mod_posix: Move everything to util.startup
This allows greater control over the order of events.
Notably, the internal ordering between daemonization, initialization of
libunbound and setup of signal handling is sensitive.
libunbound starts a separate thread for processing DNS requests.
If this thread is started before signal handling has been set up, it
will not inherit the signal handlers and instead behave as it would have
before signal handlers were set up, i.e. cause the whole process to
immediately exit.
libunbound is usually initialized on the first DNS request, usually
triggered by an outgoing s2s connection attempt.
If daemonization happens before signals have been set up, signals may
not be processed at all.
-- libunbound based net.adns replacement for Prosody IM
-- Copyright (C) 2012-2015 Kim Alvefur
-- Copyright (C) 2012 Waqas Hussain
--
-- This file is MIT licensed.
local setmetatable = setmetatable;
local table = table;
local t_concat = table.concat;
local t_insert = table.insert;
local s_byte = string.byte;
local s_format = string.format;
local s_sub = string.sub;
local iana_data = require "prosody.util.dnsregistry";
local tohex = require "prosody.util.hex".encode;
local inet_ntop = require "prosody.util.net".ntop;
-- Simplified versions of Waqas DNS parsers
-- Only the per RR parsers are needed and only feed a single RR
local parsers = {};
-- No support for pointers, but libunbound appears to take care of that.
local function readDnsName(packet, pos)
if s_byte(packet, pos) == 0 then return ".", pos+1; end
local pack_len, r, len = #packet, {};
pos = pos or 1;
repeat
len = s_byte(packet, pos) or 0;
t_insert(r, s_sub(packet, pos + 1, pos + len));
pos = pos + len + 1;
until len == 0 or pos >= pack_len;
return t_concat(r, "."), pos;
end
-- These are just simple names.
parsers.CNAME = readDnsName;
parsers.NS = readDnsName
parsers.PTR = readDnsName;
local soa_mt = {
__tostring = function(rr)
return s_format("%s %s %d %d %d %d %d", rr.mname, rr.rname, rr.serial, rr.refresh, rr.retry, rr.expire, rr.minimum);
end;
};
function parsers.SOA(packet)
local mname, rname, offset;
mname, offset = readDnsName(packet, 1);
rname, offset = readDnsName(packet, offset);
-- Extract all the bytes of these fields in one call
local
s1, s2, s3, s4, -- serial
r1, r2, r3, r4, -- refresh
t1, t2, t3, t4, -- retry
e1, e2, e3, e4, -- expire
m1, m2, m3, m4 -- minimum
= s_byte(packet, offset, offset + 19);
return setmetatable({
mname = mname;
rname = rname;
serial = s1*0x1000000 + s2*0x10000 + s3*0x100 + s4;
refresh = r1*0x1000000 + r2*0x10000 + r3*0x100 + r4;
retry = t1*0x1000000 + t2*0x10000 + t3*0x100 + t4;
expire = e1*0x1000000 + e2*0x10000 + e3*0x100 + e4;
minimum = m1*0x1000000 + m2*0x10000 + m3*0x100 + m4;
}, soa_mt);
end
parsers.A = inet_ntop;
parsers.AAAA = inet_ntop;
local mx_mt = {
__tostring = function(rr)
return s_format("%d %s", rr.pref, rr.mx)
end
};
function parsers.MX(packet)
local name = readDnsName(packet, 3);
local b1,b2 = s_byte(packet, 1, 2);
return setmetatable({
pref = b1*256+b2;
mx = name;
}, mx_mt);
end
local srv_mt = {
__tostring = function(rr)
return s_format("%d %d %d %s", rr.priority, rr.weight, rr.port, rr.target);
end
};
function parsers.SRV(packet)
local name = readDnsName(packet, 7);
local b1, b2, b3, b4, b5, b6 = s_byte(packet, 1, 6);
return setmetatable({
priority = b1*256+b2;
weight = b3*256+b4;
port = b5*256+b6;
