Commit | Line | Data |
a0d0e21e |
1 | package Net::Ping; |
2 | |
b124990b |
3 | require 5.002; |
a0d0e21e |
4 | require Exporter; |
5 | |
a3b93737 |
6 | use strict; |
b124990b |
7 | use vars qw(@ISA @EXPORT $VERSION |
9539e94f |
8 | $def_timeout $def_proto $def_factor |
9 | $max_datasize $pingstring $hires $source_verify $syn_forking); |
f569508e |
10 | use Fcntl qw( F_GETFL F_SETFL O_NONBLOCK ); |
eb194dd9 |
11 | use Socket qw( SOCK_DGRAM SOCK_STREAM SOCK_RAW PF_INET SOL_SOCKET SO_ERROR |
e82f584b |
12 | inet_aton inet_ntoa sockaddr_in ); |
eb194dd9 |
13 | use POSIX qw( ENOTCONN ECONNREFUSED ECONNRESET EINPROGRESS EWOULDBLOCK EAGAIN WNOHANG ); |
f569508e |
14 | use FileHandle; |
a3b93737 |
15 | use Carp; |
a79c1648 |
16 | |
a0d0e21e |
17 | @ISA = qw(Exporter); |
a3b93737 |
18 | @EXPORT = qw(pingecho); |
9539e94f |
19 | $VERSION = "2.30"; |
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 |
9539e94f |
25 | $def_factor = 1.2; # Default exponential backoff rate. |
a3b93737 |
26 | $max_datasize = 1024; # Maximum data bytes in a packet |
b124990b |
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 | $syn_forking = 0; |
a0d0e21e |
31 | |
ef73e1db |
32 | if ($^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? |
eb194dd9 |
36 | *ENOTCONN = sub {10057;}; |
37 | *ECONNRESET = sub {10054;}; |
38 | *EINPROGRESS = sub {10036;}; |
39 | *EWOULDBLOCK = sub {10035;}; |
40 | # $syn_forking = 1; # XXX possibly useful in < Win2K ? |
ef73e1db |
41 | }; |
42 | |
f569508e |
43 | # h2ph "asm/socket.h" |
44 | # require "asm/socket.ph"; |
45 | sub SO_BINDTODEVICE {25;} |
46 | |
a3b93737 |
47 | # Description: The pingecho() subroutine is provided for backward |
48 | # compatibility with the original Net::Ping. It accepts a host |
49 | # name/IP and an optional timeout in seconds. Create a tcp ping |
50 | # object and try pinging the host. The result of the ping is returned. |
a0d0e21e |
51 | |
a3b93737 |
52 | sub pingecho |
53 | { |
e82f584b |
54 | my ($host, # Name or IP number of host to ping |
55 | $timeout # Optional timeout in seconds |
56 | ) = @_; |
57 | my ($p); # A ping object |
a0d0e21e |
58 | |
e82f584b |
59 | $p = Net::Ping->new("tcp", $timeout); |
60 | $p->ping($host); # Going out of scope closes the connection |
a3b93737 |
61 | } |
a0d0e21e |
62 | |
a3b93737 |
63 | # Description: The new() method creates a new ping object. Optional |
64 | # parameters may be specified for the protocol to use, the timeout in |
65 | # seconds and the size in bytes of additional data which should be |
66 | # included in the packet. |
67 | # After the optional parameters are checked, the data is constructed |
68 | # and a socket is opened if appropriate. The object is returned. |
69 | |
70 | sub new |
71 | { |
e82f584b |
72 | my ($this, |
73 | $proto, # Optional protocol to use for pinging |
74 | $timeout, # Optional timeout in seconds |
f569508e |
75 | $data_size, # Optional additional bytes of data |
76 | $device, # Optional device to use |
e82f584b |
77 | ) = @_; |
78 | my $class = ref($this) || $this; |
79 | my $self = {}; |
80 | my ($cnt, # Count through data bytes |
81 | $min_datasize # Minimum data bytes required |
82 | ); |
83 | |
84 | bless($self, $class); |
85 | |
86 | $proto = $def_proto unless $proto; # Determine the protocol |
f569508e |
87 | croak('Protocol for ping must be "icmp", "udp", "tcp", "syn", "stream", or "external"') |
88 | unless $proto =~ m/^(icmp|udp|tcp|syn|stream|external)$/; |
e82f584b |
89 | $self->{"proto"} = $proto; |
90 | |
91 | $timeout = $def_timeout unless $timeout; # Determine the timeout |
92 | croak("Default timeout for ping must be greater than 0 seconds") |
93 | if $timeout <= 0; |
94 | $self->{"timeout"} = $timeout; |
95 | |
f569508e |
96 | $self->{"device"} = $device; |
97 | |
e82f584b |
98 | $min_datasize = ($proto eq "udp") ? 1 : 0; # Determine data size |
99 | $data_size = $min_datasize unless defined($data_size) && $proto ne "tcp"; |
100 | croak("Data for ping must be from $min_datasize to $max_datasize bytes") |
101 | if ($data_size < $min_datasize) || ($data_size > $max_datasize); |
102 | $data_size-- if $self->{"proto"} eq "udp"; # We provide the first byte |
103 | $self->{"data_size"} = $data_size; |
104 | |
105 | $self->{"data"} = ""; # Construct data bytes |
106 | for ($cnt = 0; $cnt < $self->{"data_size"}; $cnt++) |
107 | { |
108 | $self->{"data"} .= chr($cnt % 256); |
109 | } |
110 | |
111 | $self->{"local_addr"} = undef; # Don't bind by default |
9539e94f |
112 | $self->{"retrans"} = $def_factor; # Default exponential backoff rate |
c94ff782 |
113 | $self->{"econnrefused"} = undef; # Default Connection refused behavior |
f569508e |
114 | |
e82f584b |
115 | $self->{"seq"} = 0; # For counting packets |
116 | if ($self->{"proto"} eq "udp") # Open a socket |
117 | { |
118 | $self->{"proto_num"} = (getprotobyname('udp'))[2] || |
119 | croak("Can't udp protocol by name"); |
120 | $self->{"port_num"} = (getservbyname('echo', 'udp'))[2] || |
121 | croak("Can't get udp echo port by name"); |
122 | $self->{"fh"} = FileHandle->new(); |
123 | socket($self->{"fh"}, PF_INET, SOCK_DGRAM, |
124 | $self->{"proto_num"}) || |
125 | croak("udp socket error - $!"); |
f569508e |
126 | if ($self->{'device'}) { |
127 | setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) |
128 | or croak "error binding to device $self->{'device'} $!"; |
129 | } |
e82f584b |
130 | } |
131 | elsif ($self->{"proto"} eq "icmp") |
132 | { |
f569508e |
133 | croak("icmp ping requires root privilege") if ($> and $^O ne 'VMS' and $^O ne 'cygwin'); |
e82f584b |
134 | $self->{"proto_num"} = (getprotobyname('icmp'))[2] || |
135 | croak("Can't get icmp protocol by name"); |
136 | $self->{"pid"} = $$ & 0xffff; # Save lower 16 bits of pid |
137 | $self->{"fh"} = FileHandle->new(); |
138 | socket($self->{"fh"}, PF_INET, SOCK_RAW, $self->{"proto_num"}) || |
139 | croak("icmp socket error - $!"); |
f569508e |
140 | if ($self->{'device'}) { |
141 | setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) |
142 | or croak "error binding to device $self->{'device'} $!"; |
143 | } |
e82f584b |
144 | } |
145 | elsif ($self->{"proto"} eq "tcp" || $self->{"proto"} eq "stream") |
146 | { |
147 | $self->{"proto_num"} = (getprotobyname('tcp'))[2] || |
148 | croak("Can't get tcp protocol by name"); |
149 | $self->{"port_num"} = (getservbyname('echo', 'tcp'))[2] || |
150 | croak("Can't get tcp echo port by name"); |
151 | $self->{"fh"} = FileHandle->new(); |
152 | } |
f569508e |
153 | elsif ($self->{"proto"} eq "syn") |
154 | { |
155 | $self->{"proto_num"} = (getprotobyname('tcp'))[2] || |
156 | croak("Can't get tcp protocol by name"); |
157 | $self->{"port_num"} = (getservbyname('echo', 'tcp'))[2] || |
158 | croak("Can't get tcp echo port by name"); |
159 | if ($syn_forking) { |
160 | $self->{"fork_rd"} = FileHandle->new(); |
161 | $self->{"fork_wr"} = FileHandle->new(); |
162 | pipe($self->{"fork_rd"}, $self->{"fork_wr"}); |
163 | $self->{"fh"} = FileHandle->new(); |
69c74a9c |
164 | $self->{"good"} = {}; |
165 | $self->{"bad"} = {}; |
f569508e |
166 | } else { |
167 | $self->{"wbits"} = ""; |
168 | $self->{"bad"} = {}; |
169 | } |
170 | $self->{"syn"} = {}; |
171 | $self->{"stop_time"} = 0; |
172 | } |
173 | elsif ($self->{"proto"} eq "external") |
174 | { |
175 | # No preliminary work needs to be done. |
176 | } |
e82f584b |
177 | |
178 | return($self); |
a3b93737 |
179 | } |
a0d0e21e |
180 | |
49afa5f6 |
181 | # Description: Set the local IP address from which pings will be sent. |
182 | # For ICMP and UDP pings, this calls bind() on the already-opened socket; |
183 | # for TCP pings, just saves the address to be used when the socket is |
184 | # opened. Returns non-zero if successful; croaks on error. |
185 | sub bind |
186 | { |
e82f584b |
187 | my ($self, |
188 | $local_addr # Name or IP number of local interface |
189 | ) = @_; |
190 | my ($ip # Packed IP number of $local_addr |
191 | ); |
192 | |
193 | croak("Usage: \$p->bind(\$local_addr)") unless @_ == 2; |
194 | croak("already bound") if defined($self->{"local_addr"}) && |
195 | ($self->{"proto"} eq "udp" || $self->{"proto"} eq "icmp"); |
196 | |
197 | $ip = inet_aton($local_addr); |
198 | croak("nonexistent local address $local_addr") unless defined($ip); |
199 | $self->{"local_addr"} = $ip; # Only used if proto is tcp |
200 | |
201 | if ($self->{"proto"} eq "udp" || $self->{"proto"} eq "icmp") |
202 | { |
203 | CORE::bind($self->{"fh"}, sockaddr_in(0, $ip)) || |
204 | croak("$self->{'proto'} bind error - $!"); |
