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); |
6084826d |
19 | $VERSION = "2.31_04"; |
03550e9d |
20 | |
21 | sub SOL_IP { 0; }; |
22 | sub IP_TOS { 1; }; |
a0d0e21e |
23 | |
a3b93737 |
24 | # Constants |
a0d0e21e |
25 | |
a3b93737 |
26 | $def_timeout = 5; # Default timeout to wait for a reply |
a5a165b1 |
27 | $def_proto = "tcp"; # Default protocol to use for pinging |
9539e94f |
28 | $def_factor = 1.2; # Default exponential backoff rate. |
a3b93737 |
29 | $max_datasize = 1024; # Maximum data bytes in a packet |
b124990b |
30 | # The data we exchange with the server for the stream protocol |
31 | $pingstring = "pingschwingping!\n"; |
5d20095f |
32 | $source_verify = 1; # Default is to verify source endpoint |
f569508e |
33 | $syn_forking = 0; |
a0d0e21e |
34 | |
ef73e1db |
35 | if ($^O =~ /Win32/i) { |
36 | # Hack to avoid this Win32 spewage: |
37 | # Your vendor has not defined POSIX macro ECONNREFUSED |
6084826d |
38 | *ECONNREFUSED = sub() {10061;}; # "Unknown Error" Special Win32 Response? |
39 | *ENOTCONN = sub() {10057;}; |
40 | *ECONNRESET = sub() {10054;}; |
41 | *EINPROGRESS = sub() {10036;}; |
42 | *EWOULDBLOCK = sub() {10035;}; |
eb194dd9 |
43 | # $syn_forking = 1; # XXX possibly useful in < Win2K ? |
ef73e1db |
44 | }; |
45 | |
f569508e |
46 | # h2ph "asm/socket.h" |
47 | # require "asm/socket.ph"; |
48 | sub SO_BINDTODEVICE {25;} |
49 | |
a3b93737 |
50 | # Description: The pingecho() subroutine is provided for backward |
51 | # compatibility with the original Net::Ping. It accepts a host |
52 | # name/IP and an optional timeout in seconds. Create a tcp ping |
53 | # object and try pinging the host. The result of the ping is returned. |
a0d0e21e |
54 | |
a3b93737 |
55 | sub pingecho |
56 | { |
e82f584b |
57 | my ($host, # Name or IP number of host to ping |
58 | $timeout # Optional timeout in seconds |
59 | ) = @_; |
60 | my ($p); # A ping object |
a0d0e21e |
61 | |
e82f584b |
62 | $p = Net::Ping->new("tcp", $timeout); |
63 | $p->ping($host); # Going out of scope closes the connection |
a3b93737 |
64 | } |
a0d0e21e |
65 | |
a3b93737 |
66 | # Description: The new() method creates a new ping object. Optional |
67 | # parameters may be specified for the protocol to use, the timeout in |
68 | # seconds and the size in bytes of additional data which should be |
69 | # included in the packet. |
70 | # After the optional parameters are checked, the data is constructed |
71 | # and a socket is opened if appropriate. The object is returned. |
72 | |
73 | sub new |
74 | { |
e82f584b |
75 | my ($this, |
76 | $proto, # Optional protocol to use for pinging |
77 | $timeout, # Optional timeout in seconds |
f569508e |
78 | $data_size, # Optional additional bytes of data |
79 | $device, # Optional device to use |
03550e9d |
80 | $tos, # Optional ToS to set |
e82f584b |
81 | ) = @_; |
82 | my $class = ref($this) || $this; |
83 | my $self = {}; |
84 | my ($cnt, # Count through data bytes |
85 | $min_datasize # Minimum data bytes required |
86 | ); |
87 | |
88 | bless($self, $class); |
89 | |
90 | $proto = $def_proto unless $proto; # Determine the protocol |
f569508e |
91 | croak('Protocol for ping must be "icmp", "udp", "tcp", "syn", "stream", or "external"') |
92 | unless $proto =~ m/^(icmp|udp|tcp|syn|stream|external)$/; |
e82f584b |
93 | $self->{"proto"} = $proto; |
94 | |
95 | $timeout = $def_timeout unless $timeout; # Determine the timeout |
96 | croak("Default timeout for ping must be greater than 0 seconds") |
97 | if $timeout <= 0; |
98 | $self->{"timeout"} = $timeout; |
99 | |
f569508e |
100 | $self->{"device"} = $device; |
101 | |
03550e9d |
102 | $self->{"tos"} = $tos; |
103 | |
e82f584b |
104 | $min_datasize = ($proto eq "udp") ? 1 : 0; # Determine data size |
105 | $data_size = $min_datasize unless defined($data_size) && $proto ne "tcp"; |
106 | croak("Data for ping must be from $min_datasize to $max_datasize bytes") |
107 | if ($data_size < $min_datasize) || ($data_size > $max_datasize); |
108 | $data_size-- if $self->{"proto"} eq "udp"; # We provide the first byte |
109 | $self->{"data_size"} = $data_size; |
110 | |
111 | $self->{"data"} = ""; # Construct data bytes |
112 | for ($cnt = 0; $cnt < $self->{"data_size"}; $cnt++) |
113 | { |
114 | $self->{"data"} .= chr($cnt % 256); |
115 | } |
116 | |
117 | $self->{"local_addr"} = undef; # Don't bind by default |
9539e94f |
118 | $self->{"retrans"} = $def_factor; # Default exponential backoff rate |
c94ff782 |
119 | $self->{"econnrefused"} = undef; # Default Connection refused behavior |
f569508e |
120 | |
e82f584b |
121 | $self->{"seq"} = 0; # For counting packets |
122 | if ($self->{"proto"} eq "udp") # Open a socket |
123 | { |
124 | $self->{"proto_num"} = (getprotobyname('udp'))[2] || |
125 | croak("Can't udp protocol by name"); |
126 | $self->{"port_num"} = (getservbyname('echo', 'udp'))[2] || |
127 | croak("Can't get udp echo port by name"); |
128 | $self->{"fh"} = FileHandle->new(); |
129 | socket($self->{"fh"}, PF_INET, SOCK_DGRAM, |
130 | $self->{"proto_num"}) || |
131 | croak("udp socket error - $!"); |
f569508e |
132 | if ($self->{'device'}) { |
133 | setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) |
134 | or croak "error binding to device $self->{'device'} $!"; |
135 | } |
03550e9d |
136 | if ($self->{'tos'}) { |
137 | setsockopt($self->{"fh"}, SOL_IP, IP_TOS(), pack("I*", $self->{'tos'})) |
138 | or croak "error configuring tos to $self->{'tos'} $!"; |
139 | } |
e82f584b |
140 | } |
141 | elsif ($self->{"proto"} eq "icmp") |
142 | { |
f569508e |
143 | croak("icmp ping requires root privilege") if ($> and $^O ne 'VMS' and $^O ne 'cygwin'); |
e82f584b |
144 | $self->{"proto_num"} = (getprotobyname('icmp'))[2] || |
145 | croak("Can't get icmp protocol by name"); |
146 | $self->{"pid"} = $$ & 0xffff; # Save lower 16 bits of pid |
147 | $self->{"fh"} = FileHandle->new(); |
148 | socket($self->{"fh"}, PF_INET, SOCK_RAW, $self->{"proto_num"}) || |
149 | croak("icmp socket error - $!"); |
f569508e |
150 | if ($self->{'device'}) { |
151 | setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) |
152 | or croak "error binding to device $self->{'device'} $!"; |
153 | } |
03550e9d |
154 | if ($self->{'tos'}) { |
155 | setsockopt($self->{"fh"}, SOL_IP, IP_TOS(), pack("I*", $self->{'tos'})) |
156 | or croak "error configuring tos to $self->{'tos'} $!"; |
157 | } |
e82f584b |
158 | } |
159 | elsif ($self->{"proto"} eq "tcp" || $self->{"proto"} eq "stream") |
160 | { |
161 | $self->{"proto_num"} = (getprotobyname('tcp'))[2] || |
162 | croak("Can't get tcp protocol by name"); |
163 | $self->{"port_num"} = (getservbyname('echo', 'tcp'))[2] || |
164 | croak("Can't get tcp echo port by name"); |
165 | $self->{"fh"} = FileHandle->new(); |
166 | } |
f569508e |
167 | elsif ($self->{"proto"} eq "syn") |
168 | { |
169 | $self->{"proto_num"} = (getprotobyname('tcp'))[2] || |
170 | croak("Can't get tcp protocol by name"); |
171 | $self->{"port_num"} = (getservbyname('echo', 'tcp'))[2] || |
172 | croak("Can't get tcp echo port by name"); |
173 | if ($syn_forking) { |
174 | $self->{"fork_rd"} = FileHandle->new(); |
175 | $self->{"fork_wr"} = FileHandle->new(); |
176 | pipe($self->{"fork_rd"}, $self->{"fork_wr"}); |
177 | $self->{"fh"} = FileHandle->new(); |
69c74a9c |
178 | $self->{"good"} = {}; |
179 | $self->{"bad"} = {}; |
f569508e |
180 | } else { |
181 | $self->{"wbits"} = ""; |
182 | $self->{"bad"} = {}; |
183 | } |
184 | $self->{"syn"} = {}; |
185 | $self->{"stop_time"} = 0; |
186 | } |
187 | elsif ($self->{"proto"} eq "external") |
188 | { |
189 | # No preliminary work needs to be done. |
190 | } |
e82f584b |
191 | |
192 | return($self); |
a3b93737 |
193 | } |
a0d0e21e |
194 | |
49afa5f6 |
195 | # Description: Set the local IP address from which pings will be sent. |
196 | # For ICMP and UDP pings, this calls bind() on the already-opened socket; |
197 | # for TCP pings, just saves the address to be used when the socket is |
198 | # opened. Returns non-zero if successful; croaks on error. |
199 | sub bind |
200 | { |
e82f584b |
201 | my ($self, |
202 | $local_addr # Name or IP number of local interface |
203 | ) = @_; |
204 | my ($ip # Packed IP number of $local_addr |
205 | ); |
206 | |
207 | croak("Usage: \$p->bind(\$local_addr)") unless @_ == 2; |
208 | croak("already bound") if defined($self->{"local_addr"}) && |
209 | ($self->{"proto"} eq "udp" || $self->{"proto"} eq "icmp"); |
210 | |
211 | $ip = inet_aton($local_addr); |
212 | croak("nonexistent local address $local_addr") unless defined($ip); |
213 | $self->{"local_addr"} = $ip; # Only used if proto is tcp |
214 | |
215 | if ($self->{"proto"} eq "udp" || $self->{"proto"} eq "icmp") |
216 | { |
