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Revision 1.242 by root, Wed Dec 10 04:29:33 2014 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/;
12
13=head1 NAME 1=head1 NAME
14 2
15AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent 3AnyEvent::Handle - non-blocking I/O on streaming handles via AnyEvent
16
17=cut
18
19our $VERSION = '0.04';
20 4
21=head1 SYNOPSIS 5=head1 SYNOPSIS
22 6
23 use AnyEvent; 7 use AnyEvent;
24 use AnyEvent::Handle; 8 use AnyEvent::Handle;
25 9
26 my $cv = AnyEvent->condvar; 10 my $cv = AnyEvent->condvar;
27 11
28 my $handle = 12 my $hdl; $hdl = new AnyEvent::Handle
29 AnyEvent::Handle->new (
30 fh => \*STDIN, 13 fh => \*STDIN,
31 on_eof => sub { 14 on_error => sub {
32 $cv->broadcast; 15 my ($hdl, $fatal, $msg) = @_;
33 }, 16 AE::log error => $msg;
17 $hdl->destroy;
18 $cv->send;
34 ); 19 };
35 20
36 # send some request line 21 # send some request line
37 $handle->push_write ("getinfo\015\012"); 22 $hdl->push_write ("getinfo\015\012");
38 23
39 # read the response line 24 # read the response line
40 $handle->push_read (line => sub { 25 $hdl->push_read (line => sub {
41 my ($handle, $line) = @_; 26 my ($hdl, $line) = @_;
42 warn "read line <$line>\n"; 27 say "got line <$line>";
43 $cv->send; 28 $cv->send;
44 }); 29 });
45 30
46 $cv->recv; 31 $cv->recv;
47 32
48=head1 DESCRIPTION 33=head1 DESCRIPTION
49 34
50This 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 on
51filehandles. For utility functions for doing non-blocking connects and accepts 36stream-based filehandles (sockets, pipes, and other stream things).
52on sockets see L<AnyEvent::Util>.
53 37
38The L<AnyEvent::Intro> tutorial contains some well-documented
39AnyEvent::Handle examples.
40
54In the following, when the documentation refers to of "bytes" then this 41In the following, where the documentation refers to "bytes", it means
55means characters. As sysread and syswrite are used for all I/O, their 42characters. As sysread and syswrite are used for all I/O, their
56treatment of characters applies to this module as well. 43treatment of characters applies to this module as well.
44
45At the very minimum, you should specify C<fh> or C<connect>, and the
46C<on_error> callback.
57 47
58All callbacks will be invoked with the handle object as their first 48All callbacks will be invoked with the handle object as their first
59argument. 49argument.
60 50
51=cut
52
53package AnyEvent::Handle;
54
55use Scalar::Util ();
56use List::Util ();
57use Carp ();
58use Errno qw(EAGAIN EINTR);
59
60use AnyEvent (); BEGIN { AnyEvent::common_sense }
61use AnyEvent::Util qw(WSAEWOULDBLOCK);
62
63our $VERSION = $AnyEvent::VERSION;
64
65sub _load_func($) {
66 my $func = $_[0];
67
68 unless (defined &$func) {
69 my $pkg = $func;
70 do {
71 $pkg =~ s/::[^:]+$//
72 or return;
73 eval "require $pkg";
74 } until defined &$func;
75 }
76
77 \&$func
78}
79
80sub MAX_READ_SIZE() { 131072 }
81
61=head1 METHODS 82=head1 METHODS
62 83
63=over 4 84=over 4
64 85
65=item B<new (%args)> 86=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
66 87
67The constructor supports these arguments (all as key => value pairs). 88The constructor supports these arguments (all as C<< key => value >> pairs).
68 89
69=over 4 90=over 4
70 91
71=item fh => $filehandle [MANDATORY] 92=item fh => $filehandle [C<fh> or C<connect> MANDATORY]
72 93
73The filehandle this L<AnyEvent::Handle> object will operate on. 94The filehandle this L<AnyEvent::Handle> object will operate on.
74
75NOTE: The filehandle will be set to non-blocking (using 95NOTE: The filehandle will be set to non-blocking mode (using
76AnyEvent::Util::fh_nonblocking). 96C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
97that mode.
77 98
78=item on_eof => $cb->($handle) 99=item connect => [$host, $service] [C<fh> or C<connect> MANDATORY]
79 100
80Set the callback to be called on EOF. 101Try to connect to the specified host and service (port), using
102C<AnyEvent::Socket::tcp_connect>. The C<$host> additionally becomes the
103default C<peername>.
81 104
82While not mandatory, it is highly recommended to set an eof callback, 105You have to specify either this parameter, or C<fh>, above.
83otherwise you might end up with a closed socket while you are still
84waiting for data.
85 106
107It is possible to push requests on the read and write queues, and modify
108properties of the stream, even while AnyEvent::Handle is connecting.
109
110When this parameter is specified, then the C<on_prepare>,
111C<on_connect_error> and C<on_connect> callbacks will be called under the
112appropriate circumstances:
113
114=over 4
115
86=item on_error => $cb->($handle) 116=item on_prepare => $cb->($handle)
87 117
118This (rarely used) callback is called before a new connection is
119attempted, but after the file handle has been created (you can access that
120file handle via C<< $handle->{fh} >>). It could be used to prepare the
121file handle with parameters required for the actual connect (as opposed to
122settings that can be changed when the connection is already established).
123
124The return value of this callback should be the connect timeout value in
125seconds (or C<0>, or C<undef>, or the empty list, to indicate that the
126default timeout is to be used).
127
128=item on_connect => $cb->($handle, $host, $port, $retry->())
129
130This callback is called when a connection has been successfully established.
131
132The peer's numeric host and port (the socket peername) are passed as
133parameters, together with a retry callback. At the time it is called the
134read and write queues, EOF status, TLS status and similar properties of
135the handle will have been reset.
136
137If, for some reason, the handle is not acceptable, calling C<$retry> will
138continue with the next connection target (in case of multi-homed hosts or
139SRV records there can be multiple connection endpoints). The C<$retry>
140callback can be invoked after the connect callback returns, i.e. one can
141start a handshake and then decide to retry with the next host if the
142handshake fails.
143
144In most cases, you should ignore the C<$retry> parameter.
145
146=item on_connect_error => $cb->($handle, $message)
147
148This callback is called when the connection could not be
149established. C<$!> will contain the relevant error code, and C<$message> a
150message describing it (usually the same as C<"$!">).
151
152If this callback isn't specified, then C<on_error> will be called with a
153fatal error instead.
154
155=back
156
157=item on_error => $cb->($handle, $fatal, $message)
158
88This is the fatal error callback, that is called when, well, a fatal error 159This is the error callback, which is called when, well, some error
89occurs, such as not being able to resolve the hostname, failure to connect 160occured, such as not being able to resolve the hostname, failure to
90or a read error. 161connect, or a read error.
91 162
92The object will not be in a usable state when this callback has been 163Some errors are fatal (which is indicated by C<$fatal> being true). On
93called. 164fatal errors the handle object will be destroyed (by a call to C<< ->
165destroy >>) after invoking the error callback (which means you are free to
166examine the handle object). Examples of fatal errors are an EOF condition
167with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
168cases where the other side can close the connection at will, it is
169often easiest to not report C<EPIPE> errors in this callback.
94 170
171AnyEvent::Handle tries to find an appropriate error code for you to check
172against, but in some cases (TLS errors), this does not work well.
173
174If you report the error to the user, it is recommended to always output
175the C<$message> argument in human-readable error messages (you don't need
176to report C<"$!"> if you report C<$message>).
177
178If you want to react programmatically to the error, then looking at C<$!>
179and comparing it against some of the documented C<Errno> values is usually
180better than looking at the C<$message>.
181
182Non-fatal errors can be retried by returning, but it is recommended
183to simply ignore this parameter and instead abondon the handle object
184when this callback is invoked. Examples of non-fatal errors are timeouts
185C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
186
95On callback entrance, the value of C<$!> contains the operating system 187On entry to the callback, the value of C<$!> contains the operating
96error (or C<ENOSPC>, C<EPIPE> or C<EBADMSG>). 188system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
97 189C<EPROTO>).
98The callback should throw an exception. If it returns, then
99AnyEvent::Handle will C<croak> for you.
100 190
101While not mandatory, it is I<highly> recommended to set this callback, as 191While not mandatory, it is I<highly> recommended to set this callback, as
102you will not be notified of errors otherwise. The default simply calls 192you will not be notified of errors otherwise. The default just calls
103die. 193C<croak>.
104 194
105=item on_read => $cb->($handle) 195=item on_read => $cb->($handle)
106 196
107This sets the default read callback, which is called when data arrives 197This sets the default read callback, which is called when data arrives
108and no read request is in the queue. 198and no read request is in the queue (unlike read queue callbacks, this
199callback will only be called when at least one octet of data is in the
200read buffer).
109 201
110To access (and remove data from) the read buffer, use the C<< ->rbuf >> 202To access (and remove data from) the read buffer, use the C<< ->rbuf >>
111method or access the C<$handle->{rbuf}> member directly. 203method or access the C<< $handle->{rbuf} >> member directly. Note that you
204must not enlarge or modify the read buffer, you can only remove data at
205the beginning from it.
112 206
207You can also call C<< ->push_read (...) >> or any other function that
208modifies the read queue. Or do both. Or ...
209
113When an EOF condition is detected then AnyEvent::Handle will first try to 210When an EOF condition is detected, AnyEvent::Handle will first try to
114feed all the remaining data to the queued callbacks and C<on_read> before 211feed all the remaining data to the queued callbacks and C<on_read> before
115calling the C<on_eof> callback. If no progress can be made, then a fatal 212calling the C<on_eof> callback. If no progress can be made, then a fatal
116error will be raised (with C<$!> set to C<EPIPE>). 213error will be raised (with C<$!> set to C<EPIPE>).
117 214
215Note that, unlike requests in the read queue, an C<on_read> callback
216doesn't mean you I<require> some data: if there is an EOF and there
217are outstanding read requests then an error will be flagged. With an
218C<on_read> callback, the C<on_eof> callback will be invoked.
219
220=item on_eof => $cb->($handle)
221
222Set the callback to be called when an end-of-file condition is detected,
223i.e. in the case of a socket, when the other side has closed the
224connection cleanly, and there are no outstanding read requests in the
225queue (if there are read requests, then an EOF counts as an unexpected
226connection close and will be flagged as an error).
227
228For sockets, this just means that the other side has stopped sending data,
229you can still try to write data, and, in fact, one can return from the EOF
230callback and continue writing data, as only the read part has been shut
231down.
232
233If an EOF condition has been detected but no C<on_eof> callback has been
234set, then a fatal error will be raised with C<$!> set to <0>.
235
118=item on_drain => $cb->($handle) 236=item on_drain => $cb->($handle)
119 237
120This sets the callback that is called when the write buffer becomes empty 238This sets the callback that is called once when the write buffer becomes
121(or when the callback is set and the buffer is empty already). 239empty (and immediately when the handle object is created).
122 240
123To append to the write buffer, use the C<< ->push_write >> method. 241To append to the write buffer, use the C<< ->push_write >> method.
242
243This callback is useful when you don't want to put all of your write data
244into the queue at once, for example, when you want to write the contents
245of some file to the socket you might not want to read the whole file into
246memory and push it into the queue, but instead only read more data from
247the file when the write queue becomes empty.
248
249=item timeout => $fractional_seconds
250
251=item rtimeout => $fractional_seconds
252
253=item wtimeout => $fractional_seconds
254
255If non-zero, then these enables an "inactivity" timeout: whenever this
256many seconds pass without a successful read or write on the underlying
257file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
258will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
259error will be raised).
260
261There are three variants of the timeouts that work independently of each
262other, for both read and write (triggered when nothing was read I<OR>
263written), just read (triggered when nothing was read), and just write:
264C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
265C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
266C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
267
268Note that timeout processing is active even when you do not have any
269outstanding read or write requests: If you plan to keep the connection
270idle then you should disable the timeout temporarily or ignore the
271timeout in the corresponding C<on_timeout> callback, in which case
272AnyEvent::Handle will simply restart the timeout.
273
274Zero (the default) disables the corresponding timeout.
275
276=item on_timeout => $cb->($handle)
277
278=item on_rtimeout => $cb->($handle)
279
280=item on_wtimeout => $cb->($handle)
281
282Called whenever the inactivity timeout passes. If you return from this
283callback, then the timeout will be reset as if some activity had happened,
284so this condition is not fatal in any way.
124 285
125=item rbuf_max => <bytes> 286=item rbuf_max => <bytes>
126 287
127If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>) 288If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
128when the read buffer ever (strictly) exceeds this size. This is useful to 289when the read buffer ever (strictly) exceeds this size. This is useful to
129avoid denial-of-service attacks. 290avoid some forms of denial-of-service attacks.
130 291
131For example, a server accepting connections from untrusted sources should 292For example, a server accepting connections from untrusted sources should
132be configured to accept only so-and-so much data that it cannot act on 293be configured to accept only so-and-so much data that it cannot act on
133(for example, when expecting a line, an attacker could send an unlimited 294(for example, when expecting a line, an attacker could send an unlimited
134amount of data without a callback ever being called as long as the line 295amount of data without a callback ever being called as long as the line
135isn't finished). 296isn't finished).
136 297
298=item wbuf_max => <bytes>
299
300If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
301when the write buffer ever (strictly) exceeds this size. This is useful to
302avoid some forms of denial-of-service attacks.
303
304Although the units of this parameter is bytes, this is the I<raw> number
305of bytes not yet accepted by the kernel. This can make a difference when
306you e.g. use TLS, as TLS typically makes your write data larger (but it
307can also make it smaller due to compression).
