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=head1 NAME |
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|
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AnyEvent::FastPing - quickly ping a large number of hosts |
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|
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=head1 SYNOPSIS |
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|
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use AnyEvent::FastPing; |
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|
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=head1 DESCRIPTION |
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|
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This module was written for a single purpose only: sending ICMP ECHO |
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REQUEST packets as quickly as possible to a large number of hosts |
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(thousands to millions). |
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|
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It employs a sending thread and is fully event-driven (using AnyEvent), so |
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you have to run an event model supported by AnyEvent to use this module. |
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|
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=head1 FUNCTIONS |
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|
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=over 4 |
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|
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=cut |
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|
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package AnyEvent::FastPing; |
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|
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use common::sense; |
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|
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use AnyEvent; |
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|
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BEGIN { |
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our $VERSION = '2.0'; |
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our @ISA = qw(Exporter); |
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|
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require Exporter; |
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#Exporter::export_ok_tags (keys %EXPORT_TAGS); |
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|
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require XSLoader; |
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XSLoader::load (__PACKAGE__, $VERSION); |
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} |
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|
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our ($THR_RES_FD, $ICMP4_FD, $ICMP6_FD); |
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|
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our $THR_RES_FH; open $THR_RES_FH, "<&=$THR_RES_FD" or die "FATAL: cannot fdopen"; |
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|
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our $ICMP4_FH; our $ICMP4_W = $ICMP4_FD >= 0 && (open $ICMP4_FH, "<&=$ICMP4_FD") && AE::io $ICMP4_FH, 0, \&_recv_icmp4; |
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our $ICMP6_FH; our $ICMP6_W = $ICMP6_FD >= 0 && (open $ICMP6_FH, "<&=$ICMP6_FD") && AE::io $ICMP6_FH, 0, \&_recv_icmp6; |
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|
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=item AnyEvent::FastPing::ipv4_supported |
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|
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Returns true iff IPv4 is supported in this module and on this system. |
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|
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=item AnyEvent::FastPing::ipv6_supported |
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|
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Returns true iff IPv6 is supported in this module and on this system. |
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|
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=item AnyEvent::FastPing::icmp4_pktsize |
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|
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Returns the number of octets per IPv4 ping packet (the whole IP packet |
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including headers, excluding lower-level headers or trailers such as |
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Ethernet). |
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|
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Can be used to calculate e.g. octets/s from rate ... |
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|
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my $octets_per_second = $packets_per_second * AnyEvent::FastPing::icmp4_pktsize; |
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|
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... or convert kilobit/second to packet rate ... |
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|
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my $packets_per_second = $kilobit_per_second |
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* (1000 / 8 / AnyEvent::FastPing::icmp4_pktsize); |
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|
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etc. |
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|
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=item AnyEvent::FastPing::icmp6_pktsize |
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|
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Like AnyEvent::FastPing::icmp4_pktsize, but for IPv6. |
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|
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=back |
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|
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=head1 THE AnyEvent::FastPing CLASS |
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|
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The AnyEvent::FastPing class represents a single "pinger". A "pinger" |
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comes with its own thread to send packets in the background, a rate-limit |
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machinery and separate idle/receive callbacks. |
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|
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The recommended workflow (there are others) is this: 1. create a new |
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AnyEvent::FastPing object 2. configure the address lists and ranges to |
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ping, also configure an idle callback and optionally a receive callback |
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3. C<start> the pinger. |
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|
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When the pinger has finished pinging all the configured addresses it will |
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call the idle callback. |
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|
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The pinging process works like this: every range has a minimum interval |
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between sends, which is used to limit the rate at which hosts in that |
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range are being pinged. Distinct ranges are independent of each other, |
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which is why there is a per-pinger "global" minimum interval as well. |
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|
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The pinger sends pings as fats as possible, while both obeying the pinger |
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rate limit as well as range limits. |
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|
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When a range is exhausted, it is removed. When all ranges are exhausted, |
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the pinger waits another C<max_rtt> seconds and then exits, causing the |
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idle callback to trigger. |
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|
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Performance: On my 2 GHz Opteron system with a pretty average nvidia |
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gigabit network card I can ping around 60k to 200k adresses per second, |
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depending on routing decisions. |
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|
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Example: ping 10.0.0.1-10.0.0.15 with at most 100 packets/s, and |
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11.0.0.1-11.0.255.255 with at most 1000 packets/s. Also ping the IPv6 |
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loopback address 5 times as fast as possible. Do not, however, exceed 1000 |
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packets/s overall. Dump each received reply: |
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|
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use AnyEvent::Socket; |
