
1383} 1435}
1384 1436
1385=item $handle->stoptls 1437=item $handle->stoptls
1386 1438
1387Destroys the SSL connection, if any. Partial read or write data will be 1439Shuts down the SSL connection - this makes a proper EOF handshake by
1388lost. 1440sending a close notify to the other side, but since OpenSSL doesn't
1441support non-blocking shut downs, it is not possible to re-use the stream
1442afterwards.
1389 1443
1390=cut 1444=cut
1391 1445
1392sub stoptls { 1446sub stoptls {
1393 my ($self) = @_; 1447 my ($self) = @_;
1394 1448
1449 if ($self->{tls}) {
1450 Net::SSLeay::shutdown ($self->{tls});
1451
1452 &_dotls;
1453
1454 # we don't give a shit. no, we do, but we can't. no...
1455 # we, we... have to use openssl :/
1456 &_freetls;
1457 }
1458}
1459
1460sub _freetls {
1461 my ($self) = @_;
1462
1463 return unless $self->{tls};
1464
1395 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 1465 Net::SSLeay::free (delete $self->{tls});
1396 1466
1397 delete $self->{_rbio}; 1467 delete @$self{qw(_rbio _wbio _tls_wbuf)};
1398 delete $self->{_wbio};
1399 delete $self->{_tls_wbuf};
1400 delete $self->{filter_r};
1401 delete $self->{filter_w};
1402} 1468}
1403 1469
1404sub DESTROY { 1470sub DESTROY {
1405 my $self = shift; 1471 my $self = shift;
1406 1472
1407 $self->stoptls; 1473 &_freetls;
1408 1474
1409 my $linger = exists $self->{linger} ? $self->{linger} : 3600; 1475 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1410 1476
1411 if ($linger && length $self->{wbuf}) { 1477 if ($linger && length $self->{wbuf}) {
1412 my $fh = delete $self->{fh}; 1478 my $fh = delete $self->{fh};
1427 @linger = (); 1493 @linger = ();
1428 }); 1494 });
1429 } 1495 }
1430} 1496}
1431 1497
1498=item $handle->destroy
1499
1500Shuts down the handle object as much as possible - this call ensures that
1501no further callbacks will be invoked and resources will be freed as much
1502as possible. You must not call any methods on the object afterwards.
1503
1504Normally, you can just "forget" any references to an AnyEvent::Handle
1505object and it will simply shut down. This works in fatal error and EOF
1506callbacks, as well as code outside. It does I<NOT> work in a read or write
1507callback, so when you want to destroy the AnyEvent::Handle object from
1508within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
1509that case.
1510
1511The handle might still linger in the background and write out remaining
1512data, as specified by the C<linger> option, however.
1513
1514=cut
1515
1516sub destroy {
1517 my ($self) = @_;
1518
1519 $self->DESTROY;
1520 %$self = ();
1521}
1522
1432=item AnyEvent::Handle::TLS_CTX 1523=item AnyEvent::Handle::TLS_CTX
1433 1524
1434This function creates and returns the Net::SSLeay::CTX object used by 1525This function creates and returns the Net::SSLeay::CTX object used by
1435default for TLS mode. 1526default for TLS mode.
1436 1527
1464 } 1555 }
1465} 1556}
1466 1557
1467=back 1558=back
1468 1559
1560
1561=head1 NONFREQUENTLY ASKED QUESTIONS
1562
1563=over 4
1564
1565=item I C<undef> the AnyEvent::Handle reference inside my callback and
1566still get further invocations!
1567
1568That's because AnyEvent::Handle keeps a reference to itself when handling
1569read or write callbacks.
1570
1571It is only safe to "forget" the reference inside EOF or error callbacks,
1572from within all other callbacks, you need to explicitly call the C<<
1573->destroy >> method.
1574
1575=item I get different callback invocations in TLS mode/Why can't I pause
1576reading?
1577
1578Unlike, say, TCP, TLS connections do not consist of two independent
1579communication channels, one for each direction. Or put differently. The
1580read and write directions are not independent of each other: you cannot
1581write data unless you are also prepared to read, and vice versa.
1582
1583This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
1584callback invocations when you are not expecting any read data - the reason
1585is that AnyEvent::Handle always reads in TLS mode.
1586
1587During the connection, you have to make sure that you always have a
1588non-empty read-queue, or an C<on_read> watcher. At the end of the
1589connection (or when you no longer want to use it) you can call the
1590C<destroy> method.
1591
1592=item How do I read data until the other side closes the connection?
1593
1594If you just want to read your data into a perl scalar, the easiest way
1595to achieve this is by setting an C<on_read> callback that does nothing,
1596clearing the C<on_eof> callback and in the C<on_error> callback, the data
1597will be in C<$_[0]{rbuf}>:
1598
1599 $handle->on_read (sub { });
1600 $handle->on_eof (undef);
1601 $handle->on_error (sub {
1602 my $data = delete $_[0]{rbuf};
1603 undef $handle;
1604 });
1605
1606The reason to use C<on_error> is that TCP connections, due to latencies
1607and packets loss, might get closed quite violently with an error, when in
1608fact, all data has been received.
1609
1610It is usually better to use acknowledgements when transferring data,
1611to make sure the other side hasn't just died and you got the data
1612intact. This is also one reason why so many internet protocols have an
1613explicit QUIT command.
1614
1615=item I don't want to destroy the handle too early - how do I wait until
1616all data has been written?
1617
1618After writing your last bits of data, set the C<on_drain> callback
1619and destroy the handle in there - with the default setting of
1620C<low_water_mark> this will be called precisely when all data has been
1621written to the socket:
1622
1623 $handle->push_write (...);
1624 $handle->on_drain (sub {
1625 warn "all data submitted to the kernel\n";
1626 undef $handle;
1627 });
1628
1629=back
1630
1631
1469=head1 SUBCLASSING AnyEvent::Handle 1632=head1 SUBCLASSING AnyEvent::Handle
1470 1633
1471In many cases, you might want to subclass AnyEvent::Handle. 1634In many cases, you might want to subclass AnyEvent::Handle.
1472 1635
1473To make this easier, a given version of AnyEvent::Handle uses these 1636To make this easier, a given version of AnyEvent::Handle uses these

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