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1 | package Net::Ping; |
2 | |
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3 | # $Id: Ping.pm,v 1.46 2002/12/02 19:17:09 rob Exp $ |
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4 | |
5 | require 5.002; |
a0d0e21e |
6 | require Exporter; |
7 | |
a3b93737 |
8 | use strict; |
b124990b |
9 | use vars qw(@ISA @EXPORT $VERSION |
f569508e |
10 | $def_timeout $def_proto $max_datasize $pingstring $hires $source_verify $syn_forking); |
11 | use Fcntl qw( F_GETFL F_SETFL O_NONBLOCK ); |
12 | use Socket qw( SOCK_DGRAM SOCK_STREAM SOCK_RAW PF_INET SOL_SOCKET |
e82f584b |
13 | inet_aton inet_ntoa sockaddr_in ); |
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14 | use POSIX qw( ECONNREFUSED EINPROGRESS EAGAIN WNOHANG ); |
f569508e |
15 | use FileHandle; |
a3b93737 |
16 | use Carp; |
a79c1648 |
17 | |
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18 | @ISA = qw(Exporter); |
a3b93737 |
19 | @EXPORT = qw(pingecho); |
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20 | $VERSION = "2.26"; |
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21 | |
a3b93737 |
22 | # Constants |
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23 | |
a3b93737 |
24 | $def_timeout = 5; # Default timeout to wait for a reply |
a5a165b1 |
25 | $def_proto = "tcp"; # Default protocol to use for pinging |
a3b93737 |
26 | $max_datasize = 1024; # Maximum data bytes in a packet |
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27 | # The data we exchange with the server for the stream protocol |
28 | $pingstring = "pingschwingping!\n"; |
5d20095f |
29 | $source_verify = 1; # Default is to verify source endpoint |
f569508e |
30 | $syn_forking = 0; |
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31 | |
ef73e1db |
32 | if ($^O =~ /Win32/i) { |
33 | # Hack to avoid this Win32 spewage: |
34 | # Your vendor has not defined POSIX macro ECONNREFUSED |
35 | *ECONNREFUSED = sub {10061;}; # "Unknown Error" Special Win32 Response? |
f569508e |
36 | $syn_forking = 1; |
ef73e1db |
37 | }; |
38 | |
f569508e |
39 | # h2ph "asm/socket.h" |
40 | # require "asm/socket.ph"; |
41 | sub SO_BINDTODEVICE {25;} |
42 | |
a3b93737 |
43 | # Description: The pingecho() subroutine is provided for backward |
44 | # compatibility with the original Net::Ping. It accepts a host |
45 | # name/IP and an optional timeout in seconds. Create a tcp ping |
46 | # object and try pinging the host. The result of the ping is returned. |
a0d0e21e |
47 | |
a3b93737 |
48 | sub pingecho |
49 | { |
e82f584b |
50 | my ($host, # Name or IP number of host to ping |
51 | $timeout # Optional timeout in seconds |
52 | ) = @_; |
53 | my ($p); # A ping object |
a0d0e21e |
54 | |
e82f584b |
55 | $p = Net::Ping->new("tcp", $timeout); |
56 | $p->ping($host); # Going out of scope closes the connection |
a3b93737 |
57 | } |
a0d0e21e |
58 | |
a3b93737 |
59 | # Description: The new() method creates a new ping object. Optional |
60 | # parameters may be specified for the protocol to use, the timeout in |
61 | # seconds and the size in bytes of additional data which should be |
62 | # included in the packet. |
63 | # After the optional parameters are checked, the data is constructed |
64 | # and a socket is opened if appropriate. The object is returned. |
65 | |
66 | sub new |
67 | { |
e82f584b |
68 | my ($this, |
69 | $proto, # Optional protocol to use for pinging |
70 | $timeout, # Optional timeout in seconds |
f569508e |
71 | $data_size, # Optional additional bytes of data |
72 | $device, # Optional device to use |
e82f584b |
73 | ) = @_; |
74 | my $class = ref($this) || $this; |
75 | my $self = {}; |
76 | my ($cnt, # Count through data bytes |
77 | $min_datasize # Minimum data bytes required |
78 | ); |
79 | |
80 | bless($self, $class); |
81 | |
82 | $proto = $def_proto unless $proto; # Determine the protocol |
f569508e |
83 | croak('Protocol for ping must be "icmp", "udp", "tcp", "syn", "stream", or "external"') |
84 | unless $proto =~ m/^(icmp|udp|tcp|syn|stream|external)$/; |
e82f584b |
85 | $self->{"proto"} = $proto; |
86 | |
87 | $timeout = $def_timeout unless $timeout; # Determine the timeout |
88 | croak("Default timeout for ping must be greater than 0 seconds") |
89 | if $timeout <= 0; |
90 | $self->{"timeout"} = $timeout; |
91 | |
f569508e |
92 | $self->{"device"} = $device; |
93 | |
e82f584b |
94 | $min_datasize = ($proto eq "udp") ? 1 : 0; # Determine data size |
95 | $data_size = $min_datasize unless defined($data_size) && $proto ne "tcp"; |
96 | croak("Data for ping must be from $min_datasize to $max_datasize bytes") |
97 | if ($data_size < $min_datasize) || ($data_size > $max_datasize); |
98 | $data_size-- if $self->{"proto"} eq "udp"; # We provide the first byte |
99 | $self->{"data_size"} = $data_size; |
100 | |
101 | $self->{"data"} = ""; # Construct data bytes |
102 | for ($cnt = 0; $cnt < $self->{"data_size"}; $cnt++) |
103 | { |
104 | $self->{"data"} .= chr($cnt % 256); |
105 | } |
106 | |
107 | $self->{"local_addr"} = undef; # Don't bind by default |
108 | |
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109 | $self->{"tcp_econnrefused"} = undef; # Default Connection refused behavior |
110 | |
e82f584b |
111 | $self->{"seq"} = 0; # For counting packets |
112 | if ($self->{"proto"} eq "udp") # Open a socket |
113 | { |
114 | $self->{"proto_num"} = (getprotobyname('udp'))[2] || |
115 | croak("Can't udp protocol by name"); |
116 | $self->{"port_num"} = (getservbyname('echo', 'udp'))[2] || |
117 | croak("Can't get udp echo port by name"); |
118 | $self->{"fh"} = FileHandle->new(); |
119 | socket($self->{"fh"}, PF_INET, SOCK_DGRAM, |
120 | $self->{"proto_num"}) || |
121 | croak("udp socket error - $!"); |
f569508e |
122 | if ($self->{'device'}) { |
123 | setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) |
124 | or croak "error binding to device $self->{'device'} $!"; |
125 | } |
e82f584b |
126 | } |
127 | elsif ($self->{"proto"} eq "icmp") |
128 | { |
f569508e |
129 | croak("icmp ping requires root privilege") if ($> and $^O ne 'VMS' and $^O ne 'cygwin'); |
e82f584b |
130 | $self->{"proto_num"} = (getprotobyname('icmp'))[2] || |
131 | croak("Can't get icmp protocol by name"); |
132 | $self->{"pid"} = $$ & 0xffff; # Save lower 16 bits of pid |
133 | $self->{"fh"} = FileHandle->new(); |
134 | socket($self->{"fh"}, PF_INET, SOCK_RAW, $self->{"proto_num"}) || |
135 | croak("icmp socket error - $!"); |
f569508e |
136 | if ($self->{'device'}) { |
137 | setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) |
138 | or croak "error binding to device $self->{'device'} $!"; |
139 | } |
e82f584b |
140 | } |
141 | elsif ($self->{"proto"} eq "tcp" || $self->{"proto"} eq "stream") |
142 | { |
143 | $self->{"proto_num"} = (getprotobyname('tcp'))[2] || |
144 | croak("Can't get tcp protocol by name"); |
145 | $self->{"port_num"} = (getservbyname('echo', 'tcp'))[2] || |
146 | croak("Can't get tcp echo port by name"); |
147 | $self->{"fh"} = FileHandle->new(); |
148 | } |
f569508e |
149 | elsif ($self->{"proto"} eq "syn") |
150 | { |
151 | $self->{"proto_num"} = (getprotobyname('tcp'))[2] || |
152 | croak("Can't get tcp protocol by name"); |
153 | $self->{"port_num"} = (getservbyname('echo', 'tcp'))[2] || |
154 | croak("Can't get tcp echo port by name"); |
