| 1 | #!/usr/bin/env python |
| 2 | # coding: utf-8 |
| 3 | |
| 4 | """ |
| 5 | A pure python ping implementation using raw sockets. |
| 6 | |
| 7 | Note that ICMP messages can only be send from processes running as root |
| 8 | (in Windows, you must run this script as 'Administrator'). |
| 9 | |
| 10 | Bugs are naturally mine. I'd be glad to hear about them. There are |
| 11 | certainly word - size dependencies here. |
| 12 | |
| 13 | :homepage: https://github.com/jedie/python-ping/ |
| 14 | :copyleft: 1989-2011 by the python-ping team, see AUTHORS for more details. |
| 15 | :license: GNU GPL v2, see LICENSE for more details. |
| 16 | """ |
| 17 | |
| 18 | |
| 19 | import array |
| 20 | import os |
| 21 | import select |
| 22 | import signal |
| 23 | import socket |
| 24 | import struct |
| 25 | import sys |
| 26 | import time |
| 27 | |
| 28 | |
| 29 | if sys.platform.startswith("win32"): |
| 30 | # On Windows, the best timer is time.clock() |
| 31 | default_timer = time.clock |
| 32 | else: |
| 33 | # On most other platforms the best timer is time.time() |
| 34 | default_timer = time.time |
| 35 | |
| 36 | |
| 37 | # ICMP parameters |
| 38 | ICMP_ECHOREPLY = 0 # Echo reply (per RFC792) |
| 39 | ICMP_ECHO = 8 # Echo request (per RFC792) |
| 40 | ICMP_MAX_RECV = 2048 # Max size of incoming buffer |
| 41 | |
| 42 | MAX_SLEEP = 1000 |
| 43 | |
| 44 | |
| 45 | def calculate_checksum(source_string): |
| 46 | """ |
| 47 | A port of the functionality of in_cksum() from ping.c |
| 48 | Ideally this would act on the string as a series of 16-bit ints (host |
| 49 | packed), but this works. |
| 50 | Network data is big-endian, hosts are typically little-endian |
| 51 | """ |
| 52 | if len(source_string)%2: |
| 53 | source_string += "\x00" |
| 54 | converted = array.array("H", source_string) |
| 55 | if sys.byteorder == "big": |
| 56 | converted.byteswap() |
| 57 | val = sum(converted) |
| 58 | |
| 59 | val &= 0xffffffff # Truncate val to 32 bits (a variance from ping.c, which |
| 60 | # uses signed ints, but overflow is unlikely in ping) |
| 61 | |
| 62 | val = (val >> 16) + (val & 0xffff) # Add high 16 bits to low 16 bits |
| 63 | val += (val >> 16) # Add carry from above (if any) |
| 64 | answer = ~val & 0xffff # Invert and truncate to 16 bits |
| 65 | answer = socket.htons(answer) |
| 66 | |
| 67 | return answer |
| 68 | |
| 69 | |
| 70 | def is_valid_ip4_address(addr): |
| 71 | parts = addr.split(".") |
| 72 | if not len(parts) == 4: |
| 73 | return False |
| 74 | for part in parts: |
| 75 | try: |
| 76 | number = int(part) |
| 77 | except ValueError: |
| 78 | return False |
| 79 | if number > 255: |
| 80 | return False |
| 81 | return True |
| 82 | |
| 83 | def to_ip(addr): |
| 84 | if is_valid_ip4_address(addr): |
| 85 | return addr |
| 86 | return socket.gethostbyname(addr) |
| 87 | |
| 88 | |
| 89 | class Ping(object): |
| 90 | def __init__(self, destination, timeout=1000, packet_size=55, own_id=None): |
| 91 | self.destination = destination |
| 92 | self.timeout = timeout |
| 93 | self.packet_size = packet_size |
| 94 | if own_id is None: |
| 95 | self.own_id = os.getpid() & 0xFFFF |
| 96 | else: |
| 97 | self.own_id = own_id |
| 98 | |
| 99 | try: |