308
309As an example of when this limit is useful, take a chat server that sends
310chat messages to a client. If the client does not read those in a timely
311manner then the send buffer in the server would grow unbounded.
312
313=item autocork => <boolean>
314
315When disabled (the default), C<push_write> will try to immediately
316write the data to the handle if possible. This avoids having to register
317a write watcher and wait for the next event loop iteration, but can
318be inefficient if you write multiple small chunks (on the wire, this
319disadvantage is usually avoided by your kernel's nagle algorithm, see
320C<no_delay>, but this option can save costly syscalls).
321
322When enabled, writes will always be queued till the next event loop
323iteration. This is efficient when you do many small writes per iteration,
324but less efficient when you do a single write only per iteration (or when
325the write buffer often is full). It also increases write latency.
326
327=item no_delay => <boolean>
328
329When doing small writes on sockets, your operating system kernel might
330wait a bit for more data before actually sending it out. This is called
331the Nagle algorithm, and usually it is beneficial.
332
333In some situations you want as low a delay as possible, which can be
334accomplishd by setting this option to a true value.
335
336The default is your operating system's default behaviour (most likely
337enabled). This option explicitly enables or disables it, if possible.
338
339=item keepalive => <boolean>
340
341Enables (default disable) the SO_KEEPALIVE option on the stream socket:
342normally, TCP connections have no time-out once established, so TCP
343connections, once established, can stay alive forever even when the other
344side has long gone. TCP keepalives are a cheap way to take down long-lived
345TCP connections when the other side becomes unreachable. While the default
346is OS-dependent, TCP keepalives usually kick in after around two hours,
347and, if the other side doesn't reply, take down the TCP connection some 10
348to 15 minutes later.
349
350It is harmless to specify this option for file handles that do not support
351keepalives, and enabling it on connections that are potentially long-lived
352is usually a good idea.
353
354=item oobinline => <boolean>
355
356BSD majorly fucked up the implementation of TCP urgent data. The result
357is that almost no OS implements TCP according to the specs, and every OS
358implements it slightly differently.
359
360If you want to handle TCP urgent data, then setting this flag (the default
361is enabled) gives you the most portable way of getting urgent data, by
362putting it into the stream.
363
364Since BSD emulation of OOB data on top of TCP's urgent data can have
365security implications, AnyEvent::Handle sets this flag automatically
366unless explicitly specified. Note that setting this flag after
367establishing a connection I<may> be a bit too late (data loss could
368already have occured on BSD systems), but at least it will protect you
369from most attacks.
370
137=item read_size => <bytes> 371=item read_size => <bytes>
138 372
139The default read block size (the amount of bytes this module will try to read 373The initial read block size, the number of bytes this module will try
140on each [loop iteration). Default: C<4096>. 374to read during each loop iteration. Each handle object will consume
375at least this amount of memory for the read buffer as well, so when
376handling many connections watch out for memory requirements). See also
377C<max_read_size>. Default: C<2048>.
378
379=item max_read_size => <bytes>
380
381The maximum read buffer size used by the dynamic adjustment
382algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
383one go it will double C<read_size> up to the maximum given by this
384option. Default: C<131072> or C<read_size>, whichever is higher.
141 385
142=item low_water_mark => <bytes> 386=item low_water_mark => <bytes>
143 387
144Sets the amount of bytes (default: C<0>) that make up an "empty" write 388Sets the number of bytes (default: C<0>) that make up an "empty" write
145buffer: If the write reaches this size or gets even samller it is 389buffer: If the buffer reaches this size or gets even samller it is
146considered empty. 390considered empty.
147 391
392Sometimes it can be beneficial (for performance reasons) to add data to
393the write buffer before it is fully drained, but this is a rare case, as
394the operating system kernel usually buffers data as well, so the default
395is good in almost all cases.
396
397=item linger => <seconds>
398
399If this is non-zero (default: C<3600>), the destructor of the
400AnyEvent::Handle object will check whether there is still outstanding
401write data and will install a watcher that will write this data to the
402socket. No errors will be reported (this mostly matches how the operating
403system treats outstanding data at socket close time).
404
405This will not work for partial TLS data that could not be encoded
406yet. This data will be lost. Calling the C<stoptls> method in time might
407help.
408
409=item peername => $string
410
411A string used to identify the remote site - usually the DNS hostname
412(I<not> IDN!) used to create the connection, rarely the IP address.
413
414Apart from being useful in error messages, this string is also used in TLS
415peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
416verification will be skipped when C<peername> is not specified or is
417C<undef>.
418
148=item tls => "accept" | "connect" | Net::SSLeay::SSL object 419=item tls => "accept" | "connect" | Net::SSLeay::SSL object
149 420
150When this parameter is given, it enables TLS (SSL) mode, that means it 421When this parameter is given, it enables TLS (SSL) mode, that means
151will start making tls handshake and will transparently encrypt/decrypt 422AnyEvent will start a TLS handshake as soon as the connection has been
152data. 423established and will transparently encrypt/decrypt data afterwards.
424
425All TLS protocol errors will be signalled as C<EPROTO>, with an
426appropriate error message.
153 427
154TLS mode requires Net::SSLeay to be installed (it will be loaded 428TLS mode requires Net::SSLeay to be installed (it will be loaded
155automatically when you try to create a TLS handle). 429automatically when you try to create a TLS handle): this module doesn't
430have a dependency on that module, so if your module requires it, you have
431to add the dependency yourself. If Net::SSLeay cannot be loaded or is too
432old, you get an C<EPROTO> error.
156 433
157For the TLS server side, use C<accept>, and for the TLS client side of a 434Unlike TCP, TLS has a server and client side: for the TLS server side, use
158connection, use C<connect> mode. 435C<accept>, and for the TLS client side of a connection, use C<connect>
436mode.
159 437
160You can also provide your own TLS connection object, but you have 438You can also provide your own TLS connection object, but you have
161to make sure that you call either C<Net::SSLeay::set_connect_state> 439to make sure that you call either C<Net::SSLeay::set_connect_state>
162or C<Net::SSLeay::set_accept_state> on it before you pass it to 440or C<Net::SSLeay::set_accept_state> on it before you pass it to
163AnyEvent::Handle. 441AnyEvent::Handle. Also, this module will take ownership of this connection
442object.
164 443
444At some future point, AnyEvent::Handle might switch to another TLS
445implementation, then the option to use your own session object will go
446away.
447
448B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
449passing in the wrong integer will lead to certain crash. This most often
450happens when one uses a stylish C<< tls => 1 >> and is surprised about the
451segmentation fault.
452
165See the C<starttls> method if you need to start TLs negotiation later. 453Use the C<< ->starttls >> method if you need to start TLS negotiation later.
166 454
167=item tls_ctx => $ssl_ctx 455=item tls_ctx => $anyevent_tls
168 456
169Use the given Net::SSLeay::CTX object to create the new TLS connection 457Use the given C<AnyEvent::TLS> object to create the new TLS connection
170(unless a connection object was specified directly). If this parameter is 458(unless a connection object was specified directly). If this
171missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 459parameter is missing (or C<undef>), then AnyEvent::Handle will use
460C<AnyEvent::Handle::TLS_CTX>.
172 461
462Instead of an object, you can also specify a hash reference with C<< key
463=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
464new TLS context object.
465
466=item on_starttls => $cb->($handle, $success[, $error_message])
467
468This callback will be invoked when the TLS/SSL handshake has finished. If
469C<$success> is true, then the TLS handshake succeeded, otherwise it failed
470(C<on_stoptls> will not be called in this case).
471
472The session in C<< $handle->{tls} >> can still be examined in this
473callback, even when the handshake was not successful.
474
475TLS handshake failures will not cause C<on_error> to be invoked when this
476callback is in effect, instead, the error message will be passed to C<on_starttls>.
477
478Without this callback, handshake failures lead to C<on_error> being
479called as usual.
480
481Note that you cannot just call C<starttls> again in this callback. If you
482need to do that, start an zero-second timer instead whose callback can
483then call C<< ->starttls >> again.
484
485=item on_stoptls => $cb->($handle)
486
487When a SSLv3/TLS shutdown/close notify/EOF is detected and this callback is
488set, then it will be invoked after freeing the TLS session. If it is not,
489then a TLS shutdown condition will be treated like a normal EOF condition
490on the handle.
491
492The session in C<< $handle->{tls} >> can still be examined in this
493callback.
494
495This callback will only be called on TLS shutdowns, not when the
496underlying handle signals EOF.
497
173=item json => JSON or JSON::XS object 498=item json => L<JSON>, L<JSON::PP> or L<JSON::XS> object
174 499
175This is the json coder object used by the C<json> read and write types. 500This is the json coder object used by the C<json> read and write types.
176 501
177If you don't supply it, then AnyEvent::Handle will create and use a 502If you don't supply it, then AnyEvent::Handle will create and use a
178suitable one, which will write and expect UTF-8 encoded JSON texts. 503suitable one (on demand), which will write and expect UTF-8 encoded
504JSON texts (either using L<JSON::XS> or L<JSON>). The written texts are
505guaranteed not to contain any newline character.
179 506
507For security reasons, this encoder will likely I<not> handle numbers and
508strings, only arrays and objects/hashes. The reason is that originally
509JSON was self-delimited, but Dougles Crockford thought it was a splendid
510idea to redefine JSON incompatibly, so this is no longer true.
511
512For protocols that used back-to-back JSON texts, this might lead to
513run-ins, where two or more JSON texts will be interpreted as one JSON
514text.
515
516For this reason, if the default encoder uses L<JSON::XS>, it will default
517to not allowing anything but arrays and objects/hashes, at least for the
518forseeable future (it will change at some point). This might or might not
519be true for the L<JSON> module, so this might cause a security issue.
520
521If you depend on either behaviour, you should create your own json object
522and pass it in explicitly.
523
524=item cbor => L<CBOR::XS> object
525
526This is the cbor coder object used by the C<cbor> read and write types.
527
528If you don't supply it, then AnyEvent::Handle will create and use a
529suitable one (on demand), which will write CBOR without using extensions,
530if possible.
531
180Note that you are responsible to depend on the JSON module if you want to 532Note that you are responsible to depend on the L<CBOR::XS> module if you
181use this functionality, as AnyEvent does not have a dependency itself. 533want to use this functionality, as AnyEvent does not have a dependency on
182 534it itself.
183=item filter_r => $cb
184
185=item filter_w => $cb
186
187These exist, but are undocumented at this time.
188 535
189=back 536=back
190 537
191=cut 538=cut
192 539
193sub new { 540sub new {
194 my $class = shift; 541 my $class = shift;
195
196 my $self = bless { @_ }, $class; 542 my $self = bless { @_ }, $class;
197 543
198 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 544 if ($self->{fh}) {
545 $self->_start;
546 return unless $self->{fh}; # could be gone by now
547
548 } elsif ($self->{connect}) {
549 require AnyEvent::Socket;
550
551 $self->{peername} = $self->{connect}[0]
552 unless exists $self->{peername};
553
554 $self->{_skip_drain_rbuf} = 1;
555
556 {
557 Scalar::Util::weaken (my $self = $self);
558
559 $self->{_connect} =
560 AnyEvent::Socket::tcp_connect (
561 $self->{connect}[0],
562 $self->{connect}[1],
563 sub {
564 my ($fh, $host, $port, $retry) = @_;
565
566 delete $self->{_connect}; # no longer needed
567
568 if ($fh) {
569 $self->{fh} = $fh;
570
571 delete $self->{_skip_drain_rbuf};
572 $self->_start;
573
574 $self->{on_connect}
575 and $self->{on_connect}($self, $host, $port, sub {
576 delete @$self{qw(fh _tw _rtw _wtw _ww _rw _eof _queue rbuf _wbuf tls _tls_rbuf _tls_wbuf)};
577 $self->{_skip_drain_rbuf} = 1;
578 &$retry;
579 });
580
581 } else {
582 if ($self->{on_connect_error}) {
583 $self->{on_connect_error}($self, "$!");
584 $self->destroy if $self;
585 } else {
586 $self->_error ($!, 1);
587 }
588 }
589 },
590 sub {
591 local $self->{fh} = $_[0];
592
593 $self->{on_prepare}
594 ? $self->{on_prepare}->($self)
595 : ()
596 }
597 );
598 }
599
600 } else {
601 Carp::croak "AnyEvent::Handle: either an existing fh or the connect parameter must be specified";
602 }
603
604 $self
605}
606
607sub _start {
608 my ($self) = @_;
609
610 # too many clueless people try to use udp and similar sockets
611 # with AnyEvent::Handle, do them a favour.
