freebsd-dev/stand/lua/config.lua
Kyle Evans 3fe0ac6aa5 lualoader: config: improve readConfFiles, rename to readConf
The previous interface was pretty bad, and required the caller to get some
implementation details correct that it really shouldn't need to (e.g.
loader_conf_files handling) and pass in an empty table for it to use.

The new and much improved interface, readConf, is much less of a hack;
hiding these implementation details and just doing the right thing.
config.lua will now use it to process /boot/defaults/loader.conf and the
subsequent loader_conf_files from there, and read-conf will also use it.

This improvement submitted by Olivier (cited below), loader_conf_files
handling from the original patch was changed to just clobber it before
processing and not bother restoring it after the fact following r360505
where it's now guaranteed to evade the loader environment.

PR:		244640
Submitted by:	Olivier Certner (olivier freebsd free fr>
2020-04-30 21:04:39 +00:00

681 lines
18 KiB
Lua

--
-- SPDX-License-Identifier: BSD-2-Clause-FreeBSD
--
-- Copyright (c) 2015 Pedro Souza <pedrosouza@freebsd.org>
-- Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org>
-- All rights reserved.
--
-- Redistribution and use in source and binary forms, with or without
-- modification, are permitted provided that the following conditions
-- are met:
-- 1. Redistributions of source code must retain the above copyright
-- notice, this list of conditions and the following disclaimer.
-- 2. Redistributions in binary form must reproduce the above copyright
-- notice, this list of conditions and the following disclaimer in the
-- documentation and/or other materials provided with the distribution.
--
-- THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
-- ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-- IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-- ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
-- FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-- DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
-- OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
-- HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-- LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-- OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-- SUCH DAMAGE.
--
-- $FreeBSD$
--
local hook = require("hook")
local config = {}
local modules = {}
local carousel_choices = {}
-- Which variables we changed
local env_changed = {}
-- Values to restore env to (nil to unset)
local env_restore = {}
local MSG_FAILEXEC = "Failed to exec '%s'"
local MSG_FAILSETENV = "Failed to '%s' with value: %s"
local MSG_FAILOPENCFG = "Failed to open config: '%s'"
local MSG_FAILREADCFG = "Failed to read config: '%s'"
local MSG_FAILPARSECFG = "Failed to parse config: '%s'"
local MSG_FAILEXBEF = "Failed to execute '%s' before loading '%s'"
local MSG_FAILEXAF = "Failed to execute '%s' after loading '%s'"
local MSG_MALFORMED = "Malformed line (%d):\n\t'%s'"
local MSG_DEFAULTKERNFAIL = "No kernel set, failed to load from module_path"
local MSG_KERNFAIL = "Failed to load kernel '%s'"
local MSG_XENKERNFAIL = "Failed to load Xen kernel '%s'"
local MSG_XENKERNLOADING = "Loading Xen kernel..."
local MSG_KERNLOADING = "Loading kernel..."
local MSG_MODLOADING = "Loading configured modules..."
local MSG_MODBLACKLIST = "Not loading blacklisted module '%s'"
local MODULEEXPR = '([%w-_]+)'
local QVALEXPR = "\"([%w%s%p]-)\""
local QVALREPL = QVALEXPR:gsub('%%', '%%%%')
local WORDEXPR = "([%w]+)"
local WORDREPL = WORDEXPR:gsub('%%', '%%%%')
-- Entries that should never make it into the environment; each one should have
-- a documented reason for its existence, and these should all be implementation
-- details of the config module.
local loader_env_restricted_table = {
-- loader_conf_files should be considered write-only, and consumers
-- should not rely on any particular value; it's a loader implementation
-- detail. Moreover, it's not a particularly useful variable to have in
-- the kenv. Save the overhead, let it get fetched other ways.
loader_conf_files = true,
}
local function restoreEnv()
-- Examine changed environment variables
for k, v in pairs(env_changed) do
local restore_value = env_restore[k]
if restore_value == nil then
-- This one doesn't need restored for some reason
goto continue
end
local current_value = loader.getenv(k)
if current_value ~= v then
-- This was overwritten by some action taken on the menu
-- most likely; we'll leave it be.
goto continue
end
restore_value = restore_value.value
if restore_value ~= nil then
loader.setenv(k, restore_value)
else
loader.unsetenv(k)
end
::continue::
end
env_changed = {}
env_restore = {}
end
-- XXX This getEnv/setEnv should likely be exported at some point. We can save
-- the call back into loader.getenv for any variable that's been set or
-- overridden by any loader.conf using this implementation with little overhead
-- since we're already tracking the values.
local function getEnv(key)
if loader_env_restricted_table[key] ~= nil or
env_changed[key] ~= nil then
return env_changed[key]
end
return loader.getenv(key)
end
local function setEnv(key, value)
env_changed[key] = value
if loader_env_restricted_table[key] ~= nil then
return 0
end
-- Track the original value for this if we haven't already
if env_restore[key] == nil then
env_restore[key] = {value = loader.getenv(key)}
end
return loader.setenv(key, value)
end
-- name here is one of 'name', 'type', flags', 'before', 'after', or 'error.'