155 | if ($syn_forking) { |
156 | $self->{"fork_rd"} = FileHandle->new(); |
157 | $self->{"fork_wr"} = FileHandle->new(); |
158 | pipe($self->{"fork_rd"}, $self->{"fork_wr"}); |
159 | $self->{"fh"} = FileHandle->new(); |
69c74a9c |
160 | $self->{"good"} = {}; |
161 | $self->{"bad"} = {}; |
f569508e |
162 | } else { |
163 | $self->{"wbits"} = ""; |
164 | $self->{"bad"} = {}; |
165 | } |
166 | $self->{"syn"} = {}; |
167 | $self->{"stop_time"} = 0; |
168 | } |
169 | elsif ($self->{"proto"} eq "external") |
170 | { |
171 | # No preliminary work needs to be done. |
172 | } |
e82f584b |
173 | |
174 | return($self); |
a3b93737 |
175 | } |
a0d0e21e |
176 | |
49afa5f6 |
177 | # Description: Set the local IP address from which pings will be sent. |
178 | # For ICMP and UDP pings, this calls bind() on the already-opened socket; |
179 | # for TCP pings, just saves the address to be used when the socket is |
180 | # opened. Returns non-zero if successful; croaks on error. |
181 | sub bind |
182 | { |
e82f584b |
183 | my ($self, |
184 | $local_addr # Name or IP number of local interface |
185 | ) = @_; |
186 | my ($ip # Packed IP number of $local_addr |
187 | ); |
188 | |
189 | croak("Usage: \$p->bind(\$local_addr)") unless @_ == 2; |
190 | croak("already bound") if defined($self->{"local_addr"}) && |
191 | ($self->{"proto"} eq "udp" || $self->{"proto"} eq "icmp"); |
192 | |
193 | $ip = inet_aton($local_addr); |
194 | croak("nonexistent local address $local_addr") unless defined($ip); |
195 | $self->{"local_addr"} = $ip; # Only used if proto is tcp |
196 | |
197 | if ($self->{"proto"} eq "udp" || $self->{"proto"} eq "icmp") |
198 | { |
199 | CORE::bind($self->{"fh"}, sockaddr_in(0, $ip)) || |
200 | croak("$self->{'proto'} bind error - $!"); |
201 | } |
202 | elsif ($self->{"proto"} ne "tcp") |
203 | { |
204 | croak("Unknown protocol \"$self->{proto}\" in bind()"); |
205 | } |
206 | |
207 | return 1; |
208 | } |
49afa5f6 |
209 | |
49afa5f6 |
210 | |
15d96390 |
211 | # Description: Allow UDP source endpoint comparision to be |
212 | # skipped for those remote interfaces that do |
213 | # not response from the same endpoint. |
214 | |
215 | sub source_verify |
216 | { |
217 | my $self = shift; |
5d20095f |
218 | $source_verify = 1 unless defined |
219 | ($source_verify = ((defined $self) && (ref $self)) ? shift() : $self); |
15d96390 |
220 | } |
221 | |
f569508e |
222 | # Description: Set whether or not the tcp connect |
223 | # behavior should enforce remote service availability |
224 | # as well as reachability. |
225 | |
226 | sub tcp_service_check |
227 | { |
228 | my $self = shift; |
229 | $self->{"tcp_econnrefused"} = 1 unless defined |
230 | ($self->{"tcp_econnrefused"} = shift()); |
231 | } |
232 | |
e82f584b |
233 | # Description: allows the module to use milliseconds as returned by |
234 | # the Time::HiRes module |
49afa5f6 |
235 | |
e82f584b |
236 | $hires = 0; |
237 | sub hires |
238 | { |
239 | my $self = shift; |
240 | $hires = 1 unless defined |
241 | ($hires = ((defined $self) && (ref $self)) ? shift() : $self); |
242 | require Time::HiRes if $hires; |
49afa5f6 |
243 | } |
244 | |
e82f584b |
245 | sub time |
246 | { |
247 | return $hires ? Time::HiRes::time() : CORE::time(); |
248 | } |
49afa5f6 |
249 | |
a3b93737 |
250 | # Description: Ping a host name or IP number with an optional timeout. |
251 | # First lookup the host, and return undef if it is not found. Otherwise |
b124990b |
252 | # perform the specific ping method based on the protocol. Return the |
a3b93737 |
253 | # result of the ping. |
254 | |
255 | sub ping |
256 | { |
e82f584b |
257 | my ($self, |
258 | $host, # Name or IP number of host to ping |
259 | $timeout, # Seconds after which ping times out |
260 | ) = @_; |
261 | my ($ip, # Packed IP number of $host |
262 | $ret, # The return value |
263 | $ping_time, # When ping began |
264 | ); |
265 | |
266 | croak("Usage: \$p->ping(\$host [, \$timeout])") unless @_ == 2 || @_ == 3; |
267 | $timeout = $self->{"timeout"} unless $timeout; |
268 | croak("Timeout must be greater than 0 seconds") if $timeout <= 0; |
269 | |
270 | $ip = inet_aton($host); |
271 | return(undef) unless defined($ip); # Does host exist? |
272 | |
273 | # Dispatch to the appropriate routine. |
274 | $ping_time = &time(); |
275 | if ($self->{"proto"} eq "external") { |
276 | $ret = $self->ping_external($ip, $timeout); |
277 | } |
278 | elsif ($self->{"proto"} eq "udp") { |
279 | $ret = $self->ping_udp($ip, $timeout); |
280 | } |
281 | elsif ($self->{"proto"} eq "icmp") { |
282 | $ret = $self->ping_icmp($ip, $timeout); |
283 | } |
284 | elsif ($self->{"proto"} eq "tcp") { |
285 | $ret = $self->ping_tcp($ip, $timeout); |
286 | } |
287 | elsif ($self->{"proto"} eq "stream") { |
288 | $ret = $self->ping_stream($ip, $timeout); |
f569508e |
289 | } |
290 | elsif ($self->{"proto"} eq "syn") { |
291 | $ret = $self->ping_syn($host, $ip, $ping_time, $ping_time+$timeout); |
e82f584b |
292 | } else { |
787ecdfa |
293 | croak("Unknown protocol \"$self->{proto}\" in ping()"); |
e82f584b |
294 | } |
295 | |
296 | return wantarray ? ($ret, &time() - $ping_time, inet_ntoa($ip)) : $ret; |
787ecdfa |
297 | } |
298 | |
299 | # Uses Net::Ping::External to do an external ping. |
300 | sub ping_external { |
301 | my ($self, |
302 | $ip, # Packed IP number of the host |
303 | $timeout # Seconds after which ping times out |
304 | ) = @_; |
305 | |
b124990b |
306 | eval { require Net::Ping::External; } |
307 | or croak('Protocol "external" not supported on your system: Net::Ping::External not found'); |
787ecdfa |
308 | return Net::Ping::External::ping(ip => $ip, timeout => $timeout); |
a3b93737 |
309 | } |
a0d0e21e |
310 | |
49afa5f6 |
311 | use constant ICMP_ECHOREPLY => 0; # ICMP packet types |
312 | use constant ICMP_ECHO => 8; |
313 | use constant ICMP_STRUCT => "C2 S3 A"; # Structure of a minimal ICMP packet |
314 | use constant SUBCODE => 0; # No ICMP subcode for ECHO and ECHOREPLY |
315 | use constant ICMP_FLAGS => 0; # No special flags for send or recv |
316 | use constant ICMP_PORT => 0; # No port with ICMP |
317 | |
a3b93737 |
318 | sub ping_icmp |
319 | { |
e82f584b |
320 | my ($self, |
321 | $ip, # Packed IP number of the host |
322 | $timeout # Seconds after which ping times out |
323 | ) = @_; |
324 | |
325 | my ($saddr, # sockaddr_in with port and ip |
326 | $checksum, # Checksum of ICMP packet |
327 | $msg, # ICMP packet to send |
328 | $len_msg, # Length of $msg |
329 | $rbits, # Read bits, filehandles for reading |
330 | $nfound, # Number of ready filehandles found |
331 | $finish_time, # Time ping should be finished |
332 | $done, # set to 1 when we are done |
333 | $ret, # Return value |
334 | $recv_msg, # Received message including IP header |
335 | $from_saddr, # sockaddr_in of sender |
336 | $from_port, # Port packet was sent from |
337 | $from_ip, # Packed IP of sender |
338 | $from_type, # ICMP type |
339 | $from_subcode, # ICMP subcode |
340 | $from_chk, # ICMP packet checksum |
341 | $from_pid, # ICMP packet id |
342 | $from_seq, # ICMP packet sequence |
343 | $from_msg # ICMP message |
344 | ); |
345 | |
346 | $self->{"seq"} = ($self->{"seq"} + 1) % 65536; # Increment sequence |
347 | $checksum = 0; # No checksum for starters |
