Commit | Line | Data |
a0d0e21e |
1 | package Net::Ping; |
2 | |
5d20095f |
3 | # $Id: Ping.pm,v 1.6 2002/06/19 15:23:48 rob Exp $ |
b124990b |
4 | |
5 | require 5.002; |
a0d0e21e |
6 | require Exporter; |
7 | |
a3b93737 |
8 | use strict; |
b124990b |
9 | use vars qw(@ISA @EXPORT $VERSION |
5d20095f |
10 | $def_timeout $def_proto $max_datasize $pingstring $hires $source_verify); |
a3b93737 |
11 | use FileHandle; |
12 | use Socket qw( SOCK_DGRAM SOCK_STREAM SOCK_RAW PF_INET |
e82f584b |
13 | inet_aton inet_ntoa sockaddr_in ); |
a3b93737 |
14 | use Carp; |
ef73e1db |
15 | use POSIX qw(ECONNREFUSED); |
a79c1648 |
16 | |
a0d0e21e |
17 | @ISA = qw(Exporter); |
a3b93737 |
18 | @EXPORT = qw(pingecho); |
5d20095f |
19 | $VERSION = "2.20"; |
a0d0e21e |
20 | |
a3b93737 |
21 | # Constants |
a0d0e21e |
22 | |
a3b93737 |
23 | $def_timeout = 5; # Default timeout to wait for a reply |
a5a165b1 |
24 | $def_proto = "tcp"; # Default protocol to use for pinging |
a3b93737 |
25 | $max_datasize = 1024; # Maximum data bytes in a packet |
b124990b |
26 | # The data we exchange with the server for the stream protocol |
27 | $pingstring = "pingschwingping!\n"; |
5d20095f |
28 | $source_verify = 1; # Default is to verify source endpoint |
a0d0e21e |
29 | |
ef73e1db |
30 | if ($^O =~ /Win32/i) { |
31 | # Hack to avoid this Win32 spewage: |
32 | # Your vendor has not defined POSIX macro ECONNREFUSED |
33 | *ECONNREFUSED = sub {10061;}; # "Unknown Error" Special Win32 Response? |
34 | }; |
35 | |
a3b93737 |
36 | # Description: The pingecho() subroutine is provided for backward |
37 | # compatibility with the original Net::Ping. It accepts a host |
38 | # name/IP and an optional timeout in seconds. Create a tcp ping |
39 | # object and try pinging the host. The result of the ping is returned. |
a0d0e21e |
40 | |
a3b93737 |
41 | sub pingecho |
42 | { |
e82f584b |
43 | my ($host, # Name or IP number of host to ping |
44 | $timeout # Optional timeout in seconds |
45 | ) = @_; |
46 | my ($p); # A ping object |
a0d0e21e |
47 | |
e82f584b |
48 | $p = Net::Ping->new("tcp", $timeout); |
49 | $p->ping($host); # Going out of scope closes the connection |
a3b93737 |
50 | } |
a0d0e21e |
51 | |
a3b93737 |
52 | # Description: The new() method creates a new ping object. Optional |
53 | # parameters may be specified for the protocol to use, the timeout in |
54 | # seconds and the size in bytes of additional data which should be |
55 | # included in the packet. |
56 | # After the optional parameters are checked, the data is constructed |
57 | # and a socket is opened if appropriate. The object is returned. |
58 | |
59 | sub new |
60 | { |
e82f584b |
61 | my ($this, |
62 | $proto, # Optional protocol to use for pinging |
63 | $timeout, # Optional timeout in seconds |
64 | $data_size # Optional additional bytes of data |
65 | ) = @_; |
66 | my $class = ref($this) || $this; |
67 | my $self = {}; |
68 | my ($cnt, # Count through data bytes |
69 | $min_datasize # Minimum data bytes required |
70 | ); |
71 | |
72 | bless($self, $class); |
73 | |
74 | $proto = $def_proto unless $proto; # Determine the protocol |
75 | croak('Protocol for ping must be "icmp", "udp", "tcp", "stream", or "external"') |
76 | unless $proto =~ m/^(icmp|udp|tcp|stream|external)$/; |
77 | $self->{"proto"} = $proto; |
78 | |
79 | $timeout = $def_timeout unless $timeout; # Determine the timeout |
80 | croak("Default timeout for ping must be greater than 0 seconds") |
81 | if $timeout <= 0; |
82 | $self->{"timeout"} = $timeout; |
83 | |
84 | $min_datasize = ($proto eq "udp") ? 1 : 0; # Determine data size |
85 | $data_size = $min_datasize unless defined($data_size) && $proto ne "tcp"; |
86 | croak("Data for ping must be from $min_datasize to $max_datasize bytes") |
87 | if ($data_size < $min_datasize) || ($data_size > $max_datasize); |
88 | $data_size-- if $self->{"proto"} eq "udp"; # We provide the first byte |
89 | $self->{"data_size"} = $data_size; |
90 | |
91 | $self->{"data"} = ""; # Construct data bytes |
92 | for ($cnt = 0; $cnt < $self->{"data_size"}; $cnt++) |
93 | { |
94 | $self->{"data"} .= chr($cnt % 256); |
95 | } |
96 | |
97 | $self->{"local_addr"} = undef; # Don't bind by default |
98 | |
99 | $self->{"seq"} = 0; # For counting packets |
100 | if ($self->{"proto"} eq "udp") # Open a socket |
101 | { |
102 | $self->{"proto_num"} = (getprotobyname('udp'))[2] || |
103 | croak("Can't udp protocol by name"); |
104 | $self->{"port_num"} = (getservbyname('echo', 'udp'))[2] || |
105 | croak("Can't get udp echo port by name"); |
106 | $self->{"fh"} = FileHandle->new(); |
107 | socket($self->{"fh"}, PF_INET, SOCK_DGRAM, |
108 | $self->{"proto_num"}) || |
109 | croak("udp socket error - $!"); |
110 | } |
111 | elsif ($self->{"proto"} eq "icmp") |
112 | { |
