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Revision 1.82 by root, Thu Aug 21 18:45:16 2008 UTC vs.
Revision 1.141 by root, Mon Jul 6 01:03:09 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 = 4.452;
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
60 63
61=head1 METHODS 64=head1 METHODS
62 65
63=over 4 66=over 4
64 67
65=item B<new (%args)> 68=item $handle = B<new> AnyEvent::TLS fh => $filehandle, key => value...
66 69
67The constructor supports these arguments (all as key => value pairs). 70The constructor supports these arguments (all as C<< key => value >> pairs).
68 71
69=over 4 72=over 4
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>.
95 99
96=item on_error => $cb->($handle, $fatal) 100=item on_error => $cb->($handle, $fatal, $message)
97 101
98This is the error callback, which is called when, well, some error 102This is the error callback, which is called when, well, some error
99occured, such as not being able to resolve the hostname, failure to 103occured, such as not being able to resolve the hostname, failure to
100connect or a read error. 104connect or a read error.
101 105
102Some errors are fatal (which is indicated by C<$fatal> being true). On 106Some errors are fatal (which is indicated by C<$fatal> being true). On
103fatal errors the handle object will be shut down and will not be usable 107fatal errors the handle object will be shut down and will not be usable
104(but you are free to look at the current C< ->rbuf >). Examples of fatal 108(but you are free to look at the current C<< ->rbuf >>). Examples of fatal
105errors are an EOF condition with active (but unsatisifable) read watchers 109errors are an EOF condition with active (but unsatisifable) read watchers
106(C<EPIPE>) or I/O errors. 110(C<EPIPE>) or I/O errors.
111
112AnyEvent::Handle tries to find an appropriate error code for you to check
113against, but in some cases (TLS errors), this does not work well. It is
114recommended to always output the C<$message> argument in human-readable
115error messages (it's usually the same as C<"$!">).
107 116
108Non-fatal errors can be retried by simply returning, but it is recommended 117Non-fatal errors can be retried by simply returning, but it is recommended
109to simply ignore this parameter and instead abondon the handle object 118to simply ignore this parameter and instead abondon the handle object
110when this callback is invoked. Examples of non-fatal errors are timeouts 119when this callback is invoked. Examples of non-fatal errors are timeouts
111C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>). 120C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
112 121
113On callback entrance, the value of C<$!> contains the operating system 122On callback entrance, the value of C<$!> contains the operating system
114error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>). 123error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
124C<EPROTO>).
115 125
116While not mandatory, it is I<highly> recommended to set this callback, as 126While not mandatory, it is I<highly> recommended to set this callback, as
117you will not be notified of errors otherwise. The default simply calls 127you will not be notified of errors otherwise. The default simply calls
118C<croak>. 128C<croak>.
119 129
123and no read request is in the queue (unlike read queue callbacks, this 133and no read request is in the queue (unlike read queue callbacks, this
124callback will only be called when at least one octet of data is in the 134callback will only be called when at least one octet of data is in the
125read buffer). 135read buffer).
126 136
127To access (and remove data from) the read buffer, use the C<< ->rbuf >> 137To access (and remove data from) the read buffer, use the C<< ->rbuf >>
128method or access the C<$handle->{rbuf}> member directly. 138method or access the C<< $handle->{rbuf} >> member directly. Note that you
139must not enlarge or modify the read buffer, you can only remove data at
140the beginning from it.
129 141
130When an EOF condition is detected then AnyEvent::Handle will first try to 142When an EOF condition is detected then AnyEvent::Handle will first try to
131feed all the remaining data to the queued callbacks and C<on_read> before 143feed all the remaining data to the queued callbacks and C<on_read> before
132calling the C<on_eof> callback. If no progress can be made, then a fatal 144calling the C<on_eof> callback. If no progress can be made, then a fatal
133error will be raised (with C<$!> set to C<EPIPE>). 145error will be raised (with C<$!> set to C<EPIPE>).
148=item timeout => $fractional_seconds 160=item timeout => $fractional_seconds
149 161
150If non-zero, then this enables an "inactivity" timeout: whenever this many 162If non-zero, then this enables an "inactivity" timeout: whenever this many
151seconds pass without a successful read or write on the underlying file 163seconds 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 164handle, the C<on_timeout> callback will be invoked (and if that one is
153missing, an C<ETIMEDOUT> error will be raised). 165missing, a non-fatal C<ETIMEDOUT> error will be raised).
154 166
155Note that timeout processing is also active when you currently do not have 167Note 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 168any outstanding read or write requests: If you plan to keep the connection
157idle then you should disable the timout temporarily or ignore the timeout 169idle then you should disable the timout temporarily or ignore the timeout
158in the C<on_timeout> callback. 170in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
171restart the timeout.
159 172
160Zero (the default) disables this timeout. 173Zero (the default) disables this timeout.
161 174
162=item on_timeout => $cb->($handle) 175=item on_timeout => $cb->($handle)
163 176
167 180
168=item rbuf_max => <bytes> 181=item rbuf_max => <bytes>
169 182
170If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>) 183If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
171when the read buffer ever (strictly) exceeds this size. This is useful to 184when the read buffer ever (strictly) exceeds this size. This is useful to
172avoid denial-of-service attacks. 185avoid some forms of denial-of-service attacks.