348 | $msg = pack(ICMP_STRUCT . $self->{"data_size"}, ICMP_ECHO, SUBCODE, |
349 | $checksum, $self->{"pid"}, $self->{"seq"}, $self->{"data"}); |
350 | $checksum = Net::Ping->checksum($msg); |
351 | $msg = pack(ICMP_STRUCT . $self->{"data_size"}, ICMP_ECHO, SUBCODE, |
352 | $checksum, $self->{"pid"}, $self->{"seq"}, $self->{"data"}); |
353 | $len_msg = length($msg); |
354 | $saddr = sockaddr_in(ICMP_PORT, $ip); |
355 | send($self->{"fh"}, $msg, ICMP_FLAGS, $saddr); # Send the message |
356 | |
357 | $rbits = ""; |
358 | vec($rbits, $self->{"fh"}->fileno(), 1) = 1; |
359 | $ret = 0; |
360 | $done = 0; |
361 | $finish_time = &time() + $timeout; # Must be done by this time |
362 | while (!$done && $timeout > 0) # Keep trying if we have time |
363 | { |
364 | $nfound = select($rbits, undef, undef, $timeout); # Wait for packet |
365 | $timeout = $finish_time - &time(); # Get remaining time |
366 | if (!defined($nfound)) # Hmm, a strange error |
a3b93737 |
367 | { |
e82f584b |
368 | $ret = undef; |
369 | $done = 1; |
370 | } |
371 | elsif ($nfound) # Got a packet from somewhere |
372 | { |
373 | $recv_msg = ""; |
374 | $from_saddr = recv($self->{"fh"}, $recv_msg, 1500, ICMP_FLAGS); |
375 | ($from_port, $from_ip) = sockaddr_in($from_saddr); |
376 | ($from_type, $from_subcode, $from_chk, |
377 | $from_pid, $from_seq, $from_msg) = |
378 | unpack(ICMP_STRUCT . $self->{"data_size"}, |
379 | substr($recv_msg, length($recv_msg) - $len_msg, |
380 | $len_msg)); |
381 | if (($from_type == ICMP_ECHOREPLY) && |
5d20095f |
382 | (!$source_verify || $from_ip eq $ip) && |
e82f584b |
383 | ($from_pid == $self->{"pid"}) && # Does the packet check out? |
384 | ($from_seq == $self->{"seq"})) |
385 | { |
386 | $ret = 1; # It's a winner |
387 | $done = 1; |
388 | } |
a3b93737 |
389 | } |
e82f584b |
390 | else # Oops, timed out |
391 | { |
392 | $done = 1; |
393 | } |
394 | } |
395 | return $ret; |
a3b93737 |
396 | } |
397 | |
398 | # Description: Do a checksum on the message. Basically sum all of |
399 | # the short words and fold the high order bits into the low order bits. |
400 | |
401 | sub checksum |
402 | { |
e82f584b |
403 | my ($class, |
404 | $msg # The message to checksum |
405 | ) = @_; |
406 | my ($len_msg, # Length of the message |
407 | $num_short, # The number of short words in the message |
408 | $short, # One short word |
409 | $chk # The checksum |
410 | ); |
411 | |
412 | $len_msg = length($msg); |
413 | $num_short = int($len_msg / 2); |
414 | $chk = 0; |
415 | foreach $short (unpack("S$num_short", $msg)) |
416 | { |
417 | $chk += $short; |
418 | } # Add the odd byte in |
419 | $chk += (unpack("C", substr($msg, $len_msg - 1, 1)) << 8) if $len_msg % 2; |
420 | $chk = ($chk >> 16) + ($chk & 0xffff); # Fold high into low |
421 | return(~(($chk >> 16) + $chk) & 0xffff); # Again and complement |
a3b93737 |
422 | } |
423 | |
787ecdfa |
424 | |
b124990b |
425 | # Description: Perform a tcp echo ping. Since a tcp connection is |
426 | # host specific, we have to open and close each connection here. We |
427 | # can't just leave a socket open. Because of the robust nature of |
428 | # tcp, it will take a while before it gives up trying to establish a |
429 | # connection. Therefore, we use select() on a non-blocking socket to |
430 | # check against our timeout. No data bytes are actually |
431 | # sent since the successful establishment of a connection is proof |
432 | # enough of the reachability of the remote host. Also, tcp is |
433 | # expensive and doesn't need our help to add to the overhead. |
434 | |
435 | sub ping_tcp |
787ecdfa |
436 | { |
e82f584b |
437 | my ($self, |
438 | $ip, # Packed IP number of the host |
439 | $timeout # Seconds after which ping times out |
440 | ) = @_; |
441 | my ($ret # The return value |
442 | ); |
443 | |
444 | $@ = ""; $! = 0; |
445 | $ret = $self -> tcp_connect( $ip, $timeout); |
f569508e |
446 | if (!$self->{"tcp_econnrefused"} && |
447 | $! == ECONNREFUSED) { |
448 | $ret = 1; # "Connection refused" means reachable |
449 | } |
e82f584b |
450 | $self->{"fh"}->close(); |
451 | return $ret; |
787ecdfa |
452 | } |
453 | |
b124990b |
454 | sub tcp_connect |
787ecdfa |
455 | { |
e82f584b |
456 | my ($self, |
457 | $ip, # Packed IP number of the host |
458 | $timeout # Seconds after which connect times out |
459 | ) = @_; |
460 | my ($saddr); # Packed IP and Port |
b124990b |
461 | |
e82f584b |
462 | $saddr = sockaddr_in($self->{"port_num"}, $ip); |
b124990b |
463 | |
e82f584b |
464 | my $ret = 0; # Default to unreachable |
b124990b |
465 | |
e82f584b |
466 | my $do_socket = sub { |
467 | socket($self->{"fh"}, PF_INET, SOCK_STREAM, $self->{"proto_num"}) || |
468 | croak("tcp socket error - $!"); |
469 | if (defined $self->{"local_addr"} && |
470 | !CORE::bind($self->{"fh"}, sockaddr_in(0, $self->{"local_addr"}))) { |
471 | croak("tcp bind error - $!"); |
472 | } |
f569508e |
473 | if ($self->{'device'}) { |
474 | setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) |
475 | or croak("error binding to device $self->{'device'} $!"); |
476 | } |
e82f584b |
477 | }; |
478 | my $do_connect = sub { |
479 | eval { |
480 | die $! unless connect($self->{"fh"}, $saddr); |
481 | $self->{"ip"} = $ip; |
482 | $ret = 1; |
483 | }; |
484 | $ret; |
485 | }; |
486 | |
487 | if ($^O =~ /Win32/i) { |
488 | |
489 | # Buggy Winsock API doesn't allow us to use alarm() calls. |
490 | # Hence, if our OS is Windows, we need to create a separate |
491 | # process to do the blocking connect attempt. |
492 | |
493 | $| = 1; # Clear buffer prior to fork to prevent duplicate flushing. |
494 | my $pid = fork; |
495 | if (!$pid) { |
496 | if (!defined $pid) { |
497 | # Fork did not work |
498 | warn "Win32 Fork error: $!"; |
499 | return 0; |
b124990b |
500 | } |
b124990b |
501 | &{ $do_socket }(); |
502 | |
e82f584b |
503 | # Try a slow blocking connect() call |
504 | # and report the status to the pipe. |
505 | if ( &{ $do_connect }() ) { |
506 | $self->{"fh"}->close(); |
507 | # No error |
508 | exit 0; |
b124990b |
509 | } else { |
e82f584b |
510 | # Pass the error status to the parent |
511 | exit $!; |
b124990b |
512 | } |
e82f584b |
513 | } |
b124990b |
514 | |
e82f584b |
515 | &{ $do_socket }(); |
516 | |
517 | my $patience = &time() + $timeout; |
518 | |
e82f584b |
519 | my ($child); |
520 | $? = 0; |
521 | # Wait up to the timeout |
522 | # And clean off the zombie |
523 | do { |
f569508e |
524 | $child = waitpid($pid, &WNOHANG()); |
e82f584b |
525 | $! = $? >> 8; |
526 | $@ = $!; |
527 | select(undef, undef, undef, 0.1); |
528 | } while &time() < $patience && $child != $pid; |
529 | |
530 | if ($child == $pid) { |
531 | # Since she finished within the timeout, |
532 | # it is probably safe for me to try it too |
b124990b |
533 | &{ $do_connect }(); |
e82f584b |
534 | } else { |
535 | # Time must have run out. |
536 | $@ = "Timed out!"; |
537 | # Put that choking client out of its misery |
538 | kill "KILL", $pid; |
539 | # Clean off the zombie |
540 | waitpid($pid, 0); |
541 | $ret = 0; |
b124990b |
542 | } |
e82f584b |
543 | } else { # Win32 |
544 | # Otherwise don't waste the resources to fork |
545 | |
546 | &{ $do_socket }(); |
547 | |
f569508e |
548 | local $SIG{'ALRM'} = sub { die "Timed out!"; }; |
549 | my $old = alarm($timeout); # Interrupt connect() if we have to |
e82f584b |