612 my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
613 Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
614 if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
199 615
200 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 616 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
201 617
202 if ($self->{tls}) { 618 $self->{_activity} =
203 require Net::SSLeay; 619 $self->{_ractivity} =
620 $self->{_wactivity} = AE::now;
621
622 $self->{read_size} ||= 2048;
623 $self->{max_read_size} = $self->{read_size}
624 if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
625
626 $self->timeout (delete $self->{timeout} ) if $self->{timeout};
627 $self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
628 $self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
629
630 $self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
631 $self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
632
633 $self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
634
204 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); 635 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
205 } 636 if $self->{tls};
206 637
207 $self->on_eof (delete $self->{on_eof} ) if $self->{on_eof};
208 $self->on_error (delete $self->{on_error}) if $self->{on_error};
209 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 638 $self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
210 $self->on_read (delete $self->{on_read} ) if $self->{on_read};
211 639
212 $self->start_read; 640 $self->start_read
641 if $self->{on_read} || @{ $self->{_queue} };
213 642
214 $self 643 $self->_drain_wbuf;
215} 644}
216 645
217sub _shutdown {
218 my ($self) = @_;
219
220 delete $self->{_rw};
221 delete $self->{_ww};
222 delete $self->{fh};
223}
224
225sub error { 646sub _error {
226 my ($self) = @_; 647 my ($self, $errno, $fatal, $message) = @_;
227 648
228 { 649 $! = $errno;
229 local $!; 650 $message ||= "$!";
230 $self->_shutdown;
231 }
232 651
233 $self->{on_error}($self)
234 if $self->{on_error}; 652 if ($self->{on_error}) {
235 653 $self->{on_error}($self, $fatal, $message);
654 $self->destroy if $fatal;
655 } elsif ($self->{fh} || $self->{connect}) {
656 $self->destroy;
236 Carp::croak "AnyEvent::Handle uncaught fatal error: $!"; 657 Carp::croak "AnyEvent::Handle uncaught error: $message";
658 }
237} 659}
238 660
239=item $fh = $handle->fh 661=item $fh = $handle->fh
240 662
241This method returns the file handle of the L<AnyEvent::Handle> object. 663This method returns the file handle used to create the L<AnyEvent::Handle> object.
242 664
243=cut 665=cut
244 666
245sub fh { $_[0]{fh} } 667sub fh { $_[0]{fh} }
246 668
262 684
263sub on_eof { 685sub on_eof {
264 $_[0]{on_eof} = $_[1]; 686 $_[0]{on_eof} = $_[1];
265} 687}
266 688
689=item $handle->on_timeout ($cb)
690
691=item $handle->on_rtimeout ($cb)
692
693=item $handle->on_wtimeout ($cb)
694
695Replace the current C<on_timeout>, C<on_rtimeout> or C<on_wtimeout>
696callback, or disables the callback (but not the timeout) if C<$cb> =
697C<undef>. See the C<timeout> constructor argument and method.
698
699=cut
700
701# see below
702
703=item $handle->autocork ($boolean)
704
705Enables or disables the current autocork behaviour (see C<autocork>
706constructor argument). Changes will only take effect on the next write.
707
708=cut
709
710sub autocork {
711 $_[0]{autocork} = $_[1];
712}
713
714=item $handle->no_delay ($boolean)
715
716Enables or disables the C<no_delay> setting (see constructor argument of
717the same name for details).
718
719=cut
720
721sub no_delay {
722 $_[0]{no_delay} = $_[1];
723
724 setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
725 if $_[0]{fh};
726}
727
728=item $handle->keepalive ($boolean)
729
730Enables or disables the C<keepalive> setting (see constructor argument of
731the same name for details).
732
733=cut
734
735sub keepalive {
736 $_[0]{keepalive} = $_[1];
737
738 eval {
739 local $SIG{__DIE__};
740 setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
741 if $_[0]{fh};
742 };
743}
744
745=item $handle->oobinline ($boolean)
746
747Enables or disables the C<oobinline> setting (see constructor argument of
748the same name for details).
749
750=cut
751
752sub oobinline {
753 $_[0]{oobinline} = $_[1];
754
755 eval {
756 local $SIG{__DIE__};
757 setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_OOBINLINE (), int $_[1]
758 if $_[0]{fh};
759 };
760}
761
762=item $handle->keepalive ($boolean)
763
764Enables or disables the C<keepalive> setting (see constructor argument of
765the same name for details).
766
767=cut
768
769sub keepalive {
770 $_[0]{keepalive} = $_[1];
771
772 eval {
773 local $SIG{__DIE__};
774 setsockopt $_[0]{fh}, Socket::SOL_SOCKET (), Socket::SO_KEEPALIVE (), int $_[1]
775 if $_[0]{fh};
776 };
777}
778
779=item $handle->on_starttls ($cb)
780
781Replace the current C<on_starttls> callback (see the C<on_starttls> constructor argument).
782
783=cut
784
785sub on_starttls {
786 $_[0]{on_starttls} = $_[1];
787}
788
789=item $handle->on_stoptls ($cb)
790
791Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
792
793=cut
794
795sub on_stoptls {
796 $_[0]{on_stoptls} = $_[1];
797}
798
799=item $handle->rbuf_max ($max_octets)
800
801Configures the C<rbuf_max> setting (C<undef> disables it).
802
803=item $handle->wbuf_max ($max_octets)
804
805Configures the C<wbuf_max> setting (C<undef> disables it).
806
807=cut
808
809sub rbuf_max {
810 $_[0]{rbuf_max} = $_[1];
811}
812
813sub wbuf_max {
814 $_[0]{wbuf_max} = $_[1];
815}
816
817#############################################################################
818
819=item $handle->timeout ($seconds)
820
821=item $handle->rtimeout ($seconds)
822
823=item $handle->wtimeout ($seconds)
824
825Configures (or disables) the inactivity timeout.
826
827The timeout will be checked instantly, so this method might destroy the
828handle before it returns.
829
830=item $handle->timeout_reset
831
832=item $handle->rtimeout_reset
833
834=item $handle->wtimeout_reset
835
836Reset the activity timeout, as if data was received or sent.
837
838These methods are cheap to call.
839
840=cut
841
842for my $dir ("", "r", "w") {
843 my $timeout = "${dir}timeout";
844 my $tw = "_${dir}tw";
845 my $on_timeout = "on_${dir}timeout";
846 my $activity = "_${dir}activity";
847 my $cb;
848
849 *$on_timeout = sub {
850 $_[0]{$on_timeout} = $_[1];
851 };
852
853 *$timeout = sub {
854 my ($self, $new_value) = @_;
855
856 $new_value >= 0
857 or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
858
859 $self->{$timeout} = $new_value;
860 delete $self->{$tw}; &$cb;
861 };
862
863 *{"${dir}timeout_reset"} = sub {
864 $_[0]{$activity} = AE::now;
865 };
866
867 # main workhorse:
868 # reset the timeout watcher, as neccessary
869 # also check for time-outs
870 $cb = sub {
871 my ($self) = @_;
872
873 if ($self->{$timeout} && $self->{fh}) {
874 my $NOW = AE::now;
875
876 # when would the timeout trigger?
877 my $after = $self->{$activity} + $self->{$timeout} - $NOW;
878
879 # now or in the past already?
880 if ($after <= 0) {
881 $self->{$activity} = $NOW;
882
883 if ($self->{$on_timeout}) {
884 $self->{$on_timeout}($self);
885 } else {
886 $self->_error (Errno::ETIMEDOUT);
887 }
888
889 # callback could have changed timeout value, optimise
890 return unless $self->{$timeout};
891
892 # calculate new after
893 $after = $self->{$timeout};
894 }
895
896 Scalar::Util::weaken $self;
897 return unless $self; # ->error could have destroyed $self
898
899 $self->{$tw} ||= AE::timer $after, 0, sub {
900 delete $self->{$tw};
901 $cb->($self);
902 };
903 } else {
904 delete $self->{$tw};
905 }
906 }
907}
908
267############################################################################# 909#############################################################################
268 910
269=back 911=back
270 912
271=head2 WRITE QUEUE 913=head2 WRITE QUEUE
275 917
276The write queue is very simple: you can add data to its end, and 918The write queue is very simple: you can add data to its end, and
277AnyEvent::Handle will automatically try to get rid of it for you. 919AnyEvent::Handle will automatically try to get rid of it for you.
278 920
279When data could be written and the write buffer is shorter then the low 921When data could be written and the write buffer is shorter then the low
280water mark, the C<on_drain> callback will be invoked. 922water mark, the C<on_drain> callback will be invoked once.
281 923
282=over 4 924=over 4
283 925
284=item $handle->on_drain ($cb) 926=item $handle->on_drain ($cb)
285 927
286Sets the C<on_drain> callback or clears it (see the description of 928Sets the C<on_drain> callback or clears it (see the description of
287C<on_drain> in the constructor). 929C<on_drain> in the constructor).
288 930
931This method may invoke callbacks (and therefore the handle might be
932destroyed after it returns).
933
289=cut 934=cut
290 935
291sub on_drain { 936sub on_drain {
292 my ($self, $cb) = @_; 937 my ($self, $cb) = @_;
293 938
294 $self->{on_drain} = $cb; 939 $self->{on_drain} = $cb;
295 940
296 $cb->($self) 941 $cb->($self)
297 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 942 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
298} 943}
299 944
300=item $handle->push_write ($data) 945=item $handle->push_write ($data)
301 946
302Queues the given scalar to be written. You can push as much data as you 947Queues the given scalar to be written. You can push as much data as
303want (only limited by the available memory), as C<AnyEvent::Handle> 948you want (only limited by the available memory and C<wbuf_max>), as
304buffers it independently of the kernel. 949C<AnyEvent::Handle> buffers it independently of the kernel.
950
951This method may invoke callbacks (and therefore the handle might be
952destroyed after it returns).
305 953
306=cut 954=cut
307 955
308sub _drain_wbuf { 956sub _drain_wbuf {
309 my ($self) = @_; 957 my ($self) = @_;
313 Scalar::Util::weaken $self; 961 Scalar::Util::weaken $self;
314 962
315 my $cb = sub { 963 my $cb = sub {
316 my $len = syswrite $self->{fh}, $self->{wbuf}; 964 my $len = syswrite $self->{fh}, $self->{wbuf};
317 965
318 if ($len >= 0) { 966 if (defined $len) {
319 substr $self->{wbuf}, 0, $len, ""; 967 substr $self->{wbuf}, 0, $len, "";
320 968
969 $self->{_activity} = $self->{_wactivity} = AE::now;
970
321 $self->{on_drain}($self) 971 $self->{on_drain}($self)
322 if $self->{low_water_mark} >= length $self->{wbuf} 972 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
323 && $self->{on_drain}; 973 && $self->{on_drain};
324 974
325 delete $self->{_ww} unless length $self->{wbuf}; 975 delete $self->{_ww} unless length $self->{wbuf};
326 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { 976 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
327 $self->error; 977 $self->_error ($!, 1);
328 } 978 }
329 }; 979 };
330 980
331 # try to write data immediately 981 # try to write data immediately
332 $cb->(); 982 $cb->() unless $self->{autocork};
333 983
334 # if still data left in wbuf, we need to poll 984 # if still data left in wbuf, we need to poll
335 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb) 985 $self->{_ww} = AE::io $self->{fh}, 1, $cb
336 if length $self->{wbuf}; 986 if length $self->{wbuf};
987
988 if (
989 defined $self->{wbuf_max}
990 && $self->{wbuf_max} < length $self->{wbuf}
991 ) {
992 $self->_error (Errno::ENOSPC, 1), return;
993 }
337 }; 994 };
338} 995}
339 996
340our %WH; 997our %WH;
341 998
999# deprecated
342sub register_write_type($$) { 1000sub register_write_type($$) {
343 $WH{$_[0]} = $_[1]; 1001 $WH{$_[0]} = $_[1];
344} 1002}
345 1003
346sub push_write { 1004sub push_write {
347 my $self = shift; 1005 my $self = shift;
348 1006
349 if (@_ > 1) { 1007 if (@_ > 1) {
350 my $type = shift; 1008 my $type = shift;
351 1009
1010 @_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
352 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 1011 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
353 ->($self, @_); 1012 ->($self, @_);
354 } 1013 }
355 1014
1015 # we downgrade here to avoid hard-to-track-down bugs,
1016 # and diagnose the problem earlier and better.
1017
356 if ($self->{filter_w}) { 1018 if ($self->{tls}) {
357 $self->{filter_w}->($self, \$_[0]); 1019 utf8::downgrade $self->{_tls_wbuf} .= $_[0];
1020 &_dotls ($self) if $self->{fh};
358 } else { 1021 } else {
359 $self->{wbuf} .= $_[0]; 1022 utf8::downgrade $self->{wbuf} .= $_[0];
360 $self->_drain_wbuf; 1023 $self->_drain_wbuf if $self->{fh};
361 } 1024 }
362} 1025}
363 1026
364=item $handle->push_write (type => @args) 1027=item $handle->push_write (type => @args)
365 1028
366=item $handle->unshift_write (type => @args)
367
368Instead of formatting your data yourself, you can also let this module do 1029Instead of formatting your data yourself, you can also let this module
369the job by specifying a type and type-specific arguments. 1030do the job by specifying a type and type-specific arguments. You
1031can also specify the (fully qualified) name of a package, in which
1032case AnyEvent tries to load the package and then expects to find the
1033C<anyevent_write_type> function inside (see "custom write types", below).
370 1034
371Predefined types are (if you have ideas for additional types, feel free to 1035Predefined types are (if you have ideas for additional types, feel free to
372drop by and tell us): 1036drop by and tell us):
373 1037
374=over 4 1038=over 4
376=item netstring => $string 1040=item netstring => $string
377 1041
378Formats the given value as netstring 1042Formats the given value as netstring
379(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them). 1043(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
380 1044
381=back
382
383=cut 1045=cut
384 1046
385register_write_type netstring => sub { 1047register_write_type netstring => sub {
386 my ($self, $string) = @_; 1048 my ($self, $string) = @_;
387 1049
388 sprintf "%d:%s,", (length $string), $string 1050 (length $string) . ":$string,"
1051};
1052
1053=item packstring => $format, $data
1054
1055An octet string prefixed with an encoded length. The encoding C<$format>
1056uses the same format as a Perl C<pack> format, but must specify a single
1057integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1058optional C<!>, C<< < >> or C<< > >> modifier).