217 | CORE::bind($self->{"fh"}, sockaddr_in(0, $ip)) || |
218 | croak("$self->{'proto'} bind error - $!"); |
219 | } |
03550e9d |
220 | elsif (($self->{"proto"} ne "tcp") && ($self->{"proto"} ne "syn")) |
e82f584b |
221 | { |
222 | croak("Unknown protocol \"$self->{proto}\" in bind()"); |
223 | } |
224 | |
225 | return 1; |
226 | } |
49afa5f6 |
227 | |
eb194dd9 |
228 | # Description: A select() wrapper that compensates for platform |
229 | # peculiarities. |
230 | sub mselect |
231 | { |
232 | if ($_[3] > 0 and $^O eq 'MSWin32') { |
233 | # On windows, select() doesn't process the message loop, |
234 | # but sleep() will, allowing alarm() to interrupt the latter. |
235 | # So we chop up the timeout into smaller pieces and interleave |
236 | # select() and sleep() calls. |
237 | my $t = $_[3]; |
238 | my $gran = 0.5; # polling granularity in seconds |
239 | my @args = @_; |
240 | while (1) { |
241 | $gran = $t if $gran > $t; |
242 | my $nfound = select($_[0], $_[1], $_[2], $gran); |
95d3daf0 |
243 | undef $nfound if $nfound == -1; |
eb194dd9 |
244 | $t -= $gran; |
245 | return $nfound if $nfound or !defined($nfound) or $t <= 0; |
246 | |
247 | sleep(0); |
248 | ($_[0], $_[1], $_[2]) = @args; |
249 | } |
250 | } |
251 | else { |
95d3daf0 |
252 | my $nfound = select($_[0], $_[1], $_[2], $_[3]); |
253 | undef $nfound if $nfound == -1; |
254 | return $nfound; |
eb194dd9 |
255 | } |
256 | } |
49afa5f6 |
257 | |
3c4b39be |
258 | # Description: Allow UDP source endpoint comparison to be |
15d96390 |
259 | # skipped for those remote interfaces that do |
260 | # not response from the same endpoint. |
261 | |
262 | sub source_verify |
263 | { |
264 | my $self = shift; |
5d20095f |
265 | $source_verify = 1 unless defined |
266 | ($source_verify = ((defined $self) && (ref $self)) ? shift() : $self); |
15d96390 |
267 | } |
268 | |
c94ff782 |
269 | # Description: Set whether or not the connect |
270 | # behavior should enforce remote service |
271 | # availability as well as reachability. |
f569508e |
272 | |
c94ff782 |
273 | sub service_check |
f569508e |
274 | { |
275 | my $self = shift; |
c94ff782 |
276 | $self->{"econnrefused"} = 1 unless defined |
277 | ($self->{"econnrefused"} = shift()); |
278 | } |
279 | |
280 | sub tcp_service_check |
281 | { |
282 | service_check(@_); |
f569508e |
283 | } |
284 | |
9539e94f |
285 | # Description: Set exponential backoff for retransmission. |
286 | # Should be > 1 to retain exponential properties. |
287 | # If set to 0, retransmissions are disabled. |
288 | |
289 | sub retrans |
290 | { |
291 | my $self = shift; |
292 | $self->{"retrans"} = shift; |
293 | } |
294 | |
e82f584b |
295 | # Description: allows the module to use milliseconds as returned by |
296 | # the Time::HiRes module |
49afa5f6 |
297 | |
e82f584b |
298 | $hires = 0; |
299 | sub hires |
300 | { |
301 | my $self = shift; |
302 | $hires = 1 unless defined |
303 | ($hires = ((defined $self) && (ref $self)) ? shift() : $self); |
304 | require Time::HiRes if $hires; |
49afa5f6 |
305 | } |
306 | |
e82f584b |
307 | sub time |
308 | { |
309 | return $hires ? Time::HiRes::time() : CORE::time(); |
310 | } |
49afa5f6 |
311 | |
9c36735d |
312 | # Description: Sets or clears the O_NONBLOCK flag on a file handle. |
313 | sub socket_blocking_mode |
314 | { |
315 | my ($self, |
316 | $fh, # the file handle whose flags are to be modified |
317 | $block) = @_; # if true then set the blocking |
318 | # mode (clear O_NONBLOCK), otherwise |
319 | # set the non-blocking mode (set O_NONBLOCK) |
320 | |
321 | my $flags; |
d135e082 |
322 | if ($^O eq 'MSWin32' || $^O eq 'VMS') { |
323 | # FIONBIO enables non-blocking sockets on windows and vms. |
324 | # FIONBIO is (0x80000000|(4<<16)|(ord('f')<<8)|126), as per winsock.h, ioctl.h |
eb194dd9 |
325 | my $f = 0x8004667e; |
326 | my $v = pack("L", $block ? 0 : 1); |
327 | ioctl($fh, $f, $v) or croak("ioctl failed: $!"); |
328 | return; |
329 | } |
9c36735d |
330 | if ($flags = fcntl($fh, F_GETFL, 0)) { |
331 | $flags = $block ? ($flags & ~O_NONBLOCK) : ($flags | O_NONBLOCK); |
332 | if (!fcntl($fh, F_SETFL, $flags)) { |
333 | croak("fcntl F_SETFL: $!"); |
334 | } |
335 | } else { |
336 | croak("fcntl F_GETFL: $!"); |
337 | } |
338 | } |
339 | |
a3b93737 |
340 | # Description: Ping a host name or IP number with an optional timeout. |
341 | # First lookup the host, and return undef if it is not found. Otherwise |
b124990b |
342 | # perform the specific ping method based on the protocol. Return the |
a3b93737 |
343 | # result of the ping. |
344 | |
345 | sub ping |
346 | { |
e82f584b |
347 | my ($self, |
348 | $host, # Name or IP number of host to ping |
349 | $timeout, # Seconds after which ping times out |
350 | ) = @_; |
351 | my ($ip, # Packed IP number of $host |
352 | $ret, # The return value |
353 | $ping_time, # When ping began |
354 | ); |
355 | |
356 | croak("Usage: \$p->ping(\$host [, \$timeout])") unless @_ == 2 || @_ == 3; |
357 | $timeout = $self->{"timeout"} unless $timeout; |
358 | croak("Timeout must be greater than 0 seconds") if $timeout <= 0; |
359 | |
360 | $ip = inet_aton($host); |
c94ff782 |
361 | return () unless defined($ip); # Does host exist? |
e82f584b |
362 | |
363 | # Dispatch to the appropriate routine. |
364 | $ping_time = &time(); |
365 | if ($self->{"proto"} eq "external") { |
366 | $ret = $self->ping_external($ip, $timeout); |
367 | } |
368 | elsif ($self->{"proto"} eq "udp") { |
369 | $ret = $self->ping_udp($ip, $timeout); |
370 | } |
371 | elsif ($self->{"proto"} eq "icmp") { |
372 | $ret = $self->ping_icmp($ip, $timeout); |
373 | } |
374 | elsif ($self->{"proto"} eq "tcp") { |
375 | $ret = $self->ping_tcp($ip, $timeout); |
376 | } |
377 | elsif ($self->{"proto"} eq "stream") { |
378 | $ret = $self->ping_stream($ip, $timeout); |
f569508e |
379 | } |
380 | elsif ($self->{"proto"} eq "syn") { |
381 | $ret = $self->ping_syn($host, $ip, $ping_time, $ping_time+$timeout); |
e82f584b |
382 | } else { |
787ecdfa |
383 | croak("Unknown protocol \"$self->{proto}\" in ping()"); |
e82f584b |
384 | } |
385 | |
386 | return wantarray ? ($ret, &time() - $ping_time, inet_ntoa($ip)) : $ret; |
787ecdfa |
387 | } |
388 | |
389 | # Uses Net::Ping::External to do an external ping. |
390 | sub ping_external { |
391 | my ($self, |
392 | $ip, # Packed IP number of the host |
393 | $timeout # Seconds after which ping times out |
394 | ) = @_; |
395 | |
b124990b |
396 | eval { require Net::Ping::External; } |
397 | or croak('Protocol "external" not supported on your system: Net::Ping::External not found'); |
787ecdfa |
398 | return Net::Ping::External::ping(ip => $ip, timeout => $timeout); |
a3b93737 |
399 | } |
a0d0e21e |
400 | |
46b9c7d8 |
401 | use constant ICMP_ECHOREPLY => 0; # ICMP packet types |
402 | use constant ICMP_UNREACHABLE => 3; # ICMP packet types |
403 | use constant ICMP_ECHO => 8; |
404 | use constant ICMP_STRUCT => "C2 n3 A"; # Structure of a minimal ICMP packet |
405 | use constant SUBCODE => 0; # No ICMP subcode for ECHO and ECHOREPLY |
406 | use constant ICMP_FLAGS => 0; # No special flags for send or recv |
407 | use constant ICMP_PORT => 0; # No port with ICMP |
49afa5f6 |
408 | |
a3b93737 |
409 | sub ping_icmp |
410 | { |
e82f584b |
411 | my ($self, |
412 | $ip, # Packed IP number of the host |
413 | $timeout # Seconds after which ping times out |
414 | ) = @_; |
415 | |
416 | my ($saddr, # sockaddr_in with port and ip |
417 | $checksum, # Checksum of ICMP packet |
418 | $msg, # ICMP packet to send |
419 | $len_msg, # Length of $msg |
420 | $rbits, # Read bits, filehandles for reading |
421 | $nfound, # Number of ready filehandles found |
422 | $finish_time, # Time ping should be finished |
423 | $done, # set to 1 when we are done |
424 | $ret, # Return value |
425 | $recv_msg, # Received message including IP header |
426 | $from_saddr, # sockaddr_in of sender |
427 | $from_port, # Port packet was sent from |
428 | $from_ip, # Packed IP of sender |
429 | $from_type, # ICMP type |
430 | $from_subcode, # ICMP subcode |
431 | $from_chk, # ICMP packet checksum |
432 | $from_pid, # ICMP packet id |
433 | $from_seq, # ICMP packet sequence |
434 | $from_msg # ICMP message |
435 | ); |
436 | |
437 | $self->{"seq"} = ($self->{"seq"} + 1) % 65536; # Increment sequence |
438 | $checksum = 0; # No checksum for starters |
439 | $msg = pack(ICMP_STRUCT . $self->{"data_size"}, ICMP_ECHO, SUBCODE, |
440 | $checksum, $self->{"pid"}, $self->{"seq"}, $self->{"data"}); |
441 | $checksum = Net::Ping->checksum($msg); |
442 | $msg = pack(ICMP_STRUCT . $self->{"data_size"}, ICMP_ECHO, SUBCODE, |
443 | $checksum, $self->{"pid"}, $self->{"seq"}, $self->{"data"}); |
444 | $len_msg = length($msg); |
445 | $saddr = sockaddr_in(ICMP_PORT, $ip); |