205 | } |
206 | elsif ($self->{"proto"} ne "tcp") |
207 | { |
208 | croak("Unknown protocol \"$self->{proto}\" in bind()"); |
209 | } |
210 | |
211 | return 1; |
212 | } |
49afa5f6 |
213 | |
eb194dd9 |
214 | # Description: A select() wrapper that compensates for platform |
215 | # peculiarities. |
216 | sub mselect |
217 | { |
218 | if ($_[3] > 0 and $^O eq 'MSWin32') { |
219 | # On windows, select() doesn't process the message loop, |
220 | # but sleep() will, allowing alarm() to interrupt the latter. |
221 | # So we chop up the timeout into smaller pieces and interleave |
222 | # select() and sleep() calls. |
223 | my $t = $_[3]; |
224 | my $gran = 0.5; # polling granularity in seconds |
225 | my @args = @_; |
226 | while (1) { |
227 | $gran = $t if $gran > $t; |
228 | my $nfound = select($_[0], $_[1], $_[2], $gran); |
229 | $t -= $gran; |
230 | return $nfound if $nfound or !defined($nfound) or $t <= 0; |
231 | |
232 | sleep(0); |
233 | ($_[0], $_[1], $_[2]) = @args; |
234 | } |
235 | } |
236 | else { |
237 | return select($_[0], $_[1], $_[2], $_[3]); |
238 | } |
239 | } |
49afa5f6 |
240 | |
15d96390 |
241 | # Description: Allow UDP source endpoint comparision to be |
242 | # skipped for those remote interfaces that do |
243 | # not response from the same endpoint. |
244 | |
245 | sub source_verify |
246 | { |
247 | my $self = shift; |
5d20095f |
248 | $source_verify = 1 unless defined |
249 | ($source_verify = ((defined $self) && (ref $self)) ? shift() : $self); |
15d96390 |
250 | } |
251 | |
c94ff782 |
252 | # Description: Set whether or not the connect |
253 | # behavior should enforce remote service |
254 | # availability as well as reachability. |
f569508e |
255 | |
c94ff782 |
256 | sub service_check |
f569508e |
257 | { |
258 | my $self = shift; |
c94ff782 |
259 | $self->{"econnrefused"} = 1 unless defined |
260 | ($self->{"econnrefused"} = shift()); |
261 | } |
262 | |
263 | sub tcp_service_check |
264 | { |
265 | service_check(@_); |
f569508e |
266 | } |
267 | |
9539e94f |
268 | # Description: Set exponential backoff for retransmission. |
269 | # Should be > 1 to retain exponential properties. |
270 | # If set to 0, retransmissions are disabled. |
271 | |
272 | sub retrans |
273 | { |
274 | my $self = shift; |
275 | $self->{"retrans"} = shift; |
276 | } |
277 | |
e82f584b |
278 | # Description: allows the module to use milliseconds as returned by |
279 | # the Time::HiRes module |
49afa5f6 |
280 | |
e82f584b |
281 | $hires = 0; |
282 | sub hires |
283 | { |
284 | my $self = shift; |
285 | $hires = 1 unless defined |
286 | ($hires = ((defined $self) && (ref $self)) ? shift() : $self); |
287 | require Time::HiRes if $hires; |
49afa5f6 |
288 | } |
289 | |
e82f584b |
290 | sub time |
291 | { |
292 | return $hires ? Time::HiRes::time() : CORE::time(); |
293 | } |
49afa5f6 |
294 | |
9c36735d |
295 | # Description: Sets or clears the O_NONBLOCK flag on a file handle. |
296 | sub socket_blocking_mode |
297 | { |
298 | my ($self, |
299 | $fh, # the file handle whose flags are to be modified |
300 | $block) = @_; # if true then set the blocking |
301 | # mode (clear O_NONBLOCK), otherwise |
302 | # set the non-blocking mode (set O_NONBLOCK) |
303 | |
304 | my $flags; |
eb194dd9 |
305 | if ($^O eq 'MSWin32') { |
306 | # FIONBIO enables non-blocking sockets on windows. |
307 | # FIONBIO is (0x80000000|(4<<16)|(ord('f')<<8)|126), as per winsock.h. |
308 | my $f = 0x8004667e; |
309 | my $v = pack("L", $block ? 0 : 1); |
310 | ioctl($fh, $f, $v) or croak("ioctl failed: $!"); |
311 | return; |
312 | } |
9c36735d |
313 | if ($flags = fcntl($fh, F_GETFL, 0)) { |
314 | $flags = $block ? ($flags & ~O_NONBLOCK) : ($flags | O_NONBLOCK); |
315 | if (!fcntl($fh, F_SETFL, $flags)) { |
316 | croak("fcntl F_SETFL: $!"); |
317 | } |
318 | } else { |
319 | croak("fcntl F_GETFL: $!"); |
320 | } |
321 | } |
322 | |
a3b93737 |
323 | # Description: Ping a host name or IP number with an optional timeout. |
324 | # First lookup the host, and return undef if it is not found. Otherwise |
b124990b |
325 | # perform the specific ping method based on the protocol. Return the |
a3b93737 |
326 | # result of the ping. |
327 | |
328 | sub ping |
329 | { |
e82f584b |
330 | my ($self, |
331 | $host, # Name or IP number of host to ping |
332 | $timeout, # Seconds after which ping times out |
333 | ) = @_; |
334 | my ($ip, # Packed IP number of $host |
335 | $ret, # The return value |
336 | $ping_time, # When ping began |
337 | ); |
338 | |
339 | croak("Usage: \$p->ping(\$host [, \$timeout])") unless @_ == 2 || @_ == 3; |
340 | $timeout = $self->{"timeout"} unless $timeout; |
341 | croak("Timeout must be greater than 0 seconds") if $timeout <= 0; |
342 | |
343 | $ip = inet_aton($host); |
c94ff782 |
344 | return () unless defined($ip); # Does host exist? |
e82f584b |
345 | |
346 | # Dispatch to the appropriate routine. |
347 | $ping_time = &time(); |
348 | if ($self->{"proto"} eq "external") { |
349 | $ret = $self->ping_external($ip, $timeout); |
350 | } |
351 | elsif ($self->{"proto"} eq "udp") { |
352 | $ret = $self->ping_udp($ip, $timeout); |
353 | } |
354 | elsif ($self->{"proto"} eq "icmp") { |
355 | $ret = $self->ping_icmp($ip, $timeout); |
356 | } |
357 | elsif ($self->{"proto"} eq "tcp") { |
358 | $ret = $self->ping_tcp($ip, $timeout); |
359 | } |
360 | elsif ($self->{"proto"} eq "stream") { |
361 | $ret = $self->ping_stream($ip, $timeout); |
f569508e |
362 | } |
363 | elsif ($self->{"proto"} eq "syn") { |
364 | $ret = $self->ping_syn($host, $ip, $ping_time, $ping_time+$timeout); |
e82f584b |
365 | } else { |
787ecdfa |
366 | croak("Unknown protocol \"$self->{proto}\" in ping()"); |
e82f584b |
367 | } |
368 | |
369 | return wantarray ? ($ret, &time() - $ping_time, inet_ntoa($ip)) : $ret; |
787ecdfa |
370 | } |
371 | |
372 | # Uses Net::Ping::External to do an external ping. |
373 | sub ping_external { |
374 | my ($self, |
375 | $ip, # Packed IP number of the host |
376 | $timeout # Seconds after which ping times out |
377 | ) = @_; |
378 | |
b124990b |
379 | eval { require Net::Ping::External; } |
380 | or croak('Protocol "external" not supported on your system: Net::Ping::External not found'); |
787ecdfa |
381 | return Net::Ping::External::ping(ip => $ip, timeout => $timeout); |
a3b93737 |
382 | } |
a0d0e21e |
383 | |
49afa5f6 |
384 | use constant ICMP_ECHOREPLY => 0; # ICMP packet types |
385 | use constant ICMP_ECHO => 8; |
9c36735d |
386 | use constant ICMP_STRUCT => "C2 n3 A"; # Structure of a minimal ICMP packet |
49afa5f6 |
387 | use constant SUBCODE => 0; # No ICMP subcode for ECHO and ECHOREPLY |
388 | use constant ICMP_FLAGS => 0; # No special flags for send or recv |
389 | use constant ICMP_PORT => 0; # No port with ICMP |
390 | |
a3b93737 |
391 | sub ping_icmp |
392 | { |
e82f584b |
393 | my ($self, |
394 | $ip, # Packed IP number of the host |
395 | $timeout # Seconds after which ping times out |
396 | ) = @_; |
397 | |
398 | my ($saddr, # sockaddr_in with port and ip |
399 | $checksum, # Checksum of ICMP packet |
400 | $msg, # ICMP packet to send |
401 | $len_msg, # Length of $msg |
402 | $rbits, # Read bits, filehandles for reading |
403 | $nfound, # Number of ready filehandles found |
404 | $finish_time, # Time ping should be finished |
405 | $done, # set to 1 when we are done |
406 | $ret, # Return value |
407 | $recv_msg, # Received message including IP header |
408 | $from_saddr, # sockaddr_in of sender |
409 | $from_port, # Port packet was sent from |
410 | $from_ip, # Packed IP of sender |
411 | $from_type, # ICMP type |
412 | $from_subcode, # ICMP subcode |
413 | $from_chk, # ICMP packet checksum |
414 | $from_pid, # ICMP packet id |
415 | $from_seq, # ICMP packet sequence |
416 | $from_msg # ICMP message |
417 | ); |
418 | |
419 | $self->{"seq"} = ($self->{"seq"} + 1) % 65536; # Increment sequence |
420 | $checksum = 0; # No checksum for starters |
421 | $msg = pack(ICMP_STRUCT . $self->{"data_size"}, ICMP_ECHO, SUBCODE, |
422 | $checksum, $self->{"pid"}, $self->{"seq"}, $self->{"data"}); |
423 | $checksum = Net::Ping->checksum($msg); |
424 | $msg = pack(ICMP_STRUCT . $self->{"data_size"}, ICMP_ECHO, SUBCODE, |
425 | $checksum, $self->{"pid"}, $self->{"seq"}, $self->{"data"}); |
426 | $len_msg = length($msg); |
427 | $saddr = sockaddr_in(ICMP_PORT, $ip); |
9c36735d |
428 | $self->{"from_ip"} = undef; |
429 | $self->{"from_type"} = undef; |
430 | $self->{"from_subcode"} = undef; |
e82f584b |
431 | send($self->{"fh"}, $msg, ICMP_FLAGS, $saddr); # Send the message |