113 | croak("icmp ping requires root privilege") if ($> and $^O ne 'VMS'); |
114 | $self->{"proto_num"} = (getprotobyname('icmp'))[2] || |
115 | croak("Can't get icmp protocol by name"); |
116 | $self->{"pid"} = $$ & 0xffff; # Save lower 16 bits of pid |
117 | $self->{"fh"} = FileHandle->new(); |
118 | socket($self->{"fh"}, PF_INET, SOCK_RAW, $self->{"proto_num"}) || |
119 | croak("icmp socket error - $!"); |
120 | } |
121 | elsif ($self->{"proto"} eq "tcp" || $self->{"proto"} eq "stream") |
122 | { |
123 | $self->{"proto_num"} = (getprotobyname('tcp'))[2] || |
124 | croak("Can't get tcp protocol by name"); |
125 | $self->{"port_num"} = (getservbyname('echo', 'tcp'))[2] || |
126 | croak("Can't get tcp echo port by name"); |
127 | $self->{"fh"} = FileHandle->new(); |
128 | } |
129 | |
130 | return($self); |
a3b93737 |
131 | } |
a0d0e21e |
132 | |
49afa5f6 |
133 | # Description: Set the local IP address from which pings will be sent. |
134 | # For ICMP and UDP pings, this calls bind() on the already-opened socket; |
135 | # for TCP pings, just saves the address to be used when the socket is |
136 | # opened. Returns non-zero if successful; croaks on error. |
137 | sub bind |
138 | { |
e82f584b |
139 | my ($self, |
140 | $local_addr # Name or IP number of local interface |
141 | ) = @_; |
142 | my ($ip # Packed IP number of $local_addr |
143 | ); |
144 | |
145 | croak("Usage: \$p->bind(\$local_addr)") unless @_ == 2; |
146 | croak("already bound") if defined($self->{"local_addr"}) && |
147 | ($self->{"proto"} eq "udp" || $self->{"proto"} eq "icmp"); |
148 | |
149 | $ip = inet_aton($local_addr); |
150 | croak("nonexistent local address $local_addr") unless defined($ip); |
151 | $self->{"local_addr"} = $ip; # Only used if proto is tcp |
152 | |
153 | if ($self->{"proto"} eq "udp" || $self->{"proto"} eq "icmp") |
154 | { |
155 | CORE::bind($self->{"fh"}, sockaddr_in(0, $ip)) || |
156 | croak("$self->{'proto'} bind error - $!"); |
157 | } |
158 | elsif ($self->{"proto"} ne "tcp") |
159 | { |
160 | croak("Unknown protocol \"$self->{proto}\" in bind()"); |
161 | } |
162 | |
163 | return 1; |
164 | } |
49afa5f6 |
165 | |
49afa5f6 |
166 | |
15d96390 |
167 | # Description: Allow UDP source endpoint comparision to be |
168 | # skipped for those remote interfaces that do |
169 | # not response from the same endpoint. |
170 | |
171 | sub source_verify |
172 | { |
173 | my $self = shift; |
5d20095f |
174 | $source_verify = 1 unless defined |
175 | ($source_verify = ((defined $self) && (ref $self)) ? shift() : $self); |
15d96390 |
176 | } |
177 | |
e82f584b |
178 | # Description: allows the module to use milliseconds as returned by |
179 | # the Time::HiRes module |
49afa5f6 |
180 | |
e82f584b |
181 | $hires = 0; |
182 | sub hires |
183 | { |
184 | my $self = shift; |
185 | $hires = 1 unless defined |
186 | ($hires = ((defined $self) && (ref $self)) ? shift() : $self); |
187 | require Time::HiRes if $hires; |
49afa5f6 |
188 | } |
189 | |
e82f584b |
190 | sub time |
191 | { |
192 | return $hires ? Time::HiRes::time() : CORE::time(); |
193 | } |
49afa5f6 |
194 | |
a3b93737 |
195 | # Description: Ping a host name or IP number with an optional timeout. |
196 | # First lookup the host, and return undef if it is not found. Otherwise |
b124990b |
197 | # perform the specific ping method based on the protocol. Return the |
a3b93737 |
198 | # result of the ping. |
199 | |
200 | sub ping |
201 | { |
e82f584b |
202 | my ($self, |
203 | $host, # Name or IP number of host to ping |
204 | $timeout, # Seconds after which ping times out |
205 | ) = @_; |
206 | my ($ip, # Packed IP number of $host |
207 | $ret, # The return value |
208 | $ping_time, # When ping began |
209 | ); |
210 | |
211 | croak("Usage: \$p->ping(\$host [, \$timeout])") unless @_ == 2 || @_ == 3; |
212 | $timeout = $self->{"timeout"} unless $timeout; |
213 | croak("Timeout must be greater than 0 seconds") if $timeout <= 0; |
214 | |
215 | $ip = inet_aton($host); |
216 | return(undef) unless defined($ip); # Does host exist? |
217 | |
218 | # Dispatch to the appropriate routine. |
219 | $ping_time = &time(); |
220 | if ($self->{"proto"} eq "external") { |
221 | $ret = $self->ping_external($ip, $timeout); |
222 | } |
223 | elsif ($self->{"proto"} eq "udp") { |
224 | $ret = $self->ping_udp($ip, $timeout); |
225 | } |
226 | elsif ($self->{"proto"} eq "icmp") { |
227 | $ret = $self->ping_icmp($ip, $timeout); |
228 | } |
229 | elsif ($self->{"proto"} eq "tcp") { |
230 | $ret = $self->ping_tcp($ip, $timeout); |
231 | } |
232 | elsif ($self->{"proto"} eq "stream") { |
233 | $ret = $self->ping_stream($ip, $timeout); |
234 | } else { |
787ecdfa |
235 | croak("Unknown protocol \"$self->{proto}\" in ping()"); |
e82f584b |
236 | } |
237 | |
238 | return wantarray ? ($ret, &time() - $ping_time, inet_ntoa($ip)) : $ret; |
