Incorrect ICMP packet header parsing

[makstamoian]

ICMP packet headers are parsed wrongly. Since SOCK_RAW is used, the result of recvfrom also includes IP headers. Therefore, ICMP headers begin after IP headers end – in your case, they start not at &pckt, but at &pckt + ip_headers_length point. You need to use iphdr struct, to parse them properly.

This line is entirely wrong:

ping/ping.cpp

Line 235 in 05dbc75

if ( !(pckt.hdr.type == 69 && pckt.hdr.code == 0) )

type and code would be a part of IP headers and the number 69 has nothing to do with the ICMP protocol.