9c36735d |
446 | $self->{"from_ip"} = undef; |
447 | $self->{"from_type"} = undef; |
448 | $self->{"from_subcode"} = undef; |
e82f584b |
449 | send($self->{"fh"}, $msg, ICMP_FLAGS, $saddr); # Send the message |
450 | |
451 | $rbits = ""; |
452 | vec($rbits, $self->{"fh"}->fileno(), 1) = 1; |
453 | $ret = 0; |
454 | $done = 0; |
455 | $finish_time = &time() + $timeout; # Must be done by this time |
456 | while (!$done && $timeout > 0) # Keep trying if we have time |
457 | { |
eb194dd9 |
458 | $nfound = mselect((my $rout=$rbits), undef, undef, $timeout); # Wait for packet |
e82f584b |
459 | $timeout = $finish_time - &time(); # Get remaining time |
95d3daf0 |
460 | if (!defined($nfound)) # Hmm, a strange error |
a3b93737 |
461 | { |
e82f584b |
462 | $ret = undef; |
463 | $done = 1; |
464 | } |
465 | elsif ($nfound) # Got a packet from somewhere |
466 | { |
467 | $recv_msg = ""; |
9539e94f |
468 | $from_pid = -1; |
469 | $from_seq = -1; |
e82f584b |
470 | $from_saddr = recv($self->{"fh"}, $recv_msg, 1500, ICMP_FLAGS); |
471 | ($from_port, $from_ip) = sockaddr_in($from_saddr); |
9c36735d |
472 | ($from_type, $from_subcode) = unpack("C2", substr($recv_msg, 20, 2)); |
9539e94f |
473 | if ($from_type == ICMP_ECHOREPLY) { |
474 | ($from_pid, $from_seq) = unpack("n3", substr($recv_msg, 24, 4)) |
475 | if length $recv_msg >= 28; |
9c36735d |
476 | } else { |
9539e94f |
477 | ($from_pid, $from_seq) = unpack("n3", substr($recv_msg, 52, 4)) |
478 | if length $recv_msg >= 56; |
9c36735d |
479 | } |
480 | $self->{"from_ip"} = $from_ip; |
481 | $self->{"from_type"} = $from_type; |
482 | $self->{"from_subcode"} = $from_subcode; |
483 | if (($from_pid == $self->{"pid"}) && # Does the packet check out? |
484 | ($from_seq == $self->{"seq"})) { |
46b9c7d8 |
485 | if ($from_type == ICMP_ECHOREPLY) { |
9c36735d |
486 | $ret = 1; |
46b9c7d8 |
487 | $done = 1; |
488 | } elsif ($from_type == ICMP_UNREACHABLE) { |
489 | $done = 1; |
9c36735d |
490 | } |
e82f584b |
491 | } |
9c36735d |
492 | } else { # Oops, timed out |
e82f584b |
493 | $done = 1; |
494 | } |
495 | } |
496 | return $ret; |
a3b93737 |
497 | } |
498 | |
9c36735d |
499 | sub icmp_result { |
500 | my ($self) = @_; |
501 | my $ip = $self->{"from_ip"} || ""; |
502 | $ip = "\0\0\0\0" unless 4 == length $ip; |
503 | return (inet_ntoa($ip),($self->{"from_type"} || 0), ($self->{"from_subcode"} || 0)); |
504 | } |
505 | |
a3b93737 |
506 | # Description: Do a checksum on the message. Basically sum all of |
507 | # the short words and fold the high order bits into the low order bits. |
508 | |
509 | sub checksum |
510 | { |
e82f584b |
511 | my ($class, |
512 | $msg # The message to checksum |
513 | ) = @_; |
514 | my ($len_msg, # Length of the message |
515 | $num_short, # The number of short words in the message |
516 | $short, # One short word |
517 | $chk # The checksum |
518 | ); |
519 | |
520 | $len_msg = length($msg); |
521 | $num_short = int($len_msg / 2); |
522 | $chk = 0; |
9c36735d |
523 | foreach $short (unpack("n$num_short", $msg)) |
e82f584b |
524 | { |
525 | $chk += $short; |
526 | } # Add the odd byte in |
527 | $chk += (unpack("C", substr($msg, $len_msg - 1, 1)) << 8) if $len_msg % 2; |
528 | $chk = ($chk >> 16) + ($chk & 0xffff); # Fold high into low |
529 | return(~(($chk >> 16) + $chk) & 0xffff); # Again and complement |
a3b93737 |
530 | } |
531 | |
787ecdfa |
532 | |
b124990b |
533 | # Description: Perform a tcp echo ping. Since a tcp connection is |
534 | # host specific, we have to open and close each connection here. We |
535 | # can't just leave a socket open. Because of the robust nature of |
536 | # tcp, it will take a while before it gives up trying to establish a |
537 | # connection. Therefore, we use select() on a non-blocking socket to |
538 | # check against our timeout. No data bytes are actually |
539 | # sent since the successful establishment of a connection is proof |
540 | # enough of the reachability of the remote host. Also, tcp is |
541 | # expensive and doesn't need our help to add to the overhead. |
542 | |
543 | sub ping_tcp |
787ecdfa |
544 | { |
e82f584b |
545 | my ($self, |
546 | $ip, # Packed IP number of the host |
547 | $timeout # Seconds after which ping times out |
548 | ) = @_; |
549 | my ($ret # The return value |
550 | ); |
551 | |
9c36735d |
552 | $! = 0; |
e82f584b |
553 | $ret = $self -> tcp_connect( $ip, $timeout); |
c94ff782 |
554 | if (!$self->{"econnrefused"} && |
f569508e |
555 | $! == ECONNREFUSED) { |
556 | $ret = 1; # "Connection refused" means reachable |
557 | } |
e82f584b |
558 | $self->{"fh"}->close(); |
559 | return $ret; |
787ecdfa |
560 | } |
561 | |
b124990b |
562 | sub tcp_connect |
787ecdfa |
563 | { |
e82f584b |
564 | my ($self, |
565 | $ip, # Packed IP number of the host |
566 | $timeout # Seconds after which connect times out |
567 | ) = @_; |
568 | my ($saddr); # Packed IP and Port |
b124990b |
569 | |
e82f584b |
570 | $saddr = sockaddr_in($self->{"port_num"}, $ip); |
b124990b |
571 | |
e82f584b |
572 | my $ret = 0; # Default to unreachable |
b124990b |
573 | |
e82f584b |
574 | my $do_socket = sub { |
575 | socket($self->{"fh"}, PF_INET, SOCK_STREAM, $self->{"proto_num"}) || |
576 | croak("tcp socket error - $!"); |
577 | if (defined $self->{"local_addr"} && |
578 | !CORE::bind($self->{"fh"}, sockaddr_in(0, $self->{"local_addr"}))) { |
579 | croak("tcp bind error - $!"); |
580 | } |
f569508e |
581 | if ($self->{'device'}) { |
582 | setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) |
583 | or croak("error binding to device $self->{'device'} $!"); |
584 | } |
03550e9d |
585 | if ($self->{'tos'}) { |
586 | setsockopt($self->{"fh"}, SOL_IP, IP_TOS(), pack("I*", $self->{'tos'})) |
587 | or croak "error configuring tos to $self->{'tos'} $!"; |
588 | } |
e82f584b |
589 | }; |
590 | my $do_connect = sub { |
9c36735d |
591 | $self->{"ip"} = $ip; |
6dbac12b |
592 | # ECONNREFUSED is 10061 on MSWin32. If we pass it as child error through $?, |
593 | # we'll get (10061 & 255) = 77, so we cannot check it in the parent process. |
594 | return ($ret = connect($self->{"fh"}, $saddr) || ($! == ECONNREFUSED && !$self->{"econnrefused"})); |
e82f584b |
595 | }; |
9c36735d |
596 | my $do_connect_nb = sub { |
597 | # Set O_NONBLOCK property on filehandle |
598 | $self->socket_blocking_mode($self->{"fh"}, 0); |
599 | |
600 | # start the connection attempt |
601 | if (!connect($self->{"fh"}, $saddr)) { |
602 | if ($! == ECONNREFUSED) { |
c94ff782 |
603 | $ret = 1 unless $self->{"econnrefused"}; |
eb194dd9 |
604 | } elsif ($! != EINPROGRESS && ($^O ne 'MSWin32' || $! != EWOULDBLOCK)) { |
9c36735d |
605 | # EINPROGRESS is the expected error code after a connect() |
c94ff782 |
606 | # on a non-blocking socket. But if the kernel immediately |
607 | # determined that this connect() will never work, |
608 | # Simply respond with "unreachable" status. |
609 | # (This can occur on some platforms with errno |
610 | # EHOSTUNREACH or ENETUNREACH.) |
611 | return 0; |
612 | } else { |
613 | # Got the expected EINPROGRESS. |
614 | # Just wait for connection completion... |
eb194dd9 |
615 | my ($wbits, $wout, $wexc); |
616 | $wout = $wexc = $wbits = ""; |
9c36735d |
617 | vec($wbits, $self->{"fh"}->fileno, 1) = 1; |
618 | |
eb194dd9 |
619 | my $nfound = mselect(undef, |
620 | ($wout = $wbits), |
621 | ($^O eq 'MSWin32' ? ($wexc = $wbits) : undef), |
622 | $timeout); |
9c36735d |
623 | warn("select: $!") unless defined $nfound; |
624 | |
625 | if ($nfound && vec($wout, $self->{"fh"}->fileno, 1)) { |
626 | # the socket is ready for writing so the connection |
627 | # attempt completed. test whether the connection |
628 | # attempt was successful or not |
629 | |
630 | if (getpeername($self->{"fh"})) { |
631 | # Connection established to remote host |
632 | $ret = 1; |
633 | } else { |
634 | # TCP ACK will never come from this host |
635 | # because there was an error connecting. |
e82f584b |
636 | |
9c36735d |
637 | # This should set $! to the correct error. |
638 | my $char; |
639 | sysread($self->{"fh"},$char,1); |
640 | $! = ECONNREFUSED if ($! == EAGAIN && $^O =~ /cygwin/i); |
e82f584b |
641 | |
c94ff782 |
642 | $ret = 1 if (!$self->{"econnrefused"} |
9c36735d |
643 | && $! == ECONNREFUSED); |
644 | } |
645 | } else { |
eb194dd9 |
646 | # the connection attempt timed out (or there were connect |
647 | # errors on Windows) |
648 | if ($^O =~ 'MSWin32') { |
649 | # If the connect will fail on a non-blocking socket, |
650 | # winsock reports ECONNREFUSED as an exception, and we |
651 | # need to fetch the socket-level error code via getsockopt() |
652 | # instead of using the thread-level error code that is in $!. |
653 | if ($nfound && vec($wexc, $self->{"fh"}->fileno, 1)) { |
