Commit | Line | Data |
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a0d0e21e LW |
1 | package Net::Ping; |
2 | ||
b124990b | 3 | require 5.002; |
a0d0e21e LW |
4 | require Exporter; |
5 | ||
a3b93737 | 6 | use strict; |
b124990b | 7 | use vars qw(@ISA @EXPORT $VERSION |
9539e94f JH |
8 | $def_timeout $def_proto $def_factor |
9 | $max_datasize $pingstring $hires $source_verify $syn_forking); | |
f569508e HS |
10 | use Fcntl qw( F_GETFL F_SETFL O_NONBLOCK ); |
11 | use Socket qw( SOCK_DGRAM SOCK_STREAM SOCK_RAW PF_INET SOL_SOCKET | |
e82f584b | 12 | inet_aton inet_ntoa sockaddr_in ); |
9539e94f | 13 | use POSIX qw( ECONNREFUSED ECONNRESET EINPROGRESS 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 JH |
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 | $syn_forking = 0; |
a0d0e21e | 31 | |
ef73e1db JH |
32 | if ($^O =~ /Win32/i) { |
33 | # Hack to avoid this Win32 spewage: | |
34 | # Your vendor has not defined POSIX macro ECONNREFUSED | |
35 | *ECONNREFUSED = sub {10061;}; # "Unknown Error" Special Win32 Response? | |
f569508e | 36 | $syn_forking = 1; |
ef73e1db JH |
37 | }; |
38 | ||
f569508e HS |
39 | # h2ph "asm/socket.h" |
40 | # require "asm/socket.ph"; | |
41 | sub SO_BINDTODEVICE {25;} | |
42 | ||
a3b93737 RM |
43 | # Description: The pingecho() subroutine is provided for backward |
44 | # compatibility with the original Net::Ping. It accepts a host | |
45 | # name/IP and an optional timeout in seconds. Create a tcp ping | |
46 | # object and try pinging the host. The result of the ping is returned. | |
a0d0e21e | 47 | |
a3b93737 RM |
48 | sub pingecho |
49 | { | |
e82f584b JH |
50 | my ($host, # Name or IP number of host to ping |
51 | $timeout # Optional timeout in seconds | |
52 | ) = @_; | |
53 | my ($p); # A ping object | |
a0d0e21e | 54 | |
e82f584b JH |
55 | $p = Net::Ping->new("tcp", $timeout); |
56 | $p->ping($host); # Going out of scope closes the connection | |
a3b93737 | 57 | } |
a0d0e21e | 58 | |
a3b93737 RM |
59 | # Description: The new() method creates a new ping object. Optional |
60 | # parameters may be specified for the protocol to use, the timeout in | |
61 | # seconds and the size in bytes of additional data which should be | |
62 | # included in the packet. | |
63 | # After the optional parameters are checked, the data is constructed | |
64 | # and a socket is opened if appropriate. The object is returned. | |
65 | ||
66 | sub new | |
67 | { | |
e82f584b JH |
68 | my ($this, |
69 | $proto, # Optional protocol to use for pinging | |
70 | $timeout, # Optional timeout in seconds | |
f569508e HS |
71 | $data_size, # Optional additional bytes of data |
72 | $device, # Optional device to use | |
e82f584b JH |
73 | ) = @_; |
74 | my $class = ref($this) || $this; | |
75 | my $self = {}; | |
76 | my ($cnt, # Count through data bytes | |
77 | $min_datasize # Minimum data bytes required | |
78 | ); | |
79 | ||
80 | bless($self, $class); | |
81 | ||
82 | $proto = $def_proto unless $proto; # Determine the protocol | |
f569508e HS |
83 | croak('Protocol for ping must be "icmp", "udp", "tcp", "syn", "stream", or "external"') |
84 | unless $proto =~ m/^(icmp|udp|tcp|syn|stream|external)$/; | |
e82f584b JH |
85 | $self->{"proto"} = $proto; |
86 | ||
87 | $timeout = $def_timeout unless $timeout; # Determine the timeout | |
88 | croak("Default timeout for ping must be greater than 0 seconds") | |
89 | if $timeout <= 0; | |
90 | $self->{"timeout"} = $timeout; | |
91 | ||
f569508e HS |
92 | $self->{"device"} = $device; |
93 | ||
e82f584b JH |
94 | $min_datasize = ($proto eq "udp") ? 1 : 0; # Determine data size |
95 | $data_size = $min_datasize unless defined($data_size) && $proto ne "tcp"; | |
96 | croak("Data for ping must be from $min_datasize to $max_datasize bytes") | |
97 | if ($data_size < $min_datasize) || ($data_size > $max_datasize); | |
98 | $data_size-- if $self->{"proto"} eq "udp"; # We provide the first byte | |
99 | $self->{"data_size"} = $data_size; | |
100 | ||
101 | $self->{"data"} = ""; # Construct data bytes | |
102 | for ($cnt = 0; $cnt < $self->{"data_size"}; $cnt++) | |
103 | { | |
104 | $self->{"data"} .= chr($cnt % 256); | |
105 | } | |
106 | ||
107 | $self->{"local_addr"} = undef; # Don't bind by default | |
9539e94f | 108 | $self->{"retrans"} = $def_factor; # Default exponential backoff rate |
c94ff782 | 109 | $self->{"econnrefused"} = undef; # Default Connection refused behavior |
f569508e | 110 | |
e82f584b JH |
111 | $self->{"seq"} = 0; # For counting packets |
112 | if ($self->{"proto"} eq "udp") # Open a socket | |
113 | { | |
114 | $self->{"proto_num"} = (getprotobyname('udp'))[2] || | |
115 | croak("Can't udp protocol by name"); | |
116 | $self->{"port_num"} = (getservbyname('echo', 'udp'))[2] || | |
117 | croak("Can't get udp echo port by name"); | |
118 | $self->{"fh"} = FileHandle->new(); | |
119 | socket($self->{"fh"}, PF_INET, SOCK_DGRAM, | |
120 | $self->{"proto_num"}) || | |
121 | croak("udp socket error - $!"); | |
f569508e HS |
122 | if ($self->{'device'}) { |
123 | setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) | |
124 | or croak "error binding to device $self->{'device'} $!"; | |
125 | } | |
e82f584b JH |
126 | } |
127 | elsif ($self->{"proto"} eq "icmp") | |
128 | { | |
f569508e | 129 | croak("icmp ping requires root privilege") if ($> and $^O ne 'VMS' and $^O ne 'cygwin'); |
e82f584b JH |
130 | $self->{"proto_num"} = (getprotobyname('icmp'))[2] || |
131 | croak("Can't get icmp protocol by name"); | |
132 | $self->{"pid"} = $$ & 0xffff; # Save lower 16 bits of pid | |
133 | $self->{"fh"} = FileHandle->new(); | |
134 | socket($self->{"fh"}, PF_INET, SOCK_RAW, $self->{"proto_num"}) || | |
135 | croak("icmp socket error - $!"); | |
f569508e HS |
136 | if ($self->{'device'}) { |
137 | setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) | |
138 | or croak "error binding to device $self->{'device'} $!"; | |
139 | } | |
e82f584b JH |
140 | } |
141 | elsif ($self->{"proto"} eq "tcp" || $self->{"proto"} eq "stream") | |
142 | { | |
143 | $self->{"proto_num"} = (getprotobyname('tcp'))[2] || | |
144 | croak("Can't get tcp protocol by name"); | |
145 | $self->{"port_num"} = (getservbyname('echo', 'tcp'))[2] || | |
146 | croak("Can't get tcp echo port by name"); | |
147 | $self->{"fh"} = FileHandle->new(); | |
148 | } | |
f569508e HS |
149 | elsif ($self->{"proto"} eq "syn") |
150 | { | |
151 | $self->{"proto_num"} = (getprotobyname('tcp'))[2] || | |
152 | croak("Can't get tcp protocol by name"); | |
153 | $self->{"port_num"} = (getservbyname('echo', 'tcp'))[2] || | |
154 | croak("Can't get tcp echo port by name"); | |
155 | if ($syn_forking) { | |
156 | $self->{"fork_rd"} = FileHandle->new(); | |
157 | $self->{"fork_wr"} = FileHandle->new(); | |
158 | pipe($self->{"fork_rd"}, $self->{"fork_wr"}); | |
159 | $self->{"fh"} = FileHandle->new(); | |
69c74a9c HS |
160 | $self->{"good"} = {}; |
161 | $self->{"bad"} = {}; | |
f569508e HS |
162 | } else { |
163 | $self->{"wbits"} = ""; | |
164 | $self->{"bad"} = {}; | |
165 | } | |
166 | $self->{"syn"} = {}; | |
167 | $self->{"stop_time"} = 0; | |
168 | } | |
169 | elsif ($self->{"proto"} eq "external") | |
170 | { | |
171 | # No preliminary work needs to be done. | |
172 | } | |
e82f584b JH |
173 | |
174 | return($self); | |
a3b93737 | 175 | } |
a0d0e21e | 176 | |
49afa5f6 JH |
177 | # Description: Set the local IP address from which pings will be sent. |
178 | # For ICMP and UDP pings, this calls bind() on the already-opened socket; | |
179 | # for TCP pings, just saves the address to be used when the socket is | |
180 | # opened. Returns non-zero if successful; croaks on error. | |
181 | sub bind | |
182 | { | |
e82f584b JH |
183 | my ($self, |
184 | $local_addr # Name or IP number of local interface | |
185 | ) = @_; | |
186 | my ($ip # Packed IP number of $local_addr | |
187 | ); | |
188 | ||
189 | croak("Usage: \$p->bind(\$local_addr)") unless @_ == 2; | |
190 | croak("already bound") if defined($self->{"local_addr"}) && | |
191 | ($self->{"proto"} eq "udp" || $self->{"proto"} eq "icmp"); | |
192 | ||
193 | $ip = inet_aton($local_addr); | |
194 | croak("nonexistent local address $local_addr") unless defined($ip); | |
195 | $self->{"local_addr"} = $ip; # Only used if proto is tcp | |
196 | ||
197 | if ($self->{"proto"} eq "udp" || $self->{"proto"} eq "icmp") | |
198 | { | |
199 | CORE::bind($self->{"fh"}, sockaddr_in(0, $ip)) || | |
200 | croak("$self->{'proto'} bind error - $!"); | |
201 | } | |
202 | elsif ($self->{"proto"} ne "tcp") | |