173 186
174For example, a server accepting connections from untrusted sources should 187For example, a server accepting connections from untrusted sources should
175be configured to accept only so-and-so much data that it cannot act on 188be 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 189(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 190amount of data without a callback ever being called as long as the line
178isn't finished). 191isn't finished).
179 192
180=item autocork => <boolean> 193=item autocork => <boolean>
181 194
182When disabled (the default), then C<push_write> will try to immediately 195When disabled (the default), then C<push_write> will try to immediately
183write the data to the handle if possible. This avoids having to register 196write 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 197a write watcher and wait for the next event loop iteration, but can
185inefficient if you write multiple small chunks (this disadvantage is 198be inefficient if you write multiple small chunks (on the wire, this
186usually avoided by your kernel's nagle algorithm, see C<low_delay>). 199disadvantage is usually avoided by your kernel's nagle algorithm, see
200C<no_delay>, but this option can save costly syscalls).
187 201
188When enabled, then writes will always be queued till the next event loop 202When enabled, then writes will always be queued till the next event loop
189iteration. This is efficient when you do many small writes per iteration, 203iteration. This is efficient when you do many small writes per iteration,
190but less efficient when you do a single write only. 204but less efficient when you do a single write only per iteration (or when
205the write buffer often is full). It also increases write latency.
191 206
192=item no_delay => <boolean> 207=item no_delay => <boolean>
193 208
194When doing small writes on sockets, your operating system kernel might 209When doing small writes on sockets, your operating system kernel might
195wait a bit for more data before actually sending it out. This is called 210wait a bit for more data before actually sending it out. This is called
196the Nagle algorithm, and usually it is beneficial. 211the Nagle algorithm, and usually it is beneficial.
197 212
198In some situations you want as low a delay as possible, which cna be 213In some situations you want as low a delay as possible, which can be
199accomplishd by setting this option to true. 214accomplishd by setting this option to a true value.
200 215
201The default is your opertaing system's default behaviour, this option 216The default is your opertaing system's default behaviour (most likely
202explicitly enables or disables it, if possible. 217enabled), this option explicitly enables or disables it, if possible.
203 218
204=item read_size => <bytes> 219=item read_size => <bytes>
205 220
206The default read block size (the amount of bytes this module will try to read 221The default read block size (the amount of bytes this module will
207during each (loop iteration). Default: C<8192>. 222try to read during each loop iteration, which affects memory
223requirements). Default: C<8192>.
208 224
209=item low_water_mark => <bytes> 225=item low_water_mark => <bytes>
210 226
211Sets the amount of bytes (default: C<0>) that make up an "empty" write 227Sets 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 228buffer: If the write reaches this size or gets even samller it is
213considered empty. 229considered empty.
214 230
231Sometimes it can be beneficial (for performance reasons) to add data to
232the write buffer before it is fully drained, but this is a rare case, as
233the operating system kernel usually buffers data as well, so the default
234is good in almost all cases.
235
215=item linger => <seconds> 236=item linger => <seconds>
216 237
217If non-zero (default: C<3600>), then the destructor of the 238If non-zero (default: C<3600>), then the destructor of the
218AnyEvent::Handle object will check wether there is still outstanding write 239AnyEvent::Handle object will check whether there is still outstanding
219data and will install a watcher that will write out this data. No errors 240write data and will install a watcher that will write this data to the
220will be reported (this mostly matches how the operating system treats 241socket. No errors will be reported (this mostly matches how the operating
221outstanding data at socket close time). 242system treats outstanding data at socket close time).
222 243
223This will not work for partial TLS data that could not yet been 244This will not work for partial TLS data that could not be encoded
224encoded. This data will be lost. 245yet. This data will be lost. Calling the C<stoptls> method in time might
246help.
247
248=item peername => $string
249
250A string used to identify the remote site - usually the DNS hostname
251(I<not> IDN!) used to create the connection, rarely the IP address.
252
253Apart from being useful in error messages, this string is also used in TLS
254peername verification (see C<verify_peername> in L<AnyEvent::TLS>).
225 255
226=item tls => "accept" | "connect" | Net::SSLeay::SSL object 256=item tls => "accept" | "connect" | Net::SSLeay::SSL object
227 257
228When this parameter is given, it enables TLS (SSL) mode, that means it 258When this parameter is given, it enables TLS (SSL) mode, that means
229will start making tls handshake and will transparently encrypt/decrypt 259AnyEvent will start a TLS handshake as soon as the conenction has been
230data. 260established and will transparently encrypt/decrypt data afterwards.
261
262All TLS protocol errors will be signalled as C<EPROTO>, with an
263appropriate error message.
231 264
232TLS mode requires Net::SSLeay to be installed (it will be loaded 265TLS mode requires Net::SSLeay to be installed (it will be loaded
233automatically when you try to create a TLS handle). 266automatically when you try to create a TLS handle): this module doesn't
267have a dependency on that module, so if your module requires it, you have
268to add the dependency yourself.
234 269
235For the TLS server side, use C<accept>, and for the TLS client side of a 270Unlike TCP, TLS has a server and client side: for the TLS server side, use
236connection, use C<connect> mode. 271C<accept>, and for the TLS client side of a connection, use C<connect>
272mode.