654 | $! = unpack("i", getsockopt($self->{"fh"}, SOL_SOCKET, |
655 | SO_ERROR)); |
656 | } |
657 | } |
9c36735d |
658 | } |
659 | } |
660 | } else { |
661 | # Connection established to remote host |
662 | $ret = 1; |
663 | } |
664 | |
665 | # Unset O_NONBLOCK property on filehandle |
666 | $self->socket_blocking_mode($self->{"fh"}, 1); |
667 | $self->{"ip"} = $ip; |
668 | return $ret; |
669 | }; |
670 | |
671 | if ($syn_forking) { |
672 | # Buggy Winsock API doesn't allow nonblocking connect. |
e82f584b |
673 | # Hence, if our OS is Windows, we need to create a separate |
674 | # process to do the blocking connect attempt. |
eb194dd9 |
675 | # XXX Above comments are not true at least for Win2K, where |
676 | # nonblocking connect works. |
e82f584b |
677 | |
678 | $| = 1; # Clear buffer prior to fork to prevent duplicate flushing. |
9c36735d |
679 | $self->{'tcp_chld'} = fork; |
680 | if (!$self->{'tcp_chld'}) { |
681 | if (!defined $self->{'tcp_chld'}) { |
e82f584b |
682 | # Fork did not work |
9c36735d |
683 | warn "Fork error: $!"; |
e82f584b |
684 | return 0; |
b124990b |
685 | } |
b124990b |
686 | &{ $do_socket }(); |
687 | |
e82f584b |
688 | # Try a slow blocking connect() call |
9c36735d |
689 | # and report the status to the parent. |
e82f584b |
690 | if ( &{ $do_connect }() ) { |
691 | $self->{"fh"}->close(); |
692 | # No error |
693 | exit 0; |
b124990b |
694 | } else { |
e82f584b |
695 | # Pass the error status to the parent |
6dbac12b |
696 | # Make sure that $! <= 255 |
697 | exit($! <= 255 ? $! : 255); |
b124990b |
698 | } |
e82f584b |
699 | } |
b124990b |
700 | |
e82f584b |
701 | &{ $do_socket }(); |
702 | |
703 | my $patience = &time() + $timeout; |
704 | |
9c36735d |
705 | my ($child, $child_errno); |
706 | $? = 0; $child_errno = 0; |
e82f584b |
707 | # Wait up to the timeout |
708 | # And clean off the zombie |
709 | do { |
9c36735d |
710 | $child = waitpid($self->{'tcp_chld'}, &WNOHANG()); |
711 | $child_errno = $? >> 8; |
e82f584b |
712 | select(undef, undef, undef, 0.1); |
9c36735d |
713 | } while &time() < $patience && $child != $self->{'tcp_chld'}; |
714 | |
715 | if ($child == $self->{'tcp_chld'}) { |
716 | if ($self->{"proto"} eq "stream") { |
717 | # We need the socket connected here, in parent |
718 | # Should be safe to connect because the child finished |
719 | # within the timeout |
720 | &{ $do_connect }(); |
721 | } |
6dbac12b |
722 | # $ret cannot be set by the child process |
723 | $ret = !$child_errno; |
e82f584b |
724 | } else { |
725 | # Time must have run out. |
e82f584b |
726 | # Put that choking client out of its misery |
9c36735d |
727 | kill "KILL", $self->{'tcp_chld'}; |
e82f584b |
728 | # Clean off the zombie |
9c36735d |
729 | waitpid($self->{'tcp_chld'}, 0); |
e82f584b |
730 | $ret = 0; |
b124990b |
731 | } |
9c36735d |
732 | delete $self->{'tcp_chld'}; |
733 | $! = $child_errno; |
734 | } else { |
e82f584b |
735 | # Otherwise don't waste the resources to fork |
736 | |
737 | &{ $do_socket }(); |
738 | |
9c36735d |
739 | &{ $do_connect_nb }(); |
e82f584b |
740 | } |
787ecdfa |
741 | |
e82f584b |
742 | return $ret; |
787ecdfa |
743 | } |
744 | |
9c36735d |
745 | sub DESTROY { |
746 | my $self = shift; |
747 | if ($self->{'proto'} eq 'tcp' && |
748 | $self->{'tcp_chld'}) { |
749 | # Put that choking client out of its misery |
750 | kill "KILL", $self->{'tcp_chld'}; |
751 | # Clean off the zombie |
752 | waitpid($self->{'tcp_chld'}, 0); |
753 | } |
754 | } |
755 | |
787ecdfa |
756 | # This writes the given string to the socket and then reads it |
757 | # back. It returns 1 on success, 0 on failure. |
758 | sub tcp_echo |
759 | { |
e82f584b |
760 | my $self = shift; |
761 | my $timeout = shift; |
762 | my $pingstring = shift; |
763 | |
764 | my $ret = undef; |
765 | my $time = &time(); |
766 | my $wrstr = $pingstring; |
767 | my $rdstr = ""; |
768 | |
769 | eval <<'EOM'; |
770 | do { |
771 | my $rin = ""; |
772 | vec($rin, $self->{"fh"}->fileno(), 1) = 1; |
773 | |
774 | my $rout = undef; |
775 | if($wrstr) { |
776 | $rout = ""; |
777 | vec($rout, $self->{"fh"}->fileno(), 1) = 1; |
778 | } |
779 | |
eb194dd9 |
780 | if(mselect($rin, $rout, undef, ($time + $timeout) - &time())) { |
e82f584b |
781 | |
782 | if($rout && vec($rout,$self->{"fh"}->fileno(),1)) { |
9c36735d |
783 | my $num = syswrite($self->{"fh"}, $wrstr, length $wrstr); |
e82f584b |
784 | if($num) { |
785 | # If it was a partial write, update and try again. |
786 | $wrstr = substr($wrstr,$num); |
787 | } else { |
788 | # There was an error. |
789 | $ret = 0; |
790 | } |
791 | } |
792 | |
793 | if(vec($rin,$self->{"fh"}->fileno(),1)) { |
794 | my $reply; |
795 | if(sysread($self->{"fh"},$reply,length($pingstring)-length($rdstr))) { |
796 | $rdstr .= $reply; |
797 | $ret = 1 if $rdstr eq $pingstring; |
798 | } else { |
799 | # There was an error. |
800 | $ret = 0; |
801 | } |
802 | } |
803 | |
804 | } |
805 | } until &time() > ($time + $timeout) || defined($ret); |
787ecdfa |
806 | EOM |
807 | |
e82f584b |
808 | return $ret; |
787ecdfa |
809 | } |
810 | |
787ecdfa |
811 | |
787ecdfa |
812 | |
787ecdfa |
813 | |
814 | # Description: Perform a stream ping. If the tcp connection isn't |
815 | # already open, it opens it. It then sends some data and waits for |
816 | # a reply. It leaves the stream open on exit. |
817 | |
818 | sub ping_stream |
819 | { |
e82f584b |
820 | my ($self, |
821 | $ip, # Packed IP number of the host |
822 | $timeout # Seconds after which ping times out |
823 | ) = @_; |
072620d9 |
824 | |
e82f584b |
825 | # Open the stream if it's not already open |
826 | if(!defined $self->{"fh"}->fileno()) { |
827 | $self->tcp_connect($ip, $timeout) or return 0; |
828 | } |
787ecdfa |
829 | |
e82f584b |
830 | croak "tried to switch servers while stream pinging" |
831 | if $self->{"ip"} ne $ip; |
832 | |
833 | return $self->tcp_echo($timeout, $pingstring); |
787ecdfa |
834 | } |
835 | |
836 | # Description: opens the stream. You would do this if you want to |
837 | # separate the overhead of opening the stream from the first ping. |
838 | |
839 | sub open |
840 | { |
e82f584b |
841 | my ($self, |
842 | $host, # Host or IP address |
843 | $timeout # Seconds after which open times out |
844 | ) = @_; |
845 | |
846 | my ($ip); # Packed IP number of the host |
847 | $ip = inet_aton($host); |
848 | $timeout = $self->{"timeout"} unless $timeout; |
849 | |
850 | if($self->{"proto"} eq "stream") { |
851 | if(defined($self->{"fh"}->fileno())) { |
852 | croak("socket is already open"); |
853 | } else { |
854 | $self->tcp_connect($ip, $timeout); |
b124990b |
855 | } |
e82f584b |
856 | } |
072620d9 |
857 | } |
858 | |
b124990b |
859 | |
a3b93737 |
860 | # Description: Perform a udp echo ping. Construct a message of |
861 | # at least the one-byte sequence number and any additional data bytes. |
862 | # Send the message out and wait for a message to come back. If we |
863 | # get a message, make sure all of its parts match. If they do, we are |
864 | # done. Otherwise go back and wait for the message until we run out |
865 | # of time. Return the result of our efforts. |
866 | |
49afa5f6 |
867 | use constant UDP_FLAGS => 0; # Nothing special on send or recv |
a3b93737 |
868 | sub ping_udp |
869 | { |
e82f584b |
870 | my ($self, |
871 | $ip, # Packed IP number of the host |
872 | $timeout # Seconds after which ping times out |
873 | ) = @_; |
874 | |
875 | my ($saddr, # sockaddr_in with port and ip |
876 | $ret, # The return value |
877 | $msg, # Message to be echoed |
878 | $finish_time, # Time ping should be finished |
9539e94f |
879 | $flush, # Whether socket needs to be disconnected |
880 | $connect, # Whether socket needs to be connected |
e82f584b |
881 | $done, # Set to 1 when we are done pinging |
882 | $rbits, # Read bits, filehandles for reading |
883 | $nfound, # Number of ready filehandles found |
884 | $from_saddr, # sockaddr_in of sender |
885 | $from_msg, # Characters echoed by $host |
886 | $from_port, # Port message was echoed from |
887 | $from_ip # Packed IP number of sender |
888 | ); |
889 | |
890 | $saddr = sockaddr_in($self->{"port_num"}, $ip); |
891 | $self->{"seq"} = ($self->{"seq"} + 1) % 256; # Increment sequence |
892 | $msg = chr($self->{"seq"}) . $self->{"data"}; # Add data if any |
9539e94f |
893 | |
894 | if ($self->{"connected"}) { |
895 | if ($self->{"connected"} ne $saddr) { |
896 | # Still connected to wrong destination. |
897 | # Need to flush out the old one. |
898 | $flush = 1; |
899 | } |
900 | } else { |
901 | # Not connected yet. |
902 | # Need to connect() before send() |
903 | $connect = 1; |
904 | } |
905 | |
c94ff782 |
906 | # Have to connect() and send() instead of sendto() |