203 | { | |
204 | croak("Unknown protocol \"$self->{proto}\" in bind()"); | |
205 | } | |
206 | ||
207 | return 1; | |
208 | } | |
49afa5f6 | 209 | |
49afa5f6 | 210 | |
15d96390 JH |
211 | # Description: Allow UDP source endpoint comparision to be |
212 | # skipped for those remote interfaces that do | |
213 | # not response from the same endpoint. | |
214 | ||
215 | sub source_verify | |
216 | { | |
217 | my $self = shift; | |
5d20095f JH |
218 | $source_verify = 1 unless defined |
219 | ($source_verify = ((defined $self) && (ref $self)) ? shift() : $self); | |
15d96390 JH |
220 | } |
221 | ||
c94ff782 JH |
222 | # Description: Set whether or not the connect |
223 | # behavior should enforce remote service | |
224 | # availability as well as reachability. | |
f569508e | 225 | |
c94ff782 | 226 | sub service_check |
f569508e HS |
227 | { |
228 | my $self = shift; | |
c94ff782 JH |
229 | $self->{"econnrefused"} = 1 unless defined |
230 | ($self->{"econnrefused"} = shift()); | |
231 | } | |
232 | ||
233 | sub tcp_service_check | |
234 | { | |
235 | service_check(@_); | |
f569508e HS |
236 | } |
237 | ||
9539e94f JH |
238 | # Description: Set exponential backoff for retransmission. |
239 | # Should be > 1 to retain exponential properties. | |
240 | # If set to 0, retransmissions are disabled. | |
241 | ||
242 | sub retrans | |
243 | { | |
244 | my $self = shift; | |
245 | $self->{"retrans"} = shift; | |
246 | } | |
247 | ||
e82f584b JH |
248 | # Description: allows the module to use milliseconds as returned by |
249 | # the Time::HiRes module | |
49afa5f6 | 250 | |
e82f584b JH |
251 | $hires = 0; |
252 | sub hires | |
253 | { | |
254 | my $self = shift; | |
255 | $hires = 1 unless defined | |
256 | ($hires = ((defined $self) && (ref $self)) ? shift() : $self); | |
257 | require Time::HiRes if $hires; | |
49afa5f6 JH |
258 | } |
259 | ||
e82f584b JH |
260 | sub time |
261 | { | |
262 | return $hires ? Time::HiRes::time() : CORE::time(); | |
263 | } | |
49afa5f6 | 264 | |
9c36735d JH |
265 | # Description: Sets or clears the O_NONBLOCK flag on a file handle. |
266 | sub socket_blocking_mode | |
267 | { | |
268 | my ($self, | |
269 | $fh, # the file handle whose flags are to be modified | |
270 | $block) = @_; # if true then set the blocking | |
271 | # mode (clear O_NONBLOCK), otherwise | |
272 | # set the non-blocking mode (set O_NONBLOCK) | |
273 | ||
274 | my $flags; | |
275 | if ($flags = fcntl($fh, F_GETFL, 0)) { | |
276 | $flags = $block ? ($flags & ~O_NONBLOCK) : ($flags | O_NONBLOCK); | |
277 | if (!fcntl($fh, F_SETFL, $flags)) { | |
278 | croak("fcntl F_SETFL: $!"); | |
279 | } | |
280 | } else { | |
281 | croak("fcntl F_GETFL: $!"); | |
282 | } | |
283 | } | |
284 | ||
a3b93737 RM |
285 | # Description: Ping a host name or IP number with an optional timeout. |
286 | # First lookup the host, and return undef if it is not found. Otherwise | |
b124990b | 287 | # perform the specific ping method based on the protocol. Return the |
a3b93737 RM |
288 | # result of the ping. |
289 | ||
290 | sub ping | |
291 | { | |
e82f584b JH |
292 | my ($self, |
293 | $host, # Name or IP number of host to ping | |
294 | $timeout, # Seconds after which ping times out | |
295 | ) = @_; | |
296 | my ($ip, # Packed IP number of $host | |
297 | $ret, # The return value | |
298 | $ping_time, # When ping began | |
299 | ); | |
300 | ||
301 | croak("Usage: \$p->ping(\$host [, \$timeout])") unless @_ == 2 || @_ == 3; | |
302 | $timeout = $self->{"timeout"} unless $timeout; | |
303 | croak("Timeout must be greater than 0 seconds") if $timeout <= 0; | |
304 | ||
305 | $ip = inet_aton($host); | |
c94ff782 | 306 | return () unless defined($ip); # Does host exist? |
e82f584b JH |
307 | |
308 | # Dispatch to the appropriate routine. | |
309 | $ping_time = &time(); | |
310 | if ($self->{"proto"} eq "external") { | |
311 | $ret = $self->ping_external($ip, $timeout); | |
312 | } | |
313 | elsif ($self->{"proto"} eq "udp") { | |
314 | $ret = $self->ping_udp($ip, $timeout); | |
315 | } | |
316 | elsif ($self->{"proto"} eq "icmp") { | |
317 | $ret = $self->ping_icmp($ip, $timeout); | |
318 | } | |
319 | elsif ($self->{"proto"} eq "tcp") { | |
320 | $ret = $self->ping_tcp($ip, $timeout); | |
321 | } | |
322 | elsif ($self->{"proto"} eq "stream") { | |
323 | $ret = $self->ping_stream($ip, $timeout); | |
f569508e HS |
324 | } |
325 | elsif ($self->{"proto"} eq "syn") { | |
326 | $ret = $self->ping_syn($host, $ip, $ping_time, $ping_time+$timeout); | |
e82f584b | 327 | } else { |
787ecdfa | 328 | croak("Unknown protocol \"$self->{proto}\" in ping()"); |
e82f584b JH |
329 | } |
330 | ||
331 | return wantarray ? ($ret, &time() - $ping_time, inet_ntoa($ip)) : $ret; | |
787ecdfa JH |
332 | } |
333 | ||
334 | # Uses Net::Ping::External to do an external ping. | |
335 | sub ping_external { | |
336 | my ($self, | |
337 | $ip, # Packed IP number of the host | |
338 | $timeout # Seconds after which ping times out | |
339 | ) = @_; | |
340 | ||
b124990b JH |
341 | eval { require Net::Ping::External; } |
342 | or croak('Protocol "external" not supported on your system: Net::Ping::External not found'); | |
787ecdfa | 343 | return Net::Ping::External::ping(ip => $ip, timeout => $timeout); |
a3b93737 | 344 | } |
a0d0e21e | 345 | |
49afa5f6 JH |
346 | use constant ICMP_ECHOREPLY => 0; # ICMP packet types |
347 | use constant ICMP_ECHO => 8; | |
9c36735d | 348 | use constant ICMP_STRUCT => "C2 n3 A"; # Structure of a minimal ICMP packet |
49afa5f6 JH |
349 | use constant SUBCODE => 0; # No ICMP subcode for ECHO and ECHOREPLY |
350 | use constant ICMP_FLAGS => 0; # No special flags for send or recv | |
351 | use constant ICMP_PORT => 0; # No port with ICMP | |
352 | ||
a3b93737 RM |
353 | sub ping_icmp |
354 | { | |
e82f584b JH |
355 | my ($self, |
356 | $ip, # Packed IP number of the host | |
357 | $timeout # Seconds after which ping times out | |
358 | ) = @_; | |
359 | ||
360 | my ($saddr, # sockaddr_in with port and ip | |
361 | $checksum, # Checksum of ICMP packet | |
362 | $msg, # ICMP packet to send | |
363 | $len_msg, # Length of $msg | |
364 | $rbits, # Read bits, filehandles for reading | |
365 | $nfound, # Number of ready filehandles found | |
366 | $finish_time, # Time ping should be finished | |
367 | $done, # set to 1 when we are done | |
368 | $ret, # Return value | |
369 | $recv_msg, # Received message including IP header | |
370 | $from_saddr, # sockaddr_in of sender | |
371 | $from_port, # Port packet was sent from | |
372 | $from_ip, # Packed IP of sender | |
373 | $from_type, # ICMP type | |
374 | $from_subcode, # ICMP subcode | |
375 | $from_chk, # ICMP packet checksum | |
376 | $from_pid, # ICMP packet id | |
377 | $from_seq, # ICMP packet sequence | |
378 | $from_msg # ICMP message | |
379 | ); | |
380 | ||
381 | $self->{"seq"} = ($self->{"seq"} + 1) % 65536; # Increment sequence | |
382 | $checksum = 0; # No checksum for starters | |
383 | $msg = pack(ICMP_STRUCT . $self->{"data_size"}, ICMP_ECHO, SUBCODE, | |
384 | $checksum, $self->{"pid"}, $self->{"seq"}, $self->{"data"}); | |
385 | $checksum = Net::Ping->checksum($msg); | |
386 | $msg = pack(ICMP_STRUCT . $self->{"data_size"}, ICMP_ECHO, SUBCODE, | |
387 | $checksum, $self->{"pid"}, $self->{"seq"}, $self->{"data"}); | |
388 | $len_msg = length($msg); | |
389 | $saddr = sockaddr_in(ICMP_PORT, $ip); | |
9c36735d JH |
390 | $self->{"from_ip"} = undef; |
391 | $self->{"from_type"} = undef; | |
392 | $self->{"from_subcode"} = undef; | |
e82f584b JH |
393 | send($self->{"fh"}, $msg, ICMP_FLAGS, $saddr); # Send the message |
394 | ||
395 | $rbits = ""; | |
396 | vec($rbits, $self->{"fh"}->fileno(), 1) = 1; | |
397 | $ret = 0; | |
398 | $done = 0; | |
399 | $finish_time = &time() + $timeout; # Must be done by this time | |
400 | while (!$done && $timeout > 0) # Keep trying if we have time | |
401 | { | |
9539e94f | 402 | $nfound = select((my $rout=$rbits), undef, undef, $timeout); # Wait for packet |
e82f584b JH |
403 | $timeout = $finish_time - &time(); # Get remaining time |
404 | if (!defined($nfound)) # Hmm, a strange error | |
a3b93737 | 405 | { |
e82f584b JH |
406 | $ret = undef; |
407 | $done = 1; | |
408 | } | |
409 | elsif ($nfound) # Got a packet from somewhere | |
410 | { | |
411 | $recv_msg = ""; | |
9539e94f JH |
412 | $from_pid = -1; |
413 | $from_seq = -1; | |
e82f584b JH |
414 | $from_saddr = recv($self->{"fh"}, $recv_msg, 1500, ICMP_FLAGS); |
415 | ($from_port, $from_ip) = sockaddr_in($from_saddr); | |