-- These are set from lines in loader.conf(5): ${key}_${name}="${value}" where
-- ${key} is a module name.
local function setKey(key, name, value)
if modules[key] == nil then
modules[key] = {}
end
modules[key][name] = value
end
-- Escapes the named value for use as a literal in a replacement pattern.
-- e.g. dhcp.host-name gets turned into dhcp%.host%-name to remove the special
-- meaning.
local function escapeName(name)
return name:gsub("([%p])", "%%%1")
end
local function processEnvVar(value)
for name in value:gmatch("${([^}]+)}") do
local replacement = loader.getenv(name) or ""
value = value:gsub("${" .. escapeName(name) .. "}", replacement)
end
for name in value:gmatch("$([%w%p]+)%s*") do
local replacement = loader.getenv(name) or ""
value = value:gsub("$" .. escapeName(name), replacement)
end
return value
end
local function checkPattern(line, pattern)
local function _realCheck(_line, _pattern)
return _line:match(_pattern)
end
if pattern:find('$VALUE') then
local k, v, c
k, v, c = _realCheck(line, pattern:gsub('$VALUE', QVALREPL))
if k ~= nil then
return k,v, c
end
return _realCheck(line, pattern:gsub('$VALUE', WORDREPL))
else
return _realCheck(line, pattern)
end
end
-- str in this table is a regex pattern. It will automatically be anchored to
-- the beginning of a line and any preceding whitespace will be skipped. The
-- pattern should have no more than two captures patterns, which correspond to
-- the two parameters (usually 'key' and 'value') that are passed to the
-- process function. All trailing characters will be validated. Any $VALUE
-- token included in a pattern will be tried first with a quoted value capture
-- group, then a single-word value capture group. This is our kludge for Lua
-- regex not supporting branching.
--
-- We have two special entries in this table: the first is the first entry,
-- a full-line comment. The second is for 'exec' handling. Both have a single
-- capture group, but the difference is that the full-line comment pattern will
-- match the entire line. This does not run afoul of the later end of line
-- validation that we'll do after a match. However, the 'exec' pattern will.
-- We document the exceptions with a special 'groups' index that indicates
-- the number of capture groups, if not two. We'll use this later to do
-- validation on the proper entry.
--
local pattern_table = {
{
str = "(#.*)",
process = function(_, _) end,
groups = 1,
},
-- module_load="value"
{
str = MODULEEXPR .. "_load%s*=%s*$VALUE",
process = function(k, v)
if modules[k] == nil then
modules[k] = {}
end
modules[k].load = v:upper()
end,
},
-- module_name="value"
{
str = MODULEEXPR .. "_name%s*=%s*$VALUE",
process = function(k, v)
setKey(k, "name", v)
end,
},
-- module_type="value"
{
str = MODULEEXPR .. "_type%s*=%s*$VALUE",
process = function(k, v)
setKey(k, "type", v)
end,
},
-- module_flags="value"
{
str = MODULEEXPR .. "_flags%s*=%s*$VALUE",
process = function(k, v)
setKey(k, "flags", v)
end,
},
-- module_before="value"
{
str = MODULEEXPR .. "_before%s*=%s*$VALUE",
process = function(k, v)
setKey(k, "before", v)
end,
},
-- module_after="value"
{
str = MODULEEXPR .. "_after%s*=%s*$VALUE",
process = function(k, v)
setKey(k, "after", v)
end,
},
-- module_error="value"
{
str = MODULEEXPR .. "_error%s*=%s*$VALUE",
process = function(k, v)
setKey(k, "error", v)
end,
},
-- exec="command"
{
str = "exec%s*=%s*" .. QVALEXPR,
process = function(k, _)
if cli_execute_unparsed(k) ~= 0 then
print(MSG_FAILEXEC:format(k))
end
end,
groups = 1,
},
-- env_var="value"
{
str = "([%w%p]+)%s*=%s*$VALUE",
process = function(k, v)
if setEnv(k, processEnvVar(v)) ~= 0 then
print(MSG_FAILSETENV:format(k, v))
end
end,
},
-- env_var=num
{
str = "([%w%p]+)%s*=%s*(-?%d+)",
process = function(k, v)
if setEnv(k, processEnvVar(v)) ~= 0 then
print(MSG_FAILSETENV:format(k, tostring(v)))
end
end,
},
}
local function isValidComment(line)
if line ~= nil then
local s = line:match("^%s*#.*")
if s == nil then
s = line:match("^%s*$")
end
if s == nil then
return false
end
end
return true
end
local function getBlacklist()
local blacklist = {}
local blacklist_str = loader.getenv('module_blacklist')
if blacklist_str == nil then
return blacklist
end
for mod in blacklist_str:gmatch("[;, ]?([%w-_]+)[;, ]?") do
blacklist[mod] = true
end
return blacklist
end
local function loadModule(mod, silent)
local status = true
local blacklist = getBlacklist()
local pstatus
for k, v in pairs(mod) do
if v.load ~= nil and v.load:lower() == "yes" then
local module_name = v.name or k
if blacklist[module_name] ~= nil then
if not silent then
print(MSG_MODBLACKLIST:format(module_name))
end
goto continue
end
if not silent then
loader.printc(module_name .. "...")