787ecdfa |
239 | } |
240 | |
241 | # Uses Net::Ping::External to do an external ping. |
242 | sub ping_external { |
243 | my ($self, |
244 | $ip, # Packed IP number of the host |
245 | $timeout # Seconds after which ping times out |
246 | ) = @_; |
247 | |
b124990b |
248 | eval { require Net::Ping::External; } |
249 | or croak('Protocol "external" not supported on your system: Net::Ping::External not found'); |
787ecdfa |
250 | return Net::Ping::External::ping(ip => $ip, timeout => $timeout); |
a3b93737 |
251 | } |
a0d0e21e |
252 | |
49afa5f6 |
253 | use constant ICMP_ECHOREPLY => 0; # ICMP packet types |
254 | use constant ICMP_ECHO => 8; |
255 | use constant ICMP_STRUCT => "C2 S3 A"; # Structure of a minimal ICMP packet |
256 | use constant SUBCODE => 0; # No ICMP subcode for ECHO and ECHOREPLY |
257 | use constant ICMP_FLAGS => 0; # No special flags for send or recv |
258 | use constant ICMP_PORT => 0; # No port with ICMP |
259 | |
a3b93737 |
260 | sub ping_icmp |
261 | { |
e82f584b |
262 | my ($self, |
263 | $ip, # Packed IP number of the host |
264 | $timeout # Seconds after which ping times out |
265 | ) = @_; |
266 | |
267 | my ($saddr, # sockaddr_in with port and ip |
268 | $checksum, # Checksum of ICMP packet |
269 | $msg, # ICMP packet to send |
270 | $len_msg, # Length of $msg |
271 | $rbits, # Read bits, filehandles for reading |
272 | $nfound, # Number of ready filehandles found |
273 | $finish_time, # Time ping should be finished |
274 | $done, # set to 1 when we are done |
275 | $ret, # Return value |
276 | $recv_msg, # Received message including IP header |
277 | $from_saddr, # sockaddr_in of sender |
278 | $from_port, # Port packet was sent from |
279 | $from_ip, # Packed IP of sender |
280 | $from_type, # ICMP type |
281 | $from_subcode, # ICMP subcode |
282 | $from_chk, # ICMP packet checksum |
283 | $from_pid, # ICMP packet id |
284 | $from_seq, # ICMP packet sequence |
285 | $from_msg # ICMP message |
286 | ); |
287 | |
288 | $self->{"seq"} = ($self->{"seq"} + 1) % 65536; # Increment sequence |
289 | $checksum = 0; # No checksum for starters |
290 | $msg = pack(ICMP_STRUCT . $self->{"data_size"}, ICMP_ECHO, SUBCODE, |
291 | $checksum, $self->{"pid"}, $self->{"seq"}, $self->{"data"}); |
292 | $checksum = Net::Ping->checksum($msg); |
293 | $msg = pack(ICMP_STRUCT . $self->{"data_size"}, ICMP_ECHO, SUBCODE, |
294 | $checksum, $self->{"pid"}, $self->{"seq"}, $self->{"data"}); |
295 | $len_msg = length($msg); |
296 | $saddr = sockaddr_in(ICMP_PORT, $ip); |
297 | send($self->{"fh"}, $msg, ICMP_FLAGS, $saddr); # Send the message |
298 | |
299 | $rbits = ""; |
300 | vec($rbits, $self->{"fh"}->fileno(), 1) = 1; |
301 | $ret = 0; |
302 | $done = 0; |
303 | $finish_time = &time() + $timeout; # Must be done by this time |
304 | while (!$done && $timeout > 0) # Keep trying if we have time |
305 | { |
306 | $nfound = select($rbits, undef, undef, $timeout); # Wait for packet |
307 | $timeout = $finish_time - &time(); # Get remaining time |
308 | if (!defined($nfound)) # Hmm, a strange error |
a3b93737 |
309 | { |
e82f584b |
310 | $ret = undef; |
311 | $done = 1; |
312 | } |
313 | elsif ($nfound) # Got a packet from somewhere |
314 | { |
315 | $recv_msg = ""; |
316 | $from_saddr = recv($self->{"fh"}, $recv_msg, 1500, ICMP_FLAGS); |
317 | ($from_port, $from_ip) = sockaddr_in($from_saddr); |
318 | ($from_type, $from_subcode, $from_chk, |
319 | $from_pid, $from_seq, $from_msg) = |
320 | unpack(ICMP_STRUCT . $self->{"data_size"}, |
321 | substr($recv_msg, length($recv_msg) - $len_msg, |
322 | $len_msg)); |
323 | if (($from_type == ICMP_ECHOREPLY) && |
5d20095f |
324 | (!$source_verify || $from_ip eq $ip) && |
e82f584b |
325 | ($from_pid == $self->{"pid"}) && # Does the packet check out? |
326 | ($from_seq == $self->{"seq"})) |
327 | { |
328 | $ret = 1; # It's a winner |
329 | $done = 1; |
330 | } |
a3b93737 |
331 | } |
e82f584b |
332 | else # Oops, timed out |
333 | { |
334 | $done = 1; |
335 | } |
336 | } |
337 | return $ret; |
a3b93737 |
338 | } |
339 | |
340 | # Description: Do a checksum on the message. Basically sum all of |
341 | # the short words and fold the high order bits into the low order bits. |
342 | |
343 | sub checksum |
344 | { |
e82f584b |
345 | my ($class, |
346 | $msg # The message to checksum |
347 | ) = @_; |
348 | my ($len_msg, # Length of the message |
349 | $num_short, # The number of short words in the message |
350 | $short, # One short word |
351 | $chk # The checksum |
352 | ); |
353 | |
354 | $len_msg = length($msg); |
355 | $num_short = int($len_msg / 2); |
356 | $chk = 0; |
357 | foreach $short (unpack("S$num_short", $msg)) |
358 | { |
359 | $chk += $short; |
360 | } # Add the odd byte in |