9c36735d | 416 | ($from_type, $from_subcode) = unpack("C2", substr($recv_msg, 20, 2)); |
9539e94f JH |
417 | if ($from_type == ICMP_ECHOREPLY) { |
418 | ($from_pid, $from_seq) = unpack("n3", substr($recv_msg, 24, 4)) | |
419 | if length $recv_msg >= 28; | |
9c36735d | 420 | } else { |
9539e94f JH |
421 | ($from_pid, $from_seq) = unpack("n3", substr($recv_msg, 52, 4)) |
422 | if length $recv_msg >= 56; | |
9c36735d JH |
423 | } |
424 | $self->{"from_ip"} = $from_ip; | |
425 | $self->{"from_type"} = $from_type; | |
426 | $self->{"from_subcode"} = $from_subcode; | |
427 | if (($from_pid == $self->{"pid"}) && # Does the packet check out? | |
428 | ($from_seq == $self->{"seq"})) { | |
429 | if ($from_type == ICMP_ECHOREPLY){ | |
430 | $ret = 1; | |
431 | } | |
e82f584b JH |
432 | $done = 1; |
433 | } | |
9c36735d | 434 | } else { # Oops, timed out |
e82f584b JH |
435 | $done = 1; |
436 | } | |
437 | } | |
438 | return $ret; | |
a3b93737 RM |
439 | } |
440 | ||
9c36735d JH |
441 | sub icmp_result { |
442 | my ($self) = @_; | |
443 | my $ip = $self->{"from_ip"} || ""; | |
444 | $ip = "\0\0\0\0" unless 4 == length $ip; | |
445 | return (inet_ntoa($ip),($self->{"from_type"} || 0), ($self->{"from_subcode"} || 0)); | |
446 | } | |
447 | ||
a3b93737 RM |
448 | # Description: Do a checksum on the message. Basically sum all of |
449 | # the short words and fold the high order bits into the low order bits. | |
450 | ||
451 | sub checksum | |
452 | { | |
e82f584b JH |
453 | my ($class, |
454 | $msg # The message to checksum | |
455 | ) = @_; | |
456 | my ($len_msg, # Length of the message | |
457 | $num_short, # The number of short words in the message | |
458 | $short, # One short word | |
459 | $chk # The checksum | |
460 | ); | |
461 | ||
462 | $len_msg = length($msg); | |
463 | $num_short = int($len_msg / 2); | |
464 | $chk = 0; | |
9c36735d | 465 | foreach $short (unpack("n$num_short", $msg)) |
e82f584b JH |
466 | { |
467 | $chk += $short; | |
468 | } # Add the odd byte in | |
469 | $chk += (unpack("C", substr($msg, $len_msg - 1, 1)) << 8) if $len_msg % 2; | |
470 | $chk = ($chk >> 16) + ($chk & 0xffff); # Fold high into low | |
471 | return(~(($chk >> 16) + $chk) & 0xffff); # Again and complement | |
a3b93737 RM |
472 | } |
473 | ||
787ecdfa | 474 | |
b124990b JH |
475 | # Description: Perform a tcp echo ping. Since a tcp connection is |
476 | # host specific, we have to open and close each connection here. We | |
477 | # can't just leave a socket open. Because of the robust nature of | |
478 | # tcp, it will take a while before it gives up trying to establish a | |
479 | # connection. Therefore, we use select() on a non-blocking socket to | |
480 | # check against our timeout. No data bytes are actually | |
481 | # sent since the successful establishment of a connection is proof | |
482 | # enough of the reachability of the remote host. Also, tcp is | |
483 | # expensive and doesn't need our help to add to the overhead. | |
484 | ||
485 | sub ping_tcp | |
787ecdfa | 486 | { |
e82f584b JH |
487 | my ($self, |
488 | $ip, # Packed IP number of the host | |
489 | $timeout # Seconds after which ping times out | |
490 | ) = @_; | |
491 | my ($ret # The return value | |
492 | ); | |
493 | ||
9c36735d | 494 | $! = 0; |
e82f584b | 495 | $ret = $self -> tcp_connect( $ip, $timeout); |
c94ff782 | 496 | if (!$self->{"econnrefused"} && |
f569508e HS |
497 | $! == ECONNREFUSED) { |
498 | $ret = 1; # "Connection refused" means reachable | |
499 | } | |
e82f584b JH |
500 | $self->{"fh"}->close(); |
501 | return $ret; | |
787ecdfa JH |
502 | } |
503 | ||
b124990b | 504 | sub tcp_connect |
787ecdfa | 505 | { |
e82f584b JH |
506 | my ($self, |
507 | $ip, # Packed IP number of the host | |
508 | $timeout # Seconds after which connect times out | |
509 | ) = @_; | |
510 | my ($saddr); # Packed IP and Port | |
b124990b | 511 | |
e82f584b | 512 | $saddr = sockaddr_in($self->{"port_num"}, $ip); |
b124990b | 513 | |
e82f584b | 514 | my $ret = 0; # Default to unreachable |
b124990b | 515 | |
e82f584b JH |
516 | my $do_socket = sub { |
517 | socket($self->{"fh"}, PF_INET, SOCK_STREAM, $self->{"proto_num"}) || | |
518 | croak("tcp socket error - $!"); | |
519 | if (defined $self->{"local_addr"} && | |
520 | !CORE::bind($self->{"fh"}, sockaddr_in(0, $self->{"local_addr"}))) { | |
521 | croak("tcp bind error - $!"); | |
522 | } | |
f569508e HS |
523 | if ($self->{'device'}) { |
524 | setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) | |
525 | or croak("error binding to device $self->{'device'} $!"); | |
526 | } | |
e82f584b JH |
527 | }; |
528 | my $do_connect = sub { | |
9c36735d JH |
529 | $self->{"ip"} = $ip; |
530 | return ($ret = connect($self->{"fh"}, $saddr)); | |
e82f584b | 531 | }; |
9c36735d JH |
532 | my $do_connect_nb = sub { |
533 | # Set O_NONBLOCK property on filehandle | |
534 | $self->socket_blocking_mode($self->{"fh"}, 0); | |
535 | ||
536 | # start the connection attempt | |
537 | if (!connect($self->{"fh"}, $saddr)) { | |
538 | if ($! == ECONNREFUSED) { | |
c94ff782 JH |
539 | $ret = 1 unless $self->{"econnrefused"}; |
540 | } elsif ($! != EINPROGRESS) { | |
9c36735d | 541 | # EINPROGRESS is the expected error code after a connect() |
c94ff782 JH |
542 | # on a non-blocking socket. But if the kernel immediately |
543 | # determined that this connect() will never work, | |
544 | # Simply respond with "unreachable" status. | |
545 | # (This can occur on some platforms with errno | |
546 | # EHOSTUNREACH or ENETUNREACH.) | |
547 | return 0; | |
548 | } else { | |
549 | # Got the expected EINPROGRESS. | |
550 | # Just wait for connection completion... | |
9c36735d JH |
551 | my ($wbits, $wout); |
552 | $wout = $wbits = ""; | |
553 | vec($wbits, $self->{"fh"}->fileno, 1) = 1; | |
554 | ||
555 | my $nfound = select(undef, ($wout = $wbits), undef, $timeout); | |
556 | warn("select: $!") unless defined $nfound; | |
557 | ||
558 | if ($nfound && vec($wout, $self->{"fh"}->fileno, 1)) { | |
559 | # the socket is ready for writing so the connection | |
560 | # attempt completed. test whether the connection | |
561 | # attempt was successful or not | |
562 | ||
563 | if (getpeername($self->{"fh"})) { | |
564 | # Connection established to remote host | |
565 | $ret = 1; | |
566 | } else { | |
567 | # TCP ACK will never come from this host | |
568 | # because there was an error connecting. | |
e82f584b | 569 | |
9c36735d JH |
570 | # This should set $! to the correct error. |
571 | my $char; | |
572 | sysread($self->{"fh"},$char,1); | |
573 | $! = ECONNREFUSED if ($! == EAGAIN && $^O =~ /cygwin/i); | |
e82f584b | 574 | |
c94ff782 | 575 | $ret = 1 if (!$self->{"econnrefused"} |
9c36735d JH |
576 | && $! == ECONNREFUSED); |
577 | } | |
578 | } else { | |
579 | # the connection attempt timed out | |
580 | } | |
581 | } | |
582 | } else { | |
583 | # Connection established to remote host | |
584 | $ret = 1; | |
585 | } | |
586 | ||
587 | # Unset O_NONBLOCK property on filehandle | |
588 | $self->socket_blocking_mode($self->{"fh"}, 1); | |
589 | $self->{"ip"} = $ip; | |
590 | return $ret; | |
591 | }; | |
592 | ||
593 | if ($syn_forking) { | |
594 | # Buggy Winsock API doesn't allow nonblocking connect. | |
e82f584b JH |
595 | # Hence, if our OS is Windows, we need to create a separate |
596 | # process to do the blocking connect attempt. | |
597 | ||
598 | $| = 1; # Clear buffer prior to fork to prevent duplicate flushing. | |
9c36735d JH |
599 | $self->{'tcp_chld'} = fork; |
600 | if (!$self->{'tcp_chld'}) { | |
601 | if (!defined $self->{'tcp_chld'}) { | |
e82f584b | 602 | # Fork did not work |
9c36735d | 603 | warn "Fork error: $!"; |
e82f584b | 604 | return 0; |
b124990b | 605 | } |
b124990b JH |
606 | &{ $do_socket }(); |
607 | ||
e82f584b | 608 | # Try a slow blocking connect() call |
9c36735d | 609 | # and report the status to the parent. |
e82f584b JH |
610 | if ( &{ $do_connect }() ) { |
611 | $self->{"fh"}->close(); | |
612 | # No error | |
613 | exit 0; | |
b124990b | 614 | } else { |
e82f584b JH |
615 | # Pass the error status to the parent |
616 | exit $!; | |
b124990b | 617 | } |
e82f584b | 618 | } |
b124990b | 619 | |
e82f584b JH |
620 | &{ $do_socket }(); |
621 | ||
622 | my $patience = &time() + $timeout; | |
623 | ||
9c36735d JH |
624 | my ($child, $child_errno); |
625 | $? = 0; $child_errno = 0; | |
e82f584b JH |
626 | # Wait up to the timeout |
627 | # And clean off the zombie | |
628 | do { | |
9c36735d JH |
629 | $child = waitpid($self->{'tcp_chld'}, &WNOHANG()); |