432 | |
433 | $rbits = ""; |
434 | vec($rbits, $self->{"fh"}->fileno(), 1) = 1; |
435 | $ret = 0; |
436 | $done = 0; |
437 | $finish_time = &time() + $timeout; # Must be done by this time |
438 | while (!$done && $timeout > 0) # Keep trying if we have time |
439 | { |
eb194dd9 |
440 | $nfound = mselect((my $rout=$rbits), undef, undef, $timeout); # Wait for packet |
e82f584b |
441 | $timeout = $finish_time - &time(); # Get remaining time |
442 | if (!defined($nfound)) # Hmm, a strange error |
a3b93737 |
443 | { |
e82f584b |
444 | $ret = undef; |
445 | $done = 1; |
446 | } |
447 | elsif ($nfound) # Got a packet from somewhere |
448 | { |
449 | $recv_msg = ""; |
9539e94f |
450 | $from_pid = -1; |
451 | $from_seq = -1; |
e82f584b |
452 | $from_saddr = recv($self->{"fh"}, $recv_msg, 1500, ICMP_FLAGS); |
453 | ($from_port, $from_ip) = sockaddr_in($from_saddr); |
9c36735d |
454 | ($from_type, $from_subcode) = unpack("C2", substr($recv_msg, 20, 2)); |
9539e94f |
455 | if ($from_type == ICMP_ECHOREPLY) { |
456 | ($from_pid, $from_seq) = unpack("n3", substr($recv_msg, 24, 4)) |
457 | if length $recv_msg >= 28; |
9c36735d |
458 | } else { |
9539e94f |
459 | ($from_pid, $from_seq) = unpack("n3", substr($recv_msg, 52, 4)) |
460 | if length $recv_msg >= 56; |
9c36735d |
461 | } |
462 | $self->{"from_ip"} = $from_ip; |
463 | $self->{"from_type"} = $from_type; |
464 | $self->{"from_subcode"} = $from_subcode; |
465 | if (($from_pid == $self->{"pid"}) && # Does the packet check out? |
466 | ($from_seq == $self->{"seq"})) { |
467 | if ($from_type == ICMP_ECHOREPLY){ |
468 | $ret = 1; |
469 | } |
e82f584b |
470 | $done = 1; |
471 | } |
9c36735d |
472 | } else { # Oops, timed out |
e82f584b |
473 | $done = 1; |
474 | } |
475 | } |
476 | return $ret; |
a3b93737 |
477 | } |
478 | |
9c36735d |
479 | sub icmp_result { |
480 | my ($self) = @_; |
481 | my $ip = $self->{"from_ip"} || ""; |
482 | $ip = "\0\0\0\0" unless 4 == length $ip; |
483 | return (inet_ntoa($ip),($self->{"from_type"} || 0), ($self->{"from_subcode"} || 0)); |
484 | } |
485 | |
a3b93737 |
486 | # Description: Do a checksum on the message. Basically sum all of |
487 | # the short words and fold the high order bits into the low order bits. |
488 | |
489 | sub checksum |
490 | { |
e82f584b |
491 | my ($class, |
492 | $msg # The message to checksum |
493 | ) = @_; |
494 | my ($len_msg, # Length of the message |
495 | $num_short, # The number of short words in the message |
496 | $short, # One short word |
497 | $chk # The checksum |
498 | ); |
499 | |
500 | $len_msg = length($msg); |
501 | $num_short = int($len_msg / 2); |
502 | $chk = 0; |
9c36735d |
503 | foreach $short (unpack("n$num_short", $msg)) |
e82f584b |
504 | { |
505 | $chk += $short; |
506 | } # Add the odd byte in |
507 | $chk += (unpack("C", substr($msg, $len_msg - 1, 1)) << 8) if $len_msg % 2; |
508 | $chk = ($chk >> 16) + ($chk & 0xffff); # Fold high into low |
509 | return(~(($chk >> 16) + $chk) & 0xffff); # Again and complement |
a3b93737 |
510 | } |
511 | |
787ecdfa |
512 | |
b124990b |
513 | # Description: Perform a tcp echo ping. Since a tcp connection is |
514 | # host specific, we have to open and close each connection here. We |
515 | # can't just leave a socket open. Because of the robust nature of |
516 | # tcp, it will take a while before it gives up trying to establish a |
517 | # connection. Therefore, we use select() on a non-blocking socket to |
518 | # check against our timeout. No data bytes are actually |
519 | # sent since the successful establishment of a connection is proof |
520 | # enough of the reachability of the remote host. Also, tcp is |
521 | # expensive and doesn't need our help to add to the overhead. |
522 | |
523 | sub ping_tcp |
787ecdfa |
524 | { |
e82f584b |
525 | my ($self, |
526 | $ip, # Packed IP number of the host |
527 | $timeout # Seconds after which ping times out |
528 | ) = @_; |
529 | my ($ret # The return value |
530 | ); |
531 | |
9c36735d |
532 | $! = 0; |
e82f584b |
533 | $ret = $self -> tcp_connect( $ip, $timeout); |
c94ff782 |
534 | if (!$self->{"econnrefused"} && |
f569508e |
535 | $! == ECONNREFUSED) { |
536 | $ret = 1; # "Connection refused" means reachable |
537 | } |
e82f584b |
538 | $self->{"fh"}->close(); |
539 | return $ret; |
787ecdfa |
540 | } |
541 | |
b124990b |
542 | sub tcp_connect |
787ecdfa |
543 | { |
e82f584b |
544 | my ($self, |
545 | $ip, # Packed IP number of the host |
546 | $timeout # Seconds after which connect times out |
547 | ) = @_; |
548 | my ($saddr); # Packed IP and Port |
b124990b |
549 | |
e82f584b |
550 | $saddr = sockaddr_in($self->{"port_num"}, $ip); |
b124990b |
551 | |
e82f584b |
552 | my $ret = 0; # Default to unreachable |
b124990b |
553 | |
e82f584b |
554 | my $do_socket = sub { |
555 | socket($self->{"fh"}, PF_INET, SOCK_STREAM, $self->{"proto_num"}) || |
556 | croak("tcp socket error - $!"); |
557 | if (defined $self->{"local_addr"} && |
558 | !CORE::bind($self->{"fh"}, sockaddr_in(0, $self->{"local_addr"}))) { |
559 | croak("tcp bind error - $!"); |
560 | } |
f569508e |
561 | if ($self->{'device'}) { |
562 | setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) |
563 | or croak("error binding to device $self->{'device'} $!"); |
564 | } |
e82f584b |
565 | }; |
566 | my $do_connect = sub { |
9c36735d |
567 | $self->{"ip"} = $ip; |
6dbac12b |
568 | # ECONNREFUSED is 10061 on MSWin32. If we pass it as child error through $?, |
569 | # we'll get (10061 & 255) = 77, so we cannot check it in the parent process. |
570 | return ($ret = connect($self->{"fh"}, $saddr) || ($! == ECONNREFUSED && !$self->{"econnrefused"})); |
e82f584b |
571 | }; |
9c36735d |
572 | my $do_connect_nb = sub { |
573 | # Set O_NONBLOCK property on filehandle |
574 | $self->socket_blocking_mode($self->{"fh"}, 0); |
575 | |
576 | # start the connection attempt |
577 | if (!connect($self->{"fh"}, $saddr)) { |
578 | if ($! == ECONNREFUSED) { |
c94ff782 |
579 | $ret = 1 unless $self->{"econnrefused"}; |
eb194dd9 |
580 | } elsif ($! != EINPROGRESS && ($^O ne 'MSWin32' || $! != EWOULDBLOCK)) { |
9c36735d |
581 | # EINPROGRESS is the expected error code after a connect() |
c94ff782 |
582 | # on a non-blocking socket. But if the kernel immediately |
583 | # determined that this connect() will never work, |
584 | # Simply respond with "unreachable" status. |
585 | # (This can occur on some platforms with errno |
586 | # EHOSTUNREACH or ENETUNREACH.) |
587 | return 0; |
588 | } else { |
589 | # Got the expected EINPROGRESS. |
590 | # Just wait for connection completion... |
eb194dd9 |
591 | my ($wbits, $wout, $wexc); |
592 | $wout = $wexc = $wbits = ""; |
9c36735d |
593 | vec($wbits, $self->{"fh"}->fileno, 1) = 1; |
594 | |
eb194dd9 |
595 | my $nfound = mselect(undef, |
596 | ($wout = $wbits), |
597 | ($^O eq 'MSWin32' ? ($wexc = $wbits) : undef), |
598 | $timeout); |
9c36735d |
599 | warn("select: $!") unless defined $nfound; |
600 | |
601 | if ($nfound && vec($wout, $self->{"fh"}->fileno, 1)) { |
602 | # the socket is ready for writing so the connection |
603 | # attempt completed. test whether the connection |
604 | # attempt was successful or not |
605 | |
606 | if (getpeername($self->{"fh"})) { |
607 | # Connection established to remote host |
608 | $ret = 1; |
609 | } else { |
610 | # TCP ACK will never come from this host |
611 | # because there was an error connecting. |
e82f584b |
612 | |
9c36735d |
613 | # This should set $! to the correct error. |
614 | my $char; |
615 | sysread($self->{"fh"},$char,1); |
616 | $! = ECONNREFUSED if ($! == EAGAIN && $^O =~ /cygwin/i); |
e82f584b |
617 | |
c94ff782 |
618 | $ret = 1 if (!$self->{"econnrefused"} |
9c36735d |
619 | && $! == ECONNREFUSED); |
620 | } |
621 | } else { |
eb194dd9 |
622 | # the connection attempt timed out (or there were connect |
623 | # errors on Windows) |
624 | if ($^O =~ 'MSWin32') { |
625 | # If the connect will fail on a non-blocking socket, |
626 | # winsock reports ECONNREFUSED as an exception, and we |
627 | # need to fetch the socket-level error code via getsockopt() |
628 | # instead of using the thread-level error code that is in $!. |
629 | if ($nfound && vec($wexc, $self->{"fh"}->fileno, 1)) { |
630 | $! = unpack("i", getsockopt($self->{"fh"}, SOL_SOCKET, |
631 | SO_ERROR)); |
632 | } |
633 | } |
9c36735d |
634 | } |
635 | } |
636 | } else { |
637 | # Connection established to remote host |
638 | $ret = 1; |
639 | } |
640 | |
641 | # Unset O_NONBLOCK property on filehandle |
642 | $self->socket_blocking_mode($self->{"fh"}, 1); |
