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Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.208 by root, Sun Dec 5 11:41:45 2010 UTC vs.
Revision 1.209 by root, Wed Dec 29 04:40:23 2010 UTC

… …
278For example, a server accepting connections from untrusted sources should 278For example, a server accepting connections from untrusted sources should
279be configured to accept only so-and-so much data that it cannot act on 279be configured to accept only so-and-so much data that it cannot act on
280(for example, when expecting a line, an attacker could send an unlimited 280(for example, when expecting a line, an attacker could send an unlimited
281amount of data without a callback ever being called as long as the line 281amount of data without a callback ever being called as long as the line
282isn't finished). 282isn't finished).
283
284=item wbuf_max => <bytes>
285
286If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
287when the write buffer ever (strictly) exceeds this size. This is useful to
288avoid some forms of denial-of-service attacks.
289
290Although the units of this parameter is bytes, this is the I<raw> number
291of bytes not yet accepted by the kernel. This can make a difference when
292you e.g. use TLS, as TLS typically makes your write data larger (but it
293can also make it smaller due to compression).
294
295As an example of when this limit is useful, take a chat server that sends
296chat messages to a client. If the client does not read those in a timely
297manner then the send buffer in the server would grow unbounded.
283 298
284=item autocork => <boolean> 299=item autocork => <boolean>
285 300
286When disabled (the default), C<push_write> will try to immediately 301When disabled (the default), C<push_write> will try to immediately
287write the data to the handle if possible. This avoids having to register 302write the data to the handle if possible. This avoids having to register
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740 755
741=item $handle->rbuf_max ($max_octets) 756=item $handle->rbuf_max ($max_octets)
742 757
743Configures the C<rbuf_max> setting (C<undef> disables it). 758Configures the C<rbuf_max> setting (C<undef> disables it).
744 759
760=item $handle->wbuf_max ($max_octets)
761
762Configures the C<wbuf_max> setting (C<undef> disables it).
763
745=cut 764=cut
746 765
747sub rbuf_max { 766sub rbuf_max {
748 $_[0]{rbuf_max} = $_[1]; 767 $_[0]{rbuf_max} = $_[1];
768}
769
770sub rbuf_max {
771 $_[0]{wbuf_max} = $_[1];
749} 772}
750 773
751############################################################################# 774#############################################################################
752 775
753=item $handle->timeout ($seconds) 776=item $handle->timeout ($seconds)
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873 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf}); 896 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
874} 897}
875 898
876=item $handle->push_write ($data) 899=item $handle->push_write ($data)
877 900
878Queues the given scalar to be written. You can push as much data as you 901Queues the given scalar to be written. You can push as much data as
879want (only limited by the available memory), as C<AnyEvent::Handle> 902you want (only limited by the available memory and C<wbuf_max>), as
880buffers it independently of the kernel. 903C<AnyEvent::Handle> buffers it independently of the kernel.
881 904
882This method may invoke callbacks (and therefore the handle might be 905This method may invoke callbacks (and therefore the handle might be
883destroyed after it returns). 906destroyed after it returns).
884 907
885=cut 908=cut
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913 $cb->() unless $self->{autocork}; 936 $cb->() unless $self->{autocork};
914 937
915 # if still data left in wbuf, we need to poll 938 # if still data left in wbuf, we need to poll
916 $self->{_ww} = AE::io $self->{fh}, 1, $cb 939 $self->{_ww} = AE::io $self->{fh}, 1, $cb
917 if length $self->{wbuf}; 940 if length $self->{wbuf};
941
942 if (
943 defined $self->{wbuf_max}
944 && $self->{wbuf_max} < length $self->{wbuf}
945 ) {
946 $self->_error (Errno::ENOSPC, 1), return;
947 }
918 }; 948 };
919} 949}
920 950
921our %WH; 951our %WH;
922 952

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