907 | # in order to pick up on the ECONNREFUSED setting |
908 | # from recv() or double send() errno as utilized in |
909 | # the concept by rdw @ perlmonks. See: |
910 | # http://perlmonks.thepen.com/42898.html |
9539e94f |
911 | if ($flush) { |
912 | # Need to socket() again to flush the descriptor |
913 | # This will disconnect from the old saddr. |
914 | socket($self->{"fh"}, PF_INET, SOCK_DGRAM, |
915 | $self->{"proto_num"}); |
916 | } |
917 | # Connect the socket if it isn't already connected |
918 | # to the right destination. |
919 | if ($flush || $connect) { |
920 | connect($self->{"fh"}, $saddr); # Tie destination to socket |
921 | $self->{"connected"} = $saddr; |
922 | } |
c94ff782 |
923 | send($self->{"fh"}, $msg, UDP_FLAGS); # Send it |
e82f584b |
924 | |
925 | $rbits = ""; |
926 | vec($rbits, $self->{"fh"}->fileno(), 1) = 1; |
927 | $ret = 0; # Default to unreachable |
928 | $done = 0; |
c94ff782 |
929 | my $retrans = 0.01; |
9539e94f |
930 | my $factor = $self->{"retrans"}; |
e82f584b |
931 | $finish_time = &time() + $timeout; # Ping needs to be done by then |
932 | while (!$done && $timeout > 0) |
933 | { |
9539e94f |
934 | if ($factor > 1) |
935 | { |
936 | $timeout = $retrans if $timeout > $retrans; |
937 | $retrans*= $factor; # Exponential backoff |
938 | } |
eb194dd9 |
939 | $nfound = mselect((my $rout=$rbits), undef, undef, $timeout); # Wait for response |
c94ff782 |
940 | my $why = $!; |
e82f584b |
941 | $timeout = $finish_time - &time(); # Get remaining time |
942 | |
943 | if (!defined($nfound)) # Hmm, a strange error |
a3b93737 |
944 | { |
e82f584b |
945 | $ret = undef; |
946 | $done = 1; |
a3b93737 |
947 | } |
e82f584b |
948 | elsif ($nfound) # A packet is waiting |
949 | { |
950 | $from_msg = ""; |
c94ff782 |
951 | $from_saddr = recv($self->{"fh"}, $from_msg, 1500, UDP_FLAGS); |
952 | if (!$from_saddr) { |
953 | # For example an unreachable host will make recv() fail. |
954 | if (!$self->{"econnrefused"} && |
9539e94f |
955 | ($! == ECONNREFUSED || |
956 | $! == ECONNRESET)) { |
c94ff782 |
957 | # "Connection refused" means reachable |
958 | # Good, continue |
959 | $ret = 1; |
960 | } |
e82f584b |
961 | $done = 1; |
c94ff782 |
962 | } else { |
963 | ($from_port, $from_ip) = sockaddr_in($from_saddr); |
964 | if (!$source_verify || |
965 | (($from_ip eq $ip) && # Does the packet check out? |
966 | ($from_port == $self->{"port_num"}) && |
967 | ($from_msg eq $msg))) |
968 | { |
969 | $ret = 1; # It's a winner |
970 | $done = 1; |
971 | } |
e82f584b |
972 | } |
973 | } |
c94ff782 |
974 | elsif ($timeout <= 0) # Oops, timed out |
e82f584b |
975 | { |
976 | $done = 1; |
977 | } |
c94ff782 |
978 | else |
979 | { |
980 | # Send another in case the last one dropped |
981 | if (send($self->{"fh"}, $msg, UDP_FLAGS)) { |
982 | # Another send worked? The previous udp packet |
983 | # must have gotten lost or is still in transit. |
984 | # Hopefully this new packet will arrive safely. |
985 | } else { |
986 | if (!$self->{"econnrefused"} && |
987 | $! == ECONNREFUSED) { |
988 | # "Connection refused" means reachable |
989 | # Good, continue |
990 | $ret = 1; |
991 | } |
992 | $done = 1; |
993 | } |
994 | } |
e82f584b |
995 | } |
a5a165b1 |
996 | return $ret; |
b124990b |
997 | } |
a0d0e21e |
998 | |
f569508e |
999 | # Description: Send a TCP SYN packet to host specified. |
1000 | sub ping_syn |
1001 | { |
1002 | my $self = shift; |
1003 | my $host = shift; |
1004 | my $ip = shift; |
1005 | my $start_time = shift; |
1006 | my $stop_time = shift; |
1007 | |
1008 | if ($syn_forking) { |
1009 | return $self->ping_syn_fork($host, $ip, $start_time, $stop_time); |
1010 | } |
1011 | |
1012 | my $fh = FileHandle->new(); |
1013 | my $saddr = sockaddr_in($self->{"port_num"}, $ip); |
1014 | |
1015 | # Create TCP socket |
1016 | if (!socket ($fh, PF_INET, SOCK_STREAM, $self->{"proto_num"})) { |
1017 | croak("tcp socket error - $!"); |
1018 | } |
1019 | |
1020 | if (defined $self->{"local_addr"} && |
1021 | !CORE::bind($fh, sockaddr_in(0, $self->{"local_addr"}))) { |
1022 | croak("tcp bind error - $!"); |
1023 | } |
1024 | |
1025 | if ($self->{'device'}) { |
1026 | setsockopt($fh, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) |
1027 | or croak("error binding to device $self->{'device'} $!"); |
1028 | } |
03550e9d |
1029 | if ($self->{'tos'}) { |
1030 | setsockopt($fh, SOL_IP, IP_TOS(), pack("I*", $self->{'tos'})) |
1031 | or croak "error configuring tos to $self->{'tos'} $!"; |
1032 | } |
f569508e |
1033 | # Set O_NONBLOCK property on filehandle |
9c36735d |
1034 | $self->socket_blocking_mode($fh, 0); |
f569508e |
1035 | |
1036 | # Attempt the non-blocking connect |
1037 | # by just sending the TCP SYN packet |
1038 | if (connect($fh, $saddr)) { |
1039 | # Non-blocking, yet still connected? |
69c74a9c |
1040 | # Must have connected very quickly, |
1041 | # or else it wasn't very non-blocking. |
1042 | #warn "WARNING: Nonblocking connect connected anyway? ($^O)"; |
1043 | } else { |
f569508e |
1044 | # Error occurred connecting. |
eb194dd9 |
1045 | if ($! == EINPROGRESS || ($^O eq 'MSWin32' && $! == EWOULDBLOCK)) { |
69c74a9c |
1046 | # The connection is just still in progress. |
1047 | # This is the expected condition. |
1048 | } else { |
1049 | # Just save the error and continue on. |
1050 | # The ack() can check the status later. |
f569508e |
1051 | $self->{"bad"}->{$host} = $!; |
f569508e |
1052 | } |
1053 | } |
1054 | |
1055 | my $entry = [ $host, $ip, $fh, $start_time, $stop_time ]; |
1056 | $self->{"syn"}->{$fh->fileno} = $entry; |
1057 | if ($self->{"stop_time"} < $stop_time) { |
1058 | $self->{"stop_time"} = $stop_time; |
1059 | } |
1060 | vec($self->{"wbits"}, $fh->fileno, 1) = 1; |
1061 | |
1062 | return 1; |
1063 | } |
1064 | |
1065 | sub ping_syn_fork { |
1066 | my ($self, $host, $ip, $start_time, $stop_time) = @_; |
1067 | |
1068 | # Buggy Winsock API doesn't allow nonblocking connect. |
1069 | # Hence, if our OS is Windows, we need to create a separate |
1070 | # process to do the blocking connect attempt. |
1071 | my $pid = fork(); |
1072 | if (defined $pid) { |
1073 | if ($pid) { |
1074 | # Parent process |
1075 | my $entry = [ $host, $ip, $pid, $start_time, $stop_time ]; |
1076 | $self->{"syn"}->{$pid} = $entry; |
1077 | if ($self->{"stop_time"} < $stop_time) { |
1078 | $self->{"stop_time"} = $stop_time; |
1079 | } |
1080 | } else { |
1081 | # Child process |
1082 | my $saddr = sockaddr_in($self->{"port_num"}, $ip); |
1083 | |
1084 | # Create TCP socket |
1085 | if (!socket ($self->{"fh"}, PF_INET, SOCK_STREAM, $self->{"proto_num"})) { |
1086 | croak("tcp socket error - $!"); |
1087 | } |
1088 | |
1089 | if (defined $self->{"local_addr"} && |
1090 | !CORE::bind($self->{"fh"}, sockaddr_in(0, $self->{"local_addr"}))) { |
1091 | croak("tcp bind error - $!"); |
1092 | } |
1093 | |
1094 | if ($self->{'device'}) { |
1095 | setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) |
1096 | or croak("error binding to device $self->{'device'} $!"); |
1097 | } |
03550e9d |
1098 | if ($self->{'tos'}) { |
1099 | setsockopt($self->{"fh"}, SOL_IP, IP_TOS(), pack("I*", $self->{'tos'})) |
1100 | or croak "error configuring tos to $self->{'tos'} $!"; |
1101 | } |
f569508e |
1102 | |
1103 | $!=0; |
1104 | # Try to connect (could take a long time) |
1105 | connect($self->{"fh"}, $saddr); |
1106 | # Notify parent of connect error status |
1107 | my $err = $!+0; |
1108 | my $wrstr = "$$ $err"; |
9c36735d |
1109 | # Force to 16 chars including \n |
1110 | $wrstr .= " "x(15 - length $wrstr). "\n"; |
1111 | syswrite($self->{"fork_wr"}, $wrstr, length $wrstr); |
f569508e |
1112 | exit; |
1113 | } |
1114 | } else { |
1115 | # fork() failed? |
1116 | die "fork: $!"; |
1117 | } |
1118 | return 1; |
1119 | } |
1120 | |
1121 | # Description: Wait for TCP ACK from host specified |
1122 | # from ping_syn above. If no host is specified, wait |
1123 | # for TCP ACK from any of the hosts in the SYN queue. |
1124 | sub ack |
1125 | { |
1126 | my $self = shift; |
1127 | |
1128 | if ($self->{"proto"} eq "syn") { |
1129 | if ($syn_forking) { |
1130 | my @answer = $self->ack_unfork(shift); |
1131 | return wantarray ? @answer : $answer[0]; |
1132 | } |
1133 | my $wbits = ""; |
1134 | my $stop_time = 0; |
1135 | if (my $host = shift) { |
1136 | # Host passed as arg |
1137 | if (exists $self->{"bad"}->{$host}) { |
c94ff782 |
1138 | if (!$self->{"econnrefused"} && |
69c74a9c |
1139 | $self->{"bad"}->{ $host } && |
1140 | (($! = ECONNREFUSED)>0) && |
1141 | $self->{"bad"}->{ $host } eq "$!") { |
1142 | # "Connection refused" means reachable |
1143 | # Good, continue |
1144 | } else { |
1145 | # ECONNREFUSED means no good |
1146 | return (); |
1147 | } |
