ssl:setopts (keepalive)

gistfile1.txt

%% from /usr/include/netinet/in.h (Linux and OS X)
-define(IPPROTO_TCP, 6).

%% from /usr/include/netinet/tcp.h (Linux)
-define(TCP_MAXSEG, 2).
-define(TCP_KEEPIDLE, 4).
-define(TCP_KEEPINTVL, 5).
-define(TCP_KEEPCNT, 6).

%% @doc If you pass multiple raw options to ssl:listen, it appears to drop all
%% but one of them. Instead, we call setopts directly.
enable_keepalive(_Socket, []) ->
    ok;
enable_keepalive(Socket, [Opt = {keepalive, true}|Rest]) ->
    ssl:setopts(Socket, [Opt]),
    enable_keepalive(Socket, Rest);
enable_keepalive(Socket, [{keepalive_time, Secs}|Rest]) ->
    Opt = {raw, ?IPPROTO_TCP, ?TCP_KEEPIDLE, <<Secs:32/native>>},
    ssl:setopts(Socket, [Opt]),
    enable_keepalive(Socket, Rest);
enable_keepalive(Socket, [{keepalive_intvl, Secs}|Rest]) ->
    Opt = {raw, ?IPPROTO_TCP, ?TCP_KEEPINTVL, <<Secs:32/native>>},
    ssl:setopts(Socket, [Opt]),
    enable_keepalive(Socket, Rest);
enable_keepalive(Socket, [{keepalive_probes, Count}|Rest]) ->
    Opt = {raw, ?IPPROTO_TCP, ?TCP_KEEPCNT, <<Count:32/native>>},
    ssl:setopts(Socket, [Opt]),
    enable_keepalive(Socket, Rest);
enable_keepalive(Socket, [_|Rest]) ->
    enable_keepalive(Socket, Rest).