361 | $chk += (unpack("C", substr($msg, $len_msg - 1, 1)) << 8) if $len_msg % 2; |
362 | $chk = ($chk >> 16) + ($chk & 0xffff); # Fold high into low |
363 | return(~(($chk >> 16) + $chk) & 0xffff); # Again and complement |
a3b93737 |
364 | } |
365 | |
787ecdfa |
366 | |
b124990b |
367 | # Description: Perform a tcp echo ping. Since a tcp connection is |
368 | # host specific, we have to open and close each connection here. We |
369 | # can't just leave a socket open. Because of the robust nature of |
370 | # tcp, it will take a while before it gives up trying to establish a |
371 | # connection. Therefore, we use select() on a non-blocking socket to |
372 | # check against our timeout. No data bytes are actually |
373 | # sent since the successful establishment of a connection is proof |
374 | # enough of the reachability of the remote host. Also, tcp is |
375 | # expensive and doesn't need our help to add to the overhead. |
376 | |
377 | sub ping_tcp |
787ecdfa |
378 | { |
e82f584b |
379 | my ($self, |
380 | $ip, # Packed IP number of the host |
381 | $timeout # Seconds after which ping times out |
382 | ) = @_; |
383 | my ($ret # The return value |
384 | ); |
385 | |
386 | $@ = ""; $! = 0; |
387 | $ret = $self -> tcp_connect( $ip, $timeout); |
ef73e1db |
388 | $ret = 1 if $! == ECONNREFUSED; # Connection refused |
e82f584b |
389 | $self->{"fh"}->close(); |
390 | return $ret; |
787ecdfa |
391 | } |
392 | |
b124990b |
393 | sub tcp_connect |
787ecdfa |
394 | { |
e82f584b |
395 | my ($self, |
396 | $ip, # Packed IP number of the host |
397 | $timeout # Seconds after which connect times out |
398 | ) = @_; |
399 | my ($saddr); # Packed IP and Port |
b124990b |
400 | |
e82f584b |
401 | $saddr = sockaddr_in($self->{"port_num"}, $ip); |
b124990b |
402 | |
e82f584b |
403 | my $ret = 0; # Default to unreachable |
b124990b |
404 | |
e82f584b |
405 | my $do_socket = sub { |
406 | socket($self->{"fh"}, PF_INET, SOCK_STREAM, $self->{"proto_num"}) || |
407 | croak("tcp socket error - $!"); |
408 | if (defined $self->{"local_addr"} && |
409 | !CORE::bind($self->{"fh"}, sockaddr_in(0, $self->{"local_addr"}))) { |
410 | croak("tcp bind error - $!"); |
411 | } |
412 | }; |
413 | my $do_connect = sub { |
414 | eval { |
415 | die $! unless connect($self->{"fh"}, $saddr); |
416 | $self->{"ip"} = $ip; |
417 | $ret = 1; |
418 | }; |
419 | $ret; |
420 | }; |
421 | |
422 | if ($^O =~ /Win32/i) { |
423 | |
424 | # Buggy Winsock API doesn't allow us to use alarm() calls. |
425 | # Hence, if our OS is Windows, we need to create a separate |
426 | # process to do the blocking connect attempt. |
427 | |
428 | $| = 1; # Clear buffer prior to fork to prevent duplicate flushing. |
429 | my $pid = fork; |
430 | if (!$pid) { |
431 | if (!defined $pid) { |
432 | # Fork did not work |
433 | warn "Win32 Fork error: $!"; |
434 | return 0; |
b124990b |
435 | } |
b124990b |
436 | &{ $do_socket }(); |
437 | |
e82f584b |
438 | # Try a slow blocking connect() call |
439 | # and report the status to the pipe. |
440 | if ( &{ $do_connect }() ) { |
441 | $self->{"fh"}->close(); |
442 | # No error |
443 | exit 0; |
b124990b |
444 | } else { |
e82f584b |
445 | # Pass the error status to the parent |
446 | exit $!; |
b124990b |
447 | } |
e82f584b |
448 | } |
b124990b |
449 | |
e82f584b |
450 | &{ $do_socket }(); |
451 | |
452 | my $patience = &time() + $timeout; |
453 | |
454 | require POSIX; |
455 | my ($child); |
456 | $? = 0; |
457 | # Wait up to the timeout |
458 | # And clean off the zombie |
459 | do { |
460 | $child = waitpid($pid, &POSIX::WNOHANG); |
461 | $! = $? >> 8; |
462 | $@ = $!; |
463 | select(undef, undef, undef, 0.1); |
464 | } while &time() < $patience && $child != $pid; |
465 | |
466 | if ($child == $pid) { |
467 | # Since she finished within the timeout, |
468 | # it is probably safe for me to try it too |
b124990b |
469 | &{ $do_connect }(); |
e82f584b |
470 | } else { |
471 | # Time must have run out. |
472 | $@ = "Timed out!"; |
473 | # Put that choking client out of its misery |
474 | kill "KILL", $pid; |
475 | # Clean off the zombie |
476 | waitpid($pid, 0); |
477 | $ret = 0; |
b124990b |
478 | } |
e82f584b |
479 | } else { # Win32 |
480 | # Otherwise don't waste the resources to fork |
481 | |
482 | &{ $do_socket }(); |
483 | |
484 | $SIG{'ALRM'} = sub { die "Timed out!"; }; |
485 | alarm($timeout); # Interrupt connect() if we have to |
486 | |
487 | &{ $do_connect }(); |
488 | alarm(0); |
489 | } |
787ecdfa |
490 | |
e82f584b |
491 | return $ret; |
787ecdfa |
492 | } |
493 | |
494 | # This writes the given string to the socket and then reads it |
495 | # back. It returns 1 on success, 0 on failure. |
496 | sub tcp_echo |
497 | { |
e82f584b |
498 | my $self = shift; |
499 | my $timeout = shift; |
500 | my $pingstring = shift; |
501 | |
