def measure_distance(destination):
lat1, long1 = get_geo_coord(localinfo.get_local_ip())
lat2, long2 = get_geo_coord(socket.gethostbyname(destination))
delta_lat = fabs(lat2-lat1)
delta_long = fabs(long2-long1)
# The Haversine formula
# http://www.movable-type.co.uk/scripts/latlong.html
# "a is the square of half of the chord length between the points"
# "c is the angular distance in radians"
a = sin(delta_lat/2)**2 + (cos(lat1) * cos(lat2) * sin(delta_long/2)**2)
c = 2 * atan2(sqrt(a), sqrt(1-a))
# Mean Earth Radius in kilometers
earth_radius = 6371
# Distance in kilometers
distance = earth_radius * c
print "Distance for %s: %d km" % (destination, distance)
def measure_info(destination):
# The official traceroute port should return port unreachable ICMP packets/messages
# Other ports would work as well ie 49152 through 65535 and really any normally unused port
# https://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers#Dynamic.2C_private_or_ephemeral_ports
port = 33434
# Get the expected protocols for the sockets
icmp = socket.getprotobyname('icmp')
udp = socket.getprotobyname('udp')
# A known ttl
ttl = 32
# A known message
message = "abcdefgh"
# Get the destination IP - non-deterministic gets first DNS response
destination_ip = socket.gethostbyname(destination)
# Create sockets
# One to send a packet with a known ttl
sender = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, udp)
# Set the TTL explicitly so that we know what it was originally
sender.setsockopt(socket.SOL_IP, socket.IP_TTL, ttl)
# One to receive an ICMP packet ideally with code 3
receiver = socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp)
# Set the blocking receiver to time out if no response
receiver.settimeout(3)
# Start a timer to get RTT
start_time = time.time()
# Send the packet to the destination
sender.sendto(message, (destination_ip, port))
# Attempt to get the data from the receiver by polling
try:
# Get data from the receiver = the argument is the buffer size
data, addr = receiver.recvfrom(2048)
# Stop the timer
end_time = time.time()
except socket.error:
print "%s did not respond or the packet was lost." % (destination)
return
finally:
# Close the sockets
sender.close()
receiver.close()
# Process the data and determine how many hops the packet travelled
# The first 20 bytes of the response 0 - 19 is the containing IPv4 header
# The next 8 are the ICMP response 20-27
# Specifically byte 20 is the type should be 3 for destination unreachable
# Specifically byte 21 is the code should be 3 for port unreachable
# The next 20 28 - 47 bytes are the IPv4 headers sent earlier
# Specifically byte 36 is the ttl field indicating how many steps it took to get to the destination
# The last 8 48 - 55 are the data in the packet sent
icmp_type = ord(data[20])
icmp_code = ord(data[21])
new_ttl = ord(data[36])
response_source_ip = make_string_ip(data[40:44])
response_destination_ip = make_string_ip(data[44:48])
icmp_source_ip = make_string_ip(data[12:16])
icmp_destination_ip = make_string_ip(data[16:20])
if (
# The message is not ICMP destination / port unreachable
icmp_type != 3 or icmp_code != 3 or
# The source IP on the IPv4 packet within the ICMP does not match our IP
response_source_ip != localinfo.get_local_ip() or
# The destination IP on the IPv4 packet within the ICMP does not match the destination
response_destination_ip != destination_ip or
# The source IP on the ICMP packet is not the destination
icmp_source_ip != destination_ip or
# The destination IP on the ICMP packet is not this address
icmp_destination_ip != localinfo.get_local_ip() or
# The ICMP packet returned my message and it doesn't match
(len(data) == 64 and not do_bytes_match_string(data[len(data)-8:], message))
):
print "Did not receive expected response for host %s." % (destination)
return
hop_count = ttl - new_ttl
print "Data for host: %s (%s)" % (destination, destination_ip)
print "Hops: %d" % (hop_count)
time_in_sec = end_time - start_time
time_in_milli_sec = time_in_sec * 1000
print "RTT (milliseconds): %f" % (time_in_milli_sec)
return hop_count, time_in_milli_sec
