xref: /src/etc/rc

#!/bin/sh
#
# $NetBSD: rc,v 1.175 2020/09/08 16:10:53 martin Exp $
#
# rc --
#	Run the scripts in /etc/rc.d with rcorder, and log output
#	to /var/run/rc.log.

#	System startup script run by init(8) on autoboot or after single-user.
#	Output and error are redirected to console by init, and the console
#	is the controlling terminal.

export HOME=/
export PATH=/sbin:/bin:/usr/sbin:/usr/bin
umask 022

if [ -e ./rc.subr ] ; then
	. ./rc.subr # for testing
else
	. /etc/rc.subr
fi
. /etc/rc.conf
_rc_conf_loaded=true

: ${RC_LOG_FILE:="/var/run/rc.log"}

# rc.subr redefines echo and printf.  Undo that here.
unset echo ; unalias echo
unset printf ; unalias printf

if ! checkyesno rc_configured; then
	echo "/etc/rc.conf is not configured.  Multiuser boot aborted."
	exit 1
fi

if [ "$1" = autoboot ]; then
	autoboot=yes
	rc_fast=yes	# run_rc_command(): do fast booting
fi

#
# Completely ignore INT and QUIT at the outer level.  The rc_real_work()
# function should do something different.
#
trap '' INT QUIT

#
# This string will be used to mark lines of meta-data sent over the pipe
# from the rc_real_work() function to the rc_postprocess() function.  Lines
# not so marked are assumed to be output from rc.d scripts.
#
# This string is long and unique to ensure that it does not accidentally
# appear in output from any rc.d script.  It must not contain any
# characters that are special to glob expansion ('*', '?', '[', or ']').
#
rc_metadata_prefix="$0:$$:metadata:";

# Child scripts may sometimes want to print directly to the original
# stdout and stderr, bypassing the pipe to the postprocessor.  These
# _rc_*_fd variables are private, shared with /etc/rc.subr, but not
# intended to be used directly by child scripts.  (Child scripts
# may use rc.subr's no_rc_postprocess function.)
#
_rc_original_stdout_fd=7; export _rc_original_stdout_fd
_rc_original_stderr_fd=8; export _rc_original_stderr_fd
eval "exec ${_rc_original_stdout_fd}>&1"
eval "exec ${_rc_original_stderr_fd}>&2"
fdflags -s +cloexec 7 8

#
# rc_real_work
#	Do the real work.  Output from this function will be piped into
#	rc_postprocess(), and some of the output will be marked as
#	metadata.
#
# The body of this function is defined using (...), not {...}, to force
# it to run in a subshell.
#
rc_real_work()
(
	stty status '^T'

	# print_rc_metadata() wants to be able to print to the pipe
	# that goes to our postprocessor, even if its in a context
	# with redirected output.
	#
	_rc_postprocessor_fd=9 ; export _rc_postprocessor_fd
	_rc_pid=$$ ; export _rc_pid
	eval "exec ${_rc_postprocessor_fd}>&1"
	fdflags -s +cloexec 9

	# Print a metadata line when we exit
	#
	trap 'es=$?; print_rc_metadata "exit:$es"; trap "" 0; exit $es' 0

	#	Set shell to ignore SIGINT, but children will not ignore it.
	#	Shell catches SIGQUIT and returns to single user.
	#
	trap : INT
	trap '_msg="Boot interrupted at $(date)";
	      print_rc_metadata "interrupted:${_msg}";
	      exit 1' QUIT

	print_rc_metadata "start:$(date)"

	#
	# The stop_boot() function in rc.subr may kill $RC_PID.  We want
	# it to kill the subshell running this rc_real_work() function,
	# rather than killing the parent shell, because we want the
	# rc_postprocess() function to be able to log the error
	# without being killed itself.
	#
	# "$$" is the pid of the top-level shell, not the pid of the
	# subshell that's executing this function.  The command below
	# tentatively assumes that the parent of the "/bin/sh -c ..."
	# process will be the current subshell, and then uses "kill -0
	# ..." to check the result.  If the "/bin/sh -c ..." process
	# fails, or returns the pid of an ephemeral process that exits
	# before the "kill" command, then we fall back to using "$$".
	#
	RC_PID=$(/bin/sh -c 'ps -p $$ -o ppid=') || RC_PID=$$
	kill -0 $RC_PID >/dev/null 2>&1 || RC_PID=$$

	#
	# As long as process $RC_PID is still running, send a "nop"
	# metadata message to the postprocessor every few seconds.
	# This should help flush partial lines that may appear when
	# rc.d scripts that are NOT marked with "KEYWORD: interactive"
	# nevertheless attempt to print prompts and wait for input.
	#
	(
	    # First detach from tty, to avoid intercepting SIGINFO.
	    eval "exec ${_rc_original_stdout_fd}<&-"
	    eval "exec ${_rc_original_stderr_fd}<&-"
	    exec </dev/null >/dev/null 2>&1
	    while kill -0 $RC_PID ; do
		print_rc_metadata "nop"
		sleep 3
	    done
	) &