630 | $child_errno = $? >> 8; | |
e82f584b | 631 | select(undef, undef, undef, 0.1); |
9c36735d JH |
632 | } while &time() < $patience && $child != $self->{'tcp_chld'}; |
633 | ||
634 | if ($child == $self->{'tcp_chld'}) { | |
635 | if ($self->{"proto"} eq "stream") { | |
636 | # We need the socket connected here, in parent | |
637 | # Should be safe to connect because the child finished | |
638 | # within the timeout | |
639 | &{ $do_connect }(); | |
640 | } | |
e82f584b JH |
641 | } else { |
642 | # Time must have run out. | |
e82f584b | 643 | # Put that choking client out of its misery |
9c36735d | 644 | kill "KILL", $self->{'tcp_chld'}; |
e82f584b | 645 | # Clean off the zombie |
9c36735d | 646 | waitpid($self->{'tcp_chld'}, 0); |
e82f584b | 647 | $ret = 0; |
b124990b | 648 | } |
9c36735d JH |
649 | delete $self->{'tcp_chld'}; |
650 | $! = $child_errno; | |
651 | } else { | |
e82f584b JH |
652 | # Otherwise don't waste the resources to fork |
653 | ||
654 | &{ $do_socket }(); | |
655 | ||
9c36735d | 656 | &{ $do_connect_nb }(); |
e82f584b | 657 | } |
787ecdfa | 658 | |
e82f584b | 659 | return $ret; |
787ecdfa JH |
660 | } |
661 | ||
9c36735d JH |
662 | sub DESTROY { |
663 | my $self = shift; | |
664 | if ($self->{'proto'} eq 'tcp' && | |
665 | $self->{'tcp_chld'}) { | |
666 | # Put that choking client out of its misery | |
667 | kill "KILL", $self->{'tcp_chld'}; | |
668 | # Clean off the zombie | |
669 | waitpid($self->{'tcp_chld'}, 0); | |
670 | } | |
671 | } | |
672 | ||
787ecdfa JH |
673 | # This writes the given string to the socket and then reads it |
674 | # back. It returns 1 on success, 0 on failure. | |
675 | sub tcp_echo | |
676 | { | |
e82f584b JH |
677 | my $self = shift; |
678 | my $timeout = shift; | |
679 | my $pingstring = shift; | |
680 | ||
681 | my $ret = undef; | |
682 | my $time = &time(); | |
683 | my $wrstr = $pingstring; | |
684 | my $rdstr = ""; | |
685 | ||
686 | eval <<'EOM'; | |
687 | do { | |
688 | my $rin = ""; | |
689 | vec($rin, $self->{"fh"}->fileno(), 1) = 1; | |
690 | ||
691 | my $rout = undef; | |
692 | if($wrstr) { | |
693 | $rout = ""; | |
694 | vec($rout, $self->{"fh"}->fileno(), 1) = 1; | |
695 | } | |
696 | ||
697 | if(select($rin, $rout, undef, ($time + $timeout) - &time())) { | |
698 | ||
699 | if($rout && vec($rout,$self->{"fh"}->fileno(),1)) { | |
9c36735d | 700 | my $num = syswrite($self->{"fh"}, $wrstr, length $wrstr); |
e82f584b JH |
701 | if($num) { |
702 | # If it was a partial write, update and try again. | |
703 | $wrstr = substr($wrstr,$num); | |
704 | } else { | |
705 | # There was an error. | |
706 | $ret = 0; | |
707 | } | |
708 | } | |
709 | ||
710 | if(vec($rin,$self->{"fh"}->fileno(),1)) { | |
711 | my $reply; | |
712 | if(sysread($self->{"fh"},$reply,length($pingstring)-length($rdstr))) { | |
713 | $rdstr .= $reply; | |
714 | $ret = 1 if $rdstr eq $pingstring; | |
715 | } else { | |
716 | # There was an error. | |
717 | $ret = 0; | |
718 | } | |
719 | } | |
720 | ||
721 | } | |
722 | } until &time() > ($time + $timeout) || defined($ret); | |
787ecdfa JH |
723 | EOM |
724 | ||
e82f584b | 725 | return $ret; |
787ecdfa JH |
726 | } |
727 | ||
787ecdfa | 728 | |
787ecdfa | 729 | |
787ecdfa JH |
730 | |
731 | # Description: Perform a stream ping. If the tcp connection isn't | |
732 | # already open, it opens it. It then sends some data and waits for | |
733 | # a reply. It leaves the stream open on exit. | |
734 | ||
735 | sub ping_stream | |
736 | { | |
e82f584b JH |
737 | my ($self, |
738 | $ip, # Packed IP number of the host | |
739 | $timeout # Seconds after which ping times out | |
740 | ) = @_; | |
072620d9 | 741 | |
e82f584b JH |
742 | # Open the stream if it's not already open |
743 | if(!defined $self->{"fh"}->fileno()) { | |
744 | $self->tcp_connect($ip, $timeout) or return 0; | |
745 | } | |
787ecdfa | 746 | |
e82f584b JH |
747 | croak "tried to switch servers while stream pinging" |
748 | if $self->{"ip"} ne $ip; | |
749 | ||
750 | return $self->tcp_echo($timeout, $pingstring); | |
787ecdfa JH |
751 | } |
752 | ||
753 | # Description: opens the stream. You would do this if you want to | |
754 | # separate the overhead of opening the stream from the first ping. | |
755 | ||
756 | sub open | |
757 | { | |
e82f584b JH |
758 | my ($self, |
759 | $host, # Host or IP address | |
760 | $timeout # Seconds after which open times out | |
761 | ) = @_; | |
762 | ||
763 | my ($ip); # Packed IP number of the host | |
764 | $ip = inet_aton($host); | |
765 | $timeout = $self->{"timeout"} unless $timeout; | |
766 | ||
767 | if($self->{"proto"} eq "stream") { | |
768 | if(defined($self->{"fh"}->fileno())) { | |
769 | croak("socket is already open"); | |
770 | } else { | |
771 | $self->tcp_connect($ip, $timeout); | |
b124990b | 772 | } |
e82f584b | 773 | } |
072620d9 SB |
774 | } |
775 | ||
b124990b | 776 | |
a3b93737 RM |
777 | # Description: Perform a udp echo ping. Construct a message of |
778 | # at least the one-byte sequence number and any additional data bytes. | |
779 | # Send the message out and wait for a message to come back. If we | |
780 | # get a message, make sure all of its parts match. If they do, we are | |
781 | # done. Otherwise go back and wait for the message until we run out | |
782 | # of time. Return the result of our efforts. | |
783 | ||
49afa5f6 | 784 | use constant UDP_FLAGS => 0; # Nothing special on send or recv |
a3b93737 RM |
785 | sub ping_udp |
786 | { | |
e82f584b JH |
787 | my ($self, |
788 | $ip, # Packed IP number of the host | |
789 | $timeout # Seconds after which ping times out | |
790 | ) = @_; | |
791 | ||
792 | my ($saddr, # sockaddr_in with port and ip | |
793 | $ret, # The return value | |
794 | $msg, # Message to be echoed | |
795 | $finish_time, # Time ping should be finished | |
9539e94f JH |
796 | $flush, # Whether socket needs to be disconnected |
797 | $connect, # Whether socket needs to be connected | |
e82f584b JH |
798 | $done, # Set to 1 when we are done pinging |
799 | $rbits, # Read bits, filehandles for reading | |
800 | $nfound, # Number of ready filehandles found | |
801 | $from_saddr, # sockaddr_in of sender | |
802 | $from_msg, # Characters echoed by $host | |
803 | $from_port, # Port message was echoed from | |
804 | $from_ip # Packed IP number of sender | |
805 | ); | |
806 | ||
807 | $saddr = sockaddr_in($self->{"port_num"}, $ip); | |
808 | $self->{"seq"} = ($self->{"seq"} + 1) % 256; # Increment sequence | |
809 | $msg = chr($self->{"seq"}) . $self->{"data"}; # Add data if any | |
9539e94f JH |
810 | |
811 | if ($self->{"connected"}) { | |
812 | if ($self->{"connected"} ne $saddr) { | |
813 | # Still connected to wrong destination. | |
814 | # Need to flush out the old one. | |
815 | $flush = 1; | |
816 | } | |
817 | } else { | |
818 | # Not connected yet. | |
819 | # Need to connect() before send() | |
820 | $connect = 1; | |
821 | } | |
822 | ||
c94ff782 JH |
823 | # Have to connect() and send() instead of sendto() |
824 | # in order to pick up on the ECONNREFUSED setting | |
825 | # from recv() or double send() errno as utilized in | |
826 | # the concept by rdw @ perlmonks. See: | |
827 | # http://perlmonks.thepen.com/42898.html | |
9539e94f JH |
828 | if ($flush) { |
829 | # Need to socket() again to flush the descriptor | |
830 | # This will disconnect from the old saddr. | |
831 | socket($self->{"fh"}, PF_INET, SOCK_DGRAM, | |
832 | $self->{"proto_num"}); | |
833 | } | |
834 | # Connect the socket if it isn't already connected | |
835 | # to the right destination. | |
836 | if ($flush || $connect) { | |
837 | connect($self->{"fh"}, $saddr); # Tie destination to socket | |
838 | $self->{"connected"} = $saddr; | |
839 | } | |
c94ff782 | 840 | send($self->{"fh"}, $msg, UDP_FLAGS); # Send it |
e82f584b JH |
841 | |
842 | $rbits = ""; | |
843 | vec($rbits, $self->{"fh"}->fileno(), 1) = 1; | |
844 | $ret = 0; # Default to unreachable | |
845 | $done = 0; | |
c94ff782 | 846 | my $retrans = 0.01; |
9539e94f | 847 | my $factor = $self->{"retrans"}; |
e82f584b JH |
848 | $finish_time = &time() + $timeout; # Ping needs to be done by then |
849 | while (!$done && $timeout > 0) | |
850 | { | |
9539e94f JH |
851 | if ($factor > 1) |
852 | { | |
853 | $timeout = $retrans if $timeout > $retrans; | |
854 | $retrans*= $factor; # Exponential backoff | |
855 | } | |
856 | $nfound = select((my $rout=$rbits), undef, undef, $timeout); # Wait for response | |
c94ff782 | 857 | my $why = $!; |
e82f584b JH |