end
local str = "load "
if v.type ~= nil then
str = str .. "-t " .. v.type .. " "
end
str = str .. module_name
if v.flags ~= nil then
str = str .. " " .. v.flags
end
if v.before ~= nil then
pstatus = cli_execute_unparsed(v.before) == 0
if not pstatus and not silent then
print(MSG_FAILEXBEF:format(v.before, k))
end
status = status and pstatus
end
if cli_execute_unparsed(str) ~= 0 then
-- XXX Temporary shim: don't break the boot if
-- loader hadn't been recompiled with this
-- function exposed.
if loader.command_error then
print(loader.command_error())
end
if not silent then
print("failed!")
end
if v.error ~= nil then
cli_execute_unparsed(v.error)
end
status = false
elseif v.after ~= nil then
pstatus = cli_execute_unparsed(v.after) == 0
if not pstatus and not silent then
print(MSG_FAILEXAF:format(v.after, k))
end
if not silent then
print("ok")
end
status = status and pstatus
end
end
::continue::
end
return status
end
local function readFile(name, silent)
local f = io.open(name)
if f == nil then
if not silent then
print(MSG_FAILOPENCFG:format(name))
end
return nil
end
local text, _ = io.read(f)
-- We might have read in the whole file, this won't be needed any more.
io.close(f)
if text == nil and not silent then
print(MSG_FAILREADCFG:format(name))
end
return text
end
local function checkNextboot()
local nextboot_file = loader.getenv("nextboot_conf")
if nextboot_file == nil then
return
end
local text = readFile(nextboot_file, true)
if text == nil then
return
end
if text:match("^nextboot_enable=\"NO\"") ~= nil then
-- We're done; nextboot is not enabled
return
end
if not config.parse(text) then
print(MSG_FAILPARSECFG:format(nextboot_file))
end
-- Attempt to rewrite the first line and only the first line of the
-- nextboot_file. We overwrite it with nextboot_enable="NO", then
-- check for that on load.
-- It's worth noting that this won't work on every filesystem, so we
-- won't do anything notable if we have any errors in this process.
local nfile = io.open(nextboot_file, 'w')
if nfile ~= nil then
-- We need the trailing space here to account for the extra
-- character taken up by the string nextboot_enable="YES"
-- Or new end quotation mark lands on the S, and we want to
-- rewrite the entirety of the first line.
io.write(nfile, "nextboot_enable=\"NO\" ")
io.close(nfile)
end
end
-- Module exports
config.verbose = false
-- The first item in every carousel is always the default item.
function config.getCarouselIndex(id)
return carousel_choices[id] or 1
end
function config.setCarouselIndex(id, idx)
carousel_choices[id] = idx
end
-- Returns true if we processed the file successfully, false if we did not.
-- If 'silent' is true, being unable to read the file is not considered a
-- failure.
function config.processFile(name, silent)
if silent == nil then
silent = false
end
local text = readFile(name, silent)
if text == nil then
return silent
end
return config.parse(text)
end
-- silent runs will not return false if we fail to open the file
function config.parse(text)
local n = 1
local status = true
for line in text:gmatch("([^\n]+)") do
if line:match("^%s*$") == nil then
for _, val in ipairs(pattern_table) do
local pattern = '^%s*' .. val.str .. '%s*(.*)';
local cgroups = val.groups or 2
local k, v, c = checkPattern(line, pattern)
if k ~= nil then
-- Offset by one, drats
if cgroups == 1 then
c = v
v = nil
end
if isValidComment(c) then
val.process(k, v)
goto nextline
end
break
end
end
print(MSG_MALFORMED:format(n, line))
status = false
end
::nextline::
n = n + 1
end
return status
end
function config.readConf(file, loaded_files)
if loaded_files == nil then
loaded_files = {}
end
if loaded_files[file] ~= nil then
return
end
print("Loading " .. file)
-- The final value of loader_conf_files is not important, so just
-- clobber it here. We'll later check if it's no longer nil and process
-- the new value for files to read.