550 | |
551 | &{ $do_connect }(); |
f569508e |
552 | alarm($old); |
e82f584b |
553 | } |
787ecdfa |
554 | |
e82f584b |
555 | return $ret; |
787ecdfa |
556 | } |
557 | |
558 | # This writes the given string to the socket and then reads it |
559 | # back. It returns 1 on success, 0 on failure. |
560 | sub tcp_echo |
561 | { |
e82f584b |
562 | my $self = shift; |
563 | my $timeout = shift; |
564 | my $pingstring = shift; |
565 | |
566 | my $ret = undef; |
567 | my $time = &time(); |
568 | my $wrstr = $pingstring; |
569 | my $rdstr = ""; |
570 | |
571 | eval <<'EOM'; |
572 | do { |
573 | my $rin = ""; |
574 | vec($rin, $self->{"fh"}->fileno(), 1) = 1; |
575 | |
576 | my $rout = undef; |
577 | if($wrstr) { |
578 | $rout = ""; |
579 | vec($rout, $self->{"fh"}->fileno(), 1) = 1; |
580 | } |
581 | |
582 | if(select($rin, $rout, undef, ($time + $timeout) - &time())) { |
583 | |
584 | if($rout && vec($rout,$self->{"fh"}->fileno(),1)) { |
585 | my $num = syswrite($self->{"fh"}, $wrstr); |
586 | if($num) { |
587 | # If it was a partial write, update and try again. |
588 | $wrstr = substr($wrstr,$num); |
589 | } else { |
590 | # There was an error. |
591 | $ret = 0; |
592 | } |
593 | } |
594 | |
595 | if(vec($rin,$self->{"fh"}->fileno(),1)) { |
596 | my $reply; |
597 | if(sysread($self->{"fh"},$reply,length($pingstring)-length($rdstr))) { |
598 | $rdstr .= $reply; |
599 | $ret = 1 if $rdstr eq $pingstring; |
600 | } else { |
601 | # There was an error. |
602 | $ret = 0; |
603 | } |
604 | } |
605 | |
606 | } |
607 | } until &time() > ($time + $timeout) || defined($ret); |
787ecdfa |
608 | EOM |
609 | |
e82f584b |
610 | return $ret; |
787ecdfa |
611 | } |
612 | |
787ecdfa |
613 | |
787ecdfa |
614 | |
787ecdfa |
615 | |
616 | # Description: Perform a stream ping. If the tcp connection isn't |
617 | # already open, it opens it. It then sends some data and waits for |
618 | # a reply. It leaves the stream open on exit. |
619 | |
620 | sub ping_stream |
621 | { |
e82f584b |
622 | my ($self, |
623 | $ip, # Packed IP number of the host |
624 | $timeout # Seconds after which ping times out |
625 | ) = @_; |
072620d9 |
626 | |
e82f584b |
627 | # Open the stream if it's not already open |
628 | if(!defined $self->{"fh"}->fileno()) { |
629 | $self->tcp_connect($ip, $timeout) or return 0; |
630 | } |
787ecdfa |
631 | |
e82f584b |
632 | croak "tried to switch servers while stream pinging" |
633 | if $self->{"ip"} ne $ip; |
634 | |
635 | return $self->tcp_echo($timeout, $pingstring); |
787ecdfa |
636 | } |
637 | |
638 | # Description: opens the stream. You would do this if you want to |
639 | # separate the overhead of opening the stream from the first ping. |
640 | |
641 | sub open |
642 | { |
e82f584b |
643 | my ($self, |
644 | $host, # Host or IP address |
645 | $timeout # Seconds after which open times out |
646 | ) = @_; |
647 | |
648 | my ($ip); # Packed IP number of the host |
649 | $ip = inet_aton($host); |
650 | $timeout = $self->{"timeout"} unless $timeout; |
651 | |
652 | if($self->{"proto"} eq "stream") { |
653 | if(defined($self->{"fh"}->fileno())) { |
654 | croak("socket is already open"); |
655 | } else { |
656 | $self->tcp_connect($ip, $timeout); |
b124990b |
657 | } |
e82f584b |
658 | } |
072620d9 |
659 | } |
660 | |
b124990b |
661 | |
a3b93737 |
662 | # Description: Perform a udp echo ping. Construct a message of |
663 | # at least the one-byte sequence number and any additional data bytes. |
664 | # Send the message out and wait for a message to come back. If we |
665 | # get a message, make sure all of its parts match. If they do, we are |
666 | # done. Otherwise go back and wait for the message until we run out |
667 | # of time. Return the result of our efforts. |
668 | |
49afa5f6 |
669 | use constant UDP_FLAGS => 0; # Nothing special on send or recv |
69c74a9c |
670 | # XXX - Use concept by rdw @ perlmonks |
671 | # http://perlmonks.thepen.com/42898.html |
a3b93737 |
672 | sub ping_udp |
673 | { |
e82f584b |
674 | my ($self, |
675 | $ip, # Packed IP number of the host |
676 | $timeout # Seconds after which ping times out |
677 | ) = @_; |
678 | |
679 | my ($saddr, # sockaddr_in with port and ip |
680 | $ret, # The return value |
681 | $msg, # Message to be echoed |
682 | $finish_time, # Time ping should be finished |
e82f584b |
683 | $done, # Set to 1 when we are done pinging |
684 | $rbits, # Read bits, filehandles for reading |
685 | $nfound, # Number of ready filehandles found |
686 | $from_saddr, # sockaddr_in of sender |
687 | $from_msg, # Characters echoed by $host |
688 | $from_port, # Port message was echoed from |
689 | $from_ip # Packed IP number of sender |
690 | ); |
691 | |
692 | $saddr = sockaddr_in($self->{"port_num"}, $ip); |
693 | $self->{"seq"} = ($self->{"seq"} + 1) % 256; # Increment sequence |
694 | $msg = chr($self->{"seq"}) . $self->{"data"}; # Add data if any |
695 | send($self->{"fh"}, $msg, UDP_FLAGS, $saddr); # Send it |
696 | |
697 | $rbits = ""; |
698 | vec($rbits, $self->{"fh"}->fileno(), 1) = 1; |
699 | $ret = 0; # Default to unreachable |
700 | $done = 0; |
e82f584b |
701 | $finish_time = &time() + $timeout; # Ping needs to be done by then |
702 | while (!$done && $timeout > 0) |
703 | { |
704 | $nfound = select($rbits, undef, undef, $timeout); # Wait for response |
705 | $timeout = $finish_time - &time(); # Get remaining time |
706 | |
707 | if (!defined($nfound)) # Hmm, a strange error |
a3b93737 |
708 | { |
e82f584b |
709 | $ret = undef; |
710 | $done = 1; |
a3b93737 |
711 | } |
e82f584b |
712 | elsif ($nfound) # A packet is waiting |
713 | { |
714 | $from_msg = ""; |
715 | $from_saddr = recv($self->{"fh"}, $from_msg, 1500, UDP_FLAGS) |
716 | or last; # For example an unreachable host will make recv() fail. |
717 | ($from_port, $from_ip) = sockaddr_in($from_saddr); |
5d20095f |
718 | if (!$source_verify || |
15d96390 |
719 | (($from_ip eq $ip) && # Does the packet check out? |
720 | ($from_port == $self->{"port_num"}) && |
721 | ($from_msg eq $msg))) |
e82f584b |
722 | { |
723 | $ret = 1; # It's a winner |
724 | $done = 1; |
725 | } |
726 | } |
727 | else # Oops, timed out |
728 | { |
729 | $done = 1; |
730 | } |
731 | } |
a5a165b1 |
732 | return $ret; |
b124990b |
733 | } |
a0d0e21e |
734 | |
f569508e |
735 | # Description: Send a TCP SYN packet to host specified. |
736 | sub ping_syn |
737 | { |
738 | my $self = shift; |
739 | my $host = shift; |
740 | my $ip = shift; |
741 | my $start_time = shift; |
742 | my $stop_time = shift; |
743 | |
744 | if ($syn_forking) { |
745 | return $self->ping_syn_fork($host, $ip, $start_time, $stop_time); |
746 | } |
747 | |
748 | my $fh = FileHandle->new(); |
749 | my $saddr = sockaddr_in($self->{"port_num"}, $ip); |
750 | |
751 | # Create TCP socket |
752 | if (!socket ($fh, PF_INET, SOCK_STREAM, $self->{"proto_num"})) { |
753 | croak("tcp socket error - $!"); |
754 | } |
755 | |
756 | if (defined $self->{"local_addr"} && |
757 | !CORE::bind($fh, sockaddr_in(0, $self->{"local_addr"}))) { |
758 | croak("tcp bind error - $!"); |
759 | } |
760 | |
761 | if ($self->{'device'}) { |
762 | setsockopt($fh, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) |
763 | or croak("error binding to device $self->{'device'} $!"); |
764 | } |
765 | |
766 | # Set O_NONBLOCK property on filehandle |
69c74a9c |
