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.
--
-- A string.format wrapper that gracefully handles invalid arguments since
-- certain format string and argument combinations may cause errors or other
-- issues like log spoofing
--
-- Provides some protection from e.g. CAPEC-135, CWE-117, CWE-134, CWE-93
local tostring = tostring;
local unpack = table.unpack;
local pack = table.pack;
local valid_utf8 = require "prosody.util.encodings".utf8.valid;
local type = type;
local dump = require"prosody.util.serialization".new({
preset = "compact";
fallback = function(v, why)
return "_[[" .. (why or tostring(v)) .. "]] ";
end;
freeze = true;
fatal = false;
maxdepth = 5;
});
local num_type = math.type;
-- In Lua 5.3+ these formats throw an error if given a float
local expects_integer = { c = true, d = true, i = true, o = true, u = true, X = true, x = true, };
-- In Lua 5.2 these throw an error given a negative number
local expects_positive = { o = true; u = true; x = true; X = true };
-- Printable Unicode replacements for control characters
local control_symbols = {
-- 0x00 .. 0x1F --> U+2400 .. U+241F, 0x7F --> U+2421
["\000"] = "\226\144\128", ["\001"] = "\226\144\129", ["\002"] = "\226\144\130",
["\003"] = "\226\144\131", ["\004"] = "\226\144\132", ["\005"] = "\226\144\133",
["\006"] = "\226\144\134", ["\007"] = "\226\144\135", ["\008"] = "\226\144\136",
["\009"] = "\226\144\137", ["\010"] = "\226\144\138", ["\011"] = "\226\144\139",
["\012"] = "\226\144\140", ["\013"] = "\226\144\141", ["\014"] = "\226\144\142",
["\015"] = "\226\144\143", ["\016"] = "\226\144\144", ["\017"] = "\226\144\145",
["\018"] = "\226\144\146", ["\019"] = "\226\144\147", ["\020"] = "\226\144\148",
["\021"] = "\226\144\149", ["\022"] = "\226\144\150", ["\023"] = "\226\144\151",
["\024"] = "\226\144\152", ["\025"] = "\226\144\153", ["\026"] = "\226\144\154",
["\027"] = "\226\144\155", ["\028"] = "\226\144\156", ["\029"] = "\226\144\157",
["\030"] = "\226\144\158", ["\031"] = "\226\144\159", ["\127"] = "\226\144\161",
};
local supports_p = pcall(string.format, "%p", ""); -- >= Lua 5.4
local function format(formatstring, ...)
local args = pack(...);
local args_length = args.n;
-- format specifier spec:
-- 1. Start: '%%'
-- 2. Flags: '[%-%+ #0]'
-- 3. Width: '%d?%d?'
-- 4. Precision: '%.?%d?%d?'
-- 5. Option: '[cdiouxXaAeEfgGqs%%]'
--
-- The options c, d, E, e, f, g, G, i, o, u, X, and x all expect a number as argument, whereas q and s expect a string.
-- This function does not accept string values containing embedded zeros, except as arguments to the q option.
-- a and A are only in Lua 5.2+
-- Lua 5.4 adds a p format that produces a pointer
-- process each format specifier
local i = 0;
formatstring = formatstring:gsub("%%[^cdiouxXaAeEfgGpqs%%]*[cdiouxXaAeEfgGpqs%%]", function(spec)
if spec == "%%" then return end
i = i + 1;
local arg = args[i];
if arg == nil then
args[i] = "nil";
return "(%s)";
end
local option = spec:sub(-1);
local t = type(arg);
if option == "s" and t == "string" and not arg:find("[%z\1-\31\128-\255]") then
-- No UTF-8 or control characters, assumed to be the common case.
return
elseif t == "number" then
if option == "g" or (option == "d" and num_type(arg) == "integer") then return end
elseif option == "s" and t ~= "string" then
arg = tostring(arg);
t = "string";
end
if option ~= "s" and option ~= "q" and option ~= "p" then
-- all other options expect numbers
if t ~= "number" then
-- arg isn't number as expected?
arg = tostring(arg);
option = "s";
spec = "[%s]";
t = "string";
elseif expects_integer[option] and num_type(arg) ~= "integer" then
args[i] = tostring(arg);
return "[%s]";
elseif expects_positive[option] and arg < 0 then
args[i] = tostring(arg);
return "[%s]";
else
return -- acceptable number
end
end
if option == "p" and not supports_p then
arg = tostring(arg);
option = "s";
spec = "[%s]";
t = "string";
end
if t == "string" and option ~= "p" then
if not valid_utf8(arg) then
option = "q";
elseif option ~= "q" then -- gets fully escaped in the next block
-- Prevent funny things with ASCII control characters and ANSI escape codes (CWE-117)
-- Also ensure embedded newlines can't look like another log line (CWE-93)
args[i] = arg:gsub("[%z\1-\8\11-\31\127]", control_symbols):gsub("\n\t?", "\n\t");
return spec;
end
end
if option == "q" then
args[i] = dump(arg);
return "%s";
end
if option == "p" and (t == "boolean" or t == "number") then
args[i] = tostring(arg);
return "[%s]";
end
end);
-- process extra args
while i < args_length do
i = i + 1;
local arg = args[i];
if arg == nil then
args[i] = "(nil)";
else
args[i] = tostring(arg):gsub("[%z\1-\8\11-\31\127]", control_symbols):gsub("\n\t?", "\n\t");
end
formatstring = formatstring .. " [%s]"
end
return formatstring:format(unpack(args));
end
return {
format = format;
};