1059
1060=cut
1061
1062register_write_type packstring => sub {
1063 my ($self, $format, $string) = @_;
1064
1065 pack "$format/a*", $string
389}; 1066};
390 1067
391=item json => $array_or_hashref 1068=item json => $array_or_hashref
392 1069
393Encodes the given hash or array reference into a JSON object. Unless you 1070Encodes the given hash or array reference into a JSON object. Unless you
394provide your own JSON object, this means it will be encoded to JSON text 1071provide your own JSON object, this means it will be encoded to JSON text
395in UTF-8. 1072in UTF-8.
396 1073
1074The default encoder might or might not handle every type of JSON value -
1075it might be limited to arrays and objects for security reasons. See the
1076C<json> constructor attribute for more details.
1077
397JSON objects (and arrays) are self-delimiting, so you can write JSON at 1078JSON objects (and arrays) are self-delimiting, so if you only use arrays
398one end of a handle and read them at the other end without using any 1079and hashes, you can write JSON at one end of a handle and read them at the
399additional framing. 1080other end without using any additional framing.
400 1081
401The generated JSON text is guaranteed not to contain any newlines: While 1082The JSON text generated by the default encoder is guaranteed not to
402this module doesn't need delimiters after or between JSON texts to be 1083contain any newlines: While this module doesn't need delimiters after or
403able to read them, many other languages depend on that. 1084between JSON texts to be able to read them, many other languages depend on
1085them.
404 1086
405A simple RPC protocol that interoperates easily with others is to send 1087A simple RPC protocol that interoperates easily with other languages is
406JSON arrays (or objects, although arrays are usually the better choice as 1088to send JSON arrays (or objects, although arrays are usually the better
407they mimic how function argument passing works) and a newline after each 1089choice as they mimic how function argument passing works) and a newline
408JSON text: 1090after each JSON text:
409 1091
410 $handle->push_write (json => ["method", "arg1", "arg2"]); # whatever 1092 $handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
411 $handle->push_write ("\012"); 1093 $handle->push_write ("\012");
412 1094
413An AnyEvent::Handle receiver would simply use the C<json> read type and 1095An AnyEvent::Handle receiver would simply use the C<json> read type and
416 $handle->push_read (json => sub { my $array = $_[1]; ... }); 1098 $handle->push_read (json => sub { my $array = $_[1]; ... });
417 1099
418Other languages could read single lines terminated by a newline and pass 1100Other languages could read single lines terminated by a newline and pass
419this line into their JSON decoder of choice. 1101this line into their JSON decoder of choice.
420 1102
1103=item cbor => $perl_scalar
1104
1105Encodes the given scalar into a CBOR value. Unless you provide your own
1106L<CBOR::XS> object, this means it will be encoded to a CBOR string not
1107using any extensions, if possible.
1108
1109CBOR values are self-delimiting, so you can write CBOR at one end of
1110a handle and read them at the other end without using any additional
1111framing.
1112
1113A simple nd very very fast RPC protocol that interoperates with
1114other languages is to send CBOR and receive CBOR values (arrays are
1115recommended):
1116
1117 $handle->push_write (cbor => ["method", "arg1", "arg2"]); # whatever
1118
1119An AnyEvent::Handle receiver would simply use the C<cbor> read type:
1120
1121 $handle->push_read (cbor => sub { my $array = $_[1]; ... });
1122
421=cut 1123=cut
1124
1125sub json_coder() {
1126 eval { require JSON::XS; JSON::XS->new->utf8 }
1127 || do { require JSON::PP; JSON::PP->new->utf8 }
1128}
422 1129
423register_write_type json => sub { 1130register_write_type json => sub {
424 my ($self, $ref) = @_; 1131 my ($self, $ref) = @_;
425 1132
426 require JSON; 1133 ($self->{json} ||= json_coder)
427 1134 ->encode ($ref)
428 $self->{json} ? $self->{json}->encode ($ref)
429 : JSON::encode_json ($ref)
430}; 1135};
431 1136
432=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args) 1137sub cbor_coder() {
1138 require CBOR::XS;
1139 CBOR::XS->new
1140}
433 1141
434This function (not method) lets you add your own types to C<push_write>. 1142register_write_type cbor => sub {
1143 my ($self, $scalar) = @_;
1144
1145 ($self->{cbor} ||= cbor_coder)
1146 ->encode ($scalar)
1147};
1148
1149=item storable => $reference
1150
1151Freezes the given reference using L<Storable> and writes it to the
1152handle. Uses the C<nfreeze> format.
1153
1154=cut
1155
1156register_write_type storable => sub {
1157 my ($self, $ref) = @_;
1158
1159 require Storable unless $Storable::VERSION;
1160
1161 pack "w/a*", Storable::nfreeze ($ref)
1162};
1163
1164=back
1165
1166=item $handle->push_shutdown
1167
1168Sometimes you know you want to close the socket after writing your data
1169before it was actually written. One way to do that is to replace your
1170C<on_drain> handler by a callback that shuts down the socket (and set
1171C<low_water_mark> to C<0>). This method is a shorthand for just that, and
1172replaces the C<on_drain> callback with:
1173
1174 sub { shutdown $_[0]{fh}, 1 }
1175
1176This simply shuts down the write side and signals an EOF condition to the
1177the peer.
1178
1179You can rely on the normal read queue and C<on_eof> handling
1180afterwards. This is the cleanest way to close a connection.
1181
1182This method may invoke callbacks (and therefore the handle might be
1183destroyed after it returns).
1184
1185=cut
1186
1187sub push_shutdown {
1188 my ($self) = @_;
1189
1190 delete $self->{low_water_mark};
1191 $self->on_drain (sub { shutdown $_[0]{fh}, 1 });
1192}
1193
1194=item custom write types - Package::anyevent_write_type $handle, @args
1195
1196Instead of one of the predefined types, you can also specify the name of
1197a package. AnyEvent will try to load the package and then expects to find
1198a function named C<anyevent_write_type> inside. If it isn't found, it
1199progressively tries to load the parent package until it either finds the
1200function (good) or runs out of packages (bad).
1201
435Whenever the given C<type> is used, C<push_write> will invoke the code 1202Whenever the given C<type> is used, C<push_write> will the function with
436reference with the handle object and the remaining arguments. 1203the handle object and the remaining arguments.
437 1204
438The code reference is supposed to return a single octet string that will 1205The function is supposed to return a single octet string that will be
439be appended to the write buffer. 1206appended to the write buffer, so you can mentally treat this function as a
1207"arguments to on-the-wire-format" converter.
440 1208
441Note that this is a function, and all types registered this way will be 1209Example: implement a custom write type C<join> that joins the remaining
442global, so try to use unique names. 1210arguments using the first one.
1211
1212 $handle->push_write (My::Type => " ", 1,2,3);
1213
1214 # uses the following package, which can be defined in the "My::Type" or in
1215 # the "My" modules to be auto-loaded, or just about anywhere when the
1216 # My::Type::anyevent_write_type is defined before invoking it.
1217
1218 package My::Type;
1219
1220 sub anyevent_write_type {
1221 my ($handle, $delim, @args) = @_;
1222
1223 join $delim, @args
1224 }
443 1225
444=cut 1226=cut
445 1227
446############################################################################# 1228#############################################################################
447 1229
456ways, the "simple" way, using only C<on_read> and the "complex" way, using 1238ways, the "simple" way, using only C<on_read> and the "complex" way, using
457a queue. 1239a queue.
458 1240
459In the simple case, you just install an C<on_read> callback and whenever 1241In the simple case, you just install an C<on_read> callback and whenever
460new data arrives, it will be called. You can then remove some data (if 1242new data arrives, it will be called. You can then remove some data (if
461enough is there) from the read buffer (C<< $handle->rbuf >>) if you want 1243enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
462or not. 1244leave the data there if you want to accumulate more (e.g. when only a
1245partial message has been received so far), or change the read queue with
1246e.g. C<push_read>.
463 1247
464In the more complex case, you want to queue multiple callbacks. In this 1248In the more complex case, you want to queue multiple callbacks. In this
465case, AnyEvent::Handle will call the first queued callback each time new 1249case, AnyEvent::Handle will call the first queued callback each time new
466data arrives and removes it when it has done its job (see C<push_read>, 1250data arrives (also the first time it is queued) and remove it when it has
467below). 1251done its job (see C<push_read>, below).
468 1252
469This way you can, for example, push three line-reads, followed by reading 1253This way you can, for example, push three line-reads, followed by reading
470a chunk of data, and AnyEvent::Handle will execute them in order. 1254a chunk of data, and AnyEvent::Handle will execute them in order.
471 1255
472Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by 1256Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
473the specified number of bytes which give an XML datagram. 1257the specified number of bytes which give an XML datagram.
474 1258
475 # in the default state, expect some header bytes 1259 # in the default state, expect some header bytes
476 $handle->on_read (sub { 1260 $handle->on_read (sub {
477 # some data is here, now queue the length-header-read (4 octets) 1261 # some data is here, now queue the length-header-read (4 octets)
478 shift->unshift_read_chunk (4, sub { 1262 shift->unshift_read (chunk => 4, sub {
479 # header arrived, decode 1263 # header arrived, decode
480 my $len = unpack "N", $_[1]; 1264 my $len = unpack "N", $_[1];
481 1265
482 # now read the payload 1266 # now read the payload
483 shift->unshift_read_chunk ($len, sub { 1267 shift->unshift_read (chunk => $len, sub {
484 my $xml = $_[1]; 1268 my $xml = $_[1];
485 # handle xml 1269 # handle xml
486 }); 1270 });
487 }); 1271 });
488 }); 1272 });
489 1273
490Example 2: Implement a client for a protocol that replies either with 1274Example 2: Implement a client for a protocol that replies either with "OK"
491"OK" and another line or "ERROR" for one request, and 64 bytes for the 1275and another line or "ERROR" for the first request that is sent, and 64
492second request. Due tot he availability of a full queue, we can just 1276bytes for the second request. Due to the availability of a queue, we can
493pipeline sending both requests and manipulate the queue as necessary in 1277just pipeline sending both requests and manipulate the queue as necessary
494the callbacks: 1278in the callbacks.
495 1279
496 # request one 1280When the first callback is called and sees an "OK" response, it will
1281C<unshift> another line-read. This line-read will be queued I<before> the
128264-byte chunk callback.
1283
1284 # request one, returns either "OK + extra line" or "ERROR"
497 $handle->push_write ("request 1\015\012"); 1285 $handle->push_write ("request 1\015\012");
498 1286
499 # we expect "ERROR" or "OK" as response, so push a line read 1287 # we expect "ERROR" or "OK" as response, so push a line read
500 $handle->push_read_line (sub { 1288 $handle->push_read (line => sub {
501 # if we got an "OK", we have to _prepend_ another line, 1289 # if we got an "OK", we have to _prepend_ another line,
502 # so it will be read before the second request reads its 64 bytes 1290 # so it will be read before the second request reads its 64 bytes
503 # which are already in the queue when this callback is called 1291 # which are already in the queue when this callback is called
504 # we don't do this in case we got an error 1292 # we don't do this in case we got an error
505 if ($_[1] eq "OK") { 1293 if ($_[1] eq "OK") {
506 $_[0]->unshift_read_line (sub { 1294 $_[0]->unshift_read (line => sub {
507 my $response = $_[1]; 1295 my $response = $_[1];
508 ... 1296 ...
509 }); 1297 });
510 } 1298 }
511 }); 1299 });
512 1300
513 # request two 1301 # request two, simply returns 64 octets
514 $handle->push_write ("request 2\015\012"); 1302 $handle->push_write ("request 2\015\012");
515 1303
516 # simply read 64 bytes, always 1304 # simply read 64 bytes, always
517 $handle->push_read_chunk (64, sub { 1305 $handle->push_read (chunk => 64, sub {
518 my $response = $_[1]; 1306 my $response = $_[1];
519 ... 1307 ...
520 }); 1308 });
521 1309
522=over 4 1310=over 4
523 1311
524=cut 1312=cut
525 1313
526sub _drain_rbuf { 1314sub _drain_rbuf {
527 my ($self) = @_; 1315 my ($self) = @_;
1316
1317 # avoid recursion
1318 return if $self->{_skip_drain_rbuf};
1319 local $self->{_skip_drain_rbuf} = 1;
1320
1321 while () {
1322 # we need to use a separate tls read buffer, as we must not receive data while
1323 # we are draining the buffer, and this can only happen with TLS.