	#
	# Get a list of all rc.d scripts, and use rcorder to choose
	# what order to execute them.
	#
	# For testing, allow RC_FILES_OVERRIDE from the environment to
	# override this.
	#
	print_rc_metadata "cmd-name:rcorder"
	scripts=$(for rcd in ${rc_directories:-/etc/rc.d}; do
		test -d ${rcd} && echo ${rcd}/*;
	done)
	files=$(rcorder -s nostart ${rc_rcorder_flags} ${scripts})
	print_rc_metadata "cmd-status:rcorder:$?"

	if [ -n "${RC_FILES_OVERRIDE}" ]; then
		files="${RC_FILES_OVERRIDE}"
	fi

	#
	# Run the scripts in order.
	#
	for _rc_elem in $files; do
		print_rc_metadata "cmd-name:$_rc_elem"
		run_rc_script $_rc_elem start
		print_rc_metadata "cmd-status:$_rc_elem:$?"
	done

	print_rc_metadata "end:$(date)"
	exit 0
)

#
# rc_postprocess
#	Post-process the output from the rc_real_work() function.  For
#	each line of input, we have to decide whether to print the line
#	to the console, print a twiddle on the console, print a line to
#	the log, or some combination of these.
#
#	If rc_silent is true, then suppress most output, instead running
#	rc_silent_cmd (typically "twiddle") for each line.
#
# The body of this function is defined using (...), not {...}, to force
# it to run in a subshell.
#
# We have to deal with the following constraints:
#
#  * There may be no writable file systems early in the boot, so
#    any use of temporary files would be problematic.
#
#  * Scripts run during the boot may clear /tmp and/var/run, so even
#    if they are writable, using those directories too early may be
#    problematic.  We assume that it's safe to write to our log file
#    after the CRITLOCALMOUNTED script has run.
#
#  * /usr/bin/tee cannot be used because the /usr file system may not
#    be mounted early in the boot.
#
#  * All calls to the rc_log_message and rc_log_flush functions must be
#    from the same subshell, otherwise the use of a shell variable to
#    buffer log messages will fail.
#
rc_postprocess()
(
	local line
	local before after
	local IFS=''

	# Try quite hard to flush the log to disk when we exit.
	trap 'es=$?; rc_log_flush FORCE; trap "" 0; exit $es' 0

	yesno_to_truefalse rc_silent 2>/dev/null

	while read -r line ; do
		case "$line" in
		"${rc_metadata_prefix}"*)
			after="${line#*"${rc_metadata_prefix}"}"
			rc_postprocess_metadata "${after}"
			;;
		*"${rc_metadata_prefix}"*)
			# magic string is present, but not at the start of
			# the line.  Treat it as a partial line of
			# ordinary data, followed by a line of metadata.
			before="${line%"${rc_metadata_prefix}"*}"
			rc_postprocess_partial_line "${before}"
			after="${line#*"${rc_metadata_prefix}"}"
			rc_postprocess_metadata "${after}"
			;;
		*)
			rc_postprocess_plain_line "${line}"
			;;
		esac
	done

	# If we get here, then the rc_real_work() function must have
	# exited uncleanly.  A clean exit would have been accompanied by
	# a line of metadata that would have prevented us from getting
	# here.
	#
	exit 1
)

#
# rc_postprocess_plain_line string
#	$1 is a string representing a line of output from one of the
#	rc.d scripts.  Append the line to the log, and also either
#	display the line on the console, or run $rc_silent_cmd,
#	depending on the value of $rc_silent.
#
rc_postprocess_plain_line()
{
	local line="$1"
	rc_log_message "${line}"
	if $rc_silent; then
		eval "$rc_silent_cmd"
	else
		printf "%s\n" "${line}"
	fi
}

#
# rc_postprocess_partial_line string
#	This is just like rc_postprocess_plain_line, except that
#	a newline is not appended to the string.
#
rc_postprocess_partial_line()
{
	local line="$1"
	rc_log_message_n "${line}"
	if $rc_silent; then
		eval "$rc_silent_cmd"
	else
		printf "%s" "${line}"
	fi
}

#
# rc_postprocess_metadata string
#	$1 is a string containing metadata from the rc_real_work()
#	function.  The rc_metadata_prefix marker should already
#	have been removed before the string is passed to this function.
#	Take appropriate action depending on the content of the string.
#
rc_postprocess_metadata()
{
	local metadata="$1"
	local keyword args
	local msg
	local IFS=':'

