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Revision 1.43 by root, Wed May 28 23:57:38 2008 UTC vs.
Revision 1.253 by root, Fri Feb 7 15:06:01 2020 UTC

1package AnyEvent::Handle;
2
3no warnings;
4use strict;
5
6use AnyEvent ();
7use AnyEvent::Util qw(WSAEWOULDBLOCK);
8use Scalar::Util ();
9use Carp ();
10use Fcntl ();
11use Errno qw(EAGAIN EINTR);
12use Time::HiRes qw(time);
13
14=head1 NAME 1=head1 NAME
15 2
16AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent 3AnyEvent::Handle - non-blocking I/O on streaming handles via AnyEvent
17
18=cut
19
20our $VERSION = '0.04';
21 4
22=head1 SYNOPSIS 5=head1 SYNOPSIS
23 6
24 use AnyEvent; 7 use AnyEvent;
25 use AnyEvent::Handle; 8 use AnyEvent::Handle;
26 9
27 my $cv = AnyEvent->condvar; 10 my $cv = AnyEvent->condvar;
28 11
29 my $handle = 12 my $hdl; $hdl = new AnyEvent::Handle
30 AnyEvent::Handle->new (
31 fh => \*STDIN, 13 fh => \*STDIN,
32 on_eof => sub { 14 on_error => sub {
33 $cv->broadcast; 15 my ($hdl, $fatal, $msg) = @_;
34 }, 16 AE::log error => $msg;
17 $hdl->destroy;
18 $cv->send;
35 ); 19 };
36 20
37 # send some request line 21 # send some request line
38 $handle->push_write ("getinfo\015\012"); 22 $hdl->push_write ("getinfo\015\012");
39 23
40 # read the response line 24 # read the response line
41 $handle->push_read (line => sub { 25 $hdl->push_read (line => sub {
42 my ($handle, $line) = @_; 26 my ($hdl, $line) = @_;
43 warn "read line <$line>\n"; 27 say "got line <$line>";
44 $cv->send; 28 $cv->send;
45 }); 29 });
46 30
47 $cv->recv; 31 $cv->recv;
48 32
49=head1 DESCRIPTION 33=head1 DESCRIPTION
50 34
51This module is a helper module to make it easier to do event-based I/O on 35This is a helper module to make it easier to do event-based I/O
52filehandles. For utility functions for doing non-blocking connects and accepts 36on stream-based filehandles (sockets, pipes, and other stream
53on sockets see L<AnyEvent::Util>. 37things). Specifically, it doesn't work as expected on files, packet-based
38sockets or similar things.
54 39
40The L<AnyEvent::Intro> tutorial contains some well-documented
41AnyEvent::Handle examples.
42
55In the following, when the documentation refers to of "bytes" then this 43In the following, where the documentation refers to "bytes", it means
56means characters. As sysread and syswrite are used for all I/O, their 44characters. As sysread and syswrite are used for all I/O, their
57treatment of characters applies to this module as well. 45treatment of characters applies to this module as well.
46
47At the very minimum, you should specify C<fh> or C<connect>, and the
48C<on_error> callback.
58 49
59All callbacks will be invoked with the handle object as their first 50All callbacks will be invoked with the handle object as their first
60argument. 51argument.
61 52
53=cut
54
55package AnyEvent::Handle;
56
57use Scalar::Util ();
58use List::Util ();
59use Carp ();
60use Errno qw(EAGAIN EWOULDBLOCK EINTR);
61
62use AnyEvent (); BEGIN { AnyEvent::common_sense }
63use AnyEvent::Util qw(WSAEWOULDBLOCK);
64
65our $VERSION = $AnyEvent::VERSION;
66
67sub _load_func($) {
68 my $func = $_[0];
69
70 unless (defined &$func) {
71 my $pkg = $func;
72 do {
73 $pkg =~ s/::[^:]+$//
74 or return;
75 eval "require $pkg";
76 } until defined &$func;
77 }
78
79 \&$func
80}
81
82sub MAX_READ_SIZE() { 131072 }
83
62=head1 METHODS 84=head1 METHODS
63 85
64=over 4 86=over 4
65 87
66=item B<new (%args)> 88=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
67 89
68The constructor supports these arguments (all as key => value pairs). 90The constructor supports these arguments (all as C<< key => value >> pairs).
69 91
70=over 4 92=over 4
71 93
72=item fh => $filehandle [MANDATORY] 94=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
73 95
74The filehandle this L<AnyEvent::Handle> object will operate on. 96The filehandle this L<AnyEvent::Handle> object will operate on.
75
76NOTE: The filehandle will be set to non-blocking (using 97NOTE: The filehandle will be set to non-blocking mode (using
77AnyEvent::Util::fh_nonblocking). 98C<AnyEvent::fh_unblock>) by the constructor and needs to stay in
99that mode.
78 100
79=item on_eof => $cb->($handle) 101=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
80 102
81Set the callback to be called on EOF. 103Try to connect to the specified host and service (port), using
104C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
105default C<peername>.
82 106
83While not mandatory, it is highly recommended to set an eof callback, 107You have to specify either this parameter, or C<fh>, above.
84otherwise you might end up with a closed socket while you are still
85waiting for data.
86 108
109It is possible to push requests on the read and write queues, and modify
110properties of the stream, even while AnyEvent::Handle is connecting.
111
112When this parameter is specified, then the C<on_prepare>,
113C<on_connect_error> and C<on_connect> callbacks will be called under the
114appropriate circumstances:
115
116=over 4
117
87=item on_error => $cb->($handle) 118=item on_prepare => $cb->($handle)
88 119
120This (rarely used) callback is called before a new connection is
121attempted, but after the file handle has been created (you can access that
122file handle via C<< $handle->{fh} >>). It could be used to prepare the
123file handle with parameters required for the actual connect (as opposed to
124settings that can be changed when the connection is already established).
125
126The return value of this callback should be the connect timeout value in
127seconds (or C<0>, or C<undef>, or the empty list, to indicate that the
128default timeout is to be used).
129
130=item on_connect => $cb->($handle, $host, $port, $retry->())
131
132This callback is called when a connection has been successfully established.
133
134The peer's numeric host and port (the socket peername) are passed as
135parameters, together with a retry callback. At the time it is called the
136read and write queues, EOF status, TLS status and similar properties of
137the handle will have been reset.
138
139If, for some reason, the handle is not acceptable, calling C<$retry> will
140continue with the next connection target (in case of multi-homed hosts or
141SRV records there can be multiple connection endpoints). The C<$retry>
142callback can be invoked after the connect callback returns, i.e. one can
143start a handshake and then decide to retry with the next host if the
144handshake fails.
145
146In most cases, you should ignore the C<$retry> parameter.
147
148=item on_connect_error => $cb->($handle, $message)
149
150This callback is called when the connection could not be
151established. C<$!> will contain the relevant error code, and C<$message> a
152message describing it (usually the same as C<"$!">).
153
154If this callback isn't specified, then C<on_error> will be called with a
155fatal error instead.
156
157=back
158
159=item on_error => $cb->($handle, $fatal, $message)
160
89This is the fatal error callback, that is called when, well, a fatal error 161This is the error callback, which is called when, well, some error
90occurs, such as not being able to resolve the hostname, failure to connect 162occured, such as not being able to resolve the hostname, failure to
91or a read error. 163connect, or a read error.
92 164
93The object will not be in a usable state when this callback has been 165Some errors are fatal (which is indicated by C<$fatal> being true). On
94called. 166fatal errors the handle object will be destroyed (by a call to C<< ->
167destroy >>) after invoking the error callback (which means you are free to
168examine the handle object). Examples of fatal errors are an EOF condition
169with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
170cases where the other side can close the connection at will, it is
171often easiest to not report C<EPIPE> errors in this callback.
95 172
173AnyEvent::Handle tries to find an appropriate error code for you to check
174against, but in some cases (TLS errors), this does not work well.
175
176If you report the error to the user, it is recommended to always output
177the C<$message> argument in human-readable error messages (you don't need
178to report C<"$!"> if you report C<$message>).
179
180If you want to react programmatically to the error, then looking at C<$!>
181and comparing it against some of the documented C<Errno> values is usually
182better than looking at the C<$message>.
183
184Non-fatal errors can be retried by returning, but it is recommended
185to simply ignore this parameter and instead abondon the handle object
186when this callback is invoked. Examples of non-fatal errors are timeouts
187C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
188
96On callback entrance, the value of C<$!> contains the operating system 189On entry to the callback, the value of C<$!> contains the operating
97error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>). 190system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
98 191C<EPROTO>).
99The callback should throw an exception. If it returns, then
100AnyEvent::Handle will C<croak> for you.
101 192
102While not mandatory, it is I<highly> recommended to set this callback, as 193While not mandatory, it is I<highly> recommended to set this callback, as
103you will not be notified of errors otherwise. The default simply calls 194you will not be notified of errors otherwise. The default just calls
104die. 195C<croak>.
105 196
106=item on_read => $cb->($handle) 197=item on_read => $cb->($handle)
107 198
108This sets the default read callback, which is called when data arrives 199This sets the default read callback, which is called when data arrives
109and no read request is in the queue. 200and no read request is in the queue (unlike read queue callbacks, this
201callback will only be called when at least one octet of data is in the
202read buffer).
110 203
111To access (and remove data from) the read buffer, use the C<< ->rbuf >> 204To access (and remove data from) the read buffer, use the C<< ->rbuf >>
112method or access the C<$handle->{rbuf}> member directly. 205method or access the C<< $handle->{rbuf} >> member directly. Note that you
206must not enlarge or modify the read buffer, you can only remove data at
207the beginning from it.
113 208
209You can also call C<< ->push_read (...) >> or any other function that
210modifies the read queue. Or do both. Or ...
211
114When an EOF condition is detected then AnyEvent::Handle will first try to 212When an EOF condition is detected, AnyEvent::Handle will first try to
115feed all the remaining data to the queued callbacks and C<on_read> before 213feed all the remaining data to the queued callbacks and C<on_read> before
116calling the C<on_eof> callback. If no progress can be made, then a fatal 214calling the C<on_eof> callback. If no progress can be made, then a fatal
117error will be raised (with C<$!> set to C<EPIPE>). 215error will be raised (with C<$!> set to C<EPIPE>).
118 216
217Note that, unlike requests in the read queue, an C<on_read> callback
218doesn't mean you I<require> some data: if there is an EOF and there
219are outstanding read requests then an error will be flagged. With an
220C<on_read> callback, the C<on_eof> callback will be invoked.
221
222=item on_eof => $cb->($handle)
223
224Set the callback to be called when an end-of-file condition is detected,
225i.e. in the case of a socket, when the other side has closed the
226connection cleanly, and there are no outstanding read requests in the
227queue (if there are read requests, then an EOF counts as an unexpected
228connection close and will be flagged as an error).
229
230For sockets, this just means that the other side has stopped sending data,
231you can still try to write data, and, in fact, one can return from the EOF
232callback and continue writing data, as only the read part has been shut
233down.
234
235If an EOF condition has been detected but no C<on_eof> callback has been
236set, then a fatal error will be raised with C<$!> set to <0>.
237
119=item on_drain => $cb->($handle) 238=item on_drain => $cb->($handle)
120 239
121This sets the callback that is called when the write buffer becomes empty 240This sets the callback that is called once when the write buffer becomes
122(or when the callback is set and the buffer is empty already). 241empty (and immediately when the handle object is created).
123 242
124To append to the write buffer, use the C<< ->push_write >> method. 243To append to the write buffer, use the C<< ->push_write >> method.
125 244
245This callback is useful when you don't want to put all of your write data
246into the queue at once, for example, when you want to write the contents
247of some file to the socket you might not want to read the whole file into
248memory and push it into the queue, but instead only read more data from
249the file when the write queue becomes empty.
250
126=item timeout => $fractional_seconds 251=item timeout => $fractional_seconds
127 252
253=item rtimeout => $fractional_seconds
254
255=item wtimeout => $fractional_seconds
256
128If non-zero, then this enables an "inactivity" timeout: whenever this many 257If non-zero, then these enables an "inactivity" timeout: whenever this
129seconds pass without a successful read or write on the underlying file 258many seconds pass without a successful read or write on the underlying
130handle, the C<on_timeout> callback will be invoked (and if that one is 259file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
131missing, an C<ETIMEDOUT> errror will be raised). 260will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
261error will be raised).
132 262
263There are three variants of the timeouts that work independently of each
264other, for both read and write (triggered when nothing was read I<OR>
265written), just read (triggered when nothing was read), and just write:
266C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
267C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
268C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
269
133Note that timeout processing is also active when you currently do not have 270Note that timeout processing is active even when you do not have any
134any outstanding read or write requests: If you plan to keep the connection 271outstanding read or write requests: If you plan to keep the connection
135idle then you should disable the timout temporarily or ignore the timeout 272idle then you should disable the timeout temporarily or ignore the
136in the C<on_timeout> callback. 273timeout in the corresponding C<on_timeout> callback, in which case
274AnyEvent::Handle will simply restart the timeout.
137 275
138Zero (the default) disables this timeout. 276Zero (the default) disables the corresponding timeout.
139 277
140=item on_timeout => $cb->($handle) 278=item on_timeout => $cb->($handle)
279
280=item on_rtimeout => $cb->($handle)
281
282=item on_wtimeout => $cb->($handle)
141 283
142Called whenever the inactivity timeout passes. If you return from this 284Called whenever the inactivity timeout passes. If you return from this
143callback, then the timeout will be reset as if some activity had happened, 285callback, then the timeout will be reset as if some activity had happened,
144so this condition is not fatal in any way. 286so this condition is not fatal in any way.
145 287
146=item rbuf_max => <bytes> 288=item rbuf_max => <bytes>
147 289
148If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>) 290If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
149when the read buffer ever (strictly) exceeds this size. This is useful to 291when the read buffer ever (strictly) exceeds this size. This is useful to
150avoid denial-of-service attacks. 292avoid some forms of denial-of-service attacks.