237 273
238You can also provide your own TLS connection object, but you have 274You can also provide your own TLS connection object, but you have
239to make sure that you call either C<Net::SSLeay::set_connect_state> 275to 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 276or C<Net::SSLeay::set_accept_state> on it before you pass it to
241AnyEvent::Handle. 277AnyEvent::Handle. Also, this module will take ownership of this connection
278object.
242 279
280At some future point, AnyEvent::Handle might switch to another TLS
281implementation, then the option to use your own session object will go
282away.
283
284B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
285passing in the wrong integer will lead to certain crash. This most often
286happens when one uses a stylish C<< tls => 1 >> and is surprised about the
287segmentation fault.
288
243See the C<starttls> method if you need to start TLS negotiation later. 289See the C<< ->starttls >> method for when need to start TLS negotiation later.
244 290
245=item tls_ctx => $ssl_ctx 291=item tls_ctx => $anyevent_tls
246 292
247Use the given Net::SSLeay::CTX object to create the new TLS connection 293Use the given C<AnyEvent::TLS> object to create the new TLS connection
248(unless a connection object was specified directly). If this parameter is 294(unless a connection object was specified directly). If this parameter is
249missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 295missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
250 296
297Instead of an object, you can also specify a hash reference with C<< key
298=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
299new TLS context object.
300
251=item json => JSON or JSON::XS object 301=item json => JSON or JSON::XS object
252 302
253This is the json coder object used by the C<json> read and write types. 303This is the json coder object used by the C<json> read and write types.
254 304
255If you don't supply it, then AnyEvent::Handle will create and use a 305If 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. 306suitable one (on demand), which will write and expect UTF-8 encoded JSON
307texts.
257 308
258Note that you are responsible to depend on the JSON module if you want to 309Note 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. 310use this functionality, as AnyEvent does not have a dependency itself.
260 311
261=item filter_r => $cb
262
263=item filter_w => $cb
264
265These exist, but are undocumented at this time.
266
267=back 312=back
268 313
269=cut 314=cut
270 315
271sub new { 316sub new {
272 my $class = shift; 317 my $class = shift;
273
274 my $self = bless { @_ }, $class; 318 my $self = bless { @_ }, $class;
275 319
276 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 320 $self->{fh} or Carp::croak "mandatory argument fh is missing";
277 321
278 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 322 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
279
280 if ($self->{tls}) {
281 require Net::SSLeay;
282 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
283 }
284 323
285 $self->{_activity} = AnyEvent->now; 324 $self->{_activity} = AnyEvent->now;
286 $self->_timeout; 325 $self->_timeout;
287 326
327 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
328
329 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
330 if $self->{tls};
331
288 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain}; 332 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
289 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
290 333
291 $self->start_read 334 $self->start_read
292 if $self->{on_read}; 335 if $self->{on_read};
293 336
294 $self 337 $self->{fh} && $self
295} 338}
296 339
297sub _shutdown { 340sub _shutdown {
298 my ($self) = @_; 341 my ($self) = @_;
299 342
300 delete $self->{_tw}; 343 delete @$self{qw(_tw _rw _ww fh wbuf on_read _queue)};
301 delete $self->{_rw}; 344 $self->{_eof} = 1; # tell starttls et. al to stop trying
302 delete $self->{_ww};
303 delete $self->{fh};
304 345
305 $self->stoptls; 346 &_freetls;
306
307 delete $self->{on_read};
308 delete $self->{_queue};
309} 347}
310 348
311sub _error { 349sub _error {
312 my ($self, $errno, $fatal) = @_; 350 my ($self, $errno, $fatal, $message) = @_;
313 351
314 $self->_shutdown 352 $self->_shutdown
315 if $fatal; 353 if $fatal;
316 354
317 $! = $errno; 355 $! = $errno;
356 $message ||= "$!";
318 357
319 if ($self->{on_error}) { 358 if ($self->{on_error}) {
320 $self->{on_error}($self, $fatal); 359 $self->{on_error}($self, $fatal, $message);
321 } else { 360 } elsif ($self->{fh}) {
322 Carp::croak "AnyEvent::Handle uncaught error: $!"; 361 Carp::croak "AnyEvent::Handle uncaught error: $message";
323 } 362 }
324} 363}
325 364
326=item $fh = $handle->fh 365=item $fh = $handle->fh
327 366
328This method returns the file handle of the L<AnyEvent::Handle> object. 367This method returns the file handle used to create the L<AnyEvent::Handle> object.
329 368
330=cut 369=cut
331 370
332sub fh { $_[0]{fh} } 371sub fh { $_[0]{fh} }
333 372
351 $_[0]{on_eof} = $_[1]; 390 $_[0]{on_eof} = $_[1];
352} 391}
353 392
354=item $handle->on_timeout ($cb) 393=item $handle->on_timeout ($cb)
355 394
356Replace the current C<on_timeout> callback, or disables the callback 395Replace the current C<on_timeout> callback, or disables the callback (but
357(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor 396not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
358argument. 397argument and method.
359 398
360=cut 399=cut
361 400
362sub on_timeout { 401sub on_timeout {
363 $_[0]{on_timeout} = $_[1]; 402 $_[0]{on_timeout} = $_[1];
364} 403}
365 404
366=item $handle->autocork ($boolean) 405=item $handle->autocork ($boolean)
367 406
368Enables or disables the current autocork behaviour (see C<autocork> 407Enables or disables the current autocork behaviour (see C<autocork>
369constructor argument). 408constructor argument). Changes will only take effect on the next write.