767 | my $flags = 0; |
768 | if (fcntl($fh, F_GETFL, $flags)) { |
769 | if (!fcntl($fh, F_SETFL, $flags | O_NONBLOCK)) { |
770 | croak("fcntl F_SETFL: $!"); |
771 | } |
f569508e |
772 | } else { |
773 | croak("fcntl F_GETFL: $!"); |
774 | } |
775 | |
776 | # Attempt the non-blocking connect |
777 | # by just sending the TCP SYN packet |
778 | if (connect($fh, $saddr)) { |
779 | # Non-blocking, yet still connected? |
69c74a9c |
780 | # Must have connected very quickly, |
781 | # or else it wasn't very non-blocking. |
782 | #warn "WARNING: Nonblocking connect connected anyway? ($^O)"; |
783 | } else { |
f569508e |
784 | # Error occurred connecting. |
69c74a9c |
785 | if ($! == EINPROGRESS) { |
786 | # The connection is just still in progress. |
787 | # This is the expected condition. |
788 | } else { |
789 | # Just save the error and continue on. |
790 | # The ack() can check the status later. |
f569508e |
791 | $self->{"bad"}->{$host} = $!; |
f569508e |
792 | } |
793 | } |
794 | |
795 | my $entry = [ $host, $ip, $fh, $start_time, $stop_time ]; |
796 | $self->{"syn"}->{$fh->fileno} = $entry; |
797 | if ($self->{"stop_time"} < $stop_time) { |
798 | $self->{"stop_time"} = $stop_time; |
799 | } |
800 | vec($self->{"wbits"}, $fh->fileno, 1) = 1; |
801 | |
802 | return 1; |
803 | } |
804 | |
805 | sub ping_syn_fork { |
806 | my ($self, $host, $ip, $start_time, $stop_time) = @_; |
807 | |
808 | # Buggy Winsock API doesn't allow nonblocking connect. |
809 | # Hence, if our OS is Windows, we need to create a separate |
810 | # process to do the blocking connect attempt. |
811 | my $pid = fork(); |
812 | if (defined $pid) { |
813 | if ($pid) { |
814 | # Parent process |
815 | my $entry = [ $host, $ip, $pid, $start_time, $stop_time ]; |
816 | $self->{"syn"}->{$pid} = $entry; |
817 | if ($self->{"stop_time"} < $stop_time) { |
818 | $self->{"stop_time"} = $stop_time; |
819 | } |
820 | } else { |
821 | # Child process |
822 | my $saddr = sockaddr_in($self->{"port_num"}, $ip); |
823 | |
824 | # Create TCP socket |
825 | if (!socket ($self->{"fh"}, PF_INET, SOCK_STREAM, $self->{"proto_num"})) { |
826 | croak("tcp socket error - $!"); |
827 | } |
828 | |
829 | if (defined $self->{"local_addr"} && |
830 | !CORE::bind($self->{"fh"}, sockaddr_in(0, $self->{"local_addr"}))) { |
831 | croak("tcp bind error - $!"); |
832 | } |
833 | |
834 | if ($self->{'device'}) { |
835 | setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) |
836 | or croak("error binding to device $self->{'device'} $!"); |
837 | } |
838 | |
839 | $!=0; |
840 | # Try to connect (could take a long time) |
841 | connect($self->{"fh"}, $saddr); |
842 | # Notify parent of connect error status |
843 | my $err = $!+0; |
844 | my $wrstr = "$$ $err"; |
845 | # Force to 10 chars including \n |
846 | $wrstr .= " "x(9 - length $wrstr). "\n"; |
847 | syswrite($self->{"fork_wr"}, $wrstr); |
848 | exit; |
849 | } |
850 | } else { |
851 | # fork() failed? |
852 | die "fork: $!"; |
853 | } |
854 | return 1; |
855 | } |
856 | |
857 | # Description: Wait for TCP ACK from host specified |
858 | # from ping_syn above. If no host is specified, wait |
859 | # for TCP ACK from any of the hosts in the SYN queue. |
860 | sub ack |
861 | { |
862 | my $self = shift; |
863 | |
864 | if ($self->{"proto"} eq "syn") { |
865 | if ($syn_forking) { |
866 | my @answer = $self->ack_unfork(shift); |
867 | return wantarray ? @answer : $answer[0]; |
868 | } |
869 | my $wbits = ""; |
870 | my $stop_time = 0; |
871 | if (my $host = shift) { |
872 | # Host passed as arg |
873 | if (exists $self->{"bad"}->{$host}) { |
69c74a9c |
874 | if (!$self->{"tcp_econnrefused"} && |
875 | $self->{"bad"}->{ $host } && |
876 | (($! = ECONNREFUSED)>0) && |
877 | $self->{"bad"}->{ $host } eq "$!") { |
878 | # "Connection refused" means reachable |
879 | # Good, continue |
880 | } else { |
881 | # ECONNREFUSED means no good |
882 | return (); |
883 | } |
f569508e |
884 | } |
885 | my $host_fd = undef; |
886 | foreach my $fd (keys %{ $self->{"syn"} }) { |
887 | my $entry = $self->{"syn"}->{$fd}; |
888 | if ($entry->[0] eq $host) { |
889 | $host_fd = $fd; |
890 | $stop_time = $entry->[4] |
891 | || croak("Corrupted SYN entry for [$host]"); |
892 | last; |
893 | } |
894 | } |
895 | croak("ack called on [$host] without calling ping first!") |
896 | unless defined $host_fd; |
897 | vec($wbits, $host_fd, 1) = 1; |
898 | } else { |
899 | # No $host passed so scan all hosts |
900 | # Use the latest stop_time |
901 | $stop_time = $self->{"stop_time"}; |
902 | # Use all the bits |
903 | $wbits = $self->{"wbits"}; |
904 | } |
905 | |
906 | while ($wbits !~ /^\0*$/) { |
907 | my $timeout = $stop_time - &time(); |
908 | # Force a minimum of 10 ms timeout. |
69c74a9c |
909 | $timeout = 0.01 if $timeout <= 0.01; |
910 | |
911 | my $winner_fd = undef; |
912 | my $wout = $wbits; |
913 | my $fd = 0; |
914 | # Do "bad" fds from $wbits first |
915 | while ($wout !~ /^\0*$/) { |
916 | if (vec($wout, $fd, 1)) { |
917 | # Wipe it from future scanning. |
918 | vec($wout, $fd, 1) = 0; |
919 | if (my $entry = $self->{"syn"}->{$fd}) { |
920 | if ($self->{"bad"}->{ $entry->[0] }) { |
921 | $winner_fd = $fd; |
922 | last; |
923 | } |
924 | } |
925 | } |
926 | $fd++; |
927 | } |
928 | |
929 | if (defined($winner_fd) or my $nfound = select(undef, ($wout=$wbits), undef, $timeout)) { |
930 | if (defined $winner_fd) { |
931 | $fd = $winner_fd; |
932 | } else { |
933 | # Done waiting for one of the ACKs |
934 | $fd = 0; |
935 | # Determine which one |
936 | while ($wout !~ /^\0*$/ && |
937 | !vec($wout, $fd, 1)) { |
938 | $fd++; |
939 | } |
f569508e |
940 | } |
941 | if (my $entry = $self->{"syn"}->{$fd}) { |
69c74a9c |
942 | # Wipe it from future scanning. |
943 | delete $self->{"syn"}->{$fd}; |
944 | vec($self->{"wbits"}, $fd, 1) = 0; |
945 | vec($wbits, $fd, 1) = 0; |
946 | if (!$self->{"tcp_econnrefused"} && |
947 | $self->{"bad"}->{ $entry->[0] } && |
948 | (($! = ECONNREFUSED)>0) && |
949 | $self->{"bad"}->{ $entry->[0] } eq "$!") { |
950 | # "Connection refused" means reachable |
951 | # Good, continue |
952 | } elsif (getpeername($entry->[2])) { |
f569508e |
953 | # Connection established to remote host |
69c74a9c |
954 | # Good, continue |
f569508e |
955 | } else { |
956 | # TCP ACK will never come from this host |
957 | # because there was an error connecting. |
958 | |
f569508e |
959 | # This should set $! to the correct error. |
960 | my $char; |
961 | read($entry->[2],$char,1); |
962 | # Store the excuse why the connection failed. |
963 | $self->{"bad"}->{$entry->[0]} = $!; |
964 | if (!$self->{"tcp_econnrefused"} && |
69c74a9c |
965 | (($! == ECONNREFUSED) || |
966 | ($! == EAGAIN && $^O =~ /cygwin/i))) { |
f569508e |
967 | # "Connection refused" means reachable |
69c74a9c |
968 | # Good, continue |
969 | } else { |
970 | # No good, try the next socket... |
971 | next; |
f569508e |
972 | } |
f569508e |
973 | } |
69c74a9c |
974 | # Everything passed okay, return the answer |
975 | return wantarray ? |
976 | ($entry->[0], &time() - $entry->[3], inet_ntoa($entry->[1])) |
977 | : $entry->[0]; |
f569508e |
978 | } else { |
979 | warn "Corrupted SYN entry: unknown fd [$fd] ready!"; |
980 | vec($wbits, $fd, 1) = 0; |
981 | vec($self->{"wbits"}, $fd, 1) = 0; |
982 | } |
983 | } elsif (defined $nfound) { |