151 293
152For example, a server accepting connections from untrusted sources should 294For example, a server accepting connections from untrusted sources should
153be configured to accept only so-and-so much data that it cannot act on 295be configured to accept only so-and-so much data that it cannot act on
154(for example, when expecting a line, an attacker could send an unlimited 296(for example, when expecting a line, an attacker could send an unlimited
155amount of data without a callback ever being called as long as the line 297amount of data without a callback ever being called as long as the line
156isn't finished). 298isn't finished).
157 299
300=item wbuf_max => <bytes>
301
302If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
303when the write buffer ever (strictly) exceeds this size. This is useful to
304avoid some forms of denial-of-service attacks.
305
306Although the units of this parameter is bytes, this is the I<raw> number
307of bytes not yet accepted by the kernel. This can make a difference when
308you e.g. use TLS, as TLS typically makes your write data larger (but it
309can also make it smaller due to compression).
310
311As an example of when this limit is useful, take a chat server that sends
312chat messages to a client. If the client does not read those in a timely
313manner then the send buffer in the server would grow unbounded.
314
315=item autocork => <boolean>
316
317When disabled (the default), C<push_write> will try to immediately
318write the data to the handle if possible. This avoids having to register
319a write watcher and wait for the next event loop iteration, but can
320be inefficient if you write multiple small chunks (on the wire, this
321disadvantage is usually avoided by your kernel's nagle algorithm, see
322C<no_delay>, but this option can save costly syscalls).
323
324When enabled, writes will always be queued till the next event loop
325iteration. This is efficient when you do many small writes per iteration,
326but less efficient when you do a single write only per iteration (or when
327the write buffer often is full). It also increases write latency.
328
329=item no_delay => <boolean>
330
331When doing small writes on sockets, your operating system kernel might
332wait a bit for more data before actually sending it out. This is called
333the Nagle algorithm, and usually it is beneficial.
334
335In some situations you want as low a delay as possible, which can be
336accomplishd by setting this option to a true value.
337
338The default is your operating system's default behaviour (most likely
339enabled). This option explicitly enables or disables it, if possible.
340
341=item keepalive => <boolean>
342
343Enables (default disable) the SO_KEEPALIVE option on the stream socket:
344normally, TCP connections have no time-out once established, so TCP
345connections, once established, can stay alive forever even when the other
346side has long gone. TCP keepalives are a cheap way to take down long-lived
347TCP connections when the other side becomes unreachable. While the default
348is OS-dependent, TCP keepalives usually kick in after around two hours,
349and, if the other side doesn't reply, take down the TCP connection some 10
350to 15 minutes later.
351
352It is harmless to specify this option for file handles that do not support
353keepalives, and enabling it on connections that are potentially long-lived
354is usually a good idea.
355
356=item oobinline => <boolean>
357
358BSD majorly fucked up the implementation of TCP urgent data. The result
359is that almost no OS implements TCP according to the specs, and every OS
360implements it slightly differently.
361
362If you want to handle TCP urgent data, then setting this flag (the default
363is enabled) gives you the most portable way of getting urgent data, by
364putting it into the stream.
365
366Since BSD emulation of OOB data on top of TCP's urgent data can have
367security implications, AnyEvent::Handle sets this flag automatically
368unless explicitly specified. Note that setting this flag after
369establishing a connection I<may> be a bit too late (data loss could
370already have occured on BSD systems), but at least it will protect you
371from most attacks.
372
158=item read_size => <bytes> 373=item read_size => <bytes>
159 374
160The default read block size (the amount of bytes this module will try to read 375The initial read block size, the number of bytes this module will try
161on each [loop iteration). Default: C<4096>. 376to read during each loop iteration. Each handle object will consume
377at least this amount of memory for the read buffer as well, so when
378handling many connections watch out for memory requirements). See also
379C<max_read_size>. Default: C<2048>.
380
381=item max_read_size => <bytes>
382
383The maximum read buffer size used by the dynamic adjustment
384algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
385one go it will double C<read_size> up to the maximum given by this
386option. Default: C<131072> or C<read_size>, whichever is higher.
162 387
163=item low_water_mark => <bytes> 388=item low_water_mark => <bytes>
164 389
165Sets the amount of bytes (default: C<0>) that make up an "empty" write 390Sets the number of bytes (default: C<0>) that make up an "empty" write
166buffer: If the write reaches this size or gets even samller it is 391buffer: If the buffer reaches this size or gets even samller it is
167considered empty. 392considered empty.
168 393
394Sometimes it can be beneficial (for performance reasons) to add data to
395the write buffer before it is fully drained, but this is a rare case, as
396the operating system kernel usually buffers data as well, so the default
397is good in almost all cases.
398
399=item linger => <seconds>
400
401If this is non-zero (default: C<3600>), the destructor of the
402AnyEvent::Handle object will check whether there is still outstanding
403write data and will install a watcher that will write this data to the
404socket. No errors will be reported (this mostly matches how the operating
405system treats outstanding data at socket close time).
406
407This will not work for partial TLS data that could not be encoded
408yet. This data will be lost. Calling the C<stoptls> method in time might
409help.
410
411=item peername => $string
412
413A string used to identify the remote site - usually the DNS hostname
414(I<not> IDN!) used to create the connection, rarely the IP address.
415
416Apart from being useful in error messages, this string is also used in TLS
417peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
418verification will be skipped when C<peername> is not specified or is
419C<undef>.
420
169=item tls => "accept" | "connect" | Net::SSLeay::SSL object 421=item tls => "accept" | "connect" | Net::SSLeay::SSL object
170 422
171When this parameter is given, it enables TLS (SSL) mode, that means it 423When this parameter is given, it enables TLS (SSL) mode, that means
172will start making tls handshake and will transparently encrypt/decrypt 424AnyEvent will start a TLS handshake as soon as the connection has been
173data. 425established and will transparently encrypt/decrypt data afterwards.
426
427All TLS protocol errors will be signalled as C<EPROTO>, with an
428appropriate error message.
174 429
175TLS mode requires Net::SSLeay to be installed (it will be loaded 430TLS mode requires Net::SSLeay to be installed (it will be loaded
176automatically when you try to create a TLS handle). 431automatically when you try to create a TLS handle): this module doesn't
432have a dependency on that module, so if your module requires it, you have
433to add the dependency yourself. If Net::SSLeay cannot be loaded or is too
434old, you get an C<EPROTO> error.
177 435
178For the TLS server side, use C<accept>, and for the TLS client side of a 436Unlike TCP, TLS has a server and client side: for the TLS server side, use
179connection, use C<connect> mode. 437C<accept>, and for the TLS client side of a connection, use C<connect>
438mode.
180 439
181You can also provide your own TLS connection object, but you have 440You can also provide your own TLS connection object, but you have
182to make sure that you call either C<Net::SSLeay::set_connect_state> 441to make sure that you call either C<Net::SSLeay::set_connect_state>
183or C<Net::SSLeay::set_accept_state> on it before you pass it to 442or C<Net::SSLeay::set_accept_state> on it before you pass it to
184AnyEvent::Handle. 443AnyEvent::Handle. Also, this module will take ownership of this connection
444object.
185 445
446At some future point, AnyEvent::Handle might switch to another TLS
447implementation, then the option to use your own session object will go
448away.
449
450B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
451passing in the wrong integer will lead to certain crash. This most often
452happens when one uses a stylish C<< tls => 1 >> and is surprised about the
453segmentation fault.
454
186See the C<starttls> method if you need to start TLs negotiation later. 455Use the C<< ->starttls >> method if you need to start TLS negotiation later.
187 456
188=item tls_ctx => $ssl_ctx 457=item tls_ctx => $anyevent_tls
189 458
190Use the given Net::SSLeay::CTX object to create the new TLS connection 459Use the given C<AnyEvent::TLS> object to create the new TLS connection
191(unless a connection object was specified directly). If this parameter is 460(unless a connection object was specified directly). If this
192missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 461parameter is missing (or C<undef>), then AnyEvent::Handle will use
462C<AnyEvent::Handle::TLS_CTX>.
193 463
464Instead of an object, you can also specify a hash reference with C<< key
465=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
466new TLS context object.
467
468=item on_starttls => $cb->($handle, $success[, $error_message])
469
470This callback will be invoked when the TLS/SSL handshake has finished. If
471C<$success> is true, then the TLS handshake succeeded, otherwise it failed
472(C<on_stoptls> will not be called in this case).
473
474The session in C<< $handle->{tls} >> can still be examined in this
475callback, even when the handshake was not successful.
476
477TLS handshake failures will not cause C<on_error> to be invoked when this
478callback is in effect, instead, the error message will be passed to C<on_starttls>.
479
480Without this callback, handshake failures lead to C<on_error> being
481called as usual.
482
483Note that you cannot just call C<starttls> again in this callback. If you
484need to do that, start an zero-second timer instead whose callback can
485then call C<< ->starttls >> again.
486
487=item on_stoptls => $cb->($handle)
488
489When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
490set, then it will be invoked after freeing the TLS session. If it is not,
491then a TLS shutdown condition will be treated like a normal EOF condition
492on the handle.
493
494The session in C<< $handle->{tls} >> can still be examined in this
495callback.
496
497This callback will only be called on TLS shutdowns, not when the
498underlying handle signals EOF.
499
194=item json => JSON or JSON::XS object 500=item json => L<JSON>, L<JSON::PP> or L<JSON::XS> object
195 501
196This is the json coder object used by the C<json> read and write types. 502This is the json coder object used by the C<json> read and write types.
197 503
198If you don't supply it, then AnyEvent::Handle will create and use a 504If you don't supply it, then AnyEvent::Handle will create and use a
199suitable one, which will write and expect UTF-8 encoded JSON texts. 505suitable one (on demand), which will write and expect UTF-8 encoded
506JSON texts (either using L<JSON::XS> or L<JSON>). The written texts are
507guaranteed not to contain any newline character.
200 508
509For security reasons, this encoder will likely I<not> handle numbers and
510strings, only arrays and objects/hashes. The reason is that originally
511JSON was self-delimited, but Dougles Crockford thought it was a splendid
512idea to redefine JSON incompatibly, so this is no longer true.
513
514For protocols that used back-to-back JSON texts, this might lead to
515run-ins, where two or more JSON texts will be interpreted as one JSON
516text.
517
518For this reason, if the default encoder uses L<JSON::XS>, it will default
519to not allowing anything but arrays and objects/hashes, at least for the
520forseeable future (it will change at some point). This might or might not
521be true for the L<JSON> module, so this might cause a security issue.
522
523If you depend on either behaviour, you should create your own json object
524and pass it in explicitly.
525
526=item cbor => L<CBOR::XS> object
527
528This is the cbor coder object used by the C<cbor> read and write types.
529
530If you don't supply it, then AnyEvent::Handle will create and use a
531suitable one (on demand), which will write CBOR without using extensions,
532if possible.
533
201Note that you are responsible to depend on the JSON module if you want to 534Note that you are responsible to depend on the L<CBOR::XS> module if you
202use this functionality, as AnyEvent does not have a dependency itself. 535want to use this functionality, as AnyEvent does not have a dependency on
203 536it itself.
204=item filter_r => $cb
205
206=item filter_w => $cb
207
208These exist, but are undocumented at this time.
209 537
210=back 538=back
211 539
212=cut 540=cut
213 541
214sub new { 542sub new {
215 my $class = shift; 543 my $class = shift;
216
217 my $self = bless { @_ }, $class; 544 my $self = bless { @_ }, $class;
218 545
219 $self->{fh} or Carp::croak "mandatory argument fh is missing";
220
221 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
222
223 if ($self->{tls}) { 546 if ($self->{fh}) {
224 require Net::SSLeay;
225 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
226 }
227
228# $self->on_eof (delete $self->{on_eof} ) if $self->{on_eof}; # nop
229# $self->on_error (delete $self->{on_error}) if $self->{on_error}; # nop
230# $self->on_read (delete $self->{on_read} ) if $self->{on_read}; # nop
231 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain};
232
233 $self->{_activity} = time;
234 $self->_timeout;
235
236 $self->start_read; 547 $self->_start;
548 return unless $self->{fh}; # could be gone by now
549
550 } elsif ($self->{connect}) {
551 require AnyEvent::Socket;
552
553 $self->{peername} = $self->{connect}[0]
554 unless exists $self->{peername};
555
556 $self->{_skip_drain_rbuf} = 1;
557
558 {
559 Scalar::Util::weaken (my $self = $self);
560
561 $self->{_connect} =
562 AnyEvent::Socket::tcp_connect (
563 $self->{connect}[0],
564 $self->{connect}[1],
565 sub {
566 my ($fh, $host, $port, $retry) = @_;
567
568 delete $self->{_connect}; # no longer needed
569
570 if ($fh) {
571 $self->{fh} = $fh;
572
573 delete $self->{_skip_drain_rbuf};
574 $self->_start;
575
576 $self->{on_connect}
577 and $self->{on_connect}($self, $host, $port, sub {
578 delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
579 $self->{_skip_drain_rbuf} = 1;
580 &$retry;
581 });
582
583 } else {
584 if ($self->{on_connect_error}) {
585 $self->{on_connect_error}($self, "$!");
586 $self->destroy if $self;
587 } else {
588 $self->_error ($!, 1);
589 }
590 }
591 },
592 sub {
593 local $self->{fh} = $_[0];
594
595 $self->{on_prepare}
596 ? $self->{on_prepare}->($self)
597 : ()
598 }
599 );
600 }
601
602 } else {
603 Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
604 }
237 605
238 $self 606 $self
239} 607}
240 608
241sub _shutdown { 609sub _start {
242 my ($self) = @_; 610 my ($self) = @_;
243 611
244 delete $self->{_rw}; 612 # too many clueless people try to use udp and similar sockets
245 delete $self->{_ww}; 613 # with AnyEvent::Handle, do them a favour.