858 | $timeout = $finish_time - &time(); # Get remaining time |
859 | ||
860 | if (!defined($nfound)) # Hmm, a strange error | |
a3b93737 | 861 | { |
e82f584b JH |
862 | $ret = undef; |
863 | $done = 1; | |
a3b93737 | 864 | } |
e82f584b JH |
865 | elsif ($nfound) # A packet is waiting |
866 | { | |
867 | $from_msg = ""; | |
c94ff782 JH |
868 | $from_saddr = recv($self->{"fh"}, $from_msg, 1500, UDP_FLAGS); |
869 | if (!$from_saddr) { | |
870 | # For example an unreachable host will make recv() fail. | |
871 | if (!$self->{"econnrefused"} && | |
9539e94f JH |
872 | ($! == ECONNREFUSED || |
873 | $! == ECONNRESET)) { | |
c94ff782 JH |
874 | # "Connection refused" means reachable |
875 | # Good, continue | |
876 | $ret = 1; | |
877 | } | |
e82f584b | 878 | $done = 1; |
c94ff782 JH |
879 | } else { |
880 | ($from_port, $from_ip) = sockaddr_in($from_saddr); | |
881 | if (!$source_verify || | |
882 | (($from_ip eq $ip) && # Does the packet check out? | |
883 | ($from_port == $self->{"port_num"}) && | |
884 | ($from_msg eq $msg))) | |
885 | { | |
886 | $ret = 1; # It's a winner | |
887 | $done = 1; | |
888 | } | |
e82f584b JH |
889 | } |
890 | } | |
c94ff782 | 891 | elsif ($timeout <= 0) # Oops, timed out |
e82f584b JH |
892 | { |
893 | $done = 1; | |
894 | } | |
c94ff782 JH |
895 | else |
896 | { | |
897 | # Send another in case the last one dropped | |
898 | if (send($self->{"fh"}, $msg, UDP_FLAGS)) { | |
899 | # Another send worked? The previous udp packet | |
900 | # must have gotten lost or is still in transit. | |
901 | # Hopefully this new packet will arrive safely. | |
902 | } else { | |
903 | if (!$self->{"econnrefused"} && | |
904 | $! == ECONNREFUSED) { | |
905 | # "Connection refused" means reachable | |
906 | # Good, continue | |
907 | $ret = 1; | |
908 | } | |
909 | $done = 1; | |
910 | } | |
911 | } | |
e82f584b | 912 | } |
a5a165b1 | 913 | return $ret; |
b124990b | 914 | } |
a0d0e21e | 915 | |
f569508e HS |
916 | # Description: Send a TCP SYN packet to host specified. |
917 | sub ping_syn | |
918 | { | |
919 | my $self = shift; | |
920 | my $host = shift; | |
921 | my $ip = shift; | |
922 | my $start_time = shift; | |
923 | my $stop_time = shift; | |
924 | ||
925 | if ($syn_forking) { | |
926 | return $self->ping_syn_fork($host, $ip, $start_time, $stop_time); | |
927 | } | |
928 | ||
929 | my $fh = FileHandle->new(); | |
930 | my $saddr = sockaddr_in($self->{"port_num"}, $ip); | |
931 | ||
932 | # Create TCP socket | |
933 | if (!socket ($fh, PF_INET, SOCK_STREAM, $self->{"proto_num"})) { | |
934 | croak("tcp socket error - $!"); | |
935 | } | |
936 | ||
937 | if (defined $self->{"local_addr"} && | |
938 | !CORE::bind($fh, sockaddr_in(0, $self->{"local_addr"}))) { | |
939 | croak("tcp bind error - $!"); | |
940 | } | |
941 | ||
942 | if ($self->{'device'}) { | |
943 | setsockopt($fh, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) | |
944 | or croak("error binding to device $self->{'device'} $!"); | |
945 | } | |
946 | ||
947 | # Set O_NONBLOCK property on filehandle | |
9c36735d | 948 | $self->socket_blocking_mode($fh, 0); |
f569508e HS |
949 | |
950 | # Attempt the non-blocking connect | |
951 | # by just sending the TCP SYN packet | |
952 | if (connect($fh, $saddr)) { | |
953 | # Non-blocking, yet still connected? | |
69c74a9c HS |
954 | # Must have connected very quickly, |
955 | # or else it wasn't very non-blocking. | |
956 | #warn "WARNING: Nonblocking connect connected anyway? ($^O)"; | |
957 | } else { | |
f569508e | 958 | # Error occurred connecting. |
69c74a9c HS |
959 | if ($! == EINPROGRESS) { |
960 | # The connection is just still in progress. | |
961 | # This is the expected condition. | |
962 | } else { | |
963 | # Just save the error and continue on. | |
964 | # The ack() can check the status later. | |
f569508e | 965 | $self->{"bad"}->{$host} = $!; |
f569508e HS |
966 | } |
967 | } | |
968 | ||
969 | my $entry = [ $host, $ip, $fh, $start_time, $stop_time ]; | |
970 | $self->{"syn"}->{$fh->fileno} = $entry; | |
971 | if ($self->{"stop_time"} < $stop_time) { | |
972 | $self->{"stop_time"} = $stop_time; | |
973 | } | |
974 | vec($self->{"wbits"}, $fh->fileno, 1) = 1; | |
975 | ||
976 | return 1; | |
977 | } | |
978 | ||
979 | sub ping_syn_fork { | |
980 | my ($self, $host, $ip, $start_time, $stop_time) = @_; | |
981 | ||
982 | # Buggy Winsock API doesn't allow nonblocking connect. | |
983 | # Hence, if our OS is Windows, we need to create a separate | |
984 | # process to do the blocking connect attempt. | |
985 | my $pid = fork(); | |
986 | if (defined $pid) { | |
987 | if ($pid) { | |
988 | # Parent process | |
989 | my $entry = [ $host, $ip, $pid, $start_time, $stop_time ]; | |
990 | $self->{"syn"}->{$pid} = $entry; | |
991 | if ($self->{"stop_time"} < $stop_time) { | |
992 | $self->{"stop_time"} = $stop_time; | |
993 | } | |
994 | } else { | |
995 | # Child process | |
996 | my $saddr = sockaddr_in($self->{"port_num"}, $ip); | |
997 | ||
998 | # Create TCP socket | |
999 | if (!socket ($self->{"fh"}, PF_INET, SOCK_STREAM, $self->{"proto_num"})) { | |
1000 | croak("tcp socket error - $!"); | |
1001 | } | |
1002 | ||
1003 | if (defined $self->{"local_addr"} && | |
1004 | !CORE::bind($self->{"fh"}, sockaddr_in(0, $self->{"local_addr"}))) { | |
1005 | croak("tcp bind error - $!"); | |
1006 | } | |
1007 | ||
1008 | if ($self->{'device'}) { | |
1009 | setsockopt($self->{"fh"}, SOL_SOCKET, SO_BINDTODEVICE(), pack("Z*", $self->{'device'})) | |
1010 | or croak("error binding to device $self->{'device'} $!"); | |
1011 | } | |
1012 | ||
1013 | $!=0; | |
1014 | # Try to connect (could take a long time) | |
1015 | connect($self->{"fh"}, $saddr); | |
1016 | # Notify parent of connect error status | |
1017 | my $err = $!+0; | |
1018 | my $wrstr = "$$ $err"; | |
9c36735d JH |
1019 | # Force to 16 chars including \n |
1020 | $wrstr .= " "x(15 - length $wrstr). "\n"; | |
1021 | syswrite($self->{"fork_wr"}, $wrstr, length $wrstr); | |
f569508e HS |
1022 | exit; |
1023 | } | |
1024 | } else { | |
1025 | # fork() failed? | |
1026 | die "fork: $!"; | |
1027 | } | |
1028 | return 1; | |
1029 | } | |
1030 | ||
1031 | # Description: Wait for TCP ACK from host specified | |
1032 | # from ping_syn above. If no host is specified, wait | |
1033 | # for TCP ACK from any of the hosts in the SYN queue. | |
1034 | sub ack | |
1035 | { | |
1036 | my $self = shift; | |
1037 | ||
1038 | if ($self->{"proto"} eq "syn") { | |
1039 | if ($syn_forking) { | |
1040 | my @answer = $self->ack_unfork(shift); | |
1041 | return wantarray ? @answer : $answer[0]; | |
1042 | } | |
1043 | my $wbits = ""; | |
1044 | my $stop_time = 0; | |
1045 | if (my $host = shift) { | |
1046 | # Host passed as arg | |
1047 | if (exists $self->{"bad"}->{$host}) { | |
c94ff782 | 1048 | if (!$self->{"econnrefused"} && |
69c74a9c HS |
1049 | $self->{"bad"}->{ $host } && |
1050 | (($! = ECONNREFUSED)>0) && | |
1051 | $self->{"bad"}->{ $host } eq "$!") { | |
1052 | # "Connection refused" means reachable | |
1053 | # Good, continue | |
1054 | } else { | |
1055 | # ECONNREFUSED means no good | |
1056 | return (); | |
1057 | } | |
f569508e HS |
1058 | } |
1059 | my $host_fd = undef; | |
1060 | foreach my $fd (keys %{ $self->{"syn"} }) { | |
1061 | my $entry = $self->{"syn"}->{$fd}; | |
1062 | if ($entry->[0] eq $host) { | |
1063 | $host_fd = $fd; | |
1064 | $stop_time = $entry->[4] | |
1065 | || croak("Corrupted SYN entry for [$host]"); | |
1066 | last; | |
1067 | } | |
1068 | } | |
1069 | croak("ack called on [$host] without calling ping first!") | |
1070 | unless defined $host_fd; | |
1071 | vec($wbits, $host_fd, 1) = 1; | |
1072 | } else { | |
1073 | # No $host passed so scan all hosts | |
1074 | # Use the latest stop_time | |
1075 | $stop_time = $self->{"stop_time"}; | |
1076 | # Use all the bits | |
1077 | $wbits = $self->{"wbits"}; | |
1078 | } | |
1079 | ||
9c36735d | 1080 | while ($wbits !~ /^\0*\z/) { |
f569508e HS |
1081 | my $timeout = $stop_time - &time(); |
1082 | # Force a minimum of 10 ms timeout. | |
69c74a9c HS |
1083 | $timeout = 0.01 if $timeout <= 0.01; |
1084 | ||
1085 | my $winner_fd = undef; | |
1086 | my $wout = $wbits; | |
1087 | my $fd = 0; | |
1088 | # Do "bad" fds from $wbits first | |
9c36735d | 1089 | while ($wout !~ /^\0*\z/) { |
69c74a9c HS |
1090 | if (vec($wout, $fd, 1)) { |
1091 | # Wipe it from future scanning. | |
1092 | vec($wout, $fd, 1) = 0; | |
1093 | if (my $entry = $self->{"syn"}->{$fd}) { | |
1094 | if ($self->{"bad"}->{ $entry->[0] }) { | |
1095 | $winner_fd = $fd; | |