f569508e |
1148 | } |
1149 | my $host_fd = undef; |
1150 | foreach my $fd (keys %{ $self->{"syn"} }) { |
1151 | my $entry = $self->{"syn"}->{$fd}; |
1152 | if ($entry->[0] eq $host) { |
1153 | $host_fd = $fd; |
1154 | $stop_time = $entry->[4] |
1155 | || croak("Corrupted SYN entry for [$host]"); |
1156 | last; |
1157 | } |
1158 | } |
1159 | croak("ack called on [$host] without calling ping first!") |
1160 | unless defined $host_fd; |
1161 | vec($wbits, $host_fd, 1) = 1; |
1162 | } else { |
1163 | # No $host passed so scan all hosts |
1164 | # Use the latest stop_time |
1165 | $stop_time = $self->{"stop_time"}; |
1166 | # Use all the bits |
1167 | $wbits = $self->{"wbits"}; |
1168 | } |
1169 | |
9c36735d |
1170 | while ($wbits !~ /^\0*\z/) { |
f569508e |
1171 | my $timeout = $stop_time - &time(); |
1172 | # Force a minimum of 10 ms timeout. |
69c74a9c |
1173 | $timeout = 0.01 if $timeout <= 0.01; |
1174 | |
1175 | my $winner_fd = undef; |
1176 | my $wout = $wbits; |
1177 | my $fd = 0; |
1178 | # Do "bad" fds from $wbits first |
9c36735d |
1179 | while ($wout !~ /^\0*\z/) { |
69c74a9c |
1180 | if (vec($wout, $fd, 1)) { |
1181 | # Wipe it from future scanning. |
1182 | vec($wout, $fd, 1) = 0; |
1183 | if (my $entry = $self->{"syn"}->{$fd}) { |
1184 | if ($self->{"bad"}->{ $entry->[0] }) { |
1185 | $winner_fd = $fd; |
1186 | last; |
1187 | } |
1188 | } |
1189 | } |
1190 | $fd++; |
1191 | } |
1192 | |
eb194dd9 |
1193 | if (defined($winner_fd) or my $nfound = mselect(undef, ($wout=$wbits), undef, $timeout)) { |
69c74a9c |
1194 | if (defined $winner_fd) { |
1195 | $fd = $winner_fd; |
1196 | } else { |
1197 | # Done waiting for one of the ACKs |
1198 | $fd = 0; |
1199 | # Determine which one |
9c36735d |
1200 | while ($wout !~ /^\0*\z/ && |
69c74a9c |
1201 | !vec($wout, $fd, 1)) { |
1202 | $fd++; |
1203 | } |
f569508e |
1204 | } |
1205 | if (my $entry = $self->{"syn"}->{$fd}) { |
69c74a9c |
1206 | # Wipe it from future scanning. |
1207 | delete $self->{"syn"}->{$fd}; |
1208 | vec($self->{"wbits"}, $fd, 1) = 0; |
1209 | vec($wbits, $fd, 1) = 0; |
c94ff782 |
1210 | if (!$self->{"econnrefused"} && |
69c74a9c |
1211 | $self->{"bad"}->{ $entry->[0] } && |
1212 | (($! = ECONNREFUSED)>0) && |
1213 | $self->{"bad"}->{ $entry->[0] } eq "$!") { |
1214 | # "Connection refused" means reachable |
1215 | # Good, continue |
1216 | } elsif (getpeername($entry->[2])) { |
f569508e |
1217 | # Connection established to remote host |
69c74a9c |
1218 | # Good, continue |
f569508e |
1219 | } else { |
1220 | # TCP ACK will never come from this host |
1221 | # because there was an error connecting. |
1222 | |
f569508e |
1223 | # This should set $! to the correct error. |
1224 | my $char; |
9c36735d |
1225 | sysread($entry->[2],$char,1); |
f569508e |
1226 | # Store the excuse why the connection failed. |
1227 | $self->{"bad"}->{$entry->[0]} = $!; |
c94ff782 |
1228 | if (!$self->{"econnrefused"} && |
69c74a9c |
1229 | (($! == ECONNREFUSED) || |
1230 | ($! == EAGAIN && $^O =~ /cygwin/i))) { |
f569508e |
1231 | # "Connection refused" means reachable |
69c74a9c |
1232 | # Good, continue |
1233 | } else { |
1234 | # No good, try the next socket... |
1235 | next; |
f569508e |
1236 | } |
f569508e |
1237 | } |
69c74a9c |
1238 | # Everything passed okay, return the answer |
1239 | return wantarray ? |
1240 | ($entry->[0], &time() - $entry->[3], inet_ntoa($entry->[1])) |
1241 | : $entry->[0]; |
f569508e |
1242 | } else { |
1243 | warn "Corrupted SYN entry: unknown fd [$fd] ready!"; |
1244 | vec($wbits, $fd, 1) = 0; |
1245 | vec($self->{"wbits"}, $fd, 1) = 0; |
1246 | } |
1247 | } elsif (defined $nfound) { |
1248 | # Timed out waiting for ACK |
1249 | foreach my $fd (keys %{ $self->{"syn"} }) { |
1250 | if (vec($wbits, $fd, 1)) { |
1251 | my $entry = $self->{"syn"}->{$fd}; |
1252 | $self->{"bad"}->{$entry->[0]} = "Timed out"; |
1253 | vec($wbits, $fd, 1) = 0; |
1254 | vec($self->{"wbits"}, $fd, 1) = 0; |
1255 | delete $self->{"syn"}->{$fd}; |
1256 | } |
1257 | } |
1258 | } else { |
1259 | # Weird error occurred with select() |
1260 | warn("select: $!"); |
1261 | $self->{"syn"} = {}; |
1262 | $wbits = ""; |
1263 | } |
1264 | } |
1265 | } |
1266 | return (); |
1267 | } |
1268 | |
1269 | sub ack_unfork { |
69c74a9c |
1270 | my ($self,$host) = @_; |
f569508e |
1271 | my $stop_time = $self->{"stop_time"}; |
69c74a9c |
1272 | if ($host) { |
f569508e |
1273 | # Host passed as arg |
69c74a9c |
1274 | if (my $entry = $self->{"good"}->{$host}) { |
1275 | delete $self->{"good"}->{$host}; |
1276 | return ($entry->[0], &time() - $entry->[3], inet_ntoa($entry->[1])); |
1277 | } |
f569508e |
1278 | } |
1279 | |
1280 | my $rbits = ""; |
1281 | my $timeout; |
69c74a9c |
1282 | |
f569508e |
1283 | if (keys %{ $self->{"syn"} }) { |
1284 | # Scan all hosts that are left |
1285 | vec($rbits, fileno($self->{"fork_rd"}), 1) = 1; |
1286 | $timeout = $stop_time - &time(); |
69c74a9c |
1287 | # Force a minimum of 10 ms timeout. |
1288 | $timeout = 0.01 if $timeout < 0.01; |
f569508e |
1289 | } else { |
1290 | # No hosts left to wait for |
1291 | $timeout = 0; |
1292 | } |
1293 | |
1294 | if ($timeout > 0) { |
69c74a9c |
1295 | my $nfound; |
1296 | while ( keys %{ $self->{"syn"} } and |
eb194dd9 |
1297 | $nfound = mselect((my $rout=$rbits), undef, undef, $timeout)) { |
f569508e |
1298 | # Done waiting for one of the ACKs |
9c36735d |
1299 | if (!sysread($self->{"fork_rd"}, $_, 16)) { |
f569508e |
1300 | # Socket closed, which means all children are done. |
1301 | return (); |
1302 | } |
1303 | my ($pid, $how) = split; |
1304 | if ($pid) { |
1305 | # Flush the zombie |
1306 | waitpid($pid, 0); |
1307 | if (my $entry = $self->{"syn"}->{$pid}) { |
1308 | # Connection attempt to remote host is done |
1309 | delete $self->{"syn"}->{$pid}; |
1310 | if (!$how || # If there was no error connecting |
c94ff782 |
1311 | (!$self->{"econnrefused"} && |
f569508e |
1312 | $how == ECONNREFUSED)) { # "Connection refused" means reachable |
69c74a9c |
1313 | if ($host && $entry->[0] ne $host) { |
1314 | # A good connection, but not the host we need. |
1315 | # Move it from the "syn" hash to the "good" hash. |
1316 | $self->{"good"}->{$entry->[0]} = $entry; |
1317 | # And wait for the next winner |
1318 | next; |
1319 | } |
f569508e |
1320 | return ($entry->[0], &time() - $entry->[3], inet_ntoa($entry->[1])); |
1321 | } |
1322 | } else { |
1323 | # Should never happen |
1324 | die "Unknown ping from pid [$pid]"; |
1325 | } |
1326 | } else { |
1327 | die "Empty response from status socket?"; |
1328 | } |
69c74a9c |
1329 | } |
1330 | if (defined $nfound) { |
f569508e |
1331 | # Timed out waiting for ACK status |
1332 | } else { |
1333 | # Weird error occurred with select() |
1334 | warn("select: $!"); |
1335 | } |
1336 | } |
1337 | if (my @synners = keys %{ $self->{"syn"} }) { |
1338 | # Kill all the synners |
1339 | kill 9, @synners; |
1340 | foreach my $pid (@synners) { |
1341 | # Wait for the deaths to finish |
1342 | # Then flush off the zombie |
1343 | waitpid($pid, 0); |
1344 | } |
1345 | } |
1346 | $self->{"syn"} = {}; |
1347 | return (); |
1348 | } |
1349 | |
1350 | # Description: Tell why the ack() failed |
1351 | sub nack { |
1352 | my $self = shift; |
1353 | my $host = shift || croak('Usage> nack($failed_ack_host)'); |
1354 | return $self->{"bad"}->{$host} || undef; |
1355 | } |
1356 | |
1357 | # Description: Close the connection. |
a3b93737 |
1358 | |
1359 | sub close |
1360 | { |
e82f584b |
1361 | my ($self) = @_; |
a3b93737 |
1362 | |
f569508e |
1363 | if ($self->{"proto"} eq "syn") { |
1364 | delete $self->{"syn"}; |
1365 | } elsif ($self->{"proto"} eq "tcp") { |
1366 | # The connection will already be closed |
1367 | } else { |
1368 | $self->{"fh"}->close(); |
1369 | } |
a3b93737 |
1370 | } |
1371 | |
1372 | |
a0d0e21e |
1373 | 1; |
8e07c86e |
1374 | __END__ |
1375 | |
8e07c86e |
1376 | =head1 NAME |
1377 | |
a3b93737 |
1378 | Net::Ping - check a remote host for reachability |
8e07c86e |
1379 | |
1380 | =head1 SYNOPSIS |
1381 | |
1382 | use Net::Ping; |
8e07c86e |
1383 | |
a3b93737 |
1384 | $p = Net::Ping->new(); |
1385 | print "$host is alive.\n" if $p->ping($host); |
1386 | $p->close(); |
1387 | |
1388 | $p = Net::Ping->new("icmp"); |
49afa5f6 |
1389 | $p->bind($my_addr); # Specify source interface of pings |
a3b93737 |
1390 | foreach $host (@host_array) |
1391 | { |
1392 | print "$host is "; |
1393 | print "NOT " unless $p->ping($host, 2); |
1394 | print "reachable.\n"; |
1395 | sleep(1); |
1396 | } |
1397 | $p->close(); |
b124990b |
1398 | |
a3b93737 |
1399 | $p = Net::Ping->new("tcp", 2); |
b124990b |
1400 | # Try connecting to the www port instead of the echo port |
1401 | $p->{port_num} = getservbyname("http", "tcp"); |
