On 09/16/2015 11:54 AM, Matteo Croce wrote:
Add option to disable any reply not related to a listening socket, like RST/ACK for TCP and ICMP Port-Unreachable for UDP. Also disables ICMP replies to echo request and timestamp. The stealth mode can be enabled selectively for a single interface.Signed-off-by: Matteo Croce <mat...@openwrt.org> --- rebased on 4.3-rc1 Documentation/networking/ip-sysctl.txt | 14 ++++++++++++++ include/linux/inetdevice.h | 1 + include/linux/ipv6.h | 1 + include/uapi/linux/ip.h | 1 + net/ipv4/devinet.c | 1 + net/ipv4/icmp.c | 6 ++++++ net/ipv4/ip_input.c | 5 +++-- net/ipv4/tcp_ipv4.c | 3 ++- net/ipv4/udp.c | 4 +++- net/ipv6/addrconf.c | 7 +++++++ net/ipv6/icmp.c | 3 ++- net/ipv6/ip6_input.c | 5 +++-- net/ipv6/tcp_ipv6.c | 2 +- net/ipv6/udp.c | 3 ++- 14 files changed, 47 insertions(+), 9 deletions(-) diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index ebe94f2..1d46adc 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -1206,6 +1206,13 @@ igmp_link_local_mcast_reports - BOOLEAN 224.0.0.X range. Default TRUE +stealth - BOOLEAN + Disable any reply not related to a listening socket, + like RST/ACK for TCP and ICMP Port-Unreachable for UDP. + Also disables ICMP replies to echo requests and timestamp + and ICMP errors for unknown protocols. + Default value is 0. +
Hmm, what about all other protocols besides TCP/UDP such as SCTP, DCCP, etc? It seems it gives false expectations in such cases when the user enables being "stealth", but finds out it has no effect at all there ... nmap f.e. has a couple of scanning options for SCTP, and at least SCTP is still relevant in telco space. I know this question has been asked before, but the only answer on this was so far: "well, I've never played with SCTP before" ... :/ -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