502 | my $ret = undef; |
503 | my $time = &time(); |
504 | my $wrstr = $pingstring; |
505 | my $rdstr = ""; |
506 | |
507 | eval <<'EOM'; |
508 | do { |
509 | my $rin = ""; |
510 | vec($rin, $self->{"fh"}->fileno(), 1) = 1; |
511 | |
512 | my $rout = undef; |
513 | if($wrstr) { |
514 | $rout = ""; |
515 | vec($rout, $self->{"fh"}->fileno(), 1) = 1; |
516 | } |
517 | |
518 | if(select($rin, $rout, undef, ($time + $timeout) - &time())) { |
519 | |
520 | if($rout && vec($rout,$self->{"fh"}->fileno(),1)) { |
521 | my $num = syswrite($self->{"fh"}, $wrstr); |
522 | if($num) { |
523 | # If it was a partial write, update and try again. |
524 | $wrstr = substr($wrstr,$num); |
525 | } else { |
526 | # There was an error. |
527 | $ret = 0; |
528 | } |
529 | } |
530 | |
531 | if(vec($rin,$self->{"fh"}->fileno(),1)) { |
532 | my $reply; |
533 | if(sysread($self->{"fh"},$reply,length($pingstring)-length($rdstr))) { |
534 | $rdstr .= $reply; |
535 | $ret = 1 if $rdstr eq $pingstring; |
536 | } else { |
537 | # There was an error. |
538 | $ret = 0; |
539 | } |
540 | } |
541 | |
542 | } |
543 | } until &time() > ($time + $timeout) || defined($ret); |
787ecdfa |
544 | EOM |
545 | |
e82f584b |
546 | return $ret; |
787ecdfa |
547 | } |
548 | |
787ecdfa |
549 | |
787ecdfa |
550 | |
787ecdfa |
551 | |
552 | # Description: Perform a stream ping. If the tcp connection isn't |
553 | # already open, it opens it. It then sends some data and waits for |
554 | # a reply. It leaves the stream open on exit. |
555 | |
556 | sub ping_stream |
557 | { |
e82f584b |
558 | my ($self, |
559 | $ip, # Packed IP number of the host |
560 | $timeout # Seconds after which ping times out |
561 | ) = @_; |
072620d9 |
562 | |
e82f584b |
563 | # Open the stream if it's not already open |
564 | if(!defined $self->{"fh"}->fileno()) { |
565 | $self->tcp_connect($ip, $timeout) or return 0; |
566 | } |
787ecdfa |
567 | |
e82f584b |
568 | croak "tried to switch servers while stream pinging" |
569 | if $self->{"ip"} ne $ip; |
570 | |
571 | return $self->tcp_echo($timeout, $pingstring); |
787ecdfa |
572 | } |
573 | |
574 | # Description: opens the stream. You would do this if you want to |
575 | # separate the overhead of opening the stream from the first ping. |
576 | |
577 | sub open |
578 | { |
e82f584b |
579 | my ($self, |
580 | $host, # Host or IP address |
581 | $timeout # Seconds after which open times out |
582 | ) = @_; |
583 | |
584 | my ($ip); # Packed IP number of the host |
585 | $ip = inet_aton($host); |
586 | $timeout = $self->{"timeout"} unless $timeout; |
587 | |
588 | if($self->{"proto"} eq "stream") { |
589 | if(defined($self->{"fh"}->fileno())) { |
590 | croak("socket is already open"); |
591 | } else { |
592 | $self->tcp_connect($ip, $timeout); |
b124990b |
593 | } |
e82f584b |
594 | } |
072620d9 |
595 | } |
596 | |
b124990b |
597 | |
a3b93737 |
598 | # Description: Perform a udp echo ping. Construct a message of |
599 | # at least the one-byte sequence number and any additional data bytes. |
600 | # Send the message out and wait for a message to come back. If we |
601 | # get a message, make sure all of its parts match. If they do, we are |
602 | # done. Otherwise go back and wait for the message until we run out |
603 | # of time. Return the result of our efforts. |
604 | |
49afa5f6 |
605 | use constant UDP_FLAGS => 0; # Nothing special on send or recv |
606 | |
a3b93737 |
607 | sub ping_udp |
608 | { |
e82f584b |
609 | my ($self, |
610 | $ip, # Packed IP number of the host |
611 | $timeout # Seconds after which ping times out |
612 | ) = @_; |
613 | |
614 | my ($saddr, # sockaddr_in with port and ip |
615 | $ret, # The return value |
616 | $msg, # Message to be echoed |
617 | $finish_time, # Time ping should be finished |
e82f584b |
618 | $done, # Set to 1 when we are done pinging |
619 | $rbits, # Read bits, filehandles for reading |
620 | $nfound, # Number of ready filehandles found |
621 | $from_saddr, # sockaddr_in of sender |
622 | $from_msg, # Characters echoed by $host |
623 | $from_port, # Port message was echoed from |
624 | $from_ip # Packed IP number of sender |
625 | ); |
626 | |
627 | $saddr = sockaddr_in($self->{"port_num"}, $ip); |
628 | $self->{"seq"} = ($self->{"seq"} + 1) % 256; # Increment sequence |
629 | $msg = chr($self->{"seq"}) . $self->{"data"}; # Add data if any |
630 | send($self->{"fh"}, $msg, UDP_FLAGS, $saddr); # Send it |
631 | |
632 | $rbits = ""; |
633 | vec($rbits, $self->{"fh"}->fileno(), 1) = 1; |
634 | $ret = 0; # Default to unreachable |
635 | $done = 0; |
e82f584b |
636 | $finish_time = &time() + $timeout; # Ping needs to be done by then |
637 | while (!$done && $timeout > 0) |
638 | { |
639 | $nfound = select($rbits, undef, undef, $timeout); # Wait for response |