1096 | last; | |
1097 | } | |
1098 | } | |
1099 | } | |
1100 | $fd++; | |
1101 | } | |
1102 | ||
1103 | if (defined($winner_fd) or my $nfound = select(undef, ($wout=$wbits), undef, $timeout)) { | |
1104 | if (defined $winner_fd) { | |
1105 | $fd = $winner_fd; | |
1106 | } else { | |
1107 | # Done waiting for one of the ACKs | |
1108 | $fd = 0; | |
1109 | # Determine which one | |
9c36735d | 1110 | while ($wout !~ /^\0*\z/ && |
69c74a9c HS |
1111 | !vec($wout, $fd, 1)) { |
1112 | $fd++; | |
1113 | } | |
f569508e HS |
1114 | } |
1115 | if (my $entry = $self->{"syn"}->{$fd}) { | |
69c74a9c HS |
1116 | # Wipe it from future scanning. |
1117 | delete $self->{"syn"}->{$fd}; | |
1118 | vec($self->{"wbits"}, $fd, 1) = 0; | |
1119 | vec($wbits, $fd, 1) = 0; | |
c94ff782 | 1120 | if (!$self->{"econnrefused"} && |
69c74a9c HS |
1121 | $self->{"bad"}->{ $entry->[0] } && |
1122 | (($! = ECONNREFUSED)>0) && | |
1123 | $self->{"bad"}->{ $entry->[0] } eq "$!") { | |
1124 | # "Connection refused" means reachable | |
1125 | # Good, continue | |
1126 | } elsif (getpeername($entry->[2])) { | |
f569508e | 1127 | # Connection established to remote host |
69c74a9c | 1128 | # Good, continue |
f569508e HS |
1129 | } else { |
1130 | # TCP ACK will never come from this host | |
1131 | # because there was an error connecting. | |
1132 | ||
f569508e HS |
1133 | # This should set $! to the correct error. |
1134 | my $char; | |
9c36735d | 1135 | sysread($entry->[2],$char,1); |
f569508e HS |
1136 | # Store the excuse why the connection failed. |
1137 | $self->{"bad"}->{$entry->[0]} = $!; | |
c94ff782 | 1138 | if (!$self->{"econnrefused"} && |
69c74a9c HS |
1139 | (($! == ECONNREFUSED) || |
1140 | ($! == EAGAIN && $^O =~ /cygwin/i))) { | |
f569508e | 1141 | # "Connection refused" means reachable |
69c74a9c HS |
1142 | # Good, continue |
1143 | } else { | |
1144 | # No good, try the next socket... | |
1145 | next; | |
f569508e | 1146 | } |
f569508e | 1147 | } |
69c74a9c HS |
1148 | # Everything passed okay, return the answer |
1149 | return wantarray ? | |
1150 | ($entry->[0], &time() - $entry->[3], inet_ntoa($entry->[1])) | |
1151 | : $entry->[0]; | |
f569508e HS |
1152 | } else { |
1153 | warn "Corrupted SYN entry: unknown fd [$fd] ready!"; | |
1154 | vec($wbits, $fd, 1) = 0; | |
1155 | vec($self->{"wbits"}, $fd, 1) = 0; | |
1156 | } | |
1157 | } elsif (defined $nfound) { | |
1158 | # Timed out waiting for ACK | |
1159 | foreach my $fd (keys %{ $self->{"syn"} }) { | |
1160 | if (vec($wbits, $fd, 1)) { | |
1161 | my $entry = $self->{"syn"}->{$fd}; | |
1162 | $self->{"bad"}->{$entry->[0]} = "Timed out"; | |
1163 | vec($wbits, $fd, 1) = 0; | |
1164 | vec($self->{"wbits"}, $fd, 1) = 0; | |
1165 | delete $self->{"syn"}->{$fd}; | |
1166 | } | |
1167 | } | |
1168 | } else { | |
1169 | # Weird error occurred with select() | |
1170 | warn("select: $!"); | |
1171 | $self->{"syn"} = {}; | |
1172 | $wbits = ""; | |
1173 | } | |
1174 | } | |
1175 | } | |
1176 | return (); | |
1177 | } | |
1178 | ||
1179 | sub ack_unfork { | |
69c74a9c | 1180 | my ($self,$host) = @_; |
f569508e | 1181 | my $stop_time = $self->{"stop_time"}; |
69c74a9c | 1182 | if ($host) { |
f569508e | 1183 | # Host passed as arg |
69c74a9c HS |
1184 | if (my $entry = $self->{"good"}->{$host}) { |
1185 | delete $self->{"good"}->{$host}; | |
1186 | return ($entry->[0], &time() - $entry->[3], inet_ntoa($entry->[1])); | |
1187 | } | |
f569508e HS |
1188 | } |
1189 | ||
1190 | my $rbits = ""; | |
1191 | my $timeout; | |
69c74a9c | 1192 | |
f569508e HS |
1193 | if (keys %{ $self->{"syn"} }) { |
1194 | # Scan all hosts that are left | |
1195 | vec($rbits, fileno($self->{"fork_rd"}), 1) = 1; | |
1196 | $timeout = $stop_time - &time(); | |
69c74a9c HS |
1197 | # Force a minimum of 10 ms timeout. |
1198 | $timeout = 0.01 if $timeout < 0.01; | |
f569508e HS |
1199 | } else { |
1200 | # No hosts left to wait for | |
1201 | $timeout = 0; | |
1202 | } | |
1203 | ||
1204 | if ($timeout > 0) { | |
69c74a9c HS |
1205 | my $nfound; |
1206 | while ( keys %{ $self->{"syn"} } and | |
1207 | $nfound = select((my $rout=$rbits), undef, undef, $timeout)) { | |
f569508e | 1208 | # Done waiting for one of the ACKs |
9c36735d | 1209 | if (!sysread($self->{"fork_rd"}, $_, 16)) { |
f569508e HS |
1210 | # Socket closed, which means all children are done. |
1211 | return (); | |
1212 | } | |
1213 | my ($pid, $how) = split; | |
1214 | if ($pid) { | |
1215 | # Flush the zombie | |
1216 | waitpid($pid, 0); | |
1217 | if (my $entry = $self->{"syn"}->{$pid}) { | |
1218 | # Connection attempt to remote host is done | |
1219 | delete $self->{"syn"}->{$pid}; | |
1220 | if (!$how || # If there was no error connecting | |
c94ff782 | 1221 | (!$self->{"econnrefused"} && |
f569508e | 1222 | $how == ECONNREFUSED)) { # "Connection refused" means reachable |
69c74a9c HS |
1223 | if ($host && $entry->[0] ne $host) { |
1224 | # A good connection, but not the host we need. | |
1225 | # Move it from the "syn" hash to the "good" hash. | |
1226 | $self->{"good"}->{$entry->[0]} = $entry; | |
1227 | # And wait for the next winner | |
1228 | next; | |
1229 | } | |
f569508e HS |
1230 | return ($entry->[0], &time() - $entry->[3], inet_ntoa($entry->[1])); |
1231 | } | |
1232 | } else { | |
1233 | # Should never happen | |
1234 | die "Unknown ping from pid [$pid]"; | |
1235 | } | |
1236 | } else { | |
1237 | die "Empty response from status socket?"; | |
1238 | } | |
69c74a9c HS |
1239 | } |
1240 | if (defined $nfound) { | |
f569508e HS |
1241 | # Timed out waiting for ACK status |
1242 | } else { | |
1243 | # Weird error occurred with select() | |
1244 | warn("select: $!"); | |
1245 | } | |
1246 | } | |
1247 | if (my @synners = keys %{ $self->{"syn"} }) { | |
1248 | # Kill all the synners | |
1249 | kill 9, @synners; | |
1250 | foreach my $pid (@synners) { | |
1251 | # Wait for the deaths to finish | |
1252 | # Then flush off the zombie | |
1253 | waitpid($pid, 0); | |
1254 | } | |
1255 | } | |
1256 | $self->{"syn"} = {}; | |
1257 | return (); | |
1258 | } | |
1259 | ||
1260 | # Description: Tell why the ack() failed | |
1261 | sub nack { | |
1262 | my $self = shift; | |
1263 | my $host = shift || croak('Usage> nack($failed_ack_host)'); | |
1264 | return $self->{"bad"}->{$host} || undef; | |
1265 | } | |
1266 | ||
1267 | # Description: Close the connection. | |
a3b93737 RM |
1268 | |
1269 | sub close | |
1270 | { | |
e82f584b | 1271 | my ($self) = @_; |
a3b93737 | 1272 | |
f569508e HS |
1273 | if ($self->{"proto"} eq "syn") { |
1274 | delete $self->{"syn"}; | |
1275 | } elsif ($self->{"proto"} eq "tcp") { | |
1276 | # The connection will already be closed | |
1277 | } else { | |
1278 | $self->{"fh"}->close(); | |
1279 | } | |
a3b93737 RM |
1280 | } |
1281 | ||
1282 | ||
a0d0e21e | 1283 | 1; |
8e07c86e AD |
1284 | __END__ |
1285 | ||
8e07c86e AD |
1286 | =head1 NAME |
1287 | ||
a3b93737 | 1288 | Net::Ping - check a remote host for reachability |
8e07c86e AD |
1289 | |
1290 | =head1 SYNOPSIS | |
1291 | ||
1292 | use Net::Ping; | |
8e07c86e | 1293 | |
a3b93737 RM |
1294 | $p = Net::Ping->new(); |
1295 | print "$host is alive.\n" if $p->ping($host); | |
1296 | $p->close(); | |
1297 | ||
1298 | $p = Net::Ping->new("icmp"); | |
49afa5f6 | 1299 | $p->bind($my_addr); # Specify source interface of pings |
a3b93737 RM |
1300 | foreach $host (@host_array) |
1301 | { | |
1302 | print "$host is "; | |
1303 | print "NOT " unless $p->ping($host, 2); | |
1304 | print "reachable.\n"; | |
1305 | sleep(1); | |
1306 | } | |
1307 | $p->close(); | |
b124990b | 1308 | |
a3b93737 | 1309 | $p = Net::Ping->new("tcp", 2); |
b124990b JH |
1310 | # Try connecting to the www port instead of the echo port |
1311 | $p->{port_num} = getservbyname("http", "tcp"); | |
a3b93737 RM |
1312 | while ($stop_time > time()) |
1313 | { | |
1314 | print "$host not reachable ", scalar(localtime()), "\n" | |
1315 | unless $p->ping($host); | |
1316 | sleep(300); | |
1317 | } | |
1318 | undef($p); | |
b124990b | 1319 | |
f569508e HS |
1320 | # Like tcp protocol, but with many hosts |
1321 | $p = Net::Ping->new("syn"); | |
1322 | $p->{port_num} = getservbyname("http", "tcp"); | |
1323 | foreach $host (@host_array) { | |
1324 | $p->ping($host); | |
1325 | } | |
1326 | while (($host,$rtt,$ip) = $p->ack) { | |
1327 | print "HOST: $host [$ip] ACKed in $rtt seconds.\n"; | |
1328 | } | |
1329 | ||
e82f584b JH |
1330 | # High precision syntax (requires Time::HiRes) |
1331 | $p = Net::Ping->new(); | |
1332 | $p->hires(); | |