setEnv("loader_conf_files", nil)
-- These may or may not exist, and that's ok. Do a
-- silent parse so that we complain on parse errors but
-- not for them simply not existing.
if not config.processFile(file, true) then
print(MSG_FAILPARSECFG:format(file))
end
loaded_files[file] = true
-- Going to process "loader_conf_files" extra-files
local loader_conf_files = getEnv("loader_conf_files")
if loader_conf_files ~= nil then
for name in loader_conf_files:gmatch("[%w%p]+") do
config.readConf(name, loaded_files)
end
end
end
-- other_kernel is optionally the name of a kernel to load, if not the default
-- or autoloaded default from the module_path
function config.loadKernel(other_kernel)
local flags = loader.getenv("kernel_options") or ""
local kernel = other_kernel or loader.getenv("kernel")
local function tryLoad(names)
for name in names:gmatch("([^;]+)%s*;?") do
local r = loader.perform("load " .. name ..
" " .. flags)
if r == 0 then
return name
end
end
return nil
end
local function getModulePath()
local module_path = loader.getenv("module_path")
local kernel_path = loader.getenv("kernel_path")
if kernel_path == nil then
return module_path
end
-- Strip the loaded kernel path from module_path. This currently assumes
-- that the kernel path will be prepended to the module_path when it's
-- found.
kernel_path = escapeName(kernel_path .. ';')
return module_path:gsub(kernel_path, '')
end
local function loadBootfile()
local bootfile = loader.getenv("bootfile")
-- append default kernel name
if bootfile == nil then
bootfile = "kernel"
else
bootfile = bootfile .. ";kernel"
end
return tryLoad(bootfile)
end
-- kernel not set, try load from default module_path
if kernel == nil then
local res = loadBootfile()
if res ~= nil then
-- Default kernel is loaded
config.kernel_loaded = nil
return true
else
print(MSG_DEFAULTKERNFAIL)
return false
end
else
-- Use our cached module_path, so we don't end up with multiple
-- automatically added kernel paths to our final module_path
local module_path = getModulePath()
local res
if other_kernel ~= nil then
kernel = other_kernel
end
-- first try load kernel with module_path = /boot/${kernel}
-- then try load with module_path=${kernel}
local paths = {"/boot/" .. kernel, kernel}
for _, v in pairs(paths) do
loader.setenv("module_path", v)
res = loadBootfile()
-- succeeded, add path to module_path
if res ~= nil then
config.kernel_loaded = kernel
if module_path ~= nil then
loader.setenv("module_path", v .. ";" ..
module_path)
loader.setenv("kernel_path", v)
end
return true
end
end
-- failed to load with ${kernel} as a directory
-- try as a file
res = tryLoad(kernel)
if res ~= nil then
config.kernel_loaded = kernel
return true
else
print(MSG_KERNFAIL:format(kernel))
return false
end
end
end
function config.selectKernel(kernel)
config.kernel_selected = kernel
end
function config.load(file, reloading)
if not file then
file = "/boot/defaults/loader.conf"
end
config.readConf(file)
checkNextboot()
local verbose = loader.getenv("verbose_loading") or "no"
config.verbose = verbose:lower() == "yes"
if not reloading then
hook.runAll("config.loaded")
end
end
-- Reload configuration
function config.reload(file)
modules = {}
restoreEnv()
config.load(file, true)
hook.runAll("config.reloaded")
end
function config.loadelf()
local xen_kernel = loader.getenv('xen_kernel')
local kernel = config.kernel_selected or config.kernel_loaded
local status
if xen_kernel ~= nil then
print(MSG_XENKERNLOADING)
if cli_execute_unparsed('load ' .. xen_kernel) ~= 0 then
print(MSG_XENKERNFAIL:format(xen_kernel))
return false
end
end
print(MSG_KERNLOADING)
if not config.loadKernel(kernel) then
return false
end
hook.runAll("kernel.loaded")
print(MSG_MODLOADING)
status = loadModule(modules, not config.verbose)
hook.runAll("modules.loaded")
return status
end
hook.registerType("config.loaded")
hook.registerType("config.reloaded")
hook.registerType("kernel.loaded")
hook.registerType("modules.loaded")
return config