640 | $timeout = $finish_time - &time(); # Get remaining time |
641 | |
642 | if (!defined($nfound)) # Hmm, a strange error |
a3b93737 |
643 | { |
e82f584b |
644 | $ret = undef; |
645 | $done = 1; |
a3b93737 |
646 | } |
e82f584b |
647 | elsif ($nfound) # A packet is waiting |
648 | { |
649 | $from_msg = ""; |
650 | $from_saddr = recv($self->{"fh"}, $from_msg, 1500, UDP_FLAGS) |
651 | or last; # For example an unreachable host will make recv() fail. |
652 | ($from_port, $from_ip) = sockaddr_in($from_saddr); |
5d20095f |
653 | if (!$source_verify || |
15d96390 |
654 | (($from_ip eq $ip) && # Does the packet check out? |
655 | ($from_port == $self->{"port_num"}) && |
656 | ($from_msg eq $msg))) |
e82f584b |
657 | { |
658 | $ret = 1; # It's a winner |
659 | $done = 1; |
660 | } |
661 | } |
662 | else # Oops, timed out |
663 | { |
664 | $done = 1; |
665 | } |
666 | } |
a5a165b1 |
667 | return $ret; |
b124990b |
668 | } |
a0d0e21e |
669 | |
a3b93737 |
670 | # Description: Close the connection unless we are using the tcp |
671 | # protocol, since it will already be closed. |
672 | |
673 | sub close |
674 | { |
e82f584b |
675 | my ($self) = @_; |
a3b93737 |
676 | |
e82f584b |
677 | $self->{"fh"}->close() unless $self->{"proto"} eq "tcp"; |
a3b93737 |
678 | } |
679 | |
680 | |
a0d0e21e |
681 | 1; |
8e07c86e |
682 | __END__ |
683 | |
8e07c86e |
684 | =head1 NAME |
685 | |
a3b93737 |
686 | Net::Ping - check a remote host for reachability |
8e07c86e |
687 | |
5d20095f |
688 | $Id: Ping.pm,v 1.6 2002/06/19 15:23:48 rob Exp $ |
b124990b |
689 | |
8e07c86e |
690 | =head1 SYNOPSIS |
691 | |
692 | use Net::Ping; |
8e07c86e |
693 | |
a3b93737 |
694 | $p = Net::Ping->new(); |
695 | print "$host is alive.\n" if $p->ping($host); |
696 | $p->close(); |
697 | |
698 | $p = Net::Ping->new("icmp"); |
49afa5f6 |
699 | $p->bind($my_addr); # Specify source interface of pings |
a3b93737 |
700 | foreach $host (@host_array) |
701 | { |
702 | print "$host is "; |
703 | print "NOT " unless $p->ping($host, 2); |
704 | print "reachable.\n"; |
705 | sleep(1); |
706 | } |
707 | $p->close(); |
b124990b |
708 | |
a3b93737 |
709 | $p = Net::Ping->new("tcp", 2); |
b124990b |
710 | # Try connecting to the www port instead of the echo port |
711 | $p->{port_num} = getservbyname("http", "tcp"); |
a3b93737 |
712 | while ($stop_time > time()) |
713 | { |
714 | print "$host not reachable ", scalar(localtime()), "\n" |
715 | unless $p->ping($host); |
716 | sleep(300); |
717 | } |
718 | undef($p); |
b124990b |
719 | |
e82f584b |
720 | # High precision syntax (requires Time::HiRes) |
721 | $p = Net::Ping->new(); |
722 | $p->hires(); |
723 | ($ret, $duration, $ip) = $p->ping($host, 5.5); |
724 | printf("$host [ip: $ip] is alive (packet return time: %.2f ms)\n", 1000 * $duration) |
725 | if $ret; |
726 | $p->close(); |
727 | |
a3b93737 |
728 | # For backward compatibility |
729 | print "$host is alive.\n" if pingecho($host); |
8e07c86e |
730 | |
a3b93737 |
731 | =head1 DESCRIPTION |
8e07c86e |
732 | |
a3b93737 |
733 | This module contains methods to test the reachability of remote |
734 | hosts on a network. A ping object is first created with optional |
735 | parameters, a variable number of hosts may be pinged multiple |
736 | times and then the connection is closed. |
737 | |
b124990b |
738 | You may choose one of four different protocols to use for the |
739 | ping. The "udp" protocol is the default. Note that a live remote host |
740 | may still fail to be pingable by one or more of these protocols. For |
741 | example, www.microsoft.com is generally alive but not pingable. |
787ecdfa |
742 | |
b124990b |
743 | With the "tcp" protocol the ping() method attempts to establish a |
744 | connection to the remote host's echo port. If the connection is |
745 | successfully established, the remote host is considered reachable. No |
746 | data is actually echoed. This protocol does not require any special |
747 | privileges but has higher overhead than the other two protocols. |
072620d9 |
748 | |
b124990b |
749 | Specifying the "udp" protocol causes the ping() method to send a udp |
a3b93737 |
750 | packet to the remote host's echo port. If the echoed packet is |
751 | received from the remote host and the received packet contains the |
752 | same data as the packet that was sent, the remote host is considered |
753 | reachable. This protocol does not require any special privileges. |
b124990b |
754 | It should be borne in mind that, for a udp ping, a host |
787ecdfa |
755 | will be reported as unreachable if it is not running the |
b124990b |
756 | appropriate echo service. For Unix-like systems see L<inetd(8)> |
757 | for more information. |
787ecdfa |
758 | |
b124990b |
759 | If the "icmp" protocol is specified, the ping() method sends an icmp |
