[arch-projects] [RFC 10/23] Add function for parsing comma separated option list

[Matthew Monaco]

From: Matthew Monaco <matthew.monaco at 0x01b.net>

As far as the structure of the rest of the code goes, this one is a
little different because it sets the 'args' and 'swap' variables. I'd
like a cleaner way to do this.

With the exception of some special values, convert the comma separated
list of options to pass directly to cryptsetup. This means we don't have
to explicitly support all of cryptsetups options.

'size' and 'device-size' are needed because (yes) systemd and Debian use
size for cryptsetup's --key-size option. "cryptsetup --size create"
limits the size of a device.

'swap' means run mkswap after mounting, this is standard as far as the
Debian and systemd format goes.

'luks' and 'plain' are also used by Debian and systemd, but they seem
like superfluous configuration because "cryptsetup isLuks" gives this
information.

'noauto' will work with the default $FILTER (-O) of !noauto

'tmp' is supported by Debian and systemd. This will come in a later
commit.

There is also list of options which are supported by Debian that we'll
ignore.
---
 cryptmount.sh |   69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)

diff --git a/cryptmount.sh b/cryptmount.sh
index 55a6944..7e89bbc 100755
--- a/cryptmount.sh
+++ b/cryptmount.sh
@@ -149,6 +149,17 @@ ct_main() {
 		info "udevd not running, or unable to detect it: waiting for devices disabled"
 	fi
 
+	# Pre-parse OPTIONS, a little ugly, but it works
+	preparse() {
+		local args swap
+		if ! ct_parse_options $OPTIONS; then
+			error "Invalid options string: $OPTIONS"
+			exit 1
+		fi
+		OPTIONS="$args"
+	}
+	preparse
+
 	if [ -z "$action" -o "$action" = "list" ]; then
 
 		if [ $# -ne 0 ]; then
@@ -359,6 +370,64 @@ ct_resolve_device() {
 		return 1
 	fi
 }
+
+ct_parse_options() {
+
+	local IFS=',' optlst="$*" opt key val
+
+	for opt in $optlst; do
+
+		# separate key and value
+		unset key val
+		case "$opt" in
+			"")
+				continue;;
+			*=*)
+				key="${opt%%=*}"
+				val="${opt#*=}"
+				[ "$key" = "$val" ] && unset val
+				;;
+			*)
+				key="$opt";;
+		esac
+
+		case "$key" in
+			swap)
+				# set external variable
+				swap=1
+				;;
+			luks|plain)
+				warn "Ignoring option $key, LUKS volumes are automatically detected"
+				;;
+			noauto|%*)
+				:
+				;;
+			skip|precheck|check|checkargs|noearly|loud|keyscript)
+				warn "Ignoring Debian specific option '$key'"
+				;;
+			tmp)
+				warn "The tmp= option is not supported"
+				;;
+			size)
+				args="$args --key-size $val"
+				;;
+			device-size)
+				args="$args --size $val"
+				;;
+			*)
+				if [ ${#key} -eq 1 ]; then
+					args="$args -$key $val"
+				else
+					args="$args --$key $val"
+				fi
+				;;
+		esac
+
+	done
+
+	return 0
+}
+
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