643 | $self->{"ip"} = $ip; |
644 | return $ret; |
645 | }; |
646 | |
647 | if ($syn_forking) { |
648 | # Buggy Winsock API doesn't allow nonblocking connect. |
e82f584b |
649 | # Hence, if our OS is Windows, we need to create a separate |
650 | # process to do the blocking connect attempt. |
eb194dd9 |
651 | # XXX Above comments are not true at least for Win2K, where |
652 | # nonblocking connect works. |
e82f584b |
653 | |
654 | $| = 1; # Clear buffer prior to fork to prevent duplicate flushing. |
9c36735d |
655 | $self->{'tcp_chld'} = fork; |
656 | if (!$self->{'tcp_chld'}) { |
657 | if (!defined $self->{'tcp_chld'}) { |
e82f584b |
658 | # Fork did not work |
9c36735d |
659 | warn "Fork error: $!"; |
e82f584b |
660 | return 0; |
b124990b |
661 | } |
b124990b |
662 | &{ $do_socket }(); |
663 | |
e82f584b |
664 | # Try a slow blocking connect() call |
9c36735d |
665 | # and report the status to the parent. |
e82f584b |
666 | if ( &{ $do_connect }() ) { |
667 | $self->{"fh"}->close(); |
668 | # No error |
669 | exit 0; |
b124990b |
670 | } else { |
e82f584b |
671 | # Pass the error status to the parent |
6dbac12b |
672 | # Make sure that $! <= 255 |
673 | exit($! <= 255 ? $! : 255); |
b124990b |
674 | } |
e82f584b |
675 | } |
b124990b |
676 | |
e82f584b |
677 | &{ $do_socket }(); |
678 | |
679 | my $patience = &time() + $timeout; |
680 | |
9c36735d |
681 | my ($child, $child_errno); |
682 | $? = 0; $child_errno = 0; |
e82f584b |
683 | # Wait up to the timeout |
684 | # And clean off the zombie |
685 | do { |
9c36735d |
686 | $child = waitpid($self->{'tcp_chld'}, &WNOHANG()); |
687 | $child_errno = $? >> 8; |
e82f584b |
688 | select(undef, undef, undef, 0.1); |
9c36735d |
689 | } while &time() < $patience && $child != $self->{'tcp_chld'}; |
690 | |
691 | if ($child == $self->{'tcp_chld'}) { |
692 | if ($self->{"proto"} eq "stream") { |
693 | # We need the socket connected here, in parent |
694 | # Should be safe to connect because the child finished |
695 | # within the timeout |
696 | &{ $do_connect }(); |
697 | } |
6dbac12b |
698 | # $ret cannot be set by the child process |
699 | $ret = !$child_errno; |
e82f584b |
700 | } else { |
701 | # Time must have run out. |
e82f584b |
702 | # Put that choking client out of its misery |
9c36735d |
703 | kill "KILL", $self->{'tcp_chld'}; |
e82f584b |
704 | # Clean off the zombie |
9c36735d |
705 | waitpid($self->{'tcp_chld'}, 0); |
e82f584b |
706 | $ret = 0; |
b124990b |
707 | } |
9c36735d |
708 | delete $self->{'tcp_chld'}; |
709 | $! = $child_errno; |
710 | } else { |
e82f584b |
711 | # Otherwise don't waste the resources to fork |
712 | |
713 | &{ $do_socket }(); |
714 | |
9c36735d |
715 | &{ $do_connect_nb }(); |
e82f584b |
716 | } |
787ecdfa |
717 | |
e82f584b |
718 | return $ret; |
787ecdfa |
719 | } |
720 | |
9c36735d |
721 | sub DESTROY { |
722 | my $self = shift; |
723 | if ($self->{'proto'} eq 'tcp' && |
724 | $self->{'tcp_chld'}) { |
725 | # Put that choking client out of its misery |
726 | kill "KILL", $self->{'tcp_chld'}; |
727 | # Clean off the zombie |
728 | waitpid($self->{'tcp_chld'}, 0); |
729 | } |
730 | } |
731 | |
787ecdfa |
732 | # This writes the given string to the socket and then reads it |
733 | # back. It returns 1 on success, 0 on failure. |
734 | sub tcp_echo |
735 | { |
e82f584b |
736 | my $self = shift; |
737 | my $timeout = shift; |
738 | my $pingstring = shift; |
739 | |
740 | my $ret = undef; |
741 | my $time = &time(); |
742 | my $wrstr = $pingstring; |
743 | my $rdstr = ""; |
744 | |
745 | eval <<'EOM'; |
746 | do { |
747 | my $rin = ""; |
748 | vec($rin, $self->{"fh"}->fileno(), 1) = 1; |
749 | |
750 | my $rout = undef; |
751 | if($wrstr) { |
752 | $rout = ""; |
753 | vec($rout, $self->{"fh"}->fileno(), 1) = 1; |
754 | } |
755 | |
eb194dd9 |
756 | if(mselect($rin, $rout, undef, ($time + $timeout) - &time())) { |
e82f584b |
757 | |
758 | if($rout && vec($rout,$self->{"fh"}->fileno(),1)) { |
9c36735d |
759 | my $num = syswrite($self->{"fh"}, $wrstr, length $wrstr); |
e82f584b |
760 | if($num) { |
761 | # If it was a partial write, update and try again. |
762 | $wrstr = substr($wrstr,$num); |
763 | } else { |
764 | # There was an error. |
765 | $ret = 0; |
766 | } |
767 | } |
768 | |
769 | if(vec($rin,$self->{"fh"}->fileno(),1)) { |
770 | my $reply; |
771 | if(sysread($self->{"fh"},$reply,length($pingstring)-length($rdstr))) { |
772 | $rdstr .= $reply; |
773 | $ret = 1 if $rdstr eq $pingstring; |
774 | } else { |
775 | # There was an error. |
776 | $ret = 0; |
777 | } |
778 | } |
779 | |
780 | } |
781 | } until &time() > ($time + $timeout) || defined($ret); |
787ecdfa |
782 | EOM |
783 | |
e82f584b |
784 | return $ret; |
787ecdfa |
785 | } |
786 | |
787ecdfa |
787 | |
787ecdfa |
788 | |
787ecdfa |
789 | |
790 | # Description: Perform a stream ping. If the tcp connection isn't |
791 | # already open, it opens it. It then sends some data and waits for |
792 | # a reply. It leaves the stream open on exit. |
793 | |
794 | sub ping_stream |
795 | { |
e82f584b |
796 | my ($self, |
797 | $ip, # Packed IP number of the host |
798 | $timeout # Seconds after which ping times out |
799 | ) = @_; |
072620d9 |
800 | |
e82f584b |
801 | # Open the stream if it's not already open |
802 | if(!defined $self->{"fh"}->fileno()) { |
803 | $self->tcp_connect($ip, $timeout) or return 0; |
804 | } |
787ecdfa |
805 | |
e82f584b |
806 | croak "tried to switch servers while stream pinging" |
807 | if $self->{"ip"} ne $ip; |
808 | |
809 | return $self->tcp_echo($timeout, $pingstring); |
787ecdfa |
810 | } |
811 | |
812 | # Description: opens the stream. You would do this if you want to |
813 | # separate the overhead of opening the stream from the first ping. |
814 | |
815 | sub open |
816 | { |
e82f584b |
817 | my ($self, |
818 | $host, # Host or IP address |
819 | $timeout # Seconds after which open times out |
820 | ) = @_; |
821 | |
822 | my ($ip); # Packed IP number of the host |
823 | $ip = inet_aton($host); |
824 | $timeout = $self->{"timeout"} unless $timeout; |
825 | |
826 | if($self->{"proto"} eq "stream") { |
827 | if(defined($self->{"fh"}->fileno())) { |
828 | croak("socket is already open"); |
829 | } else { |
830 | $self->tcp_connect($ip, $timeout); |
b124990b |
831 | } |
e82f584b |
832 | } |
072620d9 |
833 | } |
834 | |
b124990b |
835 | |
a3b93737 |
836 | # Description: Perform a udp echo ping. Construct a message of |
837 | # at least the one-byte sequence number and any additional data bytes. |
838 | # Send the message out and wait for a message to come back. If we |
839 | # get a message, make sure all of its parts match. If they do, we are |
840 | # done. Otherwise go back and wait for the message until we run out |
841 | # of time. Return the result of our efforts. |
842 | |
49afa5f6 |
843 | use constant UDP_FLAGS => 0; # Nothing special on send or recv |
a3b93737 |
844 | sub ping_udp |
845 | { |
e82f584b |
846 | my ($self, |
847 | $ip, # Packed IP number of the host |
848 | $timeout # Seconds after which ping times out |
849 | ) = @_; |
850 | |
851 | my ($saddr, # sockaddr_in with port and ip |
852 | $ret, # The return value |
853 | $msg, # Message to be echoed |
854 | $finish_time, # Time ping should be finished |
9539e94f |
855 | $flush, # Whether socket needs to be disconnected |
856 | $connect, # Whether socket needs to be connected |
e82f584b |
857 | $done, # Set to 1 when we are done pinging |
858 | $rbits, # Read bits, filehandles for reading |
859 | $nfound, # Number of ready filehandles found |
860 | $from_saddr, # sockaddr_in of sender |
861 | $from_msg, # Characters echoed by $host |
862 | $from_port, # Port message was echoed from |
863 | $from_ip # Packed IP number of sender |
864 | ); |
865 | |
866 | $saddr = sockaddr_in($self->{"port_num"}, $ip); |
867 | $self->{"seq"} = ($self->{"seq"} + 1) % 256; # Increment sequence |
868 | $msg = chr($self->{"seq"}) . $self->{"data"}; # Add data if any |
9539e94f |
869 | |
870 | if ($self->{"connected"}) { |
871 | if ($self->{"connected"} ne $saddr) { |
872 | # Still connected to wrong destination. |
873 | # Need to flush out the old one. |
874 | $flush = 1; |
875 | } |
876 | } else { |
877 | # Not connected yet. |
878 | # Need to connect() before send() |
879 | $connect = 1; |
880 | } |
881 | |
c94ff782 |
882 | # Have to connect() and send() instead of sendto() |
883 | # in order to pick up on the ECONNREFUSED setting |
884 | # from recv() or double send() errno as utilized in |
885 | # the concept by rdw @ perlmonks. See: |