760 | echo message to the remote host, which is what the UNIX ping program |
761 | does. If the echoed message is received from the remote host and |
762 | the echoed information is correct, the remote host is considered |
763 | reachable. Specifying the "icmp" protocol requires that the program |
764 | be run as root or that the program be setuid to root. |
787ecdfa |
765 | |
b124990b |
766 | If the "external" protocol is specified, the ping() method attempts to |
767 | use the C<Net::Ping::External> module to ping the remote host. |
768 | C<Net::Ping::External> interfaces with your system's default C<ping> |
769 | utility to perform the ping, and generally produces relatively |
787ecdfa |
770 | accurate results. If C<Net::Ping::External> if not installed on your |
771 | system, specifying the "external" protocol will result in an error. |
edc5bd88 |
772 | |
a3b93737 |
773 | =head2 Functions |
774 | |
775 | =over 4 |
776 | |
777 | =item Net::Ping->new([$proto [, $def_timeout [, $bytes]]]); |
778 | |
779 | Create a new ping object. All of the parameters are optional. $proto |
780 | specifies the protocol to use when doing a ping. The current choices |
781 | are "tcp", "udp" or "icmp". The default is "udp". |
782 | |
783 | If a default timeout ($def_timeout) in seconds is provided, it is used |
784 | when a timeout is not given to the ping() method (below). The timeout |
785 | must be greater than 0 and the default, if not specified, is 5 seconds. |
786 | |
787 | If the number of data bytes ($bytes) is given, that many data bytes |
788 | are included in the ping packet sent to the remote host. The number of |
789 | data bytes is ignored if the protocol is "tcp". The minimum (and |
790 | default) number of data bytes is 1 if the protocol is "udp" and 0 |
791 | otherwise. The maximum number of data bytes that can be specified is |
792 | 1024. |
793 | |
5d20095f |
794 | =item $p->ping($host [, $timeout]); |
795 | |
796 | Ping the remote host and wait for a response. $host can be either the |
797 | hostname or the IP number of the remote host. The optional timeout |
798 | must be greater than 0 seconds and defaults to whatever was specified |
799 | when the ping object was created. Returns a success flag. If the |
800 | hostname cannot be found or there is a problem with the IP number, the |
801 | success flag returned will be undef. Otherwise, the success flag will |
802 | be 1 if the host is reachable and 0 if it is not. For most practical |
803 | purposes, undef and 0 and can be treated as the same case. In array |
804 | context, the elapsed time is also returned. The elapsed time value will |
805 | be a float, as retuned by the Time::HiRes::time() function, if hires() |
806 | has been previously called, otherwise it is returned as an integer. |
807 | |
15d96390 |
808 | =item $p->source_verify( { 0 | 1 } ); |
809 | |
810 | Allows source endpoint verification to be enabled or disabled. |
811 | This is useful for those remote destinations with multiples |
812 | interfaces where the response may not originate from the same |
813 | endpoint that the original destination endpoint was sent to. |
5d20095f |
814 | This only affects udp and icmp protocol pings. |
15d96390 |
815 | |
816 | This is enabled by default. |
817 | |
e82f584b |
818 | =item $p->hires( { 0 | 1 } ); |
819 | |
820 | Causes this module to use Time::HiRes module, allowing milliseconds |
821 | to be returned by subsequent calls to ping(). |
822 | |
15d96390 |
823 | This is disabled by default. |
824 | |
49afa5f6 |
825 | =item $p->bind($local_addr); |
826 | |
827 | Sets the source address from which pings will be sent. This must be |
828 | the address of one of the interfaces on the local host. $local_addr |
829 | may be specified as a hostname or as a text IP address such as |
830 | "192.168.1.1". |
831 | |
832 | If the protocol is set to "tcp", this method may be called any |
833 | number of times, and each call to the ping() method (below) will use |
834 | the most recent $local_addr. If the protocol is "icmp" or "udp", |
835 | then bind() must be called at most once per object, and (if it is |
836 | called at all) must be called before the first call to ping() for that |
837 | object. |
838 | |
b124990b |
839 | =item $p->open($host); |
840 | |
841 | When you are using the stream protocol, this call pre-opens the |
842 | tcp socket. It's only necessary to do this if you want to |
843 | provide a different timeout when creating the connection, or |
844 | remove the overhead of establishing the connection from the |
845 | first ping. If you don't call C<open()>, the connection is |
846 | automatically opened the first time C<ping()> is called. |
787ecdfa |
847 | This call simply does nothing if you are using any protocol other |
848 | than stream. |
849 | |
a3b93737 |