1324 $self->{rbuf} .= delete $self->{_tls_rbuf}
1325 if exists $self->{_tls_rbuf};
1326
1327 my $len = length $self->{rbuf};
1328
1329 if (my $cb = shift @{ $self->{_queue} }) {
1330 unless ($cb->($self)) {
1331 # no progress can be made
1332 # (not enough data and no data forthcoming)
1333 $self->_error (Errno::EPIPE, 1), return
1334 if $self->{_eof};
1335
1336 unshift @{ $self->{_queue} }, $cb;
1337 last;
1338 }
1339 } elsif ($self->{on_read}) {
1340 last unless $len;
1341
1342 $self->{on_read}($self);
1343
1344 if (
1345 $len == length $self->{rbuf} # if no data has been consumed
1346 && !@{ $self->{_queue} } # and the queue is still empty
1347 && $self->{on_read} # but we still have on_read
1348 ) {
1349 # no further data will arrive
1350 # so no progress can be made
1351 $self->_error (Errno::EPIPE, 1), return
1352 if $self->{_eof};
1353
1354 last; # more data might arrive
1355 }
1356 } else {
1357 # read side becomes idle
1358 delete $self->{_rw} unless $self->{tls};
1359 last;
1360 }
1361 }
1362
1363 if ($self->{_eof}) {
1364 $self->{on_eof}
1365 ? $self->{on_eof}($self)
1366 : $self->_error (0, 1, "Unexpected end-of-file");
1367
1368 return;
1369 }
528 1370
529 if ( 1371 if (
530 defined $self->{rbuf_max} 1372 defined $self->{rbuf_max}
531 && $self->{rbuf_max} < length $self->{rbuf} 1373 && $self->{rbuf_max} < length $self->{rbuf}
532 ) { 1374 ) {
533 $! = &Errno::ENOSPC; 1375 $self->_error (Errno::ENOSPC, 1), return;
534 $self->error;
535 } 1376 }
536 1377
537 return if $self->{in_drain}; 1378 # may need to restart read watcher
538 local $self->{in_drain} = 1; 1379 unless ($self->{_rw}) {
539 1380 $self->start_read
540 while (my $len = length $self->{rbuf}) { 1381 if $self->{on_read} || @{ $self->{_queue} };
541 no strict 'refs';
542 if (my $cb = shift @{ $self->{_queue} }) {
543 unless ($cb->($self)) {
544 if ($self->{_eof}) {
545 # no progress can be made (not enough data and no data forthcoming)
546 $! = &Errno::EPIPE;
547 $self->error;
548 }
549
550 unshift @{ $self->{_queue} }, $cb;
551 return;
552 }
553 } elsif ($self->{on_read}) {
554 $self->{on_read}($self);
555
556 if (
557 $self->{_eof} # if no further data will arrive
558 && $len == length $self->{rbuf} # and no data has been consumed
559 && !@{ $self->{_queue} } # and the queue is still empty
560 && $self->{on_read} # and we still want to read data
561 ) {
562 # then no progress can be made
563 $! = &Errno::EPIPE;
564 $self->error;
565 }
566 } else {
567 # read side becomes idle
568 delete $self->{_rw};
569 return;
570 }
571 }
572
573 if ($self->{_eof}) {
574 $self->_shutdown;
575 $self->{on_eof}($self)
576 if $self->{on_eof};
577 } 1382 }
578} 1383}
579 1384
580=item $handle->on_read ($cb) 1385=item $handle->on_read ($cb)
581 1386
582This replaces the currently set C<on_read> callback, or clears it (when 1387This replaces the currently set C<on_read> callback, or clears it (when
583the new callback is C<undef>). See the description of C<on_read> in the 1388the new callback is C<undef>). See the description of C<on_read> in the
584constructor. 1389constructor.
585 1390
1391This method may invoke callbacks (and therefore the handle might be
1392destroyed after it returns).
1393
586=cut 1394=cut
587 1395
588sub on_read { 1396sub on_read {
589 my ($self, $cb) = @_; 1397 my ($self, $cb) = @_;
590 1398
591 $self->{on_read} = $cb; 1399 $self->{on_read} = $cb;
1400 $self->_drain_rbuf if $cb;
592} 1401}
593 1402
594=item $handle->rbuf 1403=item $handle->rbuf
595 1404
596Returns the read buffer (as a modifiable lvalue). 1405Returns the read buffer (as a modifiable lvalue). You can also access the
1406read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
1407much faster, and no less clean).
597 1408
598You can access the read buffer directly as the C<< ->{rbuf} >> member, if 1409The only operation allowed on the read buffer (apart from looking at it)
599you want. 1410is removing data from its beginning. Otherwise modifying or appending to
1411it is not allowed and will lead to hard-to-track-down bugs.
600 1412
601NOTE: The read buffer should only be used or modified if the C<on_read>, 1413NOTE: The read buffer should only be used or modified in the C<on_read>
602C<push_read> or C<unshift_read> methods are used. The other read methods 1414callback or when C<push_read> or C<unshift_read> are used with a single
603automatically manage the read buffer. 1415callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
1416will manage the read buffer on their own.
604 1417
605=cut 1418=cut
606 1419
607sub rbuf : lvalue { 1420sub rbuf : lvalue {
608 $_[0]{rbuf} 1421 $_[0]{rbuf}
625 1438
626If enough data was available, then the callback must remove all data it is 1439If enough data was available, then the callback must remove all data it is
627interested in (which can be none at all) and return a true value. After returning 1440interested in (which can be none at all) and return a true value. After returning
628true, it will be removed from the queue. 1441true, it will be removed from the queue.
629 1442
1443These methods may invoke callbacks (and therefore the handle might be
1444destroyed after it returns).
1445
630=cut 1446=cut
631 1447
632our %RH; 1448our %RH;
633 1449
634sub register_read_type($$) { 1450sub register_read_type($$) {
640 my $cb = pop; 1456 my $cb = pop;
641 1457
642 if (@_) { 1458 if (@_) {
643 my $type = shift; 1459 my $type = shift;
644 1460
1461 $cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
645 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read") 1462 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
646 ->($self, $cb, @_); 1463 ->($self, $cb, @_);
647 } 1464 }
648 1465
649 push @{ $self->{_queue} }, $cb; 1466 push @{ $self->{_queue} }, $cb;
650 $self->_drain_rbuf; 1467 $self->_drain_rbuf;
655 my $cb = pop; 1472 my $cb = pop;
656 1473
657 if (@_) { 1474 if (@_) {
658 my $type = shift; 1475 my $type = shift;
659 1476
1477 $cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
660 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read") 1478 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
661 ->($self, $cb, @_); 1479 ->($self, $cb, @_);
662 } 1480 }
663
664 1481
665 unshift @{ $self->{_queue} }, $cb; 1482 unshift @{ $self->{_queue} }, $cb;
666 $self->_drain_rbuf; 1483 $self->_drain_rbuf;
667} 1484}
668 1485
670 1487
671=item $handle->unshift_read (type => @args, $cb) 1488=item $handle->unshift_read (type => @args, $cb)
672 1489
673Instead of providing a callback that parses the data itself you can chose 1490Instead of providing a callback that parses the data itself you can chose
674between a number of predefined parsing formats, for chunks of data, lines 1491between a number of predefined parsing formats, for chunks of data, lines
675etc. 1492etc. You can also specify the (fully qualified) name of a package, in
1493which case AnyEvent tries to load the package and then expects to find the
1494C<anyevent_read_type> function inside (see "custom read types", below).
676 1495
677Predefined types are (if you have ideas for additional types, feel free to 1496Predefined types are (if you have ideas for additional types, feel free to
678drop by and tell us): 1497drop by and tell us):
679 1498
680=over 4 1499=over 4
686data. 1505data.
687 1506
688Example: read 2 bytes. 1507Example: read 2 bytes.
689 1508
690 $handle->push_read (chunk => 2, sub { 1509 $handle->push_read (chunk => 2, sub {
691 warn "yay ", unpack "H*", $_[1]; 1510 say "yay " . unpack "H*", $_[1];
692 }); 1511 });
693 1512
694=cut 1513=cut
695 1514
696register_read_type chunk => sub { 1515register_read_type chunk => sub {
701 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); 1520 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
702 1 1521 1
703 } 1522 }
704}; 1523};
705 1524
706# compatibility with older API
707sub push_read_chunk {
708 $_[0]->push_read (chunk => $_[1], $_[2]);
709}
710
711sub unshift_read_chunk {
712 $_[0]->unshift_read (chunk => $_[1], $_[2]);
713}
714
715=item line => [$eol, ]$cb->($handle, $line, $eol) 1525=item line => [$eol, ]$cb->($handle, $line, $eol)
716 1526
717The callback will be called only once a full line (including the end of 1527The callback will be called only once a full line (including the end of
718line marker, C<$eol>) has been read. This line (excluding the end of line 1528line marker, C<$eol>) has been read. This line (excluding the end of line
719marker) will be passed to the callback as second argument (C<$line>), and 1529marker) will be passed to the callback as second argument (C<$line>), and
734=cut 1544=cut
735 1545
736register_read_type line => sub { 1546register_read_type line => sub {
737 my ($self, $cb, $eol) = @_; 1547 my ($self, $cb, $eol) = @_;
738 1548
739 $eol = qr|(\015?\012)| if @_ < 3; 1549 if (@_ < 3) {
740 $eol = quotemeta $eol unless ref $eol; 1550 # this is faster then the generic code below
741 $eol = qr|^(.*?)($eol)|s;
742
743 sub { 1551 sub {
744 $_[0]{rbuf} =~ s/$eol// or return; 1552 (my $pos = index $_[0]{rbuf}, "\012") >= 0
1553 or return;
745 1554
1555 (my $str = substr $_[0]{rbuf}, 0, $pos + 1, "") =~ s/(\015?\012)\Z// or die;
746 $cb->($_[0], $1, $2); 1556 $cb->($_[0], $str, "$1");
747 1
748 }
749};
750
751# compatibility with older API
752sub push_read_line {
753 my $self = shift;
754 $self->push_read (line => @_);
755}
756
757sub unshift_read_line {
758 my $self = shift;
759 $self->unshift_read (line => @_);
760}
761
762=item netstring => $cb->($handle, $string)
763
764A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
765
766Throws an error with C<$!> set to EBADMSG on format violations.
767
768=cut
769
770register_read_type netstring => sub {
771 my ($self, $cb) = @_;
772
773 sub {
774 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
775 if ($_[0]{rbuf} =~ /[^0-9]/) {
776 $! = &Errno::EBADMSG;
777 $self->error;
778 } 1557 1
779 return;
780 } 1558 }
1559 } else {
1560 $eol = quotemeta $eol unless ref $eol;
1561 $eol = qr|^(.*?)($eol)|s;
781 1562
782 my $len = $1; 1563 sub {
1564 $_[0]{rbuf} =~ s/$eol// or return;
783 1565
784 $self->unshift_read (chunk => $len, sub { 1566 $cb->($_[0], "$1", "$2");
785 my $string = $_[1];
786 $_[0]->unshift_read (chunk => 1, sub {
787 if ($_[1] eq ",") {
788 $cb->($_[0], $string);
789 } else {
790 $! = &Errno::EBADMSG;
791 $self->error;
792 }
793 }); 1567 1
794 }); 1568 }
795
796 1
797 } 1569 }
798}; 1570};
799 1571
800=item regex => $accept[, $reject[, $skip], $cb->($handle, $data) 1572=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
801 1573
821the receive buffer when neither C<$accept> nor C<$reject> match, 1593the receive buffer when neither C<$accept> nor C<$reject> match,
822and everything preceding and including the match will be accepted 1594and everything preceding and including the match will be accepted
823unconditionally. This is useful to skip large amounts of data that you 1595unconditionally. This is useful to skip large amounts of data that you
824know cannot be matched, so that the C<$accept> or C<$reject> regex do not 1596know cannot be matched, so that the C<$accept> or C<$reject> regex do not
825have to start matching from the beginning. This is purely an optimisation 1597have to start matching from the beginning. This is purely an optimisation
826and is usually worth only when you expect more than a few kilobytes. 1598and is usually worth it only when you expect more than a few kilobytes.
827 1599
828Example: expect a http header, which ends at C<\015\012\015\012>. Since we 1600Example: expect a http header, which ends at C<\015\012\015\012>. Since we
829expect the header to be very large (it isn't in practise, but...), we use 1601expect the header to be very large (it isn't in practice, but...), we use
830a skip regex to skip initial portions. The skip regex is tricky in that 1602a skip regex to skip initial portions. The skip regex is tricky in that
831it only accepts something not ending in either \015 or \012, as these are 1603it only accepts something not ending in either \015 or \012, as these are
832required for the accept regex. 1604required for the accept regex.
833 1605
834 $handle->push_read (regex => 1606 $handle->push_read (regex =>
847 1619
848 sub { 1620 sub {
849 # accept 1621 # accept
850 if ($$rbuf =~ $accept) { 1622 if ($$rbuf =~ $accept) {
851 $data .= substr $$rbuf, 0, $+[0], ""; 1623 $data .= substr $$rbuf, 0, $+[0], "";
852 $cb->($self, $data); 1624 $cb->($_[0], $data);
853 return 1; 1625 return 1;
854 } 1626 }
855 1627
856 # reject 1628 # reject
857 if ($reject && $$rbuf =~ $reject) { 1629 if ($reject && $$rbuf =~ $reject) {
858 $! = &Errno::EBADMSG; 1630 $_[0]->_error (Errno::EBADMSG);
859 $self->error;
860 } 1631 }
861 1632
862 # skip 1633 # skip
863 if ($skip && $$rbuf =~ $skip) { 1634 if ($skip && $$rbuf =~ $skip) {
864 $data .= substr $$rbuf, 0, $+[0], ""; 1635 $data .= substr $$rbuf, 0, $+[0], "";
866 1637
867 () 1638 ()
868 } 1639 }
869}; 1640};
870 1641
1642=item netstring => $cb->($handle, $string)
1643
1644A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
1645
1646Throws an error with C<$!> set to EBADMSG on format violations.
1647
1648=cut
1649
1650register_read_type netstring => sub {
1651 my ($self, $cb) = @_;
1652
1653 sub {
1654 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1655 if ($_[0]{rbuf} =~ /[^0-9]/) {
1656 $_[0]->_error (Errno::EBADMSG);
1657 }
1658 return;
1659 }
1660
1661 my $len = $1;
1662
1663 $_[0]->unshift_read (chunk => $len, sub {
1664 my $string = $_[1];
1665 $_[0]->unshift_read (chunk => 1, sub {
1666 if ($_[1] eq ",") {
1667 $cb->($_[0], $string);
1668 } else {
1669 $_[0]->_error (Errno::EBADMSG);
1670 }
1671 });
1672 });
1673
1674 1
1675 }
1676};
1677
1678=item packstring => $format, $cb->($handle, $string)
1679
1680An octet string prefixed with an encoded length. The encoding C<$format>
1681uses the same format as a Perl C<pack> format, but must specify a single
1682integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1683optional C<!>, C<< < >> or C<< > >> modifier).