| 100 | # FIXME: Use destination only for display this line here? see: https://github.com/jedie/python-ping/issues/3 |
| 101 | self.dest_ip = to_ip(self.destination) |
| 102 | except socket.gaierror as e: |
| 103 | self.print_unknown_host(e) |
| 104 | # else: |
| 105 | # self.print_start() |
| 106 | |
| 107 | self.seq_number = 0 |
| 108 | self.send_count = 0 |
| 109 | self.receive_count = 0 |
| 110 | self.min_time = 999999999 |
| 111 | self.max_time = 0.0 |
| 112 | self.total_time = 0.0 |
| 113 | |
| 114 | #-------------------------------------------------------------------------- |
| 115 | |
| 116 | def print_start(self): |
| 117 | print("\nPYTHON-PING %s (%s): %d data bytes" % (self.destination, self.dest_ip, self.packet_size)) |
| 118 | |
| 119 | def print_unknown_host(self, e): |
| 120 | print("\nPYTHON-PING: Unknown host: %s (%s)\n" % (self.destination, e.args[1])) |
| 121 | sys.exit(-1) |
| 122 | |
| 123 | def print_success(self, delay, ip, packet_size, ip_header, icmp_header): |
| 124 | if ip == self.destination: |
| 125 | from_info = ip |
| 126 | else: |
| 127 | from_info = "%s (%s)" % (self.destination, ip) |
| 128 | |
| 129 | print("%d bytes from %s: icmp_seq=%d ttl=%d time=%.1f ms" % ( |
| 130 | packet_size, from_info, icmp_header["seq_number"], ip_header["ttl"], delay) |
| 131 | ) |
| 132 | #print("IP header: %r" % ip_header) |
| 133 | #print("ICMP header: %r" % icmp_header) |
| 134 | |
| 135 | def print_failed(self): |
| 136 | print("Request timed out.") |
| 137 | |
| 138 | def print_exit(self): |
| 139 | print("\n----%s PYTHON PING Statistics----" % (self.destination)) |
| 140 | |
| 141 | lost_count = self.send_count - self.receive_count |
| 142 | #print("%i packets lost" % lost_count) |
| 143 | lost_rate = float(lost_count) / self.send_count * 100.0 |
| 144 | |
| 145 | print("%d packets transmitted, %d packets received, %0.1f%% packet loss" % ( |
| 146 | self.send_count, self.receive_count, lost_rate |
| 147 | )) |
| 148 | |
| 149 | if self.receive_count > 0: |
| 150 | print("round-trip (ms) min/avg/max = %0.3f/%0.3f/%0.3f" % ( |
| 151 | self.min_time, self.total_time / self.receive_count, self.max_time |
| 152 | )) |
| 153 | |
| 154 | print("") |
| 155 | |
| 156 | #-------------------------------------------------------------------------- |
| 157 | |
| 158 | def signal_handler(self, signum, frame): |
| 159 | """ |
| 160 | Handle print_exit via signals |
| 161 | """ |
| 162 | self.print_exit() |
| 163 | print("\n(Terminated with signal %d)\n" % (signum)) |
| 164 | sys.exit(0) |
| 165 | |
| 166 | def setup_signal_handler(self): |
| 167 | signal.signal(signal.SIGINT, self.signal_handler) # Handle Ctrl-C |
| 168 | if hasattr(signal, "SIGBREAK"): |
| 169 | # Handle Ctrl-Break e.g. under Windows |
| 170 | signal.signal(signal.SIGBREAK, self.signal_handler) |
| 171 | |
| 172 | #-------------------------------------------------------------------------- |
| 173 | |
| 174 | def header2dict(self, names, struct_format, data): |
| 175 | """ unpack the raw received IP and ICMP header informations to a dict """ |
| 176 | unpacked_data = struct.unpack(struct_format, data) |
| 177 | return dict(zip(names, unpacked_data)) |
| 178 | |