a3b93737 |
1402 | while ($stop_time > time()) |
1403 | { |
1404 | print "$host not reachable ", scalar(localtime()), "\n" |
1405 | unless $p->ping($host); |
1406 | sleep(300); |
1407 | } |
1408 | undef($p); |
b124990b |
1409 | |
f569508e |
1410 | # Like tcp protocol, but with many hosts |
1411 | $p = Net::Ping->new("syn"); |
1412 | $p->{port_num} = getservbyname("http", "tcp"); |
1413 | foreach $host (@host_array) { |
1414 | $p->ping($host); |
1415 | } |
1416 | while (($host,$rtt,$ip) = $p->ack) { |
1417 | print "HOST: $host [$ip] ACKed in $rtt seconds.\n"; |
1418 | } |
1419 | |
e82f584b |
1420 | # High precision syntax (requires Time::HiRes) |
1421 | $p = Net::Ping->new(); |
1422 | $p->hires(); |
1423 | ($ret, $duration, $ip) = $p->ping($host, 5.5); |
1424 | printf("$host [ip: $ip] is alive (packet return time: %.2f ms)\n", 1000 * $duration) |
1425 | if $ret; |
1426 | $p->close(); |
1427 | |
a3b93737 |
1428 | # For backward compatibility |
1429 | print "$host is alive.\n" if pingecho($host); |
8e07c86e |
1430 | |
a3b93737 |
1431 | =head1 DESCRIPTION |
8e07c86e |
1432 | |
a3b93737 |
1433 | This module contains methods to test the reachability of remote |
1434 | hosts on a network. A ping object is first created with optional |
1435 | parameters, a variable number of hosts may be pinged multiple |
1436 | times and then the connection is closed. |
1437 | |
f569508e |
1438 | You may choose one of six different protocols to use for the |
1439 | ping. The "tcp" protocol is the default. Note that a live remote host |
b124990b |
1440 | may still fail to be pingable by one or more of these protocols. For |
f569508e |
1441 | example, www.microsoft.com is generally alive but not "icmp" pingable. |
787ecdfa |
1442 | |
b124990b |
1443 | With the "tcp" protocol the ping() method attempts to establish a |
1444 | connection to the remote host's echo port. If the connection is |
1445 | successfully established, the remote host is considered reachable. No |
1446 | data is actually echoed. This protocol does not require any special |
9c36735d |
1447 | privileges but has higher overhead than the "udp" and "icmp" protocols. |
072620d9 |
1448 | |
b124990b |
1449 | Specifying the "udp" protocol causes the ping() method to send a udp |
a3b93737 |
1450 | packet to the remote host's echo port. If the echoed packet is |
1451 | received from the remote host and the received packet contains the |
1452 | same data as the packet that was sent, the remote host is considered |
1453 | reachable. This protocol does not require any special privileges. |
b124990b |
1454 | It should be borne in mind that, for a udp ping, a host |
787ecdfa |
1455 | will be reported as unreachable if it is not running the |
b124990b |
1456 | appropriate echo service. For Unix-like systems see L<inetd(8)> |
1457 | for more information. |
787ecdfa |
1458 | |
b124990b |
1459 | If the "icmp" protocol is specified, the ping() method sends an icmp |
1460 | echo message to the remote host, which is what the UNIX ping program |
1461 | does. If the echoed message is received from the remote host and |
1462 | the echoed information is correct, the remote host is considered |
1463 | reachable. Specifying the "icmp" protocol requires that the program |
1464 | be run as root or that the program be setuid to root. |
787ecdfa |
1465 | |
b124990b |
1466 | If the "external" protocol is specified, the ping() method attempts to |
1467 | use the C<Net::Ping::External> module to ping the remote host. |
1468 | C<Net::Ping::External> interfaces with your system's default C<ping> |
1469 | utility to perform the ping, and generally produces relatively |
787ecdfa |
1470 | accurate results. If C<Net::Ping::External> if not installed on your |
1471 | system, specifying the "external" protocol will result in an error. |
edc5bd88 |
1472 | |
f569508e |
1473 | If the "syn" protocol is specified, the ping() method will only |
1474 | send a TCP SYN packet to the remote host then immediately return. |
1475 | If the syn packet was sent successfully, it will return a true value, |
1476 | otherwise it will return false. NOTE: Unlike the other protocols, |
1477 | the return value does NOT determine if the remote host is alive or |
1478 | not since the full TCP three-way handshake may not have completed |
1479 | yet. The remote host is only considered reachable if it receives |
3c4b39be |
1480 | a TCP ACK within the timeout specified. To begin waiting for the |
f569508e |
1481 | ACK packets, use the ack() method as explained below. Use the |
1482 | "syn" protocol instead the "tcp" protocol to determine reachability |
1483 | of multiple destinations simultaneously by sending parallel TCP |
1484 | SYN packets. It will not block while testing each remote host. |
1485 | demo/fping is provided in this distribution to demonstrate the |
1486 | "syn" protocol as an example. |
1487 | This protocol does not require any special privileges. |
1488 | |
a3b93737 |
1489 | =head2 Functions |
1490 | |
1491 | =over 4 |
1492 | |
03550e9d |
1493 | =item Net::Ping->new([$proto [, $def_timeout [, $bytes [, $device [, $tos ]]]]]); |
a3b93737 |
1494 | |
1495 | Create a new ping object. All of the parameters are optional. $proto |
1496 | specifies the protocol to use when doing a ping. The current choices |
f569508e |
1497 | are "tcp", "udp", "icmp", "stream", "syn", or "external". |
1498 | The default is "tcp". |
a3b93737 |
1499 | |
1500 | If a default timeout ($def_timeout) in seconds is provided, it is used |
1501 | when a timeout is not given to the ping() method (below). The timeout |
1502 | must be greater than 0 and the default, if not specified, is 5 seconds. |
1503 | |
1504 | If the number of data bytes ($bytes) is given, that many data bytes |
1505 | are included in the ping packet sent to the remote host. The number of |
1506 | data bytes is ignored if the protocol is "tcp". The minimum (and |
1507 | default) number of data bytes is 1 if the protocol is "udp" and 0 |
1508 | otherwise. The maximum number of data bytes that can be specified is |
1509 | 1024. |
1510 | |
f569508e |
1511 | If $device is given, this device is used to bind the source endpoint |
3c4b39be |
1512 | before sending the ping packet. I believe this only works with |
f569508e |
1513 | superuser privileges and with udp and icmp protocols at this time. |
1514 | |
3c4b39be |
1515 | If $tos is given, this ToS is configured into the socket. |
03550e9d |
1516 | |
5d20095f |
1517 | =item $p->ping($host [, $timeout]); |
1518 | |
1519 | Ping the remote host and wait for a response. $host can be either the |
1520 | hostname or the IP number of the remote host. The optional timeout |
1521 | must be greater than 0 seconds and defaults to whatever was specified |
1522 | when the ping object was created. Returns a success flag. If the |
1523 | hostname cannot be found or there is a problem with the IP number, the |
1524 | success flag returned will be undef. Otherwise, the success flag will |
1525 | be 1 if the host is reachable and 0 if it is not. For most practical |
1526 | purposes, undef and 0 and can be treated as the same case. In array |
f569508e |
1527 | context, the elapsed time as well as the string form of the ip the |
1528 | host resolved to are also returned. The elapsed time value will |
5d20095f |
1529 | be a float, as retuned by the Time::HiRes::time() function, if hires() |
1530 | has been previously called, otherwise it is returned as an integer. |
1531 | |
15d96390 |
1532 | =item $p->source_verify( { 0 | 1 } ); |
1533 | |
1534 | Allows source endpoint verification to be enabled or disabled. |
1535 | This is useful for those remote destinations with multiples |
1536 | interfaces where the response may not originate from the same |
1537 | endpoint that the original destination endpoint was sent to. |
5d20095f |
1538 | This only affects udp and icmp protocol pings. |
15d96390 |
1539 | |
1540 | This is enabled by default. |
1541 | |
c94ff782 |
1542 | =item $p->service_check( { 0 | 1 } ); |
f569508e |
1543 | |
c94ff782 |
1544 | Set whether or not the connect behavior should enforce |
f569508e |
1545 | remote service availability as well as reachability. Normally, |
1546 | if the remote server reported ECONNREFUSED, it must have been |
1547 | reachable because of the status packet that it reported. |
1548 | With this option enabled, the full three-way tcp handshake |
1549 | must have been established successfully before it will |
1550 | claim it is reachable. NOTE: It still does nothing more |
1551 | than connect and disconnect. It does not speak any protocol |
1552 | (i.e., HTTP or FTP) to ensure the remote server is sane in |
1553 | any way. The remote server CPU could be grinding to a halt |