886 | # http://perlmonks.thepen.com/42898.html |
9539e94f |
887 | if ($flush) { |
888 | # Need to socket() again to flush the descriptor |
889 | # This will disconnect from the old saddr. |
890 | socket($self->{"fh"}, PF_INET, SOCK_DGRAM, |
891 | $self->{"proto_num"}); |
892 | } |
893 | # Connect the socket if it isn't already connected |
894 | # to the right destination. |
895 | if ($flush || $connect) { |
896 | connect($self->{"fh"}, $saddr); # Tie destination to socket |
897 | $self->{"connected"} = $saddr; |
898 | } |
c94ff782 |
899 | send($self->{"fh"}, $msg, UDP_FLAGS); # Send it |
e82f584b |
900 | |
901 | $rbits = ""; |
902 | vec($rbits, $self->{"fh"}->fileno(), 1) = 1; |
903 | $ret = 0; # Default to unreachable |
904 | $done = 0; |
c94ff782 |
905 | my $retrans = 0.01; |
9539e94f |
906 | my $factor = $self->{"retrans"}; |
e82f584b |
907 | $finish_time = &time() + $timeout; # Ping needs to be done by then |
908 | while (!$done && $timeout > 0) |
909 | { |
9539e94f |
910 | if ($factor > 1) |
911 | { |
912 | $timeout = $retrans if $timeout > $retrans; |
913 | $retrans*= $factor; # Exponential backoff |
914 | } |
eb194dd9 |
915 | $nfound = mselect((my $rout=$rbits), undef, undef, $timeout); # Wait for response |
c94ff782 |
916 | my $why = $!; |
e82f584b |
917 | $timeout = $finish_time - &time(); # Get remaining time |
918 | |
919 | if (!defined($nfound)) # Hmm, a strange error |
a3b93737 |
920 | { |
e82f584b |
921 | $ret = undef; |
922 | $done = 1; |
a3b93737 |
923 | } |
e82f584b |
924 | elsif ($nfound) # A packet is waiting |
925 | { |
926 | $from_msg = ""; |
c94ff782 |
927 | $from_saddr = recv($self->{"fh"}, $from_msg, 1500, UDP_FLAGS); |
928 | if (!$from_saddr) { |
929 | # For example an unreachable host will make recv() fail. |
930 | if (!$self->{"econnrefused"} && |
9539e94f |
931 | ($! == ECONNREFUSED || |
932 | $! == ECONNRESET)) { |
c94ff782 |
933 | # "Connection refused" means reachable |
934 | # Good, continue |
935 | $ret = 1; |
936 | } |
e82f584b |
937 | $done = 1; |
c94ff782 |
938 | } else { |
939 | ($from_port, $from_ip) = sockaddr_in($from_saddr); |
940 | if (!$source_verify || |
941 | (($from_ip eq $ip) && # Does the packet check out? |
942 | ($from_port == $self->{"port_num"}) && |
943 | ($from_msg eq $msg))) |
944 | { |
945 | $ret = 1; # It's a winner |
946 | $done = 1; |
947 | } |
e82f584b |
948 | } |
949 | } |
c94ff782 |
950 | elsif ($timeout <= 0) # Oops, timed out |
e82f584b |
951 | { |
952 | $done = 1; |
953 | } |
c94ff782 |
954 | else |
955 | { |
956 | # Send another in case the last one dropped |
957 | if (send($self->{"fh"}, $msg, UDP_FLAGS)) { |
958 | # Another send worked? The previous udp packet |
959 | # must have gotten lost or is still in transit. |
960 | # Hopefully this new packet will arrive safely. |
961 | } else { |
962 | if (!$self->{"econnrefused"} && |
963 | $! == ECONNREFUSED) { |
964 | # "Connection refused" means reachable |
965 | # Good, continue |
966 | $ret = 1; |
967 | } |
968 | $done = 1; |
969 | } |
970 | } |
e82f584b |
971 | } |
a5a165b1 |
972 | return $ret; |
b124990b |
973 | } |
a0d0e21e |
974 | |
f569508e |
975 | # Description: Send a TCP SYN packet to host specified. |
976 | sub ping_syn |
977 | { |
978 | my $self = shift; |
979 | my $host = shift; |
980 | my $ip = shift; |
981 | my $start_time = shift; |
982 | my $stop_time = shift; |
983 | |
984 | if ($syn_forking) { |
985 | return $self->ping_syn_fork($host, $ip, $start_time, $stop_time); |
986 | } |
987 | |
988 | my $fh = FileHandle->new(); |
989 | my $saddr = sockaddr_in($self->{"port_num"}, $ip); |
990 | |
991 | # Create TCP socket |
992 | if (!socket ($fh, PF_INET, SOCK_STREAM, $self->{"proto_num"})) { |
993 | croak("tcp socket error - $!"); |
994 | } |
995 | |
996 | if (defined $self->{"local_addr"} && |
997 | !CORE::bind($fh, sockaddr_in(0, $self->{"local_addr"}))) { |
998 | croak("tcp bind error - $!"); |
999 | } |
1000 | |
1001 | if ($self->{'device'}) { |
1002 | setsockopt($fh, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) |
1003 | or croak("error binding to device $self->{'device'} $!"); |
1004 | } |
1005 | |
1006 | # Set O_NONBLOCK property on filehandle |
9c36735d |
1007 | $self->socket_blocking_mode($fh, 0); |
f569508e |
1008 | |
1009 | # Attempt the non-blocking connect |
1010 | # by just sending the TCP SYN packet |
1011 | if (connect($fh, $saddr)) { |
1012 | # Non-blocking, yet still connected? |
69c74a9c |
1013 | # Must have connected very quickly, |
1014 | # or else it wasn't very non-blocking. |
1015 | #warn "WARNING: Nonblocking connect connected anyway? ($^O)"; |
1016 | } else { |
f569508e |
1017 | # Error occurred connecting. |
eb194dd9 |
1018 | if ($! == EINPROGRESS || ($^O eq 'MSWin32' && $! == EWOULDBLOCK)) { |
69c74a9c |
1019 | # The connection is just still in progress. |
1020 | # This is the expected condition. |
1021 | } else { |
1022 | # Just save the error and continue on. |
1023 | # The ack() can check the status later. |
f569508e |
1024 | $self->{"bad"}->{$host} = $!; |
f569508e |
1025 | } |
1026 | } |
1027 | |
1028 | my $entry = [ $host, $ip, $fh, $start_time, $stop_time ]; |
1029 | $self->{"syn"}->{$fh->fileno} = $entry; |
1030 | if ($self->{"stop_time"} < $stop_time) { |
1031 | $self->{"stop_time"} = $stop_time; |
1032 | } |
1033 | vec($self->{"wbits"}, $fh->fileno, 1) = 1; |
1034 | |
1035 | return 1; |
1036 | } |
1037 | |
1038 | sub ping_syn_fork { |
1039 | my ($self, $host, $ip, $start_time, $stop_time) = @_; |
1040 | |
1041 | # Buggy Winsock API doesn't allow nonblocking connect. |
1042 | # Hence, if our OS is Windows, we need to create a separate |
1043 | # process to do the blocking connect attempt. |
1044 | my $pid = fork(); |
1045 | if (defined $pid) { |
1046 | if ($pid) { |
1047 | # Parent process |
1048 | my $entry = [ $host, $ip, $pid, $start_time, $stop_time ]; |
1049 | $self->{"syn"}->{$pid} = $entry; |
1050 | if ($self->{"stop_time"} < $stop_time) { |
1051 | $self->{"stop_time"} = $stop_time; |
1052 | } |
1053 | } else { |
1054 | # Child process |
1055 | my $saddr = sockaddr_in($self->{"port_num"}, $ip); |
1056 | |
1057 | # Create TCP socket |
1058 | if (!socket ($self->{"fh"}, PF_INET, SOCK_STREAM, $self->{"proto_num"})) { |
1059 | croak("tcp socket error - $!"); |
1060 | } |
1061 | |
1062 | if (defined $self->{"local_addr"} && |
1063 | !CORE::bind($self->{"fh"}, sockaddr_in(0, $self->{"local_addr"}))) { |
1064 | croak("tcp bind error - $!"); |
1065 | } |
1066 | |
1067 | if ($self->{'device'}) { |
1068 | setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) |
1069 | or croak("error binding to device $self->{'device'} $!"); |
1070 | } |
1071 | |
1072 | $!=0; |
1073 | # Try to connect (could take a long time) |
1074 | connect($self->{"fh"}, $saddr); |
1075 | # Notify parent of connect error status |
1076 | my $err = $!+0; |
1077 | my $wrstr = "$$ $err"; |
9c36735d |
1078 | # Force to 16 chars including \n |
1079 | $wrstr .= " "x(15 - length $wrstr). "\n"; |
1080 | syswrite($self->{"fork_wr"}, $wrstr, length $wrstr); |
f569508e |
1081 | exit; |
1082 | } |
1083 | } else { |
1084 | # fork() failed? |
1085 | die "fork: $!"; |
1086 | } |
1087 | return 1; |
1088 | } |
1089 | |
1090 | # Description: Wait for TCP ACK from host specified |
1091 | # from ping_syn above. If no host is specified, wait |
1092 | # for TCP ACK from any of the hosts in the SYN queue. |
1093 | sub ack |
1094 | { |
1095 | my $self = shift; |
1096 | |
1097 | if ($self->{"proto"} eq "syn") { |
1098 | if ($syn_forking) { |
1099 | my @answer = $self->ack_unfork(shift); |
1100 | return wantarray ? @answer : $answer[0]; |
1101 | } |
1102 | my $wbits = ""; |
1103 | my $stop_time = 0; |
1104 | if (my $host = shift) { |
1105 | # Host passed as arg |
1106 | if (exists $self->{"bad"}->{$host}) { |
c94ff782 |
1107 | if (!$self->{"econnrefused"} && |
69c74a9c |
1108 | $self->{"bad"}->{ $host } && |
1109 | (($! = ECONNREFUSED)>0) && |
1110 | $self->{"bad"}->{ $host } eq "$!") { |
1111 | # "Connection refused" means reachable |
1112 | # Good, continue |
1113 | } else { |
1114 | # ECONNREFUSED means no good |
1115 | return (); |
1116 | } |
f569508e |
1117 | } |
1118 | my $host_fd = undef; |
1119 | foreach my $fd (keys %{ $self->{"syn"} }) { |
1120 | my $entry = $self->{"syn"}->{$fd}; |
1121 | if ($entry->[0] eq $host) { |
1122 | $host_fd = $fd; |
1123 | $stop_time = $entry->[4] |
1124 | || croak("Corrupted SYN entry for [$host]"); |
1125 | last; |
1126 | } |
1127 | } |
1128 | croak("ack called on [$host] without calling ping first!") |