target = name;
}, srv_mt);
end
local txt_mt = { __tostring = t_concat };
function parsers.TXT(packet)
local pack_len = #packet;
local r, pos, len = {}, 1;
repeat
len = s_byte(packet, pos) or 0;
t_insert(r, s_sub(packet, pos + 1, pos + len));
pos = pos + len + 1;
until pos >= pack_len;
return setmetatable(r, txt_mt);
end
parsers.SPF = parsers.TXT;
-- Acronyms from RFC 7218
local tlsa_usages = {
[0] = "PKIX-CA";
[1] = "PKIX-EE";
[2] = "DANE-TA";
[3] = "DANE-EE";
[255] = "PrivCert";
};
local tlsa_selectors = {
[0] = "Cert",
[1] = "SPKI",
[255] = "PrivSel",
};
local tlsa_match_types = {
[0] = "Full",
[1] = "SHA2-256",
[2] = "SHA2-512",
[255] = "PrivMatch",
};
local tlsa_mt = {
__tostring = function(rr)
return s_format("%s %s %s %s",
tlsa_usages[rr.use] or rr.use,
tlsa_selectors[rr.select] or rr.select,
tlsa_match_types[rr.match] or rr.match,
tohex(rr.data));
end;
__index = {
getUsage = function(rr) return tlsa_usages[rr.use] end;
getSelector = function(rr) return tlsa_selectors[rr.select] end;
getMatchType = function(rr) return tlsa_match_types[rr.match] end;
}
};
function parsers.TLSA(packet)
local use, select, match = s_byte(packet, 1,3);
return setmetatable({
use = use;
select = select;
match = match;
data = s_sub(packet, 4);
}, tlsa_mt);
end
local svcb_params = {"alpn"; "no-default-alpn"; "port"; "ipv4hint"; "ech"; "ipv6hint"};
setmetatable(svcb_params, {__index = function(_, n) return "key" .. tostring(n); end});
local svcb_mt = {
__tostring = function (rr)
local kv = {};
for i = 1, #rr.fields do
t_insert(kv, s_format("%s=%q", svcb_params[rr.fields[i].key], tostring(rr.fields[i].value)));
-- FIXME the =value part may be omitted when the value is "empty"
end
return s_format("%d %s %s", rr.prio, rr.name, t_concat(kv, " "));
end;
};
local svbc_ip_mt = {__tostring = function(ip) return t_concat(ip, ", "); end}
function parsers.SVCB(packet)
local prio_h, prio_l = packet:byte(1,2);
local prio = prio_h*256+prio_l;
local name, pos = readDnsName(packet, 3);
local fields = {};
while #packet > pos do
local key_h, key_l = packet:byte(pos+0,pos+1);
local len_h, len_l = packet:byte(pos+2,pos+3);
local key = key_h*256+key_l;
local len = len_h*256+len_l;
local value = packet:sub(pos+4,pos+4-1+len)
if key == 1 then
value = setmetatable(parsers.TXT(value), svbc_ip_mt);
elseif key == 3 then
local port_h, port_l = value:byte(1,2);
local port = port_h*256+port_l;
value = port;
elseif key == 4 then
local ip = {};
for i = 1, #value, 4 do
t_insert(ip, parsers.A(value:sub(i, i+3)));
end
value = setmetatable(ip, svbc_ip_mt);
elseif key == 6 then
local ip = {};
for i = 1, #value, 16 do
t_insert(ip, parsers.AAAA(value:sub(i, i+15)));
end
value = setmetatable(ip, svbc_ip_mt);
end
t_insert(fields, { key = key, value = value, len = len });
pos = pos+len+4;
end
return setmetatable({
prio = prio, name = name, fields = fields,
}, svcb_mt);
end
parsers.HTTPS = parsers.SVCB;
local params = {
TLSA = {
use = tlsa_usages;
select = tlsa_selectors;
match = tlsa_match_types;
};
};
local fallback_mt = {
__tostring = function(rr)
return s_format([[\# %d %s]], #rr.raw, tohex(rr.raw));
end;
};
local function fallback_parser(packet)
return setmetatable({ raw = packet },fallback_mt);
end
setmetatable(parsers, { __index = function() return fallback_parser end });
return {
parsers = parsers;
classes = iana_data.classes;
types = iana_data.types;
errors = iana_data.errors;
params = params;
};