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use AnyEvent::FastPing; |
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|
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my $done = AnyEvent->condvar; |
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|
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my $pinger = new AnyEvent::FastPing; |
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|
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$pinger->interval (1/1000); |
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$pinger->max_rtt (0.1); # reasonably fast/reliable network |
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|
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$pinger->add_range (v10.0.0.1, v10.0.0.15, 1/100); |
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$pinger->add_range (v11.0.0.1, v11.0.255.255, 1/1000); |
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$pinger->add_hosts ([ (v0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.1) x 5 ]); |
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|
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$pinger->on_recv (sub { |
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for (@{ $_[0] }) { |
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printf "%s %g\n", (AnyEvent::Socket::format_address $_->[0]), $_->[1]; |
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} |
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}); |
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|
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$pinger->on_idle (sub { |
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print "done\n"; |
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undef $pinger; |
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}); |
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|
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$pinger->start; |
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$done->wait; |
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|
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=head2 METHODS |
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|
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=over 4 |
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|
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=item $pinger = new AnyEvent::FastPing |
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|
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Creates a new pinger - right now there can be at most C<65536> pingers in |
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a process, although that limit might change to somethind drastically lower |
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- you should be stringy with your pinger objects. |
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|
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=cut |
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|
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sub new { |
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my ($klass) = @_; |
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|
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_new $klass, (rand 65536), (rand 65536), (rand 65536) |
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} |
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|
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our @IDLE_CB; |
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|
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sub DESTROY { |
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undef $IDLE_CB[ &id ]; |
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&_free; |
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} |
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|
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=item $pinger->on_recv ($callback->([[$host, $rtt], ...])) |
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|
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Registeres a callback to be called for ping replies. If no callback has |
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been registered than ping replies will be ignored, otherwise this module |
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calculates the round trip time, in seconds, for each reply and calls this |
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callback. |
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|
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The callback receives a single argument, which is an array reference |
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with an entry for each reply packet (the replies will be batched for |
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efficiency). Each member in the array reference is again an array |
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reference with exactly two members: the binary host addresss (4 octets for |
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IPv4, 16 for IPv6) and the approximate round trip time, in seconds. |
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|
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The replies will be passed to the callback as soon as they arrive, and |
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this callback can be called many times with batches of replies. |
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|
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The receive callback will be called whenever a suitable reply arrives, |
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whether generated by this pinger or not, whether this pinger is started |
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or not. The packets will have a unique 64 bit ID to distinguish them from |
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other pinger objects and other generators, but this doesn't help against |
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malicious replies. |
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|
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Note that very high packet rates can overwhelm your process, causing |
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replies to be dropped (configure your kernel with long receive queues for |
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raw sockets if this is a problem). |
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|
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Example: register a callback which simply dumps the received data. |
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|
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use AnyEvent::Socket; |
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|
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$pinger->on_recv (sub { |
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for (@{ $_[0] }) { |
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printf "%s %g\n", (AnyEvent::Socket::format_address $_->[0]), $_->[1]; |
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} |
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}; |
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|
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Example: a single ping reply with payload of 1 from C<::1> gets passed |
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like this: |
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|
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[ |
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[ "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\1", 0.000280141830444336 ] |
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] |
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|
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Example: ping replies for C<127.0.0.1> and C<127.0.0.2>: |
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|
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[ |
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[ "\177\0\0\1", 0.00015711784362793 ], |
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[ "\177\0\0\2", 0.00090184211731 ] |
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] |
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|
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=item $pinger->on_idle ($callback->()) |
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|
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Registers a callback to be called when the pinger becomes I<idle>, that |
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is, it has been started, has exhausted all ping ranges and waited for |
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the C<max_rtt> time. An idle pinger is also stopped, so the callback can |
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instantly add new ranges, if it so desires. |
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|
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=cut |
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|
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sub on_idle { |
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$IDLE_CB[ &id ] = $_[1]; |
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} |
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|
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our $THR_RES_W = AE::io $THR_RES_FH, 0, sub { |
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sysread $THR_RES_FH, my $buf, 8; |
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|