246 delete $self->{fh}; 614 my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
247} 615 Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
616 if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
248 617
618 AnyEvent::fh_unblock $self->{fh};
619
620 $self->{_activity} =
621 $self->{_ractivity} =
622 $self->{_wactivity} = AE::now;
623
624 $self->{read_size} ||= 2048;
625 $self->{max_read_size} = $self->{read_size}
626 if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
627
628 $self->timeout (delete $self->{timeout} ) if $self->{timeout};
629 $self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
630 $self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
631
632 $self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
633 $self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
634
635 $self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
636
637 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
638 if $self->{tls};
639
640 $self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
641
642 $self->start_read
643 if $self->{on_read} || @{ $self->{_queue} };
644
645 $self->_drain_wbuf;
646}
647
249sub error { 648sub _error {
250 my ($self) = @_; 649 my ($self, $errno, $fatal, $message) = @_;
251 650
252 { 651 $! = $errno;
253 local $!; 652 $message ||= "$!";
254 $self->_shutdown;
255 }
256 653
257 $self->{on_error}($self)
258 if $self->{on_error}; 654 if ($self->{on_error}) {
259 655 $self->{on_error}($self, $fatal, $message);
656 $self->destroy if $fatal;
657 } elsif ($self->{fh} || $self->{connect}) {
658 $self->destroy;
260 Carp::croak "AnyEvent::Handle uncaught fatal error: $!"; 659 Carp::croak "AnyEvent::Handle uncaught error: $message";
660 }
261} 661}
262 662
263=item $fh = $handle->fh 663=item $fh = $handle->fh
264 664
265This method returns the file handle of the L<AnyEvent::Handle> object. 665This method returns the file handle used to create the L<AnyEvent::Handle> object.
266 666
267=cut 667=cut
268 668
269sub fh { $_[0]{fh} } 669sub fh { $_[0]{fh} }
270 670
288 $_[0]{on_eof} = $_[1]; 688 $_[0]{on_eof} = $_[1];
289} 689}
290 690
291=item $handle->on_timeout ($cb) 691=item $handle->on_timeout ($cb)
292 692
293Replace the current C<on_timeout> callback, or disables the callback 693=item $handle->on_rtimeout ($cb)
294(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor
295argument.
296 694
297=cut 695=item $handle->on_wtimeout ($cb)
298 696
697Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
698callback, or disables the callback (but not the timeout) if C<$cb> =
699C<undef>. See the C<timeout> constructor argument and method.
700
701=cut
702
703# see below
704
705=item $handle->autocork ($boolean)
706
707Enables or disables the current autocork behaviour (see C<autocork>
708constructor argument). Changes will only take effect on the next write.
709
710=cut
711
712sub autocork {
713 $_[0]{autocork} = $_[1];
714}
715
716=item $handle->no_delay ($boolean)
717
718Enables or disables the C<no_delay> setting (see constructor argument of
719the same name for details).
720
721=cut
722
723sub no_delay {
724 $_[0]{no_delay} = $_[1];
725
726 setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
727 if $_[0]{fh};
728}
729
730=item $handle->keepalive ($boolean)
731
732Enables or disables the C<keepalive> setting (see constructor argument of
733the same name for details).
734
735=cut
736
737sub keepalive {
738 $_[0]{keepalive} = $_[1];
739
740 eval {
741 local $SIG{__DIE__};
742 setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
743 if $_[0]{fh};
744 };
745}
746
747=item $handle->oobinline ($boolean)
748
749Enables or disables the C<oobinline> setting (see constructor argument of
750the same name for details).
751
752=cut
753
754sub oobinline {
755 $_[0]{oobinline} = $_[1];
756
757 eval {
758 local $SIG{__DIE__};
759 setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
760 if $_[0]{fh};
761 };
762}
763
764=item $handle->on_starttls ($cb)
765
766Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
767
768=cut
769
770sub on_starttls {
771 $_[0]{on_starttls} = $_[1];
772}
773
774=item $handle->on_stoptls ($cb)
775
776Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
777
778=cut
779
299sub on_timeout { 780sub on_stoptls {
300 $_[0]{on_timeout} = $_[1]; 781 $_[0]{on_stoptls} = $_[1];
782}
783
784=item $handle->rbuf_max ($max_octets)
785
786Configures the C<rbuf_max> setting (C<undef> disables it).
787
788=item $handle->wbuf_max ($max_octets)
789
790Configures the C<wbuf_max> setting (C<undef> disables it).
791
792=cut
793
794sub rbuf_max {
795 $_[0]{rbuf_max} = $_[1];
796}
797
798sub wbuf_max {
799 $_[0]{wbuf_max} = $_[1];
301} 800}
302 801
303############################################################################# 802#############################################################################
304 803
305=item $handle->timeout ($seconds) 804=item $handle->timeout ($seconds)
306 805
806=item $handle->rtimeout ($seconds)
807
808=item $handle->wtimeout ($seconds)
809
307Configures (or disables) the inactivity timeout. 810Configures (or disables) the inactivity timeout.
308 811
309=cut 812The timeout will be checked instantly, so this method might destroy the
813handle before it returns.
310 814
311sub timeout { 815=item $handle->timeout_reset
816
817=item $handle->rtimeout_reset
818
819=item $handle->wtimeout_reset
820
821Reset the activity timeout, as if data was received or sent.
822
823These methods are cheap to call.
824
825=cut
826
827for my $dir ("", "r", "w") {
828 my $timeout = "${dir}timeout";
829 my $tw = "_${dir}tw";
830 my $on_timeout = "on_${dir}timeout";
831 my $activity = "_${dir}activity";
832 my $cb;
833
834 *$on_timeout = sub {
835 $_[0]{$on_timeout} = $_[1];
836 };
837
838 *$timeout = sub {
312 my ($self, $timeout) = @_; 839 my ($self, $new_value) = @_;
313 840
841 $new_value >= 0
842 or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
843
314 $self->{timeout} = $timeout; 844 $self->{$timeout} = $new_value;
315 $self->_timeout; 845 delete $self->{$tw}; &$cb;
316} 846 };
317 847
848 *{"${dir}timeout_reset"} = sub {
849 $_[0]{$activity} = AE::now;
850 };
851
852 # main workhorse:
318# reset the timeout watcher, as neccessary 853 # reset the timeout watcher, as neccessary
319# also check for time-outs 854 # also check for time-outs
320sub _timeout { 855 $cb = sub {
321 my ($self) = @_; 856 my ($self) = @_;
322 857
323 if ($self->{timeout}) { 858 if ($self->{$timeout} && $self->{fh}) {
324 my $NOW = time; 859 my $NOW = AE::now;
325 860
326 # when would the timeout trigger? 861 # when would the timeout trigger?
327 my $after = $self->{_activity} + $self->{timeout} - $NOW; 862 my $after = $self->{$activity} + $self->{$timeout} - $NOW;
328 863
329 warn "next to in $after\n";#d#
330
331 # now or in the past already? 864 # now or in the past already?
332 if ($after <= 0) { 865 if ($after <= 0) {
333 $self->{_activity} = $NOW; 866 $self->{$activity} = $NOW;
334 867
335 if ($self->{on_timeout}) { 868 if ($self->{$on_timeout}) {
336 $self->{on_timeout}->($self); 869 $self->{$on_timeout}($self);
337 } else { 870 } else {
338 $! = Errno::ETIMEDOUT; 871 $self->_error (Errno::ETIMEDOUT);
339 $self->error; 872 }
873
874 # callback could have changed timeout value, optimise
875 return unless $self->{$timeout};
876
877 # calculate new after
878 $after = $self->{$timeout};
340 } 879 }
341 880
342 # callbakx could have changed timeout value, optimise 881 Scalar::Util::weaken $self;
343 return unless $self->{timeout}; 882 return unless $self; # ->error could have destroyed $self
344 883
345 # calculate new after 884 $self->{$tw} ||= AE::timer $after, 0, sub {
346 $after = $self->{timeout}; 885 delete $self->{$tw};
886 $cb->($self);
887 };
888 } else {
889 delete $self->{$tw};
347 } 890 }
348
349 Scalar::Util::weaken $self;
350
351 warn "after $after\n";#d#
352 $self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
353 delete $self->{_tw};
354 $self->_timeout;
355 });
356 } else {
357 delete $self->{_tw};
358 } 891 }
359} 892}
360 893
361############################################################################# 894#############################################################################
362 895
369 902
370The write queue is very simple: you can add data to its end, and 903The write queue is very simple: you can add data to its end, and
371AnyEvent::Handle will automatically try to get rid of it for you. 904AnyEvent::Handle will automatically try to get rid of it for you.
372 905
373When data could be written and the write buffer is shorter then the low 906When data could be written and the write buffer is shorter then the low
374water mark, the C<on_drain> callback will be invoked. 907water mark, the C<on_drain> callback will be invoked once.
375 908
376=over 4 909=over 4
377 910
378=item $handle->on_drain ($cb) 911=item $handle->on_drain ($cb)
379 912
380Sets the C<on_drain> callback or clears it (see the description of 913Sets the C<on_drain> callback or clears it (see the description of
381C<on_drain> in the constructor). 914C<on_drain> in the constructor).
382 915
916This method may invoke callbacks (and therefore the handle might be
917destroyed after it returns).
918
383=cut 919=cut
384 920
385sub on_drain { 921sub on_drain {
386 my ($self, $cb) = @_; 922 my ($self, $cb) = @_;
387 923
388 $self->{on_drain} = $cb; 924 $self->{on_drain} = $cb;
389 925
390 $cb->($self) 926 $cb->($self)
391 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 927 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
392} 928}
393 929
394=item $handle->push_write ($data) 930=item $handle->push_write ($data)
395 931
396Queues the given scalar to be written. You can push as much data as you 932Queues the given scalar to be written. You can push as much data as
397want (only limited by the available memory), as C<AnyEvent::Handle> 933you want (only limited by the available memory and C<wbuf_max>), as
398buffers it independently of the kernel. 934C<AnyEvent::Handle> buffers it independently of the kernel.
935
936This method may invoke callbacks (and therefore the handle might be
937destroyed after it returns).
399 938
400=cut 939=cut
401 940
402sub _drain_wbuf { 941sub _drain_wbuf {
403 my ($self) = @_; 942 my ($self) = @_;
407 Scalar::Util::weaken $self; 946 Scalar::Util::weaken $self;
408 947
409 my $cb = sub { 948 my $cb = sub {
410 my $len = syswrite $self->{fh}, $self->{wbuf}; 949 my $len = syswrite $self->{fh}, $self->{wbuf};
411 950
412 if ($len >= 0) { 951 if (defined $len) {
413 substr $self->{wbuf}, 0, $len, ""; 952 substr $self->{wbuf}, 0, $len, "";
414 953
415 $self->{_activity} = time; 954 $self->{_activity} = $self->{_wactivity} = AE::now;
416 955
417 $self->{on_drain}($self) 956 $self->{on_drain}($self)
418 if $self->{low_water_mark} >= length $self->{wbuf} 957 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
419 && $self->{on_drain}; 958 && $self->{on_drain};
420 959
421 delete $self->{_ww} unless length $self->{wbuf}; 960 delete $self->{_ww} unless length $self->{wbuf};
422 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { 961 } elsif ($! != EAGAIN && $! != EINTR && $! != EWOULDBLOCK && $! != WSAEWOULDBLOCK) {
423 $self->error; 962 $self->_error ($!, 1);
424 } 963 }
425 }; 964 };
426 965
427 # try to write data immediately 966 # try to write data immediately
428 $cb->(); 967 $cb->() unless $self->{autocork};
429 968
430 # if still data left in wbuf, we need to poll 969 # if still data left in wbuf, we need to poll
431 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb) 970 $self->{_ww} = AE::io $self->{fh}, 1, $cb
432 if length $self->{wbuf}; 971 if length $self->{wbuf};
972
973 if (
974 defined $self->{wbuf_max}
975 && $self->{wbuf_max} < length $self->{wbuf}
976 ) {
977 $self->_error (Errno::ENOSPC, 1), return;
978 }
433 }; 979 };
434} 980}
435 981
436our %WH; 982our %WH;
437 983
984# deprecated
438sub register_write_type($$) { 985sub register_write_type($$) {
439 $WH{$_[0]} = $_[1]; 986 $WH{$_[0]} = $_[1];
440} 987}
441 988
442sub push_write { 989sub push_write {
443 my $self = shift; 990 my $self = shift;
444 991
445 if (@_ > 1) { 992 if (@_ > 1) {
446 my $type = shift; 993 my $type = shift;
447 994
995 @_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
448 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 996 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
449 ->($self, @_); 997 ->($self, @_);
450 } 998 }
451 999
1000 # we downgrade here to avoid hard-to-track-down bugs,
1001 # and diagnose the problem earlier and better.
1002
452 if ($self->{filter_w}) { 1003 if ($self->{tls}) {
453 $self->{filter_w}->($self, \$_[0]); 1004 utf8::downgrade $self->{_tls_wbuf} .= $_[0];
1005 &_dotls ($self) if $self->{fh};
454 } else { 1006 } else {
455 $self->{wbuf} .= $_[0]; 1007 utf8::downgrade $self->{wbuf} .= $_[0];
456 $self->_drain_wbuf; 1008 $self->_drain_wbuf if $self->{fh};
457 } 1009 }
458} 1010}
459 1011
460=item $handle->push_write (type => @args) 1012=item $handle->push_write (type => @args)
461 1013
462=item $handle->unshift_write (type => @args)
463
464Instead of formatting your data yourself, you can also let this module do 1014Instead of formatting your data yourself, you can also let this module
465the job by specifying a type and type-specific arguments. 1015do the job by specifying a type and type-specific arguments. You
1016can also specify the (fully qualified) name of a package, in which
1017case AnyEvent tries to load the package and then expects to find the
1018C<anyevent_write_type> function inside (see "custom write types", below).