1129 | unless defined $host_fd; |
1130 | vec($wbits, $host_fd, 1) = 1; |
1131 | } else { |
1132 | # No $host passed so scan all hosts |
1133 | # Use the latest stop_time |
1134 | $stop_time = $self->{"stop_time"}; |
1135 | # Use all the bits |
1136 | $wbits = $self->{"wbits"}; |
1137 | } |
1138 | |
9c36735d |
1139 | while ($wbits !~ /^\0*\z/) { |
f569508e |
1140 | my $timeout = $stop_time - &time(); |
1141 | # Force a minimum of 10 ms timeout. |
69c74a9c |
1142 | $timeout = 0.01 if $timeout <= 0.01; |
1143 | |
1144 | my $winner_fd = undef; |
1145 | my $wout = $wbits; |
1146 | my $fd = 0; |
1147 | # Do "bad" fds from $wbits first |
9c36735d |
1148 | while ($wout !~ /^\0*\z/) { |
69c74a9c |
1149 | if (vec($wout, $fd, 1)) { |
1150 | # Wipe it from future scanning. |
1151 | vec($wout, $fd, 1) = 0; |
1152 | if (my $entry = $self->{"syn"}->{$fd}) { |
1153 | if ($self->{"bad"}->{ $entry->[0] }) { |
1154 | $winner_fd = $fd; |
1155 | last; |
1156 | } |
1157 | } |
1158 | } |
1159 | $fd++; |
1160 | } |
1161 | |
eb194dd9 |
1162 | if (defined($winner_fd) or my $nfound = mselect(undef, ($wout=$wbits), undef, $timeout)) { |
69c74a9c |
1163 | if (defined $winner_fd) { |
1164 | $fd = $winner_fd; |
1165 | } else { |
1166 | # Done waiting for one of the ACKs |
1167 | $fd = 0; |
1168 | # Determine which one |
9c36735d |
1169 | while ($wout !~ /^\0*\z/ && |
69c74a9c |
1170 | !vec($wout, $fd, 1)) { |
1171 | $fd++; |
1172 | } |
f569508e |
1173 | } |
1174 | if (my $entry = $self->{"syn"}->{$fd}) { |
69c74a9c |
1175 | # Wipe it from future scanning. |
1176 | delete $self->{"syn"}->{$fd}; |
1177 | vec($self->{"wbits"}, $fd, 1) = 0; |
1178 | vec($wbits, $fd, 1) = 0; |
c94ff782 |
1179 | if (!$self->{"econnrefused"} && |
69c74a9c |
1180 | $self->{"bad"}->{ $entry->[0] } && |
1181 | (($! = ECONNREFUSED)>0) && |
1182 | $self->{"bad"}->{ $entry->[0] } eq "$!") { |
1183 | # "Connection refused" means reachable |
1184 | # Good, continue |
1185 | } elsif (getpeername($entry->[2])) { |
f569508e |
1186 | # Connection established to remote host |
69c74a9c |
1187 | # Good, continue |
f569508e |
1188 | } else { |
1189 | # TCP ACK will never come from this host |
1190 | # because there was an error connecting. |
1191 | |
f569508e |
1192 | # This should set $! to the correct error. |
1193 | my $char; |
9c36735d |
1194 | sysread($entry->[2],$char,1); |
f569508e |
1195 | # Store the excuse why the connection failed. |
1196 | $self->{"bad"}->{$entry->[0]} = $!; |
c94ff782 |
1197 | if (!$self->{"econnrefused"} && |
69c74a9c |
1198 | (($! == ECONNREFUSED) || |
1199 | ($! == EAGAIN && $^O =~ /cygwin/i))) { |
f569508e |
1200 | # "Connection refused" means reachable |
69c74a9c |
1201 | # Good, continue |
1202 | } else { |
1203 | # No good, try the next socket... |
1204 | next; |
f569508e |
1205 | } |
f569508e |
1206 | } |
69c74a9c |
1207 | # Everything passed okay, return the answer |
1208 | return wantarray ? |
1209 | ($entry->[0], &time() - $entry->[3], inet_ntoa($entry->[1])) |
1210 | : $entry->[0]; |
f569508e |
1211 | } else { |
1212 | warn "Corrupted SYN entry: unknown fd [$fd] ready!"; |
1213 | vec($wbits, $fd, 1) = 0; |
1214 | vec($self->{"wbits"}, $fd, 1) = 0; |
1215 | } |
1216 | } elsif (defined $nfound) { |
1217 | # Timed out waiting for ACK |
1218 | foreach my $fd (keys %{ $self->{"syn"} }) { |
1219 | if (vec($wbits, $fd, 1)) { |
1220 | my $entry = $self->{"syn"}->{$fd}; |
1221 | $self->{"bad"}->{$entry->[0]} = "Timed out"; |
1222 | vec($wbits, $fd, 1) = 0; |
1223 | vec($self->{"wbits"}, $fd, 1) = 0; |
1224 | delete $self->{"syn"}->{$fd}; |
1225 | } |
1226 | } |
1227 | } else { |
1228 | # Weird error occurred with select() |
1229 | warn("select: $!"); |
1230 | $self->{"syn"} = {}; |
1231 | $wbits = ""; |
1232 | } |
1233 | } |
1234 | } |
1235 | return (); |
1236 | } |
1237 | |
1238 | sub ack_unfork { |
69c74a9c |
1239 | my ($self,$host) = @_; |
f569508e |
1240 | my $stop_time = $self->{"stop_time"}; |
69c74a9c |
1241 | if ($host) { |
f569508e |
1242 | # Host passed as arg |
69c74a9c |
1243 | if (my $entry = $self->{"good"}->{$host}) { |
1244 | delete $self->{"good"}->{$host}; |
1245 | return ($entry->[0], &time() - $entry->[3], inet_ntoa($entry->[1])); |
1246 | } |
f569508e |
1247 | } |
1248 | |
1249 | my $rbits = ""; |
1250 | my $timeout; |
69c74a9c |
1251 | |
f569508e |
1252 | if (keys %{ $self->{"syn"} }) { |
1253 | # Scan all hosts that are left |
1254 | vec($rbits, fileno($self->{"fork_rd"}), 1) = 1; |
1255 | $timeout = $stop_time - &time(); |
69c74a9c |
1256 | # Force a minimum of 10 ms timeout. |
1257 | $timeout = 0.01 if $timeout < 0.01; |
f569508e |
1258 | } else { |
1259 | # No hosts left to wait for |
1260 | $timeout = 0; |
1261 | } |
1262 | |
1263 | if ($timeout > 0) { |
69c74a9c |
1264 | my $nfound; |
1265 | while ( keys %{ $self->{"syn"} } and |
eb194dd9 |
1266 | $nfound = mselect((my $rout=$rbits), undef, undef, $timeout)) { |
f569508e |
1267 | # Done waiting for one of the ACKs |
9c36735d |
1268 | if (!sysread($self->{"fork_rd"}, $_, 16)) { |
f569508e |
1269 | # Socket closed, which means all children are done. |
1270 | return (); |
1271 | } |
1272 | my ($pid, $how) = split; |
1273 | if ($pid) { |
1274 | # Flush the zombie |
1275 | waitpid($pid, 0); |
1276 | if (my $entry = $self->{"syn"}->{$pid}) { |
1277 | # Connection attempt to remote host is done |
1278 | delete $self->{"syn"}->{$pid}; |
1279 | if (!$how || # If there was no error connecting |
c94ff782 |
1280 | (!$self->{"econnrefused"} && |
f569508e |
1281 | $how == ECONNREFUSED)) { # "Connection refused" means reachable |
69c74a9c |
1282 | if ($host && $entry->[0] ne $host) { |
1283 | # A good connection, but not the host we need. |
1284 | # Move it from the "syn" hash to the "good" hash. |
1285 | $self->{"good"}->{$entry->[0]} = $entry; |
1286 | # And wait for the next winner |
1287 | next; |
1288 | } |
f569508e |
1289 | return ($entry->[0], &time() - $entry->[3], inet_ntoa($entry->[1])); |
1290 | } |
1291 | } else { |
1292 | # Should never happen |
1293 | die "Unknown ping from pid [$pid]"; |
1294 | } |
1295 | } else { |
1296 | die "Empty response from status socket?"; |
1297 | } |
69c74a9c |
1298 | } |
1299 | if (defined $nfound) { |
f569508e |
1300 | # Timed out waiting for ACK status |
1301 | } else { |
1302 | # Weird error occurred with select() |
1303 | warn("select: $!"); |
1304 | } |
1305 | } |
1306 | if (my @synners = keys %{ $self->{"syn"} }) { |
1307 | # Kill all the synners |
1308 | kill 9, @synners; |
1309 | foreach my $pid (@synners) { |
1310 | # Wait for the deaths to finish |
1311 | # Then flush off the zombie |
1312 | waitpid($pid, 0); |
1313 | } |
1314 | } |
1315 | $self->{"syn"} = {}; |
1316 | return (); |
1317 | } |
1318 | |
1319 | # Description: Tell why the ack() failed |
1320 | sub nack { |
1321 | my $self = shift; |
1322 | my $host = shift || croak('Usage> nack($failed_ack_host)'); |
1323 | return $self->{"bad"}->{$host} || undef; |
1324 | } |
1325 | |
1326 | # Description: Close the connection. |
a3b93737 |
1327 | |
1328 | sub close |
1329 | { |
e82f584b |
1330 | my ($self) = @_; |
a3b93737 |
1331 | |
f569508e |
1332 | if ($self->{"proto"} eq "syn") { |
1333 | delete $self->{"syn"}; |
1334 | } elsif ($self->{"proto"} eq "tcp") { |
1335 | # The connection will already be closed |
1336 | } else { |
1337 | $self->{"fh"}->close(); |
1338 | } |
a3b93737 |
1339 | } |
1340 | |
1341 | |
a0d0e21e |
1342 | 1; |
8e07c86e |
1343 | __END__ |
1344 | |
8e07c86e |
1345 | =head1 NAME |
1346 | |
a3b93737 |
1347 | Net::Ping - check a remote host for reachability |
8e07c86e |
1348 | |
1349 | =head1 SYNOPSIS |
1350 | |
1351 | use Net::Ping; |
8e07c86e |
1352 | |
a3b93737 |
1353 | $p = Net::Ping->new(); |
1354 | print "$host is alive.\n" if $p->ping($host); |
1355 | $p->close(); |
1356 | |
1357 | $p = Net::Ping->new("icmp"); |
49afa5f6 |
1358 | $p->bind($my_addr); # Specify source interface of pings |
a3b93737 |
1359 | foreach $host (@host_array) |
1360 | { |
1361 | print "$host is "; |
1362 | print "NOT " unless $p->ping($host, 2); |
1363 | print "reachable.\n"; |
1364 | sleep(1); |
1365 | } |
1366 | $p->close(); |
b124990b |
1367 | |
a3b93737 |
1368 | $p = Net::Ping->new("tcp", 2); |
b124990b |
1369 | # Try connecting to the www port instead of the echo port |
1370 | $p->{port_num} = getservbyname("http", "tcp"); |
a3b93737 |
1371 | while ($stop_time > time()) |
1372 | { |
1373 | print "$host not reachable ", scalar(localtime()), "\n" |
1374 | unless $p->ping($host); |
1375 | sleep(300); |
