add system information gathering, in cfengine speek this will create our hard classes

+#!/bin/dash
+
+##
+# This is a first test what static informations I can gather from a
+# system. The minimal requirement are the IP addresses because
+# on these I build up my classes.
+# The system type is also important...we might need to be running
+# on variuous UNIX flavours. (But for now we focus on various linux
+# flavours and maybe FreeBSD.
+#
+
+
+# Function calculates number of bit in a netmask
+#
+mask2cidr() {
+	local NBITS=0
+	local OLDIFS="${IFS}"
+	IFS=.
+
+	for DEC in $1
+	do
+		case ${DEC} in
+			255) NBITS=$((NBITS+8));;
+			254) NBITS=$((NBITS+7));;
+			252) NBITS=$((NBITS+6));;
+			248) NBITS=$((NBITS+5));;
+			240) NBITS=$((NBITS+4));;
+			224) NBITS=$((NBITS+3));;
+			192) NBITS=$((NBITS+2));;
+			128) NBITS=$((NBITS+1));;
+			0);;
+			*) NBITS=0; IFS="${OLDIFS}"; return 1
+		esac
+	done
+	IFS="${OLDIFS}"
+	${ECHO} "${NBITS}"
+}
+
+cidr2mask() {
+	local MASK=""
+	local FULL_OCTETS=$((${1}/8))
+	local PARTIAL_OCTET=$((${1}%8))
+
+	for I in 0 1 2 3
+	do
+		if [ ${I} -lt ${FULL_OCTETS} ]
+		then
+			MASK="${MASK}255"
+		elif [ ${I} -eq ${FULL_OCTETS} ]
+		then
+			MASK="${MASK}$((256-(1<<(8-${PARTIAL_OCTET}))))"
+		else
+			MASK="${MASK}0"
+		fi  
+		${TEST} ${I} -lt 3 && MASK="${MASK}."
+	done
+
+	${ECHO} ${MASK}
+}
+
+##
+# retrieve interfaces. I prefer using ip if it is
+# available, else I fallback to ifconfig... don't know
+# how to retrieve this information on other systems.
+#
+get_if_data() {
+	if [ ${IP} ]
+	then
+		eval $(${IP} -o link | ${AWK} '{
+			sub(/:/,"",$1);
+			no=$1;
+			sub(/:/,"",$2);
+			name=$2;
+			for (i=3; i<NF; i++) {
+				if ($i == "state") {
+					i++; state=$i
+				}
+				if ($i ~ /link/) {
+					i++; mac=$i;
+					classes=classes mac " "
+				}
+			}
+			print "IF" no "_NAME=" name ";IF" no "_STATE=" state ";IF" no "_MAC=" mac ";";
+			if ("UP" == state) classes=classes mac " "
+		}
+		BEGIN {
+			classes=""
+		}
+		END {
+			print "CLASSES=\"${CLASSES}" classes " \";";
+			print "NINTERFACES=" FNR ";"
+		}')
+
+		eval $(${IP} -o addr | ${AWK} '{
+			sub(/:/,"",$1);
+			no=$1;
+			if ($3 == "inet") {
+				sub(/[\/%].*/,"",$4);
+				print "IF" no "_IPV4=\"${IF" no "_IPV4}" $4 " \";";
+				classes=classes $4 " "
+			}
+			if ($3 == "inet6") {
+				sub(/[\/%].*/,"",$4);
+				print "IF" no "_IPV6=\"${IF" no "_IPV6}" $4 " \";";
+				classes=classes $4 " "
+			}
+		}
+		BEGIN {
+			classes=""
+		}
+		END {
+			print "CLASSES=\"${CLASSES}" classes " \";"
+		}')
+	else
+		if [ ${IFCONFIG} ]
+		then
+			#eval $(${IFCONFIG} -a | ${AWK} '{
+			eval $(ifconfig -a | awk '
+			/ether/ { mac=$2 }
+			/inet / { ipv4=ipv4 $2 " " }
+			/inet6/ { ipv6=ipv6 $2 " " }
+			/^[^ \t]/ {
+				if ("" != ipv4 || "" != ipv6) state="UP"; else state="DOWN";
+				if ("" != name) {
+					print "IF" no "_NAME=" name ";IF" no "_STATE=" state ";IF" no "_MAC=" mac ";" \
+						"IF" no "_IPV4=\"${IF" no "_IPV4}" ipv4 " \";" \
+						"IF" no "_IPV6=\"${IF" no "_IPV6}" ipv6 " \";";
+					no++;
+				}
+				ipv4=ipv6="";
+				sub(/:/,"",$1);
+				name=$1
+			}
+			BEGIN {
+				no=1;
+			}
+			END {
+				if ("" != ipv4 || "" != ipv6) state="UP"; else state="DOWN";
+				print "IF" no "_NAME=" name ";IF" no "_STATE=" state ";IF" no "_MAC=" mac ";" \
+					"IF" no "_IPV4=\"${IF" no "_IPV4}" ipv4 " \";" \
+					"IF" no "_IPV6=\"${IF" no "_IPV6}" ipv6 " \";";
+				print "NINTERFACES=" no
+			}')
+		else
+			${LOGGER} -p local0.warn 'Found no way to retrieve interface information.'