466 1019
467Predefined types are (if you have ideas for additional types, feel free to 1020Predefined types are (if you have ideas for additional types, feel free to
468drop by and tell us): 1021drop by and tell us):
469 1022
470=over 4 1023=over 4
472=item netstring => $string 1025=item netstring => $string
473 1026
474Formats the given value as netstring 1027Formats the given value as netstring
475(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them). 1028(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
476 1029
477=back
478
479=cut 1030=cut
480 1031
481register_write_type netstring => sub { 1032register_write_type netstring => sub {
482 my ($self, $string) = @_; 1033 my ($self, $string) = @_;
483 1034
484 sprintf "%d:%s,", (length $string), $string 1035 (length $string) . ":$string,"
1036};
1037
1038=item packstring => $format, $data
1039
1040An octet string prefixed with an encoded length. The encoding C<$format>
1041uses the same format as a Perl C<pack> format, but must specify a single
1042integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1043optional C<!>, C<< < >> or C<< > >> modifier).
1044
1045=cut
1046
1047register_write_type packstring => sub {
1048 my ($self, $format, $string) = @_;
1049
1050 pack "$format/a*", $string
485}; 1051};
486 1052
487=item json => $array_or_hashref 1053=item json => $array_or_hashref
488 1054
489Encodes the given hash or array reference into a JSON object. Unless you 1055Encodes the given hash or array reference into a JSON object. Unless you
490provide your own JSON object, this means it will be encoded to JSON text 1056provide your own JSON object, this means it will be encoded to JSON text
491in UTF-8. 1057in UTF-8.
492 1058
1059The default encoder might or might not handle every type of JSON value -
1060it might be limited to arrays and objects for security reasons. See the
1061C<json> constructor attribute for more details.
1062
493JSON objects (and arrays) are self-delimiting, so you can write JSON at 1063JSON objects (and arrays) are self-delimiting, so if you only use arrays
494one end of a handle and read them at the other end without using any 1064and hashes, you can write JSON at one end of a handle and read them at the
495additional framing. 1065other end without using any additional framing.
496 1066
497The generated JSON text is guaranteed not to contain any newlines: While 1067The JSON text generated by the default encoder is guaranteed not to
498this module doesn't need delimiters after or between JSON texts to be 1068contain any newlines: While this module doesn't need delimiters after or
499able to read them, many other languages depend on that. 1069between JSON texts to be able to read them, many other languages depend on
1070them.
500 1071
501A simple RPC protocol that interoperates easily with others is to send 1072A simple RPC protocol that interoperates easily with other languages is
502JSON arrays (or objects, although arrays are usually the better choice as 1073to send JSON arrays (or objects, although arrays are usually the better
503they mimic how function argument passing works) and a newline after each 1074choice as they mimic how function argument passing works) and a newline
504JSON text: 1075after each JSON text:
505 1076
506 $handle->push_write (json => ["method", "arg1", "arg2"]); # whatever 1077 $handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
507 $handle->push_write ("\012"); 1078 $handle->push_write ("\012");
508 1079
509An AnyEvent::Handle receiver would simply use the C<json> read type and 1080An AnyEvent::Handle receiver would simply use the C<json> read type and
512 $handle->push_read (json => sub { my $array = $_[1]; ... }); 1083 $handle->push_read (json => sub { my $array = $_[1]; ... });
513 1084
514Other languages could read single lines terminated by a newline and pass 1085Other languages could read single lines terminated by a newline and pass
515this line into their JSON decoder of choice. 1086this line into their JSON decoder of choice.
516 1087
1088=item cbor => $perl_scalar
1089
1090Encodes the given scalar into a CBOR value. Unless you provide your own
1091L<CBOR::XS> object, this means it will be encoded to a CBOR string not
1092using any extensions, if possible.
1093
1094CBOR values are self-delimiting, so you can write CBOR at one end of
1095a handle and read them at the other end without using any additional
1096framing.
1097
1098A simple nd very very fast RPC protocol that interoperates with
1099other languages is to send CBOR and receive CBOR values (arrays are
1100recommended):
1101
1102 $handle->push_write (cbor => ["method", "arg1", "arg2"]); # whatever
1103
1104An AnyEvent::Handle receiver would simply use the C<cbor> read type:
1105
1106 $handle->push_read (cbor => sub { my $array = $_[1]; ... });
1107
517=cut 1108=cut
1109
1110sub json_coder() {
1111 eval { require JSON::XS; JSON::XS->new->utf8 }
1112 || do { require JSON::PP; JSON::PP->new->utf8 }
1113}
518 1114
519register_write_type json => sub { 1115register_write_type json => sub {
520 my ($self, $ref) = @_; 1116 my ($self, $ref) = @_;
521 1117
522 require JSON; 1118 ($self->{json} ||= json_coder)
523 1119 ->encode ($ref)
524 $self->{json} ? $self->{json}->encode ($ref)
525 : JSON::encode_json ($ref)
526}; 1120};
527 1121
528=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args) 1122sub cbor_coder() {
1123 require CBOR::XS;
1124 CBOR::XS->new
1125}
529 1126
530This function (not method) lets you add your own types to C<push_write>. 1127register_write_type cbor => sub {
1128 my ($self, $scalar) = @_;
1129
1130 ($self->{cbor} ||= cbor_coder)
1131 ->encode ($scalar)
1132};
1133
1134=item storable => $reference
1135
1136Freezes the given reference using L<Storable> and writes it to the
1137handle. Uses the C<nfreeze> format.
1138
1139=cut
1140
1141register_write_type storable => sub {
1142 my ($self, $ref) = @_;
1143
1144 require Storable unless $Storable::VERSION;
1145
1146 pack "w/a*", Storable::nfreeze ($ref)
1147};
1148
1149=back
1150
1151=item $handle->push_shutdown
1152
1153Sometimes you know you want to close the socket after writing your data
1154before it was actually written. One way to do that is to replace your
1155C<on_drain> handler by a callback that shuts down the socket (and set
1156C<low_water_mark> to C<0>). This method is a shorthand for just that, and
1157replaces the C<on_drain> callback with:
1158
1159 sub { shutdown $_[0]{fh}, 1 }
1160
1161This simply shuts down the write side and signals an EOF condition to the
1162the peer.
1163
1164You can rely on the normal read queue and C<on_eof> handling
1165afterwards. This is the cleanest way to close a connection.
1166
1167This method may invoke callbacks (and therefore the handle might be
1168destroyed after it returns).
1169
1170=cut
1171
1172sub push_shutdown {
1173 my ($self) = @_;
1174
1175 delete $self->{low_water_mark};
1176 $self->on_drain (sub { shutdown $_[0]{fh}, 1 });
1177}
1178
1179=item custom write types - Package::anyevent_write_type $handle, @args
1180
1181Instead of one of the predefined types, you can also specify the name of
1182a package. AnyEvent will try to load the package and then expects to find
1183a function named C<anyevent_write_type> inside. If it isn't found, it
1184progressively tries to load the parent package until it either finds the
1185function (good) or runs out of packages (bad).
1186
531Whenever the given C<type> is used, C<push_write> will invoke the code 1187Whenever the given C<type> is used, C<push_write> will the function with
532reference with the handle object and the remaining arguments. 1188the handle object and the remaining arguments.
533 1189
534The code reference is supposed to return a single octet string that will 1190The function is supposed to return a single octet string that will be
535be appended to the write buffer. 1191appended to the write buffer, so you can mentally treat this function as a
1192"arguments to on-the-wire-format" converter.
536 1193
537Note that this is a function, and all types registered this way will be 1194Example: implement a custom write type C<join> that joins the remaining
538global, so try to use unique names. 1195arguments using the first one.
1196
1197 $handle->push_write (My::Type => " ", 1,2,3);
1198
1199 # uses the following package, which can be defined in the "My::Type" or in
1200 # the "My" modules to be auto-loaded, or just about anywhere when the
1201 # My::Type::anyevent_write_type is defined before invoking it.
1202
1203 package My::Type;
1204
1205 sub anyevent_write_type {
1206 my ($handle, $delim, @args) = @_;
1207
1208 join $delim, @args
1209 }
539 1210
540=cut 1211=cut
541 1212
542############################################################################# 1213#############################################################################
543 1214
552ways, the "simple" way, using only C<on_read> and the "complex" way, using 1223ways, the "simple" way, using only C<on_read> and the "complex" way, using
553a queue. 1224a queue.
554 1225
555In the simple case, you just install an C<on_read> callback and whenever 1226In the simple case, you just install an C<on_read> callback and whenever
556new data arrives, it will be called. You can then remove some data (if 1227new data arrives, it will be called. You can then remove some data (if
557enough is there) from the read buffer (C<< $handle->rbuf >>) if you want 1228enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
558or not. 1229leave the data there if you want to accumulate more (e.g. when only a
1230partial message has been received so far), or change the read queue with
1231e.g. C<push_read>.
559 1232
560In the more complex case, you want to queue multiple callbacks. In this 1233In the more complex case, you want to queue multiple callbacks. In this
561case, AnyEvent::Handle will call the first queued callback each time new 1234case, AnyEvent::Handle will call the first queued callback each time new
562data arrives and removes it when it has done its job (see C<push_read>, 1235data arrives (also the first time it is queued) and remove it when it has
563below). 1236done its job (see C<push_read>, below).
564 1237
565This way you can, for example, push three line-reads, followed by reading 1238This way you can, for example, push three line-reads, followed by reading
566a chunk of data, and AnyEvent::Handle will execute them in order. 1239a chunk of data, and AnyEvent::Handle will execute them in order.
567 1240
568Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by 1241Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
569the specified number of bytes which give an XML datagram. 1242the specified number of bytes which give an XML datagram.
570 1243
571 # in the default state, expect some header bytes 1244 # in the default state, expect some header bytes
572 $handle->on_read (sub { 1245 $handle->on_read (sub {
573 # some data is here, now queue the length-header-read (4 octets) 1246 # some data is here, now queue the length-header-read (4 octets)
574 shift->unshift_read_chunk (4, sub { 1247 shift->unshift_read (chunk => 4, sub {
575 # header arrived, decode 1248 # header arrived, decode
576 my $len = unpack "N", $_[1]; 1249 my $len = unpack "N", $_[1];
577 1250
578 # now read the payload 1251 # now read the payload
579 shift->unshift_read_chunk ($len, sub { 1252 shift->unshift_read (chunk => $len, sub {
580 my $xml = $_[1]; 1253 my $xml = $_[1];
581 # handle xml 1254 # handle xml
582 }); 1255 });
583 }); 1256 });
584 }); 1257 });
585 1258
586Example 2: Implement a client for a protocol that replies either with 1259Example 2: Implement a client for a protocol that replies either with "OK"
587"OK" and another line or "ERROR" for one request, and 64 bytes for the 1260and another line or "ERROR" for the first request that is sent, and 64
588second request. Due tot he availability of a full queue, we can just 1261bytes for the second request. Due to the availability of a queue, we can
589pipeline sending both requests and manipulate the queue as necessary in 1262just pipeline sending both requests and manipulate the queue as necessary
590the callbacks: 1263in the callbacks.
591 1264
592 # request one 1265When the first callback is called and sees an "OK" response, it will
1266C<unshift> another line-read. This line-read will be queued I<before> the
126764-byte chunk callback.
1268
1269 # request one, returns either "OK + extra line" or "ERROR"
593 $handle->push_write ("request 1\015\012"); 1270 $handle->push_write ("request 1\015\012");
594 1271
595 # we expect "ERROR" or "OK" as response, so push a line read 1272 # we expect "ERROR" or "OK" as response, so push a line read
596 $handle->push_read_line (sub { 1273 $handle->push_read (line => sub {
597 # if we got an "OK", we have to _prepend_ another line, 1274 # if we got an "OK", we have to _prepend_ another line,
598 # so it will be read before the second request reads its 64 bytes 1275 # so it will be read before the second request reads its 64 bytes
599 # which are already in the queue when this callback is called 1276 # which are already in the queue when this callback is called
600 # we don't do this in case we got an error 1277 # we don't do this in case we got an error
601 if ($_[1] eq "OK") { 1278 if ($_[1] eq "OK") {
602 $_[0]->unshift_read_line (sub { 1279 $_[0]->unshift_read (line => sub {
603 my $response = $_[1]; 1280 my $response = $_[1];
604 ... 1281 ...
605 }); 1282 });
606 } 1283 }
607 }); 1284 });
608 1285
609 # request two 1286 # request two, simply returns 64 octets
610 $handle->push_write ("request 2\015\012"); 1287 $handle->push_write ("request 2\015\012");
611 1288
612 # simply read 64 bytes, always 1289 # simply read 64 bytes, always
613 $handle->push_read_chunk (64, sub { 1290 $handle->push_read (chunk => 64, sub {
614 my $response = $_[1]; 1291 my $response = $_[1];
615 ... 1292 ...
616 }); 1293 });
617 1294
618=over 4 1295=over 4
619 1296
620=cut 1297=cut
621 1298
622sub _drain_rbuf { 1299sub _drain_rbuf {
623 my ($self) = @_; 1300 my ($self) = @_;
1301
1302 # avoid recursion
1303 return if $self->{_skip_drain_rbuf};
1304 local $self->{_skip_drain_rbuf} = 1;
1305
1306 while () {
1307 # we need to use a separate tls read buffer, as we must not receive data while
1308 # we are draining the buffer, and this can only happen with TLS.