370 409
371=cut 410=cut
411
412sub autocork {
413 $_[0]{autocork} = $_[1];
414}
372 415
373=item $handle->no_delay ($boolean) 416=item $handle->no_delay ($boolean)
374 417
375Enables or disables the C<no_delay> setting (see constructor argument of 418Enables or disables the C<no_delay> setting (see constructor argument of
376the same name for details). 419the same name for details).
469 my ($self, $cb) = @_; 512 my ($self, $cb) = @_;
470 513
471 $self->{on_drain} = $cb; 514 $self->{on_drain} = $cb;
472 515
473 $cb->($self) 516 $cb->($self)
474 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 517 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
475} 518}
476 519
477=item $handle->push_write ($data) 520=item $handle->push_write ($data)
478 521
479Queues the given scalar to be written. You can push as much data as you 522Queues the given scalar to be written. You can push as much data as you
496 substr $self->{wbuf}, 0, $len, ""; 539 substr $self->{wbuf}, 0, $len, "";
497 540
498 $self->{_activity} = AnyEvent->now; 541 $self->{_activity} = AnyEvent->now;
499 542
500 $self->{on_drain}($self) 543 $self->{on_drain}($self)
501 if $self->{low_water_mark} >= length $self->{wbuf} 544 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
502 && $self->{on_drain}; 545 && $self->{on_drain};
503 546
504 delete $self->{_ww} unless length $self->{wbuf}; 547 delete $self->{_ww} unless length $self->{wbuf};
505 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { 548 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
506 $self->_error ($!, 1); 549 $self->_error ($!, 1);
530 573
531 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 574 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
532 ->($self, @_); 575 ->($self, @_);
533 } 576 }
534 577
535 if ($self->{filter_w}) { 578 if ($self->{tls}) {
536 $self->{filter_w}($self, \$_[0]); 579 $self->{_tls_wbuf} .= $_[0];
580
581 &_dotls ($self);
537 } else { 582 } else {
538 $self->{wbuf} .= $_[0]; 583 $self->{wbuf} .= $_[0];
539 $self->_drain_wbuf; 584 $self->_drain_wbuf;
540 } 585 }
541} 586}
558=cut 603=cut
559 604
560register_write_type netstring => sub { 605register_write_type netstring => sub {
561 my ($self, $string) = @_; 606 my ($self, $string) = @_;
562 607
563 sprintf "%d:%s,", (length $string), $string 608 (length $string) . ":$string,"
564}; 609};
565 610
566=item packstring => $format, $data 611=item packstring => $format, $data
567 612
568An octet string prefixed with an encoded length. The encoding C<$format> 613An octet string prefixed with an encoded length. The encoding C<$format>
633 678
634 pack "w/a*", Storable::nfreeze ($ref) 679 pack "w/a*", Storable::nfreeze ($ref)
635}; 680};
636 681
637=back 682=back
683
684=item $handle->push_shutdown
685
686Sometimes you know you want to close the socket after writing your data
687before it was actually written. One way to do that is to replace your
688C<on_drain> handler by a callback that shuts down the socket. This method
689is a shorthand for just that, and replaces the C<on_drain> callback with:
690
691 sub { shutdown $_[0]{fh}, 1 } # for push_shutdown
692
693This simply shuts down the write side and signals an EOF condition to the
694the peer.
695
696You can rely on the normal read queue and C<on_eof> handling
697afterwards. This is the cleanest way to close a connection.
698
699=cut
700
701sub push_shutdown {
702 $_[0]->{on_drain} = sub { shutdown $_[0]{fh}, 1 };
703}
638 704
639=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args) 705=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
640 706
641This function (not method) lets you add your own types to C<push_write>. 707This function (not method) lets you add your own types to C<push_write>.
642Whenever the given C<type> is used, C<push_write> will invoke the code 708Whenever the given C<type> is used, C<push_write> will invoke the code
746 ) { 812 ) {
747 $self->_error (&Errno::ENOSPC, 1), return; 813 $self->_error (&Errno::ENOSPC, 1), return;
748 } 814 }
749 815
750 while () { 816 while () {
817 # we need to use a separate tls read buffer, as we must not receive data while
818 # we are draining the buffer, and this can only happen with TLS.
819 $self->{rbuf} .= delete $self->{_tls_rbuf} if exists $self->{_tls_rbuf};
820
751 my $len = length $self->{rbuf}; 821 my $len = length $self->{rbuf};
752 822
753 if (my $cb = shift @{ $self->{_queue} }) { 823 if (my $cb = shift @{ $self->{_queue} }) {
754 unless ($cb->($self)) { 824 unless ($cb->($self)) {
755 if ($self->{_eof}) { 825 if ($self->{_eof}) {
777 847
778 last; # more data might arrive 848 last; # more data might arrive
779 } 849 }
780 } else { 850 } else {
781 # read side becomes idle 851 # read side becomes idle
782 delete $self->{_rw}; 852 delete $self->{_rw} unless $self->{tls};
783 last; 853 last;
784 } 854 }
785 } 855 }
786 856
787 if ($self->{_eof}) { 857 if ($self->{_eof}) {
788 if ($self->{on_eof}) { 858 if ($self->{on_eof}) {
789 $self->{on_eof}($self) 859 $self->{on_eof}($self)
790 } else { 860 } else {
791 $self->_error (0, 1); 861 $self->_error (0, 1, "Unexpected end-of-file");
792 } 862 }
793 } 863 }
794 864
795 # may need to restart read watcher 865 # may need to restart read watcher
796 unless ($self->{_rw}) { 866 unless ($self->{_rw}) {
816 886
817=item $handle->rbuf 887=item $handle->rbuf
818 888
819Returns the read buffer (as a modifiable lvalue). 889Returns the read buffer (as a modifiable lvalue).