	# given metadata="bleep:foo bar:baz",
	# set keyword="bleep", args="foo bar:baz",
	# $1="foo bar", $2="baz"
	#
	keyword="${metadata%%:*}"
	args="${metadata#*:}"
	set -- $args

	case "$keyword" in
	start)
		# Marks the start of the entire /etc/rc script.
		# $args contains a date/time.
		rc_log_message "[$0 starting at $args]"
		if ! $rc_silent; then
			printf "%s\n" "$args"
		fi
		;;
	cmd-name)
		# Marks the start of a child script (usually one of
		# the /etc/rc.d/* scripts).
		rc_log_message "[running $1]"
		;;
	cmd-status)
		# Marks the end of a child script.
		# $1 is a command name, $2 is the command's exit status.
		# If the command failed, report it, and add it to a list.
		if [ "$2" != 0 ]; then
			rc_failures="${rc_failures}${rc_failures:+ }$1"
			msg="$1 $(human_exit_code $2)"
			rc_log_message "$msg"
			if ! $rc_silent; then
				printf "%s\n" "$msg"
			fi
		fi
		# After the CRITLOCALMOUNTED script has finished, it's
		# OK to flush the log to disk
		case "$1" in
		*/CRITLOCALMOUNTED)
			rc_log_flush OK
			;;
		esac
		;;
	nop)
		# Do nothing.
		# This has the side effect of flushing partial lines,
		# and the echo() and printf() functions in rc.subr take
		# advantage of this.
		;;
	note)
		# Unlike most metadata messages, which should be used
		# only by /etc/rc and rc.subr, the "note" message may be
		# used directly by /etc.rc.d/* and similar scripts.
		# It adds a note to the log file, without displaying
		# it to stdout.
		rc_log_message "[NOTE: $args]"
		;;
	end)
		# Marks the end of processing, after the last child script.
		# If any child scripts (or other commands) failed, report them.
		#
		if [ -n "$rc_failures" ]; then
			rc_log_message "[failures]"
			msg="The following components reported failures:"
			msg="${msg}${nl}$( echo "    ${rc_failures}" | fmt )"
			msg="${msg}${nl}See ${RC_LOG_FILE} for more information."
			rc_log_message "${msg}"
			printf "%s\n" "${msg}"
		fi
		#
		# Report the end date/time, even in silent mode
		#
		rc_log_message "[$0 finished at $args]"
		printf "%s\n" "$args"
		;;
	exit)
		# Marks an exit from the rc_real_work() function.
		# This may be a normal or abnormal exit.
		#
		rc_log_message "[$0 exiting with status $1]"
		exit $1
		;;
	interrupted)
		# Marks an interrupt trapped by the rc_real_work() function.
		# $args is a human-readable message.
		rc_log_message "$args"
		printf "%s\n" "$args"
		;;
	*)
		# an unrecognised line of metadata
		rc_log_message "[metadata:${metadata}]"
		;;
	esac
}

#
# rc_log_message string [...]
#	Write a message to the log file, or buffer it for later.
#	This function appends a newline to the message.
#
rc_log_message()
{
	_rc_log_buffer="${_rc_log_buffer}${*}${nl}"
	rc_log_flush
}

#
# rc_log_message_n string [...]
#	Just like rc_log_message, except without appending a newline.
#
rc_log_message_n()
{
	_rc_log_buffer="${_rc_log_buffer}${*}"
	rc_log_flush
}

#
# rc_log_flush [OK|FORCE]
#	save outstanding messages from $_rc_log_buffer to $RC_LOG_FILE.
#
# The log file is expected to reside in the /var/run directory, which
# may not be writable very early in the boot sequence, and which is
# erased a little later in the boot sequence.  We therefore avoid
# writing to the file until we believe it's safe to do so.  We also
# assume that it's reasonable to always append to the file, never
# truncating it.
#
# Optional argument $1 may be "OK" to report that writing to the log
# file is expected to be safe from now on, or "FORCE" to force writing
# to the log file even if it may be unsafe.
#
# Returns a non-zero status if messages could not be written to the
# file.
#
rc_log_flush()
{
	#
	# If $_rc_log_flush_ok is false, then it's probably too early to
	# write to the log file, so don't do it, unless $1 is "FORCE".
	#
	: ${_rc_log_flush_ok=false}
	case "$1:$_rc_log_flush_ok" in
	OK:*)
		_rc_log_flush_ok=true
		;;
	FORCE:*)
		: OK just this once
		;;
	*:true)
		: OK
		;;
	*)
		# it's too early in the boot sequence, so don't flush
		return 1
		;;
	esac

	#
	# Now append the buffer to the file.  The buffer should already
	# contain a trailing newline, so don't add an extra newline.
	#
	if [ -n "$_rc_log_buffer" ]; then
		if { printf "%s" "${_rc_log_buffer}" >>"${RC_LOG_FILE}" ; } \
			2>/dev/null
		then
			_rc_log_buffer=""
		else
			return 1
		fi
	fi
	return 0
}

#
# Most of the action is in the rc_real_work() and rc_postprocess()
# functions.
#
rc_real_work "$@" 2>&1 | rc_postprocess
exit $?