freebsd-dev/stand/lua/config.lua
Warner Losh e9eee0f256 lua: Export loaded modules env vars via environment
To make auditing and debugging easier, export foo_load=XXX foo_name=yyy
etc to the loader env that we export to the kernel.

Original by:		dhw
Sponsored by:		Netflix
Discussed with:		kevans
Differential Revsion:	https://reviews.freebsd.org/D38466
2023-02-09 11:56:20 -07:00

813 lines
21 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_FAILDIR = "Failed to load conf dir '%s': not a directory"
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_FAILPARSEVAR = "Failed to parse variable '%s': %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 MSG_FAILSYN_QUOTE = "Stray quote at position '%d'"
local MSG_FAILSYN_EOLESC = "Stray escape at end of line"
local MSG_FAILSYN_EOLVAR = "Unescaped $ at end of line"
local MSG_FAILSYN_BADVAR = "Malformed variable expression at position '%d'"
local MODULEEXPR = '([-%w_]+)'
local QVALEXPR = '"(.*)"'
local QVALREPL = QVALEXPR:gsub('%%', '%%%%')
local WORDEXPR = "([-%w%d][-%w%d_.]*)"
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
-- ${key} is a module name.
local function setKey(key, name, value)
if modules[key] == nil then
modules[key] = {}
end
modules[key][name] = value
end
-- Escapes the named value for use as a literal in a replacement pattern.
-- e.g. dhcp.host-name gets turned into dhcp%.host%-name to remove the special
-- meaning.
local function escapeName(name)
return name:gsub("([%p])", "%%%1")
end
local function processEnvVar(value)
local pval, vlen = '', #value
local nextpos, vdelim, vinit = 1
local vpat
for i = 1, vlen do
if i < nextpos then
goto nextc
end
local c = value:sub(i, i)
if c == '\\' then
if i == vlen then
return nil, MSG_FAILSYN_EOLESC
end
nextpos = i + 2
pval = pval .. value:sub(i + 1, i + 1)
elseif c == '"' then
return nil, MSG_FAILSYN_QUOTE:format(i)
elseif c == "$" then
if i == vlen then
return nil, MSG_FAILSYN_EOLVAR
else
if value:sub(i + 1, i + 1) == "{" then
-- Skip ${
vinit = i + 2
vdelim = '}'
vpat = "^([^}]+)}"
else
-- Skip the $
vinit = i + 1
vdelim = nil
vpat = "^([%w][-%w%d_.]*)"
end
local name = value:match(vpat, vinit)
if not name then
return nil, MSG_FAILSYN_BADVAR:format(i)
else
nextpos = vinit + #name
if vdelim then
nextpos = nextpos + 1
end
local repl = loader.getenv(name) or ""
pval = pval .. repl
end
end
else
pval = pval .. c
end
::nextc::
end
return pval
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()
setEnv(k .. "_load", v:upper())
end,
},
-- module_name="value"
{
str = MODULEEXPR .. "_name%s*=%s*$VALUE",
process = function(k, v)
setKey(k, "name", v)
setEnv(k .. "_name", v)
end,
},
-- module_type="value"
{
str = MODULEEXPR .. "_type%s*=%s*$VALUE",
process = function(k, v)
setKey(k, "type", v)
setEnv(k .. "_type", v)
end,
},
-- module_flags="value"
{
str = MODULEEXPR .. "_flags%s*=%s*$VALUE",
process = function(k, v)
setKey(k, "flags", v)
setEnv(k .. "_flags", v)
end,
},
-- module_before="value"
{
str = MODULEEXPR .. "_before%s*=%s*$VALUE",
process = function(k, v)
setKey(k, "before", v)
setEnv(k .. "_before", v)
end,
},
-- module_after="value"
{
str = MODULEEXPR .. "_after%s*=%s*$VALUE",
process = function(k, v)
setKey(k, "after", v)
setEnv(k .. "_after", v)
end,
},
-- module_error="value"
{
str = MODULEEXPR .. "_error%s*=%s*$VALUE",
process = function(k, v)
setKey(k, "error", v)
setEnv(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" or env_var=[word|num]
{
str = "([%w][%w%d-_.]*)%s*=%s*$VALUE",
process = function(k, v)
local pv, msg = processEnvVar(v)
if not pv then
print(MSG_FAILPARSEVAR:format(k, msg))
return
end
if setEnv(k, pv) ~= 0 then
print(MSG_FAILSETENV:format(k, v))
end
end,
},
}
local function isValidComment(line)
if line ~= nil then
local s = line:match("^%s*#.*")
if s == nil then
s = line:match("^%s*$")
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 not v.force and 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")
local nextboot_enable = loader.getenv("nextboot_enable")
if nextboot_file == nil then
return
end
-- is nextboot_enable set in nvstore?