984 | # Timed out waiting for ACK |
985 | foreach my $fd (keys %{ $self->{"syn"} }) { |
986 | if (vec($wbits, $fd, 1)) { |
987 | my $entry = $self->{"syn"}->{$fd}; |
988 | $self->{"bad"}->{$entry->[0]} = "Timed out"; |
989 | vec($wbits, $fd, 1) = 0; |
990 | vec($self->{"wbits"}, $fd, 1) = 0; |
991 | delete $self->{"syn"}->{$fd}; |
992 | } |
993 | } |
994 | } else { |
995 | # Weird error occurred with select() |
996 | warn("select: $!"); |
997 | $self->{"syn"} = {}; |
998 | $wbits = ""; |
999 | } |
1000 | } |
1001 | } |
1002 | return (); |
1003 | } |
1004 | |
1005 | sub ack_unfork { |
69c74a9c |
1006 | my ($self,$host) = @_; |
f569508e |
1007 | my $stop_time = $self->{"stop_time"}; |
69c74a9c |
1008 | if ($host) { |
f569508e |
1009 | # Host passed as arg |
69c74a9c |
1010 | if (my $entry = $self->{"good"}->{$host}) { |
1011 | delete $self->{"good"}->{$host}; |
1012 | return ($entry->[0], &time() - $entry->[3], inet_ntoa($entry->[1])); |
1013 | } |
f569508e |
1014 | } |
1015 | |
1016 | my $rbits = ""; |
1017 | my $timeout; |
69c74a9c |
1018 | |
f569508e |
1019 | if (keys %{ $self->{"syn"} }) { |
1020 | # Scan all hosts that are left |
1021 | vec($rbits, fileno($self->{"fork_rd"}), 1) = 1; |
1022 | $timeout = $stop_time - &time(); |
69c74a9c |
1023 | # Force a minimum of 10 ms timeout. |
1024 | $timeout = 0.01 if $timeout < 0.01; |
f569508e |
1025 | } else { |
1026 | # No hosts left to wait for |
1027 | $timeout = 0; |
1028 | } |
1029 | |
1030 | if ($timeout > 0) { |
69c74a9c |
1031 | my $nfound; |
1032 | while ( keys %{ $self->{"syn"} } and |
1033 | $nfound = select((my $rout=$rbits), undef, undef, $timeout)) { |
f569508e |
1034 | # Done waiting for one of the ACKs |
1035 | if (!sysread($self->{"fork_rd"}, $_, 10)) { |
1036 | # Socket closed, which means all children are done. |
1037 | return (); |
1038 | } |
1039 | my ($pid, $how) = split; |
1040 | if ($pid) { |
1041 | # Flush the zombie |
1042 | waitpid($pid, 0); |
1043 | if (my $entry = $self->{"syn"}->{$pid}) { |
1044 | # Connection attempt to remote host is done |
1045 | delete $self->{"syn"}->{$pid}; |
1046 | if (!$how || # If there was no error connecting |
1047 | (!$self->{"tcp_econnrefused"} && |
1048 | $how == ECONNREFUSED)) { # "Connection refused" means reachable |
69c74a9c |
1049 | if ($host && $entry->[0] ne $host) { |
1050 | # A good connection, but not the host we need. |
1051 | # Move it from the "syn" hash to the "good" hash. |
1052 | $self->{"good"}->{$entry->[0]} = $entry; |
1053 | # And wait for the next winner |
1054 | next; |
1055 | } |
f569508e |
1056 | return ($entry->[0], &time() - $entry->[3], inet_ntoa($entry->[1])); |
1057 | } |
1058 | } else { |
1059 | # Should never happen |
1060 | die "Unknown ping from pid [$pid]"; |
1061 | } |
1062 | } else { |
1063 | die "Empty response from status socket?"; |
1064 | } |
69c74a9c |
1065 | } |
1066 | if (defined $nfound) { |
f569508e |
1067 | # Timed out waiting for ACK status |
1068 | } else { |
1069 | # Weird error occurred with select() |
1070 | warn("select: $!"); |
1071 | } |
1072 | } |
1073 | if (my @synners = keys %{ $self->{"syn"} }) { |
1074 | # Kill all the synners |
1075 | kill 9, @synners; |
1076 | foreach my $pid (@synners) { |
1077 | # Wait for the deaths to finish |
1078 | # Then flush off the zombie |
1079 | waitpid($pid, 0); |
1080 | } |
1081 | } |
1082 | $self->{"syn"} = {}; |
1083 | return (); |
1084 | } |
1085 | |
1086 | # Description: Tell why the ack() failed |
1087 | sub nack { |
1088 | my $self = shift; |
1089 | my $host = shift || croak('Usage> nack($failed_ack_host)'); |
1090 | return $self->{"bad"}->{$host} || undef; |
1091 | } |
1092 | |
1093 | # Description: Close the connection. |
a3b93737 |
1094 | |
1095 | sub close |
1096 | { |
e82f584b |
1097 | my ($self) = @_; |
a3b93737 |
1098 | |
f569508e |
1099 | if ($self->{"proto"} eq "syn") { |
1100 | delete $self->{"syn"}; |
1101 | } elsif ($self->{"proto"} eq "tcp") { |
1102 | # The connection will already be closed |
1103 | } else { |
1104 | $self->{"fh"}->close(); |
1105 | } |
a3b93737 |
1106 | } |
1107 | |
1108 | |
a0d0e21e |
1109 | 1; |
8e07c86e |
1110 | __END__ |
1111 | |
8e07c86e |
1112 | =head1 NAME |
1113 | |
a3b93737 |
1114 | Net::Ping - check a remote host for reachability |
8e07c86e |
1115 | |
69c74a9c |
1116 | $Id: Ping.pm,v 1.46 2002/12/02 19:17:09 rob Exp $ |
b124990b |
1117 | |
8e07c86e |
1118 | =head1 SYNOPSIS |
1119 | |
1120 | use Net::Ping; |
8e07c86e |
1121 | |
a3b93737 |
1122 | $p = Net::Ping->new(); |
1123 | print "$host is alive.\n" if $p->ping($host); |
1124 | $p->close(); |
1125 | |
1126 | $p = Net::Ping->new("icmp"); |
49afa5f6 |
1127 | $p->bind($my_addr); # Specify source interface of pings |
a3b93737 |
1128 | foreach $host (@host_array) |
1129 | { |
1130 | print "$host is "; |
1131 | print "NOT " unless $p->ping($host, 2); |
1132 | print "reachable.\n"; |
1133 | sleep(1); |
1134 | } |
1135 | $p->close(); |
b124990b |
1136 | |
a3b93737 |
1137 | $p = Net::Ping->new("tcp", 2); |
b124990b |
1138 | # Try connecting to the www port instead of the echo port |
1139 | $p->{port_num} = getservbyname("http", "tcp"); |
a3b93737 |
1140 | while ($stop_time > time()) |
1141 | { |
1142 | print "$host not reachable ", scalar(localtime()), "\n" |
1143 | unless $p->ping($host); |
1144 | sleep(300); |
1145 | } |
1146 | undef($p); |
b124990b |
1147 | |
f569508e |
1148 | # Like tcp protocol, but with many hosts |
1149 | $p = Net::Ping->new("syn"); |
1150 | $p->{port_num} = getservbyname("http", "tcp"); |
1151 | foreach $host (@host_array) { |
1152 | $p->ping($host); |
1153 | } |
1154 | while (($host,$rtt,$ip) = $p->ack) { |
1155 | print "HOST: $host [$ip] ACKed in $rtt seconds.\n"; |
1156 | } |
1157 | |
e82f584b |
1158 | # High precision syntax (requires Time::HiRes) |
1159 | $p = Net::Ping->new(); |
1160 | $p->hires(); |
1161 | ($ret, $duration, $ip) = $p->ping($host, 5.5); |
1162 | printf("$host [ip: $ip] is alive (packet return time: %.2f ms)\n", 1000 * $duration) |
1163 | if $ret; |
1164 | $p->close(); |
1165 | |
a3b93737 |
1166 | # For backward compatibility |
1167 | print "$host is alive.\n" if pingecho($host); |
8e07c86e |
1168 | |
a3b93737 |
1169 | =head1 DESCRIPTION |
8e07c86e |
1170 | |
a3b93737 |
1171 | This module contains methods to test the reachability of remote |
1172 | hosts on a network. A ping object is first created with optional |
1173 | parameters, a variable number of hosts may be pinged multiple |
1174 | times and then the connection is closed. |
1175 | |
f569508e |
1176 | You may choose one of six different protocols to use for the |
1177 | ping. The "tcp" protocol is the default. Note that a live remote host |
b124990b |
1178 | may still fail to be pingable by one or more of these protocols. For |
f569508e |
1179 | example, www.microsoft.com is generally alive but not "icmp" pingable. |
787ecdfa |
1180 | |
b124990b |
1181 | With the "tcp" protocol the ping() method attempts to establish a |
1182 | connection to the remote host's echo port. If the connection is |
1183 | successfully established, the remote host is considered reachable. No |
1184 | data is actually echoed. This protocol does not require any special |
1185 | privileges but has higher overhead than the other two protocols. |
072620d9 |
1186 | |
b124990b |