1376 | } |
1377 | undef($p); |
b124990b |
1378 | |
f569508e |
1379 | # Like tcp protocol, but with many hosts |
1380 | $p = Net::Ping->new("syn"); |
1381 | $p->{port_num} = getservbyname("http", "tcp"); |
1382 | foreach $host (@host_array) { |
1383 | $p->ping($host); |
1384 | } |
1385 | while (($host,$rtt,$ip) = $p->ack) { |
1386 | print "HOST: $host [$ip] ACKed in $rtt seconds.\n"; |
1387 | } |
1388 | |
e82f584b |
1389 | # High precision syntax (requires Time::HiRes) |
1390 | $p = Net::Ping->new(); |
1391 | $p->hires(); |
1392 | ($ret, $duration, $ip) = $p->ping($host, 5.5); |
1393 | printf("$host [ip: $ip] is alive (packet return time: %.2f ms)\n", 1000 * $duration) |
1394 | if $ret; |
1395 | $p->close(); |
1396 | |
a3b93737 |
1397 | # For backward compatibility |
1398 | print "$host is alive.\n" if pingecho($host); |
8e07c86e |
1399 | |
a3b93737 |
1400 | =head1 DESCRIPTION |
8e07c86e |
1401 | |
a3b93737 |
1402 | This module contains methods to test the reachability of remote |
1403 | hosts on a network. A ping object is first created with optional |
1404 | parameters, a variable number of hosts may be pinged multiple |
1405 | times and then the connection is closed. |
1406 | |
f569508e |
1407 | You may choose one of six different protocols to use for the |
1408 | ping. The "tcp" protocol is the default. Note that a live remote host |
b124990b |
1409 | may still fail to be pingable by one or more of these protocols. For |
f569508e |
1410 | example, www.microsoft.com is generally alive but not "icmp" pingable. |
787ecdfa |
1411 | |
b124990b |
1412 | With the "tcp" protocol the ping() method attempts to establish a |
1413 | connection to the remote host's echo port. If the connection is |
1414 | successfully established, the remote host is considered reachable. No |
1415 | data is actually echoed. This protocol does not require any special |
9c36735d |
1416 | privileges but has higher overhead than the "udp" and "icmp" protocols. |
072620d9 |
1417 | |
b124990b |
1418 | Specifying the "udp" protocol causes the ping() method to send a udp |
a3b93737 |
1419 | packet to the remote host's echo port. If the echoed packet is |
1420 | received from the remote host and the received packet contains the |
1421 | same data as the packet that was sent, the remote host is considered |
1422 | reachable. This protocol does not require any special privileges. |
b124990b |
1423 | It should be borne in mind that, for a udp ping, a host |
787ecdfa |
1424 | will be reported as unreachable if it is not running the |
b124990b |
1425 | appropriate echo service. For Unix-like systems see L<inetd(8)> |
1426 | for more information. |
787ecdfa |
1427 | |
b124990b |
1428 | If the "icmp" protocol is specified, the ping() method sends an icmp |
1429 | echo message to the remote host, which is what the UNIX ping program |
1430 | does. If the echoed message is received from the remote host and |
1431 | the echoed information is correct, the remote host is considered |
1432 | reachable. Specifying the "icmp" protocol requires that the program |
1433 | be run as root or that the program be setuid to root. |
787ecdfa |
1434 | |
b124990b |
1435 | If the "external" protocol is specified, the ping() method attempts to |
1436 | use the C<Net::Ping::External> module to ping the remote host. |
1437 | C<Net::Ping::External> interfaces with your system's default C<ping> |
1438 | utility to perform the ping, and generally produces relatively |
787ecdfa |
1439 | accurate results. If C<Net::Ping::External> if not installed on your |
1440 | system, specifying the "external" protocol will result in an error. |
edc5bd88 |
1441 | |
f569508e |
1442 | If the "syn" protocol is specified, the ping() method will only |
1443 | send a TCP SYN packet to the remote host then immediately return. |
1444 | If the syn packet was sent successfully, it will return a true value, |
1445 | otherwise it will return false. NOTE: Unlike the other protocols, |
1446 | the return value does NOT determine if the remote host is alive or |
1447 | not since the full TCP three-way handshake may not have completed |
1448 | yet. The remote host is only considered reachable if it receives |
1449 | a TCP ACK within the timeout specifed. To begin waiting for the |
1450 | ACK packets, use the ack() method as explained below. Use the |
1451 | "syn" protocol instead the "tcp" protocol to determine reachability |
1452 | of multiple destinations simultaneously by sending parallel TCP |
1453 | SYN packets. It will not block while testing each remote host. |
1454 | demo/fping is provided in this distribution to demonstrate the |
1455 | "syn" protocol as an example. |
1456 | This protocol does not require any special privileges. |
1457 | |
a3b93737 |
1458 | =head2 Functions |
1459 | |
1460 | =over 4 |
1461 | |
f569508e |
1462 | =item Net::Ping->new([$proto [, $def_timeout [, $bytes [, $device ]]]]); |
a3b93737 |
1463 | |
1464 | Create a new ping object. All of the parameters are optional. $proto |
1465 | specifies the protocol to use when doing a ping. The current choices |
f569508e |
1466 | are "tcp", "udp", "icmp", "stream", "syn", or "external". |
1467 | The default is "tcp". |
a3b93737 |
1468 | |
1469 | If a default timeout ($def_timeout) in seconds is provided, it is used |
1470 | when a timeout is not given to the ping() method (below). The timeout |
1471 | must be greater than 0 and the default, if not specified, is 5 seconds. |
1472 | |
1473 | If the number of data bytes ($bytes) is given, that many data bytes |
1474 | are included in the ping packet sent to the remote host. The number of |
1475 | data bytes is ignored if the protocol is "tcp". The minimum (and |
1476 | default) number of data bytes is 1 if the protocol is "udp" and 0 |
1477 | otherwise. The maximum number of data bytes that can be specified is |
1478 | 1024. |
1479 | |
f569508e |
1480 | If $device is given, this device is used to bind the source endpoint |
1481 | before sending the ping packet. I beleive this only works with |
1482 | superuser privileges and with udp and icmp protocols at this time. |
1483 | |
5d20095f |
1484 | =item $p->ping($host [, $timeout]); |
1485 | |
1486 | Ping the remote host and wait for a response. $host can be either the |
1487 | hostname or the IP number of the remote host. The optional timeout |
1488 | must be greater than 0 seconds and defaults to whatever was specified |
1489 | when the ping object was created. Returns a success flag. If the |
1490 | hostname cannot be found or there is a problem with the IP number, the |
1491 | success flag returned will be undef. Otherwise, the success flag will |
1492 | be 1 if the host is reachable and 0 if it is not. For most practical |
1493 | purposes, undef and 0 and can be treated as the same case. In array |
f569508e |
1494 | context, the elapsed time as well as the string form of the ip the |
1495 | host resolved to are also returned. The elapsed time value will |
5d20095f |
1496 | be a float, as retuned by the Time::HiRes::time() function, if hires() |
1497 | has been previously called, otherwise it is returned as an integer. |
1498 | |
15d96390 |
1499 | =item $p->source_verify( { 0 | 1 } ); |
1500 | |
1501 | Allows source endpoint verification to be enabled or disabled. |
1502 | This is useful for those remote destinations with multiples |
1503 | interfaces where the response may not originate from the same |
1504 | endpoint that the original destination endpoint was sent to. |
5d20095f |
1505 | This only affects udp and icmp protocol pings. |
15d96390 |
1506 | |
1507 | This is enabled by default. |
1508 | |
c94ff782 |
1509 | =item $p->service_check( { 0 | 1 } ); |
f569508e |
1510 | |
c94ff782 |
1511 | Set whether or not the connect behavior should enforce |
f569508e |
1512 | remote service availability as well as reachability. Normally, |
1513 | if the remote server reported ECONNREFUSED, it must have been |
1514 | reachable because of the status packet that it reported. |
1515 | With this option enabled, the full three-way tcp handshake |
1516 | must have been established successfully before it will |
1517 | claim it is reachable. NOTE: It still does nothing more |
1518 | than connect and disconnect. It does not speak any protocol |
1519 | (i.e., HTTP or FTP) to ensure the remote server is sane in |
1520 | any way. The remote server CPU could be grinding to a halt |
1521 | and unresponsive to any clients connecting, but if the kernel |
1522 | throws the ACK packet, it is considered alive anyway. To |