850 | =item $p->close(); |
851 | |
852 | Close the network connection for this ping object. The network |
853 | connection is also closed by "undef $p". The network connection is |
854 | automatically closed if the ping object goes out of scope (e.g. $p is |
855 | local to a subroutine and you leave the subroutine). |
856 | |
857 | =item pingecho($host [, $timeout]); |
858 | |
859 | To provide backward compatibility with the previous version of |
860 | Net::Ping, a pingecho() subroutine is available with the same |
861 | functionality as before. pingecho() uses the tcp protocol. The |
862 | return values and parameters are the same as described for the ping() |
863 | method. This subroutine is obsolete and may be removed in a future |
864 | version of Net::Ping. |
8e07c86e |
865 | |
a3b93737 |
866 | =back |
8e07c86e |
867 | |
b124990b |
868 | =head1 WARNING |
869 | |
870 | pingecho() or a ping object with the tcp protocol use alarm() to |
871 | implement the timeout. So, don't use alarm() in your program while |
872 | you are using pingecho() or a ping object with the tcp protocol. The |
873 | udp and icmp protocols do not use alarm() to implement the timeout. |
874 | |
a3b93737 |
875 | =head1 NOTES |
8e07c86e |
876 | |
a3b93737 |
877 | There will be less network overhead (and some efficiency in your |
878 | program) if you specify either the udp or the icmp protocol. The tcp |
879 | protocol will generate 2.5 times or more traffic for each ping than |
880 | either udp or icmp. If many hosts are pinged frequently, you may wish |
881 | to implement a small wait (e.g. 25ms or more) between each ping to |
882 | avoid flooding your network with packets. |
8e07c86e |
883 | |
a3b93737 |
884 | The icmp protocol requires that the program be run as root or that it |
787ecdfa |
885 | be setuid to root. The other protocols do not require special |
886 | privileges, but not all network devices implement tcp or udp echo. |
8e07c86e |
887 | |
a3b93737 |
888 | Local hosts should normally respond to pings within milliseconds. |
889 | However, on a very congested network it may take up to 3 seconds or |
890 | longer to receive an echo packet from the remote host. If the timeout |
891 | is set too low under these conditions, it will appear that the remote |
892 | host is not reachable (which is almost the truth). |
8e07c86e |
893 | |
a3b93737 |
894 | Reachability doesn't necessarily mean that the remote host is actually |
787ecdfa |
895 | functioning beyond its ability to echo packets. tcp is slightly better |
896 | at indicating the health of a system than icmp because it uses more |
897 | of the networking stack to respond. |
8e07c86e |
898 | |
a3b93737 |
899 | Because of a lack of anything better, this module uses its own |
900 | routines to pack and unpack ICMP packets. It would be better for a |
901 | separate module to be written which understands all of the different |
902 | kinds of ICMP packets. |
8e07c86e |
903 | |
5d20095f |
904 | =head1 INSTALL |
905 | |
906 | The latest source tree is available via cvs: |
907 | |
908 | cvs -z3 -q -d :pserver:anonymous@cvs.roobik.com.:/usr/local/cvsroot/freeware co Net-Ping |
909 | cd Net-Ping |
910 | |
911 | The tarball can be created as follows: |
912 | |
913 | perl Makefile.PL ; make ; make dist |
914 | |
915 | The latest Net::Ping release can be found at CPAN: |
916 | |
917 | $CPAN/modules/by-module/Net/ |
918 | |
919 | 1) Extract the tarball |
920 | |
921 | gtar -zxvf Net-Ping-xxxx.tar.gz |
922 | cd Net-Ping-xxxx |
923 | |
924 | 2) Build: |
925 | |
926 | make realclean |
927 | perl Makefile.PL |
928 | make |
929 | make test |
930 | |
931 | 3) Install |
932 | |
933 | make install |
934 | |
935 | Or install it RPM Style: |
936 | |
937 | rpm -ta SOURCES/Net-Ping-xxxx.tar.gz |
938 | |
939 | rpm -ih RPMS/noarch/perl-Net-Ping-xxxx.rpm |
940 | |
49afa5f6 |
941 | =head1 AUTHORS |
b124990b |
942 | |
e82f584b |
943 | Current maintainer: |
49afa5f6 |
944 | bbb@cpan.org (Rob Brown) |
b124990b |
945 | |
e82f584b |
946 | External protocol: |
947 | colinm@cpan.org (Colin McMillen) |
948 | |
b124990b |
949 | Stream protocol: |
950 | bronson@trestle.com (Scott Bronson) |
951 | |
952 | Original pingecho(): |
953 | karrer@bernina.ethz.ch (Andreas Karrer) |
954 | pmarquess@bfsec.bt.co.uk (Paul Marquess) |
955 | |
956 | Original Net::Ping author: |
957 | mose@ns.ccsn.edu (Russell Mosemann) |
958 | |
b124990b |
959 | =head1 COPYRIGHT |
960 | |
e82f584b |
961 | Copyright (c) 2002, Rob Brown. All rights reserved. |
49afa5f6 |
962 | |
e82f584b |
963 | Copyright (c) 2001, Colin McMillen. All rights reserved. |
b124990b |
964 | |
965 | This program is free software; you may redistribute it and/or |
966 | modify it under the same terms as Perl itself. |
967 | |
a3b93737 |
968 | =cut |