1684
1685For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1686EPP uses a prefix of C<N> (4 octtes).
1687
1688Example: read a block of data prefixed by its length in BER-encoded
1689format (very efficient).
1690
1691 $handle->push_read (packstring => "w", sub {
1692 my ($handle, $data) = @_;
1693 });
1694
1695=cut
1696
1697register_read_type packstring => sub {
1698 my ($self, $cb, $format) = @_;
1699
1700 sub {
1701 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1702 defined (my $len = eval { unpack $format, $_[0]{rbuf} })
1703 or return;
1704
1705 $format = length pack $format, $len;
1706
1707 # bypass unshift if we already have the remaining chunk
1708 if ($format + $len <= length $_[0]{rbuf}) {
1709 my $data = substr $_[0]{rbuf}, $format, $len;
1710 substr $_[0]{rbuf}, 0, $format + $len, "";
1711 $cb->($_[0], $data);
1712 } else {
1713 # remove prefix
1714 substr $_[0]{rbuf}, 0, $format, "";
1715
1716 # read remaining chunk
1717 $_[0]->unshift_read (chunk => $len, $cb);
1718 }
1719
1720 1
1721 }
1722};
1723
871=item json => $cb->($handle, $hash_or_arrayref) 1724=item json => $cb->($handle, $hash_or_arrayref)
872 1725
873Reads a JSON object or array, decodes it and passes it to the callback. 1726Reads a JSON object or array, decodes it and passes it to the
1727callback. When a parse error occurs, an C<EBADMSG> error will be raised.
874 1728
875If a C<json> object was passed to the constructor, then that will be used 1729If a C<json> object was passed to the constructor, then that will be
876for the final decode, otherwise it will create a JSON coder expecting UTF-8. 1730used for the final decode, otherwise it will create a L<JSON::XS> or
1731L<JSON::PP> coder object expecting UTF-8.
877 1732
878This read type uses the incremental parser available with JSON version 1733This read type uses the incremental parser available with JSON version
8792.09 (and JSON::XS version 2.2) and above. You have to provide a 17342.09 (and JSON::XS version 2.2) and above.
880dependency on your own: this module will load the JSON module, but
881AnyEvent does not depend on it itself.
882 1735
883Since JSON texts are fully self-delimiting, the C<json> read and write 1736Since JSON texts are fully self-delimiting, the C<json> read and write
884types are an ideal simple RPC protocol: just exchange JSON datagrams. See 1737types are an ideal simple RPC protocol: just exchange JSON datagrams. See
885the C<json> write type description, above, for an actual example. 1738the C<json> write type description, above, for an actual example.
886 1739
887=cut 1740=cut
888 1741
889register_read_type json => sub { 1742register_read_type json => sub {
890 my ($self, $cb, $accept, $reject, $skip) = @_; 1743 my ($self, $cb) = @_;
891 1744
892 require JSON; 1745 my $json = $self->{json} ||= json_coder;
893 1746
894 my $data; 1747 my $data;
895 my $rbuf = \$self->{rbuf};
896
897 my $json = $self->{json} ||= JSON->new->utf8;
898 1748
899 sub { 1749 sub {
900 my $ref = $json->incr_parse ($self->{rbuf}); 1750 my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
901 1751
902 if ($ref) { 1752 if ($ref) {
903 $self->{rbuf} = $json->incr_text; 1753 $_[0]{rbuf} = $json->incr_text;
904 $json->incr_text = ""; 1754 $json->incr_text = "";
905 $cb->($self, $ref); 1755 $cb->($_[0], $ref);
906 1756
907 1 1757 1
1758 } elsif ($@) {
1759 # error case
1760 $json->incr_skip;
1761
1762 $_[0]{rbuf} = $json->incr_text;
1763 $json->incr_text = "";
1764
1765 $_[0]->_error (Errno::EBADMSG);
1766
1767 ()
908 } else { 1768 } else {
909 $self->{rbuf} = ""; 1769 $_[0]{rbuf} = "";
1770
910 () 1771 ()
911 } 1772 }
912 } 1773 }
913}; 1774};
914 1775
1776=item cbor => $cb->($handle, $scalar)
1777
1778Reads a CBOR value, decodes it and passes it to the callback. When a parse
1779error occurs, an C<EBADMSG> error will be raised.
1780
1781If a L<CBOR::XS> object was passed to the constructor, then that will be
1782used for the final decode, otherwise it will create a CBOR coder without
1783enabling any options.
1784
1785You have to provide a dependency to L<CBOR::XS> on your own: this module
1786will load the L<CBOR::XS> module, but AnyEvent does not depend on it
1787itself.
1788
1789Since CBOR values are fully self-delimiting, the C<cbor> read and write
1790types are an ideal simple RPC protocol: just exchange CBOR datagrams. See
1791the C<cbor> write type description, above, for an actual example.
1792
1793=cut
1794
1795register_read_type cbor => sub {
1796 my ($self, $cb) = @_;
1797
1798 my $cbor = $self->{cbor} ||= cbor_coder;
1799
1800 my $data;
1801
1802 sub {
1803 my (@value) = eval { $cbor->incr_parse ($_[0]{rbuf}) };
1804
1805 if (@value) {
1806 $cb->($_[0], @value);
1807
1808 1
1809 } elsif ($@) {
1810 # error case
1811 $cbor->incr_reset;
1812
1813 $_[0]->_error (Errno::EBADMSG);
1814
1815 ()
1816 } else {
1817 ()
1818 }
1819 }
1820};
1821
1822=item storable => $cb->($handle, $ref)
1823
1824Deserialises a L<Storable> frozen representation as written by the
1825C<storable> write type (BER-encoded length prefix followed by nfreeze'd
1826data).
1827
1828Raises C<EBADMSG> error if the data could not be decoded.
1829
1830=cut
1831
1832register_read_type storable => sub {
1833 my ($self, $cb) = @_;
1834
1835 require Storable unless $Storable::VERSION;
1836
1837 sub {
1838 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1839 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1840 or return;
1841
1842 my $format = length pack "w", $len;
1843
1844 # bypass unshift if we already have the remaining chunk
1845 if ($format + $len <= length $_[0]{rbuf}) {
1846 my $data = substr $_[0]{rbuf}, $format, $len;
1847 substr $_[0]{rbuf}, 0, $format + $len, "";
1848
1849 eval { $cb->($_[0], Storable::thaw ($data)); 1 }
1850 or return $_[0]->_error (Errno::EBADMSG);
1851 } else {
1852 # remove prefix
1853 substr $_[0]{rbuf}, 0, $format, "";
1854
1855 # read remaining chunk
1856 $_[0]->unshift_read (chunk => $len, sub {
1857 eval { $cb->($_[0], Storable::thaw ($_[1])); 1 }
1858 or $_[0]->_error (Errno::EBADMSG);
1859 });
1860 }
1861
1862 1
1863 }
1864};
1865
1866=item tls_detect => $cb->($handle, $detect, $major, $minor)
1867
1868Checks the input stream for a valid SSL or TLS handshake TLSPaintext
1869record without consuming anything. Only SSL version 3 or higher
1870is handled, up to the fictituous protocol 4.x (but both SSL3+ and
1871SSL2-compatible framing is supported).
1872
1873If it detects that the input data is likely TLS, it calls the callback
1874with a true value for C<$detect> and the (on-wire) TLS version as second
1875and third argument (C<$major> is C<3>, and C<$minor> is 0..3 for SSL
18763.0, TLS 1.0, 1.1 and 1.2, respectively). If it detects the input to
1877be definitely not TLS, it calls the callback with a false value for
1878C<$detect>.
1879
1880The callback could use this information to decide whether or not to start
1881TLS negotiation.
1882
1883In all cases the data read so far is passed to the following read
1884handlers.
1885
1886Usually you want to use the C<tls_autostart> read type instead.
1887
1888If you want to design a protocol that works in the presence of TLS
1889dtection, make sure that any non-TLS data doesn't start with the octet 22
1890(ASCII SYN, 16 hex) or 128-255 (i.e. highest bit set). The checks this
1891read type does are a bit more strict, but might losen in the future to
1892accomodate protocol changes.
1893
1894This read type does not rely on L<AnyEvent::TLS> (and thus, not on
1895L<Net::SSLeay>).
1896
1897=item tls_autostart => $tls[, $tls_ctx]
1898
1899Tries to detect a valid SSL or TLS handshake. If one is detected, it tries
1900to start tls by calling C<starttls> with the given arguments.
1901
1902In practise, C<$tls> must be C<accept>, or a Net::SSLeay context that has
1903been configured to accept, as servers do not normally send a handshake on
1904their own and ths cannot be detected in this way.
1905
1906See C<tls_detect> above for more details.
1907
1908Example: give the client a chance to start TLS before accepting a text
1909line.
1910
1911 $hdl->push_read (tls_detect => "accept");
1912 $hdl->push_read (line => sub {
1913 print "received ", ($_[0]{tls} ? "encrypted" : "cleartext"), " <$_[1]>\n";
1914 });
1915
1916=cut
1917
1918register_read_type tls_detect => sub {
1919 my ($self, $cb) = @_;
1920
1921 sub {
1922 # this regex matches a full or partial tls record
1923 if (
1924 # ssl3+: type(22=handshake) major(=3) minor(any) length_hi
1925 $self->{rbuf} =~ /^(?:\z| \x16 (\z| [\x03\x04] (?:\z| . (?:\z| [\x00-\x40] ))))/xs
1926 # ssl2 comapatible: len_hi len_lo type(1) major minor dummy(forlength)
1927 or $self->{rbuf} =~ /^(?:\z| [\x80-\xff] (?:\z| . (?:\z| \x01 (\z| [\x03\x04] (?:\z| . (?:\z| . ))))))/xs
1928 ) {
1929 return if 3 != length $1; # partial match, can't decide yet
1930
1931 # full match, valid TLS record
1932 my ($major, $minor) = unpack "CC", $1;
1933 $cb->($self, "accept", $major + $minor * 0.1);
1934 } else {
1935 # mismatch == guaranteed not TLS
1936 $cb->($self, undef);
1937 }
1938
1939 1
1940 }
1941};
1942
1943register_read_type tls_autostart => sub {
1944 my ($self, @tls) = @_;
1945
1946 $RH{tls_detect}($self, sub {
1947 return unless $_[1];
1948 $_[0]->starttls (@tls);
1949 })
1950};
1951
915=back 1952=back
916 1953
917=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args) 1954=item custom read types - Package::anyevent_read_type $handle, $cb, @args
918 1955
919This function (not method) lets you add your own types to C<push_read>. 1956Instead of one of the predefined types, you can also specify the name
1957of a package. AnyEvent will try to load the package and then expects to
1958find a function named C<anyevent_read_type> inside. If it isn't found, it
1959progressively tries to load the parent package until it either finds the
1960function (good) or runs out of packages (bad).
920 1961
921Whenever the given C<type> is used, C<push_read> will invoke the code 1962Whenever this type is used, C<push_read> will invoke the function with the
922reference with the handle object, the callback and the remaining 1963handle object, the original callback and the remaining arguments.
923arguments.
924 1964
925The code reference is supposed to return a callback (usually a closure) 1965The function is supposed to return a callback (usually a closure) that
926that works as a plain read callback (see C<< ->push_read ($cb) >>). 1966works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
1967mentally treat the function as a "configurable read type to read callback"
1968converter.
927 1969
928It should invoke the passed callback when it is done reading (remember to 1970It should invoke the original callback when it is done reading (remember
929pass C<$handle> as first argument as all other callbacks do that). 1971to pass C<$handle> as first argument as all other callbacks do that,
1972although there is no strict requirement on this).
930 1973
931Note that this is a function, and all types registered this way will be
932global, so try to use unique names.
933
934For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>, 1974For examples, see the source of this module (F<perldoc -m
935search for C<register_read_type>)). 1975AnyEvent::Handle>, search for C<register_read_type>)).
936 1976
937=item $handle->stop_read 1977=item $handle->stop_read
938 1978
939=item $handle->start_read 1979=item $handle->start_read
940 1980
941In rare cases you actually do not want to read anything from the 1981In rare cases you actually do not want to read anything from the
942socket. In this case you can call C<stop_read>. Neither C<on_read> no 1982socket. In this case you can call C<stop_read>. Neither C<on_read> nor
943any queued callbacks will be executed then. To start reading again, call 1983any queued callbacks will be executed then. To start reading again, call
944C<start_read>. 1984C<start_read>.
945 1985
1986Note that AnyEvent::Handle will automatically C<start_read> for you when
1987you change the C<on_read> callback or push/unshift a read callback, and it
1988will automatically C<stop_read> for you when neither C<on_read> is set nor
1989there are any read requests in the queue.
1990
1991In older versions of this module (<= 5.3), these methods had no effect,
1992as TLS does not support half-duplex connections. In current versions they
1993work as expected, as this behaviour is required to avoid certain resource
1994attacks, where the program would be forced to read (and buffer) arbitrary
1995amounts of data before being able to send some data. The drawback is that
1996some readings of the the SSL/TLS specifications basically require this
1997attack to be working, as SSL/TLS implementations might stall sending data
1998during a rehandshake.
1999
2000As a guideline, during the initial handshake, you should not stop reading,
2001and as a client, it might cause problems, depending on your application.