+		fi
+	fi
+}
+
+##
+# start guessing the system type
+# 1. get informations via uname
+#
+get_host_info() {
+	OS="$(${UNAME} -o)"
+	KERNEL="$(${UNAME} -s)"
+	VERSION="$(${UNAME} -r)"
+	PLATFORM="$(${UNAME} -m)"
+	HOSTNAME="$(${UNAME} -n)"
+	CLASSES="$(${ECHO} -e "${OS}\n${KERNEL}\n${VERSION}\n${PLATFORM}\n${HOSTNAME}" |\
+		${SORT} -u | ${TR} "\n" " ")"
+}
+
+##
+# if we are on a linux try to figure out wich distribution we are
+# running.
+# First look what kind of realease file we have:
+#   
+#   00 01 - Novell SuSE   ---> /etc/SuSE-release
+#   00 02 - Red Hat       ---> /etc/redhat-release, /etc/redhat_version
+#   00 04 - Fedora        ---> /etc/fedora-release
+#   00 08 - Slackware     ---> /etc/slackware-release, /etc/slackware-version
+#   00 10 - Debian        ---> /etc/debian_release, /etc/debian_version
+#   00 20 - Mandrake      ---> /etc/mandrake-release
+#   00 40 - Yellow dog    ---> /etc/yellowdog-release
+#   00 80 - Sun JDS       ---> /etc/sun-release
+#   01 00 - Solaris/Sparc ---> /etc/release
+#   02 00 - Gentoo        ---> /etc/gentoo-release
+#
+# Here I follow a pessimistic way because I prefere to have no
+# identification at all over a wrong one...so I check for all these files.
+# If I can't find any or find multiple of them I assume this system
+# as unidentified. Anyway when I found one I still check the content...
+# Here I need some help as I don't know the valid content of these files.
+# For now I assume that at least the name of the distribution is in
+# the file.
+#
+get_dist_info() {
+	if [ -z "${KERNEL}" ]
+	then
+		get_host_info
+	fi
+
+	if [ "Linux" = "${KERNEL}" ]
+	then
+		local SUSE=1
+		local REDHAT=2
+		local FEDORA=4
+		local SLACKWARE=8
+		local DEBIAN=16
+		local MANDRAKE=32
+		local YELLOWDOG=64
+		local SUNJDS=128
+		local GENTOO=256
+		local SOLARIS=512
+
+		local LAST=${SOLARIS}
+
+		local CHK=$((SUSE|REDHAT|FEDORA|SLACKWARE|DEBIAN|MANDRAKE|\
+			YELLOWDOG|SUNJDS|GENTOO|SOLARIS))
+
+		eval local FILES_${SUSE}=\'/etc/SuSE-release\'
+		eval local FILES_${REDHAT}=\'/etc/redhat-release /etc/redhat_version\'
+		eval local FILES_${FEDORA}=\'/etc/fedora-release\'
+		eval local FILES_${SLACKWARE}=\'/etc/slackware-release /etc/slackware-version\'
+		eval local FILES_${DEBIAN}=\'/etc/debian_release /etc/debian_version\'
+		eval local FILES_${MANDRAKE}=\'/etc/mandrake-release\'
+		eval local FILES_${YELLOWDOG}=\'/etc/yellowdog-release\'
+		eval local FILES_${SUNJDS}=\'/etc/sun-release\'