if nextboot_enable == "NO" then
return
end
local text = readFile(nextboot_file, true)
if text == nil then
return
end
if nextboot_enable == nil and
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
loader.setenv("nextboot_enable", "NO")
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*$") == nil then
for _, val in ipairs(pattern_table) do
local pattern = '^%s*' .. val.str .. '%s*(.*)';
local cgroups = val.groups or 2
local k, v, c = checkPattern(line, pattern)
if k ~= nil then
-- Offset by one, drats
if cgroups == 1 then
c = v
v = nil
end
if isValidComment(c) then
val.process(k, v)
goto nextline
end
break
end
end
print(MSG_MALFORMED:format(n, line))
status = false
end
::nextline::
n = n + 1
end
return status
end
function config.readConf(file, loaded_files)
if loaded_files == nil then
loaded_files = {}
end
if loaded_files[file] ~= nil then
return
end
-- We'll process loader_conf_dirs at the top-level readConf
local load_conf_dirs = next(loaded_files) == nil
print("Loading " .. file)
-- The final value of loader_conf_files is not important, so just
-- clobber it here. We'll later check if it's no longer nil and process
-- the new value for files to read.
setEnv("loader_conf_files", nil)
-- These may or may not exist, and that's ok. Do a
-- silent parse so that we complain on parse errors but
-- not for them simply not existing.
if not config.processFile(file, true) then
print(MSG_FAILPARSECFG:format(file))
end
loaded_files[file] = true
-- Going to process "loader_conf_files" extra-files
local loader_conf_files = getEnv("loader_conf_files")
if loader_conf_files ~= nil then
for name in loader_conf_files:gmatch("[%w%p]+") do
config.readConf(name, loaded_files)
end
end
if load_conf_dirs then
local loader_conf_dirs = getEnv("loader_conf_dirs")
if loader_conf_dirs ~= nil then
for name in loader_conf_dirs:gmatch("[%w%p]+") do
if lfs.attributes(name, "mode") ~= "directory" then
print(MSG_FAILDIR:format(name))
goto nextdir
end
for cfile in lfs.dir(name) do
if cfile:match(".conf$") then
local fpath = name .. "/" .. cfile
if lfs.attributes(fpath, "mode") == "file" then
config.readConf(fpath, loaded_files)
end
end
end
::nextdir::
end
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
function config.enableModule(modname)
if modules[modname] == nil then
modules[modname] = {}
elseif modules[modname].load == "YES" then
modules[modname].force = true
return true
end
modules[modname].load = "YES"
modules[modname].force = true
return true
end
function config.disableModule(modname)
if modules[modname] == nil then
return false
elseif modules[modname].load ~= "YES" then
return true
end
modules[modname].load = "NO"
modules[modname].force = nil
return true
end
function config.isModuleEnabled(modname)
local mod = modules[modname]
if not mod or mod.load ~= "YES" then
return false
end
if mod.force then
return true
end
local blacklist = getBlacklist()
return not blacklist[modname]
end
function config.getModuleInfo()
return {
modules = modules,
blacklist = getBlacklist()
}
end
hook.registerType("config.loaded")
hook.registerType("config.reloaded")
hook.registerType("kernel.loaded")
hook.registerType("modules.loaded")
return config