1187 | Specifying the "udp" protocol causes the ping() method to send a udp |
a3b93737 |
1188 | packet to the remote host's echo port. If the echoed packet is |
1189 | received from the remote host and the received packet contains the |
1190 | same data as the packet that was sent, the remote host is considered |
1191 | reachable. This protocol does not require any special privileges. |
b124990b |
1192 | It should be borne in mind that, for a udp ping, a host |
787ecdfa |
1193 | will be reported as unreachable if it is not running the |
b124990b |
1194 | appropriate echo service. For Unix-like systems see L<inetd(8)> |
1195 | for more information. |
787ecdfa |
1196 | |
b124990b |
1197 | If the "icmp" protocol is specified, the ping() method sends an icmp |
1198 | echo message to the remote host, which is what the UNIX ping program |
1199 | does. If the echoed message is received from the remote host and |
1200 | the echoed information is correct, the remote host is considered |
1201 | reachable. Specifying the "icmp" protocol requires that the program |
1202 | be run as root or that the program be setuid to root. |
787ecdfa |
1203 | |
b124990b |
1204 | If the "external" protocol is specified, the ping() method attempts to |
1205 | use the C<Net::Ping::External> module to ping the remote host. |
1206 | C<Net::Ping::External> interfaces with your system's default C<ping> |
1207 | utility to perform the ping, and generally produces relatively |
787ecdfa |
1208 | accurate results. If C<Net::Ping::External> if not installed on your |
1209 | system, specifying the "external" protocol will result in an error. |
edc5bd88 |
1210 | |
f569508e |
1211 | If the "syn" protocol is specified, the ping() method will only |
1212 | send a TCP SYN packet to the remote host then immediately return. |
1213 | If the syn packet was sent successfully, it will return a true value, |
1214 | otherwise it will return false. NOTE: Unlike the other protocols, |
1215 | the return value does NOT determine if the remote host is alive or |
1216 | not since the full TCP three-way handshake may not have completed |
1217 | yet. The remote host is only considered reachable if it receives |
1218 | a TCP ACK within the timeout specifed. To begin waiting for the |
1219 | ACK packets, use the ack() method as explained below. Use the |
1220 | "syn" protocol instead the "tcp" protocol to determine reachability |
1221 | of multiple destinations simultaneously by sending parallel TCP |
1222 | SYN packets. It will not block while testing each remote host. |
1223 | demo/fping is provided in this distribution to demonstrate the |
1224 | "syn" protocol as an example. |
1225 | This protocol does not require any special privileges. |
1226 | |
a3b93737 |
1227 | =head2 Functions |
1228 | |
1229 | =over 4 |
1230 | |
f569508e |
1231 | =item Net::Ping->new([$proto [, $def_timeout [, $bytes [, $device ]]]]); |
a3b93737 |
1232 | |
1233 | Create a new ping object. All of the parameters are optional. $proto |
1234 | specifies the protocol to use when doing a ping. The current choices |
f569508e |
1235 | are "tcp", "udp", "icmp", "stream", "syn", or "external". |
1236 | The default is "tcp". |
a3b93737 |
1237 | |
1238 | If a default timeout ($def_timeout) in seconds is provided, it is used |
1239 | when a timeout is not given to the ping() method (below). The timeout |
1240 | must be greater than 0 and the default, if not specified, is 5 seconds. |
1241 | |
1242 | If the number of data bytes ($bytes) is given, that many data bytes |
1243 | are included in the ping packet sent to the remote host. The number of |
1244 | data bytes is ignored if the protocol is "tcp". The minimum (and |
1245 | default) number of data bytes is 1 if the protocol is "udp" and 0 |
1246 | otherwise. The maximum number of data bytes that can be specified is |
1247 | 1024. |
1248 | |
f569508e |
1249 | If $device is given, this device is used to bind the source endpoint |
1250 | before sending the ping packet. I beleive this only works with |
1251 | superuser privileges and with udp and icmp protocols at this time. |
1252 | |
5d20095f |
1253 | =item $p->ping($host [, $timeout]); |
1254 | |
1255 | Ping the remote host and wait for a response. $host can be either the |
1256 | hostname or the IP number of the remote host. The optional timeout |
1257 | must be greater than 0 seconds and defaults to whatever was specified |
1258 | when the ping object was created. Returns a success flag. If the |
1259 | hostname cannot be found or there is a problem with the IP number, the |
1260 | success flag returned will be undef. Otherwise, the success flag will |
1261 | be 1 if the host is reachable and 0 if it is not. For most practical |
1262 | purposes, undef and 0 and can be treated as the same case. In array |
f569508e |
1263 | context, the elapsed time as well as the string form of the ip the |
1264 | host resolved to are also returned. The elapsed time value will |
5d20095f |
1265 | be a float, as retuned by the Time::HiRes::time() function, if hires() |
1266 | has been previously called, otherwise it is returned as an integer. |
1267 | |
15d96390 |
1268 | =item $p->source_verify( { 0 | 1 } ); |
1269 | |
1270 | Allows source endpoint verification to be enabled or disabled. |
1271 | This is useful for those remote destinations with multiples |
1272 | interfaces where the response may not originate from the same |
1273 | endpoint that the original destination endpoint was sent to. |
5d20095f |
1274 | This only affects udp and icmp protocol pings. |
15d96390 |
1275 | |
1276 | This is enabled by default. |
1277 | |
f569508e |
1278 | =item $p->tcp_service_check( { 0 | 1 } ); |
1279 | |
1280 | Set whether or not the tcp connect behavior should enforce |
1281 | remote service availability as well as reachability. Normally, |
1282 | if the remote server reported ECONNREFUSED, it must have been |
1283 | reachable because of the status packet that it reported. |
1284 | With this option enabled, the full three-way tcp handshake |
1285 | must have been established successfully before it will |
1286 | claim it is reachable. NOTE: It still does nothing more |
1287 | than connect and disconnect. It does not speak any protocol |
1288 | (i.e., HTTP or FTP) to ensure the remote server is sane in |
1289 | any way. The remote server CPU could be grinding to a halt |
1290 | and unresponsive to any clients connecting, but if the kernel |
1291 | throws the ACK packet, it is considered alive anyway. To |
1292 | really determine if the server is responding well would be |
1293 | application specific and is beyond the scope of Net::Ping. |
1294 | |
1295 | This only affects "tcp" and "syn" protocols. |
1296 | |
1297 | This is disabled by default. |
1298 | |
e82f584b |
1299 | =item $p->hires( { 0 | 1 } ); |
1300 | |
1301 | Causes this module to use Time::HiRes module, allowing milliseconds |
1302 | to be returned by subsequent calls to ping(). |
1303 | |
15d96390 |
1304 | This is disabled by default. |
1305 | |
49afa5f6 |
1306 | =item $p->bind($local_addr); |
1307 | |
1308 | Sets the source address from which pings will be sent. This must be |
1309 | the address of one of the interfaces on the local host. $local_addr |
1310 | may be specified as a hostname or as a text IP address such as |