1333 | ($ret, $duration, $ip) = $p->ping($host, 5.5); | |
1334 | printf("$host [ip: $ip] is alive (packet return time: %.2f ms)\n", 1000 * $duration) | |
1335 | if $ret; | |
1336 | $p->close(); | |
1337 | ||
a3b93737 RM |
1338 | # For backward compatibility |
1339 | print "$host is alive.\n" if pingecho($host); | |
8e07c86e | 1340 | |
a3b93737 | 1341 | =head1 DESCRIPTION |
8e07c86e | 1342 | |
a3b93737 RM |
1343 | This module contains methods to test the reachability of remote |
1344 | hosts on a network. A ping object is first created with optional | |
1345 | parameters, a variable number of hosts may be pinged multiple | |
1346 | times and then the connection is closed. | |
1347 | ||
f569508e HS |
1348 | You may choose one of six different protocols to use for the |
1349 | ping. The "tcp" protocol is the default. Note that a live remote host | |
b124990b | 1350 | may still fail to be pingable by one or more of these protocols. For |
f569508e | 1351 | example, www.microsoft.com is generally alive but not "icmp" pingable. |
787ecdfa | 1352 | |
b124990b JH |
1353 | With the "tcp" protocol the ping() method attempts to establish a |
1354 | connection to the remote host's echo port. If the connection is | |
1355 | successfully established, the remote host is considered reachable. No | |
1356 | data is actually echoed. This protocol does not require any special | |
9c36735d | 1357 | privileges but has higher overhead than the "udp" and "icmp" protocols. |
072620d9 | 1358 | |
b124990b | 1359 | Specifying the "udp" protocol causes the ping() method to send a udp |
a3b93737 RM |
1360 | packet to the remote host's echo port. If the echoed packet is |
1361 | received from the remote host and the received packet contains the | |
1362 | same data as the packet that was sent, the remote host is considered | |
1363 | reachable. This protocol does not require any special privileges. | |
b124990b | 1364 | It should be borne in mind that, for a udp ping, a host |
787ecdfa | 1365 | will be reported as unreachable if it is not running the |
b124990b JH |
1366 | appropriate echo service. For Unix-like systems see L<inetd(8)> |
1367 | for more information. | |
787ecdfa | 1368 | |
b124990b JH |
1369 | If the "icmp" protocol is specified, the ping() method sends an icmp |
1370 | echo message to the remote host, which is what the UNIX ping program | |
1371 | does. If the echoed message is received from the remote host and | |
1372 | the echoed information is correct, the remote host is considered | |
1373 | reachable. Specifying the "icmp" protocol requires that the program | |
1374 | be run as root or that the program be setuid to root. | |
787ecdfa | 1375 | |
b124990b JH |
1376 | If the "external" protocol is specified, the ping() method attempts to |
1377 | use the C<Net::Ping::External> module to ping the remote host. | |
1378 | C<Net::Ping::External> interfaces with your system's default C<ping> | |
1379 | utility to perform the ping, and generally produces relatively | |
787ecdfa JH |
1380 | accurate results. If C<Net::Ping::External> if not installed on your |
1381 | system, specifying the "external" protocol will result in an error. | |
edc5bd88 | 1382 | |
f569508e HS |
1383 | If the "syn" protocol is specified, the ping() method will only |
1384 | send a TCP SYN packet to the remote host then immediately return. | |
1385 | If the syn packet was sent successfully, it will return a true value, | |
1386 | otherwise it will return false. NOTE: Unlike the other protocols, | |
1387 | the return value does NOT determine if the remote host is alive or | |
1388 | not since the full TCP three-way handshake may not have completed | |
1389 | yet. The remote host is only considered reachable if it receives | |
1390 | a TCP ACK within the timeout specifed. To begin waiting for the | |
1391 | ACK packets, use the ack() method as explained below. Use the | |
1392 | "syn" protocol instead the "tcp" protocol to determine reachability | |
1393 | of multiple destinations simultaneously by sending parallel TCP | |
1394 | SYN packets. It will not block while testing each remote host. | |
1395 | demo/fping is provided in this distribution to demonstrate the | |
1396 | "syn" protocol as an example. | |
1397 | This protocol does not require any special privileges. | |
1398 | ||
a3b93737 RM |
1399 | =head2 Functions |
1400 | ||
1401 | =over 4 | |
1402 | ||
f569508e | 1403 | =item Net::Ping->new([$proto [, $def_timeout [, $bytes [, $device ]]]]); |
a3b93737 RM |
1404 | |
1405 | Create a new ping object. All of the parameters are optional. $proto | |
1406 | specifies the protocol to use when doing a ping. The current choices | |
f569508e HS |
1407 | are "tcp", "udp", "icmp", "stream", "syn", or "external". |
1408 | The default is "tcp". | |
a3b93737 RM |
1409 | |
1410 | If a default timeout ($def_timeout) in seconds is provided, it is used | |
1411 | when a timeout is not given to the ping() method (below). The timeout | |
1412 | must be greater than 0 and the default, if not specified, is 5 seconds. | |
1413 | ||
1414 | If the number of data bytes ($bytes) is given, that many data bytes | |
1415 | are included in the ping packet sent to the remote host. The number of | |
1416 | data bytes is ignored if the protocol is "tcp". The minimum (and | |
1417 | default) number of data bytes is 1 if the protocol is "udp" and 0 | |
1418 | otherwise. The maximum number of data bytes that can be specified is | |
1419 | 1024. | |
1420 | ||
f569508e HS |
1421 | If $device is given, this device is used to bind the source endpoint |
1422 | before sending the ping packet. I beleive this only works with | |
1423 | superuser privileges and with udp and icmp protocols at this time. | |
1424 | ||
5d20095f JH |
1425 | =item $p->ping($host [, $timeout]); |
1426 | ||
1427 | Ping the remote host and wait for a response. $host can be either the | |
1428 | hostname or the IP number of the remote host. The optional timeout | |
1429 | must be greater than 0 seconds and defaults to whatever was specified | |
1430 | when the ping object was created. Returns a success flag. If the | |
1431 | hostname cannot be found or there is a problem with the IP number, the | |
1432 | success flag returned will be undef. Otherwise, the success flag will | |
1433 | be 1 if the host is reachable and 0 if it is not. For most practical | |
1434 | purposes, undef and 0 and can be treated as the same case. In array | |
f569508e HS |
1435 | context, the elapsed time as well as the string form of the ip the |
1436 | host resolved to are also returned. The elapsed time value will | |
5d20095f JH |
1437 | be a float, as retuned by the Time::HiRes::time() function, if hires() |
1438 | has been previously called, otherwise it is returned as an integer. | |
1439 | ||
15d96390 JH |
1440 | =item $p->source_verify( { 0 | 1 } ); |
1441 | ||
1442 | Allows source endpoint verification to be enabled or disabled. | |
1443 | This is useful for those remote destinations with multiples | |
1444 | interfaces where the response may not originate from the same | |
1445 | endpoint that the original destination endpoint was sent to. | |
5d20095f | 1446 | This only affects udp and icmp protocol pings. |
15d96390 JH |
1447 | |
1448 | This is enabled by default. | |
1449 | ||
c94ff782 | 1450 | =item $p->service_check( { 0 | 1 } ); |
f569508e | 1451 | |
c94ff782 | 1452 | Set whether or not the connect behavior should enforce |
f569508e HS |
1453 | remote service availability as well as reachability. Normally, |
1454 | if the remote server reported ECONNREFUSED, it must have been | |
1455 | reachable because of the status packet that it reported. | |
1456 | With this option enabled, the full three-way tcp handshake | |
1457 | must have been established successfully before it will | |
1458 | claim it is reachable. NOTE: It still does nothing more | |
1459 | than connect and disconnect. It does not speak any protocol | |
1460 | (i.e., HTTP or FTP) to ensure the remote server is sane in | |
1461 | any way. The remote server CPU could be grinding to a halt | |
1462 | and unresponsive to any clients connecting, but if the kernel | |
1463 | throws the ACK packet, it is considered alive anyway. To | |
1464 | really determine if the server is responding well would be | |
1465 | application specific and is beyond the scope of Net::Ping. | |
c94ff782 JH |
1466 | For udp protocol, enabling this option demands that the |
1467 | remote server replies with the same udp data that it was sent | |