820 890
821You can access the read buffer directly as the C<< ->{rbuf} >> member, if 891You can access the read buffer directly as the C<< ->{rbuf} >>
822you want. 892member, if you want. However, the only operation allowed on the
893read buffer (apart from looking at it) is removing data from its
894beginning. Otherwise modifying or appending to it is not allowed and will
895lead to hard-to-track-down bugs.
823 896
824NOTE: The read buffer should only be used or modified if the C<on_read>, 897NOTE: The read buffer should only be used or modified if the C<on_read>,
825C<push_read> or C<unshift_read> methods are used. The other read methods 898C<push_read> or C<unshift_read> methods are used. The other read methods
826automatically manage the read buffer. 899automatically manage the read buffer.
827 900
1082An octet string prefixed with an encoded length. The encoding C<$format> 1155An 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 1156uses 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 1157integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1085optional C<!>, C<< < >> or C<< > >> modifier). 1158optional C<!>, C<< < >> or C<< > >> modifier).
1086 1159
1087DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>. 1160For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1161EPP uses a prefix of C<N> (4 octtes).
1088 1162
1089Example: read a block of data prefixed by its length in BER-encoded 1163Example: read a block of data prefixed by its length in BER-encoded
1090format (very efficient). 1164format (very efficient).
1091 1165
1092 $handle->push_read (packstring => "w", sub { 1166 $handle->push_read (packstring => "w", sub {
1122 } 1196 }
1123}; 1197};
1124 1198
1125=item json => $cb->($handle, $hash_or_arrayref) 1199=item json => $cb->($handle, $hash_or_arrayref)
1126 1200
1127Reads a JSON object or array, decodes it and passes it to the callback. 1201Reads a JSON object or array, decodes it and passes it to the
1202callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1128 1203
1129If a C<json> object was passed to the constructor, then that will be used 1204If a C<json> object was passed to the constructor, then that will be used
1130for the final decode, otherwise it will create a JSON coder expecting UTF-8. 1205for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1131 1206
1132This read type uses the incremental parser available with JSON version 1207This read type uses the incremental parser available with JSON version
1141=cut 1216=cut
1142 1217
1143register_read_type json => sub { 1218register_read_type json => sub {
1144 my ($self, $cb) = @_; 1219 my ($self, $cb) = @_;
1145 1220
1146 require JSON; 1221 my $json = $self->{json} ||=
1222 eval { require JSON::XS; JSON::XS->new->utf8 }
1223 || do { require JSON; JSON->new->utf8 };
1147 1224
1148 my $data; 1225 my $data;
1149 my $rbuf = \$self->{rbuf}; 1226 my $rbuf = \$self->{rbuf};
1150 1227
1151 my $json = $self->{json} ||= JSON->new->utf8;
1152
1153 sub { 1228 sub {
1154 my $ref = $json->incr_parse ($self->{rbuf}); 1229 my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1155 1230
1156 if ($ref) { 1231 if ($ref) {
1157 $self->{rbuf} = $json->incr_text; 1232 $self->{rbuf} = $json->incr_text;
1158 $json->incr_text = ""; 1233 $json->incr_text = "";
1159 $cb->($self, $ref); 1234 $cb->($self, $ref);
1160 1235
1161 1 1236 1
1237 } elsif ($@) {
1238 # error case
1239 $json->incr_skip;
1240
1241 $self->{rbuf} = $json->incr_text;
1242 $json->incr_text = "";
1243
1244 $self->_error (&Errno::EBADMSG);
1245
1246 ()
1162 } else { 1247 } else {
1163 $self->{rbuf} = ""; 1248 $self->{rbuf} = "";
1249
1164 () 1250 ()
1165 } 1251 }
1166 } 1252 }
1167}; 1253};
1168 1254
1245Note that AnyEvent::Handle will automatically C<start_read> for you when 1331Note that AnyEvent::Handle will automatically C<start_read> for you when
1246you change the C<on_read> callback or push/unshift a read callback, and it 1332you change the C<on_read> callback or push/unshift a read callback, and it
1247will automatically C<stop_read> for you when neither C<on_read> is set nor 1333will automatically C<stop_read> for you when neither C<on_read> is set nor
1248there are any read requests in the queue. 1334there are any read requests in the queue.
1249 1335
1336These methods will have no effect when in TLS mode (as TLS doesn't support
1337half-duplex connections).