1311 | "192.168.1.1". |
1312 | |
1313 | If the protocol is set to "tcp", this method may be called any |
1314 | number of times, and each call to the ping() method (below) will use |
1315 | the most recent $local_addr. If the protocol is "icmp" or "udp", |
1316 | then bind() must be called at most once per object, and (if it is |
1317 | called at all) must be called before the first call to ping() for that |
1318 | object. |
1319 | |
b124990b |
1320 | =item $p->open($host); |
1321 | |
f569508e |
1322 | When you are using the "stream" protocol, this call pre-opens the |
b124990b |
1323 | tcp socket. It's only necessary to do this if you want to |
1324 | provide a different timeout when creating the connection, or |
1325 | remove the overhead of establishing the connection from the |
1326 | first ping. If you don't call C<open()>, the connection is |
1327 | automatically opened the first time C<ping()> is called. |
787ecdfa |
1328 | This call simply does nothing if you are using any protocol other |
1329 | than stream. |
1330 | |
f569508e |
1331 | =item $p->ack( [ $host ] ); |
1332 | |
1333 | When using the "syn" protocol, use this method to determine |
1334 | the reachability of the remote host. This method is meant |
1335 | to be called up to as many times as ping() was called. Each |
1336 | call returns the host (as passed to ping()) that came back |
1337 | with the TCP ACK. The order in which the hosts are returned |
1338 | may not necessarily be the same order in which they were |
1339 | SYN queued using the ping() method. If the timeout is |
1340 | reached before the TCP ACK is received, or if the remote |
1341 | host is not listening on the port attempted, then the TCP |
1342 | connection will not be established and ack() will return |
1343 | undef. In list context, the host, the ack time, and the |
1344 | dotted ip string will be returned instead of just the host. |
1345 | If the optional $host argument is specified, the return |
1346 | value will be partaining to that host only. |
1347 | This call simply does nothing if you are using any protocol |
1348 | other than syn. |
1349 | |
1350 | =item $p->nack( $failed_ack_host ); |
1351 | |
1352 | The reason that host $failed_ack_host did not receive a |
1353 | valid ACK. Useful to find out why when ack( $fail_ack_host ) |
1354 | returns a false value. |
1355 | |
a3b93737 |
1356 | =item $p->close(); |
1357 | |
1358 | Close the network connection for this ping object. The network |
1359 | connection is also closed by "undef $p". The network connection is |
1360 | automatically closed if the ping object goes out of scope (e.g. $p is |
1361 | local to a subroutine and you leave the subroutine). |
1362 | |
1363 | =item pingecho($host [, $timeout]); |
1364 | |
1365 | To provide backward compatibility with the previous version of |
1366 | Net::Ping, a pingecho() subroutine is available with the same |
1367 | functionality as before. pingecho() uses the tcp protocol. The |
1368 | return values and parameters are the same as described for the ping() |
1369 | method. This subroutine is obsolete and may be removed in a future |
1370 | version of Net::Ping. |
8e07c86e |
1371 | |
a3b93737 |
1372 | =back |
8e07c86e |
1373 | |
b124990b |
1374 | =head1 WARNING |
1375 | |
1376 | pingecho() or a ping object with the tcp protocol use alarm() to |
1377 | implement the timeout. So, don't use alarm() in your program while |
1378 | you are using pingecho() or a ping object with the tcp protocol. The |
1379 | udp and icmp protocols do not use alarm() to implement the timeout. |
1380 | |
a3b93737 |
1381 | =head1 NOTES |
8e07c86e |
1382 | |
a3b93737 |
1383 | There will be less network overhead (and some efficiency in your |
1384 | program) if you specify either the udp or the icmp protocol. The tcp |
1385 | protocol will generate 2.5 times or more traffic for each ping than |
1386 | either udp or icmp. If many hosts are pinged frequently, you may wish |
1387 | to implement a small wait (e.g. 25ms or more) between each ping to |
1388 | avoid flooding your network with packets. |
8e07c86e |
1389 | |
a3b93737 |
1390 | The icmp protocol requires that the program be run as root or that it |
787ecdfa |
1391 | be setuid to root. The other protocols do not require special |
1392 | privileges, but not all network devices implement tcp or udp echo. |
8e07c86e |
1393 | |
a3b93737 |
1394 | Local hosts should normally respond to pings within milliseconds. |
1395 | However, on a very congested network it may take up to 3 seconds or |
1396 | longer to receive an echo packet from the remote host. If the timeout |
1397 | is set too low under these conditions, it will appear that the remote |
1398 | host is not reachable (which is almost the truth). |
8e07c86e |
1399 | |
a3b93737 |
1400 | Reachability doesn't necessarily mean that the remote host is actually |
787ecdfa |
1401 | functioning beyond its ability to echo packets. tcp is slightly better |
1402 | at indicating the health of a system than icmp because it uses more |
1403 | of the networking stack to respond. |
8e07c86e |
1404 | |
a3b93737 |
1405 | Because of a lack of anything better, this module uses its own |
1406 | routines to pack and unpack ICMP packets. It would be better for a |
1407 | separate module to be written which understands all of the different |
1408 | kinds of ICMP packets. |
8e07c86e |
1409 | |
5d20095f |
1410 | =head1 INSTALL |
1411 | |
1412 | The latest source tree is available via cvs: |
1413 | |
f569508e |
1414 | cvs -z3 -q -d :pserver:anonymous@cvs.roobik.com.:/usr/local/cvsroot/freeware checkout Net-Ping |
5d20095f |
1415 | cd Net-Ping |
1416 | |
1417 | The tarball can be created as follows: |
1418 | |
1419 | perl Makefile.PL ; make ; make dist |
1420 | |
1421 | The latest Net::Ping release can be found at CPAN: |
1422 | |
1423 | $CPAN/modules/by-module/Net/ |
1424 | |
1425 | 1) Extract the tarball |
1426 | |
1427 | gtar -zxvf Net-Ping-xxxx.tar.gz |
1428 | cd Net-Ping-xxxx |
1429 | |
1430 | 2) Build: |
1431 | |
1432 | make realclean |
1433 | perl Makefile.PL |
1434 | make |
1435 | make test |
1436 | |
1437 | 3) Install |
1438 | |
1439 | make install |
1440 | |
1441 | Or install it RPM Style: |
1442 | |
1443 | rpm -ta SOURCES/Net-Ping-xxxx.tar.gz |
1444 | |
1445 | rpm -ih RPMS/noarch/perl-Net-Ping-xxxx.rpm |
1446 | |
49afa5f6 |
1447 | =head1 AUTHORS |
b124990b |
1448 | |
e82f584b |
1449 | Current maintainer: |
49afa5f6 |
1450 | bbb@cpan.org (Rob Brown) |
b124990b |
1451 | |
e82f584b |
1452 | External protocol: |
1453 | colinm@cpan.org (Colin McMillen) |
1454 | |
b124990b |
1455 | Stream protocol: |
1456 | bronson@trestle.com (Scott Bronson) |
1457 | |
1458 | Original pingecho(): |
1459 | karrer@bernina.ethz.ch (Andreas Karrer) |
1460 | pmarquess@bfsec.bt.co.uk (Paul Marquess) |
1461 | |
1462 | Original Net::Ping author: |
1463 | mose@ns.ccsn.edu (Russell Mosemann) |
1464 | |
b124990b |
1465 | =head1 COPYRIGHT |
1466 | |
e82f584b |
1467 | Copyright (c) 2002, Rob Brown. All rights reserved. |
49afa5f6 |
1468 | |
e82f584b |
1469 | Copyright (c) 2001, Colin McMillen. All rights reserved. |
b124990b |
1470 | |
1471 | This program is free software; you may redistribute it and/or |
1472 | modify it under the same terms as Perl itself. |
1473 | |
a3b93737 |
1474 | =cut |