1309 $self->{rbuf} .= delete $self->{_tls_rbuf}
1310 if exists $self->{_tls_rbuf};
1311
1312 my $len = length $self->{rbuf};
1313
1314 if (my $cb = shift @{ $self->{_queue} }) {
1315 unless ($cb->($self)) {
1316 # no progress can be made
1317 # (not enough data and no data forthcoming)
1318 $self->_error (Errno::EPIPE, 1), return
1319 if $self->{_eof};
1320
1321 unshift @{ $self->{_queue} }, $cb;
1322 last;
1323 }
1324 } elsif ($self->{on_read}) {
1325 last unless $len;
1326
1327 $self->{on_read}($self);
1328
1329 if (
1330 $len == length $self->{rbuf} # if no data has been consumed
1331 && !@{ $self->{_queue} } # and the queue is still empty
1332 && $self->{on_read} # but we still have on_read
1333 ) {
1334 # no further data will arrive
1335 # so no progress can be made
1336 $self->_error (Errno::EPIPE, 1), return
1337 if $self->{_eof};
1338
1339 last; # more data might arrive
1340 }
1341 } else {
1342 # read side becomes idle
1343 delete $self->{_rw} unless $self->{tls};
1344 last;
1345 }
1346 }
1347
1348 if ($self->{_eof}) {
1349 $self->{on_eof}
1350 ? $self->{on_eof}($self)
1351 : $self->_error (0, 1, "Unexpected end-of-file");
1352
1353 return;
1354 }
624 1355
625 if ( 1356 if (
626 defined $self->{rbuf_max} 1357 defined $self->{rbuf_max}
627 && $self->{rbuf_max} < length $self->{rbuf} 1358 && $self->{rbuf_max} < length $self->{rbuf}
628 ) { 1359 ) {
629 $! = &Errno::ENOSPC; 1360 $self->_error (Errno::ENOSPC, 1), return;
630 $self->error;
631 } 1361 }
632 1362
633 return if $self->{in_drain}; 1363 # may need to restart read watcher
634 local $self->{in_drain} = 1; 1364 unless ($self->{_rw}) {
635 1365 $self->start_read
636 while (my $len = length $self->{rbuf}) { 1366 if $self->{on_read} || @{ $self->{_queue} };
637 no strict 'refs';
638 if (my $cb = shift @{ $self->{_queue} }) {
639 unless ($cb->($self)) {
640 if ($self->{_eof}) {
641 # no progress can be made (not enough data and no data forthcoming)
642 $! = &Errno::EPIPE;
643 $self->error;
644 }
645
646 unshift @{ $self->{_queue} }, $cb;
647 return;
648 }
649 } elsif ($self->{on_read}) {
650 $self->{on_read}($self);
651
652 if (
653 $self->{_eof} # if no further data will arrive
654 && $len == length $self->{rbuf} # and no data has been consumed
655 && !@{ $self->{_queue} } # and the queue is still empty
656 && $self->{on_read} # and we still want to read data
657 ) {
658 # then no progress can be made
659 $! = &Errno::EPIPE;
660 $self->error;
661 }
662 } else {
663 # read side becomes idle
664 delete $self->{_rw};
665 return;
666 }
667 }
668
669 if ($self->{_eof}) {
670 $self->_shutdown;
671 $self->{on_eof}($self)
672 if $self->{on_eof};
673 } 1367 }
674} 1368}
675 1369
676=item $handle->on_read ($cb) 1370=item $handle->on_read ($cb)
677 1371
678This replaces the currently set C<on_read> callback, or clears it (when 1372This replaces the currently set C<on_read> callback, or clears it (when
679the new callback is C<undef>). See the description of C<on_read> in the 1373the new callback is C<undef>). See the description of C<on_read> in the
680constructor. 1374constructor.
681 1375
1376This method may invoke callbacks (and therefore the handle might be
1377destroyed after it returns).
1378
682=cut 1379=cut
683 1380
684sub on_read { 1381sub on_read {
685 my ($self, $cb) = @_; 1382 my ($self, $cb) = @_;
686 1383
687 $self->{on_read} = $cb; 1384 $self->{on_read} = $cb;
1385 $self->_drain_rbuf if $cb;
688} 1386}
689 1387
690=item $handle->rbuf 1388=item $handle->rbuf
691 1389
692Returns the read buffer (as a modifiable lvalue). 1390Returns the read buffer (as a modifiable lvalue). You can also access the
1391read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
1392much faster, and no less clean).
693 1393
694You can access the read buffer directly as the C<< ->{rbuf} >> member, if 1394The only operation allowed on the read buffer (apart from looking at it)
695you want. 1395is removing data from its beginning. Otherwise modifying or appending to
1396it is not allowed and will lead to hard-to-track-down bugs.
696 1397
697NOTE: The read buffer should only be used or modified if the C<on_read>, 1398NOTE: The read buffer should only be used or modified in the C<on_read>
698C<push_read> or C<unshift_read> methods are used. The other read methods 1399callback or when C<push_read> or C<unshift_read> are used with a single
699automatically manage the read buffer. 1400callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
1401will manage the read buffer on their own.
700 1402
701=cut 1403=cut
702 1404
703sub rbuf : lvalue { 1405sub rbuf : lvalue {
704 $_[0]{rbuf} 1406 $_[0]{rbuf}
721 1423
722If enough data was available, then the callback must remove all data it is 1424If enough data was available, then the callback must remove all data it is
723interested in (which can be none at all) and return a true value. After returning 1425interested in (which can be none at all) and return a true value. After returning
724true, it will be removed from the queue. 1426true, it will be removed from the queue.
725 1427
1428These methods may invoke callbacks (and therefore the handle might be
1429destroyed after it returns).
1430
726=cut 1431=cut
727 1432
728our %RH; 1433our %RH;
729 1434
730sub register_read_type($$) { 1435sub register_read_type($$) {
736 my $cb = pop; 1441 my $cb = pop;
737 1442
738 if (@_) { 1443 if (@_) {
739 my $type = shift; 1444 my $type = shift;
740 1445
1446 $cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
741 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read") 1447 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
742 ->($self, $cb, @_); 1448 ->($self, $cb, @_);
743 } 1449 }
744 1450
745 push @{ $self->{_queue} }, $cb; 1451 push @{ $self->{_queue} }, $cb;
746 $self->_drain_rbuf; 1452 $self->_drain_rbuf;
751 my $cb = pop; 1457 my $cb = pop;
752 1458
753 if (@_) { 1459 if (@_) {
754 my $type = shift; 1460 my $type = shift;
755 1461
1462 $cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
756 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read") 1463 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
757 ->($self, $cb, @_); 1464 ->($self, $cb, @_);
758 } 1465 }
759
760 1466
761 unshift @{ $self->{_queue} }, $cb; 1467 unshift @{ $self->{_queue} }, $cb;
762 $self->_drain_rbuf; 1468 $self->_drain_rbuf;
763} 1469}
764 1470
766 1472
767=item $handle->unshift_read (type => @args, $cb) 1473=item $handle->unshift_read (type => @args, $cb)
768 1474
769Instead of providing a callback that parses the data itself you can chose 1475Instead of providing a callback that parses the data itself you can chose
770between a number of predefined parsing formats, for chunks of data, lines 1476between a number of predefined parsing formats, for chunks of data, lines
771etc. 1477etc. You can also specify the (fully qualified) name of a package, in
1478which case AnyEvent tries to load the package and then expects to find the
1479C<anyevent_read_type> function inside (see "custom read types", below).
772 1480
773Predefined types are (if you have ideas for additional types, feel free to 1481Predefined types are (if you have ideas for additional types, feel free to
774drop by and tell us): 1482drop by and tell us):
775 1483
776=over 4 1484=over 4
782data. 1490data.
783 1491
784Example: read 2 bytes. 1492Example: read 2 bytes.
785 1493
786 $handle->push_read (chunk => 2, sub { 1494 $handle->push_read (chunk => 2, sub {
787 warn "yay ", unpack "H*", $_[1]; 1495 say "yay " . unpack "H*", $_[1];
788 }); 1496 });
789 1497
790=cut 1498=cut
791 1499
792register_read_type chunk => sub { 1500register_read_type chunk => sub {
797 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); 1505 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
798 1 1506 1
799 } 1507 }
800}; 1508};
801 1509
802# compatibility with older API
803sub push_read_chunk {
804 $_[0]->push_read (chunk => $_[1], $_[2]);
805}
806
807sub unshift_read_chunk {
808 $_[0]->unshift_read (chunk => $_[1], $_[2]);
809}
810
811=item line => [$eol, ]$cb->($handle, $line, $eol) 1510=item line => [$eol, ]$cb->($handle, $line, $eol)
812 1511
813The callback will be called only once a full line (including the end of 1512The callback will be called only once a full line (including the end of
814line marker, C<$eol>) has been read. This line (excluding the end of line 1513line marker, C<$eol>) has been read. This line (excluding the end of line
815marker) will be passed to the callback as second argument (C<$line>), and 1514marker) will be passed to the callback as second argument (C<$line>), and
830=cut 1529=cut
831 1530
832register_read_type line => sub { 1531register_read_type line => sub {
833 my ($self, $cb, $eol) = @_; 1532 my ($self, $cb, $eol) = @_;
834 1533
835 $eol = qr|(\015?\012)| if @_ < 3; 1534 if (@_ < 3) {
1535 # this is faster then the generic code below
1536 sub {
1537 (my $pos = index $_[0]{rbuf}, "\012") >= 0
1538 or return;
1539
1540 (my $str = substr $_[0]{rbuf}, 0, $pos + 1, "") =~ s/(\015?\012)\Z// or die;
1541 $cb->($_[0], $str, "$1");
1542 1
1543 }
1544 } else {
836 $eol = quotemeta $eol unless ref $eol; 1545 $eol = quotemeta $eol unless ref $eol;
837 $eol = qr|^(.*?)($eol)|s; 1546 $eol = qr|^(.*?)($eol)|s;
838 1547
839 sub { 1548 sub {
840 $_[0]{rbuf} =~ s/$eol// or return; 1549 $_[0]{rbuf} =~ s/$eol// or return;
841 1550
842 $cb->($_[0], $1, $2); 1551 $cb->($_[0], "$1", "$2");
1552 1
843 1 1553 }
844 } 1554 }
845}; 1555};
846 1556
847# compatibility with older API
848sub push_read_line {
849 my $self = shift;
850 $self->push_read (line => @_);
851}
852
853sub unshift_read_line {
854 my $self = shift;
855 $self->unshift_read (line => @_);
856}
857
858=item netstring => $cb->($handle, $string)
859
860A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
861
862Throws an error with C<$!> set to EBADMSG on format violations.
863
864=cut
865
866register_read_type netstring => sub {
867 my ($self, $cb) = @_;
868
869 sub {
870 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
871 if ($_[0]{rbuf} =~ /[^0-9]/) {
872 $! = &Errno::EBADMSG;
873 $self->error;
874 }
875 return;
876 }
877
878 my $len = $1;
879
880 $self->unshift_read (chunk => $len, sub {
881 my $string = $_[1];
882 $_[0]->unshift_read (chunk => 1, sub {
883 if ($_[1] eq ",") {
884 $cb->($_[0], $string);
885 } else {
886 $! = &Errno::EBADMSG;
887 $self->error;
888 }
889 });
890 });
891
892 1
893 }
894};
895
896=item regex => $accept[, $reject[, $skip], $cb->($handle, $data) 1557=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
897 1558
898Makes a regex match against the regex object C<$accept> and returns 1559Makes a regex match against the regex object C<$accept> and returns
899everything up to and including the match. 1560everything up to and including the match. All the usual regex variables
1561($1, %+ etc.) from the regex match are available in the callback.
900 1562
901Example: read a single line terminated by '\n'. 1563Example: read a single line terminated by '\n'.
902 1564
903 $handle->push_read (regex => qr<\n>, sub { ... }); 1565 $handle->push_read (regex => qr<\n>, sub { ... });
904 1566
917the receive buffer when neither C<$accept> nor C<$reject> match, 1579the receive buffer when neither C<$accept> nor C<$reject> match,
918and everything preceding and including the match will be accepted 1580and everything preceding and including the match will be accepted
919unconditionally. This is useful to skip large amounts of data that you 1581unconditionally. This is useful to skip large amounts of data that you
920know cannot be matched, so that the C<$accept> or C<$reject> regex do not 1582know cannot be matched, so that the C<$accept> or C<$reject> regex do not
921have to start matching from the beginning. This is purely an optimisation 1583have to start matching from the beginning. This is purely an optimisation
922and is usually worth only when you expect more than a few kilobytes. 1584and is usually worth it only when you expect more than a few kilobytes.
923 1585
924Example: expect a http header, which ends at C<\015\012\015\012>. Since we 1586Example: expect a http header, which ends at C<\015\012\015\012>. Since we
925expect the header to be very large (it isn't in practise, but...), we use 1587expect the header to be very large (it isn't in practice, but...), we use
926a skip regex to skip initial portions. The skip regex is tricky in that 1588a skip regex to skip initial portions. The skip regex is tricky in that
927it only accepts something not ending in either \015 or \012, as these are 1589it only accepts something not ending in either \015 or \012, as these are
928required for the accept regex. 1590required for the accept regex.
929 1591
930 $handle->push_read (regex => 1592 $handle->push_read (regex =>
943 1605
944 sub { 1606 sub {
945 # accept 1607 # accept
946 if ($$rbuf =~ $accept) { 1608 if ($$rbuf =~ $accept) {
947 $data .= substr $$rbuf, 0, $+[0], ""; 1609 $data .= substr $$rbuf, 0, $+[0], "";
948 $cb->($self, $data); 1610 $cb->($_[0], $data);
949 return 1; 1611 return 1;
950 } 1612 }
951 1613
952 # reject 1614 # reject
953 if ($reject && $$rbuf =~ $reject) { 1615 if ($reject && $$rbuf =~ $reject) {
954 $! = &Errno::EBADMSG; 1616 $_[0]->_error (Errno::EBADMSG);
955 $self->error;
956 } 1617 }
957 1618
958 # skip 1619 # skip
959 if ($skip && $$rbuf =~ $skip) { 1620 if ($skip && $$rbuf =~ $skip) {
960 $data .= substr $$rbuf, 0, $+[0], ""; 1621 $data .= substr $$rbuf, 0, $+[0], "";
962 1623
963 () 1624 ()
964 } 1625 }
965}; 1626};
966 1627
1628=item netstring => $cb->($handle, $string)
1629
1630A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
1631
1632Throws an error with C<$!> set to EBADMSG on format violations.