2002
946=cut 2003=cut
947 2004
948sub stop_read { 2005sub stop_read {
949 my ($self) = @_; 2006 my ($self) = @_;
950 2007
952} 2009}
953 2010
954sub start_read { 2011sub start_read {
955 my ($self) = @_; 2012 my ($self) = @_;
956 2013
957 unless ($self->{_rw} || $self->{_eof}) { 2014 unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
958 Scalar::Util::weaken $self; 2015 Scalar::Util::weaken $self;
959 2016
960 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 2017 $self->{_rw} = AE::io $self->{fh}, 0, sub {
961 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 2018 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
962 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 2019 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
963 2020
964 if ($len > 0) { 2021 if ($len > 0) {
965 $self->{filter_r} 2022 $self->{_activity} = $self->{_ractivity} = AE::now;
966 ? $self->{filter_r}->($self, $rbuf) 2023
2024 if ($self->{tls}) {
2025 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
2026
2027 &_dotls ($self);
2028 } else {
967 : $self->_drain_rbuf; 2029 $self->_drain_rbuf;
2030 }
2031
2032 if ($len == $self->{read_size}) {
2033 $self->{read_size} *= 2;
2034 $self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
2035 if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
2036 }
968 2037
969 } elsif (defined $len) { 2038 } elsif (defined $len) {
970 delete $self->{_rw}; 2039 delete $self->{_rw};
971 $self->{_eof} = 1; 2040 $self->{_eof} = 1;
972 $self->_drain_rbuf; 2041 $self->_drain_rbuf;
973 2042
974 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { 2043 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
975 return $self->error; 2044 return $self->_error ($!, 1);
976 } 2045 }
977 }); 2046 };
978 } 2047 }
979} 2048}
980 2049
2050our $ERROR_SYSCALL;
2051our $ERROR_WANT_READ;
2052
2053sub _tls_error {
2054 my ($self, $err) = @_;
2055
2056 return $self->_error ($!, 1)
2057 if $err == Net::SSLeay::ERROR_SYSCALL ();
2058
2059 my $err = Net::SSLeay::ERR_error_string (Net::SSLeay::ERR_get_error ());
2060
2061 # reduce error string to look less scary
2062 $err =~ s/^error:[0-9a-fA-F]{8}:[^:]+:([^:]+):/\L$1: /;
2063
2064 if ($self->{_on_starttls}) {
2065 (delete $self->{_on_starttls})->($self, undef, $err);
2066 &_freetls;
2067 } else {
2068 &_freetls;
2069 $self->_error (Errno::EPROTO, 1, $err);
2070 }
2071}
2072
2073# poll the write BIO and send the data if applicable
2074# also decode read data if possible
2075# this is basiclaly our TLS state machine
2076# more efficient implementations are possible with openssl,
2077# but not with the buggy and incomplete Net::SSLeay.
981sub _dotls { 2078sub _dotls {
982 my ($self) = @_; 2079 my ($self) = @_;
983 2080
2081 my $tmp;
2082
984 if (length $self->{_tls_wbuf}) { 2083 while (length $self->{_tls_wbuf}) {
985 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) { 2084 if (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) <= 0) {
986 substr $self->{_tls_wbuf}, 0, $len, ""; 2085 $tmp = Net::SSLeay::get_error ($self->{tls}, $tmp);
2086
2087 return $self->_tls_error ($tmp)
2088 if $tmp != $ERROR_WANT_READ
2089 && ($tmp != $ERROR_SYSCALL || $!);
2090
2091 last;
987 } 2092 }
988 }
989 2093
2094 substr $self->{_tls_wbuf}, 0, $tmp, "";
2095 }
2096
2097 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
2098 unless (length $tmp) {
2099 $self->{_on_starttls}
2100 and (delete $self->{_on_starttls})->($self, undef, "EOF during handshake"); # ???
2101 &_freetls;
2102
2103 if ($self->{on_stoptls}) {
2104 $self->{on_stoptls}($self);
2105 return;
2106 } else {
2107 # let's treat SSL-eof as we treat normal EOF
2108 delete $self->{_rw};
2109 $self->{_eof} = 1;
2110 }
2111 }
2112
2113 $self->{_tls_rbuf} .= $tmp;
2114 $self->_drain_rbuf;
2115 $self->{tls} or return; # tls session might have gone away in callback
2116 }
2117
2118 $tmp = Net::SSLeay::get_error ($self->{tls}, -1); # -1 is not neccessarily correct, but Net::SSLeay doesn't tell us
2119 return $self->_tls_error ($tmp)
2120 if $tmp != $ERROR_WANT_READ
2121 && ($tmp != $ERROR_SYSCALL || $!);
2122
990 if (defined (my $buf = Net::SSLeay::BIO_read ($self->{_wbio}))) { 2123 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
991 $self->{wbuf} .= $buf; 2124 $self->{wbuf} .= $tmp;
992 $self->_drain_wbuf; 2125 $self->_drain_wbuf;
2126 $self->{tls} or return; # tls session might have gone away in callback
993 } 2127 }
994 2128
995 while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) { 2129 $self->{_on_starttls}
996 $self->{rbuf} .= $buf; 2130 and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
997 $self->_drain_rbuf; 2131 and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
998 }
999
1000 my $err = Net::SSLeay::get_error ($self->{tls}, -1);
1001
1002 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
1003 if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
1004 $self->error;
1005 } elsif ($err == Net::SSLeay::ERROR_SSL ()) {
1006 $! = &Errno::EIO;
1007 $self->error;
1008 }
1009
1010 # all others are fine for our purposes
1011 }
1012} 2132}
1013 2133
1014=item $handle->starttls ($tls[, $tls_ctx]) 2134=item $handle->starttls ($tls[, $tls_ctx])
1015 2135
1016Instead of starting TLS negotiation immediately when the AnyEvent::Handle 2136Instead of starting TLS negotiation immediately when the AnyEvent::Handle
1017object is created, you can also do that at a later time by calling 2137object is created, you can also do that at a later time by calling
1018C<starttls>. 2138C<starttls>. See the C<tls> constructor argument for general info.
2139
2140Starting TLS is currently an asynchronous operation - when you push some
2141write data and then call C<< ->starttls >> then TLS negotiation will start
2142immediately, after which the queued write data is then sent. This might
2143change in future versions, so best make sure you have no outstanding write
2144data when calling this method.
1019 2145
1020The first argument is the same as the C<tls> constructor argument (either 2146The first argument is the same as the C<tls> constructor argument (either
1021C<"connect">, C<"accept"> or an existing Net::SSLeay object). 2147C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1022 2148
1023The second argument is the optional C<Net::SSLeay::CTX> object that is 2149The second argument is the optional C<AnyEvent::TLS> object that is used
1024used when AnyEvent::Handle has to create its own TLS connection object. 2150when AnyEvent::Handle has to create its own TLS connection object, or
2151a hash reference with C<< key => value >> pairs that will be used to
2152construct a new context.
1025 2153
1026The TLS connection object will end up in C<< $handle->{tls} >> after this 2154The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1027call and can be used or changed to your liking. Note that the handshake 2155context in C<< $handle->{tls_ctx} >> after this call and can be used or
1028might have already started when this function returns. 2156changed to your liking. Note that the handshake might have already started
2157when this function returns.
1029 2158
1030=cut 2159Due to bugs in OpenSSL, it might or might not be possible to do multiple
2160handshakes on the same stream. It is best to not attempt to use the
2161stream after stopping TLS.
1031 2162
1032# TODO: maybe document... 2163This method may invoke callbacks (and therefore the handle might be
2164destroyed after it returns).
2165
2166=cut
2167
2168our %TLS_CACHE; #TODO not yet documented, should we?
2169
1033sub starttls { 2170sub starttls {
1034 my ($self, $ssl, $ctx) = @_; 2171 my ($self, $tls, $ctx) = @_;
1035 2172
1036 $self->stoptls; 2173 Carp::croak "It is an error to call starttls on an AnyEvent::Handle object while TLS is already active, caught"
2174 if $self->{tls};
1037 2175
1038 if ($ssl eq "accept") { 2176 unless (defined $AnyEvent::TLS::VERSION) {
1039 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 2177 eval {
1040 Net::SSLeay::set_accept_state ($ssl); 2178 require Net::SSLeay;
1041 } elsif ($ssl eq "connect") { 2179 require AnyEvent::TLS;
1042 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 2180 1
1043 Net::SSLeay::set_connect_state ($ssl); 2181 } or return $self->_error (Errno::EPROTO, 1, "TLS support not available on this system");
2182 }
2183
2184 $self->{tls} = $tls;
2185 $self->{tls_ctx} = $ctx if @_ > 2;
2186
2187 return unless $self->{fh};
2188
2189 $ERROR_SYSCALL = Net::SSLeay::ERROR_SYSCALL ();
2190 $ERROR_WANT_READ = Net::SSLeay::ERROR_WANT_READ ();
2191
2192 $tls = delete $self->{tls};
2193 $ctx = $self->{tls_ctx};
2194
2195 local $Carp::CarpLevel = 1; # skip ourselves when creating a new context or session
2196
2197 if ("HASH" eq ref $ctx) {
2198 if ($ctx->{cache}) {
2199 my $key = $ctx+0;
2200 $ctx = $TLS_CACHE{$key} ||= new AnyEvent::TLS %$ctx;
2201 } else {
2202 $ctx = new AnyEvent::TLS %$ctx;
2203 }
2204 }
1044 } 2205
1045 2206 $self->{tls_ctx} = $ctx || TLS_CTX ();
1046 $self->{tls} = $ssl; 2207 $self->{tls} = $tls = $self->{tls_ctx}->_get_session ($tls, $self, $self->{peername});
1047 2208
1048 # basically, this is deep magic (because SSL_read should have the same issues) 2209 # basically, this is deep magic (because SSL_read should have the same issues)
1049 # but the openssl maintainers basically said: "trust us, it just works". 2210 # but the openssl maintainers basically said: "trust us, it just works".
1050 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 2211 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
1051 # and mismaintained ssleay-module doesn't even offer them). 2212 # and mismaintained ssleay-module doesn't even offer them).
1052 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 2213 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
2214 #
2215 # in short: this is a mess.
2216 #
2217 # note that we do not try to keep the length constant between writes as we are required to do.
2218 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
2219 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
2220 # have identity issues in that area.
1053 Net::SSLeay::CTX_set_mode ($self->{tls}, 2221# Net::SSLeay::CTX_set_mode ($ssl,
1054 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 2222# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1055 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 2223# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
2224 Net::SSLeay::CTX_set_mode ($tls, 1|2);
1056 2225
1057 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 2226 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1058 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 2227 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1059 2228
2229 Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
2230 $self->{rbuf} = "";
2231
1060 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio}); 2232 Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
1061 2233
1062 $self->{filter_w} = sub { 2234 $self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
1063 $_[0]{_tls_wbuf} .= ${$_[1]}; 2235 if $self->{on_starttls};
1064 &_dotls; 2236
1065 }; 2237 &_dotls; # need to trigger the initial handshake
1066 $self->{filter_r} = sub { 2238 $self->start_read; # make sure we actually do read
1067 Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
1068 &_dotls;
1069 };
1070} 2239}
1071 2240
1072=item $handle->stoptls 2241=item $handle->stoptls
1073 2242
1074Destroys the SSL connection, if any. Partial read or write data will be 2243Shuts down the SSL connection - this makes a proper EOF handshake by
1075lost. 2244sending a close notify to the other side, but since OpenSSL doesn't
2245support non-blocking shut downs, it is not guaranteed that you can re-use
2246the stream afterwards.
2247
2248This method may invoke callbacks (and therefore the handle might be
2249destroyed after it returns).
1076 2250
1077=cut 2251=cut
1078 2252
1079sub stoptls { 2253sub stoptls {
1080 my ($self) = @_; 2254 my ($self) = @_;
1081 2255
1082 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 2256 if ($self->{tls} && $self->{fh}) {
2257 Net::SSLeay::shutdown ($self->{tls});
1083 2258
1084 delete $self->{_rbio}; 2259 &_dotls;
1085 delete $self->{_wbio}; 2260
1086 delete $self->{_tls_wbuf}; 2261# # we don't give a shit. no, we do, but we can't. no...#d#
1087 delete $self->{filter_r}; 2262# # we, we... have to use openssl :/#d#
1088 delete $self->{filter_w}; 2263# &_freetls;#d#
2264 }
1089} 2265}
2266
2267sub _freetls {
2268 my ($self) = @_;
2269
2270 return unless $self->{tls};
2271
2272 $self->{tls_ctx}->_put_session (delete $self->{tls})
2273 if $self->{tls} > 0;
2274
2275 delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
2276}
2277
2278=item $handle->resettls
2279
2280This rarely-used method simply resets and TLS state on the handle, usually
2281causing data loss.
2282
2283One case where it may be useful is when you want to skip over the data in
2284the stream but you are not interested in interpreting it, so data loss is
2285no concern.
2286
2287=cut
2288
2289*resettls = \&_freetls;
1090 2290
1091sub DESTROY { 2291sub DESTROY {
1092 my $self = shift; 2292 my ($self) = @_;
1093 2293
1094 $self->stoptls; 2294 &_freetls;
2295
2296 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
2297
2298 if ($linger && length $self->{wbuf} && $self->{fh}) {
2299 my $fh = delete $self->{fh};
2300 my $wbuf = delete $self->{wbuf};
2301
2302 my @linger;
2303
2304 push @linger, AE::io $fh, 1, sub {
2305 my $len = syswrite $fh, $wbuf, length $wbuf;
2306
2307 if ($len > 0) {
2308 substr $wbuf, 0, $len, "";
2309 } elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
2310 @linger = (); # end
2311 }
2312 };
2313 push @linger, AE::timer $linger, 0, sub {
2314 @linger = ();
2315 };
2316 }
1095} 2317}
2318
2319=item $handle->destroy
2320
2321Shuts down the handle object as much as possible - this call ensures that
2322no further callbacks will be invoked and as many resources as possible
2323will be freed. Any method you will call on the handle object after
2324destroying it in this way will be silently ignored (and it will return the
2325empty list).