| 179 | #-------------------------------------------------------------------------- |
| 180 | |
| 181 | def run(self, count=None, deadline=None): |
| 182 | """ |
| 183 | send and receive pings in a loop. Stop if count or until deadline. |
| 184 | """ |
| 185 | self.setup_signal_handler() |
| 186 | |
| 187 | while True: |
| 188 | delay = self.do() |
| 189 | |
| 190 | self.seq_number += 1 |
| 191 | if count and self.seq_number >= count: |
| 192 | break |
| 193 | if deadline and self.total_time >= deadline: |
| 194 | break |
| 195 | |
| 196 | if delay == None: |
| 197 | delay = 0 |
| 198 | |
| 199 | # Pause for the remainder of the MAX_SLEEP period (if applicable) |
| 200 | if (MAX_SLEEP > delay): |
| 201 | time.sleep((MAX_SLEEP - delay) / 1000.0) |
| 202 | |
| 203 | self.print_exit() |
| 204 | |
| 205 | def do(self): |
| 206 | """ |
| 207 | Send one ICMP ECHO_REQUEST and receive the response until self.timeout |
| 208 | """ |
| 209 | try: # One could use UDP here, but it's obscure |
| 210 | current_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.getprotobyname("icmp")) |
| 211 | except socket.error, (errno, msg): |
| 212 | if errno == 1: |
| 213 | # Operation not permitted - Add more information to traceback |
| 214 | etype, evalue, etb = sys.exc_info() |
| 215 | evalue = etype( |
| 216 | "%s - Note that ICMP messages can only be send from processes running as root." % evalue |
| 217 | ) |
| 218 | raise etype, evalue, etb |
| 219 | raise # raise the original error |
| 220 | |
| 221 | send_time = self.send_one_ping(current_socket) |
| 222 | if send_time == None: |
| 223 | return |
| 224 | self.send_count += 1 |
| 225 | |
| 226 | receive_time, packet_size, ip, ip_header, icmp_header = self.receive_one_ping(current_socket) |
| 227 | current_socket.close() |
| 228 | |
| 229 | if receive_time: |
| 230 | self.receive_count += 1 |
| 231 | delay = (receive_time - send_time) * 1000.0 |
| 232 | self.total_time += delay |
| 233 | if self.min_time > delay: |
| 234 | self.min_time = delay |
| 235 | if self.max_time < delay: |
| 236 | self.max_time = delay |
| 237 | |
| 238 | # self.print_success(delay, ip, packet_size, ip_header, icmp_header) |
| 239 | return delay |
| 240 | # else: |
| 241 | # self.print_failed() |
| 242 | |
| 243 | def send_one_ping(self, current_socket): |
| 244 | """ |
| 245 | Send one ICMP ECHO_REQUEST |
| 246 | """ |
| 247 | # Header is type (8), code (8), checksum (16), id (16), sequence (16) |
| 248 | checksum = 0 |
| 249 | |
| 250 | # Make a dummy header with a 0 checksum. |
| 251 | header = struct.pack( |
| 252 | "!BBHHH", ICMP_ECHO, 0, checksum, self.own_id, self.seq_number |
| 253 | ) |
| 254 | |
| 255 | padBytes = [] |
| 256 | startVal = 0x42 |
| 257 | for i in range(startVal, startVal + (self.packet_size)): |
| 258 | padBytes += [(i & 0xff)] # Keep chars in the 0-255 range |
| 259 | data = bytes(padBytes) |
| 260 | |
| 261 | # Calculate the checksum on the data and the dummy header. |
| 262 | checksum = calculate_checksum(header + data) # Checksum is in network order |
| 263 | |
| 264 | # Now that we have the right checksum, we put that in. It's just easier |
| 265 | # to make up a new header than to stuff it into the dummy. |
| 266 | header = struct.pack( |