1633
1634=cut
1635
1636register_read_type netstring => sub {
1637 my ($self, $cb) = @_;
1638
1639 sub {
1640 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1641 if ($_[0]{rbuf} =~ /[^0-9]/) {
1642 $_[0]->_error (Errno::EBADMSG);
1643 }
1644 return;
1645 }
1646
1647 my $len = $1;
1648
1649 $_[0]->unshift_read (chunk => $len, sub {
1650 my $string = $_[1];
1651 $_[0]->unshift_read (chunk => 1, sub {
1652 if ($_[1] eq ",") {
1653 $cb->($_[0], $string);
1654 } else {
1655 $_[0]->_error (Errno::EBADMSG);
1656 }
1657 });
1658 });
1659
1660 1
1661 }
1662};
1663
1664=item packstring => $format, $cb->($handle, $string)
1665
1666An octet string prefixed with an encoded length. The encoding C<$format>
1667uses the same format as a Perl C<pack> format, but must specify a single
1668integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1669optional C<!>, C<< < >> or C<< > >> modifier).
1670
1671For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1672EPP uses a prefix of C<N> (4 octtes).
1673
1674Example: read a block of data prefixed by its length in BER-encoded
1675format (very efficient).
1676
1677 $handle->push_read (packstring => "w", sub {
1678 my ($handle, $data) = @_;
1679 });
1680
1681=cut
1682
1683register_read_type packstring => sub {
1684 my ($self, $cb, $format) = @_;
1685
1686 sub {
1687 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1688 defined (my $len = eval { unpack $format, $_[0]{rbuf} })
1689 or return;
1690
1691 $format = length pack $format, $len;
1692
1693 # bypass unshift if we already have the remaining chunk
1694 if ($format + $len <= length $_[0]{rbuf}) {
1695 my $data = substr $_[0]{rbuf}, $format, $len;
1696 substr $_[0]{rbuf}, 0, $format + $len, "";
1697 $cb->($_[0], $data);
1698 } else {
1699 # remove prefix
1700 substr $_[0]{rbuf}, 0, $format, "";
1701
1702 # read remaining chunk
1703 $_[0]->unshift_read (chunk => $len, $cb);
1704 }
1705
1706 1
1707 }
1708};
1709
967=item json => $cb->($handle, $hash_or_arrayref) 1710=item json => $cb->($handle, $hash_or_arrayref)
968 1711
969Reads a JSON object or array, decodes it and passes it to the callback. 1712Reads a JSON object or array, decodes it and passes it to the
1713callback. When a parse error occurs, an C<EBADMSG> error will be raised.
970 1714
971If a C<json> object was passed to the constructor, then that will be used 1715If a C<json> object was passed to the constructor, then that will be
972for the final decode, otherwise it will create a JSON coder expecting UTF-8. 1716used for the final decode, otherwise it will create a L<JSON::XS> or
1717L<JSON::PP> coder object expecting UTF-8.
973 1718
974This read type uses the incremental parser available with JSON version 1719This read type uses the incremental parser available with JSON version
9752.09 (and JSON::XS version 2.2) and above. You have to provide a 17202.09 (and JSON::XS version 2.2) and above.
976dependency on your own: this module will load the JSON module, but
977AnyEvent does not depend on it itself.
978 1721
979Since JSON texts are fully self-delimiting, the C<json> read and write 1722Since JSON texts are fully self-delimiting, the C<json> read and write
980types are an ideal simple RPC protocol: just exchange JSON datagrams. See 1723types are an ideal simple RPC protocol: just exchange JSON datagrams. See
981the C<json> write type description, above, for an actual example. 1724the C<json> write type description, above, for an actual example.
982 1725
983=cut 1726=cut
984 1727
985register_read_type json => sub { 1728register_read_type json => sub {
986 my ($self, $cb, $accept, $reject, $skip) = @_; 1729 my ($self, $cb) = @_;
987 1730
988 require JSON; 1731 my $json = $self->{json} ||= json_coder;
989 1732
990 my $data; 1733 my $data;
991 my $rbuf = \$self->{rbuf};
992
993 my $json = $self->{json} ||= JSON->new->utf8;
994 1734
995 sub { 1735 sub {
996 my $ref = $json->incr_parse ($self->{rbuf}); 1736 my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
997 1737
998 if ($ref) { 1738 if ($ref) {
999 $self->{rbuf} = $json->incr_text; 1739 $_[0]{rbuf} = $json->incr_text;
1000 $json->incr_text = ""; 1740 $json->incr_text = "";
1001 $cb->($self, $ref); 1741 $cb->($_[0], $ref);
1002 1742
1003 1 1743 1
1744 } elsif ($@) {
1745 # error case
1746 $json->incr_skip;
1747
1748 $_[0]{rbuf} = $json->incr_text;
1749 $json->incr_text = "";
1750
1751 $_[0]->_error (Errno::EBADMSG);
1752
1753 ()
1004 } else { 1754 } else {
1005 $self->{rbuf} = ""; 1755 $_[0]{rbuf} = "";
1756
1006 () 1757 ()
1007 } 1758 }
1008 } 1759 }
1009}; 1760};
1010 1761
1762=item cbor => $cb->($handle, $scalar)
1763
1764Reads a CBOR value, decodes it and passes it to the callback. When a parse
1765error occurs, an C<EBADMSG> error will be raised.
1766
1767If a L<CBOR::XS> object was passed to the constructor, then that will be
1768used for the final decode, otherwise it will create a CBOR coder without
1769enabling any options.
1770
1771You have to provide a dependency to L<CBOR::XS> on your own: this module
1772will load the L<CBOR::XS> module, but AnyEvent does not depend on it
1773itself.
1774
1775Since CBOR values are fully self-delimiting, the C<cbor> read and write
1776types are an ideal simple RPC protocol: just exchange CBOR datagrams. See
1777the C<cbor> write type description, above, for an actual example.
1778
1779=cut
1780
1781register_read_type cbor => sub {
1782 my ($self, $cb) = @_;
1783
1784 my $cbor = $self->{cbor} ||= cbor_coder;
1785
1786 my $data;
1787
1788 sub {
1789 my (@value) = eval { $cbor->incr_parse ($_[0]{rbuf}) };
1790
1791 if (@value) {
1792 $cb->($_[0], @value);
1793
1794 1
1795 } elsif ($@) {
1796 # error case
1797 $cbor->incr_reset;
1798
1799 $_[0]->_error (Errno::EBADMSG);
1800
1801 ()
1802 } else {
1803 ()
1804 }
1805 }
1806};
1807
1808=item storable => $cb->($handle, $ref)
1809
1810Deserialises a L<Storable> frozen representation as written by the
1811C<storable> write type (BER-encoded length prefix followed by nfreeze'd
1812data).
1813
1814Raises C<EBADMSG> error if the data could not be decoded.
1815
1816=cut
1817
1818register_read_type storable => sub {
1819 my ($self, $cb) = @_;
1820
1821 require Storable unless $Storable::VERSION;
1822
1823 sub {
1824 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1825 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1826 or return;
1827
1828 my $format = length pack "w", $len;
1829
1830 # bypass unshift if we already have the remaining chunk
1831 if ($format + $len <= length $_[0]{rbuf}) {
1832 my $data = substr $_[0]{rbuf}, $format, $len;
1833 substr $_[0]{rbuf}, 0, $format + $len, "";
1834
1835 eval { $cb->($_[0], Storable::thaw ($data)); 1 }
1836 or return $_[0]->_error (Errno::EBADMSG);
1837 } else {
1838 # remove prefix
1839 substr $_[0]{rbuf}, 0, $format, "";
1840
1841 # read remaining chunk
1842 $_[0]->unshift_read (chunk => $len, sub {
1843 eval { $cb->($_[0], Storable::thaw ($_[1])); 1 }
1844 or $_[0]->_error (Errno::EBADMSG);
1845 });
1846 }
1847
1848 1
1849 }
1850};
1851
1852=item tls_detect => $cb->($handle, $detect, $major, $minor)
1853
1854Checks the input stream for a valid SSL or TLS handshake TLSPaintext
1855record without consuming anything. Only SSL version 3 or higher
1856is handled, up to the fictituous protocol 4.x (but both SSL3+ and
1857SSL2-compatible framing is supported).
1858
1859If it detects that the input data is likely TLS, it calls the callback
1860with a true value for C<$detect> and the (on-wire) TLS version as second
1861and third argument (C<$major> is C<3>, and C<$minor> is 0..4 for SSL
18623.0, TLS 1.0, 1.1, 1.2 and 1.3, respectively). If it detects the input
1863to be definitely not TLS, it calls the callback with a false value for
1864C<$detect>.
1865
1866The callback could use this information to decide whether or not to start
1867TLS negotiation.
1868
1869In all cases the data read so far is passed to the following read
1870handlers.
1871
1872Usually you want to use the C<tls_autostart> read type instead.
1873
1874If you want to design a protocol that works in the presence of TLS
1875dtection, make sure that any non-TLS data doesn't start with the octet 22
1876(ASCII SYN, 16 hex) or 128-255 (i.e. highest bit set). The checks this
1877read type does are a bit more strict, but might losen in the future to
1878accomodate protocol changes.
1879
1880This read type does not rely on L<AnyEvent::TLS> (and thus, not on
1881L<Net::SSLeay>).
1882
1883=item tls_autostart => [$tls_ctx, ]$tls
1884
1885Tries to detect a valid SSL or TLS handshake. If one is detected, it tries
1886to start tls by calling C<starttls> with the given arguments.
1887
1888In practise, C<$tls> must be C<accept>, or a Net::SSLeay context that has
1889been configured to accept, as servers do not normally send a handshake on
1890their own and ths cannot be detected in this way.
1891
1892See C<tls_detect> above for more details.
1893
1894Example: give the client a chance to start TLS before accepting a text
1895line.
1896
1897 $hdl->push_read (tls_autostart => "accept");
1898 $hdl->push_read (line => sub {
1899 print "received ", ($_[0]{tls} ? "encrypted" : "cleartext"), " <$_[1]>\n";
1900 });
1901
1902=cut
1903
1904register_read_type tls_detect => sub {
1905 my ($self, $cb) = @_;
1906
1907 sub {
1908 # this regex matches a full or partial tls record
1909 if (
1910 # ssl3+: type(22=handshake) major(=3) minor(any) length_hi
1911 $self->{rbuf} =~ /^(?:\z| \x16 (\z| [\x03\x04] (?:\z| . (?:\z| [\x00-\x40] ))))/xs
1912 # ssl2 comapatible: len_hi len_lo type(1) major minor dummy(forlength)
1913 or $self->{rbuf} =~ /^(?:\z| [\x80-\xff] (?:\z| . (?:\z| \x01 (\z| [\x03\x04] (?:\z| . (?:\z| . ))))))/xs
1914 ) {
1915 return if 3 != length $1; # partial match, can't decide yet
1916
1917 # full match, valid TLS record
1918 my ($major, $minor) = unpack "CC", $1;
1919 $cb->($self, "accept", $major, $minor);
1920 } else {
1921 # mismatch == guaranteed not TLS
1922 $cb->($self, undef);
1923 }
1924
1925 1
1926 }
1927};
1928
1929register_read_type tls_autostart => sub {
1930 my ($self, @tls) = @_;
1931
1932 $RH{tls_detect}($self, sub {
1933 return unless $_[1];
1934 $_[0]->starttls (@tls);
1935 })
1936};
1937
1011=back 1938=back
1012 1939
1013=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args) 1940=item custom read types - Package::anyevent_read_type $handle, $cb, @args
1014 1941
1015This function (not method) lets you add your own types to C<push_read>. 1942Instead of one of the predefined types, you can also specify the name
1943of a package. AnyEvent will try to load the package and then expects to
1944find a function named C<anyevent_read_type> inside. If it isn't found, it
1945progressively tries to load the parent package until it either finds the
1946function (good) or runs out of packages (bad).
1016 1947
1017Whenever the given C<type> is used, C<push_read> will invoke the code 1948Whenever this type is used, C<push_read> will invoke the function with the
1018reference with the handle object, the callback and the remaining 1949handle object, the original callback and the remaining arguments.
1019arguments.
1020 1950
1021The code reference is supposed to return a callback (usually a closure) 1951The function is supposed to return a callback (usually a closure) that
1022that works as a plain read callback (see C<< ->push_read ($cb) >>). 1952works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
1953mentally treat the function as a "configurable read type to read callback"
1954converter.
1023 1955
1024It should invoke the passed callback when it is done reading (remember to 1956It should invoke the original callback when it is done reading (remember
1025pass C<$handle> as first argument as all other callbacks do that). 1957to pass C<$handle> as first argument as all other callbacks do that,
1958although there is no strict requirement on this).
1026 1959
1027Note that this is a function, and all types registered this way will be
1028global, so try to use unique names.
1029
1030For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>, 1960For examples, see the source of this module (F<perldoc -m
1031search for C<register_read_type>)). 1961AnyEvent::Handle>, search for C<register_read_type>)).
1032 1962
1033=item $handle->stop_read 1963=item $handle->stop_read
1034 1964
1035=item $handle->start_read 1965=item $handle->start_read
1036 1966
1037In rare cases you actually do not want to read anything from the 1967In rare cases you actually do not want to read anything from the
1038socket. In this case you can call C<stop_read>. Neither C<on_read> no 1968socket. In this case you can call C<stop_read>. Neither C<on_read> nor
1039any queued callbacks will be executed then. To start reading again, call 1969any queued callbacks will be executed then. To start reading again, call
1040C<start_read>. 1970C<start_read>.