1468 | as defined by the udp echo service. | |
f569508e | 1469 | |
c94ff782 | 1470 | This affects the "udp", "tcp", and "syn" protocols. |
f569508e HS |
1471 | |
1472 | This is disabled by default. | |
1473 | ||
c94ff782 JH |
1474 | =item $p->tcp_service_check( { 0 | 1 } ); |
1475 | ||
1476 | Depricated method, but does the same as service_check() method. | |
1477 | ||
e82f584b JH |
1478 | =item $p->hires( { 0 | 1 } ); |
1479 | ||
1480 | Causes this module to use Time::HiRes module, allowing milliseconds | |
1481 | to be returned by subsequent calls to ping(). | |
1482 | ||
15d96390 JH |
1483 | This is disabled by default. |
1484 | ||
49afa5f6 JH |
1485 | =item $p->bind($local_addr); |
1486 | ||
1487 | Sets the source address from which pings will be sent. This must be | |
1488 | the address of one of the interfaces on the local host. $local_addr | |
1489 | may be specified as a hostname or as a text IP address such as | |
1490 | "192.168.1.1". | |
1491 | ||
1492 | If the protocol is set to "tcp", this method may be called any | |
1493 | number of times, and each call to the ping() method (below) will use | |
1494 | the most recent $local_addr. If the protocol is "icmp" or "udp", | |
1495 | then bind() must be called at most once per object, and (if it is | |
1496 | called at all) must be called before the first call to ping() for that | |
1497 | object. | |
1498 | ||
b124990b JH |
1499 | =item $p->open($host); |
1500 | ||
f569508e | 1501 | When you are using the "stream" protocol, this call pre-opens the |
b124990b JH |
1502 | tcp socket. It's only necessary to do this if you want to |
1503 | provide a different timeout when creating the connection, or | |
1504 | remove the overhead of establishing the connection from the | |
1505 | first ping. If you don't call C<open()>, the connection is | |
1506 | automatically opened the first time C<ping()> is called. | |
787ecdfa JH |
1507 | This call simply does nothing if you are using any protocol other |
1508 | than stream. | |
1509 | ||
f569508e HS |
1510 | =item $p->ack( [ $host ] ); |
1511 | ||
1512 | When using the "syn" protocol, use this method to determine | |
1513 | the reachability of the remote host. This method is meant | |
1514 | to be called up to as many times as ping() was called. Each | |
1515 | call returns the host (as passed to ping()) that came back | |
1516 | with the TCP ACK. The order in which the hosts are returned | |
1517 | may not necessarily be the same order in which they were | |
1518 | SYN queued using the ping() method. If the timeout is | |
1519 | reached before the TCP ACK is received, or if the remote | |
1520 | host is not listening on the port attempted, then the TCP | |
1521 | connection will not be established and ack() will return | |
1522 | undef. In list context, the host, the ack time, and the | |
1523 | dotted ip string will be returned instead of just the host. | |
1524 | If the optional $host argument is specified, the return | |
1525 | value will be partaining to that host only. | |
1526 | This call simply does nothing if you are using any protocol | |
1527 | other than syn. | |
1528 | ||
1529 | =item $p->nack( $failed_ack_host ); | |
1530 | ||
1531 | The reason that host $failed_ack_host did not receive a | |
1532 | valid ACK. Useful to find out why when ack( $fail_ack_host ) | |
1533 | returns a false value. | |
1534 | ||
a3b93737 RM |
1535 | =item $p->close(); |
1536 | ||
1537 | Close the network connection for this ping object. The network | |
1538 | connection is also closed by "undef $p". The network connection is | |
1539 | automatically closed if the ping object goes out of scope (e.g. $p is | |
1540 | local to a subroutine and you leave the subroutine). | |
1541 | ||
1542 | =item pingecho($host [, $timeout]); | |
1543 | ||
1544 | To provide backward compatibility with the previous version of | |
1545 | Net::Ping, a pingecho() subroutine is available with the same | |
1546 | functionality as before. pingecho() uses the tcp protocol. The | |
1547 | return values and parameters are the same as described for the ping() | |
1548 | method. This subroutine is obsolete and may be removed in a future | |
1549 | version of Net::Ping. | |
8e07c86e | 1550 | |
a3b93737 | 1551 | =back |
8e07c86e | 1552 | |
a3b93737 | 1553 | =head1 NOTES |
8e07c86e | 1554 | |
a3b93737 RM |
1555 | There will be less network overhead (and some efficiency in your |
1556 | program) if you specify either the udp or the icmp protocol. The tcp | |
1557 | protocol will generate 2.5 times or more traffic for each ping than | |
1558 | either udp or icmp. If many hosts are pinged frequently, you may wish | |
1559 | to implement a small wait (e.g. 25ms or more) between each ping to | |
1560 | avoid flooding your network with packets. | |
8e07c86e | 1561 | |
a3b93737 | 1562 | The icmp protocol requires that the program be run as root or that it |
787ecdfa JH |
1563 | be setuid to root. The other protocols do not require special |
1564 | privileges, but not all network devices implement tcp or udp echo. | |
8e07c86e | 1565 | |
a3b93737 RM |
1566 | Local hosts should normally respond to pings within milliseconds. |
1567 | However, on a very congested network it may take up to 3 seconds or | |
1568 | longer to receive an echo packet from the remote host. If the timeout | |
1569 | is set too low under these conditions, it will appear that the remote | |
1570 | host is not reachable (which is almost the truth). | |
8e07c86e | 1571 | |
a3b93737 | 1572 | Reachability doesn't necessarily mean that the remote host is actually |
787ecdfa JH |
1573 | functioning beyond its ability to echo packets. tcp is slightly better |
1574 | at indicating the health of a system than icmp because it uses more | |
1575 | of the networking stack to respond. | |
8e07c86e | 1576 | |
a3b93737 RM |
1577 | Because of a lack of anything better, this module uses its own |
1578 | routines to pack and unpack ICMP packets. It would be better for a | |
1579 | separate module to be written which understands all of the different | |
1580 | kinds of ICMP packets. | |
8e07c86e | 1581 | |
5d20095f JH |
1582 | =head1 INSTALL |
1583 | ||
1584 | The latest source tree is available via cvs: | |
1585 | ||
f569508e | 1586 | cvs -z3 -q -d :pserver:anonymous@cvs.roobik.com.:/usr/local/cvsroot/freeware checkout Net-Ping |
5d20095f JH |
1587 | cd Net-Ping |
1588 | ||
1589 | The tarball can be created as follows: | |
1590 | ||
1591 | perl Makefile.PL ; make ; make dist | |
1592 | ||
1593 | The latest Net::Ping release can be found at CPAN: | |
1594 | ||
1595 | $CPAN/modules/by-module/Net/ | |
1596 | ||
1597 | 1) Extract the tarball | |
1598 | ||
1599 | gtar -zxvf Net-Ping-xxxx.tar.gz | |
1600 | cd Net-Ping-xxxx | |
1601 | ||
1602 | 2) Build: | |
1603 | ||
1604 | make realclean | |
1605 | perl Makefile.PL | |
1606 | make | |
1607 | make test | |
1608 | ||
1609 | 3) Install | |
1610 | ||
1611 | make install | |
1612 | ||
1613 | Or install it RPM Style: | |
1614 | ||
1615 | rpm -ta SOURCES/Net-Ping-xxxx.tar.gz | |
1616 | ||
1617 | rpm -ih RPMS/noarch/perl-Net-Ping-xxxx.rpm | |
1618 | ||
c94ff782 JH |
1619 | =head1 BUGS |
1620 | ||
1621 | For a list of known issues, visit: | |
1622 | ||
1623 | https://rt.cpan.org/NoAuth/Bugs.html?Dist=Net-Ping | |
1624 | ||
1625 | To report a new bug, visit: | |
1626 | ||
1627 | https://rt.cpan.org/NoAuth/ReportBug.html?Queue=Net-Ping | |
1628 | ||
49afa5f6 | 1629 | =head1 AUTHORS |
b124990b | 1630 | |
e82f584b | 1631 | Current maintainer: |
49afa5f6 | 1632 | bbb@cpan.org (Rob Brown) |
b124990b | 1633 | |
e82f584b JH |
1634 | External protocol: |
1635 | colinm@cpan.org (Colin McMillen) | |
1636 | ||
b124990b JH |
1637 | Stream protocol: |
1638 | bronson@trestle.com (Scott Bronson) | |
1639 | ||
1640 | Original pingecho(): | |
1641 | karrer@bernina.ethz.ch (Andreas Karrer) | |
1642 | pmarquess@bfsec.bt.co.uk (Paul Marquess) | |
1643 | ||
1644 | Original Net::Ping author: | |
1645 | mose@ns.ccsn.edu (Russell Mosemann) | |
1646 | ||
b124990b JH |
1647 | =head1 COPYRIGHT |
1648 | ||
9c36735d | 1649 | Copyright (c) 2002-2003, Rob Brown. All rights reserved. |
49afa5f6 | 1650 | |
e82f584b | 1651 | Copyright (c) 2001, Colin McMillen. All rights reserved. |
b124990b JH |
1652 | |
1653 | This program is free software; you may redistribute it and/or | |
1654 | modify it under the same terms as Perl itself. | |
1655 | ||
9539e94f | 1656 | $Id: Ping.pm,v 1.81 2003/04/18 04:16:03 rob Exp $ |
c94ff782 | 1657 | |
a3b93737 | 1658 | =cut |