1338
1250=cut 1339=cut
1251 1340
1252sub stop_read { 1341sub stop_read {
1253 my ($self) = @_; 1342 my ($self) = @_;
1254 1343
1255 delete $self->{_rw}; 1344 delete $self->{_rw} unless $self->{tls};
1256} 1345}
1257 1346
1258sub start_read { 1347sub start_read {
1259 my ($self) = @_; 1348 my ($self) = @_;
1260 1349
1261 unless ($self->{_rw} || $self->{_eof}) { 1350 unless ($self->{_rw} || $self->{_eof}) {
1262 Scalar::Util::weaken $self; 1351 Scalar::Util::weaken $self;
1263 1352
1264 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1353 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
1265 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1354 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1266 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1355 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
1267 1356
1268 if ($len > 0) { 1357 if ($len > 0) {
1269 $self->{_activity} = AnyEvent->now; 1358 $self->{_activity} = AnyEvent->now;
1270 1359
1271 $self->{filter_r} 1360 if ($self->{tls}) {
1272 ? $self->{filter_r}($self, $rbuf) 1361 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1273 : $self->{_in_drain} || $self->_drain_rbuf; 1362
1363 &_dotls ($self);
1364 } else {
1365 $self->_drain_rbuf unless $self->{_in_drain};
1366 }
1274 1367
1275 } elsif (defined $len) { 1368 } elsif (defined $len) {
1276 delete $self->{_rw}; 1369 delete $self->{_rw};
1277 $self->{_eof} = 1; 1370 $self->{_eof} = 1;
1278 $self->_drain_rbuf unless $self->{_in_drain}; 1371 $self->_drain_rbuf unless $self->{_in_drain};
1282 } 1375 }
1283 }); 1376 });
1284 } 1377 }
1285} 1378}
1286 1379
1380our $ERROR_SYSCALL;
1381our $ERROR_WANT_READ;
1382our $ERROR_ZERO_RETURN;
1383
1384sub _tls_error {
1385 my ($self, $err) = @_;
1386
1387 return $self->_error ($!, 1)
1388 if $err == Net::SSLeay::ERROR_SYSCALL ();
1389
1390 my $err =Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
1391
1392 # reduce error string to look less scary
1393 $err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
1394
1395 $self->_error (&Errno::EPROTO, 1, $err);
1396}
1397
1398# poll the write BIO and send the data if applicable
1399# also decode read data if possible
1400# this is basiclaly our TLS state machine
1401# more efficient implementations are possible with openssl,
1402# but not with the buggy and incomplete Net::SSLeay.
1287sub _dotls { 1403sub _dotls {
1288 my ($self) = @_; 1404 my ($self) = @_;
1289 1405
1290 my $buf; 1406 my $tmp;
1291 1407
1292 if (length $self->{_tls_wbuf}) { 1408 if (length $self->{_tls_wbuf}) {
1293 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) { 1409 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1294 substr $self->{_tls_wbuf}, 0, $len, ""; 1410 substr $self->{_tls_wbuf}, 0, $tmp, "";
1295 } 1411 }
1296 }
1297 1412
1413 $tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
1414 return $self->_tls_error ($tmp)
1415 if $tmp != $ERROR_WANT_READ
1416 && ($tmp != $ERROR_SYSCALL || $!)
1417 && $tmp != $ERROR_ZERO_RETURN;
1418 }
1419
1420 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1421 unless (length $tmp) {
1422 # let's treat SSL-eof as we treat normal EOF
1423 delete $self->{_rw};
1424 $self->{_eof} = 1;
1425 &_freetls;
1426 }
1427
1428 $self->{_tls_rbuf} .= $tmp;
1429 $self->_drain_rbuf unless $self->{_in_drain};
1430 $self->{tls} or return; # tls session might have gone away in callback
1431 }
1432
1433 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1434 return $self->_tls_error ($tmp)
1435 if $tmp != $ERROR_WANT_READ
1436 && ($tmp != $ERROR_SYSCALL || $!)
1437 && $tmp != $ERROR_ZERO_RETURN;
1438
1298 if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) { 1439 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1299 $self->{wbuf} .= $buf; 1440 $self->{wbuf} .= $tmp;
1300 $self->_drain_wbuf; 1441 $self->_drain_wbuf;
1301 }
1302
1303 while (defined ($buf = Net::SSLeay::read ($self->{tls}))) {
1304 if (length $buf) {
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
1309 $self->{_eof} = 1;
1310 $self->_shutdown;
1311 return;
1312 }
1313 }
1314
1315 my $err = Net::SSLeay::get_error ($self->{tls}, -1);
1316
1317 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
1318 if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
1319 return $self->_error ($!, 1);
1320 } elsif ($err == Net::SSLeay::ERROR_SSL ()) {
1321 return $self->_error (&Errno::EIO, 1);
1322 }
1323
1324 # all others are fine for our purposes
1325 } 1442 }
1326} 1443}
1327 1444
1328=item $handle->starttls ($tls[, $tls_ctx]) 1445=item $handle->starttls ($tls[, $tls_ctx])
1329 1446
1332C<starttls>. 1449C<starttls>.
1333 1450
1334The first argument is the same as the C<tls> constructor argument (either 1451The first argument is the same as the C<tls> constructor argument (either
1335C<"connect">, C<"accept"> or an existing Net::SSLeay object). 1452C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1336 1453
1337The second argument is the optional C<Net::SSLeay::CTX> object that is 1454The second argument is the optional C<AnyEvent::TLS> object that is used
1338used when AnyEvent::Handle has to create its own TLS connection object. 1455when AnyEvent::Handle has to create its own TLS connection object, or
1456a hash reference with C<< key => value >> pairs that will be used to
1457construct a new context.
