nimd/src/main.nim

96 lines
4.1 KiB
Nim

# Copyright 2021 Mattia Giambirtone & All Contributors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import parseopt
import strformat
import posix
import os
# NimD's own stuff
import util/[logging, constants, misc]
import core/mainloop
proc main(logger: Logger) =
## NimD's entry point
logger.debug("Starting NimD: A minimal, self-contained dependency-based Linux init system written in Nim")
logger.info(&"NimD version {NimdVersion.major}.{NimdVersion.minor}.{NimdVersion.patch} is starting up...")
logger.trace("Calling getCurrentProcessId()")
let pid = getCurrentProcessId()
logger.trace(&"getCurrentProcessId() returned {pid}")
if pid != 1:
logger.warning(&"Expecting to run as PID 1, but current process ID is {pid}")
logger.trace("Calling getuid()")
let uid = posix.getuid()
logger.trace(&"getuid() returned {uid}")
if uid != 0:
logger.fatal(&"NimD must run as root, but current user id is {uid}")
quit(EPERM) # EPERM - Operation not permitted
logger.debug("Setting up dummy signal handlers")
onSignal(SIGABRT, SIGALRM, SIGHUP, SIGILL, SIGKILL, SIGQUIT, SIGSTOP, SIGSEGV,
SIGTRAP, SIGTERM, SIGPIPE, SIGUSR1, SIGUSR2, 6, SIGFPE, SIGBUS, SIGURG, SIGINT): # 6 is SIGIOT
# Can't capture local variables because this implicitly generates
# a noconv procedure
getDefaultLogger().warning(&"Ignoring signal {sig} ({strsignal(sig)})") # Nim injects the variable "sig" into the scope. Gotta love those macros
logger.debug("Starting uninterruptible mainloop")
mainLoop(logger)
when isMainModule:
var logger = getDefaultLogger()
var optParser = initOptParser(commandLineParams())
for kind, key, value in optParser.getopt():
case kind:
of cmdArgument:
discard
of cmdLongOption:
case key:
of "help":
echo helpMessage
quit(0)
of "version":
echo NimDVersionString
quit(0)
of "verbose":
logger.setLevel(LogLevel.Debug)
of "extra":
logger.setLevel(LogLevel.Trace)
else:
logger.error(&"Unkown command-line long option '{key}'")
quit(EINVAL) # EINVAL - Invalid argument
of cmdShortOption:
case key:
of "h":
echo helpMessage
quit(0)
of "v":
echo NimDVersionString
quit(0)
of "V":
logger.setLevel(LogLevel.Debug)
of "X":
logger.setLevel(LogLevel.Trace)
else:
logger.error(&"Unkown command-line short option '{key}'")
quit(EINVAL) # EINVAL - Invalid argument
else:
echo "Usage: nimd [options]"
quit(EINVAL) # EINVAL - Invalid argument
logger.debug("Calling NimD entry point")
try:
main(logger)
except:
logger.fatal(&"A fatal unrecoverable error has occurred during startup and NimD cannot continue: {getCurrentExceptionMsg()}")
nimDExit(logger, 131) # ENOTRECOVERABLE - State not recoverable
# This will almost certainly cause the kernel to crash with an error the likes of "Kernel not syncing, attempted to kill init!",
# but, after all, there isn't much we can do if we can't even initialize *ourselves* is there?