1554 | and unresponsive to any clients connecting, but if the kernel |
1555 | throws the ACK packet, it is considered alive anyway. To |
1556 | really determine if the server is responding well would be |
1557 | application specific and is beyond the scope of Net::Ping. |
c94ff782 |
1558 | For udp protocol, enabling this option demands that the |
1559 | remote server replies with the same udp data that it was sent |
1560 | as defined by the udp echo service. |
f569508e |
1561 | |
c94ff782 |
1562 | This affects the "udp", "tcp", and "syn" protocols. |
f569508e |
1563 | |
1564 | This is disabled by default. |
1565 | |
c94ff782 |
1566 | =item $p->tcp_service_check( { 0 | 1 } ); |
1567 | |
3c4b39be |
1568 | Deprecated method, but does the same as service_check() method. |
c94ff782 |
1569 | |
e82f584b |
1570 | =item $p->hires( { 0 | 1 } ); |
1571 | |
1572 | Causes this module to use Time::HiRes module, allowing milliseconds |
1573 | to be returned by subsequent calls to ping(). |
1574 | |
15d96390 |
1575 | This is disabled by default. |
1576 | |
49afa5f6 |
1577 | =item $p->bind($local_addr); |
1578 | |
1579 | Sets the source address from which pings will be sent. This must be |
1580 | the address of one of the interfaces on the local host. $local_addr |
1581 | may be specified as a hostname or as a text IP address such as |
1582 | "192.168.1.1". |
1583 | |
1584 | If the protocol is set to "tcp", this method may be called any |
1585 | number of times, and each call to the ping() method (below) will use |
1586 | the most recent $local_addr. If the protocol is "icmp" or "udp", |
1587 | then bind() must be called at most once per object, and (if it is |
1588 | called at all) must be called before the first call to ping() for that |
1589 | object. |
1590 | |
b124990b |
1591 | =item $p->open($host); |
1592 | |
f569508e |
1593 | When you are using the "stream" protocol, this call pre-opens the |
b124990b |
1594 | tcp socket. It's only necessary to do this if you want to |
1595 | provide a different timeout when creating the connection, or |
1596 | remove the overhead of establishing the connection from the |
1597 | first ping. If you don't call C<open()>, the connection is |
1598 | automatically opened the first time C<ping()> is called. |
787ecdfa |
1599 | This call simply does nothing if you are using any protocol other |
1600 | than stream. |
1601 | |
f569508e |
1602 | =item $p->ack( [ $host ] ); |
1603 | |
1604 | When using the "syn" protocol, use this method to determine |
1605 | the reachability of the remote host. This method is meant |
1606 | to be called up to as many times as ping() was called. Each |
1607 | call returns the host (as passed to ping()) that came back |
1608 | with the TCP ACK. The order in which the hosts are returned |
1609 | may not necessarily be the same order in which they were |
1610 | SYN queued using the ping() method. If the timeout is |
1611 | reached before the TCP ACK is received, or if the remote |
1612 | host is not listening on the port attempted, then the TCP |
1613 | connection will not be established and ack() will return |
1614 | undef. In list context, the host, the ack time, and the |
1615 | dotted ip string will be returned instead of just the host. |
1616 | If the optional $host argument is specified, the return |
3c4b39be |
1617 | value will be pertaining to that host only. |
f569508e |
1618 | This call simply does nothing if you are using any protocol |
1619 | other than syn. |
1620 | |
1621 | =item $p->nack( $failed_ack_host ); |
1622 | |
1623 | The reason that host $failed_ack_host did not receive a |
1624 | valid ACK. Useful to find out why when ack( $fail_ack_host ) |
1625 | returns a false value. |
1626 | |
a3b93737 |
1627 | =item $p->close(); |
1628 | |
1629 | Close the network connection for this ping object. The network |
1630 | connection is also closed by "undef $p". The network connection is |
1631 | automatically closed if the ping object goes out of scope (e.g. $p is |
1632 | local to a subroutine and you leave the subroutine). |
1633 | |
1634 | =item pingecho($host [, $timeout]); |
1635 | |
1636 | To provide backward compatibility with the previous version of |
1637 | Net::Ping, a pingecho() subroutine is available with the same |
1638 | functionality as before. pingecho() uses the tcp protocol. The |
1639 | return values and parameters are the same as described for the ping() |
1640 | method. This subroutine is obsolete and may be removed in a future |
1641 | version of Net::Ping. |
8e07c86e |
1642 | |
a3b93737 |
1643 | =back |
8e07c86e |
1644 | |
a3b93737 |
1645 | =head1 NOTES |
8e07c86e |
1646 | |
a3b93737 |
1647 | There will be less network overhead (and some efficiency in your |
1648 | program) if you specify either the udp or the icmp protocol. The tcp |
1649 | protocol will generate 2.5 times or more traffic for each ping than |
1650 | either udp or icmp. If many hosts are pinged frequently, you may wish |
1651 | to implement a small wait (e.g. 25ms or more) between each ping to |
1652 | avoid flooding your network with packets. |
8e07c86e |
1653 | |
a3b93737 |
1654 | The icmp protocol requires that the program be run as root or that it |
787ecdfa |
1655 | be setuid to root. The other protocols do not require special |
1656 | privileges, but not all network devices implement tcp or udp echo. |
8e07c86e |
1657 | |
a3b93737 |
1658 | Local hosts should normally respond to pings within milliseconds. |
1659 | However, on a very congested network it may take up to 3 seconds or |
1660 | longer to receive an echo packet from the remote host. If the timeout |
1661 | is set too low under these conditions, it will appear that the remote |
1662 | host is not reachable (which is almost the truth). |
8e07c86e |
1663 | |
a3b93737 |
1664 | Reachability doesn't necessarily mean that the remote host is actually |
787ecdfa |
1665 | functioning beyond its ability to echo packets. tcp is slightly better |
1666 | at indicating the health of a system than icmp because it uses more |
1667 | of the networking stack to respond. |
8e07c86e |
1668 | |
a3b93737 |
1669 | Because of a lack of anything better, this module uses its own |
1670 | routines to pack and unpack ICMP packets. It would be better for a |
1671 | separate module to be written which understands all of the different |
1672 | kinds of ICMP packets. |
8e07c86e |
1673 | |
5d20095f |
1674 | =head1 INSTALL |
1675 | |
1676 | The latest source tree is available via cvs: |
1677 | |
f569508e |
1678 | cvs -z3 -q -d :pserver:anonymous@cvs.roobik.com.:/usr/local/cvsroot/freeware checkout Net-Ping |
5d20095f |
1679 | cd Net-Ping |
1680 | |
1681 | The tarball can be created as follows: |
1682 | |
1683 | perl Makefile.PL ; make ; make dist |
1684 | |
1685 | The latest Net::Ping release can be found at CPAN: |
1686 | |
1687 | $CPAN/modules/by-module/Net/ |
1688 | |
1689 | 1) Extract the tarball |
1690 | |
1691 | gtar -zxvf Net-Ping-xxxx.tar.gz |
1692 | cd Net-Ping-xxxx |
1693 | |
1694 | 2) Build: |
1695 | |
1696 | make realclean |
1697 | perl Makefile.PL |
1698 | make |
1699 | make test |
1700 | |
1701 | 3) Install |
1702 | |
1703 | make install |
1704 | |
1705 | Or install it RPM Style: |
1706 | |
1707 | rpm -ta SOURCES/Net-Ping-xxxx.tar.gz |
1708 | |
1709 | rpm -ih RPMS/noarch/perl-Net-Ping-xxxx.rpm |
1710 | |
c94ff782 |
1711 | =head1 BUGS |
1712 | |
1713 | For a list of known issues, visit: |
1714 | |
1715 | https://rt.cpan.org/NoAuth/Bugs.html?Dist=Net-Ping |
1716 | |
1717 | To report a new bug, visit: |
1718 | |
1719 | https://rt.cpan.org/NoAuth/ReportBug.html?Queue=Net-Ping |
1720 | |
49afa5f6 |
1721 | =head1 AUTHORS |
b124990b |
1722 | |
e82f584b |
1723 | Current maintainer: |
49afa5f6 |
1724 | bbb@cpan.org (Rob Brown) |
b124990b |
1725 | |
e82f584b |
1726 | External protocol: |
1727 | colinm@cpan.org (Colin McMillen) |
1728 | |
b124990b |
1729 | Stream protocol: |
1730 | bronson@trestle.com (Scott Bronson) |
1731 | |
1732 | Original pingecho(): |
1733 | karrer@bernina.ethz.ch (Andreas Karrer) |
1734 | pmarquess@bfsec.bt.co.uk (Paul Marquess) |
1735 | |
1736 | Original Net::Ping author: |
1737 | mose@ns.ccsn.edu (Russell Mosemann) |
1738 | |
b124990b |
1739 | =head1 COPYRIGHT |
1740 | |
9c36735d |
1741 | Copyright (c) 2002-2003, Rob Brown. All rights reserved. |
49afa5f6 |
1742 | |
e82f584b |
1743 | Copyright (c) 2001, Colin McMillen. All rights reserved. |
b124990b |
1744 | |
1745 | This program is free software; you may redistribute it and/or |
1746 | modify it under the same terms as Perl itself. |
1747 | |
03550e9d |
1748 | $Id: Ping.pm,v 1.86 2003/06/27 21:31:07 rob Exp $ |
c94ff782 |
1749 | |
a3b93737 |
1750 | =cut |