1339 1458
1340The TLS connection object will end up in C<< $handle->{tls} >> after this 1459The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1341call and can be used or changed to your liking. Note that the handshake 1460context in C<< $handle->{tls_ctx} >> after this call and can be used or
1342might have already started when this function returns. 1461changed to your liking. Note that the handshake might have already started
1462when this function returns.
1343 1463
1464If it an error to start a TLS handshake more than once per
1465AnyEvent::Handle object (this is due to bugs in OpenSSL).
1466
1344=cut 1467=cut
1468
1469our %TLS_CACHE; #TODO not yet documented, should we?
1345 1470
1346sub starttls { 1471sub starttls {
1347 my ($self, $ssl, $ctx) = @_; 1472 my ($self, $ssl, $ctx) = @_;
1348 1473
1349 $self->stoptls; 1474 require Net::SSLeay;
1350 1475
1351 if ($ssl eq "accept") { 1476 Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
1352 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1477 if $self->{tls};
1353 Net::SSLeay::set_accept_state ($ssl); 1478
1354 } elsif ($ssl eq "connect") { 1479 $ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
1355 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1480 $ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
1356 Net::SSLeay::set_connect_state ($ssl); 1481 $ERROR_ZERO_RETURN = Net::SSLeay::ERROR_ZERO_RETURN ();
1482
1483 $ctx ||= $self->{tls_ctx};
1484
1485 if ("HASH" eq ref $ctx) {
1486 require AnyEvent::TLS;
1487
1488 local $Carp::CarpLevel = 1; # skip ourselves when creating a new context
1489
1490 if ($ctx->{cache}) {
1491 my $key = $ctx+0;
1492 $ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
1493 } else {
1494 $ctx = new AnyEvent::TLS %$ctx;
1495 }
1496 }
1357 } 1497
1358 1498 $self->{tls_ctx} = $ctx || TLS_CTX ();
1359 $self->{tls} = $ssl; 1499 $self->{tls} = $ssl = $self->{tls_ctx}->_get_session ($ssl, $self, $self->{peername});
1360 1500
1361 # basically, this is deep magic (because SSL_read should have the same issues) 1501 # basically, this is deep magic (because SSL_read should have the same issues)
1362 # but the openssl maintainers basically said: "trust us, it just works". 1502 # but the openssl maintainers basically said: "trust us, it just works".
1363 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1503 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
1364 # and mismaintained ssleay-module doesn't even offer them). 1504 # and mismaintained ssleay-module doesn't even offer them).
1365 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 1505 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1506 #
1507 # in short: this is a mess.
1508 #
1509 # note that we do not try to keep the length constant between writes as we are required to do.
1510 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1511 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1512 # have identity issues in that area.
1366 Net::SSLeay::CTX_set_mode ($self->{tls}, 1513# Net::SSLeay::CTX_set_mode ($ssl,
1367 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1514# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1368 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 1515# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
1516 Net::SSLeay::CTX_set_mode ($ssl, 1|2);
1369 1517
1370 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1518 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1371 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1519 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1372 1520
1373 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio}); 1521 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
1374 1522
1375 $self->{filter_w} = sub { 1523 &_dotls; # need to trigger the initial handshake
1376 $_[0]{_tls_wbuf} .= ${$_[1]}; 1524 $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} 1525}
1384 1526
1385=item $handle->stoptls 1527=item $handle->stoptls
1386 1528
1387Destroys the SSL connection, if any. Partial read or write data will be 1529Shuts down the SSL connection - this makes a proper EOF handshake by
1388lost. 1530sending a close notify to the other side, but since OpenSSL doesn't
1531support non-blocking shut downs, it is not possible to re-use the stream
1532afterwards.
1389 1533
1390=cut 1534=cut
1391 1535
1392sub stoptls { 1536sub stoptls {
1393 my ($self) = @_; 1537 my ($self) = @_;
1394 1538
1395 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 1539 if ($self->{tls}) {
1540 Net::SSLeay::shutdown ($self->{tls});
1396 1541
1397 delete $self->{_rbio}; 1542 &_dotls;
1398 delete $self->{_wbio}; 1543
1399 delete $self->{_tls_wbuf}; 1544 # we don't give a shit. no, we do, but we can't. no...
1400 delete $self->{filter_r}; 1545 # we, we... have to use openssl :/
1401 delete $self->{filter_w}; 1546 &_freetls;
1547 }
1548}
1549
1550sub _freetls {
1551 my ($self) = @_;
1552
1553 return unless $self->{tls};
1554
1555 $self->{tls_ctx}->_put_session (delete $self->{tls});
1556
1557 delete @$self{qw(_rbio _wbio _tls_wbuf)};
1402} 1558}
1403 1559
1404sub DESTROY { 1560sub DESTROY {
1405 my $self = shift; 1561 my ($self) = @_;
1406 1562
1407 $self->stoptls; 1563 &_freetls;
1408 1564
1409 my $linger = exists $self->{linger} ? $self->{linger} : 3600; 1565 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1410 1566
1411 if ($linger && length $self->{wbuf}) { 1567 if ($linger && length $self->{wbuf}) {
1412 my $fh = delete $self->{fh}; 1568 my $fh = delete $self->{fh};
1427 @linger = (); 1583 @linger = ();
1428 }); 1584 });
1429 } 1585 }
1430} 1586}
1431 1587
1588=item $handle->destroy
1589
1590Shuts down the handle object as much as possible - this call ensures that
1591no further callbacks will be invoked and as many resources as possible
1592will be freed. You must not call any methods on the object afterwards.