+		eval local FILES_${GENTOO}=\'/etc/gentoo-release\'
+		eval local FILES_${SOLARIS}=\'/etc/release\'
+
+		local CUR=1
+		while [ ${CUR} -le ${LAST} ]
+		do
+			local DIR
+
+			eval local FILES=\"\${FILES_${CUR}}\"
+
+			for DIR in ${FILES}
+			do
+				${TEST} -f ${DIR} || CHK=$((CHK&~CUR))
+			done
+
+			CUR=$((CUR*2))
+		done
+
+		DIST="Unknown"
+
+		${TEST} ${CHK} -eq ${SUSE}      && DIST="Suse"
+		${TEST} ${CHK} -eq ${REDHAT}    && DIST="Redhat"
+		${TEST} ${CHK} -eq ${FEDORA}    && DIST="Fedora"
+		${TEST} ${CHK} -eq ${SLACKWARE} && DIST="Slakware"
+		${TEST} ${CHK} -eq ${DEBIAN}    && DIST="Debian"
+		${TEST} ${CHK} -eq ${MANDRAKE}  && DIST="Mandrake"
+		${TEST} ${CHK} -eq ${YELLOWDOG} && DIST="Yellowdog"
+		${TEST} ${CHK} -eq ${SUNJDS}    && DIST="Sun"
+		${TEST} ${CHK} -eq ${GENTOO}    && DIST="Gentoo"
+		${TEST} ${CHK} -eq ${SOLARIS}   && DIST="Solaris"
+
+		if [ 'Unknown' != "${DIST}" ]
+		then
+			eval ${GREP} -iq ${DIST} \${FILES_${CHK}} || DIST="Unknown"
+		fi
+
+		CLASSES="${CLASSES}${DIST} "
+	else
+		DIST="${OS}"
+	fi
+}
+
+##
+# Here now starts the usage of the functions defined above.
+#
+
+##
+# first specify some programs
+#
+WHICH="/usr/bin/which"
+UNAME="$(${WHICH} uname)"
+TEST="$(${WHICH} test)"
+GREP="$(${WHICH} grep)"
+AWK="$(${WHICH} awk)"
+ECHO="$(${WHICH} echo)"
+SORT="$(${WHICH} sort)"
+TR="$(${WHICH} tr)"
+PRINTF="$(${WHICH} printf)"
+LOGGER="$(${WHICH} logger)"
+IP="$(${WHICH} ip)"
+IFCONFIG="$(${WHICH} ifconfig)"
+
+get_dist_info
+get_if_data
+
+##
+# report everysthing
+#
+
+${PRINTF} "%15s : %s\n" "OS" "${OS}"
+${PRINTF} "%15s : %s\n" "KERNEL" "${KERNEL}"
+${PRINTF} "%15s : %s\n" "VERSION" "${VERSION}"
+${PRINTF} "%15s : %s\n" "PLATFORM" "${PLATFORM}"
+${PRINTF} "%15s : %s\n" "DIST" "${DIST}"
+${PRINTF} "%15s : %s\n" "HOSTNAME" "${HOSTNAME}"
+${PRINTF} "%15s : %s\n" "# INTERFACES" "${NINTERFACES}"
+
+NO=1
+while [ ${NO} -le ${NINTERFACES:=0} ]
+do
+	eval printf \"%15s : %s\\\n\" \"IF${NO}_NAME\" \"\${IF${NO}_NAME}\"
+	eval printf \"%15s : %s\\\n\" \"IF${NO}_MAC\" \"\${IF${NO}_MAC}\"
+	eval printf \"%15s : %s\\\n\" \"IF${NO}_STATE\" \"\${IF${NO}_STATE}\"
+	eval printf \"%15s : %s\\\n\" \"IF${NO}_IPV4\" \"\${IF${NO}_IPV4}\"
+	eval printf \"%15s : %s\\\n\" \"IF${NO}_IPV6\" \"\${IF${NO}_IPV6}\"
+	NO=$((NO+1))
+done
+
+${PRINTF} "%15s : %s\n" "CLASSES" "${CLASSES}"
+
+echo
+echo $(mask2cidr 255.255.128.0)
+echo $(cidr2mask 17)
+eval echo \$\(cidr2mask $(mask2cidr 255.255.128.0)\)
+
+# vim: set ts=4 sw=4: