net.server_epoll: Add support for systemd socket activation
Allows creating listening sockets and accepting client connections
before Prosody starts.
This is unlike normal Prosody dynamic resource management, where ports
may added and removed at any time, and the ports defined by the config.
Weird things happen if these are closed (e.g. due to reload) so here we
prevent closing and ensure sockets are reused when opened again.
local s_char = string.char;
local s_format = string.format;
local s_gsub = string.gsub;
local s_lower = string.lower;
local char_to_hex = {};
local hex_to_char = {};
do
local char, hex;
for i = 0,255 do
char, hex = s_char(i), s_format("%02x", i);
char_to_hex[char] = hex;
hex_to_char[hex] = char;
end
end
local function to(s)
return (s_gsub(s, ".", char_to_hex));
end
local function from(s)
return (s_gsub(s_lower(s), "%X*(%x%x)%X*", hex_to_char));
end
return {
encode = to, decode = from;
-- COMPAT w/pre-0.12:
to = to, from = from;
};