1593
1594Normally, you can just "forget" any references to an AnyEvent::Handle
1595object and it will simply shut down. This works in fatal error and EOF
1596callbacks, as well as code outside. It does I<NOT> work in a read or write
1597callback, so when you want to destroy the AnyEvent::Handle object from
1598within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
1599that case.
1600
1601The handle might still linger in the background and write out remaining
1602data, as specified by the C<linger> option, however.
1603
1604=cut
1605
1606sub destroy {
1607 my ($self) = @_;
1608
1609 $self->DESTROY;
1610 %$self = ();
1611}
1612
1432=item AnyEvent::Handle::TLS_CTX 1613=item AnyEvent::Handle::TLS_CTX
1433 1614
1434This function creates and returns the Net::SSLeay::CTX object used by 1615This function creates and returns the AnyEvent::TLS object used by default
1435default for TLS mode. 1616for TLS mode.
1436 1617
1437The context is created like this: 1618The context is created by calling L<AnyEvent::TLS> without any arguments.
1438
1439 Net::SSLeay::load_error_strings;
1440 Net::SSLeay::SSLeay_add_ssl_algorithms;
1441 Net::SSLeay::randomize;
1442
1443 my $CTX = Net::SSLeay::CTX_new;
1444
1445 Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
1446 1619
1447=cut 1620=cut
1448 1621
1449our $TLS_CTX; 1622our $TLS_CTX;
1450 1623
1451sub TLS_CTX() { 1624sub TLS_CTX() {
1452 $TLS_CTX || do { 1625 $TLS_CTX ||= do {
1453 require Net::SSLeay; 1626 require AnyEvent::TLS;
1454 1627
1455 Net::SSLeay::load_error_strings (); 1628 new AnyEvent::TLS
1456 Net::SSLeay::SSLeay_add_ssl_algorithms ();
1457 Net::SSLeay::randomize ();
1458
1459 $TLS_CTX = Net::SSLeay::CTX_new ();
1460
1461 Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
1462
1463 $TLS_CTX
1464 } 1629 }
1465} 1630}
1466 1631
1467=back 1632=back
1633
1634
1635=head1 NONFREQUENTLY ASKED QUESTIONS
1636
1637=over 4
1638
1639=item I C<undef> the AnyEvent::Handle reference inside my callback and
1640still get further invocations!
1641
1642That's because AnyEvent::Handle keeps a reference to itself when handling
1643read or write callbacks.
1644
1645It is only safe to "forget" the reference inside EOF or error callbacks,
1646from within all other callbacks, you need to explicitly call the C<<
1647->destroy >> method.
1648
1649=item I get different callback invocations in TLS mode/Why can't I pause
1650reading?
1651
1652Unlike, say, TCP, TLS connections do not consist of two independent
1653communication channels, one for each direction. Or put differently. The
1654read and write directions are not independent of each other: you cannot
1655write data unless you are also prepared to read, and vice versa.
1656
1657This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
1658callback invocations when you are not expecting any read data - the reason
1659is that AnyEvent::Handle always reads in TLS mode.
1660
1661During the connection, you have to make sure that you always have a
1662non-empty read-queue, or an C<on_read> watcher. At the end of the
1663connection (or when you no longer want to use it) you can call the
1664C<destroy> method.
1665
1666=item How do I read data until the other side closes the connection?
1667
1668If you just want to read your data into a perl scalar, the easiest way
1669to achieve this is by setting an C<on_read> callback that does nothing,
1670clearing the C<on_eof> callback and in the C<on_error> callback, the data
1671will be in C<$_[0]{rbuf}>:
1672
1673 $handle->on_read (sub { });
1674 $handle->on_eof (undef);
1675 $handle->on_error (sub {
1676 my $data = delete $_[0]{rbuf};
1677 undef $handle;
1678 });
1679
1680The reason to use C<on_error> is that TCP connections, due to latencies
1681and packets loss, might get closed quite violently with an error, when in
1682fact, all data has been received.
1683
1684It is usually better to use acknowledgements when transferring data,
1685to make sure the other side hasn't just died and you got the data
1686intact. This is also one reason why so many internet protocols have an
1687explicit QUIT command.
1688
1689=item I don't want to destroy the handle too early - how do I wait until
1690all data has been written?
1691
1692After writing your last bits of data, set the C<on_drain> callback
1693and destroy the handle in there - with the default setting of
1694C<low_water_mark> this will be called precisely when all data has been
1695written to the socket:
1696
1697 $handle->push_write (...);
1698 $handle->on_drain (sub {
1699 warn "all data submitted to the kernel\n";
1700 undef $handle;
1701 });
1702
1703=back
1704
1468 1705
1469=head1 SUBCLASSING AnyEvent::Handle 1706=head1 SUBCLASSING AnyEvent::Handle
1470 1707
1471In many cases, you might want to subclass AnyEvent::Handle. 1708In many cases, you might want to subclass AnyEvent::Handle.
1472 1709

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