1041 1971
1972Note that AnyEvent::Handle will automatically C<start_read> for you when
1973you change the C<on_read> callback or push/unshift a read callback, and it
1974will automatically C<stop_read> for you when neither C<on_read> is set nor
1975there are any read requests in the queue.
1976
1977In older versions of this module (<= 5.3), these methods had no effect,
1978as TLS does not support half-duplex connections. In current versions they
1979work as expected, as this behaviour is required to avoid certain resource
1980attacks, where the program would be forced to read (and buffer) arbitrary
1981amounts of data before being able to send some data. The drawback is that
1982some readings of the the SSL/TLS specifications basically require this
1983attack to be working, as SSL/TLS implementations might stall sending data
1984during a rehandshake.
1985
1986As a guideline, during the initial handshake, you should not stop reading,
1987and as a client, it might cause problems, depending on your application.
1988
1042=cut 1989=cut
1043 1990
1044sub stop_read { 1991sub stop_read {
1045 my ($self) = @_; 1992 my ($self) = @_;
1046 1993
1048} 1995}
1049 1996
1050sub start_read { 1997sub start_read {
1051 my ($self) = @_; 1998 my ($self) = @_;
1052 1999
1053 unless ($self->{_rw} || $self->{_eof}) { 2000 unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
1054 Scalar::Util::weaken $self; 2001 Scalar::Util::weaken $self;
1055 2002
1056 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 2003 $self->{_rw} = AE::io $self->{fh}, 0, sub {
1057 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 2004 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1058 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 2005 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
1059 2006
1060 if ($len > 0) { 2007 if ($len > 0) {
1061 $self->{_activity} = time; 2008 $self->{_activity} = $self->{_ractivity} = AE::now;
1062 2009
1063 $self->{filter_r} 2010 if ($self->{tls}) {
1064 ? $self->{filter_r}->($self, $rbuf) 2011 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
2012
2013 &_dotls ($self);
2014 } else {
1065 : $self->_drain_rbuf; 2015 $self->_drain_rbuf;
2016 }
2017
2018 if ($len == $self->{read_size}) {
2019 $self->{read_size} *= 2;
2020 $self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
2021 if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
2022 }
1066 2023
1067 } elsif (defined $len) { 2024 } elsif (defined $len) {
1068 delete $self->{_rw}; 2025 delete $self->{_rw};
1069 delete $self->{_ww};
1070 delete $self->{_tw};
1071 $self->{_eof} = 1; 2026 $self->{_eof} = 1;
1072 $self->_drain_rbuf; 2027 $self->_drain_rbuf;
1073 2028
1074 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { 2029 } elsif ($! != EAGAIN && $! != EINTR && $! != EWOULDBLOCK && $! != WSAEWOULDBLOCK) {
1075 return $self->error; 2030 return $self->_error ($!, 1);
1076 } 2031 }
1077 }); 2032 };
1078 } 2033 }
1079} 2034}
1080 2035
2036our $ERROR_SYSCALL;
2037our $ERROR_WANT_READ;
2038
2039sub _tls_error {
2040 my ($self, $err) = @_;
2041
2042 return $self->_error ($!, 1)
2043 if $err == Net::SSLeay::ERROR_SYSCALL ();
2044
2045 my $err = Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
2046
2047 # reduce error string to look less scary
2048 $err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
2049
2050 if ($self->{_on_starttls}) {
2051 (delete $self->{_on_starttls})->($self, undef, $err);
2052 &_freetls;
2053 } else {
2054 &_freetls;
2055 $self->_error (Errno::EPROTO, 1, $err);
2056 }
2057}
2058
2059# poll the write BIO and send the data if applicable
2060# also decode read data if possible
2061# this is basically our TLS state machine
2062# more efficient implementations are possible with openssl,
2063# but not with the buggy and incomplete Net::SSLeay.
1081sub _dotls { 2064sub _dotls {
1082 my ($self) = @_; 2065 my ($self) = @_;
1083 2066
2067 my $tmp;
2068
1084 if (length $self->{_tls_wbuf}) { 2069 while (length $self->{_tls_wbuf}) {
1085 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) { 2070 if (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) <= 0) {
1086 substr $self->{_tls_wbuf}, 0, $len, ""; 2071 $tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
2072
2073 return $self->_tls_error ($tmp)
2074 if $tmp != $ERROR_WANT_READ
2075 && ($tmp != $ERROR_SYSCALL || $!);
2076
2077 last;
1087 } 2078 }
1088 }
1089 2079
2080 substr $self->{_tls_wbuf}, 0, $tmp, "";
2081 }
2082
2083 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
2084 unless (length $tmp) {
2085 $self->{_on_starttls}
2086 and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
2087 &_freetls;
2088
2089 if ($self->{on_stoptls}) {
2090 $self->{on_stoptls}($self);
2091 return;
2092 } else {
2093 # let's treat SSL-eof as we treat normal EOF
2094 delete $self->{_rw};
2095 $self->{_eof} = 1;
2096 }
2097 }
2098
2099 $self->{_tls_rbuf} .= $tmp;
2100 $self->_drain_rbuf;
2101 $self->{tls} or return; # tls session might have gone away in callback
2102 }
2103
2104 $tmp = Net::SSLeay::get_error ($self->{tls}, -1); # -1 is not neccessarily correct, but Net::SSLeay doesn't tell us
2105 return $self->_tls_error ($tmp)
2106 if $tmp != $ERROR_WANT_READ
2107 && ($tmp != $ERROR_SYSCALL || $!);
2108
1090 if (defined (my $buf = Net::SSLeay::BIO_read ($self->{_wbio}))) { 2109 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1091 $self->{wbuf} .= $buf; 2110 $self->{wbuf} .= $tmp;
1092 $self->_drain_wbuf; 2111 $self->_drain_wbuf;
2112 $self->{tls} or return; # tls session might have gone away in callback
1093 } 2113 }
1094 2114
1095 while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) { 2115 $self->{_on_starttls}
1096 $self->{rbuf} .= $buf; 2116 and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
1097 $self->_drain_rbuf; 2117 and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
1098 }
1099
1100 my $err = Net::SSLeay::get_error ($self->{tls}, -1);
1101
1102 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
1103 if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
1104 $self->error;
1105 } elsif ($err == Net::SSLeay::ERROR_SSL ()) {
1106 $! = &Errno::EIO;
1107 $self->error;
1108 }
1109
1110 # all others are fine for our purposes
1111 }
1112} 2118}
1113 2119
1114=item $handle->starttls ($tls[, $tls_ctx]) 2120=item $handle->starttls ($tls[, $tls_ctx])
1115 2121
1116Instead of starting TLS negotiation immediately when the AnyEvent::Handle 2122Instead of starting TLS negotiation immediately when the AnyEvent::Handle
1117object is created, you can also do that at a later time by calling 2123object is created, you can also do that at a later time by calling
1118C<starttls>. 2124C<starttls>. See the C<tls> constructor argument for general info.
2125
2126Starting TLS is currently an asynchronous operation - when you push some
2127write data and then call C<< ->starttls >> then TLS negotiation will start
2128immediately, after which the queued write data is then sent. This might
2129change in future versions, so best make sure you have no outstanding write
2130data when calling this method.
1119 2131
1120The first argument is the same as the C<tls> constructor argument (either 2132The first argument is the same as the C<tls> constructor argument (either
1121C<"connect">, C<"accept"> or an existing Net::SSLeay object). 2133C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1122 2134
1123The second argument is the optional C<Net::SSLeay::CTX> object that is 2135The second argument is the optional C<AnyEvent::TLS> object that is used
1124used when AnyEvent::Handle has to create its own TLS connection object. 2136when AnyEvent::Handle has to create its own TLS connection object, or
2137a hash reference with C<< key => value >> pairs that will be used to
2138construct a new context.
1125 2139
1126The TLS connection object will end up in C<< $handle->{tls} >> after this 2140The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1127call and can be used or changed to your liking. Note that the handshake 2141context in C<< $handle->{tls_ctx} >> after this call and can be used or
1128might have already started when this function returns. 2142changed to your liking. Note that the handshake might have already started
2143when this function returns.
1129 2144
1130=cut 2145Due to bugs in OpenSSL, it might or might not be possible to do multiple
2146handshakes on the same stream. It is best to not attempt to use the
2147stream after stopping TLS.
1131 2148
1132# TODO: maybe document... 2149This method may invoke callbacks (and therefore the handle might be
2150destroyed after it returns).
2151
2152=cut
2153
2154our %TLS_CACHE; #TODO not yet documented, should we?
2155
1133sub starttls { 2156sub starttls {
1134 my ($self, $ssl, $ctx) = @_; 2157 my ($self, $tls, $ctx) = @_;
1135 2158
1136 $self->stoptls; 2159 Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
2160 if $self->{tls};
1137 2161
1138 if ($ssl eq "accept") { 2162 unless (defined $AnyEvent::TLS::VERSION) {
1139 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 2163 eval {
1140 Net::SSLeay::set_accept_state ($ssl); 2164 require Net::SSLeay;
1141 } elsif ($ssl eq "connect") { 2165 require AnyEvent::TLS;
1142 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 2166 1
1143 Net::SSLeay::set_connect_state ($ssl); 2167 } or return $self->_error (Errno::EPROTO, 1, "TLS support not available on this system");
2168 }
2169
2170 $self->{tls} = $tls;
2171 $self->{tls_ctx} = $ctx if @_ > 2;
2172
2173 return unless $self->{fh};
2174
2175 $ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
2176 $ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
2177
2178 $tls = delete $self->{tls};
2179 $ctx = $self->{tls_ctx};
2180
2181 local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
2182
2183 if ("HASH" eq ref $ctx) {
2184 if ($ctx->{cache}) {
2185 my $key = $ctx+0;
2186 $ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
2187 } else {
2188 $ctx = new AnyEvent::TLS %$ctx;
2189 }
2190 }
1144 } 2191
1145 2192 $self->{tls_ctx} = $ctx || TLS_CTX ();
1146 $self->{tls} = $ssl; 2193 $self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
1147 2194
1148 # basically, this is deep magic (because SSL_read should have the same issues) 2195 # basically, this is deep magic (because SSL_read should have the same issues)
1149 # but the openssl maintainers basically said: "trust us, it just works". 2196 # but the openssl maintainers basically said: "trust us, it just works".
1150 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 2197 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
1151 # and mismaintained ssleay-module doesn't even offer them). 2198 # and mismaintained ssleay-module didn't offer them for a decade or so).
1152 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 2199 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
2200 #
2201 # in short: this is a mess.
2202 #
2203 # note that we do not try to keep the length constant between writes as we are required to do.
2204 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
2205 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
2206 # have identity issues in that area.
1153 Net::SSLeay::CTX_set_mode ($self->{tls}, 2207# Net::SSLeay::set_mode ($ssl,
1154 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 2208# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1155 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 2209# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
2210 Net::SSLeay::set_mode ($tls, 1|2);
1156 2211
1157 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 2212 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1158 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 2213 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1159 2214
2215 Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
2216 $self->{rbuf} = "";
2217
1160 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio}); 2218 Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
1161 2219
1162 $self->{filter_w} = sub { 2220 $self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
1163 $_[0]{_tls_wbuf} .= ${$_[1]}; 2221 if $self->{on_starttls};
1164 &_dotls; 2222
1165 }; 2223 &_dotls; # need to trigger the initial handshake
1166 $self->{filter_r} = sub { 2224 $self->start_read; # make sure we actually do read
1167 Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
1168 &_dotls;
1169 };
1170} 2225}
1171 2226
1172=item $handle->stoptls 2227=item $handle->stoptls
1173 2228
1174Destroys the SSL connection, if any. Partial read or write data will be 2229Shuts down the SSL connection - this makes a proper EOF handshake by
1175lost. 2230sending a close notify to the other side, but since OpenSSL doesn't
2231support non-blocking shut downs, it is not guaranteed that you can re-use
2232the stream afterwards.
2233
2234This method may invoke callbacks (and therefore the handle might be
2235destroyed after it returns).
1176 2236
1177=cut 2237=cut
1178 2238
1179sub stoptls { 2239sub stoptls {
1180 my ($self) = @_; 2240 my ($self) = @_;
1181 2241
1182 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 2242 if ($self->{tls} && $self->{fh}) {
2243 Net::SSLeay::shutdown ($self->{tls});
1183 2244
1184 delete $self->{_rbio}; 2245 &_dotls;
1185 delete $self->{_wbio}; 2246
1186 delete $self->{_tls_wbuf}; 2247# # we don't give a shit. no, we do, but we can't. no...#d#
1187 delete $self->{filter_r}; 2248# # we, we... have to use openssl :/#d#
1188 delete $self->{filter_w}; 2249# &_freetls;#d#
2250 }
1189} 2251}
2252
2253sub _freetls {
2254 my ($self) = @_;
2255
2256 return unless $self->{tls};
2257
2258 $self->{tls_ctx}->_put_session (delete $self->{tls})
2259 if $self->{tls} > 0;
2260
2261 delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
2262}
2263
2264=item $handle->resettls
2265
2266This rarely-used method simply resets and TLS state on the handle, usually
2267causing data loss.
2268
2269One case where it may be useful is when you want to skip over the data in
2270the stream but you are not interested in interpreting it, so data loss is
2271no concern.
2272
2273=cut
2274
2275*resettls = \&_freetls;
1190 2276
1191sub DESTROY { 2277sub DESTROY {
1192 my $self = shift; 2278 my ($self) = @_;
1193 2279
1194 $self->stoptls; 2280 &_freetls;
2281
2282 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
2283
2284 if ($linger && length $self->{wbuf} && $self->{fh}) {
2285 my $fh = delete $self->{fh};
2286 my $wbuf = delete $self->{wbuf};
2287
2288 my @linger;
2289
2290 push @linger, AE::io $fh, 1, sub {
2291 my $len = syswrite $fh, $wbuf, length $wbuf;
2292
2293 if ($len > 0) {
2294 substr $wbuf, 0, $len, "";
2295 } elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != EWOULDBLOCK && $! != WSAEWOULDBLOCK)) {
2296 @linger = (); # end
2297 }
2298 };
2299 push @linger, AE::timer $linger, 0, sub {
2300 @linger = ();
2301 };
2302 }
1195} 2303}
2304
2305=item $handle->destroy
2306
2307Shuts down the handle object as much as possible - this call ensures that
2308no further callbacks will be invoked and as many resources as possible
2309will be freed. Any method you will call on the handle object after
2310destroying it in this way will be silently ignored (and it will return the
2311empty list).
