Index: netcat-openbsd-1.203/netcat.c =================================================================== --- netcat-openbsd-1.203.orig/netcat.c +++ netcat-openbsd-1.203/netcat.c @@ -1889,6 +1889,21 @@ udptest(int s) return 1; } +static int +enable_icmp_errors (int family, int fd) +{ + int one = 1; + switch (family) + { + case AF_INET: + return setsockopt (fd, SOL_IP, IP_RECVERR, &one, sizeof (one)); + case AF_INET6: + return setsockopt (fd, SOL_IPV6, IPV6_RECVERR, &one, sizeof (one)); + default: + return -1; + } +} + void set_common_sockopts(int s, const struct sockaddr* sa) { @@ -1982,6 +1997,8 @@ set_common_sockopts(int s, const struct errx(1, "can't set IPv6 min hop count (unavailable)"); #endif } + if(uflag) + enable_icmp_errors(af,s); } int