1523 | really determine if the server is responding well would be |
1524 | application specific and is beyond the scope of Net::Ping. |
c94ff782 |
1525 | For udp protocol, enabling this option demands that the |
1526 | remote server replies with the same udp data that it was sent |
1527 | as defined by the udp echo service. |
f569508e |
1528 | |
c94ff782 |
1529 | This affects the "udp", "tcp", and "syn" protocols. |
f569508e |
1530 | |
1531 | This is disabled by default. |
1532 | |
c94ff782 |
1533 | =item $p->tcp_service_check( { 0 | 1 } ); |
1534 | |
1535 | Depricated method, but does the same as service_check() method. |
1536 | |
e82f584b |
1537 | =item $p->hires( { 0 | 1 } ); |
1538 | |
1539 | Causes this module to use Time::HiRes module, allowing milliseconds |
1540 | to be returned by subsequent calls to ping(). |
1541 | |
15d96390 |
1542 | This is disabled by default. |
1543 | |
49afa5f6 |
1544 | =item $p->bind($local_addr); |
1545 | |
1546 | Sets the source address from which pings will be sent. This must be |
1547 | the address of one of the interfaces on the local host. $local_addr |
1548 | may be specified as a hostname or as a text IP address such as |
1549 | "192.168.1.1". |
1550 | |
1551 | If the protocol is set to "tcp", this method may be called any |
1552 | number of times, and each call to the ping() method (below) will use |
1553 | the most recent $local_addr. If the protocol is "icmp" or "udp", |
1554 | then bind() must be called at most once per object, and (if it is |
1555 | called at all) must be called before the first call to ping() for that |
1556 | object. |
1557 | |
b124990b |
1558 | =item $p->open($host); |
1559 | |
f569508e |
1560 | When you are using the "stream" protocol, this call pre-opens the |
b124990b |
1561 | tcp socket. It's only necessary to do this if you want to |
1562 | provide a different timeout when creating the connection, or |
1563 | remove the overhead of establishing the connection from the |
1564 | first ping. If you don't call C<open()>, the connection is |
1565 | automatically opened the first time C<ping()> is called. |
787ecdfa |
1566 | This call simply does nothing if you are using any protocol other |
1567 | than stream. |
1568 | |
f569508e |
1569 | =item $p->ack( [ $host ] ); |
1570 | |
1571 | When using the "syn" protocol, use this method to determine |
1572 | the reachability of the remote host. This method is meant |
1573 | to be called up to as many times as ping() was called. Each |
1574 | call returns the host (as passed to ping()) that came back |
1575 | with the TCP ACK. The order in which the hosts are returned |
1576 | may not necessarily be the same order in which they were |
1577 | SYN queued using the ping() method. If the timeout is |
1578 | reached before the TCP ACK is received, or if the remote |
1579 | host is not listening on the port attempted, then the TCP |
1580 | connection will not be established and ack() will return |
1581 | undef. In list context, the host, the ack time, and the |
1582 | dotted ip string will be returned instead of just the host. |
1583 | If the optional $host argument is specified, the return |
1584 | value will be partaining to that host only. |
1585 | This call simply does nothing if you are using any protocol |
1586 | other than syn. |
1587 | |
1588 | =item $p->nack( $failed_ack_host ); |
1589 | |
1590 | The reason that host $failed_ack_host did not receive a |
1591 | valid ACK. Useful to find out why when ack( $fail_ack_host ) |
1592 | returns a false value. |
1593 | |
a3b93737 |
1594 | =item $p->close(); |
1595 | |
1596 | Close the network connection for this ping object. The network |
1597 | connection is also closed by "undef $p". The network connection is |
1598 | automatically closed if the ping object goes out of scope (e.g. $p is |
1599 | local to a subroutine and you leave the subroutine). |
1600 | |
1601 | =item pingecho($host [, $timeout]); |
1602 | |
1603 | To provide backward compatibility with the previous version of |
1604 | Net::Ping, a pingecho() subroutine is available with the same |
1605 | functionality as before. pingecho() uses the tcp protocol. The |
1606 | return values and parameters are the same as described for the ping() |
1607 | method. This subroutine is obsolete and may be removed in a future |
1608 | version of Net::Ping. |
8e07c86e |
1609 | |
a3b93737 |
1610 | =back |
8e07c86e |
1611 | |
a3b93737 |
1612 | =head1 NOTES |
8e07c86e |
1613 | |
a3b93737 |
1614 | There will be less network overhead (and some efficiency in your |
1615 | program) if you specify either the udp or the icmp protocol. The tcp |
1616 | protocol will generate 2.5 times or more traffic for each ping than |
1617 | either udp or icmp. If many hosts are pinged frequently, you may wish |
1618 | to implement a small wait (e.g. 25ms or more) between each ping to |
1619 | avoid flooding your network with packets. |
8e07c86e |
1620 | |
a3b93737 |
1621 | The icmp protocol requires that the program be run as root or that it |
787ecdfa |
1622 | be setuid to root. The other protocols do not require special |
1623 | privileges, but not all network devices implement tcp or udp echo. |
8e07c86e |
1624 | |
a3b93737 |
1625 | Local hosts should normally respond to pings within milliseconds. |
1626 | However, on a very congested network it may take up to 3 seconds or |
1627 | longer to receive an echo packet from the remote host. If the timeout |
1628 | is set too low under these conditions, it will appear that the remote |
1629 | host is not reachable (which is almost the truth). |
8e07c86e |
1630 | |
a3b93737 |
1631 | Reachability doesn't necessarily mean that the remote host is actually |
787ecdfa |
1632 | functioning beyond its ability to echo packets. tcp is slightly better |
1633 | at indicating the health of a system than icmp because it uses more |
1634 | of the networking stack to respond. |
8e07c86e |
1635 | |
a3b93737 |
1636 | Because of a lack of anything better, this module uses its own |
1637 | routines to pack and unpack ICMP packets. It would be better for a |
1638 | separate module to be written which understands all of the different |
1639 | kinds of ICMP packets. |
8e07c86e |
1640 | |
5d20095f |
1641 | =head1 INSTALL |
1642 | |
1643 | The latest source tree is available via cvs: |
1644 | |
f569508e |
1645 | cvs -z3 -q -d :pserver:anonymous@cvs.roobik.com.:/usr/local/cvsroot/freeware checkout Net-Ping |
5d20095f |
1646 | cd Net-Ping |
1647 | |
1648 | The tarball can be created as follows: |
1649 | |
1650 | perl Makefile.PL ; make ; make dist |
1651 | |
1652 | The latest Net::Ping release can be found at CPAN: |
1653 | |
1654 | $CPAN/modules/by-module/Net/ |
1655 | |
1656 | 1) Extract the tarball |
1657 | |
1658 | gtar -zxvf Net-Ping-xxxx.tar.gz |
1659 | cd Net-Ping-xxxx |
1660 | |
1661 | 2) Build: |
1662 | |
1663 | make realclean |
1664 | perl Makefile.PL |
1665 | make |
1666 | make test |
1667 | |
1668 | 3) Install |
1669 | |
1670 | make install |
1671 | |
1672 | Or install it RPM Style: |
1673 | |
1674 | rpm -ta SOURCES/Net-Ping-xxxx.tar.gz |
1675 | |
1676 | rpm -ih RPMS/noarch/perl-Net-Ping-xxxx.rpm |
1677 | |
c94ff782 |
1678 | =head1 BUGS |
1679 | |
1680 | For a list of known issues, visit: |
1681 | |
1682 | https://rt.cpan.org/NoAuth/Bugs.html?Dist=Net-Ping |
1683 | |
1684 | To report a new bug, visit: |
1685 | |
1686 | https://rt.cpan.org/NoAuth/ReportBug.html?Queue=Net-Ping |
1687 | |
49afa5f6 |
1688 | =head1 AUTHORS |
b124990b |
1689 | |
e82f584b |
1690 | Current maintainer: |
49afa5f6 |
1691 | bbb@cpan.org (Rob Brown) |
b124990b |
1692 | |
e82f584b |
1693 | External protocol: |
1694 | colinm@cpan.org (Colin McMillen) |
1695 | |
b124990b |
1696 | Stream protocol: |
1697 | bronson@trestle.com (Scott Bronson) |
1698 | |
1699 | Original pingecho(): |
1700 | karrer@bernina.ethz.ch (Andreas Karrer) |
1701 | pmarquess@bfsec.bt.co.uk (Paul Marquess) |
1702 | |
1703 | Original Net::Ping author: |
1704 | mose@ns.ccsn.edu (Russell Mosemann) |
1705 | |
b124990b |
1706 | =head1 COPYRIGHT |
1707 | |
9c36735d |
1708 | Copyright (c) 2002-2003, Rob Brown. All rights reserved. |
49afa5f6 |
1709 | |
e82f584b |
1710 | Copyright (c) 2001, Colin McMillen. All rights reserved. |
b124990b |
1711 | |
1712 | This program is free software; you may redistribute it and/or |
1713 | modify it under the same terms as Perl itself. |
1714 | |
9539e94f |
1715 | $Id: Ping.pm,v 1.81 2003/04/18 04:16:03 rob Exp $ |
c94ff782 |
1716 | |
a3b93737 |
1717 | =cut |