dfhack/library/lua/binpatch.lua

130 lines
3.6 KiB
Lua

-- Simple binary patch with IDA dif file support.
local _ENV = mkmodule('binpatch')
local function load_patch(name)
local filename = name
if not string.match(filename, '[./\\]') then
filename = dfhack.getHackPath()..'/patches/'..dfhack.getDFVersion()..'/'..name..'.dif'
end
local file, err = io.open(filename, 'r')
if not file then
if string.match(err, ': No such file or directory') then
return nil, 'patch not found'
end
end
local old_bytes = {}
local new_bytes = {}
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local has_bytes = false
for line in file:lines() do
if string.match(line, '^%x+:') then
local offset, oldv, newv = string.match(line, '^(%x+):%s*(%x+)%s+(%x+)%s*$')
if not offset then
file:close()
return nil, 'could not parse: '..line
end
offset, oldv, newv = tonumber(offset,16), tonumber(oldv,16), tonumber(newv,16)
if oldv > 255 or newv > 255 then
file:close()
return nil, 'invalid byte values: '..line
end
old_bytes[offset] = oldv
new_bytes[offset] = newv
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has_bytes = true
end
end
file:close()
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if not has_bytes then
return nil, 'no patch bytes found'
end
return { name = name, old_bytes = old_bytes, new_bytes = new_bytes }
end
local function rebase_table(input)
local output = {}
local base = dfhack.internal.getImageBase()
for k,v in pairs(input) do
local offset = dfhack.internal.adjustOffset(k)
if not offset then
return nil, string.format('invalid offset: %x', k)
end
output[base + offset] = v
end
return output
end
local function rebase_patch(patch)
local nold, err = rebase_table(patch.old_bytes)
if not nold then return nil, err end
local nnew, err = rebase_table(patch.new_bytes)
if not nnew then return nil, err end
return { name = patch.name, old_bytes = nold, new_bytes = nnew }
end
BinaryPatch = defclass(BinaryPatch)
BinaryPatch.ATTRS {
name = DEFAULT_NIL,
old_bytes = DEFAULT_NIL,
new_bytes = DEFAULT_NIL,
}
function load_dif_file(name)
local patch, err = load_patch(name)
if not patch then return nil, err end
local rpatch, err = rebase_patch(patch)
if not rpatch then return nil, err end
return BinaryPatch(rpatch)
end
function BinaryPatch:status()
local old_ok, err, addr = dfhack.internal.patchBytes({}, self.old_bytes)
if old_ok then
return 'removed'
elseif dfhack.internal.patchBytes({}, self.new_bytes) then
return 'applied'
else
return 'conflict', addr
end
end
function BinaryPatch:isApplied()
return dfhack.internal.patchBytes({}, self.new_bytes)
end
function BinaryPatch:apply()
local ok, err, addr = dfhack.internal.patchBytes(self.new_bytes, self.old_bytes)
if ok then
return true, 'applied the patch'
elseif dfhack.internal.patchBytes({}, self.new_bytes) then
return true, 'patch is already applied'
else
return false, string.format('conflict at address %x', addr)
end
end
function BinaryPatch:isRemoved()
return dfhack.internal.patchBytes({}, self.old_bytes)
end
function BinaryPatch:remove()
local ok, err, addr = dfhack.internal.patchBytes(self.old_bytes, self.new_bytes)
if ok then
return true, 'removed the patch'
elseif dfhack.internal.patchBytes({}, self.old_bytes) then
return true, 'patch is already removed'
else
return false, string.format('conflict at address %x', addr)
end
end
return _ENV