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for my $id (unpack "S*", $buf) { |
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_stop_id $id; |
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($IDLE_CB[$id] || sub { })->(); |
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} |
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}; |
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|
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=item $pinger->interval ($seconds) |
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|
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Configures the minimum interval between packet sends for this pinger - the |
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pinger will not send packets faster than this rate (or atcually 1 / rate), |
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even if individual ranges have a lower interval. |
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|
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A value of C<0> selects the fastests possible speed (currently no faster |
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than 1_000_000 packets/s). |
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|
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=item $pinger->max_rtt ($seconds) |
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|
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If your idle callback were called instantly after all ranges were |
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exhausted and you destroyed the object inside (which is common), then |
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there would be no chance to receive some replies, as there would be no |
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time fo the packet to travel over the network. |
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|
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This can be fixed by starting a timer in the idle callback, or more simply |
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by selecting a suitable C<max_rtt> value, which should be the maximum time |
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you allow a ping packet to travel to its destinazion and back. |
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|
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The pinger thread automatically waits for this amount of time before becoming idle. |
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|
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The default is currently C<0.5> seconds, which is usually plenty. |
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|
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=item $pinger->add_range ($lo, $hi[, $interval]) |
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|
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Ping the IPv4 (or IPv6, but see below) address range, starting at binary |
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address C<$lo> and ending at C<$hi> (both C<$lo> and C<$hi> will be |
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pinged), generating no more than one ping per C<$interval> seconds (or as |
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fast as possible if omitted). |
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|
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You can convert IP addresses from text to binary form by |
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using C<AnyEvent::Util::parse_address>, C<Socket::inet_aton>, |
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C<Socket6::inet_pton> or any other method that you like :) |
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|
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The algorithm to select the next address is O(log n) on the number of |
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ranges, so even a large number of ranges (many thousands) is managable. |
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|
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No storage is allocated per address. |
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|
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Note that, while IPv6 addresses are currently supported, the usefulness of |
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this option is extremely limited and might be gone in future versions - if |
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you want to ping a number of IPv6 hosts, better specify them individually |
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using the C<add_hosts> method. |
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|
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=item $pinger->add_hosts ([$host...], $interval, $interleave) |
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|
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Similar to C<add_range>, but uses a list of single addresses instead. The |
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list is specified as an array reference as first argument. Each entry in |
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the array should be a binary host address, either IPv4 or IPv6. Currently, |
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all entries in the list must be either IPv4 B<OR> IPv6, so you have to |
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create two host ranges if you have mixed addresses. |
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|
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Minimum C<$interval> is the same as for C<add_range> and can be left out. |
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|
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C<$interlave> specifies an increment between addresses: often address |
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lists are generated in a way that results in clustering - first all |
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addresses from one subnet, then from the next, and so on. To avoid this, |
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you can specify an interleave factor. If it is C<1> (the default), then |
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every address is pinged in the order specified. If it is C<2>, then only |
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every second address will be pinged in the first round, followed by a |
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second round with the others. Higher factors will create C<$interleave> |
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runs of addresses spaced C<$interleave> indices in the list. |
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|
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The special value C<0> selects a (hopefully) suitable interleave factor |
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automatically - currently C<256> for lists with less than 65536 addresses, |
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and the square root of the list length otherwise. |
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|
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=item $pinger->start |
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|
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Start the pinger, unless it is running already. While a pinger is running |
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you must not modify the pinger. If you want to change a parameter, you |
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have to C<stop> the pinger first. |
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|
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The pinger will automatically stop when destroyed. |
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|
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=item $pinger->stop |
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|
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Stop the pinger, if it is running. A pinger can be stopped at any time, |
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after which it's current state is preserved - starting it again will |
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continue where it left off. |
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|
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=cut |
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|
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1; |
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|
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=back |
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|
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=head1 AUTHOR |
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|
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Marc Lehmann <schmorp@schmorp.de> |
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http://home.schmorp.de/ |
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|
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=head1 LICENSE |
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|
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This software is distributed under the GENERAL PUBLIC LICENSE, version 2 |
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or any later version or, at your option, the Artistic License. |
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|
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=cut |
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|