| 267 | "!BBHHH", ICMP_ECHO, 0, checksum, self.own_id, self.seq_number |
| 268 | ) |
| 269 | |
| 270 | packet = header + data |
| 271 | |
| 272 | send_time = default_timer() |
| 273 | |
| 274 | try: |
| 275 | current_socket.sendto(packet, (self.destination, 1)) # Port number is irrelevant for ICMP |
| 276 | except socket.error as e: |
| 277 | print("General failure (%s)" % (e.args[1])) |
| 278 | current_socket.close() |
| 279 | return |
| 280 | |
| 281 | return send_time |
| 282 | |
| 283 | def receive_one_ping(self, current_socket): |
| 284 | """ |
| 285 | Receive the ping from the socket. timeout = in ms |
| 286 | """ |
| 287 | timeout = self.timeout / 1000.0 |
| 288 | |
| 289 | while True: # Loop while waiting for packet or timeout |
| 290 | select_start = default_timer() |
| 291 | inputready, outputready, exceptready = select.select([current_socket], [], [], timeout) |
| 292 | select_duration = (default_timer() - select_start) |
| 293 | if inputready == []: # timeout |
| 294 | return None, 0, 0, 0, 0 |
| 295 | |
| 296 | receive_time = default_timer() |
| 297 | |
| 298 | packet_data, address = current_socket.recvfrom(ICMP_MAX_RECV) |
| 299 | |
| 300 | icmp_header = self.header2dict( |
| 301 | names=[ |
| 302 | "type", "code", "checksum", |
| 303 | "packet_id", "seq_number" |
| 304 | ], |
| 305 | struct_format="!BBHHH", |
| 306 | data=packet_data[20:28] |
| 307 | ) |
| 308 | |
| 309 | if icmp_header["packet_id"] == self.own_id: # Our packet |
| 310 | ip_header = self.header2dict( |
| 311 | names=[ |
| 312 | "version", "type", "length", |
| 313 | "id", "flags", "ttl", "protocol", |
| 314 | "checksum", "src_ip", "dest_ip" |
| 315 | ], |
| 316 | struct_format="!BBHHHBBHII", |
| 317 | data=packet_data[:20] |
| 318 | ) |
| 319 | packet_size = len(packet_data) - 28 |
| 320 | ip = socket.inet_ntoa(struct.pack("!I", ip_header["src_ip"])) |
| 321 | # XXX: Why not ip = address[0] ??? |
| 322 | return receive_time, packet_size, ip, ip_header, icmp_header |
| 323 | |
| 324 | timeout = timeout - select_duration |
| 325 | if timeout <= 0: |
| 326 | return None, 0, 0, 0, 0 |
| 327 | |
| 328 | |
| 329 | def verbose_ping(hostname, timeout=1000, count=3, packet_size=55): |
| 330 | p = Ping(hostname, timeout, packet_size) |
| 331 | p.run(count) |
| 332 | |
| 333 | |
| 334 | if __name__ == '__main__': |
| 335 | # FIXME: Add a real CLI |
| 336 | if len(sys.argv) == 1: |
| 337 | print "DEMO" |
| 338 | |
| 339 | # These should work: |
| 340 | verbose_ping("heise.de") |
| 341 | verbose_ping("google.com") |
| 342 | |
| 343 | # Inconsistent on Windows w/ ActivePython (Python 3.2 resolves correctly |
| 344 | # to the local host, but 2.7 tries to resolve to the local *gateway*) |
| 345 | verbose_ping("localhost") |
| 346 | |
| 347 | # Should fail with 'getaddrinfo print_failed': |
| 348 | verbose_ping("foobar_url.foobar") |
| 349 | |
| 350 | # Should fail (timeout), but it depends on the local network: |
| 351 | verbose_ping("192.168.255.254") |
| 352 | |
| 353 | # Should fails with 'The requested address is not valid in its context': |
| 354 | verbose_ping("0.0.0.0") |
| 355 | elif len(sys.argv) == 2: |
| 356 | verbose_ping(sys.argv[1]) |
| 357 | else: |
| 358 | print "Error: call ./ping.py domain.tld" |