2326
2327Normally, you can just "forget" any references to an AnyEvent::Handle
2328object and it will simply shut down. This works in fatal error and EOF
2329callbacks, as well as code outside. It does I<NOT> work in a read or write
2330callback, so when you want to destroy the AnyEvent::Handle object from
2331within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
2332that case.
2333
2334Destroying the handle object in this way has the advantage that callbacks
2335will be removed as well, so if those are the only reference holders (as
2336is common), then one doesn't need to do anything special to break any
2337reference cycles.
2338
2339The handle might still linger in the background and write out remaining
2340data, as specified by the C<linger> option, however.
2341
2342=cut
2343
2344sub destroy {
2345 my ($self) = @_;
2346
2347 $self->DESTROY;
2348 %$self = ();
2349 bless $self, "AnyEvent::Handle::destroyed";
2350}
2351
2352sub AnyEvent::Handle::destroyed::AUTOLOAD {
2353 #nop
2354}
2355
2356=item $handle->destroyed
2357
2358Returns false as long as the handle hasn't been destroyed by a call to C<<
2359->destroy >>, true otherwise.
2360
2361Can be useful to decide whether the handle is still valid after some
2362callback possibly destroyed the handle. For example, C<< ->push_write >>,
2363C<< ->starttls >> and other methods can call user callbacks, which in turn
2364can destroy the handle, so work can be avoided by checking sometimes:
2365
2366 $hdl->starttls ("accept");
2367 return if $hdl->destroyed;
2368 $hdl->push_write (...
2369
2370Note that the call to C<push_write> will silently be ignored if the handle
2371has been destroyed, so often you can just ignore the possibility of the
2372handle being destroyed.
2373
2374=cut
2375
2376sub destroyed { 0 }
2377sub AnyEvent::Handle::destroyed::destroyed { 1 }
1096 2378
1097=item AnyEvent::Handle::TLS_CTX 2379=item AnyEvent::Handle::TLS_CTX
1098 2380
1099This function creates and returns the Net::SSLeay::CTX object used by 2381This function creates and returns the AnyEvent::TLS object used by default
1100default for TLS mode. 2382for TLS mode.
1101 2383
1102The context is created like this: 2384The context is created by calling L<AnyEvent::TLS> without any arguments.
1103
1104 Net::SSLeay::load_error_strings;
1105 Net::SSLeay::SSLeay_add_ssl_algorithms;
1106 Net::SSLeay::randomize;
1107
1108 my $CTX = Net::SSLeay::CTX_new;
1109
1110 Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
1111 2385
1112=cut 2386=cut
1113 2387
1114our $TLS_CTX; 2388our $TLS_CTX;
1115 2389
1116sub TLS_CTX() { 2390sub TLS_CTX() {
1117 $TLS_CTX || do { 2391 $TLS_CTX ||= do {
1118 require Net::SSLeay; 2392 require AnyEvent::TLS;
1119 2393
1120 Net::SSLeay::load_error_strings (); 2394 new AnyEvent::TLS
1121 Net::SSLeay::SSLeay_add_ssl_algorithms (); 2395 }
1122 Net::SSLeay::randomize (); 2396}
1123 2397
1124 $TLS_CTX = Net::SSLeay::CTX_new (); 2398=back
1125 2399
1126 Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
1127 2400
1128 $TLS_CTX 2401=head1 NONFREQUENTLY ASKED QUESTIONS
2402
2403=over 4
2404
2405=item I C<undef> the AnyEvent::Handle reference inside my callback and
2406still get further invocations!
2407
2408That's because AnyEvent::Handle keeps a reference to itself when handling
2409read or write callbacks.
2410
2411It is only safe to "forget" the reference inside EOF or error callbacks,
2412from within all other callbacks, you need to explicitly call the C<<
2413->destroy >> method.
2414
2415=item Why is my C<on_eof> callback never called?
2416
2417Probably because your C<on_error> callback is being called instead: When
2418you have outstanding requests in your read queue, then an EOF is
2419considered an error as you clearly expected some data.
2420
2421To avoid this, make sure you have an empty read queue whenever your handle
2422is supposed to be "idle" (i.e. connection closes are O.K.). You can set
2423an C<on_read> handler that simply pushes the first read requests in the
2424queue.
2425
2426See also the next question, which explains this in a bit more detail.
2427
2428=item How can I serve requests in a loop?
2429
2430Most protocols consist of some setup phase (authentication for example)
2431followed by a request handling phase, where the server waits for requests
2432and handles them, in a loop.
2433
2434There are two important variants: The first (traditional, better) variant
2435handles requests until the server gets some QUIT command, causing it to
2436close the connection first (highly desirable for a busy TCP server). A
2437client dropping the connection is an error, which means this variant can
2438detect an unexpected detection close.
2439
2440To handle this case, always make sure you have a non-empty read queue, by
2441pushing the "read request start" handler on it:
2442
2443 # we assume a request starts with a single line
2444 my @start_request; @start_request = (line => sub {
2445 my ($hdl, $line) = @_;
2446
2447 ... handle request
2448
2449 # push next request read, possibly from a nested callback
2450 $hdl->push_read (@start_request);
2451 });
2452
2453 # auth done, now go into request handling loop
2454 # now push the first @start_request
2455 $hdl->push_read (@start_request);
2456
2457By always having an outstanding C<push_read>, the handle always expects
2458some data and raises the C<EPIPE> error when the connction is dropped
2459unexpectedly.
2460
2461The second variant is a protocol where the client can drop the connection
2462at any time. For TCP, this means that the server machine may run out of
2463sockets easier, and in general, it means you cannot distinguish a protocl
2464failure/client crash from a normal connection close. Nevertheless, these
2465kinds of protocols are common (and sometimes even the best solution to the
2466problem).
2467
2468Having an outstanding read request at all times is possible if you ignore
2469C<EPIPE> errors, but this doesn't help with when the client drops the
2470connection during a request, which would still be an error.
2471
2472A better solution is to push the initial request read in an C<on_read>
2473callback. This avoids an error, as when the server doesn't expect data
2474(i.e. is idly waiting for the next request, an EOF will not raise an
2475error, but simply result in an C<on_eof> callback. It is also a bit slower
2476and simpler:
2477
2478 # auth done, now go into request handling loop
2479 $hdl->on_read (sub {
2480 my ($hdl) = @_;
2481
2482 # called each time we receive data but the read queue is empty
2483 # simply start read the request
2484
2485 $hdl->push_read (line => sub {
2486 my ($hdl, $line) = @_;
2487
2488 ... handle request
2489
2490 # do nothing special when the request has been handled, just
2491 # let the request queue go empty.
2492 });
2493 });
2494
2495=item I get different callback invocations in TLS mode/Why can't I pause
2496reading?
2497
2498Unlike, say, TCP, TLS connections do not consist of two independent
2499communication channels, one for each direction. Or put differently, the
2500read and write directions are not independent of each other: you cannot
2501write data unless you are also prepared to read, and vice versa.
2502
2503This means that, in TLS mode, you might get C<on_error> or C<on_eof>
2504callback invocations when you are not expecting any read data - the reason
2505is that AnyEvent::Handle always reads in TLS mode.
2506
2507During the connection, you have to make sure that you always have a
2508non-empty read-queue, or an C<on_read> watcher. At the end of the
2509connection (or when you no longer want to use it) you can call the
2510C<destroy> method.
2511
2512=item How do I read data until the other side closes the connection?
2513
2514If you just want to read your data into a perl scalar, the easiest way
2515to achieve this is by setting an C<on_read> callback that does nothing,
2516clearing the C<on_eof> callback and in the C<on_error> callback, the data
2517will be in C<$_[0]{rbuf}>:
2518
2519 $handle->on_read (sub { });
2520 $handle->on_eof (undef);
2521 $handle->on_error (sub {
2522 my $data = delete $_[0]{rbuf};
2523 });
2524
2525Note that this example removes the C<rbuf> member from the handle object,
2526which is not normally allowed by the API. It is expressly permitted in
2527this case only, as the handle object needs to be destroyed afterwards.
2528
2529The reason to use C<on_error> is that TCP connections, due to latencies
2530and packets loss, might get closed quite violently with an error, when in
2531fact all data has been received.
2532
2533It is usually better to use acknowledgements when transferring data,
2534to make sure the other side hasn't just died and you got the data
2535intact. This is also one reason why so many internet protocols have an
2536explicit QUIT command.
2537
2538=item I don't want to destroy the handle too early - how do I wait until
2539all data has been written?
2540
2541After writing your last bits of data, set the C<on_drain> callback
2542and destroy the handle in there - with the default setting of
2543C<low_water_mark> this will be called precisely when all data has been
2544written to the socket:
2545
2546 $handle->push_write (...);
2547 $handle->on_drain (sub {
2548 AE::log debug => "All data submitted to the kernel.";
2549 undef $handle;
2550 });
2551
2552If you just want to queue some data and then signal EOF to the other side,
2553consider using C<< ->push_shutdown >> instead.
2554
2555=item I want to contact a TLS/SSL server, I don't care about security.
2556
2557If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
2558connect to it and then create the AnyEvent::Handle with the C<tls>
2559parameter:
2560
2561 tcp_connect $host, $port, sub {
2562 my ($fh) = @_;
2563
2564 my $handle = new AnyEvent::Handle
2565 fh => $fh,
2566 tls => "connect",
2567 on_error => sub { ... };
2568
2569 $handle->push_write (...);
1129 } 2570 };
1130} 2571
2572=item I want to contact a TLS/SSL server, I do care about security.
2573
2574Then you should additionally enable certificate verification, including
2575peername verification, if the protocol you use supports it (see
2576L<AnyEvent::TLS>, C<verify_peername>).
2577
2578E.g. for HTTPS:
2579
2580 tcp_connect $host, $port, sub {
2581 my ($fh) = @_;
2582
2583 my $handle = new AnyEvent::Handle
2584 fh => $fh,
2585 peername => $host,
2586 tls => "connect",
2587 tls_ctx => { verify => 1, verify_peername => "https" },
2588 ...
2589
2590Note that you must specify the hostname you connected to (or whatever
2591"peername" the protocol needs) as the C<peername> argument, otherwise no
2592peername verification will be done.
2593
2594The above will use the system-dependent default set of trusted CA
2595certificates. If you want to check against a specific CA, add the
2596C<ca_file> (or C<ca_cert>) arguments to C<tls_ctx>:
2597
2598 tls_ctx => {
2599 verify => 1,
2600 verify_peername => "https",
2601 ca_file => "my-ca-cert.pem",
2602 },
2603
2604=item I want to create a TLS/SSL server, how do I do that?
2605
2606Well, you first need to get a server certificate and key. You have
2607three options: a) ask a CA (buy one, use cacert.org etc.) b) create a
2608self-signed certificate (cheap. check the search engine of your choice,
2609there are many tutorials on the net) or c) make your own CA (tinyca2 is a
2610nice program for that purpose).
2611
2612Then create a file with your private key (in PEM format, see
2613L<AnyEvent::TLS>), followed by the certificate (also in PEM format). The
2614file should then look like this:
2615
2616 -----BEGIN RSA PRIVATE KEY-----
2617 ...header data
2618 ... lots of base64'y-stuff
2619 -----END RSA PRIVATE KEY-----
2620
2621 -----BEGIN CERTIFICATE-----
2622 ... lots of base64'y-stuff
2623 -----END CERTIFICATE-----
2624
2625The important bits are the "PRIVATE KEY" and "CERTIFICATE" parts. Then
2626specify this file as C<cert_file>:
2627
2628 tcp_server undef, $port, sub {
2629 my ($fh) = @_;
2630
2631 my $handle = new AnyEvent::Handle
2632 fh => $fh,
2633 tls => "accept",
2634 tls_ctx => { cert_file => "my-server-keycert.pem" },
2635 ...
2636
2637When you have intermediate CA certificates that your clients might not
2638know about, just append them to the C<cert_file>.
1131 2639
1132=back 2640=back
1133 2641
1134=head1 SUBCLASSING AnyEvent::Handle 2642=head1 SUBCLASSING AnyEvent::Handle
1135 2643
1141=over 4 2649=over 4
1142 2650
1143=item * all constructor arguments become object members. 2651=item * all constructor arguments become object members.
1144 2652
1145At least initially, when you pass a C<tls>-argument to the constructor it 2653At least initially, when you pass a C<tls>-argument to the constructor it
1146will end up in C<< $handle->{tls} >>. Those members might be changes or 2654will end up in C<< $handle->{tls} >>. Those members might be changed or
1147mutated later on (for example C<tls> will hold the TLS connection object). 2655mutated later on (for example C<tls> will hold the TLS connection object).
1148 2656
1149=item * other object member names are prefixed with an C<_>. 2657=item * other object member names are prefixed with an C<_>.
1150 2658
1151All object members not explicitly documented (internal use) are prefixed 2659All object members not explicitly documented (internal use) are prefixed
1154 2662
1155=item * all members not documented here and not prefixed with an underscore 2663=item * all members not documented here and not prefixed with an underscore
1156are free to use in subclasses. 2664are free to use in subclasses.
1157 2665
1158Of course, new versions of AnyEvent::Handle may introduce more "public" 2666Of course, new versions of AnyEvent::Handle may introduce more "public"
1159member variables, but thats just life, at least it is documented. 2667member variables, but that's just life. At least it is documented.
1160 2668
1161=back 2669=back
1162 2670
1163=head1 AUTHOR 2671=head1 AUTHOR
1164 2672
1165Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>. 2673Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
1166 2674
1167=cut 2675=cut
1168 2676
11691; # End of AnyEvent::Handle 26771
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