2312
2313Normally, you can just "forget" any references to an AnyEvent::Handle
2314object and it will simply shut down. This works in fatal error and EOF
2315callbacks, as well as code outside. It does I<NOT> work in a read or write
2316callback, so when you want to destroy the AnyEvent::Handle object from
2317within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
2318that case.
2319
2320Destroying the handle object in this way has the advantage that callbacks
2321will be removed as well, so if those are the only reference holders (as
2322is common), then one doesn't need to do anything special to break any
2323reference cycles.
2324
2325The handle might still linger in the background and write out remaining
2326data, as specified by the C<linger> option, however.
2327
2328=cut
2329
2330sub destroy {
2331 my ($self) = @_;
2332
2333 $self->DESTROY;
2334 %$self = ();
2335 bless $self, "AnyEvent::Handle::destroyed";
2336}
2337
2338sub AnyEvent::Handle::destroyed::AUTOLOAD {
2339 #nop
2340}
2341
2342=item $handle->destroyed
2343
2344Returns false as long as the handle hasn't been destroyed by a call to C<<
2345->destroy >>, true otherwise.
2346
2347Can be useful to decide whether the handle is still valid after some
2348callback possibly destroyed the handle. For example, C<< ->push_write >>,
2349C<< ->starttls >> and other methods can call user callbacks, which in turn
2350can destroy the handle, so work can be avoided by checking sometimes:
2351
2352 $hdl->starttls ("accept");
2353 return if $hdl->destroyed;
2354 $hdl->push_write (...
2355
2356Note that the call to C<push_write> will silently be ignored if the handle
2357has been destroyed, so often you can just ignore the possibility of the
2358handle being destroyed.
2359
2360=cut
2361
2362sub destroyed { 0 }
2363sub AnyEvent::Handle::destroyed::destroyed { 1 }
1196 2364
1197=item AnyEvent::Handle::TLS_CTX 2365=item AnyEvent::Handle::TLS_CTX
1198 2366
1199This function creates and returns the Net::SSLeay::CTX object used by 2367This function creates and returns the AnyEvent::TLS object used by default
1200default for TLS mode. 2368for TLS mode.
1201 2369
1202The context is created like this: 2370The context is created by calling L<AnyEvent::TLS> without any arguments.
1203
1204 Net::SSLeay::load_error_strings;
1205 Net::SSLeay::SSLeay_add_ssl_algorithms;
1206 Net::SSLeay::randomize;
1207
1208 my $CTX = Net::SSLeay::CTX_new;
1209
1210 Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
1211 2371
1212=cut 2372=cut
1213 2373
1214our $TLS_CTX; 2374our $TLS_CTX;
1215 2375
1216sub TLS_CTX() { 2376sub TLS_CTX() {
1217 $TLS_CTX || do { 2377 $TLS_CTX ||= do {
1218 require Net::SSLeay; 2378 require AnyEvent::TLS;
1219 2379
1220 Net::SSLeay::load_error_strings (); 2380 new AnyEvent::TLS
1221 Net::SSLeay::SSLeay_add_ssl_algorithms (); 2381 }
1222 Net::SSLeay::randomize (); 2382}
1223 2383
1224 $TLS_CTX = Net::SSLeay::CTX_new (); 2384=back
1225 2385
1226 Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
1227 2386
1228 $TLS_CTX 2387=head1 NONFREQUENTLY ASKED QUESTIONS
2388
2389=over 4
2390
2391=item I C<undef> the AnyEvent::Handle reference inside my callback and
2392still get further invocations!
2393
2394That's because AnyEvent::Handle keeps a reference to itself when handling
2395read or write callbacks.
2396
2397It is only safe to "forget" the reference inside EOF or error callbacks,
2398from within all other callbacks, you need to explicitly call the C<<
2399->destroy >> method.
2400
2401=item Why is my C<on_eof> callback never called?
2402
2403Probably because your C<on_error> callback is being called instead: When
2404you have outstanding requests in your read queue, then an EOF is
2405considered an error as you clearly expected some data.
2406
2407To avoid this, make sure you have an empty read queue whenever your handle
2408is supposed to be "idle" (i.e. connection closes are O.K.). You can set
2409an C<on_read> handler that simply pushes the first read requests in the
2410queue.
2411
2412See also the next question, which explains this in a bit more detail.
2413
2414=item How can I serve requests in a loop?
2415
2416Most protocols consist of some setup phase (authentication for example)
2417followed by a request handling phase, where the server waits for requests
2418and handles them, in a loop.
2419
2420There are two important variants: The first (traditional, better) variant
2421handles requests until the server gets some QUIT command, causing it to
2422close the connection first (highly desirable for a busy TCP server). A
2423client dropping the connection is an error, which means this variant can
2424detect an unexpected detection close.
2425
2426To handle this case, always make sure you have a non-empty read queue, by
2427pushing the "read request start" handler on it:
2428
2429 # we assume a request starts with a single line
2430 my @start_request; @start_request = (line => sub {
2431 my ($hdl, $line) = @_;
2432
2433 ... handle request
2434
2435 # push next request read, possibly from a nested callback
2436 $hdl->push_read (@start_request);
2437 });
2438
2439 # auth done, now go into request handling loop
2440 # now push the first @start_request
2441 $hdl->push_read (@start_request);
2442
2443By always having an outstanding C<push_read>, the handle always expects
2444some data and raises the C<EPIPE> error when the connction is dropped
2445unexpectedly.
2446
2447The second variant is a protocol where the client can drop the connection
2448at any time. For TCP, this means that the server machine may run out of
2449sockets easier, and in general, it means you cannot distinguish a protocl
2450failure/client crash from a normal connection close. Nevertheless, these
2451kinds of protocols are common (and sometimes even the best solution to the
2452problem).
2453
2454Having an outstanding read request at all times is possible if you ignore
2455C<EPIPE> errors, but this doesn't help with when the client drops the
2456connection during a request, which would still be an error.
2457
2458A better solution is to push the initial request read in an C<on_read>
2459callback. This avoids an error, as when the server doesn't expect data
2460(i.e. is idly waiting for the next request, an EOF will not raise an
2461error, but simply result in an C<on_eof> callback. It is also a bit slower
2462and simpler:
2463
2464 # auth done, now go into request handling loop
2465 $hdl->on_read (sub {
2466 my ($hdl) = @_;
2467
2468 # called each time we receive data but the read queue is empty
2469 # simply start read the request
2470
2471 $hdl->push_read (line => sub {
2472 my ($hdl, $line) = @_;
2473
2474 ... handle request
2475
2476 # do nothing special when the request has been handled, just
2477 # let the request queue go empty.
2478 });
2479 });
2480
2481=item I get different callback invocations in TLS mode/Why can't I pause
2482reading?
2483
2484Unlike, say, TCP, TLS connections do not consist of two independent
2485communication channels, one for each direction. Or put differently, the
2486read and write directions are not independent of each other: you cannot
2487write data unless you are also prepared to read, and vice versa.
2488
2489This means that, in TLS mode, you might get C<on_error> or C<on_eof>
2490callback invocations when you are not expecting any read data - the reason
2491is that AnyEvent::Handle always reads in TLS mode.
2492
2493During the connection, you have to make sure that you always have a
2494non-empty read-queue, or an C<on_read> watcher. At the end of the
2495connection (or when you no longer want to use it) you can call the
2496C<destroy> method.
2497
2498=item How do I read data until the other side closes the connection?
2499
2500If you just want to read your data into a perl scalar, the easiest way
2501to achieve this is by setting an C<on_read> callback that does nothing,
2502clearing the C<on_eof> callback and in the C<on_error> callback, the data
2503will be in C<$_[0]{rbuf}>:
2504
2505 $handle->on_read (sub { });
2506 $handle->on_eof (undef);
2507 $handle->on_error (sub {
2508 my $data = delete $_[0]{rbuf};
2509 });
2510
2511Note that this example removes the C<rbuf> member from the handle object,
2512which is not normally allowed by the API. It is expressly permitted in
2513this case only, as the handle object needs to be destroyed afterwards.
2514
2515The reason to use C<on_error> is that TCP connections, due to latencies
2516and packets loss, might get closed quite violently with an error, when in
2517fact all data has been received.
2518
2519It is usually better to use acknowledgements when transferring data,
2520to make sure the other side hasn't just died and you got the data
2521intact. This is also one reason why so many internet protocols have an
2522explicit QUIT command.
2523
2524=item I don't want to destroy the handle too early - how do I wait until
2525all data has been written?
2526
2527After writing your last bits of data, set the C<on_drain> callback
2528and destroy the handle in there - with the default setting of
2529C<low_water_mark> this will be called precisely when all data has been
2530written to the socket:
2531
2532 $handle->push_write (...);
2533 $handle->on_drain (sub {
2534 AE::log debug => "All data submitted to the kernel.";
2535 undef $handle;
2536 });
2537
2538If you just want to queue some data and then signal EOF to the other side,
2539consider using C<< ->push_shutdown >> instead.
2540
2541=item I want to contact a TLS/SSL server, I don't care about security.
2542
2543If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
2544connect to it and then create the AnyEvent::Handle with the C<tls>
2545parameter:
2546
2547 tcp_connect $host, $port, sub {
2548 my ($fh) = @_;
2549
2550 my $handle = new AnyEvent::Handle
2551 fh => $fh,
2552 tls => "connect",
2553 on_error => sub { ... };
2554
2555 $handle->push_write (...);
1229 } 2556 };
1230} 2557
2558=item I want to contact a TLS/SSL server, I do care about security.
2559
2560Then you should additionally enable certificate verification, including
2561peername verification, if the protocol you use supports it (see
2562L<AnyEvent::TLS>, C<verify_peername>).
2563
2564E.g. for HTTPS:
2565
2566 tcp_connect $host, $port, sub {
2567 my ($fh) = @_;
2568
2569 my $handle = new AnyEvent::Handle
2570 fh => $fh,
2571 peername => $host,
2572 tls => "connect",
2573 tls_ctx => { verify => 1, verify_peername => "https" },
2574 ...
2575
2576Note that you must specify the hostname you connected to (or whatever
2577"peername" the protocol needs) as the C<peername> argument, otherwise no
2578peername verification will be done.
2579
2580The above will use the system-dependent default set of trusted CA
2581certificates. If you want to check against a specific CA, add the
2582C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
2583
2584 tls_ctx => {
2585 verify => 1,
2586 verify_peername => "https",
2587 ca_file => "my-ca-cert.pem",
2588 },
2589
2590=item I want to create a TLS/SSL server, how do I do that?
2591
2592Well, you first need to get a server certificate and key. You have
2593three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
2594self-signed certificate (cheap. check the search engine of your choice,
2595there are many tutorials on the net) or c) make your own CA (tinyca2 is a
2596nice program for that purpose).
2597
2598Then create a file with your private key (in PEM format, see
2599L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
2600file should then look like this:
2601
2602 -----BEGIN RSA PRIVATE KEY-----
2603 ...header data
2604 ... lots of base64'y-stuff
2605 -----END RSA PRIVATE KEY-----
2606
2607 -----BEGIN CERTIFICATE-----
2608 ... lots of base64'y-stuff
2609 -----END CERTIFICATE-----
2610
2611The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
2612specify this file as C<cert_file>:
2613
2614 tcp_server undef, $port, sub {
2615 my ($fh) = @_;
2616
2617 my $handle = new AnyEvent::Handle
2618 fh => $fh,
2619 tls => "accept",
2620 tls_ctx => { cert_file => "my-server-keycert.pem" },
2621 ...
2622
2623When you have intermediate CA certificates that your clients might not
2624know about, just append them to the C<cert_file>.
1231 2625
1232=back 2626=back
1233 2627
1234=head1 SUBCLASSING AnyEvent::Handle 2628=head1 SUBCLASSING AnyEvent::Handle
1235 2629
1241=over 4 2635=over 4
1242 2636
1243=item * all constructor arguments become object members. 2637=item * all constructor arguments become object members.
1244 2638
1245At least initially, when you pass a C<tls>-argument to the constructor it 2639At least initially, when you pass a C<tls>-argument to the constructor it
1246will end up in C<< $handle->{tls} >>. Those members might be changes or 2640will end up in C<< $handle->{tls} >>. Those members might be changed or
1247mutated later on (for example C<tls> will hold the TLS connection object). 2641mutated later on (for example C<tls> will hold the TLS connection object).
1248 2642
1249=item * other object member names are prefixed with an C<_>. 2643=item * other object member names are prefixed with an C<_>.
1250 2644
1251All object members not explicitly documented (internal use) are prefixed 2645All object members not explicitly documented (internal use) are prefixed
1254 2648
1255=item * all members not documented here and not prefixed with an underscore 2649=item * all members not documented here and not prefixed with an underscore
1256are free to use in subclasses. 2650are free to use in subclasses.
1257 2651
1258Of course, new versions of AnyEvent::Handle may introduce more "public" 2652Of course, new versions of AnyEvent::Handle may introduce more "public"
1259member variables, but thats just life, at least it is documented. 2653member variables, but that's just life. At least it is documented.
1260 2654
1261=back 2655=back
1262 2656
1263=head1 AUTHOR 2657=head1 AUTHOR
1264 2658
1265Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>. 2659Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
1266 2660
1267=cut 2661=cut
1268 2662
12691; # End of AnyEvent::Handle 26631
2664

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